RU2464299C1 - Method for production of winter euro diesel fuel - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: oil raw materials after desalination and dehydration are supplied to a stripping tower, where in process of fractionating partially stripped oil is removed from the tower top and from the tower bottom, and oil is supplied to the main fractionating tower K-2, from where into stripping towers K-3/1, K-3/2, K-3/3 virgin distillates are removed, and then by mixing of a flow from a stripping tower K-3/1 with balance quantity of the flow from the stripping tower K-3/2 a winter diesel fuel is produced, characterised by temperature of boiling start of not below 159°C, with density of 800-815 kg/m³ and content of fractions in it, boiling up to 180°C, not more than 10 wt %, and by mixing of the flow from the stripping tower K-3/3 with the remaining part of the flow from the stripping tower K-3/2, a summer diesel fuel fraction is produced with flash point temperature of more than 55°C and cloud temperature not higher than minus 3°C. Separate hydraulic treatment is carried out on produced virgin fractions of diesel fuels with further additional removal at blocks of stabilisation of light hydrocarbon fractions hydraulic treatment plants, basic fuel is produced by compounding of hydraulically treated virgin fractions of winter diesel fuel and summer diesel fuel at the ratio of components 97-60:3-40 wt %, accordingly, and additionally a depressor-dispersing additive is added into the produced basis fuel in the amount of not more than 150 ppm.

EFFECT: production of winter diesel fuel corresponding in its quality characteristics to European quality standards with minimisation of costs for its production.

1 dwg, 6 tbl, 5 ex

Description

The invention relates to processes of the oil refining industry, in particular to methods for producing winter diesel fuels from products of direct distillation of oil.

Modern European standards impose significantly tougher requirements for quality indicators of winter diesel fuel. The requirements for the flash point of diesel fuel (above 55 ° C) differ significantly from the requirements of GOST 305-82 (not lower than 35 ° C). The requirements for cetane number depending on the fuel class (47-49 units) are also higher than the requirements of GOST (not less than 46 units). At the same time, fairly stringent requirements for the low-temperature properties of the fuel must be met, such as a cloud point (depending on the fuel class: from minus 10 ° C to minus 34 ° C) and the limiting filterability temperature (from minus 20 ° C to minus 44 ° C ), and environmental indicators: requirements for the content of sulfur compounds - from 10 to 350 mg of sulfur per kg of fuel, depending on its type.

Technological schemes for the production of fuels in Russia were calculated mainly on the production of winter diesel fuel in accordance with GOST 305-82, therefore, the production of diesel fuel of a European level of quality requires the introduction of new technical solutions.

Well-known methods for producing winter diesel fuel are the use of various options for compounding straight-run fractions obtained in the process of oil separation at AT or AVT units in the main distillation column K-2: as a rule, into fractions - kerosene (FR 120-240 ° C, stripping K -3/1), a light diesel fraction (fr. 200-320 ° C, stripping K-3/2), a heavy diesel fraction (fr. 240-360 ° C, stripping K-3/3). A portion of the K-3/2 and K-3/3 stripping mixture is hydrotreated. Winter diesel fuel according to GOST 305-82 with a pour point of minus 35 ° C and a cloud point of minus 25 ° C is produced by compounding fractions from strips K-3/1 and K-3/2. In the production of low sulfur diesel fuel, the fractions are hydrotreated. ("Fuel, lubricants, technical fluids." Reference. M: Chemistry, 1989, p.65).

However, these methods of producing winter diesel fuel do not allow to obtain fuel that meets European quality standards, in particular according to environmental indicators - sulfur content, flash point, and maximum filterability temperature.

A known method of producing environmentally friendly Arctic diesel fuel (RF patent No. 2205862, C10L 1/08), which includes the allocation by direct distillation of oil kerosene fraction, 96% of which boils up to 250 ° C, fraction, 96% of which boils up to 320 ° C, their compounding with the addition of T-6 commercial jet fuel with the following ratio of components: 20-25% of the kerosene fraction, 96% of which is distilled to 250 ° C, 1-10% of the fraction, 96% of which is distilled to 320 ° C, and 70- 74% of T-6 commercial jet fuel. This invention helps to reduce the cloud point and improve the environmental properties of the resulting fuel.

However, this method significantly reduces the production resources of no less scarce jet fuel, does not allow the involvement of fractions boiling over 320 ° C, which significantly limits the raw material base for the production of winter diesel fuel. In addition, this method does not ensure the achievement of modern requirements for sulfur content and flash point.

A known method of producing winter diesel fuel (RF patent No. 2039080, C10G 45/04) by primary distillation of oil with the allocation of fractions 130-240 ° C (stripping K-3/1), fraction, 96% of which is distilled within 140- (280 -310) ° C (stripping K-3/2), and fractions, 96% of which are distilled at 210- (340-350) ° C. A mixture of the last two fractions in a ratio of 10: 90-35: 65 is subjected to hydrotreating under known conditions at a known catalyst at 370 ° C, a pressure of 35 atm, a feed space velocity of 3 h ^-1 . The obtained fraction of hydrotreated diesel fuel is combined with the initial straight-run fraction of summer diesel fuel, 96% of which boils in the range 210- (340-350) ° C. Compounding is carried out in a ratio of 10: 90-90: 10. To the resulting mixture of diesel fractions is added in an amount of 30-50% of the initial straight-run fraction of winter diesel fuel, 96% of which boils within 140- (280-310) ° C. A depressant additive is introduced into the obtained base fuel with a cloud point of minus 14 ° C - minus 20 ° C, which allows to lower the pour point and the maximum filterability temperature respectively below minus 35 ° C and minus 25 ° C.

However, this method of producing winter diesel fuel does not provide modern requirements for fuel quality in terms of sulfur content, flash point, limiting filterability temperature and cloud point.

The closest in technical essence and the achieved result is a method for producing winter diesel fuel (RF patent No. 2237701, С10G 45/02) from sulfur oils using oil distillation, hydrotreatment, compounding fractions and the introduction of a depressant additive - ethylene vinyl acetate copolymer, and with primary the distillation of oil allocate fractions, 96% of which boils within 140- (280-290) ° C and 305- (390-405) ° C. Then the fraction 140- (280-290) ° C is subjected to hydrotreating and the resulting product is mixed with fractions 305- (390-405) ° C in a mass ratio from 75:25 to 95: 5. Then, a depressant additive is introduced into the obtained base fuel - a copolymer of ethylene with vinyl acetate in an amount of 0.01-0.05 wt.%.

The proposed method provides for the production of winter diesel fuel with low temperature characteristics (cloud point minus 15 ° C, maximum filterability temperature minus 25 ° C, pour point minus 35 ° C) that meet the requirements of TU 38.401-58-36-92. However, the proposed method for producing winter diesel fuel does not allow to obtain a similar fuel of the European level, with the achievement of the necessary environmentally significant characteristics for the content of sulfur compounds in the fuel, as well as characteristics such as flash point, cetane number.

The aim of the present invention is to obtain winter diesel fuel Euro, corresponding in its quality characteristics to European quality standards (flash point above 55 ° C, cetane number above 48, cloud point not higher than minus 22 ° C, maximum filterability temperature not higher than minus 32 ° C) while minimizing the cost of its production.

This goal is achieved by a method including the primary distillation of oil with the removal of straight-run fractions of diesel fuels, hydrotreating straight-run fractions, compounding hydrotreated straight-run fractions and the subsequent introduction of additives. In this case, the crude oil after desalting and dehydration is fed to the topping column, where gasoline is removed from the top of the column during the fractionation process, and partially topped oil is removed from the bottom of the column, which is fed to the K-2 main fractionation column, from where to K-3 stripping columns / 1, K-3/2, K-3/3 remove straight-run distillates and then by mixing the stream from the K-3/1 stripping column with the balance amount of the K-3/2 stripping column stream, get a fraction of straight-run diesel winter fuel preset characteristics: pace the boiling point of at least 159 ° С, a density of 800-815 kg / m ³ and the content of fractions boiling up to 180 ° С in it, no more than 10% wt., and by mixing the flow from the K-3/3 stripping column the remaining amount of the K-3/2 stripping column stream receives a fraction of straight-run diesel summer fuel with a flash point above 55 ° C and a cloud point of no higher than minus 3 ° C, then each of the selected diesel fuel fractions is hydrotreated, then additionally on the units stabilization units hydrotreating from hydrotreated straight run fractions of diesel fuels remove fractions of light hydrocarbons by stabilizing them and then obtain basic diesel fuel by compounding hydrotreated straight-run fractions of diesel winter fuel and diesel summer fuel with a component ratio of 97-60: 3-40% wt. respectively, and additionally, a depressant-dispersing additive in an amount of not more than 150 ppm is added to the obtained base fuel.

The method is as follows (see the attached diagram). Petroleum feedstock - Crude oil (1) is fed to the ELOU unit (2), where the feedstock is subjected to electric desalting and dehydration in order to remove salts and water contained in it. Then, the prepared oil is fed to the atmospheric distillation unit with double evaporation, to the topping column (3), where gas is removed from the top of the column during fractionation, and partially topped oil is removed from the bottom of the column (4), which, after additional heating (5), is fed to the main fractionation column K-2 (6). In the K-2 column, which has 42 plates, the third circulation irrigation is supplied from 12 to 14 plates, and from the 15 plate, straight-run diesel fuel is taken to the K-3/3 stripping column (9), the second circulation irrigation is fed from 22 to 24 plate, and from 25 plates, straight-run diesel fuel is transferred to the K-3/2 stripping column (8), the first circulation irrigation is fed from 32 to 34 plates, and from the 35 plate, the fraction of straight-run jet fuel is transferred to the K- stripping column 3/1 (7). From the top of the K-2 column, gasoline is selected, while irrigation is fed to the upper 42nd plate. The fraction of straight run winter diesel fuel in order to achieve the specified quality parameters is obtained by mixing the stream (10) from the K-3/1 stripping column with the balance amount of the stream (11) of the K-3/2 stripping column (the ratio of the mixed streams depends on the quality characteristics of the processed crude oil and, in the case of processing a mixture of West Siberian and Ukhta oils, can vary between 90: 10-35: 65), and the fraction of straight-run diesel summer fuel in order to achieve the specified quality parameters is obtained by mixing stream (12) from the stripping column K-3/3 with the remainder of the stream (11) from the stripping column K-3/2. The winter straight-run diesel fuel fraction has the following characteristics: the boiling point is at least 159 ° С, the content of fractions boiling up to 180 ° С in it is not more than 10% wt., The density is in the range 800-815 kg / m ³ . Obtaining a fraction of straight-run diesel fuel with a boiling point not lower than 159 ° C determines the first stage of removal of light fractions and allows you to provide a flash point above 55 ° C further, on the stabilization unit of the hydrotreating unit. These quality indicators are achieved with the following process parameters: the temperature of the top of the K-2 column is 138-142 ° C; temperature on the 35th plate - 165-172 ° С; the temperature of the input of raw materials into the K-2 column is 355- 365 ° C, the pressure in the column is 0.3-0.4 ati and the corresponding balance ratio of flows from K-3/1 and K-3/2 stripping.

The required qualitative characteristics of the straight-run fraction of diesel summer fuel (flash point over 55 ° C) ensure that the pressure in the K-2 column is 0.3-0.4 ati, and the cloud point of this fraction (no higher than minus 3 ° C) is achieved by maintaining the temperature at The 15th plate of the K-2 column - 287-291 ° C.

Further, the obtained straight-run fractions of diesel winter and summer diesel fuel are fed to a two-unit diesel hydrotreatment unit. On the first block (15), the straight run winter diesel fuel fraction is subjected to hydrotreating (13), and on the second block (16), the straight run summer diesel fuel fraction is subjected to hydrotreatment (14). The process is conducted on alumina-cobalt-molybdenum or aluminum-nickel-molybdenum hydrotreating catalysts until the required quality value for sulfur content is obtained: not higher than 10 ppm or 50 ppm, depending on the environmental level of the diesel fuel produced. The result of the hydrotreatment process is to achieve a sulfur content in the fuel of not more than 50 ppm.

Ensuring a stable quality parameter - flash point of commercial diesel fuel (more than 55 ° C) is carried out in two stages, first on the AVT installation by producing a component with a boiling point of at least 159 ° C, and then by removing light hydrocarbon fractions from hydrotreated straight-run fractions of diesel fuel on the stabilization units of hydrotreatment plants. The stabilization process is carried out with the following technological parameters: the top temperature of the stabilization column is maintained at 150-155 ° C, the pressure in the column is 0.9-1.1 ati.

Further obtained after stabilization of the fraction: hydrotreated straight-run fraction of winter diesel fuel (17) is mixed with hydrotreated straight-run fraction of summer diesel fuel (18) in a ratio of 97-60: 3-40% wt. respectively.

The choice of ratio when composing fractions is carried out depending on the required cloud point of commercial diesel winter fuel. European standards require the production of diesel fuels with a cloud point of minus 10 ° C, minus 16 ° C, minus 22 ° C, minus 28 ° C and minus 34 ° C.

In the obtained base fuel with a cloud point from minus 10 ° C to minus 34 ° C, a depressant-dispersing additive (19) is introduced in an amount of up to 150 ppm. Depressor-dispersant additives are introduced to improve the low-temperature properties of fuels (pour point and limiting filterability temperature). Depressor-dispersant additives are a complex compound of a depressant (MDFI complex) - acting as a diluent for kerosene, and a dispersant (WASA complex) - exhibiting the properties of paraffin dispersants, and in terms of chemical composition they are solutions of high molecular weight compounds in organic solvents. As a rule, these are complex compositions based on EVA (ethylene vinyl acetate copolymer) and / or terpolymers (obtained by copolymerization of 3 different monomers, for example, olefins, acrylates, fatty amides, vinyl ethers and esters, and many others) .

Examples of execution.

Example 1. Technological parameters - table 1, quality parameters - table 2.

Raw materials - crude oil after passing through dehydration and desalination at the ELOU-1 installation, is fed to the K-1 topping column of the AT-4 installation (atmospheric distillation with double evaporation). From the top of the K-1 column, gasoline is removed, from the bottom - partially stripped oil, which, after heating, is fed to the main distillation column K-2. The K-2 column has 42 plates, the third circulation irrigation is supplied from 12 to 14 plates, from 15 plates diesel fuel is taken to the K-3/3 stripping column, the second circulation irrigation is fed from 22 to 24 plates, overflow from 25 plates diesel fuel to the K-3/2 stripping column, the first circulation irrigation is supplied from 32 to 34 plates, from the 35 plate the fraction of straight-run jet fuel is transferred to the K-3/1 stripping column, gasoline is taken from the top of the K-2 column , irrigation is fed to the upper 42nd tar Christmas tree. The winter straight-run diesel fuel fraction is obtained by mixing the K-3/1 stream with part of the K-3/2 stream in a ratio of 45:55. The summer straight-run diesel fuel fraction is obtained by mixing the flow from K-3/3 with the remaining amount of flow from K-3/2. The beginning of the boiling fraction of straight run winter diesel fuel is at least 159 ° C and the content of fractions boiling up to 180 ° C is not more than 10% wt. provide temperature maintenance:

- top of the column - 140 ° C;

- on the thirty-fifth plate - 166 ° C;

- entry into the column - 360 ° C,

and also maintain pressure in the column - 0.35 ati.

The required density values of straight run winter diesel fuel - 800-815 kg / m ³ provide the specified ratio of the involvement of flows of stripping columns K-3/1 and K-3/2. The required flash point of straight-run summer diesel fuel is provided by the pressure in the K-2 column - 0.35 ati, the cloud point - by the temperature on the 15th plate - 289 ° С.

Then, winter and summer straight run diesel fuel fractions are fed to a two-unit hydrotreating unit. On the first block, hydrotreating the fraction of straight run diesel fuel for the winter is carried out, on the second block, hydrotreating the fraction of straight run diesel fuel for the summer until a sulfur content of not more than 50 ppm is achieved.

Next, the obtained hydrotreated straight-run fractions of diesel fuels of summer and winter type are fed to the stabilization unit. The temperature of the top of the stabilization column is 155 ° C, the pressure is 0.9 ati. Such technological parameters of the column provide components with a flash point above 55 ° C.

Further, after stabilization of hydrotreated straight-run fractions of winter and summer diesel fuels, basic diesel fuel is obtained by compounding fractions in the following ratio of components of 60: 40% wt. respectively. Then, 100 ppm of Clariant Dodiflow 4965 depressant-dispersant additive is additionally introduced, which in terms of chemical composition is a mixture of polymers in high-boiling hydrocarbons and additionally contains 10-20% wt. Petroleum hydrocarbonate. and has the following characteristics.

Appearance: viscous brown liquid.

Density: approx. 0.960 g / cm ³ at 40 ° C (DIN 51757).

Viscosity: approx. 1,150 mm ² / s at 40 ° C (DIN 51562).

Hardening temperature: -3-45 ° С (DIN ISO 3016).

Flash point: approx. 62 ° C (DIN EN 22719 / ISO 2719).

(The given physicochemical properties are the data of the safety data sheet of the substance in accordance with Directive (EU) No. 453/2010).

Example 2. The data on the implementation of example 2 are shown in table 1 (technological parameters) and table 3 (quality parameters). Further, 150 ppm of Clariant Dodiflow 4965 depressant-dispersant additive is further added.

Example 3. The data on the implementation of example 3 are shown in table 1 (technological parameters) and table 4 (quality parameters). Further, 100 ppm of Clariant Dodiflow 4965 depressant-dispersant additive is further added.

Example 4. The data on the implementation of example 4 are shown in table 1 (technological parameters) and table 5 (quality parameters). In this case, 150 ppm of the Infineum R-442 depressant-dispersant additive, which is a mixture of polymers in high boiling hydrocarbons with the following characteristics, is additionally introduced into the base fuel.

Appearance: brown liquid.

Density: approx. 0.918 g / cm ³ at 40 ° C (ASTM D 4052).

Viscosity: approx. 295 mm ² / s at 40 ° C (ASTM D 4052).

Pour point: approx. + 21 ° C (ASTM D 93B).

Flash point: min. 62 ° C (ASTM D 4052).

Example 5. The data on the implementation of example 5 are shown in table 1 (technological parameters) and table 6 (quality parameters). At the same time, 150 ppm of the BASF company Keroflux 3501 depressant-dispersant additive, which is a mixture of olefin derivatives and fatty acid amides in an organic solvent with the following characteristics, is additionally introduced into the base fuel.

Appearance: tan opaque liquid.

Density: approx. 0.910 g / cm ³ at 20 ° C (DIN 51757).

Viscosity: approx. 32 mm ² / s at 50 ° C (DIN 51562).

Pour point: approx. + 9 ° C (ISO 3016).

Flash point: above 57 ° C (ISO 2719).

Thus, the implementation of the method of producing winter diesel fuel EURO according to the invention with a minimum set of technological processes: primary distillation of oil, separation of fractions in a certain way, hydrotreating and stabilization of hydrotreated straight-run fractions of diesel fuels, compounding them in predetermined ratios allows to obtain fuel that meets European quality standards winter diesel fuel while minimizing the involvement of a depressant-dispersant additive. Moreover, the resulting composition does not require the involvement of a cetane enhancing additive, which in turn allows limiting the involvement of a lubricating additive, since these additives are antagonists. The proposed technology is economically more feasible than existing technologies that are compared with it.

Table 1 The technological parameters of the main distillation column K-2 installation AT Name of indicator Units rev. Example 1 Example 2 Example 3 Example 4 Example 5 K-2 column Top Pressure K-2 ati 0.350 0.355 0.398 0.390 0.391 Top temperature K-2 ° C 140 139 140 141 140 Temperature 34 tar. ° C - 187 187 188 188 Temperature 24 tars ° C - 241 241 240 241 Temperature 14 tar. ° C - 304 304 303 304 Temperature 35 tar. ° C 166 166 166 166 166 Temperature 25 tar. ° C 233 233 233 234 223 Temperature 15 tar. ° C 289 289 289 288 288 The temperature of the cube K-2 ° C 338 340 339 340 340 Acute irrigation consumption m ³ / hour 40 39 41 40 40 Consumption 1 tsp m ³ / hour 188 186 188 188 188 Consumption 2 tsp m ³ / hour 147 147 146 146 146 Consumption 3 tsp m ³ / hour 159 175 169 169 169 Temperature 1 tsp ° C 190/68 190/69 191/71 191/71 191/71 The temperature of the entrance to K-2 2 ts.o. ° C 156 155 156 157 156 The temperature of the entrance to K-2 3 ts.o. ° C 141 147 146 146 147 K-2 gasoline consumption m ³ / hour 37 36 37 36 37 The flow rate of the fraction 140-240 ° C with K 3/1 m ³ / hour 59,4 58 61 61 61 with temperature ° C 154 153 154 155 154 at the exit from the installation kg / hour 32721 31566 34126 34126 34126 The consumption of the fraction 240-300 ° C m ³ / hour 124 127 129 129 129 with temperature ° C 226 225 226 226 226 VDTZ t / h 39 40 fifty fifty fifty The consumption of the fraction 300-350 ° C m ³ / hour 92 93 94 93 94 with temperature ° C 282 282 281 281 281 Total output K-3/2 + K-3/3 (DTL) t / h 121 118 110 111 110 Supply temperature ° C 360 360 360 360 360 Steam consumption in K-2 kg / hour 3782 3799 3793 3793 3793 Steam consumption in K 3/1 kg / hour 121 127 106 107 106 Fuel oil consumption m ³ / hour 205 206 218 218 219 m ³ / hour 205 202 199 199 199

Claims (1)

A method of producing EURO winter diesel fuel from sulfur oils by primary distillation of oil, hydrotreating, compounding fractions, the introduction of additives, characterized in that the crude oil after desalting and dehydration is fed to the topping column, where gasoline is removed from the top of the column during fractionation from the bottom of the column partially stripped oil is withdrawn, which is fed to the K-2 main fractionation column, from where straight distillates are removed to K-3/1, K-3/2, K-3/3 stripping columns and then by mixing the stream from the stripper K-3/1 with the balance quantity of flow from the stripper K-3/2 is obtained winter diesel fuel fraction, characterized by an initial boiling point not lower than 159 ° C, a density of 800-815 kg / m ³ and containing therein fractions boiling up to 180 ° C, not more than 10 wt.%, and by mixing the stream from the K-3/3 stripping column with the remaining part of the stream from the K-3/2 stripping column, a diesel summer fuel fraction with a flash point of more than 55 ° С and cloud point no higher than minus 3 ° С, then separate hydrotreatment is carried out of straight-run diesel fuel fractions with subsequent additional removal of light hydrocarbon fractions from the hydrotreatment units to the stabilization units, the base fuel is obtained by compounding the hydrotreated straight run diesel fuel fractions of winter and diesel summer fuel at a ratio of 97-60: 3-40 wt.%, respectively, and additionally introduced into the obtained base fuel depressant-dispersant additive in an amount of not more than 150 million ^-1.

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