Method for reducing emission of pollutants from an internal combustion engine, and fuel emulsion comprising water and a liquid hydrocarbon

Abstract

A fuel emulsion has a liquid hydrocarbon fuel, water, at least one emulsifier and at least one oxygen-containing water soluble organic compound. In the fuel emulsion, water is present in an amount not greater than 15% by weight, and the emulsifier is selected from a product obtained by reacting (a1) a polyolefin oligomer functionalized with at least one group deriving from a dicarboxylic acid, or a derivative thereof, with (a2) a polyoxyalkylene comprising linear oxyalkylene units. In the fuel emulsion, the oxygen-containing water soluble organic compound is present in a predetermined amount so as to obtain an amount of water soluble organic oxygen of from 0.1 to 5% by weight. A considerable reduction of particulate emissions is obtained by using this fuel emulsion while maintaining or even further reducing the NOx level which is already reduced by the engine itself.

1 - 38 . (canceled) 
     
     
         39 . A fuel emulsion comprising:
 a liquid hydrocarbon fuel,   water,   at least one emulsifier, and   at least one oxygen-containing water soluble organic compound as additive for reducing emission of pollutants, wherein   water is present in an amount not greater than 15% by weight,   the at least one emulsifier is selected from a product obtained by reacting (a1) a polyolefin oligomer functionalized with at least one group deriving from a dicarboxylic acid, or a derivative thereof, with (a2) a polyoxyalkylene comprising linear oxyalkylene units, said polyoxyalkylene being linked to a long-chain alkyl group optionally containing one or more ethylenic unsaturation,   the at least one oxygen-containing water soluble organic compound is present in a predetermined amount so as to obtain an amount of water soluble organic oxygen of from 0.1 to 5% by weight, and   the at least one oxygen-containing water soluble organic compound is selected from mono-, di-, and tri-alkylene glycols, and mixtures thereof.   
     
     
         40 . The fuel emulsion according to  claim 39 , wherein the water is present in an amount of 2 to 12% by weight. 
     
     
         41 . The fuel emulsion according to  claim 40 , wherein the water is present in an amount of 2.5 to 10% by weight. 
     
     
         42 . The fuel emulsion according to  claim 41 , wherein the water is present in an amount of 3 to 8% by weight. 
     
     
         43 . The fuel emulsion according to  claim 39 , wherein the oxygen-containing water soluble organic compound is present in a predetermined amount so as to obtain an amount of water soluble organic oxygen of 0.3 to 5% by weight. 
     
     
         44 . The fuel emulsion according to  claim 43 , wherein the oxygen-containing water soluble organic compound is present in a predetermined amount so as to obtain an amount of water soluble organic oxygen of 0.5 to 2.5% by weight. 
     
     
         45 . The fuel emulsion according to  claim 44 , wherein the oxygen-containing water soluble organic compound is present in a predetermined amount so as to obtain an amount of water soluble organic oxygen of 0.8 to 2% by weight. 
     
     
         46 . The fuel emulsion according to  claim 39 , wherein the oxygen-containing water soluble organic compound has a solubility in water at 20° C. of at least 5% by weight. 
     
     
         47 . The fuel emulsion according to  claim 46 , wherein the oxygen-containing water soluble organic compound has a solubility in water at 20° C. of at least 8% by weight. 
     
     
         48 . The fuel emulsion according to  claim 39 , wherein the emulsifier has a hydrophilic-lipophilic balance (HLB) of 2 to 10. 
     
     
         49 . The fuel emulsion according to  claim 48 , wherein the emulsifier has a hydrophilic-lipophilic balance (HLB) of 3 to 8. 
     
     
         50 . The fuel emulsion according to  claim 39 , wherein the emulsifier is present in an amount of 0.1 to 10% by weight. 
     
     
         51 . The fuel emulsion according to  claim 50 , wherein the emulsifier is present in an amount of 0.5 to 5% by weight.