Quaternary Ammonium Compound and Fuel Composition

Abstract

A quaternary ammonium compound of formula (I): wherein R.sup.0, R.sup.1, R.sup.2 and R.sup.3 is each independently an optionally substituted hydrocarbyl group; X is a linking group; R.sup.4 is an optionally substituted alkylene group; n is a positive integer; W is O.sup.− or OH; b is 1 when W is OH, and b is 2 when W is O.sup.−.

##STR00001##

Claims

1. A quaternary ammonium compound of formula (I): ##STR00031## wherein R.sup.0, R.sup.1, R.sup.2 and R.sup.3 is each independently an optionally substituted hydrocarbyl group; X is a linking group; R.sup.4 is an optionally substituted alkylene group; n is a positive integer; W is O.sup.− or OH; b is 1 when W is OH, and b is 2 when W is O.sup.−.

2. A method of preparing a quaternary ammonium compound, the method comprising reacting (a) a tertiary amine of formula R.sup.1R.sup.2R.sup.3N with (b) an epoxide; in the presence of (c) a compound of formula (IIB): ##STR00032## wherein R.sup.4 is an optionally substituted alkylene group; n is 0 or a positive integer; C is at least 1; W is O.sup.− or OH; b is 1 when W is OH, and b is 2 when W is O.sup.−.

3. A composition comprising a quaternary ammonium compound of formula (I): ##STR00033## wherein R.sup.0, R.sup.1, R.sup.2 and R.sup.3 is each independently an optionally substituted hydrocarbyl group; X is a linking group; R.sup.4 is an optionally substituted alkylene group; n is a positive integer; c is at least 1; W is O.sup.− or OH; b is 1 when W is OH, and b is 2 when W is O.sup.−.

4. The composition according to claim 3 wherein the composition is an additive composition for a fuel or lubricating oil.

5. The composition according to claim 3 wherein the composition is a fuel composition, preferably a diesel fuel composition.

6. (canceled)

7. A method of improving the performance of an engine, the method comprising combusting in the engine a fuel composition comprising as an additive a quaternary ammonium compound of formula (I): ##STR00034## wherein R.sup.0, R.sup.1, R.sup.2 and R.sup.3 is each independently an optionally substituted hydrocarbyl group; X is a linking group; R.sup.4 is an optionally substituted alkylene group; n is a positive integer; c is at least 1; W is O.sup.− or OH; b is 1 when W is OH, and b is 2 when W is O.sup.−.

8. The compound according to claim 1 wherein the anion precursor of formula (IIB) is derived from a hydrocarbyl substituted succinic acid or a hydrocarbyl substituted succinic anhydride.

9. The compound according to claim 1 wherein each X is a moiety CH.sub.2CHR or CRHCH.sub.2 in which R is an alkyl or alkenyl group having 6 to 36 carbon atoms.

10. The compound according to claim 1 wherein each R.sup.4 is ethylene or propylene, preferably —CH.sub.2CH.sub.2— or —CH(CH.sub.3)CH.sub.2—, more preferably —CH(CH.sub.3)CH.sub.2—.

11. The compound according to claim 1 wherein n is from 1 to 20.

12. The compound according to claim 1 wherein each of R.sup.1 and R.sup.2 is independently an optionally substituted alkyl group having from 1 to 12 carbon atoms.

13. The compound according to claim 1 wherein R.sup.3 is an alkyl group having 1 to 24 carbon atoms.

14. The compound according to claim 1 wherein R.sup.3 is selected from benzyl, or a hydroxyalkyl or hydroxyalkoxyalkyl group having 2 to 20 carbon atoms.

15. The compound according to claim 1 wherein R.sup.3 is selected from: (1) a polyisobutenyl group having a number average molecular weight of from 100 to 5000, preferably from 450 to 2500; (2) an optionally substituted alkylene phenol moiety of formula (A) or (B) ##STR00035## wherein n is 0 to 4, preferably 1, R.sup.x is an optionally substituted hydrocarbyl group, R.sup.y is an optionally substituted alkyl, alkenyl or aryl group; and L is a linking group; and (3) a succinimide moiety of formula: ##STR00036## wherein R.sup.z is an optionally substituted hydrocarbyl group and Lisa linking group.

16. The compound according to claim 1 wherein R.sup.0 as is a group of formula: ##STR00037## wherein each of R.sup.9, R.sup.10, R.sup.11, R.sup.12 is independently selected from hydrogen or an optionally substituted alkyl, alkenyl or aryl group.

17. The composition according to claim 3 wherein the composition is a diesel fuel composition.

18. The composition according to claim 17 wherein the diesel fuel composition comprises one or more further detergents 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; and (vii) a substituted polyaromatic detergent additive.

19. The composition according to claim 3 wherein the diesel fuel composition comprises a mixture of two or more quarternary ammonium compounds.

20. The method according to claim 7 wherein the additive is used as a detergent to combat deposits in a diesel fuel composition in a diesel engine.

21. The method according to claim 7 which is carried out in a modern diesel engine having a high pressure fuel system.

22. The method according to claim 7 which achieves “keep clean” performance.

23. The method according to claim 7 which achieves “clean up” performance.

24. The method according to claim 20 wherein the deposits are injector deposits.

25. The method according to claim 24 wherein the deposits are internal diesel injector deposits.

26. The method according to claim 7 which achieves an improvement in performance 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.

27. The method according to claim 26 which provides an improvement in performance in modern diesel engines having a high pressure fuel system and provides an improvement in performance in traditional diesel engines.

28. (canceled)

29. The composition according to claim 3 which further comprises one or more further additives selected from lubricity improvers, corrosion inhibitors and cold flow improvers.

30. (canceled)

Description

EXAMPLE 1

[0553] Additive A1, a quaternary ammonium salt additive compound of the invention was prepared as follows:

[0554] (a) A mixture of alkenes having 20 to 24 carbon atoms was heated with 1.2 molar equivalents of maleic anhydride. On completion of the reaction excess maleic anhydride was removed by distillation. The anhydride value of the substituted succinic anhydride product was measured as 2.591 mmolg.sup.−1.

[0555] This product was then heated with 0.5 molar equivalents of polypropylene glycol having a number average molecular weight of 425, and the reaction was monitored by FTIR to provide the bis ester product.

[0556] (b) 1 molar equivalent of diethyl ethanolamine was reacted with 1.5 molar equivalents of butylene oxide and 6 molar equivalents of water at 60° C. in toluene for 10 hours in the presence of the bis ester provided in step (a) to form a quaternary ammonium compound. Volatiles were removed in vacuo.

[0557] In some embodiments one molar equivalent of amine per bis ester was used. In some embodiments two moles of amine were used per equivalent of bis ester.

[0558] Compounds A2 to A28, A30 and A31 detailed in table 1 were prepared by an analogous method.

[0559] Compounds A1 to A15 and A21 to A31 were prepared using one molar equivalent of amine per bis ester. This results in a quaternary ammonium salt including one ammonium cation and one proton per bis ester anion.

[0560] Compounds A16 to A20 were prepared using two molar equivalents of amine per bis ester. This results in a quaternary ammonium salt including two ammonium cations per bis ester anion.

TABLE-US-00001 TABLE 1 Compound R H-(OR.sup.4)n-OH Amine Epoxide A1 C20-24 polypropylene Diethyl Butylene glycol Mn425 ethanolamine oxide A2 C20-24 polypropylene Dimethyl Butylene glycol Mn425 ethanolamine oxide A3 C20-24 polypropylene Dimethyl Butylene glycol Mn425 benzylamine oxide A4 C20-24 polypropylene Dimethyl Butylene glycol Mn425 octadecylamine oxide A5 C20-24 polypropylene Dimethyl Styrene glycol Mn425 benzylamine oxide A6 C20-24 polypropylene Dimethyl Styrene glycol Mn425 octadecylamine oxide A7 C20-24 polypropylene Dimethyl Styrene glycol Mn425 aminoethoxyethanol oxide A8 C20-24 polypropylene Diethyl 2-ethylhexyl glycol Mn425 ethanolamine glycidyl ether A9 C20-24 polypropylene Dimethyl 2-ethylhexyl glycol Mn425 ethanolamine glycidyl ether A10 C20-24 polypropylene Dimethyl 2-ethylhexyl glycol Mn425 benzylamine glycidyl ether A11 C20-24 polypropylene Dimethyl 2-ethylhexyl glycol Mn425 octadecylamine glycidyl ether A12 C20-24 polypropylene Dimethyl 2-ethylhexyl glycol Mn425 aminoethoxyethanol glycidyl ether A13 C20-24 polypropylene Dimethyl dodecylepoxide glycol Mn425 ethanolamine A14 C20-24 polypropylene Dimethyl dodecylepoxide glycol Mn425 benzylamine A15 C20-24 polypropylene Dimethyl dodecylepoxide glycol Mn425 octadecylamine A16 C20-24 polypropylene Dimethyl Butylene glycol Mn425 octadecylamine oxide A17 C20-24 polypropylene Dimethyl Styrene glycol Mn425 benzylamine oxide A18 C20-24 polypropylene Dimethyl Styrene glycol Mn425 octadecylamine oxide A19 C20-24 polypropylene Dimethyl 2-ethylhexyl glycol Mn425 ethanolamine glycidyl ether A20 C20-24 polypropylene Dimethyl 2-ethylhexyl glycol Mn425 octadecylamine glycidyl ether A21 C20-24 polypropylene Dimethyl Butylene glycol Mn425 aminoethoxyethanol oxide A22 C20-24 polypropylene Diethyl Styrene glycol Mn425 ethanolamine oxide A23 C20-24 polypropylene Diethyl dodecylepoxide glycol Mn425 ethanolamine A24 C20-24 tripropylene Dimethyl 2-ethylhexyl glycol benzylamine glycidyl ether A25 C20-24 1,3-butanediol Dimethyl Styrene ethanolamine oxide A26 C20-24 1,3-butanediol Dimethyl 2-ethylhexyl ethanolamine glycidyl ether A27 C20-24 1,6-hexanediol Dimethyl 2-ethylhexyl ethanolamine glycidyl ether A28 C20-24 ethylene glycol Dimethyl 2-ethylhexyl ethanolamine glycidyl ether A29 C20-24/ tripropylene Dimethyl 2-ethylhexyl H* glycol ethanolamine glycidyl ether A30 C20-24 1,3-butanediol Dimethyl Butylene ethanolamine oxide A31 C20-24 tripropylene Dimethyl Butylene glycol ethanolamine oxide *Compound A29 is prepared by the following method:

[0561] (a) A mixture of alkenes having 20 to 24 carbon atoms was heated with 1.2 molar equivalents of maleic anhydride. On completion of the reaction excess maleic anhydride was removed by distillation.

[0562] This product was then heated with 1 molar equivalent of tripropylene glycol, which was calculated based on the charge weight and mean molecular weight of the alkenyl succinic anhydride as prepared above. The reaction was monitored by FTIR to provide the half ester product. The half ester product was then heated with one equivalent of succinic anhydride to form a bis ester product.

[0563] (b) 1 molar equivalent of dimethyl ethanolamine was reacted with 1 molar equivalent of 2-ethylhexylglycidyl ether and 6 molar equivalents of water at 95° C. in toluene for 10 hours in the presence of the bis ester provided in step (a) to form a quaternary ammonium compound. Volatiles were removed in vacuo.

EXAMPLE 2

[0564] Diesel fuel compositions were prepared by dosing additives to aliquots all drawn from a common batch of RF06 base fuel.

[0565] The compositions were tested in a screening test which correlates with performance at combatting IDIDs as measured in the DW10C test.

[0566] In this test a fuel composition is tested using a Jet Fuel Thermal Oxidation Test equipment. In this modified test 800 ml of fuel is flowed over a heated tube at pressures of approximately 540 psi. The test duration is 2.5 hours. At the end of the test the amount of deposit obtained on the tube is compared to a reference value.

[0567] The value shown in Table 2 is the percentage reduction in deposit thickness compared to base fuel.

TABLE-US-00002 TABLE 2 Average thickness Compound ppm active (% reduction) A1 (inventive) 120 88 A2 (inventive) 120 84 A3 (inventive) 120 87 A4 (inventive) 120 89 A5 (inventive) 120 89 A6 (inventive) 120 97 A7 (inventive) 120 92 A8 (inventive) 120 80 A9 (inventive) 120 95 A10 (inventive) 120 94 A11 (inventive) 120 93 A12 (inventive) 120 96 A13 (inventive) 120 82 A14 (inventive) 120 98 A15 (inventive) 120 92 A16 (inventive) 120 86 A17 (inventive) 120 83 A18 (inventive) 120 86 A19 (inventive) 120 86 A20 (inventive) 120 89 A21 (inventive) 120 90 A22 (inventive) 120 64 A23 (inventive) 120 58 A24 (inventive) 120 73 A25 (inventive) 120 73 A26 (inventive) 120 74 A27 (inventive) 120 74 A28 (inventive) 60 72 A29 (inventive) 60 53 A30 (inventive) 60 72 A31 (inventive) 60 74 C1 (comparative) 120 0 C2 (comparative) 120 2

[0568] Comparative additive C1 is dodecenyl substituted succinic acid.

[0569] Comparative additive C2 is a polyisobutenyl (PIB) substituted succinic acid where the PIB has a number average molecular weight of 1000.

[0570] Table 3 below shows the specification for RF06 base fuel.

TABLE-US-00003 TABLE 3 Limits Property Units Min Max Method Cetane Number 52.0 54.0 EN ISO 5165 Density at 15° C. kg/m.sup.3 833 837 EN ISO 3675 Distillation 50% v/v Point ° C. 245 — 95% v/v Point ° C. 345 350 FBP ° C. — 370 Flash Point ° C. 55 — EN 22719 Cold Filter Plugging ° C. — −5 EN 116 Point Viscosity at 40° C. mm.sup.2/sec 2.3 3.3 EN ISO 3104 Polycyclic Aromatic % m/m 3.0 6.0 IP 391 Hydrocarbons Sulphur Content mg/kg — 10 ASTM D 5453 Copper Corrosion — 1 EN ISO 2160 Conradson Carbon Residue % m/m — 0.2 EN ISO 10370 on 10% Dist. Residue Ash Content % m/m — 0.01 EN ISO 6245 Water Content % m/m — 0.02 EN ISO 12937 Neutralisation mg KOH/g — 0.02 ASTM D 974 (Strong Acid) Number Oxidation Stability mg/mL — 0.025 EN ISO 12205 HFRR (WSD1,4) μm — 400 CEC F-06-A-96 Fatty Acid Methyl Ester prohibited

EXAMPLE 3

[0571] The performance of fuel compositions of example 2 in modern diesel engines having a high pressure fuel system may be tested according to the CECF-98-08 DW 10 method. This is referred to herein as the DW10B test.

[0572] The engine of the injector fouling test is the PSA DW10BTED4. In summary, the engine characteristics are:

Design: Four cylinders in line, overhead camshaft, turbocharged with EGR

Capacity: 1998 cm.SUP.3

[0573] Combustion chamber: Four valves, bowl in piston, wall guided direct injection

Power: 100 kW at 4000 rpm

Torque: 320 Nm at 2000 rpm

[0574] Injection system: Common rail with piezo electronically controlled 6-hole injectors.
Max. pressure: 1600 bar (1.6×10.sup.8 Pa). Proprietary design by SIEMENS VDO
Emissions control: Conforms with Euro IV limit values when combined with exhaust gas post-treatment system (DPF)

[0575] This engine was chosen as a design representative of the modern European high-speed direct injection diesel engine capable of conforming to present and future European emissions requirements. The common rail injection system uses a highly efficient nozzle design with rounded inlet edges and conical spray holes for optimal hydraulic flow. This type of nozzle, when combined with high fuel pressure has allowed advances to be achieved in combustion efficiency, reduced noise and reduced fuel consumption, but are sensitive to influences that can disturb the fuel flow, such as deposit formation in the spray holes. The presence of these deposits causes a significant loss of engine power and increased raw emissions.

[0576] The test is run with a future injector design representative of anticipated Euro V injector technology.

[0577] It is considered necessary to establish a reliable baseline of injector condition before beginning fouling tests, so a sixteen hour running-in schedule for the test injectors is specified, using non-fouling reference fuel.

[0578] Full details of the CEC F-98-08 test method can be obtained from the CEC. The coking cycle is summarised below.

1. A warm up cycle (12 minutes) according to the following regime:

TABLE-US-00004 Duration Engine Speed Torque Step (minutes) (rpm) (Nm) 1 2 idle <5 2 3 2000 50 3 4 3500 75 4 3 4000 100
2. 8 hrs of engine operation consisting of 8 repeats of the following cycle

TABLE-US-00005 Duration Engine Speed Load Torque Boost Air After Step (minutes) (rpm) (%) (Nm) IC (° C.) 1 2 1750 (20) 62 45 2 7 3000 (60) 173  50 3 2 1750 (20) 62 45 4 7 3500 (80) 212  50 5 2 1750 (20) 62 45 6 10 4000 100 * 50 7 2 1250 (10) 20 43 8 7 3000 100 * 50 9 2 1250 (10) 20 43 10 10 2000 100 * 50 11 2 1250 (10) 20 43 12 7 4000 100 * 50 * for expected range see CEC method CEC-F-98-08
3. Cool down to idle in 60 seconds and idle for 10 seconds
4. 4 hrs soak period

[0579] The standard CEC F-98-08 test method consists of 32 hours engine operation corresponding to 4 repeats of steps 1-3 above, and 3 repeats of step 4. ie 56 hours total test time excluding warm ups and cool downs.

EXAMPLE 4

[0580] A diesel fuel composition comprising additive A26 (100 ppm active) was tested according to the CECF-98-08 DW10B test method described in example 3, modified to measure clean up performance as outlined below.

[0581] 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.

[0582] 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 additive.

[0583] FIG. 1 shows the power output of the engine when running the fuel composition comprising additive A26 over the test period.

EXAMPLE 5

[0584] The ability of additives of the invention to remove ‘Internal Diesel Injector Deposits’ (IDIDs) may be measured according to the test method CEC F-110-16, available from the Co-ordinating European Council. The test uses the PSA DW10C engine.

[0585] The engine characteristics as follows:

TABLE-US-00006 Design: Four cylinders in line, overhead camshaft, variable geometry turbocharger with EGR Capacity: 1997 cm.sup.3 Combustion chamber: Four valves, bowl in piston, direct injection Power: 120 kW @ 3750 rpm Torque: 340 Nm @ 2000 rpm Injection system: Common rail with solenoid type injectors Delphi Injection System Emissions control: Conforms to Euro V limit values when combined with exhaust gas post-treatment system

[0586] The test fuel (RF06) is dosed with 0.5 mg/kg Na in the form of Sodium Naphthenate+10 mg/kg Dodecyl Succinic Acid (DDSA).

[0587] The test procedure consists of main run cycles followed by soak periods, before cold starts are carried out.

[0588] The main running cycle consist of two speed and load set points, repeated for 6 hrs, as seen below.

TABLE-US-00007 Speed Torque Step (rpm) (N .Math. m) Duration (s) 1 3750 280 1470 1 - Ramp .fwdarw. 2 — — 30 2 1000  10 270 2 - Ramp .fwdarw. 1 — — 30

[0589] The ramp times of 30 seconds are included in the duration of each step.

[0590] During the main run, parameters including, Throttle pedal position, ECU fault codes, Injector balance coefficient and Engine stalls are observed and recorded.

[0591] The engine is then left to soak at ambient temperature for 8 hrs.

[0592] After the soak period the engine is re-started. The starter is operated for 5 seconds; if the engine fails to start the engine is left for 60 seconds before a further attempt. A maximum of 5 attempts are allowed.

[0593] If the engine starts the engine is allowed to idle for 5 minutes. Individual exhaust temperatures are monitored and the maximum Temperature Delta is recorded. An increased variation in Cylinder-to-Cylinder exhaust temperatures is a good indication that injectors are suffering from IDID. Causing them to either open slowly or stay open to long.

[0594] An example below of all exhaust temperatures with <30° C. deviation, indicating no sticking caused by IDID.

[0595] The complete test comprises of 6× Cold Starts, although the Zero hour Cold Start does not form part of the Merit Rating and 5×6 hr Main run cycles, giving a total of 30 hrs engine running time.

[0596] The recorded data is inputted into the Merit Rating Chart. This allows a Rating to be produced for the test. Maximum rating of 10 shows no issues with the running or operability of the engine for the duration of the test.

[0597] An example below:

TABLE-US-00008 Cold Start Exhaust temperature consistency Starting Exhaust Number of Temperature Attempts Max Cyi. Cold Start Maximum (1 = Maximum Deviation Start Y/N Merits first start) Deduction Merits Merits (° c.) Deduction Merits #0 not rated #1 Y 5 1 0 5 5 21.8 0 5 #2 Y 5 1 0 5 5 18.1 0 5 #3 Y 5 1 0 5 5 15.5 0 5 #4 Y 5 1 0 5 5 20.2 0 5 #5 Y 5 1 0 5 5 22.6 0 5 Total Merits 25 25

TABLE-US-00009 Main Run Operability Max Number Max Pedal Inject. of EDU Position at Balancing Main Maximum Fault Stall 1000 rpm/10 Coeff. Run Merits resets Deduction (Y/N) Deduction N .Math. m (%) Deduction (rpm) Deduction Merits #1 5 0 0 N 5 15.4 0 15 0 5 #2 5 0 0 N 5 13.5 0 15 0 5 #3 5 0 0 N 5 13.6 0 15 0 5 #4 5 0 0 N 5 13.8 0 15 0 5 #5 5 0 0 N 5 14.5 0 15 0 5 Global Rating - Summary (Merit/10) 10 25

EXAMPLE 6

[0598] The effectiveness of the additives of the invention in older traditional diesel engine types was assessed using a standard industry test—CEC test method No. CEC F-23-A-01.

[0599] This test measures injector nozzle coking using a Peugeot XUD9 A/L Engine and provides a means of discriminating between fuels of different injector nozzle coking propensity. Nozzle coking is the result of carbon deposits forming between the injector needle and the needle seat. Deposition of the carbon deposit is due to exposure of the injector needle and seat to combustion gases, potentially causing undesirable variations in engine performance.

[0600] The Peugeot XUD9 A/L engine is a 4 cylinder indirect injection Diesel engine of 1.9 litre swept volume, obtained from Peugeot Citroen Motors specifically for the CEC PF023 method.

[0601] The test engine is fitted with cleaned injectors utilising unflatted injector needles. The airflow at various needle lift positions have been measured on a flow rig prior to test. The engine is operated for a period of 10 hours under cyclic conditions.

TABLE-US-00010 Time Speed Torque Stage (secs) (rpm) (Nm) 1 30 1200 ± 30 10 ± 2 2 60 3000 ± 30 50 ± 2 3 60 1300 ± 30 35 ± 2 4 120 1850 ± 30 50 ± 2

[0602] The propensity of the fuel to promote deposit formation on the fuel injectors is determined by measuring the injector nozzle airflow again at the end of test, and comparing these values to those before test. The results are expressed in terms of percentage airflow reduction at various needle lift positions for all nozzles. The average value of the airflow reduction at 0.1 mm needle lift of all four nozzles is deemed the level of injector coking for a given fuel.