HYBRID SOLID OXIDE FUEL CELL AND INTERNAL COMBUSTION ENGINE PROPULSION SYSTEM FOR MARITIME DECARBONIZATION

Maritime transportation represents a cornerstone of global trade and economic exchange; however, it remains one of the most carbon-intensive sectors, contributing roughly 3% of total global CO2 emissions. In response to this challenge, the International Maritime Organization (IMO) has committed to achieving carbon neutrality by 2050, promoting the development of innovative propulsion technologies aimed at drastically reducing greenhouse gas emissions. This thesis explores the feasibility of a hybrid propulsion system integrating a Solid Oxide Fuel Cell (SOFC) with an Internal Combustion Engine (ICE), both operating with non-fossil, potentially zero-emission fuels such as hydrogen and ammonia. The research was conducted within the framework of the SOFFHICE project, a collaborative project involving Politecnico di Torino, the University of Genoa, and the University of Bologna. The system was tested under three different configurations initially with hydrogen then with ammonia: first, with a conventional ICE operating independently; second, as a hybrid SOFC and ICE system where the two units work separately without integration; and third, in an advanced hybrid mode in which the SOFC anode exhaust gases are fed into the ICE to recover additional power. A comprehensive thermodynamic and electrochemical analysis of the SOFC subsystem was carried out, including auxiliaries and heat recovery components, to evaluate its thermal and electrical performance. The ICE efficiency was modeled using experimental data to ensure realistic representation. Furthermore, a storage volume analysis was carried out to evaluate the feasibility of using hydrogen and ammonia as substitutes for conventional marine fuels such as LNG, with the goal of reducing greenhouse gas emissions. The combined system was then assessed for application on a real ferry, where the SOFC provides the steady base-load power while the ICE supplies additional power for propulsion and peak demands.