Mixed matrix membrane encompassing of cellulose triacetate and ZIF‐90 for CO2 separation from CH4 and N2

Abstract In this work, we have successfully synthesized a series of mixed matrix membranes (MMMs) via the solution casting method by incorporating different loadings of ZIF‐90 into cellulose triacetate (CTA). The crystallinity, morphology, and functional groups of the filler and resultant membranes were analyzed using x‐ray diffraction (XRD), scanning electron microscope (SEM), and attenuated total reflectance‐Fourier transform infrared (ATR‐FTIR) techniques. The gas permeation results revealed that CO 2 permeability, CO 2 /CH 4 , and CO 2 /N 2 ideal selectivities were enhanced substantially in the presence of ZIF‐90 in the CTA polymer matrix. The current study showed that CTA incorporated with 1.5 wt% of ZIF‐90 filler exhibited an enhancement in CO 2 permeability of 1400.0%, as well as CO 2 /CH 4 and CO 2 /N 2 selectivity of 461.1% and 1344.4%, respectively at 7 bar and 25°C, compared to the pristine membrane. The significant improvement in CO 2 /CH 4 and CO 2 /N 2 separation performance of ZIF‐90‐(1.5)‐CTA MMM compared to the pure CTA membrane suggests a feasible and practical approach for potential carbon sequestration using MMM in natural gas purification and pre‐combustion flue gas industrial applications. Highlights CTA‐based MMMs were synthesized with varied ZIF‐90 loadings. ZIF‐90 enhanced CO 2 separation in gas purification. ZIF‐90 exhibited strong compatibility with the CTA matrix. 1.5 wt% ZIF‐90 MMM showed superior performance.