Oxidative Dehydrogenation of Ethane over a Perovskite-Based Monolithic Reactor

The oxidative dehydrogenation (ODH) of ethane has been investigated in a short contact time reactor constituted by a LaMnO3-based monolithic catalyst with a honeycomb morphology. Using an ethane-air mixture with a C2H6/O2 ratio = 1.5 and a preheat temperature ranging from 250 to 400°C results in a 55% ethylene yield, a value even higher than those reported in the same experimental conditions over Pt based catalysts. By investigating the effect of the experimental conditions, we found that the major role of increasing the feed flow rate and decreasing the C2H6/O2 ratio is to raise reactor temperature and consequently the conversion of ethane. The selectivity to ethylene seems to increase with increasing temperature too, but only up to about 950°C. At higher temperatures, further degradation of ethylene to C2H2 and CH4 occurs. We also found that CO2 is the second main product of ethane oxidation and that the perovskite catalyst is intrinsically active in ODH unlike Pt monoliths.