Method for producing 1,3-butanediol and 1,3-butanediol product

Abstract

The present invention provides a method for producing high-purity 1,3-butanediol with a very small content of low-boiling-point components and a high initial boiling point at a high recovery rate. The crude reaction liquid containing 1,3-butanediol is subjected to a dehydration process for removing water by distillation and a de-high boiling process for removing high-boiling-point components by distillation, and is provided to a product distillation process for obtaining purified 1,3-butanediol. A method for producing 1,3-butanediol, wherein, in a product tower used in the product distillation process, a charge liquid having a water content of 1.2% by weight or less is distilled under a reflux ratio exceeding 0.1, a liquid in which the low-boiling-point components are concentrated is distilled from the top of the charge layer, and 1,3-butanediol is extracted from the bottom of the charge layer.

Description

Technical Field

[0001] The present disclosure relates to a method for producing 1,3-butanediol and a 1,3-butanediol product. This application claims priority to Japanese Patent Application Nos. 2019-239974, 2019-239975, 2019-239976, 2019-239977, 2019-239978, 2019-239979 filed in Japan on December 28, 2019, 2020-006660 filed in Japan on January 20, 2020, and 2020-018910 filed in Japan on February 6, 2020, and the contents thereof are incorporated herein by reference. Background Art

[0002] 1,3-Butanediol is a colorless, transparent, odorless liquid with low volatility, low toxicity, high hygroscopicity, and excellent chemical stability. Therefore, the uses of 1,3-Butanediol include raw materials for various synthetic resins and surfactants, as well as cosmetics, hygroscopic agents, high-boiling point solvents, and raw materials for antifreeze. In recent years, 1,3-Butanediol has attracted much attention for its excellent properties as a moisturizer, which has expanded its demand in the cosmetics industry.

[0003] The crude reaction liquid during the manufacture of 1,3-butanediol contains a large amount of low-boiling impurities such as ethanol, butanol, acetaldehyde, crotonaldehyde, and esters. When acetaldehyde, crotonaldehyde, etc. are dimerized and polymerized to a level higher than that, high-boiling impurities are generated. In addition, in the purification process of 1,3-butanediol, low-boiling impurities and high-boiling impurities are also generated due to heat and the like. In the product of 1,3-butanediol, the less such impurities, the better. Japanese Patent Publication No. 6-329664 discloses a method for controlling impurities derived from crotonaldehyde, which is a low-boiling impurity. Japanese Patent Publication No. 2001-213828 discloses that when the crude reaction liquid of 1,3-butanediol synthesized by hydrogenation of butanol aldehydes is made alkaline, the alcohol is removed by distillation, and then distillation is performed, a product of 1,3-butanediol with high purity can be manufactured with good yield and economic advantage. Furthermore, this document describes that ethanol, isopropanol, and butanol, which are low-boiling point impurities, are removed by distillation.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 6-329664

[0007] Patent Document 2: Japanese Patent Application Publication No. 2001-213828 Summary of the invention

[0008] Problem that the invention aims to solve

[0009] However, conventional methods have not been sufficient to remove low-boiling and high-boiling components from 1,3-butylene glycol. Cosmetics, which are important uses of 1,3-butylene glycol, usually contain water, and it takes a long time from production to actual use by ordinary consumers. In addition, cosmetics have to be strictly adjusted in terms of storage stability and other aspects.

[0010] When 1,3-butylene glycol containing low-boiling point components and high-boiling point components is used in cosmetics, the liquid balance of the cosmetics may be lost due to the increase in acid concentration, and the intended effect may be lost. In addition, the increase in the acid concentration of the cosmetics may also cause the user's skin to become rough.

[0011] Furthermore, when using cosmetics or storing them after use, the cosmetics are exposed to air. In addition, when manufacturing cosmetics, the work is usually carried out in an air atmosphere, and heating is sometimes performed for the purpose of sterilization. When 1,3-butylene glycol containing low-boiling point components and high-boiling point components is used in cosmetics, coloring may occur due to the presence of air or the influence of heating.

[0012] In order to solve such a problem, it is required to remove by-products from crude 1,3-butanediol and purify 1,3-butanediol.

[0013] On the other hand, one of the quality criteria of 1,3-butanediol is the initial boiling point. It can be said that the higher the initial boiling point, the better the quality. However, in the past, there has been almost no technical research aimed at improving the initial boiling point.

[0014] Therefore, an object of the present disclosure is to provide a method for producing high-purity 1,3-butanediol having a very small content of low-boiling-point components and a high initial boiling point at a high recovery rate.

[0015] Another object of the present disclosure is to provide a high-purity 1,3-butanediol product having a very small content of low-boiling-point components and a high initial boiling point.

[0016] Another object of the present disclosure is to provide a moisturizing agent and a cosmetic material that have excellent moisturizing performance and can maintain high quality for a long time.

[0017] Technical Solution

[0018] The inventors of the present disclosure have conducted intensive research to achieve the above-mentioned purpose, and found that if the water content in the feed liquid to the product tower is specified and the reflux ratio of the product tower is controlled, or the product tower distillate is recycled to the dehydration tower and the low-boiling-point removal tower, the low-boiling components mixed in the product tower feed liquid can be removed efficiently, the initial boiling point of 1,3-butanediol can be maintained within the standard value, and the recovery rate of 1,3-butanediol can be maintained and improved. The present disclosure was completed based on these findings.

[0019] That is, the present disclosure provides a method for producing 1,3-butanediol, which is a method for producing 1,3-butanediol by obtaining purified 1,3-butanediol from a crude reaction liquid containing 1,3-butanediol, wherein:

[0020] The production method comprises a dehydration step of removing water by distillation, a high boiling point removal step of removing high boiling point components by distillation, and a product distillation step for obtaining purified 1,3-butanediol.

[0021] In the product column used in the product distillation step, a charge liquid containing 1,3-butanediol is distilled at a reflux ratio exceeding 0.1, a liquid concentrated in low boiling point components is distilled from above the charge layer, and 1,3-butanediol is extracted from below the charge layer.

[0022] The crude reaction liquid containing 1,3-butanediol may be a crude reaction liquid obtained by hydrogen reduction of butanol aldehydes.

[0023] The production method may further include an alkali treatment step of treating the process stream containing 1,3-butanediol with an alkali.

[0024] The manufacturing method may further include a desalting step of removing salt from a process stream containing the 1,3-butanediol.

[0025] The production method may further include a dealcoholization step of removing low-boiling substances including alcohol from a process stream including the 1,3-butanediol.

[0026] The reflux ratio of the product column may be set to 0.2 or more.

[0027] The concentration of 1,3-butanediol in the feed liquid to the product column may be 90% or more.

[0028] The water content in the feed liquid to the product column may be 3% by weight or less.

[0029] The content of low-boiling-point components other than water in the feed liquid to the product column may be 1.8% or less.

[0030] The distillation rate in the product column may be set to less than 30% by weight.

[0031] The theoretical number of layers of the product tower is, for example, 1 to 100 layers.

[0032] At least a portion of the distillate from the product column may be recycled to a dehydration step, a dealcoholization step, a low boiling point removal step, or a step before these steps, which are steps before the product distillation step.

[0033] The amount of the distillate from the product column recycled to a step before the product distillation step may be within a range not exceeding the amount distilled from the product column and less than 30% by weight relative to the amount charged to the product column.

[0034] The amount of the distillate from the product column recycled to a step before the product distillation step may be within a range not greater than the amount distilled from the product column and may be 0.01 wt % or more relative to the amount charged to the product column.

[0035] The present disclosure also provides a 1,3-butanediol product having an initial boiling point higher than 203° C. and a water content of less than 0.4 wt %.

[0036] In the 1,3-butanediol product, in a gas chromatography analysis under the following conditions, the area ratio of the 1,3-butanediol peak may be higher than 98.5%, and the total area ratio of peaks having a shorter retention time than the 1,3-butanediol peak may be lower than 0.3%.

[0037] (Conditions for gas chromatography analysis)

[0038] Analytical column: a column with dimethylpolysiloxane as the stationary phase (film thickness 1.0 μm×length 30 m×inner diameter 0.25 mm).

[0039] Heating conditions: After heating from 80°C to 120°C at 5°C / min, heating to 160°C at 2°C / min and maintaining for 2 minutes, heating to 230°C at 10°C / min and maintaining at 230°C for 18 minutes.

[0040] Sample introduction temperature: 250°C.

[0041] Carrier gas: Helium.

[0042] Column gas flow rate: 1 mL / min.

[0043] Detector and detection temperature: hydrogen flame ionization detector (FID), 280°C.

[0044] In addition, the present disclosure provides a moisturizer comprising the 1,3-butanediol preparation.

[0045] In addition, the present disclosure also provides a cosmetic comprising the moisturizing agent.

[0046] In the present disclosure, the term "1,3-butanediol product" refers to a composition in which 1,3-butanediol accounts for most of the constituent components (for example, the 1,3-butanediol content is 95% by weight or more, preferably 98% by weight or more).

[0047] Effects of the Invention

[0048] According to the production method disclosed herein, high-purity 1,3-butanediol having a very low content of low-boiling-point components and a high initial boiling point can be produced at a high recovery rate.

[0049] Furthermore, the 1,3-butanediol product of the present disclosure has a very low content of low-boiling-point components, a high initial boiling point, and high purity, and is therefore suitable for use as a moisturizer or as a raw material for cosmetics.

[0050] Furthermore, the moisturizing agent and cosmetic of the present disclosure are excellent in moisturizing performance and contain an extremely small amount of low-boiling-point components, and thus can maintain high quality for a long period of time. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a flow chart of a method for producing a 1,3-butanediol product (purification method) according to the present disclosure.

[0052] Figure 2 This is a spectrum of the 1,3-butanediol product in Example 12 analyzed by gas chromatography.

[0053] Figure 3 This is a spectrum of the 1,3-butanediol product in Comparative Example 2 obtained by gas chromatography analysis. DETAILED DESCRIPTION

[0054] [Method for producing 1,3-butanediol]

[0055] The method for producing 1,3-butanediol disclosed in the present invention is a method for producing 1,3-butanediol in which purified 1,3-butanediol is obtained from a crude reaction liquid containing 1,3-butanediol (1,3BG) (hereinafter, sometimes referred to as "crude 1,3-butanediol"), and the method comprises a dehydration step of removing water by distillation, a high boiling point removal step of removing high boiling point components by distillation, and a product distillation step for obtaining purified 1,3-butanediol. In the product column used in the product distillation step, a charge liquid containing 1,3-butanediol is distilled under a reflux ratio exceeding 0.1, a liquid in which low boiling point components are concentrated is distilled from the upper portion of the charge layer, and 1,3-butanediol is extracted from the lower portion of the charge layer. The content of low boiling point components in the 1,3-butanediol is very small and the initial boiling point is high, so that a 1,3-butanediol product can be obtained.

[0056] [Crude 1,3-butanediol]

[0057] Examples of crude 1,3-butanediol include: (1) a crude reaction liquid obtained by reduction (hydrogenation) of butanol aldehydes; (2) a crude reaction liquid obtained by hydrolysis of 1,3-butylene oxide; (3) a crude reaction liquid obtained by selective hydrogenation and decomposition of erythritol; (4) a crude reaction liquid obtained by selective addition of water to butadiene; (5) a crude reaction liquid obtained by hydrogenation of n-butyraldehyde-3-one; (6) a crude reaction liquid obtained by hydrogenation of 1-butanol-3-one; (7) a crude reaction liquid obtained by hydrogenation of 3-hydroxy-1-butyric acid; (8) a crude reaction liquid obtained by hydrogenation of β-butyrolactone; and (9) a crude reaction liquid obtained by hydrogenation of diketene. In the present disclosure, the crude 1,3-butanediol may be one of the above (1) to (9) or a mixture of two or more thereof. The crude 1,3-butanediol is preferably a crude reaction liquid obtained by reduction (particularly liquid phase reduction) of butanol aldehydes in the above (1).

[0058] Hereinafter, the case where a crude reaction liquid obtained by reduction (hydrogenation) of butanol aldehydes is used as crude 1,3-butanediol will be mainly described. In addition, the step of reducing (hydrogenating) butanol aldehydes may be referred to as a "hydrogenation step".

[0059] The butanol aldehydes used as raw materials in the hydrogenation step are not particularly limited as long as they are compounds that are reduced to 1,3-butanediol by hydrogen. Examples of the raw butanol aldehydes include butanol aldehyde, dimer m-hydroxybutyraldehyde as a cyclic dimer thereof, 2,6-dimethyl-1,3-dioxane-4-ol as a cyclic trimer of acetaldehyde, and mixtures thereof.

[0060] The method for producing butanol aldehydes (e.g., butanol aldehyde and dimer meta-hydroxybutyraldehyde) is not particularly limited, and for example, it can be obtained by an aldol condensation reaction of acetaldehyde in the presence of a basic catalyst, or by thermal decomposition of 2,6-dimethyl-1,3-dioxane-4-ol, etc. It should be noted that the process of producing butanol aldehydes is sometimes referred to as a "butanol aldehyde production process" or an "acetaldehyde polymerization process."

[0061] The crude reaction liquid containing butanol aldehydes obtained by the above-mentioned reaction can be neutralized with acid to produce 1,3-butanediol. In such a crude reaction liquid, in addition to butanol aldehydes, acetaldehyde, crotonaldehyde, other aldehyde components, low boiling point substances, high boiling point substances such as aldehyde dimers or trimers, water, salts, etc. may also be included. It should be noted that in this specification, compounds with a boiling point lower than 1,3-butanediol are sometimes referred to as "low boiling point substances" or "low boiling substances", and compounds with a boiling point higher than 1,3-butanediol are referred to as "high boiling point substances" or "high boiling substances".

[0062] The above-mentioned reaction crude liquid containing butanol aldehydes can use pre-treatments such as dealcoholization distillation, dehydration distillation, desalination, alkali treatment and dealkalization treatment, decontamination as needed to remove the material of by-products such as unreacted acetaldehyde and crotonaldehyde. As the method of pre-treatment, distillation, adsorption, ion exchange, heating high boiling point materialization, decomposition, etc. can be listed. Distillation can use various distillation methods such as reduced pressure, normal pressure, pressurization, azeotropic, extraction, reaction. Particularly preferably, the reaction crude liquid containing butanol aldehydes is subjected to simple evaporation, distillation, hydrogenation, and after removing aldehydes such as acetaldehyde and crotonaldehyde, a hydrogenation process is implemented.

[0063] The content of butanol aldehydes in the hydrogenation raw material is not particularly limited, and is, for example, 30% by weight or more (e.g., 30 to 99% by weight), more preferably 40% by weight or more (e.g., 40 to 98% by weight), 50% by weight or more (e.g., 50 to 97% by weight), or 60% by weight or more (e.g., 60 to 95% by weight), further preferably 65 to 90% by weight, particularly preferably 70 to 90% by weight, and most preferably 75 to 90% by weight. By making the content of butanol aldehydes within the above range, there is a tendency for the impurities contained in the crude reaction liquid containing 1,3-butanediol (crude 1,3-butanediol) to be reduced.

[0064] The hydrogenation raw material may contain water or not contain water, but from the viewpoint of the purity of the 1,3-butanediol product, it is preferably containing water. The content of water in the hydrogenation raw material is not particularly limited, for example, preferably 2% by weight or more, more preferably 5% by weight or more, further preferably 10% by weight or more, and particularly preferably 15% by weight or more. It should be noted that its upper limit value may be, for example, 90% by weight, 80% by weight, 70% by weight, 60% by weight, 50% by weight, 40% by weight, 30% by weight or 20% by weight. When the content of water is within the above range, the acetal body of 1,3-butanediol and butanol aldehyde contained in the obtained crude 1,3-butanediol is reduced, so there is a tendency that the purity of the 1,3-butanediol product finally obtained becomes higher. The reason is that by including a certain degree of water in the hydrogenation raw material, the above-mentioned acetal body is hydrolyzed to become 1,3-butanediol, and the symbiotic butanol aldehyde is reduced to become 1,3-butanediol.

[0065] As a hydrogenation catalyst, for example, Raney nickel and the like can be cited. The hydrogenation catalyst can be used in a suspended state or filled in a reaction vessel for use. The amount of the hydrogenation catalyst used is not particularly limited, but relative to 100 parts by weight of the hydrogenation raw material, for example, it is preferably 1 to 30 parts by weight, more preferably 4 to 25 parts by weight, further preferably 8 to 20 parts by weight, and particularly preferably 12 to 18 parts by weight. The amount of hydrogen used for the reduction reaction is not particularly limited, but relative to 100 parts by weight of the hydrogenation raw material, for example, it is preferably 0.5 to 40 parts by weight, more preferably 1 to 30 parts by weight, further preferably 4 to 20 parts by weight, and particularly preferably 8 to 12 parts by weight. The pressure (total pressure; gauge pressure) in the reaction system during the reduction reaction is not particularly limited, for example, it is 9 to 70 MPa, preferably 10 to 40 MPa. The hydrogen pressure (hydrogen partial pressure) in the reaction system is not particularly limited, for example, it is 7 to 60 MPa, preferably 10 to 30 MPa. The reaction temperature in the reduction reaction is not particularly limited, and is, for example, 40 to 150° C., preferably 50 to 140° C., and more preferably 60 to 130° C. The reaction time (residence time) in the reduction reaction is not particularly limited, and is, for example, 10 to 500 minutes, preferably 20 to 400 minutes, more preferably 30 to 300 minutes, further preferably 50 to 280 minutes, and particularly preferably 80 to 250 minutes. The reaction can be carried out in any of a batch form, a semi-batch form, or a continuous form.

[0066] The crude 1,3-butanediol thus obtained contains low-boiling substances (low-boiling compounds) having unsaturated bonds such as acetaldehyde (AD), butyraldehyde, crotonaldehyde (CR), acetone, and methyl vinyl ketone, condensates thereof, condensates of 1,3-butanediol and the above-mentioned low-boiling substances (e.g., acetals of 1,3-butanediol and butanolaldehyde, etc.), alcohols such as ethanol, isopropanol, and butanol, water (solvent, etc.), salts generated by neutralization treatment, etc., catalysts (when used in a suspended state), etc. By removing these impurities in the purification step, a 1,3-butanediol product (purified 1,3-butanediol) can be obtained.

[0067] [Purification of crude 1,3-butanediol]

[0068] In the manufacturing method disclosed in the present invention, there is at least a dehydration step for removing water by distillation, a high boiling point removal step (high boiling point removal distillation step) for removing high boiling point components by distillation, and a product distillation step for obtaining purified 1,3-butanediol. The dehydration step and the high boiling point removal step are both arranged before the product distillation step, but the order of the dehydration step and the high boiling point removal step is not limited. In the manufacturing method disclosed in the present invention, in addition to these steps, there may also be a desalination step, an alkali reaction step (alkali treatment step), and a dealkalization step. In addition, a catalyst separation step, a neutralization step using an alkali, and a dealkalization step (low boiling point removal step) may also be arranged before the dehydration step. The various steps can be carried out in the order described, and the order of the various steps may be appropriately changed except that the dealkalization step is arranged after the alkali reaction step. For example, the dealkalization step (low boiling point removal step), the desalination step, the alkali reaction step, and the dealkalization step can be arranged at appropriate locations, usually after the hydrogenation step. It should be noted that among the above steps, the catalyst separation step, the neutralization step using an alkali, the dealcoholization step (low boiling point removal step), the desalination step, the alkali reaction step, and the dealkalization step may be provided as required or may not necessarily be provided.

[0069] Figure 1 This is a flow chart of an apparatus representing an example of an implementation method of the method for producing 1,3-butanediol disclosed in the present invention. A is a dehydration tower, which is related to the dehydration process. B is a desalination tower, which is related to the desalination process. C is a high-boiling-point distillation tower (high-boiling-point removal tower), which is related to the high-boiling-point distillation process (high-boiling-point removal process). D is an alkali reactor, which is related to the alkali reaction process. E is a dealkalization tower, which is related to the dealkalization process. F is a product distillation tower (product tower), which is related to the product distillation process. A-1, B-1, C-1, E-1, and F-1 are condensers. A-2, C-2, and F-2 are reboilers. Below, this flow chart is used to illustrate an example of an implementation method of the method for producing 1,3-butanediol disclosed in the present invention.

[0070] The crude 1,3-butanediol (equivalent to "X-1") obtained by hydrogenation of the raw material is supplied to the dehydration tower A. Water is distilled from the top of the tower by distillation in the dehydration tower A, and a crude 1,3-butanediol stream containing 1,3-butanediol is obtained from the bottom of the tower. It should be noted that the crude 1,3-butanediol (equivalent to "X-1") may be supplied to the dehydration tower A after a dealcoholization step (distillation step using a dealcoholization tower) for removing alcohols such as ethanol and low-boiling substances.

[0071] The crude 1,3-butanediol stream is supplied to the demineralization tower B. In the demineralization tower B, the desalted crude 1,3-butanediol stream is obtained from the top of the tower by distillation, and salts, high boiling point substances, etc. are discharged from the bottom of the tower as residual liquid. The residual rate (%) of the demineralization tower B [(desalination tower residual amount (parts) / desalination tower charge amount (parts)) × 100] is, for example, 0.1 to 40% by weight, preferably 1 to 35% by weight, more preferably 2 to 30% by weight, further preferably 3 to 25% by weight, particularly preferably 5 to 20% by weight, and may also be 7 to 15% by weight. It should be noted that at least a portion of the residual liquid of the demineralization tower may be recycled in a process before the desalination process.

[0072] The above-mentioned crude 1,3-butanediol stream after desalting is supplied to the high boiling point removal column C. In the high boiling point removal column C, high boiling point components (high boiling point substances) are discharged from below the charge layer (preferably from the bottom of the column). On the other hand, a crude 1,3-butanediol stream (1,3-butanediol with further improved purity) after high boiling point substances are removed is obtained from above the charge layer.

[0073] As the high-boiling tower C, for example, a porous plate tower, a bubble tower, etc. can be used, but a packed tower with low pressure loss such as Sulzer Packings and Mellapak (both are trade names of Sumitomo Heavy Industries, Ltd.) is more preferably used. The reason is that 1,3-butanediol and the impurities contained in trace amounts are thermally decomposed at high temperatures (for example, above 150°C) to generate low-boiling substances as coloring components, thereby lowering the distillation temperature. In addition, the same influence is also produced when the thermal history (residence time) of 1,3-butanediol is long. Therefore, the reboiler used is preferably one with a shorter residence time of the process side fluid, for example, a thin film evaporator such as a natural falling film evaporator and a forced stirring thin film evaporator is preferred.

[0074] The number of layers of the high boiling removal column C is, as a theoretical number of layers, for example, 1 to 100 layers, preferably 2 to 90 layers, more preferably 3 to 80 layers, further preferably 4 to 70 layers, 5 to 60 layers, 8 to 50 layers or 10 to 40 layers, and particularly preferably 15 to 30 layers. The supply position of the charge liquid is, for example, 10% to 90% of the height of the tower downward from the top of the high boiling removal column, preferably 20% to 80%, more preferably 30 to 70 layers, and further preferably 40% to 60%. In the distillation in the high boiling removal column C, the pressure (absolute pressure) at the top of the tower is, for example, 0.01 to 50 kPa, preferably 0.1 to 30 kPa, more preferably 0.3 to 20 kPa, and further preferably 0.5 to 10 kPa.

[0075] The reflux ratio in the high boiling tower C [the reflux amount of the high boiling tower / the distillate amount of the high boiling tower (the amount discharged to the outside of the distillation tower)] is, for example, 0.015 or more, preferably 0.02 or more, 0.03 or more, 0.05 or more, 0.07 or more, 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, 0.5 or more, 0.6 or more, 0.7 or more, 0.8 or more, 0.9 or more, 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 15 or more, or 20 or more, and more preferably 30 or more. From the viewpoint of energy cost, the upper limit of the reflux ratio is, for example, 100, and preferably 50.

[0076] The crude 1,3-butanediol stream extracted from the upper charging layer of the high-boiling tower C is supplied to an alkali reactor (e.g., a flow-through tubular reactor) D for alkali treatment. The by-products contained in the crude 1,3-butanediol can be decomposed by alkali treatment. The alkali is added to the alkali reactor D or its upstream piping, etc. The amount of alkali added is, for example, 0.05 to 10% by weight, preferably 0.1 to 1.0% by weight, relative to the crude 1,3-butanediol stream subjected to alkali treatment. If the amount of alkali added exceeds 10% by weight, alkali is sometimes precipitated in the distillation tower, piping, etc., causing blockage. In addition, sometimes a decomposition reaction of high-boiling point compounds also occurs, producing by-products instead. When the amount of alkali added is less than 0.05% by weight, the effect of decomposing by-products is small.

[0077] The alkali added to the alkali reactor D or its upstream piping is not particularly limited, and alkali metal compounds are preferred, for example. As alkali metal compounds, for example, sodium hydroxide, potassium hydroxide, sodium carbonate (bicarbonate), potassium carbonate (bicarbonate) can be cited. In addition, as the alkali, a basic ion exchange resin can also be used. As the alkali, sodium hydroxide and potassium hydroxide are preferred from the viewpoint of reducing the by-products contained in the final 1,3-butanediol product. The alkali can be added directly to a solid substance, but for operational purposes and to promote contact with the treated liquid, it is preferably added as an aqueous solution. It should be noted that the above-mentioned alkali can be used alone or in combination of two or more.

[0078] The reaction temperature in the alkaline reactor D is not particularly limited, but is preferably 90°C to 140°C, more preferably 110°C to 130°C, for example. When the reaction temperature is less than 90°C, a long reaction residence time is required, so the reactor capacity becomes large and uneconomical. If the reaction temperature exceeds 140°C, the coloring of the final 1,3-butanediol product increases. The reaction residence time is, for example, preferably 5 minutes to 120 minutes, more preferably 10 to 30 minutes. When the reaction residence time is less than 5 minutes, the reaction becomes insufficient, and sometimes the quality of the final 1,3-butanediol product deteriorates. If the reaction residence time exceeds 120 minutes, a large reactor becomes required and the equipment cost becomes high, so it is disadvantageous from an economic point of view.

[0079] After leaving the alkali reactor D, the crude reaction liquid stream is supplied to the dealkalization tower (such as a thin film evaporator) E as needed, and the alkali and the like are removed from the bottom of the tower by evaporation. On the other hand, a dealkalized crude 1,3-butanediol stream is obtained from the top of the dealkalization tower E. For the purpose of suppressing the thermal process of the process fluid, the evaporator used for the dealkalization tower E is a natural falling film evaporator with a short residence time or a forced stirring type thin film evaporator. It should be noted that an air purifier can also be provided in the space above the loading position of the dealkalization tower (such as a thin film evaporator) E to remove alkali and other droplets. In this way, alkali and high boiling point substances can be prevented from mixing into the 1,3-butanediol product.

[0080] In the evaporator used in the dealkalization column E, evaporation is performed under reduced pressure at an absolute pressure of 20 kPa or less, preferably 0.5 to 10 kPa, at the top of the column. The temperature of the evaporator is preferably 90° C. to 120° C. The crude 1,3-butanediol stream containing low boiling point substances distilled from the top of the column is supplied to a product distillation column (product column) F.

[0081] It should be noted that the alkali reactor D and the dealkalization tower E can be arranged between the desalination tower B and the high boiling tower C, between the dehydration tower A and the desalination tower B (in this case, the desalination tower can also serve as the dealkalization tower), or before the dehydration tower A. In addition, the alkali reactor D and the dealkalization tower E can also be omitted, and the alkali treatment can be carried out by charging the alkali into the high boiling tower charging line, or into the dehydration tower charging line, or into the reaction liquid after hydrogenation [thereafter, charging into the dealcoholization tower (low boiling tower)].

[0082] In the production method of the present disclosure, in the product column F used in the product distillation step, a charge liquid containing 1,3-butanediol is distilled under a reflux ratio of greater than 0.1, and a liquid (equivalent to 1,3-butanediol) in which low-boiling components are concentrated is distilled from the upper portion of the charge layer. Figure 1 "X-6"), 1,3-butanediol (equivalent to Figure 1The 1,3-butanediol has a very small content of low-boiling components and a high initial boiling point, so it can be directly prepared into a 1,3-butanediol product.

[0083] As the product distillation tower F, for example, a porous plate tower, a bubble tower, etc. can be used, but a packed tower with low pressure loss filled with Sulzer Packings, Mellapak (both are trade names of Sumitomo Heavy Industries, Ltd.) or the like is more preferred. The reason is that 1,3-butanediol and impurities contained in trace amounts are thermally decomposed at high temperatures (for example, above 150°C) to generate low-boiling-point substances as coloring components, thereby lowering the distillation temperature. In addition, the same influence also occurs when the thermal history (residence time) of 1,3-butanediol is long. Therefore, the reboiler used is preferably one with a shorter residence time of the process side fluid, for example, a thin film evaporator such as a natural falling film evaporator and a forced stirring type thin film evaporator is preferred.

[0084] The theoretical number of stages of the product column F is, for example, 1 to 100 stages, preferably 2 to 90 stages, 3 to 80 stages, 4 to 70 stages, 5 to 60 stages, 8 to 50 stages or 10 to 40 stages, and more preferably 15 to 30 stages. The feed liquid is supplied from the top of the column downward at, for example, 10% to 90%, preferably 20% to 80%, more preferably 30% to 70%, and more preferably 40% to 60% of the height of the column. In the distillation in the product distillation column F, the pressure (absolute pressure) at the top of the column is, for example, 20 kPa or less, preferably 0.1 to 10 kPa, more preferably 0.3 to 8 kPa, and more preferably 0.5 to 5 kPa.

[0085] exist Figure 1 Regarding the charging to the product tower F, the liquid after condensing the top vapor of the dealkalization tower E will be fed using the condenser E-1, or the top vapor from the dealkalization tower E can be directly fed to the product tower F.

[0086] The concentration of 1,3-butanediol in the liquid charged to the product column F is, for example, 90% or more, preferably 91% or more, more preferably 92% or more, further preferably 93% or more, 94% or more, 95% or more, 96% or more, 97% or more, or 98% or more, and particularly preferably 99% or more. The concentration of 1,3-butanediol in the liquid charged to the product column F can be increased, for example, by adjusting the distillation conditions of the dehydration column A, or by providing a dealcoholization column (low-boiling-removal column) before the dehydration column A and adjusting its distillation conditions, or by adjusting the distillation conditions of the high-boiling-removal column C. For example, by increasing the reflux ratio of the dealcoholization column (low-boiling-removal column), the dehydration column A and / or the high-boiling-removal column C, or by increasing the number of layers, the purity of 1,3-butanediol in the liquid charged to the product column F can be increased. The above-mentioned 1,3-butanediol concentration is the ratio (area %) of the peak area of ​​1,3-butanediol to the total peak area in gas chromatography analysis under the following conditions.

[0087] (Conditions for gas chromatography analysis)

[0088] Analytical column: a column with dimethylpolysiloxane as the stationary phase (film thickness 1.0 μm×length 30 m×inner diameter 0.25 mm).

[0089] Heating conditions: After heating from 80°C to 120°C at 5°C / min, heating to 160°C at 2°C / min and maintaining for 2 minutes, heating to 230°C at 10°C / min and maintaining at 230°C for 18 minutes.

[0090] Sample introduction temperature: 250°C.

[0091] Carrier gas: Helium.

[0092] Column gas flow rate: 1 mL / min.

[0093] Detector and detection temperature: hydrogen flame ionization detector (FID), 280°C.

[0094] In the production method disclosed herein, the content of water in the feed liquid to the product column F is, for example, 3 wt% or less, preferably 2.8 wt% or less, more preferably 2.6 wt% or less, 2.4 wt% or less, 2.2 wt% or less, 2 wt% or less, 1.8 wt% or less, 1.6 wt% or less, 1.4 wt% or less, 1.4 wt% or less, 1.2 wt% or less, 1 wt% or less, 0.95 wt% or less, 0.9 wt% or less, 0.8 wt% or less, 0.7 wt% or less, 0.6 wt% or less, 0.5 wt% or less, 0.4 wt% or less, 0.3 wt% or less, or 0.2 wt% or less, and particularly preferably 0.1 wt% or less. The content of water in the feed liquid to the product column F can be reduced by adjusting the distillation conditions of the dehydration column A. For example, by increasing the reflux ratio, the number of layers, and the distillation rate of the dehydration column A, the concentration of water in the feed liquid to the product column F can be reduced. The water content in the feed liquid to the product column F can be quantitatively determined using a Karl-Fischer moisture meter.

[0095] The content of low boiling point components (excluding water) in the feed liquid to the product tower F is, for example, 1.8% or less, preferably 1.6% or less, 1.4% or less, 1.2% or less, 1.1% or less, 1% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, and more preferably 0.4% or less. The content of low boiling point components (also referred to as "low boiling substances") excluding water in the feed liquid to the product tower F is the ratio (area %) of the total area of ​​the peaks having a shorter retention time than the peak of 1,3-butanediol in the gas chromatography analysis under the above conditions to the total peak area. The content of low boiling point components (excluding water) in the feed liquid to the product tower F can be reduced, for example, by setting a dealcoholization tower (removal of low boiling tower) upstream of the product tower F and adjusting the distillation conditions of the dealcoholization tower (removal of low boiling tower). For example, by increasing the reflux ratio, the number of stages, and the distillation rate of the dealcoholization column (low-boiling removal column), the concentration of low-boiling components (except water) in the feed liquid to the product column F can be reduced.

[0096] In the production method of the present disclosure, the reflux ratio [product column reflux amount / product column distillate amount (amount discharged to the outside of the distillation column)] in the product column F is set to a value greater than 0.1 (for example, 0.15 or more). From the viewpoint of increasing the initial boiling point of the 1,3-butanediol product, the reflux ratio is preferably 0.2 or more, more preferably 0.3 or more, further preferably 0.4 or more, 0.5 or more, 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 20 or more, or 50 or more, and particularly preferably 400 or more (for example, 500 or more).

[0097] In the production method of the present disclosure, by setting the reflux ratio in the product column F to the above-mentioned specific range, high-purity 1,3-butanediol having a very small content of low-boiling-point components and a high initial boiling point can be produced at a high recovery rate.

[0098] In the production method disclosed herein, from the perspective of improving the recovery rate of 1,3-butanediol, the distillation rate of the product column F is, for example, less than 30% by weight, less than 29% by weight, less than 28% by weight, less than 27% by weight, less than 26% by weight, less than 25% by weight, less than 24% by weight, less than 23% by weight, less than 22% by weight, less than 21% by weight, or less than 20% by weight, more preferably 19% by weight or less, 18% by weight or less, 17% by weight or less, 16% by weight or less, or 15% by weight or less, further preferably 12% by weight or less, 10% by weight or less, 8% by weight or less, 5% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, 0.8% by weight or less, or 0.6% by weight or less, and particularly preferably 0.4% by weight or less. It should be noted that the above-mentioned distillation rate refers to the ratio (weight %) of the amount of liquid extracted from the upper side of the charging layer of the product column F (for example, the top of the column) to the outside of the distillation column (when recycled in the previous step described later, the recycled amount is also included) relative to the charging amount to the product column F.

[0099] At least a portion of the liquid (hereinafter sometimes referred to as "distillate") extracted from the upper portion of the charging layer of the product column F in which the low-boiling components are concentrated may be recycled to a step ( Figure 1 By recycling at least a portion of the distillate to a step before the product distillation step, the recovery rate of 1,3-butanediol can be increased.

[0100] Examples of the process before the product distillation process include a dehydration process, a dealcoholization process (low boiling point removal process), etc. The dealcoholization process (low boiling point removal process) is preferably provided before the dehydration process.

[0101] The recycling amount of the distillate to the process before the product distillation process can be appropriately selected within the range of the amount of the distillate. The recycling amount of the distillate to the process before the product distillation process is, for example, less than 30% by weight relative to the amount charged to the product column F. In addition, from the viewpoint of improving the recovery rate of 1,3BG in the product column and the yield of the entire process, the recycling amount of the distillate to the process before the product distillation process is, for example, 0.01% by weight or more, preferably 0.05% by weight or more, more preferably 0.1% by weight or more, 0.5% by weight or more, 1% by weight or more, 1.5% by weight or more, 2% by weight or more, 3% by weight or more, 4% by weight or more, 5% by weight or more, 7% by weight or more, or 10% by weight or more, and particularly preferably 20% by weight or more.

[0102] Thus, according to the production method disclosed herein, high-purity 1,3-butanediol having a very low content of low boiling point components and a high initial boiling point can be produced at a high recovery rate. In this specification, the recovery rate of 1,3BG in the product column F is a value (%) calculated by the following formula.

[0103] {1-[GC area % of 1,3BG in distillate × (distillate amount (portions) - recycled amount (portions))] / (GC area % of 1,3BG in charge liquid × charge amount (portions))}×100 It should be noted that low-boiling and high-boiling substances are sometimes hydrolyzed by water to generate 1,3BG, while high-boiling substances are sometimes generated by polymerization of 1,3BG, and trace impurities are also generated and disappear. Therefore, the material balance in the product column may not be obtained. This can also be said of other distillation columns such as the dealcoholization column (low-boiling removal column), the dehydration column, and the high-boiling removal column.

[0104] [1,3-Butanediol products]

[0105] The 1,3-butanediol product disclosed in the present invention can be obtained by the manufacturing method disclosed above. The 1,3-butanediol product disclosed in the present invention has an initial boiling point higher than 203°C and a water content of less than 0.4% by weight. The initial boiling point is preferably above 204°C, more preferably above 205°C, further preferably above 206°C or 207°C, and particularly preferably above 208°C. The water content is preferably below 0.3% by weight, more preferably below 0.2% by weight, further preferably below 0.1% by weight, below 0.07% by weight, below 0.05% by weight, below 0.03% by weight, below 0.02% by weight or below 0.01% by weight, and particularly preferably below 0.005% by weight. It should be noted that the water content can be quantified using a Karl Fischer moisture analyzer.

[0106] Furthermore, in the 1,3-butanediol product of the present disclosure, in gas chromatography analysis (GC analysis) under the following conditions, the area ratio of the 1,3-butanediol peak is preferably higher than 98.5%, and the total area ratio of peaks having a shorter retention time than the 1,3-butanediol peak is preferably lower than 0.3%.

[0107] (Conditions for gas chromatography analysis)

[0108] Analytical column: a column with dimethylpolysiloxane as the stationary phase (film thickness 1.0 μm×length 30 m×inner diameter 0.25 mm).

[0109] Heating conditions: After heating from 80°C to 120°C at 5°C / min, heating to 160°C at 2°C / min and maintaining for 2 minutes, heating to 230°C at 10°C / min and maintaining at 230°C for 18 minutes.

[0110] Sample introduction temperature: 250°C.

[0111] Carrier gas: Helium.

[0112] Column gas flow rate: 1 mL / min.

[0113] Detector and detection temperature: hydrogen flame ionization detector (FID), 280°C.

[0114] The area ratio of the peak of the 1,3-butanediol is preferably 98.6% or more, more preferably 98.7% or more, further preferably 98.8% or more, 98.9% or more, 99% or more, 99.1% or more, 99.2% or more, 99.3% or more, 99.4% or more, 99.5% or more, 99.6% or more, or 99.7% or more, and particularly preferably 99.8% or more.

[0115] The total area ratio of the peaks having a shorter retention time than the peak of 1,3-butanediol is preferably 0.25% or less, more preferably 0.23% or less, further preferably 0.2% or less, 0.17% or less, 0.15% or less, 0.12% or less, 0.1% or less, 0.07% or less, 0.04% or less, 0.03% or less, 0.02% or less, 0.01% or less, or 0.007% or less, and particularly preferably 0.005% or less (e.g., 0.002% or less).

[0116] It should be noted that in the present disclosure, the "area ratio" of a peak refers to the ratio (area %) of the area of ​​a specific peak appearing in a spectrum to the sum of the areas of all peaks. In addition, all peaks refer to, for example, all peaks that appear when the relative retention time of the peak of 1,3-butanediol is set to 1.0 and the analysis is continued until the relative retention time reaches 7.8 and then stopped.

[0117] By setting the area ratio of the 1,3-butanediol peak and the total area ratio of peaks having a shorter retention time than the 1,3-butanediol peak to the above ranges, a high-purity and high-quality 1,3-butanediol product can be provided.

[0118] [Moisturizers and cosmetics]

[0119] The moisturizer disclosed in the present invention contains the above-mentioned 1,3-butanediol product. Therefore, the moisturizing performance is excellent. The moisturizer disclosed in the present invention may also contain ingredients other than the above-mentioned 1,3-butanediol product, for example, moisturizer ingredients other than the above-mentioned 1,3-butanediol product, etc. In the moisturizer disclosed in the present invention, the content of the above-mentioned 1,3-butanediol product is, for example, 10% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more, further preferably 80% by weight or more, particularly preferably 90% by weight or more, and may also be composed only of the above-mentioned 1,3-butanediol product.

[0120] The cosmetic disclosed herein contains the above-mentioned moisturizing agent. Depending on the type and form of the cosmetic, the amount of the above-mentioned 1,3-butanediol product in the cosmetic disclosed herein can be an amount that can exert moisturizing performance. The amount of the above-mentioned 1,3-butanediol product in the cosmetic disclosed herein is, for example, 0.01 to 40% by weight, preferably 0.1 to 30% by weight, more preferably 0.2 to 20% by weight, further preferably 0.5 to 15% by weight, and particularly preferably 1 to 10% by weight.

[0121] In addition to the above-mentioned 1,3-butylene glycol products, the cosmetics disclosed in the present invention may also include, for example: other moisturizers; oils such as vegetable oils, hydrocarbon oils, higher fatty acids, higher alcohols, and silicones; surfactants such as anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants; preservatives, chelating agents, thickeners, powders, ultraviolet absorbers, ultraviolet shielding agents, fragrances, and pH adjusters; vitamins, skin activators, blood circulation promoters, whitening agents, antibacterial agents, anti-inflammatory agents, and other medicinal ingredients, physiologically active ingredients, etc.

[0122] The cosmetics disclosed in the present invention can be made into skin cosmetics such as lotions, emulsions, creams, gels, facial masks (packs), facial masks, etc.; hair cosmetics such as shampoos, conditioners, and hair growth agents. In addition, they can also be made into sunscreen cosmetics, makeup cosmetics, etc. In addition, they can also be made into pharmaceuticals and quasi-drugs containing medical ingredients.

[0123] The cosmetic disclosed in the present invention can be produced by utilizing a method known per se.

[0124] It should be noted that the various schemes disclosed in this specification can be combined with any other features disclosed in this specification. In addition, each configuration and the combination of each configuration in each embodiment is an example, and the addition, omission and other changes of the configuration can be appropriately made within the scope of the main purpose of the present disclosure. The present disclosure is not limited by the embodiments, but only by the claims.

[0125] Example

[0126] Hereinafter, the present disclosure will be described in more detail by way of examples, but the present disclosure is not limited by these examples. It should be noted that the "parts" used in the examples refer to "parts by weight" unless otherwise specified. Gas chromatography analysis (GC analysis), determination of initial boiling point, and determination of water content were performed by the methods described below.

[0127] [Example 1]

[0128] use Figure 1 The method for producing 1,3-butanediol will be described.

[0129] With respect to 100 parts of a butanol aldehyde solution containing 30% by weight of water as a raw material (a mixed solution of 69 parts of butanol aldehyde and 29 parts of water, containing 2 parts in total of low-boiling and high-boiling impurities, and less than 0.1 parts of Na salt), 10 parts of hydrogen were charged into a reactor for liquid-phase hydrogen reduction, 15 parts of Raney nickel as a catalyst were added, and the reactor was maintained at 120° C. and 10 MPa (gauge pressure) to carry out liquid-phase hydrogen reduction. After the catalyst was separated from the liquid after the reaction, it was neutralized with caustic soda to obtain crude 1,3-butanediol (1) containing low-boiling impurities and water.

[0130] The butanol aldehyde solution containing 30 wt% of water used as a raw material was produced by stirring acetaldehyde and water in the presence of 100 wtppm of NaOH at 30°C for a residence time of 10 hours to dimerize acetaldehyde [acetaldehyde polymerization step (acetaldehyde aldol condensation step)].

[0131] The crude 1,3-butanediol (1) (equivalent to Figure 1 "X-1" in the figure) was loaded into dehydration tower A. In dehydration tower A, water was extracted from the top of the tower relative to 100 parts of the loading liquid, 15 parts of fresh water was added as reflux water, the top pressure was set to 7 kPa (absolute pressure), and crude 1,3-butanediol (2) with a water content of 1 wt% and a total area ratio of 1.8% of impurity peaks with a shorter retention time (RT) than 1,3-butanediol in the GC analysis described later was obtained from the bottom of the tower. It should be noted that the water extracted from the top of the tower was discharged (equivalent to Figure 1 2 in the figure).

[0132] Next, the crude 1,3-butanediol (2) is fed to the demineralization tower B. In the demineralization tower B, salt, high boiling point substances and part of the 1,3-butanediol are discharged from the bottom of the tower as an evaporation residue (equivalent to Figure 1 The discharge amount of the evaporation residue was 5 parts with respect to 100 parts of the loading liquid. On the other hand, crude 1,3-butanediol (3) containing 1,3-butanediol, low boiling point substances, and a part of high boiling point substances was obtained from the top of the column.

[0133] Next, the crude 1,3-butanediol (3) was charged into the high boiling point removal column C. In the high boiling point removal column C, distillation was performed under the condition of a column top pressure of 5 kPa (absolute pressure), and high boiling point substances and a part of 1,3-butanediol (equivalent to Figure 1 The amount of the column bottom discharge was 20 parts relative to 100 parts of the loading liquid. On the other hand, 80 parts of crude 1,3-butanediol (4) containing low boiling point substances was obtained as a distillate from the top of the column.

[0134] Next, crude 1,3-butanediol (4) was charged into the alkali reactor D. At this time, a 20 wt% aqueous caustic soda solution was added so that the concentration of caustic soda relative to the charge liquid became 0.1 wt%. The reaction temperature in the alkali reactor D was maintained at 120°C, and the reaction was carried out with a residence time of 20 minutes.

[0135] Next, the crude reaction liquid discharged from the alkali reactor D is fed into the dealkalization tower E. In the dealkalization tower E, caustic soda, high boiling point substances, and a portion of 1,3-butanediol (relative to Figure 1 "X-5" in the column). The amount of discharge from the bottom of the column was 5 parts relative to 100 parts of the loading liquid. On the other hand, 95 parts of crude 1,3-butanediol (5) containing 1,3-butanediol and low boiling point substances were obtained from the top of the column. The crude 1,3-butanediol (5) containing 1,3-butanediol and low boiling point substances was measured for water content and analyzed by GC. The results showed that the water concentration was 1.2% by weight, the area ratio of 1,3-butanediol was 97%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 1.8%.

[0136] Next, the crude 1,3-butanediol (5) was charged to the product distillation column F. In the product distillation column F, 10 parts (equivalent to 100 parts) of low boiling point substances and a portion of 1,3-butanediol were distilled from the top of the column. Figure 1 The whole amount was discharged out of the system. The reflux ratio (reflux amount / distillate amount) was 0.3 at this time, and 90 parts of 1,3-butanediol product (distillate rate 10% by weight) were obtained from the bottom of the tower (equivalent to Figure 1 in the text box).

[0137] The initial boiling point and water content of the obtained 1,3-butanediol product were measured and analyzed by GC. The results showed that the initial boiling point was 203.3°C, the water content was 0.2% by weight, the area ratio of 1,3-butanediol was 98.6%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 0.2% (retention time of 1,3-butanediol: 6.5 minutes). The recovery rate of 1,3-butanediol in product column F was 92%.

[0138] [Example 2]

[0139] Except that the reflux ratio of product tower F was changed to 1, 93 parts of 1,3-butanediol product were obtained from the bottom of product tower F by the same method as in Example 1. The initial boiling point, water content and GC analysis of the obtained 1,3-butanediol product showed that the initial boiling point was 206.8°C, the water concentration was 0.1% by weight, the area ratio of 1,3-butanediol was 98.7%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 0.09%. The recovery rate of 1,3-butanediol in product tower F was 92%.

[0140] [Example 3]

[0141] The reflux ratio of product tower F was set to 1, and the distillate of product tower F was extracted out of the system and the entire amount was recycled in the charging line of dehydration tower A. In addition, 90 parts of 1,3-butanediol product (distillation rate 10% by weight) were obtained from the bottom of product tower F by the same method as in Example 1. The initial boiling point, water content and GC analysis of the obtained 1,3-butanediol product were determined. The initial boiling point was 206.7°C, the water concentration was 0.1% by weight, the area ratio of 1,3-butanediol was 98.7%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 0.09%. The recovery rate of 1,3-butanediol in product tower F was more than 99%.

[0142] [Example 4]

[0143] Except that the reflux ratio of product tower F was set to 10, 90 parts of 1,3-butanediol product were obtained from the bottom of product tower F by the same method as in Example 3. The initial boiling point, water content and GC analysis of the obtained 1,3-butanediol product showed that the initial boiling point was 208.2°C, the water concentration was 0.01% by weight, the area ratio of 1,3-butanediol was 98.8%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 0.03%. The recovery rate of 1,3-butanediol in product tower F was 99% or more.

[0144] [Example 5]

[0145] Except that the reflux ratio of product tower F was set to 20, 90 parts of 1,3-butanediol product were obtained from the bottom of product tower F by the same method as in Example 3. The initial boiling point, water content and GC analysis of the obtained 1,3-butanediol product showed that the initial boiling point was 208.3°C, the water concentration was 0.008% by weight, the area ratio of 1,3-butanediol was 98.8%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 0.009%. The recovery rate of 1,3-butanediol in product tower F was 99% or more.

[0146] [Example 6]

[0147] 90 parts of 1,3-butanediol product were obtained from the bottom of product tower F by the same method as in Example 3 except that the reflux ratio of product tower F was set to 50. The initial boiling point, water content and GC analysis of the obtained 1,3-butanediol product showed that the initial boiling point was 208.3°C, the water concentration was 0.006% by weight, the area ratio of 1,3-butanediol was 98.8%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 0.007%. The recovery rate of 1,3-butanediol in product tower F was 99% or more.

[0148] [Example 7]

[0149] As the feed liquid to the product column F, a liquid having a water concentration of 0.4 wt%, an area ratio of 1,3-butanediol of 98%, and a total area ratio of 0.7% of impurity peaks with a shorter retention time than 1,3-butanediol was used, and the reflux ratio of the product column F was set to 1, and 99 parts of a 1,3-butanediol product (distillation rate 1 wt%) were obtained from the bottom of the product column F. The same operation as in Example 3 was performed. The initial boiling point and water content of the obtained 1,3-butanediol product were measured and analyzed by GC. The results showed that the initial boiling point was 206.9°C, the water concentration was 0.1 wt%, the area ratio of 1,3-butanediol was 98.6%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 0.07%. The recovery rate of 1,3-butanediol in the product column F was 99% or more.

[0150] [Example 8]

[0151] The same operation as in Example 7 was performed except that the reflux ratio of the product column F was set to 5. The initial boiling point, water content, and GC analysis of the obtained 1,3-butanediol product were determined. The initial boiling point was 208.3°C, the water concentration was 0.008% by weight, the area ratio of 1,3-butanediol was 98.7%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 0.009%. The recovery rate of 1,3-butanediol in the product column F was 99% or more.

[0152] [Example 9]

[0153] The same operation as in Example 7 was performed except that the reflux ratio of the product column F was set to 10. The initial boiling point, water content, and GC analysis of the obtained 1,3-butanediol product were determined. The initial boiling point was 208.3°C, the water concentration was 0.006% by weight, the area ratio of 1,3-butanediol was 98.7%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 0.007%. The recovery rate of 1,3-butanediol in the product column F was 99% or more.

[0154] [Example 10]

[0155] The same operation as in Example 7 was performed except that the reflux ratio of the product column F was set to 100. The initial boiling point, water content, and GC analysis of the obtained 1,3-butanediol product were determined. The initial boiling point was 208.3°C, the water concentration was 0.005% by weight, the area ratio of 1,3-butanediol was 98.7%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 0.005%. The recovery rate of 1,3-butanediol in the product column F was 99% or more.

[0156] [Example 11]

[0157] The same operation as in Example 7 was performed except that the reflux ratio of the product column F was set to 500. The initial boiling point, water content, and GC analysis of the obtained 1,3-butanediol product were determined. The initial boiling point was 208.4°C, the water concentration was 0.004% by weight, the area ratio of 1,3-butanediol was 98.7%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 0.004%. The recovery rate of 1,3-butanediol in the product column F was 99% or more.

[0158] [Example 12]

[0159] As the feed liquid to the product column F, a liquid having a water concentration of 0.1% by weight, an area ratio of 1,3-butanediol of 99%, and a total area ratio of 0.6% of impurity peaks with a shorter retention time than 1,3-butanediol was used, and the reflux ratio of the product column F was set to 10, and 99.7 parts of a 1,3-butanediol product (distillation rate of 0.3% by weight) were obtained from the bottom of the product column F. The same operation as in Example 3 was performed. The initial boiling point and water content of the obtained 1,3-butanediol product were measured and analyzed by GC. The results showed that the initial boiling point was 208.2°C, the water concentration was 0.01% by weight, the area ratio of 1,3-butanediol was 99.5%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 0.1%. The recovery rate of 1,3-butanediol in the product column F was 99% or more.

[0160] [Example 13]

[0161] As the feed liquid to the product column F, a liquid having a water concentration of 3 wt%, an area ratio of 1,3-butanediol of 99%, and a total area ratio of impurity peaks having a shorter retention time than 1,3-butanediol of 0.8% was used, and the reflux ratio of the product column F was set to 10, and 90 parts of a 1,3-butanediol product (distillation rate of 10 wt%) were obtained from the bottom of the product column F. The same operation as in Example 3 was performed. The initial boiling point, water content, and GC analysis of the obtained 1,3-butanediol product were measured, and the results showed that the initial boiling point was 206.7°C, the water concentration was 0.1 wt%, the area ratio of 1,3-butanediol was 99.4%, and the total area ratio of impurity peaks having a shorter retention time than 1,3-butanediol was 0.02%. The recovery rate of 1,3-butanediol in the product column F was 99% or more.

[0162] [Comparative Example 1]

[0163] The same operation as in Example 1 was performed except that the reflux ratio of the product tower F was set to 0.05 and 80 parts of 1,3-butanediol product (distillation rate 20 wt%) were obtained from the bottom of the product tower F. The initial boiling point, water content and GC analysis of the obtained 1,3-butanediol product were determined. The initial boiling point was 194.6°C, the water concentration was 0.6 wt%, the area ratio of 1,3-butanediol was 98.5%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 0.3%. The recovery rate of 1,3-butanediol in the product tower F was 82%.

[0164] [Comparative Example 2]

[0165] The same operation as in Example 1 was performed except that the reflux ratio of the product tower F was set to 0.1 and 80 parts of 1,3-butanediol product (distillation rate 20 wt%) were obtained from the bottom of the product tower F. The initial boiling point, water content and GC analysis of the obtained 1,3-butanediol product were determined. The initial boiling point was 199.0°C, the water concentration was 0.4 wt%, the area ratio of 1,3-butanediol was 98.6%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 0.2%. The recovery rate of 1,3-butanediol in the product tower F was 82%.

[0166] [Reference Example 1]

[0167] The same operation as in Example 1 was performed except that the reflux ratio of the product tower F was set to 0.1 and 70 parts of 1,3-butanediol product (distillation rate 30 wt%) were obtained from the bottom of the product tower F. The initial boiling point, water content and GC analysis of the obtained 1,3-butanediol product were determined. The initial boiling point was 203.1°C, the water concentration was 0.2 wt%, the area ratio of 1,3-butanediol was 98.7%, and the total area ratio of impurity peaks with a shorter retention time than 1,3-butanediol was 0.1%. The recovery rate of 1,3-butanediol in the product tower F was 72%.

[0168] [Gas chromatography analysis]

[0169] The gas chromatography analysis of the target 1,3-butanediol product was carried out under the following conditions. The gas chromatography analysis spectrum of the 1,3-butanediol product in Example 12 is shown in FIG. Figure 2 In addition, the gas chromatography spectrum of the 1,3-butanediol product in Comparative Example 2 is shown in Figure 3 .

[0170] (Conditions for gas chromatography analysis)

[0171] Analytical equipment: Shimadzu GC2010.

[0172] Analytical column: a column having a dimethylpolysiloxane stationary phase (film thickness 1.0 μm×length 30 m×inner diameter 0.25 mm) (“Agilent J&W GC column-DB-1”, manufactured by Agilent Technologies, Inc.).

[0173] Heating conditions: After heating from 80°C to 120°C at 5°C / min, heating to 160°C at 2°C / min and maintaining for 2 minutes, heating to 230°C at 10°C / min and maintaining at 230°C for 18 minutes.

[0174] Sample introduction and temperature: split sample introduction method, 250°C.

[0175] Gas flow rate of slit and carrier gas: 23 mL / min, helium.

[0176] Column gas flow and carrier gas: 1 mL / min, helium.

[0177] Detector and temperature: flame ionization detector (FID), 280°C.

[0178] Injection sample: 0.2 μL of 80 wt% 1,3-butanediol product aqueous solution.

[0179] [Determination of initial boiling point]

[0180] The test was carried out in accordance with the test method specified in the atmospheric distillation test method of JIS K2254 "Petroleum products - Distillation test methods".

[0181] [Determination of water content]

[0182] The test was carried out using a Karl Fischer moisture analyzer.

[0183] [Results]

[0184] Tables 1 and 2 show the results of the comparative examples, reference examples, and examples.

[0185] [Table 1]

[0186]

[0187] [Table 2]

[0188]

[0189]

[0190] According to Comparative Examples 1 and 2, when the distillation rate was 20 wt%, even if the reflux ratio was 0.1, the removal effect of water and low-boiling impurities was low, and the product initial boiling point could not reach a satisfactory value. In Reference Example 1, when the distillation rate was set to 30 wt%, although the reflux ratio was 0.1 and the product initial boiling point could be satisfied, the 1,3BG recovery rate in the product column deteriorated to 72%, which was economically disadvantageous.

[0191] According to Comparative Examples 1 to 2, Reference Example 1, and Example 1, when the reflux ratio of the product tower was changed from 0.1 to 0.3, the distillation rate was 10% by weight (92% recovery rate) and the amount of water and low-boiling components removed from the product tower distillate increased. Therefore, the concentration of water and low-boiling components in the product decreased, and as a result, the initial boiling point of the product tower residual liquid (product) increased. It can be seen that if the charge composition (especially water, or water and low-boiling components) is controlled and the reflux ratio and distillation amount are controlled, the quality can be maintained at a certain degree of recovery even at a relatively low reflux ratio.

[0192] According to Examples 1 and 2, when the reflux ratio of the product column was increased from 0.3 to 1, the amount of water and low-boiling components removed from the product column distillate increased. Therefore, the concentration of water and low-boiling components in the product decreased, and as a result, the initial boiling point of the product residue liquid (product) increased.

[0193] When comparing Examples 2 and 3, by recycling the product tower distillate, the 1,3BG recovery rate was increased while obtaining approximately the same product quality. This is because the water and low-boiling impurities contained in the product tower distillate were almost completely removed by distillation in the dehydration tower.

[0194] According to Examples 3 to 6, when the reflux ratio is increased, the water content and low boiling component concentrations of the product are further reduced, and the initial boiling point is increased.

[0195] According to Examples 2 and 7, if the purity of the product charge is increased and the concentration of water and low-boiling components is reduced, the product quality remains the same or improves even if the distillate amount is reduced. In addition, according to Examples 7 to 11, it can be seen that if the reflux ratio is increased, the quality of the product is improved, but if the reflux ratio is increased to 500, the improvement of the product quality becomes slow, and the effect is to reduce the amount of energy increase caused by the increase in the reflux amount.

[0196] According to Examples 4, 9, and 12, it is known that the product quality can be maintained even when the distillate amount and the purity of the charge liquid are changed while the reflux amount is constant. It is known that the distillate recycling amount also depends on the water content and impurity concentration of the charge liquid, but even if it is too low, the amount of water and impurities removed is extremely reduced, so there is a limit, but if the distillation rate is about 0.3% by weight, the quality can be maintained. The smaller the distillate recycling amount, the lower the increase in equipment size caused by recycling in the previous process and the increase in processing volume, so it is better to be as small as possible, but it is ideal to determine the optimal value in consideration of quality and the overall balance.

[0197] According to Example 13, even if the water concentration in the product column feed liquid is high, the product quality can be satisfied as long as the distillation rate and reflux ratio of the product column are set to a certain high value.

[0198] It should be noted that among the 1,3-butanediol products obtained by conventional methods, there is no high-quality product having an initial boiling point higher than 203° C. and a water content of less than 0.4% by weight.

[0199] As a summary of the above, the configuration of the present disclosure and its variations are supplementally described below.

[0200] [1] A method for producing 1,3-butanediol, the method comprising obtaining purified 1,3-butanediol from a crude reaction liquid containing 1,3-butanediol, the method comprising a dehydration step of removing water by distillation, a high boiling point removal step of removing high boiling point components by distillation, and a product distillation step for obtaining purified 1,3-butanediol, wherein a feed liquid containing 1,3-butanediol is distilled under a reflux ratio exceeding 0.1 (or 0.15 or more) in a product column used in the product distillation step, a liquid in which low boiling point components are concentrated is distilled from an upper portion of the feed layer, and 1,3-butanediol is extracted from a lower portion of the feed layer.

[0201] [2] The method for producing 1,3-butanediol according to [1], wherein the crude reaction liquid containing 1,3-butanediol is a crude reaction liquid obtained by hydrogen reduction of butanol aldehydes (or a crude reaction liquid obtained by hydrolysis of 1,3-butylene oxide, a crude reaction liquid obtained by selective hydrogenation and decomposition of erythritol, a crude reaction liquid obtained by selective addition of water to butadiene, a crude reaction liquid obtained by hydrogenation of n-butyraldehyde-3-one, a crude reaction liquid obtained by hydrogenation of 1-butanol-3-one, a crude reaction liquid obtained by hydrogenation of 3-hydroxy-1-butyric acid, a crude reaction liquid obtained by hydrogenation of β-butyrolactone, or a crude reaction liquid obtained by hydrogenation of diketene).

[0202] [3] The method for producing 1,3-butanediol according to [2], wherein the butanol aldehyde used as a raw material in the reduction (hydrogenation) of the butanol aldehyde is any one of butanol aldehyde, dimer m-hydroxybutyraldehyde which is a cyclic dimer thereof, 2,6-dimethyl-1,3-dioxane-4-ol which is a cyclic trimer of acetaldehyde, and a mixture thereof.

[0203] [4] The method for producing 1,3-butanediol according to [2] or [3], wherein the crude reaction liquid containing the butanol aldehydes is subjected to simple evaporation, distillation or hydrogenation to remove the aldehydes, followed by a hydrogenation step.

[0204] [5] A method for producing 1,3-butanediol according to any one of [2] to [4], wherein the content of butanol aldehydes used as raw materials in the reduction (hydrogenation) of butanol aldehydes is 30% by weight or more (e.g., 30 to 99% by weight) (or 40% by weight or more (e.g., 40 to 98% by weight), 50% by weight or more (e.g., 50 to 97% by weight), 60% by weight or more (e.g., 60 to 95% by weight), 65 to 90% by weight, 70 to 90% by weight, or 75 to 90% by weight).

[0205] [6] The method for producing 1,3-butanediol according to any one of [2] to [5], wherein the raw material for the reduction (hydrogenation) of the butanol aldehyde contains water, the water content is 2 weight % or more (or 5 weight % or more, 10 weight % or more, or 15 weight % or more), and the upper limit of the water content is 90 weight % (or 80 weight %, 70 weight %, 60 weight %, 50 weight %, 40 weight %, 30 weight % or 20 weight %).

[0206] [7] The method for producing 1,3-butanediol according to any one of [2] to [6], wherein the amount of the hydrogenation catalyst for the reduction (hydrogenation) of the butanol aldehydes is 1 to 30 parts by weight (or 4 to 25 parts by weight, 8 to 20 parts by weight, or 12 to 18 parts by weight) relative to 100 parts by weight of the hydrogenation raw material.

[0207] [8] The method for producing 1,3-butanediol according to any one of [2] to [7], wherein the amount of hydrogen used in the reduction (hydrogenation) reaction of the butanol aldehydes is 0.5 to 40 parts by weight (or 1 to 30 parts by weight, 4 to 20 parts by weight, or 8 to 12 parts by weight) relative to 100 parts by weight of the hydrogenation raw material.

[0208] [9] The method for producing 1,3-butanediol according to any one of [2] to [8], wherein the pressure (total pressure; gauge pressure) in the reaction system during the reduction (hydrogenation) reaction of the butanol aldehydes is 9 to 70 MPa (or 10 to 40 MPa).

[0209]

[10] The method for producing 1,3-butanediol according to any one of [2] to [9], wherein the hydrogen pressure (hydrogen partial pressure) in the reaction system during the reduction (hydrogenation) reaction of the butanol aldehydes is 7 to 60 MPa (or 10 to 30 MPa).

[0210]

[11] The method for producing 1,3-butanediol according to any one of [2] to

[10] , wherein the reaction temperature in the reduction (hydrogenation) reaction of the butanol aldehydes is 40 to 150° C. (or 50 to 140° C., or 60 to 130° C.).

[0211]

[12] The method for producing 1,3-butanediol according to any one of [2] to

[11] , wherein the reaction time (residence time) in the reduction (hydrogenation) reaction of the butanol aldehydes is 10 to 500 minutes (or 20 to 400 minutes, 30 to 300 minutes, 50 to 280 minutes, or 80 to 250 minutes).

[0212]

[13] The method for producing 1,3-butanediol according to any one of [1] to

[12] , further comprising a dealcoholization step of removing low boiling points including alcohol in a process stream including the 1,3-butanediol.

[0213]

[14] The method for producing 1,3-butanediol according to any one of [1] to

[13] , further comprising a desalting step of removing salt from a process stream containing the 1,3-butanediol.

[0214]

[15] The method for producing 1,3-butanediol according to

[14] , wherein the residual rate (%) in the desalination step [(desalting tower residual amount (parts) / desalting tower charge amount (parts))·100] is 0.1 to 40 weight % (or 1 to 35 weight %, 2 to 30 weight %, 3 to 25 weight %, 5 to 20 weight %, or 7 to 15 weight %).

[0215]

[16] A method for producing 1,3-butanediol according to any one of [1] to

[15] , wherein the high boiling tower used in the high boiling tower removal step is a packed tower (or a porous plate tower, or a bubble tower), and the reboiler used is a natural falling film evaporator or a forced stirring thin film evaporator.

[0216]

[17] The method for producing 1,3-butanediol according to

[16] , wherein the theoretical number of layers of the high boiling point removal tower is 1 to 100 layers (or 2 to 90 layers, 3 to 80 layers, 4 to 70 layers, 5 to 60 layers, 8 to 50 layers, 10 to 40 layers, or 15 to 30 layers).

[0217]

[18] The method for producing 1,3-butanediol according to

[16] or

[17] , wherein the feed liquid is supplied to a position at 10% to 90% (or 20% to 80%, 30% to 70%, or 40% to 60%) of the height of the tower downward from the top of the high boiling point removal tower.

[0218]

[19] The method for producing 1,3-butanediol according to any one of

[16] to

[18] , wherein in the distillation in the high boiling tower, the pressure (absolute pressure) at the top of the tower is 0.01 to 50 kPa (or 0.1 to 30 kPa, 0.3 to 20 kPa, or 0.5 to 10 kPa).

[0219]

[20] The method for producing 1,3-butanediol according to any one of

[16] to

[19] , wherein at least a portion of the residual liquid in the high boiling point removal tower is recycled to a step before the high boiling point removal step.

[0220]

[21] The method for producing 1,3-butanediol according to any one of

[16] to

[20] , wherein the reflux ratio of the high boiling point removal tower is set to 0.015 or more (or 0.02 or more, 0.03 or more, 0.05 or more, 0.07 or more, 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, 0.5 or more, 0.6 or more, 0.7 or more, 0.8 or more, 0.9 or more, 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 15 or more, 20 or more, or 30 or more).

[0221]

[22] The method for producing 1,3-butanediol according to

[21] , wherein the upper limit of the reflux ratio is 100 (or 50).

[0222]

[23] The method for producing 1,3-butanediol according to any one of [1] to

[22] , further comprising an alkali treatment step of treating a process stream containing the 1,3-butanediol with an alkali.

[0223]

[24] The method for producing 1,3-butanediol according to

[23] , wherein the amount of the alkali added in the alkali treatment is 0.05 to 10 wt% (or 0.1 to 1.0 wt%) relative to the crude 1,3-butanediol stream subjected to the alkali treatment.

[0224]

[25] The method for producing 1,3-butanediol according to

[23] or

[24] , wherein the base added in the alkali treatment is an alkali metal compound.

[0225]

[26] The method for producing 1,3-butanediol according to

[25] , wherein the alkali metal compound is sodium hydroxide (or potassium hydroxide, sodium (bi) carbonate or potassium (bi) carbonate).

[0226]

[27] The method for producing 1,3-butanediol according to any one of

[23] to

[26] , wherein the reaction temperature of the alkali treatment is 90 to 140°C (or 110 to 130°C), and the reaction residence time is 5 to 120 minutes (or 10 to 30 minutes).

[0227]

[28] The method for producing 1,3-butanediol according to any one of

[23] to

[27] , wherein, in the evaporator used for the alkali treatment, the top of the tower is evaporated at 90 to 120° C. under a reduced pressure of 20 kPa or less absolute pressure (or 0.5 to 10 kPa absolute pressure).

[0228]

[29] A method for producing 1,3-butanediol according to any one of [1] to

[28] , wherein the product tower used in the product distillation step is a packed tower (or a porous plate tower, or a bubble tower), and the reboiler used is a natural falling film evaporator or a forced stirring thin film evaporator.

[0229]

[30] The method for producing 1,3-butanediol according to

[29] , wherein the theoretical number of layers of the product tower is 1 to 100 layers (or 2 to 90 layers, 3 to 80 layers, 4 to 70 layers, 5 to 60 layers, 8 to 50 layers, 10 to 40 layers, or 15 to 30 layers).

[0230]

[31] The method for producing 1,3-butanediol according to

[29] or

[30] , wherein the feed liquid of the product tower is supplied from the top of the tower downward at a position of 10% to 90% (or 20% to 80%, 30% to 70%, or 40% to 60%) of the tower height, and the pressure (absolute pressure) at the top of the tower is 20 kPa or less (or 0.1 to 10 kPa, 0.3 to 8 kPa, or 0.5 to 5 kPa).

[0231]

[32] The method for producing 1,3-butanediol according to any one of

[29] to

[31] , wherein the reflux ratio in the product tower is 0.2 or more (or 0.3 or more, 0.4 or more, 0.5 or more, 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 20 or more, 50 or more, 400 or more, or 500 or more).

[0232]

[33] The method for producing 1,3-butanediol according to any one of

[29] to

[32] , wherein the concentration of 1,3-butanediol in the feed liquid to the product tower is 90% or more (or 91% or more, 92% or more, 93% or more, 94% or more, 95% or more, 96% or more, 97% or more, 98% or more, or 99% or more).

[0233]

[34] The method for producing 1,3-butanediol according to any one of

[29] to

[33] , wherein the water content in the feed liquid to the product tower is 3 weight % or less (or 2.8 weight % or less, 2.6 weight % or less, 2.4 weight % or less, 2.2 weight % or less, 2 weight % or less, 1.8 weight % or less, 1.6 weight % or less, 1.4 weight % or less, 1.4 weight % or less, 1.2 weight % or less, 1 weight % or less, 0.95 weight % or less, 0.9 weight % or less, 0.8 weight % or less, 0.7 weight % or less, 0.6 weight % or less, 0.5 weight % or less, 0.4 weight % or less, 0.3 weight % or less, 0.2 weight % or less, or 0.1 weight % or less).

[0234]

[35] A method for producing 1,3-butanediol according to any one of

[29] to

[34] , wherein the content of low-boiling point components other than water in the feed liquid to the product tower is 1.8% or less (or 1.6% or less, 1.4% or less, 1.2% or less, 1.1% or less, 1% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, or 0.4%).

[0235]

[36] The method for producing 1,3-butanediol according to any one of

[29] to

[35] , wherein the distillation rate in the product column is set to less than 30% by weight (or less than 29% by weight, less than 28% by weight, less than 27% by weight, less than 26% by weight, less than 25% by weight, less than 24% by weight, less than 23% by weight, less than 22% by weight, less than 21% by weight, or less than 20% by weight, 19% by weight or less, 18% by weight or less, 17% by weight or less, 16% by weight or less, 15% by weight or less, 12% by weight or less, 10% by weight or less, 8% by weight or less, 5% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, 0.8% by weight or less, 0.6% by weight or less, or 0.4% by weight or less).

[0236]

[37] The method for producing 1,3-butanediol according to any one of

[29] to

[36] , wherein at least a portion of the distillate from the product tower is recycled to a dehydration step, a dealcoholization step, a low boiling point removal step, or a step before these steps, which are steps before the product distillation step.

[0237]

[38] The method for producing 1,3-butanediol according to

[37] , wherein the amount of the distillate from the product tower recycled to the step before the product distillation step is within a range below the distillate amount in the product tower and is less than 30% by weight relative to the charge amount to the product tower.

[0238]

[39] The method for producing 1,3-butanediol according to

[37] or

[38] , wherein the amount of the distillate from the product tower recycled to the step before the product distillation step is 0.01% by weight or more (or 0.05% by weight or more, 0.1% by weight or more, 0.5% by weight or more, 1% by weight or more, 1.5% by weight or more, 2% by weight or more, 3% by weight or more, 4% by weight or more, 5% by weight or more, 7% by weight or more, 10% by weight or more, or 20% by weight or more) relative to the amount of material charged to the product tower.

[0239]

[40] A 1,3-butanediol product having an initial boiling point higher than 203°C (or higher than 204°C, higher than 05°C, higher than 206°C, higher than 207°C, or higher than 208°C), and a water content of less than 0.4% by weight (or lower than 0.3% by weight, lower than 0.2% by weight, lower than 0.1% by weight, lower than 0.07% by weight, lower than 0.05% by weight, lower than 0.03% by weight, lower than 0.02% by weight, lower than 0.01% by weight, or lower than 0.005% by weight).

[0240]

[41] The 1,3-butanediol product according to

[40] , wherein the area ratio of the peak of 1,3-butanediol is higher than 98.5% (or 98.6% or more, 98.7% or more, 98.8% or more, 98.9% or more, 99% or more, 99.1% or more, 99.2% or more, 99.3% or more, 99.4% or more, 99.5% or more, 99.6% or more, 99.7% or more, or 99.8% or more). .8% or more), and the total area ratio of peaks with shorter retention times than the peak of 1,3-butanediol is less than 0.3% (or is 0.25% or less, 0.23% or less, 0.2% or less, 0.17% or less, 0.15% or less, 0.12% or less, 0.1% or less, 0.07% or less, 0.04% or less, 0.03% or less, 0.02% or less, 0.01% or less, 0.007% or less, 0.005% or less, or 0.002% or less).

[0241] (Conditions for gas chromatography analysis)

[0242] Analytical column: a column with dimethylpolysiloxane as the stationary phase (film thickness 1.0 μm×length 30 m×inner diameter 0.25 mm).

[0243] Heating conditions: After heating from 80°C to 120°C at 5°C / min, heating to 160°C at 2°C / min and maintaining for 2 minutes, heating to 230°C at 10°C / min and maintaining at 230°C for 18 minutes.

[0244] Sample introduction temperature: 250°C.

[0245] Carrier gas: Helium.

[0246] Column gas flow rate: 1 mL / min.

[0247] Detector and detection temperature: hydrogen flame ionization detector (FID), 280°C.

[0248]

[42] A moisturizer comprising the 1,3-butanediol preparation described in

[40] or

[41] .

[0249]

[43] The moisturizing agent according to

[42] , wherein the content of the 1,3-butanediol product is 10 wt% or more (or 30 wt% or more, 50 wt% or more, 80 wt% or more, 90 wt% or more, or 100 wt%).

[0250]

[44] A cosmetic comprising the moisturizing agent described in

[42] or

[43] .

[0251]

[45] The cosmetic according to

[44] , wherein the amount of the 1,3-butanediol product is 0.01 to 40 wt% (or 0.1 to 30 wt%, 0.2 to 20 wt%, 0.5 to 15 wt%, or 1 to 10 wt%).

[0252] Industrial Applicability

[0253] The 1,3-butanediol product disclosed in the present invention can produce high-purity 1,3-butanediol with a very small content of low-boiling-point components and a high initial boiling point at a high recovery rate. The 1,3-butanediol product has excellent moisturizing properties and can be used as a raw material for moisturizers and cosmetics that can maintain high quality for a long time.

[0254] Description of Reference Numerals

[0255] A: Dehydration tower

[0256] B: Desalination tower

[0257] C: High boiling point removal distillation tower (high boiling point removal tower)

[0258] D: Alkali Reactor

[0259] E: Dealkalization Tower

[0260] F: Product distillation tower (product tower)

[0261] A-1, B-1, C-1, E-1, F-1: Condenser

[0262] A-2, C-2, F-2: Reboiler

[0263] X-1: Crude 1,3-butanediol

[0264] X-2: Water (drainage)

[0265] X-3: Salt, high boiling point substances and part of 1,3-butanediol

[0266] X-4: high boiling point substances and part of 1,3-butanediol

[0267] X-5: caustic soda, high boiling point substances and part of 1,3-butanediol

[0268] X-6: Low boiling point substances and part of 1,3-butanediol

[0269] Y: 1,3-Butanediol products

Claims

1. A method for producing 1,3-butanediol, which is a method for producing 1,3-butanediol by obtaining purified 1,3-butanediol from a crude reaction liquid containing 1,3-butanediol, wherein: The production method comprises a dehydration step of removing water by distillation, a high boiling point removal step of removing high boiling point components by distillation, and a product distillation step for obtaining purified 1,3-butanediol. In the product column used in the product distillation step, the water content in the charge liquid containing 1,3-butanediol is 3% by weight or less, the charge liquid is distilled under the condition of a reflux ratio of 3 or more, a liquid in which low boiling point components are concentrated is distilled from the upper part of the charge layer, and 1,3-butanediol is extracted from the lower part of the charge layer.

2. The method for producing 1,3-butanediol according to claim 1, wherein The crude reaction liquid containing 1,3-butanediol is a crude reaction liquid obtained by hydrogen reduction of butanol aldehydes.

3. The method for producing 1,3-butanediol according to claim 1 or 2, further comprising: An alkali treatment process for treating a process stream comprising 1,3-butanediol with an alkali.

4. The method for producing 1,3-butanediol according to claim 1 or 2, further comprising: A desalination process for removing salts from a process stream comprising 1,3-butanediol.

5. The method for producing 1,3-butanediol according to claim 1 or 2, further comprising: A de-alcoholization step for removing low boilers comprising alcohol from a process stream comprising 1,3-butanediol.

6. The method for producing 1,3-butanediol according to claim 1 or 2, wherein The concentration of 1,3-butanediol in the feed liquid to the product column is 90% or more.

7. The method for producing 1,3-butanediol according to claim 1 or 2, wherein The content of low-boiling-point components other than water in the feed liquid to the product column is 1.8% or less.

8. The method for producing 1,3-butanediol according to claim 1 or 2, wherein The distillation rate in the product column is set to less than 30% by weight.

9. The method for producing 1,3-butanediol according to claim 1 or 2, wherein The theoretical number of layers of the product tower is 1 to 100.

10. The method for producing 1,3-butanediol according to claim 1 or 2, wherein At least a portion of the distillate from the product column is recycled to a dehydration step, a dealcoholization step, a low boiling point removal step, or a step before these steps, which are steps before the product distillation step.

11. The method for producing 1,3-butanediol according to claim 10, wherein The amount of the distillate from the product column recycled to the step before the product distillation step is within a range not exceeding the amount distilled from the product column and is less than 30% by weight relative to the amount charged to the product column.

12. The method for producing 1,3-butanediol according to claim 10, wherein The amount of the distillate from the product column recycled to a step before the product distillation step is within a range not greater than the amount distilled from the product column and is 0.01% by weight or more relative to the amount charged to the product column.

13. A 1,3-butanediol product produced by the method for producing 1,3-butanediol according to any one of claims 1 to 12, The 1,3-butanediol product has an initial boiling point higher than 203° C. and a water content of less than 0.4% by weight.

14. The 1,3-butanediol product according to claim 13, wherein in a gas chromatography analysis under the following conditions, the area ratio of the 1,3-butanediol peak is higher than 98.5%, and the total area ratio of peaks having a shorter retention time than the 1,3-butanediol peak is lower than 0.3%, Gas chromatography analysis conditions: Analytical column: The stationary phase is dimethylpolysiloxane, with a film thickness of 1.0 μm × length of 30 m × inner diameter of 0.25 mm; Heating conditions: After heating from 80°C to 120°C at 5°C / min, heating to 160°C at 2°C / min and maintaining for 2 minutes, further heating to 230°C at 10°C / min and maintaining at 230°C for 18 minutes; Sample introduction temperature: 250℃; Carrier gas: helium; Column gas flow rate: 1 mL / min; Detector and detection temperature: hydrogen flame ionization detector (FID), 280°C.

15. A moisturizer comprising the 1,3-butanediol product according to claim 13 or 14.

16. A cosmetic comprising the moisturizing agent according to claim 15.

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