COMPOSITIONS AND METHODS AND USES RELATING THERETO

Abstract

A fuel composition comprising as an additive the reaction product of a polycarboxylic acid having no more than 5 carbon atoms per carboxylic acid group, or an anhydride thereof and an alcohol having at least 5 carbon atoms.

Claims

1. A fuel composition comprising as an additive the reaction product of a polycarboxylic acid having no more than 5 carbon atoms per carboxylic acid group, or an anhydride thereof and an alcohol having at least 5 carbon atoms.

2. A method of improving the performance of an engine, the method comprising combusting in the engine a fuel composition comprising as an additive the reaction product of a polycarboxylic acid having no more than 5 carbon atoms per carboxylic acid group, or an anhydride thereof and an alcohol having at least 5 carbon atoms.

3. (canceled)

4. The composition according to claim 1 wherein the polycarboxylic acid or anhydride thereof is selected from citric acid, itaconic acid, citraconic acid, 2-methylene glutaric acid, 2-methylene adipic acid, isocitric acid, 2-hydroxycitric acid, malic acid, tartaric acid, 2-hydroxyadipic acid, 2-hydroxyglutaric acid, aconitic acid, and anhydrides and/or isomers thereof.

5. The composition according to claim 1 wherein the polycarboxylic acid or anhydride thereof is selected from citric acid, itaconic acid and itaconic anhydride.

6. The composition according to claim 1 wherein the alcohol is a compound of formula H—(OR).sub.n—OR.sup.1, wherein R is an optionally substituted alkylene group; R.sup.1 is an optionally substituted hydrocarbyl group; and n is 0 or a positive integer.

7. The composition according to claim 6 wherein the alcohol is selected from: alkanols of formula CH.sub.3(CH.sub.2).sub.xOH wherein x is from 4 to 23; branched or cyclic alkyl alcohols in which n is 0; alkenyl alcohols in which n is 0; and glycol ethers in which n is not 0.

8. The composition according to claim 6 wherein the alcohol is selected from: an alcohol of formula R.sup.1OH wherein R.sup.1 is an alkyl group having 8 to 30 carbon atoms; an alcohol of formula R.sup.1OH wherein R.sup.1 is an alkenyl group having 8 to 30 carbon atoms; and an alcohol of formula H—(OR).sub.n—OR.sup.1 wherein n is from 1 to 24, R is ethylene, propylene or isopropylene, and R.sup.1 is an unsubstituted alkyl group having 8 to 30 carbon atoms.

9. The composition according to claim 1 wherein the alcohol is selected from hexanol, octanol, nonanol, decanol, dodecanol, tetradecanol, cetyl alcohol, stearyl alcohol, 2-ethyl-1-butanol, 2-ethyl-1-hexanol, 2-ethyl-1-heptanol, 2-propylheptanol, 2-ethyl-1-decanol, 2-hexyl-1-decanol, 2-octyl-1-decanol, 2-hexyl-1-dodecanol, 2-octyl-1-dodecanol, 2-decyl-1-tetradecanol, isotridecanol, cyclohexanol, cyclooctanol, benzyl alcohol, citronellol, oleyl alcohol, 9-decen-1-ol, cis-3-hexen-1-ol, trans-2-hexen-1-ol, 5-hexen-1-ol, 6-methyl-5-hepten-2-ol, 1-octen-3-ol, trans-2-octen-1-ol, 10-undecen-1-ol and compounds of formula CH.sub.3(CH.sub.2).sub.xO(CH.sub.2CH(CH.sub.3)O).sub.yH or an isomer thereof wherein x is from 10 to 15, and y is from 10 to 20.

10. The composition according to claim 1 wherein the polycarboxylic acid or anhydride thereof and the alcohol are reacted in a molar ratio of from 2:1 to 1:2.

11. The composition according to claim 1 wherein the additive has an acid value of from 0.6 to 9.7 mmol H.sup.+/g.

12. The composition according to claim 1 wherein the fuel composition is a diesel fuel composition, which optionally comprises one or more further additives selected from: (i) a quaternary ammonium salt additive; (ii) the product of a Mannich reaction between an aldehyde, an amine and an optionally substituted phenol; (iii) the reaction product of a carboxylic acid-derived acylating agent and an amine; (iv) the reaction product of a carboxylic acid-derived acylating agent and hydrazine; (v) a salt formed by the reaction of a carboxylic acid with di-n-butylamine or tri-n-butylamine; (vi) the reaction product of a hydrocarbyl-substituted dicarboxylic acid or anhydride and an amine compound or salt which product comprises at least one amino triazole group; (vii) a substituted polyaromatic detergent additive; and (viii) partial esters of substituted succinic acids.

13. The composition according to claim 12 wherein the diesel fuel composition further comprises a quaternary ammonium salt additive; wherein the quaternary ammonium salt additive is the reaction product of a nitrogen-containing species having at least one tertiary amine group and a quaternising agent wherein the nitrogen containing species is 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; wherein the quaternising agent is an ester quaternising agent.

14. The composition according to claim 1 wherein the fuel composition is a gasoline fuel composition, which optionally comprises one or more further additives selected from: (p) hydrocarbyl—substituted polyoxyalkylene amines or polyetheramines; (q) acylated nitrogen compounds which are the reaction product of a carboxylic acid-derived acylating agent and an amine; (r) hydrocarbyl-substituted amines wherein the hydrocarbyl substituent is substantially aliphatic and contains at least 8 carbon atoms; (s) Mannich base additives comprising nitrogen-containing condensates of a phenol, aldehyde and primary or secondary amine; (t) aromatic esters of a polyalkylphenoxyalkanol; (u) an additional quaternary ammonium salt additive; and (v) tertiary hydrocarbyl amines having a maximum of 30 carbon atoms.

15. The method according to claim 2 which combats deposits in the engine.

16. The method according to claim 2 wherein the engine is a modern diesel engine having a high pressure fuel system.

17. The method according to claim 16 wherein the improvement in performance is selected from one or more of: a reduction in power loss of the engine; a reduction in external diesel injector deposits; a reduction in internal diesel injector deposits; an improvement in fuel economy; a reduction in fuel filter deposits; a reduction in emissions; and an increase in maintenance intervals.

18. The method according to claim 2 which combats internal diesel injector deposits.

19. The method according to claim 2 which achieves a maximum exhaust temperature deviation of less than 30° C. in the DW10C test.

20. The method according to claim 2 wherein the engine is a direct injection spark ignition engine.

21. The method according to claim 20 wherein the improvement in performance is selected from one or more of: improved fuel economy; reduced maintenance; less frequent overhaul or replacement of injectors; improved driveability; improved power; and improved acceleration.

22. The method according to claim 2 which achieves “keep clean” performance.

23. The method according to claim 2 which achieves “clean up” performance.

Description

EXAMPLE 10

[0490] A diesel fuel composition comprising additive A4 (14 ppm active) was tested according to the DW1OB test method outlined in Example 4 above.

[0491] FIG. 3 shows the power output of the engine when running the fuel compositions during the test.

EXAMPLE 11

[0492] A diesel fuel composition was prepared comprising 28 ppm additive A4 and 70 ppm of a quaternary ammonium salt additive.

[0493] The quaternary ammonium salt additive was prepared by quaternising the reaction product of a polyisobutylene-substituted succinic anhydride having a PIB number average molecular weight of 1000 and dimethylaminopropylamine by reaction with methyl salicylate.

[0494] The composition was tested according to the CECF-98-08 DW10B test method described in example 4, modified as outlined below.

[0495] A first 32 hour cycle was run using new injectors and RF-06 base fuel having added thereto 1 ppm Zn (as neodecanoate). This resulted in a level of power loss due to fouling of the injectors.

[0496] A second 32 hour cycle was then run as a ‘clean up’ phase. The dirty injectors from the first phase were kept in the engine and the fuel changed to RF-06 base fuel having added thereto 1 ppm Zn (as neodecanoate) and the test additives detailed above.

[0497] FIG. 4 shows the power output of the engine when running the fuel compositions over the test period.

EXAMPLE 12

[0498] A diesel fuel composition comprising additive A4 (70 ppm active) was also tested according to the method of Example 5. A final merit rating of 10 was achieved. The full results are provided in table 4.

EXAMPLE 13

[0499] A diesel fuel composition comprising additive A3 (140 ppm active) was also tested according to the method of Example 5. A final merit rating of 10 was achieved. The full results are provided in table 5.

TABLE-US-00011 TABLE 5 Cold Start Starting Exhaust temperature consistency Number Exhaust of Temperature Attempts Max Cylinder Cold Start Maximum (1 = first Maximum Deviation Start Y/N Merits start) Deduction Merits Merits (° C.) Deduction Merits #0 not rated #1 Y 5 1 0 5 5 4.8 0 5 #2 Y 5 1 0 5 5 7.9 0 5 #3 Y 5 1 0 5 5 17.8 0 5 #4 Y 5 1 0 5 5 12.3 0 5 #5 Y 5 1 0 5 5 19.3 0 5 Total merits 25 25 Main Run Operability Max Pedal Number of Position at Max Inject. Main Maximum EDU Fault Stall 1000 rpm/ Balancing Run Merits resets Deduction (Y/N) Deduction 10 N.m (%) Deduction Coeff. (rpm) Deduction Merits #1 5 0 0 N 5 16.4 0 9.2 0 5 #2 5 0 0 N 5 16.8 0 10.8 0 5 #3 5 0 0 N 5 16.3 0 9.8 0 5 #4 5 0 0 N 5 18.7 0 10.3 0 5 #5 5 0 0 N 5 19.2 0 9.7 0 5 Global Rating-Summary (Merit/10) 10 25

TABLE-US-00012 TABLE 6 Cold Start Starting Exhaust temperature consistency Number Exhaust of Temperature Attempts Max Cylinder Cold Start Maximum (1 = first Maximum Deviation Start Y/N Merits start) Deduction Merits Merits (° C.) Deduction Merits #0 not rated #1 Y 5 1 0 5 5 6.3 0 5 #2 Y 5 1 0 5 5 3.4 0 5 #3 Y 5 1 0 5 5 6.6 0 5 #4 Y 5 1 0 5 5 4.6 0 5 #5 Y 5 1 0 5 5 4.0 0 5 Total merits 25 25 Main Run Operability Max Pedal Number of Position at Max Inject. Main Maximum EDU Fault Stall 1000 rpm/ Balancing Run Merits resets Deduction (Y/N) Deduction 10 N.m (%) Deduction Coeff. (rpm) Deduction Merits #1 5 0 0 N 5 17.6 0 8.3 0 5 #2 5 0 0 N 5 17.7 0 8.3 0 5 #3 5 0 0 N 5 18.0 0 8.4 0 5 #4 5 0 0 N 5 18.6 0 8.7 0 5 #5 5 0 0 N 5 18.5 0 8.7 0 5 Global Rating-Summary (Merit/10) 10 25