JP2001233867A - Glycidol production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an industrial method for producing glycidol at a low cost by simplifying a producing step of allyl alcohol being a raw material for glycidol. SOLUTION: This method comprises directly epoxidizing a crude reaction solution with hydrogen peroxide without getting rid of high and low boilings wherein the crude solution is obtained by hydrolysis of allyl acetate and comprises 60-80 wt.% allyl alcohol, 0-5 wt.% allyl acetate and 20-40 wt.% water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing glycidol. Glycidol is a substance useful as a raw material for pharmaceuticals, paints, UV curing agents for semiconductors, and the like, such as glycidyl ether, glycidyl ester, (poly) glycerin ether, (poly) glycerin ester, and dihydroxypropylamine.

[0002]

2. Description of the Related Art As a method for producing glycidols, a method of oxidizing allyl alcohols with an organic peracid such as peracetic acid or a method of oxidizing with hydrogen peroxide (Japanese Patent Laid-Open No. 62-114)
980, JP-A-4-335032 and JP-A-6-95
No. 92), a method of oxidizing with a hydroperoxide, a method of oxidizing with oxygen, and the like have been proposed.

[0003] As a method for purifying glycidols, a catalyst is separated by distillation from a crude reaction solution obtained by reacting allyl alcohols with hydrogen peroxide, and the organic substances contained in the catalyst are burned off. A method of recycling to a reactor (Japanese Patent Publication No. 58-43142), a method of separating the catalyst by a thin-film evaporator in the above-mentioned decatalysis step (Japanese Patent Publication No. 60-55512), an allyl alcohol and hydrogen peroxide In the step of commercializing glycidol obtained by reacting glycidol with water at the top of the distillation column to separate without reflux (Japanese Patent Laid-Open No. 5-125069)
Etc. have been proposed.

[0004]

As described above, in the known production methods, many studies have been made to increase the type, selectivity or activity of the oxidizing agent in the reaction. Also,
Various studies have also been made on the purification method. However, no study has been made on the use of inexpensive and low-purity allyl alcohol as a raw material. That is, an object of the present invention is to provide an industrially inexpensive process for producing glycidol by simplifying the process for producing allyl alcohol, which is a raw material of the glycidol.

Conventionally, allyl alcohol as a starting material for synthesizing glycidol is disclosed in Japanese Patent No. 2662.
No. 965 and Japanese Patent Publication No. 8-1379, allyl acetate is synthesized by reacting propylene, oxygen and acetic acid in the gas phase, and the obtained allyl acetate is hydrolyzed with water. By separating the generated acetic acid, a crude reaction liquid of allyl alcohol can be obtained.
In this case, the substances contained in the allyl alcohol reaction crude liquid include allyl alcohol, allyl acetate, water and the like,
The composition is 60-80% by weight of allyl alcohol, 5% by weight or less of allyl acetate, and water and the like occupy other components. The raw material allyl alcohol for synthesizing glycidol has been obtained by subjecting the crude allyl alcohol reaction crude liquid to a treatment such as a treatment for removing low-boiling substances and a treatment for removing high-boiling substances.

[0006] The treatment for removing low-boiling substances referred to in the present invention is to remove water, low-boiling substances and the like from an allyl alcohol reaction crude liquid. Specifically, for example, using a distillation column having 20 to 40 plates, distillation is performed at a top pressure of 500 to 850 Torr and a bottom temperature of 85 to 120 ° C., and water / acetic acid is azeotropically distilled from the top of the column. Allyl and allyl alcohol are distilled off, and the fraction is condensed and liquefied to separate into an organic layer and an aqueous layer. The organic layer is rich in allyl acetate, and the whole or a part of the organic layer is returned to the distillation column as reflux. A trace amount of allyl acetate, allyl alcohol, etc. is present in the aqueous layer, and these substances are removed out of the system together with water.

[0007] The deboiler treatment is specifically, for example,
Using a distillation column having 20 to 50 plates, the top pressure is 500 to
By distillation at 850 Torr at a tower bottom temperature of 95 to 115 ° C., high-boiling substances such as allyl acetate which could not be removed by the treatment for removing low-boiling substances are discharged to the outside of the system.

[0008] As described above, the crude allyl alcohol reaction liquid is subjected to the treatment for removing low-boiling substances and the treatment for removing high-boiling substances, and the reason for this is that water, low-boiling substances removed by these treatments are removed. And high boilers have been thought to adversely affect glycidol production. Specifically, it has been considered that when excess water is present during the production of glycidol, glycidol is opened to form (poly) glycerin or the like, and the selectivity is reduced. In addition, when synthesizing glycidol by reacting allyl alcohol and hydrogen peroxide, a catalyst is used, and the presence of a low-boiling substance or a high-boiling substance poisons the catalyst for glycidol synthesis, and the catalyst is used as a catalyst. It was thought that the activity and the selectivity were reduced. It was further believed that low or high boilers could trigger the ring opening reaction of the formed glycidol. That is, in order to prevent a decrease in the selectivity of glycidol and a decrease in the catalytic activity, the treatment for removing low-boiling substances and the treatment for removing high-boiling substances have been carried out.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, have found that the reaction crude liquid containing mainly allyl alcohol obtained by hydrolyzing allyl acetate can be removed. The present invention has found that epoxidation with hydrogen peroxide can be performed without performing either low-boiling-point treatment or de-high-boiling-point treatment, without causing a decrease in glycidol selectivity and a decrease in catalytic activity. Was completed.

That is, a first aspect of the present invention is to provide a crude reaction solution obtained by hydrolyzing allyl acetate and containing 60 to 80% by weight of allyl alcohol, 0 to 5% by weight of allyl acetate and 20 to 40% by weight of water. Provided is a method for producing glycidol, which is characterized by epoxidation with hydrogen peroxide. In the second aspect of the present invention, the reaction crude liquid synthesizes allyl acetate by reacting propylene, oxygen and acetic acid in the gas phase, hydrolyzes the obtained allyl acetate with water, and separates acetic acid as a by-product. A method for producing glycidol according to the first aspect of the present invention is provided. A third aspect of the present invention is
Epoxidizing the reaction crude liquid obtained by hydrolyzing allyl acetate and containing mainly allyl alcohol with hydrogen peroxide without performing any treatment of removing low boilers or removing high boilers. And a method for producing glycidol.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The allyl alcohol reaction crude liquid used in the present invention synthesizes allyl acetate by reacting propylene, oxygen and acetic acid in a gas phase, hydrolyzes the obtained allyl acetate with water, and separates acetic acid as a by-product. Obtained by:

The above allyl alcohol reaction crude liquid is specifically produced as follows. Oxygen 4-8, acetic acid 1
1 to 15, propylene 15 to 25, water 1 to 4 by volume, and the other components are nitrogen or carbon dioxide.
Pressure 3 to 10 atm, temperature 140 to 2 using Pd catalyst
By performing the reaction at 00 ° C., allyl acetate can be obtained. When pressure is released, allyl acetate and the like, which are main components, are condensed by decomposing at 100 ° C. or less. Using a distillation column (actual stage 20 to 40 stages), top pressure 500 to 850
Torr, reflux ratio 0.5-10, tower bottom temperature 30-60 ° C
As a result, excess acetic acid, water, and the like are removed. Using a distillation column (actual stages 20 to 50), a top pressure of 20
0 to 760 Torr, reflux ratio 5 to 40, tower bottom temperature 50 to
By adjusting the temperature to 80 ° C., low-boiling substances such as acrolein and acetone as by-products are distilled off. Water is added to 100 parts of the crude liquid from which low-boiling substances such as acrolein and acetone are distilled off.
Add 50 parts, pressure 500-800 Torr, temperature 40
Allyl acetate is hydrolyzed at ~ 90 ° C using an ion exchange resin. Unreacted allyl acetate is distilled off by using a distillation column (actual stages 20 to 50) at a top pressure of 500 to 850 Torr, a reflux ratio of 0.5 to 10 and a bottom temperature of 40 to 80 ° C. Finally, using a distillation column (actual stages 20 to 50), the top pressure is 500 to 850 Torr, and the reflux ratio is 0.5 to 1
0, Allyl alcohol and water are distilled off azeotropically by adjusting the bottom temperature to 50 to 80 ° C. to remove acetic acid as a by-product. The thus obtained allyl alcohol reaction crude liquid generally contains 60 to 80% by weight of allyl alcohol, 0 to 5% by weight of allyl acetate, and the rest is water.

The obtained allyl alcohol reaction crude liquid is subjected to epoxidation with hydrogen peroxide without adding any of the above-mentioned treatments for removing low-boiling substances or removing high-boiling substances, and adding water and a catalyst. I do.

10 to 20 parts by weight of water and 0.01 to 20 parts by weight of the following catalyst are added to 100 parts by weight of allyl alcohol with respect to 100 parts by weight of the allyl alcohol reaction crude liquid, and the mixture is stirred to be uniform. The temperature is controlled to be 10 to 70 ° C. In this state, 1 to 10 hours are required, and 0.1 to 2 mol of hydrogen peroxide (concentration: 20 to 80% by weight) is added dropwise to 1 mol of allyl alcohol.
Aged for 1 to 10 hours. At this time, if the amount of hydrogen peroxide is less than 0.1 mol, the unreacted raw material becomes too large, which is disadvantageous in terms of recovery. If it exceeds 2 mol, the amount of unreacted hydrogen peroxide becomes too large, causing a danger at the time of concentration. Occurs. The reaction temperature is
If the temperature is lower than 10 ° C., the reaction rate becomes too slow, and if it exceeds 70 ° C., hydrogen peroxide becomes too unstable, which is not preferable.
Examples of the catalyst used in the present invention include a tungstate compound, a titanosilicate compound, and a molybdate compound. If these compounds are too strong to be used as they are, they are preferably partially neutralized with a base such as sodium hydroxide and used as a catalyst. When the amount of the catalyst is less than 0.01 part by weight, the reaction rate becomes too slow, and when the amount exceeds 20 parts by weight, side reactions increase.

The thus obtained glycidol reaction crude liquid is distilled to obtain purified glycidol. Distillation can be performed by continuous distillation or batch distillation. An example of the distillation method is as follows. Distillation tower (actual stage 10-30
Using (stage), the top pressure is 50 to 200 Torr, the reflux ratio is 0.1 to 5, the bottom temperature is 20 to 80 ° C., the reaction crude liquid is supplied, and the liquid containing glycidol, catalyst and the like is discharged. Then, using a forced thin-film evaporator, the top pressure is 1 to
At 50 Torr and at an evaporator temperature of 80 to 130 ° C., the bottoms are fed to distill crude glycidol, and the catalyst, high-boiling substances and some glycidol are withdrawn from the bottom of the bottom. Using a distillation column (actual stages 10 to 50), low-boiling substances such as water are completely distilled at a top pressure of 5 to 100 Torr by batch distillation. The main fraction is finally distilled in a distillation column (actual stages 10 to 45).
), And the column head pressure is 5 to 50 To by batch distillation.
rr, a distillation ratio of 0.1 to 10 and a bottom temperature of 50
Distill to ~ 150 ° C.

The glycidol obtained has a purity of 99.00.
Up to 99.99%, indicating high storage stability. According to the method of the present invention, glycidol can be selected with high selectivity and catalytic activity without subjecting a crude allyl alcohol reaction solution to a treatment for removing low boilers or a treatment for removing high boilers, as in a conventionally known method. Can be advantageously produced industrially without causing a decrease in

[0017]

The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

Reference Example 1 Using a 1 liter autoclave, oxygen / acetic acid / propylene / water = 6/13/1
The reaction was carried out at a temperature of 180 ° C. for 4 hours using a palladium catalyst supported on silica at a pressure of 5 atm and a volume ratio of 7/3 each. After the reaction is completed, the autoclave temperature is set to 8
Gas components were removed by releasing the pressure while maintaining the temperature at 0 ° C. The above-mentioned gas removal component was supplied at a rate of 1,300 g / h at an overhead pressure of 760 Torr, a reflux ratio of 1 and a tower bottom temperature of 110 ° C. using an 80φ Oldershaw distillation column (actual stage 30 stages) equipped with a vacuum jacket, Acetic acid and water were discharged at 930 g / h. Using an 80φ Oldershaw distillation column (actual stage 35 stages) with a vacuum jacket, the top pressure was 20
0 Torr, a reflux ratio of 20, and a bottom temperature of 70 ° C.
The distillate was supplied at a rate of g / h, and low-boiling substances such as acrolein and acetone were distilled off at a rate of 30 g / h. Using a strongly acidic ion exchange resin, 340 g of the obtained allyl acetate crude liquid and 30 g of water were applied at a pressure of 760 Torr and a temperature of 60 ° C.
Hydrolysis was performed for 5 hours to obtain a crude hydrolyzed liquid containing allyl alcohol. Using an 80-diameter Oldershaw distillation column equipped with a vacuum jacket (actual stage 30 stages), a top pressure of 760 Torr, a reflux ratio of 1, a bottom temperature of 103 ° C, and 9
The hydrolysis crude liquid was supplied at a rate of 00 g / h, and 930 g / h
h to remove acetic acid, allyl alcohol and water
Unreacted allyl acetate, water and the like were distilled off at a rate of 50 g / h. Finally, an 80 φ Oldershaw distillation column equipped with a vacuum jacket (actual stage 30 stages) was used to achieve a top pressure of 76
0 Torr, reflux ratio of 2, tower bottom temperature of 125 ° C., 450
g / h at a rate of 1000 g / h
Thus, a crude liquid containing allyl alcohol and water was obtained.

(Example 1) SUS316 with jacket
In a 20-liter reactor, 11,260 g of the crude allyl alcohol reaction liquid obtained in Reference Example 1 (allyl alcohol / water / allyl acetate = 71.7 / 27.2 / 1.0% by weight)
(139 mol of allyl alcohol) and 2,150 g of water,
A catalyst (82.2 g of tungstic acid and 375 g of a 4% aqueous sodium hydroxide solution) was added thereto, and the mixture was stirred so as to be uniform.
The temperature was controlled to be 40 ° C. In this state, the density 5
3,693 g of 8% by weight aqueous hydrogen peroxide (hydrogen peroxide content 1
09 mol) was added dropwise over 1 hour while controlling the reaction temperature at 40 ° C., and the mixture was aged for 4 hours. The reaction results were 48.7% conversion and 80.1% selectivity based on allyl alcohol.
Met.

Using an 80-diameter Oldershaw distillation column equipped with a vacuum jacket (30 actual stages), the top pressure was 100 To
rr, reflux ratio 1, tower bottom temperature 60 ° C, 1,600 g
The reaction crude liquid was supplied at a rate of 950 g / h, and a liquid containing glycidol, a catalyst and the like was discharged at a rate of 950 g / h. Then, using a forced thin film evaporator, the overhead pressure was 24 Torr.
r, heating at a heating temperature of 100 ° C., supplying the bottoms at a rate of 800 g / h, distilling crude glycidol at a rate of 704 g / h, and discharging the catalyst, high-boiling substances and some glycidol. . Finally, 4,000 g of the crude glycidol was charged into a 3 liter flask, and a 40φ Aldershaw distillation column (actual stage, 20 stages) equipped with a vacuum jacket was installed, and the liquid was heated in an oil bath. Water and low-boiling substances were all distilled at a tower pressure of 20 Torr. The main fraction was distilled at a top pressure of 6 Torr and a reflux ratio of 1 until the liquid temperature reached 110 ° C. The obtained glycidol has a purity of 99.
It was of high quality, 9% (stability 346 days).

(Comparative Example 1) In order to remove the low-boiling substance from the allyl alcohol reaction crude liquid obtained in Reference Example 1, a 40φ Oldershaw distillation column equipped with a vacuum jacket (actual stage 30)
), The crude liquid of the allyl alcohol reaction was charged at a rate of 400 g / h, and distilled at normal pressure, at a top temperature of 84 ° C and at a bottom temperature of 98 ° C, and the distillate at the top was condensed and liquefied to form an organic layer. Was returned to the column as a reflux, and the liquid containing allyl alcohol was
g / h. Next, in order to remove the high-boiling point product from the bottoms, it was charged at a rate of 204 g / h into a 40φ Oldershaw distillation column equipped with a vacuum jacket (actual stage 30 stages) at a normal pressure, a top temperature of 94 ° C., and a bottom temperature. Distillation was performed at 105 ° C. and a reflux ratio of 0.5, and a liquid containing allyl alcohol was distilled off at a rate of 200 g / h from the top of the tower. The purity of the allyl alcohol purified by the above operation was 99.5%.

To a jacketed SUS316 20 liter reactor were added 8,400 g of the above allyl alcohol (144 mol of allyl alcohol), 2,150 g of water, and a catalyst (82.2 g of tungstic acid and 375 g of a 4% aqueous sodium hydroxide solution). Stirring was performed so as to be uniform, and the temperature was controlled to be 40 ° C. In this state, the density 5
3,693 g of 8% by weight aqueous hydrogen peroxide (hydrogen peroxide content 1
(0.9 mol) was added dropwise over 1 hour while controlling the reaction temperature at 40 ° C., followed by aging for 4 hours. The reaction results were 46.9% in conversion and 65.2% in selectivity based on allyl alcohol. The obtained crude reaction solution of glycidol was treated in the same manner as in Example 1 to obtain a product having a purity of 99.7% (stability: 209 days).

Table 1 shows the composition of the starting allyl alcohol used in Example 1 and Comparative Example 1, Table 2 shows the reaction results, and Table 3 shows the quality of the obtained product.

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

[Table 3]

[0027]

Industrial Applicability The allylic alcohol-reacted crude liquid can be industrially produced without a low glycidol selectivity and without lowering the catalytic activity, without performing any of the treatments for removing low-boiling substances and removing high-boiling substances. It can be advantageously manufactured.

Claims (3)

[Claims] An epoxidation of a crude reaction solution obtained by hydrolyzing allyl acetate and containing 60 to 80% by weight of allyl alcohol, 0 to 5% by weight of allyl acetate and 20 to 40% by weight of water with hydrogen peroxide. A process for producing glycidol. 2. The reaction crude liquid synthesizes allyl acetate by reacting propylene, oxygen and acetic acid in a gas phase,
2. The method for producing glycidol according to claim 1, wherein the obtained allyl acetate is hydrolyzed with water to separate acetic acid as a by-product. 3. A reaction crude liquid obtained by hydrolyzing allyl acetate and mainly containing allyl alcohol is treated with hydrogen peroxide without performing any of a treatment for removing low-boiling substances and a treatment for removing high-boiling substances. A process for producing glycidol, which comprises epoxidizing with glycidol.