RU2814255C1 - Method of producing ethylene and propylene - Google Patents

Abstract

FIELD: various technological processes; chemistry.

SUBSTANCE: invention is intended for production of ethylene and propylene from raw material of various composition, coming from oil and/or gas processing enterprises, by means of formation of optimum production systems and can be used in the field of petrochemical industry. Invention relates to a process flow diagram for production of ethylene and propylene from hydrocarbon material of various composition in a gas and/or liquid phase, which includes the following units and links connected by direct and feedback, in particular in the form of pipelines: (100) unit for receiving, preparation and mixing of raw materials of different composition, (200) thermal splitting unit, (300) unit for primary fractionation and water quenching of pyrolysis gas; (400) compression unit, (500) alkaline cleaning unit, (600) drying unit, (700) gas separation unit. At that, the need for water vapor of the corresponding parameters in thermal splitting (200), compression (400), drying (600) and gas separation (700) units are completely compensated by the generated water vapor energy flows of different pressure, formed in the units of the steam generation zone of the pyrolysis furnaces of thermal splitting unit (200) and in the unit for primary fractionation and water quenching of pyrolysis gas (300), together forming an additional system for generating water vapor, at that, steam flows of the same pressure generated in pyrolysis furnaces using different hydrocarbon raw materials from the raw material receiving, preparation and mixing unit (100) and in the pyrolysis gas primary fractionation and water quenching unit (300), are combined by common pipeline with corresponding consumers of compression (400), drying (600) and gas separation (700) units.

EFFECT: production of ethylene and propylene from hydrocarbon material of various composition in gas and/or liquid phase, exclusion of necessity to receive water vapor from outside the plant and/or supply of unused water vapor flows beyond the plant borders.

4 cl, 7 dwg

Description

The invention relates to technological schemes for the production of ethylene and propylene from raw materials of various compositions coming from oil and gas processing plants through the formation of optimal production systems and can be used in the field of petrochemical chemistry.

Ethylene and propylene are the basic monomers synthesized by petrochemical clusters in industrialized countries. The prospects for the development of polymerization technologies in Russia are closely related to the increase in capacity for the production of basic monomers. In turn, the main method for the production of base olefins (ethylene, propylene) is currently the process of pyrolysis of hydrocarbon raw materials in tube furnaces in the presence of water steam. Thus, the level of development of petrochemical chemistry is often assessed by the total pyrolysis capacities.

Various sources of hydrocarbon raw materials (ethane, liquefied hydrocarbon gases, gasoline fractions of various compositions, etc.) can be used as raw materials for pyrolysis production. When creating modern oil and gas chemical complexes, it is necessary to take into account the possibilities of processing gaseous or liquid hydrocarbon fractions produced at nearby oil refineries and/or gas processing plants in pyrolysis plants.

In recent decades, the main trends in the development of the process of high-temperature decomposition of hydrocarbon raw materials are associated with an increase in the yield of target products and with a decrease in the specific consumption of raw materials and energy (including fuel supplied to the burners of furnaces) for the production of one ton of olefins (or ethylene during pyrolysis in the ethylene mode, either propylene during pyrolysis in the propylene mode, or the sum of olefins in the olefin mode) (F.G. Zhagfarov, P.O. Guskov, A.L. Lapidus. Trends in the processing of gas hydrocarbon feedstock in the process of pyrolysis. Gas Chemistry - 2011, p. 26 -31). In this regard, the tasks of joint processing of mixed raw materials of various compositions coming from oil refineries and reducing specific energy consumption by intensifying the use of internal energy flows of pyrolysis industries are becoming increasingly urgent.

There is a known method for producing ethylene by pyrolysis of hydrocarbon raw materials heavier than ethane at a temperature of 750-870°C in a tubular furnace with the release of an ethylene-containing fraction, while a C ₃ -C ₅ hydrocarbon fraction is isolated from the pyrolysis products, which is hydrogenated to paraffins in the presence of palladium catalyst in the liquid phase at a molar ratio of hydrogen/C ₃ -C ₅ fraction equal to 0.8-2.5, and recycling of part of the hydrogenated C ₃ -C ₅ fraction in the hydrogenation reactor in relation to the original C ₃ -C ₅ fraction entering into the hydrogenation reactor, equal to 10-20:1, after which the hydrogenation products are sent as additional raw materials for pyrolysis, pre-mixed with fresh hydrocarbon raw materials (invention patent RU 2281316, IPC C10G 69/06, declared 05.05.2005, published August 10, 2006). The main disadvantages of the invention are:

- processing of raw materials limited in hydrocarbon composition from C ₃ and above, i.e. as feedstock, for example, propane, n-butane, wide fraction of light hydrocarbons (NGL), gasoline are used, which does not involve the use of ethane contained in LPG or in hydrocarbon gases produced at gas processing plants;

- there is no provision for the stage of extracting propylene from the C ₃ -C ₅ fraction to the stage of hydrogenation, which is a valuable petrochemical product;

- there is no provision for the extraction stage of C ₄ olefins from the C ₃ -C ₅ fraction to the hydrogenation stage, which are valuable petrochemical products.

There is a known method for the pyrolysis of hydrocarbon feedstock containing ethane and liquefied hydrocarbons, where the hydrocarbon feedstock is prepared by mixing ethane and liquefied hydrocarbon streams heated to a temperature of 60-150°C, with a content of liquefied hydrocarbons in the hydrocarbon feedstock from 5 to 30 wt. % is fed for pyrolysis in the presence of water steam, while propane, butane or their mixtures are used as liquefied hydrocarbons (invention patent RU 2764768, IPC C10G 9/00, C10G 45/26, declared 04/29/2021, published 01/21. 2022). The main disadvantages of the invention are:

- the possibility of processing gas feedstock of a given composition with a LPG share from 5 to 30% by weight is being considered, excluding the possibility of processing fractions in a wider range of changes in the ratio of ethane and LPG coming from oil refineries and characterized by variable composition;

- the possibility of involving gasoline fractions for co-pyrolysis, coming from oil refineries and characterized by variable composition, is excluded;

- there is no possibility of maintaining the balance of production/use of water vapor in conditions of supply of raw materials with a constantly changing ratio of ethane, LPG, gasoline fractions, characterized by variable composition.

A hydrocarbon processing system is also known, including: a separation unit configured to separate hydrocarbon feedstock into a light stream of fractions and a stream of heavy fractions; a process control unit having one or more control units and configured to adjust the level of separation in the separation unit based on olefin production requirements and electrical power requirements; a pyrolysis unit in fluid communication with the separation unit, wherein the pyrolysis unit is configured to create an effluent stream from a portion of the light ends stream; a fuel conversion unit in fluid communication with the separation unit and configured to convert part of the heavy fraction stream into raw material for the turbine; and a turbine in fluid communication with the fuel conversion unit and configured to generate electricity using at least a portion of the turbine power (patent WO 2012039890, IPC C10G 7/00, C10G 9/00, C10G 7/12, C10G 11/00, F02C 3/00, declared 08/26/2011, published 03/29/2012). The main disadvantages of this invention are:

- the use of a turbine to generate electricity entails a more complicated process and an increase in the cost of the generated electricity;

- the production of target olefins is reduced due to the use of part of the raw material as fuel for electricity generation.

The closest in technical essence to the proposed one is the gas-chemical production of ethylene and propylene, using hydrocarbon raw materials in the gas and/or liquid phase and including the following blocks connected by direct and reverse connections, in particular in the form of pipelines:

(1) a raw material preparation unit, providing for the removal of undesirable impurities and the production of a prepared raw material stream and consisting of:

(a) a section for removing mechanical particles by filtration;

(b) a section for removing impurities of carbon dioxide and sulfur compounds by absorption and/or adsorption;

(c) methanol removal section by absorption and/or adsorption and/or water washing;

(2) a mixing unit, providing for the combination of the prepared feed stream with water vapor and recycling of pyrolysis products produced in the thermal splitting unit (3) and released in the gas separation unit (8) in the form of the ethane fraction of the unit (c), and/or the propane fraction of the unit (g), and/or fractions C ₃ and above link (c), and/or fraction C ₄ and above link (e), and/or by recycling fraction C ₄ and below link (b) of the metathesis block (9) to obtain pyrolysis process raw materials;

(3) a thermal splitting unit, which provides an alternating stage of the actual pyrolysis of the raw materials of the pyrolysis process in the heating coils of reaction furnaces and the stage of removing the formed coke using the steam burning method with the capture of coke particles by means of cyclones and/or water washing with simultaneous production of water vapor for both stages, returned to mixing unit (2), as well as its overheating due to the heat of the flue gases of the reaction furnace;

(4) primary fractionation and water washing unit, consisting of:

(a) a primary fractionation unit that ensures the quenching of pyrogas by recycling quenching oil with the removal of pyro-resin, tar water and pyrobenzene and the use of circulation and/or acute irrigation, and/or with the production of water steam in the recovery boiler;

(b) a section of water washing of pyrogas with the removal of pyro-resin, tar water and pyro-gasoline and the use of circulation and/or acute irrigation and/or with the production of water steam in the recovery boiler;

(5) a compression unit providing compression of pyrogas to a pressure of 3.0-4.0 MPa in a four- or five-stage compressor, the drive of which is provided by the supply of high-pressure water vapor coming from the thermal splitting unit (3) and/or from the side, at in this case, the water condensed during the compression process is separated from the pyrogas between the stages of the compressor in separators-water separators with the possibility of its return to link (b) of the primary fractionation and water washing unit (4); hydrocarbons condensed during the compression process are separated from the pyrogas between the compressor stages in separators-water separators and sent to link (e) of the gas separation unit (8) in the pyrobenzene fractionation column, and/or to link (c) of the gas separation unit (8) to the pyrogas deethanization column, and/or into link (d) of the gas separation unit in the depropanization column; The pyrogas before the last compression stage is sent to the alkaline purification unit (6), and after the last compression stage - to the drying unit (7);

(6) an alkaline purification unit, providing for the removal of impurities from the pyrogas, including carbon dioxide and hydrogen sulfide, and consisting of:

(a) a pyrogas purification unit in one or more sections due to washing the pyrogas with a circulating alkaline solution with the replenishment of a fresh alkaline solution and the removal of a spent alkali solution;

(b) a section for water washing of the pyrogas from alkali and salts with the return of the pyrogas to the last compression stage in the compression block (5);

(c) the processing unit of the spent alkali solution before supply to treatment facilities by preliminary oxidation of sulfides to thiosulfates and/or sulfates or neutralization of alkali with sulfuric acid followed by stripping of acid gases;

(7) drying unit, which provides for the removal of water vapor from the compressed pyrogas by adsorbents to a depth that excludes hydrate formation in the gas separation unit (8), without cooling or with cooling of the pyrogas before drying to a temperature not lower than the temperature of hydrate formation, followed by regeneration of the adsorbent with dry hot gas: methane fraction from the side, or the raw ethane fraction, or the methane hydrogen fraction coming from link (a) of the gas separation unit (8), or the recycle ethane fraction coming from link (e) of the gas separation unit (8);

(8) a gas separation unit, which provides for the extraction of the necessary components from the dried compressed pyrogas and consists of units:

(a) the demethanization unit of the pyrogas coming from the drying unit (7), or unit (h) of the gas separation unit (8), or fraction C ₂ and below unit (c), or unit (h) of the gas separation unit (8), with simultaneous with or without the release of hydrogen-containing gas or demethanization of the fraction C ₃ and below, coming from the link (d) of the gas separation unit (8), providing sequential cooling of the pyrogas or fraction C ₃ and below with refrigerants or cold process streams of other parts of the gas separation unit (8), isentropic expansion and cooling of pyrogas or fraction C ₃ and below in one, two or three turboexpanders, separation, as well as subsequent separation of the methane hydrogen fraction and/or flow of hydrogen-containing gas in the gas phase from the coldest separator, and/or zone of the distillation column, and/or systems of distillation columns and separation of fraction C ₂ and above, sent to link (c), (e) or (h) of the gas separation unit (8), or the combination of separation and hydrogenation processes in links (a), and/or (c), and/or (d), and/or (and) a gas separation unit (8) in the presence of hydrogen with the corresponding conversion of acetylene and diene hydrocarbons of the pyrogas in a distillation column or a system of distillation columns with a catalyst integrated inside the distillation column;

(b) a unit for purifying hydrogen-containing gas from hydrocarbons, and/or carbon dioxide, and/or carbon monoxide, and/or nitrogen, and/or oxygen in adsorbers using the method of variable pressure and/or variable temperature and/or in membrane devices with further use purified hydrogen-containing gas as a process reagent;

(c) a unit for deethanization of the fraction C ₂ and above, produced in link (a) of the gas separation unit (8), or deethanization of pyrogas coming from the drying unit (7), or deethanization of the fraction C ₃ and below, produced in link (d) of the block gas separation (8), ensuring the division of the flow in a distillation column or system of distillation columns into an ethane-ethylene fraction or a fraction C ₂ and below and a fraction C ₃ and above, or a propane-propylene fraction, or combining the processes of separation and hydrogenation of pyrogas, or fraction C ₂ and above, or fractions C ₃ and below in the presence of hydrogen with the corresponding conversion of acetylene and diene hydrocarbons of pyrogas, or fractions C ₂ and above, or fractions C ₃ and below in a distillation column or a system of distillation columns with a catalyst integrated inside the distillation column, in this case, the fraction C ₃ and above is sent for separation to link (d) or (e) of the gas separation unit (8) or as a recycle flow - to the mixing unit (2), the propanepropylene fraction is sent for separation to link (g) or (h ) gas separation unit (8) or as a recycle flow - into the mixing unit (2);

(d) a link for the depropanization of pyrogas coming from the drying unit (7) or link (h) of the gas separation unit (8), or depropanization of fraction C ₃ and above coming from link (c) or (h) of the gas separation unit (8), providing separation of pyrogas or fraction C ₃ and higher in a distillation column or system of distillation columns into a propane-propylene fraction or fraction C ₃ and lower and fraction C ₄ and higher, or combining the processes of separation and hydrogenation of pyrogas or fraction C ₃ and higher in the presence of hydrogen with the appropriate by converting acetylene and diene hydrocarbons of pyrogas or fraction C ₃ and higher in a distillation column or a system of distillation columns with a catalyst integrated inside the distillation column, while the fraction C ₃ and lower is sent to link (a), (c) or (h) of the gas separation unit (8), the propane-propylene fraction is sent to the link (g) of the gas separation unit (8);

(e) a link for separating the ethane-ethylene fraction produced in link (a), (c) or (d) of the gas separation unit (8), ensuring its separation in a distillation column or distillation column system into high-purity ethylene and ethane directed by the recycle flow into a mixing unit (2), or combining the processes of separation and hydrogenation of the ethane-ethylene fraction in the presence of hydrogen with the corresponding conversion of acetylene hydrocarbons of the ethane-ethylene fraction in a distillation column or a system of distillation columns with a catalyst integrated inside the distillation column;

(f) a unit for separating the C ₃ and higher fraction produced in the deethanization unit (c) a gas separation unit (8), ensuring its separation in a distillation column or distillation column system into a propane-propylene fraction and a C ₄ and higher fraction or propane-propylene and butane-butylene fractions and fraction C ₅ and above with cooling of the flows by refrigerants or cold flows of section (a) and/or (c) of the gas separation unit (8); the propane-propylene fraction is sent to the link (g) of the gas separation unit (8); fraction C ₄ and above is removed as a commercial product or sent by recycle flow to the mixing unit (2); fraction C ₄ is removed as a commercial product or sent to link (a) of the metathesis unit (9) or by recycle flow to the mixing unit (2); fraction C ₅ and above is used as a component of gasoline and taken to the side;

(g) a link for separating the propane-propylene fraction produced in link (c), (d) or (h) of the gas separation unit (8), ensuring its separation in a distillation column or distillation column system into pure propylene and propane, directed by the recycle flow into mixing unit (2) or output as a commercial product, or combining the processes of hydrogenation and separation of the propane-propylene fraction with its preliminary hydrogenation in the presence of hydrogen with the corresponding conversion of methyl acetylene and propadiene in the gas or liquid phase on catalysts, followed by separation of the resulting hydrogenate in a distillation column or a system of distillation columns;

(h) the pyrogas hydrogenation unit coming from the drying unit (7), or the hydrogenation of the ethane-ethylene fraction coming from the unit (e) of the gas separation unit (8), or the hydrogenation of C ₂ and below, coming from the unit (c) of the gas separation unit ( 8), or hydrogenation of the propane-propylene fraction coming from link (g) of the gas separation unit (8), or hydrogenation of the C ₃ and lower fraction coming from link (d) of the gas separation unit (8), or hydrogenation of the C ₄ and higher fraction, coming from link (e) of the gas separation unit (8), which ensures the conversion of acetylene and/or diene components into the corresponding alkene compounds in a hydrogenation reactor on a catalyst in the presence of hydrogen in one or several stages with intermediate cooling, with the reaction products further depending on the hydrocarbon raw materials and produced products of gas chemical production are sent to link (a), (c), (d), (e), (f) or (g) of the gas separation unit (8);

(i) a link for separating the fraction C ₄ and above, coming from link (d) of the gas separation unit (8), ensuring its separation in a distillation column or system of distillation columns into the butane-butylene fraction and the fraction C ₅ and above with cooling of the flows with refrigerants or cold flows of link (a) and/or (c) of the gas separation unit (8), while the butane-butene fraction is removed as a commercial product or sent to link (a) of the metathesis unit (9) or by a recycle flow to the mixing unit (2); fraction C ₅ and above is removed as a component of gasoline;

(9) a metathesis unit consisting of: (a) a metathesis unit that ensures the reaction between the C ₄ and lower fraction coming from unit (e) of the gas separation unit (8) and containing butene-1 and butene-2, and ethylene coming from link (e) of the gas separation unit (8), with the formation of propylene and isomerization of butene-1 into butene-2; (b) a link for separating metathesis products coming from link (a) of the metathesis block (9), in a system of distillation columns with the separation of commercial products: pure propylene, or propylene and isobutane, or propylene, isobutane and isobutene, and unreacted components of fraction C ₄ and below, which are returned to the link (g) of the gas separation unit (8) or to the mixing unit (2) as recycle (patent RU 2670433, IPC S07S 11/04, S07S 11/06, S07S 2/76, S07S 4/ 04, С07С 7/00, declared 12/29/2017, published 10/23/2018). The main disadvantages of this invention are:

- there is no possibility of maintaining the balance of production/use of water vapor in conditions of supply of raw materials with a constantly changing ratio of ethane, LPG, gasoline fractions and varying composition;

- the technology does not involve the use of refinery gases as a gas feedstock, including streams with a high content of olefin hydrocarbons (ethylene, propylene) coming from delayed coking, catalytic cracking, visbreaking, ethylene polymerization, propylene polymerization and preparation of the feed stream for further processing.

The general disadvantages of the inventions are the presence of a deficit or excess of water vapor produced at the installation, and therefore there are additional costs for its generation or condensation, and the lack of involvement of gas feedstock with a high content of olefinic hydrocarbons (ethylene, propylene) coming from delayed coking plants, catalytic cracking, visbreaking, ethylene polymerization, propylene polymerization, providing for the preparation of the raw material stream for further processing.

The objective of the claimed invention is to carry out the process of pyrolysis from hydrocarbon raw materials of various compositions in the gas and/or liquid phase with the formation of optimal relationships aimed at maximizing the full use of the generated water vapor flows to supply energy to the gas separation unit.

The problem of the claimed invention is solved due to the fact that a technological scheme has been developed for the production of ethylene and propylene from hydrocarbon raw materials of various compositions in the gas and/or liquid phase, including the following blocks and links connected by direct and reverse connections, in particular in the form of pipelines:

(100) a unit for receiving, preparing and mixing raw materials of various compositions coming from oil refineries, providing for combining the raw material stream with recirculating streams and released in the gas separation unit (700) in the form of a propane fraction, and feeding the raw material stream into the thermal splitting unit (200);

(200) a thermal splitting unit consisting of a group of pyrolysis furnaces, each of which includes a convection zone link, a radiation zone link, a water vapor production zone link, and providing in each furnace an alternating stage of pyrolysis of raw materials in the radiation zone link of pyrolysis furnaces and a removal stage the resulting coke by steam burning with the capture of coke particles by means of cyclones with simultaneous production of ultra-high pressure water steam (UHP) for both stages, as well as its overheating due to the heat of the flue gases of the reaction furnace in the section of the water steam production zone;

(300) unit for primary fractionation and water quenching of pyrogas;

(400) a compression unit providing compression of pyrogas, as well as hydrocarbon gas coming from an oil refinery, to a pressure of 3.0-4.0 MPa on multi-stage compressors, the drives of which are provided by the supply of SVD water steam;

(500) an alkaline purification unit, providing for the removal of impurities from the pyrogas, including carbon dioxide and hydrogen sulfide;

(600) drying unit, providing for the removal of water vapor from the compressed pyrogas by adsorbents to a depth that excludes hydrate formation in the gas separation unit (700), without cooling or with cooling of the pyrogas before drying to a temperature not lower than the temperature of hydrate formation, followed by regeneration of the adsorbent with dry hot gas: methane fraction from the side, and/or methane fraction, and/or methane hydrogen fraction coming from the gas separation unit (700), heated by high pressure water vapor (HP) coming from the thermal separation unit (200);

(700) a gas separation unit providing for the extraction of the necessary components from the dried compressed pyrogas; - but not limited to this combination, while the need for water vapor of the corresponding parameters in the blocks of thermal splitting (200), compression (400), drying (600) and gas separation (700) is fully compensated by the generated energy flows of water vapor of various pressures formed in the units zones for producing water vapor in the pyrolysis furnaces of the thermal splitting unit (200) and in the unit for primary fractionation and water quenching of pyrogas (300), which together form an additional system for generating water steam, while flows of water vapor of the same pressure generated in pyrolysis furnaces using different hydrocarbons raw materials from the block for receiving, preparing and mixing raw materials (100), and in the block for primary fractionation and water quenching of pyrogas (300), are combined by a common pipeline with the corresponding consumers of the compression (400), drying (600) and gas separation (700) blocks.

The developed set of blocks and their constituent units for the production of ethylene and propylene, through the formation of direct and feedback connections between them, ensures the universality of production operation, regardless of the type of hydrocarbon raw materials processed and the range of products produced.

It is also advisable to use hydrocarbon gases as hydrocarbon feedstock, which are a fraction of light hydrocarbon gases, including streams with a high content of olefinic hydrocarbons (ethylene, propylene), which can be produced as a by-product at oil refineries and/or gas processing plants in the region.

It is advisable to use liquefied hydrocarbon gases (LPG) as a hydrocarbon feedstock, which is a mixture of ethane, propane and butanes, which can be produced as a by-product at nearby enterprises in the region.

It is advisable to use a liquid hydrocarbon fraction of petroleum origin as a hydrocarbon feedstock - naphtha and/or gas oil, which can be produced as a cheap by-product at a nearby oil refinery in the region.

Figures 1-7 show diagrams of possible options for implementing the claimed technological scheme for the production of ethylene and propylene using the following notations:

100 - block for receiving, preparing and mixing raw materials, including:

101 - unit for receiving, separating and compressing gas feedstock;

102 - LPG reception and evaporation section;

103 - unit for receiving and heating liquid raw materials;

200 - thermal splitting unit, used for any type of raw material, including:

201 - section of the convection zone of ethane pyrolysis furnaces;

202 - section of the convection zone of LPG and naphtha pyrolysis furnaces;

203 - section of the convection zone of naphtha pyrolysis furnaces;

204 - section of the radiation zone of ethane pyrolysis furnaces;

205 - section of the radiation zone of LPG and naphtha pyrolysis furnaces;

206 - section of the radiation zone of naphtha pyrolysis furnaces;

207 - steam generation unit for SVD ethane pyrolysis furnaces;

208 - steam generation unit for SVD pyrolysis furnaces of LPG and naphtha;

209 - steam generation unit for SVD naphtha pyrolysis furnaces;

210 - ZIA link of ethane pyrolysis furnaces;

211 - ZIA unit of LPG and naphtha pyrolysis furnaces;

212 - ZIA link of naphtha pyrolysis furnaces;

213 - steam system link;

300 - primary fractionation and water hardening unit, including:

301 - oil hardening link;

302 - unit for water washing of pyro-gas;

400 - compression block, including:

401 - compression link;

500 - alkaline cleaning unit, including:

501 - alkaline cleaning unit;

600 - drying unit, including:

601 - pyrogas pre-cooling link;

602 - pyrogas drying unit;

603 - gas preparation unit for regeneration of dryers;

604 - condensate drying unit;

700 - gas separation unit, for which the use of certain units of the unit and the order of supplying raw materials to the units are determined by the gas separation technology and the range of products produced, including:

701 - pyrogas cooling unit;

702 - deethanization link;

703 - absorption unit C _{3 and higher} ;

704 - fuel gas preparation unit;

705 - cooling unit C ₁ / C ₂ ;

706 - acetylene hydrogenation unit;

707 - C ₂ absorption unit;

708 - depropanization unit;

709 - part of the ethylene refrigeration cycle. Stage 1;

710 - link of the ethylene refrigeration cycle. Stage 2;

711 - part of the ethylene refrigeration cycle. Stage 3;

712 - link of the propylene refrigeration cycle. Stage 1;

713 - link of the propylene refrigeration cycle. Stage 2;

714 - link of the propylene refrigeration cycle. Stage 3;

715 - PPF hydrogenation unit;

716 - PPF separation unit;

717 - section for separating the C2 fraction;

718 - PCA link;

719 - demethanization link;

720 - debutanization link.

1-147 - pipelines.

Figure 1 shows one of the possible block diagrams for the production of pyrolysis, which makes it possible to process hydrocarbon feedstocks of various compositions.

The principle of operation of the technological line presented in Figure 1 when working with hydrocarbon raw materials of various compositions in the gas and/or liquid phase is based on the fact that the raw materials are supplied from outside the installation to the block for receiving, preparing and mixing raw materials (100), from where, after preparation, they are supplied into the thermal splitting unit (200). The process of thermal splitting of hydrocarbon raw materials is carried out by diluting it with water vapor, which is produced in the thermal splitting unit (200) and process water coming from the primary fractionation and water quenching unit (300). The pyrogas obtained in the thermal splitting unit (200) enters the primary fractionation and water quenching unit (300) for the purpose of cooling the pyrogas and separating it from heavy components, sent through the compression (400), alkaline purification (500) and drying (600) units. to the gas separation unit (700) in order to obtain commercial products (ethylene, propylene, BBF), sent further to polymerization units and/or to the consumer, while the hydrocarbon condensate leaving the compression unit (400) is dried in the drying unit (600) and supplied to the gas separation unit (700). The primary fractionation and water quenching (300) and gas separation (700) units also produce pyrobenzene and pyrolysis resin, which are removed from the plant as by-products of pyrolysis production. Ethane and propane released in the gas separation unit (700) are respectively returned as recirculating flows to the thermal splitting unit (200), part of the propane flow is also supplied to the raw material receiving, preparation and mixing unit (100), the MPV from the gas separation unit (700) is used in as fuel in pyrolysis furnaces of the thermal splitting unit (200). The compression (400) and primary fractionation and water hardening (300) blocks provide for the supply of refinery gases from the raw material receiving, preparation and mixing block (100); The alkaline cleaning unit (500) provides for the intake of fresh alkali to carry out alkaline cleaning and the removal of spent alkali.

Figures 2-7 show schematic diagrams of a block for receiving, preparing and mixing raw materials, a thermal splitting block, a primary fractionation and water hardening block, compression and alkaline purification blocks, a drying block and a gas separation block with the internal relationships of the units that make up these blocks.

Figure 2 shows a schematic diagram of the unit for receiving, preparing and mixing raw materials (100), into which, from outside the installation, oil refinery gases, LPG and naphtha are supplied, respectively, through pipelines 1, 4 and 7 to the units for receiving, separating and compressing gas raw materials (101 ), receiving and evaporating LPG (102) and receiving and heating liquid raw materials (103). In this case, the link (102) provides for the combination of the raw material flow with the recirculating flow of the propane fraction coming through pipeline 6 from the PPF separation link (716) of the gas separation unit (700). After preparing the refinery gases in link (101) for further processing, the flow of hydrocarbon gases through pipeline 3 enters the compression link (401) of the compression unit (400) and/or through pipeline 2 directly into the pyrogas water washing link (302) of the primary fractionation unit and water quenching (300), bypassing the thermal splitting unit (200), while the supply is redistributed based on the balance of water vapor production in the steam system link (213) of the thermal splitting unit (200). After mixing the raw LPG with the recirculating flow of propane supplied through pipeline 6 from the link (716), and evaporation, the prepared LPG flow through pipeline 5 is supplied to the sections of the convection zone of LPG and naphtha pyrolysis furnaces (202) and/or the convection zone of naphtha pyrolysis furnaces (203 ) thermal splitting unit (200) to carry out the corresponding chemical transformations. The preheated flow of liquid naphtha feedstock through pipeline 8 from link (103) enters the convection zone link of the naphtha pyrolysis furnaces (203) of the thermal splitting unit (200).

Figure 3 shows a schematic diagram of a thermal splitting unit (200), which is used for the transformation of any type of raw material. In the convection zone section of the ethane pyrolysis furnaces (201), preheating of the gas feed stream obtained by mixing recycled ethane supplied through pipeline 9, returned from the C ₂ fraction separation section (717) of the gas separation unit (700), is provided, its mixing with part of the recycled propane , coming through pipeline 6 from link (716), and process steam coming through pipeline 138, with a temperature of 180°C and under a pressure of 0.7 MPa, supplied to dilute the raw material flow from link (213). Preheating of raw materials, boiler water supplied through pipeline 17, and superheating of the SVD steam flow supplied through pipeline 15 at a temperature of 320°C and under a pressure of 11.25 MPa are carried out using flue gases supplied through pipeline 42 from the radiation zone section of the furnaces ethane (204) and then through pipeline 18 leaving the boundaries of the pyrolysis unit. The raw material stream, heated and diluted with process steam, is then supplied as a general flow through pipeline 10 to the radiation link of ethane pyrolysis furnaces (204), heated boiler water through pipeline 16 returns to the steam generation link of SVD ethane pyrolysis furnaces (207), and steam superheated to 510°C The SVD is accordingly sent through pipeline 19 to the steam system link (213).

In the convection zone section of the LPG and naphtha pyrolysis furnaces (202), preheating of the gas feed stream obtained by mixing the LPG feed stream supplied through pipeline 5 from link (102) is provided with naphtha supplied through pipeline 8 from link (103), and process steam supplied through pipeline 138 with a temperature of 180°C and a pressure of 0.7 MPa, supplied to dilute the raw material flow from the link (213). Preheating of raw materials, boiler water supplied through pipeline 29, and superheating of the SVD steam flow supplied through pipeline 27 with a temperature of 320°C and under a pressure of 11.25 MPa from the SVD steam generation unit of LPG and naphtha pyrolysis furnaces (208) are carried out in counting of flue gases entering through pipeline 43 from the radiation zone section of the LPG and naphtha pyrolysis furnaces (205) and then leaving the boundaries of the pyrolysis installation through pipeline 30. The LPG and naphtha raw material stream, heated and diluted with process steam, is then fed into the radiation section with a common flow through pipeline 22 LPG and naphtha pyrolysis furnaces (205), the heated boiler water is returned to the link (208) through pipeline 28, and the SVD steam superheated to 510°C is accordingly sent through pipeline 31 to the steam system link (213).

In the convection zone section of naphtha pyrolysis furnaces (203), preheating of the raw material stream obtained by mixing the naphtha flow coming through pipeline 8 from link (103) and process steam coming through pipeline 138 at a temperature of 180°C and at a pressure of 0 is provided. 7 MPa supplied to dilute the feed stream from unit (213). Preheating of raw materials, boiler water supplied through pipeline 39, and superheating of the SVD steam flow supplied through pipeline 37 with a temperature of 320°C and under a pressure of 11.25 MPa from the steam generation unit of SVD naphtha pyrolysis furnaces (209) are carried out using smoke gases entering through pipeline 44 from the radiation zone section of naphtha pyrolysis furnaces (206) and then through pipeline 40 leaving the boundaries of the pyrolysis installation. The naphtha raw material stream, heated and diluted with process steam, is then supplied with a common flow through pipeline 32 to the radiation link of the LPG and naphtha pyrolysis furnaces (206), heated boiler water through pipeline 38 is returned to link (209), and SVD steam superheated to 510°C through the pipeline 41 is accordingly sent to the steam system link (213).

A mixture of hydrocarbons with water vapor, preheated in the sections of the convection zone of pyrolysis furnaces (201), (202) and (203), enters through the corresponding pipelines 10, 22 and 32 into the sections of the radiation zone of ethane pyrolysis furnaces (204), the radiation zone of pyrolysis furnaces LPG and naphtha (205) and radiation zones of naphtha pyrolysis furnaces (206), respectively. The creation of high temperatures in the radiation zones of the pyrolysis furnaces of units (204), (205) and (206) is achieved by burning fuel gas supplied from the fuel gas preparation unit (704) through pipeline 20 to the thermal splitting unit (200), the resulting flows flue gases are sent through pipelines 42, 43 and 44 to the convection zone sections of pyrolysis furnaces (201), (202) and (203), respectively. In the pyrolysis furnaces of units (204), (205) and (206) operating in parallel on various raw materials, at temperatures of 750-950 ° C, chemical transformations of raw material hydrocarbons into unsaturated hydrocarbons, mainly ethylene and propylene, occur. The pyrogas formed as a result of transformations in the pyrolysis furnaces of units (204), (205) and (206) is sent through pipelines 11, 23 and 33 to the ZIA links of ethane pyrolysis furnaces (210), ZIA of LPG and naphtha pyrolysis furnaces (211) and ZIA of naphtha pyrolysis furnaces (212) for quenching (instant cooling) of pyrogas in order to terminate pyrolysis reactions. Quenching of pyrogas in ZIA in units (210), (211) and (212) is carried out by boiler water supplied through pipelines 13, 25 and 35 from the steam generation units of SVD ethane pyrolysis furnaces (207), the steam generation units of SVD pyrolysis furnaces of LPG and naphtha ( 208) and the generation of steam from SVD naphtha pyrolysis furnaces (209), respectively. In this case, as a result of cooling the pyrogas from the boiler water, SVD steam is generated with a temperature of 320°C and a pressure of 11.25 MPa, which returns through pipelines 14, 26 and 36 back to links (207), (208) and (209), respectively.

The units for generating SVD steam from ethane pyrolysis furnaces (207), generating SVD steam from LPG and naphtha pyrolysis furnaces (208) and generating SVD steam from naphtha pyrolysis furnaces (209) are designed to generate SVD steam from demineralized water supplied to the installation from the outside via pipeline 21, boiler heated water supplied through pipelines 16, 28 and 38 from links (201), (202) and (203), respectively, and from SVD steam supplied through pipelines 14, 26 and 36 from links (210), (211) and ( 212) respectively. In this case, the generated SVD steam is supplied for overheating through pipelines 15, 27 and 37, and boiler water is supplied for heating through pipelines 17, 29 and 39 to links (201), (202) and (203), respectively.

The cooled pyrogas with a temperature of 380°C and a pressure of 0.2 MPa through pipelines 12, 24 and 34 enters the common pyrogas manifold and then with a temperature of 400°C and a pressure of 0.09 MPa is sent through pipeline 51 to the oil quenching link (301) of the block primary fractionation and water quenching (300), while it is possible to supply part of the cooled pyrolysis gas from ethane pyrolysis furnaces through pipeline 62 to the pyrogas water washing link (302), bypassing the oil quenching link (301) of the primary fractionation and water quenching unit (300). In the coke burning mode, air is supplied to the ZIA links of ethane pyrolysis furnaces (210), ZIA of LPG and naphtha pyrolysis furnaces (211) and ZIA of naphtha pyrolysis furnaces (212) through pipeline 147. As a result of coke oxidation reactions, a mixture of gases consisting of carbon oxides is formed, which, after passing through cyclones where solid coke particles are captured, is then removed from the installation through pipeline 146.

The thermal splitting unit (200) contains a steam system link (213), designed to generate steam of various pressures for the needs of pyrolysis production. The unit processes SVD steam (510°C, 11.25 MPa), supplied through pipelines 19, 31 and 41 from units (201), (202) and (203), respectively, and demineralized water supplied to the installation from the outside via pipeline 21 , process water entering through pipeline 46 (74°C, 0.045 MPa) from the pyrogas water washing unit (302) of the primary fractionation and water quenching unit (300), and steam from the boundaries of the installation, entering through pipeline 45 (400°C, 4 .5 MPa) only in start-up mode until reaching the nominal value. In this case, process steam with parameters of 180°C and 0.7 MPa is generated, supplied through pipeline 138 to dilute the raw material before being supplied to the sections of the convection zone of the pyrolysis furnaces; SVD steam with parameters 510°C and 11.25 MPa, supplied through pipeline 47 to link (401) of the compression unit (400); HP steam with parameters 400°C and 4.5 MPa, supplied through pipeline 48 to the links of the ethylene refrigeration cycle (709), (710), (711) (stages 1-3) and the propylene refrigeration cycle (712), (713) , (714) (stages 1-3) of the gas separation unit (700) and the gas preparation unit for regeneration of dryers (603) of the drying unit (600); SD steam with parameters 300°C and 1.8 MPa, supplied through pipeline 49 to link (720) of the gas separation unit (700); LP steam with parameters 166°C and 0.6 MPa, supplied through pipeline 50 to the deethanization (702) and depropanization (708) sections of the gas separation unit (700).

Figure 4 shows a schematic diagram of a primary fractionation and water quenching unit (300), including an oil quenching unit (301), which provides quenching of the pyrogas supplied through pipeline 51 from the units (210), (211), (212), and partially returned pyrobenzene fractions through pipeline 142 from link (302) by recirculating cooled quenching oil (not shown in the figure). In the oil quenching section, one or more distillation columns are provided using circulation and/or acute irrigation, and/or with the generation of water steam in a recovery boiler (not shown in the figure). From the oil quenching unit (301), flows of pyro-gasoline are discharged beyond the boundaries of the installation through pipeline 52, pyro-resin through pipeline 53 and coke through pipeline 54, and the pyro-gas flow after oil quenching is directed through pipeline 55 to the pyro-gas water washing unit (302). In addition to the main pyrogas flow, the water washing (quenching) unit (302) also provides for the supply of a pyrogas flow through pipeline 62 coming from unit (210), and/or a gas flow through pipeline 2 from unit (101). Washing is carried out by circulating wash water with the supply of aqueous pyrogas condensate through pipeline 56 from the compression link (401) of the compression block (400). The main flow of pyrogas under a pressure of 0.045 MPa through pipeline 57 is sent for compression to the pressure required for subsequent fractionation of the pyrogas into unit (401). The produced pyrobenzene fraction is sent through pipelines 58 and 142 to the pyrogas pre-cooling unit (601) of the drying unit (600) and partially to the oil quenching unit (301), respectively. Process water obtained as a result of condensation of steam from the pyrogas flow is returned through pipeline 46 to link (213) for steam generation.

Figure 5 shows a schematic diagram of compression (400) and alkaline purification (500) units, represented by compression (401) and alkaline purification (501) units. Link (401) ensures compression of pyrogas flows coming through pipeline 57 from link (302) and from link (501) to the pressure required for subsequent fractionation of pyrogas, while the hydrocarbon fraction C _{2 and below} is supplied through pipeline 62 from the cooling link pyrogas (701), as well as refinery gases entering through pipeline 3 from link (101) and leaving through pipeline 63 from the PSA link (718) of the gas separation unit (700). Between the compression stages, the pyrogas fraction is supplied to the alkaline purification link (501), while the water condensed during the compression process (aqueous condensate) is separated from the pyrogas between the compressor stages in water separators and returned through pipeline 56 to the link (302), and the condensed water During the compression process, hydrocarbons are separated from the pyro-gas between the compressor stages in water separators, and after the last compression stage, the pyro-gas through pipeline 64 and the hydrocarbon condensate through pipeline 65 are supplied to link (601). In the alkaline cleaning unit (501), the pyrogas flow through pipeline 58 from unit (401) is washed in one or several sections with a circulating alkaline solution with the replenishment of fresh alkaline solution supplied from the side through pipeline 60, the spent alkali solution is removed from the installation through pipeline 59, the resulting in this case, the hydrocarbon condensate is supplied through pipeline 61 to the debutanization unit (720) of the gas separation unit (700). Due to the fact that the alkaline purification unit (501) involves removing impurities from the pyrogas, including carbon dioxide and hydrogen sulfide, the unit also provides for the removal of acid gases (not shown in the figure).

Figure 6 shows a schematic diagram of a drying unit (600), designed to remove water vapor from compressed pyrogas in the presence of adsorbents to a depth that excludes further hydrate formation at the gas separation stage without cooling or with cooling of the pyrogas before drying to a temperature not lower than the hydrate formation temperature. In the pyrogas pre-cooling unit (601), the pyrogas flows entering through pipeline 64, hydrocarbon condensate of pyrogas entering through pipeline 65 from the unit (401), and pyrobenzene entering through the pipeline 58 from the unit (302) are cooled by the propylene-refrigerant flow entering via pipeline 75 from link (713). After cooling, the pyrogas through pipeline 66 is supplied for drying to the pyrogas drying unit (602), and the pyrogas condensate through pipeline 67 is supplied for drying to the condensate drying unit (604), while the spent propylene refrigerant is returned to the unit (712) through pipeline 74. In the pyrogas drying (602) and condensate drying (604) units, the direct process of drying the incoming pyrogas flows through pipeline 66 and pyrogas condensate through pipeline 67 is carried out, which are then sent through pipelines 68 and 69 to the gas separation unit (700) in units (701) and (702) respectively. The drying process is carried out on adsorbents due to flows of circulating regeneration gas coming from link (603) through pipelines 71 and 73 to links (602) and (604), respectively, and returned after drying for regeneration to link (603) through pipelines 70 and 72 from links (602) and (604), respectively. In the regeneration gas preparation section of the dryers (603), the regeneration of the circulating flow of regeneration gas used to dry the pyrogas is carried out with dry hot gas: methane fraction from the outside, and/or methane fraction, and/or methane hydrogen fraction coming through pipeline 76 from the section (704 ), heated by HP water vapor coming from link (213) (not shown in the figure). The spent methane hydrogen fraction is returned through pipeline 77 to link (704).

Figure 7 shows a schematic diagram of a gas separation unit (700) with the extraction of the necessary components from the dried compressed pyrogas. Dried pyrogas under a pressure of 2.93 MPa through pipeline 68 from link (602) is supplied to the pyrogas cooling link (701), which also receives fraction C ₂ and higher from the absorption link C ₃ and higher (703) through pipeline 80. Cooling of the pyrogas in the unit (701) is carried out due to the fraction C ₂ and below, supplied through pipeline 85 from the unit (702), the methane fraction and the methane-hydrogen fraction (MHF), supplied from the cooling unit C ₁ / C ₂ (705) pipelines 86 and 87 respectively. As a result, cooled, dried pyrogas with a temperature of minus 3°C is produced in the link (701), which is sent under a pressure of 2.93 MPa through pipeline 81 to the absorption link C ₃ and higher (703). Stream C ₂ and below, which has transferred its cold, returns to link (401) through pipeline 62, flow MMF through pipeline 89 is supplied to extract hydrogen into link (718), while part of the flow is supplied to link (704), and flow C _{2 and higher} through pipeline 139 is sent to the deethanization unit (702) for the purpose of separation in a distillation column or distillation column system into fraction C ₂ and below and fraction C ₃ and above. The gas separation unit has a fuel gas preparation unit (704), in which the flow of fuel gas coming from outside through pipeline 79 is mixed, and IMF, coming through pipeline 89 from unit (701), with the production of IMF supplied through pipeline 20 to ensure operation of links (204), (205) and (206), as well as regeneration gas circulating through pipelines 76 and 77 in link (603). Link (702) provides for the separation of a mixed flow consisting of pyrogas condensate entering through pipeline 69 from link (604), flow C ₂ and above, flowing through pipeline 139 from link (701), and fraction flow C ₂ and above, entering through pipeline 95 from link (703). The refrigerants used are ethylene refrigerant supplied through pipeline 102 from link (711) and returned through pipeline 103 to the same link, and propylene refrigerant supplied through pipeline 88 from link (712) and returned through pipeline 90 to the same link. (712). Fraction C ₂ and below, obtained as a result of separation, in the gas phase through pipeline 85 is sent to link (701), fraction C ₃ and above through pipeline 96 enters link (708) to separate propane, and fraction C ₂ and below in liquid phase through pipeline 94 is sent for separation to link (703). The absorption unit C ₃ and above (703) is designed to extract hydrocarbons C ₃ and above from the dried pyrogas supplied through pipeline 81 from the link (701), and the fraction C ₂ and below supplied through pipeline 94 from the link (702). As a source of cold, propylene refrigerant is used, which enters through pipeline 91 from link (712) and, having transferred its cold, returns through pipeline 92 to link (712). The resulting distillation bottom product (fraction C ₂ and above) is supplied to the link (702) through pipeline 95, the upper rectification product (fraction C ₂ and below) is supplied through pipeline 93 to the acetylene hydrogenation link (706) for the purpose of acetylene hydrogenation, and the separated stream fractions C ₂ and higher are returned through pipeline 80 to link (701).

The gas separation circuit provides a cooling unit C ₁ /C ₂ (705), designed for heat exchange between refrigerant flows and fractions containing C ₁ -C ₂ hydrocarbons coming from other parts of the unit, in order to cool the ethylene refrigerant to lower temperatures. As a result, heat exchange occurs between the flows of ethylene refrigerant entering through pipelines 127, 128 and 132 from the unit (711), methane fraction, IMF and fraction C ₂ and below, entering through pipelines 78, 137 and 141, respectively, from the absorption unit C2 (707 ), fraction C ₂ and below, coming through pipeline 104 from the link (706), and the ethane-ethylene fraction coming through pipeline 98 from the demethanization link (719). In this case, the fraction C ₂ and below, coming through pipeline 104 from the acetylene hydrogenation unit (706), is the product of the hydrogenation reaction of the fraction C _{2 and below} , which is supplied through pipeline 93 from the link (703) in order to convert acetylene and/or diene components into the corresponding alkene compounds in a hydrogenation reactor on a catalyst in the presence of hydrogen in one or more stages with intermediate cooling. Next, from link (705), the flow of cooled ethylene refrigerant through pipelines 126 and 129 returns to link (711), the flow of ethylene refrigerant through pipeline 130 - to link (709), the methane fraction through pipeline 86 and IMF through pipeline 87 - to link (701), fractions C ₁ -C ₂ through pipeline 101 and fractions C ₂ and below through pipelines 99 and 100 - into link (719), fractions C ₂ and below through pipeline 140 - into link (707) and ethane-ethylene fraction through pipeline 105 - to link (717). In turn, the C ₂ absorption link (707) ensures the absorption of C ₂ components from the methane fraction coming through pipeline 107 from link (719), and from fraction C ₂ and below, coming through pipeline 140 from link (705), while directing the resulting flows of IMF and methane fractions into unit (705) for cooling the C ₁ -C ₂ fractions. Fraction C ₁ -C ₂ through pipeline 101 and fractions C ₂ and below through pipelines 99 and 100 enter the demethanization unit (719) to separate the methane fraction and hydrogen-containing gas due to sequential cooling with ethylene refrigerant supplied through pipeline 125 from the unit (711 ), by isentropic expansion and cooling of the C ₂ fraction and below in one, two or three turboexpanders, separation, as well as subsequent separation of the methane fraction and/or flow of hydrogen-containing gas in the gas phase from the coldest separator, and/or zone of the distillation column, and /or distillation column systems. The cube of the distillation column is heated by propylene refrigerant supplied through pipeline 119 from link (714), after which it returns through pipeline 97 for compression to link (713). As a result of separation, the ethane-ethylene fraction is sent through pipeline 98 to link (705), while the produced methane fraction in two streams through pipelines 106 and 107 enters links (705) and (707), respectively, and the spent ethylene refrigerant with a temperature of minus 103 °C through pipeline 121 is supplied for compression to link (709).

The separation of fraction C ₃ and above, coming through pipeline 96 from link (702), is carried out in a distillation column or a system of sequential distillation columns in the depropanization link (708). As a result, a separation occurs into a propane-propylene fraction or a fraction C ₃ and below and a fraction C ₄ and above, while the fraction C ₃ and below is sent through pipeline 114 to the PPF hydrogenation unit (715), in which it undergoes chemical transformations of acetylene and/or or diene components into the corresponding alkene compounds in a hydrogenation reactor on a catalyst in the presence of hydrogen, while the products of the hydrogenation reaction are further sent through pipeline 115 to the PPF separation unit (716). The hydrogen required for hydrogenation reactions is supplied through pipeline 118 from the short-cycle adsorption (SCA) unit (718). The PSA link is designed for the separation of gas mixtures, namely the release of hydrogen in the process of multi-stage adsorption in a system of adsorbers from the IMF, supplied through pipeline 89 from link (701), while the flow of PSA waste gas through pipeline 63 is sent to link (401), and the concentrated hydrogen is partially used for hydrogenation reactions in units (706) and (715) and/or is removed from the pyrolysis unit through line 117.

Fraction C ₄ and above, leaving the rectification stage of the deporpanization unit (708), is sent through pipeline 84 to the debutanization unit (720), where it is mixed with hydrocarbon condensate coming through pipeline 61 from unit (501), and is further separated in a distillation column or a system of distillation columns on butane-butyl, a new fraction (BBF), removed through pipeline 83 as a commercial product from the pyrolysis unit, and pyrobenzene, which is also removed through pipeline 82 from the pyrolysis unit as a component of gasoline.

The gas separation unit at the pyrolysis unit contains systems for an ethylene refrigeration cycle and a propylene refrigeration cycle, each of which includes three stages. The ethylene refrigeration cycle link in the first stage (709) is fed with ethylene coming through line 108 from link (717), and ethylene refrigerant coming through line 130 from link (705) and through line 121 from link (719) to generate ethylene - refrigerant supplied through pipeline 131 to the ethylene refrigeration cycle link to the second stage (710), where it is mixed with ethylene refrigerant supplied through pipeline 143 from link (717), from where it is then supplied through pipeline 136 to the ethylene refrigeration cycle link to the third stage (711), where ethylene refrigerant flows are also supplied for mixing through pipelines 103 from link (702), through pipelines 126 and 129 from link (705) and 112 from link (717). From link (711) it is possible to divert part of the ethylene flow through pipeline 113 from the installation to the consumer or for other needs of the enterprise. The main part of the ethylene is used as a refrigerant and is supplied by an ethylene-refrigerant flow through pipeline 102 into a link (702), by ethylene-refrigerant flows through pipelines 127, 128 and 132 into a link (705), through pipelines 109, 110 and 111 into a link (717 ) and through the pipeline 125 into link (719). In the section for separating the C ₂ fraction (717), the C ₂ fraction entering through pipeline 105 from link (705) is separated into ethylene and ethane in a distillation column or system of distillation columns, directed by a recycle flow through pipeline 9 to link (201), at In this case, ethylene is sent through pipeline 108 for compression into link (709). As refrigerants in the link (717), ethylene refrigerant flows coming through pipelines 109, 110 and 111, generated by the link (711), and a propylene refrigerant flow coming through the pipeline 122 from the link (712) are used, and after cooling the flow ethylene refrigerant flows through line 143 into link (710), and through line 112 returns to link (711), and the flow of propylene refrigerant through line 120 returns to link (712).

The propylene refrigeration cycle system begins with the propylene refrigeration cycle link from the first stage (712), into which propylene refrigerant is supplied as a return refrigerant through pipelines 74, 90, 92 and 120 from links (601), (702), (703), and (717) respectively. After compression, the resulting propylene refrigerant as a refrigerant with specified characteristics is supplied through pipelines 88, 91 and 122 to units (702), (703) and (717), respectively, with the main part of the propylene refrigerant flow at a temperature of minus 11 ° C and under a pressure of 0.165 MPa, it is sent through pipeline 144 to the propylene refrigeration cycle link to the second stage (713), which also receives propylene refrigerant flows through pipeline 97 from link (719) and through pipelines 123 and 124 from link (716). After compression at the second stage of the refrigeration cycle, the propylene refrigerant is partially supplied to the third stage in the propylene refrigeration cycle link (714) through pipeline 145 and partially through pipeline 75 to cool the pyrogas in the link (601). At the third compression stage, a stream of compressed propylene refrigerant is produced, which is partially supplied through pipeline 119 to link (719), and the main part of the propylene refrigerant at a temperature of 31 ° C and under a pressure of 1.6 MPa through pipelines 133, 134 and 135 is supplied to PPF separation link (716). In link (716), the PPF fraction, supplied through pipeline 115 from link (715), is separated in a distillation column or distillation column system into pure propylene and propane. Pure propane through pipeline 6 is sent as a recycle flow to link (102) and/or link (201), and pure propylene through pipeline 116 is removed beyond the boundaries of the installation as a commercial product and then sent to the consumer and/or for the enterprise's own needs. The flows of propylene refrigerants supplied through pipelines 133, 134 and 135 from unit (714), which, having worked, are supplied through pipelines 123 and 124 to unit (713), are used as refrigerants in distillation columns.

Example 1. Based on the considered pyrolysis technology, a calculation of the pyrolysis process was carried out when working simultaneously on liquid and gaseous raw materials, on the basis of which a material balance was compiled for the technological flows of the initial raw materials and final products (Table 1) and a material balance for water vapor (Table 2).

When calculating the material balance for water vapor, it was taken into account that during the implementation of the process with water as a substance of energy flows, both a change in energy potential can occur (water vapor enters the apparatus (input) and leaves the apparatus (output)), as well as its phase transformation (for example, the entrance of boiler water into the quenching-evaporation apparatus ZIA (water inflow) and its evaporation in this apparatus (flow rate in the form of high-pressure steam formed). As follows from the calculation of energy flows, the proposed technological scheme allows you to completely balance the inflow and consumption of water steam as a substance of energy flows (Table 2).

Thus, the invention provides the formation of a technological scheme for the production of ethylene and propylene from hydrocarbon raw materials of various compositions in the gas and/or liquid phase, ensuring the implementation of the pyrolysis process with the further production of ethylene and propylene, as well as related products, while ensuring full use of the energy resources of the installation, in particular water vapor, thereby eliminating the need to receive water vapor from outside the plant boundaries and/or supply unused streams of water vapor beyond the plant boundaries.

Claims (12)

1. Technological scheme for the production of ethylene and propylene from hydrocarbon raw materials of various compositions in the gas and/or liquid phase, including the following blocks and links connected by direct and feedback connections, in particular in the form of pipelines: (100) a unit for receiving, preparing and mixing raw materials of various compositions coming from oil refineries, providing for combining the raw material stream with recirculating streams and released in the gas separation unit (700) in the form of a propane fraction and feeding the raw material stream into the thermal splitting unit (200); (200) a thermal splitting unit consisting of a group of pyrolysis furnaces, each of which includes a convection zone link, a radiation zone link, a water vapor production zone link, and providing in each furnace an alternating stage of pyrolysis of raw materials in the radiation zone link of pyrolysis furnaces and a removal stage the resulting coke by steam burning with the capture of coke particles by means of cyclones with simultaneous production of ultra-high pressure water steam (UHP) for both stages, as well as its overheating due to the heat of the flue gases of the reaction furnace in the section of the water steam production zone; (300) unit for primary fractionation and water quenching of pyrogas; (400) a compression unit that provides compression of pyrogas, as well as hydrocarbon gas coming from an oil refinery, to a pressure of 3.0-4.0 MPa on multi-stage compressors, the drives of which are provided by the supply of SVD water steam; (500) an alkaline purification unit, providing for the removal of impurities from the pyrogas, including carbon dioxide and hydrogen sulfide; (600) drying unit, providing for the removal of water vapor from the compressed pyrogas by adsorbents to a depth that excludes hydrate formation in the gas separation unit (700), without cooling or with cooling of the pyrogas before drying to a temperature not lower than the temperature of hydrate formation, followed by regeneration of the adsorbent with dry hot gas: methane fraction from the side, and/or methane fraction, and/or methane hydrogen fraction coming from the gas separation unit (700), heated by high pressure water vapor (HP) coming from the thermal separation unit (200); (700) a gas separation unit, providing for the extraction of the necessary components from the dried compressed pyrogas, characterized in that the need for water vapor of the corresponding parameters in the blocks of thermal splitting (200), compression (400), drying (600) and gas separation (700) is fully compensated by the generated energy flows of water vapor of various pressures, formed in the sections of the zone for producing pyrolysis water vapor furnaces of the thermal splitting unit (200) and in the unit of primary fractionation and water quenching of pyrogas (300), which together form an additional system for generating water steam, while flows of water vapor of the same pressure generated in pyrolysis furnaces using different hydrocarbon raw materials from the receiving unit, preparation and mixing of raw materials (100), and in the unit for primary fractionation and water quenching of pyrogas (300), they are combined by a common pipeline with the corresponding consumers of the compression (400), drying (600) and gas separation units (700). 2. The technological scheme according to claim 1, characterized in that hydrocarbon gases produced at oil refineries and/or gas processing plants are used as hydrocarbon raw materials. 3. The technological scheme according to claim 1, characterized in that liquefied hydrocarbon gases (LPG), which are a mixture of ethane, propane and butanes, are used as hydrocarbon raw materials. 4. The technological scheme according to claim 1, characterized in that a liquid hydrocarbon fraction of petroleum origin - naphtha and/or gas oil - is used as a hydrocarbon feedstock.