EP0961820A1

EP0961820A1 - Additive for fuel oiliness

Info

Publication number: EP0961820A1
Application number: EP98963589A
Authority: EP
Inventors: Danièle Eber; Laurent Germanaud; Paul Maldonado
Original assignee: Elf Antar France
Current assignee: Total Marketing Services SA
Priority date: 1997-12-24
Filing date: 1998-12-22
Publication date: 1999-12-08
Anticipated expiration: 2018-12-22
Also published as: JPH11209766A; HU222537B1; DE69829167D1; CA2281635A1; KR100598227B1; BR9807728B1; EP0961820B1; HUP0001251A2; PT961820E; KR20000071202A; HUP0001251A3; EP1522570A3; AR014163A1; NO994055D0; PL335330A1; ID23178A; NO994055L; FR2772784B1; PL189103B1; FR2772784A1

Abstract

The invention concerns an additive for motive fuel additive, in particular with low sulphur content not more than 500 ppm, consisting for the most part of a combination comprising 5 to 95 wt. % of a glycerol monoester R1-C(O)-O-CH2-CHO-CH2OH or R1-C(O)-O-CH(CH2OH)2, R1 being an alkyl chain containing 8 to 60 carbon atoms, or a monocyclic or polycyclic group comprising 8 to 60 carbon atoms, and from 5 to 95 wt. % of a compound of formula R2-C(O)-X, R2 being an alkyl chain containing 8 to 24 carbon atoms, or a monocyclic or polycyclic group comprising 8 to 60 carbon atoms, and X being selected among (i) the groups OR0, R0 being a hydrocarbon radical comprising 1 to 8 carbon atoms, optionally substituted by one or several esters; and (ii) the groups derived from primary or secondary amines and alkanolamines with aliphatic hydrocarbon chain, comprising 1 to 18 carbon atoms.

Description

ONCTUOSITY ADDITIVE FOR FUEL

The present invention relates to a fuel containing a lubricity additive to improve the lubricating properties of fuels, whether it be land motor fuel (diesel) or aviation fuel (jet fuel), and more particularly low-diesel fuels. sulfur content. It is well known that diesel fuels and aviation fuels must have lubrication capabilities for the protection of pumps, injection systems and all moving parts with which these products come into contact in an internal combustion engine. . With the desire to use increasingly pure and non-polluting products, in particular sulfur-free, the refining industry has been led to improve more and more its treatment processes for removing sulfur compounds. However, it has been observed that by losing the sulfur compounds, the often associated aromatic and polar compounds are also lost, which causes a loss of the lubricating power of these fuels. Thus, below certain levels, the elimination of sulfur compounds in the composition of these products very significantly promotes the phenomena of wear and rupture of moving parts at the level of pumps and injection systems. As the regulations of many countries have imposed a limit on the acceptable upper content of sulfur compounds in fuels to 0.05% by weight in order to reduce the emissions of polluting gases from cars, trucks or buses, in particular in urban agglomerations it is necessary to replace these lubricating compounds by other compounds which are not polluting with regard to the environment but which have sufficient lubricating power to avoid the risks of wear. It is also mentioned in the literature that petroleum fuels with a low sulfur content have a lubricating power which may prove to be insufficient for ensuring good lubrication of the injection systems of new vehicles and can lead to a premature risk of wear. To solve this problem, several types of additives have already been proposed. Thus, anti-wear additives, known for some in the field of lubricants, of the type of fatty acid esters and dimers of unsaturated fatty acids, aliphatic amines, acid esters, have been added to the gas oils. fatty and diethanolamine, and long chain aliphatic monocarboxylic acids as described in US Patents 2,527,889, US 4,185,594, US 4,204,481 and US 4,208,190. Most of these additives have sufficient lubricity but at far too high concentrations, which is very unfavorable economically for the purchase. In addition, additives containing dimeric acids, such as those containing trimeric acids, cannot be used in fuels supplying vehicles in which the fuel may be in contact with the lubricating oil, because these acids form by chemical reaction with detergents commonly used in lubricants, deposits that can accelerate wear processes.

US Patent 4,609,376 recommends the use of anti-wear additives obtained from esters of mono- and poly-carboxylic acids and polyhydric alcohols in fuels containing alcohols in their composition.

In patent GB 2,307,246, the product resulting from the reaction of a carboxylic acid of 10 to 60 carbon atoms chosen from fatty acids or fatty acid dimers with an alkanola ine obtained by condensation of an amine or of a polyamine with an alkylene oxide is preferred as a lubricity additive.

In patent GB 2,307,247, it is preferred to use an acid derivative, substituted by at least one hydroxyl group or an ester of polyols, or alternatively an amide of this acid.

Another chosen route is to introduce vegetable oils or their esters into fuels to improve their lubricating power or their smoothness. Among these are rapeseed, linseed, soybean, sunflower oils or their esters (see patents EP 635,558 and EP 605,857). However, one of the major drawbacks of these esters is their poor lubricity at a concentration of less than 0.5% by weight in fuels.

The present invention aims to solve the problems encountered with the additives proposed by the prior art, that is to say to improve the lubricating power of desulfurized and partially de-flavored fuels, while remaining compatible with the other additives, in particular detergents , and lubricating oils, in particular by not forming deposits and by reducing the cost price in particular by a lower content of additive, clearly less than 0.5%.

The subject of the present invention is the use as a lubricity additive to improve the lubricating power of diesel and aviation fuels with a low sulfur content, that is to say with a sulfur content of less than or equal to 500 ppm, characterized in what the additive is made of:

1) from 5 to 25% by weight of at least one glycerol monoester of formula (I _A ) or (I _B ) below:

R ₁ -C-0-CH ₂ -CHOH-CH ₂ OH (I _A ) il 0

Ri-CO-CH- (CH ₂ OH) ₂ (I _B )

0 with R. chosen from linear or weakly branched, saturated or unsaturated alkyl chains, comprising from 8 to 24 carbon atoms, and cyclic and polycyclic groups comprising from 8 to 60 carbon atoms,

2) from 35 to 75% by weight of a compound of formula (II) below:

in which R is a linear or weakly branched, saturated or unsaturated alkyl chain, comprising from 8 to 24 carbon atoms or a cyclic or polycyclic group comprising from 8 to 60 carbon atoms, and X is chosen from (i) the ORo groups , Ro being a hydrocarbon residue comprising from 1 to 8 carbon atoms, optionally substituted by one or more ester groups, and (ii) the groups deriving primary and / or secondary amines, alkanolamines of aliphatic hydrocarbon chain, linear or branched, comprising from 1 to 18 carbon atoms,

3) and from 5 to 20% by weight of at least one glycerol diester of formulas (III _A ) and / or (III _B ):

R ₃ -CO-CH ₂ -CH0H-CH ₂ -OCR ₄ (III,)

It 1 / ^A

O 0 o R ₃ -C-0-CH ₂ -CH-0-CR ₄ ( ^I II _β ⁾

O CH ₂ OH in which R ₃ and R ₄ , identical or different, are chosen from linear or weakly branched, saturated or unsaturated alkyl chains, comprising from 8 to 24 carbon atoms, and cyclic and polycyclic groups, comprising from 8 to 60 carbon atoms.

Among the glycerol monoesters of formula (I) and the diesters of formula (III) with, respectively, R _χ or, R ₃ and R ₄ consisting of an alkyl chain, the monoesters and di esters obtained from oils are preferred. from the group consisting of lauric oils, from coconut or palm, rich in saturated alkyl chains of 12 to 14 carbon atoms, palmitic oils from palm, lard or tallow, containing a major amount of saturated alkyl chains with 16 carbon atoms, linoleic oils derived from sunflower, corn, or rapeseed, containing a high content of linoleic acid, linolenic oils from flax comprising significant contents in tri-unsaturated alkyl chains containing

1 to 18 carbon atoms, and ricinoleic oils from castor oil.

Among the monoesters and diesters of glycerol obtained from polycyclic acids, the preferred monoesters and diesters include an R- _| _ or, R ₃ and / or R ₄ consisting of at least two rings each formed from 5 to 6 atoms of which at most one is optionally a heteroatom such as nitrogen or oxygen and the others are atoms of carbon, these two rings also having two carbon atoms in common, of preferably vicinal, these said cycles being saturated or unsaturated. They are preferably glycerol monoesters of natural resin acids obtained from the distillation residues of natural oils extracted from resinous trees, in particular from coniferous conifers.

Among these esters of resin acids according to the invention, the esters of abietic acid, dihydroabietic acid, tetrahydroabietic acid, dehydroabietic acid, neoabietic acid, pimaric acid, levopimaric acid are preferred. and parastrinic acid.

By adjusting the operating conditions for partial hydrolysis of these oils, it is possible to directly obtain the mixture of monoalkylesters / glycerol dialkylesters.

According to another embodiment of the invention, it is possible to prepare the alkyl esters of glycerol by esterification reaction between the carboxylic acids previously described and the glycerol.

The esters and amides of formula (II) can be easily obtained by reaction of an alcohol, amino and / or alkanolamine compound with an organic acid such as oleic acid or a simple ester such as methyl oleate by operating under the conditions known per se by a person skilled in the art, esterification and amidification processes.

In a first embodiment, the alcohols used to obtain the compound (II) are chosen from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol or alternatively ethyl 2 hexanol, and / or the oxyalkylated alcohols of formula R (O-CH ₂ -CHR ') _n -OH in which R is an alkyl group of 1 to 6 carbon atoms, R' is hydrogen or an alkyl group of 1 to 4 carbon atoms and n an integer varying from 1 to 5 such as methylcellosolve, butylcellosolve, butyldiglycol and 1-butoxypropanol.

In a second mode, the primary or secondary amines used for obtaining the compound (II) are chosen from the group consisting of methylamine,

Ethylamine, propylamine, butylamine, isobutylamine,

1-ethyl-2-hexylamine, decylamine, dodecylamine, stearylamine and oleylamine, N, N-diethylamine, N, N-dipropylamine, N, N-dibutylamine, N, N-di (ethyl-2-hexyl) amino, methyldecylamine, N-methyldodecylamine, N-methyloleylamine. In a third embodiment, for the tablet

(II) using alkanolamines chosen from amines of

1 to 18 carbon atoms substituted with at least one hydroxylated, hydroxymethylated, hydroxyethylated or hydroxypropylated group such as ethanolamine, diethanolamine, triethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, N-methylethanolamine, tris-

(hydroxymethyl) -aminomethane, (N-hydroxyethyl) - methylimidazoline, (N-hydroxyethyl) -heptadecenylimidazoline.

The additives obtained by physical mixing according to the invention are used to improve the lubricating power of diesel fuels for land engines, optionally in admixture with at least one oxygenated compound chosen from the group formed by alcohols, ethers and esters, as well as with any additive used to improve the quality of the fuel, such as detergent, dispersant, antioxidant and defoamer or even biofuel additives.

A second subject of the invention corresponds to fuels containing between 25 and 2500 ppm, and preferably of

100 to 1000 ppm by weight of at least one additive used according to the invention dispersed in a diesel fuel defined by standard ASTM D-975.

The examples below are given by way of illustration of the invention but without limiting its scope.

EXAMPLE I:

The purpose of this example is to compare the lubricating power of the oiliness additives according to the invention with that of the oiliness additives known with regard to wear under the conditions of the HFRR test (High Frequency Reciprocating Rig) such as described by standard procedure CEC-F06-A96 in article SAE 932692 by JW HADLEY of the University of Liverpool. The additives according to the invention will be referenced X ^ while the comparative additives will be referenced T _j _.

A first additive T- ^ is the product of the reaction of oleic acid with diethanolamine. This reaction is carried out in a 500 ml tetracol flask into which 84.6 g of oleic acid and 105.3 g of xylene are first introduced, then 31.5 g of diethanolamine over a period of 10 minutes. The whole is then kept under reflux of xylene for 6 hours to remove 6.4 ml of water. The final product obtained contains 50% of active material, yellow-orange in color. Analysis by infrared spectroscopy shows absorption bands at 3500 cm-1, at 1730 cm-1 and at 1650 cm-1, corresponding respectively to the hydroxyl, ester and amide functions. The second additive T ₂ is the product of the reaction of a tall oil acid and amino diethanol. The tall oil acid used is a combination of 70% of a mixture of fatty acids (55% oleic acid, 38% linoleic acid, 5% palmitic acid and 2% linolenic acid) and 30 % of resin acids, with an acid number of 185 mg KOH per gram. The procedure is as for T-ι_ by introducing 80 g of tall oil, 28.2 g of diethanolamine and 98.6 g of xylene successively into the flask and maintaining a reflux of xylene for 6 hours. The final reaction product is a clear, viscous yellow-orange liquid with a residual acid number of 0.21 mg KOH per gram.

The third additive T ₃ is a mixture of alkylesters, mono, di and trialkylesters, glycerol comprising mainly glycerol monooleate. The first additive according to the invention X-_ is a physical mixture of 2 g of the additive T ₂ and 1 g of the additive T ₃ .

The second additive according to the invention X ₂ is a physical mixture of 2 g of the additive and 1 g of the additive T ₃ .

The additive T ₄ is the glycerol trioleate sold by the company FLUKA. The third additive according to the invention X is the product of the reaction of the glycerol trioleate T ₄ with diethanolamine. The operation is carried out in a tetracol flask as for T- ^ by mixing 80 g of glycerol trioleate and 18.5 g of diethanolamine, then heating the whole at 150 ° C for 4 hours.

The additive T ₅ is a triglyceride soybean oil with an average molecular weight of approximately 870, composed of 28% oleic acid, 50% linoleic acid, 8% linolenic acid, 3% stearic acid, 10% palmitic acid and 1% arachidic acid.

The fourth additive according to the invention X ₄ is the product of the reaction of 87 g of T ₄ with 21 g of diethanolamine, the mixture being kept under stirring, at 150 ° C, for 6 hours. The additive X ₄ is a fluid, yellow-orange liquid, having in infrared spectrometry the absorption bands characteristic of the alcohol, ester and amide functions.

The fifth additive according to the invention, X ₅ , is obtained under the same conditions as the additive X, but using 87 g of T and 15.75 g of diethanolamine.

The sixth additive according to the invention X ₆ is obtained under the same conditions as the additive X ₄ but using 27 g of the additive T ₅ and 26 g of diethanolamine. The seventh additive according to the invention, X ₇ , is obtained under the same conditions as the additive X ₄ but by replacing the diethanolamine with 24 g of tris- (hydroxymethyl) - aminomethane.

The eighth additive according to the invention XQ is obtained under the same conditions as the additive X4, but using castor oil as a triglyceride, of average molecular weight of approximately 927 composed of 87% ricinoleic acid, 7% oleic acid and 3% stearic acid.

Each of the additives described above is introduced into three different gas oils, A, B and C, the characteristics are given in table I below, at a content of 100 ppm of active material.

TABLE I

The diesel fuel A, B and C thus additivated were subjected to the HFRR test which consists in imposing jointly with a steel ball in contact with a stationary metallic plate, a pressure corresponding to a weight of 200 g and an alternative displacement of 1 mm at a frequency of 50Hz. The moving ball is lubricated by the composition to be tested. The temperature is maintained at 60 ° C. for the entire duration of the test, that is to say 75 minutes. The lubricity is expressed by the average value of the diameters of the wear imprint of the ball on the plate. A small wear diameter indicates good lubricity; conversely, a large wear diameter reflects a power all the more insufficient as the wear diameter is high. TABLE II

It can be seen from this table II, that the physical mixtures according to the invention such as X _χ and X ₂ have lower wear characteristics, therefore much better than those of Ti, T2 and T3, which reflects the synergistic effect. smoothness according to the invention. X3 corresponds to the reaction product obtained according to the process of the invention, diethanolamine on glycerol trioleate. As noted above, the advantage of the additive thus obtained with regard to the wear characteristics obtained by T4.

The performance of additives X4, X5, XQ and X7 must be compared with that of the starting oil T5. As previously, the combination of the reaction products limits the wear phenomena observed in the case of oil alone.

Claims

RF, λ / INnTCATTQNS

1. Use as a lubricity additive for engine, diesel and aviation fuels, with a sulfur content of less than or equal to 500 ppm, characterized in that the additive is composed of:

- from 5 to 25% by weight of at least one glycerol monoester of formulas (I _A ) and / or (I _B ) below:

Ri-CO-CHs-CHOH-CHaOH (I _A )

II o

Ri- -O-CH- (CH ₂ OH) ₂ (I _B ) with R. _j _ chosen from linear or weakly branched, saturated or unsaturated alkyl chains, comprising from 8 to 24 carbon atoms, and cyclic and polycyclic groups comprising from 8 to 60 carbon atoms,

B from 35 to 75% by weight of at least one compound of formula (II) below; R -C-X (II)

II O in which R ₂ is a linear or weakly branched, saturated or unsaturated alkyl chain, comprising from 8 to 24 carbon atoms, and X is chosen from (i) the ORo groups, Ro being a hydrocarbon residue comprising from 1 to 8 carbon atoms, optionally substituted by one or more ester groups, and (ii) groups derived from primary and / or secondary amines, from alkanolamines of aliphatic, linear or branched hydrocarbon chain, comprising from 1 to 18 carbon atoms.

from 0.1 to 20% by weight of at least one glycerol diester of formula (III _A ) and / or (III _B ) R ₃ - C -0- CH ₂ - CH OH- CH ₂ -0- CR ₄ (III A '

11 II

0 0

OR ₃ -C-0-CH ₂ -CH-0-CR ₄ (III _B )

O CH ₂ OH in which R ₃ and R ₄ , which are identical or different, are chosen from linear or weakly branched, saturated or unsaturated alkyl chains, comprising from 8 to 24 carbon atoms, and cyclic and polycyclic groups comprising from 8 to 60 carbon atoms.

Use according to Claim 1, characterized in that the glycerol monoesters of formula (I) and the diesters of formula (III) with, respectively, R-ι_ or, R ₃ and R ₄ consisting of an alkyl chain are chosen from monoesters and diesters obtained from oils from the group consisting of lauric oils, derived from coconut or palm, rich in saturated alkyl chains of 12 to 14 carbon atoms, palmitic oils obtained from palm, lard or tallow, containing a major quantity of saturated alkyl chains with 16 carbon atoms, linoleic oils derived from sunflower, corn, or rapeseed, containing a high content of linoleic acid, linolenic oils from flax comprising significant contents in alkyl chains tri - unsaturated from 1 to 18 carbon atoms, and ricinoleic oils from castor oil.

Use according to either of Claims 1 and 2, characterized in that the glycerol monoesters of formula (I) and the glycerol diesters of formula (III) comprise an R- _| _ or, R ₃ and / or R ₄ consisting of at least two rings each formed from 5 to 6 atoms of which at most one is optionally a heteroatom such as nitrogen or oxygen and the others are atoms of carbon, these two rings also having two carbon atoms in common, preferably vicinal, these said cycles being saturated or unsaturated.

Use according to claim 3 characterized in that the monoesters and diesters of glycerol of formulas (I) and (III) are obtained from natural resin acids contained in the distillation residues of natural oils extracted from resinous trees, in particular of coniferous conifers.

5. Use according to claim 4 characterized in that the esters of resin acids are chosen from the group consisting of esters of abietic acid, dihydroabietic acid, tetrahydroabietic acid, dehydroabietic acid, neoabietic acid , pimaric acid, levopimaric acid and parastrinic acid.

6. Use according to one of claims 1 to 5 characterized in that the esters and amides of formula (II) are obtained by reaction of an alcohol, amino, and / or alkanolamine compound on a carboxylic acid such as oleic acid or also methyl oleate.

7. Use according to claims 6 characterized in that the alcohols are chosen from alkanols from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol or ethyl 2 hexanol, and / or the oxyalkylated alcohols of formula R (0-CH ₂ -CHR ') _n -OH in which R is an alkyl group of 1 to 6 carbon atoms, R' is hydrogen or an alkyl group of 1 to 4 carbon atoms and n an integer varying from 1 to 5 such as methylcellosolve, butylcellosolve, butyldiglycol and 1-butoxypropanol.

8. Use according to claim 6 characterized in that the amines are primary and secondary amines chosen from the group consisting of methylamine, ethylamine, propylamine, butylamine, isobutylamine, ethyl-2- hexylamine, decylamine, dodecylamine, stearylamine and oleylamine, N, N-diethylamine, N, N-dipropylamine, N, N-dibutylamine, N, N-di (ethyl -2) hexylamine, N-methyldecylamine, N-methyldodecylamine, N-methyloleylamine.

9. Use according to claim 6 characterized in that the alkanolamines are chosen from amines comprising from 1 to 18 carbon atoms substituted by at least one hydroxyl, -hydroxymethylated, hydroxyethylated or hydroxypropylated group such as ethanolamine, diethanolamine, triethanolamine, isopropanolamine, diiosopropanolamine, triisopropanolamine, N-methylethanolamine, tris- (hydroxymethyl) -aminomethane, (N-hydroxyethyl) -methylimidazoline, (N-hydroxyethyl) - heptadecenylimidazoline.

10. Fuel for a terrestrial engine with low sulfur content containing from 25 to 2500 ppm and preferably from 100 to 1000 ppm by weight of at least one additive as used in one of claims 1 to 9, the so-called additive being introduced into a diesel fuel defined by standard ASTM D-975.