Ion-Exchanged Silicoaluminophosphate-34 Membrane for Efficient CO2/N2 Separation with Low CO2 Concentration in the Gas Mixture

[[abstract]]The Ba form of a silicoaluminophosphate-34 (SAPO-34) zeolite membrane was synthesized and investigated for carbon dioxide (CO2)/nitrogen (N2) separation with low CO2 concentration (as low as 5%) in the feed. The effects of the separation temperature, CO2 concentration in the feed, and pressure difference on the separation performance of the Ba form of a SAPO-34 zeolite membrane were investigated. A CO2 gas permeance of 17.5 × 10–7 mol/m2·s·Pa and a CO2/N2 separation selectivity of 78 were attained for the Ba form of a SAPO-34 zeolite membrane at 100 kPa pressure difference, 303 K, and 5% CO2 concentration in the feed. With low CO2 concentration (5%) in the CO2/N2 mixture, the Ba form of a SAPO-34 zeolite membrane was efficient in CO2/N2 separation and displayed good stability for the separation performance of CO2/N2 gas mixtures, in a gas separation durability test up to a total durability test time of 58 h.[[notice]]補正完