Hyperaging Tuning of a Carbon Molecular-Sieve Hollow Fiber Membrane with Extraordinary Gas-Separation Performance and Stability.

This study reports 6FDA:BPDA-DAM polyimide-derived hollow fiber carbon molecular-sieve (CMS) membranes for hydrogen and ethylene separation. Since H /C H selectivity is the lowest among H /(C -C ) hydrocarbons, an optimized CMS fiber for this gas pair is useful for removing hydrogen from all-cracked gas mixtures. A process we term hyperaging provides highly selective CMS fiber membranes by tuning CMS ultramicropores to favor H over larger molecules to give a H /C H selectivity of over 250.