Mercury removal sorbent

Abstract

A sorbent composition comprising a vanadium compound and a ZrO 2 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 porous sorbent material comprising particles of a ZrO 2  support having incorporated onto, into, or onto and into at least one source of vanadium selected from the group consisting of vanadate ions, vanadium oxide, and combinations thereof, said material comprising at least about 5% by weight vanadium.  
     
     
         2 . A composition in accordance with  claim 1  wherein said ZrO 2  particles have an average particle size of between about 0.01-20 mm.  
     
     
         3 . A composition in accordance with  claim 1  wherein said material comprises between about 7-40% by weight vanadium.  
     
     
         4 . 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.  
     
     
         5 . A composition in accordance with  claim 1  wherein said ZrO 2  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 ZrO 2  support material has a surface area of at least about 75 m 2 /g.  
     
     
         7 . A composition in accordance with  claim 1  wherein said source of vanadate ions comprises NH 4 VO 3 .  
     
     
         8 . A method for forming a sorbent material comprising: 
 (a) incorporating into, onto, or into and onto a porous ZrO 2  support a mixture including a source of vanadate ions, and a solvent capable of solubilizing said source of vanadate ions;    (b) drying said vanadate incorporated ZrO 2  material; and    (c) calcining said dried vanadium incorporated ZrO 2  material.    
     
     
         9 . A method in accordance with  claim 8  wherein said source of vanadate ions comprises NH 4 VO 3 .  
     
     
         10 . A method in accordance with  claim 8  wherein step (a) includes impregnating said ZrO 2  support with said source of vanadate ions.  
     
     
         11 . A method in accordance with  claim 8  wherein step (a) includes dissolving said source of vanadate ions in said solvent followed by the addition of said oxidizing agent so as to maintain the vanadium present in said vanadate ions in a +5 oxidation state.  
     
     
         12 . A method in accordance with  claim 8  wherein said solvent is selected from the group consisting of oxalic acid, HNO 3 , HCl, and mixtures thereof.  
     
     
         13 . A method in accordance with  claim 8  wherein said mixture further includes an oxidizing agent.  
     
     
         14 . A method in accordance with  claim 13  wherein said oxidizing agent is different from said solvent and selected from the group consisting of H 2 SO 4 , HNO 3 , permanganate, ozone, H 2 O 2 , and mixtures thereof.  
     
     
         15 . A method in accordance with  claim 13  wherein said oxidizing agent is present in the vanadate ion containing mixture of step (a) at a level of about 0.01-25% by weight.  
     
     
         16 . A method in accordance with  claim 8  wherein step (c) includes heating said dried vanadium incorporated ZrO 2  material to a temperature of between about 392-1112° F.  
     
     
         17 . A method in accordance with  claim 16  wherein step (c) includes heating said dried vanadium incorporated ZrO 2  material to a temperature of between about 482-842° F.  
     
     
         18 . A method in accordance with  claim 8  wherein said calcined vanadium incorporated ZrO 2  material comprises V 2 O 5 , a hydrate of V 2 O 5 , a peroxo complex of vanadium oxide, or mixtures thereof.  
     
     
         19 . A method in accordance with  claim 8  wherein said calcined vanadium incorporated ZrO 2  material comprises at least about 5% by weight vanadium on an elemental basis.  
     
     
         20 . A method for forming a sorbent material comprising: 
 (a) preparing a mixture comprising a source of vanadate ions and a solvent capable of solubilizing said source of vanadate ions;    (b) adding a quantity of an oxidizing agent to said mixture;    (c) intimately mixing said mixture with a quantity of ZrO 2  particles;    (d) drying said intimate mixture thereby forming a vanadium incorporated ZrO 2  material; and    (e) calcining said vanadium incorporated ZrO 2  material.    
     
     
         21 . A method in accordance with  claim 20  wherein said solvent is selected from the group consisting of oxalic acid, HNO 3 , HCl, and mixtures thereof.  
     
     
         22 . A method in accordance with  claim 20  wherein said oxidizing agent is different from said solvent and selected from the group consisting of H 2 SO 4 , HNO 3 , permanganate, ozone, H 2 O 2 , and mixtures thereof.  
     
     
         23 . A method in accordance with  claim 20  wherein said source of vanadate ions comprises NH 4 VO 3 .  
     
     
         24 . A method in accordance with  claim 20  wherein said oxidizing agent is added to said mixture in step (b) so as to provide from about 0.01-25% ofthe total weight of the mixture.  
     
     
         25 . A method in accordance with  claim 20  wherein step (c) includes impregnating said ZrO 2  particles with said vanadate ions.  
     
     
         26 . A method in accordance with  claim 20  wherein step (d) includes heating said mixture to a temperature of at least about 212° F.  
     
     
         27 . A method in accordance with  claim 20  wherein step (b) includes the drop wise addition of said oxidizing agent to said mixture.  
     
     
         28 . A method in accordance with  claim 20  wherein said oxidizing agent is added in a sufficient quantity so as to maintain the vanadium present in said vanadate ions in a +5 oxidation state.  
     
     
         29 . A method in accordance with  claim 20  wherein step (e) includes heating said vanadium incorporated ZrO 2  material to a temperature of between about 392-1112° F.  
     
     
         30 . A method in accordance with  claim 29  wherein step (e) includes heating said vanadium incorporated ZrO 2  material to a temperature of between about 482-842° F.  
     
     
         31 . A method in accordance with  claim 20  wherein said vanadium incorporated ZrO 2  material comprises V 2 O 5 , a hydrate of V 2 O 5 , a peroxo complex of vanadium oxide, or mixtures thereof.  
     
     
         32 . A method in accordance with  claim 20  wherein said vanadium incorporated ZrO 2  material comprises at least about 5% by weight vanadium on an elemental basis.  
     
     
         33 . 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 ZrO 2  support material having incorporated onto, into, or onto and into a vanadium containing compound for sorption of at least a portion of said at least one heavy metal or heavy metal containing compound.    
     
     
         34 . A method in accordance with  claim 33  wherein said vanadium incorporated support material oxidizes said heavy metal into an oxidized heavy metal species or heavy metal containing compound.  
     
     
         35 . A method in accordance with  claim 33  wherein said vanadium compound comprises V 2 O 5 , a hydrate of V 2 O 5 , a peroxo complex of vanadium oxide, or mixtures thereof.  
     
     
         36 . A method in accordance with  claim 33  wherein said contacting step results in a pressure drop in said fluid stream of less than about 20 psia.  
     
     
         37 . A method in accordance with  claim 36  wherein said contacting step results in a pressure drop in said fluid stream of less than about 10 psia.  
     
     
         38 . A method in accordance with  claim 33  wherein said fluid stream has a temperature between about 50-400° F. during said contacting step.  
     
     
         39 . A method in accordance with  claim 33  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.  
     
     
         40 . A method in accordance with  claim 39  wherein said at least one heavy metal is mercury.  
     
     
         41 . A method in accordance with  claim 33  wherein said vanadium 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.  
     
     
         42 . A method in accordance with  claim 33  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.  
     
     
         43 . A method in accordance with  claim 33  wherein said vanadium incorporated support material is capable of sorbing at least about 1 atom of said heavy metal per every 5 atoms of vanadium.  
     
     
         44 . A method in accordance with  claim 33  wherein said vanadium incorporated material comprises at least about 5% by weight vanadium on an elemental basis.  
     
     
         45 . 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 ZrO 2  support material having incorporated onto, into, or onto and into a vanadium containing compound 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).    
     
     
         46 . A process as recited in  claim 45  wherein said vanadium incorporated support material oxidizes said heavy metal into an oxidized heavy metal species or heavy metal containing compound during step (a).  
     
     
         47 . A process as recited in  claim 45  wherein said second sorbent material comprises a material selected from the group consisting of porous zeolite materials, amorphous carbons, and combinations thereof.  
     
     
         48 . A process as recited in  claim 47  wherein said amorphous carbons are selected from the group consisting of activated charcoal, activated carbon, and combinations thereof.  
     
     
         49 . A process as recited in  claim 47  wherein said porous zeolite material comprises ZSM-5 zeolite.  
     
     
         50 . A process as recited in  claim 45  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.  
     
     
         51 . A process as recited in  claim 50  wherein said at least one heavy metal is mercury.  
     
     
         52 . A process as recited in  claim 45  wherein said vanadium compound comprises V 2 O 5 , a hydrate of V 2 O 5 , a peroxo complex of vanadium oxide, or mixtures thereof.  
     
     
         53 . A process as recited in  claim 45  wherein step (a) results in a pressure drop in said flue gas stream of less than about 20 psia.  
     
     
         54 . A process as recited in  claim 45  wherein said flue gas stream has a temperature between about 50-400° F. during step (a).  
     
     
         55 . A process as recited in  claim 45  wherein said vanadium 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.  
     
     
         56 . A process as recited in  claim 45  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.  
     
     
         57 . A process as recited in  claim 45  wherein step (b) results in the removal of at least about 80% by weight of said at least one heavy metal compound from said flue gas stream.  
     
     
         58 . A process as recited in  claim 45  wherein said vanadium incorporated material comprises at least about 5% by weight vanadium on an elemental basis.  
     
     
         59 . A process as recited in  claim 45  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.  
     
     
         60 . A process as recited in  claim 45  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).