WHAT IS THE BEST USE FOR DIGESTER GAS?

With increasing energy costs, wastewater utilities are becoming more interested in reducing purchased energy requirements (natural gas and electricity) or substituting with less expensive sources of energy that may be generated on site. This is particularly true for utilities implementing thermal drying, an energy intensive process. Biogas from anaerobic digestion is used in several installations to offset some of the purchased energy requirements for drying. But is this the best use for the biogas? Would using the gas to generate power and recovering waste heat from that process be a better use? These questions and others related to energy management and alternative energy options will be addressed in this paper.