DE2207145C2 - Flow improvers - for middle distillate fuel having increased low temp flowability - Google Patents

Abstract

Wax-contg. petroleum distillate fuel (b.pt. 250-700 degrees F) having improved low temp. flow props. is obtd. by adding 1) 0.1-3.0 wt% satd. hydrocarbon fraction of av. mol. wt. 600-3000, the fraction being fee of normal paraffin hydrocarbons, and 2) 0.005-1.0 wt.% wax-modifying random copolymer of 3-40 molar portions ethylene and 1 molar portion unsatd. ester, the copolymer having av. mol. wt. 1000-50000 and having 6 methyl-terminating side branches on the polyethylene backbone per 100 methylene gps.

Description

The invention relates to the fuel or fuel mixture described in the claims.
Heating oil and other petroleum middle distillate fuels, for example diesel fuels, contain n-paraffinic hydrocarbon waxes which easily precipitate in large crystals at low temperatures, so that a gel structure is formed, due to which the fuel loses its fluidity. The lowest temperature at which the fuel still flows is commonly known as the pour point. If the temperature of the fuel or fuel reaches this point or is below it, so that the fuel or fuel is no longer flowable, difficulties arise when transporting the fuel or fuel through lines and pumps, for example when the fuel or fuel Fuel is to be transferred from one storage container to another with the help of gravity or with a pump or to be directed into a burner. In addition, the wax crystals that have separated out of the solution tend to clog fuel lines, strainers and filters. This problem has been recognized in the past and various additives have been proposed to lower the pour point of the fuel oil. One function of such pour point depressants was to change the size of the crystals precipitating from the fuel or fuel oil, thereby reducing the tendency of the wax crystals to gel. Small crystals are therefore desirable so that the precipitated wax does not clog the fine-meshed sieves in the transport, storage and distribution facilities.

From DE-OS 19 01 143 a process for the production of heating oils or heating oil components is known in which a residual oil of a normal petroleum distillation is distilled in vacuo, the wax distillate fraction obtained with a boiling range of 320 to 600 ⁰ C with a reduction of its wax content by at least 4 % is selectively dewaxed and finally at least part of the dewaxed wax distillate is mixed with at least part of the vacuum residue to form a heating oil. The heating oil obtained in this way consists only of components of residual oil and is a heavy heating oil with a high boiling range, the wax content of which was not specially selected, but only partially reduced in a laborious process.

From US-PS 32 50 599 and 32 88 577 it is known, a hydrocarbon fuel or propellant oil distillate add microcrystalline wax or a petrolatum. However, it has been shown that the petrolatum or the microcrystalline wax alone contributes to the pumpability or filterability of a waxy petroleum distillate insufficiently improved at low temperatures. In addition, the petrolatum or the microcrystalline wax does not lower the pour point, but the pour point of the fuel or fuel oil, to which they are added is even increased in some cases.

From US-PS 34 45 205 are fuel mixtures with improved flow properties and pour points known by adding 0.1 to 1% of a certain, from one from the middle of American Crude oil derived from the continent, microcrystalline wax and 0.001 to 0.1% of an acrylic ester polymer having a molecular weight of 500 to 20,000 to the petroleum distillate fuel were obtained. The microcrystalline wax used as an additive according to US-PS 34 45 205 However, it contained larger amounts of n-paraffins and as such was not able to reduce the pour point of the fuel to humiliate.

The invention is based on the object of providing a fuel or fuel mixture with a boiling range of 121 to 371 ° C on the basis of a petroleum middle distillate, consisting of a waxy petroleum distillate, 0.01 to 3 wt .-% of a normally solid petroleum hydrocarbon fraction with a melting range of 26.7 to 60 ⁰ C and 0.001 to 1 wt ° / o to provide a polymeric Stockpunktserniedrigers having an average molecular weight (number average) from 1000 to 50,000, having a reduced pour point and an improved filterability at low temperatures in an improved combination .

According to the invention, this object is achieved in that the fuel or fuel mixture is used as the pour point and a low temperature flow improving solid petroleum hydrocarbon fraction Amorphous and substantially saturated petroleum fraction obtained from a petroleum residue oil with a average molecular weight (number average) from 600 to 3000 and a content of n-paraffin hydrocarbons of not more than 5% by weight and, as a polymeric pour point depressant, a copolymer of Contains ethylene and vinyl acetate with a content of 3 to 40 molar parts of ethylene per molar part of vinyl acetate.

Those used according to the invention together with the copolymer of ethylene and vinyl acetate as an additive Paraffinic hydrocarbon fraction (preferably a naturally occurring fraction), which is preferably 3% by weight or less, in particular not more than 1% by weight, n-paraffin hydrocarbons and is added preferably in a concentration of 0.1 to 2 wt .-%, lowers the pour point of the fuel or fuel oil, changes the wax crystal structure and enables the fuel or fuel to also be used Much lower temperatures can flow through the sieves than would be the case without the addition of this paraffin fraction it is possible. The active constituents of the fraction free of η-paraffin can either be isoparaffins or cyclo-paraffins or mixtures thereof.

It is believed that the incorporation of the amorphous, saturated hydrocarbon fraction is such Has an effect on the molecules of the n-paraffin hydrocarbons present in the fuel or fuel oil, that their tendency to crystallize is reduced.

The fuel or propellant oil distillate can simply be distilled oil, crude gas oil or cracked gas oil or a mixture from simply distilled and thermally and / or catalytically cracked distillates in any ratio include.

The best-known petroleum middle distillate fuels are kerosene, diesel fuels, jet fuels and heating oils. Since the jet fuels are usually refined to a very low pour point, there is generally no need to apply the present invention to these fuels. The problem of fluidity at low temperatures usually occurs with diesel fuels and Heating oils on.

An amorphous hydrocarbon fraction, which has proven to be a means of the invention for improving the The flowability of fuel or fuel oil can be obtained by adding a residual petroleum fraction deasphalted and then a solvent such as propane is added, the temperature of the with the Solvent diluted residue decreased and the desired solid or semi-solid amorphous product wins by precipitation and subsequent filtration. The residual oil fractions that make up the desired Amorphous hydrocarbons obtained have viscosities of at least 26.1 cSt at 99 ° C. The The molecular weight range of the amorphous hydrocarbons is above the highest molecular weight of the Hydrocarbons that are naturally present in the fuel or propellant oil.

In some cases, the products obtained by this process are inherently low in nature Content of normal paraffin hydrocarbons and can be used without further treatment according to the present Invention can be used. In other cases it is necessary to use the high molecular weight fraction to be treated in any known manner in order to reduce the content of normal paraffins.

According to the present invention, the effect of the high molecular weight hydrocarbon fraction becomes for improvement the flow properties of the fuel or fuel oil at low temperatures are enhanced by the fact that together with the added hydrocarbon fraction from 0.001 to 1% by weight of a wax-modifying agent Pour point depressant used, which is a copolymer of ethylene and vinyl acetate.

The copolymers used as pour point depressants consist of 3 to 40, preferably 3 to 20 molar parts of ethylene per molar part of vinyl acetate, are soluble in oil and have an average molecular weight in the range from 1000 to 50,000, preferably from 1500 to 5000. The molecular weights can be determined by cryoscopy or by vapor phase osmometry. Ethylene copolymers in which the number of terminal methyl side chains per 100 methylene groups of the copolymer is not more than about 6 are particularly suitable. These copolymers are prepared by copolymerization of the monomers in an inert solvent such as benzene or hexane at a temperature of about 70 to 13O ⁰ C using a free radical generating catalyst having a half life of less than 1 hour at 130 ° C, for example dilauroyl peroxide, .

All known processes for polymer production can be used to produce the copolymer or pour point depressant be used. According to a preferred embodiment of the present invention the waxy petroleum middle distillate fuel with 0.01 to 0.1 wt% of the copolymeric agent for Improvement in flow properties (flow property improvers) and 0.01 to 0.099% by weight Hydrocarbon fraction added. These percentages by weight refer to the entire fuel or fuel mixture.

According to another preferred embodiment of the present invention, the waxy petroleum middle distillate fuel is or fuel with 0.1 to 3% by weight, preferably 0.2 to 1% by weight, of the hydrocarbon fraction with high molecular weight and 0.005 to 1 wt .-%, generally 0.01 to 0.1 wt .-%, of the as Pour point lower related ethylene-vinyl acetate copolymers added.

Preliminary test 1

By mass spectrographic analysis and gas chromatography, it was found that an amorphous hydrocarbon fraction (Melting point 43.6 ° C) from the deasphalted residue of a crude oil from the coast Texas recovered, 5% w / w isoparaffins, 22% w / w aromatic hydrocarbons, 73% cyclo-paraffins and contained only a trace of normal paraffinic hydrocarbons. The average molecular weight The number average of this material was about 775 as determined by osmometry.

This solid hydrocarbon fraction had the following distillation properties:

distillation Steam temperature Steam temperature at (ASTM D-1160) at 5 mm Hg Normal pressure (converted) Initial boiling point 228 ° C 401 ° C 5% 310 ° C 496.5 ° C 10% 336 ° C 526 ° C 20% 364 ° C 556.5 ° C 24% 365.5 ° C 558.5 ° C

Only 24% distilled over.

There was 75% sump and the loss was 1%.

The samples listed below of five different heating oils were made with various small Concentrations of this amorphous hydrocarbon fraction are added (all percentages referring to the Refer to volume):

oil A: boiling range 184.5-327 ° C; 100% recycled catalytic material;

oil B: boiling range 176.5-332 ° C; 80% catalytic cycle material - 20% heavy crude naphtha;

oil C: boiling range 175.5-349 ° C; 65% recycled catalytic material - 20% kerosene - 15% raw naphtha;

Oil D: boiling range 173-344 ° C; 85% catalytic cycle material - 15% raw naphtha;

Oil E: boiling range 186.5-345 ° C; 80% catalytic cycle material - 20% raw naphtha.

Each of the fuel oil blends and each of the fuel oils without further addition was subjected to two different flow tests subjected at low temperature. One of these tests, a so-called PFT test (programmed fluidity test (programmed fluidity test) was carried out as follows:

A 40 ml sample of the oil to be tested was placed in an hourglass-shaped device, the one has upper and lower sections, the sections passing through an opening with a diameter 2.25 mm and the opening is initially closed by a thin aluminum disc was. The test jar containing the oil was placed in a cold container and the oil was washed with a Speed of 2.22 ° C / hour. from a temperature lying 5.55 ° C above the flocculation point -23.3 ° C cooled. The test jar was inverted and the oil allowed to settle for one minute. then the aluminum disc was pierced so that the oil from the upper chamber through the opening into the lower chamber flowed. The oil had passed the test if at least 85% by volume of the oil was within three Minutes or less had flowed from the upper chamber to the lower chamber.

The other low temperature flow test, called a low filterability test Temperature, was carried out as follows: A 200 ml sample of the oil was controlled with a Speed of 2.22 ° C / hour. cooled to a temperature of either -23.3 ° C or -28.9 ° C which were the temperatures at which the flow test was carried out. Then one left the oil through a sieve for 25 seconds only under the influence of gravity at the test temperature a clear mesh size of 0.84 mm and a diameter of 9 mm. Then the The percentage by volume of the oil that had flowed through the sieve at the end of this time was measured. If more when 85% by volume of the oil had passed through the screen, the oil was considered to have passed the test would have.

The composition of the various oil mixtures examined, theirs measured according to ASTM regulations The pour point as well as the test results obtained in the low temperature flow test are reproduced in Table I below. The percentages by weight of the substances added relate to in any case on the total weight.

Table 1 Addition to Stockpuiikt PFT test Flow rate in the flow test in% around -28.9 ° C Deployed n-paraffin-free according to ASTM -23.3 ⁰ C Filterability test with a 2 oil Hydrocarbon Sieve with a clear mesh 100 substance fraction width of 0.84 ι 0 in% by weight -23.3 ° C 100 0 -17.8 ° C 45 10 100 A. 1.0 95 100 0 A. 0 -17.8 ° C 36 2 B. 0.75 below -37.2 ° C 94 100 100 B. 1.00 at ⁰ C -37.2 94 100 B. 0 -17.8 ° C 18th 1 C. 0.5 93 C. 1.0 100 C.

Table I (continued)

Used oil

Addition of n-paraffin-free hydrocarbon fraction in% by weight

ASTM pour point

PFT test -23.3 "C

Flow rate in the flow test in%
Filterability test with a
Sieve with a mesh size of 0.84 mm
-23.3 ° C -28.9 ° C

E E E E E

0.5

0.75

1.0

2.0

-12.2 ⁰ C -26.1 ° C

-15 ⁰ C -2O.6 ° C

-31.7 ° C below -37.2 ° C

23

34 92 96

0
100

100

100

Preliminary test 2

A mixture of solid hydrocarbons obtained by dewaxing a deasphalted and refined Residual oil was obtained contained, as was shown, 20 wt .-% n-paraffins, 24 wt .-% isoparaffins, 36% by weight cycloparaffins and 20% aromatic hydrocarbons. The hydrocarbon mixture possessed a melting point of 55 "C. The η-paraffins were removed from the mixture as follows: 20 g of des Mixtures were dissolved in 100 ml of a mixture of 2 parts by volume of cyclohexane and 1 part by volume of toluene. The resulting solution was diluted with 300 ml of acetone while stirring. This diluted solution was then A few grams of powdered urea are added each time until a total of 100 g of urea is added had been. After the last addition of urea, the mixture was stirred for a further two hours. The reaction product was then filtered through a Buchner funnel using No. 1 Whatmann filter paper. The slurry collected on the filter paper was mixed with two 160 ml portions of cyclohexane and then washed with two 100 ml portions of toluene, and the wash solutions were mixed with the first Combined filtrate The washing solutions combined with the filtrate were poured into a separatory funnel and Extracted seven times with portions of 100 ml of water to remove any dissolved, if any Remove urea. The hydrocarbon layer from the separatory funnel was then transferred to a still and all solvents were distilled off. The distillation residue, which is 16 g weighed, i.e. 80% of the starting mixture consisting of solid hydrocarbons, was pasty Appearance. The product is hereinafter referred to as n-paraffin-free hydrocarbon mixture A or still more simply referred to as hydrocarbon blend A. The product possessed as determined by osmometry has a number average molecular weight of 817 and a melting point of 45 ° C.

The starting mixture of solid hydrocarbons and the hydrocarbon mixture A were in various weight percent concentrations mixed with the fuel oil E described above. The percentages by weight always refer to the total mixture. Each of the mixtures underwent the programmed fluidity test (PFT) and the filterability test also described above at lower levels Temperature, the latter test being modified to be below -20.5 ° C Use a sieve with a mesh size of 0.59 mm and at -23.3 ° C with a sieve with a clear mesh size of 0.84 mm was carried out. The results thus obtained are shown below Table II reproduced.

Table II

Added hydrocarbon genius in fuel oil E in% by weight of starting mixture mixture A

PFT test -233 ⁰ C

Flow in the flowing part in%

Filterability test

Mesh size Mesh size

0.84mm 0.59mm

-233 ° C -20.5 ⁰ C

04% - 47 0 0.750 / 0 - 51 1 1.0% - 69 5 - 04% 93 94 0.75% 92 100 1.0% 93 100

87

100

From the values in Table II it can be seen that the presence of significant amounts of η-paraffins in the added hydrocarbon mixture caused by the addition of the hydrocarbon mixture Improvement of the flow properties is greatly impaired.

Preliminary test 3

A portion of the output mixture of solid hydrocarbons of the preliminary experiment 2, 20wt .-% η-paraffins contained, was subjected at 2 mm Hg absolute pressure to a final distillation temperature of 343 ⁰ C the vacuum distillation, wherein the Enddampftemperatur was 306 ° C, corresponding to a Corresponding to a temperature of 518.5 ° C at atmospheric pressure. On distillation, about 25% of the material passed over and about 75% sump remained. Analysis of the sump by gas chromatography showed that no n-paraffins were present in the sump. When 0.4% by weight of the sump was mixed with the propellant oil E, a 97% flow rate at -23.3 ° C. was obtained with the mixture in the filterability test described in preliminary experiment 2

ίο through a sieve with a mesh size of 0.59 mm and a 100% flow through at - 17.8 ° C A sieve with a mesh size of 0.42 mm.

Preliminary test 4

A portion of the solid hydrocarbon fraction described in preliminary experiment 1 was in a molecular distillation apparatus at pressures in the range from 5 to 20 μ absolute and at temperatures in the range from 191 Subject to vacuum distillation up to 342 ° C. Several of the fractions obtained in this vacuum distillation were examined for their effectiveness in terms of improving the flow properties of a fuel oil, wherein each 0.75 wt .-% of several fractions in separate portions of the above Fuel oil E were mixed in. The mixtures were then subjected to the PFT test at -23.3 ° C. aside from that a mixture was tested for comparison, which was prepared by the fact that the propellant oil E with 0.75% by weight of a solid hydrocarbon mixture with a melting point of 23.9 ° C. and an average molecular weight of 508 obtained by dewaxing a neutral hydrocarbon distillate with a viscosity of 118.7 cSt measured at 37.8 ° C, was added. As was determined, this was the latter mixture was essentially free of η-paraffins, but contained cycloparaffins, isoparaffins and aromatic ones Hydrocarbons. The results obtained with these different blends, and that Average molecular weights (number average) of the various hydrocarbon fractions are in the shown in Table III below. The 0.75% by weight of added material is in each Case on the total mixture, i.e. the mixtures consisted of 0.75% added material and 99.25% Fuel oil.

Table III

Effect of the molecular weight of the solid hydrocarbons added to the fuel oil.

Vacuum distillation fraction Average molecular weight flow rate in the PFT test

the parliamentary group

1 459 3 535 6th 590 13th 723 21 960 24 1083 solid hydrocarbons made from 508 a hydrocarbon distillate with a viscosity of 550 SUS

0 36

6 590 80

86 93 95 15

From the values in Table III it can be seen that with those solid hydrocarbon mixtures whose molecular weight was below about 590, unsatisfactory results in terms of improving the Flow properties of the fuel oil could be achieved, while those fractions with a molecular weight 590 and higher were effective.

It has been found that the effect of aromatic hydrocarbons is negligible The following experiment shown. The solid hydrocarbon fraction used in preliminary experiment 1 was shown with a silica gel separation process into an aromatic hydrocarbon fraction (22%) and a non-aromatic fraction Hydrocarbon fraction (78%) separated with the hydrocarbon starting mixture in n-heptane dissolved and the solution filtered through a column filled with silica gel; the column was then filled with n-heptane the effluent were combined and the non-aromatics were flushed by evaporation of n-heptane obtained. The aromatics which had been adsorbed in the column were thereby obtained that the column was washed with acetone and the acetone was removed from the resulting solution.

If the aromatic hydrocarbon fraction obtained in this way is used in a fuel oil in concentrations up to 1 wt% added, no improvement in the low temperature flow properties was achieved during the non-aromatic hydrocarbon fraction in terms of improving the flow properties lower temperature was 20% more effective than the starting hydrocarbon mixture, i.e. one To achieve a given degree of flow property improvement, is in the non-aromatic fraction im Compared to the starting mixture, an amount about 20% smaller is required, which indicates that the aromatic hydrocarbons in the starting mixture only exert a diluting effect and that the Non-n-paraffins and the cycloparaffins are effective agents for improving the flow properties of the solid Are hydrocarbon mixture.

example 1

In this example, the best results are those with the 65 wt% ethylene and about 35 wt% Vinyl acetate existing flow property improvers A have been achieved, with the Copolymers as measured by vapor phase osmometry have a number average molecular weight owned by about 2000. This copolymer was made by copolymerizing ethylene and vinyl acetate produced using di-tert-butyl peroxide as initiator (cf. FR-PS 14 61 008). It became the same Hydrocarbon fraction added as in preliminary experiment 1.

Fuel oil mixtures were produced using two separate distillate fuels as the base oil used, which are referred to as base fuel I and base fuel II. The basic fuel I consisted to 100% of a single distilled fuel, while the base fuel II to 60% consisted of simply distilled material and 40% cracked oil. To be more precise, it existed Base fuel I 40% by volume from kerosene and 60% by volume from raw gas oil from Western Canada with a 95% distillation point of 335 ° C, while base fuel II consists of 35% by volume of kerosene and 25% by volume of crude gas oil with a 95% distillation point of 346 ° C and 40% by volume of catalytically cracked gas oil. Everyone these base fuels have been made with a small amount of the flow property improver A or with a small amount of the high molecular weight hydrocarbon fraction or with the latter fraction as well as the flow property improver were added, and the mixtures were subjected to a modified low temperature filterability test carried out as follows became.

A 200 ml sample of the oil was added at a rate of 1.1 ° C./hour. chilled until one Temperature had been reached which was 2.77 ° C below the ASTM Flooding Point of the oil, which is the Was the temperature at which the flow test was performed. This cooling rate of 1.1 ° C./hour. will often found under natural climatic conditions. The oil was then at the test temperature under a vacuum (12 inches of water under atmospheric pressure) through a screened filter filtered. The quality of the oil is measured by the finest sieve through which the 200 ml sample of the oil does not runs for more than 25 seconds. So the finer the sieve through which the oil runs, the better the oil is in terms of its properties at low temperature. The test results are given in the table below.

0.84 mm mesh size 7 *) - 0.025 no passage at

0.84 mm mesh size 8 *) 0.075 - pass through at

0.84 mm mesh size 9 *) - 0.075 no passage at

0.84 mm mesh size 10 *) 0.05 0.025 pass at

0.84 mm mesh size

*) Comparison test.

Example 2

To produce fuel oil mixtures, a middle distillate fuel oil was used that made up 85% by volume cracked distillates with a final boiling point of 349 ° C and 15% by volume of heavy crude oil, the fuel oil having a flocculation point of -11.1 ° C and a pour point of -20.6 ° C. Separate Portions of this fuel oil were made with various concentrations of the amorphous described above solid hydrocarbon fractions were added, which was essentially free of η-paraffins. Different servings of the propellant oil were made with various concentrations of the above-described copolymer Ethylene and vinyl acetate added. Still other portions of the fuel oil were mixed with the solid carbon

Table IV Flow properties amorphous solid coals Finest sieve through which improvers A hydrogen in% by weight the oil in 25 seconds or Results of the filterability test in weight o / o less passes through mixture 0.25 0.59 mm mesh size _ 0.0125 2.0 mm mesh size with base fuel I. 0.0375 0.59 mm mesh size 1") - 0.0375 0.59 mm mesh size 2 ») 0.025 0.0125 0.42 mm mesh size 3 ·) 4) 0.05 - no run at with base fuel II 6 ·)

Flow through the filter Pour point of availability test in% Mixture after ASTM in ° C 100 -23.3 15th -20.6 3 -45.6 30th -17.8 36 -59.4 100 -28.9 100 -28.9 100 -31.7 100 -40.0

Hydrogen fraction as well as with the pour point renifer. Each of the fuel oil mixtures thus obtained was subjected to a low temperature filterability test, with the following results were achieved:

Table V

Effect of the solid amorphous hydrocarbon and the copolymeric pour point depressant on the properties of the fuel oil at low temperature

Copolymer addition

Solid hydrocarbon

0.4% *) none

0.3%) none

none *) 0.02

none *) 0.05

none ·) 0.06

0.4% 0.02

0.3% 0.015

0.2% 0.01

0.1% 0.015

The percentages relate to weight.

*) Comparison test.

The modified low temperature filterability test of Table V was performed as follows: A 200 ml sample of the oil was added at a controlled rate of 1.1 1 ° C / hr. chilled until a temperature of -17.8 ° C had been reached, which was the temperature at which the flow test was carried out was carried out. The oil was then passed through a sieve with a mesh size at the test temperature of 0.42 mm filtered, and the percentage by volume of the oil that had passed through the sieve after 25 seconds, was then measured. When at least 90% of the oil has passed through the strainer in no more than 25 seconds the oil was considered an oil that passed the test.

From the values in the table above it can be seen that the flow properties of the oil are lower Temperature due to the combination of amorphous solid hydrocarbon fraction and ethylene-vinyl acetate copolymer were improved more effectively than by either additive alone. So while to achieve a 100% flow 0.4% by weight of the solid hydrocarbon fraction needed to achieve of a 100% flow only 0.1% by weight of the hydrocarbon is added when 0.015 % By weight of the copolymer was present, and when the copolymer was used alone it was still sufficient not even 4 times the amount of the copolymer to effectively improve the filterability.

Claims (3)

Patent claims: 1. Combustion or fuel mixture with a boiling range of 121 to 371 ⁰ C based on a petroleum middle distillate consisting of a waxy petroleum distillate, 0.01 to 3 wt .-% of a normally solid petroleum hydrocarbon fraction with a melting range of 26.7 to 60 ⁰ C and 0.001 to 1% by weight of a polymeric pour point depressant with an average molecular weight (number average) of 1000 to 50,000, characterized in that it is a solid petroleum hydrocarbon fraction that improves the pour point and the flow rate at low temperature and is a fraction of a petroleum residue oil Amorphous and essentially saturated petroleum fraction obtained with an average molecular weight (number average) of 600 to 3000 and a content of n-paraffinic hydrocarbons of not more than 5% by weight and, as a polymeric pour point depressant, a copolymer of ethylene and vinyl acetate with a content from 3 to 40 mole parts of ethylene per mole part of vinyl contains lacetate 2. fuel or fuel mixture according to claim 1, characterized in that the amount of added Hydrocarbon fraction is 0.1 to 2% by weight. 3. fuel or fuel mixture according to claim 1 or 2, characterized in that the added Hydrocarbon fraction does not contain more than 3% by weight of paraffinic hydrocarbons
4. fuel or fuel mixture according to one of claims 1 to 3, characterized in that there is a Copolymer contains no more than 6 terminal methyl side chains on the polyethylene skeleton per 100 methylene groups on this skeleton
5. fuel or fuel mixture according to one of claims 1 to 4, characterized in that it contains a heating oil as fuel.