CS269692B1 - Mixed additive into fuel oils, oils and fuels for compression ignition engines - Google Patents

Abstract

The solution relates to the mixed additive to fuel oil and fuel for diesel engines improving their low temperature features. The mixed additive contains a copolymer of ethylene and vinyl acetate containing % of vinyl acetate from 17 to 55% by weight, in low molecular weight polyethylene formed as the leading product for low- a. high density polyethylene and a hydrocarbon solvent which it consists of low-boiling hydrocarbon processing fractions paraffinic and semi-paraffinic oil or in solvent dewaxing petroleum distillates or alkylbenzenes i above boiling productions from the secondary reactions in the production of alkylbenzenes.

Description

The present invention relates to a blended additive for diesel fuels and oils and fuels for diesel engines, which improves their low temperature properties. '

At present, there are increasing demands for low-temperature fuel properties for diesel engines, often referred to as diesel, characterized in particular by cloud point, pour point and filterability limit temperature.

In diesel that I do not contain! Additives that improve the low-temperature properties of the fuel (depressants) are eliminated at low temperatures! crystals of n-alkanes in the form of relatively large thin dots, which tend to fuse into larger clusters. If a depressant is present, it is added on the surface of the emerging n-alkane crystals, as a result of which further crystal growth is only possible at the corners. The crystals of the n-alkanes thus modified are fine and therefore the pumpability of the fuel is improved. The mechanism of action of depressants in diesel at lower temperatures is not yet fully understood. According to the classical theory of crystallization of n-alkanes at low temperatures, the interaction of depressant and n-alkane molecules occurs only after the formation of the crystalline phase of paraffins. Based on the more recent theory, aa assumes that the mutual iteration between the additive and the selected n-alkane molecules occurs before the precipitation of higher n-alkane crystals. The n-alkanes present in the petroleum fractions form non-molecular structures which can exist independently at temperatures higher than the crystallization temperature of the individual n-alkanes.

Depressive molecules attack! molecules of n-alkanes in the stage of formation of supramolecular structures and form complexes with them, therefore the added additive to diesel acts to agglomerate n-alkanes at temperatures higher than their crystallization temperature. The effect of the added depressant depends mainly on the chemical structure of the additive itself, on the method of its preparation, on the properties and composition of the components used in the production of diesel fuels. . - ·

Depressive additives improving the low-temperature properties of diesel forces Especially polymers with a characteristic molecular weight. They use! has reached less than 650 ppm, but in most cases it is sufficient to add less to achieve the required low-temperature properties of diesel fuel.

They are added to diesel fuels! depressants based on copolymers of alpha-olefins and ethylene, ethylene and vinyl acetate, ethylene and alkyl methacrylates, resp. chlorinated hydrocarbons. The best-known representatives are the copolymer of ethylene and vinyl acetate (EVA copolymer) β with a vinyl acetate content of from 17 to 53% by weight, resp. ethylene and alkyl methacrylate (EMA copolymer) with a relative molecular weight of 1,000 to 2,500 units.

Authors Csl. AO 216286 proposed the application of low molecular weight polyethylene obtained in the production of low density polyethylene by a high pressure process, which is suitable as a lowering point of the solidification temperature of diesel fuels from paraffinic oils, but has no significant effect on fuel filterability. This can be explained by the fact that low molecular weight polyethylene may also contain fractions with substantially higher molecular weights, which is reflected in its deteriorated solubility and loss of depressant activity due to reduced filterability. This deficiency is eliminated by the treatment of low molecular weight polyethylene in the Sel. AO 253442 by separating more sparingly soluble higher fractions in the hydrocarbons by settling or filtration. However, a more preferred epabetone is rubbing using a hydrocarbon dispenser. The depressant thus prepared with a relative molecular weight of 1500 to 3000 units makes it possible to more effectively reduce the low-temperature properties of diesel fuels, heating oils and oils.

The essence of the invention is the application of a mixed additive to heating oils and oils and fuel for diesel engines, which significantly reduces their low-temperature properties in comparison with the hitherto mentioned depressants.

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The blend additive according to the invention contains from 3 to 35% by weight, a copolymer of ethylene and vinyl acetate and from 17 to 55% by weight of vinyl acetate, from 2 to 35% by weight, of low molecular weight polyethylene formed as a by-product in high-density polyethylene production. hydrocarbon-insoluble heavier fractions removed by settling, filtration or centrifugation and from 30 to 95% by weight of a hydrocarbon solvent consisting of low-solids hydrocarbon fractions obtained in the processing of non-paraffinic or semi-paraffinic oil and / or in the solvent dewaxing / dewaxing of petroleum oils From the side reactions in the production of alkylbenzenes from which the residues of the alkylation catalyst and the high molecular weight coking agents and / or the fractions obtained from it have been removed, the alkyl group of alkylbenzenes contains from 3 to 52 carbon atoms.

The presence! The mixed additive according to the invention has the effect of influencing the growth of crystals of n-alkanes precipitated at lower temperatures. The presence of both components in diesel results in polyethylene forming seed centers for the crystallization of n-alkanes and the EVA copolymer modifying the surface of the precipitated n-alkanes. The application of the mixed additive according to the invention results in a limited growth of crystals, which results in a significant reduction in the solidification temperature and filterability of the diesel fuels. It has been found experimentally that the mixed additive has a higher effect compared to the use of the copolymers alone, and thus synergism occurs in the application of such a mixed additive according to the invention. It has been shown that the highest synergistic effect is obtained when the blended additive contains lighter proportions of low molecular weight polyethylene soluble in alkylbenzenes or higher boiling products from side reactions in the production of alkylbenzenes and ethylene / vinyl acetate copolymer containing 35 to 40% by weight of vinyl acetate. ratios from 3.5: 1 to 12.5: 1, preferably from 4.8: 1 to 10.6: 1.

I document the following examples! advantages and synergistic effects in the application of the mixed additive according to the invention, without, however, limiting the facts in any way limiting the subject matter of the invention.

Example 1

Low molecular weight polyethylene with a relative molecular weight of 4200 units was obtained as a by-product in the production of polyethylene by the high-pressure process. After dissolution in a hydrocarbon solvent formed by alkylbenzenes and higher-boiling by-products of cumene by-products from which alkylation catalyst residues and high-molecular coke formers have been removed, low-molecular-weight polyethylene was centrifuged in a laboratory flask in the form of a 10% solution. type ALFA LAVAL LAPX 202 at 9000 revolutions per minute for 20 minutes. By centrifugation at room temperature and from it, the less soluble fractions in the hydrocarbon solvent were removed, which were communicated in the resulting lower layer containing 19.9% by weight, heavier fractions of flooded low molecular weight polyethylene. The upper clear layer containing 80.1% by weight, heavier portions of low molecular weight polyethylene with a relative molecular weight of 1050 units (Component 1) was used in the preparation of the mixed additive according to the invention.

A copolymer of ethylene and vinyl acetate containing 38.7% by weight of vinyl acetate (Component 2) was dissolved in Component 1 at 40 ° C so that the mutual weight by weight of

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- 3 The ratio of Component 1 to Component 2 was 9: 1. The prepared blended additive 1 was used as an additive to winter type diesel to reduce its low temperature properties. The solidification temperature and filterability of said diesel at low temperatures were monitored at different concentrations of blended additive 1. A comparison of the depressant effect of blended additive 1 (according to the invention) and Components 1 to 2 (outside the invention) is given in Table 1. The measured results show that application of the mixed additive 1 leads to a synergistic effect in determining the solidification temperature and filterability of winter type diesel fuel. This means that with lower dosages of Component 2 in the mixed additive 1, it is possible to achieve better low-temperature properties of the diesel than in the case of using the additives of Components 1 and 2.

Example 2 *

From the low molecular weight polyethylene with a negative molecular weight of 4400 units soluble in the hydrocarbon solvent, formed by the low-solidifying hydrocarbon fractions obtained by solvent dewaxing of petroleum distillates, in the form of a 5% solution, the heavier fractions were separated by settling. heavier, hydrocarbon-soluble fractions (Additive 4) were used as an additive to reduce the pour point and filterability of transient diesel.

A copolymer of ethylene and vinyl acetate containing 40.6% by weight of vinyl acetate (Additive 3) was added to Additive 4 at 35 ° C so that in Mixed Additive 2 the ratio of Additive 3 to Additive 4 was 1: 5 · From diesel and additives Additive 3 to 4, resp. model additive 2, model samples were prepared for which the pour point and filter aid were determined. The measured results shown in Table 2 show that the application of the Modified Additive 2 (according to the invention) achieves lower values for the low-temperature properties of model diesel fuel samples compared to the application of additives outside the invention (Additives 3 and 4). .

Example 3

The low molecular weight polyethylene with a relative molecular weight of 4320 units, prepared according to the method of Example 1, was dissolved in a hydrocarbon solvent consisting of low-solids hydrocarbon fractions and a fraction ranging from 183 to 335 ° C obtained by processing non-paraffinic and semi-paraffinic petroleum. Heavier portions of low molecular weight polyethylene were collected on activated carbon under pressure filtration, and the obtained filtrate containing 83.2% by weight, lighter portions of aqueous low molecular weight polyethylene was used as a component (Solution B) in the preparation of the modified additive. 3. Mixing a copolymer of ethylene and vinyl acetate containing 39.4% by weight of vinyl acetate / Additive 5 / * solution B in a weight ratio of 1: 5 gave a mixed additive 3.

From the diesel period for the summer period and the mixed additive 3 (according to the invention) and the additive 5 (outside the invention), model diesel blends were prepared so as to have the same final EVA copolymer concentration (100, 200 and 300 ppm). The cloud point, solidification temperature and filterability limit temperature were determined for these model mixtures. Based on the achieved experimental results (Table 3), it can be stated that the application of the mixed additive 3 achieves better low-temperature properties of the diesel compared to the use of the Additive 5 alone.

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Example 4

The modified additive 3 prepared according to Example 3 was added to the diesel fuel for smoking ea so as to have a final EVA copolymer concentration of 100, 200 and 300 ppm. The solidification temperature was determined for the prepared samples. The experimentally obtained data are shown in Table 4 and are compared with the solidification temperature of heating diesel fuel without an additive improving its low-temperature properties.

Example 5.

From the heating oil for the winter period and the mixed additive 2 according to the invention, model mixtures of heating oil were prepared to contain 1000, 2000 and 3000 ppm of the mixed additive 2. The cloud point and the solidification temperature were determined for the model mixtures. The measured results are shown in Table 5 and are compared with the low-temperature properties of the depressant-free heating oil.

Table 1

Low-temperature properties of winter-type diesel fuel at various concentrations

Mixed additive 1 (according to the invention) and additives of Components 1 and 2 (outside the invention)

Type of depressant and its dozen Low temperature properties in ° C in ppm Freezing point Filterability Mixing additive 1 / according to the invention / without additive - 18 - 9 1000 - 30 - 15 2000 - 37 - 18 3000, - 41 - 20 4000 - 43 - 21 Component 1 / outside the invention / without additives - 18 - 9 3000 - 24 . - 11 4000 - 28 - 12 6000 - 30 - 13 8000 - 31 - 14 Component 2 / outside the invention / without additive - 18 - 9 200 - 29 - 14 400 - 33 - 18 600. - 36 - 20 800 - 37 - 21

Table 2 ·.

Influence of the addition of Mixed Additive 2 (according to the invention) and the additives Additives 3 and 4 (outside the invention) on the low-temperature properties of diesel fuel of the transitional type

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Freezing point ° C Filterability ° C Additive 4 / outside the invention / without additive - 17 - 7 1000 ppm - 21 - 9 3000 ppm - 25 - 10 5000 ppm - 27 - 12 10000 ppm - 28 - 13 Additive 3 / outside the invention / 100 ppm - 24 - 10 200 ppm - 28 - 13 300 ppm - 30 - 15 500 ppm - 31 - 16 Mixing additive 2 (according to the invention) 600 ppm - 27 - 12 1200 ppm - 32 - 16 1800 ppm - 35 - 18 2400 ppm - 37 - 19 3000 ppm - 38 - 20

Table 3 '.

The effect of the addition (ppm by weight) of the mixed additive 3 (according to the invention) and the additive 5 (outside the invention) at the same concentration of EVA copolymer, resp. Solution B (outside the invention) for the low temperature properties of summer diesel

Freezing point ° C Filterability ° C Turbidity temperature ° C Solution B (outside the invention) without additive - 12 - 2 - 3 500 - 14 - 6 - 3 1000 - 15 - 7 - 4 1500 - 15 - 8 - 3 Additive 5 (outside the invention) without additive - 12 - 2 - 3 100 - 18 - 8 - 3 200 - 22 - 11 - 3 300 - 24 - 13 - 4 Mixed additive 3 (according to the invention) without additive - 12 - 2 - 3 600 - 20 - 11 - 4 1200 - 25 - 15 - 4 1800 - 28 - 17 - 3

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Table 4

Influence of the addition of mixed additive 3 on the solidification temperature of diesel fuel for fumigation e

Concentration of EVA copolymer in the mixed additive 3 ppm Freezing point ° C without additive - 6 100 - 13 200 - 17 300 - 19

Table 5

Influence of the addition of mixed additive 2 on the low-temperature properties of heating oil

Addition of mixed additive 2 ppm Turbidity temperature ° C Freezing point ° C without additive ♦ 23 * 19 1000 + 23 + 3. 2000 + 23 - 7 3000 . + 23 - ¹¹

OBJECT OF THE INVENTION

Claims (2)

OBJECT OF THE INVENTION A mixed additive for heating oils and oils and fuels for diesel engines improving their low-temperature properties, characterized in that it contains from 3 to 35% by weight, a copolymer of ethylene and vinyl acetate and a vinyl acetate content of from 17 to 55% by weight. of low molecular weight polyethylene formed as a by-product in the production of low density polyethylene by a high pressure process from which hydrocarbon insolubles have been removed by settling by filtration or centrifugation and from 30 to 95% by weight of a hydrocarbon solvent consisting of low-solids from treatment of non-paraffinic or p-paraffinic crude oil and / or hydrocarbon fractions obtained from the solvent dewaxing of petroleum distillates boiling up to 485 ° C and / or alkylbenzenes and / or higher kiln by-products from the production of alkylbenzenes from which the residue high molecular weight coking agents substances and / or fractions obtained from it by distillation, the alkyl group of the alkylbenzenes containing from 3 to 52 carbon atoms.