Performance of a PEM fuel cell system fuelled with hydrogen generated by a fuel processor

Fuel cells, which have seen remarkable progress in the last decade, are being developed for transportation, as well as for both stationary and portable power generation. For residential applications the fuel cells that have the largest market segment are the PEMFC, attractive to the small utilities because they can operate on natural gas or liquefied petroleum gas, available in most metropolitan households. This study aims to foresee the performance of a PEM fuel cell generator able to provide clean, continuous power for on-site residential or light commercial applications. The fuel cell is integrated with an hydrogen generator based on steam reforming process. A commercial natural gas fuel processor has been chosen as hydrogen generator. This fuel processor contains all the elements - desulfurizer, steam reformer, CO shift converter, CO preferential oxidation (PROX) reactor, steam generator, burner and heat exchanger - in one package. The FC Generator System is able to run in parallel with the grid converting natural gas into electrical and thermal power. The whole system has been modelled by means of Aspen Plus code. The model has a modular structure in order to allow performance analysis, component by component. The modelling considers heal transfer, mass-flow rate, kinetics of steam reforming reaction and power generation. The model has been tested using the available experimental data. The efficiency of the reformer/fuel cell system has been also evaluated.