Decarbonizing cement plants via a fully integrated calcium looping-molten carbonate fuel cell process: assessment of a model for fuel cell performance predictions under different operating conditions

This study is part of a comprehensive research devoted to the integration of a Calcium Looping (CaL) process with a Molten Carbonate Fuel Cell (MCFC) for the decarbonisation of a full-scale cement plant. In the proposed process, where the energy intensive oxy-combustion occurring in the CaL calciner is replaced with a conventional combustion in air. The CO2-rich gas leaving the calciner is injected into the MCFC cathode while the anode side is fuelled by H2-rich gases produced by a sorption-enhanced reforming (SER) process. The high CO2-concentrated gas leaving the anode will be sent to valorisation processes and/or the CO2 final disposal. Here we focus on modelling, simulation and characterization of the MCFC used as a device for CO2 separation as well as electricity production, here considered as a process by-product. Polarization curves (I–V curves) and Electrochemical Impedance Spectroscopy (EIS) were measured to support the development and the calibration of a semi-empirical model obtained by theoretical consideration. The experimental campaign demonstrated that the fitted model is able to reproduce the real cell performance when varying the temperature, H2 concentration, CO2 concentration at anode and cathode respectively as well as CO2 CaL capture rate. Indeed, the average difference between numerical and experimental results is always below 2%. Results also demonstrated that the MCFC can be usefully considered as an efficient CO2 concentrator, with a CO2 fraction at the anode outlet that is greater than 51% on a dry basis.