Activated carbon as sole absorbent in rapid cycle hydrogen PSA

• US 6,660,064 B2
• Filed: 03/08/2002
• Issued: 12/09/2003
• Est. Priority Date: 03/08/2002
• Status: Expired due to Term

• Current Assignee: Air Products and Chemicals Incorporated (Linde Plc)
• Original Assignee: Air Products and Chemicals Incorporated (Linde Plc)
• Inventors: Golden, Timothy Christopher, Weist, Edward Landis
• Primary Examiner(s): Spitzer, Robert H.
• Application Number:
  US10/094,185
• Publication Number:
  US 20030167921A1
• Time in Patent Office: 641 Days
• Field of Search: 95/96--98, 951/00--05, 951/27, 951/30, 951/38--40, 951/43, 959/01, 961/08, 961/30--33, 961/53, 961/54
• US Class Current: 95/96
• CPC Class Codes: B01D 2253/102 Carbon
• CPC Class Codes: B01D 2253/25 Coated, impregnated or composite adsorbents
• CPC Class Codes: B01D 2253/34 Specific shapes
• CPC Class Codes: B01D 2253/342 Monoliths
• CPC Class Codes: B01D 2256/16 Hydrogen
• CPC Class Codes: B01D 2256/20 Carbon monoxide
• CPC Class Codes: B01D 2257/102 Nitrogen
• CPC Class Codes: B01D 2257/104 Oxygen
• CPC Class Codes: B01D 2257/11 Noble gases
• CPC Class Codes: B01D 2257/502 Carbon monoxide
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2257/702 Hydrocarbons
• CPC Class Codes: B01D 2257/7025 Methane
• CPC Class Codes: B01D 2258/0208 from fuel cells
• CPC Class Codes: B01D 53/02 by adsorption, e.g. preparative gas chromatography solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01
• CPC Class Codes: B01D 53/0473 Rapid pressure swing adsorption
• CPC Class Codes: C01B 2203/043 Regenerative adsorption process in two or more beds, one for adsorption, the other for regeneration
• 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 2203/048 the impurity being an organic compound
• CPC Class Codes: C01B 3/56 : by contacting with solids; Regeneration of used solids C01B3/508 takes precedence
• CPC Class Codes: Y02C 20/20 : of methane
• CPC Class Codes: Y02C 20/40 : of CO2
• CPC Class Codes: Y02P 20/151 : Reduction of greenhouse gas [GHG] emissions, e.g. CO2
• CPC Class Codes: Y02P 20/156 : Methane [CH4]
• CPC Class Codes: Y10S 95/901 : Activated carbon

Abstract

A pressure swing adsorption process for recovering a product gas from a feed gas, includes: supplying a pressure swing adsorption apparatus including an adsorbent composition containing activated carbon as a major ingredient, wherein the adsorbent composition and the apparatus are substantially free of zeolite adsorbents; feeding a feed gas into the pressure swing adsorption apparatus during a feed period not exceeding 20 seconds; and recovering the product gas from the pressure swing adsorption apparatus. The process and apparatus are particularly suitable for use with fuel cells and other applications requiring compact, rapid cycling systems for producing high purity hydrogen.

Claims

1. A pressure swing adsorption process for recovering a product gas from a feed gas, said process comprising:

supplying a multiple-bed pressure swing adsorption apparatus comprising an adsorbent composition containing activated carbon as a major ingredient, wherein said adsorbent composition and said apparatus are substantially free of zeolite adsorbents;

feeding a feed gas into said pressure swing adsorption apparatus during a feed period not exceeding 20 seconds, said feed gas comprising a mixture of hydrogen and at least one other member selected from the group consisting of carbon dioxide, carbon monoxide, hydrocarbon, oxygen, methane, argon and nitrogen; and

recovering said product gas from said pressure swing adsorption apparatus, provided that when said product gas is hydrogen a rate of hydrogen recovery is greater than 82%.

2. The process of claim 1, wherein said adsorbent composition consists essentially of activated carbon.

3. The process of claim 2, wherein said adsorbent composition consists of activated carbon.

4. The process of claim 2, wherein said apparatus contains no adsorbent other than said adsorbent composition.

5. The process of claim 2, wherein said apparatus further comprises at least one optional adsorbent composition in addition to said adsorbent composition.

6. The process of claim 2, wherein said adsorbent composition is provided as a monolith, a bed of beads, a bed of granules or a sintered bed.

7. The process of claim 2, wherein said adsorbent composition is provided as a self-supported fabric.

8. The process of claim 2, wherein said adsorbent composition is modified prior to said supplying by impregnation with metal salts, oxidation, reduction and/or ion exchange.

9. The process of claim 2, wherein said adsorbent composition is modified prior to said supplying by impregnation with CuCl.

10. The process of claim 2, wherein said feed gas comprises 30 to 90% H₂, 5 to 25% CO₂, 0.1 to 8% CO, 0.1 to 20% N₂ and 0.1 to 8% CH₄.

11. The process of claim 2, wherein a purity of H₂ in said product gas is not limited by O₂ and/or Ar breakthrough.

12. The process of claim 2, wherein said product gas comprises at least 99.9% hydrogen.

13. The process of claim 2, wherein during said feeding, said feed gas has a feed temperature of 0 to 100°

C. and a feed pressure of 20 to 500 psig (0.14 to 3.4 MPa).

14. In a pressure swing adsorption process having a cycle time not exceeding twenty seconds and comprising contacting an adsorbent with a gaseous mixture to provide a product gas containing hydrogen and a reduced amount of at least one impurity selected from the group consisting of carbon dioxide, carbon monoxide, hydrocarbon, oxygen, methane, argon and nitrogen, the improvement wherein said adsorbent consists essentially of activated carbon, no other adsorbent is used in said process;

the process is conducted in a multiple-bed pressure swing adsorption apparatus and a rate of hydrogen recovery is greater than 82%.

15. The process of claim 14, wherein said adsorbent consists of activated carbon.

16. A multiple-bed pressure swing adsorption process for recovering a product gas from a feed gas, said process comprising:

supplying a multiple-bed pressure swing adsorption apparatus comprising an adsorbent composition consisting essentially of activated carbon, wherein said adsorbent composition and said apparatus are substantially free of zeolite adsorbents;

feeding a feed gas into said pressure swing adsorption apparatus during a feed period not exceeding 20 seconds, said feed gas comprising 30 to 90% H₂, 5 to 25% CO₂, 0.1 to 8% CO, 0.1 to 20% N₂ and 0.1 to 8% CH₄; and

recovering said product gas from said pressure swing adsorption apparatus, provided that when said product gas comprises at least 99.9% hydrogen, a rate of hydrogen recovery is at least 60%.

17. The process of claim 16, wherein the rate of hydrogen recovery is at least 70%.