AU2014234560A1 - Use of a hydrocarbyl-substituted dicarboxylic acid for improving or boosting the separation of water from fuel oils which comprises detergent additive - Google Patents

Abstract

Use of a hydrocarbyl-substituted dicarboxylic acid for improving or boosting the separation of water from fuel oils which comprise additives with detergent action. A Fuel additive concentrate comprising the said hydrocarbyl-substituted dicarboxylic acid, certain additives with detergent action and optionally dehazers, cetane number improvers and solvents or diluents.

Description

WO 2014/146928 PCT/EP2014/054636 USE OF A HYDROCARBYL-SUBSTITUTED DICARBOXYLIC ACID FOR IMPROVING OR BOOSTING THE SEPARATION OF WATER FROM FUEL OILS WHICH COMPRISES DETERGENT ADDITIVE Description 5 The present invention relates to the use of a hydrocarbyl-substituted dicarboxylic acid compris ing at least one hydrocarbyl substituent of from 10 to 3000 carbon atoms for improving or boost ing the separation of water from fuel oils which comprise (B) at least one additive with detergent action. 10 Fuel oils such as middle distillates, e.g. diesel fuels, heating oils or jet fuels, often contain small amounts of water, typically in the region of from several parts per millions up to several per cent by weight, due to condensation of water into the cold fuel oils and into the storage tanks and pipelines during transport and storage. This amount of water partly separates as a layer at the 15 bottom of the storage tank and partly is emulsified in the fuel oil. The presence of water is unde sired as it can cause severe problems on transport and on use in combustion engines and heat ing devices. German laid open Patent Application 1 645 705 (1) discloses to use of amides of carboxylic 20 acids to dehaze hydrocarbon mixtures, e.g. heating oil and diesel fuel. No hint is given to any possible interactions or synergistic interactions of the said amides with further middle distillate performance additives such as additives with detergent action or further additives with dehazing action. As the teaching of (1) refers to dehaze the hydrocarbon mixtures, i.e. to clear them up by generating hydrocarbon-water-emulsions, such technical solution may only work with relatively 25 small amounts of water; this method will fail with larger amounts of water. Chinese Patent Application 102277212 A (2) relates to a diesel performance additive which is a mixture of tall oil fatty acids, an oleic acid amide and a naphthenic acid imidazoline. The said three-component additive is recommended as an emulsifying agent to dehaze and clear up die 30 sel fuels. Similar to (1) above, no hint is given to any possible interactions or synergistic interac tions of the said amides with further middle distillate performance additives such as additives with detergent action or further additives with dehazing action. As the teaching of (2) also refers to dehaze the diesel fuels, i.e. to clear them up by generating hydrocarbon-water-emulsions, such technical solution may only work with relatively small amounts of water; this method will fail 35 with larger amounts of water. U.S. Patent No. 4 129 508 (3) discloses reaction products of hydrocarbyl-substituted succinic acids or their anhydrides with polyalkylene glycols or their monoethers, organic alkaline metal salts and alkoxylated amines. Such reaction products act as demulsifiers in fuels like diesel fuel. 40 Canadian Patent Application 2 027 269 (4) discloses reaction products of alkenyl or alkyl suc cinic acids or their anhydrides, exhibiting at most 32 carbon atoms in the alkyenyl or alkyl sub stituent, respectively, with alkylether diamines. Such reaction products act as dehazers in hy drocarbon fuels.

WO 2014/146928 PCT/EP2014/054636 2 "Dehazing" as referred to in several of the cited documents above and as generally understood in the art shall mean clearing up water-containing hydrocarbons or diesel fuels, respectively, by generating clear hydrocarbon-water-emulsions ("emulsification") and shall not include separat ing water in separate phase ("demulsification"), thus enabling to remove the water by phase 5 separation. There is a need to separate also larger amounts of water from fuel oils using suitable additive which are capable of completely or practically completely remove the water from the fuel oils. Such additives should interact with other performance additives present in the fuel oils in an 10 advantageous way. Especially, the tendency of modern additives with detergent action to sup port the undesired formation and stabilization of fuel oil-water-emulsions should be counteract ed. Accordingly, the above defined use of a hydrocarbyl-substituted dicarboxylic acid (A) for improv 15 ing or boosting the separation of water from fuel oils comprising one or more additives with de tergent action has been found. According to the present invention, water present in the fuel oils is separated as a layer at the bottom of a separation device and, thereafter, can be easily removed. The water content in fuel 20 oils which can be removed in this way is normally from about 200 ppm by weight to about 10% by weight, especially from about 1000 ppm by weight to about 5% by weight. Emulsifying water in the fuel oil by interaction with the hydrocarbyl-sub-stituted dicarboxylic acid (A) occurs only to a negligible minor amount. 25 According to the present invention, the hydrocarbyl-substituted dicarboxylic acid (A) improves and completes the phase separation of water from the fuel oils which occurs with larger amounts of water present in the fuel oils already without any performance additive but in an in complete way. Furthermore, (A) boosts the phase separation of water from fuel oils if other sur face active additives, especially certain commercially available dehazers, are already present in 30 the fuel oils. Astonishingly, the interaction between (A) and certain commercially available dehazers which are by nature emulsi-fying additives also leads to an improved demulsifying and water phase separating action. The hydrocarbyl-substituted dicarboxylic acid (A) is applied in the form of the free acid, i.e. two 35 COOH groups are present, or in the form of the anhydride which may be an intramolecular an hydride (like succinic anhydride, glutaric anhydride or phthalic anhydride) or an intermolecular anhydride linking two dicarboxylic acid molecules together. To a minor extent, some of the car boxylic functions may be present in salt form, e.g. as alkali or alkaline metal salts salts or as ammonium or substituted ammonium salts, depending on the pH value of the liquid phase. A 40 single hydrocarbyl-substituted dicarboxylic acid species (A) or a mixture of different hydrocarbyl substituted dicarboxylic acids (A) may be used.

WO 2014/146928 PCT/EP2014/054636 3 The hydrocarbyl substituent to the instant dicarboxylic acids preferably exhibits from 12 to 2000, more preferably from 14 to 1000, still more preferably from 16 to 500, most preferably from 20 to 200 carbon atoms. The hydrocarbyl substituent may be saturated or unsaturated, linear or branched; it may also include alicyclic, heterocyclic or aro-matic ring systems. Typical examples 5 of hydrocarbyl substituents include linear and branched alkyl and alkenyl radical with 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 26, 28 and 30 carbon atoms in the chain. In many cases such hydrocarbyl substituents are synthetically produced by oligomeri-zation or polymerization of olefin monomers such as ethene, propene, 1-butene, 2-butene, isobutene, 1 10 penten, 1-hexen, 1-octen or 1-decen; follow-up transformations of such oligomerization or polymerization products may be applied. As typical examples, dodecyl or dodecenyl substitu ents are produced by tetramerization of propene or trimerization of butenes and tridecyl or tride cenyl substituents are made from the aforementioned C 12 -substituents by subsequent hydro formylation. 15 In case of substituents with 10 to about 30 carbon atoms, such substituents may also be of nat ural origin. Substituents of natural origin are normally derived from saturated or unsaturated fatty acids or the corresponding fatty alcohols. Such substituents of natural origin are in most cases linear. 20 In a preferred embodiment, the at least one hydrocarbyl substituent of (A) is a polyisobutenyl substituent comprising from 20 to 200, preferably from 24 to 160, more preferably from 28 to 140, most preferably from 32 to 100 carbon atoms. As an alternative when considering a possi ble distribution of homologous polymer species, the length of the polyisobutenyl substituent can 25 be defined by its number average molecular weight (Mn) of from 300 to 2800, preferably of from 350 to 2300, more preferably of from 400 to 2000, most preferably of from 450 to 1400; such Ma numbers normally relate to a polydispersity (Mw/Mn) of from 1.1 to 4, preferably of from 1.3 to 2.5. A typical polyisobutenyl substitutent comprises from 60 to 80 carbon atoms or is defined by a number average molecular weight of from 850 to 1150. 30 Depending on the way of synthesizing the polyisobutenyl-substitutend dicarboxylic acid and attaching the polyisobutenyl substituent to the dicarboxylic acid molecule, i.e. to the bridging group between the two carboxylic functions, the polyisobutenyl substituent may be saturated, e.g. when attaching a polyisobutyl halide to an aromatic dicarboxylic acid (such as phthalic acid) 35 via Friedel-Crafts reaction or to an olefinically unsaturated dicarbocylic acid (such as maleic acid or maleic anhydride), or may contain an olefinic double bond next to the link-up to the di carboxylic acid molecule, e.g. when attaching a polyisobuten molecule with a terminal double bond to an olefinically unsaturated dicarbocylic acid (such as maleic acid or maleic anhydride) via en reaction. 40 The hydrocarbyl-substituted dicarboxylic acid (A) itself may be of aliphatic, cycloalipha-tic, arali phatic or aromatic nature, aliphatic dicarboxylic acids being preferred. Typical hydrocarbyl- WO 2014/146928 PCT/EP2014/054636 4 substituted dicarboxylic acids (A) suitable for the present invention are derived from hydro carbyl-substituted malonic acid, hydrocarbyl-substituted succinic acid, hydrocarbyl-substituted glutaric acid, hydrocarbyl-substituted adipic acid, hydro-carbyl-substituted pimelic acid, hydro carbyl-substituted suberic acid, hydrocarbyl-substituted azelaic acid, hydrocarbyl-substituted 5 sebacic acid, hydrocarbyl-substituted undecanedioic acid, hydrocarbyl-substituted dodecanedio ic acid, hydrocarbyl-substi-tuted phthalic acid, hydrocarbyl-substituted isophthalic acid, hydro carbyl-substituted terephthalic acid, hydrocarbyl-substituted o-, m- or p-phenylene diacetic acid, hydro-carbyl-substituted maleic acid, hydrocarbyl-substituted fumaric acid and hydrocarbyl substituted glutaconic acid. 10 In a preferred embodiment, the hydrocarbyl-substituted dicarboxylic acid (A) comprises a hy drocarbylene bridging group between the two carboxylic functions of from 1 to 10, preferably of from 2 to 8, more preferably of from 2 to 6, most preferably of 2, 3 or 4 carbon atoms in a line. Such bridging carbon atom line may be a linear aliphatic alkylene or alkenylene chain with or 15 without Cl- to C 4 -side chains, an araliphatic bridging group incorporating a benzene ring into the aliphatic carbon atom chain, or a phenylene bridging group. In an especially preferred embodiment, the hydrocarbyl-substituted dicarboxylic acid (A) is a polyisobutenylsuccinic acid with one polyisobutenyl substituent comprising from 20 to 200, pref 20 erably from 24 to 160, more preferably from 28 to 140, most preferably from 32 to 100 carbon atoms or, as an alternative, with a polyisobutenyl with a number average molecular weight (Mn) of from 300 to 2800, preferably of from 350 to 2300, more preferably of from 400 to 2000, most preferably of from 450 to 1400. Such preferred polyisobutenylsuccinic acid may also be applied according to the present invention in the form of the polyisobutenylsuccinic anhydride. 25 Polyisobutenylsuccinic acids with two free COOH functions which are suitable for use of water separation from fuel oils according the present invention can be easily prepared in dry sub stance by hydrolysis of the corresponding anhydrides, i.e. by simply mixing the said anhydrides with the equimolar amount of water and heating up to a temperature of from about 70'C to 30 about 120'C for a sufficient time period (usually from 2 to 20 hours). Additives with detergent action of component (B) refer, in the context of the present invention, to those compounds whose effect in an internal combustion engine or in a heating device, espe cially a diesel engine, consists predominantly or at least essentially of eliminating and/or pre 35 venting deposits. The detergents are preferably amphiphilic substances which have at least one hydrophobic hydrocarbyl radical having a number-average molecular weight (Mn) of 85 to 20.000, especially of 300 to 5000, and in particular of 500 to 2500, and at least one polar moie ty. 40 In a preferred embodiment of the present invention, the fuel oils comprise at least one additive component with detergent action (B) which is selected from WO 2014/146928 PCT/EP2014/054636 5 (i) compounds with moieties derived from succinic anhydride and having hydroxyl and/or amino and/or amido and/or imido groups; (ii) nitrogen compounds quaternized in the presence of an acid or in an acid-free manner, 5 obtainable by addition of a compound comprising at least one oxygen- or nitrogen containing group reactive with an anhydride and additionally at least one quaternizable amino group onto a polycarboxylic anhydride compound and subsequent quaternization; (iii) polytetrahydrobenzoxazines and bistetrahydrobenzoxazines. 10 Additives (i) comprising moieties deriving from succinic anhydride and having hydroxyl and/or amino and/or amido and/or imido groups are preferably corresponding derivatives of polyisobu tenylsuccinic anhydride, which are obtainable by reaction of conventional or high-reactivity poly isobutene with Mn = 300 to 5000, in particular with Mn = 500 to 2500, with maleic anhydride by a 15 thermal route or via the chlorinated polyisobutene. Of particular interest in this context are de rivatives with aliphatic polyamines such as ethylenediamine, diethylenetriamine, triethylenetet ramine or tetraethylenepentamine. The moieties with hydroxyl and/or amino and/or amido and/or imido groups are for example carboxylic acid groups, acid amides, acid amides of di- or polyamines, which, as well as the amide function, also have free amine groups, succinic acid 20 derivatives with an acid and an amide function, carboxyimides with monoamines, carboxyimides with di- or polyamines, which, as well as the imide function, also have free amine groups, and diimides, which are formed by the reaction of di- or polyamines with two succinic acid deriva tives. Such fuel additives are described especially in US-A 4 849 572. 25 Nitrogen compounds quaternized in the presence of an acid or in an acid-free manner accord ing to the above group (ii) are obtainable by addition of a compound which com-prises at least one oxygen- or nitrogen-containing group reactive with an anhydride and additionally at least one quaternizable amino group onto a polycarboxylic anhydride compound and subsequent quaternization, especially with an epoxide, e.g. styrene or propylene oxide, in the absence of 30 free acid, as described in WO 2012/004300, or with a carboxylic ester, e.g. dimethyl oxalate or methyl salicylate. Suitable compounds having at least one oxygen- or nitrogen-containing group reactive with anhydride and additionally at least one quaternizable amino group are especially polyamines having at least one primary or secondary amino group and at least one tertiary ami no group. Useful polycarboxylic anhydrides are especially dicarboxylic acids such as succinic 35 acid, having a relatively long-chain hydrocarbyl substituent, preferably having a number average molecular weight Mn for the hydrocarbyl substituent of 200 to 10.000, in particular of 350 to 5000. Such a quaternized nitrogen compound is, for example, the reaction product, ob tained at 40'C, of polyisobutenylsuccinic anhydride, in which the polyisobutenyl radical typically has an Mn of 1000, with 3-(dimethylamino)propylamine, which constitutes a polyisobutenylsuc 40 cinic monoamide and which is subsequently quaternized with dimethyl oxalate or methyl salicy late or with styrene oxide or propylene oxide in the absence of free acid.

WO 2014/146928 PCT/EP2014/054636 6 Further nitrogen compounds according to the above group (ii) are described in WO 2006/135881 Al, page 5, line 13 to page 12, line 14; WO 10/132259 Al, page 3, line 28 to page 10, line 25; WO 2008/060888 A2, page 6, line 15 to page 14, line 29; 5 WO 2011/095819 A1, page 4, line 5 to page 9, line 29; GB 2496514 A, paragraph [00012] to paragraph [00041]; WO 2013/117616 A1, page 3, line 34 to page 11, line 2; the unpublished European Patent application with the file number 13172841.2, application date June 19, 2013, page 3, line 14 to page 5, line 9; 10 the unpublished European Patent application with the file number 13171057.6, application date June 7, 2013, page 5, lines 28 to 35 and page 13, line 8 to page 17, line 28; the unpublished European Patent application with the file number 13185288.1, application date September 20, 2013, page 4, line 35 to page 5, line 10 and page 13, line 27 to page 21, line 2; the unpublished International Patent application with the file number PCT/EP2013/072169, ap 15 plication date October 23, 2013, page 5, line 18 to page 6, line 18 and page 15, line 26 to page 19, line 17; WO 2013/064689 Al, page 18, line 16 to page 29, line 8; and WO 2013/087701 Al, page 13, line 25 to page 19, line 30, each of which is incorporated herein by reference. 20 Polytetrahydrobenzoxazines and bistetrahydrobenzoxazines according to the above group (iii) are described in WO 2012/076428. Such polytetrahydro-benzoxazines and bistetrahydroben zoxazines are obtainable by successively reacting, in a first reaction step, a C1- to C 20 alkylenediamine having two primary amino functions, e.g. 1,2-ethylenediamine, with a C 1 - to 25 C 12 -aldehyde, e.g. formaldehyde, and a C 1 - to C 8 -alkanol at a temperature of 20 to 80'C with elimination and removal of water, where both the aldehyde and the alcohol can each be used in more than twice the molar amount, especially in each case in 4 times the molar amount, relative to the diamine, in a second reaction step reacting the condensation product thus obtained with a phenol which bears at least one long-chain substituent having 6 to 3000 carbon atoms, e.g. a 30 tert-octyl, n-nonyl, n-dodecyl or polyisobutyl radical having an Mn of 1000, in a stoichiometric ratio relative to the originally used alkylenediamine of 1.2:1 to 3:1 at a temperature of 30 to 120'C and optionally in a third reaction step heating the bistetrahydrobenzoxazine thus ob tained to a temperature of 125 to 280'C for at least 10 minutes. 35 Within the scope of the present invention, the hydrocarbyl-substituted dicarboxylic acid (A) is preferably used together with quarternized nitrogen compounds (ii) for compo-nent (B). Furthermore, the present hydrocarbyl-substituted dicarboxylic acid (A) and the at least one addi tive with detergent action for component (B) exhibit superior performance - even in the sense of 40 synergism - in improving and/or boosting the separation of water from fuel oils when applied together with at least one dehazer exhibiting emulsifying action on its own when used alone as additive component (C) selected from WO 2014/146928 PCT/EP2014/054636 7 (iv) alkoxylation copolymers of ethylene oxide, propylene oxide, butylene oxide, styrene oxide and/or other oxides, e.g. epoxy based resins; (v) alkoxylated phenol formaldehyde resins. 5 Dehazer components (iv) and (v) are normally commercially available products, e.g. the dehaz er products available from Baker Petrolite under the brand name of Tolad@ such as Tolad@ 2898, 9360K, 9348, 9352K or 9327. 10 In a further preferred embodiment of the present invention, the fuel oils additionally comprise as additive component (D) at least on cetane number improver. Cetane number improvers used are typically organic nitrates. Such organic nitrates are especially nitrate esters of unsubstituted or substituted aliphatic or cycloaliphatic alcohols, usually having up to about 10, in particular having 2 to 10 carbon atoms. The alkyl group in these nitrate esters may be linear or branched, 15 and saturated or unsaturated. Typical examples of such nitrate esters are methyl nitrate, ethyl nitrate, n-propyl nitrate, isopropyl nitrate, allyl nitrate, n-butyl nitrate, isobutyl nitrate, sec-butyl nitrate, tert-butyl nitrate, n-amyl nitrate, isoamyl nitrate, 2-amyl nitrate, 3-amyl nitrate, tert-amyl nitrate, n-hexyl nitrate, n-heptyl nitrate, sec-heptyl nitrate, n-octyl nitrate, 2-ethylhexyl nitrate, sec-octyl nitrate, n-nonyl nitrate, n-decyl nitrate, cyclopentyl nitrate, cyclohexyl nitrate, methylcy 20 clohexyl nitrate and isopropylcyclohexyl nitrate and also branched decyl nitrates of the formula

R

1

R

2

CH-CH

2

-O-NO

2 in which R 1 is an n-propyl or isopropyl radical and R 2 is a linear or branched alkyl radical having 5 carbon atoms, as described in WO 2008/092809. Additionally suitable are, for example, nitrate esters of alkoxy-substituted aliphatic alcohols such as 2 ethoxyethyl nitrate, 2-(2-ethoxy-ethoxy)ethyl nitrate, 1 -methoxypropyl nitrate or 4-ethoxybutyl 25 nitrate. Additionally suitable are also diol nitrates such as 1,6-hexamethylene dinitrate. Among the cetane number improver classes mentioned, preference is given to primary amyl nitrates, primary hexyl nitrates, octyl nitrates and mixtures thereof. Most preferably, 2-ethylhexyl nitrate is present in the fuel oils as the sole cetane number improver or in a mixture with other cetane number improvers. 30 In the context of the present invention, fuel oils means preferably middle distillate fuels, espe cially diesel fuels. However, heating oils, jet fuels and kerosene shall also be encompassed. Diesel fuels or middle distillate fuels are typically mineral oil raffinates which generally have a boiling range from 100 to 400'C. These are usually distillates having a 95% point up to 360'C or 35 even higher. However, these may also be what is called "ultra low sulfur diesel" or "city diesel", characterized by a 95% point of, for example, not more than 345'C and a sulfur content of not more than 0.005% by weight, or by a 95% point of, for example, 285'C and a sulfur content of not more than 0.001% by weight. In addition to the diesel fuels obtainable by refining, the main constituents of which are relatively long-chain paraffins, those obtainable in a synthetic way by 40 coal gasification or gas liquefaction ["gas to liquid" (GTL) fuels] are suitable, too. Also suitable are mixtures of the aforementioned diesel fuels with renewable fuels (biofuel oils) such as bio diesel or bioethanol. Of particular interest at present are diesel fuels with low sulfur content, i.e.

WO 2014/146928 PCT/EP2014/054636 8 with a sulfur content of less than 0.05% by weight, preferably of less than 0.02% by weight, par ticularly of less than 0.005% by weight and especially of less than 0.001% by weight of sulfur. In a preferred embodiment, the hydrocarbyl-substituted dicarboxylic acid (A) is used together 5 with the aforementioned components (B), (C) and, if desired (D), in fuel oils which consist (a) to an extent of 0.1 to 100% by weight, preferably to an extent of 0.1 to less than 100% by weight, especially to an extent of 10 to 95% by weight and in particular to an extent of 30 to 90% by weight, of at least one biofuel oil based on fatty acid esters, and 10 (b) to an extent of 0 to 99.9% by weight, preferably to an extent of more than 0 to 99.9% by weight, especially to an extent of 5 to 90% by weight, and in particular to an extent of 10 to 70% by weight, of middle distillates of fossil origin and/or of synthetic origin and/or of vegetable and/or animal origin, which are essentially hydrocarbon mixtures and are free of 15 fatty acid esters. The hydrocarbyl-substituted dicarboxylic acid (A) can also be used together with the aforemen tioned components (B), (C) and, if desired (D), in fuel oils which consist exclusively of middle distillates of fossil origin and/or of synthetic origin and/or of vegetable and/or animal origin, 20 which are essentially hydrocarbon mixtures and are free of fatty acid esters. Fuel oil component (a) is usually also referred to as "biodiesel". This preferably com-prises es sentially alkyl esters of fatty acids which derive from vegetable and/or animal oils and/or fats. Alkyl esters typically refer to lower alkyl esters, especially C 1 - to C 4 -alkyl esters, which are ob 25 tainable by transesterifying the glycerides which occur in vegetable and/or animal oils and/or fats, especially triglycerides, by means of lower alcohols, for example, ethanol, n-propanol, iso propanol, n-butanol, isobutanol, sec-butanol, tert-butanol or especially methanol ("FAME"). Examples of vegetable oils which can be converted to corresponding alkyl esters and can thus 30 serve as the basis of biodiesel are castor oil, olive oil, peanut oil, palm kernel oil, coconut oil, mustard oil, cottonseed oil, and especially sunflower oil, palm oil, soybean oil and rapeseed oil. Further examples include oils which can be obtained from wheat, jute, sesame and shea tree nut; it is additionally also possible to use arachis oil, jatropha oil and linseed oil. The extraction of these oils and the conversion thereof to the alkyl esters are known from the prior art or can 35 be inferred therefrom. It is also possible to convert already used vegetable oils, for example used deep fat fryer oil, optionally after appropriate cleaning, to alkyl esters, and thus for them to serve as the basis of biodiesel. 40 Vegetable fats can in principle likewise be used as a source for biodiesel, but play a minor role.

WO 2014/146928 PCT/EP2014/054636 9 Examples of animal oils and fats which can be converted to corresponding alkyl esters and can thus serve as the basis of biodiesel are fish oil, bovine tallow, porcine tallow and similar fats and oils obtained as wastes in the slaughter or utilization of farm animals or wild animals. 5 The parent saturated or unsaturated fatty acids of said vegetable and/or animal oils and/or fats, which usually have 12 to 22 carbon atoms and may bear an additional functional group such as hydroxyl groups, and which occur in the alkyl esters, are especially lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, elaidic acid, erucic acid and/or ricinoleic acid. 10 Typical lower alkyl esters based on vegetable and/or animal oils and/or fats, which find use as biodiesel or biodiesel components, are, for example, sunflower methyl ester, palm oil methyl ester ("PME"), soybean oil methyl ester ("SME") and especially rapeseed oil methyl ester ("RME"). 15 However, it is also possible to use the monoglycerides, diglycerides and especially triglycerides themselves, for example castor oil, or mixtures of such glycerides, as biodiesel or components for biodiesel. 20 In the context of the present invention, the fuel oil component (b) shall be understood to mean the abovementioned middle distillate fuels, especially diesel fuels, especially those which boil in the range from 120 to 450'C. In a further preferred embodiment, the hydrocarbyl-substituted dicarboxylic acid (A) is used to 25 gether with the aforementioned components (B), (C) and, if desired (D), in fuel oils which have at least one of the following properties: (a) a sulfur content of less than 50 mg/kg (corresponding to 0.005% by weight), especially less than 10 mg/kg (corresponding to 0.001% by weight); 30 (p3) a maximum content of 8% by weight of polycyclic aromatic hydrocarbons; (y) a 95% distillation point (vol/vol) at not more than 360'C. 35 Polycyclic aromatic hydrocarbons in (P) shall be understood to mean polyaromatic hydrocar bons according to standard EN 12916. They are determined according to this standard. The fuel oils comprise said hydrocarbyl-substituted dicarboxylic acid (A) in the context of the present invention generally in an amount of from 1 to 1000 ppm by weight, preferably of from 5 40 to 500 ppm by weight, more preferably of from 3 to 300 ppm by weight, most preferably of from 5 to 200 ppm by weight, for example of from 10 to 100 ppm by weight.

WO 2014/146928 PCT/EP2014/054636 10 The additive with detergent action (B) or a mixture of a plurality of such additives with detergent action is present in the fuel oils typically in an amount of from 10 to 2000 ppm by weight, prefer ably of from 20 to 1000 ppm by weight, more preferably of from 50 to 500 ppm by weight, most preferably of from 30 to 250 ppm by weight, for example of from 50 to 150 ppm by weight. 5 One or more dehazers as additive component (C), if any, are present in the fuel oils generally in an amount of from 0.5 to 100 ppm by weight, preferably of from 1 to 50 ppm by weight, more preferably of from 1.5 to 40 ppm by weight, most preferably of from 2 to 30 ppm by weight, for example of from 3 to 20 ppm by weight. 10 The cetane number improver (D) or a mixture of a plurality of cetane number improvers is pre sent in the fuel oils normally in an amount of form 10 to 10.000 ppm by weight, preferably of from 20 to 5000 ppm by weight, more preferably of from 50 to 2500 ppm by weight, most pref erably of from 100 to 1000 ppm by weight, for example of from 150 to 500 ppm by weight. 15 Subject matter of the present invention is also a fuel additive concentrate suitable for use in fuel oils, especially in diesel fuel, comprising (A) 0.01 to 40% by weight, preferably 0.05 to 20% by weight, more preferably 0.1 to 20 10% by weight, of a hydrocarbyl-substituted dicarboxylic acid comprising at least one hydrocarbyl substituent of from 10 to 3000 carbon atoms; (B) 5 to 40% by weight, preferably 10 to 35% by weight, more preferably 15 to 30% by weight, of at least one additive with detergent action selected from 25 (i) compounds with moieties derived from succinic anhydride and having hydroxyl and/or amino and/or amido and/or imido groups; (ii) nitrogen compounds quaternized in the presence of an acid or in an acid 30 free manner, obtainable by addition of a compound comprising at least one oxygen- or nitrogen-containing group reactive with an anhydride and additionally at least one quaternizable amino group onto a polycarboxylic anhydride compound and subsequent quaternization; 35 (iii) polytetrahydrobenzoxazines and bistetrahydrobenzoxazines; (C) 0 to 5% by weight, preferably 0.01 to 5 by weight, more preferably 0.02 to 3.5% by weight, most preferably 0.05 to 2% by weight, of at least one dehazer selected from 40 (iv) alkoxylation copolymers of ethylene oxide, propylene oxide, butylene oxide, styrene oxide and/or other oxides, e.g. epoxy based resins WO 2014/146928 PCT/EP2014/054636 11 (v) alkoxylated phenol formaldehyde resins; (D) 0 to 75% by weight, preferably 5 to 75% by weight, more preferably 10 to 70% by 5 weight, of at least one cetane number improver; (E) 0 to 50% by weight, preferably 5 to 50% by weight, more preferably 10 to 40% by weight, of at least one solvent or diluent. 10 In each case, the sum of components (A), (B), (C), (D) and (E) results in 100%. Said fuel oils such as diesel fuels, or said mixtures of biofuel oils and middle distillates of fossil, synthetic, vegetable or animal origin, may comprise, in addition to the hydro-carbyl-substituted dicarboxylic acid (A) and components (B) and, if any (C) and (D), as coadditives further custom 15 ary additive components in amounts customary therefor, especially cold flow improvers, corro sion inhibitors, further demulsifiers, antifoams, antioxidants and stabilizers, metal deactivators, antistats, lubricity improvers, dyes (markers) and/or diluents and solvents. Said fuel additive concentrates may also comprise certain of the above coadditives in amounts customary there for, e.g. corro-sion improvers, further demulsifiers, antifoams, antioxidants and stabilizers, metal 20 deactivators, antistats and lubricity improvers. Cold flow improvers suitable as further coadditives are, for example, copolymers of ethylene with at least one further unsaturated monomer, in particular ethylene-vinyl acetate copolymers. 25 Corrosion inhibitors suitable as further coadditives are, for example, succinic esters, in particular with polyols, fatty acid derivatives, for example oleic esters, oligomerized fatty acids and substi tuted ethanolamines. Further demulsifiers suitable as further coadditives are, for example, the alkali metal and alka 30 line earth metal salts of alkyl-substituted phenol- and naphthalenesulfonates and the alkali met al and alkaline earth metal salts of fatty acids, and also alcohol alkoxylates, e.g. alcohol ethox ylates, phenol alkoxylates, e.g. tert-butylphenol ethoxylates or tert-pentylphenol ethoxylates, fatty acids themselves, alkylphenols, condensation products of ethylene oxide and propylene oxide, e.g. ethylene oxide-propylene oxide block copolymers, polyethyleneimines and polysilox 35 anes. Antifoams suitable as further coadditives are, for example, polyether-modified poly-siloxanes. Antioxidants suitable as further coadditives are, for example, substituted phenols, e.g. 2,6-di 40 tert-butylphenol and 2,6-di-tert-butyl-3-methylphenol, and also phenylene-diamines, e.g. N,N'-di sec-butyl-p-phenylenediamine.

WO 2014/146928 PCT/EP2014/054636 12 Metal deactivators suitable as further coadditives are, for example, salicylic acid derivatives, e.g. N,N'-disalicylidene-1,2-propanediamine. A lubricity improver suitable as a further coadditive is, for example, glyceryl mono-oleate. 5 Suitable solvents and diluents as component (E), especially for diesel performance packages, are, for example, nonpolar organic solvents, especially aromatic and aliphatic hydrocarbons, for example toluene, xylenes, "white spirit" and the technical solvent mixtures of the designations Shellsolo (manufactured by Royal Dutch/Shell Group), Exxol@ (manu-factured by ExxonMobil) 10 and Solvent Naphtha. Also useful here, especially in a blend with the nonpolar organic solvents mentioned, are polar organic solvents, in particular alcohols such as 2-ethylhexanol, decanol and isotridecanol. The examples which follow are intended to illustrate the present invention without restricting it. 15 Examples For evaluating the capability of the present hydrocarbyl-substituted dicarboxylic acid (A) of sep arating water from diesel fuels containing an additive with detergent action, the corresponding 20 standard test method according to ASTM D 1094 was applied. For this test, a glass cylinder was filled with 20 ml of water buffer and 80 ml of the diesel fuel and then shaken for 2 minutes. After the emulsion generated has been allowed to settle for a fixed period of time (5 minutes), the quantities (volumes) of the water loss and the time for 15 ml of water separation were de termined. 25 The test was carried through in a commercially available diesel fuel composed of 100% of mid dle distillates of fossil origin ("DF1") an in a commercially available biodiesel containing diesel fuel composed of 95% by weight of middle distillates of fossil origin and 5% by weight of FAME ("DF2"). 30 Two different hydrocarbyl-substituted dicarboxylic acids (A) were used: Al was polyisobuten ylsuccinic acid and A2 was polyisobutenylsuccinic anhydride. A2 was prepared by thermal en reaction between polyisobuten (having an Mn of 1000 and a content of 70 mol-% of terminal vinylidene double bonds) and maleic anhydride; Al was prepared by hydrolysis of A2 with the 35 equimolar amount of water at 1 00 0 C for 16 hours. Al or A2, respectively, was admixed to a usual diesel detergent package comprising as compo nent (B)(ii) the imide reaction product of polyisobutenylsuccinic anhydride, in which the polyiso butenyl radical has an Mn of 1000, with 3-(dimethylamino)propylamine which is subsequently 40 quaternized with methyl salicylate, as component (C)(v) a dehazer commercially available from Baker Petrolite under the name of Tolad@ 2898 and a commercially available polyether- WO 2014/146928 PCT/EP2014/054636 13 modified polysiloxane antifoam ("AF"). The concentration of said compounds A1/A2, (B)(ii), (C)(v) and AF in the fuel/water test system are given in the table below. The following table shows the results of the determinations: 5 Example Additives used with concentration [wt.-ppm] Fuel (A) (B)(ii) (C)(v) AF 1a 0 24 2.5 5 DF1 10 1b Al: 5 24 2.5 5 DF1 1c A2: 5 24 2.5 5 DF1 2a 0 24 2.5 5 DF2 2b Al: 5 24 2.5 5 DF2 15 2c A2: 5 24 2.5 5 DF2 Evaluation: Example Water loss 15 ml water separation after 5 minutes [ml] after [sec] 20 la 8 336 lb 0 200 1c 1 220 25 2a 20 655 2b 10 440 2c 5 300

Claims (11)

1. The use of (A) a hydrocarbyl-substituted dicarboxylic acid comprising at least one hydro carbyl substituent of from 10 to 3000 carbon atoms for improving or boosting the separation 5 of water from fuel oils which comprise (B) at least one additive with detergent action.

2. The use according to Claim 1, in which the at least one hydrocarbyl substituent of (A) is a polyisobutenyl substituent comprising from 20 to 200 carbon atoms. 10

3. The use according to Claim 1, in which the hydrocarbyl-substituted dicarboxylic acid (A) comprising a hydrocarbylene bridging group between the two carboxylic functions from 1 to 10 carbon atoms in a line.

4. The use according to Claims 1 to 3, in which the hydrocarbyl-substituted dicarboxylic acid 15 (A) is a polyisobutenylsuccinic acid with one polyisobutenyl substituent comprising from 20 to 200 carbon atoms.

5. The use according to Claims 1 to 4, in which additive component (B) is selected from 20 (i) compounds with moieties derived from succinic anhydride and having hydroxyl and/or amino and/or amido and/or imido groups; (ii) nitrogen compounds quaternized in the presence of an acid or in an acid free manner, obtainable by addition of a compound comprising at least one 25 oxygen- or nitrogen-containing group reactive with an anhydride and additionally at least one quaternizable amino group onto a polycarboxylic anhydride compound and subsequent quaternization; (iii) polytetrahydrobenzoxazines and bistetrahydrobenzoxazines. 30

6. The use according to Claims 1 to 5, in which the fuel oils additionally comprise as additive component (C) at least on dehazer selected from (iv) alkoxylation copolymers of ethylene oxide, propylene oxide, butylene oxide, 35 styrene oxide and/or other oxides; (v) alkoxylated phenol formaldehyde resins.

7. The use according to Claims 1 to 6, in which the fuel oils additionally comprise as additive 40 component (D) at least one cetane number improver.

8. The use according to Claims 1 to 7, in which the fuel oils consist WO 2014/146928 PCT/EP2014/054636 15 (a) to an extent of 0.1 to 100% by weight of at least one biofuel oil based on fatty acid esters, and (b) to an extent of 0 to 99.9% by weight of middle distillates of fossil origin 5 and/or of synthetic origin and/or of vegetable and/or animal origin, which are essentially hydrocarbon mixtures and are free of fatty acid esters.

9. The use according to Claims 1 to 8, in which the fuel oils consist exclusively of middle distil lates of fossil origin and/or of synthetic origin and/or of vegetable and/or animal origin, which 10 are essentially hydrocarbon mixtures and are free of fatty acid esters.

10. The use according to Claims 1 to 9, in which the fuel oils have at least one of the following properties: 15 (a) a sulfur content of less than 50 mg/kg; (P) a maximum content of 8% by weight of polycyclic aromatic hydrocarbons; (y) a 95% distillation point (vol/vol) at not more than 360'C. 20

11. A fuel additive concentrate suitable for use in fuel oils, comprising (A) 0.01 to 40% by weight of a hydrocarbyl-substituted dicarboxylic acid comprising at least one hydrocarbyl substituent of from 10 to 3000 carbon 25 atoms; (B) 5 to 40% by weight of at least one additive with detergent action selected from 30 (i) compounds with moieties derived from succinic anhydride and having hydroxyl and/or amino and/or amido and/or imido groups; (ii) nitrogen compounds quaternized in the presence of an acid or in an acid-free manner, obtainable by addition of a compound comprising 35 at least one oxygen- or nitrogen-containing group reactive with an anhydride and additionally at least one quaternizable amino group onto a polycarboxylic anhydride compound and subsequent quaternization; 40 (iii) polytetrahydrobenzoxazines and bistetrahydrobenzoxazines; (C) 0 to 5% by weight of at least on dehazer selected from WO 2014/146928 PCT/EP2014/054636 16 (iv) alkoxylation copolymers of ethylene oxide, propylene oxide, butylene oxide, styrene oxide and/or other oxides; 5 (v) alkoxylated phenol formaldehyde resins; (D) 0 to 75% by weight of at least one cetane number improver; (E) 0 to 50% by weight of at least one solvent or diluent. 10