DE2519577A1 - ADDITIVES AND THE FUELS AND FUELS CONTAINING THEM - Google Patents

Description

Additives and fuels containing them The invention relates to hydrogenated alkyl aromatics and their use for improving cold flow properties vo petroleum), especially distillate fuel oils.

Kerosene, which is a solvent for wax, has traditionally been one Component of distillate fuel oils, e.g. of diesel fuels, heating oils etc. With the use of kerosene in aircraft fuel, the amount of kerosene has increased decreased over time in medium and heavy distillate oils. That in turn did it required modifiers for the fuels Wax crystals, E.g. pouring point lowerers, added to compensate for the lack of kerosene.

One class of such pour point depressants are alkylated aromatics, especially those of the wax naphthalene type.

These substances are used in numerous petroleum, e.g. lubricating oils (see U.S. Patents 1,815,022 and 2,297,292) as dewaxing agents, including use together with other co-additives (cf. US Pat. Nos. 3,417,010 and 3,475 321) and as a pour point depressant for middle distillate fuels (see US Pat 245 366).

Numerous alkyl aromatics are also contained in certain petroleum waxes, such as in the essentially paraffin-free petrolatum described in U.S. Pat 773,478, 3,790,359 and 3,660,057.

Alkyl aromatics are also more common in the paraffinic ones contain microcrystalline waxes. The use of such microcrystalline waxes as a wax crystal modifier for fuels, along with polymeric ethylene Pour point depressants containing pour point depressants is already known and is described, for example, in US-PS 3,250,599, the copolymers of ethylene and vinyl fatty acids, e.g. vinyl acetate, together with a microcrystalline petroleum wax.

U.S. Patent 3,288,577 discloses the use of a microcrystalline petroleum wax together with copolymers of ethylene and vinyl fatty acid esters or copolymers of styrene and C10 to C24 α-olefins, or one by means of Friedel-Crafts reaction obtained condensation product of an aromatic hydrocarbon and a polyunsaturated ester. U.S. Patent 3,445,205 discloses the use of a microcrystalline Wax together with an acrylic acid ester polymer in fuels.

Ethylene type pour point depressants are for middle distillate oils known. For example, the following are described: copolymers of ethylene and numerous others Monomers, e.g.

Copolymers of ethylene and vinyl esters of lower fatty acids such as e.g., vinyl acetate (U.S. Patent 3,048,479); Copolymers of ethylene and alkyl acrylate (CA-PS 676 875); Terpolymers of ethylene, vinyl esters, and alkyl fumarates (U.S. Patent 3,304,261 and 3,341,309); Polymers of ethylene and other lower olefins or homopolymers from ethylene (GB-PS 848 777 and 993 744); chlorinated polyethylene (BE-PS 707 371).

It has now been found that the effectiveness of alkyl aromatics such as e.g. the aforementioned wax naphthalene pour point depressants or those in the aforementioned Petrolatum-containing alkyl aromatics, can be increased if they are hydrogenated; they are then particularly suitable for use in under atmospheric pressure distilled fuels for wax crystal size control and improvement the cold flow properties of the oil.

Many of the above-mentioned and known substances, e.g. the ethylene skeleton lowering point, that have found widespread commercial use, are indeed very effective for reduce the pour point of distillate oils, but often do not decrease them the particle size of the wax crystals that form is sufficient. These big wax crystals tend to seep through the filtering devices of delivery trucks, storage bins, etc. to be filtered out. This leads to the fact that the filters become clogged, although the temperature of the oil is significantly above its pour point.

In general, one advantage of hydrogenated substances is that they especially when used together with substances with an ethylene structure, constantly the Wax crystal size control and that you have so very small crystals receives that pass through said filter devices.

Because of the improved effectiveness for regulating the wax crystal size the additives according to the invention are particularly suitable for use in Diesel fuels because there is a tendency towards the maximum distillation point these diesel fuels increase. The increase in the maximum distillation point leads to the fact that the fuel and propellant obtained have a greater proportion of hydrocarbons with a higher molecular weight, which in turn increases the calorific value (BTU value). This higher calorific value offers economic advantages during operation of diesel engines. However, increasing the maximum distillation point leads to Increase in the pour point and the flocculation point. -The diesel fuels currently in use usually have pour points in the region of -30 ° C. By increasing the distillation temperature the diesel fuels can have pour points down to -15 or -120C or higher. As a result, the flocculation point is also increased. The flocculation point is common a few degrees (2 to 8) higher than the pour point, although it is in some fuels can be up to 15 0C above the pour point.

It is necessary to lower the higher pour point what one achieved by the addition of flow point deniers.

The higher flocculation point generally means that the wax crystals become problematic, so that it is necessary to keep changing the size of the wax crystals to control.

For example, in normal operation of a diesel engine, this is equipped with a mesh filter of about 50 microns. When in cold weather the ambient temperature is below the flocculation point, the forming Wax crystals should be fine enough for them to pass through these filters.

The compositions according to the invention contain a larger part Petroleum, e.g., lubricating oil, residual oil, etc., but preferably one at atmospheric pressure distilled fuel, which is improved in its flow properties by a minor part of a hydrogenated alkyl aromatic. These compositions can also contain an ethylene polymer as a pour point depressant, usually in the proportion of 0.1 to 25, preferably 0.5 to 10 parts by weight of hydrogenated Alkyl aromatic per part by weight of ethylene polymer.

The distillate fuels The distillate fuel oils have generally a boiling point between 120 and 6500C, e.g. between 120 and 4900C. The middle distillate fuels usually have boiling points in the range between 120 and 3700C, while heavy distillate fuels make up a larger proportion of the fuel with a boiling point between 120 and 37000 and a lower proportion with a Final boiling point in the range between 370 and 6500C, e.g. 370 to 490 ° C.

The fuel can be straight run or cracked gas oil or a Mixture in any ratio of straight run and thermal and / or catalytic contain cracked distillates, as well as a mixture of middle distillates and Heavy distillates. The most common petroleum middle distillate fuels are kerosene, Diesel fuels, aviation fuels and heating oils. Heavy distillate fuels are usually diesel fuels for ships and heavy fuels for turbines. The flow problem at low temperatures mostly occurs with diesel fuels and heating oils.

A typical fuel oil composition has a 10 distillation point up to about 230C, a 50% distillation point up to about 2700C and a 90 % Distillation point of at least 280 and not higher than about 340 to 34500, although some specifications have set the 90% point up to 360 ° C.

Requires a typical specification for a diesel fuel a minimum flash point of about 3800 and a 90% distillation point between 280 and 340 ° C (cf.

ASTM designations D-496 and D-975).

One of the heavy distillates used in the examples has one 90% distillation point of about 390 ° C and a final boiling point (FBP) of about 4530C (ASTM-D-1160).

The alkyl aromatics These substances, e.g. aromatic wax condensates, are as usual by means of Friedel-Crafts condensation of a halogenated paraffin or olefins made with an aromatic hydrocarbon. These substances are well known, particularly as pour point depressants for lubricating oils and as Dewaxing agents. The halogenated paraffin usually contains from about 15 to about 60 carbon atoms and about 5 to about 25 weight percent, e.g. 10 to 18 weight percent, chlorine. These halogenated paraffins used in the manufacture of the well-known class of wax crystal modifiers are used, are themselves usually prepared by using a paraffin wax having a melting point between about 35 and 950C up to that given above Chlorine content chlorinated. The aromatic hydrocarbon used usually has a maximum of 3 substituent groups and / or condensed rings and may be a hydroxy compound such as phenol, cresol, xylenol, or a Amine such as

Aniline; it is preferably naphthalene, phenanthrene or anthracene.

Another source of alkyl aromatics of the type in question are certain petrolata (microcrystalline or amorphous solids) with melting points between about 26 and 93 0C or higher and number average molecular weights between about 500 and 3000, for example 600 to 2500, preferably 600 to 1500. These molecular weights are above those of those substances normally found in middle distillate fuels are present, which averages around 240 and rarely up to 400.

The microcrystalline petroleum wax includes such hydrocarbon waxes normally obtained from heavy lubricating oil fractions that are obtained from paraffin and mixed base crude oils; these waxes have a fine, less noticeable crystalline structure than paraffin wax. The wax can contain up to 40% oil, mostly about 5 to 25% by weight, -or it can be in more in refined or de-oiled form. In the manufacture of the microcrystalline The heavy lubricating oil can initially undergo a dissolving deasphalting, a Solvent refining with phenol or other aromatic-selective solvents or a water treatment (hydrotreating), and that can be then the normal dewaxing and de-oiling procedures to make the wax connect. Dewaxing can be done using any of a number of suitable methods such as solvent extraction at low temperatures, followed by crystallization and separation by centrifugation or by dissolving Dewaxing with methyl ethyl ketone -Solutions. The petrolatum wax obtained can be further entolted if desired, e.g. by treatment with methyl ethyl ketone, so as to obtain a variety of microcrystalline waxes. The wax can too are obtained as sweat wax (foots waxes) or sweat oil (foots oils), namely during the manufacture of the other microcrystalline waxes.

While microcrystalline waxes can be used, they are due the generally increased effectiveness, preferred wax materials are those that are amorphous Solids and essentially free of normal paraffinic hydrocarbons are. That is, they generally become less than 5% by weight, preferably less contain as 1% by weight normal paraffinic hydrocarbons.

These amorphous hydrocarbon fractions can be obtained by deasphalting a residual oil fraction; then a solvent becomes too given the deasphalted residue, the temperature of the solvent diluted residue is reduced, then the desired solid or semi-solid Material obtained by precipitation at low temperature and then finally filtered. The said residual oil fraction usually has a viscosity of at least 125 SUS (Saybolt seconds) at 99 0C. In some cases, the Products depending on the raw material source have a low content of paraffin hydrocarbons to have. E.g. by treating a deasphalted residual oil from certain Texas crude oils containing propane at low temperatures have a high precipitated fraction Molecular weight can be obtained that contains only a trace of normal paraffins, about 5 »isoparaffins, contains about 73% cycloparaffins and about 22% aromatic hydrocarbons.

In the following working examples, the wax used was A such an amorphous solid hydrocarbon fraction with a melting point of 430C; it was obtained by means of propane precipitation from a deasphalted residue from a Texas coastal crude oil. Using mass spectrographic Analysis and gas chromatography found that this hydrocarbon fraction about 5% by weight isoparaffins, 22% by weight aromatic hydrocarbons, 73% by weight Cycloparaffins and contained no more than a trace of normal paraffins. The number averaged The molecular weight of this material was about 775 as determined by vapor pressure osmometry (Vapor Pressure Osmometry, VPO). The distillation characteristics of these solid amorphous hydrocarbon fraction were as follows: (ASTM-D-1160) Steam Temp. Steam temp.

5 5 mm Hg. To atmospheric pressure ~~~~~~~~~~~~ pressure converted to initial boiling point 2280C 385 0C point 5% 310 496 10 Z 335 525 20% 363 557 24% 366 558 Only 24% distilled above; 75X dregs, 1% loss.

These petrolata can be hydrogenated per se by removing their alkyl aromatic content hydrogenated. The alkyl aromatic fraction can also first be separated from the wax and then be hydrogenated.

For example, the wax A described above can be prepared by conventional methods into an aromatic hydrocarbon fraction (22%) and one non-aromatic hydrocarbon fraction (78%) are separated by a silica gel separation method in which the original wax, e.g. wax A, is dissolved in 5 to 25 parts by weight of normal heptane per part by weight of wax. the The solution obtained is passed through a column of silica gel; the column is then rinsed with 100 to 500 parts by weight of normal heptane to remove the non-aromatics to remove. The aromatics that were adsorbed in the column are then recovered, by washing the column with 50 to 500 parts of acetone and then evaporating the acetone; the alkyl aromatic fraction is obtained in this way.

Process conditions for the hydrogenation The hydrogenation of the alkyl aromatics is carried out using conventional methods. The alkyl aromatic is preferred diluted with an inert solvent, usually with hydrocarbons such as Heptane, cyclohexane, aliphatic naphtha, etc. together with a hydrogenation catalyst it is placed in a high pressure autoclave, with hydrogen to about 35 bis 700 kg / cm, preferably 140 to 282 kg / cm2, pressed and then to 230 to 4000C, preferably 300 to 3700C, for about 1 to 24 hours, e.g. 2 to 10 hours, heated, while stirring. Preferably hydrogen is passed through during the reaction a pressure regulating valve is added to maintain the desired pressure. After the hydrogenation has ended, the pressure in the reaction vessel is relieved, the catalyst is removed by filtering and the hydrogenated alkyl aromatic is removed from the solvent simply obtained by evaporation of the solvent.

The hydrogenation catalyst is generally used in amounts from 0.1 to 20% by weight, e.g. 5 to 10% by weight, based on the weight of the too hydrogenating alkyl aromatics, depending on the specific catalyst used. In the absence of sulfur compounds, the usual hydrogenation catalysts are E.g. the following: Raney nickel, platinum oxide, platinum on aluminum, palladium on activated carbon, Copper chromate, nickel on diatomaceous earth, molybdenum etc. If sulfur is an impurity is present, then cobalt molybdate or nickel tungstate are the preferred catalysts, as they resist sulfur poisoning.

The pour point depressant with an ethylene structure in general have these polymeric pour point depressant a polyethylene framework, which is formed by hydrocarbon or oxy-hydrocarbon side chains are divided into segments. In general they contain about 3 to 40, preferably 4 to 20, molar proportions of ethylene per molar Proportion of a second ethylenically unsaturated monomer; this latter monomer can be a single monomer or a mixture of such monomers in each Relationship. These oil-soluble polymers generally have a number average Molecular weight between about 500 and 50,000, preferably between about 1,000 and 5000, measured e.g. with a vapor pressure osmometer such as echrolab Vapor Pressure Osmometer Model 310A't.

The unsaturated monomers copolymerizable with ethylene include unsaturated mono- and diesters of the following general formula: In this formula, the symbols have the following meanings: R1 = hydrogen or a methyl group, R2 = -OOCR4 or -COOR4, where R4 is hydrogen or a C1 to C16), preferably C1 to C11, straight or branched chain alkyl group, R3 = hydrogen or -COOR11.

When R1 and R3 are hydrogen and R2 is -00CR4, the monomers include Vinyl alcohol esters of C2 to C17 monocarboxylic acids, preferably of C2 to C5 monocarboxylic acids. Examples of such esters are: vinyl acetate, vinyl isobutyrate, vinyl laurate, vinyl myristate, Vinyl palmitate etc. When R2 is -COOR4, the esters are e.g. methyl acrylate, Isobutyl acrylate, methyl methacrylate, lauryl acrylate, C13 oxo alcohol ester of methacrylic acid, etc. Examples of monomers in which R1 is hydrogen and R2 and R3 are -COOR4, are: mono- and diesters of unsaturated dicarboxylic acids, such as: mono-C13-oxofumarate, Di-C13-oxofumarate, di-isopropyl maleate, di-lauryl fumarate, ethyl methyl fumarate, etc.

Another class of monomers that copolymerizes with ethylene include C3 through C16 K monoolefins that are either straight or branched chain can be, such as propylene, isobutene, N-octene-1, isooctene-1, N-decene-1, dodecene-1, etc.

Another monomer is vinyl chloride, albeit essentially the same results can be obtained using chlorinated polyethylene. A branched-chain polyethylene as such can also be used as a pour point depressant be used.

These polymeric pour point depressants are generally manufactured by using a substance that is free Forms radicals. In in some cases they can also be produced by thermal polymerization or, in the case of ethylene with other olefins, by Ziegler polymerization. the Polymers derived from free radicals appear to be the most important and they can be prepared as follows: The solvent and 0 to 50% by weight of the total Amount of the monomer used for the batch that is not ethylene (e.g. a Ester Monomer), are placed in a stainless steel pressure vessel, the is equipped with a stirrer and a cooling coil. The temperature of the pressure vessel is then brought to the desired reaction temperature, e.g. 70 to 2500C, and with ethylene to the desired pressure, e.g. 55 to 700 kg / cm2, usually 60 to 430 kg / cm2. Then the radical promoter, usually diluted with the reaction solvent, and additional amounts of the second monomer, e.g. unsaturated ester, continuously or at least at certain intervals during the reaction time initiated in the boiler; this continuous addition results a more homogeneous copolymer than having all of the unsaturated ester on The beginning of the reaction admits. Even during this reaction time, during the ethylene is consumed in the polymerization, additional ethylene is added, and although by a pressure-controlling regulator, so the reaction pressure over to keep the time constant enough. After the reaction has ended - usually 1/4 to 10 hours are sufficient - the liquid products are removed from the pressure vessel, and the solvent is drawn off, the polymer remaining as a residue. Around The polymer will facilitate handling and subsequent mixing with oil usually dissolved in a light mineral oil; you get such a concentrate with usually 10 to 16% by weight of polymers.

Based on 100 parts by weight of copolymer to be prepared, im generally 50 to 1220, preferably 100 to 600, parts by weight of solvent, e.g. hydrocarbons such as benzene, hexane, cyclohexane etc. and about 0.1 to 20, e.g. 1 to 5 parts by weight of promoter used.

The promoter can be any of the conventional radical promoters such as peroxide or azo compounds including the acyl peroxides of C2 to C18 straight or branched chain carboxylic acids, alkyl peroxides, etc., including Di-benzoyl peroxide, di-tert-butyl peroxide, di-tert-butyl perbenzoate, tert-butyl hydroperoxide, d, t-azodiisobutyronitrile, dilauroyl peroxide, etc.

The oil compositions according to the invention generally contain a larger amount of oil, e.g. distillate fuel oil, and about 0.01 to 3% by weight, preferably from 0.05 to 0.5% by weight of the hydrogenated alkyl aromatic. In addition, the Composition about 0.001 to 2% by weight, preferably 0.005 to 0> 15% by weight of the contain the aforementioned pour point depressant with ethylene skeleton. You can use an oil concentrate with 3 to 60% by weight of said hydrogenated material, with or without said Making ethylene material, e.g. in a distillate fuel, for handling to facilitate. The percentages by weight are based on the weight of the entire composition.

The invention is explained in more detail by the following examples, in which the following substances have been used.

Hydrogenated wax naphthalene Wax naphthalene, made from 100 Parts by weight of n-paraffin with a melting point of about 53 C, chlorinated on 12% by weight of chlorine and condensed with 14 parts of naphthalene (Friedel-Crafts condensation) was hydrogenated as follows: 10 g of the wax naphthalene, 0.2 g carbon disulfide (um to keep the catalyst sulfated), a hydrogenation catalyst consisting of 10 Sulphated Nalco-471 g and 10 g sulphated Nalco NT-550 were placed in a pressure kettle given and heated with stirring to a temperature of about 350 ° C for 6 hours. Approximately 17 g of the hydrogenated product was recovered after filtering the catalyst and stripping off the solvent. The named Nalco-471 was a cobalt (3.5%) molybdate (12.5S) on aluminum. The Nalco NT-550 mentioned was nickel (4%) - tungstate (16 %) on aluminum.

Hydrogenated Alkyl Aromatics from Petrolatum The aromatic fraction of the The wax A described above was extracted as follows: 100 g of wax A were in 500 ml of normal heptane dissolved, and the resulting solution was poured through a glass column, which was about 2.5 m long and about 5 cm in diameter and with a 60/100 Mesh silica gel (Davidson) was filled.

The saturated portion of the petrolatum was removed from the column with n-heptane eluted until the pure solvent passed through. Those adsorbed in the column Aromatics were then recovered by washing the column with about 5 liters of acetone and then separated the acetone from the resulting solution.

In this way, 22 g of the aromatic fraction was obtained.

The aromatic fraction was analyzed by mass spectrometry; it contained 22.7% by weight of hinci ring alkyl aromatics, during the Rest of multiple ring compounds star, -in part of the aromatic described above Fraction was hydrogenated as follows: 10 S of the aromatic fraction, 092 g of carbon disulfide, 10 z of Nalco-471 and 10 g of Nalco-550 were placed in an autoclave, and the autoclave was pressurized to 212 kg / cm2 with hydrogen and for 6 hours heated to 350 ° C. After completion of the realization, the solvent and the Catalyst removed and 9 g of product remained.

The ethylene backbone polymer copolymer A was an irregular ethylene-vinyl acetate copolymer with a number average molecular weight of about 1900 (determined by vapor phase osmometry), which has about 1.5 side chains terminated with methyl (not including the methyl groups of vinyl acetate) per 1000 molecular weight Polymer and about 38 weight percent vinyl acetate. The copolymer was made by copolymerization of ethylene and vinyl acetate with dilauroyl peroxide at a Temperature of about 105 ° C and under an ethylene pressure of about 74 kg / cm2 in cyelohexane as a solvent. A typical laboratory production of this polymer runs like this follows: A three-liter autoclave is stirred with about 1000 ml of cyclohexane as Solvent and about 100 ml of vinyl acetate charged. The autoclave is then using Nitrogen and then flushed with ethylene, then the autoclave is heated to 105 ° C, while ethylene is introduced until the pressure reaches about 74 kg'cm2. Then will while maintaining this temperature and pressure approximately 160 ml / hour of vinyl acetate and about 80 ml / hour of a solution of 9% by weight of di-lauroyl peroxide in 91 wt .-% cyclohexane is pumped continuously and evenly into the autoclave. A total of 320 ml of vinyl acetate and 11 g of peroxide were poured into the reactor over a period of 2 hours injected. After the last remainder of the peroxide has been injected, the batch held at 1050G for an additional 10 minutes. Then the temperature of the reactor contents lowered to about 600C, the pressure is released from the reactor and the contents is taken out of the autoclave. The empty reaction vessel is filled with 1 l warm (approx. 500C) washed benzene, which is added to the product. The product will then of solvent and unreacted monomers overnight on a steam bath freed by blowing nitrogen through the product.

Further examples of this class of polymers can be found in the CA-PS 882 194. Details of the determination of the branching of these polymers are in Journal of Applied Polymer Science, Vol. 15, pp. 1737-1742 (1971).

Copolymer B was an irregular ethylene-vinyl acetate copolymer having a number average molecular weight of about 4100, the contained about 9 wt .-% vinyl acetate and a specific viscosity (measured in a 1% by weight solution in toluene at 380 ° C.) of about 0.37.

The fuels and fuels Fuel A was a diesel fuel with a flocculation point of -13.3 ° C (ASTM) and a boiling point in the range of about 175-340 ° C (ASTM-D86); the aniline point was 620c.

Fuel B was a diesel fuel with a flocculation point of -13.9 ° C (ASTM), a boiling range between 199 and 340 ° C (ASTM-D86) and an aniline point of 58 ° C.

Fuel C was a diesel fuel with a flocculation point of + 4.4 ° C (ASTM) and an aniline point of 74 ° C; the distillation characteristics (ASTM D-1160) were the following: initial ice point 179 ° C 5% 195 ° C 10% 203 ° C 50% 2849C 90% 390 ° C. 95% 416 ° C. final boiling point 453 ° C. The following flow tests were used for Determination of the cold flow properties of the waxy fuels.

Flow test A In this experiment, a 200 ml ProDe of the oil is raised by 2.2 ° C cooled to -20.10C or -23.3 ° C per hour, starting at 5.60C above the flocculation point of the oil.

At the temperature of -20.1 ° C or -23.30C, the oil is left with a Vacuum of 91.14 cm water column through a 270 mesh screen and 1 cm in diameter. The percentage of the sample that goes through in 25 seconds is determined.

Flow test A 'This test is carried out in the same way like experiment A with the exception that the finest mesh is determined which the oil passes in 25 seconds at -20.10C.

Flow test B This test is carried out according to a method this is described in "Journal of the Institute of Petroleum", Vol. 52, No. 510, June 1966, pp. 173-185. The test is carried out on a 45 ml sample of the oil in an ASTM pour point device cooled in a bath maintained at about -35 ° C will. After every degree of temperature drop, starting at 20C above the flocculation point, the oil is passed through a filter under a suction pressure of about 20 cm water column, equipped with a 350 mesh screen, into a pipette sucked up to the 20 ml mark; the oil is released by gravity flow back into the cooling chamber. The experiment is carried out in the event of a temperature drop of the oil is repeated by 10 until the oil no longer opens the pipette within 60 seconds the aforementioned mark fills. The results of this experiment are recorded than the highest temperature at which the oil no longer fills the pipette.

Mixtures of the aforementioned materials in the aforementioned fuels were produced and tested according to the flow test described. the The results obtained are shown in the following tables.

TABLE I Flow Test A% fuel recovery from additive in fuel A -20.1 ° C -23.3 ° C 0.045% by weight wax naphthalene) 0 0 0.045% by weight copolymer A) 0.135% by weight wax-naphthalene) 100 60 0.045% by weight copolymer A) 0.018% by weight wax-naphthalene) 100 85 0.09% by weight of copolymer A) 0.045% by weight of hydrogenated) wax-naphthalene) 100 100 0.045 wt% copolymer A) None 0 0 TABLE II Flow Test A Additive in Fuel B% recovery at -23.3 ° C. 0.135% by weight of copolymer A 1 0.045% by weight of copolymer A 0.4% by weight of aromatic fraction) 0 0.045% by weight of copolymers A 0.4% by weight of hydrogenated aromatisebe @ 100 Fraction None 0 TABLE III @ lettest A 'Flow test B additive in fuel @ Mas @@ number of @assierten network @ ° C 0.0225 wt .-% copolymer @ @@ -3.3 0.0225% by weight hy @@@ ertes @ achs-Nap @@@@@@@@ @@ -1, @ 0.0112% by weight @y @@@ ertes Wax-after @@@@@ @@ -6, @ 0.0112% by weight copolymer @ none @@ +1.1 As As can be seen from Table I, the wax naphthalene and the ethylene-vinyl acetate were pour point depressants (Copolymer A) ineffective per se at a concentration of 0.045% by weight in fuel A at -20.1 ° C and -23.3 ° C.

By increasing the proportion of wax naphthalene from 0.045 to 0.135 % By weight, 100% passage was achieved at -20.1 ° C. and 60% passage at -23.30C. By further increasing the proportion of wax naphthalene and copolymer A, the pass value was increased to 85% at -23.30C. However, the final composition resulted of Table I with 0.045% hydrogenated wax naphthalene and copolymer A each 100% passage at both -20.1 ° C and -23.3 ° C. The @ eleg @ @ i @ improved results obtained from hydrogenation. According to the table II consisted of the aromatic fraction together with the copolymer A in the fuel B failed the flow test at -23.3 ° C, but did use the hydrogenated aromatic Fraction 100% passing. This also proves the increased effectiveness of the control the wax crystal size that is achieved by hydrogenating the alkyl aromatics. Tabel III shows that the hydrogenated wax naphthalene was suitable per se, the wax crystal size to control, and that the combination of hydrogenated wax-naphthalene and copolymer B - as the flow test B shows - was even more effective, as can be seen from the high temperatures for clogging the mesh network.

Claims (10)

Claims 1. Additive concentrate to improve the flow properties of Fuel oils, containing an oil solution of a mixture with a content from 3 to 60% by weight of a hydrogenated alkyl aromatic of the following type: (a) a hydrogenated one Wax-naphthalene pour point depressant as Friedel-Crafts condensation product a wax with a melting point between 35 and 950C that has a chlorine content from 5 to 25% by weight of chlorine is chlorinated, and from naphthalene, in a relative Weight ratio of 5 to 15 parts chlorinated wax per part aromatic; or (b) a hydrogenated alkyl aromatic fraction of an amorphous, normally solid wax with a molecular weight between 600 and 3000 and obtained from residual petroleum and containing a pour point depressant with an ethylene skeleton; and containing a Pour point depressants with an ethylene structure and a molecular weight between 500 and 50,000 of the following types: (1) branched chain polyethylenes or (2) to 1 up to 30% by weight of chlorinated ethylene polymers, or (3) copolymers of 3 to 40 molar proportions of ethylene with a C3 to C16 monoolefin or a monoethylene unsaturated mono- or dialkyl esters with 1 to 16 carbon atoms in the alkyl groups, wherein the relative weight ratio of the hydrogenated alkyl aromatic to the pour point depressant with ethylene structure between 0.1 to 25 parts by weight of hydrogenated alkyl aromatic per Part of the pour point depressant. 2. Concentrate according to claim 1, characterized in that the hydrogenated The alkyl aromatic is a hydrogenated wax naphthalene pour point depressant and the pour point depressant with Äthylengerüst a copolymer of 4 to 20 molar parts of ethylene with a molar part of vinyl acetate and a molecular weight between 500 and 50,000. 3. Concentrate according to claim 1, characterized in that the hydrogenated Alkyl aromatic a hydrogenated alkyl aromatic fraction from an amorphous, normally solid wax and that the pour point depressant with ethylene skeleton is a copolymer from 4 to 20 molar parts of ethylene with one molar part of vinyl acetate, with one Molecular weight between 1000 and 5000 for the copolymer. 4. Distillate fuel oils with a boiling point between 120 and 6500C, containing 0.01 to 3% by weight of a flow property improving hydrogenated alkyl aromatic fraction of an amorphous, normally solid wax, which has a melting point between 25 and 950C and a molecular weight between 600 and 3000 and is obtained from residual petroleum. 5. Composition according to claim 4, characterized in that it an alkyl aromatic of the following types (a) hydrogenated wax-aromatic pour point depressants as Friedel-Crafts condensation product of a wax with a melting point between 5 and g5 ° t which is chlorinated to a chlorine content of 5 to 5% by weight. and from an aromatic n in a relative weight ratio of 5 up to 15 parts of chlorinated wax per part of aromatic; or hydrogenated alkyl aromatic fraction nes amcrpXsen, usually solid wax that has a melting point between 25 and 95 0C and a molecular weight between 600 and 3000 and made from residual petroleum is obtained, and also contains 0.001 to 2 wt .-% of a pour point depressant with an ethylene structure, which has a molecular weight between 500 and 50,000 and made of (1) branched-chain polyethylenes, or (2) chlorinated to 1 to 30% by weight of chlorine Ethylene polymers, or (3) copolymers of 3 to 40 molar parts of ethylene with a C3 to C16 K monoolefin or a monoethylenically unsaturated mono- or Dialkyl esters with 1 to 16 carbon atoms in the alkyl groups, and where the relative Ratio of hydrogenated alkyl aromatics to pour point depressants with an ethylene structure 0.1 to 25 parts by weight of hydrogenated alkyl aromatic per part of pour point depressant amounts to. 6. Composition according to claim 5, characterized in that the Hydrogenated alkyl aromatic is hydrogenated wax naphthalene and the pour point depressant with Äthylengerüst a copolymer of 4 to 20 molar parts of ethylene with a molar part of unsaturated alkyl ester. 7. Composition according to claim 6, characterized in that the unsaturated ester is a vinyl ester of a C2 to C5 fatty acid. 8. The composition according to claim 7, characterized in that the Ester is vinyl acetate. 9. Composition according to claims 4 to 8, characterized in that that the hydrogenated alkyl aromatic is a hydrogenated Alkyl aromatic fraction from amorphous, normally solid waxes with a molecular weight between 600 and 2500 and is essentially free of normal paraffinic, hydrocarbon / and that the pour point depressant with an ethylene skeleton is a copolymer of ethylene and unsaturated alkyl ester. 10. Composition according to claims 4 to 9, characterized in that that the copolymer has a molecular weight of 1,000 to 5,000.