Method for removing carbon monoxide from reformed gas

• US 5,612,012 A
• Filed: 05/26/1995
• Issued: 03/18/1997
• Est. Priority Date: 06/08/1994
• Status: Expired due to Term

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Soma, Takao, Isomura, Manabu, Takahashi, Tomonori
• Primary Examiner(s): Jones, Deborah
• Assistant Examiner(s): HARDING, AMY MARIE
• Application Number:
  US08/451,367
• Time in Patent Office: 662 Days
• Field of Search: 423/210, 423/230, 423/247, 423/658.3, 429/13, 123/DIG. 12, 502/325, 502/333, 502/346, 502/350, 48/198.3
• US Class Current: 423/246
• CPC Class Codes: C01B 2203/0405 Purification by membrane separation
• CPC Class Codes: C01B 2203/041 In-situ membrane purification during hydrogen production
• CPC Class Codes: C01B 2203/0445 Selective methanation
• CPC Class Codes: C01B 2203/047 the impurity being carbon monoxide
• CPC Class Codes: C01B 2203/0475 the impurity being carbon dioxide
• CPC Class Codes: C01B 2203/0495 the impurity being water
• CPC Class Codes: C01B 3/501 by diffusion
• CPC Class Codes: C01B 3/505 Membranes containing palladium
• CPC Class Codes: C01B 3/586 the reaction being a methanation reaction
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 8/0612 from carbon-containing material
• CPC Class Codes: H01M 8/0662 Treatment of gaseous reactants or gaseous residues, e.g. cleaning
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A method for removing CO from a reformed gas includes the steps of treating the reformed gas by a hydrogen purifier to decrease a ratio of the concentration of components other than hydrogen to the concentration of hydrogen so that the ratio may be lower than in the reformed gas, and then converting CO contained in the gas treated by the hydrogen purifier into a gas other than CO. CO can be removed from the reformed gas, and simultaneously high-purity hydrogen can also be obtained, which leads to the increase of a fuel efficiency and the inhibition effect of performance deterioration.

Claims

1. A method for removing carbon monoxide from a reformed gas said method comprising the steps of providing a reformed gas containing hydrogen, carbon dioxide, carbon monoxide and water, treating the reformed gas by subjecting said gas to a hydrogen purifier to reduce the concentration of carbon dioxide, carbon monoxide and water thereby decreasing the ratio of the concentration of components other than hydrogen to the concentration of hydrogen and then converting the carbon monoxide contained in the treated gas into a gas other than carbon monoxide.

2. A method for removing carbon monoxide from a reformed gas according to claim 1, wherein the hydrogen purifier is a hydrogen separating apparatus comprising an alloy containing Pd.

3. A method for removing carbon monoxide from a reformed gas according to claim 2, wherein the hydrogen separating apparatus comprises a porous substrate and a Pd alloy film formed on the porous substrate.

4. A method for removing carbon monoxide from a reformed gas according to claim 2, wherein the hydrogen separating apparatus further comprises a carbon monoxide converting catalyst.

5. A method for removing carbon monoxide from a reformed gas according to claim 2, wherein the hydrogen separating apparatus has an operation temperature of 200°

C. or more.

6. A method for removing carbon monoxide from a reformed gas according to claim 2, wherein the carbon monoxide is converted into a gas other than carbon monoxide using a catalyst.

7. A method for removing carbon monoxide from a reformed gas according to claim 6, wherein the catalyst is integrally combined with the hydrogen separating apparatus.

8. A method for removing carbon monoxide from a reformed gas according to claim 1, wherein the hydrogen purifier regulates the volume ratio of hydrogen to carbon monoxide to 200 or more.

9. A method for removing carbon monoxide from a reformed gas according to claim 1, wherein a carbon monoxide converter is used to convert carbon monoxide into a gas other than carbon monoxide.

10. A method for removing carbon monoxide from a reformed gas according to claim 9, wherein an operation temperature of the carbon monoxide converter is in the range of 100°

to 500°

C.