(709d) CO2/CH4 Separation Using Adsorbent/Membrane Hybrid System

Since global warming is a very serious concern in the world, the efficient processes for CO₂ separation and clean fuel production are focused on the various fields. For more effective separation of landfill gas (CO₂/CH₄), novel concept, ?AMH? (Adsorbent/Membrane Hybrid) system, was developed. In this study, the AMH system was made of tubular-type FAU zeolite membrane packed by zeolite 5A. Then, in the AMH system, both separation and purification effects could be expected simultaneously.

The permeation and separation performance of binary mixture in the AHM system were compared to those in the FAU zeolite membrane. Since the concentration of adsorptive molecules was enriched in the packed zeolite 5A inside the AHM system, its feed partial pressure outside the AHM system (FAU zeolite membrane) became far higher than weak adsorptive molecules. As a result, the selectivity of strongly adsorptive molecules could be increased. In addition, the effects of stage cut and sweeping gas flow rate on the AMH system were investigated. In the AMH system, the inside propagation profiles by different adsorption affinity gave a significant contribution to the separation. And, the separation factor in the AMH system was higher than the membrane system. The mathematical model and simulator for the AMH system, considering axial and radial simultaneously, were successfully developed. The permeation and separation of multi-component permeation in the AMH system were well-predicted by the combined packed bed model and tubular type membrane model.