Marysville Ethanol, LLC (Marysville) currently operates a 50 million gallons-per-year-dry mill ethanol manufacturing facility (the facility) in Marysville, Michigan. The facility also produces approximately 146,000 tons per year of animal feed known as distiller grains. Ethanol manufacturing produces by-products such as Distillers Dried Grains with Solubles (DDGS) and Distillers Wet Grains (DWG). The facility started operations in or around October 2007.
At the facility, the company uses the dry mill process, where the entire grain kernel is ground into flour. The starch in the flour is converted to ethanol during the fermentation process, creating carbon dioxide and DDGS. The facility includes a recuperative thermal oxidizer (RTO) with a heat recovery steam generator and a DDSG cooling baghouse C70.
On July 12, 2007, the Michigan Department of Environmental Quality (MDEQ) issued to Marysville a Permit to Install (PTI) with conditions, PTI #175-05B. This permit restricts the RTO heat recovery steam generator to 10.75 pounds of nitrogen oxides (NOX) per hour, and the DDGS cooling baghouse to 1.20 pounds of particulate matter with an aerodynamic diameter less than or equal to a nominal 10 micrometers(PM10) per hour.
On September 23, 2010, Region 5 issued a Notice of Violation (NOV) to Marysville for exceeding its allowable NOx emissions limits (10.75 lb/hour) and PM10 emissions limit (1.20 lb/hour) at the RTO heat recovery steam generator and the DDGS coolin