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

Abstract

The present invention provides a method for producing 1,3-butanediol with a high potassium permanganate test value. A method for producing 1,3-butanediol for obtaining purified 1,3-butanediol from a crude reaction liquid containing 1,3-butanediol, which comprises: a dehydration step of removing water by distillation; a high-boiling component removal step of removing high-boiling components by distillation; and a product distillation step for obtaining purified 1,3-butanediol. In the product column used in the product distillation step, a feed liquid with a 1,3-butanediol concentration of 97% or more, 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 an acetaldehyde and crotonaldehyde concentrate is distilled out from above the feed layer, and 1,3-butanediol is extracted from below the feed layer.

Description

Technical Field

[0001] The present disclosure relates to a method for producing 1,3 - butanediol and a 1,3 - butanediol product. This application claims the priority of Japanese Patent Application Nos. 2019 - 239974, 2019 - 239975, 2019 - 239976, 2019 - 239977, 2019 - 239978, 2019 - 239979 filed in Japan on December 28, 2019, Japanese Patent Application No. 2020 - 006660 filed in Japan on January 20, 2020, and Japanese Patent Application No. 2020 - 018910 filed in Japan on February 6, 2020, and incorporates their contents herein by reference. Background Art

[0002] 1,3 - Butanediol is a colorless, transparent, and odorless liquid, having properties such as low volatility, low toxicity, and high hygroscopicity, and excellent chemical stability. Therefore, the uses of 1,3 - butanediol include, among others, raw materials for various synthetic resins and surfactants, and span multiple aspects such as cosmetics, humectants, high - boiling - point 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 its demand in the cosmetics industry.

[0003] One of the product standards for 1,3 - butanediol is the potassium permanganate test value (abbreviation: PMT). Japanese Patent Application Laid - Open No. 2001 - 213825 discloses a 1,3 - butanediol whose potassium permanganate fading time of the product after 3 months of production is 5 minutes or more.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Laid - Open No. 2001 - 213825 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] However, in the methods of the above - mentioned prior art documents, the potassium permanganate test value of the obtained 1,3 - butanediol product may not be fully satisfactory. In addition, conventionally, the causative substances that reduce the potassium permanganate test value of the 1,3 - butanediol product could not be specified.

[0009] Therefore, an object of the present disclosure is to provide a method capable of producing 1,3 - butanediol having a high potassium permanganate test value.

[0010] Another object of the present disclosure is to provide a 1,3 - butanediol product having a high potassium permanganate test value.

[0011] Another further object of the present disclosure is to provide a humectant and a cosmetic that have excellent moisturizing properties and can maintain high quality for a long time.

[0012] Technical solution

[0013] The inventors of the present disclosure have conducted in-depth research to achieve the above object, and as a result, it has been found that if a charging liquid having a 1,3-butanediol concentration and an acetaldehyde content within a specific range is supplied to a product column and distilled at a specific reflux ratio, the potassium permanganate test value of the 1,3-butanediol product can be significantly increased. In addition, if the distillate of the product column is recycled in the process before the product distillation process, the potassium permanganate test value of the 1,3-butanediol product can be further increased, and even if the above method is implemented, the recovery rate of 1,3-butanediol can be maintained and increased. The present disclosure has been completed based on these insights.

[0014] That is, the present disclosure provides a method for producing purified 1,3-butanediol from a crude reaction liquid containing 1,3-butanediol, which has:

[0015] 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.

[0016] In the product column used in the product distillation step, a charging liquid having a 1,3-butanediol concentration of 97% or more, 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 an acetaldehyde and crotonaldehyde concentrate is distilled out from above the charging layer, and 1,3-butanediol is extracted from below the charging layer.

[0017] The crude reaction liquid containing 1,3-butanediol may be a crude reaction liquid obtained by hydrogen reduction of butanol aldehydes.

[0018] The manufacturing method may further include an alkali treatment step of subjecting the process stream containing 1,3-butanediol to alkali treatment.

[0019] The manufacturing method may further include a desalting step of removing salts from the process stream containing 1,3-butanediol.

[0020] The manufacturing method may further include a de-alcoholization step of removing low-boiling substances containing alcohol from the process stream containing 1,3-butanediol.

[0021] The reflux ratio of the product column may be 0.2 or more.

[0022] The acetaldehyde content in the charging liquid flowing into the product column may be 205 ppm or less.

[0023] The crotonaldehyde content in the charging liquid flowing to the product column may be 110 ppm or less.

[0024] The distillate rate in the product column may be less than 20% by weight.

[0025] The number of theoretical plates of the product column is, for example, 1 to 100 trays.

[0026] At least a part of the distillate of the product column can be recycled in the process before the product distillation process, that is, the dehydration process, the dealcoholization process, the de-low-boiling process, or the process before these processes.

[0027] The crude reaction liquid containing the 1,3-butanediol is a crude reaction liquid obtained by the hydrogen reduction of butyraldehydes, and at least a part of the distillate of the product column can be recycled in the hydrogen reduction process of butyraldehydes or in its upstream process.

[0028] Within the range below the distillate amount in the product column, the recycling amount of the distillate of the product column in the process before the product distillation process can be less than 30% by weight relative to the charging amount flowing to the product column.

[0029] Within the range below the distillate amount in the product column, the recycling amount of the distillate of the product column in the process before the product distillation process can be 0.01% by weight or more relative to the charging amount flowing to the product column.

[0030] In addition, the present disclosure provides a 1,3-butanediol product whose potassium permanganate test value exceeds 10 minutes.

[0031] In the 1,3-butanediol product, preferably, the peak area ratio of 1,3-butanediol in the gas chromatography analysis under the following conditions is higher than 98.5%.

[0032] (Conditions for gas chromatography analysis)

[0033] Analysis column: A column with a stationary phase of polydimethylsiloxane (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0034] Temperature rising condition: Heat from 80°C to 120°C at 5°C / min, then heat to 160°C at 2°C / min and hold for 2 minutes. Further, heat to 230°C at 10°C / min and hold at 230°C for 18 minutes.

[0035] Sample introduction temperature: 250°C.

[0036] Carrier gas: Helium.

[0037] Gas flow rate of the column: 1 mL / min.

[0038] Detector and detection temperature: Flame ionization detector (FID), 280 °C.

[0039] In the 1,3 - butanediol product, the acetaldehyde content is preferably 2 ppm or less.

[0040] In the 1,3 - butanediol product, the crotonaldehyde content is preferably 1.2 ppm or less.

[0041] The present disclosure also provides a humectant containing the 1,3 - butanediol product.

[0042] Furthermore, the present disclosure also provides a cosmetic containing the humectant.

[0043] 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 most of the constituent components (for example, the 1,3 - butanediol content is 95% by weight or more, preferably 98% by weight or more).

[0044] Advantages of the Invention

[0045] According to the manufacturing method of the present disclosure, 1,3 - butanediol with a high potassium permanganate test value can be manufactured.

[0046] Furthermore, the 1,3 - butanediol product of the present disclosure has a relatively high potassium permanganate test value. Therefore, it is suitable as a humectant and is also suitable for use as a raw material for cosmetics.

[0047] Furthermore, the humectant and cosmetic of the present disclosure have excellent moisturizing properties and extremely low levels of reducing substances, and thus can maintain high quality for a long time. Brief Description of the Drawings

[0048] Figure 1 It is a flowchart of the manufacturing method (purification method) of the 1,3 - butanediol product of the present disclosure.

[0049] Figure 2 It is a chromatogram of the gas chromatography analysis of the 1,3 - butanediol product of Example 13.

[0050] 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 Embodiments

[0051] [1,3 - Butanediol Manufacturing Method]

[0052] In the method for producing 1,3 - butanediol according to 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") has a dehydration step of removing water by distillation, a high - boiling component removal step of removing high - boiling components by distillation, and a product distillation step for obtaining purified 1,3 - butanediol. Then, in the product column used in the product distillation step, a feed liquid with a 1,3 - butanediol concentration of 97% or more, 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. An acetaldehyde and crotonaldehyde concentrate is distilled out from above the feed layer, and 1,3 - butanediol is drawn from below the feed layer. Since the potassium permanganate test value of this 1,3 - butanediol is high, it can be used as a 1,3 - butanediol product.

[0053] [Crude 1,3 - butanediol]

[0054] As the crude 1,3 - butanediol, for example, the following can be cited: (1) a crude reaction liquid obtained by the reduction (hydrogenation) of butanediols; (2) a crude reaction liquid obtained by the hydrolysis of 1,3 - epoxybutane; (3) a crude reaction liquid obtained by the selective hydrocracking of erythritol; (4) a crude reaction liquid obtained by the selective hydration of butadiene; (5) a crude reaction liquid obtained by the hydrogenation of n - butyraldehyde - 3 - one; (6) a crude reaction liquid obtained by the hydrogenation of 1 - butanol - 3 - one; (7) a crude reaction liquid obtained by the hydrogenation of 3 - hydroxy - 1 - butyric acid; (8) a crude reaction liquid obtained by the hydrogenation of γ - butyrolactone; and (9) a crude reaction liquid obtained by the 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, the crude reaction liquid obtained by the reduction (especially liquid - phase reduction) of butanediols is used.

[0055] Hereinafter, the case where a crude reaction liquid obtained by the reduction (hydrogenation) of butanediols is used as the crude 1,3 - butanediol will be mainly described. It should be noted that the step of reducing (hydrogenating) butanediols is sometimes referred to as the "hydrogenation step".

[0056] The butanediols used as raw materials in the hydrogenation step are not particularly limited as long as they are compounds that are hydrogen - reduced to 1,3 - butanediol. As the raw material butanediols, for example, the following can be cited: butanediol, dimeric metahydroxybutyraldehyde as its cyclic dimer, 2,6 - dimethyl - 1,3 - dioxane - 4 - ol as the cyclic trimer of acetaldehyde, and mixtures thereof.

[0057] The method for manufacturing butyraldehydes (e.g., 3-hydroxybutanal and dimer of 2-methylolpropionaldehyde) is not particularly limited. For example, it can be obtained by aldol condensation of acetaldehyde in the presence of a basic catalyst, or by thermal decomposition of 2,6-dimethyl-1,3-dioxane-4-ol, etc. It should be noted that the process for manufacturing butyraldehydes is sometimes referred to as the "butyraldehyde manufacturing process" or the "acetaldehyde polymerization process".

[0058] The reaction crude liquid containing butyraldehydes obtained by the above reaction is neutralized with an acid and used for manufacturing 1,3-butanediol. In such a reaction crude liquid, in addition to butyraldehydes, it may also contain acetaldehyde, crotonaldehyde, other aldehyde components, low-boiling substances, high-boiling substances such as aldehyde dimers or trimers, water, salts, etc. It should be noted that in this specification, compounds with a boiling point lower than that of 1,3-butanediol are sometimes respectively referred to as "low-boiling substances" or "low-boiling components", and compounds with a boiling point higher than that of 1,3-butanediol are respectively referred to as "high-boiling substances" or "high-boiling components".

[0059] 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 pretreatment methods include distillation, adsorption, ion exchange, heating of high-boiling substances to convert them, decomposition, etc. Distillation can use various distillation methods such as vacuum distillation, atmospheric distillation, pressure distillation, azeotropic distillation, extraction distillation, reaction distillation, etc. 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 a hydrogenation process is carried out.

[0060] The content of butyraldehydes in the hydrogenation raw material is not particularly limited. 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, there is a tendency for the impurities contained in the reaction crude liquid (crude 1,3-butanediol) containing 1,3-butanediol to decrease.

[0061] The hydrogenation feedstock may contain water or may not contain water, but from the viewpoint 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, still more 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, and thus there is a tendency for the purity of the finally obtained 1,3-butanediol product to be higher. The reason is that by containing a certain amount of water in the hydrogenation feedstock, the above acetal is hydrolyzed into 1,3-butanediol, and at the same time, the co-produced butyraldehyde is reduced to 1,3-butanediol.

[0062] As the hydrogenation catalyst, for example, Raney nickel and the like can be cited. The hydrogenation catalyst can be used in a suspended state or can be filled into a reaction vessel for use. The amount of the hydrogenation catalyst used is not particularly limited, but relative to 100 parts by weight of the hydrogenation feedstock, for example, it is preferably 1 to 30 parts by weight, more preferably 4 to 25 parts by weight, still more preferably 8 to 20 parts by weight, and particularly preferably 12 to 18 parts by weight. The amount of hydrogen used for the reduction reaction is not particularly limited, but relative to 100 parts by weight of the hydrogenation feedstock, for example, it is preferably 0.5 to 40 parts by weight, more preferably 1 to 30 parts by weight, still more preferably 4 to 20 parts by weight, and particularly preferably 8 to 12 parts by weight. The pressure (total pressure; gauge pressure) in the reaction system during the reduction reaction is not particularly limited. For example, it is 9 MPa to 70 MPa, preferably 10 MPa to 40 MPa. The hydrogen pressure (partial pressure of hydrogen) in the reaction system is not particularly limited. For example, it is 7 to 60 MPa, preferably 10 MPa to 30 MPa. The reaction temperature during the reduction reaction is not particularly limited. For example, it is 40°C to 150°C, preferably 50°C to 140°C, more preferably 60°C to 130°C. The reaction time (residence time) during the reduction reaction is not particularly limited. For example, it is 10 minutes to 500 minutes, preferably 20 minutes to 400 minutes, more preferably 30 minutes to 300 minutes, still more preferably 50 minutes to 280 minutes, and particularly preferably 80 minutes to 250 minutes. This reaction can be carried out in any of a batch form, a semi-batch form, or a continuous form.

[0063] 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 low-boiling substances (e.g., acetal bodies of 1,3-butanediol and butanol aldehyde, etc.), alcohols such as ethanol, isopropanol, butanol, water (solvent, etc.), salts generated by neutralization treatment, etc., and 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.

[0064] [Purification of Crude 1,3-Butanediol]

[0065] In the manufacturing method according to the present disclosure, there is 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 are not in a specific order. In the manufacturing method according to the present disclosure, in addition to these processes, a desalting process, an alkali reaction process (alkali treatment process), and a dealkalization 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. The above processes may be carried out in the described order, and except that the dealkalization process is provided after the alkali reaction process, the order of the processes may be appropriately changed. For example, the alcohol removal process (low-boiling component removal process), the desalting process, the alkali reaction process, and the dealkalization process may be provided 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 dealkalization process in the above processes may be provided as needed and are not necessarily provided.

[0066] Figure 1 It relates to a flowchart of an apparatus showing an example of an embodiment of the 1,3-butanediol manufacturing method according to 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 dealkalization tower, related to the dealkalization 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 according to the present disclosure will be described using this flowchart.

[0067] The crude 1,3 - butanediol obtained by hydrogen reduction of the hydrogenation raw material (equivalent to "X - 1") is supplied to the dehydration column A. In the dehydration column A, water is distilled off from the top of the column, and a crude 1,3 - butanediol stream containing 1,3 - butanediol is obtained from the bottom of the column. It should be noted that the above - mentioned crude 1,3 - butanediol (equivalent to "X - 1") can be supplied to the dehydration column A after passing through a de - alcoholization process (distillation process through a de - alcoholization column) for removing alcohols and low - boiling substances such as ethanol.

[0068] The above - mentioned crude 1,3 - butanediol stream is supplied to the desalting column B. In the desalting column B, a 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 a withdrawn liquid. The withdrawal rate (%) of the desalting column B [(amount of desalting column withdrawal (parts)) / (amount of desalting column feed (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 can 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.

[0069] The above - mentioned desalted crude 1,3 - butanediol stream is supplied to the high - boiling - point removal column C. In the high - boiling - point removal column C, high - boiling - point components (high - boiling substances) are discharged from below the charging 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 charging layer.

[0070] As the high - boiling - point removal 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 preferred. The reason is that 1,3 - butanediol and trace impurities contained therein 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 shorter residence time for the process - side fluid. For example, natural falling - film evaporators, scraping - agitation thin - film evaporators and other thin - film evaporators are preferred.

[0071] The number of trays in the high-boiling component removal column C, as the number of theoretical trays, is, for example, 1 to 100 trays, preferably 2 to 90 trays, more preferably 3 to 80 trays, further preferably 4 to 70 trays, 5 to 60 trays, 8 to 50 trays or 10 to 40 trays, and particularly preferably 15 to 30 trays. The supply position of the feed liquid is from the top of the high-boiling component removal column C downward, and the tower height is, for example, 10% to 90% of the tower height, preferably 20% to 80%, more preferably 30% to 70% of the trays, and further preferably 40% to 60% of the position. In the distillation of the high-boiling component removal column C, the pressure (absolute pressure) at the top of the tower 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.

[0072] 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, preferably 50.

[0073] The crude 1,3-butanediol stream taken out from above the feed tray of the high-boiling component removal column C is supplied to an alkali reactor (for example, 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 piping upstream thereof. The addition amount of the alkali relative to the crude 1,3-butanediol stream subjected to the alkali treatment is, for example, 0.05 to 10% by weight, preferably 0.1 to 1.0% by weight. If the addition amount of the alkali exceeds 10% by weight, the alkali may precipitate in the distillation column, piping, 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.

[0074] The alkali added to the alkali 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, (bi)potassium carbonate. In addition, as the said alkali, 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 alkali, sodium hydroxide and potassium hydroxide are preferred. The alkali can be added directly as a solid substance, but for the sake of operation and promoting contact with the liquid to be treated, it is preferably added as an aqueous solution. It should be noted that the above-mentioned alkali can be used alone or two or more kinds can be used simultaneously.

[0075] In the alkali 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, there will be a case where the coloring of the finally obtained 1,3-butanediol product increases. The reaction residence time is, for example, preferably 5 minutes to 120 minutes, more preferably 10 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 required and the equipment cost becomes high, so it is disadvantageous from the viewpoint of economy.

[0076] After leaving the alkali reactor D, if necessary, the reaction crude liquid stream is supplied to a dealkalization tower (for example, a thin-film evaporator) E, and the alkali, 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 alkali, etc. By providing the demister, it is possible to prevent the mixing of alkali and high-boiling substances into the 1,3-butanediol product.

[0077] In the evaporator used for the dealkalization tower E, for example, evaporation is carried out under a reduced pressure of 20 kPa or less, preferably 0.5 kPa to 10 kPa absolute pressure at the top of the tower. The temperature of the evaporator is, for example, preferably 90°C to 120°C. The crude 1,3-butanediol stream containing low-boiling substances distilled from the top of the tower is supplied to a product distillation tower (product tower) F.

[0078] 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 solution after hydrogenation [and then loading it into the alcohol removal tower (low-boiling-point removal tower)].

[0079] In the production method of the present disclosure, in the product tower F used in the product distillation process, a feed liquid with a 1,3-butanediol concentration of 97% or more, 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 an acetaldehyde and crotonaldehyde concentrate (corresponding to Figure 1 "X-6") is distilled out from above the feed layer, and 1,3-butanediol (corresponding to Figure 1 "Y") is extracted from below the feed layer. Since the potassium permanganate test value of this 1,3-butanediol is high, it can be directly used as a 1,3-butanediol product.

[0080] Examples of the product tower F include a perforated plate tower, a bubble cap tower, etc., but a packed tower with low pressure loss filled with Sulzer Packings, Mellapak (both are trade names of Sumitomo Heavy Industries, Ltd.) is more preferred. The reason is that 1,3-butanediol thermally decomposes at high temperature (for example, 150 °C or higher) to generate low-boiling substances as coloring components, so the distillation temperature is reduced. In addition, the same effect occurs when the thermal history (residence time) of 1,3-butanediol is long. Therefore, the reboiler used is preferably one with a shorter residence time of the process-side fluid. For example, a thin-film evaporator such as a natural falling film evaporator or a scraping and stirring thin-film evaporator is preferred.

[0081] 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%, preferably 20% to 80%, more preferably 30% to 70%, and further preferably 40% to 60% of the position. 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. The reflux ratio in the product distillation tower F is, for example, 0.05 to 500, preferably 0.1 to 300, more preferably 0.2 to 200, and further preferably 0.5 to 100, 1 to 50, 2 to 40, or 3 to 30, and particularly preferably 4 to 25.

[0082] In Figure 1 it, for the feed to product column F, the liquid feed obtained by condensing the overhead vapor of dealkalization column E using condenser E-1 can be used, or the overhead vapor from dealkalization column E can be directly fed to product column F.

[0083] The concentration of 1,3-butanediol in the feed liquid flowing to product column F is 97% or more, preferably 98% or more, and more preferably 99% or more. The concentration of 1,3-butanediol in the feed liquid flowing to product column F can be increased by, for example, adjusting the distillation conditions of dehydration column A, or by providing 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 said 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 feed liquid flowing to product column F can be increased. It should be noted that the above concentration of 1,3-butanediol is the ratio (area%) of the peak area of 1,3-butanediol to the total peak area in the gas chromatography analysis under the following conditions.

[0084] (Conditions for gas chromatography analysis)

[0085] Analysis column: A column with a stationary phase of polydimethylsiloxane (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0086] Temperature rising conditions: Starting from 80°C at a rate of 5°C / minute to 120°C, then rising to 160°C at a rate of 2°C / minute and holding for 2 minutes. Further, rising to 230°C at a rate of 10°C / minute and holding at 230°C for 18 minutes.

[0087] Sample introduction temperature: 250°C.

[0088] Carrier gas: Helium.

[0089] Gas flow rate of the column: 1 mL / minute.

[0090] Detector and detection temperature: Flame ionization detector (FID), 280°C.

[0091] In the manufacturing method of the present disclosure, the acetaldehyde content in the charging liquid flowing into the product column F is set to 500 ppm or less, and the crotonaldehyde content is set to 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 100 ppm or less, further preferably 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 110 ppm or less, more preferably 100 ppm or less, further preferably 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, installing 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. 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.

[0092] In the manufacturing method of the present disclosure, the reflux ratio in the product column F [product column reflux amount / product column distillate amount (discharge amount to the outside of the distillation column)] is set to a value greater than 0.1 (for example, 0.15 or more). From the viewpoint of improving the potassium permanganate test value 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, 11 or more, 12 or more, 13 or more, 14 or more, 15 or more, 16 or more, 17 or more, 18 or more, 19 or more, 20 or more, 25 or more, 30 or more, 35 or more, 40 or more, or 50 or more, particularly preferably 400 or more (for example, 500 or more).

[0093] In the manufacturing method of the present disclosure, the distillate rate of the product column F is preferably set to less than 20% by weight. It should be noted that the above distillate rate refers to the proportion (% by weight) of the liquid amount (including the recycled amount in the case of recycling in the previous process described below) withdrawn from above the charging layer of the product column F (for example, the top of the column) relative to the charging amount flowing into the product column F to the outside of the distillation column.

[0094] From the viewpoint of improving the recovery rate of 1,3 - butanediol, the distillate rate of the above product column F is preferably 15% by weight or less, more preferably 12% by weight or less, further preferably 10% by weight or less, 8% by weight or less, 5% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, 0.8% by weight or less, or 0.6% by weight or less, particularly preferably 0.4% by weight or less, and may also be 0.2% by weight or less.

[0095] At least a part of the low - boiling component concentrate (hereinafter, sometimes referred to as "distillate") extracted from above the charging layer of the product column F can be recycled in the process before the product distillation process ( Figure 1 the dotted arrow on the right side of the 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.

[0096] As the process before the above product distillation process, for example, a dehydration process, a de - alcoholization process (low - boiling point removal process), etc. can be cited. It should be noted that the high - boiling point removal process using the distillate of the high - boiling point removal column as a purified product does not become the object of recycling the distillate of the product column F, but when the purified product and the distillate containing low - boiling point substances are taken out from the side of the high - boiling point removal column and discarded or recycled in the upstream process such as the high - boiling point removal process, it can become the object of recycling the distillate of the product column F. The de - alcoholization process (low - boiling point removal process) is preferably provided before the dehydration process. In addition, when the reaction crude liquid containing the 1,3 - butanediol is a reaction crude liquid obtained by hydrogen reduction of butanol aldehydes, at least a part of the distillate of the product column can be recycled in the hydrogen reduction process (hydrogenation process) of the butanol aldehydes or its upstream process. By recycling at least a part of the distillate of the product column in the hydrogen reduction process (hydrogenation process) of the butanol aldehydes or its upstream process, reducing substances such as acetaldehyde and crotonaldehyde contained in the distillate of the product column can be rendered harmless by hydrogenation in the hydrogenation process. Therefore, it is possible to inhibit the accumulation of the reducing substances in the purification system and finally mixing into the 1,3 - butanediol product. In addition, accordingly, although it is not necessary to discharge the distillate of the product column out of the system, even if it is discharged out of the system, the amount is extremely small. Therefore, it is possible to achieve both the effects of improving the product quality and the product yield.

[0097] The recycling amount of the process before the product distillation process of the above-mentioned 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-mentioned 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-mentioned 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. However, considering the increase in the load at the recycling end leading to equipment enlargement, there is an upper limit to the recycling amount. With respect to the charging amount flowing into the product column F, it is preferably 90% by weight or less, more preferably 80% by weight or less, further preferably 70% by weight or less, 60% by weight or less, 50% by weight or less, or 40% by weight or less, and may also be 30% by weight or less.

[0098] Thus, according to the manufacturing method of the present disclosure, it is possible to manufacture high-quality 1,3-butanediol with very low acetaldehyde and crotonaldehyde contents and a high potassium permanganate test value at a normal high recovery rate. 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.

[0099] {1 - [GC area % of 1,3BG in the distillate × (distillate amount (parts) - recycling amount (parts))] / (GC area % of 1,3BG in the charging liquid × charging amount (parts))} × 100

[0100] It should be noted that low-boiling substances and high-boiling substances may hydrolyze with water to generate 1,3BG. On the other hand, high-boiling substances may also be generated by the polymerization of 1,3BG. Further, the generation and disappearance of trace impurities also occur, so it is not always possible to achieve material balance in the product column. This also applies to other distillation columns such as the alcohol removal column (low-boiling point removal column), dehydration column, and high-boiling point removal column.

[0101] [1,3-Butanediol Product]

[0102] The 1,3-butanediol product related to the present disclosure can be obtained by the manufacturing method related to the above-mentioned present disclosure. The potassium permanganate test value (PMT) of the 1,3-butanediol product of the present disclosure is higher than 10 minutes. The potassium permanganate test value is preferably 15 minutes or more, more preferably 30 minutes or more, further preferably 40 minutes or more, and particularly preferably 50 minutes or more (especially 60 minutes or more).

[0103] 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 98.5%.

[0104] (Conditions for gas chromatography analysis)

[0105] Analysis column: A column with a stationary phase of polydimethylsiloxane (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0106] 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.

[0107] Sample introduction temperature: 250 °C.

[0108] Carrier gas: Helium.

[0109] Gas flow rate of the column: 1 mL / minute.

[0110] Detector and detection temperature: Flame ionization detector (FID), 280 °C.

[0111] The peak area ratio of the above-mentioned 1,3-butanediol is preferably 98.6% or more, more preferably 98.7% or more, further preferably 98.8% or more, 98.9% or more, 99% or more, or 99.1% or more, particularly preferably 99.3% or more (for example, 99.5% or more), and may also be 99.8% or more.

[0112] 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.

[0113] In addition, in the 1,3-butanediol product of the present disclosure, the acetaldehyde content is preferably 2 ppm or less. In addition, the crotonaldehyde content is preferably 1.2 ppm or less. The acetaldehyde content and crotonaldehyde content in the 1,3-butanediol product can be quantified by GC-MS analysis (gas chromatography-mass spectrometry analysis), 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. In order to analyze a specific mass, even if other impurities overlap with the peak, substances with different masses will not be detected, and the sensitivity is higher than that of the above-mentioned GC analysis. In this specification, the unit "ppm" of the content of each component in GC-MS analysis refers to "weight ppm".

[0114] (Conditions for GC-MS analysis)

[0115] Analysis column: A column with a stationary phase of polydimethylsiloxane (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0116] Temperature rising conditions: After rising from 80 °C to 120 °C at 5 °C / min, it is then heated to 160 °C at 2 °C / min and held for 2 minutes. Further, it is heated to 230 °C at 10 °C / min and held at 230 °C for 18 minutes.

[0117] Sample introduction temperature: 250 °C.

[0118] Carrier gas: Helium.

[0119] Gas flow rate of the column: 1 mL / min.

[0120] Ion source temperature: EI 230 °C, CI 250 °C

[0121] Quadrupole temperature: 150 °C

[0122] Sample: Directly used for analysis

[0123] Under the above conditions for 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.

[0124] The acetaldehyde content in the 1,3-butanediol product is more preferably 1.7 ppm or less, further preferably 1.5 ppm or less, particularly preferably 1.2 ppm or less, 1.0 ppm or less, 0.7 ppm or less, 0.5 ppm or less, 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 0.7 ppm or less, particularly preferably 0.5 ppm or less, 0.3 ppm or less, or 0.2 ppm or less (for example, 0.1 ppm or less).

[0125] Since the peak area ratio of 1,3-butanediol, the acetaldehyde content, and the crotonaldehyde content in the 1,3-butanediol product are within the above ranges, it is possible to provide a high-purity and high-quality 1,3-butanediol product.

[0126] [Humectant and cosmetic]

[0127] The humectant of the present disclosure contains the above-mentioned 1,3-butanediol product. Therefore, it has excellent moisturizing performance. The humectant of the present disclosure may also contain components other than the above-mentioned 1,3-butanediol product, for example, humectant components other than the above-mentioned 1,3-butanediol product. In the humectant of the present disclosure, the content of the above-mentioned 1,3-butanediol product is, for example, 10% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more, further preferably 80% by weight or more, particularly preferably 90% by weight or more, and may also consist only of the above-mentioned 1,3-butanediol product.

[0128] The cosmetic of the present disclosure contains the above-mentioned humectant. Depending on the type and form of the cosmetic, the blending amount of the above-mentioned 1,3-butanediol product in the cosmetic of the present disclosure may be any amount that can exhibit 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.

[0129] In addition to the above-mentioned 1,3-butanediol product, the cosmetic of the present disclosure may also contain, for example: other humectants; oil agents such as vegetable oils, hydrocarbon oils, higher fatty acids, higher alcohols, and silicones; surfactants such as anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants; preservatives, chelating agents, thickeners, powders, ultraviolet absorbers, ultraviolet blockers, fragrances, pH regulators; pharmaceutical components and physiologically active components such as vitamin agents, skin activators, blood circulation promoters, whitening agents, antibacterial agents, and anti-inflammatory agents.

[0130] The cosmetic of the present disclosure can be made into: skin cosmetics such as lotions, emulsions, creams, gels, mask packs, and masks; hair cosmetics such as shampoos, conditioners, and hair growth agents. 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.

[0131] The cosmetic of the present disclosure can be manufactured by using a method known per se.

[0132] 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 configuration and the combination of each configuration in each embodiment are examples, and additional, omitted, and other changes to the configuration can be made appropriately within the scope not departing from the gist of the present disclosure. The present disclosure is not limited by the embodiments, but only by the claims.

[0133] Examples

[0134] Hereinafter, the present disclosure will be described more specifically 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. By the methods described below, gas chromatography analysis (GC analysis), GC-MS analysis (gas chromatography-mass spectrometry analysis), and potassium permanganate test were carried out.

[0135] [Example 1]

[0136] Use Figure 1 to illustrate the method for manufacturing 1,3-butanediol.

[0137] Relative to 100 parts of a butyraldehyde solution containing 30% by weight of water as a raw material (a mixed solution containing 69 parts of butyraldehyde 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 were charged into a liquid-phase hydrogen reduction reactor, 15 parts of Raney nickel as a catalyst were added, and the reactor was maintained at 120 °C and 10 MPa (gauge pressure) for liquid-phase hydrogen reduction. After the reaction liquid was separated from the catalyst, it was neutralized with caustic soda to obtain crude 1,3-butanediol (1) containing low-boiling impurities and water.

[0138] It should be noted that the butyraldehyde solution containing 30% by weight of water used as a raw material was prepared 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)].

[0139] The crude 1,3-butanediol (1) (corresponding to Figure 1 "X-1" in) was charged into a dehydration column A. In dehydration column A, relative to 100 parts of the feed liquid volume, water was withdrawn from the top of the column, 15 parts of fresh water were added as reflux water, the top pressure of the column was 7 kPa (absolute pressure), and crude 1,3-butanediol (2) with 1% by weight of water and a total area ratio of impurity peaks shorter than the retention time (retention time, RT) of 1,3-butanediol in the GC analysis described below of 1.8% was obtained from the bottom of the column. It should be noted that the water withdrawn from the top of the column (corresponding to Figure 1 "X-2" in) was discharged.

[0140] Next, the crude 1,3-butanediol (2) was charged into a desalting column B. In desalting column B, salts, high-boiling substances, and a part of 1,3-butanediol were discharged as evaporation residues from the bottom of the column (corresponding to Figure 1 "X-3" in). The discharge amount of the evaporation residue was 5 parts relative to 100 parts of the feed 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 column.

[0141] Next, the crude 1,3-butanediol (3) is fed to the high boiling point removal column C. In the high boiling point removal column C, high boiling point substances and a portion of 1,3-butanediol (equivalent to Figure 1 The amount of the column bottom discharge was 20 parts relative to 100 parts of the loading liquid. On the other hand, 80 parts of crude 1,3-butanediol (4) containing low boiling point substances was obtained as a distillate from the top of the column.

[0142] Next, crude 1,3-butanediol (4) was charged into the alkali reactor D. At this time, a 20 wt % caustic soda aqueous solution was added so that the concentration of caustic soda relative to the charge liquid was 0.1 wt %. 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.

[0143] Next, the crude reaction liquid discharged from the alkali reactor D is fed into the dealkalization tower E. In the dealkalization tower E, caustic soda, high boiling point substances, and a portion of 1,3-butanediol (equivalent to Figure 1 "X-5" in the column). The amount discharged from the bottom of the column was 10 parts relative to 100 parts of the loading liquid. On the other hand, 90 parts of crude 1,3-butanediol (5) containing 1,3-butanediol and low-boiling substances were obtained from the top of the column. The crude 1,3-butanediol (5) containing 1,3-butanediol and low-boiling substances was subjected to GC analysis and GC-MS analysis. The results showed that the GC area ratio of 1,3-butanediol was 97%, the acetaldehyde content was 43 ppm, and the crotonaldehyde content was 15 ppm.

[0144] Next, the crude 1,3-butanediol (5) was charged into the product distillation column F. In the product distillation column F, 10 parts of low boiling point substances and a portion of 1,3-butanediol (equivalent to 100 parts of the charged liquid) were distilled from the top of the column. Figure 1 At this time, the tower was operated at a reflux ratio (reflux volume / distillate volume) of 0.3, and 90 parts of 1,3-butanediol products (distillate rate 10% by weight) were obtained from the bottom of the tower (equivalent to Figure 1 in the text box).

[0145] The obtained 1,3-butanediol product was subjected to GC analysis and GC-MS analysis, and the results showed that the GC area ratio of 1,3-butanediol was 98.6%, the acetaldehyde (AD) content was 2 ppm, and the crotonaldehyde (CR) content was 1.2 ppm. In addition, the potassium permanganate test value was 30 minutes. The 1,3-butanediol recovery rate of product tower F was 92%.

[0146] [Example 2]

[0147] Except for changing the reflux ratio of product column F to 1, 90 parts of 1,3-butanediol product were obtained from the bottom of product column F by the same method as in Example 1. The obtained 1,3-butanediol product was subjected to GC analysis and GC-MS analysis. The results were as follows: the GC area ratio of 1,3-butanediol was 98.7%, 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 1,3-butanediol recovery rate of product column F was 92%.

[0148] [Example 3]

[0149] Except for setting the reflux ratio of product column F to 1 and changing the extraction of the distillate from product column F outside the system to full recycling in the hydrogen reduction reactor, 90 parts of 1,3-butanediol product (distillation rate 10 wt%) were obtained from the bottom of product column F by the same method as in Example 1. The obtained 1,3-butanediol product was subjected to GC analysis and GC-MS analysis. The results were as follows: the GC area ratio of 1,3-butanediol was 98.7%, 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 1,3-butanediol recovery rate of product column F was over 99%.

[0150] [Example 4]

[0151] Except for setting the reflux ratio of product column F to 10, 90 parts of 1,3-butanediol product were obtained from the bottom of product column F by the same method as in Example 3. The obtained 1,3-butanediol product was subjected to GC analysis and GC-MS analysis. The results were as follows: the GC area ratio of 1,3-butanediol was 98.8%, the acetaldehyde content was 0.8 ppm, and the crotonaldehyde content was 0.7 ppm. In addition, the potassium permanganate test value was 40 minutes. The 1,3-butanediol recovery rate of product column F was over 99%.

[0152] [Example 5]

[0153] Except for setting the reflux ratio of product column F to 20, 90 parts of 1,3-butanediol product were obtained from the bottom of product column F by the same method as in Example 3. The obtained 1,3-butanediol product was subjected to GC analysis and GC-MS analysis. The results were as follows: the GC area ratio of 1,3-butanediol was 98.8%, the acetaldehyde content was 0.5 ppm, and the crotonaldehyde content was 0.5 ppm. In addition, the potassium permanganate test value was 45 minutes. The 1,3-butanediol recovery rate of product column F was over 99%.

[0154] [Example 6]

[0155] Except for setting the reflux ratio of the product column F to 50, 90 parts of 1,3 - butanediol product were obtained from the bottom of the product column F by the same method as in Example 3. GC analysis and GC - MS analysis were performed on the obtained 1,3 - butanediol product. The results were as follows: the GC area ratio of 1,3 - butanediol was 98.8%, the acetaldehyde content was 0.2 ppm, and the crotonaldehyde content was 0.2 ppm. In addition, the potassium permanganate test value was 55 minutes. The recovery rate of 1,3 - butanediol in the product column F was over 99%.

[0156] [Example 7]

[0157] As the charging liquid flowing into the product column F, a liquid with a 1,3 - butanediol area ratio of 98%, an acetaldehyde content of 53 ppm, and a crotonaldehyde content of 41 ppm was used. Except for setting the reflux ratio of the product column F to 1, the top distillate amount to 1 part, and obtaining 99 parts of 1,3 - butanediol product (distillate rate 1 wt%) from the bottom of the product column F, the same operations as in Example 3 were carried out (all the distillate was recycled in the hydrogen reduction reactor). GC analysis and GC - MS analysis were performed on the obtained 1,3 - butanediol product. The results were as follows: the GC area ratio of 1,3 - butanediol was 98.6%, the acetaldehyde content was 1 ppm, and the crotonaldehyde content was 1 ppm. In addition, the potassium permanganate test value was 40 minutes. The recovery rate of 1,3 - butanediol in the product column F was over 99%.

[0158] [Example 8]

[0159] Except for setting the reflux ratio of the product column F to 5, the same operations as in Example 7 were carried out. GC analysis and GC - MS analysis were performed on the obtained 1,3 - butanediol product. The results were as follows: the GC area ratio of 1,3 - butanediol was 98.7%, the acetaldehyde content was 0.9 ppm, and the crotonaldehyde content was 0.8 ppm. In addition, the potassium permanganate test value was 45 minutes. The recovery rate of 1,3 - butanediol in the product column F was over 99%.

[0160] [Example 9]

[0161] Except for setting the reflux ratio of the product column F to 10, the same operations as in Example 7 were carried out. GC analysis and GC - MS analysis were performed on the obtained 1,3 - butanediol product. The results were as follows: the GC area ratio of 1,3 - butanediol was 98.7%, the acetaldehyde content was 0.5 ppm, and the crotonaldehyde content was 0.3 ppm. In addition, the potassium permanganate test value was 50 minutes. The recovery rate of 1,3 - butanediol in the product column F was over 99%.

[0162] [Example 10]

[0163] Except for setting the reflux ratio of the product column F to 100, the same operations as in Example 7 were carried out. GC analysis and GC-MS analysis were performed on the obtained 1,3-butanediol product. The results were as follows: the GC area ratio of 1,3-butanediol was 98.7%, the acetaldehyde content was less than 0.2 ppm, and the crotonaldehyde content was less than 0.1 ppm. In addition, the potassium permanganate test value was 60 minutes. The recovery rate of 1,3-butanediol in the product column F was over 99%.

[0164] [Example 11]

[0165] Except for setting the reflux ratio of the product column F to 500, the same operations as in Example 7 were carried out. GC analysis and GC-MS analysis were performed on the obtained 1,3-butanediol product. The results were as follows: the GC area ratio of 1,3-butanediol was 98.7%, the acetaldehyde content was less than 0.2 ppm, and the crotonaldehyde content was less than 0.1 ppm. In addition, the potassium permanganate test value was 65 minutes. The recovery rate of 1,3-butanediol in the product column F was over 99%.

[0166] [Example 12]

[0167] As the charging liquid flowing into the product column F, a liquid with a 1,3-butanediol area ratio of 99%, an acetaldehyde content of 5 ppm, and a crotonaldehyde content of 2 ppm was used. Except for setting the reflux ratio of the product column F to 10, the overhead distillate amount to 0.3 parts, and obtaining 99.7 parts of 1,3-butanediol product (distillation rate 0.3 wt%) from the bottom of the product column F, the same operations as in Example 3 were carried out (all the distillate was recycled in the hydrogen reduction reactor). GC analysis and GC-MS analysis were performed on the obtained 1,3-butanediol product. The results were as follows: the GC area ratio of 1,3-butanediol was 99.2%, the acetaldehyde content was 0.3 ppm, and the crotonaldehyde content was 0.2 ppm. In addition, the potassium permanganate test value was 55 minutes. The recovery rate of 1,3-butanediol in the product column F was over 99%.

[0168] [Example 13]

[0169] Except for setting the overhead distillate amount to 5 parts and obtaining 95 parts of 1,3-butanediol product (distillation rate 5 wt%) from the bottom of the product column F, the same operations as in Example 12 were carried out (all the distillate was recycled in the hydrogen reduction reactor). GC analysis and GC-MS analysis were performed on the obtained 1,3-butanediol product. The results were as follows: the GC area ratio of 1,3-butanediol was 99.5%, the acetaldehyde content was less than 0.2 ppm, and the crotonaldehyde content was less than 0.1 ppm. In addition, the potassium permanganate test value was 60 minutes. The recovery rate of 1,3-butanediol in the product column F was over 99%.

[0170] [Example 14]

[0171] Except for changing the recycling end of the distillate of the product column F from the hydrogen reduction reactor to the butyraldehyde manufacturing process, the same operations as in Example 3 were carried out. As a result, the quality of the obtained 1,3-butanediol product and the 1,3-butanediol recovery rate of the product column F were exactly the same as those in Example 3.

[0172] [Example 15]

[0173] An example where the acetaldehyde content and crotonaldehyde content in the product column feed liquid are relatively high (when the hydrogen feed amount in the hydrogenation process is small and the reflux in the alcohol removal process is small). The reflux ratio of the product column F was set to 10, the overhead distillate amount was set to 10 parts, and 90 parts of 1,3-butanediol product (distillation rate 10% by weight) was obtained from the bottom of the product column F. GC analysis and GC-MS analysis were performed on the obtained 1,3-butanediol product. The results were as follows: the GC area ratio of 1,3-butanediol was 99.4%, the acetaldehyde content was 1.2 ppm, and the crotonaldehyde content was 1.1 ppm. In addition, the potassium permanganate test value was 35 minutes. The 1,3-butanediol recovery rate of the product column F was over 99%.

[0174] [Comparative Example 1]

[0175] Except for setting the reflux ratio of the product column F to 0.05 and obtaining 80 parts of 1,3-butanediol product (distillation rate 20% by weight) from the bottom of the product column F, the same operations as in Example 1 were carried out. GC analysis and GC-MS analysis were performed on the obtained 1,3-butanediol product. The results were as follows: the GC area ratio of 1,3-butanediol was 98.5%, the acetaldehyde content was 6 ppm, and the crotonaldehyde content was 5 ppm. In addition, the potassium permanganate test value was 0 minutes. The 1,3-butanediol recovery rate of the product column F was 82%.

[0176] [Comparative Example 2]

[0177] Except for setting the reflux ratio of the product column F to 0.1 and obtaining 80 parts of 1,3-butanediol product (distillation rate 20% by weight) from the bottom of the product column F, the same operations as in Example 1 were carried out. GC analysis and GC-MS analysis were performed on the obtained 1,3-butanediol product. The results were as follows: the GC area ratio of 1,3-butanediol was 98.6%, 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 column F was 82%.

[0178] [Reference Example 1]

[0179] Except that the reflux ratio of the product column F was set to 0.1 and 70 parts of 1,3 - butanediol product (distillation rate 30 wt%) was obtained from the bottom of the product column F, the same operations as in Example 1 were carried out. The obtained 1,3 - butanediol product was subjected to GC analysis and GC - MS analysis. The results were as follows: the GC area ratio of 1,3 - butanediol was 98.7%, 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 column F was 72%.

[0180] [Gas Chromatography Analysis]

[0181] 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 13 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.

[0182] (Conditions for Gas Chromatography Analysis)

[0183] Analysis device: Shimadzu GC2010.

[0184] 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)

[0185] 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.

[0186] Sample introduction and temperature: Split sample introduction method, 250°C.

[0187] Gas flow rate of the split and carrier gas: 23 mL / min, helium.

[0188] Gas flow rate of the column and carrier gas: 1 mL / min, helium.

[0189] Detector and temperature: Flame ionization detector (FID), 280°C.

[0190] Injected sample: 0.2 μL of an 80 wt% aqueous solution of 1,3 - butanediol product.

[0191] [GC - MS Analysis]

[0192] Analytical apparatus: Agilent 6890A-GC / 5973A-MSD

[0193] Analytical column: Column with polydimethylsiloxane as the stationary phase (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0194] Temperature rising conditions: After rising from 80 °C to 120 °C at 5 °C / minute, then rising to 160 °C at 2 °C / minute and holding for 2 minutes. Further, rising to 230 °C at 10 °C / minute and holding at 230 °C for 18 minutes.

[0195] Sample introduction temperature: 250 °C.

[0196] Carrier gas: Helium.

[0197] Gas flow rate of the column: 1 mL / minute.

[0198] Ion source temperature: EI 230 °C, CI 250 °C

[0199] Quadrupole temperature: 150 °C

[0200] Sample: Directly used for analysis

[0201] [Potassium permanganate test]

[0202] In this specification, the potassium permanganate test value (PMT) is the value measured in sequence by the visual colorimetric method based on JIS K1351 (1993).

[0203] [Research results]

[0204] The results of the above comparative examples and examples are shown in Table 1 and Table 2.

[0205] [Table 1]

[0206]

[0207] [Table 2]

[0208]

[0209]

[0210] As can be seen from Comparative Examples 1 and 2, when the distillate rate is 20% by weight, even if the reflux ratio is 0.1, the removal effects of acetaldehyde (AD) and crotonaldehyde (CR) are relatively low, and the potassium permanganate test value (PMT) of the product cannot reach a satisfactory value. If the distillate rate is set to 30% by weight (Reference Example 1), in the case of a reflux ratio of 0.1, although the PMT meets the requirement for 30 minutes, the recovery rate of 1,3BG in the product column is 72%, which is very poor, so it is economically disadvantageous.

[0211] As can be seen from Comparative Examples 1-2, Reference Example 1, and Example 1, when the reflux ratio of the product column is changed from 0.1 to 0.3, the removal amounts of AD and CR in the distillate of the product column increase at a distillate rate of 10% by weight (recovery rate: 92%). Therefore, the concentrations of AD and CR in the product decrease, and as a result, the PMT of the product column effluent (product) is improved.

[0212] It can be seen that by controlling the feed liquid composition (especially AD and CR), the reflux ratio, and the distillate amount, even at a relatively low reflux ratio, the quality can be maintained at a certain recovery rate.

[0213] As can be seen from Examples 1 and 2, when the reflux ratio of the product column is changed from 0.3 to 1, the removal amounts of AD and CR in the distillate of the product column further increase. Therefore, the concentrations of AD and CR in the product decrease, and as a result, the PMT of the product column effluent (product) is further improved.

[0214] When comparing Example 2, Example 3, and Example 14, by recycling the distillate of the product column, almost the same product quality can be obtained when increasing the recovery rate of 1,3BG. This is because in Example 3, AD and CR contained in the distillate of the product column are hydrogenated in the hydrogen reduction reactor. In addition, this is because in Example 14, AD and CR contained in the distillate of the product column are dimerized in the butyraldehyde manufacturing process.

[0215] As can be seen from Examples 3-6, when the reflux ratio of the product column is increased, the concentrations of AD and CR in the product are further reduced, and the PMT quality is improved.

[0216] As can be seen from Examples 7-11, when the purity of the feed liquid of the product column is increased and the concentrations of AD and CR are reduced, even if the reflux ratio of the product column is decreased and the distillate amount is reduced, the product quality can be improved. In addition, as can be seen from Examples 7-11, when the reflux ratio is increased, although the product quality is improved, if the reflux ratio is increased to 500, the improvement of the product quality slows down, and only the effect of the energy increase caused by the increase in the reflux amount is reduced.

[0217] As can be seen from Examples 4, 9, and 12, when the reflux amount is constant, even if the distillate amount and the purity of the feed liquid are changed, the product quality can be maintained. Although the recycling amount of the distillate depends on the concentrations of AD and CR in the feed liquid, even if it is too low, there is a limit because the removal amounts of AD and CR decrease extremely. However, if it is about 0.1% by weight, the quality can be maintained. The less the recycling amount of the distillate, the lower the increase in the equipment size due to the increase in the processing amount through recycling in the previous process. Therefore, it is best to be as little as possible, and it is best to consider the overall balance in consideration of the quality, etc., and determine the optimal value.

[0218] As can be seen from Example 15, even if the contents of AD and CR in the charging liquid of the product column are relatively high to a certain extent, if the reflux amount and distillate amount obtained from the product column are large, the product quality can be maintained.

[0219] It should be noted that among the 1,3 - butanediol products obtained by the existing methods, there is no product with such a long time of potassium permanganate test value (PMT) as shown in the present disclosure.

[0220] As a summary of the above, the constitution and its variations of the present disclosure are noted below.

[0221] [1] A method for manufacturing 1,3 - butanediol for obtaining purified 1,3 - butanediol from a crude reaction liquid containing 1,3 - butanediol, comprising: a dehydration step of removing water by distillation; a high - boiling - component removal step of removing high - boiling components by distillation; and a product distillation step for obtaining purified 1,3 - butanediol. In the product column used in the product distillation step, a charging liquid with a 1,3 - butanediol concentration of 97% or more (or 98% or more, or 99% or more), an acetaldehyde content of 500 ppm or less (or 200 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 (or 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 (or 0.15 or more), an acetaldehyde and crotonaldehyde concentrate is distilled out from above the charging layer, and 1,3 - butanediol is extracted from below the charging layer.

[0222] [2] The method for manufacturing 1,3 - butanediol according to [1] above, wherein the crude reaction liquid containing the 1,3 - butanediol is a crude reaction liquid obtained by hydrogen reduction of aldol (or a crude reaction liquid obtained by hydrolysis of 1,3 - epoxybutane, a crude reaction liquid obtained by selective hydrocracking of erythritol, a crude reaction liquid obtained by selective hydro - addition of butadiene, a crude reaction liquid obtained by hydrogenation of n - butyraldehyde - 3 - ketone, a crude reaction liquid obtained by hydrogenation of 1 - butanol - 3 - ketone, a crude reaction liquid obtained by hydrogenation of 3 - hydroxy - 1 - butyric acid, a crude reaction liquid obtained by hydrogenation of β - butyrolactone, or a crude reaction liquid obtained by hydrogenation of diketene).

[0223] [3]In the method for manufacturing 1,3 - butanediol according to [2] above, in the reduction (hydrogenation) of the aldol - type compounds, the aldol - type compounds used as raw materials are aldol, dimeric m - hydroxybutyraldehyde which is its cyclic dimer, 2,6 - dimethyl - 1,3 - dioxane - 4 - ol which is the cyclic trimer of acetaldehyde, and any mixture thereof.

[0224] [4]In the method for manufacturing 1,3 - butanediol according to [2] or [3] above, after the crude reaction liquid containing the aldol - type compounds is subjected to crude evaporation, distillation, or hydrogenation to remove aldehydes, a hydrogenation step is carried out.

[0225] [5]In the method for manufacturing 1,3 - butanediol according to any one of [2] to [4] above, in the reduction (hydrogenation) of the aldol - type compounds, the content of the aldol - type compounds used as raw materials is 30% by weight or more (for example, 30 - 99% by weight) (alternatively, 40% by weight or more (for example, 40 - 98% by weight), 50% by weight or more (for example, 50 - 97% by weight), 60% by weight or more (for example, 60 - 95% by weight), 65 - 90% by weight, 70 - 90% by weight, or 75 - 90% by weight).

[0226] [6]In the method for manufacturing 1,3 - butanediol according to any one of [2] to [5] above, the reduction (hydrogenation) raw material of the aldol - type compounds contains water, and the water content is 2% by weight or more (alternatively, 5% by weight or more, 10% by weight or more, or 15% by weight or more), and the upper limit value of the water content is 90% by weight (alternatively, 80% by weight, 70% by weight, 60% by weight, 50% by weight, 40% by weight, 30% by weight, or 20% by weight).

[0227] [7]In the method for manufacturing 1,3 - butanediol according to any one of [2] to [6] above, with respect to 100 parts by weight of the hydrogenation raw material, the amount of the hydrogenation catalyst for the reduction (hydrogenation) of the aldol - type compounds is 1 - 30 parts by weight (alternatively, 4 - 25 parts by weight, 8 - 20 parts by weight, or 12 - 18 parts by weight).

[0228] [8]In the method for manufacturing 1,3 - butanediol according to any one of [2] to [7] above, with respect to 100 parts by mass of the hydrogenation raw material, the amount of hydrogen used in the reduction (hydrogenation) reaction of the aldol - type compounds is 0.5 - 40 parts by weight (alternatively, 1 - 30 parts by weight, 4 - 20 parts by weight, or 8 - 12 parts by weight).

[0229] [9]In the method for manufacturing 1,3 - butanediol according to any one of [2] to [8] above, the pressure (total pressure; gauge pressure) in the reaction system during the reduction (hydrogenation) reaction of the aldol - type compounds is 9 MPa - 70 MPa (alternatively, 10 MPa - 40 MPa).

[0230]

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

[0231]

[11] According to the method for manufacturing 1,3 - butanediol described in any one of [2] to

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

[0232]

[12] According to the method for manufacturing 1,3 - butanediol described in any one of [2] to

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

[0233]

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

[12] , it further includes a de - alcoholization step of removing low - boilers containing alcohols in the process stream containing the 1,3 - butanediol.

[0234]

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

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

[0235]

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

[14] , the extraction rate (%) in the desalting step [(amount of desalted product taken out from the desalting tower (parts) / amount of feed to the desalting tower (parts)·100] is 0.1 to 40% by weight (alternatively, 1 to 35% by weight, 2 to 30% by weight, 3 to 25% by weight, 5 to 20% by weight, or 7 to 15% by weight).

[0236]

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

[15] , the high - boiler removal tower used in the high - boiler removal step is a packed tower (alternatively, a perforated plate tower or a bubble - cap tower), and the reboiler used is a natural falling - film evaporator or a scraping - agitation thin - film evaporator.

[0237]

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

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

[0238]

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

[16] or

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

[0239]

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

[16] to

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

[0240]

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

[16] to

[19] , at least a part of the withdrawn liquid from the high - boiling - point removal tower is recycled in the process before the high - boiling - point removal step.

[0241]

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

[16] to

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

[0242]

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

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

[0243]

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

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

[0244]

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

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

[0245]

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

[23] or

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

[0246]

[26] In the method for manufacturing 1,3 - butanediol according to

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

[0247]

[27] In the method for manufacturing 1,3 - butanediol according to any one of

[23] to

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

[0248]

[28] In the method for manufacturing 1,3 - butanediol according to any one of

[23] to

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

[0249]

[29] In the method for manufacturing 1,3 - butanediol according to any one of [1] to

[28] above, the product column is a packed column (alternatively, a perforated plate column or a bubble - cap column), and the reboiler used is a natural falling - film evaporator or a scraping - agitated thin - film evaporator.

[0250]

[30] In the method for manufacturing 1,3 - butanediol according to any one of [1] to

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

[0251]

[31] In the method for manufacturing 1,3 - butanediol according to any one of [1] to

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

[0252]

[32] In the method for manufacturing 1,3 - butanediol according to any one of [1] to

[31] above, the reflux ratio in the product column is 0.2 or more (alternatively, 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, 11 or more, 12 or more, 13 or more, 14 or more, 15 or more, 16 or more, 17 or more, 18 or more, 19 or more, 20 or more, 25 or more, 30 or more, 35 or more, 40 or more, 50 or more, 400 or more or 500 or more).

[0253]

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

[32] above, the acetaldehyde content in the charging liquid flowing into the product column is 205 ppm or less (alternatively, 200 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).

[0254]

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

[33] above, the crotonaldehyde content in the charging liquid flowing into the product column 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).

[0255]

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

[34] above, the distillate rate in the product column is less than 20% by weight (alternatively, 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, 0.4% by weight or less, or 0.2% by weight or less).

[0256]

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

[35] above, 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.

[0257]

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

[36] above, 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 its upstream process.

[0258]

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

[36] or

[37] above, within the range of not exceeding the distillate amount in the product column, with respect to the charging amount flowing into the product column, the recycling amount of the distillate from the product column in the process before the product distillation process is less than 30% by weight (alternatively, 90% by weight or less, 80% by weight or less, 70% by weight or less, 60% by weight or less, 50% by weight or less, 40% by weight or less, or 30% by weight or less).

[0259]

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

[36] to

[38] , the recycling amount of the pre - process before the product distillation step of the product tower distillate is 0.01 wt% or more (alternatively, 0.05 wt% or more, 0.1 wt% or more, 0.5 wt% or more, 1 wt% or more, 1.5 wt% or more, 2 wt% or more, 3 wt% or more, 4 wt% or more, 5 wt% or more, 7 wt% or more, 10 wt% or more, or 20 wt% or more) relative to the charging amount of the product tower.

[0260]

[40] A 1,3 - butanediol product having a potassium permanganate test value exceeding 10 minutes (alternatively, 5 minutes or more, 30 minutes or more, 40 minutes or more, 50 minutes or more, or 60 minutes or more).

[0261]

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

[40] , in the gas chromatography analysis under the following conditions, the peak area ratio of 1,3 - butanediol is higher than 98.5% (alternatively, 98.6% or more, 98.7% or more, 98.8% or more, 98.9% or more, 99% or more, 99.1% or more, 99.2% or more, 99.3% or more, 99.5% or more, or 99.8% or more).

[0262] (Conditions for gas chromatography analysis)

[0263] Analysis column: A column with a stationary phase of polydimethylsiloxane (film thickness 1.0 μm × length 30 m × inner diameter 0.25 mm).

[0264] 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.

[0265] Sample introduction temperature: 250°C.

[0266] Carrier gas: Helium.

[0267] Gas flow rate of the column: 1 mL / min.

[0268] Detector and detection temperature: Flame ionization detector (FID), 280°C.

[42]

[0270] According to the 1,3 - butanediol product described in

[40] or

[41] , the acetaldehyde content is 2 ppm or less (alternatively, 1.7 ppm or less, 1.5 ppm or less, 1.2 ppm or less, 1.0 ppm or less, 0.7 ppm or less, 0.5 ppm or less, 0.3 ppm or less, or 0.2 ppm or less).

[0271]

[43] For the 1,3 - butanediol product according to any one of

[40] to

[42] , the crotonaldehyde content is 1.2 ppm or less (alternatively, 1.0 ppm or less, 0.7 ppm or less, 0.5 ppm or less, 0.3 ppm or less, 0.2 ppm or less, or 0.1 ppm or less).

[0272]

[44] A humectant comprising the 1,3 - butanediol product according to any one of

[40] to

[43] .

[0273]

[45] For the humectant according to

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

[0274]

[46] A cosmetic comprising the humectant according to

[44] or

[45] .

[0275]

[47] For the cosmetic according to

[46] , the blending amount of the 1,3 - butanediol product 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).

[0276] Industrial availability

[0277] The 1,3 - butanediol product of the present disclosure has a high potassium permanganate test value, is suitable as a humectant, and is also suitable as a raw material for cosmetics. This 1,3 - butanediol product has excellent moisture - retaining performance and can be used as a raw material for humectants and cosmetics that can maintain high quality for a long time.

[0278] Explanation of reference numerals

[0279] A: Dehydration tower

[0280] B: Desalting tower

[0281] C: High - boiling - point substance removal distillation tower (high - boiling tower)

[0282] D: Alkali reactor

[0283] E: Alkali removal tower

[0284] F: Product distillation tower (product tower)

[0285] A - 1, B - 1, C - 1, E - 1, F - 1: Condenser

[0286] A - 2, C - 2, F - 2: Reboiler

[0287] X - 1: Crude 1,3 - butanediol

[0288] X-2: Water (drainage)

[0289] X-3: Part of salt, high-boiling substances, and 1,3-butanediol

[0290] X-4: Part of high-boiling substances and 1,3-butanediol

[0291] X-5: Caustic soda, part of high-boiling substances, and 1,3-butanediol

[0292] X-6: Part of low-boiling substances and 1,3-butanediol

[0293] Y: 1,3-butanediol product

Claims

1. A method for manufacturing 1,3 - butanediol for obtaining purified 1,3 - butanediol from a crude reaction liquid containing 1,3 - butanediol, comprising: A dehydration step of removing water by distillation; a high - boiling component removal step of removing high - boiling components by distillation; and a product distillation step for obtaining purified 1,3 - butanediol. In the product column used in the product distillation step, a feed liquid with a 1,3 - butanediol concentration of 97% or more, 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 is 3 or more. An acetaldehyde and crotonaldehyde 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 product column is 205 ppm or less.

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

8. The method for manufacturing 1,3 - butanediol according to claim 1 or 2, wherein the distillate rate in the product column is less than 20% by weight.

9. 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.

10. The method for manufacturing 1,3 - butanediol according to claim 1 or 2, in the steps before the product distillation step, namely the dehydration step, the dealcoholization step or the steps before these steps, at least a part of the distillate of the product column is recycled.

11. The method for manufacturing 1,3 - butanediol according to claim 10, wherein the crude reaction liquid containing 1,3 - butanediol is a crude reaction liquid obtained by hydrogen reduction of aldol, and at least a part of the distillate of the product column is recycled in the hydrogen reduction step of aldol or its upstream steps.

12. The method for manufacturing 1,3 - butanediol according to claim 10, within the range of the distillate amount in the product column, the recycling amount of the distillate of the product column in the steps before the product distillation step is less than 30% by weight relative to the feed amount flowing into the product column.

13. The method for manufacturing 1,3-butanediol according to claim 10, wherein, within the range of the distillate amount in the product column, the recycling amount of the product in the process before the product distillation process of the product column distillate is 0.01% by weight or more relative to the charging amount flowing into the product column.

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