Fuel compositions and its use

Abstract

A fuel composition containing a major amount of a fuel for an internal combustion engine and a minor amount of a fuel-compatible dendrimer containing from 4 to 64 terminal functional groups independently selected from amino, hydroxyl and carboxylate groups is disclosed. The use of such compositions as fuel in an internal combustion engine for controlling combustion chamber deposits is also disclosed.

1 . A fuel composition comprising a major amount of a fuel for an internal combustion engine and a minor amount of a fuel-compatible dendrimer containing from 4 to 64 terminal functional groups independently selected from amino, hydroxyl and carboxylate groups. 
   
   
       2 . The fuel composition of  claim 1  which further comprises a fuel-compatible oxygenate co-solvent selected from C 1  to C 14  alkanols and 2-ethylhexanoic acid. 
   
   
       3 . The fuel composition of  claim 1  wherein the dendrimer is at least one fuel-compatible dendrimer independently selected from DAB-Am, PAMAM and PAMAM-OH dendrimers. 
   
   
       4 . The fuel composition of  claim 1  wherein the dendrimer contains from 4 to 32 terminal functional groups. 
   
   
       5 . The fuel composition of  claim 1  wherein the dendrimer is present in a concentration in the range from 5 ppmw to 500 ppmw based on total composition. 
   
   
       6 . The fuel composition of  claim 5  wherein the dendrimer is present in a concentration in the range from 10 ppmw to 200 ppmw based on total composition. 
   
   
       7 . The fuel composition of  claim 1  further comprises a nitrogen-containing detergent having a hydrocarbyl group having a number average molecular weight (Mn) in the range of 750 to 6000, in a concentration in the range of 25 to 2500 ppmw based on total composition. 
   
   
       8 . The fuel composition of  claim 1  wherein the fuel for an internal combustion engine is gasoline. 
   
   
       9 . The fuel composition of  claim 5  wherein the dendrimer contains from 4 to 32 terminal functional groups. 
   
   
       10 . The fuel composition of  claim 9  wherein the dendrimer is at least one fuel-compatible dendrimer independently selected from DAB-Am, PAMAM dn PAMAM-OH dendrimers. 
   
   
       11 . A method of operating an internal combustion engine which comprises introducing into the combustion chambers of said engine a fuel composition of  claim 1 . 
   
   
       12 . A method of operating an internal combustion engine which comprises introducing into the combustion chambers of said engine a fuel composition of  claim 2 . 
   
   
       13 . A method of operating an internal combustion engine which comprises introducing into the combustion chambers of said engine a fuel composition of  claim 3 . 
   
   
       14 . A method of operating an internal combustion engine which comprises introducing into the combustion chambers of said engine a fuel composition of  claim 4 . 
   
   
       15 . A method of operating an internal combustion engine which comprises introducing into the combustion chambers of said engine a fuel composition of  claim 9 .