Efficient facilitated transport PETIM dendrimer-PVA-PEG/PTFE composite flat-bed membranes for selective removal of CO2

Abstract

Development of membranes that provide high permeance and selectivity for separation of CO2 gas is important. We describe herein the development of polymer-dendrimer composite membranes, wherein the influence of dendrimer generations on the membrane CO2 permselectivities is investigated. Poly(vinyl alcohol) (PVA) – poly(ethylene glycol) (PEG), cross-linked with glutaraldehyde (GA) membranes, incorporated further with amine-rich poly(ether imine) (PETIM) dendrimer generations 1–3, are studied by molecular dynamics simulations and experimental methods. Simulations reveal molecular level details of the affinity of CO2 to the membrane among dendrimer generations. Systematic experimental studies by varying several parameters prove that the composite membrane containing a third generation dendrimer approaches the Robeson trade boundary curve very closely, with optimal CO2 permeance and CO2/N2 gas pair selectivity of 6.2 × 10−9 mol m−2 s−1 Pa−1 and 56, respectively, at a feed pressure of 2 × 105 Pa and 30 °C. The membranes possess long-term stability of ca. 200 h. A comparison with known facilitated membrane systems reveals that the third generation dendrimer-based composite membrane exhibits the most optimal CO2 permeance and CO2/N2 selectivity.