JPH08296076A - Production of aqueous solution of hydrogen peroxide and device therefor - Google Patents

Abstract

PURPOSE: To provide a method and a device capable of producing hydrogen peroxide effective for a water treatment on-site and eliminating the need of a transport, etc., of a starting material. CONSTITUTION: A seawater 1 being a starting material is supplied to the first electrolytic cell 4 to electrolytically produce an alkaline aq. soln. and an acidic salt water, and an electrolysis of water is executed at the second electrolytic cell 7 while supplying the obtained alkaline aq. soln. and an oxygen-containing gas to produce the alkaline aq. soln. containing hydrogen peroxide. The obtained hydrogen peroxide-containing alkaline aq. soln. is mixed with the acidic salt water at need at a mixing tank 9 to obtain a neutral aq. sol. of hydrogen peroxide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for electrochemically producing hydrogen peroxide solution using salt water, mainly seawater as a raw material.

[0002]

2. Description of the Related Art Hydrogen peroxide is useful as an essential basic chemical in the food, pharmaceutical, pulp, fiber and semiconductor industries, and is conventionally synthesized by the anthraquinone method. Conventionally, for example, in power plants and factories that use seawater as cooling water, in order to prevent biofouling inside the condenser, seawater is directly electrolyzed to generate hypochlorous acid, and the hypochlorous acid is generated. It has been attempted to effectively utilize. However, if the hypochlorous acid is discharged as it is, the hypochlorous acid itself, and the organic chlorine compound and chlorine gas generated by decomposition are toxic, which poses a problem in environmental protection, and the regulation thereof is being strengthened.

On the other hand, it has been reported that the addition of a small amount of hydrogen peroxide to the cooling water has a good effect of preventing the adhesion of organisms, and that the addition of hydrogen peroxide is effective for maintaining the water quality of fish farms. Has been done. Moreover, even if hydrogen peroxide is decomposed, it is converted into harmless water and oxygen, and no environmental hygiene problems occur. However, hydrogen peroxide is unstable and cannot be stored for a long period of time, and there is an increasing demand for an on-site apparatus because of safety associated with transportation and measures against pollution.

In order to meet such demands, various methods for producing hydrogen peroxide have been conventionally proposed. U.S. Patent No. 3,
592,749 proposes several kinds of electrolysis devices, and U.S. Pat. No. 4,384,931 discloses an electrolysis method using an ion exchange membrane as a method for producing alkaline hydrogen peroxide solution. Further, U.S. Pat.No. 3,969,201 describes a hydrogen peroxide production apparatus comprising a carbon cathode having a three-dimensional structure and an ion exchange membrane. There will be restrictions on. Furthermore, Japanese Patent Publication No. 59-15990 discloses a method for producing hydrogen peroxide using a porous diaphragm material and a hydrophobic carbon cathode. In these methods, the transfer amount of the electrolyte solution from the anode chamber to the cathode chamber and It is difficult to control the speed and the operation is complicated.

A method for stably obtaining acidic hydrogen peroxide solution by supplying sulfuric acid to the intermediate chamber of an electrolytic cell divided into three chambers by using a cation exchange membrane and an anion exchange membrane [Journal of Elect
rochemical Society, vol.130, p1117 (1983)] and a method for obtaining hydrogen peroxide with high performance by using a membrane-electrode assembly as an anode has been proposed. However, these methods have a problem in economical efficiency because they require a unit power consumption. In addition, in any of these methods, hydrogen peroxide can be efficiently obtained in an alkaline aqueous solution atmosphere, so that it is necessary to supply an alkaline component as a raw material, and there is a problem in transporting this large amount of alkaline aqueous solution. As described above, a method and an apparatus for producing hydrogen peroxide by electrolysis that have been sufficiently satisfactory even at the present time have not been obtained.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and apparatus for producing hydrogen peroxide on-site with high efficiency using salt water as a raw material.

[0007]

According to the present invention, salt water is electrolyzed to produce an alkaline aqueous solution, and water is electrolyzed by adding the alkaline aqueous solution and an oxygen-containing gas to produce an alkaline aqueous solution containing hydrogen peroxide. A method for producing hydrogen peroxide solution, and an apparatus for producing hydrogen peroxide solution usable in the method.

Hereinafter, the present invention will be described in detail. In the present invention, salt water such as sodium chloride aqueous solution or potassium chloride aqueous solution, preferably seawater is electrolyzed to produce an alkaline aqueous solution as the first step, and the alkaline aqueous solution and the oxygen-containing gas obtained in the first step are produced as the second step. While adding, the water is electrolyzed to obtain an alkaline aqueous solution containing hydrogen peroxide. This second
The reason why the aqueous alkaline solution generated in the first step is added in the step is to increase the production efficiency of hydrogen peroxide. That neutral, the acidic range, simply 4 O _2-electron reduction that is O ₂ +2
H ₂ 0 + 4e → 4OH ⁻ progresses, and it becomes difficult to obtain H ₂ O ₂ . If the concentration of the aqueous alkali solution is too high, the generated caustic soda will not cause any problems, but its use may be limited due to the high concentration of alkali.

The first electrolytic cell is a three-chamber type electrolytic cell in which the electrolytic cell is divided into three chambers of an anode chamber, an intermediate chamber and a cathode chamber by using two ion exchange membranes, and one ion exchange membrane is used. It may be a two-chamber type electrolytic cell which is divided into an anode chamber and a cathode chamber by using it.
When using a three-chamber type electrolytic cell, the anode chamber and the intermediate chamber are partitioned using an anion exchange membrane, the cathode chamber and the intermediate chamber are partitioned using a cation exchange membrane, and salt water is supplied to the intermediate chamber. While energizing. Sodium ions in salt water supplied to the intermediate chamber pass through the cation exchange membrane and reach the cathode chamber, where they combine with hydroxide ions generated by electrolytic reduction of water to form alkali hydroxide, and the catholyte solution It becomes an alkaline aqueous solution. Although hydrogen is generated in this normal cathode reaction, hydrogen can be converted to water by advancing the electrolysis while supplying oxygen gas to suppress the generation of hydrogen and reduce the cell voltage.

On the other hand, chloride ions in the salt water supplied to the intermediate chamber pass through the anion exchange membrane to reach the anode chamber, and generate chlorine gas and hypochlorous acid. If you do not want to generate chlorine gas or hypochlorous acid, you can use a cation exchange membrane as the ion exchange membrane that separates the intermediate chamber and the anode chamber, and chlorine ions cannot permeate into the anode chamber or the cathode chamber. , Becomes hydrochloric acid together with hydrogen ions supplied from the anode side, and is discharged from the intermediate chamber as acidic salt water. In the embodiment in which the cation exchange membrane separates the anode chamber and the intermediate chamber, oxygen is generated by electrolytic oxidation of normal water in the anode chamber, but electrolysis proceeds while supplying hydrogen gas as in the cathode reaction described above. As a result, the oxygen generated can be converted into water and the generation of oxygen can be suppressed to reduce the cell voltage. The anodic reaction and cathodic reaction in the first electrolytic cell are as follows. Anode: 2H ₂ 0 → O ₂ + 4H ⁺ + 4e or H ₂ →
2H ⁺ + 2e Cathode: 2H ₂ 0 + 2e → H ₂ + 2OH ⁻ or O ₂ +
H ₂ O + 4e → 4OH ^{− When the} above-mentioned two-chamber electrolysis cell is used as the first electrolysis cell, electrolysis is performed while supplying salt water to the anode cell to obtain an alkaline aqueous solution in the cathode cell. However, since chlorine gas is generated in the anode chamber, acidic salt water for neutralizing the alkalinity described later cannot be obtained.

Then, the alkaline aqueous solution generated in the cathode chamber is supplied to the second electrolytic cell. The second electrolytic cell preferably has a two-chamber type electrolytic cell in which an anode chamber and a cathode chamber are partitioned by a single diaphragm such as an ion exchange membrane, and when a neutral membrane or an anion exchange membrane is used as the diaphragm. The alkaline aqueous solution may be supplied to either the anode chamber or the cathode chamber. If a cation exchange membrane is used as the diaphragm, it is supplied to the cathode chamber. When electricity is supplied to the cathode chamber while supplying the oxygen-containing gas, hydrogen peroxide is produced in the cathode chamber according to the following reaction formula. Anode: 2H ₂ 0 → O ₂ + 4H ⁺ + 4e or H ₂ → 2
H ⁺ + 2e cathode: O ₂ + H ₂ 0 + 2e → OH ⁻ + HO ₂ ⁻ (hydrogen peroxide)

The hydrogen peroxide obtained in the second electrolytic cell is obtained as an alkaline aqueous solution because it is dissolved in an alkaline aqueous solution containing hydroxide ions which are simultaneously produced, but when an aqueous solution in a neutral region is desired, the first Alternatively, it may be mixed with acidic water obtained in the anode chamber of the second electrolytic cell. Next, members constituting each of the above-described electrolytic cells and operating conditions will be described. First
As for the electrode in both the second electrolytic cell and the plate, any ordinary plate-shaped or porous electrode or gas electrode can be used. Oxygen generating anode is a plate-like or porous electrode used as the anode, titanium, niobium, wire mesh having corrosion resistance such as tantalum, powder sintered body, on a substrate such as a metal fiber sintered body, platinum,
A catalyst composed of a noble metal such as iridium or ruthenium or an oxide thereof can be manufactured by carrying it by a thermal decomposition method, a fixing method with a resin, a composite plating method or the like so that the carried amount becomes about 10 to 500 g / m ^2. .

Similarly, in the case of a hydrogen generating cathode, a catalyst composed of a noble metal such as platinum, iridium, ruthenium or an oxide thereof is used at a rate of 1 to 500 g / on a substrate such as a nickel sintered body by a thermal decomposition method or the like. It can be manufactured by carrying so that the carried amount is about m ² . In the case of hydrogen gas anode, titanium, niobium, tantalum, carbon or other corrosion-resistant mesh, powder sintered body, fiber sintered body or other base material, platinum, iridium or other noble metal or their oxides or A catalyst composed of carbon can be produced by carrying it by a thermal decomposition method, a fixing method with a resin, a composite plating method or the like so as to have a carried amount of about 10 to 500 g / m ² . In order to rapidly supply and remove the reaction product gas and liquid, it is preferable to disperse and carry a hydrophobic or hydrophilic material.

Similarly, in the case of an oxygen gas cathode, gold, silver, and the like are formed on a base material such as a corrosion-resistant mesh body, powder sintered body, fiber sintered body, etc., such as stainless steel, zirconium, silver, and carbon.
Noble metals such as platinum and iridium or their oxides and /
Alternatively, a catalyst composed of carbon can be produced by carrying it by a thermal decomposition method, a fixing method with a resin, a composite plating method or the like so as to have a carried amount of about 10 to 500 g / m ² . It is preferable to disperse and carry a hydrophobic or hydrophilic material as in the case of the hydrogen gas anode. The ion exchange membrane to be used may be either a fluororesin type or a hydrocarbon resin type, but the former is preferable from the viewpoint of corrosion resistance. The ion exchange membrane has a function of preventing each ion generated at the anode and the cathode from being consumed by the counter electrode, and has a function of promptly promoting electrolysis even when the conductivity of the liquid is low as in the present invention.

In the case of the above-mentioned gas electrode, a catholyte chamber may be provided between the ion exchange membrane and the cathode, and an anolyte chamber may be provided between the anode and the membrane, but when the conductivity of the solution is low, the cell voltage There are many disadvantages such as an increase in the number, a complicated tank structure, and a need for gas-liquid separation performance of each gas electrode. Therefore, the structure in which the electrode is bonded to the ion exchange membrane is most preferable. In the case of the present invention, the anode chamber can be a substantial gas chamber, but the cathode chamber is in a gas-liquid mixed state because the alkaline aqueous solution and the hydrogen peroxide solution are generated. When it is necessary to bond the electrode and the ion exchange membrane, they may be mechanically bonded in advance, or pressure may be applied during electrolysis. The pressure is preferably 0.1 to 30 kgf / cm ² .

As the raw material, hydrogen gas or oxygen gas may be a commercially available cylinder, but may be one produced by electrolysis of water in a separately installed electrolytic cell, and may be generated in the first electrolytic cell described above. Most preferably, hydrogen and oxygen gases are used. When an electrolysis tank is separately installed, it is preferable to use an electrolysis method in which electrodes are bonded to both sides of the ion exchange membrane and pure water is used as a raw material. From the viewpoint of economy, this electrolytic cell can be integrated with the above-mentioned electrolytic cell of the present invention. Depending on the field of use of the present invention, it is possible to generate ozone gas from the anode of this electrolytic cell, and it is desirable to have such a configuration from the viewpoint of effective use of energy. It is recommended that the hydrogen supply amount is about 1.2 times the theoretical amount, and the oxygen supply amount is 1.2 to 100 times the theoretical amount.

The thickness of the intermediate chamber of the above-mentioned first electrolytic cell should be made as thin as possible in order to reduce the resistance loss, but the pressure loss of the pump at the time of supplying salt water is made small and the pressure distribution is kept uniform. Therefore, it is preferably 1 to 10 mm, and it is preferable to insert a spacer having excellent insulation and corrosion resistance so that the ion exchange membranes on both sides of the intermediate chamber do not come into contact with each other. When the decomposition rate of salt water in the first electrolytic cell increases, the concentration of protons increases and the transport number of cations such as sodium to the cathode side decreases. Therefore, the decomposition rate is 40-80%
It is preferable to maintain at. When seawater is used as the salt water, it is desirable to protect the ion exchange membrane by removing calcium, magnesium, heavy metal ions, SS and solids which adversely affect the membrane characteristics in advance. For this pretreatment, in addition to installing a strainer and a filter,
It is effective and preferable to inject a part of the alkaline aqueous solution generated in the first electrolytic cell into the water inlet to precipitate the ions.

The operating condition of the first electrolytic cell is that the temperature is 5 to 40.
C., the current density is 1 to 50 A / dm.sup.2, and the concentration of salt water supplied to the intermediate chamber is preferably ²⁰ to 300 g / liter. If the concentration of the alkaline aqueous solution generated under such conditions is too high, the reverse effect may occur if it is used as it is. Therefore, dilute it with pure water and adjust it to the required concentration of the alkaline aqueous solution in the second electrolytic cell. Although it depends on the intended use, it is preferable to add an alkaline aqueous solution having a pH of 10 or more and a concentration of 35% or less. The material of the second electrolytic cell is glass lining material, carbon, corrosion resistant titanium, stainless steel, PT from the viewpoint of durability and stability of hydrogen peroxide.
FE resin and the like are preferable. The first and second electrolytic cells may be integrated depending on the conditions.

The method and apparatus of the present invention will be illustrated with reference to the accompanying drawings, but the present invention is not limited thereto. FIG. 1 is a flow chart illustrating the method of the present invention. The seawater 1 in a strainer 2 for storing seawater 1 as a raw material and removing solids by filtration or the like is supplied by a first electrolyzer 4 by a pump 3 and electrolyzed in the first electrolyzer 4, Aqueous alkaline solution and acidic seawater are produced. Part of the alkaline aqueous solution generated in the first electrolysis tank 4 is circulated to the strainer 2 through a circulation line 5,
The remaining alkaline aqueous solution is supplied to the second electrolytic cell 7 through the supply line 6. Normal water electrolysis is carried out in the second electrolysis tank 7, but the alkaline aqueous solution supplied to the electrolysis tank promotes the production of hydrogen peroxide, so that high-concentration hydrogen peroxide is produced and contains hydrogen peroxide. It is taken out of the second electrolytic cell 7 as an alkaline aqueous solution and supplied to the mixing tank 9 through the mixing line 8. On the other hand, the acidic salt water generated in the first electrolysis tank 4 is supplied to the mixing tank 9 through a bypass line 10 and mixed with the alkaline aqueous solution containing hydrogen peroxide to form a substantially neutral hydrogen peroxide solution. Taken out of the mixing tank 9.

FIG. 2 is a vertical sectional view of the first electrolytic cell of FIG. 1, and FIG. 3 is a vertical sectional view of the first electrolytic cell of FIG. The first electrolyzer 4 is composed of two cation-exchange membranes 11 and 12 for the anode chamber 13,
It is divided into an intermediate chamber 14 and a cathode chamber 15, and a mesh-like spacer 16 is housed in the intermediate chamber 14. On the anode surface side of the cation exchange membrane 11 on the side of the anode chamber 13, there is a porous anode 17 formed by supporting a catalyst such as a noble metal oxide on a base material such as titanium, and on the side of the cathode chamber 15 cations. On the cathode side of the exchange membrane 12, a porous cathode formed by supporting a catalyst such as platinum on a substrate such as titanium.
18 are installed in close contact with the cation exchange membrane. Pure water supply port 19 and anolyte and oxygen gas outlet 20 are installed on the lower and upper side surfaces of the anode chamber, respectively, and salt water supply port 21 and salt water outlet 22 are installed on the lower surface and upper surface of the intermediate chamber, respectively. Furthermore, on the lower and upper side surfaces of the cathode chamber,
A pure water supply port 23 and an alkaline aqueous solution extraction port 24 are provided respectively.

The second electrolytic cell 7 is divided into an anode chamber 26 and a cathode chamber 27 by a cation exchange membrane 25, and the cation exchange membrane is used.
On the anode chamber side of 25, there is a porous anode 28 formed by supporting a catalyst such as a noble metal oxide on a substrate such as titanium, and on the cathode chamber side of the cation exchange membrane 25 a substrate such as titanium. Porous cathodes 29 carrying catalysts such as carbon and gold are installed in close contact with the cation exchange membrane. Hydrogen gas and anolyte supply port 30 and anolyte outlet 31 are installed on the upper and lower side surfaces of the anode chamber, respectively, and oxygen and an alkaline aqueous solution taken out from the outlet 24 are provided on the lower and upper side surfaces of the cathode chamber. A supply port 32 and an alkaline aqueous solution extraction port 33 containing a hydrogen peroxide solution are installed. Both electrolytic cells 4 and 7 are arranged as shown in the flow chart of FIG. 1 to produce hydrogen peroxide.

[0022]

EXAMPLES Next, examples of production of hydrogen peroxide solution according to the present invention will be described, but the examples do not limit the present invention.

Example 1 A gas-liquid permeable porous titanium anode coated with an iridium oxide powder catalyst and a nickel porous cathode coated with a ruthenium oxide powder catalyst each having an electrode area of 0.2 dm ² were used as an anode chamber of an electrolytic cell. And accommodated in the cathode chamber,
An intermediate chamber having a thickness of 3 mm between the cation exchange membrane Nafion 117 (manufactured by DuPont) and the cathode was closely contacted with the cation exchange membrane Nafion 350 (manufactured by DuPont). Was formed. In the intermediate chamber, a polypropylene net laminate was provided as a spacer, and then the whole was tightened to form a first electrolytic cell as shown in FIG.

The positive electrode chamber, the intermediate chamber and the negative electrode chamber of the first electrolyzer are in the order of 1 cc of pure water, 10 cc of 30 g / liter sodium chloride aqueous solution and 3 cc of pure water, respectively. Electrolysis was carried out at a temperature of 40 ° C and a current of 1 A while supplying the solution at a cell voltage of 2.5 V, and a 25 g / liter aqueous solution of alkali (sodium hydroxide) was obtained with a current efficiency of 80% from the cathode chamber outlet. From the outlet of the anode chamber, a 25 g / liter aqueous solution of acidic salt was obtained with a current efficiency of 80%. Electrolysis in which a gas-liquid permeable carbon gas anode coated with a platinum catalyst having an electrode area of 0.2 dm ² and a carbon gas cathode coated with a gold catalyst were partitioned with a cation exchange membrane Nafion 117 (manufactured by DuPont). The cells were housed in the anode chamber and the cathode chamber of the cell so as to be in close contact with the cation exchange membrane, and the whole was tightened to form a second electrolytic cell as shown in FIG.

In addition to hydrogen generated in the cathode chamber of the first electrolytic cell, hydrogen gas from a commercial industrial hydrogen cylinder was supplied to the anode chamber of the second electrolytic cell at a total of 10 ml / min, while the cathode In the chamber, 500 ml / min of oxygen gas from an industrial oxygen cylinder and the gas produced in the first electrolyzer 25
When electrolysis was carried out at a temperature of 30 ° C. and a current of 1 A while supplying 1 ml / min of an alkaline aqueous solution of g / liter, the cell voltage was 1.5 V, and from the cathode chamber outlet
An alkaline aqueous solution containing 10 g / liter of hydrogen peroxide was obtained with a current efficiency of 95%. By mixing the aqueous solution with the acidic salt water produced in the first electrolyzer, an almost neutral 0.5
% Aqueous hydrogen peroxide solution was obtained at a rate of 10 cc / min.

[0025]

Example 2 The same first electrolytic cell as in Example 1 was constructed, and 1 cc of pure water and 30 g / liter of seawater were successively supplied to the anode chamber, the intermediate chamber and the cathode chamber of the first electrolytic cell, respectively. 10 per minute
While supplying cc and pure water at a rate of 3 cc / min,
When electrolysis was performed at 40 ° C and a current of 2 A, the cell voltage was 4.5.
V, a 25 g / liter aqueous alkaline solution was obtained from the cathode chamber outlet with a current efficiency of 80%, and 25 from the anode chamber outlet.
g / l of acidic seawater was obtained with a current efficiency of 60%. A part of the alkaline aqueous solution generated at this time was injected into a tank of raw material seawater to precipitate calcium, magnesium and heavy metal ions. The SS and solids were removed by a strainer and a filtration filter as a pretreatment.

The same second electrolysis cell as in Example 1 was constructed, and in addition to hydrogen generated in the cathode cell of the first electrolysis cell, an anode cell of the second electrolysis cell was supplied from a commercially available industrial hydrogen cylinder. Hydrogen gas was supplied at a total of 10 ml / min, while oxygen gas from an oxygen concentrator (OA-2L manufactured by Nippon Oxygen Co., Ltd.) was generated in the cathode chamber at 2 liters / min and 25 g / liter of the first electrolytic cell. Electrolysis was carried out at a temperature of 30 ° C. and a current of 1 A while supplying 1 ml / min of the alkaline aqueous solution, and the cell voltage was 1.5 V, and 10 V from the cathode chamber outlet.
An alkaline aqueous solution containing g / l hydrogen peroxide was obtained with a current efficiency of 95%. By mixing the aqueous solution with the acidic salt water produced in the first electrolyzer, an almost neutral 0.5
% Aqueous hydrogen peroxide solution was obtained at a rate of 10 cc / min.

[0027]

The method of the present invention is characterized in that salt water is electrolyzed to produce an alkaline aqueous solution, and water is electrolyzed while adding the alkaline aqueous solution and an oxygen-containing gas to produce an alkaline aqueous solution containing hydrogen peroxide. It is a method for producing hydrogen peroxide solution. According to this method of the present invention, hydrogen peroxide water, which is effective for sterilizing cooling water, fish farm water, etc., can be produced by using only salt water such as sea water and pure water as raw materials. Unlike hypochlorous acid, which has been conventionally used for sterilizing cooling water such as seawater, this hydrogen peroxide easily decomposes and hardly remains, and since the decomposition products are water and oxygen, it is environmentally friendly. There is no adverse effect.

Since the alkaline aqueous solution produced in the first stage is added in the second stage to promote the production of hydrogen peroxide, the current efficiency of hydrogen peroxide production increases, and a large amount of hydrogen peroxide is produced as compared with the conventional case. Hydrogen peroxide can be obtained. Further, since this alkaline aqueous solution is produced on-site, there is no problem in transportation. Furthermore, since the method of the present invention does not require anything other than an electrolytic cell and salt water and pure water as raw materials, on-site production can be easily performed, and the produced hydrogen peroxide can be used as it is for sterilization and the like. It can also overcome the drawback of easy disassembly. Further, as described above, since the raw materials are only salt water and pure water, it is necessary to prepare only pure water in the case of cooling water and its equipment when using seawater in which hydrogen peroxide is widely used for sterilization. Not only is it cost-effective, it costs little, it is easy to transport, and there is no need to consider decomposition of substances during transportation. Provided.

Depending on the application, neutral hydrogen peroxide water may be necessary, but in the three-chamber electrolysis of the present invention, acidic salt water is also by-produced, and this acidic salt water is used as the above-mentioned alkaline aqueous solution containing hydrogen peroxide. By mixing, almost neutral hydrogen peroxide can be obtained. The apparatus of the present invention comprises a first electrolytic cell for electrolyzing salt water to produce an alkaline aqueous solution, and a second electrolytic cell for electrolyzing while supplying the alkaline aqueous solution and an oxygen-containing gas to produce an alkaline aqueous solution containing hydrogen peroxide. An apparatus for producing hydrogen peroxide water, comprising:

By using this apparatus, an aqueous solution containing a large amount of hydrogen peroxide can be obtained as compared with the conventional method, similarly to the above-mentioned method of the present invention. When the electrode to be used is a gas electrode and electrolysis is performed while supplying hydrogen gas or oxygen gas, the generation of oxygen gas and hydrogen gas can be suppressed, respectively, and the cell voltage can be reduced.

[Brief description of drawings]

FIG. 1 is a flow chart illustrating the method of the present invention.

2 is a vertical cross-sectional view of the first electrolytic cell of FIG.

3 is a vertical cross-sectional view of the first electrolytic cell of FIG.

[Explanation of symbols]

1 ... Sea water 2 ... Strainer 3 ... Pump 4 ... First electrolysis tank 7 ... Second electrolysis tank 9 ... Mixing tank 11, 12 ...
・ Cation exchange membrane 13 ・ ・ ・ Anode chamber 14 ・ ・ ・ Intermediate chamber
15 ... Cathode chamber 16 ... Spacer 17 ... Porous anode 18 ... Porous cathode 25 ... Cation exchange membrane
26 ... Anode chamber 27 ... Cathode chamber 28 ... Porous anode 29 ... Porous cathode

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[Procedure amendment]

[Submission date] April 28, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

FIG. 2 is a vertical sectional view of the first electrolytic cell shown in FIG . 1 , and FIG . 3 is a vertical sectional view of the second electrolytic cell shown in FIG. The first electrolyzer 4 is composed of two cation-exchange membranes 11 and 12 for the anode chamber 13,
It is divided into an intermediate chamber 14 and a cathode chamber 15, and a mesh-like spacer 16 is housed in the intermediate chamber 14. On the anode surface side of the cation exchange membrane 11 on the side of the anode chamber 13, there is a porous anode 17 formed by supporting a catalyst such as a noble metal oxide on a base material such as titanium, and on the side of the cathode chamber 15 cations. On the cathode side of the exchange membrane 12, a porous cathode formed by supporting a catalyst such as platinum on a substrate such as titanium.
18 are installed in close contact with the cation exchange membrane. Pure water supply port 19 and anolyte and oxygen gas outlet 20 are installed on the lower and upper side surfaces of the anode chamber, respectively, and salt water supply port 21 and salt water outlet 22 are installed on the lower surface and upper surface of the intermediate chamber, respectively. Furthermore, on the lower and upper side surfaces of the cathode chamber,
A pure water supply port 23 and an alkaline aqueous solution extraction port 24 are provided respectively.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

FIG. 3 is a vertical cross-sectional view of the second electrolytic cell of FIG.

Front page continuation (72) Inventor Shuhei Wakita 5-9-8 Tsujido Motomachi, Fujisawa City, Kanagawa Prefecture (72) Inventor Takahiro Ashida 2-7-6 Nodai, Zama City, Kanagawa Prefecture (72) Inventor Yoshinori Nishiki Fujisawa, Kanagawa Prefecture 23, 1-1-1, Fujisawa, Ichi

Claims (4)

[Claims] 1. A hydrogen peroxide solution comprising electrolyzing salt water to produce an alkaline aqueous solution, and electrolyzing water while adding the alkaline aqueous solution and an oxygen-containing gas to produce an alkaline aqueous solution containing hydrogen peroxide. Manufacturing method. 2. Electrolyzing salt water to produce acidic salt water and an alkaline aqueous solution, and electrolyzing water while adding the alkaline aqueous solution and an oxygen-containing gas to produce an alkaline aqueous solution containing hydrogen peroxide. A method for producing hydrogen peroxide solution, which comprises mixing the alkaline aqueous solution containing the acid salt solution and an aqueous solution containing hydrogen peroxide having a pH of 5 to 9. 3. A first electrolysis tank for electrolyzing salt water to produce an alkaline aqueous solution, and a second electrolysis cell for electrolyzing while supplying the alkali aqueous solution and an oxygen-containing gas to produce an alkaline aqueous solution containing hydrogen peroxide. An apparatus for producing hydrogen peroxide water, comprising: 4. The first electrolytic cell is divided by two ion exchange membranes into an anode chamber having a porous or gas anode, a cathode chamber having a porous or gas cathode, and an intermediate chamber formed between both electrode chambers. The apparatus for producing hydrogen peroxide solution according to claim 3, wherein salt water is supplied to the intermediate chamber, acidic salt water is obtained in the anode chamber, and an alkaline aqueous solution containing hydrogen peroxide is obtained in the cathode chamber.