CVEC demonstrates cob harvesting

By Ryan C. Christiansen
Web exclusive posted Oct. 31, 2008 at 10:07 a.m. CST

Benson, Minn.-based Chippewa Valley Ethanol Company LLLP held the last of three corn cob harvesting demonstrations on Oct. 28 near Holloway, Minn. CVEC held the events to promote cob harvesting among area farmers and demonstrate the equipment that is available for the job. Previous demonstrations were held in Donnelly, Minn., on Oct. 27 and Priam, Minn., on Oct. 15. CVEC plans to use a Frontline BioEnergy gasifier to convert cobs to syngas that will replace natural gas at CVEC's 45 MMgy ethanol plant, according to Gene Fynboh, the harvest coordinator and a board member for the Chippewa Valley Agrafuels Co-op.

Last January, when CVEC requested applications from farmers to participate in the cob harvest, the company received applications offering a total of more than 25,000 acres of corn for the cob harvest, Fynboh said. CVEC selected 5,000 acres from more than a dozen farmers for the harvest. With this year's late harvest, he said it remains to be seen whether 5,000 acres of cobs will be harvested. "If the weather gets late and the farmers get a little nervous about that, we'll probably take some of those acres without the cobs," he added. Fynboh said the purpose of the demonstration was not just to show off the available equipment, but also to test its durability. The goal was to harvest 2,500 acres using the Vermeer Corp. CCX770 Cob Harvester, which is a pull-behind cob collection system, as well as 2,500 acres using the Ceres Ag Residue Recovery System, which mounts directly on to the combine.

Although still a prototype, the Vermeer harvester was operating as well as hoped, collecting between 85 and 90 percent of the cobs from the residue expelled by the combine, said Jay Van Roekel, segment manager for Vermeer. The CCX770 hitches to the back of the combine where it collects the crop residue and separates the cob from the rest of the corn stover. The harvester then blows the stalks, leaves, and husks back on to the ground. Very few cob pieces were observed left behind in its wake.

However, Vermeer needs to consider more than just yield, Van Roekel said. "We want to be sure that we're working well with the combine and not creating any unusual wear and tear," he said, "because it wouldn't be any good if you tear up [the combine] that's towing it." One of the concerned felt by farmers is that they want to collect cobs without impacting the speed and efficiency of the corn grain harvest, Van Roekel added.

According to Van Roekel, this is the first real test for the CCX770, which is also scheduled to be tested and demonstrated Nov. 6 during the Poet LLC Project Liberty Field Day in Emmetsburg, Iowa. Poet's 50 MMgy grain-to-ethanol plant in Emmetsburg is being converted into an integrated corn-to-ethanol and cellulose-to-ethanol biorefinery, which will produce 125 MMgy of ethanol, 25 MMgy from corn cobs.

The final manufacturing specifications for the CCX770 will be determined in December after the harvests, Van Roekel said, adding that Vermeer plans to make the harvester available to early adopters for the fall 2009 harvest.

CVEC hopes to have permits in place to use the cobs in its gasifier this winter. A ton of cobs produces similar British thermal units to a ton of coal, according to Fynboh, however it produces very little ash. "We think a ton of cobs is worth a ton of coal or whatever else you're going to put into [the gasifier]," he said. "But one of the things about using local biomass is that economically, it helps the local community, and that needs to be figured into the value of what is used. Every check that we write to someplace else, that's resources going out of our community."

CVEC currently purchases corn from approximately 112,000 acres of land. "We expect that those same 112,000 acres could provide 75 percent of the energy needs for operating the plant if we use all of the corn cobs," Fynboh said. "It's not an insurmountable task. Twenty-five years ago, you couldn't imagine the pile of corn that we're producing now."