JPH0920701A - Hydration of olefin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out a hydration reaction of an olefin while the deactivation of the catalyst is markedly restrained. SOLUTION: In the olefin hydration process comprising the hydration procedure which an olefin is hydrated, the removal procedure where the organic substance adhering to the zeolite catalyst is removed, and the catalyst-feeding procedure where the catalyst has undergone the removal of the organic substance is fed back to the hydration procedure, at least a part of the zeolite catalyst is extracted out of the hydration or removal procedure and the catalyst is brought into contact with a compound of the formula: NR<1> R<2> R<3> (R<1> , R<2> , R<3> are each H, a 1-4C alkyl group or amino group), then subjected to ion exchange and fed back to the hydration procedure or the catalyst removal procedure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of hydration reaction of olefins for producing alcohols important as various chemical raw materials.

[0002]

BACKGROUND OF THE INVENTION Hydration of olefins is a method of producing the corresponding alcohols from olefins and water. In the olefin hydration reaction using zeolite as a catalyst,
As the reaction progresses, organic substances mainly accumulate on the catalyst, so that the activity of the catalyst decreases. The catalyst with reduced activity is regenerated by removing the organic substances attached to the catalyst, and is used again for the olefin hydration reaction. As a method for removing the organic matter attached to the catalyst, a method of contacting with a gas containing molecular oxygen at a high temperature (Japanese Patent Publication No. 3-2015), a method of contacting with an inorganic acid, an inorganic alkali or an oxidizing agent in a liquid phase (Japanese Patent Publication No. 3-2014, Japanese Patent Laid-Open No. 3-224632, Japanese Patent Laid-Open No. 3-224633) and the like are known.

[0003]

However, in the olefin hydration reaction method in which the hydration reaction and the regeneration of the catalyst by the removal of organic substances are repeated, there is a problem that the catalyst activity gradually decreases with repeated regeneration.

[0004]

Means for Solving the Problems The inventors of the present invention have made extensive studies in view of the above problems, and as a result of repeating the hydration reaction and removal of organic substances, contact a catalyst with reduced activity with a specific compound, Then, by removing the cation species introduced from a specific compound by an ion exchange treatment and converting the cation species into a desired cation species, a decrease in the activity of the catalyst is suppressed,
We found that alcohol can be produced stably over the long term,
The present invention has been completed.

That is, the gist of the present invention is to hydrate a olefin in the presence of a zeolite catalyst, to remove an organic substance attached to the zeolite catalyst used in the hydration step, and to remove the catalyst through the removal step. In the olefin hydration method having a supply step of supplying the zeolite catalyst to the hydration step, at least a part of the zeolite catalyst is extracted from the hydration step or the removal step, and the zeolite catalyst is a compound represented by the following general formula (I): A method of hydrating an olefin, which comprises contacting, then ion-exchanging, and returning to the hydration step or the removal step.

[0006]

## STR00002 ## NR ¹ R ² R ³ (I) (wherein R ¹ , R ² and R ³ are a hydrogen atom or a carbon number of 1 to 1).
4 represents an alkyl group or an amino group. Hereinafter, the present invention will be described in detail.

In the present invention, the zeolite catalyst used as the catalyst for the olefin hydration reaction is not particularly limited as long as it is a zeolite that can be used as the catalyst.
Mordenite, erionite, ferrierite, ZSM
-5, ZSM-11, and other crystalline aluminosilicates such as ZSM-based zeolites announced by Mobil, or metallosilicates such as borosilicate, gallosilicate, and ferrosilicate, boroaluminosilicate, galloaluminosilicate, and aluminometallo such as ferroaluminosilicate. Known zeolites such as zeolites containing different elements such as silicates can be exemplified. In addition, these zeolite catalysts,
Usually, a proton exchange type (H type) is used, but a part of it is an alkaline earth element such as Mg, Ca or Sr, La or C.
rare earth elements such as e, Fe, Co, Ni, Ru, Pd, P
It may be exchanged with at least one kind of cation species selected from the group III elements such as t. Or Ti, Zr, H
It may contain f, Cr, Mo, W, Th, Cu, Ag and the like. The zeolite may be in any form, including powder and granules. Alumina, silica, titania, clay compounds and the like may be used as the carrier or binder.

The olefin used as a reaction raw material is usually a straight-chain or branched olefin having 2 to 12 carbon atoms such as propylene and butene, cyclopentene, methylcyclopentenes, cyclohexene, cyclooctene and the like having 5 to 5 carbon atoms. There are 12 cyclic olefins, preferably cyclic olefins.

The hydration conditions for the olefin are not particularly limited as long as the catalyst is present in the aqueous phase, the oil phase or the liquid phase consisting of a mixed phase of the two, the reaction temperature and the reaction pressure. The reaction temperature is usually 50 to 250 ° C., and when the olefin is a cyclic olefin, 100 to 200 ° C. is preferable.
The reaction may be carried out batchwise or continuously, but is preferably continuous. The molar ratio of olefin to water in the reaction system is usually 0.01 to 100, preferably 0.03 to 10. The weight ratio of the catalyst to the olefin in the reaction system is usually 0.005 to
It is 100, preferably 0.05 to 10. The residence time of the olefin during the reaction is usually 3 to 300 minutes, preferably 10 to 180 minutes.

The olefin hydration reaction system is preferably replaced with an inert gas such as nitrogen, hydrogen, helium, argon or carbon dioxide. Furthermore, in addition to olefin and water which are reaction raw materials, ethanol, acetone,
Reaction system of aliphatic hydrocarbons such as acetic acid, benzoic acid, cyclohexane, benzene, phenol, fluorobenzoic acid, sulfolane and their derivatives, aromatic hydrocarbons, oxygen-containing organic compounds, sulfur-containing organic compounds, halogen-containing organic compounds, etc. You may coexist in the inside.

An example of a method for separating the reaction liquid into an aqueous phase and an oil phase is a method in which an oil / water separation weir is provided in the reactor to take out only the oil phase. It is also conceivable to take out a part of the reaction liquid with a liquid circulation pump and supply it to an oil / water separation tank provided outside the reactor to separate it.The separated aqueous phase containing the catalyst circulates in the reactor. Can be reused. The alcohol can be easily purified and recovered from the separated oil phase by a known method such as distillation. Further, the residual liquid containing the olefin after the alcohol is separated by distillation or the like can be reused as a raw material for the hydration reaction.

As described above, the zeolite catalyst used in the hydration step has its catalytic activity gradually decreased due to the attachment of organic substances on the catalyst as the hydration reaction progresses. A part or all of the zeolite catalyst whose activity has decreased with the progress of the hydration reaction is extracted from the hydration step, and the catalytic activity is recovered by the removal step of removing the organic matter attached to the surface. The catalyst extracted from the hydration step may be washed with water or dried prior to the removal step.

The removal of organic substances adhering to the surface of the zeolite catalyst is carried out by a conventionally known method. For example, a gas phase heat treatment such as a method of contacting a gas containing molecular oxygen at high temperature (Japanese Patent Publication No. 3-2015),
Method of contacting with an inorganic acid, an inorganic alkali or an oxidizing agent in a liquid phase (Japanese Patent Publication No. 3-2014, JP-A-3-22)
4632, JP-A-3-224633) and the like.

The vapor phase heat treatment is carried out by removing from the hydration step.
The produced zeolite catalyst is treated with a gas containing molecular oxygen.
A method of contacting at high temperature can be mentioned. For example, the following
Done in a way. As a heating device, a general tubular furnace,
It may be of any type such as a muffle furnace, and is compatible with the gas distribution method.
The fixed bed or fluidized bed type can be operated in contact with gas.
What can be done is preferable. Gas acid containing molecular oxygen
The elementary concentration is usually 0.01 to 90 mol%, preferably 1 to
It is 30 mol%. As a gas component other than molecular oxygen
Is usually nitrogen, helium, argon, etc.
It is desirable that the water content in the soot be removed beforehand. Also,
In the case of the gas flow method, the gas flow rate depends on the zeolite catalyst.
Expressed in weight hourly space velocity (WHSV), usually 0.25
~ 50 hr ^-1Done in The conditions for vapor phase heat treatment are contact
The temperature is usually 200 to 600 ° C., and the contact time is usually 1 to 10
It is 0 hours, preferably 2 to 20 hours. Gas phase heat treatment
Can be either constant temperature treatment or variable temperature treatment.
Variable processing is preferred. Especially divided into low temperature treatment and high temperature treatment
The temperature variable treatment performed as described above is preferable.

For example, in the temperature variable treatment which is divided into a low temperature treatment and a high temperature treatment, the low temperature treatment is performed at a temperature of 80 ° C. or higher in the atmosphere of a gas containing molecular oxygen or a gas containing no oxygen under the above conditions. The heat treatment is performed at a treatment temperature of preferably 90 ° C. or higher and 350 ° C. or lower, preferably 300 ° C. or lower for 30 minutes or longer, preferably 60 minutes or longer. As the high temperature treatment, a gas containing molecular oxygen and usually 400 ° C. or higher, preferably 450 ° C. or higher, and
Usually at a treatment temperature of 600 ° C. or lower, usually for 1 to 100 hours,
The contact is preferably carried out for 2 to 20 hours.

As the liquid phase treatment, for example, a method of contacting with an oxidizing agent in the liquid phase can be mentioned. In particular,
It is carried out by allowing the zeolite catalyst extracted from the hydration step and the oxidizing agent to exist in the same liquid phase. Examples of the oxidant include hydrogen peroxide and ozone. The amount of the oxidant used varies depending on the state of decrease in catalyst activity, but it is usually 0.01 to 20 in terms of the weight of the oxidant with respect to the catalyst. The concentration of the oxidizing agent is usually 0.001 to 70% by weight, preferably 0.1 to 40% by weight, based on the liquid phase excluding the zeolite catalyst. The contact temperature between the zeolite catalyst and the oxidizing agent is usually 0 to 100 ° C. Also,
The contact time varies depending on the contact temperature, the concentration of the oxidizing agent, etc., but is usually about 15 minutes to 50 hours. The pH of the liquid phase is
A pH that does not cause structural change or structural destruction of zeolite is desirable. Usually, pH is 13 or less, and a polar solvent such as water is used as the liquid constituting the liquid phase.

When the zeolite catalyst and the oxidizing agent are brought into contact with each other under alkaline conditions, the zeolite catalyst is preferably washed with an acid after the contact with the oxidizing agent. In addition, prior to contacting with an oxidizing agent, a cation in the zeolite catalyst is ion-exchanged with an alkali metal in advance, then contacted with an oxidizing agent, and then ion-exchanged again to remove the alkali metal from the zeolite catalyst. Is also effective. After the above liquid phase treatment, the zeolite catalyst may be washed and dried with water or a polar organic solvent.

By the removal step for removing the organic substances attached to the zeolite catalyst, the activity of the zeolite catalyst can be almost recovered. The catalyst that has undergone the removal step is partially or wholly supplied to the hydration step and used again as a hydration catalyst. However, if the hydration step and the removal step are repeated several times, the activity of the zeolite catalyst will not gradually recover even if the removal step is performed.

It is presumed that organic substances, which are difficult to remove even after repeated removal steps, gradually accumulate. In addition, even if the organic substance or its decomposition product interacts with the active site of the catalyst due to contact with an oxidizing agent, a part of the structure of the zeolite is altered, and even if the organic substance itself can be removed, it still functions as a catalyst. It is possible that some of the effective active sites are lost.

In the present invention, as described above, the hydration step,
By repeating the removal step and the supply step, at least a part of the zeolite catalyst whose activity has not been sufficiently recovered is extracted from the hydration step or the removal step and brought into contact with the compound represented by the general formula (I), Then, the cation species derived from the compound represented by the general formula (I) introduced into the zeolite is ion-exchanged to reactivate the zeolite catalyst.

The reason why the activity is recovered by contact with the compound represented by the general formula (I) is not clear, but contact with the compound represented by the general formula (I) restores the altered acid sites. It is considered that the acid sites, which are active sites, are modified by such functions as returning the aluminum or the like in the desorbed zeolite to the lattice skeleton or removing it. In addition, when the catalyst is regenerated by contacting with the compound represented by the general formula (I) without performing the organic substance removal step, even if the acid sites of the zeolite catalyst can be activated, the organic substances attached to the zeolite catalyst When the regeneration is repeated, it is difficult to suppress the decrease in the catalytic activity, for example, because it cannot be removed sufficiently.

The removing step is performed more frequently than the step of contacting with the compound represented by the general formula (I). For example, when the catalyst is continuously withdrawn, the activity of the catalyst in the reaction step can be kept constant at all times, and therefore a certain amount of the catalyst withdrawn from the reaction step or the removal step is always expressed by the general formula (I). It is desirable that the compound is subjected to the step of contacting with the compound represented by. In this case, the ratio of the catalyst to be subjected to the step of contacting with the compound represented by the general formula (I) is appropriately set depending on the productivity and economic efficiency of the reaction, and further, the hydration reaction conditions, the amount of organic substances attached to the catalyst, etc. Depending on the total amount of the catalyst extracted from the reaction step or the removal step, it is usually 0.1% or more, preferably 1% or more, and usually 99% or less, preferably 95% or less. . In addition, the activity of the zeolite catalyst after the removal step is usually 40% or more, preferably 50% or more, and usually 99% of the activity of the catalyst when the catalyst is used for the first time.
%, Preferably below 95%, it is desirable to contact the zeolite catalyst with the compound of general formula (I).

[0023]

[Image Omitted] NR ¹ R ² R ³ (I)

In the general formula (I), R ¹ , R ² and R ³ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an amino group, preferably a hydrogen atom or an amino group, and particularly preferably R. ^{1 to} R ³ each represent a hydrogen atom. Specific examples include ammonia, hydrazine, methylamine, ethylamine, dimethylamine, trimethylamine, propylamine, isopropylamine and triethylamine. When the ion exchange is carried out by a gas phase heat treatment, a compound containing less carbon atoms is preferable, and ammonia is preferable in order to reduce coking during firing. The compound represented by the general formula (I) may be in any form, and typically includes gas, liquid, solution and the like.

The amount of the compound represented by the general formula (I) used varies depending on the level of deterioration of the zeolite catalyst.
The amount is usually 0.0001 to 10 times by weight, preferably 0.0005 to 5 times by weight, and more preferably 0.001 to 10 times by weight that of zeolite. Contact temperature is usually 20
-200 degreeC, Preferably it is 40-160 degreeC. The contact time varies depending on the level of deterioration of the zeolite catalyst, the contact temperature, etc., but is usually 1 minute to 20 hours, preferably 15 minutes to 10 hours. The contact method may be a fixed bed or a slurry state. Stirring in a slurry state is preferable because uniform contact can be achieved.

The zeolite catalyst contacted with the compound represented by the general formula (I) is ion-exchanged with a cationic species derived from the compound represented by the general formula (I). This cationic species introduced into the zeolite catalyst is used for the hydration reaction of the olefin after ion conversion into the desired cationic species. Prior to ion-exchange of the cation species derived from the compound represented by formula (I), washing and drying may be performed.

The cation species exchanged with the cation species derived from the compound represented by the general formula (I) introduced into the zeolite catalyst are usually selected from protons, alkaline earth elements, rare earth elements and Group VIII elements. At least one cationic species is used. The method of ion exchange is not particularly limited, but depends on the cation species after ion exchange, and when the cation species is a proton,
Use an aqueous solution of acid such as hydrochloric acid, nitric acid, sulfuric acid, or
A method of desorbing the compound represented by the general formula (I) by performing gas phase heat treatment is used. When the cation species is a metal ion, the corresponding cation hydrochloride, nitrate,
An aqueous solution of a metal salt such as sulfate is used.

The concentration of the acid aqueous solution or the metal salt aqueous solution in the case of ion exchange with the acid aqueous solution or the metal salt aqueous solution varies depending on the kind of the acid or the metal salt used, but is usually 0.0001 to
It is 10 mol / l. Furthermore, the amount ratio of the acid or metal salt to the zeolite used is expressed by the value of the ratio of the number of moles of the acid or metal salt to the exchange capacity of the zeolite, and is usually 0.1 to 0.1.
100. The pressure during the ion exchange treatment is usually atmospheric pressure, but the treatment may be performed under reduced pressure or under increased pressure. If the liquid temperature during ion exchange treatment is atmospheric pressure,
Usually, 0 to 100 ° C is used. Processing time is usually 0.1
~ 100 hours are used. Further, the ion exchange treatment may be repeated.

When the compound represented by the general formula (I) is desorbed by the gas phase heat treatment to form a proton exchange type, the gas phase heat treatment method and conditions are as follows: It can be performed by the same method and conditions as the vapor-phase heat treatment in the step of removing the attached organic matter. In the present invention, when both the ion exchange of the cation species derived from the compound represented by the general formula (I) and the step of removing the organic matter attached to the catalyst are carried out by the gas phase heat treatment, the gas phase heating apparatus shares the same. It is possible and is industrially advantageous.

The zeolite catalyst which has been contacted with the compound represented by the general formula (I) in this way and then ion-exchanged is returned to the hydration step or the removal step, preferably the hydration step, and the olefin hydration is again carried out. Used as a catalyst for the reaction.

[0031]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the present invention. Comparative Example 1 {Continuous flow hydration reaction of cyclohexene} The hydration reaction of cyclohexene was carried out using a continuous flow reactor as shown in FIG. That is, 100 g of H-type gallosilicate (SiO ₂ / Ga ₂ O ₃ atomic ratio = 50/1) and 250 g of water were charged as a hydration catalyst into a stainless steel autoclave reactor 3 having an internal volume of 2000 ml and equipped with a stirrer, and the system was charged. The atmosphere was replaced with nitrogen gas. While stirring at a rotation speed of 500 rpm, the temperature inside the reactor 3 was raised to a reaction temperature of 120 ° C., and then cyclohexene (reagent: manufactured by Aldrich) from the supply pipe 1
Was fed at a rate of 120 g / h. After the reaction liquid is separated into an oil phase and a catalyst slurry aqueous phase in a liquid-liquid separator 4 having an internal volume of 30 ml provided inside the reactor, only the oil phase flows out of the overflow pipe 5. Further, the total amount of water consumed in the hydration reaction and the water flowing out from the overflow pipe 5 as the amount of solubility in the oil phase is supplied from the supply pipe 2 so that the amount of water in the reactor 3 is kept constant. I kept it. The cyclohexanol concentration in the spilled oil was 10.3% by weight 5 hours after starting the supply of the starting material cyclohexene. Also, 2
The cyclohexanol concentration in the spilled oil after the lapse of 00 hours was 4.5% by weight.

{Removal of catalyst organic matter} Cyclohexene continuous hydration reaction After 200 hours, the catalyst was filtered, washed with water,
After drying, it was filled in a quartz glass reaction tube and heated at 500 ° C. for 5 hours while flowing a mixed gas of 4 mol% oxygen and the balance nitrogen at a flow rate of 150 Nl / h at normal pressure, and then cooled. , The catalyst was taken out. The catalyst after the vapor-phase heat treatment was pure white, and no carbon component was found even after analysis with a CHN analyzer.

{Repeat of organic matter removal and continuous flow hydration reaction} Continuous flow hydration reaction and organic matter removal are repeated 4 times using the same catalyst under exactly the same hydration reaction conditions and gas phase heat treatment conditions as above. It was After the second to fifth organic matter removal, all the catalysts were pure white, and no residual carbon component was observed even when analyzed by a CHN analyzer. Cyclohexanol concentration in the effluent oil was 7.9% by weight at the fifth hour of the continuous flow hydration reaction using the catalyst after the fifth organic matter removal.

Example 1 The catalyst after the fifth organic matter removal, which was obtained by repeating the continuous flow hydration reaction and the organic matter removal by the vapor phase heat treatment in the same manner as in Comparative Example 1, was used in an amount of 7% by weight, which is 10 times the dry weight of the catalyst. The mixture was stirred in ammonia water while maintaining the temperature at 80 ° C. for 4 hours. After that, the catalyst is filtered, washed with water, dried, and then filled in a quartz glass tube,
While flowing air at a flow rate of 150 Nl / h at atmospheric pressure, 500
After heating at 0 ° C. for 5 hours, it was cooled and taken out as an H-type catalyst.

Using this catalyst, a continuous flow hydration reaction was carried out under the same reaction conditions as in Comparative Example 1 {continuous flow hydration reaction of cyclohexene}. The cyclohexanol concentration in the spilled oil in the fifth hour of the continuous flow hydration reaction was 9.6% by weight.
Met.

[0036]

EFFECT OF THE INVENTION According to the method of the present invention, the olefin hydration reaction can be carried out while remarkably suppressing the decrease in the activity of the catalyst, which is very advantageous in industrial practice.

[Brief description of drawings]

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

[Explanation of symbols]

 1. Cyclohexene supply pipe 2. Water supply pipe 3. Autoclave reactor 4. Liquid-liquid separator 5. Overflow pipe

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location // C07B 61/00 300 C07B 61/00 300

Claims (4)

[Claims] 1. A hydration step of hydrating an olefin in the presence of a zeolite catalyst, a removal step of removing organic substances adhering to the zeolite catalyst used in the hydration step, and a catalyst after the removal step to the hydration step. In an olefin hydration method having a feeding step, at least a part of a zeolite catalyst is extracted from a hydration step or a removal step, the zeolite catalyst is contacted with a compound represented by the following general formula (I), and then ion exchange is performed. And then returning to the hydration step or the removal step. ## STR00001 ## NR ¹ R ² R ³ (I) (In the formula, R ¹ , R ² and R ³ are a hydrogen atom and a carbon number of 1 to 1.
4 represents an alkyl group or an amino group. ) 2. The olefin hydration method according to claim 1, wherein the compound represented by the general formula (I) is ammonia. 3. The olefin hydration method according to claim 1, wherein the ion exchange is carried out by bringing the zeolite catalyst into contact with a gas containing molecular oxygen at 200 to 600 ° C. 4. The removing step is a method of bringing the zeolite catalyst into contact with a gas containing molecular oxygen at a high temperature or a method of bringing the zeolite catalyst into contact with an oxidizing agent in a liquid phase. The method for hydrating an olefin according to any one of items.