Supplanting petrol

plant-based alternative fuels may be as efficient as petrol, but for now they offer only marginal environmental benefits, according to scientists who have analysed how much energy goes into producing such biofuels, and how much carbon dioxide (co2) they emit as they power vehicles.

A us study that appeared in the January 27 issue of Science (Vol 311, No 5760) claims that corn ethanol is almost on par with petrol