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Evaluation of<br />

Opportunities for<br />

Converting Indigenous UK<br />

Wastes <strong>to</strong> Fuels and<br />

Energy<br />

Report <strong>to</strong> <strong>the</strong> National Non-Food Crops Centre<br />

This project was managed <strong>by</strong> <strong>the</strong> NNFCC and<br />

funded Report/proposal <strong>by</strong> DECC. <strong>to</strong> (name of company)<br />

Restricted Commercial<br />

Restricted Commercial<br />

ED Numbers<br />

ED45551<br />

Issue Number<br />

Issue Number 1<br />

Date 2007<br />

July 2009


2<br />

Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Fuels and Energy<br />

AEA/ED45551/Issue 1<br />

Title Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Fuels<br />

and Energy<br />

Cus<strong>to</strong>mer National Non-Food Crops Centre (NNFCC)<br />

Cus<strong>to</strong>mer reference 09/012<br />

Confidentiality,<br />

copyright and<br />

reproduction<br />

Copyright AEA Technology<br />

This proposal is submitted <strong>by</strong> AEA Technology in response <strong>to</strong> an invitation<br />

<strong>to</strong> tender from <strong>the</strong> NNFCC “Review of technologies for gasification of<br />

biomass and wastes in <strong>the</strong> UK”. It may not be used for any o<strong>the</strong>r purposes,<br />

reproduced in whole or in part, nor passed <strong>to</strong> any organisation or person<br />

without <strong>the</strong> specific permission in writing of <strong>the</strong> Commercial Manager, AEA<br />

Technology plc.<br />

File reference M:\Projects\Consultancy\NNFCC\Report<br />

Reference number ED45551<br />

AEA Energy & Environment<br />

The Gemini Building<br />

Fermi Avenue<br />

Harwell International Business Centre<br />

Didcot<br />

OX11 0QR<br />

t: 0870 190 6036<br />

f: 0870 190 6318<br />

AEA is a business name of AEA Technology plc<br />

AEA is certificated <strong>to</strong> ISO9001 and ISO14001<br />

Author Name Louise Evans, Shoko Okamura, Jim Poll, Nick Barker<br />

Approved <strong>by</strong> Name Pat Howes<br />

Signature<br />

Date 04.09.2009


Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Fuels and Energy<br />

AEA/ED45551/Issue 1<br />

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Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Fuels and Energy<br />

AEA/ED45551/Issue 1<br />

1 Executive Summary<br />

Main Conclusions<br />

The UK has a large resource of waste materials that could be used for renewable energy.<br />

Data on municipal solid waste composition and arisings is very good; however data for industrial and<br />

commercial arisings is poor.<br />

Processes that deliver heat, or combined heat and power with a high heat <strong>to</strong> power ratio, give excellent<br />

greenhouse gas abatement potential. To maximise <strong>the</strong> benefit installations need <strong>to</strong> be sized <strong>to</strong> match <strong>the</strong><br />

energy demand, ra<strong>the</strong>r than <strong>the</strong> <strong>to</strong>nnage of waste, resulting often in smaller installations in a multiplicity of<br />

locations. These will require <strong>the</strong> use of fuels with consistent properties such as graded wood chip, or<br />

solid recovered fuels. Processes for <strong>the</strong> production of <strong>the</strong>se fuels should be regarded as important<br />

enabling technologies. Their technical development should be supported as should <strong>the</strong>ir introduction in <strong>to</strong><br />

<strong>the</strong> market as a traded commodity such through <strong>the</strong> development of standards and codes.<br />

Anaerobic digestion for <strong>the</strong> treatment of food and o<strong>the</strong>r wet organic waste is technically viable and has<br />

substantial environmental benefits when <strong>the</strong> product gas is used <strong>to</strong> fuel combined heat and power<br />

installations or is cleaned for injection in<strong>to</strong> <strong>the</strong> natural gas distribution system. There is however a<br />

potential barrier <strong>to</strong> future progress due <strong>to</strong> <strong>the</strong> constraint on land availability for <strong>the</strong> disposal of <strong>the</strong><br />

digestate posed <strong>by</strong> its nitrogen content, in additional <strong>to</strong> its economic feasibility in a number if situations.<br />

Combustion remains <strong>the</strong> default technology for energy generation. Gasification processes are less<br />

developed but those that burn <strong>the</strong> product gas in a boiler seem <strong>to</strong> be a robust option with some<br />

advantages over conventional combustion.<br />

Considerable work is currently underway <strong>to</strong> develop and demonstrate <strong>the</strong> production of transport fuels<br />

from biomass and waste using gasification. It is likely <strong>to</strong> be several years before <strong>the</strong>se technologies<br />

make an impact on <strong>the</strong> UK market.<br />

The production of pipeline gas <strong>by</strong> gasification and methanation shows great potential but <strong>the</strong>re is little<br />

data on <strong>the</strong> benefits of <strong>the</strong> process in particular <strong>the</strong> use of <strong>the</strong> high grade heat available from <strong>the</strong><br />

methanation reac<strong>to</strong>r.<br />

The majority of <strong>the</strong>rmal gasification and pyrolysis processes require regularly sized, consistent feeds<strong>to</strong>cks<br />

underling <strong>the</strong> importance of <strong>the</strong> development of a market for traded waste fuels.<br />

NNFCC can make a very useful contribution <strong>by</strong> building on its strengths in information provision and<br />

communication with stakeholders.<br />

The NNFCC tasked AEA with delivering an Evaluation of Opportunities for Converting Indigenous UK<br />

Wastes <strong>to</strong> Fuels and Energy. Such a study requires an investigation of <strong>the</strong> UK waste arisings <strong>by</strong> type<br />

and <strong>by</strong> region, combined with an in depth consideration of <strong>the</strong> technologies available <strong>to</strong> convert such<br />

wastes and how <strong>the</strong>ir adoption might best be encouraged.<br />

This study is an important element in developing <strong>the</strong> NNFCC’s position with regard <strong>to</strong> waste utilisation<br />

options. The findings will enable <strong>the</strong> NNFCC <strong>to</strong> develop an appropriate and effective insight in<strong>to</strong> <strong>the</strong><br />

waste situation and market in <strong>the</strong> UK, and how it might be used as a resource <strong>to</strong> derive energy and fuels.


Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Fuels and Energy<br />

AEA/ED45551/Issue 1<br />

The NNFCC’s current focus is materials and energy from crops, and as a proportion of <strong>the</strong> UK’s waste<br />

arisings originate from agricultural activities, <strong>the</strong> opportunity <strong>the</strong>refore exists <strong>to</strong> develop a strong and<br />

coherent position on <strong>the</strong> utilisation of <strong>the</strong>se wastes <strong>to</strong> generate energy and fuels.<br />

To fulfil <strong>the</strong> objectives of <strong>the</strong> task set for this study we <strong>the</strong>refore need <strong>to</strong> understand a number of aspects<br />

of <strong>the</strong> current and future waste industry. The most important are<br />

• <strong>the</strong> character and extent of <strong>the</strong> waste resource,<br />

• <strong>the</strong> status of those energy technologies with improved resource efficiency, and,<br />

• <strong>the</strong> benefits that <strong>the</strong>ir adoption might bring.<br />

• Following <strong>the</strong> review of technologies we considered what role NNFCC might have in realising<br />

<strong>the</strong> benefits.<br />

1.1 The character and extent of <strong>the</strong> waste resource<br />

In this study <strong>the</strong> wastes that have been identified as having <strong>the</strong> potential for conversion <strong>to</strong> fuels and<br />

energy have been subdivided as follows:<br />

• Municipal solid wastes (MSW)<br />

• Commercial and industrial wastes (C&I)<br />

• Construction and Demolition (C&D)<br />

• Bio-Solids (Sewage Sludge)<br />

• Agricultural<br />

o Wet residues<br />

o Dry residues<br />

• Forestry Residues<br />

The <strong>to</strong>tal UK waste arisings of all types were estimated <strong>to</strong> be 335 million <strong>to</strong>nnes in 2004 and 307 million<br />

<strong>to</strong>nnes in 2005. This includes nearly 100 million <strong>to</strong>nnes of minerals waste from mining and quarrying, and<br />

220 million <strong>to</strong>nnes of controlled wastes from households, commerce and industry. Household wastes<br />

represent about 9 per cent of <strong>to</strong>tal arisings.<br />

His<strong>to</strong>rically, waste arisings have been shown <strong>to</strong> grow in line with, or even above, <strong>the</strong> level of economic<br />

growth. However, <strong>the</strong> continuation of this trend is now considered <strong>to</strong> be unsustainable, and thus <strong>the</strong> sixth<br />

Environment Action Programme 1 set an objective <strong>to</strong> achieve a decoupling of resource use from economic<br />

growth through significantly improved resource efficiency, dematerialisation of <strong>the</strong> economy and waste<br />

prevention.<br />

The premise of this study is that much of <strong>the</strong> waste that is currently disposed of through conventional<br />

incineration or <strong>to</strong> landfill could be used more efficiently as a feeds<strong>to</strong>ck for more efficient generation of<br />

heat and power, pipeline gas, or <strong>the</strong> production of transport fuels.<br />

To investigate this we first consider each waste resource from <strong>the</strong> viewpoint of its origin <strong>the</strong>n from <strong>the</strong><br />

perspective of its content of material that could be used for fuels.<br />

Municipal Solid Waste comprises a very large range of materials, and <strong>to</strong>tal waste arisings are<br />

increasing. Recycling initiatives decrease <strong>the</strong> proportion of waste going straight for disposal, and <strong>the</strong><br />

level of recycling is increasing each year. Most growth forecasts use a growth rate of 0.75% per annum.<br />

Commercial and Industrial waste is also comprised of a very large range of materials. Overall levels of<br />

industrial waste are decreasing, while levels of commercial wastes are increasing. Again, recycling<br />

initiatives decrease <strong>the</strong> proportion of waste going straight for disposal, and <strong>the</strong> level of recycling is<br />

increasing each year. Growth rates have been taken as 1% per annum for commercial waste, and 0%<br />

per annum for industrial waste.<br />

1 The Sixth Environment Action Programme of <strong>the</strong> European Community 2002-2012, http://ec.europa.eu/environment/newprg/index.htm<br />

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Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Fuels and Energy<br />

AEA/ED45551/Issue 1<br />

Construction and Demolition waste is largely comprised of mineral waste, with small amounts of wood,<br />

plastics and metals. Most investigation of this waste stream has focused on recycling <strong>the</strong> mineral<br />

proportion in<strong>to</strong> aggregate. Of <strong>the</strong> three controlled waste streams this one produces <strong>the</strong> greatest <strong>to</strong>nnage<br />

of waste, but has little or no fuel content.<br />

Bio-solids are produced from waste water treatment sites, as <strong>the</strong> main <strong>by</strong>-product. Data quality is<br />

generally good and in 2004/5 1.72 Mt of dry bio-solids was produced. Estimates are that this will increase<br />

<strong>to</strong> 2.5 Mt <strong>by</strong> 2030 due <strong>to</strong> an increasing number of households and tighter waste water and pollutions<br />

controls through legislation.<br />

Agricultural residues include manures and slurries, and straw and poultry litter. Levels of available<br />

straw (after traditional uses) for 2006 were estimated <strong>to</strong> be 2.9 million <strong>to</strong>nnes for <strong>the</strong> UK, while poultry<br />

litter with an energy content of 37 million GJ was produced. Manures and slurries from cattle were<br />

estimated <strong>to</strong> produce a <strong>to</strong>tal, collectable, 9.9 million kilograms per day of volatile solids, pigs 669<br />

thousand kilograms per day of volatile solids and fowls 1.8 million kilograms per day of volatile solids.<br />

Accurate current and future arisings are difficult <strong>to</strong> predict as <strong>the</strong> sec<strong>to</strong>r is highly dependent on wea<strong>the</strong>r,<br />

farming practices and markets. Residues are usually recycled <strong>to</strong> land apart from poultry litter, that is<br />

al<strong>read</strong>y approximately 50 percent is committed <strong>to</strong> energy from waste plants, and a small proportion of<br />

cereal<br />

Forestry residues arise from forests and woodlands, primary processing co-products and arboricultural<br />

work. Total available forestry residues in <strong>the</strong> UK are estimated <strong>to</strong> be 1,987,000 odt per annum, although<br />

it is unlikely this <strong>full</strong> amount could be realised for energy, and <strong>the</strong> data quality is generally uncertain.<br />

Some future estimations show an increase of material available, but no significant changes are expected.<br />

Not all waste is suitable as a renewable fuel and some waste streams contain only a proportion of<br />

material that could be used as fuel. Figure 1 illustrates <strong>the</strong> <strong>to</strong>tal quantities of waste from each of <strong>the</strong><br />

streams above and <strong>the</strong> <strong>to</strong>tal content of materials that could be used for energy.


Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Fuels and Energy<br />

AEA/ED45551/Issue 1<br />

Total MSW<br />

34,400,000 <strong>to</strong>nnes pa<br />

Total C&I<br />

82,600,000 <strong>to</strong>nnes pa<br />

Total C&D<br />

118,600,000 <strong>to</strong>nnes pa<br />

Bio-solids<br />

1,720,000 <strong>to</strong>nnes pa<br />

Figure 1 Total Waste Arisings for <strong>the</strong> UK<br />

Estimated Food<br />

12,325,000 <strong>to</strong>nnes pa<br />

Estimated Paper and<br />

board<br />

26,309,000 <strong>to</strong>nnes pa<br />

Estimated Wood from<br />

all waste sources<br />

10,541,000 <strong>to</strong>nnes pa<br />

Agricultural Residues<br />

Total Manure 12,400,000t pa<br />

Straw 2,912,000t pa after<br />

traditional uses have been taken in<strong>to</strong><br />

account<br />

Forestry Residues<br />

1,987,000 odt pa<br />

After traditional uses have been taken in<strong>to</strong><br />

account<br />

As is apparent from <strong>the</strong>se figures <strong>the</strong>re is a very substantial amount of potential fuel available in <strong>the</strong><br />

waste arisings from <strong>the</strong> UK. Clearly not all of <strong>the</strong>se are immediately available for energy production and<br />

many fac<strong>to</strong>rs can influence <strong>the</strong> amount of renewable energy that waste can contribute:<br />

• recycling is increasing rapidly and will reduce <strong>the</strong> availability of wood and paper;<br />

• pressure <strong>to</strong> reduce landfill <strong>to</strong> meet EU directives may result in take up of <strong>the</strong> more proven options<br />

of mass burn combustion with energy recovery, and composting, ra<strong>the</strong>r than more innovative<br />

approaches that could offer a higher energy return but require time <strong>to</strong> become established;<br />

• <strong>the</strong> Renewables Obligation could drive cleaner waste resources <strong>to</strong>ward electricity generation<br />

ra<strong>the</strong>r combined heat and power and o<strong>the</strong>r more resource efficient applications.<br />

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Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Fuels and Energy<br />

AEA/ED45551/Issue 1<br />

These fac<strong>to</strong>rs and how waste is collected and used generally are controlled <strong>to</strong> an overwhelming degree<br />

<strong>by</strong> legislation and incentives. The European Commission determine <strong>the</strong> broad direction of policy and<br />

fur<strong>the</strong>r directives and UK legislation determine <strong>the</strong> detail of its execution.<br />

The main measures that will shape <strong>the</strong> industry and encourage <strong>the</strong> generation of energy are:<br />

The Renewables Obligation – rewards electricity generation from electricity for clean biomass wastes<br />

and CHP from all biomass wastes.<br />

Renewable Transport Fuels Obligation – will create a market for renewable transport fuels.<br />

Future heat incentives – will reward <strong>the</strong> production of heat and CHP from renewable waste.<br />

The Landfill Directive – sets legally binding targets for diversion from landfill of organic material from<br />

MSW, national legislation imposes financial penalties for non compliance.<br />

Waste Framework Directive – revised and updated it places an emphasis on carbon-efficient resource<br />

recovery and requires <strong>the</strong> bio-waste fraction of MSW <strong>to</strong> be collected separately <strong>to</strong> enable composting and<br />

digestion.<br />

The long term impact of <strong>the</strong>se measures on <strong>the</strong> flow of waste materials and <strong>the</strong> proportion diverted <strong>to</strong><br />

energy is not clear at present.<br />

1.2 The status of those energy technologies with<br />

improved resource efficiency<br />

An energy system based on <strong>the</strong> use of wastes and biomass is built up as a chain of several operations.<br />

Waste is collected, processed and delivered <strong>to</strong> a generating plant where it can be converted <strong>to</strong> heat,<br />

power or transport fuels. Each step is delivered <strong>by</strong> a different sec<strong>to</strong>r with its own priorities and<br />

constraints.<br />

The technologies that have been explored within this study are:<br />

• Processes for <strong>the</strong> manufacture of solid recovered fuels and o<strong>the</strong>r manufactured fuels.<br />

o Mechanical Biological Treatment<br />

o Mechanical Heat Treatment<br />

o Wood chips and pellet fuels<br />

• Technologies for <strong>the</strong> conversion of waste <strong>to</strong> energy products.<br />

o Combustion technologies<br />

o Anaerobic Digestion<br />

o Hydrolysis<br />

o Gasification<br />

o Pyrolysis<br />

Examining <strong>the</strong> processes that would offer a high energy return from <strong>the</strong> waste fuel we found that this<br />

could be achieved ei<strong>the</strong>r from application in heat and CHP, or <strong>the</strong> use in advanced processes such as<br />

gasification and pyrolysis. Both cases require fuels that have improved properties and consistency<br />

compared with <strong>the</strong> raw state. Consequently we investigated processes for <strong>the</strong> manufacture of fuel<br />

products from waste streams as a key enabling technology. Manufactured fuels can offer <strong>the</strong> following<br />

benefits<br />

• Consistent properties that can be defined and used in contracts making <strong>the</strong> material a tradable<br />

commodity.<br />

• Physical and biological stability that makes longer term s<strong>to</strong>rage possible and can even out<br />

unbalances between <strong>the</strong> constant supply of waste and <strong>the</strong> seasonal demand for energy.<br />

• An opportunity <strong>to</strong> manage <strong>the</strong> properties of <strong>the</strong> fuel <strong>to</strong> achieve optimum performance from <strong>the</strong><br />

energy technology.


Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Fuels and Energy<br />

AEA/ED45551/Issue 1<br />

We have identified <strong>the</strong> following manufactured fuels on sale or planned in <strong>the</strong> UK.<br />

• Solid recovered fuels. These fuels are produced from mixed wastes from <strong>the</strong> municipal and<br />

commercial stream <strong>by</strong> separating <strong>the</strong> high heating value components.<br />

• Graded waste wood fuels. Waste wood is collected from industry and amenity centres and<br />

graded depending on <strong>the</strong> level of contamination. The grades are <strong>the</strong>n chipped and sold <strong>to</strong> a<br />

specification.<br />

• Clean grade wood chips from virgin materials. Wood residues for forestry and sawmills are<br />

chipped and potentially dried <strong>to</strong> meet a specification.<br />

• Domestic grade wood pellet fuel from saw mill <strong>by</strong>-product. Sawmill residues, in particular<br />

sawdust, is dried and compressed through a die in<strong>to</strong> small cylinders. This fuel is clean, free<br />

flowing and suitable for small scale combustion appliances.<br />

• Industrial grade pellet from forestry, cereal processing residue and clean waste wood.<br />

This is similar <strong>to</strong> <strong>the</strong> domestic pellet but has a higher ash content and larger size.<br />

• Thermochemical fuels. These are chars and pyrolysis oils produced close <strong>to</strong> <strong>the</strong> point of<br />

arising. We also include <strong>to</strong>rrefaction, or high temperature drying in this category.<br />

Following a review of <strong>the</strong> area our conclusions were as follows;<br />

• Processes are commercially available for producing fuels from MSW and C&I waste using <strong>the</strong><br />

heat from composting as <strong>the</strong> energy for drying.<br />

• Processes for <strong>the</strong> production of fuels using <strong>the</strong>rmal energy <strong>to</strong> dry and sterilise waste are currently<br />

being demonstrated and may offer advantages in providing a more consistent product that is<br />

biologically stable for longer periods.<br />

• Standards for fuels derived from MSW are being developed but are not as yet widely used.<br />

• The production of graded wood waste fuels has expanded rapidly in <strong>the</strong> last three years.<br />

Standards and codes are being adopted <strong>by</strong> <strong>the</strong> industry which is aiding acceptance and<br />

development.<br />

• Clean wood fuels are becoming widesp<strong>read</strong> and standards and codes are being adopted <strong>by</strong> <strong>the</strong><br />

industry.<br />

• Fuels prepared using pyrolysis and <strong>to</strong>rrefaction have been proposed but as yet are not<br />

implemented commercially.<br />

• There is no technical constraint for <strong>the</strong> development of this sec<strong>to</strong>r although <strong>the</strong>re are some non<br />

technical barriers remaining concerned with <strong>the</strong> adaptation of codes and standards.<br />

The wide variation in <strong>the</strong> physical and chemical properties of <strong>the</strong> various waste streams has led <strong>to</strong> many<br />

processes being developed and proposed. For example, <strong>the</strong> only energy recovery solution for <strong>the</strong><br />

majority of wet wastes is anaerobic digestion - for dry wastes <strong>the</strong>rmal processes such as combustion are<br />

more suitable. Given <strong>the</strong> wide differences in <strong>the</strong> technologies we chose <strong>to</strong> treat <strong>the</strong> conversion<br />

technologies in three categories; combustion, <strong>the</strong>rmochemical processes, and biological processes.<br />

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Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Fuels and Energy<br />

AEA/ED45551/Issue 1<br />

Combustion, or incineration is <strong>by</strong> far <strong>the</strong> most common method of extracting energy from solid waste in<br />

most European countries, in ei<strong>the</strong>r untreated form or as a prepared fuel.<br />

Our conclusions following a review of <strong>the</strong> area are as follows;<br />

• Combustion is a well established technology and <strong>the</strong> main technical challenges have been<br />

addressed. Whatever <strong>the</strong> difficulties with <strong>the</strong> properties of <strong>the</strong> fuel engineers have developed<br />

robust solutions that have been proven <strong>to</strong> work commercially at most scales. As a result of this,<br />

combustion remains <strong>the</strong> default technology for heat and power against which all new, more<br />

innovative, options must be measured.<br />

• There seems <strong>to</strong> be a combustion solution for all waste fuels.<br />

• There remains however significant technical uncertainty surrounding <strong>the</strong> impact of <strong>the</strong><br />

composition of <strong>the</strong> waste on <strong>the</strong> performance of <strong>the</strong> heat exchange surfaces, particularly fouling<br />

and corrosion.<br />

• O<strong>the</strong>r barriers remain, such as <strong>the</strong> largely negative public perception of such sites in some<br />

countries, notably <strong>the</strong> UK.<br />

• There are countless examples of combustion practice worldwide on which <strong>to</strong> draw.<br />

The technologies available for conversion of waste <strong>to</strong> heat and power are more widesp<strong>read</strong> than those for<br />

conversion <strong>to</strong> transport fuels, although work is ongoing on advanced conversion for liquid biofuels.<br />

Combustion gasification and pyrolysis all use heat <strong>to</strong> break down <strong>the</strong> structure of <strong>the</strong> feeds<strong>to</strong>ck so that<br />

<strong>the</strong> chemical energy can be released ei<strong>the</strong>r as heat or a fuel product. The conditions in <strong>the</strong> reac<strong>to</strong>r<br />

determine <strong>the</strong> products.<br />

When combustible waste enters a high temperature environment it will first dry and <strong>the</strong>n decompose in<strong>to</strong><br />

volatile gas and char components.<br />

Gasification processes use a limited supply of oxidant; usually air, <strong>to</strong> maintain both combustion<br />

and reducing reactions in <strong>the</strong> same reac<strong>to</strong>r. Most of <strong>the</strong> energy in <strong>the</strong> fuel is transferred in<strong>to</strong> <strong>the</strong><br />

calorific value (CV) of <strong>the</strong> gas leaving <strong>the</strong> reac<strong>to</strong>r. This gas can be burned separately in a boiler,<br />

engine or gas turbine. Alternatively it can be converted <strong>by</strong> a syn<strong>the</strong>sis reaction <strong>to</strong> methane for<br />

injection <strong>to</strong> <strong>the</strong> Natural Gas Grid or liquid fuels for transport.<br />

In a pyrolysis process <strong>the</strong>re is no oxygen and <strong>the</strong> char and volatile gas remain largely<br />

unchanged. The energy in <strong>the</strong> waste is retained in <strong>the</strong> CV of <strong>the</strong> gas and char removed from <strong>the</strong><br />

reac<strong>to</strong>r.<br />

There are a number of perceived advantages that are often quoted <strong>by</strong> gasification and pyrolysis suppliers<br />

as solutions for perceived weaknesses in <strong>the</strong> current market leader – incineration. These claims with our<br />

comment are shown in <strong>the</strong> Table 1 below.<br />

Table 1 Claims for gasification/pyrolysis with comments<br />

Incineration Gasification/pyrolysis Comment<br />

Large (Regional) size and fuel<br />

demand suppresses recycling.<br />

Small volume of hazardous<br />

and <strong>to</strong>xic fly ash.<br />

Bulky residual ash can be<br />

used as a aggregate.<br />

Can be built economically at <strong>the</strong><br />

smaller sizes that can be<br />

integrated in<strong>to</strong> local schemes.<br />

This remains <strong>to</strong> be<br />

demonstrated, but is probably<br />

true.<br />

No dioxin found in fly ash. This seems <strong>to</strong> be valid.<br />

Some options give low volume<br />

compact ash.<br />

Valid. Some incinera<strong>to</strong>rs can give<br />

low volume slag like ash but at a<br />

very high energy cost for ash<br />

melting.


Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Fuels and Energy<br />

AEA/ED45551/Issue 1<br />

Incineration Gasification/pyrolysis Comment<br />

Poor electrical efficiency and<br />

lack of suitable heat loads<br />

gives poor resource use<br />

efficiency.<br />

Some options can give very high<br />

electrical efficiencies. Smaller<br />

sizes can match heat loads<br />

better. Particularly as <strong>the</strong>se are<br />

often independent of <strong>the</strong> power<br />

supply.<br />

Electricity and or heat only. Some options can be used <strong>to</strong><br />

generate gas or transport fuels.<br />

Very few demonstrations of high<br />

electrical efficiency. Lack of<br />

enthusiasm for CHP.<br />

Installations in wood waste<br />

sec<strong>to</strong>r now making progress.<br />

True at very large scale.<br />

Following our review our conclusions were as follows;<br />

• Gasification technologies are being developed but often encounter severe technical difficulties<br />

when attempting <strong>the</strong> step of using <strong>the</strong> gas for power generation in an engine or gas turbine.<br />

• The robust approach of firing <strong>the</strong> gas in a boiler is proving reliable and a worthwhile innovation.<br />

These units can be produced in smaller sizes than conventional incineration and can be matched<br />

<strong>to</strong> heat loads in CHP and process heating applications <strong>to</strong> give potentially <strong>the</strong> best GHG<br />

abatement potential.<br />

• Gasification as a pre-treatment is likely <strong>to</strong> become more popular in cofiring as genera<strong>to</strong>rs seek <strong>to</strong><br />

increase <strong>the</strong> proportion of biomass in coal fired utility boilers.<br />

• There are few commercial pyrolysis plant operating on waste.<br />

• The use of gasification at very large scale for <strong>the</strong> production of transport fuels or pipeline<br />

methane is attracting increasing attention and is potentially an efficient use of resources.<br />

Biological processes for waste include anaerobic digestion for <strong>the</strong> production of methane fuel gas and<br />

<strong>the</strong> hydrolysis and subsequent fermentation <strong>to</strong> ethanol fuels of <strong>the</strong> hemi-cellulose and cellulose fractions<br />

of lignocellulosic materials.<br />

Following our review of <strong>the</strong>se technologies our conclusions were as follows;<br />

• Anaerobic digestion processes are technically viable and available for most wet waste feeds<strong>to</strong>cks<br />

including sewage bio-solids.<br />

• Using a proportion of food waste is important <strong>to</strong> <strong>the</strong> economics of anaerobic digestion due <strong>to</strong> its<br />

high gas generation potential and gate fee. Manures are bulky and have poor gas potential.<br />

• Digestate disposal is becoming difficult due <strong>to</strong> constraints in nitrogen sensitive areas.<br />

• Composting is a lower cost alternative <strong>to</strong> AD but does not produce energy and can be regarded<br />

as a competi<strong>to</strong>r <strong>to</strong> AD. It is popular with waste managers due <strong>to</strong> <strong>the</strong> cost and its status as a<br />

recovery, ra<strong>the</strong>r than a disposal process. Disposal of compost <strong>to</strong> land suffers from <strong>the</strong> same<br />

constraints as AD digestates.<br />

• Hydrolysis and subsequent fermentation <strong>to</strong> alcohol fuels of <strong>the</strong> hemicellulose and cellulose<br />

fractions of lignocellulosic materals is still at <strong>the</strong> research stage although <strong>the</strong>re are plans for<br />

demonstration plants in <strong>the</strong> EU and USA. These are likely <strong>to</strong> be co-located with conventional<br />

grain ethanol facilities.<br />

• Feeds<strong>to</strong>cks are limited at present <strong>to</strong> clean wood and agricultural residues.<br />

• We question whe<strong>the</strong>r it should be a priority for <strong>the</strong> UK at present where clean residues are<br />

relatively expensive and could potentially be used in more efficient ways.<br />

1.3 Risks and barriers <strong>to</strong> deployment<br />

The risks and barriers that are faced when adopting novel technologies can be considerable. In <strong>the</strong> table<br />

below we first identify <strong>the</strong> main risks in deploying <strong>the</strong> technologies described above we <strong>the</strong>n describe in<br />

more detail those that we have classed as high or medium.<br />

11


Table 2 Summary of Technologies and <strong>the</strong> Risks and Barriers <strong>to</strong>wards adoption.<br />

12<br />

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Colour of red, yellow or green signifies <strong>the</strong> risk status of <strong>the</strong> technology: red is high risk, yellow is medium risk and green is low risk.<br />

Risks<br />

Technology Technical Social and Planning Financial Regula<strong>to</strong>ry<br />

Mechanical and<br />

Biological<br />

Treatment (MBT)<br />

Mechanical and<br />

Heat Treatment<br />

(MHT)<br />

Low Medium<br />

Not as divisive as an<br />

incinera<strong>to</strong>r but still subject of<br />

concern as a waste<br />

technology.<br />

High<br />

Demonstration projects only at present.<br />

Combustion Low <strong>to</strong> medium<br />

Many commercial installations,<br />

however <strong>the</strong> materials handling aspects<br />

have proved troublesome in <strong>the</strong> UK and<br />

<strong>the</strong>re is a lack of experience.<br />

Agricultural residues and poor quality<br />

wood fuels may give high ash contents<br />

that lead <strong>to</strong> problems with boiler fouling.<br />

Wastes regulated under WID will need<br />

extensive emissions moni<strong>to</strong>ring<br />

equipment.<br />

Medium<br />

Not as divisive as an<br />

incinera<strong>to</strong>r but still subject of<br />

concern as a waste<br />

technology.<br />

High<br />

High where used <strong>to</strong> produce<br />

electricity on a regional basis<br />

as it will be perceived as an<br />

incinera<strong>to</strong>r irrespective of its<br />

efficiency or recycling<br />

credentials<br />

Medium<br />

Requires revenue from sale of<br />

fuel but market not well<br />

established.<br />

Fuel is still classed as a waste<br />

which may give problems with<br />

sale and use, and hence<br />

price.<br />

Standards and agreed<br />

specifications are needed <strong>to</strong><br />

make <strong>the</strong> fuel product a<br />

traded commodity.<br />

Medium<br />

Requires revenue from sale of<br />

fuel but market not well<br />

established.<br />

Fuel is still classed as a waste<br />

which may give problems with<br />

sale and use, and hence<br />

price.<br />

Standards and agreed<br />

specifications are needed <strong>to</strong><br />

make <strong>the</strong> fuel product a<br />

traded commodity.<br />

Medium<br />

Track record of delays in<br />

planning for waste projects<br />

are a disincentive.<br />

Wood and agricultural<br />

residues are normally OK in<br />

normal circumstances<br />

Medium<br />

Fuel is still classed as a waste<br />

which may give problems with<br />

sale and use, and hence price.<br />

The legal status needs <strong>to</strong> be<br />

clarified. Standards would help<br />

<strong>to</strong> clarify definitions.<br />

Medium<br />

Fuel is still classed as a waste<br />

which may give problems with<br />

sale and use hence a reduced<br />

price.<br />

The legal status needs <strong>to</strong> be<br />

clarified. Standards would help<br />

<strong>to</strong> clarify definitions.<br />

Medium<br />

Receives subsidy via <strong>the</strong><br />

Renewables Obligation.<br />

Waste incineration directive<br />

compliance is usually<br />

necessary.<br />

Co-firing waste in a utility boiler<br />

is difficult as it would require <strong>the</strong><br />

reclassification of <strong>the</strong> whole<br />

station as an incinera<strong>to</strong>r<br />

Fly ash may contain dioxin and<br />

be classed as hazardous waste.


Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Fuels and Energy<br />

AEA/ED45551/Issue 1<br />

Technology Technical<br />

Risks<br />

Social and Planning Financial Regula<strong>to</strong>ry<br />

Anaerobic Digestion Low<br />

Medium<br />

Low<br />

Medium<br />

Established mature technology with Not as divisive as an<br />

Receives subsidy via <strong>the</strong><br />

operating commercial plant in incinera<strong>to</strong>r but transport of<br />

Renewables Obligation at an<br />

existence.<br />

slurries in rural areas is a<br />

enhanced rate of 2 ROCs under<br />

Limited experience in UK. Recent major issue and focus for<br />

<strong>the</strong> banding arrangements.<br />

incentives may stretch UK suppliers. opposition, as may be large<br />

Policy may change under<br />

Poor reputation from Holsworthy scale transport of food wastes.<br />

installations lifetime although<br />

experience.<br />

current practice is <strong>to</strong> maintain<br />

Sensitive <strong>to</strong> feeds<strong>to</strong>ck composition,<br />

<strong>the</strong> financial position of existing<br />

can be poisoned <strong>by</strong> trace elements.<br />

plant.<br />

The installation is classed as a<br />

waste management operation<br />

and subject <strong>to</strong> regulation as<br />

such which brings additional<br />

costs and responsibility.<br />

Digestate disposal is an<br />

important consideration and a<br />

change of rules could materially<br />

affect <strong>the</strong> operating costs of <strong>the</strong><br />

installation or even prevent<br />

operation.<br />

Hydrolysis High<br />

Medium<br />

High<br />

Medium<br />

The technology remains innovative Process should be no more The combination of<br />

Would require additional<br />

with only small demonstration and difficult <strong>to</strong> implement than a expensive processing and <strong>the</strong> subsidy from Renewable<br />

pilot projects built so far.<br />

biomass power plant. need for good quality transport fuels obligation.<br />

Feeds<strong>to</strong>cks are currently limited <strong>to</strong><br />

feeds<strong>to</strong>ck means that product<br />

clean wood and agricultural<br />

will be more expensive than<br />

residues. Contamination from o<strong>the</strong>r<br />

imported ethanol for some<br />

sources could damage fermentation<br />

time. This may make it<br />

process.<br />

unsuitable for use in <strong>the</strong> UK.<br />

Gasification High<br />

Medium<br />

High<br />

Medium<br />

Local<br />

Very few operating commercial plant Likely <strong>to</strong> be located on an Poor track record of<br />

for power or CHP.<br />

Significant residual risk in gas<br />

cleaning for power production.<br />

industrial site where impacts<br />

can be minimised.<br />

gasification technologies.<br />

Receives subsidy via <strong>the</strong><br />

Renewables Obligation.<br />

13<br />

Status of ash product is unclear<br />

under Waste Incineration<br />

Directive due <strong>to</strong> high carbon<br />

content.


14<br />

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Technology Technical<br />

Risks<br />

Social and Planning Financial Regula<strong>to</strong>ry<br />

Gasification High<br />

High<br />

High<br />

Medium<br />

Regional Very few operating commercial plant Where process is used Poor track record of<br />

Receives subsidy via <strong>the</strong><br />

for power or CHP.<br />

<strong>to</strong> produce electricity gasification technologies. Renewables Obligation. Status of<br />

Significant residual risk in gas on a regional basis as it<br />

ash product is unclear under Waste<br />

cleaning for power production. will be perceived as an<br />

Incineration Directive due <strong>to</strong> high<br />

Substantially lower risk for gas untried form of<br />

carbon content.<br />

combustion in boilers and process<br />

units.<br />

incinera<strong>to</strong>r.<br />

Gasification Medium<br />

Low<br />

Medium<br />

Medium<br />

National Little experience of biomass For syn gas production Poor track record of<br />

Receives subsidy via <strong>the</strong><br />

gasification for this application but at large scale on a gasification technologies but Renewable transport fuels<br />

substantial coal experience. petrochemical complex. developers are likely <strong>to</strong> be obligation. Risk for change in long<br />

Closely allied <strong>to</strong> refinery practice.<br />

substantial and have track<br />

record of delivery.<br />

lead time for build.<br />

Pyrolysis all scales High<br />

High<br />

High<br />

Medium<br />

Operating commercial plant in Where process is used Few suppliers and uneven Receives subsidy via <strong>the</strong><br />

existence for oil production little <strong>to</strong> produce electricity at track record.<br />

Renewables Obligation.<br />

experience in energy generation. a regional scale where<br />

it may be perceived as<br />

an untried and unsafe<br />

incinera<strong>to</strong>r.<br />

Low for syn gas<br />

production or <strong>the</strong>rmo<br />

chemical fuel<br />

production where it will<br />

be perceived as<br />

ano<strong>the</strong>r industrial<br />

process.


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AEA/ED45551/Issue 1<br />

1.4 Green house gas balances<br />

Life cycle analyses of waste <strong>to</strong> energy chains are complex and contain a range of fac<strong>to</strong>rs that are not<br />

always obvious or apparent. As part of this work we carried out analyses for a selection of routes for food<br />

waste and wood waste using <strong>the</strong> Defra / Environment Agency BEAT <strong>to</strong>ol. We also reviewed o<strong>the</strong>r work<br />

<strong>by</strong> <strong>the</strong> Environment Agency. Our conclusions are as follows:<br />

• Heat applications are <strong>the</strong> most beneficial in terms of GHG abatement followed <strong>by</strong> CHP where <strong>the</strong><br />

heat load is high.<br />

• Transport fuel production <strong>by</strong> means of gasification is predicted <strong>to</strong> be mid range. Methanation<br />

should be very beneficial if <strong>the</strong> high grade heat from <strong>the</strong> exo<strong>the</strong>rmal reaction is <strong>full</strong>y used,<br />

however we have no data on <strong>the</strong>se systems at present.<br />

• Electricity production comes lower in <strong>the</strong> hierarchy as do biological transport fuel processes and<br />

low heat load CHP.<br />

• Those applications that have <strong>the</strong> highest GHG benefit, such as industrial boilers and smaller<br />

CHP, are those that tend <strong>to</strong> use fuels that have consistent properties that can be s<strong>to</strong>red <strong>to</strong> match<br />

fuel supply with energy demand. These findings reinforce our conclusion that solid recovered<br />

fuels and o<strong>the</strong>r manufactured fuels are essential <strong>to</strong> <strong>the</strong> recovery of energy from waste at high<br />

levels of efficiency.<br />

• AD schemes score well due <strong>to</strong> <strong>the</strong> avoidance of methane emissions from landfill however this is<br />

mitigated <strong>to</strong> some extent <strong>by</strong> nitrous oxide emissions from land sp<strong>read</strong>ing of digestate.<br />

1.5 Challenges, issues and <strong>the</strong> role of NNFCC<br />

Throughout this <strong>report</strong> we have identified areas of uncertainty, and specific challenges that need work if<br />

<strong>the</strong> <strong>full</strong> potential of energy from waste is <strong>to</strong> be realised. These are set out in <strong>the</strong> table below. Most of<br />

<strong>the</strong>se are concerned with building business confidence in <strong>the</strong> links between each of <strong>the</strong> technology steps.<br />

Not all of this work will come under NNFCC’s remit but a significant amount is concerned with<br />

coordination of stakeholders and <strong>the</strong> provision of information <strong>to</strong> <strong>the</strong> market.<br />

Those <strong>to</strong>pics we feel are most appropriate for NNFCC initiatives are as follows:<br />

• Improve quality of policy and investment decision making <strong>by</strong> developing an understanding of <strong>the</strong><br />

fit between SRF properties and energy production technologies. What properties does each of<br />

<strong>the</strong> technologies require?<br />

• There is a wide difference in <strong>the</strong> benefits brought <strong>by</strong> various waste <strong>to</strong> energy chains and it is<br />

important that policy support those that contribute <strong>the</strong> most. NNFCC could add value <strong>to</strong> current<br />

and future work <strong>by</strong> developing an evidence base for <strong>the</strong> design and implementation of policy and<br />

a hierarchy of uses for each class of resource based on environmental and social benefits<br />

including life cycle GHG impact.<br />

• To maximise <strong>the</strong> benefits of using waste for energy we will need <strong>to</strong> change current practices<br />

across a wide range of stakeholders. NNFCC could add value <strong>by</strong> developing an understanding of<br />

15


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<strong>the</strong> relative timeframes of structural changes and technology developments necessary <strong>to</strong><br />

maximise implementation.<br />

• Develop a better market understanding of <strong>the</strong> impacts of increased energy usage on alternative<br />

and existing markets for straw and o<strong>the</strong>r residues.<br />

• Municipal and solid waste is being managed using more sustainable technologies. There is<br />

interest in developing <strong>the</strong>se technologies on one site, so that recycling, separation technologies<br />

or mechanical and biological treatment and anaerobic digestion is all integrated. NNFCC could<br />

examine <strong>the</strong> potential energy benefits in such trends and <strong>the</strong> impact <strong>the</strong>y may have on energy<br />

recovery from waste in general.<br />

1.6 System Overview<br />

An energy system based on <strong>the</strong> use of wastes and biomass is built up as a chain of several operations.<br />

Waste is collected, processed and delivered <strong>to</strong> a generating plant where it can be converted <strong>to</strong> heat,<br />

power or transport fuels. Each step is delivered <strong>by</strong> a different sec<strong>to</strong>r with its own priorities and<br />

constraints. The waste management industry prioritises safe and reliable disposal and has in <strong>the</strong> past<br />

selected technologies that guarantee this.<br />

Better matching of resources and end use should result in improved resource use efficiency and GHG<br />

mitigation as CHP installations can be sized <strong>to</strong> match heat loads and higher added value products are<br />

produced in cost effective installations that can use economy of scale.<br />

With <strong>the</strong> exception of conventional incineration all of <strong>the</strong> energy technologies require <strong>the</strong> feeds<strong>to</strong>ck <strong>to</strong> be<br />

treated <strong>to</strong> ensure a measure of consistency of composition and properties. In our opinion <strong>the</strong> conversion<br />

of waste components <strong>to</strong> consistent fuels will be a major fac<strong>to</strong>r in enabling more efficient alternatives <strong>to</strong> be<br />

deployed.


Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Fuels and Energy<br />

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Figure 2 Material and energy flows and appropriate technology<br />

Arisings Fuels Local scale<br />

applications<br />

MSW<br />

Bio Solids<br />

Commercial &<br />

Industrial<br />

wastes<br />

Forestry<br />

Residues<br />

Agricultural<br />

Residues<br />

Solid recovered<br />

fuels<br />

Graded waste<br />

wood fuel<br />

Clean grade chips<br />

Domestic grade<br />

pellets<br />

Industrial grade<br />

pellet<br />

AD for<br />

CHP and<br />

grid<br />

injection<br />

Commercial<br />

CHP and<br />

District heat<br />

Individual heating<br />

installations<br />

AD for<br />

CHP<br />

Regional scale<br />

applications<br />

Electricity only and<br />

CHP (incineration)<br />

Industrial CHP<br />

Methanation for<br />

grid<br />

Electricity only<br />

Biological 2 nd<br />

gen biofuel<br />

17<br />

National scale<br />

applications<br />

Gasification for<br />

Transport Biofuel<br />

Gasification<br />

and<br />

Methanation for<br />

pipeline gas<br />

Utility co<br />

firing


18<br />

Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Wastes and Energy<br />

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Table of contents<br />

1 Executive Summary 4<br />

1.1 The character and extent of <strong>the</strong> waste resource 5<br />

1.2 The status of those energy technologies with improved resource efficiency 8<br />

1.3 Risks and barriers <strong>to</strong> deployment 11<br />

1.4 Green house gas balances 15<br />

1.5 Challenges, issues and <strong>the</strong> role of NNFCC 15<br />

1.6 System Overview 16<br />

Glossary 20<br />

2 Introduction 22<br />

3 UK Waste Arisings 26<br />

3.1 Waste Categories Investigated 26<br />

3.2 Data Sources and Quality 27<br />

3.3 Overall waste arisings in <strong>the</strong> UK 28<br />

3.4 Growth Rates and Future Arisings 29<br />

4 Arisings <strong>by</strong> Waste Type 30<br />

4.1 Municipal Solid Wastes (MSW) 30<br />

4.2 Commercial and Industrial Wastes (C&I) 36<br />

4.3 Construction and Demolition (C&D) 41<br />

4.4 Bio-solids 45<br />

4.5 Agricultural Residues and Waste 50<br />

4.6 Forestry Residues 58<br />

4.7 Conclusions 67<br />

5 Arisings of components suitable for energy 69<br />

5.1 Waste Wood 69<br />

5.2 Food Waste 75<br />

5.3 Tallow 79<br />

5.4 Textiles Waste Arising 81<br />

5.5 Paper Waste Arisings 82<br />

5.6 Conclusions 85<br />

6 Waste Management Legislation and Incentives 88<br />

7 Solid recovered fuels and o<strong>the</strong>r fuels manufactured from waste 95<br />

7.1 Technologies for manufacturing fuels 96<br />

8 Supplying Energy from Waste <strong>by</strong> Combustion 108<br />

8.1 Process Description 108<br />

8.2 Review of UK and international waste combustion practice 112<br />

8.3 EfW Potential 121


Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Wastes and Energy<br />

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8.4 Conclusions for Combustion Technologies 123<br />

9 Biological Processes 126<br />

9.1 Anaerobic Digestion (AD) 126<br />

9.2 Composting - an alternative <strong>to</strong> Anaerobic Digestion 137<br />

9.3 Hydrolysis and fermentation of lignocellulose (Biological 2 nd Generation Biofuel)<br />

140<br />

9.4 Conclusions for Biological Processes 143<br />

10 Thermochemical processes for generating energy 144<br />

10.1 Gasification 145<br />

10.2 Pyrolysis 160<br />

10.3 Conclusions 165<br />

11 Potential GHG Reductions 166<br />

11.1 Scenario 1: Food Waste 167<br />

11.2 Scenario 2: Wood Waste 170<br />

11.3 O<strong>the</strong>r, recent GHG life cycle analyses 171<br />

12 Recommendations and NNFCC’s role 172<br />

Appendices<br />

Appendix 1 Fur<strong>the</strong>r information on Waste Arisings<br />

Appendix 2 Waste Legislation<br />

Appendix 3 MBT Methods<br />

19


Glossary<br />

20<br />

Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Wastes and Energy<br />

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Term Definition<br />

AD Anaerobic Digestion<br />

BERR Department for Business, Enterprise & Regula<strong>to</strong>ry Reform<br />

BFB Bubbling Fluidised Bed.<br />

BFM British Furniture Manufacturers<br />

BSE Bovine spongiform encephalopathy<br />

C Controlled waste<br />

C&D Construction and Demolition<br />

C&I Commercial and Industrial<br />

CA Civic Amenity<br />

CAD Centralised Anaerobic Digestion<br />

CEN European Committee for Standardisation<br />

CFB Circulating Fluidised Bed<br />

CHP Combined Heat and Power<br />

CLO Compost Like Output<br />

CNG Compressed Natural Gas<br />

CPI Centre for Process Innovation<br />

CSL Central Science Labora<strong>to</strong>ry<br />

CV Calorific Value<br />

Defra Department for <strong>the</strong> Environment, Food and Rural Affairs<br />

DTI Department for Trade and Industry<br />

EA Environment Agency<br />

EfW Energy from Waste<br />

EPRL Energy Power Resources Limited<br />

EU European Union<br />

EU-ETS European Union Energy Trading Scheme<br />

F Fluidised bed burners<br />

FAME Fatty Acid Methyl Ester<br />

FDF Food and Drink Federation<br />

FIRA Furniture Industry Research Association<br />

FYM Farm Yard Manure<br />

G Grate burner<br />

GDP Gross Domestic Product<br />

GHG Green House Gases<br />

IPPC Integrated Pollution and Prevention Control<br />

LHV Lower Heating Value<br />

MBM Meat and Bone meal<br />

MBT Mechanical Biological Treatment<br />

MHT Mechanical Heat Treatment<br />

MSW Municipal Solid Waste<br />

NC Non-controlled waste<br />

NNFCC National Non Food Crop Centre<br />

NVZ Nitrate Vulnerable Zones<br />

ODPM Office of <strong>the</strong> Deputy Prime Minister<br />

odt Oven Dried Tonnes<br />

OSR Oil seed rape<br />

pa Per annum<br />

PAHs Polycyclic Aromatic Hydrocarbons<br />

PCBs Poly Chlorinated Biphenyl


Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Wastes and Energy<br />

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PPC Pollution Prevention and Control<br />

R21 Recycling in <strong>the</strong> Twenty First Century<br />

RCEP Royal Commission on Environmental Pollution<br />

RDA Regional Development Agency<br />

REEIO Regional Economy Environment Input Output Model<br />

RESTATS Renewable Energy STATisticS database for <strong>the</strong> UK<br />

ROC Renewables Obligation Certificate<br />

RTFO Renewable Transport Fuel Obligation<br />

SEERAD Scottish Executive Environment Rural Affairs Department<br />

SEPA Scottish Environment Protection Agency<br />

SME Small and Medium sized Enterprises<br />

SNG Substitute Natural Gas<br />

SRF Solid Recovered Fuel<br />

SWMP Site Waste management Plan<br />

Syn-gas Syn<strong>the</strong>sis Gas (comprising principally hydrogen and carbon<br />

monoxide and used as a feeds<strong>to</strong>ck for chemical syn<strong>the</strong>sis.)<br />

TC Fuels Thermochemical Fuels (fuels prepared from pyrolysis or <strong>to</strong>rrefaction<br />

products)<br />

TRADA Timber Research and Development Association<br />

UK United Kingdom<br />

USA United States of America<br />

UWWT Urban Waste Water Treatment<br />

VS Volatile Solids<br />

WGs Working Groups<br />

WID Waste Incineration Directive<br />

WIP Waste Implementation Programme<br />

WRAP Waste and Resources Action Programme<br />

Wt Weight<br />

GJ Giga joules<br />

ha Hectares<br />

kg Kilograms<br />

kT Kilo <strong>to</strong>nnes<br />

Mt Mega <strong>to</strong>nnes<br />

MW Mega Watts<br />

t Tonnes<br />

TWh Tera Watt hours<br />

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2 Introduction<br />

The Prime Minister announced at <strong>the</strong> Labour Conference in September 2008 that he wants <strong>the</strong> current<br />

target of a 60 percent cut in carbon dioxide emissions <strong>by</strong> 2050, <strong>to</strong> be raised <strong>to</strong> 80 percent. He also called<br />

for an end <strong>to</strong> <strong>the</strong> dicta<strong>to</strong>rship of oil and a transformation in our use of energy. Cuts of this magnitude<br />

imply a step change in <strong>the</strong> energy infrastructure of <strong>the</strong> country, and <strong>the</strong> generation of energy and fuels<br />

from waste sources can play a major role in delivering this step change.<br />

The National Non-Food Crops Centre (NNFCC) is <strong>the</strong> UK's national centre for <strong>the</strong> development and<br />

support of renewable materials, technologies and fuels. It was established in 2003, and has al<strong>read</strong>y done<br />

considerable work <strong>to</strong> establish supply chains and markets for <strong>the</strong>se products.<br />

The NNFCC does not currently have a defined policy on waste. In order <strong>to</strong> develop this, it needs an up<strong>to</strong>-date<br />

picture of <strong>the</strong> current waste situation, and <strong>the</strong> opportunities for utilising this waste <strong>to</strong> generate<br />

energy and fuels.<br />

The NNFCC has tasked AEA with delivering such a study, which is an important element in developing its<br />

position in this area. The findings will enable <strong>the</strong> NNFCC <strong>to</strong> develop an appropriate and effective insight<br />

in<strong>to</strong> <strong>the</strong> waste situation and market in <strong>the</strong> UK, and how it might be used as a resource <strong>to</strong> derive energy<br />

and fuels. The NNFCC’s current focus is materials and energy from crops, and as a proportion of <strong>the</strong><br />

UK’s waste arisings originate from agricultural activities, <strong>the</strong> opportunity <strong>the</strong>refore exists <strong>to</strong> develop a<br />

strong and coherent position on <strong>the</strong> utilisation of <strong>the</strong>se wastes <strong>to</strong> generate energy and fuels.<br />

Sustainable development is a cause for increasing concern within <strong>the</strong> waste sec<strong>to</strong>r. The main concerns<br />

are focussed around:<br />

• global warming methane gas from landfill sites;<br />

• natural resource depletion, and;<br />

• local environmental pollution <strong>to</strong> land, water and air.<br />

The outcome of <strong>the</strong>se concerns has been <strong>the</strong> recognition at international, European and national levels<br />

that large-scale reliance on landfilling of waste is unsustainable. This has resulted in <strong>the</strong> introduction of<br />

legislation at both European and national levels that promotes a waste treatment hierarchy that places of<br />

waste prevention and minimisation as <strong>the</strong> most desirable option and disposal <strong>to</strong> landfill <strong>the</strong> least. This<br />

hierarchy is set out in <strong>the</strong> well known diagram below.


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Figure 3 Waste hierarchy 2<br />

In <strong>the</strong> current waste hierarchy, energy generation is one form of recovery. Such a classification<br />

recognises that many of <strong>the</strong> o<strong>the</strong>r options are, at present, more resource efficient than <strong>the</strong> technologies<br />

used <strong>to</strong> produce energy from waste. However, it is recognised that such classifications may alter in <strong>the</strong><br />

future as technologies that have better resource efficiencies become available. This <strong>report</strong> identifies <strong>the</strong>se<br />

technologies, outlines <strong>the</strong>ir potential and explores <strong>the</strong> barriers that may stand in <strong>the</strong> way of adoption.<br />

Anaerobic digestion, pyrolysis and gasification are typical of <strong>the</strong>se technologies and have <strong>the</strong> potential <strong>to</strong><br />

be more resource efficient ways of extracting energy and higher value products from waste. This can be<br />

in <strong>the</strong> form of electricity, combined heat and power, methane for transport fuel or grid injection, chemicals<br />

and liquid transport fuels. Although progress has been identified in <strong>the</strong> UK and elsewhere <strong>the</strong>se<br />

technologies remain technically less well developed than conventional methods and may demand a<br />

degree of upstream fuel preparation that will be innovative in <strong>the</strong> UK.<br />

To fulfil <strong>the</strong> objectives of <strong>the</strong> task set for this study we <strong>the</strong>refore need <strong>to</strong> understand a number of aspects<br />

of <strong>the</strong> current and future waste industry. The most important are<br />

• <strong>the</strong> character and extent of <strong>the</strong> waste resource,<br />

• <strong>the</strong> status of those energy technologies with improved resource efficiency,<br />

• <strong>the</strong> demands <strong>the</strong>y place on upstream waste management,<br />

• and <strong>the</strong> benefits that <strong>the</strong>ir adoption might bring.<br />

Our <strong>report</strong> is <strong>the</strong>refore structured as follows:<br />

Waste Arisings<br />

It is important <strong>to</strong> establish a baseline for <strong>the</strong> arisings of waste in <strong>the</strong> UK, particularly on a regional basis,<br />

as many of <strong>the</strong> potential solutions will require stable, locally sourced feed s<strong>to</strong>cks for a considerable<br />

number of years.<br />

Total arisings for <strong>the</strong> three categories of controlled wastes are well recorded, for Municipal Solid Waste<br />

(MSW), Commercial and Industrial waste (C&I) and Construction and Demolition waste (C&D). Within<br />

<strong>the</strong>se categories <strong>the</strong> composition proportions have been <strong>the</strong> focus of a number of studies, particularly for<br />

MSW. Wastes that do not fall within <strong>the</strong>se categories are less well recorded and studied, and<br />

consequently less accurate arisings figures are generated.<br />

2 Image taken from Waste in Context, Select Committee on Science and Technology Sixth Report, July 2008,<br />

http://www.publications.parliament.uk/pa/ld200708/ldselect/ldsctech/163/16305.htm<br />

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The waste arisings chapters have been set out as follows:<br />

• Chapter 3: UK Waste Arisings<br />

A summary of <strong>the</strong> UK waste categories in general and sub-categories frequently cited as suitable<br />

for conversion.<br />

• Chapter 4: Waste Arisings <strong>by</strong> Type<br />

A discussion of arisings on a regional basis of <strong>the</strong> main waste categories including MSW, C&I,<br />

C&D, Bio-solids, Agricultural Residues and Forestry Residues.<br />

• Chapter 5: Arisings of components suitable for energy<br />

An exploration of <strong>the</strong> waste materials commonly quoted as suitable <strong>to</strong> recover energy, but sp<strong>read</strong><br />

over a range of waste streams, including waste wood, waste food, tallow, textiles and paper and<br />

board.<br />

• Chapter 6: Waste Management Legislation and Incentives<br />

Legislation and incentives that affect <strong>the</strong> generation and treatment of wastes.<br />

Technology Options<br />

Chapters 7 <strong>to</strong> 10 describe how <strong>the</strong> waste can be converted <strong>to</strong> energy. They cover processes that supply<br />

heat, electricity, transport fuels and methane for injection <strong>to</strong> <strong>the</strong> national transmission system. These<br />

technologies are available at a range of sizes that make <strong>the</strong>m suitable for many locations and end users.<br />

The physical and chemical properties of <strong>the</strong> waste often determine <strong>the</strong> solution used for waste<br />

management. For example, at <strong>the</strong> moment <strong>the</strong> only energy recovery solution for <strong>the</strong> majority of wet<br />

wastes is anaerobic digestion. For dry wastes (e.g. waste wood) <strong>the</strong>rmal processes such as combustion<br />

are <strong>the</strong> best solution at present.<br />

The technology chapters have been set out as follows:<br />

• Chapter 7: Solid recovered fuels and o<strong>the</strong>r fuels manufactured from waste<br />

Processes and products that transform waste in<strong>to</strong> consistent tradable products.<br />

• Chapter 8: Energy from Waste using conventional <strong>the</strong>rmal processes<br />

Combustion for heat, combined heat and power and power only. Also co-firing with coal in a<br />

utility boiler.<br />

• Chapter 9: Energy from Waste using Biological Processes<br />

Anaerobic Digestion <strong>to</strong> produce power, CHP and gas for injection in<strong>to</strong> <strong>the</strong> national gas grid, with a<br />

comparison <strong>to</strong> composting, and <strong>the</strong> hydrolysis and fermentation of lignocellulosic material <strong>to</strong><br />

produce alcohols for transport fuels.<br />

• Chapter 10: Gasification and Pyrolysis processes for <strong>the</strong> generation of energy<br />

Thermal gasification for subsequent methanation and injection in<strong>to</strong> <strong>the</strong> national grid at both high<br />

and low pressures and gasification and pyrolysis for conversion <strong>to</strong> transport fuels or methane.<br />

Each chapter gives a brief description of <strong>the</strong> main technologies, with an indication of technical status,<br />

scale of operation, risks and barriers <strong>to</strong> deployment and <strong>by</strong>-products. Following this description we<br />

discuss <strong>the</strong> UK market situation and give examples of domestic and international practice. The rationale<br />

for <strong>the</strong> content is given below<br />

Chapter 11 considers two different waste materials, food waste and wood waste, and explores <strong>the</strong> GHG<br />

savings that could be achieved if <strong>the</strong>y were converted <strong>to</strong> energy ra<strong>the</strong>r than disposed of in <strong>the</strong> current<br />

way.<br />

Chapter 12 sets out our proposals <strong>to</strong> NNFCC for <strong>the</strong>ir possible future role in this area. Throughout <strong>the</strong><br />

<strong>report</strong> we identify areas of uncertainty, and specific challenges that need work if <strong>the</strong> <strong>full</strong> potential of<br />

energy from waste is <strong>to</strong> be realised. We believe NNFCC are ideally placed <strong>to</strong> contribute in a number of<br />

ways <strong>to</strong> facilitate <strong>the</strong>se changes.


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System Overview<br />

An energy system based on <strong>the</strong> use of wastes and biomass is built up as a chain of several operations.<br />

Waste is collected, processed and delivered <strong>to</strong> a generating plant where it can be converted <strong>to</strong> heat,<br />

power or transport fuels. Each step is delivered <strong>by</strong> a different sec<strong>to</strong>r with its own priorities and<br />

constraints.<br />

With <strong>the</strong> exception of conventional incineration all of <strong>the</strong> energy technologies require <strong>the</strong> feeds<strong>to</strong>ck <strong>to</strong> be<br />

treated <strong>to</strong> ensure a measure of consistency of composition and properties. In our opinion <strong>the</strong> conversion<br />

of waste components <strong>to</strong> consistent fuels will be a major fac<strong>to</strong>r in enabling more efficient alternatives <strong>to</strong> be<br />

deployed. We have <strong>the</strong>refore included a chapter describing <strong>the</strong> technologies used <strong>to</strong> manufacture <strong>the</strong>se<br />

fuels.<br />

Technical status<br />

The waste management industry prioritises safe and reliable disposal and has in <strong>the</strong> past selected<br />

technologies that guarantee this. Whilst for completeness we describe <strong>the</strong>se more conventional solutions<br />

this <strong>report</strong>, concentrates more on wastes as a resource from <strong>the</strong> point of view of energy and looks in<br />

more detail at those technologies with higher levels of energy efficiency.<br />

Scale of operation<br />

We consider that energy conversion technologies fall in<strong>to</strong> three broad categories depending on <strong>the</strong>ir scale<br />

of operation:<br />

Local, where <strong>the</strong> output is typically less than 2 MW and supplies small premises and industries.<br />

These operations are suitable for bulky or wet wastes or for smaller energy users that can use<br />

clean feeds<strong>to</strong>cks that do not bring with <strong>the</strong>m additional costs for regula<strong>to</strong>ry compliance or<br />

pollution control equipment. Typical technologies in this category are anaerobic digestion, and<br />

combustion for heat and small CHP.<br />

Regional where <strong>the</strong> output is typically less than 50MW and supplies major users, district heating<br />

networks and national electricity and gas networks at <strong>the</strong> distribution level. These operations are<br />

suitable for most wastes and include traditional incineration of municipal wastes. O<strong>the</strong>r<br />

technologies would be industrial scale CHP using combustion or gasification, merchant power<br />

stations and gasification and subsequent methanation for injection in<strong>to</strong> <strong>the</strong> natural gas distribution<br />

network at low pressure. Fuel supplies will typically be upgraded waste fuels and agricultural<br />

residues.<br />

National, where <strong>the</strong> output is typically over 50MW and supplies transport fuel and grid connected<br />

syn<strong>the</strong>tic natural gas and electricity. They are major infrastructure projects located on industrial<br />

complexes. The need <strong>to</strong> transport and s<strong>to</strong>re large quantities of fuel restricts <strong>the</strong> choice <strong>to</strong><br />

relatively dense products. Co-firing at a utility coal fired station also comes in this category.<br />

Risks and barriers<br />

Innovative processes in <strong>the</strong> waste management market face a wide range of technical and non technical<br />

risks and barriers <strong>to</strong> deployment. For each technology we discuss <strong>the</strong>se and <strong>the</strong> relationship with <strong>the</strong><br />

technical status.<br />

Examples of UK and international practice<br />

Many countries are ahead of <strong>the</strong> UK in implementing new technologies and <strong>the</strong>re is much <strong>to</strong> learn.<br />

Consequently we describe examples that demonstrate <strong>the</strong> application of new or strategically important<br />

technologies for energy from waste.<br />

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3 UK Waste Arisings<br />

In this chapter we bring <strong>to</strong>ge<strong>the</strong>r <strong>the</strong> current overall estimates of how much waste is produced annually in<br />

<strong>the</strong> UK, its composition and source. These basic figures are fundamental <strong>to</strong> an understanding of <strong>the</strong><br />

energy potential of <strong>the</strong> waste resource and <strong>the</strong> types of technologies that could be used <strong>to</strong> access it. We<br />

also discuss future trends and a methodology of waste categorisation that is more appropriate for energy<br />

use.<br />

3.1 Waste Categories Investigated<br />

The UK Government and <strong>the</strong> EU commonly group waste arisings in<strong>to</strong> <strong>the</strong> following categories:<br />

• Municipal Solid Waste (MSW)<br />

• Commercial and Industrial (C&I)<br />

• Construction and Demolition (C&D)<br />

• Bio-Solids (previously known as Sewage Sludge)<br />

• Agricultural Wastes<br />

• Dredged material<br />

• Minerals (Mining and Quarrying)<br />

While this level of breakdown is useful for identifying quantities and trends, it does not provide a break<br />

down for many of <strong>the</strong> waste streams that are of particular interest for this study.<br />

In this study <strong>the</strong> wastes that have been identified as having <strong>the</strong> potential for conversion <strong>to</strong> fuels and<br />

energy have been subdivided as follows:<br />

• Municipal Solid Wastes (MSW)<br />

• Commercial and Industrial wastes (C&I)<br />

• Construction and Demolition (C&D)<br />

• Bio-Solids (Sewage Sludge)<br />

• Agricultural<br />

o Wet residues<br />

o Dry residues<br />

• Forestry Residues<br />

Mineral and dredging wastes have not been covered, as <strong>the</strong>se waste streams have no practicable<br />

content that would be available for conversion <strong>to</strong> energy or fuels.<br />

A range of waste materials that are highly suitable for energy but <strong>the</strong>ir arisings are dispersed over several<br />

categories. An emerging trend is <strong>to</strong> combine resources from several streams as feeds<strong>to</strong>ck for an energy<br />

plant. We have considered <strong>the</strong>se dispersed arisings as a set of new subcategories. These are:<br />

• Food waste – arising from MSW and C&I waste<br />

• Wood waste – arising from MSW, C&I waste and C&D waste<br />

• Tallow – arising from C&I waste<br />

• Textile – arising from MSW and C&I waste<br />

• Paper and board – arising from MSW and C&I waste.<br />

In <strong>the</strong> following Sections <strong>the</strong>se waste streams and materials have been described in terms of a definition,<br />

<strong>the</strong> composition of each stream, and <strong>the</strong> arisings <strong>by</strong> region.


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3.2 Data Sources and Quality<br />

The information on waste arisings in this study has been obtained for a wide range of sources, such as<br />

<strong>the</strong> surveys conducted <strong>by</strong> <strong>the</strong> Environment Agency (EA) in England and Wales, and <strong>the</strong> Scottish<br />

Environmental Protection Agency in Scotland, National Agricultural Surveys, publicly available <strong>report</strong>s<br />

from <strong>the</strong> UK Government and Devolved Administrations, as well as many <strong>report</strong>s and surveys carried out<br />

<strong>by</strong> waste action groups. The specific data source is detailed and referenced at <strong>the</strong> point of discussion.<br />

Across <strong>the</strong> UK information on different types of waste is collected for a variety of reasons, and so data for<br />

one type of waste may not be directly comparable with ano<strong>the</strong>r type. For example data on MSW arisings<br />

is collected from <strong>the</strong> point of view of <strong>the</strong> source of arisings and management of <strong>the</strong> waste. Meanwhile<br />

some commercial and industrial wastes have data collected only from waste that has been treated, as <strong>the</strong><br />

treatment facility is registered. So <strong>the</strong>re are waste arisings potentially going unrecorded. It would be fair<br />

<strong>to</strong> say that, understandably, waste data has always been collected from <strong>the</strong> point of view of disposal as a<br />

nuisance ra<strong>the</strong>r than as an energy resource.<br />

The UK Government has recognised that a lack of information on <strong>the</strong> arisings of specific waste streams<br />

and <strong>the</strong>ir growth rates is hampering both <strong>the</strong> development of an effective waste strategy for household<br />

and o<strong>the</strong>r waste streams and <strong>the</strong> ability <strong>to</strong> measure and moni<strong>to</strong>r progress effectively. Consequently, as<br />

part of <strong>the</strong> Waste Implementation Programme (WIP), work on obtaining better data is being taken forward<br />

jointly with <strong>the</strong> Environment Agency <strong>to</strong> provide a sound evidence base for improved waste management<br />

policy development, implementation, moni<strong>to</strong>ring and evaluation at both national and local levels. 3<br />

The first part of WIP, which has al<strong>read</strong>y been implemented, is Waste Data Flow, which will provide<br />

quarterly data on arisings and management of municipal solid waste. The next phase is <strong>the</strong> Waste Data<br />

Strategy, which will include data on both commercial and industrial waste and construction and demolition<br />

waste, and started <strong>to</strong> produce data during 2007. A central principle of <strong>the</strong> data strategy is that costly<br />

surveys should be replaced wherever possible <strong>by</strong> better use of administrative data. In particular, better<br />

use should be made of data received <strong>by</strong> <strong>the</strong> Environment Agency from waste opera<strong>to</strong>rs as part of <strong>the</strong>ir<br />

permit requirements. The final phase will address agricultural, forestry, fishing, mines and quarries<br />

wastes, bio-solids and dredging spoils.<br />

Large scale industrial sites are covered <strong>by</strong> PPC (Pollution Prevention and Control permit), and <strong>the</strong><br />

Environment Agency has a list of all of <strong>the</strong>se sites, which include large scale incinera<strong>to</strong>rs and waste<br />

treatment facilities. PPC also covers recycling facilities, such as paper mills. The PPC thresholds for<br />

treatment plants (chemical, biological, <strong>the</strong>rmal) are 10 <strong>to</strong>nnes per day for hazardous waste and 50 <strong>to</strong>nnes<br />

per day for non-hazardous waste. Waste management licences cover facilities with lower capacities.<br />

The Environment Agency collect data from all facilities that have a waste management license. As <strong>the</strong>se<br />

include all landfill sites, <strong>the</strong>n good quality data on <strong>the</strong> amount of waste landfilled is available. However,<br />

<strong>the</strong>re are a number of gaps in <strong>the</strong> data on amount of material recycled. For example:<br />

• Paper merchants are exempt from Waste Management Licensing and are not required under<br />

<strong>the</strong> regulations <strong>to</strong> provide data.<br />

• Not all paper mills are covered <strong>by</strong> PPC, and PPC facilities currently do not have <strong>to</strong> provide<br />

data on <strong>the</strong> inputs of materials processed (if <strong>the</strong> paper mill is registered as an accredited<br />

reprocessor under <strong>the</strong> Packaging Regulations, <strong>the</strong>n data on <strong>the</strong> amount of packaging<br />

processed are available)<br />

• No data are collected on green list wastes (such as paper), which are exported for recycling<br />

from England and Wales (however, data on exported packaging are available).<br />

3 Delivering Data for Moni<strong>to</strong>ring Waste Strategy 2007, Defra 2008,<br />

http://www.defra.gov.uk/environment/statistics/wastedatahub/download/delivering_data_for_moni<strong>to</strong>ring_wastestrat07.pdf<br />

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There is also little data on <strong>the</strong> amount of C&D waste used at licensed exempt sites (sites which are<br />

registered as exempt from waste licensing requirements). 4 However, changes in PPC requirements<br />

mean that all sites will have <strong>to</strong> provide data on waste inputs, and proposed changes will require <strong>report</strong>ing<br />

of data on <strong>the</strong> amount of C&D waste used at registered exempt sites. These changes will improve <strong>the</strong><br />

quality of data on <strong>the</strong> amount of waste recycled when <strong>the</strong>y have been <strong>full</strong>y implemented, and <strong>to</strong>ge<strong>the</strong>r<br />

with o<strong>the</strong>r changes, should improve <strong>the</strong> overall quality of data on arisings of both C&I and C&D waste <strong>by</strong><br />

2012.<br />

3.3 Overall waste arisings in <strong>the</strong> UK<br />

The most recent and accurate UK wide estimates for waste arising are for 2004 and 2005. The <strong>to</strong>tal<br />

figure for 2004 is 335 million <strong>to</strong>nnes of waste, 5 while estimates for 2005 put <strong>the</strong> figure at 307 million<br />

<strong>to</strong>nnes of waste. 6 Figure 4 shows <strong>the</strong> estimated proportion produced <strong>by</strong> each sec<strong>to</strong>r. This includes nearly<br />

100 million <strong>to</strong>nnes of minerals waste from mining and quarrying, which is not subject <strong>to</strong> control under <strong>the</strong><br />

EU Waste Framework Directive, and 220 million <strong>to</strong>nnes of controlled wastes from households, commerce<br />

and industry (including construction and demolition wastes). Household wastes represent about 9 percent<br />

of <strong>to</strong>tal arisings.<br />

Figure 4: Arisings of waste in <strong>the</strong> UK in 2004<br />

Estimates shown in <strong>the</strong> chart are mainly based on data for 2004 except for estimates of bio-solids which<br />

relate <strong>to</strong> 2005 and construction and demolition waste which relate <strong>to</strong> 2002/03. The figure for construction<br />

and demolition wastes includes excavated soil and miscellaneous materials as well as hard materials,<br />

such as brick, concrete and road planings.<br />

4 Registered Exempt sites are sites which are notified <strong>by</strong> <strong>the</strong> site opera<strong>to</strong>r as being exempt from waste management licensing (though not exempt from<br />

waste regulation) and where this exemption has been placed on <strong>the</strong> public register <strong>by</strong> <strong>the</strong> Environment Agency.<br />

5 Key facts about Waste and Recycling, Defra, http://www.defra.gov.uk/environment/statistics/waste/kf/wrkf02.htm<br />

6 Defra Environmental Statistics, www.defra.gov.uk/environment/statistics/waste/download/xls/wsr_data_2006.xls


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Wastes from mining, quarrying, and dredged material contain no usable material and will not be<br />

considered fur<strong>the</strong>r in this <strong>report</strong>.<br />

Waste from <strong>the</strong> agriculture sec<strong>to</strong>r represents less than 1% of <strong>to</strong>tal arisings. This waste, which excludes<br />

manures or straw, and covers items such as packaging, silage plastics and unused pesticides, came<br />

under <strong>the</strong> same legislative controls as o<strong>the</strong>r controlled wastes in May 2006. The arisings of manure and<br />

slurry were estimated as 45 million <strong>to</strong>nnes in 2002/03. If this waste is included in <strong>to</strong>tal waste arisings,<br />

<strong>the</strong>n <strong>the</strong> <strong>to</strong>tal amount of waste produced in <strong>the</strong> UK in 2004 was 380 million <strong>to</strong>nnes.<br />

O<strong>the</strong>r wastes, which include forestry wastes and fishing wastes, represent about 1% of <strong>to</strong>tal waste<br />

arisings.<br />

Table 3 presents <strong>the</strong> most recent published data for arisings of MSW, C&I waste and C&D waste in<br />

England, Wales 7 , Scotland and Nor<strong>the</strong>rn Ireland. The <strong>to</strong>tal arisings of <strong>the</strong>se waste streams is 236 million<br />

<strong>to</strong>nnes per annum. England produced 79% of <strong>the</strong> <strong>to</strong>tal arisings of <strong>the</strong>se waste streams, and MSW<br />

represents about 15% of <strong>the</strong>se waste streams.<br />

Table 3: Waste arisings (‘000,000 <strong>to</strong>nnes) in <strong>the</strong> UK<br />

England Wales Scotland 8 Nor<strong>the</strong>rn<br />

Ireland<br />

Total<br />

MSW 28.5 9 1.8 10 3.0 1.1 11 34.4<br />

C&I waste 67.9 12 5.3 13 7.8 1.6 14 82.6<br />

C&D waste 89.6 15 12.2 16 11.8 5.0 17 118.6<br />

Total 186.0 19.3 22.6 7.7 235.6<br />

3.4 Growth Rates and Future Arisings<br />

In order <strong>to</strong> plan for future waste management requirements, it is clearly important <strong>to</strong> be able <strong>to</strong> estimate<br />

future waste arisings. These can be determined <strong>by</strong> applying growth rates <strong>to</strong> <strong>the</strong> estimates of current<br />

waste arisings.<br />

His<strong>to</strong>rically, waste arisings have been shown <strong>to</strong> grow in line with, or even above, <strong>the</strong> level of economic<br />

growth. Consequently, if this trend continues, a 3% pa. growth in waste would result a doubling of waste<br />

arisings in 20 years. However, <strong>the</strong> continuation of this trend is now considered <strong>to</strong> be unsustainable, and<br />

thus <strong>the</strong> sixth Environment Action Programme 18 set an objective <strong>to</strong> achieve a decoupling of resource use<br />

from economic growth through significantly improved resource efficiency, dematerialisation of <strong>the</strong><br />

economy and waste prevention.<br />

7 A new survey <strong>to</strong> determine C&I waste arisings in Wales is currently being conducted; <strong>the</strong> findings are expected <strong>to</strong> be published <strong>by</strong> Summer 2009.<br />

8 Waste Data Digest 8: Key facts and trends. Scottish Environmental Protection Agency, 2008<br />

9 Defra - http://www.defra.gov.uk/environment/statistics/wastats/bulletin08.htm<br />

10 Municipal Waste Management Report for Wales, 2007-08. Statistics for Wales, Oc<strong>to</strong>ber 2008<br />

11 Municipal Waste Management Nor<strong>the</strong>rn Ireland 2005/06 Summary Report, December 2006<br />

12 Environment Agency 2006 – Strategic Waste Management Assessment 2002/03<br />

13 Environment Agency Wales, http://www.environment-agency.gov.uk/aboutus/organisation/35675.aspx<br />

14 Commercial & Industrial Waste Arisings Survey 2004/05. Environment & Heritage Service, March 2007<br />

15 Survey of Arisings and Use of Alternatives <strong>to</strong> Primary Aggregates in England, 2005; Construction, Demolition and Excavation Waste. Report for<br />

Department for Communities and Local Government <strong>by</strong> Capita Symonds Ltd, in association with WRc plc, February 2008<br />

16 Survey on <strong>the</strong> arising and management of construction and demolition waste in Wales in 2005-06. Environment agency Wales<br />

17 Construction and demolition waste survey. Environment and Heritage Service (EHS), 2004<br />

18 The Sixth Environment Action Programme of <strong>the</strong> European Community 2002-2012, http://ec.europa.eu/environment/newprg/index.htm<br />

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4 Arisings <strong>by</strong> Waste Type<br />

In this Chapter we consider <strong>the</strong> <strong>to</strong>tal arisings for <strong>the</strong> major wastes and residues on a national and regional<br />

basis. We discuss <strong>the</strong>se in this chapter according <strong>to</strong> <strong>the</strong>ir origin.<br />

The waste streams considered are: Municipal Solid Wastes (MSW); Commercial and Industrial wastes<br />

(C&I); Construction and Demolition (C&D); Bio-solids; Agricultural residues, both Wet and Dry residues,<br />

and; Forestry Residues.<br />

The regional subdivisions used were <strong>the</strong> 9 regional development areas for England, as well as <strong>the</strong><br />

devolved regions of Scotland, Wales and Nor<strong>the</strong>rn Ireland. Where reliable information is available, <strong>the</strong><br />

disposal route used <strong>by</strong> each region for <strong>the</strong> wastes and residues has also been discussed, although <strong>the</strong>re<br />

is little information for many waste streams.<br />

4.1 Municipal Solid Wastes (MSW)<br />

4.1.1 Definition<br />

Municipal Solid Waste, commonly referred <strong>to</strong> as MSW is waste collected <strong>by</strong>, or on behalf of, a local<br />

authority, which has a legal duty <strong>to</strong> manage such wastes. MSW is comprised of:<br />

• household waste<br />

• civic amenity waste<br />

• recycling centre arisings<br />

• street litter<br />

• fly-tipped waste<br />

• commercial waste collected <strong>by</strong> local authorities.<br />

52%<br />

10%<br />

10%<br />

4%<br />

24%<br />

Figure 5 Sources of Municipal Waste<br />

Non-household sources<br />

O<strong>the</strong>r Household<br />

sources<br />

Household recycled<br />

Civic amenity sites


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4.1.2 Composition<br />

As MSW comprises largely of household wastes, a considerable range of materials are included, for<br />

example food waste, garden waste, plastics, metals and paper are commonly present. In addition<br />

domestic hazardous and <strong>to</strong>xic waste may also be present, such as medication, paints, fluorescent tubes,<br />

spray cans, and batteries <strong>to</strong> name only a few. Table 4 shows a detailed breakdown of constituent<br />

materials, taken from a survey conducted in Wales, which could be considered typical of <strong>the</strong> UK. 19<br />

Table 4 Composition of MSW<br />

Waste Category Weight Weight<br />

Suitable for <strong>the</strong>rmal processes<br />

(‘000 <strong>to</strong>nnes) (%)<br />

Newspapers and magazines 147.3 9.0<br />

Recyclable paper 34.0 2.1<br />

Cardboard boxes/containers 84.4 5.1<br />

O<strong>the</strong>r paper and card 79.2 4.8<br />

Refuse sacks and carrier bags 20.5 1.3<br />

Packaging film 22.1 1.3<br />

O<strong>the</strong>r plastic film 3.0 0.2<br />

Dense plastic bottles 27.1 1.7<br />

O<strong>the</strong>r packaging 24.3 1.5<br />

O<strong>the</strong>r dense plastic 22.2 1.3<br />

Textiles 30.3 1.8<br />

Shoes 5.9 0.4<br />

Disposable nappies 37.7 2.3<br />

Wood 46.3 2.8<br />

Carpet and underlay 23.9 1.5<br />

Furniture 24.3 1.5<br />

O<strong>the</strong>r miscellaneous combustibles 59.8 3.6<br />

Total<br />

Suitable for composting or <strong>the</strong>rmal<br />

692.3 42.2<br />

Garden waste<br />

Suitable for AD or composting<br />

208.7 12.7<br />

Kitchen waste 257.1 15.7<br />

O<strong>the</strong>r organics 34.3 2.1<br />

Total<br />

Not suitable for energy recovery<br />

291.4 17.8<br />

Packaging glass 87.0 5.3<br />

Non-packaging glass 8.1 0.5<br />

Ferrous food and beverage cans 27.8 1.7<br />

O<strong>the</strong>r ferrous metal 51.6 3.1<br />

Non-ferrous food and beverage cans 5.6 0.3<br />

O<strong>the</strong>r non ferrous metal 7.7 0.5<br />

White goods 13.9 0.8<br />

Large electronic goods 3.1 0.2<br />

TVs and moni<strong>to</strong>rs 4.8 0.3<br />

O<strong>the</strong>r WEEE 10.9 0.7<br />

Lead/acid batteries 3.7 0.2<br />

Oil 1.0 0.1<br />

Identifiable clinical waste 2.7 0.2<br />

O<strong>the</strong>r potentially hazardous items 5.0 0.3<br />

Construction and demolition waste 85.9 5.2<br />

O<strong>the</strong>r MNC 45.3 2.8<br />

Fines 86.0 5.1<br />

Total 450.1 27.3<br />

As can be seen <strong>the</strong>re are substantial quantities of material that are suitable for energy use ei<strong>the</strong>r <strong>by</strong><br />

<strong>the</strong>rmal processes or anaerobic digestion.<br />

19 The composition of municipal solid waste in Wales. Report <strong>by</strong> AEA for <strong>the</strong> Welsh Assembly Government, December 2003.<br />

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4.1.3 Current Arisings on a National and Regional basis<br />

MSW currently represents approximately 9% of <strong>to</strong>tal waste arisings. Final estimates of municipal waste<br />

arisings and management for England and <strong>the</strong> regions in 2007/8 were published in November 2008. 20<br />

Table 5 shows <strong>the</strong> arisings of MSW in each of <strong>the</strong> English regions in 2007/08. The South East has <strong>the</strong><br />

highest arisings, followed <strong>by</strong> London. The latest MSW arisings data for Nor<strong>the</strong>rn Ireland, Scotland and<br />

Wales are also shown below in Table 5, and allow an overview of <strong>the</strong> UK MSW arisings <strong>to</strong> be presented.<br />

Table 5: MSW arisings in <strong>the</strong> UK <strong>by</strong> region and Country in 2007/08<br />

Region MSW Arisings<br />

(‘000 <strong>to</strong>nnes)<br />

East Midlands 2,413<br />

East of England 3,034<br />

London 4,154<br />

North East 1,512<br />

North West 4,052<br />

South East 4,563<br />

South West 2,929<br />

West Midlands 2,984<br />

Yorkshire and Humber 2,865<br />

England - Total 28,507<br />

Nor<strong>the</strong>rn Ireland 1,100 21<br />

Scotland 3,000 22<br />

Wales 1,800 23<br />

UK - Total 34,400<br />

Although <strong>the</strong> recycling rate has increased (see Table 6), 62% of MSW arisings in England are currently<br />

landfilled. 24<br />

Table 6 MSW Recycling Rate<br />

Year England<br />

(Wt %)<br />

Wales<br />

(Wt %)<br />

Scotland<br />

(Wt %)<br />

Nor<strong>the</strong>rn<br />

Ireland<br />

(Wt %)<br />

2000/01 12.3 - - -<br />

2001/02 14.0 8.4 - -<br />

2002/03 16.0 12.5 8.0 -<br />

2003/04 19.0 17.7 12.1 -<br />

2004/05 23.5 21.7 17.5 18.2<br />

2005/06 27.2 25.5 24.4 23.2<br />

2006/07 30.6 29.9 28.5 25.5<br />

2007/08 34.0 33.6 Report due in Report due in<br />

* Not published yet<br />

2009* 2009*<br />

A significant proportion of MSW is now recycled. The increase in <strong>the</strong> recycling rate is due <strong>to</strong> both<br />

Government recycling targets and <strong>the</strong> need for local authorities <strong>to</strong> meet <strong>the</strong> 2010 target for landfilling<br />

20 Defra Statistical Release 352/08, http://www.defra.gov.uk/environment/statistics/wastats/archive/mwb200708_statsrelease.pdf<br />

21 Municipal Waste Management Nor<strong>the</strong>rn Ireland 2005/06 Summary Report, December 2006<br />

22 Waste Data Digest 8: Key facts and trends. Scottish Environmental Protection Agency, 2008<br />

23 Municipal Waste Management Report for Wales, 2007-08. Statistics for Wales, Oc<strong>to</strong>ber 2008<br />

24 Results from WasteDataFlow http://www.defra.gov.uk/environment/statistics/wastats/bulletin.htm


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biodegradable waste. The increase in recycling rates is mainly due <strong>to</strong> <strong>the</strong> introduction of kerbside<br />

collection schemes for dry recyclable materials (paper, glass, metal and plastic) and garden waste.<br />

Increasing <strong>the</strong> recycling rate <strong>to</strong> <strong>the</strong> 2020 target of 50% will require large-scale collection of food waste<br />

from households; <strong>the</strong> England waste strategy promotes this because of both landfill gas reduction and<br />

energy recovery if food waste is treated using anaerobic digestion.<br />

Table 7 shows <strong>the</strong> arisings and management of MSW in each of <strong>the</strong> English regions in 2007/08. This<br />

table illustrates <strong>the</strong> considerable variations in <strong>the</strong> pattern of waste management as a result of population,<br />

socio economic fac<strong>to</strong>rs and policy. For example, London has <strong>the</strong> lowest recycling rate in percentage<br />

terms but has a high <strong>to</strong>nnage, while <strong>the</strong> South West has <strong>the</strong> highest percentage rate but lower <strong>to</strong>nnage<br />

A <strong>to</strong>tal of about 10 million <strong>to</strong>nnes of MSW arisings in England were ei<strong>the</strong>r recycled or composted in<br />

2007/08.<br />

Table 7 Management of MSW in English regions in 2007/08<br />

Region MSW Arisings<br />

(‘000 <strong>to</strong>nnes)<br />

Recycled or<br />

Composted<br />

(Wt %)<br />

Energy<br />

Recovery<br />

(Wt %)<br />

Landfilled<br />

(Wt %)<br />

East Midlands 2,413 40 7 53<br />

East of England 3,034 40 2 58<br />

London 4,154 22 22 56<br />

North East 1,512 29 13 58<br />

North West 4,052 36 2 62<br />

South East 4,563 37 12 51<br />

South West 2,929 41 - 59<br />

West Midlands 2,984 32 30 38<br />

Yorkshire and Humber 2,865 30 10 60<br />

England - Total 28,507 34 11 55<br />

Nor<strong>the</strong>rn Ireland 1,100 28 - -<br />

Scotland 3,000 32 2 66<br />

Wales 1,800 33 1 65<br />

UK- Total 34,407 127 - -<br />

The amount of waste which is landfilled will reduce due <strong>to</strong> both fur<strong>the</strong>r increases in recycling rate and <strong>the</strong><br />

increasing capacity for waste treatment which will enable local authorities <strong>to</strong> meet <strong>the</strong> 2013 and 2020<br />

targets set <strong>by</strong> <strong>the</strong> Landfill Directive (this will also increase <strong>the</strong> percentage of waste which has energy<br />

recovered from it).<br />

4.1.4 Growth Rates and Future trends<br />

The growth in household waste (and hence MSW) is due <strong>to</strong> two key fac<strong>to</strong>rs:<br />

• An increase in <strong>the</strong> number of households, and<br />

• Growth in waste produced per household due <strong>to</strong> increased consumption.<br />

Waste minimisation and re-use initiatives 25 aim <strong>to</strong> tackle <strong>the</strong> growth in waste produced <strong>by</strong> a household.<br />

However, even if <strong>the</strong>se initiatives were <strong>to</strong> reduce <strong>the</strong> growth in waste per household <strong>to</strong> zero, <strong>the</strong>n arisings<br />

of household waste would still increase as a result of an increase in <strong>the</strong> number of households.<br />

25 International Waste Prevention and Reduction Practice: Final Report. Report <strong>by</strong> Enviros for Defra, Oc<strong>to</strong>ber 2004.<br />

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One European study has assessed <strong>the</strong> fac<strong>to</strong>rs affecting household consumption, and <strong>the</strong> effects on <strong>the</strong><br />

environment (resource use, energy use and waste). 26 Ano<strong>the</strong>r European study developed a model which<br />

assesses <strong>the</strong> effects of food, recreation, ‘infotainment’, care, clothing, and housing on waste growth and<br />

used this <strong>to</strong> model four scenarios which all assumed continued economic growth but had different future<br />

lifestyles. 27 The results of both showed that waste continued <strong>to</strong> grow - sometimes considerably higher<br />

than GDP growth rate, sometimes in line with GDP growth rate, and sometimes at lower than GDP growth<br />

rates.<br />

Data on MSW arisings from a number of European countries from 1997 <strong>to</strong> 2003 indicate that in some<br />

countries (e.g. Belgium and <strong>the</strong> Ne<strong>the</strong>rlands) waste arisings are growing more slowly than GDP growth. 28<br />

The data also suggests that countries that have higher MSW recycling rates are seeing lower growth<br />

rates in MSW arisings; this may be because <strong>the</strong> impacts due <strong>to</strong> many years of publicity/education<br />

information on waste awareness and recycling are now becoming noticeable. However, this trend does<br />

not appear <strong>to</strong> be evident in ei<strong>the</strong>r France or Germany.<br />

Figure 6 shows that <strong>the</strong> arisings of MSW in England increased from 24.6 million <strong>to</strong>nnes in 1996/97 <strong>to</strong> 29.4<br />

million <strong>to</strong>nnes in 2002/03. This represents an average growth rate of about 3% per annum. However,<br />

<strong>the</strong>re has been little growth in arisings since <strong>the</strong>n; <strong>the</strong> overall arisings of 29.1 million <strong>to</strong>nnes in 2006/07<br />

were lower than <strong>the</strong> arisings of 29.4 million <strong>to</strong>nnes in 2002/03, and <strong>the</strong> arisings in 2007/08 reduced <strong>to</strong><br />

28.5 million <strong>to</strong>nnes, which was lower than that in 2001/02.<br />

Million <strong>to</strong>nnes of MSW<br />

35,000<br />

30,000<br />

25,000<br />

20,000<br />

15,000<br />

10,000<br />

5,000<br />

0<br />

1996/97<br />

1997/98<br />

1998/99<br />

1999/2000<br />

2000/01<br />

2001/02<br />

2002/03<br />

Year<br />

2003/04<br />

2004/05<br />

2005/06<br />

Figure 6: MSW arisings (‘000 <strong>to</strong>nnes) in England 1996/97 <strong>to</strong> 2007/08<br />

Although MSW arisings grew at an average of 3% per annum from 1997/98 <strong>to</strong> 2000/2001, <strong>the</strong> average<br />

rate of growth since <strong>the</strong>n is now averaging less than 1% per annum. There are a number of possible<br />

reasons for this lower growth rate:<br />

• Waste minimisation campaigns (<strong>the</strong>se usually take at least 5 years <strong>to</strong> show any noticeable effect)<br />

• Lower arisings of garden waste collected due <strong>to</strong> a combination of dryer summers and an increase<br />

in <strong>the</strong> amount of material that is home composted<br />

• Restrictions placed on <strong>the</strong> types of waste taken <strong>to</strong> <strong>the</strong> household waste recycling centres.<br />

2006/07<br />

26 Household Consumption and <strong>the</strong> Environment. European Environment Agency Report 11/2005.<br />

27 Scenarios of Household Waste Generation in 2020. Report <strong>by</strong> Joint Research Centre for <strong>the</strong> European Commission, June 2003.<br />

28 Eurostat - ec.europa.eu/eurostat<br />

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There are a number of predictions for future MSW arisings:<br />

• A model created <strong>by</strong> <strong>the</strong> Future Foundation in 2006 assessed <strong>the</strong> impact of lifestyle changes on<br />

household waste arisings in <strong>the</strong> UK. 29 This model has a base case scenario in which waste<br />

quantities grow at an average of over 2% per annum from 2005 <strong>to</strong> 2020.<br />

• Ano<strong>the</strong>r model <strong>by</strong> Oakdene Hollins in 2005 predicted future waste arisings based on national<br />

waste strategies and <strong>the</strong> need <strong>to</strong> meet various legislative targets. 30 This model has a base case<br />

growth rate of 2% per annum from 2005 <strong>to</strong> 2020.<br />

These models predict average growth rates of between 1% and 2% per annum, and <strong>the</strong> Waste Strategy<br />

2007 developed four growth scenarios for MSW in order <strong>to</strong> assess a range of possible future outcomes <strong>to</strong><br />

2020:<br />

1. 2.25% per annum reflecting recent trends in growth in consumer spending;<br />

2. 1.5% per annum in line with national waste growth in <strong>the</strong> five years <strong>to</strong> 2004/05;<br />

3. 0.75% per annum, in line with current projections of household growth and reflecting more closely<br />

national waste growth in <strong>the</strong> five years <strong>to</strong> 2005/06; and<br />

4. 0% growth, representing <strong>the</strong> possibility that waste growth will be decoupled from household and<br />

economic growth.<br />

It is unlikely that scenario 4 (0% growth) will occur due <strong>to</strong> Government policy regarding future house<br />

building (even if a waste minimisation programme reduces <strong>the</strong> level of growth of waste in a household <strong>to</strong><br />

0%, <strong>the</strong> arisings of MSW will increase because of <strong>the</strong> increase in <strong>the</strong> number of houses). 31 It is also<br />

unlikely that scenario 1 (2.25% growth) will occur due <strong>to</strong> <strong>the</strong> emphasis on future waste minimisation in <strong>the</strong><br />

new national waste strategy. Consequently, most growth forecasts use growth rates for MSW of 0.75%<br />

per annum as this reflects Scenario 3 in <strong>the</strong> national waste strategy, and this growth rate has been used<br />

<strong>to</strong> estimate future arisings of this stream.<br />

One type of waste that is now covered <strong>by</strong> European and UK legislation with <strong>the</strong> aim of reducing <strong>the</strong><br />

amount sent <strong>to</strong> landfill is biodegradable waste. The intention here is <strong>to</strong> reduce <strong>the</strong> uncontrolled release of<br />

greenhouse gas emissions in<strong>to</strong> atmosphere. The Landfill Directive also requires waste <strong>to</strong> be pre-treated<br />

prior <strong>to</strong> disposal. This has significant implications for energy applications as such waste will be available<br />

as a segregated feeds<strong>to</strong>ck, potentially advantageously pre-treated.<br />

4.1.5 Conclusion<br />

In <strong>to</strong>tal <strong>the</strong> UK produced 34.4 million <strong>to</strong>nnes of MSW in 2008. UK local authorities have significant targets<br />

<strong>to</strong> meet in terms of recording information, segregating and recycling <strong>the</strong> waste and landfill diversion.<br />

Largely due <strong>to</strong> <strong>the</strong>se requirements on <strong>the</strong> local authorities this waste stream is one of <strong>the</strong> best recorded<br />

and unders<strong>to</strong>od.<br />

There has been little growth in <strong>the</strong> volume of MSW produced in <strong>the</strong> UK since 2002, thought <strong>to</strong> be due <strong>to</strong> a<br />

combination of recycling schemes, reduced garden wastes due <strong>to</strong> dryer summers and increased controls<br />

on disposals accepted at civic amenity sites.<br />

MSW contains a wide range of materials, although this range is decreasing as recycling initiatives<br />

become more wide sp<strong>read</strong> and more material diverse. Although recycling rates continue <strong>to</strong> increase<br />

each year overall, 62% of MSW is still currently landfilled in England.<br />

29<br />

Modelling <strong>the</strong> Impact of Lifestyle Changes on Household Waste Arisings in <strong>the</strong> UK. Report <strong>by</strong> <strong>the</strong> Future Foundation and Social Marketing Practice<br />

for Defra 2006.<br />

30<br />

Quantification of <strong>the</strong> Potential Energy from Residuals (EfR) in <strong>the</strong> UK. Report <strong>by</strong> Oakdene Hollins for The Institution of Civil Engineers and The<br />

Renewable Power Association, March 2005.<br />

31 Opinion of internal AEA expert.<br />

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Most growth forecasts use growth rates for MSW of 0.75% per annum as this reflects Scenario 3 in <strong>the</strong><br />

national waste strategy. This suggests that MSW will be a stable source of feeds<strong>to</strong>ck for energy in <strong>the</strong><br />

foreseeable future.<br />

Increasing <strong>the</strong> recycling rate <strong>to</strong> <strong>the</strong> 2020 target of 50% will require large-scale collection of food waste<br />

from households; <strong>the</strong> England waste strategy promotes this because of both landfill gas reduction and<br />

energy recovery if food waste is treated using anaerobic digestion. This is a significant opportunity <strong>to</strong><br />

recover renewable energy.<br />

4.2 Commercial and Industrial Wastes (C&I)<br />

4.2.1 Definition<br />

Commercial and Industrial wastes are those arising from premises used for industry, trade or business.<br />

In 2002/3 Industrial and Commercial waste in England <strong>to</strong>talled 68 million <strong>to</strong>nnes. Of this about 38 million<br />

<strong>to</strong>nnes was attributable <strong>to</strong> industry and 30 million <strong>to</strong> commerce.<br />

4.2.2 Composition<br />

The individual sec<strong>to</strong>r that produced <strong>the</strong> most waste was <strong>the</strong> retail sec<strong>to</strong>r, which generated nearly 13<br />

million <strong>to</strong>nnes of waste. This was followed <strong>by</strong> food, drink and <strong>to</strong>bacco manufacturing, and <strong>the</strong> professional<br />

services and o<strong>the</strong>r businesses, both producing more than 7 million <strong>to</strong>nnes, and <strong>the</strong> coke, oil, gas,<br />

electricity and water industries at just over 6 million <strong>to</strong>nnes.<br />

Table 8 Commercial and Industrial waste arisings 2002-3 for England and Wales<br />

Type of Industrial Waste C&I Arisings<br />

(‘000 <strong>to</strong>nnes)<br />

Manufacture of pulp, paper and paper products 1,800<br />

Food, drink and <strong>to</strong>bacco 7,200<br />

Textiles, lea<strong>the</strong>r goods 1,200<br />

Wood and wood products (inc. furniture) 2,000<br />

Publishing, printing and recording 2,200<br />

Production of coke, electricity, oil, gas and water 6,200<br />

Manufacture of metals, fabricated metal and<br />

machinery and equipment<br />

7,700<br />

Manufacture of mo<strong>to</strong>r vehicles and o<strong>the</strong>r transport<br />

1,500<br />

equipment<br />

O<strong>the</strong>r non-metallic mineral products 2,300<br />

Retail, including mo<strong>to</strong>r vehicles, parts and fuel 12,800<br />

Hotels, catering 3,400<br />

Transport, s<strong>to</strong>rage and communications 2,200<br />

Commercial business, finance, real estate and<br />

7,200<br />

computer related activities<br />

Public administration and social work 1,400<br />

Chemical and o<strong>the</strong>r 5,300<br />

Education 1,900<br />

Miscellaneous 1,500<br />

Total 67.9


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This demonstrates that industrial and commercial wastes contain a vast range of materials, and that<br />

discussing <strong>the</strong>m as a single homogenous mass can be misleading. Table 9 gives more detail about <strong>the</strong><br />

possible content of commercial and industrials wastes, based on an Environment Agency survey covering<br />

England and Wales.<br />

Table 9: Composition (‘000 <strong>to</strong>nnes) of commercial and industrial waste in England<br />

Commercial Industrial Total<br />

Chemicals 1,942 5,692 7,634<br />

Metallic 604 2,727 3,330<br />

Non-metallic 8,651 5,181 13,833<br />

Discarded equipment 262 88 350<br />

Animal & plant 2,152 4,143 6,295<br />

Mixed/general waste 15,569 6,056 21,625<br />

Common sludges 154 761 915<br />

Mineral wastes 987 12,939 13,926<br />

Total 30,320 37,587 67,907<br />

Table 9 shows that:<br />

• Mixed/general waste is <strong>the</strong> largest category, representing 32% of <strong>to</strong>tal C&I arisings (a figure<br />

of 37% was determined for <strong>the</strong> survey in Nor<strong>the</strong>rn Ireland), and 50% of commercial waste<br />

arisings<br />

• Mineral wastes represent about 20% of <strong>to</strong>tal C&I arisings. This includes 6 million <strong>to</strong>nnes per<br />

annum of ash from pulverised coal fired power stations, of which about 3 million <strong>to</strong>nnes is<br />

currently being recycled. 32<br />

• Non-metallic wastes represent about 20% of <strong>to</strong>tal C&I arisings. This category includes<br />

recycled paper/cardboard, and over 85% of <strong>the</strong> <strong>to</strong>tal arisings of this category are recycled.<br />

32 The current classification of pulverised fuel ash as a waste is <strong>the</strong> main reason why only about 50% of it is currently recycled. The Waste Pro<strong>to</strong>cols<br />

Project is currently considering whe<strong>the</strong>r <strong>the</strong> ash could be classified as a product for specified recycling uses<br />

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4.2.3 Current Waste Arisings<br />

Table 10 shows <strong>the</strong> arisings of commercial and industrial waste in each of <strong>the</strong> English regions in 2002/03.<br />

London and <strong>the</strong> South East had <strong>the</strong> highest arisings of commercial waste, and Yorkshire and Humber<br />

had <strong>the</strong> highest arisings of industrial waste.<br />

Table 10: Arisings of commercial and industrial waste <strong>by</strong> English Region and Country in 2002/03<br />

Region Commercial<br />

Waste<br />

(‘000 <strong>to</strong>nnes)<br />

Industrial<br />

Waste<br />

(‘000 <strong>to</strong>nnes)<br />

Commercial and<br />

Industrial Waste<br />

(‘000 <strong>to</strong>nnes)<br />

East Midlands 2,322 5,171 8,093<br />

East of England 3,308 3,256 6,564<br />

London 5,604 1,902 7,507<br />

North East 1,199 3,400 4,599<br />

North West 3,833 4,502 8,335<br />

South East 5,271 3,581 8,852<br />

South West 2,967 2,589 5,556<br />

West Midlands 3,019 4,246 7,265<br />

Yorkshire and Humber 2,797 8,339 11,136<br />

England - Total 30,320 37,587 67,907 33<br />

Nor<strong>the</strong>rn Ireland - - 1,600 34<br />

Scotland - - 7,800 35<br />

Wales - - 5,300 36<br />

UK - Total - - 82,600<br />

Figure 7 demonstrates that <strong>the</strong> amount of commercial and industrial waste sent <strong>to</strong> landfill in 2002/03 was<br />

lower than that landfilled in 1998/99. There has been a small increase in energy recovery since 1998/99,<br />

but most of <strong>the</strong> reduction in <strong>the</strong> amount of waste which was landfilled from 1998/99 is due <strong>to</strong> <strong>the</strong> increase<br />

in <strong>the</strong> amount which was recycled. Such a development is likely due <strong>to</strong> <strong>the</strong> increases in landfill tax (this<br />

will increase <strong>to</strong> £48/<strong>to</strong>nne <strong>by</strong> 2010/11). As indicated in Figure 7, 42% (about 29 million <strong>to</strong>nnes) of<br />

commercial and industrial waste was recycled in England in 2002/03.<br />

Table 11 Arisings of commercial and industrial waste in England<br />

Year Commercial<br />

Waste<br />

(‘000 <strong>to</strong>nnes)<br />

Industrial Waste<br />

(‘000 <strong>to</strong>nnes)<br />

Total Waste<br />

(‘000 <strong>to</strong>nnes)<br />

2002/03 30,300 28,700 59,000<br />

1998/99 23,700 36,000 59,700<br />

33 Environment Agency 2006 – Strategic Waste Management Assessment 2002/03<br />

34 Commercial & Industrial Waste Arisings Survey 2004/05. Environment & Heritage Service, March 2007<br />

35 Waste Data Digest 8: Key facts and trends. Scottish Environmental Protection Agency, 2008<br />

36 Environment Agency, Wales, http://new.wales.gov.uk/resilience/o<strong>the</strong>r-responders1/env-agy-wales/?lang=en


Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Wastes and Energy<br />

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Figure 7 Management of commercial and industrial waste in England<br />

Table 12 Recycling rates for commercial and industrial waste in English Regions in 2002/03<br />

Region Commercial<br />

Waste<br />

(Wt %)<br />

Industrial<br />

Waste<br />

(Wt %)<br />

Commercial and<br />

Industrial Waste<br />

(Wt %)<br />

East Midlands 37 44 42<br />

East of England 38 45 41<br />

London 41 54 44<br />

North East 34 49 45<br />

North West 32 37 35<br />

South East 30 35 32<br />

South West 35 45 40<br />

West Midlands 40 50 46<br />

Yorkshire and Humber 44 55 52<br />

England – Total 37 47 42<br />

Nor<strong>the</strong>rn Ireland - - 24<br />

Scotland - - -<br />

Wales - - 62*<br />

* recycled / reused<br />

Table 12 shows that:<br />

• Information from Scotland is not available, and that from Wales and Nor<strong>the</strong>rn Ireland is not<br />

split between commercial and industrial.<br />

• The overall recycling rate for industrial waste (47%) is higher than <strong>the</strong> overall recycling rate<br />

(37%) for commercial waste<br />

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• The South East had <strong>the</strong> lowest recycling rates for both commercial waste and industrial<br />

waste<br />

• Yorkshire and Humber had <strong>the</strong> highest recycling rates for both commercial and industrial<br />

waste, and London had <strong>the</strong> second highest recycling rates for both streams.<br />

Most commercial and industrial waste is collected <strong>by</strong> private sec<strong>to</strong>r waste management companies, such<br />

as Sita, Veolia and Viridor. Local authorities have a statu<strong>to</strong>ry obligation <strong>to</strong> collect C&I waste, but <strong>the</strong>y<br />

generally only collect from a proportion of small businesses. Collec<strong>to</strong>rs also provide services <strong>to</strong> collect<br />

recyclable materials, such as paper; this allows businesses <strong>to</strong> demonstrate that <strong>the</strong>ir waste has been<br />

sorted in order <strong>to</strong> comply with <strong>the</strong> requirements of <strong>the</strong> Landfill Directive.<br />

The majority of <strong>the</strong> waste which is not recycled is currently landfilled in landfill sites operated <strong>by</strong> private<br />

sec<strong>to</strong>r companies; however, <strong>the</strong> increases in landfill tax, particularly <strong>the</strong> announcement in <strong>the</strong> 2009<br />

budget that landfill tax will increase <strong>to</strong> £72 per <strong>to</strong>nne <strong>by</strong> 2013 will provide fur<strong>the</strong>r encouragement <strong>to</strong><br />

private sec<strong>to</strong>r companies which are currently developing options for treatment plants which will recover<br />

energy from this waste.<br />

4.2.4 Growth Rates and Future Arisings<br />

The two surveys of arisings of commercial and industrial waste were conducted <strong>by</strong> <strong>the</strong> Environment<br />

Agency in 1998/99 and 2002/03. Table 11 shows that although <strong>the</strong>re was little change in overall arisings,<br />

<strong>the</strong> arisings of commercial waste has increased whilst <strong>the</strong> arisings of industrial waste have decreased.<br />

This is due <strong>to</strong> a shift in employment away from manufacturing industry and <strong>to</strong>wards a service-based<br />

economy.<br />

The lack of yearly data on <strong>the</strong> arisings of commercial and industrial waste makes it difficult <strong>to</strong> predict<br />

future arisings using his<strong>to</strong>ric trends. One projection estimated an average annual growth rate of 2% per<br />

annum for both commercial and industrial waste in <strong>the</strong> South East from 2005 <strong>to</strong> 2020. 37 Ano<strong>the</strong>r<br />

projection has been calculated using <strong>the</strong> Regional Economy-Environment Input-Output (REEIO) model<br />

which was developed <strong>by</strong> Cambridge Econometrics for <strong>the</strong> Environment Agency and <strong>the</strong> Regional<br />

Development Agencies. The model integrates economic growth of 50 commercial and industrial sec<strong>to</strong>rs<br />

with a set of key environmental pressures that include waste arisings. After accounting for <strong>the</strong> impact of<br />

future increases in land tax, <strong>the</strong> model predicted that growth would be approximately 1.3% each year, and<br />

rise <strong>to</strong> 84.5 million <strong>to</strong>nnes <strong>by</strong> 2020, as shown in Table 13. 38 The reduction in <strong>the</strong> proportion of industrial<br />

waste predicted is due <strong>to</strong> both <strong>the</strong> decoupling measures aimed at industrial waste and <strong>the</strong> expected<br />

continued shift <strong>to</strong>wards a service based economy.<br />

Table 13 Predicting C&I Waste arisings with <strong>the</strong> REEIO Model<br />

Commercial and Industrial<br />

Waste<br />

Proportion of Commercial<br />

Waste<br />

Proportion of Industrial<br />

Waste<br />

2002/03<br />

67.5 million<br />

<strong>to</strong>nnes<br />

2019/20<br />

84.5 million<br />

<strong>to</strong>nnes<br />

% growth per<br />

annum<br />

1.3%<br />

42% 53% 2.5%<br />

58% 47% -2.5%<br />

Ano<strong>the</strong>r estimate of future arisings used information from four Regional Assembly Strategy <strong>report</strong>s (East<br />

Midlands, East of England, South East and North West which, between <strong>the</strong>m, are estimated <strong>to</strong> account<br />

37<br />

Model for future waste management capacity needs in <strong>the</strong> South East. Report <strong>by</strong> ERM for South East England Regional Assembly (SEERA),<br />

September 2005.<br />

38<br />

Partial Regula<strong>to</strong>ry Impact Assessment of <strong>the</strong> Review of England’s Waste Strategy. Defra, March 2006.


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for about 40% of overall arisings) <strong>to</strong> estimate that commercial and industrial waste arisings in <strong>the</strong> UK<br />

would increase from 83 million <strong>to</strong>nnes in 2001 <strong>to</strong> 94 million <strong>to</strong>nnes <strong>by</strong> 2020 (based on Environment<br />

Agency data for 1998/99). 39 This is equivalent <strong>to</strong> an average growth rate of 0.8% per annum for <strong>the</strong><br />

overall waste stream, which is lower than <strong>the</strong> estimated average growth rate of 1.4% determined using<br />

<strong>the</strong> REEIO model.<br />

It is likely that commercial and industrial waste arisings will grow at different rates, due <strong>to</strong> continuing shift<br />

<strong>to</strong>wards a service based economy and <strong>the</strong> waste minimisation activities and future increases in landfill<br />

tax. Based on <strong>the</strong> sources above, and industry expert opinion, <strong>the</strong> subsequent predictions used here<br />

have assumed an average growth rate of 1% per annum <strong>to</strong> estimate future arisings of commercial waste,<br />

and 0% per annum for industrial waste as it is unlikely <strong>the</strong>re will be any growth in <strong>the</strong> arisings of industrial<br />

waste.<br />

4.2.5 Conclusion<br />

Commercial and Industrial wastes arise from industry, trade or business activities. Although <strong>the</strong> contents<br />

are similar <strong>to</strong> MSW, <strong>the</strong> relative proportions of material content vary. Disposal of this waste stream is not<br />

<strong>the</strong> responsibility of <strong>the</strong> local authority, and consequently information on arisings and disposal is limited.<br />

However it is clear that this waste stream produces considerably more waste than MSW, <strong>to</strong>talling 82.6<br />

million <strong>to</strong>nnes in 2003.<br />

Information from <strong>the</strong> Environment Agency shows that most of this waste stream is disposed of <strong>to</strong> landfill,<br />

although a significant proportion, much larger than for MSW, is recycled.<br />

4.3 Construction and Demolition (C&D)<br />

4.3.1 Definition<br />

Construction and demolition waste arises largely from <strong>the</strong> demolition of buildings and structures, e.g.<br />

residential, commercial and transport systems.<br />

4.3.2 Composition<br />

Such waste usually contains a high proportion of minerals – demolished brick, concrete, cement and<br />

mortar. Minerals are not biodegradable or combustible. Two options exist for its disposal, removal <strong>to</strong><br />

landfill, or recycling <strong>to</strong> aggregate. A fur<strong>the</strong>r component is a proportion of wood waste, which is <strong>read</strong>ily<br />

combustible or biodegradable over time.<br />

Arisings of wood waste from this waste stream often go unrecorded as only material suitable for<br />

aggregate recycling is recorded. In addition <strong>the</strong> wood waste generated is almost invariably treated in<br />

some way, chemically or painted or o<strong>the</strong>rwise contaminated, which may be classified as hazardous under<br />

present legislation and may have <strong>to</strong> be dealt with in specially designated facilities. For more information<br />

on this subsection, please see <strong>the</strong> later section on wood waste.<br />

4.3.3 Current Arisings<br />

There is little data on <strong>the</strong> amount of C&D waste arisings. This will change in years <strong>to</strong> come as <strong>the</strong> PPC<br />

requirements mean that all sites will have <strong>to</strong> provide data on C&D waste inputs <strong>by</strong> 2012.<br />

39 Quantification of <strong>the</strong> Potential Energy from Residuals (EfR) in <strong>the</strong> UK. Report <strong>by</strong> Oakdene Hollins for The Institution of Civil Engineers and The<br />

Renewable Power Association, March 2005.<br />

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Table 14 shows <strong>the</strong> estimated arisings of C&D waste in <strong>the</strong> UK <strong>by</strong> English Region 40 and <strong>by</strong> Country. The<br />

waste will contain a mixture of mineral waste, soil, wood and plastics.<br />

Table 14 C&D Waste arisings in <strong>the</strong> UK, 2005<br />

Region Construction and<br />

Demolition Waste<br />

(‘000 <strong>to</strong>nnes)<br />

East Midlands 9,821<br />

East of England 11,553<br />

London 8,034<br />

North East 4,815<br />

North West 11,345<br />

South East 14,245<br />

South West 9,482<br />

West Midlands 9,840<br />

Yorkshire and Humber 10,497<br />

England - Total 89,632<br />

Nor<strong>the</strong>rn Ireland 12,200 41<br />

Scotland 11,800 42<br />

Wales 5,000 43<br />

UK – Total 118,600<br />

A breakdown of <strong>the</strong> disposal routes for C&D waste arisings is shown in Table 15. 40 As can be seen a<br />

significant proportion of <strong>the</strong> material is al<strong>read</strong>y recycled, almost all of this will be mineral waste that is<br />

crushed and used as aggregate, displacing virgin aggregate.<br />

Table 15 Regional arisings and management (‘000 <strong>to</strong>nnes) of C&D waste in England<br />

Region Recycled Used on Exempt<br />

Site<br />

Landfilled Total<br />

East Midlands 5,591 733 3,497 9,821<br />

East of England 6,031 1,683 3,839 11,553<br />

London 4,846 2,041 1,147 8,034<br />

North East 1,881 804 2,130 4,815<br />

North West 6,721 1,958 2,666 11,345<br />

South East 6,615 2,513 5,117 14,245<br />

South West 4,030 2,017 3,435 9,482<br />

West Midlands 4,918 2,911 2,011 9,840<br />

Yorkshire and Humber 5,806 7856 3,906 10,497<br />

England –Total 46,439 15,445 27,748 89,632<br />

Nor<strong>the</strong>rn Ireland - - - 12,200<br />

Scotland 50% 44 - - 11,800<br />

Wales 29% 56% 15% 5,000<br />

40 Survey of Arisings and Use of Alternatives <strong>to</strong> Primary Aggregates in England, 2005; Construction, Demolition and Excavation Waste. Report for<br />

Department for Communities and Local Government <strong>by</strong> Capita Symonds Ltd, in association with WRc plc, February 2008<br />

41 Survey on <strong>the</strong> arising and management of construction and demolition waste in Wales in 2005-06. Environment Agency, Wales.<br />

42 Waste Data Digest 8: Key facts and trends. Scottish Environmental Protection Agency, 2008<br />

43 Construction and demolition waste survey. Environment and Heritage Service (EHS), 2004<br />

44 Internal AEA estimate from AEA expert.


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4.3.4 Future Arisings<br />

Three surveys of arisings of construction and demolition (C&D) waste in England have been conducted<br />

since <strong>the</strong> year 2000. The findings are summarised in Table 16.<br />

Table 16: Estimated arisings (million <strong>to</strong>nnes) of construction and demolition waste in England<br />

2001 2003 2005<br />

Recycled aggregate and soil 43.3 45.4 46.4<br />

Landfilled at landfill sites 23.2 29.1 27.8<br />

Used at Registered Exempt sites 22.4 16.4 15.4<br />

Total 88.9 90.9 89.6<br />

A comparison of <strong>the</strong> estimates for 2001, 2003 and 2005 shows that <strong>the</strong> <strong>to</strong>tal arisings of C&D waste are<br />

similar. The amount of C&D waste which is recycled has increased from 49% in 2001 <strong>to</strong> 52% in 2005,<br />

but this increase is not statistically significant. The amount of material used on Registered Exempt sites<br />

has fallen <strong>by</strong> 7 million <strong>to</strong>nnes since 2001, and <strong>the</strong> amount of waste landfilled at landfill sites has increased<br />

<strong>by</strong> 4.5 million <strong>to</strong>nnes since 2001. 45<br />

The data in Table 16 show that <strong>the</strong>re has been little growth in C&D arisings since 2001. Ano<strong>the</strong>r<br />

projection estimated an average annual growth rate of 0% per annum for construction and demolition<br />

waste in <strong>the</strong> South East from 2005 <strong>to</strong> 2020. Consequently, an average growth rate of 0% per annum has<br />

been used <strong>to</strong> estimate future arisings of this stream.<br />

4.3.5 Conclusions<br />

Construction and demolition waste is <strong>the</strong> largest of <strong>the</strong> three controlled waste streams, with <strong>the</strong> UK<br />

producing an estimated 118.6 million <strong>to</strong>nnes in 2005.<br />

The majority of <strong>the</strong> waste is mineral, bricks, concrete, etc, and as such can be crushed and used <strong>to</strong><br />

displace virgin aggregate. A significant proportion will be soil, which can be reused as soil or also used <strong>to</strong><br />

displace virgin aggregate. However this waste stream will also contain a proportion of wood and plastics<br />

that could be used for energy production. Although it is possible <strong>to</strong> recycle or recover many of <strong>the</strong>se<br />

materials, in practice this is not often done due <strong>to</strong> <strong>the</strong> level of contamination and <strong>the</strong> diverse nature of <strong>the</strong><br />

sources.<br />

Data on arisings of this waste stream is currently very limited, however this situation should improve in <strong>the</strong><br />

near future with <strong>the</strong> <strong>report</strong>ing requirements of <strong>the</strong> PPC becoming widesp<strong>read</strong>.<br />

4.3.6 Predicted Future Arisings for MSW, C&I and C&D<br />

Table 17 gives <strong>the</strong> summary arisings of Municipal Solid Waste, Commercial and Industrial Waste and<br />

Construction and Demolition Wastes <strong>by</strong> country in <strong>the</strong> UK. For all countries in <strong>the</strong> UK significantly more<br />

construction and demolition waste is produced than any o<strong>the</strong>r waste stream, while MSW waste arisings is<br />

<strong>the</strong> smallest waste stream of <strong>the</strong> three controlled categories.<br />

45 Sites exempted under <strong>the</strong> terms of Paragraphs 9A(1) and/or 19A(2) of Schedule 3 <strong>to</strong> <strong>the</strong> Waste Management Licensing Regulations 1994 as<br />

amended <strong>by</strong> <strong>the</strong> Waste Management Licensing (England and Wales) (Amendment and Related Provisions) (No.3) Regulations 2005 (SI<br />

No.2005/1728); ‘Paragraph 9A(1) sites’ are registered exempt sites where exemption holders are permitted <strong>to</strong> sp<strong>read</strong> up <strong>to</strong> 20,000 m³/ha of certain<br />

specified waste materials including soil, rock, ash, some sludges, dredgings or C&D waste for land reclamation /res<strong>to</strong>ration / improvement purposes or<br />

agricultural improvement. Paragraph 19A(2) sites are registered exempt sites where exemption holders are permitted <strong>to</strong> use certain specified waste<br />

materials including C&D waste, excavation waste, ash, clinker, rock, wood or gypsum in connection with recreational or infrastructure projects,<br />

excluding land reclamation.<br />

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Table 17 Waste arisings (‘000,000 <strong>to</strong>nnes) in <strong>the</strong> UK<br />

Year England Wales Scotland 46 Nor<strong>the</strong>rn<br />

Ireland<br />

Total<br />

MSW 28.5 47 1.8 48 3.0 1.1 49 34.4<br />

C&I waste 67.9 50 5.3 51 7.8 1.6 52 82.6<br />

C&D waste 89.6 53 12.2 54 11.8 5.0 55 118.6<br />

Total 186.0 19.3 22.6 7.7 235.6<br />

Using <strong>the</strong> prediction figures discussed in preceding sections, Table 18 shows <strong>the</strong> estimated arisings of<br />

municipal solid waste, commercial waste, industrial waste and construction and demolition waste in 2010,<br />

2015 and 2020. These have been produced using <strong>the</strong> <strong>to</strong>nnage arisings shown in Table 18 (assuming a<br />

baseline year of 2005) and <strong>the</strong> average growth rates for each of <strong>the</strong>se waste streams determined in this<br />

section of <strong>the</strong> <strong>report</strong>: MSW growth at 0.75%, Commercial waste at 1%, Industrial waste at 0% and C&I<br />

waste at 0%. The <strong>to</strong>tal arisings of <strong>the</strong>se waste streams in <strong>the</strong> UK is estimated <strong>to</strong> rise from 236 million<br />

<strong>to</strong>nnes in 2005 <strong>to</strong> 246 million <strong>to</strong>nnes in 2020 due <strong>to</strong> <strong>the</strong> growth in <strong>the</strong> arisings of both municipal solid<br />

waste and commercial waste.<br />

Table 18: Estimated future UK waste arisings (‘000,000 <strong>to</strong>nnes)<br />

Year<br />

2005 2010 2015 2020<br />

Municipal Solid Waste 34 36 37 38<br />

Commercial Waste 37 39 41 43<br />

Industrial Waste 45 45 45 45<br />

Construction and Demolition Waste 119 119 119 119<br />

Total 236 239 242 246<br />

The projections of future arisings shown in Table 18 have not considered <strong>the</strong> potential impacts <strong>the</strong> current<br />

economic situation may have on future waste arisings. The arisings of some waste streams could reduce<br />

over <strong>the</strong> next few years due <strong>to</strong> <strong>the</strong> following fac<strong>to</strong>rs:<br />

• Municipal solid waste - Reduction in MSW growth rate due <strong>to</strong> fewer houses being built,<br />

<strong>to</strong>ge<strong>the</strong>r with continuing waste reduction activities and less spending per household<br />

• Commercial waste - Reduction in C&I growth rate, and this could become negative as <strong>the</strong><br />

number of commercial businesses reduces (<strong>the</strong> financial situation is anticipated <strong>to</strong> have more<br />

impact on <strong>the</strong> commercial sec<strong>to</strong>r than <strong>the</strong> industrial sec<strong>to</strong>r due <strong>to</strong> <strong>the</strong> reduction in <strong>the</strong> number<br />

of jobs in <strong>the</strong> retail and banking sec<strong>to</strong>rs).<br />

• Construction and demolition waste – reduction in number of buildings being demolished <strong>to</strong><br />

start new construction/development projects.<br />

Waste arisings for all of <strong>the</strong>se streams could fall over <strong>the</strong> next few years, but should begin <strong>to</strong> increase<br />

again as economic recovery occurs.<br />

46<br />

Waste Data Digest 8: Key facts and trends. Scottish Environmental Protection Agency, 2008<br />

47<br />

Defra - http://www.defra.gov.uk/environment/statistics/wastats/bulletin08.htm<br />

48<br />

Municipal Waste Management Report for Wales, 2007-08. Statistics for Wales, Oc<strong>to</strong>ber 2008<br />

49<br />

Municipal Waste Management Nor<strong>the</strong>rn Ireland 2005/06 Summary Report, December 2006<br />

50<br />

Environment Agency 2006 – Strategic Waste Management Assessment 2002/03<br />

51<br />

Environment Agency Wales, http://www.environment-agency.gov.uk/aboutus/organisation/35675.aspx<br />

52<br />

Commercial & Industrial Waste Arisings Survey 2004/05. Environment & Heritage Service, March 2007<br />

53<br />

Survey of Arisings and Use of Alternatives <strong>to</strong> Primary Aggregates in England, 2005; Construction, Demolition and Excavation Waste. Report for<br />

Department for Communities and Local Government <strong>by</strong> Capita Symonds Ltd, in association with WRc plc, February 2008<br />

54<br />

Survey on <strong>the</strong> arising and management of construction and demolition waste in<br />

Wales in 2005-06. Environment agency Wales<br />

55<br />

Construction and demolition waste survey. Environment and Heritage Service (EHS), 2004


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4.4 Bio-solids<br />

4.4.1 Definition<br />

Sewage is <strong>the</strong> wastewater collected from homes, industrial premises, offices and commercial premises<br />

and carried through <strong>the</strong> sewerage system <strong>to</strong> a wastewater treatment works. The residual component,<br />

once <strong>the</strong> clean water has been discharged back in<strong>to</strong> waterways, is <strong>the</strong> bio-solids, (also known as sewage<br />

sludge).<br />

4.4.2 Composition<br />

Sewage is mostly water, including drainage waster from car parks, roads and o<strong>the</strong>r areas of concrete or<br />

tarmac. Sewage contains about 3% solid waste, which reduces <strong>to</strong> under 1% once it has been screened<br />

(i.e. all <strong>the</strong> grit, fats, soil, sanitary and contraceptive waste are removed) at <strong>the</strong> sewage treatment works.<br />

Human waste forms a relatively small proportion of <strong>the</strong> <strong>to</strong>tal volume of sewage. 56<br />

Sewage goes through several treatment processes at a waste-water works before it is returned <strong>to</strong> river or<br />

<strong>the</strong> sea in a condition such that no significant pollution or environmental degradation occurs. The main<br />

<strong>by</strong>-product of any sewage treatment works is bio-solids.<br />

The treatment and disposal of bio-solids is subject <strong>to</strong> various regulations. The two most relevant pieces<br />

are <strong>the</strong> Urban Waste Water Treatment Directive (UWWT Directive), and <strong>the</strong> Sludge (use in agriculture)<br />

Regulations 1989. The Directive details controls for <strong>the</strong> treatment and disposal of bio-solids, and was <strong>the</strong><br />

legislation that banned disposal at sea, <strong>the</strong> option that was widely practiced, before 1998. The Sludge<br />

Regulations control <strong>the</strong> sp<strong>read</strong>ing of this material on land. In addition <strong>the</strong>re is <strong>the</strong> Safe Sludge Matrix<br />

from 2001, a voluntary agreement that ensures bio-solids is applied only <strong>to</strong> certain crops and plants. 57<br />

Sludge from secondary treatment and Anaerobic Digestion (AD) is still very high in water content (>90%<br />

in most cases) and is <strong>the</strong>refore often subjected <strong>to</strong> fur<strong>the</strong>r dewatering before final disposal. The<br />

dewatering decreases <strong>the</strong> volume of sludge and hence <strong>the</strong> cost of transport considerably. Such<br />

processes include centrifugation (which can increase <strong>the</strong> solid content <strong>to</strong> 24-30%, producing a sludge<br />

cake); belt/filter pressing (which can decrease <strong>the</strong> volume <strong>to</strong> 10-20% of <strong>the</strong> un-pressed sludge); and<br />

<strong>the</strong>rmal drying (which increases <strong>the</strong> sludge solids <strong>to</strong> 80-95% and results in sludge in <strong>the</strong> form of dust or<br />

pellets). These processes are used in particular in larger sewage treatment works where <strong>the</strong> cost of<br />

disposing of large volumes of high liquid content sludge is prohibitive.<br />

4.4.3 Current Arisings<br />

Information on <strong>the</strong> quantity of UK bio-solids arising, and <strong>the</strong> methods of disposal are release <strong>by</strong> Defra, up<br />

<strong>to</strong> 2005. 58 Since 1989/90 <strong>the</strong> level of arisings has increased <strong>to</strong> 1.4 million <strong>to</strong>nnes as a result of <strong>the</strong><br />

UWWT Directive and hence wastewater requiring more treatment. 59<br />

The UK produces some 11 billion litres of waste water every day, which goes <strong>to</strong> around 9,000 sewage<br />

treatment works around <strong>the</strong> country before <strong>the</strong> treated effluent is discharged <strong>to</strong> inland waters, estuaries<br />

and <strong>the</strong> sea. 56<br />

56<br />

Sewage Treatment in <strong>the</strong> UK, Defra 2002, http://www.defra.gov.uk/environment/water/quality/uwwtd/<strong>report</strong>02/pdf/uwwt<strong>report</strong>2.pdf<br />

57<br />

Sewage Sludge, Defra, http://www.defra.gov.uk/environment/statistics/waste/wrsewage.htm<br />

58<br />

e-Digest Statistics, Defra<br />

59<br />

Council Directive 91/271/EEC Urban Waste Water Treatment, 1991, http://eur-lex.europa.eu/LexUriServ/site/en/consleg/1991/L/01991L0271-<br />

20031120-en.pdf<br />

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Table 19 Bio-solids Arising in <strong>the</strong> UK (‘000 dry <strong>to</strong>nnes) 57<br />

Region 2000 2001 2002 2003 2004 2005<br />

England and Wales 941 1137 1249 1280 1221 1369<br />

Scotland 97 N/A 113 113 113 140<br />

Nor<strong>the</strong>rn Ireland 34 N/A 28 29 34 -<br />

Total 1,072 - 1,390 1,422 1,368 -<br />

Table 20 shows <strong>the</strong> sewage waste arising <strong>by</strong> UK region in dry weight. 60 The bio-solids arising <strong>by</strong> English<br />

region is difficult <strong>to</strong> calculate since <strong>the</strong> water companies who produce it operate across regions that do<br />

not correspond <strong>to</strong> <strong>the</strong> divisions of <strong>the</strong> development agencies in England. Therefore <strong>the</strong> bio-solid arisings<br />

have been <strong>report</strong>ed according <strong>to</strong> <strong>the</strong> water company regions.<br />

Table 20 Estimated bio-solids arising <strong>by</strong> English and Welsh water companies in 2000 61<br />

Region Dry Solids<br />

(‘000 <strong>to</strong>nnes)<br />

United Utilities Water 258<br />

Welsh Water 86<br />

Yorkshire Water 154<br />

Anglican Water 180<br />

Wessex Water 82<br />

Southwest Water 56<br />

Northumbria Water 65<br />

Severn Trent Water 262<br />

Thames Water 325<br />

Sou<strong>the</strong>rn Water 136<br />

Total 1,605<br />

60 Most figures relating <strong>to</strong> sewage sludge (biosolids) are quoted in terms of dry solids. This is due <strong>to</strong> <strong>the</strong> variable water contents of <strong>the</strong> sludges.<br />

Quoting data as dry solids allows comparison between sludges. However, it must be remembered that water is always present in biosolids or sewage<br />

sludge. If sewage sludge is 10% dry solids, 90% of <strong>the</strong> volume will be water and this will also represent a considerable weight.<br />

61 Ofwat 2004, Utilities Summary of Outputs, http://www.ofwat.gov.uk


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Figure 8 Geographical representation of <strong>the</strong> operating areas of <strong>the</strong> water companies in England and Wales. 62<br />

Ano<strong>the</strong>r source of information are <strong>the</strong> individual water companies, but <strong>the</strong> level of information <strong>report</strong>ed<br />

varies company <strong>by</strong> company.<br />

4.4.4 Current Disposal Options<br />

There are a number of options available for <strong>the</strong> disposal of bio-solids, each of which are used <strong>to</strong> a varying<br />

degree, as illustrated in Figure 9. Although bio-solids are predominantly disposed of <strong>to</strong> land currently,<br />

this situation may change as discussed below.<br />

Application <strong>to</strong> land<br />

Bio-solids are predominately recycled <strong>to</strong> land, acting as a fertiliser. 63 This is a flexible solution for <strong>the</strong><br />

wastewater opera<strong>to</strong>rs as agricultural sites can be changed or sourced relatively quickly in order <strong>to</strong> meet<br />

changing operational needs.<br />

Application of bio-solids <strong>to</strong> land that is being reclaimed is also practiced, as it can help <strong>to</strong> res<strong>to</strong>re soil<br />

nutrients and stability. Bio-solids can be incorporated in<strong>to</strong> spoil <strong>to</strong> increase <strong>the</strong> stability, creating a soil<br />

64,65, 66<br />

that contains nutrients enough <strong>to</strong> support plant growth.<br />

62 Con29DW, Drainage and Water Enquiry, http://www.drainageandwater.co.uk<br />

63 Thames Water 25 year Sludge Strategy, 2008, http://www.thameswater.co.uk/cps/rde/xbcr/SID-54091C65-CAD380F4/corp/sludge-strategy.pdf<br />

64 The Beneficial Use of Sewage Sludge in Land Reclamation, 2004, Water UK,<br />

http://www.water.org.uk/static/files_archive/2Sludge_for_Land_res<strong>to</strong>ration_briefing_Notes_v2_march_15.doc<br />

65 Beneficial Effects of Biosolids on Soil Quality and Fertility ADAS Research review 2001-2002 – Environment ADAS Ltd. www.adas.co.uk<br />

66 Wastewater treatment and use in agriculture - FAO irrigation and drainage paper 47 M.B. Pescod 1992<br />

Food and Agriculture Organisation of <strong>the</strong> United Nations www.fao.org/<br />

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However disposal <strong>to</strong> land may reduce in coming years as legislative and practical constraints limit this<br />

route. 67 The available land bank may reduce due <strong>to</strong> a reluctance <strong>to</strong> have food products grown on land<br />

treated with this waste, although <strong>the</strong> growth of energy crops would provide a (small) mitigating land<br />

availability. 67 The impact of <strong>the</strong> Nitrates Directive (Nitrate Vulnerable Zones Regulations) may be a<br />

reduction in <strong>the</strong> volume of sludge that can be applied in certain areas.<br />

Landfill<br />

A small amount of sludge is disposed of <strong>to</strong> landfill, which is largely used only as a fall back option as it<br />

can be used at very short notice. 56 This route is not sustainable in <strong>the</strong> longer term and <strong>the</strong> costs<br />

associated with it are increasing as landfill tax levels go up and void space is reduced. In addition, due <strong>to</strong><br />

<strong>the</strong> high water content of bio-solids only a limited number of sites are willing <strong>to</strong> accept it due <strong>to</strong> <strong>the</strong><br />

potential impact on <strong>the</strong> landfill sites’ leachate management programme.<br />

Incineration<br />

Incineration is <strong>the</strong> second largest disposal route, generally used <strong>by</strong> <strong>the</strong> larger treatment works. 56 The<br />

heat generated is often used on site <strong>to</strong> meet <strong>the</strong> heating needs of <strong>the</strong> process, i.e. <strong>to</strong> dry <strong>the</strong> bio-solids,<br />

and generate electricity. Several stages of cleaning of <strong>the</strong> flue gases are incorporated within <strong>the</strong> process<br />

<strong>to</strong> ensure <strong>the</strong>y meet EU emission limits set <strong>by</strong> <strong>the</strong> Waste Incineration, <strong>the</strong> Integrated Pollution Prevention<br />

and Control (IPPC) and <strong>the</strong> Landfill Directives. 68 The calorific value of bio-solids is dependent on <strong>the</strong> type<br />

of material, its water content (<strong>the</strong> degree of dewatering) and <strong>the</strong> concentration of organic matter present,<br />

solids content, calorific values and biomass contents vary according <strong>to</strong> <strong>the</strong> type of treatment.<br />

Incineration is a relatively expensive option, so it is only of interest in areas where alternative disposal<br />

methods are not available or <strong>the</strong> cost of transportation is prohibitive.<br />

Incineration of bio-solids involves burning <strong>the</strong> sludge at 600-900°C <strong>to</strong> destroy <strong>the</strong> organic content, leaving<br />

a residue of mineral ash for final disposal (usually <strong>to</strong> landfill or controlled waste re-use such as land<br />

reclamation). The net calorific value of dried bio-solids, i.e. its energy content after deducting <strong>the</strong> heat<br />

required <strong>to</strong> evaporate <strong>the</strong> remaining water is around 23MJ/kg of volatile solids. 69<br />

Co-incineration<br />

The bio-solids, ei<strong>the</strong>r as dewatered cake, but generally as dried pellets, can be burnt in adapted (WID<br />

compliant) plants, often co-fired with coal. It is possible <strong>to</strong> burn bio-solids with municipal waste, however,<br />

<strong>the</strong> burner design system must be capable of handling both fuels.<br />

67 Thames Water 25 year Sludge Strategy, 2008, http://www.thameswater.co.uk/cps/rde/xbcr/SID-54091C65-CAD380F4/corp/sludge-strategy.pdf<br />

68 Waste Incineration Directive http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2000:332:0091:0111:EN:PDF, Integrated Pollution<br />

Prevention and Control, original legislation, http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31996L0061:EN:HTML, Landfill Directive<br />

http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:1999:182:0001:0019:EN:PDF<br />

69 Sewage Sludge Disposal: operational and environmental issues, Bruce A.M. and Evans, T.D., Foundation of Water Research, 2002.


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20%<br />

1%<br />

11%<br />

4.4.5 Future Arisings<br />

4%<br />

64%<br />

Farmland<br />

Landfill<br />

Incineration<br />

Land reclamation/res<strong>to</strong>ration<br />

O<strong>the</strong>r<br />

Figure 9 Disposal of bio-solids in 2004 70<br />

The volumes of bio-solids created are increasing, through increased population, and through increased<br />

levels of treatment of municipal sewage, and at times dedicated industrial effluent treatment plants run <strong>by</strong><br />

<strong>the</strong> water companies. The increase is also in part due <strong>to</strong> <strong>the</strong> increased levels of sewage treatment<br />

required through tightened Regulations. 71<br />

In 2004-5 1.72 Mt of dry bio-solids were produced. Work carried out internally in AEA has estimated that<br />

this will increase <strong>to</strong> 2.5 Mt <strong>by</strong> 2030 due <strong>to</strong> changes in industry practice brought about <strong>by</strong> legislation<br />

relating <strong>to</strong> requirements for improved treatment practices.<br />

One water company, Thames Water, have estimated <strong>the</strong> future arising of bio-solids until 2021, and<br />

extrapolated fur<strong>the</strong>r <strong>to</strong> 2035. 72 The prediction is for a steady increase in <strong>the</strong>ir production of bio-solids year<br />

on year.<br />

The volume of bio-solids available for conversion in<strong>to</strong> fuels and energy is likely <strong>to</strong> increase in future years,<br />

due <strong>to</strong> increasing populations in some areas, and decreasing opportunities <strong>to</strong> utilise traditional disposal<br />

methods in all areas of <strong>the</strong> UK.<br />

70<br />

Sewage sludge arisings and management 1986/97 – 2005, Defra.<br />

71 th<br />

Determining sludge production from wastewater treatment, Clode, K., Khraisheh, M., Ballinger, D., 2008, 13 European Biosolids and Organic<br />

Resources Conference and Workshop.<br />

72<br />

Thames Water 25 year Sludge Strategy, 2008, http://www.thameswater.co.uk/cps/rde/xbcr/SID-54091C65-CAD380F4/corp/sludge-strategy.pdf,<br />

based on Local Authority growth projections, taking in consideration such variables as new development and housing density until 2021, and <strong>the</strong>n<br />

linearly extrapolated <strong>to</strong> provide best future estimates <strong>to</strong> 2035, with no specific allowance been made for additional sludge arising from currently<br />

unknown changes in legislation treatment standards, cus<strong>to</strong>mer behaviour or o<strong>the</strong>r fac<strong>to</strong>rs, such as impact of Local Authority waste strategies.<br />

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4.4.6 Conclusions<br />

Bio-solids are <strong>the</strong> product of <strong>the</strong> waste-water treatment works. Even after several stages of treatment it is<br />

still largely comprised of water.<br />

Increasing waste-water legislation, and increasing population in <strong>the</strong> UK, results in increased volumes of<br />

bio-solids: up <strong>to</strong> 1,368,000 dry <strong>to</strong>nnes in 2004. Much of this waste is ultimately recycled <strong>to</strong> land as a<br />

fertiliser but this use will be restricted in <strong>the</strong> future due <strong>to</strong> tighter regulation of nitrogen application <strong>to</strong><br />

agricultural land in some sensitive areas.<br />

4.5 Agricultural Residues and Waste<br />

4.5.1 Definition<br />

Agriculture produces a variety of residues, but only limited waste. The distinction is made between<br />

controlled wastes and uncontrolled resides. Wastes are items such as chemicals, plastic, containers and<br />

o<strong>the</strong>r packaging, and controls on this waste stream were introduced in May 2006. Agricultural waste is<br />

<strong>to</strong>o heterogeneous and widely dispersed <strong>to</strong> provide an easy feeds<strong>to</strong>ck. Agricultural residues include<br />

animal manures and slurry, and crop straws and husks, which rarely leave <strong>the</strong> confines of a farm, and<br />

<strong>the</strong>refore are not recorded. Such residues are generally homogeneous which makes <strong>the</strong>m a more<br />

realistic potential feeds<strong>to</strong>ck. Manure and slurry sp<strong>read</strong> at <strong>the</strong> place of production, for <strong>the</strong> benefit of<br />

agriculture, is not considered <strong>to</strong> be waste under <strong>the</strong> current regulations. In 2005 <strong>the</strong> European<br />

Commission judged that lives<strong>to</strong>ck effluent would fall outside <strong>the</strong> classification of waste if it were<br />

subsequently used as a soil fertiliser. 73 The application of <strong>the</strong>se residues <strong>to</strong> land is a traditional practice<br />

that helps <strong>to</strong> replenish nutrients, and reduces <strong>the</strong> amount of artificial fertiliser that would o<strong>the</strong>rwise be<br />

applied.<br />

However, agricultural residues can lead <strong>to</strong> air, land and water pollution if not managed properly. Farm<br />

slurries are many times more polluting than human sewage and when not correctly managed can cause<br />

serious environmental damage, particularly <strong>by</strong> adulterating watercourses and producing odours. Heavy<br />

fines can be imposed on farmers for pollution of watercourses with animal slurries. In addition traditional<br />

disposal methods are increasingly leading <strong>to</strong> problems. Defra now advise against general sp<strong>read</strong>ing of<br />

slurry for example, due <strong>to</strong> concerns about <strong>the</strong> loss of ammonia <strong>to</strong> <strong>the</strong> air. Such concerns are a major<br />

driver <strong>to</strong> re-evaluate <strong>the</strong> methods for treating and disposing of farm wastes and residues.<br />

4.5.2 Composition<br />

Agricultural residues can be subdivided in<strong>to</strong> two categories:<br />

• Wet residues are animal slurries and farmyard manures that have a solid content of under 15%.<br />

• Dry residues include straw, husks and processing waste, as well as poultry litter from poultry<br />

reared for meat.<br />

73 European Court judgment, Case C-416/02 European Commission v Kingdom of Spain,<br />

http://europa.eu.int/smartapi/cgi/sga_doc?smartapi!celexplus!prod!CELEXnumdoc&lg=en&numdoc=62002J0416.


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Wet Agricultural Residues<br />

Wet farm residues are characterised <strong>by</strong> <strong>the</strong> lives<strong>to</strong>ck and waste reception and collection methods, which<br />

are largely consistent throughout <strong>the</strong> UK.<br />

Farm slurries are derived from three major sources: cattle, pigs and egg-laying poultry. In addition <strong>to</strong><br />

animal effluent, o<strong>the</strong>r sources of wet farm residues include parlour/dairy/vegetable washings, waste milk,<br />

bio-solids and silage effluent. Currently <strong>the</strong> majority of <strong>the</strong>se residues are recycled <strong>to</strong> land.<br />

Slurry accumulates and must be managed wherever animals are housed, a particular issue during <strong>the</strong><br />

over wintering of animals indoors, or in milking parlours and egg production facilities. Slurry handling<br />

systems usually consist of floor scrapers <strong>to</strong> move <strong>the</strong> slurry in<strong>to</strong> channels from which it is pumped in<strong>to</strong> a<br />

s<strong>to</strong>rage tank or lagoon. Sophisticated systems also use a separa<strong>to</strong>r <strong>to</strong> remove <strong>the</strong> fibrous portion of <strong>the</strong><br />

slurry for sale as a compost base, while <strong>the</strong> more basic systems allow natural settlement. The type of<br />

system used is relevant because it can dramatically affect <strong>the</strong> level of solids collected.<br />

Lives<strong>to</strong>ck Numbers and Residue Arisings<br />

The key aspect <strong>to</strong> utilising lives<strong>to</strong>ck slurry and manures is that <strong>the</strong>y must be collectable, and in practice<br />

this limits <strong>the</strong> utilisation of <strong>the</strong> residue <strong>to</strong> when <strong>the</strong> animals are housed. When <strong>the</strong> animals are on pasture<br />

fields, especially during <strong>the</strong> summer months, <strong>the</strong> manure is dropped on<strong>to</strong> <strong>the</strong> field and is unavailable for<br />

collection. In addition <strong>the</strong> type of bedding material used will affect <strong>the</strong> characteristics of <strong>the</strong> manure or<br />

slurry produced. Common bedding materials include straw, wood chips, sand, or compost. 74<br />

Fur<strong>the</strong>r, <strong>the</strong> collectable proportion of wet residues is al<strong>read</strong>y widely used as a fertiliser, as discussed<br />

above, and so availability is also an issue.<br />

The UK estimates of lives<strong>to</strong>ck residues vary considerably, as <strong>the</strong>se residues are rarely collected or<br />

regulated for disposal <strong>by</strong> third parties. They are estimated from <strong>the</strong> number and distribution of lives<strong>to</strong>ck,<br />

and <strong>the</strong>se will change as lives<strong>to</strong>ck farming changes each year. The most recent Environment Agency<br />

figure for agricultural wet waste was 45 million <strong>to</strong>nnes, while work performed <strong>by</strong> AEA generated <strong>the</strong><br />

considerably higher figure of 67-88 million <strong>to</strong>nnes produced annually.<br />

The diagram below illustrates <strong>the</strong> quantity and type of residues from typical UK lives<strong>to</strong>ck, and <strong>the</strong><br />

proportion each produces of slurry and farmyard manure (FYM).<br />

Quantity ('000 te)<br />

40000<br />

35000<br />

30000<br />

25000<br />

20000<br />

15000<br />

10000<br />

5000<br />

0<br />

15,124<br />

18,142<br />

34,423<br />

4,481<br />

4,901<br />

2,467<br />

FYM<br />

Slurry<br />

4,276 4,036<br />

Dairy Beef Pigs Poultry Sheep<br />

Figure 10 Slurry and FYM in UK, <strong>by</strong> main lives<strong>to</strong>ck categories<br />

74 Dairy Waste Anaerobic Digestion Handbook, <strong>by</strong> Dennis A. Burke P.E., June 2001 http://www.mrec.org/pubs/Dairy%20Waste%20Handbook.pdf<br />

UK<br />

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Although <strong>the</strong>re is considerable variation in <strong>the</strong> residue output of lives<strong>to</strong>ck, as it is species dependent, age<br />

and type of animal dependent, and residue collection system dependent, some generalisations can be<br />

made:<br />

• Where cows are housed, usually for part of <strong>the</strong> winter, and for regular portions of each day if it is<br />

a dairy herd, <strong>the</strong> slurry is usually collected mixed with straw, using a scraper system. Slurry is<br />

collected on around 18% of beef cattle farms, and 66% of dairy cattle farms. The addition of<br />

straw will alter <strong>the</strong> <strong>to</strong>tal solid composition, as will <strong>the</strong> type of housing system in use. Rinsing of<br />

<strong>the</strong> area is not common, so dilution of <strong>the</strong> slurry with water is minimal. 75<br />

• Most pigs are housed for <strong>the</strong> majority of <strong>the</strong>ir lives, often 100%, making collection of <strong>the</strong>ir<br />

residues viable. However variation in <strong>the</strong> types of housing, and methods of farming mean that<br />

<strong>the</strong>re are large variations of <strong>to</strong>tal solids and organic dry matter. Larger pig farms usually collect<br />

<strong>the</strong> waste as a liquid slurry, at a high dilution. O<strong>the</strong>r methods include <strong>the</strong> use of a scraper system<br />

which produces a higher dry content. 75<br />

• Egg laying poultry do not use bedding, and <strong>the</strong>refore <strong>the</strong>ir residues are quite wet and count as<br />

wet residue. In contract poultry raised for meat will use bedding, often sawdust and wood<br />

shavings, and considerable time elapses before <strong>the</strong> residue is collected, permitting significant<br />

drying <strong>to</strong> occur. Thus <strong>the</strong>se residues are considered <strong>to</strong> be dry residues.<br />

• Sheep are largely un-housed, so it is not possible <strong>to</strong> collect <strong>the</strong>ir residues. For this reason <strong>the</strong>y<br />

have not been considered any fur<strong>the</strong>r in this <strong>report</strong>.<br />

Lives<strong>to</strong>ck can be grouped according <strong>to</strong> <strong>the</strong> category of animal and <strong>the</strong> type of collection system that is<br />

likely <strong>to</strong> be used. Such a scaling system has been used previously <strong>to</strong> estimate <strong>the</strong> potential methane<br />

yield of agricultural residues for Defra. 76 These scaling fac<strong>to</strong>rs can be applied <strong>to</strong> <strong>the</strong> <strong>to</strong>tal number of<br />

lives<strong>to</strong>ck, <strong>to</strong> begin <strong>to</strong> estimate <strong>the</strong> regional arisings of residues.<br />

The <strong>to</strong>tal current lives<strong>to</strong>ck numbers are detailed in Table 21, and have been taken from <strong>the</strong> Farm Surveys<br />

of England, Scotland, Wales and Nor<strong>the</strong>rn Ireland. Fur<strong>the</strong>r breakdown of <strong>the</strong> numbers can be found in<br />

Appendix 1, where more detailed categorisation has been used. 77<br />

Table 21 Lives<strong>to</strong>ck numbers for <strong>the</strong> UK, on a regional basis.<br />

Cattle Pigs Total Fowls<br />

Region<br />

(‘000 head) (‘000 head) (‘000 head)<br />

East Midlands 519 418 24,178<br />

East of England 220 1,066 25,312<br />

North East 286 85 2,428<br />

North West 965 160 8,263<br />

South East inc. London 461 259 9,867<br />

South West 1,804 480 18,316<br />

West Midlands 760 235 16,602<br />

Yorkshire and Humber 583 1,239 14,408<br />

England - Total 5,598 3,943 119,374<br />

Nor<strong>the</strong>rn Ireland 1,623 402 16,322<br />

Scotland 1,897 457 8,308<br />

Wales 1,323 25 5,836<br />

UK - Total 10,440 4,828 150, 000<br />

75 Feeds<strong>to</strong>cks for Anaerobic Digestion, AD-NETT Report 2000.<br />

76 Assessment of Methane Management and Recovery Options for Lives<strong>to</strong>ck Manures and Slurries, 2005, AEA for Defra. Figures calculated from<br />

English data. Applied uniformly here <strong>to</strong> England, Scotland, Wales and Nor<strong>the</strong>rn Ireland.<br />

77 June Survey of Agriculture and Horticulture (Land use, lives<strong>to</strong>ck and labour on agricultural holdings at 1 June 2008) England – Final Results, Defra,<br />

Published 20 November 2008. Welsh Agricultural Statistics 2007, http://wales.gov.uk/<strong>to</strong>pics/statistics/publications/was2007/?lang=en, 2008 June<br />

Agricultural and Horticultural Census for Scotland, http://www.scotland.gov.uk/Publications/2008/06/19154131/1 , The Agricultural Census in Nor<strong>the</strong>rn<br />

Ireland, 2008 http://www.dardni.gov.uk/da1_09_25820__08.09.160_agricultural_census_in_ni_-_results_for_june_2008_amended.pdf.pdf


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Lives<strong>to</strong>ck manure is principally composed of organic matter that if s<strong>to</strong>red in an anaerobic environment will<br />

decompose <strong>to</strong> produce methane. The level of methane production depends on <strong>the</strong> quantity and quality of<br />

<strong>the</strong> manure, and on <strong>the</strong> environment, i.e. <strong>the</strong> proportion that decomposes anaerobically.<br />

Table 22 details <strong>the</strong> manure generation characteristics of <strong>the</strong> various categories of lives<strong>to</strong>ck as discussed<br />

above. The amount of Volatile Solids is closely related <strong>to</strong> <strong>the</strong> quantity of dry matter produced in <strong>the</strong><br />

manure.<br />

Table 22 Animal manure generation characteristics 76<br />

Animal Proportion of <strong>the</strong><br />

year housed<br />

Proportion of<br />

waste collected<br />

as slurry<br />

Volatile Solids<br />

kg/head/day<br />

Dairy cow 59% 66% 3.48<br />

O<strong>the</strong>r cattle<br />

(excl. calves)<br />

50% 18% 2.7<br />

Calves 45% 0% 1.46<br />

Dry sow 100% 35% 0.63<br />

Sows plus litters 100% 75% 0.63<br />

Fattening pig<br />

(20 – 130kg)<br />

90% 33% 0.49<br />

Weaners<br />

(


54<br />

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Currently <strong>the</strong> majority of <strong>the</strong>se residues are recycled <strong>to</strong> agricultural land. The high water content makes<br />

large scale transportation unfeasible, and so utilisation for energy or fuel generation would likely be at a<br />

local scale.<br />

Dry Agricultural Residues<br />

There has been much interest in <strong>the</strong> use of dry agricultural residues for energy for some time. The UK<br />

Government (<strong>the</strong>n Department of Energy) supported a significant programme in <strong>the</strong> 1980s-early 1990s <strong>to</strong><br />

examine <strong>the</strong> potential and support demonstration projects. Two main dry agricultural residues were<br />

identified as: poultry litter and straw.<br />

Straw<br />

Straw is available from cereal and o<strong>the</strong>r 'combinable' crops such as oil seeds. The recent <strong>report</strong> <strong>by</strong> CSL<br />

for NNFCC gives a broad description of <strong>the</strong> straw market. 78 It is produced seasonally and is localised <strong>to</strong><br />

arable farming areas. Straw is produced during crop harvest and often remains on <strong>the</strong> ground after <strong>the</strong><br />

passage of stage one collection – <strong>the</strong> seed crop. It must <strong>the</strong>n be collected and baled in a second<br />

handling stage. For an estimation of regional crop area potentially generating straw, <strong>by</strong> crop type and<br />

region of <strong>the</strong> UK please see Appendix 1.<br />

The three main types of straw that are available in <strong>the</strong> UK are barley, wheat and oil seed rape (OSR). It<br />

is common for barley and oat straw <strong>to</strong> be consumed almost entirely <strong>by</strong> <strong>the</strong> lives<strong>to</strong>ck industry as part of <strong>the</strong><br />

winter diet with additional straw used for bedding, so this must be borne in mind when considering <strong>the</strong><br />

following figures. Cereal straw is also used <strong>to</strong> protect some crops, such as carrots, against frost and <strong>to</strong><br />

keep o<strong>the</strong>rs, such as strawberries, off <strong>the</strong> ground. OSR straw is not suitable for ei<strong>the</strong>r of <strong>the</strong>se uses.<br />

O<strong>the</strong>r potential industrial uses for straw are for paper-making, or in <strong>the</strong> production of industrial fibre,<br />

including constructional board manufacture. 79 Straw can also be used as a feeds<strong>to</strong>ck for power<br />

generation, as is <strong>the</strong> case at <strong>the</strong> EPRL Power station in Ely (see later chapter). OSR straw is popular for<br />

combustion, as it burns fiercely due <strong>to</strong> <strong>the</strong> presence of residual oilseeds. To moderate this, such straw is<br />

mixed with cereal straws <strong>to</strong> contain this volatility at lower levels.<br />

To prevent deterioration during s<strong>to</strong>rage, crops are generally harvested dry, i.e. moisture content below<br />

15% and, as straw is usually harvested immediately after harvesting <strong>the</strong> associated cereal or oilseed<br />

crop, its moisture content will be around <strong>the</strong> same. During poor wea<strong>the</strong>r, however, <strong>the</strong> crops may be<br />

harvested at higher moisture contents, meaning <strong>the</strong> straw will be wetter, or <strong>the</strong> straw may spoil in <strong>the</strong><br />

field, reducing that year’s yield.<br />

Straw is harvested over a short period (typically around 70 days), and for <strong>the</strong> remainder of <strong>the</strong> year<br />

s<strong>to</strong>rage is required. This s<strong>to</strong>rage may be done in Dutch barns or in stacks on <strong>the</strong> field. There will usually<br />

be some losses in dry matter during s<strong>to</strong>rage, mainly due <strong>to</strong> degradation of biomass. This loss is<br />

estimated <strong>to</strong> be around 10-20% of dry matter. Straw s<strong>to</strong>red in <strong>the</strong> open (piles of bales in <strong>the</strong> field) can<br />

also be damaged <strong>by</strong> rainwater and <strong>the</strong> outer bales in <strong>the</strong> stack may rot and be lost. Problems can be<br />

avoided <strong>by</strong> choosing <strong>the</strong> s<strong>to</strong>rage sites care<strong>full</strong>y. If s<strong>to</strong>red damp and under cover, some self-heating can<br />

occur – a potential fire hazard.<br />

A number of estimates for <strong>the</strong> quantity of straw available across <strong>the</strong> UK have been made, however in<br />

reality it varies from year <strong>to</strong> year, depending on <strong>the</strong> harvest and on alternative market demand for straw.<br />

Existing traditional agricultural uses such as lives<strong>to</strong>ck bedding and feed, animal feed compounding, crop<br />

protection and composting consume significant and varying amounts of straw each year. 80<br />

78<br />

National and Regional Supply/demand balance for agricultural straw in Great Britain, Copeland, J., Turley, D., Central Science Labora<strong>to</strong>ry for <strong>the</strong><br />

NNFCC, 2008.<br />

79<br />

ETSU New and Renewable Energy: Prospects in <strong>the</strong> UK for <strong>the</strong> 21st Century: Supporting Analysis.<br />

80<br />

ETSU BM/04/00056/REP/3 (1999) Energy from Biomass: summaries of <strong>the</strong> biomass projects carried out as part of <strong>the</strong> Department of Trade and<br />

Industry’s New and Renewable Energy Programme Volume 5: Straw, poultry litter and energy crops.


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The Carbon Trust’s biomass study for 2003 estimated straw production <strong>to</strong> vary between 10 and 12 million<br />

<strong>to</strong>nnes per annum of which around 25% would be available for use in future energy solutions. 81 The<br />

Royal Commission on Environmental Pollution (RCEP) <strong>report</strong> indicated an availability of 24 million <strong>to</strong>nnes<br />

in 2002. 82 The Biomass Task Force, provided an estimate of 3-4.5 million <strong>to</strong>nnes of straw available for<br />

energy generation per annum. 83.84 The most recent <strong>report</strong> <strong>by</strong> <strong>the</strong> CSL in 2008 estimated that 60% of<br />

straw could be recovered from <strong>the</strong> field, approximately 2.75 – 4 t/ha, and of this 4.9 million <strong>to</strong>nnes would<br />

be available for non-traditional uses in Great Britain, once operational and future straw burning Power<br />

Stations had been taken in<strong>to</strong> account (<strong>to</strong>tal straw arising 11.9 million <strong>to</strong>nnes).<br />

Most of <strong>the</strong>se figures refer only <strong>to</strong> England and Wales. Work for SEERAD indicated that most of <strong>the</strong><br />

straw in Scotland has a <strong>read</strong>y market and <strong>the</strong>re is no or very little surplus in Scotland. 85<br />

The straw arising figures below have used <strong>the</strong> assumption of 3.5 <strong>to</strong>nnes of straw produced per ha in <strong>the</strong><br />

UK, <strong>to</strong>ge<strong>the</strong>r with an availability of 25% for non-traditional uses (such as future energy solutions and<br />

fuels) as described in <strong>the</strong> Carbon Trust <strong>report</strong>. 86<br />

Using <strong>the</strong> above assumptions, an estimation of <strong>the</strong> straw arisings can be made, as well as <strong>the</strong> amount of<br />

straw that might be available for non-traditional uses such as energy generation and transport fuels.<br />

81 Biomass sec<strong>to</strong>r review for <strong>the</strong> Carbon Trust, 2005, Paul Arwas Associates and Black & Vetch Ltd.<br />

82 Royal Commission on Environmental Pollution, 2004, Biomass as a renewable energy source, www.rcep.org.uk/biomass/Biomass%20Report.pdf<br />

83 According <strong>to</strong> Defra Statistics <strong>the</strong> amount of land on which cereals were harvested varied from 3,014,000 <strong>to</strong> 4,026,000 ha over <strong>the</strong> pass 20 years. As<br />

<strong>the</strong> yield of straw varies from 3-4 t/ha, this translates in<strong>to</strong> a range of just over 9Mt just over 16Mt of straw produced in <strong>the</strong> UK per annum. The<br />

availability of straw for energy will <strong>the</strong>n depend on <strong>the</strong> market for alternative use, but is typically about a third of <strong>the</strong> <strong>to</strong>tal available. See:<br />

www.defra.gov.uk/esg/publications/auk/200/3-2.xls<br />

84 Biomass Task Force <strong>report</strong> <strong>to</strong> Government, Oc<strong>to</strong>ber 2005.<br />

85 MLURI, SAC and AEA Technology 2003 Energy from Crops in Scotland. Timber and Agricultural residues Technical Annex.<br />

86 J Nix Farm Management Handbook, 3 rd Edition 2005.<br />

55


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Table 24 Prediction of straw arisings and availability for non-traditional uses.<br />

Year<br />

Region Straw Estimation<br />

(‘000 <strong>to</strong>nnes)<br />

2003 2004 2005 2006 2007 2008<br />

East Midlands Total Straw<br />

Straw available non-<br />

2630 2673 2564 2513 2606<br />

traditional use 658 668 641 628 651<br />

East of Total Straw 1951 2035 1915 1899 1980<br />

England Straw available nontraditional<br />

use 488 509 479 475 495<br />

North East Total Straw<br />

Straw available non-<br />

478 491 471 456 472<br />

traditional use 120 123 118 114 118<br />

North West Total Straw<br />

Straw available non-<br />

266 298 272 262 267<br />

traditional use 67 74 68 66 67<br />

South East Total Straw 1451 1473 1408 1388 1423<br />

and London Straw available nontraditional<br />

use 363 368 352 347 356<br />

South West Total Straw<br />

Straw available non-<br />

1236 1290 1207 1186 1217<br />

traditional use 309 322 302 297 304<br />

West Midlands Total Straw<br />

Straw available non-<br />

923 955 909 890 927<br />

traditional use 231 239 227 223 232<br />

Yorkshire and Total Straw 1444 1514 1436 1383 1450<br />

Humber Straw available nontraditional<br />

use 361 378 359 346 363<br />

England Total Straw available nontraditional<br />

use 2595 2682 2546 2494 2586<br />

Scotland Total Straw<br />

Straw available non-<br />

1551 15889 1493 1428 1463 1638<br />

traditional use 388 397 373 357 366 410<br />

Wales Total Straw<br />

Straw available non-<br />

144 153 139 130<br />

traditional use 36 38 35 32<br />

Nor<strong>the</strong>rn Total Straw 125 123 126 120 112<br />

Ireland Straw available nontraditional<br />

use 31 31 31 30 28<br />

UK - Total Straw available nontraditional<br />

use 3049 3149 2984 2912<br />

As can be seen from <strong>the</strong> above data, <strong>the</strong>re is potentially considerable resource available without<br />

disturbing traditional markets. Dry straw has an energy content of around 18GJ/dry <strong>to</strong>nnes, which is<br />

independent of straw type.<br />

Availability<br />

Agricultural residues are generally large in volume and bulky <strong>to</strong> transport. As such transportation costs<br />

usually prohibit movement of <strong>the</strong>se residues significant distances. High density straw bales are an<br />

exception but it remains a low value commodity and any facility intending <strong>to</strong> make use of <strong>the</strong>se residues<br />

would ideally be constructed near <strong>to</strong> a significant supply of resource and so would be at local or regional<br />

scale.


Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Wastes and Energy<br />

AEA/ED45551/Issue 1<br />

In terms of straw, <strong>the</strong> CSL Report identified that Wales and Scotland have straw deficits, while England is<br />

a net exporter of straw once regional lives<strong>to</strong>ck demand had been subtracted from <strong>the</strong> arisings. In addition<br />

<strong>the</strong> conversion of straw <strong>to</strong> energy products would remove <strong>the</strong> straw from <strong>the</strong> fields, removing a nutrient<br />

source (see Appendix 1 for <strong>the</strong> cost quantification of this nutrient source). The decision whe<strong>the</strong>r <strong>to</strong> sell<br />

straw is a balance between <strong>the</strong> price, soil type and suitability for reincorporation, timing for <strong>the</strong> next crop<br />

and <strong>the</strong> cost of replacement fertiliser.<br />

Poultry Litter<br />

The vast majority of poultry raised for meat, broilers, are farmed using intensive farming methods, with <strong>the</strong><br />

use of bedding. This enables easy collection of <strong>the</strong> residues produced, which are commonly high in solid<br />

content with little liquid present. The litter is also usually high in ammonia. 80 The fresh manure is<br />

approximately 75% water, but dries considerably over <strong>the</strong> time it spends in <strong>the</strong> enclosed house. 87<br />

Bedding materials are usually wood shavings, shredded paper or straw, which become mixed with<br />

droppings.<br />

Traditionally poultry litter was applied <strong>to</strong> <strong>the</strong> land as a fertiliser, but as with cow and pig slurry, <strong>the</strong> rise in<br />

poultry production and <strong>the</strong> decreasing availability of land mean that <strong>the</strong> potentially deleterious<br />

environmental impacts are being recognised and <strong>the</strong> traditional litter disposal methods are being<br />

discouraged. Poultry litter is considered a waste under <strong>the</strong> Waste Incineration Directive (WID), and<br />

<strong>the</strong>refore any plant that utilises this resource must be compliant with <strong>the</strong> requirements of WID.<br />

It is estimated that each fowl has <strong>the</strong> equivalent output of 0.036 kg/day (litter plus excreta), with a dry<br />

matter content of 70%. 88 The calorific value of poultry litter is between 8.8 89 and 15 GJ/t and <strong>the</strong> moisture<br />

content varies between 20-50%, 90,91 i.e. a calorific content that is about half that of anthracite coal (32-35<br />

MJ.Kg).<br />

Using <strong>the</strong> litter output estimation of 0.036kg/bird/day and assuming a calorific value of 9 GJ/t estimations<br />

of <strong>the</strong> regional output of poultry litter and its potential energy content are made in Table 25.<br />

Table 25 Total Fowl Numbers raised on bedding, <strong>by</strong> region for <strong>the</strong> UK<br />

Fowls raised on Energy Content<br />

Region<br />

bedding<br />

(GJ)<br />

East Midlands 17,361,450 5,625,110<br />

East of England 22,853,361 7,404,489<br />

North East 2,133,092 691,122<br />

North West 5,809,647 1,882,326<br />

South East inc. London 5,857,657 1,897,881<br />

South West 12,363,066 4,005,633<br />

West Midlands 13,688,062 4,434,932<br />

Yorkshire and Humber 11,888,774 3,851,963<br />

England - Total 91,955,109 29,793,455<br />

Nor<strong>the</strong>rn Ireland 13,923,000 411,052<br />

Scotland 5,388,040 1,745,725<br />

Wales 4,303,711 1,394,402<br />

UK - Total 115,729,164 37,496,249<br />

87<br />

From http://ohioline.osu.edu/b804/804_3.html<br />

88<br />

Poultry Manure (litter and Excreta) in England and Wales in Relation <strong>to</strong> <strong>the</strong> Regional Electricity Companies, ADAS, 1993,<br />

http://www.berr.gov.uk/files/file14939.pdf<br />

89<br />

Estimated average calorific values of fuels – 2004, BERR, http://www.berr.gov.uk/files/file19273.xls<br />

90 st<br />

ETSU R-122: New and Renewable Energy: Prospects for <strong>the</strong> UK for <strong>the</strong> 21 Century, Supporting Analysis.<br />

91<br />

Poultry litter as a fuel, World’s Poultry Science Journal, 49, 175-177, Dagnall, S., 1993.<br />

57


58<br />

Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Wastes and Energy<br />

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The estimated poultry litter resource in <strong>the</strong> UK is around 1.3 million <strong>to</strong>nnes as a significant proportion of<br />

birds are free range, and <strong>the</strong>re will still be considerable sp<strong>read</strong>ing <strong>to</strong> land occurring. 92 Approximately half<br />

of <strong>the</strong> 1.3 million <strong>to</strong>nnes is al<strong>read</strong>y committed <strong>to</strong> EPRL (Energy Power Resources Limited) energy from<br />

waste plants, generally from <strong>the</strong> largest commercial poultry farmers. Such plants are at Thetford, Eye<br />

and Westfield, <strong>the</strong> centres of <strong>the</strong> UK poultry industry (see later for more information).<br />

4.5.3 Conclusion<br />

Controlled agricultural wastes such as sacks, chemical residues etc are <strong>to</strong>o heterogeneous <strong>to</strong> be a viable<br />

feeds<strong>to</strong>ck.<br />

Agricultural residues have a large potential <strong>to</strong> be utilised for energy. The residues split in<strong>to</strong> two types –<br />

dry residues that can be utilised through combustion, and wet residues that have <strong>the</strong> potential <strong>to</strong> be<br />

utilised through AD. In both cases, <strong>the</strong> data for <strong>to</strong>tal arisings do not represent availability for energy as<br />

significant amounts of <strong>the</strong>se materials are used in traditional applications. In addition arisings are<br />

seasonally dependent, straw only arises for a short period in late summer and must be s<strong>to</strong>red, slurries<br />

and manures are largely available only when animals are wintering, or in enclosed spaces. These two<br />

fac<strong>to</strong>rs make <strong>the</strong> availability of residues for energy uncertain and a function of market conditions at any<br />

one time.<br />

We were unable <strong>to</strong> find information on <strong>the</strong> impact that <strong>the</strong> step change in deployment implied <strong>by</strong> <strong>the</strong><br />

Renewable Energy Strategy would have on alternative uses. This may have detrimental effects on some<br />

affected sec<strong>to</strong>rs that will not be offset <strong>by</strong> <strong>the</strong> increases energy business.<br />

4.6 Forestry Residues<br />

4.6.1 Definition<br />

Woodland covers an estimated 2.8 million hectares in <strong>the</strong> UK mainland, of which 1.57 million ha is conifer<br />

and 1.17 million ha broadleaf. 93 On <strong>the</strong> UK mainland, <strong>the</strong> highest proportion of woodland is in Scotland,<br />

49%, England has 41% and Wales has 10%. Nor<strong>the</strong>rn Ireland has a woodland area of 56,997 ha. 94<br />

4.6.2 Composition<br />

Forestry residues are defined as those parts of a tree left on <strong>the</strong> forest floor after harvesting and not<br />

recovered for commercial purpose. Such material originates from forests and woodlands, as primary<br />

processing co-products and from arboricultural arisings.<br />

Forest and woodland residues include: 95<br />

• Harvesting residues: tips of stems (a diameter of less than 7cm) and side branches.<br />

• Small round-wood: small stems removed from side branches with a diameter of 7-14 cm. 96<br />

• Poor quality wood: trees large enough <strong>to</strong> be used for timber, but of such poor quality <strong>the</strong>y would<br />

o<strong>the</strong>rwise be left on site or sold as firewood.<br />

92 st<br />

ETSU R-122: New and Renewable Energy: Prospects for <strong>the</strong> UK for <strong>the</strong> 21 Century, Supporting Analysis.<br />

93<br />

Addressing <strong>the</strong> land use issues for non-food crops, in response <strong>to</strong> increasing fuel and energy generation opportunities, NNFCC 2008,<br />

http://www.nnfcc.co.uk/metadot/index.pl?id=8253;isa=DBRow;op=show;dbview_id=2539<br />

94<br />

Forest Service, 2002. Facts and Figures, http://www.forestserviceni.gov.uk/factfigures01-02.pdf<br />

95<br />

About Woodfuel, Forest Research, 2003,<br />

http://www.eforestry.gov.uk/woodfuel/pages/AboutWoodfuel.jsp#Primaryprocessingcoproducts<br />

96<br />

Although it could be argued that small round-wood is not a forestry residue but a product. In <strong>the</strong> reference cited small round-wood is included <strong>to</strong><br />

show <strong>the</strong> maximum potential availability. Availability of this resource will depend on price and market conditions.


Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Wastes and Energy<br />

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By utilising <strong>the</strong> above resources from currently under managed woodlands, as outlined in <strong>the</strong> Forestry<br />

Commissions Wood Fuel Strategy (2006), 97 <strong>the</strong>se woodlands could contribute significantly <strong>to</strong> <strong>the</strong> arisings<br />

of forestry residues available for conversion <strong>to</strong> energy or transport fuels.<br />

A potential disadvantage that would need <strong>to</strong> be accounted for is <strong>the</strong> negative effects of removing this<br />

material from a forest, which if removed in excess could result in a decline in soil quality and structure, a<br />

decline in water quality and a decline in carbon sequestration. 98<br />

Production from commercial forestry systems is usually more complex than for annual or perennial energy<br />

crops, since <strong>the</strong> composition of <strong>the</strong> biomass obtained is a mixture of <strong>the</strong> above. 93<br />

The figures used in this section are based on a detailed <strong>report</strong> <strong>by</strong> McKay et al. (2003), <strong>the</strong> Forestry<br />

Commission for <strong>the</strong> DTI, published in 2003. Any detailed information on <strong>the</strong> methodology used <strong>to</strong><br />

calculate <strong>the</strong> forestry residue arising is available from this <strong>report</strong>. McKay et al. (2003) does not provide<br />

forestry residue data for Nor<strong>the</strong>rn Ireland and this is <strong>the</strong>refore collected from o<strong>the</strong>r sources.<br />

Figures in ‘oven dried <strong>to</strong>nnes’ (odt) are often quoted in this area. This refers <strong>to</strong> wood that is completely<br />

dried (i.e. zero moisture content). In reality it is very difficult <strong>to</strong> produce such wood, particularly from virgin<br />

residues and wood fuel is typically available at a range of moisture contents. To overcome issues that<br />

variable moisture content creates for <strong>the</strong> comparison of wood (and o<strong>the</strong>r biomass) fuels, characteristics<br />

such as calorific value are often quoted for odt.<br />

4.6.3 Current arisings<br />

The map of Great Britain from RESTATS shows <strong>the</strong> resource availability of forestry residues. As <strong>the</strong><br />

arising data for forestry residues shows in <strong>the</strong> latter section of this chapter, a vast amount of forestry<br />

residue exists in <strong>the</strong> UK. However <strong>the</strong> availability of <strong>the</strong> resource is an issue since it is al<strong>read</strong>y marketed<br />

<strong>to</strong> o<strong>the</strong>r industries and any remaining residue left on <strong>the</strong> ground contributes <strong>to</strong> effective forestry<br />

management through decomposition and soil nutrient maintenance. Therefore this chapter provides <strong>the</strong><br />

forestry residue arising data, however <strong>the</strong>y are not necessary available for energy projects.<br />

97 A Woodfuel Strategy for England, Forestry Commission, 2006,<br />

http://www.forestry.gov.uk/pdf/fce-woodfuel-strategy.pdf/$FILE/fce-woodfuel-strategy.pdf<br />

98 Forest Residues, Cranfield University, Ian Truckell, http://www.cranfield.ac.uk/sas/naturalresources/research/projects/forestresidues.jsp<br />

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Figure 11 Resource map of forestry residues for <strong>the</strong> UK (oven dried <strong>to</strong>nnes per annum)<br />

(Source: RESTATS 99 – This Yield map was created for <strong>the</strong> EU funded AMOEBA project. For forestry <strong>by</strong>-products, residue fac<strong>to</strong>rs<br />

from management activities, related <strong>to</strong> hectares of crop, were used <strong>to</strong> derive details of <strong>the</strong> available biomass. The information is<br />

presented here in oven dried <strong>to</strong>nnes of material per acre and not per hectares)<br />

The data below gives an estimation of <strong>the</strong> present annual operationally available resource <strong>by</strong> UK region,<br />

i.e. <strong>the</strong> quantity that would be possible <strong>to</strong> make available at roadside, from within <strong>the</strong> Forestry<br />

Commission and private sec<strong>to</strong>r area, without considering existing industries that use <strong>the</strong>se sources. 100<br />

99 Final <strong>report</strong> September 2004, RESTATS: Renewable Energy Statistics Database for <strong>the</strong> United Kingdom, www.restats.org.uk/index.htm<br />

100 McKay H, Hudson J.B. and Hudson R.J (2003) Wood fuel resource in Britain: main <strong>report</strong> (FES B/W3/00787/REP/1, DTI/Pub URN 03/1436,<br />

http://www.berr.gov.uk/files/file15006.pdf. Additional <strong>report</strong>s supplied <strong>by</strong> <strong>the</strong> Forestry Commission, derived from <strong>the</strong>ir website,<br />

http://www.eforestry.gov.uk/woodfuel/pages/Results.jsp


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Table 26 Annual production of potential operationally available forestry residue <strong>by</strong> UK region within <strong>the</strong><br />

Forestry Commission and private sec<strong>to</strong>r area (not considering existing industries.)<br />

Region Forestry and<br />

Woodland<br />

Residue (odt pa)<br />

East Midlands 53,046<br />

East of England 70,489<br />

North East 82,956<br />

North West 86,063<br />

South East and London 94,994<br />

South West 125,633<br />

West Midlands 41,966<br />

Yorkshire and Humberside 63,285<br />

England Total 618,432<br />

Scotland 848,345<br />

Wales 607,701<br />

Nor<strong>the</strong>rn Ireland 101 83,860<br />

UK Total 2,074,478<br />

Although arising data is available for round-wood with diameters<br />

greater than 7cm, <strong>the</strong>se are more likely <strong>to</strong> be used for products and<br />

<strong>the</strong>y are not included in this <strong>report</strong> as a forestry residue.<br />

These estimates do not take economic feasibility in<strong>to</strong> account. For example, resource is not excluded on<br />

<strong>the</strong> basis that it may be <strong>to</strong>o expensive. The actual availability is likely <strong>to</strong> change over time, dependent on<br />

a host of fac<strong>to</strong>rs - including financial support, infrastructure and incentives, transportation costs,<br />

accessibility, harvesting costs, timber prices, and prices of competing co-product markets.<br />

In a separate estimate <strong>the</strong> Forestry Commission estimate that, of <strong>the</strong> <strong>to</strong>tal available resource, 10% of <strong>the</strong><br />

small round-wood and 100% of poor quality stem-wood, stem tips and branches could be made available<br />

<strong>to</strong> new wood fuel projects without serious disruption <strong>to</strong> existing wood-using industries. 97 These<br />

percentages are applied in <strong>the</strong> latter part of this chapter <strong>to</strong> calculate <strong>the</strong> available forestry residues in <strong>the</strong><br />

presence of existing industries.<br />

The figures in Table 26 allow a comparative assessment of <strong>the</strong> forestry and woodlands residues available<br />

for regions in <strong>the</strong> UK. However regional strategies may provide a better understanding of <strong>the</strong> most recent<br />

data on <strong>the</strong> arisings from specific regions, and several regions have produced such strategies. The<br />

criteria and assumptions used for <strong>the</strong> various strategies differ, which makes direct comparisons difficult,<br />

and thus it has not been attempted here.<br />

An alternative method <strong>to</strong> establish forestry residue is <strong>to</strong> use estimates of residue production per hectare.<br />

The two key types of woodland give rise <strong>to</strong> different levels of residue: 102<br />

• Conifer residue: approximately 1.5 odt per hectare per annum (odt/ha pa)<br />

• Broad-leaved residue: approximately 0.4 odt per hectare per annum (odt/ha pa).<br />

Using <strong>the</strong>se assumptions gives a similar, although higher, estimate of woodland residues, as compared <strong>to</strong><br />

Table 26. This is likely due <strong>to</strong> <strong>the</strong> wider scope of such an estimate – unlike that of McKay et al (2003), it<br />

includes forests managed <strong>by</strong> government departments, such as <strong>the</strong> Ministry of Defence and woodland<br />

owned <strong>by</strong> non-governmental organisations.<br />

101<br />

Nor<strong>the</strong>rn Ireland data derived using an alternative method estimated from <strong>the</strong> assumption of <strong>the</strong> residue available relative <strong>to</strong> <strong>the</strong> forestry area as<br />

specified in Table.28.<br />

102<br />

'UK industry wood fuel resource study: England, Wales and Scotland<br />

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Table 27 Forestry residue arisings in <strong>the</strong> UK, based on <strong>to</strong>tal area of 2.8 M ha, and estimates of residue/ha pa 93<br />

Residue<br />

Broad-Leaf<br />

Residue<br />

Conifer<br />

Total<br />

Residue (odt<br />

pa)<br />

Broadleaf Conifer<br />

Region (‘000 ha) (‘000 ha) (odt pa) (odt pa)<br />

England 757 367 302,800 550,500 853,300<br />

Wales 127 158 50,800 237,000 287,800<br />

Scotland<br />

Nor<strong>the</strong>rn<br />

293 1,048 117,200 1,572,000 1,689,200<br />

Ireland 103 15 56 595 83,265 83,860<br />

UK - Total 1,177 1,573 470,800 2,359,500 2,830,300<br />

The <strong>report</strong> <strong>by</strong> McKay et al (2003) does not provide <strong>the</strong> equivalent data for Nor<strong>the</strong>rn Ireland, hence <strong>the</strong> arising data for Nor<strong>the</strong>rn<br />

Ireland in Table 26 has been estimated using <strong>the</strong> above method.<br />

4.6.4 Primary processing co-products<br />

Definition and Composition<br />

The process of converting trees in<strong>to</strong> usable wooden products creates considerable wastage.<br />

Approximately 50% of <strong>the</strong> volume of stem wood that is sold <strong>to</strong> sawmills is usually converted in<strong>to</strong> timber<br />

products such as planks, ba<strong>to</strong>ns, etc. 100 The remainder is commonly called co-product and can include<br />

bark, chips, off cuts and sawdust. Such co-products are normally sold, used for a variety of different<br />

purposes including paper and panel boards manufacture. Hence <strong>the</strong>se products often al<strong>read</strong>y have an<br />

existing market. However, it is anticipated that 10% of all co-products would be available as fuel sources<br />

without major effects on existing industries.<br />

Current Arisings<br />

Table 28 outlines <strong>the</strong> primary processing co-product arising in Great Britain. It can be seen that<br />

approximately 2% is used as wood fuel, most of which is used <strong>by</strong> <strong>the</strong> sawmills <strong>the</strong>mselves. The latest<br />

figures indicate that 83% of co-product is consumed <strong>by</strong> <strong>the</strong> panel board industries.<br />

Table 28 Proportions of primary processing co-products sold for fur<strong>the</strong>r use. 100<br />

Sold <strong>to</strong> Wood Processing<br />

Industries<br />

O<strong>the</strong>r Sales<br />

Weight Co-product Weight Co-product Weight<br />

Co-product (odt pa)<br />

(odt pa)<br />

(odt pa)<br />

Sawdust 158,742 Sawdust 12,890 Sold as bark 95,664<br />

Slabwood 1,039 Slabwood 48 Burnt for heat 11,931<br />

Peeled<br />

Peeled<br />

Disposed<br />

Chips 487,570 Chips 12,161 rubbish/burning 797<br />

Unpeeled<br />

Unpeeled<br />

Total co-<br />

Chips 63,652 Chips 5,411 products 859,002<br />

O<strong>the</strong>r 5,203 Firewood 2,941 O<strong>the</strong>r 953<br />

Exploring <strong>the</strong> arisings at a regional level produces <strong>the</strong> following results:<br />

• Almost half (47%) of <strong>the</strong> co-product originates from Scottish mills, with 34% from England and<br />

19% from Wales.<br />

• Within England <strong>the</strong>re are striking contrasts in arisings with <strong>the</strong> West Midlands accounting for 35%<br />

of English production and 12% of British output but <strong>the</strong> neighbouring East Midlands producing<br />

less than one tenth of <strong>the</strong> table below.<br />

103 Forest Service, 2002. Facts and Figures, http://www.forestserviceni.gov.uk/factfigures01-02.pdf


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Table 29 Regional arising of co-products 104,105<br />

4.6.5 Arboriculture Arisings<br />

Region<br />

Sawmill Co-product<br />

(odt pa)<br />

East Midlands 7,664<br />

East of England 24,577<br />

North East 50,615<br />

North West 37,899<br />

South East 22,191<br />

South West 27,204<br />

West Midlands 100,460<br />

Yorkshire and Humberside 18,969<br />

England - Total 289,579<br />

Scotland 403,538<br />

Wales 165,783<br />

Nor<strong>the</strong>rn Ireland 100,000<br />

UK - Total 958,900<br />

Definition and Composition<br />

Arboriculture sources of wood residues include <strong>the</strong> products of felling, thinning and pruning of trees, and<br />

include residues from maintenance of trees in roadside and public areas throughout <strong>the</strong> UK. Arboricultural<br />

arising data does not exist for Nor<strong>the</strong>rn Ireland.<br />

The residues are usually left on-site in <strong>the</strong> form of chippings or removed <strong>to</strong> landfill. Only a small<br />

proportion is currently used for energy end markets.<br />

The estimations of arboricultural arisings are based on a questionnaire analysis of arboricultural<br />

companies, tree officers and local authorities. 100 Total values for stem wood, branch wood, wood chips<br />

and foliage produced and subsequently sold was ga<strong>the</strong>red. This information was scaled up <strong>by</strong> multiplying<br />

<strong>the</strong> respondent average <strong>by</strong> <strong>the</strong> <strong>to</strong>tal number of contrac<strong>to</strong>rs in each region.<br />

Current Arisings<br />

The South East, including London, contributes about 25% of <strong>the</strong> English resource, while Yorkshire and<br />

Humberside and <strong>the</strong> East Midlands also have substantial arisings: <strong>the</strong>se three regions provide in <strong>to</strong>tal<br />

more than half <strong>the</strong> arisings in Britain. As with <strong>the</strong> o<strong>the</strong>r resources, actual availability of forestry residues<br />

will be dependent on <strong>the</strong> prices offered for wood fuel end uses in comparison <strong>to</strong> those being offered <strong>by</strong><br />

competing markets.<br />

104 The data is taken from About Woodfuel, Forest Research, 2003. The data is derived from <strong>the</strong> 2000 Annual Sawmill Survey and <strong>the</strong> co-incident<br />

Biennial Sawmill Survey carried out <strong>by</strong> <strong>the</strong> Forestry Commission Economics and Statistics Unit (McKay et al 2003). It is based on a voluntary survey<br />

where <strong>the</strong> data from <strong>the</strong> response is scaled up <strong>to</strong> national scale, which is a source of error.<br />

105 The Committee for Agriculture and Rural Development Report in<strong>to</strong> Renewable Energy and Alternative Land Use Nor<strong>the</strong>rn Ireland Assembly, 2007,<br />

http://www.niassembly.gov.uk/agriculture/2007mandate/<strong>report</strong>s/390708R.htm<br />

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Table 30 Aboricultural arisings for Great Britain.<br />

Total Arboricultural Non-marketed Aboricultural<br />

Regions<br />

Arisings (odt pa)<br />

Arisings (odt pa)<br />

East Midlands 63,451 50,636<br />

East of England 46,656 37,357<br />

North East 15,525 11,133<br />

North West 39,445 25,979<br />

South East 157,344 119,160<br />

South West 34,830 27,012<br />

West Midlands 15,445 7,115<br />

Yorkshire and Humber 72,329 23,814<br />

Scotland 16,146 12,448<br />

Wales 11,000 6,841<br />

Great Britain - Total 472,171 321,495<br />

Due <strong>to</strong> <strong>the</strong> voluntary nature of providing this data <strong>the</strong> above figures should be taken as an estimate.<br />

Figure 12 illustrates <strong>the</strong> relative proportion of material produced from <strong>the</strong>se activities.<br />

53%<br />

4%<br />

20%<br />

23%<br />

Foliage<br />

Wood chips<br />

Branch w ood<br />

Stem w ood<br />

Figure 12 Arboricultural arisings <strong>by</strong> <strong>the</strong> material produced (odt/annum)<br />

Potential Forestry resource, without serious disruption <strong>to</strong> existing wood using industries<br />

It is estimated that if all existing forests were actively managed for timber production and material not<br />

suited for use <strong>by</strong> existing markets (e.g construction and board manufacturers) was recovered, 1.9 million<br />

odt of wood from coniferous forest and 2.3 million odt of wood from broadleaved forest could be<br />

harvested each year, giving a <strong>to</strong>tal current forestry biomass resource of 4.2M odt. 93


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It should be noted though that this figure ignores environmental constraints such as long-term site<br />

sustainability, and physical and economic constraints such as cost of harvesting and extracting this<br />

material from <strong>the</strong> forest.<br />

Making several assumptions on market availability allows <strong>the</strong> availability of arboricultural arisings <strong>to</strong> be<br />

calculated, without serious disruption of existing wood using industries. 100<br />

Assumptions on available arisings:<br />

• 10% of <strong>the</strong> small round-wood<br />

• 100% of poor quality stem-wood, stem tips and branches<br />

• 10% of sawmill product<br />

• On average, 70% of arboricultural arisings<br />

• 100% of material from clearance of utilities and roadside maintenance<br />

The <strong>to</strong>tal potential operationally available forestry residue quantity in Great Britain, in <strong>the</strong> absence of<br />

competing markets, is 3.12 million odt per annum. The main material is small round-wood, followed <strong>by</strong><br />

sawmill co-product (potential <strong>to</strong> contribute around 1.03 and 0.86 million odt per annum respectively), with<br />

arboricultural arisings providing about 14% of <strong>the</strong> <strong>to</strong>tal. Approximately equal quantities are available in<br />

England and Scotland but <strong>the</strong> composition is substantially different. Arboricultural arisings form <strong>the</strong> major<br />

element in England though sawmill co-product, small round-wood, and branches are all significant<br />

components. In Scotland and Wales, small round-wood and sawmill co-products are <strong>the</strong> dominant<br />

resources with all o<strong>the</strong>r resource streams playing only a minor part at <strong>the</strong> moment. It may be argued that<br />

small round-wood is in fact a product and not a residue, however it has been considered that 10% of<br />

small round-wood may be available for use without serious disruption <strong>to</strong> existing wood using industries,<br />

hence it is included within <strong>the</strong> arisings data. 100<br />

Table 31 Current potential operationally available forestry residue resources <strong>by</strong> region, taking in<strong>to</strong> account<br />

competing markets<br />

Total Forests<br />

and Woodlands<br />

(odt pa)<br />

Arboricultural<br />

arising<br />

(odt pa)<br />

Region<br />

Sawmill Coproduct<br />

(odt pa)<br />

East Midlands 39,940 7,664 50,636 98<br />

East of England 45,123 24,577 37,357 107<br />

North East 21,689 50,615 11,133 83<br />

North West 53,678 37,899 25,979 118<br />

South East 50,888 22,191 119,160 192<br />

South West 77,911 27,204 27,012 132<br />

West Midlands<br />

Yorkshire and<br />

23,102 100,460 7,115 131<br />

Humberside 35,654 18,969 23,814 78<br />

England - Total 347,985 289,579 301,933 939<br />

Scotland 302,392 403,538 12,448 718<br />

Wales 157,707 165,783 6,841 330<br />

Great Britain - Total 1,987<br />

Total<br />

(‘000 odt pa)<br />

Future Arisings<br />

Information presented here is an approximation of all British forests and woodlands. There is great<br />

uncertainty about <strong>the</strong> future climate and <strong>the</strong> response of forests <strong>to</strong> that climate. 106 This applies <strong>to</strong> both<br />

direct effects (e.g. in <strong>the</strong> absence of nutrient and water limitations, growth is expected <strong>to</strong> increase due <strong>to</strong><br />

106 Forestry Commission, 2002, National Inven<strong>to</strong>ry of Woodland and Trees http://www.forestresearch.gov.uk/pdf/niengland.pdf/$FILE/niengland.pdf<br />

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increased CO2 and temperature) and indirect effects (e.g. higher winter temperatures are expected <strong>to</strong><br />

increase <strong>the</strong> fecundity of deer and reduce tree growth through increased browsing).<br />

In addition harvesting and thinning plans are not binding and will be influenced <strong>by</strong> a range of fac<strong>to</strong>rs:<br />

policy related, practical and commercial. These are likely <strong>to</strong> have significant consequences for future<br />

forestry residue resources even though <strong>the</strong>y cannot be quantified at <strong>the</strong> moment. 100<br />

• Forestry residue forecast<br />

Forestry residue in <strong>the</strong> form of small round-wood, poor quality stems, branches, tips and foliage<br />

from traditional forestry is expected <strong>to</strong> remain relatively stable at just under 2 million odt per<br />

annum up <strong>to</strong> 2020.<br />

• Private Sec<strong>to</strong>r residue forecast<br />

Small round-wood, poor quality stems, stem tips, branches and foliage <strong>to</strong>ge<strong>the</strong>r increase <strong>to</strong> 1.35<br />

million odt <strong>by</strong> 2012-2016, followed <strong>by</strong> a slight decrease 1.3 million odt <strong>to</strong> 2020.<br />

• Public Sec<strong>to</strong>r residue forecast<br />

Available biomass from <strong>the</strong> public sec<strong>to</strong>r is about half that predicted for private sec<strong>to</strong>r.<br />

Considering small round-wood, tips, branches and foliage (<strong>the</strong>re is no equivalent category <strong>to</strong> poor<br />

quality stems in <strong>the</strong> public sec<strong>to</strong>r), <strong>the</strong> prediction is that <strong>to</strong>tal biomass remains around 617k odt pa<br />

across Great Britain for 2007 – 2016, after which it falls slightly <strong>to</strong> reach 599k odt per annum <strong>by</strong><br />

2021.<br />

Table 32 Summary of future Woodland Arisings across Great Britain, private and public sec<strong>to</strong>r.<br />

Country Forecast Period Total Arising<br />

(odt pa)<br />

Scotland 2007-2011 931,062<br />

2012-2016 1,033,598<br />

2017-2021 1,019,815<br />

Wales 2007-2011 274,794<br />

2012-2016 260,346<br />

2017-2021 242,563<br />

England 2007-2011 664,083<br />

2012-2016 669,653<br />

2017-2021 637,862<br />

Nor<strong>the</strong>rn Ireland 107 2020 21,000 – 30,000<br />

• Primary processing co-products forecast<br />

o The proportions of smaller and poor quality arisings are expected <strong>to</strong> remain stable in <strong>the</strong><br />

near future. However <strong>the</strong> availability of larger dimension material is expected <strong>to</strong> increase<br />

substantially. For example, stem-wood of 18+cm diameter is forecasted <strong>to</strong> increase from<br />

3.8 million odt per annum in 2003-2006 <strong>to</strong> 5.4 million odt per annum in 2017-2021.<br />

Assuming that <strong>the</strong> sawmilling sec<strong>to</strong>r uses this resource, co-product will increase<br />

proportionately.<br />

o In addition <strong>the</strong>re is some indication that, compared <strong>to</strong> <strong>the</strong> present harvest, <strong>the</strong> form of<br />

larger dimension material is poorer than in material that will reach felling age in <strong>the</strong> next<br />

20 years or so years. Conversion efficiency is <strong>the</strong>refore expected <strong>to</strong> fall with a<br />

concomitant increase in co-product unless saw-milling technology can make parallel<br />

improvements.<br />

o In Nor<strong>the</strong>rn Ireland <strong>the</strong> forecast for 2020 is 50,000 – 200,000 odt pa, depending on<br />

whe<strong>the</strong>r a minimum or maximum scenario is pursued.<br />

107 Assessment of <strong>the</strong> potential for bioenergy development in Nor<strong>the</strong>rn Ireland, AEA, 2008,<br />

http://www.detini.gov.uk/cgi-bin/downutildoc?id=2314.


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• Arboricultural forecast<br />

Although operationally available arboricultural arisings cannot be forecast with any certainty, it is<br />

estimated that it is unlikely <strong>to</strong> change dramatically. However, it is expected that arboricultural<br />

arisings will increase. This can be found in more detail Appendix 1.<br />

4.6.6 Conclusions for Forestry Residues<br />

The UK has considerable natural wood resource, one that is not <strong>full</strong>y exploited at <strong>the</strong> moment and thus<br />

<strong>the</strong>re is considerable room for use of this material in future energy solutions. However, traditional and<br />

existing markets must be borne in mind, as must market conditions that will affect <strong>the</strong> cost of such a<br />

resource. In addition <strong>the</strong> environmental implications of removing significantly more natural wood arisings<br />

from land, and <strong>the</strong> impact this may have on future land quality and embedded carbon need fur<strong>the</strong>r<br />

assessment.<br />

The figures discussed here are <strong>the</strong> maximum practicable resource. For such quantities <strong>to</strong> be available a<br />

market for <strong>the</strong> product must exist and funding or incentives would be needed <strong>to</strong> set up <strong>the</strong> equipment and<br />

s<strong>to</strong>rage necessary. Currently <strong>the</strong>re are limited supply chain connections, thus this quantity of wood could<br />

not be brought <strong>to</strong> <strong>the</strong> market in a short timeframe.<br />

The availability and feasibility of using wood based fuels is dependent on <strong>the</strong> policy framework. One such<br />

recent example of <strong>the</strong> Woodfuel Strategy for England (2006) has a target <strong>to</strong> bring an additional 2 million<br />

<strong>to</strong>nnes of woodfuel <strong>to</strong> <strong>the</strong> market, annually <strong>by</strong> 2020 from forestry residues supported <strong>by</strong> o<strong>the</strong>r sources<br />

such as arboricultural arisings and recovered wood. All <strong>the</strong> wood resource described above is clean,<br />

untreated wood, and is <strong>the</strong>refore eligible as biomass fuels under <strong>the</strong> current legislation, and are exempt<br />

from <strong>the</strong> Waste Incineration Directive.<br />

4.7 Conclusions<br />

Waste, both controlled wastes and biological residues, represents a massive potential resource in <strong>the</strong> UK.<br />

Although significant amounts of such materials are al<strong>read</strong>y recycled, especially from MSW waste<br />

streams, or recycled on<strong>to</strong> land, as with many agricultural residues, a considerable amount of waste still<br />

exists and disposing of it is a challenge.<br />

Much of <strong>the</strong> residual waste that is disposed of through incineration or <strong>to</strong> landfill could potentially be more<br />

efficiently utilised, and may be a feeds<strong>to</strong>ck for <strong>the</strong> generation of energy or transport fuels.<br />

Summary of Waste Arisings<br />

• Municipal Solid Waste (MSW) is comprised of a very large range of materials, and <strong>to</strong>tal waste<br />

arisings are increasing. Data quality is good, and in 2007/08 <strong>the</strong> UK MSW arisings were 344<br />

million <strong>to</strong>nnes. Even if <strong>the</strong> level produced <strong>by</strong> each household were <strong>to</strong> remain constant, <strong>the</strong><br />

increasing number of households will result in increasing arisings. Recycling initiatives decrease<br />

<strong>the</strong> proportion of waste going straight for disposal, and <strong>the</strong> level of recycling is increasing each<br />

year. Most growth forecasts use a growth rate of 0.75% per annum.<br />

• Commercial and Industrial waste (C&I) is also comprised of a very large range of materials, with<br />

levels at 83 million <strong>to</strong>nnes in 2002/03. Overall levels of industrial waste are decreasing, while<br />

levels of commercial wastes are increasing. Again, recycling initiatives decrease <strong>the</strong> proportion<br />

of waste going straight for disposal, and <strong>the</strong> level of recycling is increasing each year, although in<br />

general recycling is not as advanced as for MSW. Growth rates have been taken as 1% per<br />

annum for commercial waste, and 0% per annum for industrial waste.<br />

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• Construction and Demolition waste (C&D) is largely comprised of mineral waste, with small<br />

amounts of wood, plastics and metals. Most investigation of this waste stream has been<br />

concerned with recycling <strong>the</strong> mineral proportion in<strong>to</strong> aggregate. Of <strong>the</strong> three controlled waste<br />

streams is produces <strong>the</strong> greatest amount, estimated at 118.6 million <strong>to</strong>nnes of waste in 2005.<br />

• Biosolids are produced from waste water treatment sites, as <strong>the</strong> main <strong>by</strong>-product. Data quality is<br />

generally good and in 2004-5 1.72 Mt of dry bio-solids were produced. Estimations are that this<br />

will increase <strong>to</strong> 2.5 Mt <strong>by</strong> 2030 due <strong>to</strong> an increasing number of households and tighter waste<br />

water and pollutions controls through legislation.<br />

• Agricultural residues include <strong>the</strong> wet residues of manures and slurries, and <strong>the</strong> dry residues of<br />

straw and poultry litter. Levels of available straw (after traditional uses) for 2006 were estimated<br />

<strong>to</strong> be 2.9 million <strong>to</strong>nnes for <strong>the</strong> UK, while poultry litter with an energy content of 37 million GJ was<br />

produced. Manures and slurries from cattle were estimated <strong>to</strong> produce a <strong>to</strong>tal, collectable, 9.9<br />

million kg/day of volatile solids, pigs 669 thousand kg/day of volatile solids and fowls 1.8 million<br />

kg/day of volatile solids. Accurate current and future arisings are difficult <strong>to</strong> predict as <strong>the</strong> sec<strong>to</strong>r<br />

is so dependent on wea<strong>the</strong>r, farming practices and markets. Apart from poultry litter, where<br />

approximately 50% is al<strong>read</strong>y committed <strong>to</strong> energy from waste plants, <strong>the</strong> residues are recycled<br />

<strong>to</strong> land.<br />

• Forestry residues arise from forests and woodlands, primary processing co-products and<br />

arboricultural work. Total available forestry residues in <strong>the</strong> UK are estimated <strong>to</strong> be 1,987 odt per<br />

annum, although it is unlikely this <strong>full</strong> amount could be realised for energy, and <strong>the</strong> data quality is<br />

generally uncertain. Some future estimations show an increase of material available, but no<br />

significant changes are expected.


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5 Arisings of components suitable for<br />

energy<br />

Chapter 4 presented an overview of <strong>the</strong> waste arisings <strong>by</strong> origin across <strong>the</strong> UK. In this chapter we<br />

discuss those components that are commonly cited as suitable for energy and fuel solutions.<br />

Each of <strong>the</strong> waste types discussed here is a subsection of, and a combination of, those al<strong>read</strong>y detailed<br />

above. The arisings presented here <strong>the</strong>refore do not represent additional arisings, but ra<strong>the</strong>r double<br />

counting.<br />

Many of <strong>the</strong>se streams are <strong>to</strong> some degree al<strong>read</strong>y collected separately and used directly for energy or<br />

being traded as fuel. This is a tendency that will increase as demand for renewable fuels increases as a<br />

result of <strong>the</strong> Renewables Obligation and Renewable Heat Incentive.<br />

Immediately identifiable arisings that could provide a biomass resource include:<br />

1. Wood residues: forestry (e.g. thinnings), virgin and treated wood processing waste, used wood.<br />

2. Agricultural residues: dry residues such as straw, husks and poultry litter, and wet residues such<br />

as manures and slurries.<br />

3. Municipal solid wastes including refuse derived fuels, kitchen wastes and garden wastes.<br />

4. Industrial and commercial wastes which include food and drink processing residues, tallow, meat<br />

and bone meal, pulp and paper sludges and liquors, textile residues, recovered vegetable oils.<br />

Those waste materials that have adequate data available, have been discussed. The pulling <strong>to</strong>ge<strong>the</strong>r of<br />

information from different waste streams allows a comprehensive picture of <strong>the</strong> <strong>to</strong>tal resource <strong>to</strong> be given.<br />

5.1 Waste Wood<br />

Background<br />

In this section <strong>the</strong> arisings of treated and post-consumer waste wood are evaluated. Clean waste wood<br />

from untreated wood processing is included in <strong>the</strong> section on forest residues and not included here.<br />

Each year in <strong>the</strong> UK it is estimated that over 7.5 million <strong>to</strong>nnes of wood waste is produced, approximately<br />

1.8% of <strong>to</strong>tal UK waste arisings. Of this over 80% is landfilled, 16% recycled and reused, and energy<br />

recovered from 4%. 108 Taking in<strong>to</strong> account recent economic developments and <strong>the</strong> slowing of <strong>the</strong><br />

economy, it is likely that this amount will fall in <strong>the</strong> short term. Indeed <strong>the</strong>re are al<strong>read</strong>y <strong>report</strong>s that wood<br />

recyclers are dropping <strong>the</strong> fees <strong>the</strong>y charge <strong>to</strong> take in wood, as <strong>the</strong> levels being disposed of go down.<br />

The decrease is most noticeable from <strong>the</strong> construction sec<strong>to</strong>r, and is believed <strong>to</strong> be having a knock on<br />

effect on <strong>the</strong> chipboard and wood panel producers. 109<br />

The markets for virgin untreated wood have developed rapidly in recent years due <strong>to</strong> <strong>the</strong> expansion of<br />

biomass heating in particular. The use of waste wood has not developed in a similar way. Treated waste<br />

wood includes anything that has had a surface coatings applied <strong>to</strong> it such as paints and varnishes or<br />

impregnation with preservative. The Waste Incineration Directive (WID) requires that combustion of wood<br />

waste containing heavy metals or halogenated hydrocarbons must meet strict emissions limits; cleaner<br />

wood is excluded for <strong>the</strong> purpose of combustion, but mixtures are usually regarded as contaminated for<br />

<strong>the</strong> purposes of combustion. Thus it is possible <strong>to</strong> recover energy in <strong>the</strong> form of power and heat from this<br />

contaminated wood, but pollution abatement must be installed <strong>to</strong> ensure <strong>the</strong> emissions limits are not<br />

108 Carbon Balances and Energy Impacts of <strong>the</strong> Management of UK Wastes, Defra R&D Project WRT 237, ERM, 2006,<br />

http://www.resourcesnotwaste.org/members/conf-application-form/Carbon&Waste(ERM).pdf<br />

109 Wood recyclers slash gate fees, 04-02-2009, Lets recycle.com,<br />

http://www.letsrecycle.com/do/ecco.py/view_item?listid=37&listcatid=217&listitemid=10989<br />

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exceeded. 110 Waste wood could potentially become a valuable energy resource, but <strong>the</strong> market lacks<br />

tight specifications for <strong>the</strong> quality of wood sourced. 111<br />

One of <strong>the</strong> main barriers <strong>to</strong> utilisation of this resource is that <strong>the</strong> types and volumes of waste wood are<br />

largely unknown. 112,113 Treated and post-consumer waste wood is generated from a number of different<br />

sources: 112<br />

• Municipal solid waste (all waste collected under local authority contracts)<br />

• Industrial wood processing (such as furniture manufacture, including kitchen, office, exhibition or<br />

shop fitting furniture),<br />

• Industrial waste,<br />

• Commercial and business waste (e.g. from refurbishment),<br />

• Construction and demolition waste and<br />

• Packaging and pallets.<br />

Data sources<br />

The data used <strong>to</strong> compile this chapter is taken from sources such as Defra, <strong>the</strong> Environment Agency and<br />

WRAP (Waste and Resource Action Programme), in particular <strong>the</strong> 2005 WRAP <strong>report</strong> <strong>by</strong> Nikitas et al.<br />

which was identified as <strong>the</strong> most authoritative work <strong>to</strong> date, and reviews and ranks all previous sources.<br />

These comprehensive reviews and surveys of specific sec<strong>to</strong>rs have been used and extrapolated from <strong>to</strong><br />

generate a picture for regions of <strong>the</strong> UK. This method provides estimates but <strong>the</strong>re is a danger in putting<br />

<strong>to</strong>o much reliance on it – <strong>the</strong>re are big uncertainties and <strong>the</strong>re are also likely <strong>to</strong> be large variations with<br />

time, depending on economic activity, particularly if large companies leave <strong>the</strong> UK or change <strong>the</strong>ir<br />

business.<br />

Packaging waste does not come under any specific waste stream and so is covered briefly in Box 1.<br />

Box 1. Packaging waste<br />

Packaging waste is not a specific waste stream, but arises from municipal, commercial, industrial<br />

and construction waste streams. The most significant type of waste wood arisings are those from<br />

pallets, but in addition packaging waste wood is also generated from cases, boxes, crates, cable<br />

drums, casks and barrels. All of <strong>the</strong>se categories are largely made from softwood.<br />

Waste wood from packaging in <strong>the</strong> commercial and industrial sec<strong>to</strong>r was estimated <strong>to</strong> generate<br />

arisings of nearly 900,000 <strong>to</strong>nnes in 1998. Important quantities of packaging waste are also<br />

believed <strong>to</strong> arise on construction sites.<br />

Data on wood packaging waste across <strong>the</strong> different waste streams is available from Timcon<br />

(Timber Packaging and Pallet Confederation). The estimated <strong>to</strong>tal <strong>to</strong>nnage in <strong>the</strong> UK for 2004 was<br />

about 1.4 million <strong>to</strong>nnes in 2004. However, this data is taken from Prodcom, based on survey<br />

samples of UK manufacturers, and presumably importers and exporters. Timcon’s view is that this<br />

data is of poor quality.<br />

110 The potential use of waste wood in <strong>the</strong> North East as an efficient biomass fuel source , K Coombs,<br />

http://www.northwoods.org.uk/files/northwoods/publications/Northwoods_WasteWoodFuelSource.pdf<br />

111 The environmental regulation of wood, Environment Agency, http://www.environmentagency.gov.uk/static/documents/Business/ps005_2077240.pdf<br />

112 Review of wood waste arisings and management in <strong>the</strong> UK, 2005, Nikitas et al, Published <strong>by</strong> WRAP.<br />

113 ‘Waste wood as a Biomass Fuel’ – Defra, April 2008, ‘UK Biomass Strategy’ – Defra, May 2007


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5.1.1 Municipal Wood Waste<br />

Municipal wood waste comprises of disposal <strong>by</strong> households; for example, furniture, fencing, decking,<br />

wood cuts from DIY, garden wastes and wood packaging. Wood waste from <strong>the</strong> municipal stream is<br />

usually mixed with o<strong>the</strong>r waste and rarely available as a clean source. It would need <strong>to</strong> be separated,<br />

cleaned and processed before it would form a useful wood fuel source, unless it goes <strong>to</strong> mass burn<br />

incineration.<br />

Estimation of waste wood in <strong>the</strong> municipal waste stream is difficult as <strong>the</strong> data represents all household<br />

waste and rarely specifies <strong>the</strong> quantities of specific fractions. However a number of compositional studies<br />

have been performed and are used below.<br />

Current Arisings<br />

Considering <strong>the</strong> available compositional data for MSW waste streams in 2005, <strong>the</strong> estimate percentages<br />

shown in Table 33 were established.<br />

Table 33 Waste wood and furniture waste as a percentage of MSW waste streams<br />

Household Collection<br />

Bulky waste collections<br />

Civic Amenity Site waste<br />

Waste wood Furniture<br />

1.11% (Wales)<br />

1.91% (rest of UK)<br />

0.06% (Wales)<br />

0.18% (rest of UK)<br />

6.03% 37%<br />

12.53% (Wales)<br />

9.05% (rest of UK)<br />

5.86% (Wales)<br />

4.3% (rest of UK)<br />

Collection round nonhousehold<br />

waste 0.6% 0%<br />

Applying <strong>the</strong>se percentages <strong>to</strong> <strong>the</strong> most recent overall <strong>to</strong>nnages for MSW in <strong>the</strong> English Regions, Wales,<br />

Nor<strong>the</strong>rn Ireland and Scotland <strong>to</strong> provide an estimate for <strong>the</strong> waste wood arising in <strong>to</strong>nnes (and where<br />

possible values for English regions) yielded <strong>the</strong> following results: 114<br />

Table 34 Estimate of wood content of MSW in <strong>the</strong> UK for 2003/4, excluding furniture<br />

Wood Arisings (‘000 <strong>to</strong>nnes)<br />

Waste Stream England Nor<strong>the</strong>rn<br />

Ireland<br />

Scotland Wales UK<br />

Household Collection 356 12 38 12 418 (39%)<br />

Bulky Collections 37 1 7 2 47 (4%)<br />

Civic Amenity 498 23 37 13 572 (54%)<br />

Non Household Collection 22 0 3 2 27 (3%)<br />

Total Wood in MSW 913 37 85 29 1,065<br />

Clearly <strong>the</strong> dominant source of municipal wood is <strong>the</strong> Civic Amenity Sites, which in 2003/4 accounted for<br />

over half of <strong>the</strong> arisings, due <strong>to</strong> <strong>the</strong> presence of garden waste at CA sites.<br />

Furniture in Municipal Waste<br />

It has not been possible <strong>to</strong> identify a suitable percentage for wood composition for furniture in <strong>the</strong> MSW<br />

waste stream. The figures below also include coverings, surface treatments and glass.<br />

114 More up <strong>to</strong> date data is of MSW arising is available, however not in <strong>the</strong> detailed waste streams within MSW required for <strong>the</strong> calculation here.<br />

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Table 35 Estimate of furniture waste in MSW in <strong>the</strong> UK for 2003/4<br />

Wood Arisings (‘000 <strong>to</strong>nnes)<br />

Waste Stream England Nor<strong>the</strong>rn<br />

Ireland<br />

Scotland Wales UK<br />

Household Collection 34 1.1 3.6 0.7 39 (6%)<br />

Bulky Collections 230 6.9 43 11.5 291 (49%)<br />

Civic Amenity 236 11.1 17.7 6.1 271 (45%)<br />

Non Household Collection 0 0 0 0 0<br />

Total Wood in MSW 500 19 64 18 602<br />

Applying <strong>the</strong> waste wood arisings for 2003/4 <strong>to</strong> <strong>the</strong> waste arisings for that year (England, 29,114<br />

thousand <strong>to</strong>nnes) yields an arising figure of 3.13% for general waste wood and 1.72 for waste furniture<br />

wood. 115 These percentages have been applied <strong>to</strong> <strong>the</strong> most recent MSW arisings <strong>to</strong> give an alternative<br />

arisings figure, and yield <strong>the</strong> estimates in Table 36.<br />

Table 36 Estimation of Waste Wood arisings <strong>by</strong> region using 2007/-8 MSW figures<br />

Region Wood Waste (excl.<br />

furniture)<br />

(‘000 <strong>to</strong>nnes)<br />

Furniture Waste<br />

(‘000 <strong>to</strong>nnes)<br />

East Midlands 76 42<br />

East of England 95 52<br />

London 130 71<br />

North East 47 49<br />

North West 127 70<br />

South East 143 79<br />

South West 92 50<br />

West Midlands 93 51<br />

Yorkshire and Humber 90 49<br />

England - Total 892 513<br />

Nor<strong>the</strong>rn Ireland 34 19<br />

Scotland 94 52<br />

Wales 56 31<br />

UK - Total 1,076 584<br />

5.1.2 Construction and Demolition Waste Wood (C&D)<br />

Data for C&D waste is largely concerned with achieving aggregate recycling, and <strong>the</strong>refore includes only<br />

mineral waste. The Environment Agency estimate that 4 million <strong>to</strong>nnes of waste wood arise from <strong>the</strong><br />

construction industry every year. 116 Construction and demolition waste is usually classed as one<br />

category, but waste wood may arise from a number of different waste streams: 117<br />

• Construction<br />

o off-cuts from structural timbers,<br />

o timber packaging, scaffolding, cladding, etc.<br />

Wood is likely <strong>to</strong> be untreated or uncontaminated.<br />

115 Defra e-Digest Statistics for 2007/8, http://www.defra.gov.uk/environment/statistics/wastats/archive/mwb200708.xls<br />

116 Defra “Waste Wood for Biomass” quoting <strong>the</strong> study <strong>by</strong> Nikita et al (2005). They note that this figure is an average of <strong>the</strong> maximum and minimum<br />

estimates which are 7.9 million tpa and 2.2 million tpa respectively for <strong>the</strong> UK.<br />

117 Remade Scotland (2004) Woodwaste Arisings in Scotland Assessment of Available Data on Scottish


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• Demolition<br />

o Used structural timber, floorboards, joists, doors and frames etc.<br />

Wood is likely <strong>to</strong> be treated, painted, coated or varnished, all are ‘contaminated’.<br />

• Refurbishment - this would be a combination of <strong>the</strong> above<br />

• Destruction<br />

• Scaffolding<br />

Remade Scotland indicates that <strong>the</strong> specific types of waste wood from construction and demolition waste<br />

include:<br />

• cable drums<br />

• coated material<br />

• cladding<br />

• dimension timber<br />

• doors and door<br />

frames<br />

• fences<br />

• flooring<br />

• framing timbers<br />

• pallets and fencing<br />

• panels and engineered<br />

wood composites using<br />

adhesives<br />

• piles<br />

• poles<br />

• solid wood<br />

• stakes<br />

• window frames<br />

Traditionally much of this waste was disposed of in skips on site and was poorly segregated. However,<br />

<strong>the</strong>re have been advances in segregation and recycling of construction and demolition waste through <strong>the</strong><br />

introduction of <strong>the</strong> Site Waste Management Plans (SWMP) in April 2008 for sites greater than<br />

£300,000. 118 Small sites (under £300,000) still continue <strong>to</strong> skip <strong>the</strong> majority of <strong>the</strong>ir waste, most of which<br />

goes <strong>to</strong> landfill. Segregation is often more difficult on such sites due <strong>to</strong> <strong>the</strong> lack of time and resource <strong>to</strong><br />

undertake this activity.<br />

Current Arisings<br />

There are only a few data sets available for arisings of waste wood from C&D, and <strong>the</strong>se have been<br />

evaluated <strong>by</strong> Nikitas et al (2005). (See Appendix 1 for an evaluation of <strong>the</strong>se sources.)<br />

Taking 1.5% as <strong>the</strong> minimum value of C&D waste arisings that are waste wood, and assuming a<br />

maximum value of 12.44% as <strong>the</strong> upper limit (although this includes excavation waste, hence <strong>the</strong><br />

reduction <strong>to</strong> 7.22% as 42% of <strong>the</strong> C&D waste was established as excavation waste) produces <strong>the</strong> figures<br />

detailed in Table 37.<br />

Table 37 Estimated waste wood arisings (excluding reclaimed wood) from <strong>the</strong> C&D waste stream.<br />

UK Arisings of waste wood<br />

(‘000 <strong>to</strong>nnes)<br />

England Wales Scotland Nor<strong>the</strong>rn<br />

Ireland<br />

Total C&D waste arisings 88,900 5,000 6,300 900 101,100<br />

Minimum Estimate (1.5%) 1,330 80 90 140 1,640<br />

Maximum Estimate (7.22%) 6,410 360 450 70 7,290<br />

Average 3,870 220 270 40 4,400<br />

The above figures take no account of reclaimed wood, which is a fur<strong>the</strong>r 634,000 <strong>to</strong>nnes for <strong>the</strong> UK,<br />

yielding a <strong>to</strong>tal of 5,034,000 <strong>to</strong>nnes. However it is unlikely that reclaimed wood would be available for<br />

energy generation. There is a very significant difference between <strong>the</strong> minimum and maximum estimates,<br />

demonstrating <strong>the</strong> degree of uncertainty in <strong>the</strong> data, and <strong>the</strong> need for more detailed arisings figures <strong>to</strong> be<br />

generated.<br />

118 Defra 2008. Non-statu<strong>to</strong>ry guidance for site waste management plans.<br />

UK<br />

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5.1.3 Commercial and Industrial Waste Wood (C&I)<br />

The main sources of wood waste originating within <strong>the</strong> C&I waste stream are off cuts and wastes from:<br />

• Furniture manufacture<br />

• Manufacture of products for use in construction e.g. roofing timbers, joists, floorboards, doors and<br />

windows<br />

• Wood waste during manufacture of wooden packaging<br />

• Wood wastes from waste wooden packaging<br />

• Utility poles<br />

• Railway sleepers.<br />

A number of surveys have been conducted on specific industries within <strong>the</strong> C&I waste stream <strong>by</strong><br />

organisations such as <strong>the</strong> Environment Agency, British Furniture manufacturers (BFM), FIET, FIRA and<br />

TRADA. These data sources have been assessed <strong>by</strong> Nikitas et al (2005) and, in general, were rated as<br />

being of poor quality.<br />

The <strong>to</strong>tal C&I waste wood arisings were estimated <strong>to</strong> be 4,481,000 <strong>to</strong>nnes. General waste wood arisings<br />

were identified as <strong>the</strong> largest source of arisings, with <strong>the</strong> second largest contribution from panel board<br />

manufacture (which accounts for a quarter of all wood wastes arising from <strong>the</strong> C&I sec<strong>to</strong>r, but it is<br />

believed that much of this figure is consumed within <strong>the</strong> industry <strong>to</strong> generate process heat).<br />

25%<br />

12%<br />

1% 1%<br />

4% 1%<br />

56%<br />

O<strong>the</strong>r C&I w ood w aste<br />

Railw ay Sleepers<br />

Utility Poles<br />

Furniture Manufacture<br />

Panelboard Manufacture<br />

Construction Industry<br />

Product Manufacture<br />

Wooden Packaging<br />

Manufacture<br />

Figure 13 Waste wood arisings for C&I type activities<br />

Future Arisings for all waste streams<br />

The WRAP <strong>report</strong> <strong>by</strong> Nikitas et al (2005) is also <strong>the</strong> best source of predictions of future arisings of waste<br />

wood. A simple model forecast for <strong>the</strong> various waste streams up until 2015 was generated and <strong>the</strong><br />

results shown in<br />

Table 38 shows estimations for <strong>the</strong> future waste wood arisings , taking in<strong>to</strong> account <strong>the</strong> relevant<br />

legislations and targets such as <strong>the</strong> Landfill Directive, <strong>the</strong> Packaging Directive, <strong>the</strong> Landfill Tax and <strong>the</strong><br />

Aggregates Levy.


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Table 38 Estimations of future Waste wood arisings from various waste streams.<br />

Year<br />

MSW arisings<br />

(‘000 <strong>to</strong>nnes,<br />

no furniture)<br />

MSW furniture<br />

(‘000 <strong>to</strong>nnes)<br />

C&D<br />

(‘000 <strong>to</strong>nnes)<br />

C&I<br />

(‘000 <strong>to</strong>nnes)<br />

2008 1,147 648 5167 6,612<br />

2012 1,217 688 5271 6,678<br />

2015 1,273 719 5351 6,729<br />

Conclusions<br />

The UK produces a large quantity of waste wood, arising from a variety of waste streams. The specific<br />

data quality is largely poor. Overall it is estimated that over 7.5 million <strong>to</strong>nnes of waste wood are<br />

generated each year. The limiting fac<strong>to</strong>rs for <strong>the</strong> use of waste wood are <strong>the</strong> presence of any<br />

contaminants and <strong>the</strong> difficulty in sorting and segregating mixed waste streams <strong>to</strong> provide wood in <strong>the</strong><br />

form and quantity required. Most, if not all, of this wood will have been treated in some way, so if it is <strong>to</strong><br />

be used for energy or fuels this must be done in a WID compliant facility.<br />

In addition <strong>the</strong>re are alternative existing markets for wood waste. These include:<br />

• Use in panel board manufacture<br />

• Use <strong>to</strong> make horticultural surface products<br />

• Use <strong>to</strong> make animal bedding<br />

• Combustion in small scale wood burning boilers<br />

• Incineration with or without <strong>the</strong> recovery of energy<br />

Any large-scale effort <strong>to</strong> encourage <strong>the</strong> use of waste wood for energy or fuels generation will need <strong>to</strong> take<br />

<strong>the</strong>se established uses in<strong>to</strong> account.<br />

The wood recycling industry has significantly increased in size since 1996, when less than 200,000<br />

<strong>to</strong>nnes of waste wood was recycled. All of <strong>the</strong> companies conducting ei<strong>the</strong>r wood waste collection or<br />

sorting of <strong>the</strong> collected wood <strong>to</strong> produce products suitable for recycling are private sec<strong>to</strong>r companies.<br />

The amount of wood which was recycled in 2008 was 2.0 million <strong>to</strong>nnes, of which 1.1 million <strong>to</strong>nnes was<br />

used in panel board manufacture and 0.4 million <strong>to</strong>nnes was sent <strong>to</strong> biomass energy recovery facilities.<br />

5.2 Food Waste<br />

Background<br />

This section contains waste arising data for food waste, which has been split in<strong>to</strong> food waste arisings<br />

from households and food waste arisings from <strong>the</strong> commercial and industrial sec<strong>to</strong>r. For each of <strong>the</strong>se<br />

two sec<strong>to</strong>rs data is provided for England, Wales, Scotland and Nor<strong>the</strong>rn Ireland.<br />

Food waste amounts <strong>to</strong> 18-20 million <strong>to</strong>nnes each year, for which 6.7 million <strong>to</strong>nnes is discarded from UK<br />

households. The commercial and industrial sec<strong>to</strong>r contribute 1.6 million <strong>to</strong>nnes from retailers, 4.1 million<br />

<strong>to</strong>nnes from food manufacturers and 3 million <strong>to</strong>nnes from food service and restaurants. 119<br />

The proportion of food waste currently captured is low across <strong>the</strong> UK, most is sent <strong>to</strong> landfill.<br />

Correspondingly <strong>the</strong>re is scope for fur<strong>the</strong>r collection and utilisation of food waste. 120 Indeed, <strong>the</strong> Landfill<br />

Directive requires increasing collection up <strong>to</strong> 2020. Such waste could potentially be converted in<strong>to</strong><br />

compost, anaerobically digested and <strong>the</strong> gas collected, or, more exceptionally, <strong>the</strong>rmally treated.<br />

119 Non-Household Food Waste, WRAP, http://www.wrap.org.uk/retail/food_waste/nonhousehold_food.html<br />

120 Hogg. D, Barth. J, Schleiss. K, and Favoino. E , 2007, Dealing with Food Waste In <strong>the</strong> UK, Eunomia Research and Consulting for WRAP.<br />

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Future Arisings<br />

Predictions of future food waste arisings are difficult <strong>to</strong> make due <strong>to</strong> <strong>the</strong> significant amount of pressure<br />

and campaigns in operation at <strong>the</strong> moment, such as some councils collecting segregated food waste, and<br />

<strong>the</strong> WRAP ‘Love Food, Hate Waste’ campaign. However such campaigns generally take 5 years <strong>to</strong> have<br />

an impact, so <strong>the</strong> likelihood is that any decrease in arisings will be small over <strong>the</strong> next few years.<br />

5.2.1 Household Food Waste<br />

Household waste is a sub-section of Municipal Solid Waste (MSW). This waste is almost exclusively<br />

household food waste, but may contain a minor amount of commercial and industrial waste included<br />

where refuse collections include mixed domestic and commercial properties.<br />

Typical composition figures for MSW have been used <strong>to</strong> provide an estimate of food waste arisings. The<br />

<strong>report</strong> ‘Dealing with Food Wastes in <strong>the</strong> UK’ published in March 2007 quantified <strong>the</strong> amount of food waste<br />

from households, and have been used here <strong>to</strong> calculate regional food waste arisings. 120<br />

England<br />

• Data from Defra’s 2007/08 MSW figures (WRAP <strong>report</strong> used 2004/05 data).<br />

• Food waste composition level: 17.5%<br />

Nor<strong>the</strong>rn Ireland<br />

• Data from 2007/2008. 121<br />

• Food waste composition level: 19%.<br />

Scotland<br />

• Most recent data from SEPA’s 2006/2007. 122<br />

• Food waste composition level: 18%.<br />

Wales<br />

• Data from 2007/2008. 123<br />

• Food waste composition level: 18%.<br />

It is worth noting that <strong>the</strong> levels of food waste predicted above is in line with <strong>the</strong> numbers <strong>the</strong> Welsh<br />

Assembly Government (WAG) is releasing, but <strong>the</strong> local authorities in Wales are finding <strong>the</strong>se quantities<br />

are over-estimated, as cautioned against in <strong>the</strong> background section above. Estimations of food waste are<br />

shown in Table 39 below.<br />

121 Municipal waste Management Report – Nor<strong>the</strong>rn Ireland 2007/08, http://www.ni-environment.gov.uk/waste/municipal_data_<strong>report</strong>ing.htm<br />

122 Waste Data Digest 8 Data Tables (2006/07) http://www.sepa.org.uk/waste/waste_data/waste_data_digest.aspx<br />

123 Municipal Waste Management Report 2007/08, http://new.wales.gov.uk/statsdocs/env/sdr177-2008.pdf


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Table 39 Food waste from households <strong>by</strong> region (2007/08) using <strong>the</strong> appropriate composition level.<br />

Region Quantity of<br />

Household waste<br />

(‘000 <strong>to</strong>nnes)<br />

Quantity of Food<br />

Waste<br />

(‘000 <strong>to</strong>nnes)<br />

East Midlands 2,185 382<br />

East of England 2,841 497<br />

London 3,342 585<br />

North East 1,268 222<br />

North West 3,599 630<br />

South East 4,242 742<br />

South West 2,644 463<br />

West Midlands 2,662 466<br />

Yorkshire/Humber 2,504 438<br />

England - Total 25,287 4,425<br />

Nor<strong>the</strong>rn Ireland 928 176<br />

Scotland 2,995 539<br />

Wales 1,542 277<br />

UK – Total 30,752 5,417<br />

5.2.2 Industrial and Commercial Food Waste<br />

The Waste Strategy 2007 defines commercial and industrial waste as follows: 124<br />

• commercial waste: waste arising from wholesalers, catering establishments, shops and offices<br />

(in both <strong>the</strong> public and private sec<strong>to</strong>rs)<br />

• industrial waste: waste arising from fac<strong>to</strong>ries and industrial plants.<br />

The data for food waste arisings from commercial and industrial waste sources is limited and it has not<br />

been possible <strong>to</strong> provide a breakdown of food waste arisings from commercial and industrial sources<br />

across <strong>the</strong> different regions of each country. The analysis below focuses on <strong>the</strong> food waste element in<br />

<strong>the</strong> mixed waste streams, <strong>to</strong>ge<strong>the</strong>r with kitchen and canteen waste, where it has been identified<br />

separately.<br />

England & Wales<br />

In 2002/03 <strong>the</strong> Environment Agency under<strong>to</strong>ok a survey of Commercial and Industrial business across<br />

England and Wales, which ga<strong>the</strong>red data on <strong>the</strong> types and quantities of waste, of which food waste was<br />

one, and <strong>the</strong> disposal or recovery methods. 125 Although this data is now relatively old, <strong>the</strong> survey has not<br />

been repeated for England, and a new survey is currently underway in Wales, but not yet published.<br />

Scotland<br />

In November 2008 a <strong>report</strong> <strong>by</strong> Napier University in<strong>to</strong> Scotland’s Commercial and Industrial waste was<br />

published, which estimated that <strong>the</strong>re are 2.73 million <strong>to</strong>nnes of mixed waste (similar <strong>to</strong> household waste)<br />

from commercial and industrial sources of which 16.7% was food waste. 126<br />

Whilst o<strong>the</strong>r data and information is available regarding Commercial and Industrial waste in Scotland, <strong>the</strong><br />

focus of <strong>the</strong>se is often across business sec<strong>to</strong>rs, for example in <strong>the</strong> Waste Data Digest. This means that<br />

<strong>the</strong> necessary level of detail <strong>to</strong> provide a realistic estimate of overall food waste arisings is not possible. In<br />

124 Waste Strategy for England, Defra, http://www.defra.gov.uk/ENVIRONMENT/waste/strategy/<br />

125 Environment Agency, National Waste Production Survey 2002<br />

126 McLaurin. L, Dar<strong>by</strong>. P, and Raeside, R. (2008) Estimation of commercial and industrial waste produced in Scotland in 2006. Final <strong>report</strong> <strong>to</strong> <strong>the</strong><br />

Scottish Environment Protection Agency (SEPA). Centre for Statistics, Napier University.<br />

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comparison <strong>the</strong> Napier University Report provides an indication of <strong>the</strong> different waste streams within <strong>the</strong><br />

commercial and industrial sec<strong>to</strong>r and also includes compositional analysis for <strong>the</strong> mixed waste.<br />

Table 40 Industrial and Commercial Food Waste for England, Wales and Scotland<br />

Country Commercial Industrial<br />

Total<br />

(‘000 <strong>to</strong>nnes) (‘000 <strong>to</strong>nnes) (‘000 <strong>to</strong>nnes)<br />

England 127 6,067 4,121 6,189<br />

Wales 125 211 51 262<br />

Scotland 126 - - 457<br />

Note: Totals do not calculate correctly due <strong>to</strong> rounding<br />

O<strong>the</strong>r studies<br />

O<strong>the</strong>r studies have been undertaken, which focus and specific geographical areas or industry sec<strong>to</strong>rs.<br />

While reference <strong>to</strong> <strong>the</strong>se is not helpful in providing an overview for each country, <strong>the</strong>se <strong>report</strong>s would be<br />

able <strong>to</strong> provide a more detailed picture for specific areas.<br />

• Research undertaken for Defra and <strong>the</strong> Food and Drink Federation (FDF) provides a snapshot of<br />

food waste arisings across FDF members in 2006. 128 It was conducted at 236 sites, <strong>by</strong><br />

organisations with a combined turnover of £17bn. 129 The survey included data on packaging<br />

waste, mixed waste and food waste – shown in Table 41. Fur<strong>the</strong>r food waste arising will be in <strong>the</strong><br />

mixed food and packaging waste, however <strong>the</strong> composition of this waste stream was not<br />

considered <strong>by</strong> <strong>the</strong> study.<br />

Table 41 Unmixed food waste arisings from FDF members in 2006<br />

Country / RDA Food Waste<br />

(‘000 <strong>to</strong>nnes)<br />

Advantage West Midlands 205<br />

SWRDA 111<br />

London 23<br />

EMDA 98<br />

Yorkshire Forward 47<br />

EEDA 27<br />

SEEDA 23<br />

NWDA 25<br />

One North East 13<br />

England - Total 571<br />

Nor<strong>the</strong>rn Ireland 3<br />

Scotland 13<br />

Wales 18<br />

UK - Total 605<br />

• A study was conducted for <strong>the</strong> East of England Regional Assembly area, and published in May<br />

2008. 130 The study considered both green waste and food waste arisings, with a particular focus<br />

on <strong>the</strong> latter. It examined <strong>the</strong> future requirements for an increased number of facilities <strong>to</strong> treat<br />

separately collected bio-wastes from municipal and commercial and industrial waste streams. It<br />

considered waste arisings, availability, current treatment capacity and its spatial distribution,<br />

127 http://www.defra.gov.uk/environment/statistics/waste/wrindustry.htm<br />

128 http://www.fdf.org.uk/ - FDF members cover a third of <strong>the</strong> turnover for <strong>the</strong> food and drink sec<strong>to</strong>r.<br />

129 http://www.fdf.org.uk/publicgeneral/mapping_waste_in_<strong>the</strong>_food_industry.pdf<br />

130 Summary Report Regional Biowastes management Study:<br />

http://www.eera.gov.uk/GetAsset.aspx?id=fAAzADMANwB8AHwARgBhAGwAcwBlAHwAfAAwAHwA0


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technologies available, <strong>the</strong> current treatment technology gap, assumed waste growth and growth<br />

in <strong>the</strong> capture of bio-wastes. This study provides a detailed analysis of <strong>the</strong> Regional position,<br />

however many regions have not undertaken such studies, and whe<strong>the</strong>r <strong>the</strong>y do so in <strong>the</strong> future<br />

will depend on <strong>the</strong> regional priorities.<br />

Conclusion<br />

The UK produces significant amounts of food waste, <strong>the</strong> potential value of which is only just being<br />

realised. While MSW food waste arisings are considerable, estimated <strong>to</strong> be 5.4 million <strong>to</strong>nnes,<br />

Commercial and Industrial food waste arisings are estimated <strong>to</strong> be even higher at 6.9 million <strong>to</strong>nnes per<br />

annum.<br />

WRAP, whose recent campaign ‘Love food, hate waste’ focused on household food waste, have<br />

identified that when food waste collection schemes are set up <strong>the</strong> volume collected is often significantly<br />

less than that anticipated – believed <strong>to</strong> be due <strong>to</strong> people reducing <strong>the</strong>ir food waste once <strong>the</strong>y can see how<br />

much is being wasted.<br />

5.3 Tallow 131<br />

Background<br />

Tallow is an animal fat obtained <strong>by</strong> rendering animal carcases and waste from <strong>the</strong> food industry and as<br />

such its arisings would be considered under industrial waste arisings. Rendering is <strong>the</strong> process <strong>by</strong> which<br />

animal carcases and trimmings are crushed and heated <strong>to</strong> drive off <strong>the</strong> water, sterilise <strong>the</strong> material and<br />

allow <strong>the</strong> fats (tallow) and meat and bone meal (MBM) <strong>to</strong> be separated. Rendering is an energy intensive<br />

process and <strong>the</strong> industry has traditionally used some of <strong>the</strong> tallow it produces as fuel.<br />

Current Arisings<br />

The size of <strong>the</strong> UK tallow arisings is dependent on UK meat production, which effectively limits <strong>the</strong> tallow<br />

available <strong>to</strong> <strong>the</strong> UK <strong>to</strong> around 250,000 <strong>to</strong>nnes per annum, from 2 million <strong>to</strong>nnes of animal waste. The<br />

industry processes <strong>the</strong> <strong>by</strong>-products of approximately 2 million cattle, 10 million pigs, 14 million sheep and<br />

800 million chickens annually. The amount of tallow produced in <strong>the</strong> UK has been stable for a number of<br />

years, and is unlikely <strong>to</strong> change significantly in <strong>the</strong> foreseeable future.<br />

Estimates of <strong>the</strong> amount of tallow produced range from 200kT per annum <strong>to</strong> 290kT per annum depending<br />

on <strong>the</strong> definition of what is included and <strong>the</strong> reference year. 132 The consensus is that 220 – 240 kT is<br />

available in principle for industrial use.<br />

Currently all tallow produced is used for some economic purpose. None is disposed <strong>to</strong> landfill. The main<br />

uses are dictated <strong>by</strong> <strong>the</strong> category of tallow under <strong>the</strong> Animal By-products Regulations: 133<br />

Category 1 can only be used for burning or fuel production<br />

Category 2 can be used for industrial applications<br />

Category 3 can be used for human contact (e.g. in soaps and cosmetics).<br />

This influences <strong>the</strong> current uses: burning of (mainly category 1) tallow in boilers <strong>by</strong> <strong>the</strong> rendering industry<br />

<strong>to</strong> raise process heat and <strong>the</strong> use of category 2 and 3 tallow <strong>by</strong> <strong>the</strong> oleochemicals and soap industry. A<br />

breakdown of <strong>the</strong>se uses is shown in Figure 14 (Uniqema 2008), demonstrating that 43% of <strong>the</strong> tallow is<br />

used as a fuel source, and 33% for industrial applications. These figures exclude exports.<br />

131 Advice on <strong>the</strong> Economic and Environmental Impacts of Government Support for Biodiesel Production from Tallow, Report for <strong>the</strong> Department of<br />

Transport, 2008.<br />

132 Argent Energy, 2008; CIA2008; UKRA 2008; Uniqema 2008.<br />

133 See Chapter 2 for an explanation of <strong>the</strong>se terminologies.<br />

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Burning<br />

33%<br />

Pow er Generation<br />

3%<br />

Biodiesel<br />

7%<br />

Food<br />

8%<br />

Animal Feed<br />

16%<br />

Oleochemicals and<br />

soap<br />

33%<br />

Figure 14 Uses of tallow in <strong>the</strong> UK (kT p.a.)<br />

This is a ra<strong>the</strong>r different balance than found when considering <strong>the</strong> EU as a whole, where a much greater<br />

portion of <strong>the</strong> available tallow goes in<strong>to</strong> animal feed. 134<br />

Energy and Fuels from Tallow<br />

The end uses for tallow are changing, as <strong>the</strong> incentives for <strong>the</strong> production of biodiesel have made this<br />

feeds<strong>to</strong>ck attractive for fuel production. With a fixed amount of tallow available on <strong>the</strong> market, this can<br />

only be obtained <strong>by</strong> diverting tallow from existing applications such as burning or oleochemical and soap<br />

production.<br />

Tallow derived biodiesel is an established procedure. In <strong>the</strong> UK tallow bio-diesel is produced through <strong>the</strong><br />

FAME processes <strong>by</strong> Argent Energy in Mo<strong>the</strong>rwell at <strong>the</strong>ir 45 kT per annum capacity site (supplied with<br />

both tallow and used cooking oil). Their Ellesmere Port plant is currently under construction with a future<br />

capacity of 150 kT. 135<br />

Tallow biodiesel has a higher cetane number than plant oil biodiesel, resulting in cleaner and more<br />

efficient burning in diesel engines. However, it also has a higher cloud point because of <strong>the</strong> high levels of<br />

saturated fatty acids. This means that tallow biodiesel tends <strong>to</strong> crystallise out at low temperatures<br />

creating problems in engines. Used neat (100%) tallow biodiesel would not meet <strong>the</strong> European standard<br />

for biodiesel. However, when blended at low percentages in<strong>to</strong> conventional diesel <strong>the</strong> mixture meets<br />

relevant fuel quality standards.<br />

Conclusion<br />

Tallow is a long established <strong>by</strong>-product of <strong>the</strong> rendering process, with constant volumes produced in <strong>the</strong><br />

UK. Currently all tallow is used for some commercial purpose – traditionally high quality tallow was used<br />

in <strong>the</strong> chemicals and cosmetics industries, while low grade tallow was burnt for heat. The introduction of<br />

tallow for bio-diesel has al<strong>read</strong>y had a disruptive effect on traditional markets.<br />

134 EFPRA 2008, http://www.efpra.eu/content/default.asp?PageID=21<br />

135 Argent Energy 2008, http://www.argentenergy.com/articles/news/article_51.shtml


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5.4 Textiles Waste Arising<br />

Background<br />

It is estimated that more than 1 million <strong>to</strong>nnes of textiles are thrown away every year, most of which is<br />

post-consumer waste. At least 50% of <strong>the</strong> textiles that are thrown away are recyclable. However, <strong>the</strong><br />

proportion of textile wastes reused or recycled annually in <strong>the</strong> UK is only around 25%. 136 Besides postconsumer<br />

waste, post-industrial waste arises during yarn and fabric manufacture, <strong>the</strong> garment-making<br />

processes and from <strong>the</strong> retail industry. Textile waste arises as standard in two waste streams: MSW and<br />

C&I.<br />

Current Arisings<br />

Several sources have identified <strong>the</strong> proportion of textile waste in MSW as approximately 1.9%. 137<br />

Meanwhile C&I textile arisings are estimated <strong>to</strong> be 1-2% of <strong>the</strong> waste stream in Section 4.2.<br />

Table 42 Estimated textile waste arising in <strong>the</strong> UK <strong>by</strong> region in (‘000 <strong>to</strong>nnes)<br />

Region Textiles<br />

Textiles Total<br />

(1.9% of MSW) (1.5% of C&I)<br />

East Midlands 46 121 167<br />

East of England 58 98 156<br />

London 79 113 191<br />

North East 29 69 98<br />

North West 77 125 202<br />

South East 87 133 219<br />

South West 56 83 139<br />

West Midlands 57 109 166<br />

Yorkshire and Humber 54 167 221<br />

England - Total 542 1019 1560<br />

Nor<strong>the</strong>rn Ireland 20 24 44<br />

Scotland 65 80 145<br />

Wales 34 117 151<br />

UK - Total 661 1239 1900<br />

Current Disposal Methods<br />

At present, <strong>the</strong> majority of post-consumer textiles are collected <strong>by</strong> charities such as The Salvation Army,<br />

Scope and Oxfam. Such collec<strong>to</strong>rs sort <strong>the</strong> material, selling it on <strong>to</strong> merchants in <strong>the</strong> appropriate sec<strong>to</strong>rs.<br />

The Open University Household Waste Study shows that <strong>the</strong>re has been a year on year increase in <strong>the</strong><br />

proportion of households served <strong>by</strong> kerbside recycling collections for textiles: 16.8% in 2002, 29% in 2005<br />

and 44.7% in 2008.<br />

Some post-industrial waste is recycled as part of in-house procedures. This is more common in <strong>the</strong> yarn<br />

and fabric-manufacturing sec<strong>to</strong>rs. The rest, aside from going <strong>to</strong> landfill or incineration, is sold <strong>to</strong><br />

merchants via textile reclamation fac<strong>to</strong>ries that can handle a huge <strong>to</strong>nnage of textiles. The main routes for<br />

<strong>the</strong> material are:<br />

• High quality second hand clo<strong>the</strong>s and shoes are resorted for sending <strong>to</strong> charities in <strong>the</strong> UK<br />

and use in developing countries.<br />

• Lower quality textiles which are worn out are processed within <strong>the</strong> fac<strong>to</strong>ry <strong>to</strong> produce<br />

industrial wiping cloths.<br />

136 Textile recycling information sheet, Waste Online, http://www.wasteonline.org.uk/resources/InformationSheets/Textiles.htm, Analysis of household<br />

waste composition and fac<strong>to</strong>rs driving waste increases - Dr. J. Parfitt, WRAP, December 2002.<br />

137 Open University Household Waste Study, <strong>Jones</strong>, A., Nesaratnam, S., Porteous, A., 2008, Defra: 1.9%, National Household Waste Arising Survey:<br />

1.8% after recycling<br />

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• O<strong>the</strong>r textiles are fur<strong>the</strong>r graded for fibre reclamation <strong>by</strong> pulling <strong>the</strong> th<strong>read</strong>s of <strong>the</strong> textile and<br />

using it <strong>to</strong> produce new clo<strong>the</strong>s and blankets, and also mattresses.<br />

Textiles have an average GCV of 16MJ/kg and <strong>the</strong> stream is <strong>the</strong>refore viable for Energy from Waste<br />

projects. However due <strong>to</strong> <strong>the</strong> al<strong>read</strong>y existing market in recycling and <strong>the</strong> complexity involved in sorting<br />

MSW it could be difficult <strong>to</strong> utilise this as a separate feeds<strong>to</strong>ck.<br />

Textile waste is considered <strong>to</strong> be a high priority product within Defra’s Product Roadmap scheme due <strong>to</strong><br />

<strong>the</strong> high environmental and social impact - accounting for 5-10% of UK environmental impacts, partly due<br />

<strong>to</strong> <strong>the</strong> UK’s high consumption of clothing. 138,139<br />

Future Arisings<br />

A simple forecast for textile waste arising can be modelled on <strong>the</strong> assumption that <strong>the</strong> proportion of textile<br />

in C&I waste and MSW remain constant applied <strong>to</strong> <strong>the</strong> MSW and C&I waste forecasts. Such a prediction<br />

suggests that for <strong>the</strong> UK <strong>the</strong> <strong>to</strong>tal textile arisings will be 1,944,000 <strong>to</strong>nnes in 2010, rising <strong>to</strong> 2,042,000<br />

<strong>to</strong>nnes <strong>by</strong> 2020.<br />

Conclusion<br />

Textile wastes, estimated <strong>to</strong> be nearly 2 million <strong>to</strong>nnes from both MSW and C&I waste streams, are a<br />

waste stream where significant environmental benefits can be delivered through simple reuse. Only<br />

when textiles are very badly damaged or soiled does energy recovery and similar solutions become<br />

advisable.<br />

5.5 Paper Waste Arisings<br />

Background<br />

The UK consumes between 12 and 13 million <strong>to</strong>nnes of paper and board each year. 140 The main sources<br />

of waste paper and board arisings are from households (MSW) and from <strong>the</strong> Commercial and Industrial<br />

(C&I) waste stream. The paper/card waste arising from <strong>the</strong> Construction and Demolition (C&D) sec<strong>to</strong>r is<br />

considered <strong>to</strong> be negligible (any arisings would be from packaging used for construction materials).<br />

Municipal Solid Waste Arising<br />

Paper and cardboard is estimated <strong>to</strong> be 21% of <strong>the</strong> <strong>to</strong>tal arisings of MSW. 141 Such an estimation leads <strong>to</strong><br />

<strong>the</strong> arisings from <strong>the</strong> MSW figures for 2007/08 in Table 43 142<br />

138 EU Commission, Environmental Impact of Products, http://ec.europa.eu/environment/ipp/pdf/eipro_<strong>report</strong>.pdf<br />

139 Defra, 2008, Product roadmaps- Clothing, http://www.defra.gov.uk/environment/consumerprod/products/clothing.htm<br />

140 http://www.paper.org.uk/information/pages/statistics.html<br />

141 The Composition of Municipal Solid Waste in Wales. Report <strong>by</strong> AEA for <strong>the</strong> Welsh Assembly Government, December 2003<br />

142 e-Digest Statistics about: Waste and Recycling, Defra, 2008, http://www.defra.gov.uk/environment/statistics/waste/index.htm Waste Data Digest 8:<br />

Key facts and trends. SEPA, 2008, http://www.sepa.org.uk/waste/waste_data_menu/waste_data_digest.aspx, Welsh Assembly Government, 2008;<br />

Municipal Waste Management Report for Wales 2007-2008; Environment & Heritage Service, Municipal Waste Management Nor<strong>the</strong>rn Ireland 2005/06<br />

Summary Report.


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Table 43 Paper and board waste arising in MSW in <strong>the</strong> UK<br />

Region<br />

Paper and Cardboard<br />

(‘000 <strong>to</strong>nnes)<br />

East Midlands 507<br />

East of England 637<br />

London 871<br />

North East 318<br />

North West 851<br />

South East 958<br />

South West 615<br />

West Midlands 628<br />

Yorkshire and Humber 602<br />

England - Total 5,986<br />

Nor<strong>the</strong>rn Ireland 223<br />

Scotland 722<br />

Wales 378<br />

UK - Total 7,309<br />

5.5.1 Industrial and Commercial Waste Paper<br />

Paper and card are often source separated <strong>by</strong> Industrial and Commercial premises <strong>to</strong> some degree.<br />

Table 44 lists <strong>the</strong> sec<strong>to</strong>rs that produce <strong>the</strong> most paper and board waste. 143 The publishing, printing and<br />

recording sec<strong>to</strong>r produces <strong>the</strong> most paper and card from <strong>the</strong> industrial sec<strong>to</strong>r, but <strong>the</strong> <strong>to</strong>tal arisings of<br />

separately identified paper and card from <strong>the</strong> commercial sec<strong>to</strong>r are over twice those from <strong>the</strong> industrial<br />

sec<strong>to</strong>r. The <strong>to</strong>tal arisings of separately identified paper and cardboard in C&I waste are 8.6 million<br />

<strong>to</strong>nnes.<br />

143 Defra 2006, Industrial and commercial waste arisings <strong>by</strong> business sec<strong>to</strong>r and waste type,<br />

http://www.defra.gov.uk/environment/statistics/waste/index.htm<br />

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Table 44: Paper and board arising as a segregated stream from Industrial and Commercial sec<strong>to</strong>rs, 2006.<br />

Sec<strong>to</strong>r description Paper and<br />

cardboard<br />

(‘000 <strong>to</strong>nnes)<br />

I Food, drink and <strong>to</strong>bacco 262<br />

I Manufacture of pulp, paper and paper products 568<br />

I Publishing, printing and recording 1,331<br />

I Manufacture of chemicals and chemical products; cleaning<br />

159<br />

products, man-made fibres etc; rubber and plastic products<br />

I Manufacture of office machinery, computers, electrical, radio,<br />

television and communication equipment; medical and optical<br />

instruments and clocks<br />

82<br />

Total Industrial 2,656<br />

C Retail - mo<strong>to</strong>r vehicles, parts and fuel; wholesale; o<strong>the</strong>r retail 3,642<br />

C Travel agents, o<strong>the</strong>r business, finance, real estate and<br />

1,183<br />

computer related activities<br />

C Transport, s<strong>to</strong>rage, communications 328<br />

C Social work and public administration 291<br />

C Miscellaneous 201<br />

Total Commercial 5,976<br />

I: Industrial sec<strong>to</strong>r, C: Commercial sec<strong>to</strong>r<br />

The o<strong>the</strong>r source of paper/cardboard is from mixed/general category of C&I waste, approximately 31% of<br />

C&I arisings. This has been found <strong>to</strong> contain approximately 34% paper and card <strong>by</strong> weight, yielding<br />

about 7.1 million <strong>to</strong>nnes. 144 In <strong>to</strong>tal <strong>the</strong> arisings of paper and card in C&I waste is 15.7 million <strong>to</strong>nnes.<br />

This represents 23% <strong>by</strong> weight of <strong>to</strong>tal C&I arisings, and Table 45 gives estimates for <strong>the</strong> corresponding<br />

regional arisings.<br />

Table 45: Paper and board waste arising from C&I.<br />

Region<br />

Paper and Cardboard<br />

(‘000 <strong>to</strong>nnes)<br />

East Midlands 1,510<br />

East of England 1,727<br />

London 1,861<br />

North East 1,058<br />

North West 1,917<br />

South East 2,036<br />

South West 1,278<br />

West Midlands 1,671<br />

Yorkshire and Humber 2,561<br />

England - Total 15,619<br />

Nor<strong>the</strong>rn Ireland 368<br />

Scotland 1,219<br />

Wales 1,794<br />

UK - Total 19,000<br />

144 Determination of <strong>the</strong> Biodegradability of Mixed Industrial and Commercial Waste Landfilled in Wales for <strong>the</strong> Environment Agency, SLR, 2007,<br />

http://www.environment-agency.gov.uk/static/documents/Research/biodegwals_1913611.pdf


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Recycling<br />

Table 46 shows that <strong>the</strong> recycling rate for paper and card has increased from 34% in 1995 <strong>to</strong> 71% in<br />

2007. 145 The UK collected 8.5 million <strong>to</strong>nnes of paper for recycling in 2007, but as it only has capacity <strong>to</strong><br />

produce about 5 million <strong>to</strong>nnes of paper and card products, and thus 4 million <strong>to</strong>nnes of collected material<br />

is exported for recycling. 146<br />

Table 46: Paper and board recycling rates for <strong>the</strong> UK, accounting for imports and exports<br />

Year 1995 2000 2005 2007<br />

Recycling rate (Wt %) 34 41 62 71<br />

Forecast<br />

Assuming that <strong>the</strong>re is no increase in <strong>the</strong> proportion of paper and board arisings in MSW and C&I wastes,<br />

<strong>the</strong>n <strong>the</strong> predictions of general waste increase can be used <strong>to</strong> estimate that MSW paper and board waste<br />

will have risen <strong>to</strong> 7.6 million <strong>to</strong>nnes <strong>by</strong> 2010 and 8.0 million <strong>to</strong>nnes <strong>by</strong> 2020, and C&I paper and board<br />

waste will have risen <strong>to</strong> 19,320,000 <strong>to</strong>nnes in 2010 and 20,240,000 <strong>to</strong>nnes <strong>by</strong> 2020. Total estimated<br />

arisings of paper and cardboard in <strong>the</strong> UK will be about 28.2 million <strong>to</strong>nnes per annum in 2020.<br />

Conclusion<br />

There has been considerable interest in paper and board as a potential feeds<strong>to</strong>ck for <strong>the</strong> generation of<br />

energy. This waste stream is predicted <strong>to</strong> increase over <strong>the</strong> coming years, and as such should be a<br />

stable feeds<strong>to</strong>ck.<br />

5.6 Conclusions<br />

A number of materials are of particular interest for future energy and fuels production. Most are extracted<br />

from bulk, collected waste streams. These are:<br />

• Waste wood extracted from MSW, C&I and C&D waste streams, including all wood packaging<br />

waste. A large proportion of <strong>the</strong> wood will have been treated with a preservative, or similar, and<br />

<strong>the</strong>refore <strong>the</strong> waste must be used in a WID compliant site. Total UK MSW wood waste arisings<br />

are estimated <strong>to</strong> be 1.06 million <strong>to</strong>nnes, based on good quality data, while both C&D and C&I<br />

data sources are of poor quality, but estimations are that C&D arisings were 4.4 million <strong>to</strong>nnes,<br />

and C&I arisings were 4.48 million <strong>to</strong>nnes.<br />

• Food waste is a major waste stream, with a <strong>to</strong>tal of 18-20 million <strong>to</strong>nnes generated each year. Of<br />

this 6.7 million <strong>to</strong>nnes is from UK households, while <strong>the</strong> commercial and industrial sec<strong>to</strong>r also<br />

contributes <strong>to</strong> <strong>the</strong> food waste stream, with 1.6 million <strong>to</strong>nnes from retailers, 4.1 million <strong>to</strong>nnes<br />

from food manufacturers and 3 million <strong>to</strong>nnes from food service and restaurants.<br />

• Tallow is a product of <strong>the</strong> rendering industry, and all UK production, currently estimated <strong>to</strong> be<br />

250,000 <strong>to</strong>nnes per annum, is al<strong>read</strong>y used for some commercial function. Use of this material<br />

for alternative purposes, e.g. bio-diesel production, is al<strong>read</strong>y occurring and is disrupting<br />

traditional markets.<br />

• Textile waste arises mainly from MSW and C&I waste streams, estimated <strong>to</strong> be 1.9 million <strong>to</strong>nnes<br />

each year in <strong>the</strong> UK. Reuse of high and medium quality textiles offers significant environmental<br />

benefits, only when textiles are very badly damaged or soiled does energy recovery and similar<br />

solutions become advisable.<br />

145 Recovery and recycling of waste paper and board: 1993 – 2007, Defra, 2008,<br />

http://www.defra.gov.uk/environment/statistics/waste/download/xls/wrtb20.xls<br />

146 Key industry facts 2007. Confederation of Paper Industries, 2008.<br />

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• Paper waste arises largely from MSW and C&I waste streams, and <strong>to</strong>tals between 12 and 13<br />

million <strong>to</strong>nnes of recoverable paper and board each year, of which 7.3 million <strong>to</strong>nnes is from<br />

MSW, 2.7 million <strong>to</strong>nnes from industry and 6 million <strong>to</strong>nnes is from commercial waste. However<br />

much paper and board is thrown away in general waste so <strong>the</strong> <strong>to</strong>tal C&I waste may be 19 million<br />

<strong>to</strong>nnes. It is estimated that arisings of this waste material will increase <strong>by</strong> a small amount in <strong>the</strong><br />

future.<br />

The potential for <strong>the</strong>se fuels are summarised in Table 47


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Table 47 Summary of biomass based wastes arising across <strong>the</strong> UK (‘000 <strong>to</strong>nnes).<br />

Region MSW Wood<br />

Waste (inc.<br />

furniture)<br />

C&D Waste<br />

Wood<br />

C&I Waste<br />

Wood<br />

MSW Food<br />

Waste<br />

C&I Food<br />

Waste<br />

87<br />

Textiles<br />

MSW and<br />

C&I<br />

MSW Paper<br />

and<br />

Cardboard<br />

C&I Paper<br />

and<br />

Cardboard<br />

East Midlands 76 - - 382 - 167 507 1,510<br />

East of England 95 - - 497 - 156 637 1,727<br />

London 130 - - 585 - 191 871 1,861<br />

North East 47 - - 222 - 98 318 1,058<br />

North West 127 - - 630 - 202 851 1,917<br />

South East 143 - - 742 - 219 958 2,036<br />

South West 92 - - 463 - 139 615 1,278<br />

West Midlands 93 - - 466 - 166 628 1,671<br />

Yorkshire and Humber 90 - - 438 - 221 602 2,561<br />

England - Total 892 3,870 - 4,425 6,189 1560 5,986 15,619<br />

Nor<strong>the</strong>rn Ireland 34 40 - 176 - 44 223 368<br />

Scotland 94 270 - 539 457 145 722 1,219<br />

Wales 56 220 - 277 262 151 378 1,794<br />

UK - Total 1,660 4,400 4,481 5,417 6,908 1900 7,309 19,000<br />

Tallow has not been included in <strong>the</strong> above table as all production is currently utilised.


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6 Waste Management Legislation and<br />

Incentives<br />

Legislation and incentives are <strong>the</strong> most important drivers controlling waste management policy. Waste<br />

Framework Directives from <strong>the</strong> European Commission determine <strong>the</strong> broad direction of policy and fur<strong>the</strong>r<br />

directives and UK legislation determine <strong>the</strong> detail of its execution.<br />

The Renewables Obligation, Renewable Transport Fuels Obligation and future heat incentives will shape<br />

<strong>the</strong> industry and encourage <strong>the</strong> generation of heat both directly and <strong>by</strong> separation and manufacture of<br />

biomass fuel products.<br />

The main areas of legislation that national and regional waste strategies need <strong>to</strong> consider are <strong>the</strong> Waste<br />

Framework Directive, Environmental Permitting and <strong>the</strong> Landfill Directive.<br />

Waste Framework Directive<br />

Entered in<strong>to</strong> force December 2008<br />

The European Commission published a revised Waste Framework Directive (2008/98/EC) in November<br />

2008, and <strong>the</strong> UK has 2 years <strong>to</strong> transpose this in<strong>to</strong> law. This Directive sets a revised framework for<br />

waste management in <strong>the</strong> EU, and aims <strong>to</strong> encourage re-use and recycling of waste as well as simplifying<br />

current legislation. The main points of <strong>the</strong> Directive are:<br />

• A five-step hierarchy of waste management options, with waste prevention as <strong>the</strong> preferred<br />

option, and <strong>the</strong>n reuse, recycling, recovery (including energy recovery) and safe disposal, in<br />

descending order. The Directive classifies "energy efficient" incineration as recovery in an<br />

attempt <strong>to</strong> reduce consumption of fossil fuels.<br />

• Measures <strong>to</strong> encourage prevention of waste. Member States must design and implement<br />

waste prevention programmes, and <strong>the</strong> Commission is set <strong>to</strong> <strong>report</strong> periodically on progress<br />

concerning waste prevention.<br />

• Requirements for a 50% target for household recycling and reuse and 70% target for nonhazardous<br />

construction and demolition waste, both of which must be reached <strong>by</strong> <strong>the</strong> UK <strong>by</strong><br />

2020.<br />

Some departure from this hierarchy is permissible <strong>to</strong> deliver <strong>the</strong> best overall environmental outcome as justified<br />

<strong>by</strong> life cycle thinking.<br />

The Directive also deals with <strong>the</strong> issue of 'end of waste', clarifies <strong>the</strong> idea of recovery, disposal and <strong>by</strong>product,<br />

defines <strong>the</strong> conditions for mixing hazardous waste, introduces an "environmental objective" and<br />

moves <strong>to</strong>wards establishing technical minimum standards for certain waste management operations.<br />

The current EC Waste Framework Directive (75/442/EEC) requires <strong>the</strong> disposal, recovery, treatment,<br />

transport and collection of ‘controlled waste’ streams such as MSW, Hazardous Wastes, C&I and Inert<br />

wastes.<br />

Landfill Directive<br />

Entered in<strong>to</strong> force July 2001<br />

The European Commission Landfill Directive of 1999 (1999/31/EC) was passed in<strong>to</strong> English and Welsh<br />

law in 2002, and Scottish law in 2003. This aims <strong>to</strong> prevent, or minimise, <strong>the</strong> negative effects on both <strong>the</strong><br />

environment and human health caused <strong>by</strong> landfilling of wastes.


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One highly relevant aspect of this Directive <strong>to</strong> <strong>the</strong> production of fuels and energy is <strong>the</strong> requirement that<br />

<strong>the</strong> amount of biodegradable MSW sent <strong>to</strong> landfill in <strong>the</strong> UK <strong>to</strong> be reduced:<br />

• <strong>to</strong> 75% of 1995 levels <strong>by</strong> 2010,<br />

• <strong>to</strong> 50% of 1995 levels <strong>by</strong> 2013, and<br />

• <strong>to</strong> 35% of 1995 levels <strong>by</strong> 2020.<br />

Environmental Permitting Regulations (EPR) 147<br />

Entered in<strong>to</strong> force April 2008<br />

Environmental permitting combines Pollution Prevention and Control (PPC) 148 and waste management<br />

licensing in<strong>to</strong> a single system for England and Wales. Many facilities for waste or residue heat, power or<br />

fuel production will need <strong>to</strong> be licensed under <strong>the</strong>se regulations, although <strong>the</strong>re are lower size limits below<br />

which no license is required. For fur<strong>the</strong>r information on whe<strong>the</strong>r or not a facility comes under EPR <strong>the</strong><br />

opera<strong>to</strong>r should consult <strong>the</strong> Environment Agency which licenses most EPR sites.<br />

EPR covers a very wide range of industrial activities, but <strong>the</strong> main activities covered <strong>by</strong> <strong>the</strong>se regulations,<br />

and of relevance regarding <strong>the</strong> use of waste or residual biomass as a fuel, are:<br />

• Burning of any fuel or waste (in any type of plant)<br />

• Gasification and pyrolysis of any fuel or waste<br />

The requirement <strong>to</strong> apply for and hold a relevant permit applies whe<strong>the</strong>r <strong>the</strong> material is processed in a<br />

dedicated facility, intermittently or as an admixture. Permits are issued for <strong>the</strong> plant as operated in <strong>the</strong><br />

permit application. Variations in operation require a variation in <strong>the</strong> permit, so that changes in <strong>the</strong> fuel<br />

used in biomass plants will require a variation in <strong>the</strong> permit.<br />

The Waste Incineration Directive (WID)<br />

Entered in<strong>to</strong> force December 2002<br />

For waste combustion this licensing will also include consideration of <strong>the</strong> Waste Incineration Directive<br />

(WID). This Directive sets out stringent emissions limits from waste combustion. The WID applies <strong>to</strong><br />

incineration and co-incineration plants. Co-incineration plants include those plants where waste is used<br />

as a fuel or where it is disposed of at a plant where energy generation or production is <strong>the</strong> main purpose.<br />

149<br />

A plant will only be an incineration plant or a co-incineration plant if it burns waste as defined in <strong>the</strong> Waste<br />

Framework Directive (WFD). This definition is extremely broad and <strong>the</strong>re are, in effect, very few<br />

circumstances where <strong>by</strong>-products, co-products or residues are not classified as wastes. 150<br />

Agricultural and forestry residues are not defined as wastes and as such <strong>the</strong> WID will not apply <strong>to</strong> <strong>the</strong>ir<br />

combustion. However, <strong>the</strong>re are many wastes that contain biomass whose treatment is not so clear cut.<br />

In particular <strong>the</strong> treatment of <strong>the</strong> combustion of waste wood for <strong>the</strong> purposes of WID is complicated.<br />

Current Environment Agency guidance 151 is that all waste wood is a waste, but <strong>the</strong> combustion of certain<br />

types of untreated waste wood (i.e. waste wood that has not been treated with preservatives or coatings)<br />

is exempt from WID. However, <strong>the</strong> combustion of wood waste that contains halogenated hydrocarbons<br />

147<br />

The EPR are available from: http://www.opsi.gov.uk/si/si2007/uksi_20073538_en_3#pt2-ch1-l1g12 and guidance is provided on<br />

http://www.netregs.gov.uk/netregs/63143.aspx<br />

148<br />

For fur<strong>the</strong>r guidance on PPC see http://www.defra.gov.uk/environment/ppc/regs/index.htm and http://www.netregs.gov.uk/netregs/63432.aspx<br />

149<br />

Defra, Environmental Permitting Guidance: The Directive on <strong>the</strong> Incineration of Waste, 2008.<br />

150<br />

The EC has provided guidance on <strong>the</strong> definition of waste: CEC: COM(2007) 59 final COMMUNICATION FROM THE COMMISSION TO THE<br />

COUNCIL<br />

AND THE EUROPEAN PARLIAMENT on <strong>the</strong> Interpretative Communication on waste and <strong>by</strong>-products<br />

151 EA (2008) The environmental regulation of wood, Position Statement. www.environment-agency.gov.uk/commondata/acrobat/ps_005_2077240.pdf<br />

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or heavy metals will come under WID, as will <strong>the</strong> combustion of any source of waste wood that might be<br />

contaminated with ei<strong>the</strong>r of <strong>the</strong>se sets of chemicals.<br />

WID sets out details including <strong>the</strong> operating conditions, including gas temperatures and residence times,<br />

limits on emission levels for a range of substance <strong>to</strong> air and water including dioxins and <strong>the</strong> moni<strong>to</strong>ring<br />

requirements on <strong>the</strong>se substances.<br />

Renewable Energy Directive (RED)<br />

Published June 2009<br />

The RED, which came in<strong>to</strong> EU law in April 2009, is designed <strong>to</strong> help states progress <strong>to</strong>wards meeting <strong>the</strong><br />

EU 2020 target of 20% energy derived from renewable sources. The target for <strong>the</strong> UK is 15%. 152 Within<br />

<strong>the</strong> RED biomass is defined <strong>to</strong> include <strong>the</strong> biodegradable fraction of industrial and municipal wastes and<br />

residues from agriculture and forestry.<br />

There are two areas of RED that are important <strong>to</strong> wastes and residues; <strong>the</strong>se are <strong>the</strong> conditions provided<br />

for biofuels and those for biomass heat and power:<br />

Biofuels: Among o<strong>the</strong>r things <strong>the</strong> RED brings in sustainability requirements and <strong>report</strong>ing<br />

requirements for biofuels. Guidance on <strong>the</strong>se will be provided <strong>by</strong> <strong>the</strong> EC <strong>by</strong> early 2010. Biofuels<br />

produced from waste and residues (o<strong>the</strong>r than agricultural, aquaculture, fisheries and forestry<br />

residues) are exempted from some of <strong>the</strong>se sustainability requirements. The RED requires a<br />

greenhouse gas emission savings from biofuels of at least 35%, but it also states that <strong>the</strong> contribution<br />

made <strong>by</strong> biofuels produced from wastes and residues and <strong>the</strong> lignocellulosic component of biomass<br />

will be considered <strong>to</strong> be twice that made <strong>by</strong> o<strong>the</strong>r biofuels. This is a strong driver for <strong>the</strong> use of<br />

wastes and residues and for <strong>the</strong> development of processes using <strong>the</strong> lignocellulosic components of<br />

biomass.<br />

In addition in <strong>the</strong> calculation of default values for biofuels (Annex V), <strong>the</strong> Directive states: “Wastes,<br />

agricultural crop residues, including straw, bagasse, husks, cobs and nut shells, and residues from<br />

processing, including crude glycerine (glycerine that is not refined), shall be considered <strong>to</strong> have zero<br />

life-cycle greenhouse gas emissions up <strong>to</strong> <strong>the</strong> process of collection of those materials.” These default<br />

values will be subject <strong>to</strong> review. This simplification is positive for <strong>the</strong> use of straw and o<strong>the</strong>r harvest<br />

residues for energy that would have higher greenhouse gas emissions allocated from cultivation and<br />

alternative use under a <strong>full</strong> life cycle analysis. It would be more negative for manures and food<br />

wastes that would expect <strong>to</strong> be allocated a strong emissions reduction credit for avoided methane<br />

emissions from alternative disposal routes.<br />

Finally Member States may encourage <strong>the</strong> use of biofuels which give additional benefits, including <strong>the</strong><br />

benefits of diversification offered <strong>by</strong> biofuels made from waste and residues. This adds up <strong>to</strong> a<br />

considerable number of additional incentives <strong>to</strong> encourage <strong>the</strong> development of biofuels from wastes<br />

and residues.<br />

Biomass heat and power: In 2009 <strong>the</strong> Commission will examine whe<strong>the</strong>r or not <strong>to</strong> introduce<br />

sustainability requirements for all biomass for energy (including biomass for heat and power) similar<br />

<strong>to</strong> those for biofuels. The European Commission published <strong>the</strong> summary <strong>report</strong> of responses <strong>to</strong> its<br />

recent consultation on <strong>the</strong> requirement for sustainability criteria for biomass for energy (o<strong>the</strong>r than<br />

biofuels or bioliquids). This will provide input <strong>to</strong> <strong>the</strong> Commission's follow-up <strong>report</strong> planned for<br />

December 2009. 153<br />

An action plan for <strong>the</strong> implementation of <strong>the</strong> RED within UK law needs <strong>to</strong> be prepared <strong>by</strong> 30 th June 2010.<br />

152 Proposed Directive http://ec.europa.eu/energy/climate_actions/doc/2008_res_directive_en.pdf<br />

153 http://ec.europa.eu/energy/renewables/consultations/doc/results_public_consultation_biomass_sustainability_scheme.pdf


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Renewable Energy Strategy (RES)<br />

Published July 2009<br />

As part of <strong>the</strong> implementation process for RED <strong>the</strong> UK Government has produced a draft Renewable<br />

Energy Strategy. The current draft introduces a number of measures that are of relevance <strong>to</strong> wastes and<br />

residues, including <strong>the</strong> Renewable Heat Incentive. 154 It also recognises <strong>the</strong> importance of energy from<br />

waste for <strong>the</strong> UK and discusses measures <strong>to</strong> encourage WID-compliant combustion and raising<br />

awareness of <strong>the</strong> benefits of bioenergy including energy from waste. In addition it also introduces <strong>the</strong><br />

concept of sustainability for bioenergy, discusses <strong>the</strong> potential for imports and discusses <strong>the</strong> potential for<br />

building biomass and waste supply chains in <strong>the</strong> UK.<br />

Renewable Transport Fuel Obligation (RTFO)<br />

Entered in<strong>to</strong> force April 2008<br />

The Government’s Renewable Transport Fuel Obligation (RTFO), which came in<strong>to</strong> effect in April 2008,<br />

has since been amended following <strong>the</strong> conclusions of <strong>the</strong> Gallagher Review released in July 2008. The<br />

RFTO now requires road transport fuel suppliers <strong>to</strong> ensure that, <strong>by</strong> 2013, 5% of <strong>to</strong>tal road transport fuel<br />

supply in <strong>the</strong> UK is made up of renewable fuels, equivalent <strong>to</strong> around 2.5 billion litres of fuel per annum.<br />

These targets work on a volume basis, and <strong>the</strong>refore encourage use of <strong>the</strong> cheapest feeds<strong>to</strong>cks for <strong>the</strong><br />

generation of biofuels, commonly sugar and starch crops. It is recognised that <strong>the</strong>se biofuels are not <strong>the</strong><br />

most effective for Greenhouse Gas emissions reduction, and <strong>the</strong> long term policy is <strong>to</strong> introduce second<br />

generation biofuels with higher GHG savings potentials. GHG savings compared with petrol or diesel are<br />

typically 40-70% for biodiesel from oil seed rape and 30-70% for bioethanol from wheat, compared <strong>to</strong><br />

savings of 86-93% estimated for second generation biofuels.<br />

The UK Biomass Strategy 155<br />

Published May 2007<br />

The Biomass Strategy indicates that biomass will have a central role <strong>to</strong> play in meeting <strong>the</strong> EU target of<br />

20% renewable energy <strong>by</strong> 2020, and will likely have a more regional focus than <strong>the</strong> current energy<br />

networks. The Strategy covers <strong>the</strong> biomass generated as waste and residues, including agricultural<br />

residues, both wet and dry; forestry and horticultural residues; biodegradable content of MSW;<br />

biodegradable content of Commercial and Industrial waste.<br />

It will be necessary <strong>to</strong> increase <strong>the</strong> supply from organic waste materials such as manures and slurries,<br />

source-separated waste biomass and waste-derived solid recovered fuels. In particular faster growth in<br />

<strong>the</strong> development of AD is desired, including examination of how and whe<strong>the</strong>r economic or fiscal<br />

instruments can facilitate increased use of AD.<br />

The Biomass Strategy introduced a number of key initiatives that are relevant <strong>to</strong> biomass wastes and<br />

residues, including <strong>the</strong> Biomass Energy Centre web site; 156 <strong>the</strong> Biomass Capital Grants Scheme; 157 a<br />

review of <strong>the</strong> approach <strong>to</strong> Anaerobic Digestion 158 and a Woodfuel Strategy, which aims <strong>to</strong> bring 2 million<br />

green <strong>to</strong>nnes of wood (including forestry residues) on<strong>to</strong> <strong>the</strong> market <strong>by</strong> 2020.<br />

Proposed Renewable Heat Incentive (RHI)<br />

Proposed in <strong>the</strong> 2008 Energy Bill<br />

154<br />

In fact firm proposals for <strong>the</strong> Renewable Heat Incentive are introduced in <strong>the</strong> Heat and Energy Saving Strategy launched <strong>by</strong> <strong>the</strong> Government in<br />

February 2009.<br />

155<br />

The UK Biomass Strategy, www.defra.gov.uk/environment/climatechange/uk/energy/renewablefuel/pdf/ukbiomassstrategy-0507.pdf<br />

156<br />

See: http://www.biomassenergycentre.org.uk/portal/<br />

157<br />

For fur<strong>the</strong>r information see: http://www.defra.gov.uk/environment/climatechange/uk/energy/fund/<br />

158<br />

This has lead <strong>to</strong> a commitment of £10M for <strong>the</strong> Environmental Transformation Fund <strong>to</strong> fund AD projects in England.<br />

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The Renewable Heat Incentive is likely <strong>to</strong> apply <strong>to</strong> <strong>the</strong> generation of renewable heat at all scales, through<br />

a range of technologies including biomass, solar hot water, air- and ground-source heat pumps, biomass<br />

CHP, biogas produced from anaerobic digestion, and biomethane injected in<strong>to</strong> <strong>the</strong> gas grid, although it<br />

will potentially be banded <strong>by</strong> size and technology.<br />

The scheme would be paid for <strong>by</strong> <strong>the</strong> introduction of a levy on suppliers of fossil fuels for heat,<br />

administered <strong>by</strong> Ofgem. Such suppliers largely supply gas currently, but it would also include suppliers of<br />

coal, heating oil and LPG. DECC currently expect <strong>the</strong> RHI <strong>to</strong> be in place April 2011.<br />

Renewables Obligation (RO)<br />

Entered in<strong>to</strong> force in April 2002<br />

Consultation on <strong>the</strong> Renewables Obligation Order 2009, published December 2008<br />

The Renewables Obligation aims <strong>to</strong> support and encourage <strong>the</strong> increasing adoption of renewable<br />

electricity in <strong>the</strong> UK. It requires licensed electricity suppliers <strong>to</strong> source a specific and annually increasing<br />

percentage of <strong>the</strong> electricity <strong>the</strong>y supply from renewable sources. The current level is 9.1% for 2008/09<br />

rising <strong>to</strong> 15.4% <strong>by</strong> 2015/16.<br />

A Renewables Obligation Certificate (ROC) is a green certificate issued <strong>to</strong> an accredited genera<strong>to</strong>r for<br />

eligible renewable electricity generated within <strong>the</strong> United Kingdom and supplied <strong>to</strong> cus<strong>to</strong>mers within <strong>the</strong><br />

United Kingdom <strong>by</strong> a licensed electricity supplier. Originally one ROC is issued for each megawatt hour<br />

(MWh) of eligible renewable output generated, but <strong>the</strong> update <strong>to</strong> this system in April 2009 introduced a<br />

banding. 159<br />

The targets for <strong>the</strong> RO are linked <strong>to</strong> <strong>the</strong> targets that <strong>the</strong> UK is committed <strong>to</strong> through <strong>the</strong> European Union’s<br />

Renewables Directive. This proposes that Member States adopt national targets for renewables that are<br />

consistent with reaching <strong>the</strong> overall EU target of 22.1% of electricity <strong>by</strong> 2010. The proposed UK share of<br />

this target is for 10% of electricity consumption <strong>to</strong> come from renewables eligible under <strong>the</strong> directive <strong>by</strong><br />

2010.<br />

To demonstrate that <strong>the</strong>y have met <strong>the</strong>ir share of <strong>the</strong> RO, suppliers must obtain certificates for renewable<br />

power supplied. These certificates (Renewable Obligation Certificates - ROCs, and SROCs in Scotland)<br />

are issued <strong>to</strong> genera<strong>to</strong>rs in accordance with <strong>the</strong> metered output of eligible renewable electricity <strong>the</strong>y have<br />

supplied. The certificates may be sold on <strong>to</strong> any supplier, with or without <strong>the</strong> electricity, and suppliers<br />

must redeem certificates with Ofgem (<strong>the</strong> Electricity and Gas Industries Regula<strong>to</strong>r) at <strong>the</strong> end of each 12<br />

month Obligation period <strong>to</strong> demonstrate <strong>the</strong>ir compliance with <strong>the</strong> obligation.<br />

Climate Change Levy (CCL)<br />

Entered in<strong>to</strong> force in April 2001<br />

The Climate Change Levy (CCL) 160 is a levy on non-domestic energy supply in <strong>the</strong> UK, which is offset <strong>by</strong><br />

a reduction in employer’s national insurance contributions. The CCL is under <strong>the</strong> management of <strong>the</strong><br />

HMRC. Accreditation is carried out via Ofgem.<br />

Under <strong>the</strong> CCL non-domestic electricity cus<strong>to</strong>mers are required <strong>to</strong> pay <strong>the</strong> levy as follows:<br />

• 0.47p/kWh for electricity,<br />

• 0.164p/kWh for gas,<br />

• 1.02p/kg (equivalent <strong>to</strong> 0.15p/kWh) for coal and<br />

159 Bioenergy Review for <strong>the</strong> Environment Agency, Draft Report, January 2009.<br />

160 For more information see <strong>the</strong> HMRC web site: http://cus<strong>to</strong>ms.hmrc.gov.uk/


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• 0.105p/kg (equivalent <strong>to</strong> 0.07p/kWh) for liquefied petroleum gas (LPG).<br />

The CCL has a number of exemptions, including fuels used <strong>by</strong> domestic users, fuels used <strong>by</strong> <strong>the</strong><br />

transport sec<strong>to</strong>r, fuels used for <strong>the</strong> generation of o<strong>the</strong>r forms of energy (e.g. electricity generation) or for<br />

non-energy generation (e.g. <strong>the</strong> use of “fuels” as carbon sources for o<strong>the</strong>r purposes, such as a reductant<br />

in metal smelting). In addition <strong>the</strong>re are various ways that <strong>the</strong> cost of <strong>the</strong> levy can be reduced. For<br />

example, <strong>the</strong>re is an 80% discount from <strong>the</strong> CCL for sec<strong>to</strong>rs that agree <strong>to</strong> targets for improving <strong>the</strong>ir<br />

energy efficiency or reducing carbon emissions <strong>by</strong> specified deadlines (“climate change agreements”<br />

(CCA)). 161<br />

There are various o<strong>the</strong>r exemptions but that most relevant <strong>to</strong> energy from waste is that electricity from<br />

renewable sources is exempted from <strong>the</strong> CCL. To qualify, suppliers of renewable electricity must obtain<br />

Renewables Levy Exemption Certificates (“Renewable LECs”). These are issued in respect of eligible<br />

renewable output and are used <strong>to</strong> prove that <strong>the</strong> electricity supplied is from renewable sources. 1 MWh<br />

of renewable power is equal <strong>to</strong> 1 LEC. If this supply is <strong>the</strong>n made <strong>to</strong> a non-domestic cus<strong>to</strong>mer it will not<br />

attract CCL payments. Guidance on <strong>the</strong> HMRC web site indicates that exempt renewable sources<br />

include municipal and industrial wastes and agricultural and forestry residues, as explained in Box 2<br />

Box 2 Rules for Levy Exemption certificates (LECs) for waste and biomass under <strong>the</strong> CCL<br />

LECS for waste fuelled generating stations<br />

The regulations allow for LECs <strong>to</strong> be granted for 50% of <strong>the</strong> electricity from power stations fuelled <strong>by</strong><br />

waste. If <strong>the</strong> opera<strong>to</strong>r considers that <strong>the</strong> proportion of renewable energy content of <strong>the</strong> waste is higher<br />

than 50% and he can provide sufficient evidence <strong>to</strong> Ofgem <strong>the</strong>n more than 50% may be claimed.<br />

LECs for Biomass power generation<br />

To claim LECs <strong>the</strong> biomass power station opera<strong>to</strong>rs must provide <strong>the</strong> following information <strong>to</strong> Ofgem:<br />

o The proposed % of biomass<br />

o Full details of <strong>the</strong> biomass content showing proportions of each category <strong>by</strong> weight<br />

o The CV (MJ/kg) of each category of feeds<strong>to</strong>ck, giving details of how this was obtained.<br />

o A description of facilities for s<strong>to</strong>ring biomass<br />

o Details of <strong>the</strong> supplier(s) of biomass, including names and addresses and a copy of<br />

extracts of contracts that detail <strong>the</strong> biomass content and contract duration.<br />

European Emissions Trading Scheme (EU ETS)<br />

Introduced in 2005<br />

1 st Trading period: January 2005 – December 2007<br />

2 nd Trading period: January 2008 – December 2012<br />

The EU ETS 162 is an EU wide scheme intended <strong>to</strong> help meet <strong>the</strong> EU’s GHG reduction targets under <strong>the</strong><br />

Kyo<strong>to</strong> Pro<strong>to</strong>col. The scheme creates a price for carbon through <strong>the</strong> establishment of a market for carbon<br />

emission reductions. The EU ETS is currently in its second phase, which runs from 2008-2012. The<br />

scheme operates through <strong>the</strong> allocation and trade of greenhouse gas emissions allowances throughout<br />

<strong>the</strong> EU – one allowance represents one <strong>to</strong>nne of carbon dioxide equivalent. A cap on <strong>the</strong> <strong>to</strong>tal amount of<br />

emissions allowed from all <strong>the</strong> installations covered is set <strong>by</strong> each Member State in <strong>the</strong>ir ‘national<br />

allocation plan’ or NAP. The allowances are <strong>the</strong>n distributed within Member States <strong>to</strong> <strong>the</strong> qualifying<br />

installations. In <strong>the</strong> UK, <strong>the</strong> ETS is implemented via UK Regulations that are regulated <strong>by</strong> <strong>the</strong><br />

Environment Agency for England and Wales, <strong>the</strong> Scottish Environment Protection Agency in Scotland<br />

and Department for <strong>the</strong> Environment and Heritage Services in Nor<strong>the</strong>rn Ireland.<br />

161<br />

These sec<strong>to</strong>rs are: aluminium, cement, ceramics, chemicals, food and drink, foundaries, glass, non-ferrous metals , paper, steel, and 20 or so<br />

smaller sec<strong>to</strong>rs.<br />

162<br />

For more information on <strong>the</strong> Eu ETS see <strong>the</strong> Defra web site: http://www.defra.gov.uk/environment/climatechange/trading/eu/index.htm and <strong>the</strong><br />

Environment Agency’s NatRegs site: http://www.netregs.gov.uk/netregs/62975.aspx<br />

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Currently <strong>the</strong> energy, iron and steel, mineral process and pulp and paper industries are covered <strong>by</strong> EU<br />

ETS. All installations carrying out activities in <strong>the</strong>se areas are required <strong>to</strong> hold a GHG emissions permit,<br />

which will require <strong>the</strong> installations <strong>to</strong> moni<strong>to</strong>r and <strong>report</strong> emissions in accordance with a plan that has<br />

been approved <strong>by</strong> <strong>the</strong> Regula<strong>to</strong>r.<br />

A site becomes liable under <strong>the</strong> EU ETS when <strong>the</strong> sum of <strong>the</strong> site’s rated combustion capacity exceeds<br />

20MW (<strong>the</strong>rmal). 163 Once over this limit <strong>the</strong> site’s CO2 emissions are capped and strict moni<strong>to</strong>ring is<br />

required. Emissions are required <strong>to</strong> stay within <strong>the</strong> cap or <strong>the</strong> site will need <strong>to</strong> trade carbon. Biomass or<br />

waste boilers are included <strong>to</strong>wards <strong>the</strong> <strong>to</strong>tal site limit. Therefore an opera<strong>to</strong>r cannot reduce <strong>the</strong> site’s<br />

generating capacity under EU ETS <strong>by</strong> substituting biomass or waste fuelled plant for fossil fuel plant.<br />

However, CO2 emissions from biomass are rated as zero under EU ETS, which means that any carbon<br />

emissions resulting from <strong>the</strong> biomass will not count <strong>to</strong>wards <strong>the</strong> site’s emissions. This may help a site<br />

meet its limit for GHG emissions and be able <strong>to</strong> trade any surplus.<br />

The relevance of this <strong>to</strong> waste for energy is that <strong>the</strong> biomass content of waste will also be rated as zero –<br />

and for high biomass wastes this is a considerable advantage, provided <strong>the</strong> biomass content can be<br />

easily demonstrated<br />

In addition a third phase, running from 2013, is in planning. One of <strong>the</strong> proposals under consideration is<br />

<strong>to</strong> set an emission target for sec<strong>to</strong>rs not covered <strong>by</strong> <strong>the</strong> current ETS (e.g. <strong>the</strong> buildings, transport and<br />

waste sec<strong>to</strong>rs). In addition <strong>the</strong> next phase may include o<strong>the</strong>r emissions as well as CO2.<br />

163 According <strong>to</strong> Defra’s guidance: ‘<strong>the</strong> EU ETS Directive expressly states that <strong>the</strong> burning of municipal waste and hazardous waste is not treated as a<br />

“combustion installation” for <strong>the</strong> purposes of <strong>the</strong> EU ETS. Where primary purpose of incineration is <strong>the</strong> provision of energy using a fuel derived from<br />

waste, <strong>the</strong>n <strong>the</strong> installation is a “combustion installation” under <strong>the</strong> medium definition.’


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7 Solid recovered fuels and o<strong>the</strong>r fuels<br />

manufactured from waste<br />

Each energy conversion technology is limited in <strong>the</strong> range of fuel types that it can accept and places<br />

demands on <strong>the</strong> preceding steps in <strong>the</strong> chain, in terms of fuel quality, properties and composition.<br />

Technologies are being introduced in <strong>the</strong> UK and elsewhere that transform waste components from <strong>the</strong>ir<br />

raw form <strong>to</strong> standard fuels with a defined specification. Manufactured fuels can offer <strong>the</strong> following<br />

benefits:<br />

• Consistent properties that can be defined and used in contracts making <strong>the</strong> material a tradable<br />

commodity.<br />

• Physical and biological stability that makes longer term s<strong>to</strong>rage possible and can even out<br />

unbalances between <strong>the</strong> constant supply of waste and <strong>the</strong> seasonal demand for energy.<br />

• An opportunity <strong>to</strong> manage <strong>the</strong> properties of <strong>the</strong> fuel <strong>to</strong> achieve optimum performance from <strong>the</strong><br />

energy technology.<br />

These fuels are in many ways <strong>the</strong> key <strong>to</strong> using waste in a diverse range of energy technologies that offer<br />

higher resource use efficiency and enhanced greenhouse gas reduction potential when compared <strong>to</strong><br />

traditional combustion with energy recovery. They allow CHP installations <strong>to</strong> be sized according <strong>to</strong> <strong>the</strong><br />

heat load and processes <strong>to</strong> manufacture transport fuels and methane <strong>to</strong> be operated at an economic<br />

scale.<br />

We have identified <strong>the</strong> following manufactured fuels on sale or planned in <strong>the</strong> UK.<br />

• Solid recovered fuels. These fuels are produced from mixed wastes from <strong>the</strong> municipal and<br />

commercial stream <strong>by</strong> separating <strong>the</strong> high heating value components from <strong>the</strong> residues remaining<br />

after conventional recycled products have been removed. The material contains both biological<br />

and non-biological matter. They are supplied dried and ei<strong>the</strong>r shredded for short distance and<br />

short term transport or compressed in<strong>to</strong> pellets for longer distances and s<strong>to</strong>rage times.<br />

• Graded waste wood fuels. This sec<strong>to</strong>r is growing rapidly as wood fired power plants are built <strong>to</strong><br />

take advantage of <strong>the</strong> reformed Renewables Obligation. Waste wood is collected from industry<br />

and amenity centres and graded depending on <strong>the</strong> level of contamination. The grades are <strong>the</strong>n<br />

chipped and sold <strong>to</strong> a specification.<br />

• Clean grade wood chips from virgin materials. Here wood residues for forestry and sawmills<br />

are chipped and potentially dried <strong>to</strong> meet a specification.<br />

• Domestic grade wood pellet fuel from saw mill <strong>by</strong>-product. Sawmill residues, in particular<br />

sawdust, is dried and compressed through a die in<strong>to</strong> small cylinders approximately 6mm in<br />

diameter and 10 mm long. This fuel resembles cattle feed or cat litter and is clean and free<br />

flowing. Several small scale combustion appliances have been developed <strong>to</strong> take advantage of<br />

<strong>the</strong> properties of this fuel. The high energy density means that it can be transported economically<br />

regionally, nationally, and internationally.<br />

• Industrial grade pellet from forestry, cereal processing residue and clean waste wood.<br />

This is similar <strong>to</strong> <strong>the</strong> domestic pellet but has a higher ash content and larger size.<br />

• Thermochemical fuels. These are chars and pyrolysis oils produced close <strong>to</strong> <strong>the</strong> point of<br />

arising. Supplied ei<strong>the</strong>r separately or as a slurry mix, <strong>the</strong> increased energy density extends <strong>the</strong><br />

economic transport distance for local <strong>to</strong> national. These fuels are not currently produced but<br />

have been proposed as a feeds<strong>to</strong>ck option for large gasification processes producing 2 nd<br />

generation biofuels or Substitute Natural Gas (SNG). We also include <strong>to</strong>rrefaction, or high<br />

temperature drying in this category.<br />

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7.1 Technologies for manufacturing fuels<br />

7.1.1 Mechanical / biological processing of MSW <strong>to</strong> Solid Recovered Fuel<br />

(SRF)<br />

C & I waste<br />

MSW<br />

Process Description<br />

Mechanical/biological treatment (MBT) encompasses a wide range of technologies aiming <strong>to</strong> process<br />

solid waste <strong>by</strong> a mixture of mechanical and biological separation. 164 It is not a new technology, and<br />

mechanical sorting and biological treatment processes have been used for many years in municipal<br />

waste management.<br />

MBT plants produce a solid recovered fuel (SRF) product from <strong>the</strong> drier, higher calorific value fractions of<br />

municipal and commercial waste. The first step is aerobic digestion, or fermentation, of solid organic<br />

material (composting) with <strong>the</strong> produced heat drying <strong>the</strong> waste. It is <strong>the</strong>n mechanically sorted <strong>to</strong> produce<br />

a fuel product that contains mainly paper and plastic. Additional fractions are produced that are suitable<br />

for recovery and recycling such as metal, glass and plastic, whilst <strong>the</strong> remaining waste is stabilised as a<br />

pre-treatment <strong>to</strong> landfill.<br />

Commercial status<br />

MBT is commercially available in most countries in <strong>the</strong> EU, and in <strong>the</strong> UK <strong>the</strong>re are a number of<br />

operational sites, <strong>the</strong>se are listed below.<br />

Table 48 Risks and barriers for MBT<br />

Level of Risk Comment<br />

Technical Low Operating commercial plant in existence.<br />

Established mature technologies.<br />

Social & Planning Medium Not as divisive as an incinera<strong>to</strong>r but still subject of<br />

concern as a waste technology. Waste transport<br />

is always a primary concern of residents in <strong>the</strong><br />

locality.<br />

Financial Medium Requires revenue from sale of fuel but market not<br />

well established.<br />

Fuel is still classed as a waste which may give<br />

problems with sale and use and hence price.<br />

Standards and agreed specifications are needed<br />

<strong>to</strong> make <strong>the</strong> fuel product a traded commodity.<br />

Regula<strong>to</strong>ry Medium Fuel is still classed as a waste which may give<br />

problems with sale and use and hence price.<br />

The legal status needs <strong>to</strong> be clarified. Standards<br />

would help <strong>to</strong> clarify definitions.<br />

Focusing on one site <strong>to</strong> give a detailed example of <strong>the</strong> processes used, <strong>the</strong> Frog Island site in east<br />

London is a recent development using <strong>the</strong> proprietary Ecodeco process. This process first shreds <strong>the</strong><br />

waste, <strong>the</strong>n dries it for up <strong>to</strong> 15 days using <strong>the</strong> heat from <strong>the</strong> composting biomass <strong>to</strong> reduce its moisture<br />

164 Mechanical Biological Treatment of Municipal Solid Waste. Prepared <strong>by</strong> Enviros Consulting Limited on behalf of Defra as part of <strong>the</strong> New<br />

Technologies Supporter Programme, 2007.<br />

Mechanical/Biological<br />

Treatment (MBT)<br />

SRF


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content. The dried waste is <strong>the</strong>n sorted, initially using screen separation, <strong>to</strong> produce a fuel product (about<br />

50% of <strong>the</strong> input weight, 15-18 MJ/kg), a metal product (which is recycled), and a residue product (which<br />

is landfilled). Equipment such as magnetic separa<strong>to</strong>rs and eddy current separa<strong>to</strong>rs are used <strong>to</strong> recover<br />

both ferrous and non-ferrous metal for recycling. Table 49 shows <strong>the</strong> typical mass balance for <strong>the</strong> biodrying<br />

process. Alternative methods are <strong>the</strong> Herhof Process, <strong>the</strong> 3R-UR process and <strong>the</strong> Draco Process.<br />

Table 49 Mass balance (Wt%) for bio-drying plants<br />

Fuel product<br />

Eco-deco %<br />

50<br />

Recyclables (metal) 5<br />

Process loss (water vapour from drying of input 25<br />

waste)<br />

Residue – glass/s<strong>to</strong>ne 165 and fines 20<br />

Total 100<br />

Figure 15 Frog Island Ecodeco plant<br />

The following examples of operationally active MBT sites in <strong>the</strong> UK contain a range of processes. The<br />

organic fraction is usually fur<strong>the</strong>r processed, frequently using AD or composting; recyclable materials<br />

such as metals are removed and recycled while materials such as glass may be recycled or may be<br />

ground and added <strong>to</strong> <strong>the</strong> organic compost like output (CLO) fraction.<br />

165 The glass/s<strong>to</strong>ne stream could be fur<strong>the</strong>r processed <strong>to</strong> produce a product suitable for recycling as an aggregate<br />

substitute.<br />

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Table 50 MBT Plants in <strong>the</strong> UK 166<br />

Name and Location Volume Operational<br />

Bursom Industrial Estate<br />

MBT plant in Leicester<br />

150,000 <strong>to</strong>nnes p.a.<br />

The organic fraction is processed<br />

with AD (at Wanlip, see later)<br />

2004<br />

New Earth Solutions in<br />

Poole, Dorset<br />

50,000 <strong>to</strong>nnes p.a.<br />

The organic fraction is<br />

composted, producing 9000<br />

<strong>to</strong>nnes/yr.<br />

2006<br />

Frog Island, Rainham,<br />

Shanks Group Plc, East<br />

180,000 <strong>to</strong>nnes p.a.<br />

2006<br />

London Waste Authority The material bio-dried before<br />

being biologically treated and<br />

sorted. After removal of glass,<br />

metals and aggregates <strong>the</strong><br />

remainder is used as SRF.<br />

Jenkins Lane, Newham,<br />

East London Waste<br />

180,000 <strong>to</strong>nnes p.a.<br />

2007<br />

Authority, Shanks Group The process requires bio-drying<br />

Plc<br />

before materials are refined for<br />

energy recovery.<br />

Earth Tech in S<strong>to</strong>rnoway,<br />

Western Isles<br />

21,000 <strong>to</strong>nnes p.a.,<br />

Uses AD for <strong>the</strong> source separated<br />

waste and composting for <strong>the</strong><br />

residual waste (see later)<br />

2006<br />

Civic Environmental<br />

Systems in<br />

37,000 <strong>to</strong>nnes p.a.<br />

2003<br />

Durham<br />

Commercial development scale<br />

Elling<strong>to</strong>n,<br />

40,000 <strong>to</strong>nnes p.a. of fine, pre- 2006<br />

Northumberland graded material<br />

Shanks Ecodeco plant in<br />

Dumfries and Galloway<br />

60,000 <strong>to</strong>nnes p.a. 2006<br />

At least six MBT plants are currently under construction or have planning permission al<strong>read</strong>y granted:<br />

• A site that will be operational within a few months is <strong>the</strong> 250,000 <strong>to</strong>nnes/yr site at Waterbeach in<br />

Cambridgeshire. Alongside this <strong>the</strong> composting capacity of <strong>the</strong> facility will double <strong>to</strong> 100,000<br />

<strong>to</strong>nnes/yr. 167<br />

• Two sites in Lancashire are under construction, one in Leyland near Pres<strong>to</strong>n, <strong>the</strong> o<strong>the</strong>r at<br />

Thorn<strong>to</strong>n near Blackpool. These will use <strong>the</strong> Global Technology (3R-UR) process and have a<br />

combined capacity of over 300,000 <strong>to</strong>nnes per annum of household waste.<br />

• Southwark MBT plant, intended <strong>to</strong> process 87,500 <strong>to</strong>nnes per annum and <strong>to</strong> be operational <strong>by</strong><br />

2011. The site will produce SRF (solid recovered fuel) <strong>to</strong> be burnt at <strong>the</strong> near<strong>by</strong> SELCHP EfW<br />

plant in Lewisham. 168<br />

• A site near Colchester, Essex has been granted permission for throughput of 250,000 <strong>to</strong>nnes per<br />

annum, with an attached AD plant capable of handling 50,000 <strong>to</strong>nnes/yr. 169<br />

166<br />

Mechanical Biological Treatment of Municipal Solid Waste, 2007, Defra Brief, http://www.defra.gov.uk/environment/waste/wip/newtech/pdf/mbt.pdf<br />

167<br />

ENDS Report, 389, June 2007, p.17,<br />

http://www.ends<strong>report</strong>.com/index.cfm?action=<strong>report</strong>.article&articleID=17363&q=MBT%20plants&boolean_mode=all<br />

168<br />

ENDS Report 397, Feb 2008, p.17,<br />

http://www.ends<strong>report</strong>.com/index.cfm?action=<strong>report</strong>.article&articleID=18636&q=MBT%20plants&boolean_mode=all


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• The potential Westbury MBT plant in Wiltshire has been given planning permission for a 45,000<br />

<strong>to</strong>nnes per annum site that is now due <strong>to</strong> open in 2011. 170<br />

• Bioessence have received planning permission for a 400,000 <strong>to</strong>nne per annum plant in<br />

Merseyside as a pre-treatment step for a pyrolysis/gasification technology <strong>to</strong> generate 40 MW of<br />

electricity. The plant is scheduled <strong>to</strong> start operating in 2011. 171<br />

Fur<strong>the</strong>r sites that are planned, but do not yet have planning permission are a plant in West Sussex that<br />

will use <strong>the</strong> Haase process, a plant in Norwich, Norfolk which would use <strong>the</strong> Dranco process and a plant<br />

in Manchester using <strong>the</strong> BTA process.<br />

In addition <strong>the</strong> INEOS Chlor incinera<strong>to</strong>r site discussed above plans <strong>to</strong> receive <strong>the</strong> 275,000 <strong>to</strong>nnes of<br />

stabilised fuel waste from five MBT and AD sites in Manchester. The contract was announced in January<br />

2007, and funding was secured April 2009. 172<br />

Internationally, MBT is a well established technology, with many operational facilities using a range of <strong>the</strong><br />

processes described above. Several of <strong>the</strong> larger scale ones are detailed below in Table 51. Some of<br />

<strong>the</strong> sites also convert this fuel <strong>to</strong> electricity on site.<br />

Table 51 Examples of best practice large scale international facilities that convert MSW in<strong>to</strong> SRF.<br />

City<br />

Year<br />

Capacity<br />

<strong>to</strong>nnes/yr<br />

Luebeck,<br />

173 2005 150,000<br />

Germany<br />

Corteolona,<br />

Italy 174<br />

Eastern<br />

Creek,<br />

Australia 175<br />

2004 60,000 9MW<br />

2004 175,000 176 1.5 MW<br />

Lauta,<br />

177 2004 225,000 20MW<br />

Germany<br />

Generation<br />

Capacity Comments<br />

1.9MW This site uses <strong>the</strong> Haase process <strong>to</strong> sort<br />

electricity, <strong>the</strong> waste in<strong>to</strong> SRF fuel, inerts,<br />

2.3MW recyclables and an organic rich fraction,<br />

heat which is processed fur<strong>the</strong>r using AD.<br />

This site is operated <strong>by</strong> Ecoenergia S.r.l.<br />

and uses <strong>the</strong> ‘Ecodeco’ process<br />

technology. The SRF produced is used<br />

<strong>to</strong> produce electricity.<br />

The facility is currently being expanded<br />

<strong>to</strong> 220,000 <strong>to</strong>nnes/annum. It utilises <strong>the</strong><br />

3R-UR process and produces three<br />

products; metals for recycling, a fuel<br />

product, and an organics rich product<br />

which is converted <strong>to</strong> compost like<br />

products onsite.<br />

This plant is part of <strong>the</strong> regional waste<br />

plan for Upper Lusatia, Lower Silesia<br />

(RAVON). The plant uses SRF derived<br />

from <strong>the</strong> local area.<br />

169 ENDS Report 393, Oc<strong>to</strong>ber 2007, p.20,<br />

http://www.ends<strong>report</strong>.com/index.cfm?action=<strong>report</strong>.article&articleID=17938&q=MBT%20plants&boolean_mode=all<br />

170 Wiltshire Approves Hills MBT Plant, 23 March 2009, LetsRecycle.com,<br />

http://www.letsrecycle.com/do/ecco.py/view_item?listid=37&listcatid=217&listitemid=31269<br />

171 Plan <strong>to</strong> develop 40MW gasification plant on Merseyside. News item at www.newenergyfocus.com, 28 January 2009.<br />

172 News item at Greater Manchester Waste Disposal Authority - http://www.gmwda.gov.uk/news.htm<br />

173 173 Visit <strong>by</strong> AEA staff <strong>to</strong> Luebeck Plant, June 2008<br />

174 Ecogergia, http://www.ecoenergia.it/ecoenergia_ing/its_termocorteolona.html<br />

175 Eastern Creek in Sydney – A member of AEA visited this plant in 2007<br />

176 Energent Capital, http://www.emergentcapital.com.au/globalrenewables/<br />

177 Lauta, http://www.industcards.com/wte-germany.htm<br />

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Utilising SRF in isolation for energy generation is not common in <strong>the</strong> UK. There are currently two sites<br />

that use this material. Slough Heat and Power in Berkshire is a CHP plant with a generating capacity of<br />

101MW. This site takes up <strong>to</strong> 100,000 <strong>to</strong>nnes of material each year – a combination of clean wood waste<br />

and SRF as one of its boiler systems is WID compliant. The second site at Alling<strong>to</strong>n, in Kent which takes<br />

500,000 <strong>to</strong>nnes per annum of minimally treated SRF <strong>to</strong> produce 43MW electricity from two large bubbling<br />

fluidised bed boilers. 178<br />

There are several industries where making use of SRF is al<strong>read</strong>y established, usually for <strong>the</strong> generation<br />

of heat. Cement kilns are one such industry, <strong>the</strong> paper industry is <strong>the</strong> o<strong>the</strong>r. 166 The British Cement<br />

Association <strong>report</strong>s that all but one of <strong>the</strong> 15 cement kilns in <strong>the</strong> UK use SRF.<br />

7.1.2 Mechanical / Heat Treatment of MSW <strong>to</strong> solid recovered fuel<br />

C & I waste<br />

MSW<br />

Mechanical Heat<br />

Treatment (MHT)<br />

Process Description<br />

Mechanical Heat Treatment (MHT) is a term that is used <strong>to</strong> describe configurations of mechanical and<br />

<strong>the</strong>rmal, including steam, based technologies. The purpose of <strong>the</strong>se processes is <strong>to</strong> separate a mixed<br />

waste stream in<strong>to</strong> several component parts, <strong>to</strong> give fur<strong>the</strong>r options for recycling, recovery and in some<br />

instances biological treatment. The processes also sanitises <strong>the</strong> waste <strong>by</strong> destroying bacteria. The basic<br />

flowchart for a Mechanical Heat Treatment process 179 is shown below in Figure 16.<br />

SRF<br />

Figure 16 Flowchart representing Mechanical Heat Treatment<br />

178 http://www.kentenviropower.co.uk/default.asp<br />

179 A description of MHT processes can be found in “Mechanical Heat Treatment of Municipal Solid Waste”, published <strong>by</strong> Defra in 2007.


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The most common system being promoted for <strong>the</strong> treatment of MSW using MHT is based around a<br />

<strong>the</strong>rmal au<strong>to</strong>clave. The development for use with MSW started in <strong>the</strong> early 1990’s, and a number of<br />

patents have been issued.<br />

A second type of MHT system is a non-pressurised heat treatment process, where waste is mixed <strong>to</strong> a<br />

slurry with water and <strong>the</strong>n heated in a rotating kiln prior <strong>to</strong> mechanical separation. This process requires<br />

a pre-treatment stage, which includes <strong>the</strong> use of a shredder.<br />

Both <strong>the</strong> au<strong>to</strong>clave process and <strong>the</strong> non-pressurised treatment processes have <strong>the</strong> following effect on <strong>the</strong><br />

waste:<br />

• Biodegradable materials, including paper and card, are broken down in<strong>to</strong> a high biomass fibre for<br />

which <strong>the</strong> main use is as a fuel product;<br />

• Glass bottles and tins have <strong>the</strong>ir labels removed as <strong>the</strong> glue disintegrates under <strong>the</strong> action of <strong>the</strong><br />

heat;<br />

• Plastics are softened, and labels are removed. Certain types of plastics are deformed <strong>by</strong> <strong>the</strong> heat,<br />

but remain in a recognisable state, whereas o<strong>the</strong>r plastics soften completely forming hard balls of<br />

dense plastic.<br />

Both processes produce product streams (fibre product, plastic, etc) using well-established mechanical<br />

processing techniques (screening, density separation, magnetic separation, eddy current separation).<br />

The resulting outputs are relatively clean ‘hard’ recyclables (tins, glass and plastics with no labels and<br />

most of <strong>the</strong> food waste removed) a fibrous material from <strong>the</strong> breakdown of paper, card and green/kitchen<br />

waste constituents, and a reject fraction.<br />

Both systems heat <strong>the</strong> waste <strong>to</strong> temperatures in <strong>the</strong> range of 120-170°C, which is sufficient <strong>to</strong> destroy<br />

bacteria present in <strong>the</strong> waste. This has benefits in terms of s<strong>to</strong>rage, transport and handling of <strong>the</strong> outputs<br />

as <strong>the</strong>y are sanitised, and are free from <strong>the</strong> biological activity that may give rise <strong>to</strong> odour problems. There<br />

is also a significant volume reduction in <strong>the</strong> waste.<br />

Table 52 shows <strong>the</strong> typical specification of a mechanical heat treatment plant. About 15-20% of <strong>the</strong> input<br />

waste is landfilled.<br />

Table 52: Typical specification of a mechanical heat treatment process<br />

Product stream Wt % of input MSW<br />

Fibre product 60-65<br />

Metal products 4-5<br />

Mixed plastic product 7-12<br />

Aggregate substitute product 4-8<br />

Landfilled 180 15-20<br />

Total 100<br />

O<strong>the</strong>r products from <strong>the</strong> process<br />

Suppliers of MHT plants claim that <strong>the</strong>se plants can recycle up <strong>to</strong> 20% of <strong>the</strong> input waste. However, whilst<br />

established markets for <strong>the</strong> metal products are available, <strong>the</strong> <strong>to</strong>tal level of recycling achieved will depend<br />

on <strong>the</strong> availability of markets for both <strong>the</strong> mixed plastic product and <strong>the</strong> aggregate substitute product. If<br />

<strong>the</strong>se markets are not available <strong>the</strong>n <strong>the</strong>se products will be landfilled.<br />

Commercial status<br />

Some demonstration projects are operating under <strong>the</strong> Defra Waste Innovation Programme, such as <strong>the</strong><br />

Huy<strong>to</strong>n MHT site in Merseyside.<br />

180 The landfilled reject stream is mainly o<strong>the</strong>r combustible materials.<br />

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Table 53 Risks and barriers for MHT<br />

Level of Risk Comment<br />

Technical High Demonstration projects only at present.<br />

Social & Planning Medium Not as divisive as an incinera<strong>to</strong>r but still subject of<br />

concern as a waste technology.<br />

Financial Medium Requires revenue from sale of fuel but market not<br />

well established.<br />

Fuel is still classed as a waste which may give<br />

problems with sale and use and hence price.<br />

Standards and agreed specifications are needed<br />

<strong>to</strong> make <strong>the</strong> fuel product a traded commodity.<br />

Regula<strong>to</strong>ry Medium Fuel is still classed as a waste which may give<br />

problems with sale and use hence a reduced<br />

price.<br />

The legal status needs <strong>to</strong> be clarified. Standards<br />

would help <strong>to</strong> clarify definitions.<br />

There are a number of suppliers of au<strong>to</strong>clave based MHT technology in <strong>the</strong> UK. Sterecycle 181 have<br />

constructed a 100,000 <strong>to</strong>nnes per annum au<strong>to</strong>clave facility at Ro<strong>the</strong>rham, which is currently treating<br />

residual MSW from three local authorities and has received planning approval <strong>to</strong> double <strong>the</strong> capacity <strong>to</strong><br />

200,000 <strong>to</strong>nnes per annum. 182<br />

The Huy<strong>to</strong>n MHT site in Merseyside uses a Mechanical Heat Treatment technology developed <strong>by</strong> Orchid<br />

Environmental, designed <strong>to</strong> process 80,000 <strong>to</strong>nnes/yr of MSW. 183 The site, which began operation in<br />

June 2008 as a demonstration plant, uses a low heat process, <strong>to</strong>ge<strong>the</strong>r with air and moisture <strong>to</strong> separate<br />

waste and convert <strong>the</strong> organic fraction in<strong>to</strong> fuel pellets. This site is part of <strong>the</strong> DEFRA Demonstra<strong>to</strong>r<br />

Programme, but suffered a fire in 2008. The pre-treated waste is mixed with water, and this is <strong>the</strong>n fed<br />

in<strong>to</strong> a drum, which is heated using hot air.<br />

Graphite Resources obtained planning approval in 2005 for an au<strong>to</strong>clave plant at <strong>the</strong> Derwenthaugh<br />

(Gateshead) Eco-Parc, which will process 300,000 <strong>to</strong>nnes per annum of mainly commercial waste. Plant<br />

construction was delayed due <strong>to</strong> financing issues, but <strong>the</strong> plant is now being constructed, and is<br />

scheduled <strong>to</strong> begin operating in <strong>the</strong> autumn of 2009. 184<br />

Planning permission was received <strong>by</strong> Estech (now part of VT group) for a plant in Herefordshire in 2004,<br />

but construction was delayed when <strong>the</strong> planning approval was challenged, and whilst this has now been<br />

resolved, <strong>the</strong> plant is unlikely <strong>to</strong> be operational until 2012. VT group have received planning permission<br />

for a 100,000 <strong>to</strong>nne per annum au<strong>to</strong>clave in Wakefield as part of a waste treatment site which will also<br />

include an anaerobic digestion facility, and hope <strong>to</strong> secure financial close for this project during 2009. 185<br />

Orchid Environmental have received planning permission from Flintshire county council <strong>to</strong> build a 160,000<br />

<strong>to</strong>nne-a-year capacity mechanical heat treatment facility at Flintshire, Deeside. 186 This site would aim <strong>to</strong><br />

mainly treat commercial and industrial waste, and has plans <strong>to</strong> develop up <strong>to</strong> six similar projects over <strong>the</strong><br />

next two years.<br />

181<br />

http://www.sterecycle.com/<br />

182<br />

Yorkshire au<strong>to</strong>clave plant <strong>to</strong> double capacity. News item at www.letsrecycle.com, 20 January 2009<br />

183<br />

Defra Factsheet, Merseyside WDA/Orchid Environmental, http://www.defra.gov.uk/environment/waste/wip/newtech/dem-programme/pdf/MWDA.pdf<br />

184<br />

Information at www.graphiteresources.com<br />

185<br />

VT Group wins planning go-ahead for Wakefield PFI. News item at www.letsrecycle.com, 28 November 2008.<br />

186<br />

Green Light for £20 million Flintshire MHT plant. News item at letsrecycle.com, 15 December 2008


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7.1.3 Standards for Solid Recovered fuels<br />

There is considerable pressure for solid recovered fuels from MBT and MHT treatment plant <strong>to</strong> be<br />

regarded as products ra<strong>the</strong>r than waste. This has resulted in <strong>the</strong> setting up of a CEN Technical<br />

committee <strong>to</strong> develop a suite of standards for <strong>the</strong> characterisation and analysis of <strong>the</strong>se products -<br />

TC343. The Work Programme for TC 343 is allocated <strong>to</strong> 5 Working Groups:<br />

• WG1 Terminology and Quality Assurance<br />

• WG2 Fuel specifications and classes<br />

• WG3 Sampling, sample reduction and supplementary test methods<br />

• WG4 Physical/Mechanical tests<br />

• WG5 Chemical Tests<br />

The mandate for this standardisation work is given as: -<br />

“fuels prepared from non-hazardous waste <strong>to</strong> be utilised for energy recovery in waste incineration or coincineration<br />

plants regulated under Community environmental legislation”.<br />

The current status is that all Technical Specifications for CEN 343 have now been submitted <strong>to</strong> formal vote and<br />

are expected <strong>to</strong> be come in<strong>to</strong> use as <strong>full</strong> standards in 2011.<br />

7.1.4 Preparation of wood chips and pellets<br />

Wood from forestry operations<br />

Wood fuel currently comes mostly from thinning operations where small diameter trees are felled, and<br />

even smaller diameter branches and material from <strong>the</strong> harvesting of timber logs that is <strong>to</strong>o small <strong>to</strong> be a<br />

primary product. These are chipped ei<strong>the</strong>r as part of <strong>the</strong> harvest operation or are taken <strong>to</strong> <strong>the</strong> roadside<br />

for chipping, or for delivery as small round-wood logs for chipping at <strong>the</strong> users facility.<br />

The latest installations under <strong>the</strong> Bioenergy Capital Grant Scheme have shown a marked preference for<br />

logs as <strong>the</strong>y s<strong>to</strong>re without degradation for a long period, and so can be regarded as a good strategic<br />

reserve, and provide a guaranteed clean fuel with no debris.<br />

Branch wood and <strong>to</strong>ps, so called brash, could be used as fuel but contains a higher proportion of ash,<br />

needles and debris and so is currently not extracted in any quantity. As demand increases <strong>the</strong>n this<br />

situation may change, but use of brash would likely require some engineering modifications <strong>to</strong> boilers <strong>to</strong><br />

cope with <strong>the</strong> increased ash.<br />

For smaller installations <strong>the</strong> quality of chip in terms of its size and moisture is critical <strong>to</strong> <strong>the</strong> reliable<br />

operation of <strong>the</strong> unit. The type of chipper used and <strong>the</strong> way in which <strong>the</strong> material is s<strong>to</strong>red plays an<br />

important part in guaranteeing good quality feeds<strong>to</strong>ck. Drum chippers produce <strong>the</strong> best quality and cut<br />

chip product should be s<strong>to</strong>red under cover.<br />

Pellet production from sawmill <strong>by</strong>-product<br />

Sawmills generate large quantities of sawdust that can be converted in <strong>to</strong> pellet fuel. Pellets are small<br />

cylinders of compressed wood manufactured in <strong>the</strong> same type of machine as cattle feed and cat litter.<br />

They are free flowing clean and convenient <strong>to</strong> use. Over <strong>the</strong> past decade clean wood pellets have<br />

transformed <strong>the</strong> small scale wood heating market with a range of boilers and room heaters designed<br />

specifically for pellets.<br />

The best example of pellet production is <strong>the</strong> Balcas Sawmill in Nor<strong>the</strong>rn Ireland. This installation was<br />

built with grant aid from <strong>the</strong> Bioenergy Capital Grant Scheme, and comprises a 2.7 MWe CHP installation.<br />

The fuel for <strong>the</strong> CHP is taken from <strong>the</strong> poor quality bark and slab wood whilst <strong>the</strong> sawdust is dried using<br />

<strong>the</strong> heat rejected from <strong>the</strong> steam cycle. The dry sawdust is compressed in <strong>to</strong> pellets at <strong>the</strong> rate of 40,000<br />

<strong>to</strong>nnes per annum. An additional installation is being built <strong>by</strong> Balcas in Scotland that will deliver 100,000<br />

<strong>to</strong>nnes of pellets per annum.<br />

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Through <strong>the</strong> Balcas project several thousand homes and businesses in Ireland have converted <strong>to</strong> wood<br />

pellet heating, also facilitated <strong>by</strong> energy grants available from Sustainable Energy Ireland.<br />

Experience from Austria suggests that wherever pellets are introduced <strong>the</strong>y result in an increased uptake<br />

of wood heating and dominate <strong>the</strong> small boiler market.<br />

Graded waste wood chip<br />

Following <strong>the</strong> building of <strong>the</strong> two major power projects at Lockerbie and Wil<strong>to</strong>n a market has grown <strong>to</strong><br />

supply waste wood in chipped form <strong>to</strong> an accepted quality standard. In both cases wood recycling<br />

companies have set up dedicated reception and sorting centres at <strong>the</strong> power plant. In <strong>the</strong>se centres <strong>the</strong><br />

wood is sorted <strong>to</strong> remove contaminated material, shredded and chipped <strong>to</strong> a size distribution set <strong>by</strong> <strong>the</strong><br />

power plant owner.<br />

The above examples deal with virgin wood, that has not undergone any treatment. Use of waste wood is<br />

more challenging as it will likely have been chemically treated with preservatives, and so can only be<br />

used in WID compliant plants. We understand that E.ON have plans <strong>the</strong> build five power plant each<br />

25MWe fuelled <strong>by</strong> waste wood. 187<br />

The recycled wood industry is growing rapidly as pressure <strong>to</strong> remove organic material from waste streams<br />

increases at <strong>the</strong> same time as <strong>the</strong> demand for renewable fuels. 188 Opera<strong>to</strong>rs are becoming more<br />

experienced and are able <strong>to</strong> supply a range of fuel specifications depending on <strong>the</strong> degree of<br />

contamination and source. 189<br />

7.1.5 Standards for wood based fuels<br />

The rapid growth of biomass energy applications in Europe and <strong>the</strong> increases projected as a result of <strong>the</strong><br />

Renewable Energy Directive have created a need for a suite of standards for <strong>the</strong> characterisation and<br />

analysis of wood fuels. These have been developed on an accelerated timetable <strong>by</strong> CEN Technical<br />

Committee 355. The remit for this group <strong>to</strong> develop standards for all forms of solid biofuels in Europe,<br />

including wood chips, wood pellets, briquettes, logs, sawdust and straw bales.<br />

These standards allow all relevant properties of <strong>the</strong> fuel <strong>to</strong> be described, and include both normative information<br />

that must be provided about <strong>the</strong> fuel, and informative information that can be included but is not required. As well<br />

as <strong>the</strong> physical and chemical characteristics of <strong>the</strong> fuel as it is, CEN 335 also provides information on <strong>the</strong> source<br />

of <strong>the</strong> material.<br />

The Work Programme for TC 335 contains 30 Work Items, which are allocated <strong>to</strong> 5 Working Groups (WGs):<br />

• WG 1 Terminology, descriptions and definitions<br />

• WG 2 Fuel specifications, classes and quality assurance<br />

• WG 3 sampling and sample preparation<br />

• WG 4 Physical and mechanical test methods<br />

• WG 5 Chemical test methods<br />

All Technical Specifications for CEN 335 have now been published.<br />

CEN 335 includes solid biofuels originating from <strong>the</strong> following sources:<br />

• Products from agriculture and forestry;<br />

• Vegetable waste from agriculture and forestry;<br />

• Vegetable waste from <strong>the</strong> food processing industry;<br />

187 http://pressreleases.eon-uk.com/blogs/eonukpressreleases/archive/2008/07/15/1257.aspx<br />

188 Wood Recyclers Association, www.woodrecyclers.org<br />

189 http://www.woodrecyclers.org/


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• Wood waste, with <strong>the</strong> exception of wood waste which may contain halogenated organic compounds or<br />

heavy metals as a result of treatment with wood preservatives or coating, and which includes in<br />

particular such wood waste originated from construction and demolition waste;<br />

• Continued-fibrous vegetable waste from virgin pulp production and from production of paper from pulp, if<br />

it is co-incinerated at <strong>the</strong> place of production and heat generated is recovered;<br />

• Cork waste.<br />

Draft standards for CEN 355 are available for download from <strong>the</strong> Biomass Information Centre website. 190<br />

Germany is somewhat ahead of <strong>the</strong> UK in its use of waste wood for energy and has developed a grading system<br />

based on composition and origin. 191 This has gained some acceptance in <strong>the</strong> UK because of its practical nature.<br />

It is given below.<br />

Box 3: German Waste Wood Grading System<br />

Waste wood category A I:<br />

Waste wood in its natural state or only mechanically worked with, during use, was at<br />

most insignificantly contaminated with substances harmful <strong>to</strong> wood.<br />

Waste wood category AII:<br />

Bonded, painted, coated, lacquered or o<strong>the</strong>rwise treated waste wood with no<br />

halogenated organic compounds in <strong>the</strong> coating and no wood preservative.<br />

Waste wood category A III:<br />

Waste wood with halogenated organic compounds in <strong>the</strong> coating, with no wood<br />

preservatives.<br />

Waste wood category A IV:<br />

Waste wood treated with wood preservatives, such as railway sleepers, telephone masts,<br />

hop poles, vine poles as well as o<strong>the</strong>r waste wood which, due <strong>to</strong> its contamination,<br />

cannot be assigned <strong>to</strong> waste wood categories A I, A II or A III, with <strong>the</strong> exception of<br />

waste wood containing PCBs.<br />

Category A I includes sawmill co-products which also currently have a market in <strong>the</strong> UK as fuel for cofiring<br />

at coal power plants, fuel for o<strong>the</strong>r stand-alone biomass plants and raw material for a variety of<br />

competing markets, including animal bedding, horticultural use and, most significantly, <strong>the</strong> panel board<br />

mills. Sawmill co-product that has only been mechanically treated is treated as clean wood for <strong>the</strong><br />

purposes of combustion under <strong>the</strong> Waste Incineration Directive (WID). It is transported long distances<br />

across <strong>the</strong> UK and is priced competitively compared <strong>to</strong> virgin biomass fuels.<br />

Category A II includes residues from <strong>the</strong> production of furniture, kitchens etc. This product is usually<br />

disposed of <strong>to</strong> landfill or mass burn incineration at present. It is difficult <strong>to</strong> separate out <strong>the</strong> clean waste<br />

wood from <strong>the</strong> contaminated and E.ON, for example, would have <strong>to</strong> take it unsorted. This product should<br />

not come within <strong>the</strong> WID. However, it is impossible <strong>to</strong> protect it from contamination with fractions of waste<br />

that do come under WID and <strong>the</strong>refore <strong>the</strong> position is not clear cut. It is likely that <strong>the</strong> Environment<br />

Agency would regard <strong>the</strong> potential contamination issue as important and class any combustion process<br />

under WID.<br />

Category A III is treated as waste for <strong>the</strong> purposes of combustion under WID and any plant burning <strong>the</strong>se<br />

wastes would need <strong>to</strong> comply with WID as part of <strong>the</strong> conditions of its licence.<br />

190 http://www.biomassenergycentre.org.uk<br />

191 Ordinance on <strong>the</strong> Management of Waste Wood dated 15 August 2002<br />

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Table 54 Risks and barriers for wood fuel production<br />

Level of Risk Comment<br />

Technical Low Many projects for both pellet and chip worldwide.<br />

Social & Planning Medium Some current waste wood installations can be<br />

unsightly and “bad neighbours” creating noise<br />

dust and fire risks from large quantities of s<strong>to</strong>red<br />

waste wood.<br />

Sawmill based installations are positive due <strong>to</strong><br />

reduced transport of residue, job creation and<br />

low additional impact.<br />

Financial Medium Requires revenue from sale of fuel but market<br />

not well established.<br />

Waste wood derived fuel is still classed as a<br />

waste which may give problems with sale and<br />

use and hence price.<br />

Standards and agreed specifications are needed<br />

<strong>to</strong> make <strong>the</strong> fuel product a traded commodity.<br />

Attractiveness depends on <strong>the</strong> price of oil as well<br />

as incentives.<br />

These aspects should be resolved within <strong>the</strong><br />

next few years.<br />

Regula<strong>to</strong>ry Medium Waste wood derived fuel is still classed as a<br />

waste which may give problems with sale and<br />

use hence a reduced price.<br />

The legal status needs <strong>to</strong> be clarified. Standards<br />

would help <strong>to</strong> clarify definitions.<br />

Market depends upon incentives for heat and<br />

electricity <strong>the</strong>se can change due <strong>to</strong> extraneous<br />

fac<strong>to</strong>rs.<br />

These aspects should be resolved within <strong>the</strong><br />

next few years.<br />

7.1.6 Thermochemical fuels<br />

The purpose of <strong>the</strong>rmochemical processes is <strong>to</strong> produce a fuel with an increased energy density and<br />

physical and chemical properties that are both more consistent than <strong>the</strong> source material, and better<br />

matched <strong>to</strong> <strong>the</strong> requirements of <strong>the</strong> conversion technology.<br />

The fuels in this category are derived from lignocellulosic materials such as wood, crop residues, paper<br />

and board. The two main categories are<br />

Char, Oils and liquors from pyrolysis ei<strong>the</strong>r as separate liquid and char products or slurry of <strong>the</strong> two.<br />

Char is similar <strong>to</strong> coal in some respects being friable and having a relatively high calorific value,<br />

unfortunately it contains less than half of <strong>the</strong> energy value of <strong>the</strong> source material. Pyrolysis liquids are a<br />

mixture of complex carbohydrates and hydrocarbons that contain up <strong>to</strong> 70% of <strong>the</strong> energy of <strong>the</strong> source<br />

material. The relative proportions of char and liquids depend upon <strong>the</strong> reaction conditions in <strong>the</strong> process.<br />

Torrefied material. Torrefaction is <strong>the</strong> heat treatment of <strong>the</strong> material at temperatures between 200°C<br />

and 300°C that results in <strong>the</strong> removal of all moisture and a subsequent degradation and shrinkage of <strong>the</strong><br />

polymeric structure of <strong>the</strong> material. The changes produced <strong>by</strong> this process give an end product that is<br />

more energy dense, friable and less susceptible <strong>to</strong> take up moisture from its environment. These<br />

changes make it easier <strong>to</strong> transport, s<strong>to</strong>re and <strong>to</strong> use, particularly when pelletised. Torrefaction has <strong>the</strong><br />

advantage of producing a consistent fuel that retains over 90% of <strong>the</strong> energy of <strong>the</strong> source material.


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More information, such as <strong>the</strong> principles and <strong>the</strong> mass and energy balances for this route are given in<br />

references 179 and 180. 192,193<br />

At present <strong>the</strong>se fuels have only been proposed, none are currently produced from waste materials<br />

specifically as fuels, o<strong>the</strong>r than in research and development activities.<br />

Producing fuels with improved properties has benefits in terms of transport s<strong>to</strong>rage and use but <strong>the</strong>re is a<br />

penalty in resource use efficiency due <strong>to</strong> <strong>the</strong> heat used for <strong>the</strong> processing. Uslu et al have analysed <strong>the</strong><br />

efficiency of a range of supply chains using <strong>the</strong>rmochemical fuels and pellets manufactured from wood<br />

and come <strong>to</strong> <strong>the</strong> conclusion that <strong>to</strong>rrefaction with an energy efficiency of 94% required least energy whilst<br />

pyrolysis fuels with an efficiency of 64% are unlikely <strong>to</strong> be cost effective. 194 This analysis was carried out<br />

largely on wood feeds<strong>to</strong>cks and was targeted at life cycles involving long distance transport but<br />

none<strong>the</strong>less <strong>the</strong> broad principle should hold for most lignocellulosic materials. These conclusions were<br />

confirmed <strong>to</strong> some extent <strong>by</strong> Mortimer who found that <strong>the</strong>re was no advantage in using pyrolysis based or<br />

o<strong>the</strong>r upgraded fuels in <strong>the</strong> supply <strong>to</strong> a transport biofuels plant in <strong>the</strong> North East. 195<br />

7.1.7 Conclusions for Solid Recovered Fuels<br />

Producing a fuel type that provides consistent properties will enable more waste <strong>to</strong> be utilised as a fuel<br />

source for <strong>the</strong> generation of energy or fuels. The status of this area in <strong>the</strong> UK is:<br />

• Processes are commercially available for producing fuels from MSW and C&I waste using <strong>the</strong><br />

heat from composting as <strong>the</strong> energy from drying.<br />

• Processes for <strong>the</strong> production of fuels using <strong>the</strong>rmal energy <strong>to</strong> dry and sterilise waste are currently<br />

being demonstrated and may offer advantages in providing a more consistent product that is<br />

biologically stable.<br />

• Standards for fuels derived from MSW have been developed but are not widely used<br />

• The production of graded wood waste fuels has expanded rapidly in <strong>the</strong> last three years.<br />

Standards and codes are being adopted <strong>by</strong> <strong>the</strong> industry which is aiding acceptance and<br />

development.<br />

• Clean wood fuels are becoming widesp<strong>read</strong> and standards and codes are being adopted <strong>by</strong> <strong>the</strong><br />

industry.<br />

• Fuels prepared using pyrolysis and <strong>to</strong>rrefaction have been proposed but as yet not implemented<br />

commercially.<br />

192 Harold Boerrigter, Jaap Kiel, Patrick Bergman Proceedings of Thermalnet meeting April 2006 Lille<br />

http://www.<strong>the</strong>rmalnet.co.uk/docs/ECN_%20Torrefaction%20of%20Biomass%20as%20pretreatmentLille.pdf<br />

193 Report reference ECN-RX--05-180, Torrefaction for biomass upgrading, Patrick C.A. Bergman, Jacob H.A. Kiel<br />

Published at 14th European Biomass Conference & Exhibition,Paris, France, 17-21 Oc<strong>to</strong>ber 2005<br />

http://www.techtp.com/recent%20papers/ECN-Torrefaction%20for%20biomas%20upgrading%20-2005.pdf<br />

194 A. Uslu et al. / Energy 33 (2008) 1206–1223<br />

195 NNFCC project 09/016. Feb 2009<br />

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8 Supplying Energy from Waste <strong>by</strong><br />

Combustion<br />

In most European countries, <strong>by</strong> far <strong>the</strong> most common method of extracting energy from solid waste ei<strong>the</strong>r<br />

in untreated form or as a prepared fuel is combustion (or incineration) with energy recovery. Virtually all<br />

wastes can be treated <strong>by</strong> combustion and <strong>the</strong> technology is usually regarded as <strong>the</strong> default against which<br />

o<strong>the</strong>r options are measured.<br />

Combustion is a well established technology and <strong>the</strong> main technical challenges have been addressed.<br />

There remains however significant technical uncertainty surrounding <strong>the</strong> impact of <strong>the</strong> composition of <strong>the</strong><br />

waste on <strong>the</strong> performance of <strong>the</strong> heat exchange surfaces, particularly fouling and corrosion.<br />

O<strong>the</strong>r barriers remain, such as <strong>the</strong> largely negative public perception of such sites in some countries,<br />

including <strong>the</strong> UK.<br />

8.1 Process Description<br />

Untreated Waste<br />

Waste derived fuel<br />

Combustion<br />

Heat and/or<br />

Electricity<br />

Process Description<br />

A combustion system in its simplest form comprises two basic elements: a furnace where <strong>the</strong> fuel is<br />

burned and a boiler that recovers <strong>the</strong> heat from <strong>the</strong> combustion as steam or hot water.<br />

When <strong>the</strong> fuel enters <strong>the</strong> high temperature environment in a furnace it will first dry and <strong>the</strong>n decompose,<br />

or pyrolyse, in<strong>to</strong> volatile tars and gases and char components. These components <strong>the</strong>n react with air <strong>to</strong><br />

release <strong>the</strong> energy contained in <strong>the</strong> heating value of <strong>the</strong> fuel. This energy is released as radiation <strong>to</strong> <strong>the</strong><br />

walls of <strong>the</strong> furnace and in<strong>to</strong> a flow of hot flue gases <strong>to</strong> be captured <strong>by</strong> heat exchange surface in <strong>the</strong><br />

boiler that generates steam for use ei<strong>the</strong>r in <strong>the</strong> process, or <strong>by</strong> a turbine <strong>to</strong> produce electricity, or both<br />

(CHP).<br />

A furnace essentially consists of a box, lined ei<strong>the</strong>r with refrac<strong>to</strong>ry or water tubes, and a burner where <strong>the</strong><br />

air and fuel mix and burn. There are two main categories of burner for solid waste and biomass<br />

applications, grate and fluidised bed. The first has evolved from designs that have been used widely<br />

throughout <strong>the</strong> 19 th and 20 th centuries whilst <strong>the</strong> second is a fairly recent innovation from 1970’s onwards.<br />

Grate burners<br />

In grate-firing <strong>the</strong> fuel burns in a layer on a grid. Air for combustion is blown both through <strong>the</strong> grid and<br />

over <strong>the</strong> <strong>to</strong>p of <strong>the</strong> fuel layer. The processes of drying, pyrolysis and combustion of <strong>the</strong> volatiles and char<br />

take place sequentially as <strong>the</strong> material proceeds through <strong>the</strong> boiler on <strong>the</strong> grate. Various types of grids or<br />

grates have evolved <strong>to</strong> move <strong>the</strong> fuel through <strong>the</strong> boiler and eventually remove <strong>the</strong> ash. Some grates<br />

vibrate, some move slowly forward on chains whilst o<strong>the</strong>rs have a reciprocating action. Grates are<br />

reliable, but are considered somewhat inflexible and are designed <strong>to</strong> cope with a limited range of fuels.<br />

Experience in <strong>the</strong> UK has shown that high, and variable, moisture content fuels such as poultry litter can<br />

lead <strong>to</strong> uneven combustion and high dust emissions.


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Small industrial-commercial and domestic boilers are small grate burners that burn almost exclusively<br />

clean wood in <strong>the</strong> form of logs, chips and pellets. Logs are used mostly for domestic applications, pellets<br />

for domestic and commercial and chips for commercial <strong>to</strong> large commercial and industrial.<br />

Fluidised bed burners<br />

In a fluidised bed furnace, <strong>the</strong> fuel burns in a bed of sand or o<strong>the</strong>r mineral that is violently agitated <strong>by</strong> <strong>the</strong><br />

combustion air. The fuel is fed at a controlled rate <strong>to</strong> keep <strong>the</strong> temperature of <strong>the</strong> sand bed at 800 <strong>to</strong><br />

900°C. With moderate air velocities <strong>the</strong> bed has <strong>the</strong> appearance of a boiling liquid, hence <strong>the</strong> name<br />

bubbling fluidised bed (BFB). If a higher velocity is used <strong>the</strong> sand will be carried out of <strong>the</strong> furnace and<br />

must be recycled <strong>to</strong> <strong>the</strong> base via a cyclone – this is known as a circulating fluidised bed (CFB). Heat is<br />

removed and steam is raised <strong>by</strong> tubes in <strong>the</strong> bed of sand (not needed for biomass fuels), <strong>the</strong> walls of <strong>the</strong><br />

furnace and in <strong>the</strong> exhaust flue. This type of boiler is proving very popular for medium <strong>to</strong> large industrial<br />

boilers for coal and o<strong>the</strong>r solid fuels and is taking an increasing share of this market.<br />

A great advantage of <strong>the</strong> fluidised bed <strong>to</strong> <strong>the</strong> power plant opera<strong>to</strong>r is its fuel flexibility. This feature has<br />

been used <strong>to</strong> great advantage <strong>by</strong> CHP plants in <strong>the</strong> Nordic Countries, where it is common practice <strong>to</strong> fire<br />

wood chip, coal, peat, oil and wastes both <strong>to</strong>ge<strong>the</strong>r and separately. This flexibility is bought at <strong>the</strong> cost of<br />

greater complexity however and <strong>the</strong>y are unlikely <strong>to</strong> be cost effective lower output alternatives.<br />

Good modern examples of fluidised bed burners from <strong>the</strong> Bioenergy capital grants scheme are at<br />

Lockerbie (43MWe) and Wil<strong>to</strong>n (31MWe). Both are fuelled <strong>by</strong> a mix of forestry wood chip and graded<br />

waste wood from wood recycling operations.<br />

Steam Boilers<br />

There are two types of boiler in common usage, fire tube and water tube.<br />

Fire tube boilers, as <strong>the</strong> name suggests, transfer <strong>the</strong> heat from <strong>the</strong> fire <strong>to</strong> <strong>the</strong> water <strong>by</strong> passing <strong>the</strong> hot flue<br />

gasses through tubes inserted in a pressure vessel containing <strong>the</strong> boiling water. Typically <strong>the</strong> gas will<br />

pass backwards and forwards three times through <strong>the</strong> boiler – three tube passes. They are inexpensive<br />

and manufactured in volume. Typically <strong>the</strong> furnace supplier will purchase <strong>the</strong> boiler and adapt it <strong>to</strong> his<br />

system. Fire tube boilers are manufactured in sizes up <strong>to</strong> 50 <strong>to</strong>nnes steam/h and a typical steam<br />

pressure of 20bar, although 40bar is possible. They produce only saturated steam but a variant is<br />

available that allows for superheating <strong>by</strong> installing a heat exchanger after <strong>the</strong> second tube pass. This is a<br />

cost effective solution for industrial plants that require smaller turbines, typically 1 - 2MWe.<br />

Water tube boilers generate steam inside of tubes that are installed around <strong>the</strong> furnace and in banks<br />

across <strong>the</strong> flue gas. The temperatures and pressure of <strong>the</strong> steam can be much higher than in water tube<br />

boilers. Utility boilers can reach supercritical conditions. For large biomass boilers 520°C and 120 bar is<br />

not uncommon. Smaller units that might be appropriate for a CHP installation would have temperatures<br />

of 450°C and 50 bar. They can be manufactured in much larger sizes than fire tube boilers and tend <strong>to</strong><br />

overlap <strong>the</strong> <strong>to</strong>p end of <strong>the</strong> fire tube range.<br />

Grate burners can be installed with ei<strong>the</strong>r fire tube or water tube boilers. Fluidised beds are normally<br />

installed with water tube boilers.<br />

Control of emissions<br />

The combustion gases are cleaned <strong>by</strong> a sequence of process stages that remove particulates, acid gases<br />

and trace organic compounds such as dioxins and furans. The number of stages <strong>the</strong>ir type and<br />

complexity depends upon <strong>the</strong> composition of <strong>the</strong> waste, its legal classification under <strong>the</strong> Waste<br />

Incineration Directive and <strong>the</strong> size of <strong>the</strong> installation. The main species <strong>to</strong> be removed and abatement<br />

technologies are summarised below in Table 55.<br />

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Table 55 Pollution and <strong>the</strong> abatement methods for combustion of waste<br />

Pollutant Method of removal<br />

Particulates or aerosols Fabric or electrostatic filters, for smaller<br />

boilers and cleaner fuel cyclones or<br />

multiclone.<br />

Acid gasses mainly from sulphur and Dry or liquid carbonate wash or dry<br />

chlorine<br />

absorber.<br />

Dioxin and o<strong>the</strong>r organic compounds Active carbon absorber, can be combined<br />

with dry carbonate scrub<br />

Oxides of nitrogen. Injection of ammonia or urea in<strong>to</strong><br />

combustion zone. Catalytic removal from<br />

<strong>the</strong> flue gas.<br />

The main concerns on pollution from incinera<strong>to</strong>rs relate <strong>to</strong> <strong>the</strong> health effects of dioxins and o<strong>the</strong>r<br />

chemicals such as PCBs (poly chlorinated biphenyls) and PAHs (poly aromatic hydrocarbons). These<br />

compounds accumulate in body fat and are persistent.<br />

Dioxins are not present in nature. The term is loosely used <strong>to</strong> describe <strong>the</strong> whole family of <strong>to</strong>xic organic<br />

micro-pollutant emissions that may be formed during and after combustion. They have been associated<br />

with poorly run incineration in <strong>the</strong> past when chlorine containing wastes such as PVC, paper and card and<br />

treated wood were burnt, and this association persists.<br />

Understanding of how dioxins are formed has led <strong>to</strong> advances in process design and control that have<br />

resulted in <strong>the</strong> emissions from <strong>the</strong> incineration sec<strong>to</strong>r falling dramatically in <strong>the</strong> UK. Scientific studies<br />

have shown that <strong>the</strong> impact of emissions from an individual plant is very low. Dioxin emissions have<br />

reduced <strong>by</strong> more than 90% in <strong>the</strong> UK in <strong>the</strong> past 20 years. Never<strong>the</strong>less <strong>the</strong>re remains acute public<br />

concern over <strong>the</strong> issue, despite <strong>the</strong> fact that local authorities have access <strong>to</strong> this information.<br />

PCBs are classified as persistent in <strong>the</strong> environment and as being probably carcinogenic <strong>to</strong> humans.<br />

They have also been linked <strong>to</strong> sub-chronic effects such as reduced male fertility and long-term<br />

behavioural and learning impairment. They may originate from flexible plastic waste, paint waste, as well<br />

as transformers and capaci<strong>to</strong>rs. PAHs are a large group of chemical compounds and are carcinogenic.<br />

They may originate from waste wood, tar or fat waste for example.<br />

Sampling and analysis costs for all of <strong>the</strong>se compounds are high due <strong>to</strong> <strong>the</strong> specialised nature of <strong>the</strong><br />

equipment and trained labora<strong>to</strong>ry personnel required. This restricts <strong>the</strong> frequency of data collection. For<br />

this reason <strong>the</strong> public express concern regarding <strong>the</strong> reliability of data. A simpler, on-line test would be<br />

more satisfac<strong>to</strong>ry but due <strong>to</strong> <strong>the</strong> nature of dioxins this is a long way off.<br />

Smaller installations burning wood that do not have particulate removal equipment have also given rise <strong>to</strong><br />

concern recently. This is due <strong>to</strong> <strong>the</strong> nature of emissions from wood firing. The ash composition contains<br />

alkali components that vaporise at <strong>the</strong> furnace temperature <strong>to</strong> later condense in <strong>the</strong> cold atmosphere as<br />

aerosols with a size that is respirable. There is a similar problem with condensable organics in batch fed<br />

wood combustion devices where poor combustion control allows <strong>the</strong> formation of aerosols of organic<br />

compounds and soot. These are particularly worrying as <strong>the</strong>y contain carcinogenic materials such as<br />

furans and aromatics. This is only likely <strong>to</strong> be a problem in urban areas where <strong>the</strong> aggregate effect of<br />

several installations in a small area coupled with o<strong>the</strong>r sources such as diesel traffic could give<br />

unacceptable impacts. Local Authorities are being issued with revised guidelines on this issue and this<br />

should resolve <strong>the</strong> situation.<br />

The ash leaves <strong>the</strong> process as two distinct streams – bot<strong>to</strong>m ash that falls out of <strong>the</strong> combustion grate or<br />

bed, and fly ash that is separated from <strong>the</strong> flue gases. Bot<strong>to</strong>m ash is considered <strong>to</strong> be inert and, after <strong>the</strong><br />

separation of metals, is ei<strong>the</strong>r disposed of <strong>to</strong> general landfill or used as aggregate. Fly ash, however, can<br />

contain heavy metal contamination and, with certain chlorine containing wastes, dioxin so must be


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disposed of in a controlled landfill site. Recent European practice involves melting fly ash <strong>to</strong> form a glass<br />

that reduces <strong>the</strong> mobility of <strong>the</strong> metal ions and destroys dioxin. Following this treatment <strong>the</strong> ash can be<br />

used as aggregate or filler.<br />

Impact of waste composition on boiler performance<br />

There are two main impacts that must be managed <strong>by</strong> <strong>the</strong> designers and opera<strong>to</strong>rs of waste combustion<br />

plant; acid gas and ash fouling.<br />

Chlorine is always present in mixed waste streams and derives largely from plastics but also from paper<br />

and card. The chorine is converted in<strong>to</strong> hydrochloric acid in <strong>the</strong> combustion chamber, and this can cause<br />

excessive corrosion in <strong>the</strong> boiler, particularly at high temperatures. Restricting <strong>the</strong> temperature and<br />

pressure of <strong>the</strong> steam produced <strong>by</strong> <strong>the</strong> incinera<strong>to</strong>r limits <strong>the</strong> corrosion risk but also restricts <strong>the</strong> electrical<br />

efficiency that can be achieved.<br />

Circulating fluidised bed combus<strong>to</strong>rs have an advantage in treating wastes with a high chlorine content in<br />

that <strong>the</strong> high temperature boiler surface can be located in <strong>the</strong> circulating bed material where <strong>the</strong> chlorine<br />

concentration is lower.<br />

The oxides and salts of silicon and alkali metals are present in biomass derived wastes <strong>to</strong> a much larger<br />

extent than fossil fuels. The content increases with <strong>the</strong> proportion of annual growth material in <strong>the</strong> fuel.<br />

Thus, straw and o<strong>the</strong>r annual crop residues contain large quantities as does <strong>the</strong> bark and outer layers of<br />

trees. These components have low melting points that can lie below <strong>the</strong> temperature of <strong>the</strong> furnace, <strong>the</strong>y<br />

also have a propensity <strong>to</strong> form low melting point eutectic mixtures with o<strong>the</strong>r ash components. The liquid<br />

ash can adhere <strong>to</strong> heat transfer surfaces causing a reduction in output, sites for corrosion, and<br />

occasionally physical damage. Fluidised beds are also susceptible <strong>to</strong> agglomeration and eventual<br />

sintering and fusing due <strong>to</strong> <strong>the</strong> sticky nature of soft and liquid ash.<br />

Problems caused <strong>by</strong> ash chemistry are some of <strong>the</strong> most intractable in <strong>the</strong> industry and require <strong>the</strong><br />

application of substantial knowledge and experience in sourcing and blending feeds<strong>to</strong>cks and instituting<br />

regular boiler cleaning procedures. Suppliers of fluidised bed boilers have learned <strong>to</strong> manage <strong>the</strong><br />

chemistry of <strong>the</strong>ir bed materials <strong>to</strong> avoid low melting point eutectics <strong>by</strong> <strong>the</strong> addition of materials such as<br />

dolomite.<br />

A comprehensive review and a discussion of best practice for waste combustion is given in <strong>the</strong> supporting<br />

documentation for <strong>the</strong> Waste Incineration Directive 196<br />

Co-firing biofuels with fossil fuels<br />

The concept of co-firing biofuels with coal is one means of increasing <strong>the</strong> combustion of biomass in an<br />

existing power plant without incurring excessive capital costs. This approach has received increased<br />

attention recently, particularly in Denmark, <strong>the</strong> Ne<strong>the</strong>rlands and <strong>the</strong> US. The details of over 300 co-firing<br />

installations can be found on <strong>the</strong> IEA Bioenergy Agreement Task 32 database of co-firing installations. 197<br />

The way in which biomass is fired depends on <strong>the</strong> quantities involved. Where biomass quantities are<br />

small (2- 5%), <strong>the</strong> biomass is mixed with <strong>the</strong> coal at <strong>the</strong> mill inlet. Where biomass constitutes 5-25% of <strong>the</strong><br />

<strong>to</strong>tal fuel, shredded biomass is fired through dedicated burners. Beyond <strong>the</strong> 25% level, new concepts will<br />

be needed because combustion of that amount of biomass will have a substantial impact on both furnace<br />

and ash behaviour. Current opinion within <strong>the</strong> industry is that this will probably mean converting <strong>the</strong> fuel<br />

<strong>to</strong> gas.<br />

Current practice in <strong>the</strong> UK is <strong>to</strong> receive <strong>the</strong> fuel on site in <strong>the</strong> form of pellets that are stable, easy <strong>to</strong><br />

handle and break easily in <strong>the</strong> coal mills.<br />

196 European Integrated Pollution and Prevention and Control Bureau Waste Incineration Bref (08.06) http://eippcb.jrc.es/pages/FActivities.htm<br />

197 http://www.ieabcc.nl/database/cofiring.php<br />

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8.2 Review of UK and international waste combustion<br />

practice<br />

8.2.1 Combustion of MSW for energy in <strong>the</strong> UK<br />

There are a number of MSW energy recovery plants in operation in <strong>the</strong> UK using combustion technology,<br />

and numerous examples worldwide.<br />

In <strong>to</strong>tal in <strong>the</strong> UK, 45.1% (12.9 million <strong>to</strong>nnes) of MSW had value recovered from it in 2007/08 (including<br />

recycling, composting, energy from waste and fuel manufacture), a rise from 41.8% (12.2 million <strong>to</strong>nnes)<br />

in 2006/07. It has been estimated that Energy from Waste (EfW) capacity in <strong>the</strong> UK in 2007 reached 4.9<br />

million <strong>to</strong>nnes. 198<br />

The vast majority of sites in <strong>the</strong> UK that combust mixed waste and recover energy use MSW. This is<br />

because <strong>the</strong> long term contracts available from local authorities for waste management enable <strong>the</strong><br />

development of what are very high capital cost plants. However, <strong>the</strong>re are some merchant plants being<br />

proposed in <strong>the</strong> UK and Lakeside is one of <strong>the</strong> first of <strong>the</strong>se. These plants are being developed without<br />

MSW contracts, and, although MSW will probably dominate input, <strong>the</strong>se plants will also have more<br />

flexibility <strong>to</strong> take commercial and industrial waste streams.<br />

Table 56 Current EfW of MSW <strong>to</strong> generate electricity 199<br />

Site and<br />

Opera<strong>to</strong>r<br />

Edmon<strong>to</strong>n, SITA<br />

/ London Waste<br />

Alling<strong>to</strong>n<br />

Quarry, Kent<br />

Enviropower Ltd<br />

Coventry,<br />

Coventry and<br />

Solihull Waste<br />

Disposal<br />

SELCHP, Onyx<br />

Selchp<br />

Tyseley, Veolia<br />

Environmental<br />

Services<br />

Sheffield ERF,<br />

Veolia ES<br />

Billingham,<br />

Cleveland WTE,<br />

Sita UK<br />

Marchwood,<br />

Veolia<br />

Environmental<br />

Location Quantity of<br />

MSW<br />

<strong>to</strong>nnes p.a.<br />

Energy<br />

Generation<br />

Operational<br />

North London 500,000 55MWe 1989<br />

Kent 500,000 with<br />

separation of<br />

65,000 t for<br />

recycling.<br />

50 MWe<br />

Warwickshire 250,000 20 MWe and<br />

14.5 MWe<br />

2007<br />

2000<br />

Middlesex 420,000 30 MWe 1994<br />

Warwickshire 350,000 28 MWe<br />

(25MWe<br />

exported <strong>to</strong><br />

grid)<br />

Sheffield 225,000 19MWe and<br />

Teesside 350,000 being<br />

increased <strong>to</strong><br />

Southamp<strong>to</strong>n,<br />

Hampshire<br />

60MWh<br />

19 MWe<br />

1996<br />

2007<br />

1998<br />

475,400<br />

165,000 15MWe 2006<br />

198 Mass burn begins its big breakthrough, ENDS Report 394, November 2007, p.28-31.<br />

199 Waste <strong>to</strong> Energy Plants in <strong>the</strong> UK, http://www.industcards.com/wte-uk.htm, EPER UK Facilities Report, 2001,<br />

http://www.eper.ec.europa.eu/eper2/Activity_FacilityList.asp?year=2001&area=UK&id=17&EmissionAir=on


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Site and<br />

Opera<strong>to</strong>r<br />

Services<br />

Marchwood,<br />

Veolia<br />

Environmental<br />

Services<br />

Portsmouth,<br />

Veolia<br />

Environmental<br />

Services<br />

Havant, Veolia<br />

Environmental<br />

Services<br />

S<strong>to</strong>ke Sideway,<br />

S<strong>to</strong>ke on Trent<br />

Bol<strong>to</strong>n, Greater<br />

Manchester<br />

Waste Ltd<br />

Kirklees Waste<br />

<strong>to</strong> Energy Plant,<br />

Sita UK<br />

Baldovie,<br />

Dundee EfW<br />

Plant<br />

Dudley, Dudley<br />

Waste Services<br />

Ltd<br />

Location Quantity of<br />

MSW<br />

<strong>to</strong>nnes p.a.<br />

Energy<br />

Generation<br />

Operational<br />

Hampshire 165,000 14 MWe 2004<br />

Hampshire 165,000 14 MWe 2005<br />

Portsmouth,<br />

Hampshire<br />

165,000 14MWe 2006<br />

Staffordshire 200,000 12.5MWe 1997<br />

Lancashire 120,000 10 MWe 2000<br />

refurbishment<br />

Huddersfield 136,000 9MWe 2002<br />

Dundee,<br />

Scotland<br />

120,000 of<br />

course SRF,<br />

from<br />

MSW and C&I<br />

8MWe<br />

1999<br />

Staffordshire 90,000 7.4 MWe 1998<br />

Chineham,<br />

Veolia ES<br />

Hampshire Ltd<br />

Hampshire 90,000 7 MWe 2003<br />

Wolverhamp<strong>to</strong>n West 105,000 7MWe 1998<br />

Isle of Man EfW<br />

Plant, Sita UK<br />

Grims<strong>by</strong>,<br />

NewLincs<br />

Development<br />

Ltd<br />

Midlands<br />

Isle of Mann 60,000<br />

including tyres<br />

North East<br />

Lincolnshire<br />

6MWe (5MW<br />

exported <strong>to</strong><br />

grid)<br />

56,000 3.45 MWe<br />

and 3 MWh<br />

as CHP<br />

2005<br />

2004<br />

Estimations of energy efficiency for each plant are difficult <strong>to</strong> make as such figures are not <strong>read</strong>ily<br />

available and <strong>the</strong> waste input may vary, affecting <strong>the</strong> efficiencies.<br />

It is likely that <strong>the</strong> number of EfW combustion plants will increase in <strong>the</strong> future. To meet <strong>the</strong> UK’s 2013<br />

and 2020 landfill diversion targets it has been estimated that an additional 8.5 million <strong>to</strong>nnes of annual<br />

processing capacity for MSW alone will be required. 200 It is likely that a proportion of this will be as EfW<br />

plants with potentially 25% of MSW going <strong>to</strong> EfW eventually.<br />

200 Waste Infrastructure Delivery Programme (WIDP) Action Plan, Defra, http://www.defra.gov.uk/environment/waste/wip/widp/documents/widp-<br />

actionplan.pdf<br />

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Although using waste as a resource for energy generation is likely <strong>to</strong> increase, <strong>the</strong> output of <strong>the</strong> UK’s EfW<br />

plants above is small compared <strong>to</strong> <strong>the</strong> energy generated through traditional methods such as coal power<br />

stations. The sum of output described above is 395MW, where as Britain’s traditional power stations’<br />

output was 75,000MW in 2007. 201<br />

Four new EfW plants (with associated recycling and reprocessing facilities) are planned for London in <strong>the</strong><br />

near future, based on <strong>the</strong> Mayor of London's Waste Strategy. 202 These are: Dagenham, Newhaven (in<br />

East Sussex), Lakeside and Belvedere. The Dagenham proposal includes a proposed gasification plant<br />

<strong>to</strong> process 100,000 <strong>to</strong>nnes of waste each year and generate 15MW of electricity. Contracts between<br />

Shanks, <strong>the</strong> opera<strong>to</strong>r, and Ford, <strong>the</strong> beneficiary, have been signed but construction has been delayed.<br />

The Newhaven site has <strong>full</strong> planning permission and it is intended that <strong>the</strong> steam produced will be used<br />

for heat energy. 203 The Lakeside EfW Ltd site will be capable of handling 410,000 <strong>to</strong>nnes of waste per<br />

annum and is expected <strong>to</strong> open in July 2009, 204 while <strong>the</strong> Belvedere site in South East London is<br />

expected <strong>to</strong> process 600,000 <strong>to</strong>nnes per annum of waste and generate 66MW of electricity.<br />

In addition INEOS Chlor on Merseyside has permission <strong>to</strong> build a site capable of consuming 800,000<br />

<strong>to</strong>nnes of stabilised fuel from municipal waste, generating 100MW of electricity and 360MW of heat <strong>to</strong> be<br />

used largely on <strong>the</strong> chemicals site.<br />

International Situation<br />

The numbers of EfW plants world-wide continues <strong>to</strong> grow. Several countries in Europe, for example<br />

Denmark and Germany, have a strong his<strong>to</strong>ry of incineration, and <strong>the</strong> process is widely accepted <strong>by</strong> <strong>the</strong><br />

public. Such countries have found it relatively easy <strong>to</strong> move <strong>to</strong> EfW plants in terms of public perception,<br />

and as such use of EfW tends <strong>to</strong> be more widesp<strong>read</strong>.<br />

Currently <strong>the</strong>re are at least 91 sites throughout Western Europe that use MSW as <strong>the</strong> main fuel source for<br />

EfW combustion plants. Some of <strong>the</strong>se sites augment <strong>the</strong> MSW with bio-solids, wood, straw, and hospital<br />

waste depending on <strong>the</strong> site. World wide <strong>the</strong>re are at least 154 industrial scale waste <strong>to</strong> energy plants, a<br />

considerable number are in <strong>the</strong> USA, while China and Taiwan also have several each.<br />

Japan has many functioning EfW facilities as well as numerous straight incinera<strong>to</strong>rs. This is due <strong>to</strong> <strong>the</strong><br />

policy of waste minimisation that has been pursued for a number of decades, due <strong>to</strong> <strong>the</strong> limited land<br />

space. Only recently has deriving energy from <strong>the</strong> waste incineration process become a priority. Of<br />

Japan’s 1,301 incinera<strong>to</strong>rs in 2006, 293 generated electricity (7,190 GWh per annum). 205 Of <strong>the</strong>se<br />

facilities 7.4% do not carry out direct incineration, but convert waste <strong>to</strong> energy and fuels via o<strong>the</strong>r<br />

technologies, 206 which represents a 5-fold increase between 2001and 2006. 205 Such technologies are<br />

discussed below.<br />

8.2.2 Biomass CHP Plant for Commercial Food Waste<br />

In Widnes, Cheshire a combustion biomass CHP plant is operated <strong>by</strong> PDM, that is heavily utilised <strong>by</strong> 28<br />

Sainsbury’s s<strong>to</strong>res in Scotland, for disposal of 56,000 <strong>to</strong>nnes of commercial food waste. 207 The excess<br />

electricity generated is fed in<strong>to</strong> <strong>the</strong> grid, and <strong>the</strong> heat produced utilised <strong>by</strong> an adjacent chemicals<br />

company. Meat is separated for rendering and packaging for recycling before <strong>the</strong> waste is burnt.<br />

Sainsbury’s intends <strong>to</strong> extend <strong>the</strong> scheme <strong>to</strong> all s<strong>to</strong>res, sending additional material <strong>to</strong> <strong>the</strong> CHP biomass<br />

201 Giant offshore wind farms <strong>to</strong> supply half of UK power, The Sunday Times, 9 th December 2007.<br />

202 London Development Agency Press Release 2007, http://www.lda.gov.uk/server/show/ConWebDoc.2127<br />

203 Newhaven Incinera<strong>to</strong>r Clears Final Hurdle, 17.03.09, LetsRecycle.com<br />

http://www.letsrecycle.com/do/ecco.py/view_item?listid=37&listcatid=217&listitemid=31241<br />

204 Lakeside EfW Project Update, Viridor Waste Management, http://www.viridor-waste.co.uk/lakeside-energy-from-waste-project-update<br />

205 The status of MSW Management, 2005, http://www.env.go.jp/press/press.php?serial=8277<br />

206 Japan's waste management 2006, published September 2008, Department of Environment Japan,<br />

http://www.env.go.jp/recycle/waste_tech/ippan/h18/data/disposal2.doc<br />

207 ENDS Report 409, February 2009, p.18-19, Supermarkets burn food waste as anaerobic digestion shortage bites.


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site at Hartshill, near Nunea<strong>to</strong>n. Asda is using a similar programme for 20 of its s<strong>to</strong>res, sending some<br />

waste <strong>to</strong> Veolia’s CHP site in Sheffield (included in Table 56 above).<br />

PDM have also received planning permission for a £25 million 150,000 <strong>to</strong>nnes per annum biomass plant<br />

close <strong>to</strong> <strong>the</strong> above facility in Widnes.<br />

8.2.3 Utilising Wood - C&D Waste, Sawmill products, Forestry Residues<br />

Utilising forestry residues is largely carried out on a local scale, with clean wood being used in small scale<br />

biomass boilers.<br />

In <strong>the</strong> UK a significant amount of waste wood is used within <strong>the</strong> wood working industry. For example,<br />

wood waste may be used at furniture manufacturing sites <strong>to</strong> generate process heat. The level of<br />

utilisation of such a resource is unpublished, but it has been estimated that <strong>the</strong>re are at least 275 smallscale<br />

wood-burning boilers in <strong>the</strong> UK (0.4 – 3MW), consuming 223,500 <strong>to</strong>nnes of wood each year in <strong>the</strong><br />

furniture industry. 208 Such figures do not include throughputs for <strong>the</strong> larger scale boilers used <strong>by</strong> <strong>the</strong><br />

panel board manufacturing industry.<br />

One instance of waste wood being processed for utilisation is <strong>by</strong> Wood Pellet Energy Ltd in County<br />

Durham, which collects wood waste from business and households in <strong>the</strong> region. They convert wood<br />

waste, which would o<strong>the</strong>rwise go <strong>to</strong> board manufacturing, <strong>to</strong> fuel pellets. Annual production is<br />

approximately 12,000 <strong>to</strong>nnes, with output expected <strong>to</strong> rise. The pellets produced from ‘clean’ waste wood<br />

are <strong>the</strong>n used <strong>by</strong> Durham County Council <strong>to</strong> heat twelve of its schools, schools in Northumberland and<br />

North Yorkshire and parts of Leeds University. Pellets that have been produced from treated wood can<br />

only be used in boilers that are WID compliant such as at Sembcorp Biomass Power Station at Teesside.<br />

E.ON received permission in 2008 <strong>to</strong> build an energy plant at Blackburn Meadows in Sheffield, that uses<br />

recycled wood as <strong>the</strong> fuel source. Construction is expected <strong>to</strong> begin in 2009, with <strong>full</strong> commercial<br />

operation expected in 2011. It is intended <strong>to</strong> generate 25 MW of electricity. 209<br />

Table 57 Wood utilising energy generation systems<br />

Site and<br />

Opera<strong>to</strong>r<br />

Port Talbot<br />

biomass<br />

power station<br />

Eccleshall<br />

Biomass<br />

energy<br />

RSPB Old<br />

Moor<br />

Sheffield<br />

Road Flats<br />

(166 flats),<br />

Barnsley<br />

Metropolitan<br />

Borough<br />

Council<br />

Location Quantity of Wood Generation<br />

Capacity<br />

Port Talbot,<br />

South Wales<br />

120k <strong>to</strong>nnes forestry and<br />

sawmill residues.<br />

13.5MWe<br />

Electricity<br />

only<br />

Staffordshire 20k <strong>to</strong>nnes wood chip and<br />

miscanthus<br />

2.3MWe<br />

South Yorkshire 3 <strong>to</strong>nnes of fuel (12m 3 )<br />

delivered twice per week<br />

during winter, once every<br />

two weeks during <strong>the</strong><br />

summer.<br />

Barnsley 100m 3 of fuel gives 1 weeks<br />

supply in winter and 3 <strong>to</strong> 4<br />

weeks in summer.<br />

208 Benchmarking wood waste combustion, BFM, 2005,<br />

http://www.bfmenvironment.co.uk/images/BFM%20Wood%20combustion%20benchmarking%20-%20<strong>full</strong>1.pdf<br />

209 E.ON, Blackburn Meadows, http://www.eon-uk.com/generation/1490.aspx<br />

100kW<br />

Heating<br />

1 x 320 kW<br />

and 1 x 150<br />

kW<br />

providing<br />

space and<br />

water<br />

heating<br />

Operational<br />

2008<br />

2007<br />

2004<br />

2004<br />

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Bio-energy Capital Grants Scheme<br />

The Bioenergy Capital Grants Scheme (BEGS) was launched in 2002. Four funding rounds have been<br />

held over <strong>the</strong> past five years <strong>to</strong> support various aspects of <strong>the</strong> Bioenergy sec<strong>to</strong>r. DTI and <strong>the</strong> Lottery<br />

funded <strong>the</strong> first two rounds and Defra <strong>the</strong> third and fourth. The fifth round funded <strong>by</strong> DECC was launched<br />

in Dec 2008 and <strong>the</strong> successful applicants have just been announced.<br />

The objectives are focused on building <strong>the</strong> basis of an industry, and providing a learning experience. This<br />

has directed <strong>the</strong> scheme <strong>to</strong>wards a broad portfolio of projects that captures a wide range of technologies<br />

and companies.<br />

The scheme has produced <strong>the</strong> following highlights:<br />

• Two major power plant projects in operation at Lockerbie and Middlesbrough see Box 4.<br />

• Several electricity/CHP installations in operation located in South Wales, Nor<strong>the</strong>rn Ireland, and<br />

Staffordshire including anaerobic digestion.<br />

• 1 x 5.4 MWe industrial CHP at a brewery. Replications are al<strong>read</strong>y being planned across <strong>the</strong><br />

sec<strong>to</strong>r.<br />

• 1 x 1.4 MWe gasification CHP <strong>to</strong> supply a University Campus.<br />

• A core industry of suppliers installing biomass boilers with over 400 installations so far.<br />

• Parallel generation of local wood fuel suppliers extracting local woodlands and resources. Each<br />

region now has several suppliers.<br />

• Nine projects with local authorities that demonstrate public sec<strong>to</strong>r leadership in developing carbon<br />

abatement strategies. For example, Nottingham is converting all <strong>the</strong>ir schools <strong>to</strong> wood heating.<br />

• Started UK pellet fuel industry <strong>by</strong> supporting <strong>the</strong> Balcas sawmill CHP plant in Nor<strong>the</strong>rn Ireland,<br />

producing 40k <strong>to</strong>nnes pellets per annum. Balcas are now replicating this, at double <strong>the</strong> size, in<br />

Scotland based on <strong>the</strong> experience.<br />

• Initiated a new industry in recovered wood fuel in <strong>the</strong> North East and North West <strong>by</strong> providing a<br />

market for over 200k <strong>to</strong>nnes per annum. E.ON and o<strong>the</strong>rs are now planning fur<strong>the</strong>r installations<br />

<strong>to</strong> use this resource.<br />

• Average cost of carbon abatement: £132 of Government funding per annual <strong>to</strong>nne abated in later<br />

rounds.


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Box 4: New UK Projects burning graded waste wood supported <strong>by</strong> <strong>the</strong> Bioenergy<br />

Capital Grants Scheme<br />

Wil<strong>to</strong>n 10: Wood Burning Power Station<br />

Wil<strong>to</strong>n 10 at Teeside, Middlesborough, was <strong>the</strong> UK’s first large scale biomass power station,<br />

built at a cost of £60m, and commencing operation in 2007. It is owned and run <strong>by</strong> SembCorp<br />

Utilities, using 300,000 <strong>to</strong>nnes of wood as <strong>the</strong> fuel source and sourcing this material from a<br />

mixture of waste wood from civic amenity sites, C&D sites and waste firms (40%), primary<br />

processing products (20%), arboricultural arisings sourced from <strong>the</strong> north east region’s<br />

forestry commission and dedicated coppice grown as an energy crop. All material is s<strong>to</strong>red<br />

and chipped on a neighbouring site <strong>to</strong> <strong>the</strong> power station.<br />

The power station uses a bubbling fluidised bed boiler, capable of handling <strong>the</strong> high moisture<br />

fuel and <strong>the</strong> ash produced from <strong>the</strong> wood. The Siemens steam turbine is used <strong>to</strong> generate<br />

33MW of electricity, which is sold directly <strong>to</strong> <strong>the</strong> grid. In addition 10MWth of steam is available<br />

and this is used <strong>by</strong> <strong>the</strong> sites district heating steam circuit, largely as process heat.<br />

Steven’s Croft: Wood Burning Power Station<br />

Steven's Croft, in Lockerbie, Scotland, is currently <strong>the</strong> UK’s largest biomass power station. It<br />

is owned and run <strong>by</strong> E.ON, who opened it in 2008. The cost of building was £90m including<br />

£18m from <strong>the</strong> Big Lottery Grant.<br />

It utilises 480,000 <strong>to</strong>nnes of wood each year of which is sourced principally from forestry coproducts<br />

from within a 60 mile radius, up <strong>to</strong> 20% recycled wood from wood product<br />

manufacture, and some short rotation coppice willow. It is intended that <strong>by</strong> 2012 90,000<br />

<strong>to</strong>nnes of wood will be sourced from locally grown willow. The output is 44MW of electricity <strong>to</strong><br />

<strong>the</strong> national grid.<br />

There are a considerable number of facilities that use forestry residues and sawmill co-products<br />

internationally. The table below signposts <strong>to</strong> sources of information regarding <strong>the</strong> most important<br />

markets internationally.<br />

Table 58 Forestry waste <strong>to</strong> energy facilities<br />

Country Feeds<strong>to</strong>ck Comments<br />

Finland 210 Forestry<br />

residues and<br />

saw mill coproducts<br />

Finland has several power plants that utilise <strong>the</strong> widely available<br />

resource of wood, with much of <strong>the</strong> resource coming from forestry<br />

residues and saw-mill co-products. Many of <strong>the</strong>se are CHP<br />

systems. In addition Finland has two plants that are fuelled <strong>by</strong> <strong>the</strong><br />

waste from paper processing plants – called Black Liquor, <strong>the</strong><br />

lignin and hemicellulose fragments of wood. The generation<br />

capacity of <strong>the</strong>se plants ranges from 17-240MW.<br />

The CHP plant of Pietarsaari (Alholmens Kraft Power) is <strong>the</strong><br />

world’s largest biofuel CHP plant with an output of 240 MW of<br />

electricity, 100 MW process steam and 60 MW of district heat. It<br />

began operating in 2001 and processes 150,000 - 200,000m 3 of<br />

logging residues (as well as peat and black liquors from <strong>the</strong> paper<br />

mill). 211<br />

210 The World’s largest biofuel CHP plant, http://www.itebe.org/telechargement/revue/Revue5/Revue5-UK/RevueBE5-UK-p42.pdf<br />

211 Alholmens Kraft, http://www.metso.com/corporation/home_eng.nsf/FR?ReadForm&ATL=/corporation/about_eng.nsf/ WebWID/WTB-<br />

071102-2256F-C513C<br />

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Country Feeds<strong>to</strong>ck Comments<br />

Italy 212 Forestry<br />

Residues<br />

Italy has five biomass power stations that burn wood and make<br />

some use of Forestry residues.<br />

One is <strong>the</strong> CHP system in Pozzilli, opened in 1997,which takes<br />

70,00 – 80,000 <strong>to</strong>nnes per annum of wood residues as well as<br />

agricultural residues (hazelnut shells, olive kernels, fruit s<strong>to</strong>nes,<br />

pine cone seed residues) <strong>to</strong> generate an output of 9.8 MW.<br />

Sweden Wood waste Sweden has 3 biomass power plants that burn waste wood, and<br />

Iwakuni,<br />

Japan 213<br />

Anderson,<br />

USA 214,215<br />

8.2.4 Straw<br />

Forestry<br />

Residues<br />

Forestry<br />

Residues<br />

one of <strong>the</strong>se also burns waste tyres.<br />

A co-generation station that has used 90,000 <strong>to</strong>nnes per annum of<br />

logging residues since 2006. Operated <strong>by</strong> First Energy Service<br />

Company Ltd. The first biomass plant of larger than 10MW.<br />

Operated <strong>by</strong> Signal Shasta Energy Co it has been operational<br />

since 1989 and utilises 750,000 <strong>to</strong>nnes per annum of mill waste<br />

and forest residues, with a generation capacity of 3 x 18MW.<br />

There is one straw burning power station in <strong>the</strong> UK, <strong>the</strong> Elean station in Ely, Cambridgeshire, constructed<br />

<strong>by</strong> Energy Power Resources Ltd (EPRL) and in operation since 2000. 216 This plant uses 200,000 <strong>to</strong>nnes<br />

per annum, generates 38MW of electricity and cost £60M <strong>to</strong> build. It is also capable of burning a range of<br />

o<strong>the</strong>r bio-fuels. This plant uses a vibrating grate with conventional steam cycle. The opera<strong>to</strong>r requires<br />

relatively dry straw, so bales over 650 kg at 16% moisture content command an average price while <strong>the</strong>re<br />

is a price penalty for bales that are ei<strong>the</strong>r less dense than this or have a higher moisture content. EPRL<br />

have developed moni<strong>to</strong>ring equipment <strong>to</strong> enable <strong>the</strong>m <strong>to</strong> assess moisture and density as <strong>the</strong> bales enter<br />

<strong>the</strong> plants.<br />

Straw has a high potassium and sodium salt content which can lead <strong>to</strong> increased deposits and corrosion<br />

when using straw.<br />

Small–scale straw burning boilers are available in <strong>the</strong> UK, and it is estimated that a fur<strong>the</strong>r 17,000 <strong>to</strong>nnes<br />

per annum are used in small-scale on farm schemes. These boilers are used for a number of purposes,<br />

including heating farmhouses and associated buildings, drying grain and heating swimming pools. Many<br />

of <strong>the</strong>se plants were built as a result of grants for straw heat and power in <strong>the</strong> 1980s. However, since this<br />

Government programme s<strong>to</strong>pped, a number of <strong>the</strong> plants have been converted <strong>to</strong> wood. This is because<br />

of <strong>the</strong> problems with s<strong>to</strong>rage and handling of straw, and <strong>the</strong> problems surrounding ash corrosion.<br />

There are no schemes in <strong>the</strong> UK <strong>to</strong> co-fire straw, although some power stations are licensed <strong>to</strong> take it.<br />

Straw power plants have been built in Denmark, where <strong>the</strong>re are targets <strong>to</strong> drive this development. The<br />

Danish work has demonstrated <strong>the</strong> feasibility of large-scale co-firing of straw.<br />

212 Production of energy from biomass residues in <strong>the</strong> CHP plant of Pozzilli, Italy, 2002, http://www.tekes.fi/OPET/pdf/Energonut_IT.pdf<br />

213 Circulating Fluidized Bed Power Plant, JFE Engineering Corporation, http://www.jfe-eng.co.jp/en/en_product/environment/environment2121.html<br />

214 http://www.industcards.com/biomass-usa-ca.htm<br />

215 http://www.sl<strong>the</strong>rmal.com/pdf/Anderson,%20California.pdf<br />

216 http://www.eprl.co.uk


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Table 59 International Facilities that combust straw for heat and electricity generation<br />

Site Feeds<strong>to</strong>ck<br />

Generation<br />

Capacity Comments<br />

Denmark Straw 8.3-28 MW Straw is used in co-firing in large utility power stations in<br />

Denmark, where <strong>the</strong>re is an obligation on <strong>the</strong> powerstations<br />

<strong>to</strong> do so, for example <strong>the</strong> Grenaa site. Due <strong>to</strong><br />

<strong>the</strong> composition of straw <strong>the</strong>re have been severe<br />

problems with slagging, fouling and corrosion. In addition<br />

<strong>the</strong>re are restrictions on <strong>the</strong> temperature of operation.<br />

The Danes have overcome <strong>the</strong>se problems, most<br />

noticeably <strong>by</strong> building stand-alone boilers for <strong>the</strong> straw.<br />

More recently Denmark has built purpose designed straw<br />

power stations at Haslev that consumes 27,000 <strong>to</strong>nnes of<br />

straw per annum, and ano<strong>the</strong>r at Nakskov with an output<br />

of 6MW + 8MW. 217<br />

Przechlewo Straw N/A An old coal power station that provided heating for 18<br />

Poland<br />

houses, a school, a kindergarten and three office and<br />

public utility buildings was replaced with one that used<br />

straw as <strong>the</strong> fuel source. It is owned and run <strong>by</strong> <strong>the</strong> Local<br />

Authority and uses three Apacor Brzeg Dolny boilers, with<br />

a power rating of 2 x 2.5 MW and 1 x 1.25 MW. In<br />

addition <strong>the</strong> site has a straw warehouse, 1800m 2 -<br />

sufficient <strong>to</strong> hold 1 month’s worth of straw. The 2500 <strong>to</strong>ns<br />

of straw used each year must be shredded and<br />

compressed in<strong>to</strong> cubes, with a humidity of 22%. The site<br />

has been in operation since 2001. 218<br />

Såtenergi Straw 20,000 MWh The Air Force site at Såtenergi purchase <strong>the</strong>ir heating<br />

AB,<br />

of district from a straw fired station supplied with straw <strong>by</strong> 40 local<br />

Sweden<br />

heating farmers, who also own 9% of <strong>the</strong> station. Ash generated<br />

is returned <strong>to</strong> <strong>the</strong> fields. 219<br />

China Straw 2 x 12 MW The facility in Sugian began operation in 2006 with<br />

capacity of 200,000 <strong>to</strong>nnes per annum.<br />

8.2.5 Poultry Litter<br />

The UK has several plants that use poultry litter as a feeds<strong>to</strong>ck for energy generation. Poultry Litter is a<br />

mixture of poultry droppings and <strong>the</strong> material used as bedding, often wood chippings. The material has a<br />

calorific value between 8.8 -15GJ/t and a highly variable moisture content of between 20% and 50%,<br />

depending upon husbandry practices. The key players in <strong>the</strong> industry have now resolved most technical<br />

issues associated with using this as a fuel. The ash produced is largely used as a fertiliser, as it is high in<br />

potassium and potash.<br />

The UK has been at <strong>the</strong> forefront of power generation from poultry litter with three plants currently in<br />

operation: Eye and Thetford in England, and Westfield in Scotland. Although it is possible <strong>to</strong> co-fire<br />

poultry litter with coal, <strong>the</strong>re are few examples of this described in <strong>the</strong> literature. Poultry litter now falls<br />

under WID controls, and as such any new facility would have <strong>to</strong> comply with WID emission limits.<br />

217 Case Study: Straw fuelled heating plant in Nakskov, Denmark, European Commission, Direc<strong>to</strong>rate General for Energy and Transport.<br />

218 Case Study: Biomass straw fired boiler plant in Przechlewo, Poland, European Commission, Direc<strong>to</strong>rate General for Energy and Transport.<br />

219 Såtenergi AB- 4 MW Straw heating plant, http://www.managenergy.net/download/nr80.pdf<br />

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Table 60 Burning Poultry Litter <strong>to</strong> Generate Energy<br />

Site and<br />

Opera<strong>to</strong>r<br />

Thetford,<br />

EPRL<br />

Westfield,<br />

EPRL<br />

Location Quantity of<br />

Poultry<br />

Litter (t/yr)<br />

Generation<br />

Capacity<br />

Operational<br />

Norfolk 420,000 38.5 MW 1998 The largest<br />

poultry litter<br />

fuelled plant<br />

in <strong>the</strong> world.<br />

Fife 110,000 10 MW 2000 Uses a<br />

bubbling<br />

fluidised bed<br />

combustion<br />

system.<br />

Eye, EPRL Suffolk 140,000<br />

Plant also<br />

burns horse<br />

bedding and<br />

fea<strong>the</strong>rs<br />

It cost £22<br />

million <strong>to</strong><br />

develop and<br />

implement.<br />

12.7 MW 1992 The world’s<br />

first poultry<br />

litter fuelled<br />

plant.<br />

More than 650,000 <strong>to</strong>nnes of poultry litter are committed <strong>to</strong> <strong>the</strong> three EPRL (Energy Power Resources<br />

Ltd) plants. Significantly EPRL has contracts with <strong>the</strong> all of <strong>the</strong> largest commercial poultry farmers so it is<br />

likely that <strong>the</strong> remaining resource will be more difficult <strong>to</strong> collect and use. Never<strong>the</strong>less it is estimated that<br />

around 80% of <strong>the</strong> poultry litter in <strong>the</strong> UK could be available for energy plants, <strong>to</strong>talling 3.33 million <strong>to</strong>nnes<br />

(using <strong>the</strong> figures generated in Section 4.5), potentially with an energy content of 30 million GJ.<br />

This resource is available “free”. It is a waste with considerable disposal problems and <strong>the</strong> farmers need<br />

<strong>to</strong> get rid of it. However, EPRL pay <strong>the</strong> farmers £10/odt in order <strong>to</strong> ensure a secure supply of good quality<br />

fuel for <strong>the</strong>ir plants.<br />

Applications so far have all been for large scale power generation due <strong>to</strong> <strong>the</strong> difficult nature of <strong>the</strong> fuel<br />

that demands economy of scale <strong>to</strong> be economic. A project at <strong>the</strong> University of Manchester, supported <strong>by</strong><br />

<strong>the</strong> Carbon Trust and Keld Energy, is working <strong>to</strong> develop a small-scale power plant, 200kW,that uses a<br />

fluid bed gasifier capable of converting biomass in<strong>to</strong> combustible gas connected <strong>to</strong> a small gas turbine.<br />

Such a system would provide heat <strong>to</strong> <strong>the</strong> poultry farm, electricity <strong>to</strong> <strong>the</strong> surrounding community, and<br />

provide a bio-secure disposal route for <strong>the</strong> poultry litter. 220<br />

As discussed above agricultural residues have a wide range of composition and properties that often<br />

result in reduced performance and operating difficulties. However <strong>the</strong>y have <strong>the</strong> overwhelming<br />

advantages of being cheap and available. Engineers <strong>the</strong>refore develop robust solutions <strong>to</strong> access <strong>the</strong><br />

profit that can be generated from <strong>the</strong>se feeds<strong>to</strong>cks. We give below some examples of how problems<br />

have been addressed worldwide. In addition a recent patent issued in <strong>the</strong> USA discusses a pyrolysis<br />

method of obtaining energy from poultry litter. 221 We are aware anecdotally of o<strong>the</strong>r gasification concepts<br />

<strong>to</strong> treat poultry litter but no examples of operating plant.<br />

220 The University of Manchester, http://www.manchester.ac.uk/aboutus/news/archive/list/item/?id=3177&year=2007&month=10<br />

221 Thermochemical Method for Conversion of Poultry Litter, US2009031616 (A1), 05.02.2009.


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Table 61 Two international examples of plants that use poultry litter as feeds<strong>to</strong>ck<br />

Capacity<br />

Comments<br />

Location Year<br />

Generation<br />

Moerdijk,<br />

Ne<strong>the</strong>rlands 222<br />

2008 440,000<br />

<strong>to</strong>nnes/annum<br />

36.5 MW Constructed <strong>by</strong> <strong>the</strong> Dutch multiutility<br />

company Delta, <strong>the</strong><br />

feeds<strong>to</strong>ck is sourced through a<br />

cooperative comprised of 629<br />

separate poultry farmers. 223<br />

Benson,<br />

Minnesota,<br />

USA 224<br />

2007 500,000<br />

<strong>to</strong>nnes/annum<br />

55 MW The first poultry-litter fuelled<br />

power plant in <strong>the</strong> USA based<br />

on <strong>the</strong> Fibrowatt plants in <strong>the</strong><br />

UK.<br />

Animal Wastes<br />

The Glanford power station in North Lincolnshire was originally commissioned <strong>to</strong> burn poultry litter, but<br />

was converted <strong>to</strong> allow <strong>the</strong> burning of MBM (Meat and bone meal) in 2000 as part of <strong>the</strong> UK effort <strong>to</strong> deal<br />

with <strong>the</strong> build up of MBM resulting from <strong>the</strong> rules for slaughter and disposal of cattle suffering from BSE.<br />

As of 2004 <strong>the</strong> plant has been licensed <strong>to</strong> burn MBM from any source. It has a generation capacity of<br />

13.5MW.<br />

8.3 EfW Potential<br />

The UK has a number of incineration plants, which currently make little use of <strong>the</strong> heat generated.<br />

Table 62 shows that <strong>the</strong> current permitted incineration capacity in England and Wales in 2007 (this does<br />

not include facilities that burn waste from <strong>the</strong>ir own in-house processes) was about 8.6 million <strong>to</strong>nnes. 225<br />

Facilities for MSW account for about 50% of <strong>the</strong> <strong>to</strong>tal capacity, and only 60% of <strong>the</strong> <strong>to</strong>tal available<br />

capacity was used in 2007.<br />

Table 62 Incineration capacity (<strong>to</strong>nnes) in England and Wales for 2007. 225<br />

Type Permitted<br />

Capacity<br />

Tonnage<br />

Incinerated in<br />

2006<br />

Tonnage<br />

Incinerated in<br />

2007<br />

Animal Carcasses 85,779 22,685 19,427<br />

Animal By-Products 1,258,000 803,480 799,158<br />

Clinical 222,093 114,272 123,349<br />

Co-Incineration of hazardous<br />

waste 1,052,087 215,016 281,099<br />

Co-Incineration of non<br />

hazardous waste 972,660 99,984 347,707<br />

Hazardous 209,175 133,895 132,963<br />

Municipal 4,416,100 3,293,719 3,277,707<br />

Bio-solids 387,500 196,434 190,825<br />

Total 8,603,394 4,879,485 5,172,235<br />

222<br />

Ne<strong>the</strong>rlands plant <strong>to</strong> convert poultry litter <strong>to</strong> energy, http://www.biomassmagazine.com/article.jsp?article_id=2006<br />

223<br />

Ne<strong>the</strong>rlands Plant <strong>to</strong> Convert Poultry Litter <strong>to</strong> Energy, http://www.biomassmagazine.com/article.jsp?article_id=2006,<br />

http://www.delta.nl/web/show/id=84742<br />

224<br />

Fibromin, http://www.fibrowattusa.com/us-projects.cfm?id=16<br />

225<br />

http://www.environment-agency.gov.uk/research/library/data/97795.aspx<br />

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Table 63 shows <strong>the</strong> incinera<strong>to</strong>r throughput <strong>by</strong> region in 2007. London and <strong>the</strong> West Midlands both sent<br />

over 0.9 million <strong>to</strong>nnes <strong>to</strong> MSW facilities, and <strong>the</strong> East of England sent almost 0.6 million <strong>to</strong>nnes <strong>to</strong> animal<br />

<strong>by</strong>-product facilities.<br />

Table 63 Incinera<strong>to</strong>r throughput (‘000 <strong>to</strong>nnes) <strong>by</strong> region in 2007 225<br />

Municipal Animal<br />

<strong>by</strong>-product<br />

O<strong>the</strong>r Total<br />

East Midlands 156 - 183 339<br />

East of England - 583 46 629<br />

London 941 - 105 1,046<br />

North East 206 - 23 229<br />

North West 87 97 193 377<br />

South East 570 34 252 856<br />

South West 2 - 62 64<br />

West Midlands 944 - 102 1,046<br />

Yorkshire and Humber 358 85 105 548<br />

Wales 11 - 25 36<br />

Total 3,278 799 1,095 5,172<br />

Table 66 compares <strong>the</strong> composition of <strong>the</strong> mixed/general waste C&I stream with that for municipal solid<br />

waste. This shows that, whilst <strong>the</strong>re are differences between <strong>the</strong> two <strong>report</strong>ed analyses, in general<br />

mixed/general C&I waste stream has a higher content combustible content than overall MSW arisings.<br />

Table 64 Composition (Wt %) of MSW and mixed/general C&I waste<br />

Typical<br />

MSW<br />

Mixed/general<br />

C&I waste<br />

Report 1 226<br />

Mixed/general<br />

C&I waste<br />

Report 2 227<br />

Paper 14 22 14<br />

Cardboard 7 19 20<br />

Plastic film 3 4 7<br />

Dense plastic 4 6 5<br />

Textiles 2 1 2<br />

O<strong>the</strong>r combustibles 12 7 19<br />

Glass 6 4 4<br />

O<strong>the</strong>r non-combustibles 10 2 6<br />

Food waste 19 25 16<br />

Garden waste 14 3 2<br />

Metal 6 5 3<br />

WEEE 2 1 1<br />

Household hazardous 1 1 1<br />

Recycling initiatives for MSW have targeted and <strong>the</strong>refore removed much of <strong>the</strong> paper, cardboard, glass,<br />

plastic, metal and garden waste categories. The arisings of MSW in <strong>the</strong> UK are estimated (see Section<br />

4.1) <strong>to</strong> be 38 million <strong>to</strong>nnes per annum <strong>by</strong> 2020. If a 50% recycling target is achieved <strong>by</strong> 2020, <strong>the</strong>n 19<br />

million <strong>to</strong>nnes will be recycled, composted or sent <strong>to</strong> anaerobic digestion facilities. It is more difficult <strong>to</strong><br />

estimate <strong>the</strong> amount of MSW that will be landfilled <strong>by</strong> 2020, but if 20% (8 million <strong>to</strong>nnes) was directly<br />

landfilled, <strong>the</strong>n a potential 11 million <strong>to</strong>nnes per annum of MSW could be treated in o<strong>the</strong>r energy recovery<br />

plants (3 million <strong>to</strong>nnes per annum is al<strong>read</strong>y being processed). The need <strong>to</strong> comply with <strong>the</strong> Landfill<br />

226 The composition of municipal solid waste in Wales. Report <strong>by</strong> AEA for <strong>the</strong> Welsh Assembly Government, December 2003.<br />

227 Determination of <strong>the</strong> Biodegradability of Mixed Industrial and Commercial Waste Landfilled in Wales. Report <strong>by</strong> SLR for Environment Agency<br />

Wales, November 2007.


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Directive requirements for <strong>the</strong> diversion of biodegradable waste and for <strong>the</strong> treatment of o<strong>the</strong>r wastes<br />

prior <strong>to</strong> landfill mean that EfW is one of <strong>the</strong> likely options <strong>to</strong> treat this waste.<br />

In addition <strong>the</strong>re are <strong>the</strong> C&I and C&D wastes that will require treatment and disposal.<br />

8.4 Conclusions for Combustion Technologies<br />

Combustion, or incineration is <strong>by</strong> far <strong>the</strong> most common method of extracting energy from solid waste<br />

ei<strong>the</strong>r in most European countries, in ei<strong>the</strong>r untreated form or as a prepared fuel.<br />

It summary<br />

• Combustion is a well established technology and <strong>the</strong> main technical challenges have been<br />

addressed. Whatever <strong>the</strong> difficulties with <strong>the</strong> properties of <strong>the</strong> fuel engineers have developed<br />

robust solutions that have been proven <strong>to</strong> work commercially at most scales. As a result of this,<br />

combustion remains <strong>the</strong> default technology for heat and power against which all new, more<br />

innovative, options must be measured.<br />

• There seems <strong>to</strong> be a combustion solution for all waste fuels. A summary of combustion<br />

alternatives, <strong>the</strong>ir scales of operation and <strong>the</strong> range of feeds<strong>to</strong>cks for which <strong>the</strong>y are suitable is<br />

given in Table 66.<br />

• There remains however significant technical uncertainty surrounding <strong>the</strong> impact of <strong>the</strong><br />

composition of <strong>the</strong> waste on <strong>the</strong> performance of <strong>the</strong> heat exchange surfaces, particularly fouling<br />

and corrosion.<br />

• O<strong>the</strong>r barriers remain, such as <strong>the</strong> largely negative public perception of such sites in some<br />

countries, notably <strong>the</strong> UK.<br />

• A summary of risks and barriers is given in Table 66.<br />

• There are countless examples of combustion practice worldwide on which <strong>to</strong> draw.<br />

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Table 65 Overview of technology, scales of operation and fuel suitability<br />

Burner type Typical size<br />

MW fuel<br />

input<br />

Fuel<br />

quality<br />

Burner Technology<br />

grate (G) or<br />

Fluidised (F)<br />

Domestic 0.015 MW Logs and<br />

pellets<br />

G<br />

Commercial 0.2 MW Wood chip G<br />

upwards most<br />

qualities<br />

Small industrial 2 MW Most dry G<br />

upwards shredded<br />

materials<br />

Large industrial 20 MW Most dry G or F<br />

heat and CHP upwards shredded<br />

materials<br />

not<br />

necessarily<br />

dry<br />

MSW mass burn 20MW Minimally G<br />

incineration upwards sorted<br />

MSW<br />

Large cofiring 100 MW Most dry n/a<br />

upwards shredded<br />

materials.<br />

Preference<br />

for pellets<br />

SRF<br />

Waste Wood<br />

Clean Wood<br />

Domestic Pellet<br />

<br />

Industrial Pellet<br />

<br />

Unsorted Waste<br />

Wet Wastes<br />

Agricultural<br />

Residues<br />

T C Fuels


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Table 66 Risks and barriers <strong>to</strong> combustion<br />

Level of<br />

Risk<br />

Comment<br />

Technical Low <strong>to</strong> Many commercial installations, however <strong>the</strong> materials handling<br />

medium aspects have proved troublesome in <strong>the</strong> UK and <strong>the</strong>re is a lack of<br />

experience.<br />

Agricultural residues and poor quality wood fuels may give high<br />

ash contents that lead <strong>to</strong> problems with boiler fouling.<br />

Wastes regulated under WID will need extensive emissions<br />

moni<strong>to</strong>ring equipment.<br />

Social & Planning High High where used <strong>to</strong> produce electricity on a regional basis as it will<br />

be perceived as an incinera<strong>to</strong>r irrespective of its efficiency or<br />

recycling credentials.<br />

Financial Medium Track record of delays in planning for waste projects are a<br />

disincentive.<br />

Wood and agricultural residues are OK in normal circumstances<br />

but can be delays in urban areas<br />

Regula<strong>to</strong>ry Medium Receives subsidy via <strong>the</strong> Renewables Obligation.<br />

Waste incineration directive compliance is usually necessary.<br />

Co-firing waste in a utility boiler is difficult as it would require <strong>the</strong><br />

reclassification of <strong>the</strong> whole station as an incinera<strong>to</strong>r<br />

Fly ash may contain dioxin and be classed as hazardous waste.<br />

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9 Biological Processes<br />

The recycling initiatives targeting paper, cardboard, glass, plastic, metal and garden waste have also had<br />

<strong>the</strong> effect of increasing <strong>the</strong> food waste content (on a weight percent basis) of <strong>the</strong> remaining waste,<br />

particularly in <strong>the</strong> household waste stream. The food waste stream is now being increasingly targeted for<br />

separated collection and subsequent treatment <strong>by</strong> ei<strong>the</strong>r composting (using in-vessel composting) or<br />

anaerobic digestion. Ultimately this could result in up <strong>to</strong> 4 million <strong>to</strong>nnes per annum of food waste being<br />

sent <strong>to</strong> anaerobic digestion facilities which could generate bio-gas, potentially used for electricity<br />

generation or transport gases, and a solid digestate. We can also add <strong>to</strong> this <strong>the</strong> waste from food<br />

manufacture, distribution and sale and <strong>the</strong> substantial quantities of manures from agriculture. Bio-solids<br />

are a fur<strong>the</strong>r specialised form of wet waste that is used extensively for energy.<br />

9.1 Anaerobic Digestion (AD)<br />

Wet organic<br />

wastes<br />

Anaerobic<br />

digestion<br />

Process Description<br />

Anaerobic digestion is a natural biological process carried out <strong>by</strong> bacteria in low oxygen conditions.<br />

Organic material is converted in<strong>to</strong> biogas (a mixture of methane, carbon dioxide and o<strong>the</strong>r trace gases)<br />

and a solid residue or digestate.<br />

The biological reactions occur in three sequential steps. The organic waste is first broken down in<strong>to</strong><br />

simple sugars and amino acids <strong>by</strong> enzymes (hydrolysed). These <strong>the</strong>n ferment <strong>to</strong> produce fatty acids that<br />

are converted <strong>to</strong> hydrogen, carbon dioxide and acetate <strong>by</strong> ace<strong>to</strong>genic bacteria. Finally methanogenic<br />

bacteria produce biogas, a mixture of carbon dioxide (40%) and methane (60%) and o<strong>the</strong>r trace<br />

compounds. These biological processes operate in aqueous media, and hence are best suited <strong>to</strong> wet<br />

wastes.<br />

Anaerobic bacteria occur naturally and are commonly found in soils and deep water. They produce<br />

biological cultures that thrive within three temperature ranges, 7 - 24°C (psychrophilic), 35-39°C<br />

(mesophilic) and 55-60°C (<strong>the</strong>rmophilic).<br />

Table 67 Comparison of AD systems<br />

Biogas/<br />

Digestate<br />

Heat, power,<br />

grid gas<br />

Psychrophilic Mesophilic Thermophilic<br />

Optimal Temperature and<br />

Range ( o C)<br />

22 (7 - 25) 35 (25 - 42) 60 (49 - 72)<br />

Concentration V dilute Medium High<br />

Retention time (d) >50 20-40 5-20<br />

Gas generation rate Very slow Medium High<br />

Conversion of solid material Low Med <strong>to</strong> High High<br />

Construction Covered dam Steel or Steel or<br />

or lagoon concrete tank concrete tank


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Figure 17 Anaerobic Digester schematic 228<br />

In Europe more than 85% of plants operate within <strong>the</strong> mesophilic temperature range as <strong>the</strong> greatest<br />

number of suitable bacteria species operates at this temperature and are more <strong>to</strong>lerant of varying<br />

environmental conditions. 8% of AD systems in Europe operate in <strong>the</strong> <strong>the</strong>rmophilic range, mostly in<br />

Denmark as <strong>the</strong> <strong>the</strong>rmophillic temperature range is especially applied in centralised AD plants, as are<br />

common in Denmark. The advantage of such systems is <strong>the</strong> reduced time required and <strong>the</strong> greater level<br />

of sterilisation achieved of <strong>the</strong> digestate. The drawback of such systems is <strong>the</strong> greater heat requirement.<br />

Less than 5% of European systems operate in <strong>the</strong> psychrophilic range.<br />

AD systems used <strong>to</strong> treat food and farm wastes have been adapted from well established systems used<br />

<strong>to</strong> treat wastewater solid fractions (bio-solids). The digestion process takes place in sealed tanks<br />

(digesters) that are continuously mixed <strong>to</strong> ensure a uniform reaction rate.<br />

The amount of biogas produced using AD will vary depending on <strong>the</strong> volatile solids component of <strong>the</strong><br />

waste, <strong>the</strong> process design, such as reac<strong>to</strong>r residence times and operating temperature.<br />

228 Schematic taken from “AD biological cycle” page on <strong>the</strong> “Renewable Energy Association”, http://www.r-e-a.net/biofuels/biogas/anaerobic-<br />

digestion/ad-biological-cycle<br />

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Approximately a third of <strong>the</strong> heat production will be used <strong>to</strong> heat <strong>the</strong> digester vessel and maintain <strong>the</strong><br />

bacterial cultures at <strong>the</strong>ir optimum temperature. Fur<strong>the</strong>r heat may be necessary <strong>to</strong> pasteurise <strong>the</strong> solid<br />

residue before it can be sold as fertiliser or soil conditioner.<br />

Recently <strong>the</strong> National Grid Company has announced plans <strong>to</strong> encourage and develop projects that can<br />

inject natural gas quality biogas in<strong>to</strong> <strong>the</strong> National Gas Grid. This will involve <strong>the</strong> removal of carbon<br />

dioxide and any acid gas components <strong>by</strong> a combination of liquid scrubbing and adsorption technologies.<br />

The resulting cleaned gas will <strong>the</strong>n need <strong>to</strong> be compressed <strong>to</strong> ei<strong>the</strong>r transmission pressure of<br />

approximately 30bar or for smaller installations <strong>the</strong> low pressure distribution network at 3.0 and 0.5 bar. 229<br />

This concept has advantages for <strong>the</strong> opera<strong>to</strong>r of an AD plant if <strong>the</strong> incentives are sufficient, in that he will<br />

be able <strong>to</strong> sell <strong>the</strong> biogas in<strong>to</strong> <strong>the</strong> grid all year round. Heat sales from CHP are always problematic with<br />

space heat demand varying throughout <strong>the</strong> year.<br />

Understanding <strong>the</strong> potential for AD requires study on a spatial basis<br />

The technology relies on <strong>the</strong> collection, transport and disposal of large volumes of materials and at each<br />

stage of <strong>the</strong> process <strong>the</strong>re are constraints related <strong>to</strong> <strong>the</strong> location;<br />

• Wastes, crops and manure must be collected from a wide variety of sources and suppliers.<br />

• All feeds<strong>to</strong>cks are high water content, low energy density, and expensive <strong>to</strong> transport.<br />

• The installation must be sited where traffic density and odour will not be a problem and where<br />

<strong>the</strong>re is an electricity network connection and a heat cus<strong>to</strong>mer.<br />

• The unit produces almost as much material as digestate for transport and disposal as it receives<br />

as feeds<strong>to</strong>ck.<br />

• The business will also need access <strong>to</strong> suitable agricultural land within a reasonable transport<br />

radius <strong>to</strong> dispose of <strong>the</strong> digestate.<br />

An accurate estimate of potential would need <strong>to</strong> be carried out <strong>by</strong> mapping waste arisings, energy<br />

demand, gas grid and <strong>the</strong> digestate holding capacity of <strong>the</strong> land as a GIS study. ADAS have carried out<br />

work on <strong>the</strong> holding capacity but this has not as yet been extended <strong>to</strong> digestate.<br />

Feed s<strong>to</strong>cks suitable for anaerobic digestion<br />

Only high moisture content organic feeds<strong>to</strong>ck containing proteins, fats and carbohydrates can be<br />

processed success<strong>full</strong>y <strong>by</strong> anaerobic digestion. Cellulose and lignin digest far <strong>to</strong>o slowly so it is not<br />

suitable for paper and wood. This does mean that a large variety of wastes ranging from farm manures<br />

and bio-solids <strong>to</strong> catering wastes, food wastes, meat, and bone meal can be treated, however <strong>the</strong><br />

processing time (retention time) varies widely with <strong>the</strong> feeds<strong>to</strong>ck composition.<br />

The content of nitrogen compounds in <strong>the</strong> feeds<strong>to</strong>ck needs <strong>to</strong> be managed as <strong>the</strong>y are converted <strong>to</strong><br />

ammonia, which is <strong>to</strong>xic <strong>to</strong> anaerobic bacteria. The C:N ratio is also important as optimal growth of <strong>the</strong><br />

bacteria is achieved when this is 20-30:1.<br />

Food wastes and manures contain high levels of pathogens such as Salmonella and E.coli which must be<br />

destroyed during <strong>the</strong> digestion or during <strong>the</strong> pasteurisation process once digestion is complete.<br />

Scale of operation<br />

Typically digesters based in rural locations and using manures, food waste and energy crops will have an<br />

output of 300kWe, which represents approximately 40k <strong>to</strong>nnes per annum of wet feeds<strong>to</strong>ck, such as <strong>the</strong><br />

BioCycle Plant in South Shropshire and <strong>the</strong> Western Isles Integrated Waste Management Facility.<br />

Larger installations in semi-rural and urban locations that so far have focussed on supermarket and food<br />

processing waste may have an output up <strong>to</strong> 5MWe, for example <strong>the</strong> Wanlip Composting and AD Plant in<br />

Leicester. Sainsbury and PDM indicate that larger installations are unlikely. 230<br />

229 http://www.nationalgrid.com/corporate/Our+Responsibility/News/newsbiogas.htm<br />

230 Announcement <strong>by</strong> Sainsburys and PDM cooperation


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By-products<br />

The digestate can be used as a fertiliser and soil conditioner. Recent practice has been <strong>to</strong> strike an<br />

arrangement between <strong>the</strong> plant opera<strong>to</strong>r and local farms <strong>to</strong> allow <strong>the</strong> sp<strong>read</strong>ing of digestate <strong>to</strong> <strong>the</strong>ir land<br />

in return for treatment of manures.<br />

More recently <strong>the</strong> establishment of <strong>the</strong> Quality Pro<strong>to</strong>col for <strong>the</strong> digestate where it is <strong>to</strong> be sp<strong>read</strong> on<br />

agricultural or forestry land, is intended <strong>to</strong> facilitate <strong>the</strong> use of <strong>the</strong> digestate, although care will still need <strong>to</strong><br />

be taken in Nitrate Vulnerable Zones (NVZ), as discussed in <strong>the</strong> Pro<strong>to</strong>col, as 68% of arable land in<br />

England and 4% in Wales are designated <strong>to</strong> be within NVZs and <strong>the</strong>re are restrictions on how much<br />

nitrogen farmers can apply yearly. 231<br />

A recent example of <strong>the</strong> challenges increased volumes of digestate will create is given <strong>by</strong> Summerleaze’s<br />

Holsworthy site in Devon, which may only sp<strong>read</strong> <strong>the</strong> digestate on land between February and September<br />

during <strong>the</strong> grass growing season, as <strong>the</strong> surrounding farms are lives<strong>to</strong>ck ones. Therefore <strong>to</strong> operate at<br />

maximum capacity it must be able <strong>to</strong> s<strong>to</strong>re six months worth of digestate, <strong>to</strong>talling 42,000m 3 . Its current<br />

s<strong>to</strong>rage capacity is 15,000m 3 . 232<br />

Technology status<br />

Anaerobic digesters are very well established in Germany and o<strong>the</strong>r EU Member states, which have or<br />

have had favourable policy instruments.<br />

The table below provides <strong>the</strong> number of AD plants in EU countries and <strong>the</strong>ir electricity generation<br />

capacities in 2005. It is clear from <strong>the</strong> table that <strong>the</strong>re are a number of European countries in which <strong>the</strong><br />

uptake of AD, ei<strong>the</strong>r on-farm or centralised (CAD), <strong>by</strong> <strong>the</strong> agricultural industry has been much greater<br />

than in <strong>the</strong> UK, although it is also clear that Germany is quite exceptional.<br />

Table 68: Numbers of biogas plants in EU-countries producing electricity 233<br />

Country Agricultural AD<br />

plants<br />

Installed capacity MWe<br />

Austria 159<br />

29<br />

+150 <strong>to</strong> end 2007 + 40 <strong>to</strong> end 2007<br />

Belgium 6 12.3<br />

Denmark 58 on-farm<br />

20 CAD<br />

40<br />

France 3 n/a<br />

Germany > 3000 550<br />

Great Britain


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Some water companies are beginning <strong>to</strong> suggest <strong>the</strong> co-digestion of waste water and food waste<br />

alongside <strong>the</strong> digestion of bio-solids, such as <strong>the</strong> proposed site at Cumbernauld in Glasgow <strong>by</strong> Scottish<br />

Water. This arrangement could yield a higher biogas output as well as enabling a higher proportion of<br />

ROCs <strong>to</strong> be earned.<br />

Table 69 Risks Associated with Anaerobic Digestion<br />

Level of Risk Comment<br />

Technical Low <strong>to</strong> medium Established mature technology with operating commercial<br />

plant in existence.<br />

Limited experience in UK. Recent incentives may stretch<br />

UK suppliers.<br />

Poor reputation from early Holsworthy experience.<br />

Sensitive <strong>to</strong> feeds<strong>to</strong>ck composition, can be poisoned <strong>by</strong><br />

Social &<br />

Planning<br />

trace elements.<br />

Medium Not as divisive as an incinera<strong>to</strong>r but transport of slurries in<br />

rural areas is a major issue and focus for opposition, as<br />

may be large scale transport of food wastes.<br />

Financial Low Installations are being financed in <strong>the</strong> UK at present and<br />

fur<strong>the</strong>r experience should make this easier.<br />

Regula<strong>to</strong>ry Medium Receives subsidy via <strong>the</strong> Renewables Obligation at an<br />

enhanced rate of 2 ROCs under <strong>the</strong> banding<br />

arrangements.<br />

Policy may change under installations lifetime although<br />

current practice is <strong>to</strong> maintain <strong>the</strong> financial position of<br />

existing plant.<br />

The installation is classed as a waste management<br />

operation and subject <strong>to</strong> regulation as such which brings<br />

additional costs and responsibility.<br />

Digestate disposal is an important consideration and a<br />

change of rules could materially affect <strong>the</strong> operating costs<br />

of <strong>the</strong> installation or even prevent operation.<br />

9.1.1 Anaerobic Digestion of food waste from MSW<br />

The AD capacity for solid waste in <strong>the</strong> UK is growing. From a capacity of 135,000 <strong>to</strong>nnes in 2004, it<br />

increased <strong>to</strong> 277,000 <strong>to</strong>nnes through <strong>the</strong> addition of 6 new plants in 2005 and 2006. 234 This utilisation<br />

level is still very small compared <strong>to</strong> <strong>the</strong> waste potentially available <strong>to</strong> it. BERR estimates that <strong>the</strong> UK<br />

generates over 100 million <strong>to</strong>nnes of wastes that would be suitable for AD (90 million <strong>to</strong>nnes of<br />

agricultural wastes and 9 million <strong>to</strong>nnes of food waste).<br />

It is likely that utilisation levels will continue <strong>to</strong> grow, assisted <strong>by</strong> <strong>the</strong> reclassification of anaerobic digestate<br />

<strong>to</strong> no longer a waste product, so long as it is used as fertiliser on farmland.<br />

Defra intend for AD technology <strong>to</strong> be used throughout <strong>the</strong> UK <strong>by</strong> 2020, that it will be “making a significant<br />

and measurable contribution <strong>to</strong> our climate change and wider environmental objectives“ in part through<br />

<strong>the</strong> production of around 10-20TWh of energy. 235 For comparison, Drax power station in North Yorkshire,<br />

produces 25TWh annually, approximately 7% of <strong>the</strong> UK’s electricity mix. 236<br />

234 Anaerobic Digestion and its role in Transport Fuels, Renewable Energy Association, 2007.<br />

235 Anaerobic Digestion – Shared Goals, Defra, 2009, http://www.defra.gov.uk/environment/waste/ad/pdf/ad-sharedgoals-090217.pdf<br />

236 http://www.draxpower.com


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Almost all UK solid waste AD sites only utilise <strong>the</strong> biogas collected for <strong>the</strong> generation of electricity, and<br />

some heat required for <strong>the</strong> process. Little of <strong>the</strong> remaining heat is utilised, in external heating systems for<br />

example. In addition <strong>the</strong> biogas has <strong>the</strong> potential <strong>to</strong> be used in o<strong>the</strong>r ways, for example as a transport<br />

fuel. Current policy favours <strong>the</strong> production of electricity. 249 However, <strong>the</strong> Renewable Energy Strategy<br />

and increased targets for renewable heat in <strong>the</strong> UK may make it more feasible <strong>to</strong> inject gas in<strong>to</strong> <strong>the</strong> grid in<br />

<strong>the</strong> future.<br />

237, 238<br />

Current operational AD plants in <strong>the</strong> UK for solid waste are:<br />

• The BioCycle Plant in South Shropshire, run <strong>by</strong> Greenfinch, has been in operation since 2006<br />

and was built as a Defra Waste Technology Demonstra<strong>to</strong>r Project. The system now takes 4,100<br />

<strong>to</strong>nnes of kitchen only waste (originally it <strong>to</strong>ok kitchen and garden waste but <strong>the</strong> feeds<strong>to</strong>ck was<br />

<strong>to</strong>o contaminated) from households and commercial premises, converting it in<strong>to</strong> biogas and<br />

ultimately electricity with a 0.2kW output annually. 239<br />

• The Wanlip Composting and AD Plant in Leicester started operation in 2004 at <strong>the</strong> Severn Trent<br />

Sewage Works, using <strong>the</strong> organic component of MRF from MSW. 240 The waste goes through five<br />

processes: homogenisation, sand separation, hydrolysis, digestion, and decantation. The 5mm<br />

and smaller component is mixed <strong>to</strong> a slurry and pumped with air for 24 hours as an aerobic<br />

hydrolysis process <strong>the</strong>n <strong>the</strong> material undergoes an 18 day <strong>the</strong>rmophilic wet AD process, before<br />

being composted <strong>to</strong> produce CLO (compost like output) for fur<strong>the</strong>r use. The site accepts up <strong>to</strong><br />

50,000 <strong>to</strong>nnes per annum and has a 1.5MW potential output. 166<br />

• Summerleaze Ltd, at Holsworthy, Devon was <strong>the</strong> UK’s first centralised AD site, and opened in<br />

2005 for <strong>the</strong> digestion of agricultural slurries. It now handles organic wastes from bakeries and<br />

food processors, abat<strong>to</strong>irs, fish processors, cheese producers, biodiesel manufacturers and local<br />

councils in a system capable of processing 80,000 <strong>to</strong>nnes per annum currently. 241 The methane<br />

produced is used <strong>to</strong> generate 2.7MW, with approximately 10% of this used <strong>to</strong> run <strong>the</strong> plant and<br />

<strong>the</strong> remaining 90% exported <strong>to</strong> <strong>the</strong> National Grid. 242 One advantage of accepting food waste, is<br />

that it attracts higher gate fees than agricultural waste, encouraging <strong>the</strong> feasibility of <strong>the</strong> site.<br />

• As part of <strong>the</strong> Western Isles Integrated Waste Management Facility in Scotland a waste treatment<br />

centre incorporating recycling and MBT, <strong>the</strong> EarthTech AD plant, takes up <strong>to</strong> 12,000 <strong>to</strong>nes of<br />

biodegradable municipal waste and generates 0.24MW of electricity annually. This plant also has<br />

a CHP system incorporated in<strong>to</strong> it, which is used <strong>to</strong> heat <strong>the</strong> AD system itself.<br />

• At <strong>the</strong> Premier Waste AD site in Thornley, Durham, capable of processing 20,000 <strong>to</strong>nnes/yr of<br />

MSW, three concrete <strong>to</strong>wers are used as <strong>the</strong> AD vessels. This project is part of Defra’s<br />

Demonstra<strong>to</strong>r Project, and after some initial problems <strong>the</strong> project recommenced demonstra<strong>to</strong>r<br />

phase in mid 2008. 243<br />

Identifying a comprehensive list of currently functioning AD sites, and sites that will become operational in<br />

<strong>the</strong> future is difficult due <strong>to</strong> <strong>the</strong> level of interest in this area. Many potential sites are <strong>report</strong>ed as<br />

certainties, when in fact <strong>the</strong>y do not get as far as <strong>the</strong> planning stage, or markets change and a company<br />

decide not <strong>to</strong> go ahead with a site development. Also, many early AD sites have ceased operation for<br />

technical or financial reasons.<br />

A planned AD site is at Cumbernauld in Glasgow, for <strong>the</strong> treatment of 30,000 <strong>to</strong>nnes per annum of local<br />

food waste, <strong>by</strong> Scottish Water. The site is expected <strong>to</strong> be operating in 2010, <strong>to</strong> generate 1MW of<br />

237<br />

EU Requirement Approved Plants Report – Section VI Biogas Plants, 18 Feb 2009, http://www.defra.gov.uk/animalh/<strong>by</strong>prods/approvals/section6.pdf<br />

238<br />

ENDS Report 404, September 2008, p. 30-33, Biogas scents <strong>the</strong> sweet smell of success,<br />

239<br />

South Shropshire Biodigester, Ludlow Biocycle South Shropshire/Greenfinch Ltd, Information Sheet, 2008.<br />

240<br />

Anaerobic Digester at Wanlip, BiffaLeicester, http://biffaleicester.co.uk/about/composting.php?&printpage=true<br />

241<br />

Holsworthy Biogas Plant, Case Study 2, http://www.devon.gov.uk/renewable_energy_guide_case_study_2.pdf and “UK’s largest" AD plant<br />

permitted <strong>to</strong> take more food waste, 2008, http://www.letsrecycle.com/do/ecco.py/view_item?listid=37&listcatid=333&listitemid=10429<br />

242<br />

Andigestion, Holsworthy, http://www.andigestion.co.uk/content/holsworthy<br />

243<br />

Defra Factsheet, Premier, http://www.defra.gov.uk/environment/waste/wip/newtech/dem-programme/pdf/Premier.pdf<br />

131


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electricity and 1MW of heat. Meanwhile a 75,000 <strong>to</strong>nnes per annum site has planning permission in<br />

Bedding<strong>to</strong>n for processing kitchen waste and <strong>the</strong> organic component of <strong>the</strong> systems al<strong>read</strong>y on <strong>the</strong> site,<br />

generating 2MW of electricity a year.<br />

A demonstra<strong>to</strong>r site run <strong>by</strong> Organic Power in Somerset has been working <strong>to</strong> convert food, animal and<br />

o<strong>the</strong>r organic wastes <strong>to</strong> biomethane through AD for use as a transport fuel for a number of years. The<br />

biomethane is converted <strong>to</strong> CNG (compressed natural gas) with <strong>the</strong> addition of a small amount of<br />

biohydrogen <strong>to</strong> ensure optimum combustion in CNG vehicles. 244<br />

International Situation<br />

One exemplar example of <strong>the</strong> use of large scale use of AD for MSW is <strong>the</strong> Brecht II facility in Belgium,<br />

which began operation in 2000 with a capacity of 50,000 <strong>to</strong>nnes per annum. The feeds<strong>to</strong>ck for <strong>the</strong> plant<br />

is mainly organics such as garden, kitchen and food waste <strong>to</strong> which nappies, non-recyclable paper or<br />

cardboard can be added. The facility processes <strong>the</strong> waste from <strong>the</strong> municipalities around <strong>the</strong> city of<br />

Antwerp. During 2005, 7.4 million m 3 of biogas was produced, used <strong>to</strong> generate 9.1 GWh of electricity.<br />

The plant also produces 20,000 <strong>to</strong>nnes of compost which meets <strong>the</strong> Flemish regulations for high quality<br />

soil amendment.<br />

9.1.2 Anaerobic Digestion of Commercial Waste<br />

Many food producers, including <strong>the</strong> major supermarket chains, have stated <strong>the</strong>ir wish <strong>to</strong> use waste<br />

diversion methods for <strong>the</strong>ir food wastes. Although <strong>the</strong>re are only two strictly commercial food waste sites<br />

operational at <strong>the</strong> moment (and one of <strong>the</strong>se is a demonstra<strong>to</strong>r project), it is likely that this number will<br />

increase in <strong>the</strong> very near future, due <strong>to</strong> <strong>the</strong> significant rise in interest in this process.<br />

The demonstration scale anaerobic digestion facility exists at Waterbeach, Cambridge Research Park,<br />

near Cambridge. Trials of commercial waste materials such as agricultural, biodegradable industrial,<br />

kitchen and animal <strong>by</strong>-product wastes are being conducted at <strong>the</strong> site which can handle up <strong>to</strong> 17 <strong>to</strong>nnes<br />

of material per day. 245<br />

The Twinwoods Biogen Greenfinch site in Mil<strong>to</strong>n Earnest north of Bedford accepts up <strong>to</strong> 42,000 <strong>to</strong>nnes of<br />

commercial food waste combined with 12,000 <strong>to</strong>nnes of pig slurry each year and converts it <strong>to</strong> 1MW of<br />

electricity, 1.65MW of heat energy which is largely consumed <strong>by</strong> <strong>the</strong> process itself, and 32,000 <strong>to</strong>nnes of<br />

bio-fertiliser.<br />

A fur<strong>the</strong>r commercial food waste site is at Westwood, Bedford, Northamp<strong>to</strong>nshire, <strong>to</strong> be operated <strong>by</strong><br />

Biogen Greenfinch. It is due <strong>to</strong> be operational in 2009 and will be able <strong>to</strong> process 45,000 <strong>to</strong>nnes of food<br />

waste each year, generating 1.5MW of electricity and 35,000 of biofertiliser. The supermarket company<br />

Sainsbury’s recently announced that <strong>the</strong>y were investing in his facility, with <strong>the</strong> intention that<br />

supermarkets close <strong>to</strong> <strong>the</strong> site and its near<strong>by</strong> distribution centre will use <strong>the</strong> process. 207<br />

Ano<strong>the</strong>r potential AD site in Doncaster has been granted permission, this site will process 45,000 <strong>to</strong>nnes<br />

of food waste each year for Prosper De Mulder (PDM), a commercial food waste firm and Sainsbury’s has<br />

al<strong>read</strong>y expressed a strong interest. It is expected <strong>to</strong> generate 2MW of electricity.<br />

Drinks firm Diageo has announced its plans <strong>to</strong> construct an AD facility at its Cameronbridge distillery in<br />

Fife. 238<br />

244 Organic Power Website, http://www.organic-power.co.uk/press_articles.aspx<br />

245 Waterbeach AD Site, http://www.andigestion.co.uk/content/waterbeach


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International Situation<br />

Identifying sites that use AD <strong>to</strong> dispose of commercial organic wastes is difficult as many are simply<br />

recorded as accepting ‘biowaste’ without fur<strong>the</strong>r details. Austria cites several AD sites that accept only<br />

catering waste, including <strong>the</strong> Bruck a.d. Leitha site (20,000 <strong>to</strong>nnes p.a.), <strong>the</strong> Hagenbrunn site (20,000<br />

<strong>to</strong>nnes/yr) and <strong>the</strong> Heiligenkreuz am Vase site (12,000 <strong>to</strong>nnes p.a.). 246<br />

Bellisimo, an American frozen meal producer is constructing its second 5.25 US million gallon digester at<br />

its production facility in rural Ohio, one of <strong>the</strong> first American companies <strong>to</strong> invest in this technology. 247<br />

The system’s output will be used within <strong>the</strong> fac<strong>to</strong>ry.<br />

9.1.3 Anaerobic Digestion of Biosolids<br />

The digestion of biosolids is a special case of anaerobic digestion. Sewage gas is <strong>the</strong> result of controlled<br />

anaerobic digestion (AD) occurring within a sewage handling facility, with 66% of sewage generated<br />

al<strong>read</strong>y treated <strong>by</strong> AD in <strong>the</strong> UK in 220 sludge digesters. 248,249 The process occurs in a well mixed,<br />

heated reac<strong>to</strong>r but <strong>the</strong> reactions take some time due <strong>to</strong> <strong>the</strong> relatively low concentration of volatile solids.<br />

Sewage gas feed s<strong>to</strong>ck is <strong>the</strong> lef<strong>to</strong>ver sludge from <strong>the</strong> activated sludge process used at sewage<br />

treatment plants. Much of <strong>the</strong> biogas generated from this process is used <strong>to</strong> supply <strong>the</strong> needs of <strong>the</strong><br />

processing plant. Water UK estimate that 60% of <strong>the</strong> biogas produced is collected and used <strong>to</strong> generate<br />

renewable heat and power <strong>by</strong> CHP engines, <strong>to</strong>talling 88MW of electricity. 249 However this represents<br />

only 14% of <strong>the</strong> energy requirements of <strong>the</strong> industry, as <strong>the</strong> water processing industry is <strong>the</strong> UK’s fourth<br />

most energy-intensive industry, accounting for approximately 3% of <strong>the</strong> UK’s electricity consumption. 250<br />

Defra has set <strong>the</strong> aim for <strong>the</strong> water companies <strong>to</strong> supply 20% of <strong>the</strong>ir energy needs from renewable<br />

sources, such as <strong>the</strong>ir in house AD processes, <strong>by</strong> 2020. 251 As of April 2009 water companies earn <strong>the</strong><br />

reduced 0.5 ROCs per MWh of energy <strong>the</strong>y generate from biogas. 249 Some water companies are<br />

considering <strong>the</strong> use of food and o<strong>the</strong>r wastes as additional feeds<strong>to</strong>cks in response <strong>to</strong> <strong>the</strong> enhanced level<br />

of incentives given <strong>to</strong> anaerobic digestion in <strong>the</strong> reformed renewable obligation. 248<br />

Many water companies have pledged <strong>to</strong> reduce <strong>the</strong>ir carbon footprints and one way of doing this would<br />

be through achieving a greater efficiency of harvesting <strong>the</strong> biogas. For example Anglian Water has<br />

committed <strong>to</strong> increase <strong>the</strong> proportion of its energy met from biogas and wind power from 2% <strong>to</strong> 20% <strong>by</strong><br />

2010; Sou<strong>the</strong>rn Water aims <strong>to</strong> increase renewable generation <strong>to</strong> 20% <strong>by</strong> 2020, up from 10% in 2008;<br />

Thames Water aims <strong>to</strong> increase its renewable generation from its current level of 14% <strong>to</strong> 18% <strong>by</strong> 2020;<br />

and United Utilities intends <strong>to</strong> increase it in house electricity generation <strong>by</strong> 8% <strong>by</strong> 2012. 249<br />

9.1.4 Anaerobic Digestion of Agricultural wastes<br />

Anaerobic digestion of animal wastes is an established method of dealing with significant quantities of<br />

animal slurries and residues. Controlled anaerobic digestion of such residues, with collection and<br />

utilisation of <strong>the</strong> bio-methane produced is less well established in <strong>the</strong> UK.<br />

The bio methane potential (Bo) of manure and slurry is <strong>the</strong> methane producing potential of <strong>the</strong> manure,<br />

expressed as cubic meters (m 3 ) of methane per kilogram of Volatile Solids (VS), also referred <strong>to</strong> as <strong>the</strong><br />

maximum methane producing capacity for <strong>the</strong> manure. It varies <strong>by</strong> animal species and diet. Table 70<br />

246<br />

IEA Biogas, Plant List, http://www.iea-biogas.net/anlagelisten/Plantlist_08.pdf<br />

247<br />

Bellisimo Foods, http://www.bellisiofoods.com/sustainability.html, Turn Food Waste in<strong>to</strong> Energy, Environmental Defence Fund,<br />

http://innovation.edf.org/page.cfm?tagid=1339 .<br />

248<br />

Water UK, Water Industry at <strong>the</strong> hub of anaerobic digestion, 17/02/09, http://www.water.org.uk/home/news/press-releases/ad-vision<br />

249<br />

ENDS Report 404, September 2008, p.30-33, Biogas Scents <strong>the</strong> Sweet Smell of Success.<br />

250<br />

ENDS Report 401, June 2008, p.32-36, Water Companies call in <strong>the</strong> Carbon Accountants.<br />

251<br />

Defra (2009) Anaerobic Digestion – shared goals available www.defra.gov.uk<br />

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describes <strong>the</strong> characteristics previous discussed in <strong>the</strong> agricultural residues section, but also details <strong>the</strong><br />

bio-methane potential of <strong>the</strong> material.<br />

Table 70 Animal manure generation characteristics<br />

Bio Methane: cubic meters (m 3 ) of methane per kilogram of Volatile Solids (VS).<br />

Animal Proportion of<br />

<strong>the</strong> year<br />

housed<br />

Proportion of<br />

waste<br />

collected as<br />

slurry<br />

Volatile<br />

Solids<br />

kg/head/day<br />

Bio methane<br />

potential<br />

m 3 CH4/kg VS<br />

Dairy cow 59% 66% 3.48 0.24<br />

O<strong>the</strong>r cattle<br />

(excl. calves)<br />

50% 18% 2.7 0.17<br />

Calves 45% 0% 1.46 0.17<br />

Dry sow 100% 35% 0.63 0.45<br />

Sows plus<br />

litters<br />

100% 75% 0.63 0.45<br />

Fattening pig<br />

(20 – 130kg)<br />

90% 33% 0.49 0.45<br />

Weaners<br />

(


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• The AD site at Bank Farm in Wales was one of <strong>the</strong> first on farm AD sites in <strong>the</strong> UK, becoming<br />

operational in 1991 with a capacity <strong>to</strong> treat 790m 3 . It has recently been converted <strong>to</strong> generate<br />

electricity from <strong>the</strong> methane produced on site.<br />

A proposed AD site at Piddlehin<strong>to</strong>n in Dorset has recently been granted panning permission. It is<br />

expected that this site will accept 35,000 <strong>to</strong>nnes per annum of food waste, green waste and pig slurry,<br />

and generate electricity and a biofertiliser. 255<br />

Fur<strong>the</strong>r sites that are <strong>full</strong>y consented but are not yet operational are Eye Airfield in Suffolk which is<br />

expected <strong>to</strong> have an output of 1.05 MW, Dimmer in Somerset anticipated <strong>to</strong> have a 3MW output, and<br />

Lowe Farm with a predicted output of 0.5MW.<br />

International Situation<br />

Digestion of agricultural manure and slurries <strong>by</strong> controlled AD are well utilised in some European<br />

Countries. Centralised Anaerobic Digestion was first used in Denmark in <strong>the</strong> late 1980s. Its appeal is<br />

growing rapidly and its use is now common in Germany and <strong>to</strong> some extent in Sweden and Italy.<br />

Production of biogas in <strong>the</strong> EU 27 has risen steadily over <strong>the</strong> last few years and <strong>to</strong>talled 62 TWh in 2006<br />

(once again, compare this against Drax power station output of 25TWh p.a.). 256<br />

It is worth noting that <strong>the</strong> use of AD systems across Europe can be split in<strong>to</strong> two distinct types. Sou<strong>the</strong>rn<br />

countries such as Italy, Portugal and Spain use it as a waste-water treatment technology because <strong>the</strong><br />

waste is collected at high water content levels, so containing low solid residues. While in nor<strong>the</strong>rn<br />

European countries such as Germany, Denmark and Switzerland <strong>the</strong> water content is considerably lower,<br />

<strong>the</strong> solid content correspondingly higher and <strong>the</strong> systems optimized for fertilizer production. 257<br />

Denmark<br />

There are over 20 centralised plants operating in Denmark, with a fur<strong>the</strong>r 20 farm scale operations.<br />

Feeds<strong>to</strong>cks are mainly pig and cattle manure, but also include waste food, fat sludge and brewery<br />

wastes. 257<br />

• The Vester Hjermitslev was <strong>the</strong> first centralized co-digestion plant in Denmark, built in 1984 and<br />

supplied <strong>by</strong> 5 cattle and pig farms which supply slurry <strong>to</strong> <strong>the</strong> plant, <strong>to</strong>ge<strong>the</strong>r with a small amount<br />

of fish processing waste, tannery waste and waste fodder. The process operates at 37°C, with a<br />

sanitation stage of 4½ hours at 57°C. Once this is completed <strong>the</strong> biogas can be utilised in <strong>the</strong><br />

onsite CHP unit in <strong>the</strong> 2 mo<strong>to</strong>rs (840 kW +770 kW). Any overproduction is used in a gas boiler<br />

(250 kW). 257<br />

• The Ribe Biogas Plant began operating in 1990 and is supplied <strong>by</strong> 69 lives<strong>to</strong>ck farms (cattle, pig,<br />

poultry, mink), <strong>to</strong>ge<strong>the</strong>r with waste from abat<strong>to</strong>irs, food and fish waste. The facility is owned <strong>by</strong><br />

<strong>the</strong> supplying farmers, a food processing company that supplies organic waste <strong>to</strong> <strong>the</strong> plant, <strong>the</strong><br />

regional power company and two investment companies. The site operates at a digestion<br />

temperature of 53°C, and <strong>the</strong> minimum retention time of 4 hours ensures <strong>the</strong> digestate is<br />

sanitised, and is <strong>the</strong>n used <strong>by</strong> <strong>the</strong> slurry providers as a liquid fertiliser, or sold as surplus. The<br />

biogas produced <strong>by</strong> <strong>the</strong> system is piped <strong>to</strong> a CHP pant at Ribe, which generates electricity and<br />

heat for <strong>the</strong> city using a mix of bio gas and natural gas. 257<br />

• Nysted biogas plant was built as an extension <strong>to</strong> <strong>the</strong> al<strong>read</strong>y established Hashøj biogas plant.<br />

Slurry and manure is received from 36 farms and is mixed with waste from <strong>the</strong> sugar industry, <strong>the</strong><br />

medicinal industry, tanneries, an abat<strong>to</strong>ir as well as fruit and vegetable waste and held at 38°C,<br />

with a sanitation phase consisting of 8 hours at 55°C. The plant is also able <strong>to</strong> process source<br />

separated household waste. The biogas produced is used in a 2300 kW engine <strong>to</strong> generate<br />

electricity for <strong>the</strong> grid and heat for 150 cus<strong>to</strong>mers. 257<br />

255 Green Light for £5.5 Million Dorset AD Facility, 16.03.09, LetsRecycle.com,<br />

http://www.letsrecycle.com/do/ecco.py/view_item?listid=37&listcatid=217&listitemid=31237<br />

256 Danish Centralised Biogas Plants – Plant Descriptions, Bioenergy Department, University of Sou<strong>the</strong>rn Denmark, 2000.<br />

257 Environmental Aspects of Biogas Technology, B. Klingler, German Biogas Association, AD-NETT.<br />

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Germany<br />

Germany has <strong>by</strong> far <strong>the</strong> greatest number of AD sites in Europe. The 2.4M<strong>to</strong>e p.a. of biogas produced<br />

from over 3,700 plants is largely used in co-generation facilities, and generated 1,270 MW of electricity in<br />

2007. 258 Estimates are that Germany will exceed 3,000 MW <strong>by</strong> 2020, 259 despite <strong>the</strong> annual increment<br />

slowing from 800 units per annum in 2006 <strong>to</strong> 250 per annum in 2007. This slowing is felt <strong>to</strong> be due <strong>to</strong><br />

higher energy crop prices and a doubling in <strong>the</strong> equipment costs.<br />

The incentives system of producing renewable electricity in Germany has largely favoured <strong>the</strong> uptake of<br />

on-farm AD systems <strong>by</strong> farmers seeking <strong>to</strong> enhance <strong>the</strong>ir income but <strong>the</strong> scale of operation is increasing<br />

and <strong>the</strong>re are <strong>report</strong>s of very large plants now being built specifically for injection of gas in<strong>to</strong> <strong>the</strong> grid.<br />

For small-scale AD <strong>the</strong> additional tariff is nearly twice that of renewable obligation certificates in <strong>the</strong> UK,<br />

with extra available for CHP and for cultivated biomass feeds<strong>to</strong>ck. Driven <strong>by</strong> this market, technological<br />

advances made in Germany enable dry fermentation and co-digestion with energy crops, increasing <strong>the</strong><br />

potential for biogas production. The industry is also backed up <strong>by</strong> a large number of suppliers and good<br />

technical support.<br />

Figure 18 German AD sites and <strong>the</strong> electrical output 260<br />

In Germany over 200 companies are offering services in connection with biogas technology, e.g.<br />

consulting, planning, manufacturing and delivery of parts and components (pumps, stirrers, engines,<br />

tanks) as well as servicing. It is estimated that <strong>to</strong>ge<strong>the</strong>r with <strong>the</strong> operating staff 8,000 jobs are depending<br />

on <strong>the</strong> services revolving around biogas technology so far.<br />

We give below a small selection of interesting examples from Germany illustrating <strong>the</strong> communal<br />

character of many installations and <strong>the</strong> large scale which is now possible.<br />

• The biogas plant in Reichenbach, in Saxony became operational in 2007, producing 845kW from<br />

liquid manure from <strong>the</strong> local farming cooperative. The waste heat produced is sold <strong>to</strong> <strong>the</strong> local<br />

hospital.<br />

• Jühnde (population 750, 220 households), near Göttingen became <strong>the</strong> first bioenergy village in<br />

Germany. 261 Ten agricultural businesses supply <strong>the</strong> 700kW electrical and 740kW heat Hasse<br />

biogas plant with slurry, grass, maize silage and garden waste, which <strong>to</strong>ge<strong>the</strong>r with <strong>the</strong> connected<br />

258 Renewables made in Germany, http://www.renewables-made-in-germany.com/en<br />

259 http://www.renewables-made-in-germany.com/en/biogas/<br />

260 Source German Biogas Association<br />

261 The First Bioenergy Village in Germany, http://www.german-renewable-energy.com/Renewables/Navigation/Englisch/Biomasse/case-<br />

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heat and power genera<strong>to</strong>r (powered with local biomass) generate enough electricity and heat <strong>to</strong><br />

supply <strong>the</strong> requirements of <strong>the</strong> village.<br />

• Germany’s first industrial sized biogas plant opened in 2008, on <strong>the</strong> Klarsee industrial estate in<br />

Penkun, Mecklenburg-Western Pomerania on <strong>the</strong> German-Polish border. 262 The site takes silage<br />

and manure (<strong>to</strong>ge<strong>the</strong>r with maize and o<strong>the</strong>r cereals) from local farms and creates slurry <strong>to</strong> be<br />

processed <strong>by</strong> 40 independent digesters. The methane produced is converted in<strong>to</strong> electricity, with<br />

<strong>the</strong> plant capable of producing a 20MW output.<br />

Sweden<br />

Sweden is well known for having created several examples of a biogas network used <strong>to</strong> power vehicles.<br />

In Linköping a biogas plant was built in 1997, treating 100,000 <strong>to</strong>nnes p.a. or animal slaughter-house<br />

waste and industrial organic waste and producing 7.7 million m 3 per annum of upgraded biogas. This<br />

biogas is <strong>the</strong>n used <strong>to</strong> power <strong>the</strong> city buses plus several light and heavy vehicles, as well as a number of<br />

private vehicles. 263 Sweden is well placed <strong>to</strong> develop such systems as <strong>the</strong> country had a considerable<br />

number of gas powered vehicles <strong>to</strong> begin with (13,500 in 2008, 110 gas filling stations 264 ) , and <strong>the</strong> gas<br />

distribution network is not that extensive, for example it does not reach Linköping. Ano<strong>the</strong>r <strong>to</strong>wn in<br />

Sweden, Laholm, has been injecting <strong>the</strong> biogas its AD digester produces in<strong>to</strong> <strong>the</strong> local natural gas grid<br />

since 2001. The digester accepts 48,000 <strong>to</strong>nnes p.a. of agricultural manures and industrial organic<br />

waste. 265<br />

A similar project in <strong>the</strong> UK, undertaken jointly <strong>by</strong> Sita UK, Gasrec and Boc, announced in June 2008 that<br />

<strong>the</strong>y had produced a biomethane transport fuel from landfill gas at <strong>the</strong> Sita UK landfill site in Albury,<br />

Surrey. 266 This landfill site produces 2,300m 3 of landfill gas per hour, and <strong>the</strong> intention is <strong>to</strong> use this <strong>to</strong><br />

produce 5,000 <strong>to</strong>nnes of biomethane for use <strong>by</strong> <strong>the</strong> site opera<strong>to</strong>r, <strong>by</strong> haulage firm Hardstaff Group, <strong>by</strong> a<br />

Sainsbury’s delivery truck and <strong>by</strong> a street cleaning vehicle in Camden <strong>to</strong> give feedback on a range of<br />

uses. The process upgrades <strong>the</strong> landfill gas <strong>by</strong> dewatering, <strong>the</strong>n removal of hydrogen sulphide, carbon<br />

dioxide and nitrogen, selectively capturing 85% of <strong>the</strong> methane processed, at 95% purity. The gas<br />

produced is <strong>the</strong>n liquefied for use. Potentially this fuel could also be used in CHP plants.<br />

9.2 Composting - an alternative <strong>to</strong> Anaerobic Digestion<br />

Process Description<br />

Composting is <strong>the</strong> aerobic decomposition <strong>by</strong> micro-organisms of biodegradable material <strong>to</strong> produce a<br />

residue - compost. It is a process primarily used for <strong>read</strong>ily degradable organic materials, such as source<br />

separated green garden wastes and kitchen wastes.<br />

The waste is degraded <strong>by</strong> "heat-loving" micro-organisms. This is a biological process that oxidises <strong>the</strong><br />

organic matter <strong>to</strong> break it down <strong>to</strong> a more simple form. A high temperature within <strong>the</strong> process is important<br />

<strong>to</strong> eliminate pathogens that may be present in <strong>the</strong> source materials.<br />

The composting operations must ensure that <strong>the</strong> micro-organisms are kept supplied with moisture,<br />

oxygen, food and nutrients and that conditions such as temperature remain in <strong>the</strong> optimum range. A<br />

large number of procedures and engineered solutions have been developed <strong>to</strong> achieve <strong>the</strong>se objectives<br />

for <strong>the</strong> treatment of organic wastes.<br />

262 Industrial-scale production in world's largest biogas plant, Federal Ministry of Economics and Technology, Germany.<br />

263 100% Biogas for Urban Transport in Linkoping, Sweden, IEA Biogas Network.<br />

264 Renewables target <strong>to</strong> be extended <strong>to</strong> at least 35%, ENDS Report 402, pp 38-39.<br />

265 Injection of Biogas in<strong>to</strong> <strong>the</strong> Natural Gas Grid in Laholm, Sweden, IEA Biogas Network, http://www.ieabiogas.net/Dokumente/casestudies/sucess_laholm.pdf<br />

266 Gasrec, boc and SITA UK announce first fuel production at biomethane project in Albury, Surrey, Site Press Release 2008.<br />

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Open Composting Systems<br />

Most compost is generated through open air techniques, which places <strong>the</strong> organic waste in piles exposed<br />

<strong>to</strong> <strong>the</strong> air. The waste is commonly formed in<strong>to</strong> elongated triangular piles that are called windrows, which<br />

allow optimum exposure <strong>to</strong> <strong>the</strong> atmosphere whilst minimising <strong>the</strong> land area taken up. Once <strong>the</strong> waste is<br />

prepared for composting <strong>the</strong> principal control mechanism for <strong>the</strong> process is <strong>the</strong> air requirement of <strong>the</strong><br />

micro-organisms and <strong>the</strong> dissipation of <strong>the</strong> heat generated. Introduction of air in<strong>to</strong> <strong>the</strong> waste can be<br />

achieved ei<strong>the</strong>r though active pumping of air in<strong>to</strong> <strong>the</strong> waste or through <strong>the</strong> mechanical lifting and mixing of<br />

<strong>the</strong> waste <strong>to</strong> introduce air in<strong>to</strong> <strong>the</strong> pile. These two approaches are called static aerated pile and turned<br />

windrow.<br />

Windrow composting is well established in <strong>the</strong> UK with a large number of facilities treating source<br />

separated garden waste. Such systems for green wastes are typically quoted at between £20 and £25/t<br />

of waste treated although <strong>the</strong>re is strong regional effects due <strong>to</strong> <strong>the</strong> potential for markets of <strong>the</strong> compost.<br />

In-Vessel Composting Systems<br />

Reac<strong>to</strong>r or enclosed composting is a relatively new composting development that provides a faster active<br />

biodegradation process, reducing <strong>the</strong> area required. The use of a ‘closed’ vessel allows much greater<br />

control over <strong>the</strong> process and this helps both with <strong>the</strong> speed of <strong>the</strong> process but also <strong>the</strong> consistency<br />

(hence quality) of <strong>the</strong> compost product.<br />

The reac<strong>to</strong>rs come in a variety of forms and have varying degrees of au<strong>to</strong>mation. However, <strong>the</strong> basis of<br />

reac<strong>to</strong>r composting is that materials are enclosed in a drum, silo, or similar structure and air is injected<br />

in<strong>to</strong> <strong>the</strong> composting material <strong>to</strong> maintain <strong>the</strong> optimum conditions for composting.<br />

Following <strong>the</strong> foot and mouth outbreak in 2001, any waste which contains or could contain meat or meat<br />

products has <strong>to</strong> be treated at a certain temperature for a minimum period of time, thus any source<br />

separated waste which includes <strong>the</strong> collection of kitchen waste from households, would need <strong>to</strong> be<br />

composted in an in-vessel system.<br />

In-vessel composting facilities are not as well established, with less than 20 operational in <strong>the</strong> UK. These<br />

systems are more expensive than windrow systems with potential gate fees in <strong>the</strong> range £35-£50/t of<br />

waste treated. However, in Europe <strong>the</strong> number of facilities is large with in-vessel composting becoming<br />

<strong>the</strong> norm for organic wastes o<strong>the</strong>r than green garden wastes.<br />

Outputs<br />

Compost is stabilised organic material consisting of <strong>the</strong> refrac<strong>to</strong>ry and slowly degradable cellulosic<br />

components. The main use of this compost is as a soil improver.<br />

The quality of <strong>the</strong> compost is largely determined <strong>by</strong> <strong>the</strong> feeds<strong>to</strong>ck provided <strong>to</strong> <strong>the</strong> process. Relatively<br />

uncontaminated feeds<strong>to</strong>cks will give rise <strong>to</strong> uncontaminated products and <strong>the</strong>se are generally composted<br />

from source-separated materials. The residues from <strong>the</strong> composting process are those materials that do<br />

not <strong>read</strong>ily degrade, such as wood and <strong>the</strong>se can ei<strong>the</strong>r be returned <strong>to</strong> <strong>the</strong> front of <strong>the</strong> process <strong>to</strong> be<br />

shredded or <strong>the</strong>y can be disposed of.<br />

The ratio of soil improver product <strong>to</strong> reject fractions will vary markedly with <strong>the</strong> feeds<strong>to</strong>ck and process but<br />

typically <strong>the</strong> product material might only be 50 <strong>to</strong> 60% of <strong>the</strong> incoming waste with 15-30% loss of mass<br />

through <strong>the</strong> biodegradation for source separated materials whilst residual (mixed waste) compost may<br />

only generate 10-20% compost product with up <strong>to</strong> 60% being reject <strong>to</strong> landfill.<br />

9.2.1 Composting of MSW<br />

The use of composting schemes is growing, especially as <strong>the</strong> organic fraction of MSW <strong>to</strong> landfill must be<br />

reduced. While composting does not produce ei<strong>the</strong>r energy or fuels from waste, it does produce a viable<br />

product as an output, and it gives an indication of <strong>the</strong> proportion of organic material, largely from MSW,<br />

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In 2006-07 3.6M <strong>to</strong>nnes of source segregated waste was composted, a 5% increase on <strong>the</strong> previous<br />

year. 267 The vast majority of this waste is from MSW, and of this 48% was from civic amenity sites while<br />

46% was from kerbside collections.<br />

There are many composting sites in <strong>the</strong> UK, of varying sizes, types and longevity. Identifying a complete<br />

list of sites is difficult as many waste opera<strong>to</strong>rs are experimenting with this process, and so sites are<br />

developing rapidly at <strong>the</strong> moment, as decisions are taken on whe<strong>the</strong>r <strong>to</strong> pursue this disposal method.<br />

Some of <strong>the</strong> better known examples of large scale composting sites in <strong>the</strong> UK are:<br />

Table 71 Large scale composting examples in <strong>the</strong> UK<br />

Name and Location Volume Operational<br />

Glasgow Fruit Market,<br />

Glasgow 268<br />

2,000 <strong>to</strong>nnes p.a.<br />

2005<br />

Council run and output is<br />

sold.<br />

Twycross Zoo,<br />

Warwickshire 269<br />

Lynnbot<strong>to</strong>m, Isle of<br />

Wight 270<br />

St. Ives,<br />

Cambridgeshire 271<br />

Whar<strong>to</strong>n,<br />

Herefordshire 272 *<br />

Enclosed composting of waste<br />

fruit, vegetables, paper, card and<br />

pallet wood<br />

800 <strong>to</strong>nnes p.a.<br />

Enclosed composting of animal<br />

wastes and garden waste.<br />

Up <strong>to</strong> 60 <strong>to</strong>nnes per day<br />

Originally composting of garden<br />

waste in windorws. More recently<br />

taking food waste in-vessel.<br />

100,000 <strong>to</strong>nnes p.a.<br />

Conversion of kitchen and green<br />

waste in 4 composting tunnels, 2<br />

of which are part of Defra<br />

Demonstra<strong>to</strong>r Programme.<br />

10,000 <strong>to</strong>nnes p.a.<br />

In vessel anaerobic digestion<br />

technique <strong>to</strong> compost garden and<br />

kitchen waste. Also one of <strong>the</strong><br />

Defra Demonstra<strong>to</strong>r Programmes.<br />

2008<br />

1992<br />

2002<br />

Parham, Suffolk 273 * Site takes garden and food<br />

waste, shredded paper and<br />

cardboard, from Suffolk Coastal<br />

District Council<br />

2006<br />

* The operating company went in<strong>to</strong> administration in February 2009, at which point <strong>the</strong> site in Parham was<br />

taken over <strong>by</strong> Country Style group and continues <strong>to</strong> operate.<br />

267 Compost Information Sheet, Waste Online, http://www.wasteonline.org.uk/resources/InformationSheets/Compost.htm<br />

268 Chronicle of Glasgow’s Fish, Fruit and Flower Markets,<br />

http://www.glasgow.gov.uk/en/Business/Markets/chronicleofglasgowsfishfruitvegetableandflowermarket.htm<br />

269 Twycross Zoo Recycles Poo! http://www.twycrosszoo.com/news/currentnews.htm<br />

270 Lynnbot<strong>to</strong>m Composting Facility, http://www.wrightenvironmental.com/pdf/IsleofWight_print.pdf<br />

271 Envar, Services, Composting, http://www.envar.co.uk/services/composting.html?menu_pos=services<br />

272 Bioganix Research Limited, Defra Factsheet, http://www.defra.gov.uk/environment/waste/wip/newtech/dem-programme/pdf/Bioganix.pdf<br />

273 Greenprint Forum and Green Issues Task Group visit <strong>the</strong> Parham Compost Facility,<br />

http://www.suffolkcoastal.gov.uk/yourdistrict/greenissues/greenprint/forum/parhamvisit/default.htm<br />

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Upcoming projects include <strong>the</strong> Mytum & Sel<strong>by</strong> site, which is constructing a 25,000 <strong>to</strong>nnes per annum<br />

facility, due <strong>to</strong> be operatational <strong>by</strong> Oc<strong>to</strong>ber 2009. Phase two would see this capacity increase <strong>to</strong> 75,000<br />

<strong>to</strong>nnes per annum. 274<br />

9.3 Hydrolysis and fermentation of lignocellulose<br />

(Biological 2nd Generation Biofuel)<br />

Wood<br />

waste,<br />

Agricultural<br />

/ cereal<br />

waste<br />

Pre<br />

treatment<br />

Hydrolysis/<br />

saccharification<br />

Fermentation<br />

Process Description<br />

Most ethanol is produced industrially <strong>by</strong> <strong>the</strong> fermentation of sugars <strong>by</strong> yeasts or bacteria although a small<br />

quantity is produced <strong>by</strong> <strong>the</strong> hydration of ethylene. The most common processes use simple sugars such<br />

as sucrose that <strong>the</strong> organisms can easily process. These sugars are found in food crops, ei<strong>the</strong>r directly<br />

as in sugar cane and beet, or as starch in grain that is converted <strong>to</strong> sugar <strong>by</strong> <strong>the</strong> action of an enzyme.<br />

Wood and <strong>the</strong> stem material of plants - lignocellulosic material - are also composed <strong>to</strong> a large extent of<br />

sugars and are much more abundant. However <strong>the</strong>se sugars are unsuitable for fermenting organisms<br />

and locked in<strong>to</strong> <strong>the</strong> plant structure.<br />

Lignocellulosic material contains two sugars, cellulose and hemi-cellulose, both in polymer form. They<br />

are enclosed <strong>by</strong> coating of lignin, a compound with no sugars that gives <strong>the</strong> plant its structural strength.<br />

To obtain fermentable sugars it is first necessary <strong>to</strong> release <strong>the</strong> cellulose and hemi-cellulose from <strong>the</strong><br />

lignin and <strong>the</strong>n hydrolyse <strong>the</strong>m <strong>to</strong> simple sugars. These can <strong>the</strong>n be fermented <strong>by</strong> yeasts, or more<br />

usually, bacteria <strong>to</strong> produce ethanol.<br />

The generic flowsheet for this process has four sequential steps covering a pre-treatment step <strong>to</strong> release<br />

lignin and hydrolyse <strong>the</strong> hemicellulose, hydrolysis of <strong>the</strong> cellulose <strong>to</strong> simple sugars, fermentation, and<br />

purification of <strong>the</strong> ethanol produced. Of <strong>the</strong>se steps pre-treatment and hydrolysis have proved technically<br />

<strong>the</strong> most difficult and <strong>the</strong> subject of most research and development.<br />

Pretreatment. The first operations are normally physical treatments <strong>to</strong> reduce <strong>the</strong> size and increase <strong>the</strong><br />

surface area of <strong>the</strong> feeds<strong>to</strong>ck that improve its accessibility <strong>to</strong> <strong>the</strong> reagents used. Washing may also be<br />

necessary for some feeds<strong>to</strong>cks, and steaming followed <strong>by</strong> solvent washing has been proposed <strong>to</strong> remove<br />

resins that may inhibit <strong>the</strong> later biological processes.<br />

Normally <strong>the</strong> breaking of <strong>the</strong> structure is achieved <strong>by</strong> a dilute acid that will break <strong>the</strong> lignin free from <strong>the</strong><br />

structure <strong>to</strong> liberate <strong>the</strong> sugars, and at <strong>the</strong> same time hydrolyse <strong>the</strong> hemi-cellulose polymer <strong>to</strong> simpler<br />

274 Mytum & Sel<strong>by</strong> plans £45m waste-<strong>to</strong>-biofuel plant, Letsrecycle.com 13 th March 2009.<br />

Purification<br />

Ethanol


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Xylose and 5 carbon sugars. Some cellulose will also be converted <strong>to</strong> 6 carbon sugars, but most will be<br />

hydrolysed in <strong>the</strong> following stage.<br />

Physical methods have also been proposed for pre-treatment, usually in combination with dilute acid<br />

treatment, <strong>the</strong> most common being steam explosion where <strong>the</strong> slurry in <strong>the</strong> pre-treatment stage is flashed<br />

<strong>to</strong> low pressure through a choke causing <strong>the</strong> cell structure <strong>to</strong> burst during decompression. The same<br />

explosive decompression effect has been demonstrated using ammonia and CO2 as <strong>the</strong> medium.<br />

A consequence of <strong>the</strong> acidic conditions is that some of <strong>the</strong> sugars will be converted <strong>to</strong> furfans and o<strong>the</strong>r<br />

compounds that may inhibit <strong>the</strong> fermentation organisms in a later stage. A key development challenge for<br />

process designers is <strong>to</strong> minimise <strong>the</strong> production of inhibi<strong>to</strong>rs whilst maximising <strong>the</strong> yield of simple sugars.<br />

Acid will need <strong>to</strong> be recovered and sugars washed from <strong>the</strong> process and <strong>the</strong> liquor neutralised following<br />

pre-treatment. Lignin is also removed at this stage. Most developers propose <strong>to</strong> use this as a fuel for<br />

power and process heat generation.<br />

Cellulose Hydrolysis. Pre-treatment is followed <strong>by</strong> a second hydrolysis stage where <strong>the</strong> cellulose is<br />

converted <strong>to</strong> 6 carbon sugars. His<strong>to</strong>rically this has been achieved <strong>by</strong> acid hydrolysis using a higher<br />

temperature but lower concentration acid than in <strong>the</strong> pre-treatment step. An alternative route is <strong>to</strong> use<br />

concentrated acids which improves <strong>the</strong> yield of sugar but is critically dependent for its economics on<br />

effective recovery and reuse of <strong>the</strong> acid. This is technically possible but difficult and involves complex<br />

engineering.<br />

Acid based processes have been proven for many years but only now are demonstrations being planned<br />

in <strong>the</strong> USA and <strong>the</strong> EU. This lack of progress has been his<strong>to</strong>rically due <strong>to</strong> <strong>the</strong> expensive equipment<br />

necessary and <strong>the</strong> low price of competing ethanol from sugar and grain. Only with <strong>the</strong> recent interest in<br />

ethanol as a biofuel has development restarted on this process.<br />

Following hydrolysis <strong>the</strong> process will include separation stages <strong>to</strong> wash out <strong>the</strong> sugars and remove<br />

fermentation inhibi<strong>to</strong>rs such as heavy metal contaminants and organic products of hydrolysis followed <strong>by</strong><br />

neutralisation with lime if acid has been used.<br />

In <strong>the</strong> last decade, an alternative, enzyme hydrolysis route has been proposed and developed <strong>to</strong> pilot<br />

stage. This technology has <strong>the</strong> potential <strong>to</strong> achieve high conversion rates with low production of inhibi<strong>to</strong>rs<br />

due <strong>to</strong> <strong>the</strong> mild reaction conditions. The key development necessary for commercialisation is <strong>to</strong> reduce<br />

<strong>the</strong> cost of <strong>the</strong> enzyme cellulase <strong>by</strong> an order of magnitude. Enzyme based processes are still in <strong>the</strong><br />

development phase but offer <strong>the</strong> prospect of being economically more attractive than o<strong>the</strong>r options if <strong>the</strong>ir<br />

fur<strong>the</strong>r development is successful. Demonstrations are planned in Canada, USA and EU.<br />

Fermentation.<br />

The sugars from ei<strong>the</strong>r hydrolysis route contain five and six carbon a<strong>to</strong>ms and need <strong>to</strong> be fermented in a<br />

microbial process ra<strong>the</strong>r than <strong>the</strong> yeast process used for simple sugars from sugar beet, sugar cane and<br />

grains. Typically <strong>the</strong>se are proprietary recombinant organisms whose metabolisms have been tailored <strong>to</strong><br />

<strong>the</strong> sugars in <strong>the</strong> process. We understand work is also being carried out on advanced yeasts.<br />

Development status<br />

A substantial research programme has been underway for over a decade in <strong>the</strong> USA and EU <strong>to</strong><br />

commercialise this technology. 275 This has resulted in several demonstration plants, but as yet no <strong>full</strong>y<br />

commercial installations. 276 Progress has been made however and <strong>the</strong> US have announced a target of<br />

producing ethanol from lignocellulose <strong>to</strong> <strong>the</strong> same price as that from corn <strong>by</strong> 2012.<br />

275 IEA (2008) From first <strong>to</strong> second generation biofuel technologies: An over view of current industry and R,D & D activities<br />

276 www.abc-energy.at/biotreibs<strong>to</strong>ffe/demoplants.php.<br />

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Current key <strong>to</strong>pics for research are <strong>the</strong> improvement of <strong>the</strong> organisms used in <strong>the</strong> process <strong>to</strong> improve<br />

yields and efficiency and <strong>the</strong> combination of several processes in <strong>the</strong> same unit operation <strong>to</strong> reduce<br />

capital costs.<br />

Current plans in <strong>the</strong> USA indicate that one of <strong>the</strong> most promising configurations for a demonstration will<br />

be <strong>to</strong> install <strong>the</strong> hydrolysis stages on a corn ethanol site <strong>to</strong> process <strong>the</strong> maize harvesting residue.<br />

Scale of operation – Regional<br />

The reliance on clean feeds<strong>to</strong>ck would suggest that this would be a regional technology drawing from<br />

agricultural residues such as straw and chipped wood fuels. The low bulk densities would tend <strong>to</strong> reduce<br />

<strong>the</strong> economic transport radius. However <strong>the</strong> process involves complex process engineering which<br />

responds well <strong>to</strong> <strong>the</strong> economies of scale.<br />

Hydrolysis feed s<strong>to</strong>cks<br />

Feed s<strong>to</strong>cks for hydrolysis based processes need <strong>to</strong> be clean waste, virgin wood or agricultural residues.<br />

The microbial fermentation is susceptible <strong>to</strong> poisoning if contaminated waste biomass is used as a<br />

feeds<strong>to</strong>ck.<br />

Table 72 The suitability of feeds<strong>to</strong>cks for hydrolysis processes<br />

SRF<br />

Waste<br />

Wood<br />

Clean<br />

Wood<br />

Domestic<br />

Pellet<br />

Industrial<br />

Pellet<br />

Unsorted<br />

Waste<br />

Wet<br />

Wastes<br />

Agricultural<br />

Residues<br />

<br />

T C Fuels – Thermochemical Fuels<br />

A contrary view on <strong>the</strong> necessity for clean feeds<strong>to</strong>cks is taken <strong>by</strong> Aquegen who propose using MSW<br />

fractions at <strong>the</strong>ir installation <strong>to</strong> be built in <strong>the</strong> UK at South Milford in West Yorkshire. The chemical<br />

process appears <strong>to</strong> be acid hydrolysis of <strong>the</strong> cellulose and hemi cellulose but <strong>the</strong> impact on <strong>the</strong><br />

fermentation stage is unclear and operating data is scarce.<br />

UK Biomass <strong>to</strong> Ethanol Plant<br />

Mytum and Sel<strong>by</strong> have planning permission for <strong>the</strong> creation of a biomass <strong>to</strong> ethanol facility at South<br />

Milford in West Yorkshire, as a joint venture with AqueGen. The intended site will be capable of<br />

processing 400,000 <strong>to</strong>nnes of waste food, ABP (Animal By Product) and liquids in<strong>to</strong> 100 million litres of<br />

alcohol each year. It is hoped that <strong>the</strong> site will be operational <strong>by</strong> 2011. 274<br />

Table 73 Risks Associated with Ethanol from lignocellulose waste<br />

Level of Risk Comment<br />

Technical High The technology remains innovative with only small<br />

demonstration and pilot projects built so far.<br />

Feeds<strong>to</strong>cks are currently limited <strong>to</strong> clean wood and<br />

agricultural residues. Contamination from o<strong>the</strong>r<br />

sources could damage <strong>the</strong> fermentation process.<br />

Social & Planning Medium Process should be no more difficult <strong>to</strong> implement<br />

than a biomass power plant.<br />

Implementation is likely <strong>to</strong> be on an existing grain<br />

ethanol site<br />

Financial High The combination of expensive processing and <strong>the</strong><br />

need for good quality feeds<strong>to</strong>ck means that<br />

product will be more expensive than imported<br />

ethanol for some time. Plant economics will be<br />

sensitive <strong>to</strong> price competition for feeds<strong>to</strong>ck and<br />

competition from improved cane sugar ethanol<br />

processes for final product. This may make it<br />

T C<br />

Fuels


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Level of Risk Comment<br />

unsuitable for use in <strong>the</strong> UK.<br />

Regula<strong>to</strong>ry Medium Would require additional subsidy from Renewable<br />

transport fuels obligation.<br />

9.4 Conclusions for Biological Processes<br />

Biological processes for waste include anaerobic digestion for <strong>the</strong> production of methane fuel gas and <strong>the</strong><br />

hydrolysis and subsequent fermentation <strong>to</strong> ethanol fuels of <strong>the</strong> hemi-cellulose and cellulose fractions of<br />

lignocellulosic materials.<br />

Following our review of <strong>the</strong>se technologies our conclusions are as follows;<br />

• Anaerobic digestion processes are technically viable and available for most wet waste feeds<strong>to</strong>cks<br />

including sewage bio-solids.<br />

• There is much discussion concerning whe<strong>the</strong>r AD is economically viable for standard fee waste at<br />

<strong>the</strong> moment. Greater interest in applying this disposal method is being stimulated <strong>by</strong> <strong>the</strong> revised<br />

Waste Framework Directive, and interest in biogas for transport.<br />

• Using a proportion of food waste is important <strong>to</strong> <strong>the</strong> economics of anaerobic digestion due <strong>to</strong> its<br />

high gas generation potential and gate fee. Manures are bulky and have poor gas potential.<br />

• Digestate disposal is becoming difficult due <strong>to</strong> constraints in nitrogen sensitive areas.<br />

• Composting is a lower cost alternative <strong>to</strong> AD but does not produce energy and can be regarded<br />

as a competi<strong>to</strong>r <strong>to</strong> AD. It is popular with waste managers due <strong>to</strong> <strong>the</strong> cost and its status as a<br />

recovery, ra<strong>the</strong>r than a disposal process. Disposal of compost <strong>to</strong> land suffers from <strong>the</strong> same<br />

constraints as AD digestates.<br />

• Hydrolysis and subsequent fermentation <strong>to</strong> ethanol fuels of <strong>the</strong> hemicellulose and cellulose<br />

fractions of lignocellulosic materals is still at <strong>the</strong> development stage although <strong>the</strong>re are plans for<br />

demonstrations in <strong>the</strong> EU and USA.<br />

• Feeds<strong>to</strong>cks are limited at present <strong>to</strong> clean wood and agricultural residues.<br />

o We question whe<strong>the</strong>r hydrolysis and fermentation should be a priority for <strong>the</strong> UK at<br />

present where clean residues are relatively expensive and could potentially be used in<br />

more efficient ways.<br />

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10 Thermochemical processes for generating<br />

energy<br />

Thermochemical processes for <strong>the</strong> generation of energy are taken as gasification and pyrolysis in <strong>the</strong><br />

Chapter. Combustion, gasification and pyrolysis all use heat <strong>to</strong> break down <strong>the</strong> structure of <strong>the</strong> feeds<strong>to</strong>ck<br />

so that <strong>the</strong> chemical energy can be released ei<strong>the</strong>r as heat or a fuel product. The conditions in <strong>the</strong><br />

reac<strong>to</strong>r determine <strong>the</strong> products.<br />

When combustible waste enters a high temperature environment it will first dry and <strong>the</strong>n decompose in<strong>to</strong><br />

volatile gas and char components.<br />

A combustion process is always supplied with an excess of air so <strong>the</strong> char and volatile gas burn<br />

completely. The energy in <strong>the</strong> waste is released within <strong>the</strong> combustion equipment and <strong>the</strong> flue gas<br />

from it. It is recovered as hot water or steam.<br />

Gasification processes use a limited supply of oxidant; usually air, <strong>to</strong> maintain both combustion and<br />

reducing reactions in <strong>the</strong> same reac<strong>to</strong>r. These reactions produce carbon monoxide (CO), hydrogen<br />

(H2) and hydrocarbons as well as combustion products. Most of <strong>the</strong> energy in <strong>the</strong> fuel is transferred<br />

in<strong>to</strong> <strong>the</strong> calorific value (CV) of <strong>the</strong> gas leaving <strong>the</strong> reac<strong>to</strong>r. This gas can be burned separately in a<br />

boiler, engine or gas turbine. Alternatively it can be converted <strong>by</strong> a syn<strong>the</strong>sis reaction <strong>to</strong> methane for<br />

injection <strong>to</strong> <strong>the</strong> Natural Gas Grid or liquid fuels for transport.<br />

In a pyrolysis process <strong>the</strong>re is no oxygen and <strong>the</strong> char and volatile gas remain largely unchanged.<br />

The energy in <strong>the</strong> waste is retained in <strong>the</strong> CV of <strong>the</strong> gas and char removed from <strong>the</strong> reac<strong>to</strong>r. These<br />

can <strong>the</strong>n be burned separately in a boiler, engine or gas turbine. Some pyrolysis processes produce<br />

gases that can be condensed in<strong>to</strong> a liquid fuel. Pyrolysis products can also be fur<strong>the</strong>r upgraded <strong>to</strong><br />

transport fuels although <strong>the</strong> technologies required are not yet commercially available.<br />

There are a number of advantages of converting solid waste in<strong>to</strong> a gas or liquid fuel.<br />

• Cleaning a small fuel gas stream before combustion ra<strong>the</strong>r than a large flue gas flow as in an<br />

incinera<strong>to</strong>r reduces <strong>the</strong> size of <strong>the</strong> pollution control equipment.<br />

• The controlled combustion in a gas flame, as opposed <strong>to</strong> a grate, may also reduce <strong>the</strong> extent and<br />

complexity of final gas cleaning.<br />

• The two points above make installations economically possible that are smaller than current<br />

incinera<strong>to</strong>rs. These should be more acceptable for permitting and more compatible with <strong>the</strong><br />

throughputs of <strong>the</strong> newer mechanical separation and o<strong>the</strong>r recycling and recovery processes.<br />

• Higher electrical output per <strong>to</strong>nne is possible if high-pressure boilers, gas turbines or engines are<br />

used.<br />

• Alternative energy products such as methane and liquid fuels can be manufactured <strong>by</strong> chemical<br />

syn<strong>the</strong>sis using <strong>the</strong> products of gasification or pyrolysis as a base.<br />

In <strong>the</strong> sections below we discuss how <strong>the</strong>rmal technologies are used <strong>to</strong> generate energy from waste,<br />

what demands <strong>the</strong>y make of <strong>the</strong> feeds<strong>to</strong>ck, <strong>the</strong>ir commercial status and <strong>the</strong> risks of deployment.<br />

These advantages are often quoted <strong>by</strong> gasification and pyrolysis suppliers as solutions for perceived<br />

weaknesses in <strong>the</strong> current market leader – combustion with energy recovery. These claims are shown in<br />

Table 74 with our comments.


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Table 74 Claims for gasification/pyrolysis with comments<br />

Incineration Gasification/pyrolysis Comment<br />

Large (Regional) size and<br />

fuel demand suppresses<br />

recycling.<br />

Small volume of Hazardous<br />

and <strong>to</strong>xic fly ash.<br />

Bulky residual ash can be<br />

used as a aggregate.<br />

Poor electrical efficiency<br />

and lack of suitable heat<br />

loads gives poor resource<br />

use efficiency.<br />

Can be built economically at<br />

<strong>the</strong> smaller sizes that can be<br />

integrated in<strong>to</strong> local<br />

schemes.<br />

This remains <strong>to</strong> be<br />

demonstrated, but is<br />

probably true.<br />

No dioxin found in fly ash. This seems <strong>to</strong> be valid.<br />

Some options give low<br />

volume compact ash.<br />

Some options can give very<br />

high electrical efficiencies.<br />

Smaller sizes can match heat<br />

loads better. Particularly as<br />

<strong>the</strong>se are often independent<br />

of <strong>the</strong> power supply.<br />

Electricity and or heat only Some options can be used <strong>to</strong><br />

generate gas or transport<br />

fuels<br />

10.1 Gasification<br />

RDF<br />

Waste wood<br />

Clean wood<br />

Ag residues<br />

Gasification<br />

Syn gas<br />

Valid. Some incinera<strong>to</strong>rs can<br />

give low volume slag like ash<br />

but at a very high energy cost<br />

for ash melting.<br />

Very few demonstrations of<br />

high electrical efficiency.<br />

Lack of enthusiasm for CHP.<br />

Installations in wood waste<br />

sec<strong>to</strong>r now making progress.<br />

True at very large scale.<br />

Process Description<br />

In simple terms gasification is <strong>the</strong> conversion of a solid fuel <strong>to</strong> a gas that has sufficient energy value <strong>to</strong> be<br />

useful as a fuel or feeds<strong>to</strong>ck in its own right.<br />

This concept is refined in <strong>the</strong> definition for <strong>the</strong> Renewables Obligation <strong>to</strong> <strong>the</strong> subs<strong>to</strong>ichiometric oxidation<br />

or steam reformation of a substance <strong>to</strong> produce a gaseous mixture containing two or all of <strong>the</strong> following:<br />

oxides of carbon, methane and hydrogen and which has a gross calorific value of at least 4.0 MJ/m 3 when<br />

sampled at <strong>the</strong> inlet <strong>to</strong> <strong>the</strong> genera<strong>to</strong>r and measured at 0.1 MPa and 25°C. 277<br />

277 Renewables Obligation: Defining <strong>the</strong> different types of electricity generation using biomass and waste www.berr.gov.uk<br />

Methanation<br />

Grid Injected<br />

SNG<br />

Fischer<br />

Tropsch<br />

CHP<br />

2 nd gen<br />

biofuels<br />

Heat,<br />

Power<br />

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Gasification has been success<strong>full</strong>y used with coal, in <strong>the</strong> American Great Plains project <strong>to</strong> generate<br />

syn<strong>the</strong>tic natural gas and in South Africa <strong>to</strong> generate transport fuels. There are also instances<br />

internationally where gasification has been used with SRF waste as a feeds<strong>to</strong>ck.<br />

A gasification for energy process has four steps, <strong>the</strong> gasifier itself that produces <strong>the</strong> gas, feeds<strong>to</strong>ck<br />

preparation <strong>to</strong> get <strong>the</strong> fuel in <strong>the</strong> right form for <strong>the</strong> gasifier, <strong>the</strong> clean-up of <strong>the</strong> gas, and <strong>the</strong> utilisation of<br />

<strong>the</strong> clean gas for energy. This is shown Figure 19.<br />

Step<br />

Material<br />

state<br />

Typical<br />

equipment<br />

and<br />

process<br />

Step 1<br />

Pretreatment<br />

Step 2<br />

Thermal<br />

reac<strong>to</strong>r<br />

Step 3<br />

Gas<br />

conditioning<br />

Solid Waste Raw gas<br />

Clean Gas<br />

Separation<br />

of glass and<br />

metals.<br />

Screening<br />

Shredding<br />

Pelleting or<br />

briquetting<br />

Fluidised<br />

bed reac<strong>to</strong>rs<br />

Externally<br />

heated<br />

reac<strong>to</strong>rs<br />

Fixed bed<br />

reac<strong>to</strong>rs<br />

Entrained<br />

flow<br />

reac<strong>to</strong>rs<br />

Gas<br />

coolers<br />

Filters<br />

Liquid<br />

scrubbers<br />

Figure 19 Steps in a gasification process<br />

Step 4<br />

Conversion<br />

<strong>to</strong> energy<br />

Energy<br />

products<br />

Steam<br />

boilers<br />

Engines<br />

Gas<br />

turbines<br />

Chemical<br />

syn<strong>the</strong>sis<br />

The gasification process<br />

The gasification reactions that produce <strong>the</strong> fuel gas components are endo<strong>the</strong>rmic and need a constant<br />

supply of heat <strong>to</strong> sustain production. This heat is supplied <strong>by</strong> <strong>the</strong> combustion of part of <strong>the</strong> fuel. The<br />

challenge is for <strong>the</strong> equipment design <strong>to</strong> transfer heat from exo<strong>the</strong>rmic combustion <strong>to</strong> endo<strong>the</strong>rmic<br />

gasification. There are two main types although <strong>the</strong>re are many variants in each category.<br />

Direct – This process occurs in a single reac<strong>to</strong>r where oxygen or air and usually superheated steam is<br />

supplied <strong>to</strong> <strong>the</strong> same vessel so that some combustion occurs in situ providing <strong>the</strong> required heat <strong>to</strong> drive<br />

<strong>the</strong> gasification reactions. The direct use of air dilutes <strong>the</strong> product gas and results in a low calorific value<br />

fuel commonly referred <strong>to</strong> as producer gas.<br />

Indirect – Here gasification and combustion process occur in separate fluid bed reac<strong>to</strong>rs. Heat is usually<br />

transferred <strong>by</strong> circulating <strong>the</strong> fluidised bed material between <strong>the</strong> two beds. This concept is more complex<br />

than <strong>the</strong> direct process but produces a gas with a higher calorific value.


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Table 75 Gas compositions of typical gasifier types<br />

Compound Typical indirect<br />

(Gussing twin<br />

fluid bed)<br />

% <strong>by</strong> volume<br />

Typical Direct<br />

(Downdraft fixed<br />

bed)<br />

% <strong>by</strong> volume<br />

Direct bubbling<br />

fluid bed<br />

% <strong>by</strong> volume<br />

Carbon monoxide 22.7 % 21.4 %v 11-15 %v<br />

Hydrogen 31.5 %v 15.38 %v 8-13 %v<br />

Methane 11.2 %v 2.05 %v 5-8 %v<br />

Higher hydrocarbons 4.0 %v 0.5-1.5 %v<br />

Carbon dioxide 27.4 %v 11.82 %v 14-16 %v<br />

Nitrogen & Oxygen 2.8% 49.35% 35-45 %v<br />

Water vapour As dry As dry 14-21 %v<br />

LHV, kJ/Nm 3<br />

12,000 - 13,000 5,005 –5,200-5,800<br />

There are a wide variety of commercial processes on <strong>the</strong> market. The list below gives <strong>the</strong> basic generic<br />

types.<br />

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Table 76 Generic gasifier types<br />

Type Description Direct/<br />

indirect<br />

Fixed bed Fuel, air and <strong>the</strong> produced gas flow co currently direct<br />

downdraft downwards through a reac<strong>to</strong>r with a converging<br />

base section.<br />

Fixed bed updraft Fuel and air flow counter currently through a<br />

cylindrical bed.<br />

direct<br />

Fluidised bed The waste is gasified in a hot bed of sand or direct<br />

direct<br />

limes<strong>to</strong>ne that is agitated <strong>by</strong> air and <strong>the</strong> gas product.<br />

This is known as a fluidised bed. Char burns in situ<br />

<strong>to</strong> provide heat. The fluidised bed can be retained<br />

within <strong>the</strong> reac<strong>to</strong>r vessel as a coherent bed with only<br />

gas and dust leaving or <strong>the</strong> velocity of <strong>the</strong> gas can<br />

be increased <strong>to</strong> <strong>the</strong> point that bed material is<br />

transported from <strong>the</strong> <strong>to</strong>p of <strong>the</strong> vessel necessitating<br />

its recirculation back <strong>to</strong> <strong>the</strong> reac<strong>to</strong>r. These two<br />

patterns are respectively referred <strong>to</strong> as bubbling<br />

and circulating fluidised beds.<br />

Fluidised bed The waste is gasified in a turbulent bed of sand or indirect<br />

indirect<br />

limes<strong>to</strong>ne. Char from <strong>the</strong> reaction is transferred with<br />

sand <strong>to</strong> a separate vessel where it is burned in air.<br />

Heat is transferred <strong>by</strong> sand circulation. As with <strong>the</strong><br />

direct type <strong>the</strong> fluidised beds can be bubbling or<br />

circulating.<br />

Heated kilns The waste is tumbled in a rotating drum heated <strong>by</strong><br />

<strong>the</strong> combustion of some of <strong>the</strong> product gas<br />

indirect<br />

Small heated tubes The waste is progressed <strong>by</strong> a screw or ram through<br />

a tube heated <strong>by</strong> <strong>the</strong> combustion of some of <strong>the</strong><br />

product gas.<br />

indirect<br />

Large heated tubes The waste is progressed <strong>by</strong> a screw or ram through<br />

a tube heated <strong>by</strong> <strong>the</strong> combustion of some of <strong>the</strong><br />

product gas.<br />

Indirect<br />

Large entrained Finely divided or liquid fuel is gasified as a flame direct<br />

flow<br />

with oxygen.<br />

Plasma gasification High temperature plasma from an electric arc<br />

dissociates <strong>the</strong> waste in<strong>to</strong> its component molecules<br />

Direct<br />

Feeds<strong>to</strong>cks<br />

The feeds<strong>to</strong>ck quality requirements depend on <strong>the</strong> size and <strong>the</strong> design of <strong>the</strong> gasification process. While<br />

most <strong>the</strong>rmal gasification processes work best with dry regularly sized feeds<strong>to</strong>cks <strong>the</strong>re are some limited<br />

examples of processes that will accept unsorted MSW. In general, <strong>the</strong> smaller <strong>the</strong> gasification unit, <strong>the</strong><br />

more stringent <strong>the</strong> quality requirements will be for <strong>the</strong> feeds<strong>to</strong>ck being used. The requirements for each<br />

of <strong>the</strong> types identified above are summarised below.


Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Wastes and Energy<br />

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Table 77 Gasifier feeds<strong>to</strong>ck requirements<br />

Gasifier<br />

Type<br />

Fixed bed<br />

downdraft<br />

Typical<br />

Size MW<br />

fuel<br />

1 MW<br />

modules<br />

Fixed bed 10 MW<br />

updraft modules<br />

Fluidised 25MW<br />

bed direct or upwards<br />

indirect<br />

Heated kilns 20MW<br />

modules<br />

Small<br />

heated<br />

tubes<br />

Large<br />

heated<br />

tubes<br />

Large<br />

entrained<br />

flow<br />

10 MW<br />

modules<br />

Fuel Quality<br />

Regularly<br />

sized, dry and<br />

clean wood<br />

chips with low<br />

ash. Possibly<br />

pellets<br />

Wood chip<br />

SRF<br />

Waste Wood<br />

Clean Wood<br />

<br />

most qualities <br />

Most dry<br />

shredded<br />

materials<br />

Most shredded<br />

materials not<br />

necessarily dry<br />

Most dry<br />

shredded<br />

materials not<br />

necessarily dry<br />

50MW Minimally<br />

sorted or<br />

prepared<br />

100 MW<br />

upwards<br />

Plasma 2MW<br />

upwards<br />

T C Fuels – Thermochemical Fuels<br />

materials<br />

Capable of<br />

high pressure<br />

pneumatic<br />

transport or<br />

slurry<br />

component<br />

Most shredded<br />

materials not<br />

necessarily dry<br />

Domestic Pellet<br />

Industrial Pellet<br />

Unsorted Waste<br />

Wet Wastes<br />

Agricultural<br />

Residues<br />

T C Fuels<br />

<br />

<br />

<br />

<br />

<br />

<br />

With <strong>the</strong> exception of <strong>the</strong> direct fluidised beds none of <strong>the</strong> gasification processes above can be<br />

considered <strong>to</strong> be widely available commercially. The allocation of feeds<strong>to</strong>ck is <strong>the</strong>refore an estimate<br />

based on AEA knowledge.<br />

Primary Gas Cleaning<br />

The gas from <strong>the</strong> gasifier contains a range of contaminants. The most important are dust and residual<br />

organic compounds or tars that can cause difficulties for <strong>the</strong> following conversion process. The extent of<br />

cleaning necessary varies with <strong>the</strong> end use of <strong>the</strong> gas, so a fluidised bed gasifier supplying hot gas <strong>to</strong> a<br />

coal fired utility boiler will have minimal dust removal whereas a unit supplying gas <strong>to</strong> a reciprocating<br />

engine will need reliable dust, tar and acid gas removal. Syn<strong>the</strong>sis processes require a very high level of<br />

purity <strong>to</strong> avoid poisoning of <strong>the</strong> catalysts used in <strong>the</strong> reactions - <strong>the</strong>se are more properly regarded as part<br />

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of <strong>the</strong> syn<strong>the</strong>sis package and so will be described below in that section. The requirements for <strong>the</strong> more<br />

demanding end uses have been summarised <strong>by</strong> <strong>the</strong> Karlsruhe Institute of Technology. 278 .<br />

Cleaning processes, especially those for <strong>the</strong> tars, have proved exceptionally difficult <strong>to</strong> design and<br />

implement in practice and are <strong>the</strong> principal cause of project failure where engines and gas turbines are<br />

used.<br />

Options that have shown success are:<br />

For tar removal<br />

• Catalytic cracking or steam reforming on limes<strong>to</strong>ne or nickel catalysts. (VTT, Condens)<br />

• Filtration on ceramic filter with limes<strong>to</strong>ne precoat. (Gussing, Biomass Engineering)<br />

• Liquid scrubbing with vegetable oil or biodiesel. (Gussing, Xylowatt)<br />

• Wet electrostatic precipita<strong>to</strong>rs (REFgas)<br />

• Plasma reaction chamber. (Europlasma)<br />

For dust removal<br />

• Ceramic, or sintered metal filters (Guessing, Biomass Engineering)<br />

• Cyclones<br />

• Liquid scrubbers with vegetable oil or biodiesel. (Gussing, Xylowatt)<br />

• Plasma reaction chamber. (Europlasma)<br />

Table 78 Syngas trace contaminants and target levels in ppm 278<br />

mg/Nm 3 Biomass<br />

gasification<br />

Gas mo<strong>to</strong>r Gas turbine MeOH FT (Sasol)<br />

Particles 10 4 – 10 5 < 50 < 1 0.2 n.s.<br />

Tar 0 – 20,000 < 100 < 5 < 1 n.s.<br />

Alkali 0.5 – 5 n.s. < 0.2 < 0.2 < 0.01<br />

NH3, HCN 200 – 2000 < 55 n.s. < 0.1 < 0.02<br />

H2S, COS 50 – 100 < 1150 < 1 < 0.1 < 0.01<br />

Halogens 0 – 300 n.s. < 1 < 0.1 < 0.01<br />

Heavy<br />

Metals<br />

0.005 - 10 n.s. n.s. n.s. < 0.001<br />

n.s = not specified<br />

Gas conversion<br />

The clean gas has many uses. It can be burned directly, <strong>to</strong> provide heat, raise steam, or drive electrical<br />

genera<strong>to</strong>rs. It can also be used as a feeds<strong>to</strong>ck for fur<strong>the</strong>r processes <strong>to</strong> syn<strong>the</strong>sise methane, diesel fuel<br />

components and o<strong>the</strong>r chemicals and fuels.<br />

Without doubt <strong>the</strong> most successful application <strong>to</strong> date has been <strong>the</strong> direct combustion of gas in industrial<br />

processes and boilers.<br />

The most quoted example of process use is <strong>the</strong> use of fluidised bed gasifiers producing low calorific gas<br />

for heating lime kilns in <strong>the</strong> paper and pulp industry. Typically <strong>the</strong> gas is burned through a burner nozzle<br />

designed for <strong>the</strong> low calorific value directly in<strong>to</strong> <strong>the</strong> combustion chamber of <strong>the</strong> process unit. One unit in<br />

Varo Sweden has been operating since 1987. 279<br />

Gas can also be used <strong>to</strong> raise steam in a boiler which can in turn be used for power generation. This is a<br />

robust concept that carries much less technical risk than <strong>the</strong> use of engines or gas turbines. Prime<br />

examples of this are those processes based on an externally heated reac<strong>to</strong>r with all <strong>the</strong> heat release in a<br />

278 IEA Bioenergy Agreement Task 33 Spring 2009 Workshop, Karlsruhe, www.gastechnology.org/iea German country update<br />

279 IEA Bioenergy Agreement Task 33 Spring 2009 Workshop, Karlsruhe, www.gastechnology.org/iea Swedish country update.


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high temperature combustion chamber followed <strong>by</strong> a boiler (Ethos Energy, Thermoselect, Mitsui MES<br />

R21). These have all proved reliable in commercial service and delivered substantial emissions benefits.<br />

A special case of this is <strong>the</strong> use of gas for firing district heating plant. Through <strong>the</strong> 1980’s a Finnish<br />

company, Bioneer, installed a series of updraft gasifiers linked directly <strong>to</strong> hot water heating boilers in<br />

Finland and Sweden. These were very successful and reliable but development s<strong>to</strong>pped after <strong>the</strong><br />

company was sold <strong>to</strong> a major engineering concern.<br />

There are plans <strong>to</strong> implement a project in east London (ELSEF) that will use a fluidised bed gasifier,<br />

fuelled <strong>by</strong> SRF from a neighbouring waste management facility. Here <strong>the</strong> gas would be cleaned of acid<br />

gas components which allows <strong>the</strong> use a much higher pressure boiler and turbine than would be possible<br />

with a combustion plant and hence potential for higher electrical efficiency in power and CHP cycles.<br />

A fur<strong>the</strong>r related application that is enjoying considerable success is <strong>the</strong> use of a circulating fluidised bed<br />

gasifier close-coupled <strong>to</strong> a coal fired boiler. Three installations have been built: Lahti in Finland, Amer in<br />

Ne<strong>the</strong>rlands and Electrobel Ruien in Belgium. These units take a wide range of feeds<strong>to</strong>cks from SRF <strong>to</strong><br />

waste woods and plastics. The first installation of this type, Lahti in Finland was commissioned in 1998<br />

and has operated reliably since. Details of all of <strong>the</strong>se installations can be found on <strong>the</strong> IEA Bioenergy<br />

Agreement Task 32 database of cofiring installations 280 . The inherent simplicity of this approach and it’s<br />

ability <strong>to</strong> make use of <strong>the</strong> high efficiency steam cycle of <strong>the</strong> fossil fuel plant is attractive and fur<strong>the</strong>r<br />

installations are planned in Finland and Sweden. 279<br />

A class of installations that is enjoying some success in <strong>the</strong> UK is <strong>the</strong> close coupled gasifier and boiler,<br />

where waste is burned directly after production. This does not allow for acid gas removal but ensures<br />

that <strong>the</strong> gas is burned in a well developed and controlled flame that reduces o<strong>the</strong>r emissions <strong>to</strong> a low<br />

level. One of <strong>the</strong> most developed version is <strong>the</strong> Energos gasifier which is demonstrating a unit on <strong>the</strong> Isle<br />

of Wight as part of <strong>the</strong> Defra WIP. 281 Fur<strong>the</strong>r replications are planned in <strong>the</strong> UK. The controlled nature of<br />

<strong>the</strong> gasification and combustion reactions mean that this type of unit can be designed <strong>to</strong> burn sorted<br />

MSW and SRF in smaller heat and CHP installations than grate and fluidised bed combus<strong>to</strong>rs which<br />

means <strong>the</strong>y can be used <strong>to</strong> power industrial heat and high load chp installations that have high GHG<br />

abatement potential. A fur<strong>the</strong>r example of this type of technology is <strong>the</strong> Bioflame unit which is currently<br />

being marketed <strong>to</strong> produce CHP using waste wood chip as a fuel. 282<br />

Using <strong>the</strong> gas <strong>to</strong> generate electricity from combustion in a reciprocating engine or gas turbine has proved<br />

problematical and <strong>the</strong>re are very few examples of a <strong>full</strong>y commercial, reliable system operating <strong>to</strong>day.<br />

The obstacle is cleaning <strong>the</strong> gas of <strong>the</strong> tar and dust contamination that can damage <strong>the</strong> engine. This<br />

apparently simple task has defeated many engineers over several decades. There has however been<br />

some progress over <strong>the</strong> last five years;<br />

• At Gussing in Austria an indirect gasifier has been operating for over 20k hours fuelling a 2.5<br />

MWe reciprocating engine. The key <strong>to</strong> success here appears <strong>to</strong> be <strong>the</strong> combination of a ceramic<br />

filter with a liquid scrubber containing biodiesel.<br />

• Biomass Engineering Ltd in <strong>the</strong> UK have installed three downdraft/ engine systems in Germany<br />

that are generating reliably as CHP units supplying district heating. The key here seems <strong>to</strong> be<br />

close control over <strong>the</strong> feeds<strong>to</strong>ck sizing and quality combined with <strong>the</strong> use of a ceramic filter.<br />

• At Harboore in Denmark a fixed bed gasifier supplies three reciprocating engines in a local district<br />

heating system. Tar cleaned from <strong>the</strong> fuel gas is s<strong>to</strong>red and subsequently fired in a boiler <strong>to</strong> even<br />

out peaks in heating demand.<br />

280 http://www.ieabcc.nl/database/cofiring.php<br />

281 Lets recycle Tuesday 18 September 2007.<br />

282 http://www.bioflame.co.uk/<br />

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10.1.1 Using <strong>the</strong> gas <strong>to</strong> syn<strong>the</strong>sise fur<strong>the</strong>r products.<br />

As noted above <strong>the</strong> gas produced <strong>by</strong> gasifiers can be used <strong>to</strong> manufacture methane or transport fuels. A<br />

review of gasifier technologies, with a focus on those suitable for liquid fuel production from syngas, has<br />

been recently released <strong>by</strong> NNFCC. 283 Nitrogen dilution is not acceptable in this type of application and<br />

this route is restricted <strong>to</strong> direct gasifiers using oxygen as an oxidant and indirect gasifiers.<br />

Transport fuels produced <strong>by</strong> Fischer Tropsch syn<strong>the</strong>sis reactions are endo<strong>the</strong>rmic using syn-gas<br />

(syn<strong>the</strong>tic gas) <strong>to</strong> produce long chain hydrocarbons that can be distilled <strong>to</strong> produce transport fuels or<br />

intermediates for chemical processing. These reactions commonly require carbon monoxide, carbon<br />

dioxide and hydrogen in specific proportions. These proportions are adjusted <strong>by</strong> use of <strong>the</strong> shift reaction.<br />

The resulting gases are <strong>the</strong>n catalysed at temperatures of 150°C – 300°C, and elevated pressures <strong>by</strong> an<br />

iron or cobalt catalyst.<br />

CO + H2O ↔ CO2 + H2<br />

Shift Reaction<br />

(2n+1)H2 + nCO ↔ CnH(2n+2) + nH2O<br />

Fischer-Tropsch Reaction<br />

Methanation is an exo<strong>the</strong>rmic process that uses syn gas <strong>to</strong> produce methane that can be injected in<strong>to</strong> <strong>the</strong><br />

gas grid. Syn gas is catalytically reacted with steam at temperatures between 340°C – 550°C and up <strong>to</strong><br />

60 bar.<br />

CO + 3H2 ↔ CH4 + H2O<br />

A fur<strong>the</strong>r variation is <strong>the</strong> syn<strong>the</strong>sis of methanol which in turn can be converted <strong>to</strong> a range of organic<br />

chemicals and dimethyl e<strong>the</strong>r, potentially a fuel used in diesel engines. Nickel is commonly used as <strong>the</strong><br />

catalyst. These reactions commonly require carbon monoxide, carbon dioxide and steam in tightly<br />

controlled proportions which are obtained <strong>by</strong> <strong>the</strong> shift reaction and carbon dioxide absorption. Carbon<br />

dioxide removal is done <strong>by</strong> amine solvent scrubbing or refrigerated methanol scrubbing, both commercial<br />

refinery and gasworks processes. The use of catalysts requires a high level of purity from trace<br />

contamination, particularly sulphur and metals that must be removed <strong>to</strong> single ppm levels. This is usually<br />

done <strong>by</strong> passing over beds of zinc and copper oxide.<br />

The methanation reaction is highly exo<strong>the</strong>rmic and rejects heat at <strong>the</strong> reaction temperature of over 340°C.<br />

This makes it a useful source of process steam and in <strong>the</strong> past commercialisation of this technology has<br />

often been driven <strong>by</strong> <strong>the</strong> desire <strong>to</strong> use this <strong>to</strong> <strong>the</strong> <strong>full</strong>. A process producing 700MW of methane could<br />

produce 200MW of steam.<br />

Neste Oil, S<strong>to</strong>ra Enso, VTT and Forest Wheeler are exploring ways <strong>to</strong> transform wood waste in <strong>to</strong><br />

transport fuels through a Fischer-Tropsch process <strong>to</strong> give a usable syn-gas at a demonstration plant in<br />

Varkaus, Finland. 284 The plant is due <strong>to</strong> open in Spring of 2009, and will use forest residues such as<br />

branches, stumps and trimmings <strong>to</strong> generate heat and electricity for <strong>the</strong> attached papermill, and quantities<br />

of biowax, <strong>the</strong> raw material <strong>to</strong> be refined in<strong>to</strong> transport fuels and its use is <strong>to</strong> replace food oils. The facility<br />

is expected <strong>to</strong> have a capacity of around 100,000 <strong>to</strong>nnes p.a. of biowax.<br />

283 Review of Technologies for Gasification of Biomass and Wastes, NNFCC and E4Tech, June 2009.<br />

284 Transforming wood waste in<strong>to</strong> renewable fuel, http://www.nesteoil.com/default.asp?path=1,41,540,10793,10795,11601


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Table 79 Scales of operation<br />

Direct Downdraft <strong>to</strong><br />

CHP<br />

Local Regional National<br />

Updraft <strong>to</strong> CHP<br />

Fluid bed <strong>to</strong><br />

CHP and power<br />

only<br />

Updraft <strong>to</strong> CHP<br />

Indirect Fluid bed <strong>to</strong><br />

CHP<br />

Indirectly heated<br />

tubes and kilns<br />

for CHP and<br />

power only<br />

Oxygen blown<br />

entrained flow <strong>to</strong><br />

methane and 2 nd<br />

Gen Biofuels<br />

Fluid bed <strong>to</strong><br />

methane<br />

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Table 80 Risks and barriers associated with Gasification<br />

Local Scale<br />

Level of<br />

Risk<br />

Comment<br />

Technical High Very few operating commercial plant for power<br />

or CHP.<br />

Significant residual risk in gas cleaning for<br />

power production.<br />

Social & Planning Medium Likely <strong>to</strong> be located on an industrial site where<br />

impacts can be minimised.<br />

Financial High Poor track record of gasification technologies<br />

Regula<strong>to</strong>ry Medium Receives subsidy via <strong>the</strong> Renewables<br />

Obligation.<br />

Status of ash product is unclear under Waste<br />

Incineration Directive due <strong>to</strong> high carbon<br />

content<br />

Regional scale<br />

Level of<br />

Risk<br />

Comment<br />

Technical High Very few operating commercial plant for power<br />

or CHP.<br />

Significant residual risk in gas cleaning for<br />

power production.<br />

Substantially lower risk for gas combustion in<br />

boilers and process units.<br />

Social & Planning High High where process is used <strong>to</strong> produce<br />

electricity on a regional basis as it will be<br />

perceived as an untried form of incinera<strong>to</strong>r.<br />

Financial High Poor track record of gasification technologies.<br />

Regula<strong>to</strong>ry Medium Receives subsidy via <strong>the</strong> Renewables<br />

Obligation. Status of ash product is unclear<br />

under Waste Incineration Directive due <strong>to</strong> high<br />

carbon content.<br />

National scale<br />

Level of<br />

Risk<br />

Comment<br />

Technical Medium Little experience of biomass gasification for<br />

this application but substantial coal<br />

experience.<br />

Closely allied <strong>to</strong> refinery practice.<br />

Social & Planning Low Low for syn gas production at large scale on a<br />

petrochemical complex.<br />

Financial Medium Poor track record of gasification technologies<br />

but developers are likely <strong>to</strong> be substantial and<br />

have track record of delivery.<br />

Regula<strong>to</strong>ry Medium Receives subsidy via <strong>the</strong> Renewable transport<br />

fuels obligation. Risk for change in long lead<br />

time for build.


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10.1.2 Examples of gasification of MSW in <strong>the</strong> UK<br />

Gasification<br />

The Energos gasifier in Newport on <strong>the</strong> Isle of Wight began processing waste in mid 2008, <strong>the</strong> first<br />

example in <strong>the</strong> UK, and part of Defra’s New Technologies Demonstra<strong>to</strong>r Programme. 285 It will potentially<br />

consume 30,000 <strong>to</strong>nnes per annum of floc: an SRF baled fuel comprised of waste paper, plastic and<br />

packaging sorted from MSW. It is estimated <strong>to</strong> have a calorific content of 11-14MJ/kg. The gasification<br />

process used is a two-stage process where first <strong>the</strong> floc fuel is burnt in oxygen depleted conditions such<br />

that a gas is created. This is <strong>the</strong>n transferred <strong>to</strong> an oxidation chamber where it is <strong>full</strong>y oxidised in a<br />

controlled environment. The resulting heat from <strong>the</strong> flue gases is recovered and used <strong>to</strong> generate<br />

electricity. It is expected that <strong>the</strong> site will produce 2.3MW of electricity, and be able <strong>to</strong> deliver 1.8MW <strong>to</strong><br />

<strong>the</strong> community for use.<br />

Scotgen is part way through <strong>the</strong> construction of 40,000 <strong>to</strong>nne per annum gasification plant at Dargavel,<br />

near Dumfries. The site was due <strong>to</strong> open in March, with commissioning expected <strong>to</strong> begin in November<br />

of this year. The anticipated electrical output is 6 MW. 286<br />

A fur<strong>the</strong>r gasification site is proposed at Der<strong>by</strong>shire, UK, capable of generating 8MW of electricity through<br />

<strong>the</strong> processing of 140,000 <strong>to</strong>nnes of waste. This is joint venture between United Utilities and Interserve<br />

using Energos technology.<br />

Plasma Gasification<br />

Enviroparks Ltd, an energy company based in South Wales, have announced plans <strong>to</strong> build a number of<br />

waste treatment centres in <strong>the</strong> UK, each incorporating a plasma gasifier. The first identified site is <strong>to</strong> be<br />

at Hirwaun in Wales, and will incorporate six separate processes including recycling, material recovery<br />

and AD <strong>to</strong> treat <strong>the</strong> majority of <strong>the</strong> waste, with plasma gasification used for <strong>the</strong> residual components.<br />

It is intended that <strong>the</strong> site will process municipal and light industrial waste, converting <strong>the</strong> residual waste<br />

<strong>to</strong> an estimated 120,000MW of electricity through generation of a BioSynGas, refined through <strong>the</strong> use of<br />

plasma <strong>to</strong>rches, which will <strong>the</strong>n be used <strong>to</strong> drive a gas turbine potentially achieving efficiencies of<br />

electricity generation of 40%. This site intends <strong>to</strong> use <strong>the</strong> GHO-Power technology. The first of four<br />

announced sites <strong>to</strong> use GHO-Power technology from French company EuroPlasma, is at Morcenx in<br />

France, a 12MW power plant that will use 55,000 <strong>to</strong>nnes of general industrial waste per annum.<br />

Construction began in late 2008, and <strong>the</strong> site is intended <strong>to</strong> be operational in January 2010.<br />

10.1.3 Examples of gasification of waste wood in <strong>the</strong> UK<br />

A downdraft Gasifier plant in Tunstall, S<strong>to</strong>ke-on-Trent has been developed <strong>by</strong> Biomass Engineering Ltd<br />

and owned <strong>by</strong> O-Gen <strong>to</strong> utilise waste wood in combination with forestry wood and energy crops, intended<br />

<strong>to</strong> begin operation in 2007 and generate 8 MW of electricity. The systems uses a three-stage process,<br />

requiring fuel preparation (size and moisture), wood gasification and finally power and heat generation<br />

through combustion of <strong>the</strong> gases produced. 287<br />

Ano<strong>the</strong>r gasifier site, built <strong>by</strong> Biomass Engineering Ltd, that makes use of clean waste wood is located at<br />

Mossborough Hall in Merseyside. It is capable of generating 250kW of electricity and was connected <strong>to</strong><br />

<strong>the</strong> grid in 2005. 288<br />

285<br />

Defra Factsheet, Waste Gas Technology UK Limited (WGT), http://www.defra.gov.uk/environment/waste/wip/newtech/demprogramme/pdf/Energos.pdf<br />

286<br />

Scotgen, http://www.scotgenltd.co.uk/<br />

287<br />

O-Gen’s First Timber Resource Recovery Centre, 13/09/07, http://www.biomass.uk.com/case-study-article.php?id=172<br />

288<br />

Green Energy UK Newsletter, 2005, Mossborough Hall.<br />

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10.1.4 International Situation<br />

Gasification<br />

There are a few projects using <strong>the</strong> Energos technology for example <strong>the</strong> plant at Averøy in Norway. The Averøy plant<br />

opened in 2000 and processes 30,000 <strong>to</strong>nnes of MSW each year, <strong>the</strong> power output of which is used <strong>by</strong> a<br />

neighbouring fac<strong>to</strong>ry. 289 A fur<strong>the</strong>r Energos site in Norway is in Forus, receiving 40,000 <strong>to</strong>nnes per annum<br />

of residual waste since 2002.<br />

Japan has an established his<strong>to</strong>ry of gasification, with <strong>the</strong> first Thermoselect plant built at Chiba in 1999 <strong>by</strong><br />

Kawasaki Steel Corporation (now known as JFE). There are now seven plants (a <strong>to</strong>tal of 16 Thermoselect<br />

units) in operation with a <strong>to</strong>tal daily capacity of nearly 2,000 <strong>to</strong>nnes. The availability of <strong>the</strong> operating<br />

plants is about 80%. The syngas produced in <strong>the</strong> Thermoselect furnace is quenched and cleaned before<br />

it is used in gas turbines or engines. The amount of useful gas produced per <strong>to</strong>nne of MSW processed is<br />

much lower than in conventional combustion and steam generation units as cleaning a reducing gas is<br />

more complex than for combustion process gas.<br />

In <strong>the</strong> Thermoselect process waste is pushed through a heated tube. The residual char is gasified and<br />

<strong>the</strong> gases mixed, <strong>the</strong> gasification agent is oxygen which gives a high enough temperature <strong>to</strong> convert <strong>the</strong><br />

ash <strong>to</strong> slag. The mixed gases <strong>the</strong>n pass through a waste heat boiler and scrubber before being burned in<br />

a steam boiler.<br />

Currently electrical efficiencies are ra<strong>the</strong>r low at but <strong>the</strong> Japanese licensee is carrying out trials using <strong>the</strong><br />

higher calorific value gases from <strong>the</strong> reac<strong>to</strong>r with reciprocating engines and fuel cells ra<strong>the</strong>r than boilers,<br />

which should significantly improve <strong>the</strong> electrical efficiency of <strong>the</strong> process.<br />

Table 81 Thermoselect facility locations and specifications in Japan<br />

City<br />

Startup<br />

year<br />

Design<br />

Capacity<br />

(<strong>to</strong>nnes/day)<br />

Feeds<strong>to</strong>ck Syngas use<br />

Power<br />

generated<br />

Chiba 1999 2 x 165<br />

MSW +<br />

Gas engine at steelworks<br />

Industrial Waste<br />

NA<br />

Mutsu 2003 2 x 70 MSW Gas engines<br />

2 x 1.2<br />

MW<br />

Kurashiki 2005 3 x 185<br />

MSW +<br />

Gas engine at steelworks<br />

Industrial Waste<br />

NA<br />

Isahaya 2005 3 x 100 MSW Gas engines<br />

5 x 1.6<br />

MW<br />

Yokushima 2005 2 x 60 MSW Gas engines<br />

0.9 x 2<br />

MW<br />

Izumi 2005 1 x 95 Industrial Waste Boiler/Steam Turbine 1.7MW<br />

Yorii 2006 3 x 150<br />

MSW +<br />

Industrial Waste<br />

Boiler/Steam Turbine 10.5 MW<br />

Ebara’s TwinRec is a fluidized bed gasification process with ash vitrification, designed for material<br />

recycling, energy recovery and de<strong>to</strong>xification of wastes. 290 This process is capable of treating shredded<br />

residues, waste plastics, electrical waste, industrial wastes, MSW and bio-solids. The gasifier allows<br />

separates <strong>the</strong> non-combustible portion, such as metallic proportions of <strong>the</strong> waste from <strong>the</strong> combustible<br />

portion. The former is recycled as valuable products from <strong>the</strong> bot<strong>to</strong>m off-stream of <strong>the</strong> gasifier, and <strong>the</strong><br />

latter is transferred as ash, char and combustible gas <strong>to</strong> <strong>the</strong> second stage. In <strong>the</strong> second stage, fuel gas<br />

289 Homes <strong>to</strong> be powered <strong>by</strong> green power from waste, 16.04.2008, Ener.g, http://www.energ.co.uk/?OBH=490&ID=143<br />

290 TwinRec Gasification and Ash Melting Technology – Now also established for Municipal Waste , A. Selinger, Ch. Steiner and K. Shin EBARA<br />

Corporation, WASTE 2003: 4th Int. Symposium on Waste Treatment Technologies,<br />

http://www.ebara.ch/downloads/EBARA%20Manuscript%20Sheffield%20IChemE%202003.pdf


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and combustible material produced from <strong>the</strong> gasifier are burnt <strong>to</strong>ge<strong>the</strong>r in a cyclonic ash melting chamber<br />

at temperatures between 1350-1450ºC <strong>by</strong> <strong>the</strong> addition of secondary air. The particles are <strong>the</strong>n collected<br />

on <strong>the</strong> walls, where <strong>the</strong>y are vitrified and proceed slowly through <strong>the</strong> furnace.<br />

The good quality recovered metal components are sold in<strong>to</strong> <strong>the</strong> metal markets. The molten glass<br />

products fulfil <strong>the</strong> stringent Japanese soil standard and are sold <strong>to</strong> <strong>the</strong> construction industry. The energy<br />

content of <strong>the</strong> shredder residue is converted <strong>to</strong> electricity and sold <strong>to</strong> <strong>the</strong> grid.<br />

There are numerous TwinRec Fluidized Bed and Gasification facilities in Japan. Several examples are:<br />

• Ube City plant has a capacity of 8.3 <strong>to</strong>nnes per hour over three process lines and has been<br />

commercial operation since 2003. The electricity output of <strong>the</strong> plant in is 4MW. 291<br />

• Seki City plant has a capacity of 7 <strong>to</strong>nnes per hour, in commercial operation since 2003, with an<br />

electricity output.<br />

• Recently, <strong>the</strong> Kawaguchi plant was started, treating 18 <strong>to</strong>nnes per hour of municipal solid waste<br />

in three process lines (3 x 21 MW).<br />

Foster Wheeler, Lahti, Finland<br />

Lahti is a small <strong>to</strong>wn <strong>to</strong> <strong>the</strong> north of Helsinki. The <strong>to</strong>wn authority operates a 350MWth coal and natural<br />

gas fired CHP installation that provides electricity and district heating for <strong>the</strong> <strong>to</strong>wn. A 50MWth fuel-gas<br />

burner, supplied <strong>by</strong> a circulating fluid bed gasifier (see Figure 20), has been installed in place of one of<br />

<strong>the</strong> pulverised coal burners. A wide range of shredded fuels have been used with considerable success.<br />

Typical fuels are sorted domestic waste, tyres and plastic bottles, sleepers, debarker residues and<br />

sawdust. The feeds<strong>to</strong>ck is blended in an ‘A’ frame s<strong>to</strong>rage building with a traversing screw discharge.<br />

No gas clean up is used, acid gas emissions are controlled <strong>by</strong> source separation of <strong>the</strong> feeds<strong>to</strong>ck and<br />

dust from <strong>the</strong> gasifier is carried forward in<strong>to</strong> coal fired boiler and mixes with <strong>the</strong> coal ash.<br />

A detailed case study for this installation and a similar installation at Zeltweg in Austria have been<br />

prepared <strong>by</strong> <strong>the</strong> IEA Thermal Treatment of Waste Task.<br />

291 Ube, Japan, Plant Sheet, http://www.ebara.ch/downloads/ebara_plant_sheet_ube_twinrec.pdf<br />

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Figure 20 Gasifier used at Lahti<br />

Bioflow, Värnamo, Sweden<br />

Bioflow Ltd (a joint venture of Foster Wheeler and Sydkraft) has operated a demonstration plant<br />

producing approx. 6 MWe and 9 MWth for district heating. This plant has been operated using a variety<br />

of fuels, including RDF, but it is likely that <strong>the</strong> system will be targeted at biomass fuels. It is included here<br />

as an example of <strong>the</strong> concept of integrating gasification with combined cycle power generation <strong>to</strong> achieve<br />

higher electrical conversion efficiencies.<br />

The operating temperature of <strong>the</strong> gasifier is 950-1000°C at an approximate pressure of 20-22 bar. The<br />

gasifier system is based on <strong>the</strong> CFB principle (see Figure 20) with integrated cyclone and cyclone return<br />

leg. The three parts (gasifier, cyclone, cyclone return leg) are <strong>to</strong>tally refrac<strong>to</strong>ry lined. Following <strong>the</strong><br />

cyclone, <strong>the</strong> fuel-gas produced is led <strong>to</strong> a cooler and a hot gas filter. The gas cooler is of a fire tube<br />

design and cools <strong>the</strong> gas <strong>to</strong> a temperature of approximately 350°C prior <strong>to</strong> entering <strong>the</strong> filter. Following<br />

<strong>the</strong> filter <strong>the</strong> fuel-gas is burned in <strong>the</strong> combustion chambers of a single shaft industrial turbine (Als<strong>to</strong>m<br />

Typhoon). The hot flue gas from <strong>the</strong> gas turbine is ducted <strong>to</strong> <strong>the</strong> heat recovery steam genera<strong>to</strong>r.<br />

This process has <strong>the</strong> potential <strong>to</strong> deliver <strong>the</strong> highest electrical efficiency of all <strong>the</strong> options described here<br />

(40%). To do this however would require a suitable waste treatment plant <strong>to</strong> remove and recycle plastics<br />

and metals and supply a consistent fibrous fuel.<br />

SVZ Swartzepompe, Saxony, Germany<br />

This large chemical complex was built originally <strong>to</strong> convert brown coal in<strong>to</strong> a range of chemicals and fuels<br />

as part of <strong>the</strong> energy system of <strong>the</strong> former DDR (East Germany). With reunification <strong>the</strong> plant was<br />

success<strong>full</strong>y modified <strong>to</strong> accept industrial and domestic waste. In its current configuration it comprises<br />

seven fixed bed, steam/oxygen blown gasifiers operating at 25 bar and fed <strong>by</strong> a mixture of waste and<br />

coal. The complex also includes two oxygen-blown, entrained flow gasifiers that accept liquid and slurry


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wastes. The company has plans <strong>to</strong> complete <strong>the</strong> installation of a larger fixed bed British Gas/Lurgi<br />

slagging gasifier.<br />

The medium CV product gas is cleaned and used <strong>to</strong> generate electricity, through a combined cycle using<br />

a 44 MWe Als<strong>to</strong>m Turbine and a 30 MWe steam turbine. There are plans <strong>to</strong> syn<strong>the</strong>sise methanol <strong>to</strong><br />

enhance <strong>the</strong> degree of recycling that can be achieved in <strong>the</strong> installation.<br />

Current capacities are<br />

• Plastics 5 <strong>to</strong>nnes/hr<br />

• Wood 6 <strong>to</strong>nnes/hr<br />

• Liquid waste 200 <strong>to</strong>nnes/day<br />

• Domestic waste 20 <strong>to</strong>nnes/ hr<br />

All residues leave <strong>the</strong> site as inert slag<br />

This project represents a technically viable waste disposal and energy complex on a very large scale. It<br />

is an engineering success that combines a high degree of material recovery with a high electrical<br />

efficiency. It did however make substantial use of <strong>the</strong> existing brown coal processing plant so replication<br />

may prove difficult.<br />

Choren, Freiberg, Germany<br />

CHOREN Gmbh have been developing a process <strong>to</strong> produce a renewable fuel compatible with <strong>the</strong> diesel<br />

fuel infrastructure that uses lignocellulose materials. The concept is <strong>to</strong> gasify biomass and use <strong>the</strong><br />

resultant gas as a feeds<strong>to</strong>ck <strong>to</strong> syn<strong>the</strong>sise alkanes using <strong>the</strong> Fischer Tropsch reaction.<br />

The process for <strong>the</strong> gasification of wood and similar materials is based on an entrained flow gasifier used<br />

for brown coal in <strong>the</strong> 1980’s in <strong>the</strong> former DDR. The gasification process comprises two steps, slow<br />

pyrolysis of chipped material followed <strong>by</strong> <strong>the</strong> oxygen gasification of <strong>the</strong> tar vapours and char produced.<br />

The oxygen gasifier is interesting in that it is arranged in two stages; <strong>the</strong> first gasifies <strong>the</strong> pyrolysis<br />

vapours in oxygen and <strong>the</strong> second gasifies <strong>the</strong> char <strong>by</strong> reaction with <strong>the</strong> product gases from <strong>the</strong> first<br />

stage, having first been finely ground. A consequence of <strong>the</strong> second reaction is that <strong>the</strong> gasses are<br />

cooled <strong>by</strong> <strong>the</strong> endo<strong>the</strong>rmic reaction of char with CO2.<br />

The syn<strong>the</strong>sis gas from <strong>the</strong> gasifier is essentially free from tar contamination and can be cleaned <strong>by</strong><br />

filtration before <strong>the</strong> CO/H2 ratio is adjusted using <strong>the</strong> CO shift reaction. CO2 is <strong>the</strong>n removed <strong>by</strong> scrubbing<br />

and <strong>the</strong> gas passed fur<strong>the</strong>r in<strong>to</strong> <strong>the</strong> Fischer Tropsch reac<strong>to</strong>r <strong>to</strong> form a product mixture of diesel oil and<br />

naphtha.<br />

The first installation was a pilot, or alpha, plant which operated from <strong>the</strong> mid 90’s <strong>to</strong> 2005 and had a fuel<br />

input of 1MW. The second, or beta, installation is a demonstration with a fuel input of 45MW and is just<br />

undergoing commissioning and testing near Freiberg in Saxony. The third installation, or sigma, is a <strong>full</strong><br />

scale commercial unit of 640 MW which is in <strong>the</strong> design phase and should enter service in 2015.<br />

The overall energy balance of <strong>the</strong> beta demonstration unit is predicted <strong>to</strong> convert 100% fuel energy value<br />

<strong>to</strong> 39% diesel, 13% naphtha, and 6% export electricity giving an overall efficiency of 58% fuel <strong>to</strong> energy<br />

product. This is expected <strong>to</strong> improve with scale up.<br />

The development of <strong>the</strong> process is being supported <strong>by</strong> a consortium of Daimler Chrysler, Shell,<br />

Volkswagen, and o<strong>the</strong>rs with assistance from local German authorities and <strong>the</strong> EU. 292<br />

292 Start-up of <strong>the</strong> first commercial BTL production facility. Lecture <strong>by</strong> Dr. Chris<strong>to</strong>ph Kiener, Project Development Manager at <strong>the</strong> 16th European<br />

Biomass Conference & Exhibition, 3. June 2008, Valencia. www.choren.com<br />

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Plasma Gasification<br />

Plasma gasification is <strong>the</strong> gasification of matter in an oxygen-free environment <strong>to</strong> decompose waste<br />

material in<strong>to</strong> its basic molecular structure. It does not rely on incineration but converts organic waste in<strong>to</strong><br />

a fuel gas and inorganic waste in<strong>to</strong> an inert vitrified glass. In Japan <strong>the</strong> biggest industrial unit of its kind<br />

operates at <strong>the</strong> Eco-Valley site at Utashinai, Hokkaido plasma facility, built <strong>by</strong> Hitachi Metals. It began<br />

processing MSW in 2003 with a capacity of approximately 200-280 <strong>to</strong>ns per day. 293 It uses 8 Marc-3a<br />

plasma systems with <strong>to</strong>rches that are rated for 300 KW, operating at 2 gasification islands, each with 4<br />

<strong>to</strong>rches. The system delivers 1.5MW of net electricity output <strong>to</strong> <strong>the</strong> grid, 294 although <strong>the</strong> facility wasn’t<br />

designed with maximum power output in mind. If it had been, <strong>the</strong> predicted output would be 12MW. 295<br />

A second plasma gasification system operates in Japan, <strong>the</strong> Mihama-Mikata WTE Facility. The system<br />

gasifies 24 tpd of MSW and 4 tpd of waste-water sludge through 2 Marc-3a plasma systems. 294 The heat<br />

output is used within <strong>the</strong> waste water treatment facility.<br />

There are two plasma gasification plants under construction in India, at Pune and Nagpur, both intended<br />

<strong>to</strong> take 72 <strong>to</strong>ns per day of hazardous waste and convert it <strong>to</strong> energy.<br />

A plasma gasifier has planning permission in <strong>the</strong> USA, Florida where it is intended that 3,000 <strong>to</strong>ns per<br />

day of MSW will be converted <strong>to</strong> 120MW of electricity and is expected <strong>to</strong> be operational in 2010. 296<br />

10.2 Pyrolysis<br />

SRF<br />

Waste wood<br />

Clean wood<br />

Pyrolysis<br />

Gas<br />

Pyrolysis oils<br />

Char<br />

Process Description<br />

Pyrolysis is normally defined as <strong>the</strong> <strong>the</strong>rmal degradation of a substance in <strong>the</strong> absence of any oxidising<br />

agent (o<strong>the</strong>r than that which forms part of <strong>the</strong> substance itself) <strong>to</strong> produce char and one or both of gas<br />

and liquid.<br />

The process converts feeds<strong>to</strong>ck waste in<strong>to</strong> char, vapours of complex carbohydrates and permanent<br />

gases, primarily CO, H2, CH4 and CO2. This is done <strong>by</strong> <strong>the</strong> action of heat in oxygen free conditions at<br />

high temperatures between 400°C and 900°C. The proportions of <strong>the</strong> three product classes depend upon<br />

CHP<br />

293 Eco-Valley Waste-<strong>to</strong>-Energy Facility, http://www.alternrg.ca/project_development/commercial_projects/utashinai<br />

294 Alter Nrg and Westinghouse Plasma Corp: The Plasma Gasification Process, February, 2008,<br />

http://www.calgaryregion.ca/crp/media/32152/<strong>the</strong>_alter_nrg_plasma_gasification_process_-_turner_valley_presentation.ppt.pdf<br />

295 Westinghouse Plasma Corporation, Waste Processing, http://www.westinghouse-plasma.com/markets_applications/waste_processing.php<br />

296 Westinghouse Plasma Corporation, www.westinghouse-plasma.com/common/pdfs/WPC.pdf<br />

Slurry<br />

Thermochemical<br />

Fuel<br />

Heat<br />

Power


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<strong>the</strong> temperature of <strong>the</strong> reac<strong>to</strong>r and critically <strong>the</strong> rate at which heat is applied <strong>to</strong> <strong>the</strong> biomass fractions.<br />

Lower temperatures and fast heating rates favour vapours, higher temperatures and high heating rates<br />

gas, low temperature and slow heating rates favour char formation.<br />

There are two main categories of pyrolysis process, but many practical variants within <strong>the</strong>m:<br />

Fast or flash pyrolysis – typically finely divided biomass waste is injected in<strong>to</strong> a fluidised bed of inert<br />

material operating at 500°C. The size of <strong>the</strong> fuel and <strong>the</strong> excellent heat transfer characteristics of <strong>the</strong> fluid<br />

bed ensure a very fast heating rate which maximises <strong>the</strong> production of vapour. The vapour is<br />

subsequently condensed as a liquid that contains approximately 70% of <strong>the</strong> energy value of <strong>the</strong> waste<br />

feeds<strong>to</strong>ck. The <strong>by</strong>-product char and gas is used in part <strong>to</strong> provide heat <strong>to</strong> drive <strong>the</strong> process. The liquid<br />

fuel has been success<strong>full</strong>y used <strong>to</strong> fire boilers and kilns. Trials have been undertaken in reciprocating<br />

engines and gas turbines. Excess char can be sold as a product for activated carbon manufacture or<br />

reducing agent in metal production. The char can also be used as fuel ei<strong>the</strong>r on its own or as a slurry<br />

with <strong>the</strong> pyrolysis liquids.<br />

The main use for fast pyrolysis processes at present is <strong>the</strong> manufacture of speciality chemicals and food<br />

additives although this is expected <strong>to</strong> change <strong>to</strong> energy use when <strong>the</strong> current demonstration plants in<br />

Canada come <strong>full</strong>y on stream.<br />

Slow Pyrolysis – finely diced waste is pyrolysed in ei<strong>the</strong>r in a screw conveyor or reac<strong>to</strong>r vessel that is<br />

indirectly heated. The slower heating rate favours char and liquid production over gas.<br />

Carbonisation – large pieces of waste or wood are heated in a re<strong>to</strong>rt. The heat is provided <strong>by</strong> burning a<br />

proportion of <strong>the</strong> vapour and gas product.<br />

A variation of slow pyrolysis using a heated screw has recently been proposed as a step in <strong>the</strong> production<br />

of <strong>the</strong>rmo chemical fuels in <strong>the</strong> form of a slurry of charcoal and pyrolysis liquid product. The concept is a<br />

series of distributed fuel preparation processes on a local and regional scale that feed supply a very large<br />

gasification plant at national scale. The advantages are reduced transport costs and having <strong>the</strong> fuel in a<br />

form that it can easily be pumped in<strong>to</strong> <strong>the</strong> high pressure (60 bar) processes that are used in this type of<br />

facility.<br />

Feeds<strong>to</strong>cks for Pyrolysis<br />

Currently fast pyrolysis processes are being designed for both clean wood and wood extracted from <strong>the</strong><br />

waste stream. In all cases <strong>the</strong> wood will need <strong>to</strong> be ground <strong>to</strong> less that 3mm particle size before use.<br />

Slow pyrolysis can use a wider variety of solid shredded material including SRF.<br />

Table 82 Risks Associated with Pyrolysis<br />

Level of Risk Comment<br />

Technical High Operating commercial plant in existence for oil<br />

production little experience in energy generation.<br />

Social & Planning High / Low High where process is used <strong>to</strong> produce electricity<br />

at a regional scale where it may be perceived as<br />

an untried and unsafe incinera<strong>to</strong>r.<br />

Low for syn gas production or <strong>the</strong>rmo chemical<br />

fuel production where it wuill be perceived as<br />

ano<strong>the</strong>r industrial process.<br />

Financial High Few suppliers and uneven track record.<br />

Products have no established energy market and<br />

would rely on dedicated cus<strong>to</strong>mer.<br />

Regula<strong>to</strong>ry Medium Receives enhanced subsidy via <strong>the</strong> Renewables<br />

Obligation.<br />

Status of products is unclear.<br />

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10.2.1 Pyrolysis in <strong>the</strong> UK<br />

Seamer Carr, Scarborough<br />

The UK’s first <strong>full</strong> scale waste pyrolysis plant is <strong>to</strong> be known as Scarborough Power Ltd. Once<br />

operational <strong>the</strong> plant will consume 18,000 <strong>to</strong>nnes per annum of high calorific value pre-sorted MSW, i.e. a<br />

form of SRF. 297 After shredding and drying <strong>the</strong> expected calorific content of this material will be 15MJ/kg.<br />

Simple flash pyrolysis, with technology provided <strong>by</strong> GEM, will be used <strong>to</strong> convert <strong>the</strong> waste <strong>to</strong> syngas in<br />

<strong>the</strong> absence of oxygen, which is <strong>the</strong>n ultimately used <strong>to</strong> generate electricity and heat, expected <strong>to</strong> be<br />

2.4MW of electricity and 1.8MW of gross heat output.<br />

This project is a joint venture between Yorwaste, pyrolysis technology company GEM, and engineering<br />

consultancy NEL Power, and is part of Defra’s New Technologies Demonstration Programme.<br />

Compact Power, Avonmouth<br />

The Compact Power process is typical of a heated tube system. The schematic (Figure 21) shows <strong>the</strong><br />

company’s 8,000 <strong>to</strong>nnes per annum demonstration plant at Avonmouth. This plant is intended for <strong>the</strong><br />

treatment of MSW and clinical waste. Waste may be first sorted <strong>to</strong> remove recyclables. It is <strong>the</strong>n<br />

conveyed <strong>by</strong> a screw through a heated tube where it pyrolyses. The pyrolysis gases are <strong>the</strong>n burned in a<br />

cyclone combustion chamber. The residual char falls in<strong>to</strong> a hopper where it is gasified <strong>by</strong> steam that has<br />

been preheated in <strong>the</strong> combustion chamber, leaving an ash residue. The gas from <strong>the</strong> gasification<br />

section is burned with <strong>the</strong> pyrolysis gas. The hot gas from <strong>the</strong> combustion chamber is first used <strong>to</strong> heat<br />

<strong>the</strong> pyrolysis tubes <strong>the</strong>n <strong>to</strong> raise steam for power generation. Flue gas clean up is after <strong>the</strong> boiler and<br />

uses a dry bicarbonate injection system. The residue is <strong>report</strong>ed as a dry, inert gas. The emissions<br />

performance is <strong>report</strong>ed as excellent with most regulated pollutants an order of magnitude below <strong>the</strong><br />

statu<strong>to</strong>ry limit.<br />

The focus is largely on waste disposal at an acceptable cost on a small scale appropriate <strong>to</strong> clinical and<br />

industrial wastes, and smaller urban communities. As such it fits well with recycling schemes. Energy<br />

recovery is currently relatively low and comparable with combustion systems. More development would<br />

be necessary <strong>to</strong> take advantage of <strong>the</strong> higher efficiencies offered <strong>by</strong> gas turbine and reciprocating engine<br />

cycles.<br />

Figure 21 Schematic of Compact Power’s demonstration plant at Avonmouth<br />

297 Defra Factsheet, Scarborough Power, http://www.defra.gov.uk/environment/waste/wip/newtech/dem-programme/pdf/Scarborough-Power.pdf


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The Avonmouth Pyrolysis and Gasification Plant near Bris<strong>to</strong>l, is <strong>the</strong> next step in <strong>the</strong> development path for<br />

this technology but has experienced difficulties with <strong>the</strong> original owners Compact Power went in<strong>to</strong><br />

administration in 2008 and Ethos Recycling bought <strong>the</strong> site. Assuming <strong>the</strong> site does become operational,<br />

it will be capable of processing 30,000 <strong>to</strong>nnes of waste per annum, generating 2,400 kW of electricity and<br />

7,620 kW of heat. 298<br />

10.2.2 International experience<br />

R21 process<br />

Mitsui Babcock Energy runs a number of R21 (Recycling in <strong>the</strong> Twenty First Century) Pyrolysis<br />

Technology facilities in Japan. These facilities rely on a pre-incineration pyrolysis process operated at<br />

low temperature (less than 450ºC) of MSW, which converts poor fuel (such as MSW) in<strong>to</strong> high value<br />

product fuels such as syngas and a solid residue. These products are <strong>the</strong>n combusted at high<br />

temperatures (1300ºC) and efficiencies, from which heat recovery occurs <strong>to</strong> produce heat or power<br />

output. Applying this technology <strong>to</strong> MSW means that <strong>the</strong> waste can be burnt in much better combustion<br />

conditions, reducing <strong>the</strong> potential for dioxin production, NOx and <strong>the</strong> dry slag produced is vitrified inert,<br />

carbon and dioxin free.<br />

Typically, a 100,000tpa R21 plant treating MSW with a calorific value of 9.5MJ/kg will produce 8MW gross<br />

electrical output per <strong>to</strong>nne of MSW 299 . Some of this electrical energy is used in house <strong>to</strong> drive <strong>the</strong> process<br />

reducing this figure <strong>to</strong> 5.1MW net electrical output per <strong>to</strong>nne MSW. Table 83 cites some of <strong>the</strong><br />

commercially operating facilities <strong>by</strong> Mitsui Babcock Energy Ltd in Japan. 299 The focus in Japan is<br />

currently very much on waste disposal and recovery of material ra<strong>the</strong>r than energy.<br />

.<br />

Table 83 Examples of commercially operating R21 facilities <strong>by</strong> Mitsui Babcock Energy<br />

Location Capacity (<strong>to</strong>nnes/day)<br />

Aichi/ Toyohashi City 220tpd over 2 trains<br />

Hokkaido / Ebetsu City 140tpd over 2 trains<br />

Fukuoka / Koga Seibu<br />

Regional Cooperative 260tpd over 2 trains<br />

298<br />

The Avonmouth Renewable Energy Plant, Defra Factsheet, http://www.defra.gov.uk/environment/waste/wip/newtech/demprogramme/pdf/Avonmouth.pdf<br />

299<br />

Mitsui Babcock Energy Limited Submission <strong>to</strong> Greater London Authority City Solutions Stakeholders On Municipal Waste Management, 2003,<br />

http://www.london.gov.uk/mayor/environment/waste/wasteconfdocs/Mitsui.pdf<br />

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Figure 22 A schematic of <strong>the</strong> Toyohashi R21 system<br />

Coke-Oven<br />

A process developed <strong>by</strong> Nippon Steel converts waste plastic in<strong>to</strong> energy, <strong>the</strong> “Coke-Oven from Waste<br />

Plastics <strong>to</strong> Chemical Raw Materials Method”. This method uses a chemical recycling process <strong>to</strong> recover<br />

coke, tar, light oil and gas from general wastes plastics mixed in coal <strong>by</strong> carbonisation of coke ovens<br />

without deteriorating <strong>the</strong> quality of coke. The yield from this process is approximately 20% of coke, 40%<br />

tar and light oil, and 40% gases. The recovered coke is used <strong>to</strong> reduce <strong>the</strong> iron ore in a blast furnace, <strong>the</strong><br />

tar and light oil as raw material for making plastic and <strong>the</strong> gas in a power plant. A number of such<br />

facilities exist in Japan, and shown in Table 84. Nippon Steel have recently filed a patent for a process<br />

which would give a product with greater utility value. 300<br />

Table 84 List of Coke-Oven from Waste Plastics <strong>to</strong> Chemical Raw Materials Method facilities<br />

Year Capacity<br />

City<br />

<strong>to</strong>nnes p.a.<br />

Nagoya 2000 40,000<br />

Kimitsu 2000 40,000<br />

Muroran 2002 20,000<br />

Yawata 2002 20,000<br />

300 Method and Apparatus for Thermal Decomposition of Waste Plastics, JP2008266452 (A), Nippon Steel Corporation, 06.11.2008.


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As is demonstrated <strong>by</strong> <strong>the</strong> above examples, in terms of <strong>the</strong>rmal treatment of waste Japan, has a wellestablished<br />

system in place. Now <strong>the</strong> agenda has begun <strong>to</strong> shift <strong>to</strong>wards <strong>the</strong> generation of energy as well<br />

as waste minimisation, Japan is one of <strong>the</strong> leading countries in terms of technology development and has<br />

<strong>the</strong> largest number of plants in operation that use <strong>the</strong>rmal conversion techniques <strong>to</strong> treat waste and<br />

recover energy.<br />

10.3 Conclusions<br />

From this review <strong>the</strong> following conclusions can be drawn;<br />

• Combustion, gasification and pyrolysis all use heat <strong>to</strong> break down <strong>the</strong> structure of <strong>the</strong> feeds<strong>to</strong>ck<br />

so that <strong>the</strong> chemical energy can be released ei<strong>the</strong>r as heat or a fuel product. The conditions in<br />

<strong>the</strong> reac<strong>to</strong>r determine <strong>the</strong> products.<br />

• Gasification technologies are being developed but often encounter severe technical difficulties<br />

when attempting <strong>the</strong> step of using <strong>the</strong> gas for power generation in an engine or gas turbine.<br />

• The robust approach of firing <strong>the</strong> gas in a boiler is proving reliable and a worthwhile innovation.<br />

These units can be produced in smaller sizes than conventional incineration and can be matched<br />

<strong>to</strong> heat loads in CHP and process heating applications <strong>to</strong> give potentially <strong>the</strong> best GHG<br />

abatement potential.<br />

• Gasification as a pre-treatment is likely <strong>to</strong> become more popular in cofiring as genera<strong>to</strong>rs seek <strong>to</strong><br />

increase <strong>the</strong> proportion of biomass in coal fired utility boilers.<br />

• There are few commercial pyrolysis plant operating on waste.<br />

• The technologies available for conversion of waste <strong>to</strong> heat and power are more widesp<strong>read</strong> than<br />

those for conversion <strong>to</strong> transport fuels, although work is ongoing on advanced conversion for<br />

liquid biofuels.<br />

• The use of gasification at very large scale for <strong>the</strong> production of transport fuels or pipeline<br />

methane is attracting increasing attention and is potentially an efficient use of resources.<br />

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11 Potential GHG Reductions<br />

Wastes arisings in <strong>the</strong> UK represent a potential resource and feeds<strong>to</strong>ck available <strong>to</strong> be converted in<strong>to</strong><br />

products for fur<strong>the</strong>r use. Assessing <strong>the</strong> most environmentally friendly disposal option for a particular<br />

waste can be challenging as <strong>the</strong>re are often a range of disposal options available and limited data on<br />

which <strong>to</strong> base assumptions of potential environmental costs and benefits.<br />

The key advantage of utilising waste materials for <strong>the</strong> generation of energy or transport fuels is that <strong>the</strong>y<br />

displace <strong>the</strong> use of fossil fuels and divert material that would o<strong>the</strong>rwise likely be disposed of <strong>to</strong> landfill.<br />

The quantification of <strong>the</strong> environmental costs and benefits is required <strong>to</strong> ensure <strong>the</strong> most appropriate<br />

solutions are developed. Recent work performed <strong>by</strong> AEA and North Energy for <strong>the</strong> EU Commission, DG<br />

Environment (awaiting publication) has identified that ‘waste-based bio-energy pathways offer <strong>the</strong> highest<br />

GHG emissions savings’. 301 This is due <strong>to</strong> <strong>the</strong> absence of production emissions for <strong>the</strong> material, and <strong>the</strong><br />

displaced fossil fuels.<br />

Below, two scenarios of converting a waste material <strong>to</strong> energy or a transport fuel, and <strong>the</strong> GHG savings<br />

such conversions would achieve, have been explored:<br />

• Converting source separated food waste, through anaerobic digestion, <strong>to</strong> a digestate and a<br />

biogas, and subsequently converting this biogas <strong>to</strong> CHP, electricity or alternatively a transport<br />

fuel.<br />

• Converting waste wood, through combustion, <strong>to</strong> electricity.<br />

These scenarios were selected <strong>to</strong> complement our identification of <strong>the</strong>se feeds<strong>to</strong>cks in Section 5 as likely<br />

<strong>to</strong> make a substantial contribution <strong>to</strong> renewable energy from wastes in <strong>the</strong> future. They also illustrate <strong>the</strong><br />

insights that can be gained through this type of analysis as <strong>the</strong>y cover an extensive life cycle extending in<br />

<strong>to</strong> feeds<strong>to</strong>ck supply and alternative uses.<br />

Both scenarios are been explored through <strong>the</strong> use of BEAT.<br />

Box 4: Biomass Environmental Assessment Tool (BEAT)<br />

BEAT was originally developed for <strong>the</strong> UK Department for Environment, Food and Rural Affairs<br />

(Defra) and <strong>the</strong> UK Environment Agency (EA). Hence, <strong>the</strong> nature of <strong>the</strong> technologies, performance<br />

characteristics and related assumptions are based on UK circumstances.<br />

It is designed <strong>to</strong> provide a means of assessing biomass schemes <strong>by</strong>:<br />

1. Providing a comparison of GHG emissions from <strong>the</strong> proposed plant and fossil fuel based plant;<br />

2. Providing information on key potential environmental impacts;<br />

3. Identifying potential options for mitigating environmental impacts;<br />

4. Providing an estimate of production costs and of support mechanisms.<br />

While <strong>the</strong> <strong>to</strong>ol can consider all stages of <strong>the</strong> fuel chain, modification of <strong>the</strong> analysis is <strong>read</strong>ily<br />

achievable through altering <strong>the</strong> system boundaries and <strong>the</strong> reference pathway.<br />

BEAT was launched on 13th November 2008, when <strong>the</strong> <strong>to</strong>ol/dataset were also made publicly available.<br />

Beat is available from <strong>the</strong> Biomass Energy Centre www.biomassenergycentre.org.uk.<br />

301 Implementation of <strong>the</strong> EU Biomass Action Plan and <strong>the</strong> Biofuel Strategy: Comparing GHG emission reduction performance of different bio-energy<br />

applications on a life cycle basis, AEA and North Energy,


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Some of <strong>the</strong> key features of <strong>the</strong> BEAT systems and <strong>the</strong> criteria that have been used here are:<br />

• System boundary: In this work <strong>the</strong> systems begin at <strong>the</strong> point <strong>the</strong> waste is available for use as a<br />

resource, taking no consideration of <strong>the</strong> environmental impacts of creating <strong>the</strong> waste. Once use<br />

of <strong>the</strong> waste as a feeds<strong>to</strong>ck commences all subsequent stages are incorporated, e.g. emissions<br />

from processing <strong>the</strong> waste, manufacture of machinery and ash disposal, <strong>to</strong> cite a few stages.<br />

• GHG Emissions: Emissions of <strong>the</strong> three main GHGs, carbon dioxide (CO2), methane (CH4) and<br />

nitrous oxide (N2O) are included. While carbon dioxide and, <strong>to</strong> a lesser extent, methane<br />

emissions are widely publicised, sources of nitrogen giving rise <strong>to</strong> <strong>the</strong> emission of nitrous oxide<br />

(N2O) from <strong>the</strong> soil is a less well known effect. A complex series of reactions and processes<br />

transform some of <strong>the</strong> nitrogen present in<strong>to</strong> N2O, potentially a critical issue as <strong>the</strong> global warming<br />

potential of N2O is nearly 300 times that of CO2. Individual GHG emissions are converted in<strong>to</strong><br />

equivalent CO2 using quoted values of Global Warming Potentials (GWPs).<br />

• CHP: In all cases emissions savings have been derived assuming <strong>the</strong> displacement of<br />

compressed natural gas, or <strong>the</strong> displacement of grid electricity.<br />

• Reference system: Reference systems are used here <strong>to</strong> address <strong>the</strong> alternative fate of a waste<br />

product. The disposal of a waste product will be avoided if it is used as a biomass feeds<strong>to</strong>ck for<br />

energy production. The GHG emissions that would have arisen from disposal are taken in<strong>to</strong><br />

account <strong>by</strong> deducting from <strong>the</strong> <strong>to</strong>tal GHG emissions of <strong>the</strong> pathway.<br />

• Fossil Fuel Displacement: Assumptions about <strong>the</strong> fossil fuel displaced (e.g. coal, oil, or gas) and<br />

<strong>the</strong> efficiency of <strong>the</strong> conversion technology for heat and electricity production can make a<br />

significant difference <strong>to</strong> <strong>the</strong> savings calculated.<br />

Using BEAT <strong>to</strong> follow <strong>the</strong> two waste disposal scenarios outlined below allow establishment of <strong>the</strong><br />

potential GHG reductions that could be achieved were <strong>the</strong> alternative disposal route <strong>to</strong> be pursued and<br />

<strong>the</strong> final products <strong>full</strong>y utilised.<br />

The results have been presented in terms of <strong>the</strong> kilograms of GHG saved per <strong>to</strong>nne of waste, as waste<br />

utilisation is <strong>the</strong> primary aim, with energy generation <strong>the</strong> secondary aim.<br />

11.1 Scenario 1: Food Waste<br />

Domestic food waste can be collected separately as part of <strong>the</strong> MSW disposal route. This waste<br />

represents a resource that can be widely available throughout <strong>the</strong> UK, although collection and transport<br />

are likely <strong>to</strong> be more efficient in urban areas. It is estimated that <strong>the</strong>re is potentially 5 million <strong>to</strong>nnes of<br />

MSW food waste each year, as well as nearly 7 million <strong>to</strong>nnes of C&I food waste (for England, Wales and<br />

Scotland), although it is unlikely all would be available for collection.<br />

The majority of this waste stream currently goes <strong>to</strong> landfill, often with energy recovery through landfill gas.<br />

This situation is rapidly changing with <strong>the</strong> requirement of <strong>the</strong> Landfill Directive that levels of biodegradable<br />

municipal solid waste (MSW) sent <strong>to</strong> landfill must be reduced <strong>to</strong> 75% <strong>by</strong> 2010, <strong>by</strong> 50% 2013 and <strong>by</strong> 35%<br />

<strong>by</strong> 2020 of 1995 levels. The alternative disposal options available are <strong>to</strong> compost or anaerobically digest<br />

<strong>the</strong> waste.<br />

Food waste treated at a compost site will produce a soil conditioner material. The composting process<br />

will be required <strong>to</strong> be carried out in a sealed container as <strong>the</strong> material may contain meat or meat<br />

products.<br />

Food waste treated at an AD site will produce an organic digestate output, which can be used as a soil<br />

conditioner. It has been assumed that a compost soil conditioner and a digestate soil conditioner,<br />

although having different physical forms, have <strong>the</strong> same value as a soil conditioner. In addition biogas<br />

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will be produced which, depending on <strong>the</strong> properties of <strong>the</strong> input material, can be expected <strong>to</strong> contain<br />

approximately 40% carbon dioxide and 60% methane. The biogas can be upgraded, cleaned,<br />

compressed and ultimately converted in<strong>to</strong> a transport fuel.<br />

MSW Food<br />

Waste<br />

Biodegradation<br />

Composting<br />

Anaerobic<br />

Digestion<br />

Landfill<br />

With landfill gas<br />

Compost<br />

Digestate<br />

Biogas<br />

Cleaning and<br />

Compression<br />

Figure 23 Disposal options for food waste<br />

Transport<br />

Gas<br />

While disposal <strong>to</strong> landfill is <strong>the</strong> current most likely route, composting is likely <strong>to</strong> become <strong>the</strong> norm in <strong>the</strong><br />

near future. Therefore <strong>the</strong> utilisation of waste food has been explored predominately with <strong>the</strong> reference<br />

system set as in vessel compositing:<br />

1. The GHG savings an AD disposal route would generate, with <strong>the</strong> biogas produced used for:<br />

a. heat and electricity generation,<br />

b. electricity generation,<br />

c. <strong>the</strong> biogas used for vehicle transport, with additional cleaning and compression stages.<br />

In addition a comparison reference system of disposal <strong>to</strong> landfill has been run:<br />

2. The GHG savings an AD disposal route would generate, with landfill disposal used as <strong>the</strong><br />

reference system with <strong>the</strong> biogas produced used for:<br />

a. electricity generation.


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Table 85 Comparing AD disposal of food waste against in vessel composting<br />

End Use<br />

1a<br />

GHG savings<br />

kg CO2eq /<br />

<strong>to</strong>nne biomass<br />

• Centralised AD for CHP using 90,000<br />

<strong>to</strong>nnes food waste per annum.<br />

104<br />

• 1.7MWe and 4MWth exported.<br />

• 75% efficiency at 55% load.<br />

1b<br />

• Centralised AD for electricity using 90,000<br />

<strong>to</strong>nnes food waste per annum.<br />

• 2.8MWe exported<br />

• 25% efficiency at 70% load<br />

1c<br />

• Centralised AD for biomethane production<br />

from 90,000 <strong>to</strong>nnes of food waste per<br />

annum, <strong>to</strong> be used for vehicle transport.<br />

• 28,000MWth per annum biomethane<br />

produced.<br />

The centralised AD systems generating energy, one generating CHP, <strong>the</strong> o<strong>the</strong>r only electricity, can be<br />

considered as economically feasible where gate fees can be charged. The conversion of <strong>the</strong> biogas in<strong>to</strong><br />

a transport gas is not commercial currently in <strong>the</strong> UK.<br />

The benefits of composting food waste or anaerobically digesting it are broadly similar. The additional<br />

significant benefit of AD systems is <strong>the</strong> use of <strong>the</strong> biogas <strong>to</strong> displace fossil fuel use. Although <strong>the</strong>re is<br />

some variation between <strong>the</strong> above scenarios, all three represent significant GHG savings versus <strong>the</strong><br />

composting of <strong>the</strong> waste. The CHP scenario assumes 100% utilisation of <strong>the</strong> heat produced, a utilisation<br />

level that may be challenging <strong>to</strong> meet, and correspondingly <strong>the</strong> real-world GHG savings are more likely <strong>to</strong><br />

be comparable with those for electricity generation or transport fuel generation.<br />

Table 86 Comparing AD disposal of food waste against landfill disposal, with landfill gas recovery<br />

End Use GHG savings*<br />

(Kg CO2eq / T)<br />

2a<br />

• Centralised AD for electricity using 90,000 <strong>to</strong>nnes<br />

food waste per annum.<br />

219<br />

• 10MWe exported<br />

• 25% efficiency at 70% load<br />

Significant GHG emissions still occur through using AD, such as methane leakage from <strong>the</strong> system and<br />

N2O generation from <strong>the</strong> sp<strong>read</strong>ing and incorporation of <strong>the</strong> digestate in<strong>to</strong> soil. However, even taking<br />

such effects in<strong>to</strong> account, it can be concluded that using AD <strong>to</strong> dispose of food waste, with electricity<br />

generation from <strong>the</strong> biogas, large GHG savings are generated, versus disposal <strong>to</strong> land fill.<br />

Where use of AD disposal routes is compared <strong>to</strong> in-vessel composting, significant GHG savings are also<br />

achieved, whe<strong>the</strong>r <strong>the</strong> biogas is used for CHP, electricity generation or as a transport fuel. The most<br />

78<br />

71<br />

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significant saving is if <strong>the</strong> biogas is used for CHP and highly efficient use of <strong>the</strong> heat generated is<br />

achieved.<br />

11.2 Scenario 2: Wood Waste<br />

Wood waste is taken here <strong>to</strong> be wood that is contaminated, ei<strong>the</strong>r impregnated with preservatives, or<br />

coated with paints and varnished. Disposal <strong>the</strong>refore requires WID compliant facilities, and currently only<br />

<strong>the</strong> largest of facilities have appropriate emissions cleaning facilities. While a considerable quantity of<br />

such material is estimated <strong>to</strong> be disposed of each year, <strong>the</strong>re is little good quality data for this waste<br />

stream. Estimations from WRAP put <strong>the</strong> volume of wood waste at 1,065,000 <strong>to</strong>nnes from MSW, 602,000<br />

<strong>to</strong>nnes from waste furniture, 4,400,000 <strong>to</strong>nnes from C&D waste (5,040,000 if include reclaimed wood),<br />

and 4,481,000 <strong>to</strong>nnes from C&I waste. This would potentially offer 10,548,000 <strong>to</strong>nnes of wood waste a<br />

year.<br />

The options available for <strong>the</strong> disposal of wood waste are for it <strong>to</strong> be sent <strong>to</strong> landfill or for it <strong>to</strong> be<br />

segregated and used as a feeds<strong>to</strong>ck for combustion, generating heat, CHP or electricity. An alternative<br />

possibility is for a conversion process <strong>to</strong> be used, such as gasification followed <strong>by</strong> Fischer Tropsch <strong>to</strong><br />

generate a transport fuel. This however hasn’t been modelled as we have been unable <strong>to</strong> identify<br />

sufficient data on using wood waste as a feeds<strong>to</strong>ck for this process.<br />

Waste Wood<br />

Combustion<br />

Landfill<br />

With landfill gas<br />

Heat, CHP<br />

or Electricity<br />

Figure 24 Disposal options for waste wood<br />

It is assumed that most wood waste is disposed of <strong>to</strong> landfill with energy recovery. Such a scenario has<br />

not been taken as <strong>the</strong> reference system for this work as <strong>the</strong> intention here is <strong>to</strong> compare <strong>the</strong> different end<br />

uses of waste wood, and comparison <strong>to</strong> landfilling can generates large negatives that do not allow<br />

accurate comparison. In <strong>the</strong> following situations <strong>the</strong> GHG savings come from <strong>the</strong> displaced fossil fuel, in<br />

each case natural gas, so once again giving a conservative estimate of <strong>the</strong> savings generated.<br />

Two different scenarios considering <strong>the</strong> GHG saving that could be achieved from using waste wood as a<br />

feeds<strong>to</strong>ck for energy generation.<br />

1. Industrial or commercial building heating. This system is al<strong>read</strong>y economic, but still has<br />

challenges <strong>to</strong> face including WID compliant facilities, fuel s<strong>to</strong>rage and ash disposal.<br />

2. Combustion in a medium scale plant – <strong>the</strong> practical limit for waste levels generated within an<br />

RDA geographical region. Such a system would be economic with <strong>the</strong> currently available<br />

subsidy i.e. <strong>the</strong> availability of 1.5 ROC.<br />

Both systems have been considered in terms of <strong>the</strong> displacement of natural gas as <strong>the</strong> fossil fuel<br />

equivalent and are estimated <strong>to</strong> would produce <strong>the</strong> following GHG savings:


Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Wastes and Energy<br />

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Table 87 Combustion of wood waste and <strong>the</strong> savings generated from avoided fossil fuel consumption<br />

End Use GHG savings<br />

(Kg CO2eq / <strong>to</strong>nne of<br />

biomass)<br />

• Industrial or Commercial building heating<br />

• 500kW boiler using wood chips<br />

1,040<br />

• Operating at 33% load<br />

• Medium combustion plant<br />

• 50MWe exported<br />

450<br />

• 85% load.<br />

Significant GHG savings would be achieved were wood waste <strong>to</strong> be used as a fuel source for<br />

combustion, ra<strong>the</strong>r than disposal <strong>to</strong> landfill.<br />

11.3 O<strong>the</strong>r, recent GHG life cycle analyses<br />

Recent work <strong>by</strong> <strong>the</strong> Environment Agency has analysed a wide range of biomass energy cycles using <strong>the</strong><br />

BEAT <strong>to</strong>ol. Such cycles take in <strong>to</strong> account <strong>the</strong> fate of <strong>by</strong>-products and <strong>the</strong> production of <strong>the</strong> fuel. The<br />

main findings of this work are that<br />

• Heat applications are <strong>the</strong> most beneficial in terms of GHG abatement followed <strong>by</strong> CHP where <strong>the</strong><br />

heat load is high.<br />

• Transport fuel production <strong>by</strong> means of gasification is mid range.<br />

• Electricity production comes lower in <strong>the</strong> hierarchy as do biological transport fuel processes and<br />

low heat load CHP.<br />

What is interesting from this work is that it is <strong>the</strong> resource use efficiency <strong>to</strong> energy that is <strong>the</strong> determining<br />

fac<strong>to</strong>r, so that heat will always score highly because it converts over 90% of <strong>the</strong> energy of <strong>the</strong> feeds<strong>to</strong>ck<br />

in<strong>to</strong> usable heat. The performance of CHP is very dependent on <strong>the</strong> heat load; industrial process heat<br />

loads score well but minimal application of district heat scores badly.<br />

Given <strong>the</strong> high resource use efficiency gasification and methanation should be very beneficial if <strong>the</strong> high<br />

grade heat from <strong>the</strong> exo<strong>the</strong>rmal reaction is <strong>full</strong>y used, however <strong>the</strong>re is no data on <strong>the</strong>se systems at<br />

present.<br />

171


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12 Recommendations and NNFCC’s role<br />

Challenges, issues and <strong>the</strong> role of NNFCC<br />

Throughout this <strong>report</strong> we have identified areas of uncertainty, and specific challenges that need work if<br />

<strong>the</strong> <strong>full</strong> potential of energy from waste is <strong>to</strong> be realised. These are set out in <strong>the</strong> table below. Most of<br />

<strong>the</strong>se are concerned with building business confidence in <strong>the</strong> links between each of <strong>the</strong> technology steps.<br />

Not all of this work will come under NNFCC’s remit but a significant amount is concerned with<br />

coordination of stakeholders and <strong>the</strong> provision of information <strong>to</strong> <strong>the</strong> market.<br />

Those <strong>to</strong>pics we feel are most appropriate for NNFCC initiatives are as follows:<br />

• Improve quality of policy and investment decision making <strong>by</strong> developing an understanding of <strong>the</strong><br />

fit between SRF properties and energy production technologies. What properties does each of<br />

<strong>the</strong> technologies require?<br />

• There is a wide difference in <strong>the</strong> benefits brought <strong>by</strong> various waste <strong>to</strong> energy chains and it is<br />

important that policy support those that contribute <strong>the</strong> most. NNFCC could add value <strong>by</strong><br />

developing an evidence base for <strong>the</strong> design and implementation of policy and a hierarchy of uses<br />

for each class of resource based on environmental and social benefits including life cycle GHG<br />

impact.<br />

• To maximise <strong>the</strong> benefits of using waste for energy we will need <strong>to</strong> change current practices<br />

across a wide range of stakeholders. NNFCC could add value <strong>by</strong> developing an understanding of<br />

<strong>the</strong> relative timeframes of structural changes and technology developments necessary <strong>to</strong><br />

maximise implementation.<br />

• Develop a better understanding of <strong>the</strong> impacts of increased energy usage on alternative and<br />

existing markets for straw and o<strong>the</strong>r residues.<br />

• NNFCC could consider <strong>the</strong> logistics of moving dispersed low density feeds<strong>to</strong>cks around <strong>the</strong> UK,<br />

taking a role <strong>to</strong> assess options for transport modes and evaluate <strong>the</strong> optimal size of plants for <strong>the</strong><br />

various feeds<strong>to</strong>cks.<br />

• Municipal and solid waste is being managed using more sustainable technologies. There is<br />

interest in developing <strong>the</strong>se technologies on one site, so that recycling, separation technologies<br />

or mechanical and biological treatment and anaerobic digestion is all integrated. NNFCC could<br />

examine <strong>the</strong> potential energy benefits in such trends and <strong>the</strong> impact <strong>the</strong>y may have on energy<br />

recovery from waste in general.


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Table 88 Recommendations for NNFCC’s role<br />

Challenge Purpose NNFCC<br />

1 Improve evidence base<br />

for policy and investment<br />

decision making<br />

2 Facilitate commercial<br />

transactions and develop<br />

SRF as a traded<br />

commodity.<br />

3 Improve quality of policy<br />

and investment decision<br />

making<br />

4<br />

5<br />

Provide an evidence base<br />

for <strong>the</strong> design and<br />

implementation of policy<br />

Build market confidence,<br />

enhance UK market<br />

share<br />

Quantifying arisings of C & I wastes. Reducing<br />

uncertainty in quantities, properties and composition<br />

of commercial and industrial waste streams. Data is<br />

very sparse compared with <strong>the</strong> municipal sec<strong>to</strong>r.<br />

Development of analysis methods in particular <strong>the</strong><br />

determination of <strong>the</strong> biogenic proportion of SRF<br />

Support <strong>the</strong> implementation of CEN standards for<br />

SRF<br />

Develop an understanding of <strong>the</strong> fit between SRF<br />

properties and energy production technologies.<br />

What properties does each of <strong>the</strong> technologies<br />

<br />

require?<br />

Develop a hierarchy of uses for each class of<br />

resource based on environmental and social <br />

benefits<br />

Develop an understanding of <strong>the</strong> relative timeframes<br />

of structural changes and technology developments <br />

necessary <strong>to</strong> maximise implementation.<br />

Develop a better understanding of <strong>the</strong> impacts of<br />

increased energy usage on alternative and existing <br />

markets for straw and o<strong>the</strong>r residues.<br />

Identify technology areas needing demonstration. <br />

Industrial pre qualification round for demonstration<br />

Implement a portfolio of shared cost technology<br />

demonstrations<br />

Lead<br />

Collaborate<br />

173<br />

O<strong>the</strong>rs lead<br />

<br />

<br />

<br />

<br />

<br />

1 – 2<br />

years<br />

2 – 5<br />

years<br />

5 – 10<br />

years<br />

Beyond<br />

10<br />

years


Appendices<br />

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Appendix 1: Fur<strong>the</strong>r information on Waste Arisings<br />

Appendix 2: Waste Legislation<br />

Appendix 3: MBT Methods


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Appendix 1<br />

Fur<strong>the</strong>r information on Waste Arisings<br />

This information has been provided so that methodologies for deriving <strong>the</strong> data can be followed, and reapplied, should information be required on a different<br />

scale.<br />

A1.1 Agricultural Residue Arisings<br />

The following tables give more detail regarding <strong>to</strong> potential Agricultural residue arisings and <strong>the</strong>ir energy content.<br />

Table 89 Lives<strong>to</strong>ck numbers for <strong>the</strong> UK, on a regional basis.<br />

East Midlands<br />

East of England<br />

North East<br />

North West<br />

South East inc.<br />

London<br />

South West<br />

West Midlands<br />

Yorkshire and<br />

Humber<br />

England – Total<br />

Nor<strong>the</strong>rn<br />

Ireland<br />

Dairy α<br />

O<strong>the</strong>r<br />

cattle β<br />

Cattle Pigs Poultry<br />

Calves γ Total Dry Sow δ<br />

Sows<br />

plus<br />

litter) ε<br />

Fattening<br />

pig (20-<br />

130kg) ζ<br />

175<br />

Weaners<br />

(


Scotland<br />

Wales<br />

UK – Total<br />

176<br />

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170,820 1,176,390 549,970 1,897,180 41,420 6,230 285,210 123,900 456,760 2,920,240 1,586,610 8,308,280<br />

280,968 735,732 306,088 1,322,788 3,061 643 15,343 6,119 25,166 1,532,725 273,756 5,836,436<br />

2,242,212 5,059,471 3,138,339 10,440,022 459,711 75,549 3,043,345 1,249,063 4,827,668 34,270,836 9,771,642 1.5 x 10 8<br />

α Dairy cattle are dairy females over 2 years.<br />

β O<strong>the</strong>r cattle includes beef cattle, all males older than 1 year, and dairy females between 1-2 years<br />

γ Calves include all cattle younger than 1 year.<br />

δ Dry sows are pregnant pigs: sows in pig and gilts in pig, as well as boars for service and gilts.<br />

ε Sows plus litter are classified as ‘o<strong>the</strong>r sows’ in <strong>the</strong> census tables.<br />

ζ Fattening pig includes barren sows for fattening as well as all fattening pigs between 20 – 130 kg.<br />

Table 90 Volatile Solids of Collectable lives<strong>to</strong>ck manure arisings, for <strong>the</strong> UK, on a regional basis.<br />

Amounts are kilograms per day.<br />

East Midlands<br />

East of England<br />

North East<br />

North West<br />

South East inc.<br />

London<br />

South West<br />

West Midlands<br />

Yorkshire and<br />

Humber<br />

England – Total<br />

Nor<strong>the</strong>rn<br />

Ireland<br />

Scotland<br />

Dairy α<br />

O<strong>the</strong>r<br />

cattle β<br />

η All pigs under 20kg.<br />

θ Total layers includes growing pullets and laying birds.<br />

ι Includes layer breeders, broiler breeders, cocks and cockerels.<br />

κ Total fowls excludes all o<strong>the</strong>r types of poultry (turkeys, ducks, geese), as <strong>the</strong> numbers are considerable<br />

smaller, and a much greater proportion are free range.<br />

Cattle Pigs Fowls<br />

Calves γ Total Dry Sow δ<br />

Sows<br />

plus<br />

litter) ε<br />

Fattening<br />

pig (20-<br />

130kg) ζ<br />

Weaners<br />

(


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Wales<br />

380,743 996,999 0 1,377,742 675 304 2,233 436 3,648 81,234<br />

UK – Total<br />

3,038,448 6,856,150 0 9,894,598 101,366 35,697 442,898 89,033 668,994 1,816,354<br />

Table 91 Bio Methane Potential of collectable lives<strong>to</strong>ck manure arisings, for <strong>the</strong> UK, on a regional basis.<br />

Amounts are cubic meters (m 3 ) of methane per kilogram of Volatile Solids (VS).<br />

Cattle Pigs Fowls<br />

Dairy α O<strong>the</strong>r<br />

cattle β Calves γ Total Dry Sow δ<br />

Sows<br />

plus<br />

litter) ε<br />

Fattening<br />

pig (20-<br />

130kg) ζ<br />

Weaners<br />

(


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Table 92 Crop area potentially generating straw, <strong>by</strong> crop type and region of <strong>the</strong> UK 302<br />

Year<br />

Region Crop area<br />

(‘000 ha)<br />

2003 2004 2005 2006 2007 2008<br />

East Midlands Wheat 353 386 348 347 343<br />

O<strong>the</strong>r Cereals 104 90 82 82 84<br />

Oilseed rape 101 106 117 114 139<br />

East of England Wheat 481 513 486 472 470<br />

O<strong>the</strong>r Cereals 177 161 146 143 145<br />

Oilseed rape 94 91 101 104 130<br />

North East Wheat 66 71 68 65 66<br />

O<strong>the</strong>r Cereals 48 44 42 42 43<br />

Oilseed rape 22 25 25 23 27<br />

North West Wheat 28 36 31 31 30<br />

O<strong>the</strong>r Cereals 44 45 42 41 42<br />

Oilseed rape 4 4 4 4 4<br />

South East and Wheat 241 251 241 237 229<br />

London O<strong>the</strong>r Cereals 99 89 79 81 86<br />

Oilseed rape 75 81 83 79 92<br />

South West Wheat 174 191 180 176 172<br />

O<strong>the</strong>r Cereals 139 130 118 119 124<br />

Oilseed rape 41 48 47 45 52<br />

West Midlands Wheat 150 167 157 155 153<br />

O<strong>the</strong>r Cereals 80 70 64 65 69<br />

Oilseed rape 33 36 38 34 43<br />

Yorkshire and Wheat 233 252 237 227 227<br />

Humber O<strong>the</strong>r Cereals 126 116 108 107 111<br />

Oilseed rape 54 65 66 61 76<br />

England -Total 10379 10728 10182 9977 10343<br />

Scotland Wheat 88 101 96 100 103 114<br />

O<strong>the</strong>r Cereals 321 314 295 274. 279 320<br />

Oilseed rape 35 39 36 34 36 34<br />

Wales Wheat 15 15 15 16 -<br />

O<strong>the</strong>r Cereals 24 25 22 19 -<br />

Oilseed rape 3 3 3 3 -<br />

Nor<strong>the</strong>rn Wheat 7 9 8 9 9 12<br />

Ireland O<strong>the</strong>r Cereals 28 27 26 23 23 -<br />

Oilseed rape 0.1 0.3 0.3 0.5 0.4 -<br />

UK – Total 12197 12896 11935 11648<br />

302 Data collated from Defra Farm Survey 2008, Welsh Agricultural Statistics 2007,<br />

http://wales.gov.uk/docrepos/40368/4038231/statistics/agriculture/agric2008/was07/was07ch1.xls?lang=en , The Agricultural Census of Nor<strong>the</strong>rn<br />

Ireland and Statistical tables and graphs showing <strong>the</strong> final results of <strong>the</strong> 2008 June Agricultural and Horticultural Census, Scotland,<br />

http://www.scotland.gov.uk/News/Releases/2009/01/14164908.


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Table 93 Nutrient values of straw, taken from <strong>the</strong> ADAS Report for NNFCC. 303<br />

Nutrient value /t £/kg* Value £/t<br />

Wheat<br />

N - 5.0 kg 1.13 5.65<br />

P2O5 - 1.3 kg 1.45 1.89<br />

K2O - 9.3 kg 1.00 9.30<br />

Total 16.84<br />

Barley<br />

N - 6.0 kg 1.13 6.78<br />

P2O5 - 1.5 kg 1.45 2.18<br />

K2O – 12.6 kg 1.00 12.60<br />

Total 21.56<br />

Oilseed Rape<br />

N - 7.7 kg 1.13 8.70<br />

P2O5 - 2.2 kg 1.45 3.19<br />

K2O – 11.5 kg 1.00 11.50<br />

Total 23.39<br />

Table 94 Total Fowl Numbers raised on bedding, <strong>by</strong> region for <strong>the</strong> UK<br />

East Midlands<br />

East of England<br />

North East<br />

North West<br />

South East inc.<br />

London<br />

South West<br />

West Midlands<br />

Yorkshire and<br />

Humber<br />

England –<br />

Total<br />

Nor<strong>the</strong>rn<br />

Ireland<br />

Scotland<br />

Wales<br />

UK – Total<br />

Total Fowls<br />

Total<br />

Layers<br />

Fowls raised<br />

on bedding<br />

24,177,981 6,816,531 17,361,450<br />

25,312,303 2,458,942 22,853,361<br />

2,428,461 295,369 2,133,092<br />

8,262,834 2,453,187 5,809,647<br />

9,866,970 4,009,313 5,857,657<br />

18,315,773 5,952,707 12,363,066<br />

16,602,106 2,914,044 13,688,062<br />

14,408,052 2,519,278 11,888,774<br />

119,374,480 27,419,371 91,955,109<br />

16,321,500 2,398,500 13,923,000<br />

8,308,280 2,920,240 5,388,040<br />

5,836,436 1,532,725 4,303,711<br />

1.5 x 10 8<br />

34,270,836 115,729,164<br />

303 Addressing <strong>the</strong> land use issues for non-food crops in response <strong>to</strong> increasing fuel and energy generation opportunities, ADAS for NNFCC, 2008,<br />

http://www.nnfcc.co.uk/metadot/index.pl?id=8253;isa=DBRow;op=show;dbview_id=2539<br />

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Table 95 Estimated Poultry Litter output <strong>by</strong> Region<br />

180<br />

East Midlands<br />

East of England<br />

North East<br />

North West<br />

South East inc.<br />

London<br />

South West<br />

West Midlands<br />

Yorkshire and<br />

Humber<br />

England – Total<br />

Nor<strong>the</strong>rn<br />

Ireland<br />

Scotland<br />

Wales<br />

UK – Total<br />

Fowls raised on<br />

bedding<br />

Table 96 Estimated Poultry Litter output <strong>by</strong> Region<br />

East Midlands<br />

East of England<br />

North East<br />

North West<br />

South East inc.<br />

London<br />

South West<br />

West Midlands<br />

Yorkshire and<br />

Humber<br />

England – Total<br />

Nor<strong>the</strong>rn<br />

Ireland<br />

Scotland<br />

Wales<br />

UK – Total<br />

Litter output<br />

(‘000 <strong>to</strong>nnes)<br />

Energy Content<br />

(GJ)<br />

17,361,450 625 5,625,110<br />

22,853,361 823 7,404,489<br />

2,133,092 77 691,122<br />

5,809,647 209 1,882,326<br />

5,857,657 211 1,897,881<br />

12,363,066 445 4,005,633<br />

13,688,062 493 4,434,932<br />

11,888,774 428 3,851,963<br />

91,955,109 3,310 29,793,455<br />

13,923,000 501 411,052<br />

5,388,040 194 1,745,725<br />

4,303,711 155 1,394,402<br />

115,729,164 4,166 37,496,249<br />

Fowls raised on<br />

bedding<br />

Litter output<br />

(‘000 <strong>to</strong>nnes)<br />

Energy Content<br />

(GJ)<br />

17,361,450 625 5,625,110<br />

22,853,361 823 7,404,489<br />

2,133,092 77 691,122<br />

5,809,647 209 1,882,326<br />

5,857,657 211 1,897,881<br />

12,363,066 445 4,005,633<br />

13,688,062 493 4,434,932<br />

11,888,774 428 3,851,963<br />

91,955,109 3,310 29,793,455<br />

13,923,000 501 411,052<br />

5,388,040 194 1,745,725<br />

4,303,711 155 1,394,402<br />

115,729,164 4,166 37,496,249


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A1.2 Forestry Arisings<br />

The following table gives more detail regarding <strong>to</strong> potential Forestry residue arisings and <strong>the</strong>ir energy<br />

content, if no account of competing markets is made.<br />

Table 97 Current potential operationally available forestry residue resources <strong>by</strong> region (in <strong>the</strong> absence of<br />

competing markets)<br />

Region<br />

Forestry and Sawmill Co-<br />

Woodland (odt pa) product (odt pa)<br />

Arboricultural<br />

arising (odt pa)<br />

Total<br />

(odt pa)<br />

East Midlands 53,046 7,664 50,363 111,073<br />

East of England 70,489 24,577 37,357 132,423<br />

North East 82,956 50,615 11,133 144,704<br />

North West 86,063 37,899 25,979 149,941<br />

South East 94,994 22,191 119,160 236,345<br />

South West 125,633 27,204 27,012 179.849<br />

West Midlands<br />

Yorkshire and<br />

41,966 100,460 7,115 149,541<br />

Humberside 63,285 18,969 23,814 106,068<br />

Total England 618,432 289,579 301,933 1,209,944<br />

Scotland 848,345 403,538 12,448 1,251,883<br />

Wales 272,735 165,783 6,841 438,518<br />

Total Great Britain 2,919,634<br />

181


1.3 Waste Wood Arisings<br />

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Table 98 Summary of <strong>the</strong> main <strong>report</strong>s that investigate arisings of waste wood from Construction and Demolition Activities.<br />

Source Data Quality Findings<br />

TRADA: wood residues – waste or<br />

resource? 1999 304<br />

Recycling of construction materials<br />

(IDE and NFDC), IDE, 1990 305<br />

Nottingham Trent University<br />

Study 306<br />

Environment Agency for England<br />

and Wales, Survey on wood waste<br />

from <strong>the</strong> Construction and<br />

Demolition sec<strong>to</strong>r 307<br />

Enviros’ Study of Nor<strong>the</strong>rn Ireland’s<br />

Construction and Demolition waste,<br />

2001 308<br />

• Construction waste data originates from BRE’s SmartWaste method:<br />

visual inspection of skip contents.<br />

• Data quality was judged as ‘very poor quality’, and containing<br />

considerable uncertainties. Therefore this data has not been used in<br />

subsequent discussions.<br />

• Demolition waste estimates rely on <strong>the</strong> compositional data ga<strong>the</strong>red<br />

through a desk data ga<strong>the</strong>ring exercise <strong>by</strong> <strong>the</strong> Institution of Demolition<br />

Engineers (IDE) in 1989. Total demolition waste also established from<br />

this survey.<br />

• Data quality was judged as ‘very poor quality’, and containing<br />

considerable uncertainties. Therefore this data has not been used in<br />

subsequent discussions.<br />

• The study measured <strong>the</strong> wood content of C&D waste stream <strong>to</strong>ge<strong>the</strong>r<br />

with waste from industries supplying construction products. Therefore it<br />

is not possible <strong>to</strong> know <strong>the</strong> composition of waste arising wholly from<br />

construction and demolition.<br />

• Composition established <strong>by</strong> manually sorting and weighing small skip<br />

contents in Nottingham in three successive years.<br />

• The quantities of waste sorted as part of this work were low, and <strong>the</strong><br />

data quality was assessed as having considerable uncertainties.<br />

• Considered C&D arisings for Wales in 2005-6.<br />

• Obtaining data was not straight forward as many companies did not<br />

keep records, or take an interest in responding <strong>to</strong> <strong>the</strong> survey.<br />

• Data is from a survey at <strong>the</strong> point of disposal of C&D wastes, and a<br />

survey based on point of arising.<br />

• Enviros indicated that this figure is probably an underestimate of <strong>the</strong><br />

true figure, since some wood would have been categorised as “o<strong>the</strong>r<br />

C&D wastes including mixed wastes.”<br />

• It should be noted that <strong>the</strong>re are a number of assumptions in <strong>the</strong><br />

estimates which could affect <strong>the</strong> quality of <strong>the</strong> estimation, but <strong>the</strong> data<br />

was assessed as being of reasonable quality.<br />

Woodwaste arisings in Scotland – • Taking <strong>the</strong> annual C&D <strong>to</strong>nnage of 6.28 million <strong>to</strong>nnes and assuming<br />

2% is waste wood.<br />

• Construction wood waste estimates were 25.77% and 19.3%.<br />

• Using <strong>the</strong> lower estimate of 19.3%, as a fraction of 10 million <strong>to</strong>nnes<br />

<strong>to</strong>tal UK construction waste arisings.<br />

⇒ Construction: 1,930,000 <strong>to</strong>nnes<br />

• Identified that 7% of demolition waste arisings were wood.<br />

• Multiplying this percentage <strong>by</strong> <strong>the</strong> <strong>to</strong>tal demolition waste of 25 million<br />

<strong>to</strong>nnes yields an arisings figure of:<br />

⇒ Demolition: 1,875,000 <strong>to</strong>nnes<br />

• An estimated average wood composition of 12.44% was identified.<br />

• As this value includes waste from <strong>the</strong> construction products industry, it<br />

is likely <strong>to</strong> be a high estimate.<br />

• Of <strong>the</strong> 12.2 million <strong>to</strong>nnes produced in this period, 3% of C&D waste<br />

was wood.<br />

⇒ 366,000 <strong>to</strong>nnes.<br />

• Identified waste wood <strong>to</strong> be 1.5% of construction and demolition waste,<br />

as a minimum figure.<br />

• Waste Watch - % of C&D waste that is wood is 2%<br />

⇒ 125,600 <strong>to</strong>nnes<br />

304<br />

This reflects TRADA’s comments on collection of wood waste information, Riddoch S TRADA: wood residues – waste or resource? 1999.<br />

305<br />

Recycling of construction materials – Joint survey <strong>by</strong> Institute of Demolition Engineers and National Federation of Demolition Contrac<strong>to</strong>rs (IDE and NFDC), IDE, 1990.<br />

306<br />

A comparative study of <strong>the</strong> quantities of construction waste arising in large and small skips in <strong>the</strong> Greater Nottingham area, Nottingham Trent University and APT for ShanksFirst Wastes Solutions and Nottingham City Council,<br />

2001.<br />

307<br />

A survey on <strong>the</strong> arising and management of construction and demolition waste in Wales 2005-06, Environment Agency, 2006, http://www.environment-agency.gov.uk/research/library/publications/33979.aspx<br />

308<br />

Construction and Demolition Waste Survey, Enviros Consulting Ltd for <strong>the</strong> Nor<strong>the</strong>rn Ireland Environment and Heritage Service (NIEHS), http://www.ni-<br />

environment.gov.uk/construction_and_demolition_waste_survey_nor<strong>the</strong>rn_ireland_2001.pdf.


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Remade Scotland, 2004. 309 • No explanation for <strong>the</strong> figure of 2%.<br />

BigREc Survey – A survey of <strong>the</strong><br />

UK reclamation and salvage trade<br />

2007 310<br />

Table 99 Estimates of industry specific waste wood arisings<br />

• Generated estimations of reclaimed and salvaged wood from a survey<br />

conducted in 1998, BigREc Survey, Salvo and BRE.<br />

• Data was ga<strong>the</strong>red from postal surveys with low response rate.<br />

• The methodology of how <strong>the</strong> responses were grossed up <strong>to</strong> a national<br />

figure is unclear, which makes it difficult <strong>to</strong> rate how reliable <strong>the</strong><br />

estimate is.<br />

• It is <strong>the</strong> only available data.<br />

• Total salvaged wood in <strong>the</strong> UK estimated <strong>to</strong> be 634,000 <strong>to</strong>nnes.<br />

C&I Industry Data Quality Waste Wood Arisings<br />

(<strong>to</strong>nnes)<br />

Furniture Manufacturing Sec<strong>to</strong>r 311 • Covers UK, 2000 – 2003<br />

530,511<br />

• Data quality is ei<strong>the</strong>r containing considerable uncertainties, or is poor.<br />

Manufacture of panelboards (MDF<br />

and chipboard only) 312<br />

• No estimate is made of how much of this waste is used for heat or power within <strong>the</strong> panel board<br />

industry or of <strong>the</strong> quality of <strong>the</strong> wood.<br />

1,107,074<br />

• Data covers <strong>the</strong> whole of UK, and is of ‘good quality’.<br />

Manufacture of wooden products for<br />

<strong>the</strong> construction industry 313<br />

• Figures can be broke down in<strong>to</strong>:<br />

• 181,522 <strong>to</strong>nnes (England and Wales),<br />

201,298<br />

• 17,991 (Scotland) and<br />

• 1,785 (Nor<strong>the</strong>rn Ireland)<br />

• Data contains considerable uncertainties or is of poor quality.<br />

Manufacture of wooden<br />

• Data covers <strong>the</strong> whole of <strong>the</strong> UK, and contains considerable uncertainties or is of poor quality. 40,000<br />

packaging 314<br />

Manufacture of o<strong>the</strong>r products of<br />

wood<br />

• EA waste production survey model run for Nikitas et al (2005) covering England and Wales 296,232<br />

Production of Railway Sleepers • From Nikitas et al (2005) own study.<br />

26,000<br />

• Data covers <strong>the</strong> whole of <strong>the</strong> UK and is of ‘good quality’.<br />

Utility poles • Data covers <strong>the</strong> whole of <strong>the</strong> UK.<br />

23,500<br />

• Several surveys performed, but few <strong>to</strong>ok account of regional density variations.<br />

• Nikitas et al corrected for this, and is believed <strong>to</strong> be <strong>the</strong> best estimate.<br />

Wood waste from ‘o<strong>the</strong>r’ C&I • Environment Agency’s waste production Survey, covering England and Wales. No information<br />

2,552,312<br />

arisings<br />

available for Scotland and Nor<strong>the</strong>rn Ireland.<br />

309 Woodwaste arisings in Scotland – assessment of available data on Scottish woodwaste arisings<br />

310 BigREc Survey, A survey of <strong>the</strong> UK reclamation and salvage trade, 2007, http://www.crwplatform.co.uk/conwaste/assets/Publications/BigREc<strong>full</strong><strong>report</strong>.pdf<br />

311 Furniture manufacture sec<strong>to</strong>r estimate is based on an average of three studies: Evaluation of waste production, utilisation, and brokerage potential within <strong>the</strong> UK furniture industry, FIET, 2002; Wood waste recycling in furniture<br />

manufacturing – a good practice guide, BFM, 2003; The use of microwave technology for <strong>the</strong> recovery of wood fibre from MDF, FIRA, 2004<br />

312 Determining <strong>the</strong> market share of recycled materials – Stage 2 case study <strong>report</strong>, Esys Consulting, 2004<br />

313 Environment Agency waste production survey 1998<br />

314 Based on “Trada- Turning a blind eye?” <strong>report</strong>, 2001<br />

183


184<br />

Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Wastes and Energy<br />

AEA/ED45551/Issue 1<br />

• Calculated <strong>by</strong> subtracting figures from known industries sawmill wastes, wood products industry,<br />

furniture wastes) away from <strong>to</strong>tal arisings.<br />

• Likely <strong>to</strong> include waste wood from refurbishing industry – may be double counting with <strong>the</strong> C&D<br />

waste stream.<br />

• Likely <strong>to</strong> include a significant proportion of packaging waste.<br />

• Data is likely <strong>to</strong> be of ‘poor quality’ as based on visual inspections.<br />

Table 100 Estimations of future Waste wood arisings from various waste streams.<br />

Year<br />

MSW arisings<br />

(‘000 <strong>to</strong>nnes, no<br />

furniture)<br />

MSW furniture<br />

(‘000 <strong>to</strong>nnes)<br />

C&D<br />

(‘000 <strong>to</strong>nnes, mid<br />

range estimate)<br />

C&I<br />

(‘000 <strong>to</strong>nnes)<br />

2005 1,097 620 5091 6,563<br />

2006 1,113 629 5116 6,579<br />

2007 1,130 639 5142 6,595<br />

2008 1,147 648 5167 6,612<br />

2009 1,164 658 5193 6,628<br />

2010 1,181 668 5219 6,644<br />

2011 1,199 678 5245 6,661<br />

2012 1,217 688 5271 6,678<br />

2013 1,235 698 5298 6,695<br />

2014 1,254 709 5324 6,712<br />

2015 1,273 719 5351 6,729


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Appendix 2<br />

Waste Legislation<br />

Waste management strategies<br />

The European Union has become <strong>the</strong> major source of environmental legislation and guidance in<br />

relation <strong>to</strong> <strong>the</strong> management of waste. A number of European Directives which aim <strong>to</strong> increase levels<br />

of recycling and recovery, and thus reduce <strong>the</strong> amount of waste which is landfilled, have been<br />

introduced:<br />

• Framework Directive on Waste (75/442/EEC)<br />

• Landfill Directive (1999/31/EC)<br />

• Directive on Packaging and Packaging Waste (94/62/EEC)<br />

• Waste Electrical and Electronic Equipment Directive (2002/96/EC)<br />

• End of Life Vehicles Directive (2000/53/EC)<br />

• Ozone Depleting Substances (Regulation 2037/2000)<br />

• Directive on Batteries (2006/66/EC)<br />

• Waste Incineration Directive (2000/76/EC)<br />

Although most waste legislation in <strong>the</strong> UK has been introduced <strong>to</strong> meet <strong>the</strong> requirements set <strong>by</strong><br />

European Directives, <strong>the</strong> UK Government has also introduced additional legislation, some of which,<br />

such as <strong>the</strong> Landfill Tax Regulations 1996, is specifically aimed at encouraging recycling.<br />

Landfill Directive<br />

The European Commission Landfill Directive of 1999 (1999/31/EC) was passed in<strong>to</strong> English and<br />

Welsh law in 2002, and Scottish law in 2003. This aims <strong>to</strong> prevent, or minimise, <strong>the</strong> negative effects<br />

on both <strong>the</strong> environment and human health caused <strong>by</strong> landfilling of wastes. The Directive requires <strong>the</strong><br />

amount of biodegradable municipal solid waste (MSW) sent <strong>to</strong> landfill in <strong>the</strong> UK <strong>to</strong> be reduced:<br />

• <strong>to</strong> 75% of 1995 levels <strong>by</strong> 2010,<br />

• <strong>to</strong> 50% of 1995 levels <strong>by</strong> 2013, and<br />

• <strong>to</strong> 35% of 1995 levels <strong>by</strong> 2020.<br />

The Government has implemented <strong>the</strong> requirements for land filling of biodegradable waste through <strong>the</strong><br />

Waste and Emissions Trading Act 2003. This sets Waste Disposal Authorities annual allowances<br />

limiting how much biodegradable municipal waste (BMW) can be landfilled in any particular year, with<br />

effect from April 2005. The Government will fine Authorities that do not achieve <strong>the</strong>ir annual targets,<br />

but will allow Authorities <strong>to</strong> buy allowances from o<strong>the</strong>r Waste Disposal Authorities if <strong>the</strong>y expect <strong>to</strong><br />

landfill more than <strong>the</strong>ir allocations and sell <strong>the</strong>ir surplus if <strong>the</strong>y expect <strong>to</strong> landfill less than <strong>the</strong>ir<br />

allowance.<br />

The Landfill Directive also sets a requirement that only waste that has been subject <strong>to</strong> treatment can<br />

be landfilled. This requirement applied <strong>to</strong> landfilling of hazardous waste from July 2004, and was<br />

extended <strong>to</strong> all wastes (such as commercial and industrial wastes) destined for landfill (with some<br />

exceptions) from 30 Oc<strong>to</strong>ber 2007. A number of European countries have introduced 315 legislation<br />

which bans <strong>the</strong> landfilling of wastes with biological activity and intrinsic energy above set de-minimis<br />

limits. These restrictions apply <strong>to</strong> all wastes irrespective of <strong>the</strong>ir origin, and compliance is impossible<br />

without some form of treatment - mechanical, biological or <strong>the</strong>rmal. However, <strong>the</strong> guidance 316 for <strong>the</strong><br />

UK indicates that provided some source separation of recyclable material has occurred, <strong>the</strong> waste can<br />

be landfilled without requiring any fur<strong>the</strong>r treatment. The Government intends <strong>to</strong> consult on whe<strong>the</strong>r<br />

<strong>the</strong> introduction of fur<strong>the</strong>r restrictions on <strong>the</strong> landfilling of biodegradable wastes or recyclable materials<br />

would make an effective contribution <strong>to</strong> meeting <strong>the</strong> objectives (reducing greenhouse gas emissions<br />

315 Delivering Key Waste Management Infrastructure : Lessons Learned from Europe. Final Report <strong>by</strong> SLR <strong>to</strong> CIWM, November 2005<br />

316 Treatment of non-hazardous waste for landfill. Environment Agency, February 2007.


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and increasing resource efficiency) set out in <strong>the</strong> national waste strategy, but this would (due <strong>to</strong> <strong>the</strong><br />

need <strong>to</strong> construct <strong>the</strong> required treatment capacity) be a long term (at least 2020) target.<br />

National waste strategies<br />

An updated waste strategy for England 317 was published in May 2007. The aim of this updated Waste<br />

Strategy, which sets <strong>the</strong> Government’s vision for sustainable waste management, is <strong>to</strong> reduce waste<br />

<strong>by</strong> making products with fewer natural resources, and thus breaking <strong>the</strong> link between economic growth<br />

and waste growth. Products should be re-used, <strong>the</strong>ir materials recycled, energy from waste<br />

recovered, and landfilling of residual waste should occur only where necessary. The key points are:<br />

• Waste minimisation - A strong emphasis on waste prevention with householders reducing <strong>the</strong>ir<br />

waste (for example, through home composting and reducing food waste), business helping<br />

consumers, for example, with less packaging, development of a service which will enable<br />

households <strong>to</strong> opt-out of receiving un-addressed as well as addressed direct mail, and a<br />

reduction in <strong>the</strong> use of free single-use plastic bags.<br />

• Recycling - More effective incentives for individuals and businesses <strong>to</strong> recycle waste, leading<br />

<strong>to</strong> at least 40 per cent of household waste recycled or composted <strong>by</strong> 2010, rising <strong>to</strong> 45% <strong>by</strong><br />

2015 and 50 per cent <strong>by</strong> 2020. This is a significant increase on <strong>the</strong> targets (30% <strong>by</strong> 2010 and<br />

33% <strong>by</strong> 2015) in <strong>the</strong> previous waste strategy (which was published in 2000).<br />

• Treatment of residual waste - Increasing <strong>the</strong> amount of energy produced <strong>by</strong> a variety of<br />

energy from waste schemes, using waste that can't be reused or recycled. It is expected that<br />

from 2020 a quarter of municipal waste - waste collected <strong>by</strong> local authorities, mainly from<br />

households - will produce energy, compared <strong>to</strong> 10 per cent <strong>to</strong>day.<br />

The English waste strategy also included a new national target for <strong>the</strong> reduction of commercial and<br />

industrial waste going <strong>to</strong> landfill. This will require <strong>the</strong> level of commercial and industrial waste that is<br />

landfilled <strong>to</strong> fall <strong>by</strong> 20% <strong>by</strong> 2010 compared <strong>to</strong> <strong>the</strong> baseline of 2004.<br />

The Welsh Waste Strategy 318 , which was published in 2003, established a challenging but realistic<br />

programme of change <strong>by</strong> 2013. The aim of <strong>the</strong> strategy is <strong>to</strong> move Wales from an over-reliance on<br />

landfill <strong>to</strong> a position where it will be a model for sustainable waste management. This will be achieved<br />

<strong>by</strong> adopting and implementing a sustainable, integrated approach <strong>to</strong> waste production, management<br />

and regulation (including litter and flytipping) that minimises <strong>the</strong> production of waste and its impact on<br />

<strong>the</strong> environment, maximises <strong>the</strong> use of unavoidable waste as a resource, and minimises where<br />

practicable, <strong>the</strong> use of energy from waste and landfill.<br />

The Welsh strategy set <strong>the</strong> following targets:<br />

• Municipal solid waste<br />

o Each local authority <strong>to</strong> achieve a minimum 40% recycling/composting rate <strong>by</strong> 2009/10,<br />

with a minimum of 15% composting (with only compost derived from source<br />

segregated materials counting) and 15% recycling.<br />

o Waste arisings per household should be no greater than those (for Wales) in 1997/98<br />

<strong>by</strong> 2009/10.<br />

o By 2020, waste arisings per person should be less than 300kg per annum.<br />

• Commercial and industrial waste<br />

o Achieve, <strong>by</strong> 2010, a reduction in waste produced equivalent <strong>to</strong> at least 10% of <strong>the</strong><br />

1998 arisings figure.<br />

o Reduce, <strong>by</strong> 2010, <strong>the</strong> amount of industrial and commercial waste going <strong>to</strong> landfill <strong>to</strong><br />

less than 80% of that landfilled in 1998<br />

• C&D<br />

o To re-use or recycle at least 85% of C&D waste produced <strong>by</strong> 2010.<br />

317<br />

Waste Strategy for England 2007. Defra, May 2007.<br />

318<br />

Wise About Waste: The National Waste Strategy For Wales. Welsh Assembly Government, 2003.<br />

186 AEA


Evaluation of Opportunities for Converting Indigenous UK Wastes <strong>to</strong> Wastes and Energy<br />

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The Scottish National Waste Plan of 2003 319 establishes <strong>the</strong> direction of <strong>the</strong> Scottish Executive’s<br />

policies for sustainable waste management <strong>to</strong> 2020. It is built around a major commitment of funding<br />

<strong>by</strong> <strong>the</strong> Executive <strong>to</strong> transform Scotland’s record on waste reduction, recycling, composting and<br />

recovery. It sets out challenging, but realistic objectives <strong>to</strong> achieve fundamental change in <strong>the</strong> way<br />

that Scotland’s waste is managed, and <strong>the</strong> main targets are <strong>to</strong>:<br />

• Achieve zero growth in <strong>the</strong> amount of municipal waste produced <strong>by</strong> 2010;<br />

• Achieve 55% recycling and composting of municipal waste <strong>by</strong> 2020 (35% recycling and<br />

20% composting);<br />

• Recover energy from 14% of municipal waste;<br />

• Reduce landfilling of municipal waste from around 90% <strong>to</strong> 30%;<br />

• Provide widesp<strong>read</strong> waste minimisation advice <strong>to</strong> businesses; and<br />

• Develop markets for recycled material <strong>to</strong> help recycling become viable and reduce costs.<br />

In 2007 Scotland also published a strategy for business 320 (C&I) waste. This aims <strong>to</strong> reduce <strong>the</strong><br />

amount of business waste which is landfilled through both reducing <strong>the</strong> amount of waste which is<br />

generated and increasing <strong>the</strong> recycling rate, but it does not set specific recycling targets.<br />

The Nor<strong>the</strong>rn Ireland waste strategy 321 , which was published in 2006, sets <strong>the</strong> following targets:<br />

• Recycling and Composting of Household Wastes <strong>to</strong> increase <strong>to</strong> 35% <strong>by</strong> 2010, and <strong>to</strong> 45%<br />

<strong>by</strong> 2020.<br />

• 60% of Commercial and Industrial Waste <strong>to</strong> be recycled <strong>by</strong> 2020<br />

• 75% of Construction, Demolition and Excavation Wastes <strong>to</strong> be recycled or reused <strong>by</strong><br />

2020.<br />

The national waste strategies all set targets for recycling/composting of MSW, and include<br />

requirements <strong>to</strong> meet <strong>the</strong> targets on landfilling of biodegradable MSW set <strong>by</strong> <strong>the</strong> landfill Directive. The<br />

targets for C&I waste aim <strong>to</strong> both reduce <strong>the</strong> amount of waste which is produced and reduce <strong>the</strong><br />

amount which is landfilled, but only <strong>the</strong> Nor<strong>the</strong>rn Ireland waste strategy sets a recycling target. Two<br />

strategies (Wales and Nor<strong>the</strong>rn Ireland) set recycling targets for C&D waste.<br />

English regional strategies<br />

Although some of <strong>the</strong> English Regions have published waste strategies, o<strong>the</strong>rs have covered waste<br />

within <strong>the</strong>ir spatial strategy/plan. Table 101 lists <strong>the</strong> waste reduction/minimisation, recovery and<br />

recycling targets set in each Region, and shows that only two regions (London and <strong>the</strong> South East)<br />

have set recycling targets for all (MSW, C&I and C&D) of <strong>the</strong> three main waste streams. Table 101<br />

also shows that some regions (such as <strong>the</strong> East of England) have set recovery targets but have not<br />

set recycling targets, and that only four regions have set waste reduction/minimisation targets.<br />

O<strong>the</strong>r targets/objectives included in <strong>the</strong> strategies/plans include:<br />

• London - Ensure that facilities with sufficient capacity <strong>to</strong> manage 75 per cent (15.8 million<br />

<strong>to</strong>nnes) of waste (MSW and C&I) arising within London are provided <strong>by</strong> 2010, rising <strong>to</strong> 80<br />

per cent (19.2 million <strong>to</strong>nnes) <strong>by</strong> 2015 and 85 per cent (20.6 million <strong>to</strong>nnes) <strong>by</strong> 2020<br />

• East Midlands - To reduce <strong>the</strong> amount of waste landfilled in accordance with <strong>the</strong> EU<br />

Landfill Directive, and take a flexible approach <strong>to</strong> o<strong>the</strong>r forms of waste recovery<br />

• East of England - The objective is <strong>to</strong> eliminate <strong>the</strong> landfilling of untreated municipal and<br />

commercial waste <strong>by</strong> 2021<br />

• West Midlands - The Region must play its part in delivering <strong>the</strong> targets set out in <strong>the</strong><br />

National Waste Strategy, and development plans should include proposals which will<br />

enable <strong>the</strong> Regional targets <strong>to</strong> be met.<br />

319 Waste Action Scotland: The National Waste Plan. Scottish Executive, 2003<br />

320 Business Waste Framework. Scottish Environmental Protection Agency (SEPA) and Scottish Executive, March 2007<br />

321 Towards Resource Management: The Nor<strong>the</strong>rn Ireland Waste Management Strategy 2006 – 2020. Nor<strong>the</strong>rn Ireland Department of<br />

Environment, 2006.


Table 101: Summary of targets in regional strategies<br />

Waste<br />

Recovery targets Recycling Targets<br />

minimisation/reduction<br />

Municipal Solid Commercial and Construction and<br />

Waste industrial waste demolition waste<br />

East of<br />

England 322<br />

- Municipal waste – recovery of 50%<br />

- - -<br />

<strong>by</strong> 2010 and 70% <strong>by</strong> 2015<br />

Commercial and industrial waste –<br />

recovery of 72% <strong>by</strong> 2010 and 75%<br />

<strong>by</strong> 2015<br />

East Midlands 323 To work <strong>to</strong>wards zero Overall recycling, recovery or re- To exceed<br />

- -<br />

growth in waste at <strong>the</strong> use rate for all waste streams of Government targets<br />

Regional level <strong>by</strong> 2016 75%<br />

for recycling and<br />

composting<br />

London 324 - - Exceed recycling or<br />

composting levels in<br />

municipal waste of:<br />

35 per cent <strong>by</strong> 2010<br />

45 per cent <strong>by</strong> 2015<br />

North East 325 - Municipal Solid Waste – <strong>to</strong> increase<br />

recovery <strong>to</strong> 53% <strong>by</strong> 2010 and 72%<br />

<strong>by</strong> 2016<br />

Commercial & Industrial – <strong>to</strong><br />

North West 326 Achieve and retain 0%<br />

growth in <strong>the</strong> amount of C&I<br />

wastes produced through<br />

<strong>the</strong> life of <strong>the</strong> Strategy,<br />

without compromising<br />

economic<br />

growth in <strong>the</strong> region<br />

increase recovery <strong>to</strong> 73% <strong>by</strong> 2016<br />

MSW - recover value from 67% of<br />

MSW <strong>by</strong> 2015<br />

recover value (including recycling)<br />

from at least 70% of all commercial<br />

and<br />

industrial wastes <strong>by</strong> 2020<br />

322 East of England Plan May 2008: The Revision <strong>to</strong> <strong>the</strong> Regional Spatial Strategy for <strong>the</strong> East of England. Government Office for <strong>the</strong> East of England, May 2008<br />

323 East Midlands Regional Waste Strategy. East Midlands Regional Assembly, January 2006.<br />

324 The London Plan: Spatial Development Strategy for Greater London. Greater London Authority, February 2008<br />

325 The North East of England Plan: Regional Spatial Strategy <strong>to</strong> 2021. Government Office for <strong>the</strong> North East, July 2008<br />

326 Regional Waste Strategy for <strong>the</strong> North West. North West Regional Assembly, September 2004<br />

Achieve recycling or<br />

composting levels in<br />

commercial<br />

and industrial waste<br />

of 70 per cent <strong>by</strong><br />

2020<br />

Achieve recycling<br />

and re-use levels in<br />

construction,<br />

excavation and<br />

demolition waste of<br />

95 per cent <strong>by</strong> 2020<br />

- - -<br />

- recycle 35% of all<br />

commercial and<br />

industrial wastes <strong>by</strong><br />

2020<br />

-


South East 327 - - 55% of MSW <strong>by</strong><br />

2020<br />

65% of C&I <strong>by</strong> 2020 60% of C&D <strong>by</strong> 2020<br />

South West 328 Become a minimum waste<br />

producer <strong>by</strong> 2030, with<br />

business and households<br />

maximising opportunities<br />

for reuse and recycling.<br />

- - - -<br />

West<br />

Midlands 329<br />

- Recover value from at least 45% of Recycle or compost<br />

- -<br />

municipal waste <strong>by</strong> 2005 and 67% at least 30% of<br />

<strong>by</strong> 2015;<br />

household waste <strong>by</strong><br />

Reduce <strong>the</strong> proportion of industrial 2010, and 33% <strong>by</strong><br />

and commercial waste which is<br />

disposed of <strong>to</strong> landfill <strong>to</strong> at <strong>the</strong> most<br />

85% of 1998 levels <strong>by</strong> 2005<br />

2015<br />

Yorkshire and<br />

Humber 330<br />

Moving <strong>the</strong> management of Achieving all statu<strong>to</strong>ry waste<br />

- - -<br />

all waste streams up <strong>the</strong> management performance targets<br />

waste hierarchy<br />

during <strong>the</strong> Plan period<br />

327 A Clear Vision for <strong>the</strong> South East – The South East Plan. South East England Regional Assembly (SEERA), March 2006<br />

328 From Rubbish <strong>to</strong> Resource: The Regional Waste Strategy for <strong>the</strong> South West 2004 – 2020. South West Regional Assembly, 2004<br />

329 Regional Spatial Strategy for <strong>the</strong> West Midlands. Government Office for <strong>the</strong> West Midlands, January 2008<br />

330 The Yorkshire and Humber Plan: Regional Spatial Strategy <strong>to</strong> 2026. Government Office for Yorkshire and <strong>the</strong> Humber, May 2008


The strategies consider future requirements for management of MSW; this is because of <strong>the</strong><br />

requirements for management of this stream in order <strong>to</strong> meet <strong>the</strong> targets for landfilling of MSW set in<br />

<strong>the</strong> Landfill Directive. However, only <strong>the</strong> London strategy sets requirements for treatment capacity for<br />

C&I waste, and whilst <strong>the</strong> London and South East strategies set high (over 60%) recycling targets for<br />

C&I waste, <strong>the</strong>se are unlikely <strong>to</strong> be achieved without future changes in Government policy.<br />

AEA


Appendix 3<br />

MBT Methods<br />

Specific in use processes for MBT include <strong>the</strong> 3R-UR process, illustrated below, with a typical mass<br />

balance for <strong>the</strong> system shown in Table 102, <strong>the</strong> BTA process, 331 and <strong>the</strong> Orchid Process.<br />

Table 102: Mass balance for 3R-UR process<br />

Figure 25: Flowsheet for <strong>the</strong> 3R-UR process 332<br />

Biogas<br />

Wt %<br />

3-5<br />

Recyclables and/or fuel product 15-20<br />

Compost product 15-20<br />

Process loss (waste gas – treated in biofilters before 40-45<br />

discharge <strong>to</strong> atmosphere)<br />

Residues (landfilled) 15-20<br />

Total 100<br />

331 Information at http://www.srm-norfolk.co.uk/index.htm<br />

332 Global Renewables, 3R-UR Process, http://www.globalrenewables.eu/ur3r-process


AEA<br />

Figure 26 Process flow sheet for <strong>the</strong> BTA process 333<br />

333 The BTA Process – Implementing Anaerobic Digestion in Wales Workshop 11 th November 2008, Enpure,<br />

http://www.swea.co.uk/downloads/Biogas_ROBYN.pdf


Figure 27 Orchid Environmental process 334<br />

334 Orchid – Seamless Waste Management Solutions, Company Brochure, http://www.orchidenvironmental.co.uk/downloads/pdf/orchid_process_4pp.pdf


AEA group<br />

329 Harwell<br />

Didcot<br />

Oxfordshire<br />

OX11 0QJ<br />

Tel: 0870 190 6036<br />

Fax: 0870 190 6318<br />

AEA

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