Integration of biogas dry methane reforming and electrolysis: An efficient pathway for green hydrogen production

Abstract

In line with the global green transition, hydrogen is increasingly being recognized as a crucial component of decarbonization strategies. Advancing green hydrogen technologies and diversifying feedstock sources have thus become priorities. This study explores the potential to produce green hydrogen from biogas through dry methane reforming (DMR) using oxy-fuel combustion. To further enhance green hydrogen output, the system integrates either a proton exchange membrane electrolysis cell (PEMEC) or a solid oxide electrolysis cell (SOEC), which not only provides additional hydrogen but also eliminates the need for an external oxygen supply. The application of oxy-fuel combustion enables efficient capture of biogenic CO2, qualifying the process for carbon tax incentives. An economic assessment, incorporating carbon tax considerations and a sensitivity analysis, is conducted. Among the evaluated configurations, the DMR-SOEC integration achieves the highest energy efficiency (74.62 %), owing to the effective utilization of waste heat from flue gas. Economic analysis reveals that the DMR-only system attains the lowest levelized cost of hydrogen (LCOH) across all scenarios. However, its hydrogen production is 33.3 % lower than that of systems integrated with PEMEC or SOEC, resulting in a 39.67 % to 60.96 % lower net present value. Scenarios involving increased biogas capacity or reduced costs of electrolyzer stacks and renewable electricity demonstrate the economic advantages of the DMR-SOEC integration. This study quantifies the LCOH of green hydrogen produced from biogas via DMR and provides insights into the integration of electrolysis technologies. Overall, the proposed approach presents a feasible pathway toward 100 % green hydrogen production, supporting a sustainable energy transition.