ICM/PBS personnel provided design, fabrication, technical development, start-up and training services for the implementation of the anaerobic Bio-Methanation system at the Northern Lights Ethanol Fuel Ethanol Plant in Big Stone City , SD. The turnkey Bio-Methanator plant is a skid–mounted unit designed and built by ICM-Phoenix for NLE.  Northern Lights Ethanol, LLC is a 40 MM GPY plant, designed and built by Broin and Associates of Sioux Falls, SD.

     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 Big Stone City for installation, which required less than one week. The bio-reactors are pre-molded FRP including all internals.

     The complete unit was installed in January 2002, during plant construction, and started up in June 2002, along with the plant. 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 RO reject and waste CIP water, and consistently produces effluent waters suitable for re-use in the cook section of the fuel ethanol process. This technique results in a “Zero Process Discharge“ plant at NLE. No process water is discharged to the environment.

     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 $24,000 per year, which more than pays operating costs of the Bio-Methanator.