Facilitated transport of CO2 through Co(II)-S-EPDM ionomer membrane

A new facilitated transport ionomer membrane was prepared by incorporating Co(II) ions, as fixed carrier, into the sulfonated ethylene-propylene-diene terpolymer, Co(II)-S-EPDM, and was applied for preferential transport of carbon dioxide rather than nitrogen from CO2/N-2 gas streams. The membranes were also characterized by using the FTIR, SEM and TG/DSC analyses. Furthermore, single gas permeation experiments at different membrane thicknesses (30 and 200 mu m), sulfonic group contents (0.1 and 0.2 mmol of sulfonic acid (SO3H)/g EPDM), feed gas pressures (2-10 bar) and temperatures (30-50 degrees C) were carried out. The permeation results of the dense Co(II)-S-EPDM ionomer membranes show that the incorporation of Co(II) ions into the sulfonated EPDM ionomers increases the permeance of both CO2 and N-2 gases. Moreover, due to facilitated CO2 transport by the carriers, the CO2/N-2 selectivity is also increased. These are mainly attributed to the formation of polymer coordinate complexes in the ionomer. (C) 2014 Elsevier B.V. All rights reserved.