Method for combustion of pulverized coal with reduced emissions

Abstract

Fuel compositions containing (a) pulverized coal; and (b) an oxygenate selected from glycerol, glycerol derivatives, propylene glycol, propylene glycol derivatives, ethylene glycol, ethylene glycol derivatives, fatty acid alkyl esters, fatty alcohols, and mixtures thereof. Methods of reducing the NOx emissions generated from the burning of pulverized coal in a heat-producing unit, wherein the method comprises the steps of: (a) introducing pulverized coal into a combustion chamber of the heat-producing unit; and (b) co-firing the pulverized coal with an oxygenate source selected from glycerol, glycerol derivatives, propylene glycol, propylene glycol derivatives, ethylene glycol, ethylene glycol derivatives, fatty acid alkyl esters, fatty alcohols, and mixtures thereof, where the combustion of the oxygenate source generates at least 2.5 %, on a heat input basis, of the total heat generated by the co-firing.

1 . A fuel composition providing reduced emissions of NOx when combusted, said composition comprising: 
 a) pulverized coal; and    b) an oxygenate source selected from the group consisting of, propylene glycol, propylene glycol derivatives, ethylene glycol, ethylene glycol derivatives, fatty acid alkyl esters, fatty alcohols, and mixtures thereof.    
   
   
       2 . A fuel composition according to  claim 1  wherein the ratio of oxygenate source to coal is from about 2.5% to about 50%.  
   
   
       3 . A fuel composition according to  claim 2  wherein co-firing of the composition in a heat-producing unit generates a heat input and wherein from about 2.5% to about 40% of the heat input is generated by the combustion of the oxygenate source.  
   
   
       4 . A fuel composition according to  claim 3  wherein from about 10% to about 20% of the heat input is generated by the combustion of the oxygenate source.  
   
   
       5 . A fuel composition according to  claim 1  wherein the fuel composition further comprises a secondary oxygenate source selected from the group consisting of oils, fats, fatty acids, and mixtures thereof.  
   
   
       6 . A fuel composition according to  claim 1  wherein the oxygenate source is selected from the group consisting of propylene glycol, propylene glycol derivatives and mixtures thereof.  
   
   
       7 . A fuel composition according to  claim 1  wherein the oxygenate source is selected from the group consisting of ethylene glycol, ethylene glycol derivatives and mixtures thereof.  
   
   
       8 . A fuel composition according to  claim 1  wherein the oxygenate is selected from the group consisting of methyl esters of fatty acids, and mixtures thereof.