CS269596B1 - Two-component depressant ingredient - Google Patents

Abstract

The solution concerns a two-component depressant additive that improves the low-temperature properties of diesel fuel, which consists of 10 to 40% by mass. copolymers based on alkylene vinyl aoylates and alkylbemenes and/or polyalkylbenzenes. The additive can be used both in refineries during the production of diesel fuel, as well as for the secondary modification of the low-temperature properties of diesel fuel in the sphere of distribution and use.

Description

The invention aa relates to a two-component depressant additive to fuel for diesel engines, which improves its low-temperature properties.

The production of diesel fuel, often referred to as diesel fuel, usually involves the preparation of a mixture of kerosene and gas oil, which are obtained by distillation of crude oil, distillation of products from catalytic cracking, hydrocracking, visbreaking and other processes. Individual components or a part of them are hydrodesulfurized in order to achieve a sulfur content in the resulting fuel as prescribed by the requirements for its quality.

In the production of diesel fuel intended for consumption in winter or even in extremely cold weather conditions, additives are added to diesel fuel to improve its low-temperature properties, usually characterized by its pour point and/or low-temperature filterability. Such additives are referred to as pour point depressants and flow (filterability) improvers. Currently produced diesel fuel additives often feature both properties. The low-temperature properties of fuel for diesel engines can also be influenced by the distillation range of the components used or by the ratio of fractionally heavier and heavier components. Due to the required properties of the final fuel (viscosity, flash point) and the balance of the components produced, the possibilities of applying this method of adjusting the low-temperature properties of the fuel are relatively small and the above-mentioned additives are usually used.

Additives improving the low-temperature properties of diesel fuel (depressants) are polymers or copolymers with a low molecular weight (1000 to 4000). In their production, C8 to C10 olefins, alkylene acylates, e.g. vinyl acetate, alkyl acylates, unsaturated acids, e.g. methyl acrylate and others are usually used. Typical precursors are ethylene vinyl acetate and ethylene methacrylate copolymers and their physical and chemical mixtures, and recently also copolymers of alkyl or alkenyl esters of higher carboxylic acids. The recommended concentration of such additives is in the range of 50 to 1000 ppm, but in practice it does not exceed 300 to 400 ppm, especially due to the economic side of production (high cost of the additive, as well as the decreasing susceptibility of the fuel with increasing concentration of the additive. Depressant additives are added to diesel fuel continuously using a dosing pump or in a batch method during batch production of fuel. Due to the relatively high freezing point of these additives (10 to 20 °C), it is advantageous to pre-dilute this additive with the finished fuel or its component, especially in the discontinuous method of diesel fuel production. Such pre-dilution of the additive does not affect either the effect of the additive or the susceptibility of the diesel fuel to its addition, either negatively or positively.

However, it has been found and confirmed by detailed research that alkylbenzenes, polyalkylbenzenes and/or their mixtures, as well as by-products resulting from the production of alkylbenzenes by alkylation of benzene with alkenes or chloroalkanes, when used as solvents for additives improving the low-temperature properties of diesel fuel, increase the effect of these additives. Since the addition of the above compounds alone in the appropriate concentration does not change the low-temperature properties of diesel fuel, when used as solvents for depressants, synergism occurs, resulting in a higher effect of such a mixed two-component depressant additive than of the depressant additive alone.

The subject of this invention is therefore a two-component depressant additive which contains 60% to 90% by weight of alkylbenzene and/or polyalkylbenzene and/or a higher boiling by-product of reactions resulting from the production of alkylbenzenes or fractions obtained from it by distillation and 100 to 400% by weight of copolymers of the ethylene vinyl acetate and/or ethylene methyl methacrylate type. A preferred component of the additive according to the invention are also copolymers of alkyl or alkenyl esters of higher carboxylic acids.

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The alkyl functional group of the alkylbenzenes to polyalkylbenzenes forming the additive according to the invention contains 3 to 38 carbon atoms, with its most advantageous properties being achieved if the alkyl chain or alkyl chains contain 3 to 22 carbon atoms.

The saturated alkylbenzenes contained in the two-component depressant additive of the invention are usually used as petrochemical feedstock, e.g. for the production of alkali metal alkylbenzene sulfonates, or as feedstock for the production of other petrochemicals (phenol, styrene). The higher boiling product of the by-reactions in the production of alkylbenzenes is used as heating oil or, after removal of the alkylation catalyst by refining with clay or distillation, is used as feedstock for the production of heat transfer fluid or as a component of lubricating oils. This higher boiling product is a complex mixture of alkyl aromatics of various compositions and typically contains residual amounts of alkylbenzene as well as other hydrocarbons, such as dialkylbenzenes to polyalkylbenzenes, dialkyltetralins, tri- and polyalkyltetralins, diphenylalkanes, alkyldiphenylalkanes and other polycondensed, optionally alkylated aromatic hydrocarbons.

The two-component depressant additive according to the invention can be applied directly in the refinery during the production of diesel fuel or in the sphere of distribution and use of diesel fuel. Such an additive, as demonstrated in the examples, in addition to its higher effect compared to the depressant itself, also has other advantageous properties: a low freezing point and a high flash point, which significantly simplifies its handling both on an industrial scale (pumping, storage) and in the sphere of consumption when filling it into small containers. In addition, the higher effect of the additive according to the invention is also manifested when it is added to diesel fuel previously depressed by the same or another type of depressant, i.e. there is no reduction in the sensitivity of diesel fuel to the increasing content of the depressant, which is usually observed when using the depressant alone. In application tests, an exceptional effect of the two-component depressant additive according to the invention was observed. In these tests, the additive cooled to -15 °C or -20 °C was added to diesel fuel cooled to the same temperature. Since the cloud point of the diesel fuel used was -4 °C, the diesel fuel was cloudy from the precipitated paraffin crystals. After adding the additive according to the invention, the pour point and filterability of the diesel fuel thus added were determined. The results of the determination showed that the addition of the additive according to the invention achieved the same low-temperature properties of the diesel fuel as when adding the depressant additive at temperatures of 20 to 30 °C. A similar effect was not observed when adding the depressant alone, which therefore further indicates the advantageous properties of the depressant additive according to the invention, especially when applied in the sphere of distribution and use of diesel fuel, where it is possible to adjust the low-temperature properties of the diesel fuel in this way depending on the current weather conditions.

The usual dosage of the two-component depressant additive according to the invention is 0.05 to 0.5% by weight, depending on the low-temperature properties of the original diesel fuel and the desired low-temperature properties of the diesel fuel after the addition of the additive.

The following examples document the advantages and synergistic effect of using a two-component depressant additive according to the invention, but without the facts stated limiting the scope of the invention in any way.

Example 1

A depressant additive based on polyethylene vinyl acetate (Depressant 1) was dissolved in alkylbenzene, the alkyl groups of which contained 10 to 14 carbon atoms, at a temperature of 30 - 40 °C, so that the resulting two-component additive contained 80% by weight of alkylbenzene (Additive A).

In the part of diesel fuel intended for the summer period, Depressant 1 was dissolved at a temperature of 30 to 40 °C so that the resulting solution contained 20% by weight of Depressant 1 (Solution

CS 269 596 Bl depressant 1). From the above type of diesel fuel with the addition of 500, 1000, 1500» 2000 and 3000 ppm by weight of Additive A and equal amounts of Depressant 1 solution, pairs of model diesel fuel samples were prepared, which always contained the same concentration of Depressant 1, i.e. 100, 200, 300, 400 and 600 ppm by weight of pure Depressant 1. The freezing point of the samples prepared in this way was determined. Similarly, samples of the same diesel fuel to which pure alkylbenzene was added in a concentration corresponding to the samples with the addition of Additive A were analyzed.

The results obtained, which are presented in Table 1, show that the addition of pure alkylbenzene does not affect the pour point of diesel fuel. From the comparison of the results of the pour point determination of samples with the addition of Additive A and Additive Solution 1, it is clear that when using the two-component additive according to the invention (Additive A), a significantly lower pour point of diesel fuel is achieved than when using a solution of Depressant 1 in diesel fuel, and therefore a synergistic effect occurs. The results presented are also significant from a practical point of view, because by adding such a depressant additive (Additive A), diesel fuel suitable for operation in the winter season can be obtained from summer diesel fuel, even outside the diesel fuel production plant. In addition, the low freezing point of Additive A (-30 °C) compared to +15 °C of pure Depressant 1 or -3 °C of Additive 1 Solution allows its use even at low ambient temperatures, as stated in the description of the invention.

Example 2

The excess hot product of the side reaction! in the production of alkylbenzene was removed from the alkylation catalyst (Poylcondensate 1) after distillation of the alkylbenzene itself by refining with clay. 200, 400, 600 and 800 ppm of a depressant additive based on a copolymer of ethylene and vinyl acetate (Depresent 2) were added to the diesel fuel intended for summer use, which had a cloud point of -4 °C, a pour point of -14 °C and a filterability limit temperature of -3 °C, in the form of a 10% solution prepared similarly to Example 1, with the difference that a kerosene fraction was used as the solvent.

An amount of Depressant 2 was dissolved in Polycondensate so that the resulting zees in one case contained 90% by mass. (Additive B) in the second case 80% by weight. (Additive C) and in the third case 7% wt. (Additive D) Polycondensate 1.

Model samples of diesel fuel were prepared from the above-mentioned diesel fuel and Additives B, 0 and D so that they would have the same resulting concentrations of pure Depressant 2 as the samples to which it was added in the form of a solution in kerosene.

The freezing point and filterability temperature of the samples prepared in this way were determined in the above series. Similarly, samples of diesel fuel were analyzed, to which only Polycondensate itself was added in the same concentration as Additive B. The results of the analyses shown in Table 2 show that Polycondensate 1 itself does not affect the low-temperature properties of diesel fuel. The results also show that the synergistic effect of the mixture of Polycondensate 1 and Depressant 2 is highest in the region of 20% Depressant 2 and when increasing or decreasing its concentration, the synergism is destroyed.

Example 3

From a sample of Polycondensate 1 according to Example 2, fracoal was distilled off on a molecular evaporator with a wiped film at up to 400 °C.

The obtained fraction was mixed with a depressant additive based on a methacrylic acid ester copolymer (Depressant 3) so that the obtained solution (Additive E) contained 30% by weight of Depressant 3.

Model samples containing 200, 400 and 600 ppm by weight of pure Depressant 3 were prepared from diesel fuel with a freezing point of -12 °C and Depressant 3 or Additive E. The freezing point of the model mixtures thus obtained was determined.

The measured results, which are presented in Table 3, show that when using Additive 2, lower pour points of diesel fuel are achieved than when using Depressant 3 alone.

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Example 4'

The "depressant" solution: additive. in Pól,ycondensate 1 according to example 2 (PríaadáPC) was added in the amount: 2000 ppm mass..: to the summer, transitional and winter engine. diesel.

In the samples of biologicals thus added, the cloud point (B.Z.), freezing point (B.T.) and limit filterability temperature (CEPP) were determined.

These diesel fuels were similarly analyzed without the addition of Additive C. The measured results shown in Table 4 show that by adding Additive C, it is possible to prepare winter diesel fuel from summer diesel fuel and from pre-season and winter diesel fuel, it is possible to obtain diesel fuel enabling the operation of diesel engines in extremely cold conditions.

Table 1

Pour point (B.T.) /measured in °C/ of summer diesel fuel at various concentrations (ppm by weight) of a solution of depressant 1, additive A and alkylbenzene

Depr. 1 solution Ingredient A Alkylbenzene ppm B.T. ppm B.T. ppm ' B.T. 0 -9 0 - 9 0 - 9 500 —18 500 -22 400 - 9 1000 . -23 1000 -26 800 - 9 1500 -26 1500 -29 1200 - 9 2000 -28 2000 -32 1600 - 9 3000 -30 3000 -34 2400 - 9 4000 - 9 6000 - 9 8000 - 9 Table 2 The effect of the addition (ppm mass) of Depressant 2 in the form of Solution depr. . 2, Ingredients B, C and D, as well as Polycondensate 1 itself on low-temperature properties summer motor diesel

Concentration of Depressant 1 alone Freezing point (B.T.) in °C B, Polycondensate 1 Solution depr. 1 P r i B set C and D ,T. P.R.» 200 -· 26 - 28 - 30 - 29 - 14 1000 400 - 34 - 36 - 38 - 38 • 14 3000 600 - 36 - 38 - 40 - 39 - 14 5000 800 - 38 - 40 - 40 - 40 - 14 7000 - 14 9000 - 14 11000 Filtration (CFPP) in °C 200 - 12 - 14 - 14 - 14 - 3 1000 400 - 16 - 18 - 19 - 18 - 3 3000 600 - 19 - 20 - 21 - 20 - 3 5000 800 - 20 - 21 - 22 - 21 - 3 7000 - 3 9000 - 3 11000

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Table 3

Effect of the addition (ppm mass) of Depressant 3 and Additive E on the freezing point /data in °C/ of diesel fuel

Depressant 3 ppm Additive E B.T. ppm B.T. 200 - 30 667 - 34 400 - 36 1333 - 38 600 - 39 2000 - 42

Table 4

The effect of the addition of 2000 ppm Additives 0 on the low-temperature properties of diesel fuel for summer, transitional and winter periods /data in °C/

Diesel type (NM) Property No additives Additives C With an addition of 2000 ppm Ingredients 0 l<o tnrt NM B.Z. - 4 - 4 B.T. - 14 - 38 CFPP - 3 - 19 Transitional NM B.Z. - 9 - 9 B.T. - 19 - 40 CFPP - 10 - 22 Winter NM B.Z. - 10 - 10 B.T. - 28 - 46 ' CFPP - 16 - 29

Explanatory notes ;

B.Z. - cloud point

B.T. - freezing point

CPPP - filterability

Claims (1)

08 269 596 B1 5 Table 3 Effect of addition (ppm by weight) of Depresamte 3 and Additive E on pour point / data in ° C / diesel diesel Depressant 3 Additive E ppm B.T. ppm B.T. 200 - 30 667 - 34 400 - 36 1333 - 38 600 - 39 2000 - 42 Table 4 Effect of addition 2000 ppm Additives C on low temperature diesel fuel properties summer, transitional and winter season / in ° C / engine fuel type (NM) ) Property Without Addition CS Ingredients Additive 2000 ppmAdditives C 1i «j tnd NM BZ - 4 - 4 B.T. - 14 - 38 CPPP - 3 - 19 Transitional NM B.Z. - 9 - 9 B.T. - 19 - 40 CPPP - 10 - 22 Winter NM B.Z. - 10 - 10 B.T. - 28 - 46 CPPP - 16 - 29 Explanatory Notes B.Z. - cloud point B.T. - pour point CPPP - filterability PSEDMET OF THE INVENTION The two-component depressant additive improves the low-temperature properties of the inotoxic grade and comprises 10 to 40 wt. copolymers based on ethylnonynyl-acylate and / or alkylene methacrylate and 60% to 90% by weight of copolymers; alkylbenzene and / or polyalkylbenzenes and / or boiling of the top-reacting product is the result of the production of alkylbenzones from which the residues of the alkyladium catalyst and of the high molecular weight substances have been removed and / or distillate obtained therein, the alkyl group of the alkylbenzenes having 3 to 38 carbon atoms .