Removal of carbon dioxide from air

• US 8,088,197 B2
• Filed: 07/28/2006
• Issued: 01/03/2012
• Est. Priority Date: 07/28/2005
• Status: Active Grant

• Current Assignee: Carbon Sink, Inc.
• Original Assignee: Kilimanjaro Energy, Inc.
• Inventors: Wright, Allen B., Lackner, Klaus S., Wright, Burton, Wallen, Matt, Ginster, Ursula, Peters, Eddy J.
• Primary Examiner(s): Smith, Duane
• Application Number:
  US11/996,615
• Publication Number:
  US 20090294366A1
• Time in Patent Office: 1,985 Days
• Field of Search: 95/45, 95/51, 95/96, 951/39, 45/96, 451/39, 96/4, 96/11, 961/08, 961/21, 96134-135, 961/54
• US Class Current: 95/51
• CPC Class Codes: B01D 2253/206 Ion exchange resins
• CPC Class Codes: B01D 2253/25 Coated, impregnated or composite adsorbents
• CPC Class Codes: B01D 2253/3425 Honeycomb shape
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• 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 53/1418 Recovery of products
• CPC Class Codes: B01D 53/1425 Regeneration of liquid absorbents
• CPC Class Codes: B01D 53/1475 Removing carbon dioxide
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02W 10/37 using solar energy

Abstract

The present invention is directed to methods for removing CO₂ from air, which comprises exposing sorbent covered surfaces to the air. The invention also provides for an apparatus for exposing air to a CO₂ sorbent. In another aspect, the invention provides a method and apparatus for separating carbon dioxide (CO₂) bound in a sorbent.

Claims

1. An apparatus for the capture of CO₂ from ambient air, the apparatus comprising a store of ambient air, an anion exchange material in contact with a flow of said ambient air, and a collector that collects CO₂ separated from said anion exchange material subsequent to the capture of said CO₂ by said anion exchange material.

2. The apparatus of claim 1, characterized by one or more of the following features:

a. wherein the anion exchange material is in the form of a plurality of membranes arranged in a series of flat plates with the ambient air flow parallel to face surfaces of the membranes;

b. wherein the anion exchange material is in the form of a plurality of membranes spaced from one another with membrane spacings of from 1-25 mm, exposed to ambient air flow;

c. wherein the anion exchange material is in the form of a plurality of membranes spaced from one another, and further comprising a powered blower for moving air across surfaces of the membranes;

d. wherein the anion exchange material is in the form of one or more membranes arranged in a corrugated fashion to allow air flow through channels formed by the corrugations;

e. wherein a flow path along the anion exchange material has a length dictated by air flow velocity such that the ambient air is not excessively depleted of CO₂;

f. wherein the anion exchange material is in the form of a plurality of membranes stacked in layers and forming “

pie shaped”

sections assembled into a wheel, rotating on an axle;

g. further including a caustic solution wash for washing captured CO₂ from a surface of the anion exchange material, wherein the wash preferably comprises an amine or a carbonate solution;

h. wherein the anion exchange material is in the form of a continuous sheet which is moved in a serpentine pattern such that the membrane first is exposed to air flow, dipped in a caustic, amine, or carbonate solution, and then exposed to the ambient air repeatedly; and

i. wherein the anion exchange material is in the form of a loose mat of threads or tubes, or a honeycomb structure or a foams structure.

3. A method for the capture of CO₂ from ambient air, the method comprising:

exposing an anion exchange material to a flow of ambient air;

capturing CO₂ from the ambient air with said anion exchange material;

separating said CO₂ from said anion exchange material; and

subsequently collecting said separated CO₂.

4. The method of claim 3, characterized by one or more of the following features:

a. wherein the anion exchange material is in the form of a plurality of membranes arranged in a series of flat plates, and the air is flowed substantially parallel to surfaces of the membranes;

b. wherein the anion exchange material is in the form of a plurality of membranes spaced from one another with membrane spacings of from 1-25 mm, and air is flowed past the membranes without auxiliary boost;

c. wherein the anion exchange material is in the form of a plurality of membranes spaced from one another, and a blower is used to power air flow across surfaces of the membranes;

d. wherein the anion exchange material is in the form of a plurality of membranes having membrane surfaces, and further wherein air flow and said membrane surfaces are matched so that the air is not excessively depleted of CO₂;

e. wherein the anion exchange material is in the form of a plurality of membranes stacked in layers and forming “

pie shaped”

sections that are assembled into a wheel, and including the step of rotating the periphery of the wheel through a CO₂ sorbent;

f. including the step of washing the anion exchange material with a wash solution after exposure to the air so as to wash captured CO₂ from the surface of the anion exchange material, so that the anion exchange material can repeatedly act as a CO₂ absorber;

g. including the step of washing the anion exchange material with a wash solution which comprises an amine solution, or a carbonate or bicarbonate solution; and

h. wherein the anion exchange material is in the form of a continuous sheet, and including the steps of moving the sheet in a serpentine pattern such that the sheet is first exposed to air flow, dipped in a wash solution, and then exposed to the air repeatedly.

9. The method of claim 3, 5, or 6, further comprising storing said collected CO₂.

10. The method of claim 3, 5, or 6, whereby amount of CO₂ in said ambient air is reduced.

11. The method of claim 3, wherein said collecting is preceded by a recovery step comprising a thermal swing, a pressure swing, or an electrodialysis process.

12. The method of claim 3, 5, or 6, wherein said anion exchange material comprises an amine.

13. The method of claim 12, wherein said amine is covalently bound to four carbon groups.

14. The method of claim 3, 5, or 6, wherein said anion exchange material is regenerated in a process having a low energy penalty.

15. The method of claim 3, 5, or 6, wherein said anion exchange material comprises a plurality of membranes.

16. The method of claim 15, wherein said plurality of membranes are arranged in series.

17. The method of claim 15, wherein said plurality of membranes are spaced apart from one another with spacing from 1 mm to 25 mm.

18. The method of claim 3, 5, or 6, wherein said anion exchange material has a thickness from 0.1 to 10 mm.

19. The method of claim 15, wherein said plurality of membranes are stacked in layers forming pie shaped sections that are assembled into a wheel.

20. The method of claim 3, 5, or 6, wherein, said anion exchange material comprises tubes.

21. The method of claim 3, 5, or 6, wherein said anion exchange material comprises a foam structure.

22. The method of claim 3, 5, or 6, wherein said anion exchange material comprises a honeycomb structure.

23. The method of claim 22, wherein said anion exchange material comprising a honeycomb structure comprises spacing from 1 mm to 25 mm.

24. The method of claim 22, wherein said honeycomb structure has a thickness from 0.1 mm to 10 mm.

25. The method of claim 3 or 5, further comprising disposing of said separated CO₂ by deep well injection.

5. A method for capturing CO₂ from ambient air, the method comprising:

exposing an anion exchange material to a flow of ambient air;

capturing CO₂ from the ambient air;

releasing said captured CO₂ using a thermal swing, a pressure swing, or an electrodialysis process; and

subsequently collecting said separated CO₂.

7. The method of claim 5, wherein said captured CO₂ is released using a thermal swing.

8. The method of claim 5, wherein said captured CO₂ is released using an electrodialysis process.

6. A method for the capture of CO₂ from ambient air, the method comprising:

exposing an anion exchange material to a flow of ambient air;

capturing CO₂ from the ambient air with said anion exchange material;

separating said CO₂ from said anion exchange material; and

subsequently disposing of said CO₂ by deep well injection.