Recent progress and challenges in membrane-based O₂/N₂ separation

Compared with current conventional technologies, oxygen/nitrogen (O₂/N₂) separation using membrane offers numerous advantages, especially in terms of energy consumption, footprint, and capital cost. However, low product purity still becomes the major challenge for commercialization of membrane-based technologies. Therefore, numerous studies on membrane development have been conducted to improve both membrane properties and separation performance. Various materials have been developed to obtain membranes with high O₂ permeability and high O₂/N₂ selectivity, including polymer, inorganic, and polymer-inorganic composite materials. The results showed that most of the polymer membranes are suitable for production of low to moderate purity O₂ and for production of high-purity N₂. Meanwhile, perovskite membrane can be used to produce a high-purity oxygen. Furthermore, the developments of O₂/N₂ separation using membrane broaden the applications of oxygen enrichment for oxy-combustion, gasification, desulfurization, and intensification of air oxidation reactions, while nitrogen enrichment is also important for manufacturing pressure-sensitive adhesive and storing and handling free-radical polymerization monomers.