Reviewed by Lexie CornerDec 9 2024
In a recent study in Green Chemistry, scientists from the King's College London and Brazilian Biorenewables National Laboratory used enzymes to convert fatty acids in cooking oils into alkenes, which are essential building blocks for fuels like gasoline and diesel. The researchers suggest that this renewable fuel, produced from food waste, could help reduce reliance on fossil fuels.
The study presents a new method of producing biofuels from leftover fats, which is 1000 times more efficient than current techniques and as effective as diesel.
Biofuels, which are made from renewable organic materials such as vegetable oil and other plant or animal-derived substances, can be produced from food waste. These fuels can reduce greenhouse gas emissions by up to 94 %, offering a sustainable alternative to fossil fuels in conventional combustion engines, potentially replacing gasoline or diesel.
However, biofuels often burn inefficiently due to their high oxygen content. Despite biofuels derived from fatty acids providing 90 % of the energy produced by diesel, this inefficiency has hindered their widespread adoption. The cost of producing these biofuels is higher than fossil fuels, as more raw materials are required to produce diesel-equivalent fuel.
As a child, I remember canisters of oil sitting outside chip shops, soon to be cut with diesel and put in the back of a car for a long time the smell of grease and questionable legality was the only thing people knew about biofuels. However, they are going to be a vital way that industries like logistics divest away from fossil fuels, and without a significant investment in the technology, countries like the UK are going to get further and further from meeting their emissions targets. What we have created is the chemical equivalent of the fossil fuels we are using every day, meeting all the standards the chip shop fat of yesteryear could not.
Dr. Alex Brogan, Senior Lecturer, Department of Chemistry, King’s College London
The researchers altered an enzyme called P450 decarboxylase to break down fatty acids in food waste and extract the oxygen contained therein to produce a more effective fuel with more active alkene.
The enzyme usually needs water to function, which results in a low alkene yield. To get around this, the altered enzyme was submerged in liquid salt and exposed to UV light while combining with fatty acids to initiate the reaction.
The yield of alkenes produced as a result was significantly higher than what is feasible in water, because of the increased efficiency, less energy, and raw materials needed to produce the fuel, which significantly improves sustainability.
Additionally, the process eliminates the need for traditional catalysts like platinum because the enzyme is a biological catalyst, preventing any environmental harm from mining. The use of harmful substances like hydrogen peroxide to accelerate the reaction is also avoided when UV light is used.
Our (bio)technology enables us to expand into other renewable materials and produce a variety of fuels, including gasoline and kerosene, for the aviation sector. We recognize that much work remains, and are excited to contribute to addressing one of the world’s greatest challenges: climate change.
Dr. Leticia Zanphorlin, Principal Investigator, Brazilian Biorenewables National Laboratory
By developing a method to bypass the P450 family of enzymes' reliance on water, the team aims to apply this technology to improve chemical reactions in various fields, including the more efficient production of pharmaceuticals.
Journal Reference:
Nicholson, J. H., et al. (2025) Enhancing the reactivity of a P450 decarboxylase with ionic liquids. Green Chemistry. doi.org/10.1039/d4gc05292g.