Membrane-forming dope for carbon membranes and a method for producing a carbon hollow fiber membrane using the same

• US 10,150,085 B2
• Filed: 10/09/2015
• Issued: 12/11/2018
• Est. Priority Date: 10/30/2014
• Status: Active Grant

• Current Assignee: NOK Corporation
• Original Assignee: NOK Corporation
• Inventors: Kondo, Masataka, Watanabe, Kensuke, Yamamoto, Hirokazu
• Primary Examiner(s): Shumate, Anthony R
• Application Number:
  US15/515,940
• Publication Number:
  US 20170296978A1
• Time in Patent Office: 1,159 Days
• CPC Class Codes: B01D 2053/224 with hollow fibres
• CPC Class Codes: B01D 2323/2181 Inorganic additives
• CPC Class Codes: B01D 53/228 characterised by specific membranes
• CPC Class Codes: B01D 69/08 Hollow fibre membranes manufacture of hollow fibres D01D5/24, D01F1/08
• CPC Class Codes: B01D 69/087 Details relating to the spinning process
• CPC Class Codes: B01D 71/021 Carbon
• CPC Class Codes: C01B 32/05 Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
• CPC Class Codes: Y02C 20/20 of methane

Abstract

A membrane-forming dope for carbon membranes, comprising polyphenylene oxide in an amount giving a concentration of 15 to 40 wt. % in the membrane-forming dope, and sulfur in an amount giving a ratio of 0.1 to 5.0 wt. %, preferably 0.2 to 3.0 wt. %, of the total weight of the polyphenylene oxide and the sulfur, both of which are dissolved in a solvent that can dissolve these components. A hollow fiber carbon membrane is produced by molding the membrane-forming dope for carbon membranes in a hollow shape by means of a wet or dry-wet spinning method using a double tubular nozzle, subjecting the molded product to an infusibilization treatment by heating at 150 to 350° C. in the air, and then subjecting it to a carbonization treatment by heating at 600 to 800° C. in an inert atmosphere or under vacuum. When the product molded in a hollow shape by means of a wet or dry-wet spinning method is subjected to an infusibilization treatment by heating in the air while stretching the product with a stress of 0.002 to 0.005 MPa, a hollow fiber carbon membrane having excellent gas permeability and a further high gas separation factor (He/CH₄) can be obtained.

Claims

1. A membrane-forming dope for carbon membranes, comprising polyphenylene oxide in an amount giving a concentration of 15 to 40 wt. % in the membrane-forming dope, and sulfur in an amount giving a ratio of 0.1 to 5.0 wt. % of the total weight of the polyphenylene oxide and the sulfur, both of which are dissolved in a solvent that can dissolve these components.

2. The membrane-forming dope for carbon membranes according to claim 1, further comprising an organic peroxide, a phenol resin crosslinking agent, or a quinone dioxime crosslinking agent.

3. A method for producing a hollow fiber carbon membrane, comprising molding the membrane-forming dope for carbon membranes according to claim 1 in a hollow shape by means of a wet or dry-wet spinning method using a double tubular nozzle, subjecting the molded product to an infusibilization treatment by heating at 150 to 350°

C. in the air, and then subjecting it to a carbonization treatment by heating at 600 to 800°

C. in an inert atmosphere or under vacuum.

4. The method for producing a hollow fiber carbon membrane according to claim 3, wherein the product molded in a hollow shape by means of a wet or dry-wet spinning method is subjected to an infusibilization treatment by heating in the air while stretching the product with a stress of 0.002 to 0.005 MPa.

5. A hollow fiber carbon membrane produced by the production method according to claim 3.

6. The hollow fiber carbon membrane according to claim 5, wherein the surface is further subjected to chemical vapor deposition using hydrocarbon gas.

7. A hollow fiber carbon membrane produced by the production method according to claim 4.

8. The hollow fiber carbon membrane according to claim 7, wherein the surface is further subjected to chemical vapor deposition using hydrocarbon gas.