DE10250003A1 - Flow improver for fuels - Google Patents

Abstract

By adding reaction products of amines of the general formula (I) NR · 1 · R · 2 · R · 3 · in which R · 1 ·, R · 2 ·, R · 3 · independently of one another for a hydrogen atom, an alkyl radical with 1 to 22 C atoms or a hydroxylalkyl radical having 1 to 22 C atoms and at least one hydroxyl group or an aminoalkyl radical having 1 to 22 C atoms, with fatty acids of the general formula (II) R · 4 · -COOH in the R · 4 · Represents a branched or unbranched alkyl or alkenyl radical having 7 to 25 carbon atoms, in a molar ratio (I): (II) of 1: 1 to 1: 3 and at temperatures of 80 to 140 ° C., the cold flow behavior of fuels, especially diesel fuels, are improved.

Description

The present invention relates to the use of esterified hydroxylalkylamines or fatty acid amides and their derivatives, as additives to improve the flow properties of fuels, especially diesel fuels.

In hydrocarbon-based fuels, e.g. e.g. Gas oils, heating oils, Petrol, kerosene etc., numerous additives are used. So are alongside additives for corrosion protection and lubricity also flow improvers available. Especially in diesel, which produces in the colder seasons and is consumed, such additives are necessary for smooth functioning to ensure the motors.

Among fuels are under based on this registration of hydrocarbons, the free combustion energy of which is mechanical Work is understood. This includes all types of at room temperature and normal pressure liquid Motor and aviation fuels. Motor fuels, e.g. for car or Truck engines usually contain hydrocarbons, e.g. Gasoline or heavies Petroleum fractions or diesel fuel.

Diesel fuels in particular are flame-retardant mixtures of liquid hydrocarbons, which are used as fuels for constant pressure or burner motors (diesel engines) and mainly consist of paraffins with admixtures of olefins, naphthenes and aromatic hydrocarbons. Their composition is inconsistent and depends particularly on the manufacturing method. Diesel is obtained, for example, from gas oil by cracking or from tars obtained from the smoldering of lignite or hard coal. Typical products have a density between 0.83 and 0.88 g / cm ³ , a boiling point between 170 and 360 ° C and flash points between 70 and 100 ° C. Diesel oils for stationary systems and for marine engines have a similar composition to heavy heating oil, those for cars, buses and trucks correspond to the heating oil EL. When burning in a diesel engine, air is sucked into the cylinder, heated to 550-900 ° C by strong compression (compression ratio 14: 1 to 25: 1), whereby a jet of injected diesel ignites automatically and at a combustion temperature of 1500- 2200 ° C reaches a combustion pressure of 50-80 bar, through which the piston is moved and work is done. 13 m ^{3 of} air are used to burn 1 liter of diesel in a diesel engine; the combustion energy released is approximately 42,000 kJ / kg. An essential factor for the usability of diesel is its ignitability, for whose quantitative indication the cetane number (CZ) was introduced. Ignitability is the property of an engine fuel to ignite more easily or more difficultly in an engine operating on the diesel principle. In addition to atomization, pressure and temperature, a preparation period (ignition delay) is required for each fuel until the combustion can be determined. Good ignitability of a fuel means favorable starting behavior and smooth running of the diesel engine due to a short preparation time or a small ignition delay; in the event of a large ignition delay, the well-known "nailing" is evident. The requirements for diesel are CZ 20-40 for slow-running engines, CZ> 45 for small and high-speed engines. A low pour point, low content of non-combustible and sooty substances and are also desirable a low sulfur content.

Fuels in general and especially In addition to the volatile components, diesel also contains Paraffins in solution Shape. These paraffins have a relatively high molecular weight across from the hydrocarbons so they're at lower temperatures tend to fail. The fuels can run at these temperatures be flowable yourself. However, the failed paraffins block lines, filters and injectors, whereby the supply of the internal combustion engine is no longer guaranteed becomes. To solve this problem become so-called flow improvers used. The different diesel types differ in that that different fraction cuts in the refineries according to the desired fuel profile be mixed. By using higher boiling fractions you get one Diesel with poorer cold behavior. This is compensated for by the addition of higher boiling fractions. The aim in formulating such fuel mixtures is to use them all sorts Hydrocarbon fractions to make a fuel with as much as possible favorable temperature behavior to obtain. However, the aim is to have the smallest possible proportion of low-boiling fractions, as these are expensive as aviation fuel and kerosene can be distributed. The more higher boiling fractions can be used for production, the cheaper is it for the refinery, as it is otherwise relatively inexpensive as marine diesel must be submitted. In order to still have a good flow behavior additives and co-additives can be obtained at low temperatures used. The fuel types mentioned are seasonal, as in Better cold behavior in winter needed will, especially in diesel fuels. The commonly used and recognized test method for the determination of the cold behavior of fuels is the so-called CFPP test (Cold Filter Plugging Point). The method is described in DIN EN 116. Measured is the temperature at which a certain volume of fuel no longer sucked through a filter under a defined vacuum can be. The measuring unit is gradually increased by one temperature decreased. The temperature reached is the CFPP value.

A basic distinction is made between three types of diesel, which differ based on their composition and characterize their distillation behavior. In practice, all types have in common that they have basic additives by means of a polymer, in general an ethylene vinyl carboxylate, preferably ethylene vinyl acetate (EVA) or polyolefin, in particular poly-alpha-olefins, to improve the flow behavior. The mode of action is that a large number of crystallization nuclei are generated by the additives. This leads to irregular crystal growth, which only produces small crystals. As a result, the fuel remains filterable for longer. These additives usually only work in certain fuel compositions. A mode of action that is as far-reaching as possible and covers many different types of fuel is rarely available. Such products are used, for example, in the EP-A-0 326 356 described, this document also describes the use of crosslinked, nitrogen-containing esters. In the so-called narrow-range and broad-range diesels in particular, additional Cu additives are used if the efficiency of the EVA's, the polyolefins or alternative additives is not sufficient. The use of various copolymers, such as n-alkyl fumerates / vinyl acetates, is described for narrow-range diesels. The molecular weight of these additives is between 1000 and 5000. High-molecular structures with molecular weights between 4000 and 10,000 are used in the so-called HFB diesels (high-final boiling point). The aim of the additives is to improve the flow properties of the fuels, particularly in the case of diesel fuels, even at low temperatures, ie at temperatures below 0 ° C., in particular below -10 ° C.

There is still a need for improved Additives for Diesel fuels to improve their flow properties at low temperatures to improve. Doing so does not adversely affect the other properties of the fuel become. Moreover are such additives desired, that can be obtained on the basis of renewable raw materials it was found that the particular nitrogenous ester described above Fulfill a task.

A first subject of the present invention therefore relates to the reaction products of amines of the general formula (I) NR ¹ R ² R ³ (I) in which R ¹ , R ² , R ³ independently of one another represent a hydrogen atom, an alkyl radical having 1 to 22 C atoms or a hydroxylalkyl radical having 1 to 22 C atoms and at least one hydroxyl group, or an aminoalkyl radical having 1 to 22 C atoms with the proviso that at least one of the radicals is a hydroxyalkyl radical with 1 to 22 C atoms or an aminoalkyl radical with 1 to 22 C atoms, with fatty acids of the general formula (II) R ⁴ -COOH (II) in which R ^{4 represents} a branched or unbranched, alkyl or alkenyl radical having 7 to 21 carbon atoms, in a molar ratio (I): (II) of 1: 1 to 1: 3 and at temperatures of 80 to 140 ° C. , as an additive to improve the flow properties of fuels at temperatures of 0 ° C or less.

These reaction products, as well as the raw materials from which they are manufactured, are known compounds. The amines of the formula (I) are generally commercially available. Such amines are preferably selected as raw materials for the products to be used according to the invention in which all the radicals R ¹ to R ^{3 are} either alkyl radicals or preferably hydroxylalkyl radicals. It is decisive that at least one radical is a hydroxylalkyl radical or an aminoalkyl radical, the amines preferably contain two of these radicals and in particular three hydroxylalkyl radicals in the molecule. However, the use of triethanolamine (in the formula (I) R ¹ = R ² = R ³ = CH ₂ CH ₂ -OH) or of di (2-aminoethyl) amine for the preparation of the reaction products is also particularly preferred. Other suitable amines are triisopropanolamine, diisopropanolamine, monosisopropanol, diethanolamine, monoethanolamine. "Mixed" types containing alkyl and hydroxyalkyl radicals can also be used advantageously. It can also be used aminoalkoxylierte alcohols aminoalkoxylierte alkoxylates or aminated alkoxylates such as aminopropylstearyl, Aminoproylethoxystearylamin, Fettalkylpolyethylenlgykolamin (such as aminated Lutensol ^® brands from BASF AG) and diethylenetriamine, polyamines, N, N-dimethylpropylene, N, N-Dimehtyldipropylentriamin or Fettalkylpolyethylenglykolamin.

The fatty acids of the formula (II) are also known per se and are commercially available. Suitable are both branched and unbranched, as well as saturated or mono- or polyunsaturated fatty acids. Typical examples are caproic acid, caprylic acid, 2-ethyl-hexanoic acid, capric acid, lauric acid, isotridecanoic acid, myristic acid, palmitic acid, palmoleic acid, stearic acid, isostearic acid, oleic acid, elaidic acid, petroselinic acid, linoleic acid, linolenic acid, elaeostearic acid, ginoleic acid and arachic acid, arachic acid, arachic acid Technical mixtures that occur, for example, in the pressure splitting of natural fats and oils, in the reduction of aldehydes from Roelen's oxosynthesis or in the dimerization of unsaturated fatty acids. technical fatty acids with 8 to 18 carbon atoms, as in for example coconut, palm, palm kernel, soy, rapeseed, sunflower, HOSO, safflower, peanut, castor, olive oil, grape seed, canola, bone fat, pork rind, tall oil or tallow fatty acid. It may also be advantageous to select any mixtures of the possible fatty acids for the synthesis of the reaction products according to the invention. It is particularly advantageous to select those fatty acids of the formula (II) in which R ^{4 is} a saturated alkyl radical having 5 to 25, preferably 11 to 17, carbon atoms.

The implementation of the alkylamines (I) with the fatty acids extends according to the invention as follows: First of all, preferably in a nitrogen atmosphere, the fatty acid (II) submitted, and at increased Temperature, which is between 80 and 140 ° C, preferably between 80 and 120 ° C, the amine (I) fed. That during the Water formed in the reaction can be removed by distillation. Then will the product obtained is obtained, for example, by filtration and can then be used according to the invention become. The acid (II) and the hydroxylalkylamine (I) are in molar ratios reacted from 1: 1 to 3: 1. Dependent on on the structure of the starting materials and the specific reaction conditions Mixtures of partially or fully esterified then arise Derivatives of hyroxylalkylamines (I).

It is preferred according to the invention not only to use the reaction products from compounds of the formulas (I) and (II) as described above, but rather to derivatize them again by reacting them with dicarboxylic acids of the formula (III) HOOC-R ⁵ -COOH (III) in which R ^{5 represents} a divalent, branched or unbranched, saturated or unsaturated alkyl radical having 2 to 21 carbon atoms, at temperatures of 100 to 200 ° C in a molar ratio of reaction products as described above to dicarboxylic acids of the formula (III) of 100 : 1 to 1: 1 continues to implement. Known saturated and unsaturated dicarboxylic acids, such as fumaric or maleic acid, but also malonic, succinic, glutaric, adipic, pimelin, cork, azealic, sebacic, brassyl, thapsic and phellogenic acid can be known be used. The anhydrides of dicarboxylic acids, especially maleic anhydride, are also suitable. A method of making these products as described above is also claimed.

It is also possible to use the Products implementing (I) and (II) with (III) in a third Step with ethylene oxide and / or propylene oxide to react and to use the derivatives thus obtained according to the invention. Preferably ethylene oxide is used in the implementation in this third step.

It is possible to mix both additives according to the invention to be used, e.g. products implementing (I) with (II) with such products that continue with dicarboxylic acids (III) were derivatized. Also regarding the implementation products themselves, it may be advantageous to use different derivatives, for example to use such products of the implementation of (I) with (II) that only hydroxylalkyl residues contain in admixture with products that only have aminoalkyl radicals. Even mixed derivatives, both Aminoalkyl radicals as well as hydroxylalkyl radicals are preferred.

The reaction products according to the above Descriptions can then the fuels as the sole or, preferably as co-additives to the common ones EVA's and polyolefins to improve their flow properties in effective amounts, i.e. between 10 and 1000 ppm, preferably between 50 and 500 ppm and in particular between 100 and 300 ppm be added. It is preferred that the weight ratio of Basic additives to the C additives according to the invention in the range from 10: 1 to 1: 1 lies.

By adding the additives according to the invention are preferably CFPP values of less than -10 ° C, in particular less than -20 ° C for fuels and achieved here especially with diesel fuels. Particularly preferred is the use of the reaction products to improve the flow of diesel fuels, especially those with similar ones Additives from the state of the art fuels. Usually Diesel fuels are preferably ethylene vinyl carboxylates Ethylene vinyl acetate (EVA's), Polyolefins, preferably poly-alpha-olefins and corresponding derivatives added, these additives in amounts between 10 and 1000 ppm can be included. The efficiency of these basic additives usually leads to a reduction of the CFPP up to a maximum of –20 ° C depending on Composition of the fuel. To further humiliation too achieve the additives described in the invention are necessary.

Another embodiment of the present Invention relates to a diesel fuel containing the reaction products according to the above Contains description in amounts between 10 and 1000 ppm. Such Diesel fuels according to the invention preferably have CFPP values according to DIN EN 116 of less than -20 ° C. Farther are preferred diesel fuels that have little or no Contain sulfur, with sulfur contents of less than 2 ppm preferred are. About that In addition, the new co-additives found unfold their full effectiveness in lower Temperature ranges if by a basic additive with commercial flow improvers the CFPP value is already in the range of –5 ° C to –20 ° C. This is necessary to for example in the German specifications for diesel fuels to achieve the specified CFPP value of –22 ° C.

The fuel compositions according to the invention contained diesel, gas oil, heating oils, Petrol, kerosene or other hydrocarbon mixtures liquid at room temperature, for example hexane or pentane. Those are particularly preferred Fuel compositions containing diesel as a fuel. in principle is it also possible Fuel compositions according to the present To provide invention, which also mixtures of different Hydrocarbons such as gasoline and kerosene in any conditions contain.

Depending on the intended use, the diesel fuels according to the invention other additives used: flow improvers, paraffin dispersants, Anti-foam agent, corrosion protection, antioxidants, emulsifiers, lubricity, Detergents, cetane number improvers, conductivity improvers and dyes.

Another embodiment of the invention relates a method for improving the cold flowability of fuels, in particular of diesel fuels by making the fuel conversion products according to the above Description added in amounts between 10 and 1000 ppm.

Examples

To demonstrate the effect of the additives according to the invention different diesel fuels were measured for their CFPP ( tested according to DIN EN 116). For this, the CFPP values were one with Ethylene vinyl acetate polymer or polyolefins basic additives Diesel compared and those diesel fuels that additionally an additive according to the invention (AV 48 to 55) included. The results (in ° C) are shown in Table 1.

The additives used according to the invention are characterized as follows:
A1 is a reaction product of lard fatty acid with triethanolamine in a molar ratio of 1.25: 1.
A2 is a reaction product of a mixture of 50% lard fatty acid and 50% vegetable stearic acid with triethanolamine in a molar ratio of 1.25: 1.
A3 is a reaction product of coconut fatty acid with triethanolamine in a molar ratio of 1.33: 1.
A4 is a reaction product of tall oil fatty acid with diethylenetriamine and maleic anhydride in a ratio of 6.8: 1.2: 1.
A5 is a reaction product of tall oil fatty acid with diethylenetriamine and maleic anhydride in a ratio of 6.5: 1.1: 1.
A6 is a reaction product of tall oil fatty acid with diethylenetriamine and maleic anhydride in a ratio of 6.8: 1.2: 1, which was then reacted with 60% ethylene oxide.
A7 is a reaction product of tall oil fatty acid with diethylenetriamine and maleic anhydride in a ratio of 6.7: 1.16: 1.

Table 1

The following table shows the Results of the reaction products of the fatty acids (II) with amines (I) and possibly dicarboxylic acids (III). Only one diesel type and different ones were used Concentrations of additive according to the invention tested. The diesel contained a commercial additive for basic additives.

Claims (15)

Use of the reaction products of amines of the general formula (I) NR ¹ R ² R ³ (I) in which R ¹ , R ² , R ³ independently of one another represent a hydrogen atom, an alkyl radical having 1 to 22 C atoms or a hydroxylalkyl radical having 1 to 22 C atoms and at least one hydroxyl group, or an aminoalkyl radical having 1 to 22 C atoms with the proviso that at least one of the radicals is a hydroxyalkyl radical with 1 to 22 C atoms or an aminoalkyl radical with 1 to 22 C atoms, with fatty acids of the general formula (II) R ⁴ -COOH (II) in which R ^{4 represents} a branched or unbranched, alkyl or alkenyl radical having 7 to 25 carbon atoms, in a molar ratio (I): (II) of 1: 1 to 1: 3 and at temperatures of 80 to 140 ° C. , as an additive to improve the flow properties of fuels at temperatures of 0 ° C or less. Use according to claim 1, characterized in that the additives used are those products which are obtained by reacting the reaction products according to claim 1 with dicarboxylic acids of the formula (III) HOOC-R ⁵ -COOH (III) in which R ^{5 represents} a divalent, branched or unbranched, saturated or unsaturated alkyl radical having 2 to 21 C atoms, at temperatures from 100 to 200 ° C in a molar ratio of reaction products according to claim 1 to dicarboxylic acids of the formula (III) of 100 : 1 to 1: 1. Use according to claims 1 to 2, characterized in that that a diesel fuel is selected as the fuel. Use according to claims 1 to 3, characterized in that that an additive diesel fuel is selected as the fuel. Use according to claims 1 to 4, characterized in that that as a fuel with polymeric ethylene vinyl carboxylate or Poly-alpha-olefin additive diesel is selected. Use according to claims 1 to 5, characterized in that reaction products of amines of the formula (I) in which R ¹ = R ² = R ³ = CH ₂ CH ₂ -OH are selected with fatty acids of the formula (II). Use according to claims 1 to 5, characterized in that reaction products of amines of the formula HN (CH ₂ -CH ₂ -NH ₂ ) ₂ with fatty acids of the formula (II) are selected. Use according to claims 1 to 7, characterized in that reaction products of amines of the formula (I) with fatty acids of the formula (II) in which R ^{4 is} a saturated alkyl radical having 5 to 21, preferably 11 to 17, carbon atoms, are selected. Use according to claims 1 to 8, characterized in that that the reaction products in amounts of 10 to 1000 ppm, preferably 50 to 500 ppm and in particular 100 to 2.50 ppm can be used. Diesel fuel containing reaction products as additives according to claim 1 in amounts of 10 to 1000 ppm. Diesel fuel according to claim 10, additionally containing polymer Ethylene vinyl carboxylates or poly-alpha-olefins in amounts of 10 up to 1000 ppm. Diesel fuel according to claims 10 to 11, characterized in that that the diesel fuel has a CFPP value according to DIN EN 116 of less than –20 ° C. Process for improving the cold flow properties of fuels, characterized in that the fuel conversion products according to claims 1 to 9 added in amounts of 10 to 1000 ppm. Process for the preparation of additives to improve the flow properties of fuels, characterized in that a) fatty acids of the general formula (II) R ⁴ -COOH (II) in which R ^{4 represents} a branched or unbranched, alkyl or alkenyl radical having 7 to 21 carbon atoms, heated to 80 to 140 ° C. and then b) amines of the general formula (I) NR ¹ R ² R ³ (I) in which R ¹ , R ² , R ³ independently of one another represent a hydrogen atom, an alkyl radical having 1 to 22 C atoms or a hydroxylalkyl radical having 1 to 22 C atoms and at least one hydroxyl group or an aminoalkyl radical having 1 to 22 C atoms , with the proviso that at least one of the radicals represents a hydroxyl alkyl radical having 1 to 22 C atoms or an aminoalkyl radical having 1 to 22 C atoms, in a molar ratio (I): (II) of 1: 1 to 1: 3 , A process for the preparation of additives according to claim 14, characterized in that after the reaction steps a) and b), the reaction products are treated in a further step with dicarboxylic acids of the formula (III) HOOC-R ⁵ -COOH (III) in which R ^{5 represents} a divalent, branched or unbranched, saturated or unsaturated alkyl radical having 2 to 21 carbon atoms, at temperatures from 100 to 200 ° C in a molar ratio of reaction products to dicarboxylic acids of the formula (III) from 100: 1 to 1: 1 to the end products.