Autothermal Gas-Phase Oxidative Dehydrogenation of Ethane to Ethylene at Atmospheric Pressure
Hassan J. Dar, Hugo A. Jakobsen, Kumar R. Rout, Klaus Jens, De Chen
Abstract
The autothermal gas-phase oxidative dehydrogenation of ethane (ODHE) in a tubular reactor was analyzed by one-dimensional (1D) and two-dimensional (2D) reactor simulations coupling with a detailed kinetic model, where effects of the reactor configuration and operating conditions such as the C2H6/O2 ratio, inlet temperatures, and oxygen distribution on the ethylene yield were analyzed and optimized. An inlet temperature of 1023 K and a C2H6/O2 ratio of 3.3 were found as the best-operating conditions for the gas-phase oxidative dehydrogenation of ethane with autothermal operations. Multiple injections of oxygen feed are analyzed and used to optimize the ethylene yield using an overall C2H6/O2 ratio of 3.3. An ethylene yield of 57.8% (C2H4 selectivity 70.2%) is predicted for an inlet temperature of 1023 K. The results demonstrated the importance of small gradients of oxygen and temperature in the reactor for both the axial and radial directions to gain a high ethylene yield. A multitubular reactor with a relatively small diameter and multiple axial oxygen injections is recommended.