Researchers at the Dept. of Chemical Engineering, University of Texas at Austin (edlinks.che.com/5827-547) have developed a rubbery membrane that can be used purify hydrogen. The membrane, based on ethylene oxide polymers, is 40 times more permeable to CO2 than H2, which facilitates the removal of CO2 while allowing the H2 to remain compressed at high pressure. This has the advantage over commercially available, H2-permeable membranes, which require compressors to boost the purified H2’s pressure for petroleum-refining applications. The researchers say the membrane may also have applications for producing H2 for future fuel-cell vehicles.