US20230098112A1

US20230098112A1 - 1,3-butylene glycol product and method for producing 1,3-butylene glycol

Info

Publication number: US20230098112A1
Application number: US17/789,067
Authority: US
Inventors: Masahiko Shimizu; Yasuteru Kajikawa; Yuuichirou HIRAI; Keisuke Ono; Midori UMEHARA; Yuki TESHIMA; Tetsuro NAKANISHI
Original assignee: Daicel Corp
Current assignee: Daicel Corp
Priority date: 2019-12-28
Filing date: 2020-12-23
Publication date: 2023-03-30
Also published as: WO2021132369A1; KR20220119719A; EP4083005A1; WO2021132342A1; CN114901244A; JPWO2021132342A1; EP4083009A4; EP4083009A1; EP4083007A1; EP4083003A4; WO2021132361A1; EP4083003A1; US20230033469A1; CN114901623A; EP4083008A1; KR20220119714A; EP4083010A4; WO2021132360A1; CN114901243A; WO2021132354A1

Abstract

A high-purity 1,3-butylene glycol product is provided, which is colorless and odorless (or almost colorless and odorless), unlikely to cause coloration and odor over time, and, besides, unlikely to cause an acid concentration increase over time also in a state containing water. A 1,3-butylene glycol product in which at least one of a content of methyl vinyl ketone, a content of acetone, a content of butylaldehyde, a content of acetaldol, a content of a compound represented by Formula (1) below, a content of a compound represented by Formula (2) below, a content of a compound represented by Formula (3) below, and a total content of a compound represented by Formula (4) below and a compound represented by Formula (5) below, is less than 8 ppm.

Description

TECHNICAL FIELD

The present disclosure relates to a method for producing 1,3-butylene glycol, and a 1,3-butylene glycol product. The present application claims priority from the Japanese Patent Application No. 2019-239974. Japanese Patent Application No. 2019-239975, Japanese Patent Application No. 2019-239976, Japanese Patent Application No. 2019-239977, Japanese Patent Application No. 2019-239978, and Japanese Patent Application No. 2019-239979, all filed in Japan on Dec. 28, 2019, the Japanese Patent Application No. 2020-006660 filed in Japan on Jan. 20, 2020, and the Japanese Patent Application No. 2020-018910 filed in Japan on Feb. 6, 2020, the entire contents of which are incorporated herein by reference.

BACKGROUND ART

1,3-Butylene glycol is a colorless, transparent, and odorless liquid and has properties, such as low volatility, low toxicity, and high hygroscopicity, and has excellent chemical stability, 1,3-butylene glycol has a wide range of applications, including raw materials for various synthetic resins and surfactants, as well as materials for cosmetics, hygroscopic agents, high boiling point solvents, and antifreezes, etc. Particularly in recent years, 1,3-butylene glycol has been attracting attention for having excellent properties as a moisturizer, and demand is growing in the cosmetic industry.
1,3-Butylene glycol produced by a known production method has had a problem of acid concentration (acidity) increase when the 1,3-butylene glycol is left for a long period of time in a state containing water. The cause of the acid concentration increase has been uncertain but thought to be related to by-products contained in crude 1,3-butylene glycol. Cosmetics typically contain water and require a long period of time from production to actual use by general consumers. In addition, from the viewpoint, such as storage stability of cosmetics, liquidity is strictly controlled. When 1,3-butylene glycol produced by a known method is used in cosmetics, an acid concentration increase can disrupt the liquidity balance of the cosmetics, and this can lead to a loss of the intended effect. In addition, the acid concentration increase of cosmetics can cause rough skin or the like of the users. Furthermore, there was a case where cosmetics containing no water also have absorbed water during use or storage, and this has also increased the acid concentration accordingly. Thus, removing by-products from crude 1,3-butylene glycol to yield high-purity 1,3-butylene glycol has been required.
Also, 1,3-butylene glycol produced by a known production method have sometimes had an odor due to effects from by-products. In addition, 1,3-butylene glycol transparent immediately after production may be colored over time, which is a problem in storing for a long period of time. For example, during use and/or storage after use of a cosmetic, the cosmetic is exposed to air. In addition, in production of cosmetics, the production is usually performed in air atmosphere, and the product may be heated for the purposes of, for example, sterilization. When 1,3-butylene glycol produced by a known method is used in cosmetics, sometimes coloration occurs due to the presence of air or effects of heating. To solve such problems, removing by-products from crude 1,3-butylene glycol to yield high-purity 1,3-butylene glycol has been required.
For a method to produce high-purity 1,3-butylene glycol, a method including adding sodium hydroxide to crude 1,3-butylene glycol produced by hydrogen reduction of acetaldols and performing distillation has been proposed. In addition, other methods have been proposed, including a method in which an alkali metal base is added to crude 1,3-butylene glycol from which a high boiling point substance has been removed, the mixture is heat-treated, then 1,3-butylene glycol is distilled, and the alkali metal compound and a high boiling point substance are separated as residues, and subsequently a low boiling point substance is distilled off from the 1,3-butylene glycol distillate (Patent Documents 1 to 6). Various methods for purifying 1,3-butylene glycol have been thus proposed to produce high-purity 1,3-butylene glycol.

CITATION LIST

Patent Document

Patent Document 1: JP 07-258129 A
Patent Document 2: WO 00/07969
Patent Document 3: JP 2001-213822 A
Patent Document 4: JP 2001-213824 A
Patent Document 5: JP 2001-213825 A
Patent Document 6: JP 2001-213828 A

SUMMARY OF INVENTION

Technical Problem

However, 1,3-butylene glycol products produced from these purification methods still contain by-products and have a problem of having an odor, a problem of increasing acid concentration over time when containing water, and a problem that coloration occurs over time.
1,3-Butylene glycol is produced, for example, by a method of (1) reduction (hydrogenation) of acetaldols, (2) hydrolysis of 1,3-butylene oxide, (3) selective hydrocracking of erythritol, (4) selective hydration of butadiene, (5) hydrogen addition to n-butanol-3-one, (6) hydrogen addition to 1-butanol-3-one, (7) hydrogen addition to 3-hydroxy-1-butanoic acid, (8) hydrogen addition to β-butyrolactone, or (9) hydrogen addition to diketene.
Of the production methods, the method of (1) reduction (hydrogenation) of acetaldols to yield 1,3 butylene glycol is preferable. Among them, the method of reduction of acetaldols in a liquid phase is preferable in terms of yield. The reasons for this are that acetaldols have a high boiling point, that acetaldols are unstable to heat and readily undergo a dehydration reaction at high temperatures to form crotonaldehyde or the like, and furthermore, that a reaction rate of the dehydration reaction is greater than that of the reduction reaction (hydrogenation reaction) at high temperatures. That is, when acetaldols are subjected to vapor-phase reduction, the temperature inside the reaction system needs to be increased to high temperature, but subjecting the acetaldols to high temperature causes a dehydration reaction to produce crotonaldehyde or the like, and the subsequent reduction reaction produces by-products, such as butanol. Thus, this results in relatively reduced yield of the target 1,3-butylene glycol. Thus, to produce a high-purity 1,3-butylene glycol product, a liquid phase reduction rather than a gas phase reduction is preferably performed.
In production of 1,3-butylene glycol, by-products are generally produced in the production process. For example, in production of 1,3-butylene glycol by hydrogen reduction of an acetaldol, a low boiling point substance (low boiling point compound) having an unsaturated bond, such as acetaldehyde, butylaldehyde, crotonaldehyde, acetone, and methyl vinyl ketone; a condensate of these (e.g., a trimer of acetaldehyde); a hydride of the above condensate; a condensate of 1,3-butylene glycol and the above low boiling point substance (e.g., an acetal of 1,3-butylene glycol and acetaldol); or the like is produced as a by-product. In addition, an acetal of crotonaldehyde and 1,3-butylene glycol; an acetal of acetaldehyde and 1,3-butylene glycol; an acetal of a hydride of a trimer of acetaldol, acetaldehyde, and acetaldehyde; or the like is produced as a by-product. Furthermore, in addition to the above, acetic acid may be present as an impurity in an acetaldol used as a raw material or is used to neutralize sodium hydroxide used in producing an acetaldol, and a condensate of the acetic acid and 1,3-butylene glycol (ester of acetic acid and 1,3-butylene glycol) is formed as a by-product. Moreover, these by-products may have properties as a substance that causes coloration, a substance that causes odor or a substance that causes acidity.
Whether the acetal is a substance that causes coloration, a substance that causes odor or a substance that causes acidity is uncertain, and the acetal is also considered to have all the properties but is considered to have strong properties as a substance that causes odor. Specifically, the acetal itself is unlikely to be a substance that causes odor but can form a substance that causes odor by a change over time or heating. Furthermore, the acetal may be hydrolyzed to form acetaldol, which is a substance that causes odor and has an oxidation (coloration) promoting effect. Thus, the acetal can also be said to be a substance that causes coloration. Here, the substance that causes coloration is defined as including not only a substance actually having a hue itself but also a substance changing over time into a substance having a hue. The substance that causes odor is defined as including not only a substance actually emitting an odor itself but also a substance changing over time into a substance emitting an odor. The substance that causes acidity is defined as a substance increasing acid concentration over time when containing water.
Whether the ester is a substance that causes coloration, a substance that causes odor or a substance that causes acidity is uncertain, and the ester is also considered to have all the properties but is considered to have strong properties as both a substance that causes odor and a substance that causes acidity. This is because when the ester is hydrolyzed by water, acetic acid is produced.
In production of 1,3-butylene glycol, it is considered that by-products in the production process may include, in addition to the acetal and ester, a wide variety of by-products corresponding to a substance that causes coloration, a substance that causes odor, or a substance that causes acidity. For example, the hydride of a trimer of acetaldehyde described above is considered to possibly correspond to any of a substance that causes coloration, a substance that causes odor or a substance that causes acidity.
The by-products described above are difficult to completely remove even using a purification means, such as distillation known in the art. This is considered to be because crude 1,3-butylene glycol is subjected to high temperature conditions and alkali treatment in the purification stage of the crude 1,3-butylene glycol, and new by-products are produced accordingly. For these reasons, as described above, the 1,3-butylene glycol products of Patent Documents 1 to 6 contain a wide variety of by-products, thus have an odor and are colored over time, and furthermore, increase acid concentration over time in a state containing water.
Thus, an object of the present disclosure is to provide a high-purity 1,3-butylene glycol product that is colorless and odorless (or almost colorless and odorless), unlikely to cause coloration and odor over time, and, besides, unlikely to cause an acid concentration increase over time also in a state containing water.
Furthermore, another object of the present disclosure is to provide a moisturizer and a cosmetic product that have excellent moisturizing performance and can retain high quality for a long period of time.
Further, another object of the present disclosure is to provide a method for industrially efficiently producing high-purity 1,3-butylene glycol having properties of being colorless and odorless (or almost colorless and odorless), unlikely to cause coloration over time, and, besides, unlikely to cause an acid concentration increase over time also in a state containing water.

Solution to Problem

As a result of diligent research to achieve the above purposes, the inventors of the present disclosure have found that specific nine compounds and, further, acetaldehyde and crotonaldehyde are substances that cause coloration, odor, an increase in coloration over time, an increase in odor over time, and an acid concentration increase. Then, the inventors have found a method for suppressing mixing of these compounds into a 1,3-butylene glycol product. More specifically, the inventors have found that, by adjusting contents of specific impurities and a concentration of 1,3-butylene glycol in charged liquids into a product column and a high boiling point component removal column and, further, by adjusting reaction conditions (particularly, increasing a partial pressure of hydrogen in a reactor) in a reaction step (e.g., hydrogenation of an acetaldol), it is possible to produce 1,3-butylene glycol having the properties of being colorless and odorless (or almost colorless and odorless), unlikely to cause coloration and odor over time, and, besides, unlikely to cause an acid concentration increase over time also in a state containing water. The present disclosure has been completed by further studying based on these findings.
That is, the present disclosure provides a 1,3-butylene glycol product in which at least one of eight contents: a content of methyl vinyl ketone, a content of acetone, a content of butylaldehyde, a content of acetaldol, a content of a compound represented by Formula (1) below, a content of a compound represented by Formula (2) below, a content of a compound represented by Formula (3) below, and a total content of a compound represented by Formula (4) below and a compound represented by Formula (5) below, is less than 8 ppm.
In the 1,3-butylene glycol product, a sum of the content of methyl vinyl ketone, the content of acetone, the content of butylaldehyde, the content of acetaldol, the content of the compound represented by Formula (1), the content of the compound represented by Formula (2), the content of the compound represented by Formula (3), the content of the compound represented by Formula (4), and the compound represented by Formula (5), may be less than 71 ppm.
In the 1,3-butylene glycol product, at least the content of acetaldol is preferably less than 8 ppm.
In the 1,3-butylene glycol product, at least the content of the compound represented by Formula (3) is preferably less than 8 ppm.
In the 1,3-butylene glycol product, a total content of methyl vinyl ketone, acetone, and butylaldehyde is preferably 24 ppm or less.
In the 1,3-butylene glycol product, a total content of the compound represented by Formula (1), the compound represented by Formula (2), the compound represented by Formula (4), and the compound represented by Formula (5) is preferably 24 ppm or less.
In the 1,3-butylene glycol product, a content of acetaldehyde is preferably less than 4 ppm and a content of crotonaldehyde is preferably less than 2 ppm.
In the 1,3-butylene glycol product, an acid concentration is preferably less than 11 ppm in terms of acetic acid, and, after a 90 wt. % aqueous solution has been kept at 100° C. for 1 week, an acid concentration is preferably less than 23 ppm in terms of acetic acid.
In the 1,3-butylene glycol product, an APHA is preferably 6 or less, and, after the 1,3-butylene glycol product has been kept at 180° C. for 3 hours in air atmosphere, an APHA is 78 or less.
Further, in the 1,3-butylene glycol product, an initial boiling point is preferably higher than 203° C. and/or a dry point is preferably 209° C. or lower.
In the 1,3-butylene glycol product, a potassium permanganate test value is preferably 30 minutes or longer.
In addition, the present disclosure provides a moisturizer containing the 1,3-butylene glycol product.
Furthermore, the present disclosure provides a cosmetic product containing the moisturizer.
The present disclosure further provides a method for producing 1,3-butylene glycol to yield purified 1,3-butylene glycol from a reaction crude liquid containing 1,3-butylene glycol,
the method (hereinafter sometimes referred to as “producing method 1 of the present disclosure”) including: performing dehydration including removing water by distillation, removing a high boiling point component including removing a high boiling point component by distillation, and performing product distillation to yield purified 1,3-butylene glycol,
wherein, in a product column for use in the product distillation, a 1,3-butylene glycol charged liquid is subjected to distillation under a condition that a reflux ratio is 0.3 or greater, the 1,3-butylene glycol charged liquid having a content of acetaldehyde of 500 ppm or less, a content of crotonaldehyde of 200 ppm or less, a content of water of 0.7 wt. % or less, and a concentration of 1,3-butylene glycol of 97.6 area %, according to a gas chromatographic analysis performed under conditions set forth below.
The conditions for the gas chromatographic analysis are as follows:
Analytical Column: a column with dimethylpolysiloxane as a stationary phase, having a length of 30 m, an inner diameter of 0.25 mm, and a film thickness of 1.0 μm
Heating conditions: heating from 80° C. to 120° C. at CI/min. then heating again to 160° C. at 2° C./min and maintaining for 2 minutes, and further heating to 230° C. at 10° C./min and maintaining at 230° C. for 18 minutes
Sample Introduction Temperature: 250° C.
Carrier Gas: helium
Column Gas Flow Rate: 1 mL/min
Detector and Detection Temperature: a flame ionization detector (FID), 280° C.
In the method for producing 1,3-butylene glycol, at least a portion of a distillate of the product column may be recycled to a step before the performing product distillation, the step including dehydration, dealcoholization, low boiling point component removal, or a step before these steps.
The present disclosure also provides a method for producing 1,3-butylene glycol to yield purified 1,3-butylene glycol from a reaction crude liquid containing 1,3-butylene glycol,
the method (hereinafter sometimes referred to as “producing method 2 of the present disclosure”) including: performing dehydration including removing water by distillation and removing a high boiling point component including removing a high boiling point component by distillation,
wherein, in a high boiling point component removal column for use in the removing a high boiling point component, a charged liquid containing 1,3-butylene glycol is subjected to distillation under a condition that a reflux ratio is 0.03 or greater, the charged liquid having a content of acetaldehyde of 500 ppm or less, a content of crotonaldehyde of 200 ppm or less, a content of water of 3 wt. % or less, and a concentration of 1,3-butylene glycol of 96.7 area % or greater, according to a gas chromatographic analysis performed under conditions set forth below.
The conditions for the gas chromatographic analysis are as follows:
Analytical Column: a column with dimethylpolysiloxane as a stationary phase, having a length of 30 m, an inner diameter of 0.25 mm, and a film thickness of 1.0 μm
Heating conditions: heating from 80° C. to 120° C. at 5° C./min then heating again to 160° C. at 2° C./min and maintaining for 2 minutes, and further heating to 230° C. at 10° C./min and maintaining at 230° C. for 18 minutes
Sample Introduction Temperature: 250° C.
Carrier Gas: helium
Column Gas Flow Rate; 1 mL/min
Detector and Detection Temperature: a flame ionization detector (FID), 280° C.
In each of the producing methods, the reaction crude liquid containing 1,3-butylene glycol may be a reaction crude liquid produced by hydrogen reduction of an acetaldol.
Each of the producing methods may further include at least one step selected from alkali treatment including treating a process stream containing 1,3-butylene glycol with a base, desalting including removing a salt in a process stream containing 1,3-butylene glycol, and dealcoholization including removing a low boiling point substance containing an alcohol in a process stream containing 1,3-butylene glycol.
In the present disclosure, “1,3-butylene glycol product” means a composition in which 1,3-butylene glycol occupies a majority of the components (e.g., a 1,3-butylene glycol content is 95 wt. % or greater, preferably 98 wt. % or greater).

Advantageous Effects of Invention

According to the present disclosure, a high-purity 1,3-butylene glycol product that is colorless and odorless (or almost colorless and odorless), unlikely to cause coloration and odor over time, and, besides, unlikely to cause an acid concentration increase over time also in a state containing water is provided.
Furthermore, the present disclosure provides a moisturizer and a cosmetic product that have excellent moisturizing performance and can retain high quality for a long period of time.
Further, the method for producing 1,3-butylene glycol of the present disclosure can be used to industrially efficiently produce high-purity 1,3-butylene glycol having properties of being colorless and odorless (or almost colorless and odorless), unlikely to cause coloration over time, and, besides, unlikely to cause an acid concentration increase over time also in a state containing water.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a flowchart illustrating a producing method (purification method) for a 1,3-butylene glycol product of the present disclosure.

FIG. 2 is a chromatogram showing a gas chromatographic analysis for a 1,3-butylene glycol product in Example 1.

FIG. 3 is a chromatogram showing a gas chromatographic analysis for a 1,3-butylene glycol product in Example 12.

FIG. 4 is a chromatogram showing a gas chromatographic analysis for a 1,3-butylene glycol product in Comparative Example 2.

DESCRIPTION OF EMBODIMENTS

1,3-Butylene Glycol Product

In the 1,3-butylene glycol product according to the present disclosure, at least one of a content of methyl vinyl ketone, a content of acetone, a content of butylaldehyde, a content of acetaldol, a content of a compound represented by Formula (1) below, a content of a compound represented by Formula (2) below, and a content of a compound represented by Formula (3) below, and a total content of a compound represented by Formula (4) below and a compound represented by Formula (5) below, is less than 8 ppm.
Each of the contents of methyl vinyl ketone, acetone, butylaldehyde, acetaldol, the compound represented by Formula (1), the compound represented by Formula (2), the compound represented by Formula (3), the compound represented by Formula (4), and the compound represented by Formula (5) can be quantified by GC-MS analysis performed under the following conditions. In GC-MS analysis, even very small peaks are all subjected to mass spectrometry, and each component is quantified. Since the analysis is performed for a specific mass, a substance different in mass is not detected even when another impurity overlaps the peak. Therefore, the analysis is more sensitive than GC analysis which will be described below. In the present specification, the unit “ppm” of the content of each component by GC-MS analysis means “ppm by weight”.

Conditions for GC-MS Analysis

Analytical Column: a column with dimethylpolysiloxane as a stationary phase, having a length of 30 m, an inner diameter of 0.25 mm, and a film thickness of 1.0 μm
Heating conditions: heating from 80° C. to 120° C. at 5° C./min, then heating again to 160° C. at 2° C./min and maintaining for 2 minutes, and further heating to 230° C. at 10° C./min and maintaining at 230° C. for 18 minutes
Sample Introduction Temperature: 250° C.
Carrier Gas: helium
Column Gas Flow Rate: 1 mL/min
Ion source temperature: EI 230° C., CI 250° C.
Q Pole temperature: 150° C.
Sample: subjected to analysis as it is
Retention times of peaks of methyl vinyl ketone, acetone, butylaldehyde, acetaldol [CH₃CH(OH)CH₂CH(═O)], and the compound represented by Formula (1) below are usually shorter than a retention time of a peak of 1,3-butylene glycol. In the above analytical conditions, the retention time of a peak of 1,3-butylene glycol is usually from 5.5 minutes to 7 minutes. When a relative retention time of the peak of 1,3-butylene glycol is defined as 1.0 under the above analysis conditions, a relative retention time of the peak of methyl vinyl ketone is from 0.3 to 0.5, a relative retention time of the peak of acetone is from 0.3 to 0.5, a relative retention time of the peak of butylaldehyde is from 0.3 to 0.5, a relative retention time of the peak of acetaldol is from 0.4 to 0.6, and a relative retention time of the peak of the compound represented by Formula (1) above is from 0.6 to 0.8. The compound represented by Formula (1) is an acetal compound produced by a reaction of acetaldehyde with 1,3-butylene glycol.
Under the above analysis conditions, retention times of peaks of the compound represented by Formula (2), the compound represented by Formula (3), the compound represented by Formula (4), and the compound represented by Formula (5) are usually longer than the retention time of the peak of 1,3-butylene glycol. When the relative retention time of the peak of 1,3-butylene glycol is defined as 1.0 under the above analysis conditions, a relative retention time of the peak of the compound represented by Formula (2) is from 1.3 to 1.7, a relative retention time of the peak of the compound represented by Formula (3) is from 1.0 to 1.2, a relative retention time of the peak of the compound represented by Formula (4) is from 1.6 to 2.0, and a relative retention time of the peak of the compound represented by Formula (5) is from 1.3 to 1.7. The compound represented by Formula (2) is an acetal compound produced by a reaction of crotonaldehyde with 1,3-butylene glycol. The compound represented by Formula (3) is 1,3-butanediol monoacetate produced by a reaction of acetic acid with 1,3-butylene glycol. The compound represented by Formula (4) and the compound represented by Formula (5) are acetaldehyde multimeric acetals [the compound represented by Formula (4) has a hydroxy group, and the compound represented by Formula (5) does not have a hydroxy group).
In the 1,3-butylene glycol product according to the present disclosure, at least one of eight contents: the content of methyl vinyl ketone, the content of acetone, the content of butylaldehyde, the content of acetaldol, the content of the compound represented by Formula (1) below, the content of the compound represented by Formula (2) below, the content of the compound represented by Formula (3) below, and the total content of the compound represented by Formula (4) below and the compound represented by Formula (5) below, is less than 8 ppm (for example, 7 ppm or less, preferably 6 ppm or less, more preferably 5 ppm or less, even more preferably 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less). Thus, among the eight contents, one content may be less than 8 ppm (for example, 7 ppm or less, preferably 6 ppm or less, more preferably 5 ppm or less, even more preferably 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less): two contents may be less than 8 ppm (for example, 7 ppm or less, preferably 6 ppm or less, more preferably 5 ppm or less, even more preferably 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less), three contents may be less than 8 ppm (for example, 7 ppm or less, preferably 6 ppm or less, more preferably 5 ppm or less, even more preferably 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less), four contents may be less than 8 ppm (for example, 7 ppm or less, preferably 6 ppm or less, more preferably 5 ppm or less, even more preferably 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less): five contents may be less than 8 ppm (for example, 7 ppm or less, preferably 6 ppm or less, more preferably 5 ppm or less, even more preferably 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less), six contents may be less than 8 ppm (for example, 7 ppm or less, preferably 6 ppm or less, more preferably 5 ppm or less, even more preferably 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less); seven contents may be less than 8 ppm (for example, 7 ppm or less, preferably 6 ppm or less, more preferably 5 ppm or less, even more preferably 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less); and all of the eight contents may be less than 8 ppm (for example, 7 ppm or less, preferably 6 ppm or less, more preferably 5 ppm or less, even more preferably 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).
In the 1,3-butylene glycol product, among the eight contents: the content of methyl vinyl ketone, the content of acetone, the content of butylaldehyde, the content of acetaldol, the content of the compound represented by Formula (1), the content of the compound represented by Formula (2), the content of the compound represented by Formula (3), and the total content of the compound represented by Formula (4) and the compound represented by Formula (5), at least four (four, five, six, seven or eight) contents are preferably less than 8 ppm (for example, 7 ppm or less, preferably 6 ppm or less, more preferably 5 ppm or less, even more preferably 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less). Particularly, all of the eight contents are preferably less than 8 ppm (for example, 7 ppm or less, preferably 6 ppm or less, more preferably 5 ppm or less, and even more preferably 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).
In the 1,3-butylene glycol product, among the eight contents: the content of methyl vinyl ketone, the content of acetone, the content of butylaldehyde, the content of acetaldol, the content of the compound represented by Formula (1), the content of the compound represented by Formula (2), the content of the compound represented by Formula (3), and the total content of the compound represented by Formula (4), and the compound represented by Formula (4), at least one (for example, one, two, three, four, . . . or all) of sums of two contents (for example, a sum of the content of methyl vinyl ketone and the content of acetone, a sum of the content of methyl vinyl ketone and the content of butyl aldehyde, a sum of the content of methyl vinyl ketone and the content of acetaldole, a sum of the content of methyl vinyl ketone and the content of the compound represented by Formula (1), a sum of the content of methyl vinyl ketone and the content of the compound represented by Formula (2), a sum of the content of methyl vinyl ketone and the content of the compound represented by Formula (3), a sum of the content of methyl vinyl ketone and the total content of the compound represented by Formula (4) and the compound represented by Formula (5), and a sum of the content of acetone and the content of butyl aldehyde) may be less than 16 ppm (for example, 15 ppm or less, preferably 14 ppm or less, more preferably 13 ppm or less, even more preferably 12 ppm or less, and particularly preferably 11 ppm or less, 10 ppm or less, 9 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).
Further, in the 1,3-butylene glycol product, among the eight contents: the content of methyl vinyl ketone, the content of acetone, the content of butylaldehyde, the content of acetaldol, the content of the compound represented by Formula (1), the content of the compound represented by Formula (2), the content of the compound represented by Formula (3), and the total content of the compound represented by Formula (4), and the compound represented by Formula (5), at least one (for example, one, two, three, four, . . . or all) of sums of three contents (for example, a sum of the content of methyl vinyl ketone, the content of acetone, and the content of butylaldehyde; a sum of the content of methyl vinyl ketone, the content of acetaldol, and the content of the compound represented by the formula (1); and a sum of the content of acetone, the content of butylaldehyde, and the content of acetaldol) may be less than 24 ppm (for example, 20 ppm or less, preferably 18 ppm or less, more preferably 16 ppm or less, even more preferably 14 ppm or less, and particularly preferably 12 ppm or less, 11 ppm or less, 10 ppm or less, 9 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).
Also, in the 1,3-butylene glycol product, among the content of methyl vinyl ketone, the content of acetone, the content of butylaldehyde, the content of acetaldol, the content of the compound represented by Formula (1), the content of the compound represented by Formula (2), the content of the compound represented by Formula (3), and the total content of the compound represented by Formula (4), and the compound represented by Formula (5), at least one (for example, one, two . . . or all) of sums of four contents (for example, a sum of the content of methyl vinyl ketone, the content of acetone, the content of butylaldehyde, and the content of acetaldol; and a sum of the content of acetone, the content of butylaldehyde, the content of acetaldol, and the content of the compound represented by Formula (1)) may be less than 32 ppm (for example, 30 ppm or less, preferably 25 ppm or less, more preferably 20 ppm or less, even more preferably 18 ppm or less, and particularly preferably 16 ppm or less, 14 ppm or less, 12 ppm or less, 10 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).
Further, in the 1,3-butylene glycol product, a sum of the content of methyl vinyl ketone, the content of acetone, the content of butylaldehyde, the content of acetaldol, the content of the compound represented by Formula (1), the content of the compound represented by Formula (2), the content of the compound represented by Formula (3), and the content of the compound represented by Formula (4) and the content of the compound represented by Formula (5) may be less than 71 ppm (for example, 60 ppm or less, preferably 50 ppm or less, more preferably 40 ppm or less, even more preferably 30 ppm or less, and particularly preferably 20 ppm or less, 18 ppm or less, 16 ppm or less, 14 ppm or less, 12 ppm or less, 10 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).
In addition, in the 1,3-butylene glycol product, a sum of the content of methyl vinyl ketone, the content of acetone, the content of butylaldehyde, the content of acetaldol, and the content of the compound represented by Formula (1), which are contents of impurities generally shorter in GC retention time than 1,3-butylene glycol, is preferably less than 47 ppm (for example, 40 ppm or less, preferably 30 ppm or less, more preferably 25 ppm or less, even more preferably 20 ppm or less, and particularly preferably 18 ppm or less, 16 ppm or less, 14 ppm or less, 12 ppm or less, 10 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less), and a sum of the content of the compound represented by Formula (2), the content of the compound represented by Formula (3), the content of the compound represented by Formula (4), and the content of the compound represented by Formula (5), which are contents of impurities generally longer in GC retention time than 1,3-butylene glycol, is preferably less than 24 ppm (for example, 20 ppm or less, preferably 18 ppm or less, more preferably 16 ppm or less, even more preferably 14 ppm or less, and particularly preferably 13 ppm or less, 12 ppm or less, 11 μm or less, 10 ppm or less, 9 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).
It is preferable that, in the 1,3-butylene glycol product according to the present disclosure, at least the content of acetaldol be less than 8 ppm. The acetaldol generates crotonaldehyde by heat. The crotonaldehyde can be a substance that causes coloration, a substance that causes odor, or a substance that causes acidity. The content of acetaldol is more preferably 7 ppm or less, even more preferably 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less.
It is preferable that, in the 1,3-butylene glycol product according to the present disclosure, at least the content of the compound represented by Formula (3) is less than 8 ppm. The compound represented by Formula (3) generates acetic acid by hydrolysis, which causes acetic acid odor. Also, it increases an acid concentration (acid content) of the product. The content of the compound represented by Formula (3) is more preferably 7 ppm or less, and even more preferably 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less.
In the 1,3-butylene glycol product according to the present disclosure, the total content of methyl vinyl ketone, acetone, and butylaldehyde is preferably 24 ppm or less. All of these compounds have a carbonyl group and can be a substance that causes coloration, a substance that causes odor, or a substance that causes acidity. The total content of methyl vinyl ketone, acetone and butylaldehyde is more preferably 20 ppm or less, and even more preferably 18 ppm or less, 16 ppm or less, 14 ppm or less, 12 ppm or less, 11 ppm or less, 10 ppm or less, 9 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less.
In the 1,3-butylene glycol product according to the present disclosure, the total content of the compound represented by Formula (1), the compound represented by Formula (2), the compound represented by Formula (4), and the compound represented by Formula (5) is preferably 24 ppm or less. All of these compounds are acetal compounds, which generate acetaldehyde by hydrolysis. The acetaldehyde can be a substance that causes coloration, a substance that causes odor, or a substance that causes acidity.
In the 1,3-butylene glycol product according to the present disclosure, the content of acetaldehyde is preferably less than 4 ppm (in particular, less than 2 ppm). Furthermore, the content of crotonaldehyde is preferably less than 2 ppm (particularly less than 1.2 ppm). The acetaldehyde and the crotonaldehyde can be substances that cause coloration, substances that cause odor, or substances that cause acidity. They also reduce the potassium permanganate test value of the product. Note that the acetaldehyde content and the crotonaldehyde content of the 1,3-butylene glycol product can be quantified by GC-MS analysis (gas mass spectrometry) described above.
Under the GC-MS analysis conditions, when the relative retention time of the peak of 1,3-butylene glycol is defined as 1.0, a relative retention time of a peak of acetaldehyde is from 0.3 to 0.5, and a relative retention time of a peak of crotonaldehyde is from 0.3 to 0.5.
The content of acetaldehyde in the 1,3-butylene glycol product is more preferably 1.8 ppm or less, even more preferably 1.7 ppm or less, 1.5 ppm or less, 1.4 ppm or less, 1.3 ppm or less, 1.2 ppm or less, 1.1 ppm or less, 1.0 ppm or less, 0.9 ppm or less, 0.8 ppm or less, 0.7 ppm or less, 0.6 ppm or less, or 0.5 ppm or less, and particularly preferably 0.3 ppm or less (for example, 0.2 ppm or less). Furthermore, the content of crotonaldehyde in the 1,3-butylene glycol product is more preferably 1.0 ppm or less, even more preferably 0.9 ppm or less, 0.8 ppm or less, 0.7 ppm or less, 0.6 ppm or less, 0.5 ppm or less, 0.4 ppm or less, or 0.3 ppm or less, and particularly preferably 0.2 ppm or less (e.g., 0.1 ppm or less).
The 1,3-butylene glycol product preferably has an acid concentration of less than 11 ppm in terms of acetic acid, and an acid concentration of less than 23 ppm in terms of acetic acid after a 90 wt. % aqueous solution has been kept at 100° C. for 1 week.
Desirably, the 1,3-butylene glycol product according to the present disclosure preferably has an acid concentration of, for example, 10 ppm or less (preferably 9 ppm or less, more preferably 8 ppm or less, even preferably 7 ppm or less, particularly preferably 6 ppm or less, and most preferably 5 ppm or less, 4 ppm or less, or 3 ppm or less) in terms of acetic acid, and an acid concentration of, for example, 20 ppm or less (preferably 19 ppm or less, 18 ppm or less, 17 ppm or less, or 16 ppm or less, more preferably 15 ppm or less, even more preferably 14 ppm or less, 13 ppm or less, 12 ppm or less, 11 ppm or less, and particularly preferably 10 ppm or less, 9 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, or 2 ppm or less) in terms of acetic acid after a 90 wt. % aqueous solution has been kept at 100° C. for 1 week. The 90 wt. % aqueous solution means an aqueous solution prepared by mixing the 1,3-butylene glycol product and water (e.g., pure water) to adjust the 1,3-butylene glycol product to 90 wt. %.
For the acid concentration in terms of acetic acid of the 90 wt. % aqueous solution of the 1,3-butylene glycol product according to the present disclosure, a ratio of the acid concentration after the solution has been kept at 100° C. for 1 week to the acid concentration before the solution has kept at 100° C. for 1 week, that is [(acid concentration after the solution has been kept at 100° C. for 1 week)/(acid concentration before the solution has been kept at 100° C. for 1 week)×100(%)], is preferably 200% or less, more preferably 150% or less, and even more preferably 120% or less.
Desirably, in the 1,3-butylene glycol product according to the present disclosure, an APHA (Hazen color number) is, for example, 6 or less (preferably 5 or less, more preferably 4 or less, even more preferably 3 or less, and particularly preferably 2 or less). And after the 1,3-butylene glycol product has been kept at 180° C. for 3 hours in air atmosphere, an APHA is, for example, 78 or less (preferably 65 or less, more preferably 60 or less, even more preferably 55 or less, 50 or less, 45 or less, 40 or less, 35 or less, 30 or less, 25 or less, 20 or less, and particularly preferably 18 or less, 15 or less, 14 or less, 13 or less, 12 or less, 11 or less, 10 or less, 9 or less, 8 or less, or 7 or less). Furthermore, an APHA, after the 1,3-butylene glycol product has been kept at 100° C. for 75 days in air atmosphere, is, for example, 42 or less (preferably 35 or less, 30 or less, 25 or less, 20 or less, 18 or less, 16 or less, 15 or less, 14 or less, or 13 or less, more preferably 12 or less, 11 or less, 10 or less, 9 or less, 8 or less, 7 or less, or 6 or less, and even more preferably 5 or less, 4 or less, 3 or less, or 2 or less).
For the APHA of the 1,3-butylene glycol product according to the present disclosure, a ratio of the APHA after the 1,3-butylene glycol product has been kept at 100° C. for 75 days to the APHA before the 1,3-butylene glycol product has been kept at 100° C. for 75 days. [(APHA after the 1,3-butylene glycol product has been kept at 100° C. for 75 days)/(APHA before the 1,3-butylene glycol product has been kept at 100° C. for 75 days)], is not particularly limited, but is preferably 10 or less, more preferably 8 or less, even more preferably 7 or less, and particularly preferably 6 or less (for example, 5 or less, 4 or less, or 3 or less). In addition, the ratio is 1 or greater, or may be 2 or greater.
Additionally, the 1,3-butylene glycol product according to the present disclosure preferably has an initial boiling point of higher than 203° C. The initial boiling point is preferably 204° C. or higher, more preferably 205° C. or higher, even more preferably 206° C. or higher or 207° C. and particularly preferably 208° C. or higher.
Additionally, the 1,3-butylene glycol product according to the present disclosure preferably has a dry point of 209° C. or lower.
The 1,3-butylene glycol product according to the present disclosure preferably has a potassium permanganate test value (PMT) of 30 minutes or longer. The potassium permanganate test value (PMT) is more preferably longer than 30 minutes (e.g., 32 minutes or longer), even more preferably 35 minutes or longer (e.g., 40 minutes or longer), and particularly preferably 50 minutes or longer (especially, 60 minutes or longer).
In the 1,3-butylene glycol product according to the present disclosure, an area ratio (GC area ratio) of the peak of 1,3-butylene glycol is preferably greater than 98.7%, in the gas chromatographic analysis (GC analysis) performed under conditions set forth below. Furthermore, a total area ratio of peaks shorter in retention time than the peak of 1,3-butylene glycol is preferably less than 0.3%. Furthermore, a total area ratio of peaks longer in retention time than the peak of 1,3-butylene glycol is preferably less than 1.2%.
The conditions for the gas chromatographic analysis are as follows:
Analytical Column: a column with dimethylpolysiloxane as a stationary phase, having a length of 30 m, an inner diameter of 0.25 mm, and a film thickness of 1.0 μm
Heating conditions: heating from 80° C. to 120° C. at 5° C./min, then heating again to 160° C. at 2° C./min and maintaining for 2 minutes, and further heating to 230° C. at 10° C./min and maintaining at 230° C. for 18 minutes
Sample Introduction Temperature: 250° C.
Carrier Gas: helium
Column Gas Flow Rate: 1 mL/min
Detector and Detection Temperature: a flame ionization detector (FID), 280° C.
In the present disclosure, the “(peak) area ratio” means a ratio of the area of a specific peak relative to the sum of the areas of all peaks appearing in the chromatogram. In addition, all peaks mean, for example, all of the peaks appearing in the analysis continued until and discontinued at a relative retention time of 7.8, provided that the relative retention time of 1,3-butylene glycol is 1.0. When the area ratios of the peaks are within the ranges described above, the occurrence of odor, the increase in acid concentration over time in a state containing water, and the coloration over time are reduced.
The area ratio of the peak of 1,3-butylene glycol is 98.8% or greater, more preferably 98.9% or greater, even more preferably 99% or greater, 99.1% or greater, 99.2% or greater, 99.3% or greater, 99.4% or greater, 99.5% or greater, 99.6% or greater, or 99.7% or greater, and particularly preferably 99.8% or greater.
The total area ratio of the peaks shorter in retention time than the peak of 1,3-butylene glycol is preferably 0.28% or less, more preferably 0.25% or less, even more preferably 0.23% or less, 0.2% or less, 0.17% or less, 0.15% or less, 0.12% or less, 0.1% or less, 0.07% or less, 0.04% or less, 0.03% or less, 0.02% or less, 0.01% or less, or 0.007% or less, and particularly preferably 0.005% or less (for example, 0.002% or less).
The total area ratio of the peaks longer in retention time than the peak of 1,3-butylene glycol is preferably 1% or less, more preferably 0.9% or less, more preferably 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, or 0.2% or less, and particularly preferably 0.1% or less.
In the 1,3-butylene glycol product according to the present disclosure, a content of water is preferably less than 0.4 wt. %. The content of water is preferably 0.3 wt. % or less, more preferably 0.2 wt. % or less, even more preferably 0.1 wt. % or less, 0.07 wt. % or less, 0.05 wt. % or less, 0.03 wt. % or less, 0.02 wt. % or less, or 0.01 wt. % or less, and particularly preferably 0.005 wt. % or less. Note that the content of water can be quantified by a Karl Fischer water content measurement instrument.
A high-purity and high-quality 1,3-butylene glycol product with little deterioration in quality over time is provided by suppressing the contents of the specific nine compounds, and, additionally, by setting the content of acetaldehyde and the content of crotonaldehyde to within the above ranges, by setting the initial boiling point and the dry point to within the above ranges, and further by setting the potassium permanganate test value, the area ratio of the peak of 1,3-butylene glycol, the total area ratio of the peaks shorter in retention time than the peak of 1,3-butylene glycol, and the total area ratio of the peaks longer in retention time than the peak of 1,3-butylene glycol to within the above ranges.

Moisturizer and Cosmetic Product

A moisturizer of the present disclosure contains the 1,3-butylene glycol product described above. Therefore, the moisturizer has excellent moisturizing performance. The moisturizer of the present disclosure may contain a component besides the 1,3-butylene glycol product described above, such as a moisturizer component besides the 1,3-butylene glycol product described above. In the moisturizer of the present disclosure, the content of the 1,3-butylene glycol product described above is, for example, 10 wt. % or greater, preferably 30 wt. % or greater, more preferably 50 wt. % or greater, even more preferably 80 wt. % or greater, and particularly preferably 90 wt. % or greater, and the moisturizer may be composed of only the 1,3-butylene glycol product described above.
A cosmetic of the present disclosure contains the moisturizer described above. The blending amount of the 1,3-butylene glycol product in the cosmetic product of the present disclosure is any amount in which the moisturizing performance can be exhibited according to the type and form of cosmetic. The blending amount of the 1,3-butylene glycol product in the cosmetic product of the present disclosure is, for example, from 0.01 to 40 wt. %, preferably from 0.1 to 30 wt. %, more preferably from 0.2 to 20 wt. %, even more preferably from 0.5 to 15 wt. %, and particularly preferably from 1 to 10 wt. %.
The cosmetic product of the present disclosure may contain, in addition to the 1,3-butylene glycol product, for example, another moisturizer; an oil, such as a vegetable oil, a hydrocarbon oil, a greater fatty acid, a greater alcohol, or a silicone; a surfactant, such as an anionic surfactant, a cationic surfactant, an amphoteric surfactant, or a nonionic surfactant; a preservative, a sequestrant, a thickener, a powder, an ultraviolet absorber, an ultraviolet blocker, a fragrance, or a pH adjuster; or a medicinal ingredient or bioactive component, such as a vitamin preparation, a skin activator, a blood circulation promoter, a skin-lightening preparation, an antibacterial agent, or an anti-inflammatory agent.
The cosmetic product of the present disclosure can be a skin cosmetic product, such as a lotion, an emulsion, a cream, a gel, a pack, or a mask; or a hair cosmetic product, such as a shampoo, a rinse, or a hair restorer. In addition, the cosmetic product may be a sunscreen cosmetic product, a make-up cosmetic product or the like. Furthermore, the cosmetic product can be a pharmaceutical product or quasi drug containing a medical component.
The cosmetic product of the present disclosure can be produced by utilizing a method known per se.

Method for Producing 1,3-Butylene Glycol

The 1,3-butylene glycol product according to the present disclosure can be produced by the producing method of the present disclosure. The producing method 1 of the present disclosure is a method for producing 1,3-butylene glycol to yield purified 1,3-butylene glycol from a reaction crude liquid containing 1,3-butylene glycol (1,3 BG) (hereinafter, sometimes referred to as “crude 1,3-butylene glycol”), the method including: performing dehydration including removing water by distillation, removing a high boiling point component including removing a high boiling point component by distillation, and performing product distillation to yield purified 1,3-butylene glycol. Then, in the product column for use in the performing product distillation, a 1,3-butylene glycol charged liquid is subjected to distillation under a condition that a reflux ratio is 0.3 or greater, the 1,3-butylene glycol charged liquid having a content of acetaldehyde of 500 ppm or less, a content of crotonaldehyde of 200 ppm or less, a content of water of 0.7 wt. % or less, and a concentration of 1,3-butylene glycol of 97.6 area % according to the gas chromatographic analysis performed under conditions set forth below. A liquid with a concentrated low boiling point component is distilled from above a charging plate, and 1,3-butylene glycol is extracted from below the charging plate. The thus-produced 1,3-butylene glycol is colorless and odorless (or almost colorless and odorless), unlikely to cause or increase coloration and odor over time, and, besides, unlikely to cause an acid concentration increase over time even in a state that the 1,3-butylene glycol contains water. Thus, such 1,3-butylene glycol can constitute a 1,3-butylene glycol product.
The conditions for the gas chromatographic analysis are as follows:
Analytical Column: a column with dimethylpolysiloxane as a stationary phase, having a length of 30 m, an inner diameter of 0.25 mm, and a film thickness of 1.0 μm
Heating conditions: heating from 80° C. to 120° C. at 5° C./min, then heating again to 160° C. at 2° C./min and maintaining for 2 minutes, and further heating to 230° C. at 10° C./min and maintaining at 230° C. for 18 minutes
Sample Introduction Temperature: 250° C.
Carrier Gas: helium
Column Gas Flow Rate; 1 mL/min
Detector and Detection Temperature: a flame ionization detector (FID), 280° C.
The producing method 2 of the present disclosure is a method for producing 1,3-butylene glycol to yield purified 1,3-butylene glycol from a reaction crude liquid containing 1,3-butylene glycol, the method including: performing dehydration including removing water by distillation and removing a high boiling point component including removing a high boiling point component by distillation. In a high boiling point component removal column for use in the removing a high boiling point component, a charged liquid containing 1,3-butylene glycol is subjected to distillation under a condition that a reflux ratio is 0.03 or greater, the charged liquid having a content of acetaldehyde of 500 ppm or less, a content of crotonaldehyde of 200 ppm or less, a content of water of 3 wt. % or less, and a concentration of 1,3-butylene glycol of 96.7 area % or greater according to the gas chromatographic analysis performed under conditions set forth below. The higher-purity 1,3-butylene glycol is distilled from above the charging plate, and a liquid in which a high boiling point component is concentrated is extracted from below the charging plate. The thus-produced 1,3-butylene glycol is colorless and odorless (or almost colorless and odorless), unlikely to cause or increase coloration and odor over time, and, besides, unlikely to cause an acid concentration increase over time even in a state that the 1,3-butylene glycol contains water. Thus, such 1,3-butylene glycol can constitute a 1,3-butylene glycol product.
The “producing method 1 of the present disclosure” and the “producing method 2 of the present disclosure” are collectively referred to as “producing method of the present disclosure” in some cases.
Crude 1,3-butylene Glycol
Examples of the crude 1,3-butylene glycol include (1) a reaction crude liquid produced by reduction (hydrogenation) of an acetaldol, (2) a reaction crude liquid produced by hydrolysis of 1,3-butylene oxide, (3) a reaction crude liquid produced by selective hydrocracking of erythritol, (4) a reaction crude liquid produced by selective hydration to butadiene. (5) a reaction crude liquid produced by hydrogen addition to n-butanal-3-one, (6) a reaction crude liquid produced by hydrogen addition to 1-butanol-3-one. (7) a reaction crude liquid produced by hydrogen addition to 3-hydroxy-1-butanoic acid, (8) a reaction crude liquid produced by hydrogen addition to D-butyrolactone, and (9) a reaction crude liquid produced by hydrogen addition to diketene. In the present disclosure, the crude 1,3-butylene glycol may be one type or a mixture of two or more types of the above (1) to (9). The crude 1,3-butylene glycol is preferably (1) the reaction crude liquid produced by reduction (in particular, liquid phase reduction) of an acetaldol.
Hereinafter, a case where the reaction crude liquid produced by reduction (hydrogenation) of an acetaldol is used as the crude 1,3-butylene glycol will be mainly described. Note that the reduction (hydrogenation) of an acetaldol is sometimes referred to as “hydrogenation”.
The acetaldol used as a raw material in the hydrogenation is not particularly limited as long as it is a compound that becomes 1,3-butylene glycol by hydrogen reduction. Examples of the raw material acetaldols include acetaldol; its cyclic dimer paraldol; aldoxane as a cyclic trimer of acetaldehyde; and mixtures of these.
The method of producing the acetaldol (e.g., acetaldol or paraldol) is not particularly limited, but the acetaldol may be, for example, those produced by an aldol condensation reaction of acetaldehyde in the presence of a basic catalyst or those produced by pyrolysis or the like of aldoxane. Note that the production of the acetaldol is sometimes referred to as “acetaldol production” or “acetaldehyde polymerization”.
A reaction crude liquid produced by the reaction described above and containing an acetaldol may be neutralized with an acid and used in the production of 1,3-butylene glycol. Such a reaction crude liquid may contain, in addition to an acetaldol, acetaldehyde (AD), crotonaldehyde (CR), another aldehyde component: a low boiling point substance; a high boiling point substance, such as an aldehyde dimer or trimer; water; a salt; and the like. In the present specification, a compound with a lower boiling point than that of 1,3-butylene glycol may be referred to as a “low boiling point substance” or “low boiling substance”, and a compound with a higher boiling point than that of 1,3-butylene glycol may be referred to as a “high boiling point substance” or “high boiling substance”.
The reaction crude liquid containing an acetaldol may be subjected to a pretreatment, such as dealcoholization distillation, dehydration distillation, desalting, alkaline treatment and dealkalization treatment, or impurity removal, as necessary, and a product produced by removing by-products, such as unreacted acetaldehyde and crotonaldehyde, may be used. Examples of the pretreatment method include distillation, adsorption, ion exchange, conversion to a high boiling point substance by heating, and decomposition. For the distillation, a distillation method of various types, such as reduced pressure, normal pressure, increased pressure, azeotropic, extraction, or reaction, can be used. In particular, it is preferred that the reaction crude liquid containing an acetaldol is subjected to simple evaporation, distillation, or hydrogen addition to remove aldehydes such as acetaldehyde and crotonaldehyde, followed by the hydrogenation.
The content of the acetaldol in the raw material for hydrogenation is not particularly limited but is, for example, preferably 30 wt. % or greater (e.g., from 30 to 99 wt. %), more preferably 40 wt. % or greater (for example, from 40 to 98 wt. %), 50 wt. % or greater (for example, from 50 to 97 wt. %) or 60 wt. % or greater (for example, from 60 to 95 wt. %), and even more preferably from 65 to 90 wt. %, particularly preferably from 70 to 90 wt. %, and most preferably from 75 to 90 wt. %. With the content of the acetaldol within the above ranges, impurities contained in the reaction crude liquid containing 1,3-butylene glycol (crude 1,3-butylene glycol) tend to be reduced.
The raw material for hydrogenation may or may not contain water but preferably contains water from the viewpoint of the purity of 1,3-butylene glycol product. The water content in the raw material for hydrogenation is not particularly limited but is, for example, preferably 2 wt. % or greater, more preferably 5 wt. % or greater, even more preferably 10 wt. % or greater, and particularly preferably 15 wt. % or greater. The upper limit may be, for example, 90 wt. %, 80 wt %, 70 wt. %, 60 wt. %, 50 wt. %, 40 wt. %, 30 wt. % or 20 wt. %. With the water content within the above ranges, the acetal of 1,3-butylene glycol and acetaldol contained in the resulting crude 1,3-butylene glycol is decreased, and thus this tends to increase the purity of the 1,3-butylene glycol product finally produced. This is because the raw material for hydrogenation contains water to a certain extent, and the acetal is hydrolyzed into 1,3-butylene glycol accordingly as well as coexisting acetaldol is reduced into 1,3-butylene glycol.
Examples of the hydrogenation catalyst include Raney nickel. The hydrogenation catalyst can also be used in a suspended state, and can also be filled in a reaction vessel and used. The amount of the hydrogenation catalyst to be used is not particularly limited but is, for example, preferably from 1 to 30 parts by weight, more preferably from 4 to 25 parts by weight, even more preferably from 8 to 20 parts by weight, and particularly preferably from 12 to 18 parts by weight relative to 100 parts by weight of the raw material for hydrogenation. The amount of hydrogen to be used in the reduction reaction is not particularly limited but is, for example, preferably from 0.5 to 40 parts by weight, more preferably from 1 to 30 parts by weight, even more preferably from 4 to 20 parts by weight, and particularly preferably from 8 to 12 parts by weight relative to 100 parts by weight of the raw material for hydrogenation. A pressure (total pressure, gauge pressure) in a reaction system in the reduction reaction is not particularly limited but is, for example, preferably from 9 to 70 MPa and more preferably from 10 to 40 MPa. A hydrogen pressure (partial pressure of hydrogen) in the reaction system is not particularly limited, but is, for example, from 7 to 60 MPa, and preferably from 10 to 30 MPa. Note that, from the perspective of reducing the amount of the reducing materials such as acetaldehyde and crotonaldehyde, it is better to increase the hydrogen pressure in the reaction system, and the hydrogen pressure is preferably 10 MPa or greater, and may be 100 MPa. A reaction temperature in the reduction reaction is not particularly limited but is, for example, from 40 to 150° C., preferably from 50 to 140° C., and more preferably from 60 to 130° C. A reaction time (residence time) in the reduction reaction is not particularly limited but is, for example, from 10 to 500 minutes, preferably from 20 to 400 minutes, more preferably from 30 to 300 minutes, even more preferably from 50 to 280 minutes, and particularly preferably from 80 to 250 minutes. The present reaction can be carried out in any of a batch, semi-batch, or continuous manner.
For example, the thus-produced crude 1,3-butylene glycol contains a low boiling point substance (low boiling point compound) having an unsaturated bond, such as acetaldehyde (AD), butylaldehyde, crotonaldehyde (CR), acetone, and methyl vinyl ketone; a condensate of these; a condensate of 1,3-butylene glycol and the above low boiling point substance (e.g., an acetal of 1,3-butylene glycol and acetaldol): an alcohol such as ethanol, isopropyl alcohol, or butanol; water (for example, solvent), a salt produced by neutralization or the like, a catalyst (when used in suspension) or the like. These impurities are removed in the purification, and a 1,3-butylene glycol product (purified 1,3-butylene glycol) can be produced.

Purification of Crude 1,3-Butylene Glycol

The production method 1 according to the present disclosure includes, at least, performing dehydration including removing water by distillation, removing a high boiling point component including removing a high boiling point component by distillation (high boiling point component removal distillation), and performing product distillation to yield purified 1,3-butylene glycol. In the production method 2 of the present disclosure, at least dehydration for removing water by distillation and high boiling point component removal for removing a high boiling point component by distillation (high boiling point component removal distillation).
In the production method of the present disclosure, the order of the performing dehydration and the removing a high boiling point component does not matter. In the producing method 1 of the present disclosure, both the performing dehydration and the removing a high boiling point component are provided prior to the product distillation. The production method according to the present disclosure may include, in addition to these steps, desalting, alkaline reaction (alkaline treatment), and dealkalization. Additionally, prior to the dehydration, catalyst separation, neutralization by alkali, dealcoholization (low boiling point component removal), and the like can be provided. These steps may be performed in the order described above, but the order of the steps may be changed as appropriate except that the dealkalization is provided after the alkaline reaction. For example, the dealcoholization (low boiling point component removal), the desalting, the alkaline reaction, and the dealkalization can be provided at appropriate locations, but are usually provided after the hydrogenation. Note that, among the above-described steps, the catalyst separation, the neutralization by alkali, the dealcoholization (low boiling point component removal), the desalting, the alkaline reaction, and the dealkalization may be provided as necessary, and do not necessarily have to be provided.
FIG. 1 is a flow sheet of an apparatus illustrating an example of an embodiment of a method for producing 1,3-butylene glycol of the present disclosure. A is a dehydration column and is related to the dehydration. B is a desalting column and is related to the desalting. C is a distillation column for removing a high boiling point component (high boiling point component removal column) and is related to the high boiling point component removal distillation (high boiling point component removal). D is an alkaline reactor and is related to the alkaline reaction. E is a dealkalization column and is related to the dealkalization. F is a product distillation column (product column) and is related to the product distillation. A-1, B-1, C-1, E-1, and F-1 are condensers. A-2, C-2, and F-2 are reboilers. Hereinafter, an example of an embodiment of the method for producing 1,3-butylene glycol of the present disclosure will be described using the present flow sheet.
Crude 1,3-butylene glycol (corresponding to “X-1”) produced by hydrogen reduction of a raw material for hydrogenation is fed to the dehydration column A. Note that the crude 1,3-butylene glycol (corresponding to “X-1”) may be fed to the dehydration column A after undergoing the dealcoholization (distillation by a dealcoholization column) for removing an alcohol such as ethanol and a low boiling point substance.
In the production method of the present disclosure, in the dehydration column A used in the dehydration, for example, a charged liquid containing 1,3-butylene glycol and water is subjected to distillation, and a liquid having a concentrated low boiling point component containing water is distilled from above the charging plate (preferably, the top of the column) (corresponding to “X-2” in FIG. 1 ). Further, a crude 1,3-butylene glycol stream containing 1,3-butylene glycol can be produced from below the charging plate (preferably, the bottom of the column).
The dehydration column A and any other distillation column for separating 1,3-butylene glycol can be, for example, perforated-plate columns, bubble columns, and the like, but are more preferably packed columns with a low pressure loss, filled with Sulzer Packing, Melapack (trade names of Sumitomo Heavy Industries, Ltd.). This is because 1,3-butylene glycol and trace impurities would be thermally decomposed at a high temperature (e.g., 150° C. or higher) and form a low boiling point substance, which is a coloring component, and thus the distillation temperature is to be lowered. In addition, this is also because a long thermal history (residence time) for 1,3-butylene glycol would also have a similar effect. Thus, the reboiler employed is preferably one with a short residence time of the process side fluid, for example, a thin-film evaporator, such as a natural downward flow thin-film evaporator or a forced-stirring thin-film evaporator.
A theoretical number of plates of the dehydration column A is, for example, from 1 to 100 plates, preferably from 2 to 80 plates, from 3 to 80 plates, from 4 to 60 plates, from 5 to 40 plates, from 6 to 30 plates or from 7 to 20 plates, and more preferably from 8 to 15 plates. A feed position for the charged liquid is, for example, from 10 to 90%, preferably from 20 to 80%, and more preferably from 30 to 70%, and even more preferably from 40 to 60% of a height of the column downward from the top of the column. In the distillation in the dehydration column A, the pressure (absolute pressure) of the top of the column is, for example, 101 kPa or less, preferably from 0.1 to 90 kPa, more preferably from 0.5 to 70 kPa, and even more preferably from 1 to 50 kPa, from 2 to 30 kPa or from 3 to 20 kPa. and particularly preferably from 4 to 10 kPa. Note that the distillation in the dehydration column A may be performed under increased pressure, in which case the pressure (gauge pressure) at the top of the column may be, for example, 0.2 MPaG or less, or 0.1 MPaG or less.
A concentration of 1,3-butylene glycol in the charged liquid into the dehydration column A is, for example, 9 wt. % or greater, preferably 10 wt. % or greater, more preferably 15 wt. % or greater, even more preferably 20 wt. % or greater, 25 wt. % or greater, 30 wt. % or greater, 35 wt. % or greater, 40 wt. % or greater, 45 wt. % or greater, 50 wt. % or greater, 55 wt. % or greater, or 60 wt. % or greater, and particularly preferably 70% or greater. An upper limit of the concentration of 1,3-butylene glycol in the charged liquid into the dehydration column A is, for example, 90 wt. %, 85 wt %, or 80 wt. %. However, in consideration of the hydrogen addition reaction and the like in the step prior to the dehydration, the concentration of water in the charged liquid into the dehydration column A is preferably greater in some cases. Taken together, the concentration of 1,3-butylene glycol in the charged liquid into the dehydration column A may be, for example, 1 wt. % or greater, 5 wt. % or greater, 10 wt. % or greater, 15 wt. % or greater, 20 wt. % or greater, 25 wt % or greater, 30 wt. % or greater, 35 wt. % or greater, 40 wt % or greater, 50 wt. % or greater, 60 wt. % or greater, 70 wt % or greater, 80 wt. % or greater, or 90 wt. % or greater. Furthermore, the concentration of 1,3-butylene glycol in charged liquid into the dehydration column A may be, for example, 99 wt. % or less, 95 wt. % or greater, 90 wt. % or less, 85 wt. % or less, 80 wt. % or less, 75 wt. % or less, 70 wt. % or less, 65 wt. % or less, 60 wt. % or less, 55 wt. % or less, 50 wt. % or less, or 45 wt. % or less. The concentration of 1,3-butylene glycol in the charged liquid into the dehydration column A can be, for example, in the range described above by adjusting the reaction conditions in the hydrogenation (for example, the concentration of an acetaldol used as a raw material) and the distillation conditions of the dealcoholization column (low boiling point component removal column) provided before the dehydration column as needed.
The concentration (wt. %) of 1,3-butylene glycol is a value determined according to the following formula by determining an area proportion (GC area %) of the peak of 1,3-butylene glycol relative to a total peak area in the gas chromatographic analysis under the following conditions. Note that the concentration (wt. %) of water in the charged liquid into the dehydration column A is a value measured by the method which will be described below (Karl Fischer method).
Concentration (Wt. %) of 1,3-Butylene Glycol in Charged Liquid into Dehydration Column A=[1−(concentration (wt. %) of water in charged liquid into dehydration column A)/100]×(GC area % of 1,3-butylene glycol described above)
The conditions for the gas chromatographic analysis are as follows:
Analytical Column: a column with dimethylpolysiloxane as a stationary phase, having a length of 30 m, an inner diameter of 0.25 mm, and a film thickness of 1.0 μm
Heating conditions: heating from 80° C. to 120° C. at 5° C./min then heating again to 160° C. at 2° C./min and maintaining for 2 minutes, and further heating to 230° C. at 10° C./min and maintaining at 230° C. for 18 minutes
Sample Introduction Temperature: 250° C.
Carrier Gas: helium
Column Gas Flow Rate; 1 mL/min
Detector and Detection Temperature: a flame ionization detector (FID), 280° C.
In the production method of the present disclosure, a content of acetaldehyde in the charged liquid into the dehydration column A is, for example, 1000 ppm or less, preferably 900 ppm or less, more preferably 800 ppm or less, 700 ppm or less, 600 ppm or less, or 500 ppm or less, even more preferably 400 ppm or less, 300 ppm or less, 200 ppm or less, 155 ppm or less, or 140 ppm or less, and may be 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, ppm or less, or 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, or 1 ppm or less.
The content of crotonaldehyde in charged liquid into the dehydration column A may be, for example, 400 ppm or less, preferably 300 ppm or less, more preferably 200 ppm or less, even more preferably 150 ppm or less, 130 ppm or less, 117 ppm or less, or 100 ppm or less, and may be 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, or 1 ppm or less.
The acetaldehyde content and the crotonaldehyde content in the charged liquid into the dehydration column A can be reduced, for example, by providing a dealcoholization column (low boiling point component removal column) upstream of the dehydration column A, and adjusting the distillation conditions of the dealcoholization column (low boiling point component removal column). For example, increasing the reflux ratio and the number of plates, and the distillation ratio of the dealcoholization column (low boiling point component removal column) can reduce the acetaldehyde content and the crotonaldehyde content of the charged liquid into the dehydration column A. Furthermore, the contents can be adjusted according to the conditions for the hydrogen addition reaction in the hydrogenation, and when hydrogen addition is completely performed, the concentrations of acetaldehyde and crotonaldehyde can be reduced to below the detection limit, but there are disadvantages of a high reaction pressure, an increase in size of the reaction tank and the like.
Note that the acetaldehyde content and the crotonaldehyde content of the charged liquid into the dehydration column A can be quantified by GC-MS analysis (gas mass spectrometry).
In the production method of the present disclosure, the content of water in the charged liquid into the dehydration column A is, for example, 90 wt. % or less, 85 wt. % or less, 80 wt. % or less, 70 wt. % or less, 60 wt. % or less, 50 wt. % or less, or 40 wt. % or less, and preferably 35 wt. % or less, more preferably 30 wt. % or less, and even more preferably 25 wt. % or less. A lower limit of the water content of the charged liquid into the dehydration column A is, for example, 15 wt. % or 10 wt %. Note that, when the hydrogen addition reaction in the hydrogenation is taken into consideration, the greater the water concentration and the smaller the viscosity, the greater the solubility and dispersity of hydrogen in the liquid, which is advantageous for the hydrogen addition reaction. The water content of the charged liquid into the dehydration column A can be reduced, for example, by providing a dealcoholization column (low boiling point component removal column) upstream of the dehydration column A. and adjusting the distillation conditions of the dealcoholization column (low boiling point component removal column). For example, increasing the reflux ratio and the number of plates, and the distillation ratio of the dealcoholization column (low boiling point component removal column) can reduce the water content of the charged liquid into the dehydration column A. Note that the water content of the charged liquid into the dehydration column A can be quantified by the Karl Fischer water content measurement instrument.
In the production method of the present disclosure, the content of the low boiling point component (excluding water) in the charged liquid into the dehydration column A is, for example, 20% or less, preferably 10% or less, more preferably 8% or less, even more preferably 5% or less, and particularly preferably 3% or less or 2% or less, and may be 1% or less, 0.5% or less, or 0.1% or less. The content of the low boiling point component (also referred to as “low boiling point substance” or “low boiling substance”) excluding water in the charged liquid into the dehydration column A is a total area proportion (area %) of peaks of shorter in retention time than the peak of 1,3-butylene glycol relative to the total peak area in the gas chromatographic analysis under the above conditions. The content of the low boiling point component (excluding water) in the charged liquid into the dehydration column A can be reduced, for example, by providing a dealcoholization column (low boiling point component removal column) upstream of the dehydration column A, and adjusting the distillation conditions of the dealcoholization column (low boiling point component removal column). For example, increasing the reflux ratio and the number of plates, and the distillation ratio of the dealcoholization column (low boiling point component removal column) can reduce the content of the low boiling point component (excluding water) in the charged liquid into the dehydration column A. Furthermore, the concentration of the low boiling point component (excluding water) in the charged liquid into the dehydration column A can be reduced, for example, by reaction conditions (e.g., reaction temperature) in the hydrogenation.
The content of the high boiling point component in the charged liquid into the dehydration column A is, for example, 20% or less, preferably 10% or less, more preferably 7% or less, 4% or less, 3% or less, or 2% or greater, even more preferably 1% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, 0.1% or less, or 0.05% or less, and particularly preferably 0.01% or less. The content of the high boiling point component in the charged liquid into the dehydration column A can be adjusted, for example, by reaction conditions (e.g., reaction temperature) in the hydrogenation. The content of the high boiling point component in the charged liquid into the dehydration column A is a total area proportion (area %) of peaks longer in retention time than the peak of 1,3 BG to the total peak area in the gas chromatographic analysis under the above conditions. (area %).
In the production method of the present disclosure, the reflux ratio [dehydration column reflux amount/dehydration column distilled amount (discharge amount to outside of distillation column)] in the dehydration column A is, for example, greater than 0.3, preferably 0.4 or greater, 0.5 or greater, 0.6 or greater, or 0.7 or greater, 0.8 or greater, 0.9 or greater, 1 or greater, 1.1 or greater, 1.2 or greater, 1.3 or greater, 1.4 or greater, 1.5 or greater, 1.6 or greater, 1.7 or greater, 1.8 or greater, 1.9 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater, 6 or greater, 7 or greater, 8 or greater, 9 or greater, 10 or greater, 15 or greater, 20 or greater or 25 or greater, and more preferably 30 or greater (for example, 40 or greater) from the perspective of reducing the content of the low boiling point substance (including water) in the crude 1,3-butylene glycol stream containing 1,3-butylene glycol taken out from below the charging plate of the dehydration column A (preferably, the bottom of the column). In particular, in the production method 2 of the present disclosure, the reflux ratio in the dehydration column A is preferably 10 or greater, more preferably 20 or greater, even more preferably 30 or greater, and particularly preferably 50 or greater. An upper limit of the reflux ratio is, for example, 100, preferably 50 from the point of energy cost. In a case where the theoretical number of plates of the dehydration column A is large, sufficient separation can be performed, even when the reflux ratio is 10 or 20 or less.
In the production method of the present disclosure, the distillation ratio in the dehydration column A can be appropriately set in accordance with the concentration of water in the charged liquid into the dehydration column A. Desirably, the distillation ratio is a sufficient distillation ratio for the total amount of water in the charged liquid to be distilled. For example, in a case where the concentration of water in the charged liquid into the dehydration column A is X wt. %, the distillation ratio in the dehydration column A is preferably X wt. % or greater. Therefore, the distillation ratio in the dehydration column A is, for example, 95 wt. % or less, 90 wt. % or less, 85 wt. % or less, 80 wt. % or less, 75 wt. % or less, 70 wt. % or less, 65 wt. % or less, 60 wt. % or less, 55 wt. % or less, 50 wt. % or less, 45 wt. % or less, 40 wt. % or less, 35 wt. % or less, 30 wt. % or less, 25 wt. % or less, 20 wt. % or less, 15 wt. % or less, 10 wt. % or less, or 5 wt. % or less. The distillation ratio refers to a proportion (wt. %) of an amount of liquid extracted from above the charging plate of the dehydration column A (e.g., the top of the column) to the outside of the distillation column with respect to a charged amount into the dehydration column A.
In the production method of the present disclosure, the 1,3 BG recovery ratio in the dehydration column A is, for example, 99.3% or greater. Note that, in the present specification, the 1.3 BG recovery ratio in the dehydration column A is a value (%) determined by the following formula.
{1−[concentration (wt. %) of 1,3 BG in distillate×(distilled amount (part)−recycled amount (part))]/(concentration (wt. %) of 1,3 BG in charged liquid×charged amount (part))}×100
Note that the low boiling point substance and the high boiling point substance may be hydrolyzed by water to produce 1,3 BG, while the high boiling point substance may be formed by polymerization of 1,3 BG. Further, trace impurities may be formed or disappear. Thus, the mass balance in the dehydration column may not always be retained. This applies to the dealcoholization column (low boiling point component removal column), the high boiling point component removal column, the product column, and other distillation columns.
Next, the crude 1,3-butylene glycol stream containing 1,3-butylene glycol taken out from below the charging plate of the dehydration column A (preferably, the bottom of the column) is fed to the desalting column B. In the desalting column B, the crude 1,3-butylene glycol stream after the desalting is produced from the top of the column, and a salt, a high boiling point substance, or the like is discharged from the bottom of the column. The bottom ratio (%) of the desalting column B [(desalting column bottom amount (part)/desalting column charge amount (part)×100] is, for example, from 0.1 to 40 wt. %, preferably from 1 to 35 wt. %, more preferably from 2 to 30 wt. %, even more preferably from 3 to 25 wt. %, and particularly preferably from to 20 wt. %, and may be from 7 to 15 wt. %. At least a portion of the bottom in the desalting column may be recycled to the step prior to the desalting.
The crude 1,3-butylene glycol stream after the desalting described above is fed to the high boiling point component removal column C. In the high boiling point component removal column C, the high boiling point component (high boiling point substance) is discharged from below the charging plate (preferably, from the bottom of the column). On the other hand, the crude 1,3-butylene glycol stream after high boiling point substance removal (1,3-butylene glycol with improved purity) is produced from above the charging plate.
The high boiling point component removal column C can be, for example, a perforated-plate column, a bubble column, or the like, but is more preferably a packed column with a low pressure loss, filled with Sulzer Packing, Melapack (trade names of Sumitomo Heavy Industries, Ltd.). This is because 1,3-butylene glycol and trace impurities would be thermally decomposed at a high temperature (e.g., 150° C. or higher) and form a low boiling point substance, which is a coloring component, and thus the distillation temperature is to be lowered. In addition, this is also because a long thermal history (residence time) for 1,3-butylene glycol would also have a similar effect. Thus, the reboiler employed is preferably one with a short residence time of the process side fluid, for example, a thin-film evaporator, such as a natural downward flow thin-film evaporator or a forced-stirring thin-film evaporator.
A theoretical number of plates of the high boiling point component removal column C is, for example, from 1 to 100 plates, preferably from 2 to 90 plates, more preferably from 3 to 80 plates, more preferably from 4 to 70 plates, from 5 to 60 plates, from 8 to 50 plates, or from 10 to 40 plates, and particularly preferably from 15 to 30 plates. A feed position for the charged liquid is, for example, from 10 to 90%, preferably from 20 to 80%, and more preferably from 30 to 70 plates, and even more preferably from 40 to 60% of a height of the column downward from the top of the high boiling point component removal column. In the distillation in the high boiling point component removal column C, a pressure (absolute pressure) at the top of the column is, for example, from 0.01 to 50 kPa, preferably from 0.1 to 30 kPa, more preferably from 0.3 to 20 kPa, and even more preferably from 0.5 to 10 kPa.
In the production method 1 of the present disclosure, a concentration of 1,3 BG in the charged liquid into the high boiling point component removal column C is, for example, 95% or greater, preferably 96% or greater (for example, 96.7% or greater), more preferably 97% or greater, even more preferably 98% or greater, and particularly preferably 99% or greater. In the production method 2 of the present disclosure, the concentration of 1,3 BG in the charged liquid into the high boiling point component removal column C is 96.7% or greater, preferably 97% or greater, more preferably 98% or greater, and even more preferably 99% or greater. The concentration of 1,3 BG into the charged liquid into the high boiling point component removal column C can be improved by adjusting the distillation conditions of the dehydration column A and the desalting column B. For example, increasing the reflux ratio of the dehydration column A or increasing the bottom ratio of the desalting column B can increase the concentration of 1,3 BG in the charged liquid into the high boiling point component removal column C. Note that the concentration of the 1,3 BG described above is an area proportion (area %) of a 1, 3 BG peak relative to a total peak area in a gas chromatographic analysis (GC analysis) under the following conditions.
The conditions for the gas chromatographic analysis are as follows:
Analytical Column: a column with dimethylpolysiloxane as a stationary phase, having a length of 30 m, an inner diameter of 0.25 mm, and a film thickness of 1.0 μm
Heating conditions: heating from 80° C. to 120° C. at 5° C./min, then heating again to 160° C. at 2° C./min and maintaining for 2 minutes, and further heating to 230° C. at 10° C./min and maintaining at 230° C. for 18 minutes
Sample Introduction Temperature: 250° C.
Carrier Gas: helium
Column Gas Flow Rate: 1 mL/min
Detector and Detection Temperature: a flame ionization detector (FID), 280° C.
A content of the high boiling point component in the charged liquid into the high boiling point component removal column C is, for example, 4% or less, preferably 3% or less, more preferably 2% or less, even more preferably 1% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, 0.1% or less, or 0.05% or less, and particularly preferably 0.01% or less. In particular, in the production method 2 of the present disclosure, a content of the high boiling point component in the charged liquid into the high boiling point component removal column C is preferably 3% or less, more preferably 2% or less, even more preferably 1.5% or less, 1% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, 0.1% or less, or 0.05% or less, and particularly preferably 0.01% or less. The content of the high boiling point component in the charged liquid into the high boiling point component removal column C can be reduced by adjusting the distillation conditions of the desalting column B. For example, increasing the bottom ratio of the desalting column B can reduce the content of the high boiling point component in the charged liquid into the high boiling point component removal column C. Note that the content of the high boiling point component in the charged liquid into the high boiling point component removal column C is a total area proportion (area %) of peaks longer in retention time than the 1,3 BG peaks relative to the total peak area in the gas chromatographic analysis under the above conditions.
In the production method of the present disclosure, the content of acetaldehyde in charged liquid into the high boiling point component removal column C is, for example, 500 ppm or less, preferably 205 ppm or less (e.g., 200 ppm or less), more preferably 100 ppm or less, even more 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, and particularly preferably 5 ppm or less, and may be less than 2 ppm, or less than 1 ppm. The content of crotonaldehyde in the charged liquid into the high boiling point component removal column C is, for example, 200 ppm or less, preferably 110 ppm or less, more preferably 100 ppm or less, even more 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, and particularly preferably 2 ppm or less, and may be less than 1 ppm. The acetaldehyde content and the crotonaldehyde content in the charged liquid into the high boiling point component removal column C can be reduced, for example, by providing a dealcoholization column (low boiling point component removal column) and a dehydration column upstream of the high boiling point component removal column C, and adjusting the distillation conditions of the dealcoholization column (low boiling point component removal column) and the dehydration column. For example, increasing the reflux ratio and the number of plates, and the distillation ratio of the dealcoholization column (low boiling point component removal column) and the dehydration column can reduce the acetaldehyde content and the crotonaldehyde content of the charged liquid into the high boiling point component removal column C. Note that the acetaldehyde content and the crotonaldehyde content of the charged liquid into the high boiling point component removal column C can be quantified by GC-MS analysis (gas mass spectrometry).
In the production method of the present disclosure, the content of water in charged liquid into the high boiling point component removal column C is, for example, 3 wt. % or less, preferably 2 wt. % or less, more preferably 1.2 wt. % or less, more preferably 1.1 wt. % or less, 1.0 wt. % or less, 0.95 wt. % or less, 0.9 wt. % or less, 0.8 wt. % or less, 0.7 wt. % or less, 0.6 wt. % or less, 0.5 wt. % or less, 0.4 wt. % or less, 0.3 wt. % or less, or 0.2 wt. % or less, and particularly preferably 0.1 wt. % or less. The content of water in the charged liquid into the high boiling point component removal column C can be reduced by adjusting the distillation conditions of the dehydration column A For example, increasing the reflux ratio and the number of plates, and the distillation ratio of the dehydration column A can reduce the concentration of water in the charged liquid into the high boiling point component removal column C. Note that the water content of the charged liquid into the high boiling point component removal column CF can be quantified by the Karl Fischer water content measurement instrument. In the production method 2 of the present disclosure, the content of water in the charged liquid into the high boiling point component removal column C is 3 wt. % or less, preferably 2 wt. % or less, 1.2 wt. % or less, 0.4 wt. % or less, 0.3 wt. % or less, or 0.2 wt. % or less, and particularly preferably 0.1 wt. % or less, 0.05 wt. % or less, or 0.03 wt. % or less.
In the production method of the present disclosure, the content of the low boiling point component (excluding water) in the charged liquid into the high boiling point component removal column C is, for example, 1.8% or less, preferably 1.6% or less, more preferably 1.4% or less, more preferably 1.2% or less, 1.1% or less, 1% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, or 0.2% or less, and particularly preferably 0.1% or less. The content of the low boiling point component (also referred to as “low boiling point substance” or “low boiling substance”) excluding water in the charged liquid into the high boiling point component removal column C is a total area proportion (area %) of peaks of shorter in retention time than the peak of 1,3-butylene glycol relative to the total peak area in the gas chromatographic analysis under the above conditions. The content of the low boiling point component (excluding water) in the charged liquid into the high boiling point component removal column C can be reduced, for example, by providing a dealcoholization column (low boiling point component removal column) upstream of the high boiling point component removal column C, and adjusting the distillation conditions of the dealcoholization column (low boiling point component removal column). For example, increasing the reflux ratio and the number of plates, and the distillation ratio of the dealcoholization column (low boiling point component removal column) can reduce the content of the low boiling point component (excluding water) in the charged liquid into the high boiling point component removal column C.
In the production method of the present disclosure, the reflux ratio [(high boiling point component removal column reflux amount)/(high boiling point component removal column distilled amount (discharge amount to outside of distillation column))] in the high boiling point component removal column C is 0.03 or greater, preferably 0.05 or greater, more preferably 0.1 or greater, even more preferably 0.2 or greater, 0.3 or greater, 0.4 or greater, 0.5 or greater, 0.6 or greater, 0.7 or greater, 0.8 or greater, 0.9 or greater, 1 or greater, 1.2 or greater, 1.5 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater, or 10 or greater, and particularly preferably 20 or greater, from the perspective of reducing the dry point of the 1,3-butylene glycol product. In particular, in the production method 2 of the present disclosure, the reflux ratio in the high boiling point component removal column C is preferably 0.1 or greater, more preferably 0.2 or greater, 0.3 or greater, 0.4 or greater, 0.5 or greater, 0.6 or greater, 0.7 or greater, 0.8 or greater, 0.9 or greater, 1 or greater, 1.2 or greater, 1.5 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater, or 10 or greater, and particularly preferably 20 or greater. An upper limit of the reflux ratio is, for example, 100, preferably 50 from the point of energy cost. In a case where the theoretical number of plates of the high boiling point component removal column C is large, sufficient separation can be performed, even when the reflux ratio in the high boiling point component removal column C is about 1 or less.
In the production method of the present disclosure, the reflux ratio in the high boiling point component removal column C is within the range described above, and thus highly pure 1,3 BG having a very low content of the high boiling point component and a low dry point can be produced with a high recovery ratio.
In the production method of the present disclosure, the bottom ratio of the high boiling point component removal column C is, for example, less than 30 wt. %. Note that it is not limited to the value when the bottom of the high boiling point component removal column is distilled in a further distillation column and a high boiling point substance is removed therefrom, and 1,3 BG is yielded as the product. When an extracted amount of the material containing a high boiling point substance to the outside of the system is reduced to less than 30 wt. % with respect to the charged amount into the high boiling point component removal column C, it is possible to produce 1,3 BG in a high yield. Note that the bottom ratio refers to a proportion (wt. %) of an amount of liquid extracted from below the charging plate (for example, bottom of the column) of the high boiling point component removal column C with respect to a charged amount into the high boiling point component removal column C (also including an amount of the liquid recycled, when the liquid is recycled to the previous steps which will be described later). Note that when the liquid is recycled to the previous steps described below, the recovery ratio of 1,3 BG is improved as the discharge ratio to the outside is less.
The bottom ratio of the high boiling point component removal column C can also be preferably 25 wt. % or less, more preferably 20 wt. % or less, even more preferably 15 wt. % or less, 10 wt. % or less, 7 wt. % or less, 5 wt. % or less, 4 wt. % or less, 3 wt. % or less, or 2 wt. % or less, and can be 1 wt. % or less, from the perspective of improving the recovery ratio of 1,3 BG. In addition, the bottom ratio of the high boiling point component removal column is, for example, 0.01 wt. % or greater, preferably 0.1 wt. % or greater, 0.5 wt. % or greater, or 1 wt. % or greater, more preferably 2 wt. % or greater, 3 wt. % or greater, 4 wt. % or greater, 5 wt. % or greater, 6 wt. % or greater, 7 wt. % or greater, 8 wt. % or greater, 9 wt. % or greater, 10 wt. % or greater, or 15 wt. % or greater, and particularly preferably 20 wt. % or greater, from the perspective of reducing the dry point of the 1,3-butylene glycol product.
At least a portion of the liquid (hereinafter, sometimes referred to as “bottom”) in which the high boiling point component is concentrated, the high boiling point component having been extracted from below the charging plate of the high boiling point component removal column C, may be recycled to step prior to the removing a high boiling point component (dashed arrow illustrated in the lower part of the high boiling point component removal column C in FIG. 1 ). The recovery ratio of 1,3 BG can be improved by recycling at least a portion of the bottom to the step prior to the removing a high boiling point component. Note that, in the present specification, the recovery ratio of 1,3 BG in the high boiling point component removal column C is a value (%) determined by the following formula.
{1−[GC area % of 1,3 BG in bottom×(bottom amount (part)−amount (part) of bottom recycled]/(GC area % of 1,3 BG in charged liquid×charged amount (part)}×100
Note that the low boiling point substance and the high boiling point substance may be hydrolyzed by water to produce 1,3 BG, while the high boiling point substance may be formed by polymerization of 1,3 BG. Further, trace impurities may be formed or disappear. Thus, the mass balance in the high boiling point component removal column may not always be retained.
The recovery ratio of 1,3 BG in the high boiling point component removal column C is, for example, greater than 80%, preferably 85% or greater, more preferably 90% or greater, even more preferably 95% or greater, and particularly preferably 99% or greater.
Examples of the step prior to the removing a high boiling point component include acetaldehyde polymerization (aldol condensation of acetaldehyde), reaction (hydrogenation), dealcoholization (low boiling point component removal), dehydration, and desalting. The bottom is preferably recycled to the acetaldehyde polymerization (aldol condensation of acetaldehyde), among these steps, since 1,3 BG is produced by hydrolysis of the high boiling point substance. In addition, the hydrogen addition reduction may produce 1.3 BG, and the bottom may be recycled to the hydrogen addition from that viewpoint.
The amount of the bottom recycled to the step prior to the removing a high boiling point component can be appropriately selected within a range of the amount of the bottom. The amount of the bottom recycled to the step prior to the removing a high boiling point component is, for example, less than 30 wt. %, preferably 25 wt. % or less with respect to the charged amount into the high boiling point component removal column C. Note that the amount of the bottom recycled may be 20 wt. % or less, 15 wt. % or less, 10 wt. % or less, 7 wt. % or less, 5 wt. % or less, 4 wt. % or less, 3 wt. % or less, 2 wt. % or less, or 1 wt. % or less with respect to the charged amount into the high boiling point component removal column C. In addition, from the perspective of improving the recovery ratio of 1,3 BG in the high boiling point component removal column and the yield throughout the 1,3 BG production process, the amount of the bottom recycled to the step prior to the removing a high boiling point component is, for example, 0.01 wt. % or greater, preferably 0.1 wt. % or greater, more preferably 2 wt. % or greater, 3 wt. % or greater, 4 wt. % or greater, 5 wt. % or greater, 7 wt. % or greater, or 10 wt. % or greater, and particularly preferably 20 wt. % or greater relative to the amount of charge into the high boiling point component removal column C. Note that, in a case where the amount of the bottom is minimized as much as possible, 1,3 BG can be recovered in a high yield, even without recycle to the previous steps.
The crude 1,3-butylene glycol stream taken out from above the charging plate of the high boiling point component removal column C can be a 1,3-butylene glycol product as it is in the production method 2 of the present disclosure. Alternatively, the crude 1,3-butylene glycol stream taken out from above the charging plate of the high boiling point component removal column C is subjected to alkaline treatment in the alkaline reactor D described below, and evaporated (or distilled) with the dealkalization column E, and the distillate at the top of the dealkalization column E can be a 1,3-butylene glycol product.
According to the production method 2 of the present disclosure, the content of acetaldehyde and the content of crotonaldehyde in the charged liquid into the high boiling point component removal column are within the specific ranges, and the reflux ratio of the high boiling point component removal column is within the specific range. Therefore, it is possible to industrially efficiently yield high-purity 1,3-butylene glycol that is colorless and odorless (or almost colorless and odorless), unlikely to cause or increase coloration and odor over time, and, besides, unlikely to cause an acid concentration increase over time even in a state containing water.
In the production method 1 of the present disclosure, the crude 1,3-butylene glycol stream taken out from above the charging plate of the high boiling point component removal column C is fed, for example, to the alkaline reactor (e.g., a flow-through tubular reactor) D and is treated with a base (treated with alkali). The base treatment can decompose by-products contained in the crude 1,3-butylene glycol. The base is added in the alkaline reactor D or its upstream piping or the like. The base is added in an amount of, for example, from 0.05 to 10 wt. %, preferably from 0.1 to 1.0 wt. % relative to the crude 1,3-butylene glycol stream subjected to the alkaline treatment. With the added amount of the base exceeding 10 wt. %, the base would precipitate in the distillation column, piping, or the like, and this may cause blockage. In addition, the decomposition reaction of a high boiling point compound would occur, and by-products may be formed on the contrary. With the added amount of the base of less than 0.05 wt. %, the effect of decomposing by-products is reduced.
The base added in the alkaline reactor D or its upstream piping is not particularly limited but is, for example, preferably an alkali metal compound. Examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, sodium (bi)carbonate, and potassium (bi)carbonate. A basic ion exchange resin can also be used as the base. The base is preferably sodium hydroxide or potassium hydroxide from the perspective of reducing the by-products contained in the final 1,3-butylene glycol product. The base may be added as is in the solid form but is preferably added in an aqueous solution to facilitate operation and contact with a solution to be treated. One of the bases described above may be used alone, or two or more may be used simultaneously.
The reaction temperature in the alkaline reactor D is not particularly limited but is, for example, preferably from 90 to 140° C. and more preferably from 110 to 130° C. The reaction at a reaction temperature less than 90° C. would require long reaction residence time and thus require a reactor with a large volume and make the process uneconomical. The reaction at a reaction temperature exceeding 140° C. would increase coloration in the final 1,3-butylene glycol product. The reaction residence time is, for example, preferably from 5 to 120 minutes and more preferably from 10 to 30 minutes. A reaction residence time shorter than 5 minutes may cause an insufficient reaction and deteriorate the quality of the final 1,3-butylene glycol product. A reaction residence time exceeding 120 minutes would require a large reactor and increase the cost of equipment, and thus would be disadvantageous from the economic point of view.
After exiting the alkaline reactor D, the reaction crude liquid stream is fed to the dealkalization column (e.g., thin film evaporator) E as necessary, and the base and the like are removed from the bottom of the column by evaporation. On the other hand, from the top of the dealkalization column E, a crude 1,3-butylene glycol stream after the removal of a base (which is used as the 1,3-butylene glycol product, in the production method 2 of the present disclosure) is produced. The evaporator used for the dealkalization column E is suitably a natural downward flow thin-film evaporator or a forced-stirring thin-film evaporator with a short residence time for the purpose of reducing the thermal history to the process fluid. A demister may be installed in a space above the charging position of the dealkalization column (e.g., thin film evaporator) E, and droplets of a base or the like may be removed. This makes it possible to prevent the base and the like from being mixed into the 1,3-butylene glycol product.
Evaporation is performed in the evaporator used for the dealkalization column E, for example, under a reduced pressure at the top of the column of 20 kPa or less (absolute pressure), preferably from 0.5 to 10 kPa (absolute pressure). The temperature of the evaporator is, for example, preferably from 90 to 120° C. The crude 1,3-butylene glycol stream containing a low boiling point substance distilled from the top of the column is fed to the product distillation column (product column) F. Note that, as described above, in the production method 2 of the present disclosure, the distillate (corresponding to E-1) from the top of the dealkalization column E can be a 1,3-butylene glycol product.
Note that the alkaline reactor D and the dealkalization column E may be installed between the desalting column B and the high boiling point component removal column C, between the dehydration column A and desalting column B (in this case, the desalting column may also serve as a dealkalization column), or before the dehydration column A. In addition, without the alkaline reactor D or the dealkalization column E being provided, the alkaline treatment can be performed by charging the base into a high boiling point component removal column charging line or into a dehydration column charging line, or adding the base to the reaction solution after the hydrogenation [and then charging the base into the dealcoholization column (low boiling point component removal column)].
In the production method 1 of the present disclosure, in the product column F for use in the product distillation, a charged liquid having a concentration of 1,3-butylene glycol of, for example, 97.6 area % or greater determined by GC analysis is distilled, a liquid with a concentrated low boiling point component is distilled from above the charging plate (corresponding to “X-6” in FIG. 1 ), and 1,3-butylene glycol is extracted from below the charging plate (corresponding to “Y” in FIG. 1 ). The extracted 1,3-butylene glycol can be a 1,3-butylene glycol product.
The product column F can be, for example, a perforated-plate column, a bubble column, or the like, but is more preferably a packed column with a low pressure loss, filled with Sulzer Packing, Melapack (trade names of Sumitomo Heavy Industries, Ltd.). This is because 1,3-butylene glycol and trace impurities would be thermally decomposed at a high temperature (e.g., 150° C. or higher) and form a low boiling point substance, which is a coloring component, and thus the distillation temperature is to be lowered. In addition, this is also because a long thermal history (residence time) for 1,3-butylene glycol would also have a similar effect. Thus, the reboiler employed is preferably one with a short residence time of the process side fluid, for example, a thin-film evaporator, such as a natural downward flow thin-film evaporator or a forced-stirring thin-film evaporator.
A theoretical number of plates of the product column F is, for example, from 1 to 100 plates, preferably from 2 to 90 plates, from 3 to 80 plates, from 4 to 70 plates, from 5 to 60 plates, from 8 to 50 plates, or from 10 to 40 plates, and more preferably from 15 to 30 plates. A feed position for the charged liquid is, for example, from 10 to 90%, preferably from 20 to 80%, and more preferably from 30 to 70%, and even more preferably from 40 to 60% of a height of the column downward from the top of the column. In the distillation in the product distillation column F, a pressure (absolute pressure) at the top of the column is, for example, from 20 kPa or less, preferably from 0.1 to 10 kPa, more preferably from 0.3 to 8 kPa, and even more preferably from 0.5 to 5 kPa
In FIG. 1 , in charging to the product column F, the column top vapor from the dealkalization column E is condensed in the condenser E-1, and the resulting condensed liquid is fed, but the column top vapor from the dealkalization column E may be directly fed to the product column F.
The concentration of 1,3-butylene glycol in the charged liquid (1,3-butylene glycol charged liquid) into the product column F is 97.6% or greater, preferably 97.8% or greater, more preferably 98% or greater, even more preferably 98.2% or greater (e.g., 98.4% or greater, 98.6% or greater, or 98.8% or greater), and particularly preferably 99% or greater (e.g., 99.1% or greater, 99.2% or greater, 99.3% or greater, 99.4% or greater, 99.5% or greater, 99.6% or greater, 99.7% or greater, 99.8% or greater, or 99.9% or greater).
The concentration of 1,3-butylene glycol in the charged liquid into the product column F can be improved, for example, by adjusting the distillation conditions of the dehydration column A; providing a dealcoholization column (low boiling point component removal column) before the dehydration column A, and adjusting the distillation conditions thereof; or adjusting the distillation conditions of the high boiling point component removal column C. For example, it is possible to increase the purity of 1,3-butylene glycol in charged liquid into the product column F by increasing the reflux ratio of the dealcoholization column (low boiling point component removal column), the dehydration column A, and/or the high boiling point component removal column C or increasing the number of plates.
Note that the concentration of 1,3-butylene glycol in the charged liquid into the product column F is an area proportion (area %) of the peak of 1,3-butylene glycol relative to the total peak area in the gas chromatographic analysis of the following conditions.
The conditions for the gas chromatographic analysis are as follows:
Analytical Column: a column with dimethylpolysiloxane as a stationary phase, having a length of 30 m, an inner diameter of 0.25 mm, and a film thickness of 1.0 μm
Heating conditions: heating from 80° C. to 120° C. at 5° C./min, then heating again to 160° C. at 2° C./min and maintaining for 2 minutes, and further heating to 230° C. at 10° C./min and maintaining at 230° C. for 18 minutes
Sample Introduction Temperature: 250° C.
Carrier Gas: helium
Column Gas Flow Rate; 1 mL/min
Detector and Detection Temperature: a flame ionization detector (FID), 280° C.
In the production method 1 of the present disclosure, the content of acetaldehyde in charged liquid into the product column F is 500 ppm or less, preferably 205 ppm or less (e.g., 200 ppm or less), more preferably 150 ppm or less, even more preferably 120 ppm or less, 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, ppm or less, or 10 ppm or less, and particularly preferably 5 ppm or less, and may be less than 2 ppm. The content of crotonaldehyde in the charged liquid into the product column F is 200 ppm or less, preferably 150 ppm or less, more preferably 130 ppm or less, even more preferably 110 ppm or less, 100 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, or 3 ppm or less, and particularly preferably 2 ppm or less, and may be less than 1 ppm. The acetaldehyde content and the crotonaldehyde content in the charged liquid into the product column F can be reduced, for example, by providing a dealcoholization column (low boiling point component removal column) and a dehydration column upstream of the product column F, and adjusting the distillation conditions of the dealcoholization column (low boiling point component removal column) and the dehydration column. For example, increasing the reflux ratio and the number of plates, and the distillation ratio of the dealcoholization column (low boiling point component removal column) and the dehydration column can reduce the acetaldehyde content and the crotonaldehyde content of the charged liquid into the product column F. In addition, the acetaldehyde content and the crotonaldehyde content in the charged liquid into the product column F can be reduced by increasing the reaction temperature, increasing the residence time, or increasing the added amount of the base, in the alkaline reaction. Note that the acetaldehyde content and the crotonaldehyde content of the charged liquid into the product column F can be quantified by GC-MS analysis (gas mass spectrometry).
In the production method 1 of the present disclosure, a content of water in charged liquid into the product column F is 0.7 wt. % or less, preferably 0.6 wt. % or less, 0.5 wt. % or less, 0.4 wt. % or less, 0.3 wt. % or less, or 0.2 wt. % or less, and particularly preferably 0.1 wt. % or less. The content of water in the charged liquid into the product column F can be reduced by adjusting the distillation conditions of the dehydration column A. For example, increasing the reflux ratio and the number of plates, and the distillation ratio of the dehydration column A can reduce the concentration of water in the charged liquid into the product column F. Note that the water content of the charged liquid into the product column F can be quantified by the Karl Fischer water content measurement instrument.
The content of the low boiling point component (excluding water) in the charged liquid into the product column F is, for example, 1.8% or less, preferably 1.6% or less, more preferably 1.4% or less, more preferably 1.2% or less, 1.1% or less, 1% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, or 0.2% or less, and particularly preferably 0.1% or less. The content of the low boiling point component (also referred to as “low boiling point substance”) excluding water in the charged liquid into the product column F is a total area proportion (area %) of peaks of shorter in retention time than the peak of 1,3-butylene glycol relative to the total peak area in the gas chromatographic analysis under the above conditions. The content of the low boiling point component (excluding water) in the charged liquid into the product column F can be reduced, for example, by providing a dealcoholization column (low boiling point component removal column) upstream of the product column F, and adjusting the distillation conditions of the dealcoholization column (low boiling point component removal column). For example, increasing the reflux ratio and the number of plates, and the distillation ratio of the dealcoholization column (low boiling point component removal column) can reduce the content of the low boiling point component (excluding water) in the charged liquid into the product column F.
The content of the high boiling point component (excluding water) in the charged liquid into the product column F is, for example, 1.8% or less, preferably 1.6% or less, more preferably 1.4% or less, more preferably 1.2% or less, 1.1% or less, 1% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, or 0.2% or less, and particularly preferably 0.1% or less. The content of the high boiling point component (also referred to as “high boiling point substance” or “high boiling substance”) excluding water in the charged liquid into the product column F is a total area proportion (area %) of peaks of longer in retention time than the peak of 1,3-butylene glycol relative to the total peak area in the gas chromatographic analysis under the above conditions. The content of the high boiling point component (excluding water) in the charged liquid into the product column F can be reduced, for example, by adjusting the distillation conditions of the high boiling point component removal column. For example, increasing the reflux ratio, the number of plates, or the bottom ratio of the high boiling point component removal column can reduce the content of the high boiling point component (excluding water) in the charged liquid into the product column F.
In the production method 1 of the present disclosure, the reflux ratio [(product column reflux amount)/(product column distilled amount (discharge amount to outside of distillation column))] in the product column F is 0.3 or greater, preferably 0.4 or greater, more preferably 0.5 or greater, 1 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater, 6 or greater, 7 or greater, 8 or greater, 9 or greater, 10 or greater, 20 or greater, or 50 or greater, and particularly preferably 400 or greater (for example, 50) or greater), from the perspective of increasing the initial boiling point of the 1,3-butylene glycol product. An upper limit of the reflux ratio of the product column F is, for example, 700 or 1000 from the perspective of energy cost.
In the production method 1 of the present disclosure, the distillation ratio of the product column F is, for example, less than 30 wt. %, 29 wt. % or less, more preferably 28 wt. % or less, even more preferably 27 wt. % or less, 26 wt. % or less, 25 wt. % or less, 24 wt. % or less, 23 wt. % or less, 22 wt. % or less, 21 wt. % or less, 20 wt. % or less, 19 wt. % or less, 18 wt. % or less, 17 wt. % or less, 16 wt. % or less, 15 wt. % or less, 12 wt. % or less, 10 wt. % or less, 8 wt. % or less, 5 wt. % or less, 3 wt. % or less, 2 wt. % or less, 1 wt. % or less, 0.8 wt. % or less, or 0.6 wt. % or less, and particularly preferably 0.4 wt. % or less, from the perspective of improving the recovery ratio of 1,3-butylene glycol. Note that the distillation ratio refers to a proportion (wt. %) of an amount of liquid extracted from above the charging plate of the product column F (for example, the top of the column) to the outside of the distillation column (when recycled to the previous step which will be described below, including also the amount of liquid recycled) with respect to a charged amount into the product column F.
At least a portion of the liquid (hereinafter, sometimes referred to as “distillate”) in which the low boiling component is concentrated, which is extracted from above the charging plate of the product column F, may be recycled to the step prior to the product distillation (dashed arrow illustrated on the right side of the product column F in FIG. 1 ). The recovery ratio of 1,3-butylene glycol can be improved by recycling at least a portion of the distillate to the step prior to the product distillation.
Examples of the step prior to the product distillation include dehydration and dealcoholization (low boiling point component removal). Note that the dealcoholization (low boiling point component removal) is preferably provided before the dehydration.
The amount of the distillate recycled to the step prior to the product distillation can be appropriately selected within the range of the amount of distillate. The amount of the distillate recycle to the step prior to the product distillation is less than 30 wt. %, for example, with respect to the charged amount into the product column F. Also, from the perspective of improving the 1,3 BG recovery ratio in the product column and the yield throughout the process, the amount of the distillate recycled to the step prior to the product distillation is, for example, 0.01 wt. % or greater, preferably 0.05 wt. % or greater, more preferably 0.1 wt. % or greater, 0.5 wt. % or greater, 1 wt. % or greater, 1.5 wt. % or greater, 2 wt. % or greater, 3 wt. % or greater, 4 wt. % or greater, 5 wt. % or greater, 7 wt. % or greater, or 10 wt. % or greater, and particularly preferably 20 wt. % or greater with respect to the charged amount into the product column F.
In the production method 1 of the present disclosure, the content of acetaldehyde and the content of crotonaldehyde in the charged liquid into product column F are within the specific ranges, and the reflux ratio of the product column F is within the specific range. Therefore, it is possible to industrially efficiently produce high-purity 1,3-butylene glycol that is colorless and odorless (or almost colorless and odorless), unlikely to cause or increase coloration and odor over time, and, besides, unlikely to cause an acid concentration increase over time even in a state containing water.
The recovery ratio of 1,3 BG in the product column F is, for example, greater than 80%, preferably 85% or greater, more preferably 90% or greater, even more preferably 95% or greater, and particularly preferably 99% or greater.
Note that, in the present specification, the recovery ratio of 1,3 BG in the product column F is a value (%) determined by the following formula.
{1−[GC area % of 1,3 BG in distillate×(distilled amount (part)−amount (part) of distillate recycled]/(GC area % of 1,3 BG in charged liquid charged amount (part))×100
Note that, as described above, the low boiling point substance and the high boiling point substance may be hydrolyzed by water to produce 1,3 BG, while the high boiling point substance may be formed by polymerization of 1,3 BG. Thus, the mass balance in the product column may not always be retained.
Each aspect disclosed in the present specification can be combined with any other feature disclosed herein. Note that each of the configurations, combinations thereof, and the like in each of the embodiments are an example, and various additions, omissions, and other changes may be made as appropriate without departing from the spirit of the present disclosure. The present disclosure is not limited by the embodiments and is limited only by the claims.

EXAMPLES

Hereinafter, the present disclosure will be described more specifically with reference to examples, but the present disclosure is not limited by these examples. “Parts” used in the examples means “parts by weight” unless otherwise specified. Gas chromatographic analysis (GC analysis), initial boiling point measurement, and water content measurement were performed according to methods which will be described below.

Example 1

The method of producing 1,3-butylene glycol will be described using FIG. 1 .
Relative to 100 parts of an acetaldol solution containing 30 wt. % of water (mixed solution of 69 parts of acetaldol and 29 parts of water, containing a total of 2 parts of low boiling and high boiling impurities, Na salt; less than 0.1 parts) as a raw material, 10 parts of hydrogen were charged in a reactor for liquid-phase hydrogen reduction, and 15 parts of Raney nickel were added as a catalyst. The reactor was kept at 120° C. and 10 MPa (gauge pressure), and liquid-phase hydrogen reduction was performed. After the catalyst was separated, the liquid after the reaction was neutralized with sodium hydroxide, and crude 1,3-butylene glycol (1) containing water was produced.
Note that the acetaldol solution containing 30 wt. % of water used as the raw material was produced by stirring acetaldehyde and water in the presence of 100 ppm by weight NaOH at 30° C. at a residence time of 10 hours and dimerizing the acetaldehyde [acetaldehyde polymerization (aldol condensation of acetaldehyde)].
The crude 1,3-butylene glycol (1) (corresponding to “X-1” in FIG. 1 ) was charged in the dehydration column A. The concentration of 1,3-butylene glycol in the charged liquid into the dehydration column A was 56 wt. %, the water concentration was 40 wt. %, the content of acetaldehyde (AD) was 130 ppm, the content of crotonaldehyde (CR) was 89 ppm, the total area ratio of impurity peaks shorter in retention time (RT) than 1,3-butylene glycol in GC analysis which will be described later was 3%, and the total area ratio of impurity peaks longer in retention time than 1,3-butylene glycol was 1%. In the dehydration column A, the charged liquid containing 1,3-butylene glycol was distilled under conditions of a pressure at the top of 10 kPa (absolute pressure) and a reflux ratio of 1, water was extracted from the top of the column, and 43 parts (distilled amount) relative to 100 parts of the charged liquid amount was discharged and removed to the outside of the system (corresponding to “X-2” in FIG. 1 ). From the bottom of the column, crude 1,3-butylene glycol (2) having a 1,3-butylene glycol concentration of 96.9 GC area %, a water content of 0.9 wt. %, a total area ratio of impurity peaks shorter in retention time than 1,3-butylene glycol in the GC analysis which will be described later of 0.8%, a total area ratio of peaks longer in retention time than peak of 1,3-butylene glycols of 2.3%, an acetaldehyde content of 18 ppm, and a crotonaldehyde content of 17 ppm was produced.
The crude 1,3-butylene glycol (2) was then charged in the desalting column B. In the desalting column B, a salt, a high boiling point substance, and a portion of 1,3-butylene glycol were discharged as the evaporation residue from the bottom of the column (corresponding to “X-3” in FIG. 1 ). The discharge amount of the evaporation residue was 5 parts relative to 100 parts of the charged liquid amount. On the other hand, from the top of the column, crude 1,3-butylene glycol (3) containing 1,3-butylene glycol, a low boiling point substance, and a portion of a high boiling point substance was produced.
The crude 1,3-butylene glycol (3) was then charged in the high boiling point component removal column C. In the high boiling point component removal column C, distillation was performed under the conditions of a pressure at the top of the column of 5 kPa (absolute pressure) and a reflux ratio of 0.05, and a high boiling point substance and a portion of 1,3-butylene glycol were discharged from the bottom of the column (corresponding to “X-4” in FIG. 1 ). The discharge amount from the bottom of the column was 20 parts relative to 100 parts of the charged liquid amount. On the other hand, 80 parts of crude 1,3-butylene glycol (4) containing a low boiling point substance was produced, as a distillate, from the top of the column.
The crude 1,3-butylene glycol (4) was then charged in the alkaline reactor D. At this time, a 20 wt. % sodium hydroxide aqueous solution was added to give a concentration of sodium hydroxide of 0.1 wt. % relative to the charged liquid. The reaction temperature was maintained at 120° C. in the alkaline reactor D, and a reaction was performed at a residence time of 20 minutes.
A reaction crude liquid exiting the alkaline reactor D was then charged in the dealkalization column E. In the dealkalization column E, sodium hydroxide, a high boiling point substance, and a portion of 1,3-butylene glycol were discharged from the bottom of the column (corresponding to “X-5” in FIG. 1 ). The discharge amount from the bottom of the column was 10 parts relative to 100 parts of the charged liquid amount. On the other hand, from the top of the column 90 parts of crude 1,3-butylene glycol (5) containing 1,3-butylene glycol and a low boiling point substance were produced. The crude 1,3-butylene glycol (5) containing 1,3-butylene glycol and a low boiling point substance was measured for water content, and subjected to GC analysis and GC-MS analysis. As a result, the water concentration was 1 wt. %, the area ratio of 1,3-butylene glycol was 99%, the total area ratio of impurity peaks shorter in retention time than 1,3-butylene glycol was 0.4%, the total area ratio of impurity peaks longer in retention time than 1,3-butylene glycol was 0.6%, the content of acetaldehyde was 20 ppm, and the content of crotonaldehyde was 9 ppm.
The crude 1,3-butylene glycol (5) was then charged in the product column F. In the product column F, 10 parts of the low boiling point substance and a portion of 1,3-butylene glycol relative to 100 parts of the charged liquid amount were distilled off from the top of the column (corresponding to “X-6” in FIG. 1 ), and the entire amount was discharged to the outside of the system. The operation was performed at a reflux ratio (reflux amount/distilled amount) of 0.5 at that time, and 90 parts of a 1,3-butylene glycol product was produced from the bottom of the column (distilled amount: 10 parts) (corresponding to “Y” in FIG. 1 ).
The produced 1,3-butylene glycol product was measured for initial boiling point and water content, and subjected to GC analysis and GC-MS analysis. As a result, the 1,3-butylene glycol product had an initial boiling point of 203.3° C. a dry point of 209° C. a water concentration of 0.2 wt. %, an area ratio of 1,3-butylene glycol of 99.2%, a total area ratio of impurity peaks shorter in retention time than 1,3-butylene glycol of 0.08%, a total area ratio of impurity peaks longer in retention time than 1,3-butylene glycol of 0.7%, an acetaldehyde content of 1.5 ppm, and a crotonaldehyde content of 0.9 ppm. The potassium permanganate test value was 35 minutes. The 1,3-butylene glycol recovery ratio in the product column F was 90%.

Example 2

The same operation as in Example 1 was performed except that the reflux ratio of the dehydration column A was changed to 50. A 1,3-butylene glycol product was produced from the bottom of the product column F. Note that, due to the changes in conditions employed in the dehydration column A, the dehydration column bottom composition changed, and the charged liquid compositions in the high boiling point component removal column C and the product column F changed. As a result, the product qualities changed.
The produced 1,3-butylene glycol product was measured for initial boiling point and water content, and subjected to GC analysis and GC-MS analysis. As a result, the 1,3-butylene glycol product had an initial boiling point of 206.7° C., a dry point of 208.9° C., a water concentration of 0.1 wt. %, an area ratio of 1,3-butylene glycol of 99.3%, a total area ratio of impurity peaks shorter in retention time than 1,3-butylene glycol of 0.05%, a total area ratio of impurity peaks longer in retention time than 1,3-butylene glycol of 0.7%, an acetaldehyde content of 0.7 ppm, and a crotonaldehyde content of 0.7 ppm. The potassium permanganate test value was 45 minutes. The 1,3-butylene glycol recovery ratio in the product column F was 90%.

Examples 3 to 27

Under the conditions shown in Table 1 and Table 2, the dehydration column A, the high boiling point component removal column C, and the product column F were operated. In Examples 4 to 22 and 24 to 27, the entire amount of the distillate from the product column F was recycled into hydrogen reduction reactor. In Example 23, the product column F was not used, and a distillate at the top of the dealkalization column E (demister was installed in a space above the charging position) was a 1,3-butylene glycol product. At this time, the concentration of the sodium hydroxide aqueous solution in the alkaline reactor D was set to 1.5 times, and the added amount of the sodium hydroxide aqueous solution was set to the half of the amount in Example 1. Thus, the increase in water content due to alkaline treatment was avoided as much as possible. Note that, when the alkali concentration of the sodium hydroxide aqueous solution is too high and crystals precipitate. Therefore, heating is preferably performed to 40° C. or higher. In Table 2, the column “Bottom from product column F” of Example 23 shows the composition and physical properties of the distillate at the top of the dealkalization column E. Note that, in Example 16, 8 parts of 10 parts of the bottom from the high boiling point component removal column was recycled into the hydrogenation, and 2 parts thereof was discharged to the outside of the system. In addition, in Example 25, the pressure of the hydrogen addition reaction was reduced to 7 MPaG (gauge pressure). Therefore, the acetaldehyde content and crotonaldehyde content of the charged liquid into the dehydration column are high. In Example 26, the reflux ratio of the dehydration column was reduced to 0.3, and the purity of 1,3-butylene glycol in the charged liquid into the product column was reduced, and the reflux ratio of the product column was increased to 20. In Example 27, the pressure of the hydrogen addition reaction was increased to 40 MPaG (gauge pressure) (the remaining conditions are the same as in Example 18).

Comparative Example 1

Eighty (80) parts of a 1,3-butylene glycol product was produced from the bottom of the product column F by the same method as in Example 1 except that the reflux ratio of the dehydration column A was changed to 0.5, that the distilled amount was changed to 42 parts, that the reflux ratio of the high boiling point component removal column C was changed to 0.02, that the reflux ratio of the product column F was changed to 0.05, and that the distilled amount was changed to 20 parts. The produced 1,3-butylene glycol product had an initial boiling point of 193.2° C., a dry point of 210.3° C., a water concentration of 0.6 wt. %, an area ratio of 1,3-butylene glycol of 98.3%, a total area ratio of impurity peaks shorter in retention time than 1,3-butylene glycol of 0.2%, a total area ratio of impurity peaks longer in retention time than 1,3-butylene glycol of 1.5%, an acetaldehyde content of 5 ppm, and a crotonaldehyde content of 4 ppm. The potassium permanganate test value was 0 minutes. The 1,3-butylene glycol recovery ratio in the product column F was 80%.

Comparative Example 2

Eighty (80) parts of a 1,3-butylene glycol product was produced from the bottom of the product column F by the same method as in Example 1 except that the charged composition in the dehydration column A was changed, the reflux ratio and the distilled amount were changed to 0.5 and 32 parts, respectively, that the reflux ratio of the high boiling point component removal column C was changed to 0.02, that the reflux ratio of the product column F was changed to 0.05, and that the distilled amount was changed to 20 parts. The produced 1,3-butylene glycol product had an initial boiling point of 199.0° C., a dry point of 210.1° C., a water concentration of 0.4 wt. %, an area ratio of 1,3-butylene glycol of 98.5%, a total area ratio of impurity peaks shorter in retention time than 1,3-butylene glycol of 0.1%, a total area ratio of impurity peaks longer in retention time than 1,3-butylene glycol of 1.4%, an acetaldehyde content of 4 ppm, and a crotonaldehyde content of 2 ppm. The potassium permanganate test value was 5 minutes. The 1,3-butylene glycol recovery ratio in the product column F was 80%.

Comparative Example 3

Seventy (70) parts of a 1,3-butylene glycol product was produced from the bottom of the product column F by the same method as in Example 1 except that the charged composition in the dehydration column A was changed, the reflux ratio and the distilled amount were changed to 0.5 and 32 parts, respectively, that the reflux ratio of the high boiling point component removal column C was changed to 0.02, that the reflux ratio of the product column F was changed to 0.05, and that the distilled amount was changed to 30 parts. The produced 1,3-butylene glycol product had an initial boiling point of 203.0° C., a dry point of 210.2° C., a water concentration of 0.2 wt. %, an area ratio of 1,3-butylene glycol of 98.4%, a total area ratio of impurity peaks shorter in retention time than 1,3-butylene glycol of 0.1%, a total area ratio of impurity peaks longer in retention time than 1,3-butylene glycol of 1.5%, an acetaldehyde content of 2 ppm, and a crotonaldehyde content of 1.3 ppm. The potassium permanganate test value was 30 minutes. The 1,3-butylene glycol recovery ratio in the product column F was 70%.

Comparative Example 4

Eighty (80) parts of a 1,3-butylene glycol product was produced from the bottom of the product column F by the same method as in Example 1 except that the charged composition in the dehydration column A was changed, the distilled amount was changed to 23 parts, that the reflux ratio of the high boiling point component removal column C was changed to 0.02, that the reflux ratio of the product column F was changed to 0.1, and that the distilled amount was changed to 20 parts. The produced 1,3-butylene glycol product had an initial boiling point of 203.1° C., a dry point of 209.5° C., a water concentration of 0.2 wt. %, an area ratio of 1,3-butylene glycol of 98.8%, a total area ratio of impurity peaks shorter in retention time than 1,3-butylene glycol of 0.1%, a total area ratio of impurity peaks longer in retention time than 1,3-butylene glycol of 1.1%, an acetaldehyde content of 2 ppm, and a crotonaldehyde content of 1.3 ppm. The potassium permanganate test value was 30 minutes. The 1,3-butylene glycol recovery ratio in the product column F was 80%.

Gas Chromatographic Analysis

A gas chromatographic analysis of the target 1,3-butylene glycol product was performed under the conditions below. A chromatogram of the gas chromatographic analysis of the 1,3-butylene glycol product in Example 12 is shown in FIG. 2 . In addition, a chromatogram of the gas chromatographic analysis of the 1,3-butylene glycol product in Comparative Example 2 is shown in FIG. 3 .
The conditions for the gas chromatographic analysis are as follows:
Analytical Instrument: Shimadzu GC 2010
Analytical Column: column with dimethylpolysiloxane as a stationary phase (a length of 30 m, an inner diameter of 0.25 mm, and a film thickness of 1.0 μm) (Agilent J&W GC column—DB-1, available from Agilent Technologies Japan, Ltd.)
Heating conditions: heating from 80° C. to 120° C. at 5° C./min. then heating again to 160° C. at 2° C./min and maintaining for 2 minutes, and further heating to 230° C. at 10° C./min and maintaining at 230° C. for 18 minutes
Sample Introduction and Temperature: split sample introduction, 250° C.
Gas Flow Rate of Split and Carrier Gas: 23 mL/min, helium
Column Gas Flow Rate and Carrier Gas: 1 mL/nin, helium
Detector and Temperature: a flame ionization detector (FID), 280° C.
Injection Sample: 0.2 μL of a 80 wt. % 1,3-butylene glycol product aqueous solution

Measurement of Initial Boiling Point and Dry Point

Measurement was made according to the test method specified in the normal pressure distillation test method of JIS K2254 “Petroleum products—distillation test method”.

Measurement of Water Content

Measurement was made using a Karl Fischer water content measurement instrument.

GC-MS Analysis

Analytical Instrument: Agilent 6890A-GC/5973A-MSD

Analytical Column: a column with dimethylpolysiloxane as a stationary phase, having a length of 30 m, an inner diameter of 0.25 mm, and a film thickness of 1.0 μm
Heating conditions: heating from 80° C. to 120° C. at 5° C./min, then heating again to 160° C. at 2° C./min and maintaining for 2 minutes, and further heating to 230° C. at 10° C./min and maintaining at 230° C. for 18 minutes
Sample Introduction Temperature: 250° C.
Carrier Gas: helium
Column Gas Flow Rate; 1 mL/min
Ion source temperature: EI 230° C., CI 250° C.
Q Pole temperature: 150° C.
Sample: subjected to analysis as it was

Potassium Permanganate Test

In the present specification, the potassium permanganate test value (PMT) is a value measured in accordance with the visual colorimetric procedure of JIS K1351 (1993).

Color Aging Test 1

The target 1,3-butylene glycol product was placed in a wide-mouth bottle, the bottle was stoppered tightly and kept in a constant temperature oven set at 180° C. for 3 hours. A Hazen color number (APHA) of the 1,3-butylene glycol product after the 1,3-butylene glycol product had been kept at 180° C. for 3 hours was measured using a color difference meter (“ZE6000” available from Nippon Denshoku Industries Co., Ltd.) and a quartz cell with an optical path length of 10 mm. The Hazen color number (APHA) of the 1,3-butylene glycol product prior to the test was similarly measured.

Color Aging Test 2

The target 1,3-butylene glycol product was placed in a wide-mouth bottle, and the bottle was stoppered tightly and kept in a constant temperature oven set at 100° C. for 75 days. A Hazen color number (APHA) of the 1,3-butylene glycol product after the 1,3-butylene glycol product had been kept at 100° C. for 75 days was measured using a color difference meter (“ZE6000” available from Nippon Denshoku Industries Co., Ltd.) and a quartz cell with an optical path length of 10 mm.

Water Added Heating Test (Acid Concentration Analysis)

The target 1,3-butylene glycol product adjusted to a 90 wt. % aqueous solution and then kept at 100° C. for 1 week was used as a sample for an acid concentration analysis performed according to the technique below. In addition, the 1,3-butylene glycol product prior to the test was also subjected to acid concentration analysis by the following technique.

Acid Concentration Analysis

The sample was measured using an automatic potentiometric titrator (AT-510 available from Kyoto Electronics Manufacturing Co., Ltd.). First, 50 g of the sample was diluted with 50 g of distilled water and titrated with 0.01 N aqueous sodium hydroxide solution from a burette with stirring until the titration was automatically stopped at the endpoint. Then, the acid concentration (acid content) in terms of acetic acid was calculated based on the following equation.
Acid concentration (wt. %)=titration volume (mL)×F×A×(100/sample amount (g))
F: 1.0 (factor of the 0.01 N aqueous sodium hydroxide solution)
A: 0.0006 (grams of acetic acid corresponding to 1 mL of the aqueous sodium hydroxide solution)

Odor Test

The target 1,3-butylene glycol product (100 mL) was placed in a wide-mouth reagent bottle (internal volume: 100 mL), and the bottle was stoppered tightly and allowed to stand at room temperature for a while (about 120 minutes). Then, the stopper was opened, the content was transferred to a 300-mL wide-mouth beaker, and 100 mL of pure water was added into the beaker to make a total of 200 mL. The wide-mouth beaker was shaken manually to stir the content, and the odor was then immediately smelled and scored according to the following evaluation. The same odor test was performed also on the sample after the coloration-over-time test 1, and the sample after the water added heating test.
1: Odor is not sensed
2: Slightly odorous
3: Odor is clearly sensed

Considerations of Results

The results of the comparative examples and the examples are shown in Table 1, Table 2, and Table 3.

TABLE 1

	Comparative	Comparative	Comparative	Comparative	Example	Example	Example
	Example 1	Example 2	Example 3	Example 4	1	2	3

Charge into	Part	100	100	←	100	100	←	←
dehydration	1,3 BG GC area %	56	66	←	76	56	←	←
column A	Water wt. %	40	30	←	20	40	←	←
	AD ppm	130	145	←	155	130	←	←
	CR ppm	89	110	←	117	89	←	←
	Low boiling substance	3	3	←	3	3	←	←
	GC area %
	High boiling substance	1	1	←	1	1	←	←
	GC area %
Reflux ratio of		0.5	0.5	←	1	1	50	50
dehydration
columu A
Distillate from	Part	42	32	←	23	43	43	43
dehydration
column A
1,3 BG	%	99.3	99.8	←	99.8	99.6	99.9 or	99.6
recovery ratio							greater
Charge into	Part	100	←	←	←	←	←	←
high boiling	1,3 BG GC area %	96.6	97.4	←	97.9	97.4	97.9	←
point	Water wt.%	1.2	1.1	←	0.7	0.9	0.2	←
component	AD ppm	63	48	←	39	20	9	9
removal	CR ppm	45	37	←	23	19	12	9
column C	Low boding substance	1.6	1.1	←	0.8	0.8	0.3	←
	GC area %
	High boiling substance	1.8	1.5	←	1.3	1.8	1.8	←
	GC area %
High boiling	Reflux ratio	0.02	0.02	0.02	0.02	0.05	0.05	0.05
point	Distillation extraction	80	80	80	80	80	80	80
component	part
removal	Bottom extraction part	2020		20	20	20	20	20
column C	Recycle	Absent	Absent	Absent	Absent	Absent	Absent	Absent
	1,3 BG recovery	81	81	81	81	82	81	81
	ratio %
Charge into	Part	100	100	←	100	100	←	100
product	1,3 BG GC area %	97.8	98.3	←	98.6	99.0	99.1	99.2
column F	Water wt.%	1.3	1.2	←	0.8	1	0.3	0.3
	AD ppm	45	39	←	38	20	9	9
	CR ppm	20	12	←	139		6	6
	Low boiling substance	1.0	0.6	←	0.6	0.4	0.3	0.3
	GC area %
	High boiling substance	1.2	1.1	←	0.8	0.6	0.6	0.5
	GC area %
Reflux ratio of		0.05	0.05	0.05	0.1	0.5	0.5	10
product
column F
Distillation	Part	20	20	30	20	10	10	1
column F
from product	Recycle	Absent	Absent	Absent	Absent	Absent	Absent	Absent
Bottom	Part	80	80	70	80	90	90	99
(product) from	1,3 BG GC area %	98.3	98.5	98.4	98.8	99.2	99.3	99.5
product	Water wt. %	0.6	0.4	0.2	0.2	0.2	0.1	0.1
column F	AD ppm	5	4	2	2	1.5	0.7	1
	CR ppm	4	2	1.3	1.3	0.9	0.7	0.7
	Low boiling substance	0.2	0.1	0.1	0.1	0.08	0.05	0.05
	GC area %
	High boiling substance	1.5	1.4	1.5	1.1	0.7	0.7	0.5
	GC area %
	Initial boiling point ° C.	193.2	199.0	203.0	203.1	203.3	206.7	206.7
	Dry point ° C.	210.3	210.1	210.2	209.5	209	208.9	208.8
	PMT min	0	5	30	30	35	45	40
	1,3 BG recovery	81	80	70	80	90	90	99 or
	ratio %							greater

		Example	Example	Example	Example	Example	Example	Example
		4	5	6	7	8	9	10

Charge into	Part	100	←	←	←	←	←	←
dehydration	1,3 BG GC area %	66	←	←	←	←	←	←
column A	Water wt. %	30	←	←	←	←	←	←
	AD ppm	145	←	←	←	←	←	←
	CR ppm	110	←	←	←	←	←	←
	Low boiling substance	3	←	←	←	←	←	←
	GC area %
	High boiling substance	1	←	←	←	←	←	←
	GC area %
Reflux ratio of		2	10	20	20	20	50	100
dehydration
columu A
Distillate from	Part	33	33	33	33	33	33	33
dehydration
column A
1,3 BG	%	99.9	99.9 or	99.9 or	99.9 or	99.9 or	99.9 or	99.9 or
recovery ratio			greater	greater	greater	greater	greater	greater
Charge into	Part	←	←	←	←	←	←	←
high boiling	1,3 BG GC area %	98.2	98.3	98.3	98.3	98.3	98.3	98.4
point	Water wt. %	0.5	0.1	0.08	0.08	0.08	0.03	0.02
component	AD ppm	38	18	13	13	13	5	4
removal	CR ppm	30	12	11	11	11	5	3
column C	Low boding substance	0.3	0.2	0.2	0.2	0.2	0.2	0.1
	GC area %
	High boiling substance	1.5	1.5	1.5	1.5	1.5	1.5	1.5
	GC area %
High boiling	Reflux ratio	0.05	0.05	0.05	0.05	0.05	0.05	0.05
point	Distillation extraction	80	80	80	80	80	80	80
component	part
removal	Bottom extraction part	20	20	20	20	20	20	20
column C	Recycle	Absent	Absent	Absent	Absent	Absent	Absent	Absent
	1,3 BG recovery	81	81	81	81	81	81	81
	ratio %
Charge into	Part	100	←	←	←	←	←	←
product	1,3 BG GC area %	99.2	99.3	99.3	99.3	99.3	99.3	99.4
column F	Water wt.%	0.6	0.3	0.2	0.2	0.2	0.1	0.08
	AD ppm	29	16	10	11	9	3	2
	CR ppm	13	5	3	3	3	2	1
	Low boiling substance	0.3	0.2	0.2	0.2	0.2	0.2	0.1
	GC area %
	High boiling substance	0.5	0.5	0.5	0.5	0.5	0.5	0.5
	GC area %
Reflux ratio of		0.5	0.5	2	100	500	2	2
product
column F
Distillation	Part	10	10	1	1	1	1	1
column F
from product	Recycle	Present	Present	Present	Present	Present	Present	Present
Bottom	Part	90	90	99	99	99	99	99
(product) from	1,3 BG GC area %	99.4	99.4	99.4	99.5	99.5	99.4	99.5
product	Water wt. %	0.2	0.1	0.1	0.003	0.002	0.05	0.04
column F	AD ppm		2	1.1	1	0.2	less than	0.3	less than
						0.2		0.2
	CR ppm	1	0.7	0.6	0.1	less than	0.2	less than
						0.1		0.1
	Low boiling substance	0.04	0.03	0.07	0.004	0.003	0.06	0.03
	GC area %
	High boiling substance	0.6	0.6	0.5	0.5	0.5	0.5	0.5
	GC area %
	Initial boiling point ° C.	203.8	206.7	206.8	208.4	208.4	207.5	207.2
	Dry point ° C.	208.9	208 9	208.8	208.8	208.8	208.8	208.8
	PMT min	30	40	40	55	60	50	55
	1,3 BG recovery	99 or	99 or	99 or	99 or	99 or	99 or	99 or
	ratio %	greater	greater	greater	greater	greater	greater	greater

TABLE 2

	Example	Example	Example	Example	Example	Example	Example	Example	Example
	11	12	13	14	15	16	17	18	19

Charge into	Part	100	←	←	100	←	←	←	←	←
dehydration	1,3 BG GC	76	←	←	66	←	←	←	←	←
column A	area %
	Water wt. %	20	←	←	30	←	←	←	←	←
	AD ppm	155	←	←	145	←	←	←	←	←
	CR ppm	117	←	←	110	←	←	←	←	←
	Low boiling	3	←	←	3	←	←	←	←	←
	substance
	GC area %
	High boiling	1	←	←	←	←	12	←	←	←
	substance
	GC area %
Reflux ratio of		2	10	100	10	10	10	to	to	10
dehydration
column A
Distillate from	Part	23	23	23	33	33	33	33	33	23
dehydration
column A


1,3 BG	%	99.8	99.9 or	99.9 or	99.8	99.8	99.8	99.8	99.8	99.8
recovery ratio			greater	greater
Charge into	Part	100	←	←	←	←	←	←	←	←
high boiling	1,3 BG GC	98.4	98.5	98.6	98.3	←	98.1	98.3	←	←
point	area %
component	Water wt. %	0.1	0.08	0.01	0.1	←	0.1	0.1	←	←
removal	AD ppm	29	15	2	18	←	18	18	←	←
column C	CR ppm	21	8	1	12		12	12	←	←
	Low boiling	0.3	0.2	0.1	0.2	←	0.2	0.2	←	←
	substance
	GC area %
	High boiling	1.3	1.3	1.3	1.5		1.7	1.5	←	←
	substance
	GC area %
High boiling	Reflux ratio	0.05	0.05	0.05	0.1	0.5	0.5	0.5	1	2
point	Distillation	80	80	80	90	90	90	95	95	95
component	extraction part
removal	Bottom
	20	20	20	10	10	10	5	5	5
column C	extraction part
	Recycle	Absent	Absent	Absent	Absent	Absent	Present	Absent	Absent	Absent
	1,3 BG recovery	81	81	81	91	91	99.9 or	96	96	96
	ratio %						greater
Charge into	Part	100	←	←	100	100	100	100	100	100
product	1,3 BG GC	99.3	99.4	99.5	99.4	99.6	99.5	99.5	99.7	99.7
column F	area %
	Water wt. %	0.3	0.1	0.09	0.3	0.3	0.3	0.3	0.3	0.3
	AD ppm	22	12	1	10	9	10	10	9	8
	CR ppm	14	5	0.7	5	6	6	5	5	5
	Low boiling	0.3	0.2	0.1	0.2	0.2	0.2	0.2	0.2	0.2
	substance
	GC area %
	High boiling	0.4	0.4	0.4	0.4	0.3	0.3	0.3	0.1	0.09
	substance
	GC area %
Reflux ratio of		1	2	2	1	1	1	1	1	1
product
column F
Distillate from	Part	10	1	1	10	10	10	10	10	10
product	Recycle	Present	Present	Present	Present	Present	Present	Present	Present	Present
column F
Bottom	Part	90	99	99	90	90	90	90	90	90
(product) from	1,3 BG GC	99.4	99.4	99.5	99.5	99.6	99.6	99.6	99.9	99.9
product	area %
column F	Water wt. %	0.06	0.05	0.04	0.05	0.05	0.05	0.05	0.05	0.05
	AD ppm	1.6	1	less than	0.9	0.8	0.8	0.9	0.8	0.9
				0.2
	CR ppm	1	0.8	less than	0.7	0.6	0.6	0.5	0.5	0.4
				0.1
	Low boiling	0.09	0.07	0.05	0.02	0.02	0.02	0.02	0.02	0.02
	substance
	GC area %
	High boiling	0.5	0.5	0.5	0.5	0.2	0.4	0.4	0.1	0.09
	substance
	GC area %
	Initial boiling	207.3	207.5	207.2	207.5	207.5	207.5	207.5	207.5	207.5
	point ° C.
	Dry point ° C.	208.9	208.9	208.9	208.8	208.6	208.8	208.8	208.6	208.5
	PMT min	35	40	60	45	45	45	45	45	45
	1,3 BG recovery	90	99 or	99 or	99.9 or	99.9 or	99.9 or	99.9 or	99.9 or	99.9 or
	ratio %		greater	greater	greater	greater	greater	greater	greater	greater

			Example	Example	Example	Example	Example	Example	Example	Example
			20	21	22	23	24	25	26	27

	Charge into	Part	←	←	100	100	100	100	100	100
	dehydration	1,3 BG GC	←	←	56	76	9	66	67	69
	column A	area %
		Water wt. %	←	←	40	20	90	30	30	30
		AD ppm	←	←	130	155	85	970	145	3
		CR ppm	←	←	89	117	71	390	110	1
		Low boiling	←	←	3	3	0.4	3	3	1
		substance
		GC area %
		High boiling	←	←	1	1	0.1	1	1	0.5
		substance
		GC area %
	Reflux ratio of		10	10	0.5	100	20	2	0.3	10
	dehydration
	column A
	Distillate from	Part	33	33	42	23	91	33	32	32
	dehydration
	column A
	1,3 BG	%	99.8	99.8	99.3	99.9 or	99.0	99.9 or	99.8	99.9 or
	recovery ratio					greater		greater		greater
	Charge into	Part	←	←	100		100	100	100	4
	high boiling	1,3 BG GC	←	←	96.6	98.6	97.5	98.2	96.7	99.1
	point	area %
	component	Water wt. %	←	←	1.2	0.01	3	0.5	1.3	0.1
	removal	AD ppm	←	←	63	2	9	22.1	61	0.3
	column C	CRppm	←	←	45	1	4	128	48	0.2
		Low boiling	←	←	1.6	0.1	1.1	0.3	1.8	0.1
		substance
		GC area %
		High boiling	←	←	1.8	1.3	1.4	1.5	1.5	0.8
		substance
		GC area %
	High boiling	Reflux ratio	5	20	0.1	1	1	0.05	0.05	1
	point	Distillation	95	95	90	90	90	80	80	95
	component	extraction part
	removal	Bottom	5	5	10	10	10	20	20	5
	column C	extraction part
		Recycle	Absent	Absent	Absent	Absent	Absent	Absent	Absent	Absent
		1,3 BG recovery	96	96	92	91	91	81	81	96
		ratio %
	Charge into	Part	too	100	100	—	100	100	100	too
	product	1,3 BG GC	99.7	99.7	98.7	—	98.7	99.2	97.6	99.7
	column F	area %
		Water wt. %	0.3	0.3	1.2	—	3	0.7	1.4	0.3
		AD ppm	8	9	43	—	7	205	54	0.3
		CR ppm	4	5	17	—	3	110	38	0.2
		Low boiling	0.2	0.2	0.9	—	0.8	0.3	1.8	0.1
		substance
		GC area %
		High boiling	0.07	0.06	0.4	—	0.5	0.5	0.6	0.2
		substance
		GC area %
	Reflux ratio of		1	1	5	—	10	10	20	1
	product
	column F
	Distillate from	Part	10	10	10	—	10	10	10	10
	product	Recycle	Present	Present	Present	—	Present	Present	Present	Present
	column F
	Bottom	Part	90	90	96	—	90	96	90	90
	(product) from	1,3 BG GC	99.9	99.9	99.4	99.5	99.4	99.4	99.3	99.8
	product	area %
	column F	Water wt. %	0.05	0.05	0.1	0.09	0.1	6.62	0.01	6.65
		AD ppm	0.9	0.8	1.1	1.5	0.3	1.2	0.5	less than
										0.2
		CR ppm	0.4	0.3	0.4	1	0.2	1.1	0.4	less than
										6.1
		Low boiling	0.02	0.02	0.1	0.1	0.02	0.004	0.03	6.01
		substance
		GC area %
		High boiling	0.08	0.07	0.5	0.4	0.6	0.6	0.7	0.2
		substance
		GC area %
		Initial boiling	207.6	207.6	206.8	206.9	206.7	208.0	207.8	207.6
		point ° C.
		Dry point ° C.	208.5	208.4	208.8	208.8	208.9	208.9	208.9	208.6
		PMT min	45	45	45	35	50	35	45	65
		1,3 BG recovery	99.9 or	99.9 or	99.9 or	—	99.9 or	99 or	99 or	99.9 or
		ratio %	greater	greater	greater		greater	greater	greater	greater

TABLE 3

	Compar-	Compar-
	ative	ative
	Exam-	Exam-	Exam-	Exam-	Exam-
	ple 1	ple 2	ple 1	ple 5	ple 7

1,3 BG GC area %	98.3	98.5	99.2	99.4	99 5
Water wt. %	0.6	0.4	0.2	0.1	0.003
AD ppm	5	4	1.5	1.1	0.2
CR ppm	4	2	0.9	0.7	0.1
Low boiling substance GC area %	0.2	0.1	0.08	0.03	0.004
High boiling substance GC area %	15	1.4	0.7	0.6	0.5
Initial boiling point ° C.	193.2	199	203.3	206.7	208.4
Dry point ° C.	210.3	210.1	209	208.9	208.9
PMT min	0	5	35	40	55
Methyl vinyl ketone ppm	11	10	6	2	less than 0.2
Acetone ppm	10	9	5	2	less than 0.2
Butylaldehyde ppm	9	8	5	2	less than 0.2
Acetaldol ppm	10	10	6	2	less than 0.2
Compound ppm of Formula (1)	11	10	6	1.4	less than 0.2
Compound ppm of Formula (2)	9	8	5	1.1	0.5
Compound ppm of Formula (3)	9	8	4	1	0.4
Compounds ppm of Formula (4) +	8	8	4	0.9	0.3
Formula (5)
APHA before coloration test	7	7	4	2	1
Odor before coloration test	2	2	1	1	l
Odor after coloration test 1	3	2	2	1	1
APHA of coloration test 1	85	79	25	17	10
APHA of coloration test 2	51	43	12	7	3
Acid content (ppm) before water	11	11	6	4	2
added heating test
Odor before water added heating test	2	2	1	1	1
Acid content (ppm) after water added	27	23	9	5	2
heating test
Odor after water added heating test	3	3	2	1	1

	Exam-	Exam-	Exam-	Exam-	Exam-
	ple 12	ple 18	ple 24	ple 26	ple 27

1,3 BG GC area %	99.4	99.9	99.3	99.3	99.8
Water wt. %	0.05	0.05	0.03	0.03	0.05
AD ppm	1	0.8	0.5	0.5	less than 0.2
CR ppm	0.8	0.5	0.4	0.4	less than 0.1
Low boiling substance GC area %	0.07	0.02	0.2	0.03	0.01
High boiling substance GC area %	0.5	0.1	0.6	0.7	0.2
Initial boiling point ° C.	207.5	207.5	206.7	207.8	207 6
Dry point ° C.	208.9	208.6	208.9	208.9	208.6
PMT min	40	45	50	45	65
Methyl vinyl ketone ppm	0.3	0.9	less than 0.2	3	less than 0.2
Acetone ppm	0.2	0.8	less than 0.2	2	less than 0.2
Butylaldehyde ppm	0.3	07	less than 0.2	2	less than 0 2
Acetaldol ppm	less than 0.2	0.5	less dian 0.2	2	less than 0.2
Compound ppm of Formula (1)	less than 0 2	0.8	less than 0.2	2	less than 0.2
Compound ppm of Formula (2)	0.4	less than 0.2	0.6	0.3	less than 0.2
Compound ppm of Formula (3)	0.5	less than 0.2	0.7	0.5	less than 0 2
Compounds ppm of Formula (4) +	0.3	less than 0.2	0.4	0.2	less than 0.2
Formula (5)
APHA before coloration test	2	2	1	2	1
Odor before coloration test	1	1	1	1	1
Odor after coloration test 1	1	]	1	1	1
APHA of coloration test 1	12	13	11	18	7
APHA of coloration test 2	4	5	3	8	2
Acid content (ppm) before water	3	3	2	4	1
added heating test
Odor before water added heating test	3	1	1	1	1
Acid content (ppm) after water added	3	3	2	4	1
heating test
Odor after water added heating test	1	1	1	1	1

From Comparative Example 1, Comparative Example 2, Example 1, Example 5, and Example 7, it can be seen that, for acetaldehyde, crotonaldehyde, and other impurities detected by the gas chromatographic analysis (quantification limit: 10 ppm), and methyl vinyl ketone, acetone, butylaldehyde, acetaldol, the compound represented by Formula (1), the compound represented by Formula (2), the compound represented by Formula (3), the compound represented by Formula (4), and the compound represented by Formula (5) detected by the GC-MS analysis, the lower contents resulted in better long-term storage stability in terms of coloration, acid concentration and odor.
The same applies to Examples 7, 12, and 18. From Examples 12 and 18, the reduction in contents of methyl vinyl ketone, acetone, butylaldehyde, acetaldol, and the compound represented by Formula (1) having a boiling point less than that of 1,3 BG and the reduction in contents of the compound represented by Formula (2), the compound represented by Formula (3), the compound represented by Formula (4), and the compound represented by Formula (5) have a boiling point higher than that of 1,3 BG were both effective for long-term stability. However, total reduction in contents of these impurities as well as in contents of acetaldehyde, crotonaldehyde, and other impurities detected by the gas chromatographic analysis (quantification limit: 10 ppm) is most effective for long-term stability of the quality of the 1.3 BG product, and the stability of the product quality is significantly better in Example 7. Note that there was no clear correlation between the contents of the impurities detected by the gas chromatographic analysis other than 1,3 BG (the quantification limit of around 10 ppm) and contents of impurities, which were less than 10 ppm, ranging from methyl vinyl ketone to the compound represented by Formula (5) detected by the GC-MS analysis. This is thought to result from slight variation in concentration of each component depending on the reaction conditions and the individual distillation conditions.
Example 24 was a case where the water content of the charged liquid into the dehydration column was extremely high, but shows the same tendency as described above. The relationship between the overall behavior of the impurities and the APHA and acid concentration (acid content) showed the same tendency as in Example 7.
In Example 26, it can be seen that, while the concentration of 1,3-butylene glycol in the charged liquid into the product column was reduced, the quality of the 1,3 BG product could be maintained by maintaining a relatively high reflux ratio of the product column.
It can be seen, from Examples 18 and 27, that the quality of the 1,3 BG product was further improved by increasing the hydrogen addition pressure, totally reacting the unsaturated compounds such as aldehyde and olefin and acetals in the reaction system, and adjusting the distillation conditions in each distillation column.
As a summary of the above, configurations and variations of the present disclosure are described below.
[1] A 1,3-butylene glycol product in which at least one of eight contents: a content of methyl vinyl ketone, a content of acetone, a content of butylaldehyde, a content of acetaldol, a content of a compound represented by Formula (1) below, a content of a compound represented by Formula (2) below, a content of a compound represented by Formula (3) below, and a total content of a compound represented by Formula (4) below and a compound represented by Formula (5) below, is less than 8 ppm (or 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).
[2] The 1,3-butylene glycol product according to [1], wherein at least two (or three, four, five, six, seven, or eight) contents of the eight contents: the content of methyl vinyl ketone, the content of acetone, the content of butylaldehyde, the content of acetaldol, the content of the compound represented by Formula (1) below, the content of the compound represented by Formula (2) below, the content of the compound represented by Formula (3) below, and the total content of the compound represented by Formula (4) below and the compound represented by Formula (5) below, are each less than 8 ppm (or 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).
[3] The 1,3-butylene glycol product according to [1] or [2], wherein at least four (four, five, six, seven, or eight) contents of the eight contents: the content of methyl vinyl ketone, the content of acetone, the content of butylaldehyde, the content of acetaldol, the content of the compound represented by Formula (1) below, the content of the compound represented by Formula (2) below, the content of the compound represented by Formula (3) below, and the total content of the compound represented by Formula (4) below and the compound represented by Formula (5) below, are each less than 8 ppm (or 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).
[4] The 1,3-butylene glycol product according to any one of [1] to 131, wherein a sum of the content of methyl vinyl ketone, the content of acetone, the content of butylaldehyde, the content of acetaldol, the content of the compound represented by Formula (1), the content of the compound represented by Formula (2), the content of the compound represented by Formula (3), and the content of the compound represented by Formula (4) and the content of the compound represented by Formula (5) is less than 71 ppm (or 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 18 ppm or less, 16 ppm or less, 14 ppm or less, 12 ppm or less, ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).
[5] The 1,3-butylene glycol product according to any one of [1] to [4], wherein a sum of the content of methyl vinyl ketone, the content of acetone, the content of butylaldehyde, the content of acetaldol, and the content of the compound represented by Formula (1) is less than 47 ppm (or, 40 ppm or less, 30 ppm or less, 25 ppm or less, 20 ppm or less, 18 ppm or less, 16 ppm or less, 14 ppm or less, 12 ppm or less, ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less), and a sum of the content of the compound represented by Formula (2), the content of the compound represented by Formula (3), the content of the compound represented by Formula (4), and the content of the compound represented by Formula (5) is less than 24 ppm (or ppm or less, 18 ppm or less, 16 ppm or less, 14 ppm or less, 13 ppm or less, 12 ppm or less, 11 μm or less, 10 ppm or less, 9 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).
[6] The 1,3-butylene glycol product according to any one of [1] to [5], wherein at least the content of acetaldol is less than 8 ppm (or 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).
[7] The 1,3-butylene glycol product according to any one of [1] to [6], wherein at least the content of the compound represented by Formula (3) is less than 8 ppm (or 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).
[8] The 1,3-butylene glycol product according to any one of [1] to [7], wherein a total content of methyl vinyl ketone, acetone, and butylaldehyde is 24 ppm or less (or 20 ppm or less, 18 ppm or less, 16 ppm or less, 14 ppm or less, 12 ppm or less, 11 ppm or less, 10 ppm or less, 9 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).
[9] The 1,3-butylene glycol product according to any one of [1] to [8], wherein a total content of the compound represented by Formula (1), the compound represented by Formula (2), the compound represented by Formula (4), and the compound represented by Formula (5) is 24 ppm or less.
[10] The 1,3-butylene glycol product according to any one of [1] to [9], which has a content of acetaldehyde of less than 4 ppm (or less than 2 ppm, 1.8 ppm or less, 1.7 ppm or less, 1.5 ppm or less, 1.4 ppm or less, 1.3 ppm or less, 1.2 ppm or less, 1.1 ppm or less, 1.0 ppm or less, 0.9 ppm or less, 0.8 ppm or less, 0.7 ppm or less, 0.6 ppm or less, 0.5 ppm or less, 0.3 ppm or less, or 0.2 ppm or less).
[11] The 1,3-butylene glycol product according to any one of [1] to [10], which has a content of crotonaldehyde of less than 2 ppm (or less than 1.2 ppm, 1.0 ppm or less, 0.9 ppm or less, 0.8 ppm or less, 0.7 ppm or less, 0.6 ppm or less, 0.5 ppm or less, 0.4 ppm or less, 0.3 ppm or less, 0.2 ppm or less, or 0.1 ppm or less).
[12] The 1,3-butylene glycol product according to any one of [1] to [11], which has an acid concentration of less than 11 ppm (or 10 ppm or less, 9 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, or 3 ppm or less) in terms of acetic acid, and an acid concentration of less than 23 ppm (or 20 ppm or less, 19 ppm or less, 18 ppm or less, 17 ppm or less, 16 ppm or less, 15 ppm or less, 14 ppm or less, 13 ppm or less, 12 ppm or less, 11 ppm or less, 10 ppm or less, 9 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, or 2 ppm or less) in terms of acetic acid after a 90 wt. % aqueous solution has been kept at 100° C. for 1 week.
[13] The 1,3-butylene glycol product according to any one of [1] to [12], in which an APHA is 6 or less (or 5 or less, 4 or less, 3 or less, or 2 or less), and, after the 1,3-butylene glycol product has been kept at 180° C. for 3 hours in air atmosphere, an APHA is 78 or less (or 65 or less, 60 or less, 55 or less, 50 or less, 45 or less, 40 or less, 35 or less, 30 or less, 25 or less, 20 or less, 18 or less, 15 or less, 14 or less, 13 or less, 12 or less, 11 or less, 10 or less, 9 or less, 8 or less, or 7 or less).
[14] The 1,3-butylene glycol product according to any one of [1] to [13], in which, after the 1,3-butylene glycol product has been kept at 100° C. for 75 days in air atmosphere, an APHA is 42 or less (35 or less, 30 or less, 25 or less, 20 or less, 18 or less, 16 or less, 15 or less, 14 or less, 13 or less, 12 or less, 11 or less, 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, 3 or less, or 2 or less).
[15] The 1,3-butylene glycol product according to any one of [1] to [14], which has an initial boiling point of higher than 203° C. (or 204° C. or higher, 205° C. or higher, 206° C. or higher, 207° C. or higher, or 208° C. or higher), and/or a dry point of 209° C. or lower.
[16] The 1,3-butylene glycol product according to any one of [1] to [15], which has a potassium permanganate test value of 30 minutes or longer (or longer than 30 minutes, 32 minutes or longer, 35 minutes or longer, 40 minutes or longer, 50 minutes or longer, or 60 minutes or longer).
[17] The 1,3-butylene glycol product according to any one of [1] to [16], which has an area ratio (GC area ratio) of a peak of 1,3-butylene glycol of greater than 98.7% (or 98.8% or greater, 98.9% or greater, 99% or greater, 99.1% or greater, 99.2% or greater, 99.3% or greater, 99.4% or greater, 99.5% or greater, 99.6% or greater, 99.7% or greater, or 99.8% or greater), in a gas chromatographic analysis (GC analysis) performed under conditions set forth below,
The conditions for the gas chromatographic analysis are as follows:
Analytical Column: a column with dimethylpolysiloxane as a stationary phase, having a length of 30 m, an inner diameter of 0.25 mm, and a film thickness of 1.0 μm
Heating conditions: heating from 80° C. to 120° C. at 5° C./min, then heating again to 160° C. at 2° C./min and maintaining for 2 minutes, and further heating to 230° C. at 10° C./min and maintaining at 230° C. for 18 minutes
Sample Introduction Temperature: 250° C.
Carrier Gas: helium
Column Gas Flow Rate: 1 mL/min
Detector and Detection Temperature: a flame ionization detector (FID), 280° C.
[18] The 1,3-butylene glycol product according to any one of [1] to [17], wherein a total area ratio of peaks shorter in retention time than the peak of 1,3-butylene glycol is less than 0.3% (or 0.28% or less, 0.25% or less, 0.23% or less, 0.2% or less, 0.17% or less, 0.15% or less, 0.12% or less, 0.1% or less, 0.07% or less, 0.04% or less, 0.03% or less, 0.02% or less, 0.01% or less, 0.007% or less, 0.005% or less, or 0.002% or less) in the gas chromatographic analysis (GC analysis) performed under conditions set forth above.
[19] The 1,3-butylene glycol product according to any one of [1] to [18], wherein a total area ratio of peaks longer in retention time than the peak of 1,3-butylene glycol is less than 1.2% (or 1% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, or 0.1% or less).
[20] The 1,3-butylene glycol product according to any one of [1] to [19], which has a content of water of less than 0.4 wt. % (or 0.3 wt. % or less, 0.2 wt. % or less, 0.1 wt. % or less, 0.07 wt. % or less, 0.05 wt. % or less, 0.03 wt. % or less, 0.02 wt. % or less, 0.01 wt. % or less, or 0.005 wt. % or less).
[21] A moisturizer containing the 1,3-butylene glycol product described in any one of [1] to [20].
[22] The moisturizer according to [21], which has a content of the 1,3-butylene glycol product described in any one of [1] to [20] of 10 wt. % or greater (or 30 wt. % or greater, 50 wt. % or greater, 80 wt. % or greater, or 90 wt. % or greater).
[23] A cosmetic product containing the moisturizer described in [21] or [22].
[24] The cosmetic product according to [23], which has a content of the 1,3-butylene glycol product described in any one of [1] to [20] from 0.01 to 40 wt. % (or from 0.1 to 30 wt. %, from 0.2 to 20 wt. %, from 0.5 to 15 wt. %, or from 1 to 10 wt. %).
[25] The cosmetic product according to [23] or [24], which is a skin cosmetic product, a hair cosmetic, a sunscreen cosmetic product or a make-up cosmetic product.
[26] A method for producing 1,3-butylene glycol to yield purified 1,3-butylene glycol from a reaction crude liquid containing 1,3-butylene glycol,
the method including: performing dehydration including removing water by distillation, removing a high boiling point component including removing a high boiling point component by distillation, and performing product distillation to yield purified 1,3-butylene glycol,
wherein, in a product column for use in the performing product distillation, a 1,3-butylene glycol charged liquid is subjected to distillation, the 1,3-butylene glycol charged liquid having a content of acetaldehyde of 500 ppm or less (or 205 ppm or less, 200 ppm or less, 150 ppm or less, 120 ppm or less, 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, or less than 2 ppm), a content of crotonaldehyde of 200 ppm or less (or 150 ppm or less, 130 ppm or less, 110 ppm or less, 100 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, or less than 1 ppm), a content of water of 0.7 wt. % or less (or 0.6 wt. % or less, 0.5 wt. % or less, 0.4 wt. % or less, 0.3 wt. % or less, 0.2 wt. % or less, or 0.1 wt. % or less), and a concentration of 1,3-butylene glycol of 97.6 area % or greater (or 97.8 area % or greater, 98 area % or greater, 98.2 area % or greater, 98.4 area % or greater, 98.6 area % or greater, 98.8 area % or greater, 99 area % or greater, 99.1 area % or greater, 99.2 area % or greater, 99.3 area % or greater, 99.4 area % or greater, 99.5 area % or greater, 99.6 area % or greater, 99.7 area % or greater, 99.8 area % or greater, or 99.9 area % or greater) according to a gas chromatographic analysis performed under conditions set forth below; and the distillation is performed under a condition that a reflux ratio is 0.3 or greater (or 0.4 or greater, 0.5 or greater, 1 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater, 6 or greater, 7 or greater, 8 or greater, 9 or greater, 10 or greater, 20 or greater, 50 or greater, 400 or greater, or 500 or greater).
The conditions for the gas chromatographic analysis are as follows:
Analytical Column: a column with dimethylpolysiloxane as a stationary phase, having a length of 30 m, an inner diameter of 0.25 mm, and a film thickness of 1.0 μm
Heating conditions: heating from 80° C. to 120° C. at 5° C./min then heating again to 160° C. at 2° C./min and maintaining for 2 minutes, and further heating to 230° C. at 10° C./min and maintaining at 230° C. for 18 minutes
Sample Introduction Temperature: 250° C.
Carrier Gas: helium
Column Gas Flow Rate: 1 mL/min
Detector and Detection Temperature: a flame ionization detector (FID), 280° C.
[27] The method for producing 1,3-butylene glycol according to [26], wherein the distillation rate in the product column is less than 30 wt. % (or 29 wt. % or less, 28 wt. % or less, 27 wt. % or less, 26 wt. % or less, 25 wt. % or less, 24 wt. % or less, 23 wt. % or less, 22 wt. % or less, 21 wt. % or less, 20 wt. % or less, 19 wt. % or less, 18 wt. % or less, 17 wt. % or less, 16 wt. % or less, 15 wt. % or less, 12 wt. % or less, 10 wt. % or less, 8 wt. % or less, 5 wt. % or less, 3 wt. % or less, 2 wt. % or less, 1 wt. % or less, 0.8 wt. % or less, 0.6 wt. % or less, or 0.4 wt. % or less).
[28] The method for producing 1,3-butylene glycol according to [26] or [27], wherein at least a portion of a distillate of the product column is recycled to a step before the performing product distillation (for example, dehydration, dealcoholization, low boiling point component removal, or a step before these steps).
[29] The method for producing 1,3-butylene glycol according to [28], wherein an amount of the distillate of the product column, which is recycled to the step prior to the product distillation, is 0.01 wt. % or greater (or 0.05 wt. % or greater, 0.1 wt. % or greater, 0.5 wt. % or greater, 1 wt. % or greater, 1.5 wt. % or greater, 2 wt. % or greater, 3 wt. % or greater, 4 wt. % or greater, 5 wt. % or greater, 7 wt. % or greater, 10 wt. % or greater, or 20 wt. % or greater) and less than 30 wt. % with respect to a charged amount into the product column.
[30] The method for producing 1,3-butylene glycol according to any one of [26] to [29], wherein a recovery ratio of 1,3-butylene glycol in the product column is greater than 80% (or 85% or greater, 90% or greater, 95% or greater, or 99% or greater).
[31] The method for producing 1,3-butylene glycol according to any one of [26] to [30], wherein, in a high boiling point component removal column for use in the removing a high boiling point component, a charged liquid containing 1,3-butylene glycol is subjected to distillation, the charged liquid having a content of acetaldehyde of 500 ppm or less (or 205 ppm or less, 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, ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, less than 2 ppm, or less than 1 ppm), a content of crotonaldehyde 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), a content of water of 3 wt. % or less (or 2 wt. % or less, 1.2 wt. % or less, 1.1 wt. % or less, 1.0 wt. % or less, 0.95 wt. % or less, 0.9 wt. % or less, 0.8 wt. % or less, 0 7.7 wt. % or less, 0.6 wt. % or less, 0.5 wt. % or less, 0.4 wt. % or less, 0.3 wt. % or less, 0.2 wt. % or less, or 0.1 wt. % or less), and a concentration of 1,3-butylene glycol of 95 area % or greater (or 96 area % or greater, 96.7 area % or greater, 97 area % or greater, 98 area % or greater, or 99 area % or greater) according to the gas chromatographic analysis performed under the conditions set forth above, and the distillation is performed under a condition that a reflux ratio is 0.03 or greater (or 0.05 or greater, 0.1 or greater, 0.2 or greater, 0.3 or greater, 0.4 or greater, 0.5 or greater, 0.6 or greater, 0.7 or greater, 0.8 or greater, 0.9 or greater, 1 or greater, 1.2 or greater, 1.5 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater, 10 or greater, or 20 or greater).
[32] The method for producing 1,3-butylene glycol according to any one of [26] to [31], wherein a bottom ratio in the high boiling point component removal column for use in the removing a high boiling point component is less than 30 wt. % (or 25 wt. % or less, 20 wt. % or less, 15 wt. % or less, 10 wt. % or less, 7 wt. % or less, 5 wt. % or less, 4 wt. % or less, 3 wt. % or less, 2 wt. % or less, or 1 wt. % or less).
[33] The method for producing 1,3-butylene glycol according to any one of [26] to [32], wherein the bottom ratio in the high boiling point component removal column for use in the removing a high boiling point component is 0.01 wt. % or greater (or 0.1 wt. % or greater, 0.5 wt. % or greater, 1 wt. % or greater, 2 wt. % or greater, 3 wt. % or greater, 4 wt. % or greater, 5 wt. % or greater, 6 wt. % or greater, 7 wt. % or greater, 8 wt. % or greater, 9 wt. % or greater, 10 wt. % or greater, 15 wt. % or greater, or 20 wt. % or greater).
[34] The method for producing 1,3-butylene glycol according to any one of [26] to [33], wherein a recovery ratio of 1,3-butylene glycol in the high boiling point component removal column for use in the removing a high boiling point component is greater than 80% (or 85% or greater, 90% or greater, 95% or greater, or 99% or greater).
[35] The method for producing 1,3-butylene glycol according to any one of [26] to [34], wherein at least a portion of a bottom of the high boiling point component removal column for use in the removing a high boiling point component is recycled to a step before the removing a high boiling point component.
[36] The method for producing 1,3-butylene glycol according to [35], wherein an amount of the bottom of the high boiling point component removal column, which is recycled to the step prior to the removing a high boiling point component, is less than 30 wt. % (or 25 wt. %, 20 wt. % or less, 15 wt. % or less, 10 wt. % or less, 7 wt. % or less, 5 wt % or less, 4 wt. % or less, 3 wt. % or less, 2 wt. % or less, or 1 wt. % or less) with respect to a charged amount into the high boiling point component removal column.
[37] The method for producing 1,3-butylene glycol according to 1351 or 1361, wherein the amount of the bottom of the high boiling point component removal column, which is recycled to the step prior to the removing a high boiling point component, is 0.01 wt % or greater (or 0.1 wt % or greater, 2 wt. % or greater, 3 wt % or greater, 4 wt. % or greater, 5 wt. % or greater, 7 wt. % or greater, 10 wt. % or greater, or 20 wt. % or greater) with respect to the charged amount into the high boiling point component removal column.
[38] A method for producing 1,3-butylene glycol to yield purified 1,3-butylene glycol from a reaction crude liquid containing 1,3-butylene glycol,
the method including:
performing dehydration including removing water by distillation and removing a high boiling point component including removing a high boiling point component by distillation,
wherein, in a high boiling point component removal column for use in the removing a high boiling point component, a charged liquid containing 1,3-butylene glycol is subjected to distillation, the charged liquid having a content of acetaldehyde of 500 ppm or less (or 205 ppm or less, 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, less than 2 ppm, or less than 1 ppm), a content of crotonaldehyde 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), a content of water of 3 wt. % or less (or 2 wt. % or less, 1.2 wt. % or less, 0.4 wt. % or less, 0.3 wt. % or less, 0.2 wt. % or less, 0.1 wt. % or less, 0.05 wt. % or less, or 0.03 wt. % or less), and a concentration of 1,3-butylene glycol of 96.7 area % or greater (or 97% or greater, 98% or greater, or 99% or greater) according to a gas chromatographic analysis performed under conditions set forth below, and the distillation is performed under a condition that a reflux ratio is 0.03 or greater (or 0.1 or greater, 0.2 or greater, 0.3 or greater, 0.4 or greater, 0.5 or greater, 0.6 or greater, 0.7 or greater, 0.8 or greater, 0.9 or greater, 1 or greater, 1.2 or greater, 1.5 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater, 10 or greater, or 20 or greater).
The conditions for the gas chromatographic analysis are as follows:
Analytical Column: a column with dimethylpolysiloxane as a stationary phase, having a length of 30 m, an inner diameter of 0.25 mm, and a film thickness of 1.0 μm
Heating conditions: heating from 80° C. to 120° C. at 5° C./min, then heating again to 160° C. at 2° C./min and maintaining for 2 minutes, and further heating to 230° C. at 10° C./min and maintaining at 230° C. for 18 minutes
Sample Introduction Temperature: 250° C.
Carrier Gas: helium
Column Gas Flow Rate: 1 mL/min
Detector and Detection Temperature: a flame ionization detector (FID), 280° C.
[39] The method for producing 1,3-butylene glycol according to any one of [26] to [38], wherein, in a dehydration column for use in the performing dehydration, a charged liquid containing 1,3-butylene glycol is subjected to distillation, the charged liquid having a content of acetaldehyde of 1000 ppm or less (or 900 ppm or less, 800 ppm or less, 700 ppm or less, 600 ppm or less, 500 ppm or less, 400 ppm or less, 300 ppm or less, 200 ppm or less, 155 ppm or less, 140 ppm or less, 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, or 1 ppm or less), a content of crotonaldehyde of 400 ppm or less (or 300 ppm or less, 200 ppm or less, 100 ppm or less, 150 ppm or less, 130 ppm or less, 117 ppm or less, 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, or 1 ppm or less), a content of water of 90 wt. % or less (or 85 wt. % or less, 80 wt. % or less, 70 wt. % or less, 60% wt. % or less, 50 wt. % or less, 40 wt. % or less, 35 wt. % or less, 30 wt. % or less, 25 wt. % or less, 15 wt. % or less, or 10 wt. % or less), and a concentration of 1,3-butylene glycol of 95 area % or greater (or 96 area % or greater, 96.7 area % or greater, 97 area % or greater, 98 area % or greater, or 99 area % or greater) according to the gas chromatographic analysis performed under the conditions set forth above, and the distillation is performed under a condition that a reflux ratio is greater than 0.3 (or 0.4 or greater, 0.5 or greater, 0.6 or greater, 0.7 or greater, 0.8 or greater, 0.9 or greater, 1 or greater, 1.1 or greater, 1.2 or greater, 1.3 or greater, 1.4 or greater, 1.5 or greater, 1.6 or greater, 1.7 or greater, 1.8 or greater, 1.9 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater, 6 or greater, 7 or greater, 8 or greater, 9 or greater, 10 or greater, 15 or greater, 20 or greater, 25 or greater, 30 or greater, or 40 or greater).
[40] The method for producing 1,3-butylene glycol according to any one of [26] to [39], wherein a distillation ratio in the dehydration column for use in the performing dehydration is 95 wt. % or less (or 90 wt. % or less, 85 wt. % or less, 80 wt. % or less, 75 wt. % or less, 70 wt. % or less, 65 wt. % or less, 60 wt. % or less, 55 wt. % or less, 50 wt. % or less, 45 wt. % or less, 40 wt. % or less, 35 wt. % or less, 30 wt. % or less, 25 wt. % or less, 20 wt. % or less, 15 wt. % or less, 10 wt. % or less, or 5 wt. % or less).
[41] The method for producing 1,3-butylene glycol according to any one of [26] to [40], wherein a recovery ratio of 1,3-butylene glycol in the dehydration column for use in the dehydration is 99.3% or greater.
[42] The method for producing 1,3-butylene glycol according to any one of [26] to [41], wherein the reaction crude liquid containing 1,3-butylene glycol is a reaction crude liquid produced by hydrogen reduction of an acetaldol.
[43] The method for producing 1,3-butylene glycol according to any one of [26] to [42], further including at least one step selected from alkali treatment including treating a process stream containing 1,3-butylene glycol with a base, desalting including removing a salt in a process stream containing 1,3-butylene glycol, and dealcoholization including removing a low boiling point substance containing an alcohol in a process stream containing 1,3-butylene glycol.

INDUSTRIAL APPLICABILITY

The 1,3-butylene glycol product according to the present disclosure has high purity and is colorless and odorless (or almost colorless and odorless), unlikely to cause coloration and odor over time, and/or unlikely to cause an acid concentration increase over time also in a state containing water. This 1,3-butylene glycol product can be used as a raw material for a moisturizer and a cosmetic product that have excellent moisturizing performance and can retain high quality for a long period of time.

REFERENCE SIGNS LIST

A: Dehydration column
B: Desalting column
C: Distillation column for removing a high boiling point component (high boiling point component removal column)
D: Alkaline reactor
E: Dealkalization column
F: Product distillation column (product column)
A-1, B-1. C-1, E-1, and F-1: Condenser
A-2, C-2, and F-2: Reboiler
X-1: Crude 1,3-butylene glycol
X-2: Water (discharged water)
X-3: A salt, a high boiling point component, and a portion of 1,3-butylene glycol
X-4: A high boiling point component and a portion of 1,3-butylene glycol
X-5: Sodium hydroxide, a high boiling point component, and a portion of 1,3-butylene glycol
X-6: A low boiling point component and a portion of 1,3-butylene glycol
Y: 1,3-butylene glycol product

Claims

1. A 1,3-butylene glycol product in which at least one of eight contents: a content of methyl vinyl ketone, a content of acetone, a content of butylaldehyde, a content of acetaldol, a content of a compound represented by Formula (1) below, a content of a compound represented by Formula (2) below, a content of a compound represented by Formula (3) below, and a total content of a compound represented by Formula (4) below and a compound represented by Formula (5) below, is less than 8 ppm

2. The 1,3-butylene glycol product according to claim 1, wherein a sum of the content of methyl vinyl ketone, the content of acetone, the content of butylaldehyde, the content of ace aldol, the content of the compound represented by Formula (1), the content of the compound represented by Formula (2), the content of the compound represented by Formula (3), the content of the compound represented by Formula (4), and the compound represented by Formula (5), is less than 71 ppm.

3. The 1,3-butylene glycol product according to claim 1, wherein at least the content of acetaldol is less than 8 ppm.

4. The 1,3-butylene glycol product according to claim 1, wherein at least the content of the compound represented by Formula (3) is less than 8 ppm.

5. The 1,3-butylene glycol product according to claim 1, wherein a total content of methyl vinyl ketone, acetone, and butylaldehyde is 24 ppm or less.

6. The 1,3-butylene glycol product according to claim 1, wherein a total content of the compound represented by Formula (1), the compound represented by Formula (2), the compound represented by Formula (4), and the compound represented by Formula (5) is 24 ppm or less.

7. The 1,3-butylene glycol product according to claim 1, which has a content of acetaldehyde of less than 4 ppm and a content of crotonaldehyde of less than 2 ppm.

8. The 1,3-butylene glycol product according too claim 1, wherein an acid concentration is less than 11 ppm in terms of acetic acid, and, after a 90 wt. % aqueous solution of the 1,3-butylene glycol product has been kept at 100° C. for 1 week, the aqueous solution has an acid concentration of less than 23 ppm in terms of acetic acid.

9. The 1,3-butylene glycol product according to claim 1, wherein an APHA is 6 or less, and, after the 1,3-butylene glycol product has been kept at 180° C. for 3 hours in air atmosphere, an APHA of 78 or less.

10. The 1,3-butylene glycol product according to claim 1, wherein an initial boiling point is higher than 203° C. and/or a dry point is 209° C. or lower.

11. The 1,3-butylene glycol product according to claim 1, wherein a potassium permanganate test value is 30 minutes or longer.

12. A moisturizer comprising the 1,3-butylene glycol product described in claim 1.

13. A cosmetic product comprising the moisturizer described in claim 12.

14. A method for producing 1,3-butylene glycol to yield purified 1,3-butylene glycol from a reaction crude liquid including 1,3-butylene glycol,

the method comprising: performing dehydration including removing water by distillation, removing a high boiling point component including removing a high boiling point component by distillation, and performing product distillation to yield purified 1,3-butylene glycol,

wherein, in a product column for use in the performing product distillation, a 1,3-butylene glycol charged liquid is subjected to distillation under a condition that a reflux ratio is 0.3 or greater, the 1,3-butylene glycol charged liquid having a content of acetaldehyde of 500 ppm or less, a content of crotonaldehyde of 200 ppm or less, a content of water of 0.7 wt. % or less, and a concentration of 1,3-butylene glycol of 97.6 area % or greater, according to a gas chromatographic analysis performed under conditions, and the conditions for the gas chromatographic analysis are as follows:

Analytical Column: a column with dimethylpolysiloxane as a stationary phase, having a length of 30 m, an inner diameter of 0.25 mm, and a film thickness of 1.0 μm

Heating conditions: heating from 80° C. to 120° C. at 5° C./min, then heating again to 160° C. at 2° C./min and maintaining for 2 minutes, and further heating to 230° C. at 10° C./min and maintaining at 230° C. for 18 minutes

Sample Introduction Temperature: 250° C.

Carrier Gas: helium

Column Gas Flow Rate: 1 mL/min

Detector and Detection Temperature: a flame ionization detector (FID), 280° C.

15. The method for producing 1,3-butylene glycol according to claim 14, wherein at least a portion of a distillate of the product column is recycled to a step before the performing the product distillation, the step including dehydration, dealcoholization, low boiling point component removal, or a step before the dehydration, the dealcoholization, the low boiling point component removal.

16. A method for producing 1,3-butylene glycol to yield purified 1,3-butylene glycol from a reaction crude liquid including 1,3-butylene glycol,

the method comprising: performing dehydration including removing water by distillation and removing a high boiling point component including removing a high boiling point component by distillation,

wherein, in a high boiling point component removal column for use in the removing a high boiling point component, a 1,3-butylene glycol-containing charged liquid is subjected to distillation under a condition that a reflux ratio is 0.03 or greater, the 1,3-butylene glycol-containing charged liquid having a content of acetaldehyde of 500 ppm or less, a content of crotonaldehyde of 200 ppm or less, a content of water of 3 wt. % or less, and a concentration of 1,3-butylene glycol of 96.7 area % or greater, according to a gas chromatographic analysis performed under conditions, and the conditions for the gas chromatographic analysis are as follows:

Sample Introduction Temperature: 250° C.

Carrier Gas: helium

Column Gas Flow Rate: 1 mL/min

Detector and Detection Temperature: a flame ionization detector (FID), 280° C.

17. The method for producing 1,3-butylene glycol according to claim 14, wherein the reaction crude liquid including 1,3-butylene glycol is a reaction crude liquid produced by hydrogen reduction of an acetaldol.

18. The method for producing 1,3-butylene glycol according to claim 14, further comprising at least one step selected from alkali treatment including treating a process stream including 1,3-butylene glycol with a base, desalting including removing a salt in a process stream including 1,3-butylene glycol, and dealcoholization including removing a low boiling point substance in a process stream including 1,3-butylene glycol, the low boiling point substance including an alcohol.

19. The method for producing 1,3-butylene glycol according to claim 16, wherein the reaction crude liquid including 1,3-butylene glycol is a reaction crude liquid produced by hydrogen reduction of an acetaldol.

20. The method for producing 1,3-butylene glycol according to claim 16, further comprising at least one step selected from alkali treatment including treating a process stream including 1,3-butylene glycol with a base, desalting including removing a salt in a process stream including 1,3-butylene glycol, and dealcoholization including removing a low boiling point substance in a process stream including 1,3-butylene glycol, the low boiling point substance including an alcohol.