JPH01258633A - Method for isomerizing dichlorotoluene - Google Patents

Abstract

PURPOSE:To improve catalyst performances, by adding phosphorus and/or fluorine components to acid type zeolite containing rhenium and/or silver components as a catalyst in isomerizing dichlorotoluene in the presence of hydrogen. CONSTITUTION:A catalyst, obtained by adding (B) Re and/or Ag components to (A) an acid type substance of zeolite, especially mordenite type zeolite to improve deterioration in isomerization performances with time and further adding (C) P and/or F components to the catalyst to increase isomerization performances, simultaneously suppress side reaction and improve selectivity for isomerization reaction is used and an isomeric mixture of dichlorotoluene is brought into contact with the above-mentioned catalyst in the presence of hydrogen to efficiently isomerize the dichlorotoluene. Furthermore, the amounts of the added components (B) and (C) based on the total amount of the catalyst are preferably about 0.01-2.0wt.% Re, about 0.1-15wt.% Ag and 0.05-1wt.% P or F respectively expressed in terms of atoms.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to dichlorotoluene (hereinafter abbreviated as DCT).
Regarding the isomerization method.

<Prior art> -a, DCT is obtained by dichlorination of toluene, but this reaction is a reaction with strong orientation, and the types of isomers obtained and the production ratio of isomers are 2.4-DCT.
20-35%, 2,5-D, CT25-55%, 2.6
- D CT 5-25%, 2.3- D C78-1
2%, 3.4-DC75-12%. 3.5-DCT cannot be obtained by this reaction.
For the purpose of 5-DCT, it is necessary to isomerize DCT.

Each DCT isomer, as well as 3,5-DCT produced by isomerization, must be separated in order to be used as its m-isomer.

As methods for separating these isomers, they cannot be separated by distillation because their boiling points are close to each other. This can be achieved by a combination of

The remaining DC from which the target DCT isomer has been separated and removed
For the T isomer, it is economically extremely important to increase the target isomer concentration again through an isomerization reaction. Thereafter, the desired DCT isomer is separated and removed again, and this cycle is repeated.

As a method for carrying out such an isomerization reaction, JP-A-58-144330 discloses a method using mordenite-type zeolite, but the isomerization ability is insufficient and the isomerization ability decreases with the reaction time. This was not sufficient as an industrial method.

<Problems to be Solved by the Invention> These conventionally known isomerization catalysts do not have sufficient isomerization ability and deteriorate over time.
We have conducted extensive studies to solve these problems and to establish an industrially superior method for efficiently isomerizing DCT and increasing the concentration of the DCT isomer, which has a low concentration. the result,
The present inventors have already proposed that they can improve the aging deterioration of isomerization ability by adding rhenium or silver to acid-type zeolite. The present invention has been achieved based on the discovery that the isomerization ability can be increased or the side reactions can be suppressed and the selectivity to the isomerization reaction can be improved by adding/or a fluorine component.

Means for Solving the Problems〉 That is, the present invention provides hydrogen to a catalyst containing an acid form of a DCT'A substance mixture zeolite and (ro)rhenium and/or silver (ha)phosphorus and/or fluorine. The present invention provides a method for isomerizing DCT, which is characterized by contacting in the presence of DCT.

As the acid type zeolite used in the present invention, any zeolite can be used as long as it can isomerize the DCT isomer mixture, but particularly preferred among them are mordenite type zeolite, beta type zeolite,
Examples include pentasil type zeolite. Particularly preferred is mordenite type zeolite.

Methods for synthesizing mordenite-type zeolites are disclosed, for example, in Japanese Patent Publication No. 47-46677 and Japanese Patent Application Laid-Open No. 58-91032.

The most common way to identify a mordenite-type zeolite is by its X-ray diffraction pattern.

Table 1 shows the characteristic X-ray diffraction pattern of mordenite-type zeolite.

Table I X-ray diffraction pattern lattice spacing d (person) Intensity 13.6 ±0.2M 10.2 ±0.2W 9.0 ±0.2S 6.56 ±0. I S 6.40 +0.1 M 6.05 ±0.1W 5.80 ±0.1M 4.52 ±0.08 M 3.99 ±o, os s 3.83 ±o, os w 3.76 ±o, os w 3.53 ±0.05 W 3.46 +0.05 VS 3.38 ±0.05 3 3.28 ±0.05 W 3.20 ±0.05 3 3.15 ±0, 05 W 2.89 ±0.05 M 2.51 +0.05 W However, VS
is very strong, S is strong, M is moderately strong, and W is weak.
No. 8,069. The most common way to identify a beta zeolite is by its X-ray diffraction pattern. Table 2 shows the characteristic X-ray diffraction pattern of beta zeolite.

Table 2 X-ray diffraction pattern lattice spacing d (in) Intensity 11.7 90°2M 4.18 90°08M 3.98 +0.08 VS3.53 ±
o, os w 3.35 90°08 M 3.32 90°08 M 3.08 ±o, os w 2.69 90°08 W Here, VS is very strong, M is intermediate strong Well, W indicates weak.

A typical synthesis method for pentasil type zeolite is, for example, U
S P 3.702.886, USP 4.511.5
47. Pentasil type zeolite has a characteristic X-ray diffraction pattern shown in Table 3.

Table 3 X-ray diffraction pattern lattice spacing d (in) Intensity 11.2 ±0.2 S 10.1 ±0.2 3 9.8 ±0.2M 6.37 ±0. IW 6.00 ±0. IW 5.71 ±0. IW5.58
±0. IW 4.37 ±0.08 W 4.27 ±0.08 W 3.86 ±o, os vs 3.82 +0.08 VS3.75 ±
0.08 S 3.72 ±0.08 3 3.66 ±0.05 M 3.00 ±0.05 M 2.00 ±0.05 W Here, ■S is very strong; M indicates intermediate strength, W indicates weak.

The zeolite used in the isomerization reaction of the present invention is used in an acid form. As is well known, acid type zeolite can be obtained by converting cations in zeolite into hydrogen ions or polyvalent cations of divalent or higher valence. In particular, an acid form in which the cation is a hydrogen ion is highly active and preferred.

To convert cations in zeolite to hydrogen ions, usually
A method is performed in which zeolites 1 to 1 are directly ion-exchanged with an acid aqueous solution, or metal cations are ion-exchanged with ammonium ions, and then calcined. In addition, if the zeolite has organic nitrogen-containing cations in advance, it can be made into an acid-type zeolite by decomposing the organic nitrogen-containing cations and converting them into hydrogen ions by calcination.6 Of course, if necessary, the above-mentioned ion exchange It is also possible to ion-exchange alkali metal ions, such as sodium, present in the zeolite during its production by the method.

One of the essential components of the catalyst used in the present invention is rhenium and/or silver.

Rhenium is introduced into the catalyst by an impregnation method, a kneading method, or the like. Rhenium can be present in elemental form or in the form of compounds such as oxides, sulfides, selenides, etc., but in either case the catalyst contains about 0.0% of the total catalyst amount, with the rhenium component calculated as rhenium atoms. (b) Excellent results are obtained when the content is about 2.0% by weight. Particularly preferred is about 0.05% to about 1.0% by weight. Examples of what can be used as the rhenium component include perrhenic acid, ammonium perrhenate, and rhenium chloride. Silver is introduced by an ion exchange method, an impregnation method, a kneading method, etc. In either case, the catalyst is about 0.0% of the total catalyst amount, with the silver component being silver atoms.
Preferably it contains from 1% to about 15% by weight, especially from about 0.2% to about 10!1ffi%.

When silver is introduced into a zeolite component by an ion exchange method, ion exchange is generally performed with an aqueous solution, so it is essential that the silver compound that can be used be water-soluble, and silver nitrate is an example of this. I can do it.

Similar to the ion exchange method, the impregnation method is generally carried out in an aqueous solution, so the silver compounds used include water-soluble silver nitrate.6 However, in the impregnation method, silver ions are easily ion-exchanged with the zeolite. Therefore, it is considered to be essentially the same as the ion exchange method.

In the case of the kneading method, the silver compound does not necessarily have to be water-soluble, and may be an insoluble compound such as silver chloride or silver carbonate.

Among these methods, the ion exchange method is more preferable because it can uniformly disperse silver ions in the zeolite.

Note that phosphorus and/or fluorine components, which are essential components of the catalyst characteristically used in the present invention, are introduced by an impregnation method, a mixing method, or the like.

The phosphorus or fluorine component is 0.05% to 1% by weight of the total amount of the catalyst as phosphorus or fluorine atoms.
f! It is preferable to include the amount %.

Water-soluble FFE phosphorus compound ladles are preferred for use in measuring phosphorus content, and include, for example, phosphoric acid, ammonium phosphate, ammonium hydrogen phosphate, and the like.

The fluorine component that can be used is preferably a water-soluble fluorine compound, such as ammonium fluoride.

When such a catalyst is used in the present invention, it is usually used as a molded article.The molding method is not particularly limited, and transfer methods, extrusion methods, compression methods, etc. can be used. If necessary during molding, a binder such as alumina sol or karage may be added.

It should be noted that the ion exchange treatment or the addition of a rhenium component is preferably carried out after molding in order to save on catalyst preparation. and use it as a catalyst.

Another essential requirement constituting the isomerization method of the present invention is the presence of hydrogen during the isomerization reaction.

The amount of hydrogen present is, for a certain D C'r of the feedstock,
A molar ratio of 0.003 mol or more is required, and since too much is disadvantageous in terms of economic efficiency, the upper limit is determined depending on the economic efficiency.

Usually less than 1 mole of 10-T,! ), the isomerization method of the present invention is directed to the target DCT isomer:
In the presence of the CT isomer phoneme, (a) acidic f water of zeolite is brought into contact with a catalyst containing (0) rhenium and/or silver component (/'+1 phosphorus and/or fluorine component). make it happen.

Such a reaction can be carried out according to various conventionally known isomerization operations, and may be either a gas phase reaction or a liquid phase reaction.

However, a more preferred method is a method in which DCT is brought into a liquid phase state and hydrogen gas is isomerized in a state in which at least a portion of hydrogen gas is dissolved in the liquid phase DCT. Formed on catalyst1.
When high-boiling products react in a liquid phase, liquid phase DCT
However, when it is in use, it remains on the catalyst and becomes a coke component, which tends to poison the catalyst's activity.

Further, any of fixed bed, moving bed, and fluidized bed methods may be used, but fixed bed flow reaction is particularly preferred from the viewpoint of ease of operation.

The reaction temperature is usually about 200 to 500°C, but especially 2
50-450°C is preferred. Although the reaction pressure is not particularly limited, it goes without saying that in the case of a liquid phase reaction, the reaction pressure must be set to maintain the reaction system in a liquid phase state.

The weight space velocity (1411sV) is 0.05 to 1. OH
r-1, preferably 0.1 = -5Hr-1.

The dichlorotoluene isomers obtained by this 1-isomerization are separated by an adsorption separation method and/or a distillation method.

These π-isomers are intermediates for pharmaceuticals and agricultural chemicals! -Used as such.

<Example> Hereinafter, the present invention will be explained with reference to examples! I will explain it as a whole.

Example 1 Synthetic mordenite-type zeolite 1-(Si02/AJ!2
03 ratio 19.5 mol 1 mol) powder, add alumina sol A
X5 wt% (calculated as L2Q3) was added, kneaded, extruded into 14 to 24 meshes, dried overnight at about 120°C, and then fired in air at 540°C for 12 hours. The solid-liquid ratio of the Mordenai 1 to 2 molded bodies was prepared using an IQwt% ammonium chloride aqueous solution. (b) / lqr, ion-exchanged 5 times at about 90°C and thoroughly washed with water.Next, this ammonium ion-exchanged zeolite 1 was dried overnight at 120°C, and 30g was collected on an absolutely dry basis. Ammonium fluoride 3.33
This zeolite 1 was immersed in a solution prepared by dissolving 7.g in 90 ml of distilled water and left at room temperature for 3 hours.

Thereafter, the liquid was drained, and the sample was immersed in perrhenic acid Mizutake-numa containing 0.06 g of metal rhenium (17), and left at room temperature for 3 hours. Thereafter, the liquid was drained again, dried at about 120°C overnight, and then baked at 540°C for 2 hours. The rhenium content contained in this catalyst was analyzed and found to be 0.09 wt%, and the fluorine content was analyzed to be 0.45 wt%.
Met.

Using this catalyst, a fixed bed flow reactor was used, and D
The isomerization reaction of CT was carried out in the presence of hydrogen.

The results are shown in Table 4.

Example 2 A catalyst was prepared in the same manner as in Example 1. However, the ammonium fluoride used was 1.6 g instead of 3.33 g.
It was set to 7tr.

The result of analyzing the rhenium content contained in the catalyst is 0.09
wt%, and the result of analyzing the fluorine content was 0.29.
It was wt%. Table 4 shows the results of a reaction using this catalyst in a fixed bed flow reactor.

Comparative Example 1 Synthetic mordenite zeolite (SiO2/Al2O3
Aj!
Added 15 wt% (calculated as 203), kneaded it, extruded it into a 14-24 mesh, dried it at about 120°C overnight,
It was baked in air at 0°C for 2 hours. This mordenite molded body was treated with a 10 wt% ammonium chloride aqueous solution at a solid-liquid ratio of 2. Oj! / kg was subjected to ion exchange five times at about 90°C and thoroughly washed with water.

The ammonium ion-exchanged zeolite was then dried at 120°C overnight, and then calcined at 540°C for 2 hours.

Table 4 shows the results of a reaction using this catalyst in a fixed bed flow reactor.

Comparative Example 2 Synthetic mordenite zeolite (Sto2/Aj!20
3 ratio 19.5 mol 1 mol) powder, add alumina sol to Aj
! 15 wt% (calculated as 203) was added, kneaded, extruded into a 14-24 mesh, dried overnight at about 120°C,
It was baked in air at 0°C for 2 hours. This mordenite molded body was treated with a 10 wt% ammonium chloride aqueous solution to a solid-liquid ratio of 2. OJ! The sample was ion-exchanged 5 times at +r approximately 90°C and thoroughly washed with water.

Next, this ammonium ion-exchanged zeolite was dried at 120° C. overnight, and 30 g was collected on an absolutely dry basis. This zeolite was immersed in an aqueous perrhenic acid solution containing 06 g of rhenium as a metal and left at room temperature for 3 hours. Drain the soaking liquid, dry it overnight at about 120℃, and then dry it at about 540℃.
C. for 2 hours. Analysis of the rhenium content in this catalyst revealed that it was 0.09 wt%.

Table 4 shows the results of a reaction using this catalyst in a fixed bed flow reactor.

Table 4 Catalyst performance evaluation Note) B, T, X: Benzene, toluene, xylene CB:
Chlorobenzene CT: Chlorotoluene DCB Nidichlorobenzene DCX: Dichloroxylene Example 3 Zeolite was molded in the same manner as in Example 1, and after firing, ammonium ion exchanged zeolite was dry-smoked at 120°C overnight and 30g was collected.

Zeolite was ion-exchanged with a silver nitrate aqueous solution containing 1.5 g of tin metal at room temperature at a solid-liquid rate of 2β/kt. After washing thoroughly with water, it was immersed in an aqueous solution containing 1.67 g of ammonium fluoride at a solid-liquid ratio of 3β/k+r, and left for 3 hours. Thereafter, the liquid was drained, dried at about 120°C overnight, and then baked at 5110°C for 2 hours. The amount of silver and gold contained in this catalyst was 4.2 wt%, and the content of fluorine was 0.28 wt%.

Using this catalyst, a fixed bed flow reactor was used, and D
The isomerization reaction of CT was carried out in the presence of hydrogen. The results are shown in Table 5.

Fruit 811! Example 4 After molding and firing in the same manner as in Example 1, ammonium ion-exchanged zeolite was dried at 120°C overnight, and 30+r was collected on an absolute dry basis. Zeolite was solidified and liquefied at room temperature with a silver nitrate aqueous solution containing 1.5 g of tin metal.
Ion exchange was carried out using kg. After washing thoroughly with water, the solid-liquid ratio of 2 l was added to an aqueous solution containing 0.394 g of ammonium phosphate.
/ kr'''C and left for 3 hours.Then the liquid was drained and dried overnight at about 120°C, then 540'C12
Baked for an hour. The amount of silver and gold contained in this catalyst is 4.
3 W t%, and the phosphorus content was 0.08 w t%.

Using this catalyst, an isomerization reaction of DCT was carried out in the liquid phase in the presence of hydrogen using a fixed bed flow reactor. The results are shown in Table 5.

Comparative Example 3 A catalyst was prepared in the same manner as in Example 3. However, no treatment with ammonium fluoride was performed.

Using this catalyst, a fixed bed flow reactor was used, and D
The isomerization reaction of CT was carried out in the presence of hydrogen. The results are shown in Table 5.

Since the isomerization ability is lower than that of a catalyst treated with ammonium fluoride or ammonium phosphate, the reaction temperature needs to be raised by 15° C. to show the same level of isomerization ability.

Example 5 A zeolite which was molded in the same manner as in Example 1 and subjected to ammonium ion exchange after firing was dried at 120° C. overnight, and 30 g was collected on an absolutely dry basis. Zeolite was mixed with a silver nitrate aqueous solution containing 0.6 ir as tin metal at room temperature at a solid-liquid ratio of 2 fl /
' Do ion exchange with kg.

Then, after thorough washing with water, form an aqueous solution containing 3°33g of ammonium fluoride and a solid-liquid ratio of 2j! / kg and left at room temperature for 3 hours. After that, drain the liquid and remove the rhenium as a metal.
It was immersed in a perrhenic acid aqueous solution containing 406+r and left at room temperature for 3 hours. Thereafter, the liquid was drained again, dried at about 120°C overnight, and then baked at 540°C for 2 hours. Silver present in the catalyst is 1.9 wt%, rhenium is 0.9
wt,%, fluorine was 0.42 wt%.

Using this catalyst, a fixed bed flow reactor was used, and D
The isomerization reaction of CT was carried out in the presence of hydrogen. The results are shown in Table 5.

Table 5 Catalyst Performance Evaluation Example 6 2 volumes of tetraethylammonium hydroxide aqueous solution (containing f, 20%) 47, oir, and 17.8 g of a sodium aluminate aqueous solution were dissolved in 332.3 g of water. 53.5 g of gaic acid was added to this solution and stirred to prepare an aqueous mixture slurry. Its composition expressed in molar ratio was as follows.

S i O2/ Abu203 25PN+/(R
N++Na) 0.3050 H/SiO
A slurry of the mixture of 20,246 H20/OH (24) was charged into a 500 ml O-1-crepe, and after sealing, the temperature was raised to 160°C and reacted for 7 days with stirring. Thereafter, the mixture was cooled, filtered, washed five times, and dried at about 120° C. overnight.

The obtained product was measured by X-ray diffraction, and the X-ray diffraction pattern was substantially the same as that of mordenite-type zeolite shown in Table 1.

Example 7 A catalyst was prepared in the same manner as in Example 1 using the mordenite zeolite synthesized in Example 6.

Using this catalyst, a fixed bed flow reactor was used, and D
The isomerization reaction of CT was carried out in the presence of hydrogen.

The results are shown in Table 6.

Example 8 A catalyst was prepared using the mordenite zeolite synthesized in Example 6 as follows.

Add alumina sol to mordenite type zeolite powder
After adding 15 wt% in terms of 2203 and kneading, 14 to 24
After extrusion molding into mesh and drying at about 120℃ overnight,
It was baked in air at 40°C for 2 hours. A mordenite molded body with a Lowt% ammonium chloride aqueous solution was used to reduce the solid-liquid ratio to 2.0! / kg Ion-exchanged 5 times at about 90° C. and thoroughly washed with water. Next, this ammonium ion-exchanged zeolite was dried overnight at 120° C., and 30 g on an absolutely dry basis was collected. 09394 g of ammonium phosphate was taken and dissolved in an aqueous perrhenic acid solution containing 0.06 g of rhenium.

Zeolite was immersed in this mixture and left at room temperature for 3 hours. The soaked liquid was drained and dried at 120°C overnight, then at 540°C.
'C was fired for 12 hours.

Using this catalyst, a fixed bed flow reactor was used, and D
The isomerization reaction of CT was carried out in the presence of hydrogen.

The results are shown in Table 6.

Table 6 Catalyst Performance Evaluation <Effects of the Invention> According to the present invention, there is provided a method for gastric conversion of dichlorotoluene in which the isomerization ability is increased, side reactions are suppressed, and selectivity to the isomerization reaction is improved. I can do it.

Claims (2)

[Claims] (1) Bringing the dichlorotoluene isomer mixture into contact with a catalyst containing (a) an acid form of zeolite, (b) a rhenium and/or silver component, and (c) a phosphorus and/or fluorine component in the presence of hydrogen. Characteristic isomerization method of dichlorotoluene. (2) The method for isomerizing dichlorotoluene according to claim (1), wherein the zeolite is a mordenite type zeolite.