JPH06247881A - Partial hydrogenation of monocyclic aromatic hydrocarbon - Google Patents

Abstract

PURPOSE:To provide a process for the partial hydrogenation of a monocyclic aromatic hydrocarbon, capable of stably keeping the reaction yield of cycloolefin over a long period and facilitating the separation of water. CONSTITUTION:A monocyclic aromatic hydrocarbon is partially hydrogenated to produce a cycloolefin by reacting a monocyclic aromatic hydrocarbon with hydrogen in the presence of a fine particulate hydrogenation catalyst composed mainly of metallic ruthenium. The reaction is carried out by using a reactional system composed of a continuous aqueous phase containing suspended fine particulate hydrogenation catalyst, an oil phase containing the monocyclic aromatic hydrocarbon and a gaseous phase containing hydrogen and applying a shearing force to the reactional system at the maximum shearing rate of 50-2,000/sec, thereby dispersing the oil phase and the gaseous phase into the continuous aqueous phase in the form of oil droplets and gas bubbles, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a partial hydrogenation process for producing a cyclic olefin by partially hydrogenating a monocyclic aromatic hydrocarbon. More specifically, the present invention relates to a monocyclic aromatic hydrocarbon moiety for producing a cyclic olefin by reacting a monocyclic aromatic hydrocarbon with hydrogen in the presence of a particulate hydrogenation catalyst containing ruthenium as a main component. Regarding a hydrogenation method, a reaction system comprising a continuous aqueous phase in which a particulate hydrogenation catalyst is suspended, an oil phase containing a monocyclic aromatic hydrocarbon and a gas phase containing hydrogen is used, and a specific maximum shear rate is used. The reaction is performed by applying a shearing force to the reaction system so as to disperse the oil phase and the gas phase in the continuous aqueous phase as oil droplets and bubbles, respectively. By the method of the present invention, not only is cyclic olefin obtained with high selectivity and high yield, but also a high level of catalytic activity can be retained for a long period of time during the reaction. Cyclic olefins are highly valuable as intermediate raw materials for organic chemical industrial products, and are particularly important as polyamide raw materials and lysine raw materials.

[0002]

2. Description of the Related Art Conventionally, as a method for partially hydrogenating a monocyclic aromatic hydrocarbon to produce a cyclic olefin, a method using a particulate hydrogenation catalyst mainly composed of ruthenium metal and water (Japanese Patent Laid-Open No. 61-50930). JP-A-62-455
44, JP 62-81332, JP 6
2-205037 and JP-A-63-17834) have been proposed.

According to Japanese Patent Laid-Open No. 63-17834, an example is used in which ruthenium metal atomized to 200 angstroms or less is used as a catalyst, and a zinc compound is used as a cocatalyst and zirconium oxide or hafnium oxide is added. Have been described. According to it, water, a catalyst and benzene are charged into an autoclave with a stirrer to prepare an acidic aqueous solution using a normal acid, and the reaction temperature is 25 to 250 ° C.
In this case, hydrogen is supplied at a reaction hydrogen partial pressure of 5 to 150 kg / cm ² for a reaction time of several minutes to 2 hours to cause a reaction, and cyclohexene is obtained from the oil phase.

[0004]

The reaction system used in the above-mentioned conventional method exists in a suspended state in an oil phase containing mainly monocyclic aromatic hydrocarbons, an aqueous phase containing mainly water, and an aqueous phase. It is a heterogeneous system consisting of four phases such as the solid phase of the catalyst and the gas phase of hydrogen gas blown into the mixture. In such a reaction system, when the mixing of oil and water and / or the mixing of gas and liquid is insufficient, there is a phenomenon that the reaction yield is remarkably reduced and the original performance of the catalyst cannot be sufficiently exhibited. Further, if the mixture of gas and liquid is too strong in the reaction system, the decrease in catalyst activity with time may be significantly accelerated. Moreover, after the reaction, the reaction product is allowed to stand and oil-water separation is carried out, and the cyclic olefin is obtained from the oil phase, but if the mixing is too strong, the oil-water separation time will become significantly longer, and an excessive standing area will be required. Will be.
As described above, in the conventionally known method, the reaction yield of the monocyclic aromatic hydrocarbon to the cyclic olefin is not sufficiently stable, and a practical monocyclic aromatic hydrocarbon part is obtained. It was not a hydrogenation method.

[0005]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the inventors of the present invention have conducted extensive studies and as a result, have rigorously controlled the contact states of the continuous aqueous phase, oil phase and gas phase of this reaction system. Surprisingly, it was found that the above problems can be overcome. More specifically, the present inventors apply a shearing force to the reaction system so as to obtain a specific maximum shear rate, and disperse the above-mentioned oil phase and gas phase in the continuous water phase as oil droplets and bubbles, respectively. It has been found that the above-mentioned problems of the prior art can be overcome by carrying out the reaction by means of the reaction. The present invention has been completed based on the above findings.

[0006] That is, the present invention can advantageously produce a cyclic olefin on an industrial scale, not only minimizes the decrease in the activity of the hydrogenation catalyst during the reaction, but also provides a high selectivity and a high yield of the cyclic olefin. An object of the present invention is to provide a method for partial hydrogenation of monocyclic aromatic hydrocarbons, which can be maintained for a long period of time and the oil-water separation time after the reaction can be easily shortened. The above and other objects, features and benefits of the present invention will be apparent from the following detailed description and the appended claims, which will be described with reference to the accompanying drawings.

According to the present invention, a portion of a monocyclic aromatic hydrocarbon for producing a cyclic olefin by reacting a monocyclic aromatic hydrocarbon with hydrogen in the presence of a particulate hydrogenation catalyst containing metal ruthenium as a main component. In the hydrogenation method, a reaction system comprising a continuous aqueous phase in which a particulate hydrogenation catalyst is suspended, an oil phase containing a monocyclic aromatic hydrocarbon and a gas phase containing hydrogen is used, and a maximum shear rate is 50 to 2000. A single ring characterized in that a shearing force is applied to the reaction system so that the above reaction is carried out by dispersing the oil phase and the gas phase in the continuous aqueous phase as oil droplets and bubbles, respectively. A method for partially hydrogenating aromatic hydrocarbons is provided.

In the process of the present invention, the reaction between a monocyclic aromatic hydrocarbon as an oil phase and hydrogen as a gas phase is carried out in a continuous aqueous phase containing water and a particulate hydrogenation catalyst suspended therein. To do. The hydrogenation catalyst is mainly composed of metal ruthenium particles, but may further contain a zinc compound, and may optionally contain other metal compounds.

Hereinafter, the gas phase as referred to herein is mainly composed of hydrogen gas, and other vapors such as monocyclic aromatic hydrocarbons, cyclic olefins, naphthenes and water, and impurities coexisting in the raw material hydrogen gas, for example, It is composed of methane and ethane. The oil phase is composed mainly of monocyclic aromatic hydrocarbons, cyclic olefins and naphthenes, and is composed of dissolved water and hydrogen. The aqueous phase is mainly composed of water and zinc compounds, monocyclic aromatic hydrocarbons, cyclic olefins, naphthenes and hydrogen dissolved therein. The solid phase is composed of the ruthenium catalyst and a dispersant (for example, hafnium oxide or zirconium oxide) and is suspended in the aqueous phase.

First, the mechanism of this reaction will be explained by taking an example of using benzene as the monocyclic aromatic hydrocarbon. In the reaction system used in the method of the present invention, hydrogen in the gas phase is in contact with the water phase. It diffuses and dissolves in the water phase through the gas-liquid interface. Of course, hydrogen also dissolves in the oil phase, and some of them dissolve in the water phase through the oil phase. The dissolved hydrogen reaches the catalyst and is adsorbed on many active sites. On the other hand, benzene also diffuses and dissolves in the water phase through the oil-water interface in contact with the water phase. The dissolved benzene reaches the catalyst, is adsorbed, and reacts with hydrogen at the active site to generate cyclohexane. This cyclohexene leaves the catalyst and diffuses and dissolves in the aqueous phase. The cyclohexene in this aqueous phase moves to the oil phase through the interface in contact with the oil phase. Cyclohexene is obtained from this oil phase. Thus, the reaction system includes a mass transfer process. By the way, this reaction is a parallel sequential reaction, and there is a route where benzene is partially hydrogenated to cyclohexene and further hydrogenated to stable cyclohexane, and at the same time, benzene is directly transformed to cyclohexane. The former route is the main route. Since cyclohexene, which is the object of the present invention, is an intermediate product of a sequential reaction, it is necessary to increase the reaction rate of benzene to cyclohexene and suppress the reaction of cyclohexene to cyclohexane. Therefore, it is necessary to increase the concentration of benzene in the aqueous phase and quickly separate the produced cyclohexene from the catalyst to avoid re-adsorption. Therefore, the existence of an oil phase that extracts cyclohexene from the aqueous phase is essential. For example, when a small amount of benzene is dissolved in a catalyst system containing water in the absence of an oil phase and hydrogenated, the amount of cyclohexene produced is very small. This indicates that in a heterogeneous reaction, mass transfer processes such as diffusion of a reactant or product to the phase interface and diffusion through the phase interface are important for this reaction.

In these heterogeneous reaction systems, in order to speed up the mass transfer process so that the cyclohexene formation reaction on the catalyst is rate-determining, the interfacial area between gas, liquid, liquid and solid phase must be set. It is important to properly mix and disperse the four phases in order to increase the number. There are three mixing and dispersing functions, one is to finely disperse the bubbles to absorb hydrogen gas into the water phase, and the other is the substance of benzene and cyclohexene at the interface between the oil phase and the water phase in which the catalyst is present. Finely dispersing the droplets to increase the moving speed, and thirdly suspending and dispersing the aqueous phase catalyst. A particularly important mixing and dispersing function is to finely disperse air bubbles in the aqueous phase.

Regarding the reaction rate of the reaction using the method of the present invention and the selectivity of cyclohexene, the present inventors analyzed experimental data in an autoclave equipped with a stirrer and found that the hydrogen pressure was kept high and the mixing strength was increased. It was found that the reaction rate of benzene increases with increasing, but after reaching a certain level, the reaction rate decreases slightly. The phenomenon that the reaction rate becomes almost constant means that the reaction rate on the catalyst is rate-determining rather than the mass transfer rate. On the other hand, the selectivity of cyclohexene increases as the mixing strength increases, and tends to increase even when the reaction rate reaches the ceiling. The following reaction mechanism can be considered for the above phenomenon. When the hydrogen pressure is high and the mixing strength is high, the concentration of dissolved hydrogen in the aqueous solution is high. Along with this, the concentration of hydrogen adsorbed on the catalytic active site increases, the equilibrium adsorption amount of cyclohexene at the active site decreases, and the amount of cyclohexene that rapidly follows the aqueous solution and moves to the oil phase droplets increases. Estimated. That is, in order to increase the cyclohexene selectivity, the present inventors need to make the hydrogen gas in the reaction system into fine bubbles to sufficiently take the gas-liquid interface area and increase the concentration of dissolved hydrogen in the aqueous solution. I found a thing. For this purpose, not only simply injecting hydrogen gas into the reactor, but also by bubbling hydrogen gas into the reaction system, a sufficient dissolved hydrogen concentration in the aqueous phase can be obtained.

The hydrogen gas in the reaction system preferably has a large number of fine bubbles, and as the reaction progresses, the hydrogen gas in the bubbles dissolves in the aqueous phase, so that the bubbles become finer and eventually disappear. Or is discharged from the gas-liquid free surface above the reaction system. The bubble diameter is preferably as small as possible in terms of absorption of hydrogen gas, but the effect does not change even if it is made too small. On the other hand, it requires a large amount of energy to make it fine, and naturally there is a lower limit. The volume average cell diameter in the reaction system (hereinafter, simply referred to as cell diameter) is preferably 0.4 to 20 mm or less, and more preferably 0.5 to 10 mm or less. The average bubble diameter can be achieved simply by taking a photograph through a glass viewing window directly attached to the side wall of the reactor.

The amount of hydrogen gas blown into the reactor is such that the reaction equimolar or more necessary to maintain the required reaction pressure is supplied. Although the unreacted hydrogen gas is released from the upper gas-liquid free surface, it is desirable to absorb the unreacted hydrogen gas to the gas-liquid free surface as much as possible. The larger the number of hydrogen gas bubbles in the reaction system, the more effective the gas-liquid interface is, but the effect remains unchanged even if the number of bubbles exceeds a certain level. Ratio of hydrogen gas bubbles to reaction liquid (called gas hold-up)
Is preferably 0.002-0.2, and more preferably 0.004-0.15.

The distribution of bubbles in the reaction system is preferably uniform, but the bubbles may be dispersed to such an extent that the concentration of dissolved hydrogen in the aqueous phase does not become extremely uneven. Since the reaction system of the present invention is stirred, the concentration of dissolved hydrogen in the aqueous phase rarely becomes extremely non-uniform. By the way, as a result of investigating which of the oil phase and the water phase is the continuous phase, the reaction amount per catalyst aqueous solution is almost constant under a constant catalyst concentration in the aqueous solution. When the phase is a disperse phase, the reactor size can be made smaller than in the opposite case. The volume ratio of the oil phase to the water phase in the reaction system is preferably 0.01 to 1.5, more preferably 0.0 to 1.5.
2 to 1.0.

The oil-water interface can be said to be the same as the gas-liquid interface, and it is desirable to make the droplet size of the reaction system fine so that the oil-water interface area is sufficient and the benzene concentration in the aqueous solution is increased. The interfacial area required for mass transfer can be created by allowing many fine droplets of the oil phase to exist in the reaction system. Thus, the smaller the droplet diameter, the better, but if it is made too small, it takes a long time to coalesce the oil and water after the reaction, so that the stationary area or the required area of the oil / water separation tank is required. Will be too large. It is necessary to bring oil and water into contact with each other in an appropriately fine droplet state without forming such fine droplets. In order to secure a sufficient oil-water interface area and shorten the time required for oil-water separation, the volume average droplet diameter (hereinafter simply referred to as the average droplet diameter) is about 0.02 to about 30 mm. preferable. A more preferable average droplet diameter is about 0.05 to about 10 mm.

Here, the oil-water separation time in the stationary region or the oil-water separation tank can be measured as follows. A predetermined reaction system was placed in a 4 liter internal Teflon coating autoclave with a peephole, and after stirring and mixing, when the raw material supply and stirring were stopped, oil droplets increased in the aqueous phase and the reaction Upon reaching the upper part of the vessel, the oil droplets coalesce to form a continuous oil phase. The lower interface of this continuous oil phase descends until there is no dispersed droplet layer between the continuous oil phase and the continuous water phase, and finally stops as a bicontinuous oil / water phase interface. This period is called the oil-water separation time. Usually, the oil-water separation time for 4 liters is 8 to 60 seconds. The larger the reactor, the longer the rise time of the droplets and the longer the separation time.

Further, as a method for measuring the diameter of the liquid droplets dispersed in the aqueous phase, there are a light transmission method, a photography method and the like. However, since the reaction system includes an opaque slurry, the present inventors took a photograph. Adopted the law. As a sampling method of the mixed liquid from the reactor, a pressure slightly lower than that of the reactor (for example, 0.05
In a 1000 ml pressure-resistant transparent container adjusted to a pressure difference of 0.2 kg / cm ² ), 3% water containing 0.2% by weight of a surfactant was added.
About 50 ml of a slurry liquid containing oil phase droplets is sampled from a reactor in a stirring state through a sampling nozzle into a pressure resistant transparent container. The collected slurry is diluted with water in the container, and a photograph is taken of where the droplets floated on the upper layer. Enlarge the photo 2 to 100 times, measure the diameter of 150 to 350 droplets using a normal ruler,
The volume average droplet diameter was used. When the droplet diameter is large, the sampling device was enlarged to avoid coalescence of the droplets during sampling. Further, similarly to the measurement of the average bubble diameter, it can be achieved simply by taking a photograph through a glass viewing window directly attached to the reactor.

The liquid distribution state of the oil phase of the reaction system does not necessarily need to be uniform, like the bubble distribution state of hydrogen gas, and the concentration of dissolved monocyclic aromatic hydrocarbons in the water phase is extremely high. It suffices that the droplets are dispersed to the extent that they are not non-uniform. Since the reaction system of the present invention is in a fluidized state, the concentration of dissolved monocyclic aromatic hydrocarbons in the aqueous phase rarely becomes extremely non-uniform. Further, the bubbles of hydrogen gas and the liquid droplets of the oil phase in the reaction system are preferably present in the water continuous phase in which the metal ruthenium particles are suspended, and the dispersed state of the bubbles and the liquid droplets need not be uniform. As stated in each. By the way, as a method of dispersing hydrogen gas in the form of bubbles in the continuous phase of water and droplets of the oil phase, a fluid is caused to flow at high speed through a pipe, such as an agitator or the like, as will be described later, and shearing force is applied to the fluid. , There is a method of mechanically dispersing. In this case, in order to make fine droplets and bubbles, it is necessary to add an external force sufficient to overcome the interfacial pressure and viscous stress to the droplets and bubbles for a certain period of time or more, to break them up.
For this purpose, the shear rate applied to the fluid may be increased. The shear rate is a velocity gradient of a fluid, and for example, in a stirring reaction tank, it is a gradient of a velocity distribution of a discharge flow of a stirring blade. The measuring method of the shear rate is McGraw-H.
ill published by James Y. Oldshue. Ph. D. "FLUID MI
Use a hot-wire anemometer or laser anemometer as described in Chapter 2 of "XING TECHNOLOGY".

By the way, as to the fact that the shearing force applied to the reaction system is too large, the catalyst activity is remarkably decreased.
It is estimated as follows. The activity of a hydrogenation catalyst containing metal ruthenium crystallites and / or agglomerated particles present in the aqueous phase depends on the surface area of the crystallite,
There is a linear relationship with the reciprocal of the crystallite diameter for the same amount of catalyst. That is, when the ruthenium crystallite size is reduced, the catalytic activity is increased, and
It is believed that the number of sites on the crystallite surface suitable for the production of cyclohexenes is increased and the selectivity of cyclohexene is improved, as described in (1). However, although the metal ruthenium particles are used by being dispersed in an aqueous solution, it is conceivable that the crystallite diameter tends to increase due to agglomeration by applying external energy to the reaction system. For example, if the shearing force is strong, it is presumed that the metal ruthenium crystallite diameter increases with time, the activity decreases, and finally the selectivity of cyclohexenes also decreases. Even if a dispersant for dispersing the metal ruthenium fine particles is present, this phenomenon similarly occurs. In order to maintain a stable catalytic activity for a long period of time, it is preferable to apply a shearing force having an appropriate strength to the reaction system, and the strength can be expressed by the maximum shear rate. The maximum shear rate is preferably 50 to 2000 / sec (hereinafter, / sec is the reciprocal of seconds), and more preferably the maximum shear rate is 70 to 1500 / sec. Here, the maximum shear rate is, for example, the maximum gradient of the velocity distribution of the discharge flow by the stirring blade, without being restricted in the direction such as downward or sideways. Therefore, regarding the maximum shear rate, there is no particular limitation on the direction of the shear force. The higher the shear rate, the smaller the droplets and bubbles.

The particulate metal ruthenium, which is a hydrogenation catalyst, is suspended in the aqueous phase either alone or by using a dispersant such as hafnium oxide or zirconium oxide, but it is desirable to disperse it as uniformly as possible. Especially when the mixing strength of the reaction system is weak, the amount of hydrogen consumed in the aqueous phase portion increases and the hydrogen concentration in the aqueous phase portion decreases when the catalyst is precipitated and accumulated in a non-uniform distribution. The adsorbed hydrogen on the catalyst in that portion is reduced, which in turn lowers the selectivity of cyclohexene. When the amount of hydrogen adsorbed on the catalyst surface decreases, the area where hydrogen is not adsorbed on the catalyst increases, and the cyclohexene generated on the catalyst surface becomes difficult to release, so conversion of cyclohexene to cyclohexane is likely to occur. .

The monocyclic aromatic hydrocarbon as the raw material of the present invention refers to benzene, toluene, xylenes, and lower alkylbenzenes having an alkyl group having 4 or less carbon atoms. Further, as the raw material composition, those having high purity of monocyclic aromatic hydrocarbons are desirable, but hydrocarbon compounds as impurities, for example, naphthenes such as cyclohexane and cyclopentane,
It may contain paraffins such as pentane and hexane, olefins such as cyclohexene and methylcyclohexene, and may contain, for example, nitrogen and argon as inorganic substances. The composition of the hydrogen gas is preferably high in purity, but may contain a hydrocarbon compound or an inorganic substance similar to the impurities of monocyclic aromatic hydrocarbons.

In the present invention, hydrogenation catalyst particles containing metal ruthenium as a main component are used. The crystallite diameter of the metal ruthenium is preferably about 200 angstroms or less. This catalyst is obtained by reducing various ruthenium compounds, or other metal such as zinc or chromium after or during its preparation step.
The main component is ruthenium to which molybdenum, tungsten, manganese, cobalt, nickel, iron, copper and the like are added. Although various ruthenium compounds are not particularly limited, for example, chloride, bromide, iodide, nitrate,
Sulfates, hydroxides, oxides, ruthenium red, or various ruthenium-containing complexes can be used. As the reduction method, reduction with hydrogen gas or chemical reduction method with formalin, sodium borohydride, hydrazine, etc. can be used. Can be done by In particular, a method of hydrolyzing a ruthenium salt into a hydroxide and reducing the hydroxide is preferably used.

Further, in the method of the present invention, when a reduced product of ruthenium containing zinc in advance is used,
The yield of the cyclic olefin can be further increased and it is effectively used. Such a catalyst is a reduced product obtained by previously adding a valuable ruthenium compound with a zinc compound and then reducing it, and ruthenium is reduced to a metallic state. Valuable ruthenium compounds that can be used include, for example, salts such as chlorides, nitrates and sulfates, complexes such as ammine complex salts, hydroxides and oxides, but especially trivalent or tetravalent ruthenium compounds are available. It is preferable because it is easy and easy to handle. Further, a wide variety of zinc compounds such as chlorides, nitrates and sulfates, complexes such as ammine complex salts, hydroxides and oxides can be used for making the ruthenium catalyst. The zinc content in such a catalyst is adjusted to 0.1 to 50% by weight, preferably 2 to 20% by weight, based on ruthenium. Such valuable ruthenium compound containing zinc may be obtained as a solid by a general coprecipitation method using a mixed solution of a zinc compound and a compound of ruthenium, or may be obtained in a homogeneous solution state. Good.

As a method for reducing the valuable ruthenium compound containing zinc, a general method for reducing ruthenium can be applied. For example, a method of reducing with hydrogen in the gas phase, a method of reducing with hydrogen or a suitable chemical reducing agent such as NaBH ₄ or formalin in the liquid phase is preferably applied, and reduction with hydrogen in the gas phase or liquid phase is performed. The method is particularly preferred. When reducing with hydrogen in the gas phase, it is advisable to avoid extremely high temperature or to dilute hydrogen with other inert gas in order to avoid increasing the crystallite size. When the reduction is carried out in the liquid phase, the solid of the valuable ruthenium compound containing zinc may be dispersed in water or alcohols, or it may be carried out in the state of a homogeneous solution. At this time, stirring and / or heating may be appropriately performed in order to promote the reduction better. Instead of water, an aqueous alkali solution or an appropriate aqueous metal salt solution such as an aqueous alkali metal salt solution may be used.

The hydrogenation catalyst particles as described above are present in the reaction system as crystallites mainly composed of ruthenium and / or aggregated particles thereof, but the selectivity and yield of cyclic olefins, and further the reaction rate are increased. For this purpose, the average crystallite size of the crystallites is preferably about 200 angstroms or less, more preferably about 150 angstroms or less, and most preferably 100 angstroms or less. The finer the particle size is, the more effective it is, but the lower limit is defined by the term "crystallinity". Crystallinity means that atoms are regularly arranged periodically according to a certain symmetry, and a diffraction phenomenon by X-ray is recognized. Here, the average crystallite size is calculated by a general method, that is,
From the diffraction line width obtained by the X-ray diffraction method, Sherr
It is calculated by the formula of er. Specifically, C
When uKα ray is used as X-ray source, diffraction angle (2θ)
It is calculated from the spread of the diffraction line having a maximum at around 44 °.

In the present invention, the above-mentioned hydrogenation catalyst particles can be used alone, but can also be used by supporting them on a carrier such as silica alumina or titanium oxide. It is preferable to add at least one kind of zirconium oxide or hafnium oxide before the reaction, in addition to the above-mentioned hydrogenation catalyst particles. The amount of the oxide added is 1 × 10 ^{−3 to} 0.3 times by weight, and preferably 1 × 10 ^{−2 to} 0.1 times by weight, with respect to the water existing in the reaction system. The oxide to be added is preferably in the form of fine powder, and the average particle size thereof is more preferably 0.005 to 10 μm (described in JP-A-62-81332). Alcohol may also be used as an additive (JP-A-61-4).
4830). Further, in addition to the hydrogenation catalyst, oxides of aluminum, gallium, niobium, tantalum, chromium, iron, cobalt, titanium, or silicon (JP-A-62-62).
The reaction may be carried out by adding at least one selected from the group described in -201830). Further, in the hydrogenation catalyst slurry aqueous solution under the above conditions, in the presence of at least one water-soluble zinc compound (JP-A-62-45544) or in the presence of solid basic zinc sulfate and / or solid basic zinc sulfate salt, The reaction may be carried out under acidic or acidic conditions (JP-A-62,205037,
Methods described in JP-A-63-17834, JP-A-64-63627, JP-A-63-88139, and JP-A-63-152338).

When the amount of the catalyst in the aqueous phase of the reaction liquid is small, the reaction rate is slow and the reactor becomes large, and it is difficult to establish industrially. When the amount of the catalyst is large, the viscosity of the aqueous phase becomes too high and the fluidity is lost. The diffusion rate of dissolved hydrogen and monocyclic aromatic hydrocarbons is hindered and the reaction rate is reduced. Therefore, the weight ratio of the hydrogenation catalyst to water is preferably in the range of 0.001 to 0.2, more preferably about 0.002 to about 0.
It is 15. The reaction temperature is in the range of about 25 to about 250 ° C, preferably about 100 to about 200 ° C. The hydrogen partial pressure of hydrogen gas is in the range of about 5 to about 150 kg / cm ² , preferably about 10 to about 100 kg / cm ² . In the case of a stirred reaction tank, the reaction time is generally 5 minutes to 2 hours,
On the other hand, in the case of a pipe reactor, the reaction time is generally 1 minute to 20 minutes. The above time is defined as the "contact time" during which some monocyclic aromatic hydrocarbons are partially hydrogenated in contact with hydrogen gas and the catalyst. In the method of the present invention, the hydrogenation reaction is carried out using a neutral or acidic aqueous phase.
If the aqueous phase is alkaline, the reaction rate will decrease, which is not desirable. The pH value of the aqueous phase is generally in the range 0.5 to 7, preferably 0.5 to less than 7, more preferably 1 to 6.5.

Cyclohexene is isolated as follows. The reaction product of the partial hydrogenation reaction is an oily substance containing a cyclic olefin, naphthene, and a monocyclic aromatic hydrocarbon. For example, when benzene is used as the monocyclic aromatic hydrocarbon, the reaction products are target cyclohexene, by-product cyclohexane, and unreacted benzene. These boiling points are very close (cyclohexene boiling point = 83.0 ° C., cyclohexane boiling point =
80.8 ° C., benzene boiling point = 80.1 ° C.), and the reaction product is difficult to be subjected to ordinary distillation separation. Therefore, the extractive distillation method can be advantageously used. When the extractive distillation method in which a solvent such as adiponitrile, sulfolane or dimethylacetamide is coexistent is used, the specific volatility can be increased by the affinity of each component, and the separation by distillation can be performed. More specifically, since the specific volatility of cyclohexene and cyclohexane with respect to benzene is 1.5 to 3 and 2 to 6, first, cyclohexene and cyclohexane are isolated from unreacted benzene, and then cyclohexene is isolated from cyclohexane to obtain cyclohexene. Alternatively, benzene and cyclohexene may be first isolated from cyclohexane and then cyclohexene may be isolated from benzene to obtain cyclohexene. By this method, the produced cyclohexene can be easily isolated. As mentioned above, since cyclohexane and benzene can be separated from each other, benzene can be used again as a starting material and cyclohexane for other useful purposes. Examples of the extractive distillation method as described above include JP-A-58-164524 using a dimethylacetamide solvent, JP-A-57-47628 using a sulfone compound solvent, JP-A-57-55129 using an aliphatic dinitrile compound, and dimethyl ester. A mixed solvent of acetamide and adiponitrile is used.
There is 0.

The specific means for carrying out the method for partially hydrogenating a monocyclic aromatic hydrocarbon according to the present invention will be described below with reference to FIGS.
It is not limited to these examples.

FIG. 1 is a schematic diagram showing an internal sectional view of a reaction vessel for carrying out one embodiment of the method of the present invention. The reaction tank 4 is a stirrer; a thermometer sheath tube (not shown);
A common pipe for supplying an oil phase containing a monocyclic aromatic hydrocarbon introduced through a pipe 1 and water introduced through a pipe 2 to a reaction tank through a disperser; a gas phase including hydrogen gas is supplied through a disperser. A pipe 3; a reaction product outlet (which is connected to the pipe 5) for extracting the produced cyclohexene; and a pressure gauge (not shown) are provided. Further, in the reaction tank 4, a weir 6 that penetrates the gas-liquid free surface is arranged near the product outlet, and a stationary area is provided to facilitate oil-water separation. Furthermore, the reaction vessel is equipped with an electric heater (not shown) for adjusting the temperature inside the reaction vessel. A flow meter is attached to each of the pipes 1 to 3 (not shown). The reaction product withdrawal port connected to the pipe 5 is arranged at the upper part of the reaction tank. Further, a glass observation window (not shown) is attached to the side wall of the reaction tank in order to observe the oil-water separation state in the stationary area.

According to the above aspect of the present invention, the reaction system is provided with a shearing force such that the maximum shearing rate is about 50 to about 2000 / sec, and the oil phase and the gas phase are respectively dropped in the continuous aqueous phase. And the reaction is carried out in a reaction tank having a stirrer having a plurality of stirring blades for dispersing as bubbles, and the stirrer is operated to stir the entire reaction system in the reaction tank so that the catalyst suspended in the continuous aqueous phase is allowed to settle. A method for preventing bubbles and re-dispersing coalesced bubbles and oil droplets at a distance from the stirring blade to maintain a gas phase in a continuous aqueous phase in a bubble state and an oil phase in an oil droplet state is provided. It

The shape of the reaction tank 4 may be a vertical type, a horizontal type, a rectangular type, a cylindrical type, or the like, but it is preferable that there is no slurry accumulation or liquid stagnation as much as possible, and a vertical type cylindrical phase is most preferable. The type of the stirring blade 7 is preferably a blade structure such as a turbine, a propeller or a paddle. Turbine blades are more preferable in the method of the present invention in which gas dispersion is important. The shaft of the stirrer does not necessarily have to be at the center of the reaction tank, and the number of stirrers to be mounted need not be one. Moreover, it becomes more effective if a baffle plate is inserted. One or more baffle plates extending vertically fragrant are arranged near the side wall of the reaction tank. The longer the baffle plate, the more effective the circulation flow in the vertical direction.

In the method of the present invention, it is possible to circulate the gaseous phase of hydrogen gas and the oil phase containing monocyclic aromatic hydrocarbons as a mixture with the aqueous phase by allowing the stirrer in the reaction tank to have a downward flow component. preferable. Specifically, in order to mix the gas phase and the oil phase, which are lighter than the specific gravity of the water phase, with the water phase, the agitated reaction system must include a downward flow component that entrains bubbles and droplets that have risen. Is preferred. The direction of flow may be downward at the center or outward as shown in FIG. However, basically the bubbles rise and are finally released from the gas-liquid interface. In order to secure a sufficient residence time for the rise of the bubbles, it is desirable to set the height direction higher than the inner diameter of the reaction tank. At least the ratio of the reaction system depth to the inner diameter of the reaction vessel is preferably 1 or more. More preferably, the ratio of the reaction system depth to the inner diameter of the reaction tank is 1 to 10. If this ratio is increased, the shaft of the stirrer becomes longer and there is a risk of shaft runout.

The hydrogen gas may be supplied just below the stirring blade 7 at the lower part of the reaction tank by only the supply pipe, but as shown in FIG. 1, a pipe 3 equipped with a disperser (head) is used to appropriately disperse the hydrogen gas. Is more desirable to supply. As such a hydrogen gas supply / dispersion device, a device having a large number of holes of 1.0 to 50 mmφ may be used. Further, similarly, the monocyclic aromatic hydrocarbons are also appropriately dispersed and supplied just below the stirring blade 7 at the lower part of the reaction tank by using the pipe 1 equipped with a disperser (head) as shown in FIG. It is more desirable to do. In particular, since monocyclic aromatic hydrocarbons may short-pass the reactor and reduce the reaction yield, a position away from the reaction product withdrawal position is preferable. As such a monocyclic aromatic hydrocarbon supply / dispersion device, one having a large number of holes of 1.0 to 75 mmφ may be used. Regarding the blades attached to the stirrer, a set of stirring blades arranged on the same plane (hereinafter,
A single "stirring blade set" may be used, or a multi-stage type may be used. Further, the blade type of each stage of the multi-stage blade may be different. In particular, the lowermost blade (first stirring blade set) has a function of generating and dispersing bubbles and oil droplets in the continuous aqueous phase and mixing the entire reaction system.

In the industrial size, the hydrogen gas existing in the upper part of the reaction tank is less likely to be absorbed than the gas-liquid free surface. In that case, it becomes necessary to purge the gas, but if it is simply discharged to the outside of the system, it will result in a loss correspondingly, increasing the consumption of hydrogen gas. Therefore, it is conceivable that the purge gas is recompressed and resupplied to the lower portion of the reaction tank. However, this requires a recompression circulation compressor, which complicates the reaction apparatus. Therefore, the present inventors have made a study to eliminate the need for a gas circulation compressor by absorbing the gas accumulated in the upper part of the reaction tank again from the gas-liquid free surface,
The stirring blade is multi-staged, and the stirring blade set (second stirring blade set) is placed at a position where the gas existing above the gas-liquid free surface in the reaction tank is entrained in the reaction system when the stirring machine is operated. It has been found that it is desirable to provide this and carry out the entrainment with this second set of stirring blades. The position differs depending on the blade type and stirring strength, and by making the gas-liquid free surface undulate to increase the interfacial area, it becomes possible to absorb the gas above the gas-liquid free surface into the reaction system again. It is effective to provide a stirring blade within 1 m from the gas-liquid free surface. Further, by providing a draft tube or the like near the stirring shaft, it is possible to promote gas entrainment. These gas entrainment methods, which are called cavitation, are effective for absorbing gas from the gas-liquid free surface.

In order to separate only the oil phase in which the oil / water is separated and the cyclic olefin is present, as shown in FIG. 1, a weir 6 is provided near the reaction product outlet of the reaction tank (which is connected to the pipe 5), and a weir 6 is installed. It can be achieved as a storage area. That is, by allowing the reaction mixture to stand, oil droplets rise to form a continuous layer of an oil phase and a continuous aqueous phase, and the continuous oil phase is extracted through a pipe 5 to remove a cyclic olefin. Let go. On the other hand, since the continuous aqueous phase has a large specific gravity, it descends and is replaced with the reaction mixture. As another method, the reaction liquid is gas-liquid separated in a gas-liquid separation tank provided outside the reactor, the separated liquid layer is subsequently oil-water separated in an oil-water separation tank, and the supernatant oil phase is used as a reaction product. On the other hand, the lower aqueous phase is extracted together with the catalyst and returned to the reactor using a circulation pump or gravity (not shown). Examples of gas-liquid separation tanks and oil-water separation tanks provided outside the reaction tank are shown in FIGS.
The same gas-liquid separation tank 8 and oil-water separation tank 9 shown in and 5 can be used.

Referring again to FIG. 1, when there is a bubble of hydrogen gas in the stationary region upon separation of oil and water, the bubble raises the catalyst to the continuous oil phase side, and the catalyst of the reactor Since the gas leaks from the stationary area together with the reaction product (oil phase), the baffle plate 1 as shown in FIG. 1 is provided near the inlet of the stationary area so that air bubbles do not easily enter the stationary area.
It is desirable to provide 3. Further, even when a gas-liquid separation tank and an oil / water separation tank are provided outside the reaction tank, a retention section for degassing is provided when the reaction mixture of oil / water is supplied so as not to mix bubbles in the oil / water separation tank. Desirably, a portion such as a downcomer of a conventional sheep tray type distillation column is provided, and it is desirable that the reaction mixture is fed to the oil-water separation gently so that no bubbles are generated. From this viewpoint, it is desirable that the gas-liquid separation tank has a structure such as the gas-liquid separation tank 8 shown in FIGS.

According to another aspect (second aspect) of the present invention, partial hydrogen is obtained by using a plurality of reaction vessels which are connected in series and which are composed of a first reaction vessel and at least one supplementary reaction vessel. Of the reaction mixture containing the cyclic olefin and the unreacted monocyclic aromatic hydrocarbon obtained in the first reaction tank or the complementary reaction tank preceding the at least one complementary reaction tank. A method is provided for introducing into the next complementary reaction vessel of the reaction vessel, where the unreacted aromatic hydrocarbons are partially hydrogenated.

FIG. 2 schematically shows an apparatus for carrying out the second embodiment of the process according to the invention, which uses two stirred reaction vessels connected in series. The reaction tank 4-1 is a stirrer; a thermometer sheath pipe (not shown); an oil phase containing monocyclic aromatic hydrocarbons introduced through the pipe 1 and water introduced through the pipe 2 are reacted through a disperser. Common pipe for supplying to the tank; Pipe 3 for supplying a gas phase containing hydrogen gas through a disperser; Reaction product outlet for extracting the reaction mixture generated in the reaction tank 4-1 (connected to the pipe 5A-1) And a pressure gauge (not shown). Further, the reaction tank 4-1 is equipped with an electric heater (not shown) for adjusting the internal temperature of the reaction tank. A flow meter is attached to each of the pipes 1 to 3 (not shown). Pipe 5
The reaction product withdrawal port connected to A-1 is arranged above the reaction tank 4-1. Furthermore, in order to observe the inside of the reaction tank, a glass viewing window (not shown) is attached to the side wall of the reaction tank. The gas existing in the upper part of the reaction tank 4-1 is
The gas is discharged through the gas discharge pipe 12-1. The pipe 5A-1 for extracting the reaction product is connected to the lower portion of the supplementary reaction tank 4-2, and the pipe 3 for supplying a gas phase containing hydrogen gas
Is also connected to the lower part of the supplementary reaction tank 4-2 and below the connection part of the pipe 5A-1. The disperser attached to the tip of the pipe 5A-1 as shown in FIG. 2 may be omitted. The gas existing in the upper part of the reaction tank 4-2 is the gas exhaust pipe 12-2.
Exhaust through. Various equipment of the reaction tank 4-2, such as a pressure gauge, is the same as that of the reaction tank 4-1. Reaction tank 4-
The reaction product withdrawing pipe 5A-2 of 2 is connected to the gas-liquid separation tank 2, and the gas-liquid separation phase 8 is introduced into the reaction mixture obtained in the reaction tank 4-1. In the gas-liquid separation tank 8,
The gas phase containing hydrogen gas is separated from the liquid phase consisting of the oil phase and the water phase and discharged from the gas discharge pipe 12-3. The gas-liquid separation tank 8 is connected to the upper part of the oil-water separation tank 9 at its lower part, and the liquid phase is introduced into the oil-water separation phase 9. Oil water separation tank 9
Then, the liquid phase is separated into an oil phase (upper layer) containing the produced cyclic olefin and water, and an aqueous phase containing the hydrogenation catalyst suspended therein. The obtained oil phase is withdrawn from the reaction product withdrawing pipe 5, while the aqueous phase is withdrawn through the pipe provided at the bottom of the oil / water separation tank, and is recirculated to the reaction tank 4-1 through the circulation pipe 10 by the pump 11. Bring to reflux. All pipes have their own flow meters.

As described above, by using a plurality of reaction mixture solutions to bring them closer to the extruding flow, it is possible to increase the selectivity of the target cyclic olefin. This is because the target product of the method of the present invention is an intermediate product of a sequential reaction, and therefore, when the reaction mixture is extruded and moved using a plurality of reaction vessels, the concentration of the monocyclic aromatic hydrocarbon is maximized. This is because it is possible to promote the production of the cyclic olefin, and at the same time, it is possible to suppress the further conversion of the cyclic olefin into the by-product cycloparaffin. The effect of the second aspect of the method of the present invention using a plurality of reaction vessels connected in series as described above is divided into a plurality of small chambers arranged in multiple stages by obstacles, and each chamber has at least one stirring blade set. It can also be achieved using a reaction vessel configured to include

Therefore, according to yet another aspect (third aspect) of the present invention, as shown in FIG. 3, the reaction tank 4 having a stirrer provided with a plurality of stirring blades 7 for generating shearing force.
The reaction is carried out in step (1), the plurality of stirring blades 7 are composed of a plurality of stirring blade sets arranged in a multi-stage manner, and the reaction tank 4 is divided by an obstacle 14 into a plurality of small chambers arranged in a multi-stage manner.
Each chamber is configured to include at least one set of stirring blades.

In the third embodiment of the method of the present invention, the agitator is operated to agitate the entire reaction system in each chamber to prevent the catalyst suspended in the continuous aqueous phase from settling, and from the agitating blades. The bubbles and oil droplets that have coalesced at a distance are redispersed to maintain the gas phase in the continuous aqueous phase in the form of bubbles and the oil phase in the form of oil drops. Further, between the two small chambers adjacent to each other divided by the obstacle 14, the reaction system starts flowing from the first small chamber to the second small chamber according to the predetermined direction, and at the same time, the reaction system becomes The reaction system of the second small chamber is prevented from reversely mixing with the reaction system of the first small chamber by preventing the backward flow in the above direction. In this way, each room divided by the obstacle 14
Functions the same as a single reaction vessel equipped with a stirrer.

The obstacle 14 is not particularly limited, and for example, a perforated plate, a wire mesh, a plate of a donut type or a half moon type, a grid grid deck, a mountain type aruguru deck, a gap is provided between the inner wall of the reaction vessel. It may be a combination of discs or the like. 4 to 6 show three kinds of obstacles. FIG. 4 shows a perforated plate 15 which is an example of an obstacle installed in the reaction tank. FIG. 5 shows a doughnut-shaped plate 16 which is another example of the obstacle mounted in the reaction tank. FIG. 6 shows a disk, which is still another example of the obstacle installed in the reaction tank, and is installed with a gap between the disk and the inner wall of the reaction tank. The disk 17 is fixed to the inner wall of the reaction vessel by a support 18. When using the obstacles shown in FIGS. 4 to 6, the reaction system flows in the directions of the arrows shown in the respective drawings. In each chamber stirring space partitioned by the obstacle 14, the height ratio between obstacles is preferably 0.2 to 2 with respect to the tank diameter. The type of the stirring blade 7 may be different in each stirring space. The placement of the blades in each stirring space is preferably near the center of the obstacle, but there is no problem in terms of function as long as it can be sufficiently stirred even if it is slightly up and down.

In the third aspect of the method of the present invention, the uppermost chamber includes an uppermost stirring blade set of a plurality of stirring blade sets, the uppermost stirring blade set operating the stirrer. It is preferable that the gas existing above the gas-liquid free surface in the reaction tank is provided at a position so as to be wound into the reaction system, and the gas is taken in by the uppermost stirring blade set.

In order to obtain a reaction product containing a cyclic olefin, instead of using a recirculation route through the gas-liquid separation tank 8 and the oil / water separation tank 9 as shown in FIG. 3, a pipe 5B is provided as shown in FIG. The reaction product outlet to be connected and a weir (not shown) in the vicinity thereof are arranged to provide a standing region, whereby the resulting reaction mixture contains an oil phase as an upper layer containing cyclic olefin and a hydrogenation catalyst. A method that facilitates separation into the aqueous phase as the lower layer may be used. In this case, the reaction product outlet and the weir are arranged in the uppermost small chamber, and the baffle plate for preventing air bubbles from being mixed into the stationary area is arranged near the stationary area inlet.

Further, as shown in FIG. 3, the reaction liquid mixture obtained in the reaction tank 4 is directly introduced into a gas-liquid separation tank provided outside the reaction tank to perform gas-liquid separation, and the obtained liquid is separated into oil and water. Introduced into the tank, after separating the oil phase as the upper layer containing cyclic olefin from the aqueous phase as the lower layer containing water and the catalyst suspended therein, the upper phase oil phase is taken out, while the lower layer water phase May be recirculated to the reaction tank.

In the third embodiment of the present invention which uses the above-mentioned reaction vessel provided with obstacles (multi-stage stirring blade row type reaction vessel), the reaction system becomes an extruding flow through a plurality of small chambers arranged in a multi-stage manner, and once. Not only does the reaction yield increase each time it flows through the reaction tank, but also the gas holdup increases, so that there is the effect that the absorption of hydrogen gas improves.

FIG. 7 shows a schematic view of a reactor for carrying out still another embodiment (fourth embodiment) of the method of the present invention.
According to the fourth aspect, the reaction is carried out in the pipe-shaped reactor by circulating the reaction system at a flow velocity sufficient to generate a shearing force such that the maximum shearing rate is about 50 to about 2000 / sec. A method is provided. In the reactor of FIG. 7, the oil phase, the water phase and the gas phase are introduced into the pipe reactor 4 through pipes 1, 2 and 3, respectively, and the reaction system has a flow velocity sufficient to generate the above specific shear force. Circulate.

The shape of the pipe-shaped reactor 4 may be cylindrical, prismatic, or the like, but it should have a sufficient length with respect to the diameter of the pipe so as to give a pushing flow as described in the stirring tank reactor. Is desirable. As described above, the flowing speed needs to be a speed that forms fine bubbles and fine oil droplets of hydrogen gas, but if the flowing speed is too high, the pressure loss between the inlet and outlet of the pipe-shaped reactor 4 becomes large, The hydrogen concentration in the aqueous phase in the downstream is lowered, and the selectivity of cyclic olefin is lowered. When supplying hydrogen gas or monocyclic aromatic hydrocarbons to the reaction field, only the supply pipes may be provided, but if a disperser having a large number of openings is attached to the supply pipes, more preferable bubbles can be obtained.

A gas-liquid separation tank 8 is provided on the outlet side of the pipe-shaped reactor 4 in order to facilitate oil-water separation after the reaction and to take out only the oil phase in which the cyclic olefins are present. That is,
A reaction liquid mixture composed of a gas containing hydrogen gas and a liquid containing an oil phase and an aqueous phase is introduced into a gas-liquid separation tank provided outside the reactor 4 to perform gas-liquid separation. The hydrogen gas is discharged from the pipe 12, and the obtained liquid is introduced into the oil-water separation tank 9 to change the water phase as a lower layer containing water and the catalyst suspended therein from the oil phase as an upper layer containing a cyclic olefin. After separation, the upper oil phase is withdrawn from the pipe 5, while the lower aqueous phase is recirculated using the reactor 4, eg pump 11.

By the way, in the above-mentioned fourth embodiment, when hydrogen gas is flown from the pipe 3, the hold-up of hydrogen gas in the reaction system is not sufficient, so that the reaction rate tends to be the rate-determining rate of hydrogen gas absorption. Therefore, in order to enhance the hold-up of hydrogen gas, the hydrogen gas collected by gas-liquid separation in the gas-liquid separation tank 8 is returned from the pipe 12 to the pipe-shaped reactor 4 by using, for example, a circulation compressor. By forming a circulation system, it is possible to obtain a sufficient amount of fine bubbles for the reaction. Since the pipe-shaped reactor 4 according to the fourth aspect of the present invention becomes an extruding flow, it is desirable to improve the selectivity and yield of the cyclic olefin, but in order to improve the absorption of hydrogen gas, a circulation compressor is used. It becomes a complicated reaction system. On the other hand, the stirring tank type according to the first to third aspects of the present invention (for example, FIGS. 1 to 3) is a simple reaction system, and if anything, the stirring tank type is more preferable.

[0053]

The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples. Example 1 A hydrogenation catalyst for metal ruthenium particles having an average crystallite size of 55 Å and a zinc content of 7.4% by weight was suspended in an aqueous phase, and the partial hydrogenation reaction of benzene was carried out as follows. I went under the conditions. As a partial hydrogenation reactor, as shown in FIG. 1, a thermometer was provided inside a pressure-resistant reactor equipped with a stirrer and having an inner volume of 4 liters, the inner surface of which was coated with Teflon (registered trademark of polytetrafluoroethylene manufactured by DuPont, USA). Saya pipe (not shown) -Common pipe for supplying an oil phase containing monocyclic aromatic hydrocarbons introduced through pipe 1 and water introduced through pipe 2 to a reaction tank through a disperser (head) -hydrogen A pipe 3 for supplying a gas phase containing a gas through a disperser (head), a reaction product outlet (connected to the pipe 5), and a pressure gauge (not shown) were attached, and the stirring blade 7 was a single stage turbine blade. . A weir 6 penetrating the gas-liquid interface was provided in the vicinity of the outlet for the reaction product to provide a stationary area for separating oil and water. Further, an electric heater for temperature control was attached to the outer surface of the reaction tank. A flow meter (not shown) was attached to each pipe. The reaction product outlet (connected to the pipe 5) was provided at the top of the reaction tank. In addition, in order to observe the separated state of oil and water and measure the interface position, a glass viewing window attached to the side of the reaction tank was provided.

In the hydrogenation reaction, after first purging the inside of the apparatus with nitrogen, 9.8 g of the above hydrogenation catalyst, 1.40 liters of water, 248 g of ZnSO ₄ .7H ₂ O, ZrO ₂ powder (average particle size 0.35 micron) Charge 49g into the reaction tank,
The stirrer was rotated at 600 rpm, the temperature was raised by an electric heater, and the temperature inside the reaction tank was controlled to be constant at 140 ° C. Hydrogen gas is pressed in to keep the total pressure in the reaction tank at 50 kg /
The flow rate is 1.2 kg / h at a steady state by gradually supplying fresh benzene liquid while controlling to keep the cm ² constant.
r. The oil-water interface level in the stationary region in the reaction tank was positioned below the reaction product outlet, and water corresponding to the amount of water dissolved in the reaction product and carried out was supplied through the pipe 2. The gas-liquid interface level was kept constant by making the pipe 5 an overflow type. Another observation window was attached to the side wall of the reaction tank, and the inside of the reaction tank was observed from there. As a result, the blown hydrogen gas was formed into fine bubbles, and the oil phase was formed into fine droplets and was relatively uniformly dispersed in the reaction tank. After stabilizing the whole system, the composition of the reaction product extracted from the pipe 5 was analyzed. As a result, the conversion rate of benzene = 38%, the cyclohexene selectivity = 80%, and the by-product was cyclohexane. This value is the reaction result in the reaction-controlled state and is a satisfactory value. The maximum shear rate at the stirring blade at this time was about 440 / sec. The average droplet diameter of the oil phase in the reaction tank was 0.1 mm. The reaction product extracted had no catalyst at all, and was in a good oil / water separation state. Subsequently, in order to evaluate the oil-water separation time in the stationary area, the raw material supply and stirring were temporarily stopped at the same time.
Twenty-three seconds after the stirring was stopped, a continuous oil phase was formed as the upper layer and a continuous aqueous phase was formed as the lower layer, and the oil droplets existing between the two phases were completely extinguished. The volume ratio of the oil phase to the water phase in the reaction system was 0.25.

Examples 2 and 3 Using the reactor of Example 1, the reaction conditions were the same as in Example 1 and the reaction results were observed by changing only the rotation speed of stirring. The results are shown in Table 1. This value is the reaction result in the reaction-controlled state and is a satisfactory value. The reaction product extracted had no catalyst at all, and was in a good oil / water separation state.

Comparative Example 1 Using the reaction apparatus of Example 1, the reaction conditions were the same as in Example 1, but the agitator rotation speed was 6 rpm instead of 600 rpm.
When the reaction was carried out at 00 rpm, the conversion rate of benzene in the reaction product was 4%, and the selectivity to cyclohexene was =
45% and the by-product was cyclohexane. The dispersed state during stirring was a state in which an oil continuous phase was present in the upper part of the reaction system and two phases were separated, and almost no oil dispersed phase was observed. The maximum shear rate at this time was 44 / sec.

Example 4-1 Using the same hydrogenation catalyst as in Example 1, a partial hydrogenation reaction of benzene was carried out under the following conditions. As the partial hydrogenation reactor, a pressure resistant reactor with a stirrer of the same type as in Example 1 was used except that the internal volume was 4000 liters instead of 4 liters. The stirring blade was a two-stage turbine blade. A weir plate that penetrates the gas-liquid interface is provided near the reaction product extraction nozzle,
It was set as a stationary area for separating oil and water. Further, a jacket was attached to the outer surface of the reactor instead of the electric heater for temperature control. Various pipes including the pipes 1, 2 and 3, a pressure gauge, a flow meter, a viewing window, etc. were the same as those in the first embodiment. Hydrogenation reaction, after the interior of the apparatus was purged with nitrogen at the beginning, the hydrogenation catalyst 14.7 kg, water 2100 liters, ZnSO ₄ · 7
372 g of H ₂ O and 74 g of ZrO ₂ powder (average particle size 0.35 micron) were charged in a reaction tank, and a stirrer was set to 108 rp.
After rotating at m, steam was introduced into the jacket outside the reaction tank to raise the temperature inside the reaction tank to 140 ° C. Hydrogen gas was injected under pressure so that the total pressure in the reaction tank was constantly kept constant at 50 kg / cm ² , and a fresh benzene solution was gradually supplied to a steady state of 1870 kg / hr. After the reaction was started, cooling water was introduced into the jacket to control the temperature in the reaction tank to be constant at 140 ° C. The oil / water interface level in the stationary area in the reaction tank is located below the reaction product outlet (connected to the pipe 5), and the amount of water commensurate with the amount of water taken out by dissolving in the reaction product is taken out. Was supplied through pipe 2. The gas-liquid interface level was kept constant by making the pipe 5 an overflow type. As a result of observing the inside of the reaction vessel through a viewing window attached to the side wall of the reaction vessel, the hydrogen gas blown into became fine bubbles, and the oil phase became fine droplets, which were relatively uniform in the reaction vessel. It was dispersed. Bubble diameter of hydrogen gas is about 2 mm
It is estimated to be the degree. The gas purge from the hydrogen gas discharge pipe 12 at the upper part of the reaction tank was set to 0 for operation. After the whole system was stabilized, the composition of the reaction product extracted from the pipe 5 was analyzed. As a result, the conversion of benzene = 39%, the selectivity of cyclohexene = 8.
0% and the by-product was cyclohexane. This value is the reaction result in the reaction-controlled state and is a satisfactory value.
The maximum shear rate at the stirring blade at this time is about 860 /
It was sec. The average droplet diameter of the oil phase in the reaction tank is 0.2
It was mm. The reaction product extracted had no catalyst at all, and was in a good oil / water separation state. Subsequently, the stirring and the raw material supply were temporarily stopped simultaneously, and the oily separation time was evaluated in batches. As a result, 5 minutes after the stirring was stopped, a continuous oil phase was formed in the upper part and a continuous aqueous phase was formed in the lower part, and the dispersed phase of the intermediate oil droplets disappeared completely. At this time, the volume ratio of the oil phase to the water phase in the reaction liquid was 0.3, and the gas holdup was 0.03.

Example 4-2 Under the reaction conditions of Example 4-1, the change with time of the metal ruthenium crystallite diameter, which is an index of the catalytic activity, was measured. The result is shown in Figure 6.
It is as follows. The increase in the metal ruthenium crystallite size with time was very small, and the catalytic activity was stable. 2
As a result of operating for 0 days, the conversion of benzene = 38%, the selectivity of cyclohexene = 81%, and the by-product was cyclohexane. There was almost no decrease in activity, the oil-water separation state in the stationary region was good, and no catalyst was mixed in the extracted reaction product.

Comparative Example 2-1 Using the reaction apparatus of Example 4, the reaction conditions were those of Example 4-1.
When the reaction was carried out at 200 rpm instead of 108 rpm, the conversion rate of benzene in the reaction product obtained after the start of operation was 38%.
The selectivity to cyclohexene was 81%. The diameter of the metal ruthenium crystallite at that time was 61 angstrom. At this time, the average droplet diameter of the oil phase in the reaction tank was 0.015.
It was mm. Subsequently, the stirring and the supply of the raw materials were temporarily stopped at the same time, and the oily separation time was evaluated in batches. As a result, a part of the oil phase remained as oil droplets even 10 minutes after the stirring was stopped.

Comparative Example 2-2 Under the same conditions as in the reaction carried out in Comparative Example 2-1, the change with time of the crystallite diameter of metallic ruthenium was measured. The results are shown in Fig. 8. Conversion rate of benzene in the reaction product after 22 days = 2
4% and the selectivity to cyclohexene = 79%. The shear rate at this time was 2200 / sec, and the decrease in activity over time was extremely fast.

Example 5 A partial hydrogenation reaction of benzene was carried out by using the same reaction tank as in Example 4 and using the same hydrogenation catalyst as in Example 1, except that the stirring blade was changed to a two-stage propeller blade. The procedure was similar to that in Example 4-1. The rotation speed of the stirrer was 45 rpm instead of 108 rpm. The reaction vessel temperature is 0.99 ° C. instead of 140 ° C., the reaction vessel total pressure of 70 kg / cm ² instead of 50 kg / cm ^2, benzene feed rate 1,8
It was 70 kg / hr. After the whole system was stabilized, the inside of the reaction vessel was observed through a viewing window attached to the side wall of the reaction vessel. As a result, the hydrogen gas blown into the reaction vessel became fine bubbles and the oil phase became fine droplets. Each was relatively evenly dispersed. The bubble diameter of hydrogen gas was estimated to be about 13 mm.
In addition, there are oil droplets of several mm to several tens of mm, and the average droplet diameter was about 24 mm. As a result of analyzing the reaction product composition extracted from the pipe 5, the conversion rate of benzene =
37%, cyclohexene selectivity = 78%, and the side reaction product was cyclohexane. This value was a reaction result that was close to the reaction-limited state, and was a relatively satisfactory value. The maximum shear rate at this time is 70 / sec.
Met. There was no catalyst in the reaction product, and a good oil / water separation state was obtained.

Example 6-1 Using the reaction vessel of Example 4-1, the reaction conditions are the same as in Example 4, but the temperature in the reaction vessel is 125 ° C instead of 140 ° C.
℃, the total pressure in the reaction tank is 4 kg instead of 50 kg / cm ^2.
5 kg / cm ² and the agitator rotation speed is 108 rp
Instead of m, the reaction was performed at 175 rpm. After the whole system was stabilized, the inside of the reaction vessel was observed through a viewing window attached to the side wall of the reaction vessel. As a result, the hydrogen gas blown into the reaction vessel became fine bubbles and the oil phase became fine droplets. Each was relatively evenly dispersed. At this time, the average droplet diameter of the oil phase in the reactor was 0.04 mm, and the bubble diameter of hydrogen gas was about 1.2 mm. As a result of analyzing the extracted reaction product, the conversion rate of benzene was 32% and the selectivity of cyclohexene was 82%. At this time, the crystallite diameter of the metal ruthenium was 56 Å. This value was a reaction result that was close to the reaction-limited state, and was a relatively satisfactory value. Maximum shear rate with a stirring blade is 1800 / sec
Met. There is no catalyst in the extracted reaction product,
It was in a good oil / water separation state.

Example 6-2 After that, the reaction was continued and the reaction product extracted from the pipe 5 after 15 days was analyzed. As a result, the conversion rate of benzene = 3.
0%, cyclohexene selectivity = 82%, and the by-product was cyclohexane. The metal ruthenium crystallite size was 65 Å, the increase with time was very small, and the catalytic activity was stable.

Example 7 Using the same hydrogenation catalyst as in Example 1, a partial hydrogenation reaction of benzene was carried out under the following conditions. As a partial hydrogenation reactor, as shown in FIG. 7, is introduced through a thermometer sheath pipe (not shown) and pipe 1 into the inlet of a pipe reactor 4 having an inner volume of 4000 liters with an inner surface coated with Teflon. Oil phase containing monocyclic aromatic hydrocarbons and pipe 2
A common pipe for supplying water introduced through the disperser (head) to the reaction tank, a pipe 3 for supplying a gas phase containing hydrogen gas through the disperser (head), and a pressure gauge (not shown), A thermometer sheath pipe (not shown) and a pressure gauge (not shown) were attached to the outlet of the pipe-shaped reactor 4. A gas-liquid separation tank 8 is provided outside the reactor 4, an oil / water separation tank is connected to the lower part of the reactor, and a reaction product outlet (connected to the pipe 5) is connected to the upper part of the oil / water separation tank. In the lower part of the oil / water separation tank, a circulation pipe 10 for returning the water phase extraction pipe to the inlet of the pipe-shaped reactor 4 via a circulation pump 11.
Was set up. A flow meter was attached to each pipe. The pipe-shaped reactor 4 has a double-pipe structure, steam is introduced into the gap tubes of the outer and inner pipes during heating, and cooling water is introduced during cooling to control the inside of the pipe-shaped reactor to a constant temperature. . In the hydrogenation reaction, the inside of the apparatus was first purged with nitrogen, and then the hydrogenation catalyst, water and Zn were used in the same manner as in Example 1.
SO ₄ .7H ₂ O and ZrO ₂ powder having the same composition as in Example 1 were charged in the pipe-shaped reactor 4, gas-liquid separation tank 8, oil-water separation tank 9, circulation pump 11 and circulation pipe 10, and the circulation pump 11 was used. Circulate the water phase at 50,000 liters / hr,
The temperature inside the reactor is set to 1 by heating the pipe reactor with steam.
The temperature was controlled to be constant at 40 ° C. Hydrogen gas was injected under pressure so that the total pressure in the reactor was constantly kept constant at 50 kg / cm ² , and the hydrogen gas flow rate was supplied at 1200 Nm ³ / hr. Fresh benzene solution was gradually supplied to 2000 kg / hr in a steady state. The oil / water interface level of the oil / water separation tank 9 should be located below the reaction product outlet (connected to the pipe 5), and the amount of water corresponding to the amount of water dissolved in the reaction product and taken out should be piped. Supplied through 2. The gas-liquid interface level was kept constant by controlling the amount of reaction product withdrawn. After the whole system was stabilized, the composition of the reaction product extracted from the pipe 5 was analyzed. As a result, the conversion rate of benzene = 55%, the cyclohexene selectivity = 79%
And the by-product was cyclohexane. This value is the reaction result in the reaction-controlled state and is a satisfactory value. The maximum shear rate of the fluid in the pipe-shaped reactor at this time was about 750 / sec. The average droplet size of the oil phase in the reactor was 0.5 mm. The reaction product extracted had no catalyst at all, and was in a good oil / water separation state.

Examples 8 and 9 Using the reactor of Example 7, the reaction conditions were the same as in Example 7, except that the circulating amount of the aqueous phase was 80,000 liters / hr in Example 8 and 30 in Example 9. 1,000 liter / h
The reaction results were observed in place of r. The results are shown in Table 2, and the reaction results were good.

Comparative Example 3 Using the reactor of Example 7, the reaction conditions were the same as in Example 7, but the aqueous phase liquid was circulated at 3000 liters / hr,
The hydrogen gas flow rate was 1000 Nm ³ / hr. Gradually supply a fresh benzene solution and keep it steady 200
When the flow velocity of the fluid in the pipe-shaped reactor was dropped at 0 kg / hr, the reaction system formed a two-phase flow of a liquid phase (including an oil phase and an aqueous phase) and a gas phase, and formed fine bubbles and oil. It moved through the reactor without producing drops. Regarding volume,
The gas phase was larger than the liquid phase. As a result of analyzing the reaction product extracted from the pipe 5, the conversion rate of benzene = 7
%, Cyclohexene selectivity = 60%, and the by-product was cyclohexane. The maximum shear rate at this time is 3
It was 8 / sec.

Example 10 Using the same hydrogenation catalyst as in Example 1, a partial hydrogenation reaction of benzene was carried out under the following conditions. As a partial hydrogenation reactor, as shown in FIG. 3, a multi-stage stirring blade row type reaction tank 4 having an inner volume of 8000 liters, the inner surface of which is coated with Teflon, is used, and a thermometer sheath pipe (not shown) is provided in the lower portion・
A common pipe for supplying an oil phase containing a monocyclic aromatic hydrocarbon introduced through a pipe 1 and water introduced through a pipe 2 to a reaction tank through a disperser (head), and a vapor phase including a hydrogen gas. A pipe 3 supplied through the (head) and a pressure gauge (not shown) were attached, and a thermometer sheath pipe (not shown) and a pressure gauge (not shown) were attached to the outlet of the reactor 4. A gas-liquid separation tank 8 is provided outside the reactor 4,
The hydrogen gas is discharged through the pipe 12, the oil / water separation tank 12 is connected to the lower part thereof, the reaction product outlet is provided on the upper part of the oil / water separation tank 12, and the water phase provided on the lower part of the oil / water separation tank 12 is provided. A circulation pipe 10 was provided for returning from the extraction pipe to the reactor inlet via the circulation pump 11. The stirring blade 7 is a six-stage turbine blade, and the reaction tank is divided into a plurality of small chambers arranged in multiple stages by an obstacle 14 using a perforated plate having a porosity of 5%, and each chamber has at least one stirring blade. It is configured to include a set. Between two adjacent small chambers separated by the obstacle 14, the reaction system is allowed to flow upward from the first small chamber toward the second small chamber, and at the same time, the reaction system is moved in the above direction. Backflow was prevented to prevent backmixing of the reaction system of the second compartment with the reaction system of the first compartment. Each pipe was equipped with a flow meter. The outer surface of the reaction tank 4 had a jacket structure, steam was introduced during heating, and cooling water was introduced during cooling to control the inside of the reaction tank to a constant temperature. In the hydrogenation reaction, first, the inside of the apparatus was purged with nitrogen, and then the hydrogenation catalyst, water, and ZnS were used as in Example 1.
O ₄ .7H ₂ O and ZrO ₂ powder having the same composition as in Example 1 were used as a multi-stage stirring blade row type reaction tank 4, gas-liquid separation tank 8, oil-water separation tank 9
Then, the circulation pump 11 and the circulation pipe 10 were charged, the stirrer was rotated at 90 rpm, and the circulation pump 11 was used to remove the water phase.
It was circulated at 5000 liter / hr, the temperature in the reaction tank was raised by steam, and the temperature was controlled to be constant at 140 ° C.
The total pressure inside the reaction tank is always 50 kg / c by injecting hydrogen gas.
controls so as to be m ² constant, and a purge gas = 0. A fresh benzene solution was gradually supplied to a steady state of 4000 kg / hr. The oil / water interface level of the oil / water separation tank 12 was positioned below the reaction product outlet, and water corresponding to the amount of water dissolved in the reaction product and taken out was supplied through the pipe 2. The gas-liquid interface level was kept constant by controlling the amount of reaction product withdrawn. After stabilizing the whole system, the composition of the reaction product extracted from the pipe 5 was analyzed. As a result, the conversion rate of benzene was 52%, the cyclohexene selectivity was 81%, and the by-product was cyclohexane. This value is the reaction result in the reaction-controlled state and is a satisfactory value. The maximum shear rate of the fluid in the multistage stirring blade type reactor 4 at this time was about 600 / sec. The average droplet size of the oil phase in the reactor was 0.3 mm. The reaction product extracted had no catalyst at all, and was in a good oil / water separation state.

[0068]

[Table 1]

[0069]

[Table 2]

[0070]

EFFECTS OF THE INVENTION According to the present invention, in the reaction system, the aqueous phase is made to be a continuous phase, the catalyst is suspended in the aqueous phase, and a shearing force is applied to the reaction system so as to obtain a specific shear rate. In the form of bubbles, and the oil phase containing monocyclic aromatic hydrocarbons is dispersed in the form of fine droplets to carry out the hydrogenation reaction, so that it is possible to provide a field for the reaction under the reaction rate, and to substantially reduce the selectivity and That is, a cyclic olefin can be obtained in good yield.
Furthermore, it has become possible to significantly suppress the decrease in the activity of the catalyst over time, and as a result, it is possible to maintain the high activity of the catalyst and the high selectivity of the cyclic olefin for a long time. Furthermore, it is easy to separate the oil / water of the reaction liquid in the stationary area after the reaction or in the oil / water separation tank, and the area or the separation tank can be made compact.

[Brief description of drawings]

FIG. 1 is an explanatory view of a stirring type reaction tank for carrying out the first embodiment of the method of the present invention.

FIG. 2 is an illustration of an apparatus using two stirred reaction vessels connected in series to carry out the second aspect of the method of the present invention.

FIG. 3 is an explanatory view of an apparatus using a multistage stirring blade row type reaction tank for carrying out the third aspect of the method of the present invention.

FIG. 4 is an explanatory diagram of a perforated plate that is an example of an obstacle installed in the reaction tank.

FIG. 5 is an explanatory diagram of a doughnut-shaped plate that is an example of an obstacle installed in the reaction tank.

FIG. 6 is an explanatory diagram of a disc that is an example of an obstacle installed in the reaction tank.

FIG. 7 is an illustration of a device using a pipe reactor for carrying out the fourth embodiment of the method of the present invention.

FIG. 8 is a graph comparing changes over time in the ruthenium metal crystallite diameter measured in Example 4 and Comparative Example 2.

[Explanation of symbols]

 1 monocyclic aromatic hydrocarbon supply pipe 2 water supply pipe 3 hydrogen gas supply pipe 4 reactor 5 reaction product withdrawal pipe 6 weir 7 stirring blade 8 gas-liquid separation tank 9 standing area or oil-water separation tank 10 water phase circulation Piping 11 Circulation pump 12 Hydrogen gas exhaust pipe 13 Puffle plate

Claims (17)

[Claims] 1. A method for partially hydrogenating a monocyclic aromatic hydrocarbon, which comprises producing a cyclic olefin by reacting a monocyclic aromatic hydrocarbon with hydrogen in the presence of a particulate hydrogenation catalyst containing ruthenium metal as a main component. Using a reaction system consisting of a continuous aqueous phase in which a particulate hydrogenation catalyst is suspended, an oil phase containing monocyclic aromatic hydrocarbons and a gas phase containing hydrogen, and a maximum shear rate of 50 to 2000 / sec. Thus, the reaction is performed by applying a shearing force to the reaction system to disperse the oil phase and the gas phase in the continuous aqueous phase as oil droplets and bubbles, respectively. 2. The average crystallite diameter of ruthenium metal is 200.
The method according to claim 1, wherein the method is equal to or less than on-glome. 3. The method according to claim 1, wherein the volume ratio of the oil phase to the continuous aqueous phase in the reaction system is 0.01 to 1.5. 4. The method according to claim 1, wherein the weight ratio of the hydrogenation catalyst to water in the reaction system is 0.001 to 0.2. 5. The method according to claim 1, wherein the reaction is carried out at a reaction temperature of 25 to 250 ° C. and a hydrogen partial pressure of hydrogen gas of 5 to 150 kg / cm ² . 6. The average oil droplet diameter of the oil phase is 0.02 to 30 mm.
The method according to any one of claims 1 to 5, wherein 7. The method according to claim 1, wherein the gas phase has an average bubble diameter of 0.4 to 20 mm. 8. The reaction is carried out in at least one reaction tank having a stirrer equipped with a plurality of stirring blades for generating the shearing force, and the stirrer is operated to stir the entire reaction system in the reaction tank, While preventing the sedimentation of the catalyst suspended in the continuous water phase, re-dispersing coalesced bubbles and oil droplets away from the stirring blade, the gas phase in the continuous aqueous phase into bubbles,
The method according to claim 1, wherein the oil phase is maintained in the form of oil droplets. 9. The reaction is carried out using a plurality of reaction vessels connected in series, which comprises a first reaction vessel and at least one supplementary reaction vessel, and precedes each of the at least one supplementary reaction vessel. The reaction mixture containing the cyclic olefin and the unreacted monocyclic aromatic hydrocarbon obtained in the first reaction tank or the complementary reaction tank is introduced into the complementary reaction tank next to each preceding reaction tank, and the unreacted aroma is introduced therein. The method according to claim 8, wherein the group hydrocarbon is partially hydrogenated. 10. The plurality of stirring blades comprises a plurality of stirring blade sets arranged in a multi-stage manner, and the plurality of stirring blade sets include a first stirring blade set and a second stirring blade set,
The first stirring blade set is provided at the lowermost stage to generate and disperse bubbles and oil droplets in the continuous aqueous phase and mix the entire reaction system, and the second stirring blade set is used when the stirrer is operated. 9. The gas existing above the gas-liquid free surface in the reaction tank is provided at a position so as to be wound into the reaction system, and the winding is performed by the second stirring blade set. 9. The method according to 9. 11. The reaction tank has a reaction product outlet, and a weir is arranged near the reaction product outlet to provide a standing region, and the reaction mixture obtained is used as an upper layer containing a cyclic olefin. The method according to any one of claims 8 to 10, which facilitates separation into an oil phase and an aqueous phase as a lower layer containing a hydrogenation catalyst. 12. The reaction according to any one of claims 1 to 7, wherein the reaction is carried out by flowing the reaction system in the pipe-shaped reactor at a flow velocity sufficient to generate the shearing force. the method of. 13. A reaction mixture comprising a gas containing hydrogen gas and a liquid containing an oil phase and an aqueous phase is introduced into a gas-liquid separation tank provided outside the reactor to perform gas-liquid separation, and thus obtained. The above liquid was introduced into an oil-water separation tank to separate an oil phase as an upper layer containing a cyclic olefin from an aqueous phase as a lower layer containing water and a catalyst suspended therein, and then an upper oil phase was taken out. 13. The process according to any of claims 8 to 10 and 12, characterized in that the lower aqueous phase is recirculated to the reactor again. 14. The reaction is carried out in a reaction vessel having a stirrer equipped with a plurality of stirring blades for generating shearing force, the plurality of stirring blades comprising a plurality of stirring blade sets arranged in a multistage manner, and the reaction The tank is divided into a plurality of small chambers arranged in a multi-stage by obstacles, each chamber is configured to include at least one stirring blade set, the agitator is operated to stir the entire reaction system in each chamber, While preventing the sedimentation of the catalyst suspended in the continuous aqueous phase, and re-dispersing the coalesced bubbles and oil droplets away from the stirring blade, the gas phase in the continuous aqueous phase was made into bubbles and oil. Maintaining the phases in the form of oil droplets, between two adjacent chambers separated by the obstacle,
According to a predetermined direction, the reaction system is allowed to flow from the first small chamber to the second small chamber, and at the same time, the reaction system is prevented from flowing backward in the above-mentioned direction, and the second small chamber is prevented. 8. The method according to any one of claims 1 to 7, wherein the reaction system of (1) is prevented from being mixed back with the reaction system of the first compartment. 15. The uppermost chamber among the small chambers has a reaction product outlet, and a weir is arranged near the reaction product outlet to provide a standing region, and the reaction mixture obtained is circular. 15. The method of claim 14, which facilitates separation into an oil phase as an upper layer containing olefins and an aqueous phase as a lower layer containing a hydrogenation catalyst. 16. The uppermost chamber includes the uppermost stirring blade set of the plurality of stirring blade sets, and the uppermost stirring blade set includes a gas-liquid free surface in a reaction tank when the stirring machine is operated. The method according to claim 14 or 15, wherein the gas is provided at a position higher than that in the reaction system, and the uppermost stirring blade set causes the gas to be included in the reaction system. 17. A reaction liquid mixture comprising a gas containing hydrogen gas and a liquid containing an oil phase and an aqueous phase is introduced into a gas-liquid separation tank provided outside the reactor to perform gas-liquid separation, and thus obtained. The above liquid was introduced into an oil-water separation tank to separate an oil phase as an upper layer containing a cyclic olefin from an aqueous phase as a lower layer containing water and a catalyst suspended therein, and then an upper oil phase was taken out. The method according to claim 14 or 16, wherein the lower aqueous phase is re-refluxed to the reactor.