A Purdue University team led by professor Li-fu Chen and research assistant Qin Xu, both from the Purdue food science department, discovered a new method to create ethanol from corn. The method also produces biodegradable byproducts that could be safely eaten.
Existing methods of corn-to-ethanol conversion produce as much as 2.6 gallons of ethanol per bushel. The new Chen-Xu method produces 2.85 gallons for a 9.6% improvement. But this method also reduces energy use in the conversion process and produces less waste.
The Chen-Xu Method produces about 2.85 gallons of ethanol for every bushel of corn processed. That output is slightly higher than current methods, but the same process that creates the ethanol also creates other marketable products. Chen said the method also meets federal Clean Air Act standards, eliminating costs that other methods incur in meeting environmental regulations.
"One of the common methods of manufacturing ethanol, called dry milling, is often the cause of air pollutants by drying and storage of DDG, a byproduct of the process," Chen said. "Another method - wet milling - produces an odor because it requires the input of sulfur dioxide. The Chen-Xu Method eliminates both issues, and the only odor comes from the smell of the corn and yeast fermentation."
Using a machine originally designed to make plastics, the Chen-Xu Method grinds corn kernels and liquefies starch with high temperatures. The water input required by wet milling is reduced by 90 percent, Chen said. Wastewater output is cut by 95 percent, and electricity use is reduced by 47 percent.
"The total operating cost of a Chen-Xu Method ethanol plant should be much less than that of a wet-milling plant, and total equipment investment is less than half," Chen said. "And with proper planning and management, total equipment investment should be less than that of a dry-milling plant."
Lower capital costs, lower operating costs, more ethanol output for with less corn, less electricity, less waste. What's not to like?
Biomass energy technologies are going to keep dropping in cost and increasing in net energy efficiency. Gasoline currently costs more to make than ethanol even after adjusting for the lower energy content of a gallon of ethanol as compared to a gallon of gasoline. The price of oil may drop further. But the cost of converting biomass to ethanol will continue to drop in the coming years.
|Share |||Randall Parker, 2006 September 19 10:05 PM Energy Biomass|