Benson, Minn., ethanol plant takes the heat, and puts it back to work

BENSON -- An energy savings project undertaken by the Chippewa Valley Ethanol Company in Benson is cutting the company's natural gas costs by about $700,000 annually.

The Benson ethanol plant is among 36 facilities in Minnesota realizing ongoing energy savings thanks to one-time energy upgrade grants administered by the Minnesota Department of Commerce Division of Energy Resources.

The grants, funded by the American Recovery and Reinvestment Act, were targeted to make energy efficiency improvements to commercial, industrial and nonprofit facilities across Minnesota.

According to a news release from the Department of Commerce. the project in Benson takes advantage of the energy used by the plant's regenerative thermal oxidizer. The system heats the exhaust gases from the plant's distillers dried grains production to 1,200 degrees Fahrenheit. The high temperatures break down the volatile organic compounds in the exhaust to meet air emissions standards.

In the past, much of the heat used in breaking down the compounds was vented along with the exhaust.

Chippewa Valley Ethanol Company General Manager Mike Jerke told the Tribune that the company invested in engineering and equipment to capture as much of that heat as possible. It is now recirculated and used to heat water as part of the plant's production system.

All of the ethanol plants in Minnesota rely on regenerative thermal oxidizers to meet air standards, but the systems are different at each plant. There was no "cookie cutter'' model out there when Chippewa Valley Ethanol went to work to develop the engineering and mechanical system to make this energy saving feature work, Jerke said.

According to the Department of Commerce, a $500,000 grant was awarded to Chippewa Valley Ethanol Company toward the $2 million project.

Other awarded projects range from an upgraded heating and cooling system at St. John's Hospital in Maplewood to the installation of new power supply units at Gerdau Ameristeel in Duluth.