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US 4,623,704 AGranted
Use of membranes for ethylene recovery in polymerization processes
AssigneeThe Dow Chemical Company
InventorsDennis R. Dembicki, Frederick L. Coan, Craig L. Glassford, Dana C. Overman
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Abstract
An improved process for recovery of ethylene from a polymerization process is described. A normally solid membrane is employed to recover an ethylene enriched gas stream from the polymerization vent gases. The ethylene enriched gas stream is recycled to the polymerization process.
Claims16
An improved process for manufacture of ethylene polymers wherein the improvement comprises:
- (a) contacting at least part of the gas mixture remaining after polymerization containing unconverted ethylene monomer with a normally solid, semi-permeable, asymmetric, water-dry, cellulose triacetate hollow fiber membrane at conditions which promote selective permeation of ethylene through the membrane;
- and
- (b) recycling the ethylene-enriched permeate as feed for the ethylene polymerization.
Dependencies are inferred from the claim text.