RU2443762C2 - Fuel compositions - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: method for reducing the adverse effect of detergent additive on cold flow of fuel composition containing distillate fuel, detergent additive and additive improving the cold flow, which involves introduction to the above composition of additional additive chosen from: (a) acids and their mixtures; and (b) additives improving the lubricating capacity. Also, there proposed is the method for improvement of cold flow of fuel composition, method improving the detergent additive concentration in fuel composition, method for obtaining fuel composition, method for reducing the amount of additive improving the cold flow and operating method of the fuel consumption system.

EFFECT: improvement of service performance of cold flow of fuel composition containing distillate fuel, detergent additive and additive improving the cold flow.

26 cl, 7 ex, 10 tbl

Description

FIELD OF THE INVENTION

The invention relates to the use for a new purpose of certain types of additives in fuel compositions containing distillate fuels.

State of the art

It is known that fuel compositions containing distillate fuels, including medium distillate fuels such as diesel fuel compositions, are added additives that improve cold flow, in order to improve the performance of fuels at low temperatures. This is especially applicable for "winter" fuel compositions, which are intended for use in cold climatic zones and / or in the cold season. Known cold flow improvers include mid-distillate flow improvers and paraffin precipitation additives.

In addition, detergent additives are added to such fuel compositions in order to reduce, remove, or slow down the formation of precipitation in the engine.

However, it has been found that the effectiveness of cold flow improvers can be adversely affected by the introduction of detergent additives into a fuel composition containing distillate fuel. In some cases, detergents can deactivate (at least partially) an additive that improves cold flow, and a combination of these two factors affects the operational quality of cold flow compared to the quality of the fuel composition without detergents.

SUMMARY OF THE INVENTION

An object of the present invention is to provide fuel compositions containing distillate fuels and / or additives for use in such compositions so that the problems described above can be overcome or at least mitigated.

According to a first concept of the present invention, the use of an additional additive which is selected from: in a fuel composition comprising a distillate fuel, a detergent additive and a cold flow improving additive is developed:

(a) acids, especially carboxylic acids and mixtures thereof; and

(b) lubricity improvers,

in order to reduce the effect of the detergent on the operational quality of the cold flow of the composition.

In a second aspect, the present invention provides for the use in a fuel composition comprising a distillate fuel, a detergent additive and a cold flow improver, an additional additive as defined above in order to improve the operational quality of the cold flow composition.

In a third concept, the present invention provides for the use in a fuel composition containing distillate fuel, a detergent additive and a cold flow improver, an additive as defined above, with the aim of increasing the concentration of the detergent in the composition, or without compromising the operational quality of the cold flow of the composition, or with deterioration in the operational quality of cold flow compared to that which could be caused by an increase in the concentration of the washing additive.

In connection with this third concept of the present invention, the term "increase" covers any degree of increase, for example, by 1% or more of the initial concentration of the detergent additive, preferably 2 or 5, or 10, or 20%, or more. This increase can be correlated with the concentration of the detergent that would otherwise be incorporated into the fuel composition in order to achieve the characteristics and performance that are required and / or desirable in the context of the intended use. For example, it may be the concentration of the detergent additive that was present in the fuel composition until it was understood that an additional additive could be used, as described in the present invention, and / or which was present in another, similar fuel composition, the use of which is intended ( for example, on the market) in a similar context, before adding an additional additive to the composition.

According to a fourth aspect of the present invention, there is provided a method for preparing a fuel composition, which includes: (i) co-mixing distillate fuel, detergent and cold flow improver, optionally with other fuel components, (ii) measuring the cold flow performance of the resulting mixture and (iii) the introduction of an additional additive, as defined above, in sufficient quantities to improve the operational quality of the cold flow of the mixture. In addition, this method may include measuring the operational quality of the cold fluidity of the base fuel and the cold flow improver, measuring the change in the operational quality of the cold flow due to the introduction of a detergent, and introducing an additional additive in an amount sufficient to at least partially and preferably completely counteracting any negative effect of the detergent additive on the operational cold flow quality of the base fuel mixture with the additive improving x adotekuchest.

In a fifth aspect, the present invention provides for the use in a fuel composition comprising a distillate fuel, a detergent additive and a cold flow improver, an additional additive as defined above in order to reduce the amount of a cold flow improver in this composition. Since the additional additive can be used, at least in part, to counteract any negative effect of the detergent additive on the cold flow performance, this potentially makes it possible to reduce the concentration of the cold flow improver, which can be used to achieve the desired desired level of cold flow performance in the whole composition.

In the context of this fifth concept of the present invention, the term “reduction” encompasses any degree of reduction, for example, 1% or more of the initial concentration of cold flow improver, preferably 2 or 5%, or 10 or 20%, although it is not advisable to reduce to zero. This reduction may be correlated with the concentration of cold flow improver that would otherwise be incorporated into the fuel composition in order to achieve the characteristics and performance that are required and / or are desirable in the context of the intended use. For example, it may be the concentration of the cold flow improver that was present in the fuel composition until it was understood that an additional additive could be used, as described in the present invention, and / or which was present in another, similar fuel composition, the use of which it is assumed (for example, on the market) in a similar context, before adding an additional additive to the composition.

For example, in the case of a diesel fuel composition intended for use in an automobile engine, a certain level of cold flow operational quality may be desirable in order for this composition to meet current fuel specifications and / or to guarantee engine operation and / or to satisfy a consumer’s demand, especially in the cold climate zone or during the cold season. In accordance with the present invention, such standards can still be achieved, even with a reduced concentration of cold flow improver, due to the fact that the additional additive reduces the negative effects of any detergent present.

In the following description, the term “distillate fuel composition” is used to mean a fuel composition comprising a distillate fuel, typically a medium distillate fuel. Such a composition may contain 0.1% by volume or more of distillate fuel, typically 1%, or 2, or 5% by volume or more, preferably 5%, or 10, or 25, or 50% by volume or more, typically 75 %, or 80, or 90, or 95% by volume or more, and in each case, the distillate fuel is preferably a medium distillate fuel. The distillate fuel itself may include two or more fuel components. Most preferably, the fuel composition obtained in accordance with the present invention, is fully a medium distillate fuel.

Medium-distillate fuel compositions for which the present invention is used may include, for example, heating oil, industrial gas oils, automotive diesel fuels, distillate marine fuels, or fuel kerosene such as aviation fuel or heating kerosene. A typical composition will be either automotive diesel fuel or heating oil. Preferably, the fuel composition for which the present invention is used is intended for use in an internal combustion engine; more preferably, it is an automobile fuel composition, even more preferably, it is a diesel fuel composition that is suitable for use in an automotive diesel engine (compression ignition).

In particular, the fuel composition may be adapted and / or intended for colder climatic zones and / or for the colder season (for example, it may be a so-called "winter fuel").

In the context of the present invention, a distillate fuel composition may typically comprise, or substantially consists of, substantially or substantially all of the hydrocarbon-based distillate fuel. The term "major fraction" usually means 80% by volume or more, more suitably 90 or 95% by volume or more, most preferably 98 or 99 or 99.5% by volume or more.

In particular, such a base fuel may be a middle distillate fuel, especially a diesel base fuel, in which case it may include a mixture of medium distillate fuel components (usually these components are obtained by distillation or vacuum distillation of crude oil), or fuel components, which together form a mixture of middle distillate. Components of medium distillate fuels or mixtures thereof can usually have a boiling range within the normal range for medium distillates from 125 to 550 ° C or from 150 to 400 ° C.

Diesel base fuel may be automotive gas oil (AGO). Preferably, the diesel base fuel used in the present invention may have a sulfur content of not more than 2000 parts by weight per million (parts per million by weight). More preferably, this fuel will have a low or very low sulfur content, for example, not more than 500 parts by weight / million, preferably not more than 350 parts by weight / million, most preferably not more than 100, or 50, or 10 parts by weight per million sulfur.

Typical components of diesel fuel are medium distillate liquid hydrocarbon oils, such as those derived from gas oil. Such base fuel components may be of organic or synthetic origin. Usually they can have a boiling range within the usual range for diesel fuel from 125 or 150 to 400 or 550 ° C, depending on the variety and application. Typical fuel densities are from 0.75 to 1.0 g / cm ³ , preferably from 0.8 to 0.86 g / cm ³ , at 15 ° C (IP 365 standard) and measured methane numbers (ASTM D613) from 35 to 80, more preferably from 40 to 75 or 70. The fuel boiling point is usually in the range of 150 to 230 ° C., and the boiling point is in the range of 290 to 400 ° C. The kinematic viscosity of fuels at 40 ° C (ASTM D445) can typically range from 1.5 to 4.5 mm ² / s (cSt). However, the fuel composition for use in accordance with the present invention may contain fuel components with indicators outside these ranges, since the properties of the entire mixture can often differ, often significantly, from the properties of the individual components.

Such fuels are usually suitable for use in a compression ignition internal combustion engine (diesel), with an injection of either an indirect or direct type.

The diesel fuel composition that is obtained by carrying out the present invention will preferably also comply with these general specifications. It is advisable that it meets the relevant modern standard technical requirements, for example, such as EN 590: 99 (for Europe) or ASTM D-975-05 (for the USA). As an example, the fuel composition may have a density of from 0.82 to 0.845 g / cm ³ at 15 ° C; boiling point (ASTM D86) 360 ° C or less; cetane number (ASTM D613) of 51 or greater; kinematic viscosity at 40 ° C (ASTM D445) from 2 to 4.5 mm ² / s (cSt)); sulfur content (ASTM D2622) 350 parts by weight per million or less; and / or the total content of aromatic hydrocarbons (IP 391 (modification)) is less than 11% wt. However, the relevant specifications may vary from country to country every year, and may depend on the intended use of the fuel composition.

Gas oil produced from oil can be obtained by refining and optionally by (hydro) refining a source of crude oil. This may be the only gas oil stream obtained in such a refining process, or a mixture of several gas oil fractions obtained in the oil refining process using various technological routes. Examples of such gas oil fractions are straight run gas oil, vacuum gas oil, gas oil obtained by thermal cracking, light and heavy recycle gas oils obtained from fluid catalytic cracking unit, and gas oil obtained from hydrocracking unit. Optionally, gas oil derived from oil may contain a certain amount of a kerosene fraction derived from oil.

Such gas oils can be processed in a hydrodesulfurization unit (GOS) in order to reduce the sulfur content in gas oil to a level suitable for a diesel fuel composition.

In the methods of the present invention, the base fuel may be or contains a so-called "biodiesel" fuel component, such as vegetable oil or a vegetable oil derivative (for example, a fatty acid ester, in particular a fatty acid methyl ester) or other oxygen-containing compounds, such as acids, ketones or ester. Such components are optionally biological derivatives.

The base fuel may be or contain a Fischer-Tropsch derived fuel component, in particular a Fischer-Tropsch derived gas oil. Such fuels are known and used in diesel fuel compositions. They are, or are derived from, Fischer-Tropsch condensation synthesis products, such as a commercially available gas oil obtained in the Shell Medium Distillate Synthesis (Gas-to-Liquid Fuel) process, which is operated in Bintulu, Malaysia.

Typically, other products of the Gas-to-Liquid Fuel process may be suitable for incorporation into a fuel composition prepared in accordance with the present invention. Gases that are converted to liquid fuel components using such methods may include natural gas (methane), liquefied petroleum gas (eg propane or butane), "condensates" such as ethane, synthesis gas (CO / hydrogen) and gaseous products made from coal, biomass and other hydrocarbons.

The detergent additive in the fuel composition may be any additive containing a detergent. Many such additives are known that are commercially available; they are usually added to automotive fuel compositions at a concentration that reduces, removes or slows down the formation of sediment in the engine.

Examples of detergents suitable for use in fuel additives for the purposes of the present invention include polyolefin substituted succinimides or polyamine succinamides, for example polyisobutylene succinimides or polyisobutyleneamine succinamides, aliphatic amines, Mannich bases or amines and polyolefin- (for example, polyisobutene ) maleic anhydride. Succinimide dispersants are described, for example, in GB-A-960493, EP-A-0147240, EP-A-0482253, EP-A-0613938, EP-A-0557516 and WO-A-98/42808. Particularly preferred are succinimides substituted with a polyolefin, such as polyisobutylene succinimides.

Detergents can be present in the composition with a concentration of the active component from 50 to 1000 parts by weight per million, suitably from 100 to 500 or from 100 to 300 parts by weight per million.

The cold flow improver of the fuel composition can be defined as any substance that is capable of improving the operational quality of the cold flow of the composition, as described below. The cold flow improver may be, for example, a middle distillate flow improver (MDFI), or a paraffin precipitation inhibitor (WASA), or a mixture thereof, which is more typical. In the context of the present invention, the cold flow improver may be a paraffin preventing additive, or at least it includes such an additive.

For example, MDFI additives may include vinyl ester compounds, such as vinyl acetate compounds, especially polymers. Alkene copolymers (e.g. ethylene, propylene or styrene, more typically ethylene) and unsaturated esters (e.g. vinyl carboxylates, usually vinyl acetate) are known examples of compounds used as MDFI.

Other known cold flow improvers (also called cold flow improvers) include comb polymers (polymers having multiple branches containing hydrocarbon groups hanging from the polymer backbone), polar nitrogen containing compounds that include amides, amines and amine salts, hydrocarbon polymers and linear polyoxyalkylenes. Examples of such compounds are given in WO-A-95/33805, on pages 3-16 and in the examples.

Additional examples of compounds used as cold flow improvers include those described in WO-A-95/23200. These include comb polymers as defined on pages 4-7, especially those containing vinyl acetate copolymers and alkyl fumarate esters; and further low temperature fluidity additives described on pages 8-19, such as linear oxygenated compounds including alcohol alkoxylates (e.g. ethoxylates, propoxylates or butoxylates) and other esters and ethers; ethylene unsaturated ester copolymers such as vinyl acetate or vinyl hexanoate; polar nitrogen-containing substances such as phthalic acid amide or hydrogenated amines (in particular hydrogenated fatty acid amines); hydrocarbon polymers (in particular ethylene copolymers with other alpha olefins, such as propylene or styrene); sulfur carboxy compounds, such as long chain amine sulfonate salts, aminosulfones or aminocarboxamides; and alkyl aromatic hydrocarbons.

Ideally, compounds used as cold flow improvers will have available or associated protons.

Particularly preferred cold flow improvers for use in the present invention are those that contain nitrogen atoms, preferably associated with protons. Suitable compounds are amines, amine salts and amides, in particular amines and their salts, most preferably protonated amines. It is advisable that at least one such compound is present in the fuel composition obtained in accordance with the present invention.

Cold flow improvers are traditionally included in medium distillate fuel compositions, such as diesel fuel compositions, in order to improve their operational quality at low temperatures, and thus improve the performance of systems at low temperatures (usually automobiles) operating on such compositions.

The concentration (active component) of the cold flow improver in the fuel composition obtained in accordance with the present invention can be up to 1000 parts per million, preferably up to 500 parts per million, more preferably up to 400 or 300 parts by weight ./mln The concentration of the active component will suitably be at least 20 parts by weight per million, preferably at least 30 or 50 parts per million, more preferably at least 100 parts per million.

In the practice of the present invention, the cold flow improver and the detergent are typically such that the cold flow performance of the composition deteriorates when both additives are present, compared to a situation where only the cold flow improver would be present (at the same concentration). In such situations, the present invention can provide a positive result by counteracting an undesired interaction between additives providing cold flow and a washing effect.

The cold flow performance of the fuel composition can be conveniently assessed by measuring the cold filter plugging point (CFPP) for the composition, preferably using the standard IP 309 test method or similar. The clogging point of the cold fuel filter corresponds to the temperature at which (and below it) the paraffins in the fuel will experience severe flow restrictions through the strainer, and may correlate with the performance of the vehicle at low temperatures. A decrease in CFPP will correspond to an improvement in the operational quality of cold flow, ceteris paribus. Improving cold flow characteristics increases the range of climatic conditions or seasons in which fuel can be used efficiently.

The cold flow performance can be estimated by any other suitable method, for example, using the Aral accelerated deposition test (EN 23015) and / or by evaluating the performance of a diesel engine, vehicle or other systems operating on a fuel composition at low temperatures. The temperature at which such performance is measured may depend on the climate in which the fuel composition is intended, for example, in Greece, “low temperature performance” can be evaluated at -5 ° C, whereas in Finland low temperature performance may be required at -30 ° C. In warmer countries, where fuel is typically used at elevated ambient temperatures, it may be necessary to evaluate “low temperature” operational quality at a temperature of only 5–10 ° C below ambient temperature. Typically, an improvement in the operational quality of cold flow can be manifested as a decrease in the minimum temperature at which the operation of a system consuming this fuel composition can satisfy the requirements of this standard.

An improvement in the operational quality of cold flow can be manifested as a decrease, ideally suppression, of the so-called "vibrational" effects that can be observed in the CFPP test at higher temperatures than the CFPP value of the fuel. "Fluctuation" can be interpreted as at least partial blockage of the filter in the CFPP test occurring at a higher temperature than CFPP. Such blockage will occur in the CFPP device, modified to take measurements such as increasing the filtration time, at least at least 60 seconds. In the event of serious fluctuations, the test must be prematurely interrupted, and the CFPP value will be recorded at a higher temperature. Thus, when fluctuations occur to a sufficiently large extent, this does not manifest itself as oscillations, but simply an increased CFPP value is observed. In this application, references to CFPP values can usually be measured in such a way as to take into account the contribution of such vibrational effects (i.e. CFPP values are overestimated due to these effects).

The decrease in vibrational effects can be manifested as the complete absence of the vibrational effect that could be observed when measuring the CFPP value of the fuel composition without adding an additional additive; and / or as a decrease in the intensity of such an oscillatory effect (for example, serious oscillations become only weak oscillations); and / or as a decrease in temperature at which such an oscillatory effect occurs. Since the oscillatory effect can lead to variability of the measured CFPP values for the fuel composition, an increase in the recorded value occurs in the hard test mode; such a reduction can be advantageous, as it can provide a more reliable and accurate measurement of the CFPP value of the composition. In turn, this provides a composition, the composition of which will more closely correspond to and evidently correspond to technical conditions, such as industrial or regulatory standards.

References to an “undesired effect” regarding cold flow performance may be construed in accordance with the foregoing. Such an effect will usually correspond to an increase in the CFPP value of the fuel composition, and / or an increase in vibrational effects when measuring the CFPP of the composition, and / or a deterioration in the performance of the engine or vehicle, or other systems operating on the composition, especially at low temperatures, as described above.

In the context of the first concept of the present invention, the “reducing” effect of the detergent on the cold flow performance is any degree of reducing effect (usually an undesirable effect, for example, manifested as an increase in CFPP) of the detergent on the cold flow performance of the fuel composition. This can be assessed by measuring the operational quality of the cold flow of the composition (including additives that improve cold flow) both before and after the introduction of the detergent additive. Thus, an additional additive can be added in order to reduce the degree of deactivation of the cold flow improver due to the detergent additive and / or any other components present in the fuel composition. Ideally, the effect of the detergent on the operational quality of cold flow can be completely eliminated by the action of the additional additive. In other words, the operational quality of the cold flow of the final composition will be no worse than (in some cases less than) the quality of the composition with an additive that improves cold flow, but without a detergent.

In the context of the second and fourth concept of the present invention, the term "improvement" of the operational quality of the cold flow of the fuel composition includes any degree of improvement compared with the operational quality of the composition before the introduction of additional additives. For example, this term may include controlling the operational quality of the cold flow of a composition, under the action of an additional additive, in order to meet a given goal, for example, a given CFPP value.

Using the present invention, the CFPP value of the composition can be reduced by at least 1 ° C, compared with the CFPP value before the introduction of additional additives, preferably at least 2 ° C, more preferably at least 3 ° C and most preferably at least 4 ° C, or 5, or sometimes 6, or 7, or 8 ° C.

Using the present invention, the CFPP value of the composition can be reduced by at least 0.3% of its value (expressed in degrees Kelvin) before the introduction of an additional additive, more preferably at least 0.5% and most preferably at least 1%, or 1.5, or 2, or even 3, or 4%.

The fuel composition obtained in accordance with the present invention may have a CFPP value of -5 ° C or lower, preferably -10 or -15 ° C or lower. In a preferred embodiment, the composition may have a CFPP value of −20 ° C. or lower, preferably −25, or −28, or −30 ° C. or lower.

According to the present invention, the “additional additive” used in the distillate fuel composition is selected from: (a) acids and mixtures thereof and (b) lubricity improvers. The lubricity improver additive (b) itself may contain one or more acids; thus, an additional additive, which is an acid (in particular, carboxylic acid, and most particularly fatty acid), can be used as a component of the composition of another fuel additive, such as an additive that improves lubricity.

Acid (a) may be inorganic (e.g., nitric) or organic acid, with the latter being preferred. In general, an acid can be defined as any substance capable of giving off protons. It can be mono-, di-, tri- or polyacid, preferably mono-acid (especially if it is organic). This may be an oligomer or a polymer having one or more acid functional groups, for example an olefinic oligomer with an acid functional group. This material may be an acid salt (for example, a protonated amine carboxylate), although it may suitably have, or at least be associated with available protons. In some cases, compounds including phenol, ester, amide or protonated amine groups may be sufficiently acidic in terms of their ability to give off protons in order to be suitable as an additional additive (a) in the present invention. Examples of such compounds include those having electron attracting groups in the vicinity of potentially available hydrogen atoms, for example, compounds of the formula CH ₂ (CO ₂ R) ₂ or CH ₃ COCH ₂ CO ₂ R, where R is hydrocarbyl, typically alkyl , group. In this regard, fully or partially hydrolyzed carboxylate esters can be used as a proton donor.

If acid (a) is an organic acid, for example, it can be selected from carboxylic acids and sulfonic acids (in particular benzenesulfonic acids, optionally substituted with, for example, alkyl or hydroxyl groups). Preferably, it is a carboxylic acid, and thus may be any organic acid containing —CO ₂ H or —CO ₂ ^- H ⁺ groups. The acid may be aliphatic (or saturated, or at least partially unsaturated, and optionally includes cyclic moieties) or aromatic, straight or branched chain. For example, it may contain from 1 to 30, preferably from 1 to 20 carbon atoms. The acid may be substituted by other groups, as well as an acid group; for example, it may be a hydroxy acid, such as lactic or glycolic acid, or a carbonyl substituted acid, such as levulinic acid. It may be an unsaturated acid, such as acrylic or methacrylic acid, or their derivatives, in particular oligomers or polymers.

Particularly preferred carboxylic acids for use in the present invention are fatty acids and mixtures thereof. Such fatty acids may be saturated or unsaturated (which include polyunsaturated acids). For example, they may contain from 1 or 2 to 30 carbon atoms, usually from 10 to 22 carbon atoms, preferably from 12 to 22, or from 14 to 20 carbon atoms, more preferably from 16 to 18 carbon atoms and most preferably 18 carbon atoms . Examples include oleic acid, linoleic acid, linolenic acid, linoleic acid, stearic acid, palmitic acid and myristic acid. Of these, oleic, linoleic and linolenic acids, more preferably oleic and linoleic acids, may be preferred.

Fatty acid dimers or oligomers can also be used as additional additives (a).

In one embodiment of the present invention, the additive (a) is tall oil fatty acid, which is derived from tall oil and contains mainly fatty acids (such as oleic and linoleic) with a small proportion of resin acids. Tall oil fatty acids have already been used as a lubricity improver.

In another embodiment of the present invention, the additional additive (a) is acetic acid. In addition, other carboxylic acids from C ₁ to C ₁₀ , or from C ₁ to C ₈ , or from C ₁ to C ₆ , or from C ₁ to C ₄ can be used as an additional additive.

For example, a mixture containing two or more, preferably three or more, suitably four or more, carboxylic acids (ideally fatty acids) may be preferred for use in the present invention. Such acids may be selected, for example, from oleic, linoleic, linolenic, stearic and palmitic acids.

A particularly preferred mixture may contain from 25 to 85% wt. (usually from 35 to 75 or from 40 to 70 or from 50 to 60% wt.) oleic acid, and / or from 5 to 50% wt. (it is advisable from 10 to 40, or from 10 to 30, or from 15 to 25% wt.) linoleic acid, and / or from 1 to 30% wt. (it is advisable from 2 to 20 or from 5 to 15% wt.) linolenic acid, and / or from 1 to 30% wt. (it is advisable from 2 to 20, or from 5 to 15, or from 5 to 10% wt.) stearic acid, and / or from 1 to 30% by mass. (it is advisable from 2 to 20, or from 5 to 15, or from 5 to 10% wt.) Palmitic acid. Such a mixture preferably contains at least oleic and linoleic acids, more preferably at least oleic, linoleic and linolenic acids, and most preferably oleic, linoleic, linolenic, stearic and palmitic acids.

Another preferred carboxylic acid for use in the present invention is an aromatic compound having at least one carboxy group attached to an aromatic core, as disclosed in WO-A-98/01516, in particular on page 2, lines 28 -35, on p. 4, line 3 to p. 5, line 11 and on p. 8, lines 4 to 18. Such aromatic acids may include naphthalene and other diaromatic or polyaromatic acids, as well as benzoic acid. Preferably, these acids are substituted with one or more alkyl and / or alkoxyl groups. Typically, the acid is an alkyl substituted salicylic acid having the formula (R) _n —C ₆ H _(4-n) (OH) CO ₂ H, where each R substituent is independently selected from straight and branched chain alkyl groups, optionally substituted ( although preferably unsubstituted) having from 6 to 30, preferably from 8 to 22, more preferably from 8 to 18 carbon atoms, and n is an integer from 1 to 4, preferably 1. Of course, the additional additive (a) may be a mixture of two or more such alkyl substituted aromatic acids.

A lubricity improver (b) is any additive capable of enhancing the lubricity of a distillate fuel composition and / or imparts antiwear properties to the composition when used in an engine or other fuel consuming system. Although it is known that such additives are part of distillate fuel compositions, such as diesel fuels, it has not been previously established that they can affect the operational quality of cold flow, in particular in the presence of a detergent additive, which itself impairs the operational quality of cold flow.

The lubricity improver may contain, usually as an active component (s), one or more carboxylic acids, such as the aforementioned acids, in particular fatty acids and / or alkyl salicylic acids. Alternatively, non-acidic substances, such as esters or amides, may be active additives.

Suitable esters for use in such additives are carboxylic acid esters, in particular those derived from fatty acids, such as those described above. In addition, oligomers or polymers with ester functional groups (e.g., olefin oligomers) can be used. Such esters may be mono-alcohol esters such as methyl esters, or more suitably may be polyol esters such as glycerol esters. Most preferred are mono-, di- or triglycerides of fatty acids, or, suitably, a mixture of two or more of these components.

Suitable amides for use in such additives are fatty acid amides in which preferred fatty acids may be as described above, for example, mono- or especially dialkanolamines, such as diethanolamine, fatty acid amides.

Suitable commercially available lubricity improvers include fatty acid based R650 (from Infineum), a fatty acid ester of R655 (from Infineum) and an amide based of Hitec ™ 4848A (from Afton).

Other suitable lubricity enhancing additives are described, for example, in documents:

- article by Danping Wei and N.A. Spikes, “Lubricity of Diesel Fuels,” Wear, III (1986), pp. 217-235;

- WO-A-95/33805 (see above) - additives that enhance cold flow, which increase the lubricity of low-sulfur fuels;

- WO-A-94/17160 - certain esters of carboxylic acids and alcohols in which the acid has from 2 to 50 carbon atoms and the alcohol has one or more carbon atoms, especially glycerol monooleate and diisodecyl adipate, as fuel additives to reduce wear in diesel engine injection system; and

- US-A-5490864 — Certain dithiophosphoric acid diesters as anti-wear lubricants for low-sulfur diesel fuels.

Preferably, the lubricity improver additive (b) comprises one or more fatty acids or derivatives of fatty acids (in particular esters and / or amides), for example, as defined above. More preferably, the additive contains one or more fatty acids. Commercially available examples of such additives include Infineum's R650 and Lubrizol's Lz 539 series products.

The lubricity improver (b), in addition to the active key lubricity improvers, may contain other components, for example anti-fog agents and / or anti-corrosion agents, as well as traditional solvents and / or fillers. Alternatively, the additional additive (b) may substantially or even entirely consist of the lubricity improving active ingredient, or mixtures thereof, of the type described above.

In accordance with the present invention, several additional additives may be used in the fuel composition.

In some cases, it may be appropriate that the lubricity improver additive (b) used as an additional additive in the present invention is not a compound such as those described in WO-A-95/33805 (on pages 3 to 16 and / or in the examples), as an additive that improves cold flow.

It may be appropriate that the lubricity improver additive (b) used as an additional additive in the present invention is not a polymer and / or is not an amine salt, and / or in certain cases is not an amide.

In accordance with the present invention, the additional additive can be used in the distillate fuel composition at any suitable concentration, for example, up to 3000 parts by weight per million, sometimes up to 2000 or 1000 parts per million, preferably up to 700 parts by weight ./mln, more preferably up to 500 ppm, or up to 400, or 300, or sometimes 200 ppm. The concentration of the additive may be at least 1 parts by weight per million, preferably at least 5 or 10 parts by weight per million, preferably at least 50 or 100 parts per million. The concentration used may depend on the concentration of detergents and cold flow improvers present in the composition and on the desired operational quality of the cold flow. In some cases, it may be advisable that the concentration of the additional additive be such as to obtain an acidity value equivalent to the oleic acid used at a concentration in the above range.

An additional additive, which is an additive that improves lubricity, can be used in the fuel composition in accordance with the present invention, at a concentration that differs from the usual one, for example, higher than with a standard processing rate. Thus, a lubricity improver in accordance with the present invention may include the introduction of an additive in a concentration different from that which would be necessary, or desirable, or normal if it was introduced into the composition only to improve the lubricity performance. This use may include the introduction of the additive in a concentration that is higher than that which would be necessary, or desirable, or normal in order to impart the appropriate lubricity to the entire fuel composition (for example, taking into account any other additives present in the composition).

In particular, the use of a lubricity improver in accordance with the present invention may include the incorporation of an additive in a fuel composition that already has a suitable lubricity (usually because one or more lubricity improvers are already present).

In the context of the present invention, the term “use” of an additive in a fuel composition means the introduction of an additive into the composition, usually in the form of a mixture (ie, physical mixture) with one or more other fuel components. The additive can be conveniently administered prior to adding the composition to the internal combustion engine or other system that will operate on this composition. In addition, or in addition to this, the use of the additive may include a working system that consumes fuel, typically a diesel engine operating on a fuel composition containing the additive, typically by introducing the composition into the combustion chamber of the engine.

The “use” of an additional additive by the methods described above may also include supplying such an additional additive (together with instructions for its use) to the distillate fuel composition in order to achieve the goal (s) in any (1 to 5) aspect of the present invention, for example, to achieve goals - the level of operational quality of cold fluidity (for example, the desired value of CFPP) and / or to reduce the concentration of additives that improve cold flow, in the composition. An additional additive may actually be supplied as a component of a formulation that is suitable for use and / or is intended to be used as a fuel additive. In this case, an additional additive can be introduced into such a formulation in order to influence the operational quality of the cold flow of the distillate fuel composition.

Thus, an additional additive can be introduced into the formulation or in the additive package along with one or more other fuel additives, for example, with the detergent itself.

According to the present invention, a distillate fuel composition — in particular when it is a diesel fuel composition — may contain other components besides a detergent additive and a cold flow improver, and an additional additive. Such components will typically be present in fuel additives. Examples are lubricity enhancing additives; anti-turbidity agents, for example, alkoxylated polymers of phenol and formaldehyde; anti-foaming agents (for example, polyester modified polysiloxanes); ignition improvers (cetane additives) (e.g. 2-ethylhexyl nitrate (EHN), cyclohexyl nitrate, di-tert-butyl peroxide and those described in US-A-4208190, column 2, line 27 to column 3, line 21 ); anticorrosive agents (for example, a polyester of propane-1,2-diol and tetrapropenyl succinic acid, or esters of polyhydric alcohols and succinic acid derivatives, succinic acid derivatives having one alpha carbon atom, an unsubstituted or substituted aliphatic hydrocarbon group containing from 20 to 500 carbon atoms, for example, diester of pentaerythritol and polyisobutylene substituted succinic acid); corrosion inhibitors; deodorants; antiwear additives; antioxidants (for example, phenolic, such as 2,6-di-tert-butylphenol, or phenylenediamines, such as N, N'-di-sec-butyl-para-phenylenediamine); metal deactivators; antistatic additives; and combustion improvers. Such components may be administered with other additives, for example with detergents.

The distillate fuel composition may, for example, include lubricity enhancing additives, in particular when the fuel composition has a low sulfur content (for example, 500 parts by weight / million or less). Lubricity enhancing additives are conveniently used in a concentration of less than 1000 ppm, preferably from 50 to 1000 or 100 to 1000 ppm, more preferably from 50 to 500 ppm. Suitable examples of lubricity enhancing additives include those described above in connection with the additional additive (b).

In addition, it may be preferable that the fuel composition contains an anti-foam agent, more preferably in combination with an anti-corrosion agent and / or corrosion inhibitor and / or lubricity improver.

Unless otherwise indicated, the concentration of each such additional component in the fuel composition preferably reaches 10,000 parts by weight / million, more preferably in the range from 0.1 to 1000 parts by weight / million, preferably from 0.1 to 300 weight. hours / million, for example, from 0.1 to 150 parts by weight / million (All references in this description to the concentration of additives, unless otherwise indicated, refer to the concentration of the active component by weight).

The concentration of any anti-cloud agent in the fuel composition will preferably be in the range from 0.1 to 20 parts by weight / million, more preferably from 1 to 15 parts by weight / million, even more preferably from 1 to 10 parts by weight. / million, mainly from 1 to 5 parts by weight / million The concentration of any ignition improver will preferably be 2600 ppm or less, more preferably 2000 ppm or less, conveniently 300 to 1500 ppm.

If desired, one or more additive components, such as those listed above, can be mixed together — preferably together with suitable diluent (s) —in the additive concentrate, and then the additive concentrate can be dispersed in the fuel composition in a suitable amount.

For example, a distillate fuel additive may contain a detergent, optionally together with other components, as described above, and a distillate fuel compatible diluent, which in the case of diesel fuel may be a non-polar hydrocarbon solvent such as toluene, xylene, white spirit and those sold by Shell under the SHELLSOL trademark and / or a polar solvent, such as an ester or especially an alcohol, for example hexanol, 2-ethylhexanol, decanol, isotridecanol and mixtures of alcohols, most preferably 2-ethylhexanol. An additional additive in accordance with the present invention can be incorporated into such an additive formulation.

The total additive content in the fuel composition may suitably be from 50 to 10,000 parts per million, preferably below 5,000 parts per million.

Additives can be added at various stages in the process of preparing a fuel composition; for example, additives added at a refinery can be selected from antistatic agents, additives that reduce hydrodynamic resistance in the pipeline, additives that improve fluidity, additives that enhance lubricity, antioxidants and additives that prevent the deposition of paraffins. In the practice of the present invention, the base fuel may already contain such refineries. Other additives may be added after the refinery.

In accordance with a sixth aspect of the present invention, there is provided a fuel composition comprising a base distillate fuel, a detergent additive, a cold flow improver, and an additional additive that is selected from:

(a) acids, in particular carboxylic acids, and mixtures thereof; and

(b) lubricity improvers.

The additional additive may be as defined above in connection with aspects (1 to 5) of the present invention. In particular, it may be a carboxylic acid, for example a C ₁ -C ₁₀ carboxylic acid, such as, for example, acetic acid. And in this embodiment, the base distillate fuel is preferably a base mid-distillate fuel.

In accordance with a seventh aspect of the present invention, there is provided a method for producing a fuel composition, such as a composition in accordance with the sixth aspect, the method comprising mixing a distillate (usually middle distillate) base fuel with a detergent additive, a cold flow improver and an additional additive, which is defined above. This mixing is ideally carried out for one or more purposes, which are described in connection with aspects (1 to 5) of the present invention, in particular with respect to the cold flow characteristics of the resulting fuel composition.

The method according to the seventh concept of the present invention may form part of the method (or is intended for use in the system) regulating the mixing of the fuel composition, for example, in a refinery. Typically, such a system may include means for introducing each of the respective additives and base distillate fuel into the mixing chamber, a flow control means for independently controlling the volumetric flow rate of the additives and base fuel into the chamber, a device for calculating the ratios of each of the additives that are necessary to achieve the specified cold flow characteristics (for example, a given CFPP value) that the consumer enters into the system, and a device for transmitting the result of this calculation to the monitoring means outflow, which can then be exploited to achieve the specified ratio of additives in the resulting composition by changing the flow rate of the components of the composition into the mixing chamber.

In order to calculate the necessary ratios in a method or system of this type, it is convenient to use the known cold flow characteristics for the base fuel under consideration, and it is also advisable to use a model that predicts and / or describes data on the cold flow characteristics of fuel compositions containing various ratios of the respective additives. In accordance with the present invention, then, in a method or system, for example, a cold-flow improver concentration can be selected and obtained lower than predicted as necessary only if a cold-flow improver and a detergent are present.

Thus, the present invention can be conveniently used to automate, at least partially, the formulation of a distillate fuel composition, while preferably controlling the relative ratio of additives to base fuel introduced into the composition in real time, for example, by adjusting relative flow rates or component flow durations.

In an eighth aspect of the present invention, there is provided a method of operating a fuel consuming system, the method comprising introducing into the system a fuel composition in accordance with the sixth aspect of the present invention and / or a fuel composition obtained in accordance with any one of aspects 1-5 or the seventh aspect. And in this case, the fuel composition is preferably administered for one or more of the purposes described above, in connection with aspects of the present invention (1 to 5). Thus, the system is preferably operated with the fuel composition of the present invention in order to improve the low temperature performance of the system.

In particular, the system may be an internal combustion engine, and / or a vehicle equipped with an internal combustion engine, in which case the method includes introducing an appropriate fuel composition into the combustion chamber of the engine. The preferred engine is a compression ignition engine (diesel). Such a diesel engine may be of a type with direct injection, for example with a rotary pump, an integrated pump, a block pump, with an electronic unit of an injector or a conventional railway type, or of a type with indirect injection. It can be a heavy duty or light duty diesel engine.

Throughout the text of the description and claims of the present invention, the expressions "includes" and "contains" and variations of these expressions, for example, "includes" and "includes", mean "including, but not limited to," and are not intended (and indeed not ) to exclude other fragments, additives, components, a whole or steps.

Throughout the text of the description and claims of the present invention, the singular includes the plural, unless the context requires otherwise. In particular, where an indefinite article is used, it should be understood that the text of the description includes both the plural and the singular, unless the context requires otherwise.

Preferred features of the second and following aspects of the present invention can be described in connection with any other aspects.

Other features of the present invention will become apparent upon consideration of the following examples. In essence, the present invention extends to any new, or any new combination of features disclosed in this application (including any accompanying claims and drawings). Thus, it should be understood that the features, the whole, characteristics, compounds, chemical fragments or groups described in combination with the specific aspects, options or examples of the present invention can be applied to any other aspects, options or examples described in this application if they are compatible with this.

Moreover, unless otherwise stated, any feature disclosed herein may be replaced by an alternative feature suitable for the same or similar purpose.

The following examples illustrate the characteristics and performance of the fuel compositions obtained in accordance with the present invention, and evaluate the effect of various additives on the performance of cold flow for diesel compositions.

Several samples of industrially available diesel fuels are taken, some of which already contain additives that improve cold flow. For other fuels, cold flow improvers were introduced in accordance with the instructions of the additive manufacturer (usually at a temperature of 45 to 65 ° C, followed by cooling to ambient temperature, approximately 20 ° C), in these cases the cold flow improvers contain both additives MDFI, as well as WASA, usually in concentrations from 150 to 200 parts by weight / million.

Other additives are gradually added to the fuel, either while it is still warm, or at ambient temperature, for reasons of convenience.

The cold flow performance is evaluated by measuring the cold filter clogging temperature (CFPP) for fuel / additive mixtures using a 5GS CFPP testing apparatus (from ISL) and a methodology essentially similar to the standard IP 309 test method.

The following lubricity improvers are used:

Additive commercially available additive containing a mixture of fatty acids BUT tall oil Additive a commercially available additive containing a mixture of fatty acids, AT mainly C ₁₆ -C ₂₂ (mainly C ₁₆ -C ₁₈ ) Additive a commercially available ester additive containing FROM a mixture of glycerol esters of linoleic acid, mainly mono (linoleate) glycerol, di (linoleate) glycerol and tri (linoleate) glycerol in a ratio of about 4: 4: 1 Additive commercially available additive containing a mixture of fatty acids D tall oil Additive commercially available additive containing a mixture of fatty acids E tall oil Additive an additive containing alkyl salicylic acid, such as described in F WO-A-98/01516 on page 8, lines 4-18; and Additive amides, commercially available, containing amides G fatty acids, tall oil with diethanolamine, general formula RC (O) -N (CH ₂ CH ₂ OH) ₂ .

Example 1

An industrially available diesel fuel composition obtained from Germany is mixed with standard cold flow improvers (150 parts per million MDFI and 150 parts per million WASA) in order to obtain a fuel composition meeting the specifications of EN 590: 99 for winter diesel for Germany. Then this composition (fuel F1) is mixed with a detergent additive and with additional additives in accordance with the present invention. Measure the cold filter clogging temperature (CFPP) for each mixture as described above. Some measurements are performed twice or three times using different test kits, with CFPP measurements for each mixture being designated as # 1, # 2 and # 3.

The fuel composition (before adding an additive that improves cold flow) has the technical conditions shown in table 1.

Table 1 Fuel characteristic Test method Density at 15 ° C (g / cm ³ ) IP 365 0.8352 Cloud Point (° C) IP 219 -8 CFPP (° C) IP 309 -11 (no hesitation) Kinematic viscosity at 40 ° C (mm ² / s) (cSt) IP 71 3,284 IQT cetane number IP 498 53.5 Distillation (° C) IP 123 Boiling point 165.8 10% recovered at 224.7 50% recovered 281.7 80% recovered 321.9 90% recovered 342.2 95% recovered at 358.6 Boiling point 365,4 Aromatic hydrocarbons (wt.%) IP 391 Mono- 20.3 Di- 3.4 Three- 0.4 Total 24.1 Total sulfur (mg / kg) ASTM D2622 <5

In these experiments, OCTIMISE ™ D3016 detergent (from Octel) containing polyisobutylene succinimide polyamine (as a detergent active component) and small amounts of other fuel additives, including silicone anti-fog agent and anti-fog agent, are used. The nominal amount of additives is 1000 parts by weight per million.

Additional additives used in accordance with the present invention are industrially available additives A, B and C, improving lubricity, which are described above.

These results are shown in Table 2. For compositions that do not contain detergents or additives, the results are the average of several repeated measurements, with the measurement range shown in parentheses. In addition, Table 2 provides details on the vibrational effects (if any); this data can help interpret CFPP readings.

table 2 Detergent additive (parts by weight / million) Additional additive (parts by weight / million) CFPP # 1 (° C) CFPP # 2 (° C) CFPP # 3 (° C) 0 0 -26 (-24 to -28) -25 (-24 to -25) 1000 0 -25 severe fluctuations at -15 / -21 -19 -19 1000 Additive A (500) -26 -24 1000 Additive A (300) -24 severe fluctuations at -21 -21 -26 soft vibrations at -21 1000 Additive B (500) -26 -26 1000 Additive C (500) -26 soft vibrations at -21 -twenty -27 soft vibrations at -21 1000 Additive B (150) -26 -26

From table 2 it is seen that the CFPP value for the fuel composition F1 (with an additive that improves cold flow) is approximately at -25 to -26 ° C. The introduction of a detergent additive leads to a significant increase in CFPP, which indicates an undesirable interaction of an additive that improves cold flow, and added in the subsequent detergent additive.

However, the addition of a lubricity improver in accordance with the present invention results in an unexpected decrease in CFPP, and thus counteracts the negative effects of the detergent. In addition, the severe fluctuations observed for CFPP # 1 readings with a single detergent additive are reduced, and most cases are excluded after adding an additional additive.

It was found that two additives are effective for various amounts administered (additive A at 500, as well as 300 parts by weight per million, and additive B at 500, as well as 150 parts per million).

Example 2

The second commercially available diesel composition F2 (from Shell) was obtained from Germany. The composition contains a standard cold flow improver (80 to 120 ppm MDFI R252 and 150 ppm WASA R474 (both from Infineum)). Composition F2 is mixed with a detergent additive (OCTIMISE ™ D3016) and with an additional additive in accordance with the present invention. For each mixture, the CFPP value is measured as in example 1.

The fuel composition F2 (already containing a cold flow improver) has the specifications shown in table 3.

Table 3 Fuel characteristic Test method Density @ 15 ° C (g / cm ³ ) IP 365 0.8448 Cloud Point (° C) IP 219 -eleven Kinematic viscosity at 40 ° C (mm ² / s; cSt) IP 71 2,999 IQT cetane number IP 498 55.1 Distillation (° C) IP 123 Boiling point 167.6 10% recovered 227.9 50% recovered 275.4 80% recovered 309.4 90% recovered 328.9 95% recovered 348.5 Boiling point 356.7 Aromatic hydrocarbons (wt.%) IP 391 Mono- 25.5 Di- 5,6 Three- 0.5 Total 31.6 Total sulfur (mg / kg) ASTM D2622 eleven

As additional additives used: (a) acetic acid, (b) additives that improve the lubricity of A, B, D and E, as described above, and (c) a mixture of fatty acids containing oleic acid (55% wt.), linoleic acid (19% wt.), linolenic acid (9% wt.), stearic acid (8.5% wt.) and palmitic acid (8.5% wt.).

The CFPP measurements are shown in Table 4. For compositions that do not contain detergents or additives, the results are the average of several repeated measurements, with the measurement range shown in parentheses.

Table 4 Detergent additive (parts by weight / million) Additional additive (parts by weight / million) CPPP # 1 (° C) CFPP # 2 (° C) CFPP # 3 (° C) 0 0 -30 (-29 to -31) -31 (-30 to -31) -29 (-28 to -30) 1000 0 -twenty -19 1000 Additive A (500) -29 -thirty 1000 Acetic acid (110) -25 -21 -thirty 1000 Additive A (300) -29 -29 1000 Additive B (500) -27 -28 1000 Additive B (150) -thirty -thirty 1000 Additive D (500) -28 -28 -29 1000 Additive E (290) -thirty -31 -32 1000 Mixed Acids (500) -thirty -27 -thirty

From table 4 it is seen that the CFPP value for the fuel composition F2 is about -30 ° C. The introduction of a detergent additive leads to a significant increase in CFPP, to -20 ° C, which indicates an undesirable interaction between the additive present in F2 that improves cold flow and the subsequent detergent additive.

However, the addition of additional additives in accordance with the present invention leads to a decrease in CFPP, and thus at least partially counteracts the negative effects of the detergent. It turned out that in some cases, the influence of the detergent on the operational quality of cold flow is completely eliminated due to the additional additive.

Particularly effective additional additives include a mixture of fatty acids and fatty acid-based additives that improve lubricity, such as additives A, B and E.

It turned out that two such additives are effective for various amounts administered (Additive A at 500, as well as 300 parts by weight per million, and Additive B at 500, as well as 150 parts by weight per million).

Example 3

Example 1 is repeated, but using a formulation containing polyisobutylene succinimide (based on polyisobutylene with a number average molecular weight of about 1000) tetraethylene pentamine as a detergent. The standard amount entered for this additive is 636 parts per million.

Additional additives used in accordance with the present invention are (a) acetic and linolenic acids and (b) additives that improve the lubricity of F, C, G and A.

These results are shown in Table 5. For compositions that do not contain any detergents or additives, the results are the average of several repeated measurements, with the measurement range shown in parentheses. In addition, Table 5 provides details on the vibrational effects (if any).

Table 5 Detergent additive (parts by weight / million) Additional additive (parts by weight / million) CFPP # 1 (° C) CFPP # 2 (° C) CFPP # 3 (° C) 0 0 -26 (-24 to -28) -25 (-24 to -25) 636 0 -19 severe fluctuations at -17 -19 -17 636 Additive F (225) -twenty -30 severe fluctuations at -21 -30 soft vibrations at -20

636 Additive F (450) -26 -24 636 Acetic acid (110) -27 -24 -25 636 Additive C (500) -25 -24 636 Additive G (500) -24 -24 636 Additive A (500) -27 -24 -26 636 Additive C (1000) -28 -28 636 Additive G (1000) -25 -27 -25 636 Linolenic Acid (500) -26 -twenty -26

And in this case, the data show that using the additional additive in accordance with the present invention, the operational quality of the cold fluidity of diesel fuel can be improved, containing both an additive that improves cold flow and a cleaning additive, obviously negating the negative effects of the washing additive.

Example 4

Example 2 is repeated, but using the same detergent additive as in Example 3. The additional additives used in accordance with the present invention are (a) acetic acid and (b) lubricity improvers F and A as described above .

These results are shown in Table 6. For compositions that do not contain detergents or additives, the results are the average of several repeated measurements, with the measurement range shown in parentheses.

Table 6 Detergent additive (parts by weight / million) Additional additive (parts by weight / million) CFPP # 1 (° C) CFPP # 2 (° C) CFPP # 3 (° C) 0 0 -30 (-29 to -31) -31 (-30 to -31) -29 (-28 to -30) 600 0 -eighteen -19 636 Additive F (225) -31 -31 -twenty 636 Additive F (450) -29 -thirty 636 Acetic acid (110) -32 -31 -29 636 Additive A (500) -31 -28 -thirty

Example 5

In addition, industrially available diesel fuels from F3 to F5 obtained during the winter season were tested in the same manner as in Examples 1-4 above. All samples either contained cold flow improvers or were mixed with cold flow improvers before adding any of the detergents or additional additives.

The F3 fuel composition is based on the same commercially available German diesel fuel that was used in Example 1, but was mixed with 200 parts per million MDFI and 150 parts per million WASA. The cloud point of the composition prior to the introduction of the cold flow improver was −8 ° C.

Fuel composition F4 is a Dutch fuel containing 150 ppmw of MDFI and 150 ppmw of WASA. The cloud point of the composition prior to the introduction of the cold flow improver was −10 ° C.

The F5 fuel composition is a German fuel containing standard cold flow improvers (including MDFI and at least 150 parts per million WASA). The cloud point of the composition, before the introduction of additives that improve cold flow, was -9 ° C.

The same detergent additives are used as in Example 1, with a standard degree of administration (1000 parts by weight per million). Mixtures with various additional additives are prepared in accordance with the present invention.

The CFPP measurement results are shown in Table 7. For F3 compositions containing no detergent or additional additive, the results are the average of several repeated measurements, with the measurement range shown in parentheses.

Table 7 Fuel Detergent additive (parts by weight / million) Additional additive (parts by weight / million) CFPP # 1 (° C) CFPP # 2 (° C) CFPP # 3 (° C) F3 0 0 -31 (-30 to -31) -31 (-) F3 1000 0 -25 -24 F3 1000 Additive A (500) -27 -28 F3 1000 Additive B (500) -28 -28 F4 0 0 -21 -27 -twenty F4 1000 0 -fifteen -17 -fifteen F4 1000 Additive B (150) -twenty -twenty F5 0 0 -28 -thirty F5 1000 0 -twenty -27 -21 F5 1000 Additive B (150) -thirty -28

And in this case it is clear that the introduction of additives that improve lubricity, negates the negative impact of detergent additives on the operational quality of cold flow.

Example 6

The diesel fuel used as the starting material in Example 1 is mixed with various additives selected from (i) the detergent used in Example 1, (ii) two cold flow improvers (MDFI and WASA), and (iii) additives, improves lubricity A. For each mixture, the CFPP value is measured as in example 1.

CFPP data are shown in table 8.

Table 8 Additive MDFI (ppm) Additive WASA (parts by weight / million) Detergent additive (parts by weight / million) Additive A (parts by weight / million) CFPP # 1 (° C) CFPP # 2 (° C) CFPP # 3 (° C) 150 150 0 0 -27 -25 0 0 0 0 -eleven -eleven 0 0 0 500 -9 -10 0 0 1000 500 -9 -10 150 150 0 500 -28 -28

The first line of Table 8 shows that the introduction of standard cold flow improvers into the fuel composition results in a CFPP value of about -27 ° C. Without these additives (second row of table 8), the CFPP value of the composition increases to -11 ° C. The introduction of a single lubricity enhancer or lubricity improver together with a detergent does not seem to significantly affect the CFPP value.

It also turned out that the introduction of an additive that enhances the lubricity with an additive that improves cold flow does not significantly affect the value of CFPP, compared with the effect for fuel with a single additive that improves cold flow. This suggests that in order to achieve the beneficial effects of the present invention (for example, as can be seen from examples 1-5), it is necessary to introduce cold flow additives and detergents, as well as an additional additive of the present invention. In other words, between the three additives taken together, an unexpected synergy appears, thereby reducing the undesirable interaction between the cold flow additives alone and the detergents.

Example 7

This example illustrates that an additional additive can be incorporated into the fuel composition in accordance with the present invention in order to mitigate undesirable vibrational effects when combining a detergent and a cold flow improver.

Both fuel compositions F1 and F4 containing standard cold flow improvers (in each case MDFI and WASA in combination) are mixed with detergents and additional additives and subjected to CFPP tests, as in the previous examples.

Table 9 shows the results for F1 fuel in combination with the OCTIMISE ™ D3016 detergent additive used in Example 1. According to the present invention, the following additives are used as additional additives: (a) stearic acid and (b) lubricant additives B and C ability. In case of fluctuations, this is noted along with CFPP data; all values are given in degrees ° C.

Table 9 Detergent additive (parts by weight / million) Additional additive (parts by weight / million) CFPP # 1 (° C) CFPP # 2 (° C) CFPP # 3 (° C) 0 0 -25 -25 1000 0 -25 severe fluctuations at -15 / -21 -19 -19 1000 Additive B (150) -26 -26 1000 Stearic Acid (500) -21 -twenty 1000 Additive C (500) -26 soft vibrations at -21 -twenty -27 soft vibrations at -21

You can see that the introduction of the detergent causes a noticeable increase in CFPP, and serious vibrational effects in one of the used research kits. In the presence of additive C, only mild vibrations are observed, more likely at -21 ° C than at -15 ° C, as well as at -21 ° C. Fluctuations at -15 ° C are also eliminated in the presence of stearic acid. The introduction of additive B leads to the complete elimination of vibrational effects. Thus, the additional additive of the present invention can attenuate the vibrational effects, and a fuel is obtained which is likely to have less problems when testing the CFPP.

Table 10 shows the results for F4 fuel in combination with OCTIMISE ™ D3016 Detergent. In accordance with the present invention, an additive B based on a fatty acid, which improves lubricity, is used as an additional additive. In case of fluctuations, this is noted along with CFPP data; all values are given in degrees ° C.

Table 10 Detergent additive (parts by weight / million) Additional additive (parts by weight / million) CFPP # 1 (° C) CFPP # 2 (° C) CFPP # 3 (° C) 0 0 -21 gradual cessation of soft vibrations at -19 -27 gradual cessation of soft vibrations at -21 -twenty 1000 0 -15 severe fluctuations at -13 -17 soft vibrations at -13 -15 soft vibrations at -13 1000 Additive B (150) -twenty -twenty

In this case, the introduction of a detergent leads to serious oscillatory effects in one of the used research kits, and soft vibrations in the other two research kits. It turns out that even without a detergent additive, soft vibrations are still observed in this fuel. The introduction of additive B completely eliminates the vibrational effects.

Claims (26)

1. A method of reducing the negative effect of a detergent additive on the cold flow of a fuel composition containing distillate fuel, said detergent additive and an additive for improving cold flow, which comprises introducing into said composition an additional additive selected from:
(a) acids and mixtures thereof; and
(b) lubricity improvers. 2. A method for improving the cold fluidity of a fuel composition comprising a distillate fuel, a detergent additive and an additive for improving cold flow, which comprises introducing into said composition an additional additive selected from:
(a) acids and mixtures thereof; and
(b) lubricity improvers that contain one or more carboxylic acids. 3. A method of increasing the concentration of a detergent additive in a fuel composition containing distillate fuel, said detergent additive and an additive that improves cold flow, either without deteriorating the cold flow of the composition, or with a lower degree of deterioration of cold flow compared to that which could be caused by an increase in the concentration of the washing additive , which includes introducing into the specified composition an additional additive selected from:
(a) acids and mixtures thereof; and
(b) lubricity improvers. 4. A method of obtaining a fuel composition, which includes:
(i) co-mixing distillate fuel, detergent, and cold flow improver, (ii) measuring the cold flow of the resulting mixture, and (iii) introducing an additional additive selected from:
(a) acids and mixtures thereof; and
(b) lubricity improvers that contain one or more carboxylic acids in an amount sufficient to improve the cold flow of the mixture. 5. A method of reducing the amount of cold flow improver in a fuel composition comprising a distillate fuel, a detergent additive and said cold flow improver, which comprises introducing an additional additive selected from:
(a) acids and mixtures thereof; and
(b) lubricity improvers that contain one or more carboxylic acids. 6. The method according to claim 1, in which the distillate fuel is a medium-distillate fuel. 7. The method according to claim 2, in which the distillate fuel is a medium-distillate fuel. 8. The method according to claim 3, in which the distillate fuel is a medium-distillate fuel. 9. The method according to claim 4, in which the distillate fuel is a medium-distillate fuel. 10. The method according to claim 5, in which the distillate fuel is a medium-distillate fuel. 11. The method according to claim 1, wherein the fuel composition is a diesel fuel composition. 12. The method according to claim 2, in which the fuel composition is a diesel fuel composition. 13. The method according to claim 3, in which the fuel composition is a diesel fuel composition. 14. The method according to claim 4, in which the fuel composition is a diesel fuel composition. 15. The method according to claim 5, in which the fuel composition is a diesel fuel composition. 16. The method according to claim 1, in which the additional additive is selected from acids and mixtures thereof and preferably is a carboxylic acid or a mixture thereof. 17. The method according to claim 2, in which the additional additive is selected from acids and mixtures thereof and preferably is a carboxylic acid or a mixture thereof. 18. The method according to claim 3, in which the additional additive is selected from acids and mixtures thereof and preferably is a carboxylic acid or a mixture thereof. 19. The method according to claim 4, in which the additional additive is selected from acids and mixtures thereof and preferably is a carboxylic acid or a mixture thereof. 20. The method according to claim 5, in which the additional additive is selected from acids and mixtures thereof and preferably is a carboxylic acid or a mixture thereof. 21. The method according to clause 16, in which the additional additive is a fatty acid or a mixture of fatty acids. 22. The method according to 17, in which the additional additive is a fatty acid or a mixture of fatty acids. 23. The method according to p, in which the additional additive is a fatty acid or a mixture of fatty acids. 24. The method according to claim 19, in which the additional additive is a fatty acid or a mixture of fatty acids. 25. The method according to claim 20, in which the additional additive is a fatty acid or a mixture of fatty acids. 26. A method of operating a fuel consuming system, which comprises introducing into the system a fuel composition obtained by the method of claim 4.