Biomethane production as an alternative bioenergy source from codigesters treating municipal sludge and organic fraction of municipal solid wastes.

Energy recovery potential of a mesophilic co-digester treating OFMSW and primary sludge at an integrated biomethanization plant was investigated based on feasibility study results. Since landfilling is still the main solid waste disposal method in Turkey, land scarcity will become one of the most important obstacles. Restrictions for biodegradable waste disposal to sanitary landfills in EU Landfill Directive and uncontrolled long-term contamination with gas emissions and leachate necessitate alternative management strategies due to rapid increase in MSW production. Moreover, since energy contribution from renewable resources will be required more in the future with increasing oil prices and dwindling supplies of conventional energy sources, the significance of biogas as a renewable fuel has been increased in the last decade. Results indicated that almost 93% of annual total cost can be recovered if 100% renewable energy subsidy is implemented. Besides, considering the potential revenue when replacing transport fuels, about 26 heavy good vehicles or 549 cars may be powered per year by the biogas produced from the proposed biomethanization plant (PE = 100,000; X(PS) = 61 g TS/PE·day; X(SS-OFMSW) = 50 g TS/PE·day).