High‐Performance Polymer Membranes for Natural‐Gas Sweetening

Abstract

Rubbery membrane materials based on high-solubility selectivity for the removal of CO2 from natural gas are made from highly branched, crosslinked poly(ethylene oxide) (XLPEO) which exhibits high CO2/CH4 selectivity (αequation/tex2gif-inf-4.gif) even in the presence of high activities of plasticizing agents (e.g., CO2 and higher hydrocarbons). Decreasing temperature improves the separation performance. Many conventional glassy gas separation materials, including polyimides such as 6FDA-mPD, lose selectivity when strongly plasticized (see Figure).