RU2708621C1 - Method of producing high-octane gasoline fractions and aromatic hydrocarbons - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: method of producing high-octane gasoline fractions and aromatic hydrocarbons C₆-C₁₀ from hydrocarbon raw materials boiling in the boiling point range of gasoline-naphtha fractions by heating, evaporation and overheating to processing temperature, its further contact at temperature of 320–480 °C and increased pressure with periodically regenerated catalyst containing ZSM-5 or ZSM-11 zeolite, cooling and partial condensation of contact products, their dividing by separation and rectification in a stabilization column with extraction of hydrocarbon gases fraction(s) on top of this column and stable gasoline fraction column bottom, rectification of liquid fraction in rectification column with extraction of liquid distillate by column top and heavy residue fraction column bottom, where separation of contact products is carried out at temperature of 150–220 °C or at temperature providing content of molar fraction of liquid in contact products equal to 0.05–0.25, recovered at separation stage of contact products liquid fraction is supplied to rectification column, rectification column distillate is fed into stabilization column together with steam-gas fraction obtained during separation of contact products with further extraction of target product by stabilizer column bottom.

EFFECT: reduced power consumption – amount of heat and coolant required for separation of reaction products.

3 cl, 5 ex

Description

The invention relates to methods for producing high octane gasoline fractions and C ₆ -C ₁₀ aromatic hydrocarbons from hydrocarbon feedstocks boiling in the boiling point range using zeolite-containing catalysts and can be used in the oil and gas refining industries.

High-octane gasoline fractions are usually obtained from hydrocarbon raw materials boiling in the boiling point range of gasoline-naphtha fractions by isomerization and catalytic reforming processes, which impose stringent requirements on the quality of the raw materials [Gureev AA, Zhorov Yu.M., Smidovich EV. High octane gasoline production. - M, - Chemistry, 1981, - 224 p.]. At present, new processes and zeolite-containing catalysts are being developed for them, which make it possible to process hydrocarbon raw materials of a wide fractional composition (from hydrocarbons C ₅ to C ₁₂ and higher) into high-octane gasolines in one stage. As the active component of the catalyst, zeolite ZSM-5 (structural type MFI) or ZSM-11 (structural type MEL) is most often used; possibly the use of zeolites modified by elements of groups I-VIII.

So, for example, there are known methods for producing high-octane gasoline fractions and / or aromatic hydrocarbons C ₆ -C ₁₀ [US Pat. US No. 5961818, 1999; Pat. RF №2372988, 2009; Pat. RF No 2417249, 2011; Pat. RF No 2518481, 2013; Pat. RF №2658832, 2018] and many of their other analogues. According to these methods, high-octane gasoline fractions are obtained from C ₂ -C ₁₂ hydrocarbons by contacting the feed in the temperature range of 200-650 ° C and pressures of 0.1-6.0 MPa with zeolite-containing catalysts and subsequent isolation of the target product. General disadvantages of the above methods and their analogues are the relatively low yields of the resulting gasoline fractions.

A known installation and method of processing a mixture of hydrocarbons C ₁ -C _{10 of} various compositions and oxygen-containing compounds [US Pat. RF №2671568, 2018]. According to this method, said raw materials are processed into high-octane gasoline as follows. The flows of hydrocarbon feedstocks and oxygen-containing compounds are mixed, heated to the processing temperature, and fed to one of two or more reactors operating alternately in the reaction-regeneration cycle. Processing of raw materials at the reaction stage is carried out in the presence of catalysts based on zeolites of the pentasil group (zeolites ZSM-5, ZSM-11) at a temperature of 250-600 ° C, a pressure of 0.1-10.0 MPa, a volumetric feed rate of liquid feedstock 0 1-10 h ^-1 . The reaction products are cooled and separated in a three-phase separator with the release of the aqueous phase, hydrocarbon gases and liquid unstable hydrocarbon catalysis. Unstable catalyzate is separated in a distillation column to obtain a hydrocarbon gas fraction, liquefied petroleum gas and a column column — a stable high-octane gasoline fraction or aromatic hydrocarbon concentrate — on top of the column. The main disadvantage of this method is the inability to control the temperature of the end of the boiling gasoline produced, because when processing raw materials in the high-octane gasoline production mode, the product selected by the distillation column cube will have a higher boiling point than modern standards require.

The drawback described above lacks methods in which the separation of reaction products is carried out according to a two-column scheme, for example, such as plants and methods for producing high-octane gasoline fractions and / or aromatic hydrocarbons [US Pat. RF No. 2053013, 1996; Pat. RF №2098173, 1997], differing in the design of the reactor units. According to these methods, the used catalytic plants, depending on the type of feedstock, may not contain, but may contain from 1 to 4 distillation columns for the separation of raw materials, including to isolate fractions of the feed for the catalytic process. The production of high-octane gasoline fractions at these plants is carried out by feeding the catalytic process feed to the reactor blocks with a loaded catalyst containing zeolite ZSM-5 or ZSM-11, alternately operating in the reaction – regeneration cycle. The processing of raw materials on the catalyst is carried out at elevated temperature and overpressure. The reaction products leaving the reactor blocks are cooled and separated in a separator with the release of hydrocarbon gases and liquid unstable hydrocarbon catalysis, and in the case of processing oxygen-containing compounds, and the aqueous phase. After the separator, unstable catalysis is fed to a distillation stabilizer column with the release of a hydrocarbon gas fraction, possibly liquefied petroleum gas, from the top of the column, and a column of a stable gasoline fraction with the required saturated vapor pressure. The isolated stable gasoline fraction is then fed to the second product distillation column, on top of which the target product is selected - a high-octane gasoline fraction with the necessary boiling points of 90% vol. and the end of boiling, and the cube of the column is a hydrocarbon fraction boiling off at temperatures above the boiling points of gasoline. Common disadvantages of these methods are the relatively low yields of the resulting gasoline fractions.

The closest in its technical essence and the achieved effect is a method for producing high-octane gasoline fractions and aromatic hydrocarbons [Pat. RF №2334781, 2008]. According to the selected prototype, the production of high-octane gasoline fractions and aromatic hydrocarbons C ₆ -C ₁₀ from hydrocarbon feeds is carried out as follows.

The raw materials are heated to the processing temperature in the corresponding technological apparatuses and in one or several reactors at a pressure of 0.4-4.0 MPa, a temperature of 320-480 ° C and a mass feed rate of up to 10 h ^{-1, they} are contacted with a periodically regenerated catalyst, containing zeolite ZSM-5 or ZSM-11. The catalyst may be modified by elements of groups I-VIII or their compounds. The reaction products are cooled in appropriate technological apparatuses to a temperature of 45-140 ° C and subjected to separation with the release of a gaseous and liquid fraction. The liquid fraction separated in the separator is sent to the feed section of the distillation column-stabilizer, and the gaseous fraction after the separator is fed to the same stabilization column, in the intermediate section between the power input and the cold irrigation input. On top of the stabilization column operating under elevated pressure, a light fraction is taken, which is cooled and separated in a suitable technological equipment with the release of C ₁ -C ₄ hydrocarbon gases and liquid distillate, which is returned to the column in the form of cold irrigation, possibly producing liquefied C ₃ gas -C ₄ . Stable catalyzate is taken up by columns, part of which is heated in the appropriate technological equipment to operating temperature and returned to the column to maintain the heat balance of the column, and the balance part of the bottom product is fed (possibly with additional heating) to a second distillation column operating at a slight excess pressure. In the second distillation column, stable catalysis is separated, with the top of the column being separated out - the high-octane gasoline fraction or the C ₆ -C ₁₀ aromatic hydrocarbon fraction and the bottom of the column - the residual fraction boiling above the gasoline boiling point (above 185-205 ° С).

According to the prototype, the catalyst regeneration stage is carried out at a temperature of 350-550 ° C and a pressure of 0.1-4.0 MPa with an initially regenerating gas with an oxygen content of 0.1-5% vol., And then with an oxygen content of 7-21% vol. It is possible to obtain a regenerating gas by mixing part of the exhaust regeneration gases with air or with air and nitrogen.

The main disadvantage of the above methods and prototype are increased energy costs - the amount of heat and refrigerant needed to separate the reaction products.

The problem solved by the present invention is to reduce energy consumption - the amount of heat and refrigerant needed to separate the reaction products.

The problem is solved in that the production of high-octane gasoline fractions and C ₆ -C ₁₀ aromatic hydrocarbons from hydrocarbon feedstocks boiling in the boiling point range is carried out by heating, evaporating and overheating to the processing temperature, its subsequent contacting at a temperature of 320-480 ° С and increased pressure with a periodically regenerated catalyst containing zeolite ZSM-5 or ZSM-11, cooling and partial condensation of the contact products, their separation by sep cations at a temperature of 150-220 ° C or at a temperature providing a content of a molar fraction of liquid in the contact products equal to 0.05-0.25, feeding the liquid fraction separated at the stage of separation of the contact products of contacting into the distillation column and highlighting the liquid distillate on top of this column and cube of the column of the heavy residue fraction, feeding the distillate of the distillation column together with the vapor-gas fraction obtained by separation of the contact products into the stabilization column and highlighting the fraction of the top (c d) hydrocarbon gases and bottom of the column stable gasoline fraction to afford the desired product.

The problem is solved in the same way that the stage of contacting the feedstock with the catalyst is carried out at a pressure of 1-3 MPa.

The problem is solved in the same way that the catalyst contains a ferroaluminosilicate with a zeolite structure of ZSM-5 (MFI) or ZSM-11 (MEL).

The main distinguishing feature of the proposed method is the separation of the contact products at a temperature of 150-220 ° C or at a temperature that provides a mole fraction of the liquid in the contact products equal to 0.05-0.25, feeding the liquid fraction extracted at the stage of separation of the contact products to the distillation column and feeding the distillate of the distillation column together with the vapor-gas fraction obtained by separation of the contact products into the stabilization column to obtain the target product.

The main advantage of the proposed method is reduced energy consumption - the amount of heat and refrigerant needed to separate the reaction products.

The achieved result is due to the fact that the cooling of the reaction products before their separation is carried out not to a minimum temperature - usually to a temperature of 25-45 ° C, which ensures maximum condensation of hydrocarbons, or as in the prototype to a temperature of 100-140 ° C, but to a higher temperature - up to 150-220 ° C, which leads to a decrease in the amount of required refrigerant. The decrease in the amount of heat required for the separation of reaction products, to a greater extent to provide heat for the distillation process in the distillation column, is due to the fact that the material load on the distillation column is significantly reduced.

In addition, the advantage of the proposed method is to reduce the material load on the distillation column, which entails a decrease in the inner diameter of the column used, and as a result, a decrease in its metal consumption.

This result is due to the fact that the cooling of the reaction products before their separation is carried out to a temperature of 150-220 ° C, which ensures the formation of a molar fraction of liquid in the shared mixture equal to 0.05-0.25%, as a result of which the liquid fraction released during separation does not contains significant amounts of dissolved gases, which does not require their isolation, i.e. its stabilization of this fraction, and the vapor-gas fraction released during separation practically does not contain heavy hydrocarbons boiling above 200 ° С, which does not require its subsequent rectification.

The method is as follows. The raw materials are heated to the processing temperature in the corresponding technological devices (heat exchangers, furnaces, etc.) and fed to the reactor or to several reactors, where at a temperature of 320-480 ° C, overpressure (preferably 1.2-3.0 MPa, and even better - 1.6-2.4 MPa) and a mass feed rate of 1-6 h ^{-1 is} subjected to contact with a periodically regenerated zeolite-containing catalyst. A gradual increase in reaction temperature is possible during the process. As a catalyst, systems containing zeolite or ferroaluminosilicate with a structure of ZSM-5 or ZSM-11 (structural type MFI and MEL, respectively) are used, including modified by elements of groups I-VIII or their compounds. Catalysts are prepared by known methods.

The reaction products (contacting products) are cooled in appropriate technological devices (recuperative heat exchangers, refrigerators) to a temperature of 150-220 ° C or to a temperature that provides a mole fraction of liquid in the contacting products equal to 0.05-0.25, and at this temperature subjected to separation with the release of gas-vapor and liquid fractions.

The liquid fraction recovered during separation of the contacting products after depressurization is fed, possibly with additional heating, to a distillation column operating at atmospheric or slight overpressure. In the distillation column, the fed fraction is separated with the distillate (gasoline fraction) on top of the column being separated, and the cube of the column - a heavy residual fraction of aromatic hydrocarbons boiling above the boiling point of gasoline, which is a by-product.

The distillate of the distillation column is mixed with the vapor-gas fraction extracted during separation of the contacting products and fed to a stabilization column operating at elevated pressure (preferably 1.2-2.4 MPa). Partial cooling of the column raw material to the optimum temperature is possible, which depends on the nutritional composition of the column and its operating conditions.

A light fraction is taken from the top of the stabilization column, which is cooled and separated in appropriate technological equipment with the release of C ₁ -C ₄ hydrocarbon gases and liquid distillate, which is returned to the column in the form of cold irrigation, possibly with the release of liquefied C ₃ -C ₄ gas as a concomitant product, possibly in the form of liquefied petroleum gas brands SPBT, PBT or PBA. A stable gasoline fraction is selected by the cube of the stabilization column, part of which is heated in the appropriate technological equipment (furnace, boiler, etc.) to the operating temperature and returned to the stabilizer column to maintain the thermal balance of the column. After cooling, the balance part of the bottoms product is withdrawn as the target product — the high-octane gasoline fraction and / or the C ₆ -C ₁₀ aromatic hydrocarbon fraction.

Periodically, as described in the prototype, carry out the regeneration of the catalyst.

The essence of the proposed method and its practical applicability is illustrated by the following examples. Example 1 is similar to the prototype and is shown for comparison with the proposed method in similar conditions with examples 2 and 3, examples 4 and 5 are given to further illustrate the implementation of the proposed method.

Example 1 (similar to the prototype).

As raw materials, a straight-run gasoline fraction of oil with an octane number of OCH = 62 MM containing hydrocarbons is used,% wt .: C ₃ - 0.1; C ₄ to 3.9; C ₅ to 10.2; C ₆ - 19.7; C ₇ - 26.1; C ₈ to 20.7; C. ₉ - 11.1; With ₁₀₊ - 8.2, including n-paraffins - 29.8, isoparaffins - 32.7, naphthenes - 28.2, aromatic -9.3.

Raw materials, in an amount of 10 t / h, having a temperature of 45 ° C, are heated, pressurized, overheated to a processing temperature under excess pressure, spending a total amount of heat of 10217 MJ / h, and at a temperature of 350 ° C, pressure 1.5 MPa and the mass feed rate of 1.5 h ^{-1 is} subjected to contact with a periodically regenerated catalyst containing 30% wt. Al ₂ O ₃ and 70% zeolite ZSM-5 (MFI), modified with 0.2% La.

The reaction products (contacting products) are cooled from a temperature of 350 ° C to 100 ° C; the cooling costs of 10 t / h of the product stream are 8117 MJ / h, and at a pressure of 1.41 MPa, they are separated with the release of 7.23 t / h of the liquid fraction and 2.77 t / h of the gas-vapor fraction.

The liquid fraction isolated during separation of the contacting products is heated to a temperature of 120 ° C, while consuming heat in the amount of 469 MJ / h, and is fed to a distillation stabilizer column equipped with a reflux condenser and a boiler, and the gaseous fraction is fed to the same column, in the intermediate section between the power input and the input of cold irrigation.

The stabilization column has 16 theoretical plates, a power plate - 8, a gas phase input plate - 5, a reflux ratio - 1.5; the pressure at the top of the column is 1.33 MPa, the temperature of the top of the column is 55 ° C, the cube is 153 ° C, irrigation is 42 ° C, steam from the boiler is 186 ° C. To ensure the rectification process in the stabilizer column, 2694 MJ / h are spent on heat supply to the boiler boiler and 2010 MJ / h on cooling the distillate in the column reflux condenser.

From the reflux condenser of the stabilizer column, 3.35 t / h (33.5% by weight of raw materials) of a C ₁ -C ₄ hydrocarbon gas fraction, which is a by-product, are taken. 6.65 t / h of stable catalysis — a stable gasoline fraction — are taken up by column cube. After depressurization to 0.25 MPa, stable catalyzate is heated from a temperature of 132 ° C to 200 ° C, spending at the same time heat in an amount of 2063 MJ / h, and is fed to a distillation column equipped with a condenser and a boiler as power.

The distillation column has 14 theoretical plates, the power plate - 7, the reflux ratio - 1.0; the pressure at the top of the column is 0.15 MPa, the top temperature of the column is 140 ° C, the cube is 258 ° C, the irrigation is 64 ° C, the steam from the boiler is 272 ° C. To ensure the distillation process in a distillation column, 2282 MJ / h are spent on heat supply to the boiler boiler and 6174 MJ / h on cooling the distillate in the column reflux condenser.

In a distillation column, the maximum vapor load falls on 3 theoretical plates and amounts to 2930 m ³ / h; with a calculated density on the plate of steam of 4.79 kg / m ³ and a liquid of 713.4 kg / m ³ for an interblock distance of 600 mm, the maximum allowable steam speed is 0.72 m / s, which requires the use of a column with an inner diameter of 1200 mm

At the top of the distillation column, 6.43 t / h (64.3% wt.) Of distillate, the gasoline fraction, which is the target product, is taken to cool it down to a temperature of 45 ° C and 251 MJ / h are spent. 0.22 t / h (2.2%) of the heavy fraction of aromatic hydrocarbons boiling above 200 ° C and being a by-product, which 118 MJ / h are spent on cooling to the column, are selected by cube columns.

The resulting gasoline fraction has a saturated vapor pressure of 76 kPa, contains 7.4% wt. hydrocarbons C ₃ -C ₄ , 6.0% n-paraffins C ₅₊ , 42.5% isoparaffins and naphthenes C ₅₊ and 44.1% aromatic hydrocarbons C ₆ -C ₁₀ , and corresponds to winter high-octane gasoline Premium-95 with evaporation class D.

In general, in the processing of 10 t / h of raw materials, the necessary total costs of heat and refrigerant for the separation of reaction products are:

- the amount of heat supplied to the rectification during the separation of the reaction products (heating the columns and heating the boilers of the columns) - 7508 MJ / h;

- the amount of heat removed to cool all streams (including cooling the reaction products) - 16670 MJ / h.

Example 2

As raw materials, a straight-run gasoline fraction of oil with an octane number of OCH = 62 MM containing hydrocarbons is used,% wt .: C ₃ - 0.1; C ₄ to 3.9; C ₅ to 10.2; C ₆ - 19.7; C ₇ - 26.1; C ₈ to 20.7; C. ₉ - 11.1; With ₁₀₊ - 8.2, including n-paraffins - 29.8, isoparaffins - 32.7, naphthenes - 28.2, aromatic - 9.3.

Raw materials, in an amount of 10 t / h, having a temperature of 45 ° C under excessive pressure are heated, evaporated, overheated to a processing temperature, spending a total amount of heat of 10217 MJ / h, and at a temperature of 350 ° C, pressure 1.5 MPa and the mass feed rate of 1.5 h ^{-1 is} subjected to contact with a periodically regenerated catalyst containing 30% wt. Al ₂ O ₃ and 70% zeolite ZSM-5 (MFI), modified with 0.2% La.

The reaction products (contacting products) are cooled from a temperature of 350 ° C to 190 ° C, providing a molar fraction of liquid in the mixture equal to 0.07. The cost of cooling 10 t / h of the reaction product stream is 4402 MJ / h. Cooled to 190 ° C, the product stream at a pressure of 1.41 MPa is subjected to separation with the release of 1.18 t / h of the liquid fraction and 8.82 t / h of the gas-vapor fraction.

After discharge, the liquid fraction separated during contact product separation is heated to 0.25 MPa from a temperature of 155 ° C to 200 ° C, while consuming heat in the amount of 347 MJ / h, and is fed to a distillation column equipped with a condenser and a boiler.

The distillation column has 14 theoretical plates, the power plate - 7, the reflux ratio - 1.0; the pressure at the top of the column is 0.15 MPa, the temperature of the top of the column is 155 ° C, the cube is 241 ° C, irrigation is 41 ° C, steam from the boiler is 256 ° C. To ensure the distillation process in the column, 435 MJ / h are spent on heat supply to the column boiler and 1063 MJ / h on cooling the distillate in the column reflux condenser. 108 MJ / h are spent on cooling the bottoms product of the column to 45 ° C.

In a distillation column, the maximum vapor load falls on 3 theoretical plates and amounts to 480 m ³ / h; with a calculated density on the plate of steam of 5.02 kg / m ³ and liquid of 705.8 kg / m ³ for an inter-plate distance of 600 mm, the maximum allowable steam speed is 0.7 m / s, which requires the use of a column with an inner diameter of 500 mm

0.96 t / h of distillate-gasoline fraction having a saturated vapor pressure of 109 kPa (at 38 ° C) and containing 56% wt. aromatic hydrocarbons C ₆ -C ₁₀ . 0.22 t / h (2.2% by weight of raw materials) of a heavy fraction of aromatic hydrocarbons boiling above 200 ° C and being a by-product are selected by cube distillation columns.

The distillation of the distillation column is mixed with the vapor-gas fraction extracted during the separation of reaction products, the resulting mixture is cooled from 181 ° С to 110 ° С, spending 2926 MJ / h, and fed to a distillation stabilizer column equipped with a reflux condenser and a boiler .

The stabilization column has 16 theoretical plates, the power plate - 8 reflux ratio - 1.5; the pressure at the top of the column is 1.33 MPa, the temperature of the top of the column is 54 ° C, the cube is 150 ° C, irrigation is 42 ° C, steam from the boiler is 182 ° C. To ensure the rectification process in the stabilizer column, 2573 MJ / h are spent on heat supply to the column boiler and 1965 MJ / h on cooling the distillate in the column reflux condenser.

From the reflux condenser of the stabilizer column, 3.29 t / h (32.9% by weight) of C ₁ -C ₄ hydrocarbon gas fractions, which are a by-product, are taken. 6.48 t / h (64.8%) of a stable high-octane gasoline fraction, which is the target product, which is cooled to a temperature of 45 ° C, while removing heat in an amount of 1736 MJ / h, is selected by column cube.

The resulting gasoline fraction has a saturated vapor pressure of 75 kPa, contains 8.1% wt. hydrocarbons C ₃ -C ₄ , 6.0% n-paraffins C ₅₊ , 41.8% isoparaffins and naphthenes C ₅₊ and 44.1% aromatic hydrocarbons C ₆ -C ₁₀ , and corresponds to premium-95 high-octane gasoline with class volatility C.

In general, in the processing of 10 t / h of raw materials, the necessary total costs of heat and refrigerant for the separation of reaction products are:

- the amount of heat supplied to the rectification during the separation of the reaction products (heating the columns and heating the boilers of the columns) - 3355 MJ / h;

- the amount of heat removed to cool all flows (including cooling the reaction products) - 12544 MJ / h.

Example 3

Similar to example 2 with the difference that the separation of the contacting products is carried out at a temperature of 175 ° C, providing a molar fraction of liquid in the mixture, equal to 0.16, with the release of 2.42 t / h of the liquid fraction and 7.58 t / h of vapor-gas fraction. Moreover, the cost of cooling the reaction products is 5077 MJ / h.

In the distillation column, 0.04 t / h (0.4% wt.) Of the fraction of C ₂ -C ₄ hydrocarbon gases, 0.22 t / h (2.2%) of the heavy fraction of aromatic hydrocarbons, which are by-products, and 2 , 16 t / h of distillate - a high-octane gasoline fraction having a saturated vapor pressure of 105 kPa (at 38 ° C) and containing 55% wt. aromatic hydrocarbons C ₆ -C ₁₀ . At the same time, the column operates with the following parameters: pressure at the top - 0.15 MPa, top temperature - 155 ° C, cube - 252 ° C, irrigation - 45 ° C, steam from the boiler - 268 ° C. The cost of heat for the separation of products in a distillation column is:

- amount of heat input - 1837 MJ / h; including heating the column feed stream from a temperature of 142 ° C to 200 ° C - 840 MJ / h, for heating a boiler - 997 MJ / h;

- the amount of heat removed - 2526 MJ / h; including when cooling the reflux condenser - 2411 MJ / h, cooling of the heavy residue fraction - 115 MJ / h.

In a distillation column, the maximum vapor load falls on 3 theoretical plates and amounts to 1107 m ³ / h; with a calculated density on the plate of steam of 4.94 kg / m ³ and a liquid of 706 kg / m ³ for an interblock distance of 600 mm, the maximum allowable steam speed is 0.71 m / s, which requires the use of a column with an inner diameter of 800 mm.

In the stabilization column, 3.27 t / h (32.7% wt.) Of the C ₁ -C ₄ hydrocarbon gas fraction, which is a by-product, and 6.47 t / h (64.7%) of the stable high-octane gasoline fraction, which is target product. At the same time, the column operates with the following parameters: pressure at the top - 1.33 MPa, top temperature - 54 ° C, cube - 150 ° C, irrigation - 41 ° C, steam from the boiler - 182 ° C. The cost of heat for the separation of products in the stabilization column is:

- the amount of heat supplied to the boiler - 2558 MJ / h;

- the amount of heat removed - 5394 MJ / h; including when cooling the feed stream of the column - 1958 MJ / h, when cooling the reflux condenser - 1953 MJ / h; when cooling the stable gasoline fraction to a temperature of 45 ° C - 2078 MJ / h.

The resulting gasoline fraction has a saturated vapor pressure of 75 kPa, contains 8.1% wt. hydrocarbons C ₃ -C ₄ , 6.0% n-paraffins C ₅₊ , 41.8% isoparaffins and naphthenes C ₅₊ and 44.1% aromatic hydrocarbons C ₆ -C ₁₀ , and corresponds to premium-95 high-octane gasoline with class volatility C.

In general, in the processing of 10 t / h of raw materials, the necessary total costs of heat and refrigerant for the separation of reaction products are:

- the amount of heat supplied to the rectification during the separation of the reaction products (heating the power of the columns and heating the boilers of the columns) - 4395 MJ / h;

- the amount of heat removed to cool all streams (including cooling the reaction products) - 13592 MJ / h

Example 4

Similar to example 2. As a raw material, a straight-run gasoline fraction of gas condensate with an octane number of OCH = 66 MM containing hydrocarbons,% wt .: C ₄ - 0.8; C ₅ to 5.7; C ₆ - 16.4; C ₇ - 25.9; C ₈ - 21.0; C. ₉ - 18.4; With ₁₀₊ - 11.8, including n-paraffins - 27.3, isoparaffins - 33.1, naphthenes - 29.7, aromatic - 9.1.

Raw materials, in an amount of 10 t / h, at a temperature of 360 ° C, a pressure of 2.2 MPa and a mass feed rate of 2.0 h ^-1 are contacted with a periodically regenerated catalyst containing 30% wt. Al ₂ O ₃ and 70% ferroaluminosilicate with the structure of zeolite ZSM-5 (MFI). The contacting products are cooled and at a pressure of 1.4 MPa and a temperature of 175 ° C, providing a molar fraction of liquid in the mixture equal to 0.25, subjected to separation with the release of 3.35 t / h of the liquid fraction and 6.65 t / h of gas-vapor fraction.

After discharge, the liquid fraction separated during contact product separation is heated to a temperature of 0.25 MPa and heated to a temperature of 200 ° C and fed to a distillation column operating under the following conditions: top pressure - 0.15 MPa, top temperature - 145 ° C, cube - 234 ° C, irrigation - 42 ° C, steam from the boiler - 243 ° C. In the distillation column, 0.03 t / h (0.3% wt.) Of the C ₂ -C ₄ hydrocarbon gas fraction and 0.2 t / h (2.0% wt.) Of the heavy fraction of aromatic hydrocarbons, which are by-products, are isolated, as well as 3.12 t / h of distillate - a high-octane gasoline fraction having a saturated vapor pressure of 113 kPa (at 38 ° C) and containing 51% wt. aromatic hydrocarbons C ₆ -C ₁₀ .

The distillate of the distillation column is mixed with the vapor-gas fraction extracted during the separation of reaction products, the resulting mixture is cooled to a temperature of 120 ° C and fed as a feed to the distillation stabilizer column. The column operates under the following conditions: pressure at the top - 1.3 MPa, top temperature - 57 ° C, cube - 161 ° C, irrigation - 39 ° C, steam from the boiler - 186 ° C. 1.66 t / h (16.6% by weight) of C ₁ -C ₄ hydrocarbon gas fractions, which are a by-product, of 0.97 t / h (9.7%) of C ₃ -C ₄ liquefied gas, are isolated in the stabilization column as a product - liquefied gas of the SPBT brand, and 7.14 t / h (71.4%) of a stable high-octane gasoline fraction, which is the target product.

The resulting gasoline fraction has a saturated vapor pressure of 63 kPa, contains 5.2% wt. hydrocarbons C ₃ -C ₄ , 8.6% n-paraffins C ₅₊ , 42.3% isoparaffins and naphthenes C ₅₊ and 43.9% aromatic hydrocarbons C ₆ -C ₁₀ , and corresponds to high-octane gasoline Premium-95 summer type with evaporation class A.

Example 5

Similar to example 2. As a raw material using straight-run gasoline fraction of gas condensate, having the following characteristics: density - 742 kg / m ³ ; fractional composition, ° C: n.k. - 35%, 10% vol. - 86, 50% - 116, 90% - 165, c.k. - 192.

Raw materials, in an amount of 10 t / h, at a temperature of 380 ° C, a pressure of 1.6 MPa and a mass feed rate of 2.0 h ^-1 are contacted with a periodically regenerated catalyst containing 35% wt. Al ₂ O ₃ and 65% zeolite ZSM-11 (MEL). The contacting products are cooled and at a pressure of 1.4 MPa and a temperature of 210 ° C, providing a molar fraction of liquid in the mixture equal to 0.10, is subjected to separation with the release of 1.46 t / h of the liquid fraction and 8.54 t / h of the vapor-gas fraction.

After discharge, the liquid fraction separated during contact product separation is heated to 0.25 MPa and heated to a temperature of 200 ° C and fed to a distillation column operating under the following conditions: pressure at the top - 0.15 MPa and temperature at the top - 156 ° C, cube - 234 ° C, irrigation - 36 ° C, steam from the boiler - 243 ° C. In the distillation column, 1.25 t / h (12.5% wt.) Of distillate, a gasoline fraction, having a saturated vapor pressure of 92 kPa (at 38 ° C) and containing 61% wt. aromatic hydrocarbons C ₆ -C ₁₀ , and 0.21 t / h (2.1%) of the heavy fraction of aromatic hydrocarbons, which is a by-product.

The distillate of the distillation column is mixed with the vapor-gas fraction extracted during the separation of reaction products, the resulting mixture is cooled to a temperature of 110 ° C and fed as a feed to the distillation stabilizer column. The column operates under the following conditions: pressure at the top - 1.35 MPa, top temperature - 53 ° C, cube - 161 ° C, irrigation - 39 ° C, steam from the boiler - 194 ° C. 1.16 t / h (11.6% by weight) of C ₁ -C ₄ hydrocarbon gas fractions, which are a by-product of 1.01 t / h (10.1%) of C ₃ -C ₄ liquefied gas, are isolated in the stabilization column the product is SPBT liquefied gas, and 7.61 t / h (71.6%) of a stable high-octane gasoline fraction.

The resulting gasoline fraction has a saturated vapor pressure of 63 kPa, contains 6.3% wt. hydrocarbons C ₃ -C ₄ , 9.4 n-paraffins C ₅₊ , 34.5% isoparaffins and naphthenes C ₅₊ and 49.8% aromatic hydrocarbons C ₆ -C ₁₀ , and is the base gasoline with an octane rating of 86 MM.

As follows from the comparison of example 1 with examples 2 and 3, when processing the same raw material under the same conditions of contacting it with the catalyst and obtaining practically identical product yields, the total amount of heat spent on cooling the streams and ensuring rectification of the products by the proposed method significantly less than the prototype. In addition, the proposed method uses a distillation column of a smaller diameter than the prototype, which significantly reduces its metal consumption.

Claims (3)

1. The method of producing high-octane gasoline fractions and C ₆ -C ₁₀ aromatic hydrocarbons from hydrocarbon feedstocks boiling in the boiling point range is carried out by heating, evaporating and overheating to the processing temperature, its subsequent contacting at a temperature of 320-480 ° C and high pressure with a periodically regenerated catalyst containing zeolite ZSM-5 or ZSM-11, cooling and partial condensation of the contact products, their separation by separation and rectification into a stable the column with the separation of the top of the column fraction (s) of hydrocarbon gases and the bottom of the column stable gasoline fraction, rectification of the liquid fraction in the distillation column with the top of this column of liquid distillate and the bottom of the column fraction of the heavy residue, characterized in that the separation of the contacting products is carried out at a temperature 150-220 ° C or at a temperature providing the content of the molar fraction of liquid in the contact products equal to 0.05-0.25, allocated at the stage of separation of contact products The liquid fraction is fed to the distillation column, the distillate of the distillation column is fed to the stabilization column together with the vapor-gas fraction obtained by separation of the contacting products, followed by the isolation of the target product by the cube of the stabilization column. 2. The method according to p. 1, characterized in that the stage of contacting the feedstock with the catalyst is carried out at a pressure of 1-3 MPa. 3. The method according to p. 1 or 2, characterized in that the catalyst contains a ferroaluminosilicate with a structure of ZSM-5 (MFI) or ZSM-11 (MEL).