NaA zeolite/carbon nanocomposite thin films with high permeance for CO2/N2 separation

Novel NaA zeolite/carbon nanocomposite thin films were successfully prepared on a porous α-Al2O3 substrate by dip-coating method. The prepared films were characterized by XRD, SEM and single gas permeation tests. NaA zeolite/carbon nanocomposite thin films exhibited the ideal separation factor of CO2/N2 of 6.04 with the carbon dioxide permeance of 3.39 × 10−7 mol Pa−1 m−2 s−1 at room temperature and 100 kPa, which was two orders of magnitude higher than that of pure carbon membrane reported by previous literature. The observed adsorption isotherms indicated that the incorporation of zeolite NaA crystal improved the CO2 adsorption ability of carbon materials, and decreased its N2 adsorption ability. The ideal permselectivity of CO2/N2 of carbon/NaA composite films was 6.04, higher than the ideal adsorption selectivity, probably because the small molecule of CO2 diffused faster than N2. From the SEM images, the thickness of nanocomposite films was 1–2 μm, which was helpful to decrease the resistance and increase the flux of gas permeance.