Ethanol plants produce billions of gallons of renewable fuels each year. In the process, however, they also produce millions of tons of byproducts. A promising approach to using these byproducts while boosting energy and economic benefits is getting a trial run through a $250,000 investment by the Initiative for Renewable Energy and the Environment, a signature program of the University of Minnesota's Institute on the Environment.
The three-year project, which started on July 1, 2010, is being led by researchers from the Duluth-based Natural Resources Research Institute. Working with several industrial partners, the researchers will construct and assess the commercial potential of an integrated biorefinery that will convert byproducts from ethanol production known as dried distillers grains with solubles (DDGS) to a variety of high-value products, including animal feed, ethanol, biodiesel, jet fuel, pharmaceutical components and replacements for petroleum-based chemicals.
Currently, the average ethanol plant generates three products: CO2, ethanol and DDGS. When applied to the average ethanol plant, the integrated technology tested in this project is expected to increase the number of products the plant can produce to seven, more than doubling the plant's product diversity and increasing its annual profits by $21 million. The four additional products are 1) high-protein distiller's grains, used to make protein-rich livestock feed; 2) "green" diesel, which is diesel fuel derived from renewable sources with the potential to be converted to "green" jet fuel; 3) biodiesel; and 4) zein, used throughout the food, textile and pharmaceutical industries and able to be processed into bioplastic polymers that are employed to make a wide varity of plastic products.
If applied to the entire ethanol industry, the improved capacity is expected to enhance energy efficiency by 15 percent and increase the amount of transportation biofuel produced by 20 percent.
Successful completion of this project will be a crucial step toward large-scale commercialization of an integrated biorefinery. Large-scale application of the technology would position Minnesota to help the U.S. meet its renewable energy needs: Foreign oil imports could potentially be reduced by 1.065 billion gallons annually, and national ethanol production could be increased by 10 percent, adding nearly 1 billion gallons of ethanol to current ethanol production without the environmental stresses related to growing more corn.
Photo: Josh Kohanek