Recent Advances in Carbon Dioxide Separation Membranes: A Review
Eiji Kamio, Tomohisa Yoshioka, Hideto Matsuyama
Abstract
Separation membranes, which have the possibility to develop energy-saving and compact processes, are expected to be applied in the field of CO₂ separation and capture and are attracting considerable interest from both industries and academia. The purpose of this review is to provide an overview of recent advances in both organic and inorganic materials for high-performance CO₂ separation membranes from the viewpoint of molecular design to an engineering perspective. The overview includes gas permeation theory for CO₂ capture and separation, controlled intrinsic micropores and their size-sieving property, CO₂ diffusivity in the membrane matrix, selective CO₂ solubility and selective permeability, functionalization using chemical reactions, etc. CO₂ separation mechanisms and the effects of properties of membrane materials on both the CO₂ permeability and permselectivity over other light gases are discussed, and the recent developments regarding inorganic and glassy polymer membranes with intrinsic microporous structures, rubbery polymer membranes, ionic liquid-based gel membranes, and facilitated-transport membranes are reviewed. Taking into consideration the industrial applications, the characteristics of each membrane with respect to process design, such as membrane thickness, and physical aging, and dependence of CO₂ permeability on gas properties, are also discussed. Finally, future research challenges and perspectives for the commercialization of CO₂ capture and separation process using high-performance materials are proposed.