(401k) The Role of Adsorbent and Support Layer in Ionic Liquid Modified Mixed Matrix Membranes for CO2/N2 Separation

Rising atmospheric carbon dioxide (CO₂) levels since the Industrial Revolution have made it crucial to reach net zero emissions by 2050 to limit global warming to 1.5°C. Membrane separation is a promising technique for CO₂ capture due to many advantages over conventional technologies, such as lower capital cost, scalability, low energy consumption and low maintenance. Mixed matrix membranes have gained attention due to their superior separation performance compared to polymeric membranes. This paper focuses on the synthesis and characterization of inorganic adsorbent and chlorinated protic ionic liquid (CPIL) based mixed matrix membranes (MMMs). The permeation and selectivity of these MMMs were measured using a lab-scale single gas permeation setup, with and without humidity, to investigate the effect of moisture on separation performance and on membrane aging. Five polymeric supports (cellulose polymer – PP, polydimethyl siloxane – PDMS, polyether sulfone – PES, polytetrafluoroethylene – PTFE, polyacrylate – PA) and three adsorbents (13X, MCM-41, SAPO-34) were tested in combination with a dimethylaminopropylamine based CPIL developed in a previous publication, to determine the optimal MMM combinations for both dry and wet conditions. The maximum CO₂/N₂ selectivity of 44.5 was achieved by SAPO-34/PES under wet conditions, with a very high CO₂ permeability of 4.6 ×10⁸ Barrer. Under dry conditions, MCM-41/PTFE demonstrated the highest CO₂/N₂ selectivity of 2.5 and CO₂ permeability of 3.9 ×10⁷ Barrer.