Title : Feasibility analysis and design optimization of MCFC gas recirculation for enhanced carbon capture
Abstract:
“Hard to abate” sectors present significant challenges in reducing CO2 emissions due to their dependence from fossil fuels and limited low-carbon alternatives. One of the most important sectors is the maritime sector, which accounts for approximately 2-3% of global CO2 emissions. Removing CO2 in this sector is crucial to achieving the 40% and 70% reduction targets set by the International Maritime Organization (IMO) for 2030 and 2040. Molten carbonate fuel cells (MCFCs) represent a promising technology for carbon capture and storage (CCS) on board ships, offering an innovative solution to reduce CO2 emissions from the maritime sector. One of the main advantages is that this type of technology is a modular device and can work high performance even when treating exhaust gases with low CO2 contents, 4-5% by volume. It also allows the retrofit on exiting vessels. Taking advantage of this peculiarity, the exhausted gases of the ship's engines can be fed to the cathode side and the CO2 present in the exhausted gases is thus transferred to the anode side. Here it can be easily separated through condensation and a simplified liquefaction from the other components (mainly steam and unreacted hydrogen). Furthermore, the energy simultaneously produced by the MCFC stack can be used to reduce the load of ship's engines and consequently decreasing the emissions. However, process optimization is key to maximizing CO2 capture efficiency and making it economically sustainable. For this reason, in this study a new system scheme is proposed and simulated to maximize the global capture of CO2 through the optimization of the recirculation of the process streams.
