JPS6363627A - Production of cycloolefin - Google Patents

Abstract

PURPOSE:To produce the titled compound in high yield and selectivity, by partially reducing a monocyclic aromatic hydrocarbon with hydrogen under specific condition in the presence of water using a specific hydrogenated catalyst particle in a system added with a specific metal oxide and containing a solid basic zinc sulfate. CONSTITUTION:A cycloolefin compound, especially cyclohexene compound useful as a raw material for polyamide, etc., is produced by reducing a monocyclic aromatic hydrocarbon with hydrogen in the presence of water. The above reaction is carried out under neutral or acidic condition in the presence of one or more solid basic zinc sulfate, using a hydrogenation catalyst particle having average crystal particle diameter of <=200Angstrom and composed mainly of metallic ruthenium and adding an oxide of one or more metals selected from Ti, Nb, Ta, Cr, Fe, Co, Al, Ga and Si separately from the above catalyst particle to the reaction system. The objective compound can be produced on an industrial scale at a low cost in outstandingly high selectivity and yield in a stabilized catalyst system.

Description

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

% of cyclohexene.

Cyclohexenes have high value as intermediate raw materials for organic materials and polyamide raw materials.

It is important as a raw material for lysine.

(Conventional technology) As a method for making blades of such cyclohexene.

For example, (1) a method using a catalyst composition containing water, an alkaline agent, and an element of Group VI of the periodic table (Japanese Patent Publication No. 56-2
2850), +21 nickel, cobalt.

Chromium, titanium, fc uses ruthenium catalyst supported on zirconium oxide, alcohol or ester is used as an additive (Publication No. 52-5935), F31 steel, silver, cobalt, and potassium. A method using a ruthenium catalyst containing water and a phosphate compound (Japanese Patent Publication No. 1a of Japanese Patent Publication No. 56-4536 1a),
+41 Ruthenium catalyst as well as metals of group IAA of the periodic table [group A metals, carbon dioxide and manganese.

A neutral i-ratio containing a salt of at least one cation selected from a method of carrying out a reaction in the presence of an acidic aqueous solution (% Publication No. 57-7607), (5) at least 1 mK main components of ruthenium and rhodium The solid catalyst is a group I A metal of the periodic table, [a group A metal.

Pre-treated with an aqueous solution containing a salt of at least one cation selected from the group consisting of manganese, iron, iron and zinc.
A method of performing anti-21 in the presence of water using a
1-98243), [6] A method of carrying out a reaction using a ruthenium catalyst and adding at least one of zinc oxide and water-fired zinc to the reaction system as an active component (JP-A-1) 1359-184138 (7) In the presence of water and at least 1a of zinc f-hide,
Average below A.

A method using metallic ruthenium crystallites and/or aggregated particles thereof having a crystallite diameter (% opening 41-509
Publication No. 30), etc. have been proposed.

(Problem to be solved by the invention) However, in these conventionally known methods.

To enhance the selection of the desired cyclohexene,
Currently, the yield and trap productivity of cyclohexene are low, such as the need to significantly suppress the conversion rate of the raw material and the very low conversion rate of cyclohexene, making it not a practical method for producing cyclohexene. be.

However, in order for this method of producing cyclohexene to become practical, it is necessary and important that the catalyst used in one reaction be capable of continuously maintaining stable activity or selectivity. .

Conventional techniques are not necessarily sufficient in this respect.

Also, according to the study by the present inventors, 1 For example, *Opening 61
In some cases, cycloolefins can be obtained in relatively high yields when gold or metal ruthenium particles are used alone as a catalyst, as proposed in Publication No. 50930. It has been found that there are many cases in which it is difficult to maintain a stable reaction system, such as when the catalyst adheres to, accumulates on, etc., and the catalyst itself becomes deformed.

(Ninth Means for Solving the Problems) The present inventors have determined to solve the problems, improve the yield of cyclohexanes, and obtain a stable friendly catalyst system that is industrially advantageous. The present invention was achieved through intensive study of the catalyst system in the partial reduction method of arsenic group carbon (arsenic hydrogen), that is, the system consisting of the main catalyst and other components.

In other words, the present invention uses hydrogenation catalyst particles containing metal ruthenium as a main component and having an average crystallite diameter of 200^ or less when partially reducing monocyclic aromatic hydrocarbons (in the presence of water and under hydrogen pressure). , the catalyst particles are titanium, niobium, tantalum, and chromium.

An oxide of at least one metal selected from iron, cobalt, aluminum, gallium, and silicon is added, and the mixture is reacted under neutral or acidic conditions in the coexistence of at least one solid basic zinc sulfate. By carrying out step 13, it is a method for producing cycloolefins in which cycloolefins can be obtained in unprecedentedly good yields, and which is also surprisingly stable and can be used as a catalyst system. According to the method of the present invention, it is possible to increase the concentration of cycloolefins to 40 or more, and at the same time, it is possible to achieve a concentration of cycloolefins of 40 or more, and at the same time, it is possible to achieve a concentration of cycloolefins of 40 or more, and at the same time, it is only possible to achieve a concentration of 0.

Various changes in the hydrogenation catalyst 1 For example, the progress of agglomeration over time, changes in the average crystallite diameter, etc.Changes in the reaction process can be completely suppressed, and from a practical perspective, it is extremely useful. It's a method.

Eight specific embodiments of the present invention will be explained below.

What is the monocyclic aromatic 5-hydrocarbon that is the raw material of the present invention?

Benzene, toluene, xylene a, Jli[lower alkylbenzenes having an alkyl group of 4 or less.

In the present invention, hydrogenation catalyst particles containing metallic ruthenium as a main fraction having an average crystallite diameter of 2oo'A or less are used. This catalyst is obtained by reducing a ruthenium compound in the form of a ruthenium compound, which may be mixed with other metals, for example in a step behind it or after its preparation.

Zinc or chromium, molybdenum, tungsten.

Its main components are ruthenium with manganese, cobalt, nickel, iron, and M. There are no particular restrictions on the ruthenium compounds.

For example, chlorides, bromides, iodides, nitrates, sulfates,
Hydroxide, oxide, ruthenium red, or various complexes containing ruthenium can be used. Reduction methods include reduction by hydrogen gas pressure, formalin, and sodium borohydride.

This can be carried out by a chemical reduction method using hydrazine or the like. In particular, ruthenium salts are hydrolyzed to form hydroxides,
A method of reducing this is preferably used.

In addition, in the method of the present invention, if a reduced product of a ruthenium compound containing all zinc in advance is used, the yield of cycloolefin can be further increased and the product can be used effectively. Such a catalyst.

A zinc compound is added to a valuable ruthenium compound in advance, and then the reduced product obtained by reduction is used.Ruthenium is reduced to a golden state and has a weight of 7 tons. Valuable ruthenium compounds that can be used include chlorides, nitrates,
Salts such as sulfates, complexes such as ammine complexes, hydroxides,
Among these oxides, trivalent or tetravalent ruthenium f-hybrid compounds are particularly preferred because they are readily available and easy to prepare and handle. In addition, the zinc compounds that can be used are
A wide range of substances can be used, including salts such as chlorides, nitrates, and sulfates, complexes such as ammine complexes, hydroxides, and oxides.

The zinc content in such catalysts is 0.1 to ruthenium.
~50 weight range, preferably 2-20 weight whisper iC adjusted. Therefore, the main components of the catalyst are.

Ruthenium is used as a carrier, and zinc is not a carrier.

Valuable ruthenium compounds containing such zinc are
It may be obtained as a solid by a general coprecipitation method using a mixed bath of zinc and ruthenium compounds, or it may be obtained as a homogeneous solution.

As a method for reducing such a valuable ruthenium compound containing zinc, a general method for reducing ruthenium can be applied6.For example, a method of reducing with hydrogen in a gas phase, a method of reducing with hydrogen or an appropriate chemical in a liquid phase, etc. A method in which a reducing agent such as NaB)I4 or formalin is used for reduction is preferably applied, and a method in which hydrogen is used for reduction in the gas or liquid phase is particularly preferred.

When reducing with hydrogen in the gas phase, avoid extremely high temperatures to avoid increasing the crystallite size.

Alternatively, it may be a good idea to dilute hydrogen with another inert gas. When the reduction is carried out in a liquid phase, a solid valuable ruthenium compound containing zinc may be dispersed in water or alcohol, or it may be carried out in the form of a homogeneous solution. At this time, the ninth point is to make sure that the reduction progresses well.

It is advisable to carry out appropriate heating such as stirring for 1 Mi. Alternatively, use an alkaline aqueous solution or an appropriate metal salt aqueous solution instead of water.

For example, an aqueous alkali metal salt solution or the like may be used.

The above hydrogenation catalyst particles are crystallites mainly composed of ruthenium, and /''1fc is aggregated and exists in the reaction system as nine particles, but the selectivity and yield of cycloolefins,
Furthermore, in order to increase the reaction rate, the average crystallite diameter of the crystallites needs to be 200X or less, and 150X or less.
It is preferably less than or equal to X, and more preferably less than or equal to 1ooX. Here, the average crystallite diameter can be calculated by a general method, that is, from the spread of the diffraction line width obtained by the X-ray diffraction method, using the formula of 5cherrer. Specifically, when a CuKcz ray is used as an X-ray source, the spread of a diffraction peak having a maximum around 4411 at one diffraction angle (2θ) is calculated from .

In the present invention, the hydrogenation catalyst particles as mentioned above are titanium, niobium, mental, and chromium.

Warping is performed by adding an oxide of at least one metal selected from iron, cobalt, aluminum, gallium, and silicon.

The amount of oxide that can be added is t relative to the water coexisting in one reaction system.
x t o'-s ~o, s weight times, good IL, <Fi
IX1〇-yi ~ 0.1 times the weight.

The oxide to be added is preferably in the form of fine powder,
The average particle diameter is preferably from o, o o s to 100 μ, more preferably from 0.005 to 10 μ. The average particle size is determined by using ethanol as a total dispersion medium, adding an oxide with a weight of less than 1% to the dispersion medium, and performing a dispersion operation for 30 to 60 minutes in an ultrasonic oscillator of several hundred watts. Sedimentation method (natural sedimentation method, centrifugal sedimentation method)
It is calculated as follows to measure the change in absorbance of the dispersion.

The effects obtained by adding such oxides are very useful, and one is that cycloole 7-(
It is possible to improve the selection rate and convergence of
The goal is to maintain a stable reaction system by suppressing fluctuations in the reaction system due to adhesion of the hydrogenation catalyst to the surface of the container or agglomeration of the hydrogenation catalyst, and to maintain a stable reaction system over a long period of time. It is highly effective in producing cycloolefins.

It also makes it easier to handle slurries containing 7X catalysts, for example, hydrogenation catalysts.

It also has the effect of diluting and increasing the amount, making catalyst preparation and recovery easier.

On the other hand, what should be noted in BA is that when a ruthenium-supported catalyst prepared by supporting ruthenium on such a modified product by a normal method such as a dipping method, drying method, or precipitation method and reducing it is used as a hydrogenation catalyst. , the selectivity of cycloolefins is
The addition of a dispersant in the method of the present invention, which is extremely low compared to the method of the present invention, is essentially different from that of supported ruthenium catalysts.

In the present invention, at least one solid basic zinc sulfate coating system is further used. Here, solid basic zinc sulfate refers to ZnSO4-mZno-nH,0 or Zn5O, mZn(OR), (where m and n are numbers such that 0.5≦m≦49 and o≦n≦8, respectively. )
.

Additionally, K is Zn(z+1)(OH)*t-so, (C
? Knee T: , L represents the JI number of 1≦t≦4)
A compound that can be represented by a general formula such as znso4.ZnQ.

ZnSO4@ZnO・HtO (ZnSO4・Zn(O
H)t t 7t is Zfl*(OH)1804).

Zn5O, -3ZnO, ZnSO4.5ZnO-AH,
O(ZnSO, 5Zn(OH)1).

Zn5O, -3ZnO-6H,O, ZnSO4-5Zn
O-7H10, ZnSO4・5Zn0・8 HlO-Z
nSO4@4 Zn0 ・4 H* O(ZnSO4
@4 Zn (OH%) is a group of compounds that are often found in published works (for example, Inorganic Chemistry Zensho, ■-1゜500 pages, Maruzen).

These basic zinc sulfates have been known for a long time).

It can be obtained by various methods, but generally it can be obtained by using an aqueous solution of zinc sulfate as a mother liquor and reacting it with an appropriate alkali, or by heating it. Also,
It can also be obtained as a mixture of various basic zinc sulfates by adding arsenic hydroxide to an aqueous sulfuric acid solution or an aqueous zinc sulfate solution and heating the mixture.

K in which these solid basic zinc sulfates coexist in the reaction system is
It is preferable to mix one or a mixture of these with a hydrogenation catalyst or oxide in powder form and add it to the reaction system or separately, or use an aqueous zinc sulfate solution for warping as described below. In the case, Fi, a part or all of which is converted into solid basic zinc sulfate in the reaction system, f
Hydrate 1 For example, zinc hydroxide or zinc oxide may be added to the reaction system.

Generally, the solubility of basic zinc sulfate in water is low;
It can coexist as a solid in systems that warp with the addition of a small amount. 91. When the hydrogenation catalyst of the present invention is used, due to the adsorption power of the hydrogenation catalyst, even if the amount added is less than the solubility of basic zinc sulfate in the reaction system, # It can coexist as a solid on top of acid.

In the present invention, such solid basic zinc sulfate is added to the hydrogenation catalyst and the total amount of metal orgr to be added.
IX10-' to 1x2 as zinc, preferably IX
10-'' to 0.5 times by weight are co-existed and anti-+6 is carried out.

If the coexisting amount is too small, the effect on improving the cycloolefin selector and yield will be weak, and if it is too large, the reaction rate will decrease, and as a result, a large amount of hydrogenation catalyst will be required. It is difficult to find a warping system that is advantageous.

In this way, by coexisting solid basic zinc sulfate, the selectivity and yield of cycloolefins can be increased. Moreover, it has an equally high selectivity.

The range of reactions that can maintain high yield has been expanded, and cycloolefins can be obtained in good yield even at relatively low temperatures, increasing the degree of freedom in selecting reaction conditions, making it extremely valuable industrially. Become.

It is not necessarily clear why the coexistence of basic zinc sulfate improves the selectivity and collection of cycloolefins, but the coexisting insoluble basic zinc sulfate is adsorbed onto the hydrogenation catalyst, It is thought that this provides an advantageous habitat for insect removal of cycloolefins.

In the present invention, the addition of an arsenic acid and the coexistence of a solid basic zinc exhibit a surprising effect on the stability of the catalyst as described below.

At the same time, the use of fine metal catalysts is different from catalysts in which the metal is supported on a carrier. 91 In the reaction system, secondary aggregation, sintering, etc. often proceed, and the sustainability of the catalyst system as a stable one. Who has the points? This also applies to the metal ruthenium catalyst used in the method of the present invention, and in the following cases where practicality is concerned, it is an absolutely necessary technology to avoid the progression of secondary agglomeration and sintering. .

It is clear that the coexistence of solid basic zinc sulfate in the present invention has the effect of suppressing changes in the catalyst such as secondary agglomeration and sintering, in addition to the presence of 2 g of solid basic zinc sulfate. titanium, niobium, tantalum.

Chromium, iron, cobalt, aluminum, potassium.

The addition of oxides of at least 181 selected metals to silicon also has similar effects, and the combined use of these oxides and solid basic zinc has a synergistic effect.

Catalysts and reaction systems can be made extremely stable.

In the absence of isobasic zinc sulfate and oxides.

When the hydrogenation catalyst used in the present invention is maintained under reaction conditions, secondary aggregation of the catalyst progresses in an awn-like manner.

In this way, the catalyst has undergone secondary aggregation.

The dispersibility of catalyst particles in the aqueous phase becomes significantly poor.

In aggregates in such a state, a sufficient amount of hydrogen and benzene must be applied on the catalyst to diffuse and diffuse hydrogen and benzene into the metal ruthenium in the aggregate, especially for the 1 reaction in which diffusion of hydrogen is difficult. Unable to supply, the state of the reaction satisfies! I can't get l. In particular, if the supply of hydrogen to the catalyst is insufficient, the reduction in 1 reactor degree and the increase in the number of thin strips 6 become significant. First, the cycloolefin will not diffuse out of the reaction field or out of the pre-agglomerated body, and the hydrogenation reaction will proceed further, resulting in the formation of cycloalkane. Increased side reactions. Such changes in the state of aggregation can also be directly observed using an electron microscope.

Similarly, the hydrogen catalyst used in the present invention is completely solid basic in the absence of zinc sulfate and oxides.

It has been found that the average crystallite size of ruthenium metal determined by X-ray diffraction increases when the reaction conditions are maintained for a long time. In particular, the reaction rate decreases over time, making it difficult to control a stable reaction over a long period of time.

This tendency increases when the hydrogenation catalyst concentration and reaction temperature are increased.
Furthermore, as stated in similar works, for example, when attempting to perform a single reaction by increasing the productivity of cycloolefin per reactor volume, this means that it becomes more difficult to maintain the stability of the reaction. However, this is not practical.

It is clear that it is desirable that such changes in the catalyst be as small as possible. Only by the combination of the oxide and basic zinc sulfate used in the present invention can the average crystallite size of ruthenium metal as described above be reduced. It is clear that a situation can be obtained in which the increase over time can be virtually ignored.9.

The reason for the stabilization of the reaction system according to the present invention is not necessarily certain, but solid basic zinc sulfate is present on the surface of the hydrogenation catalyst or the like. It is thought that the surface properties are changed. The coexistence of oxides greatly suppresses collisions between hydrogenation catalysts, further suppressing the secondary effects of catalysts that are the primary cause of decreasing surface area and increasing crystallite diameter. considered to be a thing.

As described above, the extremely stable reaction system that is first linked by a combination such as the method of the present invention can be said to be extremely valuable from a practical and industrial standpoint.

The present invention requires the presence of water. The amount of water varies depending on the reaction format, but it can be allowed to coexist at 0.01 to 100 times the weight of hydrogen in a single aromatic hydrocarbon, which is generally used. The organic liquid phase as the main component and the liquid phase containing water are two
It is necessary to form a phase, and the coexistence of an extremely small amount of water that forms a homogeneous phase under the reaction conditions (1), or the coexistence of an extremely large amount of water, will reduce the effect; If it is too large, it will be necessary to enlarge the reactor, so it is practically desirable to coexist with 5 to 20 times as much FiO.

Furthermore, in the present invention, by using an aqueous solution of a metal salt in place of water as in a conventionally known method, it is possible to obtain a preferable combination of selected cycloolefins. can. Metal salts include Group IA metals of the periodic table, I
Nitrates, chlorides, sulfates, acetates, phosphates, etc. of group IA metals, group B metals, manganese (e.g., Japanese Patent Publication No. 7607/1983), cobalt, etc. are used;
Salts of Group A metals, [Group A metals and zinc are preferred, and more preferably salts such as strong salts such as sulfates are preferred.

Furthermore, the present invention includes s? Favorable results can be obtained by using an aqueous solution of a strong acid salt of zinc, especially zinc sulfate, as the water solution. When basic zinc sulfate coexists in a zinc sulfate aqueous solution, solubility equilibrium is established between ions and compounds, and even though the zinc sulfate aqueous solution is acidic, only a very small amount of basic zinc sulfate dissolves in the aqueous solution. Basic zinc sulfate can be stably maintained in the system in an insoluble state. - To give an example, 1. For example, in a solution of 100% zinc sulfate (pH about 5) at room temperature, ZnSO4 + 5Zn (OH
)t k When the water is heated to 710 or more, the pH of the liquid becomes stable at around 5.7 to 5.8, and znsO4.3Zn(O
H) t can remain insoluble in water. Mayu, basic zinc sulfate in zinc sulfate aqueous solution? Having them coexist also has the effect of bringing the pH of the water core liquid closer to neutrality, as in the above example.

It is thought that it has a considerable effect on corrosion of metal materials of equipment, which occurs due to the acidity of the zinc sulfate aqueous solution.

Such an aqueous zinc sulfate solution can be used at a concentration from 0.01% by weight to saturated dissolution, but preferably #'i
It is recommended to use 0.1 to 30 weights.

In the warping system of the present invention, insoluble basic zinc sulfate must be present in the warping solution. Therefore, it is preferable that one reaction system be carried out in a slightly alkaline to acidic state, although this varies depending on the amount of the insoluble basic zinc sulfate coexisting and the amount of the aqueous solution. More preferably, it is carried out in a neutral to acidic state.

The partial reduction reaction in the method of the present invention is usually carried out in a liquid phase M'f
In the 4th method, continuous friendship is done in batches.

0 reaction conditions that can also be carried out using a stationary phase method.

The hydrogen pressure is usually 1 to 200 kglctdG, although it is selected appropriately depending on the type of catalyst and additives used and the temperature.

Preferably in the range of 10 to 100 kglcriG.

The reaction temperature is room temperature to 250 G, preferably 100 to 20 G.
It is in the range of 0C. The reaction time is determined by determining the selection source of the desired cyclohexene and the actual target value of the yield.
It may be selected as appropriate, and although there is no particular restriction, it is usually several seconds to several hours.

(Effects of the Invention) According to the present invention, cycloolefins can be obtained in a highly selective manner that is not available conventionally.

It is a stable catalyst system and has extremely high industrial value.

(Example) Next, the present invention will be described in more detail with reference to Example 91, but the present invention is not limited to these Examples.

Examples 1 to 3 Ru(0H)s was reduced in water using pressurized hydrogen and exposed to metal ruthenium! t (average crystallite diameter 5o^) (
J, 5 f, Cruxs powder (average particle size 2,1 μ)
2.55'.

SO#! Basic zinc sulfate shown in Table 1 is used as zinc. 9゜2 and Zn5O, 7H, O 18% aqueous solution 280 d
K and F were placed in an autoclave with an internal volume of 1 ton made of tan,
After purging with hydrogen while stirring and raising the temperature to 150C, benzene 1
After the reaction, the hydrogen was heated at 150° C. for 60 minutes. After the reaction, it was rapidly cooled and the organic white layer was separated. The results of gas chromatography analysis are shown in Table 1.The by-product was cyclohexane.

Table 1 Examples 4 to 11 The reaction was carried out in the same manner as in Example 1 except that 2.52 mm of oxide powder having the average particle size shown in Table 2 was used in place of the Cr, O, and powders. The results are shown in Table 2.

Table 2 Moreover, in Examples 1 to 11, after the completion of the reaction.

When I opened the 6 vessels and observed them, I found that the catalyst and baride powder were well dispersed in all cases, and no results were observed, and there was almost no adhesion of the catalyst to the titanium wall.

Comparative Example 1 The same operation as in Example 1 was carried out except that CrtO, powder 2 and basic zinc sulfate were not used, and the reaction was carried out for 30 minutes. Halo for benzene conversion 7. o%, the selective layer of cyclohexene was 52.9%, cyclohexene yield, IC
Atsutomo at 35.4%.

After the first reaction was completed, the first reactor was opened and folded.
Agglomeration of catalyst was observed, and catalyst adhesion occurred on the titanium wall.

Comparative Example 2 The same operation as in Example 1 was carried out except that Cr, O, and powder were not used, and anti-C' was carried out for 60 minutes. The conversion rate of benzene is 56.4%, and the selective layer of cyclohexene is 7
It was 3.2%, and cyclohexene was 41.3%.

Kakuku 1st ``After 6th, I opened the 1st 5th vessel and performed a ritual ceremony, and found that there was almost no agglomeration of the catalyst, and it was still solid.

Adhesion of catalyst was observed on the titanium wall surface.

Comparative Examples 3 to 8 A hydrogenation catalyst in which one weight of ruthenium prepared by adsorbing a salt [hirthenium] on an oxide through normal impregnation and carrying out hydrogen reduction was carried out.5. Use Of.

The same procedure as in Example 1 was carried out except that Cr and 0st were not added, and the reaction during 607) was exhausted. The results are shown in Table 3.

Table 3 It is clear that the system in which oxides are added in the present invention is completely different from the conventional supported catalyst system.

Example 12 Reduced product of ruthenium containing zinc in advance as a catalyst (zinc content 7 o weights, average crystallite diameter a
X) Using o, sy, the same operation as in Example 1 was carried out, and the mixture was allowed to warp for 60 minutes. Conversion of benzene”IA
Fi68.9%, 4 choices of cyclohexene! u80,4
%, cyclohexene yield was 55.4%.

Example 13 ZnSO4・Zn (OH)t't''-1 as zinc
The same procedure as in Example 3 was carried out by Rin et al. using 00η and using water as a 18% water bath solution of Zn5O,.7H,0.

Let it react for 90 minutes. The benzene conversion rate was 50.8%, the cyclohexene selectivity was 63.5%, and the cyclohexene yield was 32.3%.

In addition, after the warping was completed in Example 13, the slurry was filtered and recovered, concentrated hydrochloric acid was added to dissolve the zinc compound present on the catalyst and Crt, and the zinc and sulfur in this solution were removed. It was determined by plasma emission spectrometry analysis,
Zinc is 95! I am n9 and Ioh is 18 da and my friend. This clearly shows the coexistence of solid basic zinc sulfate.

Comparative Example 9 Example 1 except that the amount of catalyst used was a, o sy, and Cr, O, powder, and basic zinc sulfate were not used.
The same operation as in 5 was performed, and the reaction was allowed to proceed for 30 minutes.

The conversion rate of benzene was 66.1%, cyclohexene selectivity was 2.3%, and cyclohexene convergence was 1.5%.

Example 14 Same catalyst as Example 1 (average crystallite diameter 5oλ) 1.5? ,
Oxide powder (average particle size 0.55μ) 7.5P.

Zn5O, -SZn (OH)1 f0.6 as zinc
f, and Zn5O, 7H 1018% aqueous solution 151d
i, inner surface VCf7 o 7': Y-ting and then charged into an autoclave with an internal volume of 400 cm, a total pressure of 50 kg/cdG with hydrogen, and kept at 160 Ci' for 200 hours while stirring at high speed. Collect slurry,
After washing, the average crystallite diameter of the catalytic metal ruthenium was measured by X-ray diffraction, and it was 55A or less in all cases using any oxide, showing almost no change.

Next, as an oxide, Cr! When a reaction was carried out by adding os and using Y3, a recovered slurry, and adjusting the liquid composition such as additives to the same conditions as in Example 1, there was almost no change in reaction rate or selectivity. Next.

Comparative Example 10 Oxide powder and ZnS 04.4Zn toH)
When the same operation as in Example 14 was carried out except that KLL was not used, the average crystallite diameter of the recovered catalytic metal ruthenium greatly increased to 78A, and the change in the catalyst over time was clear. Ta.

However, when the reaction was carried out using the tail of the recovered material and adjusting the liquid composition such as additives so that the conditions were the same as in Example 1, the reaction rate decreased to about H.

Comparative Example 11 All the same operations as in Example 14 were carried out without using oxide powder, and the average crystallite diameter of the recovered catalyst metal ruthenium was 61A. When the reaction was carried out by adjusting the liquid composition such as additives so that the conditions were the same as in Example 1, the reaction rate was about 374.
It declined to .

It is clear from Example 14 and Comparative Examples 10.11 that the catalyst system in the method of the invention is extremely stable.

Claims (7)

[Claims] (1) When partially reducing monocyclic aromatic hydrocarbons with hydrogen in the coexistence of water, hydrogenation catalyst particles containing metal ruthenium as a main component and having an average crystallite diameter of 200A or less are used. Separately, an oxide of at least one metal selected from titanium, niobium, tantalum, chromium, iron, cobalt, aluminum, gallium, and silicon is added,
Furthermore, a method for producing a cycloolefin, characterized in that the reaction is carried out under neutral or acidic conditions in the coexistence of at least one solid basic zinc sulfate. (2) The method for producing a cycloolefin according to claim 1, wherein the hydrogenation catalyst is a reduced product of ruthenium containing zinc in advance. (3) The method for producing a cycloolefin according to claim 2, wherein the zinc content in the hydrogenation catalyst is 0.1 to 50% by weight based on ruthenium, which is the main component. (4) The amount of oxide added is 1 x 10^-^3 relative to water
The method for producing a cycloolefin according to claim 1, wherein the amount is 0.3 times by weight. (5) The average particle diameter of the oxide to be added is 0.005 to 10
The method for producing a cycloolefin according to claim 1, wherein the cycloolefin has a particle diameter of 0μ. (6) The method for producing a cycloolefin according to claim 1, wherein the amount of coexisting solid basic zinc sulfate is 1×10^-^4 to 1 times the weight of zinc relative to the hydrogenation catalyst. (7) A method for producing a cycloolefin according to claim 1, wherein the reaction is carried out in the presence of an aqueous zinc sulfate solution.