The Minnesota Pollution Control Agency is taking comment until July 24 on its intent to approve an air permit change for Chippewa Valley Ethanol Co. (CVEC) at its facility located northwest of Benson, Minn.
Besides ethanol, the facility also produces Dried Distillers Grains with Solubles (DDGS), a byproduct of ethanol production. This permit action is a major amendment and authorizes construction of a new natural gas boiler, DDGS transfer equipment for two DDGS loadout options, and two new baghouses to control particulate emissions from the DDGS handling and loadout. This action also authorizes the removal of a natural gas- and biomass-fueled boiler, the wood gasifier, and corresponding processing and control equipment. The use of a temporary boiler replacement is also authorized to transition between the new and old boiler.
The new equipment includes: Boiler #4, a 99.6 MMBtu/hr natural gas fired boiler exhausting from a new stack vent, replacing Boiler #3; and a temporary boiler, a 99.5 MMBtu/hr natural gas-fueled boiler exhausting from a new stack vent. For the new Boiler #4, the company requested an annual propane usage limit of 975 hours to reduce NOX emissions.