AgBF4/[emim][BF4] supported ionic liquid membrane for carbon monoxide/nitrogen separation

In this paper,AgBF/[emim][BF] supported ionic liquid membranes(SILMs) were prepared successfully for CO/Nseparation using nitrogen pressure immobilization procedures.The incorporation of AgBFcould decrease membrane weight loss,improve the pressure-resistant ability,and keep the critical pressure(0.45 MPa) of the SILMs.The high viscosity and undissolved Ag BFsolids in membrane liquid would disturb gas molecular transport through membrane and give rise to the gas transport resistance.Therefore,the gas permeability decreased remarkably with increasing AgBFcarrier content in the membrane.When the molar ratio of AgBFto [emim][BF] increased from 0:1 to 0.3:1,the CO/Nselectivity of the SILMs showed a great increase from ～1 to ～9 at 20 °C and 0.4 MPa,suggesting that AgBFwas an effective carrier for CO facilitated transport.The permeabilities of Nand CO increased at higher transmembrane pressure,indicating that molecular transport would dominate the transport process at high pressure.The temperature-dependent gas permeability followed the Arrhenius equation.Moreover,the differences between the activation energies of CO and Nbecame larger after introducing AgBF,resulting in more obvious decrease in the CO/Nselectivity at higher operating temperature.