Process analysis of a molten carbonate fuel cell on-board application to reduce vessel CO2 emissions

The International Maritime Organization has promulgated a set of regulations that demand for the reduction of CO2 emission. Specifically, a reduction of 40% and 70% compared to 2008 is required by 2030 and 2050, respectively. A rough estimate suggests that 20% can be obtained with speed and routes optimisation, while the residual reduction requires the use of more sustainable technology. To achieve the latter objective in a short time, the authors propose existing vessel retrofitting using molten carbonate fuel cells (MCFCs). Indeed, MCFCs allow for additional energy production while capturing CO2 emitted by the conventional vessel engines. Using the software Aspen Plus coupled with the homemade SIMFC code, the system has been simulated and the results show the proposed solution as very promising. In particular, also the impact on the performance of an additional membrane system for CO2 finishing and of different recycle configurations for unreacted H2 recovery is discussed.