EA032758B1 - Process for upgrading refinery heavy hydrocarbons to petrochemicals - Google Patents

Abstract

The present invention relates to a process for upgrading refinery heavy hydrocarbons to petrochemicals, comprising the following steps: (a) feeding a hydrocarbon feedstock to a ring opening reaction area; (b) feeding the effluent from (a) to a separation unit for producing a gaseous stream comprising light boiling hydrocarbons, a liquid stream comprising naphtha boiling range hydrocarbons and a liquid stream comprising diesel boiling range hydrocarbons; (c) feeding said liquid stream comprising naphtha boiling range hydrocarbons to a hydrocracking unit.

Description

The present invention relates to a method for upgrading heavy hydrocarbons from petroleum refining into petrochemical products.

EP No. 1779929 relates to a method for converting a sulfur-containing hydrocarbon feed into a form suitable for use in automotive diesel fuel.

Patent application US No. 2012/000819 relates to a method for producing high-value alkylbenzene and to the catalyst used for this, while the method provides a minimal opening reaction of the naphthenes cycle using a suitable hydrocracking reaction without causing undesired core hydrogenation.

US patent No. 4943366 relates to the production of high-octane gasoline by hydrocracking highly aromatic fractions obtained as a result of catalytic cracking processes, while gas oil or bottoms based feedstock is cracked in the FCC unit, and the cracked products are fractionated in the fractionation column of the cracking unit and in a distillation column. The low boiling fraction is then sent to a hydrotreatment unit, which forms the first stage of the hydrocracking unit. The hydrotreated gas oil is then sent to another hydrocracking unit, which forms the second stage of the unit, in which the aromatic compounds are saturated and the cycle is opened and cracked to form a hydrocracking product. After the hydrogen is separated in a separator, the hydrocracking unit effluent is separated into fractions in a distillation column to form products including dry gas, gasoline, middle distillate and bottoms.

WO 2007/055488 relates to a method for producing aromatic hydrocarbons and liquefied petroleum gas (LPG) from a hydrocarbon mixture comprising the following steps: (a) introducing a mixture of hydrocarbon feedstocks and hydrogen into at least one reaction zone; (b) converting the hydrocarbon feed mixture in the presence of a catalyst into (i) a non-aromatic hydrocarbon compound by hydrocracking and (ii) an aromatic hydrocarbon compound, which is present in large quantities in benzene, toluene and xylene (BTK), by dealkylation / transalkylation in the reaction zone ; and (c) obtaining CIS and aromatic hydrocarbon compounds, respectively, from the reaction products of stage (b) by gas-liquid separation and distillation.

WO 99/22577 relates to low pressure hydrocracking, the method comprising the following steps: (a) mixing the liquid feed with hydrogen gas; (b) hydrocracking said mixture in a fixed bed hydrocracking unit that contains at least two layers of compacted catalyst particles to form a lighter fraction and a heavier fraction; (c) directing a portion of the heavier fraction to a recirculation process prior to full production, comprising (1) directing the material to be recycled to the hydrocracking unit; and (2) recycling the heavier fraction of the effluent.

Patent application US 2012/205285 relates to a method for hydrotreating hydrocarbon feedstocks, which comprises (a) bringing the feedstuff into contact with (i) a diluent and (ii) hydrogen to produce a liquid feedstock; (b) bringing the liquid feed into contact with the first catalyst in the first processing zone to obtain a first product effluent; (c) bringing the first product effluent into contact with the second catalyst in the second processing zone to obtain a second product effluent; and (d) recirculating part of the second product effluent as a recycle product stream for use in the diluent in step (a), wherein the first processing zone contains at least two stages, wherein the first catalyst is a hydrotreating catalyst, and the second catalyst is a loop opening catalyst, the first and second processing zones are they are liquid-filled reaction zones.

Patent application US 2012/083639 relates to a method for maximizing the high value production of aromatic compounds by stabilizing the removal of crude benzene, the method comprising the steps of separating the aromatic compounds stream leaving the reactor containing a C ₅ - fraction and a C ₆ -C ₁₀ fraction a benzene-rich stream, at least one liquid stream and at least one vapor stream depleted in benzene, wherein one of the liquid stream depleted in benzene contains a benzene-depleted fra tion C ₆ -; and removing at least a portion of the C ₅ fraction from the benzene-rich stream.

Patent application US 2006/287561 relates to a method for increasing the formation of light C ₂ -C ₄ olefin hydrocarbons by combining a process for producing a mixture of aromatic hydrocarbons and liquefied petroleum gas (LPG) from a hydrocarbon mixture and a process for producing hydrocarbon feed which can be used as a feedstock in the first process.

Patent application US 2007/062848 relates to a method for hydrocracking a feed containing at least 20% by weight of one or more aromatic compounds containing at least two fused aromatic rings, wherein the compounds are unsubstituted or substituted with a maximum of two Ci-Q alkyl radicals with the formation of a product stream containing at least 35 wt.% a mixture of QQ-alkanes. According to patent application US No. 2007/062848, bitumen from oil sands is fed to a conventional distillation unit and the naphtha stream from the distillation unit is fed to a naphtha hydrotreatment unit. The head gas stream is a light gas / lung stream

- 1,032,758 paraffin and fed to the hydrocarbon cracking unit. The diesel fuel stream from the distillation unit is supplied to a diesel fuel hydrotreatment unit, and the gas oil stream from the distillation unit is supplied to a vacuum distillation unit, while the vacuum gas oil stream from the vacuum distillation unit is supplied to a gas oil hydrotreatment unit. A stream of light gas from a gas oil hydrotreatment unit is fed to a hydrocarbon cracker. Hydrotreated vacuum gas oil from the vacuum gas oil hydrotreatment unit is fed to the catalytic cracking unit. The bottoms stream from the vacuum distillation unit is a vacuum (heavy) residue and is sent to a delayed coking unit, forming several streams, such as a naphtha stream sent to a naphtha hydrotreatment unit, a diesel fuel stream sent to a diesel hydrotreatment unit to obtain hydrotreated diesel fuel and a gas oil stream directed to a vacuum gas oil hydrotreatment unit giving a hydrotreated gas oil stream directed to a catalytic crack installation nga.

US patent No. 4137147 relates to a method for producing ethylene and propylene from raw materials having a distillation temperature lower than about 360 ° C and containing at least normal and isoparaffins having at least 4 carbon atoms in a molecule in which (a) the specified the feedstock is subjected to a hydrogenolysis reaction in a hydrogenolysis zone in the presence of a catalyst; (b) the effluent from the hydrogenolysis reaction is fed to a separation zone from which (i) methane and possibly hydrogen are discharged from the top, (ii) a fraction consisting essentially of hydrocarbons with 2 and 3 carbon atoms in the molecule, and (iii) from the bottom, a fraction consisting essentially of hydrocarbons with at least 4 carbon atoms in the molecule; (c) only the specified fraction, consisting essentially of hydrocarbons with 2 and 3 carbon atoms in the molecule, is fed into the steam cracking zone in the presence of water vapor, to convert at least part of the hydrocarbons with 2 and 3 carbon atoms in the molecule into monoolefinic hydrocarbons; the specified fraction, consisting essentially of hydrocarbons with at least 4 carbon atoms in the molecule, obtained from the lower part of the specified separation zone, is fed into the second hydrogenolysis zone, where it is processed in the presence of a catalyst, the stream leaving the second hydrogenolysis zone is fed into the zone separation for the removal, on the one hand, of hydrocarbons with at least 4 carbon atoms in the molecule, which recycle, at least partially, in the specified second hydrogenolysis zone, and, on the other hand, of the fraction consisting of about essentially of a mixture of hydrogen, methane and saturated hydrocarbons with 2 or 3 carbon atoms in the molecule; a hydrogen stream and a methane stream are isolated from said mixture and hydrocarbons of said mixture with 2 and 3 carbon atoms are fed to said steam cracking zone, together with said fraction, consisting mainly of hydrocarbons with 2 and 3 carbon atoms in the molecule, obtained from said separation zone after the first hydrogenolysis zone. Thus, in addition to a methane stream, a hydrogen stream and a paraffin hydrocarbon stream with 2 and 3 carbon atoms in a molecule, olefins with 2 and 3 carbon atoms in a molecule and products with at least 4 carbon atoms in molecule.

EP 0219195 relates to a method for converting a feed containing hydrocarbon compounds into lower boiling, higher octane hydrocarbons by contacting said feed with hydrogen for the selective hydrogenation and hydrocracking of condensed bicyclic hydroaromatic hydrocarbon compounds to form a lower molecular weight, higher octane product .

WO 2012/071137 relates to a method for producing a gas cracking unit feedstock comprising contacting a feed material containing one or more paraffins with 4-12 carbon atoms, with a catalyst in the presence of hydrogen at elevated temperatures and elevated pressures and converting at least 40 wt.% paraffins with 4-12 carbon atoms, based on the total mass of paraffins with 4-12 carbon atoms in the feed, ethane and / or propane to obtain a hydrocracked feed for a gas cracking unit containing ethane and / or en.

US patent No. 6187984 relates to a method for the dehydrogenation of n-butane to butenes, which includes contacting a feed containing n-butane under reaction conditions suitable for the conversion of n-butane to butenes in the presence of a catalyst.

Patent application US 2003/232720 relates to a method for dehydrogenating a dehydrogenated hydrocarbon, comprising contacting a dehydrogenated hydrocarbon with a composite dehydrogenation catalyst to produce a dehydrogenated hydrocarbon.

Traditionally, crude oil is refined into several fractions, such as naphtha, gas oil and heavy residues. Each of these fractions has a number of potential applications, such as, for example, the production of transport fuels, such as gasoline, diesel fuel and kerosene, or as raw materials for some petrochemical products and other processing plants.

Light fractions of crude oil, such as naphtha and some gas oils, can be used to produce light olefins and monocyclic aromatics using processes such as steam cracking, in which the hydrocarbon feed is vaporized and diluted with water vapor and then exposed to very high temperatures (750-900 ° C) in the pipes of the furnace (reactor) for a short residence time (<1 s). In this process, carbohydrate molecules

- 2,032,758 hydrogen in the feed is converted (on average) to shorter molecules and molecules with lower hydrogen to carbon ratios (such as olefins) compared to the feed molecules. This process also forms hydrogen as a useful by-product and significant amounts of less valuable by-products, such as methane and C ₉ ⁺ aromatic hydrocarbons and condensed aromatic compounds (containing two or more aromatic rings with common sides).

As a rule, heavier (or higher boiling) aromatic compounds, such as heavy residues, are further refined in the crude oil refining unit to maximize the yield of lighter (distilled) products from crude oil. This processing can be carried out using processes such as hydrocracking (in which the feed for the hydrocracking unit is exposed to a suitable catalyst under conditions that lead to the breakdown of some of the feed molecules into shorter hydrocarbon molecules with the addition of hydrogen). Hydrocracking of heavy refining streams is usually carried out at high pressures and temperatures and, therefore, requires high investment.

The heavier fractions of crude oil are relatively rich in substituted aromatic compounds and in particular substituted condensed aromatic compounds (containing two or more aromatic rings in common), and under steam cracking conditions these substances produce significant amounts of heavy by-products, such as C ₉ ⁺ aromatic compounds and condensed aromatic compounds. Thus, the result of the traditional combination of crude oil distillation and steam cracking is that a significant portion of the crude oil is preferably not refined by a steam cracker, since the yield of valuable cracked products from heavier fractions is not considered to be sufficiently high compared to the alternative cost of refined fuel.

Another aspect of the technology described above is that even when only light fractions of crude oil (such as naphtha) are processed using steam cracking, a significant portion of the feed stream is converted to low-value heavy by-products such as C ₉ ⁺ aromatics and condensed aromatic compounds. With typical naphtha and gas oils, these heavy by-products can make up 2–25% of the total product yield (Table VI, p. 295, Pyrolysis: Theory and Industrial Practice, Lyle F. Albright et al., Academic Press, 1983). While this represents a significant reduction in the cost of expensive naphtha and / or gas oil to a less valuable material on the scale of a traditional steam cracking unit, the output of these heavy by-products usually does not justify the investment required to refine these materials (e.g. by hydrocracking) into streams that could produce significant quantities of more valuable chemical products. This is partly due to the fact that hydrocracking units are characterized by high capital costs, and, as in most petrochemical processes, the capital costs of these plants usually increase in proportion to the capacity raised to a power of 0.6 or 0.7. Consequently, the capital costs of a small scale hydrocracking unit are generally considered too high to warrant such investments in the processing of heavy by-products of steam cracking.

Another aspect of traditional hydrocracking of heavy refinery streams, such as heavy residues, is that it is typically carried out under compromise conditions selected to achieve the desired overall conversion. Since the feed streams contain a mixture of compounds differing in the degree of ease of cracking, this leads to the fact that some of the distillable products formed during the hydrocracking of relatively easily cracked compounds are additionally converted under conditions necessary for hydrocracking of compounds that are more difficult to hydrocrack. This increases hydrogen consumption and the difficulty of heat regulation associated with the process, and also increases the yield of light molecules such as methane due to more valuable compounds.

The result of this combination of crude oil distillation and steam cracking of lighter distillation products is that steam cracking furnaces are generally unsuitable for processing fractions that contain significant amounts of material with a boiling point in excess of ~ 350 ° C, since it is difficult to ensure complete evaporation of these fractions before exposing the mixed flow of hydrocarbons and steam to the high temperatures necessary to activate thermal cracking. If droplets of liquid hydrocarbon are present in the hot areas of the cracked pipes, coke is rapidly deposited on the surface of the pipe, which reduces heat transfer, increases the pressure drop and, ultimately, limits the operation of the cracking pipe, causing the furnace to be turned off to enable coke removal. Due to this drawback, a significant portion of the original crude oil cannot be refined into light olefins and aromatics using a steam cracker.

US 2009/173665 relates to a catalyst and method for increasing the content of monoaromatic compounds of hydrocarbon feed, which includes polynuclear aromatic compounds, where an increase in monoaromatic compounds can be achieved by increasing the yield of gasoline / diesel fuel while reducing undesirable compounds, thereby ensuring

- 3 032758 hydrocarbon refinement method, which include significant amounts of polynuclear aromatic compounds.

The UOP LCO Unicracking or LCO-X process described in WO 2009/008878 uses partial conversion hydrocracking to produce high-quality gasoline and diesel in a simple straight-through process flow. The feed is processed over the pre-treatment catalyst and then hydrocracked at the same stage. The products are then separated without the need for liquid recirculation. The LCO Unicracking process can be designed to operate at a lower pressure, which means that the pressure requirements will be slightly higher than with high rigidity hydrotreating, but significantly lower than with the traditional design of a partial and full conversion hydrocracking unit. An enriched medium distillate product is a suitable component for mixing ultra low sulfur diesel fuel (ULSD). The LCO-X low pressure hydrocracking process naphtha product has an ultra low sulfur content and a high octane rating and can be directly mixed in an ultra low sulfur gasoline (ULSG) pool.

US 7,513,988 describes a process for processing compounds containing two or more condensed aromatic rings to saturate at least one cycle and then rupture the resulting saturated cycle from the aromatic portion of the compound to form a C ₂ -C 4 alkane stream and aromatic stream. This method can be combined with a (steam) cracking unit for a hydrocarbon (e.g. ethylene), so that hydrogen from the cracking unit can be used to saturate and rupture compounds containing two or more aromatic rings, and a stream of C ₂ -C 4 alkanes can be fed into a hydrocarbon cracking unit or can be combined with a hydrocarbon cracking unit (for example, a steam cracking unit) and an ethylbenzene unit, which is intended for the treatment of heavy bottoms from oil refining sands, tar sands, shale oil or any oil having a high aromatic content with condensed rings to produce a stream suitable for petrochemical production.

US 2005/0101814 relates to a method for increasing the paraffin content of a feed for a steam cracking unit, comprising: supplying a feed stream containing QU hydrocarbons, including C ₅ -C ₉ normal paraffins, to a loop opening reactor, the loop opening reactor comprising a catalyst operating under conditions of conversion of aromatic hydrocarbons to naphthenes; and a catalyst operating under conditions of conversion of naphthenes to paraffins and the formation of a second feed stream; and entering at least a portion of the second feed stream into the steam cracking unit.

US patent No. 7067448 relates to a method for the production of n-alkanes from mineral oil fractions and fractions of thermal or catalytic conversion plants containing cyclic alkanes, alkenes, cyclic alkenes and / or aromatic compounds. In more detail, this publication relates to a method for processing mineral oil fractions with a high content of aromatic compounds, in which cyclic alkanes obtained after hydrogenation of aromatic compounds are converted to n-alkanes with a chain length which, as far as possible, is less than the chain length of the charged hydrocarbons.

As noted above, the LCO process refers to hydrocracking with the complete conversion of LCO to naphtha, where LCO is a stream containing monoaromatic and diaromatic compounds. The result of hydrocracking with full conversion is the production of high naphthenic low octane naphtha, which must be reformed to obtain the octane number required for mixing oil products.

WO 2006/122275 relates to a process for refining heavy hydrocarbon feedstocks of crude oil into oil that is less dense or lighter and contains less sulfur than the original heavy hydrocarbon feedstock of crude oil, while producing more valuable substances such as olefins and aromatics, the method includes, inter alia, the stage of combining part of the heavy hydrocarbons of crude oil with an oil-soluble catalyst to form a reaction mixture; the reaction of the pre-treated feed at a relatively low pressure of hydrogen to form a product stream, with the first part of the product stream including light oil fractions, the second part of the product stream including heavy bottoms of crude oil and the third part of the product stream including light hydrocarbon gas ; and introducing a portion of the light hydrocarbon gas stream into the cracking unit to produce streams containing hydrogen and at least one olefin.

WO 2011/005476 relates to a process for the processing of heavy oils, including crude oil, vacuum residue, tar sands, bitumen and vacuum gas oils, using a preliminary catalytic hydrotreatment process, in particular with the sequential use of hydrodemetallization catalysts (HDM) and hydrodesulfurization (HDS) to increase the efficiency of subsequent processing in the coking unit.

US 2008/194900 relates to a method for producing olefins for steam cracking a naphtha stream containing aromatics, including obtaining streams of olefins and pyrolysis gasoline from the effluent of a steam cracking furnace; hydrogenation of the pyrolysis gasoline stream and extraction of a C ₆ -C ₈ stream from it; hydrotreating a naphtha stream containing aromatic compounds to produce a raw naphtha; dearomatization of the C ₆ -C ₈ stream with a feed of naphtha in a conventional aromatic extraction unit to produce a raffinate stream and feeding the raffinate stream to a steam cracking furnace.

WO 2008/092232 relates to a method for extracting chemical components from a feedstock, such as oil, natural gas condensate or petrochemical feedstocks, such as crude feed naphtha, comprising the steps of subjecting a crude feed naphtha to a desulfurization process; the allocation from the desulfurized crude crude naphtha hydrocarbon fraction C ₆ -Cn; recovering a fraction of aromatic compounds, a fraction of aromatic precursors and a raffinate fraction from a hydrocarbon fraction of a C ₆ -Cn fraction in an aromatic extraction unit; conversion of a fraction of aromatic precursors to aromatic compounds; and recovering the aromatic compounds of the previous step in the aromatic extraction unit.

The objective of the present invention is to provide a method for upgrading heavy hydrocarbons into aromatic compounds (BTXE, BTEC) and the CIS.

Another objective of the present invention is to provide a method for producing light olefins and aromatic compounds from heavy hydrocarbon feedstocks in which a high yield of aromatic compounds can be achieved.

Another objective of the present invention is to provide a method of refinement of the supplied crude oil into petrochemical products with high carbon efficiency and hydrogen integration.

Thus, the present invention relates to a method for upgrading heavy hydrocarbons from petroleum refining into petrochemical products, comprising the following steps:

(a) supplying hydrocarbon feed to a loop opening reaction zone;

(b) supplying an effluent from (a) to a separation unit to produce a gaseous stream containing low boiling hydrocarbons, a liquid stream containing naphtha boiling range hydrocarbons, and a liquid stream containing diesel boiling range hydrocarbons;

(c) supplying said liquid stream containing naphtha boiling range hydrocarbons to a hydrocracking unit; (d) separating the reaction products of said stage hydrocracking unit (c) into a head gas stream containing low boiling hydrocarbons and a bottoms stream containing BTX (benzene mixture, toluene and xylenes), (e) supplying a head gas stream from the hydrocracking unit of step (d) and a gaseous stream from the separation unit of stage (b) to the steam cracking unit and at least one or more units OF DATA installation of propane dehydrogenation dehydrogenation of butane and the combined dehydrogenation of butane-propane, preferably after separation flow containing hydrogen from said gas streams.

The authors of the present invention suggest that by combining the process of opening the cycle with a hydrocracking unit, i.e. the so-called gasoline hydrocracking unit / feed hydrocracking unit (GHC / FHC), the method as a whole no longer produces fuels in addition to the CIS and BTEK, but only the CIS and BTEK. The latter can also be obtained directly in the form of a purified stream, since all substances boiling at the same temperature as BTEK are cracked. LPG can be used in steam cracking and / or PDH / BDH. The resulting hydrogen can be used to feed these stages of hydroprocessing. If necessary, hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) can be applied in accordance with the requirements of the catalyst / process. The term hydrocracking is used here in its generally accepted sense and, thus, can be defined as a catalytic cracking process, activated by the presence of an increased partial pressure of hydrogen; see, for example, Alike et al. (2007). The products of this process are saturated hydrocarbons and, depending on the reaction conditions, such as temperature, pressure, space velocity and catalyst activity, aromatic hydrocarbons, including BTK.

The term LPG, as used herein, is a generally abbreviated term for liquefied petroleum gas. The CIS usually consists of a mixture of ^ Ad-hydrocarbons, i.e. mixtures of C ₃ and C ₄ hydrocarbons.

One of the petrochemical products obtained in the method of the present invention is BTX (BTX). The term BTX, as used herein, refers to a mixture of benzene, toluene and xylenes. Preferably, the product obtained in the method of the present invention also contains valuable aromatic hydrocarbons, such as ethylbenzene. Accordingly, the present invention preferably provides a method for producing a mixture of benzene, toluene, xylenes and ethylbenzene (BTXE, BTEC). The resulting product can be a physical mixture of different aromatic hydrocarbons or can be directly subjected to additional separation, for example, with

5,032,758 distillation to obtain various streams of refined products. Such a refined product stream may include a benzene product stream, a toluene product stream, a xylene product stream and / or an ethylbenzene product stream. The terms naphthenic hydrocarbons, or naphthenes, or cycloalkanes used in this document have their well-established meaning and, accordingly, refer to types of alkanes having one or more carbon atom cycles in the chemical structure of molecules.

The liquid effluent or even the entire effluent from the reactor as a result of the loop opening process, preferably after separation of only the heavier recirculation stream containing polycyclic components, is fed to a hydrocracker (GHC / FHC). This greatly simplifies the process of opening the cycle and reduces the necessary redundancy in the separation plants. It should be noted that in another embodiment, the liquid effluent is vaporized before being fed to the hydrocracker. Thus, the feed for the hydrocracking unit may be in the liquid phase, the vapor phase, or in the mixed vapor-liquid phase. A hydrogen circuit can be used around both plants, i.e. a loop opening reaction zone and a hydrocracking unit (GHC / FHC), with several points of hydrogen addition and injection. According to another embodiment, only part of the naphtha stream is sent to the FHC / GHC reaction section, and possibly all the heavier material is recycled for further conversion, thereby simplifying the process flow.

The present method also includes separating the reaction products of said hydrocracking unit of step (c) into a head gas stream containing low boiling hydrocarbons and a bottoms stream containing BTX. The gaseous stream containing hydrogen may be separated from the overhead gas stream containing low boiling hydrocarbons.

Preferably, the method of the present invention also includes supplying a head gas stream from the hydrocracking unit of step (d) and a gaseous stream from the separation unit of step (b) to another separation unit, and feeding the thus separated streams to said steam cracking unit and said installation (s) dehydrogenation.

In accordance with the present invention, the dehydrogenation process is a catalytic process and the steam cracking process is a thermal cracking process.

According to a preferred embodiment, the method also includes supplying a head stream from a hydrocracking unit and a gaseous stream from a separation unit to a steam cracking unit and at least one or more units selected from a propane dehydrogenation unit, a butane dehydrogenation unit and a combined propane dehydrogenation unit butane, preferably after separation of the stream containing hydrogen from gas streams.

By adding loop opening, it is possible to process heavier feeds than would be possible with direct feed to the FHC / GHC unit. In addition, the addition of a separation unit before the loop opening process allows the FHC / GHC unit to convert any naphthenic compounds in the feed stream boiling in the naphtha range into aromatic compounds / BTK. In this way, a higher BTX yield can be obtained compared to using only one cycle opening, since these naphthenic compounds would otherwise be cracked in the cycle opening process with the formation of LPG, and not BTK.

According to a preferred embodiment, the present method also includes pre-treating the hydrocarbon feed in a separator, from which the hydrocarbons of the boiling range of naphtha are fed directly to the hydrocracking unit, and its heavier fraction is fed to the loop opening zone.

The present method also preferably includes pretreatment of the hydrocarbon feed in an aromatics extraction unit, from which an aromatic rich stream is supplied to the reaction zone to open the loop, wherein the aromatics extraction unit is selected from the group of distillation unit, molecular sieve type and unit type of liquid extraction.

In addition to using the above separator, the BTX yield can be further increased due to preliminary cracking of the feedstock using hydrocracking technology. Such a preferred method can produce highly naphthenic and aromatic material of the naphtha boiling range depending on the type of raw material that can be processed in the FHC / GHC section, with the formation of a maximum BTX, since even more naphthenic compounds are again converted to BTX compared to direct feed to cycle opening process.

The hydrogen circulation circuit for the three reaction zones can be optimized for purity, cascade circuit, pressure levels. The heavy unconverted material at the outlet of the loop opening reactor can be recycled either to the loop opening process or to the first hydrocracking stage.

Thus, the present method preferably also includes pre-treatment of the hydrocarbon feed in a pre-hydrocracking unit, from which a gaseous stream containing LPG is supplied to the steam cracking unit and to at least one or a pain

- 6,032,758 a larger number of units selected from a propane dehydrogenation unit, a butane dehydrogenation unit and a combined propane-butane dehydrogenation unit, its heavier hydrocarbon fraction is fed to the loop opening reaction zone, and a stream containing hydrocarbons of the naphtha boiling range is fed directly to the hydrocracking unit .

The inventors have found that in another embodiment, the first pre-hydrocracking step can be replaced by a hydrodealkylation / reforming process giving a high purity BTEC stream. As a result, an even greater amount of BTX can be obtained compared to the embodiment with the preliminary hydrocracking stage due to the active additional formation of aromatic compounds in the first reforming type reactor, which means that not only the aromatization of naphthenes, but also some formation of an additional cycle must take place.

Thus, the present method preferably also includes pretreatment of the hydrocarbon feed in a hydrodealkylation / reforming unit from which a BTEK stream is obtained, a gaseous stream containing LPG is fed to at least one or more units selected from the steam cracking unit , propane dehydrogenation units, butane dehydrogenation units and the combined propane-butane dehydrogenation unit, and its heavier hydrocarbon fraction are fed to the reaction zone of the separation niya cycle.

The present method preferably also includes feeding a bottoms stream, for example a BTK rich stream, from a hydrocracking unit to a transalkylation unit.

In addition, the present method preferably also includes supplying a liquid stream containing hydrocarbons of the boiling range of diesel fuel from the separation unit to the saturation unit of aromatic compounds.

The present method preferably also includes supplying at least one of a gaseous stream from a separation unit, a gaseous stream from a hydrodealkylation / reforming unit, and a gaseous stream from a pre-hydrocracker to a hydrocracker. In accordance with another embodiment, at least one of the streams from the hydrodealkylation / reforming unit and from the pre-hydrocracking unit is directed to the loop opening reaction zone. Such a stream may be a gaseous stream.

The overhead stream from the hydrocracking unit, the gaseous stream from the separation unit, and possibly the gaseous streams from the pre-hydrocracking unit and the hydrodealkylation / reforming unit, can be divided into separate streams, where each stream predominantly contains C ₂ paraffins, C ₃ paraffins and C ₄ paraffins, and each individual stream is fed into a special section of the furnace of the steam cracking unit, while the stream containing hydrogen is sent to one or more process units hydrogen consuming cells such as a hydrocracking unit and a loop opening reaction zone.

According to a preferred embodiment, the gaseous stream directed to the steam cracking unit is partially directed to the dehydrogenation unit, while it is preferable to direct only the C ₃ -C ₄ fraction to the dehydrogenation unit, in particular as separate C ₃ and C ₄ streams, more preferably in the form of a combined stream of C ₃ + C ₄ .

Thus, the present method includes a combination of a steam cracking unit and at least one unit selected from the group consisting of a butane dehydrogenation unit, a propane dehydrogenation unit, a combined propane-butane dehydrogenation unit, or a combination of these units to produce a mixed product stream. This combination of plants gives a high yield of target products, namely olefin and aromatic petrochemical products, while the proportion of crude oil converted to the CIS is significantly increasing.

According to a preferred embodiment, the gaseous streams, for example the head gas stream from the hydrocracking unit of stage (d) and the gaseous stream from the separation unit of stage (b), are separated into one or more streams, wherein the stream containing hydrogen is preferably used as a hydrogen source for hydrocracking; a methane containing stream is preferably used as a fuel source; a stream containing ethane is preferably used as feed for a steam cracking unit; a propane-containing stream is preferably used as feed for a propane dehydrogenation unit; a butane-containing stream is preferably used as a feedstock for the butane dehydrogenation unit; a stream containing Cj minus is preferably used as a fuel source and / or as a hydrogen source; a stream containing Q-minus is preferably used as feed for a propane dehydrogenation unit, however, in accordance with another embodiment, also as a feed for a steam cracking unit; a stream containing C ₂ -C ₃ is preferably used as feed for a propane dehydrogenation unit, however, in accordance with another embodiment, also as a feed for a steam cracking unit; a stream containing Ci-C ₃ is preferably used as feed for a propane dehydrogenation unit, however, in accordance with another embodiment, also as a feed for a steam cracking unit; a stream containing QQ-butanes is preferably used as feed for

- 7 032758 tan butane dehydrogenation units; a stream containing C ₂ -C ₄ butanes is preferably used as feed for a butane dehydrogenation unit; a stream containing C ₂ minus is preferably used as feed for a steam cracker; a stream containing C ₃ -C ₄ is preferably used as feed for a steam cracking unit; a stream containing C ₃ -C ₄ is preferably used as feed for a propane or butane dehydrogenation unit, or a combined propane and butane dehydrogenation unit; a stream containing C ₄ minus is preferably used as a feedstock for the butane dehydrogenation unit.

The present method also includes producing hydrogen from the reaction products of one or more plants selected from a steam cracking unit, a propane dehydrogenation unit, a butane dehydrogenation unit and a combined propane-butane dehydrogenation unit, and supplying the thus obtained hydrogen to the hydrocracking unit and to the reaction zone opening the cycle, in particular also includes obtaining hydrogen from the dehydrogenation unit and supplying thus obtained hydrogen to any of the plants consuming x hydrogen, as, for example, in a hydrocracking unit and in the reaction zone for opening the cycle.

The technological conditions prevailing in the reaction zone for opening the cycle include preferably a temperature of from 100 to 500 ° C and a pressure of from 2 to 10 MPa, a supply of 50-300 kg of hydrogen per 1000 kg of raw material over the catalyst for the hydrogenation of aromatic compounds and the direction of the resulting stream to the ring breaking unit at a temperature of from 200 to 600 ° C and a pressure of from 1 to 12 MPa, with a supply of 50-200 kg of hydrogen per 1000 kg of the obtained stream above the catalyst for breaking the ring.

The term “aromatic” opening unit refers to an oil refinery for carrying out a hydrocracking process suitable for the conversion of a feed that is relatively rich in aromatic hydrocarbons having a boiling point in the boiling range of kerosene and gas oil, with the formation of a LPG and depending on the process conditions of light distillate ( gasoline derived from aromatic (ARO) compounds). Such a process for opening the aromatic cycle (ARO process) is described, for example, in US No. 7513988. Accordingly, the ARO process may include saturation of the aromatic cycle at a temperature of 300-500 ° C, a pressure of 2-10 MPa, with a flow of 10-30 wt. % hydrogen (relative to the hydrocarbon feed) in the presence of a catalyst for the hydrogenation of aromatic compounds and rupture of the ring at a temperature of 200-600 ° C, a pressure of 1-12 MPa, when 5-20 wt.% hydrogen (relative to the hydrocarbon feed) is fed in the presence of a catalyst for breaking the ring, while the specified saturation of aromatic The ring and ring rupture can be carried out in one reactor or in two successive reactors. The aromatics hydrogenation catalyst may be a conventional hydrogenation / hydrotreating catalyst, such as a catalyst containing a mixture of Ni, W, and Mo on a refractory support, typically alumina. The ring-breaking catalyst contains a metal component and a carrier, preferably one or more metals selected from the group consisting of Pd, Rh, Ru, Ir, Os, Cu, Co, Ni, Pt, Fe, Zn, Ga, In, Mo, W and V. By selecting the residence time under conditions of saturation of the aromatic cycle, the process can be directed towards full saturation and subsequent rupture of all cycles (a relatively long residence time under conditions of saturation of the aromatic cycle) or towards keeping one aromatic cycle unsaturated and subsequent ruptureall cycles except one (a relatively short residence time in conditions of saturation of the aromatic cycle). In the latter case, the ARO process forms a light distillate (ARO gasoline), which is relatively rich in hydrocarbon compounds having one aromatic cycle.

Technological conditions prevailing in the separation plant preferably include a temperature of 149 to 288 ° C. and a pressure of 1 to 17.3 MPa.

The technological conditions prevailing in the hydrocracking unit include preferably a reaction temperature of 300-580 ° C, preferably 450-580 ° C, more preferably 470-550 ° C, a pressure of 0.3-5 MPa gauge, preferably a pressure of 0.6-3 MPa gage, particularly preferably a pressure of 1-2 MPa gage, most preferably a pressure of 1.2-1.6 MPa gage, hourly average feed rate (WHSV) 0.1-10 h ^-1 , preferably 0.2-6 h ^-1 , more preferably 0.4-2 h ^-1 .

The technological conditions prevailing in the steam cracking unit preferably include a reaction temperature of about 750-900 ° C, a residence time of 50-1000 ms and a pressure from atmospheric to 175 kPa gage.

A widespread process for converting alkanes to olefins involves steam cracking. As used herein, the term steam cracking refers to a petrochemical process in which saturated hydrocarbons are broken down into smaller, often unsaturated hydrocarbons, such as ethylene and propylene. In steam cracking, gaseous hydrocarbon feeds, such as ethane, propane and butanes, or mixtures thereof (gas cracking), or liquid hydrocarbon feeds, such as naphtha or gas oil (liquid cracking), are diluted with steam and heated for a short time in the furnace in the absence of oxygen. Typically, the reaction temperature is very high, about 850 ° C, but the reaction can only take a very short time, usually with a residence time of 50-500 ms. Preferably, hydrocarbon compounds, such as ethane, propane and butanes, are cracked separately in appropriate specialized furnaces to provide optimum cre

- 8,032,758 king. After the cracking temperature has been reached, the gas is quickly cooled to stop the reaction, in the pipe heat exchanger or inside the quench manifold using quenching oil. Steam cracking leads to a slow deposition of coke, a type of coal, on the walls of the reactor. Removing coke requires the furnace to be disconnected from the process, and then a stream of water vapor or steam-air mixture is passed through the furnace coils. This turns a solid layer of non-volatile carbon into carbon monoxide and carbon dioxide. After this reaction is completed, the furnace is returned to operation. Products obtained using steam cracking depend on the composition of the feedstock, the ratio between the amounts of hydrocarbon and water vapor, the cracking temperature and the residence time in the furnace. Light hydrocarbon feedstocks such as ethane, propane, butanes or light naphtha produce product streams rich in lighter polymerization grade olefins, including ethylene, propylene and butadiene. Heavier hydrocarbons (crude and heavy naphtha and gas oil fractions) also produce products rich in aromatic hydrocarbons.

To separate the various hydrocarbon compounds resulting from steam cracking, the cracking gas is sent to a fractionation unit. Such fractionation plants are well known in the art and may include a so-called gasoline distillation column in which the heavy distillate (carbon black oil) and the middle distillate (cracked distillate) are separated from the light distillate and gases. In the downstream quench tower, most of the light distillate produced by steam cracking (pyrolysis gas or pyrobenzene) can be separated from the gases by condensation of the light distillate. Subsequently, the gases can be subjected to several stages of compression, while the rest of the light distillate can be separated from the gases between the stages of compression. Also acidic gases (CO ₂ and H ₂ S) can be removed between the compression stages. In the next stage, the gases obtained by pyrolysis can be partially condensed at the steps of the cascade cooling system to approximately a state in which only hydrogen remains in the gas phase. The various hydrocarbon compounds can subsequently be separated by simple distillation, with ethylene, propylene and C4 olefins being the most important high-value chemical products from steam cracking. Steam methane methane is commonly used as fuel gas; hydrogen can be recovered and recycled to processes that consume hydrogen, such as hydrocracking processes. The steam cracked acetylene is preferably selectively hydrogenated to ethylene. The alkanes contained in the cracked gas can be recycled to the process to convert alkanes to olefins.

The term propane dehydrogenation unit, as used herein, refers to a unit for carrying out a petrochemical process in which a propane feed stream is converted to a product containing propylene and hydrogen. Accordingly, the term butane dehydrogenation unit refers to a process unit for converting butane feed to C4 olefins. Together, the processes of dehydrogenation of lower alkanes, such as propane and butanes, are described as the process of dehydrogenation of lower alkanes. Lower alkane dehydrogenation processes are well known in the art and include oxidative dehydrogenation processes and non-oxidative dehydrogenation processes. In the process of oxidative dehydrogenation, process heat is provided by the partial oxidation of lower alkane (alkanes) in the feed. In the non-oxidative dehydrogenation process, which is preferred in the context of the present invention, the process heat for the endothermic dehydrogenation reaction is provided by external heat sources such as hot flue gases from fuel gas combustion or water vapor. For example, the Oleflex (UOP) process allows for the dehydrogenation of propane to produce propylene and the dehydrogenation of (iso) butane to form (iso) butylene (or mixtures thereof) in the presence of a catalyst containing platinum supported on alumina in a moving bed reactor; see, for example, US No. 4827072. The STAR (Uhde) process allows dehydrogenation of propane to form propylene or dehydrogenation of butane to produce butylene in the presence of a promoted platinum catalyst supported on a zinc aluminate spinel support; see, for example, US No. 4926005. The STAR process has recently been improved by applying the oxydehydrogenation principle. In the secondary adiabatic zone in the reactor, part of the hydrogen from the intermediate product is selectively converted by adding oxygen to form water. This shifts the thermodynamic equilibrium towards a higher conversion and provides a higher yield. In addition, the external heat required for the endothermic dehydrogenation reaction is partially provided by the exothermic conversion of hydrogen. The Catofin process (Lummus) uses several fixed bed reactors operating on a cyclic basis. The catalyst is activated alumina impregnated with 18-20 wt.% Chromium; see, for example, EP No. 0192059 A1 and GB No. 2162082 A. The Catofin process is reported to be reliable and can process impurities that would poison a platinum catalyst. The products from the butane dehydrogenation process depend on the nature of the butane feed and the butane dehydrogenation process used. In addition, the Catofin process allows the dehydrogenation of butane to form butylene; see, for example, US No. 7622623.

- 9 032758

The hydrocarbon feed of step (a) is selected from the group consisting of shale oil, crude oil, kerosene, diesel fuel, atmospheric gas oil (AGO), gas condensates, waxes, crude naphtha, vacuum gas oil (VGO), vacuum residue, atmospheric residue, naphtha and pre-refined naphtha, or a combination thereof. Other preferred feedstocks are light recycle gas oil / heavy recycle gas oil (LCO / HCO), naphtha and coking unit diesel fuel, naphtha and FCC diesel fuel, and even slurry oil.

The present invention will be described in more detail below with reference to the accompanying drawings, in which the same or similar elements are denoted by the same reference numbers, and where:

in FIG. 1 is a schematic illustration of an embodiment of a method of the invention;

in FIG. 2 shows another embodiment of the method of the invention; in FIG. 3 shows another embodiment of a method of the invention; in FIG. 4 shows another embodiment of a method of the invention; in FIG. 5 shows another embodiment of the method of the invention; in FIG. 6 shows another embodiment of the method of the invention.

We now turn to the method and installation schematically represented in FIG. 1, which shows a method 101 for upgrading heavy hydrocarbons from petroleum refining to petrochemical products. The hydrocarbon feed 5 is sent to the loop opening reaction zone 1, and the effluent 17 leaving it is sent to a separation unit 2 forming a gaseous stream 4 containing LPG, a liquid stream 18 containing hydrocarbons of a boiling range of naphtha, and a liquid stream 15 containing hydrocarbons of a boiling range diesel fuel. Stream 15 containing hydrocarbons of the boiling range of diesel fuel is preferably recycled to the inlet of the loop opening reaction zone 1. Stream 18 containing hydrocarbons of the boiling range of naphtha is sent to a hydrocracking unit 3, forming a head gas stream 9 containing LPG, and bottoms stream 11 containing aromatic hydrocarbons, such as BTK. Stream 4 and stream 9 are combined as stream 10 and further processed in a steam cracking unit and a dehydrogenation unit selected from the group of a propane dehydrogenation unit, a butane dehydrogenation unit, and a combined propane / butane dehydrogenation unit. In this embodiment, the gaseous stream 10 is first separated in the separation unit 20 into separate streams 24, 25, 26. However, the number of streams is not limited. Fraction 24 of light hydrocarbons is sent to a gas cracking unit 22, and the effluent from it is sent to an additional separation section 23, and section 23 may contain several separation plants. The streams 25, 26 are processed in a dehydrogenation section 21, and this section 21 may comprise several dehydrogenation units, such as a propane dehydrogenation unit, a butane dehydrogenation unit and a combined propane / butane dehydrogenation unit. The dehydrogenated effluent 28 is sent to a separation unit 23 and is separated into separate streams 29, 30, for example, streams containing olefins. However, the number of threads is not limited. In accordance with another embodiment, stream 4 may (partially) be directed to a hydrocracking unit 3 forming a head gas stream 9 containing LPG and bottoms stream 11 containing aromatic hydrocarbons such as BTX.

According to method 201 (see FIG. 2), the hydrocarbon feed 5 is pretreated in a separator 5, forming a stream 16 containing hydrocarbons of the boiling range of naphtha. Stream 16 is sent directly to the hydrocracking unit 3. The effluent of separator 5 containing heavy hydrocarbons is directed to the loop opening reaction zone 1. The loop opening reaction zone 1 forms an effluent 17. Stream 17 is sent to a separation unit 2 forming a gaseous stream 4 containing a LPG, a liquid stream 18 containing naphtha boiling range hydrocarbons, and a stream 15 containing diesel boiling range hydrocarbons. Stream 15 containing hydrocarbons of the boiling range of diesel fuel is preferably recycled to the inlet of the loop opening reaction zone 1. Stream 18 is then subjected to conversion in a hydrocracking unit 3, forming a head gas stream 9 containing LPG, and bottoms stream 11 containing BTX. Stream 4 and stream 9 are combined as stream 10 and can be processed further, as described in the description of FIG. 1 above. In accordance with another embodiment, stream 4 may (partially) be directed to a hydrocracking unit 3 forming a head gas stream 9 containing LPG and bottoms stream 11 containing aromatic hydrocarbons such as BTX.

In addition to using the separator 5, as noted above in FIG. 2, the BTX output can be further improved by providing a preliminary cracking unit 6. According to method 301 of FIG. 3, the hydrocarbon feed 5 is pre-cracked in a pre-cracker 6, forming a gaseous stream 13, and a bottoms stream 8 containing naphtha. Stream 8 is sent directly to the hydrocracking unit 3. The heavy fraction exiting the preliminary cracking unit 6 is sent to the reaction loop opening zone 1. In the loop opening reaction zone 1, hydrocarbons leaving the pre-hydrocracking unit 6 are converted to form an effluent 17. The effluent 17 is directed to a separation unit 2 to form a gaseous stream 4 containing LPG, a liquid stream 18 containing hydrocarbons of a naphtha boiling range, and stream 15 containing hydrocarbons of the diesel boiling range

- 10 032758 fuel. Stream 15 containing hydrocarbons of the boiling range of diesel fuel is recycled to the inlet of the preliminary cracking unit 6. Stream 18 is fed to a hydrocracking unit 3, forming a head gas stream 9 containing LPG, and bottoms stream 11 containing BTX. Gaseous streams 4 and 9 are combined as stream 10, and stream 10 can be further processed, as noted above in FIG. 1. In accordance with another embodiment, stream 4 and stream 13 can (partially) be directed to a hydrocracking unit 3 forming a head gas stream 9 containing LPG and bottoms stream 11 containing aromatic hydrocarbons such as BTX. In addition, stream 13 may (partially) be directed to the cycle opening reaction zone 1.

According to another embodiment, now represented by method 401 in FIG. 4, the first hydrocracking stage discussed above for FIG. 3 can be replaced by a hydrodealkylation unit 7, from which a BTEC stream 12 and a gaseous stream 14 containing LPG are obtained. The heavier fraction leaving the unit 7 is directed to the cycle opening reaction zone 1 and as a result forms an exit stream 17. The effluent 17 from the cycle opening reaction zone 1 is sent to a separation unit 2, forming a gaseous stream 4 containing LPG, a liquid stream 18 containing naphtha boiling range hydrocarbons and a stream 15 containing diesel boiling range hydrocarbons. Stream 15 containing hydrocarbons in the boiling range of diesel fuel is recycled to the inlet of the hydrodealkylation unit 7. The stream 18 is sent to the hydrocracking unit 3, forming the head gas stream 9 containing the LPG, and the bottoms stream 11 containing the BTX. The BTEK enriched stream formed in unit 7 can be further processed in unit 3 of hydrocracking. Gaseous streams 14, 4 and 9 are combined as stream 10, which can be processed further, as described above for FIG. 1. In accordance with another embodiment (not shown), stream 4 and stream 14 can (partially) be directed to a hydrocracking unit 3 forming a head gas stream 9 containing LPG and bottoms stream 11 containing aromatic hydrocarbons such as BTX. In addition, stream 14 may (partially) be directed to the loop opening reaction zone 1.

In the preferred embodiment shown in FIG. 5, in accordance with method 501 for upgrading heavy hydrocarbons from petroleum refining to petrochemical products, hydrocarbon feed 5 is sent to the loop opening reaction zone 1, and the effluent 17 leaving it is sent to a separation unit 2 forming a gaseous stream 4 containing LPG, a liquid stream 18 containing hydrocarbons of a boiling range of naphtha, and a liquid stream 15 containing hydrocarbons of a boiling range of diesel fuel. Stream 15 containing hydrocarbons of the boiling range of diesel fuel can be (partially) recycled to the inlet of the reaction zone 1 of the loop opening. In FIG. 5 also shows that stream 15, containing hydrocarbons of the boiling range of diesel fuel, is sent as stream 49 to aromatics saturation unit 50, forming stream 51. The remaining process units and streams are similar to those indicated for FIG. 1 above. In accordance with another embodiment, stream 4 may (partially) be directed to a hydrocracking unit 3 forming a head gas stream 9 containing LPG and bottoms stream 11 containing aromatic hydrocarbons such as BTX.

According to another preferred embodiment, at least a portion of benzene and toluene and aromatic compounds with carbon numbers 9 and 10 are introduced into the transalkylation zone. In accordance with this embodiment shown in FIG. 6 as method 601, stream 11 is introduced into transalkylation zone 60 to increase the formation of xylene compounds, resulting in stream 62. Direct-flow hydrogen-rich gaseous stream 61 is also introduced into transalkylation zone 60. This gaseous stream 61 can be obtained from other hydrogen generating plants, such as, for example, hydrogen obtained from the reaction products of a steam cracking unit and a dehydrogenation unit. Operating conditions, preferably used in the transalkylation zone, include a temperature of 177 to 525 ° C. and an hourly space velocity of the liquid in the range of 0.2-10 h ⁻¹ . Any suitable transalkylation catalyst may be used in the transalkylation zone. Preferred transalkylation catalysts comprise a molecular sieve, a refractory inorganic oxide and a reduced non-lattice weak metal. Preferred molecular sieves are zeolite aluminosilicates, such as MFI type zeolites, which can be any zeolite having a silica to alumina ratio of more than 10 and a pore diameter of 5 to 8 angstroms. In accordance with another embodiment, stream 4 may (partially) be directed to a hydrocracking unit 3 forming a head gas stream 9 containing LPG and bottoms stream 11 containing aromatic hydrocarbons such as BTX.

- 11 032758

Examples

The process flow diagram used here corresponds to that shown in FIG. 1. Hydrocarbon feed 5 was fed into the loop opening reaction zone 1, and the reaction products 17 that were formed in this reaction zone were separated by unit 2 into the overhead stream 4, side stream 18 and still bottoms 15. Side stream 18 was fed into the unit 3 gasoline hydrocracking (GHC), while the reaction products of the 3 GHC installation were separated into a head gas stream 9 containing light components such as ^ - ^ paraffins, hydrogen and methane, and stream 11, containing mainly aromatic hydrocarbon compounds and non-aromatic carbohydrates homogeneous compounds. The head gas stream 9 from gasoline hydrocracking unit 3 (GHC) was combined with stream 4 exiting installation 2.

According to case 1 (an example in accordance with the invention), kerosene was sent as a feed to the cycle opening reaction zone and a side stream from it was sent to a gasoline hydrocracker (GHC), the CIS fraction was isolated from the overhead of unit 2.

According to case 2 (an example in accordance with the invention), light vacuum gas oil (LVGO) was sent as a feed to the cycle opening reaction zone and a side stream from it was sent to a gasoline hydrocracker (GHC), the LPG fraction was separated from the overhead of unit 2.

Characteristics of kerosene and LVGO are given in table. 1. In the table. 2 shows the distribution of monoaromatic compounds and aromatic molecules with more than one cycle (di + aromatic compounds) in the feed. In the table. 3 shows the composition of the products at the outlet of the group of plants (wt.% Raw materials).

Table 1

Characteristics of Kerosene and LVGO

Kerosene LVGO n-paraffins wt.% 23.7 18.3 i-paraffins wt.% 17.9 13.8 naphthenes wt.% 37,4 35.8 aromatic compounds wt.% 21.0 32,0 density 60F kg / l 0.810 0.913 Transnational corporation ° C 174 306 T10 ° C 196 345 TZO ° C 206 367 T50 ° C 216 384 T70 ° C 226 404 T90 ° C 242 441 TKK ° C 266 493

Table 2 The division of aromatic molecules into classes depending on the number of aromatic cycles in kerosene and LVGO

Kerosene LVGO Total Aromatics wt.% raw materials 21.0 32,0 Monoaromatic compounds wt.% raw materials 12.5 9.0 Di + aromatics wt.% raw materials 8.5 23.0

Table 3

The composition of the products at the outlet of the group of plants (wt.% Raw materials)

Component Case 1: Kerosene Case 2: LVGO CIS 87.8 89.4 ethane 24.8 25.3 propane 54D 55.1 n-butane 7.1 7.2 isobutane 1.8 1.8 BTK 12,2 10.6 benzene s, s 2.9 toluene 5.9 5.1 xylenes s oh 2.6

The data presented above show that the presence of a loop opening reaction zone and a gasoline hydrocracking (GHC) unit for raw materials leads to the conversion of polycyclic aromatic molecules to more valuable monocyclic aromatic compounds and LPG. In addition, BTX is also obtained by dehydrogenating naphthenes to monocyclic aromatic compounds.

Claims (14)

CLAIM 1. The method of refinement of heavy hydrocarbons from petroleum refining into petrochemical products, comprising the following stages: (a) supplying hydrocarbon feed to a loop opening reaction zone; (b) feeding the effluent of step (a) into a separation unit to produce a gaseous stream containing low boiling hydrocarbons, a liquid stream containing hydrocarbons of a boiling range of naphtha, and a liquid stream containing hydrocarbons of a boiling range of diesel fuel; (c) supplying said liquid stream containing naphtha boiling range hydrocarbons to a hydrocracking unit; (d) separating the reaction products of said hydrocracking unit of step (c) into a head gas stream containing low boiling hydrocarbons and a bottoms stream containing BTX (a mixture of benzene, toluene and xylenes); (e) separating the head gas stream from the hydrocracking unit of step (d) and the gaseous stream from the separation unit of step (b) into separate streams and supplying said separate streams to the steam cracking unit and at least one or more units selected from the unit propane dehydrogenation, butane dehydrogenation unit and combined propane-butane dehydrogenation unit. 2. The method according to claim 1, wherein the hydrogen-containing stream is separated from the head gas stream from the hydrocracking unit of step (d) and the gaseous stream from the separation unit of step (b). 3. The method according to claim 1 or 2, further comprising supplying a head gas stream from the hydrocracking unit of step (d) and a gaseous stream from the separation unit of step (b) to another separation unit, and supplying the streams thus separated to said steam cracking unit and said installation (s) of dehydrogenation. 4. The method according to any one of claims 1 to 3, wherein said dehydrogenation process is a catalytic process and said steam cracking process is a thermal cracking process. 5. The method according to any one of claims 1 to 4, comprising pre-processing said hydrocarbon feedstock in an aromatic compound extraction unit, from which a stream rich in aromatic compounds is supplied to said cycle opening reaction zone, wherein the aromatic compound extraction unit is selected from the group: distillation unit molecular sieve type and liquid extraction unit; or pre-processing said hydrocarbon feed in a separator, from which hydrocarbons of the boiling range of naphtha are fed directly to said hydrocracking unit and its heavier fraction is fed to said cycle opening zone; or pre-processing said hydrocarbon feedstock in a preliminary hydrocracking unit, from which a fraction of heavy hydrocarbons is supplied to said cycle opening reaction zone, a stream containing hydrocarbons of a naphtha boiling range is fed directly to said hydrocracking unit, and a gaseous stream containing LPG is supplied to a steam installation cracking and into one or more plants selected from a propane dehydrogenation unit, butane dehydrogenation unit and a combined unit for hydrogenation of propane-butane; or pre-processing said hydrocarbon feedstock in a hydrodealkylation / reforming unit from which a BTEK type stream is obtained, a fraction of heavy hydrocarbons is fed to said cycle opening reaction zone, and a gaseous stream containing LPG is fed to a steam cracking unit and to one or more units selected from a propane dehydrogenation unit, a butane dehydrogenation unit and a combined propaneabutane dehydrogenation unit. 6. The method according to claim 5, further comprising supplying at least one stream from said gaseous stream from said separation unit of step (b), said gaseous stream from said hydrodealkylation / reforming unit, and said gaseous stream from said preliminary hydrocracking unit to said unit hydrocracking. 7. The method according to any one of claims 3 to 6, further comprising supplying said bottoms stream from said hydrocracking unit to a transalkylation unit. 8. The method according to any one of claims 1 to 7, further comprising supplying said liquid stream containing hydrocarbons of a boiling range of diesel fuel from said separation unit to an aromatic compound saturation unit. 9. The method according to any one of claims 1 to 8, further comprising separating a head gas stream from said hydrocracking unit, a gaseous stream from said separation unit of step (b), and possibly gaseous streams from said preliminary hydrocracking unit and said hydrodealkylation / reforming unit into separate streams, each stream predominantly containing O ₂ paraffins, O ₃ paraffins and O ₄ paraffins, respectively; and feed each - 13 032758 separate flow into a special section of the furnace of the specified steam cracking unit, while the stream containing hydrogen is sent to one or more process units consuming hydrogen, such as the specified unit (preliminary) hydrocracking and the specified reaction zone breaking cycle, and comprising supplying only C ₃ -C ₄ fractions to at least one of said dehydrogenation plants, in particular as separate C ₃ and C ₄ streams, more preferably as a combined C ₃ + C ₄ stream. 10. The method according to any one of claims 1 to 9, in which the technological conditions prevailing in the specified reaction zone opening cycle are a temperature of from 100 to 500 ° C, a pressure of from 2 to 10 MPa and a flow of 50-300 kg of hydrogen per 1000 kg of raw materials passed over a catalyst for the hydrogenation of aromatic compounds, the resulting stream is sent to a ring breaker operating at a temperature of 200 to 600 ° C, a pressure of 1 to 12 MPa and a flow of 50-200 kg of hydrogen per 1000 kg of the obtained obtained stream passed over the catalyst breaking rings. 11. The method according to any one of claims 1 to 10, in which the technological conditions prevailing in the specified separation unit are a temperature of from 149 to 288 ° C and a pressure of from 1 to 17.3 MPa. 12. The method according to any one of claims 1 to 11, in which the technological conditions prevailing in the specified hydrocracking unit are a reaction temperature of 300-580 ° C, preferably 450-580 ° C, more preferably 470-550 ° C, pressure 0, 3-5 MPa gage, preferably a pressure of 0.6-3 MPa gage, particularly preferably a pressure of 1-2 MPa gage, most preferably a pressure of 1.2-1.6 MPa gage, hourly average feed rate (WHSV) 0 1-10 h ^-1 , preferably 0.2-6 h ^-1 , more preferably 0.4-2 h ^-1 . 13. The method according to any one of claims 1 to 12, in which the technological conditions prevailing in the steam cracking unit are a reaction temperature of about 750-900 ° C, a residence time of 50-1000 ms, and atmospheric pressure to 175 kPa gage. 14. The method according to any one of claims 1 to 13, in which the hydrocarbon feedstock of stage (a) is selected from the group consisting of shale oil, crude oil, kerosene, diesel fuel, atmospheric gas oil (AGO), gas condensates, waxes, crude naphtha vacuum gas oil (VGO), vacuum residue, atmospheric residue, naphtha and pre-refined naphtha, light recycle gas oil / heavy recycle gas oil (LCO / HCO), naphtha and diesel fuel of coking unit, naphtha and diesel fuel F CC, suspension oil or their suspension combinations.