Assessment of optimal location for a centralized biogas upgrading facility

Abstract

Since the 1990s, the volume of biogas produced in the world has been increasing. Biomethane (upgraded biogas) is a more versatile renewable fuel. Biogas transportation from production sites to upgrading facilities induces a scale advantage and an efficiency increase. Therefore, exploration of costs and energy use of biogas transportation using dedicated infrastructure is needed. A mathematical model to determine the optimum location for a certain biogas upgrading plant has been presented. It was developed to describe a local biogas grid that is used to collect biogas from several digesters and to deliver it to a central upgrading point. The model minimizes operational and maintenance costs per volumetric unit of biogas. The results indicate that cooperation between biogas producers in collecting biogas by means of a star layout reduces the cost of biomethane production (investment costs by 22.4–24.8% and operating and maintenance costs by 1.7–10.9%) relative to using a decentralized method. Merging smaller digesters into a smaller number of larger biogas upgrading plants reduces the biomethane production costs for the same biogas volume source.