How do second-generation biofuels work?

You're looking at a field of miscanthus, a key member of the second generation of biofuels that's helping to shift the biofuel focus away from corn. Want to learn more? Check out these alternative fuel vehicle pictures.
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At first glance, the fields of miscanthus that blanket Sampson County, N.C., seem of little importance. Standing 4 feet (1.21 meters) taller than a basketball hoop, miscanthus is a giant, spiky, inedible -- and some would say useless -- grass. Yet, in the view of others, these oversized blades might one day be as valuable as gold, or at least a tank of gasoline. A company called Chemtex plans to build a $170 million refinery in Sampson County that will convert 20 million tons of miscanthus and other grasses into ethanol each year [source: Ramsey].

For years, politicians, journalists and scientists have advocated turning plants into ethanol and biodiesel to decrease the world's consumption of fossil fuels, especially crude oil. Biofuel burns cleaner than fossil fuels, releasing fewer pollutants and greenhouse gases, including carbon dioxide, into the atmosphere.

Much of the world's biofuels come from food crops such as wheat, corn, soybeans and sugarcane. The energy produced by these plants is known as a "first-generation" biofuel. As it turns out, these biofuel pioneers don't hold the promise they once did. For one thing, some first-generation biofuel crops, especially corn, compete with food crops for land and water. The U.S. Department of Agriculture says that refineries that develop ethanol from corn consume roughly 40 percent of the maize crop each year [source: Blas]. In 2009, 25 percent of all U.S. corn and grain crops went not into producing food, but into producing biofuel [source: Vidal].

Such crop consumption can create many problems, including higher food prices and deforestation. In addition, the costs of converting and using food crops as a source of fuel can be pricey. That's because refineries can only use small parts of the plant for the biofuel production, such as its oil, sugar and starch content. Such inefficiency makes first-generation biofuels less environmentally pleasing. Moreover, experts now believe that biofuels will never entirely replace crude oil as the energy source of choice. In short, biofuel production is inefficient, and in many respects, environmentally and economically unsound [sources: World Bank; Science Daily].

But the future of biofuel as an alternative source of energy might not be as bleak as once thought. Thanks to miscanthus grass and other "second-generation" biofuel crops, the potential to lessen the world's dependence on foreign oil has never been greater.