Processes for recovering oligomers of glycols and polymerization catalyst from waste streams
OwnerHari Sunkara, James Cavall +1inventors
InventorsHari Sunkara, James Cavall, William Goudie
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Abstract
Processes for recovering and recycling oligomers and polymerization catalyst from aqueous waste streams generated during the production of polyalkylene ether glycols are provided. The processes utilize membranes; preferably reverse osmosis or nanofilter membranes. The processes can reduce waste and costs associated with the polymerization of polyalkylene ether glycols by recovery and recycling of glycols and catalysts
Claims24
A process for recovering and recycling polyalkylene ether glycol oligomers from aqueous wash streams generated during production of polyalkylene ether glycols comprising:
- (a) providing an aqueous wash stream comprising oligomeric polyalkylene ether glycol obtained from a process comprising a catalyzed polycondensation reaction of monomeric diol and subsequent hydrolysis of the resulting polymer;
- (b) providing a membrane device comprising a membrane having a retentate side and a permeate side;
- (c) contacting a feed stream comprising the aqueous wash stream with the retentate side of the membrane such that a portion of the feed stream is rejected to provide a retentate containing concentrated polyalkylene ether glycol oligomers, the retentate being substantially retained in contact with the retentate side of the membrane;
- (d) recovering the retentate containing concentrated polyalkylene ether glycol oligomers;
- and
- (e) recycling the retentate containing concentrated polyalkylene ether glycol to the polycondensation reaction.
Dependencies are inferred from the claim text.