Method for Reducing NOx Emissions from Ethanol-Blended Diesel Fuels

Abstract

A method to reduce NO x , emissions from diesel fuel alcohol microemulsions (E-diesel) is taught. Ethanol is stripped from the microemulsion and entered into the exhaust gasses upstream of the reducing catalyst. The method allows diesel engines to meet new, lower emission standards without having to carry separate fuel and reductant tanks.

1 . A method to reduce NO x , emissions from the exhaust of diesel engines by use of E-diesel fuel and a selective catalytic reducing converter comprising the steps: 
 distilling out a portion of the ethanol in the E-diesel under reduced pressure,    injecting the distilled ethanol into exhaust gasses from the engine upstream of said selective catalytic reducing converter,    controlling said ethanol injection using at least one engine parameter selected from the group consisting of intake air flow, fuel mixture richness, engine operating temperature and NO x  sensor output.    
   
   
       2 . A method according to  claim 1  wherein the distillation process is performed periodically.  
   
   
       3 . A method according to  claim 1  wherein the distillation is continuous.  
   
   
       4 . A method according to  claim 1  wherein the distillation is performed under a vacuum.  
   
   
       5 . A method according to  claim 1  wherein the distillation is performed at atmospheric pressure.  
   
   
       6 . A method according to  claim 1  wherein the amount of injected ethanol corresponds to the amount of NO x  in the exhaust.