JPS6314739A - Production of mono and/or dialkyl-substituted naphthalene - Google Patents

Abstract

PURPOSE:To obtain the titled compound in high conversion, by using a crystalline aluminosilicate, especially a faujasite-type zeolite as a catalyst and alkylating naphthalene or monomethylnaphthalene in the presence of a saturated alicyclic hydrocarbon. CONSTITUTION:The titled compound can be produced by contacting naphthalene or monomethylnaphthalene and an alkylating agent with a crystalline aluminosilicate (preferably a zeolite having relatively large pore diameter, especially a Y-type zeolite) in the presence of a saturated alicyclic hydrocarbon compound (especially preferably decalin or bicyclohexyl at an amount of preferably 0.2-10wt% based on naphthalene or monomethylnaphthalene). The alkylating agent is preferably selected from an alcohol of formula I (n is 1-4) and an ether of formula II. EFFECT:The aluminosilicate keeps high catalytic activity over a long period and has long catalytic life.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for alkylating naphthalene and/or monomethylnaphthalene.

More specifically, the present invention relates to a method for producing monoalkylnaphthalene and/or dialkylnaphthalene by bringing naphthalene and/or monomethylnaphthalene into contact with an alkylating agent and a crystalline aluminosilicate.

[Conventional technology]

A method of alkylating aromatic compounds using a Lewis acid such as AlCl3 as a catalyst is known as the Friedel-Crafts reaction. In particular, the method of alkylating naphthalene with propylene to obtain isopropylnaphthalene is well known. However, this alkylation method requires separation of the reaction product from the catalyst after the reaction is completed, and the catalyst has a tendency to corrode the equipment, making it economically disadvantageous.

On the other hand, a method of alkylating naphthalenes using a solid acid catalyst such as zeolite has not been well known.

The present inventors carried out alkylation reactions of naphthalenes using various zeolites. As a result, we found the following. That is, using ZSM-5 zeolite, β
When methylnaphthalene was methylated, the conversion rate of β-methylnaphthalene was extremely low. This is ZS
Although M-5 is often used in the alkylation reaction of benzene-based compounds and good results have been obtained, Z'S M-5 is often used in the alkylation reaction of naphthalene-based compounds whose molecular diameter is larger than that of benzene-based compounds. This is thought to be because the pore size of the pores is too narrow, which inhibits the diffusion of the naphthalene compound, which is the raw material, into the pores.

On the other hand, when mordenite was used as a catalyst, although the initial conversion rate of β-methylnaphthalene was quite high, it had the disadvantage of significantly deteriorating its activity.

In the alkylation reaction using Y-type zeolite as a catalyst and in the presence of a saturated alicyclic hydrocarbon compound, the activity deterioration is significantly improved, whereas in mordenite, the effect is reduced even when a saturated alicyclic hydrocarbon compound is present. was extremely small.

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[Problem that the invention seeks to solve]

Carrying out the alkylation reaction of naphthalene and/or monomethylnaphthalene using a solid acid catalyst,
A production method that achieves a high conversion rate and a long active life of the catalyst has not yet been established in the prior art.

For example, in JP-A No. 60-172939, when carrying out the methylation reaction of naphthalenes, a specific modified ZS
A method is disclosed in which a high conversion rate of raw materials and a long active life can be obtained by using M-5 zeolite. However, in order to obtain a high conversion rate, the reaction temperature must be between 400 and 45
It is necessary to raise the temperature to 0°C. This accelerates the reaction in which the methylating agent, for example methanol itself, changes into other olefins, the so-called MTG reaction, and increases the amount of by-products. In addition, WH3V, which is expressed as the supply 1 (g/Hr) of naphthalenes supplied per 1 g of catalyst, has to be as low as 1.011r-', which naturally reduces productivity, and industrial production It can be said that this method is not sufficient.

The present invention provides a method for producing mono- and/or dialkyl-substituted naphthalene that has excellent catalytic activity even at relatively low temperatures of 400°C or less and under high WH3V conditions, and maintains high activity for a long time. The purpose is to provide.

[Means to try to solve problems]

As a result of intensive research into alkylation methods for naphthalene and/or monomethylnaphthalene, the present inventors found that
The present invention was based on the discovery that a high conversion rate can be obtained by using a faujasite-type zeolite as a catalyst, and that the activity life can be significantly improved if the alkylation reaction is carried out in the presence of a saturated alicyclic hydrocarbon. It was completed.

That is, the present invention provides mono- and/or dialkyl-substituted naphthalene, which is characterized in that naphthalene and/or monomethylnaphthalene and an alkylating agent are brought into contact with a crystalline aluminosilicate in the presence of a saturated alicyclic hydrocarbon compound. This relates to a manufacturing method.

The most important feature of the present invention is that the alkylation reaction is carried out in the presence of a saturated alicyclic hydrocarbon compound supplied to the reaction system.

The "saturated alicyclic hydrocarbon compounds" used in the present invention include monocyclic compounds, polycyclic compounds that do not share ring carbons, polycyclic compounds that share ring carbons, fused alicyclic compounds, Examples include bridged alicyclic compounds. Specifically, monocyclic compounds include cyclohexane, cyclohebutane,
Examples include cyclooctane and cyclodecane. Examples of polycyclic compounds that do not share a ring carbon include bicyclopropyl, bicyclopentyl, bicyclohexyl, and cyclopentylcyclohexane. Polycyclic compounds that share a ring carbon include so-called spiran compounds, such as spiro C2,2) pepukun, spiro C2,3
]Hexane, Spiro[2,4) Hebutane, Spiro[3,
3] Hepkun, Spiro[3°4]octane, etc. As the fused alicyclic compound, bicyclo[4,2,
Examples include 0:1 octanehydroindane, decalin, perhydrophenanthrene, perhydroanthracene, and the like. Examples of the bridged alicyclic compound include norpinane, norbornane, and bicyclo[2,2,1:]octane. Among these, particularly preferred compounds include fused alicyclic compounds and polycyclic compounds, and specific examples include decalin and bicyclohexyl. Decalin includes cis-decalin and trans-decalin, and the effects of the present invention can be achieved no matter which one is used, and a mixture of the two is easily available and is preferred.

The supply amount of saturated alicyclic hydrocarbon compound is naphthalene and/or
Or, it is preferable to set it as the range of 0.1-20 weight ratio with respect to monomethylnaphthalene. Particularly suitable is a weight ratio of 0.2 to 10. This is because within this range, activity deterioration can be sufficiently prevented and high productivity can be maintained.

The saturated alicyclic hydrocarbon compound contains naphthalene and/or
Alternatively, it may be supplied together with monomethylnaphthalene or alone, as long as it is present in the reaction zone.

The crystalline aluminosilicate used in the present invention is preferably a zeolite with a relatively large pore size, preferably a faujasite type zeolite, and a Y type zeolite is particularly preferred.

As the Y-type zeolite, both natural zeolite and synthetic olide can be used. The cation sites of Y-type zeolite are usually occupied by alkali metals such as Na, but
Preference is given to those in which at least 25% and preferably at least 50% of the total cation sites are exchanged with hydrogen cations.

A known method can be used to exchange zeolite cations with hydrogen cations. That is, for example, hydrochloric acid,
After treatment with a mineral acid such as nitric acid or sulfuric acid or exchange with ammonium ions such as ammonium chloride, the ammonium ions can be converted into hydrogen cations by calcination.

Furthermore, ultra-stable Y-type zeolite, which has improved hydrothermal stability by containing 1.0% by weight or less of metal cations as oxides, can also be used. This is the full strength thion site 50
% or more is exchanged with hydrogen ions.

After heating at high temperature (e.g. 600-900℃) in the presence of steam.
), and it is also known that it can be obtained by repeating stepwise treatments with mineral acids, etc.

The zeolite used in the present invention can also be used in powder form. Moreover, by compression molding, it can be used as molded products such as pellets and tablets. When used as a molded product, a very common binder such as alumina sol or silica gel can be added to form a molded product.

The alkylation reaction of naphthalene and/or monomethylnaphthalene according to the present invention can be carried out either in the gas phase or in the liquid phase. The alkylation reaction is carried out under reduced pressure, normal pressure, or increased pressure, but generally the reaction rate is between normal pressure and 100 kg/kg.
ciG, particularly normal pressure to 20 kg/cTIiG is suitable. The reaction temperature is 150 to 500°C, preferably 2
00~400℃, more preferably 250~350℃
It is ℃.

When the reaction is carried out in a gas phase, it is preferable to carry out the reaction under a hydrogen stream in order to maintain a longer active life. The amount of hydrogen supplied is preferably in the range of 0.1-10 molar ratio to naphthalene and/or monomethylnaphthalene. Further, a gas such as nitrogen, carbon dioxide, or methane may be introduced.

The reaction is usually carried out using a fixed bed reactor, but it can also be carried out using a fluidized bed, moving bed or the like. At this time,
The weight hourly space velocity (WH3V) can be set in the range of 0.2 to 50 Hr'. More preferably WH3V is 1
~2011r-' range.

By setting WH3V within this range, productivity can be maintained at a high level, and since the contact time with the catalyst can be sufficiently long, a high conversion rate can be obtained. In addition, WH3V shown in the present invention is the unit time (H
r) shall represent the feed amount (g) of naphthalene and/or monomethylnaphthalene.

The alkylating agent used in the present invention includes general formula C,
, L,, +0H (n = 1-4) and the general formula (Cfi)12fi, I)20 (n
= 1 to 4), such as methanol, ethanol, impropatol, dimethyl ether, and the like. These can be used alone or as a mixture. The amount of alkylating agent supplied is preferably in a molar ratio of 0.2 to 2.0 relative to naphthalene and/or monomethylnaphthalene.

〔Effect of the invention〕

By carrying out the alkylation reaction of naphthalene and/or monomethylnaphthalene in the presence of the saturated alicyclic hydrocarbon compound shown in the present invention, the active life of the catalyst can be significantly shortened. Improved.

Further, according to the present invention, in the alkylation reaction of naphthalene and/or monomethylnaphthalene, faujasite-type zeolite, especially Y
A high conversion rate of raw materials can be achieved by using type zeolite. As shown in the comparative example described below, in ZSM-5, even if the reaction temperature is as high as 450° C., only an extremely low conversion rate can be obtained. On the other hand, in the examples of the present invention, even if the reaction temperature is as low as 300° C., a much higher conversion rate is obtained.

These features of the present invention are of great benefit in industrialization.

〔Example〕

Examples of the present invention will be shown below, but the present invention is not limited thereto.

Example 1 (1) 100 g of Y-type zeolite (TSZ-305 manufactured by Toyo Soda) containing 11.8% by weight of Na20 was taken and suspended in 1NNH4Cl aqueous solution 11. After stirring this at 95°C for 6 hours, it was filtered and thoroughly washed with water.

In addition, as a result of measuring the amount of Na eluted into the aqueous solution by atomic absorption spectrometry, it was found that 70% of Na cations had been exchanged with NH4 ions (Nl14-Y zeolite). dry NH,
10g of -Y zeolite was taken, suspended again in 100me of 1N NH,CI aqueous solution, stirred at 95°C for 6 hours, filtered, and thoroughly washed with water. In this product, 83% of the Na thione was exchanged to NH4 ion.

After drying, it was then fired in an electric furnace at 200°C for 1 hour and then at 500°C for 5 hours to obtain H-type zeolite (HY-1 zeolite).

(2) On the other hand, after drying the N)I, -Y zeolite, it was placed in a quartz tube and heat-treated at 700° C. for 1 hour with water vapor flowing through it. Subsequently, this product was suspended in IN NH,CI aqueous solution 11, stirred at 95°C for 6 hours, separated by filtration, and thoroughly washed with water. It was then dried and heat treated at 700° C. for 1 hour by passing water vapor through it. The Na2O content in the zeolite after treatment was 0.3% by weight. Looking at the X-ray diffraction pattern, the lattice constant decreased from 24.56 to 24.37 compared to the starting material NaY-type zeolite, resulting in contraction of the unit cell, but the Y-type crystallinity was impaired. (HY-2 zeolite).

(3) Alumina sol was added as a binder to the HY-1 or HY-2 zeolite obtained in the above operation so that the alumina content was 15% by weight, and the mixture was formed into pellets. Subsequently, it was fired at 200°C for 1 hour and at 500°C for 10 hours under air circulation. The molded product is lO~20
The particles were prepared to a mesh particle size and subjected to the reaction.

Example 2 and Comparative Example 1 5 g of I-I Y-2 zeolite prepared in Example 1 was packed into an atmospheric fixed bed reaction tube. After the catalyst layer was heated to 300°C, 50 g/row of a mixture of β-methylnaphthalene (refined product by recrystallization) and decalin at a weight ratio of 1/1 was added.
Methanol at 5.6 g/Hr and hydrogen at hydrogen/β
Methylnaphthalene-1,3/1 (11-l ratio) was fed (Example 2).

On the one hand, only β-methylnaphthalene was supplied at 25 g/llr without using decalin (Comparative Example 1).

The results are shown in Table 1. Although the conversion rates of β-methylnaphthalene at 0.5 hours after the start of the reaction were both high,
After time elapsed, the conversion rate of Comparative Example 1 became significantly lower.

In contrast, the results of Example 2 showed almost no deterioration in activity.

Examples 3 and 4 Same conditions as Example 2 except that Example 3 used H''l-1 zeolite instead of HY-2 zeolite, and Example 4 used bicyclohexyl instead of decalin. The reaction was carried out.

Comparative Examples 2 and 3 Instead of the saturated alicyclic hydrocarbon, n-hexane was used in Comparative Example 2, and n-decane was used in Comparative Example 3, which was a saturated chain hydrocarbon. As shown in Table 1, the active life of both products was extremely short and no effect was observed.

Examples 5.6 and 7 In Example 5, WH3V was increased to 1QHr-'.

Although a slight decrease in conversion rate was observed, almost no deterioration of activity was observed. In Examples 6 and 7, the amount of decalin supplied was changed to 2.0 and 0.5 (weight ratio) relative to β-methylnaphthalene, respectively.

When the amount of decalin supplied was increased, the conversion rate was further improved, and the activity increased in the reaction up to 6 hours. Although the effect on the active life becomes slightly smaller when the amount of decalin supplied is reduced, it is greatly improved compared to Comparative Example 1.

Comparative Example 4 ZSM with a silica/alumina molar ratio of 50 according to the method disclosed in U.S. Patent No. 3.766, 0/13.
After synthesizing -5 zeolite and making it H-type, alumina sol was added so that the alumina kumquat content was 15%, and the molded product was made into an IM. The reaction was carried out under the same conditions as in Example 2 except that the temperature was 450°C. As a result, although no deterioration in activity was observed, the conversion rate was extremely low.

Comparative Example 5 H-type mordenite (TSZ-640HOE manufactured by Toyo Soda)
The reaction was carried out under the same conditions as in Example 2, except that the temperature was 450°C. Although the conversion rate was relatively high in the early stage of the reaction, the active life was extremely short.

Example 8 and Comparative Example 6 Naphthalene (purified product by recrystallization) was used instead of β-methylnaphthalene. 50g of a liquid mixture of naphthalene and decalin at a naphthalene/decalin weight ratio of 1/1
Example 8 was carried out in the same manner as in Example 2, except that it was supplied using llr.

On the one hand, only naphthalene without decalin is used at 25
Comparative Example 6).

The results are shown in Table 2. Comparative Example 6 showed significant activity deterioration, whereas Example 8 showed almost no activity deterioration.

Examples 9 and 10 In Example 9, 4.1 g of ethanol was used as the alkylating agent.
/Hr, and Example 10 was carried out in the same manner as Example 8, except that Impropatool was supplied as an alkylating agent at 5.3 g/Hr.

The results are shown in Table-3.

As can be seen from Table 3, no rapid deterioration in the activity of the catalyst was observed in the alkylation reaction using ethanol and impropatol.

Claims (5)

[Claims] (1) naphthalene and/or monomethylnaphthalene and an alkylating agent in the presence of a saturated alicyclic hydrocarbon compound,
1. A method for producing a mono- and/or dialkyl-substituted naphthalene, which comprises bringing it into contact with a crystalline aluminosilicate. (2) The method according to claim (1), wherein the crystalline aluminosilicate is a faujasite type zeolite. (3) The method according to claims (1) and (2), wherein the crystalline aluminosilicate is Y-type zeolite. (4) The alkylating agent has the general formula C_nH_2_n_+_1
Claim (1) is at least one selected from alcohols represented by OH (n = 1 to 4) and ethers represented by the general formula (C_nH_2_n_+_1)_2O (n = 1 to 4) Method described. (5) The amount of saturated alicyclic hydrocarbon compound supplied is 0.2 to 1 per naphthalene and/or monomethylnaphthalene.
A method according to claim (1) in which the weight ratio is within the range of 0.