NL8302012A - COPOLYMERS WITH NITROGEN FUNCTIONS PARTICULARLY SUITABLE AS ADDITIVES FOR REDUCING THE CLOUD OF MIDDLE DISTILLATES OF HYDROCARBONS AND COMPOSITIONS OF MIDDLE DISTILLATES OF HYDROCARBONS CONTAINING THESE COPOLYMERS. - Google Patents

Description

. ^^ 833065 / vdV / cd -1-. * r

Title: Nitrogen-functional copolymers particularly useful as additives for lowering the cloud point of hydrocarbon middle distillates and hydrocarbon middle distillates containing these copolymers.

The invention relates to new nitrogenous additives which are suitable as agents for lowering the cloud point of middle distillates of hydrocarbons (fuel oils, gas oils) and to the compositions of the middle distillates containing these additives. The petroleum distillates encompassed by the invention consist of middle distillates (fuel oil gas oils) whose distillation range standard ASTM D 86-67) is between 150 ° C and 450 ° C. The more specifically intended gas oils have a distillation range ranging from an initial temperature between 160 ° C and 190 ° C to a final temperature between 350 ° C and 390 ° C.

There are many commercially recommended products for improving the filterability limit and the pour point of a petroleum fraction rich in paraffin-15 finen, such as, for example: - the long chain olefin based polymers? - the copolymers based on alpha-olefins; - the ethylene-vinyl acetate copolymers; - the N-acylaminoethyl esters of polymers containing acids? Or - halogenated hydrocarbon compounds.

These products act on the kinetic crystallization phenomena and change the size of the crystals, so that the suspension can be used at a much lower temperature without clogging the pipes and the filters. The above-mentioned products do not change the temperature at which the first paraffin crystals appear. So far n.1. this temperature was assumed to be a given depending on the molecular weight and the formula of the paraffins and on the nature of the solvent.

The lowering of the cloud point of the middle distillates (especially gas oils) by an additive would be of particular interest to the refiner 8302012 m -2 since it would allow satisfying without altering the distillation schedule to the specifications currently developing towards greater hardness.

It has now been found that certain chemical compounds, which are defined below, that when added to middle distillates, they have the property of first showing the first paraffin crystals at a much lower temperature than that at which these crystals would appear. in the absence of such additives. This property is all the more unexpected since it is retained after multiple reheating and re-cooling cycles and is manifested by an unresolved mechanism.

This class of chemical compounds also has an effect on other properties of middle distillates (especially of gas oils) by altering the behavior of the medium containing the precipitated paraffins.

The compounds recommended according to the invention therefore have an important effect on the filterability limit temperature and the flow temperature.

When the paraffin crystals whose formation is caused by cooling have appeared, they have a natural tendency to collect by gravity in the lower portion. This phenomenon, generally known under the name of sedimentation, causes clogging of the pipes and of the filters and is not permissible for the good use of middle distillates and in particular of gas oils.

In particular, the chemical compounds recommended according to the invention can significantly reduce the sedimentation rate of the paraffins formed by cooling of gas oils and other middle distillates.

Finally, the products recommended for their abovementioned properties provide gas oils and other middle distillates to which they are added have anti-corrosion properties on the metal surfaces.

Generally, the additives of the present invention consist of polymer products having an average number molecular weight of about 1000 to 10,000, from the condensation of a compound with primary amine functions, 40 which will be described below, with a copolymer formed 8302012 -3- * between: (A) vinyl acetate and (B) at least one unsaturated a, 3-dicarboxylic acid compound which may be a dicarboxylic acid, a diester of such an acid or an anhydride.

The proportions in the copolymer of the units corresponding to the monomers (A) and (B) are preferably in the range of 50% -50%, the units corresponding to the monomers (A) and (B) then being in the copolymer alternating 1Q.

The unsaturated α, β-dicarboxylic acid compounds (B) which fall in the composition of the copolymers encompassed by the invention can be selected from malexic acid, the alkyl maleic acids (in particular methyl maleic acid or citraconic acid), the alkyl diesters of these acids (in the especially the methyl diesters, ethyl diesters or propyl diesters) and the corresponding anhydrides. Within the scope of the invention preference is given to anhydrides and more particularly to maleic anhydride.

The primary amine function compound that condenses with the above-described copolymers to form the additives of the invention may correspond to one of the two general formulas 1 and 2 of the formula sheet.

In formula 1, R represents a monovalent saturated aliphatic group having 3-30 carbon atoms, while Z, depending on the cases, may be an oxygen atom or a divalent -NH- or -NR * group, where R 'is a monovalent , preferably straight, aliphatic group having from 1 to 30 carbon atoms and preferably from 12 to 24 carbon atoms; n may be an integer of 2-4 and m may be zero if Z is -NH-, or an integer of 1-4 in all cases.

The above-mentioned compounds of formula 1 may consist of primary amines of formula R-N 2 (in this case Z represents the -NH group, while the value of m is zero). Preferably, the group R is straight and contains 12-24 carbon atoms. Dedecylamine, tetradecylamine, hexadecylamine, octadecylamine, eicosylamine and docosylamine may be mentioned as specific examples of these amines.

The compounds of formula 1 may also consist of 4Q polyamines derived from saturated aliphatic amines containing 8302012

* 'V

-4- \ answer to. the formula 3 of the formula sheet, corresponding to the formula 1 wherein Z represents the -NH group, m- may have a value of 1-4 and n a value of 2-4, preferably 3. Preferably the group is R straight and includes 5 12-24 carbon atoms. As specific compounds can be mentioned: 1,3-N-dodecyldiaminopropane, 1,3-N-tetradecyl diaminopropane, 1,3-N-hexadecyldiaminopropane, 1,3-N-octadecyl diaminopropane, 1,3-N-eicosyldiaminopropane 1,3-N -docosyl-diaminopropane. N-hexadecyldipropylene triamine, N-octadecyΙ-ΙΟ dipropylene triamine, N-eicosyl dipropylene triamine and N -docosyl dipropylene triamine.

The compounds of the formula may also consist of polyamines corresponding to the formula 4 of the formula sheet, corresponding to the general formula wherein z represents -NR'- and wherein R and R ', which are identical or different, are each an alkyl group with 1-24 carbon atoms and preferably 8-24 carbon atoms, R and R 'collectively preferably contain 16-32 carbon atoms; n has a value of 2-4 and m has a value of 1-4. As specific compounds 20 may be mentioned: 1,2-N, N-diethyldiaminoethane, 1,2-Ν, Ν-diisopropyldiaminoethane, 1,2-N, N-dibutyl diaminoethane, 1,4-N, N-diethyldiamino-butane, 1, 3-N, N-dimethyldiaminopropane, 1.3-N, N-diethyldiaminopropane, 1,3-N, N-dioctyldiaminopropane, 1,3-N, N-didecyldiaminopropane, 1,3-N, N-didodecyldiaminopropane, 1,3-N , N-ditetradecyldiaminopropane, 1,3-N, N-dihexadecyldiaminopropane, 1,3-N, Nd ± octadecyldiaminopropane, N, N-didodecyl dipropylene triamine, N, N-ditetradecyldipropylene triamine, Ν, Ν-dihexadecyldipropylenetylene -dioctadecylipipropylenediamine.

Finally, the compounds of formula 1 encompassed by the invention may consist of amine ethers which more particularly correspond to formula 5, which corresponds to the general formula, wherein Z represents an oxygen atom; preferably the group R contains 12-24 carbon atoms, and m 35 is an integer of 1-4 and n is an integer of 2-4, preferably 2 or 3.

Among the ether amines, specific compounds can be mentioned: 2-methoxyethyl amine, 3-methoxypropyl amine, 4-methoxybutyl amine, 3-ethoxypropyl amine, 3-octyloxypropyl amine, 3-decyloxypropyl-8302012-5-amine, 3-hexadecyloxypropylamine, 3-eicosyl , 3-docosyloxypropylamine, 1,3-N- (3-octyloxypropyl) diaminopropane, 1,3-N- (3-decyloxypropyl) diaminopropane, .3- (2,4,6-trimethyldecyl) oxypropylamine and 1 3-N- / 3- (2,4,6-trimethyldecyl) 5 oxypropy1 / diaminopropane.

The primary amine function compound used in the preparation of the additives according to the invention may also consist of an amino alcohol of the general formula 2 of the formula sheet in which RH is a straight or branched, preferably straight, divalent, saturated aliphatic group having 1 -18 carbon atoms.

As specific examples can be mentioned: monoethanolamine, 1-amino-3-propanol, 1-amino-4-butanol, 1-amino-5-pentanol, 1-amino-6-hexanol, 1-amino-7-heptanol, 15 1-amino-8-octanol, 1-amino-10-decanol, 1-amino-11-undecanol, 1-amino-13-tridecanol, 1-amino-14-tetradecanol, 1-amino-16-hexadecanol, 2- amino-2-methyl-1-propanol, 2-amino-1-butanol, and 2-amino-1-pentanol.

It goes without saying that, without departing from the scope of the invention, one or more compounds corresponding to the formula 1 and / or one or more compounds corresponding to the formula 2 may also be used.

The preparation of the additives according to the invention generally comprises two steps: the preparation of the α, β-

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Dicarboxylic acid vinyl acetate monomers followed by condensation of the polymer formed with at least one compound of formula lof 2.

The preparation of the base copolymers is carried out in the first step according to the known processes for the polymerization using radicals, for example in the presence of an initiator of the azobisisobutyronitrile or peroxide type (such as lauroyl peroxide) dissolved in a hydrocarbon solvent, such as for example cyclohexane, iso-octane, dodecane, benzene, toluene, xylene, diisopropylbenzene or also tetrahydrofuran or dioxane. Advantageously, hydrocarbon fractions with a relatively high boiling point, such as a kerosene or a gas oil, are used.

The amount of solvent used will generally be such that the dry matter weight concentration is between 25 and 70% and preferably at about 50%.

8302012 Φ 'v -6-

The copolymerization reaction, in the presence of a radical initiator, is carried out at a temperature of 40-100 ° C and preferably 50-70 ° C. Depending on the working conditions, the reaction time can be between 2 to 10 hours, usually between 3 and 5 hours. A solution of the copolymer is obtained in the form of a viscous liquid.

For the preparation of the additives according to the invention, the condensation of the compound of formula 1 or 2 with the copolymer formed in the first stage is carried out in the second stage by any conventional method.

To the solution of the copolymer obtained in the manner described above, the compound of formula I and / or 2 is generally added in a molar amount substantially corresponding to the amount of unsaturated diacid used in the preparation of the copolymer, unsaturated diester or unsaturated anhydride. This amount can be, for example, 0.9 to 1.1 moles of the compound of formula 1 or formula 2 per mole of dicarboxylic acid compound. One can also have a more important undersize. use compound of formula 1 or formula 2Q 2. It is also possible to use such a small amount that for example 0.5 mol / mol dicarboxylic acid compound is included in the copolymer.

The reaction is carried out by heating the mixture to a temperature between 75 and 130 ° C, preferably between 80 and 100 ° C, the duration of the reaction being between about 1 and 6 hours, with a reaction time of about 2 hours in general is sufficient. The reaction of the compounds of formula I or 2 with the units B of the copolymer gives rise to the formation of imide groups (succinimides), this reaction being accompanied by the formation of water or alcohol depending on the nature of the dicarboxylic acid units (B) (diacid anhydride or diester). If desired, the volatiles formed may be removed from the reaction mixture either by entraining with an inert gas such as, for example, nitrogen or argon, or by azeotropic distillation with the selected solvent.

Another particular embodiment of the synthesis of the adjuvants of the invention, in some cases, consists of the radical copolymerization of vinyl acetate 4q and of N-substituted maleimides, the latter being obtained by preliminary reaction of 8302012 -7- φ · *. the compounds of formula 1 or 21 with the maleic anhydride or one of its aforementioned compounds.

The additives are obtained as a solution in the selected solvent and can be used directly in this form in the middle distillates of petroleum (especially gas oils) whose cloud point is desired to be improved.

Although the mechanism of action of these additives on the appearance temperature of the paraffin crystals in the IQ middle distillates has not yet been fully elucidated, a marked improvement in the cloud point of the middle distillates treated with these additives is observed when added in concentrations of, for example, 0.001 to 1 wt% and preferably 0.01 to 0.2 wt%. For example, the cloud point drop may reach 4 ° c or more. It is remarkably observable that the additives included in the invention, which are effective for improving the cloud point of the middle distillates, on the other hand, have the property of inhibiting the sedimentation of n-paraffins in still middle distillates, the filterability temperature / Improve the flow temperature and inhibit the corrosion of the metal surfaces in contact with these distillates.

The following examples illustrate the invention without limiting it:

Example I.

25 a / 43 g (0.5 mol) of vinyl acetate, 49 g (0.5 mol) of maleic anhydride, 350 ml of toluene and 2 are placed in a thermostatically controlled, double-walled reactor, of 1 liter with an effective mechanical stirring system. .8 g azobisisobutyronitrile.

The stirred mixture is kept at 70 ° C for 6 hours, the resulting copolymer is filtered off, washed with toluene and then dried in vacuo at 80 ° C.

b / To 18.4 g of the copolymer thus obtained, 14 g (ie 0.05 mole equivalent of primary amine) of a commercial mixture of fatty amines with about 1% amine with 14 carbon atoms, 28% amine with 16 carbon atoms and 71% are added amines with 18 carbon atoms. Heptane is added such that the dry matter percentage is about 60%, 8302012 if> J. 6-8, then refluxed for 3 hours.

In this way additive I is dissolved in heptane and the concentration of final product is adjusted to 50% by weight.

Additive II is prepared under conditions identical to those described under b of Example I, starting from 9.2 g of the copolymer prepared according to 1-a and 8.1 g (ie 0.027 mol equivalent of primary amine) of a mixture of primary amines with fat chains containing about 1% amine with 14 carbon atoms, 5% amines with 16 carbon atoms, 42% amines with 18 carbon atoms, 12% amines with 20 carbon atoms and 40% amines with 22 carbon atoms.

Example III.

Additive III is obtained under similar conditions as described under b / of Example I by condensation of 16.96 g, ie 0.053 mol equivalent of primary amine, of a mixture of fatty amines having 5% amine with 16 carbon atoms, 15% amine with 18 carbon atoms, 40% amine with 20 carbon atoms and 40% amine with 22 carbon atoms, 20 with 18.4 g of the copolymer obtained according to 1-a. Examples IV to VI.

In these examples, a copolymer obtained according to a / of example I is used and, according to the method described under 1-b, condensation is carried out, while maintaining the molar amounts indicated under 1-b:

Example * IV: 3- (2,4,6-trimethyldecyl) oxypropylamine providing the additive IV;

Example V: 1-amino 16-hexadecanol leading to additive V.

Example VI: 1,3-N, N-dodecyldiaminopropane providing the additive VI.

Additives I to III are used in the form of solutions with 50% dry matter in heptane, additives IV to VI in the form of solutions of the same content in toluene.

The efficacy of the additives described in these examples has been tested with two ARAMCO gas oil fractions, hereinafter denoted by and G2, the properties of which are indicated in Table A below.

8302012 "'Ί .....

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Table A.

r, _, niSr. Dest-1--3 = ^ ti — AS ™ · -% Distilled Volume- 0ι ~ Start Point End Point at 3.50 ° C Weight at _ (£ C) _ (fC) _15 ° (kg / 1)

Gx 181 382 89 0.846 5 G2 186 385 87 0.847

Additives I to VIII are included in an amount of 0.1% by weight in the above-described gas oil fractions G ^ and g2 *

Three determinations were made for each of the compositions thus formed: - cloud point according to the AFNOR T 60-105 method; - filterability temperature limit (TLF) according to the method AFNOR M-07-042; - pour point according to the AFNOR T 60-105 method.

15 The results of these determinations are summarized in Table B below.

Table B.

Cloud point (° C) T.L.-F. (° C) Pour point (° C) _

Add- G, G, G- seis ._1_2_1_2_1_2_ 20 without +2 +6 0 +3 -6 -3 0.1% I -1 +2 -4 0 -12 -15 0.1% II 0 +3 -4 0 -9 -9 0.1% III -1 +2 -3 -1 -12 -12 0.1% IV 0 +3 -3 0 -9 -9 25 0.1% V -1 +2 -3 - 1 -12 -9 0.1% VI -1 +2 -4 -1 -12 - 9

Example VII.

In this example, the anti-corrosion effect of the additive I of Example I was examined.

The compound I is used in the two previously described gas oils G1 and G2 in a concentration of 0.01% by weight.

The corrosion test consists of the examination of the synthetic seawater corrosion of cylindrical steel or polished iron test rods, according to the modified ASTM D 665 standard as follows.

The temperature is 32.2 ° C and the duration is 20 hours.

The gas oils G ^ and G2 to which no additives have been added 8302012 -10- -''-V-.

give test bars with 100% rust on their surface and the two gas oils containing 0.01 wt% additive give intact test bars with 0% rust.

-Conclusions- 8302012

Claims (14)

1. Product particularly suitable as an additive for lowering the cloud point of middle distillates, characterized in that it has a molecular weight of 2000 to 10,000 and originates from the reaction of a copolymer containing: (A) units from of vinyl acetate and (B) units derived from at least one unsaturated α, β-dicarboxylic acid compound in the form of a diacid, lower alkyl diester or anhydride, with at least one compound of primary amine function corresponding to one of the general formulas 1 or 2 of the formula sheet wherein R is a monovalent saturated aliphatic group of 1 to 30 carbon atoms is selected from the groups -NH-, -NR'- wherein R 'represents a monovalent saturated aliphatic group of 1 to 30 carbon atoms and the oxygen atom- O-, n is an integer from 2 to 4, m is zero when Z represents the group -NH-, or an integer from 1 to 4 in all cases; and R 'is a saturated bivalent aliphatic group having 1 to 18 carbon atoms. 2. Product according to claim 1, characterized in that the copolymer contains about 50 mol% units (A) and about 50 mol% units (B). Product according to either of Claims 1 and 2, characterized in that the unsaturated α, β-dicarboxylic acid compound from which the units (B) originate consists of at least one maleic acid or alkyl maleic acid, a methyl, ethyl or propyl diester of a such an acid or a maleic anhydride or alkyl maleic anhydride. A product according to any one of claims 1 to 3, characterized in that the amine-functional compound (formula 1) consists of at least one straight primary monoamine having 12 to 24 carbon atoms. The product according to any one of claims 1 to 3, characterized in that the amine-functional compound of formula 1 "consists of at least one polyamine of formula 3 of the formula sheet wherein R is a straight alkyl group having 12 to 24 carbon atoms, n a integer from 2 to 4 and m an 8302012 ^ ~ -12- - r integer from 1 to 4. The product according to any one of claims 1 to 3, characterized in that the amine-functional compound of the formula 1 consists of at least one polyamine of the formula 4 to 5 wherein R and R 'are each a straight alkyl group containing 8 to 24 carbon represent atoms and R and R 'together contain 16 to 32 carbon atoms, n an integer from 2 to 4 and m an integer from 1 to 4. The product according to any one of claims 1 to 3, characterized in that the amine-functional compound of formula 1 consists of at least one etheramine of formula 5 wherein R represents an alkyl group having 12 to 24 carbon atoms, n is an integer of 2 to 4 and m an integer from 15. to 4. 8. A product according to any one of claims 1 to 3, characterized in that the amine-functional compound of the formula II consists of at least one amine alcohol of the formula HO - CH2 - R "- NH2, wherein R" is a straight alkylene group with 1 to 18 carbon atoms. 9. A product according to any one of claims 1 to 8, characterized in that the product is obtained by radical polymerization of suitable amounts of vinyl acetate and of at least one unsaturated α-8-dicarboxylic acid compound, diacid, light alkyl diester or anhydride, followed by condensation of the formed copolymer with at least one compound with primary amine function of formula 1 or 2 in an amount of at least 0.5 mol / mol unsaturated α, β-3. dicarboxylic acid compound used. The product according to claim 9, characterized in that the amount of the compound of primary amine function of formula 1 or 20.9 to 1.1 mol / mol is unsaturated α, 8-dicarboxylic acid compound used. 35 ïi. Product according to any one of claims 1 to 8, characterized in that the product is obtained by radical copolymerization of suitable amounts of vinyl acetate and of at least one unsaturated α, β-dicarboxylic acid compound consisting of at least one K-substituted; imide obtained 8302012 by preliminary reaction of an unsaturated a, 3-dicarboxylic acid compound with at least one compound with primary amine function of formula 1 or 2. -13- 12. A composition of a middle distillate, characterized in that it contains an important amount of middle distillate with a distillation range between 150 and 450 ° C and a small amount sufficient to lower the cloud point of at least one compound according to any one of claims 1 to 11. The composition of a middle distillate according to claim 12, characterized in that the middle distillate consists of a gas oil fraction with a distillation range with an initial temperature of 16Ό to 190 ° C to a final temperature of 350 to 390 ° C. A middle distillate composition according to any one of claims 12 and 13, characterized in that the amount of said product is 0.01 to 1% by weight. 15. A middle distillate composition according to claim 14, characterized in that the amount of said product is 0.01 to 0.2% by weight. 8302012 V s -2 ^ H (1) HO - CH2 - R ”- NH2 (2) R - NH - ^ WH2) n - HH - - H (3) RN - £ CH_) - NH H (4) ^ 2 nm R - O - £ <CHj> - NB H (5, 8302012