Separation and Purification Technology vol:75 issue:1 pages:15-21
Polyimide (PI) based membranes are commercially attractive for CO2/CH4 separations due to their high selectivity and permeance. However, PI membranes prepared from commercially available Matrimid(R) become unsuitable for industrial applications at high CO2 partial pressure due to plasticization. Blending appropriate polymers with Matrimid(R) is known to increase this critical plasticization pressure. However, most open literature studies are based on thick symmetric films. Moreover, stability of the membranes as a function of temperature and composition of binary gas mixtures has not systematically been studied yet. The study so far of single gas feeds with thick dense membranes strongly limits the relevance with respect to the actual industrial scale separations.