Effects of CO2 on a High Performance Hollow-Fiber Membrane for Natural Gas Purification

A 6FDA-based, cross-linkable polyimide was characterized in the form of a defect-free asymmetric hollow-fiber membrane. The novel membrane was cross-linked at various temperatures and tested for natural gas purification in the presence of high CO 2 partial pressures. The cross-linked membrane material shows high intrinsic separation performance for CO 2 and CH 4 (selectivity ∼49, CO 2 permeability ∼161 barrer, with a feed at 65 psia, 35 °C, and 10% CO 2 ). Cross-linked asymmetric hollow-fiber membranes made from the material show good resistance to CO 2 -induced plasticization. Carbon dioxide partial pressures as high as ∼400 psia were employed, and the membrane was shown to be promisingly stable under these aggressive conditions. The performance of the membrane was also analyzed using the dual-mode sorption/transport model.