Sorbents for the oxidation and removal of mercury

• US 9,468,886 B2
• Filed: 12/11/2013
• Issued: 10/18/2016
• Est. Priority Date: 08/30/2004
• Status: Active Grant

• Current Assignee: Midwest Energy Emissions Corp.
• Original Assignee: Energy & Environmental Research Center (GE Vernova, Inc.)
• Inventors: Olson, Edwin S., Holmes, Michael J., Pavlish, John H.
• Primary Examiner(s): ORLANDO, AMBER ROSE
• Application Number:
  US14/102,896
• Publication Number:
  US 20140099244A1
• Time in Patent Office: 1,042 Days
• Field of Search: 951/34, 951/42, 110/345, 423/210, 423/134, 423/142
• US Class Current: 1/1
• CPC Class Codes: B01D 2253/102 Carbon
• CPC Class Codes: B01D 2257/602 Mercury or mercury compounds
• 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 20/0262 Compounds of O, S, Se, Te
• CPC Class Codes: B01J 20/027 Compounds of F, Cl, Br, I
• CPC Class Codes: B01J 20/04 comprising compounds of alkali metals, alkaline earth metals or magnesium
• 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 20/10 comprising silica or silicate
• CPC Class Codes: B01J 20/106 Perlite
• CPC Class Codes: B01J 20/12 Naturally occurring clays or bleaching earth
• CPC Class Codes: B01J 20/20 comprising free carbon; comprising carbon obtained by carbonising processes
• CPC Class Codes: B01J 20/223 containing metals, e.g. organo-metallic compounds, coordination complexes
• CPC Class Codes: B01J 20/28004 Sorbent size or size distribution, e.g. particle size
• CPC Class Codes: B01J 20/28016 Particle form
• CPC Class Codes: B01J 20/3416 of sorbents or filter aids comprising free carbon, e.g. activated carbon
• CPC Class Codes: B01J 2220/42 Materials comprising a mixture of inorganic materials materials coated or impregnated on a carrier B01J20/32

Abstract

A promoted carbon and/or non-carbon base sorbent are described that are highly effective for the removal of mercury from flue gas streams. The promoted sorbent comprises a carbon and/or non-carbon base sorbent that has reacted with and contains forms of halogen and halides. Optional components may be added to increase and/or preserve reactivity and mercury capacity. These may be added directly with the base sorbent, or in-flight within a gas stream (air, flue gas, etc.), to enhance base sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The promoted sorbent can be regenerated and reused. Base sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active base sorbent into the mercury contaminated gas stream are described.

Claims

1. A method for separating mercury from a mercury and ash containing gas comprising:

chemically reacting at least a portion of a carbon sorbent material and at least a portion of a non-carbon sorbent material with a halogen or a halide promoter to form a promoted halogenated carbon sorbent and a promoted halogenated non-carbon sorbent, wherein the carbon sorbent material comprises activated carbon;

chemically reacting elemental mercury in the mercury containing gas with the promoted halogenated carbon sorbent and the promoted halogenated non-carbon sorbent to form a mercury/sorbent chemical composition; and

separating particulates from the mercury containing gas to form a cleaned gas, the particulates including ash and the mercury/sorbent chemical composition.

2. The method of claim 1, further comprising:

injecting the non-carbon sorbent material and the halogen or halide promoter into the mercury containing gas.

3. The method of claim 2, wherein said halogen or halide promoter and the non-carbon sorbent material are injected into the mercury containing gas at least one of the same location and at separate locations.

4. The method of claim 2, wherein said halogen or halide promoter is injected into the mercury-containing gas upstream of the injection of said non-carbon sorbent material.

5. The method of claim 1, wherein said halogen or halide promoter is introduced into at least one of before a combustion chamber that produces a mercury-containing gas, into a combustion chamber that produces a mercury-containing gas, and after a combustion chamber that produces a mercury-containing gas, and the non-carbon sorbent material is injected downstream of the combustion chamber.

6. The method of claim 5, further comprising:

injecting additional halogen or halide promoter injected downstream of the combustion chamber.

7. The method of claim 2, further comprising:

adjusting the rate of injection of said non-carbon sorbent material or the rate of injection of said promoter or the rate of injection of any combination thereof combination thereof according to a monitored mercury content in the cleaned gas for maintaining the mercury content of the cleaned gas at substantially a desired level.

8. A method for separating mercury from a mercury containing gas comprising:

chemically reacting at least a portion of a carbon sorbent material and at least a portion of a non-carbon sorbent material with a halogen or a halide promoter to form a promoted halogenated carbon sorbent and a promoted halogenated non-carbon sorbent, wherein the carbon sorbent material comprises activated carbon;

chemically reacting elemental mercury in the mercury containing gas with the promoted halogenated carbon sorbent and the promoted halogenated non-carbon sorbent to form a mercury/sorbent chemical composition; and

removing at least some mercury/sorbent chemical composition from the mercury containing gas.

9. The method of claim 8, further comprising:

introducing the non-carbon sorbent material and the halogen or halide promoter into the mercury containing gas, said halogen or halide promoter and the non-carbon sorbent material being introduced into the mercury containing gas at least one of the same location and at separate locations.

10. The method of claim 9, wherein said halogen or halide promoter is introduced into the mercury-containing gas upstream of the injection of said non-carbon sorbent material.

11. The method of claim 10, wherein said halogen or halide promoter is introduced into at least one of before a combustion chamber that produces a mercury-containing gas, into a combustion chamber that produces a mercury-containing-gas, and after a combustion chamber that produces a mercury-containing gas and the non-carbon sorbent material is introduced downstream of the combustion chamber.

12. The method of claim 11, further comprising:

introducing additional halogen or halide promoter injected downstream of the combustion chamber.

13. The method of claim 9, further comprising:

adjusting the rate of introduction of said non-carbon sorbent material or the rate of introduction of said promoter or the rate of introduction of any combination thereof combination thereof according to a monitored mercury content in the cleaned gas for maintaining the mercury content of the cleaned gas at substantially a desired level.

14. A method for separating mercury from a mercury containing gas comprising:

forming a promoted halogenated carbon sorbent and a promoted halogenated non-carbon sorbent by chemically reacting at least a portion of a carbon sorbent material and at least a portion of a non-carbon sorbent material with a halogen or a halide promoter, wherein the carbon sorbent material comprises activated carbon;

forming a mercury/sorbent chemical composition by chemically reacting elemental mercury in the mercury containing gas with the promoted halogenated carbon sorbent and the promoted halogenated non-carbon sorbent; and

removing particulates from the mercury containing gas to form a cleaned gas, the particulates including the mercury/sorbent chemical composition.

15. The method of claim 14, further comprising:

introducing the non-carbon sorbent material and the halogen or halide promoter into the mercury containing gas.

16. The method of claim 15, wherein said halogen or halide promoter and the non-carbon sorbent material are introduced into the mercury containing gas at least one of the same location and at separate locations.

17. The method of claim 15, wherein said halogen or halide promoter is introduced into the mercury-containing gas upstream of the injection of said non-carbon sorbent material.

18. The method of claim 15, wherein said halogen or halide promoter is introduced into at least one of before a combustion chamber that produces a mercury-containing gas, into a combustion chamber that produces a mercury-containing gas, and after a combustion chamber producing a mercury-containing gas and the non-carbon sorbent material is introduced downstream of the combustion chamber.

19. The method of claim 15, wherein said halogen or halide promoter and said non-carbon sorbent material are introduced downstream of a chamber that produces a mercury-containing gas.

20. The method of claim 15, further comprising:

adjusting the rate of introduction of said non-carbon sorbent material or the rate of introduction of said promoter or the rate of introduction of any combination thereof combination thereof according to a monitored mercury content in the cleaned gas for maintaining the mercury content of the cleaned gas at substantially a desired level.