(532b) Analysis of a Cyclic Redox Process for Oxidative Dehydrogenation of Ethane
- Conference: AIChE Annual Meeting
- Year: 2016
- Proceeding: 2016 AIChE Annual Meeting
- Group: Process Development Division
- Time: Wednesday, November 16, 2016 - 12:50pm-1:10pm
Mn-based oxides have been shown to be effective as redox catalysts for the ODH of ethane. Selective combustion of hydrogen to water, over the redox catalyst, shifts the equilibrium towards ethylene and also provides the heat required for the endothermic dehydrogenation reaction. In this work, the ODH of ethane is modeled using ASPEN Plus® and is compared with a conventional stream cracking process. Results show that CL-ODH with 85% ethane conversion provides over 70% reduction in the overall energy demand with >75% reduction in the overall CO2 emissions. The exothermic nature of the regenerator and elimination of the steam requirement lead to major reductions in the upstream energy consumption. Combustion of hydrogen further reduces the downstream separation loads by >20%, with >25% drop in the compression work. For every tonne of ethylene produced, steam cracking requires an external fuel input equivalent to 1.5 GJTh, whereas the CL-ODH results in surplus fuel energy in excess of 6 GJTh. Increase in single-pass ethane conversion further increases the energy savings. Preliminary results from CHEMKIN-PRO® are in close agreement with literature values in terms of product compositions for ethane cracking. Addition of surface kinetics of the redox catalyst towards hydrogen combustion provides further understanding of the dependence of product output on the process conditions.