ICM/PBS personnel provided design, fabrication, technical development, start-up and training services for the implementation of the anaerobic Bio-Methanation system at the Exol Fuel Ethanol Plant in Albert Lea, MN. The turnkey Bio-Methanator plant is a skid–mounted unit designed and built by ICM-Phoenix for Exol, LLC, which is a 40 MM GPY plant, designed and built by Broin and Associates of Sioux Falls, SD. The Bio-Methanantor was added to the plant as part of an overall plant expansion in 2001.

     The ICM/PBS Bio-Methanator system consists of dual upflow expanded-bed, 30,000-gal bio-reactors, capable of removing up to 4,000 pounds per day of COD (Chemical Oxygen Demand) each. The bio-reactors are located out-of-doors, while all control and sampling units are skid-mounted and located inside the plant's process building.  The two-level control skid was used as a basic structure to provide an add-on building to the existing mechanical building, by adding metal skin and insulation to the outside of the skid.

     The entire anaerobic system was pre-fabricated at the ICM shop in Colwich and shipped to the site in Albert Lea for installation, which required less than one week. The bio-reactors are pre-molded FRP including all internals.

     The entire unit was installed in May 2001, during plant expansion construction, and started up in October 2001. Start-up and personnel training were completed in ten days and the plant was turned over to operating personnel shortly thereafter. The Bio-Methanator has operated successfully since start-up averaging over 90% COD reduction of a combination of evaporator condensate and dryer stack scrubber water, and consistently produces effluent waters suitable discharge to the City of Albert Lea.

     Daily operating costs are extremely low, requiring only one to two hours per day of operator and lab time along with small amounts of nutrient chemicals and less than 27 operating horsepower. Bio-gas produced by the system is piped to the plant’s DDGS dryer providing an energy return of approximately $27,000 per year, which more than pays operating costs of the Bio-Methanator.