METHODS AND USES FOR CONTROLLING SLUDGE IN ENGINES

Abstract

The use as a sludge controlling additive in a fuel composition for a spark-ignition internal combustion engine or a compression-ignition gasoline internal combustion engine of a combination of: a. a hydrocarbyl-substituted aromatic compound; and b. a polyalkylene amine. The fuel composition may also be used for maintaining oil pathways and/or lubrication in an engine.

Claims

1-15. (canceled)

16. A method of controlling sludge formation in a spark-ignition internal combustion engine or a compression-ignition gasoline internal combustion engine which method comprises supplying to the engine a fuel composition which comprises a combination of: a. a hydrocarbyl-substituted aromatic compound; and b. a polyalkylene amine, the hydrocarbyl-substituted aromatic compound and the polyalkylene amine being present in the fuel composition in an amount such that substantially less sludge is formed when the fuel composition is combusted in the engine than when the same fuel composition without the combination of the hydrocarbyl-substituted aromatic compound and the polyalkyleneamine is combusted in the engine.

17. The method of claim 16, wherein the hydrocarbyl-substituted aromatic compound is a Mannich Base additive.

18. The method of claim 16, wherein the polyalkylene amine is a polyisobutylene amine.

19. The method of claim 16, wherein the hydrocarbyl-substituted aromatic compound is present in the fuel composition at a concentration of actives of from about 20 ppm to about 300 ppm.

20. The method of claim 16, wherein the hydrocarbyl substituent of the aromatic compound exhibits a number average molecular weight of from about 700 to about 1500.

21. The method of claim 16, wherein the hydrocarbyl substituent of the aromatic compound is or comprises polyisobutylene.

22. The method of claim 16, wherein the polyalkylene amine is present in the fuel composition at a concentration of actives of from about 50 ppm to about 500 ppm.

23. The method of claim 16, wherein the polyalkylene amine contains a polyalkylene group that exhibits a number average molecular weight of from about 700 to about 1500.

24. The method of claim 16, wherein the weight ratio of actives of the polyalkylene amine: the hydrocarbyl-substituted aromatic compound in the fuel composition is in the range of from about 5:1 to about 1:5.

25. The method of claim 16, wherein the engine is a spark-ignition internal combustion engine.

26. The method of claim 16, wherein the engine is a compression-ignition gasoline internal combustion engine.

27. The method of claim 16, wherein the at least one polyalkylene amine is present in the fuel composition at a concentration of actives of from 100 ppm to 500 ppm.

28. The method of claim 16, wherein the at least one polyalkylene amine is present in the fuel composition at a concentration of actives of from 160 ppm to 500 ppm.

29. The method of claim 16, wherein the at least one hydrocarbyl-substituted aromatic compound is present in the fuel composition at a concentration of actives of from 70 ppm to 200 ppm.

30. The method of claim 16, wherein the at least one hydrocarbyl-substituted aromatic compound is present in the fuel composition at a concentration of actives of from 70 ppm to 200 ppm; and the at least one polyalkylene amine is present in the fuel composition at a concentration of actives of from 160 ppm to 500 ppm.

31. The method of claim 16, wherein the hydrocarbyl-substituted aromatic compound is a Mannich Base additive, and the polyalkylene amine is a polyisobutylene amine.

32. A method of reducing the sludge forming tendency of a fuel composition for use in a spark-ignition internal combustion engine or a compression-ignition gasoline internal combustion engine which method comprises incorporating into the fuel composition in one or more steps: a. a hydrocarbyl-substituted aromatic compound; and b. a polyalkylene amine to produce a fuel composition which comprises said additives in combination and which on use in said engine produces less sludge than the sludge formed when using in said engine the fuel composition without said combination of additives.

33. The method of claim 32, wherein the hydrocarbyl-substituted aromatic compound is a Mannich Base additive and the polyalkylene amine is a polyisobutylene amine.

34. The method of claim 32, wherein the hydrocarbyl-substituted aromatic compound is present in the fuel composition at a concentration of actives of from about 20 ppm to about 300 ppm, and the polyalkylene amine is present in the fuel composition at a concentration of actives of from about 50 ppm to about 500 ppm.

35. A method of maintaining oil pathways and/or lubrication in a spark-ignition internal combustion engine or a compression-ignition gasoline internal combustion engine which method comprises supplying to the engine a fuel composition which comprises a combination of: a. a hydrocarbyl-substituted aromatic compound; and b. a polyalkylene amine.

Description

EXAMPLE 1

Combination of Mannich Base Additive and Polyisobutylene Amine

[0190] The engine sludge and rocker cover sludge control performance of a fuel containing a combination of Mannich Base additive and PIBA additive was assessed. The amount of Mannich Base additive and PIBA used in the experiment was selected to give a typical port fuel injection valve keep-clean performance which was comparable to that of the fuel composition used for Experiment A.

[0191] The engine sludge and rocker cover sludge control performance is shown in graph form in FIG. 1 as relative % sludge control performance (relative to a base fuel reference).

[0192] The data generated in Experiment A and Example 1 are shown in Table 2.

TABLE-US-00002 TABLE 2 Keep-clean Treat rate Engine sludge control performance (arbitrary performance (% relative (arbitrary units mass to base fuel reference)* units) per volume) Engine Rocker cover Experiment A 10.0 20.0 113% 100% Example 1 9.9 18.9 115% 103% *a high number indicates better control performance

[0193] The data shown in Table 2 and in FIG. 1 show that the fuel composition comprising Mannich Base additive in combination with a polyisobutylene amine exhibits beneficial sludge control in a spark-ignition internal combustion engine. In particular, the data show that the fuel composition comprising a Mannich Base additive in combination with a polyisobutylene amine exhibits greater sludge control in a spark-ignition internal combustion engine than an un-additised fuel and a fuel containing only polyisobutylene amine. The comparison with the fuel containing polyisobutylene amine is made for example at concentrations of additives providing comparable detergency performance, when measured using a Ford 2.3 L port fuel injection spark-ignition internal combustion engine according to the industry standard test method: ASTM D-6201.

[0194] These data illustrate a method of controlling sludge formation in a spark-ignition internal combustion engine which method comprises supplying to the engine a fuel composition which comprises a combination of:

[0195] a. a hydrocarbyl-substituted aromatic compound; and

[0196] b. a polyalkylene amine.

[0197] The data also illustrate the use as a sludge controlling additive in a fuel composition for a spark-ignition internal combustion engine of:

[0198] a. a hydrocarbyl-substituted aromatic compound; and

[0199] b. a polyalkylene amine.

[0200] The data also illustrate a method of reducing the sludge forming tendency of a fuel composition for use in a spark-ignition internal combustion engine which method comprises incorporating into the fuel composition in one or more steps:

[0201] a. a hydrocarbyl-substituted aromatic compound; and

[0202] b. a polyalkylene amine

to produce a fuel composition which comprises said additives in combination and which on use in a spark-ignition internal combustion engine produces less sludge than the sludge formed when using in said engine the fuel composition without said combination of additives.

[0203] The data also illustrate that the sludge control performance of a fuel composition comprising a combination of a hydrocarbyl-substituted aromatic compound and a polyalkylene amine is improved relative to that of a fuel composition which comprises a polyalkylene amine, but does not comprise a hydrocarbyl-substituted aromatic compound. The sludge control performance of a fuel composition comprising a combination of a hydrocarbyl-substituted aromatic compound and a polyalkylene amine may also be improved relative to that of a fuel composition which comprises a hydrocarbyl-substituted aromatic compound, but does not comprise a polyalkylene amine. Accordingly, in some examples, an additive composition comprising a combination of:

[0204] a. a hydrocarbyl-substituted aromatic compound; and

[0205] b. a polyalkylene amine

is used for improving the sludge control performance of a fuel composition in a spark-ignition internal combustion engine.