On Friday, January 29, DuPont Danisco Cellulosic Ethanol LLC (DDCE), the University of Tennessee and Genera Energy LLC hosted a grand opening for one of the country’s first cellulosic ethanol demonstration plants. Located in Vonore, TN, the facility will have the capacity to produce 250,000 gallons of ethanol from corn cobs and switchgrass. It is expected to begin producing ethanol on a commercial-scale basis in 2012 using 100 percent switchgrass feedstock.
Over the last three years, the University of Tennessee (UT) has implemented a switchgrass increase program. In the first two years, the project was funded by the state of Tennessee and has involved publicly-available contracts. Farmers that signed the three-year contract have been paid $450 per acre per year for their switchgrass. The program provides farmers the seed as well as technical expertise from UT’s Agricultural Extension Service.
Switchgrass is a new crop for farmers to learn, says Kelly Tiller, president and CEO, Genera Energy. (Genera Energy is a for profit company wholly owned by the University of Tennessee Research Foundation.) Planting depth, for example, is extremely important with switchgrass so agronomists have been helping farmers calibrate their drills. The small switchgrass seeds need to be planted between one-quarter and one-half inch deep.
Since this is not an irrigated crop, taking advantage of planting dates to capitalize on available moisture is also important, Tiller says. It is difficult to control grassy weeds in switchgrass and many of the chemical controls are not currently labeled for switchgrass. Genera Energy is working with major crop protection companies to get products registered for the crop, Tiller says. “With help from the UT Ag Extension Service, however, we’ve had better than a 90 percent success rate with switchgrass establishment,” Tiller says.
This year, Genera Energy is getting involved in the contracting and plans to move contracts from an acreage-based payment to a payment based on yield. Genera Energy also is offering some contracts for on-farm storage of harvested switchgrass.
Since its inception, the project has awarded contracts to farmers within a 50-mile radius of the demonstration plant. In 2008, it contracted 723 acres. This expanded to 2,000 acres in 2009, with about 40 farmers participating. In 2010, the project is expected to expand to 7,000 acres, with between 80 and 90 farmers participating. The switchgrass program has generated a lot of excitement among area farmers and several of them have increased their acreage for 2010, Tiller says.
“We’re focused on keeping supply and demand in balance,” Tiller adds. “We’re interested in moving to commercial scale ethanol production, but we’re looking at using the feedstock for co-firing energy plants for the nearer term. This will allow us to help build supplies so the entire industry can move forward.”
As participating farmers’ contracts expire, the farmers can choose to become members of the Tennessee Biomass Supply Cooperative (TBSC). Organized last fall as a “New Generation Co-op,” TBSC will coordinate production and processing operations and deliver switchgrass feedstock to end users, such as utilities that would use it to co-firing their energy plants.
Farmers involved in the project are using existing production equipment, such as mower/conditioners and round balers for harvest. They move the bales to the edge of their fields where Genera Energy picks them up with a semi-tractor trailer and then moves the feedstock either to a storage location or the biorefinery. The harvest equipment is not necessarily tailored for switchgrass, with its tough stems, so Genera Energy has been working with equipment manufacturers (including AGCO, CNH, John Deere and Vermeer) to better manage the crop.
Genera also has received a grant from the Department of Energy to develop a system whereby switchgrass can be chopped in the field and brought to field edge. There, Genera would pack it in trucks and take it to be stored in bulk. Genera Energy has modified a cotton module to reduce transportation and storage costs.
Up to one-third of a switchgrass crop is made up of lignin, which is not used in the production of cellulosic ethanol. This is separated out of the process, and can be used in the boiler to provide process heat and steam at the biorefinery. In the future, some of the lignin could be used in the production of carbon fiber and several chemical platforms which would replace petroleum-based chemical platforms, Tiller says.