Process for the production of hydrogen using a carbonated adsorbent with selected dubinin parameters

• US 6,425,939 B1
• Filed: 10/25/2000
• Issued: 07/30/2002
• Est. Priority Date: 10/26/1999
• Status: Expired due to Fees

• Current Assignee: L'Air Liquide SA
• Original Assignee: L'Air Liquide SA
• Inventors: Polster, Bernd, Moreau, Serge
• Primary Examiner(s): Spitzer, Robert H.
• Application Number:
  US09/695,087
• Time in Patent Office: 643 Days
• Field of Search: 951/16, 951/17, 951/28, 951/30, 951/32, 951/36, 951/39, 951/40, 951/43--47, 959/01, 959/03, 95/96--06
• US Class Current: 95/117
• CPC Class Codes: B01D 2253/102 Carbon
• CPC Class Codes: B01D 2253/108 Zeolites
• CPC Class Codes: B01D 2253/1085 characterized by a silicon-aluminium ratio
• CPC Class Codes: B01D 2253/304 Linear dimensions, e.g. particle shape, diameter
• CPC Class Codes: B01D 2253/308 Pore size
• CPC Class Codes: B01D 2256/16 Hydrogen
• CPC Class Codes: B01D 2257/102 Nitrogen
• CPC Class Codes: B01D 2257/2025 Chlorine
• CPC Class Codes: B01D 2257/304 Hydrogen sulfide
• CPC Class Codes: B01D 2257/406 Ammonia
• 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 2257/7022 Aliphatic hydrocarbons
• CPC Class Codes: B01D 2257/80 Water
• CPC Class Codes: B01D 2259/402 using two beds
• 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 53/04 with stationary adsorbents B01D53/025 takes precedence
• CPC Class Codes: B01D 53/047 Pressure swing adsorption
• CPC Class Codes: B01J 20/18 Synthetic zeolitic molecular sieves
• CPC Class Codes: B01J 20/186 : Chemical treatments in view of modifying the properties of the sieve, e.g. increasing the stability or the activity, also decreasing the activity
• CPC Class Codes: B01J 20/20 : comprising free carbon; comprising carbon obtained by carbonising processes
• CPC Class Codes: B01J 20/28011 : Other properties, e.g. density, crush strength
• CPC Class Codes: B01J 20/28078 : Pore diameter
• CPC Class Codes: B01J 2220/42 : Materials comprising a mixture of inorganic materials materials coated or impregnated on a carrier B01J20/32
• CPC Class Codes: Y02C 20/40 : of CO2
• CPC Class Codes: Y10S 95/901 : Activated carbon

Abstract

A process for the purification of a gaseous hydrogen flow containing one or more gaseous impurities from the group consisting of carbon monoxide, water vapor, nitrogen, H₂S, chlorine, C₁-C₃ light alcohols, ammonia, carbon dioxide and linear, branched or cyclic hydrocarbons, saturated and unsaturated, C₁-C₈. The hydrogen flow is placed in contact with a porous carbonated adsorbent having an adsorption limit volume (W₀) and an energy parameter of (E₀) according to the Dubinin relationship, such that:

0.18 ml.g⁻¹≦W₀≦1.50 ml.g⁻¹

and

15 kJ.mole⁻¹≦E₀≦45 kJ.mole⁻¹.

The porous carbonated adsorbent is selected from active carbons. The gas rich in hydrogen is a reforming gas, an electrolysis gas, a gas from ammonia cracking or from alcohol cracking.

Claims

1. Process for the purification of a flow of gaseous hydrogen containing at least one gaseous impurity selected from the group consisting of carbon monoxide, water vapor, nitrogen, H₂S, carbon dioxide, chlorine, C_1-3 light alcohols, ammonia and linear, branched or cyclic hydrocarbons, saturated or unsaturated, C₁-C₈, which process comprises contacting the flow of gaseous hydrogen to be purified with at least one porous carbonated adsorbent having a limit adsorption volume (W₀) and an energy parameter (E₀) according to the Dubinin relationship wherein:

2. The process according to claim 1, wherein W₀ ranges between 0.20 ml.g⁻

1 and 1.20 ml.g<sup>−

1</sup>.

3. The process according to claim 2, wherein W₀ is greater than or equal to 0.25 ml.g⁻

1.

4. The process according to claim 3, wherein W₀ is greater than or equal to 0.30 ml.g⁻

1.

5. The process according to claim 1, wherein E₀ ranges between 20 kJ.mole⁻

1 and 40 kJ.mole<sup>−

1</sup>.

6. The process according to claim 5, wherein E₀ is greater than or equal to 25 kJ.mole⁻

1.

7. The process according to claim 1, wherein E₀and W₀ are such that:

8. The process according to claim 1, wherein the porous carbonated adsorbent is activated charcoal produced from coconut shell, peat, lignite, anthracite, polymers or resins.

9. The process according to claim 1, wherein the hydrogen flow is a synthesis gas, a reforming gas, an electrolysis gas, a gas from ammonia cracking, a gas from alcohol cracking, or a gaseous mixture containing at least 70% hydrogen.

10. The process according to claim 1, wherein the porous carbonated adsorbent has pores having a size ranging between 0.4 nm and 4 nm.

11. The process according to claim 10, wherein the pores range between 0.5 nm and 2 nm.

12. The process according to claim 1, wherein the process is a PSA process.

13. The process according to claim 1, wherein the process is carried out at an adsorption pressure ranging between 5 and 70 bars, and/or a desorption pressure between 0.1 and 10 bars.

14. The process according to claim 13, wherein the adsorption pressure ranges between 15 and 40 bars, and the desorption pressure between 1 and 5 bars.

15. The process according to claim 1, wherein the hydrogen flow to be purified has a temperature ranging between −

25°

C. and +60°

C.

16. The process according to claim 15, wherein the temperature ranges between +5°

C. and +35°

C.

17. The process according to claim 1, wherein the gaseous hydrogen flow is further contacted with a bed of a zeolitic adsorbent.

18. The process according to claim 17, wherein the zeolitic adsorbent is faujasite zeolite exchanged at least 70% with lithium, and having a Si/Al ratio ranging between 1 and 1.2.

19. The process according to claim 17, wherein the volume ratio of the porous carbonated adsorbent to the zeolitic adsorbent ranges between 10/90 and 90/10.

20. The process according to claim 19, wherein the volume ratio ranges between 50/50 and 80/20.