Asymmetric integrally-skinned flat sheet membranes for H2 purification and natural gas upgrading

Patent metadata

Field	Value
Publication number	US-9751053-B2
Application number	US-201414497743-A
Country	US
Kind code	B2
Filing date	Sep 26, 2014
Priority date	Sep 26, 2014
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

An asymmetric integrally-skinned flat sheet membrane comprising a miscible blend of an aromatic polyethersulfone (PES) polymer and an aromatic polyimide polymer is used for gas separations such as hydrogen purification, separation of hydrogen and methane and to separate other gases and liquids. UV radiation may be applied to the surface of the membrane for improved properties.

First claim

The invention claimed is:

1. An asymmetric integrally-skinned flat sheet gas separation membrane comprising a highly porous, non-selective symmetric woven Nylon fabric backing, a miscible blend of an aromatic polyethersulfone (PES) polymer and an aromatic polyimide polymer that comprises a plurality of repeating units of formula (I)

wherein X1 is selected from the group consisting of

wherein X2 is selected from the group consisting of

wherein n and m are independent integers from 20 to 500 wherein said asymmetric integrally-skinned flat sheet membrane has a layer of said miscible blend of said PES polymer and said aromatic polyimide polymer with a thickness from 60 microns to 230 microns, and wherein said membrane has a hydrogen over methane selectivity of at least 100.

2. The asymmetric integrally-skinned flat sheet membrane of claim 1 wherein the surface of said layer of miscible blend is UV cross-linked.

3. The asymmetric integrally-skinned flat sheet membrane of claim 1 wherein the weight ratio of said PES polymer to said aromatic polyimide polymer is in a range of 1:5 to 5:1.

4. The asymmetric integrally-skinned flat sheet membrane of claim 1 comprises PES and aromatic polyimide polymer chain segments where at least part of these polymer chain segments are cross-linked to each other through direct covalent bonds by exposure to UV radiation.

5. The asymmetric integrally-skinned flat sheet membrane of claim 1 wherein said aromatic polyimide polymer is selected from the group consisting of poly(3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride-3,3′,5,5′-tetramethyl-4,4′-methylene dianiline); poly(3,3′,4,4′-benzophenone tetracarboxylic dianhydride-pyromellitic dianhydride-3,3′,5,5′-tetramethyl-4,4′-methylene dianiline) and poly(3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride-pyromellitic dianhydride-3,3′,5,5′-tetramethyl-4,4′-methylene dianiline).

6. The asymmetric integrally-skinned flat sheet membrane of claim 1 comprising a blend of said PES polymer and poly(3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride- 3,3′,5,5′-tetramethyl-4,4′-methylene dianiline).

7. The asymmetric integrally-skinned flat sheet membrane of claim 1 comprising a blend of said PES polymer and poly(3,3′,4,4′-benzophenone tetracarboxylic dianhydride-pyromellitic dianhydride- 3,3′,5,5′-tetramethyl-4,4′-methylene dianiline).

Assignees

• Uop Llc

Inventors

• Liu Chunqing
• Tran Howie Q

Classifications

• B01D2323/345

  UV-treatment · CPC title

• B01D2325/022

  Asymmetric membranes · CPC title

• B01D53/228

  characterised by specific membranes · CPC title

• B01D71/68 Primary

  Polysulfones; Polyethersulfones · CPC title

• B01D69/06

  Flat membranes · CPC title