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

Compared with current conventional technologies, oxygen/nitrogen (O-2/N-2) 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 O-2 permeability and high O-2/N-2 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 O-2 and for production of high-purity N-2. Meanwhile, perovskite membrane can be used to produce a high-purity oxygen. Furthermore, the developments of O-2/N-2 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.