MASS AND ENERGY BALANCES IN A MOLTEN-CARBONATE FUEL-CELL WITH INTERNAL REFORMING

The direct internal reforming molten-carbonate fuel cell (DIR-MCFC) can be proposed as a cogeneration system (heat + electricity). The influence of several operating parameters on the mass and energy balances of a 10 kW power plant has been investigated by using a mathematical model. The temperature, the steam/carbon ratio, the electrical power and the useful heat fraction have been found to be relevant parameters for optimizing both the energy and the exergy efficiencies. The results indicate that the performance of the system is improved at higher temperatures (973 K) and at fuel utilization (U(f)) in the range of 45 to 70%. At lower U(f) values the system works endothermically, because the steam reforming reaction prevails and for U(f) > 70%, a decrease of the efficiencies is produced by the electrode overpotentials and the ohmic losses.