Preparation and properties of organic-inorganic hybrid facilitated olefin separation membranes via sol-gel method

摘要

Separation of olefins through membranes has attracted much attention due to the energy intensiveness of the conventional distillation process. It has been known that the silver ion (Ag~+) based facilitated transport mechanism in the liquid membranes or ion-exchanged membranes for olefin separation is controlled by the diffusion of the olefin-Ag~+ complex through the membranes. Mainly, three types of facilitated Ag+ membranes have been reported: supported liquid membranes, ion- exchange membranes, and salt/polymer blend membranes. Both the supported liquid membranes and ion-exchange membranes require that the feed gas be saturated with solvent, to maintain the selectivities of the membranes, and silver-polymer blend membranes can be used to separate olefins and paraffins without water; however, their applications are limited by the low thermal stability and low permeability. The disadvantage of these approaches is that the facilitated transport in the membranes will be greatly decreased with the loss of water from the membranes. Therefore, further research is needed to find novel olefin separation membranes without addition of water into the feed.