The adsorption dynamics of N2, O2, and Ar in kinetic separation bed with CMS and equilibrium separation bed with zeolite 13X were investigated by using dried air as a feed. In the CMS bed initially saturated with He, Ar was the first breakthrough component showing a small roll-up and N2 followed at a very close interval. Then, the breakthrough of O2 occurred with a broad roll-up due to its fast diffusion rate and the relatively slow diffusion rate of N2. In the zeolite 13X bed initially saturated with O2, the breakthrough of Ar first occurred with roll-up owing to the strong adsorption of N2, then the breakthrough of N2 followed after a very short interval. Based upon these results, the cyclic adsorption dynamics of the zeolite 13X VSA for air bulk separation and CMS PSA for oxygen purification were studied. The five-step two-bed O2 VSA with zeolite 13X produced O2 of over 90% purity with high recovery. The MTZ variation of N2 during the adsorption and vacuum steps was described in detail. In the case of the six-step two-bed PSA process for O2 purification, O2 of 99.8+% purity could be produced from the binary mixture (O2/Ar-95:5 vol.%). The dynamic adsorption behaviors were investigated by using a concentration-dependent rate model incorporated with mass, energy, and momentum balances. The model reasonably predicted the adsorption dynamics at the equilibrium and kinetic separation beds.
Bibliographical noteFunding Information:
The financial support of the Carbon Dioxide Reduction and Sequestration R & D Center (C002-0103-001-1-0-0) is gratefully acknowledged.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Surfaces and Interfaces