New Corn-to-Ethanol Process Promises Lower Costs, Environmental Benefits

The process 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. The team that developed the technology was led by professor Li-fu Chen and research assistant Qin Xu, both from the Purdue food science department.

"Our process, which we are calling the Chen-Xu Method, not only makes ethanol, but products that are fit for human consumption," said Chen. "This process also produces corn oil, corn fiber, gluten and zein, which is a protein that can be used in the manufacture of plastics so that the containers are good for the environment because they are biodegradable and easily decompose. The containers would actually be edible, although there probably wouldn't be much market for that."

The Purdue Research Foundation has licensed the technology to Bio Processing Technology Inc., which was formed to bring inventions from Chen and Xu to the marketplace.

"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," he noted. "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."

With the Chen-Xu Method, the water input required by wet milling is reduced by 90%, wastewater output is cut by 95%, and electricity use is reduced by 47%. It also meets federal Clean Air Act standards, eliminating costs that other methods incur in meeting environmental regulations, said Chen.

"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," said Chen. "And with proper planning and management, total equipment investment should be less than that of a dry-milling plant."

Funding for the work came from industry donations and one year of support from the Value-Added Grant Program of the Indiana State Department of Agriculture. Chen said the next step for the fledgling company is to commercialize the technology worldwide. The technology was licensed to Bio Processing Technology Inc. through the Office of Technology Commercialization, a division of Purdue Research Foundation.