Olefin/paraffin separation through membrane: from mechanisms to critical materials
Separation of olefin and paraffin is one of the most challenging and energy-intensive process, which has attracted more and more intention over the past decades. The well-established separation technology in industry, the so called cryogenic high-pressure distillation, requires large distillation columns with 120 to 180 trays because of the similar size and boiling point of olefin and paraffin, consuming huge amount of energy. In addition to the traditional cryogenic distillation, non-thermal separation processes like preferential adsorption and membrane separation has been developed to circumvent the utilization of heat and diminish the energy consumption. Membrane separation show great advantages for olefin/paraffin separation due to their low energy consumption and continuous operation. The rapid development of novel porous materials, e. g., metal organic frameworks (MOFs), covalent organic frameworks (COFs), polymers of intrinsic microporosity (PIMs), further boost the researches on the membrane separation of olefin and paraffin in recent years. In this review, we first summarize the separation mechanisms adopted up to now for olefin/paraffin separation. Then, we summarize the materials used for the membrane fabrication and separation, including traditional dense polymers, inorganic zeolites, carbon molecular sieves (CMSs) and newly developed MOFs. Special attention is paid on the new separation mechanisms, novel porous materials and strategies for membrane fabrication.
- This article is part of the themed collection: Journal of Materials Chemistry A Emerging Investigators