Solid-Liquid-Polymer Mixed Matrix Membranes for Gas Separation: Silicone Rubber Membranes Filled with NaX and KY Zeolites Adsorbed PEG

Abstract

Carbon dioxide (CO₂) is one of the major constituents of natural gas and biogas. The presence of high CO₂ content causes some serious problems including reduction of heating value and corrosion of equipment’s surface. Additionally, CO₂ emission is the main issue of the greenhouse effect. In consequence of these problems, membrane technologies have drawn much attention as potential techniques for gas separation. mixed matrix membranes (MMMs) have been studied and developed to provide the synergistic effect of inorganic and organic materials on membranes. In this study, PEG/NaX:KY/SR mixed matrix membranes (PZS MMMs) were prepared by the solution casting method using NaX and KY zeolites as the solid fillers, PEG as the liquid additive, and silicone rubber as the continuous phase. The fabricated PZS MMMs were evaluated through permeance and selectivity for the single gas measurements using a membrane testing unit at room temperature and a pressure of 50 psig. The combination of NaX and KY zeolites showed the improvement in gas separation CO₂/CH₄ gas separation. The PZS MMM with NaX/KY zeolite mass ratio of 0:1 yielded the highest CO₂ permeance and CO₂/CH₄ selectivity among the solid-polymer MMMs prepared. KY zeolite was more effective than NaX zeolite in term of higher CO₂ permeability and CO₂/CH₄ selectivity due to the basicity. PEG adsorbed into the zeolites effectively influenced the gas separation performance, CO₂ permeance and CO₂/CH₄ selectivity in comparison between solid-polymer and solid-liquid-polymer mixed matrix membranes.