KR20210155725A - Method for preparing aromatic hydrocarbon - Google Patents

Abstract

The present invention relates to a method for preparing aromatic hydrocarbon, which can expect an energy saving effect, and the method includes: supplying a raw material stream to a C6 separation column, supplying an upper discharge stream of the C6 separation column to a first hydrogeneration unit, and supplying a lower discharge stream to a C7 separation column; supplying the upper discharge stream of the C7 separation column to the first hydrogeneration unit, and supplying the lower discharge stream to a C8 separation column; separating benzene and toluene from the discharge stream of the first hydrogeneration unit; removing the lower discharge stream from the C8 separation column, and supplying the upper discharges stream to a second extraction distillation column; and separating styrene from the lower discharge stream of the second extraction distillation column, and separating xylene from the upper discharge stream.

Description

Method for producing aromatic hydrocarbons {METHOD FOR PREPARING AROMATIC HYDROCARBON}

The present invention relates to a method for producing an aromatic hydrocarbon, and more particularly, to a method for simultaneously producing BTX and styrene in one process.

Naphtha Cracking Center (hereinafter referred to as 'NCC') thermally decomposes naphtha, a gasoline fraction, at a temperature of about 950 ° C. to 1,050 ° C. to ethylene, propylene, butylene, and This process produces BTX (Benzene, Toluene, Xylene).

Conventionally, using raw pyrolysis gasoline (RPG), which is a by-product of the process of producing ethylene and propylene using such naphtha as a raw material, BTX and styrene were manufactured through separate processes.

The BTX manufacturing process was largely performed using the RPG raw material stream, including a hydrodesulfurization process (Gasoline Hydrogenation, GHT), a pre-separation process (Prefraction, PF), and an extractive distillation process (EDP). In this case, by supplying the whole amount of the raw material stream to the hydrodesulfurization process (GHT), there was a problem in that the amount of hydrogen used due to an increase in the flow rate supplied to the hydrodesulfurization process (GHT) increases. In addition, the process was complicated because it had to go through pre-separation (PF) to separate benzene, toluene and xylene after the hydrodesulfurization process (GHT). The process was more complicated because the production route from the remaining C8+ hydrocarbons was long.

In addition, the styrene extractive distillation process is a process for directly producing styrene from RPG through an extractive distillation process (EDP) process, and may be located in front of the BTX manufacturing process. At this time, in order to separate the styrene-rich C8 hydrocarbons before supplying the RPG to the EDP, a prefractionation (PF) step of the RPG into C7- hydrocarbons, C8 hydrocarbons and C9+ hydrocarbons is performed in advance. . However, in this case, the separated C7- hydrocarbons and C8 hydrocarbons are mixed again because they are introduced into the BTX manufacturing process and undergo a hydrodesulfurization process (GHT) step. After performing the GHT step, the C7- hydrocarbon and the C8 hydrocarbon are separated again in the BTX manufacturing process. In this way, performing the step of separating the C7- hydrocarbon and the C8 hydrocarbon twice is cost and energy in the process lead to waste

JP 2012-509976 A

The problem to be solved in the present invention is to provide a method of simultaneously manufacturing BTX and styrene in one process, simplifying the process, and saving energy in order to solve the problems mentioned in the technology that is the background of the invention will be.

According to one embodiment of the present invention for solving the above problems, in the present invention, a raw material stream is supplied to a C6 separation column, an overhead stream of the C6 separation column is supplied to the first hydrodesulfurization unit, and the bottom discharge stream is C7 feeding to a separation column; feeding the C7 separation column overhead effluent stream to a first hydrodesulfurization unit and feeding the bottom effluent stream to a C8 separation column; separating benzene and toluene from the first hydrodesulfurization unit effluent stream; removing the bottoms draw stream from the C8 separation column and feeding the top draw stream to a second extractive distillation column; and separating styrene from the second extractive distillation column bottoms stream and separating xylene from the overheads stream.

According to the method for producing an aromatic hydrocarbon of the present invention, BTX and styrene can be simultaneously produced in one process, and in this process, the pre-separation process step, which was a necessary process for BTX production, is omitted to save energy due to reduction in steam usage. can

In addition, only the C7- hydrocarbon stream excluding C8+ hydrocarbons from the raw material stream is supplied to the first hydrodesulfurization unit, thereby reducing the flow rate supplied to the first hydrodesulfurization unit, thereby reducing the amount of hydrogen used in the first hydrodesulfurization unit, and reducing the amount of hydrogen used in the catalyst. It has the effect of increasing the lifespan.

In addition, in order to separate the raw material stream into C8+ hydrocarbons and C7- hydrocarbons, by providing a C6 separation column and a C7 separation column, the C6 separation column and the C7 separation column can be operated at a relatively low temperature, so that the lower temperature of each column is It is lowered to suppress the formation of oligomers and polymers, and it is possible to suppress the generation of fouling in the reboiler installed at the bottom of each column. In addition, energy saving effect can be expected by using a low-grade heat source as a heat source for the reboiler installed below each column, and relatively high temperature cooling water can be used in the condenser installed above each column.

In addition, the process is simplified by removing the pre-separation column and the xylene separation column in the conventional BTX manufacturing process, and by installing the second hydrodesulfurization unit, xylene can be produced directly from the second extractive distillation column overhead stream, so that the existing xylene It can solve the problems of a complex and long production path to produce

In addition, unnecessary processes of re-mixing the second extractive distillation column overheads stream with the C7 separation column overheads stream, hydrodesulphurizing in the first hydrodesulfurization unit, and separating them again are not required by installing the second hydrodesulfurization unit .

1 is a process flow chart according to a method for producing an aromatic hydrocarbon according to Examples 1 to 3 of the present invention.
2 is a process flow chart according to the method for producing an aromatic hydrocarbon according to Comparative Example 1.
3 is a process flow chart according to the method for producing an aromatic hydrocarbon according to Comparative Example 2.
4 is a process flow chart according to the method for producing an aromatic hydrocarbon according to Comparative Example 3.

The terms or words used in the description and claims of the present invention should not be construed as being limited to their ordinary or dictionary meanings, and the inventor must properly understand the concept of the term in order to best describe his invention. Based on the principle that can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

In the present invention, the term 'stream' may mean a flow of a fluid in a process, and may also mean a fluid itself flowing in a pipe. Specifically, the 'stream' may mean both the fluid itself and the flow of the fluid flowing within a pipe connecting each device. In addition, the fluid may refer to a gas or a liquid.

In the present invention, the term 'C# hydrocarbon' in which '#' is a positive integer denotes all hydrocarbons having # carbon atoms. Accordingly, the term 'C8 hydrocarbon' denotes a hydrocarbon compound having 8 carbon atoms. Also, the term 'C#+ hydrocarbon' refers to any hydrocarbon molecule having # or more carbon atoms. Accordingly, the term 'C9+ hydrocarbon' denotes a mixture of hydrocarbons having 9 or more carbon atoms. Also, the term 'C#-hydrocarbon' refers to any hydrocarbon molecule having # or fewer carbon atoms. Accordingly, the term 'C7-hydrocarbons' denotes mixtures of hydrocarbons having up to 7 carbon atoms.

In the present invention, BTX is an abbreviation of benzene, toluene, and xylene, and the xylene is ethyl benzene, m-xylene, o- It may include xylene (o-Xylene) and p-xylene (p-Xylene).

Hereinafter, the present invention will be described in more detail to help the understanding of the present invention.

According to the present invention, there is provided a method for producing an aromatic hydrocarbon. In the method for producing the aromatic hydrocarbon, the BTX and styrene are simultaneously produced in one process, but the process is simplified compared to the conventional case of producing BTX and styrene in each plant, and there is an effect of reducing process energy. have.

Specifically, the conventional BTX manufacturing process was performed using an RPG raw material stream to largely include a hydrodesulfurization process (Gasoline Hydrogenation, GHT), a pre-separation process (Prefraction, PF), and an extractive distillation process (EDP). . In this case, by supplying the whole amount of the raw material stream to the hydrodesulfurization process (GHT), there was a problem in that the amount of hydrogen used due to an increase in the flow rate supplied to the hydrodesulfurization process (GHT) increases. In addition, the process was complicated because it had to go through pre-separation (PF) to separate benzene, toluene and xylene after the hydrodesulfurization process (GHT). The process was more complicated because the production route from the remaining C8+ hydrocarbons was long.

In addition, the conventional styrene extractive distillation process is a process for directly producing styrene from RPG through an extractive distillation process (EDP) process, and may be located in front of the BTX manufacturing process. In order to separate styrene-rich C8 hydrocarbons before feeding the RPG to the extractive distillation process, a pre-separation process step of RPG into C7- hydrocarbons, C8 hydrocarbons and C9+ hydrocarbons is performed in advance. However, the separated C7- hydrocarbons and C8 hydrocarbons are mixed again because they have to be introduced into the BTX manufacturing process and undergo a hydrodesulfurization process step. After performing the hydrodesulfurization process step, the C7- hydrocarbon and the C8 hydrocarbon are separated again in the BTX manufacturing process. In this way, performing the step of separating the C7- hydrocarbon and the C8 hydrocarbon twice is cost and lead to wastage of energy.

As such, conventionally, BTX and styrene were manufactured through each process using RPG. In this case, there are problems such as unnecessary process steps and excessive energy consumption as described above.

In contrast, in the present invention, a process capable of simultaneously producing BTX and styrene, which cannot be technically derived from each process for producing conventional BTX and styrene, is designed, and in this process, the process is more simplified, and the process energy The production of BTX and styrene was maximized compared to the amount of raw materials used while minimizing the use.

According to an embodiment of the present invention, a method for producing an aromatic hydrocarbon may be described with reference to FIG. 1 . As the method for producing the aromatic hydrocarbon, a raw material stream is supplied to a C6 separation column (DeC6), an overheads stream of the C6 separation column (DeC6) is supplied to a first hydrodesulfurization unit (1 ^st GHT), and the bottoms discharge stream is feeding to a C7 separation column (DeC7); separating benzene and toluene from the first hydrodesulfurization unit (1 ^{st GHT) effluent stream;} feeding the C7 separation column (DeC7) overhead stream to a first hydrodesulfurization unit (1 ^st GHT), and feeding the bottom discharge stream to a C8 separation column (DeC8); removing the bottom draw stream from the C8 separation column (DeC8) and feeding the top draw stream to a second extractive distillation column (2 ^nd EDC); and separating styrene from the second extractive distillation column (2 ^nd EDC) bottoms effluent stream and separating xylene from the overhead effluent stream.

According to one embodiment of the present invention, the raw material stream may include pyrolysis gasoline (Raw Pyrolysis Gasoline, RPG). The pyrolysis gasoline may be a by-product of a process of producing ethylene and propylene using naphtha as a raw material among units constituting a naphtha cracking center (NCC). The RPG as the feed stream may be a C5+ hydrocarbon mixture, specifically a mixture rich in C5 hydrocarbons to C10 hydrocarbons. For example, the RPG is, isopentane (Iso-Pentane), normal pentane (n-Pentane), 1,4-pentadiene (1,4-Pentadiene), dimethyl acetylene (Dimethylacetylene), 1-pentene (1- Pentene), 3-methyl-1-butene (3-Methyl-1-butene), 2-methyl-1-butene (2-Methyl-1-butene), 2-methyl-2-butene (2-Methyl-2 -butene), isoprene (Iso-Prene), trans-2-pentene (trans-2-Penstene), cis-2-pentene (cis-2-Penstene), trans-1,3-pentadiene (trans-1, 3-Pentadiene), cyclopentadiene (Cyclopentadiene), cyclopentane (Cyclopentane), cyclopentene (Cyclopentene), normal hexane (n-Hexane), cyclohexane (Cyclohexane), 1,3-cyclohexadiene (1,3- cyclohexadiene), normal heptane (n-Heptane), 2-methylhexane (2-methmethylh), 3-methylhexane (3-methylhexane), normal octane (n-Octane), normal nonane (n-Nonane), benzene (Benzene) ), toluene, ethylbenzene, m-xylene, o-xylene, p-xylene, styrene, dicyclo It may include one or more selected from the group consisting of pentadiene (Dicyclopentadiene), indene (Indene), and indane (Indane).

According to an embodiment of the present invention, in order to efficiently produce BTX and styrene from the feed stream including the C5 hydrocarbon to C10 hydrocarbon, the feed stream is separated into C7- hydrocarbons and C8+ hydrocarbons. At this time, the stream including C7- hydrocarbons may be a stream for producing benzene and toluene, and the stream including C8+ hydrocarbons may be a stream for producing styrene and xylene.

According to an embodiment of the present invention, a C6 separation column (DeC6) and a C7 separation column (DeC7) are provided in order to separate the raw material stream into C7- hydrocarbons and C8+ hydrocarbons. Specifically, the feed stream is fed to a C6 separation column (DeC6), and the overheads stream containing C6- hydrocarbons from the C6 separation column (DeC6) is fed to a first hydrodesulfurization unit, and a bottoms discharge containing C7+ hydrocarbons. The stream was fed to a C7 separation column (DeC7). In addition, in the C7 separation column (DeC7), a top discharge stream containing C7 hydrocarbons and a bottom discharge stream containing C8+ hydrocarbons are separated, and the top discharge stream containing C7 hydrocarbons is a first hydrodesulfurization unit (1 ^st) GHT) and the bottoms effluent stream comprising C8+ hydrocarbons is fed to a C8 separation column (DeC8). At this time, the C6 separation column (DeC6) overhead discharge stream and the C7 separation column (DeC7) overhead discharge stream are respectively ^{supplied to the first hydrodesulfurization unit (1 st} GHT), or a mixed stream mixed in an arbitrary area. As may be supplied to the first hydrodesulfurization unit (1 ^{st GHT).}

As a result, the feed stream passes through a C6 separation column (DeC6) and a C7 separation column (DeC7) and can be divided into a stream containing C7- hydrocarbons and a stream containing C8+, and the stream containing C7- hydrocarbons is It may be fed to a first hydrodesulfurization unit (1 ^st GHT) to produce benzene and toluene, and a stream containing C8+ hydrocarbons may be fed to a C8 separation column (DeC8) to produce styrene and xylene.

In addition, the C6 separation column (DeC6) can be recycled in the C6 separation column (DeC6) used in the pre-separation step in the existing BTX manufacturing process.

A flow ratio of the C6 separation column (DeC6) overhead effluent stream and the C7 separation column (DeC7) overhead effluent stream may be 0.3:1 to 5:1, 0.5:1 to 2.5:1, or 0.5:1 to 2:1. By controlling the flow rate of the overhead stream of the C6 separation column (DeC6) and the C7 separation column (DeC7) within this range, the C6 separation column (DeC6) and the C7 separation column (DeC7) are operated at a relatively low temperature while C7- hydrocarbons are removed. The stream containing C8+ hydrocarbons can be effectively separated. The operating temperature of the C6 separation column (DeC6) and the C7 separation column (DeC7) is 140° C. or less, 70° C. to 130° C., or 80° C. to 120° C., respectively. °C. Specifically, since the boiling point range of the components of the raw material stream is wide, the raw material stream is separated using only a C7 separation column (DeC7) to separate an overhead effluent stream containing C7- hydrocarbons and a bottom effluent stream containing C8+ hydrocarbons. There was a problem in that the upper and lower temperature ranges of the C7 separation column (DeC7) separation column should be set widely. However, as in the present application, the C6 separation column (DeC6) used in the pre-separation step of the existing BTX manufacturing process is recycled and divided into two C6 separation columns (DeC6) and C7 separation column (DeC7) to separate the raw material stream, each column It is possible to reduce the temperature range of the upper and lower parts of the Through this, it is possible to reduce the amount of steam used in each column. In addition, by operating each of the C6 separation column (DeC6) and the C7 separation column (DeC7) at a low temperature within the above range, the lower temperature of each column is lowered to suppress the production of oligomers and polymers, and the C6 separation column (DeC6) and C7 separation It is possible to suppress the generation of fouling in the reboiler installed under each of the columns DeC7. In addition, according to this, it is possible to extend the washing cycle of the reboiler installed under each of the C6 separation column (DeC6) and the C7 separation column (DeC7), and accordingly, the C6 separation column (DeC6) and the C7 separation column (DeC7) column, respectively It is also possible to extend the operation period of the system to reduce the loss that occurs when the operation is stopped.

A reboiler may be installed under each of the C6 separation column DeC6 and the C7 separation column DeC7, and steam may be used as a heat source in the reboiler. At this time, as described above, by operating the C6 separation column (DeC6) and the C7 separation column (DeC7) at 140° C. or less, the C6 separation column (DeC6) and the C7 separation column (DeC7) each reboiler generates low-grade steam It can be used as a heat source. For example, the temperature of the low-grade steam may be 150 ° C. or less, 80 ° C. to 140 ° C. or 90 ° C. to 140 ° C., and the supply pressure may be 5 KG or less, 0.5 KG to 4 KG, or 1 KG to 3 KG. As such, by using low-grade steam as a heat source in the reboiler of the C6 separation column (DeC6) and the C7 separation column (DeC7), energy consumption can be reduced.

In addition, a condenser may be installed on each of the C6 separation column (DeC6) and the C7 separation column (DeC7), and in the condenser, a relatively high temperature cooling water (Chilled Water) as a refrigerant instead of expensive (Chilled Water) Cooling Water) can be used. Specifically, the temperature of the capacitor installed on each of the C6 separation column (DeC6) and the C7 separation column (DeC7) may be 40 °C to 70 °C, 40 °C to 60 °C, or 40 °C to 50 °C. For example, a partial stream of the overhead discharge stream of the C6 separation column (DeC6) is supplied to a condenser installed at the top of the C6 separation column (DeC6) and condensed at a temperature of 40 °C to 70 °C to C6 separation column (DeC6) , and the remaining stream may be discharged and supplied to the first hydrodesulfurization unit (1st GHT). In addition, a partial stream of the upper discharge stream of the C7 separation column (DeC7) is supplied to a condenser installed at the top of the C7 separation column (DeC7), is condensed at a temperature of 40 °C to 70 °C, and refluxed to the C7 separation column (DeC7) and the remaining stream may be discharged and supplied to the first hydrodesulfurization unit (1st GHT). At this time, by controlling the temperature of the capacitor installed on each of the C6 separation column (DeC6) and the C7 separation column (DeC7) to 40 °C to 70 °C, 5 °C cooled using a separate refrigerator as a refrigerant in the condenser Cooling water of about 25 °C to 35 °C may be used instead of chilled water of about 10 °C to 10 °C.

According to an embodiment of the present invention, the upper discharge stream of each of the C6 separation column (DeC6) and the C7 separation column (DeC7 ^{) is supplied to the first hydrodesulfurization unit (1 st} GHT) to separately supply hydrogen and the presence of a catalyst It may be subjected to a hydrodesulfurization process step of hydrodesulfurization under The catalyst may be a catalyst capable of selective hydrogenation. For example, the catalyst may include at least one selected from the group consisting of palladium, platinum, copper, and nickel. In some cases, the catalyst may be used by being supported on at least one carrier selected from the group consisting of gamma alumina, activated carbon, and zeolite.

According to an embodiment of the present invention, it may be prepared by separating benzene and toluene from ^{the first hydrodesulfurization unit (1 st GHT) discharge stream.} Specifically, the first hydrodesulfurization unit (1 ^st GHT) benzene and toluene, the outlet stream of claim 1 from the extractive distillation column (1 ^st EDC) of the first extractive distillation column (1 ^st EDC) a lower outlet stream supply, and the each can be separated.

More specifically, the first hydrodesulfurization unit (1 ^st GHT) may include a first hydrodesulfurization reactor and a second hydrodesulfurization reactor, and the top discharge of the C6 separation column (DeC6) and the C7 separation column (DeC7) The stream is fed to a first hydrodesulphurization reactor, the first hydrodesulfurization reactor effluent stream is fed to a second hydrodesulphurization reactor, and the second hydrodesulphurization reactor effluent stream is fed to a first extractive distillation column (1 ^st EDC) And, benzene and toluene may be separated from the first extractive distillation column (1 ^st EDC) bottom discharge stream, respectively. At this time, the second hydrodesulfurization reactor outlet stream may be fed to ^{a first extractive distillation column (1 st EDC) after passing through a stripper.}

In addition, the first hydrodesulfurization unit (1 ^st GHT) may further include a separately required device in addition to the first hydrodesulfurization reactor and the second hydrodesulfurization reactor. For example, the first hydrodesulfurization unit (1 ^st GHT) may further include a C5 separation column, and the C5 separation column may be located between the first hydrodesulfurization reactor and the second hydrodesulfurization reactor. Through this, the C6 separation column (DeC6) and C7 separation column (DeC7) overhead stream passes through the first hydrodesulfurization unit (1 ^st GHT), and the C6 separation column (DeC6) and C7 separation column (DeC7) overhead discharge stream Impurities such as C5 hydrocarbons and fuel gas (F/G) may be removed from the stream.

The operating temperature of the first hydrodesulfurization reactor may be 50 °C to 200 °C, 60 °C to 170 °C or 60 °C to 140 °C. The first hydrodesulfurization reactor may be operated at a temperature within the above range, whereby the hydrogenation reaction may proceed in a liquid phase. Specifically, in the first hydrodesulfurization reactor, a hydrogenation reaction may be performed in a liquid phase at a low temperature to remove olefins. For example, the olefin is a hydrocarbon having a double bond, and may include styrene and diolefin. These olefins may be converted into saturated hydrocarbons by breaking a double bond due to a hydrogenation reaction in the first hydrodesulfurization reactor.

The operating temperature of the second hydrodesulfurization reactor may be 250 °C to 400 °C, 280 °C to 360 °C, or 280 °C to 320 °C. The second hydrodesulfurization reactor may be operated at a temperature within the above range, whereby the hydrogenation reaction may proceed in the gas phase. Specifically, in the second hydrodesulfurization reactor, the residual olefin that has not been removed in the first hydrodesulfurization reactor may be removed, and a hydrogenation reaction may be performed in a gas phase to remove sulfur. Through this, the second hydrodesulfurization reactor effluent stream from which olefins and sulfur are removed may be fed to ^{the first extractive distillation column (1 st EDC) in whole volume after passing through a stripper without additional pre-separation.}

Specifically, in the case of the conventional BTX manufacturing process, the entire raw material stream undergoes hydrodesulfurization, and columns for the pre-separation process and a xylene separation column (MX) are required to separate benzene, toluene, and xylene therefrom. , even if the conventional BTX manufacturing process and the styrene extractive distillation process are theoretically combined, it is impossible to remove the pre-separation columns and the xylene separation column (MX). However, in the present invention, only the C6 separation column (DeC6) overhead effluent stream and the C7 separation column (DeC7) overhead effluent stream, that is, the stream containing C7-hydrocarbons, have passed through the ^{first hydrodesulfurization unit (1 st GHT).} A separate pre-separation is not required, and a xylene separation column (MX) is also not required due ^{to a second hydrodesulfurization unit (2 nd GHT) to be described later.}

According to an embodiment of the present invention, a raw material stream including C5 and C6 hydrocarbons may be separately supplied to ^{the first hydrodesulfurization unit (1 st GHT).} In this case, the raw material stream supplied to the first hydrodesulfurization unit (1 ^st GHT) may not include styrene. For example, a feed stream comprising C5 and C6 hydrocarbons separately supplied to the first hydrodesulfurization unit (1 ^st GHT) is a bottoms outlet stream of a C4 separation column (not shown) in the NCC process, cyclopentadiene, pentadiene , isoprene, cyclopentene, 1-pentene, 3-methyl-1-butene, cyclopentane, 2-methyl-butene, normalpentane, benzene, and may include at least one selected from the group consisting of C6 non-aromatic hydrocarbons. Conventionally, the C4 separation column bottoms effluent stream is mixed with the RPG described above and used as a feed stream for the BTX manufacturing process and the styrene manufacturing process. However, since the C4 separation column bottom discharge stream contains benzene and does not contain styrene, when supplied to the C6 separation column (DeC6), additional processes such as unnecessary separation and mixing are performed. Accordingly, in the present invention, the C4 separation column (not shown) bottom discharge stream is separately ^{supplied to the first hydrodesulfurization unit (1 st} GHT) to reduce the flow rate supplied to the C6 separation column (DeC6), and unnecessary process steps are not performed. did not save energy.

The content of the olefin in the feed stream separately supplied to the first hydrodesulfurization unit (1 ^st GHT) may be 40 wt% or more, 40 wt% to 70 wt%, or 40 wt% to 60 wt%.

According to an embodiment of the present invention, the ^{stream discharged from the first hydrodesulfurization unit (1 st} GHT) may include C6 aromatic hydrocarbons and C7 aromatic hydrocarbons. As a specific example, the first hydrodesulfurization unit (1 ^st GHT) discharge stream may be a stream rich in benzene and toluene, which may be ^{supplied to the first extractive distillation column (1 st} EDC) to undergo an extraction process.

In the first extractive distillation column (1 ^st EDC), benzene and toluene may be separated from the discharge stream of the first hydrodesulfurization unit (1 ^{st GHT) by using an extraction solvent.} For example, the extraction solvent is at least one selected from the group consisting of sulfolane, alkyl-sulfolane, N-formyl morpholine, N-methyl pyrrolidone, tetraethylene glycol, triethylene glycol, and diethylene glycol. may include In addition, the extraction solvent may further include water as a co-solvent.

In the first extractive distillation column (1 ^st EDC), aromatic hydrocarbons and non-aromatic hydrocarbons in the first hydrodesulfurization unit (1 ^{st GHT) discharge stream may be separated using an extraction solvent.} Specifically, the first extractive distillation column (1 ^st EDC) first hydrodesulfurization unit (1 ^st GHT) outlet stream by selective extraction of the aromatic hydrocarbons in the exhaust to lower the first extractive distillation column (1 ^st EDC), Non-aromatic hydrocarbons may be separated from the top of the first extractive distillation column (1 ^{st EDC).}

A separately required device may be further included at the rear end of the first extractive distillation column (1 ^{st EDC).} For example, the first extractive distillation column (1 ^st EDC) bottom discharge stream is an extract, and may contain an extraction solvent along with an aromatic hydrocarbon. Accordingly, the bottom discharge stream of the first extractive distillation column (1 ^st EDC) may be separated into an extraction solvent and an aromatic hydrocarbon while passing through a separate solvent recovery column.

The first extractive distillation column (1 ^st EDC) bottoms draw stream, for example, the first extractive distillation column (1 ^st EDC) bottoms draw stream comprising aromatic hydrocarbons separated via a solvent recovery column, is then It passes through a separation column and a toluene separation column (TOL), and through this, ^{benzene and toluene may be separated from the first extractive distillation column (1 st} EDC) bottom discharge stream, respectively. For example, the first extractive distillation column (1 ^st EDC) bottoms effluent stream is fed to a benzene separation column (BZ) to separate benzene (BZ) from the top of the benzene separation column (BZ), and the benzene separation column (BZ) The bottom draw stream may be fed to a toluene separation column (TOL) to separate toluene (TOL) from the top, and the remaining trace C8+ hydrocarbon heavy material may be discharged from the bottom.

According to an embodiment of the present invention, the C7 separation column (DeC7) bottoms discharge stream is supplied to the C8 separation column (DeC8) as a stream containing C8+ hydrocarbons, and the C8 separation column (DeC8) contains C8 hydrocarbons. It may be separated into a top effluent stream and a bottoms effluent stream comprising C9+ hydrocarbons. At this time, the stream containing the C9+ hydrocarbon is removed by discharging to the outside through the C8 separation column (DeC8) bottom discharge stream, hydrodesulphurizing the components not required in the BTX manufacturing process, and removing after separation unnecessary process can be removed.

According to an embodiment of the present invention, the C8 separation column (DeC8) overhead stream containing the C8+ hydrocarbons ^{may be supplied to a second extractive distillation column (2 nd} EDC) to undergo an extraction process.

In the second extractive distillation column (2 ^nd EDC), an aromatic hydrocarbon and a vinyl aromatic hydrocarbon may be separated from the C8 separation column (DeC8) overhead effluent stream using an extraction solvent. Specifically, in the second extractive distillation column (2 ^nd EDC), styrene-rich C8 vinyl aromatic hydrocarbons in the C8 separation column (DeC8) overhead effluent stream are selectively extracted and separated into the bottom of ^{the second extractive distillation column (2 nd EDC)} and xylene-rich C8 aromatic hydrocarbons can be separated over ^{a second extractive distillation column (2 nd EDC).} In this case, the extraction solvent is, for example, one selected from the group consisting of sulfolane, alkyl-sulfolane, N-formyl morpholine, N-methyl pyrrolidone, tetraethylene glycol, triethylene glycol, and diethylene glycol. It may include more than one species. In addition, the extraction solvent may further include water as a co-solvent.

The second extractive distillation column (2 ^nd EDC) may separate styrene from the bottom draw stream, and separate ^{xylene from the second extractive distillation column (2 nd} EDC) top draw stream, respectively.

A device separately required may be further included at the rear end of the second extractive distillation column (2 ^{nd EDC).} For example, the second extractive distillation column (2 ^nd EDC) bottoms outlet stream is an extract, and may contain an extraction solvent along with C8 vinyl aromatic hydrocarbons. Accordingly, the second extractive distillation column (2 ^nd EDC) bottom discharge stream may be separated into an extraction solvent and a C8 vinyl aromatic hydrocarbon while passing through a separate solvent recovery column, through which the C8 vinyl aromatic hydrocarbon, that is, styrene is separated can do.

The second extractive distillation column (2 ^nd EDC) overhead stream is a stream including xylene-rich C8 aromatic hydrocarbons, and may ^{pass through a second hydrodesulfurization unit (2 nd} GHT) to produce xylene. Specifically, in the second hydrodesulfurization unit (2 ^nd GHT), residual olefins and sulfur in the second extractive distillation column (2 ^nd EDC) overhead stream may be removed by hydrogenation, and the second hydrodesulfurization unit (2 ^nd) Xylene (MX) can be produced directly from the second extractive distillation column (2 ^{nd EDC) overheads stream passed through GHT).}

The second hydrodesulfurization section (2 ^nd GHT) may be subjected to a hydrodesulfurization process comprising hydrodesulfurization reaction in the presence of hydrogen and a catalyst is fed separately from said hydrogen and a catalyst. The catalyst may be a catalyst capable of selective hydrogenation. For example, the catalyst may include at least one selected from the group consisting of palladium, platinum, copper, and nickel. In some cases, the catalyst may be used by being supported on at least one carrier selected from the group consisting of gamma alumina, activated carbon, and zeolite.

The second hydrodesulfurization unit (2 ^nd GHT), unlike the first hydrodesulfurization unit (1 ^st GHT), does not include two hydrodesulfurization reactors, and is provided with only one third hydrodesulfurization reactor, so the size of the plant can be reduced and energy use can be minimized. Specifically, the second extractive distillation column (2 ^nd EDC) overhead stream fed to the third hydrodesulphurization reactor contains xylene-rich C8 aromatic hydrocarbons, and olefins such as styrene and diolefins are hardly present. Therefore, the hydrogenation reaction for removing the olefin through the liquid phase reaction at a low temperature can be omitted. For example, the content of the olefins contained in the second extractive distillation column (2 ^nd EDC) overhead effluent stream may be 0.1 wt% or less or 0.01 wt% to 0.1 wt%.

Specifically, the second extractive distillation column (2 ^nd EDC) overhead effluent stream is fed to a third hydrodesulfurization reactor, and in the third hydrodesulfurization reactor, from 250 °C to 400 °C, 280 °C to 360 °C or 280 °C to The hydrogenation reaction may proceed at a temperature of 320 °C. The third hydrodesulfurization reactor may be operated at a temperature within the above range, whereby the hydrogenation reaction may proceed in the gas phase. Specifically, in the third hydrodesulfurization reactor, ^{residual olefins in the second extractive distillation column (2 nd} EDC) overhead stream are removed, and a hydrogenation reaction may be performed in a gas phase to remove sulfur. In this way, olefins and desulfurized xylene-rich C8 aromatic hydrocarbons are discharged from the third hydrodesulphurization reactor, and xylene (MX) can be produced without further separation from the third hydrodesulphurization reactor discharge stream.

On the other hand, even if the conventional BTX manufacturing process and the styrene extractive distillation process are theoretically combined, the stream containing the C8 aromatic hydrocarbon separated in the styrene extractive distillation process, that is, the second extractive distillation column (2 ^nd EDC) overhead stream will be fed to the ^{first hydrodesulfurization unit (1 st} GHT) as a raw material for the BTX manufacturing process together with a C6 separation column (DeC6) overhead effluent stream and a C7 separation column (DeC7) overhead effluent stream. In this case, due to an increase in the flow rate supplied to the first hydrodesulfurization unit (1 ^st GHT), there is a problem in that the amount of hydrogen used increases and the life of the catalyst is reduced. In addition, the second extractive distillation column (2 ^nd EDC) overheads stream contains a very small amount of olefins, so that both the first hydrodesulfurization reactor and the second hydrodesulfurization reactor like the first ^{hydrodesulfurization unit (1 st GHT) are used.} This leads to unnecessary use of energy. In addition, since the stream discharged from the first hydrodesulfurization unit (1 ^st GHT) includes C8 aromatic hydrocarbons as well as C6 aromatic hydrocarbons and C7 aromatic hydrocarbons, the rear end of the ^{first hydrodesulfurization unit (1 st GHT) discharge stream} There is a problem in that a line separation column and a xylene separation column (MX) are additionally required to separate them.

According to an embodiment of the present invention, in the method for producing an aromatic hydrocarbon, if necessary, a distillation column (not shown), a condenser (not shown), a reboiler (not shown), a valve (not shown), a pump (not shown), Devices such as a separator (not shown) and a mixer (not shown) may be additionally installed.

As mentioned above, although the method for producing an aromatic hydrocarbon according to the present invention has been shown in the description and drawings, the description and drawings above describe and show only the essential components for understanding the present invention, and the description and drawings shown in the description and drawings In addition to the process and apparatus, processes and apparatus not separately described and not shown may be appropriately applied and used for carrying out the method for producing an aromatic hydrocarbon according to the present invention.

Hereinafter, the present invention will be described in more detail by way of Examples. However, the following examples are intended to illustrate the present invention, and it is apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention, and the scope of the present invention is not limited thereto.

Example

Example One

With respect to the process flow diagram shown in FIG. 1, the process was simulated using Aspen Plus simulator of Aspen Corporation.

Specifically, a feed stream comprising C5 to C10 hydrocarbons is supplied to a C6 separation column (DeC6), and a feed stream comprising C5 and C6 hydrocarbons without styrene is fed to a first hydrodesulfurization unit (1 ^st GHT). supplied.

The C6 separation column (DeC6) overhead stream comprising C6- hydrocarbons is fed to the first hydrodesulfurization unit (1 ^st GHT), and the bottoms draw stream comprising C7+ hydrocarbons is fed to the C7 separation column (DeC7). In addition, in the C7 separation column (DeC7), the overheads stream containing C7 hydrocarbons ^{is supplied to the first hydrodesulfurization unit (1 st} GHT), and the bottoms discharge stream containing C8+ hydrocarbons is supplied to the C8 separation column (DeC8). did At this time, the flow ratio of the C6 separation column (DeC6) overhead stream and the C7 separation column (DeC7) overhead stream was controlled to be 1.36:1.

The C6 separation column (DeC6) overhead effluent stream containing C6-hydrocarbons and the C7 separation column (DeC7) overhead effluent stream containing C7 hydrocarbons are fed to a first hydrodesulfurization unit (1 ^st GHT), and the C6 aromatic hydrocarbons and the first hydrodesulfurization unit (1 ^st GHT) effluent stream comprising C7 aromatic hydrocarbons was fed to the whole first extractive distillation column (1 ^{st EDC).}

The first extractive distillation column (1 ^st EDC) bottom discharge stream contains C6 and C7 aromatic hydrocarbons, and is a stream from which non-aromatic hydrocarbons are removed, and is supplied to a benzene separation column (BZ), and the benzene separation column (BZ) Benzene was separated from the top and the bottom effluent stream was fed to a toluene separation column (TOL). In the toluene separation column (TOL), toluene was separated from the top and heavy materials including C8+ hydrocarbons were separated and removed from the bottom.

The C7 separation column (DeC7) bottoms discharge stream containing C8+ hydrocarbons is supplied to a C8 separation column (DeC8), and the bottoms discharge stream containing C9+ hydrocarbons from the C8 separation column (DeC8) is discharged and removed to the outside, The C8 separation column (DeC8) overheads stream containing the C8 hydrocarbons was fed to a second extractive distillation column (2 ^nd EDC).

The bottom discharge stream of the second extractive distillation column (2 ^nd EDC) contains styrene, and is supplied to a solvent recovery column to remove the solvent, and then styrene is separated.

Further, the second extracting a distillation column (2 ^nd EDC) an upper outlet stream is rich in xylene stream, the second hydrogenation was supplied to the desulfurization unit (2 ^nd GHT), wherein the second hydrodesulfurization section (2 ^nd GHT) discharge Xylene was produced from the stream.

In the process simulation, the flow rate (ton/hr) of the stream according to the process flow is shown in Table 1 below. In addition, the total amount of steam used in the process was measured as the total energy usage in the process, and it is shown in Table 2 below as a reference (100.0) for the total steam usage used in the remaining examples and comparative examples.

Example 2

The same process as in Example 1 was performed, except that the feed stream containing C5 and C6 hydrocarbons without styrene was supplied to the C6 separation column (DeC6) instead ^{of the first hydrodesulfurization unit (1 st GHT).} .

As a result of the process simulation, the flow rate (ton/hr) of the stream according to the process flow is shown in Table 1 below. In addition, as the total energy consumption in the process, the total amount of steam used in the process was measured, and it is shown in Table 2 below as a relative amount compared to the amount of steam used in Example 1 of 100.0.

Example 3

The same process as in Example 1 was performed, except that the flow ratio of the C6 separation column (DeC6) overhead stream and the C7 separation column (DeC7) overhead stream was controlled to be 4:1.

As a result of the process simulation, the flow rate (ton/hr) of the stream according to the process flow is shown in Table 1 below. In addition, as the total energy consumption in the process, the total amount of steam used in the process was measured, and it is shown in Table 2 below as a relative amount compared to the amount of steam used in Example 1 of 100.0.

comparative example

comparative example One

With respect to the process flow diagram shown in FIG. 2, the process was simulated using Aspen Plus simulator of Aspen Corporation.

Specifically, a feed stream containing C5 to C10 hydrocarbons as a feed stream ^{was supplied to a first hydrodesulfurization unit (1 st} GHT), and the first hydrodesulfurization unit (1 ^st GHT) output stream was transferred to a C6 separation column (DeC6). supplied with From the C6 separation column (DeC6), a top draw stream comprising C6 aromatic hydrocarbons ^{is fed to a first extractive distillation column (1 st} EDC), and a bottom draw stream comprising C7+ aromatic hydrocarbons is fed to a C9 separation column (DeC9). did

From the C9 separation column (DeC9), a bottoms effluent stream comprising C8+ aromatic hydrocarbons is fed to a xylene separation column (MX), and a stream comprising C7 and C8 aromatic hydrocarbons is combined with a C6 separation column (DeC6) overhead effluent stream. It was fed to a first extractive distillation column (1 ^{st EDC).}

The bottom discharge stream of the first extractive distillation column (1 ^st EDC) contains C6 to C8 aromatic hydrocarbons, and passes through a benzene separation column (BZ) and a toluene separation column (TOL) to separate benzene and toluene, and the remaining The stream was fed to a xylene separation column (MX).

In the xylene separation column (MX), a bottom effluent stream containing C9+ hydrocarbons was removed, and xylene was separated from the top.

As a result of the process simulation, the flow rate (ton/hr) of the stream according to the process flow is shown in Table 1 below.

comparative example 2

With respect to the process flow diagram shown in FIG. 3, the process was simulated using Aspen Plus simulator of Aspen Corporation.

Specifically, a feed stream comprising C5 to C10 hydrocarbons is supplied to a C6 separation column (DeC6), and a feed stream comprising C5 and C6 hydrocarbons without styrene is fed to a first hydrodesulfurization unit (1 ^st GHT). supplied.

The C6 separation column (DeC6) overhead stream comprising C6- hydrocarbons is fed to the first hydrodesulfurization unit (1 ^st GHT), and the bottoms draw stream comprising C7+ hydrocarbons is fed to the C7 separation column (DeC7). In addition, in the C7 separation column (DeC7), the overheads stream containing C7 hydrocarbons ^{is supplied to the first hydrodesulfurization unit (1 st} GHT), and the bottoms discharge stream containing C8+ hydrocarbons is supplied to the C8 separation column (DeC8). did At this time, the flow ratio of the C6 separation column (DeC6) overhead stream and the C7 separation column (DeC7) overhead stream was controlled to be 1.36:1.

The bottom effluent stream containing C9+ hydrocarbons from the C8 separation column (DeC8) was discharged to the outside and removed, and the C8 separation column (DeC8) top effluent stream containing C8 hydrocarbons was transferred to a second extractive distillation column (2 ^nd EDC). supplied.

The bottom discharge stream of the second extractive distillation column (2 ^nd EDC) contains styrene, and is supplied to a solvent recovery column to remove the solvent, and then styrene is separated.

The top effluent stream of the second extractive distillation column (2 ^nd EDC) includes xylene, and together with the C6 separation column (DeC6) and C7 separation column (DeC7) overhead effluent stream, the first hydrodesulfurization unit (1 ^st) GHT).

The first hydrodesulfurization unit (1 ^st GHT) discharge stream includes C6 to C8 aromatic hydrocarbons and is supplied to a C6 separation column (DeC6). The C6 separation column (DeC6) is divided into a top draw stream comprising C6 aromatic hydrocarbons and a bottom draw stream comprising C7 and C8 aromatic hydrocarbons, and the C6 separation column (DeC6) overhead draw stream is a first extractive distillation column (1). ^st EDC) and the bottoms effluent stream is fed to a xylene separation column (MX).

In the xylene separation column (MX), a top draw stream comprising C7 aromatic hydrocarbons is fed together with the C6 separation column (DeC6) overhead draw stream to a first extractive distillation column (1 ^st EDC), and xyl from the bottom draw stream Ren was produced.

The first extractive distillation column (1 ^st EDC) bottom discharge stream passes through a benzene separation column (BZ) and a toluene separation column (TOL) to separate benzene and toluene, respectively, and the remaining stream is a xylene separation column (MX). supplied.

As a result of the process simulation, the flow rate (ton/hr) of the stream according to the process flow is shown in Table 1 below. In addition, as the total energy consumption in the process according to each Example, the total amount of steam used in the process was measured, and it is shown in Table 2 below as a relative amount compared to the amount of steam used in Example 1 of 100.0.

comparative example 3

With respect to the process flow diagram shown in FIG. 4, the process was simulated using Aspen Plus simulator of Aspen Corporation.

Specifically, the same process as in Comparative Example 2 was performed, except that a bottom discharge stream containing C9+ hydrocarbons from the C8 separation column (DeC8) was transferred to the C6 separation column (DeC6) top discharge stream and the C7 separation column (DeC7) top It was fed to the first hydrodesulfurization unit (1 ^st GHT) together with the effluent stream and the second extractive distillation column (2 ^{nd EDC) overhead effluent stream.}

As a result of the process simulation, the flow rate (ton/hr) of the stream according to the process flow is shown in Table 1 below. In addition, as the total energy consumption in the process according to each Example, the total amount of steam used in the process was measured, and it is shown in Table 2 below as a relative amount compared to the amount of steam used in Example 1 of 100.0.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 S1 20.4 N/A 20.4 183.8 20.4 20.4 S2 163.6 184.0 163.6 N/A 163.6 163.6 S11 119.4 119.4 119.4 119.8 119.4 119.4 S12 88.4 88.4 88.4 89.6 88.4 88.4 S13 64.6 64.6 64.6 64.6 64.6 64.6 S14 23.4 23.4 23.4 23.4 23.4 23.4 S21 70.0 80.0 97.0 N/A 70.0 70.0 S22 93.6 104.0 66.6 N/A 93.6 93.6 S23 51.6 62.2 24.4 N/A 51.6 51.6 S24 42.0 42.0 42.0 N/A 42.0 42.0 S25 19.4 19.4 19.4 N/A 19.4 19.4 S26 9.6 9.6 9.6 N/A 9.6 9.6 S27 9.6 9.6 9.6 N/A N/A N/A S28 9.6 9.6 9.6 N/A N/A N/A S30 N/A N/A N/A 161.4 129.0 151.6 S31 N/A N/A N/A 106.4 113.4 112.8 S32 N/A N/A N/A 55.0 N/A 38.8 S33 N/A N/A N/A 41.6 N/A 32.2 S34 N/A N/A N/A 13.4 N/A 6.6 S35 N/A N/A N/A 1.6 0.4 0.4 S36 N/A N/A N/A 19.0 10.0 10.0 S37 N/A N/A N/A N/A 15.6 N/A S38 N/A N/A N/A N/A 6.0 N/A S40 N/A N/A N/A N/A 9.6 9.6 S41 22.6 22.6 22.6 N/A 22.6 22.6

Example 1 Example 2 Example 3 Comparative Example 2 Comparative Example 3 Total Steam Usage 100.0 103.6 101.9 116.3 123.0

* Total steam usage: Ratio of the relative total steam usage compared to the reference (Example 1: 100.0)

Referring to Tables 1 and 2, in the case of Examples 1 to 3 for producing BTX and styrene by the method according to the present invention, the total production of benzene, toluene, xylene, and srene was equal to or superior to that of Comparative Example. it can be seen that

In particular, in the case of Example 1, it can be seen that the total amount of steam used for heating in the process is the lowest compared to the remaining Examples and Comparative Examples. Specifically, in Example 1, the raw material stream containing C5 and C6 hydrocarbons without styrene is not supplied to the C7 separation column (DeC7), but ^{is separately supplied to the first hydrodesulfurization unit (1 st} GHT), and the The flow ratio of the C6 separation column (DeC6) overhead effluent stream and the C7 separation column (DeC7) overhead effluent stream was controlled to be 0.5:1 to 2:1. Through this, by optimizing the flow rate of the raw material stream supplied to the C6 separation column (DeC6) and the flow rate of the stream supplied to the first hydrodesulfurization unit (1 ^st GHT) while maintaining the purity of each component high, energy consumption was minimized. . In comparison, in Example 2, it can be seen that the stream supplied to the C6 separation column (DeC6) is increased, so that the amount of steam used is slightly increased, and in Example 3, the flow rate of the C6 separation column (DeC6) overhead stream is increased, so that the steam It can be seen that the usage has slightly increased.

In comparison, Comparative Example 1 does not produce styrene and is not a comparison target as a process for manufacturing only BTX, so comparative data on the total amount of steam used was not added. However, said Since the stream supplied to the first hydrodesulfurization unit (1 ^st GHT) is the largest at 183.8 ton/hr, the amount of hydrogen ^{used in the first hydrodesulfurization unit (1 st} GHT) is significantly large, and the life of the catalyst is reduced. There is a problem with increasing utility costs.

Also, in Comparative Example 2, the second extractive distillation column (2 ^nd EDC) overhead stream was separated from the example in which xylene was produced using the overhead stream separated in the second extractive distillation column (2 ^nd EDC). by charging into a first hydrodesulfurization unit (1 ^st GHT), a problem of increase in the stream supplied to the first hydrodesulfurization unit (1 ^st GHT) is hydrogen amount increases and decreases the life of the catalyst to increase the utility cost have. In addition, since C8 hydrocarbons are introduced into the BTX manufacturing process, the C6 separation column (DeC6) and the xylene separation column (MX) for pre-separation in the BTX manufacturing process are not removed, thereby increasing the amount of steam used.

^{In addition, Comparative Example 3 is a first hydrodesulfurization unit (1 st} GHT) from the second extractive distillation column (2 ^nd EDC) overheads effluent stream to the effluent stream to the bottom of the stream C8 separation column (DeC8) containing C9+ hydrocarbons. By input, there is a problem in that the stream supplied to the first hydrodesulfurization unit (1 ^st GHT) increases, the amount of hydrogen used increases, and the lifespan of the catalyst decreases, thereby increasing utility costs. In addition, since C8+ hydrocarbons are introduced into the BTX manufacturing process, the C6 separation column (DeC6), C9 separation column (DeC9), and xylene separation column (MX) for pre-separation in the BTX manufacturing process are not removed. There is a growing problem.

1 ^st GHT: first hydrodesulfurization unit
2 ^nd GHT: second hydrodesulfurization unit
1 ^st EDC: first extractive distillation column
2 ^nd EDC: second extractive distillation column
BZ: Benzene separation column
TOL: toluene separation column
MX: xylene separation column
DeC6: C6 separation column
DeC7: C7 separation column
DeC8: C8 separation column
DeC9: C9 separation column

Claims (13)

the feed stream is fed to the C6 separation column, the top draw stream of the C6 separation column is fed to the first hydrodesulfurization unit, and the bottom draw stream is fed to the C7 separation column;
feeding the C7 separation column overhead effluent stream to a first hydrodesulfurization unit and feeding the bottom effluent stream to a C8 separation column;
separating benzene and toluene from the first hydrodesulfurization unit effluent stream;
removing the bottoms draw stream from the C8 separation column and feeding the top draw stream to a second extractive distillation column; and
and separating styrene from the second extractive distillation column bottoms effluent stream and separating xylene from the overhead effluent stream. According to claim 1,
The raw material stream is a method for producing aromatic hydrocarbons comprising C5 hydrocarbons to C10 hydrocarbons. According to claim 1,
The flow ratio of the C6 separation column overheads stream to the C7 separation column overheads stream is 0.3:1 to 5:1. According to claim 1,
The flow ratio of the C6 separation column overheads stream to the C7 separation column overheads stream is 0.5:1 to 2:1. According to claim 1,
Steam is used as a heat source in the reboiler installed under each of the C6 separation column and the C7 separation column,
The steam supply pressure is 5 KG or less of the method for producing an aromatic hydrocarbon. According to claim 1,
The temperature of the capacitor installed on each of the C6 separation column and the C7 separation column is 40 ℃ to 70 ℃ method for producing an aromatic hydrocarbon. According to claim 1,
The first hydrodesulfurization unit effluent stream is fed to a first extractive distillation column, and benzene and toluene are separated from the first extractive distillation column bottoms effluent stream. According to claim 1,
wherein the second extractive distillation column overheads stream comprises C8 aromatic hydrocarbons and the bottoms draw stream comprises C8 vinyl aromatic hydrocarbons. According to claim 1,
wherein the second extractive distillation column overheads stream is fed to a second hydrodesulfurization unit, and xylene is separated from the second hydrodesulfurization unit discharge stream. 10. The method of claim 9,
The second hydrodesulfurization unit includes a third hydrodesulfurization reactor,
The operating temperature of the third hydrodesulfurization reactor is a method for producing an aromatic hydrocarbon of 250 ℃ to 350 ℃. According to claim 1,
wherein the C8 separation column bottoms draw stream comprises C9+ hydrocarbons. According to claim 1,
The first hydrodesulfurization unit discharge stream comprises C6 aromatic hydrocarbons and C7 aromatic hydrocarbons. According to claim 1,
A feed stream comprising C5 hydrocarbons and C6 hydrocarbons is separately supplied to the first hydrodesulfurization unit,
The raw material stream supplied to the first hydrodesulfurization unit is a method for producing an aromatic hydrocarbon that does not contain styrene.

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