ADDITIVE AND FUEL COMPOSITIONS

Abstract

An additive composition, on use in a fuel in a spark-ignition internal combustion engine, controls the formation of sludge and piston varnish. When used in a direct injection spark-ignition internal combustion engine, particulate emissions and deposit formation on intake valves may also be controlled. When used in a port fuel injection spark-ignition internal combustion engine, the port fuel injection valve deposits may be reduced. The additive composition comprises a polyalkylene amine and a hydrocarbyl-substituted hydroxyaromatic compound. The additive compositions may be present in a fuel composition.

Claims

1-12. (canceled)

13. An additive composition for use in a fuel for a spark-ignition internal combustion engine or a compression-ignition gasoline internal combustion engine, said additive composition comprising: about 5% to about 55% by weight of a polyalkylene amine, said polyalkylene amine comprising a polyalkylene group that exhibits a number average molecular weight of from about 700 to about 1500; and about 3% to about 25% by weight of a hydrocarbyl-substituted hydroxyaromatic compound, said hydrocarbyl-substituted aromatic compound comprising a hydrocarbyl group that exhibits a number average molecular weight of from about 700 to about 1500 and has up to about 60 mol % vinylidene terminal groups.

14. The additive composition of claim 13, where said additive composition comprises: about 5% to about 25% by weight of a polyether carrier fluid.

15. The additive composition of claim 13, wherein the hydrocarbyl-substituted aromatic compound is a Mannich Base additive.

16. The additive composition of claim 13, wherein the polyalkylene amine is a polyisobutylene amine.

17. The additive composition of additive composition of claim 13, wherein the hydrocarbyl substituent of the aromatic compound is or comprises polyisobutylene.

18. The additive composition of claim 13, wherein the weight ratio of actives of the polyalkylene amine : the hydrocarbyl-substituted aromatic compound is in the range of from about 5:1 to about 1:5.

19. The additive composition of claim 13, wherein the a polyether carrier fluid is used at weight ratio of actives of the polyether carrier fluid : the combination of the polyalkylene amine and the hydrocarbyl-substituted aromatic compound is greater than about 1:2.

20. The additive composition of claim 13, wherein the polyalkylene amine comprises a polyalkylene group having at least about 60 mol % vinylidene terminal groups.

21. A fuel composition for use in a spark-ignition internal combustion engine or a compression-ignition gasoline internal combustion engine, said fuel composition comprising: about 50 ppm to about 300 ppm by weight of a polyalkylene amine, said polyalkylene amine comprising a polyalkylene group that exhibits a number average molecular weight of from about 700 to about 1500; and about 20 ppm to about 200 ppm by weight of a hydrocarbyl-substituted hydroxyaromatic compound, said hydrocarbyl-substituted aromatic compound comprising a hydrocarbyl group that exhibits a number average molecular weight of from about 700 to about 1500 and has up to about 60 mol % vinylidene terminal groups.

22. The fuel composition of claim 21, wherein said fuel composition comprises: about 20 ppm to about 300 ppm polyether carrier fluid.

23. The fuel composition of claim 21, wherein the hydrocarbyl-substituted aromatic compound is a Mannich Base additive.

24. The fuel composition of claim 21, wherein the polyalkylene amine is a polyisobutylene amine.

25. The fuel composition of claim 21, wherein the hydrocarbyl substituent of the aromatic compound is or comprises polyisobutylene.

26. The fuel composition of claim 21, wherein the weight ratio of actives of the polyalkylene amine:the hydrocarbyl-substituted aromatic compound is in the range of from about 5:1 to about 1:5.

27. The fuel composition of claim 21, wherein the a polyether carrier fluid is used at weight ratio of actives of the polyether carrier fluid:the combination of the polyalkylene amine and the hydrocarbyl-substituted aromatic compound is greater than about 1:2.

28. The fuel composition of claim 21, wherein the polyalkylene amine comprises a polyalkylene group having at least about 60 mol % vinylidene terminal groups.

29. An additive composition, which additive composition, on use in a fuel in a spark-ignition internal combustion engine, controls the formation of sludge and piston varnish; and which additive composition, when used in a direct injection spark-ignition internal combustion engine, controls particulate emissions and deposit formation on intake valves; and which additive composition, when used in a port fuel injection spark-ignition internal combustion engine, reduces the port fuel injection valve deposits.

30. A fuel composition containing the additive composition of claim 29.

Description

EXAMPLE 1

PFI Inlet Valve Clean-Up

[0192] Port fuel intake valve deposit (PFI IVD) “clean-up” and “keep-clean” performance were assessed using the US industry standard test method: ASTM D-6201 (also known as the Ford 2.3L “Ranger” engine test) using a Ford 2.3 L port fuel injection spark-ignition internal combustion engine. The ASTM D-6201 cycle is as shown in Table 2.

TABLE-US-00002 TABLE 2 Manifold Absolute Pressure Engine speed (engine load requirement) Duration Stage rpm kPa mm Hg minutes Ramp from 0 to (Transition) (Transition) (Transition) 0.5 2000 rpm Steady state 2000 30.6 230 4 Ramp from 2000 (Transition) (Transition) (Transition) 0.5 to 2800 rpm Steady state 2800 71.8 540 8

[0193] The engine was operated continuously according to the test cycle in Table 2 for a “dirty-up” period using a US market-regular gasoline to produce at least 400 mg deposit per valve. Then the engine was operated continuously according to the test cycle in Table 2 for a clean-up test period of 100 hours using the test fuel composition. Each port fuel intake valve was weighed at the start of the evaluation, after the interim “dirty-up” period and at the end of the evaluation. “Clean-up” was calculated for each valve as: 100×[(Interim valve weight)−(End of Test valve weight)]/[(Interim valve weight)−(Start of Test valve weight ]. An average of the values for the four valves was reported. The higher the result (higher % “clean-up”) the better the performance.

[0194] The clean-up evaluation was assessed using two different formulated E10 gasolines (referred to as E10a and E10b) containing either a PIBA additive or a combination of a PIBA additive and a Mannich Base. Different total treat rates of the PIBA or PIBA and Mannich combination were used. The data are shown in Tables 3 and 4.

TABLE-US-00003 TABLE 3 Clean up Concentration (% relative to (arbitrary units: clean-up of mass/volume) Experiment A) PIBA (E10a) - Experiment A 3.52 100 PIBA (E10a) 5.70 204 PIBA and Mannich Base (E10a) 2.88 120 PIBA and Mannich Base (E10a) 3.57 138 PIBA and Mannich Base (E10a) 4.47 199 *a high number indicates better clean-up performance

TABLE-US-00004 TABLE 4 Clean up Concentration (% relative to (arbitrary units: clean-up of mass/volume) Experiment B) PIBA (E10b) - Experiment B 3.52 100 PIBA (E10b) 5.70 137 PIBA and Mannich Base (E10b) 2.6 71 PIBA and Mannich Base (E10b) 2.88 62 PIBA and Mannich Base (E10b) 4.47 107 *a high number indicates better clean-up performance

[0195] The data in Tables 3 and 4 show that the fuel composition comprising in combination, at least one Mannich Base additive and at least one polyisobutylene amine exhibits beneficial port fuel injection intake valve deposit clean-up performance when used in a port fuel injection, spark-ignition internal combustion engine and in particular exhibits a beneficially steep gradient for performance versus treat rate response. This performance versus treat rate response can be seen in FIGS. 1 and 2.

EXAMPLE 2

DI Intake Valve Deposits Keep-Clean

[0196] Air intake valve deposit formation was studied using a gasoline base fuel meeting E0 R95 EN 228 specifications. Fuels were prepared with and without deposit controlling additives, and used to operate a 2.0 litre turbocharged direct injection spark ignition internal combustion engine. The engine was operated to induce blow-by flow into the engine inlet system just upstream of the air intake valves by operating a four-stage test cycle of steady-state stages running at engine speeds of between 1000 and 2000 rpm and with engine loads of between 1 and 5 bar Brake Mean Effective Pressure for a total duration of greater than 100 hours. The amount of PIBA additive or combined PIBA additive and Mannich Base additive used in the experiments was selected to give a typical port fuel injection intake valve deposit performance when measured using an M111 spark ignition internal combustion engine operated according to the industry standard test CEC-F-20-A-98. The mass of air intake valve deposits were determined by weighing the valves at the start and end of each test and subtracting the weight at the start from the weight at the end. The results are shown in Table 5.

TABLE-US-00005 TABLE 5 Air Intake Valve Deposits in DI spark-ignition engine Additive(s) (mass % relative to Experiment C) None (three repeat experiments) 100 - Experiment C  96 101 Polyisobutylene amine (two repeat 121 experiments) 122 Mannich Base Additive (I) and 105 Polyisobutylene Amine Two Mannich Additives (I and II) 131 Mannich Additive (II) 116 Mannich Additive (III) 107 *a low number indicates better keep-clean performance

[0197] The results in Table 5 show that incorporating into a fuel, a combination of Mannich Base additive and polyisobutylene amine reduces the direct injection air intake valve deposit forming tendency of the fuel composition when used in a direct injection spark-ignition internal combustion engine.

[0198] In a further experiment, the different fuel compositions were run on a 2.0 litre direct injection spark ignition internal combustion engine. Injector flow loss from each test was measured using static injector flow tests to confirm that the detergency effects of the different fuel compositions on the direct injectors were comparable.

EXAMPLE 3

Piston Varnish and Sludge Formation Keep-Clean

[0199] Intake valve deposit (IVD) keep-clean performance were assessed using the US industry standard test method: ASTM D-6201 (version 04, 2009) using a Ford 2.3 L port fuel injection spark-ignition internal combustion engine. Intake valve deposit (IVD) keep-clean performance was studied using an E10 gasoline base fuel. Sludge (engine sludge and rocker cover sludge) formation and piston varnish formation were assessed using the US industry standard test method: ASTM D-6593 (version 20100628) using a Ford 4.6L port fuel injection spark-ignition internal combustion engine. The standard reference fuel in ASTM D-6593, with additives of interest added therein, was used as the fuel, and the standard reference lubricant in ASTM D-6593 was used as the lubricant in the engine. The amount of additive used in the sludge and piston varnish formation tests was selected to give a typical port fuel injection valve keep-clean performance. The data are shown in Table 6.

TABLE-US-00006 TABLE 6 Engine sludge control performance Keep-clean Treat rate (% relative to base Piston varnish deposit performance (arbitrary fuel reference)* control performance (arbitrary units mass Rocker (% relative to base units) per volume) Engine cover fuel reference)* PIBA 10.0 20.0 113% 100% 106% PIBA and 9.9 18.9 115% 103% 115% Mannich *a high number indicates better control performance

[0200] The data generated demonstrate that the fuel composition comprising Mannich Base additive in combination with a polyisobutylene amine exhibits beneficial sludge and piston varnish formation control in a spark-ignition internal combustion engine:

EXAMPLE 4

Particulate Emissions

[0201] Particulate emissions were measured by assessing the number of particles emitted using a Condensation Particle Counter fitted to a 1.6 litre turbocharged direct-injection spark ignition internal engine. The Condensation Particle Counter meets the legislative requirements of the European Commission's PMP. The number of particles that were emitted from the engine was assessed after the engine had been running for 15 hours. The fuel that was used to determine the intake valve deposit keep-clean performance was splash blended with ethanol to form an Ell) gasoline base fuel for use in the engine tests. The amount of Mannich Base additive used in the experiment was selected to give a typical port fuel injection valve clean-up performance using the industry standard test method: CEC-F-20-A-98 (Issue 12). An E0 gasoline base fuel with a Research Octane Number of 95 was used. The fuel was EN 228 compliant. The data are shown in Table 7.

TABLE-US-00007 TABLE 7 15 hour particle number emissions Additives (arbitrary units) None 7.7 Mannich Additive 10.1 Two Mannich Additives 10.9 PIBA 5.2 Mannich Additive and PIBA 1.6 *a low number indicates particle number control performance

[0202] The data shown in Table 7 demonstrates that the fuel composition comprising a Mannich Base additive in combination with a polyisobutylene amine exhibits beneficial particulate emissions control in a direct-injection spark-ignition internal combustion engine.

[0203] Tests to determine the increase in injector pulse width over the 15 hour test cycle were also carried out, and demonstrate that a fuel compositions containing a Mannich Base additive and PIBA additive exhibits comparable injector pulse width increase control to a fuel composition which contains only PIBA additive. Increase in injector pulse width may be used as a measure of the detergency of fuel compositions.

[0204] These data illustrate that the fuel compositions of the present invention are able to exhibit a number of beneficial effects in different engines. In particular, the data show that, when used in a spark-ignition internal combustion engine, the additive composition controls sludge formation and piston varnish formation. The data also show that, when used in a direct injection spark-ignition internal combustion engine, the additive composition controls particulate emission and deposit formation on intake valves. The data also show that, when used in a port fuel injection spark-ignition internal combustion engine, the additive composition reduces the port fuel injection valve deposits.