EA031490B1 - Additives for improving the resistance to wear and lacquering of vehicle fuels of the gas oil or bio gas oil type - Google Patents

Abstract

The present invention relates to novel anti-lacquering additives for vehicle fuels of the gas oil or bio gas oil type having a sulphur content less than or equal to 500 ppm by mass. These novel additives also improve the lacquering resistance of the higher-grade vehicle fuels of gas oil or bio gas oil type having a sulphur content less than or equal to 500 ppm by mass.

Description

The invention relates to new additives against the formation of a lacquer carbon for motor fuels such as gas oil or biogas oil having a sulfur content less than or equal to 500 ppm ' ¹ by mass. These new additives also improve the resistance to the formation of a varnish-like carbon of high-grade motor fuels such as gas oil or biogas oil, having a sulfur content of less than or equal to 500 ppm ' ¹ by weight.

031490 B1

031490 Bl

The present invention is an additive that provides the ability to limit the formation of soap raids and / or carbon deposits in the internal parts of the injection systems of engines for motor fuels such as (bio) gas oil, that is, in particular, to increase their resistance to the formation of varnish carbon.

Gasoil, or diesel, is a motor fuel for diesel engines (compression ignition engines), including middle distillates with a boiling point between 100 and 500 ° C.

Gas oil can be composed of a mixture of middle distillates of fossil origin and biofuels.

Biofuels are motor fuels derived from organic material (biomass), as opposed to motor fuels derived from fossil resources. As examples of known biofuels, biogas oils (or also called biodiesel) and alcohols can be mentioned.

Biodiesel or biogas oil is an alternative to standard motor fuel for diesel engines. This biofuel is obtained from vegetable or animal oils (including used frying oils) converted into a chemical process called transesterification, in which this oil reacts with alcohol to produce fatty acid esters. Methanol esters of fatty acids (FAME) and ethyl esters of fatty acids (FAEE) are obtained with methanol and ethanol, respectively.

Mixtures of middle distillates of fossil origin and biogas oil are denoted by the letter B, followed by a number indicating the percentage of biogas oil in gas oil. Thus, B99 fuel contains 99% of biogas oil and 1% of middle distillates of fossil origin and B20 contains 20% of biogas oil and 80% of middle distillates of fossil origin, etc.

Therefore, motor fuels based on gasoil type VO, which do not contain oxygen-containing compounds, are distinguished from motor fuels based on biogas oil Bx-type, which contain x% (by volume) ester vegetable oils or fatty acid esters, most often methyl esters (FAME or vome). When only biogas oil is used in engines, motor fuel is designated by the term B100.

In the rest of this application, the term (bio) gas oil is used to refer to motor fuels of the VO or BX type for diesel engines (compression ignition engines).

In many countries, the sulfur content of (bio) gas-oil motor fuels has undergone a very significant reduction due to environmental considerations, in particular, to reduce SO ₂ emissions. For example, in Europe maximum sulfur content in motor fuels automotive gas oil type is currently 10 million by weight of ^-1.

Along with a decrease in sulfur content, methods for producing low-sulfur gas oil or diesel base motor fuels, for example, hydrotreatment methods, also reduce the amount of polycyclic aromatic compounds and polar compounds contained in these gas oil base motor fuels for diesel engines. It is known that the gas oil or diesel motor fuel having a low (less than 100 million ^-1) or very low sulfur content exhibit a decreased ability to lubricate the injection system of the engine, resulting, for example, to premature failure of the fuel injection pump of the engine engine operating time, failure, for example, occurring in high-pressure motor fuel injection systems, such as high-pressure rotary distributors, multi-row pumps and combined injector pumps blocks.

In order to compensate for the loss of compounds that provide the lubricating properties of these motor fuels, numerous lubricant and / or antiwear and / or anti-friction fuel additives have been introduced to the market. Their characteristics are described in general terms in patents EP 915944, EP 839174 and EP 680506.

It is known that diesel engine fuels on the market must meet national or supranational specifications (for example, the EN 590 standard for diesel engine fuels in the European Union). For industrial motor fuels there is no legal obligation to introduce so-called additives to improve performance (chemical compounds introduced into fuels to improve their properties, such as detergents, antifriction additives, anti-corrosion additives, antifoaming additives, and additives to improve low-temperature characteristics); Oil companies and sellers are free to choose whether or not to add additives to their motor fuels. From an industrial point of view, in the field of fuel distribution, a distinction is made between standard or basic fuels, with low or no additive content, and higher grade fuels in which one or more additives are introduced to improve their technical characteristics (beyond regulated parameters) .

Within the meaning of the present invention, under a high-grade motor fuel type gas oil or gas oil is meant any biogazoylya biogazoylevoe or motor fuel, to which have been added at least 50 million by weight of ^-1 reduces deposition and / or detergents and / or dispersants.

- 1 031490

Description of the drawings

FIG. 1 is a photograph of a high-pressure direct-injection diesel nozzle;

FIG. 2 is a photograph of a direct-injection diesel engine nozzle needle contaminated with sediments such as soap and / or soot (varnish-like carbon);

FIG. 3 is a photograph of the nozzle of a direct-injection diesel engine contaminated with sediments such as coke;

FIG. 4 is a photograph of a direct-injection diesel engine nozzle needle contaminated with sediments such as soap and / or soot (varnish-like carbon).

As shown in FIG. 1 and 2, it was found that during the application of certain high-grade (bio) gas-oil motor fuels, deposits 1 occur on the needles 2 nozzles 3 of diesel engine injection systems, in particular, such as from Euro-3 to Euro-6. Thus, the use of additives such as anti-wear and / or anti-friction, and / or coke-deposition-preventing additives, sometimes showed poor, or even very unsatisfactory, resistance to the formation of varnish. This leads to the formation of deposits 1, generally defined by the term lacquer-like carbon, which will be used later, or the abbreviation IDID (internal deposits in a diesel injector).

Within the meaning of the present invention, the phenomenon of the formation of a varnish is not related to deposits that are present outside the system 5 or 5 'injection (Fig. 1 and 3), and which are associated with coking, which leads to contamination and partial or complete blocking of the injection nozzles 4 or 4 '(coking or clogging of the nozzle).

The formation of lacquerous carbon and coking are two phenomena that clearly distinguish the causes of these deposits;

conditions of occurrence of these deposits and the place where these deposits form.

Coking is a phenomenon that occurs only downstream of the diesel injection system.

As shown in FIG. 3, the formed deposits 5 'are characterized by the fact that they are formed as a result of the pyrolysis of hydrocarbons entering the combustion chamber and have the appearance of carbon deposits. In the case of high-pressure direct injection diesel engines, it was found that the tendency to coking is much less pronounced. This coking is modeled in the CEC F098-08 DW10B standard test, in particular, when the motor fuel tested is contaminated with zinc metal.

In the case of engines with pre-chamber injection, the injection of motor fuel does not occur directly into the combustion chamber, as in the case of engines with direct injection. As described, for example, in patent document US 4,604,102, in front of the combustion chamber there is a pre-chamber into which fuel is injected. The pressure and temperature in the prechamber are lower than in the combustion chamber of direct injection engines.

Under these conditions, the pyrolysis of motor fuel creates carbonaceous particles, which are deposited on the surface of the nozzles 4 'of the injectors (throttled diesel nozzle), and clog the holes 6 of the nozzles 4' (Fig. 3). There is a risk of carbon deposits (coking) only on the surfaces of the nozzle 4 'exposed to gaseous products of combustion. In terms of performance, the coking phenomenon causes a loss of engine power.

The formation of a varnish-like carbon deposit is a phenomenon that occurs only in diesel engines with direct injection, and is manifested only upstream relative to the combustion chamber, that is, in the injection system.

As shown in FIG. 1 and 2, the nozzles of 3 diesel engines with direct injection include a needle 2, the raising of which allows precise control of the amount of fuel injected under high pressure directly into the combustion chamber.

The formation of varnish-like soot leads to the formation of deposits 1, which are formed especially at the level of the needles 2 of the nozzles 3 (Fig. 1 and 2). The phenomenon of lacquer varnish is associated with the formation of soap and / or carbon deposits in the internal parts of the injection systems of engines for (bio) gas oil type fuels. The lacquer deposit 1 can be localized at the end of 4 needles 2 nozzles 3, both on the head and on the case of needles 2 of the engine fuel injection system, but also throughout the needle lift control system (valves not shown) of the injection system. This phenomenon is particularly noticeable in the case of engines using high-grade (bio) gas oil motor fuels. When these deposits are present in large quantities, the mobility of the needle 2 of the nozzles 3 contaminated with these deposits 1 deteriorates. This phenomenon of varnish carbon can ultimately lead to a decrease in the flow rate of the injected motor fuel and therefore loss of engine power.

In addition, unlike coking, the formation of a varnish-like soot can also cause

- 2 031490 engine noise amplification and sometimes starting problems. Indeed, parts of needles 2 contaminated with deposits of soap and / or soot 1 can stick to the inner walls of nozzle 3. Then needles 2 are blocked and the fuel can no longer pass through them.

As a rule, a distinction is made between 2 types of deposits of the lacquer-like type:

1) deposits, which are rather whitish and powdery; analyzes have found that these deposits consist essentially of sodium (for example, sodium carboxylates) and / or calcium soaps (type 1 deposits);

2) organic deposits, similar to painted lacquer films, localized on the body of the needle (type 2 deposits).

As for type 1 deposits, there are numerous possible sources of sodium in Bx-type biogas oil motor fuels:

vegetable oil transesterification catalysts for the preparation of fatty acid esters such as methyl or ethyl esters, such as sodium formate;

another possible source of sodium may be corrosion inhibitors, used when petroleum products are transported through certain pipelines, such as sodium nitrite;

Finally, accidental external pollution, for example, with water or with air, may cause sodium to enter motor fuels (sodium is a very common element).

There are many possible sources of acids in Bx-type motor fuels, for example: residual acids in biofuels (see standard EN14214, which regulates the maximum allowable level of acid content);

corrosion inhibitors used in the transportation of petroleum products through specific pipelines, such as DDSA (dodecenyl anhydride), or HDSA (hexadecenyl anhydride), or some of their functional derivatives, such as acids.

In relation to organic sediments of type 2, some publications indicate that they may result from, in particular, reactions between reducing deposits of additives / dispersants used to prevent coking (for example, detergents of the PIBSI type (polyisobutylene sucminimide), which are polyamine derivatives) , and acids (which would be present, among other things, as contaminants of fatty acid esters in biogas oil).

In the publication SAE (Society of Automotive Engineers) 880493, Reduced Injection Needle Mobility Caused by Lacquer Deposits from Sunflower Oil, the authors of M.Ziejewski and HJGoetter describe the phenomenon of the formation of varnish carbon and its varnish. adverse effects on the operation of engines operating on sunflower oil as a motor fuel.

SAE Publication 2008-01-0926, Investigation of Diesel Injector Deposits, study by the formation and prevention of internal deposits in diesel injectors, by J. Ulmann, M. Geduldig, H.Stutzenberger (Robert Bosch GmbH) and R. Caprotti, G.Balfour (Infineum) also describe reactions between acids and scaling agents / dispersants to explain type 2 deposits.

In addition, SAE International, 2010-01-2242, Internal Injector Deposits for High-Pressure Common Rail Diesel Engines, by S. Schwab, J. Bennett, S. Dell, J. Galante-Fox, A. Kulinowski and Keith T. Miller clarify that the internal parts of the nozzles are usually covered with a slightly colored deposit that is visible to the naked eye. Their analyzes made it possible to determine that it is mainly composed of sodium salts of alkenyl (hexadecenyl or dodecenyl) succinic acids; with the origin of sodium from dehydrating reagents, from alkaline solutions used for cleaning, from water at the bottom of tanks or from sea water, and succinic dibasic acids, used as corrosion inhibitors or present in the compositions of multifunctional additives. After formation, these salts are insoluble in low-sulfur diesel fuels, and since they are in the form of fine particles, they can pass through fuel oil filters and settle down inside the injectors. This publication describes the development of an engine test method that allows the reproduction of sediment formation. This publication emphasizes that deposits form only dibasic acids, unlike monocarboxylic acids or neutral esters of organic acids.

In the publication SAE International, 2010-01-2250, Deposit Control in Modern Diesel Fuel Inj ection System (Control of sediments in the modern system of injection of diesel fuel), the authors R.Caprotti, N. Bhatti and G.Balfour also explore the internal deposits of the same type in the injectors and argue that the appearance of deposits is not specifically related to one type of motor fuel (VO, or containing FAME (Bx)), nor to vehicles of the same type (cars or heavy trucks) equipped with modern engines (with a common fuel line ). They demonstrate those

- 3 031490 Characteristics of a new composition of a reducing additive / dispersant deposit, effective for deposits of all types (coking and varnish).

The present invention provides additives with prophylactic and restorative effects, which provide the ability to limit sediments of soap and / or soot in the inner parts of injection systems, that is, to improve resistance to the phenomenon of formation of varnish in engines using motor fuels such as high-grade (bio) gas oil and / or (bio) diesel engine, the sulfur content of which is less than or equal to 500 ^-1 million by weight, and which comprise at least 50 ^-1 million by weight of additives such as abbreviated additive (s), and / or detergent additives, and / or dispersant (s). Therefore, such additives prevent the formation of these deposits (preventive action), and, when they are formed, allow you to remove them, performing the function of the nozzle cleaner (reducing effect).

These problems of resistance to the formation of varnish-like carbon deposits of motor fuels of the (bio) gas oil type are resolved by using at least one additive that contains at least 50% by weight of the partial polyol ester (s), and these polyol esters include x ester structural units, y hydroxylated structural units and z ether etheric units, with x, y and z representing integers so that x varies from 1 to 10, y changes from 1 to 10 and z varies from 0 to 6, preferably x change It varies from 1 to 10, y varies from 3 to 10, and z varies from 0 to 6.

The synthesis of partial polyol esters is known per se; for example, they can be obtained by esterification from fatty (acid) acids (from) and linear and / or branched polyols, optionally including (hetero) cycles of 5-6 atoms, bearing hydroxyl functional groups. The product (s) formed (es) in this esterification reaction has (have) such a distribution of ester structural units, hydroxylated structural units and ether etheric structural units, that x varies from 1 to 4, y changes from 1 to 7 and z changes from 1 to 3. As a rule, the synthesis of this type leads to a mixture of complex mono-, di-, tri-, and, optionally, tetraesters, as well as small amounts of fatty acid (s) (from) and polyols that have not reacted.

According to one embodiment, polyol esters are obtained by esterifying fatty acid (s) with linear and / or branched polyols, optionally containing heterocycles of 4-5 carbon atoms and an oxygen atom, bearing hydroxyl functional groups.

In the framework of the present invention, the polyols will be selected from linear polyols comprising more than three hydroxyl functional groups, and polyols containing at least one (hetero) cycle of 5-6 atoms, preferably heterocycles of 4-5 carbon atoms and an oxygen atom, optionally having hydroxyl groups as substituents, and these polyols can be applied individually or in a mixture.

In the rest of this discussion, these polyols in the compositions referred to below are denoted as R.

Among the polyols R, polyols with linear or branched hydrocarbon chains include at least four structural units represented by the following formula (I) n- (OCH ₂ ) p- (CHOH) q- (CH ₂ OH) (I)

Moreover, p and q are integers, and p is equal to or greater than 0, q is more than 2, and these numbers can not exceed 10.

Among the polyols R, polyols with linear or branched hydrocarbon chains include at least four structural units represented by the following formula (II)

H- (OCH ₂ ) _p - (CR1R2) _q - (CH ₂ OH) (II)

Moreover, p and q are integers, and p is equal to or greater than 0, q is more than 1, and these numbers can not exceed 5, R1 and R2 are the same or different and represent either a hydrogen atom or CH ₃ - or C ₂ H ₅ -group, or BUT-CH ₂ -group.

Among the polyols R, some include at least one (hetero) cycle of 4-5 carbon atoms and an oxygen atom, optionally having hydroxyl groups as substituents, and corresponding to the general formula (III) below:

O / \ HO-CH ₂ - (CHOH) s- [HC- (CHOH) t] (III) with s and t representing integers, and when s is 1, t is 3, and when s is zero, t equals 4.

Among the polyols R, some include at least two heterocycles with 4-5 carbon atoms and an oxygen atom connected to form an acetal bond between the hydroxyl functional group of each cycle, and these heterocycles optionally have hydroxyl functional groups as substituents.

The polyols are preferably selected from the group including erythritol, xylitol, D-arabitol, L-arabitol, ribite, sorbitol, maltitol, isomaltite, lactitol, sorbitan, volemit, mannitol, pentaerythritol, 2-hydroxymethyl1,3-propandiol, 1,1,1 - three (hydroxymethyl) ethane, trimethylolpropane and carbohydrates, such as sucrose, fruc

- 4 031490 tons, maltose, glucose, and sucrose, preferably sorbitan.

According to one preferred embodiment, the partial polyol esters are selected from partial sorbitan esters, preferably sorbitan monooleate, used alone or in a mixture.

The fatty acids from which the esters are formed according to the invention can be selected from fatty acids, the chain length of which varies from 10 to 24 carbon atoms, and / or at least one dicarboxylic acid substituted by at least one polymer, for example poly (i a) butene containing from 8 to 100 carbon atoms. Preferably, they are chosen, in the case of monobasic acids, from stearic, isostearic, linolenic, oleic, linoleic, behenic, arachidonic, ricinoleic, palmitic, myristic, lauric and capric acids, and mixtures thereof, and, in the case of dibasic acids, from alkyl or alkenylsuccinic, alkyl- or alkenylmaleic acid.

Fatty acids can be products of transesterification or saponification of vegetable oils and / or animal fats. Preferred vegetable oils and / or animal fats are selected according to the concentration of oleic acid in them. May be given a link, for example, on the table. 6.21 in Chapter 6 of the publication Carburants & Moteurs (Fuels and Motors) by J.C. Guibet and E. Faure, 2007 edition, which lists the compositions of several vegetable oils and animal fats.

Fatty acids can also be derived from tall oil fatty acids, which include most fatty acids, typically in amounts greater than or equal to 90% by weight, as well as in small quantities resin acids and non-saponifiers, that is, in quantities mostly less than 10 %

Preferred additives according to the invention capable of increasing the stability of high grade (bio) diesel motor fuels to the formation of a varnish, contain sorbitan esters.

Other preferred additives include at least 50% by weight of the mono / or diester (s) of isobutylene succinic acid and polyols (s), according to one of formulas I-III.

Other preferred additives include at least 50% by weight of the mono-carbon (s) (or diester) of monocarboxylic acids with 12-24 carbon atoms and polyols according to one of formulas I-III.

The invention also relates to an additive composition for (bio) gas oil motor fuels containing at least one additive to increase resistance to the formation of a varnish-like carbon deposit, as previously defined, and at least one or more other functional additives, such as reducing deposits / dispersants, antioxidants, combustion activators, corrosion inhibitors, additives to improve low-temperature characteristics (improving the cloud point, sedimentation rate, filterability and / or low temperature atur fluidity), coloring additives, demulsifiers, antioxidant additives, antifoaming agents, cetane number improvers, compatibility agents, lubricant additives, anti-wear additives and / or antifriction additives, and one or more solvents or cosolvents.

The use of additives according to the invention makes it possible to increase the resistance to the formation of a varnish-like carbon on the level of fuel injectors, and thereby limit the formation (deposition) of soap and / or carbon in the presence of additives such as scaling additives and / or detergents, and / or dispersants. The use of these additives in (bio) gas oil motor fuels can reduce clogging speed and damage to the fuel injection or injection system, in particular, at the fuel pump.

(Bio) gas oil motor fuels (liquid fuels for compression ignition engines) may include middle distillates having a boiling point between 100 and 500 ° C; their ICT temperature at the onset of crystallization is often higher or equal to -20 ° C, typically between -15 ° C and + 10 ° C. These distillates are mixtures of base fuels that can be selected, for example, from distillates obtained by direct distillation of gasoline or crude hydrocarbons, vacuum distillates, hydrotreated distillates, distillates formed by catalytic cracking and / or hydrocracking of vacuum distillates, distillates obtained from conversion processes such as ARDS (desulfurization of atmospheric distillation residues), and / or light cracking to reduce viscosity.

(Bio) gasoil motor fuels may also contain light shoulder straps, such as gasolines obtained by distillation, from catalytic or thermal cracking, plants for alkylation, isomerization, desulfurization, and steam cracking.

In addition, (bio) gas oil motor fuels may contain new sources of distillates, among which, in particular, may be mentioned:

heavier shoulder straps formed in cracking and light cracking processes, with high concentrations of heavy paraffins containing more than 18 carbon atoms, synthetic distillates obtained by gas conversion, such as those formed from the Schera-Tropsch Fe-5 process, synthetic distillates obtained by treating biomass vegetable and / or animal origin, in particular, such as renewable NexBTL fuel, individually or in a mixture, coking gas oils, alcohols, such as methanol, ethanol, butanols, ethers, (MTBE, ETBE, etc. .), mainly used in mixtures with gasoline motor fuels, but sometimes with heavier motor fuels such as gas oil, vegetable and / or animal oils and / or their esters, such as methyl or ethyl esters of vegetable oils or fatty acids (VOME , FAME, VOEE, FAEE), vegetable and / or animal oils subjected to hydrotreating and / or hydrocracking, and / or hydrodeoxygenation (HDO),

These new motor fuels and base fuels can be used individually or mixed with standard petroleum middle distillates as the base (output) motor (s) fuel (liv); as a rule, they contain paraffins with a chain length greater than or equal to 10 carbon atoms, preferably from C ₁₄ to C ₃₀ .

In the present invention, (bio) gas oil motor fuels have a sulfur content of less than or equal to 500 ^-1 million by weight, preferably less than or equal to 100 million by weight of ^-1, and the content can be reduced to a value less than or equal 50 million ^{- 1} by weight, or even less than or equal to 10 ^-1 million by weight (this occurs in diesel fuels for modern vehicles for which the sulfur content according to the current moment in time, the European standard EN 590 must be less than or equal to ^-1 at 10 million mass).

Additives that provide resistance to the formation of a varnish, that is, the formation of soap and / or carbon in the internal parts of the engine injection systems, for (bio) gas oil motor fuels according to the invention can be introduced into motor fuels up to 10% by weight. Concentration of partial esters according to the invention in the finished motor fuel is preferably between 20 and 1000 ^-1 million by weight, and preferably between 30 and 200 million by weight of ^-1, i.e., ^-1 in ppm by weight relative to the total weight of motor fuel with additives.

According to one embodiment, the composition of high-grade (bio) gas oil comprise at least 20 ^-1 million by weight of at least one additive of the invention and, optionally, at least one or more other functional additives. The concentration of additives in the composition according to the invention, i.e., the concentration of the partial ester, may preferably vary from 20 to 1000 ^-1 million by weight, and more preferably from 30 to 200 ^-1 million by weight (weight ratio).

Among other functional additives, additives for increasing the resistance to the formation of a lacquer-like carbon can be used individually or in a mixture with reducing deposits of additives and / or detergents, and / or dispersants, antioxidants, combustion activators, corrosion inhibitors, additives to improve low-temperature characteristics ( cloud temperature, sedimentation rate, filterability and / or low-temperature fluidity), coloring additives, demulsifiers, antioxidant n cuttings, antifoaming agents, cetane number enhancers, anti-wear and lubricant additives, and / or antifriction additives, co-solvents, agents to improve compatibility, etc.

Other (s) functional (s) additive (s) can (gut) be selected (s) from additives to stimulate combustion;

for motor fuels such as gasoil, cetane number raising additives may be mentioned, in particular (but not limited to) selected from alkyl nitrates, preferably 2-ethylhexyl nitrate, aryl peroxides, preferably benzyl peroxide, and alkyl peroxides, preferably di-tert-butyl peroxide; for gasoline-type motor fuels, additives to increase the octane number may be mentioned; for such fuels as fuel for residential heating, heavy fuel, fuel for marine engines, tricarbonyl methylcyclopentadienyl manganese (MMT) may be mentioned;

antioxidant additives, such as aliphatic, aromatic amines, sterically hindered phenols, such as BHT (butylhydroxytoluene), BHQ (di-tert-butylbenzohydroquinone);

emulsion breakers, or demulsifiers;

antistatic agents or conduction enhancing additives;

coloring additives;

antifoaming agents, in particular (but not limited to) selected, for example, from polysiloxanes, oxyalkylated polysiloxanes, and fatty acid amides derived from vegetable or animal oils; examples of such additives are given in patent documents EP 861182, EP 663000, EP 736590;

detergents or dispersants, in particular (but not limited to) selected from the group,

- 6 031490 consisting of amines, succinimides, succinamides, alkenylsucimimides, polyalkylamines, polyalkylpolyamines, polyether amines, Mannich bases;

examples of such additives are given in patent document EP 938535;

anti-corrosion additives such as ammonium salts of carboxylic acids;

chelating agents and / or metal-binding agents, such as triazoles, disalicylidenealkylenediamines, and in particular ^ # bis (salicylidene) -1,3-propanediamine;

additives to improve the low-temperature characteristics and, in particular, additives to improve the cloud point, in particular (but without limitation) selected from the group consisting of long-chain ternary copolymers of olefin, (meth) acrylic ester and maleimide ester, and fumaric esters and maleic acid. Examples of such additives are given in patent documents EP 71513, EP 100248, FR 2528051, FR 2528423, EP1 12195, EP 172758, EP 271385, EP 291367; anti-sedimentation additives and / or dispersing agents for paraffins, in particular (but without limitation) selected from the group consisting of copolymers of (meth) acrylic acid and alkyl (meth) acrylates amidated with polyamine, alkenylsuccinimides, polyamine derivatives, phthalamic acid and double-chain fatty derivatives acids; alkylphenol-aldehyde resins; examples of such additives are given in patent documents EP 261959, EP 593331, EP 674689, EP 327423, EP 512889, EP 832182; US 2005/0223631; US 5998530; WO 93/14178;

multifunctional additives for suitability for low-temperature operation, selected in particular from the group consisting of polymers based on olefin and alkenyl nitrates, such as described in patent document EP 573490;

other low temperature performance and filterability (CFI) additives, such as EVA (ethylene vinyl acetate) and EVP (ethylene vinyl propionate) copolymers;

passivator metals, such as triazoles, alkylated benzotriazoles;

acidity neutralizers such as cyclic alkylamines;

markers, in particular markers regulated by directives, for example dyes specific for each type of motor fuel or fuel.

fragrances or means of masking odors, such as described in patent document EP 1591514;

lubricant additives, anti-wear additives and / or anti-friction additives, other than those described above, in particular (but not limited to) selected from the group consisting of fatty acids and their ester or amide derivatives, in particular glycerol monooleate, and mono- and polycyclic carboxylic acids; examples of such additives are given in the following patent documents: EP 680506, EP 860494, WO 98/04656, EP 915944, FR2 772783, FR 2772784.

Generally, other optional additives are added in amounts ranging from 50 to 1500 million by weight of ^-1, i.e., ^-1 in ppm by weight relative to the total weight of motor fuel with additives.

These additives can be introduced into the fuel by any known method; as an example, the additive or mixture of additives can be introduced in the form of a concentrate, including additive (s) and a solvent compatible with (bio) diesel fuel, the additive being dispersed or dissolved in a solvent. Such concentrates typically contain from 20 to 95% by weight of solvents.

A qualified specialist in this field of technology can easily select the concentration of additives according to the invention depending on any dilution of the additive in a solvent, the possible presence of other components, such as those from the esterification reaction, and / or other functional additives introduced into the final motor fuel.

Solvents are organic solvents that, as a rule, contain hydrocarbon solvents. As an example of solvents, petroleum fractions such as naphtha, kerosene, heating oil can be mentioned; aliphatic and / or aromatic hydrocarbons, such as hexane, pentane, decane, pentadecane, toluene, xylene, and / or ethylbenzene, and alkoxyalkanols, such as 2-butoxyethanol, and / or mixtures of hydrocarbons, such as mixtures of industrial solvents, such as Solvarex 10, Solvarex LN, Solvent Naphtha, Shellsol AB, Shellsol D., Solvesso 150, Solvesso 150 ND, Solvesso 200, Exxsol, ISOPAR, and, optionally, co-solvents or compatibilizers, such as 2-ethylhexanol, decanol, isodecanol, and / or isotridecanol.

The invention relates to the use of at least one additive composition according to the invention, introduced into motor fuel such as high-grade (bio) gas oil, to increase the resistance to the formation of varnish, that is, pollution on the head and / or on the body of the needles of the fuel injection system, but also in general, the systems for regulating the lift of the needle (valves) of the injection system, in particular, for engines equipped with high-pressure direct-injection systems with which most vehicles are equipped, tvetstvuyuschih standard Euro 3 and later instructions.

According to one particular embodiment, the subject matter of the present invention also relates to the use of a composition (bio) gas oil motor fuel, as described above, to limit the deposition of soap and / or carbon deposits in the inner parts of the injection systems of engines

- 7 031490 using the specified composition, preferably engines with direct injection, in particular engines with high-pressure direct injection.

Subject of the present invention also relates to a method of a soap plaque deposits control and / or fouling of inner parts of the engine fuel injection system for (bio) gas oil engine fuels (diesel engine) having a sulfur content of less than or equal to 500 million by weight of ^-1, said method includes burning in the specified engine composition (bio) gas oil motor fuel, as defined above. The method is preferably applicable to engines with direct injection, in particular, to engines with high-pressure direct injection.

Thus, the method according to the invention eliminates and prevents the formation of deposits of soap and / or sludge in the internal parts of the engine injection system in order to maintain the specified engine in a clean state.

The method according to the present invention advantageously removes deposits of soap and / or soot in the internal parts of the engine injection system, exhibiting a regenerating effect, cleansing the engine.

Examples

In order to test the performance characteristics of these additives according to the invention, the authors of the present invention also developed a new method that is reliable and error resistant to assess the sensitivity of (bio) gas oil motor fuels, in particular high-grade fuels, to the formation of varnish. This method, unlike the methods described in the publications cited above, is not a laboratory method, but is based on engine tests, and therefore is of industrial interest, and allows you to quantify the effectiveness of additives or additive compositions in relation to varnish. A method for measuring varnish-like carbon developed by the authors of the present invention is detailed below:

The engine used is a four-cylinder 16-valve diesel engine with a high-pressure common fuel line, with a cylinder capacity of 1500 cm ³ and a power of 80 hp: the fuel injection pressure is controlled in the high-pressure part of the pump.

The power measurement is carried out over a period of 40 hours at 4000 rpm; the position of the nozzle in the chamber was reduced by 1 mm relative to its normal position, which, on the one hand, contributes to enhancing the effects of thermal energy of combustion, and, on the other hand, makes the nozzle close to the combustion chamber.

The flow rate of the injected motor fuel is adjusted so as to obtain an exhaust gas temperature of 750 ° C at the beginning of the test.

The injection advance increased by 1.5 ° the rotation of the crankshaft relative to the nominal setting (with a change from + 12.5 ° to + 14 ° rotation of the crankshaft), again with the aim of increasing the thermal stresses to which the nozzle nozzle is subjected.

Finally, to enhance the effects that motor fuel is exposed to, the injection pressure is increased by 10 MPa relative to the nominal pressure (i.e., a change from 140 to 150 MPa), and the temperature is adjusted to 65 ° C at the inlet to the high-pressure pump.

The technology used for the injectors requires a high degree of fuel return, which stimulates the degradation of motor fuel, since it can be pumped in several cycles through a high-pressure pump and a high-pressure chamber before it is injected into the combustion chamber.

A variant of the method was also developed for testing the cleaning effect (i.e., cleaning of type 1 and / or type 2 deposits). It is based on the previous method, but is divided into two 20-hour periods:

For the first 20 hours, high-grade gas oil B7 (containing a PIBSI detergent additive and an acid product), known for its tendency to cause the formation of a varnish-like carbon, is used. After 20 hours, two of the four nozzles are dismantled, an assessment is made to check the quality of the deposits present, and then replaced by two new nozzles.

Over the next 20 hours of testing, use the evaluated product. At the end of the test (40 hours in total), the nozzles are removed and evaluated.

At the end of the test, three sets of two nozzles are available:

Kit 1: nozzles that have been exposed to 20-hour high-grade motor fuel, known for its tendency to cause the formation of varnish.

Kit 2: nozzles that have been exposed to a 20-hour exposure known for their tendency to cause the formation of a varnish-like deposit of high-grade motor fuel + a 20-hour exposure to the product being evaluated.

Kit 3: nozzles subjected to a 20-hour exposure to the product being evaluated.

Expression of results

To ensure the reliability of the results, various parameters are monitored during the test: power, torque and fuel consumption show whether the nozzle is contaminated or its operation is disturbed due to the formation of deposits, since the operating mode is

- 8 031490 the same throughout the test.

The characteristic temperatures of various fluids (coolant, motor fuel, oil) make it possible to evaluate the reliability of the monitored test conditions. The temperature of the engine fuel is regulated to 65 ° C at the inlet of the pump, and the temperature of the coolant is controlled to 90 ° C at the outlet of the engine.

Smoke values allow you to track the timing of the burning at the beginning of the test (the target smoke number of the filter is 3FSN), and to ensure that it is reproducible from one test to another.

The nozzles are dismantled at the end of the test in order to check and evaluate the deposits formed along the needles. The procedure adopted for assessing needles is as follows:

The scale of scoring varies from -2.5 (for abundant deposits) to 10 (for a new needle without any deposits). The final score is the weighted average of the estimates for all evaluated needle surfaces, that is, the conical part and the body, or the cylindrical part of the needle.

Thus, the cylindrical zone (immediately following the conical part) represents 68% of the total needle assessment, and the conical area represents 32% of the total needle assessment; for ease of evaluation, each of these zones is divided by 4. In FIG. The 4 shown percentages correspond to one-fourth of the surface area of the needles: therefore, the weight treatment of the entire surface area gives 17x4 = 68%.

The product performance threshold was determined for this evaluation procedure: result <4 = unsatisfactory, result> 4 = satisfactory.

The following examples illustrate the invention without limiting it.

Example 1 - measuring the resistance to the formation of varnish

According to the above described procedure for measuring the resistance to the formation of a lacquer varnish, the performance characteristics of several additive compositions introduced into the gas oil matrix, indicative of the French market (B7 = gas oil produced in France, containing 7% FAME (methyl ester of fatty acid) and corresponding to the standard EN 590). Details regarding each tested composition of motor fuel, as well as the results obtained, are shown in Table. one.

Listed in table. 1 quantities are quantities by weight (mass ratio).

Table 1

Test No. BUT AT WITH D E F Motorized fuel Washing AT 7 AT 7 AT 7 AT 7 AT 7 AT 7 additive to 330 170 170 170 330 diesel fuel million ^-1 million ^-1 million ^-1 million ^-1 million ^-1 PIBSI type Mixture of fatty acids, mainly oleic acid, with an acid number of 180 mg KOH / g ___ 200 ppm ^-1 ___ ___ ___ ___ Monooleate 200 100 sorbitan million ^-1 million ^-1 Pentaerythritol mono- and dioleate ___ ___ ___ 200 ppm ^-1 ___ ___ Scoring assessment 8.7 -one 7.2 4.1 7.2 5, 2 sediments type 1 Scoring type 2 deposits 7.1 -one 6, 9 6, 7 6, 0 6.2 Generalized point 8.2 -one 7.2 50 6, 4 5, 9 assessment

- 9 031490

These tests clearly demonstrate the effectiveness of the products according to the invention in preventing and limiting the formation of deposits such as soot or soap scum (the “keep clean” action), since the needle assessment results at the end of the tests are much better than the results obtained when the motor fuel contains only an additive PIBSI, capable of forming soap raids on the needles of the nozzles.

Example 2 - Measuring Resistance to Lacquer Carbon Formation

According to the above described procedure for measuring the resistance to the formation of a lacquer-like carbon deposit in its purification variant, the performance characteristics of several additive compositions introduced into the gas oil matrix, indicative of the French market, are evaluated (B7 = gas oil produced in France containing 7% FAME (methyl ester of fatty acid ) and conforms to EN 590). Details regarding each tested composition of motor fuel, as well as the results obtained, are shown in Table. 2. It should be noted that tests G, G 'and G correspond to the same test, with G corresponding to the result for a set of 1 nozzles, G' corresponding to the result for a set of 2 nozzles, and G corresponding to the result for a set of 3 nozzles.

Listed in table. 2 quantities are quantities by weight (mass ratio).

table 2

Test No. G G ' G Motor fuel AT 7 AT 7 AT 7 Diesel fuel additive PIBSI type 33 0000000 ^-1 300, then 170 million ^-1 17 0000000 ^-1 A mixture of fatty acids, mainly oleic acid, with an acid number of 180 mg KOH / g 2 00M ^-1 200, then 0 million ^-1 ___ Sorbitan monooleate ___ 0, then 2 00M ^-1 2 00M ^-1 Scoring sediment type 1 2, 6 3.7 6, 2 Scoring sediment type 2 1.4 3.7 6, 5 Generalized score 18 3.7 6, 4

These results demonstrate the effectiveness of the cleaning action (cleaning effect) of the products according to the invention, that is, in removing deposits such as soot or soap deposits already formed on the needles, since the evaluation of the set of nozzles G 'gives better results than the assessment of the set of nozzles G (significant cleaning of the needle started), and also confirms their prophylactic efficacy, maintenance in a clean state), since the assessment of the set of nozzles G is still much higher.

Claims (25)

CLAIM 1. The use of partial ester (s) of the polyol ester (s) to limit deposits of soap and / or carbon deposits in the interior of injection systems of direct injection engines for (bio) gas oil type fuels having a sulfur content of less than or equal to 500 ^-1 million by weight, the said polyol esters comprise ester structural units x, y hydroxylated structural units and z ether structural units, wherein x, y and z are integers such that x varies from 1 to 10, y modifies i is from 1 to 10 and z varies from 0 to 6, and polyol esters are obtained by esterification of at least one fatty acid with a chain length varying from 10 to 24 carbon atoms and / or at least one dibasic acid substituted with at least at least one polymer, and linear and / or branched polyols, with or without (hetero) rings of 5-6 atoms. 2. The use according to claim 1, characterized in that z varies from 1 to 6. 3. The use according to claim 1, characterized in that the polyol esters are obtained by esterification of the fatty acid (s) of heterocycles of 4-5 carbon atoms and an oxygen atom bearing hydroxyl functional groups. 4. The use according to one of claims 1 to 3, characterized in that in said polyester esters the distribution of ester structural units, hydroxylated structural units and ether ether structural units is such that x varies from 1 to 4, y varies from 1 to 7 and z varies from 1 to 3. 5. The use according to any one of claims 1 to 4, characterized in that the polyols are selected from linear polyols comprising more than three hydroxyl functional groups, and polyols comprising at least one heterocycle of 5-6 atoms, preferably heterocycles of 4-5 carbon atoms and - 10 031490 oxygen atoms, optionally substituted by hydroxyl groups, these polyols can be used individually or in a mixture. 6. The use according to any one of claims 1 to 5, characterized in that the polyol is a polyol comprising at least four structural units represented by the following formula (I) n- (OCH ₂ ) p- (CHOH) _q - ( CH ₂ OH) (I) with p and q representing integers, wherein p is equal to or greater than 0, q is more than 2, and these numbers cannot exceed 10. 7. The use according to any one of claims 1 to 5, characterized in that the polyol is a polyol comprising at least four structural units represented by the following general formula (II) H- (OCH ₂ ) _p - (CR1R2) _q - (CH ₂ OH) (II) with p and q representing integers, wherein p is equal to or greater than 0, q is more than 1, and these numbers cannot exceed 5, R1 and R2 are the same or different and represent either a hydrogen atom, or a CH ₃ or C ₂ H ₅ group, or a —CH ₂ —HO group. 8. The use according to any one of claims 1 to 5, characterized in that the polyol is a polyol comprising at least two heterocycles of 4-5 carbon atoms and an oxygen atom connected to form an acetal bond between the hydroxyl functional group of each cycle, these heterocycles are optionally substituted with hydroxyl groups. 9. The use according to any one of claims 1 to 5, characterized in that the partial esters of the polyols are selected from partial esters of sorbitan, preferably sorbitan monooleate, used individually or in mixture. 10. The use according to any one of claims 1 to 9, characterized in that the polyols are selected from the group consisting of erythritol, xylitol, arabitol, ribite, sorbitol, maltitol, isomaltitol, lactitol, sorbitan, volemit, mannitol, pentaerythritol, 2-hydroxymethyl- 1,3-propanediol, 1,1,1-tri (hydroxymethyl) ethane, trimethylolpropane and carbohydrates such as sucrose, fructose, maltose, glucose and sucrose, preferably sorbitan. 11. The use according to any one of claims 1 to 9, characterized in that the partial esters of the polyols are selected from the group consisting of monoesters or diesters derived from monobasic acids selected from stearic, isostearic, linolenic, oleic, linoleic, behenic , arachidonic, ricinoleic, palmitic, myristic, lauric, capric acids, and mixtures thereof, and / or dibasic acids selected from alkyl or alkenyl succinic, alkyl or alkenyl maleic acids. 12. The use according to claim 1, characterized in that the specified (s) partial ester (s) of the polyol is intended (s) for introduction into the (bio) gas oil motor fuel for the specified engine, preferably in a concentration of at least 20 million by weight of ^-1. 13. Additive to limit deposits of soap and / or carbon deposits in the interior of direct injection engine systems for engine fuels (bio) gas oil type, comprising at least 50 wt.% Of the partial ester (s) of polyols wherein said polyol esters include x ester units, hydroxylated units and z have ether units, and x, y and z are integers such that x varies from 1 to 10, y ranges from 1 to 10 and z varies from 0 to 6, wherein said partial polyol esters are prepared by reacting the polyols with at least one dibasic acid substituted with at least one polymer, these polyols are selected from erythritol, xylitol, D-arabitol, L-arabitol, ribite, sorbitol, maltitol, isomalt , lactitol, sorbitan, volemitis, mannitol, pentaerythritol, 2-hydroxymethyl-1,3-propanediol, 1,1,1tri (hydroxymethyl) ethane, trimethylolpropane and carbohydrates such as sucrose, fructose, maltose, glucose and sucrose. 14. The additive according to item 13, wherein the z varies from 1 to 6. 15. The additive according to item 13, wherein the partial esters of the polyols are selected from the group consisting of monoesters or diesters derived from dibasic acids selected from alkyl or alkenyl succinic, alkyl or alkenyl maleic acids. 16. The additive according to item 13, wherein the polymer is a poly (iso) butene comprising from 8 to 100 carbon atoms. 17. The composition of (bio) gas oil motor fuel having a sulfur content of less than or equal to 500 ^-1 million by weight, comprising at least one additive according to any one of claims 13-16. 18. The composition of (bio) gas oil motor fuel according to 17, further comprising at least one or more other functional additives selected from reducing deposits of additives and / or detergents, and / or dispersants, antioxidants, combustion activators, corrosion inhibitors, additives for improving low temperature characteristics, coloring additives, demulsifiers, antioxidants, antifoam additives, cetane number improvers, lubricants, antiwear additives and / or anti-friction x additives and cosolvents and agents to improve compatibility. - 11 031490 19. The composition of (bio) gas oil motor fuel according to claim 17 or 18, containing up to 10 wt.% One or more additives according to any one of paragraphs. 13-16. 20. The composition of high-grade (bio) gas oil engine fuel, comprising at least 50 ^-1 million by weight of additives reduces deposition / detergents / dispersants, and at least 20 million by weight of ^-1 additive according to any one of claims 13-16. 21. The composition of high-grade (bio) gas oil motor fuel according to claim 20, additionally containing at least one or more other functional additives selected from antioxidants, combustion activators, corrosion inhibitors, additives to improve low-temperature characteristics, coloring additives, demulsifiers, antioxidant additives , antifoam additives, cetane increasing agents, lubricating additives, antiwear additives and / or anti-friction additives, and cosolvents and co-solvents Timing. 22. The composition of (bio) gas oil motor fuel according to any one of claims 17 to 21, having a concentration of complex mono - and diester, varying from 20 to 1000 million ^-1 by mass, preferably between 30 and 200 million ^-1 by mass. 23. The method of soap deposits of plaque control and / or fouling of inner parts of the direct injection engine fuel injection system for (bio) gas oil engine fuels (diesel engine) having a sulfur content of less than or equal to 500 million by weight of ^-1, said method comprising the combustion in the specified engine composition according to any one of paragraphs.17-22. 24. The method according to item 23, wherein the formation of deposits of soap and / or carbon deposits in the internal parts of the engine injection system is avoided or prevented to maintain the specified engine in a clean state. 25. The method according to any one of paragraphs.23 or 24, in which deposits of soap and / or carbon deposits in the internal parts of the engine injection system are removed to clean the engine.