Preparation method of 1, 4-cyclohexanedicarboxylic acid

Abstract

The invention discloses a preparation method of 1, 4-cyclohexanedicarboxylic acid, and relates to the technical field of organic synthesis.The preparation method comprises the steps that after a terephthalic acid solution and an activated Pd-Pt / C bimetallic catalyst are added into a high-pressure reaction kettle, nitrogen and hydrogen are sequentially introduced for atmosphere replacement; introducing hydrogen into the high-pressure reaction kettle subjected to atmosphere replacement, stirring, and carrying out preliminary hydrogenation reaction on benzene rings of terephthalic acid to generate an intermediate cyclohexene dicarboxylic acid; increasing the pressure of the hydrogen and synchronously raising the temperature to carry out deep hydrogenation reaction until the pressure in the high-pressure reaction kettle is not reduced any more, and terminating the reaction; after the reaction is ended, cooling and collecting to obtain a 1, 4-cyclohexanedicarboxylic acid crude reaction solution; and treating the 1, 4-cyclohexanedicarboxylic acid crude reaction liquid to obtain the 1, 4-cyclohexanedicarboxylic acid. The invention provides a process which is high in trans selectivity, stable in process and excellent in economical efficiency, and efficient preparation of the high trans-1, 4-cyclohexanedicarboxylic acid is realized through gradient reaction condition regulation and catalyst optimization.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and more specifically to a method for preparing 1,4-cyclohexanedicarboxylic acid. Background Technology

[0002] 1,4-Cyclohexanedicarboxylic acid is a core monomer for the preparation of high-end polyesters and weather-resistant coatings. The content of its trans isomer is a key indicator that determines the melting point, mechanical properties and chemical stability of downstream polymers.

[0003] Currently, the mainstream industrial method for preparing 1,4-cyclohexanedicarboxylic acid is the aqueous hydrogenation of terephthalic acid. However, the existing process has significant drawbacks in terms of product performance, catalyst life, and production economics, as detailed below: 1) Low selectivity of trans isomers: Traditional processes use a single reaction temperature and pressure condition of 140~160℃ and 3~5MPa, making it difficult to precisely control the stereoselectivity of the benzene ring hydrogenation process. The content of trans-1,4-cyclohexanedicarboxylic acid in the final product is only 70~85%, which cannot meet the application technology requirements of high-end materials.

[0004] 2) Poor catalyst stability: The catalysts commonly used in existing processes include single-metal Pd / C catalysts and Pd-Pt-Zn multi-metal modified catalysts as described in Chinese patent document "CN105582926A". These catalysts are prone to activity decay during the reaction due to carbon deposition and metal particle agglomeration. The catalytic activity decreases significantly after a single use, and the number of cycles is less than 3, which greatly increases the cost of consumables in the production process.

[0005] 3) Insufficient economic efficiency for industrial production: Due to the high proportion of cis isomers in the products of existing patents and traditional processes, multiple recrystallization processes are required for purification, such as the melt isomerization-recrystallization combined process disclosed in Chinese patent document "CN1608042A". This type of purification method not only causes the loss of target product yield, but also significantly increases production energy consumption and wastewater discharge, reducing the economic efficiency of industrial production of 1,4-cyclohexanedicarboxylic acid.

[0006] In summary, developing a process for the aqueous hydrogenation of terephthalic acid to prepare 1,4-cyclohexanedicarboxylic acid that combines the advantages of high trans selectivity, recyclable catalyst, and low cost is of great significance for promoting the large-scale application of 1,4-cyclohexanedicarboxylic acid. Summary of the Invention

[0007] The purpose of this invention is to address the problem of poor trans isomer formation in existing aqueous hydrogenation processes for preparing 1,4-cyclohexanedicarboxylic acid. This invention provides a method for preparing 1,4-cyclohexanedicarboxylic acid.

[0008] To achieve the above objectives, the present invention specifically adopts the following technical solution: A method for preparing 1,4-cyclohexanedicarboxylic acid includes the following steps: S1. Terephthalic acid is treated to obtain a terephthalic acid solution, and the Pd-Pt / C bimetallic catalyst is activated to obtain the activated Pd-Pt / C bimetallic catalyst. S2. After adding terephthalic acid solution and activated Pd-Pt / C bimetallic catalyst to the high-pressure reactor, nitrogen and hydrogen are introduced sequentially for atmosphere replacement. S3. Hydrogen gas is introduced into the high-pressure reactor after the atmosphere replacement is completed and the mixture is stirred to carry out a preliminary hydrogenation reaction of the benzene ring of phthalic acid to generate the intermediate cyclohexene dicarboxylic acid; then, the hydrogen pressure is increased and the temperature is increased simultaneously to carry out a deep hydrogenation reaction until the pressure in the high-pressure reactor no longer decreases and the reaction is terminated; after the reaction is terminated, the mixture is cooled and collected to obtain the crude reaction solution of 1,4-cyclohexene dicarboxylic acid. S4. The crude reaction solution of 1,4-cyclohexanedicarboxylic acid was treated to obtain 1,4-cyclohexanedicarboxylic acid.

[0009] Preferably, the specific method for treating terephthalic acid to obtain a terephthalic acid solution includes: Add terephthalic acid to deionized water and heat to 90±10℃ while stirring to dissolve; After adding activated carbon for decolorization for 1 hour, the solution was filtered to obtain the filtrate. After the filtrate was cooled to 25°C, it was crystallized for 8 hours. Then, it was centrifuged and vacuum dried at 80°C to obtain purified terephthalic acid with a purity of ≥99.5% and a particle size of ≤100 mesh. The purified terephthalic acid and deionized water were mixed, and sodium carbonate was added to adjust the pH of the system to 5-6. The mixture was then heated to 85°C and stirred for 30 minutes to obtain a terephthalic acid solution.

[0010] Preferably, the activated carbon has a mass of 0.5% of the mass of terephthalic acid.

[0011] Preferably, the atomic ratio of Pd:Pt in the Pd-Pt / C bimetallic catalyst is 3~8:1, the total metal loading is 1~15%, and the mass of the Pd-Pt / C bimetallic catalyst is 1~10% of the mass of terephthalic acid.

[0012] Preferably, the specific method for activating the Pd-Pt / C bimetallic catalyst to obtain the activated Pd-Pt / C bimetallic catalyst includes: The Pd-Pt / C bimetallic catalyst was placed in a fixed-bed activation furnace and hydrogen gas was introduced. After activation by heating, the catalyst was cooled to room temperature to obtain the activated Pd-Pt / C bimetallic catalyst.

[0013] Preferably, the activation temperature for activating the Pd-Pt / C bimetallic catalyst is 150~250℃, the activation time is 1~5h, and the pressure is 0.5~15MPa.

[0014] Preferably, in step S2, nitrogen and hydrogen are replaced 1 to 5 times each, with a pressure of 0.1 to 1 MPa each time and a pressure holding time of 5 to 20 minutes.

[0015] Preferably, the specific method for collecting the crude 1,4-cyclohexanedicarboxylic acid reaction solution by cooling after the reaction is terminated includes: Stop heating and cool to 95°C, then filter through the filter in the high-pressure reactor to obtain crude 1,4-cyclohexanedicarboxylic acid reaction solution; Among them, the catalyst is recovered and reused.

[0016] Preferably, the specific method for treating the crude 1,4-cyclohexanedicarboxylic acid reaction solution to obtain 1,4-cyclohexanedicarboxylic acid includes: The crude reaction solution of 1,4-cyclohexanedicarboxylic acid was pumped into a vacuum distillation column, concentrated under reduced pressure, cooled and crystallized, and then centrifuged to obtain the crude product of 1,4-cyclohexanedicarboxylic acid. The crude 1,4-cyclohexanedicarboxylic acid product was dissolved in deionized water by heating, and then activated carbon was added for decolorization before filtration. The filtrate was subjected to cooling crystallization and centrifugation to obtain refined crystals; The purified crystals were vacuum dried to obtain 1,4-cyclohexanedicarboxylic acid.

[0017] Preferably, the reaction temperature for vacuum concentration is 60-80°C, and the mass ratio of the crude 1,4-cyclohexanedicarboxylic acid product to deionized water is 1:6-10.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By employing a gradient reaction strategy of low-temperature, low-pressure initial hydrogenation followed by high-temperature, high-pressure stereoisomerization, coupled with a Pd-Pt / C bimetallic synergistic catalyst, the stereoselectivity of benzene ring hydrogenation can be precisely controlled. This significantly increases the content of trans-1,4-cyclohexanedicarboxylic acid in the product from 70-85% in traditional processes to ≥90%, with a maximum of 92.5%. This quality of 1,4-cyclohexanedicarboxylic acid eliminates the need for multiple purification processes, directly meeting the requirements for preparing high-end polyester materials and effectively simplifying the production process.

[0019] 2. After five cycles, the selectivity of trans-1,4-cyclohexanedicarboxylic acid can still be maintained above 82.5%, and the catalytic activity retention rate is always >90%. Compared with traditional single-metal Pd / C catalysts that are recycled less than three times, the effective number of cycles is increased by more than 1 times, which significantly reduces the cost of catalyst consumables. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The materials and instruments used in the following examples are all commercially available.

[0022] A method for preparing 1,4-cyclohexanedicarboxylic acid includes steps S1 to S4.

[0023] S1. Terephthalic acid is treated to obtain a terephthalic acid solution. Specifically, industrial-grade terephthalic acid is added to deionized water, heated to 90±10℃ and stirred to dissolve, wherein the mass ratio of terephthalic acid to deionized water is 1:10~20; activated carbon is added for decolorization for 1 hour, and then filtered to obtain a filtrate; the filtrate is cooled to 25℃ and crystallized for 8 hours, and then centrifuged and vacuum dried at 80℃ to obtain refined terephthalic acid with a purity ≥99.5% and a particle size ≤100 mesh; wherein the mass of activated carbon is 0.5% of the mass of terephthalic acid; the refined terephthalic acid and deionized water are mixed, and sodium carbonate is added to adjust the pH of the system to 5~6, heated to 85℃ and stirred for 30 minutes to obtain a terephthalic acid solution.

[0024] The Pd-Pt / C bimetallic catalyst was activated to obtain the activated Pd-Pt / C bimetallic catalyst. Specifically, the Pd-Pt / C bimetallic catalyst was placed in a fixed-bed activation furnace, hydrogen gas was introduced, and the catalyst was activated by heating and then cooled to room temperature to obtain the activated Pd-Pt / C bimetallic catalyst. The activation temperature was 150~250℃, the activation time was 1~5h, and the pressure was 0.5~15MPa. The atomic ratio of Pd:Pt in the Pd-Pt / C bimetallic catalyst was 3~8:1, the total metal loading was 1~15%, and the mass of the Pd-Pt / C bimetallic catalyst was 1~10% of the mass of terephthalic acid.

[0025] It is important to note that the flow rate of hydrogen gas during activation needs to be kept stable to avoid temperature fluctuations that could cause metal particles to agglomerate.

[0026] S2. After adding terephthalic acid solution and activated Pd-Pt / C bimetallic catalyst to the high-pressure reactor, close the lid of the high-pressure reactor and sequentially introduce nitrogen and hydrogen gas for atmosphere replacement; nitrogen gas replaces the air in the high-pressure reactor. Nitrogen and hydrogen gas are each used for replacement 1-5 times, with each replacement at a pressure of 0.1-1 MPa and a holding time of 5-20 minutes.

[0027] S3. Hydrogen gas is introduced into the high-pressure reactor after atmosphere replacement and stirred. Under the conditions of pressure of 1~6MPa, reaction temperature of 100~150℃ and reaction time of 1~5h, the initial hydrogenation reaction of the benzene ring of terephthalic acid produces the intermediate cyclohexene dicarboxylic acid. Then, the hydrogen pressure is increased and the temperature is increased simultaneously to carry out a deep hydrogenation reaction until the pressure in the high-pressure reactor no longer decreases, at which point the reaction is terminated. During this process, the pressure is 2~10MPa, the reaction temperature is 120~200℃, the molar ratio of hydrogen to terephthalic acid is maintained at 5~20:1, and the reaction continues for 1~5h. The hydrogen pressure was increased at a rate of 0.5 ± 0.3 MPa / h, and the temperature was increased at a rate of 2 ~ 10 °C / min. After the reaction was terminated, the temperature was lowered to 95 °C to collect the crude 1,4-cyclohexanedicarboxylic acid reaction solution. The specific method for collecting the crude 1,4-cyclohexanedicarboxylic acid reaction solution after the reaction was terminated included: stopping the heating and cooling to 95 °C, and filtering the solution through a filter in a high-pressure reactor to obtain the crude 1,4-cyclohexanedicarboxylic acid reaction solution. The catalyst was washed twice with deionized water and recycled. The catalyst can be recycled more than 5 times.

[0028] It is important to note that the hydrogen replenishment rate must be strictly controlled during the hydrogenation reaction to avoid excessively high local hydrogen concentrations that could lead to catalyst deactivation.

[0029] S4. The crude reaction solution of 1,4-cyclohexanedicarboxylic acid is processed to obtain 1,4-cyclohexanedicarboxylic acid. Specifically, the crude reaction solution of 1,4-cyclohexanedicarboxylic acid is pumped into a vacuum distillation column, concentrated under reduced pressure to a mass concentration of 35%, and then subjected to cooling crystallization, centrifugation, purification, and drying to obtain crude 1,4-cyclohexanedicarboxylic acid product. The crude 1,4-cyclohexanedicarboxylic acid product is added to deionized water, heated to dissolve, and then decolorized with activated carbon and filtered. The filtrate is subjected to cooling crystallization and centrifugation to obtain purified crystals. The purified crystals are then vacuum dried to obtain 1,4-cyclohexanedicarboxylic acid, with a trans content ≥90%, purity ≥99.8%, and total yield ≥98%. The reaction temperature for vacuum concentration is 60~80℃, and the mass ratio of crude 1,4-cyclohexanedicarboxylic acid product to deionized water is 1:6~10.

[0030] It should be noted that when crystallizing after concentrating to a mass concentration of 35% under reduced pressure, the cooling rate should not be too fast, otherwise fine crystals will easily form, increasing the difficulty of centrifugal separation.

[0031] The present invention will now be described with reference to specific embodiments.

[0032] Example 1 The preparation method of 1,4-cyclohexanedicarboxylic acid in this embodiment adopts the following steps: S1. Raw material pretreatment: Take 200g of industrial grade terephthalic acid, add 2000g of deionized water, dissolve at 90℃, add 1g of activated carbon for decolorization for 1h, and filter while hot; cool the filtrate to 25℃ and crystallize for 8h, centrifuge and dry to obtain 166g of purified terephthalic acid with a purity of 99.6% and a particle size of 80 mesh; prepare 2490g of terephthalic acid solution with a mass ratio of terephthalic acid to deionized water of 1:15, add sodium carbonate to adjust the pH to 5.5, and stir for 30min at 85℃ to dissolve; take 3.32g of Pd-Pt / C catalyst, where the atomic ratio of Pd:Pt is 5:1 and the total metal loading is 5%, and activate it for 2h in a hydrogen atmosphere at 200℃ and 1MPa for later use; S2. Gradient hydrogenation reaction: Terephthalic acid solution and activated Pd-Pt / C catalyst were added to a 5L titanium high-pressure reactor. Nitrogen and hydrogen were used to purge the reactor three times each, at 0.5 MPa and maintained for 5 min each time. Hydrogen was introduced to 3 MPa, and the temperature was increased to 120°C at a rate of 5°C / min. The reactor was stirred at 800 rpm for 1 h. The pressure was then increased to 4.5 MPa at a rate of 0.5 MPa / h and the temperature was increased to 150°C at a rate of 2°C / min. The molar ratio of hydrogen to terephthalic acid was maintained at 15:1 for 3 h. After the reaction was completed, the reactor was cooled to 95°C at a rate of 5°C / min. The catalyst was recovered by hot filtration to obtain crude 1,4-cyclohexanedicarboxylic acid reaction solution. S3. Post-treatment: The crude reaction solution of 1,4-cyclohexanedicarboxylic acid was concentrated to a concentration of 35% under conditions of -0.09 MPa and 80℃. It was then cooled to 25℃ at a rate of 1℃ / min and crystallized for 10 h. The crude product was obtained by centrifugation. The crude product was dissolved at a solid-liquid ratio of 1:8. After decolorization with 0.3% of the crude product mass of activated carbon, it was cooled to 10℃ for recrystallization. Then, it was vacuum dried at 85℃ for 6 h to obtain 168 g of 1,4-cyclohexanedicarboxylic acid. The trans content of 1,4-cyclohexanedicarboxylic acid was 92.5%, the purity was 99.9%, and the total yield was 97.8%.

[0033] First, this invention employs a gradient reaction strategy of low-temperature, low-pressure initial hydrogenation followed by high-temperature, high-pressure stereoisomerization, coupled with a Pd-Pt / C bimetallic synergistic catalyst. This allows for precise control of the stereoselectivity of benzene ring hydrogenation, significantly increasing the content of trans-1,4-cyclohexanedicarboxylic acid in the product from 70-85% in traditional processes to ≥90%, with a maximum of 92.5%. This quality of 1,4-cyclohexanedicarboxylic acid eliminates the need for multiple purification processes, directly meeting the requirements for preparing high-end polyester materials and effectively simplifying the production process.

[0034] Secondly, due to the technological advantage of high trans-selectivity, the number of product purification times is reduced from 3 times in the traditional process to 1 time, and the total yield is increased to ≥98%. At the same time, the aqueous solvent used in the reaction can be 100% recycled, and the recycling of the catalyst further reduces the consumption cost of precious metals.

[0035] Finally, the entire preparation process of this invention is free of organic solvents, which reduces the generation of organic pollutants from the source and reduces wastewater discharge by 30% compared with traditional processes. In addition, the amount of activated carbon used in the refining process is reduced by 50%, and the amount of solid waste generated is reduced by 25%. All environmental protection indicators meet the relevant national clean production standards and have good environmental friendliness.

[0036] Example 2 In this embodiment, the catalyst recovered in Example 1 was directly reused. The reaction conditions were exactly the same as in Example 1. The reaction results after the first to fifth uses were recorded. The reaction results are shown in Table 1.

[0037] Table 1 Reaction Results As shown in Table 1, after the Pd-Pt / C catalyst is recycled 5 times, the selectivity of trans-1,4-cyclohexanedicarboxylic acid can still be maintained above 82.5%, and the catalytic activity retention rate is always >90%. Compared with the traditional single metal Pd / C catalyst that is recycled less than 3 times, its effective number of cycles is increased by more than 1 times, which significantly reduces the cost of catalyst consumables.

[0038] Comparative Example 1 This comparative example uses a single reaction condition, i.e., without a gradient hydrogenation reaction. Details are as follows: 166g of industrial-grade terephthalic acid was added to deionized water to prepare a solution of 2490g. Sodium carbonate was added to adjust the pH to 5.5, and then 3.32g of Pd-Pt / C catalyst was added. After displacement in a high-pressure reactor, the reaction was carried out directly at 4.5MPa and 150℃ for 4h. After the post-treatment in Example 1, 1,4-cyclohexanedicarboxylic acid was obtained. The trans content of 1,4-cyclohexanedicarboxylic acid was 78.3% and the total yield was 95.2%.

[0039] Comparative Example 2 This comparative example uses a single-metal Pd / C catalyst. Details are as follows: 166g of purified terephthalic acid was added to deionized water to prepare a solution of 2490g. Sodium carbonate was added to adjust the pH to 5.5, and then 3.32g of Pd / C catalyst was added. The total metal loading of the catalyst was 5%. The gradient hydrogenation process in Example 1 was used for the reaction. After post-treatment, the trans content of 1,4-cyclohexanedicarboxylic acid was 81.5%. After the catalyst was recycled 3 times, the trans content dropped to 68.2%, and the activity retention rate was only 65%.

[0040] As can be seen from the above, the preparation method of the present invention produces 1,4-cyclohexanedicarboxylic acid with high trans-selectivity, stable process and good economy. By controlling the gradient reaction conditions and optimizing the catalyst, the efficient preparation of high trans-1,4-cyclohexanedicarboxylic acid can be achieved.

[0041] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing 1,4-cyclohexanedicarboxylic acid, characterized in that, Includes the following steps: S1. Terephthalic acid is treated to obtain a terephthalic acid solution, and the Pd-Pt / C bimetallic catalyst is activated to obtain the activated Pd-Pt / C bimetallic catalyst. S2. After adding terephthalic acid solution and activated Pd-Pt / C bimetallic catalyst to the high-pressure reactor, nitrogen and hydrogen are introduced sequentially for atmosphere replacement. S3. Hydrogen gas is introduced into the high-pressure reactor after the atmosphere replacement is completed and the mixture is stirred to carry out a preliminary hydrogenation reaction of the benzene ring of phthalic acid to generate the intermediate cyclohexene dicarboxylic acid; then, the hydrogen pressure is increased and the temperature is increased simultaneously to carry out a deep hydrogenation reaction until the pressure in the high-pressure reactor no longer decreases and the reaction is terminated; after the reaction is terminated, the mixture is cooled and collected to obtain the crude reaction solution of 1,4-cyclohexene dicarboxylic acid. S4. The crude reaction solution of 1,4-cyclohexanedicarboxylic acid was treated to obtain 1,4-cyclohexanedicarboxylic acid.

2. The method for preparing 1,4-cyclohexanedicarboxylic acid according to claim 1, characterized in that, Specific methods for treating terephthalic acid to obtain a terephthalic acid solution include: Add terephthalic acid to deionized water and heat to 90±10℃ while stirring to dissolve; After adding activated carbon for decolorization for 1 hour, the solution was filtered to obtain the filtrate. After the filtrate was cooled to 25°C, it was crystallized for 8 hours. Then, it was centrifuged and vacuum dried at 80°C to obtain purified terephthalic acid with a purity of ≥99.5% and a particle size of ≤100 mesh. The purified terephthalic acid and deionized water were mixed, and sodium carbonate was added to adjust the pH of the system to 5-6. The mixture was then heated to 85°C and stirred for 30 minutes to obtain a terephthalic acid solution.

3. The method for preparing 1,4-cyclohexanedicarboxylic acid according to claim 2, characterized in that, The activated carbon has a mass of 0.5% of the mass of terephthalic acid.

4. The method for preparing 1,4-cyclohexanedicarboxylic acid according to claim 1, characterized in that, The atomic ratio of Pd:Pt in the Pd-Pt / C bimetallic catalyst is 3~8:1, the total metal loading is 1~15%, and the mass of the Pd-Pt / C bimetallic catalyst is 1~10% of the mass of terephthalic acid.

5. The method for preparing 1,4-cyclohexanedicarboxylic acid according to claim 1, characterized in that, The specific methods for activating Pd-Pt / C bimetallic catalysts to obtain activated Pd-Pt / C bimetallic catalysts include: The Pd-Pt / C bimetallic catalyst was placed in a fixed-bed activation furnace and hydrogen gas was introduced. After activation by heating, the catalyst was cooled to room temperature to obtain the activated Pd-Pt / C bimetallic catalyst.

6. The method for preparing 1,4-cyclohexanedicarboxylic acid according to claim 5, characterized in that, The activation temperature for the Pd-Pt / C bimetallic catalyst is 150~250℃, the activation time is 1~5h, and the pressure is 0.5~15MPa.

7. The method for preparing 1,4-cyclohexanedicarboxylic acid according to claim 1, characterized in that, In step S2, nitrogen and hydrogen are replaced 1 to 5 times each, with a pressure of 0.1 to 1 MPa each time and a holding time of 5 to 20 minutes.

8. The method for preparing 1,4-cyclohexanedicarboxylic acid according to claim 1, characterized in that, The specific method for collecting the crude 1,4-cyclohexanedicarboxylic acid reaction solution by cooling after the reaction is terminated includes: Stop heating and cool to 95°C, then filter through the filter in the high-pressure reactor to obtain crude 1,4-cyclohexanedicarboxylic acid reaction solution; Among them, the catalyst is recovered and reused.

9. The method for preparing 1,4-cyclohexanedicarboxylic acid according to claim 1, characterized in that, The specific methods for processing crude 1,4-cyclohexanedicarboxylic acid reaction solution to obtain 1,4-cyclohexanedicarboxylic acid include: The crude reaction solution of 1,4-cyclohexanedicarboxylic acid was pumped into a vacuum distillation column, concentrated under reduced pressure, cooled and crystallized, and then centrifuged to obtain the crude product of 1,4-cyclohexanedicarboxylic acid. The crude 1,4-cyclohexanedicarboxylic acid product was dissolved in deionized water by heating, and then activated carbon was added for decolorization before filtration. The filtrate was subjected to cooling crystallization and centrifugation to obtain refined crystals; The purified crystals were vacuum dried to obtain 1,4-cyclohexanedicarboxylic acid.

10. The method for preparing 1,4-cyclohexanedicarboxylic acid according to claim 9, characterized in that, The reaction temperature for vacuum concentration is 60~80℃, and the mass ratio of the crude 1,4-cyclohexanedicarboxylic acid product to deionized water is 1:6~10.

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