High temperature CO2 capture using engineered eggshells: a route to carbon management

• US 7,678,351 B2
• Filed: 03/17/2006
• Issued: 03/16/2010
• Est. Priority Date: 03/17/2005
• Status: Active Grant

• Current Assignee: Ohio State University
• Original Assignee: Ohio State University
• Inventors: Iyer, Mahesh V., Fan, Liang-Shih
• Primary Examiner(s): Langel; Wayne
• Assistant Examiner(s): IQBAL, SYED TAHA
• Application Number:
  US11/384,011
• Publication Number:
  US 20060211571A1
• Time in Patent Office: 1,460 Days
• Field of Search: 502/400, 502/418, 423/637, 423/155, 423/173, 423/176, 423/175, 423/177, 423/635, 423/655, 423/653, 423/230
• US Class Current: 423/175
• CPC Class Codes: B01J 20/043 Carbonates or bicarbonates, e.g. limestone, dolomite, aragonite
• CPC Class Codes: B01J 20/20 comprising free carbon; comprising carbon obtained by carbonising processes
• CPC Class Codes: B01J 20/3078 Thermal treatment, e.g. calcining or pyrolizing
• CPC Class Codes: B01J 2220/4881 Residues from shells, e.g. eggshells, mollusk shells
• CPC Class Codes: C10J 2300/0996 Calcium-containing inorganic materials, e.g. lime
• CPC Class Codes: C10J 2300/1646 integrated with a fuel cell gasification of solids in fuel cells H01M8/0643
• CPC Class Codes: C10J 2300/1653 integrated in a gasification combined cycle [IGCC] engines driven by heat coming from a gasification or pyrolysis unit F01K23/067
• CPC Class Codes: C10J 2300/1678 with air separation separating gases using rectification of air F25J3/04521
• CPC Class Codes: C10J 2300/1807 Recycle loops, e.g. gas, solids, heating medium, water
• CPC Class Codes: C10J 3/482 Gasifiers with stationary fluidised bed
• CPC Class Codes: C10J 3/86 combined with waste-heat boilers
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02E 20/18 Integrated gasification combined cycle [IGCC], e.g. combined with carbon capture and storage [CCS]

Abstract

Applying an acid treatment to eggshells provides a sorbent with unexpectedly high CO₂ capture capacity and ability to regenerate.

Claims

1. A method for producing a sorbent, said method comprising the steps of:

obtaining an eggshell;

treating said eggshell with an acid so as to form an acid treated eggshell; and

calcining said acid treated eggshell so as to produce said sorbent.

2. The method according to claim 1 wherein said calcining is conducted under at least partial vacuum.

3. The method according to claim 1 wherein said calcining is conducted by steam.

4. The method according to claim 1 wherein said acid is acetic acid.

5. The method according to claim 1 wherein said acid is in a concentration of from about 1M to about 10M.

6. A method for producing a sorbent, said method comprising the steps of:

obtaining an eggshell;

treating said eggshell with an acid to separate an organic membrane from said eggshell so as to form an acid treated eggshell; and

calcining said acid treated eggshell so as to produce said sorbent.

7. The method according to claim 6 wherein said calcining is conducted under at least partial vacuum.

8. The method according to claim 6 wherein said calcining is conducted by steam.

9. The method according to claim 6 wherein said acid is acetic acid.

10. The method according to claim 6 further comprising cooling said sorbent in flowing N₂.

11. A method for producing a sorbent, said sorbent method comprising the steps of:

obtaining an eggshell;

treating the said eggshell with an acid to separate an organic membrane from said eggshell;

calcining said eggshell;

hydrating said eggshell so as to form a hydrated eggshell; and

calcining the said hydrated eggshell to so as to produce said sorbent.

12. The method according to claim 11 wherein said calcining is conducted under at least partial vacuum.

13. The method according to claim 11 wherein said calcining is conducted by steam.

14. The method according to claim 11 further comprising cooling the calcined eggshell in flowing N₂.

15. The method according to claim 11 wherein water is used to hydrate the eggshell.

16. The method according to claim 11 wherein the eggshell is calcined in N₂.

17. The method according to claim 11 wherein the eggshell is calcined at about 700°

C.

18. The method according to claim 11 wherein the eggshell is dried at 100°

C. in flowing air.

19. A method for producing a sorbent, said method comprising the steps of:

obtaining an eggshell;

treating said eggshell with an acid to separate an organic membrane from said eggshell so as to form an acid treated eggshell; and

calcining said acid treated eggshell so as to produce said sorbent, wherein said sorbent has a CO₂ capture capacity of at least about 56% in a first cycle.

20. The method of claim 19 wherein said calcining is conducted under partial pressure.