ULTRA-SELECTIVE CARBON MOLECULAR SIEVE MEMBRANES AND METHODS OF MAKING

• US 20160346740A1
• Filed: 06/01/2016
• Published: 12/01/2016
• Est. Priority Date: 06/01/2015
• Status: Abandoned Application

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Zhang, Chen, Koros, William John
• Application Number:
  US15/170,529
• Publication Number:
  US 20160346740A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B01D 2053/224 with hollow fibres
• CPC Class Codes: B01D 2253/102 Carbon
• CPC Class Codes: B01D 2256/10 Nitrogen
• CPC Class Codes: B01D 2256/12 Oxygen
• CPC Class Codes: B01D 2256/16 Hydrogen
• CPC Class Codes: B01D 2256/245 Methane
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2323/08 Specific temperatures applied
• CPC Class Codes: B01D 2323/081 Heating
• CPC Class Codes: B01D 2325/022 Asymmetric membranes
• CPC Class Codes: B01D 2325/20 Specific permeability or cut-off range
• CPC Class Codes: B01D 53/22 by diffusion manufacturing semi-permeable membranes B01D67/00; form, structure or properties of semi-permeable membranes B01D69/00; material for semi-permeable membranes B01D71/00
• CPC Class Codes: B01D 53/228 characterised by specific membranes
• CPC Class Codes: B01D 67/0067 by carbonisation or pyrolysis
• CPC Class Codes: B01D 69/02 characterised by their properties
• CPC Class Codes: B01D 71/021 Carbon
• CPC Class Codes: B01D 71/028 Molecular sieves carbon B01D71/021
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

Embodiments of the present disclosure are directed to a process for making a carbon molecular sieve membrane having a desired permselectivity between a first gas species and a second gas species, in which the second gas species has a larger kinetic diameter than the first gas species. The process comprises providing a polymer precursor and pyrolyzing the polymer precursor at a pyrolysis temperature that is effective to selectively reduce the sorption coefficient of the second gas species, thereby increasing the permselectivity of the resulting carbon molecular sieve membrane.

Claims

1. A process for making a carbon molecular sieve membrane having a desired permselectivity between a first gas species and a second gas species, the second gas species having a larger kinetic diameter than the first gas species, comprising

a. providing a polymer precursor;

and

b. pyrolyzing the polymer precursor at a pyrolysis temperature that is effective to selectively reduce the sorption coefficient of the second gas species, thereby increasing the permselectivity of the resulting carbon molecular sieve membrane.

2. The process of claim 1, wherein the second gas species is CH₄.

3. The process of any one of claim 2, wherein the first gas species is H₂.

4. The process of any one of claim 2, wherein the first gas species is N₂.

5. The process of any one of claim 2, wherein the first gas species is CO₂.

6. The process of claim 1, wherein the first gas species is CO₂ and the second gas species is N₂.

7. The process of claim 1, wherein the pyrolysis temperature is at least 800°

C.

8. The process of claim 7, wherein the pyrolysis temperature is at least 850°

C.

9. The process of claim 8, wherein the pyrolysis temperature is greater than 875°

C.

10. The process of claim 9, wherein the pyrolysis temperature is greater than 900°

C.

11. The process of claim 1, wherein the polymer precursor comprises a polymeric fiber or polymeric film.

12. The process of claim 11, wherein the polymer precursor comprises an asymmetric hollow polymer fiber.

13. The process of claim 1, wherein the polymer precursor comprises a polyimide.

29. A process for separating at least a first gas species and a second gas species, comprising:

(a) providing a carbon molecular sieve membrane produced by the process of claim 1, and

(b) flowing a mixture of at least the first gas species and the second gas species through the membrane to produce;

(i) a retentate stream having a reduced concentration of the first gas species, and

(ii) a permeate stream having an increased concentration of the first gas species.

30. The process of claim 29, wherein the first gas species is CO₂ and the second gas species is N₂.

31. A process for separating non-hydrocarbon components from a natural gas stream comprising

(a) providing a carbon molecular sieve membrane produced by the process of claim 1, and

(b) contacting a natural gas stream with said membrane to produce

(i) a retentate stream having a reduced concentration of non-hydrocarbon components, and

(ii) a permeate stream having an increased concentration of non-hydrocarbon components.

32. The process of claim 31, wherein the non-hydrocarbon components comprise H₂, N₂, CO₂, H₂S, or mixtures thereof.

33. The carbon molecular sieve membrane produced by the process of claim 1.

34. A carbon molecular sieve module comprising a sealable enclosure, said enclosure having:

a plurality of carbon molecular sieve membranes contained therein, at least one of said carbon molecular sieve membranes produced according to the process of claim 1,

an inlet for introducing a feed stream comprising at least a first gas species and a second gas species;

a first outlet for permitting egress of a permeate gas stream; and

,

a second outlet for permitting egress of a retentate gas stream.

14-28. -28. (canceled)

35. A mixed-matrix carbon molecular sieve membrane having a permselectivity between a first gas species and a second gas species, the second gas species having a larger kinetic diameter than the first gas species, comprising:

a. a matrix material; and

b. a sieve material;

wherein the sieve material comprises a carbon molecular sieve material having micropores that are sized so as to exclude sorption of the second gas species; and

the matrix material comprises a carbon molecular sieve material having micropores that are sized so as to provide for sorption of the second gas species.

36. The mixed-matrix carbon molecular sieve membrane of claim 35, wherein the second gas species is CH₄.

37. The mixed-matrix carbon molecular sieve membrane of claim 35, wherein the second gas species is N₂.

38. The mixed-matrix carbon molecular sieve membrane of claim 35, wherein the mixed-matrix carbon molecular sieve membrane has substantially no sieve-matrix interface.