JPS6245544A - Production of cycloolefin - Google Patents

Abstract

PURPOSE:To obtain the aimed substance in high selectivity and yield, by partially reducing a monocyclic aromatic hydrocarbon in the presence of reduced Ru prepared by previously incorporating zinc therein as a hydrogenation catalyst and coexisting water and a water-soluble zinc compound under acidic conditions. CONSTITUTION:A monocyclic aromatic hydrocarbon, e.g. benzene or toluene, is reduced in the presence of a hydrogenation catalyst, water and a water-soluble zinc compound at 100-200 deg.C under 10-100kg/cm<2>G hydrogen pressure to give the aimed substance. The hydrogenation catalyst is preferably reduced Ru prepared by previously incorporating zinc therein and obtained by reducing a valent Ru compound containing 0.1-50wt%, preferably 2-20wt%, based on Ru, zinc until the Ru attains metallic state. The catalyst having <=200Angstrom , preferably <=100Angstrom average crystal diameter is suitable. USE:A raw material for polyamides and lysine.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention provides cycloolefins that partially reduce monocyclic aromatic hydrocarbons with high selectivity and high yield.

In particular, it relates to a method for producing cyclohexenes.

Cyclohexenes have high value as intermediate raw materials for organic chemical industrial products, and are particularly important as raw materials for polyamides, lysine, etc.

(Prior art) As a method for producing such cyclohexanes! ``i, e.g. +1) Water and an alkali agent and a method using a catalyst composition containing the elements No.
(2) A method in which a ruthenium catalyst is supported on a nickel, cobalt, chromium, titanium or zirconium acid and used as an alcohol or ester total additive (Usunko I+352-5955) 1
31 steel, using a ruthenium catalyst containing silver, cobalt or potassium, water and a phosphate compound f:
(% Shuro No. 56-4556), (4) Ruthenium catalyst is at least 1d selected from metals of group IA of the periodic table, metals of group HA, manganese, zinc, and ammonia.
A method of conducting a reaction in the presence of an acidic aqueous solution containing a cationic salt in a neutral cylinder (Japanese Patent Application Laid-Open No. 142536/1983)
, (5) a solid catalyst containing at least one of ruthenium and rhodium as a main component, a group IA metal of the periodic table, a salt of at least one cation selected from the group consisting of group A metals, manganese, iron and zinc; A method in which the reaction is carried out in the presence of water using a water bath solution containing
-98245 Publication), (A method of performing anti-Gk by using a 61 ruthenium flux and adding at least 1 scoop of zinc oxide and zinc hydroxide to the system as an activating component (%Kokai No. 59-184138) ) have been proposed.

(Problems to be Solved by the Invention) However, in these conventionally known methods, in order to increase the selectivity of the target cyclohexene, it is necessary to significantly suppress the conversion rate of the raw material, or to increase the reaction rate. At present, the yield and productivity of cyclohexenes are generally low, such as the speed is extremely low, and it is not a practical method for producing cyclohexanes 7.

(Determined means for solving the problem) In order to solve the problem 'fc, the present inventors have proposed hydrogenation in a partial reduction method of monocyclic aromatic hydrocarbons in order to improve the selectivity and yield of cyclohexene. As a result of extensive research into catalysts, we have arrived at the present invention. That is, by using a reduced product of ruthenium containing zinc in advance as a hydrogen hydrogen catalyst and carrying out the anti-Ck reaction under acidic conditions in the coexistence of water and at least one type of water-soluble zinc compound, They have discovered that cyclohexenes can be obtained with extremely low fc selectivity and yield, which is unprecedented.

Hereinafter, specific embodiments of the present invention will be described.

What is the monoaromatic aromatic carbon arsenide that is the raw material of the present invention?

Refers to benzene, toluene, xylene a, and lower alkylbenzenes.

The hydrogen ratio catalyst in the present invention is a reduced product of ruthenium containing zinc in advance.

More specifically, such a catalyst is a reduced product obtained by pre-containing a zinc compound in a valuable ruthenium compound, followed by reduction, and ruthenium is reduced in the metallic state 1. Valuable ruthenium compounds that can be used are, for example, chlorides.

<Salts such as old acid salt disulfate, complexes such as ammine complex salts,
Among the hydroxides, oxides, etc., trivalent or tetravalent ruthenium compounds are particularly preferred because they are easily available and easy to handle.

Further, a wide range of zinc compounds can be used, including salts such as chlorides, nitrates, and sulfates, complexes such as ammine complexes, hydroxides, and oxides.

It is not necessarily clear why such catalysts are effective as catalysts for the production of cycloolefins, but
It can be considered that during the process in which a valuable ruthenium compound is reduced to a metallic state, the coexisting zinc r-arsenium compound reveals or increases the total number of active sites that are advantageous for the production of cycloolefins.

The zinc content in the catalyst in the present invention is adjusted to J1 to 50 Mf4%, preferably 2 to 20 Ft, based on the ruthenium product. Therefore, the main component of the catalyst is ruthenium, and zinc is not a carrier.

Further, in JP-A-51-98243, there is a statement that it is preferable to use a ruthenium catalyst treated with an aqueous solution containing a salt of a zinc cation, but there is no mention of whether or not zinc is contained. It is also clear that all catalyst treatments are performed on reduced catalysts, which are fundamentally different from the catalysts used in the present invention.

The smaller the average crystallite diameter of the reduced product, the more useful the present invention becomes.
Below, preferably 1008 or less is desirable in order to improve the selectivity of cycloolefin.

The valuable ruthenium compound containing zinc in the present invention may be obtained as a two-piece product by a general coprecipitation method using a mixed bath solution of zinc and ruthenium compounds, or in the form of a homogeneous solution. You may get it. The catalyst of the present invention is prepared by reducing the valuable ruthenium compound containing all of zinc until the ruthenium becomes a metal layer. As the reduction method, a general ruthenium reduction method may be used. I can do it. For example, methods of reduction with hydrogen in the gas phase, hydrogen or a suitable chemical reducing agent, such as NaBH, in the liquid phase.

A method of reduction using sound, such as formalin or formalin, is preferable [δ
Method 1: Reduction using hydrogen in gas phase or liquid phase
When reducing with hydrogen in the b0 gas phase, it is necessary to avoid extreme temperatures or dilute the hydrogen with other inert gases in order to increase the crystallite size. In addition, when reducing in a liquid phase, it may be carried out by dispersing a solid valuable ruthenium compound containing zinc in water or alcohol, or it may be carried out in the form of a homogeneous solution. At this time, it is recommended to perform appropriate stirring, heating, etc. in order to make the reduction proceed better. Also, instead of water, use an aqueous alkali solution or a suitable aqueous metal salt solution, such as an aqueous alkali metal salt solution. Good too.

Here, the crystallite diameter of the catalyst is determined by a general method, that is, from the expansion of the diffraction line width obtained by X-ray diffraction method;
It is calculated using Cherrer's formula.

Specifically, when CuKα rays are used as the X-ray source, it is calculated from the spread of the ta+ fold line, which has a maximum total around 44° at the diffraction angle (2θ).

As mentioned above, the average crystallite diameter is 200X or less, preferably 1008 or less, and the lower limit is larger than the theoretical crystal unit, and the practical size ζ is 10A or moreC.

In the present invention, the coexistence of water is necessary. Depending on the type of water, it can be mixed in amounts of 0.01 to 100 times the amount of aromatic carbon and arsenic used in general. However, under anti-16 conditions, it is preferable that two phases, an organic liquid phase mainly composed of raw materials and products, and a liquid phase containing water, form a homogeneous phase under one reaction condition. The coexistence of an extremely small amount of water or the coexistence of an extremely large amount of l-1 water has the effect (i-reduction ε17).If the amount of water is large, there is a sense of security in enlarging the reactor. Practically speaking, it is desirable that they coexist by 0.5 to 20 times by weight.

In the present invention, in addition to the hydrogenation catalyst and water, at least one
The presence of a species of water-soluble zinc compound is required. Here, as the water-soluble zinc compound, various salts are used, such as weak acid salts such as carbonates and acetates, and strong acid salts such as hydrochlorides, nitrates, and sulfates. Zinc oxide and zinc hydroxide are also effectively used. The amount to be used is 1 x 10-5 to 1 times the amount of water coexisting during the reaction, preferably 1 x 1
0-'~υ, 1M fluorescence magnification. It is not particularly necessary that the entire amount of the zinc compound used be dissolved in the water coexisting during the reaction.

For example, there is a description in Japanese Patent Application Laid-open No. 142536/1983 that allows zinc f-arsenide to coexist in water, but a catalyst supported by ruthenium or rhodium gold is used, and the present invention The catalyst itself is different from that of the present invention, and the selectivity of cycloolefin is low. -1 Example of adding at least 10,000 of zinc arsenic acid and zinc hydroxide (JP-A-59
184138), the catalyst used is different and it is said that it is preferable to carry out the process under alkaline conditions, which is different from the present invention.

[5] In addition to water-soluble zinc and arsenic compounds, various metals, such as periodic table IA group elements, IA group elements J.] Salts such as manganese, cobalt, and copper may also be present.

Further, in the present invention, preferable results can be obtained by carrying out the reaction under the conditions of a coexisting aqueous phase. If the aqueous phase is made completely neutral or alkaline, the reaction rate will drop significantly, making it difficult to find a realistic artificial method. Also, to make it acidic, use regular acid, da! For example, hydrochloric acid, nitric acid, sulfuric acid, acetic acid, phosphoric acid, etc. are acceptable. In particular, sulfuric acid requires 2 reactors. It is extremely effective in encouraging courage. The pH of the aqueous phase thus introduced into the l·Ecore system is between 0.5 and less than 7.0, preferably between 2 and 6.5.
It is.

Partial reduction reaction [6 is) Karasu L in the method of the present invention:; *
It is carried out continuously or batchwise by a suspended phase suspension method, but it can also be carried out by a stationary phase method. The reaction conditions are appropriately selected depending on the type and amount of the catalyst and additives used, but the hydrogen pressure is usually 1 to 200 kg/clG, preferably 1
The reaction temperature is in the range of 0 to 100 kg/crdG, and the reaction temperature is in the range of room temperature to 250C, preferably 100 to 200C. The IL reaction time may be selected as appropriate by determining the selectivity of the desired cyclohexene and the substantial target value of the yield, and is not particularly limited, but is usually several seconds to several hours.

(Effects of the Invention) According to the present invention, cycloolefins can be obtained with unprecedentedly high selectivity and yield, and are of extremely high value industrially.

(Examples) Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way.

Example 1 Ruthenium chloride (RuC4-3H,O) 5.0? and zinc chloride13. Dissolve Of in 500% of water and stir,
Add a 30% aqueous solution of caustic soda to this at a temperature of 70°C, and stir the mixture for 2 hours at 180C.

After cooling and standing, the black precipitate that settled was washed three times with 1N NaOH aqueous solution by decantation. This black precipitate is mostly Ru(OH) containing Zn(OH), and some of it exists in the form of chloride. Caustic soda aqueous solution of this black precipitate sound 50
After dispersing the mixture in an area of 0 ml and charging it into an autoclave with an inner volume of 1 ton and whose inner surface was coated with Teflon, the total pressure was brought to 50 Y/da with hydrogen, and the mixture was reduced at 150 C for 12 hours.

After cooling, the obtained black powder was heated under an argon atmosphere for 30 minutes.
After washing with an aqueous NaOH solution, the mixture was further washed with water and vacuum dried to obtain a black catalyst with a hydrogen ratio of 2.3y.

When this catalyst was analyzed by X-ray diffraction, crystal growth was observed, and the average crystallite diameter was 55X. On the other hand, when the zinc content in this catalyst was determined by fluorescent X-ray method, it was found to be 7.
．． It was 4 times i%.

Next, partial reduction of benzene was performed using this catalyst.

The above catalyst 0.47, water 620-1ZnSO, 7 H,
014,49 and benzene 80ml1. The inner surface was coated with Teflon and placed in an autoclave with an internal volume of 1 ton. After heating at 150C-i, hydrogen was injected to bring the total pressure to 50.
9/crdG, and the reaction was carried out under high speed stirring. This reaction solution was extracted over time, and the composition of the oil phase was analyzed by gas chromatography.The results are shown below.

15 minutes 22.1 87.8 19.43
0 min 39.0 B 4.0 32.8
60 minutes 60.5 78.7 47.5 The by-product was cyclohexane.

Example 2 The same operation as in Example 1 was performed, except that the black precipitate before reduction was dried in an iAr stream and then reduced with hydrogen in the gas phase. The results are shown below.

15 minutes 20.4 83.9 17.130
Minutes 56.0 80.1 28.860 minutes
56.1 75,3 42.2 Example 3 Ruthenium chloride (RuC1,'3H!O) 1,56
L? , zinc sulfate (Zn5O, -7H!0) 0.26
? Dissolve 0.9v of IJium in 100ml of water, add gold to reduce, wash and dry to obtain a hydrogenation catalyst of 0.61.
I got it. Zinc content is 2.6% by weight, average crystallite size is 40
It was a person.

A reaction was carried out in the same manner as in Example 1 using this hydrogenation catalyst. The results are shown below.

15 minutes 25.8 80.9 20.93
0 minutes 44.1 75.2 53.260
Minutes 68,5 66,9 45.8 Comparative Example 1 Ruthenium metal from Nippon Engel/%Rudosha (average crystallite diameter 5ooi or more) as a hydrogenation catalyst 0,! The friends using M"i performed the same operations as in Example 1. The results are shown below.

50 minutes 7.8 15.5 1.260
min 14.5 6.4 0.9120 min 27.7 2.5 0.7 The effectiveness of the hydrogenation catalyst in the process of the invention is evident.

Comparative Example 2 In a similar manner to Example 1 without zinc chloride during catalyst preparation,
The reaction was carried out in the same manner as in Example 1, except that metal ruthenium gold with an average crystallite size of 59 was prepared and used as a hydrogenation catalyst. The results are shown below.

15 minutes 23.4 73.0 17.13
0 minutes 40.3 67.0 27.060
Minutes 62.1 52.5 32. This clearly shows the superiority of the catalyst in the method of the present invention among catalysts having approximately the same average crystallite diameter.

Comparative Example 3 Ruthenium was supported using a ruthenium chloride aqueous solution and zinc oxide powder by a normal liquid phase adsorption support method, and then reduced with hydrogen to make a hydrogen 1-hydrogen catalyst in which 1% by weight of metal ruthenium was supported on zinc oxide. 4. The reaction was carried out in the same manner as in Example 1, except that Ori was used. The results are shown below.

15 minutes 20.5 40.5 8.330
Minutes 36.7 24.8 9j60 minutes
5ζ2 14,9 7. It is clear that the metal ruthenium catalyst using all zinc as a carrier is significantly different from the catalyst of the present invention based on rL.

Arrow A Examples 2 to 7 Table 1 shows the results of reactions similar to those in Example 1 carried out in various water bath solutions by changing the crystallite diameter of the metal ruthenium of the hydrogenation catalyst, the zinc content and the gold ratio.

As described above, it can be seen that cycloolefins can be obtained with extremely high selectivity and yield.

Example 8 Example 1 except that 1N H, So, 1.6- was added.
The same operation was performed. The results are shown below.

5 minutes 18.2 85.1 15.51
5 minutes 41.8 82.0 34.560
Minutes 64.5 74.5 47.9 It can be seen that the warping speed can be increased to the philtrum by adding acid.

Claims (2)

[Claims] (1) When a monocyclic aromatic hydrocarbon is partially reduced with hydrogen in the presence of water, a reduced product of ruthenium containing zinc in advance is used as a hydrogenation catalyst, and the zinc content is 0.0% relative to ruthenium. A method for producing a cycloolefin, which comprises using a catalyst in an amount of 1 to 50% by weight, and carrying out the reaction under acidic conditions in the coexistence of at least one water-soluble zinc compound. (2) The method for producing a cycloolefin according to claim 1, wherein the hydrogenation catalyst has an average crystallite diameter of 200 Å or less.