Current Biogas Production and Utilization at US Wastewater Treatment Plants: It’s All About Co-Digestion

摘要: The recent expansion in the definition of “cellulosic biofuel” under the Renewable Fuels Standard, and the consequent eligibility of biogas-derived fuels to generate documented, tradable production assurances known as Renewable Identification Numbers (RINS), is expected to greatly expand demand for turning biogas into a transportation fuel. Along with landfills and free-standing anaerobic digesters, wastewater treatment plants (WWTPs) are a principal source of biogas. However, since roughly half of the biogas produced by WWTPs is used for digester heating, the wastewater industry may be unable to increase production to keep pace with demand. According to a recent survey, 8 million dry tons of biosolids per year are generated from approximately 15,000 wastewater treatment plants (WWTPs) in the US This resource has a total energy potential of 9.86× 10 7 MMBtu/year and could provide the equivalent of …