ENV-09-03 DIGESTER GAS ENERGY UTILIZATION: OPPORTUNITIES AND REALITIES

Description:

As energy development booms on the western slope of Colorado, the City of Grand Junction is investigating several opportunities to implement energy conservation and make greater utilization of renewable energy sources. The Persigo Wash Wastewater Treatment Plant (WWTP) which serves the City and surrounding communities in Mesa County, is just such a source of renewable energy. From January 2003 through May 2006, the WWTP produced an estimated 100,000 cubic feet per day (CF/day) of digester gas. A small quantity of the gas is burned to heat the anaerobic digester, while the remainder is flared. The estimated average quantity of digester gas not utilized to heat the digesters is 72,600 CF/day. The heat content of the digester gas produced approximately 635 BTU/CF. This compares to natural gas, which typically has a heat content of 1,000 BTU/CF.