Thermodynamic analysis of the potential application of methanol steam reforming in marine internal combustion engines

The maritime industry is shifting from fossil fuels to alternatives to reduce pollutants and emissions. Integrating methanol steam reforming (MSR) with waste heat from internal combustion engines (ICE) optimizes combustion and efficiency. However, a comprehensive evaluation of this MSR-ICE system, especially regarding reforming capability and key performance indicators, has not been conducted. This study develops a process model of the MSR-ICE system to assess its potential for marine medium-speed engines. The effects of MSR reaction temperature, steam-to-carbon (S/C) ratio, and reforming ratio on system performance were analyzed. Results show the MSR-ICE system is thermodynamically feasible. Increasing the reforming ratio enhances efficiency, reducing fuel consumption and carbon emissions. However, the maximum reforming ratio is limited by MSR reaction temperature and S/C ratio. For instance, at 160°C with S/C = 1, the maximum reforming ratio is 0.6, while at 240°C, it drops to 0.3. Optimization strategies include low-temperature reforming, maximizing the reforming ratio, and controlling the S/C ratio.