Fuel composition comprising a renewable base, a fatty acid ester and a polysiloxane additive

Abstract

The present invention relates to a fuel composition comprising one or more bases made of fatty acids and / or hydrogenated fatty acid esters in combination with at least one compound selected from fatty acid methyl and ethyl esters and at least one additive selected from polysiloxanes and oxyalkylated polysiloxanes. The present invention also relates to the use of such a fuel composition to power an engine, particularly a diesel engine.

Description

Title of the invention: Fuel composition comprising a renewable base, a fatty acid ester and a polysiloxane additive

[0001] The present invention relates to a fuel composition comprising one or more bases made up of fatty acids and / or esters of hydrogenated fatty acids such as hydrotreated vegetable oils in association with at least one compound selected from fatty acid methyl and ethyl esters and at least one additive selected from polysiloxanes and oxyalkylated polysiloxanes.

[0002] The present invention also relates to the use of such a composition to power an engine, in particular a Diesel type engine. PREVIOUS STATE OF THE ART

[0003] Combating climate change requires the development of new fuels with a low environmental impact. A promising solution is to replace the fossil-based fuels traditionally used with bio-based fuels, such as fuels derived from the hydrogenation of natural esters and fatty acids, known in English as Hydrogenated Esters and Fatty Acids (HEFA), for example, fuels derived from the hydrotreatment of vegetable oils, also known as HVO (hydrotreated vegetable oil). These fuels are essentially composed of linear and branched paraffins (alkanes).

[0004] The trend is to increasingly increase the proportion of these renewable bases relative to conventional bases derived from petroleum distillation, and even to formulate fuel compositions exclusively from such bases. In particular, for environmental and / or resource availability reasons, regulations in many countries encourage the introduction of increasing quantities of renewable bases, such as HEFA-type bases and especially HVOs, into fuels.

[0005] Continuing its research in the development of renewable fuel compositions, the Applicant sought to formulate compositions comprising such bases in mixture with fatty acid esters such as methyl esters and ethyl esters of fatty acids.

[0006] However, the formulation of fuel compositions from such mixtures has proven to pose a number of difficulties, in particular in controlling foaming.

[0007] Due to their manufacturing processes, but also because of water condensation during their transport and storage, fuel compositions can This includes a variable amount of water, which can be up to a few percent by mass. The presence of water generally leads to the formation of emulsions within the fuel, which can be relatively stable and are the cause of many problems during the transport, distribution, and combustion of the fuel.

[0008] For example, the formation of emulsions complicates and slows down vehicle fuel tank filling operations. Foam forms in fuel dispensing devices, leading to overflow during tank filling. Furthermore, the large volume occupied by the foam in the vehicle's tank results in insufficient filling. In addition, emulsions can clog engine filters and accelerate corrosion of engine parts.

[0009] The Applicant has observed that the addition of fatty acid esters, including at moderate levels of a few percent by mass, to bases made up of fatty acids and / or hydrogenated fatty acid esters, significantly increased foaming phenomena.

[0010] In addition, ionic detergent additives such as quaternary ammonium salts often used in fuel compositions tend to increase the stability of emulsions and slow down fuel demulsification. SUBJECT OF THE INVENTION

[0011] The present invention aims to remedy the problems described above.

[0012] The present invention aims in particular to propose a fuel composition based on a mixture of fatty acids and / or hydrogenated fatty acid esters (HEFA) with methyl or ethyl esters of fatty acids, which has improved properties.

[0013] The Applicant has now discovered that the addition, to a fuel base consisting of fatty acids and / or esters of hydrogenated fatty acids, of one or more methyl or ethyl esters of fatty acids in a minimum content of 2% by mass in association with one or more additives chosen from polysiloxanes and oxyalkylated polysiloxanes, makes it possible to formulate a fuel composition in which the formation of emulsions is substantially reduced.

[0014] The present invention thus relates to a fuel composition comprising: a) at least 50% by mass, relative to the total mass of the composition, of one or more paraffinic hydrocarbon cuts consisting of fatty acids and / or hydrogenated fatty acid esters (HEFA); b) at least 2% by mass, relative to the total mass of the composition, of one or more esters selected from fatty acid methyl esters and ethyl esters; and (c) one or more additives selected from polysiloxanes and oxy- polysiloxanes alkylated.

[0015] In particular, the Applicant unexpectedly discovered that the combination of fatty acid methyl and ethyl ester(s) and selected polysiloxane and oxyalkylated polysiloxane additive(s) made it possible to formulate fuel compositions based on fatty acids and / or hydrogenated fatty acid esters, such as hydrotreated vegetable oils, with very low foaming levels. Not only is the foam volume reduced, but also, and surprisingly, the foam dissipation time is significantly shortened.

[0016] The composition according to the invention exhibits an extremely low level of foaming, including when it contains substantial levels of ionic detergent additives such as, in particular, quaternary ammonium salts and / or betaines.

[0017] The aromatic hydrocarbon content of the composition according to the invention is advantageously less than 5% by mass, preferably less than 2% by mass, more preferably less than 1% by mass, relative to the total mass of the composition.

[0018] According to a preferred embodiment, the naphthenic hydrocarbon content of the composition according to the invention is less than 5% by mass, preferably less than 4% by mass, relative to the total mass of the composition.

[0019] According to a particularly preferred embodiment, the total content of naphthenic hydrocarbons and aromatic hydrocarbons of the composition according to the invention is less than 5% by mass, preferably less than 4% by mass, relative to the total mass of the composition.

[0020] Its excellent properties make the fuel composition usable in many applications including modern motor vehicles, in particular vehicles comprising a Diesel engine, including the most advanced engines such as very high pressure direct injection Diesel engines.

[0021] Other objects, features, aspects and advantages of the invention will become even clearer upon reading the description and examples that follow.

[0022] In what follows, and unless otherwise indicated, the bounds of a range of values ​​are included in that range, in particular in the expressions "between" and "ranging from ... to ...". Furthermore, the expressions "at least one" and "at least" used in this description are respectively equivalent to the expressions "one or more" and "greater than or equal to". Finally, in a manner known in itself, a compound or group in CN is designated as a compound or group containing in its chemical structure N carbon atoms.

[0023] DETAILED DESCRIPTION The paraffin hydrocarbon cut fa) The composition according to the invention comprises at least 50% by mass, relative to the total mass of the composition, of one or more paraffinic hydrocarbon fractions consisting of fatty acids and / or hydrogenated fatty acid esters (HEFAs).

[0024] The fatty acids and fatty acid esters can be derived from numerous sources, including vegetable oils and fats, animal oils and fats, and recycled oils (e.g., edible oils, cooking oils).

[0025] According to a preferred embodiment, the paraffinic hydrocarbon fraction(s) (a) consist of hydrotreated vegetable oils, also known as HVOs (from the English "hydrotreated vegetable oils"). These are oils of vegetable origin that have undergone successive treatments including hydrotreatment and optional isomerization. The processes for preparing such hydrotreated vegetable oils are known per se.

[0026] Examples of suitable vegetable raw materials for obtaining such hydrotreated vegetable oils include rapeseed oil, canola oil, sunflower oil, soybean oil, hemp oil, olive oil, linseed oil, mustard oil, palm oil, castor oil, coconut oil.

[0027] Patent applications WO2016 / 185046 and WO2016 / 185047 describe non-limiting examples of methods for obtaining hydrotreated vegetable oil cuts usable as fuel bases.

[0028] The paraffinic hydrocarbon cut(s) (a) have a distillation range advantageously within the range of 100 to 400°C, preferably from 130 to 350°C, and more preferably from 150 to 320°C.

[0029] The distillation range of said paraffinic hydrocarbon cut is determined in accordance with standard NF EN ISO 3405.

[0030] The paraffinic hydrocarbon cut(s) (a) advantageously have a paraffin content greater than or equal to 90% by mass, preferably greater than or equal to 95% by mass, and even better greater than or equal to 96% by mass, relative to the total mass of the cut(s) (a).

[0031] By "paraffins" is meant in a manner known per se branched alkanes (also called iso-paraffins or iso-alkanes) and unbranched alkanes (also called n-paraffins or n-alkanes).

[0032] The paraffins present in the paraffinic hydrocarbon cut(s) according to the invention advantageously comprise from 10 to 20 carbon atoms. Preferably, they are made up of at least 60% by mass, more preferably at least 80% by mass and even better at least 85% by mass of paraffins comprising from 12 to 18 carbon atoms, preferably from 14 to 18 carbon atoms, and even more preferably from 15 to 18 carbon atoms.

[0033] According to a preferred embodiment, the paraffinic hydrocarbon cut(s) (a) used in the composition according to the invention contain at least 60% by mass, preferably at least 70% by mass of isoparaffins, relative to the total mass of the cut(s) (a). According to a particularly preferred embodiment, they contain at least 80% by mass of isoparaffins, relative to the total mass of the cut(s) (a).

[0034] The paraffinic hydrocarbon cut(s) (a) have an aromatic compound content preferably less than or equal to 10000 ppm by mass, more preferably less than or equal to 1500 ppm by mass, even more preferably less than or equal to 1000 ppm by mass.

[0035] Their naphthenic compound content is preferably less than or equal to 40000 ppm by mass, more preferably less than or equal to 30000 ppm by mass.

[0036] Their sulfur content is advantageously less than or equal to 10 ppm by mass, preferably less than or equal to 5 ppm by mass. Particularly preferred, the paraffinic hydrocarbon cut(s) (a) are totally sulfur-free.

[0037] The composition according to the invention preferably comprises at least 75% by mass, relative to the total mass of the composition, of one or more paraffinic hydrocarbon fractions (a) as described above. Preferably, it contains at least 85% by mass of one or more paraffinic hydrocarbon fractions (a), more preferably at least 90% by mass and even better at least 92% by mass, relative to the total mass of the composition.

[0038] Methyl and ethyl esters of fatty acids (b) The composition according to the invention comprises one or more fatty acid methyl esters and / or one or more fatty acid ethyl esters.

[0039] By fatty acid, we mean a carboxylic acid comprising a saturated or unsaturated hydrocarbon chain having from 6 to 30 carbon atoms, preferably from 7 to 24 carbon atoms, and more preferably from 8 to 20 carbon atoms.

[0040] Said esters (b) are therefore chosen from among the esters of ethyl alcohol or methyl alcohol and one or more fatty acids as defined above.

[0041] These esters are products known per se. They can advantageously be obtained by reacting at least one oil chosen from vegetable oils, animal oils and used oils with methanol or ethanol, so as to obtain the corresponding esters by a chemical process called transesterification.

[0042] When the alcohol is methanol, a mixture of fatty acid methyl esters, also called EMAG, is obtained.

[0043] When the alcohol is ethanol, a mixture of ethyl esters of fatty acids, also called EEAG, is obtained.

[0044] According to a preferred embodiment, the ester(s) (b) are chosen from among the esters fatty acid methyl esters. Preferably, the composition according to the invention comprises, as esters (b), a mixture of fatty acid methyl esters (FAME).

[0045] The composition according to the invention comprises the ester(s) b) in a minimum content of 2% by mass, relative to the total mass of the composition. Preferably, it comprises the ester(s) b) in a content ranging from 2 to 12% by mass, preferably from 4 to 10% by mass, and even more preferably from 6 to 8% by mass, relative to the total mass of the composition.

[0046] According to a preferred embodiment, the composition according to the invention comprises the ester(s) b) in a content of 7% by mass, relative to the total mass of the composition.

[0047] Preferably, the composition according to the invention comprises a mixture of fatty acid methyl esters (FAME) in a minimum content of 2% by mass, relative to the total mass of the composition. Preferably, it comprises a mixture of fatty acid methyl esters (FAME) in a content ranging from 2 to 12% by mass, preferably from 4 to 10% by mass, and even better from 6 to 8% by mass, relative to the total mass of the composition.

[0048] According to a particularly preferred embodiment, the composition according to the invention comprises a mixture of fatty acid methyl esters (FAME) in a content of 7% by mass, relative to the total mass of the composition.

[0049] Polysiloxane additives fc) The fuel composition includes at least one additive selected from polysiloxanes and oxyalkylated polysiloxanes.

[0050] Preferably, the additive(s) (c) are chosen from polydialkylesiloxanes, and more preferably from polydimethylsiloxanes also known as dimethicones.

[0051] According to a preferred embodiment, the additive(s) (c) are selected from cyclic polydimethylsiloxanes containing 4 to 8 silicon atoms.

[0052] In a particularly preferred manner, the composition according to the invention contains decamethylcyclopentasiloxane.

[0053] The composition according to the invention comprises the additive(s) selected from polysiloxanes and oxyalkylated polysiloxanes (c) as described above in a preferential content of 5 to 100 ppm, preferably 8 to 50 ppm, and more preferably 10 to 20 ppm by mass, relative to the total mass of the composition.

[0054] The composition according to the invention advantageously comprises decamethylcyclopentasiloxane at a preferred content of 5 to 100 ppm, preferably 8 to 50 ppm, and more preferably 10 to 20 ppm by mass, relative to the total mass of the composition.

[0055] Detergent additives fd) According to a preferred embodiment, the fuel composition further comprises one or more detergent additives selected from quaternary ammonium salts, amido alkyl betaines and mixtures thereof.

[0056] In a first embodiment, the fuel composition comprises one or more detergent additives selected from quaternary ammonium salts, preferably selected from: (dl) the quaternized polyisobutylene-amines (PIBA); (d2) quaternized polyetheramines and (d3) quaternary ammonium salts obtained by reaction with a quaternizing agent of a nitrogen compound comprising a tertiary amine function, this nitrogen compound being the product of the reaction of an acylation agent substituted by a hydrocarbon group and a compound comprising at least one tertiary amine group and at least one group selected from primary amines, secondary amines and alcohols.

[0057] Quaternary ammonium salts (d3) are preferred. Thus, the fuel composition preferably comprises a detergent additive consisting of a quaternary ammonium salt, obtained by reaction with a quatemarizing agent of a nitrogen compound comprising a tertiary amine function, this nitrogen compound being the product of the reaction of an acylation agent substituted by a hydrocarbon group and a compound comprising at least one tertiary amine group and at least one group selected from primary amines, secondary amines and alcohols.

[0058] Said nitrogen compound is the product of the reaction of an acylation agent substituted by a hydrocarbon group and a compound comprising both an oxygen atom or a nitrogen atom capable of condensing with said acylation agent and a tertiary amine group.

[0059] The acylation agent is advantageously chosen from mono- or polycarboxylic acids and their derivatives, in particular their ester, amide, or anhydride derivatives. The acylation agent is preferably chosen from succinic, phthalic, and propionic acids and their corresponding anhydrides.

[0060] The acylation agent is substituted by a hydrocarbon group. A "hydrocarbon" group is understood to be any group having a carbon atom directly attached to the rest of the molecule (i.e. to the acylation agent) and having predominantly an aliphatic hydrocarbon character.

[0061] Hydrocarbon groups according to the invention may also contain non-hydrocarbon groups. For example, they may contain up to one non-hydrocarbon group per ten carbon atoms, provided that the non-hydrocarbon group does not significantly alter the predominantly hydrocarbon character of the group. Examples of such groups well known to those skilled in the art, hydroxyl groups, halogens (in particular chloro- and fluoro- groups), alkoxy groups, alkyl mercapto, alkyl sulfoxy.

[0062] However, hydrocarbon substituents not containing such non-hydrocarbon groups and having a purely aliphatic hydrocarbon character will be preferred.

[0063] The hydrocarbon substituent of the acylation agent preferably comprises at least 8, and preferably at least 12, carbon atoms. Said hydrocarbon substituent may comprise up to about 200 carbon atoms.

[0064] The hydrocarbon substituent of the acylation agent preferably has a number-average molecular weight (Mn) between 170 and 2800, for example between 250 and 1500, more preferably between 500 and 1500 and even more preferably between 500 and 1100. A range of Mn values ​​between 700 and 1300 is particularly preferred, for example from 700 to 1000.

[0065] As an example of hydrocarbon groups substituting for the acylation agent, n-octyl, n-decyl, n-dodecyl, tetrapropenyl, n-octadecyl, oleyl, octadecyl or triacontyl groups may be cited.

[0066] The hydrocarbon substituent of the acylation agent can also be obtained from homo- or interpolymers (e.g., copolymers, terpolymers) of mono- and di-olefins having from 2 to 10 carbon atoms, for example, from ethylene, propylene, 1-butene, isobutene, butadiene, isoprene, 1-hexene, or 1-octene. Preferably, these olefins are 1-mono-olefins.

[0067] The hydrocarbon substituent of the acylation agent can also be chosen from the derivatives of halogenated analogues (for example chlorinated or brominated) of these homo- or inter-polymers.

[0068] According to one embodiment, the hydrocarbon substituent of the acylation agent can be obtained from other sources, for example from high molecular weight alkene monomers (e.g., 1-tetracontene) and their chlorinated or hydrochlorinated analogues, from aliphatic petroleum fractions, for example paraffin waxes, their cracked, chlorinated and / or hydrochlorinated analogues, from white oils, from synthetic alkenes, for example produced by the Ziegler-Natta process (e.g. polyethylene fats) and from other sources known to those skilled in the art.

[0069] Any unsaturation present in the hydrocarbon group of the acylation agent can optionally be reduced or eliminated by hydrogenation according to any known process.

[0070] The hydrocarbon substituent of the acylation agent is preferably essentially saturated, that is to say, it does not contain more than one unsaturated carbon-carbon bond for every ten single carbon-carbon bonds present.

[0071] The hydrocarbon substituent of the acylation agent advantageously contains no more than one unsaturated non-aromatic carbon-carbon bond for every 50 carbon-carbon bonds present.

[0072] According to a preferred embodiment, the hydrocarbon substituent of the acylation agent is a polyisobutene (PIB) group. Highly reactive polyisobutenes (PIBs) are particularly preferred. Highly reactive polyisobutenes (PIBs) are defined as polyisobutenes (PIBs) in which at least 50 mole percent, preferably at least 70 mole percent or more, of the terminal olefinic double bonds are of the vinylidene type as described in document EP0565285. In particular, preferred PIBs are those having more than 80 mole percent and up to 100 mole percent of terminal vinylidene groups as described in document EP1344785.

[0073] According to a particularly preferred embodiment, the acylation agent substituted by a hydrocarbyl group is a polyisobutenyl-succinic anhydride (PIBSA).

[0074] The preparation of polyisobutenyl-succinic anhydrides is known per se, and widely described in the literature. Examples include the processes comprising the reaction between polyisobutenes (PIB) and maleic anhydride described in documents US3361673 and US3018250 or the process comprising the reaction of a halogenated polyisobutene (PIB), in particular chlorinated, with maleic anhydride (US3172892).

[0075] According to one embodiment, polyisobutenyl-succinic anhydride can be prepared by mixing a polyolefin with maleic anhydride and then passing chlorine through the mixture (GB949981).

[0076] Other hydrocarbon groups comprising an internal olefin, for example such as those described in application WO2007 / 015080, may also be used as a substitute for the acylation agent. An internal olefin is understood to be any olefin containing primarily a non-alpha double bond, which is a beta or higher position olefin.

[0077] Preferably, these materials are essentially beta-olefins or higher position olefins, for example containing less than 10% by mass of alpha-olefin, advantageously less than 5% by mass or less than 2% by mass.

[0078] Internal olefins can be prepared by isomerization of alpha-olefins according to any known process.

[0079] The compound comprising both an oxygen atom or a nitrogen atom capable of condensing with the acylation agent and a tertiary amine group may, for example, be selected from the group consisting of: N,N-dimethylaminopropylamine, N,N-diethylaminopropylamine, N,N-dimethylaminoethylamine. This compound may further be selected from alkylamine-substituted heterocyclic compounds such as l-(3-aminopropyl)imidazole and 4-(3-aminopropyl)morpholine, l-(2-aminoethyl)piperidine, 3,3-diamino-N-methyldipropylamine, and 3'3-bisamino(N,N-dimethylpropylamine).

[0080] The compound comprising both an oxygen atom or a nitrogen atom capable of condensing with the acylation agent and a tertiary amine group may also be selected from alkanolamines, including, but not limited to, triethanolamine, trimethanolamine, N,N-dimethylaminopropanol, N,N-dimethylaminoethanol, N,N-diethylaminopropanol, N,N-diethylaminoethanol, N,N-diethylaminobutanol, N,N,N-tris(hydroxyethyl)amine, N,N,N-tris(hydroxymethyl)amine, N,N,N-tris(aminoethyl)amine, N,N-dibutylaminopropylamine and N,N,N'-trimethyl-N'-hydroxyethyl-bisaminoethyl ether, N,N-bis(3-dimethylaminopropyl)-N-isopropanolamine, N-(3-dimethylamino-propyl)-N,N-diisopropanolamine, N'-(3-(Dimethylamino)propyl)-N,N-dimethyl-1,3-propanediamine; 2-(2-dimethylaminoethoxy)ethanol and N,N,N'-trimethylaminoethylethanolamine.

[0081] According to a preferred embodiment, said compound comprising at least one tertiary amine group and at least one group selected from primary amines, secondary amines and alcohols is selected from the following amines of formula (I) or (II): R6 (I) R8 N--X—Ni / rX R6 (II) \--X--[O(CH2)m]„OH r / "

[0082] in which: R6 and R7 are identical or different and represent, independently of each other, an alkyl group having from 1 to 22 carbon atoms; X is an alkylene group having from 1 to 20 carbon atoms; m is an integer between 1 and 5; n is an integer between 0 and 20; and R8 is a hydrogen atom or an alkyl group from Cl to C22.

[0083] When the nitrogen compound comprises an amine of formula (I), R8 is advantageously a hydrogen atom or an alkyl group in Cl to Cl6, preferably an alkyl group in Cl to C10, even more preferably an alkyl group in Cl to C6. R8 can, for example, be chosen from the group consisting of Hydrogen, methyl, ethyl, propyl, butyl and their isomers. Preferably R8 is a hydrogen atom.

[0084] When the nitrogen compound comprises an amine of formula (II), m is preferably equal to 2 or 3, more preferably equal to 2; n is preferably an integer from 0 to 15, more preferably from 0 to 10, even more preferably from 0 to 5. Advantageously, n is equal to 0.

[0085] According to a preferred embodiment, said nitrogen compound is the product of the reaction of the acylation agent substituted by a hydrocarbon group and a diamine of formula (I).

[0086] In this embodiment: - R6 and R7 can represent, independently of each other, an alkyl group in Cl at C16 dc preferably an alkyl group in Cl at C10; R6 and R7 can represent, independently of each other, a methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl group or their isomers. Advantageously, R6 and R7 represent, independently of each other, a Cl to C4 group, preferably a methyl group; - X represents an alkylene group having 1 to 16 carbon atoms, preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, for example 2 to 6 carbon atoms or 2 to 5 carbon atoms. X particularly preferentially represents an ethylene, propylene or butylene group, in particular a propylene group.

[0087] According to a particularly preferred embodiment, the nitrogen compound is the reaction product of a succinic acid derivative substituted by a hydrocarbon group, preferably a polyisobutenyl-succinic anhydride, and an alcohol or an amine also comprising a tertiary amine group, in particular a compound of formula (I) or (II) as described above and more preferably a compound of formula (I).

[0088] According to a first embodiment, the succinic acid derivative substituted with a hydrocarbon group reacts with the amine, which also contains a tertiary amine group, under certain conditions to form a succinimide (closed form). The reaction of the succinic acid derivative and the amine can also, under certain conditions, lead to a succinamide, that is, a compound comprising an amide group and a carboxylic acid group (open form).

[0089] According to a second embodiment, an alcohol also comprising a tertiary amine group reacts with the succinic acid derivative to form an ester also comprising a free carboxyl group -CO2H (open form). Thus, in some embodiments, the nitrogenous compound may be the reaction product of a succinic acid derivative and an amine or an alcohol that is an ester or an amide and which also includes an unreacted carboxyl group -CO2H (open form).

[0090] The quaternary ammonium salt forming the second additive according to the present invention is directly obtained by reaction between the nitrogen compound described above comprising a tertiary amine function and a quatemarizing agent.

[0091] According to a particular embodiment, the quatemarizing agent is chosen from the constituent group of dialkyl sulfates, carboxylic acid esters; alkyl halides, benzyl halides, hydrocarbon carbonates, and hydrocarbon epoxides optionally mixed with an acid, alone or in mixture.

[0092] For fuel applications, it is often desirable to reduce the content of halogens, sulfur and phosphorus-containing compounds.

[0093] Thus, if a quaternary ammonium salt containing such an element is used, it may be advantageous to carry out a subsequent reaction to exchange the counterion. For example, a quaternary ammonium salt formed by reaction with an alkyl halide can then be reacted with sodium hydroxide, and the sodium halide salt removed by filtration.

[0094] The quaternizing agent may include halides such as chloride, iodide, or bromide; hydroxides; sulfonates; bisulfites; alkylsulfates such as dimethyl sulfate; sulfones; phosphates; C1-C12 alkylphosphates; C1-C12 dialkylphosphates; borates; C1-C12 alkylborates; nitrites; nitrates; carbonates; bicarbonates; alkanoates; C1-C12 O,O-dialkyldithiophosphates alone or in mixtures.

[0095] According to a particular embodiment, the quatemarizing agent can be chosen from derivatives of dialkylsulfates such as dimethyl sulfate, N-oxides, sulfones such as propane- and butane-sulfone, alkyl, acyl or aralkyl halides such as methyl and ethyl chloride, benzyl bromide, iodide or chloride, and hydrocarbon carbonates (or alkyl carbonates).

[0096] If the acyl halide is benzyl chloride, the aromatic ring is optionally substituted by one or more alkyl or alkenyl groups.

[0097] The hydrocarbon (alkyl) groups of hydrocarbon carbonates may contain from 1 to 50, from 1 to 20, from 1 to 10, or from 1 to 5 carbon atoms per group. In one embodiment, the hydrocarbon carbonates contain two hydrocarbon groups, which may be identical or different. Examples of hydrocarbon carbonates include dimethyl carbonate and diethyl carbonate.

[0098] According to a preferred embodiment, the quatemarizing agent is chosen from among the hydrocarbon epoxides represented by the following formula (III): in which R9, RIO, RI1 and R12 may be identical or different and independently represent a hydrogen atom or a hydrocarbon group in the C1 to C50 range. By way of non-limiting example, styrene oxide, ethylene oxide, propylene oxide, butylene oxide, stilbene oxide and epoxides in the C1 to C50 range may be cited. Styrene oxide and propylene oxide are particularly preferred.

[0099] Such hydrocarbon epoxides can be used as quaternary oxidizing agents in combination with an acid, for example, acetic acid. Hydrocarbon epoxides can also be used alone as quaternary oxidizing agents, notably without an additional acid. Without being bound by this assumption, it would appear that the presence of the carboxylic acid functional group in the molecule favors the formation of the quaternary ammonium salt. In such an embodiment not using an additional acid, a protic solvent is used for the preparation of the quaternary ammonium salt. By way of example, protic solvents such as water and alcohols (including polyhydric alcohols) can be used alone or in mixtures. Preferred protic solvents have a dielectric constant greater than 9.

[0100] Corresponding quaternary ammonium salts prepared from amides or esters and succinic acid derivatives are described in WO2010 / 132259.

[0101] According to another embodiment, the quaternary agent is chosen from compounds of formula (IV): o (IV) wherein R13 is an alkyl, alkenyl, aryl, or optionally substituted aralkyl group, and R14 is an alkyl, aryl, or alkylaryl group in C1 to C22-

[0102] . The compound of formula (IV) is a carboxylic acid ester capable of reacting with a tertiary amine to form a quaternary ammonium salt. Compounds of formula (IV) are chosen, for example, from carboxylic acid esters having a pKa of 3.5 or less. The compound of formula (IV) is preferably chosen from esters of substituted aromatic carboxylic acids, alpha-hydroxycarboxylic acids, and polycarboxylic acids.

[0103] According to one embodiment, the ester is a substituted aromatic carboxylic acid ester of formula (IV) in which R13 is a substituted aryl group. Preferably, R13 is a substituted aryl group having 6 to 10 carbon atoms, preferably a phenyl or naphthyl group, more preferably a phenyl group. R13 is advantageously substituted by one or more groups selected from the carboalkoxy, nitro, cyano, hydroxy, SRi5, and NRi5Ri6 radicals. Each of the R13 and R13 groups may be a hydrogen atom or an alkyl, alkenyl, aryl, or carboalkoxy group, possibly substituted. Each of the groups R[5 and R[6] represents, advantageously, the hydrogen atom or an alkyl group in Cl at C22 possibly substituted, preferably the hydrogen atom or an alkyl group in Cl at Cl6, more preferably the hydrogen atom or an alkyl group in Cl at C10, even more preferably the hydrogen atom or an alkyl group in Cl at C4. R[5] is preferably a hydrogen atom and R[6] a hydrogen atom or a Cl group at C4.Advantageously, R[5 and both resolve a hydrogen atom.

[0104] According to one embodiment, R13 is an aryl group substituted by one or more groups selected from among the hydroxyl, carboalkoxy, nitro, cyano, and NH2 radicals. R13 may be a polysubstituted aryl group, for example, trihydroxyphenyl. Advantageously, R13 is a monosubstituted aryl group, preferably ortho-substituted. R13 is, for example, substituted by a group selected from the OH, NH2, NO2, or COOMe radicals, preferably OH or NH2. R13 is preferably a hydroxy-aryl group, in particular 2-hydroxyphenyl.

[0105] According to a particular embodiment, R14 is an alkyl or alkylaryl group. R14 may be an alkyl group in the C1 to C6 position, preferably in the C1 to C10 position, advantageously in the C1 to C8 position. R14 may be an alkylaryl group in the C16 position, preferably in the C1 to C10 position, advantageously in the C1 to C8 position. R14 may, for example, be selected from the methyl, ethyl, propyl, butyl, pentyl, benzyl groups or their isomers. Preferably, R14 is a benzyl or methyl group, more preferably methyl.

[0106] A particularly preferred compound is methyl salicylate.

[0107] According to a particular embodiment, the compound of formula (IV) is an ester of an alpha-hydroxycarboxylic acid corresponding to the following formula (V): R17 R18--COOR14 OH in which R17 and RI8 are identical or different and are independently chosen from the group consisting of the hydrogen atom, the alkyl, alkenyl, aryl, or aralkyl groups. Such compounds are described, for example, in the document EP 1254889.

[0108] Examples of compounds of formula (IV) in which R13COO is the residue of an alpha-hydroxycarboxylic acid include methyl-, ethyl-, propyl-, butyl-, pentyl-, hexyl-, phenyl-, benzyl- or allyl-esters of 2-hydroxy-isobutyric acid; methyl-, ethyl-, propyl-, butyl-, pentyl-, hexyl-, benzyl-, phenyl- or allyl-esters of 2-hydroxy-2-methylbutyric acid; methyl-, ethyl-, propyl-, butyl-, pentyl-, hexyl-, benzyl-, phenyl- or allyl-esters of 2-hydroxy-2-ethylbutyric acid; Methyl-, ethyl-, propyl-, butyl-, pentyl-, hexyl-, benzyl-, phenyl-, or allyl- esters of lactic acid and methyl-, ethyl-, propyl-, butyl-, pentyl-, hexyl-, allyl-, benzyl-, or phenyl- esters of glycolic acid. Of the above, the preferred compound is methyl-2-hydroxyisobutyrate.

[0109] According to a particular embodiment, the compound of formula (IV) is an ester of a polycarboxylic acid selected from dicarboxylic acids and carboxylic acids having more than two acidic functions. The carboxylic functions are preferably all in esterified form. Preferred esters are alkyl esters in the Cl to C4 group.

[0110] The compound of formula (IV) may be selected from oxalic acid diesters, phthalic acid diesters, maleic acid diesters, malonic acid diesters, or citric acid diesters. Preferably, the compound of formula (IV) is dimethyl oxalate.

[0111] According to a preferred embodiment, the compound of formula (IV) is a carboxylic acid ester having a pKa less than 3.5. For cases where the compound comprises more than one acid group, reference will be made to the first dissociation constant.

[0112] The compound of formula (IV) may be selected from one or more carboxylic acid esters chosen from oxalic acid, phthalic acid, salicylic acid, maleic acid, malonic acid, citric acid, nitrobenzoic acid, aminobenzoic acid, and 2,4,6-trihydroxybenzoic acid. Preferred compounds of formula (IV) are dimethyl oxalate, methyl 2-nitrobenzoate, and methyl salicylate.

[0113] According to a particularly preferred embodiment, the quaternary ammonium salt used in the invention is formed by reaction of a hydrocarbon epoxide, preferably chosen from those of formula (III) above and more preferably propylene oxide, with the product of the reaction of a polyisobutenyl-succinic anhydride whose polyisobutylene group (PIB) has a number-average molecular weight (Mn) between 700 and 1000 and dimethyl-ami-nopropylamine.

[0114] In a second embodiment, the fuel composition comprises one or more detergent additives selected from among the amido alkyl betaines. These are preferably selected from those of the following formula (VI): O <vi> h As Rf' XN" ' 'NV' RJ R4 Q in which Ri is a C34 Ci hydrocarbon chain, linear or branched, R2 is a hydrogen atom or a C15 Ci hydrocarbon chain, R3 is a C5 Ci hydrocarbon chain and R4 and R5 are identical or different and chosen independently of each other from a hydrogen atom and a hydrocarbon chain in Ci to C1o, preferably in Ci to C6, it being understood that the groups R4 and R5 may contain one or more nitrogen groups and / or may be linked together to form one or more rings.

[0115] Preferably, in formula (VI), Ri is a C8 to C30 hydrocarbon chain, linear or branched, preferably in Ci2 to C24, more preferably in Ci6 to C20.

[0116] Preferably, in formula (VI), R2 is a hydrogen atom or a C1 to C8 hydrocarbon chain, preferably a hydrogen atom. Preferably, in formula (I), R3 is a C1 to C8 hydrocarbon chain, preferably a C2 to C4 chain.

[0117] Preferably, in formula (VI), IC and R5 are identical or different and chosen independently of each other from a hydrogen atom and a hydrocarbon chain in Ci to C6, it being understood that the R4ct R5 groups may contain one or more nitrogen groups and / or may be linked together to form a ring; more preferably R4 and R5 are identical and represent a methyl group or an ethyl group and more preferably a methyl group.

[0118] In a preferred embodiment, alkyl betaine amido is obtained by reacting: (i) a tertiary amine of formula R4R5R'3N: - where R4. R5 are such as defined above for formula (VI), the preferred meanings of these groups for formula (VI) being also preferred for said tertiary amine; - where R'3 denotes a group of formula -R3-N(R2)-CO-Ri, where Rb, R2 and R3 are as defined above for formula (VI), the preferred meanings of these groups for formula (VI) being also preferred for said tertiary amine ; with (ii) acetic acid substituted by at least one halogen, or one of its salts, or one of its ester or amide derivatives.

[0119] Preferably, compound (ii) is acetic acid substituted with a halogen, or a salt of such an acid.

[0120] The salts may include alkali or alkaline earth metals, or ammoniums, including but not limited to sodium, lithium, calcium, potassium, magnesium, triethyl ammonium or triethanol ammonium salts.

[0121] In a preferred embodiment, chloroacetic acid or sodium or potassium chloroacetate salts are used.

[0122] The molar ratio of the amount of carboxylic acid / ester / amide or one of their salts (ii) to the amount of tertiary amine (i) is advantageously within the range of 1:0.1 to 0.1:1.0.

[0123] In a particularly preferred embodiment, alkyl betaine amido is the reaction product: (i) of a tertiary amine substituted with a hydrocarbon group selected from the (C8-C30 alkyl) amidopropyldi(Ci-C4 alkyl)amines and the (C8-C30 alkenyl) amidopropyldi(Ci-C4 alkyl)amines; preferably from the (C8-C30 alkyl) amidopropyldimethylamines and the (C8-C30 alkenyl) amidopropyldimethylamines; with (ii) acetic acid substituted with a halogen, or one of its salts, or one of its ester or amide derivatives; said reaction product being preferably free of non-covalent anionic species.

[0124] Preferably, compound (i) is oleylamido propyl dimethylamine and compound (ii) is sodium chloroacetate.

[0125] The composition according to the invention may include the detergent additive(s) as described above in a preferred content of 5 to 1000 ppm, preferably 10 to 500 ppm, and more preferably 50 to 200 ppm by weight, relative to the total weight of the composition.

[0126] Demulsifying additives (e) According to a preferred embodiment, the fuel composition further comprises at least one demulsifying additive selected from condensation resins of at least one alkyl-phenol with at least one aldehyde, polyoxyalkylened.

[0127] The demulsifying additive(s) are preferably selected from polyoxyalkylated copolymers of: - at least one alkyl-phenol consisting of a phenol ring substituted by one or more alkyl groups having from 1 to 30 carbon atoms, preferably a mono-alkyl-phenol whose alkyl group comprises from 6 to 14 carbon atoms, and - at least one aldehyde having 1 to 4 carbon atoms.

[0128] The alkyl-phenol(s) are preferably chosen from among the para-alkyl-phenols. Nonylphenol is preferred.

[0129] The aldehyde(s) are preferably chosen from formaldehyde, Acetaldehyde, propionaldehyde, butyraldehyde, 2-ethylhexanal, benzaldehyde and mixtures thereof. Formaldehyde is preferred.

[0130] The demulsifying additive(s) are more preferably chosen from among the polyoxyalkylated copolymers of para-nonylphenol with formaldehyde, and more preferably from the polyoxyethylated and polyoxypropylened copolymers of para-nonylphenol with formaldehyde (in particular the compound having CAS number 63428-92-2).

[0131] The composition according to the invention may include the demulsifying additive(s) (e) as described above in a preferred content of 5 to 100 ppm, preferably 8 to 50 ppm, and more preferably 10 to 20 ppm by mass, relative to the total mass of the composition.

[0132] The composition according to the invention advantageously comprises one or more polyoxyalkylated copolymers of para-nonylphenol with formaldehyde at a preferred content of 5 to 100 ppm, preferably 8 to 50 ppm, and more preferably 10 to 20 ppm by mass, relative to the total mass of the composition.

[0133] Other additives: The composition according to the invention may also include one or more additional additives, other than fatty acid methyl and ethyl esters (b) and polysiloxane additives (c) as described above.

[0134] The composition may further include one or more antioxidant agents which may be selected in particular from phenolic antioxidants and amino antioxidants.

[0135] Phenolic antioxidants can be chosen in particular from among alkyl-phenols.

[0136] Preferably, the alkyl-phenol additive(s) are chosen from compounds comprising one or two phenolic ring(s) substituted by one or more alkyl groups in C4 to C1, and more preferably from compounds comprising a phenolic ring substituted by one or more alkyl groups in C4 to C1. The alkyl group(s) in C4 to C1 are more preferably chosen from methyl, ethyl and t-butyl (or tert-butyl) groups.

[0137] The alkyl-phenol additive(s) are more preferably chosen from methyl-t-butyl phenols, dimethyl-t-butyl phenols, ethyl-t-butyl phenols, t-butyl phenols, di-t-butyl phenols, tri-t-butyl phenols, di-t-butyl-methyl phenols, di-t-butyl-di-methyl phenols, trimethyl phenols and mixtures thereof.

[0138] Preferred compounds are selected from 2,6-di-t-butyl-4-methylphenol (BHT), 4,6-di-tert-butyl-2-methylphenol, t-butyl hydroquinone (TBHQ), 2,6- and 2,4-di-t-butylphenol, 2,4-dimethyl-6-t-butylphenol, 2,5-dimethyl-4-t-butylphenol, 2,4,6-tri-t-butylphenol, 2,3,6-trimethylphenol, 2,4,6-trimethylphenol, 4,4'- methylene bis (2,6-di-t-butyl phenol) (CAS No. 1 18-82-1), and their mixtures.

[0139] In a particularly preferred manner, the composition according to the invention contains 2,6-di-t-butyl-4-methylphenol (BHT).

[0140] Amino antioxidants may be selected in particular from aliphatic, cycloaliphatic and aromatic amines. Dicyclohexylamine is particularly preferred.

[0141] The antioxidant agent(s) may be present in a content ranging from 1 to 500 ppm, preferably from 5 to 200 ppm, and more preferably from 10 to 100 ppm by mass, relative to the total mass of the composition.

[0142] The composition may further comprise one or more metal passivating agents, selected from triazole derivatives, alone or in mixture.

[0143] The term "triazole derivatives" refers to all compounds containing a triazole motif, that is, a 5-membered aromatic cyclic motif with two double bonds and three nitrogen atoms. Depending on the position of the nitrogen atoms, a distinction is made between 1,2,3-triazole motifs (called V-triazoles) and 1,2,4-triazole motifs (called S-triazoles). Examples of triazole motifs include benzotriazole and to-lyltriazole.

[0144] The metal passivating agent(s) are preferably chosen from amines substituted with triazole groups, alone or in mixtures. "Triazole group" means any substituent containing a triazole motif as defined above.

[0145] The metal passivating agent(s) are most preferably chosen from N,N-bis(2-ethylhexyl)-[(l,2,4-triazol-l-yl)methyl]amine (CAS 91273-04-0) and N,N'-bis-(2-ethylhexyl)-4-methyl-lH-benzotriazole amine (CAS 80584-90-3), alone or in mixture.

[0146] We can also mention the passivating agents described on page 5 of application US2006 / 0272597.

[0147] The metal passivating agent(s) may be present in a content ranging from 0.2 to 50 ppm, preferably from 0.5 to 25 ppm, and more preferably from 1 to 15 ppm by mass, relative to the total mass of the composition.

[0148] The composition may further include one or more chelating agents (or metal sequestering agents), which may in particular be selected from among amines substituted by N,N'-disalicylidene groups, such as N,N'-disalicylidene 1,2-diaminopropane (DMD).

[0149] The chelating agent(s) may be present in a concentration ranging from 0.1 to 100 ppm, preferably from 0.2 to 50 ppm, and more preferably from 0.5 to 20 ppm by mass, even more preferably from 0.5 to 10 ppm by mass, relative to the total mass of the composition.

[0150] The composition according to the invention may also include one or more other additives commonly used in fuels, different from the additives described above.

[0151] The composition may, typically, include one or more other additives selected from among anti-corrosion agents, dispersants, tracers, biocides, reodorants, friction modifiers, lubrication or smoothness additives, anti-wear agents and / or conductivity modifying agents.

[0152] Uses: The present invention also relates to the use of a fuel composition as described above to power an engine of a vehicle or stationary machine.

[0153] Preferably, the composition according to the invention is used to power a compression-ignition engine or Diesel engine, and more preferably a Diesel engine of a vehicle. The composition according to the invention can in particular be used in the following different vehicles: light vehicles, heavy goods vehicles (trucks of various loads known as "medium duty" and "heavy duty", garbage trucks, buses, coaches, etc.) and non-road vehicles (construction and / or work vehicles, agricultural vehicles such as tractors, railway vehicles such as trains, boats such as ships, barges, etc.).

[0154] According to a preferred embodiment, the composition according to the invention is used to power a compression-ignition engine (or Diesel engine) of a vehicle selected from motor vehicles and non-motor vehicles, preferably a hybrid Diesel engine or a direct injection Diesel engine, more preferably a direct injection Diesel engine and in particular a Common-Rail Injection (CRDI) Diesel engine.

[0155] In this embodiment, the engine is preferably present in a non-motor vehicle, including road vehicles such as, for example, trucks, garbage trucks, buses, and non-road vehicles such as, for example, construction and / or work vehicles, agricultural vehicles, boats.

[0156] The following examples are given as an illustration of the invention, and should not be interpreted in such a way as to limit its scope.

[0157] EXAMPLES The following examples were produced from a paraffinic hydrocarbon fraction (hereinafter fraction A) consisting of a hydrotreated vegetable oil (HVO) whose characteristics are detailed in Table I below:

[0158] Characteristic Method Value Density at 15°C ISO 12185 779.9 kg / m³ Viscosity at 40°C ISO 3104 2.9 mm² / s Cloud Point (PTR)° ASTM D7346 -36°C Filter Plugging Point (TLF) EN 116 -39°C Distillation Profile ISO 3405 Initial Point 216.0°C 5% vol. Point 252.4°C 10% vol. Point 262.1°C 20% vol. Point 269.8°C 30% vol. Point 273.4°C 40% vol. Point 275.7°C 50% vol. Point 277.8°C 60% vol. Point 279.7°C 70% vol. Point 282.1°C 80% vol. Point 285.0°C 90% vol. point 289.2°C 95% vol. point 293.0°C Final point 304.3°C Distilled volume 98.6 ml Residue 1.3 ml Losses 0.1 ml Aromatic compound content EN12916 0% by mass

[0159]

[0160]

[0161] This hydrocarbon fraction consists of 99.9% by mass of paraffins, of which 92.6% isoparaffins (hereafter i-paraffins) and 7.3% by mass of n-paraffins. Its exact composition is detailed in Table II below: Number of C atoms: n-paraffins, i-paraffins, naphthenes, i-naphthenes: 7, 2.35, 0.39; 8, 0.09, 0.20, 0.01; 9, 0.16, 0.43, 0.01 10 0.17 0.80 0.01 11 0.14 0.84 12 0.13 0.99 13 0.15 1.02 14 0.86 1.54 0.01 0.01 15 9.55 0.01 0.05 16 2.43 31.15 0.01 17 14.22 18 0.80 30.71 0.02 19 0.23 0.01 20 0.01 0.31 21 0.03 22 0.06 23 0.02 24 0.01 27 0.08 Total 7.29 92.56 0.03 0.12

[0162] CO, Cl and C2 fuel compositions were prepared by adding the following ingredients to cut A: - Cyclomethicone = decamethylcyclopentasiloxane; and - EMAG: mixture of rapeseed oil fatty acid methyl esters, the characteristics of which are shown in Table III below (fatty acid contents being expressed as a percentage by mass relative to the total mass of fatty acids):

[0163] [Table III C16:0 C18:0 C18:1 C18:2 C18:3 Iodine value Rapeseed methyl ester 5 2.5 59 21 9 111

[0164] The contents of the ingredients in each composition are detailed in Table IV below:

[0165] Compositions CO Cl C2 HVO content (Cut A) (% by mass) 100 93 93 EMAG content (% by mass) - 7 7 Cyclomethicone content (ppm by mass) - - 15

[0166]

[0167]

[0168]

[0169]

[0170]

[0171]

[0172]

[0173] The CO and Cl compositions are comparative and the C2 composition conforms to the invention. Foaming tests: The level of foaming of each of the compositions was determined using the method described in standard NF M 07-075. The test consists of injecting a defined quantity (100 mL) of composition at a constant pressure of 400 millibars into a 250 mL graduated glass test tube. This allows us to determine the foaming of each composition, in terms of the volume of foam formed and the time it takes for the foam to disappear. The results obtained are detailed in Table V below: Composition CO₂ Cl₂ C₂ Foam volume (mL) 50 80 40 Foam disappearance time (s) 2 18 1.8 These results show that the addition of fatty acid methyl esters to the A cut made of HVO leads to a significant increase in foaming, in terms of foam volume and especially in the stability of the foam formed (the time it takes for the foam to disappear is multiplied by 9). The addition of the polysiloxane type additive in a very low concentration (15 ppm by mass) makes it possible to reduce the foaming of the mixture very effectively, to a level which surprisingly is lower than that of cut A.< / vi>

Claims

Claims

1. Fuel composition comprising: a) at least 50% by mass, relative to the total mass of the composition, of one or more paraffinic hydrocarbon fractions consisting of fatty acids and / or hydrogenated fatty acid esters (HEFA); b) at least 2% by mass, relative to the total mass of the composition, of one or more esters chosen from methyl esters and ethyl esters of fatty acids; and c) one or more additives chosen from polysiloxanes and oxyalkylenated polysiloxanes.

2. Composition according to the preceding claim, characterized in that the paraffinic hydrocarbon fraction(s) (a) consist of hydrotreated vegetable oils (HVO).

3. Composition according to any one of the preceding claims, characterized in that the paraffinic hydrocarbon fraction(s) (a) have a paraffin content greater than or equal to 90% by mass, preferably greater than or equal to 95% by mass, and better still greater than or equal to 96% by mass, relative to the total mass of the fraction(s) (a).

4. Composition according to any one of the preceding claims, characterized in that the paraffinic hydrocarbon fraction(s) (a) consist of at least 60% by mass, preferably at least 80% by mass, more preferably at least 85% by mass of paraffins comprising from 12 to 18 carbon atoms, preferably from 14 to 18 carbon atoms, and even more preferably from 15 to 18 carbon atoms.

5. Composition according to any one of the preceding claims, characterized in that the ester(s) (b) are chosen from fatty acid methyl esters.

6. Composition according to the preceding claim, characterized in that it comprises, as esters (b), a mixture of fatty acid methyl esters (EMAG).

7. Composition according to any one of the preceding claims, characterized in that it comprises the ester(s) (b) in a content ranging from 2 to 12% by mass, preferably from 4 to 10% by mass, more preferably from 6 to 8% by mass, and better still from 7% by mass, by relative to the total mass of the composition. ^Claim 8] Composition according to any one of the preceding claims, characterized in that the additive(s) (c) are chosen from polydial-alkylsiloxanes, preferably from polydimethylsiloxanes, more preferably from cyclic polydimethylsiloxanes containing from 4 to 8 silicon atoms, and better still the composition contains decamethylcyclopentasiloxane. ^Claim 9] Composition according to any one of the preceding claims, characterized in that it comprises the additive(s) chosen from polysiloxanes and oxyalkylenated polysiloxanes (c) in a content ranging from 5 to 100 ppm, preferably from 8 to 50 ppm, and more preferably from 10 to 20 ppm by mass, relative to the total mass of the composition.^Claim 10] Composition according to any one of the preceding claims, characterized in that it further comprises one or more detergent additives chosen from quaternary ammonium salts, amido alkyl betaines and their mixtures.^Claim 11] Composition according to the preceding claim, characterized in that it comprises one or more detergent additives chosen from quaternary ammonium salts, preferably chosen from: (dl) quaternized polyisobutylene amines (PIBA); (d2) quaternized polyether amines; and (d3) quaternary ammonium salts obtained by reaction with a quaternization agent of a nitrogen compound comprising a tertiary amine function, this nitrogen compound being the product of the reaction of an acylating agent substituted by a hydrocarbon group and of a compound comprising at least one tertiary amine group and at least one group chosen from primary amines, secondary amines and alcohols; and preferably from quaternary ammonium salts (d3).^Claim 12] Composition according to any one of claims 10 and 11, characterized in that it comprises one or more detergent additives chosen from amido alkyl betaines, preferably chosen from those of the following formula (VI): O. <vi>H FL X ^R. X -0 Rf "y 'nx r2 r4 6 in which R 1 is a linear or branched C 1 to C 34 hydrocarbon chain, R 2 is a hydrogen atom or a C 1 to C 5 hydrocarbon chain, R 3 is a C 1 to C 5 hydrocarbon chain, and R 4 and R 5 are identical or different and chosen independently of each other from a hydrogen atom and a C 1 to C 10 hydrocarbon chain, preferably C 1 to C 6. it being understood that the groups R 4 and R 5 may contain one or more nitrogen groups and / or may be linked together to form one or more rings

13. Composition according to any one of the preceding claims, characterized in that it further comprises at least one de-emulsifying additive chosen from condensation resins of at least one alkyl-phenol with at least one aldehyde, polyoxyalkylenated, and preferably from polyoxyalkylenated copolymers of: - at least one alkyl-phenol consisting of a phenol nucleus substituted by one or more alkyl groups having from 1 to 30 carbon atoms, preferably a monoalkyl-phenol whose alkyl group comprises from 6 to 14 carbon atoms, and - at least one aldehyde having from 1 to 4 carbon atoms.

14. Use of the composition as defined in any one of the preceding claims for powering an engine of a vehicle or stationary machine, preferably a Diesel engine, and more preferably a Diesel engine of a vehicle chosen from motor vehicles and non-motor vehicles including road vehicles such as trucks, garbage trucks, buses; and non-road vehicles such as construction and / or work vehicles, agricultural vehicles, boats.

15. Use according to the preceding claim, for powering a Diesel engine of a vehicle, preferably a hybrid Diesel engine or a direct injection Diesel engine, more preferably a direct injection Diesel engine.< / vi>