Estimating performance degradation in reformers for PAFC power plants by using increases in steam-reformed and burner-exhaust gas temperatures

We simulated the performance degradation in a reformer for phosphoric-acid-fuel-cell (PAFC) power plants caused by deterioration of the catalyst loaded in the reformer. We found that the temperatures of the catalyst bed, steam-reformed gas, reformer-tube outer-wall, and burner-exhaust gas rise as the catalyst deteriorates. Increases in the steam-reformed and burner-exhaust gas temperatures at the reformer outlet proved to be the most useful parameters for estimating the drop in reformer performance caused by catalyst deterioration because they could be easily measured during power generation. These temperatures rise and the methane-conversion rate decreases as the catalyst deteriorates, By comparing the simulation results with measurements taken for a 200 kW PAFC power plant, we found that increases in the steam-reformed and burner-exhaust gas temperatures at the reformer ontlet, instead of the methane-conversion rate, can be used as parameters for estimating the reformer-performance degradation, and that the steam-reformed-gas temperature is the better parameter of the two.