METHODS AND USES RELATING TO FUEL COMPOSITIONS

Abstract

A method of removing deposits in a direct injection spark ignition engine, the method including combusting in the engine a gasoline fuel composition having a quaternary ammonium salt additive wherein the quaternary ammonium salt additive includes the quaternised reaction product of a hydrocarbyl substituted succinic acid derived acylating agent and a compound able to react with said acylating agent and which includes a tertiary amine group; in which each molecule of the hydrocarbyl substituted succinic acid derived acylating agent includes on average at least 1.2 succinic acid moieties.

Claims

1. A method of removing deposits in a direct injection spark ignition engine, the method comprising combusting in the engine a gasoline fuel composition comprising a quaternary ammonium salt additive wherein the quaternary ammonium salt additive comprises the quaternised reaction product of a hydrocarbyl substituted succinic acid derived acylating agent and a compound able to react with said acylating agent and which includes a tertiary amine group; wherein each molecule of the hydrocarbyl substituted succinic acid derived acylating agent includes on average at least 1.2 succinic acid moieties.

2. The use of a combination of a quaternary ammonium salt additive in a gasoline fuel composition to remove deposits in a direct injection spark ignition engine; wherein the quaternary ammonium salt additive comprises the quaternised reaction product of a hydrocarbyl substituted succinic acid derived acylating agent and a compound able to react with said acylating agent and which includes a tertiary amine group; wherein each molecule of the hydrocarbyl substituted succinic acid derived acylating agent includes on average at least 1.2 succinic acid moieties.

3. The method of claim 1, wherein the hydrocarbyl substituted succinic acid derived acylating agent is a polyisobutene-substituted succinic acid or succinic anhydride wherein the polyisobutene substituent has a number average molecular weight of between 450 to 2300.

4. The method of claim 1, claim wherein the compound able to react with the hydrocarbyl substituted succinic acid derived acylating agent and which includes a tertiary amine group comprises one or more compounds formed by the reaction of a hydrocarbyl-substituted acylating agent and an amine of formula (I) or (II): ##STR00010## wherein R.sup.2 and R.sup.3 are the same or different alkyl, alkenyl, aryl, alkaryl or aralkyl groups having from 1 to 22 carbon atoms; X is an optionally substituted alkylene group having from 1 to 20 carbon atoms; n is from 0 to 20; m is from 1 to 5; and R.sup.4 is hydrogen or a C.sub.1 to C.sub.22 alkyl group.

5. The method of claim 4, wherein X is a propylene group.

6. The method of claim 1, wherein the quaternising agent used to prepare the quaternary ammonium salt additive is selected from the group consisting of an ester of a carboxylic acid, dialkyl sulfates, benzyl halides, hydrocarbyl substituted carbonates, hydrocarbyl substituted epoxides optionally in combination with an acid, alkyl halides, alkyl sulfonates, sultones, hydrocarbyl substituted phosphates, hydrocarbyl substituted borates, alkyl nitrites, alkyl nitrates, hydroxides, N-oxides, chloroacetic acid or salts thereof, or mixtures thereof.

7. The method of claim 1, wherein the quaternising agent used to prepare the quaternary ammonium salt additive is selected from the group consisting of dialkyl sulfates, benzyl halides, hydrocarbyl substituted carbonates, hydrocarbyl substituted epoxides in combination with an acid, alkyl halides, alkyl sulfonates, sultones, hydrocarbyl substituted phosphates, hydrocarbyl substituted borates, N-oxides, chloroacetic acid or salts thereof, or mixtures thereof.

8. The method of claim 1, wherein the quaternising agent used to prepare the quaternary ammonium salt additive is a compound of formula (III): ##STR00011## wherein R is an optionally substituted alkyl, alkenyl, aryl or alkylaryl group and R.sup.1 is a C.sub.1 to C.sub.22 alkyl, aryl or alkylaryl group.

9. The method of claim 8, wherein the quaternizing agent is selected from dimethyl oxalate, methyl 2-nitrobenzoate and methyl salicylate.

10. The method of claim 8, wherein the quaternizing agent is an ester of a polycarboxylic acid.

11. The method of claim 1, claim wherein the gasoline fuel composition comprises one or more additional deposit control additives.

12. The method of claim 11, wherein the one or more additional deposit control additives comprises the product of a Mannich reaction between an aldehyde, an amine and an optionally substituted phenol.

13. The method of claim 12, wherein the one or more additional deposit control additives comprises the product of a Mannich reaction between: (x) formaldehyde; (y) a an amine selected from polyethylene polyamines, dimethylaminopropylamine and dialkylamines; and (z) a polyisobutenyl-substituted phenol or cresol having a polyisobutenyl substituent number average molecular weight of from 500 to 3000.

14. The method of claim 11, wherein the one or more additional deposit control additives comprises a hydrocarbyl substituted amine.

15. The method of claim 1, wherein the gasoline fuel composition comprises a friction modifier compound.

16. The method of claim 1, wherein the gasoline fuel composition comprises 0.01 to 20 ppm of the quaternary ammonium salt additive.

17. The method of claim 1, which restores the injection time to within 10% of the initial injection time when using clean injectors within 10 hours.

Description

EXAMPLE 1PREPARATION OF POLYISOBUTYLENESUCCINIC ANHYDRIDE (PIBSA)INVENTIVE

[0238] 700 g (0.7 mol) of polyisobutylene (M.sub.n 1000) was charged to a nitrogen flushed, jacketed reactor fitted with an overhead stirrer. The starting material was heated to 120 C. with stirring and nitrogen inerting was repeated. The reaction temperature was increased to 190 C. and maleic anhydride (82.4 g, 0.84 mol, 1.2 eq) was charged over 1 hour. After maintaining a temperature of 190 C. for a further 1 hour, the temperature was increased to 200-208 C. and held in this range for 8 hours. Vacuum (<30 mbar) was then applied for 2.5 hrs, whilst maintaining the reaction temperature, which reduced the level of residual maleic anhydride to 0.05 wt %. The reaction mass was cooled to 80 C. then discharged from the reactor.

EXAMPLE 2PREPARATION OF PIBSACOMPARATIVE

[0239] The synthesis procedure was substantially identical to Example 1 and used the same grade of polyisobutylene (Mn 1000). The charge of maleic anhydride was reduced (1 eq relative to polyisobutylene) and the reaction was held between 190-210 C. during the 8 hour heating period. Residual maleic anhydride was also measured as 0.05 wt %.

[0240] The properties of the reaction products of Examples 1 and 2 are summarised in Table 1.

TABLE-US-00001 TABLE 1 Molecular Acid Unreacted weight of PIB value PIB starting P Example (mmolH+/g) (wt %) material (Mn) value 1 1.89 18.5 1000 1.31 2 1.68 20.2 1000 1.17

EXAMPLE 3ADDITIVE Q1INVENTIVE

[0241] PIBSA prepared according to Example 1 was charged to a nitrogen flushed, jacketed reactor fitted with an overhead stirrer and heated to 120 C. 3-(dimethylamino)propylamine (DMAPA) (1 eq relative to anhydride groups) was charged slowly, maintaining the reaction temperature between 120-130 C. After stirring at 120 C. for a further 1 hr, the reaction temperature was increased to 140 C. and held for 3 hrs with concurrent distillation of water. Methyl salicylate (2.1 eq relative to anhydride groups) was added in a single portion and heating was continued at 140 C. for 10 hours. The reaction mass was diluted with Aromatic 150 solvent to provide an overall solids content of 60 wt % prior to discharging from the reactor.

EXAMPLE 4ADDITIVE Q2COMPARATIVE

[0242] PIBSA prepared according to Example 2 was charged to a nitrogen flushed, jacketed reactor fitted with an overhead stirrer and heated to 90 C. 3-(dimethylamino)propylamine (DMAPA) (1 eq relative to anhydride groups) was charged slowly, maintaining the reaction temperature between 90-100 C. After stirring at 90-100 C. for a further 1 hr, the reaction temperature was increased to 140 C. and held for 4 hrs with concurrent distillation of water. 2-ethylhexanol was added to adjust the solids content to 60 wt % then methyl salicylate (1 eq relative to anhydride groups) was added in a single portion and heating was continued at 140 C. for 15 hours. The reaction mass was cooled to 60 C. prior to discharging from the reactor.

EXAMPLE 5PREPARATION OF DMAPA POLYISOBUTYLENE SUCCINIMIDE PROPYLENE OXIDE/ACETIC ACID QUATERNARY AMMONIUM SALTINVENTIVE

[0243] PIBSA according to Example 1 was charged to a nitrogen flushed, jacketed reactor fitted with an overhead stirrer and heated to 120 C. 3-(dimethylamino)propylamine (DMAPA) (1 eq relative to anhydride groups) was charged slowly, maintaining the reaction temperature between 120-130 C. After stirring at 120 C. for a further 1 hr, the reaction temperature was increased to 140 C. and held for 3 hrs with concurrent distillation of water. The reaction mass was cooled to room temperature, then acetic acid (0.71 eq relative to anhydride groups), 2-ethylhexanol (1.34 eq relative to anhydride groups) and water (0.81 eq relative to anhydride groups) were added. The reaction mass was heated to 75 C. and propylene oxide (2.39 eq relative to anhydride groups) was added over 3 hrs via a dropping funnel. Heating was continued for 4 hrs. The reaction mass was diluted with Aromatic 150 solvent to provide an overall solids content of 60 wt % prior to discharging from the reactor.

EXAMPLE 6PREPARATION OF DMAPA POLYISOBUTYLENE SUCCINIMIDE PROPYLENE OXIDE/ACETIC ACID QUATERNARY AMMONIUM SALTCOMPARATIVE

[0244] PIBSA according to Example 2 was used. Formation of the DMAPA succinimide and subsequent quaternization using propylene oxide/AcOH was carried out in identical manner to Example 5. Reactant charges were calculated relative to anhydride groups in the PIBSA starting material.

EXAMPLE 7PREPARATION OF DMAPA POLYISOBUTYLENE SUCCINAMIDE PROPYLENE OXIDE QUATERNARY AMMONIUM SALTINVENTIVE

[0245] PIBSA according to Example 1 (1 part) and Caromax 20 (1 part) were charged to a nitrogen flushed, jacketed reactor fitted with an overhead stirrer and heated to 80 C. to ensure proper mixing, then cooled to room temperature. 3-(dimethylamino)propylamine (DMAPA) (1 eq relative to anhydride groups in the PIBSA starting material) was added over 3 hrs, maintaining the reaction temperature below 40 C. The reaction mass was stirred for a further 4 hrs, then propylene oxide (2 eq relative to anhydride groups) was added over 3 hrs, then the reaction mass stirred at room temperature for 4 hrs. After nitrogen sparging to remove residual propylene oxide, the reaction mass was discharged from the reactor.

EXAMPLE 8PREPARATION OF DMAPA POLYISOBUTYLENE SUCCINAMIDE PROPYLENE OXIDE QUATERNARY AMMONIUM SALTCOMPARATIVE

[0246] PIBSA according to Example 2 was used. Formation of the DMAPA succinamide and subsequent quaternization using propylene oxide was carried out in identical manner to Example 7. Reactant charges were calculated relative to anhydride groups.

EXAMPLE 9ADDITIVE A1

[0247] Additive A1, a Mannich reaction product additive of the prior art was prepared as follows:

[0248] A 1 L reactor was charged with dodecylphenol (170.6 g, 0.65 mol), ethylenediamine (30.1 g, 0.5 and Caromax 20 (123.9 g). The mixture was heated to 95 C. and formaldehyde solution, 37 wt % (73.8 g, 0.9 mol) charged over 1 hour. The temperature was increased to 125 C. for 3 hours and water removed. In this example the molar ratio of aldehyde (a): amine (b): phenol (c) was approximately 1.8:1:1.3.

EXAMPLE 10ADDITIVE A2

[0249] Additive A2 is a 60 wt % active ingredient solution (in aromatic solvent) of a polyisobutenyl succinimide obtained from the condensation reaction of a polyisobutenyl succinic anhydride (PIBSA) derived from polyisobutene of Mn approximately 750 with a polyethylene polyamine mixture of average composition approximating to tetraethylene pentamine. The product was obtained by mixing the PIBSA and polyethylene polyamine at 50 C. under nitrogen and heating at 160 C. for 5 hours with removal of water.

EXAMPLE 11

[0250] A gasoline fuel composition was prepared by adding 6 ppm active by weight of additive Q1 to an EO gasoline fuel according to DIN EN 228 from Haltermann Carless (DISI TF Low Sulphur, Batch II1503T456, Orig. Batch 8). The gasoline fuel had the following specification:

TABLE-US-00002 Limits Feature Units Results Minimum Maximum Method RON (*.sup.1) 96.4 98.0 DIN EN ISO 5164: 2014-10 MON (*.sup.1) 87.3 87.0 DIN EN ISO 5163: 2014-10 Density at 15 C. kg/m3 748.8 745.0 760.0 ASTM D4052: 2018a DVPE kPa 62.4 60.0 65.0 DIN EN 13016-1: 2018-06 Appearance clear and HM-32 (Visual) bright Distillation IBP C. 32.1 25.0 35.0 DIN EN ISO 3405: 2019-09 Dist. 10% v/v C. 50.7 45.0 55.0 DIN EN ISO 3405: 2019-09 Dist. 50% v/v C. 102.2 95.0 110.0 DIN EN ISO 3405: 2019-09 Dist. 90% v/v C. 173.0 160.0 180.0 DIN EN ISO 3405: 2019-09 Dist. 70degC %(V/V) 26.8 22.0 50.0 DIN EN ISO 3405: 2019-09 Dist. 100degC %(V/V) 48.4 46.0 71.0 DIN EN ISO 3405: 2019-09 Dist. 150degC %(V/V) 82.2 75.0 DIN EN ISO 3405: 2019-09 Distillation FBF C. 197.3 190.0 210.0 DIN EN ISO 3405: 2019-09 Dist. Residue %(V/V) 1.0 2.0 DIN EN ISO 3405: 2019-09 Oxidation Stabilit (*.sup.1) min. >480 480 DIN EN ISO 7536: 1996-08 Solvent Washed Gum mg <0.5 per 4.0 DIN EN ISO 6246: 2020-01 100 mL Aromatics %(V/V) 31.9 35.0 DIN EN ISO 22854: 2016 Olefins %(V/V) 13.3 10.0 14.0 DIN EN ISO 22854: 2016 Saturates %(V/V) 54.7 DIN EN ISO 22854: 2016 Benzene %(V/V) 0.22 1.00 DIN EN ISO 22854: 2016 Corrosion - Copper 1A DIN EN ISO 2160: 1999-04 max. 1 Oxygenates %(V/V) <0.20 modified, 0.20 DIN EN ISO 22854: 2016 not accredited Oxygenates %(V/V) <0.80 0.80 DIN EN ISO 22854: 2016 Hydrogen % w 13.23 ASTM D3343: 2016 Carbon % w 86.77 ASTM D3343: 2016 C:H Ratio (H = 1) 6.56 ASTM D3343: 2016 H:C Ratio (C = 1) 0.153 ASTM D3343: 2016 Net Heating Value MJ/kg 42.844 ASTM D3338: 2009 Net Heating Value Btu/lb 18420 ASTM D3338: 2009 Lead (*.sup.1) mg/l <2.5 5.0 ASTM D3237: 2017 Sulfur mg/kg 3.6 10.0 DIN EN ISO 20846: 2019-12 Phosphorus (*.sup.1) g/l <0.0002 0.0013 ASTM D3231: 2018 Manganese (*.sup.1) mg/l <0.50 2.00 DIN EN 16136: 2015-04 Al (*.sup.1) mg/kg <0.1 0.1 ICP-OES B (*.sup.1) mg/kg <0.1 0.1 ICP-OES Ba (*.sup.1) mg/kg <0.1 0.1 ICP-OES Ca (*.sup.1) mg/kg <0.1 0.1 ICP-OES Cr (*.sup.1) mg/kg <0.1 0.1 ICP-OES Cu (*.sup.1) mg/kg <0.1 0.1 ICP-OES Fe (*.sup.1) mg/kg <0.5 5.0 ICP-OES Mg (*.sup.1) mg/kg <0.1 0.1 ICP-OES Mo (*.sup.1) mg/kg <0.1 0.1 ICP-OES Ni (*.sup.1) mg/kg <0.1 0.1 ICP-OES Si (*.sup.1) mg/kg <0.1 0.1 ICP-OES Zn (*.sup.1) mg/kg <0.1 0.1 ICP-OES

EXAMPLE 12

[0251] The fuel prepared in example 11 was tested according to a preliminary version of the upcoming CEC test for injector fouling in DISI engines (TDG-F-113) and was published by D. Weissenberger, J. Pilbeam, Characterisation of Gasoline Fuels in a DISI Engine, lecture held at Technische Akademie Esslingen, June 2017. The test engine is a VW EA111 1 4L TSI engine with 125 KW. The test procedure is a steady state test at an engine speed of 2000 rpm and a constant torque of 56 Nm. The test procedure is performed with the following injectors: Magneti Marelli 03C 906036 E. Reference oil RL-271 from Haltermann Carless was used as engine oil.

[0252] The dirty up phase involved running the engine for 48 hours using unadditised base fuel. Following addition of the additised fuel it took just four hours for the injection time to return to its initial level when using clean injectors.

[0253] This test was also carried out on the same base fuel comprising 6 ppm of additive Q2. In that case it took 12 hours for the injection time to return to its initial level when using clean injectors following addition of the additised fuel.