Performance Prediction of a Compact On-Site Autothermal Methanol Reforming Hydrogen Production System with Integrated Waste Heat Recovery

This study presents a compact autothermal methanol reforming system for on-site hydrogen production, incorporating waste heat recovery to enhance energy and economic efficiency. The effects of the water-to-methanol ratio (W/M), air-to-methanol–water ratio (A/M), and feed flow rate were evaluated through simulations. Six heat recovery strategies were developed, utilizing thermal energy from catalytic combustion exhaust and purified hydrogen to support feed pre-evaporation, reforming, or both. Simulation results showed that hydrogen production efficiency was primarily influenced by W/M, whereas exergy efficiency was more sensitive to A/M. Optimal conditions were identified as W/M = 1.4 and A/M = 1.4. Among the strategies, Strategy VI achieved the best performance, with 97.3% methanol conversion, 11.3 L/min hydrogen production, 73.5% energy efficiency, and 67.3% exergy efficiency, while reducing carbon dioxide emissions to 8.18 kg per kilogram of hydrogen. Economic analysis indicated the highest annual profit for Strategy VI, with a projected payback period of eight years under retail hydrogen pricing.