(593b) CO2 Separation Properties of [Bmim][Tf2N]-PVDF Blend Composite Membranes

[bmim][Tf₂N]-PVDF blend composite membranes were fabricated with polypropylene (PP) ultrafiltration membranes as support layers using the solvent evaporation technique that show a best CO₂ permeance of 97.8 GPU with maximum CO₂/N₂ and CO₂/CH₄ selectivity of 36.2 and 23.8, in which the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([bmim][Tf₂N]) was dispersed in poly(vinylidene fluoride) (PVDF) matrix. [bmim][Tf₂N] with high CO₂ permeability plays a crucial role in CO₂ separation. Membrane permeances for CO₂, N₂, and CH₄ and the CO₂/N₂ and CO₂/CH₄ selectivity were evaluated with three kinds of pure permanent gases (CO₂, N₂, CH₄). The CO₂ and CH₄ permeabilities of the blend composite membranes are approximately predicted by Maxwell model. The gas separation performance for CO₂/N₂ and CO₂/CH₄ of most of these blend composite membranes surpass the Robeson’s 2008 upper bound limit, and are stable at trans-membrane pressure up to 0.7 MPa. Therefore, they are promising materials for CO₂ capture from flue gas and natural gas.