RU2401861C1 - Anti-wear additive for low-sulphur diesel fuel - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: anti-wear additive is used for low-sulphur diesel fuel in form of composition. The additive contains distilled tall oil or tall fat acids and head fraction of hydro-dewaxed diesel fuel at weigh ratio equal to (1-5): 1 correspondingly.

EFFECT: improved physic-chemical and consumer properties of additive, and high resistance to water, avoiding usage of de-emulsifier.

7 tbl, 6 ex

Description

The invention relates to oil refining and petrochemicals, specifically to additives that improve the lubricating properties of low-sulfur diesel fuels.

The special technical regulation “On requirements for automobile and aviation gasolines, diesel and marine fuel, jet fuel and heating oil”, approved on February 27, 2008 by Decree No. 118 of the Government of Russia, provides for a gradual transition to the production of diesel fuels with sulfur content of 0.035; 0.005 and 0.001 wt.%. However, such fuels are characterized by insufficient lubricating properties, as a result of which antiwear additives are added to them without fail.

From the patent No. 2686713 (US C10L 1/10, publ. 17.08.1954) known antiwear additive for diesel fuel, which is tall oil.

In order to prevent the formation of rust on metal surfaces in contact with these fuels, it is recommended that up to 60 ppm (0.006 wt.%) Of the aforementioned additive be introduced into diesel fuel.

A common feature of the known and claimed additives is their basis - products contained in tall oil.

From patent No. 2165447 (RU IPC ⁷ C10L 1/18, C10L 1/22, publ. 20.01.2001), a lubricating (anti-wear) additive for low-sulfur diesel fuel containing monocarboxylic and polycyclic acids is known. The additive consists of a combination of at least one saturated or unsaturated monocarboxylic aliphatic hydrocarbon with a linear chain comprising 12-24 carbon atoms, and at least one polycyclic hydrocarbon compound comprising at least two cycles, each of which is formed by 5-6 atoms, of which at most one is optionally a heteroatom, such as nitrogen or oxygen, and the others are carbon atoms. These two cycles usually additionally have two common, preferably vicinal, carbon atoms, the cycles being saturated or unsaturated, unsubstituted or substituted and containing at least one group selected from a carboxyl, aminocarboxylate, ester or nitrile group as a substituent.

If this combination is tall oil, then the amount of additives added to the fuel is more than 60 ppm (more than 0.006 wt.%).

A common feature of the known and claimed additives is the use in their compositions of the same tall oil processing products (a mixture of fatty and resin acids).

A disadvantage of the known additive is its low anti-wear efficiency in diesel fuel, coupled with a high consumption of additives.

The closest (prototype) in technical essence and the achieved result is an anti-wear additive for low-sulfur diesel fuel, known from patent No. 2289612 (RU IPC ⁷ С10L 1/18, С10L 1/16, С10L 1/08, publ. 20.12.2006), which is a composition of tall oil and propylene pentamers in a mass ratio of (3-9): 1.

Tall oil in the prototype are the following tall oil processing products: distilled tall oil and tall fatty acids.

The additive according to the prototype is obtained by mixing the calculated amounts of tall oil of distilled or tall fatty acids and propylene pentamers at 20-50 ° C.

The technical effect of the use of additives according to the prototype in the amount of 0.005-0.05 wt.% On fuel is to increase the anti-wear efficiency of the additive in diesel fuels.

The disadvantage of this additive is poor compatibility with water, as a result of which it is necessary to add a demulsifier in an amount of up to 1.0 wt.%.

The present invention is to expand the range of antiwear additives for low sulfur diesel fuel with satisfactory compatibility with water.

The technical result, the achievement of which ensures the implementation of the inventive anti-wear additives for low-sulfur diesel fuel, is:

- improving its physico-chemical and consumer properties,

- high resistance to water,

- eliminating the need for the use of a demulsifier.

The elimination of these drawbacks and the achievement of the claimed technical result from the implementation of antiwear additives for low-sulfur diesel fuel based on products of tall oil: tall oil distilled or tall fatty acids is carried out due to the fact that the composition additionally includes the head fraction of hydrodeparaffinized diesel fuel with a mass ratio of distilled tall oil (or tall fatty acids): head fraction of hydrodeparaffinized about diesel fuel equal to (1-5): 1.

The inventive anti-wear additive is obtained by sequentially mixing the calculated amounts of the above components at 20-50 ° C.

A comparative analysis of the prototype and the inventive antiwear additives for low sulfur diesel fuel shows that a common feature is their basis - products of tall oil processing: distilled tall oil or tall fatty acids.

A distinctive feature of the claimed antiwear additives for low-sulfur diesel fuel is that the composition further includes a head fraction of hydrodeparaffinized diesel fuel in a weight ratio of tall oil distilled (or tall fatty acids): the head fraction of hydrodeparaffinized diesel fuel is equal to (1-5): 1.

At the same time, high stability with respect to water does not follow explicitly from known theoretical principles.

Used in the preparation of the inventive additives components and their characteristics:

1. The physico-chemical characteristics of the head fraction of hydrodeparaffinized diesel fuel are presented in table 1.

2. Physico-chemical characteristics of tall oil distilled are presented in table 2.

3. Tall fatty acids are isolated by distillation of tall oil. Physico-chemical characteristics of tall fatty acids are presented in table 3.

The implementation of the invention and the possibility of obtaining the claimed technical result is shown in the following examples.

Example 1. The preparation of samples of antiwear additives for low sulfur diesel fuel.

To illustrate the proposed technical solution, additive samples were prepared by mixing (at a temperature of 35 ° C) components with the characteristics set forth in table 4.

In studies, tall oil distilled according to TU 13-00281074-26-95 is used (homogeneous liquid from light yellow to brown in color, density at 20 ° C 890 kg / m ³ , mass fraction of the main substance 98%, flash point 203 ° C, acid number 164 mg KOH / g), tall fatty acids according to TU 13-0281078-83-90 (acid number 191 mg KOH / g, flash point 220 ° C, mass fraction of resin acids 2.4%) and the head fraction of hydrodeparaffinized diesel fuel (boiling end temperature of 265 ° C, density at 20 ° C 813 kg / m ^3, the mass fraction of aromatic hydrocarbons odov 0.8%).

Example 2. The study of compatibility with water.

Compatibility with water, antiwear and other properties of additives were checked by introducing additives into low-sulfur diesel fuel produced by ANKhK OJSC with the following characteristics.

The concentration of additives in the fuel from 0.005 to 0.05 wt.% Was adopted - this is the range of working concentrations accepted for additives of this type.

Compatibility with water was checked by the method of DGMK 531, which is included in the set of methods for the qualification assessment of diesel fuels.

The DGMK 531 method allows one to evaluate the propensity of a fuel containing an additive to form stable fuel-water emulsions. To do this, a certain amount of buffer solution (pH = 7) and the test fuel are introduced into the cylinder. The cylinder is closed and placed horizontally in a mixer for 5 minutes (frequency 140-150 cycles / min).

After settling for 24 hours at room temperature, the phase boundary is optically determined. If an insignificant emulsion is formed or its absence (grade 0-2), the fuel phase is carefully sucked off without touching the intermediate layer (emulsion), while a small amount of fuel should remain above the intermediate layer, then the cylinder is again refilled with the original fuel to the original volume.

If the emulsion score is higher than 2, then the described steps are repeated 4 times. The results are entered in the corresponding table. If the fuel has passed the test, then the rating is entered after 5 test cycles. If the fuel test fails, then the rating and the cycle number in which the emulsion first appeared are entered in the table.

Evaluation of the test results is carried out according to a special table (table 5).

Using both methods makes it possible to confirm the results when testing diesel fuels with additives for interaction with water.

The study of the compatibility of fuels with additives with water is presented in table 6.

According to the methodology, the prototype additive at a concentration of 0.05 wt.% Did not pass the test. The test results at a concentration of 0.005 wt.% Are at the limit. The proposed additive (samples 1-5) was tested with a positive result. Sample 6 failed.

Example 3. The study of antiwear additives.

The anti-wear efficiency of additives was tested in diesel fuel containing 0.005 wt.% Sulfur, which meets the requirements of the 4th quality category of the Special Regulation on fuel and lubricants (Euro-4). From fuel was introduced from 0.005 to 0.05 wt.% Of the proposed additives. The tests were carried out according to the method of American standard ASTM D 6079, included in TU 38.401-58-296-2001 "Diesel automotive fuel". According to this method, a steel ball under a load of 20 kPa (0.2 kg / cm ² ) by means of a vibrator performs reciprocating movements with an amplitude of 1 mm and a frequency of 50 Hz along a plate placed in the test medium. Tests are carried out at temperatures of 60 and 25 ° C (it is taken into account that in a running engine the fuel is in a heated state). The resulting wear spot is measured in two diameters (in the direction of travel and across) and the average is calculated. Then, the temperature and humidity are corrected, and the final result D obtained is a characteristic of this sample. The norm of antiwear properties of diesel fuel according to EN-590 and TU 38.401-58-296-2001 is D≤460 microns. The recommended value, providing a margin of antiwear properties, is ≤410 microns.

The test results are presented in table 7. The table shows that the anti-wear efficiency of the additive of the proposed composition corresponds to the prototype. Sample 2, which goes beyond the limits of the tall oil distillation ratios: the head fraction of hydrodeparaffinized diesel fuel is characterized by insufficiently high anti-wear properties (the diameter of the wear spot goes beyond 410 μm).

Table 1 Physico-chemical characteristics of the head fraction of hydrodeparaffinized diesel fuel Name of indicator Norm according to DK 04-21303-019-2004 Actual figures Boiling point temperature, ° С no higher than 270 220-270 Density at 20 ° С, kg / m ³ no more than 820 800-820 Mass fraction of aromatic hydrocarbons,% no more than 2 1-2

table 2 Physico-chemical characteristics of tall oil distilled Name of indicator Norm according to TU 13-00281074-26-95 Actual figures Appearance Light yellow to brown homogeneous liquid Compliant Density at 20 ° С, kg / m ³ 850-900 850-900 Mass fraction of the main substance,% not less than 95 80-95 Flash point, ° С not lower than 200 200-210 Acid number, mg KOH / g not lower than 140 140-160

Table 3 Physico-chemical characteristics of tall fatty acids Name of indicator Norm according to TU 13-0281078-83-90 Actual figures Acid number, mg KOH / g not lower than 185 185-210 Flash point, ° С not lower than 213 213-225 Mass fraction of resin acids, wt.% no more than 3 2-3

Table 4 Additive Composition Samples Component one 2 3 four 5 6 Distilled tall oil, wt.% 70 40 fifty - - - Tall fatty acids, wt.% - - - 70 80 85 The head fraction of hydrodeparaffinized diesel fuel, boiling up to 290 ° C 60 fifty thirty twenty fifteen Polyalkylbenzenes thirty - - - - - The ratio of the components: Prototype 0.7: 1 1: 1 2.3: 1 4: 1 5.7: 1

Table 5 Phase boundary scorecard Scoring Description 0 No film one Torn film, not closed 2 Closed film 3 Starting emulsion, 1/8 aqueous layer four - "-, 1/4 of the water layer 5 - "-, 3/8 water layer 6 - "-, 1/2 water layer 7 - "-, 2/3 of the water layer 8 - "-, 3/4 of the water layer 9 - "-, 7/8 water layer 10 The entire aqueous layer is an emulsion

Table 6 Assessment of the compatibility of fuels containing antiwear additives with water Fuel Additive The concentration of additives, wt.% Number of cycles Points Diesel without additives - 5 0 Prototype 0.005 5 3 Prototype 0,050 four four The proposed additive samples: one 0,025 5 one 2 0.005 5 0 3 0,020 5 0 four 0,030 5 one 5 0,050 5 2 6 0,025 5 four

Table 7 Diameter of wear spots during fuel tests with additive compositions Example according to table 1 Concentration in fuel, wt.% D, μm No additive - 555 1 (prototype) 0,025 380 2 0,025 413 3 0,025 375 four 0,025 381 5 0,025 385 6 0,025 366 1 (prototype) 0.005 406 four 0.005 404 1 (prototype) 0.05 314 four 0.05 315

Claims (1)

Anti-wear additive for low-sulfur diesel fuel based on tall oil of distilled or tallow fatty acids, characterized in that it further includes a head fraction of hydrodeparaffinized diesel fuel in a weight ratio of distilled tall oil (or tall fatty acids): the head fraction of hydrodeparaffinized diesel fuel is equal to (1- 5): 1.