Gas Separation Membranes Based on Fluorinated and Perfluorinated Polymers

• US 20160045859A1
• Filed: 10/23/2015
• Published: 02/18/2016
• Est. Priority Date: 02/19/2014
• Status: Active Grant

• Current Assignee: Membrane Technology and Research, Inc., New York University
• Original Assignee: Membrane Technology and Research, Inc.
• Inventors: He, Zhenjie, Merkel, Timothy C., Okamoto, Yoshiyuki, Koike, Yasuhiro, Zhang, Hao
• Granted Patent: US 9,643,124 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B01D 2256/245 Methane
• CPC Class Codes: B01D 2257/102 Nitrogen
• CPC Class Codes: B01D 2257/108 Hydrogen
• CPC Class Codes: B01D 2257/11 Noble gases
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/228 characterised by specific membranes
• CPC Class Codes: B01D 71/32 containing fluorine atoms
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

A process for separating components of a gas mixture using gas-separation copolymer membranes. These membranes use a selective layer made from copolymers of partially fluorinated or perfluorinated dioxolane monomers and a second monomer, such as dioxane or a partially fluorinated dioxolane. The resulting membranes have superior selectivity performance for gas pairs of interest while maintaining fast gas permeance compared to membranes prepared using conventional perfluoropolymers, such as Teflon® AF, Hyflon® AD, and Cytop®.

Claims

1. A process for separating two components, A and B, of a gas fluid mixture having a ratio (Rf) of A:

B, comprising;

(a) passing the gas mixture across a separation membrane having a feed side and a permeate side, the separation membrane having a selective layer comprising a copolymer comprising a perfluorinated dioxolane monomer and a perfluorinated dioxane monomer;

(b) providing a driving force for transmembrane permeation;

(c) withdrawing from the permeate side a permeate stream having a ratio (Rp) of A;

B, where Rp>

Rf; and

(d) withdrawing from the feed side a residue stream having a ratio (Rr) of A;

B, where Rr<

Rf.

2. The process of claim 1, wherein the perfuorinated dioxolane monomer is selected from the group consisting of:

3. The process of claim 1, wherein the perfluorinated dioxane monomer is selected from the group consisting of:

4. The process of claim 1, wherein the selective layer comprises a copolymer having the formula:

5. The process of claim 1, wherein the selective layer comprises a copolymer having the formula:

6. The process of claim 1, wherein the copolymer has a copolymer glass transition temperature, Tg(c), and a homopolymer made from the perfluorinated dioxolane monomer has a homopolymer glass transition temperature, Tg(h), where Tg(c) is at least 10°

C. higher than Tg(h).

7. The process of claim 1, wherein component A is hydrogen.

8. The process of claim 1, wherein component A is carbon dioxide.

9. The process of claim 1, wherein component A is nitrogen.

10. The process of claim 1, wherein component A is helium.

11. The process of claim 1, wherein component B is methane.

12. The process of claim 1, wherein the gas mixture further comprises methane and C₃₊ hydrocarbon vapors.

13. The process of claim 1, wherein component A is nitrogen and component B is methane.

14. The process of claim 1, wherein component A is carbon dioxide and component B is methane.

15. The process of claim 1, wherein component A is hydrogen and component B is methane.

16. The process of claim 1, wherein component A is helium and component B is methane.