KR20150062911A - Preparation method of 1,4-cyclohexanedimethanol - Google Patents

Abstract

The present invention relates to a method for producing 1,4-cyclohexanedimethanol including the steps of: reducing terephthalic acid in the presence of a first metal catalyst including a palladium (Pd) compound; and reducing the reduced product of terephthalic acid in the presence of a second metal catalyst including a ruthenium (Ru) compound, a tin (Sn) compound, and a platinum (Pt) compound at a weight ratio of 1 : 0.8 or 1.2 : 0.2-0.6.

Description

PREPARATION METHOD OF 1,4-CYCLOHEXANEDIMETHANOL < RTI ID = 0.0 >

The present invention relates to a process for preparing 1,4-cyclohexanedimethanol. More particularly, the present invention relates to a process for producing 1,4-cyclohexanedimethanol with high purity, while simplifying the reaction process to increase the efficiency and economy of the reaction and minimize the by-products in a shorter time .

The process for preparing 1,4-cyclohexanedimethanol, which is conventionally known, It can be summarized as branches. One method is to synthesize 1,4-cyclohexanedimethanol via 1,4-dimethylcyclohexanedicarboxylate using dimethyl terephthalate under high temperature and high pressure conditions, and the other method uses terephthalic acid Thereby synthesizing 1,4-cyclohexane dicarboxylic acid and preparing 1,4-cyclohexanedimethanol from the 1,4-cyclohexane dicarboxylic acid.

However, the previously known method for preparing 1,4-cyclohexane dimethanol requires additional steps for removing or recovering the byproducts generated during the commercialization of the process or the catalysts used in each stage, and the resulting 1,4- The purity or reaction efficiency of hexane dimethanol was not so high.

Japanese Unexamined Patent Application, First Publication No. 2002-145824 discloses a process wherein a terephthalic acid is subjected to a hydrogenation reaction in the presence of a solvent and a palladium catalyst to obtain an intermediate 1,4-cyclohexane dimethanol, followed by a further hydrogenation reaction to obtain 1,4- A process for producing dimethanol is disclosed. However, such a preparation method lowers the selectivity of 1,4-cyclohexanedimethanol produced by-products to be finally prepared, and accordingly, an aliphatic higher alcohol such as 2-ethylhexanol is used as an extracting agent, A process of separating and recovering alcohol was required.

European Patent No. 0934920 discloses a preparation process for producing Raney catalyst to reduce terephthalic acid. However, the above-mentioned production method uses a catalyst which is not easy to use on a large scale, and a separate separation and recovery equipment process is further required by using dioxane together with water as a reaction solvent.

U.S. Patent No. 6,294,703 discloses a method for synthesizing 1,4-cyclohexanedimethanol with a complex catalyst comprising 1,4-cyclohexanedicarboxylic acid and ruthenium and tin supported thereon. According to the above synthesis method, the selectivity of 1,4-cyclohexane dimethanol to be finally produced can not be sufficiently secured, or a base must be used in the hydrogenation reaction, which may cause additional processes and costs, There is a problem.

Japanese Laid-Open Publication No. 2002-145824 European Registration No. 0934920 U.S. Patent No. 6294703

The present invention relates to a process for producing 1,4-cyclohexanedimethanol with high purity, while simplifying the reaction process to increase the efficiency and economy of the reaction and minimize the by-products in a shorter time.

In the present specification, there is provided a process for producing terephthalic acid, comprising: reducing terephthalic acid in the presence of a first metal catalyst comprising a palladium (Pd) compound; And reducing the reduction product of terephthalic acid in the presence of a second metal catalyst comprising a ruthenium (Ru) compound, a tin (Sn) compound and a platinum (Pt) compound in a weight ratio of 1: 0.8 to 1.2: 0.2 to 0.6 ≪ / RTI >; and a process for preparing 1,4-cyclohexanedimethanol.

The method for producing 1,4-cyclohexanedimethanol according to a specific embodiment of the present invention will be described in more detail below.

According to one embodiment of the invention, there is provided a process for producing terephthalic acid, comprising reducing terephthalic acid in the presence of a first metal catalyst comprising a palladium (Pd) compound; And reducing the reduction product of terephthalic acid in the presence of a second metal catalyst comprising a ruthenium (Ru) compound, a tin (Sn) compound and a platinum (Pt) compound in a weight ratio of 1: 0.8 to 1.2: 0.2 to 0.6 ; A process for the production of 1,4-cyclohexanedimethanol, comprising:

The inventors of the present invention have conducted research on a method for synthesizing a cycloalkane diol by direct hydrogenation of an aromatic dicarboxylic acid and found that when the first metal catalyst and the second metal catalyst are used, It is possible to reduce the aromatic dicarboxylic acid to a high efficiency without lowering it, and confirmed through experiments that the invention was completed.

Specifically, terephthalic acid is reduced using the first metal catalyst, and then a second metal catalyst containing a ruthenium (Ru) compound, a tin (Sn) compound and a platinum (Pt) When the reduction product is reduced again, terephthalic acid, which is a reactant, can mostly participate in the reaction and realize a high conversion rate, and it is possible to provide 1,4-cyclohexane dimethanol with high purity while minimizing by-products in a shorter time.

According to the process for producing 1,4-cyclohexane dimethanol in one embodiment, the by-product is not generated in the course of synthesizing 1,4-cyclohexane dimethanol from terephthalic acid, so that additional steps or steps for separating and recovering by-products are omitted And the purification process for increasing the purity can be minimized. In addition, the process for preparing 1,4-cyclohexane dimethanol in one embodiment can provide a relatively simplified reaction process design and can provide a high purity 1,4-cyclohexane dimethanol with a high yield in a shorter time The efficiency and economical efficiency of the entire manufacturing process can be improved.

As described above, in the method for producing 1,4-cyclohexanedimethanol in one embodiment, it may include reducing terephthalic acid in the presence of a first metal catalyst comprising a palladium (Pd) compound.

The benzene ring of terephthalic acid can be reduced through the first metal catalyst comprising the palladium (Pd) compound, thereby forming 1,4-cyclohexane dicarboxylic acid.

The first metal catalyst may comprise a palladium (Pd) compound immobilized on a support, wherein the first metal catalyst comprises 0.05 to 10 wt%, or 0.1 to 5 wt% of palladium; And a balance of the carrier. The palladium (Pd) compound means palladium metal itself, an organic salt of palladium or an inorganic salt of palladium.

In the step of reducing terephthalic acid, various reduction methods may be used. For example, the step of reducing terephthalic acid may include contacting the terephthalic acid and hydrogen gas.

In the step of reducing terephthalic acid, a method, a reaction condition, and an apparatus known to be used for the reduction reaction of aromatic carboxylic acid can be used without any limitation. For example, the step of reducing terephthalic acid may be performed at a temperature of 50 to 350 ° C, At a temperature of 100 ° C to 300 ° C and at a pressure of 30 bar to 150 bar, or 40 bar to 100 bar.

Specifically, the step of reducing the terephthalic acid may include introducing a hydrogen gas into the atmosphere of the first metal catalyst containing the palladium (Pd) compound and the reactor in which terephthalic acid is present, into an atmosphere of an inert gas such as nitrogen, Lt; / RTI >

In the step of reducing the terephthalic acid, 1 to 50 parts by weight or 3 to 40 parts by weight of the first metal catalyst may be used relative to 100 parts by weight of the terephthalic acid.

If the content or amount of the first metal catalyst is too low relative to the terephthalic acid, the efficiency of the reduction reaction may be decreased or the selectivity of 1,4-cyclohexanedimethanol may be lowered in the resultant reaction product, The production efficiency of the reaction apparatus is lowered and the efficiency of the apparatus or the energy consumption may become excessive when the final product is obtained and then separated / recovered. If the content or the amount of the first metal catalyst is too high relative to the terephthalic acid, since the by-products are excessively generated in the course of the reaction, it is not economical to perform additional steps in order to remove the by- The purity may be lowered.

Meanwhile, in the process for producing 1,4-cyclohexanedimethanol in one embodiment, the reduction product of terephthalic acid obtained through the reduction of terephthalic acid is reacted with a ruthenium (Ru) compound, a tin (Sn) compound and a platinum (Pt) In the weight ratio of 1: 0.8 to 1.2: 0.2 to 0.6 in the presence of a second metal catalyst.

The ruthenium contained in the second metal catalyst seems to convert the dicarboxylic acid into the primary alcohol. The tin seems to increase the selectivity of the resultant alcohol, and the platinum improves the activity of the catalyst It seems to play a role in suppressing side reactions.

Reduction of the reduction product of terephthalic acid containing 1,4-cyclohexane dicarboxylic acid in the presence of the second metal catalyst may result in the formation of reaction products including 1,4-cyclohexane dimethanol.

Wherein the second metal catalyst comprises a ruthenium (Ru) compound, a tin (Sn) compound and a platinum (Pt) compound in a weight ratio of 1: 0.8 to 1.2: 0.2 to 0.6 or 1: 0.9 to 1.1: 0.3 to 0.55 can do.

As can be seen from the following Examples and the like, by using a second metal catalyst containing ruthenium (Ru) compound, tin (Sn) compound and platinum (Pt) compound in the specified weight ratio, almost all of terephthalic acid used as a reactant Can participate in the reaction to realize a high conversion rate, and the selectivity of 1,4-cyclohexane dimethanol among the final products to be produced can be kept high.

The ruthenium (Ru) compound means the ruthenium metal itself, an organic salt of ruthenium or an inorganic salt of ruthenium. This also applies to tin (Sn) compounds and platinum (Pt) compounds.

Meanwhile, the second metal catalyst may include a ruthenium (Ru) compound, a tin (Sn) compound, and a platinum (Pt) compound fixed on a support. Specifically, the second metal catalyst may include 0.5 to 20 wt%, or 5 to 12 wt% of the ruthenium (Ru) compound. The tin (Sn) compound and the platinum (Pt) compound in the second metal catalyst may be determined as the content of the ruthenium compound and the weight ratio between the metal compounds.

If the content of the ruthenium compound, the tin (Sn) compound and the platinum (Pt) compound in the second metal catalyst is too low, the efficiency of the reduction reaction may be decreased or the reaction product obtained by seed production may not be 1,4-cyclohexanedimethanol And the yield of the unreacted carboxylic acid or anhydrous carboxylic acid may be lowered and the efficiency or the energy consumption may be deteriorated when the final reaction product is separated or recovered.

If the content of the ruthenium compound, the tin (Sn) compound and the platinum (Pt) compound in the second metal catalyst is too high, an additional reaction may occur excessively to form a primary alcohol form, The reaction yield may be lowered or the purity of the final reaction product may be lowered. In order to remove the produced by-products, the process of the process may be also economically deteriorated because several steps must be additionally performed.

In the step of reducing the reduction product of terephthalic acid, various reduction methods may be used. For example, reducing the reduction product of terephthalic acid may include contacting the reduction product of terephthalic acid with hydrogen gas.

In the step of reducing the reduction product of terephthalic acid, a method, reaction conditions and apparatus known to be used for the reduction reaction of an aromatic carboxylic acid can be used without any limit. For example, reduction of the reduction product of terephthalic acid may be performed by using 50 Deg.] C to 350 [deg.] C, or 100 [deg.] C to 300 < 0 > C and 30 to 150 bar, or 40 to 100 bar.

Specifically, the step of reducing the reduction product of terephthalic acid may be performed by introducing a hydrogen gas into the atmosphere of the inert gas such as nitrogen during the reduction reaction of the second metal catalyst and the terephthalic acid, Lt; / RTI >

In the step of reducing the reduction product of terephthalic acid, the reduction product of terephthalic acid may be used in an amount of 1 to 100 parts by weight, the second metal catalyst may be used in 1 to 50 parts by weight, or 3 to 40 parts by weight.

If the content or the amount of the second metal catalyst is too low relative to the reduction product of terephthalic acid, the efficiency of the reduction reaction may be decreased or the selectivity of 1,4-cyclohexane dimethanol may be lowered If the catalyst content is insufficient, the production efficiency of the reaction apparatus is lowered, and when the final product is obtained and then separated / recovered, the efficiency of the apparatus or energy consumption may become excessive.

If the content or amount of the second metal catalyst is too high as compared with the reduction product of terephthalic acid, the by-products are excessively generated in the course of the reaction. Therefore, it is not economical to perform the various steps in order to remove the by- The purity of the resultant product may be lowered.

Meanwhile, in the above process for producing 1,4-cyclohexane dimethanol, the step of reducing the terephthalic acid and the step of reducing the reduction product of terephthalic acid may be performed continuously. This means that 1,4-cyclohexane dimethanol can be formed from terephthalic acid through one process or a reaction process.

The step of reducing the terephthalic acid and the step of reducing the reduction product of terephthalic acid may be performed in one reactor. Means that the reduction of the terephthalic acid and the reduction of the reduction product of terephthalic acid are carried out in the same reactor without being separated in a separate process or transferring the reaction product.

On the other hand, carriers that can be contained in the first metal catalyst or the second metal catalyst can be used without limitation, and examples of the carrier include silica, alumina, zirconia, titanium dioxide ), Composite oxides such as silica-alumina, acidic activated carbon, zeolite, and the like can be used.

The acidic activated carbon refers to an activated carbon treated with an acid such as hydrochloric acid, sulfuric acid, phosphoric acid, perchloric acid, hypochlorous acid or the like by acid treatment of activated carbon. The activated carbon raw material denatured to the acidic activated carbon is not particularly limited, and examples thereof include wood, coconut shell, organic polymer, petroleum pitch and rice husk.

In the step of reducing the terephthalic acid and the step of reducing the reduction product of terephthalic acid, the reactants themselves may be directly reduced and the reduction reaction may occur in the presence of the reactants in the solvent.

The examples of the usable solvent are not limited to a great extent. For example, water or an organic solvent may be used. Examples of the organic solvent include aliphatic alcohols such as methanol, ethanol, propanol and cyclohexanol, aliphatic alcohols such as hexane and cyclohexane, Ethers such as hydrocarbons, diethyl ether, and tetrahydrofuran, or a mixture of two or more of them may be used.

The amount of the organic solvent to be used is not limited, and may be, for example, 10% to 1,000% by weight of the reaction product terephthalic acid and / or the reduction product of terephthalic acid.

In the process for producing 1,4-cyclohexane dimethanol according to one embodiment of the present invention, it is possible to further separate the used catalyst and purify the reaction product at the completion of the respective reduction reaction steps. Although the method which can be used for the purification is not limited to a great degree, it can be separated and purified by distillation, extraction, chromatography and the like.

According to the process for preparing 1,4-cyclohexane dimethanol provided herein, the reactants can participate in almost all the reactions to realize a high conversion rate, and can produce 1,4-cyclohexane dimethanol with a high purity while minimizing the by- Dimethanol. ≪ / RTI > The process for the production of 1,4-cyclohexane dimethanol enables a relatively simplified process design and provides high purity 1,4-cyclohexane dimethanol as a high yield in a shorter time, And economic efficiency can be improved.

In addition, according to the process for producing 1,4-cyclohexane dimethanol, it is possible to omit the additional process or step of separating and recovering the by-products by minimizing the by-products generated in the course of producing 1,4- And the purification process for increasing the purity can be omitted.

The invention will be described in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

< Example : Terephthalic acid 1,4- Using cyclodicarboxyl methanol  Direct conversion response>

In one reactor, terephthalic acid is used as a starting material and directly converted to cyclohexane dimethanol using a mixed catalyst of a Pd catalyst and a Ru-Sn-Pt catalyst.

[Production Example]

One. Production Example 1 : Preparation of first metal catalyst

10 g of activated carbon (Aldrich) and 60% nitric acid aqueous solution were charged in a 500 ml beaker, and the mixture was heated to 80 ° C and stirred.

After the stirring was completed, the activated carbon was washed with ion exchange water and dried under reduced pressure. After dissolving the activated carbon and palladium chloride in a 500 ml beaker in an aqueous hydrochloric acid solution, the water was evaporated off to obtain a residue. The obtained residue was dried under reduced pressure and then calcined at atmospheric conditions and at a temperature of 300 DEG C for 3 hours to obtain a first metal catalyst containing activated carbon carrying 0.5 wt% of palladium.

2. Production Example 2 : Preparation of Second Metal Catalyst

10 g of activated carbon (Aldrich) and 60% nitric acid aqueous solution were charged in a 500 ml beaker, and the mixture was heated to 80 ° C and stirred.

After the stirring was completed, the activated carbon was washed with ion exchange water and dried under reduced pressure. After dissolving ruthenium chloride trihydrate, tin chloride dihydrochloride and chloroplatinic acid together with the above activated carbon in a 500 ml beaker in an aqueous hydrochloric acid solution, the water was evaporated off and a residue was obtained. The obtained residue was dried under reduced pressure and then calcined at atmospheric conditions and at a temperature of 300 ° C. for 3 hours to prepare a second metal catalyst on which ruthenium (Ru), tin (Sn) and platinum (Pt) Respectively. (Ratios of ruthenium (Ru), tin (Sn) and platinum (Pt) are as shown in Table 1 below)

3. Manufacturing example  3: Preparation of second metal catalyst

(Ruthenium (Ru), tin (Sn) and platinum (Pt) were carried on a zeolite in the same manner as in Preparation Example 2, except that Y-zeolite (CBV780) Respectively.

4. Manufacturing example  4: Preparation of metal catalyst

A metal catalyst was prepared in the same manner as in Preparation Example 2 except that only ruthenium chloride trihydrate and chloroplatinic acid were dissolved in an aqueous hydrochloric acid solution without tin chloride dihydrate.

[ Example  And Comparative Example : 1,4- Of cyclohexanedimethanol  Produce]

Example  One

A 300-mL high-pressure reactor equipped with a stirrer was charged with 3.0 g of the Pd catalyst obtained in Preparation Example 1, 10.0 g of terephthalic acid and 100 g of ion-exchanged water. After the atmosphere in the high-pressure reactor was replaced with nitrogen at room temperature, hydrogen gas was introduced into the high-pressure reactor at a rate of 28 kg / cm &lt; 2 &gt; At this time, the stirring speed in the high-pressure reactor was fixed at 450 rpm, and the reaction was continued until there was no change in internal pressure.

After cooling the inside of the reactor to room temperature with no change in internal pressure of the high-pressure reactor, 3.0 g of the second metal catalyst obtained in Preparation Example 2 was added, and nitrogen in the reactor was replaced with nitrogen.

Then, hydrogen gas was injected into the reactor at a rate of 50 kg / cm &lt; 2 &gt;, and the internal temperature of the high-pressure reactor was increased to 230 &lt; The stirring speed in the high-pressure reactor was fixed at 450 rpm and the reaction was continued until there was no change in internal pressure. When the inside pressure of the high-pressure reactor is no longer changed, the interior of the reactor is cooled to 70 ° C, the reactor is disassembled, and the reaction product is collected.

The resultant reaction product was distilled off at 45 ° C using a concentrated rotary evaporator to obtain the final product (1,4-cyclohexanedimethanol). Then, the conversion of the reaction material (terephthalic acid) and the selectivity of cyclohexane dimethanol were measured using the gas chromatography on the obtained final product.

Specifically, the reaction product obtained by the reduction reaction (hydrogenation reaction) of the reaction material (terephthalic acid) was diluted with methanol so that the concentration of cyclodicarboxylate methanol was about 1 wt%. The selectivity of cyclohexane dimethanol was calculated by gas chromatography (GC) analysis of the diluted solution. The respective values were converted into molar ratios (%), and then [(cyclohexane dimethanol / product) * 100 ].

In the case of terephthalic acid, the conversion and selectivity of terephthalic acid remained after the reaction due to poor solubility in water and the remaining filtrate after catalyst filtration were calculated.

<Gas Chromatography (GC) Conditions>

1) Column: Agilent 19091J-413 (column length: 30 m inner diameter: 0.32 mm film thickness: 0.25 탆)

2) GC apparatus: gas chromatography model Agilent 7890

3) Carrier gas: helium

4) Detector: Flame ionization detector (FID)

Example  2

1,4-cyclohexanedimethanol was prepared in the same manner as in Example 1, except that the second metal catalyst obtained in Preparation Example 3 was used.

Example  3 to 5

Cyclohexanedimethanol was produced in the same manner as in Example 1 except that a second metal catalyst having a weight ratio of ruthenium (Ru), tin (Sn) and platinum (Pt) Respectively.

Example  6

Hydrogen gas was introduced into the reactor at a rate of 50 kg / cm &lt; 2 &gt;, the internal temperature of the high-pressure reactor was raised to 230 DEG C, and the internal pressure 1,4-cyclohexanedimethanol was prepared in the same manner as in Example 1, except that the hydrogenation reaction was carried out at 50 bar.

Comparative Example 1

3.0 g of the first metal catalyst obtained in Preparation Example 1, 3.0 g of the second metal catalyst obtained in Preparation Example 2, 10.0 g of terephthalic acid and 100 g of ion-exchanged water were charged in a 300-mL high-pressure reactor equipped with a stirrer. After the atmosphere in the high-pressure reactor was replaced with nitrogen at room temperature, hydrogen gas was introduced into the high-pressure reactor at a rate of 50 kg / cm 2, and the internal temperature of the high-pressure reactor was increased to 230 ° C.

The stirring speed in the high-pressure reactor was fixed at 450 rpm and the reaction was continued until there was no change in internal pressure. When the pressure inside the high-pressure reactor is no longer changed, the interior of the reactor is cooled to room temperature, the reactor is disassembled, and the reaction product is collected.

The resultant reaction product was distilled off at 45 ° C using a concentrated rotary evaporator to obtain the final product (1,4-cyclohexanedimethanol). Then, the conversion of the reaction material (terephthalic acid) and the selectivity of cyclohexane dimethanol were measured using the gas chromatography on the obtained final product.

Comparative Example 2

1,4-cyclohexanedimethanol was prepared in the same manner as in Comparative Example 1, except that 3.0 g of the first metal catalyst obtained in Preparation Example 1 was not used.

Comparative Example 3

1,4-cyclohexanedimethanol was prepared in the same manner as in Comparative Example 1, except that 3.0 g of the second metal catalyst obtained in Preparation Example 2 was not used.

Comparative Example 4

Except that 3.0 g of the first metal catalyst obtained in Preparation Example 1, 3.0 g of the metal catalyst obtained in Preparation Example 4, 10.0 g of terephthalic acid and 100 g of ion-exchanged water were charged in a 300-mL high-pressure reactor equipped with a stirrer, 1-cyclohexane dimethanol was prepared in the same manner as in 1).

The contents of the catalysts used in Examples 1 to 6 and Comparative Examples 1 to 4, the reaction conditions, and the results of the reaction (conversion of tetra-deacidification and selectivity of 1,4-cyclohexanedimethanol) are shown in Table 1 .

division Catalyst used The composition of the second metal catalyst [wt% in the supported catalyst]
(Ru: Sn: Pt) Reaction conditions Results (GC,%) Temperature
(° C) pressure
(bar) Conversion Rate Selectivity Example 1 1) Pd / C,
2) Ru-Sn-Pt / C 10: 10: 4 230 80 100 85 Example 2 1) Pd / C,
2) Ru-Sn-Pt / Zeolite 10: 10: 4 100 78 Example 3 1) Pd / C,
2) Ru-Sn-Pt / C 5: 5: 2 100 77 Example 4 1) Pd / C,
2) Ru-Sn-Pt / C 3: 3: 1 100 56 Example 5 1) Pd / C,
2) Ru-Sn-Pt / C 1: 1: 0.5 100 43 Example 6
1) Pd / C,
2) Ru-Sn-Pt / C 10: 10: 4 100 77 Example 6
1) Pd / C,
2) Ru-Sn-Pt / C 10: 10: 4 200 50 100 65 Comparative Example 1 1) Pd / C + Ru-Sn-Pt / C 10: 10: 4 230 80 43 none Comparative Example 2 1) Ru-Sn-Pt / C 10: 10: 4 53 none Comparative Example 3 1) Pd / C 77 none Comparative Example 4 1) Pd / C + Ru-Pt / C 10: 0: 4 41 none

As shown in Table 1, in Examples 1 to 6, the reaction product, terphthalic acid, was 100% converted, and the selectivity of 1,4-cyclohexanedimethanol was 56% or more or 70% . On the contrary, in Comparative Examples 1 to 4, the selectivity was significantly lowered, and it was confirmed that other by-products than the 1,4-cyclohexane dimethanol were produced in the final product.

Claims (12)

Reducing terephthalic acid in the presence of a first metal catalyst comprising a palladium (Pd) compound; And
Reducing the reduction product of terephthalic acid in the presence of a second metal catalyst comprising a ruthenium (Ru) compound, a tin (Sn) compound and a platinum (Pt) compound in a weight ratio of 1: 0.8 to 1.2: 0.2 to 0.6; Cyclohexanedimethanol. &Lt; / RTI &gt;
The method according to claim 1,
Wherein the step of reducing the terephthalic acid and the step of reducing the reduction product of terephthalic acid are carried out continuously.
The method according to claim 1,
Wherein the step of reducing the terephthalic acid and the step of reducing the reduction product of terephthalic acid are carried out in one reactor.
The method according to claim 1,
Wherein the first metal catalyst comprises a palladium (Pd) compound immobilized on a support,
Wherein the second metal catalyst comprises a ruthenium (Ru) compound, a tin (Sn) compound and a platinum (Pt) compound immobilized on a carrier.
5. The method of claim 4,
Wherein the second metal catalyst comprises 0.5 to 20 wt% of the ruthenium (Ru) compound.
5. The method of claim 4,
Wherein the second metal catalyst comprises 5 to 12 wt% of the ruthenium (Ru) compound.
The method according to claim 1,
Wherein reducing the terephthalic acid comprises contacting the terephthalic acid and hydrogen gas,
Wherein reducing the reduction product of terephthalic acid comprises contacting reduction product of terephthalic acid with hydrogen gas.
The method according to claim 1,
Wherein the step of reducing the terephthalic acid and the step of reducing the reduction product of terephthalic acid are carried out at 50 ° C to 350 ° C, respectively.
The method according to claim 1,
Wherein the step of reducing the terephthalic acid and the step of reducing the reduction product of terephthalic acid are each performed at a pressure of 30 bar to 150 bar.
The method according to claim 1,
Wherein 1 to 50 parts by weight of the first metal catalyst is used relative to 100 parts by weight of the terephthalic acid.
The method according to claim 1,
Wherein 1 to 50 parts by weight of the second metal catalyst is used relative to 100 parts by weight of the reduction product of terephthalic acid.
The method according to claim 1,
Wherein the second metal catalyst comprises a ruthenium (Ru) compound, a tin (Sn) compound and a platinum (Pt) compound in a weight ratio of 1: 0.9 to 1.1: 0.3 to 0.55 .