Effect of Stabilization Conditions on the Fabrication of Carbon Membranes for CO2 Separation

Preparation of carbon membranes has rapidly attracted much attention in gas separation processes because of thermal and chemical stabilities and exhibit superior separation performance. Carbon hollow fiber membranes (CHFM)s derived from polymer blend of polyetherimide (PEI) and polyvinylpyrrolidone (PVP) were extensively prepared through stabilization under air atmosphere followed by carbonization under N2 atmosphere. The effects of the stabilization temperature on the morphological structure and gas permeation properties were investigated by means of scanning electron microscopy (SEM) and single gas permeation system. Experimental results indicate that the transport mechanism of small gas molecules of N2, CO2, and CH4 is dominated by the molecular sieving effect. Based on morphological structure and gas permeation properties, an optimum stabilization condition for the preparation of CHFM derived from PEI/PVP was found at 300°C under air atmosphere. The selectivity of about 55 and 41 for CO2/CH4 and CO2/N2, respectively, were obtained.