METHODS FOR THE TREATMENT OF FLUE GAS STREAMS USING SORBENT COMPOSITIONS WITH REDUCED AUTO-IGNITION PROPERTIES

• US 20180029009A1
• Filed: 10/10/2017
• Published: 02/01/2018
• Est. Priority Date: 04/07/2015
• Status: Active Grant

• Current Assignee: ARQ Solutions LLC
• Original Assignee: ADA Carbon Solutions, LLC (Advanced Emissions Solutions, Inc.)
• Inventors: Li, Mowen, Vizcaino, Christopher, Lowring, Jacob B., Cayton, Roger H.
• Granted Patent: US 11,148,120 B2
• Time in Patent Office: Days
• CPC Class Codes: B01D 2253/102 Carbon
• CPC Class Codes: B01D 2253/25 Coated, impregnated or composite adsorbents
• 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 53/64 Heavy metals or compounds thereof, e.g. mercury
• CPC Class Codes: B01J 20/0266 Compounds of S
• CPC Class Codes: B01J 20/0281 Sulfates of compounds other than those provided for in B01J20/045
• 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 20/20 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 20/28011 Other properties, e.g. density, crush strength
• CPC Class Codes: B01J 20/28016 Particle form
• CPC Class Codes: B01J 20/28071 being less than 0.5 ml/g
• CPC Class Codes: B01J 20/3204 Inorganic carriers, supports or substrates
• CPC Class Codes: B01J 20/3234 Inorganic material layers
• CPC Class Codes: B01J 20/3236 containing metal, other than zeolites, e.g. oxides, hydroxides, sulphides or salts
• CPC Class Codes: C01B 32/30 Active carbon

Abstract

An activated carbon sorbent composition comprising activated carbon and a passivation agent, wherein the activated carbon sorbent composition exhibits reduced self-heating or auto-ignition properties as compared to the activated carbon. The activated carbon sorbent composition may be utilized to sequester contaminants such as mercury from a flue gas stream. The passivation agent includes a sulfur species, and may be a sulfur oxide compound, a sulfide compound, or an organic sulfur compound. Methods for the manufacture of the activated carbon sorbent composition and for the sequestration of contaminants in a flue gas stream using the composition are also disclosed.

Claims

1. A method for sequestering contaminants from a flue gas stream traversing a flue gas train, the flue gas train comprising a particulate collection device selected from a baghouse and an electrostatic precipitator, the method comprising the steps of:

burning a combustible material to form a flue gas stream comprising contaminants, the contaminants comprising at least mercury;

contacting the flue gas stream with an activated carbon sorbent composition to sequester at least a portion of the contaminants with the activated carbon sorbent composition; and

capturing at least a portion of the sorbent composition in the particulate collection device,

wherein the activated carbon sorbent composition comprises activated carbon and a passivation agent, the passivation agent comprising a sulfur oxide compound selected from the group consisting of;

(i) a nonionic sulfur oxide compound defined by the formula SO_y, where y=2 or 3; and

(ii) an ionic sulfur oxide compound comprising an anion defined by the formula S_xO_y²⁻

, where x=1 or 2 and y=2, 3, 4, 5, or 6.

2. The method recited in claim 1, wherein the combustible material comprises coal.

3. The method recited in claim 1, wherein the activated carbon sorbent composition is in the form of free-flowing particulates.

4. The method recited in claim 3, wherein the contacting step comprises injecting the activated sorbent composition into the flue gas stream.

5. The method recited in claim 1, wherein the sulfur oxide compound is an ionic sulfur oxide compound.

6. The method recited in claim 5, wherein the ionic sulfur oxide compound comprises a cation that is selected from the group consisting of hydrogen, a nitrogen-containing compound, and a metal cation.

7. The method recited in claim 6, wherein the cation is hydrogen.

8. The method recited in claim 7, wherein the ionic sulfur oxide compound is sulfuric acid.

9. The method recited in claim 6, wherein the cation is a nitrogen-containing compound

10. The method recited in claim 9, wherein the nitrogen-containing compound is ammonium.

11. The method recited in claim 10, wherein the ionic sulfur oxide compound is ammonium sulfate.

12. The method recited in claim 9, wherein the nitrogen-containing compound is an alkylammonium compound.

13. The method recited in claim 6, wherein the cation comprises a metal cation.

14. The method recited in claim 13, wherein the metal cation is selected from the group consisting of an alkali metal, an alkaline earth metal and a transition metal.

15. The method recited in claim 14, wherein the metal cation is an alkali metal.

16. The method recited in claim 15, wherein the alkali metal cation is selected from the group consisting of lithium, sodium, and potassium.

17. The method recited in claim 16, wherein the alkali metal is sodium.

18. The method recited in claim 17, wherein the metal cation is an alkaline earth metal.

19. The method recited in claim 18, wherein the alkaline earth metal is selected from the group consisting of magnesium, calcium, and barium.

20. The method recited in claim 14, wherein the metal cation is a transition metal.

21. The method recited in claim 20, wherein the transition metal is selected from the group consisting of zinc, iron, copper, nickel, titanium, manganese, aluminum, and vanadium.

22. The method recited in claim 21, wherein the transition metal is zinc.

23. The method recited in claim 21, wherein the transition metal is iron.

24. The method recited in claim 21, wherein the transition metal is aluminum.

25. The method recited in claim 1, wherein the sorbent composition comprises at least about 0.1 wt. % of the sulfur oxide compound.

26. The method recited in claim 1, wherein the sorbent composition comprises at least about 0.5 wt. % of the sulfur oxide compound.

27. The method recited in claim 1, wherein the sorbent composition comprises not greater than about 40 wt. % of the sulfur oxide compound.

28. The method recited in claim 1, wherein the sorbent composition comprises not greater than about 20 wt. % of the sulfur oxide compound.

29. The method recited in claim 1, wherein the sorbent composition comprises not greater than about 10 wt. % of the sulfur oxide compound.

30. The method recited in claim 1, wherein the sorbent composition comprises not greater than about 5 wt. % of the sulfur oxide compound.

31. The method recited in claim 1, wherein the specific enthalpy of the sorbent composition is at least about 5% lower than the specific enthalpy of the activated carbon.

32. The method recited in claim 1, wherein the specific enthalpy of the sorbent composition is at least about 10% lower than the specific enthalpy of the activated carbon.

33. The method recited in claim 1, wherein the specific enthalpy of the sorbent composition is at least about 20% lower than the specific enthalpy of the activated carbon.

34. The method recited in claim 1, wherein the specific enthalpy of the sorbent composition is at least about 30% lower than the specific enthalpy of the activated carbon.

35. The method recited in claim 1, wherein the specific enthalpy of the sorbent composition is at least about 40% lower than the specific enthalpy of the activated carbon.

36. The method recited in claim 1, wherein the peak oxidation rate of the sorbent composition is at least about 5% lower than the peak oxidation rate of the activated carbon.

37. The method recited in claim 1, wherein the peak oxidation rate of the sorbent composition is at least about 10% lower than the peak oxidation rate of the activated carbon.

38. The method recited in claim 1, wherein the peak oxidation rate of the sorbent composition is at least about 20% lower than the peak oxidation rate of the activated carbon.

39. The method recited in claim 1, wherein the peak oxidation rate of the sorbent composition is at least about 30% lower than the peak oxidation rate of the activated carbon.

40. The method recited in claim 1, wherein the peak oxidation rate of the sorbent composition is at least about 40% lower than the peak oxidation rate of the activated carbon.

41. The method recited in claim 1, wherein the peak oxidation rate of the sorbent composition is at least about 50% lower than the peak oxidation rate of the activated carbon.

42. The method recited in claim 1, further comprising an oxidation agent.

43. The method recited in claim 42, wherein the oxidation agent comprises a halogen species.

44. The method recited in claim 43, wherein the halogen species comprises a bromide salt.

45. The method recited in claim 44, wherein the bromide salt is selected from the group consisting of sodium bromide, ammonium bromide, calcium bromide, lithium bromide and magnesium bromide.

46. The method recited in claim 43, wherein the halogen species comprises an iodine compound selected from the group consisting of iodides, iodates and hypoiodites.

47. The method recited in claim 1, wherein the activated carbon sorbent composition comprises substantially free-flowing particulates of powdered activated carbon.

48. The method recited in claim 47, wherein the powdered activated carbon has a median particle size of not greater than about 20 μ

m.

49. The method recited in claim 47, wherein the powdered activated carbon has a median particle size of at least about 6 μ

m.

50. The method recited in claim 47, wherein the powdered activated carbon has a median particle size of not greater than about 30 μ

m, a particle density of at least about 0.4 g/cc, and a total pore volume of at least about 0.2 cc/g.

51. The method recited in claim 47, wherein the powdered activated carbon has a median particle size of not greater than about 20 μ

m, a particle density of at least about 0.4 g/cc, and a total pore volume of at least about 0.2 cc/g.

52. The method recited in claim 47, wherein the powdered activated carbon has a median particle size of not greater than about 15 μ

m, a particle density of at least about 0.4 g/cc, and a total pore volume of at least about 0.2 cc/g.

53. The method recited in claim 47, wherein the powdered activated carbon has a median particle size of not greater than about 12 μ

m, a particle density of at least about 0.4 g/cc, and a total pore volume of at least about 0.2 cc/g.

54. The method recited in claim 1, wherein the sulfur oxide compound is in the form of a coating on the activated carbon.

55. The method recited in claim 1, wherein the sulfur oxide compound comprises sulfur oxide compound particulates that are admixed with the activated carbon.

56. The method recited in claim 1, wherein the particulate collection device is a baghouse.

57. The method recited in claim 1, wherein the particulate collection device is an electrostatic precipitator.