Dirk Lammers  /  AP
Workers at a lab in Sioux Falls, S.D., add ground corn stover, water and enzymes to a fermenter on April 24. They work for Poet, a company that produces about a billion gallons of corn-based ethanol each year. It now has plans to produce cellulosic ethanol from corn cobs.
updated 11/13/2007 12:41:28 PM ET 2007-11-13T17:41:28

Piles of corn cobs on Darrin Ihnen's family farm would have been considered field waste not too long ago. Now they represent potential energy.

Poet, a Sioux Falls-based company that has been making ethanol from corn for more than 20 years, is working with Ihnen and several farm equipment manufacturers to develop ways to harvest, store and transport cobs that could one day join kernels as an alternative fuel source.

"Cobs surround our facilities," said Jeff Broin, Poet's president and chief executive officer. "It's a natural feedstock for us."

Poet plans to expand its plant in Emmetsburg, Iowa, to produce 125 million gallons of ethanol per year — 25 percent from corn cobs and fiber.

Farmers typically leave cobs and stalks behind in the fields, but cobs — which are the densest part of corn — can be removed without causing soil erosion or stealing soil nutrients.

"To us, a cob is a waste product," Ihnen said. "It's something that stays in the ground for two or three years and decays."

Buying cobs
It's too early to determine what Poet will pay farmers for their cobs, but the company estimates it will be somewhere between $30 and $60 a ton.

Poet will need about 275,000 acres of cobs to supply its expanded Emmetsburg plant, which is scheduled to begin operation in 2011. The company is harvesting 4,000 acres on Ihnen's farm using several methods to gather the cobs.

One method uses a John Deere 9860 STS Combine modified to collect a mix of kernels and cobs. The mix is then fed into a separator built by Salem-based Feterl Manufacturing Corp., which sorts the kernels from the cobs.

Randy Bauer, Feterl's president and chief executive officer, said the company spent about five months developing the prototype and is now ready to go into production design.

In addition to ethanol production, there's a huge cottage industry for corn cobs, which are used as an organic abrasive on metal, plastic and wood, Bauer said.

A second method uses a standard combine hitched with a Cob Caddy, an invention of Vernon Flamme of North Bend, Neb., which collects the cobs as they exit with the stalks and husks.

The kernels stay in the combine, the husks are blown back into the field and the cobs fall into the caddy.

Federal funding
The U.S. Department of Energy earlier this year awarded $385 million to six companies hoping to build the nation's first large biomass-to-fuel plants. Poet, one of the six, is slated to receive up to $80 million in grant money, which is part of the Bush administration's goal of making cellulosic ethanol competitive by 2012.

Poet officials said the company's cellulosic ethanol research should allow it to squeeze 27 percent more fuel from each acre of the crop.

With the September grand opening of its Portland, Ind., biorefinery, Poet now has the capacity to produce more corn-based ethanol than any of its competitors, including agriculture giant Archer Daniels Midland Co., according to the Renewable Fuels Association.

Poet's 21 plants can pump out 1.1 billion gallons of the alternative fuel, and additional biorefineries under construction or development will eventually add 375 million gallons of capacity.

ADM has an annual capacity of 1.07 billion gallons with facilities under construction or development that will add 550 million gallons annually, according to the RFA.

Copyright 2007 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

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