Microwave synthesis of tubular zeolitic imidazolate framework ZIF-8 membranes for CO₂/CH₄ separation

The separation of CO₂/CH₄ is reported in detail by using zeolitic imidazolate framework (ZIF-8) membrane which was prepared on 3-aminopropyltriethoxysilane modified Al₂O₃ tube through microwave heating synthesis. Attributed to the preferential adsorption affinity of CO₂ over CH₄ and a narrow pore window of 0.34 nm, the ZIF-8 membrane shows high separation performances for the separation of CO₂/CH₄ mixtures. For the separation of equimolar CO₂/CH₄ mixture at 100°C and 2 bar feed (1 bar permeate) pressure, a CO₂ permeance of 1.02 × 10⁻⁸ mol/m²· s· Pa and a CO₂/CH₄ selectivity of 6.8 are obtained, which is promising for CO₂ separation.