to read the full report - Ecolateral by Peter Jones

96
Evaluation of Opportunities for Converting Indigenous UK Wastes to Wastes and Energy
AEA/ED45551/Issue 1
7.1 Technologies for manufacturing fuels
7.1.1 Mechanical / biological processing of MSW to Solid Recovered Fuel
(SRF)
C & I waste
MSW
Process Description
Mechanical/biological treatment (MBT) encompasses a wide range of technologies aiming to process
solid waste by a mixture of mechanical and biological separation. 164 It is not a new technology, and
mechanical sorting and biological treatment processes have been used for many years in municipal
waste management.
MBT plants produce a solid recovered fuel (SRF) product from the drier, higher calorific value fractions of
municipal and commercial waste. The first step is aerobic digestion, or fermentation, of solid organic
material (composting) with the produced heat drying the waste. It is then mechanically sorted to produce
a fuel product that contains mainly paper and plastic. Additional fractions are produced that are suitable
for recovery and recycling such as metal, glass and plastic, whilst the remaining waste is stabilised as a
pre-treatment to landfill.
Commercial status
MBT is commercially available in most countries in the EU, and in the UK there are a number of
operational sites, these are listed below.
Table 48 Risks and barriers for MBT
Level of Risk Comment
Technical Low Operating commercial plant in existence.
Established mature technologies.
Social & Planning Medium Not as divisive as an incinerator but still subject of
concern as a waste technology. Waste transport
is always a primary concern of residents in the
locality.
Financial Medium Requires revenue from sale of fuel but market not
well established.
Fuel is still classed as a waste which may give
problems with sale and use and hence price.
Standards and agreed specifications are needed
to make the fuel product a traded commodity.
Regulatory Medium Fuel is still classed as a waste which may give
problems with sale and use and hence price.
The legal status needs to be clarified. Standards
would help to clarify definitions.
Focusing on one site to give a detailed example of the processes used, the Frog Island site in east
London is a recent development using the proprietary Ecodeco process. This process first shreds the
waste, then dries it for up to 15 days using the heat from the composting biomass to reduce its moisture
164 Mechanical Biological Treatment of Municipal Solid Waste. Prepared by Enviros Consulting Limited on behalf of Defra as part of the New
Technologies Supporter Programme, 2007.
Mechanical/Biological
Treatment (MBT)
SRF