System calculation of integrated coal gasification/molten carbonate fuel cell combined cycle: Reflection of electricity generating performances of practical cell

Materials and heat balance of integrated coal gasification/molten carbonate fuel cell (IG/MCFC) combined system are calculated considering the electricity generating performance of the practical cell. The considered gas conditions that are required to stabilise the electricity generation of MCFCs are the non-carbon deposition condition, the lower limit of H2 concentration at the anode outlet of 1 mol% and the upper limit of CO2 partial pressure on the cathode inlet gas of 0.1 MPa. The anode gas recycling system and the anode heat exchange system have been studied supposing a not-equilibrium state of water–gas shift reaction in anode gas channel. From the investigation on carbon deposition at the anode inlet gas, the anode gas recycling system requires approximately 80% re-circulation of the anode outlet gas, whereas the anode heat exchange system needs 60% humidity of the fuel gas. The fuel utilisation in the anode gas recycling system should be set lower than in the anode heat exchange system. The net thermal efficiency of the anode gas recycling system has a peak for CO2 partial pressure where the net thermal efficiency of the anode heat exchange system increases as the CO2 partial pressure of the cathode gas decreases.