Controlling Slagging and/or Fouling in Furnaces Burning Biomass

Abstract

The description relates to controlling slagging and/or fouling in biomass burning furnaces. Combustion of such a biomass the fuel with air produces combustion gases containing sodium and/or potassium compositions, and the combustion gases are treated by contacting the combustion gases with kaolin and aluminum hydroxide. At least one of the kaolin and aluminum hydroxide can be introduced with the fuel, in a combustion chamber, with reburn fuel or with overfire air. For fuels also high in zinc and/or heavy metals, magnesium hydroxide is introduced into the combustion chamber or following heat exchangers.

1 . A process for controlling slagging and/or fouling in biomass burning combustors, comprising:
 a. combusting the fuel comprising biomass with air to produce combustion gases containing sodium and/or potassium compositions; and   b. contacting the combustion gases with kaolin and aluminum hydroxide.   
     
     
         2 . A process according to  claim 1 , wherein the introduction is into the combustor at a temperature within the range of from 1500 to 300° C. 
     
     
         3 . A process according to  claim 1 , wherein at least one of the kaolin and aluminum hydroxide are introduced with the fuel. 
     
     
         4 . A process according to  claim 1 , wherein at least one of the kaolin and aluminum hydroxide are introduced through ports in a combustion chamber where the fuel is combusted. 
     
     
         5 . A process according to any of  claims 1 - 3 , wherein at least one of the kaolin and aluminum hydroxide are introduced into the combustion chamber as an aqueous slurry. 
     
     
         6 . A process according to  claim 1 , wherein biomass fuel is introduced as a reburn fuel and at least one of the kaolin and aluminum hydroxide are introduced with the fuel. 
     
     
         7 . A process according to  claim 1 , wherein at least one of the kaolin and aluminum hydroxide are introduced with overfire air. 
     
     
         8 . A process according to  claim 1 , wherein the fuel is high in zinc and/or heavy metals and magnesium hydroxide is introduced into the combustion chamber or following heat exchangers.