Gas permeation and sorption properties of poly(amide-12-b-ethyleneoxide)(Pebax1074)/SAPO-34 mixed matrix membrane for CO2/CH4 and CO2/N2 separation

• MMMs are fabricated using Pebax1074 and SAPO-34 for CO2/CH4 and CO2/N2 separation.
• Permeation of CO2 and N2 increases, while that of CH4 decreases by SAPO-34 addition.
• Molecular sieving mechanism SAPO-34 leads to enhanced CO2/CH4 and CO2/N2 selectivity.
• Diffusion selectivity improves due to contribution of size-selective SAPO-34.
• SAPO-34 addition increases the neat Pebax1074 membrane capacity for gas sorption.

Zeolite SAPO-34 was used for fabrication of mixed matrix membranes (MMMs) to improve the CO2/CH4/N2 gas separation performance of the neat Pebax1074 membrane. Permeability and selectivity of the MMMs were studied at different temperatures of 25–65 °C and pressures of 4–24 bars. Also sorption of different gases in MMMs was measured at 35 °C and different pressures, which showed enhanced solubility coefficients. Moreover, thermal, morphological and mechanical properties of MMMs were characterized by differential scanning calorimetry (DSC), scanning electron microscope (SEM) and tensile analysis. The results showed excellent improvement in CO2/CH4 selectivity (about 70%) and CO2/N2 selectivity (about 15%) at 20 wt% SAPO-34 loading.