Corn cobs could be the new 'green' fuel at Willmar plant
WILLMAR -- Willmar Municipal Utilities will test a new "recipe'' for producing energy: corn cobs and coal.
The utility's power plant will conduct a test burn of cobs and coal later this winter. If the test burn is successful, corn cobs could help the utility comply with the state's renewable energy mandate and help boost local farm income.
"Burning cobs may be able to help us meet our renewable energy goals and support the local economy at the same time,'' says Bruce Gomm, Willmar Municipal Utilities general manager.
The state is mandating all utilities, by 2025, have at least 25 percent of energy needs met by renewable sources. Willmar hopes generating power from biomass such as corn cobs, as well as its $10 million wind turbine project, will help meet the mandate.
The test burn, slated for February, will determine if cobs burn satisfactorily with coal and if the process is effective and efficient, explains Jon Folkedahl of Willmar, a consultant working with the utility on the corn cob project.
Second, the test will provide data for the Minnesota Pollution Control Agency in issuing a permit that will allow Willmar to permanently burn cobs and coal.
Meanwhile, Willmar is seeking an interim permit to allow the test burn, according to Folkedahl.
Corn cobs have an energy value of 75 percent to 80 percent of Powder River Basin coal, which Willmar buys and burns at the local power plant, located near downtown.
"That's really good,'' says Folkedahl. "For biofuels, it's right at the top of the list.''
There are several reasons for adding corn cobs to coal, according to the University of Missouri, which is burning cobs to generate electricity at its campus power plant:
- Cobs are abundant in the corn belt.
- Cobs are not used by most farmers.
- Cobs decompose slowly in the soil and offer little value as residue cover.
- Cobs have low sulfur and ash content, and have good heating value.
Folkedahl says cobs are considered a renewable fuel because cobs are recycling carbon dioxide already in the air.
"When people talk about green energy and renewable fuels, that's really the key is that the carbon dioxide released is not fossil, it's recycled,'' he says.
The first step for Willmar is to collect the cobs. Folkedahl said approximately 500 tons of cobs would be needed to provide data to satisfy MPCA.
The collection process, which began Oct. 29 on 650 acres of corn land farmed by Ryan and Lonnie Fosso of Pennock, is about two-thirds complete. The Fosso farm was also the site in mid-October of cob harvesting by Chippewa Valley Ethanol Company for fuel at the plant in Benson.
The Fossos have been good to work with, says Vernon Flamme of North Bend, Ind., who's combining the corn and collecting the cobs for Willmar.
The corn is combined normally, but a special machine pulled by the combine collects the cobs and blows the leaves and stalks out the back. Trucks are hauling and piling the cobs on a runway, just west of County Road 5, at the old city airport.
Flamme invented the cob collector, which he named the Cob Caddy. This year, Flamme sold the patent for the machine to Vermeer Corporation, which renamed it the Cob Harvester.
Flamme supports the use of corn cobs as a biomass fuel for power plants.
"There are a lot of these coal-fired plants in the country and the beauty of the cob is it doesn't take any fertility or anything away from the land,'' says Flamme. "So why not save them and make energy out of them for the country?''
The cobs will be burned at the rate of about 20 percent cobs to 80 percent coal, according to Folkedahl. Once all emission controls are in place, the utility hopes to burn as much as 75,000 tons of coal and 25,000 tons of biofuels, particularly corn cobs, which would require 20,000 to 40,000 acres of corn to be harvested for cobs in the area.
Initial rates peg the cost of cobs between $30 and $60 per ton. The utility is paying the Fossos $40 per ton.
"We hope that we can start out small and as the market for corn cob grows, farmers will invest in the harvest equipment and eventually the utility will be able to reach that biofuels goal,'' Folkedahl says.