Oxidative conversion of propane to propylene and ethylene over a V2O5/CeO2/SA5205 (V:Ce = 1:1) catalyst, with or without steam and limited 02, has been studied at different temperatures (700-850degreesC), C3H8/O-2 ratio (4.0), H2O/C3H8 ratio (0.5) and space velocity (3000 cm(3) g(-1) h(-1)). The propane conversion, selectivity for propylene and net heat of reaction (DeltaHr) are strongly influenced by the reaction temperature and presence of steam in the reactant feed. In the presence of steam and limited O-2, the process involves a coupling of endothermic thermal cracking and exothermic oxidative conversion reactions of propane which occur simultaneously. Because of the coupling of exothermic and endothermic reactions, the process operates in an energy-efficient and safe manner. The net heat of reaction can be controlled by the reaction temperature and concentration of O-2. The process exothermicity is found to be reduced drastically with increasing temperature. Due to the addition of steam in the feed, no coke formation was observed in the process. (C) 2003 Elsevier Ltd. All rights reserved.