SOFC-based propulsion systems for maritime applications

The decarbonization of maritime transport is a crucial issue in recent times, since this sector continues to account for approximately 2.8% of the global CO2 emissions. To address this issue, various proposals have been put forward to promote the utilization of renewable and low/zero carbon fuels in marine applications. In this context, this study aims to define different configurations of innovative naval propulsion systems utilizing Solid Oxide Fuel Cells (SOFC) fed by ammonia. A particular case study has been examined, focusing on a vessel with a known mission profile and engine room hosting a conventional internal combustion engine. The analysis explores the possibility of incorporating the proposed SOFC-based propulsion system into this vessel by considering the weights and volumes of the modules and onboard fuel storage. Each SOFC module includes not only the stacks but also their Balance of Plant (BoP) components, such as the afterburner and multiple heat exchangers designed to enhance heat recovery and maximize system efficiency. In particular, the proposed configuration is assessed in terms of fuel consumption and design compactness, taking into account specific constraints such as its mission profile and the available space in the engine room of the considered vessel. The analysis is carried out through properly developed thermochemical models able to determine the operational characteristics of the system, while also taking into account the thermal management of the modules.