Mixed matrix membranes based on MIL-100(Cr) for removal of N₂ from CH₄

Two series of mixed matrix membranes (MMMs) have been synthesized via in situ UV polymerization for the removal of N₂ from CH₄. MIL-100(Cr) particles activated at different temperatures were used as fillers. MIL-100(Cr) activated at 150°C with CH₄-selective adsorption was incorporated with poly(ethylene oxide)-based polymer to improve the CH₄/N₂ separation performance, and that activated at 250°C with N₂-selective adsorption and diffusion was incorporated with fluoropolymer to improve the N₂/CH₄ separation performance. The effects of the filler loadings on the gas permeation and separation performances were investigated. The optimum MMMs with 5 wt.% loading of MIL-100(Cr) activated at 150°C exhibited a 70% increased CH₄/N₂ permselectivity of 5.0 with a 37% increased CH₄ permeability of 11.2 Barrer (tested at 0.2 MPa and 35°C). The optimum MMMs with 5 wt.% loading of MIL-100(Cr) activated at 250°C exhibited a 106% increased N₂ permeability of 71.5 Barrer with an 89% increased N₂/CH₄ permselectivity of 1.9.