JP5370543B2 - Hydrogen peroxide production apparatus and air conditioner, air purifier and humidifier using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for producing hydrogen peroxide that can efficiently produce hydrogen peroxide using water and an oxygen-containing gas, and to provide an air conditioner, an air cleaner and a humidifier that use the hydrogen peroxide produced by the device for cleaning. <P>SOLUTION: The device for producing hydrogen peroxide includes: an electrolytic cell 1 including an electrolyte membrane 2 having hydrogen ion conductivity, an anode electrode 3 disposed in contacting with a first surface of the electrolyte membrane 2 and a cathode electrode 4 disposed in contacting with a second surface of the electrolyte membrane 2; a power source 24 for applying a DC voltage to the anode electrode 3 and the cathode electrode 4; an electrolytic bath 7, a bottom surface of which is constituted of the electrolytic cell 1, and which stores water; a hydrogen peroxide collecting tank 22 provided below the cathode electrode 4; a gas feeding pipe 18 immersed into the water in the hydrogen peroxide collecting tank 22 to generate bubbles; and an oxygen-containing gas feeding device 17 for feeding the oxygen-containing gas to the gas feeding pipe 18, thereby efficiently producing hydrogen peroxide. <P>COPYRIGHT: (C)2013,JPO&amp;INPIT

Description

  The present invention relates to, for example, an apparatus for electrochemically producing hydrogen peroxide from a gas containing oxygen and water, and an air conditioner, an air cleaner and a humidifier using the apparatus.

  In recent years, hydrogen peroxide has a bleaching and oxidizing action, and is widely used for foods, pharmaceuticals and other industrial purposes. In addition, sterilization effects and sterilization effects are also attracting attention, and household appliances are also used in washing machines, air purifiers, etc. to create a clean and comfortable environment using their bactericidal and antifungal properties. The application of is expected. Conventionally, hydrogen peroxide is produced by an electrochemical reaction using an ion exchange membrane. For example, in the hydrogen peroxide production apparatus according to the invention of Patent Document 1, at least a part of a pair of electrodes is immersed in an electrolyte solution stored in an electrolytic cell, and hydrogen peroxide is generated in the electrolyte solution by electrochemical treatment. doing. By using a material containing Ta, Pt or the like as the electrode material on the electrode side where hydrogen peroxide is generated, oxygen reduction proceeds efficiently, and hydrogen peroxide can be produced. A porous membrane capable of gas diffusion is installed on the electrode side where hydrogen peroxide is generated, and oxygen is introduced from the gas phase into the liquid phase (water) and is electrochemically reduced.

  In the hydrogen peroxide production apparatus according to the invention of Patent Document 2, an electrolytic cell separated into a gas chamber and an electrolytic chamber by a gas diffusion electrode is formed, an insoluble metal electrode is installed as an anode in the electrolytic chamber, and seawater is The hydrogen gas is generated in seawater by electrolysis while supplying air to the gas chamber. The gas diffusion electrode is a semi-hydrophobic gas diffusion electrode comprising a hydrophilic layer carrying an electrode material and a water-repellent gas diffusion layer, wherein the electrode material is carbon and / or gold. Oxygen is introduced from the gas phase into the liquid phase (seawater) through the gas diffusion layer and is electrochemically reduced.

JP 2005-146344 A Japanese Patent No. 3689541

  However, in the conventional method for producing hydrogen peroxide, when hydrogen peroxide is generated using water and an oxygen-containing gas, water on the surface of the cathode electrode inhibits oxygen diffusion. There is a problem that the generation characteristics of the above cannot be obtained. In addition, when only oxygen is supplied, the conduction rate of hydrogen ions in the hydrogen ion conductive membrane is remarkably lowered, and there is a problem that sufficient hydrogen peroxide generation characteristics cannot be obtained.

  The present invention has been made to solve the above-described problems, and a hydrogen peroxide production apparatus capable of efficiently producing hydrogen peroxide using water and an oxygen-containing gas, and a peroxidation produced thereby. The object is to provide an air conditioner, an air cleaner and a humidifier that use hydrogen for cleaning.

  In order to solve the above problems, an apparatus for producing hydrogen peroxide according to the present invention includes an electrolyte membrane having hydrogen ion conductivity, an anode electrode disposed in contact with the first surface of the electrolyte membrane, and an electrolyte membrane. An electrolysis cell having a cathode electrode disposed in contact with the second surface, a power source for applying a DC voltage to the anode electrode and the cathode electrode, and the electrolysis cell constitutes a part of the bottom surface to store water. An electrolytic cell, a hydrogen peroxide recovery tank installed below the cathode electrode, a bubbling means immersed in water in the hydrogen peroxide recovery tank to generate bubbles, and a gas supply for supplying oxygen-containing gas to the bubbling means And a droplet is formed on the surface of the cathode electrode by water droplets generated by bubbles.

  According to a fifth aspect of the present invention, the air conditioner has a function of cleaning the heat exchanger using hydrogen peroxide produced in the hydrogen peroxide production apparatus.

  The structure of claim 7 is an air purifier having a function of sterilizing air using hydrogen peroxide produced in a hydrogen peroxide production apparatus.

  The configuration of claim 9 is a humidifier having a function of cleaning the humidifying element using hydrogen peroxide produced in the hydrogen peroxide production apparatus.

  According to the present invention, it is possible to supply and diffuse a sufficient amount of oxygen to the cathode electrode by simultaneously supplying the oxygen-containing gas and water to the cathode electrode, and to obtain high hydrogen ion conductivity in the ion conductive membrane. By making it possible, the contact probability between oxygen and hydrogen ions at the cathode electrode is increased, and a remarkable effect that the conventional apparatus does not have such as hydrogen peroxide generation efficiency is improved.

Hereinafter, a hydrogen peroxide production apparatus according to an embodiment of the present invention and an air conditioner, an air purifier, and a humidifier using the same will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a schematic cross-sectional view showing a hydrogen peroxide production apparatus according to Embodiment 1 of the present invention. FIG. 2 is a schematic cross-sectional view of an electrolysis cell portion of the hydrogen peroxide production apparatus.
As shown in FIG. 1, an electrolytic cell 1 of a hydrogen peroxide production apparatus is disposed so as to be in contact with one surface of a polymer electrolyte membrane 2 that is an electrolyte membrane having hydrogen ion conductivity. The anode electrode 3 and the cathode electrode 4 disposed so as to be in contact with the other surface of the polymer electrolyte membrane 2 are further formed. The anode electrode 3 has an anode terminal 5, and the cathode electrode 4 has a cathode terminal. 6 is attached, the electrolytic cell 1 is configured to form a part of the side wall of the electrolytic cell 7, and the polymer electrolyte membrane 2 is fixed and sealed to the electrolytic cell 7 through the O-ring 8 by the fixing flange 9. ing. Water 10 is stored in the electrolytic cell 7. The water supply means includes a spray device 11 having an ultrasonic generator 13 provided on the bottom surface of the water tank 12, and a water supply pipe 16 connected to the spray device 11, and oxygen-containing gas supply means includes oxygen. The contained gas supply device 17 and a gas supply pipe 18 having a gas blowing hole 19 connected to the oxygen-containing gas supply device 17 are configured. A hydrogen peroxide recovery tank 22 that receives droplets 21 containing hydrogen peroxide dropped from the cathode electrode 4 is installed below the cathode electrode 4. The electrolysis cell 1 is connected to a power source 24 for applying a DC voltage via an anode terminal 5 and a cathode terminal 6.

  First, a specific material configuration and manufacturing method of a hydrogen peroxide production apparatus and an electrolytic cell will be described with reference to FIGS. As shown in FIG. 2, the electrolytic cell 1 has a structure in which a polymer electrolyte membrane 2 is sandwiched between a cathode electrode 4 composed of an anode electrode 3, carbon fibers 4a, and a catalyst mixed layer 4b.

The anode electrode 3 is composed of an oxidation catalyst that promotes the oxidation reaction of the substrate and water. As a base material, a cloth (radius 50 mm) having a density of 200 g / cm ² made of a sintered body of titanium (Ti) metal fiber (fiber diameter 20 μm and a sintered body incorporating a single fiber having a length of 50 to 100 mm). , A thickness of 300 μm) or an expanded metal having a mesh structure made of titanium. The anode electrode 3 is formed by plating platinum (Pt) or iridium oxide (IrO ₂ ) serving as a catalyst at a density of 0.25 to ² mg / cm ^{2 on} the surface in contact with the polymer electrolyte membrane 2 of the substrate. Since the oxidation reaction of water proceeds only at the interface between the oxidation catalyst formed on the substrate and the polymer electrolyte membrane 2, the density of the mesh affects the electrolysis performance when using expanded metal as the substrate. Specifically, it is preferable to use an expanded metal having 10 or more holes per inch.

The cathode electrode 4 is composed of a carbon-based substrate and a reduction catalyst that promotes the reduction reaction of oxygen. As the carbon-based substrate, carbon fiber 4a having a radius of 50 mm and a thickness of 200 μm (fiber diameter of about 5 to 50 μm, porosity 50 to 80%) is used. The carbon fiber 4a has been subjected to water repellency treatment. For example, it is treated with fluorine gas (room temperature, F ₂ partial pressure: 50 Torr), and the surface functional groups are substituted with C—F bonds. A reduction catalyst layer 4b in which carbon particles 26 and polymer electrolyte particles 27 are mixed is formed on the surface of the carbon fiber 4a in contact with the polymer electrolyte membrane 2. Specifically, a solution in which carbon powder and polymer electrolyte (perfluorosulfonic acid) are dispersed is mixed at a weight ratio of 10: 1 to 1:10, and the carbon fiber 4a has a thickness of 30 to 500 μm. After coating, it is dried at 50 ° C. under vacuum.

The material of the electrolytic cell 7 is made of, for example, acrylic resin, and the polymer electrolyte membrane 2 of the electrolytic cell 1 is clamped by the anode terminal 5 and the cathode terminal 6 at a surface pressure of 0.2 × 10 ⁴ to 1 × 10 ⁴ Pa. It has been. The anode terminal 5 and the cathode terminal 6 are obtained by welding a thin flat plate (radius 1 cm, thickness 2 mm) to a thin rod (outer diameter 2 mm, length 15 mm) perpendicularly to the disc from the center of the disc. Made of titanium (Ti). In order to prevent corrosion on the contact surface with the electrolysis cell 1, it is preferable to perform platinum (Pt) plating with a thickness of about 0.1 to 3 μm. In addition, when it is necessary to produce an electrode terminal at a relatively low cost, a carbon plate processed into a similar shape may be used.

Next, the operation principle of the hydrogen peroxide production method using the hydrogen peroxide production apparatus of Embodiment 1 will be described with reference to FIGS.
The electrolytic cell 1 is operated while applying a DC voltage of 1.5 to 10 V continuously or intermittently between the anode electrode 3 and the cathode electrode 4 by the power source 24. First, the water 10 stored in the electrolytic cell 7 passes through the anode electrode 3 and contacts the polymer electrolyte membrane 2. Then, water is absorbed by the polymer electrolyte membrane 2, diffuses in the polymer electrolyte membrane 2, and is held by the polymer electrolyte membrane 2. In the anode electrode 3, the supplied water is divided into oxygen (O ₂ ) and hydrogen ions (H ⁺ ) as shown in the reaction formula (1). When a DC voltage is applied by the power source 24, a current flows, oxygen molecules are generated from the surface of the anode electrode 3, and oxygen bubbles 25 are generated.
Anode: 2H ₂ O → O ₂ + 4H ⁺ + 4e ⁻ (1)
The polymer electrolyte membrane 2 is made of a material that does not transmit gas, is electrically insulating, and conducts only water and hydrogen ions (H ⁺ ), such as a perfluorosulfonic acid membrane. When oxygen-containing gas containing oxygen (O ₂ ) such as water and water (H ₂ O) are supplied, hydrogen ions conducted from the anode electrode 3 reaching the interface with the polymer electrolyte membrane 2 on the cathode electrode 4 Reducing substance caused by (H ⁺ ) and hydrogen ions (H ⁺ ) reacts with oxygen gas (O ₂ ), and hydrogen peroxide (H ₂ O ₂ ) is generated by the reduction reaction shown in the reaction formula (2). Is done. The generated droplets 21 containing hydrogen peroxide are dropped, recovered in a hydrogen peroxide recovery tank 22 and gradually accumulated.

Cathode: O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O ₂ (2)
The supply of oxygen gas to the cathode electrode 4 is performed by blowing oxygen gas sent from the oxygen-containing gas supply device 17 onto the surface of the cathode electrode 4 through the hole 19 of the gas supply pipe 18. Further, water is supplied to the cathode electrode 4 by spraying water 14 in the water tank 12 using water (15 kHz to 2 MHz) generated by the ultrasonic generator 13 into a mist-like water droplet 15 that is refined to a diameter of several μm. The water droplet 15 is sprayed from the supply pipe 16, is pressed against the surface of the cathode electrode 4 by the oxygen gas blown from the hole 19 of the gas supply pipe 18, and is attached as the liquid droplet 20.
Further, in the cathode electrode 4, the reaction (3) in which oxygen (O ₂ ) is further reduced to produce water (H ₂ O) and the hydrogen ion (H ⁺ ) are directly reduced to generate hydrogen (H ₂ ). Reaction formula (4) also proceeds.
Cathode: O ₂ + 4H ⁺ + 4e ⁻ → 2H ₂ O (3)
2H ⁺ + 2e ⁻ → H ₂ (4)

Furthermore, the state of the reaction will be described in detail with reference to FIG. In the reduction catalyst layer 4b of the carbon particles 26 and the electrolyte particles 27 adjacent to the polymer electrolyte membrane 2, the electrolyte particles 27 are three-dimensionally joined, and hydrogen ions (H ⁺ ) generated on the anode electrode 3 side are high. The light is transmitted through the molecular electrolyte membrane 2. Then, oxygen (O ₂ ) supplied from the cathode electrode 4 side receives electrons at the interface 28 (part indicated by a black dot) between the carbon particles 26 and the electrolyte particles 27 to generate hydrogen peroxide (H ₂ O ₂ ). The electrochemical reaction proceeds. In the present invention, as shown in the reaction formula (2), the purpose is to electrochemically reduce oxygen with hydrogen ions. Therefore, if the reduction catalyst layer 4b is covered with water, the oxygen supply rate is drastically reduced. In addition, the ability to generate hydrogen peroxide is reduced. Since the diffusion coefficients of oxygen in water and gas are about 1.6 × 10 ⁻⁹ (m ² / s) and 1 × 10 ⁻⁵ (m ² / s), respectively, the surface of the cathode electrode 4 was covered with water. In this case, the oxygen supply rate is reduced to 1 / 10,000, and as a result, the reaction formula (2) hardly proceeds.

The hydrogen ion conductivity of the polymer electrolyte membrane 2 increases in proportion to the relative humidity in the membrane, that is, the amount of water. In the case where the polymer electrolyte membrane 2 is a perfluorosulfonic acid membrane, at 20 ° C., 10 ⁻⁴ Scm ^{−1 at} 20% relative humidity, 2 × 10 ⁻³ Scm ⁻¹ at 40%, and 10 ^{−2 at} 60%. It changes greatly with Scm- ¹ . Therefore, even if oxygen is present sufficiently, if water is insufficient, the conduction rate of hydrogen ions is reduced, and the ability to generate hydrogen peroxide is reduced. When water is supplied to a part of the cathode electrode 4 and the other part is exposed to oxygen gas, even if a DC voltage is applied by the power supply 24, hydrogen ions accompanying the current are concentrated in the part immersed in water. However, hydrogen ions hardly conduct in the gas phase portion exposed to oxygen gas. In water with a large amount of hydrogen ion conduction, as described above, the solubility and diffusion rate of oxygen in water are very slow, so that sufficient hydrogen peroxide generation ability cannot be obtained. For this reason, it is important to supply constant water and oxygen to the cathode electrode 4.

  Therefore, when oxygen gas is dissolved in water, the dissolved oxygen concentration is limited to about 20 mg / L at the maximum, and the weight ratio of oxygen / water is 1 / 50,000. Alternatively, even if oxygen gas is introduced into water to generate bubbles of oxygen gas in water, the volume ratio of oxygen in water generally does not exceed 10%, and the weight ratio of oxygen / water is 1 / It is about 5,000. Thus, normally, in the state which mixed oxygen gas with water, the weight ratio of oxygen / water is 1 / 5,000 or less, and it is in the state where oxygen was very insufficient.

  On the other hand, the present inventors do not supply water to the cathode electrode as a mist-like water droplet as in the present invention, but supply it as mist-like water droplets together with oxygen gas to the cathode electrode. By adopting the supply method, the supply amount is controlled, and the weight ratio of oxygen / water is set to 1 / 5,000 or more, and both oxygen and water can be supplied to the cathode electrode in a high oxygen ratio state. did. Thereby, the production amount of hydrogen peroxide per unit current amount can be improved.

Next, with respect to the water supplied to the anode electrode 3 side, if cations due to metal ions such as calcium (Ca), magnesium (Mg), and potassium (K) are contained, the polymer electrolyte membrane 2 Since the hydrogen ion conduction speed is remarkably reduced because the internal hydrogen ions are replaced by cations, ion-exchanged water or ultrapure water can be used both when supplying liquid water directly and when supplying fine water. Is preferred. If it is tap water, it can be used if it is water from which calcite, trihalomethane, etc. have been removed by a filter, and its electric conductivity is 10 mScm ⁻¹ or less.

  Part of the voltage applied between the anode electrode 3 and the cathode electrode 4 is lost as Joule heat in the contact resistance or the polymer electrolyte membrane 2, and the temperature of the polymer electrolyte membrane 2, the anode electrode 3, or the cathode electrode 4 is increased. Let When the temperature rise is remarkable, the polymer electrolyte membrane 2 is deteriorated or deformed, and the anode electrode 3, the cathode electrode 4 and the polymer electrolyte membrane 2 are peeled off, which is not desirable. Therefore, heat generation can be suppressed by intermittently turning the voltage on and off. Specifically, it is desirable to operate at an ON time of about 0.2 to 5 times with an OFF time of 1 at intervals of 1 to 30 minutes.

  Moreover, if energy is given only to hydrogen ions by applying a pulsed voltage, loss due to heat can be suppressed. In such a case, it is preferable to turn on and off by continuously applying a pulse voltage of about 1 μsec to 10 msec.

  In the first embodiment, the case where the electrolysis cell 1 is installed vertically has been described. However, the electrolysis cell 1 may be installed horizontally, and the gas supply pipe 18 is also arranged horizontally in accordance therewith. The same effect can be obtained even if the hydrogen oxide recovery tank 22 is installed. Here, the case where the entire anode electrode 3 is immersed in the water 10 has been described. However, at least a part of the anode electrode 3 may be immersed and adjusted according to the amount of hydrogen peroxide generated. May be.

  Thus, according to the hydrogen peroxide production apparatus of the first embodiment, water is supplied to the cathode electrode as mist-like water droplets, and the oxygen gas is supplied together with the oxygen-containing gas and water. By supplying to the cathode electrode at the same time, a sufficient amount of oxygen can be supplied and diffused to the cathode electrode, and high hydrogen ion conductivity can be obtained in the ion conductive membrane, so that oxygen and hydrogen ions in the cathode can be obtained. There is a remarkable effect that the contact probability of the hydrogen peroxide increases and the generation efficiency of hydrogen peroxide increases.

[Example 1]
3 to 5 show measurement results of hydrogen peroxide generation characteristics according to Example 1 using the hydrogen peroxide production apparatus according to the first embodiment.
As a material constituting the electrolytic cell 1, the base material of the anode electrode 3 is an expanded metal made of titanium (mesh number 80 per square inch, wire diameter 0.1 mm), and the oxidation catalyst is iridium oxide (supporting density 0.6 mg). / Cm ² , formed by electroless plating). The cathode electrode 4 has a 1: 3 weight ratio of a solution in which carbon fiber (fiber diameter 10 μm, porosity 70%) is used as a base material and carbon powder and polymer electrolyte (perfluorosulfonic acid) powder are dispersed thereon. After mixing at a ratio and coating with a thickness of 50 to 400 μm, the reduction catalyst layer 4b was formed by drying under vacuum at 50 ° C. The polymer electrolyte membrane 2 is perfluorosulfonic acid.
As the generation conditions, the applied voltage is 2.0 to 2.2 V, the temperature is 25 ° C., the flow rate of oxygen gas to be introduced is 10 to 50 cc / min, the area of the anode electrode 3 and the cathode electrode 4 is 19 cm ² , Assuming that water is recovered from the air by cooling, 50 cc of ion-exchanged water at normal temperature was placed in the electrolytic cell 7. In addition, 100 cc of ion-exchanged water at room temperature was placed in the hydrogen peroxide recovery tank 22. Hydrogen peroxide generated at the cathode electrode 4 is recovered as droplets 21 and gradually accumulated in the hydrogen peroxide recovery tank 22. The change with time in the hydrogen peroxide concentration was measured using a wavelength in the range of 180 to 250 nm with an ultraviolet absorptiometer (not shown) attached to a part of the hydrogen peroxide recovery tank 22.

The temperature of the water 14 in the spraying device 11 was adjusted to control the amount of water droplets supplied from the water supply pipe 16 to change the water vapor concentration W1. The saturated water vapor concentration at a temperature of 25 ° C. of the cathode electrode 4 of the electrolytic cell 1 is defined as W2, and the degree of supersaturation is defined as W1 / W2.
FIG. 3 shows the change over time of the droplet diameter formed on the surface of the cathode electrode 4 when the amount of water droplets supplied is controlled so that the degree of supersaturation W1 / W2 is 1.7, 2.4, 3.3. Is shown. When the degree of supersaturation is 1.7 (A), a droplet 20 having a diameter of 20 μm is formed, and when the degree of supersaturation is 2.4 (B), a droplet 20 having a diameter of 50 μm is formed, and when the degree of supersaturation is 3.3 (C), time is required. Along with this, the droplet diameter increased to about 400 μm. When the degree of supersaturation was 1.01, a droplet 20 having a diameter of 1 μm was formed.
Next, FIG. 4 shows the results of measuring the hydrogen peroxide generation rate while adjusting the supersaturation degree W1 / W2 to keep the droplet diameter constant. Assuming that the hydrogen peroxide generation rate is 1 at a droplet diameter of 1 μm, it was 10 at a droplet diameter of 200 μm and 1 at a droplet diameter of 400 μm. When the droplet diameter is 1 μm or less, since water repellent treatment is performed, water does not permeate into the cathode electrode 4, so that the amount of hydrogen peroxide generated decreases rapidly.

  On the other hand, when the droplet diameter is 400 μm or more, the fusion of the droplets 20 progresses, and a part of the surface of the cathode electrode 4 is covered with water, so that the oxygen supply rate is drastically reduced. As a result, the amount of hydrogen peroxide generated is considered to decrease. Therefore, it has been found that it is desirable to form the droplets 20 having a diameter of 1 to 400 μm on the surface of the cathode electrode 4 by controlling the degree of supersaturation in the range of 1.01 to 3.3.

  In addition, the state of the droplet 20 formed on the cathode electrode 4 is observed with an optical microscope, and the presence of oxygen and water is determined from the droplet present on the surface of the cathode electrode 4 and the oxygen gas existing therearound by image analysis. The ratio (weight ratio) can be quantified. When droplets having a diameter of 1 to 400 μm were formed, the weight ratio of oxygen / water was found to correspond to 100/1 to 5,000 / 1. This revealed that the oxygen / water weight ratio should be adjusted to be 100/1 to 5,000 / 1 in order to increase the hydrogen peroxide production rate.

Embodiment 2. FIG.
FIG. 5 is a schematic cross-sectional view showing a hydrogen peroxide production apparatus according to Embodiment 2 of the present invention.
As shown in FIG. 5, the electrolytic cell 1 and the water supply pipe 29 are installed horizontally, and water 10 is stored in the electrolytic cell 7 that forms the bottom surface of the electrolytic cell 1. The water supply means includes an oxygen-containing gas supply device 17, a gas supply pipe 18 connected to the oxygen-containing gas supply device 17, a water tank 12 connected to the gas supply pipe 18, and a hole 30 connected to the water tank 12. The water supply pipe 29 is used, and the oxygen-containing gas supply means also serves as the water supply means. Further, a hydrogen peroxide recovery tank 22 for recovering droplets 21 containing hydrogen peroxide is installed below the cathode electrode 4. The same reference numerals as those in FIG. 1 denote the same or corresponding parts, and the description thereof will be omitted.

Next, the method for producing hydrogen peroxide in Embodiment 2 will be described. The water 14 in the water tank 12 is bubbled by the oxygen-containing gas supplied from the oxygen-containing gas supply device 17 through the gas supply pipe 18, thereby generating water droplets 15. The water droplets 15 are blown out from the holes 30 toward the cathode electrode 4 through the water supply pipe 29 and are uniformly formed as droplets 20 on the entire surface of the cathode electrode 4 installed horizontally. The water tank 12 is heated, and the water vapor concentration in the vicinity of the cathode electrode 4 exceeds the saturated water vapor concentration, resulting in a supersaturated state. Further, the oxygen-containing gas supplied from the oxygen-containing gas supply device 17 not only forms the water droplets 15 but also is supplied to the cathode electrode 4 as oxygen gas. Hydrogen peroxide is generated by the reaction shown by the equation (2) between the oxygen gas accompanying the droplet 20 and the hydrogen ions supplied from the polymer electrolyte membrane 2. The generated hydrogen peroxide is dissolved in the droplet 20 on the surface of the cathode electrode 4, and the droplet 21 containing hydrogen peroxide is dropped and recovered by the hydrogen peroxide recovery tank 22. Hydrogen peroxide is gradually accumulated in the hydrogen peroxide recovery tank 22. In addition, since the material configuration of the electrolytic cell 1 and the operation of the electrolytic cell 1 are the same as those in the first embodiment and the first embodiment, the description thereof is omitted.
In Embodiment 2, it is sufficient that the necessary oxygen-containing gas contains water vapor having a saturated water vapor concentration or higher at the surface temperature of the cathode electrode 4 of the electrolysis cell 1, and it is effective even when the electrolysis cell 1 is heated. is there.

  Thus, according to the hydrogen peroxide production apparatus of the second embodiment, as in the first embodiment, by supplying oxygen-containing gas and mist-like water droplets to the cathode electrode 4 at the same time, the amount required for the cathode electrode 4 The oxygen can be supplied and diffused, and high hydrogen ion conductivity can be obtained uniformly over the entire surface of the polymer electrolyte membrane 2, so that the contact probability between oxygen and hydrogen ions at the cathode electrode is increased, and the production efficiency of hydrogen peroxide is increased. It is possible to obtain an unprecedented remarkable effect such as increasing Furthermore, in the second embodiment, since the electrolysis cell 1 and the water supply pipe 29 are held horizontally, the droplets are uniformly formed on the surface of the cathode electrode 4, and high hydrogen peroxide generation efficiency can be obtained stably. The effect of being obtained.

Embodiment 3 FIG.
FIG. 6 is a schematic cross-sectional view showing a hydrogen peroxide production apparatus according to Embodiment 3 of the present invention.
As shown in FIG. 6, the electrolytic cell 1 and the gas supply pipe 18 are installed horizontally, and water 10 is stored in the electrolytic cell 7 that forms the bottom surface of the electrolytic cell 1. The water supply means to the cathode electrode includes an oxygen-containing gas supply device 17, a gas supply pipe 18 connected to the oxygen-containing gas supply device 17, and a hydrogen peroxide recovery tank 22 installed below the cathode electrode 4. The gas supply pipe 18 is arranged horizontally, has a hole 19 for blowing out an oxygen-containing gas, and is immersed in water 23 stored in a hydrogen peroxide recovery tank 22. The oxygen-containing gas supply means also serves as a water supply means. The same reference numerals as those in FIGS. 1 and 5 indicate the same or corresponding parts, and thus the description thereof is omitted.

  Next, the method for producing hydrogen peroxide in Embodiment 3 will be described. The oxygen-containing gas supplied from the oxygen-containing gas supply device 17 is blown out from the hole 19 of the gas supply pipe 18 and the water 23 of the hydrogen peroxide recovery tank 22 is bubbled to generate the bubbles 31 of the oxygen-containing gas. The oxygen gas is supplied to the cathode electrode. The water supply means supplies the droplets 20 formed on the surface of the cathode electrode 4 by the water droplets 32 containing the oxygen gas generated by the bubbles 31. The hydrogen peroxide recovery tank 22 is heated, and the water vapor concentration in the vicinity of the cathode electrode 4 exceeds the saturated water vapor concentration, resulting in a supersaturated state. Hydrogen peroxide is generated by the reaction shown by the equation (2) with the droplets 20, oxygen gas, and hydrogen ions supplied from the polymer electrolyte membrane 2. The generated hydrogen peroxide is dissolved in the droplet 20 on the surface of the cathode electrode 4, and the droplet 21 containing hydrogen peroxide is dropped and recovered by the hydrogen peroxide recovery tank 22. Hydrogen peroxide is gradually accumulated in the hydrogen peroxide recovery tank 22. Here, the water surface of the water 23 and the cathode electrode 4 are separated by a predetermined distance d. In addition, since the material configuration of the electrolytic cell 1 and the operation of the electrolytic cell 1 are the same as those in the first embodiment and the first embodiment, the description thereof is omitted.

  The gas supply pipe 18 uses a pipe made of a material that does not decompose hydrogen peroxide, and has a structure in which a plurality of holes 19 are opened toward the water surface. For example, when the size of the electrolytic cell 1 is about 50 mm in diameter, the inner diameter of the gas supply pipe 18 is preferably about 0.5 to 10 mm, but is determined depending on the amount of water stored in the hydrogen peroxide recovery tank 22. . A plurality of holes 19 having a diameter of about 0.1 to 2 mm are provided over the diameter of the cathode electrode 4. Although the diameter of the bubble 31 formed by the gas supply pipe 18 increases depending on the diameter of the hole 19, the diameter of the formed bubble is 0.5 mm or more even if it is 0.5 mm or less. In order for oxygen-containing gas to leave the gas supply pipe 18, the buoyancy of the bubbles 31 needs to exceed the surface tension of water, and even if fine bubbles of 0.5 mm or less are formed in the vicinity of the holes 19, the buoyancy is small. For this reason, the gas supply pipe 18 cannot be separated.

As the material of the gas supply pipe 18, specifically, when a hydrophilic material such as acrylic, vinyl chloride, glass, TiO ₂ , aluminum oxide, carbon, or the like is used, the bubbles 31 are easily separated from the holes 19, so that the gas supply pipe 18 is fine. Bubbles can be formed. Specifically, the bubbles can be made fine to about 0.1 mm diameter. If fine bubbles are formed, oxygen and water can be uniformly supplied to the surface of the cathode electrode 4 at the same time, so that a more stable operation of the electrolytic cell 1 can be realized. In addition to the above, the material for the hydrogen peroxide recovery tank 22 and the gas supply pipe 18 is preferably a material having a low hydrogen peroxide decomposition performance, such as general resin materials, titanium, carbon, glass, and gold. it can.

The interval between the holes 19 is preferably equal to about the diameter of the holes 19 or about 1 to 5 times the diameter. Further, the water droplet 32 that has reached the vicinity of the center of the cathode electrode 4 moves to the periphery while gradually merging. Therefore, in order to introduce the same amount of oxygen-containing gas over the entire surface of the cathode electrode 4, it is more desirable to arrange the peripheral density smaller than the center. Specifically, when the distance from the center of the cathode electrode 4 is r, the interval between the holes 19 is preferably decreased from the center toward the periphery so as to be proportional to r-1. Further, when the holes 19 are formed at equal intervals, if the distance from the center of the cathode electrode 4 is r, the hole diameter of the hole 19 is controlled to be proportional to r−0.5 from the center toward the periphery. Is desirable.
The amount of water in the hydrogen peroxide recovery tank 22, the water temperature, the flow rate of the oxygen-containing gas, and the distance d between the cathode electrode 4 and the water surface are determined according to the amount of hydrogen peroxide required.

  Thus, according to the hydrogen peroxide production apparatus of the third embodiment, bubbles are formed by bubbling from an oxygen-containing gas supply pipe arranged in water, and the cathode electrode together with water droplets containing the oxygen-containing gas generated at this time. By supplying oxygen, it is possible to supply and diffuse a necessary amount of oxygen to the cathode electrode, and to obtain high hydrogen ion conductivity uniformly over the entire surface of the polymer electrolyte membrane. The contact probabilities of the hydrogen peroxide and the hydrogen peroxide generation efficiency can be improved.

[Example 2]
The measurement result of the hydrogen peroxide production | generation characteristic by Example 2 using the hydrogen peroxide manufacturing apparatus of Embodiment 3 shown in FIG. 6 is shown.
As in Example 1, as the material constituting the electrolytic cell 1, the base material of the anode electrode 3 is titanium expanded metal (mesh number 80 per square inch, wire diameter 0.1 mm), and the oxidation catalyst is iridium oxide. (Support density 0.6 mg / cm ² , formed by electroless plating) was used. The cathode electrode 4 has a 1: 3 weight ratio of a solution in which carbon fiber (fiber diameter 10 μm, porosity 70%) is used as a base material and carbon powder and polymer electrolyte (perfluorosulfonic acid) powder are dispersed thereon. After mixing at a ratio and coating with a thickness of 50 to 400 μm, the reduction catalyst layer 4b was formed by drying under vacuum at 50 ° C. The polymer electrolyte membrane 2 is perfluorosulfonic acid.
As the generation conditions, the applied voltage is 2.0 to 2.2 V, the temperature is 25 ° C., the flow rate of oxygen gas to be introduced is 10 to 50 cc / min, the area of the anode electrode 3 and the cathode electrode 4 is 19 cm ² , Assuming that water is recovered from the air by cooling, 50 cc of ion-exchanged water at normal temperature was placed in the electrolytic cell 7. In addition, 100 cc of ion-exchanged water at room temperature was placed in the hydrogen peroxide recovery tank 22. Hydrogen peroxide generated at the cathode electrode 4 is gradually accumulated in the hydrogen peroxide recovery tank 22.

The distance from the cathode electrode 4 to the water surface of the water 23 in the hydrogen peroxide recovery tank 22 was defined as d (hereinafter referred to as the gap length), and d was adjusted by parallel translation with respect to the electrolytic cell 1. When the gap length d is positive, the cathode electrode 4 of the electrolysis cell 1 is present in the gas with the supply of the oxygen-containing gas stopped, and when d = 0, the cathode electrode 4 coincides with the water surface. On the other hand, when the gap length d is negative, the cathode electrode 4 corresponds to a state of being completely immersed in water.
FIG. 7 shows the result of measuring the hydrogen peroxide production rate (generated amount per unit time) in Example 2 with a solid line. The relative speed is shown assuming that the generation speed when the gap length d is 0 is 1. It was found that there is a region where the generation speed is specifically high when the gap length d is 0 to 20 mm, and the maximum is 10. In addition, when the gap length d was 20 mm or more, the generation rate rapidly decreased and gradually approached about 0.15. When the supply of the oxygen-containing gas is stopped, the hydrogen peroxide production rate becomes 0.1 when d = 10 mm and becomes 0 when d = 30 mm.

Next, for the purpose of examining the abundance ratio (weight ratio) of oxygen and water in the vicinity of the cathode electrode 4, visible laser light is irradiated in parallel with the water surface, and the state of the colored water droplets in the vicinity of the water surface is observed at a high speed from above the water surface. Images were taken with a camera at a rate of 1,000 frames per second. The image was analyzed to measure the density and size distribution of the water droplets with respect to the distance from the water surface. Since the water droplet contains oxygen-containing gas, the weight ratio of water and oxygen can be evaluated from image analysis at a distance from the water surface. Therefore, the ratio of oxygen and water with respect to the distance d (gap length) from the water surface where water droplets exist can be quantified by this method.
The result evaluated about the weight ratio of oxygen and water using the above-mentioned method is demonstrated. When the gap length d <0, the entire surface of the cathode electrode 4 is covered with water. However, since the water droplet 32 containing the oxygen-containing gas collides with the surface of the cathode electrode 4, the weight ratio of oxygen / water is 1/80. , 000, and a certain amount of hydrogen peroxide is obtained. When the weight ratio of oxygen to water with respect to the gap length d is measured in the range where the gap length d is 0 to 20 mm, the weight ratio of oxygen / water is 100/1 to 1 / 5,000 in the range of d = 0 to 20 mm. It was found to be in range. As a result of the increased contact probability of oxygen and hydrogen ions at the cathode electrode 4, it is considered that the hydrogen peroxide production rate has been rapidly improved. On the other hand, when the gap length is d> 20 mm, the oxygen / water weight ratio is 500/1 to 100/1, and only oxygen is supplied and water hardly reaches. It drops significantly. As a result, the production rate of hydrogen peroxide is drastically reduced. The amount of water in the hydrogen peroxide recovery tank 22, the water temperature, the flow rate of oxygen-containing gas, and the gap length d may be determined according to the amount of hydrogen peroxide required.

Example 3
The measurement result of the production rate of hydrogen peroxide according to Example 3 in which an additive is mixed with water 23 using the hydrogen peroxide production apparatus according to Embodiment 3 will be described.
As conditions for hydrogen peroxide generation, the applied voltage is 2.0 to 2.2 V, the temperature is 25 ° C., and the area of the anode electrode 3 and the cathode electrode 4 is 19 cm ² . Since the material which comprises the electrolytic cell 1 is the same as Example 1, description is abbreviate | omitted. FIG. 8 shows the result of comparison of the hydrogen peroxide generation rate in the case where 100 mg / L of acetic acid is added as an additive (A) and in the case of Example 2 where no additive is added (B). The dependence of the hydrogen peroxide production rate on the gap length d shows the same tendency as in Example 2, but the hydrogen peroxide production rate increased 2-3 times. This is presumably because finer water droplets can be formed at a high density as a result of suppressing fusion of water droplets containing oxygen-containing gas with the additive.

As a component of the additive mixed with the water 23 supplied to the cathode electrode 4 side, hydrophilic residues other than acetic acid and a carboxyl group (—OH, —NH ₂ (primary amine), —NH— (second amine), - N <(tertiary amine), - C (O) NH- ( peptide bond), - C (O) NH 2 ( primary amide), (- C (O) ) 2NH ( secondary amide) , (- C (O)) 3N ( third _{amide), - O -, - SO} 3 H, -PO4H, -F, -NO 2, -S (O) -, - with one of CN, etc.) Carboxylic acids can be used. Moreover, it is preferable to use it so that the density | concentration of a residue (carboxyl group) may be 0.001-1 mol / L with respect to water, and it is still more preferable to use it so that it may become 0.01-0.2 mol / L. When the concentration of the residue is lower than 0.001 mol / L, the diameter of the water droplet 32 containing the generated oxygen-containing gas tends to increase. When the concentration of the residue is higher than 1 mol / L, the air bubbles 31 that have risen tend not to disappear easily. Here, the concentration of the residue means a value obtained by multiplying the concentration of the molecule by the number of residues (carboxyl group in this example) in one molecule. The pH of the water is preferably 4 or less, and more preferably 3 or less. When the pH of water is larger than 4, the diameter of the generated water droplet 32 tends to increase. On the other hand, when an inorganic compound is added, it is preferable to use a strongly ionizable salt such as sodium chloride, potassium chloride, sodium sulfate, or potassium sulfate. The salt concentration is desirably 0.1% by weight or more.

Additives that prevent water droplet coalescence are selectively adsorbed on the surface of the water droplets. When the additive is dissolved in water, a minute charge is generated in the additive molecule, so that an electric double layer is formed on the surface of the water droplet. As a result, the entire water droplet behaves like being charged, and the water droplets are electrically repelled by repulsive force to prevent fusion. That is, the additive has an effect of adsorbing on the surface of the water droplet and forming an electric double layer.
When the water droplets 32 in contact with the cathode electrode 4 are made finer and denser by the additive, a sufficient amount of oxygen is supplied and diffused to the cathode electrode 4 and the hydrogen ion conductivity is more uniformly distributed over the entire surface of the ion conductive film. It becomes possible to obtain. As a result, the contact probability between oxygen and hydrogen ions in the cathode electrode 4 is increased, and a remarkable effect that is not possible in the past, such as an increase in hydrogen peroxide generation efficiency, can be obtained.

Embodiment 4 FIG.
FIG. 9 is a schematic cross-sectional view showing a hydrogen peroxide production apparatus according to Embodiment 4 of the present invention.
As shown in FIG. 9, the fourth embodiment is the same as the third embodiment in that the electrolytic cell 7 is inclined and the electrolytic cell 1 is installed at an angle θ with respect to the water surface of the water 23 in the hydrogen peroxide recovery tank 22. is there. The hole 19 of the gas supply pipe 18 is formed on the side close to the water surface of the cathode electrode 4. The same reference numerals as those in FIGS. 1 and 6 indicate the same or corresponding parts, and thus the description thereof is omitted.

When the water droplets 32 containing the oxygen-containing gas generated by the oxygen-containing gas blown from the hole 19 of the gas supply pipe 18 reach the surface of the cathode electrode 4, they merge with each other and stay as droplets 20. To introduce the same oxygen-containing gas over the entire surface of the cathode electrode 4, when the distance from the center of the cathode electrode 4 is r, the interval between the holes 19 is proportional to r-1 from the center toward the periphery. It is better to reduce it. However, if the level of the cathode electrode 4 with respect to the water surface, the density of the water droplets 32, and the velocity component are not defined, the stagnation of the oxygen-containing gas occurs with the fusion of the water droplets 32 in the cathode electrode 4.
By supplying water droplets containing oxygen-containing gas only from the side of the inclined cathode electrode 4 close to the water surface, the water droplets that have reached the cathode electrode 4 can flow in a certain direction. As a result, since water droplets do not stay on the surface of the cathode electrode 4, it is possible to prevent the water droplets from fusing and forming large droplets.
Since the operation of the electrolysis cell 1 that generates hydrogen peroxide is the same as that of the first to third embodiments, the description thereof is omitted.

  As described above, according to the hydrogen peroxide production apparatus of the fourth embodiment, a sufficient amount of oxygen is supplied and diffused to the cathode electrode by supplying the oxygen-containing gas and water to the cathode electrode simultaneously and uniformly without stagnation. Highly uniform hydrogen ion conductivity can be obtained over the entire surface of the ion conductive film, the contact probability between oxygen and hydrogen ions at the cathode electrode is increased, and the hydrogen peroxide generation efficiency is increased. An effect can be obtained.

Example 4
The effect of inclining the electrolysis cell 1 with respect to the water surface of the water 23 in the hydrogen peroxide recovery tank 22 using the hydrogen peroxide production apparatus of the fourth embodiment will be described.
As conditions for generating hydrogen peroxide, the applied voltage is 2.0 to 2.2 V, the temperature is 25 ° C., and the areas of the anode electrode 3 and the cathode electrode 4 are 19 cm ² . Since the material which comprises the electrolytic cell 1 is the same as Example 1, description is abbreviate | omitted.
The distance from the water surface of point A to L1 [mm] as the location closest to the water surface of the cathode electrode 4 (referred to as point A) and the farthest location (referred to as point B), and the length of the cathode electrode 4 in the tilt direction Is defined as L2 [mm]. Assuming that the generation rate of hydrogen peroxide when the angle θ = 0 degree is 1 under the conditions of L2 = 40 [mm] and L1 = 2 [mm], it is 2.0 at θ = 2 degrees, and at θ = 5 degrees. It was 0.7 at 1.5 and θ = 10 degrees. Further, θ was 0.5 when θ = 20 °, and 0.3 when θ = 30 °.
Therefore, if the inclination angle of the electrolysis cell 1 with respect to the water surface is θ [degree], the range of θ is preferably about 0.1 to 20 degrees. In order to further improve the amount of hydrogen peroxide produced, the distance from the water surface is set to 0 to 20 mm at the location closest to the water surface of the cathode electrode 4 (referred to as point A) and the farthest location (referred to as point B). It is desirable to install within the range. For example, when the distance from the water surface at point A is L1 [mm] and the length of the cathode electrode 4 in the tilt direction is L2 [mm], the angle θ is determined as in the following formula (5).
L1 <L2 × tan θ + L1 <20 (5)

  Thus, according to Example 4, by supplying oxygen-containing gas and water simultaneously and uniformly to the cathode electrode without stagnation, a sufficient amount of oxygen is supplied and diffused to the cathode electrode, and on the entire surface of the ion conductive film. Uniformly high hydrogen ion conductivity can be obtained, the contact probability between oxygen and hydrogen ions at the cathode electrode is increased, and a remarkable effect such as that of the conventional hydrogen peroxide generation efficiency can be obtained. Moreover, the weight ratio of oxygen / water can be controlled in the range of 100/1 to 1 / 5,000 by controlling the distance L1 from the water surface to the cathode electrode 4 to 0 to 20 mm.

Embodiment 5 FIG.
FIG. 10 is a schematic cross-sectional view showing a hydrogen peroxide production apparatus according to Embodiment 5 of the present invention. FIG. 11 is a diagram illustrating a configuration of a header portion of the hydrogen peroxide production apparatus according to the fifth embodiment. 11A is a top view of the header portion, FIG. 11B is a cross-sectional view taken along the line AA of FIG. 11A, FIG. 11C is a cross-sectional view taken along the line BB of FIG. CC sectional drawing, (e) is a header side view, (f) is DD sectional drawing of (e), (g) is EE sectional drawing of (b).

  In the fifth embodiment, a droplet 20 is formed on the surface of the cathode electrode 4 using a header 33 instead of the gas supply pipe 18 in the third embodiment. The header 33 has a gas supply port 37 and a gas suction port 38, which are alternately arranged in a straight line as shown in FIGS. Inside the header 33, meandering channels 39 and 40 connected to the gas supply port 37 and the gas suction port 38 are formed, respectively, as shown in (g) and (f). The oxygen-containing gas supplied from the oxygen-containing gas supply device 17 is introduced into the gas supply port 37 through the gas supply pipe 34, and the bubbles 31 of the oxygen-containing gas are released from the gas supply port 37. Bubbles 31 emerging from the water surface come into contact with the cathode electrode 4 as water droplets 32 containing an oxygen-containing gas and form droplets 20 on the surface of the cathode electrode 4. On the other hand, a pump 36 is connected to the header 33 as suction means, and excess bubbles 31 on the surface of the cathode electrode 4 are sucked together with water through the gas suction port 38 and removed. The removed water and the bubbling oxygen-containing gas are returned to the water tank 23 through the return pipe 41. Since it is necessary to supply water together with oxygen to the cathode electrode, the header 33 needs to exist below the surface of the water. In order to set the weight ratio of oxygen / water to a range of 100/1 to 1/1000, the header What is necessary is just to set the distance h of the upper surface of 33 and the water surface to 10 mm-0.1 mm. In addition, since the configuration of the apparatus, the material configuration of the electrolysis cell, the operation method of the electrolysis cell, and the like are the same as those in Embodiment 1, they are omitted.

  When water droplets 32 containing an oxygen-containing gas reach the surface of the cathode electrode 4, they fuse together and stay. By using the header 33 of the fifth embodiment, the water droplet 32 can be sufficiently brought into contact with the cathode electrode 4, and at the same time, it can be sucked and removed before the excessive bubbles 31 are fused. As a result, since excessive water droplets do not stay on the surface of the cathode electrode 4, oxygen-containing gas and water can be supplied to the cathode electrode simultaneously and uniformly without stagnation, and hydrogen peroxide can be generated efficiently. . In addition to the shape shown in FIG. 11, the header 33 can be used as a header as long as the gas supply port 37 is surrounded by one or a plurality of gas suction ports 38.

  As described above, according to the hydrogen peroxide production apparatus of the fifth embodiment, by removing excessive water droplets and bubbles, the oxygen-containing gas and water are simultaneously and uniformly supplied to the cathode electrode without stagnation. A sufficient amount of oxygen to be supplied and diffused, and a high hydrogen ion conductivity can be obtained uniformly over the entire surface of the ion conductive film, and the probability of contact between oxygen and hydrogen ions at the cathode is increased. It is possible to obtain a notable effect such as an increase in generation efficiency.

Example 5
The effect of sucking and removing excess bubbles using the header 33 according to the fifth embodiment using the hydrogen peroxide production apparatus of the fifth embodiment will be described.
As conditions for generating hydrogen peroxide, the applied voltage is 2.0 to 2.2 V, the temperature is 25 ° C., and the areas of the anode electrode 3 and the cathode electrode 4 are 19 cm ² . In Example 5, an oxygen gas having a concentration of 100% was used as the oxygen-containing gas, and the flow rate was set to 50 cc / min. The distance h between the water surface and the header was set to 1 mm. Since the material which comprises the electrolytic cell 1 is the same as that of Example 1, description is abbreviate | omitted.
Assuming that the maximum hydrogen peroxide generation rate when the pump 36 is not operated is 1, the generation rate is 1.2 at a gas suction flow rate of 10 cc / min of the pump 36, 1.5, 50 cc / min at 20 cc / min. Thus, it was 1.5 at 2.0 and 75 cc / min, and 1.0 at 100 cc / min. From this, it became clear that the generation efficiency of hydrogen peroxide can be improved by sucking and removing excess bubbles.
As a result of detailed examination even when the flow rate of oxygen gas is other than 50 cc / min, the relationship between the supply gas flow rate Q1 of the oxygen-containing gas supply device and the suction flow rate Q2 of the pump 36 is expressed by the following equation (6).
0.1 × Q1 <Q2 <2 × Q1 (6)
Should be satisfied.
Here, if the distance h between the water surface and the header is 10 mm to 0.1 mm, the weight ratio of oxygen / water can be set in a range of 100/1 to 1/1000. However, when an oxygen-containing gas whose oxygen concentration is not 100% is used, it may be considered in terms of the amount of oxygen.

Embodiment 6 FIG.
FIG. 12 is a schematic cross-sectional view showing a hydrogen peroxide production apparatus according to Embodiment 6 of the present invention.
As shown in FIG. 12, the electrolytic cell 1 is installed on the hydrogen peroxide recovery tank 22, and the water surface of the water 23 in the hydrogen peroxide recovery tank 22 and the cathode electrode 4 are spaced apart. The oxygen-containing gas supply means includes an oxygen-containing gas supply device 17 and a gas supply pipe 18 connected to the oxygen-containing gas supply device. The gas supply pipe 18 discharges oxygen-containing gas to the water surface of the water 23 to provide a cathode. This is supplied to the electrode 4. The water supply means is constituted by a peristaltic body 42 installed in the hydrogen peroxide recovery tank 22, and supplies water to the cathode electrode 4 by moving the peristaltic body 42 left and right. The same reference numerals as those in FIG. 1 denote the same or corresponding parts, and the description thereof will be omitted.

In the sixth embodiment, the water is supplied by causing the water 23 in the hydrogen peroxide recovery tank 22 to generate a wave on the water surface by the oscillating body 42 that is a rocking device and causing the wave front 43 to contact the surface of the cathode electrode 4 intermittently. By doing. The oxygen-containing gas is supplied by introducing the oxygen-containing gas generated from the oxygen-containing gas supply device 17 into the periphery of the cathode electrode 4 from the gas supply pipe 18 and when the wave front 43 is separated from the cathode electrode 4. Supplied. In addition, since the configuration of the apparatus, the material configuration of the electrolysis cell, the operation method of the electrolysis cell, and the like are the same as those in Embodiment 1, they are omitted.
As the swinging means, as described above, a plate-like moving body is installed vertically in the water, and the moving body is moved to the left and right. A plate-like moving body is installed in parallel on the water surface, and the moving body. One that strikes the surface of the water and one that vibrates the water surface using an ultrasonic element can be considered. Water is supplied to the cathode electrode 4 by the oscillating means and oxygen-containing gas is supplied from the oxygen gas-containing gas supply device 17 to the cathode electrode 4 to supply necessary water and oxygen to the cathode electrode 4. Can be generated.

  Thus, according to the hydrogen peroxide production apparatus of the sixth embodiment, a sufficient amount of oxygen is supplied to the cathode electrode by simultaneously supplying the oxygen-containing gas and water to the cathode electrode by the peristaltic means and the oxygen-containing gas supply apparatus. And hydrogen can be uniformly diffused over the entire surface of the ion conductive film, the probability of contact between oxygen and hydrogen ions at the cathode electrode is increased, and the generation efficiency of hydrogen peroxide is increased. The remarkable effect which is not in the past can be acquired.

Example 6
Using the hydrogen peroxide production apparatus of the sixth embodiment, the hydrogen peroxide production characteristics using some peristaltic means according to the sixth embodiment will be described.
As conditions for generating hydrogen peroxide, the applied voltage is 2.0 to 2.2 V, the temperature is 25 ° C., and the areas of the anode electrode 3 and the cathode electrode 4 are 19 cm ² . Since the material which comprises the electrolytic cell 1 is the same as Example 1, description is abbreviate | omitted.
When the distance between the cathode electrode 4 and the water surface is set to 5 mm and the maximum hydrogen peroxide generation rate in the state where the swinging means is stopped is 1, the plate-like swinging body 42 installed vertically in the water is When moved to the left and right at a cycle of about 0.1 to 10 Hz, the hydrogen peroxide production rate increased in the range of 5 to 50. When the plate-shaped peristaltic body placed parallel to the water surface was beaten with a period of 0.1 to 10 Hz, the hydrogen peroxide production rate increased in the range of 5 to 40. In addition, when the water surface was vibrated using an ultrasonic element in the range of 100 to 10 MHz, the hydrogen peroxide generation rate increased in the range of 2 to 100. Furthermore, even if the distance from the cathode electrode 4 to the water surface is changed in the range of 1 to 50 mm, it is confirmed that there is an effect (compared to the case of stopping) that increases the hydrogen peroxide generation rate by the oscillator 42. It was done.
Thus, it was confirmed that the weight ratio of oxygen / water can be set in the range of 100/1 to 1 / 3,000 when the swinging means is used and the distance from the water surface to the cathode electrode 4 is 5 mm. .

FIG. 13 is a schematic cross-sectional view showing a hydrogen peroxide production apparatus according to Embodiment 7 of the present invention.
As shown in FIG. 13, the electrolysis cell 1 is installed on the hydrogen peroxide recovery tank 22, and the water surface of the water 23 in the hydrogen peroxide recovery tank 22 and the cathode electrode 4 are spaced apart. The oxygen-containing gas supply means includes an oxygen-containing gas supply device 17 and a gas supply pipe 18 connected to the oxygen-containing gas supply device. The gas supply pipe 18 discharges oxygen-containing gas to the water surface of the water 23 to provide a cathode. This is supplied to the electrode 4. The water supply means is constituted by a rotating motor 44 which is a peristaltic means installed in the electrolytic cell 7, and supplies water to the cathode electrode 4 by rotating the electrolytic cell 7. The same reference numerals as those in FIG. 1 denote the same or corresponding parts, and the description thereof will be omitted.

  In the seventh embodiment, the water is supplied by rotating the electrolytic cell 7 with the rotating motor 44 which is a peristaltic means of the water 23 in the hydrogen peroxide recovery tank 22, thereby generating the wave front 43 of the wave generated on the water surface as the cathode electrode. 4. Perform by intermittent contact with the surface. The oxygen-containing gas is supplied by introducing the oxygen-containing gas generated from the oxygen-containing gas supply device 17 to the periphery of the cathode electrode 4 from the gas supply pipe 18, and when the wave front 43 is separated from the cathode electrode 4. Supply. In addition, since the configuration of the apparatus, the material configuration of the electrolysis cell, the operation method of the electrolysis cell, and the like are the same as those in Embodiment 1, they are omitted.

  Thus, according to the hydrogen peroxide production apparatus of the seventh embodiment, a sufficient amount for the cathode electrode is obtained by simultaneously supplying the oxygen-containing gas and water to the cathode electrode by the electrolytic cell rotating means and the oxygen-containing gas supply apparatus. The oxygen ion can be supplied and diffused, and high hydrogen ion conductivity can be obtained uniformly over the entire surface of the ion conductive film, the contact probability of oxygen and hydrogen ions at the cathode electrode is increased, and the production efficiency of hydrogen peroxide is increased. It is possible to obtain a remarkable effect that has not been achieved so far.

  In the description of the embodiment of the present invention, the case where a perfluorosulfonic acid membrane is used as the polymer electrolyte membrane 2 has been described. However, the polymer electrolyte membrane 2 does not transmit gas, has electrical insulation, and has only moisture and hydrogen ions. In addition, polybenzimidazole ion exchange membranes, polybenzoxazole ion exchange membranes, polyarylene ether ion exchange membranes, and the like can be used. Further, when phosphoric acid molecules having about 2 to 6 times the number of water molecules contained in the polymer electrolyte membrane 2 are added, the hydrogen ion conductivity is increased and the generation efficiency of hydrogen peroxide is improved.

  In addition to the carbon fiber described in the embodiment, the cathode electrode material may be a carbon nanofiber (thickness: 10 to 100 nm), graphite or graphite with an alkali metal inserted between layers, single layer or multilayer. Carbon nanotubes (thickness of 10 nm or less), fibrous activated carbon or particulate activated carbon may be used.

  Further, the material of the electrolytic cell 7 and the fixing flange 9 may be other than an insulating material, and carbon or stainless steel (SUS316, SUS304, etc.) may be used to increase mechanical strength. Further, the electrolytic cell 7 and the fixing flange 9 itself may be energized as an integral member of the anode terminal 5 and the cathode terminal 6. Moreover, in order to suppress corrosion, the surface of the electrolytic cell 7 and the fixing flange 9 may be subjected to platinum (Pt) plating or titanium (Ti) plating with a thickness of about 0.01 to 4 μm.

Embodiment 8 FIG.
FIG. 14 is a schematic cross-sectional view showing an example in which the hydrogen peroxide production apparatus according to Embodiment 4 of the present invention is installed in an air conditioner having a cooling / heating function. Water vapor in the air is cooled on the surface of the heat exchanger 45 and condensed on the surface of the heat exchanger 45 to become condensed water 46 (the condensed water is hereinafter referred to as “drain water”). Since the surface of the heat exchanger 45 has been subjected to a hydrophilic treatment, when a certain amount or more of the condensed water 46 adheres, the heat exchanger 45 starts to fall spontaneously and is collected in the drain pan 48 as drain water 47. Next, the drain water 47 is supplied to the cathode electrode of the hydrogen peroxide production apparatus 50 at a constant speed by the water supply means 49, and further, the air sent by the blower fan (not shown) is supplied to the cathode electrode. . The generated hydrogen peroxide 52 is sprayed on the surface of the heat exchanger 45 by the hydrogen peroxide supply means 51 to remove mold, bacteria, and the like generated and attached to the surface of the heat exchanger 45.

  As the water supply means 49 and the hydrogen peroxide supply means 51, power such as a liquid feed pump, capillary action of a fibrous water absorbent sheet, ultrasonic spraying, or the like can be used. As the water-absorbing sheet, a sheet made of pulp and polyethylene fiber, a ceramic fiber, or a glass fiber can be used. In particular, when the hydrogen peroxide 52 is supplied to the heat exchanger 45, it is preferable to use ceramic fibers or glass fibers having low reactivity with hydrogen peroxide. In addition, there is an advantage that it is not necessary to supply water from the outside by using condensed water obtained by condensing water vapor in the air as water to be supplied to the hydrogen peroxide production apparatus, but drain water is not necessarily used. Newly supplied water may be used.

  Thus, according to the air conditioner in which the hydrogen peroxide production apparatus of the present invention is installed, the heat exchanger is washed with hydrogen peroxide produced by the hydrogen peroxide production apparatus, and is generated on the surface of the heat exchanger. It has the effect of suppressing the generation of mold and bacteria.

Example 7
FIG. 15 shows the sterilization effect on the cells attached to the heat exchanger by the air conditioner in which the hydrogen peroxide producing apparatus according to Embodiment 8 of the present invention is installed, as the measurement result of Example 7. The test was conducted under the following setting conditions. As conditions for producing hydrogen peroxide, in Embodiment 2, the current value is 0.5 to 5 A, the temperature is 25 ° C., the flow rate of air supplied as the oxygen-containing gas is 20 to 100 cc / min, the anode electrode 3 and the cathode electrode 4 The area is 19 cm ² , and the gap length d between the cathode electrode 4 and the water surface is 5 mm. The material constituting the electrolytic cell 1 was the same as in Example 1.

Water vapor in the air is cooled on the surface of the heat exchanger 45 and condensed on the surface of the heat exchanger 45 to form condensed water 46. Since the surface of the heat exchanger 45 has been subjected to a hydrophilic treatment, if a condensed water 46 of 0.1 mg / cm ² or more per unit area adheres, it starts to fall naturally and is collected in the drain pan 48. Next, the drain water 47 of the drain pan 48 is supplied to the cathode electrode of the hydrogen peroxide production apparatus 50 at a constant speed by the water supply means 49. Further, the air sent by the blower fan (not shown) is supplied to the cathode electrode. Supplied. The generated hydrogen peroxide 52 is dispersed on the surface of the heat exchanger 45 by the hydrogen peroxide supply means 51. In advance, 900 E. coli cells per cm ² were allowed to live on the surface of the heat exchanger 45, and the number of E. coli cells was measured when the hydrogen peroxide solution generated by the hydrogen peroxide production apparatus 50 was sprayed. As the water supply means 49, composite paper having a width of 40 mm and a length of 30 cm made of an inorganic oxide mainly composed of glass fibers having a thickness of 0.25 mm to 3 mm and a wire diameter of 0.1 μm to 100 μm was used. An ultrasonic spray device was used as the hydrogen peroxide supply means 51. The spray rate was set to 250 cc / hr, and the spray particle size was set to 3 μm.

Next, a change in the number of cells on the surface of the heat exchanger when the generated hydrogen peroxide 52 is sprayed on the heat exchanger 45 will be described in detail. In FIG. 15, the time change of the number of cells when the current value is set to 0.5 A is indicated by a solid line A, and the time change of the number of cells when the current value is set to 5 A is indicated by a one-dot chain line B. For comparison, the time change of the bacterial cells when the power is turned off and the current value is set to 0 A in this embodiment is indicated by a broken line C as a comparative example. In A and B, the number of E. coli cells decreased with time as the power was turned on, and the rate of decrease increased in proportion to the current value. This is probably because the hydrogen peroxide concentration increased in proportion to the current value. The amounts of hydrogen peroxide produced in A and B were 120 ppm and 800 ppm, respectively. On the other hand, since no hydrogen peroxide was produced in the comparative example, the number of cells was constant at approximately 800 to 900 cells / cm ² .

  Thus, the effect of suppressing the generation of mold and bacteria generated on the surface of the heat exchanger in the air conditioner by washing the heat exchanger with hydrogen peroxide produced by the hydrogen peroxide production apparatus of the present invention It was confirmed that there is.

Embodiment 9 FIG.
FIG. 16 is a schematic cross-sectional view showing an example in which the hydrogen peroxide production apparatus according to Embodiment 9 of the present invention is installed in an air cleaner used for business purposes. As shown in FIG. 16, a blower 53 for circulating air, a cooling coil 54 for adjusting temperature and humidity, a heating coil 55, and a sterilization element 56 for forming a water film for bringing hydrogen peroxide into contact with air are installed inside the apparatus. Thus, an air cleaner 62 is configured.
Further, a hydrogen peroxide production apparatus 50 is provided as a means for supplying hydrogen peroxide to the sterilization element 56, and the generated hydrogen peroxide is removed from the watering header 59 via the pump 57 and the flow rate adjustment valve 58. It is configured to be supplied to the fungus element 56. Then, the air 60 to be sterilized is sucked into the air purifier 62 from the sterilization element 56 installation side (left side in FIG. 16). A pad is disposed at the center of the sterilizing element 56 forming a water film, and a dispersion mat (not shown) is attached to the upper surface thereof. The dispersion mat is configured to be supplied with hydrogen peroxide through a watering header 59 connected to a flow rate adjusting valve 58. Further, a drain pan 48 is disposed below the pad so that drain water 47 containing hydrogen peroxide flowing down the pad can be discharged to the outside of the apparatus.

  The hydrogen peroxide generated by the hydrogen peroxide production apparatus 50 is sucked up by the pump 57 and is sprayed to the dispersion mat of the sterilization element 56 by the water spray header 59 through the flow rate control valve 58. On the other hand, the air 60 is taken into the main body of the air purifier 62 by the blower 53, mold and bacteria are removed by the sterilization element 56, cooled by the cooling coil 54, dehumidified, and then heated by the heating coil 55 to be cleaned. The converted air is taken out from the air cleaner 62.

  If a water-absorbing material with high water retention is used as a pad of the sterilization element 56 that forms a water film, not only can the amount of hydrogen peroxide dripped be reduced, but also contact with air to be sterilized. Since the time can be extended, the sterilization performance can be improved. As the material of the pad, for example, composite ceramics fired using glass fiber as an aggregate or porous ceramics can be used. Moreover, you may use the water absorbing material using chemical fibers, such as polyester and polyethylene.

  Moreover, drain water may be used as the water supplied to the hydrogen peroxide producing apparatus, and the water supplied from the outside can be reduced.

  Thus, by installing the hydrogen peroxide production apparatus according to the present invention in an air cleaner used for business use, hydrogen peroxide can be efficiently generated, and the sterilization element is present in the air by hydrogen peroxide. Effective in removing mold and bacteria.

Embodiment 10 FIG.
FIG. 17: is a schematic sectional drawing which shows the example which installed the hydrogen peroxide manufacturing apparatus in Embodiment 10 of this invention in the humidifier. As shown in FIG. 17, the humidifier includes a water storage tank 63 that stores water for humidifying air, a drain pan 48 that collects water from the humidifying element 64, and a pipe 67 that sends drain water 47 from the drain pan 48 to the water storage tank 63. The pipe 68 is connected to the water storage tank 63 and the humidifying element 64.

  Water for humidification is supplied from the water storage tank 63 to the cathode electrode of the hydrogen peroxide production apparatus 50 at a constant speed by the water supply means 49, and further sent to the cathode electrode by a blower fan (not shown). Air is supplied. Hydrogen peroxide 65 generated by the hydrogen peroxide production apparatus 50 is sprayed on the humidifying element 64 by the hydrogen peroxide supply means 51. The hydrogen peroxide 65 cleans the surface of the humidifying element 64 and removes molds and bacteria generated on the surface. The hydrogen peroxide 66 used for cleaning is recovered by a drain pan 48. The drain water 47 of the drain pan 48 is sent to the water storage tank 63 through the pipe 67. The pipe 68 is for supplying water from the water storage tank 63 to the humidifying element 64.

  As the water supply means 49 and the hydrogen peroxide supply means 51, power such as a liquid feed pump, capillary action of a fibrous water absorbent sheet, ultrasonic spraying, or the like can be used. As the water-absorbing sheet, a sheet made of pulp and polyethylene fiber, a ceramic fiber, or a glass fiber can be used. In particular, when the hydrogen peroxide 65 is delivered to the humidifying element 64, it is preferable to use ceramic fiber or glass fiber that has low reactivity with hydrogen peroxide. In addition, there is an advantage that it is not necessary to supply water from the outside by using a part of the water for humidification as the water supplied to the hydrogen peroxide production apparatus, but the water for humidification is not necessarily used. Separately supplied water may be used.

  As described above, the portion where moisture easily accumulates in the humidifier, particularly the humidifying element, the drain pan, etc., has a problem that mold is likely to be generated. By generating hydrogen peroxide by the apparatus and washing the humidifying element, there is an effect of suppressing the generation of mold and bacteria. In addition, even if the place where hydrogen peroxide is supplied is dried, hydrogen peroxide has a vapor pressure of about 1/10 that of water and is difficult to evaporate. The sterilization effect of bacteria is dramatically improved.

1 is a schematic cross-sectional view showing a hydrogen peroxide production apparatus in Embodiment 1. FIG. 2 is a schematic cross-sectional view showing a configuration of an electrolysis cell part of the hydrogen peroxide production apparatus according to Embodiment 1. It is a figure which shows the measurement result of the elapsed time by Example 1 using the hydrogen peroxide manufacturing apparatus in Embodiment 1, and a droplet average diameter. It is a figure which shows the measurement result of the droplet diameter by the Example 1 using the hydrogen peroxide manufacturing apparatus in Embodiment 1, and the production rate of hydrogen peroxide. 5 is a schematic cross-sectional view showing a hydrogen peroxide production apparatus in Embodiment 2. FIG. FIG. 6 is a schematic cross-sectional view showing a hydrogen peroxide production apparatus according to Embodiment 3. It is a figure which shows the measurement result of the production rate of hydrogen peroxide with respect to the gap length by Example 2 using the hydrogen peroxide manufacturing apparatus in Embodiment 3. It is a figure which shows the measurement result of the production | generation rate of the hydrogen peroxide with respect to the presence or absence of the additive by Example 3 using the hydrogen peroxide manufacturing apparatus in Embodiment 3. FIG. FIG. 6 is a schematic cross-sectional view showing a hydrogen peroxide production apparatus in a fourth embodiment. FIG. 10 is a schematic cross-sectional view showing a hydrogen peroxide production apparatus in a fifth embodiment. FIG. 10 is a schematic diagram showing a header part of a hydrogen peroxide production apparatus according to Embodiment 5. FIG. 10 is a schematic cross-sectional view showing a hydrogen peroxide production apparatus in a sixth embodiment. FIG. 10 is a schematic cross-sectional view showing a hydrogen peroxide production apparatus in a seventh embodiment. It is a schematic sectional drawing which shows the example which installed the hydrogen peroxide manufacturing apparatus in Embodiment 8 in the air conditioner. It is a figure which shows the measurement result by Example 7 of the microbe elimination effect with respect to the microbial cell attached to the heat exchanger of the air conditioner which installed the hydrogen peroxide manufacturing apparatus in Embodiment 8. It is a schematic sectional drawing which shows the example which installed the hydrogen peroxide manufacturing apparatus in Embodiment 9 in the air cleaner used for a business use. It is a schematic sectional drawing which shows the example which installed the hydrogen peroxide manufacturing apparatus in Embodiment 10 in the humidifier.

DESCRIPTION OF SYMBOLS 1 Electrolysis cell 2 Polymer electrolyte membrane 3 Anode electrode 4 Cathode electrode 7 Electrolysis tank 13 Ultrasonic generator 15 Water supply pipe 17 Oxygen-containing gas supply apparatus 18, 34 Gas supply pipe 22 Hydrogen peroxide recovery tank 24 Power supply 33 Header 35 Gas Suction pipe 36 Pump 42 Peristaltic body 44 Rotating motor 45 Heat exchanger 50 Hydrogen peroxide production device 56 Disinfection element 64 Humidification element

Claims (10)

An electrolyte membrane having hydrogen ion conductivity;
An anode electrode disposed in contact with the first surface of the electrolyte membrane;
A cathode electrode disposed in contact with the second surface of the electrolyte membrane;
An electrolysis cell comprising:
A power source for applying a DC voltage to the anode electrode and the cathode electrode;
An electrolytic cell in which the electrolytic cell constitutes a part of the bottom surface and stores water;
A hydrogen peroxide recovery tank installed below the cathode electrode;
Bubbling means for generating bubbles by being immersed in water in the hydrogen peroxide recovery tank;
Gas supply means for supplying an oxygen-containing gas to the bubbling means;
With
An apparatus for producing hydrogen peroxide, wherein droplets are formed on the surface of the cathode electrode by water droplets generated by the bubbles. 2. The hydrogen peroxide production apparatus according to claim 1, wherein the bubbling means is a gas supply pipe having a plurality of holes having a diameter of 0.1 to 2 mm or a header connected to the gas supply pipe. The bubbling means has a suction port for sucking a part of bubbles in water,
The hydrogen peroxide production apparatus according to claim 2, wherein the amount of the bubbles is controlled. The hydrogen peroxide production apparatus according to any one of claims 1 to 3, wherein the cathode electrode includes carbon fiber subjected to water repellent treatment. A hydrogen peroxide production apparatus according to any one of claims 1 to 4,
An air conditioner having a function of cleaning a heat exchanger using hydrogen peroxide produced by the hydrogen peroxide production apparatus. The air conditioner according to claim 5, further comprising means for supplying drain water to the cathode electrode of the hydrogen peroxide production apparatus. A hydrogen peroxide production apparatus according to any one of claims 1 to 4,
An air cleaner having a function of sterilizing air using hydrogen peroxide produced by the production of the hydrogen peroxide production apparatus. The air cleaner of Claim 7 which supplies the produced | generated hydrogen peroxide to the said disinfection element from the watering header installed above the disinfection element. A hydrogen peroxide production apparatus according to any one of claims 1 to 4,
A humidifier having a function of cleaning a humidifying element using hydrogen peroxide produced by the hydrogen peroxide production apparatus. The humidifier according to claim 9, further comprising means for supplying drain water to the cathode electrode of the hydrogen peroxide production apparatus.

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