CN109305885B

CN109305885B - Synthesis method of 1, 4-cyclohexanedimethanol

Info

Publication number: CN109305885B
Application number: CN201710628277.2A
Authority: CN
Inventors: 司丹; 畅延青; 朱庆才; 张海涛
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2017-07-28
Filing date: 2017-07-28
Publication date: 2021-10-01
Anticipated expiration: 2037-07-28
Also published as: CN109305885A

Abstract

The invention relates to a synthesis method of 1, 4-cyclohexanedimethanol, and solves the problem of low yield in the preparation of 1, 4-cyclohexanedimethanol by hydrogenation of 1, 4-cyclohexanedicarboxylic acid in the prior art. The synthesis method by adopting 1, 4-cyclohexanedimethanol comprises the following steps: the method is characterized in that 1, 4-cyclohexane dicarboxylic acid and hydrogen react to obtain the 1, 4-cyclohexane dimethanol by taking water as a solvent in the presence of a hydrogenation catalyst, wherein the hydrogenation catalyst comprises a carrier, an active component and a cocatalyst, the carrier is active carbon, the active component comprises Ru, and the cocatalyst comprises Zn.

Description

Synthesis method of 1, 4-cyclohexanedimethanol

Technical Field

The invention relates to a synthesis method of 1, 4-cyclohexanedimethanol, a catalyst used by the method and a preparation method of the catalyst.

Background

1, 4-cyclohexanedimethanol (CHDM for short) is an important organic chemical raw material for producing polyester resin, the polyester resin produced by using the CHDM instead of ethylene glycol or other polyols has good thermal stability and thermoplasticity, can keep stable physical property and electrical property at higher temperature, and products prepared by the resin have good chemical resistance and environmental resistance. At present, dimethyl terephthalate is mainly used as a raw material in the process of industrially producing 1, 4-cyclohexanedimethanol, dimethyl 1, 4-cyclohexanedicarboxylate is prepared by benzene ring hydrogenation, and then 1, 4-cyclohexanedimethanol is prepared by ester hydrogenation. Due to the relatively low price and abundant sources of terephthalic acid (PTA), a trend has arisen in recent years to produce 1, 4-cyclohexanedimethanol starting from terephthalic acid. The process also usually comprises two steps, namely, firstly, the benzene ring is selectively hydrogenated to produce 1, 4-cyclohexanedicarboxylic acid, and then the 1, 4-cyclohexanedicarboxylic acid is hydrogenated to produce 1, 4-cyclohexanedimethanol. Considering the complexity of the two-step process, many researchers have conducted one-step hydrogenation of terephthalic acid to 1, 4-cyclohexanedimethanol. For example, JP200007596 filed in 1998 by Mitsubishi chemical corporation in Japan discloses a process for preparing CHDM by a one-step method under liquid phase conditions with PTA. The catalyst adopts a catalyst containing Ru and Sn components, and preferably also contains Pt, and the catalyst takes active carbon as a carrier. The embodiment discloses a specific reaction process, namely adding PTA, water and a catalyst in an autoclave under the protection of argon, raising the temperature to 230 ℃ when the hydrogen pressure is 1MPa, introducing hydrogen for reaction when the hydrogen pressure reaches 15MPa, taking out the reaction liquid after 4 hours of reaction, wherein the yield of CHDM is only 28.3%. Yoshinori Hara et al (The dry effect of platinum on carbon-supported ruthenium-tin catalysts used for hydrogenation reactions of carboxylic acids. Y. Hara, K. endo. applied catalysts A: General 239(2003) 181-195) used in The hydrogenation reaction using Ru-Sn-Pt/C catalyst, although The conversion of 1, 4-cyclohexanedicarboxylic acid reached 98%, The maximum yield of 1, 4-cyclohexanedimethanol was only 81.6%, and The yield of 1, 4-cyclohexanedimethanol was only 75% when The hydrogenation reaction was carried out using Ru-Sn-Re/C catalyst as described in US 6495730.

Disclosure of Invention

The invention aims to solve the problem of low yield of 1, 4-cyclohexanedimethanol prepared by hydrogenation of 1, 4-cyclohexanedicarboxylic acid in the prior art, and provides a synthesis method of 1, 4-cyclohexanedimethanol. The method has the characteristic of high yield of 1, 4-cyclohexanedimethanol generated by hydrogenation of 1, 4-cyclohexanedicarboxylic acid.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: the synthesis method of the 1, 4-cyclohexanedimethanol comprises the following steps: the method comprises the following steps of reacting 1, 4-cyclohexanedicarboxylic acid with hydrogen in the presence of a hydrogenation catalyst by using water as a solvent to obtain the 1, 4-cyclohexanedimethanol, wherein the hydrogenation catalyst comprises a carrier, an active component and a cocatalyst, the carrier is activated carbon, the active component comprises Ru, and the cocatalyst comprises Zn.

In the technical scheme, the preferable reaction temperature is 180-250 ℃; the reaction temperature is more preferably 200 to 230 ℃.

In the technical scheme, the preferable hydrogen pressure is 5-12 MPa; the hydrogen pressure is preferably 8-10 MPa.

In the technical scheme, the mass ratio of the 1, 4-cyclohexanedicarboxylic acid to the water is preferably 1 (1-10), and more preferably 1 (4-7).

In the technical scheme, the preferable reaction time is 1-5 hours.

In the technical scheme, the active component preferably comprises Re, and the Ru and the Re have a synergistic effect on the aspect of improving the yield of the 1, 4-cyclohexanedimethanol.

In the technical scheme, the active components preferably comprise Co, Ru and Co, and the active components have a synergistic effect on the aspect of improving the yield of the 1, 4-cyclohexanedimethanol.

In the technical scheme, the active component preferably comprises Re and Co at the same time, and the Re and Co have a synergistic effect on the aspect of improving the yield of the 1, 4-cyclohexanedimethanol.

In the technical scheme, the cocatalyst preferably comprises P, Zn and P, and the cocatalyst has a synergistic effect in the aspects of improving the yield of the 1, 4-cyclohexanedimethanol and improving the selectivity of the 1, 4-cyclohexanedimethanol.

In the above technical solution, it is most preferable that the active component simultaneously includes Ru, Re and Co, the Co-catalyst simultaneously includes Zn and P, and Ru, Re, Co, Zn and P have a combined promoting effect in increasing the yield of 1, 4-cyclohexanedimethanol and increasing the selectivity of 1, 4-cyclohexanedimethanol.

In the above technical solution, the content of Ru in the catalyst is preferably more than 0g/L and less than 10g/L, such as but not limited to 0.01g/L, 0.1g/L, 0.5g/L, 1g/L, 1.5g/L, 2g/L, 2.5g/L, 3g/L, 3.5g/L, 4g/L, 5g/L, 6g/L, 7g/L, 8g/L, 9 g/L. The content of Ru in the catalyst is more preferably 0.5-6 g/L.

In the above-mentioned embodiment, the Re content in the catalyst is preferably more than 0g/L and 10g/L or less, for example, but not limited to, 0.01g/L, 0.1g/L, 0.5g/L, 1g/L, 1.5g/L, 2g/L, 2.5g/L, 3g/L, 3.5g/L, 4g/L, 5g/L, 6g/L, 7g/L, 8g/L, 9 g/L. The Re content in the catalyst is more preferably 0.5-6 g/L.

In the above technical solution, the Co content in the catalyst is preferably more than 0g/L and less than 10g/L, such as but not limited to 0.01g/L, 0.1g/L, 0.5g/L, 1g/L, 1.5g/L, 2g/L, 2.5g/L, 3g/L, 3.5g/L, 4g/L, 5g/L, 6g/L, 7g/L, 8g/L, 9 g/L. The Co content in the catalyst is more preferably 0.5-6 g/L.

In the above technical solution, the Zn content in the catalyst is preferably more than 0 and less than 10g/L, such as but not limited to 0.01g/L, 0.1g/L, 0.5g/L, 1g/L, 1.5g/L, 2g/L, 2.5g/L, 3g/L, 3.5g/L, 4g/L, 5g/L, 6g/L, 7g/L, 8g/L, 9 g/L. The Zn content in the catalyst is more preferably 0.5-5 g/L.

In the above technical solution, the P content in the catalyst is preferably more than 0 and 10g/L or less, for example, but not limited to, 0.01g/L, 0.1g/L, 0.5g/L, 1g/L, 1.5g/L, 2g/L, 2.5g/L, 3g/L, 3.5g/L, 4g/L, 5g/L, 6g/L, 7g/L, 8g/L, 9 g/L. The content of P in the catalyst is more preferably 0.5-5 g/L.

The key point of the invention is the selection of active components and auxiliary agents, and the variety and index parameters of the active carbon are not particularly limited, and can be reasonably selected by a person skilled in the art. With respect to the activated carbon type, for example, but not limited to, the activated carbon may be coal, shell carbon, of which coconut shell carbon is a non-limiting example. Regarding the particle size of the activated carbon, for example, but not limited to, 10 to 200 mesh (for example, but not limited to, 20 mesh, 30 mesh, 40 mesh, 50 mesh, 60 mesh, 70 mesh, 80 mesh, 90 mesh, 100 mesh, 120 mesh, 150 mesh, 180 mesh, etc.); as for the specific surface of the activated carbon, for example, but not limited to, 0.01 to 1500m²In this range, 900m is given as a non-limiting example²/g、1000m²/g、1100m²/g、1200m²/g、1300m²/g、1400m²G,/g, etc.; as for the average pore volume of the activated carbon, for example, but not limited to, 0.1 to 0.7cm³In this range, by way of non-limiting example,/g0.1cm³/g、0.2cm³/g、0.3cm³/g、0.4cm³/g、0.6cm³/g、0.7cm³G,/etc. For the sake of comparability, the activated carbon in the specific embodiment of the invention is coconut shell carbon, the granularity is 60-80 meshes, and the specific surface is 1056m²Per g, average pore volume of 0.32cm³/g。

In the above technical scheme, the hydrogenation catalyst can be prepared by a method comprising the following steps:

a) mixing the solution of the compound of the active component and the compound of the cocatalyst element with the activated carbon;

b) reducing the active component elements in the compound of the active component into simple substances by using a reducing agent.

In the above technical solution, the reducing agent in step b) is preferably at least one of hydrogen, formaldehyde, hydrazine hydrate, sodium borohydride, formic acid or sodium formate. The specific reduction process conditions can be chosen reasonably by the person skilled in the art according to the objectives to be achieved in step b) and without any inventive effort. For example, when the reduction is performed by using a hydrogen-nitrogen mixed gas with a hydrogen volume concentration of 2-4%, the temperature is, for example, but not limited to, 150-300 ℃. The reduction time may be, for example, 1 to 5 hours.

The introduction of P can be any phosphorus-containing compound.

The key to the present invention is the choice of catalyst, which can be reasonably selected by one skilled in the art for the specific process and process conditions.

It can be seen from the data of the specific embodiment that when the catalyst of the present invention is used in the synthesis reaction, the conversion rate of the raw material 1, 4-cyclohexanedicarboxylic acid reaches 99.3%, the selectivity of the target product CHDM also reaches 96.5%, that is, the yield of CHDM reaches 95.8%, and a good technical effect is achieved.

Detailed Description

[ example 1 ]

Preparation of the catalyst

Adding RuCl₃·3H₂O and ZnCl₂Dissolving in water to obtain 1200 ml of impregnation solution containing 6g of Ru and 4g of Zn, and mixing the solutionMixing the impregnation liquid with 1L of activated carbon, impregnating for 24 hours, drying at 80 ℃ for 6 hours, and then reducing at 250 ℃ for 3 hours in hydrogen-nitrogen mixed gas (the volume concentration of hydrogen in the mixed gas is 3%) to obtain a catalyst finished product.

The ICP-AES analysis showed that the catalyst had a Ru content of 6g/L and a Zn content of 4 g/L.

Synthesis of 1, 4-cyclohexanedimethanol

Adding 150g of 1, 4-cyclohexanedicarboxylic acid and 600g of water into an autoclave, adding 50ml of the obtained catalyst, starting stirring, introducing nitrogen for three times, introducing hydrogen to increase the pressure of the hydrogen to 8.5MPa and keep the pressure stable, maintaining the reaction temperature at 230 ℃, and continuously introducing the hydrogen for reaction for 3 hours. After the reaction is finished, the catalyst is filtered off while the catalyst is hot, the reaction solution is respectively analyzed by liquid chromatography and gas chromatography, and the CHDA conversion rate, the CHDM selectivity and the CHDM yield are calculated.

For ease of comparison, the catalyst compositions and the results of the synthesis reactions are shown in Table 1.

[ example 2 ]

Preparation of the catalyst

Adding RuCl₃·3H₂O and Na₂HPO₄Dissolving in water to obtain 1200 ml of impregnation liquid containing 6g of Ru and 4g of P, mixing the impregnation liquid with 1L of activated carbon, impregnating for 24h, drying at 80 ℃ for 6 h, and then reducing at 250 ℃ for 3h in hydrogen and nitrogen mixed gas (the volume concentration of hydrogen in the mixed gas is 3%) to obtain a finished catalyst.

The ICP-AES analysis showed that the catalyst had a Ru content of 6g/L and a P content of 4 g/L.

Synthesis of 1, 4-cyclohexanedimethanol

[ example 3 ]

Preparation of the catalyst

Adding Recl₃·6H₂O and ZnCl₂Dissolving in water to obtain 1200 ml of impregnation liquid containing 6g of Re and 4g of Zn, mixing the impregnation liquid with 1L of activated carbon, impregnating for 24h, drying at 80 ℃ for 6 h, and then reducing at 250 ℃ for 3h in hydrogen and nitrogen mixed gas (the volume concentration of hydrogen in the mixed gas is 3%) to obtain a finished catalyst.

The catalyst had an Re content of 6g/L and a Zn content of 4g/L by ICP-AES analysis.

Synthesis of 1, 4-cyclohexanedimethanol

[ example 4 ]

Preparation of the catalyst

Adding Recl₃·6H₂O and Na₂HPO₄Dissolving in water to obtain 1200 ml of impregnation liquid containing 6g of Re and 4g of P, mixing the impregnation liquid with 1L of activated carbon, impregnating for 24h, drying at 80 ℃ for 6 h, and then reducing at 250 ℃ for 3h in hydrogen and nitrogen mixed gas (the volume concentration of hydrogen in the mixed gas is 3%) to obtain a finished catalyst.

The catalyst had an Re content of 6g/L and a P content of 4g/L by ICP-AES analysis.

Synthesis of 1, 4-cyclohexanedimethanol

[ example 5 ]

Preparation of the catalyst

Mixing of Co (OAc)₂·4H₂O and ZnCl₂Dissolving in water to obtain 1200 ml of impregnation liquid containing 6g of Co and 4g of Zn, mixing the impregnation liquid with 1L of activated carbon, impregnating for 24h, drying at 80 ℃ for 6 h, and reducing at 250 ℃ for 3h in hydrogen and nitrogen mixed gas (the volume concentration of hydrogen in the mixed gas is 3%) to obtain a finished catalyst.

The content of Co in the catalyst was 6g/L and the content of Zn was 4g/L by ICP-AES analysis.

Synthesis of 1, 4-cyclohexanedimethanol

[ example 6 ]

Preparation of the catalyst

Mixing of Co (OAc)₂·4H₂O and Na₂HPO₄Dissolving in water to obtain 1200 ml of impregnation solution containing 6g of Co and 4g of P, mixing the impregnation solution with 1L of activated carbon, impregnating for 24h, drying at 80 ℃ for 6 h, and then introducing mixed gas of hydrogen and nitrogen (mixed gas)The volume concentration of hydrogen in the gas is 3%) and is reduced for 3h at 250 ℃ to obtain the finished catalyst.

The content of Co in the catalyst was 6g/L and the content of P was 4g/L by ICP-AES analysis.

Synthesis of 1, 4-cyclohexanedimethanol

[ example 7 ]

Preparation of the catalyst

Adding RuCl₃·3H₂O、ReCl₃·6H₂O and ZnCl₂Dissolving in water to obtain 1200 ml of impregnation liquid containing 3g of Ru, 3g of Re and 4g of Zn, mixing the impregnation liquid with 1L of activated carbon, impregnating for 24h, drying at 80 ℃ for 6 h, and then reducing at 250 ℃ for 3h in hydrogen-nitrogen mixed gas (the volume concentration of hydrogen in the mixed gas is 3%) to obtain a finished catalyst.

By ICP-AES analysis, the content of Ru in the catalyst is 3g/L, the content of Re is 3g/L and the content of Zn is 4 g/L.

Synthesis of 1, 4-cyclohexanedimethanol

It can be seen from the comparison of example 7 with examples 1 and 3 that Ru and Re have a synergistic effect in increasing the yield of 1, 4-cyclohexanedimethanol.

[ example 8 ]

Preparation of the catalyst

Adding RuCl₃·3H₂O、ReCl₃·6H₂O and Na₂HPO₄Dissolving in water to obtain 1200 ml of impregnation liquid containing 3g of Ru, 3g of Re and 4g of P, mixing the impregnation liquid with 1L of activated carbon, impregnating for 24h, drying at 80 ℃ for 6 h, and then reducing at 250 ℃ for 3h in hydrogen-nitrogen mixed gas (the volume concentration of hydrogen in the mixed gas is 3%) to obtain a finished catalyst.

By ICP-AES analysis, the content of Ru in the catalyst is 3g/L, the content of Re is 3g/L and the content of P is 4 g/L.

Synthesis of 1, 4-cyclohexanedimethanol

As can be seen by comparing example 8 with examples 2 and 4, Ru and Re have a synergistic effect in increasing the yield of 1, 4-cyclohexanedimethanol.

[ example 9 ]

Preparation of the catalyst

Adding Recl₃·6H₂O、Co(OAc)₂·4H₂O and ZnCl₂Dissolving in water to obtain 1200 ml of impregnation solution containing 3g of Re, 3g of Co and 4g of Zn, mixing the impregnation solution with 1L of activated carbon, impregnating for 24h, drying at 80 ℃ for 6 h, and then carrying out hydrogen treatmentReducing the gas-nitrogen mixed gas (the volume concentration of hydrogen in the mixed gas is 3%) at 250 ℃ for 3h to obtain the catalyst finished product.

By ICP-AES analysis, the Re content in the catalyst was 3g/L, the Co content was 3g/L, and the Zn content was 4 g/L.

Synthesis of 1, 4-cyclohexanedimethanol

It can be seen from the comparison of example 9 with examples 3 and 5 that Re and Co have a synergistic effect in increasing the yield of 1, 4-cyclohexanedimethanol.

[ example 10 ]

Preparation of the catalyst

Adding Recl₃·6H₂O、Co(OAc)₂·4H₂O and Na₂Dissolving HPO4 in water to obtain 1200 ml of impregnation liquid containing 3g of Re, 3g of Co and 4g of P, mixing the impregnation liquid with 1L of activated carbon, impregnating for 24h, drying at 80 ℃ for 6 h, and then reducing at 250 ℃ for 3h in hydrogen-nitrogen mixed gas (the volume concentration of hydrogen in the mixed gas is 3%) to obtain a finished catalyst.

By ICP-AES analysis, the Re content in the catalyst was 3g/L, the Co content was 3g/L, and the P content was 4 g/L.

Synthesis of 1, 4-cyclohexanedimethanol

It can be seen from the comparison of example 10 with examples 4 and 6 that Re and Co have a synergistic effect in increasing the yield of 1, 4-cyclohexanedimethanol.

[ example 11 ]

Preparation of the catalyst

Adding RuCl₃·3H₂O、Co(OAc)₂·4H₂O and ZnCl₂Dissolving in water to obtain 1200 ml of impregnation liquid containing 3g of Ru, 3g of Co and 4g of Zn, mixing the impregnation liquid with 1L of activated carbon, impregnating for 24h, drying at 80 ℃ for 6 h, and reducing at 250 ℃ for 3h in hydrogen-nitrogen mixed gas (the volume concentration of hydrogen in the mixed gas is 3%) to obtain a finished catalyst.

By ICP-AES analysis, the content of Ru in the catalyst is 3g/L, the content of Co in the catalyst is 3g/L, and the content of Zn in the catalyst is 4 g/L.

Synthesis of 1, 4-cyclohexanedimethanol

As can be seen by comparing example 11 with examples 1 and 5, Ru and Co have a synergistic effect in increasing the yield of 1, 4-cyclohexanedimethanol.

[ example 12 ]

Preparation of the catalyst

Adding RuCl₃·3H₂O、Co(OAc)₂·4H₂O and Na₂HPO₄Dissolving in water to obtain 1200 ml of impregnation liquid containing 3g of Ru, 3g of Co and 4g of P, mixing the impregnation liquid with 1L of activated carbon, impregnating for 24h, drying at 80 ℃ for 6 h, and reducing at 250 ℃ for 3h in hydrogen-nitrogen mixed gas (the volume concentration of hydrogen in the mixed gas is 3%) to obtain a finished catalyst.

By ICP-AES analysis, the content of Ru in the catalyst is 3g/L, the content of Co in the catalyst is 3g/L, and the content of P in the catalyst is 4 g/L.

Synthesis of 1, 4-cyclohexanedimethanol

As can be seen by comparing example 12 with examples 2 and 6, Ru and Co have a synergistic effect in increasing the yield of 1, 4-cyclohexanedimethanol.

[ example 13 ]

Preparation of the catalyst

Adding RuCl₃·3H₂O、ReCl₃·6H₂O and ZnCl₂、Na₂HPO₄Dissolving in water to obtain 1200 ml of impregnation liquid containing 3g of Ru, 3g of Re, 3g of Zn and 1g of P, mixing the impregnation liquid with 1L of activated carbon, impregnating for 24h, drying at 80 ℃ for 6 h, and then reducing at 250 ℃ for 3h in hydrogen-nitrogen mixed gas (the volume concentration of hydrogen in the mixed gas is 3%) to obtain a finished catalyst.

By ICP-AES analysis, the content of Ru in the catalyst is 3g/L, the content of Re is 3g/L, the content of Zn is 3g/L and the content of P is 1 g/L.

Synthesis of 1, 4-cyclohexanedimethanol

As can be seen by comparing example 13 with examples 7 and 8, Zn and P have a synergistic effect in increasing the yield of 1, 4-cyclohexanedimethanol and increasing the selectivity of 1, 4-cyclohexanedimethanol.

[ example 14 ]

Preparation of the catalyst

Adding Recl₃·6H₂O、Co(OAc)₂·4H₂O and ZnCl₂、Na₂HPO₄Dissolving in water to obtain 1200 ml of impregnation liquid containing 3g of Re, 3g of Co, 3g of Zn and 1g of P, mixing the impregnation liquid with 1L of activated carbon, impregnating for 24h, drying at 80 ℃ for 6 h, and then reducing at 250 ℃ for 3h in hydrogen-nitrogen mixed gas (the volume concentration of hydrogen in the mixed gas is 3%) to obtain a finished catalyst.

By ICP-AES analysis, the Re content in the catalyst is 3g/L, the Co content is 3g/L, the Zn content is 3g/L, and the P content is 1 g/L.

Synthesis of 1, 4-cyclohexanedimethanol

It can be seen from the comparison of example 14 with examples 9 and 10 that Zn and P have a synergistic effect in increasing the yield of 1, 4-cyclohexanedimethanol and increasing the selectivity of 1, 4-cyclohexanedimethanol.

[ example 15 ]

Preparation of the catalyst

Adding RuCl₃·3H₂O、Co(OAc)₂·4H₂O and ZnCl₂、Na₂HPO₄Dissolving in water to obtain 1200 ml of impregnation liquid containing 3g of Ru, 3g of Co, 3g of Zn and 1g of P, mixing the impregnation liquid with 1L of activated carbon, impregnating for 24h, drying at 80 ℃ for 6 h, and then reducing at 250 ℃ for 3h in hydrogen-nitrogen mixed gas (the volume concentration of hydrogen in the mixed gas is 3%) to obtain a finished catalyst.

According to ICP-AES analysis, the content of Ru in the catalyst is 3g/L, the content of Co in the catalyst is 3g/L, the content of Zn in the catalyst is 3g/L, and the content of P in the catalyst is 1 g/L.

Synthesis of 1, 4-cyclohexanedimethanol

It can be seen from the comparison of example 15 with examples 11 and 12 that Zn and P have a synergistic effect in increasing the yield of 1, 4-cyclohexanedimethanol and increasing the selectivity of 1, 4-cyclohexanedimethanol.

[ example 16 ]

Preparation of the catalyst

Adding RuCl₃·3H₂O、ReCl₃·6H₂O、Co(OAc)₂·4H₂O and ZnCl₂Na2HPO4 solutionAdding water to obtain 1200 ml of impregnation liquid containing 2.5g of Re, 1g of Co, 3g of Zn and 1g of P, mixing the impregnation liquid with 1L of activated carbon, impregnating for 24 hours, drying at 80 ℃ for 6 hours, and then reducing at 250 ℃ for 3 hours in hydrogen and nitrogen mixed gas (the volume concentration of hydrogen in the mixed gas is 3%) to obtain a finished catalyst.

ICP-AES analysis shows that the catalyst has 2.5g/L of Ru, 2.5g/L of Re, 1g/L of Co, 3g/L of Zn and 1g/L of P.

Synthesis of 1, 4-cyclohexanedimethanol

In comparison with examples 1 to 15, it can be seen that Ru, Re, Co, Zn and P have mutually combined promoting effects in increasing the yield of 1, 4-cyclohexanedimethanol and increasing the selectivity of 1, 4-cyclohexanedimethanol.

TABLE 1

Claims

A method for synthesizing 1, 4-cyclohexanedimethanol, comprising the following steps: reacting 1, 4-cyclohexanedicarboxylic acid with hydrogen in the presence of a hydrogenation catalyst by using water as a solvent to obtain 1, 4-cyclohexanedimethanol, wherein the hydrogenation catalyst comprises a carrier, an active component and a cocatalyst, the carrier is activated carbon, the active component comprises Ru, Re and Co, and the cocatalyst comprises Zn;

wherein, the content of Ru is more than 0g/L and less than 10 g/L; the Re content is more than 0g/L and less than 10 g/L; the content of Co is more than 0g/L and less than 10 g/L; the Zn content is more than 0g/L and less than 10 g/L.
2. The method according to claim 1, wherein the reaction temperature is 180 to 250 ℃.
3. The synthesis method according to claim 1, wherein the hydrogen pressure is 5 to 12 MPa.
4. The method according to claim 1, wherein the mass ratio of 1, 4-cyclohexanedicarboxylic acid to water is 1 (1 to 10).
5. The method according to claim 1, wherein the reaction time is 1 to 5 hours.
6. The synthesis method according to claim 1, wherein the catalyst contains 0.5-6 g/L of Ru.
7. The synthesis method according to claim 1, wherein the Zn content in the catalyst is 0.5-5 g/L.
8. A synthesis method according to any one of claims 1 to 7, characterized in that the hydrogenation catalyst is prepared by the following steps:

a) mixing the solution of the compound of the active component and the compound of the cocatalyst element with the activated carbon;

b) reducing the active component elements in the compound of the active component into simple substances by using a reducing agent.