Adjusted density carbon for hydrogen PSA

• US 6,027,549 A
• Filed: 04/28/1998
• Issued: 02/22/2000
• Est. Priority Date: 04/28/1998
• Status: Expired due to Term

• Current Assignee: Air Products and Chemicals Incorporated (Linde Plc)
• Original Assignee: Air Products and Chemicals Incorporated (Linde Plc)
• Inventors: Waldron, William Emil, Kratz, Wilbur Clymer, Golden, Timothy Christopher, Farris, Thomas Stephen, Johnson, Charles Henry
• Primary Examiner(s): Spitzer, Robert H.
• Application Number:
  US09/067,742
• Time in Patent Office: 665 Days
• Field of Search: 95/96-98, 95/100-105, 95/139, 95/143, 95/901
• US Class Current: 95/98
• CPC Class Codes: B01D 2253/102 Carbon
• CPC Class Codes: B01D 2253/30 Physical properties of adsorbents
• CPC Class Codes: B01D 2253/304 Linear dimensions, e.g. particle shape, diameter
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2257/7025 Methane
• CPC Class Codes: B01D 2259/4003 with two sub-steps
• CPC Class Codes: B01D 2259/40037 with two sub-steps
• CPC Class Codes: B01D 2259/40041 with more than three sub-steps
• CPC Class Codes: B01D 2259/40052 Recycled product or process gas
• CPC Class Codes: B01D 2259/40067 Seven
• CPC Class Codes: B01D 2259/40075 More than ten
• CPC Class Codes: B01D 2259/4061 using five beds
• CPC Class Codes: B01D 53/047 Pressure swing adsorption
• CPC Class Codes: C01B 2203/042 Purification by adsorption on solids
• 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 2203/0495 the impurity being water
• CPC Class Codes: C01B 2210/0051 Carbon dioxide
• CPC Class Codes: C01B 23/0063 Carbon based materials
• 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

The present invention is a process for adsorbing carbon dioxide from a carbon dioxide containing gas mixture comprising contacting the gas mixture with an activated carbon adsorbent having a density in the range of approximately 0.56 to 0.61 g/cc (35 to 38 lbs./ft³) and adsorbing the carbon dioxide on the activated carbon adsorbent.

Claims

1. A process for adsorbing carbon dioxide and methane from a carbon dioxide and methane containing gas mixture, which also contains a product gas selected from the group consisting of hydrogen, helium and mixtures thereof, comprising contacting said gas mixture with an activated carbon adsorbent having a density in the range of approximately 35 to 38 lbs./ft³ and adsorbing said carbon dioxide and methane on said activated carbon adsorbent, while said product gas is recovered as an unadsorbed product.

2. The process of claim 1 wherein said product gas is hydrogen and said density is approximately 35.5 lbs./ft.³.

3. The process of claim 1 wherein said product gas is helium and said density is approximately 38.0 lbs./ft.³.

4. The process of claim 1 wherein said adsorbent is a bed of adsorbent particles in which the particles have a size in the range of approximately 1 to 3 millimeters in diameter.

5. The process of claim 1 wherein said carbon dioxide and methane are adsorbed on said activated carbon adsorbent in a pressure swing cycle in several parallel-connected beds of said adsorbent, comprising the steps of:

a) contacting said gas mixture with said activated carbon adsorbent with adsorption of carbon dioxide and methane on said activated carbon adsorbent in a first bed from said gas mixture at elevated pressure;

b) discontinuing adsorption and at least partially pressure equalizing said first bed with another bed of said parallel-connected beds of adsorbent;

c) providing purge gas from said first bed to another bed of said parallel-connected beds of adsorbent;

d) depressurizing said first bed to remove adsorbed carbon dioxide and methane from said adsorbent;

e) purging said first bed with purge gas from another bed of said parallel-connected beds of adsorbent to remove adsorbed carbon dioxide and methane;

f) at least partially pressure equalizing said first bed with another bed of said parallel connected beds of adsorbent;

g) repressurizing said first bed with elevated pressure gas mixture or unadsorbed gas from said gas mixture;

h) repeating steps a) through g) in each of said parallel-connected beds.

6. The process of claim 1 wherein said carbon dioxide containing gas mixture further contains carbon monoxide, water, and nitrogen.