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Municipal and wood waste could be transformed into transport biofuel with enhancements to a process that chemically decomposes substances by heating.


biofuel wood waste
Wood waste ready for processing into biofuel chips

The process – known as pyrolysis – is being developed for mass-scale biofuel production by a consortium of British businesses led by Axion Energy.

The Carbon Trust, which has invested £7m into the effort, claims a process that uses existing organic waste, rather than plant crops, overcomes many of the sustainability issues associated with some current biofuels.

This also has significant potential to reduce emissions because the waste would otherwise go to landfill, where it would rot and produce methane.

The basic principles behind pyrolysis have been studied for almost 30 years, but the process must be made more ’elegant’ if it is to produce useable fuels, explained David Penfold, research and development manager at the Carbon Trust.

He said: ’Basically, pyrolysis is the heating of a material in the absence of oxygen at temperatures of approximately 500oF. What happens then is you get a thermal decomposition.

’In the case of this project, it is a biomass that will be degraded to a bio-oil, which is more or less charcoal and a mixture of non-condensable gasses.’

Penfold explained that currently these bio-oil products are acidic and contain high levels of oxygen and water, meaning they are in no condition to be used as a liquid transfer fuel.

The consortium will aim to enhance the pyrolysis process and slightly change its chemistry using catalytic techniques to improve the product.

There will also be development work on chemical methods for refining the product, after the pyrolysis process, to ensure that it is ready to blend with diesel.

Penfold said: ’Currently. under the renewable transport fuel obligation, 3.25 per cent of fuel that you get from your pump at Tesco or Sainsbury’s,for instance, is biofuel.’ He added that by 2020 a European Union (EU) directive will see this figure rise to 10 per cent.

The consortium aims to produce its first biofuel from a pilot plant in 2014 and there is potential, using UK biomass alone, to scale production to more than two million tonnes per year.

Along with Axion Energy, the pyrolysis consortium comprises Catal International, CARE and Aquafuels Research.