Fungal production

Growing a fungus in some of the leftovers from ethanol production can clean up and improve the dry-grind ethanol production process, according to a team of researchers from Iowa State University and the University of Hawaii.

'The process could change ethanol production in dry-grind plants so much that energy costs can be reduced by as much as one-third,' said Hans van Leeuwen, an Iowa State professor of civil, construction and environmental engineering.

Van Leeuwen and the other researchers developing the technology recently won the 2008 Grand Prize for University Research from the American Academy of Environmental Engineers for the project.

The dry-grind ethanol production process itself grinds corn kernels and adds water and enzymes. The enzymes break the starches into sugars. The sugars are fermented with yeasts to produce ethanol.

The fuel is recovered by distillation, but there are about six gallons of leftovers for every gallon of fuel that's produced. Those leftovers, known as stillage, contain solids and other organic material. Most of the solids are removed by centrifugation and dried into distillers dried grains that are sold as livestock feed, primarily for cattle.