Propylene Enrichment via Kinetic Vacuum Pressure Swing Adsorption Using ZIF-8 Fiber Sorbents.

This work presents the synthesis, characterization, and implementation of ZIF-8/cellulose acetate fiber sorbents for the cyclic kinetic adsorption separation of an equimolar propane/propylene feed. These fiber sorbents are packed as structured mass-transfer contactors and employed in a two-bed vacuum pressure swing adsorption cycle without propylene product purge. The unoptimized adsorption cycle process produces a high-pressure product of up to 81% propane purity at 31% recovery at 0 °C. The effects of adsorption step time, temperature, and feed rate are investigated and presented as a purity/recovery trade-off. This work represents the first successful demonstration of a metal-organic framework fiber sorbent in a pressure swing adsorption cycle and the first use of metal-organic frameworks in a kinetic separation cycle.