A study of the mass transfer of CO2 through different membrane materials in the membrane gas absorption process

The mass transfer of carbon dioxide through hydrophobic membrane materials into aqueous solutions of monoethanolamine has been studied. Microporous polypropylene, polytetrafluoroethylene and polyvinylidene fluoride hollow fiber membranes were compared. Membranes were characterized before and after use and wetting studies showed that the mass transfer resistance increased by 15% for polypropylene after 45 hours. Wetting may be due to membrane degradation as a result of contact with the solvent. This study highlights the need to choose membrane-solvent systems that utilize a low cost membrane that remains unwetted by the solvent over long periods and when subjected to reasonable solvent-side pressures.