High hydrocarbon resistant chemically cross-linked aromatic polyimide membrane for separations

Patent metadata

Field	Value
Publication number	US-9126154-B2
Application number	US-201313929864-A
Country	US
Kind code	B2
Filing date	Jun 28, 2013
Priority date	Jun 28, 2013
Publication date	Sep 8, 2015
Grant date	Sep 8, 2015

Abstract

This invention relates to high hydrocarbon resistant chemically cross-linked aromatic polyimide polymers, membranes and methods for making and using these polymers and membranes. The high hydrocarbon resistant chemically cross-linked aromatic polyimide membrane described in the present invention comprises a plurality of repeating units of a first aromatic polyimide comprising hydroxyl groups cross-linked with a second aromatic polyimide comprising carboxylic acid groups via covalent ester bonds. These membranes exhibit high permeability and selectivity in separation of mixtures of gases and liquids.

First claim

The invention claimed is:

1. A process for separating at least one gas from a mixture of gases comprising
a. providing a chemically cross-linked aromatic polyimide membrane comprising a formula (I)

wherein R is —COCH 3 or,

and mixtures thereof; X1, X2, X3, and X4 are selected from the group consisting of

and mixtures thereof, respectively; Y2 is selected from the group consisting of

and mixtures thereof, and —R′— is selected from the group consisting of

and mixtures thereof; Y1 and Y3 are selected from the group consisting of

and mixtures thereof;
n, m, n′ and m′ are independent integers from 2 to 500; n/m is in a range of 1:100 to 100:1; and n′/m′ is also in a range of 1:100 to 100:1;

b. contacting the mixture of gases to one side of the chemically cross-linked aromatic polyimide membrane to cause at least one gas to permeate said membrane; and
c. removing from an opposite side of said chemically cross-linked aromatic polyimide membrane a permeate gas composition comprising a portion of said at least one gas that permeated said membrane.

2. The process of claim 1 wherein said at least two gases are a mixture of volatile organic compounds and atmospheric gas.

3. The process of claim 1 wherein said at least two gases are a mixture of helium, nitrogen, carbon dioxide or hydrogen sulfide, or mixtures thereof in a natural gas stream.

4. The process of claim 1 wherein said mixture of gases are a pair of gases selected from the group consisting of nitrogen and oxygen, carbon dioxide and methane, hydrogen and methane, nitrogen and methane, or a mixture of carbon monoxide, helium and methane.

5. The process of claim 1 wherein said mixture of gases are selected from the group consisting of a mixture of iso and normal paraffins, and a mixture of xylenes.

6. The process of claim 1 wherein said mixture of gases are a hydrocarbon vapor and hydrogen.

7. The process of claim 1 wherein said mixture of gases is a mixture of propylene and propane.

8. The process of claim 1 wherein the mixture of gases comprises methane, carbon dioxide, oxygen, nitrogen, water vapor, hydrogen sulfide, and helium.

Assignees

• Uop Llc

Inventors

• Liu Chunqing
• Osman Zara

Classifications

• B01D61/025

  Reverse osmosis; Hyperfiltration · CPC title

• B01D61/145

  Ultrafiltration · CPC title

• B01D2323/08

  Specific temperatures applied · CPC title

• C08J2379/08

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

• C08J3/247 Primary

  Heating methods · CPC title