Cyclic tertiary amino group containing fixed carrier membranes for CO2 separation

Fixed carrier membranes containing amino groups show attractive performance in CO 2 separation for clean energy supply and greenhouse gas reduction. However, the separation performance of fixed carrier membranes at high feed pressure is limited by the facilitated transport ability of membranes as well as the CO 2 -induced plasticization. In this work, the tertiary amino group containing fixed carrier membranes were prepared by interfacial polymerization (IP) with hexane-soluble trimesoyl chloride (TMC) and aqueous-soluble 1,4-bis (3-aminopropyl) piperazine (DAPP), N -aminoethylpiperazine (EAP) and 3,3′-diamino- N -methyldipropylamine (DNMDAm). The results show that the membrane prepared with TMC and DAPP exhibits the highest CO 2 separation performance due to efficient CO 2 facilitated transport and high plasticization resistance. Efficient facilitated transport of CO 2 in the membrane is due to the high content of cyclic tertiary amino groups which possess high stoichiometric CO 2 loading and high rate constant of amine-CO 2 reaction. Moreover, high plasticization resistance of the membrane is attributed to the appropriate stiffness of polymer chains provided by IP. The membrane prepared with TMC and DAPP shows promising applications in high-pressure fuel gas purification.