Potential of Polymer Membranes for Xenon Recovery from Medical Waste Gas Mixtures

This work is devoted to the evaluation of xenon permeability coefficients for a wide range of polymeric membrane materials, as well as the primary experimental verification of the calculation results for materials used in the production of gas separation membranes. The solution of the problem of O₂/Xe mixture separation as a base for xenon-containing waste medical gas mixtures where it is possible to recover xenon for its reuse has been emphasized. The xenon permeability coefficients have been evaluated using a correlation approach that relates the molecular properties of a gas to gas permeability, and available literature data on the permeability of other gases. The results obtained make it possible to distinguish two main groups of membrane polymers in the Robeson diagram for O₂/Xe gas pair: xenon-selective (polysiloxane-based rubbers and highly permeable functional polyacetylenes) and oxygen-selective (polyimides, PIMs, perfluorinated polymers). Industrial composite membrane MDK with a selective layer of silicone copolymer and laboratory composite membranes based on PSf and PVTMS have been experimentally investigated. The obtained data demonstrate satisfactory convergence of the experimental values with the estimated ones. Based on the results obtained, MDK membrane can be recommended as xenon-selective for xenon recovery (α(Xe/O₂) = 3.1).