Vinod Sreeharsha – IEE Spectrum, 01/02/2013
Later this year, northeastern Brazil will host one of the most ambitious biofuel experiments ever. There, in the small town of São Miguel dos Campos, surrounded by sprawling sugarcane fields, a commercial-scale ethanol plant is expected to start operating in December. Unlike the nearby ethanol plants, which use sugarcane as feedstock, this new facility will consume the leftovers of those plants—bagasse and straw—to produce a holy grail of biofuel: cellulosic ethanol.
Ethanol produced from corn has gotten a bad reputation in recent years. Turning food crops into fuel might help drivers fill up their tanks, but it also raises food prices. What’s more, studies have shown that production of corn-based ethanol actually increases carbon emissions rather than reducing them. Because cellulosic ethanol is made from agricultural waste and nonfood crops, it has none of those drawbacks.
The prospect of transforming cheap raw materials like sugarcane bagasse, switchgrass, wood chips, wheat straw, and corn stover into fuel has led to a worldwide race for technologies that can make cellulosic ethanol commercially practical. But success has eluded big companies and start-ups alike. It costs more to make ethanol from cellulose than from corn or sugarcane because of the extra equipment, chemicals, and steps involved.