JP6524693B2 - Process for producing alicyclic polyvalent carboxylic acid - Google Patents

Description

  The present invention relates to a method for producing a corresponding alicyclic polyvalent carboxylic acid by continuously performing hydrogenation reaction in the presence of a solid catalyst using an aromatic polyvalent carboxylic acid as a raw material, and specifically, terephthalic acid (hereinafter referred to as The aromatic nucleus of an aromatic polyvalent carboxylic acid such as “TPA” may be hydrogenated (hereinafter sometimes referred to as “nuclear hydrogenation”) to give 1,4-cyclohexanedicarboxylic acid (hereinafter “1 , 4-CHDA "or simply" CHDA ") and the like.

  Alicyclic polyvalent carboxylic acids such as 1,4-CHDA are raw materials of alicyclic polyvalent alcohols such as 1,4-cyclohexanedimethanol, and these alcohols are polyester-based paint, polyester-based synthetic fiber, It is useful as a raw material for synthetic resins and the like, and is particularly used as a raw material for resins and fibers excellent in heat resistance, weather resistance, physical strength and the like.

  In JP-A-2002-255895, a slurry liquid is prepared from an aromatic carboxylic acid and a solvent in a method for producing an aromatic carboxylic acid hydride by hydrogenating an aromatic carboxylic acid having a melting point of 250 ° C. or higher. The slurry is continuously supplied to the reactor, the hydrogenation reaction is performed in the presence of a solid catalyst, and at least a portion of the reaction liquid continuously withdrawn from the reactor is recycled to the reactor. A process for producing a hydrogenated aromatic carboxylic acid is disclosed, which comprises carrying out a hydrogenation reaction in the vessel with substantially all of the aromatic carboxylic acid dissolved.

Here, the reactor may be a fixed bed or a stirred tank type, but the method of controlling the temperature of the reactor is not mentioned. However, when trying to carry out fixed bed reactions on an industrial scale, it is generally difficult to maintain a uniform reaction temperature in all of the reaction zones.
In addition, when circulating the reaction liquid to the reactor, in either case of fixed bed or stirred tank type, the reaction liquid may be cooled in the circulation line after it is withdrawn from the reactor or in view of heat balance. In any case, a step of cooling the reaction liquid is necessary in any case, such as whether the reaction liquid is thermally diluted in the step of mixing with the raw material liquid.

  Solution hydrogenation reaction from terephthalic acid (TPA) to 1,4-cyclohexanedicarboxylic acid (CHDA) using a stirred tank reactor In the example of the known art, the heat removal method from the reactor is generally used, A jacket system, an internal coil system, or a circulation system to an externally provided heat exchanger is shown. However, when a cooling method via such a heat transfer surface is used, the raw materials and reaction products are deposited and attached to the heat transfer surface, and the heat transfer efficiency often decreases rapidly.

Japanese Patent Laid-Open No. 2002-255895

  The first object of the present invention is to stably maintain the heat removal performance of the reaction mixture in the reactor in the step of producing the corresponding alicyclic polyvalent carboxylic acid by the hydrogenation reaction of the aromatic polyvalent carboxylic acid. , To obtain stable reaction results over a long period of time.

A second object of the present invention is to carry out heat removal of the reactor independently of heat exchange with the cooling medium. As a result, it is possible to reduce energy loss due to extremely high or low temperature of the heat medium or the like in the case of rapidly performing heating or heat removal, which causes a problem in heat removal by heat exchange.

  The third object of the present invention is to provide a method which can carry out the hydrogenation of aromatic polyvalent carboxylic acid without the need for an additional structure for heat removal. This simplifies the structure of the reactor and maintains and improves the stirring efficiency in the reactor.

  The inventors of the present invention conducted intensive studies to solve the above problems, and as a result, a reaction apparatus including at least a raw material preparation tank and a reactor is used as a reaction apparatus, and reaction heat of exothermic reaction is obtained by cold energy of an aqueous medium to be supplied. It has been found that the present invention can be completed.

The gist of the present invention resides in the following [1] to [6].
[1] In the method of hydrogenating the aromatic nucleus of aromatic polyvalent carboxylic acid in an aqueous medium to continuously produce the corresponding alicyclic polyvalent carboxylic acid, the temperature of the raw material mixture fed to the reactor is controlled The manufacturing method of the alicyclic polyhydric carboxylic acid which controls reaction temperature by carrying out.
[2] The method for producing an alicyclic polyvalent carboxylic acid according to [1], wherein the temperature of the raw material mixture supplied to the reactor is a temperature that can be compensated by the heat of reaction with respect to the reaction temperature.
[3] The mixing ratio of the aromatic polyvalent carboxylic acid and the aqueous medium in the raw material mixture is in the range of 5/95 to 50/50 as a weight ratio of aromatic polyvalent carboxylic acid / aqueous medium, [1 ] Or the manufacturing method of the alicyclic polyhydric carboxylic acid as described in [2].
[4] The reaction temperature is 100 ° C. or more and 200 ° C. or less, and the temperature of the raw material mixture supplied to the reactor is 40 ° C. to 120 ° C. lower than the reaction temperature. Process for producing alicyclic polyvalent carboxylic acid.
[5] The method for producing an alicyclic polyvalent carboxylic acid according to any one of [1] to [4], wherein the control of the reaction temperature is performed by the temperature of the raw material mixture supplied to the reactor.
[6] Any one of [1] to [5] which controls the temperature of the raw material mixture supplied to the reactor using the raw material preparation tank or the raw material temperature regulator provided between the raw material preparation tank and the reactor The manufacturing method of the alicyclic polyhydric carboxylic acid as described in 1.

  By using the method of the present invention, the heat removal performance of the reaction heat becomes less susceptible to the influence of deposits and the like, so that the reaction can be kept stable, and an additional heat removal facility is provided also inside the reactor. Therefore, the temperature control of the reactor can be easily performed.

FIG. 1 is a schematic view of a reaction apparatus showing an example in which a heat exchanger is installed between the raw material preparation tank and the reactor in the present invention so that the temperature of the raw material mixture can be controlled. FIG. 2 is a schematic view showing the heat balance of the embodiment of the present invention.

<Aromatic polyvalent carboxylic acid>
As the aromatic polyvalent carboxylic acid used in the present invention, any compound having two or more carboxyl groups bonded to an aromatic ring can be used without particular limitation.
The aromatic polyvalent carboxylic acid preferably has 2 to 4 carboxyl groups in one molecule, and particularly preferably 2 or more. An alicyclic diol is obtained from an alicyclic dicarboxylic acid which is a hydrogenated substance of an aromatic dicarboxylic acid, and this can be used as a raw material for producing a polymer. The aromatic polyvalent carboxylic acids may be used alone or as a mixture of two or more.

Examples of aromatic polyvalent carboxylic acids include aromatic polyvalent carboxylic acids having an aromatic ring having 4 to 14 carbon atoms, and specific examples thereof include phthalic acid, isophthalic acid, terephthalic acid and 2,6-naphthalene. Dicarboxylic acid, 1,1'-biphenyl-4,4'-dicarboxylic acid, trimellitic acid, pyromellitic acid etc. are mentioned.
Among these compounds, aromatic dicarboxylic acids having an aromatic ring having 4 to 10 carbon atoms are preferable, and phthalic acid, isophthalic acid, terephthalic acid, and 2,6-naphthalene dicarboxylic acid are more preferable. Most preferred is terephthalic acid.

<Aqueous medium>
The hydrogenation reaction in the process of the present invention is a liquid phase reaction and is usually carried out in the presence of a solvent. The solvent is not particularly limited as long as it does not react with the raw materials and products in the reaction step, does not inhibit the reaction, and does not poison the catalyst, as long as it does not adversely affect the progress of the reaction. Examples of such a solvent include water; alcohols such as methanol and ethanol; ethers such as tetrahydrofuran and dioxane; hydrocarbons such as hexane and decalin. These solvents can be used alone or in combination.

  Among them, in the hydrogenation reaction which is an exothermic reaction, it is desirable to use a solvent which causes little temperature rise due to the heat of reaction, ie, a solvent which has a large specific heat. Moreover, as a solvent, one having a high boiling point is desirable. In a solvent having a low boiling point, ie, a solvent having a high vapor pressure, the vapor pressure of the solvent is increased due to the increase in liquid temperature due to the heat of reaction, and as a result, the hydrogen partial pressure in the gas phase is reduced to introduce hydrogen into the solvent. This is because the solubility decreases and the reaction rate decreases. That is, it is preferable to use an aqueous medium containing water, especially water, as the solvent. In addition, you may contain the alicyclic polyhydric carboxylic acid which is a product in a solvent.

<Mixing ratio of aromatic polyvalent carboxylic acid and aqueous medium>
In the method of the present invention, the mixing ratio (weight ratio) of the aromatic polyvalent carboxylic acid supplied to the reactor to the aqueous medium is preferably 5/95 to 50/50. A more preferable ratio is 10/90 to 30/70.
When the mixing ratio (weight ratio) of the aromatic polyvalent carboxylic acid to the aqueous medium in the slurry is as low as 5/95, the calorific value at the time of the reaction becomes small, so the control of the reaction temperature becomes easy. However, it becomes difficult to separate the reactant and the solvent from the reaction product solution. On the other hand, when the mixing ratio of the aromatic polyvalent carboxylic acid and the aqueous medium becomes higher than 50/50, the heat of reaction becomes large, the controllability of the reaction is deteriorated, and the fluidity of the slurry is deteriorated. Problems may occur such as transport and supply to the reactor and uneven progress of the reaction. In addition, separation and recovery of the catalyst from the product solution may be difficult.

<Reaction temperature>
The reaction temperature of the hydrogenation reaction of the aromatic polyvalent carboxylic acid to which the method of the present invention is applied is preferably 100 ° C to 200 ° C, and more preferably 150 to 190 ° C. When the reaction temperature is lower than 100 ° C., the reaction rate is significantly reduced and the production efficiency tends to be reduced. On the other hand, if the reaction temperature exceeds 200 ° C., many side reactions occur, the yield of the desired product decreases, and the vapor pressure of the solvent increases, so excessive maintenance is required to maintain the same hydrogen partial pressure. Since a pressure reaction is required and a high pressure resistance of the equipment is required, the equipment cost tends to increase and the economy is inferior.

<Supply supply temperature>
The temperature at which the slurry (mainly containing a mixture of an aromatic polyvalent carboxylic acid and an aqueous medium), which is a raw material mixture used in the method of the present invention, is preferably 25 to 100 ° C. When the supply temperature of the slurry is less than 25 ° C., the temperature difference between the internal temperature of the reactor and the vicinity of the slurry supply port increases, and the component dissolved in the reaction solution precipitates around the supply port and the slurry supply port is narrowed. Or it may become occluded.

  On the other hand, if the slurry supply temperature exceeds 100 ° C, the reaction rate becomes very fast, but since this reaction is exothermic reaction, the reaction heat may be higher due to the reaction heat in some cases, possibly causing runaway reaction. is there. In order to prevent a runaway reaction, it is necessary to take measures such as limiting the volume of the reaction solution or providing a large cooling facility. By setting the supply temperature of the slurry to the reactor within the above range, the reaction can be stably and efficiently advanced, which is preferable.

<Control of reaction temperature by temperature control at the time of slurry supply>
The present invention is characterized in that the reaction temperature is controlled by adjusting the temperature of the raw material mixture slurry supplied to the reactor. The method of controlling the temperature of the raw material mixture slurry supplied to the reactor is not particularly limited, but using a reactor including a raw material preparation tank and a reactor, between the raw material preparation tank or the raw material preparation tank and the reactor It is preferable to control reaction temperature by adjusting the temperature of the said raw material mixture using the provided raw material temperature regulator.

  In the method of the present invention, an example in which a heat exchanger is installed between the raw material preparation tank and the reactor so that the temperature of the raw material can be adjusted is shown in FIG. As shown in FIG. 1, a raw material temperature regulator 4 is installed on a transfer pipe that connects the raw material preparation tank 1 and the reactor 2, and a hydrogen boost compressor 3 is connected to the reactor 2. The raw material mixture stored in the raw material preparation tank 1 is transferred to the reactor 2 by the pump 5.

Here, in order to set the reaction temperature to a desired temperature, for example, 1) the heat of reaction generated per unit time is calculated based on the feed amount of the raw material and the reaction conditions,
2) The temperature at which the reaction system rises due to the reaction is estimated by dividing this by the specific heat of the mixture of the product and the solvent,
3) Adjust the temperature of the slurry from the heat capacity of the slurry of the raw material component supplied into the system so as to meet the above temperature rise.
The method such as may be used.

Such adjustment of the reaction temperature can be achieved by adjusting the temperature of the feedstock using a raw material preparation tank or a heat exchanger (raw material temperature controller) provided between the raw material preparation tank and the reactor.
More specifically, it is supplied using one having a raw material temperature controller (temperature control means) such as a jacket (external type or internal type), an internal coil, an external circulation type heat exchanger, etc. as a raw material preparation tank. Method of preparing the raw material (slurry) and controlling the temperature, installing a heat exchanger as a raw material temperature controller on the transfer piping connecting the raw material preparation tank and the reactor, and controlling the temperature, or a combination of these, etc. It can be mentioned. From the viewpoint of efficiency and ease of clogging and maintenance, it is preferable to provide a multitubular heat exchanger (shell and tube heat exchanger) in the raw material preparation tank and / or the transfer piping.

Regulation or control of the reaction temperature of the present invention is performed by the temperature of the raw material mixture (slurry) supplied to the reactor. Furthermore, in order to improve the controllability of the reaction, the reactor may be additionally provided with a temperature control jacket.
According to the present invention, regardless of the type of solvent and the feed concentration of the raw material aromatic polyvalent carboxylic acid, it is usually possible to achieve heat balance only by heating the raw material mixture.
According to the present invention, the reaction temperature can be maintained by the controlled temperature of the feed mixture fed to the reactor and the heat of reaction. That is, it is preferable to set the temperature of the raw material mixture supplied to the reactor to a temperature that can be compensated for the reaction temperature by the heat of reaction.
Although the suitable temperature of the raw material mixture supplied to the reactor depends on the slurry concentration, when the reaction temperature is 100 ° C. to 200 ° C., 40 ° C. to 120 ° C. lower than the reaction temperature is preferable, and 50 ° C. It is preferred that the temperature be as low as -150 ° C.

<Contrast to conventional method and effect of invention>
In the conventional method, the adjustment of the reaction temperature is performed by using a filtration device from the slurry taken out of the reactor by providing an external circulation line and using solid components (solids such as Pd / C catalyst and raw material components that can not be dissolved in liquid) It is generally performed by a method of providing a heat exchanger for fluid heating in the line while separating the components).
However, in continuous filtration using, for example, a cross flow type filtration system, it is usually necessary to flow a large amount (for example, about 10 times etc.) of fluid on the primary side on the primary side. It has been necessary to provide a large heat exchanger in consideration of pressure loss and to use a pump having a large flow rate for fluid transfer.

  In the method of the present invention, since heating is performed on the upstream side of the reactor, that is, on the raw material supply line, there is no restriction on the heat transfer area and there is no need to provide a coil etc. inside the reactor. Even simple things are enough. Moreover, the pump and the like do not need a new device other than the fluid drive device such as the pump necessary for supplying the raw material, and the liquid flow rate passing through the heat exchanger is about 1 as compared with the above external circulation method. Since it is about 10, the pressure loss is small, and the additional driving force required for the pump etc. is small and sufficient.

  Hereinafter, the present invention will be described in more detail using Examples, but the present invention is not limited by the following Examples as long as the gist of the present invention is not exceeded.

Example 1
Assumptions
The terephthalic acid (TPA) is hydrogenated to produce 1,4-cyclohexanedicarboxylic acid (CHDA) using a reactor configured as shown in FIG.

First, 1599 kg / h of TPA at about 20 ° C. is mixed and dispersed in 6397 kg / h of water at 20 ° C. in a raw material preparation tank at normal temperature to prepare a slurry having a TPA concentration of 20% by weight (TPA / water (weight Ratio) = 20/80).
This slurry is pressurized with hydrogen to 6.1 MPa · G (gauge pressure, the same applies hereinafter), and supplied at a feed rate of 7996 kg / h at 91 ° C. using a multi-tubular heat exchanger provided in the middle of the slurry transfer piping. The temperature is adjusted and then fed to a stirred reactor maintained at 170.degree.

While flowing the catalyst (Pd / C catalyst) in which palladium is supported on activated carbon in the reactor so as to be 2% by weight, the inside of the stirring tank is maintained at 6.1 MPa · G, hydrogen at 114 ° C. (6. 1 MPa · G) is fed to the reactor at 2664 Nm ³ / h.
While filtering the Pd / C catalyst, the reaction product solution is continuously taken out from the reactor at a rate of 161280 kg / h and hydrogen gas containing saturated steam at 1986 Nm ³ / h, and this 95% (153224 kg / h) reactor An aqueous solution of CHDA is obtained at a production rate of 8056 kg / h, in which the aromatic nucleus of TPA is hydrogenated while being circulated to the

When the reaction temperature is a constant temperature of 170 ° C. and this operation is continued for 150 hours, the conversion of terephthalic acid is 99.8%, and the yield of CHDA is 97.5%.
The raw material slurry supply temperature (91 ° C.) at this time is estimated and determined as follows.

<Method of determining raw material supply temperature>
The heat balance in the above example is shown in FIG. FIG. 2 shows a portion of the reactor 2 taken out of the reactor shown in FIG. 1 and can not be dissolved in the two heat exchangers 4 for controlling the heat balance and the solid catalyst or liquid. A filtration module 6 is provided to filter out solid components such as raw material components and reaction products.

(Process condition)
Raw material slurry supply temperature: X ° C
Reaction temperature: 170 ° C (however, the set temperature is 172 ° C in consideration of heat dissipation loss)
Raw material hydrogen gas supply temperature: 113 ° C
Product extraction temperature: 170 ° C
Unreacted gas extraction temperature: 172 ° C
Unreacted gas condensed water return temperature: 40 ° C
Reaction solution circulation heating temperature: Input temperature 170 ° C → Output temperature 172 ° C

(Heat balance calculation)
Based on the above premise, heat balance calculation was performed using ASPEN Tech's "ASPEN Plus Ver. 7.2". Thermodynamic physical property values, such as specific heat, used for calculation were quoted or calculated using the physical property database which the said software incorporated.

The outline of the calculation procedure is described below.
(1) From the TPA supply amount (1599 kg / h) in the operation of the above example and the reaction conditions (reaction temperature 170 ° C., 6.1 MPa · G), the calorific value due to hydrogenation is 489 Mcal / h.
(2) When the temperature of the supplied hydrogen gas is set to 113 ° C. (6.1 MPa · G, 2664 Nm ³ / h), 49 Mcal / h of heating is required to raise the temperature to 172 ° C. of the reaction liquid temperature It becomes.
(3) In order to cool the gas (hydrogen gas containing saturated steam: 1986 Nm ³ / h) discharged from the reactor to 40 ° C., 83 Mcal / h is required.
(4) In order to keep the reaction temperature at 170 ° C stable, the reaction liquid at 170 ° C (TPA 1599 kg / h + water 6397 kg / h slurry) in the circulation line, the heat required for heating up to 172 ° C is 343 Mcal / H.

(Heat balance: reference temperature is 170 ° C of reaction temperature)
Heat of reaction: 489 Mcal / h
Exhaust hydrogen cooling: 83Mcal / h
Circulating reaction solution heating: 343 Mcal / h
Raw material hydrogen gas introduced cold heat:: 49 Mcal / h
Excess hydrogen / steam evaporation latent heat + 40 ° C condensation water carrying cold: 237 237Mcal / h

(Cool heat that the feedstock should bring in)
From the above results, the amount of cold heat to be supplied to the reactor by the TPA / water slurry, which is the feedstock, is
(489 + 83 + 343)-(49 + 237) = 629 Mcal / h
Is calculated.
When the supply temperature (X ° C. in FIG. 2) corresponding to this heat quantity is calculated in consideration of the above-described supply flow rate / mixing ratio and the specific heat of each component, the supply temperature of the slurry is calculated to be 91 ° C.

Example 2
It carried out like Example 1 except having changed the next point.
That is, 800 kg / h of TPA at about 20 ° C. is mixed and dispersed in 7196 kg / h of water at 20 ° C. in a raw material preparation tank at normal temperature to prepare a slurry having a TPA concentration of 10% by weight (TPA / water (weight Ratio) = 10/90). This slurry is pressurized with hydrogen to 6.1 MPa · G (gauge pressure, the same applies hereinafter), and supplied at 7996 kg / h using a multi-tube heat exchanger provided in the middle of the slurry transfer piping at 113 ° C. The temperature is adjusted and then fed to a stirred reactor maintained at 170.degree.
While flowing the catalyst (Pd / C catalyst) in which palladium is supported on activated carbon in the reactor so as to be 2% by weight, the inside of the stirring tank is maintained at 6.1 MPa · G, hydrogen at 74 ° C. (6. 1 MPa · G) is supplied to the reactor at 1342 Nm ³ / h. While filtering the Pd / C catalyst, the reaction product solution is continuously taken out from the reactor at a rate of 160789 kg / h and hydrogen gas containing saturated steam at 951 Nm ³ / h, and this 95% (152759 kg / h) reactor An aqueous solution of CHDA is obtained at a production rate of 8031 kg / h, in which the aromatic nucleus of TPA is hydrogenated while being circulated to the

The raw material slurry supply temperature (112 ° C.) at this time is estimated and determined as follows. The outline of the calculation procedure is described below.
(1) From the TPA supply amount (800 kg / h) and the reaction conditions (reaction temperature 170 ° C., 6.1 MPa · G) in the operation of the above example, the calorific value due to hydrogenation is 257 Mcal / h.
(2) If the temperature of the supplied hydrogen gas is set to 113 ° C. (6.1 MPa · G, 1342 Nm ³ / h), 42 Mcal / h of heating is required to raise the temperature to 172 ° C. of the reaction liquid temperature It becomes.
(3) In order to cool the gas discharged from the reactor (hydrogen gas containing saturated steam: 951 Nm ³ / h) to 40 ° C., 40 Mcal / h is required.
(4) In order to keep the reaction temperature stable at 170 ° C, the reaction liquid at 170 ° C (TPA 800 kg / h + water 7196 kg / h slurry) in the circulation line, the heat required for heating to 172 ° C is 366 Mcal / H.

(Heat balance: reference temperature is 170 ° C of reaction temperature)
Heat of reaction: 257Mcal / h
Exhaust hydrogen cooling: 40Mcal / h
Circulating reaction solution heating: 366 Mcal / h
Raw material hydrogen gas introduced cold energy: 42 42 Mcal / h
Excess hydrogen / steam evaporation latent heat + 40 ° C condensation water carrying cold energy: △ 115Mcal / h

(Cool heat that the feedstock should bring in)
From the above results, the amount of cold heat to be supplied to the reactor by the TPA / water slurry, which is the feedstock, is
(257 + 40 + 366)-(42 + 115) = 506 Mcal / h
Is calculated.
When the supply temperature (X ° C. in FIG. 2) corresponding to this heat amount is calculated in consideration of the above-described supply flow rate / mixing ratio and the specific heat of each component, the slurry supply temperature is calculated to be 113 ° C.

Example 3
It carried out like Example 1 except having changed the next point.
That is, 2399 kg / h of TPA at about 20 ° C. is mixed and dispersed in 5597 kg / h of water at 20 ° C. in a raw material preparation tank at normal temperature to prepare a slurry having a TPA concentration of 30% by weight (TPA / water (weight Ratio) = 30/70). This slurry is pressurized with hydrogen to 6.1 MPa · G (gauge pressure, the same applies hereinafter), and supplied at 7996 kg / h using a multi-tube heat exchanger provided in the middle of the slurry transfer piping at 58 ° C. The temperature is adjusted and then fed to a stirred reactor maintained at 170.degree.
While flowing the catalyst (Pd / C catalyst) supported by palladium on activated carbon in the reactor so as to be 2% by weight, the inside of the stirring tank is maintained at 6.1 MPa · G, and hydrogen of 128 ° C. (6. 1 MPa · G) is supplied to the reactor at 3990 Nm ³ / h. While filtering the Pd / C catalyst, the reaction product solution is continuously removed from the reactor at a rate of 161924 kg / h and hydrogen gas containing saturated steam at a rate of 2391 Nm ³ / h, and 95% (153,836 kg / h) of the reactor is removed. An aqueous solution of CHDA is obtained at a production rate of 8088 kg / h, in which the aromatic nucleus of TPA is hydrogenated while being circulated to the

The raw material slurry supply temperature (58 ° C.) at this time is estimated and determined as follows. The outline of the calculation procedure is described below.
(1) From the TPA supply amount (2399 kg / h) and the reaction conditions (reaction temperature of 170 ° C., 6.1 MPa · G) in the operation of the above example, the calorific value by hydrogenation is 257 Mcal / h.
(2) If the temperature of the supplied hydrogen gas is set to 128 ° C. (6.1 MPa · G, 3990 Nm ³ / h), heating of 56 Mcal / h is necessary to raise the temperature of the reaction liquid to 172 ° C. It becomes.
(3) In order to cool the gas discharged from the reactor (hydrogen gas containing saturated steam: 2391 Nm ³ / h) to 40 ° C., 122 Mcal / h is required.
(4) In order to keep the reaction temperature stable at 170 ° C, the reaction liquid at 170 ° C (TPA 2399 kg / h + water 5597 kg / h slurry) in the circulation line, heat quantity required for heating to 172 ° C is 324Mcal / H.

(Heat balance: reference temperature is 170 ° C of reaction temperature)
Heat of reaction: 760Mcal / h
Exhaust hydrogen cooling: 122Mcal / h
Circulating reaction solution heating: 324 Mcal / h
Raw material hydrogen gas introduced cold energy: 56 56 Mcal / h
Excess hydrogen / steam evaporation latent heat + 40 ° C condensation water carrying cold: 349 349Mcal / h

(Cool heat that the feedstock should bring in)
From the above results, the amount of cold heat to be supplied to the reactor by the TPA / water slurry, which is the feedstock, is
(760 + 122 + 324)-(56 + 349) = 801 Mcal / h
Is calculated.
When the supply temperature (X ° C. in FIG. 2) corresponding to this heat amount is calculated in consideration of the above-described supply flow rate / mixing ratio and the specific heat of each component, the slurry supply temperature is calculated to be 58 ° C.

<Confirmation of result>
As described above, a raw material to be supplied in a method of subjecting an aromatic polyvalent carboxylic acid to nuclear hydrogenation in an aqueous medium by using the method of the present invention to continuously produce a corresponding alicyclic polyvalent carboxylic acid The reaction temperature can be controlled by adjusting the temperature of (1), and the alicyclic polyvalent carboxylic acid can be stably produced with simple equipment.

  Although the invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application (Japanese Patent Application No. 2014-035826) filed on February 26, 2014, the contents of which are incorporated herein by reference.

  According to the present invention, in the method of subjecting an aromatic polyvalent carboxylic acid to nuclear hydrogenation in an aqueous medium to continuously produce the corresponding alicyclic polyvalent carboxylic acid, the heat removal performance of the reaction heat is the influence of the deposit etc. Thus, the present invention provides a method capable of controlling the temperature of the reactor, which can keep the reaction stable and does not require additional heat removal equipment inside the reactor.

1: Raw material preparation tank 2: Reactor 3: Hydrogen boost compressor 4: Raw material temperature controller (heat exchanger)
5: Pump 6: Filter module

Claims (6)

In the method of hydrogenating the aromatic nucleus of an aromatic polyvalent carboxylic acid in an aqueous medium and continuously producing the corresponding alicyclic polyvalent carboxylic acid, the temperature of the raw material mixture supplied to the reactor is 1) The manufacturing method of the alicyclic polyhydric carboxylic acid which controls reaction temperature by adjusting according to-3) .
1) Calculate the heat of reaction generated per unit time based on the supply amount of raw materials and the reaction conditions,
2) The temperature at which the reaction system rises due to the reaction is estimated by dividing this by the specific heat of the mixture of the product and the solvent,
3) Adjust the temperature of the raw material mixture from the heat capacity of the raw material mixture of the raw material component supplied into the system so as to meet the above temperature rise   The method for producing an alicyclic polyvalent carboxylic acid according to claim 1, wherein the temperature of the raw material mixture supplied to the reactor is a temperature that can be compensated by the heat of reaction with respect to the reaction temperature.   The mixing ratio of the aromatic polyvalent carboxylic acid to the aqueous medium in the raw material mixture is in the range of 5/95 to 50/50 as a weight ratio of aromatic polyvalent carboxylic acid / aqueous medium. The manufacturing method of the alicyclic polyhydric carboxylic acid as described in-.   The alicyclic polybasic resin according to any one of claims 1 to 3, wherein the reaction temperature is 100 ° C to 200 ° C, and the temperature of the raw material mixture supplied to the reactor is 40 ° C to 120 ° C lower than the reaction temperature. Method of producing carboxylic acid.   The manufacturing method of the alicyclic polyhydric carboxylic acid of any one of Claims 1-4 which control of reaction temperature is performed by the temperature of the raw material mixture supplied to a reactor.   The material temperature regulator provided between the material preparation tank or the material preparation tank and the reactor is used to adjust the temperature of the material mixture supplied to the reactor according to any one of claims 1 to 5. Process for producing alicyclic polyvalent carboxylic acid.