Field Demonstrations Yield Corn Cobs for Ethanol Production
by Bill Zahren
For years the only value assigned to the humble corncob was as fuel for pot-bellied stoves or perhaps objects for farm kids to throw at brothers and sisters.
Today the lowly cob is getting rock-star attention in some circles, both for its ability to provide heat for the ethanol distillation process and for potential use in chasing American energy’s dream of cellulosic ethanol.
Gas from corncobs
Gene Fynboh, who farmed 1000 acres near Brandon, Minnesota until his son took over recently, serves as a member of the board of directors at the Chippewa Valley Ethanol Company (CVEC) in Benson, Minnesota. The plant has partnered with Frontline BioEnergy in Ames, Iowa to develop biomass gasification technology.
By gasifying biomass – essentially using heat, pressure, and chemical reactions to break solids like wood chips and corncobs into their chemical components and then collecting the resulting combustible gas – CVEC hopes to replace more than 90 percent of the natural gas used its ethanol process.
Ethanol from corncobs
While farmers have always known corncobs had heat potential, they’re also packed with carbohydrate. That’s made the corncob a key player in the quest to make commercially viable cellulosic ethanol.
POET, an ethanol production company based in Sioux Falls, South Dakota is in the midst adding cellulosic ethanol capability to its Emmetsburg, Iowa plant as part of the company’s $200 million Project Liberty in partnership with the U.S. Department of Energy.
“Cobs are literally a waste product today,” said Jim Sturdevant, Director of Project Liberty, who estimates there are enough corncobs on American farms to make 5 billion gallons of ethanol a year. “They have very low nutrient value (to the soil). Farmers have indicated they are comfortable with cob removal. We’re taking a biomass waste product that has no value today and bringing a whole new revenue stream to farmers. So we believe this is a win, win, win .”
Show and tell
The case for corncobs – whether for gasification or distillation – sounds great on paper, but notoriously practical farmers know you can’t cash theories and computer models at the bank or use them to buy groceries. That’s why CVEC and POET held separate field days in late October and early November.
During the demonstrations, more than a dozen equipment manufactures had their cob-collecting machines in action or on display. Farmers near the CVEC plant saw equipment from Vermeer Manufacturing and the Ceres Ag Residue Recovery System in use on about 3500 acres. POET’s field demonstration got rained out, but 750 people showed up nonetheless to view prototypes from Vermeer, Case IH, Redekop, John Deere, and Demco, among others.
“The ultimate object was to energize the farmer base in and around Emmetsburg for recognizing and appreciating that cob harvesting can be an exciting new revenue stream for their farm business,” Sturdevant said. “Clearly this is also an opportunity to help our nation’s energy campaign, participate in one of the first cellulosic ethanol processes in the world, and be a part of an effort to reduce our dependency on foreign oil.”
Working out the ROI
Officials at CVEC and POET said participants in the demonstration days were excited about the possibilities and full of questions, but like any business, it kept coming back to return on investment.
“There’s a lot we are all trying to understand,” said Jay Van Roekel, a segment manager for Vermeer who is involved developing their cob collection machinery. “We all want to understand the process. Where do the cobs get stored? How do they get them from storage to the plant? Who is responsible for that? How much will Chippewa Valley and POET and others will pay per ton? How much a farmer has invested in the harvest per ton and just what the financial picture is. That’s all being determined yet, and we’re all very eager to work through those numbers to understand the attractiveness for the farmer to go the extra step (of harvesting cobs).”
Fynboh said his peers at the CVEC demonstrations seemed very excited about the possibilities.
“There was a lot of interest out there,” Fynboh said. “You could really see the people who caught the vision of what was going on and what the potential value of gathering cobs could be to the rural economy.”
Bullish on cobs
Early estimates put the value of corncobs at between $30 and $60 per ton, which could mean $25,000 to $75,000 in revenue per farm, according to POET. POET and CVEC are both gearing up for a larger-scale commercial cob harvest in 2009.
Fynboh said most are bullish on the possibilities.
“It’s another resource that we haven’t been using out there,” said Fynboh, who was one of the farmers who helped launch CVEC in 1992. “As far as we can tell cobs haven’t been all that valuable of a nutrient in the soil for crop production. It’s a source of energy. It’s in our own backyard. It belongs to us. Rather than going someplace else to get energy to run the plant we can do it in our own community. It’s another resource we have, and if we don’t use our resources for our own good that’s our own fault .”
The process of harvesting cobs
While farmers seem positive on the potential for harvesting corncobs, a dozen or more equipment makers have seen enough profit potential to invest thousands in developing harvesting machinery.
Field days at Chippewa Valley Ethanol Co. in Brenton, Minnesota and at POET’s Emmetsburg, Iowa plant showcased three main methods of cob harvesting.
Corn and cobs in the hopper – Corncobs and corn both flow into the combine’s hopper. The combine then empties its hopper into a special separator that removes the cobs.
The towable “cob wagon” – Corn goes into the combine’s hopper and the stover (cobs, husk, and other non-seed components of corn) flows out the back of the combine as usual. A wagon pulled behind the combine catches the stover, separates out the cobs and ejects the rest of the material onto the ground.
Combine-mounted separator – A special attachment on the combine separates the cobs from the rest of the stover as it’s ejected from the combine. The cobs are blown back into a chase cart while the rest of the stover falls to the ground as usual.
Farmers appreciate having options. “We had two machines there (at the CVEC field demonstration) and one guy would say, ‘Boy, that looks like the real way to go,’ and another would say they prefer it the other way,” said Gene Fynboh, CVEC board member and retired farmer from rural Brandon, Minnesota. “That’s the way farmers are. There are advantages and disadvantages to both. The people (from the manufacturers) working with them were learning some things about their machines also.”
The rise of the cob market
With the various ways to harvest showing well in the field, the big unknown remains how a market for the corncobs will evolve.
You might think that CVEC, which prizes corncobs for their gasification value, may not be eager to have other ethanol producers bidding on cobs to distill into cellulosic ethanol. But CVEC general manager Bill Lee has the opposite opinion; he thinks the more demand for biomass the better. Competition, Lee says, is the key to driving innovation and developing a market that sustains itself long-term.
“Our model is in order to get to a sustainable and affordable supply of biomass you have to have market dynamics,” Lee said. “The way to create that is by putting in place a lot of end users that can process biomass into energy forms. You have to have people out there competing and figuring out how to do this.”
Lee said his company has had lots of interest in the gasification technology from a whole range of companies that now use huge quantities of natural gas. The University of Minnesota, Morris, a partner in CVEC’s gasification project, is also installing their own system.
Lee believes rather than pit the two uses for cobs against each other, having cellulosic and gasification both interested in biomass actually helps both thrive. In fact, Lee credit’s the POET Project Liberty for drawing biomass gasification’s attention to the potential for using corncobs.
“When people say we’re going to build a cellulosic biomass ethanol industry, it’s a little bit ludicrous when you have no infrastructure and no sustainable or economic source of feed stocks,” Lee said. “The way to create that is to put in place a lot of end users that can process this into energy forms. The competition builds the infrastructure. At some point we need to get market forces involved in this.”
When market forces take hold, they’ll help create enough supply to reliably feed both uses, Lee says.
Market forces are already asserting themselves. Jay Van Roekel, segment manager for Vermeer Manufacturing, said the fuel aspect of biomass spurred his company to get involved.
“Our excitement is the solid fuel aspect of it because that’s the use in the ethanol process today,” Van Roekel said. “The icing on the cake will be if the POETs of the world can get ethanol out of biomass effectively and affordably. That will be just that much more we can all benefit from.”