WASHINGTON—President Bush's hope to replace up to 15 percent of the gasoline Americans use with ethanol made from wood chips, cornstalks, grass, straw and the like will require scientific, technical and economic breakthroughs.
Government and private laboratories are experimenting with techniques to extract ethanol more easily from plant materials composed of tough cellulose fibers, such as switch grass, but for now Bush's ambitions are far from reality.
"The private sector continues to work furiously, both on their own and in partnership with government," said John Mizroch, an official in the Department of Energy's Office of Renewable Energy. "But there have been no major breakthroughs."
Demonstrating his interest, Bush toured a DuPont greenhouse Wednesday in Wilmington, Del.
"Because of the research you're doing here with some of their taxpayer dollars, that switch grass—that can be grown all across America—can end up being made into fuel that powers their automobiles," he told DuPont microbiologist Armando Byrne.
Bush's visit came the morning after his State of the Union address, in which he pledged to increase the supply of renewable fuels to 35 billion gallons by 2017, five times more than is expected this year. Part of that increase would be ethanol made from cellulose.
The president said he'd ask Congress for $2 billion in loans to build cellulose ethanol refineries over the next 10 years. He'll also need to persuade Congress to extend a 51-cent-per-gallon ethanol tax credit that's set to expire in 2010. The extension would cost the Treasury $17.8 billion if production goals are met.
Despite Bush's endorsement, there are more problems with so-called cellulosic ethanol than with corn-based ethanol.
Corn-to-ethanol plants are booming across the Midwest. Last year, 5.5 billion gallons of corn-based ethanol were used as additives to gasoline, and corn growers expect to churn out at least 7.5 billion gallons this year. About 40 percent of U.S. gasoline is blended with ethanol.
Last year's ethanol production reduced greenhouse-gas emissions—a major cause of global warming—by more than 1 million tons, according to Bob Dinneen, the president of the Renewable Fuels Association. "That's the equivalent of taking 1.2 million vehicles off the road," Dinneen said.
However, the nation is bumping up against the limit of how much corn it can afford to use for fuel without driving up prices for meat, grain and sweeteners.
Farmland best suited for corn-growing is limited and far from huge population centers, requiring expensive transport for ethanol. The fuel is too corrosive for pipelines, so it must be carried by truck or rail. Cellulose ethanol refineries could be closer to users.
"Absolutely, cellulose technology will be necessary to move beyond the limits of grain-based ethanol," Dinneen said.
To reach Bush's goal, more ethanol will have to come from cellulose than from corn, according to Mizroch.
"It will have to be 2-to-1 cellular," Mizroch said.
Unfortunately, making ethanol from cellulose is complex and costly. Corn-based ethanol is much easier.
The kernels in an ear of corn contain a simple sugar that humans have known how to ferment into alcohol for thousands of years. Ethanol is a form of alcohol, also known as grain alcohol or ethyl alcohol.
Transforming cellulose into ethanol requires a number of processes. First, the fibers that stiffen cellulose must be shredded or steeped in acid to soften them. Then, the cellulose must be converted into sugar by using enzymes that are still being perfected. Finally, the sugar has to be fermented into ethanol.
Government and private laboratories are experimenting with bacteria, yeast and even termites to increase the yield and lower the cost of these steps.
Mizroch said the Energy Department expected that the first full-scale commercial cellulosic ethanol plant would be producing 15 million gallons of fuel a year by 2012.
"Private-sector efforts on cellulosic development are exploding," said Nathanael Greene, an energy analyst at the Natural Resources Defense Council, a research center in New York.
The hype is such that Greene is worried about "a gold-rush mentality." He recalled premature bursts of enthusiasm for wind power in the 1980s, which enticed "shoddy investors" and "set the industry back 10 years."
A number of pilot projects are planned or under way. Examples:
_Mascoma Corp., a start-up in Cambridge, Mass., has received $20 million from New York and $30 million from venture capitalists to build a demonstration plant to make 2 million gallons of ethanol a year from wood chips and municipal waste.
_Iogen, a Canadian biotechnology company, hopes to break ground this year on a $300 million plant that would convert wheat, oats and barley straw into ethanol. The cost is five times what it would be for a conventional, corn-fed plant of similar size.
_The Broin Cos., based in Sioux Falls, S.D., plans to convert its corn-to-ethanol plant in Emmetsburg, Iowa, to use cornstalks and leaves—not kernels—to make 125 million gallons of fuel a year.
(c) 2007, McClatchy-Tribune Information Services.
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