We're still a long way from making cars that can use household garbage for fuel. However, there may be waste products that allow for ethanol production without compromising corn use in food someday.
Scientists at the leading edge of ethanol research are investigating ways to make the fuel from biomass, organic by-products that might normally be considered useless.
This so-called cellulosic ethanol can be made from wheat and rice straw, switchgrass, paper pulp, and agricultural waste products such as corn cobs, citrus, algae and corn stover. (Stover is the name for leaves and stalks left over after corn is harvested.)
Environmentalists knock ethanol because they say it puts a misplaced emphasis on growing corn for fuel rather than food. They also say it does little to curb harmful atmospheric emissions, since fossil fuels must be burned to process ethanol.
But cellulosic ethanol, if fully developed, could alleviate those concerns. Proponents of cellulosic ethanol say it holds twice the energy potential of corn-based or sugar-based ethanol. That means less land would have to be devoted to harvesting crops for fuel. Furthermore, making and using cellulosic ethanol creates far fewer greenhouse gas emissions than corn-based ethanol. Whereas standard ethanol reduces harmful emissions by 20 to 30 percent compared to gasoline, cellulose-based ethanol cuts emissions by 80 percent [source: Energy Information Administration]. By 2008, a handful of companies, including Western Biomass Energy L.L.C. and Iogen Corp., had set up facilities to produce cellulosic ethanol, with several more announcing plans to follow suit [source: Fehrenbacher].
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