Researches Improved Ethanol Yield from Corn
By Ben Hardin
October 25, 1996
PEORIA, Ill., Oct. 25--Cars
in the 21st century could run on ethanol fermented from fiber-rich crop
residues like wheat straw or corn stalks instead of corn.
Agriculture Department scientists are moving
in that direction with research that seeks to squeeze more ethanol from corn
using the grain's fiber.
"This research delivers on the Clinton Administration's commitment to
the continued growth and development of the domestic ethanol industry,"
said Agriculture Secretary Dan Glickman. "Technological innovations in
corn production and ethanol conversion will continue to improve ethanol yield
per bushel and per acre."
Microbiologist Rodney J. Bothast of USDA's Agricultural Research Service heads a research team
that's now scaling up a process for converting grain fiber into sugars.
Genetically engineered microbes convert these sugars into ethanol.
Modern ethanol plants ferment grain's starches and sugars to produce 2.5
gallons of ethanol per bushel of corn. Bothast's research team, based at the
ARS National Center for Agricultural
Utilization Research here, aims to coax an extra three-tenths of a gallon
of ethanol from every bushel of corn kernels.
"This technology could be applied to converting cellulose from other
crops creating additional income and market opportunities for farmers,"
said Glickman. "USDA analysis confirms that expanding ethanol production
increases farm income and creates jobs in rural America."
In 1994, about 1.3 billion gallons of fuel ethanol were produced from corn.
More than 60 percent came from wet milling, in which the corn is soaked in
water before grinding it. Ethanol has traditionally been produced by fermenting
the corn's starchy endosperm--the storage tissue in the seed that
"feeds" the corn plant during germination. Currently the leftover
fiber is mixed with water and fermentation residues, then dried and fed to
"However, if this fiber were processed into ethanol, the increased
efficiency and potential reductions in cost for a corn wet milling facility
could significantly enhance net returns," says Robert B. Hespell,
microbiologist and project leader for ethanol research in Bothast's
Fermentation Biochemistry Research
According to USDA's Economic Research
Service, the ethanol energy now produced from each bushel of corn is more
than 25 percent greater than the amount of energy used to grow and harvest the
corn and distill it into ethanol, thanks to today's higher corn yields, more
energy-efficient fertilizer production and improved distillation technology.
Recent research to further improve ethanol production is described in the
October issue of Agricultural Research
magazine, the monthly publication of the Agricultural Research Service.
Scientific contact: Rodney J. Bothast, National Center for
Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria,
Ill. 61604. Telephone: (309) 681-6566