JPS61221136A - Production of p-alkylbenzene - Google Patents

Abstract

PURPOSE:To obtain selectively the titled substance, by reacting a monoalkylbenzene with an alcohol in the presence of a catalyst of a modified crystalline aluminosilicate obtained by adjusting a crystalline aluminosilicate to a proton exchange ratio in a specific range and treating it with a modifier. CONSTITUTION:A monoalkylbenzene is reacted with an alcohol in the presence of a catalyst of a modified crystalline aluminosilicate at 150-400 deg.C to give selectively the titled p-alkylbenzene. The catalyst is prepared by adjusting crystalline aluminosilicate to 25-80% proton exchange range, bringing into contact with a modifier containing a heteropolyacid (e.g., 12-tungstophosphoric acid H3PW12O40) or heteropolyacid salt (e.g., Al salt) by immersion method, spray method, etc., at 10-30 deg.C for 5-20hr, filtering, drying and calcining in the presence of oxygen at 400-650 deg.C for 1-20hr. EFFECT:The aimed substance is obtained by a catalyst capable of keeping high activity for a long period in high conversion ratio in high para selectivity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing dialkylbenzene using a novel modified crystalline aluminosilicate as a catalyst. More specifically, the present invention relates to a method for selectively producing para-dialkylbenzene using a novel modified crystalline aluminosilicate as a catalyst.

[Conventional technology]

Various alkylbenzenes, such as ethyltoluene and diethylbenzene, are used as precursors to make the corresponding vinyl aromatic monomers, and the monomers obtained from these, namely vinyltoluene, divinylbenzene, etc., are used to prepare various polymeric compounds. It is an important substance as a manufacturing raw material. Also,
Paracymene is a raw material for balacresol, which is used as an intermediate for antioxidants, and paradiisopropylbenzene is useful as a raw material for producing hydroquinone.

Conventionally, these dialkylbenzenes have been produced by a method in which a monoalkylbenzene and an alkylating agent are brought into contact in the presence of a Friedel-Crafts catalyst.

However, with this method, it was not possible to obtain a dialkylbenzene mixture in which the content of para isomers contained in the dialkylbenzene isomer mixture after the alkylation reaction was equal to or higher than the thermodynamic equilibrium composition. Therefore, in order to increase the yield of valadialkylbenzene, it was necessary to further subject the remaining ortho and meta forms after separating the para form from the reaction product to an isomerization reaction.

Furthermore, the Friedelta raft type catalyst is highly corrosive, requiring the use of equipment with a glass lining in the reaction system, and even then, it has the disadvantage that joints etc. are severely corroded. there were.

Under the above circumstances, various attempts have been made to selectively obtain baladialkylbenzene using catalysts other than Friedelta raft type catalysts.

Among these methods, the method of using crystalline aluminosilicate as a catalyst has attracted attention as a method in which the content of para-isomers can be increased above the thermodynamic equilibrium composition, and various studies have been conducted.

For example, JP-A-54-27528 discloses a method for producing baladialkylbenzene by bringing monoalkylbenzene and ethylene into contact with zeolite modified with a compound containing magnesium, phosphorus, and other elements to ethylate. There is.

However, as a result of retesting this method, although the selectivity of varaethyltoluene in ethyltoluene synthesis showed a high value (90% or more), it was difficult to obtain a high toluene conversion rate at the same time.

Furthermore, in JP-A-56-133032, 1,4-dialkylbenzene isomers are present in excess of the equilibrium concentration using crystalline zeolite modified with Group VIA metals such as molybdenum and tungsten as a catalyst. A method of making dialkylbenzene compounds is disclosed. However, although this method produces dialkylbenzene containing 1,4-dialkylbenzene at or above the thermodynamic equilibrium concentration, the para-selectivity is not necessarily high enough to be satisfactory, at about 30 to 70%. Ta.

In short, all of these conventional methods using modified zeolites as catalysts have the problem that it is not possible to achieve a value high enough to simultaneously satisfy both the selectivity of the para-isomer and the conversion rate of the raw material. Furthermore, it also has the disadvantage that the activity of the catalyst decreases in a relatively short period of time.

(Problems to be Solved by the Invention) Therefore, the present invention uses monoalkylbenzene and olefin as raw materials, uses a catalyst, and achieves high conversion and high selectivity.
Moreover, it is an object of the present invention to provide a method for producing baladialkylbenzene while maintaining high catalytic activity for a long period of time. Among other things, it is an object of the present invention to provide a method for producing baladialkylbenzene using a novel modified crystalline aluminosilicate as the catalyst.

In view of the current state of the art, the present inventors have conducted extensive research to achieve the above object, and as a result, have been able to adjust the proton exchange rate to a specific range, and have achieved Alternatively, it has been discovered that it is possible to produce baradialkylbenzene from benzene and olefin treated with a modifier containing two or more types of compounds with high conversion rate and high para-selectivity, and without deterioration of catalytic activity over a long period of time, We have arrived at the present invention.

[Structure of the invention]

That is, the present invention prepares monoalkylbenzene and olefin to have a proton exchange rate in the range of 25 to 80%,
The para-body is then reacted in the presence of a crystalline aluminosilicate catalyst obtained by treatment with a modifier containing one or more compounds selected from the group consisting of heteropolyacids and heteropolyacid salts. The present invention relates to a method for producing rich dialkylbenzene.

Crystalline aluminosilicates as base materials for the catalyst used in the process of the invention include, for example, natural zeolites such as mordenite, chabasite, erionite, and
These are synthetic zeolites such as type, Y type, and pentasil type.

In particular, it is preferable to use a so-called pentasil type synthetic zeolite in which the main pore entrance consists of a 10-membered oxygen ring. Furthermore, depending on the purpose of use, various metal salt types obtained by cation exchange or those subjected to appropriate treatment such as dealumination can also be used. Further, in the present invention, a crystalline metallosilicate in which part or all of the aluminum or silicon constituting the crystalline aluminosilicate is replaced with another metal such as gallium, germanium, or beryllium can also be used.

The crystalline aluminosilicate used in the present invention may be in the form of a powder or a molded product suitable for practical use. The binder to be mixed during the molding process is alumina sol,
You can use common materials such as clay.

The catalyst used in the method of the present invention is prepared by preparing the above-mentioned crystalline aluminosilicate so that the proton exchange rate is in the range of 25 to 80%, preferably 30 to 75%, and then subjected to a modification treatment.

Even if a modified crystalline aluminosilicate with a proton exchange rate of less than 25% is used as a catalyst, it is not possible to produce baladialkylbenzene at an industrially advantageous high conversion rate; This is because even if a modified crystalline aluminosilicate exceeding 50% is used as a catalyst, a high para selectivity cannot be obtained.

Proton exchange of crystalline aluminosilicate can be carried out without any problem by any known method, for example, a method using an acid aqueous solution, a method using an ammonium salt aqueous solution, etc. can be used as appropriate.

In addition, in the present invention, the proton exchange rate is defined by the following formula, taking sodium type crystalline aluminosilicate as an example.

Here, A: Amount of sodium eluted into the proton exchange treatment solution (g) B: Amount of crystalline aluminosilicate subjected to proton exchange treatment (g) C: Na in the crystalline aluminosilicate subjected to proton exchange treatment, 0 The concentration of sodium (weight %) indicated by A can be determined by measuring the sodium concentration in the treatment solution after proton exchange using a method such as atomic absorption spectrometry, and the concentration of Na, 0 indicated by C can be determined by , can be determined by decomposing crystalline aluminosilicate using hydrofluoric acid and measuring the sodium concentration in the decomposed solution using a similar method.

In the present invention, the proton exchange rate is further increased from 25 to
The crystalline aluminosilicate prepared in the 80% range is then treated with a heteropolyacid or its salt.

In the present invention, heteropolyacid is a general term for acids produced by the condensation of two or more inorganic oxygen acids, and the heteroatom (group I to II element) at the center of the heteropolyacid anion and oxygen Coordinating polyatoms (usually MO% W, Nb,
It can take various forms depending on the combination with V, etc.).

Various types of heteropolyacids can be used as the modifier for crystalline aluminosilicate in the present invention. Specifically, for example, 12-tungstophosphoric acid (8
3PW, □04°), 12-tungstosilicic acid (H4S
iW1 toa. ), 12-molybdophosphoric acid (H3PM
OIZ04G), 12-tungstogermanic acid (Hs
GeW+zO4o), 12-molybdogermanic acid (H
3GeMO+z04°).

Furthermore, the heteropolyacid salt used in the present invention is
Aluminum salts, alkali metal salts of the above heteropolyacids,
Alkaline earth metal salts and other metal salts such as 12
- Magnesium tungstosilicate, magnesium 12-tungstophosphate, manganese 12-tungstophosphate,
Zinc 12-tungstophosphate and the like.

These heteropolyacids or heteropolyacid salts are used by dissolving crystalline aluminosilicate and heteropolyacid or heteropolyacid salts prepared to have a proton exchange rate in the range of 25 to 80% in an inert solvent. From the viewpoint of industrial implementation, it is desirable to use one with high solubility.

Examples of the above-mentioned preferred suitable solvents include water, alcohols, ethers, ketones, and the like. The use of water is more preferred from the point of view of industrial practice.

In the present invention, the modification treatment for preparing the catalyst is performed by combining crystalline aluminosilicate prepared to have a proton exchange rate in the range of 25 to 80% and the above-mentioned modifying agent by various known methods such as dipping and spraying. This is done by making contact. The immersion temperature at that time may be any temperature that does not decompose the heteropolyacid or its salt. Approximately 10 to 30 due to ease of processing
Preferably it is ℃.

The contact time with the modifier in this treatment is approximately 30 minutes to 50 hours, preferably approximately 5 to 20 hours.

Further, the hydrogen ion concentration during the contact treatment can be appropriately adjusted to prevent the highly acidic heteropolyacid from deteriorating, and the contact treatment can also be carried out in a low pH range.

Note that the modifier is preferably applied in a proportion of about 1 to 50% by weight relative to the crystalline aluminosilicate containing about 30% by weight of a binder such as alumina sol.

After the above contact treatment, the crystalline aluminosilicate is filtered off and dried at a temperature of, for example, about 150° C. or lower. The purpose of this drying is to remove the solvent used to dissolve the modifier.

Then, it is fired in the presence of oxygen, air, or the like.

The firing is performed under conditions that do not alter the crystal structure of the crystalline aluminosilicate. For example, the firing temperature is approximately 40
The temperature is 0 to 650°C and the firing time is about 1 to 20 hours.

By this firing, the metal in the heteropolyacid or heteropolyacid salt comes to exist mainly on the outer surface of the crystalline aluminosilicate in the form of a metal oxide.

Note that this modification and firing process may be repeated several times.

The crystalline aluminosilicate modified in this way is
Depending on the purpose of use, it can be provided as a catalyst in a wide variety of shapes such as powder, granules, and pellets.

The production of the baladialkylbenzene of the present invention is carried out by subjecting a monoalkylbenzene to a catalytic reaction with an olefin in the presence of the catalyst obtained as described above.

Examples of the "monoalkylbenzene" in the present invention include toluene, ethylbenzene, and isopropylbenzene.

Examples of the olefin J in the present invention include ethylene and propylene.

The temperature of the catalytic reaction can be appropriately selected depending on the type of raw materials, that is, the combination of monoalkylbenzene and olefin, and is generally preferably about 300 to 500°C.

The reaction pressure is usually normal pressure to about 301 qr/ad, and preferably about 2 to 15 kg/cd, that is, the production method of the present invention carries out the reaction of monoalkylbenzene and olefin under pressure. Particularly favorable results are obtained in this case.

As for the reaction type, continuous type, semi-continuous type, etc. can be adopted using a fixed bed or fluidized bed catalyst system. From an industrial point of view, it is preferable from the viewpoint of safety and economy to carry out the process in a fixed bed continuous system under a pressure of 5 to 10 kg/-.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these specific examples.

Example 1 100g of sodium-type crystalline aluminosilicate with a pentasil-type silica/alumina molar ratio of 23 was mixed with 1) of 0
．． Added to 45% by weight ammonium chloride aqueous solution and added to 90~
It was treated at 95°C for 10 hours. Next, the crystalline aluminosilicate was filtered off and 1) dried at 0°C for 2 hours;
Further, it was fired in air at 520°C for 5 hours. As a result of analyzing the sodium concentration in the filtrate by atomic absorption spectrophotometry, the proton exchange rate was 48%.

Next, 30% by weight of alumina sol was added as a binder to the proton-exchanged crystalline aluminosilicate and molded. 1) After drying at 0°C for 2 hours, 520
C. for 16 hours. Next, 25 g of this shaped and calcined crystalline aluminosilicate was added to 100 g of a 10% by weight aqueous solution of 12-tungstophosphoric acid, and immersed for 16 hours at room temperature with gentle stirring. After soaking,
The crystalline aluminosilicate was filtered off, and the concentration of 12-tungstophosphoric acid in the filtrate was measured gravimetrically. As a result, the amount of 12-tungstophosphoric acid supported was 30% by weight. The filtered crystalline aluminosilicate was 1) dried at 0°C for 2 hours and then calcined at 610°C for 5 hours in the presence of air.

The crystalline aluminosilicate modified by the method described above was used as a catalyst in a reaction between toluene and ethylene.

The reaction was carried out using a flow reactor having a stainless steel reaction tube with an inner diameter of 10 mm and a length of 200 mm, and a raw material vaporization section and a preheating section at the front stage.

The reaction tube was heated by an electrothermal cylindrical electric furnace.

The catalyst loading was 2.6 g and the particle size was 20-42 mesh. The center temperature of the catalyst layer was 400° C., and the reaction pressure was 7 kg/cj. The toluene/ethylene molar ratio was 5, the hydrogen/ethylene molar ratio was 2, and the weight hourly space velocity was 10 h, -'.

The reaction products were analyzed by gas chromatography.

Table 1 shows the results 5 hours after starting the reaction.

Example 2 100g of crystalline aluminosilicate used in Example 1
was added to a 0.55% by weight ammonium chloride aqueous solution of No. 12 and treated at 90 to 95° C. for 10 hours to obtain a crystalline aluminosilicate with a proton exchange rate of 60%. After molding and firing this in the same manner as in Example 1, Example 1
Modification was carried out in the same manner as in Example 1, using 12-tungstosilicic acid instead of the 12-tungstophosphoric acid used in Example 1. A reaction between toluene and ethylene was carried out in the same manner and under the same conditions as in Example 1 using modified crystalline aluminosilicate as a catalyst.

Table 1 shows the results 5 hours after the start of the reaction.

Example 3 100g of crystalline aluminosilicate used in Example 1
was added to the 0.65% by weight aqueous ammonium chloride solution of 1) and treated at 90 to 95°C for 10 hours to obtain crystalline aluminosilicate with a proton exchange rate of 72%. molding,
After baking, it was modified using 12-tungstophosphoric acid under the same conditions as in Example 1. A reaction between toluene and ethylene was carried out in the same manner and under the same conditions as in Example 1 using modified crystalline aluminosilicate as a catalyst.

Table 1 shows the results 5 hours after the start of the reaction.

Example 4 100g of crystalline aluminosilicate used in Example 1
was treated with a 0.3% by weight aqueous ammonium chloride solution 1) to obtain a crystalline aluminosilicate with a proton exchange rate of 30%. This was molded and fired in the same manner as in Example 1. Next, 25 g of this shaped and fired crystalline aluminosilicate was mixed with 1 part of a 6% by weight aqueous solution of 12-tungstophosphoric acid.
00g and immersed for 12 hours at room temperature. The amount of 12-tungstophosphoric acid supported after filtration was 17 weight. The filtered crystalline aluminosilicate was dried and calcined in the same manner and under the same conditions as in Example 1, and then used as a catalyst in the reaction between toluene and ethylene. The reaction conditions were the same as in Example 1.

Table 1 shows the results 5 hours after the start of the reaction.

Example 5 100 g of sodium type crystalline aluminosilicate with a pentasil type silica/alumina molar ratio of 50 was mixed with 0.0 g of 1).
Added to 4% by weight ammonium chloride aqueous solution, 90-95%
C. for 10 hours to obtain crystalline aluminosilicate with a proton exchange rate of 60%. After molding and firing in the same manner as in Example 1, it was modified using 12-tungstosilicic acid instead of the 2-tungest phosphoric acid used in Example 1. The modified crystalline aluminosilicate was used as a catalyst for the reaction between toluene and ethylene. The reaction conditions were the same as in Example 1.

Table 1 shows the results 5 hours after the start of the reaction.

Example 6 The crystalline aluminosilicate with a proton exchange rate of 60% used in Example 2 was molded and fired in the same manner as in Example 1. Next, 25 g of the molded and calcined crystalline aluminosilicate was immersed in 100 g of a 2.0% by weight aqueous solution of 12-molybdophosphoric acid at room temperature for 10 hours. 12 after soaking
- The amount of molybdophosphoric acid supported was 4.1% by weight.

After calcining in the same manner as in Example 1, it was used as a catalyst in a reaction between toluene and ethylene. The reaction conditions were the same as in Example 1 except that the reaction pressure was 3 kg/cj.

Table 1 shows the results 5 hours after the start of the reaction.

Example 7 After molding and firing the crystalline aluminosilicate with a proton exchange rate of 60% used in Example 2, 25 g of it was
It was immersed in 100 g of a 5% by weight aqueous solution of 2-molybdosilicic acid at room temperature for 10 hours. The amount of 12-molybdosilicic acid supported after immersion was 6.0% by weight. After calcining in the same manner as in Example 1, it was used as a catalyst in a reaction between toluene and ethylene. The reaction conditions were the same as in Example 1 except that the reaction pressure was 3 kg/-.

Table 1 shows the results 5 hours after the start of the reaction.

Example 8 25 g of the molded and calcined crystalline aluminosilicate with a proton exchange rate of 72% used in Example 3 was mixed with a 5% by weight aqueous solution of heteropolyacid (this aqueous solution contained 12-tungstophosphoric acid and 12-molybdosilicic acid in a weight ratio of 4: 1) 10
0g for 10 hours at room temperature. The amount of heteropolyacid supported after immersion was 10% by weight. After calcining in the same manner as in Example 1, it was used as a catalyst in a reaction between toluene and ethylene. The reaction conditions were a reaction pressure of 3 kg/ca! It was the same as Example 1 except that.

Table 1 shows the results 5 hours after the start of the reaction.

Example 9 5 g of 12-tungstosilicic acid was dissolved in 301) 1) pure water, an excess amount of small pieces of clean magnesium ribbon was added thereto, and the mixture was allowed to stand at room temperature for 5 hours until no hydrogen was generated. 12- obtained by filtering off unreacted magnesium pieces
10 g of the molded and calcined crystalline aluminosilicate with a proton exchange rate of 72% used in Example 3 was added to the tungstomagnesium silicate aqueous solution, and the mixture was immersed at room temperature for 10 hours. The amount of magnesium 12-tungstosilicate supported after immersion was 15% by weight. After calcining in the same manner as in Example 1, it was used as a catalyst in a reaction between toluene and ethylene. The reaction conditions were the same as in the example except that the reaction pressure was 3 kg/d.

Table 1 shows the results 5 hours after the start of the reaction.

Example 10 A magnesium 12-tungstophosphate aqueous solution was prepared in the same manner as in Example 9 by reacting 12-tungstophosphate and magnesium metal. The molded and fired crystalline aluminosilicate with a proton exchange rate of 72% used in Example 3 was immersed in this aqueous solution in the same manner and under the same conditions as in Example 9. The amount of magnesium 12-tungstophosphate supported after immersion was 15% by weight. After calcining in the same manner as in Example 1, it was used as a catalyst in a reaction between toluene and ethylene. The reaction conditions were the same as in Example 1 except that the reaction pressure was 3 kg/-.

Table 1 shows the results 5 hours after the start of the reaction.

Example 1) A 12-tungstophosphoric acid manganese aqueous solution was prepared by reacting 12-tungstophosphoric acid and metal manganese in the same manner as in Example 9. The molded and fired crystalline aluminosilicate with a proton exchange rate of 72% used in Example 3 was immersed in this aqueous solution in the same manner and under the same conditions as in Example 9.

The supported amount of 12-tungstomanganese phosphate after soaking is 1
It was 6% by weight. After calcining in the same manner as in Example 1, it was used as a catalyst in a reaction between toluene and ethylene.

The reaction conditions were the same as in Example 1 except that the reaction pressure was 3 kg/-.

Table 1 shows the results 5 hours after the start of the reaction.

Example 1-2 An aqueous 2-tungstophosphoric acid zinc phosphate solution was prepared by reacting 12-tungstophosphoric acid and metallic zinc in the same manner as in Example 9. The molded and fired crystalline aluminosilicate with a proton exchange rate of 72% used in Example 3 was immersed in this aqueous solution in the same manner and under the same conditions as in Example 9. The amount of zinc 12-tungstophosphate supported after immersion was 14% by weight. After calcining in the same manner as in Example 1, it was used as a catalyst in a reaction between toluene and ethylene. The reaction conditions are
The procedure was the same as in Example 1 except that the reaction pressure was 3 kg/cJ.

Table 1 shows the results 5 hours after the start of the reaction.

Comparative Example 1 According to the method described in JP-A-54-27528,
The following operations were performed.

The crystalline aluminosilicate with a proton exchange rate of 48% used in Example 1 was molded using the same method and conditions as in Example 1.
Fired. Next, this was immersed in a 40% by weight aqueous magnesium acetate solution for 16 hours. The amount of magnesium acetate supported after immersion was 5% by weight as metallic magnesium.

The crystalline aluminosilicate supporting magnesium acetate was dried and calcined in the same manner as in Example 1, and then subjected to a reaction with toluene and ethylene as a catalyst. The reaction conditions were the same as in Example 1.

Table 1 shows the results 5 hours after the start of the reaction.

Comparative Example 2 The crystalline aluminosilicate used in Example 1 with a proton exchange rate of 48% was molded and calcined, and then used as a catalyst for a reaction with toluene and ethylene without being modified.

The reaction conditions were the same as in Example 1.

Table 1 shows the results 5 hours after the start of the reaction.

Comparative Example 3 The following operation was performed according to the method described in JP-A-56-133032.

The crystalline aluminosilicate used in Example 5 with a proton exchange rate of 60% was modified using ammonium paramolybdate. That is, 12 g of molded and fired crystalline aluminosilicate was mixed with 2 g of ammonium paramolybdate.
It was added to 80 g of a 5% by weight aqueous solution and immersed at 55° C. for 4 hours. The crystalline aluminosilicate separated by filtration was 90%
After drying at 500° C. for 3 hours, it was fired at 500° C. for 5 hours in the presence of air. The amount of ammonium paramolybdate supported is 30% by weight as metal molybdenum.
Met. The modified crystalline aluminosilicate was subjected to a reaction with toluene and ethylene as a catalyst. The reaction time was the same as in Example 1.

Table 1 shows the results 5 hours after the start of the reaction.

Comparative Example 4 The crystalline aluminosilicate used in Example 4 was 0.6
A crystalline aluminosilicate with a proton exchange rate of 90% was obtained by treatment with a 1N aqueous solution of ammonium chloride at % by weight. Next, this was modified with 12-tungstosilicic acid in the same manner as in Example 5.

After drying and calcining, it was subjected to a reaction with toluene and ethylene as catalysts. The reaction conditions were the same as in Example 1.

Table 1 shows the results 5 hours after the start of the reaction.

Comparative Example 5 The crystalline aluminosilicate used in Example 4 was treated with a 0.2% by weight ammonium chloride aqueous solution 1) to obtain a crystalline aluminosilicate with a proton exchange rate of 20%. Next, in the same manner as in Example 4, modification treatment was performed with l2-tungstosilicic acid. After drying and firing, the reaction conditions were the same as in Example 1, in which toluene and ethylene were used as catalysts for reaction.

Table 1 shows the results 5 hours after the start of the reaction.

Example 13 Catalyst used in Example 2, i.e. proton exchange rate 60%
A reaction between ethylbenzene and ethylene was carried out using a crystalline aluminosilicate modified with 12-tungstosilicic acid.

The same apparatus as in Example 1 was used for the reaction, and the reaction conditions were as follows. In other words, the center temperature of the catalyst layer is 400°C.
The reaction pressure was 10 kg/c+4, the ethylbenzene/ethylene molar ratio was 5, the hydrogen/ethylene molar ratio was 2, and the weight hourly space velocity was 20 h, -'.

Table 2 shows the conversion rate of ethylbenzene, the selectivity of para-ethylbenzene, and the yield 4 hours after the start of the reaction.

Example 14 The crystalline aluminosilicate used in Example 3, that is, the crystalline aluminosilicate with a proton exchange rate of 72%, was
-A reaction between toluene and propylene was carried out using a substance modified with tungstosilicic acid. The same apparatus as in Example 1 was used for the reaction, and the reaction conditions were as follows. That is, the center temperature of the catalyst layer is 400°C, and the reaction pressure is 8kg/c.
d,) The molar ratio of toluene/propylene is 5, the molar ratio of hydrogen/propylene is 2, the weight hourly space velocity is 10 h, -'
And so.

Table 2 shows the toluene conversion, paracymene selectivity, and yield 4 hours after starting the reaction.

Example 15 The crystalline aluminosilicate used in Example 2, that is, the crystalline aluminosilicate with a proton exchange rate of 60%, was
-The reaction between cumene and ethylene was carried out using a substance modified with tungstophosphoric acid. The same apparatus as in Example 1 was used for the reaction, and the reaction conditions were as follows. That is,
The center temperature of the catalyst layer is 380℃, and the reaction pressure is 5.0kg.
/ d, the molar ratio of cumene/ethylene is 5, the molar ratio of hydrogen/ethylene is 2.7, the weight hourly space velocity is 10 h
, -'.

Table 2 shows the conversion rate of cumene, selectivity and yield of paraisopropylethylbenzene 5 hours after starting the reaction.
Shown below.

Example 16 Catalyst used in Example 3, proton exchange rate 72%
Using a crystalline aluminosilicate modified with 12-tungstophosphoric acid, the change in catalyst activity over time in the reaction between toluene and ethylene was investigated. The reaction temperature is 40
The temperature was 0°C, but the temperature was 40°C 102 hours after starting the reaction.
From 0 to 425℃, same 1) From 425℃ to 45 after 5 hours
The temperature was raised to 0°C. Other reaction conditions were the same as in Example 1.

The results are shown in Table 3.

Comparative Example 6 The crystalline aluminosilicate with a proton exchange rate of 72% used in Example 3 was molded and fired, and then modified with magnesium acetate in the same manner and under the same conditions as in Comparative Example 1. The crystalline aluminosilicate supporting magnesium acetate was dried and calcined in the same manner as in Example 1, and then used as a catalyst in a reaction between toluene and ethylene, and changes in activity over time were investigated. The reaction conditions were the same I&- as in the NL experiment.

The results are shown in Table 3.

〔Effect of the invention〕

(1) According to the production method of the present invention, baladialkylbenzene can be produced with high monoalkylbenzene conversion and high para-selectivity.

That is, the present invention can provide a method for producing para-dialkylbenzene in which both the conversion rate and the para-selectivity are well-balanced and high, and as a result, the yield of para-dialkylbenzene can be further improved. It is possible.

(b) For example, as shown in Examples 1 to 12 in Table 1, according to the production method of the present invention, compared to Comparative Example 1, the para selectivity is almost the same, but the toluene conversion rate is about 3 to 5 times higher. In addition, compared to Comparative Example 3, the toluene conversion rate is almost the same, but the para selectivity can be improved by about twice, and as a result, p-ethyltoluene can be obtained in a high yield. be able to.

(b) Furthermore, as shown in Table 2, according to the production method of the present invention, various bara-dialkylbenzenes can be produced with high conversion rates and high bulk selectivity in various combinations other than toluene and ethylene. can.

(2) According to the production method of the present invention, baladialkylbenzene can be produced with high selectivity while maintaining the catalyst used at high activity for a long time. That is, as shown in Table 3, the production method of the present invention has high toluene conversion and bulk selectivity, and also shows a significantly small decrease in toluene conversion and bulk selectivity over time.

(3) Furthermore, as is clear from the results of Comparative Examples 2.4 and 5 in Table 1, the high conversion rate and high selectivity that are unique to the present invention are due to the fact that the catalyst used has a proton exchange rate of 25%. In the case of crystalline aluminosilicate prepared to a range other than ~80% and treated with a heteropolyacid, etc., or simply with a proton exchange rate of 25 to 80%.
This cannot be obtained if the crystalline aluminosilicate is prepared within the range of 1%.

(4) As a result of measuring the hue of the reaction liquid by Gardner number, it was 1 or less in the method according to the present invention (Example 9), and 3 to 4 in the method of Comparative Example 6 using a catalyst modified with magnesium acetate. The coloring of the reaction liquid is generally caused by high-boiling products, and therefore, according to the process for producing baladialkylbenzene of the present invention, in which there is almost no coloring of the reaction liquid, the desired bulk body can be easily recovered and purified. can do.

Claims (1)

[Claims] (1) Monoalkylbenzene and olefin are prepared to have a proton exchange rate in the range of 25 to 80%, and then treated with a modifier containing one or more compounds selected from the group consisting of heteropolyacids and heteropolyacids. A method for producing para-dialkylbenzene, which comprises carrying out the reaction in the presence of a crystalline aluminosilicate catalyst obtained by