Pebax-Modified Cellulose Acetate Membrane for CO2/N2 Separation

Carbon dioxide (CO2) release from the exhaust gas streams of power plants that burn fossil fuels contributes the most emission of this gas, which includes more than half of the greenhouse effects. Thus, the separation of CO2 from exhaust gases is one of the main environmental concerns. Membrane technology, due to many advantages, has attracted many research attentions among the various gas separation technologies. In this study, separation performance of cellulose acetate (CA) membrane as the most famous commercial membrane used to separate CO2, improved through the blending method. In this regard, block co-polymer (polyether block amide), as a trade name of Pebax (Pebax® 1657), which has a proper efficiency in separation of CO2 has been used. Cellulose acetate/Pebax blend membranes are prepared by solution casting/solvent evaporation method and their performance in CO2 separation from N2 was studied. The morphologies were also being investigated using SEM, FTIR, DSC and XRD. Gas permeability results, showed that CO2 permeability in CA membrane increases more than 25% and its equivalent CO2/N2 ideal selectivity rises about 59% with the increase in Pebax content up to 8 wt.%.