Energy from Biomass Lecture 1 - Mechanical Engineering

Energy from Biomass 

4S610 

Lecture 1 

Jeroen van Oijen & Rob Bastiaans

Lecturers Energy from Biomass 

Jeroen van Oijen 

j.a.v.oijen@tue.nl 

GEM-N 1.48, T: 3133 

Rob Bastiaans 

r.j.m.bastiaans@tue.nl 

GEM-N 1.46, T: 4836 

/ Mechanical Engineering 13-11-2012 PAGE 1

Today 

• Combustion technology and biomass 

• Course info, philosophy, planning, info 

• Greenhouse effect 

• Qualitative, evidence 

• Quantitative 

• Carbon Cycle 

• Policies 

• Resources 

• Potential 


Course material 

• OASE 

• Website 

http://w3.wtb.tue.nl/en/research/research_groups/combus 

tion_technology/education/energy_from_biomass/ 

• Reader 

• Lectures 

• Practical work 


Mechanical Engineering 13-11-2012 PAGE 4

Combustion technology 

Combustion technology is 

Technology dedicated to development of new methods and 

improvement of existing methods and equipment used for efficient 

and clean conversion of ‘chemical energy’ in the form of fuel to 

another usable form like heat, electrical energy, and kinetic energy, 

or… (another) fuel. 

So, it includes biomass! 


Combustion technology 

• Before 1970: Mainly empirical 

• After 1970: Combustion science 

• Development of advanced measurement techniques 

• Proper computation techniques / increasing computer 

speed 

• Social need 

− Clean 

− Efficient 

• Oil crisis 

• Depletion/greenhouse problems 


Combustion technology and biomass 

• Combustion is about 

• Physical transport phenomena 

• Chemical conversion 

• Efficiency 

• Emissions 

• Analysis and insight in processes 

• Not about: 

• detailed construction aspects 

• strategic / political choices 


Combustion Technology @ TU/e 

• Experimental, numerical, applied research 

• Applications 

• Domestic burners 

• Internal combustion engines 

• Gas turbines 

• Industrial furnaces 

• Gaseous and liquid fuels 

• Biomass challenge: solid fuel 


Biomass research at CT 

• EU project OPTICOMB 

• Optimization of biomass combustion systems 

• 2003 - 2007 

• Partners 

• TNO 

• VT-TU Graz 

• CT-TU/e 

• Vyncke, … 


OPTICOMB 

• Goal: Increase (fuel) flexibility of biomass 

combustion installations 

• Control 

• Guide lines NOx and 

CO reduction 

• Efficiency increase 

• Design rules 

• Test of new design 

• Crucial role CFD, 

chemistry model, 

NO formation 


OPTICOMB Task TU/e 1 

Biomass fuel characterization with grid reactor 

Result 

• Chemical kinetics parameters 

for biomass fuel 

• Model for combustion of 

small particles 


OPTICOMB Task TU/e 2 

• CFD combustion model of gas phase products 

• Simplified NOx model 

• Coupling with fixed bed 

boundary condition 

• Verification 

• Case studies 

• Different fuels 

• Different geometry 


Articles in Energy & Fuel 

10 most cited 

articles from first 

3 months of 2010 


The course: global structure 

• Introduction 

• Resources and potential 

• Biomass characteristics 

• Basic conversion processes 

• Biomass conversion systems 

• Emissions 

Background 

Processes 

Systems 


The course: global structure 

• Transport and chemistry 

• Idealized reactors 

• Single particle conversion 

• Fixed bed conversion 

Fundamental 

Modeling 

Analysis 

• Guest lecture from industry 

• Practical work 


Course content 

• Background of biomass 

• Basics of thermal conversion 

• Technical systems 

• Physical transport processes and chemistry 

• Easy for ME and hard for SET 

Not reflected in end marks! 


Philosophy 

Biomass conversion: presently trial and error 

Therefore, vast amount of conversion systems, for 

every fuel and end-use 

Here: 

• Basic principles and processes 

• Decision making based on analysis / calculations 


Lectures 

Week Date Subject Chptr. Lecturer 

46 13-11 General introduction, greenhouse effect, Kyoto protocol, biomass 

resources. 

1 Van Oijen 

46 15-11 Biomass composition and properties, ultimate/proximate 

analysis. 

47 20-11 Thermal conversion processes 

(pyrolysis/gasification/combustion). 

47 22-11 Modelling conversion processes, 

application to simple reactors. 

2 Van Oijen 

3 Van Oijen 

4 Bastiaans 

48 27-11 Conversion of spherical particles. 4 Bastiaans 

48 29-11 Front propagation in fixed bed reactors. A Van Oijen 

49 4-12 Emissions and reduction measures, NO x and tar. 

Guest lecture. 

49 6-12 Biomass conversion systems 

(small scale/large scale). 

6 Van Oijen 

Guest 

5 Bastiaans 


Practical work 

Numerical study of biomass conversion in a fixed bed 

Numerical exercises 

Time: Thursday 8:45-11:30 

Place: Gemini-Zuid 3a.05 

Instructors: J.A. van Oijen, R.J.M. Bastiaans and A. Donini 

Week Date Subject 

50 13-12 Introduction to Comsol and first simulations 

51 20-12 Simulating reaction front propagation in fixed bed. 

2 10-1 Idem. 

Groups of 2 students write a report 

Results count for 1/3 of final grade 


Examination 

Time: Wednesday, January 22, 2013, 9:00-12:00 

Place: To be determined 

Observer: J.A. van Oijen 

No books/notes allowed 

Bring a calculator 

Report: Before examination 


How to study 

Read reader (slides from last year) before the lecture 

Follow the lecture 

Study the lecture (exercise exam questions) 

if needed take reader; or ask lecturers 

Material in lectures is leading in the assessment 


Information on biomass 

Internet 

• Vast source of information 

• Many organizations 

• Up-to-date information 

• Validity 

Dutch: VROM, RIVM, CBS, ECN, Verantwoord Groen, 

etc. etc. 

International: EU, UN, WEC, IEA, OECD, IPCC, WMO, 

DOE, etc. etc. 


Information 

Books 

• Generally better than internet 

• At least edited 

• Not always up-to-date 

• Handbook Biomass Combustion and Co-firing, van Loo and 

Koppejan, eds., Twente University Press. 

• Handbook Biomass Gasification, Knoef editor, BTG, Biomass 

Technology Group 

• Handbook of Biomass Downdraft Energy Systems, Reed & Das. 

• Thermochemical Processing of Biomass, Brown editor. 


Introduction 

Global warming and biomass 

• Renewable energy 

• Greenhouse effect 

• Carbon cycle 

• Policies 

• Biomass usage 


Biomass combustion 

Fire from 

biomass 

1 million 

Year ago 


What is biomass 

Biomass regulation 2001/77/EG sustainable energy: 

‘the biological degradable fraction of products, 

wastes and residues from agriculture (including 

animal and vegetable materials), forestry and the 

biological degradable fraction of industrial and 

household wastes’ 


What about oil and gas 

• Well defined, 

high energy content, 

easy to use, etc. 


However… 


Energy scenario WEA (UN) 


Why biomass 

• Can be sustainable 

• Short carbon cycle 

• Considered to be CO 2 neutral 

• No additional greenhouse effect 

• Large scale availability 

• Independent energy production 

• Cheaper than oil (if all costs are included) 


The greenhouse effect 



Evidence 1 



Evidence 2 



Evidence 3 



Evidence 4 



Evidence 5 


Different models 

Greenhouse effects predictions 

Anthropogeneous 

temperature 

increase 


Discussion 

We must decrease CO 2 emissions. 

What is prefered: 

1) An engine with high CO 2 emission 

per kg of fuel 

2) An engine with low CO 2 emission 

per kg of fuel 


How the greenhouse effect works









How the greenhouse effect works 

Global warming 

• We had a qualitative view 

• But can we quantify 

• Let us do an estimation! 

• How



• How 

• Based on radiation equilibrium 

• The sun radiates to the earth: S=1368 W/m 2 

• The earth radiates to the universe



• Albedo A, incoming radiation is effective for (1-A) 

• Albedo due to earth surface and atmosphere 

• Equation for reception of solar energy


 

 

( 1 

A) SR 

2




• Equation for radiation from earth to the universe 

 

A T 

4


In: 

 

 

( 1 

A) SR 

2 

Out: 

 

4R 2 

T 

4


How does it work 

Radiation equilibrium: 255 K (-18 ℃) 

The radiation trap increases the temperature 

Add atmosphere in the model: 303 K (30 ℃) 

Add emissivity coefficient: 290 K (17 ℃) 

Real value: ~ 15 ℃

The carbon cycle: Photosynthesis 


The carbon cycle 


The carbon cycle 


Not new… 

But: Risk = Probability x Consequence 


Biomass: harvesting sunlight 

10.000x annual need 

10x annual need 


Use of biomass 

• Direct combustion (heat) 

• Gasification (solid to gas) 

• Combustion 

• Conversion: 

• Liquid fuels (FT diesel) 

• Hydrogen 


Biomass carbon cycle 

CO 2 

Fuel 


Biomass energy plant 

Not much different from coal-fired power plant 


Policies 

The Kyoto protocol (COP3 1997) 

• Legally binding emission targets for Annex I 

(developed) countries 

• Reduction of greenhouse gases by 5% in 2008-2012 

• Reference year is 1990 

• Basket contains CO 2 , CH 4 , N 2 O, HFC’s , PFC’s, and 

SF 6 


Kyoto protocol 

• Europe: -8% 

• The Netherlands: -6% 

• Possibility for “emissions trading” 

• Into force if 55 parties representing 55% of 1990 CO 2 

emissions agree 

• Russia ratified in February 2005 

• Official at conference Montreal, November 2005 


Kyoto protocol for the Netherlands 

• 6% reduction 

• 50% domestic 

• 50% foreign, “emission trading” 

• Acquisition of 50 billion ton CO2 

equivalents @ 4-5 € → 400-500 M€ 

• The Dutch seemed to be on track… 

• New negotiations failed at Copenhagen 


Greenhouse gas emissions NL 


European policy 

• CO2 trading scheme 

• 20-20-20 policy 

• 20 % renewables (of which 40% biomass) 

• 20 % reduction in energy use 

• 20 % less CO2 emissions (1990) 

• Point of view: not exceed 2K temperature increase 


Resources and potential 


Facts and figures 

• Global energy consumption: 

• 400 exajoules 

• Annual production of biomatter: 

• 220 billion oven dry tons 


• Theoretically harvestable bioenergy: 


• Technically available on sustainable basis: 



Biomass challenge 

Biomass challenge is not availability, but 

sustainable management, conversion and delivery 

to the market. 

The Stone Age did not end for lack of stone 

and the oil industry will end long before the 

world runs out of oil (Sheikh Zaki Yamani) 


Facts and figures 

• Current bio-energy consumption: 

• 50 exajoules (11%) 

• Developing countries (China, India) 

• Biomass 35% of their total 

• Poorest countries 

• Biomass 90% of their total 

• Traditional, non-commercial forms 


Perception and problems 

Fuel of the past 

• Associations with poverty 

• High pollution 

• Health problems in developing countries 

• Low efficiency 

• High water content 

• Quality unpredictable 

• Land use for energy crops 

• Water use 


A definition of biomass 

Biomass regulation 2001/77/EG sustainable energy: 

‘the biological degradable fraction of products, 

wastes and residues from agriculture (including 

animal and vegetable materials), forestry and the 

biological degradable fraction of industrial and 

household wastes’ 


Classification (WEA) 

• Vegetable/plant biomass 

• Woody 

• Non-woody 

• Processed waste 

• Animal biomass 

• Municipal solid waste 


Municipal solid waste 

• 1-2 kg solid waste per capita every day in 

industrialized countries 

• Energy contents: 4-13 MJ/kg 

• Energy conversion is profitable 

• Waste incineration requires tight air pollution 

abatement 


Resources 

• Residues/wastes from 

• Agriculture (straw) 

• Forestry (treetops, branches) 

• Wood industry (bark, sawdust) 

• Food industry (olive stones) 

• Energy crops (miscanthus, switch grass) 


Residues and wastes 

• By-products of agro-industry and forestry 

• Energy content is more than 1/3 of global 

commercial energy use 

• 30% is recoverable 

• Limited by 

• Impracticability of recovering 

• Need to leave residues at the site (fertilization) 


Energy crops 

• Food crops (sugar cane, sugar beet, wheat, 

rapeseed) 

1 st generation biomass 

• Woody or grassy materials, (miscanthus, 

hemp, grass, poplar, eucalyptus, etc.) 

2 nd generation biomass

Potential of energy plantations 

Large part of biomass supply, but 

• Availability of land 

• Regional distribution 

• Productivity of the land 

• Environmental implications 

• Performance of conversion technologies 


Global land-use pattern 

Gha 

% of total 

WEA 2000 

Cropland 1.5 11 

Forests 4.2 32 

Pastures 3.4 26 

Other 4.0 31 

1.6-1.8 rainfed 

Gha = 10 13 m 2 

Total 13.1 100 


Projected biomass energy potential 

Gha 

WEA 2000 

Cropland potential in 1990 2.6 

Cultivated in 1990 0.9 

Additional required in 2050 0.4 

Extra for biomass 1.3 

Extra bio-energy 

400 EJ 

15 ton/ha 

20 GJ/ton 


World Energy Outlook 2006 

• “Energy farming on current agricultural land could 

contribute up to 700 exajoule per year of biomass 

energy by 2050 without jeopardising the world’s food 

supply, forests or biodiversity – assuming very rapid 

technological progress.” 


Water resources 

• Supply of fresh water may 

become a limiting factor 

• Availability for biomass 

production has not been 

addressed in detail 

• Even without biomass 

production, water shortages 

are possible for half the world’s 

population in 2025 


Productivity of land 

• Production depends on climate, soil, and 

management conditions 

• Net energy yield 30-500 GJ/ha/year 

• Perennial crops annual crops 

• Irrigation, fertiliser, genetics 


Transport of biomass 

• Transport costs 0.5 MJ/ton/km 

• Distance limited to 100 km 

• Surface still 10 5 ha 

• Enough supply for hundreds 

of megawatts 

• Transport by sea 

• Latin America to Europe: 

energy loss < 10% 

• Common practice (wood for 

paper/pulp) 


Environmental implications 

• Water use 

• Erosion 

• Perennials (willow, poplar, eucalyptus) 

• Agrochemicals / Pesticides 

• Perennials 10x less than for food crops 

• Nutrients / Fertiliser 

• Biological fertilisers 

• Recycling of ashes 


Environmental implications 

• Biodiversity and landscape 

• Only a risk for virgin forests 

• Not for degraded lands or excess agricultural lands 

• Health risks 

• Fire 

• Diseases 

• Conversion and end use 

• Clean combustion 


Economy of biomass 

• Profitable when cheap or negative cost residues or 

wastes are available 

• Plantation biomass production costs 

• 1.5-2.0 $/GJ in developing countries 

• 4 $/GJ in NW Europe 

• 1.5-2.0 $/GJ for US in 2020 

• Electricity production costs 

• 0.05 $/kWh using current technology 


Economy of biomass 

Not yet competitive, but… 

• Technology will improve 

• Costs will go down 

• Fossil fuels become more expensive 

• Low investment costs: 

• Co-firing with coal or natural gas 


Summary and conclusions 

• Modern problems: 

• Energy shortage 

• Environmental problem, greenhouse effect 

• Biomass might be a solution for both (why) 

• This is about thermal biomass conversion 

• Potential seems to be promising 

• Economy seems to become promising 

• Policies are important 


Next time 

• Properties of biomass 

• Chemical 

• Physical 

• Mechanical 

• Determination of these properties 

• How to use them in decision making 

• Prelude to conversion processes 


Questions

Energy from Biomass Lecture 1 - Mechanical Engineering

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