Gasoline solutions containing a scavenger for the oxides of nitrogen

Abstract

The scavenger for oxides of nitrogen to be used in gasoline solutions is ethyl carbamate also called urethane. This compound is not soluble in 100% gasoline but it is soluble in solutions of 90/10 v/v gasoline/ethanol, 90/10 v/v gasoline/methanol and 90/10 v/v gasoline/mixture of ethanol and methanol. A small percentage of water such as 5% by volume can be present in the alcohol so therefore, 190 proof ethanol can be used. The solutions of ethyl carbamate in the above blends of gasoline and alcohol are clear and stable both at room temperature and at sub-freezing temperatures such as −15° C. The concept of this invention is that the ethyl carbamate must first hydrolyze to ethyl alcohol and carbamic acid in the internal combustion engine due to the presence of water vapor. The ethyl alcohol produced combusts and the carbamic acid decomposes to carbon dioxide and ammonia. The ammonia reduces the NOx that had been generated giving nitrogen and water vapor. The late release of ammonia in the exhaust gases when most of the oxygen has been depleted in the combustion of the fuel is the key to the concept of this invention.

I claim:  
     
         1 . A composition of matter consisting of the ethyl carbamate NOx scavenger dissolved in unleaded gasoline containing an aliphatic alcohol made by blending at low shear a solution of ethyl carbamate in the alcohol with unleaded gasoline resulting in a clear, low viscosity solution that is stable and remains clear without any solid phase precipitaion over a wide range of temperatures including sub-freezing temperatures such as −15° C.  
     
     
         2 .  Claim 1  in which the aliphatic alcohol is 95% denatured ethyl alcohol.  
     
     
         3 .  Claim 1  in which the aliphatic alcohol is methanol.  
     
     
         4 .  Claim 1  in which the aliphatic alcohol consists of a solution blend of 95% denatured ethyl alcohol and methanol.  
     
     
         5 .  Claim 1  in which the aliphatic alcohol consists of a solution blend of 95% denatured ethyl alcohol and octanol-1.  
     
     
         6 . Claims  1  and  2  in which the composition is v/v 90/10 unleaded gasoline/95% denatured ethyl alcohol containing 0.1 to 4.0% ethyl carbamate by weight.  
     
     
         7 . Claims  1  and  2  in which the composition is v/v 85/15 unleaded gasoline/95% denatured ethyl alcohol containing 0.1 to 5.0% ethyl carbamate by weight.  
     
     
         8 . Claims  1  and  3  in which the composition is v/v 90/10 unleaded gasoline/methanol containing 0.1 to 5.2% ethyl carbamate by weight.  
     
     
         9 . Claims  1  and  3  in which the composition is v/v 85/15 unleaded gasoline/methanol containing 0.1 to 6.1% ethyl carbamate by weight.  
     
     
         10 . Claims  1  and  4  in which the composition is v/v 90/5/5 unleaded gasoline/95% denatured ethyl alcohol/methanol containing 0.1 to 4.6% ethyl carbamate by weight.  
     
     
         11 . Claims  1  and  5  in which the composition is v/v88.2/9.8/2.0 unleaded gasoline/95% denatured ethyl alcohol/octanol-1 containing from 0.1 to 6.3% ethyl carbamate.