Process for burning sulfur-containing fuels

Abstract

A process for burning a sulfur-containing fuel to produce a flue gas is disclosed. The process comprises introducing a sulfur-containing fuel into a combustion chamber, introducing an oxidant stream into the combustion chamber and mixing it with the sulfur-containing fuel to define a combustion zone, and introducing potassium carbonate into the combustion chamber. The sulfur-containing fuel is burned to produce the flue gas and potassium sulfate.

We claim:  
     
         1 . A process for burning a sulfur-containing fuel to produce a flue gas, the process comprising: 
 introducing a sulfur-containing fuel into a combustion chamber;    optionally oxygen-enriching an oxidant stream;    introducing the oxidant stream into the combustion chamber and mixing it with the sulfur-containing fuel to define a combustion zone;    introducing potassium carbonate into the combustion chamber; and    burning the sulfur-containing fuel to produce the flue gas and potassium sulfate.    
     
     
         2 . The process of  claim 1  wherein the total oxygen content of the oxidant entering the combustion chamber exceeds 21%.  
     
     
         3 . The process of  claim 2  wherein the potassium carbonate is introduced into the combustion chamber in the combustion zone.  
     
     
         4 . The process of  claim 2  wherein the potassium carbonate is introduced into the combustion chamber in an amount sufficient to exceed the stoichiometric requirement needed to react with the sulfur in the fuel by between 0% and 50%.  
     
     
         5 . The process of  claim 2  wherein at least half of the sulfur in the sulfur-containing fuel is converted to potassium sulfate.  
     
     
         6 . A process for burning a sulfur-containing fuel to produce a flue gas, the process comprising: 
 introducing a sulfur-containing fuel into a combustion chamber at a fuel inlet;    optionally oxygen-enriching at least one oxidant stream;    introducing a primary oxidant stream into the combustion chamber at a primary oxidant inlet positioned proximate to or coincident the fuel inlet and mixing it with the sulfur-containing fuel to define a first combustion zone;    introducing a secondary oxidant stream into the combustion chamber at a secondary oxidant inlet positioned so that the secondary oxidant enters the combustion chamber in the primary combustion zone;    introducing potassium carbonate into the combustion chamber; and    burning the sulfur-containing fuel to produce the flue gas and potassium sulfate.    
     
     
         7 . The process of  claim 6  wherein the total oxygen content of the oxidant entering the combustion chamber exceeds 21%.  
     
     
         8 . The process of  claim 7  wherein the total oxygen content of the primary oxidant exceeds 21%.  
     
     
         9 . The process of  claim 7  wherein the total oxygen content of the secondary oxidant exceeds 21%.  
     
     
         10 . The process of  claim 7  wherein at least a portion of the potassium carbonate is introduced into the combustion chamber in the primary combustion zone.  
     
     
         11 . The process of  claim 7  wherein the potassium carbonate is introduced into the combustion chamber in an amount sufficient to exceed the stoichiometric requirement needed to react with the sulfur in the fuel by between 0% and 50%.  
     
     
         12 . The process of  claim 7  wherein at least half of the sulfur in the sulfur-containing fuel is converted to potassium sulfate.  
     
     
         13 . A process for burning a sulfur-containing fuel to produce a flue gas, the process comprising: 
 introducing a sulfur-containing fuel into a combustion chamber at a fuel inlet;    optionally oxygen-enriching at least one oxidant stream;    introducing a primary oxidant stream into the combustion chamber at a primary oxidant inlet positioned proximate to or coincident the fuel inlet and mixing it with the sulfur-containing fuel to define a first combustion zone;    introducing a secondary oxidant stream into the combustion chamber at a secondary oxidant inlet positioned so that the secondary oxidant enters the combustion chamber in the primary combustion zone;    introducing a tertiary oxidant stream into the combustion chamber at a tertiary oxidant inlet positioned away from the primary oxidant inlet and away from the secondary oxidant inlet, the tertiary oxidant entering the combustion chamber to define a secondary combustion zone;    introducing potassium carbonate into the combustion chamber; and    burning the sulfur-containing fuel to produce the flue gas and potassium sulfate.    
     
     
         14 . The process of  claim 13  wherein the total oxygen content of the oxidant entering the combustion chamber exceeds 21%.  
     
     
         15 . The process of  claim 14  wherein the total oxygen content of the primary oxidant exceeds 21%.  
     
     
         16 . The process of  claim 14  wherein the total oxygen content of the secondary oxidant exceeds 21%.  
     
     
         17 . The process of  claim 14  wherein the total oxygen content of the tertiary oxidant exceeds 21%.  
     
     
         18 . The process of  claim 14  wherein at least a portion of the potassium carbonate is introduced into the combustion chamber in the primary combustion zone.  
     
     
         19 . The process of  claim 14  wherein at least a portion of the potassium carbonate is introduced into the combustion chamber in the secondary combustion zone.  
     
     
         20 . The process of  claim 14  wherein the potassium carbonate is introduced into the combustion chamber in an amount sufficient to exceed the stoichiometric requirement needed to react with the sulfur in the fuel by between 0% and 50%.  
     
     
         21 . The process of  claim 14  wherein at least half of the sulfur in the sulfur-containing fuel is converted to potassium sulfate.  
     
     
         22 . The process of  claim 14  wherein the potassium carbonate is introduced into the combustion chamber through the fuel inlet.  
     
     
         23 . The process of  claim 22  wherein the total oxygen content of the primary oxidant exceeds 21%.  
     
     
         24 . The process of  claim 23  wherein the total oxygen content of the secondary oxidant exceeds 21%.  
     
     
         25 . The process of  claim 24  wherein the total oxygen content of the tertiary oxidant exceeds 21%.  
     
     
         26 . The process of  claim 14  wherein the potassium carbonate is introduced into the combustion chamber through the tertiary air inlet.  
     
     
         27 . The process of  claim 26  wherein the total oxygen content of the primary oxidant exceeds 21%.  
     
     
         28 . The process of  claim 27  wherein the total oxygen content of the secondary oxidant exceeds 21%.  
     
     
         29 . The process of  claim 28  wherein the total oxygen content of the tertiary oxidant exceeds 21%.  
     
     
         30 . The process of  claim 29  wherein the potassium carbonate is introduced into the combustion chamber in an amount sufficient to exceed the stoichiometric requirement needed to react with the sulfur in the fuel by between 0% and 50%.  
     
     
         31 . The process of  claim 29  wherein at least half of the sulfur in the sulfur-containing fuel is converted to potassium sulfate.  
     
     
         32 . A process for burning a sulfur-containing fuel to produce a flue gas, the process comprising: 
 introducing a sulfur-containing fuel into a combustion chamber at a fuel inlet;    introducing a primary oxidant stream containing more than 21% oxygen into the combustion chamber at a primary oxidant inlet positioned proximate to or coincident the fuel inlet and mixing it with the sulfur-containing fuel to define a first combustion zone;    introducing a secondary oxidant stream containing more than 21% oxygen into the combustion chamber at a secondary oxidant inlet positioned so that the secondary oxidant enters the combustion chamber in the primary combustion zone;    introducing a tertiary oxidant stream containing more than 21% oxygen into the combustion chamber at a tertiary oxidant inlet positioned away from the primary oxidant inlet and away from the secondary oxidant inlet, the tertiary oxidant entering the combustion chamber to define a secondary combustion zone;    the total oxygen content of the oxidant entering the combustion chamber exceeding 21%;    introducing potassium carbonate into the combustion chamber through the tertiary air inlet in an amount sufficient to exceed the stoichiometric requirement needed to react with the sulfur in the fuel by between 0% and 50%; and    burning the sulfur-containing fuel to produce the flue gas and potassium sulfate; wherein at least half of the sulfur in the sulfur-containing fuel is converted to potassium sulfate.