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

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 CO2 permeability, CO2/CH4, and CO2/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 CO2 permeability of 1400.0%, as well as CO2/CH4 and CO2/N-2 selectivity of 461.1% and 1344.4%, respectively at 7 bar and 25 degrees C, compared to the pristine membrane. The significant improvement in CO2/CH4 and CO2/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.