Cross-linkable and cross-linked mixed matrix membranes and methods of making the same

• US 7,806,962 B2
• Filed: 08/19/2008
• Issued: 10/05/2010
• Est. Priority Date: 12/15/2005
• Status: Active Grant

• Current Assignee: UOP Llc (Honeywell International Inc.)
• Original Assignee: UOP Llc (Honeywell International Inc.)
• Inventors: Liu, Chunqing, Wilson, Stephen T., Chiou, Jeffrey J.
• Primary Examiner(s): Greene; Jason M
• Application Number:
  US12/193,897
• Publication Number:
  US 20090031897A1
• Time in Patent Office: 777 Days
• Field of Search: 95/45, 95/50, 95/51, 95/54, 95/55, 96/4, 96/7, 96/8, 96/10, 96/11, 96/12, 96/13, 96/14, 210/640, 210/650, 55D/IG.5
• US Class Current: 95/45
• CPC Class Codes: B01D 2323/30 Cross-linking
• CPC Class Codes: B01D 2323/345 UV-treatment
• CPC Class Codes: B01D 53/228 characterised by specific membranes
• CPC Class Codes: B01D 67/0004 by agglomeration of particles
• CPC Class Codes: B01D 67/009 with wave-energy, particle-radiation or plasma
• CPC Class Codes: B01D 69/02 characterised by their properties
• CPC Class Codes: B01D 69/141 Heterogeneous membranes, e.g. containing dispersed material; Mixed matrix membranes
• CPC Class Codes: B01D 69/1411 containing dispersed material in a continuous matrix
• CPC Class Codes: B01D 71/64 Polyimides; Polyamide-imides; Polyester-imides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: Y02C 20/20 of methane
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y10S 55/05 Methods of making filter

Abstract

The present invention is for novel high performance cross-linkable and cross-linked mixed matrix membranes and the use of such membranes for separations such as for CO₂/CH₄, H₂/CH₄ and propylene/propane separations. More specifically, the invention involves the preparation of cross-linkable and cross-linked mixed matrix membranes (MMMs). The cross-linkable MMMs were prepared by incorporating microporous molecular sieves or soluble high surface area microporous polymers (PIMs) as dispersed microporous fillers into a continuous cross-linkable polymer matrix. The cross-linked MMMs were prepared by UV-cross-linking the cross-linkable MMMs containing cross-linkable polymer matrix such as BP-55 polyimide. Pure gas permeation test results demonstrated that both types of MMMs exhibited higher performance for CO₂/CH₄ and H₂/CH₄ separations than those of the corresponding cross-linkable and cross-linked pure polymer matrices.

Claims

1. A process for separating at least one gas from a mixture of gases, the process comprising:

a) providing a mixed matrix membrane comprising an aromatic polyimide comprising UV-cross-linkable sulfonic groups as a continuous phase and microporous molecular sieves dispersed in the continuous phase wherein said mixed matrix membrane is permeable to said at least one gas;

b) contacting the mixture of gases to a first side of the mixed matrix membrane to cause said at least one gas to permeate the mixed matrix membrane; and

c) removing from a second side of the membrane a permeate gas composition comprising at least a portion of said at least one gas which permeated said membrane.

2. The process of claim 1 wherein said molecular sieves are selected from the group consisting of SAPO-34, Si-DDR, AlPO-14, AlPO-34, AlPO-18, LTA, ERS-12, NaA (4A), CaA (5A), KA (3A), CDS-1, SSZ-62, UZM-9, UZM-13, UZM-17, UZM-19, MCM-65, MCM-47, silicalite-1, Si-MTW, UZM-8, SAPO-31, EU-1, ZSM-57, NU-87, Si-BEA, Si-MEL, FAU, OFF, zeolite L, NaX, NaY, and CaY molecular sieves.

3. A mixed matrix membrane comprising an aromatic polyimide comprising UV-cross-linkable sulfonic groups as a continuous phase and microporous molecular sieves dispersed in said cross-linkable continuous phase.

4. The mixed matrix membrane of claim 3 wherein said molecular sieves are selected from the group consisting of SAPO-34, Si-DDR, AlPO-14, AlPO-34, AlPO-18, LTA, ERS-12, NaA (4A), CaA (5A), KA (3A), CDS-1, SSZ-62, UZM-9, UZM-13, UZM-17, UZM-19, MCM-65, MCM-47, silicalite-1, Si-MTW, UZM-8, SAPO-31, EU-1, ZSM-57, NU-87, Si-BEA, Si-MEL, FAU, OFF, zeolite L, NaX, NaY, and CaY molecular sieves.

5. The mixed matrix membrane of claim 3 wherein said mixed matrix membrane has a geometry selected from the group consisting of sheets, hollow fibers and tubes.

6. A method of making a mixed matrix membrane comprising:

providing an aromatic polyimide comprising UV-cross-linkable sulfonic groups as a continuous phase organic polymer;

providing microporous molecular sieves;

dispersing the microporous molecular sieves into a solution containing the continuous phase organic polymer;

allowing the continuous phase organic polymer to solidify about the microporous molecular sieves to produce a mixed matrix membrane; and

exposing said continuous phase organic polymer to UV radiation for a sufficient period of time to cross-link said continuous phase organic polymer.

7. The method of claim 6 wherein said microporous molecular sieves are selected from the group consisting of SAPO-34, Si-DDR, AlPO-14, AlPO-34, AlPO-18, LTA, ERS-12, NaA (4A), CaA (5A), KA (3A), CDS-1, SSZ-62, UZM-9, UZM-13, UZM-17, UZM-19, MCM-65, MCM-47, silicalite-1, Si-MTW, UZM-8, SAPO-31, EU-1, ZSM-57, NU-87, Si-BEA, Si-MEL, FAU, OFF, zeolite L, NaX, NaY, and CaY molecular sieves.