MEMBRANE SEPARATION OF OLEFIN AND PARAFFIN MIXTURES

• US 20150025293A1
• Filed: 07/17/2014
• Published: 01/22/2015
• Est. Priority Date: 07/18/2013
• Status: Active Grant

• Current Assignee: Compact Membrane Systems Inc.
• Original Assignee: Cms Technologies Holdings, Inc.
• Inventors: Feiring, Andrew Edward, Majumdar, Sudipto, Lazzeri, Jonathan
• Granted Patent: US 10,029,248 B2
• Time in Patent Office: Days
• US Class Current: 585/818
• CPC Class Codes: B01D 53/228 characterised by specific membranes
• CPC Class Codes: B01D 71/32 containing fluorine atoms
• CPC Class Codes: B01D 71/52 Polyethers
• CPC Class Codes: B01D 71/76 Macromolecular material not specifically provided for in a single one of groups B01D71/08 - B01D71/74 rubbers in general B01D71/24
• CPC Class Codes: B01D 71/82 characterised by the presence of specified groups, e.g. introduced by chemical after-treatment
• CPC Class Codes: B01J 39/20 obtained by reactions only involving unsaturated carbon-to-carbon bonds
• CPC Class Codes: B01J 41/14 obtained by reactions only involving unsaturated carbon-to-carbon bonds
• CPC Class Codes: B01J 47/12 characterised by the use of ion-exchange material in the form of ribbons, filaments, fibres or sheets, e.g. membranes electrodialysis or electro-osmosis B01D61/42
• CPC Class Codes: C07C 11/04 Ethylene
• CPC Class Codes: C07C 11/06 Propene
• CPC Class Codes: C07C 11/08 with four carbon atoms
• CPC Class Codes: C07C 7/144 using membranes, e.g. selective permeation
• CPC Class Codes: Y02P 20/50 Improvements relating to the production of bulk chemicals

Abstract

A metal exchanged fluorinated ionomer is a copolymer minimally including repeating units of (i) a polymerized derivative of a perfluorinated cyclic or cyclizable monomer and (ii) a strong acid highly fluorinated vinylether compound in which the acid moiety is exchanged with a cation of a Group 11 metal. Metal exchanged fluorinated ionomers are readily soluble and can be formed into thin, selectively gas permeable membranes by solution deposition methods. These membranes are suitable for separating olefins from gas olefin/paraffin mixtures. Good selectivity and transmembrane flux can be obtained without humidifying the membrane feed gas mixture.

Claims

1. A gas separation membrane comprising a nonporous selectively permeable layer consisting essentially of a metal exchanged fluorinated ionomer comprising repeating units A and B in which

A is a polymerized derivative of a perfluorinated cyclic or cyclizable organic compound, and

B has the formula

2. The membrane of claim 1 in which the perfluorinated cyclic or cyclizable compound is selected from the group consisting of perfluoro-2,2-dimethyl-1,3-dioxole (PDD), perfluoro-2-methylene-4-methyl-1,3-dioxolane (PMD), perfluoro (alkenyl vinylether) (“

PFVE”

), and 2,2,4-trifluoro-5-trifluoromethoxy-1,3-dioxole (TFMD).

3. The membrane of claim 1 in which the repeating units B are a polymerized derivative of a highly fluorinated vinylether compound selected from the group consisting of vinylethers containing sulfonyl fluoride, vinylethers containing sulfonamide, vinylether carboxylates, and a blend thereof.

4. The membrane of claim 3 in which the highly fluorinated vinylether compound is selected from the group consisting of CF₂═

CFOCF₂CF(CF₃)OCF₂CF₂SO₂F (“

SEFVE”

), CF₂═

CFOCF₂CF₂SO₂F, CF₂═

CFOCF₂CF₂CF₂CF₂SO₂F, CF₂═

CFOCF₂CF(CF₃)OCF₂CF₂CO₂CH₃, and a blend thereof.

5. The membrane in claim 1 in which the metal exchanged fluorinated ionomer further comprises repeating units that are polymerized derivatives of fluorinated monomers selected from the group consisting of chlorotrifluoroethylene (CTFE), trifluoroethylene (TrFE), and vinylidene fluoride (VF₂).

6. A method of making a metal exchanged fluorinated ionomer comprising the steps of:

(A) providing a hydrolyzed copolymer comprising repeating units A and B, A being a polymerized derivative of a perfluorinated cyclic or cyclizable organic compound and B having the formula

7. The method of claim 6 in which the liquid solvent system consists essentially of organic polar solvent and is free of fluorinated solvent.

8. The method of claim 6 in which the step of providing a hydrolyzed copolymer comprises

(A1) copolymerizing a perfluorinated cyclic or cyclizable organic compound and a highly fluorinated vinylether compound that provides a repeating unit having the formula

9. The method of claim 6 in which the step of providing a hydrolyzed copolymer comprises

(A1) copolymerizing a perfluorinated cyclic or cyclizable organic compound and a highly fluorinated vinylether compound that provides a repeating unit having the formula

10. A method of making a membrane for the separation of olefins from a mixture with paraffins, comprising the steps of:

(I) providing a metal exchanged fluorinated ionomer solution produced by a method comprising the following steps

(A) providing a metal exchanged fluorinated ionomer comprising repeating units A and B in which A is a polymerized derivative of a perfluorinated Cyclic or cyclizable organic compound, B has the formula

11. The method of claim 10 in which the liquid solvent system consists essentially of organic polar solvent and is free of fluorinated solvent.

12. The method of claim 10 in which providing the metal exchanged fluorinated ionomer solution comprises the following steps,

(A) providing a hydrolyzed copolymer comprising repeating units A and B, A being a polymerized derivative of a perfluorinated cyclic or cyclizable organic compound and repeating units B having the formula

13. The method of claim 12 in which the liquid solvent system consists essentially of organic polar solvent and is free of fluorinated solvent.

14. The method of claim 12 in which the step of providing a hydrolyzed copolymer comprises

(A1) copolymerizing a perfluorinated cyclic or cyclizable organic compound and a highly fluorinated vinylether compound that provides a repeating unit having the formula

15. The method of claim 12 in which the step of providing a hydrolyzed copolymer comprises

(A1) copolymerizing a perfluorinated cyclic or cyclizable organic compound and a highly fluorinated vinylether compound that provides a repeating unit having the formula

16. A method of separating an olefin from a feed mixture of the olefin with a paraffin comprising the following steps:

(A) providing a selectively permeable membrane comprising a nonporous layer consisting essentially of a metal exchanged fluorinated ionomer comprising repeating units A and B in which A is a polymerized derivative of a perfluorinated cyclic or cyclizable organic compound, and B has the formula

17. The method of claim 16 in which the feed mixture and permeate product are fluids, and in which the step of applying a driving force comprises contacting the permeate side of the membrane with a sweep fluid.

18. The method of claim 17 in which the sweep gas comprises an olefin and the permeate product is at a lower pressure than the feed gas mixture.

19. The method of claim 17 in which the sweep fluid comprises water vapor.

20. The method of claim 19 in which the feed mixture and the sweep fluid comprise water vapor.

21. The method of claim 19 in which the feed mixture is free of water vapor.

22. The method of claim 17 in which the sweep fluid is free of any non-condensable vapor component.

23. The method of claim 16 in which the feed mixture comprises a pair of compounds selected from the group consisting of (i) ethylene and ethane, (ii) propylene and propane, and (iii) butylene and butane.

24. A metal exchanged ionomer solution comprising

(I) a liquid solvent system comprising a polar solvent, and

(II) a metal exchanged fluorinated ionomer comprising repeating units A and B in which A is a polymerized derivative of a perfluorinated cyclic or cyclizable organic compound, and B has the formula

25. The metal exchanged ionomer solution of claim 24 in which the liquid solvent system comprises about 10-100 vol.% organic polar solvent and a complementary amount of fluorinated solvent to total 100 vol.%

26. The metal exchanged ionomer solution of claim 25 in which the liquid solvent system consists essentially of organic polar solvent and is free of fluorinated solvent.

27. The metal exchanged ionomer solution of claim 24 in which the perfluorinated cyclic or cyclizable compound is selected from the group consisting of perfluoro-2,2-dimethyl-1,3-dioxole (PDD), perfluoro-2-methylene-4-methyl-1,3-dioxolane (PMD), perfluoro (alkenyl vinylether) (“

PFVE”

), and 2,2,4-trifluoro-5-trifluoromethoxy-1,3-dioxole (TFMD).