Waste not, want not

plans to build a commercial-scale plant to produce ethanol from crop waste by 2008. It will use a process developed by Canadian enzymes specialist

, with whom Shell has a technology joint venture.

Lionel Clarke, Shell's head of strategic research for fuels technology, said the company is already the largest distributor of fuels derived from biomass. The technology has two strands: production of diesel from woodchips, as a fuel in its own right and for blending with refinery diesel; and the production of ethanol as a petrol additive.

Blending ethanol into petrol reduces carbon dioxide emissions, as the CO2 released is offset by the amount absorbed by plants. Under the UK's Kyoto Protocol commitments, all fuel companies will have to blend five per cent biofuel into petrol and diesel by 2010.

Iogen's technology is concerned with making ethanol. Producing ethanol from vegetable matter is not new; fermenting grain to produce alcohol then distilling it was one of the first chemical technologies. But making alcohol from the waste — the stalks and leaves of grain crops rather than the grain — is a different matter.