Fuel composition containing detergent combination and methods thereof

Abstract

A fuel composition comprises a hydrocarbon fuel, a combination of nitrogen-containing detergents that includes a hydrocarbyl-substituted polyamine and a Mannich reaction product, and optionally a fluidizer. Methods of operating and of controlling deposits in an internal combustion engine involve fueling the engine with the fuel composition which results in unexpectedly effective and efficient control of deposits in the fuel induction system.

What is claimed is:  
     
         1 . A fuel composition useful for a spark or a compression ignition internal combustion engine, comprising: 
 a hydrocarbon fuel;    a combination of nitrogen-containing detergents comprising a hydrocarbyl-substituted polyamine and a Mannich reaction product of an alkyl-substituted hydroxyaromatic compound, an aldehyde, and a polyamine having at least one reactive N—H group; and    optionally a fluidizer comprising a polyether, a polyetheramine, or mixtures thereof;    wherein the weight ratio of the hydrocarbyl-substituted polyamine to the Mannich reaction product is about 0.2:1 to 1:0.2; each of the nitrogen-containing detergents is present at about 20-100 ppm by weight; and the weight ratio of the fluidizer to the combination of nitrogen-containing detergents is less than 0.5.    
     
     
         2 . The fuel composition of  claim 1  wherein the weight ratio of the hydrocarbyl-substituted polyamine to the Mannich reaction product is about 0.5:1 to 1:0.5.  
     
     
         3 . The fuel composition of  claim 1  wherein each of the nitrogen-containing detergents is present at about 22-80 ppm by weight.  
     
     
         4 . The fuel composition of  claim 1  wherein the weight ratio of the fluidizer to the combination of nitrogen-containing detergents is less than 0.3.  
     
     
         5 . The fuel composition of  claim 1  wherein the combination of nitrogen-containing detergents is present at or greater than about 60 ppm by weight.  
     
     
         6 . The fuel composition of  claim 1  wherein the hydrocarbyl substituent of the hydrocarbyl-substituted polyamine is derived from a polyolefin having a number average molecular weight of about 900-1500.  
     
     
         7 . The fuel composition of  claim 6  wherein the polyolefin is a polyisobutylene.  
     
     
         8 . The composition of  claim 6  wherein the hydrocarbyl-substituted polyamine is derived from the group consisting of ethylenediamine, diethylenetriamine, N,N-dimethyl-1,3-propanediamine, 2-(2-aminoethylamino)ethanol, and mixtures thereof.  
     
     
         9 . The fuel composition of  claim 1  wherein the hydroxyaromatic portion of said alkyl-substituted hydroxyaromatic compound comprises phenol, ortho-cresol, or mixtures thereof.  
     
     
         10 . The fuel composition of  claim 9  wherein the alkyl substituent of the alkyl-substituted hydroxyaromatic compound is derived from a polyolefin having a number average molecular weight of about 400-1500.  
     
     
         11 . The fuel composition of  claim 10  wherein the polyolefin is a polyisobutylene having at least 70% of the olefinic double bonds as vinylidene double bonds.  
     
     
         12 . The fuel composition of  claim 11  wherein the aldehyde is formaldehyde; and the Mannich reaction product is derived from the group consisting of ethylenediamine, propylenediamine, diethylenetriamine, N,N′-dimethylethylenediamine, N,N,N′-trimethylethylenediamine, N,N-dimethylethylenediamine, N,N-dimethylpropylenediamine, N,N′-dimethylpropylenediamine, 2-(2-aminoethylamino)ethanol, and mixtures thereof.  
     
     
         13 . The fuel composition of  claim 1  wherein the hydrocarbon fuel is a gasoline or a diesel fuel; and wherein the gasoline or diesel fuel optionally contains an oxygenate comprising methanol, ethanol, methyl tert-butyl ether, ethyl tert-butyl ether, methyl tert-amyl ether, or mixtures thereof.  
     
     
         14 . A method of operating an internal combustion engine, comprising fueling the engine with the fuel composition of  claim 13 .  
     
     
         15 . A method of controlling deposits in an internal combustion engine, comprising fueling the engine with the fuel composition of  claim 13.