An efficient low-carbon hydrogen-electricity cogeneration system based on coal-biomass complementary gasification coupling with solid oxide fuel cells

Currently, hydrogen production primarily relies on fossil fuels, suffering from low energy efficiency and high carbon emissions. Developing low-carbon, efficient, and economically viable hydrogen production solutions has become a critical issue requiring urgent attention. This research proposes a hydrogen-electricity cogeneration system based on complementary coal-biomass gasification technology and solid oxide fuel cells. This system employs the synergistic effects of coal and biomass during gasification to enhance thermodynamic efficiency and reduce carbon emission intensity. Additionally, the system utilizes heat recovered from the SOFC stack and afterburner to supply thermal energy for the pyrolysis reaction. This enhances the energy grade matching between the thermal supply and demand sides, enabling efficient utilization of SOFC waste heat. This research utilized Aspen Plus software to simulate and validate both the novel and reference systems, evaluating their performance across three dimensions of thermodynamics, carbon emissions, and economic viability. Compared to the reference system, the novel system demonstrated a 4.64% improvement in energy efficiency, a 4.05% increase in exergy efficiency, and a 60.36% reduction in CO₂ emissions. During the lifecycle, the new hydrogen-electric cogeneration system achieved a DPP of 5.42 years and an NPV of 171,057.92 k$, demonstrating better economic performance than the reference system. Sensitivity analysis indicates that increasing SOFC temperature, pressure, and fuel utilization enhances power generation performance. Additionally, hydrogen price, discount rate, and fuel cost are key parameters influencing system economics. This research offers new perspectives for developing efficient coal and biomass utilization technologies and low-carbon hydrogen production techniques.