Abstract: Disclosed is a process for the polymerization of olefins wherein olefinic compounds are separated from mixtures containing them with resulting improved utilization of olefinic compounds. Such olefinic compounds are separated by use of membrane separation units and can be recycled to a polymerization zone.

Abstract: A process is disclosed for separating components, e.g., olefinically-unsaturated hydrocarbons, from mixtures with other materials by liquid barrier permeation and metal-complexing techniques using a semi-permeable membrane and a partial pressure differential across the membrane for the material being separated. The process is characterized by the use of elevated pressure on the feed side of the membrane, preferably at least about 200 psig, a low total pressure differential, if any, across the membrane, and preferably a partial pressure of the material being separated on the exit side of the membrane which is at least about 20 psi less than on the feed side. The separated material may be removed with advantage by the use of a liquid solvent in which the material is soluble, and preferably the concentration of the material in the solvent is up to about 25 weight percent of saturation when the solvent is charged to the exit side of the membrane.