Cellulosic ethanol pilot plant: UT/DuPont

DuPont and the University of Tennessee have announced plans to build a new cellulosic ethanol pilot plant and research facility that could help provide the best of both worlds for the renewable fuel.

The pilot plant, which will be located 30 minutes from the University of Tennessee campus in Knoxville, could be one of the first steps in shifting ethanol production from corn to less demand-intensive feedstocks such as corn cobs and switchgrass.

“We believe this project will make Tennessee the focal point for the development of the cellulosic ethanol process,” said University of Tennessee President John Peterson, speaking at a breakfast at the 25th annual Milan No-Till Field Day the day after Tennessee Gov. Phil Bredesen announced the agreement in Nashville.

“When we first talked to the governor about this project, he was skeptical. But we were able to show DuPont that we have already made tremendous strides in laying the groundwork for producing ethanol from non-grain materials.”

Ethanol critics, including the Grocery Manufacturers Association and officials with the Oil Petroleum Exporting Countries (OPEC), have complained that the increasing demand for corn for ethanol production is responsible for “skyrocketing” food prices.

Renewable fuel supporters have countered that corn would eventually be replaced by non-grain materials as the primary feedstock for ethanol, but the development of a commercially viable cellulosic ethanol manufacturing procress has been slow. The DuPont-University of Tennessee partnership promises to produce ethanol from biomass and reduce the ethanol demand for corn.

“With food and gas prices surging at double-digit rates, there is an imperative for sustainable biofuels technologies,” said DuPont Chairman and CEO Charles O. Holliday Jr., in a press release. “This joint venture addresses this issue head on.”

Holliday was referring to an agreement between DuPont and Genencor, a division of Danisco A/S, a Danish company, to form DuPont Danisco Cellulosic Ethanol LLC. DuPont Danisco and the University of Tennessee will build the pilot cellulosic ethanol plant.

The plant, which will be located in Vonore, Tenn., about 35 miles from Knoxville, is expected to produce up to 250,000 gallons of ethanol annually. The plant is expected to be operational by the fall of 2009.

Some farmers attending the Milan Field Day expressed disappointment that the plant will be located in the eastern portion of the state or too far for them to ship baled switchgrass economically.

Peterson said university officials expect the pilot plant to be the first of at least 10 cellulosic production facilities that will be built across Tennessee, providing new cropping opportunities for the state’s farmers.

“This is a new enterprise that doesn’t replace anything else we do in the state,” he said. “DuPont has been working on using corn cobs as a feedstock in its cellulosic ethanol research, but they say switchgrass is as close to corn cobs as anything else they’ve worked on.”

Vonore, Tenn., was selected as the site of the pilot plant and process development unit because it is a 30-minute drive from the University of Tennessee campus and the Oak Ridge National Laboratory, which has also been working on development of a cellulosic ethanol process.

“There’s not any aspect of the cellulosic ethanol process that we won’t cover in this effort,” said Peterson, referring to the University of Tennessee’s participation. “It will touch nearly every department in the university system.”

Farmers in Henry County in west Tennessee have been growing switchgrass and shipping it to a coal-fired electricity-generating plant in Gadsden, Ala., under a grant from the Oak Ridge National Laboratory. That project convinced researchers that the switchgrass should be grown within 50 miles of the cellulosic ethanol manufacturing plant.

As a result, the university has contracted with 16 farms in a 50-mile radius of the Vonore location to produce switchgrass. The farmers, who planted 723 acres of switchgrass last spring, agree to share cost input and production records with University of Tennessee researchers.

Although they’ve been working with other materials, DuPont Danisco managers indicated they have no qualms about using switchgrass in their new cellulosic ethanol technology.

“The high cellulosic content of switchgrass makes it an optimal feedstock for ethanol production,” said John Pierce, technology leader for DuPont Danisco. “Its yield today makes it more than competitive with other biomass sources, and it has the potential to produce more than 1,000 gallons of ethanol per acre in the future.

“The joint venture is now targeting the two optimal biomass feedstocks in the United States, and we are ready to take our technology to the next level of commercial activity.”

In 2007, Bredesen proposed and the Tennessee legislature set aside $40.7 million toward the construction of a pilot biorefinery. Those funds will be combined with a substantial investment from DuPont Danisco to construct the pilot plant and research facility.

DuPont said it expects to invest $140 million in corn stover and sugarcane bagasse research along with the Tennessee pilot plant and research facility over the next three years.

The switchgrass plantings, which range from 15 to 136 acres, are expected to mature in three years. Genera Energy LLC, the corporation set up by the University of Tennessee, to manage the project, has guaranteed the farmers $450 per acre for growing the switchgrass.

The pilot plant will initially process western Tennessee corncobs to ethanol and then will optimize its technology for switchgrass to ethanol conversion, according to University of Tennessee officials.

One of the few groups to be disappointed by the July 23 announcement was Mascoma Corp. of Boston, a company that had received a $26 million grant from the U.S. Department of Energy to work with the University of Tennessee on cellulosic ethanol processing.

Peterson was philosophical about the break-up with Mascoma. “You always want to go home from the dance with the person you wanted to, right?” he said. “DuPont is the partner we want to be with.”

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