JPH0618798B2 - Method for producing ethylbenzene - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing ethylbenzene. More specifically, 1 selected from the group consisting of heteropolyacids and heteropolyacid salts (hereinafter collectively referred to as heteropolyacid compounds)
TECHNICAL FIELD The present invention relates to a method for producing ethylbenzene from an aromatic compound containing benzene and ethylene using a crystalline aluminosilicate obtained by contact with a modifier containing one or more compounds as a catalyst.

[Conventional technology]

Crystalline aluminosilicate is a porous material known as zeolite (hereinafter crystalline aluminosilicate is referred to as zeolite). Specifically, a natural zeolite such as mordenite, chabazite, and erionite, a silica component, an alkaline component, and a hydrothermally synthesized A-type, L-type, X-type, Y-type, etc. Zeolites can be mentioned. Furthermore, regarding the synthetic zeolite, zeolites having a skeleton structure different from that of natural zeolites such as ZSM-5 and ZSM-11 have been produced in recent years. Z crystallized especially in the presence of organic amines
SM-5 is obtained as a crystalline phase in a wide range of the silica / alumina molar ratio of the skeleton, and is attracting attention as a unique and useful zeolite.

It is also known that zeolite is porous, and its crystal skeleton forms an ordered cage structure, and when this is used as a catalyst, it exhibits shape selectivity of a molecular unit for a substance that participates in a reaction. That is, since zeolite is porous, the surface area inside the cage is about 100 times larger than the outer surface area, and the reaction fields of molecules that can pass inside the cage and those that cannot The resulting molecule reacts selectively. It is also known that zeolite exhibits much higher catalytic activity than conventional solid acids such as silica-alumina by subjecting it to various modification treatments such as proton exchange and cation exchange with rare earth elements.

As described above, zeolite has various excellent characteristics and is therefore extremely important industrially as a catalyst and an adsorbent, and technical development is still in progress in various industrial fields.

By the way, conventionally, in the case of using zeolite as a catalyst, many modification treatments of zeolite have been proposed in order to increase the selectivity and / or the conversion rate. Typical examples of the prior art relating to the modification treatment are shown in JP-A-54-
Japanese Patent Publication No. 27528 discloses a method of modifying with a compound containing magnesium, phosphorus and other elements.
Japanese Patent Publication No. 1-14118 discloses a method for producing a modified zeolite using a heteropolyacid compound. However, it has been difficult to selectively produce ethylbenzene by reacting an aromatic compound containing benzene, for example, a mixture of benzene and toluene with ethylene by the modified zeolites disclosed in these prior arts. It is considered that this is because the product is determined by the kind of the substituent of the alkylbenzene contained in the raw material, in other words, the reactivity of the alkylbenzene by the substituent.

On the other hand, the present inventors have conducted research on the relationship between the reactivity of an aromatic compound in the alkylation reaction of an aromatic compound containing benzene and the method for producing a catalyst. As a result, they have found that the crystalline aluminosilicate catalyst prepared by the modification treatment with the heteropolyacid compound under a specific treatment condition has a different reaction characteristic from the conventional catalyst, and arrived at the present invention.

[Structure of Invention]

In the first aspect of the present invention, a modifier containing one or more heteropolyacid compounds and a crystalline aluminosilicate are brought into contact with each other, followed by firing, if necessary, a binder is added, followed by molding and further firing. The present invention relates to a method for producing ethylbenzene, which comprises reacting an aromatic compound containing benzene with ethylene in the presence of the crystalline aluminosilicate catalyst obtained as described above.

Furthermore, the second aspect of the present invention is the presence of a crystalline aluminosilicate catalyst obtained by mixing a modifier containing one or more heteropolyacid compounds with a crystalline aluminosilicate, followed by molding and firing. The present invention relates to a method for producing ethylbenzene, which comprises reacting an aromatic compound containing benzene with ethylene.

The catalyst obtained by such a preparation method, when an aromatic compound containing benzene is used for alkylation with ethylene, produces a product having a completely different composition from the case of using a conventional catalyst, which is extremely high in the industrial structure of ethylbenzene. It is useful.

The catalyst used in the present invention will be described in detail below.

The zeolite used in the present invention may be any of natural zeolites such as mordenite and erionite and synthetic zeolites such as X-type, Y-type and pentasil-type zeolite as long as it has a cage structure through which benzene and ethylbenzene can pass. Further, depending on the purpose of use, proton type,
It is also possible to use an ammonium salt type, various metal salt types obtained by cation exchange, or those subjected to appropriate treatment such as dealumination. Further, in the present invention, a crystalline metallosilicate in which a part or all of aluminum or silicon constituting the zeolite is replaced with another element such as gallium, germanium or beryllium can also be used.

In the present invention, the heteropolyacid is a general term for an acid produced by condensing two or more kinds of inorganic oxygen acids, and is coordinated via the central heteroatom (group I to VIII element) of the heteropolyacid anion and oxygen. It can take various forms depending on the combination with a poly atom (usually Mo, W, Nb, V, etc.).

In the present invention, any heteropoly acid can be used without any trouble. Specifically, for example, 12-tungstophosphoric acid (H
₃ PW ₁₂ O ₄₀ ), 12-tungstosilicic acid (H ₄ SiW ₁₂
O ₄₀ ), 12-molybdophosphoric acid (H ₃ PMo ₁₂ O ₄₀ ), 1
2- tongue strike germanate acid _{(H 3 GeW 12 O 40)} , 12-
Molybdate de germane acid _{(H 3} GeMe ₁₂ O ₄₀₎ or the like can be mentioned.

Further, the heteropolyacid salt used in the present invention includes ammonium salts, alkali metal salts, alkaline earth metal salts and other metal salts of the above heteropolyacid.

These heteropolyacids or heteropolyacid salts are used by dissolving them in a solvent inert to zeolite and these heteropolyacid compounds. From the viewpoint of industrial practice, it is preferable to use a solvent having a high solubility as the solvent. Examples of the preferable suitable solvent include water, alcohol, ether, ketone and the like, and it is more preferable to use water from the viewpoint of industrial practice.

In the method for producing the catalyst of the present invention, as a binder to be added for facilitating the molding of the catalyst and imparting strength to the catalyst, a very general one such as alumina sol, silica sol, clay or the like is used. As the molding method, a general method such as compression molding or extrusion molding can be used. The method for producing a catalyst used in the present invention includes (1) contacting a crystalline aluminosilicate (zeolite) with a modifier containing one or more heteropolyacid compounds, followed by firing, and adding a binder if necessary, Then, a method of molding and baking, (2) a method of mixing the crystalline aluminosilicate (zeolite) with a modifier containing one or more heteropolyacid compounds and a binder, and then molding and baking It is either. Of course, depending on the purpose, the treatment for converting a part of the cation component of the zeolite into a proton, ammonium or a transition metal element may be carried out before, in the middle and after the catalyst production step (1) or (2). Further, the cation component may be a mixture of two or more of the above components.

In order to further clarify the present invention, a method for preparing a catalyst will be described by taking the method (1) as an example.

The heteropolyacid compound used for modifying the zeolite in the present invention is preferably used in a proportion of about 5 to 50% by weight based on the zeolite. Further, the hydrogen ion concentration of the denaturing agent during the denaturing treatment is preferably in the low pH range in order to prevent the heteropolyacid, which is strongly acidic, from deteriorating. The modification treatment can be carried out by various known means such as a dipping method and a spraying method. The temperature at that time may be a temperature at which the heteropolyacid compound does not decompose, and in the dipping method, it is preferably about 10 to 90 ° C. from the viewpoint of easy treatment. Of course, it is also possible to directly spray the zeolite at a temperature at which the heteropolyacid compound does not decompose. However, it suffices for the modification treatment to substantially bring the zeolite and the modifier into contact, and the immersion method is industrially preferable. Contact time with denaturant is about 30 minutes to 5
It is preferably about 0 hours and usually about 3 to 10 hours.

The zeolite modified with the heteropolyacid compound is then subjected to calcination. The calcination is performed in the presence of oxygen or air, and the temperature may be within the range where the zeolite does not deteriorate. For example, the firing temperature is about 400 to 650 ° C., and the firing time is about 1 to 20 hours. The modification with the heteropolyacid compound and the firing may be repeated.

The calcined zeolite is subjected to molding. As a molding means, a generally known method such as extrusion molding is adopted as described above. Further, as a binder added for improving moldability and imparting strength, a general binder such as alumina sol can be used. When using a binder, the amount added is about 5 relative to zeolite.
It is preferably in the range of 50% by weight. The zeolite treated with the heteropolyacid compound in this manner is molded into various shapes such as powder and pellets according to the purpose of use, and is subjected to firing again. The firing in this case is also carried out under exactly the same conditions as the firing described above. Above (1)
Although the preparation method has been described by taking the above method as an example, the method and conditions of the method (2) are the same, although the order is different.

The catalyst prepared by the above method is used for the reaction of producing ethylbenzene from an aromatic compound containing benzene and ethylene.

The raw material used in the present invention desirably contains benzene in an amount of 5% by weight or more, preferably 15% by weight or more. The kind of aromatic compound other than benzene contained in the raw material is not particularly limited, but it is a compound having 7 to 9 carbon atoms, specifically, toluene, xylene and the like. Further, a non-aromatic compound may be contained as long as it does not participate in the reaction. The supply rate of the aromatic compound containing benzene as a raw material (weight unit hourly space velocity (WHSV)) can be changed depending on its composition and reaction operating conditions, but is generally in the range of 0.1 to 200 hr ^-1 , preferably 0.5 to It is in the range of 50 hr ^-1 . The weight unit hourly space velocity (WHSV) is given by the following equation.

Another raw material used in the present invention, ethylene, is used in a benzene / ethylene molar ratio of 0.1 to 15, preferably 0.5 to 5.

These raw materials may be supplied to the reaction section as they are, or may be diluted with a gas such as nitrogen, carbon dioxide, methane or the like and supplied.
The ethylene / hydrogen molar ratio of hydrogen supplied for the purpose of maintaining the activity of the catalyst is in the range of 0.1 to 20, preferably 0.1.
The range is from -10.

The reaction temperature in the present invention needs to be at least 200 ° C. or higher in order to keep the reaction system in the gas phase.
Since the crystal structure of the catalyst may change at a temperature of 0 ° C. or higher, it is preferably in the range of 300 to 600 ° C. Further, the reaction pressure may be any of reduced pressure, normal pressure and increased pressure, but industrially a range of normal pressure to 30 kg / cm ² G is suitable. The reaction system is preferably a flow reaction system using a fixed bed or a fluidized bed.

Hereinafter, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to these.

Example 1 50 g of a proton-type zeolite having a silica / alumina ratio of 50 (proton exchange rate 60%) of pentasil type was added to 200 g of a 10 wt% aqueous solution of 12-tungstophosphoric acid, and the mixture was immersed for 5 hours with gentle stirring. From the analysis of the concentration of 12-tungstophosphoric acid in the aqueous solution before and after the immersion, the amount of 12-tungstophosphoric acid supported on the zeolite was 14% by weight. Next, after separating the solution from the zeolite, 110 ℃
Was dried for 2 hours and calcined at 610 ° C. for 5 hours in the presence of air. The modified zeolite obtained is 2
The mixture was thoroughly mixed with 125 g of a 0 wt% alumina sol aqueous solution and extrusion-molded. The molding size at this time is 3 mm in diameter and 10 in length.
It was mm. Then, after drying at 110 ° C for 2 hours, 52
A catalyst A was obtained by calcining at 0 ° C. for 16 hours.

Example 2 A catalyst B was obtained by the same catalyst preparation operation as in Example 1 except that 12-tungstophosphoric acid was used instead of 12-tungstophosphoric acid.

The amount of 12-tungstosilicic acid supported on the zeolite at this time was 15% by weight.

Example 3 A catalyst C was obtained by the same catalyst preparation operation as in Example 1 except that sodium 12-tungstophosphate was used instead of 12-tungstophosphoric acid. At this time, the amount of sodium 12-tungstophosphate supported on the zeolite was 13% by weight.

Example 4 50 g of pentasil-type sodium / zeolite having a silica / alumina ratio of 50 is added to 200 g of a 10% by weight aqueous solution of 12-tungstophosphoric acid, and the mixture is stirred gently.
Soak for hours. From the analysis of 12-tungstophosphoric acid in the aqueous solution before and after the immersion, the amount of 12-tungstophosphoric acid supported on the zeolite was 15% by weight. The zeolite was then filtered off, dried at 110 ° C. for 2 hours and calcined at 610 ° C. for 5 hours in the presence of air. The modified zeolite thus obtained is then treated with 0.05N ammonium chloride aqueous solution 100
Cation exchange was carried out for 5 hours at 95 ° C. with gentle stirring. The cation exchange rate at this time is 55.
%Met.

Zeolite is separated by filtration and then 20 wt% alumina sol aqueous solution 12
5 g was thoroughly mixed and extruded. Thereafter, it was dried at 110 ° C. for 2 hours and then calcined at 520 ° C. for 16 hours to obtain catalyst D.

Example 5 Pentasil-type silica / alumina ratio 50 proton type zeolite (proton exchange rate 60%) 50 g, a 20 wt% aqueous solution of 12-tungstophosphoric acid 50 g and a 20 wt% alumina sol aqueous solution 125 g were thoroughly mixed and heated. After adjusting the water content with, the mixture was extruded. The molding size at this time was 3 mm in diameter and 10 mm in length. Then at 110 ℃ 2
After being dried for an hour, it was calcined at 610 ° C. for 16 hours to obtain a catalyst E.

Example 6 50 g of a sodium type zeolite having a silica / alumina ratio of 50 of pentasil type, 100 g of a 20 wt% aqueous solution of 12-tungstosilicic acid and 125 g of a 20 wt% alumina sol aqueous solution were sufficiently mixed, and the moisture was adjusted by heating, followed by extrusion molding. . Thereafter, it was dried at 110 ° C. for 2 hours and then baked at 610 ° C. for 16 hours. The obtained modified zeolite is then treated with a 0.05N ammonium chloride aqueous solution of 1000 m.
Cation exchange was carried out for 5 hours at 95 ° C. with gentle stirring. Cation exchange rate at this time is 56%
Met.

Zeolite was filtered off and dried at 110 ° C for 2 hours.
The catalyst F was obtained by calcining at 0 ° C. for 16 hours.

Comparative Example 1 50 g of pentasil-type silica / alumina ratio 50 proton type zeolite (proton exchange rate 60%) and 20% by weight
125 g of an alumina sol aqueous solution was sufficiently mixed and extruded.

At this time, the molding size was 3 mm in diameter and 10 mm in length.
It is then dried at 110 ° C. for 2 hours and 520 in the presence of air.
It was baked at 16 ° C. for 16 hours. The molded and fired zeolite was treated with 12-tungstophosphoric acid 10% by weight aqueous solution 200
It was added to g and immersed for 5 hours with gentle stirring. From the analysis of the 12-tungstophosphoric acid concentration in the aqueous solution before and after the immersion, the amount of 12-tungstophosphoric acid supported was 13% by weight. Next, the zeolite was filtered off, dried at 110 ° C. for 2 hours, and calcined at 610 ° C. for 5 hours in the presence of air to obtain comparative catalyst 1.

Comparative Example 2 Comparative catalyst 2 was obtained by the same catalyst preparation operation as in Comparative example 1 except that 12-tungstosilic acid was used instead of 12-tungstophosphoric acid.

Comparative Example 3 Pentasil-type silica / alumina ratio 50 proton-type zeolite (proton exchange rate 60%) 50 g and 20% by weight
125 g of an alumina sol aqueous solution was thoroughly mixed and extruded. At this time, the molding size was 3 mm in diameter and 10 mm in length. It is then dried at 110 ° C. for 2 hours and 5 times in the presence of air.
Comparative catalyst 3 was obtained by calcining at 20 ° C. for 16 hours and then at 610 ° C. for 5 hours.

Example 7 Catalysts A to F and comparative catalysts 1 to 3 each having a particle size adjusted to 20 to 42 mesh were used as a catalyst, and a mixed oil of benzene and toluene (50 mol% of benzene) was ethylated with ethylene. The reaction conditions are reaction pressure 10.0 kg / cm
² G, reaction temperature 400 ° C., catalyst amount 5.6 g, benzene
Toluene mixed oil supply rate 56g / hr, hydrogen flow rate 2.4N
/ Hr, the flow rate of ethylene was 2.4 N / hr, and the reaction results shown in Table 1 were obtained. From the results shown in Table 1, the method for producing ethylbenzene using the catalyst according to the present invention has an extremely high production ratio of ethylbenzene as compared with the method using the catalyst prepared by the method shown in Comparative Example, and is clearly advantageous for producing ethylbenzene. there were.

[Advantages of the Invention] As described above, according to the method of the present invention, ethylbenzene can be selectively produced by reacting a raw material containing an aromatic compound other than benzene with ethylene. That is, a zeolite catalyst modified by a specific operating procedure with a modifier containing a heteropolyacid compound shown in the present invention has reaction characteristics different from those of conventional catalysts, and as a result, contains an aromatic compound other than benzene. It is possible to selectively produce ethylbenzene even if an inexpensive raw material is used.

Claims (2)

[Claims] 1. The presence of a crystalline aluminosilicate catalyst obtained by bringing a modifier containing one or more heteropolyacid compounds into contact with a crystalline aluminosilicate, followed by calcination, then molding, and further calcination. A method for producing ethylbenzene, which comprises reacting an aromatic compound containing benzene with ethylene below. 2. Benzene is added in the presence of a crystalline aluminosilicate catalyst obtained by mixing a modifier containing one or more heteropolyacid compounds with a crystalline aluminosilicate, followed by molding and firing. A method for producing ethylbenzene, which comprises reacting an aromatic compound containing ethylene with ethylene.