KR20130108319A - Method for manufacturing aromatic hydrocarbon - Google Patents

Abstract

In the method for producing an aromatic hydrocarbon, the crude oil having a 10 vol% outlet temperature of 140 ° C. or higher and a 90 vol% outlet temperature of 380 ° C. or lower is brought into contact with a catalyst for producing a monocyclic aromatic hydrocarbon containing crystalline aluminosilicate and reacted. The monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms and the heavy distillate having 9 or more carbon atoms are obtained from the decomposition reforming reaction step of obtaining a product containing 6 to 8 monocyclic aromatic hydrocarbons and heavy distillate having 9 or more carbon atoms, and the product obtained in the decomposition reforming reaction step. Naphthalene which separates and recovers naphthalenes from the separation | separation process which isolate | separates, the refinery | recovery recovery process which refine | purifies and collects the C6-C8 monocyclic aromatic hydrocarbon isolate | separated in the separation process, and the heavy distillate containing 9 or more carbon atoms separated by the separation process. It has a recovery process.

Description

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

The present invention relates to a process for producing aromatic hydrocarbons.

This application claims priority based on Japanese Patent Application No. 2010-205903 for which it applied to Japan on September 14, 2010, and uses the content here.

Light cycle oil (hereinafter referred to as "LCO"), which is a cracked light oil produced in a fluid catalytic cracking (hereinafter referred to as "FCC") apparatus, has been used as light oil or heavy oil, including many polycyclic aromatic hydrocarbons. However, in recent years, it has been studied to obtain monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms (for example, benzene, toluene, xylene, ethylbenzene, etc.) having high octane number gasoline bases and petrochemical raw materials from LCO, and having high added value. It is becoming.

For example, Patent Documents 1 to 3 propose a method of producing monocyclic aromatic hydrocarbons from polycyclic aromatic hydrocarbons contained in many LCOs and the like using a zeolite catalyst.

Japanese Patent Publication No. 3-2128 Japanese Patent Laid-Open No. 3-52993 Japanese Patent Publication No. 3-26791

However, in the method of patent documents 1-3, the yield of the C6-C8 monocyclic aromatic hydrocarbon was not high enough.

In recent years, further effective utilization of LCO is expected. Specifically, in addition to efficiently producing monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms, such as benzene, toluene, xylene, and ethylbenzene, other chemicals can be produced as effective by-products simply by adding the same process or some new process. It is expected to be possible.

The present invention has been made in view of the above circumstances, and an object thereof is to produce monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms in high yield from raw oil containing polycyclic aromatic hydrocarbons, For example, the present invention provides a method for producing an aromatic hydrocarbon capable of producing an aromatic hydrocarbon other than the monocyclic aromatic hydrocarbon.

MEANS TO SOLVE THE PROBLEM This inventor acquired the following knowledge as a result of earnestly examining in order to achieve the said objective.

Since LCO contains many polycyclic aromatic hydrocarbons, when this decomposition-reaction reaction process is carried out, relatively heavy heavy distillate which has 9 or more carbon atoms is obtained besides the C6-C8 monocyclic aromatic hydrocarbon. About this heavy distillate, it was only examined that it collect | recovers as a light oil and kerosene base material, or recycles as a raw material of the said monocyclic aromatic hydrocarbon.

Therefore, the present inventors have analyzed the components in detail in order to effectively utilize the heavy distillate, and found that the heavy distillate contains a lot of naphthalene and alkylnaphthalene. Based on these findings, further studies have been conducted on the production of naphthalene as a chemical product in parallel with the production of the above monocyclic aromatic hydrocarbons. As a result, the present invention has been completed.

That is, the manufacturing method of the aromatic hydrocarbon of this invention,

A raw material oil having a 10 volume% outlet temperature of 140 ° C. or higher and a 90 volume% outlet temperature of 380 ° C. or lower is brought into contact with a catalyst for producing a monocyclic aromatic hydrocarbon containing crystalline aluminosilicate and reacted with a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms. And a cracking reforming reaction step of obtaining a product including a heavy distillate having 9 or more carbon atoms,

A separation step of separating the monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms and the heavy distillate having 9 or more carbon atoms from the product obtained in the decomposition reforming reaction step, respectively;

A purification recovery step of purifying and recovering a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms separated in the separation step;

And a naphthalene recovery step of separating and recovering naphthalenes containing at least naphthalene from the heavy distillate having 9 or more carbon atoms separated in the separation step.

Moreover, it is preferable that the said method of manufacturing an aromatic hydrocarbon is the process in which the said naphthalene recovery process isolate | separates and collects methylnaphthalene and / or dimethylnaphthalene and naphthalene.

Moreover, the manufacturing method of the said aromatic hydrocarbon,

A hydrogenation reaction step of hydrogenating the remaining distillate from the separation of naphthalenes in the naphthalene recovery step to obtain a hydrogenation reactant;

It is preferable to have a recycling process for returning the hydrogenation reactant to the decomposition reforming reaction process.

In the method for producing an aromatic hydrocarbon, in the naphthalene recovery step, the means for separating and recovering the naphthalenes containing naphthalene is preferably a means using a distillation apparatus.

Moreover, in the manufacturing method of the said aromatic hydrocarbon, it is preferable that the said crystalline aluminosilicate has a microporous zeolite and / or a macroporous zeolite as a main component.

Moreover, in the manufacturing method of the said aromatic hydrocarbon, it is preferable to make reaction temperature at the time of making the said raw material oil and the said catalyst for monocyclic aromatic hydrocarbon manufacture in the said decomposition reforming reaction process into 400 degreeC or more and 650 degrees C or less.

Moreover, in the manufacturing method of the said aromatic hydrocarbon, it is preferable to make reaction pressure at the time of making the said raw material oil and the said monocyclic aromatic hydrocarbon production catalyst react in the said decomposition | reformation reforming reaction process be 0.1 MPaG or more and 1.5 MPaG or less.

Moreover, in the manufacturing method of the said aromatic hydrocarbon, it is preferable to make the contact time for making the said raw material oil and the said catalyst for monocyclic aromatic hydrocarbon manufacture in the said decomposition reforming reaction process into 1 second or more and 300 seconds or less.

According to the method for producing an aromatic hydrocarbon of the present invention, monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms can be produced from a crude oil containing polycyclic aromatic hydrocarbons in a relatively high yield, and naphthalenes containing naphthalene as other chemical products are also present. It can manufacture.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating one Embodiment of the manufacturing method of the aromatic hydrocarbon of this invention.

Hereinafter, the manufacturing method of the aromatic hydrocarbon of this invention is demonstrated in detail.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating one Embodiment of the manufacturing method of the aromatic hydrocarbon of this invention, The manufacturing method of the aromatic hydrocarbon of this embodiment produces a C6-C8 monocyclic aromatic hydrocarbon from raw material oil, and is naphthalene. It is a method of manufacturing naphthalenes containing these.

That is, the manufacturing method of the aromatic hydrocarbon of this embodiment is as shown in FIG.

(a) a cracking reforming reaction step of contacting the raw material oil with a catalyst for producing a monocyclic aromatic hydrocarbon and reacting to obtain a product containing a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms and a heavy distillate having at least 9 carbon atoms,

(b) a separation step of separating the product produced in the cracking reforming reaction step into a plurality of distillates,

(c) a hydrogen recovery step of recovering hydrogen by-produced in the decomposition reforming reaction step from the gas component separated in the separation step,

(d) an LPG recovery process for recovering LPG by-produced in the decomposition reforming reaction step from the liquid distillate separated in the separation step;

(e) a purification recovery step of purifying and recovering monocyclic aromatic hydrocarbons from the liquid distillate separated in the separation step;

(f) a naphthalene recovery step of separating and recovering naphthalenes containing at least naphthalene from a heavy distillate having 9 or more carbon atoms obtained from the liquid distillate separated in the separation step;

(g) a hydrogen supply step of supplying hydrogen recovered in the hydrogen recovery step to a hydrogenation reaction step,

(h) a hydrogenation step of hydrogenating the remaining distillate from the separation of naphthalenes in a naphthalene recovery step, and

(i) a recycling step of returning the hydrogenation reactant obtained in the hydrogenation reaction step to a decomposition reforming step;

It is desirable to have

In addition, in the process of said (a)-(i), the process of (a), (b), (e), (f) is an essential process in the invention which concerns on Claim 1 of this application, and other processes are arbitrary It is a process.

Hereinafter, each process will be described in detail.

Decomposition Reforming Reaction Process

In the cracking reforming reaction step, the crude oil is brought into contact with a catalyst for producing a monocyclic aromatic hydrocarbon, the saturated hydrocarbon contained in the crude oil is used as a hydrogen donor, and the polycyclic aromatic hydrocarbon is partially hydrogenated and ring-opened by hydrogen transfer reaction from the saturated hydrocarbon. Convert to aromatic hydrocarbons. In addition, it is also possible to convert to a monocyclic aromatic hydrocarbon by cyclization and dehydrogenation of the saturated hydrocarbon obtained in the raw material oil or in the decomposition process. Further, by decomposing the monocyclic aromatic hydrocarbon having 9 or more carbon atoms, the monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms can also be obtained. As a result, a product containing a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms and a heavy distillate having 9 or more carbon atoms is obtained. This product also includes hydrogen, methane, ethane, ethylene, LPG (propane, propylene, butane, butene, etc.) in addition to monocyclic aromatic hydrocarbons and heavy distillates. In addition, a lot of naphthalene, methylnaphthalene, and dimethyl naphthalene are contained in heavy distillate. In addition, in this application, these naphthalene, methylnaphthalene, and dimethyl naphthalene are named generically, and it describes as "naphthalene."

In this decomposition reforming reaction step, components such as naphthenobenzenes, paraffins, and naphthenes in the crude oil can be lost by producing monocyclic aromatic hydrocarbons, and the polycyclic aromatic hydrocarbons are cleaved of alkyl side chains at the same time as the conversion to monocyclic aromatic hydrocarbons. This makes it possible to obtain high value-added naphthalenes having few side chains such as naphthalene, methylnaphthalene and dimethylnaphthalene. That is, in this decomposition reforming reaction step, monocyclic aromatic hydrocarbons can be produced in high yield, and other components having a boiling point close to naphthalenes can be reduced as much as possible. Therefore, the naphthalenes mentioned later can be efficiently recovered by increasing the amount of naphthalenes having short side chains and increasing the content of naphthalenes in the decomposition reforming reaction product oil.

In addition, although naphthylenes were originally contained in the cracked light oil etc. which are illustrated as a main raw material oil, many other components, such as naphthenobenzenes and paraffins, are contained at the same time. Therefore, the content rate of naphthalenes is small with respect to whole raw material oil, and it is very difficult to isolate | separate and refine naphthalene directly from raw material oil. If the separation and purification of naphthalenes directly from the raw material oil is carried out, it is not preferable to adopt an energy somewhat non-type process such as crystallization.

This decomposition reforming process makes it possible to significantly improve the ratio of recovering useful aromatic hydrocarbons as described above.

(Raw oil)

The raw material oil used by this embodiment is oil whose 10 volume% outflow temperature is 140 degreeC or more, and 90 volume% outflow temperature is 380 degreeC or less. In an oil having a 10% by volume distillation temperature of less than 140 ° C, monocyclic aromatic hydrocarbons are produced from the hard ones, which becomes unsuitable for the well-known embodiment. In addition, in the case of using an oil having a 90 vol.% Outlet temperature exceeding 380 ° C., the yield of monocyclic aromatic hydrocarbons is lowered, and the amount of coke deposition on the catalyst for monocyclic aromatic hydrocarbon production increases, causing a sharp decrease in catalyst activity. There is a tendency.

It is preferable that 10 volume% outflow temperature of raw material oil is 150 degreeC or more, and it is preferable that 90 volume% outflow temperature of raw material oil is 360 degrees C or less. On the other hand, there is no particular limitation on the upper limit of the 10 vol.% Effluent temperature of the raw material oil and the lower limit of the 90 vol.% Effluent temperature, but since the C 6-8 monocyclic aromatic hydrocarbons and naphthalenes can be efficiently produced, 10 vol. As for temperature, 210 degreeC or less and 90 volume% outflow temperature are preferable 240 degreeC or more.

In addition, the 10 volume% outflow temperature and 90 volume% outflow temperature here mean the value measured based on JISK2254 "petroleum product-distillation test method."

Examples of the raw material oil having a 10 vol% outlet temperature of 140 ° C. or higher and a 90 vol% outlet temperature of 380 ° C. or lower include, for example, other decomposition light oils such as LCO, LCO hydrorefined oil, hydrocracked light oil and pyrolysis light oil produced in an FCC unit, Coal liquefied oil, heavy oil hydrocracking refined oil, direct current kerosene, direct current gas oil, coker kerosene, coker light oil and oil sand hydrocracking refined oil, etc. are mentioned.

In addition, since the yield of monocyclic aromatic hydrocarbons falls when a lot of polycyclic aromatic hydrocarbons are contained in raw material oil, 50 volume% or less of content (polycyclic aromatic content) of polycyclic aromatic hydrocarbon in raw material oil is more preferable, and it is 40 volume% or less desirable. However, when it is going to raise the yield of naphthalene (or naphthalenes) manufactured with monocyclic aromatic hydrocarbon as mentioned later, the polycyclic aromatic component in raw material oil can also be 50 volume% or more, for example. However, also in that case, it is preferable to make content of a tricyclic or more aromatic hydrocarbon into 30 volume% or less, and it is more preferable to set it as 15 volume% or less.

In addition, polycyclic aromatic content here is bicyclic aromatic hydrocarbon content measured by JPI-5S-49 "petroleum product-hydrocarbon type test method-high-speed liquid chromatograph method" or analyzed by FID gas chromatograph method (2 rings Aromatic content) and the sum total of 3 or more rings of aromatic hydrocarbon content (3 or more rings of aromatic content). Then, when content of polycyclic aromatic hydrocarbon, bicyclic aromatic hydrocarbon, and tricyclic or more aromatic hydrocarbon is represented by volume%, it is based on JPI-5S-49 method and FID gas chromatograph method when represented by mass%. It is measured.

(Response format)

As a reaction form when a raw material oil is contacted and made to react with the catalyst for monocyclic aromatic hydrocarbon manufacture, a fixed bed, a mobile bed, a fluidized bed, etc. are mentioned. In this embodiment, since a heavy component is used as a raw material, the fluidized bed which can remove the coke powder adhering to a catalyst continuously and can react stably is preferable. In particular, a continuous regenerative fluidized bed in which the catalyst is circulated between the reactor and the regenerator and the reaction-regeneration can be repeated continuously is particularly preferred. It is preferable that the raw material oil at the time of contact with the catalyst for monocyclic aromatic hydrocarbon production is in a gaseous state. In addition, a raw material can also be diluted with a gas as needed.

(Catalyst for producing monocyclic aromatic hydrocarbons)

Catalysts for monocyclic aromatic hydrocarbon production contain crystalline aluminosilicates.

Crystalline Aluminosilicate

Since crystalline aluminosilicate can make the yield of monocyclic aromatic hydrocarbon higher, it is preferable that they are a microporous zeolite and / or a macroporous zeolite.

The mesoporous zeolite is a zeolite having a skeleton structure of 10 membered rings, and examples of the mesoporous zeolite include AEL, EUO, FER, HEU, MEL, MFI, NES, TON, and WEI crystal structures. Zeolite is mentioned. Among these, MFI type is preferable because the yield of monocyclic aromatic hydrocarbon can be made higher.

The macroporous zeolite is a zeolite having a 12-membered skeleton structure, and examples of the macroporous zeolite include AFI type, ATO type, BEA type, CON type, FAU type, GME type, LTL type, MOR type, MTW type and OFF type. The zeolite of a crystal structure is mentioned. Among these, BEA type is preferable because the total yield of monocyclic aromatic hydrocarbons and aliphatic hydrocarbons having 3 to 4 carbon atoms can be made higher.

However, when it is going to raise the yield of naphthalene (or naphthalenes) manufactured with monocyclic aromatic hydrocarbon as mentioned later, what contains crystalline aluminosilicate other than the said MFI type or BEA zeolite can also be used.

The crystalline aluminosilicate may also contain small pore zeolites having a skeletal structure of 10-membered rings or less, and superporous zeolites having a skeletal structure of 14-membered rings or more, in addition to the mesoporous zeolite and the large pore zeolites.

Here, as small pore zeolite, zeolite of ANA type, CHA type, ERI type, GIS type, KFI type, LTA type, NAT type, PAU type, and YUG type crystal structure is mentioned, for example.

As a super pore zeolite, the zeolite of a CLO type and a VPI type crystal structure is mentioned, for example.

When making a decomposition reforming reaction process into a fixed phase reaction, 60-100 mass% of the crystalline aluminosilicate in the catalyst for monocyclic aromatic hydrocarbon production is preferably 100 mass% when the whole catalyst for monocyclic aromatic hydrocarbon production is 100 mass%, 70-100 mass% is more preferable, and 90-100 mass% is especially preferable. When content of crystalline aluminosilicate is 60 mass% or more, the yield of monocyclic aromatic hydrocarbon can be made high enough. Moreover, the yield of naphthalene can also be made comparatively high.

When making a decomposition reforming reaction process fluid reaction, 20-60 mass% of the crystalline aluminosilicate in the catalyst for monocyclic aromatic hydrocarbon production is preferable when the whole catalyst for monocyclic aromatic hydrocarbon production is 100 mass%, 30-60 mass% is more preferable, and 35-60 mass% is especially preferable. When content of crystalline aluminosilicate is 20 mass% or more, the yield of monocyclic aromatic hydrocarbon can be made high enough. Moreover, the yield of naphthalene can also be made comparatively high. Moreover, when content of crystalline aluminosilicate exceeds 60 mass%, content of the binder which can be mix | blended with a catalyst may become small and it may become unsuitable for fluid bed use.

[Phosphorus, boron]

In the catalyst for monocyclic aromatic hydrocarbon production, it is preferable to contain phosphorus and / or boron. When the catalyst for monocyclic aromatic hydrocarbon production contains phosphorus and / or boron, the time-dependent fall of the yield of monocyclic aromatic hydrocarbon can be prevented, and the coke formation on the catalyst surface can be suppressed.

As a method for containing phosphorus in the catalyst for monocyclic aromatic hydrocarbon production, for example, a method in which phosphorus is supported on crystalline aluminosilicate or crystalline alumino silicate or crystalline alumino zinc silicate by ion exchange method, impregnation method, zeolite The method of containing a phosphorus compound at the time of synthesis | combination, and substituting a part in the skeleton of crystalline aluminosilicate with phosphorus, the method of using the crystal promoter containing phosphorus at the time of zeolite synthesis | combination, etc. are mentioned. Although it does not specifically limit as a phosphate ion containing aqueous solution used at that time, The thing manufactured by dissolving phosphoric acid, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, another water-soluble phosphate, etc. in arbitrary concentration can be used preferably.

As a method for containing boron in the catalyst for monocyclic aromatic hydrocarbon production, for example, a method in which boron is supported on crystalline aluminosilicate or crystalline alumino silicate or crystalline alumino zinc silicate by ion exchange method, impregnation method, zeolite The method which contains a boron compound at the time of synthesis | combination, and replaces a part in the skeleton of crystalline aluminosilicate with boron, the method of using the crystal promoter containing boron at the time of zeolite synthesis, etc. are mentioned.

It is preferable that content of phosphorus and / or boron in the catalyst for monocyclic aromatic hydrocarbon manufacture is 0.1-10 mass% with respect to a catalyst total weight, Furthermore, a minimum is 0.5 mass% or more, and an upper limit is 9 mass% or less More preferably, 8 mass% or less is especially preferable. When content of phosphorus and / or boron with respect to catalyst total weight is 0.1 mass% or more, the fall of the yield of monocyclic aromatic hydrocarbon can be prevented over time, and the yield of monocyclic aromatic hydrocarbon can be made high by 10 mass% or less.

[Gallium, zinc]

The catalyst for monocyclic aromatic hydrocarbon production may contain gallium and / or zinc as needed. By containing gallium and / or zinc, the production | generation ratio of monocyclic aromatic hydrocarbon can be made higher.

As a gallium-containing form in the catalyst for monocyclic aromatic hydrocarbon production, gallium is inserted into the lattice skeleton of crystalline aluminosilicate (crystalline alumino silicate), and gallium is supported on crystalline aluminosilicate (gallium supported Crystalline aluminosilicate) and those containing both.

As a zinc-containing form in the catalyst for monocyclic aromatic hydrocarbon production, zinc is inserted into the lattice skeleton of crystalline aluminosilicate (crystalline alumina zinc silicate), and zinc is supported on crystalline aluminosilicate (zinc supported). Crystalline aluminosilicate) and those containing both.

Crystalline alumino silicate and crystalline alumino zinc silicate have a structure in which SiO ₄ , AlO ₄ and GaO ₄ / ZnO ₄ structures exist in the skeleton. In addition, crystalline alumino silicate and crystalline alumino silicate are, for example, gel crystallization by hydrothermal synthesis, a method of inserting gallium or zinc into the lattice skeleton of crystalline aluminosilicate, or crystalline gallosilicate or It is obtained by the method of inserting aluminum into the lattice skeleton of crystalline zinc silicate.

Gallium-supported crystalline aluminosilicate is obtained by supporting gallium on crystalline aluminosilicate by known methods such as ion exchange and impregnation. Although it does not specifically limit as a gallium source used at that time, Gallium salts, such as gallium nitrate and a gallium chloride, a gallium oxide etc. are mentioned.

Zinc-supported crystalline aluminosilicate is one in which zinc is supported on crystalline aluminosilicate by known methods such as ion exchange and impregnation. Although it does not specifically limit as a zinc source used at that time, Zinc salts, such as zinc nitrate and zinc chloride, zinc oxide, etc. are mentioned.

When the catalyst for monocyclic aromatic hydrocarbon production contains gallium and / or zinc, it is preferable that content of gallium and / or zinc in the catalyst for monocyclic aromatic hydrocarbon production is 0.01-5.0 mass% when the whole catalyst is 100 mass%, It is more preferable that it is 0.05-1.5 mass%. When content of gallium and / or zinc is 0.01 mass% or more, the production | generation ratio of monocyclic aromatic hydrocarbon can be made more, and if it is 5.0 mass% or less, the yield of monocyclic aromatic hydrocarbon can be made higher.

[shape]

The catalyst for monocyclic aromatic hydrocarbon production is, for example, powdery, granular or pelletized depending on the reaction type. For example, in the case of a fluidized bed, it becomes powder form, and in the case of a fixed bed, it becomes a granular form or a pellet form. 30-180 micrometers is preferable and, as for the average particle diameter of the catalyst used in a fluidized bed, 50-100 micrometers is more preferable. The bulk density of the catalyst used in the fluidized bed is preferably 0.4 to 1.8 g / cc, more preferably 0.5 to 1.0 g / cc.

In addition, an average particle diameter shows the particle diameter which becomes 50 mass% in the particle size distribution obtained by classification by a sieve, and a bulk density is the value measured by the method of JIS standard R9301-2-3.

When obtaining a granular or pellet shaped catalyst, what is necessary is just to mix | blend an inert oxide with a catalyst as a binder as needed, and to shape using various shaping machines.

When the catalyst for monocyclic aromatic hydrocarbon production contains inorganic oxides, such as a binder, you may use what contains phosphorus as a binder.

(Reaction temperature)

Although it does not restrict | limit especially about reaction temperature at the time of making a raw material oil contact and react with the catalyst for monocyclic aromatic hydrocarbon manufacture, It is preferable to set it as 400-650 degreeC, and it is more preferable to set it as 450-650 degreeC. If reaction temperature is 400 degreeC or more, raw material oil can be made to react easily. Moreover, when reaction temperature is 450 degreeC or more and 650 degrees C or less, the yield of monocyclic aromatic hydrocarbon can be made high enough, and also the yield of naphthalene can also be made relatively high.

(Reaction pressure)

The reaction pressure at the time of contacting and reacting the raw material oil with the catalyst for monocyclic aromatic hydrocarbon production is preferably 1.5 MPaG or less, and more preferably 1.0 MPaG or less. If the reaction pressure is 1.5 MPaG or less, by-products of the hard gas can be suppressed and the pressure resistance of the reaction apparatus can be lowered. Moreover, if it is 0.1 MPaG or more and 1.5 MPaG or less, the yield of monocyclic aromatic hydrocarbon can be made high enough, and also the yield of naphthalene can be made relatively high.

(Contact time)

The contact time between the raw material oil and the catalyst for monocyclic aromatic hydrocarbon production is not particularly limited as long as the desired reaction proceeds substantially. For example, 1 to 300 seconds is preferable as the gas passage time on the catalyst for monocyclic aromatic hydrocarbon production. It is more preferable to set an upper limit to 150 seconds for 5 seconds. If the contact time is 1 second or more, the reaction can be reliably performed. If the contact time is 300 seconds or less, the accumulation of carbonaceous material in the catalyst due to caulking or the like can be suppressed. Alternatively, the amount of hard gas generated by decomposition can be suppressed. Moreover, the yield of monocyclic aromatic hydrocarbon can be made high enough, and also the yield of naphthalene can be made relatively high.

<Separation process>

In the separation process, the product produced in the decomposition reforming reaction process is separated into a plurality of distillates.

In order to isolate | separate into several distillation components, you may use a well-known distillation apparatus and gas-liquid separation apparatus. As an example of a distillation apparatus, what can distill separation of a some distillate with a multistage distillation apparatus like a stripper is mentioned. As an example of a gas-liquid separation apparatus, a gas-liquid separation tank, the product introduction pipe which introduces the said product into the said gas-liquid separation tank, the gas component outflow pipe provided in the upper part of the said gas-liquid separation tank, and the liquid component outflow pipe provided in the lower part of the said gas-liquid separation tank What is provided is mentioned.

In the separation step, at least the gas component and the liquid distillate are preferably separated, and the liquid distillate may be further separated into a plurality of distillates. As an example of a separation process, there exists a form which isolates mainly by the gas component containing a C4 or less component (for example, hydrogen, methane, ethane, LPG, etc.), and a liquid distillate. Moreover, there exists a form which isolate | separates into the gas component and liquid distillate containing a C2 or less component (for example, hydrogen, methane, ethane) as a separation process. Further, as the separation step, there is a form in which the liquid distillate is further divided into LPG, distillation containing a monocyclic aromatic hydrocarbon, and heavy distillation. Moreover, as a separation process, the form which separates the said liquid distillate further into LPG (for example, propylene, propane, butene, butane, etc.), the distillation containing monocyclic aromatic hydrocarbon, the some heavy distillation, etc. is mentioned. Can be. In the case of employing a fluidized bed as a reaction type in the decomposition reforming reaction step, the catalyst powder to be mixed may also be removed in this step. However, about heavy distillate, naphthalenes may be isolate | separated independently, and also the heavy distillate may be integrated and classified without dividing into several. It is preferable that the boiling range of the distillate containing the C6-C8 monocyclic aromatic hydrocarbon is 78 degreeC-150 degreeC, and the boiling point range of the heavy distillate containing mainly naphthalene is 210 degreeC-270 degreeC.

<Tablet recovery process>

The purification | recovery recovery process refine | purifies and collects C6-C8 monocyclic aromatic hydrocarbon obtained by the separation process.

In this purification and recovering step, the liquid distillate is sufficiently classified in the separation step, and when the C6-C8 monocyclic aromatic hydrocarbon is separated into benzene / toluene / xylene, a step of purifying and recovering each is employed. In addition, when it classifies as a C6-C8 monocyclic aromatic hydrocarbon, it classifies, and after recovering this monocyclic aromatic hydrocarbon, it isolate | separates into benzene / toluene / xylene, and refine | purifies and collect | recovers each after that is employ | adopted.

In the separation step, when the liquid distillate is not well classified and contains a large amount of distillate other than the monocyclic aromatic hydrocarbon when the C6-8 monocyclic aromatic hydrocarbon is recovered, the distillate is separated. For example, it can also be made to supply to the hydrogenation reaction process and naphthalene collection | recovery process mentioned later. In particular, it is preferable to supply to the naphthalene collection | recovery process about distillate (heavy distillate with 9 or more carbon atoms) heavier than the said monocyclic aromatic hydrocarbon among distillates other than monocyclic aromatic hydrocarbon. This is because the heavy distillate having 9 or more carbon atoms has a polycyclic aromatic hydrocarbon as a main component, and particularly contains a lot of naphthalene and alkylnaphthalene.

<Naphthalene recovery process>

The naphthalene recovery step separates and recovers naphthalenes containing at least naphthalene from a heavy distillate having 9 or more carbon atoms obtained from the liquid distillate separated in the separation step.

In this naphthalene recovery step, when the heavy distillate separated in the separation step is separated into a heavy distillate mainly containing naphthalenes and other heavy distillates, the heavy distillate including naphthalenes is purified. Naphthalenes are separated and recovered. In the separating step, when distilled fractions containing naphthalenes are classified without being divided into plural heavy distillate fractions having 9 or more carbon atoms, specifically, naphthalenes including naphthalene, methylnaphthalene, dimethylnaphthalene, The mixture is separated by other distillates, and at least naphthalenes containing naphthalene are purified and recovered.

In addition, in order to separate heavy distillate into a some distillate, you may use the well-known distillation apparatus (distillation tower) used at the said separation process.

Since the component having the boiling point close to the naphthalene in the decomposition reforming reaction product oil was greatly reduced by passing through the decomposition reforming reaction step, in the present naphthalene recovery step, only the known distillation apparatus used in the separation step was used. Naphthalene can be separated and purified to high purity. For example, it is possible to purify and recover naphthalene to about 80-98% of purity. In addition, the recovered naphthalene purity is determined by the number of components having a boiling point close to the remaining naphthalene in the decomposition reforming reaction step, the amount of the components produced, and the performance of the distillation apparatus. When naphthalene is recovered with 95% or more of purity, it is generally possible to treat it as a product having a commercial value circulating as crude naphthalene, and for purity of less than 95%, for example, about 80 to 95%, Purification treatment is performed to increase the purity to 95% or more, thereby making it possible to obtain crude naphthalene as a chemical product. In addition, even in distilled powder having a purity of 95% or more, further purification can be performed to obtain higher purity naphthalene. As purification means in this case, crystallization etc. are mentioned, for example.

In the naphthalene recovery step, if only naphthalene can be separated and recovered, naphthalenes other than naphthalene may be integrated to separate and purify and recover alkylnaphthalene or separately as methylnaphthalene, dimethylnaphthalene, or the like. In this case, methylnaphthalene and dimethylnaphthalene are refine | purified to about 80 to 95% of purity, respectively, and are collect | recovered. Then, it refine | purifies to the purity requested | required as a chemical product.

Here, in this naphthalene collection | recovery process, distillate other than naphthalene, methylnaphthalene, and dimethyl naphthalene made into the objective is also obtained. This distillate is sent out of the system and, for example, is subjected to a purification or the like as necessary, and is then used as a light oil and kerosene base material. Or it is sent to the hydrogenation reaction process mentioned later, and is recycled through this process.

In addition, in this embodiment shown in FIG. 1, the naphthalene collection | recovery process becomes one process. In the naphthalene recovery step, first, a step of separating and recovering naphthalene from a heavy distillate having 9 or more carbon atoms is provided, followed by a plurality of steps such as providing a step of classifying and recovering methylnaphthalene, dimethylnaphthalene, and the like, respectively. , Methylnaphthalene and dimethylnaphthalene may be classified and recovered, respectively. In addition, about distillate other than these, it becomes a light oil and kerosene base material as mentioned above, or is provided for recycling to raw material oil through a hydrogenation reaction process.

Hydrogenation Reaction Process

In this hydrogenation reaction step, a part or all of the remaining distillate separated from the naphthalenes in the naphthalene recovery step is supplied to this hydrogenation step to hydrogenate it. Here, when only naphthalene is separated and recovered in the naphthalene recovery step and no alkylnaphthalene such as methylnaphthalene or dimethylnaphthalene is separated and recovered, these alkylnaphthalenes become the above-mentioned "distilled fraction from which naphthalenes are separated" to be hydrogenated. To be supplied. In addition, the remaining distillate obtained by separating naphthalenes which have not been supplied to the hydrogenation reaction step may be used as a fuel base material such as light oil and kerosene.

Specifically, in the naphthalene recovery step, the remaining distillate and hydrogen are separated from the naphthalene and supplied to the hydrogenation reactor, and at least a part of the polycyclic aromatic hydrocarbons contained in the remaining distillate from the separation of the naphthalene using a hydrogenation catalyst is hydrogenated. .

Although it does not specifically limit about a polycyclic aromatic hydrocarbon, It is preferable to hydrogenate until an aromatic ring becomes one or less on average. When hydrogenated until an aromatic ring becomes one or less on average, when it returns to a decomposition reforming reaction process, it can convert into monocyclic aromatic hydrocarbon easily.

Moreover, in order to improve the yield of especially monocyclic aromatic hydrocarbon further, it is preferable to make content of the polycyclic aromatic hydrocarbon in the hydrogenation reactant obtained by a hydrogenation reaction process into 20 mass% or less, and to make it 10 mass% or less. It is preferable that content of the polycyclic aromatic hydrocarbon in a hydrogenation reactant is smaller than content of the polycyclic aromatic hydrocarbon of raw material oil, and it can reduce as the amount of hydrogenation catalyst increases and reaction pressure increases.

However, it is not necessary to hydroprocess all of the polycyclic aromatic hydrocarbons until it becomes a saturated hydrocarbon. Excess hydrogenation tends to cause an increase in hydrogen consumption and an increase in calorific value.

In addition, in order to give priority to the yield improvement of naphthalene (naphthalenes) rather than the yield improvement of monocyclic aromatic hydrocarbon, it is preferable to make content of the polycyclic aromatic hydrocarbon in the hydrogenation reactant obtained by a hydrogenation reaction process 20 mass% or more.

In the present embodiment, it is also possible to use byproducts produced in the decomposition reforming reaction step as hydrogen. That is, hydrogen is recovered from the gas component obtained in the separation step in the hydrogen recovery step described later, and hydrogen recovered in the hydrogen supply step is supplied to the hydrogenation reaction step.

As the reaction type in the hydrogenation step, a stationary phase is preferably employed.

As the hydrogenation catalyst, a known hydrogenation catalyst (for example, a nickel catalyst, a palladium catalyst, a nickel-molybdenum catalyst, a cobalt-molybdenum catalyst, a nickel-cobalt-molybdenum catalyst, a nickel-tungsten catalyst, etc.) can be used.

Although reaction temperature changes also with the hydrogenation catalyst to be used, it is usually 100-450 degreeC, More preferably, it is 200-400 degreeC, More preferably, it is the range of 250-380 degreeC.

Although the reaction pressure changes also with the hydrogenation catalyst and raw material used, it is preferable to set it as the range of 0.7 MPa-13 MPa, It is more preferable to set it as 1 MPa-10 MPa, It is especially preferable to set it as 1 MPa-7 MPa. When the reaction pressure is 13 MPa or less, a hydrogenation reactor having a low service pressure can be used, thereby reducing the equipment cost.

On the other hand, it is preferable that reaction pressure is 0.7 Mpa or more from the point of the yield of hydrogenation reaction.

Hydrogen consumption is more preferably not more than 3000scfb (506Nm ³ / m ³⁾ or less is preferred ^{and, 2500scfb (422Nm 3 / m 3} ) and more preferably not more ^{than, 1500scfb (253Nm 3 / m 3} ).

On the other hand, the hydrogen consumption is preferably ³⁰⁰ sccfb (50 Nm ³ / m ³ ) or more in terms of the yield of the hydrogenation reaction.

The liquid space velocity (LHSV) is more preferably that is less desirable and, 0.2h ^-1 to 10h ^-1 or more or less than 0.1h ^-1 20h ^-1. When the LHSV is set to 20 h ⁻¹ or less, the polycyclic aromatic hydrocarbon can be sufficiently hydrogenated at a lower hydrogenation reaction pressure. On the other hand, by at least 0.1 as ^1, it is possible to avoid the enlargement of the hydrogenation reactor.

<Hydrogen recovery process>

In the hydrogen recovery step, hydrogen is recovered from the gas component obtained in the separation step.

The method for recovering hydrogen is not particularly limited as long as hydrogen and other gases contained in the gas component obtained in the separation step can be separated. Examples include a pressure swing adsorption method (PSA method), a deep cold separation method, and a membrane separation method. Can be.

In general, the amount of hydrogen recovered in the hydrogen recovery step is larger than the amount required to hydrogenate the heavy distillate or light oil and kerosene distillate.

<Hydrogen supply process>

In the hydrogen supply process, the hydrogen obtained by the hydrogen recovery process is supplied to the hydrogenation reactor of a hydrogenation reaction process. About the hydrogen supply amount at that time, it adjusts according to the remaining distillation amount which isolate | separated naphthalenes in the naphthalene collection process supplied to a hydrogenation reaction process. In addition, if necessary, the hydrogen pressure is adjusted.

By providing a hydrogen supplying step as in the present embodiment, the remaining distillate can be hydrogenated in the naphthalene recovery step by using hydrogen by-produced in the decomposition reforming step, thereby improving the efficiency of the device. Can be.

<Recycling process>

In the recycling step, the hydrogenation reactant is mixed with the raw material oil and returned to the decomposition reforming reaction step. The hydrogenation reactant is obtained by reacting the remaining distillate after the separation of naphthalenes in the naphthalene recovery step in the hydrogenation reaction step.

By returning such a hydrogenation reactant to a decomposition reforming reaction process, monocyclic aromatic hydrocarbons and naphthalenes can also be obtained as a raw material of heavy distillate (except naphthalenes) as a by-product. Therefore, the by-product amount can be reduced, and the production amount of monocyclic aromatic hydrocarbons and naphthalenes can be increased. In addition, since saturated hydrocarbons are also produced by hydrogenation, hydrogen transfer reaction in the decomposition reforming reaction step can be promoted. From these, it is possible to improve the overall yield of monocyclic aromatic hydrocarbons with respect to the supply amount of raw material oil, and to improve the yield of naphthalenes.

In addition, when the remaining distillates separated from the naphthalenes in the naphthalene recovery step without being hydrotreated are returned to the decomposition reforming step as it is, since the reactivity of the polycyclic aromatic hydrocarbons is low, the yield improvement of the monocyclic aromatic hydrocarbons is hardly expected. . However, it is possible to aim at improving the yield of naphthalenes.

LPG Recovery Process

The LPG recovery process recovers LPG by-produced in the decomposition reforming reaction process from the liquid distillate separated in the separation process.

In this LPG recovery step, LPG is used to purify and recover liquid distillate having 3 and 4 carbon atoms, ie, propylene, propane, butene and butane. In the production method of the aromatic hydrocarbon of the present embodiment, unlike the products such as hydrocracking in a conventional petroleum refining process, since there are more olefins such as propylene and butene, hydrogenation is necessary if necessary. Alternatively, the olefins can be recovered by rectification.

As described above, in the method for producing an aromatic hydrocarbon of the present embodiment, a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms can be produced from a crude oil containing a polycyclic aromatic hydrocarbon in a relatively high yield, and further, naphthalene is included as another chemical product. Naphthalenes and olefins such as propylene, propane, butene and butane can also be produced.

Particularly, naphthalene is conventionally manufactured by a crystallization method in which coal tar effluent oil is cooled and crystallized, but the crystallization method requires a complicated process, and thus there are problems such as high manufacturing cost.

In contrast, in the method for producing the aromatic hydrocarbon of the present embodiment, in the step of producing a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms, a naphthalene having a relatively high purity is added only by adding a naphthalene recovery step or a naphthalene separation and recovery step as necessary. Can be obtained. Therefore, the production cost of naphthalene (or naphthalenes) is significantly lower than that of the conventional method by the crystallization method, except for the production of monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms, so that naphthalene (or naphthalenes) is inexpensively low. It becomes possible to provide.

`` Other embodiments ''

In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the main point of this invention.

For example, in the method shown in FIG. 1, a hydrogenation reaction step of hydrogenating a part of the liquid component separated in the separation step is provided between the separation step and the purification recovery step. The obtained hydrogenation reactant may be distilled, and the monocyclic aromatic hydrocarbon may be purified and recovered.

In addition, a part of the heavy distillate separated in the separation step may be supplied to the hydrogenation step without going through the naphthalene recovery step, and may be hydrogenated to return to the decomposition reforming step.

In addition, in these methods and the method shown in FIG. 1, the hydrogen obtained by the well-known hydrogen production method may be used instead of the by-produced in a decomposition reforming reaction process about hydrogen used in a hydrogenation reaction process, and also the other contact Hydrogen produced by the decomposition method can also be used.

<Examples>

Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to these Examples.

[Example of Preparation of Catalyst for Monocyclic Aromatic Hydrocarbon Production]

Preparation of Catalysts Comprising Ga and Phosphorus Supported Crystalline Aluminosilicates:

Sodium silicate solution (A) containing the (J Sodium Silicate No. 3, SiO ₂ 28 to 30% by mass, Na 9 to 10% by weight, the balance water, is prepared by Nippon Kagaku Kogyo (state)), and 1706.1g water and 2227.5g , Al ₂ (SO ₄ ) ₃ ㆍ 14-18H ₂ O (Reagent Express, manufactured by Wako Pure Chemical Industries, Ltd.) 64.2 g, Tetrapropylammonium bromide 369.2 g, H ₂ SO ₄ (97 mass%) 152.1 g, NaCl A solution (B) was prepared, comprising 326.6 g and 2975.7 g of water, respectively.

The solution (B) was then slowly added to the solution (A) while the solution (A) was stirred at room temperature.

The obtained mixture was stirred vigorously with a mixer for 15 minutes, and the gel was disintegrated to obtain an oily homogeneous fine state.

Subsequently, this mixture was put into a stainless autoclave, and crystallization operation was carried out under magnetic pressure under the condition of temperature 165 ° C, time 72 hours, and stirring speed 100 rpm. After the end of the crystallization operation, the product was filtered to recover the solid product, and washing and filtration were repeated five times using about 5 liters of deionized water. The solid obtained by filtration fractionation was dried at 120 degreeC, and also baked at 550 degreeC under air circulation for 3 hours.

The obtained fired material was confirmed to have an MFI structure as a result of X-ray diffraction analysis (model name: Rigaku RINT-2500V). Also, fluorescent X-ray analyzer (model _{name: Rigaku ZSX101e) SiO 2 / Al} 2 O 3 ratio (molar ratio) was 64.8 according to the. In addition, the aluminum element contained in the lattice skeleton calculated from this result was 1.32 mass%.

Subsequently, 30 mass% ammonium nitrate aqueous solution was added at the ratio of 5 mL per 1 g of obtained baking products, and it heated and stirred at 100 degreeC for 2 hours, and filtered and washed with water. After repeating this operation 4 times, it dried at 120 degreeC for 3 hours, and obtained ammonium crystalline aluminosilicate.

Thereafter, firing was carried out at 780 ° C. for 3 hours to obtain a protonic crystalline aluminosilicate.

Subsequently, 120 g of an aqueous gallium nitrate solution was impregnated with 120 g of gallium nitrate solution so as to carry 0.4 mass% (the value of total crystalline aluminosilicate total mass to 100 mass%) on 120 g of the obtained protic crystalline aluminosilicate and dried at 120 ° C. Thereafter, the mixture was calcined at 780 ° C for 3 hours under air flow to obtain gallium-supported crystalline aluminosilicate.

Subsequently, 30 g of an aqueous ammonium dihydrogen phosphate solution was impregnated with 30 g of the obtained gallium-supported crystalline aluminosilicate so as to carry 0.7 mass% of phosphorus (the value of the total mass of the crystalline aluminosilicate as 100 mass%) and dried at 120 ° C. Thereafter, the mixture was calcined at 780 ° C for 3 hours under air circulation to obtain a catalyst A containing crystalline aluminosilicate, gallium, and phosphorus.

In addition, when producing monocyclic aromatic hydrocarbon in the fluidized-bed reaction form, catalyst A is added to crystalline aluminosilicate, gallium, and phosphorus, and a silica binder (silica binder content is 60 mass% with respect to catalyst total mass). It contains more.

(Example 1)

LCO (10 vol% outlet temperature 224.5 ° C., 90 vol% outlet temperature 349.5 ° C.), which is a raw material oil, was added to catalyst A (gallium 0.4) in a fluidized bed reactor under conditions of a reaction temperature of 550 ° C., a reaction pressure of 0.1 MPaG, and a contact time of 30 seconds. A monocyclic aromatic hydrocarbon was produced by contacting and reacting with a MFI zeolite carrying mass% and 0.7 mass% of phosphorus, containing 60 mass% of a silica binder relative to the total mass of the catalyst).

The obtained reaction product oil was analyzed by FID gas chromatograph, and the amount of impurities between durene (boiling point of 196 ° C) and naphthalene (boiling point of 218 ° C) was 1.9% by mass with respect to naphthalene 100. The amount of impurities between naphthalene and 2-methylnaphthalene (boiling point of 241 ° C) is 0.6% by mass with respect to naphthalene 100 and 0.4% by mass with respect to methylnaphthalene 100, indicating that very few components have a boiling point close to naphthalene. Could.

Subsequently, the obtained reaction product oil was classified into a gas distillate, distillate containing monocyclic aromatic hydrocarbons (benzene, toluene, xylene), and heavy distillate with 9 or more carbon atoms (heavy distillate 1).

The heavy distillate 1 was further distilled in a distillation column and classified into distillate mainly containing naphthalene (boiling point 218 ° C.) and distillate other than naphthalene (heavy distillate 2).

The yield of the monocyclic aromatic hydrocarbon (benzene, toluene, crude xylene (xylene containing a small amount of ethylbenzene, etc.)) obtained by classification was 30 mass%, and the yield of naphthalene distillate was 7 mass%. In addition, naphthalene purity in the naphthalene distillate was 96 mass%.

(Example 2)

LCO (10 vol% outlet temperature 224.5 ° C., 90 vol% outlet temperature 349.5 ° C.), which is a raw material oil, was replaced with catalyst A (0.4 mass of gallium) in a fixed bed reactor under a reaction temperature of 550 ° C., a reaction pressure of 0.3 MPaG, and a contact time of 18 seconds. And MFI zeolite carrying 0.7% by mass of phosphorus) were reacted to produce monocyclic aromatic hydrocarbons.

As a result of analyzing the obtained reaction oil by FID gas chromatography, the amount of impurities between durene (boiling point of 196 ° C) and naphthalene (boiling point of 218 ° C) was 2.4% by mass with respect to naphthalene 100. It is noted that the amount of impurities between naphthalene and 2-methylnaphthalene (boiling point of 241 ° C) is 1.6% by mass with respect to naphthalene 100 and 0.9% by mass with respect to methylnaphthalene 100, indicating that there are very few components having a boiling point close to naphthalene. Could.

Subsequently, the obtained reaction oil was classified into a gas distillate, distillate containing monocyclic aromatic hydrocarbons (benzene, toluene, crude xylene), and heavy distillate having 9 or more carbon atoms in a rectification column.

The heavy distillate having 9 or more carbon atoms was further distilled in a distillation column and classified into distillate mainly containing naphthalene (boiling point 218 ° C) and distillate other than naphthalene.

The yield of the monocyclic aromatic hydrocarbon (benzene, toluene, crude xylene) obtained by classification was 37 mass%, and the yield of naphthalene distillate was 9 mass%. In addition, naphthalene purity in the naphthalene distillate was 95 mass%.

(Example 3)

Hydrogenation reaction other than naphthalene obtained in Example 1 (heavy distillate 2: Polycyclic aromatic hydrocarbon content is 95 mass% or more) using the commercially available nickel- molybdenum catalyst on the reaction temperature of 350 degreeC, and reaction pressure of 5 MPaG. Was performed. The obtained hydrogenated reactant contains 69 mass% of a hydrocarbon compound having one aromatic ring and 28 mass% of a compound (polycyclic aromatic hydrocarbon) having two or more aromatic rings, and the content of the polycyclic aromatic hydrocarbon is significantly reduced compared to before the hydrogenation reaction. It was.

Subsequently, the raw material oil which recycled the amount of hydrogenation reactant 0.4 mass times with respect to LCO to LCO shown in Table 1, the catalyst A (gallium) in a fluidized bed reactor on the conditions of reaction temperature of 550 degreeC, reaction pressure of 0.3 MPaG, and 30 second of contact time. A monocyclic aromatic hydrocarbon was produced by contacting and reacting with a MFI zeolite carrying 0.4 mass% and 0.7 mass% of phosphorus, containing 60 mass% of a silica binder relative to the total mass of the catalyst).

The yield of the obtained monocyclic aromatic hydrocarbon (benzene, toluene, crude xylene) was 36 mass%, and the yield improvement of the monocyclic aromatic hydrocarbon was seen compared with Example 1 which does not recycle the hydrogenation reaction product.

From the results of Examples 1-3, based on the manufacturing method of the aromatic hydrocarbon which concerns on this invention, the C6-C8 monocyclic aromatic hydrocarbon containing benzene, toluene, and crude xylene is obtained with high yield, and high purity (90 mass It was found that naphthalene of (% or more) can also be produced.

According to the method for producing an aromatic hydrocarbon of the present invention, using an oil containing a polycyclic aromatic hydrocarbon such as LCO, not only monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms, but also naphthalenes containing naphthalene can be produced together.

Claims (8)

Method for producing aromatic hydrocarbons,
A raw material oil having a 10 volume% outlet temperature of 140 ° C. or higher and a 90 volume% outlet temperature of 380 ° C. or lower is brought into contact with a catalyst for producing a monocyclic aromatic hydrocarbon containing crystalline aluminosilicate and reacted with a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms. And a cracking reforming reaction step of obtaining a product including a heavy distillate having 9 or more carbon atoms,
A separation step of separating the monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms and the heavy distillate having 9 or more carbon atoms from the product obtained in the decomposition reforming reaction step, respectively;
A purification recovery step of purifying and recovering a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms separated in the separation step;
A method for producing an aromatic hydrocarbon, characterized by having a naphthalene recovery step of separating and recovering naphthalenes containing at least naphthalene from a heavy distillate having 9 or more carbon atoms separated in the separation step. The method for producing an aromatic hydrocarbon according to claim 1, wherein the naphthalene recovery step is a step of separating and recovering methylnaphthalene and / or dimethylnaphthalene and naphthalene. The hydrogenation reaction process according to claim 1 or 2, wherein the remaining distillates obtained by separating naphthalenes in the naphthalene recovery step are hydrogenated to obtain a hydrogenation reactant;
And a recycling step of returning the hydrogenation reactant to the cracking reforming reaction step. The method for producing an aromatic hydrocarbon according to any one of claims 1 to 3, wherein the means for separating and recovering naphthalenes containing naphthalene in the naphthalene recovery step is a means using a distillation apparatus. The method for producing an aromatic hydrocarbon according to any one of claims 1 to 4, wherein the crystalline aluminosilicate is based on the mesoporous zeolite and / or the macroporous zeolite as a main component. The aromatic hydrocarbon according to any one of claims 1 to 5, wherein the reaction temperature when the raw material oil is reacted with the catalyst for producing a monocyclic aromatic hydrocarbon in the decomposition reforming reaction step is 400 ° C or more and 650 ° C or less. Method of preparation. The aromatic hydrocarbon according to any one of claims 1 to 6, wherein the reaction pressure when the raw material oil is reacted with the catalyst for producing a monocyclic aromatic hydrocarbon in the decomposition reforming reaction step is 0.1 MPaG or more and 1.5 MPaG or less. Method of preparation. The production of an aromatic hydrocarbon according to any one of claims 1 to 7, wherein a contact time for bringing the raw material oil into contact with the catalyst for producing a monocyclic aromatic hydrocarbon in the decomposition reforming reaction step is 1 second or more and 300 seconds or less. Way.

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