Fuel composition comprising detergent and quaternary ammonium salt additive

Abstract

A method of reducing deposits in a diesel engine, the method comprising combusting in the engine a diesel fuel composition comprising a detergent additive which is not a quaternary ammonium salt or a Mannich reaction product; and a quaternary ammonium salt additive comprising the reaction product of nitrogen containing species having at least one tertiary amine group and a quaternizing agent; wherein the nitrogen containing species is selected from: (i) the reaction product of a hydrocarbyl-substituted acylating agent and a compound comprising at least one tertiary amine group and a primary amine, secondary amine or alcohol group; (ii) a Mannich reaction product comprising a tertiary amine group; and (iii) a polyalkylene substituted amine having at least one tertiary amine group.

1 . A method of reducing deposits in a diesel engine, the method comprising combusting in the engine a diesel fuel composition comprising a detergent additive which is not a quaternary ammonium salt or a Mannich reaction product; and a quaternary ammonium salt additive comprising the reaction product of nitrogen containing species having at least one tertiary amine group and a quaternizing agent; wherein the nitrogen containing species is selected from:
 (i) the reaction product of a hydrocarbyl-substituted acylating agent and a compound comprising at least one tertiary amine group and a primary amine, secondary amine or alcohol group;   (ii) a Mannich reaction product comprising a tertiary amine group; and   (iii) a polyalkylene substituted amine having at least one tertiary amine group; wherein the detergent additive is the reaction product of a carboxylic acid derived acylating agent and an amine; and wherein the method provides control of deposits within the injector body of a modern diesel engine having a high pressure fuel system to prevent injector sticking.   
     
     
         2 . A method according to  claim 1  in which the formation of deposits is inhibited or prevented to provide a keep clean performance. 
     
     
         3 . A method according to  claim 1  in which the existing deposits are removed to provide a clean up performance. 
     
     
         4 . A method according to  claim 1  wherein the quaternizing agent is selected from the group consisting of dialkyl sulphates; an ester of a carboxylic acid; alkyl halides; benzyl halides; hydrocarbyl substituted carbonates; and hydrocarbyl epoxides, optionally in combination with an acid or mixtures thereof. 
     
     
         5 . A method according to  claim 1  wherein the nitrogen containing species comprises a compound formed by the reaction of a hydrocarbyl-substituted acylating agent and an amine of formula (I) or (II): 
       
         
           
           
               
               
           
         
         wherein R 2  and R 3  are the same or different alkyl groups having from 1 to 22 carbon atoms; X is an alkylene group having from 1 to 20 carbon atoms; n is from 0 to 20; m is from 1 to 5; and R 4  is hydrogen or a C 1  to 5 C 22  alkyl group. 
       
     
     
         6 . A method according to  claim 1  wherein the quaternizing agent comprises a compound of formula (II): 
       
         
           
           
               
               
           
         
         wherein R is a substituted alkyl, alkenyl, aryl or alkylaryl group; and R 1  is a C 1  to C 22  alkyl, aryl or alkylaryl group. 
       
     
     
         7 . A method according to  claim 1  wherein the detergent additive is made by reacting a poly(isobutene)-substituted succinic acid-derived acylating agent wherein the poly(isobutene) substituent has between about 12 to about 200 carbon atoms with a mixture of ethylene polyamines having 3 to about 9 amino nitrogen atoms per ethylene polyamine and about 1 to about 8 ethylene groups. 
     
     
         8 . A method according to  claim 1  wherein the fuel composition comprises a further detergent additive which is the reaction product between a hydrocarbyl-substituted succinic acid or anhydride and hydrazine. 
     
     
         9 . A method according to  claim 1  wherein the fuel composition comprises a further detergent additive which is the di-n-butylamine or tri-n-butylamine salt of a fatty acid of the formula [R′(COOH)x] y′ , where each R′ is a independently a hydrocarbon group of between 2 and 45 carbon atoms, and x is an integer between 1 and 4. 
     
     
         10 . A method according to  claim 1  wherein the fuel composition comprises a further detergent additive which is the reaction product of an amine compound having the formula: 
       
         
           
           
               
               
           
         
         and a hydrocarbyl carbonyl compound of the formula: 
       
       
         
           
           
               
               
           
         
         wherein R is selected from the group consisting of a hydrogen and a hydrocarbyl group containing from about 1 to about 15 carbon atoms; R 1  is selected from the group consisting of hydrogen and a hydrocarbyl group containing from about 1 to about 20 carbon atoms; and R 2  is a hydrocarbyl group having a number average molecular weight ranging from about 100 to about 5000. 
       
     
     
         11 . A method according to  claim 1  wherein the fuel composition comprises a further detergent additive which comprises at least one compound of formula (IV) and/or formula (V): 
       
         
           
           
               
               
           
         
         wherein each Ar independently represents an aromatic moiety having 0 to 3 substituents selected from the group consisting of alkyl, alkoxy, alkoxyalkyl, aryloxy, aryloxyalkyl, hydroxy, hydroxyalkyl, halo and combinations thereof; 
         each L is independently a linking moiety comprising a carbon-carbon single bond or a linking group; 
         each Y is independently —OR 1″  or a moiety of the formula H(O(CR 1   2 ) n ) y X—, wherein X is selected from the group consisting of (CR 1   2 ) 2 , O and S: R 1  and R 1′  are each independently selected from H, C 1  to C 6  alkyl and aryl; R 1″  is selected from C 1  to C 100  alkyl and aryl; z is 1 to 10; n is 0 to 10 when X is (CR 1   2 ) 2 , and 2 to 10 when X is O or S; and y is 1 to 30; 
         each a is independently 0 to 3, with the proviso that at least one Ar moiety bears at least one group Y; 
         and m is 1 to 100; 
         wherein each Ar′ independently represents an aromatic moiety having 0 to 3 substituents selected from the group consisting of alkyl, alkoxy, alkoxyalkyl, hydroxy, hydroxyalkyl, acyloxy, acyloxyalkyl, acyloxyalkoxy, aryloxy, aryloxyalkyl, aryloxyalkoxy, halo and combinations thereof; 
         each L′ is independently a linking moiety comprising a carbon-carbon single bond or linking group; 
         each Y′ is independently a moiety of the formula ZO— or Z(O(CR 2   2 ) n ′) y′ X′—wherein X′ is selected from the group consisting of (CR 2′   2 ) z′ , O and S; R 2  and R 2′  are each independently selected from H, C 1  to C 6  alkyl and aryl z′ is 1 to 10; n′ is 0 to 10 when X′ is (CR 2′   2 ) z , and 2 to 10 when X′ is O or S; y is 1 to 30; Z is H, an acyl group, a polyacyl group, a lactone ester group, an acid ester group, an alkyl group or an aryl group; 
         each a′ is independently 0 to 3, with the proviso that at least one Ar′ moiety bears at least one group Y′ in which Z is not H; and m′ is 1 to 100. 
       
     
     
         12 . A diesel fuel composition as defined in  claim 1 . 
     
     
         13 . A method according to  claim 10 , wherein R 2  is a hydrocarbyl group having a number average molecular weight ranging from about 200 to about 3000.