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

Abstract

The present invention provides a method for producing high-purity 1,3-butanediol with a high potassium permanganate test value, a very low content of low-boiling components, and a high initial boiling point at a high recovery rate. A method for producing 1,3-butanediol for obtaining purified 1,3-butanediol from a crude reaction liquid containing 1,3-butanediol. In a dehydration column used in a dehydration step, a feed liquid containing 1,3-butanediol and water and having an acetaldehyde content of 1000 ppm or less and a crotonaldehyde content of 400 ppm or less is distilled under a reflux ratio exceeding 0.3, and a low-boiling component concentrate containing water is distilled off from above the feed layer. In a product column used in a product distillation step, a 1,3-butanediol feed liquid having an acetaldehyde content of 500 ppm or less and a crotonaldehyde content of 200 ppm or less is distilled under a reflux ratio exceeding 0.1.

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing 1,3-butanediol and a 1,3-butanediol product. This application claims the priority of Japanese Patent Application No. 2019-239974, Japanese Patent Application No. 2019-239975, Japanese Patent Application No. 2019-239976, Japanese Patent Application No. 2019-239977, Japanese Patent Application No. 2019-239978, Japanese Patent Application No. 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

[0002] 1,3-Butanediol is a colorless, transparent, odorless liquid with 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, humectants, 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, expanding the demand in the cosmetics industry.

[0003] The reaction crude liquid during the manufacture of 1,3-butanediol contains a large amount of low-boiling impurities such as ethanol, butanol, acetaldehyde, crotonaldehyde, and esters. Among them, if acetaldehyde, crotonaldehyde, etc. dimerize or polymerize, high-boiling impurities are generated. In addition, in the purification process of 1,3-butanediol, low-boiling impurities and high-boiling impurities can also be generated by heat or the like. In 1,3-butanediol products, the fewer such impurities, the better. In Japanese Patent Laid-Open No. 6-329664, a method for controlling impurities derived from low-boiling impurities, namely crotonaldehyde, is disclosed. In Japanese Patent Laid-Open No. 2001-213828, it is disclosed that after the reaction crude liquid of 1,3-butanediol synthesized by the hydrogenation of aldol is alkalized and distilled to remove alcohols, and then distilled, high-purity 1,3-butanediol products can be manufactured with good yield and economically advantageously. In addition, this document describes the removal of low-boiling impurities, namely ethanol, isopropanol, and butanol, by distillation.

[0004] Prior Art Documents

[0005] Patent Documents

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

[0007] Patent Document 2: Japanese Patent Laid-Open No. 2001-213828 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] However, in existing methods, it is impossible to sufficiently remove the low-boiling components and high-boiling components from 1,3-butanediol. 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.

[0010] When 1,3-butanediol containing low-boiling components and high-boiling components is used in cosmetics, the liquid balance of the cosmetics is destroyed due to the increase in acid concentration, and the intended effects may be lost. In addition, due to the increase in the acid concentration of the cosmetics, skin roughness of users may also occur.

[0011] Furthermore, when the cosmetics are used and stored 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.

[0012] To solve such problems, it is required to remove by-products from crude 1,3-butanediol and purify 1,3-butanediol to high purity.

[0013] 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, there has been almost no technical research aimed at increasing the initial boiling point. In addition, as one of the product standards of 1,3-butanediol, there is a potassium permanganate test value (abbreviation: PMT), but in existing methods, the potassium permanganate test value of the obtained 1,3-butanediol product is not necessarily satisfactory. In addition, in the past, the substances causing the decrease in the potassium permanganate test value of the 1,3-butanediol product could not be specified.

[0014] Therefore, an object of the present disclosure is to provide a method for manufacturing high-purity 1,3-butanediol having a high potassium permanganate test value, a very low content of low-boiling components, and a high initial boiling point with a high recovery rate.

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

[0016] A further 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.

[0017] Technical solution

[0018] In order to achieve the above object, the inventors of the present disclosure conducted in-depth research and found that if the acetaldehyde content and crotonaldehyde content in the feed liquid flowing into the dehydration tower are specified, the reflux ratio of the dehydration tower is controlled, and at the same time the acetaldehyde content and crotonaldehyde content in the 1,3-butanediol feed liquid flowing into the product tower are specified, the reflux ratio of the product tower is controlled, and preferably the product tower distillate is recycled in the process before the product distillation process, then the low-boiling components mixed in the product tower feed liquid can be effectively removed, and the initial boiling point and potassium permanganate test value of 1,3-butanediol are maintained within the standard values, and at the same time the recovery rate of 1,3-butanediol can be maintained and increased. The present disclosure was completed based on these insights and further research.

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

[0020] 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.

[0021] In the dehydration tower used in the dehydration step, a feed liquid containing 1,3-butanediol and water, and having an acetaldehyde content of 1000 ppm or less and a crotonaldehyde content of 400 ppm or less, is distilled under the condition that the reflux ratio exceeds 0.3, and a low-boiling component concentrate containing water is distilled out from above the feed layer.

[0022] In the product tower used in the product distillation step, a 1,3-butanediol feed liquid having an acetaldehyde content of 500 ppm or less and a crotonaldehyde content of 200 ppm or less is distilled under the condition that the reflux ratio exceeds 0.1, a low-boiling component concentrate is distilled out from above the feed layer, and 1,3-butanediol is extracted from below the feed layer.

[0023] The reaction crude liquid containing the 1,3-butanediol may be a reaction crude liquid obtained by hydrogen reduction of butanol aldehydes.

[0024] The production method may further include an alkali treatment step of subjecting the process stream containing 1,3-butanediol to alkali treatment.

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

[0026] The production method may further include a dealcoholization step of removing low-boiling substances containing alcohols from the process stream containing 1,3-butanediol.

[0027] The acetaldehyde content in the feed liquid flowing into the dehydration tower may be 155 ppm or less, and the crotonaldehyde content in the feed liquid may be 117 ppm or less.

[0028] The water content in the charging liquid flowing into the dehydration tower may be 90% by weight or less.

[0029] The number of theoretical plates of the dehydration tower is, for example, 1 to 100 trays.

[0030] The concentration of 1,3 - butanediol in the charging liquid flowing into the product tower may be 90% GC area or more, and the water content in this charging liquid may be 3% by weight or less.

[0031] The content of low - boiling components other than water in the charging liquid flowing into the product tower may be 1.8% GC area or less.

[0032] The acetaldehyde content in the charging liquid flowing into the product tower may be 205 ppm or less, and the crotonaldehyde content in this charging liquid may be 110 ppm or less.

[0033] The distillate rate of the product tower may be less than 30% by weight.

[0034] The number of theoretical plates of the product tower is, for example, 1 to 100 trays.

[0035] At least a part of the distillate of the product tower can be recycled in the process before the product distillation process, that is, the dehydration process, the dealcoholization process, the removal of low - boiling components process, or the process before these processes.

[0036] The crude reaction liquid containing the 1,3 - butanediol is a crude reaction liquid obtained by the hydrogen reduction of butanol aldehydes, and at least a part of the distillate of the product tower can be recycled in the hydrogen reduction process of butanol aldehydes or in its upstream process.

[0037] Within the range of the distillate amount in the product tower, the recycling amount of the distillate of the product tower in the process before the product distillation process can be less than 30% by weight relative to the charging amount flowing into the product tower.

[0038] In addition, the present disclosure provides a 1,3 - butanediol product with an initial boiling point higher than 203 °C and a potassium permanganate test value of 30 minutes or more.

[0039] In the gas chromatography analysis under the following conditions, for the 1,3 - butanediol product, the peak area ratio of 1,3 - butanediol is higher than 98.7%, the total area ratio of the peaks with a retention time shorter than that of the 1,3 - butanediol peak is lower than 0.3%, the water content is less than 0.4% by weight, and in the GC - MS analysis under the following conditions, the acetaldehyde content is less than 2 ppm and the crotonaldehyde content is less than 1.2 ppm.

[0040] (Conditions for gas chromatography analysis)

[0041] Analysis column: A column with polydimethylsiloxane as the stationary phase (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0042] Temperature rising conditions: Heat from 80 °C to 120 °C at 5 °C per minute, then heat to 160 °C at 2 °C per minute and hold for 2 minutes. Further, heat to 230 °C at 10 °C per minute and hold at 230 °C for 18 minutes.

[0043] Sample introduction temperature: 250 °C.

[0044] Carrier gas: Helium.

[0045] Gas flow rate of the column: 1 mL / min.

[0046] Detector and detection temperature: Flame ionization detector (FID), 280 °C.

[0047] (Conditions for GC-MS analysis)

[0048] Analysis column: HP-1MS

[18] 30 m - 0.25 mm i.d. - 1.0 μm

[0049] Oven temperature: 80 °C (0 min) - 5 °C / min - 120 °C (0 min) - 2 °C / min - 160 °C (2 min) - 10 °C / min - 230 °C (18 min)

[0050] Carrier gas: He 0.61 mL / min, const.flow (linear velocity 29 cm / s)

[0051] Split: 20:1

[0052] Inj: 250 °C

[0053] AUX: 280 °C

[0054] Injection volume: 1 μL (ALS)

[0055] Ion source temperature: EI 230 °C, CI 250 °C

[0056] Quadrupole temperature: 150 °C

[0057] Sample: Directly used for analysis

[0058] The present disclosure also provides a humectant containing the 1,3-butanediol product.

[0059] In addition, the present disclosure also provides a cosmetic containing the humectant.

[0060] 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 constituent components (for example, the content of 1,3 - butanediol is 95% by weight or more, preferably 98% by weight or more).

[0061] Advantages of the Invention

[0062] According to the manufacturing method of the present disclosure, high - purity 1,3 - butanediol with a high potassium permanganate test value, a very low content of low - boiling components, and a high initial boiling point can be effectively manufactured industrially.

[0063] In addition, the 1,3 - butanediol product of the present disclosure has a high potassium permanganate test value, a very low content of low - boiling components, a high initial boiling point, and high purity. Therefore, it is suitable as a humectant and is also suitable for use as a raw material for cosmetics.

[0064] Furthermore, the humectants and cosmetics of the present disclosure have excellent moisture - retaining properties, and at the same time, the content of reducing substances and low - boiling components is extremely small. Therefore, high quality can be maintained for a long time. Brief Description of the Drawings

[0065] Figure 1 It is a flowchart of the manufacturing method (purification method) of the 1,3 - butanediol product of the present disclosure.

[0066] Figure 2 It is a chromatogram of the gas chromatography analysis of the 1,3 - butanediol product of Example 3.

[0067] Figure 3 It is a chromatogram of the gas chromatography analysis of the 1,3 - butanediol product of Comparative Example 2. Detailed Description of the Invention

[0068] [Method for Manufacturing 1,3 - Butanediol]

[0069] In the method for producing 1,3 - butanediol of the present disclosure, a method for producing purified 1,3 - butanediol from a crude reaction liquid containing 1,3 - butanediol (1,3BG) (hereinafter sometimes referred to as "crude 1,3 - butanediol") 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. Then, in the dehydration tower used in the dehydration step, a feed liquid containing 1,3 - butanediol and water, with an acetaldehyde content of 1000 ppm or less and a crotonaldehyde content of 400 ppm or less, is distilled under the condition that the reflux ratio exceeds 0.3, and a low - boiling component concentrate containing water is distilled out from above the feed layer. In the product tower used in the product distillation step, a 1,3 - butanediol feed liquid with an acetaldehyde content of 500 ppm or less and a crotonaldehyde content of 200 ppm or less is distilled under the condition that the reflux ratio exceeds 0.1, a low - boiling component concentrate is distilled out from above the feed layer, and 1,3 - butanediol is withdrawn from below the feed layer. The 1,3 - butanediol thus obtained has a high potassium permanganate test value, a very small content of low - and high - boiling components, and a high initial boiling point, and thus can be used as a 1,3 - butanediol product.

[0070] It should be noted that "GC area %" in this specification refers to the ratio of the peak area of this component to the total peak area in the gas chromatography analysis described below.

[0071] [Crude 1,3 - butanediol]

[0072] As the crude 1,3 - butanediol, for example, the following can be cited: (1) a crude reaction liquid obtained by reduction (hydrogenation) of butanol aldehydes; (2) a crude reaction liquid obtained by hydrolysis of 1,3 - epoxybutane; (3) a crude reaction liquid obtained by selective hydrocracking of erythritol; (4) a crude reaction liquid obtained by selective hydro - addition of butadiene; (5) a crude reaction liquid obtained by hydrogenation of n - butyraldehyde - 3 - one; (6) a crude reaction liquid obtained by hydrogenation of 1 - butanol - 3 - one; (7) a crude reaction liquid obtained by hydrogenation of 3 - hydroxy - 1 - butyric acid; (8) a crude reaction liquid obtained by hydrogenation of β - butyrolactone; and (9) a crude reaction liquid obtained by hydrogenation of diketene. In the present disclosure, the crude 1,3 - butanediol can 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 crude reaction liquid obtained by reduction (especially liquid - phase reduction) of butanol aldehydes in the above (1).

[0073] Hereinafter, the case where a crude reaction liquid obtained by reduction (hydrogenation) of butanol aldehydes is used as the crude 1,3 - butanediol will be mainly described. It should be noted that the step of reducing (hydrogenating) butanol aldehydes is sometimes referred to as the "hydrogenation step".

[0074] There is no particular limitation on the butyraldehydes used as raw materials in the hydrogenation process, provided that they are compounds that can be hydrogen-reduced to 1,3-butanediol. Examples of the raw material butyraldehydes include butyraldehyde, dimeric metahydroxybutyraldehyde as its cyclic dimer, 2,6-dimethyl-1,3-dioxan-4-ol as the cyclic trimer of acetaldehyde, and mixtures thereof.

[0075] There is no particular limitation on the method for producing butyraldehydes (e.g., butyraldehyde and dimeric metahydroxybutyraldehyde). For example, it can be obtained by the aldol condensation reaction of acetaldehyde in the presence of a basic catalyst, or by the thermal decomposition of 2,6-dimethyl-1,3-dioxan-4-ol. It should be noted that the process for producing butyraldehydes is sometimes referred to as the "butyraldehyde production process" or the "acetaldehyde polymerization process".

[0076] The reaction crude liquid containing butyraldehydes obtained by the above reaction is neutralized with an acid and used for the production of 1,3-butanediol. Such a reaction crude liquid may contain, in addition to butyraldehydes, 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, compounds having a boiling point lower than that of 1,3-butanediol are sometimes referred to as "low-boiling substances" or "low boilers", and compounds having a boiling point higher than that of 1,3-butanediol are sometimes referred to as "high-boiling substances" or "high boilers".

[0077] The reaction crude liquid containing the above butyraldehydes can be subjected to pretreatment such as alcohol distillation, dehydration distillation, desalting, alkali treatment and dealkalization treatment, impurity removal, etc. as needed to remove by-products such as unreacted acetaldehyde and crotonaldehyde. Examples of the pretreatment methods include distillation, adsorption, ion exchange, heating of high-boiling substances, decomposition, etc. Distillation can use various distillation methods such as vacuum distillation, atmospheric distillation, pressure distillation, azeotropic distillation, extraction distillation, and reaction distillation. In particular, it is preferred that the reaction crude liquid containing butyraldehydes is subjected to rough evaporation and distillation, hydrogenation to remove aldehydes such as acetaldehyde and crotonaldehyde, and then the hydrogenation process is carried out.

[0078] There is no particular limitation on the content of butyraldehydes in the hydrogenation raw material. For example, it is 30% by weight or more (e.g., 30 - 99% by weight), more preferably 40% by weight or more (e.g., 40 - 98% by weight), 50% by weight or more (e.g., 50 - 97% by weight) or 60% by weight or more (e.g., 60 - 95% by weight), further preferably 65 - 90% by weight, particularly preferably 70 - 90% by weight, and most preferably 75 - 90% by weight. When the content of butyraldehydes is within the above range, the impurities contained in the reaction crude liquid (crude 1,3-butanediol) containing 1,3-butanediol tend to decrease.

[0079] The hydrogenation feedstock may or may not contain water. However, from the perspective of the purity of the 1,3 - butanediol product, it is preferably water - containing. The water content in the hydrogenation feedstock 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 water content is within the above range, the amount of the acetal of 1,3 - butanediol and butyraldehyde contained in the obtained crude 1,3 - butanediol decreases, so 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 feedstock, the above - mentioned acetal hydrolyzes into 1,3 - butanediol, and at the same time, the co - generated butyraldehyde is reduced to 1,3 - butanediol.

[0080] As the hydrogenation catalyst, for example, Raney nickel can be cited. The hydrogenation catalyst can be used in a suspended state or filled into a reaction vessel for use. The amount of the hydrogenation catalyst used is not particularly limited. However, relative to 100 parts by weight of the hydrogenation feedstock, for example, it is preferably 1 - 30 parts by weight, more preferably 4 - 25 parts by weight, further preferably 8 - 20 parts by weight, and particularly preferably 12 - 18 parts by weight. The amount of hydrogen used for the reduction reaction is not particularly limited. However, relative to 100 parts by weight of the hydrogenation feedstock, for example, it is preferably 0.5 - 40 parts by weight, more preferably 1 - 30 parts by weight, further preferably 4 - 20 parts by weight, and particularly preferably 8 - 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 MPa - 70 MPa, preferably 10 MPa - 40 MPa. The hydrogen pressure (partial pressure of hydrogen) in the reaction system is not particularly limited. For example, it is 7 MPa - 60 MPa, preferably 10 MPa - 30 MPa. It should be noted that from the perspective of reducing reducing substances such as acetaldehyde and crotonaldehyde, it is better to increase the hydrogen pressure in the reaction system. It is preferably 10 MPa or more and can also be 100 MPa. The reaction temperature during the reduction reaction is not particularly limited. For example, it is 40°C - 150°C, preferably 50°C - 140°C, more preferably 60°C - 130°C. The reaction time (residence time) during the reduction reaction is not particularly limited. For example, it is 10 minutes - 500 minutes, preferably 20 minutes - 400 minutes, more preferably 30 minutes - 300 minutes, further preferably 50 minutes - 280 minutes, and particularly preferably 80 minutes - 250 minutes. This reaction can be carried out in any of the batch form, semi - batch form, or continuous form.

[0081] The resulting crude 1,3 - butanediol contains low - boiling substances (low - boiling compounds) with unsaturated bonds such as acetaldehyde (AD), butyraldehyde, crotonaldehyde (CR), acetone, methyl vinyl ketone, their condensation products, condensation products of 1,3 - butanediol and the above - mentioned low - boiling substances (for example, acetal bodies of 1,3 - butanediol and hydroxybutyraldehyde, etc.), alcohols such as ethanol, isopropanol, butanol, water (solvent, etc.), salts generated by neutralization treatment, etc., and catalysts (in the case of being used in a suspended state). By removing these impurities through a purification process, a 1,3 - butanediol product (purified 1,3 - butanediol) can be obtained.

[0082] [Purification of Crude 1,3 - Butanediol]

[0083] In the manufacturing method of the present disclosure, there are at least a dehydration process for removing water by distillation, a process for removing high - boiling components by distillation (high - boiling - component removal distillation process), and a product distillation process for obtaining purified 1,3 - butanediol. The dehydration process and the high - boiling - component removal process are both provided before the product distillation process, but the dehydration process and the high - boiling - component removal process do not have a specific order. In the manufacturing method of the present disclosure, in addition to these processes, a desalting process, an alkali reaction process (alkali treatment process), and a de - alkali process may also be included. In addition, before the dehydration process, a catalyst separation process, a neutralization process with an alkali, and an alcohol removal process (low - boiling - component removal process) may be provided. Each of the above processes can be carried out in the described order. Except that the de - alkali process is provided after the alkali reaction process, the order of each process can be appropriately changed. For example, the alcohol removal process (low - boiling - component removal process), the desalting process, the alkali reaction process, and the de - alkali process can be set at appropriate positions, usually after the hydrogenation process. It should be noted that the catalyst separation process, the neutralization process with an alkali, the alcohol removal process (low - boiling - component removal process), the desalting process, the alkali reaction process, and the de - alkali process in the above processes can be provided as needed and are not necessarily provided.

[0084] Figure 1 It is a flowchart of a device showing an example of an embodiment of the 1,3 - butanediol manufacturing method of the present disclosure. A is a dehydration tower, related to the dehydration process. B is a desalting tower, related to the desalting process. C is a high - boiling - component removal distillation tower (high - boiling - component removal tower), related to the high - boiling - component removal distillation process (high - boiling - component removal process). D is an alkali reactor, related to the alkali reaction process. E is a de - alkali tower, related to the de - alkali process. F is a product distillation tower (product tower), related to the product distillation process. 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 1,3 - butanediol manufacturing method of the present disclosure will be described using this flowchart.

[0085] 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. It should be noted that the above - mentioned crude 1,3 - butanediol (equivalent to "X - 1") can be supplied to the dehydration tower A after passing through a de - alcoholization process (a distillation process through a de - alcoholization tower) for removing alcohols and low - boiling substances such as ethanol.

[0086] In the manufacturing method of the present disclosure, in the dehydration tower A used in the dehydration process, a feed liquid containing 1,3 - butanediol and water, with an acetaldehyde content of 1000 ppm or less and a crotonaldehyde content of 400 ppm or less, is distilled under the condition that the reflux ratio exceeds 0.3, and a low - boiling component concentrate containing water (equivalent to Figure 1 "X - 2") is distilled out from above the feed layer (preferably the top of the tower). In addition, a crude 1,3 - butanediol stream containing 1,3 - butanediol is obtained from below the feed layer (preferably the bottom of the tower).

[0087] As the distillation tower for separating the dehydration tower A and other 1,3 - butanediol, 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.) etc. is more preferred. The reason is that 1,3 - butanediol and the contained trace impurities thermally decompose at high temperatures (e.g., 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 history (residence time) of 1,3 - butanediol is long. Therefore, the reboiler adopted is preferably one with a short residence time of the process - side fluid. For example, natural falling - film evaporators, scraping - agitated thin - film evaporators and other thin - film evaporators are preferred.

[0088] The number of theoretical plates of the dehydration tower A is, for example, 1 - 100 trays, preferably 2 - 80 trays, 3 - 80 trays, 4 - 60 trays, 5 - 40 trays, 6 - 30 trays or 7 - 20 trays, and more preferably 8 - 15 trays. The supply position of the feed liquid is from the top of the tower downward, and the tower height is, for example, 10% - 90% of the tower height, preferably 20% - 80%, more preferably 30% - 70%, and further preferably 40% - 60% of the tower height. In the distillation of the dehydration tower A, the pressure at the top of the tower (absolute pressure) is, for example, 101 kPa or less, preferably 0.1 kPa - 90 kPa, more preferably 0.5 kPa - 70 kPa, further preferably 1 kPa - 50 kPa, 2 kPa - 30 kPa or 3 kPa - 20 kPa, and particularly preferably 4 kPa - 10 kPa. It should be noted that the distillation of the dehydration tower A can be carried out under pressure. At this time, the pressure at the top of the tower (gauge pressure) can be, for example, 0.2 MPaG or less, or 0.1 MPaG or less.

[0089] The concentration of 1,3 - butanediol in the feed liquid flowing into dehydration tower A is, for example, 9 wt% or more, preferably 10 wt% or more, more preferably 15 wt% or more, further preferably 20 wt% or more, 25 wt% or more, 30 wt% or more, 35 wt% or more, 40 wt% or more, 45 wt% or more, 50 wt% or more, 55 wt% or more, or 60 wt% or more, and particularly preferably 70 wt% or more. The upper limit of the concentration of 1,3 - butanediol in the feed liquid flowing into dehydration tower A is, for example, 90 wt%, 85 wt% or 80 wt%. However, if considering the hydrogenation reaction and other processes before the dehydration process, there may be a case where a higher water concentration in the feed liquid flowing into the dehydration tower A is preferred. In summary, the concentration of 1,3 - butanediol in the feed liquid flowing into dehydration tower A can be, for example, 1 wt% or more, 5 wt% or more, 10 wt% or more, 15 wt% or more, 20 wt% or more, 25 wt% or more, 30 wt% or more, 35 wt% or more, 40 wt% or more, 50 wt% or more, 60 wt% or more, 70 wt% or more, 80 wt% or more, or 90 wt% or more. In addition, the concentration of 1,3 - butanediol in the feed liquid flowing into dehydration tower A can be, for example, 99 wt% or less, 95 wt% or more, 90 wt% or less, 85 wt% or less, 80 wt% or less, 75 wt% or less, 70 wt% or less, 65 wt% or less, 60 wt% or less, 55 wt% or less, 50 wt% or less, or 45 wt% or less. By adjusting, for example, the reaction conditions of the hydrogenation process (such as the concentration of butyraldehyde used as a raw material, etc.) and the distillation conditions of the alcohol - removing tower (low - boiling - point removing tower) set as needed before the dehydration tower, the concentration of 1,3 - butanediol in the feed liquid flowing into dehydration tower A can be within the above range.

[0090] It should be noted that the above - mentioned concentration of 1,3 - butanediol (wt%) is the ratio (GC area%) of the peak area of 1,3 - butanediol to the total peak area in the gas chromatography analysis under the following conditions, and the value obtained by the following formula. It should be noted that the concentration of water (wt%) in the feed liquid flowing into dehydration tower A is the value measured by the method (Karl Fischer method) described below.

[0091] The concentration of 1,3 - butanediol (wt%) in the feed liquid flowing into dehydration tower A

[0092] =(1 - the concentration of water (wt%) in the feed liquid flowing into dehydration tower A / 100) × the above - mentioned GC area% of 1,3 - butanediol

[0093] (Conditions for gas chromatography analysis)

[0094] Analysis column: A column with a stationary phase of polydimethylsiloxane (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0095] Temperature rising conditions: Heat from 80 °C to 120 °C at 5 °C per minute, then heat to 160 °C at 2 °C per minute and hold for 2 minutes. Further, heat to 230 °C at 10 °C per minute and hold at 230 °C for 18 minutes.

[0096] Sample introduction temperature: 250 °C.

[0097] Carrier gas: Helium.

[0098] Gas flow rate of the column: 1 mL / minute.

[0099] Detector and detection temperature: Flame ionization detector (FID), 280 °C.

[0100] In the manufacturing method of the present disclosure, the acetaldehyde content in the feed liquid flowing into the dehydration tower A is 1000 ppm or less, and the crotonaldehyde content is 400 ppm or less. The acetaldehyde content in the feed liquid flowing into the dehydration tower A can preferably be 900 ppm or less, more preferably 800 ppm or less, 700 ppm or less, 600 ppm or less, or 500 ppm or less, and further preferably 400 ppm or less, 300 ppm or less, 200 ppm or less, 155 ppm or less, or 140 ppm or less, 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, or 1 ppm or less.

[0101] The crotonaldehyde content in the feed liquid flowing into the dehydration tower A can preferably be 300 ppm or less, more preferably 200 ppm or less, and further preferably 150 ppm or less, 130 ppm or less, 117 ppm or less, or 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, or 1 ppm or less.

[0102] The acetaldehyde content and crotonaldehyde content in the feed liquid flowing into the dehydration tower A can be reduced by, for example, installing a de-alcoholization tower (low-boiling tower) upstream of the dehydration tower A and adjusting the distillation conditions of the de-alcoholization tower (low-boiling tower). For example, by increasing the reflux ratio, number of trays, and distillate rate of the de-alcoholization tower (low-boiling tower), the acetaldehyde content and crotonaldehyde content in the feed liquid flowing into the dehydration tower A can be reduced. Further, the hydrogenation reaction conditions in the hydrogenation process can also be adjusted. When the hydrogenation is complete, the concentrations of acetaldehyde and crotonaldehyde can be reduced to below the detection limit, but there will be disadvantages such as a higher reaction pressure and a larger reaction vessel.

[0103] It should be noted that the acetaldehyde content and crotonaldehyde content in the feed liquid flowing into the dehydration tower A can be quantified by GC-MS analysis (gas chromatography-mass spectrometry) as described below.

[0104] In the manufacturing method of the present disclosure, the water content in the feed liquid flowing into the dehydration tower A is, for example, 90% by weight or less, 85% by weight or less, 80% by weight or less, 70% by weight or less, 60% by weight or less, 50% by weight or less, or 40% by weight or less, preferably 35% by weight or less, more preferably 30% by weight or less, and further preferably 25% by weight or less. The lower limit of the water content in the feed liquid flowing into the dehydration tower A is, for example, 1% by weight, 5% by weight, 10% by weight, or 15% by weight. It should be noted that in consideration of the hydrogenation reaction in the hydrogenation process, the higher the water concentration and the lower the viscosity, the more favorable it is for the hydrogenation reaction due to the increased solubility and dispersion of hydrogen in the liquid. The water content in the feed liquid flowing into the dehydration tower A can be reduced by, for example, installing a de-alcoholization tower (low-boiling tower) upstream of the dehydration tower A and adjusting the distillation conditions of the de-alcoholization tower (low-boiling tower). For example, by increasing the reflux ratio, number of trays, and distillate rate of the de-alcoholization tower (low-boiling tower), the water content in the feed liquid flowing into the dehydration tower A can be reduced. It should be noted that the water content in the feed liquid flowing into the dehydration tower A can be quantified by a Karl Fischer moisture meter.

[0105] The content of components other than 1,3-butanediol, acetaldehyde, crotonaldehyde, and water in the feed liquid flowing into the dehydration tower A is, for example, 10% by weight or less, preferably 8% by weight or less, and more preferably 6% by weight or less.

[0106] In the manufacturing method of the present disclosure, the reflux ratio of dehydration column A [reflux amount of dehydration column / distillate amount of dehydration column (discharge amount to outside of distillation column)] is set to a value higher than 0.3. From the viewpoint of reducing the content of low-boiling substances (including water) in the crude 1,3-butanediol stream containing 1,3-butanediol taken out from below the charging layer (preferably the bottom of the column) of dehydration column A, the reflux ratio is preferably 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, 1.1 or more, 1.2 or more, 1.3 or more, 1.4 or more, 1.5 or more, 1.6 or more, 1.7 or more, 1.8 or more, 1.9 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 25 or more, and more preferably 30 or more (for example, 40 or more). From the viewpoint of energy consumption, the upper limit of the reflux ratio is, for example, 100, and preferably 50. It should be noted that when the number of theoretical plates of dehydration column A is large, the reflux ratio can be 10 or 20 or less, and sufficient separation can be achieved.

[0107] In the manufacturing method of the present disclosure, the distillate rate of dehydration column A can be appropriately set according to the concentration of water in the charging liquid flowing into dehydration column A. Preferably, the distillate rate is a sufficient distillate rate to distill all the water in the charging liquid. For example, when the concentration of water in the charging liquid flowing into dehydration column A is × wt%, the distillate rate of dehydration column A is preferably set to × wt% or more. Therefore, the distillate rate of dehydration column A is, for example, 95 wt% or less, 90 wt% or less, 85 wt% or less, 80 wt% or less, 75 wt% or less, 70 wt% or less, 65 wt% or less, 60 wt% or less, 55 wt% or less, 50 wt% or less, 45 wt% or less, 40 wt% or less, 35 wt% or less, 30 wt% or less, 25 wt% or less, 20 wt% or less, 15 wt% or less, 10 wt% or less, or 5 wt% or less. It should be noted that the above distillate rate refers to the ratio (wt%) of the liquid amount drawn out to the outside of the distillation column from above the charging layer (for example, the top of the column) of dehydration column A relative to the charging amount of dehydration column A.

[0108] In the manufacturing method of the present disclosure, the 1,3BG recovery rate of dehydration column A is, for example, 99.3% or more. It should be noted that in this specification, the 1,3BG recovery rate of dehydration column A is the value (%) obtained by the following formula.

[0109] {1 - [Concentration of 1,3 - BG in the distillate (wt%) × (Distillate quantity (parts) - Recycling quantity (parts))] / [Concentration of 1,3 - BG in the feed liquid (wt%) × Feed quantity (parts)]} × 100. It should be noted that there are cases where low - boiling substances and high - boiling substances are hydrolyzed by water to produce 1,3 - BG. On the other hand, there are also cases where high - boiling substances are produced by the polymerization of 1,3 - BG. Furthermore, there are also the generation and disappearance of trace impurities. Therefore, it is not always possible to achieve material balance in the dehydration column. This also applies to other distillation columns such as the de - alcohol column (de - low - boiling column), de - high - boiling column, and product column.

[0110] Next, the crude 1,3 - butanediol stream containing 1,3 - butanediol taken out from below the feed layer (preferably the bottom of the column) of the dehydration column A is supplied to the desalting column B. In the desalting column B, the desalted crude 1,3 - butanediol stream is obtained from the top of the column by distillation, and salts and high - boiling substances are discharged from the bottom of the column as the withdrawn liquid. The withdrawal rate (%) of the desalting column B [(Withdrawal quantity of the desalting column (parts)) / (Charging quantity of the desalting column (parts)) × 100] is, for example, 0.1 - 40 wt%, preferably 1 - 35 wt%, more preferably 2 - 30 wt%, further preferably 3 - 25 wt%, particularly preferably 5 - 20 wt%, and may also be 7 - 15 wt%. It should be noted that at least a part of the withdrawn liquid of the desalting column can be recycled in the process before the desalting process.

[0111] The above - mentioned desalted crude 1,3 - butanediol stream is supplied to the de - high - boiling column C. In the de - high - boiling column C, high - boiling components (high - boiling substances) are discharged from below the feed layer (preferably from the bottom of the column). On the other hand, a crude 1,3 - butanediol stream (1,3 - butanediol with higher purity) after removing high - boiling substances is obtained from above the feed layer.

[0112] As the de - high - boiling column C, 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 preferable. The reason is that 1,3 - butanediol and the contained trace impurities thermally decompose at high temperatures (for example, 150 °C or higher) to produce low - boiling substances as coloring components, so the distillation temperature is reduced. In addition, the same effect occurs when the thermal history (residence time) of 1,3 - butanediol is long. Therefore, the reboiler adopted is preferably one with a short residence time of the process - side fluid. For example, a natural falling - film evaporator, a scraping - agitation thin - film evaporator, etc. are preferred.

[0113] The number of plates of the high-boiling component removal column C, as the number of theoretical plates, is, for example, 1 to 100 plates, preferably 2 to 90 plates, more preferably 3 to 80 plates, further preferably 4 to 70 plates, 5 to 60 plates, 8 to 50 plates or 10 to 40 plates, and particularly preferably 15 to 30 plates. The supply position of the charged liquid is from the top of the high-boiling component removal column downward, and the column height is, for example, 10% to 90% of the column height, preferably 20% to 80%, more preferably 30% to 70%, and further preferably 40% to 60%. In the distillation of the high-boiling component removal column C, the pressure (absolute pressure) at the top of the column is, for example, 0.01 kPa to 50 kPa, preferably 0.1 kPa to 30 kPa, more preferably 0.3 kPa to 20 kPa, and further preferably 0.5 kPa to 10 kPa.

[0114] The reflux ratio of the high-boiling component removal column C [reflux amount of the high-boiling component removal column / distillate amount of the high-boiling component 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 viewpoint of energy consumption, the upper limit of the reflux ratio is, for example, 100 or less, preferably 50 or less. When the number of theoretical plates of the high-boiling component removal column C is large, even if the reflux ratio in the high-boiling component removal column C is about 1 or less, sufficient separation can be achieved.

[0115] The crude 1,3-butanediol stream taken out from above the charging layer of the high-boiling component 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. The alkali is added to the alkali reactor D or the 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 clogging. In addition, sometimes the decomposition reaction of high-boiling compounds may occur, and by-products may be generated instead. When the addition amount of the alkali is less than 0.05% by weight, the effect of decomposing by-products is small.

[0116] The base added to the base reactor D or the piping upstream thereof, etc. is not particularly limited, but for example, an alkali metal compound is preferred. Examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, (bi)sodium carbonate, and (bi)potassium carbonate. In addition, as the base, an alkaline ion exchange resin can be used. From the viewpoint of reducing by-products contained in the finally obtained 1,3-butanediol product, as the base, sodium hydroxide and potassium hydroxide are preferred. The base can be added directly as a solid substance, but for ease of operation 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 bases can be used alone or two or more thereof can be used simultaneously.

[0117] In the base reactor D, the reaction temperature 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 may increase. The reaction residence time is preferably, for example, 5 minutes to 120 minutes, more preferably 10 minutes to 30 minutes. When the reaction residence time is less than 5 minutes, the reaction may be insufficient and the quality of the finally obtained 1,3-butanediol product may deteriorate. If the reaction residence time exceeds 120 minutes, a large reactor becomes necessary and the equipment cost becomes high, so it is disadvantageous from the economic viewpoint.

[0118] After leaving the base reactor D, if necessary, the reaction crude liquid stream is supplied to a dealkalization tower (for example, a thin-film evaporator) E, and the base, etc. 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 history of the process fluid, the evaporator used for the dealkalization tower E is preferably a natural falling-film evaporator or a wiped-film evaporator with a short residence time. It should be noted that a demister can be provided in the space above the charging position of the dealkalization tower (for example, a thin-film evaporator) E to remove droplets of the base, etc. By providing the demister, it is possible to prevent the mixing of the base and high-boiling substances into the 1,3-butanediol product.

[0119] In the evaporator used for the dealkalization tower E, for example, evaporation is carried out under a reduced pressure of 20 kPa or less absolute pressure at the top of the tower, preferably 0.5 kPa to 10 kPa absolute pressure. The temperature of the evaporator is preferably, for example, 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.

[0120] It should be noted that the alkali reactor D and the alkali removal tower E can be arranged between the desalting tower B and the high-boiling-point removal tower C, between the dehydration tower A and the desalting tower B (in this case, the desalting tower can also serve as the alkali removal tower), or before the dehydration tower A. In addition, instead of arranging the alkali reactor D and the alkali removal tower E, alkali treatment can also be carried out by loading alkali into the high-boiling-point removal tower charging line or the dehydration tower charging line, or adding it to the reaction liquid after hydrogenation [and then loading it into the alcohol removal tower (low-boiling-point removal tower)].

[0121] In the manufacturing method of the present disclosure, in the product tower F used in the product distillation process, a 1,3-butanediol feed liquid with an acetaldehyde content of 500 ppm or less and a crotonaldehyde content of 200 ppm or less is distilled under the condition that the reflux ratio exceeds 0.1, and a low-boiling-point component concentrate (corresponding to Figure 1 "X-6") is distilled out from above the feed layer, and 1,3-butanediol product (corresponding to Figure 1 "Y") is extracted from below the feed layer.

[0122] As the product tower F, 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.) etc. is more preferred. The reason is that 1,3-butanediol and trace impurities contained therein thermally decompose at high temperatures (such as 150 °C or higher) to generate low-boiling-point substances as coloring components, so the distillation temperature is reduced. In addition, the same effect occurs when the thermal history (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 scraping and stirring thin-film evaporator is preferred.

[0123] The number of theoretical plates of the product tower F is, for example, 1 to 100 plates, preferably 2 to 90 plates, 3 to 80 plates, 4 to 70 plates, 5 to 60 plates, 8 to 50 plates or 10 to 40 plates, and more preferably 15 to 30 plates. The supply position of the feed liquid is from the top of the tower downward, and the tower height is, for example, 10% to 90% of the tower height, preferably 20% to 80%, more preferably 30% to 70%, and further preferably 40% to 60% of the tower height. For the distillation in the product distillation tower F, the pressure (absolute pressure) at the top of the tower is, for example, 20 kPa or less, preferably 0.1 kPa to 10 kPa, more preferably 0.3 kPa to 8 kPa, and further preferably 0.5 kPa to 5 kPa.

[0124] In Figure 1 , for the feed flowing into the product tower F, the liquid obtained by condensing the overhead steam of the alkali removal tower E using the condenser E-1 can be fed, or the overhead steam from the alkali removal tower E can also be directly fed to the product tower F.

[0125] The concentration of 1,3 - butanediol in the charging liquid (1,3 - butanediol charging liquid) flowing into product column F is, for example, 90% or more, preferably 92% or more, more preferably 95% or more, further preferably 97% or more, 97.1% or more, 97.2% or more, 97.3% or more, 97.4% or more, 97.5% or more, 97.6% or more, 97.7% or more, 97.8% or more, 97.9% or more, 98% or more, 98.1% or more, 98.2% or more, 98.3% or more, 98.4% or more, 98.5% or more, 98.6% or more, 98.7% or more, 98.8% or more, or 98.9% or more, and particularly preferably 99% or more. If the number of theoretical plates, reflux amount, and reflux ratio of product column F are sufficient, even if the concentration of 1,3 - butanediol in the charging liquid flowing into product column F is less than 90%, it can still be commercialized.

[0126] The concentration of 1,3 - butanediol in the charging liquid flowing into product column F can be increased, for example, by adjusting the distillation conditions of dehydration column A, or by installing a de - alcohol column (low - boiling - point removal column) before dehydration column A and adjusting its distillation conditions, or by adjusting the distillation conditions of high - boiling - point removal column C. For example, by increasing the reflux ratio of the de - alcohol column (low - boiling - point removal column), dehydration column A, and / or high - boiling - point removal column C, or by increasing the number of trays, the purity of 1,3 - butanediol in the charging liquid flowing into product column F can be increased.

[0127] It should be noted that the concentration of 1,3 - butanediol in the charging liquid flowing into the above - mentioned product column F is the ratio (area %) of the peak area of 1,3 - butanediol to the total peak area in the gas chromatography (GC) analysis under the following conditions.

[0128] (Conditions for gas chromatography analysis)

[0129] Analysis column: A column with a stationary phase of polydimethylsiloxane (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0130] 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.

[0131] Sample introduction temperature: 250°C.

[0132] Carrier gas: Helium.

[0133] Gas flow rate of the column: 1 mL / min.

[0134] Detector and detection temperature: Hydrogen flame ionization detector (FID), 280°C.

[0135] In the manufacturing method of the present disclosure, the acetaldehyde content in the charging liquid flowing into the product column F is 500 ppm or less, and the crotonaldehyde content is 200 ppm or less. The acetaldehyde content in the charging liquid flowing into the product column F is preferably 205 ppm or less (for example, 200 ppm or less), more preferably 150 ppm or less, further preferably 120 ppm or less, 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, or 10 ppm or less, particularly preferably 5 ppm or less, and may also be less than 2 ppm. The crotonaldehyde content in the charging liquid flowing into the product column F is preferably 150 ppm or less, more preferably 130 ppm or less, further preferably 110 ppm or less, 100 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, or 3 ppm or less, particularly preferably 2 ppm or less, and may also be less than 1 ppm. The acetaldehyde content and the crotonaldehyde content in the charging liquid flowing into the product column F can be reduced by, for example, providing a de-alcoholization column (low-boiling-point removal column) and a dehydration column upstream of the product column F and adjusting the distillation conditions of the de-alcoholization column (low-boiling-point removal column) and the dehydration column. For example, by increasing the reflux ratio, the number of trays, and the distillate rate of the de-alcoholization column (low-boiling-point removal column) and the dehydration column, the acetaldehyde content and the crotonaldehyde content in the charging liquid flowing into the product column F can be reduced. In addition, in the alkali reaction step, the acetaldehyde content and the crotonaldehyde content in the charging liquid flowing into the product column F can be reduced by increasing the reaction temperature, extending the residence time, or increasing the amount of alkali added, thereby reducing the acetaldehyde content and the crotonaldehyde content in the charging liquid flowing into the product column F. It should be noted that the acetaldehyde content and the crotonaldehyde content in the charging liquid flowing into the product column F can be quantified by GC-MS analysis (gas chromatography-mass spectrometry) as described below.

[0136] In the manufacturing method of the present disclosure, the water content in the charging liquid flowing into 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, further preferably 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, 1.2% by weight or less, 1.1% by weight or less, 1.0% 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 flowing into 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 concentration of water in the charging liquid flowing into the product column F can be reduced. It should be noted that the water content in the charging liquid flowing into the product column F can be quantified by a Karl Fischer moisture meter.

[0137] The content of low-boiling components (excluding water) in the charging liquid flowing into the product column F is, for example, 1.8% or less, preferably 1.6% or less, more preferably 1.4% or less, further preferably 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, 0.4% or less, 0.3% or less, or 0.2% or less, and particularly preferably 0.1% or less. The content of low-boiling components (excluding water) in the charging liquid flowing into the product column F is the total area ratio (area%) of the peaks with a retention time shorter than that of the peak of 1,3-butanediol in the gas chromatography analysis under the above conditions, relative to the total peak area. The content of low-boiling components (excluding water) in the charging liquid flowing into the product column F can be reduced, for example, by providing a de-alcoholization column (low-boiling-point removal column) upstream of the product column F and adjusting the distillation conditions of the de-alcoholization column (low-boiling-point removal column). For example, by increasing the reflux ratio, the number of trays, and the distillate rate of the de-alcoholization column (low-boiling-point removal column), the concentration of low-boiling components (excluding water) in the charging liquid flowing into the product column F can be decreased.

[0138] In the manufacturing method of the present disclosure, the reflux ratio of 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 improving 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).

[0139] In the manufacturing method of the present disclosure, by setting the 1,3-butanediol concentration, acetaldehyde content, crotonaldehyde content, and water content in the feed liquid flowing into dehydration column A within specific ranges, setting the reflux ratio of dehydration column A to a value equal to or higher than a specific value, and setting the water content in the feed liquid flowing into product column F to 1.2 wt% or less (preferably, the content of low-boiling components other than water in the feed liquid flowing into product column F to 1.8 wt% or less), and setting the reflux ratio of product column F within a specific range, high-purity 1,3-butanediol with a high potassium permanganate test value, a very low content of low-boiling components, and a high initial boiling point can be manufactured with a high recovery rate.

[0140] In the manufacturing method of the present disclosure, from the viewpoint of improving the recovery rate of 1,3-butanediol, the distillate rate of product column F, for example, is less than 30 wt%, preferably 29 wt% or less, more preferably 28 wt% or less, still more preferably 27 wt% or less, 26 wt% or less, 25 wt% or less, 24 wt% or less, 23 wt% or less, 22 wt% or less, 21 wt% or less, 20 wt% or less, 19 wt% or less, 18 wt% or less, 17 wt% or less, 16 wt% or less, 15 wt% or less, 12 wt% or less, 10 wt% or less, 8 wt% or less, 5 wt% or less, 3 wt% or less, 2 wt% or less, 1 wt% or less, 0.8 wt% or less, or 0.6 wt% or less, and particularly preferably 0.4 wt% or less. It should be noted that the above distillate rate refers to the ratio (wt%) of the amount of liquid (including the recycled amount in the case of recycling in the previous process described below) drawn out of the distillation column from above the feed layer of product column F (e.g., the top of the column) relative to the feed amount flowing into product column F.

[0141] At least a part of the low-boiling component concentrate (hereinafter, sometimes referred to as "distillate") drawn from above the feed layer of product column F can be recycled in the process before the product distillation process ( Figure 1 the dotted arrow on the right side of product column F shown). By recycling at least a part of the above distillate in the process before the product distillation process, the recovery rate of 1,3-butanediol can be improved.

[0142] As the process before the above product distillation process, for example, a dehydration process, a de-alcoholization process (low-boiling component removal process), etc. can be cited. It should be noted that the de-alcoholization process (low-boiling component removal process) is preferably provided before the dehydration process.

[0143] The recycling amount of the process before the product distillation process of the above distillate can be appropriately selected within the range of the amount of the distillate. With respect to the charging amount flowing into the product column F, the recycling amount of the process before the product distillation process of the above distillate is, for example, less than 30% by weight. In addition, from the viewpoints of improving the 1,3BG recovery rate of the product column and the yield of the entire process, with respect to the charging amount flowing into the product column F, the recycling amount of the process before the product distillation process of the above distillate is, for example, 0.01% by weight or more, preferably 0.05% by weight or more, more preferably 0.1% by weight or more, 0.5% by weight or more, 1% by weight or more, 1.5% by weight or more, 2% by weight or more, 3% by weight or more, 4% by weight or more, 5% by weight or more, 7% by weight or more, or 10% by weight or more, and particularly preferably 20% by weight or more.

[0144] Thus, according to the manufacturing method of the present disclosure, high-purity 1,3-butanediol with a high potassium permanganate test value, a very small content of low-boiling components, and a high initial boiling point can be manufactured with a high recovery rate.

[0145] The recovery rate of 1,3BG in the product column F is, for example, more than 80%, preferably 85% or more, more preferably 90% or more, further preferably 95% or more, and particularly preferably 99% or more.

[0146] It should be noted that in this specification, the 1,3BG recovery rate in the product column F is the value (%) obtained by the following formula.

[0147] {1 - [GC area% of 1,3BG in the distillate × (distillate amount (parts) - recycling amount (parts))] / (GC area% of 1,3BG in the feed liquid × feed amount (parts))} × 100

[0148] It should be noted that as described above, there are cases where low-boiling substances and high-boiling substances are hydrolyzed by water to generate 1,3BG, and on the other hand, there are also cases where high-boiling substances are generated by the polymerization of 1,3BG. Therefore, it is not always possible to achieve the material balance in the product column.

[0149] [1,3-Butanediol Product]

[0150] The 1,3 - butanediol product of the present disclosure can be obtained by the manufacturing method of the present disclosure described above. The initial boiling point of the 1,3 - butanediol product of the present disclosure is higher than 203°C, and the potassium permanganate test value (PMT) is 30 minutes or more. 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 or higher, and particularly preferably 208°C or higher. The potassium permanganate test value (PMT) is preferably more than 30 minutes (for example, 32 minutes or more), more preferably 35 minutes or more, further preferably 40 minutes or more, and particularly preferably 50 minutes or more (especially 60 minutes or more).

[0151] In addition, in the 1,3 - butanediol product of the present disclosure, in the gas chromatography analysis (GC analysis) under the following conditions, the peak area ratio of 1,3 - butanediol is preferably higher than 98.7%. In addition, the total area ratio of the peaks with a retention time shorter than that of the 1,3 - butanediol peak is preferably less than 0.3%.

[0152] (Conditions for gas chromatography analysis)

[0153] Analysis column: A column with a stationary phase of polydimethylsiloxane (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0154] Temperature - rising condition: 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.

[0155] Sample injection temperature: 250°C.

[0156] Carrier gas: Helium.

[0157] Gas flow rate of the column: 1 mL / minute.

[0158] Detector and detection temperature: Flame ionization detector (FID), 280°C.

[0159] The peak area ratio of the above - mentioned 1,3 - butanediol is preferably 98.8% or more, more preferably 98.9% or more, further preferably 99% or more, 99.1% or more, 99.2% or more, 99.3% or more, 99.4% or more, 99.5% or more, 99.6% or more, 99.7% or more, and particularly preferably 99.8% or more.

[0160] The total area ratio of the peaks with retention times shorter than that of the peak of 1,3 - butanediol is preferably 0.28% or less, more preferably 0.25% or less, still more preferably 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, or 0.007% or less, and particularly preferably 0.005% or less (for example, 0.002% or less).

[0161] It should be noted that in the present disclosure, the "area ratio" of a peak means the ratio (area %) of the area of a specific peak to the sum of the areas of all the peaks appearing in the chromatogram. In addition, all the 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.

[0162] In addition, in the 1,3 - butanediol product of the present disclosure, the water content is preferably less than 0.4% by weight. The water content is more preferably 0.3% by weight or less, still more preferably 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, 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 by a Karl Fischer moisture analyzer.

[0163] Furthermore, in the 1,3 - butanediol product of the present disclosure, the acetaldehyde content is preferably less than 2 ppm. In addition, the crotonaldehyde content is preferably less than 1.2 ppm. The acetaldehyde content and the crotonaldehyde content in the 1,3 - butanediol product can be quantified by GC - MS analysis (gas chromatography - mass spectrometry), for example, GC - MS analysis under the following conditions. In GC - MS analysis, even for very small peaks, all mass analyses are performed to quantify each component. To analyze a specific mass, even if other impurities overlap with the peak, substances with different masses will not be detected, and it has higher sensitivity than the aforementioned GC analysis. In this specification, the unit "ppm" of the content of each component in GC - MS analysis refers to "weight ppm".

[0164] (Conditions for GC - MS analysis)

[0165] Analysis column: A column with a stationary phase of polydimethylsiloxane (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0166] 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.

[0167] Sample introduction temperature: 250 °C.

[0168] Carrier gas: helium.

[0169] Gas flow rate of the column: 1 mL / min.

[0170] Ion source temperature: EI 230 °C, CI 250 °C

[0171] Quadrupole temperature: 150 °C

[0172] Sample: directly used for analysis

[0173] Under the conditions of the above GC-MS analysis, when the relative retention time of the peak of 1,3-butanediol is 1.0, the relative retention time of the peak of acetaldehyde is 0.3 - 0.5, and the relative retention time of the peak of crotonaldehyde is 0.3 - 0.5.

[0174] The acetaldehyde content in the 1,3-butanediol product is more preferably 1.8 ppm or less, further preferably 1.7 ppm or less, 1.5 ppm or less, 1.4 ppm or less, 1.3 ppm or less, 1.2 ppm or less, 1.1 ppm or less, 1.0 ppm or less, 0.9 ppm or less, 0.8 ppm or less, 0.7 ppm or less, 0.6 ppm or less, or 0.5 ppm or less, and particularly preferably 0.3 ppm or less (for example, 0.2 ppm or less). In addition, the crotonaldehyde content in the 1,3-butanediol product is more preferably 1.0 ppm or less, further preferably 0.9 ppm or less, 0.8 ppm or less, 0.7 ppm or less, 0.6 ppm or less, 0.5 ppm or less, 0.4 ppm or less, or 0.3 ppm or less, and particularly preferably 0.2 ppm or less (for example, 0.1 ppm or less).

[0175] By having the above initial boiling point and potassium permanganate test value within the above range, and further preferably having the peak area ratio of 1,3-butanediol, the total area ratio of peaks shorter than the peak of 1,3-butanediol in retention time, the acetaldehyde content, and the crotonaldehyde content within the above range, a high-purity and high-quality 1,3-butanediol product can be provided.

[0176] [Humectant and cosmetic]

[0177] The moisturizer of the present disclosure contains the above-mentioned 1,3-butanediol product. Therefore, it has excellent moisturizing performance. The moisturizer of the present disclosure may also contain components other than the above-mentioned 1,3-butanediol product, for example, moisturizer components other than the above-mentioned 1,3-butanediol product. In the moisturizer 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.

[0178] The cosmetic of the present disclosure contains the above-mentioned moisturizer. According to 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 only needs to be an amount that can exhibit moisturizing 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.

[0179] In addition to the above-mentioned 1,3-butanediol product, the cosmetic of the present disclosure may also contain, for example: other moisturizers; 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; pharmaceutical components and physiologically active components such as vitamin agents, skin activators, blood circulation promoters, whitening agents, antibacterial agents, and anti-inflammatory agents.

[0180] The cosmetic of the present disclosure can be made into: skin cosmetics such as lotion, emulsion, cream, gel, mask pack, and mask; hair cosmetics such as shampoo, conditioner, and hair growth agent. In addition, there can also be sunscreen cosmetics and makeup cosmetics. In addition, it can also be made into pharmaceuticals and skin care products formulated with medical components.

[0181] The cosmetic of the present disclosure can be manufactured by using a method known per se.

[0182] 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 each component in each embodiment are examples, and appropriate addition, omission, and other changes of the components can be made without departing from the gist of the present disclosure. The present disclosure is not limited by the embodiments, but only by the claims.

[0183] Examples

[0184] Hereinafter, the present disclosure will be described in more detail by way of examples, but the present disclosure is not limited by these examples. It should be noted that the "parts" used in the examples refer to "parts by weight" unless otherwise specified. Gas chromatography analysis (GC analysis), initial boiling point determination, and moisture measurement are carried out by the methods described below.

[0185] [Example 1]

[0186] Use Figure 1 to illustrate the method for manufacturing 1,3 - butanediol.

[0187] Relative to 100 parts of a hydroxybutyraldehyde solution containing 30% by weight of water as a raw material (a mixed solution containing 69 parts of hydroxybutyraldehyde and 29 parts of water, 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 is charged into a liquid - phase hydrogen reduction reactor, 15 parts of Raney nickel is added as a catalyst, and the reactor is maintained at 120°C and 10 MPa (gauge pressure) for liquid - phase hydrogen reduction. After separating the catalyst from the reacted liquid, it is neutralized with caustic soda to obtain crude 1,3 - butanediol (1) containing low - boiling impurities and water.

[0188] It should be noted that the hydroxybutyraldehyde 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 a residence time of 10 hours in the presence of 100 ppm by weight of NaOH [acetaldehyde polymerization step (aldol condensation step of acetaldehyde)].

[0189] The crude 1,3 - butanediol (1) (corresponding to Figure 1 "X - 1" in Figure 1 is charged into a dehydration column A. The concentration of 1,3 - butanediol in the feed liquid flowing into dehydration column A is 56% by weight, the concentration of water is 40% by weight, the acetaldehyde (AD) content is 130 ppm, the crotonaldehyde (CR) content is 89 ppm, and the content of other components is 4% by weight. In dehydration column A, distillation is carried out under the conditions of a top - tower pressure of 10 kPa (absolute pressure) and a reflux ratio of 1. Water is withdrawn from the top of the tower, and 43 parts (distillate amount) (corresponding to

[0190] "X - 2" in Figure 1("X-3" in it). The discharge amount of the evaporation residue is 5 parts relative to 100 parts of the charging liquid volume. 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 tower.

[0191] Next, the crude 1,3-butanediol (3) was charged into a high-boiling-point removal tower C. In the high-boiling-point removal tower C, distillation was carried out under the condition of a tower top pressure of 5 kPa (absolute pressure), and high-boiling substances and a part of 1,3-butanediol were discharged from the tower bottom (equivalent to Figure 1 "X-4" in it). The tower bottom discharge amount is 20 parts relative to 100 parts of the charging liquid volume. On the other hand, 80 parts of crude 1,3-butanediol (4) containing low-boiling substances as the distillate was obtained from the top of the tower.

[0192] Next, the crude 1,3-butanediol (4) was charged into an alkali reactor D. At this time, in order to make the concentration of caustic soda relative to the charging liquid reach 0.1 wt%, a 20 wt% aqueous caustic soda solution was added. The reaction temperature of the alkali reactor D was maintained at 120 °C, and the reaction was carried out with a residence time of 20 minutes.

[0193] Next, the reaction crude liquid leaving the alkali reactor D was charged into a de-alkali tower E. In the de-alkali tower E, caustic soda, high-boiling substances, and a part of 1,3-butanediol were discharged from the tower bottom (equivalent to Figure 1 "X-5" in it). The tower bottom discharge amount is 10 parts relative to 100 parts of the charging liquid volume. On the other hand, 90 parts of crude 1,3-butanediol (5) containing 1,3-butanediol and low-boiling substances was obtained from the top of the tower. The moisture content determination, GC analysis, and GC-MS analysis of the crude 1,3-butanediol (5) containing 1,3-butanediol and low-boiling substances showed that the moisture concentration was 1 wt%, the area ratio of 1,3-butanediol was 99%, the total area ratio of impurity peaks with a retention time shorter than that of 1,3-butanediol was 0.4%, the acetaldehyde content was 20 ppm, and the crotonaldehyde content was 9 ppm.

[0194] Next, the crude 1,3-butanediol (5) was charged into a product tower F. In the product tower F, 10 parts of low-boiling substances and a part of 1,3-butanediol (equivalent to Figure 1 "X-6" in it) were distilled from the top of the tower relative to 100 parts of the charging liquid volume, and all were discharged out of the system. At this time, it was operated at a reflux ratio of 0.5 (reflux amount / distillate amount), and 90 parts of 1,3-butanediol product (the distillate amount was 10 parts) was obtained from the tower bottom (equivalent to Figure 1 "Y" in it).

[0195] The obtained 1,3-butanediol product was subjected to initial boiling point determination, water content determination, GC analysis, and GC-MS analysis. The results were as follows: the initial boiling point was 203.3 °C, the water concentration was 0.2 wt%, the area ratio of 1,3-butanediol was 99.2%, the total area ratio of impurity peaks with a retention time shorter than that of 1,3-butanediol was 0.08%, the acetaldehyde content was 1.5 ppm, and the crotonaldehyde content was 0.9 ppm. In addition, the potassium permanganate test value was 35 minutes. The recovery rate of 1,3-butanediol in product column F was 90%.

[0196] [Example 2]

[0197] Except for changing the reflux ratio of dehydration column A to 50, the same operations as in Example 1 were carried out. A 1,3-butanediol product was obtained from the bottom of product column F. It should be noted that due to the change in the conditions of dehydration column A, the composition of the dehydration column distillate changed, and the feed liquid compositions of the high-boiling removal column C and product column F changed respectively, resulting in a change in the quality of the product.

[0198] The obtained 1,3-butanediol product was subjected to initial boiling point determination, water content determination, GC analysis, and GC-MS analysis. The results were as follows: the initial boiling point was 206.7 °C, the water concentration was 0.1 wt%, the area ratio of 1,3-butanediol was 99.3%, the total area ratio of impurity peaks with a retention time shorter than that of 1,3-butanediol was 0.05%, the acetaldehyde content was 0.7 ppm, and the crotonaldehyde content was 0.7 ppm. In addition, the potassium permanganate test value was 45 minutes. The recovery rate of 1,3-butanediol in product column F was 90%.

[0199] [Examples 3 to 18]

[0200] The dehydration column A and the product column F were operated under the conditions shown in Table 1 and Table 2. It should be noted that in Examples 4 to 15, 17, and 18, all the distillate from the product column F was recycled in the hydrogen reduction reactor.

[0201] [Comparative Example 1]

[0202] Except for changing the feed composition of the dehydration tower A, changing the reflux ratio of the dehydration tower A to 0.3, changing the distillate amount to 42 parts, changing the reflux ratio of the product tower F to 0.1, and changing the distillate amount to 20 parts, by the same method as in Example 1, 80 parts of 1,3-butanediol product were obtained from the bottom of the product tower F. The initial boiling point of the obtained 1,3-butanediol product was 193.2 °C, the water concentration was 0.6 wt%, the area ratio of 1,3-butanediol was 98.5%, the total area ratio of impurity peaks with a retention time shorter than that of 1,3-butanediol was 0.3%, the acetaldehyde content was 5 ppm, and the crotonaldehyde content was 4 ppm. In addition, the potassium permanganate test value was 0 minutes. The 1,3-butanediol recovery rate of the product tower F was 82%.

[0203] [Comparative Example 2]

[0204] Except for changing the feed composition of the dehydration tower A, changing the reflux ratio to 0.3, changing the distillate amount to 32 parts, changing the reflux ratio of the product tower F to 0.1, and changing the distillate amount to 20 parts, by the same method as in Example 1, 80 parts of 1,3-butanediol product were obtained from the bottom of the product tower F. The initial boiling point of the obtained 1,3-butanediol product was 199.0 °C, the water concentration was 0.4 wt%, the area ratio of 1,3-butanediol was 98.6%, the total area ratio of impurity peaks with a retention time shorter than that of 1,3-butanediol was 0.2%, the acetaldehyde content was 4 ppm, and the crotonaldehyde content was 3 ppm. In addition, the potassium permanganate test value was 5 minutes. The 1,3-butanediol recovery rate of the product tower F was 82%.

[0205] [Comparative Example 3]

[0206] Except for changing the feed composition of the dehydration tower A, changing the reflux ratio to 0.3, changing the distillate amount to 32 parts, changing the reflux ratio of the product tower F to 0.1, and changing the distillate amount to 30 parts, by the same method as in Example 1, 70 parts of 1,3-butanediol product were obtained from the bottom of the product tower F. The initial boiling point of the obtained 1,3-butanediol product was 203.0 °C, the water concentration was 0.2 wt%, the area ratio of 1,3-butanediol was 98.7%, the total area ratio of impurity peaks with a retention time shorter than that of 1,3-butanediol was 0.1%, the acetaldehyde content was 2 ppm, and the crotonaldehyde content was 1.2 ppm. In addition, the potassium permanganate test value was 30 minutes. The 1,3-butanediol recovery rate of the product tower F was 72%.

[0207] [Comparative Example 4]

[0208] Except for changing the charging composition of the dehydration tower A, changing the reflux ratio to 0.3, changing the distillate amount to 23 parts, changing the reflux ratio of the product tower F to 0.1, and changing the distillate amount to 20 parts, 80 parts of 1,3 - butanediol product was obtained from the bottom of the product tower F by the same method as in Example 1. The initial boiling point of the obtained 1,3 - butanediol product was 203.0 °C, the water concentration was 0.2 wt%, the area ratio of 1,3 - butanediol was 98.7%, the total area ratio of impurity peaks with a retention time shorter than that of 1,3 - butanediol was 0.1%, the acetaldehyde content was 2 ppm, and the crotonaldehyde content was 1.2 ppm. In addition, the potassium permanganate test value was 30 minutes. The recovery rate of 1,3 - butanediol in the product tower F was 81%.

[0209] [Gas Chromatography Analysis]

[0210] Gas chromatography analysis of the 1,3 - butanediol product was carried out under the following conditions. Figure 2 The chromatogram of the gas chromatography analysis of the 1,3 - butanediol product in Example 3 is shown. In addition, Figure 3 The chromatogram of the gas chromatography analysis of the 1,3 - butanediol product in Comparative Example 2 is shown.

[0211] (Conditions for Gas Chromatography Analysis)

[0212] Analysis device: Shimadzu GC2010.

[0213] Analysis column: A column with a stationary phase of polydimethylsiloxane (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm) (“Agilent J&W GC column - DB - 1”, manufactured by Agilent Technologies Japan, Ltd).

[0214] 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.

[0215] Sample introduction and temperature: Split sample introduction method, 250 °C.

[0216] Gas flow rate of the split and carrier gas: 23 mL / min, helium.

[0217] Gas flow rate of the column and carrier gas: 1 mL / min, helium.

[0218] Detector and temperature: Flame ionization detector (FID), 280 °C.

[0219] Injected sample: 0.2 μL of an 80 wt% aqueous solution of 1,3 - butanediol product

[0220] [Initial boiling point determination]

[0221] The determination is carried out according to the test method specified in the atmospheric distillation test method of JIS K2254 "Petroleum products - Distillation test method".

[0222] [Moisture determination]

[0223] The determination is carried out by a Karl Fischer moisture determination device.

[0224] [GC-MS analysis]

[0225] Analysis device: Agilent 6890A-GC / 5973A-MSD

[0226] Analysis column: A column with a stationary phase of polydimethylsiloxane (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0227] Temperature rising conditions: After rising from 80 °C to 120 °C at 5 °C / minute, it is then raised to 160 °C at 2 °C / minute and held for 2 minutes. Further, it is raised to 230 °C at 10 °C / minute and held at 230 °C for 18 minutes.

[0228] Sample introduction temperature: 250 °C.

[0229] Carrier gas: Helium.

[0230] Gas flow rate of the column: 1 mL / minute.

[0231] Ion source temperature: EI 230 °C, CI 250 °C

[0232] Quadrupole temperature: 150 °C

[0233] Sample: Directly used for analysis

[0234] [Potassium permanganate test]

[0235] In this specification, the potassium permanganate test value (PMT) is the value determined in sequence by the visual colorimetric method based on JIS K1351 (1993).

[0236] [Research results]

[0237] The results of the above comparative examples and examples are shown in Table 1 and Table 2.

[0238]

[0239]

[0240] From Comparative Examples 1, 2, and 4, it can be seen that when the reflux ratios of the dehydration tower and the product tower are relatively low, even if the charging composition of the dehydration tower (water, acetaldehyde, crotonaldehyde, others) is changed, the product quality will decline. From Comparative Examples 2 and 3, it can be seen that if the distillate amount of the product tower is significantly increased, low-boiling impurities can be removed, the initial boiling point and the potassium permanganate test value (PMT) can be improved, but the recovery rate of 1,3BG in the product tower decreases, so it is not economical. It should be noted that the separation of acetaldehyde and crotonaldehyde in the dehydration tower is more difficult than usual, and there is a possibility of generating acetaldehyde and crotonaldehyde in the tower.

[0241] From Comparative Example 1 and Example 1, it can be seen that when the charging composition of the dehydration tower is the same, if the reflux ratio and the distillate amount of the dehydration tower are increased, the low-boiling impurities including water in the dehydrated tower effluent will decrease. Further, by setting the reflux ratio of the product tower above a certain value, the product quality will be improved.

[0242] From Comparative Example 2 and Example 4, and Comparative Example 4 and Example 11, it can be seen that even if the distillate of the product tower is recycled, it can be reduced by adjusting the impurity content in the charging liquid of the product tower, and by increasing the reflux ratio of the product tower, a high-quality product can be recovered in high yield. It should be noted that if the water content in the charging liquid of the dehydration tower is reduced, even if the reflux ratio of the dehydration tower is the same, since the water content in the dehydrated tower effluent and the water content in the charging liquid of the downstream product tower will also decrease, the water content in the product will decrease and the initial boiling point will increase. The same is true for acetaldehyde and crotonaldehyde, but the effect does not reach the level of water content reduction.

[0243] From Examples 1 and 2, it can be seen that if the reflux ratio of the dehydration tower is increased, since the separation of low-boiling impurities including water, acetaldehyde, crotonaldehyde, and others is improved, the impurities in the charging liquid of the product tower and the product will decrease, so the product quality will be improved.

[0244] From Examples 2 and 3, it can be seen that under the same conditions of the dehydration tower, by increasing the reflux ratio of the product tower and minimizing the distillate amount of the product tower, while maintaining the same product quality, the recovery rate of 1,3BG in the product tower can be significantly increased, which is economically beneficial.

[0245] From Examples 6, 9, and 10, it can be seen that if the reflux ratio of the dehydration tower is increased, the separation of low-boiling impurities in the dehydration tower will be promoted, the impurities in the charging liquid of the product tower will be reduced, and thus the quality will be improved. However, if the reflux ratio of the dehydration tower is increased too much, the effect also tends to decrease. If the reflux ratio is increased too much, there will be an energy loss in the latent heat of evaporation, so it is preferable to set an upper limit on the increase of the reflux ratio.

[0246] In addition, as can be seen from Examples 6 to 8, if the reflux ratio of the product column increases significantly, the product quality will also increase significantly. However, if the reflux ratio of the product column is increased too much, the effect tends to decrease. If the reflux ratio is increased too much, energy loss in the latent heat of evaporation will occur. Therefore, it is preferable to set an upper limit on the increase in the reflux ratio.

[0247] The same applies to Examples 11 to 13. Even if the 1,3-BG concentration of the feed liquid to the dehydration column increases, if the reflux ratio of the dehydration column is increased, the separation of low-boiling impurities will be improved. However, if alkali treatment (treatment with an aqueous sodium hydroxide solution) is performed afterwards, since the water content of the product feed liquid hardly decreases, if dehydration is the only purpose, there is also a limit to the reflux ratio. However, if the reflux ratio is increased, since the separation of acetaldehyde and crotonaldehyde is improved, the PMT of the product tends to increase.

[0248] As can be seen from Comparative Examples 1 and 2 and Examples 14 to 16, even if the reflux ratio of the dehydration column is set to 0.3, as long as the reflux ratio and distillate amount of the product column are increased, high-quality products can be maintained.

[0249] As can be seen from Example 17, even if the water concentration of the feed liquid to the dehydration column is quite high, as long as the distillate amount and reflux ratio of the product column are relatively large, high-quality products can be maintained.

[0250] As can be seen from Example 18, even if the hydrogenation reaction is suppressed and the acetaldehyde content and crotonaldehyde content in the feed liquid to the dehydration column are increased, as long as the reflux ratios of the dehydration column and the product column are increased, the product quality can be maintained.

[0251] It should be noted that among the 1,3-butanediol products obtained by the existing methods, there are no high-quality products with an initial boiling point higher than 203 °C and a potassium permanganate test value exceeding 30 minutes.

[0252] As a summary of the above, the constitution and its variations of the present disclosure are noted below.

[0253] [1] A method for producing purified 1,3-butanediol from a reaction crude liquid containing 1,3-butanediol, comprising:

[0254] 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

[0255] In the dehydration column used in the dehydration step, a feed liquid containing 1,3-butanediol and water, with an acetaldehyde content of 1000 ppm or less (alternatively, 900 ppm or less, 800 ppm or less, 700 ppm or less, 600 ppm or less, 500 ppm or less, 400 ppm or less, 300 ppm or less, 200 ppm or less, 155 ppm or less, 140 ppm or less, 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, or 1 ppm or less) and a crotonaldehyde content of 400 ppm or less (alternatively, 200 ppm or less, 150 ppm or less, 130 ppm or less, 117 ppm or less, 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, or 1 ppm or less) is distilled under the condition that the reflux ratio exceeds 0.3 (alternatively, 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, 1.1 or more, 1.2 or more, 1.3 or more, 1.4 or more, 1.5 or more, 1.6 or more, 1.7 or more, 1.8 or more, 1.9 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, 25 or more, 30 or more, or 40 or more), and a low-boiling component concentrate containing water is distilled out from above the feed layer.

[0256] In the product column used in the product distillation process, a feed liquid of 1,3-butanediol with an acetaldehyde content of 500 ppm or less (alternatively, 205 ppm or less, 200 ppm or less, 150 ppm or less, 120 ppm or less, 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, or less than 2 ppm) and a crotonaldehyde content of 200 ppm or less (alternatively, 150 ppm or less, 130 ppm or less, 110 ppm or less, 100 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, or less than 1 ppm) is distilled under the condition that the reflux ratio exceeds 0.1 (alternatively, 0.15 or more, 0.2 or more, 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). A concentrated solution of low-boiling components is distilled out from above the feed layer, and 1,3-butanediol is extracted from below the feed layer.

[0257] [2] In the method for producing 1,3-butanediol according to [1] above, the crude reaction liquid containing the 1,3-butanediol is a crude reaction liquid obtained by hydrogen reduction of aldol.

[0258] [3] In the method for producing 1,3-butanediol according to [1] or [2] above, it further includes an alkali treatment step of subjecting the process stream containing 1,3-butanediol to alkali treatment.

[0259] [4] In the method for producing 1,3-butanediol according to any one of [1] to [3] above, it further includes a desalting step of removing salts from the process stream containing 1,3-butanediol.

[0260] [5] In the method for producing 1,3-butanediol according to any one of [1] to [4] above, it further includes a dealcoholization step of removing low-boiling substances containing alcohol from the process stream containing 1,3-butanediol.

[0261] [6]In the method for producing 1,3 - butanediol according to any one of [1] to [5] above, the acetaldehyde content in the feed liquid flowing into the dehydration tower is 155 ppm or less (alternatively, 140 ppm or less, 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, or 1 ppm or less), and the crotonaldehyde content in the feed liquid is 117 ppm or less (alternatively, 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, or 1 ppm or less).

[0262] [7]In the method for producing 1,3 - butanediol according to any one of [1] to [6] above, the water content in the feed liquid flowing into the dehydration tower is 90 wt% or less (alternatively, 85 wt% or less, 80 wt% or less, 70 wt% or less, 60 wt% or less, 50 wt% or less, 40 wt% or less, 35 wt% or less, 30 wt% or less, or 25 wt% or less).

[0263] [8]In the method for producing 1,3 - butanediol according to any one of [1] to [7] above, the number of theoretical plates of the dehydration tower is 1 to 100 trays.

[0264] [9] According to the method for producing 1,3-butanediol described in any one of [1] to [8] above, the concentration of 1,3-butanediol in the feed liquid flowing into the product column is 90 GC area% or more (alternatively, 92 GC area% or more, 95 GC area% or more, more preferably 97 GC area% or more, 97.1 GC area% or more, 97.2 GC area% or more, 97.3 GC area% or more, 97.4 GC area% or more, 97.5 GC area% or more, 97.6 GC area% or more, 97.7 GC area% or more, 97.8 GC area% or more, 97.9 GC area% or more, 98 GC area% or more, 98.1 GC area% or more, 98.2 GC area% or more, 98.3 GC area% or more, 98.4 GC area% or more, 98.5 GC area% or more, 98.6 GC area% or more, 98.7 GC area% or more, 98.8 GC area% or more, 98.9 GC area% or more, or 99 GC area% or more), and the water content in this feed liquid is 3 wt% or less (alternatively, 2.8 wt% or less, 2.6 wt% or less, 2.4 wt% or less, 2.2 wt% or less, 2 wt% or less, 1.8 wt% or less, 1.6 wt% or less, 1.4 wt% or less, 1.2 wt% or less, 1.1 wt% or less, 1.0 wt% or less, 0.95 wt% or less, 0.9 wt% or less, 0.8 wt% or less, 0.7 wt% or less, 0.6 wt% or less, 0.5 wt% or less, 0.4 wt% or less, 0.3 wt% or less, 0.2 wt% or less, or 0.1 wt% or less).

[0265]

[10] According to the method for producing 1,3-butanediol described in any one of [1] to [9] above, the content of low-boiling components other than water in the feed liquid flowing into the product column is 1.8 GC area% or less (alternatively, 1.6 GC area% or less, 1.4 GC area% or less, 1.2 GC area% or less, 1.1 GC area% or less, 1 GC area% or less, 0.9 GC area% or less, 0.8 GC area% or less, 0.7 GC area% or less, 0.6 GC area% or less, 0.5 GC area% or less, 0.4 GC area% or less, 0.3 GC area% or less, 0.2 GC area% or less, or 0.1 GC area% or less).

[0266]

[11] According to the 1,3 - butanediol production method described in any one of [1] to

[10] , the acetaldehyde content in the feed liquid flowing into the product column is 205 ppm or less (alternatively, 200 ppm or less, 150 ppm or less, 120 ppm or less, 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, or less than 2 ppm), and the crotonaldehyde content in this feed liquid is 110 ppm or less (alternatively, 100 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, or less than 1 ppm).

[0267]

[12] According to the 1,3 - butanediol production method described in any one of [1] to

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

[0268]

[13] According to the 1,3 - butanediol production method described in any one of [1] to

[12] , the number of theoretical plates of the product column is 1 to 100 trays.

[0269]

[14] According to the 1,3 - butanediol production method described in any one of [1] to

[13] , in the process before the product distillation process, that is, the dehydration process, the alcohol removal process, the low - boiling - point removal process, or the process before these processes, at least a part of the distillate from the product column is recycled.

[0270]

[15] According to the 1,3 - butanediol production method described in

[14] , the crude reaction liquid containing the 1,3 - butanediol is a crude reaction liquid obtained by hydrogen reduction of butanol aldehydes, and at least a part of the distillate from the product column is recycled in the hydrogen reduction process of butanol aldehydes or in the upstream process thereof.

[0271]

[16] According to the method for manufacturing 1,3-butanediol described in

[14] or

[15] , the recycling amount of the process before the product distillation step of the product tower distillate is less than 30% by weight relative to the feed amount flowing into the product tower within the range not exceeding the distillate amount of the product tower.

[0272]

[17] 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 higher, or 208 °C or higher), and a potassium permanganate test value of 30 minutes or more (or more than 30 minutes, 32 minutes or more, 35 minutes or more, 40 minutes or more, 50 minutes or more, or 60 minutes or more).

[0273]

[18] According to the 1,3-butanediol product described in

[17] , in the gas chromatography analysis under the following conditions, the peak area ratio of 1,3-butanediol is higher than 98.7% (or 98.8% or more, 98.9% or more, 99% or more, 99.1% or more, 99.2% or more, 99.3% or more, 99.4% or more, 99.5% or more, 99.6% or more, 99.7% or more, or 99.8% or more). Compared with the peak of 1,3-butanediol, the total area ratio of the peaks with a retention time shorter than that of 1,3-butanediol is less than 0.3% (or 0.28% or less, 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). The water content is 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), and the acetaldehyde content is less than 2 ppm (or 1.8 ppm or less, 1.7 ppm or less, 1.5 ppm or less, 1.4 ppm or less, 1.3 ppm or less, 1.2 ppm or less, 1.1 ppm or less, 1.0 ppm or less, 0.9 ppm or less, 0.8 ppm or less, 0.7 ppm or less, 0.6 ppm or less, 0.5 ppm or less, 0.3 ppm or less, or 0.2 ppm or less). The crotonaldehyde content is less than 1.2 ppm (or 1.0 ppm or less, 0.9 ppm or less, 0.8 ppm or less, 0.7 ppm or less, 0.6 ppm or less, 0.5 ppm or less, 0.4 ppm or less, 0.3 ppm or less, 0.2 ppm or less, or 0.1 ppm or less).

[0274] (Conditions for gas chromatography analysis)

[0275] Analysis column: A column with polydimethylsiloxane as the stationary phase (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0276] Temperature rising condition: 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.

[0277] Sample introduction temperature: 250°C.

[0278] Carrier gas: Helium.

[0279] Gas flow rate of the column: 1 mL / minute.

[0280] Detector and detection temperature: Flame ionization detector (FID), 280°C.

[0281]

[19] A humectant comprising the 1,3 - butanediol product described in

[17] or

[18] .[[]END]]

[0282]

[20] The humectant according to

[19] , wherein the content of the 1,3 - butanediol product described in

[17] or

[18] is 10% by weight or more (alternatively, 30% by weight or more, 50% by weight or more, 80% by weight or more, or 90% by weight or more).

[0283]

[21] A cosmetic comprising the humectant described in

[19] or

[20] .[[]END]]

[0284]

[22] The cosmetic according to

[21] , wherein the content of the 1,3 - butanediol product described in

[17] or

[18] is 0.01 - 40% by weight (alternatively, 0.1 - 30% by weight, 0.2 - 20% by weight, 0.5 - 15% by weight, or 1 - 10% by weight).

[0285]

[23] The cosmetic according to

[21] or

[22] , which is a skin cosmetic, a hair cosmetic, a sunscreen cosmetic, or a color cosmetic.

[0286] Industrial availability

[0287] According to the manufacturing method of the present disclosure, high-purity 1,3-butanediol with a high potassium permanganate test value, a very small content of low-boiling components, and a high initial boiling point can be effectively manufactured industrially. In addition, the 1,3-butanediol product of the present disclosure has a high potassium permanganate test value, a very small content of low-boiling components, a high initial boiling point, and high purity, so it is suitable as a humectant and is also suitable for use as a raw material for cosmetics. Further, the humectant and cosmetic of the present disclosure have excellent moisturizing performance, and at the same time, the content of reducing substances and low-boiling components is extremely small, so high quality can be maintained for a long time.

[0288] Description of Reference Numerals

[0289] A: Dehydration tower

[0290] B: Desalting tower

[0291] C: High-boiling substance removal distillation tower (high-boiling tower)

[0292] D: Alkali reactor

[0293] E: De-alkalization tower

[0294] F: Product distillation tower (product tower)

[0295] A-1, B-1, C-1, E-1, F-1: Condenser

[0296] A-2, C-2, F-2: Reboiler

[0297] X-1: Crude 1,3-butanediol

[0298] X-2: Water (drainage)

[0299] X-3: Salt, high-boiling substances, and a part of 1,3-butanediol

[0300] X-4: High-boiling substances and a part of 1,3-butanediol

[0301] X-5: Caustic soda, high-boiling substances, and a part of 1,3-butanediol

[0302] X-6: Low-boiling substances and a part of 1,3-butanediol

[0303] Y: 1,3-butanediol product

Claims

1. A method for manufacturing 1,3 - butanediol to obtain purified 1,3 - butanediol from a crude reaction liquid containing 1,3 - butanediol, comprising: A dehydration step of removing water by distillation; a step of removing high - boiling components by distillation; and a product distillation step for obtaining purified 1,3 - butanediol. In the dehydration column used in the dehydration step, a feed liquid containing 1,3 - butanediol and water, with an acetaldehyde content of 1000 ppm or less and a crotonaldehyde content of 400 ppm or less, is distilled under a reflux ratio exceeding 0.3, and a low - boiling component concentrate containing water is distilled out from above the feed layer. In the product column used in the product distillation step, a 1,3 - butanediol feed liquid with an acetaldehyde content of 500 ppm or less and a crotonaldehyde content of 200 ppm or less is distilled under a reflux ratio exceeding 0.1, a low - boiling component concentrate is distilled out from above the feed layer, and 1,3 - butanediol is extracted from below the feed layer.

2. The method for manufacturing 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 manufacturing 1,3 - butanediol according to claim 1 or 2, further comprising an alkali treatment step of subjecting a process stream containing 1,3 - butanediol to alkali treatment.

4. The method for manufacturing 1,3 - butanediol according to claim 1 or 2, further comprising a desalting step of removing salts from a process stream containing 1,3 - butanediol.

5. The method for manufacturing 1,3 - butanediol according to claim 1 or 2, further comprising a dealcoholization step of removing low - boiling substances containing alcohol from a process stream containing 1,3 - butanediol.

6. The method for manufacturing 1,3 - butanediol according to claim 1 or 2, wherein the acetaldehyde content in the feed liquid flowing into the dehydration column is 155 ppm or less, and the crotonaldehyde content in the feed liquid is 117 ppm or less.

7. The method for manufacturing 1,3 - butanediol according to claim 1 or 2, wherein the water content in the feed liquid flowing into the dehydration column is 90 wt% or less.

8. The method for manufacturing 1,3 - butanediol according to claim 1 or 2, wherein the number of theoretical plates of the dehydration column is 1 to 100 trays.

9. The method for manufacturing 1,3 - butanediol according to claim 1 or 2, wherein the concentration of 1,3 - butanediol in the feed liquid flowing into the product column is 90 GC area% or more, and the water content in the feed liquid is 3 wt% or less.

10. The method for manufacturing 1,3 - butanediol according to claim 1 or 2, wherein the content of low - boiling components other than water in the feed liquid flowing into the product column is 1.8 GC area% or less.

11. The method for manufacturing 1,3 - butanediol according to claim 1 or 2, wherein the acetaldehyde content in the feed liquid flowing into the product column is 205 ppm or less, and the crotonaldehyde content in the feed liquid is 110 ppm or less.

12. The method for manufacturing 1,3 - butanediol according to claim 1 or 2, wherein the distillate rate of the product column is less than 30 wt%.

13. The method for manufacturing 1,3-butanediol according to claim 1 or 2, wherein the number of theoretical plates of the product column is 1 to 100 trays.

14. The method for manufacturing 1,3-butanediol according to claim 1 or 2, in the process before the product distillation process, that is, the dehydration process, the low-boiling component removal process, or the process before these processes, at least a part of the distillate of the product column is recycled.

15. The method for manufacturing 1,3-butanediol according to claim 14, wherein the crude reaction liquid containing the 1,3-butanediol is a crude reaction liquid obtained by hydrogen reduction of butyraldehyde, and at least a part of the distillate of the product column is recycled in the hydrogen reduction process of the butyraldehyde or in the upstream process thereof.

16. The method for manufacturing 1,3-butanediol according to claim 14, wherein the recycling amount of the distillate of the product column in the process before the product distillation process is less than 30% by weight relative to the feed amount flowing into the product column within the range not exceeding the distillate amount of the product column.

Images