The renewable-fuel standard released in February by America's Environmental Protection Agency (EPA) paints an ambitious picture of biofuels' future. It wants the amount of the stuff used as transport fuel to climb from 13 billion gallons (49 billion litres) in 2010 to 36 billion gallons in 2022, requiring by far the largest part of that increase to come from various advanced biofuels, rather than ethanol made from corn (maize). But although the future looks exciting, the present is rather grim. The epa has been forced to slash its 2010 mandate for the most widely touted of the non-corn biofuels, cellulosic ethanol, from loom gallons to just 6.5m, less than a thousandth of the 11 billion gallons produced from corn in 2009.
展开▼
