Small-Pore Zeolite Membranes: A Review of Gas Separation Applications and Membrane Preparation

Abstract

There have been significant advancements in small-pore zeolite membranes in recent years. With pore size closely related to many energy- or environment-related gas molecules, small-pore zeolite membranes have demonstrated great potential for the separation of some interested gas pairs, such as CO2/CH4, CO2/N2 and N2/CH4. Small-pore zeolite membranes share some characteristics but also have distinctive differences depending on their framework, structure and zeolite chemistry. Through this mini review, the separation performance of different types of zeolite membranes with respect to interested gas pairs will be compared. We aim to give readers an idea of membrane separation status. A few representative synthesis conditions are arbitrarily chosen and summarized, along with the corresponding separation performance. This review can be used as a quick reference with respect to the influence of synthesis conditions on membrane quality. At the end, some general findings and perspectives will be discussed.

Recent progress on CO2 separation membranes

“…In addition, it is important to conduct more membrane tests under close-to-realistic operating conditions, such as complex/ real feed mixture and high operating pressure, to reveal the real-world performance for better assessment of the membrane potential. 33 Zeolite membranes are benecial for the adsorption and separation of CO 2 due to their small pore structure and strong electrostatic eld. Nonetheless, adequate control of their microstructure and research into the mechanism for their generation remain signicant barriers to their wider deployment.…”

“…In addition, it is important to conduct more membrane tests under close-to-realistic operating conditions, such as complex/real feed mixture and high operating pressure, to reveal the real-world performance for better assessment of the membrane potential. 33 …”

Influence of temperatures and loadings on olefin diffusion in MFI-type zeolites in one- to three-dimensions

“…In theory, by adjusting the siliconto-aluminium ratio and introducing other elements, an infinite number of zeolite types can be synthesised to meet various application requirements. [21][22][23] The diversity and tunability of zeolites make them vital materials in chemical engineering, 24,25 petroleum industry, 26,27 and environmental engineering, 28,29 providing extensive versatility in processes such as adsorption, [30][31][32] separation, 33,34 and catalysis. 35,36 In particular, H-MFI zeolite is highly favoured in crucial industrial processes such as cracking due to the presence of a combination of microporous and mesoporous structures and Brønsted acid sites.…”

Nanosized Zeolite P for Enhanced CO2 Adsorption Kinetics

“…This is attributed to their crystalline structure, welldefined micropores, adjustable chemical composition, and physicochemical stability. 3 They are considered among the most promising solid-state adsorbents for selectively capturing CO 2 over other small gases such as N 2 and CH 4 . 4 In the vast majority of cases, the existing literature solely focuses on factors such as high capacity, high selectivity, and long-term chemical and physical stability when discussing the performance of adsorbents.…”