Polyimide membrane for h2s removal

Patent metadata

Field	Value
Publication number	US-2016184771-A1
Application number	US-201514974355-A
Country	US
Kind code	A1
Filing date	Dec 18, 2015
Priority date	Dec 31, 2014
Publication date	Jun 30, 2016
Grant date	—

Abstract

H 2 S is removed from a feed gas by a gas separation membrane including a separation layer that is made of a blend of P84 and Matrimid.

First claim

What is claimed is:

1 . A method of removing H 2 S from a feed gas, comprising the steps of:
feeding the feed gas comprising at least 2 vol % H 2 S to a feed gas inlet of a gas separation membrane apparatus that includes a composite fluid separation membrane, a permeate gas outlet, and a non-permeate gas outlet, the membrane comprising a separation layer supported by a porous support layer, the porous support layer comprising a polymeric material, the separation layer comprising a first polymide optionally blended with a second polymide, the first polymide being represented by formula (I):

the second polyimide being represented by formula (II):

where R 1 is a molecular segment selected from the group consisting of the molecular segments of formula (A), formula (B), formula (C), and combinations thereof:

withdrawing a permeate gas comprising H 2 S from a permeate outlet of the membrane; and
withdrawing a non-permeate gas from a non-permeate outlet of the membrane, wherein the non-permeate gas has a H 2 S concentration lower than that of the feed gas.

2 . The method of claim 1 , wherein 16% of the R 1 's are the molecular segment of formula (A), 64% of the R 1 's are the molecular segment of formula (B), and 20% of the R 1 's are the molecular segment of formula (C).

3 . The method of claim 1 , wherein the feed gas comprises 2 vol % to 20 vol % of H 2 S.

4 . The method of claim 1 , wherein the feed gas comprises 5-20 vol % of H 2 S.

5 . The method of claim 1 , wherein the feed gas is natural gas.

6 . The method of claim 1 , wherein the feed gas is natural gas comprising at least 500 ppm H 2 S and a balance of CO 2 and CH 4 .

7 . The method of claim 1 , wherein the feed gas is natural gas comprising at least 500 ppm H 2 S and a balance of CO 2 , CH 4 and N 2 .

8 . The method of claim 1 , wherein:
16% of the R 1 's are the molecular segment of formula (A), 64% of the R 1 's are the molecular segment of formula (B), and 20% of the R 1 's are the molecular segment of formula (C); and the feed gas comprises 500 ppm to 20 vol % of H 2 S.

9 . The method of claim 8 , wherein the feed gas is natural gas.

10 . The method of claim 8 , wherein the feed gas is natural gas comprising at least 500 ppm H 2 S and a balance of CO 2 and CH 4 .

11 . The method of claim 8 , wherein the feed gas is natural gas comprising at least 500 ppm H 2 S and a balance of CO 2 , CH 4 and N 2 .

12 . The method of claim 1 , wherein:
16% of the R 1 's are the molecular segment of formula (A), 64% of the R 1 's are the molecular segment of formula (B), and 20% of the R 1 's are the molecular segment of formula (C); and the feed gas is natural gas.

13 . The method of claim 1 , wherein:
16% of the R 1 's are the molecular segment of formula (A), 64% of the R 1 's are the molecular segment of formula (B), and 20% of the R 1 's are the molecular segment of formula (C); and the feed gas is natural gas comprising at least 500 ppm H 2 S and a balance of CO 2 and CH 4 .

14 . The method of claim 1 , wherein:
16% of the R 1 's are the molecular segment of formula (A), 64% of the R 1 's are the molecular segment of formula (B), and 20% of the R 1 's are the molecular segment of formula (C); and the feed gas is natural gas comprising at least 500 ppm H 2 S and a balance of CO 2 , CH 4 and N 2 .

15 . The method of claim 1 , wherein the feed gas is natural gas comprising 500 ppm of H 2 S.

16 . The method of claim 15 , wherein the feed gas is natural gas comprising at least 500 ppm H 2 S and a balance of CO 2 and CH 4 .

17 . The method of claim 15 , wherein the feed gas is natural gas comprising at least 500 ppm H 2 S and a balance of CO 2 , CH 4 and N 2 .

18 . The method of claim 1 , wherein the separation layer comprises the first polyimide but not the second polyimide.

19 . The method of claim 1 , wherein the separation layer comprises a blend of the first and second polyimides.

Assignees

• Air Liquide

Inventors

• Kulkarni Sudhir S
• Kratzer Dean W
• Sanders Jr Edgar S
• Fleming Gregory K
• Worley Fan Z

Classifications

• C10L2290/548

  Membrane- or permeation-treatment for separating fractions, components or impurities during preparation or upgrading of a fuel · CPC title

• C10L3/103

  Sulfur containing contaminants · CPC title

• B01D53/228 Primary

  characterised by specific membranes · CPC title

• B01D71/64

  Polyimides; Polyamide-imides; Polyester-imides; Polyamide acids or similar polyimide precursors · CPC title

• B01D69/12

  Composite membranes; Ultra-thin membranes · CPC title