JPH09118638A - Production of cycloolefin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cycloolefin important as an intermediate for lactams, etc., in good selectivity by partially hydrogenating a monocyclic aromatic hydrocarbon in the presence of a catalyst having high activities. SOLUTION: A monocyclic aromatic hydrocarbon such as benzene is partially hydrogenated in the presence of a ruthenium catalyst and water containing a metallic salt such as cobalt sulfate to afford a cycloolefin such as cyclohexene. Furthermore, the ruthenium catalyst used in the reaction is obtained by preparing a catalytic precursor, then carrying out the reducing treatment thereof and supporting at least one cocatalyst metallic component, e.g. manganese on the resultant reduced ruthenium substance.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a process for producing a cyclohexene by partially hydrogenating a monocyclic aromatic hydrocarbon and correspondingly hydrogenating a corresponding cycloolefin, in particular, benzene. Cycloolefins, lactams, polyamide raw materials such as dicarboxylic acid, lysine, pharmaceuticals,
It is a compound useful as an important intermediate material such as pesticides.

[0002]

2. Description of the Related Art As a method for producing cycloolefin,
Many methods such as partial hydrogenation reaction of monocyclic aromatic hydrocarbons, dehydration reaction of cycloalkanol, dehydrogenation reaction of cycloalkane, and oxidative dehydrogenation reaction have been known.
Among them, if the cycloolefin can be efficiently obtained by the partial hydrogenation of the monocyclic aromatic hydrocarbon, the reaction step becomes the most simplified, which is preferable in the process.

As a method for producing a cycloolefin by partial hydrogenation of a monocyclic aromatic hydrocarbon, ruthenium metal is mainly used as a catalyst, and a hydrogenation reaction is generally performed in the presence of water. As the ruthenium catalyst, a method of using fine particles of metal ruthenium as it is (JP-A-61-61
-50930, JP-A-62-45541, JP-A-62-
45544), or a method using a catalyst in which ruthenium is supported on a carrier such as silica, alumina, barium sulfate, zirconium silicate (JP-A-53-63350, JP-A-57-130926, JP-A-61-61). 40226, JP-A-4-74141, etc.) have been proposed. In general, in the above reaction, the higher the reaction activity of the catalyst, the lower the selectivity of the obtained cycloolefin, so in such a reaction system, zinc sulfate, in the presence of a metal salt such as cobalt sulfate, It is said that a method of suppressing the reaction activity while maintaining high selectivity and yield of the corresponding cycloolefin is preferable.

[0004]

However, all the conventional methods have some problems, and an industrially advantageous method is not always established. In particular, the target cycloolefin selectivity is still insufficient.

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made detailed studies on the cocatalyst component of a ruthenium catalyst used in carrying out the partial hydrogenation reaction of a monocyclic aromatic hydrocarbon and the production process. The inventors of the present invention, in order to solve the above-mentioned problems, in particular, the results of a detailed study on the production process of the ruthenium catalyst used when carrying out the partial hydrogenation reaction of monocyclic aromatic hydrocarbons. As a method for further exhibiting the effect of the cocatalyst that is present together with ruthenium, it was found that the reaction results with the ruthenium catalyst obtained by the method of supporting the cocatalyst component after the conventional catalyst reduction step are remarkably improved, and the present invention was found. Arrived

That is, the gist of the present invention is to provide a catalyst precursor containing a ruthenium component in a method for producing a cycloolefin in which a monocyclic aromatic hydrocarbon is partially hydrogenated in the presence of a ruthenium catalyst and water. A method for producing a cycloolefin is characterized in that a ruthenium catalyst obtained by supporting at least one promoter metal component on a ruthenium reduced product obtained by subjecting a body to a reduction treatment is used.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. Examples of the raw material of ruthenium as the catalytically active component include ruthenium halides, nitrates, hydroxides, complex compounds such as ruthenium carbonyl and ruthenium ammine complexes, and ruthenium alkoxides. Among them, ruthenium chloride is preferably used.

In the present invention, the step of preparing a catalyst precursor containing a ruthenium component is a step exemplified by the alkaline precipitation method in the case of a non-supported catalyst, and a step of a carrier-supported catalyst precursor in the case of a carrier-supported catalyst precursor. This is a step of supporting a ruthenium raw material compound on a catalyst carrier. The catalyst precursor containing the ruthenium component is subjected to a reduction treatment to reduce the ruthenium component to be metallized and then used as a catalyst. As a method for preparing the unsupported catalyst precursor, a mixed solution of ruthenium and a compound of a desired promoter metal component may be used to obtain a solid by a general coprecipitation method such as an alkali precipitation method. Alternatively, it may be evaporated to dryness in the state of a homogeneous solution.

As the ruthenium catalyst, a non-supported type catalyst can be used. In general, however, a carrier-supported catalyst is preferable because the activity per catalyst component can be improved or the stability of the catalyst activity can be improved. The method of preparing the carrier-supported catalyst precursor, that is, the method of supporting the catalyst component on the carrier, after immersing the carrier in a catalyst component liquid, evaporating the solvent while stirring to immobilize the active component, evaporating to dryness method, Spray method of spraying the catalytically active component liquid while keeping the carrier in a dry state,
Alternatively, a known impregnation-supporting method such as a method of immersing the carrier in the catalytically active component liquid and then filtering the carrier is suitably used. Also,
As the solvent used for supporting the active ingredient at the time of catalyst preparation, water or an organic solvent such as alcohol, acetone, tetrahydrofuran, hexane or toluene is used. The supported amount of ruthenium is usually 0.001 to 10% by weight, preferably 0.1 to 5% by weight.

The carrier used for the above-mentioned carrier-supported catalyst may be silica, alumina, silica-alumina, zeolite, activated carbon, or a common metal oxide, composite oxide, hydroxide, poorly water-soluble metal salt. Etc. are exemplified. As the carrier, a poorly soluble oxide or metal salt generally used as a catalyst carrier is used. Specifically, barium sulfate, metal salts such as calcium sulfate, silica, alumina,
Zirconia, titania, chromina, oxides of rare earth metals, or composite oxides such as silica-alumina, silica-zirconia, zirconium silicate,
Examples thereof include silica modified with a metal oxide such as zirconia.

[0011] Among the above carriers, carriers having the following properties can be suitably used. When the pore volume and the pore distribution are measured by the mercury intrusion method, the pore diameter is 75 to 100,00.
The total pore volume of 0Å is 0.2 to 10 ml / g, preferably 0.3 to 5 ml / g, and the pore diameter is 75 to 1
With respect to the total pore volume of 0,000Å, the volume of pores having a diameter of 250 Å or more is usually 50% or more, preferably 70% or more.
% Of the carrier. Pore diameter is 250Å
If the ratio of the pores of less than 1 is too large, the selectivity tends to decrease, which is not preferable.

Of the above carriers, oxide carriers are generally preferred, and examples thereof include silica or a carrier obtained by modifying a silica carrier with a transition metal compound, particularly a carrier obtained by modifying zirconia to silica. . In this zirconia-modified silica carrier, the amount of zirconia that modifies the silica matrix is usually 0.1 to 20% by weight, preferably 0.5 to 10% by weight, based on the silica. As a method for preparing a silica carrier modified with zirconia, a solution in which a zirconium compound is dissolved in water or an organic solvent,
Alternatively, after dissolving the zirconium compound, using a solution obtained by partially or entirely hydrolyzing with an alkali or the like, supporting the silica on a silica by suitably using a known impregnation supporting method or a dip coating method, and then drying and firing. A method is used. Examples of the zirconium compound used here include zirconium halides, oxyhalides, nitrates, oxynitrates, hydroxides, complex compounds such as zirconium acetylacetonate complexes, zirconium alkoxides, and the like. The firing temperature here may be any temperature that is higher than the temperature at which the used zirconium compound becomes zirconia, and is usually 600 ° C. or higher, and particularly preferably 800 to 1200 ° C. However, if the temperature is higher than 1200 ° C. and fired at a higher temperature, the crystallization of silica becomes remarkable and the catalytic activity is lowered, which is not preferable.

The catalyst precursor containing the ruthenium component prepared as described above is usually used as a catalyst after reducing the ruthenium component to metallize it by subsequent reduction treatment. Before such reduction treatment,
The catalyst performance can be improved by performing the oxidation treatment or the heat treatment. The oxidation treatment method may be a general method, for example, a method of contacting an oxygen-containing gas with a catalyst precursor or a method of contacting with an oxidizing agent such as hydrogen peroxide. On the other hand, the heat treatment is usually 80
To 800 ° C., preferably 300 to 600 ° C., usually 0.1.
The catalyst precursor is retained for 1 to 50 hours, preferably 0.5 to 10 hours. The heat treatment is distinguished from the subsequent reduction treatment, and thus is performed in an oxidizing gas atmosphere or an inert gas atmosphere.

Further, when the catalytic oxidation with oxygen gas is carried out under heating, that is, in an oxygen-containing gas atmosphere, it is usually 8
In the case of calcination at 0 to 800 ° C., preferably 300 to 600 ° C., the above-mentioned oxidation treatment and heat treatment of the catalyst precursor are carried out at the same time, which is one of the preferred embodiments of the present invention. The reason why the selectivity of cycloolefin is improved by using the catalyst prepared by subjecting the catalyst precursor to oxidation treatment or heat treatment is not clear, but in the case of passing through the treatment, in the subsequent reduction treatment step. When an advantageous active site is generated when forming a metal ruthenium crystal, or when the treatment is carried out in the coexistence with a cocatalyst component, the existing form of ruthenium and the cocatalyst is a metal in the subsequent reduction treatment. It is presumed to generate advantageous active sites when forming a ruthenium crystal.

Next, as a method for reducing the above catalyst precursor, a catalytic reduction method using hydrogen gas or a chemical reduction method using formalin, sodium borohydride, hydrazine or the like is used. Of these, catalytic reduction with hydrogen gas is preferable, and reduction activation is carried out by firing in a hydrogen-containing gas atmosphere under conditions of usually 80 to 500 ° C., preferably 100 to 450 ° C. When the reduction temperature is lower than 80 ° C., the reduction ratio of ruthenium is remarkably reduced, and
If the temperature exceeds ℃, agglomeration of ruthenium is likely to occur, which causes a decrease in the yield and selectivity of cycloolefin production.

In the present invention, the catalyst obtained by the method described above is usually used as a catalyst. By subjecting such a catalyst to the water treatment described below, a catalyst having improved cycloolefin selectivity can be obtained. It is possible to obtain. The water treatment is carried out, for example, by immersing the catalyst (ruthenium reduced product) in water usually 0.01 to 100 times, preferably 0.1 to 10 times the weight of the above catalyst (ruthenium reduced product). The processing conditions are usually from room temperature to 250 ° C., preferably from room temperature to 200 ° C., under normal pressure to pressurization, usually at 10 ° C.
For at least one minute, preferably for 1 to 20 hours. The catalyst treatment atmosphere is usually an inert gas atmosphere or a hydrogen gas atmosphere, preferably a hydrogen gas atmosphere. Furthermore, the catalyst after the water contact treatment is usually dried, and then subjected to a re-reduction treatment, in particular, a contact treatment under a hydrogen gas atmosphere.
It becomes possible to obtain a ruthenium catalyst with higher activity.

The water used for the above contact treatment may be pure water or an aqueous solution containing a metal salt. Examples of the metal salt include Group 1 metals such as lithium, sodium and potassium, and 2 such as magnesium and calcium.
Examples thereof include nitrates, chlorides, sulfates, acetates and phosphates of group metals or metals such as zinc, iron, manganese and cobalt. The concentration of the metal salt in the aqueous solution is usually 1 × 10 ^-5 to 1 times by weight, preferably 1 × 10 ^-4
~ 0.2 times by weight. The catalyst after the contact treatment is usually used after filtering a metal salt aqueous solution, washing with pure water, and drying. Further, after the drying, the reduction treatment may be performed again in a hydrogen gas atmosphere or the like. When the ruthenium reduced product is treated with an aqueous solution containing a metal salt, a trace amount of the metal component may remain on the ruthenium reduced product even if it is washed with pure water. Such water treatment will be described below. It is usually carried out separately from the step of positively supporting the promoter metal component on the ruthenium reduced product.

The present invention is characterized in that in the preparation of the above ruthenium catalyst, the promoter metal component is added by a specific method. The promoter metal component is not particularly limited, but examples thereof include manganese, zinc, lanthanum, and elements of groups 8 to 11 (excluding ruthenium). Further, iron, cobalt, nickel, platinum, gold, silver, copper and the like are effective as the Group 8 to 11 elements, and gold, silver and copper are particularly preferable. As a raw material of the promoter metal component, a halide, nitrate, acetate, sulfate of each metal and a complex compound containing each metal are used. When a promoter metal is used, the atomic ratio of promoter metal to ruthenium atom is usually 0.01 to 20, preferably 0.1 to 10.

The present invention is characterized in that a ruthenium catalyst is prepared by preparing a ruthenium component-containing catalyst precursor, subjecting the catalyst precursor to a reduction treatment, and carrying a promoter metal component on the reduced ruthenium product. However, when a plurality of promoter metal components are used, at least one promoter metal component may be supported on the ruthenium reduced product. For example,
That is, when two types of zinc and copper are used as the cocatalyst metal component, the zinc compound is used in the step of preparing the ruthenium component-containing catalyst precursor to obtain a ruthenium reduced product also containing zinc, and then copper It is a method of supporting the components.

The method of supporting the cocatalyst metal component may be any method as described above in the preparation of the ruthenium component-containing catalyst precursor, and the method of impregnating the solution containing the cocatalyst metal component with the ruthenium reduced product. Is exemplified. Specifically, a solution containing a sublimable metal complex exemplified by the acetylacetonate complex is preferably used. In addition, it is desirable to carry out the reduction treatment again after supporting the promoter metal component.

The reason why the selectivity of cycloolefin is improved in the ruthenium catalyst obtained by such a method is not clear, but it is presumed as follows. On the surface of the ruthenium catalyst, there are active sites with very strong hydrogenation ability,
An undesired reaction (formation into cycloalkanes) occurs on the active site. By adding such a co-catalyst metal component to a ruthenium catalyst which has been reduced in advance, it is considered that such an unfavorable active site is modified and the hydrogenation ability is controlled to effectively produce a cycloolefin. There is. In addition, the cocatalyst metal component that is subjected to reduction in the presence of ruthenium in advance plays a role in forming the ruthenium crystal morphology suitable for this reaction in the process of producing a metal ruthenium crystal, while the cocatalyst metal to be carried later is used. It is believed that the components are primarily responsible for modifying the ruthenium surface.

The present invention is characterized by using the above-mentioned ruthenium catalyst, but in the case of carrying out the present invention, the monocyclic aromatic hydrocarbon as a reaction raw material is benzene, toluene,
Xylene and lower alkyl group-substituted benzenes having about 1 to 4 carbon atoms are exemplified. In addition, the reaction system of the present invention requires the presence of water. Although the amount of water varies depending on the reaction mode, it is generally 0.01 to 10 times by weight, preferably 0.1 to 5 times by weight of the monocyclic aromatic hydrocarbon. Under such a condition, an organic liquid phase (oil phase) containing raw materials and products as main components and a liquid phase containing water (water phase)
Will form a phase. When the ratio between the oil phase and the aqueous phase is extreme, it is difficult to form two phases, and liquid separation is difficult. Further, if the amount of water is too small or too large, the effect of the presence of water is reduced, and if the amount of water is too large, it is necessary to enlarge the reactor, which is not preferable.

Further, in the present invention, it is preferable that a metal salt is present in the reaction system. Types of metal salts include Group 1 metals such as lithium, sodium and potassium, Group 2 metals such as magnesium and calcium, and nitrates, chlorides, sulfates, acetates, phosphates of metals such as zinc, manganese and cobalt. Etc. are exemplified, and it is particularly preferable to use zinc sulfate or cobalt sulfate. The amount of metal salt used is
Usually, it is 1 × 10 ⁻⁵ to 1 times by weight, preferably 1 × 10 ^{−4 to} 0.1 times by weight of water in the reaction system.

As the reaction conditions of the present invention, the reaction temperature is
It is usually selected from the range of 50 to 250 ° C, preferably 100 to 220 ° C. If the temperature is 250 ° C or higher, the cycloolefin selectivity is lowered, and if it is 50 ° C or lower, the reaction rate is remarkably lowered, which is not preferable. The pressure of hydrogen during the reaction is usually 0.1 to 20 MPa, preferably 0.5 to 10 MPa.
It is selected from the range of MPa. If it exceeds 20 MPa, it is industrially disadvantageous. On the other hand, if it is less than 0.1 MPa, the reaction rate is remarkably reduced, which is uneconomical in terms of equipment. The reaction can be carried out in either a gas phase reaction or a liquid phase reaction, but is preferably a liquid phase reaction. The reaction system is not particularly limited, and it can be carried out batchwise or continuously using one or two or more reaction tanks.

[0025]

EXAMPLES Examples will be described below, but the present invention is not limited to these examples. The conversion rate and selectivity shown in Examples and Comparative Examples are defined by the following equations.

[0026]

(Equation 1)

[0027]

(Equation 2)

Example 1 (Production of carrier) Zirconium oxynitrate dihydrate 0.8
Silica (Fuji Silysia Chemical Ltd., trade name: CARIACT50) was added to an aqueous solution prepared by dissolving 7 g in 20 ml of pure water.
After adding 8.0 g and immersing at room temperature, water was distilled off and it was made to dry. Next, it was calcined at 1000 ° C. for 4 hours under air flow to prepare a silica carrier modified with 5% by weight of zirconia with respect to silica. The total pore volume of the carrier thus obtained having a pore diameter of 75 to 100,000Å is 0.75 ml.
/ G. Of these, the ratio of the volume of pores having a pore diameter of 250 Å or more was 96%.

(Preparation of Ruthenium Reduced Product) The above-mentioned zirconia-modified silica carrier was added to an aqueous solution containing a predetermined amount of ruthenium chloride and zinc chloride, and after dipping at 60 ° C. for 1 hour, water was distilled off and dried. By doing so, a catalyst precursor was obtained in which the ruthenium (Ru) component and the zinc (Zn) component were each loaded on the carrier in an amount of 0.5% by weight. A ruthenium reduced product was obtained by firing the above catalyst precursor in a hydrogen stream at 200 ° C. for 3 hours. (Preparation of catalyst supporting cocatalyst component (copper component)) The above ruthenium reduced product was added to a methanol solution containing copper acetylacetonate. After soaking at room temperature for 1 hour, methano-
Distilled off and dried to give copper (Cu) 0.05% to the carrier.
% Carried. This was reduced in a hydrogen stream at 200 ° C. for 3 hours to obtain a catalyst.

(Partial hydrogenation reaction of benzene) Next, in an autoclave made of Ti having an internal volume of 500 ml, 150 ml of an aqueous solution containing 0.1% by weight of cobalt sulfate, 2.0 g of the above catalyst,
100 ml of benzene was charged. Hydrogen gas was supplied at a flow rate of 57 Nl / Hr under conditions of a reaction temperature of 150 ° C. and a pressure of 50 MPa, and stirring was performed at 1000 rpm to carry out a partial hydrogenation reaction of benzene. The reaction liquid was appropriately extracted from the nozzle installed in the reactor, and the oil phase was analyzed by gas chromatography. The reaction results are shown in Table 1. Although the benzene conversion rate increases with time, the target cyclohexene selectivity tends to decrease.

Example 2 A benzene partial hydrogenation reaction was carried out in the same manner as in Example 1 except that a catalyst having a supported amount of copper of 0.1% was used. The reaction results are shown in Table 1. Comparative Example 1 Using the ruthenium reduced product of Example 1 as a catalyst as it was, a partial hydrogenation reaction of benzene was carried out under the same conditions as in Example 1. The reaction results are shown in Table 1. It can be seen that the cyclohexene selectivity is lower than that of Example 1 when compared with Examples 1 and 2 at the same degree of benzene conversion.

[0032]

[Table 1]

Example 3 Zinc sulfate 6 was added to a Ti autoclave having an internal volume of 500 ml.
% Aqueous solution (200 ml) and a ruthenium reduced product (10 g) obtained in the same manner as in Example 1 were charged. Temperature 200 ℃, pressure 5
Hydrogen gas was supplied at a flow rate of 57 Nl / Hr under the condition of 0 MPa, and the catalyst was treated by stirring at 600 rpm. 5
Time processed. After the treatment, the catalyst was taken out and washed with pure water. Washing was performed by adding 30 times the amount of pure water to the catalyst and mixing them sufficiently for 1 hour with stirring, etc., until the zinc concentration in the wash water at the time of substantially equilibrium became 0.1 ppm or less. Furthermore, after drying, it was kept at 200 ° C. in a hydrogen stream for 3 hours. To this, copper was added in an amount of 0.1 by the same method as in Example 1.
Supported by weight% and reduced. A partial hydrogenation reaction of benzene was carried out under the same conditions as in Example 1 except that the above catalyst was used. The reaction results are shown in Table-2.

Example 4 A ruthenium reduced product was obtained in the same manner as in Example 1, except that the catalyst precursor was calcined in an air stream at 500 ° C. for 2 hours and then reduced. The ruthenium reduced product was treated by the method described in Example 3 to carry 0.1% by weight of copper and reduce the copper. A partial hydrogenation reaction of benzene was carried out under the same conditions as in Example 1 except that the above catalyst was used. The reaction results are shown in Table-2.

[0035]

[Table 2]

[0036]

According to the present invention, in the partial hydrogenation of monocyclic aromatic hydrocarbons, the activity of the catalyst is high and cycloolefins can be obtained with high selectivity.

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Claims (6)

[Claims] 1. A method for producing a cycloolefin in which a monocyclic aromatic hydrocarbon is partially hydrogenated in the presence of a ruthenium catalyst and water, a ruthenium component-containing catalyst precursor is prepared,
A method for producing a cycloolefin, comprising using a ruthenium catalyst obtained by supporting at least one promoter metal component on a ruthenium reduced product obtained by reducing the catalyst precursor. 2. The method according to claim 1, wherein the catalyst precursor is subjected to oxidation treatment or calcination treatment and then reduction treatment. 3. The method according to claim 1, wherein the reduced ruthenium product is treated with water, and then a promoter metal component is supported. 4. The method according to claim 1, wherein a ruthenium catalyst obtained by carrying a re-reduction treatment after carrying a promoter metal component on the reduced ruthenium product is used. 5. The cocatalyst metal component supported on the reduced product of ruthenium is at least one selected from manganese, zinc, lanthanum, and elements of groups 8 to 11 (excluding ruthenium). To any one of 4 to 4. 6. The monocyclic aromatic hydrocarbon is partially hydrogenated in the presence of water containing a metal salt.
5 to any one of the methods.