Oxidative dehydrogenation of ethane to ethylene over Sr-promoted La<SUB>2</SUB>O<SUB>3</SUB> catalyst supported on low surface area porous catalyst carrier

Oxidative dehydrogenation of ethane (ODE) to ethylene over Sr-promoted La<SUB>2</SUB>O<SUB>3</SUB> (Sr/La = 0.0, 0.03, 0.3, 2.0 and 10.0) supported on a commercial low surface area porous, inert catalyst carrier SA-5205 ( Sr-La<SUB>2</SUB>O<SUB>3</SUB> loading = 16 &#177; 1.5 wt% ) in presence of steam (steam/C<SUB>2</SUB>H<SUB>6</SUB> = 1.0) at different temperatures (700- 850&#176;C ), C<SUB>2</SUB>H<SUB>6</SUB>/O<SUB>2</SUB> ratios ( 4.0 - 8.0 ) in the feed and gas hourly space velocities (50723 - 201,240 cm<SUP>3</SUP>g<SUP>1</SUP>.h<SUP>1</SUP>) has been studied. The supported Sr- La<SUB>2</SUB>O<SUB>3</SUB> catalysts have been characterized for their surface area and also for their basicity distribution by the TPD of CO<SUB>2</SUB> from 50 to 950&#176;C. Among the supported Sr-La<SUB>2</SUB>O<SUB>3</SUB> catalysts, the one with Sr/La = 0.3 showed best performance in the oxidative dehydrogenation of ethane to ethylene. Moreover, high selectivity (&gt;80%) for C<SUB>2+</SUB> olefins at 50-70% conversion of ethane could be obtained at very high space velocity without coke deposition on the catalyst at 800- 850&#176;C. When the reaction temperature and or C<SUB>2</SUB>H<SUB>6</SUB>/O<SUB>2</SUB> ratio is increased, the heat produced in the process is decreased markedly because of the occurrence of thermal cracking of ethane ( which is endothermic) to a larger and larger extent, simultaneously with the exothermic oxidative ethane conversion, thus making the process nearly thermoneutral or mildly exothermic/endothermic by manipulating the process conditions