Recent progress of ZIF-8 membrane for propylene/propane separation

Separation of olefins/paraffins with the same carbon number is currently one of the most energy-consuming processes in the petrochemical industry. The development of new, low-energy propylene/propane separation processes is considered to be one of the seven chemical separation technologies that can change the world. Gas separation membrane technology is considered to be an alternative technology for replacing conventional cryogenic distillation to separate propylene/propane mixture due to its high efficiency, energy-saving and environmental-friendliness. The effective pore diameter of the metal-organic framework material ZIF-8 is just between the molecular dynamic diameters of propylene and propane, which can achieve efficient separation of propylene/propane. Among various membrane materials, ZIF-8 exhibits the best separation performance for propylene/propane mixture. This review systematically summarized the both preparation method and development process of ZIF-8 membrane for propylene/propane separation. The regulation of ZIF-8 membrane microstructure, especially the repair of membrane defects and the control of ZIF-8 framework flexibility, was discussed. The influence of the process parameters on the propylene/propane separation performance of ZIF-8 membrane was also discussed. The problems and future development of ZIF-8 membrane in large-scale preparation and potential industrial separation of propylene/propane were proposed. © 2020, Chemical Industry Press. All right reserved.