Manufacturing carbon molecular sieve membranes using a pyrolysis atmosphere comprising sulfur-containing compounds

• US 9,795,927 B2
• Filed: 12/17/2015
• Issued: 10/24/2017
• Est. Priority Date: 12/31/2014
• Status: Active Grant

• Current Assignee: L'Air Liquide Societe Anonyme Pour L'Etude et L'Exploitation Des Procedes Georges Claude (L'Air Liquide SA)
• Original Assignee: L'Air Liquide Societe Anonyme Pour L'Etude et L'Exploitation Des Procedes Georges Claude (L'Air Liquide SA)
• Inventors: Chevrel, Henri, Jurcik, Jr., Benjamin J., Coignet, Philippe A., Swaidan, Raja, Kratzer, Dean W.
• Primary Examiner(s): Greene, Jason M
• Application Number:
  US14/972,980
• Publication Number:
  US 20160184775A1
• Time in Patent Office: 677 Days
• CPC Class Codes: B01D 2256/12 Oxygen
• CPC Class Codes: B01D 2256/16 Hydrogen
• CPC Class Codes: B01D 2256/245 Methane
• CPC Class Codes: B01D 2257/102 Nitrogen
• CPC Class Codes: B01D 2323/10 Specific pressure applied
• CPC Class Codes: B01D 2325/10 Catalysts being present on the surface of the membrane or in the pores
• CPC Class Codes: B01D 53/228 characterised by specific membranes
• CPC Class Codes: B01D 67/0067 by carbonisation or pyrolysis
• CPC Class Codes: B01D 69/08 Hollow fibre membranes manufacture of hollow fibres D01D5/24, D01F1/08
• CPC Class Codes: B01D 71/021 Carbon

Abstract

A carbon molecular sieve (CMS) membrane is made by pyrolyzing a polymeric precursor membrane in a pyrolysis atmosphere containing a sulfur-containing compound.

Claims

1. A method for producing a CMS membrane, comprising the steps of:

forming a polymeric precursor membrane; and

pyrolyzing the polymeric precursor membrane in a pyrolysis atmosphere containing 5 ppm (vol/vol) to 50% (vol/vol) of H₂S in a balance of inert gas.

2. The method of claim 1, wherein the balance gas is N₂, Ar or mixtures thereof.

3. The method of claim 1, wherein the polymeric precursor membrane comprises a separation layer, the separation layer comprising 6FDA:

BPDA/DAM.

4. The method of claim 1, wherein the pyrolysis is conducted at a pressure of 0.25-1.0 bar (abs).

5. The method of claim 1, wherein the polymeric precursor membrane comprises a polyimide comprising alternating units of diamine-derived units and of dianhydride-derived units having the structure of formula I,

6. A CMS membrane produced according to the method of claim 1.

7. A method for separating a gas mixture, comprising the steps of feeding the gas mixture to the CMS membrane of claim 6, withdrawing a permeate gas from a permeate outlet of the CMS membrane, and withdrawing a non-permeate gas from a non-permeate outlet of the CMS membrane that is deficient in at least one gas relative to the gas mixture.