Performance analysis of sorption-enhanced steam reforming solid oxide fuel cell cogeneration system with biodiesel for marine applications

Transitioning to cleaner marine fuels is imperative for sustainable shipping. Solid oxide fuel cells (SOFCs) are promising for low-carbon marine power due to high efficiency and fuel flexibility. However, conventional SOFC systems still entail significant carbon emissions. This study aims to propose and evaluate a novel biodiesel-based sorption-enhanced steam reforming (SESR) SOFC cogeneration system for marine application, targeting enhanced efficiency and carbon-negative operations. The system integrates biodiesel reforming for hydrogen production and a carbon capture unit via SESR. Energy, environmental, and economic analyses are employed for performance evaluation. The results demonstrate that the system achieves a remarkable power generation efficiency of 49.47% (representing a 4.79% increase over conventional reforming) and a negative lifecycle carbon emission of −299.89 g/kWh (a 145.39% reduction compared to diesel engines) at the design point. The superior efficiency stems from the elevated H₂ partial pressure fed to the SOFC anode, while the negative emissions are achieved through the combination of in-situ CO₂ capture and the inherent carbon negativity of biodiesel during its production phase. The study also examines the impact of key parameters (e.g., steam-to-carbon ratio, excess air coefficient). Economically, the levelized cost of energy (LCOE) is 0.2831 $/kWh, currently higher than heavy fuel oil (0.162 $/kWh). But it emphasizes the importance of carbon tax mechanisms and reducing biodiesel costs through large-scale production for enhancing the economic feasibility of negative-carbon power systems. This work provides a viable technological pathway for carbon-negative power generation in maritime sectors, offering critical insights for shipping decarbonization and green vessel development.