Construction of one of the country’s first commercial-scale cellulosic ethanol plants will begin this fall in the heart of Iowa. The new facility, which will be located adjacent to Lincolnway Energy’s existing corn starch ethanol plant in Nevada, Iowa, will be capable of producing 25 million gallons of cellulosic ethanol per year, using technologies developed by DuPont Industrial Biosciences. This will require approximately 350,000 tons of biomass annually, mostly in the form of corn stover.
Over the last two years, DuPont Industrial Biosciences and corn growers in the area have been testing corn stover collection equipment as well as logistical systems for getting the stover from the field to the biorefinery. In 2010, six growers participated in the Stover Harvest Collection Project. About 70 growers are participating this year. The plan is to scale up production next year to meet what the biorefinery will need when it begins producing cellulosic ethanol in 2014.
Within the testing program, the DuPont group also has been working with DuPont Pioneer and Iowa State University to study the impacts on the soil when stover is collected over the long haul. The collaborators are studying replicated strips and taking soil samples on eight participating farms. Some of these farms apply manure in their operations, while others use other fertilizer programs. What happens under these typical production practices will help researchers define the agronomic benefits and sustainability of stover collection.
The Biosciences group has found that large square bales are easier to stack, transport and store than round bales, reports Andy Heggenstaller, DuPont Pioneer agronomy research manager. Harvest contractors who have participated in the stover project have used large square balers, such as those manufactured by AGCO and Krone. These balers were originally designed for hay, and cornstalks can be pretty hard on them. However, the baler manufacturers have enhanced the durability of the equipment so they are better able to pull cornstalks without malfunctioning, Heggenstaller says.
The large square bales also work well with a self-propelled stacker developed by Stinger Inc., Haven, Kan., which can stack 1,000 to 2,000 large scale bales per day, or 24 to 120 bales per hour. Larry Matlack, president of Stinger, says the stacker can pick up 12 3x4x8-ft. bales at a time in a one-man operation.
Stinger is also developing an automatic load-securing system, which features a hydraulic strapping mechanism that squeezes the bales so that they lie 8 ft. wide across the trailer and that saves the driver from having to strap the load by hand. Depending on transportation regulations, one can carry from 24 to 36 bales per trailer. Stinger also makes cube-line square bale wrappers that further protect bales for storage in the field.
The key to equipment for collecting and transporting stover is how much it can reduce the cost of delivery from the field to the biorefinery. “We’re focused on stover delivered with low dirt and moisture content, and with high bulk density,” Pioneer’s Heggenstaller says.
DuPont Industrial Biosciences will establish contracts with farmers for access to the corn stover in their fields and will essentially manage the harvest, transport and storage of the material. That will include contracting with custom harvesting crews and trucking companies. “We see a large role ahead for custom harvesters,” Heggenstaller says.