A Tennessee farmer mows switchgrass destined for the Genera Energy demonstration biorefinery in Vonore, TN.
Custom forage harvesters will soon gain a number of new clients if Sam Jackson’s expectations for cellulosic ethanol production are on target.
He’s vice president for feedstock development and supply at Genera Energy, Vonore, TN, where a 250,000-gallon cellulosic ethanol demonstration plant has been operating for two years. Research on corn stover there led to the announcement of a commercial-scale biofinery in Iowa, and Jackson believes current work on switchgrass will lead to a similar facility in Tennessee within two or three years.
That plant, along with the Iowa facility and one or two other expected biorefineries, will open the cellulosic-ethanol floodgates, he predicts.
“Particularly here in the Southeast, I think we’ll see a pretty quick buildout once it gets rolling,” says Jackson, also a University of Tennessee research assistant professor. “Once the first person climbs to the top of the hill and says ‘I’m here,’ it’s not very long before there are others standing around them.”
He sees cellulosic ethanol production as a “huge opportunity for the country from an energy independence and sustainability standpoint, and a huge opportunity for agriculture. This could open some new doors to farmers who have had limited markets or difficulty in producing quality material from lower-quality land.”
Tennessee alone has enough marginal and unused land to supply biomass for 10 biorefineries, generating at least $135 million annually in new farm revenue, according to a University of Tennessee analysis.
The demonstration facility, a partnership between the State of Tennessee, Genera Energy and DuPont Cellulosic Ethanol, has shown that the biofuel can be produced economically, Jackson says. In a short time frame, costs have been reduced by more than 50% in parts of the ethanol production process.
“The demonstration biorefinery proves the technology works and is feasible on a large scale.”
Sixty-one farmers in a nine-county area around Vonore are growing 5,100 acres of switchgrass for bioenergy. They harvest it once a year, from November through February. Some may be hiring custom harvesters, and Jackson figures contract balers and haulers will play a much bigger role when a commercial-size plant is operating.
The farmers are permitted to use their existing hay equipment, so the plant’s stackyard has round and square bales in a variety of sizes. When a bigger plant comes on line, though, a specific bale shape, size and density will be required.
“I think, initially, it’s going to be large square bales, and then hopefully we’ll move to bigger and better systems beyond that,” says Jackson.
Genera is evaluating an alternative to baling in which dry switchgrass is chopped with a forage harvester and delivered in bulk. Although hauling costs would be high, the method would eliminate much of the preprocessing now done at the plant.
In another research project, about 1,200 tons of chopped material has been run through a garbage baler. Built in Europe, the machine makes 5 x 6’, net- and plastic-wrapped round bales weighing more than a ton each.
That packaging method is seen as a way to conserve space while protecting biomass during long-term storage. The annual rainfall is 50-60” in eastern Tennessee, and biomass must be kept dry. Other storage techniques are also being evaluated.
The next step is for DuPont Cellulosic Ethanol to build a commercial-scale plant in Tennessee. The company plans to start construction on its Nevada, IA, ethanol-from-stover plant later this year, and Jackson sees that announcement as proof its leaders know cellulosic ethanol can be profitable.
“They’re building it because they believe in it,” he says.
“DuPont has publicly stated its commitment to build an energy-crop-based plant here in Tennessee,” he adds. “I think we’re getting close.”