Filter system

Abstract

The present invention is an improved filtration system, filtering method and unique chemical composition for capturing mercury and other pollutants in flue gases generated by process gas streams. The improved filtration system may take various forms depending on the type of filter system most desired for a particular application; however, the filter system includes at least a filter element or elements and an adsorbent component having a composition suitable for capturing mercury on the downstream side of the filter element.

1 . A composition comprising 
 (a) an air-permeable high surface area support having thereon    (b) a binding agent comprising at least one binding compound having a component selected from the group consisting of an anion of a halide, an anion of a thiocyanate, an anion of a sulfide, an anion of a polysulfide, an anion of selenium, an oxyanion of selenium, an anion of tellurium, an oxyanion of tellurium, an anion of phosphorus, and an oxyanion of phosphorus; and    (c) a promoter comprising at least one promoter compound having a component selected from a multivalent metallic cation and a multivalent metalloid cation, said promoter compound having a standard aqueous reduction potential Emf value at 25° C. less than −0.56 volts,    wherein said composition is capable of chemical reaction with elemental and oxidized mercury to bind said elemental and oxidized mercury.    
     
     
         2 . A composition comprising activated carbon having thereon potassium iodide and zinc acetate.  
     
     
         3 . A composition comprising activated carbon having thereon the reaction product of potassium iodide, zinc acetate and mercury.  
     
     
         4 . An article comprising: 
 an air permeable high surface area support material; and    a coating on at least a portion of said high surface area support material comprising (1) a binding agent comprising at least one binding compound having a component selected from the group consisting of an anion of a halide, an anion of a thiocyanate, an anion of a sulfide, an anion of a polysulfide, an anion of selenium, an oxyanion of selenium, an anion of tellurium, an oxyanion of tellurium, an anion of phosphorus, and an oxyanion of phosphorus; and (2) a promoter comprising at least one promoter compound having a component selected from a multivalent metallic cation and a multivalent metalloid cation, said promoter compound having a standard aqueous reduction potential Emf value at 25° C. less than −0.56 volts.    
     
     
         5 . The article of  claim 4 , wherein said porous support material comprises activated carbon.  
     
     
         6 . The article of  claim 4 , wherein said article is in the form of a tube.  
     
     
         7 . The article of  claim 4 , wherein said article is in the form of a flat sheet.  
     
     
         8 . The article of  claim 4 , wherein said article is pleated.  
     
     
         9 . The article of  claim 4 , wherein said article is in the form of a canister.  
     
     
         10 . The article of  claim 4 , wherein said porous support material comprises an activated carbon fiber felt.  
     
     
         11 . The article of  claim 4 , wherein said article is rigid.  
     
     
         12 . The article of  claim 4 , wherein said article is flexible.  
     
     
         13 . The article of  claim 4 , wherein said air permeable high surface area support material comprises a fluoropolymer material filled with a high surface area component.  
     
     
         14 . An article comprising a rigid tube of activated carbon having a coating on at least a portion thereof, said coating comprising potassium iodide and zinc acetate.  
     
     
         15 . The article of  claim 4 , wherein said high surface area support material comprises at least one of woven and nonwoven fibers selected from the group consisting of glass and mineral, said fibers having thereon a coating of a high surface area component.  
     
     
         16 . The article of  claim 15 , wherein said high surface area component comprises activated carbon.  
     
     
         17 . The article of  claim 1  in the form of an insert for a filter element.  
     
     
         18 . An article comprising: 
 an air permeable high surface area support material comprising activated carbon; and    a coating on said support material comprising a binding agent comprising potassium iodide and a promoter comprising zinc acetate.