Numerical analysis of a PEM fuel cell fed by a steam reformer integrated into an internal combustion engine

In recent years, the shipping sector has faced the challenge of reducing greenhouse gas emissions, as growing demand for international trade has led the sector to consume around 300 million tons of fossil fuels per year. Internal combustion engines (ICEs) continue to be the main source of propulsion for navigation, but the use of fuel cells (FC) is being added to them to reduce emissions. In this work, an integrated combined heat and power (CHP) hybrid power generation system with an ICE, a steam methane reformer, a high temperature-proton exchange membrane FC (HT-PEMFC) assisted with a battery energy storage system (BESS) for marine applications is presented. The addition of a steam methane reformer allows the on-board production of hydrogen, which is used to supply the FC. The system also includes on-board CO2 capture after reforming. Two operating modes for FC integration are analyzed: direct connection to the ship's grid and independent operation for auxiliary loads, assisted by the BESS. The system, composed of four engines of 2430 kW each (total installed power of 9720 kW) and a 500 kW FC, is simulated using Thermoflex, a commercial lumped parameter code, and Simulink-Matlab model for the detailed description of FC and BESS. The main results obtained show a reduction in CO2 emissions compared to using only ICEs of the same power and highlight the crucial role of BESS in regulating power supply according to varying load demands.