Purification of gases

• US 6,093,379 A
• Filed: 12/04/1998
• Issued: 07/25/2000
• Est. Priority Date: 12/04/1998
• Status: Expired due to Term

• Current Assignee: Air Products and Chemicals Incorporated (Linde Plc)
• Original Assignee: Air Products and Chemicals Incorporated (Linde Plc)
• Inventors: Schwarz, Alexander, Golden, Timothy Christopher, Taylor, Fred William, Hsiung, Thomas Hsiao-Ling
• Primary Examiner(s): Griffin, Steven P.
• Assistant Examiner(s): Vanoy, Timothy C
• Application Number:
  US09/206,184
• Time in Patent Office: 599 Days
• Field of Search: 95/139, 95/140, 95/117, 423/248, 423/247, 423/437.2, 423/230
• US Class Current: 423/230
• CPC Class Codes: B01D 2253/104 Alumina
• CPC Class Codes: B01D 2253/108 Zeolites
• CPC Class Codes: B01D 2256/10 Nitrogen
• CPC Class Codes: B01D 2256/12 Oxygen
• CPC Class Codes: B01D 2257/502 Carbon monoxide
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2257/80 Water
• CPC Class Codes: B01D 2259/402 using two beds
• CPC Class Codes: B01D 2259/4146 Contiguous multilayered adsorbents
• CPC Class Codes: B01D 2259/416 involving cryogenic temperature treatment
• CPC Class Codes: B01D 53/04 with stationary adsorbents B01D53/025 takes precedence
• CPC Class Codes: B01D 53/864 Removing carbon monoxide or hydrocarbons
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

Carbon dioxide, water, carbon monoxide and hydrogen are removed from a gas stream such as air or nitrogen by adsorbing water and carbon dioxide on a solid absorbent of alumina, or zeolite and oxiding carbon monoxide over a solid catalyst to carbon dioxide and adsorbing the resulting carbon dioxide and chemisorbing the hydrogen on the catalyst, which may be palladium on alumina.

Claims

1. A process for the removal of carbon dioxide, water, carbon monoxide and hydrogen from a gas stream to produce a purified gas stream, comprising:

adsorbing water and carbon dioxide on a solid adsorbent, and then converting carbon monoxide to carbon dioxide over a single solid catalyst, adsorbing the carbon dioxide so formed onto the same catalyst and chemisorbing H₂ onto the same catalyst, wherein said catalyst is a precious metal supported on a support having a zpc (zero point charge) of greater than 8.0.

2. A process as claimed in claim 1, wherein said catalyst is palladium supported on alumina.

3. A process as claimed in claim 1, wherein the carbon monoxide content of the purified gas stream is no more than 5 ppb.

4. A process as claimed in claim 3, wherein said carbon monoxide content is no more than 3 ppb.

5. A process as claimed in claim 1, wherein the hydrogen content of the purified gas stream is no more than 5 ppb.

6. A process as claimed in claim 5, wherein said hydrogen content is no more than 3 ppb.