Biogas as an option for a low carbon campus: A case study at AIT

This study investigates the feasibility of generating biogas from the food wastes available at the Asian Institute of Technology (AIT) and substituting the LPG consumption in the campus with the biogas. The study shows that current amount of food waste has the potential to produce about 85-123 m³ per day of biogas. After analyzing existing small scale biogas plants in Thailand, three digester designs, i.e. wet digestion one stage, wet digestion two stages and dry digestion, have been shortlisted and further analyzed. Assuming that about 60% of the food waste could be collected, i.e. 800kg/day, and used in the digesters, the wet digester with one stage reactor is identified as the most attractive with a payback period of 7 years. The net GHG mitigation is estimated to be 718 tCO_2e/year. CDM implementation is not feasible because its expected financial gain is lower than its investment cost.