JPH032128A - Production of monocyclic aromatic-containing hydrocarbon - Google Patents

Abstract

PURPOSE:To efficiently obtain the subject compound useful as a raw material for substrate for high-octane gasolines or pertrochemicals, such as benzene or toluene, in high yield by reacting a polycyclic aromatic-containing hydrocarbon using a specific catalyst. CONSTITUTION:A polycyclic aromatic-containing hydrocarbon is reacted in the presence or absence of hydrogen gas in the presence of a catalyst containing Ga or Zn and zeolite having 1-12 value of control index [CI=log10 (residual content of n-hexane)/log10 (residual content of 3-methylpentane)] or in the coexistence of an inert gas, such as nitrogen gas, at 350-700 deg.C, preferably 450-600 deg.C to afford the objective compound. Especially preferred reaction conditions are a temperature within the range of 450-600 deg.C and the molar ratio of the H fed to the reaction system to the polycyclic aromatic-containing hydrocarbon within the range of >=0 to <=1. Furthermore, the aforementioned catalyst is prepared by a method for ion exchange, etc., using a Ca- or Zn-containing compound together with the zeolite.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a monocyclic aromatic-containing hydrocarbon, and more specifically, the present invention relates to a method for producing a monocyclic aromatic-containing hydrocarbon, and more specifically, a process for producing a high-octane gasoline base material, benzene, from a polycyclic aromatic-containing hydrocarbon. The present invention relates to a method for advantageously producing monocyclic aromatic hydrocarbons useful as petrochemical raw materials such as toluene and xylene.

[Prior Art] Many studies have been conducted on catalytic cracking and hydrocracking of heavy hydrocarbon fractions such as light oil.

For example, JP-A-59-49289 describes catalytic cracking of heavy hydrocarbon fractions using a catalyst prepared by mixing an amorphous cracking catalyst with zeolite having a CI value of 1 to 12. However, in this case, the zeolite component is small compared to the amorphous decomposition catalyst, and a catalyst containing Ga or Zn is not used, so the yield of monocyclic aromatic hydrocarbons is not sufficient.

Further, Japanese Patent Publication No. 59-11635 and US Pat. No. 3,893,906 disclose the use of ZSM-5 type zeolite for dewaxing treatment of light oil. However, in these cases, the purpose is not to produce monocyclic aromatic hydrocarbons from polycyclic aromatic-containing hydrocarbons, and the reaction conditions of the examples are also such that the reaction temperature is 300 to 400°C.
1 Molar ratio of hydrogen and hydrocarbon to be supplied (H2/H, C,
) is in the range of 1 to 20, which is inappropriate for producing monocyclic aromatic hydrocarbons. Furthermore, there is no description of raw materials such as LCO and other fractions with a large polycyclic aromatic content.

On the other hand, JP-A-56-157488 discloses that polycyclic aromatic-containing hydrogen is brought into contact with a polycyclic aromatic-containing raw material and hydrogen with a catalyst containing a zeolite having a CI value of 1 to 12 and a nickel-tungsten hydrogenation component. A hydrocracking method containing 111 is disclosed. However, in this method, the molar ratio of hydrogen and hydrocarbon to be supplied (Hz/H, C,) is 2.
~80, a high hydrogen partial pressure of 7.9 to 139 kg/cfll is required, a large amount of saturated hydrocarbons are produced, and a sufficient yield of monocyclic aromatic hydrocarbons cannot be obtained.
There are problems such as high hydrogen consumption.

In addition, JP-A-61-148295 discloses that in the first stage, the two-ring aromatic raw material is partially saturated using a nickel-containing catalyst, and in the second stage, the monocyclic aromatic material is carbonized by zeolite fluidized catalytic cracking. A method of producing hydrogen-containing gasoline is disclosed. However, in this method,
The yield of monocyclic aromatic hydrocarbons is low, and it is a two-stage reaction, which has problems such as high energy costs.

That is, as seen in the example above, the conventional FCC catalyst (
Catalytic cracking using X- or Y-type zeolites, silica-alumina, etc.) is not aimed at producing monocyclic aromatic-containing hydrocarbons from polycyclic aromatic-containing hydrocarbons. Furthermore, there are many methods of mixing ZSM-5 type zeolite with this FCC catalyst, but these methods are also not aimed at producing monocyclic aromatic-containing hydrocarbons from polycyclic aromatic-containing hydrocarbons, as described above. On the other hand, there are several other examples of hydrocracking to convert polycyclic aromatic-containing hydrocarbons into monocyclic aromatic-containing hydrocarbons, but all of them are conducted under relatively high hydrogen partial pressures, as in the above survey. This reaction produces many saturated hydrocarbons and has problems such as a low yield of monocyclic aromatic hydrocarbons, high hydrogen consumption, and high energy costs.

[Problem to be solved by the invention]

The present invention has been made in view of the above circumstances.

An object of the present invention is to provide a practically advantageous method for producing monocyclic aromatic hydrocarbons that can efficiently obtain monocyclic aromatic hydrocarbons from polycyclic aromatic hydrocarbons in high yield. There is a particular thing.

[Means to solve the problem]

As a result of intensive research to solve the above-mentioned problems, the present inventors have discovered that monocyclic aromatic hydrocarbons can be produced in high yield by reacting polycyclic aromatic-containing hydrocarbons using a specific catalyst.
The inventors have also discovered that monocyclic aromatic-containing hydrocarbons can be obtained efficiently and advantageously, and have completed the present invention based on this knowledge.

That is, the present invention converts polycyclic aromatic-containing hydrocarbons into Ga
Alternatively, it is a method for producing a monocyclic aromatic-containing hydrocarbon, characterized in that Zn is brought into contact with a catalyst containing a zeolite having a CI value of 1 to 12 and reacted.

In the present invention, the polycyclic aromatic is an aromatic hydrocarbon having two or more rings having at least one aromatic nucleus, which may or may not have a substituent. Either is fine. Examples of the polycyclic aromatic group include substituted naphthalenes having one or more acyclic hydrocarbon groups as substituents such as naphthalene, alkyl or alkenylnaphthalene, phenyl groups such as biphenyls, diphenylalkanes, and diphenylalkenes. Aromatic two-ring hydrocarbons having two substituted phenyl groups, benzenes having a hydrocarbon group containing one non-aromatic cyclic hydrocarbon group such as a cycloalkyl group and a cycloalkenyl group as a substituent, or indene. Various two-ring aromatic hydrocarbons, such as bicyclic aromatic hydrocarbons containing one benzene nucleus or substituted benzene nucleus and one non-aromatic hydrocarbon ring, such as dihydronaphthalenes, tetrahydronaphthalenes, etc. hydrogen, anthracene, substituted anthracenes having one or more acyclic hydrocarbon groups as substituents;
Phenanthrene, substituted phenanthrenes having one or more acyclic hydrocarbon groups as substituents, tricyclic aromatic hydrocarbons having one or two benzene rings or substituted benzene rings, or one naphthalene ring Alternatively, various 3-ring aromatic hydrocarbons such as 3-ring aromatic hydrocarbons having a substituted naphthalene ring can be mentioned. Among these, in the method of the present invention, naphthalene, the above-mentioned substituted naphthalenes, or naphthalene-based polycyclic aromatic hydrocarbons containing at least one thereof, which were conventionally considered difficult to decompose into monocyclic aromatic hydrocarbons, Anthracene, the above-mentioned substituted anthracene, or a small amount (both 1
Monocyclic aromatic-containing hydrocarbons can be efficiently obtained from anthracene-based polycyclic aromatic hydrocarbons containing seeds, phenanthrene, substituted phenanthrene, or phenanthrene-based polycyclic aromatic hydrocarbons containing at least one of these.

In the present invention, the polycyclic aromatic hydrocarbon used as a reaction raw material may be a single compound of the polycyclic aromatic hydrocarbon or a mixture of two or more thereof; It may be a mixture of one or more hydrocarbons and other hydrocarbons.

Among these, specific examples of polycyclic aromatic-containing hydrocarbons preferable as reaction raw materials include, for example, LCOlHCOl
Examples include FCC circulating oil such as CLO, liquefied coal oil, coker gasoline, heavy oil hydrocracked oil, etc., and various mixtures made by mixing each of these exemplified fractions with other hydrocarbons. can. These fractions and mixtures can also be used in combination, such as by mixing two types of them, if desired.

Note that the polycyclic aromatic-containing hydrocarbon may contain heteroatom-containing hydrocarbons containing sulfur components, oxygen components, nitrogen components, etc., within a range that does not impede the purpose of the present invention. good.

In the method of the present invention, the polycyclic aromatic-containing hydrocarbon or mixed raw material containing the same is added to the catalyst (i.e., G
a or Zn and a catalyst containing a zeolite having a CI value of 1 to 12) to produce a monocyclic aromatic-containing hydrocarbon.

By the way, the CI value is an index that indicates whether the pores of zeolite have the necessary characteristics to control the entry of molecules with a cross section larger than n-paraffin, that is, a control index. The method of determining the value is fully described in US Pat. No. 4,016,218. The definition and measurement method of the CI value related to the present invention are as follows:
According to that US Pat. No. 4,016,218. Specifically, n-hexane and 3-
A mixture of equal weights with methylpentane, 90-51
The amount remaining unchanged of each of the two hydrocarbons when passed over zeolite at 0° C. and 5 atmospheric pressures is determined.

The value of this control index is close to the ratio of the cranking rate constants of the two hydrocarbons.

In the method of the present invention, various types of zeolite having a CI value of 1 to 12 can be used as the catalyst or its component, and specific examples thereof include 23M5, ZSM, etc. -8,ZSM-11
ZSM-5 type zeolite, ZSM-23, ZSM-
35, clinoptilolite, TMA offretite, etc. Among these, ZSM-5, Z
ZSM-5 type zeolites such as SM-8 and ZSM-11 are preferred.

The catalyst used in the production of the monocyclic aromatic-containing hydrocarbon of the present invention contains at least one zeolite having the CI value of 1 to 12, but this catalyst also contains a Ga or Zn component or a Ga or Zn component. and Zn.

This Ga or Zn component is added in various forms such as metals, carbonates, sulfates, nitrates, oxides, sulfides, and chlorides, and is preferably added in the form of oxides and sulfides by processing such as calcination. Used as the form of a thing.

In constituting the catalyst or its component used in the method of the present invention, the Ga or Zn component can be used in various combinations with the zeolite. This Ga or Zn is, for example, a component of the zeolite (e.g., an ion-exchangeable cation, a substituted atom in the framework, or a treatment such as during catalyst preparation, pretreatment, reaction, or regeneration). Alternatively, the zeolite containing Ga and/or Zn components, the zeolite not containing these components, or a mixture thereof may be subjected to ion exchange, for example. The zeolite may be contained in a supported form by a zeolite method, an impregnation method, etc. (or it may be contained in a form of a physical mixture with the zeolite), and may be contained in any form.

In the method of the present invention, as the zeolite used as the catalyst or its component, galloaluminosilicate and its modified zeolite can be particularly preferably used among the various zeolites described above. In this galoaluminosilicate and its modified zeolite, the state of Ga may be an ionic state, a lattice substituted atom state, an oxide state, or a mixed state thereof. After synthesis, galloaluminosilicate is not necessarily in a four-coordinated state in which all Ga is incorporated into its lattice, but it is thought that six-coordinated gallium oxide exists. In addition, by subjecting galloaluminosilicate to a modification treatment such as high-temperature treatment or steam treatment, Ga can be removed from the lattice and become six-coordinated Ga, which can be used as a zeolite and zeolite that provides catalytic properties such as more favorable activity. can do. Further, the high temperature treatment can be performed in any atmosphere such as air, inert gas, or hydrogen.

The shape of the catalyst used in the method of the present invention is not particularly limited, and it can be molded into various shapes as desired. During this molding, a binder can be used as appropriate. Any material can be used as the material as long as it does not interfere with the purpose of the present invention, and specific examples include alumina, silica, silica/alumina, and various clay minerals. be able to.

Further, the catalyst can also contain other additive components within a range that does not interfere with the purpose of the present invention.

The method for preparing the catalyst used in the method of the present invention is not particularly limited. For example, the catalyst may be prepared by using a compound containing Ga or Zn in the various zeolites, such as an ion exchange method, an impregnation method, or a physical mixing method. Alternatively, Ga or Z may be added to the gel when synthesizing zeolite.
A method may also be used in which n compounds are included. Further, this Ga or Zn may be added before or after bonding with the binder. After the binder is impregnated with or kneaded with Ga or Zn compound, this may be mixed with zeolite.

Catalysts in various shapes prepared in this way can be used as catalysts in the method of the present invention as they are, but they are usually subjected to air calcination as appropriate, and further subjected to various activation treatments and modification treatments as desired. It is preferable to perform pretreatment such as treatment before use. Examples of this modification treatment include the above-mentioned steam treatment, high temperature treatment, and other dealumination treatments, and activation treatment includes, for example, dehydration by heat treatment in an inert gas or under vacuum exhaust. process,
Alternatively, there is a reduction treatment using a reducing gas such as hydrogen gas. Through these activation treatments and modification treatments, the catalyst activity can be further improved, and the catalyst properties can also be adjusted as appropriate depending on the properties of the polycyclic aromatic-containing hydrocarbon used.

In the method of the present invention, the polycyclic aromatic-containing hydrocarbon or the raw material mixture containing the same is combined with the Ga or Zn and C
It is supplied to a reaction system to be brought into contact with a catalyst containing a zeolite having an I value of 1 to 12, and reacted to produce a desired monocyclic aromatic-containing hydrocarbon.

In the method of the present invention, the reaction may be performed in the presence or absence of hydrogen gas. That is, the feedstock supplied to the reaction system may or may not contain hydrogen gas. Hydrogen gas (H2) in this feedstock and total hydrocarbons () in the polycyclic aromatic-containing hydrocarbons1. c, ) ratio, that is, H2/H,C.

(molar ratio) can be set to any ratio including zero, but if this ratio is too large, undesirable hydrogenolysis will easily occur and the production of lower paraffins will increase.
Since the yield of monocyclic aromatic hydrocarbons may decrease,
Usually, it is preferable that 0≦H2/H,C,≦1 (molar ratio).

Further, the reaction can be carried out in the presence of other gas components such as inert gas such as nitrogen gas, argon, and helium, or steam, within a range that does not interfere with the purpose of the present invention.

In the method of the present invention, the reaction is usually carried out at 350 to 7
It is suitable to conduct the reaction at a temperature of 00°C, preferably 450 to 600°C. If this reaction temperature is too high, undesirable decomposition reactions will occur, leading to a decrease in the yield of monocyclic aromatic hydrocarbons and catalyst deterioration.
If the reaction rate is too low, a sufficient reaction rate may not be obtained.

In the method of the present invention, the reaction is carried out at a reaction temperature of 450
~600°C, and the molar ratio of hydrogen and polycyclic aromatic-containing hydrocarbon (hydrogen/polycyclic aromatic-containing hydrocarbon) supplied to the reaction system is within the range of 0 or more and 1 or less [i.e.
0≦H2/11. c, ≦1 (molar ratio)].

As mentioned above, in the method of the present invention, the desired reaction can be effectively carried out without supplying (or adding) hydrogen gas to the reaction system, and when hydrogen gas is supplied (or added), Even in that supply! (or amount added)
Compared to conventional hydrocracking reactions, a small amount of hydrogen gas is sufficient, and the consumption of the supplied (or added) hydrogen gas can be significantly reduced.

The reaction pressure is not particularly limited, but is usually 0 to 2°Okg/
cdG, preferably within the range of 0 to 10 kg/crlrG.

Feed rate of feedstock (weight hourly space velocity or WH3V)
The appropriate range is usually 0.1 to 100 h r-', preferably 1 to 10 h+''.

In the method of the present invention, the reaction method is not particularly limited and can be carried out using various reaction methods, but usually it is suitably carried out using a fixed bed, moving bed or fluidized bed. I can do it.

This reaction may be carried out by either a one-stage reaction or a multi-stage reaction of two or more stages, but according to the method of the present invention, usually,
A one-stage reaction is sufficient.

Therefore, the method of the present invention can significantly reduce energy costs.

In the manner described above, the polycyclic aromatic hydrocarbon can be converted into monocyclic aromatic hydrocarbons such as benzene, toluene, and xylene with a high yield.

That is, according to the present invention, a product containing a highly utilized monocyclic aromatic hydrocarbon such as benzene, toluene, xylene, etc. from the various polycyclic aromatic hydrocarbons in a high concentration, that is, a monocyclic aromatic-containing hydrocarbon. Hydrocarbons can be obtained efficiently.

The monocyclic aromatic-containing hydrocarbon containing a high concentration of monocyclic aromatic hydrocarbons obtained in this way is obtained after appropriate separation and removal of low boiling point fractions such as lower hydrocarbons, gas components, unreacted raw materials, etc. Either as a mixed solution or by adjusting the composition as appropriate,
For example, it can be suitably used as a base material for high octane gasoline, or benzene, toluene, etc.
Kisile.

It is also possible to appropriately separate monocyclic aromatic hydrocarbons such as monocyclic aromatic hydrocarbons and use them suitably as petrochemical raw materials, high-quality solvents, and the like.

In addition, hydrogen gas, light hydrocarbons (for example, paraffins and olefins having about 1 to 5 carbon atoms, etc.) are usually obtained as by-products by the above reaction, but these can be recycled to the reaction system as desired. It can also be used effectively. Furthermore, if unreacted raw materials are generated, they can also be recycled and used effectively if desired.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Comparative Example 1 7.6 g of aluminum sulfate made in a soot standing dish, 26.4 g of tetrapropylammonium bromide, 17.6 g of sulfuric acid (97%),
A solution consisting of water 250 relatives is (a) liquid, water glass (SiO
z 28.4%, Naz 09.5%) 214g, water 21
Solution (b) consisting of 2d, 80g of sodium chloride, 12g of water
A solution consisting of 2d (C1 solution).Solutions (a), (b
) are simultaneously gradually added dropwise to solution (C) and mixed.

After adjusting the pH of the reaction mixture to pH 9.5 with sulfuric acid, it was placed in an autoclave at 170°C under autostatic pressure.
Hold with stirring at 300 rpm for an hour. After cooling, filter and thoroughly wash with excess pure water. After that, 12
An aluminosilicate zeolite having a ZSM-5 structure was synthesized by drying at 0°C for a day and a night. This is then fired at 540"C for 3 hours in an air stream. After that,
Ion exchange with IN NH, NO3 at 80℃ for 2 hours,
Filtration, washing with water, drying at 120°C, baking at 540°C in an air stream, ion exchange with IN N) IzNO, filtration, washing with water,
After repeated drying at 120°C, it was fired at 550°C for 3 hours in an air stream. The elemental composition of this aluminosilicate is SiO□:Aha, molar ratio = 80 = 1, and its CI
The value was 8.0.

Example 1 A solution consisting of 7.6 g of aluminum sulfate, 6.9 g of gallium nitrate, 26.4 g of tetrapropylammonium bromide, 15.0 g of sulfuric acid (97%), and 250 ml of water (
a) ZSM-
A galloaluminosilicate zeolite with 5 structures was synthesized. Then, this is baked at 540° C. for 3 hours in an air stream. After that, in NH, NO3 at 80℃ for 2 hours.
After repeated ion exchange, filtration, water washing, drying at 120°C, calcination at 540°C in an air stream, ion exchange with IN N1 (, NO, filtration, water washing, and I 20 "C drying),
Calcined at 720'C for 3 hours in a stream of air. The elemental composition of this galloaluminosilicate is Sin□:8120:
l:Gaz03 molar ratio=SO:t:0.7, and its CI value was 8.1.

Example 2 Smallpox ■± Using the catalyst prepared in Example 1', the reaction temperature was 530°C.
, WH3V=2 hr-', and the reaction was carried out in a fixed bed reactor under the conditions of no hydrogen addition. LCO was used as a raw material for the reaction. The composition of LCO is paraffin or naphthene 22w
t%, monocyclic aromatic 32wt%, two-ring aromatic 38wt%,
The content of 3-ring aromatics was 8 wt%.

The reaction results are shown in Table 1.

Comparative Example 2 A reaction was carried out in the same manner as in Example 2, except that the catalyst of Comparative Example 1 was used.

The reaction results are shown in Table 1.

Table 1 Reaction Results (Effects of the Invention) According to the present invention, monocyclic aromatic hydrocarbons such as benzene, toluene, and xylene can be produced from polycyclic aromatic-containing hydrocarbons in high yields because a specific catalyst is used. Furthermore, the amount of hydrogen gas used and consumption is small.
Since the step reaction can be carried out effectively, it is possible to provide a method for producing monocyclic aromatic hydrocarbons which is extremely advantageous in practice and has significantly improved efficiency such as a significant reduction in energy costs.

Claims (1)

[Scope of Claims] 1. A monocyclic aromatic-containing hydrocarbon characterized by contacting and reacting a polycyclic aromatic-containing hydrocarbon with a catalyst containing Ga or Zn and a zeolite having a CI value of 1 to 12. Method for producing hydrocarbons. 2. The method for producing a monocyclic aromatic hydrocarbon according to claim 1, wherein the zeolite is a ZSM-5 type zeolite. 3. The method for producing a monocyclic aromatic-containing hydrocarbon according to claim 1 or 2, wherein the zeolite is a galloaluminosilicate zeolite or a modified zeolite thereof. 4. The reaction is carried out at a reaction temperature of 450 to 600°C, and at a molar ratio of hydrogen to polycyclic aromatic-containing hydrocarbon (hydrogen/polycyclic aromatic-containing hydrocarbon) of 0 or more. The method for producing a monocyclic aromatic-containing hydrocarbon according to claim 1, 2 or 3, wherein the method is carried out within a range of 1 or less. 5. Claim 1, wherein the polycyclic aromatic-containing hydrocarbon contains one or more selected from FCC circulating oil, coal liquefied oil, coker gasoline, and heavy oil hydrocracked oil.
, 2, 3, or 4. The method for producing a monocyclic aromatic-containing hydrocarbon.