Method for purifying 1, 4-cyclohexanedimethanol composition

Abstract

The invention relates to a purification method of a 1, 4-cyclohexanedimethanol (CHDM) composition. More specifically, the present invention relates to a method for purifying CHDM capable of efficiently removing solvent water with low energy and separating high-purity CHDM.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2022-00570687 filed in the Korean Intellectual Property Office on May 10, 2022, the disclosure of which is incorporated herein by reference in its entirety.

[0003] The present invention relates to a method for purifying a 1,4-cyclohexanedimethanol (CHDM) composition, and more particularly to a method for purifying CHDM, which can efficiently remove water as a solvent with low energy and can separate high-purity CHDM. Background Art

[0004] 1,4-Cyclohexanedimethanol (CHDM) is widely used as a raw material for medicines, synthetic resins, synthetic fibers or dyes, especially as a raw material for environmentally friendly polyester - polyethylene terephthalate.

[0005] 1,4-cyclohexanedimethanol exists in the form of cis and trans stereoisomers. In order to obtain a higher quality product, the proportion of trans-1,4-cyclohexanedimethanol (trans-CHDM) is required to be higher than that of cis-CHDM.

[0006] Among the methods for producing 1,4-cyclohexanedimethanol, there is a method of first hydrogenating phthalate and converting it into 1,4-cyclohexanedicarboxylic acid (CHDA), and then hydrogenating CHDA and converting it into CHDM. This method uses a heterogeneous catalyst and consists of a two-step hydrogenation reaction.

[0007] The CHDM production process uses water as a solvent, wherein the phthalate esters used as the starting materials have low solubility in water, so after CHDM is produced, there is about 80% or more water in the reaction system. Since water is a solvent with a high specific heat capacity, it is very energy inefficient to remove water through a typical separation process. In addition, CHDM has hydroxyl groups and therefore exhibits high hydrophilicity to water. Therefore, when the solvent is removed from the CHDM crude product and CHDM is recovered, the CHDM concentration associated with water is likely to increase. If the CHDM concentration associated with water increases, CHDM loss will occur, which greatly reduces the economic feasibility of the process and also has a negative impact on the environment.

[0008] Therefore, there is a need to develop a process for effectively removing the solvent from the crude product obtained after CHDM production. Summary of the invention

[0009] Technical issues

[0010] In order to solve the above problems, the object of the present invention is to provide a method for purifying a 1,4-cyclohexanedimethanol composition, which can efficiently remove water as a solvent from a crude 1,4-cyclohexanedimethanol composition with low energy and has high purity due to low content of by-products and water.

[0011] Technical Solution

[0012] In order to achieve the above object, according to one aspect of the present invention, a method for purifying a 1,4-cyclohexanedimethanol composition is provided, comprising:

[0013] Step 1: A CHDM crude composition containing 1,4-cyclohexanedimethanol (CHDM), water and by-products is introduced into an FFE (falling film evaporator), a first stream containing water as a main component is evaporated at the upper part of the FFE, and a second stream containing CHDM as a main component is separated at the lower part of the FFE;

[0014] Step 2: sending the first stream to an absorber and recovering CHDM in the lower part of the absorber; and

[0015] Step 3: The stream discharged to the upper part of the absorber in step 2 is compressed using an MVR (mechanical vapor compressor) and used as a heat source for the FFE.

[0016] Beneficial Effects

[0017] The purification method of 1,4-cyclohexanedimethanol of the present invention has low energy consumption and high efficiency in removing solvent water, so high-quality 1,4-cyclohexanedimethanol can be produced at low cost.

[0018] In addition, according to the method for purifying a 1,4-cyclohexanedimethanol composition of the present invention, the contents of by-products and water are very low, so that high-purity 1,4-cyclohexanedimethanol can be provided, which is expected to improve physical properties when used as a polymer raw material. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram showing a method for purifying a 1,4-cyclohexanedimethanol composition according to an embodiment of the present invention.

[0020] Figure 2 Schematic diagram showing a method for purifying a 1,4-cyclohexanedimethanol composition according to a comparative example.

[0021] Figure 3 Schematic diagram showing a method for purifying a 1,4-cyclohexanedimethanol composition according to a comparative example. DETAILED DESCRIPTION

[0022] The technical terms used herein are only used to explain the exemplary embodiments and are not intended to limit the scope of the present disclosure. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "the" are intended to include plural forms. It should be understood that the terms "including", "comprising", "having" and the like are used herein to specify the presence of the features, integers, steps, components or combinations thereof, but do not exclude the presence or addition of one or more other features, integers, steps, components or combinations thereof.

[0023] Although the present disclosure may have various forms and various modifications may be made thereto, specific embodiments will be illustrated and explained in detail below. However, it is not intended to limit the present disclosure to specific disclosures, and it should be understood that the present disclosure includes all modifications, equivalent forms or alternative forms thereof without departing from the spirit and technical scope of the present disclosure.

[0024] The purification method of the 1,4-cyclohexanedimethanol composition according to the present invention includes: step 1: introducing a CHDM crude composition containing 1,4-cyclohexanedimethanol (CHDM), water and by-products into an FFE (falling film evaporator), evaporating a first stream containing water as a main component at the upper part of the FFE, and separating a second stream containing CHDM as a main component at the lower part of the FFE; step 2: conveying the first stream to an absorber and recovering CHDM at the lower part of the absorber; and step 3: compressing the stream discharged to the upper part of the absorber in step 2 using an MVR (mechanical vapor compressor) and using it as a heat source for the FFE.

[0025] Hereinafter, each step of the method for purifying a 1,4-cyclohexanedimethanol composition according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0026] Figure 1 Schematic diagram showing a method for purifying a 1,4-cyclohexanedimethanol composition according to an embodiment of the present invention.

[0027] First, step 1 is performed to introduce a crude CHDM composition containing 1,4-cyclohexanedimethanol (CHDM), water and by-products into an FFE (falling film evaporator), evaporate a first stream containing water as a main component at the upper part of the FFE, and separate a second stream containing CHDM as a main component at the lower part of the FFE.

[0028] The crude 1,4-cyclohexanedimethanol composition to be purified by the purification method of the present invention is obtained by a two-step hydrogenation reaction of terephthalic acid, but is not limited thereto. The terephthalic acid as the first reactant undergoes a hydrogenation reaction while being dissolved in water, but has a low solubility in water. Therefore, the crude 1,4-cyclohexanedimethanol composition contains a large amount of water.

[0029] For example, based on the total weight, the crude 1,4-cyclohexanedimethanol composition contains 10 to 40 wt% CHDM, 60 to 90 wt% water, and a small amount of by-products. In addition to 10 to 40 wt% CHDM, a considerable portion of the remaining components is water.

[0030] In addition, since water is a solvent with a large specific heat capacity, removing water by conventional separation processes is very energy inefficient. In addition, CHDM has hydroxyl groups and is therefore highly hydrophilic to water. Therefore, when the solvent is removed from the crude CHDM product and CHDM is recovered, the CHDM concentration associated with water is likely to increase. If the CHDM concentration associated with water increases, CHDM losses will occur, which greatly reduces the economic feasibility of the process and also has a negative impact on the environment. Therefore, in order to recover purified CHDM, it is necessary to remove water with low energy and reduce the CHDM concentration associated with water as much as possible.

[0031] Therefore, in one embodiment of the present invention, first, a step of removing water from the CHDM crude composition using a FFE (falling film evaporator) is performed.

[0032] Falling film evaporator (FFE) is an evaporator that evaporates the target material by flowing it down as a thin film on the upper part of a heated tube. The advantages of FFE are that it can achieve a continuous evaporation process and evaporate the solvent through a thin film with a large surface area and a small thickness, thereby removing the solvent more efficiently than a conventional evaporator.

[0033] See also Figure 1 , step 1 is performed: a crude 1,4-cyclohexanedimethanol composition 1 as a purification target of the present invention is introduced into FFE 10, a first stream 3 containing water as a main component is evaporated at the upper part of FFE 10, and a second stream 2 containing CHDM as a main component is separated at the lower part of FFE.

[0034] In the present disclosure, "containing as a main component" means that the content of the component is 60% by weight or more of the total weight of the stream.

[0035] In this disclosure, "barg" refers to bar gauge pressure, which is the pressure obtained by subtracting the atmospheric pressure from the actual pressure at the measurement location.

[0036] As an example, the operation of FFE 10 in step 1 can be carried out at a temperature of 100 to 130° C. and a pressure of 0.1 to 4 barg. More preferably, the operation can be carried out at a temperature of 115 to 125° C. and a pressure of 0.5 to 3 barg, or at a temperature of 118 to 123° C. and a pressure of 0.5 to 2 barg. In the case of deviation from the above temperature and pressure conditions, water cannot be sufficiently removed from the upper part of FFE 10, so it is necessary to further remove water in the later stage process, which increases the energy consumption required for purification.

[0037] Through the above step 1, more than 90 wt %, preferably more than 92 wt %, and more preferably more than 95 wt % of the total weight of the water contained in the initial CHDM crude composition 1 can be evaporated at the upper part of the FFE 10 and separated into the first stream 3. The upper limit of the water contained in the first stream 3 is preferably higher, but in view of energy efficiency, it can be about 99 wt % or less, or about 98 wt % or less.

[0038] In the lower part of FFE 10, most of the water is removed from the 1,4-cyclohexanedimethanol crude composition 1, and a second stream 2 containing CHDM as a main component is separated before the 1,4-cyclohexanedimethanol crude composition 1 is introduced into FFE 10. According to an embodiment of the present disclosure, the second stream 2 may contain 95 wt% or more, preferably 96 wt% or more, and more preferably 98 wt% or more of CHDM based on the total weight of CHDM contained in the initial CHDM crude composition 1. It is preferred that the upper limit of CHDM contained in the second stream 2 is higher, but from the perspective of energy efficiency, it may be about 99.9 wt% or less, or about 99.5 wt% or less.

[0039] Next, step 2 is performed to transfer the first stream 3 separated at the upper part of the FFE 10 to the absorber 20 and recover CHDM at the lower part of the absorber.

[0040] In step 1, since most of the water is separated from the CHDM crude composition into the first stream 3 using FFE 10, most of the water contained in the initial CHDM crude composition 1 is separated into the first stream 3, and the second stream 2 of purified CHDM can be separated in the lower part, but the first stream 3 separated in the upper part still contains about 1 weight % of CHDM based on the total weight of CHDM contained in the initial CHDM crude composition 1.

[0041] In step 2 , the excess CHDM contained in the first stream 3 is recovered in the absorber 20 .

[0042] That is, step 2 is a step of distilling the first stream 3 subjected to the separation in step 1 using the FFE 10 in the absorber 20 to separate by-products and water in the upper portion, and to separate and recover CHDM in the lower portion.

[0043] At this time, cooling water of 20 to 50° C., preferably 25 to 35° C., may be introduced into the absorber 20 of step 2, and the amount of CHDM recovered may increase according to the amount of cooling water introduced. Meanwhile, the recovered CHDM stream 4 is combined with the second stream 2 separated at the lower part of the FFE 10 in step 1 and included in the CHDM concentrated stream 7, so the more cooling water is used, the more energy is required for treatment in the later stage process, which reduces economic efficiency, so an appropriate amount must be used.

[0044] Therefore, according to one embodiment of the present invention, when the amount of CHDM contained in the first stream 3 introduced into the absorber 20 is about 15 to 25 kg / h, about 100 to 200 kg / hr, preferably about 120 to 180 kg / hr of cooling water is introduced into the absorber 20, which is preferred in terms of CHDM recovery rate and economic efficiency.

[0045] According to one embodiment of the present invention, in step 2, 50 wt% or more, preferably 55 wt% or more, and more preferably 60 wt% or more of CHDM based on the total weight of CHDM contained in the first stream 3 introduced into the absorber 20 can be recovered into the CHDM stream 4. The upper limit of CHDM recovered as the CHDM stream 4 is preferably higher, but may be about 90 wt% or less, or about 80 wt% or less in view of energy efficiency.

[0046] The recovered CHDM stream 4 is combined with the second stream 2 separated in the lower part of FFE 10 in step 1 and sent to the CHDM concentrated stream 7, and then undergoes a subsequent process such as distillation to obtain CHDM with a purity of more than 99.8%.

[0047] Next, step 3 is performed, that is, the third stream 5 discharged to the upper part of the absorber 20 in step 2 is compressed using an MVR (mechanical vapor compressor) and used as a heat source 6 for FFE.

[0048] The third stream 5 discharged to the upper portion of the absorber 20 is mainly composed of gaseous water (about 99% by weight or more) and contains a small amount of CHDM and by-products.

[0049] If it is compressed using MVR 30 and then circulated to FFE 10 and used as heat source 6 of FFE 10, the amount of steam consumed in FFE 10 can be reduced, so that the energy used can be greatly reduced.

[0050] The CHDM composition obtained by the purification method of the present disclosure as described above may have a CHDM purity of 99.5 wt % or more, which is calculated from the CHDM content measured by gas chromatography (GC) analysis.

[0051] More specifically, in the purified CHDM composition, the CHDM content, ie, purity, may be 99.5 wt % or more, or 99.7 wt % or more, or 99.75 wt % or more, or 99.8 wt % or more.

[0052] In addition, the residual water content in the purified CHDM composition is 0.15 wt % or less, or 0.13 wt % or less, or 0.12 wt % or less, or 0.10 wt % or less, or 0.09 wt % or less, or 0.08 wt % or less, or 0.07 wt % or less, based on the total weight of the purified CHDM composition, and the water content can be very low.

[0053] As described above, CHDM obtained by the purification method of the present disclosure has high purity and contains very low residual water and by-products, and thus can be usefully used as a raw material for producing high-quality products such as medicines, synthetic resins, synthetic fibers, or dyes.

[0054] The crude 1,4-cyclohexanedimethanol composition as the target of the purification method of the present disclosure described above can be produced by performing the following reactions: a first step hydrogenation reaction of converting terephthalic acid as a starting material into 1,4-cyclohexanedicarboxylic acid (CHDA), and a second step hydrogenation reaction of converting 1,4-cyclohexanedicarboxylic acid into 1,4-cyclohexanedimethanol.

[0055] As an example, it can be produced by a production method comprising the following steps: step 1, introducing a reaction solution containing terephthalic acid, a first hydrogenation catalyst and water, and hydrogen into a first reactor equipped with a stirrer, and performing a hydrogenation reaction to generate 1,4-cyclohexanedicarboxylic acid (CHDA) containing cis-isomers and trans-isomers; step 2: introducing the reaction product of step 1, a reaction solution containing a second hydrogenation catalyst and water, and hydrogen into a second reactor equipped with a stirrer, and performing a hydrogenation reaction to generate 1,4-cyclohexanedimethanol (CHDM) containing cis-isomers and trans-isomers, but the present invention is not limited thereto.

[0056] The crude composition of the reaction product 1,4-cyclohexanedimethanol obtained after the reaction in step 2 includes 1,4-cyclohexanedimethanol containing cis- and trans-isomers, water as a solvent, and reaction by-products, etc., which can be purified by the purification method of the present invention to obtain high-purity 1,4-cyclohexanedimethanol.

[0057] In order to better understand the present invention, the present invention will be described in more detail below by examples. However, these examples are only for illustrative purposes, and the present invention is not limited thereto.

[0058] <Example>

[0059] Production Example 1

[0060] Step 1

[0061] A first reactor equipped with a gas introduction type stirrer was prepared.

[0062] Into the reactor, 3,200 g of terephthalic acid (TPA, 5 wt%), 16,000 kg of distilled water as a solvent, and a hydrogenation catalyst Pd / C (containing 5 wt% Pd, based on carrier carbon) accounting for 15 mass% of the total solution containing the reactants and the solvent were introduced as reactants, the internal atmosphere of the reactor was replaced with nitrogen, and then the temperature of the mixed solution was raised to 170°C while stirring at a low speed.

[0063] After the temperature of the mixed solution reached 170°C, the solution was stirred for 30 minutes while maintaining the temperature to dissolve TPA. Then, the stirring speed was increased and hydrogen was introduced into the reaction solution to maintain the internal pressure of the reactor at 100 barg and the surface area per unit volume of hydrogen at 300 to 500 m 2 / m 3 , and the hydrogenation reaction was carried out for 3 hours.

[0064] After the reaction was completed, a product containing 3,144 g of 1,4-cyclohexanedimethanol (CHDA) (ratio of trans-CHDA in CHDA: 68 wt %) and 16,031 g of water was obtained, which was used as a reactant for the hydrogenation reaction in step 2 after only the hydrogenation catalyst was removed with a metal filter.

[0065] Step 2

[0066] A second reactor equipped with a gas introduction type stirrer was prepared.

[0067] Into the second reactor, the reaction product of step 1, i.e., 3,144 g of CHDA (ratio of trans-CHDA in CHDA: 68 wt%), 16,031 g of distilled water solvent, and a catalyst (ruthenium-tin / carbon catalyst containing 5 parts by weight of ruthenium and 5.8 parts by weight of tin based on 100 parts by weight of the carbon carrier) accounting for about 57 wt% of the total solution containing the reactants and the solvent were introduced, and the mixture was purged twice with 5 bar of nitrogen and twice with 5 bar of hydrogen, and then the temperature was raised to 230° C. while stirring at a low speed under a hydrogen atmosphere (about 14-15 bar).

[0068] After reaching the reaction temperature, hydrogen was introduced to make the reaction pressure reach 100 barg, and then the stirring speed was increased. The surface area per unit volume of hydrogen bubbles was maintained at 300 to 450 m 2 / m 3 The reaction was carried out for 6 hours.

[0069] The hydrogenation catalyst in the reaction product of step 2 is removed using a metal filter, and the product is then transferred to the purification step of Example.

[0070] Comparative Example 1

[0071] according to Figure 2 Schematic diagram shown, 1,4-cyclohexanedimethanol composition is purified.

[0072] First, the CHDM crude composition 1a of Manufacturing Example 1 is introduced into FFE 10. Water is removed in the upper stream 3a of FFE 10, and CHDM is separated in the lower stream 2a. When FFE 10 is operated so that about 10% of water is present in the lower stream 2a, the required heat capacity is about 5 Gcal / hr, and LPS (low pressure steam) is used as a heat source. At this time, about 20 kg / hr of CHDM is accompanied in the upper stream 3a of FFE 10. The upper stream 3a is then treated as wastewater, and the organic matter content in the upper stream 3a is 5717 ppm.

[0073] The temperature, pressure and composition of each stream are shown in Table 1 below.

[0074] [Table 1]

[0075] flow 1a 2a 3a Temperature(℃) 121 120.4 103 Pressure(barg) 1 1 0.1 Water (kg / hr) 10088.7 350.4 9738.3 CHDM(kg / hr) 2556.0 2535.8 20.2 By-products (kg / hr) 140.0 104.2 35.8

[0076] Comparative Example 2

[0077] according to Figure 3 Schematic diagram shown, 1,4-cyclohexanedimethanol composition is purified.

[0078] First, the CHDM crude composition 1b of Production Example 1 is introduced into FFE 10. Water is removed in the upper stream 3b of FFE 10, and CHDM is separated in the lower stream 2b. When FFE 10 is operated so that about 10% of water exists in the lower stream 2b, the required heat capacity is about 5 Gcal / hr, and LPS (low pressure steam) is used as the initial heat source. At this time, about 20 kg / hr of CHDM is also accompanied in the upper stream 3b.

[0079] The upper stream 3b is sent to MVR 30 and is used again as the heat source 4b of FFE 10 by gas phase compression. The heat capacity available using MVR 30 is about 5.3 Gcal / hr, and it can be operated without inputting additional heat capacity. The required electricity at this time is about 730 kW, which is equivalent to 0.63 Gcal / hr, so even considering the electricity usage, the introduction of MVR 30 greatly reduces the energy usage compared with Comparative Example 1. However, since there is still a considerable amount of unrecovered CHDM (35.8 kg / hr) in the upper stream 3b, there is no advantage in the recovery rate of CHDM.

[0080] The temperature, pressure and composition of each stream are shown in Table 2 below.

[0081] [Table 2]

[0082] flow 1b 2b 3b 4b 5b Temperature(℃) 121 120.4 103 156 110.5 Pressure(barg) 1 1 0.1 2.4 2.4 Water (kg / hr) 10088.7 350.4 9738.3 9738.3 9738.3 CHDM(kg / hr) 2556.0 2535.8 20.2 20.2 20.2 By-products (kg / hr) 140.0 104.2 35.8 35.8 35.8

[0083] Example 1

[0084] according to Figure 1 Schematic diagram shown, 1,4-cyclohexanedimethanol composition is purified.

[0085] The CHDM crude composition 1 of Production Example 1 is introduced into FFE 10. In the upper part of FFE 10, water is removed in the first stream 3, and CHDM is separated in the lower part in the second stream 2. When FFE 10 is operated so that about 10% of water exists in the second stream 2, the required heat capacity is about 5 Gcal / hr, and LPS (low pressure steam) is used as the initial heat source. At this time, even in the first stream 3, about 20 kg / hr of CHDM is accompanied.

[0086] Next, the first stream 3 separated at the upper portion of the FFE 10 was transferred to the absorber 20. Cooling water of 30° C. was introduced into the absorber 20 at about 150 kg / hr.

[0087] The third stream 5 discharged to the upper part of the absorber 20 is compressed by the MVR 30 and used again as a heat source 6 for FFE, and is recovered into the CHDM stream 4 at the lower part.

[0088] Although the upper stream 3b of Comparative Example 2 contained about 20 kg / hr of CHDM, it was confirmed that in the case of the third stream 5 supplied to the MVR 30, about 12 kg / hr of CHDM, including about 8 kg / hr of CHDM, was recovered in the lower CHDM stream 4.

[0089] The heat capacity that can be obtained using MVR 30 is about 5.3Gcal / hr, and it can be operated without inputting additional heat capacity. The power required at this time is about 730kW, which is equivalent to 0.63Gcal / hr, so even considering the power consumption, the introduction of MVR 30 can significantly reduce energy usage compared to Comparative Example 1.

[0090] In addition, the organic matter content in the treated stream is 4454 ppm, which is lower than the organic matter content of 5717 ppm in Comparative Example 1.

[0091] The temperature, pressure and composition of each stream are shown in Table 3 below.

[0092] [Table 3]

[0093] flow 1 2 3 4 5 6 7 8 Temperature(℃) 121 120.4 103 103 103 156 101 110.5 Pressure(barg) 1 1 0.1 0.1 0.1 2.4 0.1 2.4 Water (kg / hr) 10088.7 350.4 9738.3 166.4 9721.9 9721.9 516.8 9721.9 CHDM(kg / hr) 2556.0 2535.8 20.2 12.3 7.9 7.9 2548.1 7.9 By-products (kg / hr) 140.0 104.2 35.8 0.2 35.6 35.6 104.4 35.6

[0094] According to the purification method of the embodiment of the present disclosure, it is confirmed that by using FFE, absorption tower and MVR, water can be removed efficiently with low energy, high-purity CHDM can be separated, and the organic content in wastewater can be reduced.

[0095] [Explanation of Reference Numerals]

[0096] 1: 1,4-cyclohexanedimethanol crude composition

[0097] 2: Second Stream

[0098] 3: First-class

[0099] 4: CHDM flow

[0100] 5: Third Stream

[0101] 6: Heat source

[0102] 7: CHDM Concentrate Flow

[0103] 10: FFE (falling film evaporator)

[0104] 20: Absorber

[0105] 30: MVR (Mechanical Steam Compressor)

Claims

1. A method for purifying a 1,4-cyclohexanedimethanol composition, comprising: Step 1: A CHDM crude composition containing 1,4-cyclohexanedimethanol (CHDM), water and by-products is introduced into an FFE (falling film evaporator), a first stream containing water as a main component is evaporated at the upper part of the FFE, and a second stream containing CHDM as a main component is separated at the lower part of the FFE; Step 2: conveying the first stream to an absorber and recovering CHDM in the lower part of the absorber; and Step 3: The stream discharged to the upper part of the absorber in step 2 is compressed using an MVR (Mechanical Vapor Compressor) and used as a heat source for the FFE.

2. The method for purifying a 1,4-cyclohexanedimethanol composition according to claim 1, wherein: The FFE operation is carried out at a temperature of 100 to 130°C and a pressure of 0.1 to 4 barg.

3. The method for purifying a 1,4-cyclohexanedimethanol composition according to claim 1, wherein: The CHDM crude composition contains 10 to 40 wt% CHDM, 60 to 90 wt% water, and by-products based on the total weight.

4. The method for purifying a 1,4-cyclohexanedimethanol composition according to claim 1, wherein: Through step 1, more than 90 wt% of water based on the total weight of water contained in the initial CHDM crude composition is separated into the first stream.

5. The method for purifying a 1,4-cyclohexanedimethanol composition according to claim 1, wherein: Through step 1, more than 95 wt% of CHDM based on the total weight of CHDM contained in the initial CHDM crude composition is separated into the second stream.

6. The method for purifying a 1,4-cyclohexanedimethanol composition according to claim 1, wherein: Cooling water at 20 to 50° C. is introduced into the absorber.

7. The method for purifying a 1,4-cyclohexanedimethanol composition according to claim 6, wherein: When the amount of CHDM contained in the first stream introduced into the absorber is 15 to 25 kg / hr, 100 to 200 kg / hr of cooling water is introduced into the absorber.

8. The method for purifying a 1,4-cyclohexanedimethanol composition according to claim 1, wherein: Through step 2, more than 50 wt% of CHDM based on the total weight of CHDM contained in the first stream introduced into the absorber is recovered into the CHDM stream.

9. The method for purifying a 1,4-cyclohexanedimethanol composition according to claim 8, wherein: The recovered CHDM stream is combined with the second stream separated from the lower portion of the FFE in step 1 and sent to the CHDM concentrate stream.

10. The method for purifying a 1,4-cyclohexanedimethanol composition according to claim 1, wherein: The CHDM crude composition is produced by performing the following reactions: The first step is the hydrogenation reaction of terephthalic acid as the starting material into 1,4-cyclohexanedicarboxylic acid (CHDA), and the second step is the hydrogenation reaction of 1,4-cyclohexanedicarboxylic acid into 1,4-cyclohexanedimethanol.

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