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

Abstract

Provided is a method for producing high-purity 1, 3-butanediol having an extremely low content of low-boiling-point components, a high initial boiling point, and a high recovery rate. A crude reaction solution containing 1, 3-butanediol is subjected to a dehydration step in which water is removed by distillation, and a high-boiling-point removal step in which high-boiling-point components are removed by distillation, and is supplied to a product distillation step in which purified 1, 3-butanediol is obtained. A method for producing 1, 3-butanediol, in which a charging liquid having a water content of 1.2 wt% or less is distilled under conditions in which the reflux ratio exceeds 0.1 in a product tower used in the product distillation step, a liquid in which a low-boiling-point component is concentrated is distilled from above the charging layer, and 1, 3-butanediol is extracted from below the charging layer.

Description

[0001] This application is a divisional application of an application with an application date of December 23, 2020, an application number of 202080090574.6, and an invention title of "Method for Producing 1,3-Butanediol and 1,3-Butanediol Product". Technical Field

[0002] The present disclosure relates to a method for producing 1,3-butanediol and a 1,3-butanediol product. This application claims the priority of Japanese Patent Application Nos. 2019-239974, 2019-239975, 2019-239976, 2019-239977, 2019-239978, 2019-239979 filed in Japan on December 28, 2019, Japanese Patent Application No. 2020-006660 filed in Japan on January 20, 2020, and Japanese Patent Application No. 2020-018910 filed in Japan on February 6, 2020, and incorporates their contents herein by reference. Background Art

[0003] 1,3-Butanediol is a colorless, transparent, and odorless liquid, having properties such as low volatility, low toxicity, and high hygroscopicity, and excellent chemical stability. Therefore, the uses of 1,3-butanediol include, among others, raw materials for various synthetic resins and surfactants, and span multiple aspects such as cosmetics, hygroscopic agents, high-boiling solvents, and raw materials for antifreeze. In particular, in recent years, 1,3-butanediol has attracted attention for its excellent properties as a humectant, and the demand in the cosmetics industry has expanded.

[0004] The reaction crude liquid in the production of 1,3-butanediol contains a large amount of low-boiling impurities such as ethanol, butanol, acetaldehyde, crotonaldehyde, and esters. When acetaldehyde, crotonaldehyde, etc. dimerize or polymerize to a level above 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, etc. In the 1,3-butanediol product, the fewer such impurities, the more preferable. Japanese Patent Laid-Open No. 6-329664 discloses a method for controlling impurities derived from crotonaldehyde as a low-boiling impurity. Japanese Patent Laid-Open No. 2001-213828 discloses that when the reaction crude liquid of 1,3-butanediol synthesized by the hydrogenation of aldol butanols is made alkaline, and after distilling off the alcohol, distillation is carried out, a 1,3-butanediol product with high purity can be produced with good yield and economically advantageously. In addition, this document describes the distillation removal of ethanol, isopropanol, and butanol as low-boiling impurities.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Laid-Open No. 6-329664

[0008] Patent Document 2: Japanese Patent Laid-Open No. 2001-213828 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] However, in the conventional method, the removal of low-boiling components and high-boiling components from 1,3-butanediol is not sufficient. Cosmetics, which are an important use of 1,3-butanediol, usually contain water and require a long time from manufacture to actual use by ordinary consumers. In addition, for cosmetics, the liquidity is strictly adjusted from the viewpoints of storage stability and the like.

[0011] When 1,3-butanediol containing low-boiling components and high-boiling components is used in cosmetics, the liquidity balance of the cosmetics is lost due to the increase in acid concentration, and the original effects that should be exhibited may be lost. In addition, due to the increase in the acid concentration of the cosmetics, skin roughness of users may also occur.

[0012] Moreover, when using cosmetics and during storage after use, the cosmetics are exposed to air. In addition, when manufacturing cosmetics, operations are usually carried out in an air atmosphere, and heating is sometimes performed for sterilization and other purposes. When 1,3-butanediol containing low-boiling components and high-boiling components is used in cosmetics, coloring sometimes occurs due to the presence of air and the influence of heating.

[0013] In order to solve such problems, it is required to remove by-products from crude 1,3-butanediol and purify 1,3-butanediol to a high purity.

[0014] On the other hand, one of the quality standards 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, almost no technical research has been carried out for the purpose of increasing the initial boiling point.

[0015] Therefore, an object of the present disclosure is to provide a method for manufacturing high-purity 1,3-butanediol with a very low content of low-boiling components and a high initial boiling point at a high recovery rate.

[0016] Another object of the present disclosure is to provide a high-purity 1,3-butanediol product with a very low content of low-boiling components and a high initial boiling point.

[0017] Still another object of the present disclosure is to provide a humectant and a cosmetic having excellent moisturizing performance and capable of maintaining high quality for a long time.

[0018] Technical Solution

[0019] The inventors of the present disclosure have conducted in-depth research to achieve the above object, and as a result, it has been found that if the water content in the charging liquid to the product column is specified and the reflux ratio of the product column is controlled, or the product column distillate is recycled to the dehydration column and the low-boiling component removal column, the low-boiling components mixed in the charging liquid to the product column can be efficiently removed, 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 increased. The present disclosure has been completed based on these insights.

[0020] That is, the present disclosure provides a method for producing 1,3-butanediol, which is a method for producing purified 1,3-butanediol from a reaction crude liquid containing 1,3-butanediol, wherein,

[0021] the production method includes a dehydration step of removing water by distillation, a high-boiling component removal step of removing high-boiling components by distillation, and a product distillation step for obtaining purified 1,3-butanediol,

[0022] in the product column used in the product distillation step, a charging liquid containing 1,3-butanediol is distilled under the condition that the reflux ratio exceeds 0.1, a liquid in which low-boiling components are concentrated is distilled out from above the charging layer, and 1,3-butanediol is withdrawn from below the charging layer.

[0023] Alternatively, the reaction crude liquid containing 1,3-butanediol is a reaction crude liquid obtained by hydrogen reduction of aldol.

[0024] The production method may further include an alkali treatment step of treating a process stream containing 1,3-butanediol with an alkali.

[0025] The production method may further include a desalting step of removing salts from the process stream containing the 1,3-butanediol.

[0026] The production method may further include a de-alcoholization step of removing low-boiling components containing alcohol from the process stream containing the 1,3-butanediol.

[0027] Alternatively, the reflux ratio of the product column is 0.2 or more.

[0028] Alternatively, the concentration of 1,3-butanediol in the charging liquid to the product column is 90% or more.

[0029] Alternatively, the water content in the charging liquid to the product column is 3% by weight or less.

[0030] Alternatively, the content of low-boiling components other than water in the charging liquid to the product column is 1.8% or less.

[0031] Alternatively, the distillate rate in the product column may be set to less than 30% by weight.

[0032] The theoretical number of plates of the product column is, for example, 1 to 100 plates.

[0033] Alternatively, at least a part of the distillate of the product column may be recycled to the dehydration process, the dealcoholization process, the de-low-boiling process, or the process before these processes, which are the processes before the product distillation process.

[0034] Alternatively, the recycling amount of the distillate of the product column to the process before the product distillation process is within the range not exceeding the distillate amount in the product column, and is less than 30% by weight relative to the charging amount to the product column.

[0035] Alternatively, the recycling amount of the distillate of the product column to the process before the product distillation process is within the range not exceeding the distillate amount in the product column, and is 0.01% by weight or more relative to the charging amount to the product column.

[0036] The present disclosure also provides a 1,3-butanediol product having an initial boiling point higher than 203°C and a water content less than 0.4% by weight.

[0037] Alternatively, in the gas chromatography analysis under the following conditions, the area ratio of the peak of 1,3-butanediol in the 1,3-butanediol product is higher than 98.5%, and the total area ratio of the peaks having a retention time shorter than the peak of 1,3-butanediol is less than 0.3%.

[0038] (Conditions for gas chromatography analysis)

[0039] Analysis column: A column with a stationary phase of dimethylpolysiloxane (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0040] Temperature rising condition: Heat from 80°C to 120°C at 5°C / min, then heat to 160°C at 2°C / min and hold for 2 minutes. Further, heat to 230°C at 10°C / min and hold at 230°C for 18 minutes.

[0041] Sample introduction temperature: 250°C.

[0042] Carrier gas: Helium.

[0043] Gas flow rate of the column: 1 mL / min.

[0044] Detector and detection temperature: Flame ionization detector (FID), 280°C.

[0045] In addition, the present disclosure provides a humectant containing the above-mentioned 1,3-butanediol product.

[0046] In addition, the present disclosure also provides a cosmetic containing the moisturizer described above.

[0047] It should be noted that in the present disclosure, the "1,3 - butanediol product" refers to a composition in which 1,3 - butanediol accounts for the majority of the components (for example, the content of 1,3 - butanediol is 95% by weight or more, preferably 98% by weight or more).

[0048] Advantages of the Invention

[0049] According to the manufacturing method of the present disclosure, high - purity 1,3 - butanediol with a very low content of low - boiling components and a high initial boiling point can be manufactured with a high recovery rate.

[0050] In addition, the 1,3 - butanediol product of the present disclosure has a very low content of low - boiling components, a high initial boiling point, and is of high purity. Therefore, it is suitable for use as a moisturizer or as a raw material for cosmetics.

[0051] Furthermore, the moisturizer and the cosmetic of the present disclosure have excellent moisturizing performance and a very low content of low - boiling components, so they can maintain high quality for a long time. Brief Description of the Drawings

[0052] Figure 1 is a flowchart of a manufacturing method (purification method) of the 1,3 - butanediol product related to the present disclosure.

[0053] Figure 2 is a chromatogram of gas chromatography analysis of the 1,3 - butanediol product in Example 12.

[0054] Figure 3 is a chromatogram of gas chromatography analysis of the 1,3 - butanediol product in Comparative Example 2. Detailed Description of the Embodiments

[0055] [Manufacturing Method of 1,3 - Butanediol]

[0056] The manufacturing method of 1,3 - butanediol of the present disclosure is a manufacturing method of 1,3 - butanediol for obtaining purified 1,3 - butanediol from a reaction crude liquid containing 1,3 - butanediol (hereinafter sometimes referred to as "crude 1,3 - butanediol"). The manufacturing method has a dehydration step of removing water by distillation, a high - boiling component removal step of removing high - boiling components by distillation, and a product distillation step for obtaining purified 1,3 - butanediol. Moreover, in the product column used in the product distillation step, a charging liquid containing 1,3 - butanediol is distilled under the condition that the reflux ratio exceeds 0.1, a liquid in which low - boiling components are concentrated is distilled out from above the charging layer, and 1,3 - butanediol is withdrawn from below the charging layer. Since the content of low - boiling components in this 1,3 - butanediol is very low and the initial boiling point is high, a 1,3 - butanediol product can be produced.

[0057] [Crude 1,3 - butanediol]

[0058] As the crude 1,3 - butanediol, for example, the following can be cited: (1) a reaction crude liquid obtained by reduction (hydrogenation) of aldol compounds; (2) a reaction crude liquid obtained by hydrolysis of 1,3 - epoxybutane; (3) a reaction crude liquid obtained by selective hydrogenolysis of erythritol; (4) a reaction crude liquid obtained by selective hydro - addition of butadiene; (5) a reaction crude liquid obtained by hydrogenation of n - butyraldehyde - 3 - one; (6) a reaction crude liquid obtained by hydrogenation of 1 - butanol - 3 - one; (7) a reaction crude liquid obtained by hydrogenation of 3 - hydroxy - 1 - butyric acid; (8) a reaction crude liquid obtained by hydrogenation of β - butyrolactone; and (9) a reaction crude liquid obtained by hydrogenation of diketene. In the present disclosure, as the crude 1,3 - butanediol, it may be one or a mixture of two or more of the above (1) to (9). As the crude 1,3 - butanediol, preferably, it is the reaction crude liquid obtained by reduction (especially liquid - phase reduction) of aldol compounds as described in (1) above.

[0059] Hereinafter, mainly, the case where the reaction crude liquid obtained by reduction (hydrogenation) of aldol compounds is used as the crude 1,3 - butanediol will be described. It should be noted that the process of reducing (hydrogenating) aldol compounds is sometimes referred to as the "hydrogenation process".

[0060] The aldol compounds used as raw materials in the hydrogenation process are not particularly limited as long as they are compounds that can be hydrogen - reduced to 1,3 - butanediol. As the raw material aldol compounds, for example, aldol, dimeric metahydroxybutyraldehyde as its cyclic dimer, 2,6 - dimethyl - 1,3 - dioxane - 4 - ol as the cyclic trimer of acetaldehyde, and mixtures thereof can be cited.

[0061] The method for producing aldol compounds (such as aldol, dimeric metahydroxybutyraldehyde) is not particularly limited. 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 aldol compounds is sometimes referred to as the "aldol compound production process" or the "acetaldehyde polymerization process".

[0062] The reaction crude liquid containing aldol compounds obtained by the above reaction can be neutralized with an acid and used for the production of 1,3 - butanediol. In such a reaction crude liquid, in addition to aldol compounds, it may also contain acetaldehyde, crotonaldehyde, other aldehyde components, low - boiling substances, high - boiling substances such as aldehyde dimers or trimers, water, salts, etc. It should be noted that in this specification, a compound having a boiling point lower than that of 1,3 - butanediol is sometimes referred to as a "low - boiling substance" or "low - boiler", and a compound having a boiling point higher than that of 1,3 - butanediol is sometimes referred to as a "high - boiling substance" or "high - boiler".

[0063] The above-mentioned reaction crude liquid containing aldol can be pretreated as needed by implementing alcohol distillation, dehydration distillation, desalting, alkali treatment, dealkalization treatment, impurity removal, etc., to remove substances such as unreacted acetaldehyde and crotonaldehyde, which are by-products. As the pretreatment methods, distillation, adsorption, ion exchange, heating of high-boiling physical and chemical substances, decomposition, etc. can be cited. For distillation, various distillation methods such as vacuum distillation, atmospheric distillation, pressure distillation, azeotropic distillation, extraction distillation, and reactive distillation can be used. Particularly preferably, simple evaporation, distillation, and hydrogenation are implemented on the reaction crude liquid containing aldol to remove aldehydes such as acetaldehyde and crotonaldehyde, and then the hydrogenation process is implemented.

[0064] The content of aldol in the hydrogenation raw material is not particularly limited. For example, it is 30% by weight or more (for example, 30 - 99% by weight), more preferably 40% by weight or more (for example, 40 - 98% by weight), 50% by weight or more (for example, 50 - 97% by weight), or 60% by weight or more (for example, 60 - 95% by weight), further preferably 65 - 90% by weight, particularly preferably 70 - 90% by weight, and most preferably 75 - 90% by weight. By making the content of aldol within the above range, there is a tendency for the impurities contained in the reaction crude liquid (crude 1,3-butanediol) containing 1,3-butanediol to decrease.

[0065] The hydrogenation raw material may contain water or may not contain water, but from the perspective of the purity of the 1,3-butanediol product, it is preferably water-containing. The content of water in the hydrogenation raw material is not particularly limited. For example, it is 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 the upper limit value can 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 of 1,3-butanediol and aldol contained in the obtained crude 1,3-butanediol decreases, and thus there is a tendency for the purity of the finally obtained 1,3-butanediol product to be higher. The reason is that by containing a certain amount of water in the hydrogenation raw material, the above-mentioned acetal hydrolyzes to become 1,3-butanediol, and the co-existing aldol is reduced to become 1,3-butanediol.

[0066] As the hydrogenation catalyst, for example, Raney nickel etc. can be mentioned. The hydrogenation catalyst can be used in a suspended state or filled in a reaction vessel. 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 (partial pressure of hydrogen) in the reaction system is not particularly limited, for example, it is 7 to 60 MPa, preferably 10 to 30 MPa. The reaction temperature during the reduction reaction is not particularly limited, for example, it is 40 to 150 °C, preferably 50 to 140 °C, more preferably 60 to 130 °C. The reaction time (residence time) during the reduction reaction is not particularly limited, for example, it is 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. This reaction can be carried out in any of the batch form, semi-batch form, or continuous form.

[0067] 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, methyl vinyl ketone, their condensates, condensates of 1,3-butanediol and the above low-boiling substances (for example, acetal bodies of 1,3-butanediol and butanol aldehyde, etc.), alcohols such as ethanol, isopropanol, butanol, water (solvent, etc.), salts generated by neutralization treatment, etc., and the catalyst (in the case of being used in a suspended state). By removing these impurities in the purification process, a 1,3-butanediol product (purified 1,3-butanediol) can be obtained.

[0068] [Purification of Crude 1,3-Butanediol]

[0069] In the manufacturing method of the present disclosure, there is at least a dehydration step of removing water by distillation, a high-boiling component removal step (high-boiling substance distillation step) of removing high-boiling components by distillation, and a product distillation step for obtaining purified 1,3-butanediol. Both the dehydration step and the high-boiling component removal step are provided before the product distillation step, but the order of the dehydration step and the high-boiling component removal step is not limited. In the manufacturing method of the present disclosure, in addition to these steps, a desalting step, an alkali reaction step (alkali treatment step), and a dealkalization step may also be included. In addition, a catalyst separation step, a neutralization step using an alkali, and a de-alcoholization step (low-boiling component removal step) may be provided before the dehydration step. Each of the above steps may be carried out in the order described, and the order of each step may be appropriately changed except that the dealkalization step is provided after the alkali reaction step. For example, the de-alcoholization step (low-boiling component removal step), the desalting step, the alkali reaction step, and the dealkalization step may be provided at appropriate positions, 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 de-alcoholization step (low-boiling component removal step), the desalting step, the alkali reaction step, and the dealkalization step may be provided as needed and do not necessarily have to be provided.

[0070] Figure 1 It is a flowchart of an apparatus showing an example of an embodiment of the manufacturing method of 1,3-butanediol of the present disclosure. A is a dehydration tower, related to the dehydration step. B is a desalting tower, related to the desalting step. C is a high-boiling substance distillation tower (high-boiling tower), related to the high-boiling substance distillation step (high-boiling component removal step). D is an alkali reactor, related to the alkali reaction step. E is a dealkalization tower, related to the dealkalization step. F is a product distillation tower (product tower), related to the product distillation step. A-1, B-1, C-1, E-1, F-1 are condensers. A-2, C-2, F-2 are reboilers. Hereinafter, an example of an embodiment of the manufacturing method of 1,3-butanediol of the present disclosure will be described using this flowchart.

[0071] The crude 1,3-butanediol obtained by hydrogen reduction of the hydrogenation raw material (equivalent to "X-1") is supplied to the dehydration tower A. In the dehydration tower A, water is distilled off from the top of the tower, 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 above crude 1,3-butanediol (equivalent to "X-1") may be supplied to the dehydration tower A after passing through a de-alcoholization step (distillation step using a de-alcoholization tower) for removing alcohols such as ethanol and low-boiling components.

[0072] Supply the above-mentioned crude 1,3-butanediol stream to the desalting tower B. In the desalting tower B, the desalted crude 1,3-butanediol stream is obtained from the top of the tower by distillation, and salts, high-boiling substances, etc. are discharged from the bottom of the tower as residual liquid. The residual rate (%) of the desalting tower B [(amount of desalting tower residue (parts) / amount of desalting tower feed (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 part of the residual liquid of the desalting tower can also be recycled to the process before the desalting process.

[0073] Supply the above-mentioned desalted crude 1,3-butanediol stream to the high-boiling component removal tower C. In the high-boiling component removal tower C, high-boiling components (high-boiling substances) are discharged from below the charging layer (preferably from the bottom of the tower). On the other hand, a crude 1,3-butanediol stream (1,3-butanediol with further improved purity) after removing high-boiling substances is obtained from above the charging layer.

[0074] As the high-boiling component removal tower C, for example, a perforated plate tower, a bubble cap 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.) is more preferred. The reason is that 1,3-butanediol and trace impurities thermally decompose at high temperatures (for example, 150 °C or higher) to generate low-boiling substances as coloring components, so the distillation temperature is reduced. In addition, the same effect occurs when the thermal process (residence time) of 1,3-butanediol is long. Therefore, the reboiler adopted is preferably one with a shorter residence time of the process-side fluid. For example, natural falling film evaporators, forced agitation type thin film evaporators, etc. are preferred.

[0075] Regarding the number of trays of the high-boiling component removal tower C, the theoretical number of trays is, for example, 1 to 100 trays, preferably 2 to 90 trays, more preferably 3 to 80 trays, further preferably 4 to 70 trays, 5 to 60 trays, 8 to 50 trays or 10 to 40 trays, and particularly preferably 15 to 30 trays. The supply position of the charging liquid is from the top of the high-boiling component removal tower downward, at a position of, for example, 10% to 90% of the height of the tower, preferably 20% to 80%, more preferably 30 to 70 trays, and further preferably 40% to 60%. In the distillation in the high-boiling component removal tower C, the pressure at the top of the tower (absolute pressure) 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.

[0076] The reflux ratio in the high-boiling-point removal column C [reflux amount in the high-boiling-point removal column / distillate amount in the high-boiling-point removal column (discharge amount to the outside of the distillation column)] 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 aspect of energy cost, the upper limit of the reflux ratio is, for example, 100, preferably 50.

[0077] The crude 1,3-butanediol stream withdrawn from above the charging layer of the high-boiling-point removal column C is supplied to an alkali reactor (e.g., a flow-through tubular reactor) D for alkali treatment. By the alkali treatment, by-products contained in the crude 1,3-butanediol can be decomposed. An alkali is added to the alkali reactor D or a pipe upstream thereof. The addition amount of the alkali is, for example, 0.05 to 10% by weight, preferably 0.1 to 1.0% by weight, based on the crude 1,3-butanediol stream subjected to the alkali treatment. If the addition amount of the alkali exceeds 10% by weight, the alkali may precipitate in the distillation column, pipe, etc., causing blockage. In addition, sometimes the decomposition reaction of high-boiling compounds may occur, generating by-products instead. When the addition amount of the alkali is less than 0.05% by weight, the effect of decomposing by-products is small.

[0078] The alkali added to the alkali reactor D or a pipe upstream thereof is not particularly limited. For example, an alkali metal compound is preferably used. Examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, sodium (hydrogen) carbonate, and potassium (hydrogen) carbonate. In addition, as the alkali, an alkaline ion exchange resin can also be used. From the viewpoint of reducing by-products contained in the finally obtained 1,3-butanediol product, sodium hydroxide and potassium hydroxide are preferably used as the alkali. The alkali can be added directly as a solid substance, but for operational reasons and to promote contact with the liquid to be treated, it is preferably added as an aqueous solution. It should be noted that the above-mentioned alkali can be used alone or two or more kinds can be used simultaneously.

[0079] The reaction temperature in the alkali reactor D is not particularly limited, but for example, it is preferably 90°C to 140°C, more preferably 110°C to 130°C. 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 finally obtained 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 finally obtained 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 the viewpoint of economy.

[0080] After leaving the alkali reactor D, the reaction crude liquid stream is supplied to a dealkalization tower (e.g., a thin-film evaporator) E as needed, and alkalis 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, a natural falling-film evaporator with a short residence time or a forced stirring type thin-film evaporator is suitable as the evaporator for the dealkalization tower E. It should be noted that an air purifier may be provided in the space above the charging position of the dealkalization tower (e.g., a thin-film evaporator) E to remove alkalis and droplets. Thereby, it is possible to prevent alkalis and high-boiling substances from being mixed into the 1,3-butanediol product.

[0081] In the evaporator for the dealkalization tower E, for example, evaporation is carried out under a reduced pressure with an absolute pressure of 20 kPa or less at the top of the tower, preferably an absolute pressure of 0.5 to 10 kPa. The temperature of the evaporator is, for example, preferably 90°C to 120°C. The crude 1,3-butanediol stream containing low-boiling substances distilled from the top of the tower is supplied to a product distillation tower (product tower) F.

[0082] It should be noted that the alkali reactor D and the dealkalization tower E can be provided between the desalting tower B and the dehigh-boiling tower C, between the dehydration tower A and the desalting tower B (in this case, the desalting 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 may not be provided, and alkali treatment may be carried out by charging alkali into the dehigh-boiling tower charging pipeline, or into the dehydration tower charging pipeline, or adding it to the hydrogenated reaction liquid [and then charging it into a de-alcohol tower (de-low-boiling tower)].

[0083] In the manufacturing method of the present disclosure, in the product tower F used in the product distillation step, the charging liquid containing 1,3-butanediol is distilled under the condition that the reflux ratio is greater than 0.1, and a liquid in which low-boiling components are concentrated is distilled out from above the charging layer (corresponding to Figure 1 "X-6"), and 1,3-butanediol is drawn out from below the charging layer (corresponding to Figure 1The content of the low-boiling components of 1,3-butanediol is extremely small and the initial boiling point is high, so it can be directly made into 1,3-butanediol products.

[0084] As the product distillation column F, for example, a perforated plate column, a bubble cap column, etc. can be used, but a packed column with low pressure loss filled with Sulzer Packings, Mellapak (both are trade names of Sumitomo Heavy Industries, Ltd.) etc. is more preferred. The reason is that 1,3-butanediol and the impurities contained in trace amounts thermally decompose at high temperatures (for example, 150 °C or higher) to generate low-boiling substances as coloring components, so the distillation temperature is reduced. In addition, the same effect occurs when the thermal process (residence time) of 1,3-butanediol is long. Therefore, the reboiler adopted 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 or a forced stirring type thin-film evaporator is preferred.

[0085] The theoretical number of trays of the product column F is, for example, 1 to 100 trays, preferably 2 to 90 trays, 3 to 80 trays, 4 to 70 trays, 5 to 60 trays, 8 to 50 trays or 10 to 40 trays, and more preferably 15 to 30 trays. The supply position of the feed liquid is, from the top of the column downward, at a position of, for example, 10% to 90% of the height of the column, preferably 20% to 80%, more preferably 30% to 70%, and further preferably 40% to 60%. 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 further preferably 0.5 to 5 kPa.

[0086] In Figure 1 regard to the feed to the product column F, the liquid obtained by condensing the overhead vapor of the dealkalization column E using the condenser E-1 is fed, or the overhead vapor from the dealkalization column E can also be directly fed to the product column F.

[0087] The concentration of 1,3-butanediol in the charging liquid 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 charging liquid to the product column F can be increased, for example, by adjusting the distillation conditions of the dehydration column A, or by providing a de-alcoholization column (low-boiling component removal column) before the dehydration column A and adjusting its distillation conditions, or by adjusting the distillation conditions of the high-boiling component removal column C. For example, by increasing the reflux ratio of the de-alcoholization column (low-boiling component removal column), the dehydration column A, and / or the high-boiling component removal column C, or by increasing the number of trays, the purity of 1,3-butanediol in the charging liquid to the product column F can be increased. It should be noted that the above concentration of 1,3-butanediol is the ratio (area %) of the peak area of 1,3-butanediol to the total peak area in the gas chromatography analysis under the following conditions.

[0088] (Conditions for gas chromatography analysis)

[0089] Analysis column: A column with a stationary phase of dimethylpolysiloxane (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0090] Temperature rising conditions: Heat from 80°C to 120°C at 5°C / min, then heat to 160°C at 2°C / min and hold for 2 minutes. Further, heat to 230°C at 10°C / min and hold at 230°C for 18 minutes.

[0091] Sample introduction temperature: 250°C.

[0092] Carrier gas: Helium.

[0093] Gas flow rate of the column: 1 mL / min.

[0094] Detector and detection temperature: Flame ionization detector (FID), 280°C.

[0095] In the manufacturing method of the present disclosure, the water content in the charging liquid of the product column F is, for example, 3% by weight or less, preferably 2.8% by weight or less, more preferably 2.6% by weight or less, 2.4% by weight or less, 2.2% by weight or less, 2% by weight or less, 1.8% by weight or less, 1.6% by weight or less, 1.4% by weight or less, 1.4% by weight or less, 1.2% by weight or less, 1% by weight or less, 0.95% by weight or less, 0.9% by weight or less, 0.8% by weight or less, 0.7% by weight or less, 0.6% by weight or less, 0.5% by weight or less, 0.4% by weight or less, 0.3% by weight or less, or 0.2% by weight or less, and particularly preferably 0.1% by weight or less. The water content in the charging liquid of 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 trays, and the distillate rate of the dehydration column A, the water concentration in the charging liquid of the product column F can be reduced. It should be noted that the water content in the charging liquid of the product column F can be quantified using a Karl-Fischer moisture meter.

[0096] The content of low-boiling components (excluding water) in the charging liquid of the product column 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 components (also referred to as "low boilers") other than water in the charging liquid of the product column F is the ratio (area%) of the total peak area of the peaks with a retention time shorter 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 components (excluding water) in the charging liquid of the product column F can be reduced, for example, by providing a de-alcoholization column (low-boiling removal column) upstream of the product column F and adjusting the distillation conditions of the de-alcoholization column (low-boiling removal column). For example, by increasing the reflux ratio, the number of trays, and the distillate rate of the de-alcoholization column (low-boiling removal column), the concentration of low-boiling components (excluding water) in the charging liquid of the product column F can be reduced.

[0097] In the manufacturing method of the present disclosure, the reflux ratio in the product column F [product column reflux amount / product column distillate amount (discharge amount outside the distillation column)] 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).

[0098] In the production method of the present disclosure, by setting the reflux ratio in the product column F within the above-specified range, high-purity 1,3-butanediol with a very low content of low-boiling components and a high initial boiling point can be produced with a high recovery rate.

[0099] In the production method of the present disclosure, from the perspective of improving the recovery rate of 1,3-butanediol, the distillate 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, and still more 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 distillate rate refers to the ratio (% by weight) of the amount of the liquid withdrawn from above the charging layer (e.g., the top of the column) of the product column F to the outside of the distillation column (including the recycled amount in the case of recycling to the previous process described later) to the charging amount to the product column F.

[0100] At least a part of the liquid in which the low-boiling components withdrawn from above the charging layer of the product column F are concentrated (hereinafter sometimes referred to as "distillate") may also be recycled to the process before the product distillation process ( Figure 1 the dotted arrow shown on the right side of the product column F). By recycling at least a part of the above distillate to the process before the product distillation process, the recovery rate of 1,3-butanediol can be improved.

[0101] Examples of the process before the above product distillation process include a dehydration process, a de-alcoholization process (low-boiling component removal process), etc. It should be noted that the de-alcoholization process (low-boiling component removal process) is preferably provided before the dehydration process.

[0102] The recycling amount of the above distillate in 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 above distillate in the process before the product distillation process is, for example, less than 30% by weight relative to the charging amount to the product tower F. In addition, from the viewpoints of improving the recovery rate of 1,3BG in the product tower and the yield of the entire process, the recycling amount of the above distillate in 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 relative to the charging amount to the product tower F, and particularly preferably 20% by weight or more.

[0103] Thus, according to the manufacturing method of the present disclosure, high-purity 1,3-butanediol with a very low content of low-boiling components and a high initial boiling point can be manufactured with a high recovery rate. It should be noted that in this specification, the recovery rate of 1,3BG in the product tower F is the value (%) obtained by the following formula.

[0104] {1 - [GC area% of 1,3BG in the distillate × (distillate amount (parts) - recycling amount (parts))] / (GC area% of 1,3BG in the charged liquid × charged amount (parts))} × 100 It should be noted that low-boiling substances and high-boiling substances may sometimes be hydrolyzed by water to generate 1,3BG. On the other hand, high-boiling substances may sometimes be generated by the polymerization of 1,3BG, and furthermore, trace impurities may be generated or disappear. Therefore, the material balance in the product tower may not always be achieved. This also applies to other distillation towers such as a de-alcoholization tower (low-boiling tower), a dehydration tower, and a high-boiling tower.

[0105] [1,3-Butanediol Product]

[0106] The 1,3-butanediol product of the present disclosure can be obtained by the above manufacturing method of the present disclosure. The initial boiling point of the 1,3-butanediol product of the present disclosure is higher than 203 °C and the water content is less than 0.4% by weight. The initial boiling point is preferably 204 °C or higher, more preferably 205 °C or higher, further preferably 206 °C or higher, or 207 °C, and particularly preferably 208 °C or higher. The water content is preferably 0.3% by weight or less, more preferably 0.2% by weight or less, further preferably 0.1% by weight or less, 0.07% by weight or less, 0.05% by weight or less, 0.03% by weight or less, 0.02% by weight or less, or 0.01% by weight or less, and particularly preferably 0.005% by weight or less. It should be noted that the water content can be quantified using a Karl Fischer moisture analyzer.

[0107] In addition, preferably, in the 1,3-butanediol product of the present disclosure, in the gas chromatography analysis (GC analysis) under the following conditions, the area ratio of the peak of 1,3-butanediol is higher than 98.5%, and the total area ratio of the peaks with a retention time shorter than that of the peak of 1,3-butanediol is lower than 0.3%.

[0108] (Conditions for gas chromatography analysis)

[0109] Analysis column: A column with a stationary phase of dimethyl polysiloxane (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0110] Temperature rising conditions: Heat from 80°C to 120°C at 5°C / minute, then heat to 160°C at 2°C / minute and hold for 2 minutes. Further, heat to 230°C at 10°C / minute and hold at 230°C for 18 minutes.

[0111] Sample introduction temperature: 250°C.

[0112] Carrier gas: Helium.

[0113] Gas flow rate of the column: 1 mL / minute.

[0114] Detector and detection temperature: Flame ionization detector (FID), 280°C.

[0115] The area ratio of the peak of the above-mentioned 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.

[0116] The total area ratio of the peaks with a retention time shorter than that of the peak of the 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 (for example, 0.002% or less).

[0117] 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 the chromatogram to the sum of the areas of all peaks. In addition, all peaks refer to, for example, all the 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.

[0118] By making the area ratio of the peak of the above-mentioned 1,3-butanediol and the total area ratio of the peaks with retention times shorter than that of the peak of the 1,3-butanediol fall within the above ranges, a high-purity and high-quality 1,3-butanediol product can be provided.

[0119] [Humectant and Cosmetic]

[0120] The humectant of the present disclosure contains the above-mentioned 1,3-butanediol product. Therefore, it has excellent moisture retention performance. The humectant of the present disclosure may also contain components other than the above-mentioned 1,3-butanediol product, for example, humectant components other than the above-mentioned 1,3-butanediol product, etc. In the humectant of the present disclosure, 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 consist only of the above-mentioned 1,3-butanediol product.

[0121] The cosmetic of the present disclosure contains the above-mentioned humectant. Depending on the type and form of the cosmetic, the blending amount of the above-mentioned 1,3-butanediol product in the cosmetic of the present disclosure may be any amount that can exhibit moisture retention performance. The blending amount of the above-mentioned 1,3-butanediol product in the cosmetic of the present disclosure 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, particularly preferably 1 to 10% by weight.

[0122] In addition to the above-mentioned 1,3-butanediol product, the cosmetic of the present disclosure may also contain, for example: other humectants; oil agents 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 blockers, fragrances, pH regulators; medicinal components and physiologically active components such as vitamin agents, skin activators, blood circulation promoters, whitening agents, antibacterial agents, and anti-inflammatory agents.

[0123] The cosmetic of the present disclosure can be made into: skin cosmetics such as lotion, emulsion, cream, gel, mask pack, mask, etc.; hair cosmetics such as shampoo, conditioner, hair growth agent, etc. In addition, it can also be made into sunscreen cosmetics, color cosmetics, etc. In addition, it can also be made into pharmaceuticals and quasi-drugs containing medical components.

[0124] The cosmetic of the present disclosure can be manufactured by using a method known per se.

[0125] It should be noted that the various solutions disclosed in this specification can be combined with any other features disclosed in this specification. In addition, each component and the combination of components in each embodiment are examples, and additional components, omissions, and other changes can be appropriately made within the scope of not departing from the gist of the present disclosure. The present disclosure is not limited by the embodiments, but only by the claims.

[0126] Example

[0127] 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 "parts" used in the examples refer to "parts by weight" unless otherwise specified. Gas chromatography analysis (GC analysis), determination of the initial boiling point, and determination of moisture are carried out by the methods described below.

[0128] [Example 1]

[0129] Use Figure 1 To illustrate the manufacturing method of 1,3 - butanediol.

[0130] Relative to 100 parts of a butyraldehyde solution containing 30% by weight of water as a raw material (a mixed solution of 69 parts of butyraldehyde and 29 parts of water, containing a total of 2 parts of low - boiling and high - boiling impurities and less than 0.1 part of Na salt), 10 parts of hydrogen was charged into a liquid - phase hydrogen reduction reactor, 15 parts of Raney nickel as a catalyst was added, and the reactor was maintained at 120 °C and 10 MPa (gauge pressure) for liquid - phase hydrogen reduction. After separating the catalyst from the reaction liquid, it was neutralized with caustic soda to obtain crude 1,3 - butanediol (1) containing low - boiling impurities and water.

[0131] It should be noted that the butyraldehyde solution containing 30% by weight of water used as a raw material is produced by dimerizing acetaldehyde by stirring acetaldehyde and water at 30 °C for 10 hours in the presence of 100 ppm by weight of NaOH [acetaldehyde polymerization process (aldol condensation process of acetaldehyde)].

[0132] The crude 1,3 - butanediol (1) (corresponding to Figure 1 "X - 1" therein) was charged into dehydration tower A. In dehydration tower A, relative to 100 parts of the feed liquid volume, water was withdrawn from the top of the tower, 15 parts of fresh water was added as reflux water, the top - tower pressure was set to 7 kPa (absolute pressure), and crude 1,3 - butanediol (2) with 1% by weight of water and a total area ratio of impurity peaks with a retention time (RT) shorter than that of 1,3 - butanediol in the subsequent GC analysis of 1.8% was obtained from the bottom of the tower. It should be noted that the water withdrawn from the top of the tower was discharged (corresponding to Figure 1 "X - 2" therein).

[0133] Next, crude 1,3-butanediol (2) was charged into desalting column B. In desalting column B, salts, high-boiling substances, and a part of 1,3-butanediol were discharged as evaporation residues from the bottom of the column (corresponding to Figure 1 "X-3" in

[0134] ). The discharge amount of the evaporation residues was 5 parts with respect to 100 parts of the charged liquid. On the other hand, crude 1,3-butanediol (3) containing 1,3-butanediol, low-boiling substances, and a part of high-boiling substances was obtained from the top of the column. Next, crude 1,3-butanediol (3) was charged into high-boiling substance removal column C. In high-boiling substance removal column C, distillation was carried out under the condition of a top pressure of 5 kPa (absolute pressure), and high-boiling substances and a part of 1,3-butanediol were discharged from the bottom of the column (corresponding to Figure 1 "X-4" in

[0135] ). The bottom discharge amount was 20 parts with respect to 100 parts of the charged liquid. On the other hand, 80 parts of crude 1,3-butanediol (4) containing low-boiling substances was obtained as a distillate from the top of the column. Next, crude 1,3-butanediol (4) was charged into alkali reactor D. At this time, a 20 wt% aqueous sodium hydroxide solution was added so that the concentration of caustic soda with respect to the charged liquid became 0.1 wt%. The reaction temperature in alkali reactor D was maintained at 120 °C, and the reaction was carried out with a residence time of 20 minutes.

[0136] Next, the reaction crude liquid leaving alkali reactor D was charged into alkali removal column E. In alkali removal column E, caustic soda, high-boiling substances, and a part of 1,3-butanediol were discharged from the bottom of the column (corresponding to Figure 1 "X-5" in

[0137] ). The bottom discharge amount was 5 parts with respect to 100 parts of the charged liquid. On the other hand, 95 parts of crude 1,3-butanediol (5) containing 1,3-butanediol and low-boiling substances was obtained from the top of the column. The moisture content and GC analysis of crude 1,3-butanediol (5) containing 1,3-butanediol and low-boiling substances were carried out. As a result, the moisture concentration was 1.2 wt%, the area ratio of 1,3-butanediol was 97%, and the total area ratio of impurity peaks with a retention time shorter than that of 1,3-butanediol was 1.8%. Next, crude 1,3-butanediol (5) was charged into product distillation column F. In product distillation column F, with respect to 100 parts of the charged liquid, 10 parts of low-boiling substances and a part of 1,3-butanediol were distilled out from the top of the column (corresponding to Figure 1 "X-6" in Figure 1 ), and the whole amount was discharged out of the system. The operation was carried out at a reflux ratio (reflux amount / distillate amount) of 0.3 at this time, and 90 parts of 1,3-butanediol product (distillation rate 10 wt%) was obtained from the bottom of the column (corresponding to "Y" in

[0138] ).The obtained 1,3 - butanediol product was subjected to the determination of the initial boiling point, the determination of moisture content, and GC analysis. As a result, the initial boiling point was 203.3 °C, the moisture concentration was 0.2 wt%, the area ratio of 1,3 - butanediol was 98.6%, and the total area ratio of impurity peaks with a retention time shorter than that of 1,3 - butanediol was 0.2% (retention time of 1,3 - butanediol: 6.5 minutes). The recovery rate of 1,3 - butanediol in the product column F was 92%.

[0139] [Example 2]

[0140] The reflux ratio of the product column F was changed to 1, and in other respects, 93 parts of 1,3 - butanediol product were obtained from the bottom of the product column F by the same method as in Example 1. The obtained 1,3 - butanediol product was subjected to the determination of the initial boiling point, the determination of moisture content, and GC analysis. As a result, the initial boiling point was 206.8 °C, the moisture concentration was 0.1 wt%, the area ratio of 1,3 - butanediol was 98.7%, and the total area ratio of impurity peaks with a retention time shorter than that of 1,3 - butanediol was 0.09%. The recovery rate of 1,3 - butanediol in the product column F was 92%.

[0141] [Example 3]

[0142] The reflux ratio of the product column F was set to 1, and the distillate of the product column F was withdrawn out of the system and all of it was recycled to the feed pipeline of the dehydration column A. In other respects, 90 parts of 1,3 - butanediol product (distillation rate 10 wt%) were obtained from the bottom of the product column F by the same method as in Example 1. The obtained 1,3 - butanediol product was subjected to the determination of the initial boiling point, the determination of moisture content, and GC analysis. As a result, the initial boiling point was 206.7 °C, the moisture concentration was 0.1 wt%, the area ratio of 1,3 - butanediol was 98.7%, and the total area ratio of impurity peaks with a retention time shorter than that of 1,3 - butanediol was 0.09%. The recovery rate of 1,3 - butanediol in the product column F was over 99%.

[0143] [Example 4]

[0144] The reflux ratio of the product column F was set to 10, and in other respects, 90 parts of 1,3 - butanediol product were obtained from the bottom of the product column F by the same method as in Example 3. The obtained 1,3 - butanediol product was subjected to the determination of the initial boiling point, the determination of moisture content, and GC analysis. As a result, the initial boiling point was 208.2 °C, the moisture concentration was 0.01 wt%, the area ratio of 1,3 - butanediol was 98.8%, and the total area ratio of impurity peaks with a retention time shorter than that of 1,3 - butanediol was 0.03%. The recovery rate of 1,3 - butanediol in the product column F was over 99%.

[0145] [Example 5]

[0146] The reflux ratio of the product column F was set to 20, and in other respects, 90 parts of 1,3 - butanediol product were obtained from the bottom of the product column F by the same method as in Example 3. The obtained 1,3 - butanediol product was subjected to the measurement of the initial boiling point, the measurement of water content, and GC analysis. As a result, the initial boiling point was 208.3 °C, the water concentration was 0.008 wt%, the area ratio of 1,3 - butanediol was 98.8%, and the total area ratio of impurity peaks with retention times shorter than that of 1,3 - butanediol was 0.009%. The recovery rate of 1,3 - butanediol in the product column F was 99% or more.

[0147] [Example 6]

[0148] The reflux ratio of the product column F was set to 50, and in other respects, 90 parts of 1,3 - butanediol product were obtained from the bottom of the product column F by the same method as in Example 3. The obtained 1,3 - butanediol product was subjected to the measurement of the initial boiling point, the measurement of water content, and GC analysis. As a result, the initial boiling point was 208.3 °C, the water concentration was 0.006 wt%, the area ratio of 1,3 - butanediol was 98.8%, and the total area ratio of impurity peaks with retention times shorter than that of 1,3 - butanediol was 0.007%. The recovery rate of 1,3 - butanediol in the product column F was 99% or more.

[0149] [Example 7]

[0150] As the charging liquid to the product column F, a liquid with a water concentration of 0.4 wt%, an area ratio of 1,3 - butanediol of 98%, and a total area ratio of impurity peaks with retention times shorter than that of 1,3 - butanediol of 0.7% was used, and the reflux ratio of the product column F was set to 1. 99 parts (distillation rate 1 wt%) of 1,3 - butanediol product were obtained from the bottom of the product column F, and in other respects, the same operations as in Example 3 were carried out. The obtained 1,3 - butanediol product was subjected to the measurement of the initial boiling point, the measurement of water content, and GC analysis. As a result, 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 retention times shorter than that of 1,3 - butanediol was 0.07%. The recovery rate of 1,3 - butanediol in the product column F was 99% or more.

[0151] [Example 8]

[0152] The reflux ratio of the product column F was set to 5, and in other respects, the same operations as in Example 7 were carried out. The obtained 1,3 - butanediol product was subjected to the measurement of the initial boiling point, the measurement of water content, and GC analysis. As a result, the initial boiling point was 208.3 °C, the water concentration was 0.008 wt%, the area ratio of 1,3 - butanediol was 98.7%, and the total area ratio of impurity peaks with retention times shorter than that of 1,3 - butanediol was 0.009%. The recovery rate of 1,3 - butanediol in the product column F was 99% or more.

[0153] [Example 9]

[0154] The reflux ratio of the product column F was set to 10, and otherwise, the same operations as in Example 7 were carried out. The initial boiling point, water content, and GC analysis of the obtained 1,3-butanediol product were performed. As a result, the initial boiling point was 208.3 °C, the water concentration was 0.006 wt%, the area ratio of 1,3-butanediol was 98.7%, and the total area ratio of impurity peaks with retention times shorter than that of 1,3-butanediol was 0.007%. The recovery rate of 1,3-butanediol in the product column F was over 99%.

[0155] [Example 10]

[0156] The reflux ratio of the product column F was set to 100, and otherwise, the same operations as in Example 7 were carried out. The initial boiling point, water content, and GC analysis of the obtained 1,3-butanediol product were performed. As a result, the initial boiling point was 208.3 °C, the water concentration was 0.005 wt%, the area ratio of 1,3-butanediol was 98.7%, and the total area ratio of impurity peaks with retention times shorter than that of 1,3-butanediol was 0.005%. The recovery rate of 1,3-butanediol in the product column F was over 99%.

[0157] [Example 11]

[0158] The reflux ratio of the product column F was set to 500, and otherwise, the same operations as in Example 7 were carried out. The initial boiling point, water content, and GC analysis of the obtained 1,3-butanediol product were performed. As a result, the initial boiling point was 208.4 °C, the water concentration was 0.004 wt%, the area ratio of 1,3-butanediol was 98.7%, and the total area ratio of impurity peaks with retention times shorter than that of 1,3-butanediol was 0.004%. The recovery rate of 1,3-butanediol in the product column F was over 99%.

[0159] [Example 12]

[0160] As the charging liquid to the product column F, a liquid with a water concentration of 0.1 wt%, an area ratio of 1,3-butanediol of 99%, and a total area ratio of impurity peaks with retention times shorter than that of 1,3-butanediol of 0.6% was used, and the reflux ratio of the product column F was set to 10. 99.7 parts (distillation rate 0.3 wt%) of 1,3-butanediol product were obtained from the bottom of the product column F. Otherwise, the same operations as in Example 3 were carried out. The initial boiling point, water content, and GC analysis of the obtained 1,3-butanediol product were performed. As a result, the initial boiling point was 208.2 °C, the water concentration was 0.01 wt%, the area ratio of 1,3-butanediol was 99.5%, and the total area ratio of impurity peaks with retention times shorter than that of 1,3-butanediol was 0.1%. The recovery rate of 1,3-butanediol in the product column F was over 99%.

[0161] [Example 13]

[0162] As the charging liquid to the product column F, a liquid with a water concentration of 3% by weight, an area ratio of 1,3-butanediol of 99%, and a total area ratio of impurity peaks with a retention time shorter than that of 1,3-butanediol of 0.8% was used. The reflux ratio of the product column F was set to 10, and 90 parts of 1,3-butanediol product (distillation rate 10% by weight) were obtained from the bottom of the product column F. Except for this, the same operations as in Example 3 were carried out. The initial boiling point, water content, and GC analysis of the obtained 1,3-butanediol product were measured. As a result, the initial boiling point was 206.7 °C, the water concentration was 0.1% by weight, the area ratio of 1,3-butanediol was 99.4%, and the total area ratio of impurity peaks with a retention time shorter than that of 1,3-butanediol was 0.02%. The recovery rate of 1,3-butanediol in the product column F was 99% or more.

[0163] [Comparative Example 1]

[0164] The reflux ratio of the product column F was set to 0.05, and 80 parts of 1,3-butanediol product (distillation rate 20% by weight) were obtained from the bottom of the product column F. Except for this, the same operations as in Example 1 were carried out. The initial boiling point, water content, and GC analysis of the obtained 1,3-butanediol product were measured. As a result, the initial boiling point was 194.6 °C, the water concentration was 0.6% by weight, the area ratio of 1,3-butanediol was 98.5%, and the total area ratio of impurity peaks with a retention time shorter than that of 1,3-butanediol was 0.3%. The recovery rate of 1,3-butanediol in the product column F was 82%.

[0165] [Comparative Example 2]

[0166] The reflux ratio of the product column F was set to 0.1, and 80 parts of 1,3-butanediol product (distillation rate 20% by weight) were obtained from the bottom of the product column F. Except for this, the same operations as in Example 1 were carried out. The initial boiling point, water content, and GC analysis of the obtained 1,3-butanediol product were measured. As a result, the initial boiling point was 199.0 °C, the water concentration was 0.4% by weight, the area ratio of 1,3-butanediol was 98.6%, and the total area ratio of impurity peaks with a retention time shorter than that of 1,3-butanediol was 0.2%. The recovery rate of 1,3-butanediol in the product column F was 82%.

[0167] [Reference Example 1]

[0168] The reflux ratio of the product column F was set to 0.1, and 70 parts of 1,3-butanediol product (distillation rate: 30% by weight) was obtained from the bottom of the product column F. Other than this, the same operations as in Example 1 were carried out. The initial boiling point, water content, and GC analysis of the obtained 1,3-butanediol product were performed. As a result, the initial boiling point was 203.1 °C, the water concentration was 0.2% by weight, the area ratio of 1,3-butanediol was 98.7%, and the total area ratio of impurity peaks with retention times shorter than that of 1,3-butanediol was 0.1%. The recovery rate of 1,3-butanediol in the product column F was 72%.

[0169] [Gas Chromatography Analysis]

[0170] Gas chromatography analysis of the 1,3-butanediol product as the object was carried out under the following conditions. The chromatogram of the gas chromatography analysis of the 1,3-butanediol product in Example 12 is shown in Figure 2 . In addition, the chromatogram of the gas chromatography analysis of the 1,3-butanediol product in Comparative Example 2 is shown in Figure 3 .

[0171] (Conditions for Gas Chromatography Analysis)

[0172] Analysis device: Shimadzu GC2010.

[0173] Analysis column: A column with a stationary phase of dimethylpolysiloxane (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.).

[0174] Temperature rising conditions: Heat from 80 °C to 120 °C at 5 °C / min, then heat to 160 °C at 2 °C / min and hold for 2 minutes. Further, heat to 230 °C at 10 °C / min and hold at 230 °C for 18 minutes.

[0175] Sample introduction and temperature: Split sample introduction method, 250 °C.

[0176] Split gas flow rate and carrier gas: 23 mL / min, helium.

[0177] Column gas flow rate and carrier gas: 1 mL / min, helium.

[0178] Detector and temperature: Flame ionization detector (FID), 280 °C.

[0179] Injected sample: 0.2 μL of an 80% by weight aqueous solution of 1,3-butanediol product.

[0180] [Measurement of Initial Boiling Point]

[0181] It is carried out according to the test method specified in the atmospheric distillation test method of JIS K2254 "Petroleum products - Test method for distillation".

[0182] [Determination of moisture]

[0183] It is carried out using a Karl Fischer moisture determination apparatus.

[0184] [Investigation of results]

[0185] The results of the above comparative examples, reference examples and examples are shown in Tables 1 and 2.

[0186] [Table 1]

[0187]

[0188] [Table 2]

[0189]

[0190]

[0191] According to Comparative Examples 1 and 2, when the distillate rate is 20% by weight, even if the reflux ratio is 0.1, the removal effect of water and low-boiling impurities is low, and the initial boiling point of the product will not become a satisfactory value. In Reference Example 1, when the distillate rate is 30% by weight, although the reflux ratio is 0.1 and the initial boiling point of the product can be satisfied, the recovery rate of 1,3BG in the product column deteriorates to 72%, so it is economically disadvantageous.

[0192] According to Comparative Examples 1-2, Reference Example 1 and Example 1, when the reflux ratio of the product column is changed from 0.1 to 0.3, the distillate rate is 10% by weight (recovery rate 92%), and the removal amount of moisture and low-boiling components from the distillate of the product column increases. Therefore, the concentrations of moisture and low-boiling components in the product decrease. As a result, the initial boiling point of the residual liquid (product) in the product column increases. It can be seen that if the feed composition (especially water, or water and low-boiling components) is controlled and the reflux ratio and distillate amount are controlled, even at a relatively low reflux ratio, the quality can be maintained with a certain degree of recovery rate.

[0193] According to Examples 1 and 2, when the reflux ratio of the product column is changed from 0.3 to 1, the removal amount of moisture and low-boiling components from the distillate of the product column increases. Therefore, the concentrations of moisture and low-boiling components in the product decrease. As a result, the initial boiling point of the residual liquid (product) increases.

[0194] When comparing Example 2 and Example 3, by recycling the distillate of the product column, when the recovery rate of 1,3BG is increased, substantially the same product quality is obtained. The reason is that almost all of the water and low-boiling impurities contained in the distillate of the product column are removed by distillation in the dehydration column.

[0195] According to Embodiments 3 to 6, when the reflux ratio is increased, the moisture content and the concentration of low-boiling components of the product are further reduced, and the initial boiling point is increased.

[0196] According to Embodiments 2 and 7, if the purity of the product charge is increased and the moisture content and the concentration of low-boiling components are reduced, the product quality is the same or improved even if the distillate amount is reduced. Further, according to Embodiments 7 to 11, if the reflux ratio is increased, the product quality is improved. However, if the reflux ratio is increased to 500, the improvement in the product quality becomes slow, and the effect reduces the amount of energy increase caused by the increase in the reflux amount.

[0197] According to Embodiments 4, 9, and 12, even if the distillate amount and the purity of the feed liquid are changed while the reflux amount is constant, the product quality can be maintained. It is known that the amount of recycled distillate also depends on the moisture content and the impurity concentration of the feed liquid. However, even if it is too low, the removal amount of moisture and impurities is extremely reduced, so there is a limit. However, if the distillate rate is about 0.3% by weight, the quality can be maintained. The smaller the amount of recycled distillate, the lower the increase in the equipment size caused by the increase in the processing amount due to the recycling to the previous process. Therefore, it is preferably as small as possible. However, it is ideal to determine the optimum value in consideration of the quality and the overall balance.

[0198] According to Embodiment 13, even if the moisture concentration in the product column feed liquid is high, as long as the distillate amount and the reflux ratio of the product column are set to a certain high value, the product quality is satisfied.

[0199] It should be noted that in the 1,3-butanediol product obtained by the conventional method, there is no high-quality product having an initial boiling point higher than 203°C and a water content less than 0.4% by weight.

[0200] As a summary of the above, the configuration of the present disclosure and its variations are noted below.

[0201] [1] A method for producing 1,3-butanediol, which is a method for producing purified 1,3-butanediol from a reaction crude liquid containing 1,3-butanediol. In the method, the production method has a dehydration step of removing water by distillation, a high-boiling component removal step of removing high-boiling 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 feed liquid containing 1,3-butanediol is distilled under the condition that the reflux ratio exceeds 0.1 (or 0.15 or more), and a liquid in which low-boiling components are concentrated is distilled out from above the feed layer, and 1,3-butanediol is withdrawn from below the feed layer.

[0202] [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 aldol (or a crude reaction liquid obtained by hydrolysis of 1,3-epoxybutane, a crude reaction liquid obtained by selective hydrogenolysis of erythritol, a crude reaction liquid obtained by selective hydroaddition of 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).

[0203] [3]The method for producing 1,3-butanediol according to [2], wherein the aldol used as a raw material in the reduction (hydrogenation) of the aldol is any one of aldol, dimeric mesityl oxide as its cyclic dimer, 2,6-dimethyl-1,3-dioxan-4-ol as a cyclic trimer of acetaldehyde, and mixtures thereof.

[0204] [4]The method for producing 1,3-butanediol according to [2] or [3], wherein the crude reaction liquid containing the aldol is subjected to simple evaporation, distillation or hydrogenation to remove aldehydes, and then a hydrogenation step is carried out.

[0205] [5]The method for producing 1,3-butanediol according to any one of [2] to [4], wherein the content of the aldol used as a raw material in the reduction (hydrogenation) of the aldol is 30% by weight or more (for example, 30 to 99% by weight) (or 40% by weight or more (for example, 40 to 98% by weight), 50% by weight or more (for example, 50 to 97% by weight), 60% by weight or more (for example, 60 to 95% by weight), 65 to 90% by weight, 70 to 90% by weight, or 75 to 90% by weight).

[0206] [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 aldol contains water, and the content of the water is 2% by weight or more (or 5% by weight or more, 10% by weight or more, or 15% by weight or more), and the upper limit value of the content of the water is 90% by weight (or 80% by weight, 70% by weight, 60% by weight, 50% by weight, 40% by weight, 30% by weight or 20% by weight).

[0207] [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 aldol 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.

[0208] [8] According to the method for producing 1,3 - butanediol according to any one of [2] to [7] above, the amount of hydrogen used for the reduction (hydrogenation) reaction of the butyraldehydes 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.

[0209] [9] According to the method for producing 1,3 - butanediol according to any one of [2] to [8] above, the pressure (total pressure; gauge pressure) in the reaction system during the reduction (hydrogenation) reaction of the butyraldehydes is 9 to 70 MPa (or 10 to 40 MPa).

[0210]

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

[0211]

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

[10] above, the reaction temperature during the reduction (hydrogenation) reaction of the butyraldehydes is 40 to 150 °C (or 50 to 140 °C, or 60 to 130 °C).

[0212]

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

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

[0213]

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

[12] above, it further includes: a de - alcoholization step of removing low - boiling substances containing alcohol in the process stream containing the 1,3 - butanediol.

[0214]

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

[13] above, it further includes: a desalting step of removing salts in the process stream containing the 1,3 - butanediol.

[0215]

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

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

[0216]

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

[15] , wherein the high-boiling component removal column used in the high-boiling component removal step is a packed column (or a perforated plate column or a bubble cap column), and the reboiler used is a natural falling film evaporator or a forced stirring type thin film evaporator.

[0217]

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

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

[0218]

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

[16] or

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

[0219]

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

[16] to

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

[0220]

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

[16] to

[19] , wherein at least a part of the residue liquid of the high-boiling component removal column is recycled to the process before the high-boiling component removal step.

[0221]

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

[16] to

[20] , wherein the reflux ratio of the high-boiling component removal column 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).

[0222]

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

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

[0223]

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

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

[0224]

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

[23] above, wherein the addition amount of the base added in the base treatment is 0.05 to 10% by weight (or 0.1 to 1.0% by weight) based on the crude 1,3-butanediol stream to which the base treatment is applied.

[0225]

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

[23] or

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

[0226]

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

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

[0227]

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

[23] to

[26] above, wherein the reaction temperature of the base 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).

[0228]

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

[23] to

[27] above, wherein in the evaporator used for the base treatment, evaporation is carried out at 90 to 120 °C under reduced pressure with the absolute pressure at the top of the column being 20 kPa or less (or an absolute pressure of 0.5 to 10 kPa).

[0229]

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

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

[0230]

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

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

[0231]

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

[29] or

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

[0232]

[32] According to the method for producing 1,3-butanediol described in any one of

[29] to

[31] above, the reflux ratio in the product column 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).

[0233]

[33] According to the method for producing 1,3-butanediol described in any one of

[29] to

[32] above, the concentration of 1,3-butanediol in the feed liquid to the product column 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).

[0234]

[34] According to the method for producing 1,3-butanediol described in any one of

[29] to

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

[0235]

[35] According to the method for producing 1,3-butanediol described in any one of

[29] to

[34] above, the content of low-boiling components other than water in the feed liquid to the product column 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%).

[0236]

[36] According to the method for producing 1,3 - butanediol described in any one of

[29] to

[35] , 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, or 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).

[0237]

[37] According to the method for producing 1,3 - butanediol described in any one of

[29] to

[36] , at least a part 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 prior to these steps, which are steps before the product distillation step.

[0238]

[38] According to the method for producing 1,3 - butanediol described in

[37] , the amount of recycling of the distillate from the product column to the steps before the product distillation step is within the range of not more than the distillate amount in the product column and is less than 30% by weight relative to the charging amount to the product column.

[0239]

[39] According to the method for producing 1,3 - butanediol described in

[37] or

[38] , the amount of recycling of the distillate from the product column to the steps 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 charging amount to the product column.

[0240]

[40] A 1,3 - butanediol product having an initial boiling point higher than 203°C (or 204°C or higher, 205°C or higher, 206°C or higher, 207°C, or 208°C or higher) and a water content of less than 0.4% by weight (or 0.3% by weight or less, 0.2% by weight or less, 0.1% by weight or less, 0.07% by weight or less, 0.05% by weight or less, 0.03% by weight or less, 0.02% by weight or less, 0.01% by weight or less, or 0.005% by weight or less).

[0241]

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

[40] , wherein in the gas chromatography analysis under the following conditions, 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%, 99.4% or more, 99.5% or more, 99.6% or more, 99.7% or more, or 99.8% or more), and the total area ratio of the peaks with retention times shorter than the peak of 1,3 - butanediol is lower than 0.3% (or 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).

[0242] (Conditions for gas chromatography analysis)

[0243] Analysis column: A column with a stationary phase of dimethyl polysiloxane (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0244] Temperature - rising conditions: Heat from 80°C to 120°C at 5°C / minute, then heat to 160°C at 2°C / minute and hold for 2 minutes. Further, heat to 230°C at 10°C / minute and hold at 230°C for 18 minutes.

[0245] Sample introduction temperature: 250°C.

[0246] Carrier gas: Helium.

[0247] Gas flow rate of the column: 1 mL / minute.

[0248] Detector and detection temperature: Hydrogen flame ionization detector (FID), 280°C.

[0249]

[42] A humectant comprising the 1,3 - butanediol product according to

[40] or

[41] .

[0250]

[43] The humectant according to

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

[0251]

[44] A cosmetic comprising the humectant according to

[42] or

[43] .

[0252]

[45] The cosmetic according to

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

[0253] Industrial availability

[0254] The 1,3-butanediol product of the present disclosure can produce a high-purity 1,3-butanediol with a very low content of low-boiling 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 a moisturizer and a cosmetic that can maintain high quality for a long time.

[0255] Explanation of reference numerals

[0256] A: Dehydration tower

[0257] B: Desalting tower

[0258] C: High-boiling component removal distillation tower (high-boiling removal tower)

[0259] D: Alkali reactor

[0260] E: Alkali removal tower

[0261] F: Product distillation tower (product tower)

[0262] A-1, B-1, C-1, E-1, F-1: Condenser

[0263] A-2, C-2, F-2: Reboiler

[0264] X-1: Crude 1,3-butanediol

[0265] X-2: Water (drainage)

[0266] X-3: Salt, high-boiling components, and a part of 1,3-butanediol

[0267] X-4: High-boiling components and a part of 1,3-butanediol

[0268] X-5: Caustic soda, high-boiling components, and a part of 1,3-butanediol

[0269] X-6: Low-boiling components and a part of 1,3-butanediol

[0270] Y: 1,3-butanediol product

Claims

1. A method for producing 1,3 - butanediol, which is a method for producing purified 1,3 - butanediol from a crude reaction liquid containing 1,3 - butanediol, wherein, the production method has a dehydration step of removing water by distillation, a high - boiling component removal step of removing high - boiling 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 feed liquid containing 1,3 - butanediol is distilled under the condition that the reflux ratio exceeds 0.1, a liquid in which low - boiling components are concentrated is distilled off from above the feed layer, and 1,3 - butanediol is withdrawn from below the feed 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 aldol.

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

4. The method for producing 1,3 - butanediol according to any one of claims 1 to 3 further comprises: a desalting step of removing salts from a process stream containing 1,3 - butanediol.

5. The method for producing 1,3 - butanediol according to any one of claims 1 to 4 further comprises: a dealcoholization step of removing low - boiling components containing alcohol from a process stream containing 1,3 - butanediol.

6. The method for producing 1,3 - butanediol according to any one of claims 1 to 5, wherein, the reflux ratio of the product column is 0.2 or more.

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

8. The method for producing 1,3 - butanediol according to any one of claims 1 to 7, wherein, the water content in the feed liquid to the product column is 3 wt% or less.

9. The method for producing 1,3 - butanediol according to any one of claims 1 to 8, wherein, the content of low - boiling components other than water in the feed liquid to the product column is 1.8% or less.

10. The method for producing 1,3 - butanediol according to any one of claims 1 to 9, wherein, the distillate rate in the product column is set to be less than 30 wt%.

11. The method for producing 1,3 - butanediol according to any one of claims 1 to 10, wherein, the theoretical number of plates of the product column is 1 to 100.

12. The method for producing 1,3 - butanediol according to any one of claims 1 to 11, wherein, at least a part of the distillate of the product column is recycled to the dehydration step, the dealcoholization step, the low - boiling component removal step or the steps before these steps, which are the steps before the product distillation step.

13. The method for producing 1,3 - butanediol according to claim 12, wherein, the recycling amount of the distillate of the product column to the steps before the product distillation step is in the range of not more than the distillate amount in the product column and is less than 30 wt% relative to the feed amount to the product column.

14. The method for producing 1,3-butanediol according to claim 12 or 13, wherein the recycling amount of the distillate of the product column to the process before the product distillation process is within the range not exceeding the distillate amount in the product column and is 0.01% by weight or more based on the charging amount to the product column.

15. A 1,3-butanediol product having an initial boiling point higher than 203 °C and a water content of less than 0.4% by weight.

16. The 1,3-butanediol product according to claim 15, wherein in the gas chromatography analysis under the following conditions, the area ratio of the peak of 1,3-butanediol is higher than 98.5%, and the total area ratio of the peaks with retention times shorter than the peak of 1,3-butanediol is lower than 0.3%. Conditions for gas chromatography analysis: Analysis column: a column with a stationary phase of dimethylpolysiloxane, film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm; Temperature rising conditions: rising from 80 °C to 120 °C at 5 °C / minute, then rising to 160 °C at 2 °C / minute and holding for 2 minutes, further rising to 230 °C at 10 °C / minute and holding at 230 °C for 18 minutes; Sample introduction temperature: 250 °C; Carrier gas: helium; Gas flow rate of the column: 1 mL / minute; Detector and detection temperature: flame ionization detector (FID), 280 °C.

17. A humectant comprising the 1,3-butanediol product according to claim 15 or 16.

18. A cosmetic comprising the humectant according to claim 17.

Images