HOMOGENEOUS AND HETEROGENEOUS CONTRIBUTIONS TO THE CATALYTIC OXIDATIVE DEHYDROGENATION OF ETHANE

The oxidative dehydrogenation of ethane to ethene has been studied in a quartz reactor in the absence and in the presence of a range of MgO-based catalysts using a variety of gas compositions over a range of temperatures. The results show that under optimum conditions the non-catalysed reaction can be very efficient and selective. At a temperature of 600-degrees-C, using an ethane/air ratio of 1:2, a conversion of 45% was achieved at a selectivity of 73.7%, corresponding to a percentage yield of ethene of 33% and a space-time yield of ethene of 15.8 mmol/cm3 h. It was observed that none of the catalysts tested under comparable conditions gave such high yields. Reasons for this difference are discussed. Comparison with published results on the catalytic oxidative dehydrogenation of ethane suggest that the non-catalysed gas-phase reaction is competitive with the best available catalysts.