Methods and systems for selectively separating CO2 from a multicomponent gaseous stream

• US 6,797,039 B2
• Filed: 12/27/2002
• Issued: 09/28/2004
• Est. Priority Date: 12/27/2002
• Status: Expired due to Fees

• Current Assignee: Dwain F. Spencer
• Original Assignee: Dwain F. Spencer
• Inventors: Spencer, Dwain F.
• Primary Examiner(s): SMITH, DUANE
• Application Number:
  US10/331,171
• Publication Number:
  US 20040123738A1
• Time in Patent Office: 641 Days
• Field of Search: 952/36, 951/53, 952/11, 585/15, 962/93, 962/90, 962/99, 423/220, 423/437.1
• US Class Current: 95/153
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: C10K 1/00 Purifying combustible gases containing carbon monoxide isolation of hydrogen from mixtures containing hydrogen and carbon monoxide C01B3/50
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Abstract

Methods are provided for the selective removal of CO₂ from a multicomponent gaseous stream to provide a CO₂ depleted gaseous stream. In practicing the subject methods, an initial multicomponent gaseous stream that includes a gaseous CO₂ hydrate promoter is contacted with an aqueous fluid, e.g., CO₂ nucleated water, in a hydrate formation reactor under conditions of selective CO₂ clathrate formation to produce a CO₂ clathrate slurry and CO₂ depleted gaseous stream. Also provided are systems that find use in practicing the subject methods. The subject methods and systems find use in a variety of applications where it is desired to selectively remove CO₂ from a multicomponent gaseous stream.

Claims

1. A method for removing CO₂ from a multicomponent gaseous stream to produce a CO₂ depleted gaseous stream, said method comprising:

(a) providing a multicomponent gaseous stream comprising a gaseous CO₂ hydrate promoter;

(b) contacting said multicomponent gaseous stream with an aqueous fluid under conditions sufficient to produce CO₂ hydrates, whereby CO₂ is removed from said gaseous stream by said aqueous fluid and concomitantly fixed as CO₂ clathrates upon said contacting to produce a CO₂ depleted gaseous stream and a CO₂ clathrate slurry; and

(c) separating said CO₂ depleted gaseous stream from said CO₂ clathrate slurry to remove CO₂ from said multicomponent gaseous stream;

with the proviso that said method is further characterized by at least one of the following features;

(i) gaseous CO₂ hydrate promoter produced from a recycled source is introduced into said multicomponent gaseous stream comprising said CO₂ hydrate promoter at a time prior to said separating step (c); and

(ii) said contacting step (b) occurs in a finned tubular reactor.

2. The method according to claim 1, wherein gaseous CO₂ hydrate promoter produced from a recycled source is introduced into said multicomponent gaseous stream comprising said CO₂ hydrate promoter at a time prior to said separating step (c).

3. The method according to claim 1, wherein said contacting step (b) occurs in a finned tubular reactor.

4. The method according to claim 1, wherein:

(i) gaseous CO₂ hydrate promoter produced from a recycled source is introduced into said multicomponent gaseous stream comprising said CO₂ hydrate promoter at a time prior to said separating step (c); and

(ii) said contacting step (b) occurs in a finned tubular reactor.

5. The method according to claim 1, wherein said finned tubular reactor comprises a tubular reactor with a helical fin structure.

6. The method according to claim 1, wherein said finned tubular reactor comprises a tubular reactor with a longitudinal fin structure.

7. The method according to claim 1, wherein said aqueous fluid is CO₂ nucleated water.

8. The method according to claim 1, wherein said gaseous CO₂ hydrate promoter in said multicomponent gaseous stream is a low molecular weight compound.

9. The method according to claim 8, wherein said low molecular weight compound is a sulfur-containing compound.

10. The method according to claim 9, wherein said sulfur containing compound is selected from the group consisting of H₂S, SO₂ and CS₂.

11. A system for selectively removing CO₂ from a multicomponent gaseous stream to produce a CO₂ depleted gaseous stream, said system comprising:

(a) a hydrate formation reactor;

(b) a gaseous CO₂ hydrate promoter recovery element for recovering gaseous CO₂ hydrate promoter from a product stream from said reactor; and

(c) a gaseous CO₂ hydrate promoter recycling element for recycling recovered gaseous CO₂ hydrate promoter to said hydrate formation reactor or an input stream thereof.

12. The system according to claim 11, wherein said gaseous CO₂ hydrate promoter recovery element comprises a gaseous CO₂ hydrate promoter absorber and an absorbent/absorbed gaseous CO₂ hydrate promoter separator.

13. The system according to claim 12, wherein said absorbent/absorbed gaseous CO₂ hydrate promoter separator comprises a steam separator.

14. The system according to claim 11, wherein said gaseous CO₂ hydrate promoter recovery element comprises a lean absorbent recycling element for cycling lean absorbent from said separator to said absorber.

15. The system according to claim 11, wherein said hydrate formation reactor comprises a finned tubular reactor.

16. A system for selectively removing CO₂ from a multicomponent gaseous stream to produce a CO₂ depleted gaseous stream comprising a finned tubular hydrate formation reactor.

17. The system according to claim 16, wherein said finned tubular reactor comprises a tubular reactor with a helical fin structure.

18. The system according to claim 16, wherein said finned tubular reactor comprises a tubular reactor with a longitudinal fin structure.

19. The system according to claim 16, wherein said system further comprises a gaseous CO₂ hydrate promoter recovery element for recovering gaseous CO₂ hydrate promoter from a product stream from said reactor.

20. The system according to claim 19, wherein said system further comprises a gaseous CO₂ hydrate promoter recycling element for recycling recovered gaseous CO₂ hydrate promoter to said hydrate formation reactor or an input stream thereof.