While ethanol made from fermented corn grain can boost the octane and reduce the tailpipe emissions of gasoline, it's expensive, costing about five cents a liter more than gas. A Canadian biotech company, however, says that next year it will begin building the world's first facility to mass-produce ethanol, not just from grain, but from a far more abundant source: agricultural waste, such as cornstalks, cobs, and leaves. That could help bring ethanol's price closer to that of gasoline.

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