Method of applying mercury reagent with coal

Abstract

A method of halogenating coal prior to combustion, wherein the coal is treated with a halogen prior to pulverization and the pulverized halogenated coal is delivered to a burner as fuel for a combustion process.

1 . A method of oxidizing mercury comprising: 
 treating a coal comprising mercury with a compound comprising a halogen;    pulverizing the treated coal;    feeding the pulverized treated coal to a pulverized coal burner;    utilizing the burner to combust the pulverized treated coal, wherein the compound oxidizes a substantial portion of the mercury contained in the coal during combustion; and    creating a flue gas comprising oxidized mercury.    
     
     
         2 . The method of  claim 1  wherein the combustion occurs between about 1050° C. and about 2000° C.  
     
     
         3 . The method of  claim 2 , wherein at least one mercury removing means removes a portion of the oxidized mercury from the flue gas downstream of the burner.  
     
     
         4 . The method of  claim 3 , wherein an aqueous solution comprising the compound is admixed with the mercury containing coal.  
     
     
         5 . The method of  claim 4 , wherein the aqueous solution is sprayed on the coal.  
     
     
         6 . The method of  claim 3 , wherein a solid comprising the compound is admixed with the mercury containing coal.  
     
     
         7 . The method of  claim 3 , wherein the compound is selected from the group consisting of sodium chloride, calcium chloride, and calcium bromide.  
     
     
         8 . The method of  claim 3 , wherein about 2 ppmw to about 1200 ppmw of the halogen is admixed with the mercury containing coal during treatment.  
     
     
         9 . The method of  claim 3 , wherein about 2 ppmw to about 30 ppmw of the halogen is admixed with the mercury containing coal during treatment.  
     
     
         10 . The method of  claim 3 , wherein about 300 ppmw to about 600 ppmw of the halogen is admixed with the mercury containing coal during treatment.  
     
     
         11 . The method of  claim 8 , further comprising the steps of monitoring the concentration of mercury in the flue gas, and regulating the rate of dispensing the compound to maintain substantial oxidation of the mercury during combustion.  
     
     
         12 . A method of producing oxidized mercury comprising: 
 providing a burner with a mercury containing coal;    utilizing the burner to combust the coal; and    combusting the coal in the presence of a compound comprising a halogen, wherein elemental mercury is oxidized during combustion.    
     
     
         13 . The method of  claim 12 , wherein the compound is added to the coal upstream of the burner.  
     
     
         14 . The method of  claim 13 , wherein a solution comprising the compound is sprayed on the coal.  
     
     
         15 . The method of  claim 13 , wherein a solid comprising the compound is admixed with the mercury containing coal.  
     
     
         16 . The method of  claim 14 , wherein the compound is selected from the group consisting of sodium chloride and calcium chloride.  
     
     
         17 . The method of  claim 15 , wherein the compound is selected from the group consisting of sodium chloride and calcium chloride.  
     
     
         18 . The method of  claim 17 , wherein the coal is pulverized prior to combustion and the compound is added to the coal prior to the coal pulverization.  
     
     
         19 . The method of  claim 12 , wherein the combustion take place between about 1050° C. and about 2000 C.  
     
     
         20 . The method of  claim 19 , wherein about 2 ppmw to about 1200 ppmw of the halogen is admixed with the mercury containing coal during treatment.  
     
     
         21 . The method of  claim 19 , wherein about 2 ppmw to about 30 ppmw of the halogen is admixed with the mercury containing coal during treatment.  
     
     
         22 . The method of  claim 18 , wherein about 300 ppmw to about 600 ppmw of the halogen is admixed with the mercury containing coal during treatment.