Biomass-Powered Ethanol Plants

RUNNING ON BIOMASS: CVEC is one of several ethanol plants using biomass to reduce their carbon footprints and save on energy bills.

The demand for ethanol with a lower carbon footprint seems to be spurring a movement in which ethanol plants are using biomass to power their operations. The lower carbon score of the manufacturing process can make the ethanol product itself more attractive, according to Mike Jerke, general manager of Chippewa Valley Ethanol Co.

The Benson, Minn.-based ethanol plant produces about 46 million gallons annually and, when the price of natural gas is high, powers itself with corncobs and wood chips. The company is also in the process of permitting the system for sunflower hull feedstock. “If you can replace petroleum sources with something renewable, that gives you an end product that has more value in places like California, where they’re concerned about the carbon index score of the fuel they’re buying,” Jerke says.

In addition to favorable carbon scores, the biopower movement in the ethanol industry was pushed in 2005-’06 by rising natural gas prices, Jerke explains. The gasification system CVEC employs creates a gas that can be handled similarly to natural gas. “We refer to it as producer gas,” he says. That producer gas is piped to the burner to heat water to produce steam that is distributed into the plant to run the process.

And CVEC isn’t the only one. Poet LLC has proposed systems that utilize biomass combined heat and power, and Archer Daniels Midland Co. is using biomass cogeneration in Nebraska and Iowa. It’s cleaner than petroleum and is simply the “right thing to do,” Jerke says. In addition, the current rate structure curtails the amount of natural gas that can be used on high-demand days, such as those in the middle of brutal Minnesota winters. So using biomass alleviates the need to resort to more expensive gas such as liquefied petroleum. “There are a number of benefits,” Jerke says.

—Lisa Gibson