Reaction coupling of diethylbenzene dehydrogenation with water-gas shift over alumina-supported iron oxide catalysts

Starting from the thermodynamic analysis of the coupling of diethylbenzene (DEB) dehydrogenation to divinylbenzene (DVB) with reverse water-gas shift, the dehydrogenation of DEB in the presence of carbon dioxide over alumina-supported iron oxide catalysts was carried out at 450-650 degreesC under atmospheric pressure with CO2/DEB mote ratio of 10-70 and DEB liquid space velocity (LHSV) of 0.2-1.2 h(-1). The effects of reaction temperature, LHSV, CO2/DEB ratio, as well as iron loading and addition of promoters upon DEB conversion and DVB selectivity were investigated. It was revealed that the yield of DVB and ethylstyrene (EST) could be greatly improved by the reaction coupling due to the simultaneous elimination of the hydrogen produced in the dehydrogenation by reverse water-gas shift. A typical result with EST + DVB selectivity of 90.3%, DVB yield of 43.9% and EST yield of 38.0% was obtained at 550 degreesC with DEB LHSV of 0.4 h(-1) and CO2/DEB mole ratio of 40. (C) 2003 Elsevier B.V. All rights reserved.