Hydrogen production by decomposition of light paraffins over Ni/Ca/carbon catalysts in the absence or presence of impurities

The decomposition of light paraffins was investigated using a Ni/Ca/carbon- based catalyst and an Ag-Pd membrane-type reactor (PMR). The use of this co mbined system resulted in the formation of smaller amounts of methane (< 10 % yield) than in fixed-bed reactor systems (10-50% yield). The initial acti vity of CH4 decomposition seems to be little affected by these impurities s uch as NO, SO2, CO2, and H2O. The activity in the presence of SO2, however, was found to be completely lost after 250 min.