Preparation and characterization of acrylonitrile-butadiene-styrene/poly (vinyl acetate) membrane for CO2 removal

CO2 removal from different gas streams via the polymeric membranes has been propounded as an important issue in greenhouse gas emissions control, natural gas upgrading, and enhanced oil recovery. Here, polymeric blend membranes were prepared from acrylonitrile-butadiene-styrene (ABS) and poly vinyl acetate (PVAc), and their CO2/N-2 and CO2/CH4 separation characteristics were investigated. The influence of different PVAc contents on gas separation performance and the effect of pressure, ranging from 1 to 8 bar, on CO2 permeability were studied. Furthermore, the morphology of the membranes was analyzed by FTIR, XRD, DSC and SEM. It was shown that the highest CO2 permeability of 5.72 Barter for the membrane containing 10 wt.% PVAc, the highest CO2/CH4 selectivity was 29 in 20 wt.% PVAc and CO2/N-2 was 40.41 in 30 wt.% PVAc contents. These results comprised from different effective factors such as PVAc acetate polar groups, compactness in polymer matrix at the presence of high molecular weight PVAc, and the acrylonitrile and flexible butadiene contents of ABS. Furthermore, in the transmembrane pressure of 2-8 bar the CO2 permeability approximately descended with the pressure increase for PVAc content of 0-40 wt.%, and it ascended for 50-60 wt.%. Generally, the prepared membranes can be taken into account as better membranes for CO2/N-2 separation than CO2/CH4. (C) 2011 Elsevier B.V. All rights reserved.