JP2501210B2 - Method for producing cyclic alcohol - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel method for producing a cyclic alcohol by hydration of cyclic olefin. More specifically, the present invention relates to a method for producing a cyclic alcohol characterized by carrying out catalytic hydration using zeolite as a catalyst in a reaction system in which a cyclic conjugated diene is substantially absent.

[Conventional technology]

Conventionally, as a preferable method for producing an alcohol by a hydration reaction of olefin, a method using a zeolite such as crystalline aluminosilicate (for example, JP-B-47-45323).
No. 5, JP-B-53-15485, JP-A-57-70828, and JP-A-58.
-124723, JP-A-58-194828 and the like) are known.

[Problems to be solved by the invention]

The method using zeolite as the solid catalyst has the advantages that product alcohol can be easily separated and recovered, and that the material of the reactor is not particularly limited. However, as a result of various studies, the method using zeolite as a catalyst has been found to have a problem that the catalytic activity thereof decreases with time.

Therefore, when carrying out the hydration reaction of cyclic olefins, it is necessary to regenerate or newly replenish or replace the catalyst with reduced activity, which requires a large amount of cost and poses a problem when industrially carried out. is there.

[Means for solving problems]

The present inventors have conducted extensive studies to solve the problems when using the above zeolite as a catalyst, and by carrying out catalytic hydration in a reaction system in which a cyclic conjugated diene does not substantially exist, the catalyst They have found that the decrease in activity over time is significantly suppressed, and have completed the present invention.

That is, the present invention, when producing a cyclic alcohol by catalytic hydration of cyclic olefin using a zeolite as a catalyst, the production of cyclic alcohol characterized by carrying out catalytic hydration in a reaction system in which the cyclic conjugated diene is substantially absent. Is the way.

The reason why the decrease in the catalytic activity with time is markedly suppressed in the present invention as compared with the conventional method is not clear, but it is considered as follows.

As a result of the study by the present inventors, it was found that the cyclic olefin usually contains a cyclic conjugated diene. Cyclic olefins such as cyclohexene are commercially produced by dehydrohalogenation of chlorocyclohexane. The cyclohexene produced by such a production method contains a cyclic conjugated diene.

Further, according to the results of the study by the present inventor, it was found that the amount of cyclic conjugated diene contained in cyclohexene increased even during storage. The increase is particularly large when exposed to high temperature conditions. It has also been found that the contact with oxygen in the atmosphere gas also increases. Usually 500ppm in cyclohexene
˜Thousands of ppm, and possibly more, 1,3-cyclohexadiene.

It has not been known so far that such an important factor affecting the decrease in the activity of the hydration reaction catalyst over time is such a cyclic conjugated diene, which was first discovered by the present inventors. That is, in the conventional hydration reaction, the presence of the cyclic conjugated diene to the extent that it does not affect the yield of the product alcohol was overlooked as unnecessary removal. However, even with such a small amount of cyclic conjugated diene, a marked decrease in catalytic activity was observed when the hydration reaction was carried out for a long time using zeolite as a catalyst.

When performing a hydration reaction using a zeolite such as crystalline aluminosilicate as a catalyst, the reason for the decrease in the activity of the catalyst over time is due to the cyclic conjugated diene existing as an impurity in the raw material. The reason is that these cyclic conjugated dienes react on the acid sites of the zeolite, which is the active site of the hydration reaction, and the polymeric side reaction product produced is the acid sites of the catalyst.
That is, it is considered that it is irreversibly adsorbed on the active site of the hydration reaction, and as a result, the catalytic active site is covered and the activity is reduced. On the other hand, in the hydration reaction using a homogeneous catalyst, the above-mentioned polymeric side reaction product does not affect the catalytic activity even if it is produced, and is separated from the catalyst by an operation such as filtration or adsorption. Can be done easily and is not an essential problem.

Therefore, this effect is peculiar in the present invention in which zeolite, which is a solid catalyst, is used as a catalyst.

In the production method of the present invention, that is, when the catalytic hydration of cyclic olefin is carried out in the reaction system in which the cyclic conjugated diene is substantially absent, the above-mentioned phenomenon does not occur essentially, and therefore the activity of the catalyst is maintained for a long time. can do.

In the method of the present invention, zeolite such as crystalline aluminosilicate is used as a hydration catalyst. Examples of preferred zeolites include crystalline aluminosilicates such as mordenite, erionite, ferrierite, ZSM type zeolites announced by Mobil and zeolites containing different elements such as borosilicates. A more preferable zeolite is a ZSM type zeolite, and ZSM-5 is particularly preferable.

Further, the exchangeable cation species of the zeolite is usually a proton exchange type, Mg, Ca, alkaline earth elements such as Sr, La, rare earth elements such as Ce, Fe, Co, Ni, Ru, Pd,
It is also effective that it is exchanged with at least one cation species selected from Group VIII elements such as Pt. Or T
It is also effective to contain i, Zr, Hf, Cr, Mo, W and the like.

Further, the zeolite catalyst used in the method of the present invention may be in any form, for example, powdery or granular form can be used. Further, alumina, silica, titania or the like can be used as a carrier or a binder.

The cyclic olefin used in the present invention is preferably cyclopentene, methylcyclopentenes, cyclohexene, methylcyclohexenes, cyclooctene, cyclododecene and the like.

The cyclic conjugated diene in the present invention, for example, cyclopentadiene, methylcyclopentadiene 1,3-cyclohexadiene 1-methyl, 1,3-cyclohexadiene,
It refers to such things as 1,3-cyclooctadiene, 1,3-cyclododecadien and the like.

The reaction system in which the cyclic conjugated diene is substantially absent in the present invention may be a reaction system in which the activity reduction of the zeolite catalyst used in the present application due to the cyclic conjugated diene is sufficiently small to be neglected from an industrial viewpoint. It is already preferable that the amount of the cyclic conjugated diene present in the reaction system is smaller, but the substantial effect can be sufficiently achieved if the amount of the cyclic conjugated diene is reduced below a predetermined permissible concentration. The above 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. The cyclic conjugated diene is usually 200 ppm or less with respect to the cyclic olefin to be supplied,
It is preferably 100 ppm or less, more preferably 50 ppm or less.

Any method may be used as a method in which the cyclic conjugated diene or the like is not substantially present in the reaction system, but it is usually possible by using a raw material containing no cyclic conjugated diene, water, zeolite and an atmospheric gas. Is.

Examples of the method for removing from the cyclic olefin containing the cyclic conjugated diene include the following methods. (1)
Activated clay containing cyclic olefin containing cyclic conjugated diene,
A method of contacting with an adsorbent such as zeolite; (2) a method of separating and purifying a cyclic olefin containing a cyclic conjugated diene in a system substantially free of oxygen, in particular, an extractive distillation; A method of treating the contained cyclic olefin with a reducing agent such as hydrogen and exchanging the cyclic conjugated diene with the cyclic olefin or cyclic alkane, (4) hydrating catalyst such as zeolite with the cyclic olefin containing the cyclic conjugated diene in front It is a method of contacting and purifying.

However, it goes without saying that it is preferable to use a raw material that does not contain a cyclic conjugated diene from the beginning, since the above-mentioned removal step is unnecessary.

Further, it is not preferable to coexist a compound which gives a cyclic conjugated diene in the reaction system. For example, 1,3
3 as a compound that gives cyclohexadiene in the reaction system
-Hydroxycyclohexene, 4-hydroxycyclohexene and the like. The coexistence of such a compound in the reaction system has the same adverse effect as the coexistence of the cyclic conjugated diene.

The reaction is carried out by a commonly used method such as a fluidized bed system, a stirred batch system or a continuous system. From the equilibrium aspect of the hydration reaction of cyclic olefin, the reaction temperature is
And low temperature is advantageous in terms of increase in side reactions, etc.,
Since high temperature is advantageous from the viewpoint of reaction rate, in the present invention, the reaction temperature varies depending on the cyclic olefin used, but a range of 50 to 250 ° C. is usually used, preferably 60 to 200 ° C., Particularly, the range of 70 to 160 ° C is preferable. Also,
The reaction pressure is not particularly limited, and the cyclic olefin and water may exist as a gas phase, but it is convenient to exist as a liquid phase. The molar ratio of cyclic olefin and water as a raw material can be set in a wide range, and it also differs 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.
Therefore, in the present invention, for example, the molar ratio of cyclic olefin to water in a batch system is 0.01 to 10.
The range of 0 is preferable, and the range of 0.03 to 10 is particularly preferable.

When this reaction is carried out in a batch system, the weight ratio of the cyclic olefin and the catalyst is preferably 0.005 to 100, particularly 0.05 to 10
Is preferred. The reaction time is preferably in the range of 3 to 300 minutes, particularly preferably 10 to 180 minutes.

Further, it is convenient to use an inert gas such as nitrogen, hydrogen, helium, argon or carbon dioxide in addition to the reaction raw material cyclic olefin and water. In this case, the smaller the content of oxygen in the inert gas, the more preferable. Usually 100ppm
The following content is used, preferably 50 ppm or less, and more preferably 20 ppm or less. Further, aliphatic saturated hydrocarbons, aromatic hydrocarbons, oxygen-containing organic compounds, sulfur-containing organic compounds, halogen-containing organic compounds and the like may be present in the reaction system.

〔Example〕

The present invention will be specifically described below with reference to Examples and Comparative Examples.

Reference Example (Preparation of Catalyst) 1450 g of sodium silicate (water glass No. 3) was dissolved in 700 g of water (solution A), 104 g of aluminum sulfate and 35 g of concentrated sulfuric acid.
Was dissolved in 400 g of water (solution B), and 170 g of 1,3-dimethylurea was further dissolved in 800 g of water (solution C). The liquid A was mixed with the liquids B and C while stirring with a homogenizer. The obtained gel-like aqueous mixture was charged into a stainless steel autoclave with an internal volume of 5 l and equipped with a stirrer, and heated at 160 ° C. for 20 hours while stirring at a stirring peripheral speed of 1.5 m / sec. Separate the generated crystalline aluminosilicate with a centrifuge, wash with water, and
It was dried at 0 ° C. for 4 hours. Then 5 at 550 ° C under air flow
Burned for hours. Further, cation exchange was repeated three times with an aqueous solution of ammonium chloride 2M. After washing with water, filtration and drying,
It was calcined at 400 ° C. for 2 hours to obtain a proton exchange type crystalline aluminosilicate.

(Catalyst 1) Example 1 1 kg of cyclohexene (manufactured by Toray Industries, Inc.) along with 200 g of activated clay (manufactured by Japan Activated Clay Co., Ltd.) 120 in an autoclave
The mixture was heated and stirred at ℃. After cooling, pass in a nitrogen atmosphere,
Further, oxygen was sufficiently removed by a precision fractionating apparatus and atmospheric distillation was carried out to obtain a fraction (A) having a boiling point of 82 to 83 ° C. Untreated cyclohexene and treated cyclohexene (fraction A) were analyzed, and the contained 1,3-cyclohexadiene was quantified by gas chromatography. The results are shown in Table 1.

Next, using a continuous flow reactor as shown in the drawing,
Hydration reaction of cyclohexene was performed.

That is, 120 g of the catalyst prepared in Reference Example and 300 g of water were charged through a supply pipe 1 into a stainless steel autoclave reactor 3 with an internal volume of 1,000 ml equipped with a stirrer, and the system was replaced with nitrogen gas. The temperature in the reactor 3 was raised to a reaction temperature of 120 ° C. while stirring at a rotation speed of 600 rpm, and then cyclohexene (fraction A) was fed from the supply pipe 1 at a rate of 140 g / hr and the height of the liquid surface. The water is supplied from the supply pipe 2 so that the temperature becomes constant. The reaction mixture overflowing from the reactor 3 is introduced into the liquid-liquid separator 5 through the overflow pipe 4. The oil phase in the separated reaction mixture is taken out of the system through the discharge pipe 6, and the catalyst-water phase is recovered by the return pipe 7 into the reactor 3. The cyclohexanol concentration in the discharged oil was 12.8% by weight 3 hours after starting the supply of the starting material cyclohexene. Also, 230
The cyclohexanol concentration in the discharged oil after the passage of time is
It was 12.2% 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 cyclohexanol concentration in the discharged oil was 7.5% by weight 3 hours after starting the supply of the starting material cyclohexene. Again 9
The cyclohexanol concentration in the discharged oil after 6 hours is 1.5.
% By weight.

Examples 2-5, Comparative Example 2 The cyclohexene used in Example 1 was separately prepared 1,
Hydration reaction was carried out under the same reaction conditions as in Example 1 except that cyclohexene having the content shown in Table 2 was prepared by adding 3-cyclohexadiene and used as a raw material. Table 2 shows the cyclohexanol concentration in the discharged oil after 150 hours from the start of feeding the starting material cyclohexene.

(Effect of the invention) According to the present invention, in producing a cyclic alcohol by catalytic hydration of cyclic olefin, by performing catalytic hydration using zeolite as a catalyst in a reaction system in which a cyclic conjugated diene is substantially absent, Compared with the conventional method, the decrease in catalyst activity over time is significantly suppressed, and the activity lasts for a long time.

[Brief description of drawings]

The drawing shows the continuous flow reactor used in Examples and Comparative Examples. In the figure, 1 is a cyclohexene supply pipe, 2 is a water supply pipe, 3 is an autoclave reactor, 4 is an overflow pipe, 5 is a liquid-liquid separator, 6 is a discharge pipe, and 7 is a return pipe.

Claims (2)

(57) [Claims] 1. When producing a cyclic alcohol by catalytic hydration of a cyclic olefin using zeolite as a catalyst,
A method for producing a cyclic alcohol, which comprises carrying out catalytic hydration in a reaction system in which a cyclic conjugated diene is 200 ppm or less with respect to a cyclic olefin. 2. The cyclic olefin is cyclohexene,
The method according to claim 1, wherein the cyclic conjugated diene is 1,3-cyclohexadiene.