On Safety Aspects of Ammonia as Marine Fuel

Despite the fact that maritime transport represents one of the most energy-efficient transport modes shipping, global shipping sector is responsible for up to 4% of the total CO2 emissions. Hence, International Maritime Organization (IMO) fixed measures in a greenhouse gas (GHG) strategy to reduce the emissions of greenhouse gases from international shipping industry. One approach fir the implementation of the IMO GHG strategy is the use of alternative marine fuels comprising biofuels, electricity as well as e-fuels. Currently, the scientific and technical discussion highlighting ammonia (NH3) as one important alternative marine fuel since ammonia is usable in classical combustion engines but also as a hydrogen-carrier for the further production of electricity in fuel cells. In both applications, the ammonia fuel has to be stored and further treated in the vessels which leads to a variety of open questions related to ship constructions, space requirements as well as for safe ship operations. Literature review reveals that safety aspects together with the techno-economic assessment of ammonia propelled vessels has not been covered much in the scientific literature until now. A reason for that might be that shipbuilding industry as well as operators are at the very beginning of implementing ammonia as fuel, since there are right now no orders for ammonia fueled vessels. The current study investigates the research question how to assess the regulatory framework and techno-economic requirements for using ammonia as marine fuel on ships together with the related safety aspects. The research is based on secondary data research, preliminary-safety guidelines, case studies and expert interviews that were collected and analyzed between 2020 and 2023 in several national and international projects about future marine fuels.