Biogas Upgrading for Injection into the Gas Grid - Quality aspects, technological and ecological consideration

Next to wind and hydro power the power generation with biogas as fuel is an emerging technology for electricity generation. The number of digesters in Germany, e. g., doubled since 2003. Traditionally, in rural areas biogas is a product from conditioning liquid manure. Today, biogas plants in Germany are built for higher raw gas production capacities and for energy crops as feedstock. Alas, when converting the biogas to electricity the onsite use of the heat produced as a byproduct can seldom be used efficiently. Though most biogas plants in Germany have an electric power output of below 500 kW the on-site use of the produced heat is only about 10 %. The rest of the heat is lost to the ambient.