Sorbents for the oxidation and removal of mercury

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.

1 - 21 . (canceled) 
     
     
         22 . A method for separating mercury from a mercury and ash containing gas comprising:
 (a) reacting elemental mercury in the mercury and ash containing gas with a promoted halogenated carbon sorbent and with a promoted halogenated non-carbon sorbent to form a mercury/sorbent composition; and   (b) separating the mercury/sorbent composition form the mercury and ash containing gas.   
     
     
         23 . The method of  claim 22  wherein:
 (a) the promoted halogenated carbon sorbent is formed by reacting at least a portion of a carbon sorbent material with a halogen promoter or a halide promoter to form a promoted halogenated carbon sorbent. 
 
     
     
         24 . The method of  claim 23  wherein:
 (a) the carbon sorbent material comprises powdered activated carbon, granular activated carbon, carbon black, unburned carbon, carbon fiber, carbon honeycomb structure, carbon plate structure, aerogel carbon film, pyrolysis char, or regenerated activated carbon from product-promoted carbon sorbent. 
 
     
     
         25 . The method of  claim 23  wherein:
 (a) the carbon sorbent material comprises activated carbon. 
 
     
     
         26 . The method of  claim 23  wherein:
 (a) the carbon sorbent material has a mass mean particle size greater than the ash. 
 
     
     
         27 . The method of  claim 23  wherein:
 (a) the carbon sorbent material has a mass mean particle diameter greater than 40 micrometers. 
 
     
     
         28 . The method of  claim 23  wherein:
 (a) the carbon sorbent material has a mass mean particle diameter greater than 60 micrometers. 
 
     
     
         29 . The method of  claim 23  wherein:
 (a) the carbon sorbent material has a particle-sized distribution greater than the ash. 
 
     
     
         30 . The method of  claim 25  wherein:
 (a) the halogen promoter or the halide promoter reacted with the activated carbon comprises Br 2  or HBr. 
 
     
     
         31 . The method of  claim 23  wherein:
 (a) the halogen promoter or the halide promoter comprises a molecular halogen in vapor or gaseous form, a molecular halogen in an organic solvent, a Group V or Group VI halide in vapor, or a Group V or Group VI halide in liquid. 
 
     
     
         32 . The method of  claim 22  wherein:
 (a) the carbon sorbent material comprises graphene sheets 
 
     
     
         33 . The method of  claim 22  wherein:
 (a) the halogenated non-carbon sorbent is formed by reacting at least a portion of a non-carbon sorbent material with a halogen promoter or a halide promoter to form a promoted halogenated non-carbon sorbent. 
 
     
     
         34 . The method of  claim 29  wherein:
 (a) the non-carbon sorbent material comprises a metal-oxygen-metal structure. 
 
     
     
         35 . The method of  claim 34  wherein:
 (a) the halogenated non-carbon sorbent comprises a metastable complex. 
 
     
     
         36 . The method of  claim 35  wherein:
 (a) the metastable complex comprises a dihalogengroup complexed with a metal-oxygen-metal structure. 
 
     
     
         37 . The method of  claim 35  wherein:
 (a) the metastable complex forms between a halogen promoter and an inorganic species comprising sodium, calcium, magnesium, aluminum, iron compounds, and combinations thereof. 
 
     
     
         38 . The method of  claim 24  wherein:
 (a) the promoted halogenated carbon sorbent is form by injecting the carbon sorbent material and the halogen promoter or the halide promoter into the mercury and ash containing gas. 
 
     
     
         39 . The method of  claim 38  wherein:
 (a) the carbon sorbent material and the halogen promoter or the halide promoter are injected into the mercury and ash containing gas at different locations. 
 
     
     
         40 . The method of  claim 33  wherein:
 (a) the promoted halogenated non-carbon sorbent is form by injecting the non-carbon sorbent material and the halogen promoter or the halide promoter into the mercury and ash containing gas. 
 
     
     
         41 . The method of  claim 40  wherein:
 (a) the non-carbon sorbent material and the halogen promoter or the halide promoter are injected into the mercury and ash containing gas at different locations. 
 
     
     
         42 . A method for separating mercury from a mercury and ash containing gas comprising:
 (a) reacting elemental mercury in the mercury and ash containing gas with a promoted halogenated carbon sorbent and with a promoted halogenated non-carbon sorbent to form a mercury/sorbent composition;
 (i) the promoted halogenated carbon sorbent is formed by reacting at least a portion of a carbon sorbent material with a halogen promoter or a halide promoter to form a promoted halogenated carbon sorbent; and the carbon sorbent material comprises powdered activated carbon, granular activated carbon, carbon black, unburned carbon, carbon fiber, carbon honeycomb structure, carbon plate structure, aerogel carbon film, pyrolysis char, or regenerated activated carbon from product-promoted carbon sorbent; and 
 (ii) the halogenated non-carbon sorbent is formed by reacting at least a portion of a non-carbon sorbent material with a halogen promoter or a halide promoter to form a promoted halogenated non-carbon sorbent; and the non-carbon sorbent material comprises a metal-oxygen-metal structure; and 
   (b) separating the mercury/sorbent composition form the mercury and ash containing gas.   
     
     
         43 . The method of  claim 42  wherein:
 (a) the carbon sorbent material comprises activated carbon. 
 
     
     
         44 . The method of  claim 43  wherein:
 (a) the carbon sorbent material has a mass mean particle size greater than the ash. 
 
     
     
         45 . The method of  claim 42  wherein:
 (a) the carbon sorbent material has a mass mean particle diameter greater than 40 micrometers. 
 
     
     
         46 . The method of  claim 42  wherein:
 (a) the carbon sorbent material has a mass mean particle diameter greater than 60 micrometers. 
 
     
     
         47 . The method of  claim 42  wherein:
 (a) the carbon sorbent material has a particle-sized distribution greater than the ash. 
 
     
     
         48 . The method of  claim 42  wherein:
 (a) the halogen promoter or the halide promoter reacted with the activated carbon comprises Br 2  or HBr. 
 
     
     
         49 . The method of  claim 42  wherein:
 (a) the halogen promoter or the halide promoter comprises a molecular halogen in vapor or gaseous form, a molecular halogen in an organic solvent, a Group V or Group VI halide in vapor, or a Group V or Group VI halide in liquid. 
 
     
     
         50 . The method of  claim 42  wherein:
 (a) the carbon sorbent material comprises graphene sheets 
 
     
     
         51 . The method of  claim 42  wherein:
 (a) the halogenated non-carbon sorbent comprises a metastable complex. 
 
     
     
         52 . The method of  claim 51  wherein:
 (a) the metastable complex comprises a dihalogengroup complexed with a metal-oxygen-metal structure. 
 
     
     
         53 . The method of  claim 51  wherein:
 (a) the metastable complex forms between a halogen promoter and an inorganic species comprising sodium, calcium, magnesium, aluminum, iron compounds, and combinations thereof. 
 
     
     
         54 . The method of  claim 42  wherein:
 (a) the promoted halogenated carbon sorbent is form by injecting the carbon sorbent material and the halogen promoter or the halide promoter into the mercury and ash containing gas. 
 
     
     
         55 . The method of  claim 54  wherein:
 (a) the carbon sorbent material and the halogen promoter or the halide promoter are injected into the mercury and ash containing gas at different locations. 
 
     
     
         56 . The method of  claim 42  wherein:
 (a) the promoted halogenated non-carbon sorbent is form by injecting the non-carbon sorbent material and the halogen promoter or the halide promoter into the mercury and ash containing gas. 
 
     
     
         57 . The method of  claim 42  wherein:
 (a) the non-carbon sorbent material and the halogen promoter or the halide promoter are injected into the mercury and ash containing gas at different locations.