Liquid alkane fuel can be produced from a by-product of biomass processing, thanks to researchers from the University of Wisconsin, Madison, US.

As the world's reserves of petroleum dwindle, finding alternative sources of fuel is becoming increasingly important. Producing liquid alkanes from bio sources is attractive because the use of biomass produces less carbon dioxide, and so it impacts less on global warming. Liquid alkanes have advantages over other biofuels, such as ethanol, for use as transportation fuels because they can be used in existing engines and distributed using infrastructure already in place.

James Dumesic and co-workers devised a system that involves the integration of two processes. The first process is the production of synthesis gas, a mixture of carbon monoxide and hydrogen, from glycerol. The second is a Fischer-Tropsch synthesis, where the synthesis gas is converted to hydrocarbons. Both processes are catalytic, with the first being endothermic and the second exothermic, and the system operates at low temperature and moderate pressure. In integrating the two processes Dumesic's team found that they could feed the synthesis gas produced in the first process directly into the second without purification.

They also found that in addition to the liquid alkanes produced, the gaseous and aqueous phase by-products include methanol and ethanol, useful in their own right. Dumesic said that this gives 'the potential to improve the economics of green Fischer-Tropsch synthesis by reducing capital costs and increasing thermal efficiency'.

Madelaine Chapman