Mercury Removal sorbent

Abstract

A composition comprising a vanadium oxide compound and an alkali metal promoter loaded onto a porous support material is disclosed. Methods of making and using the composition to remove heavy metals or heavy metal containing compounds from a fluid stream are also provided. Such methods are particularly useful in the removal of mercury and mercury compounds from flue gas streams produced from the combustion of hydrocarbon-containing materials such as coal and petroleum fuels.

1 . A composition comprising a porous support material including a vanadium oxide compound and an alkali metal vanadate incorporated thereon, therein, or thereon and therein.  
     
     
         2 . A composition in accordance with  claim 1  wherein said vanadium oxide compound comprises V 2 O 5 , a hydrate of V 2 O 5 , a peroxo complex of vanadium oxide, or mixtures thereof.  
     
     
         3 . A composition in accordance with  claim 1  wherein said alkali metal vanadate is lithium vanadate.  
     
     
         4 . A composition in accordance with  claim 1  wherein said porous support material is selected from the group consisting of amorphous silica-alumina, a zeolite, a material comprising meta-kaolin, alumina, expanded perlite, and combinations thereof.  
     
     
         5 . A composition in accordance with  claim 1  wherein said porous support material comprises at least about 50% by weight of the total weight of said composition.  
     
     
         6 . A composition in accordance with  claim 1  wherein said composition comprises from about 0.5-40% by weight vanadium.  
     
     
         7 . A composition in accordance with  claim 1  wherein said porous support material has a surface area of at least about 75 m 2 /g.  
     
     
         8 . A composition in accordance with  claim 1  wherein said composition comprises from about 0.5-50% by weight of said alkali metal vanadate.  
     
     
         9 . A composition in accordance with  claim 1  wherein the weight ratio of vanadium oxide to alkali metal vanadate is from about 10:1 to 1:10.  
     
     
         10 . A composition in accordance with  claim 1  wherein said composition further comprises a quantity of an alkali metal hydroxide.  
     
     
         11 . A composition in accordance with  claim 10  wherein said alkali metal hydroxide is lithium hydroxide.  
     
     
         12 . A porous sorbent composition comprising a porous support material impregnated with a vanadium oxide compound and an alkali metal promoter selected from the group consisting of lithium hydroxide, lithium vanadate, and mixtures thereof.  
     
     
         13 . A composition in accordance with  claim 12  wherein said vanadium oxide compound comprises V 2 O 5 , a hydrate of V 2 O 5 , a peroxo complex of vanadium oxide, or mixtures thereof.  
     
     
         14 . A composition in accordance with  claim 12  wherein said porous support material is selected from the group consisting of amorphous silica-alumina, a zeolite, a material comprising meta-kaolin, alumina, expanded perlite, and combinations thereof.  
     
     
         15 . A composition in accordance with  claim 12  wherein said porous support material comprises at least about 50% by weight of the total weight of said composition.  
     
     
         16 . A composition in accordance with  claim 12  wherein said composition comprises from about 0.5-40% by weight vanadium.  
     
     
         17 . A composition in accordance with  claim 12  wherein said porous support material has a surface area of at least about 75 m 2 /g.  
     
     
         18 . A composition in accordance with  claim 12  wherein said composition comprises from about 0.5-50% by weight of said alkali metal promoter.  
     
     
         19 . A composition in accordance with  claim 12  wherein the weight ratio of vanadium oxide to alkali metal hydroxide is from about 10:1 to 1:10.  
     
     
         20 . A method for forming a sorbent material comprising: 
 (a) mixing a vanadium oxide compound and an alkali metal hydroxide promoter with at least one porous support material.    
     
     
         21 . A method in accordance with  claim 20  wherein said method further comprises: 
 (b) dispersing said vanadium oxide and said promoter in a first aqueous solution prior to step (a).    
     
     
         22 . A method in accordance with  claim 21  wherein said first aqueous solution comprises from about 0.5-70% by weight of said vanadium oxide compound and from about 0.05-50% by weight of said promoter.  
     
     
         23 . A method in accordance with  claim 21  wherein said method further comprises: 
 (c) dispersing said porous support components in a second aqueous solution prior to step (a).    
     
     
         24 . A method in accordance with  claim 20  wherein said promoter is lithium hydroxide.  
     
     
         25 . A method in accordance with  claim 20  wherein said at least one porous support material is selected from the group consisting of amorphous silica-alumina, a zeolite, a material comprising meta-kaolin, alumina, expanded perlite, and combinations thereof.  
     
     
         26 . A method in accordance with  claim 20  wherein at least a portion of said alkali metal hydroxide promoter reacts with at least a portion of said vanadium oxide compound to form an alkali metal vanadate.  
     
     
         27 . A method of removing at least one heavy metal or heavy metal containing compound from a fluid stream, said method comprising the step of: 
 (a) contacting said fluid stream with a porous support material having incorporated onto, into, or onto and into a vanadium oxide compound and an alkali metal promoter for sorption of at least a portion of said at least one heavy metal or heavy metal containing compound.    
     
     
         28 . A method in accordance with  claim 27  wherein said vanadium oxide incorporated support material oxidizes said heavy metal into an oxidized heavy metal species or heavy metal containing compound.  
     
     
         29 . A method in accordance with  claim 27  wherein said porous support material is selected from the group consisting of amorphous silica-alumina, a zeolite, a material comprising meta-kaolin, alumina, expanded perlite, and combinations thereof.  
     
     
         30 . A method in accordance with  claim 27  wherein said vanadium oxide compound comprises V 2 O 5 , a hydrate of V 2 O 5 , a peroxo complex of vanadium oxide, or mixtures thereof.  
     
     
         31 . A method in accordance with  claim 27  wherein said promoter is selected from the group consisting of lithium vanadate, lithium hydroxide, and mixtures thereof.  
     
     
         32 . A method in accordance with  claim 27  wherein said contacting step results in a pressure drop in said fluid stream of less than about 20 psia.  
     
     
         33 . A method in accordance with  claim 32  wherein said contacting step results in a pressure drop in said fluid stream of less than about 10 psia.  
     
     
         34 . A method in accordance with  claim 27  wherein said fluid stream has a temperature between about 50-400° F. during said contacting step.  
     
     
         35 . A method in accordance with  claim 27  wherein said fluid stream comprises at least one heavy metal or compound containing a heavy metal selected from the group consisting of arsenic, beryllium, lead, cadmium, chromium, nickel, zinc, mercury, and barium.  
     
     
         36 . A method in accordance with  claim 35  wherein said at least one heavy metal is mercury.  
     
     
         37 . A method in accordance with  claim 27  wherein said vanadium oxide incorporated support material comprises finely divided particles that are suspended in said fluid stream during said contacting step, pelletized particles placed in a fixed or fluidized bed, monoliths, or combinations thereof.  
     
     
         38 . A method in accordance with  claim 27  wherein said contacting step results in the sorption of at least about 80% by weight of the at least one heavy metal or heavy metal containing compound contained in said fluid stream.  
     
     
         39 . A method in accordance with  claim 27  wherein said vanadium oxide incorporated support material is capable of sorbing at least about 1 atom of said heavy metal per every 5 atoms of vanadium.  
     
     
         40 . A process for the removal of at least one heavy metal or heavy metal containing compound from a flue gas stream produced by the combustion of a hydrocarbon-containing fuel comprising the steps of: 
 (a) contacting said flue gas stream with a first sorbent material comprising a porous support having incorporated onto, into, or onto and into a vanadium oxide compound and an alkali metal promoter for sorbing at least a portion of said at least one heavy metal or heavy metal containing compound present in said flue gas stream; and    (b) contacting said flue gas with a second sorbent material different from said first sorbent material for sorbing at least a portion of said at least one heavy metal-containing compound not sorbed during step (a).    
     
     
         41 . A process as recited in  claim 40  wherein said second sorbent material comprises a material selected from the group consisting of porous zeolite materials, amorphous carbons, and combinations thereof.  
     
     
         42 . A process as recited in  claim 41  wherein said amorphous carbons are selected from the group consisting of activated charcoal, activated carbon, and combinations thereof.  
     
     
         43 . A process as recited in  claim 41  wherein said porous zeolite material comprises ZSM-5 zeolite.  
     
     
         44 . A process as recited in  claim 40  wherein said flue gas stream comprises at least one heavy metal or compound containing a heavy metal selected from the group consisting of arsenic, beryllium, lead, cadmium, chromium, nickel, zinc, mercury, and barium.  
     
     
         45 . A process as recited in  claim 44  wherein said at least one heavy metal is mercury.  
     
     
         46 . A process as recited in  claim 40  wherein said vanadium oxide compound comprises V 2 O 5 , a hydrate of V 2 O 5 , a peroxo complex of vanadium oxide, or combinations thereof.  
     
     
         47 . A process as recited in  claim 40  wherein step (a) results in a pressure drop in said flue gas stream of less than about 20 psia.  
     
     
         48 . A process as recited in  claim 40  wherein said flue gas stream has a temperature between about 50-400° F. during step (a).  
     
     
         49 . A process as recited in  claim 40  wherein said vanadium oxide incorporated support material comprises finely divided particles that are suspended in said flue gas stream during step (a), pelletized particles placed in a fixed or fluidized bed, monoliths, or combinations thereof.  
     
     
         50 . A process as recited in  claim 40  wherein step (a) results in the sorption of at least about 80% by weight of said at least one heavy metal or heavy metal containing compound contained in said flue gas stream.  
     
     
         51 . A process as recited in  claim 40  wherein step (b) results in the removal of at least about 80% by weight of said at least one heavy metal compound from the flue gas stream leaving step (a).  
     
     
         52 . A process as recited in  claim 40  wherein said alkali metal promoter is selected from the group consisting of lithium vanadate, lithium hydroxide, and mixtures thereof.  
     
     
         53 . A process as recited in  claim 40  wherein prior to step (a) said process includes removal of at least about 50% by weight of all NO x  and SO x  present in said flue gas.  
     
     
         54 . A process as recited in  claim 40  wherein said flue gas stream comprises less than about 400 ppm NO x  and less than about 800 ppm SO x  immediately prior to step (a).  
     
     
         55 . A process as recited in  claim 40  wherein said vanadium oxide incorporated support material oxidizes said heavy metal into an oxidized heavy metal species or heavy metal containing compound during step (a).