Adsorbent with improved mass transfer for a VSA or PSA process

• US 6,607,584 B2
• Filed: 03/18/2002
• Issued: 08/19/2003
• Est. Priority Date: 03/16/2001
• Status: Active Grant

• Current Assignee: L'Air Liquide SA
• Original Assignee: L'Air Liquide SA
• Inventors: Moreau, Serge, Badiche, Xavier
• Primary Examiner(s): Spitzer, Robert H.
• Application Number:
  US10/098,447
• Publication Number:
  US 20030015092A1
• Time in Patent Office: 519 Days
• Field of Search: 95/96--06, 951/30, 951/38--40, 959/02, 951/17, 951/43--47, 961/08, 961/30, 961/43, 961/44
• US Class Current: 95/117
• CPC Class Codes: B01D 2253/3425 Honeycomb shape
• CPC Class Codes: B01D 2256/12 Oxygen
• CPC Class Codes: B01D 2257/102 Nitrogen
• CPC Class Codes: B01D 2257/108 Hydrogen
• CPC Class Codes: B01D 2257/502 Carbon monoxide
• 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 53/0476 Vacuum pressure swing adsorption
• CPC Class Codes: B01J 20/00 Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
• CPC Class Codes: B01J 20/28011 Other properties, e.g. density, crush strength
• CPC Class Codes: B01J 20/28014 characterised by their form
• CPC Class Codes: Y10S 95/902 Molecular sieve

Abstract

A formed adsorbent material includes an adsorbent solid phase and a gas phase ensuring transport of the gaseous components right to the adsorbent, being such that the constants for the transport kinetics of the components adsorbable in the gas phase and in the solid phase are in a ratio of between 0.1 and 10 defined for a gas discharge velocity of 0.2 m/s measured on air at 1 bar and 20° C. or in a ratio of between 0.1 and 10, defined for a gas discharge velocity of 0.01 m/s measured on hydrogen at 30 bar and 40° C.

Claims

1. Process for separating or purifying a gas mixture which comprises adsorbing at least one gaseous compound from said gas mixture on an adsorbent material comprising an adsorbent solid phase and a gas phase ensuring transport of the gaseous components right to the adsorbent phase, said adsorbent material being such that the constants for the transport kinetics of the components adsorbable in the gas phase and in the solid phase are in a ratio of between 0.1 and 10 defined for a gas discharge velocity of 0.2 m/s measured on air at 1 bar and 20°

C.

2. Process according to claim 1, wherein the gas mixture contains oxygen and nitrogen and at least some of the nitrogen is adsorbed on the adsorbent material so as to produce an oxygen-enriched gas stream.

3. Process according to claim 1, wherein the gas mixture to be purified contains hydrogen and at least one impurity selected from the group consisting of CO, CH₄, CO₂, O₂, and N₂ and at least some of the impurities are adsorbed on the adsorbent material so as to produce a hydrogen-enriched gas stream.

4. Process according to claim 3, wherein the gas mixture contains at least hydrogen and CO.

5. Process according to claim 1, wherein the gas mixture to be purified is air containing at least one impurity selected from the group consisting of CO₂ and H₂O and at least some of the impurities are adsorbed on the adsorbent material so as to produce purified air stripped of at least some of the impurities, the purified air being subsequently subjected to a cryogenic distillation step.

6. Process for separating or purifying a gas mixture which comprises adsorbing at least one gaseous compound from said gas mixture on an adsorbent material comprising an adsorbent solid phase and a gas phase ensuring transport of the gaseous components right to the adsorbent phase, said adsorbent material being such that the constants four the transport kinetics of the components adsorbable in the gas phase and in the solid phase are in a ratio of between 0.1 and 10 defined for a gas discharge velocity of 0.01 m/s measured on hydrogen at 30 bar and 40°

C.

7. Formed adsorbent material comprising an adsorbent solid phase and a gas phase ensuring transport of the gaseous components right to the absorbent phase, said material being such that the constants for the transport kinetics of the components adsorbable in the gas phase and in the solid phase are in a ratio of between 0.1 and 10 defined for a gas discharge velocity of 0.2 m/s measured on air at 1 bar and 20°

C.

8. Adsorbent material according to claim 7, wherein the ratio is between 0.5 and 4.

9. Adsorbent material according to claim 7, wherein said adsorbent material is such that the head losses for a gas discharge velocity of 0.2 m/s are between 250 and 75,000 Pa/m.

10. Adsorbent material according to claim 9, wherein the head loss is between 500 and 35,000 Pa/m.

11. Adsorbent material according to claim 7, used in a cycle such that the velocity of the gas through the adsorbent exceeds 0.3 m/s.

12. Adsorbent material according to claim 11, wherein the velocity of the gas is greater than 0.4 m/s.

13. Adsorbent material according to claim 7, wherein the gas phase has a mean dimension ranging between 0.01 and 1 mm for ensuring convective transport of the gas.

14. Adsorbent material according to claim 13, wherein the mean dimension of the gas phase is between 0.01 and 0.3 mm.

15. Formed adsorbent material comprising an adsorbent solid phase and a gas phase ensuring transport of the gaseous components right to the adsorbent phase, said material being such that the constants for the transport kinetics of the components adsorbable in the gas phase and in the solid phase are in a ratio of between 0.1 and 10 defined for a gas discharge velocity of 0.01 m/s measured on hydrogen at 30 bar and 40°

C.

16. Adsorbent material according to claim 15, wherein the ratio is between 0.5 and 4.

17. Adsorbent material according to claim 16, wherein said adsorbent material is such that the head losses for a gas discharge velocity of 0.2 m/s are between 250 and 75,000 Pa/m.