Hydrogen peroxide generator

Abstract

To provide a hydrogen peroxide generator that can efficiently generate hydrogen peroxide.SOLUTION: A hydrogen peroxide generator comprises: a water bath unit 11 for storing water 16; a pair of electrode units 12F and 12S arranged in the water 16; a power supply unit 13 for applying a pulse-shaped voltage with the maximum voltage of 1 kV or more to the pair of electrode units 12F and 12S; and an insulation unit 14, which is arranged between the pair of electrode units 12F and 12S, for dividing the water bath unit 11 into one side of the electrode unit 12F and the other side of the electrode unit 12S. The insulation unit 14 is an electrical insulator in which multiple holes 18 are formed to penetrate from the one side of the electrode unit 12F through the other side of the electrode unit 12S.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a hydrogen peroxide generating device. [Background technology]

[0002] Hydrogen peroxide, a compound with the chemical formula H2O2, is used in ordinary households as a disinfectant and bleach due to its oxidizing power. The current method for producing hydrogen peroxide is primarily the autoxidation method using alkylanthraquinones, as described in Non-Patent Document 1. However, hydrogen peroxide is produced through multiple processes, including oxidation, extraction, and cleaning, using various chemicals. For household use, hydrogen peroxide is purchased in liquid form in a bottled container from a dedicated manufacturing plant and dispensed in small amounts as needed. However, because hydrogen peroxide gradually decomposes over time, if hydrogen peroxide is stored for a long period of time, it may already have decomposed by the time it is needed, leaving no usable hydrogen peroxide. Therefore, there is a need for a technology to generate hydrogen peroxide at home for ordinary households.

[0003] Meanwhile, for example, Patent Document 1 below describes a liquid treatment device in which an insulating partition wall with through-holes is provided between plate electrodes in a treatment tank. This technology discloses that when a treatment liquid containing pollutants is introduced into the treatment tank of this liquid treatment device and a voltage is applied between the plate electrodes, an electric field is concentrated in the through-holes, generating plasma to treat the pollutants. This technology discloses that ultraviolet rays, radicals, and shock waves are generated by the plasma to decompose pollutants such as organic matter, but does not disclose that hydrogen peroxide is generated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-93972 [Non-patent literature]

[0005] [Non-Patent Document 1] Ryo Kusakabe, "Production, Properties, and Handling of Hydrogen Peroxide," Journal of the Japan Paper and Pulp Technology Association, Vol. 52, No. 5, 1998, pp. 608-615 Summary of the Invention [Problem to be solved by the invention]

[0006] In order to produce a highly concentrated hydrogen peroxide solution, a hydrogen peroxide generator capable of efficiently producing hydrogen peroxide was desired.

[0007] The present disclosure was completed in light of the above circumstances, and an object of the present disclosure is to provide a hydrogen peroxide generating device that can efficiently generate hydrogen peroxide. [Means for solving the problem]

[0008] The hydrogen peroxide generating device disclosed herein comprises a water tank for storing water, a pair of electrodes disposed across the water, a power supply for applying a pulsed voltage of 1 kV or more to the pair of electrodes, and an insulating section disposed between the pair of electrodes and separating the water tank into one electrode side and the other electrode side, the insulating section being an electrical insulator with a plurality of holes formed therein that extend from the one electrode side to the other electrode side. The inventors discovered that when this device is filled with potable, contaminant-free tap water and a predetermined pulsed voltage is applied, plasma is generated in the holes provided in the insulator, and hydrogen peroxide (HO) is generated by the plasma from water (HO), leading to the invention. [Brief explanation of the drawings]

[0009] [Figure 1] Schematic diagram showing the configuration of a hydrogen peroxide generating device [Figure 2] Front view showing the insulating part [Figure 3] Front view showing the cover [Figure 4] A diagram showing the output voltage waveform of the power supply unit [Figure 5] Table showing the results of Experiment 1 [Figure 6]Table showing the results of Experiment 2 DETAILED DESCRIPTION OF THE INVENTION

[0010] <Embodiment> As shown in Fig. 1, the hydrogen peroxide generator (hereinafter simply referred to as device 10) includes a water tank unit 11, a pair of electrode units 12F, 12S, a power supply unit 13, an insulating unit 14, and a pair of cover units 15F, 15S. Device 10 applies a voltage between the pair of electrode units 12F, 12S to generate plasma in water 16 and generate hydrogen peroxide. Device 10 may be used independently or may be incorporated into plumbing equipment such as a toilet, bathroom, kitchen, or sink.

[0011] In each drawing, the X axis is parallel to the opposing direction of the pair of electrode portions 12F, 12S, the Y axis extends vertically along the opposing surfaces 17F, 17S of the pair of electrode portions 12F, 12S, and the Z axis is perpendicular to the X axis and Y axis and extends horizontally along the opposing surfaces 17F, 17S.

[0012] The water tank 11 is made of resin and contains water 16, a pair of electrodes 12F, 12S, an insulating part 14, and a pair of covers 15F, 15S. The water 16 is tap water or the like that is readily available at home.

[0013] The pair of electrode units 12F, 12S are arranged with water 16 therebetween. Of the pair of electrode units 12F, 12S, the first electrode unit 12F is an anode and the other, the second electrode unit 12S, is a cathode. The first electrode unit 12F and the second electrode unit 12S are both flat plate-shaped and arranged opposite each other.

[0014] A first opposing surface 17F of the first electrode portion 12F and a second opposing surface 17S of the second electrode portion 12S face the insulating portion 14. The first opposing surface 17F and the second opposing surface 17S are flat surfaces extending in the vertical Y direction and the horizontal X direction. The first opposing surface 17F and the second opposing surface 17S are parallel to each other, and the distance between the first opposing surface 17F and the second opposing surface 17S is equal everywhere.

[0015] The power supply unit 13 is electrically connected to the pair of electrodes 12F, 12S. The power supply unit 13 applies a pulsed voltage with a maximum voltage of 1 kV or more to the pair of electrodes 12F, 12S. The power supply unit 13 is a pulse power supply or the like that instantaneously outputs a high voltage and a large current.

[0016] The insulating portion 14 is formed of an electrical insulator that is electrically insulating. The insulating portion 14 is flat. The insulating portion 14 is disposed between the pair of electrodes 12F and 12S. The insulating portion 14 is separated from the first electrode portion 12F and the second electrode portion 12S. The insulating portion 14 is a partition wall that separates the water tank portion 11 into a first electrode portion 12F side and a second electrode portion 12S side. The insulating portion 14 forms a first chamber 11F on the first electrode portion 12F side of the water tank portion 11, and a second chamber 11S on the second electrode portion 12S side of the water tank portion 11. The first opposing surface 17F and the insulating portion 14, and the second opposing surface 17S and the insulating portion 14, are parallel to each other, and the distance between them is equal everywhere.

[0017] A plurality of fine holes 18 are formed in the insulating portion 14. Each hole 18 penetrates from the first chamber 11F to the second chamber 11S. The penetration direction of each hole 18 is parallel to the X-axis.

[0018] As shown in FIG. 2, the cross-sectional shape of each hole 18 perpendicular to the penetration direction is circular. All holes 18 have the same shape and size. The diameter dimension S1 of each hole 18 perpendicular to the penetration direction is 20 μm or more and 100 μm or less. The diameter dimension S1 is the dimension on the YZ plane. The number of holes 18 provided in the insulating section 14 is 200 or more and 1000 or less per 1 J of pulse energy applied by the power supply unit 13. The pulse energy is the energy per pulse. The number of holes 18 is a value converted to the number per 1 J of pulse energy applied by the power supply unit 13. All holes 18 are arranged at predetermined intervals S2 and S3 in the vertical and horizontal directions. The intervals S2 and S3 are the shortest distance between the outer edges of adjacent holes 18 in the YZ plane. The intervals S2 and S3 are 1 mm or more. The intervals S2 and S3 may or may not be equal to each other.

[0019] The pair of cover portions 15F, 15S are made of an insulating material and are in close contact with the first opposing surface 17F of the first electrode portion 12F and the second opposing surface 17S of the second electrode portion 12S, as shown in FIG.

[0020] As shown in FIG. 3, both the first cover portion 15F and the second cover portion 15S are frame-shaped and surround the opening 19. As shown in FIG. 1, the first cover portion 15F is arranged along the outer edge of the first opposing surface 17F. The second cover portion 15S is arranged along the outer edge of the second opposing surface 17S. The first cover portion 15F and the second cover portion 15S cover the interface portions of the first opposing surface 17F and the second opposing surface 17S that face both the water 16 and the gas. As a result, the first opposing surface 17F and the second opposing surface 17S are in direct contact only with the water 16. In other words, the first opposing surface 17F and the second opposing surface 17S do not have any points that come into contact with both the gas and the water 16. This structure can prevent a phenomenon called creeping discharge that occurs between a point on first opposing surface 17F that comes into contact with both gas and water 16 and a point on second opposing surface 17S that comes into contact with both gas and water 16 when a pulse voltage is applied, in which electricity flows through the air without passing through holes 18 in the water provided in insulating portion 14. When creeping discharge occurs, the flow of pulse energy through the path from first opposing surface 17F to holes 18 in insulating portion 14 to second opposing surface 17S decreases, and the amount of hydrogen peroxide produced decreases.

[0021] In the device 10, when the power supply unit 13 is activated, a pulsed high voltage is applied between the pair of electrodes 12F, 12S, concentrating an electric field at each hole 18 in the insulating unit 14 to generate plasma. When potable, contaminant-free tap water is used, the plasma energy is not used to decompose the contaminants, and high-concentration hydrogen peroxide is generated. By providing multiple holes 18 on the insulating unit 14, the number of plasma generation locations increases, allowing for a higher concentration of hydrogen peroxide to be obtained in a shorter time than with a single hole 18. Furthermore, the more holes 18 there are, the greater the amount of hydrogen peroxide generated per unit time. However, if there are too many holes, the current density per hole decreases, preventing plasma generation, and the hydrogen peroxide concentration per unit time actually decreases. The preferred number of holes 18 is between 200 and 1,000 per 1 J of pulse energy.

[0022] The size of the pores 18 should be 100 μm or less, and the smaller the better. The smaller the size of the pores 18, the higher the current density can be with less energy, and more hydrogen peroxide can be generated with the same amount of energy. Also, the size of the pores 18 should be 20 μm or more. If the size of the pores 18 is less than 20 μm, the current will not flow at all, and plasma and hydrogen peroxide will not be generated.

[0023] The spacing S2 and S3 between the holes 18 is preferably 1 mm or more. If the spacing S2 and S3 between the holes 18 is less than 1 mm, the holes 18 will compete for energy, preventing the current density from increasing and reducing the amount of hydrogen peroxide produced.

[0024] The thickness of insulating part 14 is preferably 150 to 200 μm. The thinner insulating part 14 is, the easier it is to generate plasma and hydrogen peroxide, but pores 18 in insulating part 14 are more likely to widen due to deterioration, reducing the durability of insulating part 14. On the other hand, if insulating part 14 is too thick, the electrical resistance at pores 18 increases, making it difficult to generate plasma and hydrogen peroxide.

[0025] The material of the insulating part 14 can be selected from insulators such as alumina ceramic and polyimide resin. Because the holes 18 of the insulating part 14 become hot due to plasma generation, a heat-resistant material is preferable. Furthermore, the material of the insulating part 14 should have a low dielectric constant. This is because the applied pulse energy has a mountain-like shape with constantly changing potential as shown in Figure 4, so if the insulating part 14 has a high dielectric constant, a current will flow due to dielectric. To prevent this, the insulating part 14 should have a low dielectric constant, and polyimide resin or alumina ceramic is preferable.

[0026] The higher the electrical conductivity of water 16, the better. If the electrical conductivity of water 16 is low, pulse energy is consumed to energize and heat the water itself, resulting in poor hydrogen peroxide production efficiency. Therefore, the water filled into hydrogen peroxide generator 10 of the present invention may be water to which an electrolyte such as salt has been added in advance, or water whose conductivity has been changed by electrolysis.

[0027] The polarity of the pair of electrodes 12F, 12S may be periodically reversed. By periodically reversing the polarity of the pair of electrodes 12F, 12S, components derived from water 16 that precipitate on the electrode surfaces during operation of the device can be removed. The polarity may be reversed for each pulse or each time hydrogen peroxide is generated.

[0028] <Experiment> Experiments were conducted using an experimental device 10 regarding the number of holes, hole diameter, and hole spacing in the insulating part 14. The number of holes is the number of holes 18 in the insulating part 14 provided in one device 10. The shape of each hole 18 on the YZ plane is circular. The hole diameter is the diameter dimension S1 of the hole 18. The hole diameters of all holes 18 are the same value. The hole spacing is the shortest distance S2, S3 between the outer edges of adjacent holes 18 on the YZ plane. The hole spacing is equal in both the vertical and horizontal directions.

[0029] The experimental device 10 has the following configuration. The first electrode portion 12F and the second electrode portion 12S are graphite carbon electrodes. The distance D between the first electrode portion 12F and the second electrode portion 12S is 14 mm. The distance D is the distance on the X-axis between the first opposing surface 17F and the second opposing surface 17S. The insulating portion 14 is made of polyimide resin. The thickness dimension T1 of the insulating portion 14 is 200 μm. The pair of cover portions 15F, 15S are both made of silicone rubber. The thickness dimension T2 of the cover portions 15F, 15S is 1 mm. The thickness dimensions T1, T2 of the insulating portion 14 and the cover portions 15F, 15S are both dimensions on the X-axis.

[0030] The power supply unit 13 is an MPC3010S-50SP manufactured by Suematsu Electronics Manufacturing Co., Ltd. The output voltage waveform from the power supply unit 13 is as shown in Figure 4. The maximum applied voltage of the power supply unit 13 is 10 kV. The application time of the power supply unit 13 is 4 ns / pulse. The application time is the application time at half the maximum applied voltage. The pulse energy per pulse applying a maximum applied voltage of 10 kV for an application time of 4 ns is 1 J. The application frequency is 150 pulses / second. The cumulative number of applications is 1 million pulses. The water 16 is tap water from Kumamoto City. The electrical conductivity of the water 16 is 230 μS / cm.

[0031] Experiment 1: Number of holes and hole diameter The hole spacing was fixed at 2.5 mm, and the number of holes and hole diameter were varied, and the concentration (mg / L) of the generated aqueous hydrogen peroxide solution was measured. The concentration of aqueous hydrogen peroxide is the amount of hydrogen peroxide contained in the aqueous hydrogen peroxide solution. The results of Experiment 1 are shown in the table in Figure 5. The number of holes was varied from 136 holes, 275 holes, 555 holes, 760 holes, and 1500 holes. The hole diameter was varied from 10 μm, 20 μm, 30 μm, 60 μm, 90 μm, and 120 μm.

[0032] Results of Experiment 1: Depending on the combination of the number of holes and the hole size, the concentration of hydrogen peroxide generated was zero, low, or high. In the table in Figure 5, high concentrations are indicated by shading. Specifically, when the hole size was 10 μm, the concentration of hydrogen peroxide generated was zero regardless of the number of holes. When the hole size was 90 μm and the number of holes was either 136 or 1500, the concentration of hydrogen peroxide generated was zero. When the hole size was 120 μm and the number of holes was either 136 or 1500, the concentration of hydrogen peroxide generated was zero. When the hole size was 120 μm and the number of holes was either 275, 555, or 760, the concentration of hydrogen peroxide generated was low.

[0033] On the other hand, when the pore size was 20 μm, 30 μm, or 60 μm, and when the pore size was 90 μm and the number of pores was 275, 555, or 760, the concentration of hydrogen peroxide produced was high. From these results, it is considered that the pore size should be between 20 μm and 100 μm.

[0034] The concentration of hydrogen peroxide produced was particularly high when the hole diameter was 20 μm, 30 μm, or 60 μm and the hole count was 275, 555, or 760. From this result, it is considered that the hole count should be between 200 and 1000 per 1 J of pulse energy applied by power supply unit 13.

[0035] Experiment 2: Hole spacing The number of holes was fixed at 555, the hole diameter was fixed at 30 μm, and the hole spacing was changed, and the concentration (mg / L) of hydrogen peroxide solution produced was measured. The results of Experiment 2 are shown in the table in Figure 6. The hole spacing was changed to 2.5 mm, 1 mm, and 0.5 mm.

[0036] Results of Experiment 2: Depending on the hole spacing, the concentration of hydrogen peroxide generated was either low or high. In the table of Figure 6, high concentrations are indicated by shading. Specifically, when the hole spacing was 0.5 mm, the concentration of hydrogen peroxide generated was low. When the hole spacing was either 1 mm or 2.5 mm, the concentration of hydrogen peroxide generated was high. From these results, it is thought that a hole spacing of 1 mm or more is best. When the hole spacing was 2.5 mm, the concentration of hydrogen peroxide generated was particularly high.

[0037] According to the embodiment configured as above, the following effects are achieved.

[0038] The hydrogen peroxide generator 10 includes a water tank 11, a pair of electrode units 12F, 12S, a power supply 13, and an insulator 14. The water tank 11 stores water 16. The pair of electrode units 12F, 12S are arranged with the water 16 interposed therebetween. The power supply 13 applies a pulsed voltage with a maximum voltage of 1 kV or more to the pair of electrode units 12F, 12S. The insulator 14 is arranged between the pair of electrode units 12F, 12S and divides the water tank 11 into one side, the first electrode unit 12F, and the other side, the second electrode unit 12S. The insulator 14 is an electrical insulator and has a plurality of holes 18 formed therein, penetrating from the first electrode unit 12F side to the second electrode unit 12S side.

[0039] This configuration allows for efficient generation of hydrogen peroxide by locally increasing the current density around each hole 18 in the insulating portion 14. This allows for the generation of highly concentrated hydrogen peroxide solution suitable for disinfecting the home environment.

[0040] The number of holes 18 is 200 or more and 1000 or less per 1 J of pulse energy applied by power supply unit 13. With this configuration, hydrogen peroxide can be produced more efficiently.

[0041] The cross section of hole 18 perpendicular to the penetrating direction is circular. Hole 18 has a diameter S1 perpendicular to the penetrating direction of hole 18 ranging from 20 μm to 100 μm. This configuration allows hydrogen peroxide to be produced more efficiently.

[0042] The shortest distances S2, S3 between the edges of adjacent holes 18 in a direction perpendicular to the penetration direction are 1 mm or more. This configuration makes the current density uniform around each hole 18. Therefore, uneven discharge is suppressed, and hydrogen peroxide can be generated efficiently and stably.

[0043] The device 10 includes a pair of cover parts 15F, 15S that are in close contact with the opposing surfaces 17F, 17S of the pair of electrode parts 12F, 12S, respectively. The pair of cover parts 15F, 15S cover the portions of the opposing surfaces 17F, 17S that may come into contact with gas within the water tank part 11. This configuration prevents current from flowing to anything other than the water in the water tank part 11, thereby enabling more efficient production of hydrogen peroxide. <Other embodiments> The present disclosure is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments, for example, are also included within the technical scope of the present disclosure. (1) In the above embodiment, the cross-sectional shape of the hole 18 is circular. However, the cross-sectional shape of the hole is not limited to this and may be changed. (2) In the above embodiment, all the holes 18 have the same diameter. However, the holes may have different diameters. (3) In the above embodiment, the intervals S2 and S3 between adjacent holes 18 are constant. However, this is not limiting, and the intervals between holes may be variable. (4) In the above embodiment, the vertical spacing S1 and the horizontal spacing S2 between adjacent holes 18 are equal. However, this is not limiting, and the vertical spacing and the horizontal spacing between adjacent holes may be different. (5) In the above embodiment, the holes 18 are arranged linearly in the vertical and horizontal directions. However, the arrangement of the holes is not limited to this and can be changed as appropriate. (6) In the experimental apparatus 10 of the above embodiment, the pulse energy applied by the power supply unit 13 is 1 J. However, the pulse energy applied by the power supply unit may be greater or less than 1 J. In this case, the number of holes may be increased or decreased in proportion to the pulse energy. (7) In the experimental device 10 of the above embodiment, the maximum applied voltage of the power supply unit 13 is 10 kV. However, the maximum applied voltage of the power supply unit is not limited to this, and may be any voltage as long as it is 1 kV or more. [Explanation of symbols]

[0044] 10...Device (hydrogen peroxide generator), 11...Water tank section, 12F, 12S...Pair of electrode sections, 13...Power supply section, 14...Insulating section, 15F, 15S...Pair of cover sections, 16...Water, 18...Hole, S1...Diameter dimension perpendicular to the penetration direction of the hole, S2, S3...Shortest distance between edges of adjacent holes in the direction perpendicular to the penetration direction

Claims

1. A water tank for storing water; a pair of electrode units disposed with the water therebetween; a power supply unit that applies a pulsed voltage having a maximum voltage of 1 kV or more to the pair of electrodes; an insulating part disposed between the pair of electrodes and dividing the water tank part into one electrode part side and the other electrode part side; the insulating portion is an electrical insulator, and has a plurality of holes formed therein that penetrate from the one electrode portion side to the other electrode portion side; The cross-sectional shape of the hole perpendicular to the penetration direction is circular, The diameter of the hole perpendicular to the penetration direction is 20 μm or more and 100 μm or less, A hydrogen peroxide generating device, wherein the shortest distance between the edges of adjacent holes in a direction perpendicular to the penetration direction is 1 mm or more.

2. 2. The hydrogen peroxide generating device according to claim 1, wherein the number of the holes is 200 or more and 1000 or less per 1 J of pulse energy applied by the power supply unit.

3. a pair of cover portions that are in close contact with the opposing surfaces of the pair of electrode portions, The hydrogen peroxide generating device according to claim 1 or 2, wherein the pair of cover portions cover portions of the opposing surfaces that may come into contact with gas within the water tank portion.

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