JP2018154540A - Manufacturing method of hydrogen peroxide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means capable of manufacturing hydrogen peroxide as a form of hydrogen peroxide water at relatively high concentration at low cost, simply and at high efficiency.SOLUTION: There is provided a manufacturing method of a hydrogen peroxide-containing solution, including (a) a step for preparing an organic solvent solution of amylanthrahydroquinone in a container 1, in which the organic solvent is immiscible with water; (b) a step for oxidizing the amylanthrahydroquinone in the solution 1 to amylanthraquinone by continuously injecting an oxygen gas with a fine bubble 2 form to the solution under ordinary pressure and maintaining a state that the fine bubbles of the oxygen gas are dispersed in the solution 1; (c) a step for stopping injection of the oxygen gas, adding water into the container and mixing the same with the solution; (d) a step for standing a mixture in the container and separating the same into 2 layers, which are an organic solvent phase and a water phase; and (e) a step for recovering the water phase from the container.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a method for synthesizing hydrogen peroxide. By utilizing a fine bubble technique using amylanthraquinone, the present invention relates to a hydrogen peroxide suitable for producing a necessary amount (on-site production) of hydrogen peroxide when necessary. The present invention relates to a simple and efficient production method.

Hydrogen peroxide (H ₂ O ₂ ) has a higher redox potential than oxygen, can oxidize a wide range of substrates, and is industrially used primarily in bleaching, wastewater treatment, disinfection, and cleaning applications. Yes. Since the co-product of hydrogen peroxide when used in the oxidation reaction is only water, it is harmless, does not place a burden on the environment, and has an advantage that the effective oxygen ratio is high as a reaction reagent.

  The industrial production of hydrogen peroxide is mainly based on the anthraquinone method. This method utilizes the property that anthrahydroquinone is auto-oxidized to anthraquinone by oxygen gas, and utilizes the generation of hydrogen peroxide by the reduction of oxygen that occurs as a counter reaction. Specifically, in the anthraquinone method, oxygen is reduced when anthrahydroquinone is auto-oxidized to anthraquinone in an organic solvent solution at a temperature of 30 to 60 ° C., for example, by contacting with an atmospheric pressure (1 atm) oxygen gas. The resulting hydrogen peroxide is extracted with water and then distilled under reduced pressure to produce hydrogen peroxide in the form of a high concentration (approximately 30 w / v% aqueous solution) of hydrogen peroxide. Anthraquinone remaining in the organic solvent after extraction with water is regenerated to anthrahydroquinone by catalytic hydrogenation under pressure and heating (for example, 4 atm, 40-50 ° C.) and reused for the production of hydrogen peroxide. Is done. As described above, the production of hydrogen peroxide as an industrial product requires a pressure vessel, includes a heating / pressurizing step and an extraction / vacuum distillation step, and includes a generated by-product removing step. It consists of a multi-step process.

  As an improvement of the anthraquinone method, a method of separating a catalyst-free working solution from a working solution of a hydrogenation circulation system of an anthraquinone method for producing hydrogen peroxide containing noble metal-black as a catalyst is known (Patent Literature). 1). This method uses a specific ceramic filter cartridge and allows catalyst removal without filter clogging.

  As an improvement to the anthraquinone method, an organic working solution, an oxygen-containing gas and an aqueous extraction solvent are fed into one and the same reactor to form a three-phase mixture, so that oxidation and extraction are performed in the same region, and then the reactor The hydrogen peroxide aqueous solution is recovered by phase-separating the reaction solution from the reactor, and the concentration of the aqueous hydrogen peroxide solution produced can be controlled by connecting multiple reactors in series to perform an oxidation reaction. This is known (Patent Document 2).

  Currently, for industrial use, hydrogen peroxide is produced and sold as a 30 w / v% aqueous solution (hydrogen peroxide solution). Hydrogen peroxide is degradable and has strong oxidizing power, and is designated as a hazardous material class 6 (oxidizing liquid) by the Fire Service Act. For this reason, installation, management, and operation of the manufacturing facility are costly. Although hydrogen peroxide is an excellent environmentally friendly oxidizer, a wider variety of applications are being considered, but the high cost associated with ensuring safety extends the industrial use of hydrogen peroxide in many ways. The use as an industrial oxidant has so far been limited to limited applications.

  Therefore, there is a potential demand for the ability to use hydrogen peroxide industrially at a lower cost.

  On the other hand, a literature based on computational chemistry that discloses that hydrogen peroxide is generated by the anthraquinone method and used directly in the oxidation reaction is known (Non-Patent Document 1). In this document, hydrogen peroxide generated by the anthraquinone method is extracted, methanol is added, the mixture is mixed with a cyclohexane solution of ammonia, the ammoxidation is performed, the product is taken out, and the ammonia and cyclohexane oxime are extracted. It is described that cyclohexane oxime can be produced by separating the solution into the above. However, it is a simulation by calculation and there is no experimental data.

  Moreover, the organic layer containing 2-ethylanthrahydroquinone produced by catalytic hydrogenation of 2-ethylanthraquinone is used as it is for the next reaction (regeneration of 2-ethylanthraquinone by auto-oxidation and production of hydrogen peroxide). Is known (Non-Patent Document 2).

  While flowing a solution containing 2-ethylanthraquinone into the microreactor, a gas containing hydrogen was introduced into the solution in the form of fine bubbles through the filtration membrane in the microreactor, and the solution in which the fine bubbles were dispersed was obtained. There is known a method of introducing into an immobilized catalyst column and reducing to 2-ethylanthrahydroquinone (Non-patent Document 3).

  A method for producing a hydrogen peroxide-containing aqueous solution, comprising preparing an organic solvent solution of an alkylanthrahydroquinone in which an alkyl group is an alkyl group having 1 to 4 carbon atoms in a container, wherein the organic solvent is water A step of being immiscible with the solution, and continuously injecting oxygen gas in the form of fine bubbles under normal pressure into the solution to maintain a state in which the fine bubbles of oxygen gas are dispersed in the solution. Oxidizing the alkyl anthrahydroquinone in which the alkyl group in the solution is an alkyl group having 1 to 4 carbon atoms into an alkyl anthraquinone in which the alkyl group is an alkyl group having 1 to 4 carbon atoms; Stopping the gas injection, adding water into the vessel and mixing with the solution, and allowing the mixture in the vessel to stand to separate the organic solvent phase and the aqueous phase into two layers. If, comprising the step of recovering the aqueous phase from the container, it is known concentrations of hydrogen peroxide-containing aqueous solution is from production method 3 percent less (Patent Document 3).

If it is manufactured in an industrial facility that uses hydrogen peroxide, there is no transportation cost. Therefore, in order to expand the industrial use of hydrogen peroxide, by using fine bubble technology using amylanthraquinone, high concentration hydrogen peroxide water that does not require special facilities can be used in the facilities themselves. It is desirable to be able to manufacture at a low cost and at a high rate in the required amount when needed.

Japanese Patent Laid-Open No. 7-330311 JP-A-8-322003 Japanese Patent Laying-Open No. 2015-20940

T. Liu et al., Ind. Eng. Chem. Res., Vol. 43, p.166-172 (2004) N. Zhou et al., Applied Catalysis A: General 250, p.239-245 (2003) J. Tan et al., AIChE Journal, Vol.58, No.5, p.1326-1335 (2012)

  In the above background, the object of the present invention is to produce hydrogen peroxide (on-site production) by utilizing the fine bubble technology using amylanthraquinone, and in the form of a relatively high concentration hydrogen peroxide water, It is to provide a means capable of such manufacture at a low cost, in a simple and high rate.

  In the reaction of oxidizing and reducing the organic working solution in the anthraquinone method, the present inventor operates the oxygen gas and hydrogen gas used in the reaction in the form of fine bubbles (fine bubbles) having a particle diameter smaller than 1 μm. By supplying it into the solution, oxidation and reduction of the anthraquinone method can be carried out very efficiently and safely at normal temperature and normal pressure, and extraction with hydrogen peroxide from the organic working solution after oxidation is very high. It was found that hydrogen peroxide water was obtained in a yield. The present invention shown below has been completed based on these findings.

1. A method for producing a hydrogen peroxide-containing aqueous solution,
(A) preparing an organic solvent solution of amylanthrahydroquinone in a container, wherein the organic solvent is immiscible with water;
(B) Continuously injecting oxygen gas into the solution in the form of fine bubbles under normal pressure to maintain a state in which the fine bubbles of oxygen gas are dispersed in the solution, whereby the amyl anthra in the solution Oxidizing hydroquinone to amylanthraquinone;
(C) stopping the injection of oxygen gas, adding water into the vessel and mixing with the solution;
(D) allowing the mixture in the container to stand to separate the organic solvent phase and the aqueous phase into two layers;
(E) recovering the aqueous phase from the container.
2. The organic solvent solution of amyl anthrahydroquinone in step (a) is continuously injected into the corresponding organic solvent solution of amyl anthraquinone in the vessel under fine pressure in the form of fine bubbles. While maintaining the state in which fine bubbles of hydrogen gas are dispersed in the phase, the organic solvent phase is circulated between the container through the catalytic reduction catalyst disposed outside the container, The production method according to 1 above, which is prepared by reducing the amylanthraquinone in the organic solvent phase to amylanthrahydroquinone.
3. The hydrogen gas fine bubbles are dispersed in the organic solvent phase by continuously injecting hydrogen gas into the organic solvent phase remaining in the vessel after performing step (e) under normal pressure in the form of fine bubbles. The organic solvent phase is circulated between the container through the catalytic reduction catalyst disposed outside the container while maintaining the maintained state, and the amylanthraquinone in the organic solvent phase in the container is circulated. The production of 1 or 2 above, further comprising the step (f) of regenerating the organic solvent solution of amylanthrahydroquinone into the container by reducing amylanthrahydroquinone to amylanthrahydroquinone Method.
4). The production method according to 3 above, wherein steps (b) to (f) are repeated one or more times.
5. 5. The production method according to any one of 1 to 4 above, wherein the number of bubbles having a particle diameter of 5 nm or more and less than 1000 nm is 90% or more of the total number of bubbles.
6). The production method according to any one of claims 1 to 5, wherein the amyl group is bonded to the 2-position carbon of anthrahydroquinone.
7). The amylanthrahydroquinone is 2- (1,1-dimethylpropyl) anthrahydroquinone, 2- (1,2-dimethylpropyl) anthrahydroquinone, or 2- (1,1-dimethylpropyl) anthrahydroquinone and 2- (1 , 2-Dimethylpropyl) anthrahydroquinone.
8). The method according to any one of claims 1 to 7, wherein the organic solvent is a mixed solvent of an alcohol having 8 to 10 carbon atoms and an aromatic hydrocarbon having a substituent.
9. The production method according to any one of claims 1 to 8, wherein the aromatic hydrocarbon having a substituent is toluene, xylene, or trimethylbenzene.

According to the present invention, without using a pressure vessel, using only simple equipment in a facility that intends to use hydrogen peroxide, by utilizing fine bubble technology using amylanthraquinone at room temperature and normal pressure, In the form of a relatively high concentration hydrogen peroxide solution, it becomes possible to efficiently produce the required amount as needed. On-site manufacturing does not incur costs due to transportation. Further, according to the present invention, since the utilization rate of the gas used is very high, the gas consumption can be minimized.
Therefore, according to the present invention, the use of hydrogen peroxide can be extended to industrial fields where other oxidizing agents have been used for reasons of high cost, and the burden on the environment can be reduced. In addition, according to the present invention, in an industrial facility that uses hydrogen peroxide, it is possible to immediately use it after on-site production when necessary, so it becomes unnecessary to store hydrogen peroxide water, Since it is not necessary to add a stabilizer (nitric acid, phosphoric acid, etc.) to hydrogen peroxide, it becomes possible to prevent these impurities from being mixed into products manufactured using hydrogen peroxide water.

FIG. 1 is a schematic diagram of an example of an apparatus used in the present invention. FIG. 2 is a schematic diagram showing a flow of fluid in the step of reducing amylanthraquinone in the working solution in the above apparatus. FIG. 3 is a schematic diagram showing a fluid flow in the step of oxidizing amylanthrahydroquinone in the working solution in the above-described apparatus. FIG. 4 is a schematic diagram showing a fluid flow in the step of extracting hydrogen peroxide from the working solution in the above-described apparatus.

  In this specification, “fine bubbles” are fine bubbles of gas in a liquid, and the number of bubbles having a particle diameter of 5 nm or more and less than 1000 nm is 90% or more with respect to the total number of bubbles. The number of bubbles having a particle diameter of 50 to 500 nm is preferably 90% or more, more preferably the number of bubbles having a particle diameter of 50 to 400 nm is 90% or more. Say things.

  In the present invention, the oxidation reaction and reduction reaction of the working solution may be performed under heating (for example, about 40 ° C.), but it is not necessary, and it is sufficiently performed only at room temperature (for example, 10 to 25 ° C.). be able to.

  As the organic solvent used for preparing the working solution, amylanthraquinone and amylanthrahydroquinone can be dissolved, and the generated hydrogen peroxide is dissolved without disturbing the smooth oxidation / reduction reaction between them and fine bubbles. An organic solvent that is immiscible with water is used. Any organic solvent having such properties can be appropriately selected and used. Examples of preferable organic solvents include a mixed solvent of an aliphatic alcohol or phosphate ester having 8 to 10 carbon atoms and an aromatic hydrocarbon having the substituent, for example, an aliphatic alcohol having 8 to 10 carbon atoms. 1-octanol, 2-octanol, 2-ethylhexanol, 1-nonanol, 2-nonanol, isononanol, 1-decanol, 2-decanol, etc., phosphate ester, tris-ethylhexyl phosphate, trioctyl phosphate, etc. The aromatic hydrocarbon having the substituent is toluene, xylene, butylbenzene, trimethylbenzene or the like.

  The concentration of amylanthraquinone or amylanthrahydroquinone in the working solution is not particularly limited as long as it is a concentration capable of maintaining the state in which these both compounds are completely dissolved, and can be appropriately set within the range. For example, in the case of a working solution obtained by dissolving 2- (1,1-dimethylpropyl) anthraquinone (2- (1,1-dimethylpropyl) anthrahydroquinone) in a mixed solvent of isononanol and trimethylbenzene, a suitable solute concentration is used. One example is 0.75 mol / L (208.8 g / L), but is not limited thereto.

  For reduction of 2-amylanthraquinone to 2-amylanthrahydroquinone, a well-known catalytic hydrogenation catalyst may be appropriately selected and used in the anthraquinone method. An example of a preferred catalyst is a Pd catalyst. In the present invention, a 0.5 wt% Pd catalyst supported on alumina particles can be used, but is not limited thereto.

  What is necessary is just to set suitably the length of time of the oxidation reaction of a working solvent, and the reductive reaction according to the amount of 2-amylanthraquinone in a working solution, and the addition amount per time of the fine bubble with respect to a working solution. This can be done by, for example, sampling a small amount of the working solution and quantifying the hydrogen peroxide concentration during the oxidation reaction of the working solution, and by sampling a small amount of the working solution, for example, during the reduction reaction of the working solution. This can be done by measuring the 2-amylanthrahydroquinone concentration. The reduction reaction may be 2 to 4 hours, the oxidation reaction may be 1.5 to 4 hours, but is not limited thereto.

The rate of addition of gas (hydrogen or oxygen) in the form of fine bubbles to the working solution may be appropriate, but it is usually preferable to set it near 1/30 (volume / volume) of the working solution per minute. . This is because the added gas can be used for the reaction without any waste, and the reaction efficiency is further increased.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail with reference to an Example, this invention is not intended to be limited to an Example.

[Configuration of hydrogen peroxide production equipment]
FIG. 1 shows a schematic diagram of an example of an apparatus for carrying out the present invention. In the figure, 1 is a working solution container (100 mL durambin), 2 is a fine bubble generator, 3 is a flow control device, 4 is a catalytic hydrogenation catalyst fixing tube containing an alumina spherically supported Pd catalyst inside, 5 Is a three-way cook. The fine bubble generator 2 and the three-way cock 5 are connected by a pipe 6. From the three-way cock 5, a pipe 7 directly extends into the working solution container 1, and a pipe 9 is fixed between the contact hydrogenation catalyst. It extends through the tube 4 into the working solution container 1. A pipe 8 extends from the working solution container 1 to the fine bubble generator 2. The flow rate control device 3 is supplied with oxygen gas or hydrogen gas in accordance with the oxidation reaction and the reduction reaction to be performed. The flow control device 3 is configured to supply gas to the fine bubble generating device 2 at a predetermined flow rate adjusted by the user. The fine bubble generating device 2 sucks the liquid in the working solution container 1 through the pipe 8, adds hydrogen gas or oxygen gas in the form of fine bubbles, and then discharges the liquid toward the three-way cock 5. It is configured.

  When hydrogen gas is added to the liquid, that is, when the reduction reaction of the working solution is performed, the three-way cock is opened with respect to the pipe 9 (catalytic hydrogenation catalyst side) and closed with respect to the pipe 7. It is operated by hand (FIG. 2). When oxygen gas is added to the liquid, that is, when an oxidation reaction of the working solution is performed, the three-way cock 5 is operated so as to be opened with respect to the pipe 7 and closed with respect to the pipe 9 (catalyst side). (FIG. 3). The device can also be used as an extraction device when hydrogen peroxide is extracted from the working solution with water after the oxidation reaction, in which case the working solution container functions as an extraction vessel, to which extraction water is added. With the three-way cock open to the pipe 7, the gas supply to the fine bubble generator is shut off and the fine bubble generator is operated as a circulation / stirring device (FIG. 4). Stir and mix vigorously with water.

  As the fine bubble generating device 2, a fine bubble generating device MA3FS [Asp Corporation] was used. The fine bubble generator has a function of creating fine bubbles in a liquid by injecting a gas into the liquid and applying a shearing force to the flow of the gas / liquid mixture with a static mixer to repeatedly divide the liquid.

  A working solution is accommodated in the working solution container 1. The working solution is an organic solvent solution containing 2-amylanthraquinone or 2-amylanthrahydroquinone, depending on the stage of the hydrogen peroxide production cycle, and in this example, 2- (1,1-dimethylpropyl) anthraquinone. Alternatively, an organic solvent solution containing 2- (1,1-dimethylpropyl) anthrahydroquinone, which is a reduced form thereof, 2- (1,2-dimethylpropyl) anthraquinone, or 2- (1,2-dimethyl, which is a reduced form thereof. 2- (1,1-dimethyl) which is an organic solvent solution containing propyl) anthrahydroquinone, a mixture of 2- (1,1-dimethylpropyl) anthraquinone and 2- (1,2-dimethylpropyl) anthraquinone, or a reduced product thereof Propyl) anthrahydroquinone and 2- (1,2-dimethylpropyl) anthrahydroquino The organic solvent solution containing a mixture of a. As the organic solvent, a mixed solvent of isononanol and trimethylbenzene was used in this example.

[Measurement of bubble particle size]
The particle size of the foam formed by the fine bubble generator was measured by a nanoparticle measuring device (NanoSight, Nippon Quantum Design Co., Ltd.). The measurement conditions were as follows.
・ Solvent: Mixed solvent of isononanol and trimethylbenzene ・ Gas: Air ・ Fine bubble discharge pressure: 0 to 1.0 MPa
-Liquid flow rate: 112 mL / min-Gas flow rate: 3 mL / min As a result of the measurement, the presence of bubbles was confirmed from the particle size of the minimum size of 3 nm that could be measured. The total number of bubbles formed (100%) has a particle size of 5 to 500 nm, and the bubbles having a particle size of 50 to 400 nm are well over 95% of the total number of bubbles.

[Quantification of hydrogen peroxide]
The amount of hydrogen peroxide in the produced hydrogen peroxide-containing water was determined by a conventional method using a 0.02M potassium permanganate aqueous solution.

[Example 1]
In a working solution container, a stir bar, a mixed solvent of isononanol and trimethylbenzene (100 mL) and 2- (1,1-dimethylpropyl) anthraquinone (0.75 mol / L) are added and stirred, and isononanol and trimethylbenzene are stirred. A working solution was prepared by dissolving 2- (1,1-dimethylpropyl) anthraquinone in the mixed solvent. A spherical catalyst-supported Pd catalyst (2 wt% Pd / Al ₂ O ₃ , 2 to 4 mm, 3.4 mol% with respect to the amount of 2- (1,1-dimethylpropyl) anthraquinone) as a catalyst fixing tube (filter size: 7 μm) After the fine bubble generator is washed with a mixed solvent of isononanol and trimethylbenzene, the three-way cock is opened with respect to the pipe 9 (and therefore on the side passing through the catalytic hydrogenation catalyst), and the hydrogen gas cylinder is connected to the flow control device. In the connected state, the fine bubble discharge pressure at the discharge needle needle valve of the fine bubble generator is set to 0 to 0.6 MPa, the liquid flow rate is about 130 mL / min, and the hydrogen gas flow rate is set to 5 mL / min. The apparatus was started at 40 ° C. and operated for 4 hours. In this way, by circulating the working solution between the working solution container, the fine bubble generator, and the catalytic hydrogenation catalyst fixing tube, 2- (1,1-dimethylpropyl) anthraquinone 2- (1,1- A reduction reaction (catalytic hydrogenation) to (dimethylpropyl) anthrahydroquinone was carried out.

  The apparatus was stopped, the three-way cock was switched, the working solution remaining on the catalyst fixing pipe side was returned to the working solution container, and the apparatus was started at 40 ° C. with the oxygen gas cylinder connected to the flow control device. Fine bubble generator needle valve discharge pressure is 0-0.6MPa, liquid flow rate is set at about 130mL / min, oxygen gas flow rate is set at 5mL / min. Of 2- (1,1-dimethylpropyl) anthrahydroquinone to 2- (1,1-dimethylpropyl) anthraquinone and paired with this by circulating between the container and the fine bubble generator A reduction reaction of oxygen to hydrogen peroxide was performed. The apparatus was stopped and 5 mL of distilled water was added to the working solution container. The apparatus is started with the gas flow in the fine bubble generator shut off, and the hydrogen peroxide is removed by mixing and stirring the working solution and water between the working solution container and the fine bubble generator. Extracted into phase. When the apparatus was stopped and the liquid in the working solution container was allowed to stand, the oil phase and the water phase separated with a clear interface, and the water phase could be easily separated and removed from the oil phase. 5 mL of distilled water was again added to the working solution container, and hydrogen peroxide remaining in the oil phase was extracted into a water tank in the same manner as described above. The extraction operation was repeated once again to extract hydrogen peroxide remaining in the oil phase into a water tank. These three extracts were combined (15 mL), and as a result of the analysis, the hydrogen peroxide concentration in the aqueous phase was 10.6% by weight, and the excess relative to the molar amount of 2- (1,1-dimethylpropyl) anthraquinone used. The yield of hydrogen oxide was found to be 62%.

[Example 2]
A hydrogen peroxide solution was produced in the same manner as in Example 1 except that 2- (1,1-dimethylpropyl) anthraquinone was changed to 2- (1,2-dimethylpropyl) anthraquinone. As a result of the analysis, the hydrogen peroxide concentration was 10.6% by weight, and the yield of hydrogen peroxide relative to the molar amount of 2- (1,2-dimethylpropyl) anthraquinone used was 62%.

Example 3
In the same manner as in Example 1 except that 2- (1,1-dimethylpropyl) anthraquinone was changed to a mixture of 2- (1,1-dimethylpropyl) anthraquinone and 2- (1,2-dimethylpropyl) anthraquinone. Hydrogen oxide water was produced. As a result of the analysis, the hydrogen peroxide concentration was 10.6% by weight, and the yield of hydrogen peroxide was 62% with respect to the molar amount of the mixture of 1,1-dimethylpropylanthraquinone and 1,2-dimethylpropylanthraquinone used. .

[Comparative Example 1]
Implemented except that the anthraquinone used was 2-ethylanthraquinone, the solvent constituting the working solution was ethyl acetate, the amount of the alumina spherical supported Pd catalyst was 2.5 mol% with respect to the amount of 2-ethylanthraquinone, and the number of extractions was twice. In the same manner as in Example 1, hydrogen peroxide water was produced. As a result of the analysis, the hydrogen peroxide concentration was 2.5% by weight, and the yield of hydrogen peroxide relative to the molar amount of 2-ethylanthraquinone used was 59%.

[Comparative Example 2]
A hydrogen peroxide solution was produced in the same manner as in Comparative Example 1 except that the time of the reduction reaction of the working solution was 4 hours. As a result of analysis, the hydrogen peroxide concentration was 2.6% by weight, and the yield of hydrogen peroxide relative to the molar amount of 2-ethylanthraquinone used was 63%.

[Comparative Example 3]
A hydrogen peroxide solution was produced in the same manner as in Comparative Example 1 except that the reduction time of the working solution was 3 hours and the oxidation reaction time was 1.5 hours. As a result of analysis, the hydrogen peroxide concentration was 3.0% by weight, and the yield of hydrogen peroxide relative to the molar amount of 2-ethylanthraquinone used was 70%.

[Comparative Example 4]
A hydrogen peroxide solution was produced in the same manner as in Comparative Example 1 except that the reduction time of the working solution was 4 hours. As a result of analysis, the hydrogen peroxide concentration was 3.2% by weight, and the yield relative to the molar amount of 2-ethylanthraquinone used was 75%.

[Comparative Example 5]
Comparative Example 1 except that the amount of the alumina spherical supported Pd catalyst was 2.6 mol% with respect to the amount of 2-ethylanthraquinone, the reduction time of the working solution was 3 hours, and the oxidation reaction time was 1.5 hours. Thus, hydrogen peroxide water was produced. As a result of analysis, the hydrogen peroxide concentration was 3.1% by weight, and the yield of hydrogen peroxide relative to the molar amount of 2-ethylanthraquinone used was 72%.

[Comparative Example 6]
A working solution similar to that of Comparative Example 1 was prepared in a working solution container without using a fine bubble generator, and the same amount of the spherical alumina-supported Pd catalyst used in Comparative Example 1 was operated in the working solution container. Directly charged into the solution, hydrogen gas containing hydrogen gas connected to the working solution container is supplied to fill the space above the working solution with hydrogen gas at almost normal pressure, and this is filled for 2 hours at 30 ° C. or 4 hours. Then, the working solution container is opened, the catalyst is removed, the oxygen solution is supplied to the space above the working solution by a balloon containing oxygen gas, and then filled. In this state, an oxidation reaction was performed at 30 ° C. for 2 hours. Distilled water was added to the working solution container to extract and analyze water-soluble components, but no hydrogen peroxide was produced.

[Comparative Example 7]
A working solution similar to that of Example 1 was prepared in a working solution container without using a fine bubble generator, and the same amount of the spherical alumina-supported Pd catalyst used in Comparative Example 1 was operated in the working solution container. Hydrogen gas is continuously bubbled from the center to the bottom of the working solution (5 mL / min) through a commercially available ceramic filter attached to the tube tip connected to a balloon containing hydrogen gas connected to the working solution container. In this state, the reduction reaction is performed at 30 ° C. for 2 hours or 4 hours, and then the lid of the working solution container is opened, the catalyst is removed, and then passed through a ceramic filter at the tip of the tube connected to a balloon containing oxygen gas. In a state where oxygen gas was continuously bubbled (5 mL / min) from the center to the bottom of the working solution, an oxidation reaction was performed at 30 ° C. for 2 hours. Distilled water was added to the working solution container to extract and analyze water-soluble components, but no hydrogen peroxide was produced.

  The present invention is useful in that it enables low-cost hydrogen peroxide on-site synthesis, and thereby facilitates the development of new industrial applications for hydrogen peroxide.

DESCRIPTION OF SYMBOLS 1 Working solution container 2 Fine bubble generator 3 Flow control device 4 Catalytic hydrogenation catalyst fixed pipe 5 Three-way cock 6-9 Pipe

Claims (9)

A method for producing a hydrogen peroxide-containing aqueous solution,
(A) preparing an organic solvent solution of amylanthrahydroquinone in a container, wherein the organic solvent is immiscible with water;
(B) Continuously injecting oxygen gas into the solution in the form of fine bubbles under normal pressure to maintain a state in which the fine bubbles of oxygen gas are dispersed in the solution, whereby the amyl anthra in the solution Oxidizing hydroquinone to amylanthraquinone;
(C) stopping the injection of oxygen gas, adding water into the vessel and mixing with the solution;
(D) allowing the mixture in the container to stand to separate the organic solvent phase and the aqueous phase into two layers;
(E) recovering the aqueous phase from the vessel.
Production method.   The organic solvent solution of amyl anthrahydroquinone in step (a) is continuously injected into the corresponding organic solvent solution of amyl anthraquinone in the vessel under fine pressure in the form of fine bubbles. While maintaining the state in which fine bubbles of hydrogen gas are dispersed in the phase, the organic solvent phase is circulated between the container through the catalytic reduction catalyst disposed outside the container, The process according to claim 1, which is prepared by reducing the amylanthraquinone in the organic solvent phase to amylanthrahydroquinone.   The hydrogen gas fine bubbles are dispersed in the organic solvent phase by continuously injecting hydrogen gas into the organic solvent phase remaining in the vessel after performing step (e) under normal pressure in the form of fine bubbles. The organic solvent phase is circulated between the container through the catalytic reduction catalyst disposed outside the container while maintaining the maintained state, and the amylanthraquinone in the organic solvent phase in the container is circulated. The method according to claim 1, further comprising the step (f) of regenerating the organic solvent solution of amylanthrahydroquinone into the container by reducing amylanthrahydroquinone to amylanthrahydroquinone. Production method.   The manufacturing method according to claim 3, wherein steps (b) to (f) are repeated one or more times.   The production method according to any one of claims 1 to 4, wherein the fine bubbles have 90% or more of the total number of bubbles having a particle diameter of 5 nm or more and less than 1000 nm.   The production method according to any one of claims 1 to 5, wherein the amyl group is bonded to the 2-position carbon of anthrahydroquinone.   The amylanthrahydroquinone is 2- (1,1-dimethylpropyl) anthrahydroquinone, 2- (1,2-dimethylpropyl) anthrahydroquinone, or 2- (1,1-dimethylpropyl) anthrahydroquinone and 2- (1 , 2-Dimethylpropyl) anthrahydroquinone. The production method according to claim 1, which is a mixture of anthrahydroquinone.   The method according to any one of claims 1 to 7, wherein the organic solvent is a mixed solvent of an alcohol having 8 to 10 carbon atoms and an aromatic hydrocarbon having a substituent. The production method according to any one of claims 1 to 8, wherein the aromatic hydrocarbon having a substituent is toluene, xylene, or trimethylbenzene.