JP2007308701A - Low-temperature flowability-enhancing agent for vegetable- or animal-derived fuel oil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an additive, use thereof as a low-temperature flowability-enhancing agent for vegetable- or animal-derived fuel oils, and a corresponding fuel oil having incorporated the additive therewith. <P>SOLUTION: The additive for the fuel oil comprises (A) a copolymer of ethylene with 18-35 mol% of at least one of an acrylate and a vinyl ester bearing a 1-18C alkyl radical and having a branching degree of smaller than 5 CH<SB>3</SB>/100 CH<SB>2</SB>group and (B) a comb-shaped polymer having a structural unit formed from monomers below: (B1) at least one olefin, as monomer 1, bearing at least one 8-18C alkyl radical on an olefinic double bond and (B2) at least one ethylenically unsaturated dicarboxylic acid, as monomer 2, bearing at least one 8-16C alkyl radical bonded via an amide and/or imide group, wherein the parameter Q represented by the expression is assumed to have the numerical value of 23-27. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an additive, its use as a cold fluidity improver for plant or animal fuel oils and correspondingly added fuel oils.

Considering the world's crude oil reserves and the debate about the environmentally harmful effects of using fossil and mineral fuels, there is increasing interest in alternative energy sources based on renewable raw materials. These include in particular natural oils and fats of vegetable or animal origin. These are generally triglycerides of fatty acids having 10 to 24 carbon atoms and a calorific value comparable to conventional fuels, but at the same time are considered to be less harmful to the environment. Biofuels, ie fuels derived from animal or plant material, are obtained from renewable sources and, when they are burned, therefore generate as much CO ₂ as they were previously converted to biomass . It is reported that less carbon dioxide is formed in the course of combustion and less sulfur dioxide is formed compared to equivalent amounts of crude distillate fuel, such as diesel fuel. In addition, they are biodegradable.

  Oils obtained from animal or plant materials are mainly metabolites containing monocarboxylic acid triglycerides and have the following formula:

(Wherein R is an aliphatic radical having 10 to 25 carbon atoms and may be saturated or unsaturated.)
It is normal to correspond to.

  Such oils contain glycerides from a range of acids, the acid number and type of acid will vary depending on the source of the oil, and such oils typically may additionally contain phosphoglycerides. . Such oils can be obtained by processes known from the prior art.

  As a result of the unsatisfactory physical properties of triglycerides, the industry has been devoted to converting naturally occurring triglycerides into fatty alcohol esters of lower alcohols such as methanol or ethanol.

  It has been found that the impediment to using triglycerides and also fatty acid esters of lower monohydric alcohols alone or in mixtures with diesel fuel as an alternative to diesel fuel is their fluidity at low temperatures. This is due to the higher uniformity of these oils compared to mineral oil middle distillates. For example, rapeseed oil methyl ester (RME) has a plugging point (CFPP) of -14 ° C. Using prior art additives to reliably achieve the CFPP value of -20 ° C required for use as winter diesel in Central Europe, or CFPP value of -22 ° C or less for special applications, Previously it was impossible. This problem is exacerbated when using oils that contain relatively high amounts of saturated fatty acid esters, such as those present in, for example, sunflower oil methyl ester, spent oil methyl ester or soybean oil methyl ester.

  Biofuels, crude oil-based fuel oils and (a) oil-soluble ethylene copolymers or (b) comb polymers or (c) polar nitrogen compounds or (d) carbon atoms of alkyl groups and one or more non-terminal A compound in which at least one substantially linear alkyl group having 10 to 30 carbon atoms is bound to a non-polymeric organic radical to provide at least one linear chain atom containing an oxygen atom, or (e) A fuel oil composition containing an additive containing at least one of components (a), (b), (c) and (d) is known (Patent Document 1).

A relatively large proportion of an oil consisting essentially of an alkyl ester of a fatty acid derived from vegetable oil or animal oil or both, including one or more of the following: mixed with a small proportion of mineral oil cold flow improver, Compositions are known (Patent Document 2):
(I) Comb polymers, copolymers of maleic anhydride or fumaric acid and another ethylenically unsaturated monomer (which may be esterified), or polymers or copolymers of a-olefins, or fumarate or itaconate polymers or copolymers ,
(II) polyoxyalkylene esters, esters / ethers or mixtures thereof,
(III) ethylene / unsaturated ester copolymer,
(IV) Polar, organic, nitrogen-containing paraffin crystal growth inhibitor,
(V) Hydrocarbon polymer,
(VI) sulfur-carboxyl compounds and
(VII) an aromatic pour point depressant modified with a hydrocarbon radical,
However, the composition does not contain any mixture of polymeric esters of acrylic acid and / or methacrylic acid or copolymers of esters derived from alcohols having 1 to 22 carbon atoms.

Starting from esters of naturally occurring long chain fatty acids with monovalent C ₁ -C ₆ -alcohols (FAE), the following:
a) PPD additives (pour point depressants) known per se and used to improve the low temperature performance of mineral oils are added in an amount of 0.0001-10% by weight, based on the long chain fatty acid ester FAE,
b) Cool the long chain fatty acid ester FAE to which no additives are added to a temperature below the clogging point and
c) A process is known for producing compositions with improved low temperature performance for use as fuels or lubricants, including removing the generated precipitate (FAN) (Patent Document 3).

Mixtures of fatty acid lower alkyl esters with improved low temperature stability are known (Patent Document 4), including:
a) 58-95% by weight of at least one ester having an iodine value in the range of 50-150, derived from a fatty acid having 12-22 carbon atoms and a lower aliphatic alcohol having 1-4 carbon atoms,
b) 4 to 40% by weight of at least one ester of a fatty acid having 6 to 14 carbon atoms and a lower aliphatic alcohol having 1 to 4 carbon atoms and
c) 0.1-2% by weight of at least one polymeric ester.

It is known to use polymers based on unsaturated dialkyl C ₄ -C ₈ -dicarboxylates having an average alkyl chain length of 12 to 14 as cold flow improvers for certain crude distillate fuel oils (Patent Document 5). Unsaturated esters, especially vinyl acetate, are mentioned as suitable comonomers, but a-olefins are also mentioned as suitable comonomers.

following:
I) n-alkyl esters of monoethylenically unsaturated C ₄ -C ₈ mono- or dicarboxylic acids, wherein the average number of carbon atoms in the n-alkyl radical is 12 to 14 at least 25% by weight And a copolymer having another unsaturated ester or olefin;
II) Additive concentrates containing a combination with another low temperature fluidity improver for distillate fuel oil are known (Patent Document 6).

  Oils of vegetable or animal origin and blends of them with crude distillate fuel oils containing at least 17 mol% vinyl esters and improving the low temperature properties of them and containing at least 5 alkyl branches per 100 methylene groups One containing an ethylene-vinyl ester copolymer having a degree of branching is known (Patent Document 7).

Known additives include CFPP -10 ° C required for use as winter diesel in Southern Central Europe with fatty acid esters, especially those containing a total of more than 7% by weight of palmitic acid methyl ester and stearic acid methyl ester It is often impossible to reliably adjust to CFPP -20 ° C, which is required for use as winter diesel in Northern Central Europe, and CFPP -22 ° C or less for special applications. A further problem with existing additives is the lack of low temperature transition stability of the oil with the additive added, ie. When the oil is stored for a long time at various temperatures in the range below its cloud point. In addition, the set CFPP value of the oil gradually increases. In addition, oils with a high content of palmitic acid methyl ester and stearic acid methyl ester in particular show a strong tendency to settle in the course of being stored at low temperatures. Despite the achievement of CFPP, the precipitation of fatty acid esters with additives, which occurs under low temperature conditions in laboratory experiments, can lead to engine filter clogging, from which fuel is used for transportation It is known from practice that it is not suitable for
EP-A-0 665 873 EP-A-0 629 231 EP-A-0 543 356 DE-A-40 40 317 EP-A-0 153 176 EP-A-0 153 177 EP-A-1 491 614

  Thus, the object of the present invention is to improve the low temperature fluidity of fatty acid esters derived from, for example, rapeseed oil, used oil, sunflower oil and / or soybean oil and containing at least 7% by weight of palmitic acid methyl ester and stearic acid methyl ester. Thus, it is in providing an additive to set a CFPP value of -10 ° C or below -20 ° C which remains constant in the range below its cloud point even during the long storage of the oil. In addition, these additives show the settling tendency of these oils, they remain homogeneous and free-flowing and their CFPP does not change even after storing the fatty acid esters for several days. As such, it should contribute to prevention.

  It has now surprisingly been found that additives comprising ethylene copolymers and comb polymers are excellent flow improvers for such fatty acid esters.

The present invention includes the following:
A) ethylene, C ₁ -C ₁₈ - copolymers have an alkyl radical and the degree of branching is at least one 18 to 35 mol% of 5 CH _3/100 less acrylic acid than a CH ₂ group ester or vinyl ester, and
B) Comb polymer containing structural units formed from:
B1) at least one olefin as monomer 1 having at least one C ₈ -C ₁₈ -alkyl radical on the olefinic double bond, and
B2) containing at least one ethylenically unsaturated dicarboxylic acid as monomer 2 having at least one C ₈ -C ₁₆ -alkyl radical bonded via an amide and / or imide group,
Where parameter Q

(In the formula
w ₁ is the mole fraction of the individual chain length n _{1 in} the alkyl radical of monomer 1,
w ₂ is the molar ratio of the individual chain length n _{2 in} the alkyl radical of the amide and / or imide group of monomer 2,
n ₁ is the individual chain length in the alkyl radical of monomer 1;
n ₂ is the individual chain length in the alkyl radical of the amide and / or imide group of monomer 2,
i is a continuous variable for the chain length in the alkyl radical of monomer 1,
as well as
j is a continuous variable for the individual chain length in the alkyl radical of the amide and / or imide group of monomer 2)
Provides additives that assume values 23-27.

  The present invention further provides a fuel oil composition comprising a fuel oil of animal or vegetable origin and an additive as defined above.

  The invention further provides the use of an additive as defined above for improving the cold flow properties of a fuel oil of animal or plant origin.

  The present invention further provides a method for improving the cold flow properties of a fuel oil of animal or plant origin by adding the above defined additives to the fuel oil of animal or plant origin.

  In the preferred embodiment of the invention, Q assumes a value of 24-26.

  Olefin chain length is understood herein to mean the chain length of the monomeric olefin-2 olefinically bonded carbon atoms. For olefins having a non-terminal double bond, such as an olefin having a vinylidene moiety, the chain length is equal to the total chain length of the olefin-2 olefinically bonded carbon atoms.

  When considering polymers formed from olefins B1) and dicarboxamide / imide B2) rather than monomeric olefins, the chain length is the length of the alkyl radical introduced into the polymer by the olefin and off the polymer backbone. That's it.

Suitable ethylene copolymers A) preferably contain one or more vinyl esters and / or (meth) acrylic acid esters of 18 to 35 mol% and ethylene of 65 to 82% by weight. Particular preference is given to ethylene copolymers having 18.5 to 27 mol% of at least one vinyl ester. Suitable vinyl esters are derived from fatty acids having linear or branched alkyl groups having 1 to 30 carbon atoms. Suitable ethylene copolymers have a melt viscosity V _{140 of} at least 5 mPas, preferably 10-100 mPas, in particular 20-60 mPas.

  Examples of suitable vinyl esters are based on vinyl acetate, vinyl propionate, vinyl butyrate, vinyl hexanoate, vinyl heptanoate, vinyl octanoate, vinyl laurate and vinyl stearate, and branched fatty acids Esters of vinyl alcohol, such as vinyl isobutyrate, vinyl pivalate, vinyl 2-ethylhexanoate, vinyl isononanoate, vinyl neononanoate, vinyl neodecanoate and vinyl neoundecanoate. Also suitable as comonomers are esters of acrylic and methacrylic acids having 1 to 20 carbon atoms in the alkyl radical, such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n -And isobutyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, tetradecyl (meth) acrylate, hexadecyl (meth) Acrylate, octadecyl (meth) acrylate. Also suitable are mixtures of two, three, four or even more of these comonomers.

  Further suitable copolymers are olefins having 3 to 10 carbon atoms in addition to 18 to 35 mol% of ethylene and vinyl esters, such as propene, butene, isobutylene, hexene, 4-methylpentene, octene, diisobutylene. And / or norbornene from 0.5 to 10 mol%.

Copolymer A preferably has a weight-average molecular weight Mw of 1000 to 10000 g / mol, in particular 1500 to 5000 g / mol, as determined by gel permeation chromatography (GPC) against polystyrene standards in THF. ¹ thereof degree of branching determined by 1 H NMR spectroscopy (400 MHz using CDCl ₃ as a solvent) is less than 5 CH _3/100 CH ₂ groups, preferably less than 4 CH _3/100 CH ₂ groups. Methyl groups arise from short and long chain branches and not from copolymerized comonomers.

  Copolymer A can be prepared by conventional copolymerization processes such as suspension polymerization, solution polymerization, gas phase polymerization or high pressure bulk polymerization. Preference is given to carrying out the high-pressure bulk polymerization at a pressure of 50 to 400 MPa, preferably 100 to 300 MPa, and a temperature of 100 to 300 ° C., preferably 150 to 250 ° C. A particularly preferred production variant minimizes the temperature difference between the peroxide feeds along the tubular reactor in a multi-zone reactor, ie <50 ° C, preferably <30 ° C, especially <15 ° C. The polymerization is carried out while maintaining The maximum temperature difference between the individual reaction zones is preferably less than 30 ° C, more preferably less than 20 ° C, in particular less than 10 ° C.

  The monomer reaction is initiated by a free radical forming initiator (free radical chain initiator). This class of substances is, for example, oxygen, hydroperoxides, peroxides and azo compounds, such as cumene hydroperoxide, t-butyl hydroperoxide, dilauroyl peroxide, dibenzoyl peroxide, bis (2-ethylhexyl) peroxocarbonate, t-butyl Perpivalate, t-butylpermaleate, t-butylperbenzoate, dicumyl peroxide, t-butylcumyl peroxide, di (t-butyl) peroxide, 2,2'-azobis (2-methyl-propano) Nitrile), 2,2'-azobis (2-methylbutyronitrile). The initiator is used individually or as a mixture of two or more substances in an amount of 0.01 to 20% by weight, preferably 0.05 to 10% by weight, based on the monomer mixture.

  High pressure bulk polymerization is carried out in known high pressure reactors, such as autoclaves or tubular reactors, either batchwise or continuously; tubular reactors have been found to be particularly useful. Solvents such as aliphatic and / or aromatic hydrocarbons or hydrocarbon mixtures, benzene or toluene may be present in the reaction mixture. Preferred is a procedure that is substantially free of solvent. In a preferred embodiment of the polymerization, a mixture of monomers, initiator and, if used, regulator is fed to the tubular reactor via the reactor inlet and also via one or more side branches. Suitable regulators are, for example, hydrogen, saturated and unsaturated hydrocarbons, such as propane or propene, aldehydes, such as propionaldehyde, n-butyraldehyde or isobutyraldehyde, ketones such as acetone, methyl ethyl ketone, methyl isobutyl. Ketones, cyclohexanone, and alcohols such as butanol. The comonomer and also the regulator can be metered into the reactor either with ethylene or separately via a side stream. The monomer streams may have different compositions (EP-A-0 271 738 and EP-A-0 922 716).

Examples of suitable copolymers or terpolymers include:
Ethylene-vinyl acetate copolymer having 10-40% by weight vinyl acetate and 60-90% by weight ethylene;
An ethylene-vinyl acetate-hexcenter polymer known from DE-A-34 43 475;
Ethylene-vinyl acetate-diisobutylene terpolymer described in EP-A-0 203 554;
A mixture of ethylene-vinyl acetate-diisobutylene terpolymer and ethylene / vinyl acetate copolymer known from EP-A-0 254 284;
EP-A-0 405 270, a mixture of ethylene-vinyl acetate copolymer and ethylene-vinyl acetate-N-vinylpyrrolidone terpolymer;
Ethylene / vinyl acetate / isobutyl vinyl ether terpolymer as described in EP-A-0 463 518;
EP-A-0 493 769, ethylene / vinyl acetate / vinyl neononano containing 10-35% by weight of vinyl acetate and 1-25% by weight of certain neocompounds, apart from ethylene Art or vinyl neodecanoate terpolymer;
EP-A-0 778 875 ethylene, a first vinyl ester having up to 4 carbon atoms, a branched carboxylic acid having up to 7 carbon atoms or a branched chain having from 8 to 15 carbon atoms A terpolymer with a second vinyl ester derived from a non-tertiary carboxylic acid;
A terpolymer of ethylene described in DE-A-196 20 118 with one or more aliphatic C _2-to C ₂₀ -monocarboxylic acid vinyl esters and 4-methylpentene-1;
Terpolymers of ethylene, one or more aliphatic C _2-to C ₂₀ -monocarboxylic acid vinyl esters, and bicyclo [2.2.1] hept-2-ene, as disclosed in DE-A-196 20 119 ;
A terpolymer of ethylene described in EP-A-0 926 168 and at least one olefinically unsaturated comonomer containing one or more hydroxyl groups.

  Preference is given to using mixtures of identical or different ethylene copolymers. More preferably, the polymer on which the mixture is based differs in at least one property. For example, they may contain different comonomer, different comonomer content, molecular weight and / or degree of branching. The mixing ratio of the different ethylene copolymers is preferably 20: 1 to 1:20, preferably 10: 1 to 1:10, in particular 5: 1 to 1: 5.

  Copolymer B is derived from amides and imides of ethylenically unsaturated dicarboxylic acids. Suitable dicarboxylic acids are maleic acid, fumaric acid and itaconic acid, in particular maleic anhydride. A particularly suitable comonomer is monoolefin B1 having 10 to 20 carbon atoms, in particular 12 to 18 carbon atoms. These are preferably linear and preferably have a double bond terminal, such as dodecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene and octadecene. The molar ratio of dicarboxamide / imide to olefin in the polymer is preferably in the range from 1: 1.5 to 1.5: 1, in particular equimolar.

Copolymer B is also an ethylenically unsaturated dicarboxamide / imide and the above-mentioned olefins, such as olefins having 2 to 50 carbon atoms, allyl polyglycol ethers, C ₁ -C ₃₀ -alkyl (meth) acrylates, vinyl aromatics. Alternatively, it is possible to contain further comonomer copolymerizable with C ₁ -C ₂₀ -alkyl vinyl ethers in a minor amount of up to 20 mol%, preferably <10 mol%, in particular <5 mol%. Equivalently, small amounts of poly (isobutylene) having a molecular weight up to 5000 g / mol are used, preferred are highly reactive variants having a high proportion of terminal vinylidene groups. These additional comonomers are not taken into account in the calculation of the parameter Q, which is important for effectiveness.

  Allyl polyglycol ethers correspond to the general formula:

Where
R ¹ is hydrogen or methyl;
R ² is hydrogen or C ₁ -C ₄ -alkyl,
m is the number 1 to 100,
R ³ is C ₁ -C ₂₄ -alkyl, C ₅ -C ₂₀ -cycloalkyl, C ₆ -C ₁₈ -aryl or -C (O) -R ⁴ ;
R ⁴ is C ₁ -C ₄₀ -alkyl, C ₅ -C ₁₀ -cycloalkyl or C ₆ -C ₁₈ -aryl.

  The copolymers B) according to the invention are preferably prepared at a temperature of 50 to 220 ° C., in particular 100 to 190 ° C. The preferred manufacturing process is bulk polymerization without solvent, but also aprotic solvents such as benzene, toluene, xylene or higher boiling aromatic, aliphatic or isoaliphatic solvents or kerosene or Solvent Naphtha. It is also possible to carry out the polymerization in the presence of a solvent mixture such as Particularly preferred is polymerization in a small amount of mild, aliphatic or isoaliphatic solvent. The proportion of solvent in the polymerization mixture is usually between 10 and 90% by weight, preferably between 35 and 60% by weight. In solution polymerization, the reaction temperature may be adjusted particularly simply by the boiling point of the solvent or by operating at low or high pressure.

  The average molecular mass Mw of the copolymer B according to the invention is usually from 1200 to 200 000 g / mol as measured by gel permeation chromatography (GPC) against polystyrene standards in THF, in particular from 2000 to 100 000 g / mol. The copolymers B of the invention must be oil-soluble at the doses relevant to practice, ie they must dissolve without residue at 50 ° C. in the oil to which the additive is to be added.

  The monomer reaction is initiated by a free radical forming initiator (free radical chain initiator). The classes of substances are, for example, oxygen, hydroperoxides and peroxides, such as cumene hydroperoxide, t-butyl hydroperoxide, dilauroyl peroxide, dibenzoyl peroxide, bis (2-ethylhexyl) peroxodicarbonate, t-butyl peroxide. Pivalate, t-butyl permaleate, t-butyl perbenzoate, dicumyl peroxide, t-butyl cumyl peroxide, di (t-butyl) peroxide, and also azo compounds, such as 2-2'-azobis (2 -Methylpropanonitrile) or 2,2'-azobis (2-methylbutyronitrile). The initiators are used individually or as a mixture of two or more substances in an amount of 0.01 to 20% by weight, preferably 0.05 to 10% by weight, based on the monomer mixture.

  Copolymer B is prepared by reacting maleic acid, fumaric acid and / or itaconic acid or their anhydrides with the corresponding amine and then copolymerizing, or olefins with at least one unsaturated dicarboxylic acid or their derivatives, for example Can be prepared by either copolymerizing with itaconic anhydride and / or maleic anhydride and then reacting with an amine. Preference is given to carrying out the copolymerization with the anhydride and producing it, after which the resulting copolymer is converted into amides and / or imides.

  In both cases, the reaction with the amine is carried out, for example, by reacting at 50 to 300 ° C. with 0.8 to 2.5 mol of amine per mol of anhydride, preferably 1.0 to 2.0 mol of amine per mol of anhydride. When approximately 1 mole of amine is used per mole of anhydride, the monoamide is preferentially formed at a reaction temperature of approximately 50-100 ° C. and in addition has one carboxyl group per amide group. At higher reaction temperatures of approximately 100-250 ° C, water is removed from the primary amine and imides are preferentially formed. When higher amounts of amine are used, preferably 2 moles of amine per mole of anhydride, an amide-ammonium salt is formed at approximately 50-200 ° C and higher reaction temperatures such as 100-300 ° C, preferably 120-250 ° C., diamide is formed. The water of reaction may be distilled off by an inert gas stream or removed by azeotropic distillation in the presence of an organic solvent. In order to achieve this purpose, at least one organic solvent is preferably used by weight, preferably 20-80%, in particular 30-70%, in particular 35-55%. In the present specification, a copolymer having an acid value of 30-70 mg KOH / g, preferably 40-60 mg KOH / g (diluted to 50% in a solvent) is regarded as a monoamide. Corresponding copolymers with an acid number of less than 40 mg, in particular less than 30 mg KOH / g, are considered diamides or imides. Particularly preferred are monoamides and diamides.

Suitable amines are primary and secondary amines having one or two C ₈ -C ₁₆ -alkyl radicals. They may have one, two or three amino groups which are bonded via an alkylene radical having 2 or 3 carbon atoms. Preference is given to monoamines. In particular, they have linear alkyl radicals, but also contain small amounts of branched amines (1-position or 2-position), for example up to 30% by weight, preferably up to 20% by weight, in particular up to 10% by weight. May be. Either shorter or longer chain amines may be used, but their proportion is preferably less than 20 mol%, in particular less than 10 mol%, based on the total amount of amine used. For example, 1 to 5 mol%.

  Particularly preferred primary amines are octylamine, 2-ethylhexylamine, decylamine, undecylamine, dodecylamine, n-tridecylamine, isotridecylamine, tetradecylamine, pentadecylamine, hexadecylamine and their It is a mixture.

Suitable secondary amines are dioctylamine, dinonylamine, didecylamine, didodecylamine, ditetradecylamine, dihexadecylamine, and also amines with different alkyl chain lengths, such as N-octyl-N-decylamine, N- Decyl-N-dodecylamine, N-decyl-N-tetradecylamine, N-decyl-N-hexadecylamine, N-dodecyl-N-tetradecylamine, N-dodecyl-N-hexadecylamine, N-tetradecyl -N-hexadecylamine. In addition to C ₈ -C ₁₆ -alkyl radicals, secondary amines having shorter side chains with 1 to 5 carbon atoms, for example methyl or ethyl groups, are also suitable according to the invention. In the case of secondary amines, it is the average of the alkyl chain lengths C _{8 to} C ₁₆ that is taken into account as the alkyl chain length n to calculate the parameter Q. If either shorter or longer alkyl radicals are present, they do not contribute to the effectiveness of the additive and are not taken into account in the calculation.

  A particularly suitable copolymer B contains monoamide and diamide of primary monoamine as monomer 2.

  The use of a mixture of different olefins in the polymerization and a mixture of different amines in the amidation or imidization allows the effectiveness to be further adapted to the specific fatty acid ester composition.

In a preferred embodiment, the additives and components A and B may also comprise polymers and copolymers based on C ₁₀ -C ₂₄ -alkyl acrylates or methacrylates (component C). These poly (alkyl acrylates) and methacrylates have a molecular weight Mw 800-1 000 000 g / mol, and capryl alcohol, caprin alcohol, undecyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, palmitoleyl alcohol Stearyl alcohol or a mixture thereof, for example, coconut alcohol, palm alcohol, tallow fatty alcohol or behenyl alcohol.

  In a preferred embodiment, a mixture of different copolymers B is used in which the average (weight average) of the parameters Q of the mixture components assumes a value of 23-27, preferably a value of 24-26.

  The mixing ratio of the additive components A and B according to the invention is (from parts by weight) 20: 1 to 1:20, preferably 10: 1 to 1:10, in particular 5: 1 to 1: 5. is there. The proportion of component C in the formulation composed of A, B and C may be up to 40% by weight, based on the total weight of A, B and C; it is preferably less than 20% by weight, in particular 1 to 10% by weight.

  The additives according to the invention are added to the oil in an amount of 0.001 to 5% by weight, preferably 0.005 to 1% by weight, in particular 0.01 to 0.6% by weight. They can be used as such or in solvents such as aliphatic and / or aromatic hydrocarbons or hydrocarbon mixtures such as toluene, xylene, ethylbenzene, decane, pentadecane, petroleum fractions, kerosene, naphtha, diesel, Heating oil, isoparaffin or commercial solvent mixture such as Solvent Naphtha, Hydrosol® A 200 N, Shellsol® A 150 ND, Caromax® 20 LN, Shellsol AB, Solvesso® 150 , Solvesso 150 ND, Solvesso 200, Exsol®, Isopar® and Shellsol D types may be dissolved or dispersed. They are preferably dissolved in fuel oils of animal or vegetable origin based on fatty acid alkyl esters. The additive according to the invention preferably contains 1-80%, in particular 10-70%, in particular 25-60% of a solvent.

  In a preferred embodiment, the fuel oil, often referred to as biodiesel or biofuel, comprises fatty acid alkyl esters composed of fatty acids having 12 to 24 carbon atoms and alcohols having 1 to 4 carbon atoms. Typically, a relatively large portion of the fatty acid contains one, two or three double bonds.

  Examples of oils derived from animal or plant materials and in which the additives of the present invention can be used are rapeseed oil, coriander oil, soybean oil, cottonseed oil, sunflower oil, castor oil, olive oil, peanut oil, corn oil, Almond oil, palm kernel oil, coconut oil, mustard seed oil, beef tallow, bone oil, fish oil and used cooking oil. Further examples include oils derived from wheat, jute, sesame, shea butternut, peanut oil and linseed oil. Fatty acid alkyl esters, also referred to as biodiesel, can be derived from these oils by processes disclosed by the prior art. Preference is given to rapeseed oil, which is a mixture of fatty acids partially esterified with glycerol, since rapeseed oil can be obtained in large quantities by extracting and pressing rapeseed and in a simple manner. In addition, preferred are used oils such as spent oil, palm oil, sunflower and soy, as well as mixtures of them with rapeseed oil.

  Particularly suitable biofuels are lower alkyl esters of fatty acids. These include, for example, fatty acids having 14 to 22 carbon atoms, such as lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, elaidic acid, petroceric acid, ricinoleic acid, elaeostearic Acid, linoleic acid, linolenic acid, eicosanoic acid, gadoleic acid, docosanoic acid or ethyl ester, propyl, butyl and especially methyl esters of erucic acid, each of which preferably has an iodine value of 50-150, in particular 90- Including commercially available mixtures of those having 125. Mixtures having particularly advantageous properties are those which mainly comprise at least 50% by weight of methyl esters of fatty acids having 16 to 22 carbon atoms and 1, 2 or 3 double bonds. Preferred lower alkyl esters of fatty acids are the methyl esters of oleic acid, linoleic acid, linolenic acid and erucic acid.

  Commercial mixtures of the type described above are obtained, for example, by hydrolyzing and esterifying animal and vegetable fats and oils with lower aliphatic alcohols or by transesterification. Spent cooking oil is equally suitable as a starting material. For the production of lower alkyl esters of fatty acids, it is advantageous to start with fats and oils having a high iodine value, such as sunflower oil, rapeseed oil, coriander oil, castor oil, soybean oil, cottonseed oil, peanut oil or beef tallow It is. Preferred are lower alkyl esters of fatty acids based on a new type of rapeseed oil, wherein more than 80% by weight of their fatty acid components are derived from unsaturated fatty acids having 18 carbon atoms.

  Biofuels are therefore oils that can be obtained from plant material or animal material or both or derivatives thereof and used as fuel, in particular as diesel or heating oil. Although many of the above oils can be used as biofuels, preferred are primarily vegetable oil derivatives, particularly suitable biofuels are rapeseed oil, cottonseed oil, soybean oil, sunflower oil, olive oil or palm Alkyl ester derivatives of oil, very particularly preferred are rapeseed oil methyl ester, sunflower oil methyl ester, palm oil methyl ester and soybean oil methyl ester. Due to the high demand for biofuels, an increasing number of manufacturers are switching from fatty acid methyl esters to other more useful sources. As used herein, in particular of biodiesel alone or other fatty acid methyl esters such as rapeseed oil methyl ester, sunflower oil methyl ester, palm oil methyl ester and soybean oil methyl ester in blends with spent oil methyl ester. The used oil used in the form should be mentioned. It should also include a mixture of rapeseed oil methyl ester and soybean oil methyl ester or a mixture of rapeseed oil methyl ester and a mixture of soybean oil methyl ester and palm oil methyl ester or a mixture of soybean oil methyl ester and palm oil methyl ester. .

  The additive can be introduced into the oil to which the additive is to be added by processes known in the prior art. If more than one additive component or co-additive component is to be used, such components can be introduced into the oil together in any combination together or separately.

  The additive of the invention has a biodiesel CFPP value lower than -10 ° C and -20 ° C, in some cases -25 ° C, depending on marketing requirements, especially for use in winter. Allows adjustment to a lower value. Similarly, by adding the inventive additives, the pour point of biodiesel is lowered. The additive of the invention has a high proportion of more than 7% by weight of esters of saturated fatty acids, palmitic acid and stearic acid, as present, for example, in fatty acid methyl esters obtained from used oil, sunflower and soy This is particularly advantageous in certain oils. Thus, depending on the additive of the invention, a mixture of rapeseed oil methyl ester and / or used oil methyl ester and / or sunflower oil methyl ester and / or soybean oil methyl ester may have a CFPP value of -10 ° C or -20 ° C. The following adjustment is also possible. From this, it is also possible to adjust the used oil methyl ester or sunflower oil methyl ester or soybean oil methyl ester to a CFPP value of −10 ° C. or −20 ° C. or less by the additive of the invention. In addition, oils added with additives in this way have good low temperature transition stability, i.e. CFPP values remain constant even when stored under winter conditions, and constant low temperatures ( For example, it does not tend to precipitate at -10 ° C or -22 ° C).

  One or more of the oil-soluble co-additives that improve the low temperature flow properties of crude oil, lubricating oil or fuel oil, even alone, to produce an additive package to specifically solve the problem May be used together. Examples of such co-additives are polar compounds that provide paraffin dispersancy (paraffin dispersant) and oil-soluble amphiphile.

  The inventive additive may be used in a mixture with a paraffin dispersant. Paraffin dispersants have the effect of reducing the size of the paraffin crystals and leaving the paraffin particles dispersed in a colloidal form with significantly reduced tendency to settle rather than settle. Useful paraffin dispersants have been found to be both low and high molecular weight oil soluble compounds having ionic or polar groups, such as amine salts and / or amides. Particularly preferred paraffin dispersants are the reaction products of secondary fatty amines having 20 to 44 carbon atoms, in particular coconut amine, ditallow fatty amine, distearylamine and dibehenylamine with carboxylic acids and their derivatives. including. Particularly useful paraffin dispersants are by reacting aliphatic or aromatic amines, preferably long chain aliphatic amines, with aliphatic or aromatic mono-, di-, tri- or tetracarboxylic acids or their anhydrides. It was found to be obtained (see US Pat. No. 4,211,534). Equally suitable as paraffin dispersants are the amides and ammonium salts of aminoalkylene polycarboxylic acids such as nitrilotriacetic acid or ethylenediaminetetraacetic acid and secondary amines (see EP 0 398 101). Other paraffin dispersants are copolymers of maleic anhydride and a, b-unsaturated compounds, which may optionally be reacted with primary monoalkylamines and / or aliphatic alcohols (EP 0 154 177), reaction products of alkenyl-spiro-bislactones with amines (see EP 0 413 279 B1), and according to EP-A-0 606 055 A2, a, b-unsaturated dicarboxylic anhydrides The reaction product of terpolymers based on polyoxyalkylene ethers of a, b, unsaturated compounds and lower unsaturated alcohols.

  The mixing ratio of the inventive additive to the paraffin dispersant (expressed in parts by weight) is from 1:10 to 20: 1, preferably from 1: 1 to 10: 1.

  Oils treated with the inventive additives may also be added to middle distillates obtained from crude oil. Instead of the biofuel and middle distillate mixture thus obtained, low temperature additives such as flow improvers or wax dispersants, and also performance packages can be incorporated.

  The mixing ratio of biofuel and middle distillate can be from 1:99 to 99: 1. Particularly preferred is a mixing ratio of biofuel: middle distillate = 3: 97 to 30:70.

  Middle distillate refers specifically to those mineral oils obtained by distilling crude oil and having a boiling point in the range of 120-450 ° C, such as kerosene, jet fuel, diesel and heating oil. Preference is given to using those middle distillates whose sulfur content is less than 0.05% by weight, more preferably less than 350 ppm, in particular less than 200 ppm and in special cases less than 50 ppm. They are usually refined under hydrogenation conditions and are therefore their middle distillates containing only a small proportion of polyaromatic and polar compounds. They are preferably those middle distillates whose 95% distillation point is below 370 ° C, especially below 350 ° C and in special cases below 330 ° C. Suitable middle distillates are also synthetic fuels, such as those made available by the Fischer-Tropsch process.

  Additives can be used alone or other additives such as other pour point depressants or dewaxers and antioxidants, cetane improvers, dehaze agents, demulsifiers, detergents, It may be used in combination with dispersants, defoamers, dyes, corrosion inhibitors, conductivity improvers, sludge inhibitors, odorants and / or additives to lower the cloud point.

  In the table below, the mixing ratio by weight of additives A, B and C is A: B = 4: 1, or if C is present in the mixture, A: B: C = 4: 1 : 0.2. The total amount of additive is evident from the top row of the table.

Claims (15)

following:
A) ethylene, C ₁ -C ₁₈ - copolymers have an alkyl radical and the degree of branching is at least one 18 to 35 mol% of 5 CH _3/100 less acrylic acid than a CH ₂ group ester or vinyl ester, and
B) Comb polymer containing structural units formed from:
B1) at least one olefin as monomer 1 having at least one C ₈ -C ₁₈ -alkyl radical on the olefinic double bond, and
B2) containing at least one ethylenically unsaturated dicarboxylic acid as monomer 2 having at least one C ₈ -C ₁₆ -alkyl radical bonded via an amide and / or imide group,
Where parameter Q

(In the formula
w ₁ is the mole fraction of the individual chain length n _{1 in} the alkyl radical of monomer 1,
w ₂ is the molar ratio of the individual chain length n _{2 in} the alkyl radical of the amide and / or imide group of monomer 2,
n ₁ is the individual chain length in the alkyl radical of monomer 1;
n ₂ is the individual chain length in the alkyl radical of the amide and / or imide group of monomer 2,
i is a continuous variable for the chain length in the alkyl radical of monomer 1,
as well as
j is a continuous variable for the individual chain length in the alkyl radical of the amide and / or imide group of monomer 2)
Is a fuel oil additive assuming a value of 23-27.   The fuel oil additive of claim 1, wherein Q assumes a value of 24-26.   The fuel oil additive according to claim 1 and / or 2, wherein component A) comprises 18.5 to 27 mol% of at least one vinyl ester.   The fuel oil additive according to one or more of claims 1 to 3, wherein component A) comprises 0.5 to 10 mol% of an olefin having 3 to 10 carbon atoms. Construction the degree of branching of component A) is ¹ determined by H NMR spectroscopy, fuel oil additive as claimed in one or more 4 CH _3/100 CH ₂ groups smaller claims 1-4.   The fuel oil additive according to one or more of claims 1 to 5, wherein the olefin forming component B1) is an α-olefin.   The fuel oil additive according to one or more of the preceding claims, wherein the molar ratio of comonomer B1) to comonomer B2) in copolymer B) is 1.5: 1 to 1: 1.5. Copolymer B and comonomers B1) and B2) are also different from B1) and B2) in olefins having 2 to 50 carbon atoms, allyl polyglycol ethers, C ₁ -C ₃₀ -alkyl (meth) acrylates, vinyl aromas A fuel oil additive according to one or more of the preceding claims, which also contains up to 20 mol% of a further comonomer selected from the group or C ₁ -C ₂₀ -alkyl vinyl ethers, and polyisobutenes having a molecular weight of up to 5000 g / mol . 9. The fuel oil additive according to one or more of claims 1 to 8, wherein component A) has a melt viscosity V ₁₄₀ 5 to 100 mPas.   10. The fuel oil additive according to one or more of claims 1 to 9, wherein component A) has a molecular weight of 1000 to 10 000 g / mol.   11. The fuel oil additive according to one or more of claims 1 to 10, wherein component B) has a molecular weight of 1200 to 200 000 g / mol.   A fuel oil composition comprising a fuel oil of plant or animal origin and a fuel oil additive according to one or more of claims 1-11. The fuel oil composition of claim 12, wherein the fuel oil comprises a mixture of fatty acid esters of C ₁ -to C ₄ -alcohol.   14. The fuel oil composition according to claim 13, wherein the fatty acid ester comprises stearic acid methyl ester and palmitic acid methyl ester in a proportion of at least 7% by weight.   Use of a fuel oil additive according to one or more of claims 1 to 11 for improving the low temperature behavior of fuel oils of plant or animal origin.