Xylene isomer separations by intrinsically porous molecular materials

Abstract

Summary: Xylene mixtures and the three individual isomers are valuable chemical feedstocks in the chemical industry. Separation of these isomers is a pressing challenge due to their overlapping physicochemical properties. Traditional separation technologies like distillation are energy intensive and laborious and are not appropriate for sustainable development. To reduce the high energy consumption and decrease the environmental impact, adsorption by porous materials has been proposed and proven as an alternative strategy. Intrinsically porous molecular materials (IPMs) are mainly composed of organic macrocycles and cages that possess guest-accessible intrinsic cavities. They have been used for energy-intensive separations because of their high efficiency and low energy consumption. In this review, we provide a comprehensive summary of IPM-based xylene separations, as well as an overview of the challenges associated with the development of the technology and the future industrial translation of this class of materials.