JP4844321B2 - Hydrogen peroxide production apparatus and air conditioner, air purifier and humidifier using the same - Google Patents

Description

  The present invention relates to an apparatus for electrochemically producing hydrogen peroxide from, for example, 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 part of at least 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. ing. 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.
Moreover, in the hydrogen peroxide production apparatus according to the invention of Patent Document 2, there is one in which a gas permeable electrode material layer is formed on one side of a hydrophilic porous layer and an ion exchange membrane is formed in close contact with the other side. Since the electrolytic product is discharged through the hydrophilic porous layer, oxygen gas can be smoothly supplied to the electrode where hydrogen peroxide is generated. Thereby, hydrogen peroxide can be produced efficiently.

JP 2005-146344 A Japanese Patent No. 3625633

  However, in the conventional hydrogen peroxide production apparatus, when hydrogen peroxide is generated using water and an oxygen-containing gas, water on the cathode inhibits oxygen diffusion, so that sufficient hydrogen peroxide is generated. There was a problem that characteristics could not be obtained.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a hydrogen peroxide production apparatus capable of efficiently generating hydrogen peroxide using water and an oxygen-containing gas.

  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 a second electrolyte membrane. An electrolysis cell comprising a cathode electrode disposed in contact with the surface of the electrode, means for supplying water to the anode electrode, gas-liquid switching means for alternately supplying oxygen-containing gas and water to the cathode electrode, and anode And a power source for applying a DC voltage between the electrode and the cathode electrode.

  According to the present invention, by supplying oxygen-containing gas and water intermittently, it becomes possible to supply and diffuse a sufficient amount of oxygen to the cathode electrode, and hydrogen peroxide can be efficiently generated.

  The structure of claim 6 is an air conditioner having a function of cleaning the heat exchanger using hydrogen peroxide manufactured in the hydrogen peroxide manufacturing apparatus.

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

  The configuration of claim 8 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, since the switching means for alternately supplying oxygen and water to the cathode is provided, the contact probability between oxygen and hydrogen ions at the cathode is increased, and the hydrogen peroxide generation efficiency is increased. There is an effect.

Hereinafter, an apparatus for producing hydrogen peroxide according to an embodiment of the present invention 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 shows a schematic cross-sectional view of the electrolytic cell portion.
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. Further, the anode electrode 3 has an anode terminal 5, and the cathode electrode 4 has a cathode terminal 6. The polymer electrolyte membrane 2, the anode electrode 3 and the cathode electrode 4 are fixed and sealed by an O-ring 8 and are accommodated in flanges 7a and 7b. The anode side flange 7a of the electrolysis cell 1 is provided with an anode water supply port 9 and an anode discharge port 10, the cathode side flange 7b is provided with a cathode inlet port 11 and a hydrogen peroxide solution outlet port 12. An oxygen-containing gas supply port 14 and a cathode water supply port 15 are provided through a gas-liquid switch 13 as a liquid switching unit, respectively, and the electrolytic cell 1 has a DC power supply 16 through an anode terminal 5 and a cathode terminal 6. Is connected.

  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 17 and polymer electrolyte particles 18 are mixed is formed on the surface of the carbon fiber 4a that is 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 flanges 7a and 7b are made of an insulating material such as an acrylic resin, and the electrolytic cell 1 is fastened by the anode terminal 5 and the cathode terminal 6 at a surface pressure of 0.2 × 10 ⁴ to 1 × 10 ⁴ Pa.
The anode side flange 7 a is provided with a recess for taking water into the anode electrode 3. The flange 7b on the cathode side is provided with a recess for taking water and gas into the cathode electrode 4 in the same manner as the flange 7a.

  The anode terminal 5 and the cathode terminal 6 are obtained by welding a thin rod (outer diameter 2 mm, length 15 mm) to a circular flat plate (radius 1 cm, thickness 2 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. The distance d between the flange 7b and the cathode electrode 4 may be in the range of 0.05 mm to 50 mm.

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.
An electrochemical reaction is caused in the electrolytic cell 1 while a DC voltage is applied continuously or intermittently between the anode terminal 5 and the cathode terminal 6 by the DC power source 16. First, water supplied from the anode water supply port 9 of the flange 7 a passes through the anode electrode 3 and comes into contact with the polymer electrolyte membrane 2. Then, the water is absorbed by the polymer electrolyte membrane 2, diffuses in the polymer electrolyte membrane 2, and the water is retained 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 voltage is applied by the DC power supply 16, a current flows and oxygen is generated from the surface of the anode electrode 3.
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 ⁺ ), for example, a perfluorosulfonic acid membrane. When a gas containing oxygen (O ₂ ) such as air and water (H ₂ O) are supplied from the oxygen-containing gas supply port 14 and the cathode water supply port 15 connected to the polymer electrolyte membrane 2, The hydrogen ions (H ⁺ ) conducted from the anode electrode 3 that reached the interface of the gas, and the reducing substance caused by the hydrogen ions (H ⁺ ) and oxygen gas (O ₂ ) react to produce a reduction represented by the reaction formula (2). Hydrogen peroxide (H ₂ O ₂ ) is generated by the reaction. The aqueous solution containing hydrogen peroxide is taken out from the hydrogen peroxide outlet 12.
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 .
Cathode: O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O ₂ (2)
Further, in the cathode electrode 4, the reaction formula (3) in which oxygen (O ₂ ) is further reduced to produce water (H ₂ O) and the hydrogen ions (H ⁺ ) are directly reduced, and hydrogen (H ₂ ) is converted. The generated 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 17 and the electrolyte particles 18 adjacent to the polymer electrolyte membrane 2, the electrolyte particles 18 are three-dimensionally joined, and hydrogen ions (H ⁺ ) generated on the anode side are polymer electrolyte. Transmits through the membrane 2. Then, oxygen (O ₂ ) supplied from the cathode side receives electrons at the interface 19 (part indicated by a black dot) between the carbon particles 17 and the electrolyte particles 18 to generate hydrogen peroxide (H ₂ O ₂ ). The 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 1/10000, and as a result, the reaction formula (2) hardly proceeds.
In addition, even when neutral water is used, the reaction formulas (3) and (4) are likely to proceed, which may cause a decrease in the generation efficiency of hydrogen peroxide.

  The present inventors have found that the supply rate of oxygen to the cathode electrode 4 can be dramatically increased by supplying oxygen and water to the electrolysis cell 1 instead of simultaneously supplying them alternately. Thereby, the production | generation efficiency of hydrogen peroxide can be improved. In addition, as a property of the electrode, it has been confirmed that the water-repellent material can improve the contact between oxygen and hydrogen ions than the hydrophilic material. In the past, it was thought that products could be generated efficiently if hydrophilic materials were used, but in reality, the surface of a hydrophilic material is easily covered with water, and the polymer electrolyte is a site where hydrogen peroxide is generated. Since the interface 19 of the three different phases of the membrane 2, the cathode electrode 4 and the air phase is covered with water, the efficiency is lowered.

As a water supply method, an inert gas such as nitrogen is blown into warm water and moisture is blown to the electrode, and water is refined into water droplets having a diameter of about several μm using ultrasonic (1 kHz to 2 MHz) vibration. Method of entraining mist-like water droplets with active gas, forced cooling by moisture (air) present in the atmosphere with an aluminum (Al) plate whose surface is controlled at 5-30 ° C by continuously circulating an electronic cooler or refrigerant Then, there are a method of dropping condensed water and a method of directly supplying liquid water. The water supply amount and supply method are determined in accordance with the required hydrogen peroxide production amount.
If the water supplied to the anode side contains cations due to metal ions such as calcium (Ca), magnesium (Mg), potassium (K), etc., the hydrogen ions inside the polymer electrolyte membrane 2 will become cations. Therefore, it is preferable to use ion-exchanged water or ultrapure water both when supplying liquid water directly and when supplying fine water. 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 electrical conductivity is 5 μScm ⁻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, loss due to heat can be suppressed by applying energy only to hydrogen ions by applying a pulsed voltage. 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.

  Next, the gas-liquid switching means, which is the main feature of the present invention, will be described in detail. The gas-liquid switch 13 serving as the gas-liquid switching means can alternately flow the oxygen-containing gas and water, and the gas-liquid supply time ratio between the supply of the oxygen-containing gas and the supply of water (= gas supply time / water supply). Time) can be controlled. If the supply amount of the oxygen-containing gas and water is controlled, a mixed fluid of oxygen gas and water in any ratio can be formed on the surface of the cathode electrode 4. As the gas-liquid switch 13, for example, a manifold valve, a diaphragm seal valve, a bellows seal valve, a ball valve, or the like can be used. The gas-liquid supply time ratio of the oxygen-containing gas and water may be in the range of 0.1 to 50, and more desirably, the effect can be obtained by setting to 2 to 25. One cycle of the supply time of the oxygen-containing gas and water can be expected to be effective if it is in the range of 1 sec to 1 hour. Since the gas-liquid supply time ratio depends on the amount of water supplied to the cathode, the optimum value within the above range is determined by the gas flow rate, the water flow rate, and the water repellency of the cathode electrode 4. This is because the hydrogen peroxide production capacity depends on the amount of oxygen in the supplied oxygen-containing gas and the amount of water, but the contact time of oxygen gas and water with the electrode does not depend on the flow rate, only the respective supply times. Because it depends on.

  The gas-liquid switch 13 does not simply supply water or an oxygen-containing gas between the cathode electrode 4 and the flange 7b. The gas-liquid switch 13 controls the movement speed of water and oxygen per unit area and unit area passing through the cathode electrode 4. There is a function to control. For example, the moving velocity of water and oxygen to the surface of the cathode electrode 4 is increased by increasing the linear flow velocity of the fluid to be introduced or imparting physical energy to the fluid. The gas-liquid supply time ratio of oxygen-containing gas and water and one cycle time are not necessarily constant, and may be changed during operation.

In the first embodiment, the case where a perfluorosulfonic acid membrane is used as the polymer electrolyte membrane 2 has been described. However, any material that does not transmit gas, has electrical insulation, and conducts only moisture and hydrogen ions can be used. In addition, a polybenzimidazole-based ion exchange membrane, a polybenzoxazole-based ion exchange membrane, a polyarylene ether-based ion exchange membrane, or the like can also be used. At this time, the number of water molecules contained in the polymer electrolyte membrane 2 can be used. When about 2 to 6 times as many phosphoric acid molecules are added, hydrogen ion conductivity is increased and the production efficiency of hydrogen peroxide can be improved.
In addition to carbon fibers, carbon nanofibers (thickness 10 to 100 nm), graphite or graphite with an alkali metal inserted between layers, single-walled or multi-walled carbon nanotubes (thickness 10 nm or less) ), Fibrous activated carbon or particulate activated carbon can be used.

  The flanges 7a and 7b may be made of carbon or stainless steel (SUS316, SUS304, etc.) in order to increase mechanical strength. Alternatively, the flanges 7a and 7b may be made of a conductive material, and the flanges 7a and 7b themselves may be used as an integral member with the anode terminal 5 and the cathode terminal 6 for energization. Furthermore, in order to suppress corrosion, platinum (Pt) plating or titanium (Ti) plating with a thickness of about 0.01 to 4 μm may be performed on the surfaces of the flanges 7a and 7b.

  Thus, according to the hydrogen peroxide production apparatus of the first embodiment, since it has switching means for alternately introducing oxygen and water to the cathode, the cathode electrode surface is not covered with water, It is possible to increase the probability of contact with hydrogen ions, and to obtain a remarkable effect that has not been achieved so far, such as improved production efficiency of hydrogen peroxide.

[Example 1]
The measurement results of the hydrogen peroxide generation characteristics according to Example 1 using the hydrogen peroxide production apparatus according to Embodiment 1 will be described. The whole hydrogen peroxide production apparatus shown in FIG. 1 was used, and the electrolytic cell shown in FIG. 2 was used.
As the material constituting the electrolytic cell 1, the base material of the anode electrode 4 is titanium expanded metal (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 conditions for hydrogen peroxide generation, the applied voltage is 2.0 to 2.2 V, the temperature is 25 ° C., the supplied oxygen gas flow rate is 10 to 50 cc / min, the area of the anode electrode 3 and the cathode electrode 4 is 19 cm ² , flange The distance d between 7b and the cathode electrode 4 is 3 mm. The gas-liquid supply time ratio by the gas-liquid switch 13 was set to 4, and one cycle of the oxygen-containing gas and water supply time was set to 15 min. The anode electrode 3 was supplied with room temperature ion-exchanged water at a rate of 5 cc / hr, assuming that water was recovered from the air by cooling. Further, a 100 cc glass beaker (not shown) was installed in the vicinity of the cathode electrode 4, 10 cc of ion-exchanged water at room temperature was introduced, and the cathode electrode 4 was introduced at a rate of 50 cc / hr. The hydrogen peroxide solution discharged from the cathode was returned to the glass beaker, and water was circulated between the glass beaker and the cathode electrode 4. That is, the hydrogen peroxide generated on the surface of the cathode electrode 4 gradually accumulates in the water circulating between the glass beaker and the cathode electrode 4. The change with time in the hydrogen peroxide concentration was measured by attaching an ultraviolet absorptiometer (not shown) to a part of a glass beaker.

FIG. 4 shows the change over time in the hydrogen peroxide concentration in Example 1 with a solid line A. For comparison, a case where the gas-liquid switch 13 is removed in FIG. 1 and only water saturated with oxygen gas (without oxygen gas) is supplied is shown as Comparative Example 1-1 in FIG. Further, a case where oxygen gas and water are simultaneously supplied and introduced at an oxygen gas flow rate of 10 cc / min and a water flow rate of 50 cc / hr is indicated by a broken line C as Comparative Example 1-2.
In Example 1, the hydrogen peroxide concentration increased in proportion to the time with the direct current power ON, and reached a maximum of 1600 mg / L after 1600 min. This is because the water once supplied is instantaneously removed by oxygen, so that the probability of contact of oxygen and hydrogen ions with the cathode increases, and the production efficiency of hydrogen peroxide is maintained. In Comparative Example 1-1, the amount of hydrogen peroxide generated was very small and remained at about 50 mg / L even after 1600 minutes. In Comparative Example 1-2, the hydrogen peroxide concentration increased in proportion to the time, but remained at about 200 mg / L even after about 1600 min after about 3 to 4 times that of Comparative Example 1. This is because in Comparative Example 1-1, the entire surface of the cathode electrode 4 is covered with water, and in Comparative Example 1-2, a part of the cathode electrode 4 is covered with water, so that the supply rate of oxygen to the electrode surface is significantly reduced. it is conceivable that.

[Example 2]
The measurement result of the hydrogen peroxide generation characteristic according to Example 2 in which the gas-liquid supply time ratio is changed using the hydrogen peroxide production apparatus of the first embodiment will be described. As conditions for hydrogen peroxide generation, the applied voltage is 2.0 to 2.2 V, the temperature is 25 ° C., the area of the anode electrode 3 and the cathode electrode 4 is 19 cm ² , and the distance d between the flange 7 b and the cathode electrode 4 is 3 mm. is there. Since the material constituting the electrolytic cell 1 is the same as that of the first embodiment, the description thereof is omitted. FIG. 5 shows the amount of hydrogen peroxide generated when the gas-liquid switch 13 is adjusted to change the gas-liquid supply time ratio between the oxygen-containing gas and water between 0.1 and 180. The results are shown.
In Examples 2-1, 2-2, and 2-3, the oxygen gas flow rates were 30 cc / min, 10 cc / min, and 50 cc / min, respectively, and the water flow rates were 50 cc / hr, 25 cc / hr, and 100 cc / hr, respectively. Supplied with. One cycle of supply time of oxygen-containing gas and water was set to 15 min. There is an optimum condition for the gas-liquid supply time ratio regardless of the setting conditions of the flow rates of oxygen gas and water. As a result, it was clarified that the effect can be expected if the hydrogen peroxide generation rate is 0.2 mg / min or more, and the gas-liquid supply time ratio is between 0.1 and 50. Desirably, if the gas-liquid supply time ratio is set to 2 to 25, the hydrogen peroxide generation rate can be expected to be 0.8 mg / min. If the gas introduction time ratio is longer than 45, the amount of water that volatilizes with the introduction of the gas increases and the ionic conductivity of the electrolyte membrane 2 is lost. As a result, the hydrogen supplied to the cathode electrode 4 It is thought that the contact probability between ions and oxygen decreased, and the rate of hydrogen peroxide generation decreased. On the other hand, when the gas-liquid supply time ratio is shorter than 0.5, it is considered that a part of the cathode electrode 4 is covered with water, so that the oxygen supply rate to the electrode surface is remarkably reduced. .

  Thus, according to Examples 1 and 2 of the hydrogen peroxide production apparatus of the first embodiment, since the gas-liquid switching means for alternately supplying the oxygen-containing gas and water to the cathode electrode is provided, the oxygen with respect to the cathode electrode And the hydrogen ion contact probability is improved, and the hydrogen peroxide generation efficiency is improved. In addition, the gas-liquid supply time ratio between gas and water is preferably maintained between 2 and 25.

Embodiment 2. FIG.
FIG. 6 is a schematic cross-sectional view showing the configuration of the electrolysis cell of the hydrogen peroxide production apparatus according to Embodiment 2 of the present invention. Next, the structure of the electrolytic cell 1 in Embodiment 2 is demonstrated. The cathode electrode 4 is an electrode sheet 4c made of carbon fiber having a fiber diameter of about 2 to 100 μm and a porosity of 50 to 80% as a carbon-based material, and a water repellent treatment layer attached to one surface of the electrode sheet 4c. It is composed of three layers of a casting film 4d (15 to 30 μm thick) and a support 4f attached to the other surface of the electrode sheet 4c. The casting film 4d is obtained by dispersing a mixed liquid composed of PTFE dispersion composed of polytetrafluoroethylene particles (PTFE: Polytetrafluoroethylene) having a particle diameter of 0.1 to 50 μm and graphite powder, and then drying to form a sheet. Preferably, it is desirable to use graphite fluoride obtained by pulverizing and atomizing graphite and then performing fluorine gas treatment. The electrode sheet 4c and the casting film 4d, and the electrode sheet 4c and the support 4f are joined together by thermocompression bonding.

  Here, the support 4f is required to have sufficient gas permeability in addition to conductivity. When a support having insufficient gas permeability is used, hydrogen is generated according to the reaction formula (4). Therefore, a graphite fiber cloth that has been subjected to water repellent treatment with a PTFE dispersion in advance is used as the support 4f. The cathode electrode 4 is attached to the polymer electrolyte membrane 2 so that the surface of the casting film 4d is in contact therewith. In the gas permeable cathode electrode 4 produced in this way, hydrogen generation by the reaction formula (4) did not occur even under an electric field having a relatively high current density. The above thermocompression bonding process was performed using a hot press under conditions of 150 to 300 ° C. and a pressure bonding time of 1 to 5 minutes. The material and configuration of the anode electrode 3 are the same as those of the electrolytic cell 1 in FIG.

  As described above, since a casting film having water repellency is used as the reduction catalyst layer for the cathode electrode, there is an effect that hydrogen peroxide can be generated continuously without the cathode electrode being covered with water. .

Example 3
FIG. 7 shows the measurement results of the hydrogen peroxide generation characteristics in Example 3 of the hydrogen peroxide production apparatus using the electrolytic cell of Embodiment 2 shown in FIG. The generation conditions are as follows: the applied voltage is 2.0 to 2.2 V, the temperature is 25 ° C., the flow rate of the introduced oxygen gas is 10 to 50 cc / min, the area of the anode electrode 3 and the cathode electrode 4 is 19 cm ² , the flange 7b and the cathode The distance d between the electrodes 4 is 3 mm. The oxygen gas flow rate was set to 30 cc / min, the water flow rate was set to 50 cc / hr, and the gas / liquid supply time ratio was set to 5 using the gas / liquid switch 13. In addition, assuming that water is recovered from the air by cooling, the ion exchange water at room temperature was supplied to the anode electrode 3 at a rate of 5 cc / hr. The concentration of hydrogen peroxide contained in the hydrogen peroxide solution taken out from the cathode electrode 4 was measured with an ultraviolet absorptiometer (not shown). In FIG. 7, the result of having compared the time change of the hydrogen peroxide concentration by the difference in the carbon-type base material of the electrode sheet 4c is shown. The electrode sheet 4c was activated carbon in Example 3A (dashed line A in FIG. 7), carbon black in Example 3B (solid line B in FIG. 7), stabilized carbon black in Example 3C (chain line C in FIG. 7), and Example 3D (in FIG. 7). 7 dash-dotted line D) contains 70 to 90% of graphite.

  Here, activated carbon is mostly carbonaceous charcoal with high adsorptivity, and carbon black is fine carbon obtained by a combination of pyrolysis and incomplete combustion of hydrocarbons such as natural gas and petroleum. Stabilized carbon black is a powder with a hexagonal structure that is stabilized by heat treatment, etc. Graphite (also called graphite) is a carbon-based mineral that is stable at normal pressure. Yes, it has hexagonal hexagonal flat crystals and is classified according to the hexagonal structure ratio (graphitization degree) and orientation. In addition to the above, graphite, carbon black, and stabilized carbon black have the following characteristics. Focusing on two peaks in the Raman spectrum of each material, near 1340 cm −1 (D-band) and 1600 cm −1 (G-band), when natural graphite is 1, the graphite used this time is 0.6 to 1.2, Stabilized carbon black is 0.2 to 0.6, and carbon black is 0.2 or less.

Next, the generation characteristics of hydrogen peroxide due to differences in carbon-based materials will be described.
As shown in FIG. 7, when the material of the electrode sheet 4c was activated carbon (Example 3A (broken line A in FIG. 7)), the production efficiency immediately after the start of the reaction was low, and it rapidly decreased with the progress of the electrochemical reaction. Carbon black (Example 3B (FIG. 7 solid line B)) had a relatively high production efficiency immediately after the start of the reaction, but thereafter showed a tendency to gradually decrease. On the other hand, the graphite-based material (Example 3D (FIG. 7, one-dot chain line D)) shows the highest efficiency immediately after the start of the reaction, and then shows a tendency to gradually decrease, but generally maintains a relatively high efficiency. Yes. Activated carbon (Example 3A (FIG. 7 broken line A)) accelerates the reaction of the reaction formula (2) and also serves as a catalyst for the decomposition reaction of hydrogen peroxide, which is caused by the presence of oxygen-containing functional groups on the carbon surface. It is said that. In the experiment, the generation efficiency of activated carbon is low, and it is considered that this is because of the rapid decrease with time. Further, the generation efficiency of chemically stabilized graphitized carbon black (Example 3C (FIG. 7 chain line C)) is lower than that of carbon black because the surface is oxidized, and there are many oxygen-containing functional groups on the surface. It seems to be the result of being affected. Therefore, as a material of the electrode sheet 4c, it was confirmed that among the carbon-based materials, those using graphite were excellent in hydrogen peroxide generation ability.
From these facts, by using a combination of a casting film 4d having water repellency composed of PTFE particles and ultrafine powdered graphite fluoride as the cathode electrode 4, and an electrode sheet made of graphite in particular, oxygen and hydrogen Since the contact probability of ions increases, hydrogen peroxide can be generated efficiently.

Example 4
FIG. 8 shows the measurement results of the hydrogen peroxide generation characteristics in Example 4 of the hydrogen peroxide production apparatus using the electrolytic cell of Embodiment 2 shown in FIG. FIG. 8 shows the change over time of the hydrogen peroxide production concentration depending on whether or not the electrode sheet 4c is treated with fluorine. The carbon-based material of the electrode sheet 4c used here is stabilized carbon black and graphite. The generation conditions are as follows: the applied voltage is 2.0 to 2.2 V, the temperature is 25 ° C., the flow rate of the introduced oxygen gas is 10 to 50 cc / min, the area of the anode electrode 3 and the cathode electrode 4 is 19 cm ² , the flange 7b and the cathode The distance d between the electrodes 4 is 3 mm. The oxygen gas flow rate was set to 30 cc / min, the water flow rate was set to 50 cc / hr, and the gas / liquid supply time ratio was set to 5 using the gas / liquid switch 13. In addition, assuming that water is recovered from the air by cooling, the ion exchange water at room temperature was supplied to the anode electrode 3 at a rate of 5 cc / hr. The concentration of hydrogen peroxide contained in the hydrogen peroxide solution taken out from the cathode electrode 4 was measured with an ultraviolet absorptiometer (not shown).

In order to avoid the influence of heating and contamination in the production process of the electrode sheet 4c, the fluorine gas treatment was performed after the casting film 4d and the support 4f were bonded to the electrode sheet 4c and the cathode electrode 4 was produced. In order to replace the surface functional group with a C—F bond, the fluorine gas treatment was performed at room temperature and an F ₂ partial pressure of 50 Torr.
When the carbon-based material of the electrode sheet 4c is graphite, it is apparent after the fluorine treatment (Example 4D-2 (FIG. 8, one-dot chain line D)) compared to before the fluorine treatment (Example 4D (FIG. 8, chain line C)). It was found that the hydrogen peroxide generation efficiency was improved and the functional group substitution treatment was effective. However, the production efficiency was lowered by repeating the electrochemical reaction, and the initial surface treatment effect was not seen. As a result of measuring and evaluating a strip sample obtained by subjecting the same electrode sheet to fluorine treatment under the same conditions with an ESCA (X-ray photo-electron spectrometer), the disappearance of the surface treatment effect is caused by repeated electrochemical reactions. This is probably because the C—F bond on the surface was broken and disappeared. Further, the effect of the fluorine treatment was also evaluated on the chemically stabilized stabilized carbon black, but after the fluorine treatment (Example 4C-2) as compared to before the fluorine treatment (Example 4C (dashed line in FIG. 8)). (FIG. 8, solid line B)) clearly shows that the generation efficiency is improved and the functional group substitution treatment is effective. The reason why the generation efficiency of graphite is high is considered that the surface functional groups of graphite exist mainly on the crystal end face, and there are relatively few surface functional groups relative to the entire surface, and this is the F ₂ surface treatment. This is also considered to be the reason for the small effect.

  From these results, it is clear that the surface functional group is deeply related to the generation efficiency. By treating the carbon-based material of the electrode sheet with fluorine, the water repellency can be improved and the generation efficiency of hydrogen peroxide is improved. be able to.

Example 5
FIG. 9 shows the measurement results of the hydrogen peroxide generation characteristics in Example 5 of the hydrogen peroxide production apparatus using the electrolytic cell of Embodiment 1 shown in FIG. 2 and Embodiment 2 shown in FIG. FIG. 9 shows the change over time in the hydrogen peroxide production concentration due to the difference in the structure of the electrolytic cell. Example 5-1 uses the electrolytic cell of the second embodiment, and graphite is used as the carbon-based material of the electrode sheet 4c to perform the fluorine treatment. Example 5-2 uses the electrolytic cell of the first embodiment. For comparison, the hydrogen peroxide generation characteristics in the case where the electrolytic cell of Embodiment 1 was not used and the carbon fiber was not subjected to water repellency treatment by fluorine treatment were also evaluated as Comparative Example 5. The generation conditions are as follows: the applied voltage is 2.0 to 2.2 V, the temperature is 25 ° C., the supplied oxygen gas flow rate is 10 to 50 cc / min, the area of the anode electrode 3 and the cathode electrode 4 is 19 cm ² , the flange 7 b and the cathode The distance d between the electrodes 4 is 3 mm. The oxygen gas flow rate was set to 30 cc / min, the water flow rate was set to 50 cc / hr, and the gas / liquid supply time ratio was set to 5 by the gas / liquid switch 13. In addition, assuming that water is recovered from the air by cooling to the anode 3, normal temperature ion exchange water was supplied at a rate of 5 cc / hr. The concentration of hydrogen peroxide contained in the hydrogen peroxide solution taken out from the cathode electrode 4 was measured with an ultraviolet absorptiometer (not shown).

Compared with Comparative Example 5 (FIG. 9, chain line C), Example 5-2 (FIG. 9, solid line B) obtained a high hydrogen peroxide concentration from the beginning. This is because in Example 5-2, the carbon powder of the carbon fiber 4a as the carrier is water repellent, so that the water repellency is increased and the surface of the cathode electrode 4 is not covered with water. This is because the oxygen supply rate does not decrease.
In contrast, Example 5-1 (FIG. 9, one-dot chain line A) has the same initial characteristics as Example 5-2 (FIG. 9, solid line B), but the hydrogen peroxide concentration decreases with time. High performance could be maintained for a long time. This is presumably because high water repellency could be maintained for a long time by making the cathode electrode 4 into a three-layer structure of the electrode sheet 4c, the casting film 4b, and the support 4f as shown in FIG. And, by subjecting each of the electrode sheet 4c and the support 4f to water repellency, the surface reaction group was oxidized and altered by the electrochemical reaction proceeding on the cathode surface and the generated hydrogen peroxide, and the surface substituent did not change. This is because the supply of oxygen to the cathode is promoted, and the contact probability of oxygen and hydrogen ions to the cathode increases.

  Thus, the surface of the carbon-based material carried on the cathode electrode is replaced with fluorine or mixed with a water-repellent material, or the electrode is made of a multi-layer structure of an electrode sheet containing a carbon material and a support, and each is made of fluorine By performing the water repellency treatment by the above, it is possible to obtain an unprecedented remarkable effect that the contact probability between oxygen and hydrogen ions at the cathode is increased and the hydrogen peroxide generation characteristics are improved.

Embodiment 3 FIG.
FIG. 10 is a schematic cross-sectional view showing an example in which the hydrogen peroxide production apparatus according to Embodiment 3 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 20 and condensed on the surface of the heat exchanger 20 to become condensed water 21 (condensed water is hereinafter referred to as “drain water”). Since the surface of the heat exchanger 20 has been subjected to a hydrophilic treatment, when a certain amount of condensed water 21 or more adheres, the heat exchanger 20 starts to fall spontaneously and is collected in the drain pan 22 as drain water 23. Next, the drain water 23 is supplied to the anode electrode of the hydrogen peroxide production apparatus 25 at a constant speed by the water supply means 24, and the air sent by the blower fan (not shown) is supplied to the cathode electrode. The generated hydrogen peroxide solution is sprayed on the surface of the heat exchanger 20 by the hydrogen peroxide solution supply means 26 to remove mold, bacteria, and the like generated and attached to the surface of the heat exchanger 20.

  As the water supply unit 24 and the hydrogen peroxide solution supply unit 26, 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 hydrogen peroxide is supplied to the heat exchanger 20, it is preferable to use ceramic fiber or glass fiber having low reactivity with hydrogen peroxide.

  Thus, according to the air conditioner in which the hydrogen peroxide production apparatus of the present invention is installed, it can be used even in an environment where water necessary for the production of hydrogen peroxide cannot be secured, and the diluted water present in the air It is possible to produce hydrogen peroxide using heat, and heat exchange with hydrogen peroxide produced by hydrogen peroxide production equipment using water condensed by a heat exchanger inside the air conditioner By washing the vessel, it is possible to suppress the generation of mold and bacteria that are generated on the surface of the heat exchanger.

Example 6
FIG. 11 shows the measurement results of Example 6 on the sterilization effect on the cells attached to the heat exchanger by the air conditioner in which the hydrogen peroxide production apparatus according to Embodiment 3 of the present invention is installed. The test was conducted under the following setting conditions. As conditions for producing hydrogen peroxide, in Embodiment 1, the current value is 0.5 to 5 A, the temperature is 25 ° C., the supplied air flow rate is 20 to 100 cc / min, and the area of the anode electrode 3 and the cathode electrode 4 is 19 cm ^2. The distance d between the flange 7b and the cathode electrode 4 is 3 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 20, condensed on the surface of the heat exchanger 20, and becomes condensed water 21. Since the surface of the heat exchanger 20 has been subjected to a hydrophilic treatment, if condensed water 21 of 0.1 mg / cm ² or more per unit area adheres, it begins to fall spontaneously and is collected in the drain pan 22. Next, the drain water 23 of the drain pan 22 is supplied to the anode electrode of the hydrogen peroxide production device 25 at a constant speed by the water supply means 24, and the air sent by the blower fan (not shown) is supplied to the cathode electrode. The The generated hydrogen peroxide solution is sprayed on the surface of the heat exchanger 20 by the hydrogen peroxide solution supply means 26. In advance, 900 E. coli cells per 1 cm ² were allowed to live on the surface of the heat exchanger 20, and the number of E. coli cells when the hydrogen peroxide solution generated by the hydrogen peroxide production apparatus 25 was sprayed was measured. As the water supply means 24, 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 (Honda Electronics Co., Ltd., HM-303N) was used as the hydrogen peroxide solution supply means 26. The spray rate was set to 250 cc / hr, and the spray particle size was set to 3 μm.

Next, changes in the number of cells on the surface of the heat exchanger when the generated hydrogen peroxide is sprayed on the heat exchanger 20 will be described in detail. FIG. 11 shows the time change of the number of cells when the current value is set to 0.5 A as a solid line A as Example 6-1 and the time change of the number of cells when the current value is set to 5 A. This is indicated by a dashed line B as Example 6-2. For comparison, in FIG. 11, the time change of the bacterial cells when the DC power source is turned off and the current value is set to 0 A is shown as a comparative example 6 in FIG. In Examples 6-1 and 6-2, the number of Escherichia coli cells decreased with time as the DC power was turned on, and the rate of decrease increased in proportion to the current value. This is considered because the hydrogen peroxide concentration increased in proportion to the current value. The production amounts of hydrogen peroxide in Example 6-1 and Example 6-2 were 120 ppm and 800 ppm, respectively. On the other hand, in Comparative Example 6, since hydrogen peroxide was not generated, the number of cells was constant at approximately 800 to 900 cells / cm ² .

  Thus, even in an air conditioner that is used in an environment where water necessary for the production of hydrogen peroxide cannot be secured, it is produced by the hydrogen peroxide production apparatus of the present invention using water condensed by a heat exchanger. It was confirmed that washing the heat exchanger with hydrogen peroxide water has the effect of suppressing the generation of mold and bacteria on the surface of the heat exchanger inside the air conditioner.

Embodiment 4 FIG.
FIG. 12 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 cleaner used for business purposes. As shown in FIG. 12, a blower 27 that circulates air, a cooling coil 28 that adjusts temperature and humidity, a heating coil 29, and a sterilization element 30 that forms a water film that brings hydrogen peroxide into contact with air are installed inside the apparatus. Thus, the air purifier 36 is configured.
Further, a hydrogen peroxide water production apparatus 28 is provided as means for supplying hydrogen peroxide solution to the sterilization element 30, and the generated hydrogen peroxide solution is supplied to the watering header via the pump 31 and the flow rate adjustment valve 32. 33 is configured to be supplied to the sterilization element 30. Then, the air 34 to be sterilized is sucked into the air purifier 36 from the sterilization element 30 installation side (left side in FIG. 11). A pad is disposed at the center of the sterilizing element 30 that forms 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 solution through a watering header 33 connected to a flow rate adjusting valve 32. Further, a drain pan 22 is disposed under the sterilization element 30 so that the hydrogen peroxide solution flowing down the pad can be discharged to the outside of the apparatus.

  The hydrogen peroxide solution generated by the hydrogen peroxide production device 28 is sucked up by the pump 31 and is sprayed to the dispersion mat of the sterilization element 30 by the water spray header 33 through the flow rate control valve 32. On the other hand, the air 34 is taken into the main body of the air cleaner 36 by the blower 27, mold and bacteria are removed by the sterilizing element 30, cooled by the cooling coil 28, dehumidified, and then heated by the heating coil 29 to be cleaned. The converted air 35 is taken out from the air purifier 36.

  If a water-absorbing material with high water retention is used as a pad of the sterilization element 30 that forms a water film, not only can the amount of hydrogen peroxide water dripped be reduced, but also the air to be sterilized. Since the contact time can be increased, 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.

  In this way, by installing the hydrogen peroxide production apparatus according to the present invention in an air cleaner used for business use, hydrogen peroxide is efficiently generated, and mold and bacteria present in the air are removed by the sterilization element. There is an effect that can be removed.

Embodiment 5 FIG.
FIG. 13: is a schematic sectional drawing which shows the example which installed the hydrogen peroxide manufacturing apparatus in Embodiment 5 of this invention in the humidifier. As shown in FIG. 13, the humidifier includes a water storage tank 37 that stores water for humidifying air, a drain pan 22 that collects water from the humidifying element 38, and a pipe 40 that sends drain water 23 from the drain pan 22 to the water storage tank 37. The pipe 41 is connected to the water storage tank 37 and the humidifying element 38.

Water for humidification is supplied from the water storage tank 37 to the anode electrode of the hydrogen peroxide production device 25 by the water supply means 24 at a constant speed, and the air sent by a blower fan (not shown) is supplied to the cathode electrode. Supplied. The hydrogen peroxide solution generated by the hydrogen peroxide production device 25 is sprayed to the humidifying element 38 by the hydrogen peroxide solution supply means 26. The hydrogen peroxide solution 39 cleans the surface of the humidifying element 38 and removes mold, bacteria, etc. generated on the surface. The hydrogen peroxide solution 39 used for cleaning is collected by the drain pan 22. The drain water 23 in the drain pan 22 is sent to the water storage tank 37 through the pipe 40. The pipe 41 is for supplying water from the water storage tank 37 to the humidifying element 38.
As the water supply means 24 and the hydrogen peroxide supply means 26, 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 hydrogen peroxide is delivered to the humidifying element 38, it is preferable to use ceramic fiber or glass fiber having low reactivity with hydrogen peroxide.

  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 of the hydrogen peroxide production apparatus according to Embodiment 1. FIG. 3 is an explanatory diagram of hydrogen peroxide generation in Embodiment 1. FIG. The hydrogen peroxide production | generation characteristic by the gas-liquid switching using the hydrogen peroxide manufacturing apparatus in Embodiment 1 is shown. The hydrogen peroxide production | generation characteristic by the gas-liquid supply time using the hydrogen peroxide manufacturing apparatus in Embodiment 1 is shown. 6 is a schematic cross-sectional view showing a configuration of an electrolysis cell of a hydrogen peroxide production apparatus according to Embodiment 2. FIG. The hydrogen peroxide production | generation characteristic by the difference in the electrolytic cell material of the hydrogen peroxide manufacturing apparatus in Embodiment 2 is shown. The hydrogen peroxide production | generation characteristic by the presence or absence of the fluorine treatment of the electrolytic cell of the hydrogen peroxide manufacturing apparatus in Embodiment 2 is shown. It is a comparison figure of the hydrogen peroxide production | generation characteristic by the hydrogen peroxide manufacturing apparatus in Embodiment 1 and Embodiment 2. FIG. It is a schematic sectional drawing which shows the example which installed the hydrogen peroxide manufacturing apparatus in Embodiment 3 in the air cleaner. The result of the disinfection effect with respect to the microbial cell adhering to the heat exchanger of the air cleaner which installed the hydrogen peroxide manufacturing apparatus in Embodiment 3 is shown. It is a schematic sectional drawing which shows the example which installed the hydrogen peroxide manufacturing apparatus in Embodiment 4 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 5 in the humidifier.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrolysis cell 2 Polymer electrolyte membrane 3 Anode electrode 4 Cathode electrode 9 Anode water supply port 12 Hydrogen peroxide water outlet 13 Gas-liquid switch 14 Oxygen-containing gas supply port 15 Cathode water supply port 16 DC power supply 20 Heat exchanger 25, 28 Hydrogen peroxide production equipment 30 Disinfection element
38 Humidifier

Claims (9)

An electrolytic cell comprising an electrolyte membrane having hydrogen ion conductivity, an anode electrode disposed in contact with the first surface of the electrolyte membrane, and a cathode electrode disposed in contact with the second surface of the electrolyte membrane; ,
Means for supplying water to the anode electrode;
Gas-liquid switching means for alternately supplying oxygen-containing gas and water to the cathode electrode;
A power source for applying a DC voltage between the anode electrode and the cathode electrode;
An apparatus for producing hydrogen peroxide, comprising:   The hydrogen peroxide according to claim 1, wherein the cathode electrode has a reduction catalyst layer composed of carbon particles and electrolyte particles on a carbon-based substrate, and the reduction catalyst layer is in contact with the electrolyte membrane. Manufacturing equipment.   The cathode electrode is made of an electrode sheet made of a carbon-based material, and a casting film made of a dispersed layer of PTFE particles and graphite powder is bonded to one surface of the electrode sheet, and the PTFE particles are adhered to the opposite surface of the electrode sheet. 2. The hydrogen peroxide production apparatus according to claim 1, wherein the support made of graphite fiber cloth is joined to form a casting film, and the casting film is in contact with the electrolyte membrane.   The hydrogen peroxide production apparatus according to claim 3, wherein graphite is used as the carbon-based material.   5. The hydrogen peroxide production apparatus according to claim 3, wherein the cathode electrode is treated with fluorine gas.   6. The hydrogen peroxide production apparatus according to claim 1, wherein the gas-liquid supply time ratio of the oxygen-containing gas and water is 2 to 25.   An air conditioner for cleaning a heat exchanger using hydrogen peroxide produced in the hydrogen peroxide production apparatus according to any one of claims 1 to 6.   An air cleaner, wherein air is sterilized using hydrogen peroxide produced in the hydrogen peroxide production apparatus according to any one of claims 1 to 6.   A humidifier for cleaning a humidifying element using hydrogen peroxide produced in the hydrogen peroxide production apparatus according to any one of claims 1 to 6.

Images