Ultra-selective carbon molecular sieve membranes and methods of making

Patent metadata

Field	Value
Publication number	US-2016346740-A1
Application number	US-201615170529-A
Country	US
Kind code	A1
Filing date	Jun 1, 2016
Priority date	Jun 1, 2015
Publication date	Dec 1, 2016
Grant date	—

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.

First claim

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 CH 4 .

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

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

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

6 . The process of claim 1 , wherein the first gas species is CO 2 and the second gas species is N 2 .

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.

14 .- 28 . (canceled)

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 CO 2 and the second gas species is N 2 .

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 H 2 , N 2 , CO 2 , H 2 S, 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.

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 CH 4 .

37 . The mixed-matrix carbon molecular sieve membrane of claim 35 , wherein the second gas species is N 2 .

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.

Assignees

• Georgia Tech Res Inst

Inventors

• Koros William John
• Zhang Chen

Classifications

• B01D67/0083

  Thermal after-treatment · CPC title

• B01D2053/221

  Devices · CPC title

• B01D71/021 Primary

  Carbon · CPC title

• B01D2317/00

  Membrane module arrangements within a plant or an apparatus · CPC title

• B01D53/225

  Multiple stage diffusion · CPC title