Carbon dioxide gas absorbent containing lithium silicate

• US 6,387,845 B1
• Filed: 03/16/2000
• Issued: 05/14/2002
• Est. Priority Date: 03/23/1999
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Ohashi, Toshiyuki, Masahiro, Kato, Essaki, Kenji, Nakagawa, Kazuaki, Yoshikawa, Sawako
• Primary Examiner(s): BOS, STEVEN J
• Application Number:
  US09/527,229
• Publication Number:
  US 20020037810A1
• Time in Patent Office: 789 Days
• Field of Search: 423/332, 423/333, 423/334, 423/265, 423/275, 423/230, 502/407
• US Class Current: 502/407
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01J 20/0211 Compounds of Ti, Zr, Hf
• CPC Class Codes: B01J 20/041 Oxides or hydroxides
• CPC Class Codes: B01J 20/043 Carbonates or bicarbonates, e.g. limestone, dolomite, aragonite
• CPC Class Codes: B01J 20/06 comprising oxides or hydroxides of metals not provided for in group B01J20/04
• CPC Class Codes: B01J 20/10 comprising silica or silicate
• CPC Class Codes: B01J 20/28004 Sorbent size or size distribution, e.g. particle size
• CPC Class Codes: B01J 20/28054 characterised by their surface properties or porosity
• CPC Class Codes: B01J 20/3007 Moulding, shaping or extruding
• CPC Class Codes: B01J 20/3021 Milling, crushing or grinding
• CPC Class Codes: B01J 20/3078 Thermal treatment, e.g. calcining or pyrolizing
• 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: 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

Abstract

Disclosed is a carbon dioxide gas absorbent containing lithium silicate reacting with a carbon dioxide gas to form lithium carbonate and represented by the general formula, Li_xSi_yO_z, where x, y, z are integers meeting the requirement of x+4y−2z=0. The lithium content x in the general formula should desirably be at least 4.

Claims

1. A carbon dioxide gas absorbent containing

lithium silicate;

and

an alkali carbonate selected from the group consisting of sodium carbonate and potassium carbonate, wherein

the lithium silicate is represented by the general formula;

2. The carbon dioxide gas absorbent according to claim 1, wherein the lithium silicate is in the form of a porous body.

3. The carbon dioxide gas absorbent according to claim 2, wherein the porous body contains particles having an average particle diameter of 0.1 to 5 mm.

4. The carbon dioxide gas absorbent according to claim 2, wherein the porosity of the porous body is in a range from 30% to 50%.

5. The carbon dioxide gas absorbent according to claim 1, further comprising at least one element as an auxiliary component selected from the group consisting of Al, K, Mg, Ca, Na, Fe, Ti and C.

6. The carbon dioxide gas absorbent according to claim 5, wherein the content of the auxiliary component is not higher than 5 wt %.

21. The carbon dioxide gas absorbent according to claim 1, wherein the content of said alkali carbonate is 5 to 30 mol %.

22. The carbon dioxide gas absorbent according to claim 21, wherein the content of said alkali carbonate is 10 to 20 mol %.

7. A carbon dioxide gas absorbent containing lithium silicate powder having an average particle diameter of 0.1 to 50 μ

m and represented by the general formula;

8. The carbon dioxide gas absorbent according to claim 7, wherein the lithium silicate powder is in the form of a porous body.

9. The carbon dioxide gas absorbent according to claim 8, wherein the porosity of the porous body is in a range from 30% to 50%.

10. The carbon dioxide gas absorbent according to claim 7, further comprising at least one element as an auxiliary component selected from the group consisting of Al, K, Mg, Ca, Na, Fe, Ti and C.

11. The carbon dioxide gas absorbent according to claim 10, wherein the content of the auxiliary component is not higher than 5 wt %.

12. The carbon dioxide gas absorbent according to claim 7, wherein the average particle diameter of the lithium silicate powder is in a range from 0.5 to 10 μ

m.

23. The carbon dioxide gas absorbent according to claim 7, wherein the content of said alkali carbonate is 5 to 30 mol %.

24. The carbon dioxide gas absorbent according to claim 23, wherein the content of said alkali carbonate is 10 to 20 mol %.

13. A carbon dioxide gas absorbent containing porous lithium silicate particles having an average particle diameter in a range from 0.1 to 5 mm and represented by the general formula:

14. The carbon dioxide gas absorbent according to claim 13, wherein the porosity of the porous lithium silicate particles is in a range from 30 to 50%.

15. The carbon dioxide gas absorbent according to claim 13, further comprising at least one element as an auxiliary component selected from the group consisting of Al, K, Mg, Ca, Na, Fe, Ti and C.

16. The carbon dioxide gas absorbent according to claim 15, wherein the content of the auxiliary component is not higher than 5 wt %.

25. The carbon dioxide gas absorbent according to claim 13, wherein the content of said alkali carbonate is 5 to 30 mol %.

26. The carbon dioxide gas absorbent according to claim 25, wherein the content of said alkali carbonate is 10 to 20 mol %.

17. A carbon dioxide gas absorbent containing lithium silicate represented by the general formula:

18. The carbon dioxide gas absorbent according to claim 17, wherein the porosity of the porous molded body is in a range from 30% to 50%.

19. The carbon dioxide gas absorbent according to claim 17, further comprising at least one element as an auxiliary component selected from the group consisting of Al, K, Mg, Ca, Na, Fe, Ti and C.

20. The carbon dioxide gas absorbent according to claim 19, wherein the content of the auxiliary component is not higher than 5 wt %.

27. The carbon dioxide gas absorbent according to claim 17, wherein the content of said alkali carbonate is 5 to 30 mol %.

28. The carbon dioxide gas absorbent according to claim 27, wherein the content of said alkali carbonate is 10 to 20 mol %.