EP0722481A1

EP0722481A1 - Low temperature operability additive compositions of average distillates

Info

Publication number: EP0722481A1
Application number: EP94928929A
Authority: EP
Inventors: Despina Vassilakis; Robert Leger; Nathalie Cerqueda; Wolfgang Ritter; Thomas Reichert; Stephan Von Tapavicza
Original assignee: Henkel AG and Co KGaA; Elf Antar France
Current assignee: BASF Personal Care and Nutrition GmbH; Elf Antar France
Priority date: 1993-09-30
Filing date: 1994-09-29
Publication date: 1996-07-24
Anticipated expiration: 2014-09-29
Also published as: CZ293805B6; JPH09503015A; FI961425A0; FI961425A; CN1132523A; FR2710652A1; FR2710652B1; ATE167228T1; KR960705004A; PL179141B1; NO961295D0; CZ91896A3; KR100298237B1; UA48117C2; HU220708B1; NO314089B1; DE69411027T2; US5725610A; NO961295L; DE69411027D1

Abstract

PCT No. PCT/FR94/01138 Sec. 371 Date Aug. 13, 1996 Sec. 102(e) Date Aug. 13, 1996 PCT Filed Sep. 29, 1994 PCT Pub. No. WO95/09220 PCT Pub. Date Apr. 6, 1995Additive composition enhancing the low temperature operability of average distillates beyond -20 DEG C. comprising at least 40% by weight of a composition consisting of: i) from 60 to 94% by weight of an antisedimentation additive resulting from the reaction of at least one aliphatic dicarboxylic compound and one polyamine of general formula (II) wherein R is a saturated aliphatic radical comprising from 1 to 32 carbon atoms, n is 2-4 and m is 1-4; and ii) 6-40 % by weight of a dispersing-stabilizing additive having a molecular weight varying from 15000 to 50000 resulting from the esterification reaction of a linear alcohol having from 6 to 24 atoms with an organic acid such as maleic acid and its halides, the ester obtained being polymerized with itself or a copolymerizing compound selected from aliphatic dicarboxylic compounds.

Description

COMPOSITION OF ADDITIVES

OF COLD OPERABILITY OF MEDIUM DISTILLATES

The present invention relates to a new additive composition which improves the cold operability of middle distillates up to temperatures above -20 ° C., and more particularly for diesel fuels and household fuels. This cold operability corresponds to a limit temperature at which middle distillates can be used without clogging problem. It is intermediate between the cloud point temperature (AFNOR NFT 60105 or ASTM D 2500-66) characteristic of the start of paraffin crystallization in the distillate and the pour point of the latter (AFNOR NFT60105) or ASTM D 97-66 ).

It is well known that the crystallization of paraffins is a limiting factor in the use of middle distillates. Also, it is important to prepare diesel fuels adapted to the temperatures at which they will be used in motor vehicles, that is to say to the surrounding climate. Generally, cold operability of fuels at -10 ° C is sufficient in many industrialized countries. But in other countries, such as the Nordic countries, Canada and the countries of North Asia, it is possible to reach fuel temperatures well below -20 ° C. It is the same for domestic fuel stored outside for private homes and buildings. This adequacy of the cold operability of diesel fuels is important, especially when engines are started cold. If the paraffins are crystallized at the bottom of the tank, they can be entrained at start-up in the engine and in particular clog the filters and prefilters placed before the combustion chamber. Similarly for the storage of domestic fuels, paraffins precipitate at the bottom of the tank and can be entrained and obstruct the pipes leading to the boiler. It is obvious that the the presence of solids, such as paraffin crystals, prevents normal circulation of the middle distillate.

To improve their circulation either in the engine or towards the boilers, several types of additives have emerged.

Initially, the petroleum industry focused on the development of additives promoting the filterability of low temperature fuels. These additives, called TLF additives (Filterability Limit Temperature), have the role of limiting the size of the crystals of the paraffins formed. This type of additive, widely known to those skilled in the art, is currently systematically added to middle distillates.

However, these additives, although regulating the size of the paraffinic crystals, cannot prevent the sedimentation of the crystals formed, that is to say their agglomeration, in particular in the tank of stationary diesel vehicles or in the storage tanks. domestic fuel. Also, in a second step, the petroleum industry endeavored to develop anti-sedimentation additives, that is to say dispersants, which keep the paraffinic crystals in suspension in the middle distillate which prevents them from depositing and clump together. The Applicant has in particular developed such an additive described in French patent application FR-A-92 15358 of December 17, 1992.

However, the combined action of TLF additives and anti-sedimentation has not improved the cold operability of all middle distillates produced in refineries for all known crude oils.

This is why the petroleum industry has implemented a third type of additive with a view to lowering the cold operability temperature of middle distillates whatever they are above -20 ° C., even if their temperature cloud point is greater than -20 ° C.

The present invention relates to a new composition of additives for lowering and maintaining the cold operability temperature of middle distillates, even after storage, up to temperatures above -20 ° C. comprising in particular an additive of the third type having the action of maintaining good dispersion of the paraffin crystals in the middle distillate. The subject of the present invention is therefore a composition of additives for lowering the cold operability temperature of the distillates beyond -20 ° C. characterized in that it comprises at least 40% by weight of a combination consisting of : (i) 60% -94% by weight of an anti-sedimentation additive of average molecular weight of about 300 to 10,000 resulting from the reaction

(a) at least one aliphatic dicarboxylic compound chosen from the group consisting of maleic and alkyl maleic anhydrides, alkenyl succinic anhydrides with an alkenyl radical comprising from 10 to 32 carbon atoms, corresponding dicarboxylic acids and light alkyl diesters , (b) and of a polyamine comprising a primary amine function corresponding to the general formula

where R is a saturated aliphatic radical comprising from 1 to 32 carbon atoms, R 'is chosen from the group consisting of the hydrogen atom and saturated aliphatic radicals comprising from 1 to 32 carbon atoms, n is an integer between 2 and 4 and m is an integer between 1 and 4, said reaction occurring after dilution of said dicarboxylic compound and said polyamine in a hydrocarbon solvent with a boiling point between 70 ° C and 250 ° C for a ratio of the molar concentrations of said polyamine to said dicarboxylic compound of between 0.3 and 0.8 and at a temperature between 120 and 200 ° C, for 1 to 8 hours. (ii) 6% -40% by weight of a dispersing-stabilizing additive for paraffin crystals of average molecular weight between 15,000 and 50,000 resulting

(A) at least one step of esterifying a saturated linear alcohol having from 6 to 24 carbon atoms with an organic acid included in the group consisting of acrylic acid and its halides and,

(B) at least one step of polymerization of the ester resulting from the esterification with itself or with at least one copolymerizing compound chosen from dicarboxylic compounds from the group consisting of maleic, alkylmaleic and alkenyl succinic anhydrides, acrylic acid, fumaric acid and the esters of these acids. The polymer thus obtained comprises more than 20% by weight of alkyl chains comprising 12 and 14 carbon atoms, and finally more than 10% by weight and preferably more than 20% by weight of alkyl chains comprising 16 carbon atoms and more. The composition of the present invention improves

1 Cold operability of middle distillates since it allows reaching and maintaining operating temperatures down to -20 ° C without the circulation of the middle distillate being influenced by solidification of paraffin crystals by agglomeration favoring closures.

More specifically, the new composition makes it possible to limit the sedimentation of paraffinic crystals and contributes to maintaining the dispersion of paraffin crystals in middle distillates down to -20 ° C. These advantages result from a completely unexpected synergistic effect observed by the applicant due to the combination of the anti-sedimentation additive (i) with the dispersing-stabilizing additive of paraffin crystals according to the invention (ii). In a first embodiment of the invention, the polyamine chosen to prepare the anti-sedimentation additive corresponds to the following general formula (I) R-NH- [- (CH ₂ ) _n -NH-] _m -H (I)

dar-s la - R island is a saturated aliphatic radical comprising from 12 to 32 carbon atoms, n is an integer between 2 and 4 ^ t m is an integer between 1 and 4.

In a second embodiment of the invention, the polyamine chosen to prepare the anti-sedimentation additive corresponds to the general formula followed by ^~ e (II)

R / ^{N "} [ ^{" (CH2)} n- ^NH -] mH ⁽ II)

R "in which R and R 'are dt ~, linear alkyl radicals, identical or different, comprising from 1 to 24 carbon atoms, n is an integer between 2 and 4, and m is an integer between 1 and 4.

The dicarboxylic compound used to manufacture the anti-food additive is preferably chosen from the group consisting of maleic, alkylmaleic anhydrides, in particular methylmaleic anhydride, and alkenylsuccinic anhydrides obtained by the reaction of at least one olefin comprising from 10 to 32 carbon atoms with maleic anhydride.

As dicarboxylic compound, the n-octadecenylsuccinic and dodecenylsuccinic anhydrides will be preferred. According to the invention, the dispersant-stabilizing additive is obtained from at least two reactions, an esterification reaction followed by a polymerization reaction.

The saturated linear alcohol participating in the esterification reaction for the formation of this additive consists of an alkyl chain comprising from 8 to 22 carbon atoms.

The preferred orσanic acid involved in the reaction '. > esterification -t acrylic acid.

According to the invention, the dispersing-stabilizing additive has an ι ≈r of general formula (III): R ₁ - (- (CT ₂ ) p-Ç -) q- ^R 3 d ")

C = O

I o

R 2.

in which R-- and R are identical or different and correspond to the hydrogen atom or a saturated aliphatic radical comprising from 1 to 30 carbon atoms, R ₃ corresponds to a hydrogen atom or a dicarboxylic compound chosen from the group consisting of maleic, alkylmaleic or alkenylsuccinic anhydrides, acrylic acid and fumaric acid, p is an integer between 1 and 100, and q is an integer between 1 and 10.

In a first preferred embodiment of the invention, the dispersing-stabilizing additive is a polyacrylate of general formula (IV)

H- (CH ₂ -CH-) _σ -H (IV) ι ^q

C = O

I O

IR ₂

in which R is a saturated aliphatic radical, comprising from 8 to 22 carbon atoms, and where q is an integer between 1 and 50. In a second preferred embodiment of the invention, the dispersant-stabilizing additive is a copolymer .

Said copolymer consists for 90 to 99% by weight of at least one alkylated acrylate comprising from 8 to 22 carbon atoms and preferably 8 to 18 carbon atoms per alkylated chain, and from 10 to 1% by weight of at least one copolymerizing compound. In a particular embodiment of the invention, said copolymer consists for 95 to 99% by weight of at least one alkylated acrylate and for 1 to 5% by weight of at least one copolymerizing compound. Said copolymerizing compound is a dicarboxylic compound chosen from the group consisting of maleic, alkylmaleic and alkenylsuccinic anhydrides, and fumaric acid. The preferred copolymerizing compounds are random anhydride and fumaric acid.

The new composition according to the present invention advantageously comprises a filterability additive. In this case, it consists for 40 to 70% by weight of the combination of at least one anti-sedimentation additive and at least one dispersant-stabilizing additive according to the invention and for 30 to 60% by weight of at least one filterability additive. Preferably, it comprises from 65 to 50% by weight of said combination and from 35 to 50% by weight of the filterability additive. The preferred filterability additive is chosen from the group consisting of ethylene-vinyl acetate (EVA) copolymers and ethylene-vinyl propionate (EVP) copolymers.

Another subject of the invention is a composition of medium crude oil distillate comprising a major proportion of medium crude oil distillate and a minor proportion of said composition of additives first object of

1 invention.

In said middle distillate composition, said middle distillate is a hydrocarbon fraction distilled between 150 and 450 ° C, and preferably a diesel fraction distilled between 190 and 350 ° C.

In the preferred mode of the distillate composition, the minor proportion of said composition of additives which is the first object of the invention is between 0.01 and 0.20% by weight of said middle distillate composition.

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

EXAMPLE 1 The present example aims to emphasize the unexpected synergistic effect of the dispersant-stabilizing additive and the anti-sedimentation additive in the presence of a filterability additive type TLF. To this end, samples of diesel were prepared from a diesel as defined below and in Table I.

% paraffin. : 11.84% density at 15 ° C: 0.836

TABLE I

ASTM D86 distillation (° C)

P.l 159

5% 184

10% 191

20% 204

30% 219

40% 235

50% 254

60% 275

70% 297

80% 318

90% 340

95% 355

P.F. 363

P.l. : starting point P.F.: ending point

These gas oils contain different combinations of additives as described in Table II below:

TABLE II

FUEL ADDITIVE COMPOSITION

1 - 0.06% filterability additive (TLF) in diesel

2 - 0.06% composition of additives in diesel * 40% filterability additives (TLF) * 60% anti-sedimentation additive

3 - 0.06% composition of additives in diesel * 40% filterability additive (TLF) * 60% dispersant-stabilizing additive

4 - 0.06% additive composition

* 40% filterability additive (TLF)

* 36% anti-sedimentation additive

* 24% dispersing-stabilizing additive filterability additive: K5486 marketed by BASF anti-sedimentation additive: CP9555 marketed by Elf Antar France dispersing-stabilizing additive according to the invention. These four additive diesel oils are packaged in four 250 cm3 test tubes.

These test tubes are sealed hermetically, then left to stand in a cold room at (-20 ° C) for 24 hours. After 24 hours, the homogeneity of the diesel fuel additive is evaluated by the number of phases observed in each test tube and their quality, then the cloud point temperature of the upper and lower phases is measured.

The quality of the upper phase is decisive with regard to the anti-sedimentation efficiency of the additive composition. When the upper phase is cloudy, a large proportion of paraffins have remained in suspension. When this phase is clear, almost all paraffins sedimented, that is to say has agglomerated in the bottom of ^• 1 specimen.

The quantitative results obtained from

% volume of these different phases and the cloud point temperature difference between the upper phase and the lower phase in the test piece are collated in Table III below:

TABLE III

Test tube Number Phase Phase Phase Clear phase Deviation of sediment slightly or clearly cloudy phase temperature% vol. % flight. % vol. cloud point ° C

% flight.

1 2 22 78 -19

2 2 9 91 -13

3 2 23 77 -21

4 2 4 96 -4

It can be seen that when an anti-sedimentation additive is added to the diesel fuel already added to the TLF (samples 1 and 2), the homogeneity of the diesel fuel is improved, which does not result in a reduction in the cloud point difference between the upper phase and the lower phase in the test tube. When the dispersant-stabilizing additive according to the invention is added to the sole filterability additive (TLF) in the diesel fuel, the homogeneity of the diesel fuel is not improved and the cloud point differences between the lower and upper phases remain the same (samples 1 and 3).

On the other hand, the combination of the anti-sedimentation additive and the dispersing-stabilizing additive with the TLF additive greatly improves the homogeneity of the diesel fuel and limits the difference in cloud points between the upper and lower phases (samples 1, 2 and 4).

This underlines the superiority of the invention mainly due to the synergistic effect between the anti-sedimentation additive and the dispersing-stabilizing additive.

EXAMPLE II

The present example aims to show the universality of the combination of additives according to the invention with a view to lowering the cold operability of middle distillates beyond -20 ° C., whatever their origin.

For the purposes of this example, three gas oils A, B and C additivated by combinations according to the invention are tested as described in Example I. These are characterized by their paraffinic distribution, that is to say by their concentration in paraffins comprising less than 13 carbon atoms (<C ₁₃ ), in paraffins comprising from 13 to 18 carbon atoms (Cι ₃ -Cι ₈ ) and in paraffins comprising from 19 to 23 carbon atoms (C- _| gC ₂₃ ) . This distribution is characteristic of the behavior of diesel fuel when cold, whatever its source.

The paraffin distributions for these three gas oils are given in Table IV below:

TABLE IV

Diesel% paraffins% paraffins% paraffins% paraffins in diesel <C13 C13-C18 C19-23

A 10.1 4.95 71.29 23.76

B 10.0 17 74 9

C 11, 84 20.87 50.22 18.91 0.06% by weight of an appropriate composition of additives according to the invention is added to each of these three gas oils, these compositions being described in Table V below:

TABLE V

Composition% additive *% anti additive *% additive *

Diesel fuel sedimentation stabilizing dispersant

A 40 36 24

B 25 65 10

C 35 55 10

* These additives are described in Example I.

The results of the cold resistance test as described in Example I are given for these three additive gas oils, according to the invention, in Table VI below, in comparison with these same three additive gas oils by 0.025% by weight. the only filterability additive (TLF):

TABLE VI

No. Phase Phase Phase Deviation from

Diesel fuel sedimented phases clear cloudy or temperature

% flight. % flight. clear of% vol point. trouble

A + TLF 2 12 88 -22

Additive * 2 18 82 -7

B + TLF 2 20 80 -20.1

B additive * 2 2 98 -3

C + TLF 2 24 76 -21, 8

C additive * 2 4 96 -4

additive *: according to the invention. It can be seen that, whatever the paraffinic distribution of these gas oils, the compositions according to the invention promote cold operability at -20 ° C., characterized by obtaining two phases, a sedimented phase and a cloudy phase, and a difference temperature between the trouble points of the cloudy upper phase and the sedimented lower phase between 0 and 10 in absolute value.

Claims

1 - Composition of additives improving the cold operability of middle distillates beyond -20 ° C, characterized in that it comprises at least 40% by weight of a combination consisting of: (i) 60% to 94% by weight of an anti-sedimentation additive of average molecular weight of about 300 to

10,000 resulting from the reaction

10

(a) at least one aliphatic dicarboxylic compound chosen from the group consisting of maleic and alkylmaleic anhydrides, alkenylsuccinic anhydrides with an alkenyl radical comprising

15 of 10 to 32 carbon atoms, the dicarboxylic acids and the corresponding light alkyl diesters,

(b) and a polyamine comprising an amino function

20 primary corresponding to the general formula

R

^ N - [- (CH ₂ ) _n -NH-] _m -H

R 'where R is a saturated aliphatic radical comprising from 1' 25 to 32 carbon atoms, R 'is chosen from the group consisting of the hydrogen atom and saturated aliphatic radicals comprising from 1 to 32 carbon atoms, n is an integer between 2 and 4 and m is an integer between 1 and 4,

Said reaction occurring after dilution of said dicarboxylic compound and of said polyamine in a hydrocarbon solvent with a boiling point of between 70 ° C. and 250 ° C. for a ratio of the molar concentrations of said polyamine to said compound

35 dicarboxylic between 0.3 and 0.8 and at a temperature between 120 and 200 ° C. (ii) 6% to 40% by weight of a dispersant-stabilizing additive of average molecular weight between 15,000 and 50,000 resulting (A) at least one step of esterifying a saturated linear alcohol comprising from 6 to 24 carbon atoms with an organic acid included in the group consisting of acrylic acid and its halides,

(B) and, at least one step of polymerizing the ester obtained in the step of prior esterification with itself or with a copolymerizing compound chosen from dicarboxylic compounds from the group consisting of maleic, alkylmaleic anhydrides and alkenyl succinics, acrylic acid, fumaric acid and the esters of these acids,

the polymer thus obtained comprising more than 20% by weight of alkyl chains comprising 12 and 14 carbon atoms, and finally more than 10% by weight and preferably more than 20% by weight of alkyl chains comprising 16 carbon atoms and more.

2 - Composition according to claim 1 characterized in that the polyamine chosen to prepare said anti-feeding additive corresponding to the general formula R-NH - [- (CH ₂ ) _n -NH-] _m -H (I) in which R is a saturated aliphatic radical comprising from 12 to 32 carbon atoms, n is an integer between 2 and 4 and m is an integer between 1 and 4.

3 - Composition according to claim 1 characterized in that the polyamine chosen to prepare said anti-sedimentation additive corresponds to the general formula

in which R and R 'are identical or different linear alkyl radicals comprising from 1 to 24 carbon atoms, n is an integer between 2 and 4, and m is an integer between 1 and 4. - Composition according to one of claims 1 to 3 characterized in that the dicarboxylic compound chosen to prepare said anti-sedimentation additive is chosen from the group consisting of maleic, alkylmaleic anhydrides, in particular methylmaleic anhydride, and alkenylsuccinic anhydrides obtained by reaction of at least one olefin comprising from 10 to 32 carbon atoms with maleic anhydride.

- Composition according to claim 4 characterized in that the preferred dicarboxylic compounds are n-octadecenylsuccinic anhydride and dodecenylsuccinic anhydride.

- Composition according to one of claims 1 to 5 characterized in that the saturated linear alcohol participating in the esterification reaction consists of an alkyl chain comprising from 8 to 22 carbon atoms.

- Composition according to one of claims 1 to 6 characterized in that the organic acid involved in said reaction (A) of esterification is acrylic acid.

- Composition according to one of claims 1 to 6 characterized in that the dispersing-stabilizing additive is a polymer of general formula

in which R- _^ and R ₂ are identical or different and correspond to a hydrogen atom or a saturated aliphatic radical, comprising from 1 to 30 carbon atoms, R ₃ corresponds to a hydrogen atom or a dicarboxylic compound chosen from the group consisting of maleic, alkylmaleic and alkenylsuccinic anhydrides, acrylic acid and acid fumaric, p is an integer between 1 and 100 and q is an integer between 1 and 10.

- Composition according to one of claims 1 to 8 characterized in that the dispersing-stabilizing additive is a polyalkylacrylate of general formula

H - (CH ₂ -CH-) _g -H

C = O (IV) O i R ₂ in which R ₂ is a saturated aliphatic radical, comprising from 8 to 22 carbon atoms, and where q is an integer between 1 and 50.

10- Composition according to one of claims 1 to 7 characterized in that the dispersing-stabilizing additive is a copolymer.

11- Composition according to one of claims 1 to 7 and 10 characterized in that the copolymer consists for 90 to 99% by weight of at least one alkylated acrylate comprising from 8 to 22 carbon atoms per alkylated chain, and from 10 at 1% by weight of at least one copolymerizing compound.

12- Composition according to claim 10 characterized in that the copolymer consists for 95 to 99% of at least one alkylated acrylate comprising from 8 to 22 carbon atoms per alkylated chain and for 1 to 5% of at least one compound copolymerizer chosen from dicarboxylic compounds from the group consisting of maleic, alkylmaleic and alkenylsuccinic anhydrides, and fumaric acid.

13- Composition according to claim 10 characterized in that the alkylated acrylate units comprise from 8 to 18 carbon atoms per alkylated chain. 14- Composition according to claim 10 characterized in that the preferred copolymerizing compounds are maleic anhydride and fumaric acid.

15- Composition according to one of claims from 1 to 14 characterized in that it comprises from 40 to 70% by weight of said combination of an anti-sedimentation additive and a dispersant-stabilizing additive, and from 30 to 60% by weight of a filterability additive.

16- Composition according to claim 15 characterized in that it comprises from 65 to 50% by weight of said combination and from 35 to 50% by weight of the filterability additive.

17- Composition according to one of claims 15 and 16, characterized in that the filterability additive is chosen from the group consisting of ethylene-vinyl acetate copolymers (EVA) and ethylene-vinyl propionate copolymers (EVP) .

18- Composition of crude petroleum distillate comprising a major proportion of petroleum distillate and a minor proportion of an additive composition according to one of claims 1 to 17.

19- A medium petroleum distillate composition according to claim 18 characterized in that said medium distillate is a hydrocarbon fraction distilling between 150 and 450 ° C and preferably a diesel fraction distilling in a temperature range between 190 and 350 ° C.

20- Composition of petroleum middle distillate according to one of claims 18 and 19 characterized in that the minor proportion of said composition of additives corresponds to 0.01 to 0.20% by weight of said composition of middle distillate.