RAEng report calls for waste-based biofuels

Article by Helen Tunnicliffe

BIOFUELS should be made from waste and byproducts, not food crops, if their carbon emissions reduction potential is to be realised, according to a new report from the Royal Academy of Engineering (RAEng).

The report’s authors, including IChemE Fellows Adisa Azapagic, who chaired the working group, Raffaella Ocone and Nilay Shah, and Associate Fellow David Lemon, note previous RAEng work which suggests that all low carbon technologies will be required to meet carbon reduction targets. Under EU regulations, by 2020 10% of transport fuels should be from renewable sources, but at present only around 4.75% biofuel is blended into petrol and diesel. While electric-powered cars are a viable alternative to those running on fossil fuels, the authors believe that some sectors, such as aviation, shipping and heavy goods transport, will continue to require liquid fuels for the foreseeable future, and here, biofuels will be essential.

Sustainability of liquid biofuels was commissioned by the UK’s Department of Transport and the Department of Energy and Climate Change to help inform future policy decisions. Azapagic and the team reviewed the pros and cons of different types of biofuels, reviewing existing literature, looking at life cycle assessments to determine the carbon footprints, and examining other sustainability issues, such as costs of production and competitiveness with fossil fuels, food, water and energy security, rural development and human health impacts.

First generation biofuels, made from crops like maize and oilseed rape can compete with food for land, while increased demand for agricultural land can lead to deforestation and drainage of peatland, as well as increased use of chemicals and water, which is in itself damaging to the environment. The report notes that third generation biofuels made from algal oil are at present not a viable option, and in some cases have higher overall carbon emissions than fossil fuels.

Second generation biofuels, made from dedicated biofuel crops or waste products from agriculture, sawmills, forestry, waste cooking oil, waste from whisky production and even ‘fatbergs’ in sewers, are a much better option, according to the authors. Energy crops such as Miscanthus can be grown on marginal and degraded land unsuitable for other uses such as housing or food production, minimising land use change.

For a biofuels industry to be successful, however, it will require careful regulation, taking into account life cycle assessments and carbon footprints, land use change and supply chains. The report recommends that national and global life cycle assessment databases for all types of biofuels are established to improve transparency. In addition it will be vital to have robust accreditation standards for biofuels, as at present, standards are only voluntary. There should be verification of the origin of feedstocks to ensure traceability and minimise the possibility of fraud.

The report makes a number of policy recommendations to government, including incentivising second generation biofuels and setting a cap on first generation crop-based biofuels. The government should increase the level of biofuels required under the Renewable Transport Fuel Obligation (RTFO) and strengthen certification schemes for biofuels to ensure they remain robust once the UK leaves the EU.

“Second generation biofuels offer real prospects for the UK to make progress in reducing emissions from transport, particularly in sectors like aviation where liquid fuels are really the only option for the foreseeable future. Our report shows that, with the right safeguards and monitoring, biofuels from waste in particular are well worth pursuing from a sustainability point of view and also provide business opportunities for development,” said Azapagic.

Article by Helen Tunnicliffe

Senior reporter, The Chemical Engineer

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