Performance evaluation of a biodiesel-methanol dual-fuel high temperature proton exchange membrane fuel cell cogeneration system for marine applications

In response to the International Maritime Organization's (IMO) 2050 net-zero greenhouse gas emissions target for shipping, this study proposes a high-temperature proton exchange membrane fuel cell (HT-PEMFC) cogeneration system utilizing biodiesel-methanol dual-fuel. The system aims to enhance the energy efficiency and environmental sustainability of marine power systems. Biodiesel is converted into hydrogen-rich syngas via autothermal reforming, while the residual heat drives methanol steam reforming. This configuration enables cascading waste heat utilization and fuel complementarity. The performances of single-fuel and dual-fuel systems are compared using an energy-economy-environment (3E) analysis. Results indicate that the dual-fuel system achieves a power generation efficiency of 40.85 %, representing a 9.99 % increase over the single-fuel system. Combined heat and power (CHP) efficiency rises by 2.81 %–82.95 %, and power generation increases by 101.33 % (reaching 855.10 kW). Life cycle assessment reveals that the green methanol pathway reduces carbon emissions by 55.41 % (to 294.58 g/kWh) compared to conventional diesel. Optimal operating parameters, determined via NSGA-II multi-objective optimization, further improve power generation efficiency to 47.06 %–15.20 % higher than the design operating point. This system presents a new technical pathway for ship decarbonization through multi-fuel complementarity and efficient waste heat recovery.