ENHANCED ADSORBENTS AND METHODS FOR MERCURY REMOVAL

• US 20120020856A1
• Filed: 10/03/2011
• Published: 01/26/2012
• Est. Priority Date: 03/29/2006
• Status: Active Grant

• Current Assignee: Calgon Carbon Corporation (Kuraray Company Limited)
• Original Assignee: Calgon Carbon Corporation (Kuraray Company Limited)
• Inventors: POLLACK, Nicholas R.
• Granted Patent: US 8,409,330 B2
• Time in Patent Office: Days
• US Class Current: 423/210
• CPC Class Codes: B01D 2251/108 Halogens or halogen compounds hydrogen halides B01D2251/50
• CPC Class Codes: B01D 2251/304 of sodium
• CPC Class Codes: B01D 2251/306 of potassium
• CPC Class Codes: B01D 2253/102 Carbon
• CPC Class Codes: B01D 2253/25 Coated, impregnated or composite adsorbents
• CPC Class Codes: B01D 2253/304 Linear dimensions, e.g. particle shape, diameter
• CPC Class Codes: B01D 2257/602 Mercury or mercury compounds
• CPC Class Codes: B01D 2258/0283 Flue gases
• 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 53/025 with wetted adsorbents; Chromatography analytical chromatography G01N30/00 - G01N30/96; for liquids B01D15/08
• CPC Class Codes: B01D 53/08 according to the "moving bed" method
• CPC Class Codes: B01D 53/10 with dispersed adsorbents
• CPC Class Codes: B01D 53/64 Heavy metals or compounds thereof, e.g. mercury
• CPC Class Codes: B01J 20/02 comprising inorganic material
• CPC Class Codes: B01J 20/0229 Compounds of Fe
• CPC Class Codes: B01J 20/0244 Compounds of Zn
• CPC Class Codes: B01J 20/0285 Sulfides of compounds other than those provided for in B01J20/045
• CPC Class Codes: B01J 20/0288 Halides of compounds other than those provided for in B01J20/046
• CPC Class Codes: B01J 20/045 containing sulfur, e.g. sulfates, thiosulfates, gypsum
• CPC Class Codes: B01J 20/046 containing halogens, e.g. halides
• CPC Class Codes: B01J 20/08 : comprising aluminium oxide or hydroxide; comprising bauxite
• CPC Class Codes: B01J 20/103 : comprising silica
• CPC Class Codes: B01J 20/12 : Naturally occurring clays or bleaching earth
• CPC Class Codes: B01J 20/18 : Synthetic zeolitic molecular sieves
• CPC Class Codes: B01J 20/20 : comprising free carbon; comprising carbon obtained by carbonising processes
• CPC Class Codes: B01J 20/28004 : Sorbent size or size distribution, e.g. particle size
• CPC Class Codes: B01J 20/28057 : Surface area, e.g. B.E.T specific surface area
• CPC Class Codes: B01J 20/30 : Processes for preparing, regenerating, or reactivating
• CPC Class Codes: B01J 20/3021 : Milling, crushing or grinding
• CPC Class Codes: Y10S 95/90 : Solid sorbent

Abstract

A flue gas adsorbent and method for making an adsorbent for mercury capture are disclosed. The adsorbent comprises an admixture of an adsorptive material and an additive that have been physically combined thereby eliminating the need for traditional impregnation. A method for removing mercury from a flue gas stream is also disclosed.

Claims

1-20. -20. (canceled)

21. A flue gas adsorbent comprising a dry admixture of a granular activated carbon capable of adsorbing mercury and a granular halide salt, wherein the admixture is in powdered form and wherein the granular halide salt is not disposed on or impregnated into the granular activated carbon.

22. The flue gas adsorbent of claim 21, wherein the halide is bromine.

23. The flue gas adsorbent of claim 21, wherein the additive is a halide salt is a metal halide, wherein said metal is selected from Groups I and II elements of the periodic table of the elements, and said halide is selected from the group consisting of iodide, bromide, and chloride.

24. The flue gas adsorbent of claim 21, wherein said activated carbon has a surface area of at least 200 m²/g.

25. The flue gas adsorbent of claim 21, wherein the granular halide salt comprises about 0.1% to about 20% by weight of the admixture.

26. The flue gas adsorbent admixture of claim 21, wherein the granular halide salt comprises at least 2% by weight of said admixture.

27. The flue gas adsorbent of claim 21, wherein the granular activated carbon and the granular halide salt can be seen as distinct and separate particles on images produced using a scanning electron microscope (SEM).

28. The flue gas adsorbent of claim 21, wherein the admixture is substantially homogenous.

29. The flue gas adsorbent of claim 21, wherein each of the granular activated carbon and the granular halide salt have mean particle diameters of from about 5 μ

m to about 30 μ

m.

30. The flue gas adsorbent of claim 21, wherein each of the granular activated carbon and the granular halide salt have a mean particle diameter of less than 16 μ

m.

31. A method for removing mercury from a flue gas stream comprising contacting the flue gas stream with a dry admixture, the dry admixture comprising a granular activated carbon capable of adsorbing mercury and a granular halide salt wherein the granular halide salt is not disposed on or impregnated into the dry activated carbon during the step of contacting the flue gas stream.

32. The method of claim 31, wherein contacting comprises continuously or intermittently injecting said admixture into said flue gas stream.

33. The method of claim 31, wherein contacting comprises passing the gas stream through a fixed bed of the admixture.

34. The method of claim 31, wherein each of the granular adsorptive material and the granular halide salt have mean particle diameters of from about 5 μ

m to about 30 μ

m.

35. The method of claim 31, wherein each of the granular adsorptive material and the granular halide salt have mean particle diameters of less than 16 μ

m.

36. The method of claim 31, wherein the granular activated carbon and the granular halide salt can be seen as distinct and separate particles on images produced using a scanning electron microscope (SEM).

37. The method of claim 31, wherein the granular activated carbon has a surface area of at least 200 m²/g.

38. The method of claim 31, wherein the granular halide salt comprises about 0.1% to about 20% by weight of the admixture.

39. The method of claim 31, wherein the granular halide salt comprises at least 2% by weight of said admixture.

40. The method of claim 31, wherein the halide is bromine.

41. A method for removing mercury from a flue gas stream comprising contacting the flue gas stream with a dry admixture, the dry admixture comprising a granular activated carbon capable of adsorbing mercury and a granular halogen salt wherein the dry additive is not disposed on or impregnated into the dry activated carbon during the step of contacting the flue gas stream.

42. The method of claim 41, wherein contacting comprises continuously or intermittently injecting said admixture into said flue gas stream.

43. The method of claim 41, wherein the adsorptive material is selected from the group consisting of activated carbon, reactivated carbon, zeolite, silica, silica gel, alumina, alumina clay, and combinations thereof.

44. The method of claim 41, wherein each of the granular adsorptive material and the granular additive have a mean particle diameter of from about 5 μ

m to about 30 μ

m.

45. The method of claim 41, wherein each of the granular adsorptive material and the granular additive have a mean particle diameter of less than 16 μ

m.

46. The method of claim 41, wherein contacting comprises passing the gas stream through a fixed bed of the admixture.

47. The method of claim 41, wherein the halide is bromine.