Green hydrogen integrated biomass gasification–methanation coupling system for efficient conversion of syngas to methane

Abstract The global energy crisis and escalating environmental concerns are driving the development of clean, renewable energy sources. However, significant variability in the quality of biomass conversion products hinders widespread biomass utilization. This study proposes an integrated system combining biomass gasification, water electrolysis, and methanation to enable the stable production of high-purity methane (CH4) from diverse biomass feedstocks. Through rigorous process modeling using Aspen Plus, key factors influencing integrated system performance were identified, with particular emphasis on the synergistic coupling between the water electrolysis, biomass gasification, and methanation units. Results indicate that elevated temperatures in both the electrolyzer and gasifier enhance carbon conversion efficiency and CH4 production rate. Under optimized conditions, the CH4 volumetric fraction in the product gas exceeds 99.7%, while the overall system efficiency reaches 55%. This integrated approach not only enhances biomass conversion efficiency but also reduces energy consumption and processing costs. Furthermore, it provides crucial theoretical insights and technical support for designing and implementing scalable, multiinput renewable energy systems that coutilize biomass and green electrolytic hydrogen (H2) for sustainable fuel production.