Increasing Methane Production by Anaerobic Co-Digestion of Slaughterhouse with Fruit and Vegetable Wastes

Despite fossil fuels, the energy supply from biogas process is of renewable energy resources; this kind of energy can be generated in all parts of the world. Thus, the potential of anaerobic co-digestion for production of methane from wastes of an industrial slaughterhouse and fruit and vegetable center in the Hamadan city, west of Iran, was investigated. The digester was operated under the mesophilic (35 - 37°C) condition for a period of 40 days with 3 different C/N ratios (20/1, 30/1 and 40/1). Before operation of digester, the amounts of C and N in the wastes were measured and during the experiments pH and composition of the biogas were determined. The cumulative amounts of the generated total biogas and methane at the 3 examined C/N ratios 20/1, 30/1 and 40/1 were, respectively 181, 201.7 and 162.5 L and 129.8, 149.2 and 114 L. The results indicated that the highest contents of biogas and methane (201.68 and 149.29 L, respectively) were obtained at C/N of 30 within 31 days.