JPH07179382A - Production of cyclic alcohol - Google Patents

Abstract

PURPOSE:To remarkably prolong the life of a catalyst in the catalytic hydration reaction of a cycloolefin to enable the stable production of a cyclic alcohol over a long period. CONSTITUTION:This process for the production of a cyclic alcohol comprises the catalytic hydration of a cycloolefin in the presence of a zeolite as a catalyst using a cycloolefin having a conjugated ketone content of <=200ppm as a raw material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a cyclic alcohol by hydrating a cyclic olefin. More specifically, the present invention relates to a method for producing a cyclic alcohol, which is capable of significantly improving the separability of a catalyst and is stable over a long period of time.

[0002]

2. Description of the Related Art Conventionally, as a preferred method for producing an alcohol by hydration of an olefin, a method using a zeolite such as crystalline aluminosilicate (Japanese Patent Publication No.
45323, JP-B-53-15485, JP-A-57.
-70828, JP-A-58-124723, JP-A-58-194828, etc.), and a method using a zeolite such as crystalline metallosilicate (JP-A-1110639).
Etc.) are known.

[0003]

A method of suspending zeolite as a solid catalyst in water and adding a cyclic olefin thereto to carry out a hydration reaction is a method of separating an oil phase and an aqueous phase after the reaction to obtain a target substance. Since the cyclic alcohol and the catalyst can be separated, it is simple and industrially advantageous.
However, as a result of detailed examination of the method using zeolite as a catalyst, it was found that there is a problem that the catalytic activity gradually decreases when the reaction is carried out for a long time. Therefore, when the hydration reaction of the cyclic olefin is carried out, it is necessary to regenerate or newly replenish or replace the catalyst with lowered activity, which requires a great deal of cost and is a problem in the case of industrial implementation. There is.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the problems when the above-mentioned zeolite is used as a catalyst, and as a result, the content of conjugated ketones as a cyclic olefin as a raw material is The present invention has been completed by finding that the reduction of the activity of the catalyst caused by the reaction for a long time is remarkably suppressed by carrying out the hydration reaction using a fixed amount or less of the cyclic olefin.

That is, the present invention is a method for producing a cyclic alcohol by catalytic hydration of a cyclic olefin using zeolite as a catalyst, wherein the cyclic olefin having a content of conjugated ketones of 200 ppm or less is used as a starting material. The present invention relates to a method for producing a cyclic alcohol, which is characterized by carrying out summation. Hereinafter, the present invention will be described in detail.

Preferred examples of zeolites that can be used in the present invention include mordenite, erionite,
Crystalline aluminosilicates such as ferrierite and ZSM-based zeolites announced by Mobil, and zeolites such as metalloaluminosilicates and metallosilicates containing foreign elements such as boron, iron, gallium, titanium, copper and silver. Is. In addition, the exchangeable cation species of zeolite is
Proton exchange type (H type) is usually used, but Mg, C
It is also effective to exchange with at least one cation species of alkaline earth elements such as a and Sr, rare earth elements such as La and Ce, and group VIII elements such as Fe, Co, Ni, Ru, Pd, and Pt. . Or Ti, Zr, Hf, Cr, M
It is also effective to contain o, W, Th and the like.

The cyclic olefin as a raw material used in the present invention includes cyclopentene, methylcyclopentenes,
Examples thereof include cyclohexene, methylcyclohexenes, cyclooctene, cyclododecene and the like. The present invention is achieved by setting the conjugated ketones in the above-mentioned raw material cyclic olefin to be below the allowable concentration. The permissible concentration varies depending on the type of cyclic olefin used as a raw material, the type of catalyst used, and the conditions of the hydration reaction, but as a guideline for carrying out, it is 200 ppm or less, preferably 1 ppm.
It is at most 00 ppm, more preferably at most 50 ppm.

In the present invention, the conjugated ketones refer to compounds having a carbonyl group and an unsaturated bond adjacent to the carbonyl group in the molecule, such as 2-cyclopenten-1-one,
2-cyclohexen-1-one (hereinafter sometimes abbreviated as “cyclohexanone”), 2-cyclooctene-1
Examples thereof include cyclic conjugated ketones such as -one and 2-cyclododecen-1-one, and chain conjugated ketones corresponding to them.

According to the studies by the present inventors, it has been found that the cyclic olefin usually contains a considerable amount of conjugated ketones. For example, cyclohexene is commercially produced mainly by dehydrohalogenation of chlorocyclohexane, but cyclohexene produced by such a production method contains a large amount of cyclohexenone as a conjugated ketone. There is. The cyclohexenone has also been confirmed to increase during storage. Cyclohexene usually contains cyclohexenone in an amount of 500 to several thousand ppm, and in some cases, more than that.

Therefore, it is usually necessary to keep the concentration of the conjugated ketones in the cyclic olefin below the allowable concentration. This method is not particularly limited and any method may be used, but a method of removing the conjugated ketones from the cyclic olefin by distillation, chromatography or the like can be exemplified. It has not been known so far that such an important factor affecting the decrease in the activity of the hydration reaction catalyst is such a conjugated ketone, and it was first discovered by the present inventors.
That is, in the conventional hydration reaction, it was overlooked that further removal of the conjugated ketones, which does not affect the yield of the product alcohol, was unnecessary. However, even with such a small amount of conjugated ketones, when zeolite is used as a catalyst and the hydration reaction is carried out for a long time, a marked decrease in the activity of the catalyst is observed.

Although the reason for the decrease in the activity of the zeolite catalyst with time is not clear, a polymeric side reaction product is formed by the reaction of the conjugated ketones on the acid sites of the zeolite, which is the active site of the hydration reaction. It is considered that the substance irreversibly adsorbs on the acid site of the catalyst, that is, the active site of the hydration reaction, and as a result, covers the catalytic active site and reduces the activity. On the other hand, in the hydration reaction using a homogeneous catalyst, the above polymeric by-products do not affect the catalytic activity even if they are produced, and they can be easily separated from the catalyst by operations such as filtration and adsorption. It is possible to do it, and it does not become an essential problem. Therefore, the effect of the present invention is presumed to be an effect peculiar to zeolite which is a solid catalyst.

The hydration reaction in the present invention is carried out in a commonly used format such as a batch system or a continuous system. Regarding the reaction temperature, a low temperature is advantageous in terms of equilibrium of the hydration reaction of the cyclic olefin and an increase in side reactions, but a high temperature is advantageous in terms of reaction rate. Is usually 50 to 250 ° C., preferably 60 to 200 ° C., and particularly preferably 70 to 160 ° C., though it depends on the cyclic olefin used. The reaction pressure is not particularly limited, and the cyclic olefin and water may exist as a gas phase, but preferably exist as a liquid phase.

The molar ratio of the starting cyclic olefin and water is selected from a wide range and varies depending on whether the reaction system is a continuous system or a batch system. However, when the cyclic olefin or water is in a large excess as compared with other raw materials, the reaction rate decreases, which is not practical. Thus, for example, in the case of cyclohexene, the molar ratio of cyclic olefin to water in the reactor is usually 0.01-10.
It is 0, preferably 0.03 to 10. The weight ratio of cyclic olefin to catalyst in the reactor is usually 0.005.
-100, preferably 0.05-10. further,
The reaction time or residence time is usually 3 to 300 minutes, preferably 10 to 180 minutes.

In addition to the reaction starting material cyclic olefin and water, it is preferable to use an inert gas such as nitrogen, hydrogen, helium, argon or carbon dioxide in the reaction system. In this case, it is desirable that the content of oxygen in the inert gas is small, and the content of oxygen is usually 100 ppm or less, preferably 50 ppm or less, more preferably 20 ppm or less. In addition, aliphatic hydrocarbons, aromatic hydrocarbons,
An oxygen-containing organic compound, a sulfur-containing organic compound, a halogen-containing organic compound and the like may coexist in the reaction system.

[0015]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. Example 1 10 kg of cyclohexene (manufactured by Aldrich Co.) was subjected to atmospheric distillation while sufficiently removing oxygen with a precision fractionator to obtain a fraction having a boiling point of 82 to 83 ° C. The untreated cyclohexene and the fraction were analyzed, and the contained cyclohexenone was quantified by gas chromatography. The results are shown in Table-1.

[0016]

[Table 1]

Next, the hydration reaction of cyclohexene was carried out using a continuous flow reactor as shown in FIG. That is, an H-type gallosilicate (MFI) was placed in a stainless steel autoclave reactor 3 having an internal volume of 2000 ml and equipped with a stirrer.
Type, made by NE Chemcat, silica / Ga ₂ O ₃ ratio = 50)
100 g and 250 g of water were charged, and the system was replaced with nitrogen gas. The temperature inside the reactor 3 was raised to a reaction temperature of 120 ° C. while stirring at a rotation speed of 500 rpm, and then cyclohexene (fraction) was supplied from the supply pipe 1 at a rate of 120 g / hr. The reaction liquid is separated into an oil phase and a catalyst slurry-water phase in a liquid-liquid separator 4 having an internal volume of 30 ml installed inside the reactor, and then only the oil phase is discharged from the overflow pipe 5. . In addition, the water and the overwater consumed in the hydration reaction are supplied from the supply pipe 2.
The amount of water in the reactor 3 was kept constant by supplying the total amount of water flowing out from the flow tube 5 as the amount of solubility in the oil phase. The cyclohexanol concentration in the spilled oil was 10.5% by weight 5 hours after starting the supply of the starting material cyclohexene. The cyclohexanol concentration in the spilled oil after 250 hours was 9.9% by weight.

Comparative Example 1 A hydration reaction was carried out under the same reaction conditions as in Example 1 except that the above-mentioned reagent cyclohexene was used as a raw material. The concentration of cyclohexanol in the spilled oil was 9.5% by weight 5 hours after starting the supply of the starting material cyclohexene. The concentration of cyclohexanol in the oil spilled after 50 hours was 4.2% by weight.

Example 2 H-replaceable crystalline aluminosilicate prepared by the method described in Reference Example of JP-A-63-250334 as a catalyst.
The hydration reaction was performed under the same reaction conditions as in Example 1 except that The concentration of cyclohexanol in the spilled oil 5 hours after the start of feeding the starting material cyclohexene was 11.7% by weight. The cyclohexanol concentration in the oil spilled after 250 hours was 10.9% by weight.

Comparative Example 2 A hydration reaction was carried out under the same reaction conditions as in Example 2 except that the above-mentioned reagent cyclohexene was used as a raw material. The cyclohexanol concentration in the spilled oil was 8.8% by weight 5 hours after starting the supply of the starting material cyclohexene. The concentration of cyclohexanol in the spilled oil after 50 hours was 3.6% by weight.

Examples 3 to 6 and Comparative Example 3 Cyclohexenone (reagent, manufactured by Wako Pure Chemical Industries, Ltd.) was added to the cyclohexene used in Example 1 to prepare cyclohexene having the content shown in Table 2 and used as a raw material. Is Example 1
The hydration reaction was carried out under the same reaction conditions as above. Table 2 shows the cyclohexanol concentration in the spilled oil after 100 hours from the start of supplying the starting material cyclohexene.

[0022]

[Table 2]

[0023]

Industrial Applicability According to the present invention, the life of the catalyst is significantly improved, so that the cyclic alcohol can be stably produced for a long period of time by catalytic hydration of the cyclic olefin.

[Brief description of drawings]

FIG. 1 is a continuous flow reactor used in Examples and Comparative Examples.

[Explanation of symbols]

1, cyclohexene supply pipe, 2, water supply pipe, 3, autoclave reactor, 4, liquid-liquid separator, 5, overflow
tube

Claims (2)

[Claims] 1. A method for producing a cyclic alcohol by catalytic hydration of a cyclic olefin using zeolite as a catalyst, wherein the catalytic hydration is carried out using a cyclic olefin having a content of conjugated ketones of 200 ppm or less as a raw material. A method for producing a cyclic alcohol, comprising: 2. The method according to claim 1, wherein the cyclic olefin is cyclohexene and the conjugated ketone is 2-cyclohexen-1-one.