Membrane Selectivity vs Permeance

  • Published on:  Sunday, February 6, 2022
  • The separations of CO2/H2, CO2/CH4, CO2/N2 and other gaseous mixtures are of practical importance for CO2 capture and other applications in the processing industries. Use of membranes with microporous layers of zeolites, metal organic frameworks (MOFs), and zeolitic imidazolate frameworks (ZIFs) offer considerable promise for use in such separations. In view of the extremely wide variety of available microporous structures, there is a need for a systematic screening of potential candidates in order to obtain the best permeation selectivities, Sperm. The permeation selectivity is a product of the adsorption selectivity, Sads, and the diffusion selectivity, Sdiff. We have identified two different classes of materials that have different permeation characteristics.