(400m) Greener Ethylene Production Via Chemical Looping
- Conference: AIChE Annual Meeting
- Year: 2017
- Proceeding: 2017 Annual Meeting
- Group: Particle Technology Forum
- Time: Tuesday, October 31, 2017 - 3:15pm-4:45pm
We have identified, in our previous work, that Mg6MnO8, a mixed oxide with a cation deficient rocksalt structure, is an excellent model redox catalyst for ODH. When promoted with alkali salts, changes in the bulk and near surface properties of the Mg/MnO system help produce ethylene with exceptional selectivity by suppressing deep oxidation of ethane or ethylene. The facile combustion of hydrogen favored by the promoted redox catalyst leads to high ethylene yield and provides the heat required for the endothermic dehydrogenation reaction. In the current study, CL-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 80% reduction in both the overall energy demand and CO2 emissions. The exothermic nature of the regenerator and elimination of the steam requirement lead to major reductions in the upstream energy consumption. Kinetic modeling using CHEMKIN-PRO® is performed to determine the effect of gas phase and surface reactions on the CL-ODH product distributions. The proposed CL-ODH process in the context of circulating fluidized bed operations is also discussed.