Process simulation for molten carbonate fuel cells

In the framework of electricity production from molten carbonate fuel cells (MCFC), this work presents the results obtained from steady state process simulation, coupled with a detailed dynamic model for the cell. The derivation of the model is briefly outlined, and detailed results of the simulation are reported. Macroscopic state variables of the overall system process are investigated by means of sensitivity analysis, yielding clear directions for process improvement and optimisation. The detailed steady state and dynamic simulation of the MCFC for a bi-dimensional cross flow configuration showed the importance of the state variable distribution in the cell. Both models were based on data from real plants, and the simulation conditions were selected according to real operating conditions. The process studied was a 500 kW MCFC power system based on Ansaldo fuel cell (AFC) technology. The steady state simulation revealed the main interactions among the different devices involved in the process, and the subsequent sensitivity analysis showed that there is room for improvement in electrical efficiency by increasing: i) the steam to methane ratio, ii) the pressure, and iii) the air feed ratio. The dynamic simulation yielded the quantitative response of the system to several, different, perturbations and proved to be a valid tool for determining temperature, current, and voltage profiles as a function of time, within the fuel cells.