Life Cycle Assessment of a Reformed-Methanol Fuel Cell for Passenger Boat Propulsion

This study presents the Life Cycle Assessment of a High-Temperature Methanol Fuel Cell for a passenger vessel. The proposed propulsion system is based on onboard hydrogen production via methanol steam reforming and subsequent power generation through a high-temperature PEM fuel cell. A cradle-to-wake LCA analysis was carried out using openLCA, employing as a functional unit one day of vessel operation (8 h, 1920 kWh of mechanical work at the propeller shaft, supplied by 2000 kWh of fuel-cell electrical output). A 20-year service life, covering the 16 impact categories of ILCD 2011 Midpoint+, ten of which are discussed in detail (climate change, particulate matter, acidification, human toxicity non-cancer effects, freshwater ecotoxicity and mineral resource depletion among them), was considered. The system was evaluated against conventional diesel propulsion in terms of fuel consumption, operational cost and life-cycle impacts. The results indicate that the diesel-based case shows a GWP of 1458 kg CO2-eq per day. The fuel cell system is reported for all four methanol sources: bio-methanol gives −82% and wind-based e-methanol −86% against the diesel reference, while fossil methanol gives +36% and grid-based e-methanol +115%. A parameter sensitivity analysis and a Monte Carlo simulation (1000 paired iterations) show that the fuel cell system has lower impacts than diesel in eight of ten categories in all iterations, whereas mineral resource depletion is 26–63 times higher, a gap that end-of-life platinum recycling reduces to 5–14 times. This work supports methanol as a hydrogen carrier for decarbonising maritime transport where a direct electrification scenario is still not applicable.