Life cycle assessment of diesel and hydrogen power systems in tugboats

•Life cycle assessment of tugboats’ diesel and hydrogen power systems is conducted.•Hydrogen fuel cells for tugboats can reduce global warming impact by up to 85%.•Exposure to toxic substances when adopting hydrogen fuel cells is discovered.•Recycling in the decommissioning stage reduces environmental burden by up to 44%. Hydrogen fuel cell has benefits in reducing greenhouse gas emissions and air pollutants. This study conducts Life Cycle Assessment to evaluate the environmental impact of two power systems (hydrogen fuel cells and diesel engines) in tugboats. Results indicate evident reduction potential in global warming (83.9–85%), acidification (45%), eutrophication (54%) and photochemical oxidation (50%) when adopting hydrogen. Specifically, the hydrogen-powered tugboat can reduce up to 48,552,160 kg CO2 equivalent of global warming, 51,930 kg SO2 equivalent of acidification, 11,476 kg PO4- equivalent of eutrophication, and 2,629 kg C2H4 equivalent of photochemical oxidation compared to the diesel tugboat. However, exposure to toxic substances of hydrogen-powered tugboats, especially in marine aquatic, will increase due to the processes in the hydrogen fuel cell manufacturing and hydrogen fuel supply stages. Additionally, the recycling of materials in the decommissioning stage will reduce the overall environmental burden for both power systems, varying from 8.5% to 44%.