EP3399009A1 - Use of compounds showing the efficiency of filterability additives in hydrocarbon distillates, and fuel composition containing same - Google Patents

Abstract

The invention relates to the use in a hydrocarbon distillate having a boiling point of between 150 and 450 ° C. and a starting crystallization temperature measured by Differential Calorimetric Analysis greater than or equal to -5 ° C., preferably from -5 ° C. to + 10 ° C, a homopolymer obtained from an olefinic carboxylic acid ester of 3 to 12 carbon atoms and a fatty alcohol comprising a chain of more than 16 carbon atoms and optionally an olefinic double bond, as a compound for revealing the effectiveness of filterability additives based on copolymers and / or terpolymers of ethylene and vinyl ester of a carboxylic acid of 3 to 12 carbon atoms and a monohydric alcohol comprising from 1 to 10 carbon atoms. The invention also provides an additive composition comprising a conventional hydrocarbon filterability additive in combination with an efficiency developer as well as fuels, fuel and fuel comprising these additive combinations.

Description

The invention relates to the use, in hydrocarbon distillates whose initial crystallization temperature of paraffins is greater than or equal to -5 ° C., of a developer of the effectiveness of conventional hydrocarbon filterability additives with respect to the filterability limit temperature of these distillates and their flow temperature at low temperatures.

The invention also provides an additive composition comprising a conventional hydrocarbon filterability additive in combination with an efficiency developer as well as fuels, fuel and fuel comprising these additive combinations.

For a long time, the oil industry has developed additives that promote the filterability of fuels at low temperatures. These additives, called TLF (Limit Filtration Limit) additives, have the role of limiting the crystal size of the paraffins formed in order to pass the filters arranged inside the internal combustion engines or in the heating installations. This type of additives, widely known to those skilled in the art, is systematically added to conventional middle distillates used as diesel fuels or as heating fuel.

The prior art describes the use of other products having a synergistic effect with the known filterability additives, in particular the ethylene and vinyl acetate and / or vinyl propionate polymers, vis-à-vis improvement of the filterability limit temperature and the low temperature flow temperature of conventional hydrocarbon distillates.

Thus, the patent US 3 275427 discloses a distillate distillation distillate of between 177 and 400 ° C containing an additive consisting of 90 to 10% by weight of an ethylene copolymer comprising from 10 to 30% of vinyl acetate units of molecular weight between 1000 and and 3000 and from 10 to 90% by weight of a lauryl polyacrylate and / or lauryl polymethacrylate of molecular weight by weight ranging from 760 to 100,000. It is noted that these polyacrylates improve the filterability temperature determined according to the NF EN116 standard without damaging the pour point temperature determined by the NF 60105 standard while the ethylene-vinyl acetate copolymer improves the flow.

For the transport of crude oils and heavy distillates by pipeline, the patent US 3726653 have been confronted with the improvement of the flow especially at the low temperatures at which these products could freeze in the pipelines. To improve these properties in paraffin-containing hydrocarbon compositions of which 5 to 20% by weight have a boiling point greater than 350 ° C. and a softening point greater than 35 ° C., the inventors propose adding to these compositions 10 ppm to 2% by weight of a polymer mixture of an olefinic ester of carboxylic acids of 3 to 5 carbon atoms with an alcohol of 14 to 30 carbon atoms and a weight-average molecular weight of 1000 to 1000. 000, with a copolymer of ethylene and vinyl acetate comprising from 1 to 40, preferably from 14 to 24 vinyl acetate units of average molecular weight from 20,000 to 60,000, the molar ratio of olefinic ester polymer to copolymer of ethylene and vinyl acetate ranging from 0.1 to 10: 1.

To control the size of the paraffin crystals present at levels of less than 3% in middle distillates having a boiling point between 120 ° and 480 ° C, the authors of the patent US 4153422 propose to add to these middle distillates from 10 ppm to 1% by weight of a mixture of a homopolymer of an olefinic ester of acrylic or methacrylic acid comprising an alkyl chain of 14 to 16 carbon atoms and a molecular weight of weight ranging from 1000 to 200,000, with a copolymer of ethylene and vinyl acetate with a number average molecular weight of less than 4000. The molar ratio of homopolymer of olefinic ester to ethylene copolymer and vinyl acetate ranging from 0, 1: 1 to 20: 1.

But, with the increasing variety of source of middle distillates, the current middle distillates resulting from the mixing of these sources such as diesel fuels and domestic fuels now have very different compositions from those of the middle distillates previously produced and for which the filterability additives especially those based on copolymers of ethylene and vinyl acetate and / or ethylene and vinyl propionate had been developed. In addition, the evolution of specifications since 2000, and more recently in 2005, has led the refiner to formulate distillates for use as diesel fuels in engines separately, and domestic fuel oils used in heating installations. .

The distillates used are generally derived from more complex refining operations than those resulting from the direct distillation of hydrocarbons and can come from cracking, hydrocracking and catalytic cracking processes and visbreaking processes. With the increasing demand for diesel fuels, the refiner tends to want to introduce cuts that are more difficult to use in these fuels, such as the heaviest cuts resulting from cracking and visbreaking processes which are loaded with heavy paraffins, ie that is, comprising more than 18 carbon atoms. In addition, the synthetic distillates resulting from the transformation of the gas such as those resulting from the Fischer Tropsch process, but also those resulting from the treatment of biomass of plant or animal origin, such as NexBTL and distillates comprising esters of vegetable or animal oils, have appeared on the market and constitute a new range of products that can be used as fuel and base bases. domestic fuel oil also comprising paraffinic chains close to or greater than 18 carbon atoms.

It has been found that the filterability temperature of the distillates obtained by combining the old bases and these new sources is hardly improved by the addition of conventional filterability additive because of the large presence of normal paraffins of more than 18 carbon atoms. and in particular the complex distribution of normal paraffins in their composition. It has been noted in fact in these new combinations of distillates, discontinuous paraffin distributions, making the known filterability additives inadequate. In addition, the arrival of new crude oils on the market much richer in paraffins than those commonly refined and whose filterability temperature of straight-run distillates was hardly improved by conventional filterability additives in the same way as those previously mentioned.

In the documents of the prior art, the authors therefore use combinations of alkylene vinyl ester polymers with vinyl polyesters to resolve mainly problems of pour point improvement, and filterability temperature for distillates of conventional type, and give no indication for solving the specific problems associated with new hydrocarbon distillates whose initial crystallization temperature of paraffins is close to zero and / or whose content of normal paraffins containing more than 18 carbon atoms is greater than 4%.

There is therefore a need to adapt the filterability additives to these new types of distillates.

Thus, this invention applies not only to distillates resulting from the direct distillation of hydrocarbons derived from crude oils which are heavily loaded with paraffins, but also and especially from hydrocarbons obtained from the heaviest cuts of refining operations, that is to say from cracking, hydrocracking and catalytic cracking processes and visbreaking processes or synthetic distillates resulting from gas transformation such as those derived from the Fischer Tropsch process, but also those resulting from the treatment of plant or animal biomass, such as in particular the NexBTL and distillates containing esters of vegetable and / or animal oils, alone or in admixture.

One of the routes chosen by the applicant is that of improving the activity of conventional filterability additives with respect to the temperature limit of filterability of the middle distillates by the addition of another polymer as an agent to reveal the effectiveness of conventional filterability additives present in the middle distillate by producing a synergistic effect.

To this end, the present invention provides the use in a hydrocarbon distillate of boiling point between 150 and 450 ° C and starting crystallization temperature measured by differential scanning calorimetry greater than or equal to -5 ° C preferably -5 ° C to + 10 ° C, a homopolymer obtained from an olefinic carboxylic acid ester of 3 to 12 carbon atoms and a fatty alcohol comprising a chain of more than 16 carbon atoms and optionally a olefinic double bond, as a compound for revealing the effectiveness of filterability additives based on copolymer and / or terpolymer of ethylene and vinyl ester of a carboxylic acid of 3 to 5 carbon atoms and a monohydric alcohol comprising from 1 to 10 carbon atoms.

Preferably, the hydrocarbon distillate comprises a content by weight of n-paraffins containing more than 18 carbon atoms greater than 4%.

Preferably, the hydrocarbon distillate comprises a content by weight greater than or equal to 0.7% of n-paraffins whose carbon number is greater than 24, preferably a mixture of 0.7 to 2% by weight of n-paraffins. having a carbon number ranging from C24 to C40.

According to one embodiment, the filterability additives are copolymers of ethylene containing more than 20% of ester units.

Preferably, the filterability additives are chosen from copolymers of ethylene and vinyl acetate, ethylene and vinyl propionate of ethylene and of vinyl, ethylene and (alkyl) acrylate versatate. ethylene- and (alkyl) methacrylates, taken alone or as a mixture, comprising from 20 to 40% by weight of ester units.

According to a preferred embodiment, the said esters are of the vinyl acetate, vinyl propionate, vinyl versatate, (alkyl) acrylate and (alkyl) methacrylate type, the alkyl group containing from 1 to 7 carbon atoms.

According to one embodiment, the homopolymer is obtained by polymerization of an olefinic ester of acrylic acid optionally substituted with an alkyl group having from 1 to 7 carbon atoms, and an alcohol comprising more than 16 carbon atoms, preferably from 18 to 50 carbon atoms, the homopolymer having a weight average molecular weight Mw of between 5,000 and 20,000, preferably between 10,000 and 19,000.

According to a particular embodiment, the homopolymer is a polyacrylate comprising hydrocarbon side chains of 18 to 40 carbon atoms.

According to one particular embodiment, the distillate is chosen from boiling point distillates of between 150 and 450 ° C., comprising straight-run distillation distillates, vacuum distillates, hydrotreated distillates, distillates obtained from catalytic cracking and / or or the hydrocracking of vacuum distillates, the distillates resulting from conversion processes of the ARDS type (by atmospheric residue desulphurization) and / or visbreaking, the distillates from the recovery of Fischer Tropsch cuts, and the distillates resulting from the conversion BTL of plant and / or animal biomass, and distillates containing alkyl esters of vegetable or animal oils, alone or as a mixture.

1. A) d'un additif de filtrabilité à base de copolymère et/ou terpolymère d'éthylène et d'ester vinylique d'un acide carboxylique de 3 à 5 atomes de carbone et d'un mono alcool comprenant de 1 à 10 atomes de carbone et
2. B) d'un homopolymère d'un ester oléfinique d'acide carboxylique de 3 à 12 atomes de carbone et d'un alcool gras comprenant plus de 16 atomes de carbone

According to another object the invention relates to a composition comprising a mixture consisting of

1. A) a filterability additive based on copolymer and / or terpolymer of ethylene and vinyl ester of a carboxylic acid of 3 to 5 carbon atoms and a monoalcohol comprising 1 to 10 carbon atoms and
2. B) a homopolymer of an olefinic carboxylic acid ester of 3 to 12 carbon atoms and a fatty alcohol having more than 16 carbon atoms

A and B being in a ratio producing a synergistic effect with respect to the TLF filterability temperature measured according to the NF EN116 standard, hydrocarbon distillates having a boiling point of between 150 and 450 ° C. and a measured starting crystallization temperature. Differential Calorimetric Analysis greater than or equal to -5 ° C preferably -5 to + 10 ° C.

According to another object the invention relates to a composition comprising (A) from 85 to 99% by weight of at least one filterability additive based on a copolymer and / or terpolymer of ethylene and a vinyl ester of a carboxylic acid of 3 to 5 carbon atoms and a monohydric alcohol having 1 to 10 carbon atoms; and (B) 1 to 15% by weight of a homopolymer of an olefinic carboxylic acid ester of 3 to 12 carbon atoms and a fatty alcohol comprising more than 16 carbon atoms.

According to a particular embodiment of the composition, the homopolymer has a weight average molecular weight Mw of between 5,000 and 20,000, preferably between 10,000 and 19,000.

Preferably, the homopolymer is an olefinic ester of acrylic acid with an alcohol comprising from 18 to 50 carbon atoms.

Preferably, the homopolymer is a polyacrylate comprising side hydrocarbon chains of 18 to 40 carbon atoms.

Preferably, in the composition according to the invention, the filterability additive is chosen from ethylene copolymers and terpolymers containing more than 20% of ester units, these ester units being themselves chosen from acetate-type esters. vinyl, vinylpropionate, alkylacrylates and alkylmethacrylates taken alone or in a mixture, the alkyl group containing from 1 to 7 carbon atoms.

According to a preferred embodiment, the filterability additives are chosen from copolymers or terpolymers of ethylene and vinyl acetate, and / or vinyl propionate, and / or vinyl versatate, ethylene and / or (alkyl) acrylates, and / or (alkyl) methacrylates, alone or as a mixture, comprising from 20 to 40% by weight of ester units.

According to a preferred embodiment, the filterability additives are chosen from copolymers or terpolymers of ethylene and vinyl acetate, and / or vinyl propionate, and / or vinyl versatate, ethylene and / or (alkyl) acrylates, and / or (alkyl) methacrylates having a weight average molecular weight of from 3,000 to 20,000.

According to a preferred embodiment, the composition according to the invention comprises from 85 to 98% by weight of copolymers of ethylene and of vinyl acetate comprising from 25 to 30% by weight of vinyl acetate units and from 2 to 15% by weight. % by weight of polyacrylate comprising side hydrocarbon chains of 18 to 40 carbon atoms and average molecular weight ranging from 10,000 to 19,000.

According to another object the invention relates to a hydrocarbon distillate comprising from 0 to 5000 ppm of sulfur, and containing from 10 to 5000 ppm of said composition according to the invention, optionally mixed with other detergent dispersant additives, demulsifiers, antifoams, biocides, deodorants, cetane improvers, anti-corrosions, friction modifiers, lubricant, combustion, cloud point, pour point, antisedimentation and conductivity improvers.

Preferably, the distillate comprises at least one hydrocarbon fraction derived from the group consisting of distillates with a boiling temperature of between 150 ° and 450 ° C. and an initial crystallization temperature Tcc greater than or equal to -5 ° C., preferably between 5 ° C and + 10 ° C, including straight-run distillates, vacuum distillates, hydrotreated distillates, distillates from catalytic cracking and / or hydrocracking of vacuum distillates, distillates resulting from conversion processes type ARDS and / or visbreaking, distillates from the recovery of Fischer Tropsch cuts, distillates resulting from the BTL conversion of plant and / or animal biomass, taken alone or in combination, and esters of vegetable and animal oils or their mixtures.

Preferably the distillate comprises an n-paraffin content containing more than 18 carbon atoms greater than 4% by weight.

Preferably the distillate comprises a content greater than or equal to 0.7% by weight of n-paraffins whose carbon number is greater than 24.

Preferably, the distillate comprises from 0.7 to 2% of n-paraffins having a carbon number varying from C24 to C40.

According to another object the invention relates to a diesel fuel comprising from 0 to 500 ppm of sulfur comprising at least one distillate according to the invention.

According to another object the invention relates to a heating oil comprising 0 to 5000 ppm of sulfur comprising at least one distillate according to the invention.

According to another object the invention relates to a heavy fuel oil comprising at least one distillate according to the invention. The invention applies to distillates that can be used as diesel fuel or heating fuel still referred to as domestic fuel oil. These distillates have a starting crystallization temperature or Tcc greater than or equal to -5 ° C, preferably between -5 ° C and + 10 ° C. This temperature Tcc is measured by ACD, this technique making it possible to determine the temperature at which the first paraffin crystals are formed, these generally corresponding to normal paraffins of chain length greater than or equal to 18 carbon atoms, the paraffins being over of 24 carbon atoms being the first to crystallize when the temperature decreases.

The advantage of the present invention lies in the synergistic effect of the use of compounds according to the invention known as "developers" of the effectiveness of conventional filterability additives or TLF with respect to the reduction of the temperature of the filterability of these hydrocarbon distillates refractory to the action of conventional filterability additives used alone.

Thus, the invention is particularly directed to the use of a homopolymer-type developer compound in a hydrocarbon distillate comprising a content by weight of n-paraffins containing more than 18 carbon atoms greater than 4%. More particularly, the hydrocarbon distillate comprises a content by weight greater than or equal to 0.7% of n-paraffins whose carbon number is greater than 24. Preferably, the distillate is a fraction of a boiling point between 150 and 450 ° C, and comprises a mixture of 0.7 to 2% by weight of n-paraffins having a carbon number ranging from C24 to C40.

The filterability additives of the invention are copolymers or terpolymers of ethylene containing more than 20% of ester units. These esters are of the vinyl acetate, vinyl propionate, vinyl versatate, (alkyl) acrylate and (alkyl) methacrylate type, the alkyl group containing from 1 to 7 carbon atoms. The preferred filterability additives are selected from copolymers of ethylene and vinyl acetate, and / or vinyl propionate, and / or vinyl versatate, and / or (alkyl) acrylates, and / or (alkyl) methacrylates, alone or in admixture, comprising from 20 to 40% by weight of ester units. Preferably, the filterability additives used in the invention are copolymers or terpolymers of between 5,000 and 20,000. These copolymers or terpolymers have ester levels of between 20% and 40%.

The additives revealing the effectiveness of the filterability additives according to the invention are homopolymers obtained by polymerization of an olefinic ester of acrylic acid optionally substituted with an alkyl group having from 1 to 7 carbon atoms, and an alcohol comprising more than 16 carbon atoms, preferably from 18 to 50 carbon atoms.

The homopolymer has a weight average molecular weight M w of between 5,000 and 20,000 and preferably between 10,000 and 19,000.

Preferably, the homopolymer is a polyacrylate comprising side hydrocarbon chains of 18 to 40 carbon atoms.

The effectiveness of the developer varies with its weight-average molecular weight, the chain length of the alcohol, and the nature of the carboxylic acid used to synthesize the ester. The homopolymers according to the invention for revealing the effectiveness of conventional TLF filterability additives are selected from a set of polyacrylates useful for improving the pour point of easy-to-treat distillates. However, not all are effective at revealing a synergistic effect with conventional TLF additives.

The distillates targeted by the invention are chosen from distillates having a boiling point of between 150 and 450 ° C. and starting crystallization temperature Tcc of greater than or equal to -5 ° C., preferably of between -5 ° C. and + 10 ° C, including straight-run distillates, vacuum distillates, hydrotreated distillates, distillates from catalytic cracking and / or hydrocracking of vacuum distillates, distillates resulting from ARDS and / or visbreaking, distillates derived from the recovery of Fischer Tropsch slices, and distillates resulting from the BTL conversion of plant and / or animal biomass, and distillates containing alkyl esters of vegetable or animal oils and / or their mixture.

Another subject of the invention is a synergistic composition of additives dedicated to distillates with a boiling point of between 150 ° C. and 450 ° C., with an initial crystallization temperature close to zero, in particular between -5 and + 10 ° C. vs.

This synergistic composition comprises a mixture consisting of a filterability additive and a homopolymer according to the invention in a ratio producing a synergistic effect with respect to the TLF filterability temperature of the distillates according to the invention, TLF measured according to the standard NF EN116.

More particularly, this composition comprises from 85 to 99% by weight of at least one filterability additive based on ethylene copolymer or terpolymer and a vinyl ester of a carboxylic acid of 3 to 5 carbon atoms and a monohydric alcohol having 1 to 10 carbon atoms, and 1 to 15% by weight of a homopolymer of an olefinic ester of carboxylic acid of 3 to 12 carbon atoms and a fatty alcohol comprising more than 16 carbon atoms.

In this composition, the homopolymer has a weight average molecular weight Mw of between 5,000 and 20,000, preferably between 10,000 and 19,000. It is an olefinic ester of acrylic acid with an alcohol comprising from 18 to 50 carbon atoms. Preferably, the homopolymer is a polyacrylate comprising side hydrocarbon chains of 18 to 40 carbon atoms.

The filterability additives adapted to the said composition according to the invention are chosen from ethylene copolymers and terpolymers containing more than 20% of ester units, these ester units being themselves chosen from vinyl acetate type propionate esters. vinyl, (alkyl) acrylates and (alkyl) methacrylates, the alkyl group containing from 1 to 7 carbon atoms. Preferably, these filterability additives are chosen from copolymers or terpolymers of ethylene of vinyl acetate, and / or of vinyl propionate, and / or of vinyl, ethylene and / or (alkyl) versatate. acrylates, and / or (alkyl) methacrylates comprising from 20 to 40% by weight of ester units. These polymers or terpolymers have a weight-average molecular weight of between 3,000 and 20,000.

In a preferred embodiment of the invention, the composition will comprise from 85% to 98% by weight of copolymers of ethylene and vinyl acetate comprising from 25 to 30% by weight vinyl acetate units, and from 2 to 15% by weight. % by weight of polyacrylate comprising side hydrocarbon chains of 18 to 40 carbon atoms and average molecular weight ranging from 10,000 to 19,000.

Another subject of the invention concerns the hydrocarbon distillate whose sulfur content is between 0 and 5000 ppm and which comprises from 10 to 5000 ppm of said composition, optionally mixed with other detergent, dispersant and demulsifier additives, biocides, antifoams, resorbers, cetane improvers, anti-corrosions, friction modifiers, lubricity, combustion, cloud point, pour point, antisedimentation and conductivity improvers.

This distillate according to the invention comprises a major portion of at least one hydrocarbon fraction having a starting crystallization temperature Tcc of greater than or equal to -5 ° C., preferably of between -5 ° C. and + 10 ° C., resulting from the group. consisting of boiling point distillates of between 150 ° C and 450 ° C including straight-run distillates, vacuum distillates, hydrotreated distillates, distillates from catalytic cracking and / or distillate hydrocracking under empty, distillates resulting from conversion processes ARDS and / or visbreaking type, distillates derived from the recovery of Fischer Tropsch slices, distillates resulting from the BTL conversion of plant and / or animal biomass, taken alone or in combination, and esters of vegetable and animal oils or their mixtures. These distillates comprise an n-paraffin content containing more than 18 carbon atoms greater than 4% by weight, and preferably a content greater than or equal to 0.7% by weight of n-paraffins whose carbon number is greater than 24%. .

The distillates which are particularly reactive with the said composition comprise in their chemical composition from 0.7 to 2% of n-paraffins having a carbon number varying from 24 to 40, the n-paraffin distribution being continuous or discontinuous; that is, all n-paraffin families are present or some are absent, thus constituting discontinuities, especially when distillate mixtures are made.

The invention also relates to a fuel, a fuel comprising from 0 to 500 ppm of sulfur and / or a heating oil comprising from 0 to 5000 ppm of sulfur or a heavy fuel oil used as fuel in marine engines and industrial boilers, these products containing a major portion of hydrocarbon base consisting of at least one distillate according to the invention and a corresponding minor portion of 50 to 5000 ppm of a synergistic composition of additives using a developer compound according to the invention. This additive composition may be present in the fuel or fuel with at least one additive of the group consisting of detergent additives, dispersants, demulsifiers, biocides, antifoams, deodorants, cetane improvers, anticorrosions, friction modifiers, lubricant, combustion, cloud point, pour point, antisedimentation and conductivity improvers.

For purposes of illustrating the advantages of the present invention, examples are given without limitation.

EXAMPLE 1

This example describes the nature of the components of the invention and comparative compounds.

The distillates according to the invention which are refractory to filterability additives or TLF (CFPP in English) alone are called Fi and the distillates which are not refractory to these additives are called Gi. They are described in Table I below. <u> TABLE I </ u> G1 G2 F1 F2 F3 % normal paraffins * <C13 4.53 2.86 2.05 1.77 0.41 C13-C17 8.61 7.44 4.58 4.2 4.26 C18-C23 5.47 4.02 4.64 4.31 9.38 > C24 0.66 0.24 0.94 0.8 1.5 TOTAL n-Paraffins 19.27 14.56 12.21 11.08 15.56 TLF (° C) -4 -8 1 0 7 PTE (° C) -12 -15 -6 - 6 PT (° C) -4 -7 2 0 7 Volumic mass .8327 .8414 .8541 0.863 0.870 sulfur ppm 39.8 320 930 1240 1950 Viscosity at 40 ° C mm ² / s 2,725 2,752 2.6348 - - Calculated cetane ASTM D4737 50.1 50.2 44.8 - - Aromatic content IP391 Mono Aromatic% 22.7 23 26.6 27.6 - Di Aromatics% 6.2 5.5 9.1 8.2 - Poly Aromatic% 0.6 1.2 1.9 3.3 - TCC (° C) -7 / -6.2 -8.3 -1.2 -1.2 5 Distillation D86 (° C) Initial Point 167.6 176.8 156.4 162.6 164.1 T10 203 207.6 189.8 195.5 T20 224.7 225.6 203.5 220.7 T50 274.5 270.7 271.9 293.6 T80 317.1 314.1 331.3 341 T90 337.4 333.2 354.3 357 360 T95 353.9 345.9 371.1 372 Period 356 352.2 373.4 382.8 *% by weight of paraffins determined by coupling liquid chromatography / gas chromatography.
PTE = flow temperature
TLF = filterability temperature
PT = cloud point temperature measured by ASTM D2500 or EN 23015.
Tcc = starting crystallization temperature measured by Differential Scanning Calorimetry (DSC or DSC) or according to IP389-93

The TEP or pour point measured for distillates used as fuels is the lowest temperature at which the hydrocarbon can still flow.

PT or cloud point is a visual appreciation of sprouting and crystallization of paraffins, this measurement is less accurate than that of the starting crystallization temperature Tcc.

TLF, the filterability limit temperature of paraffin crystals precipitating in hydrocarbons at low temperature, is intermediate between these two extreme temperatures PTE and Tcc: it is intended to appreciate the temperature at which the size of the crystals is still small enough not to clog the filters.

In general, the respective variations of TLF, PTE and Tcc are not necessarily related to each other and are most often dependent on the chemical composition of the products.

Examples of the F1, F2 and F3 distillates according to the invention have an n-paraffin content greater than or equal to 0.7% and a Tcc of -5 ° C., whereas the distillates G1, G2 have a n paraffins less than 0.7% and Tcc <-5 ° C.

The distribution of paraffins is determined by liquid / gas chromatography. This method makes it possible to determine the n-paraffin concentration of C9 to C30 in the middle distillates.

In a first step liquid chromatography makes it possible to separate the middle distillate according to the chemical families (saturated, mono, di and aromatic tri). The n-paraffins being in the saturated fraction, the latter is recovered and injected onto a column in gas chromatography where the paraffins are separated according to their boiling point and therefore their carbon number. Finally, paraffins are quantified by calibration.

The filterability additives used are copolymers of ethylene and vinyl acetate, hereinafter referred to as EVAi in Table II below. <u> TABLE II </ u> Viscosity at 100 ° C (Pa.S-1) Vinyl acetate level (% by weight) Molecular weight Mw EVA 1 0.3 28 9500 EVA 2 0.4 31 15000 EVA 3 0.4 36 18000 EVA 4 0.3 24 10000

The developers used are bi-labeled polyacrylates whose characteristics are given at 30% of active ingredients in a solvarex-type aromatic solvent (aromatic hydrocarbon fraction of 8 to 20 carbons and boiling point ranging from 140 to 320 ° C.) in Table III below.

As examples of preparation, these polyacrylates are obtained by polymerization under an inert nitrogen atmosphere of the monomer as follows.

100 parts of this monomer is melted beforehand in an oven at 70 ° C. and then solubilized in 158 parts of aromatic solvent (solvarex 10 or solvarex 150). The mixture obtained is introduced continuously for 6:30 and under stirring in a tank under a nitrogen atmosphere containing 75 parts by weight of aromatic solvent and 4 parts by weight of organic peroxide, this mixture having been previously heated to 100 ° C. Throughout the addition, the set temperature is maintained at 100 ° C. The reactor is cooled and the resin stabilized by the addition of 100 ppm of 4-methoxyphenol, in order to avoid a post-polymerization of the residual monomers that can lead to a change in the average molar mass of the polymers during storage. <u> TABLE III </ u> monomer Acid content (mg KOH / g) Density at 20 ° C (kg / l) Visco at 20 ° C (mm / s) Visco at 40 ° C (mm / s) GPC Mw, Mn (dalton) B1 Acrylate C18 / C22 1.5 895 15 5,000 15000 B2 Acrylate C30 / 40 0.5 Not measurable solid Solid 6770

EXAMPLE 2

The present example aims to demonstrate the interest of the developers Bi according to the invention and their influence on the effectiveness of TLF additives on the distillates Fi of the invention and the distillates Gi.

Table IV summarizes the results obtained by comparing the effectiveness of B1 alone or in combination with the TLF EVA1 and EVA2 additives on the Fi and Gi distillates. <u> TABLE IV </ u> Quantity ppm G1 G2 F1 F2 F3 Distillate alone -4 -8 1 0 7 cc -7 -8.3 -1.2 -1.2 5 EVA 1 100 -7 -10 -7 1 7 200 -13 -10 -11 3 7 300 -13 / / 4 7 EVA 2 100 -8 -9 4 3 / 200 -11 -17 3 2 / EVA1 / B1 95.5 / 4.5 100 -8 -9 -11 / / 200 -11 -10 -10 -6 -7 300 -14 / / -8 -10 EVA2 / B1 95.5 / 4.5 100 / -10 / / / 200 / -19 / -6 -10 B1 4.5 -4 -8 1 0 7 9.5 -4 -8 1 1 8

It is observed that distillates Fi of Tcc greater than -5 ° C are little or not reactive to EVAi alone but are reactive to synergistic mixtures EVAi / Bi while distillates out of the invention Gi whose Tcc is less than -5 ° C are only reactive to EVA alone.

It should be noted that the developer B alone also shows no TLF efficiency on any of the Fi or Gi distillate families.

EXAMPLE 3

The present example describes the influence of the relative concentration of Bi developers and TLF EVAi additives on the reduction of TLF temperatures of the typical F 2 distillates.

Table V collates the filterability temperatures of F1 and F2 distillates when the concentration of Bi developer is varied for varying concentrations of EVAi / Bi composition. <u> TABLE V </ u> F 0 ppm 100 ppm 200 ppm F1 EVA1 1 -7 -11 F1 EVA1 / B1: 97.8 / 2.2 1 -13 -11 F1 EVA1 / B1: 95.5 / 4.5 1 -11 -10 F1 EVA1 / B1: 90/10 1 -11 -11 G1 EVA1 -4 -15 -17 G1 EVA1 / B1: 96/4 -4 -15 -17 G1 EVA1 / B1: 92/8 -4 -12 -14 G1 EVA1 / B1: 82/18 -4 -8 -11

The tests carried out by varying the ratio EVA / B1 demonstrate in the case of distillates Fi optimum efficiency for low doses of developer.

By taking Gi distillates, on the contrary, there is a loss of EVAi efficiency with the increase in the concentration of Bi developers, resulting in an increase in the filterability temperature of the distillate.

EXAMPLE 4

The present example describes the preferred polymers of the invention selected from olefinic ester polymers of carboxylic acids and alcohol.

It is a question of describing the impact of the nature of the carboxylic acid and that of the length of chain of the alcohol on the decrease of the filterability temperature of the distillates F1 and F2.

In the composition according to the invention, the content of homopolymers of olefinic ester of carboxylic acids and alcohol is 4.5% for an EVA content of 95.5%.

The content of the composition in the distillates ranges from 0 to 300 ppm in the present example.

The results obtained are summarized in Table VI below, <u> TABLE VI </ u> Monomer used to synthesize developer B Mw (Developer) 0 ppm 200 ppm 300 ppm F2 Without - 1 4 3 F2 B1 Acrylate C18 / 22 13370 1 -6 -6 F2 C18-22 methacrylate 17100 1 3 F2 Stearyl methacrylate-C16 16100 1 4 F2 Lauryl methacrylate-C12 11985 1 3 2 F2 Acrylate C30 / 40 6764 1 0 -7 F2 Stearyl acrylate-C16 13660 1 5 3 F2 Lauryl Acrylate C12 14030 1 3 4 F1 Without - 1 -7 -11 F1 B1 Acrylate C18-22 / Acrylate 2 Ethyl Hexyl: 80/20 7649 1 0 -1 F1 B1 Acrylate C18-22 / Acrylate 2 Ethyl Hexyl: 50/50 7555 1 0 -2 F1 B1 Acrylate C18-22 / Vinyl acetate: 70/30 9701 1 0 -2 F1 B1 C18-22 Acrylate / Isobornyl Acrylate: 70/30 8382 1 0 -1 F1 B1 Acrylate C18-22 8000 1 -11 -10

The effectiveness of the developer compound varies depending on the chain length of the alcohol and the nature of the carboxylic acid used to synthesize the polyester.

In Table VI above, efficiency tests were carried out with developers synthesized by homopolymerization of alkyl acrylates of chain length varying from C12 to C40 (according to the procedure described in Example 1).

These results clearly show that the positive effect of the developer appears for polymers consisting predominantly of alkyl chains greater than C16. The best results are obtained with C18-C22 acrylate and C30-C40 acrylate.

Other tests substituting the developer compound B1 for polymers synthesized by copolymerization of the C18-C22 acrylate with vinyl acetate (ratio: 70/30) or with 2-ethylhexyl acrylate ( ratio 80/20 and 50/50) demonstrate that these copolymers are not effective in comparison with the corresponding C18-C22 homopolymers. They even have a detrimental effect vis-à-vis the temperature of TLF distillates according to the invention.

The nature of the carboxylic acid is also an important parameter, the above-described assays performed substituting B1 with homopolymers of C12 methacrylic acid esters; C16 or C18-C24 show that they are not as effective than their counterparts obtained by homopolymerization of acrylic acid esters.

This example clearly demonstrates that the necessary selection of the polyacrylates of the invention as a developer of the effectiveness of the filterability additives on the filterability temperature of the distillates of the type of the invention is not obvious in view of the prior art. Only the synergistic combination of the composition according to the invention can solve the problem of lowering the TLF temperature of Tcc distillates greater than or equal to -5 ° C.

Claims (6)

Use of distillates in a diesel fuel comprising from 0 to 500 ppm of sulfur, or in a heating oil comprising 0 to 5000 ppm of sulfur, or in a heavy fuel oil,
said distillates being hydrocarbon distillates comprising at least one hydrocarbon fraction derived from the group consisting of boiling point distillates of between 150 and 450 ° C, starting crystallization temperature Tcc measured by differential scanning calorimetry greater than or equal to -5 ° C, preferably from -5 ° C to + 10 ° C, including straight-run distillates, vacuum distillates, hydrotreated distillates, distillates from catalytic cracking and / or hydrocracking of vacuum distillates, distillates resulting from conversion processes of the ARDS and / or visbreaking type, distillates derived from the recovery of Fischer Tropsch cuts, distillates resulting from the BTL conversion of plant and / or animal biomass, taken alone or in combination, and esters of vegetable and animal oils or mixtures thereof, said distillates comprising from 0 to 5000 ppm of sulfur, from 10 to 5000 ppm of a composition comprising (A) from 85 to 99% by weight of at least one filterability additive based on a copolymer and / or terpolymer of ethylene and an ester selected from acetate vinyl propionate, vinyl versatate, (alkyl) acrylate and (alkyl) methacrylate, alone or in admixture, the alkyl group containing from 1 to 7 carbon atoms, and (B) from 1 to 15% by weight of a homopolymer having a weight average molecular weight Mw of between 5,000 and 20,000 and obtained by polymerization of an olefinic ester of acrylic acid and a fatty alcohol comprising more than 16 carbon atoms . Use of a distillate according to claim 1, wherein the homopolymer: has a weight average molecular weight Mw of between 10,000 and 19,000; or is an olefinic ester of acrylic acid with an alcohol comprising from 18 to 50 carbon atoms; or is a polyacrylate comprising side hydrocarbon chains of 18 to 40 carbon atoms. Use of a distillate according to claim 1 or 2, in which the filterability additive is chosen from ethylene copolymers and terpolymers containing more than 20% by weight of ester units, these ester units being themselves chosen among esters of vinyl acetate, vinylpropionate, alkylacrylates and alkylmethacrylates, taken alone or as a mixture, the alkyl group containing from 1 to 7 carbon atoms; or wherein the filterability additives are selected from copolymers or terpolymers of ethylene and vinyl acetate, and / or vinyl propionate, and / or vinyl versatate, ethylene and / or alkyl ) acrylates, and / or (alkyl) methacrylates, taken alone or as a mixture, comprising from 20 to 40% by weight of ester units; or wherein the filterability additives are selected from copolymers or terpolymers of ethylene and vinyl acetate, and / or vinyl propionate, and / or vinyl versatate, ethylene and / or alkyl ) acrylates, and / or (alkyl) methacrylates having a weight average molecular weight of between 3,000 and 20,000. Use of a distillate according to one of claims 1 to 3, comprising from 85 to 98% by weight of copolymers of ethylene and vinyl acetate comprising from 25 to 30% by weight of vinyl acetate units and from 2 to 15% by weight of polyacrylate comprising side hydrocarbon chains of 18 to 40 carbon atoms and weight average molecular weight ranging from 10,000 to 19,000. Use of a distillate according to one of claims 1 to 4, wherein the composition is in admixture with other detergent, dispersant, demulsifier, antifoam, biocide, re-odorant, cetane improvers, anti-corrosions, modifiers friction, lubricity, combustion, cloud point, pour point, antisedimentation and conductivity improvers. Use of a distillate according to one of claims 1 to 5 comprising an n-paraffin content containing more than 18 carbon atoms greater than 4% by weight; or comprising a content greater than or equal to 0.7% by weight of n-paraffins whose carbon number is greater than 24; or comprising from 0.7 to 2% n-paraffins having a carbon number varying from C24 to C40.