Polymeric membranes containing silver salts for propylene/propane separation

the separation of olefin/paraffin mixtures is one of the most important processes of the chemical industry. this separation is typically carried out by distillation, which is an energy and capital intensive process. one promising alternative is the use of facilitated transport membranes, which contain specific carrier agents in the polymer matrix that interact reversibly with the double bond in the olefin molecule, promoting the simultaneous increase of its permeability and selectivity. in this study, polyurethane (pu) membranes were prepared using two different silver salts (triflate and hexafluorantimonate). the membranes were structurally characterized and their performance for the separation of propylene/propane mixtures was evaluated. the results of the characterization analyses indicated that the triflate salt was the most efficient carrier agent. the membranes containing this salt showed the best performance, reaching an ideal selectivity of 10 and propylene permeability of 188 barrer.