JP2008063648A - Apparatus for producing rinse water containing hydrogen peroxide, and method for producing rinse water containing hydrogen peroxide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently produce rinse water superior in cleaning capacity containing hydrogen peroxide. <P>SOLUTION: This production method includes supplying micro-bubbles of an oxygen-containing gas, which have a very small bubble diameter and a large surface area, to a cathode chamber 4 of a diaphragm-containing electrolysis tank 3 which has a diaphragm 8 between the cathode chamber 4 and an anode chamber 5; and generating the rinse water containing hydrogen peroxide in the cathode chamber 4. The production method increases a contacting efficiency of triphasic interfaces (bubble/electrolytic solution/electrode) in a cathode 6, which is important for producing hydrogen peroxide, enhances a production efficiency of hydrogen peroxide, and can efficiently produce the rinse water containing hydrogen peroxide. Thus produced rinse water containing hydrogen peroxide includes remaining micro-bubbles which collide with a contaminant depositing on the surface of an article to be cleaned when cleaning the article to detach the contaminant more efficiently than milli-bubbles, and consequently shows superior cleaning capacity. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a manufacturing apparatus and a manufacturing method for hydrogen peroxide-containing cleaning water.

  Conventionally, washing of industrial parts such as liquid crystal and semiconductors in the electronics industry, washing of fresh food processing equipment and tools such as marine products and agricultural products, washing of production lines handling fluid foods and drinks, pharmaceutical manufacturing and cosmetics manufacturing Various cleaning waters are used for cleaning the apparatus and the line. For example, mechanical parts are generally washed with an organic solvent to remove oil or the like adhering to the surface. Further, as the water-soluble cleaning liquid, a surfactant, an alkaline additive or the like is used. Moreover, in CIP (automatic cleaning system) etc. of food industry, the alkaline cleaning liquid excellent in the cleaning effect of fats and oils and organic substances is often used. However, organic solvents can cause environmental pollution problems, and the use of chemicals such as surfactants requires a rinsing step to wash away the surfactants, requiring a large amount of rinsing water. Since the surfactant is an organic substance, a large-scale wastewater treatment facility for treating this is required. In addition, the alkaline cleaning liquid has a problem in cleaning power.

Recently, alkaline electrolyzed water obtained by electrolysis of an aqueous solution has attracted attention as washing water without such problems. In order to enhance the cleaning effect of the alkaline electrolyzed water, a cleaning method using alkaline electrolyzed water containing hydrogen peroxide is described in Patent Document 1 below. In Patent Document 1, oxygen-containing gas is supplied into water or an electrolyte aqueous solution supplied to a cathode chamber of a diaphragm electrolytic cell, hydrogen peroxide is generated on the cathode surface, and alkaline electrolyzed water containing hydrogen peroxide is produced. Trying to get. Moreover, the manufacturing method of hydrogen peroxide suitable for uses, such as pulp bleaching, is described in the following patent document 2. In Patent Document 2, a carbon fiber material having a large surface area is filled on the cathode side, and electrolysis is performed to obtain hydrogen peroxide-containing alkaline water having a relatively high concentration of several percent.
JP 2001-327934 A Japanese Patent Laid-Open No. 6-230309

  However, the technique described in Patent Document 1 has a problem that the generation efficiency of hydrogen peroxide is low.

  In the technique described in Patent Document 2, the packing density of the carbon fiber material is increased to increase the surface area of the cathode and increase the generation efficiency of hydrogen peroxide while reducing the size of the apparatus. As a result, oxygen-containing bubbles accumulate in the packed bed and coalesce to form large bubbles, resulting in a gas pool and an increase in electrical resistance.

  The present invention has been made to solve the above-described problems, and provides a hydrogen peroxide-containing cleaning water production apparatus and a process that can efficiently generate hydrogen peroxide-containing cleaning water having excellent cleaning performance. It aims at providing the manufacturing method of hydrogen oxide containing washing water.

  An apparatus for producing hydrogen peroxide-containing cleaning water according to the present invention includes a diaphragm electrolytic cell having a diaphragm between a cathode chamber and an anode chamber, and a microbubble generator that generates microbubbles of oxygen-containing gas and supplies them to the cathode chamber And generating hydrogen peroxide-containing cleaning water in the cathode chamber.

  According to the method for producing cleaning water containing hydrogen peroxide according to the present invention, microbubbles of oxygen-containing gas are supplied to the cathode chamber of the diaphragm cell having a diaphragm between the cathode chamber and the anode chamber, It is characterized by producing hydrogen oxide-containing cleaning water.

  According to such a hydrogen peroxide-containing washing water production apparatus and production method, since the microbubbles of oxygen-containing gas having a very small bubble diameter and a large surface area are supplied to the cathode chamber of the diaphragm electrolytic cell, The contact efficiency of the three-phase interface (bubble / electrolyte / electrode) at the cathode, which is important for the production of hydrogen peroxide, is improved, and the production efficiency of hydrogen peroxide is increased. For this reason, the hydrogen peroxide-containing cleaning water is efficiently generated. In addition, the microbubbles remaining in the hydrogen peroxide-containing cleaning water collide more effectively with the contaminants attached to the surface of the object to be cleaned during cleaning than the millibubbles, and the contaminants are peeled off. Excellent performance. As described above, hydrogen peroxide-containing cleaning water having excellent cleaning performance can be efficiently generated.

  Here, as a cathode of the cathode chamber which preferably exhibits the above-described action, specifically, a flat fixed electrode may be mentioned.

  In addition, the cathode of the cathode chamber is preferably provided with an electrode filled with a carbon material. When such a configuration is adopted, even if the packing density of the carbon material is increased, since the oxygen-containing bubbles are very small with micro bubbles, the oxygen-containing bubbles accumulate in the packed bed and coalesce into large bubbles. There is no case where accumulation occurs and the electric resistance increases and the electrolysis efficiency decreases. For this reason, the packing density of the carbon material can be increased, and the surface area of the cathode can be increased and the hydrogen peroxide generation efficiency can be further increased while downsizing the apparatus.

  Further, when the oxygen gas generated in the anode chamber is configured to include an oxygen gas supply line that supplies the oxygen gas as an oxygen-containing gas to the microbubble generator, an oxygen-containing gas supply device such as a blower or a cylinder that supplies the oxygen-containing gas This is unnecessary and the cost can be reduced.

  Here, the oxygen-containing gas microbubbles preferably have a bubble diameter of 0.1 to 100 μm.

  Thus, according to the manufacturing apparatus and manufacturing method of the hydrogen peroxide containing cleaning water of this invention, the hydrogen peroxide containing cleaning water excellent in cleaning performance can be produced | generated efficiently.

  Hereinafter, preferred embodiments of a hydrogen peroxide-containing cleaning water manufacturing apparatus and a hydrogen peroxide-containing cleaning water manufacturing method according to the present invention will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram showing an apparatus for producing hydrogen peroxide-containing cleaning water according to the first embodiment.

  The hydrogen peroxide-containing cleaning water production apparatus 100 generally includes a diaphragm membrane electrolysis apparatus 1 and a microbubble generator 2.

  The diaphragm electrolysis apparatus 1 includes a diaphragm electrolytic cell 3 in which a cathode chamber 4 having a cathode 6 and an anode chamber 5 having an anode 7 are separated by a diaphragm 8, and a DC power source 9 is connected to the cathode 6 and the anode 7. Then, by applying a voltage to these electrodes 6 and 7, electrolysis is performed in the tank.

  As the cathode 6 and the anode 7, for example, a flat plate such as a plate, a net, or a perforated plate is used as the fixed electrode, and is arranged to face each other. The cathode 6 is preferably formed from a noble metal such as platinum, stainless steel, nickel, titanium, or the like, and is preferably formed from a sintered body of graphite and activated carbon. In addition, it is particularly preferable to use a porous electrode formed of noble metal fine particles such as platinum or gold and titanium, or a porous sintered body of carbon or graphite powder, in order to promote the hydrogen peroxide generation reaction described later.

  As the diaphragm 8, an ion exchange membrane or a resin porous membrane is used. The ion exchange membrane may be either a cation exchange membrane or an anion exchange membrane, but it is preferable to use a fluororesin ion exchange membrane in view of chemical resistance.

  A cathode chamber electrolyte aqueous solution supply line L1 for introducing an electrolyte aqueous solution is connected to an inflow port of the cathode chamber 4 of the diaphragm membrane electrolytic cell 3, and hydrogen peroxide generated in the cathode chamber 4 is connected to an outflow port. A hydrogen peroxide-containing alkaline electrolyzed water discharge line L2 for discharging the contained alkaline electrolyzed water (described later in detail) is connected. On the other hand, the anode chamber 5 of the diaphragm electrolytic cell 3 is connected to an anode chamber electrolyte aqueous solution supply line L3 for introducing an electrolyte aqueous solution at the inlet, and contains oxygen generated in the anode chamber 5 at the outlet. An acidic electrolyzed water discharge line L4 for discharging acidic electrolyzed water (described later in detail) is connected.

  The microbubble generator 2 generates microbubbles of air or oxygen gas (hereinafter referred to as oxygen-containing gas) and supplies the microbubbles to the cathode chamber 4. The cathode chamber supply water tank 10 and the cathode chamber supply water tank 10 On the other hand, a circulation line L6 in which an inlet and an outlet are connected, a shear type pump P and a shear type nozzle T provided in the middle of the circulation line L6, and a gas supply connected to the upstream side of the shear type pump P in the circulation line L6. The apparatus B is generally provided, and the downstream side of the circulation type line L6 from the shear type nozzle T is connected to the inlet of the cathode chamber 4 by the cathode chamber electrolyte aqueous solution supply line L1.

  The cathode chamber supply water tank 10 stores the aqueous electrolyte solution supplied via the line L5.

  The gas supply device B includes a blower, a cylinder, and the like that supply the oxygen-containing gas to the circulation line L6.

  The shear type pump P is, for example, an intake pump such as a vortex pump, and draws oxygen-containing gas and an aqueous electrolyte solution in the cathode chamber supply water tank 10 through a two-phase swirling flow and circulates them in the circulation line L6 and shears the oxygen-containing gas To do.

  The shear type nozzle T is, for example, a blender or a mixer, and further shears the oxygen-containing gas from the shear type pump P by a swirling flow to generate oxygen-containing gas microbubbles (ultrafine bubbles having a diameter of micrometer level). To do.

  Incidentally, in the electrolysis, since carbonate such as calcium adheres to the surface of the cathode 6 and the electric resistance increases, soft water or pure water not containing calcium or the like is used as water for adjusting the electrolyte aqueous solution. Is preferred. Further, in order to prevent an increase in electrical resistance due to precipitation of sodium carbonate or the like, it is preferable to previously remove the carbon dioxide in the oxygen-containing gas to the aqueous electrolyte solution.

  In the hydrogen peroxide-containing cleaning water production apparatus 100 having such a configuration, the oxygen-containing gas supplied from the gas supply apparatus B to the circulation line L6 by driving the shear pump P in the microbubble generator 2. Is sent to the shear type pump P together with the electrolyte aqueous solution in the cathode chamber supply water tank 10 and sheared by the two-phase swirl flow, and further sheared by the swirl flow by the shear type nozzle T, whereby the oxygen-containing gas microbubbles are formed. appear.

  As described above, since the microbubbles are generated by the two-stage swirl flow using the shear pump P and the shear nozzle T, an electrolyte aqueous solution containing microbubbles of an ultrafine oxygen-containing gas can be stably obtained. It is done.

  The aqueous electrolyte solution containing the oxygen-containing gas microbubbles is supplied to the cathode chamber 4 of the diaphragm electrolytic cell 3 through the cathode chamber electrolyte aqueous solution supply line L1, while a part of the cathode chamber is supplied by the circulation line L6. It returns to the supply water tank 10 and circulates. On the other hand, the aqueous electrolyte solution is supplied to the anode chamber 5 via the anode chamber electrolyte aqueous solution supply line L3. Then, a voltage is applied to the electrodes 6 and 7 by the DC power source 9, whereby electrolysis is performed in the diaphragm membrane electrolytic cell 3.

At this time, reaction formula (1) shown below by electrolysis in the cathode chamber 4:
O ₂ + 2H ₂ O + 2e → H ₂ O ₂ + 2OH ⁻ (1)
Hydrogen peroxide is generated according to

  On the surface of the cathode 6, the above reaction formula (1) proceeds at the three-phase interface of microbubbles of oxygen-containing gas / electrolyte / electrode.

  Here, the microbubbles of the oxygen-containing gas are finer bubbles than bubbles (millibubbles; bubbles with a diameter of millimeter level) generated using a diffuser plate or a diffuser sphere such as a porous ceramic. Specifically, since the bubble diameter is 0.1 to 100 μm (more preferably 1 to 50 μm) and the surface area is large, the contact efficiency of the three-phase interface at the cathode 6 which is important for the generation of hydrogen peroxide is improved. In addition, the generation efficiency of hydrogen peroxide is increased.

  As described above, the bubble diameter of the microbubble is set to 0.1 to 100 μm. If the bubble diameter is smaller than 0.1 μm, a complicated device is required to generate such ultrafine bubbles. This is because even if such ultrafine bubbles are used, the efficiency of hydrogen peroxide generation does not increase any more, and if the bubble diameter is larger than 100 μm, the three-phase interface at the cathode 6 will not be increased. This is because the contact efficiency is lowered and the production efficiency of hydrogen peroxide is lowered.

  Here, since the microbubbles having such a bubble diameter (0.1 to 100 μm) have a property that the bubbles are difficult to coalesce due to electrostatic repulsion, the cell voltage in the cathode chamber 4 is Will not rise, and stable electrolysis will be performed.

  In this manner, hydrogen peroxide-containing alkaline electrolyzed water containing hydrogen peroxide is generated efficiently and stably in the cathode chamber 4.

On the other hand, in the anode chamber 5, the following reaction formula (2) is obtained by electrolysis:
2OH ⁻ → H ₂ O + 1 / 2O ₂ + 2e (2)
Accordingly, oxygen gas is generated, and oxygen-containing acidic electrolyzed water containing oxygen gas is generated.

  The hydrogen peroxide-containing alkaline electrolyzed water efficiently generated in the cathode chamber 4 is discharged as hydrogen peroxide-containing cleaning water through the hydrogen peroxide-containing alkaline electrolyzed water discharge line L2, and various production lines that require cleaning are used. It is supplied to the cleaning equipment (tank) and used.

  On the other hand, the oxygen-containing acidic electrolyzed water generated in the anode chamber 5 is discharged through the acidic electrolyzed water discharge line L4. This oxygen-containing acidic electrolyzed water contains chlorine, hypochlorite, etc. when salt is used as the electrolyte to be supplied to the anode chamber 5, and should be used as cleaning water having oxidizing power and sterilizing power. Is possible.

  As described above, in the present embodiment, since the microbubbles of the oxygen-containing gas having a very small bubble diameter and a large surface area are supplied to the cathode chamber 4 of the diaphragm electrolytic cell 3, it is important for the generation of hydrogen peroxide. The contact efficiency at the three-phase interface at the negative electrode 6 is improved, the generation efficiency of hydrogen peroxide is increased, and the hydrogen peroxide-containing cleaning water is efficiently generated. In addition, the microbubbles remaining in the hydrogen peroxide-containing cleaning water collide more efficiently with the contaminants adhering to the surface of the object to be cleaned at the time of cleaning than the millibubbles. Excellent performance. Therefore, according to the present embodiment, it is possible to efficiently generate hydrogen peroxide-containing cleaning water having excellent cleaning performance.

  In addition, since hydrogen peroxide has the effect of oxidative decomposition of contaminated organic substances and sterilization of bacteria, the generated hydrogen peroxide-containing cleaning water is more effective for cleaning and sterilization than simple alkaline electrolyzed water. Can be done. In addition, since the hydrogen peroxide-containing cleaning water has a high detergency, it is possible to reduce the amount of expensive sodium hydroxide used (reduce the alkali concentration).

  In the microbubble generator 2, the shear type nozzle T is installed outside the cathode chamber supply water tank 10, but may be installed in the electrolyte aqueous solution in the cathode chamber supply water tank 10.

  In addition to the oxygen-containing gas shearing method using a combination of the shear-type pump P and the shear-type nozzle T, the microbubble generator 2 can be used, for example, from the state in which the oxygen-containing gas is dissolved in the electrolyte aqueous solution by pressurization. A pressure dissolution method or the like that generates microbubbles by discharging the aqueous solution from a nozzle or the like and bringing it into a constant pressure state at once may be employed.

  Further, when only a small amount of air as the oxygen-containing gas needs to be supplied to the circulation line L6, the gas supply device B is eliminated, and the atmosphere is sucked by the shear pump P and supplied to the circulation line L6. good.

  Further, a part of the electrolyte aqueous solution containing the microbubbles of oxygen-containing gas is circulated back to the cathode chamber supply water tank 10 through the circulation line L6, but the entire electrolyte aqueous solution containing the microbubbles of oxygen-containing gas is circulated. May be supplied to the cathode chamber 4 by the cathode chamber electrolyte aqueous solution supply line L1.

  FIG. 2 is a schematic configuration diagram showing an apparatus for producing hydrogen peroxide-containing cleaning water according to the second embodiment of the present invention.

  The hydrogen peroxide-containing cleaning water manufacturing apparatus 200 of the second embodiment is different from the hydrogen peroxide-containing cleaning water manufacturing apparatus 100 of the first embodiment in that instead of the diaphragm membrane electrolytic cell 3 having the cathode 6, carbon This is a point using a diaphragm membrane electrolytic cell 13 having a cathode 11 filled with a material.

  Here, the cathode 11 is, for example, an electrode filled with carbon fiber felt, carbon fiber cloth, carbon fiber sheet, granular carbon material, or the like.

  Along with this change, the cathode chamber 4 is provided with a power supply body (current supply device) 16 that is connected to the power source 9 and supplies current to the cathode 11. As the power supply body 16, for example, a metal such as carbon, conductive nickel, or titanium can be used.

  According to the hydrogen peroxide-containing cleaning water manufacturing apparatus 200 of the second embodiment, even if the filling density of the carbon material constituting the cathode 11 is increased, the oxygen-containing bubbles are microbubbles and are very small. There is no case where oxygen-containing bubbles accumulate in the packed bed and coalesce to form large bubbles, resulting in gas accumulation, an increase in electrical resistance, and a reduction in electrolysis efficiency.

  Therefore, in addition to the effects of the first embodiment, it is possible to increase the packing density of the carbon material constituting the cathode 11, increase the surface area of the cathode 11 while further reducing the size of the apparatus, and further increase the generation efficiency of hydrogen peroxide. it can.

  FIG. 3 is a schematic configuration diagram showing an apparatus for producing hydrogen peroxide-containing cleaning water according to the third embodiment of the present invention.

  The hydrogen peroxide-containing cleaning water manufacturing apparatus 300 of the third embodiment is different from the hydrogen peroxide-containing cleaning water manufacturing apparatus 200 of the second embodiment in that oxygen-containing acidic electrolyzed water is supplied to the acidic electrolyzed water discharge line L4. A gas-liquid separator 12 for gas-liquid separation is provided, and a micro-bubble generator 22 without the gas supply device B is used in place of the micro-bubble generator 2, and the gas separation side of the gas-liquid separator 12 and micro-bubble generation are performed. This is the point where the upstream side of the shear line pump P of the circulation line L6 of the device 22 is connected by the oxygen gas supply line L7.

  According to the hydrogen peroxide-containing cleaning water production apparatus 300 of the third embodiment, the oxygen-containing acidic electrolyzed water discharged through the acidic electrolyzed water discharge line L4 is oxygen gas and acidic electrolysis by the gas-liquid separator 12. The gas is separated into water and oxygen gas is supplied to the circulation line L6 of the microbubble generator 22 through the oxygen gas supply line L7. In the microbubble generator 22, oxygen is contained without using the gas supply device B. An aqueous electrolyte solution containing gas microbubbles is produced.

  Therefore, in addition to the effects of the second embodiment, the gas supply device B is not required, and the cost can be reduced.

  As described above, the present invention has been specifically described based on the embodiment. However, the present invention is not limited to the above-described embodiment. For example, the configuration using the oxygen gas supply line L7 of the third embodiment is described below. It is also possible to apply to one embodiment.

It is a schematic block diagram which shows the manufacturing apparatus of the hydrogen peroxide containing washing water which concerns on 1st embodiment of this invention. It is a schematic block diagram which shows the manufacturing apparatus of the hydrogen peroxide containing washing water which concerns on 2nd embodiment of this invention. It is a schematic block diagram which shows the manufacturing apparatus of the hydrogen peroxide containing washing water which concerns on 3rd embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2,22 ... Microbubble generator, 3,13 ... Separator membrane electrolytic cell, 4 ... Cathode chamber, 5 ... Anode chamber, 6 ... Cathode, 8 ... Septum, 11 ... Filling electrode (electrode filled with carbon material; cathode) , 100, 200, 300 ... hydrogen peroxide-containing cleaning water production apparatus, L7 ... oxygen gas supply line.

Claims (6)

A diaphragm electrolytic cell having a diaphragm between the cathode chamber and the anode chamber;
A microbubble generator for generating microbubbles of oxygen-containing gas and supplying the microbubbles to the cathode chamber,
An apparatus for producing hydrogen peroxide-containing cleaning water, wherein hydrogen peroxide-containing cleaning water is generated in the cathode chamber.   The apparatus for producing cleaning water containing hydrogen peroxide according to claim 1, wherein the cathode of the cathode chamber is a flat fixed electrode.   The apparatus for producing cleaning water containing hydrogen peroxide according to claim 1, wherein the cathode of the cathode chamber includes an electrode filled with a carbon material.   The oxygen gas supply line which supplies the oxygen gas produced | generated in the said anode chamber to the said microbubble generator as the said oxygen containing gas was provided, The excess gas as described in any one of Claims 1-3 characterized by the above-mentioned. Production equipment for cleaning water containing hydrogen oxide.   The apparatus for producing hydrogen peroxide-containing cleaning water according to claim 1, wherein the oxygen-containing gas microbubbles have a bubble diameter of 0.1 to 100 μm.   A microbubble of oxygen-containing gas is supplied to the cathode chamber of a diaphragm electrolytic cell having a diaphragm between the cathode chamber and the anode chamber, and hydrogen peroxide-containing cleaning water is generated in the cathode chamber. A method for producing hydrogen peroxide-containing cleaning water.

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