JP2528067B2 - Method for producing 1,4-cyclohexane dimethanol - Google Patents

Description

Detailed Description of the Invention

[0001]

[Industrial applications]

The present invention is 1,4-cyclohexanedimethanol (hereinafter sometimes referred to as 1,4-CHDM).
Manufacturing method.

[0003]

[Prior art]

1,4-CHDM is useful as a raw material for polyester-based paints, polyester-based synthetic fibers, synthetic resins and the like, and particularly for producing resins and fibers excellent in heat resistance, weather resistance and physical strength. Used as a raw material.

A typical method for producing 1,4-CHDM is a method in which a benzene ring and an ester group are hydrogenated using a terephthalic acid dialkyl ester produced as an industrial raw material. That method has been reported.

For example, US Pat. No. 3,334,149
In the No. 1, terephthalic acid dialkyl ester was used as the raw material, the raw material and hydrogen were introduced from the upper end of the fixed bed type continuous hydrogenation device, and hydrogen was added to the benzene ring using the palladium hydrogenation catalyst packed in the tower. After that, the reaction product and hydrogen are extracted from the lower end of the reaction tower, and the reaction product and hydrogen of the first stage are introduced from the upper end of the fixed-bed continuous hydrogenation device of the second stage, and the reaction mixture is filled into the tower. A method for obtaining the desired 1,4-CHDM by hydrolyzing the ester portion of the reaction product of the first stage using the existing copper chromite hydrogenation catalyst and then extracting it from the lower end of the reaction column is introduced.

In US Pat. No. 5,030,771, 1,4-cyclohexanedicarboxylic acid dialkyl ester is used as a raw material, and a copper chromite catalyst containing an alkali metal such as barium as a promoter is used. A method of hydrolyzing the ester portion of the raw material and then withdrawing it from the lower end of the reaction column to obtain the desired 1,4-CHDM is introduced.

[0008]

[Problems to be Solved by the Invention]

However, problems remain in any of the methods.

For example, the above-mentioned US Pat. No. 3,334,1
In the method of No. 49, in both the first-stage hydrogenation reaction and the second-stage hydrogenation reaction, the so-called down, which is to introduce the reactant and hydrogen from the upper end of the reaction column and withdraw from the lower end of the reaction column Since the flow system is adopted and the palladium hydrogenation catalyst is used as the catalyst for the first stage hydrogenation reaction, various restrictions and inconveniences have occurred.

That is, depending on the type of catalyst employed and the hydrogenation system, the reaction conditions may range from 100 ° C to 350 ° C.
° C., Among embodiments, 0.99 ° C. to 275 ° C., the pressure 50 atm to 500 atm, is in the example 385 kg / cm ² ~
Must be 390 kg / cm ^2, moreover, 1 the introduction ratio of the hydrogen and the reactant molar ratio during the first stage of the hydrogenation reaction: 1:90: 180, during hydrogenation in the second stage It was necessary to select relatively strict hydrogenation conditions such as a molar ratio of 1: 100 to 1: 300.

[0012] Due to the severe hydrogenation conditions, it becomes difficult to sufficiently suppress the progress of side reactions, and impurities having a high boiling point are generated in the reaction product, which often impairs the activity of the catalyst. There was a problem left to say.

In the case of such a continuous hydrogenation reaction, generally, excess hydrogen after the reaction is often recovered and used again in the reaction. However, in the technique introduced in this US patent, As a result of producing impurities in the reaction product, many impurities are accumulated in the recovered hydrogen, so that there is also a problem that it is necessary to purify the hydrogen by a method such as an adsorption method before reuse.

Further, this hydrogenation reaction is an exothermic reaction, and in order to keep the reaction temperature constant, it is necessary to efficiently remove the generated heat of reaction, but as mentioned above, the downflow system is adopted. Since most of the medium that transfers the heat generated on the catalyst surface to the outside is hydrogen, the heat conduction efficiency is low, and it is necessary to increase the flow rate of hydrogen in the reaction column very much for heat removal. There was also a problem to say.

When the down-flow type hydrogenation reaction is adopted, generally, a method is adopted in which a thin film of the reaction product is formed on the surface of the catalyst to flow down, and the reaction product is not actively stirred and the catalyst is not stirred. Since the mass transfer on the surface is not carried out promptly, it is necessary to keep the film of the reactant on the catalyst surface thin in order to improve the efficiency of hydrogen addition. The flow rate is 90 times the supply amount of the reactant
There is also a problem that it needs to be increased to about 300 times mol.

For the reasons described above, it is difficult to remove the heat generated in the reaction system, and thus it is not possible to employ a ruthenium catalyst, which is cheaper than the palladium catalyst but weak to heat, and The reaction product is mixed with the reaction product so that the concentration of the reaction product is usually about 4 to 16%, and at most 6%.
Various problems that are industrially disadvantageous, such as the need to suppress it to about 0%, remain.

On the other hand, in the method introduced in US Pat. No. 5,030,771, there is no description of improvement regarding the problem of the first stage hydrogenation, and the downflow method is adopted as the reaction method. Therefore, in addition to various industrially disadvantageous problems as in the case described above, there is also a problem that it is difficult to obtain the raw material as compared with the above method.

In view of the above circumstances, various reaction conditions such that the reaction conditions can be made mild as much as possible, suppression of side reactions and improvement of the purity of the product obtained as a result, raw materials to be used and materials such as hydrogen are used. There was a demand for improvements that could save money.

[0019]

[Means for Solving the Problems]

Means for solving the problems of the present invention are as follows.

The inventors of the present invention have conducted extensive studies in order to solve the above-mentioned various problems, and as a result, have found that hydrogenation of the first stage of terephthalic acid dialkyl ester, that is, nuclear saturation at high temperature. Made it possible to adopt a ruthenium-based catalyst, which was considered to be not suitable, and found a relatively mild hydrogenation condition and succeeded in improving various problems of the conventional method as described above. The invention was completed.

According to the first aspect of the present invention, in producing 1,4-cyclohexanedimethanol, (1) a fixed bed continuous filled with a ruthenium hydrogenation catalyst having a ruthenium metal loading ratio of 0.05 to 10% by weight. Hydrogen is introduced into the upper end or the lower end of the formula type hydrogenation apparatus, and at the same time, terephthalic acid dialkyl ester or the terephthalic acid dialkyl ester and the first stage hydrogenation reaction product as SV (catalyst volume 1 and Space velocity per hour when doing) = 1
10 to 10, the initial concentration of unreacted components of the first stage hydrogenation reaction is 5 to 100% by weight, and the temperature is 90 to 240.
The first step of carrying out the first stage hydrogenation reaction under the conditions of ℃ and hydrogen pressure of 5 to 150 kgf / cm ² and discharging the reaction product and excess hydrogen from the lower end or the upper end of the apparatus, (2) copper chromite hydrogen Introducing hydrogen into the upper or lower end of a fixed bed continuous hydrogenation apparatus filled with a hydrogenation catalyst, and at the same time, a first stage hydrogenation reaction product or a compound represented by the formula (I) as a second raw material, A mixture of a compound represented by (II) and a compound represented by the formula (III), in which two or more kinds selected from the group consisting of the compound represented by the formula (III) are bonded to each other by transesterification in an arbitrary combination with each other in the first stage. The hydrogenation reaction product and SV = 0.1 to 1 were introduced, and the initial concentration of the unreacted components of the second stage hydrogenation reaction was set to 10 to 100% by weight, the temperature was 200 to 300 ° C, and the hydrogen pressure was 50 to 50%. 180 kgf / c
It is characterized in that the second stage hydrogenation reaction is carried out under the condition of m ² and the reaction product and the surplus hydrogen are discharged from the lower end or the upper end of the apparatus, and the second step is sequentially passed. This is a method for producing 1,4-cyclohexanedimethanol.

[0023]

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[0024]

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[0025]

[Chemical 6]

In the second aspect of the present invention, when 1,4-cyclohexanedimethanol is produced, (1) hydrogen is introduced from the lower end of a fixed bed continuous hydrogenation device equipped with a perforated plate at the bottom of the device, At the same time, the first step of introducing the first raw material, carrying out the first-stage hydrogenation reaction, and discharging the reaction product and excess hydrogen from the upper end of the apparatus, (2) installing a perforated plate at the bottom of the tower Hydrogen is introduced from the lower end of the provided fixed bed continuous hydrogenation device, at the same time, the second raw material is introduced, the second stage hydrogenation reaction is performed, and the reaction product and excess hydrogen are discharged from the upper end of the device. In the method for producing 1,4-cyclohexanedimethanol described in the first item, the first step and the second step are sequentially performed.

In the third aspect of the present invention, the concentration of the unreacted components of the first raw material is adjusted to be in the range of 5 to 20% by weight, and the first stage hydrogenation reaction is carried out to obtain the unreacted components of the second raw material. Concentration 20 ~
The method for producing 1,4-cyclohexanedimethanol according to any one of the first to second aspects, characterized in that the second stage hydrogenation reaction is carried out by adjusting the range to 100% by weight.

The fourth aspect of the present invention is carried out in such a manner that the introduction ratio of the first raw material and hydrogen is in the range of 1: 6 to 1:33 and the introduction ratio of the second raw material and hydrogen is 1 in the molar ratio. : 14-1: 84
The method for producing 1,4-cyclohexanedimethanol according to any one of the first to third aspects, wherein the method is carried out in the range of

According to a fifth aspect of the present invention, the velocities when the raw material and hydrogen pass through the apertures of the mortar plate are 0.01 m / sec to 1.0 m / sec and 0 in linear velocity, respectively. The method for producing 1,4-cyclohexanedimethanol according to any one of the second to fourth aspects, characterized in that it is adjusted to fall within a range of 1 m / sec to 12.0 m / sec.

The quality of the terephthalic acid dialkyl ester used as the raw material of the present invention is such that it can be sold as an industrial raw material, and the type is such that the alcohols formed as a by-product are easily separated. For reasons, alkyl moieties of up to 4 carbons are preferred, of which 1 carbon terephthalic acid dimethyl ester is most advantageously used.

The first stage hydrogenation reaction of the present invention, that is,
The concentration of the raw material used for the saturation of the benzene ring is preferably 5 to 100%, more preferably 5 to 20% from the viewpoint of increasing the reaction rate and appropriately suppressing the heat of reaction. To add to the terephthalic acid dialkyl ester for adjustment, the reaction product after the first stage hydrogenation reaction is inert to the first stage hydrogenation reaction and the subsequent separation It is most preferable because it can be recovered by operation, and it is better not to mix extra components into the reaction system.

As for the quality of hydrogen used in the first stage hydrogenation reaction of the present invention, those commercially available for industrial use are sufficient, but in addition, excess hydrogen recovered by carrying out the present invention is also used. It can be used as it is or after purification if necessary.

The ruthenium hydrogenation catalyst used as the catalyst for the first-step reaction of the present invention can be generally used as long as it is a ruthenium catalyst capable of adding hydrogen to the benzene nucleus. , Silica, alumina, diatomaceous earth, activated carbon, etc., but alumina is the most preferable in terms of specific gravity and strength, and the preferable amount of ruthenium metal supported is 0.05 to 10%.

The supported amount of this ruthenium metal is 0.05%
If it is less than 10%, the amount of catalyst to be handled becomes unnecessarily large and the apparatus becomes large, which is economically disadvantageous and unreduced substances are easily generated.
If it exceeds, the loss of metal tends to occur due to peeling of ruthenium from the carrier, and the reduction efficiency does not increase despite the large amount supported, which is not preferable.

In carrying out the present invention, the fixed bed continuous hydrogenation apparatus used for the first stage hydrogenation of the present invention is provided with an inlet for hydrogen and a raw material at the upper or lower end of the apparatus and at the other end. It is necessary to have a structure capable of controlling temperature, which is provided with an outlet for hydrogen and the hydrogenation reaction product of the first stage.

The shape of the apparatus is not particularly limited as long as the hydrogenation reaction proceeds sufficiently, but in general,
A vertically long cylinder with a vertical length of 1 or more for a diameter of 1 can be used for hydrogenation reactions, catalyst regeneration, catalyst replacement, and other various repairs. It is most preferable for

The reaction method for carrying out the present invention includes (1)
Hydrogen and raw materials are supplied from the lower end of the device and discharged from the upper end, so-called upper flow method, (2) Hydrogen and raw materials are supplied from the upper end of the device and discharged from the lower end,
A so-called downflow method, (3) a so-called counterflow method in which a raw material is supplied from the upper end of the device and discharged from the lower end, and hydrogen is supplied from the lower end of the device and discharged from the upper end, can be adopted. According to the inventor's confirmation, the methods (1) and (2) are the best.

In the method (1), when supplying hydrogen and raw materials, a slightly higher pressure than that in the tower is required, and hydrogen and other materials such as a diffusion plate, a distributor or a plate plate are provided at the bottom of the tower. Although functions and parts for sufficiently mixing and dispersing the raw materials are required, they have excellent features such as easy temperature control in the reactor and easy control of the residence time of the raw materials in the reactor. .

Further, in the case of the method (2), although a function and parts such as a distributor for mainly sufficiently dispersing the raw materials on the catalyst are required, the L / D of the apparatus is required.
It has excellent features such that the ratio of (length / diameter) can be increased and the thickness of the device can be reduced.

In a further preferred embodiment of the present invention, it is preferable that the lower end of the apparatus is provided with a sparse plate, and the sine plate is a laminar flow of raw material and hydrogen introduced from the lower end of the apparatus. As long as it has the ability to bring the state to an ideal state even a little closer to that state, the material is required to have the raw materials and the solvent used in the present invention, not to be attacked by the reaction product, and to withstand the heat during the reaction. However, there are no further restrictions on the material and restrictions on the shape and number of holes.

In order to exert its performance as a perforated plate, for example, it is preferable that when it is attached to the lower end of the device, it has a certain open area ratio without any unnecessary gap in its edge portion. The porosity is, for example, 0.01 m / sec to 1.0 m / sec and 0.1 m, which are linear velocities when the raw material and hydrogen pass through the perforated portion of the perforated plate, respectively.
It is preferable to adjust the opening area so as to be in the range of 1 / sec to 12.0 m / sec.

The open area of the perforated plate is too large so that the linear velocities of the raw material and hydrogen are each less than 0.01 m / sec, or 0.1
If it is less than m / sec, the hydrogen reaching the inlet of the reaction system and the raw material are not well mixed and are not easily dispersed in the reaction column, which tends to cause a deviation in the flow direction in the column. However, if the opening area is too small and the linear velocities of the raw material and hydrogen when passing through the perforated plate exceed 1.0 m / sec and 12.0 m / sec, respectively, A large difference between the pressure in the reaction tower and the supply port to the reaction tower and the catalyst in the part corresponding to the flow passing through the perforated plate starts moving and the catalyst is damaged,
It is not preferable because of unevenness in the reaction.

The introduction rate of the raw materials suitable as the conditions for carrying out the first stage hydrogenation reaction of the present invention is affected variously by the shape of the apparatus, the amount of the catalyst, the residual activity of the catalyst, the reaction temperature, the pressure and the like. Therefore, it is difficult to uniquely express it, but normally, when expressed by SV (space velocity per hour when the catalyst volume is 1), SV = 1 to 10
It is preferable that

If the introduction rate of each raw material is less than 1, it often causes decomposition of the raw materials and reaction products, and if it exceeds 10, unreacted substances are discharged from the apparatus. As a result, the yield is often lowered, which is not preferable.

The introduction ratio of the raw material and hydrogen in the first stage hydrogenation reaction is preferably about 1: 6 to 1:33 by molar ratio, but when the ratio is less than 1: 6, hydrogen is reacted. It is not preferable because it may not spread all over the tower or the reaction may slow down. When the ratio exceeds 1:33, the raw materials in the reaction tower are excessively stirred. It is not preferable because unreacted components may be discharged from the upper end of the reaction column and the catalyst may be damaged.

The temperature during the first stage hydrogenation reaction is preferably 90 to 240 ° C. When the temperature is out of this temperature range, unreacted substances are produced when the temperature is low, and when the temperature is high. Is not preferable because decomposition products are produced, and in many cases, the yield is lowered.

[0047] Furthermore, the hydrogen pressure during the hydrogenation reaction of the first stage is preferably about 5~150kgf / cm ^2, when the pressure is less than 5 kgf / cm ^2, the rate of hydrogenation reaction becomes slow Because of that, 150k
When it exceeds gf / cm ² , the reaction rate of the hydrogenation reaction does not increase with the increase of the pressure, which is not preferable because it has no economic meaning.

By carrying out the first-stage hydrogenation reaction in this manner, impurities such as hexahydrobenzoic acid methyl ester, methylcyclohexane, terephthalic acid dimethyl ester, etc., having a purity of about 98 to 99.5% are contained. It is possible to produce the first stage hydrogenation reaction product in a total amount of about 2 to 0.5%, that is, the nuclear saturated product of the terephthalic acid dialkyl ester.

Next, the second stage hydrogenation reaction of the present invention will be described.

As the raw material used in the second stage hydrogenation reaction of the present invention, that is, the second raw material, the first stage hydrogenation reaction product or the compound represented by the above formula (I) and the above A mixture of two or more compounds selected from the group consisting of the compound represented by the formula (II) and the compound represented by the formula (III), which are bonded to each other by any desired combination by transesterification and 1 to 10; The first stage hydrogenation reaction product is used.

Specifically, the hydrogenation reaction product of the first stage can be used as it is, but the hydrogenation reaction product of the second stage, the still residue after distillation or the crude product 1 , 4-
It is also possible to adjust the concentration of unreacted substances in the second stage hydrogenation reaction by adding 1,4-CHDM-containing substances such as CHDM before or after the entrance of the apparatus.

The concentration of the unreacted substance of the second raw material of the present invention is
From the meaning of increasing the hydrogenation reaction rate in the second stage, the meaning of appropriately suppressing the reaction heat, etc., about 20 to 100% is preferable, and in order to adjust this concentration, the above 1,4
It is preferable to add -CHDM and / or its derivative-containing material and adjust the concentration to this range.

The quality of hydrogen used in the second-stage hydrogenation reaction of the present invention is sufficient to be used in the first-stage hydrogenation reaction, and the surplus recovered by carrying out the present invention is sufficient. Hydrogen as it is, or after purification if necessary,
Can be used.

The copper chromite hydrogenation catalyst used as the catalyst for the second-stage reaction of the present invention may be any one as long as it has the ability to hydrolyze the ester group portion contained in the second raw material, and is commercially available. A hydrogenation catalyst can be used, but there are no particular restrictions on the ratio of copper or chromium or the carrier.

The apparatus used for the second-stage hydrogenation reaction of the present invention is also required to have the same structure and shape as the apparatus used for the first-stage hydrogenation reaction. There are no restrictions.

Further, the perforated plate provided in the lower part of the second-stage device adopted in the preferred embodiment of the present invention has the same performance, material and open area as the perforated plate used in the first-stage device. Yes, there are no other restrictions that should be required.

Next, the conditions for the second stage hydrogenation reaction will be described.

First, the introduction rate of the raw materials suitable as the conditions for carrying out the second stage hydrogenation reaction of the present invention has various influences depending on the shape of the apparatus, the amount of the catalyst, the residual activity of the catalyst, the reaction temperature, the pressure and the like. Since it is difficult to express uniquely, it is usually preferable to set SV = 0.1-1.

When the introduction rate of the second raw material is less than 0.1, the constituents of the second raw material and the hydrogenation reaction product may be decomposed. It may be discharged from the device, and in any case, the yield is often lowered, which is not preferable.

The introduction ratio of the second raw material and hydrogen is preferably in the range of 1:14 to 1:84 by molar ratio, but if the ratio is less than 1:14, hydrogen may not spread into the reaction column. It is not preferable for the reason that it may occur or the reaction may slow down, and if the ratio exceeds 1:84, the raw materials in the reaction tower are excessively stirred and unreacted components This is also not preferable because it may be discharged from the reaction tower or the catalyst may be damaged.

The temperature during the second stage hydrogenation reaction is 200
Although the temperature is preferably up to 300 ° C., when the temperature is out of this range, the yield is often lowered due to the production of unreacted substances or decomposed products, which is not preferable.

[0062] Further, the second stage hydrogen pressure during the hydrogenation reaction of is preferably in the range of 50~180kgf / cm ^2, if the pressure is less than 50 kgf / cm ^2, it may slow down the hydrogenation reaction For reasons such as
If the pressure exceeds 180 kgf / cm ² , even if the pressure is increased, the reaction rate of the hydrogenation reaction does not increase accordingly, so that neither is economically desirable, and therefore neither is preferable.

By carrying out the second-stage hydrogenation reaction in this manner, the purity after removal of methanol by a gas-liquid separator or the like is about 93 to 96%, and 4-methylcyclohexanemethanol, 4-methylcyclohexanemethanol 1,4-Methyl hydroxymethylcyclohexanecarboxylate, hexahydrodimethyl terephthalate, methanol and 1,4-containing 4 to 7% of impurities such as compounds represented by formula (I)
The CHDM-containing material can be produced with a high yield, but thereafter, by a usual means such as distillation or fractionation,
1,4-CHDM-containing material produces 1,4-
CHDM can be easily recovered.

[0064]

【Example】

The contents of the present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

In the examples,% represents% by weight unless otherwise specified.

Example-1 (first step and second step)

Continuous stainless steel hydrogenation reaction in which alumina-supported 0.5% ruthenium hydrogenation catalyst pellets (3φ × 3 mm) [manufactured by NE Chemcat] 0.21 m ³ were filled and the temperature was kept at 120 ° C. Device (SUS
316L), as a first raw material, a mixture of 80% terephthalic acid dimethyl ester and 20% terephthalic acid dimethyl ester, which were nuclear-saturated, was heated and dissolved at 120 ° C. (Space velocity per time) = 6, and at the same time, hydrogen was mixed in a pipe in advance at a rate corresponding to 18 times the total amount of unreduced materials as raw materials, and heated to 120 ° C. in a preheater. Was continuously supplied from the upper end of.

At this time, the hydrogen pressure in the apparatus was 100 kgf /
The reaction product and surplus hydrogen are discharged from the lower end of the device by carrying out the first-stage hydrogenation reaction while maintaining the same in cm ² , and the surplus hydrogen is separated by a gas-liquid separator to obtain a nuclear-saturated terephthalate. A first stage hydrogenation reaction product having a purity of acid dimethyl ester of 98.98% was obtained.

Next, a catalyst for hydrogenating copper chromium hydrogen [Cu Chem 1164T, Cu-1164T] 0.28 m
^From the upper end of a continuous hydrogenation reactor made of stainless steel (SUS316L) filled with ³ and kept at a temperature of 250 ° C,
The hydrogenation reaction product of the first stage was used as the second raw material at 250 ° C.
What was heated to SV = 0.45 per hour, and at the same time, hydrogen was preliminarily gas-liquid mixed in the pipe at a rate equivalent to 44 times the total amount of unreacted substances in the second stage hydrogenation reaction and preheated. After being heated to 250 ° C. in a vessel, it was continuously fed from the upper end of the apparatus.

At this time, the hydrogen pressure in the apparatus was set to 150 kgf /
The second stage hydrogenation reaction was carried out with the pressure held at cm ² , and the reaction product and excess hydrogen were discharged from the lower end of the apparatus to obtain a hydrogenation reaction product.

The obtained reaction product was subjected to gas-liquid separation under the same temperature and the same pressure as during the reaction to remove excess hydrogen and methanol, and then the composition was analyzed by gas chromatography. The purity of 4-cyclohexanedimethanol was 94.0%, and impurities contained in the product were methyl 4-hydroxymethylcyclohexanecarboxylate, dimethyl 1,4-cyclohexanedicarboxylate and the like.

Example-2 (first step)

In place of the alumina-supported 0.5% ruthenium hydrogenation catalyst pellets of Example-1, the same company, same-sized alumina-supported 0.1% ruthenium hydrogenation catalyst was used. The heating temperature and the reaction temperature are 170 ° C., and the hydrogen pressure during the reaction is 150 kgf / c.
m ² , the raw material supply rate is SV = 3, and the hydrogen supply rate is 3
As a result of carrying out the first-stage hydrogenation reaction in the same manner as in Example 1 except that the molar ratio was 3-fold, a first-stage hydrogenation reaction product having a purity of 95.50% was obtained.

Example-3 (first step)

The raw material and hydrogen were introduced at the linear velocities of 0.53 m / sec and 3.1 m / sec respectively from the lower end of the hydrogenation device equipped with a perforated plate at the bottom, and the product and excess hydrogen were discharged from the upper end. As a result of carrying out the first-stage hydrogenation reaction in the same manner as in Example 1 except for the above, a first-stage hydrogenation reaction product having a purity of 99.12% was obtained.

Example-4 (first step)

Example 2 and Example 2 except that the raw material and hydrogen were introduced from the lower end of the hydrogenation apparatus, the product and excess hydrogen were discharged from the upper end, and the raw material residual heat temperature, the apparatus heating temperature and the reaction temperature were 120 ° C. As a result of carrying out the first stage hydrogenation reaction in the same manner, a first stage hydrogenation reaction product having a purity of 93.69% was obtained.

Example-5 (first step)

Alumina-supported 1.0% ruthenium hydrogenation catalyst (manufactured by NE Chemcat Co., 3φ × 3 m)
m) is used, the raw material residual heat temperature, the apparatus heating temperature and the reaction temperature are 170 ° C., and the hydrogen pressure during the reaction is 9 kgf / cm 2.
² , a mixture of 95% terephthalic acid dimethyl ester and 5% terephthalic acid dimethyl ester, which had been nuclear-saturated, was heated and dissolved, and the raw material supply rate was SV = 2 and the hydrogen supply rate was 84%. As a result of carrying out the first-stage hydrogenation reaction in the same manner as in Example 3 except that the molar amount was doubled, a first-stage hydrogenation reaction product having a purity of 99.17% was obtained.

Example-6 (first step)

The raw material residual heat temperature, the apparatus heating temperature and the reaction temperature were set to 170 ° C., and the hydrogen pressure during the reaction was set to 9 kgf / cm ^2.
And the raw material feed rate was SV = 1 and the hydrogen feed rate was 33 times mol, and the first-stage hydrogenation reaction was carried out in the same manner as in Example-3, and as a result, the first-stage hydrogen with a purity of 92.67% was obtained. A hydrogenation reaction product was obtained.

Example-7 (first step)

Alumina-supported 0.5% ruthenium hydrogenation catalyst (manufactured by NE Chemcat, 3φ × 3 mm)
The raw material residual heat temperature, the apparatus heating temperature and the reaction temperature to 9
Example in which the temperature was set to 0 ° C., a mixture of 90% of terephthalic acid dimethyl ester and 10% of terephthalic acid dimethyl ester that had been nuclear-saturated was heated and dissolved, and the raw material supply rate was SV = 2. As a result of carrying out the first stage hydrogenation reaction in the same manner as in -4, a first stage hydrogenation reaction product having a purity of 99.42% was obtained.

Example-8 (first step)

As the first raw material, a mixture of 80% terephthalic acid dimethyl ester and 20% terephthalic acid dimethyl ester, which had been nuclear-saturated, was heated and dissolved, and the raw material supply rate was set to SV = 3. As a result of carrying out the first stage hydrogenation reaction in the same manner as in 7, the purity was 98.71%.
The first stage hydrogenation reaction product of was obtained.

Example-9 (second step)

From the lower end of the second-stage continuous hydrogenator equipped with a perforated plate at the bottom, the second raw material and hydrogen were supplied at a linear velocity of 0.
The hydrogenation reaction was performed in the same manner as in the second step of Example-1 except that the reaction product and excess hydrogen were discharged from the upper end at 14 m / sec and 8.7 m / sec. As a result of analyzing the product by gas chromatography, the purity of 1,4-cyclohexanedimethanol in the product was 95.
5%.

Example-10 (second step)

The hydrogenation reaction was carried out in the same manner as in the second step of Example-1, except that the product obtained in Example-2 was used as the second raw material and the supply rate was SV = 0.90. As a result of analyzing the obtained reaction product, 1,4-
The cyclohexanedimethanol purity was 93.2%.

Example-11 (second step)

Using the product obtained in Example-6 as the second raw material, the second stage hydrogenation reaction temperature and the second raw material heating temperature,
The preheating temperature is 270 ° C., and the supply rate of the second raw material is SV =
The hydrogenation reaction was performed in the same manner as in the second step of Example-1 except that the hydrogen supply rate was 0.30, the hydrogen supply rate was 64 times mol, and the hydrogen pressure was 100 kgf / cm ² , and the obtained reaction product was analyzed. As a result, the purity of 1,4-cyclohexanedimethanol in the product was 91.1%.

Example-12 (second step)

Hydrogenation reaction was carried out in the same manner as in Example 11 except that the hydrogen pressure was 150 kgf / cm ² , and the obtained reaction product was analyzed. As a result, 1,4-cyclohexanedimethanol in the product was analyzed. The purity was 92.0%.

Example-13 (second step)

Cu-1132-T manufactured by NE Chemcat Co., Ltd. was used as the catalyst, the product obtained in Example-3 was used as the second raw material, and the second stage hydrogenation reaction temperature and the second raw material were used. Results of analyzing the obtained reaction product by carrying out hydrogenation reaction in the same manner as in the second step of Example-1 except that the heating temperature and the preheating temperature were 230 ° C. and the hydrogen supply rate was 84 times mol. The purity of 1,4-cyclohexanedimethanol in the product was 96.0%.

Example-14 (second step)

The hydrogenation reaction was carried out in the same manner as in Example-13 except that the second stage hydrogenation reaction temperature, the second raw material heating temperature and the preheating temperature were 250 ° C. and the hydrogen supply rate was 44 times mol. As a result of analyzing the obtained reaction product, the purity of 1,4-cyclohexanedimethanol in the product was 96.
It was 3%.

Example-15 (second step)

As the second raw material, the first stage hydrogenation reaction product of Example-1 was mixed with the distillation residue of the second stage hydrogenation reaction product to adjust the unreduced product concentration of the second stage hydrogenation reaction to 77. ．
A hydrogenation reaction was carried out in the same manner as in Example-9 except that the product adjusted to 1% was used, and the obtained reaction product was analyzed. As a result, the purity of 1,4-cyclohexanedimethanol in the product was It was 96.0%.

[0101]

【The invention's effect】

As described above, by carrying out the present invention, it becomes possible to employ a ruthenium catalyst which is cheaper than palladium, and the hydrogenation of the first stage under milder conditions than conventional ones can be carried out. The reaction can be realized, the amount of impurities produced in all steps can be reduced, and 1,4-cyclohexanedimethanol can be economically produced.

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Claims (5)

(57) [Claims] 1. When producing 1,4-cyclohexanedimethanol, a fixed-bed continuous hydrogenation apparatus filled with (1) a ruthenium hydrogenation catalyst having a ruthenium metal loading ratio of 0.05 to 10% by weight is used. Hydrogen is introduced into the upper end or the lower end, and at the same time, terephthalic acid dialkyl ester as the first raw material or terephthalic acid dialkyl ester and the first stage hydrogenation reaction product are mixed with SV (1 hour when the catalyst volume is 1). (Space velocity per unit) = 1 to 10, and the initial concentration of unreacted components in the first-stage hydrogenation reaction is 5 to 5
100% by weight, temperature 90 to 240 ° C., hydrogen pressure 5
The first step of carrying out the first stage hydrogenation reaction under the condition of up to 150 kgf / cm ² and discharging the reaction product and excess hydrogen from the lower end or the upper end of the apparatus, (2) is filled with a copper chromite hydrogenation catalyst Hydrogen is introduced into the upper or lower end of the fixed bed continuous hydrogenation device, and at the same time, the first stage hydrogenation reaction product as the second raw material, the compound represented by the formula (I) or the compound represented by the formula (II) is used. And a mixture of compounds in which 2 to 10 selected from the group consisting of compounds represented by formula (III) are bound to each other by transesterification in an arbitrary combination with each other and a first stage hydrogenation reaction product And SV = 0.1
˜1, and the initial concentration of the unreacted components of the second stage hydrogenation reaction is 10 to 100% by weight, and the temperature is 200 to 300.
The second step of carrying out the second stage hydrogenation reaction under the conditions of ℃ and hydrogen pressure of 50 to 180 kgf / cm ² and discharging the reaction product and surplus hydrogen from the lower end or the upper end of the apparatus is carried out sequentially. The method for producing 1,4-cyclohexanedimethanol is characterized in that Embedded image Embedded image Embedded image 2. When producing 1,4-cyclohexanedimethanol, (1) hydrogen is introduced from the lower end of a fixed bed continuous hydrogenation device equipped with a perforated plate at the bottom of the device, and at the same time, the first raw material is introduced. Is introduced, the first stage hydrogenation reaction is carried out,
First step of discharging the reaction product and excess hydrogen from the upper end of the device, (2) introducing hydrogen from the lower end of a fixed bed continuous hydrogenation device equipped with a perforated plate at the bottom of the tower, and at the same time, A second step of introducing a second raw material, performing a second stage hydrogenation reaction, and discharging a reaction product and excess hydrogen from the upper end of the apparatus, which is characterized by sequentially passing through two steps. The method for producing 1,4-cyclohexanedimethanol according to claim 1. 3. The concentration of the unreacted component of the first raw material is 5 to 20.
The first stage hydrogenation reaction is carried out by adjusting to the range of 20% by weight, and the concentration of unreacted components of the second raw material is 20 to 100% by weight.
The method for producing 1,4-cyclohexanedimethanol according to any one of claims 1 to 2, wherein the hydrogenation reaction of the second stage is carried out by adjusting to the range. 4. The introduction ratio of the first raw material and hydrogen is carried out in a molar ratio of 1: 6 to 1:33, and the introduction ratio of the second raw material and hydrogen is 1:14 to 1: 1. It implements in the range of 84, 1, in any one of Claims 1-3 characterized by the above-mentioned.
Method for producing 4-cyclohexanedimethanol. 5. The linear plate has a linear velocity such that the raw material and hydrogen pass through the apertures of the perforated plate at a velocity of 0.01.
m / sec to 1.0 m / sec and 0.1 m / sec to 12.0 m /
The method for producing 1,4-cyclohexanedimethanol according to any one of claims 2 to 4, wherein the method is adjusted to be within the range of seconds.