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Too much ethanol?
One of the biggest challenges, short- and long-term, will be to find a market for all the ethanol produced. Like other Midwestern states, Indiana will see increased production, with six operating ethanol plants, six under construction and some 25 more under consideration, Hurt says. The national production capacity, which surpassed 7 billion gallons last year, is expected to reach 11 billion gallons by July and approach 13 billion by year’s end.
But 12 billion gallons is the maximum that can be sold domestically in 2008, Tyner predicts. That’s because ethanol may only be blended into regular gasoline at 10 percent, known as “E10 fuel,” and gasoline blenders are nowhere near being able to blend the 140 billion gallons of gasoline consumed annually. Selling more E85, an 85-percent ethanol fuel used by flex-fuel vehicles, is an obvious choice—except it is sold at only 1,530 stations nationwide, less than 1 percent of the nation’s total stations, Dooley explains.
“It’s a chicken-and-egg situation,” Tyner says. “People are unwilling to get flex-fuel vehicles because there are so few stations; companies are unwilling to build more stations because there are few vehicles.”
Moreover, E85 pumps are expensive to install; gas stations need to charge an extra 5 to 7 cents per gallon to recover costs, according to a U.S. Department of Energy report.
“It might not seem like much, but consumers are fickle—everything equal, we’d choose the cheaper gas, even if it’s only a few cents less per gallon,” Dooley says.
Toward sustainability
Besides being affordable, biofuels also must contribute to America’s energy independence, reduce greenhouse gases and be maximally sustainable—a tall order, to say the least.
Ideally, biofuels trump fossil fuels because they can be grown locally and, upon combustion, release only carbon captured during their brief lifetime. Conversely, fossil fuels—contained in some politically volatile regions—release carbon sequestered for eons, increasing net levels of atmospheric carbon dioxide, the heat-trapping gas behind climate change.
Past a certain point, however, sustainability becomes subjective and difficult to define. For example, is it more important to reduce runoff or carbon emissions? The short answer: It depends. Purdue researchers, including Tyner, agricultural and biological engineering professor Bernie Engel, and agronomy professors Sylvie Brouder, Ron Turco, and Jeff Volenec, are among the first to tackle such difficult questions. They seek, among other things, to establish guidelines for quantifying biofuels’ environmental impacts and to bridge the gap between scientists, policymakers and farmers.
When compared with grassland, for example, corn acreage requires relatively high levels of nutrients and pesticides. “Corn is leaky,” as agronomy professor Eileen Kladivko puts it. Kladivko and other Purdue researchers develop practices to mitigate such runoff and drainage. Her work has shown that planting winter cover crops like wheat or rye after fall harvest can reduce nutrient escape. Agronomy professor Tony Vyn has shown that no-till practices limit soil erosion and greenhouse gas emissions; unfortunately, the continuous corn cultivation encouraged by growing ethanol production usually coincides with intensified tillage.
Another biofuel, soy biodiesel, requires fewer agricultural inputs than corn and is more efficient but less economical due to high non-energy demands. “People can’t afford to convert $4.50 soybean oil to $3.50 diesel,” Tyner says, referring to the commodity’s prices as of early 2008.
Candidate crops like grasses and trees are likely to have environmental advantages over traditional row crops, although even these will likely require fertilizer and other inputs to be economically viable. Purdue researchers work to quantify inputs necessary for optimizing yields of such crops, so as to reduce unintended consequences of the shift toward biofuels.
The road ahead
Active research on solid biofuels and cellulosic ethanol offers clues to biofuel’s future. Environmental engineer Larry Nies points to a quote by pioneering physicist Niels Bohr, “‘Prediction is very difficult, especially if it’s about the future.’ It’s quite possible that in 25 years, our cars will run on something we haven’t yet considered,” Nies says.
Other potential biofuels include synthetic gas, or syngas, green diesel from grass or vegetable oils, and even algae-derived fuels. New pyrolitic processes may also be able to create gasoline-like fuels from biomass.
Though the future is uncertain, biofuels do have potential to become a major part of an overall energy solution, and Purdue researchers are among the leaders in biofuel science and industry who guide the path toward a more sustainable future.
It’s just a matter of finding the right bridge,” Tyner says.
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