WO2012132963A1

WO2012132963A1 - Method for starting up ozone-generating electrolytic cell

Info

Publication number: WO2012132963A1
Application number: PCT/JP2012/056874
Authority: WO
Inventors: 理恵川口; 昌明加藤
Original assignee: クロリンエンジニアズ株式会社
Priority date: 2011-03-30
Filing date: 2012-03-16
Publication date: 2012-10-04
Also published as: JPWO2012132963A1; TWI512143B; TW201307614A

Abstract

Provided is a zero-gap type ozone-generating electrolytic cell, wherein the amount of hydrogen that is generated in a negative pole chamber and passes to a positive pole chamber is reduced. An ozone-generating electrolytic cell (1) in which a positive pole chamber (21) and negative pole chamber (31) are formed by provision of a positive pole (20) and negative pole (30) at both side faces of a fluorine resin-based positive-ion exchange film (10), ozone is generated from the positive pole (20) and hydrogen is generated from the negative pole (30) as a result of subjecting pure water supplied to the positive pole chamber (21) to electrolysis by supplying DC current between the positive pole and negative pole, wherein washing of the positive pole (20) is performed as a start-up treatment.

Description

Starting method of electrolytic cell for ozone generation

The present invention relates to a starting method for supplying current to an electrolytic cell for ozone generation for the first time.

As an apparatus for electrolyzing water, there is one utilizing a so-called zero gap type electrolysis cell in which an anode is closely attached to one surface of a cation exchange membrane and a cathode is closely attached to the other surface. Zero-gap electrolytic cells can reduce the electrolysis voltage because they do not energize the liquid phase, and can directly electrolyze pure water that cannot be electrolyzed by ordinary electrolysis methods because of their low conductivity. Since it can be easily made compact, it is widely used in water / electrolysis devices for oxygen / hydrogen generation, electrolytic ozone generators, and the like. As an electrode structure used for such an electrolytic cell, an electrode structure in which an electrode catalyst is disposed between a current collector or a substrate and a cation exchange membrane is known for the purpose of improving electrolytic performance and stability. (See Patent Documents 1 to 4).

In the zero gap type pure water electrolysis cell, the electrolytic reaction is carried out only at the three-phase interface where the cation exchange membrane / electrode catalyst / pure water contacts. In the anode, the following electrolytic reactions (F1) and (F2) occur at the three-phase interface where the anode catalyst / cation exchange membrane / pure water contact, and ozone gas and oxygen gas are generated. Hydrogen gas is generated by the following reduction reaction (F3) at the three-phase interface that passes through the cation exchange membrane by the gradient and contacts the cathode catalyst / cation exchange membrane / pure water (transfer water from the anode) of the cathode.
(Anode reaction)
3H ₂ O → O ₃ + 6H ⁺ + 6e ⁻ (F1)
2H ₂ O → O ₂ + 4H ⁺ + 4e ⁻ (F2)
(Cathode reaction)
2H ⁺ + 2e ⁻ → H ₂ (F3)

The gas generated at the three-phase interface of each electrode grows into bubbles of a certain size, then passes through the current collector from the three-phase interface and is discharged out of the electrolysis device. Due to the concentration diffusion, part of the generated gas passes through the cation exchange membrane and moves to the counter electrode. For example, hydrogen generated at the three-phase interface of the cathode permeates the ion exchange membrane, moves to the anode as the counter electrode, and is discharged out of the cell mixed with ozone gas and oxygen gas.

However, the movement of hydrogen to the anode causes a deterioration in the performance of the electrolytic cell, such as the purity of ozone gas and the efficiency of ozone generation. In addition, because hydrogen and oxygen mixed gas exceeding the lower explosion limit may be generated due to the transfer of hydrogen to the anode, for the safe operation of the electrolysis cell, it is necessary to monitor the counter electrode gas mixture. Need attention.

The present applicant pays attention to the fact that the internal pressure of the bubble, which is the driving force for gas movement to the counter electrode, is affected by the hydrophilicity-hydrophobicity of the electrode catalyst layer according to the Young-Laplace equation. We proposed a water electrolysis device that can suppress gas movement to the counter electrode by using a highly hydrophobic material as the resin in which the catalyst is dispersed. That is, the internal pressure of the hydrogen bubbles generated at the three-phase interface of the cathode is high when the internal pressure is derived from the surface tension of water existing around the bubbles, and the pressure on the hydrophobic surface of the cathode catalyst layer existing around the bubbles. When the internal pressure is derived, the pressure is low. Therefore, if the surface of the cathode catalyst layer is inclined to the hydrophilic side, the internal pressure of the hydrogen bubbles increases, so that it easily moves through the cation exchange membrane and moves to the anode side. Since the internal pressure becomes low, it becomes difficult to move to the anode side. Patent Document 4 stipulates that the contact angle of water on the surface of the cathode catalyst layer is 90 ° or more in the electrolysis cell for generating ozone, and recommends polytetrafluoroethylene having high hydrophobicity as the resin in which the electrode catalyst is dispersed. is doing.

Japanese Patent No. 3080971 Japanese Patent No. 2725799 JP 2005-166500 A JP 2008-274326 A

However, even if the cathode catalyst is dispersed in a highly hydrophobic resin, if the resin surface is contaminated with other substances after the electrolysis cell is operated, the high hydrophobicity that is a characteristic of the resin cannot be exhibited. As a result, the surface of the cathode catalyst layer is inclined to the hydrophilic side, and the internal pressure of the hydrogen bubbles becomes a high value derived from the surface tension of water, and there is a problem that the amount of hydrogen permeation into the anode chamber increases.

The inventors have found that most of the substances that contaminate the surface of the cathode catalyst layer are generated in the anode chamber at the start immediately after supplying current to the electrolysis cell, and are brought from the anode chamber to the cathode chamber through the cation exchange membrane. As a result, the present invention has been completed. The start method of the electrolytic cell for ozone generation according to the present invention is to start reducing the concentration of pollutants in the anolyte in the electrolytic cell for the purpose of reducing the permeation amount of hydrogen generated in the cathode chamber to the anode chamber. Time processing is performed.

That is, the present invention has the configurations described in [1] to [10] below.

[1] An anode chamber and a cathode chamber are formed by providing an anode and a cathode on both sides of a fluororesin cation exchange membrane, and pure water supplied to the anode chamber by supplying a direct current between the anode and the cathode In an electrolytic cell for ozone generation in which ozone is electrolyzed, ozone is generated from the anode, and hydrogen is generated from the cathode, the anode is cleaned as a start-up process.

[2] The electrolysis cell for generating ozone as described in 1 above, wherein, as the start-up treatment, the anode chamber is cleaned at least once by supplying a direct current between the anode and the cathode and then discharging the anolyte and supplying pure water. Starting method.

[3] The method for starting an electrolytic cell for generating ozone as described in the preceding item 2, wherein the discharge of the anolyte is performed while the anode catalyst is immersed in the anolyte.

[4] The method for starting an electrolysis cell for ozone generation according to item 1, wherein the anode is washed with ozone water before assembling the electrolysis cell and the electrolysis cell is assembled using the washed anode.

[5] The method for starting an electrolysis cell for ozone generation according to any one of 1 to 4 above, wherein the anode catalyst layer of the anode is composed of a layer in which the anode catalyst is dispersed in polyvinylidene difluoride.

[6] The start-up method of the electrolytic cell for ozone generation as described in any one of 1 to 4 above, wherein the cathode catalyst layer of the cathode is composed of a layer in which the cathode catalyst is dispersed in polytetrafluoroethylene.

[7] The anode catalyst layer of the anode is composed of a layer in which the anode catalyst is dispersed in polyvinylidene difluoride, and the cathode catalyst layer of the cathode is composed of a layer in which the cathode catalyst is dispersed in polytetrafluoroethylene. 5. The method for starting an electrolytic cell for generating ozone according to any one of 1 to 4 above.

[8] An anode chamber and a cathode chamber are formed by providing an anode and a cathode on both sides of the fluororesin cation exchange membrane, and pure water supplied to the anode chamber by applying a DC voltage between the anode and the cathode An electrolysis cell that generates ozone from the anode and generates hydrogen from the cathode;
An anolyte discharging means for discharging the anolyte from the anode chamber of the electrolysis cell without recirculation;
An electrolytic ozone generator comprising: pure water supply means for supplying pure water to the anode chamber of the electrolytic cell.

[9] An anode chamber and a cathode chamber are formed by providing an anode and a cathode on both sides of the fluororesin cation exchange membrane, and pure water supplied to the anode chamber by supplying a direct current between the anode and the cathode In the electrolytic cell for ozone generation that generates ozone from the anode and generates hydrogen from the cathode,
An electrolytic cell for generating ozone, wherein the anode is washed with ozone water before assembling the electrolytic cell.

[10] An electrolytic ozone generator comprising the ozone generating electrolysis cell as described in 9 above.

According to the invention described in [1] above, the anode is cleaned in the electrolytic cell for ozone generation in which the anode chamber and the cathode chamber are formed by providing the anode and the cathode on both sides of the fluororesin cation exchange membrane. By performing the start-up process, it is possible to reduce the concentration of contaminants in the anolyte at the start of actual operation, and further reduce the amount of contaminants that move from the anode chamber to the cathode chamber. As a result, the amount of contamination-causing substances adhering to the cathode catalyst is reduced and the hydrophobicity of the cathode catalyst is maintained, so that the permeation amount of hydrogen gas generated in the cathode chamber to the anode chamber can be reduced. As a result, high-purity ozone can be obtained, and stable electrolysis can be performed to maintain electrolytic performance for a long period. Moreover, the danger by mixing oxygen (including ozone) gas and hydrogen gas is avoided, and safe operation can be performed.

According to the invention described in [2] above, after the start of electrolysis, the anode and the anode chamber are cleaned by a start-up process by discharging the anolyte and supplying pure water. Contaminant substances generated in the anode chamber together with the discharged anolyte are discharged out of the electrolysis cell, so that the concentration of the pollutant substance in the anolyte can be reduced and the effect described in [1] above can be achieved. Further, since the discharged anolyte does not circulate in the anode chamber and the discharged pollutant does not circulate in the anode chamber, the concentration of the pollutant in the anolyte in the anode chamber can be reliably reduced.

According to the invention described in [3] above, since the state in which the anode catalyst is immersed in water is maintained even after the anolyte is discharged, sufficient ozone is supplied before pure water is supplied after the anolyte is discharged. It is possible to generate and cause pollutants to be generated early and removed early.

According to the invention described in [4] above, since the anode is cleaned with ozone water before the electrolysis cell is assembled, and the electrolysis cell is assembled with the cleaned anode, the pollutant causing the anode is brought into the electrolysis cell. Absent. As a result, the concentration of the contamination-causing substance in the anolyte at the start of electrolysis can be reduced, and the effects described in [1] above can be achieved.

In the invention described in [5] above, the anode catalyst layer of the anode is formed of a layer in which the anode catalyst is dispersed in polyvinylidene difluoride. Polyvinylidene difluoride is more likely to be decomposed by ozone and radicals than other materials, and is one of the factors that increase the concentration of pollutants in the anolyte. Therefore, it is significant to reduce the concentration of pollutants in the anolyte.

In the invention described in [6] above, the cathode catalyst layer of the cathode is formed of a layer in which the cathode catalyst is dispersed in polytetrafluoroethylene. When polytetrafluoroethylene adheres to the pollutant that has moved from the anode chamber, it tilts toward the hydrophilic side, and the internal pressure of the hydrogen bubbles rises to a high value derived from the surface tension of water, increasing the amount of hydrogen permeated into the anode chamber. Therefore, it is significant to apply the start-up process according to the present invention to reduce the concentration of the pollutant substance in the anolyte.

In the invention described in [7] above, the anode catalyst layer of the anode is formed of a layer in which the anode catalyst is dispersed in polyvinylidene difluoride. Polyvinylidene difluoride is more likely to be decomposed by ozone and radicals than other materials, and is one of the factors that increase the concentration of pollutants in the anolyte. Therefore, it is significant to reduce the concentration of pollutants in the anolyte. Further, the cathode catalyst layer of the cathode is formed of a layer in which the cathode catalyst is dispersed in polytetrafluoroethylene. When polytetrafluoroethylene adheres to the pollutant that has moved from the anode chamber, it tilts toward the hydrophilic side, and the internal pressure of the hydrogen bubbles rises to a high value derived from the surface tension of water, increasing the amount of hydrogen permeated into the anode chamber. Therefore, it is significant to apply the start-up process according to the present invention to reduce the concentration of the pollutant substance in the anolyte.

According to the invention described in [8] above, the start-up process for cleaning the anode chamber by discharging the anolyte and supplying pure water described in [2] and [3] is performed, and high-purity ozone is generated. It is possible to obtain a stable electrolysis and maintain the electrolysis performance for a long time. Moreover, the danger by mixing oxygen (including ozone) gas and hydrogen gas is avoided, and safe operation can be performed.

According to each invention described in [9] and [10] above, high-purity ozone can be obtained by performing a start-up process for cleaning the anode before assembling the electrolytic cell described in [4]. The electrolysis performance can be maintained for a long time by performing stable electrolysis. Moreover, the danger by mixing oxygen (including ozone) gas and hydrogen gas is avoided, and safe operation can be performed.

It is a figure which shows typically the structure of the ozone generator which enforces the starting method of the electrolytic cell for ozone generation of this invention. It is a perspective view which shows the washing | cleaning apparatus of an anode or an anode catalyst layer.

[Electrolytic ozone generator]
FIG. 1 is a diagram schematically showing a configuration of an embodiment of an electrolytic ozone generator (M) according to the present invention. In this figure, (1) is an electrolysis cell for ozone generation, (40) is an anolyte circulation device equipped with an anolyte gas-liquid separator (45), (50) is a catholyte gas-liquid separator, and (15) is direct current Power supply.

The electrolytic cell for ozone generation (1) has a porous anode (20) in close contact with one surface of a porous fluororesin cation exchange membrane (10) and a porous cathode on the other surface. (30) is placed in close contact, and the anode side cell frame (11) and cathode side cell frame (12) are placed in close contact from the outside of the anode (20) and cathode (30). This is a cell, and a pressing force is applied from the outside by tightening means (not shown) to enhance the adhesion between the members. The anode (20) comprises an anode current collector or anode substrate (22) and an anode catalyst layer (23), and the cathode (30) comprises a cathode current collector or cathode substrate (32) and a cathode catalyst layer (33). ) And. The inside of the electrolysis cell (1) is divided into an anode chamber (21) and a cathode chamber (31) by a fluororesin-based cation exchange membrane (10), and the anode cell frame (11) is divided into the anode chamber (21). A anolyte supply port (24), an anolyte / gas outlet (25), and an anolyte discharge port (26) are provided, and the cathode side cell frame (12) is connected to the cathode chamber (31). -A gas outlet (35) is provided.

An anode feeding terminal (13) and a cathode feeding terminal (14) are drawn out of the cell from the anode (20) and the cathode (30), respectively, and the anode is fed from the DC power source (15) through these terminals (13) and (14). -A direct current is supplied between the cathodes. When a direct voltage is applied between the anode and the cathode with pure water in the anode chamber (21), the anode chamber (21) is (F1) at the three-phase interface of anode catalyst / cation exchange membrane / pure water. The electrolytic reaction (F2) occurs, and oxygen gas and ozone gas are generated. Hydrogen ions generated by the electrolytic reaction permeate the cation exchange membrane (10) by the potential gradient, and in the cathode chamber (31), the hydrogen ions contact the cathode catalyst layer (33), and the cathode catalyst / cation exchange membrane / Hydrogen gas is generated by the reduction reaction (F3) at the three-phase interface in contact with pure water. The oxygen gas and ozone gas generated in the anode chamber (21) are both led out of the cell from the anolyte / gas outlet (25), and the hydrogen gas generated in the cathode chamber (31) is transferred to the water from the anode. At the same time, it is led out of the cell from the catholyte / gas outlet (35).

The anode chamber (21) and the anolyte circulation device (40) are a first conduit (41) between the anolyte / gas outlet (25) and the anolyte circulation device (10), and an anolyte supply port. (24) and the anolyte circulation device (40) are connected in communication by a second conduit (42) which allows the anolyte to flow between the anode chamber (21) and the anolyte circulation device (40). An anolyte circulation line for circulation is formed. Ozone and oxygen generated in the anode chamber (21) are introduced together with water from the anolyte / gas outlet (25) through the first conduit (41) to the anolyte circulation device (40) and into the second conduit (42). Circulates through the anode chamber (21) through the anolyte circulation line. During this circulation, water containing ozone and oxygen (hereinafter referred to as “ozone water”) can be arbitrarily taken out via a valve (43) provided on the second conduit (42). In addition, the amount of water on the anolyte circulation line can be increased by supplying pure water from the pure water supply path (44) to the anolyte circulation device (40), thereby supplying pure water to the anode chamber (21). Is also conducted through the anolyte circulation line.

In the anodic water circulation device (40), the circulating anolyte is appropriately taken out, and the gas and liquid are separated by the anolyte gas-liquid separation device (45), and the separated gas is supplied to an analyzer not shown. Also, the catholyte that exits the cathode chamber (31) can be taken out as appropriate and separated into a catholyte gas-liquid separator (50) to separate the gas and liquid, and the separated gas is supplied to an analyzer not shown. The Therefore, the composition of the gas component contained in the liquid discharged from the anode chamber (21) and the cathode chamber (31) to the outside of the cell in the electrolytic cell (1) and the gas concentration in the liquid can be analyzed.

Furthermore, the anode side cell frame (11) is provided with an anolyte discharge port (26) that does not belong to the anolyte circulation line, and is connected to a discharge conduit (46). A valve (47) is provided on the discharge conduit (46). By opening the valve (47), the anolyte can be directly discharged from the anode chamber (21) without passing through the anolyte circulation line. .

In the ozone generator (M), supply and stop of direct current between the anode and the cathode, discharge and stop of discharge of the anolyte from the anode chamber (21) by opening and closing the valve (47), Switching between anolyte extraction and circulation from the anolyte circulation line by switching, water supply from the pure water supply path (44) to the anolyte circulation line, and monitoring of the water volume in the anode chamber (21) are manually operated by the operator. Or an automatic operation performed in accordance with conditions set in advance by an anolyte control device (not shown).

In the electrolytic ozone generator (M), the anolyte circulation device (40), the pure water supply channel (44), the second conduit (42) and the anolyte supply port (24) correspond to the pure water supply means in the present invention. The valve (47), the discharge conduit (46) and the anolyte discharge port (26) correspond to the anolyte discharge means in the present invention.

In the present invention, as long as the electrolytic cell (1) is a zero-gap cell in which the anode (20) and the cathode (30) are provided on both sides of the cation exchange membrane (10), the configuration and material thereof are not limited. . The constituent materials of the electrolysis cell (1) that can be recommended are described in detail below.

As the cation exchange membrane (10), a known solid polymer electrolyte membrane can be used. As the resin constituting the solid polymer electrolyte, a perfluorosulfonic acid resin having a sulfonic acid group having a cation exchange function and excellent in chemical stability is particularly preferable.

The anode (21) is obtained by arranging an anode catalyst layer (23) on the cation exchange membrane (10) side of an anode current collector or an anode substrate (22). The anode current collector or anode substrate (22) is a porous structure made of a conductive metal, and is particularly preferably made of a metal having excellent corrosion resistance. Examples of metals that satisfy these conditions include valve metals such as titanium, tantalum, niobium, and zirconium. As porous structures, porous bodies, fiber bodies, nets, foams, and fibers are formed into required shapes by sintering or pressing. What was shape | molded can be illustrated. Examples of the anode catalyst layer (23) include an anode catalyst body in which electrode catalyst particles such as a plating film of lead dioxide, conductive diamond, platinum, and lead dioxide are dispersed in a resin.

The cathode (30) is obtained by disposing a cathode catalyst layer (33) on the cation exchange membrane (10) side of a cathode current collector or a cathode substrate (32). The cathode current collector or the cathode substrate (32) is a porous structure made of a conductive metal. Examples of the conductive material include metals such as stainless steel, nickel, zirconium, titanium, and carbon. As the porous structure, as with the anode, a porous body, a fibrous body, a net-like body, a foamed body, and a fiber are sintered or pressed. What was shape | molded in the required shape can be illustrated. A particularly preferred porous structure is a stainless steel fiber sintered body that is excellent in workability as compared with a valve metal such as titanium, so that a uniform surface is easily obtained, and is excellent in corrosion resistance under negative polarization. The cathode catalyst layer (33) is preferably platinum, platinum black, platinum-supported carbon or the like having a low hydrogen overvoltage as a catalyst, and a porous catalyst layer formed by independently using these catalysts, or these catalyst particles may be polytetrafluoroethylene or the like. A porous thin film dispersed in a fluororesin can be recommended.

Furthermore, in the electrolysis cell (1), various materials can be arbitrarily added in order to enhance the electrolysis performance. For example, by interposing a noble metal layer such as platinum foil between the anode current collector or anode substrate (22) and the anode catalyst layer (23), the contact resistance between the two is reduced and the electrolytic efficiency is increased. Can do.

[Starting method of electrolytic cell for ozone generation]
When pure water is electrolyzed in the electrolytic cell (1), highly oxidative ozone is generated in the anode chamber (21), and radicals such as hydroxy radicals that are more oxidizable than ozone are generated by the self-decomposition of ozone. . These highly oxidizing substances may oxidize the metal when the anode catalyst substrate is a metal, and decompose the resin when the dispersion medium is a resin. Even when a resin having low ozone resistance is used as the dispersion medium for the anode catalyst, it is presumed that the decomposition proceeds rapidly at the start-up, and the decomposition product of the solvent used during the production is also expected to elute into the anolyte. In addition, the cation exchange membrane is composed of a carbon skeleton covered with a fluoro group other than the ion exchange group and has high corrosion resistance, but the residual organic solvent and impurity end groups at the time of manufacture have low corrosion resistance. In addition, it is estimated that decomposition proceeds rapidly at the start-up when ozone generation is performed for the first time. These decomposition products dissolve in the anolyte, contaminate the anode chamber (21), and further permeate the cation exchange membrane (10) to contaminate the cathode chamber (31). Become. Further, when the cathode catalyst layer (33) is contaminated and tilted toward the hydrophilic side, the internal pressure of hydrogen bubbles increases according to the Young-Laplace equation, so that hydrogen permeates the cation exchange membrane (10) and passes through the anode (20 ) Side, and the amount of permeation to the anode chamber (21) increases. As a result, in the anode (20), an electrolytic performance deterioration phenomenon such as a decrease in the purity of ozone gas and a decrease in ozone gas generation efficiency occurs, and the safety of operation decreases due to an increase in the hydrogen concentration in the anode gas.

In the method for starting an electrolytic cell for ozone generation according to the present invention, attention is paid to the fact that most of various decomposition products (hereinafter referred to as “contaminating substances”) that contaminate the anode chamber and the cathode chamber are generated on the anode side at the start. Then, the anode is washed as a start-up process before the actual operation, and the actual operation is started with the concentration of the pollutant in the anolyte as low as possible. The following two types of processing can be recommended as the startup processing.

[First start-up process]
The first start-up process is a process performed immediately after the electrolysis cell (1) is assembled and electrolysis is started. Immediately after the direct current is supplied between the anode and the cathode, the anode (20) and the anode chamber (21) are cleaned once or more by discharging the anolyte and supplying pure water, and generated in the anode chamber (21). Contaminant concentration in the anolyte is reduced by discharging the pollutant out of the electrolysis cell (1).

In the electrolytic ozone generator (M) described above, the anolyte is discharged through the discharge conduit (46) by opening the valve (47). Since the discharge conduit (46) is a flow path not included in the anolyte circulation line, contaminants originating from the anode (20) and the cation exchange membrane (10) must be mixed into the anolyte circulation line. Without being discharged from the anode chamber (21) together with the anolyte. Since the discharged anolyte does not circulate to the anode chamber (21) and the discharged pollutant does not circulate to the anode chamber (21), the concentration of the pollutant in the anode chamber (21) can be reliably reduced. When pure water is supplied to the anode chamber (21), pure water is introduced into the anolyte circulation device (40) through the pure water supply passage (44) and is passed through the second conduit (42) of the anolyte circulation line. Supplied from the anolyte supply port (24). Since pure water is supplied to the anode chamber (21) through the anolyte circulation line without coming into contact with the discharged anolyte, clean water is always supplied.

Since pollutants are generated by ozone and radicals generated by electrolysis, the start-up treatment is performed by applying a current between the two electrodes with the anode catalyst layer (23) and cation exchange membrane (10) in contact with pure water. Perform as supplied. Although the present invention does not prescribe the discharge timing of the anolyte, since ozone is generated immediately after energization and a pollutant is generated, it may be contaminated with the anolyte as soon as possible after energization. It is particularly preferable to start discharging the anolyte simultaneously with energization. Further, when discharging the anolyte, it is preferable to discharge the anolyte so that the anode catalyst layer (23) is kept in contact with the anolyte, and to continue supplying a direct current between both electrodes during cleaning. Thus, ozone can be sufficiently generated even after the anolyte is discharged and pure water is supplied, so that the pollutant can be generated early and removed early. In addition, when the anode catalyst uses lead dioxide, it is not preferable that the anode catalyst is brought into contact with water in a state where no current is supplied. It is preferred that the anodic catalyst layer (23) is in contact with the anolyte and continues to supply current. In order to perform the cleaning while generating ozone in this way, it is only necessary to leave a part of the anolyte and discharge the anolyte without emptying the anode chamber (21). By leaving a part of the anolyte in the anodic chamber (21), a part of the cause of contamination remains, but the discharge of the anolyte and the supply of pure water are repeated according to the amount of the remaining cause of contamination, and washing is performed multiple times. The contamination-causing substance can be removed from the anode chamber (21). The time from the discharge of the anolyte to the supply of pure water can be arbitrarily set. You may supply immediately after discharge | emission, and you may supply after time.

In the present invention, the discharge of anolyte and the supply of pure water are counted as one cleaning, and at least one cleaning may be performed, and the number of cleaning is not limited. Since the amount of contamination-causing substances varies depending on the material characteristics of the anode catalyst layer (23) and cation exchange membrane (10) and the amount of solvent remaining in the resin used in these, the number of washings depends on the anode catalyst layer used ( 23) and the cation exchange membrane (10) may be set as appropriate. Moreover, when performing 2 times or more of washing | cleaning, you may wash | clean continuously and may wash | clean intermittently. Further, the discharge amount of the anolyte, the supply amount of pure water, the time interval from drainage to supply, and the cleaning time interval need not be constant, and may be changed.

Electrolytic ozone generator (M) is put into full operation after performing the start-up process by the above method. Since the operation is carried out with the concentration of the cause of contamination in the anolyte lowered, the amount of the contaminant causing the permeation to the cathode side during the operation is reduced, and the contamination causing agent adheres to the cathode catalyst layer (33). Can be prevented. Therefore, since the hydrophobicity of the cathode catalyst layer (33) is maintained, the amount of hydrogen permeating into the anode chamber (21) is reduced, and high purity ozone can be obtained at the anode (20), and oxygen can be obtained. The danger of mixing gas (including ozone) and hydrogen gas is avoided and safe operation is possible. Since many of the pollutants are generated at the time of starting, stable electrolysis can be performed by removing them before the actual operation, and the electrolysis performance can be maintained for a long time.

In addition, the structure of the electrolytic ozone generator which implements the method of this invention is not limited to FIG. 1, A various change is possible as long as the process at the time of start-up by discharge | emission of an anolyte and supply of a pure water can be performed. For example, a pure water supply port may be separately provided in the electrolysis cell (1) so that pure water is supplied without going through the anolyte circulation line. Alternatively, the first conduit (41) of the anolyte circulation line may be branched so that the anolyte is discharged before the anolyte circulation device (40), and the anolyte is not circulated to the anode chamber (21). Can be discharged. Furthermore, the electrolytic ozone generator does not require circulation of the anolyte.

In addition, operations related to start-up processing, that is, opening and closing of the valve (47) for discharging the anolyte from the anode chamber (21), setting of the discharge amount, supply of pure water through the pure water supply channel (44), pure water The setting of the supply amount, the time interval from discharge to supply, the number of times of cleaning, the time interval when cleaning two or more times, etc. may be automatically set according to the conditions set in advance in the control device. It may be done manually.

[Second start-up process]
The second start-up process is a process performed before the assembly of the electrolysis cell (1), and is a process for preventing a pollutant substance derived from the anode (20) from being brought into the electrolysis cell (1).

As mentioned above, since some of the pollutants are derived from the constituent materials of the anode (20), the anode (20) is previously washed with ozone water to remove the pollutants and washed. By assembling the electrolytic cell using the anode (20), the hydrophobicity of the cathode catalyst layer (33) can be maintained and the permeation amount of hydrogen into the anode chamber (21) can be reduced. In addition, since the pollutant is derived from the resin of the anode catalyst layer (23) and the residual solvent used in the production, particularly among the anode (20), the anode (20) can be used as the anode current collector or anode substrate (22 ) And the anode catalyst layer (23), at least the anode catalyst layer (23) is washed with ozone water in advance to maintain the hydrophobicity of the cathode catalyst layer (33), thereby providing a hydrogen anode chamber (21). The amount of permeation to can be reduced.

In the ozone water cleaning of the anode (20) or the anode catalyst layer (23), for example, they are immersed in ozone water for a predetermined time, and during this time, pollutants are generated by ozone or radical decomposition and eluted into ozone water. By doing.

Ozone water can be generated and cleaned using, for example, a cleaning device (60) referred to in FIG. That is, pure water and the anode catalyst layer (23) or the anode (20) are placed in a sealed air diffuser bottle (61), and ozone gas is blown into the pure water from the introduction pipe (62) to dissolve the ozone gas in the water. The anode catalyst layer (23) is immersed in ozone water by blowing ozone water continuously for a predetermined time. In FIG. 2, (63) is an exhaust pipe for waste gas containing waste ozone.

Although this invention does not prescribe | regulate cleaning conditions, since it can wash | clean in a short time, so that the ozone concentration in ozone water is high, it is preferable that ozone concentration is as high as possible, and it is preferable to set it as a saturated concentration. The saturated ozone concentration at room temperature (25 ° C.) is 40 ppm. Moreover, when using the washing | cleaning apparatus (60) mentioned above, it is preferable to make ozone density | concentration in ozone water reach predetermined density | concentration (for example, saturation density | concentration) for a short time, Therefore Ozone gas blown into a pure water uses high concentration ozone gas. Is preferred. For example, when a zero gap type pure water electrolysis cell is operated at a liquid temperature of 30 ± 5 ° C., an ozone gas of 198 to 205 g / Nm ³ can be obtained. If such a high concentration ozone gas is used, a saturated concentration can be reached in a short time. be able to. In addition, the immersion time is appropriately set so that the pollutant is sufficiently eluted in the ozone water according to the characteristics of the material constituting the anode catalyst layer (23) and the amount of the solvent remaining without being removed during the production. . However, when lead dioxide is in a non-energized state and is in contact with water for a long time, lead dioxide is reduced to other substances and the electrolytic performance is reduced, so if the anode catalyst is lead dioxide, lead dioxide It is preferable to clean in a short time so as not to cause degradation of electrolytic performance. Specifically, in order to perform cleaning in as short a time as possible, it is preferable to perform cleaning for 30 minutes to 2 hours using ozone water having a saturated ozone concentration. Conductive diamond and platinum do not change to other substances even if they are brought into contact with water in a non-energized state, so that degradation of electrolytic performance due to long-time cleaning does not occur.

The starting method of the electrolytic cell for ozone generation according to the present invention can be applied regardless of the type and characteristics of the materials constituting the anode, the cation exchange membrane, and the cathode. It is possible to reduce the concentration of pollutant substances. Especially, the significance of application is great when the anode catalyst layer is composed of a layer in which the anode catalyst is dispersed in a resin. The reason is that the resin is more likely to be decomposed by ozone and radicals than other materials, and becomes one of the factors that increase the concentration of pollutants in the anolyte. In addition, the present invention has great significance for an anode catalyst layer using polyvinylidene difluoride among resins. Polyvinylidene difluoride is an ozone-resistant resin that can be used in ozone-generating electrolysis cells, but it generates less pollutants because it has a lower ozone resistance than the widely used polytetrafluoroethylene. It is because there is a possibility of making it.

In addition, the present invention has great significance when the resin constituting the anode catalyst layer is a copolymer containing vinylidene difluoride as a monomer. Examples of the copolymer include terpolymers of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride. The terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene difluoride (abbreviated as “THV copolymer” in the following description) is more preferable than vinylidene difluoride (—CH ₂ CF ₂ —). By having tetrafluoroethylene (—CF ₂ CF ₂ —) and hexafluoropropylene (—CH ₂ CF (CF ₃ ) —) having high chemical stability in the monomer, ozone and more than the above-mentioned polyvinylidene difluoride. High resistance to radicals. However, this is because the presence of vinylidene difluoride in the monomer may generate more pollutants than polytetrafluoroethylene.

The anode catalyst layer using the THV copolymer generates less contamination-causing substances than the anode catalyst layer using polyvinylidene difluoride, so the number of washings is reduced in the first start-up process. In the start-up process, cleaning conditions such as shortening the immersion time in ozone water can be relaxed. However, the amount of contamination-causing substances may vary depending on the type of resin and other factors such as the amount of residual solvent during anode catalyst layer production. It is preferable to set based on the generation amount. Of course, the present invention does not limit the resin of the anode catalyst layer to be applied.

Further, the cathode catalyst layer is also significant when the cathode catalyst is composed of a layer dispersed in a resin, and in particular, the cathode catalyst is composed of a layer dispersed in polytetrafluoroethylene. The application significance is great. The reason for this is that when polytetrafluoroethylene adheres to the pollutant that has migrated from the anode, it inclines toward the hydrophilic side, and the internal pressure of the hydrogen bubbles is high due to the surface tension of the water, resulting in the hydrogen permeation into the anode chamber. This is because of the increase.

[Example 1]
The start-up process was performed using the electrolytic ozone device (M) shown in FIG.

Each member constituting the electrolytic cell for ozone generation (1) was as follows.

As a cation exchange membrane (10), a commercially available perfluorosulfonic acid type ion exchange membrane (manufactured by DuPont, trade name “Nafion 117”) is immersed in boiling pure water for 30 minutes and subjected to a swelling treatment with water. Was used.

As the anode current collector (22), a 2.6 mm thick titanium chatter fiber sintered body (manufactured by Tokyo Steel) was degreased and washed with a neutral detergent. Further, a platinum foil having a thickness of 0.2 μm and a porosity of 30% or more was placed on the titanium chatter fiber sintered body.

The anode catalyst layer (23) used was a sheet formed by dispersing lead dioxide powder (manufactured by Nacalai Tesque Co., Ltd.), which is an anode catalyst, in polyvinylidene difluoride. The sheet-like anode catalyst layer (23) was prepared by a lead dioxide powder and a resin solution in which polyvinylidene difluoride was dissolved in N-methyl-2-pyrrolidone (trade name “KF polymer # manufactured by Kureha Corporation”. 1120 ") was mixed to prepare a paste-like mixture, and this paste-like mixture was applied to a thickness of 100 µm on a glass plate and further dried.

As the cathode current collector (32), a 2.5 mm thick stainless steel fiber sintered body (manufactured by Tokyo Seizuna Co., Ltd.) was used.

As the cathode catalyst layer (33), a resin-based porous cathode catalyst sheet in which a platinum-supported carbon catalyst was dispersed in polytetrafluoroethylene was used. The cathode catalyst sheet was prepared by mixing a dispersion of polytetrafluoroethylene (PTFE) dispersion (trade name “31-J” manufactured by Mitsui Fluorochemical Co., Ltd.) and a platinum-supported carbon catalyst in water, and then drying. This was prepared by adding solvent naphtha and kneading, followed by a rolling process, a drying process, and a firing process. PTFE was 40% by mass, platinum-supported carbon catalyst was 60% by mass, film thickness was 120 μm, and porosity was 55%. is there.

As shown in FIG. 1, the anode side cell frame (11), the anode current collector (22) (with platinum foil), the anode catalyst layer (23), the cation exchange membrane (10), the cathode catalyst layer (33 ), the cathode current collector (32), the assembly arranged in the order of the cathode-side cell frame (12), is brought into close contact with each member by applying a pressing force from the outside by clamping means not shown, the electrolysis area 1 dm ² ozone A generating electrolysis cell (1) was assembled. This electrolytic cell (1) was incorporated in the electrolytic ozone generator (M) of FIG.

(Processing at startup)
In the electrolytic ozone generator (M), after filling the entire anolyte circulation line including the anode chamber (21) and the cathode chamber (31) of the electrolysis cell (1) with pure water, the following (1) to (1) The step shown in 6) was repeated, and the start-up process was performed by washing the anode chamber 12 times.

(1) Supply a direct current between the anode and cathode. Thereafter, it is assumed that the DC current is continuously supplied.

(2) In the first cleaning, the valve (47) is opened simultaneously with the start of DC current supply, and in the second and subsequent cleanings, the valve (47) is immediately opened to discharge 2/3 of the anolyte in the anode chamber. Drain from (46). Even after the anolyte is discharged, the anode catalyst layer (23) is immersed in the anolyte in the same state as when it is full. Further, it is assumed that the direct current is continuously supplied.

(3) Perform electrolysis for 3 minutes after discharging the anolyte.

(4) After electrolysis for 3 minutes, pure water is supplied from the pure water supply passage (44) to the anolyte circulation device (40), and pure water is supplied to the anode chamber (21) through the anolyte circulation line. To. That is, pure water was supplied in the same amount as the amount of anolyte discharged.

(5) Perform electrolysis for 2 minutes under full water condition.

(6) Return to (1) above.

(Electrolysis test)
After performing the above-described start-up process, an electrolytic test was subsequently performed as a full operation. In the electrolysis test, electrolysis was performed for 30 days at a current density of 2 A / cm ² and an electrolyte temperature of 30 ± 5 ° C. while naturally circulating the anolyte. Also, in response to the decrease in the anolyte accompanying the discharge of the catholyte from the cathode chamber (31), pure water is appropriately supplied from the pure water supply passage (44), and the pure water is supplied to the anode chamber (21) through the anolyte circulation line. Supplied.

During the electrolysis test, after 1 day from the start of electrolysis, after 10 days, after 30 days, cell voltage and ozone generation efficiency, hydrogen concentration in the anodic gas, F ion concentration in the anolyte, F ion concentration in the catholyte, The amount of water transferred was measured. The hydrogen concentration in the anodic gas, the F ion concentration in the anolyte, and the F ion concentration in the catholyte are the same as the gas and liquid separated by the anolyte gas-liquid separator (45) and the catholyte gas-liquid separator (50). It is the result of qualitative and quantitative analysis by an analyzer outside the figure. These measurement results are shown in Table 1 below.

Among the measurement items, F ions in the anolyte are decomposition products of polyvinylidene difluoride, which is a constituent material of the anode catalyst layer (23), and are substances that cause contamination of the cell. The F ions in the catholyte are the decomposition products transferred to the cathode, and are discharged out of the cell together with the cathode gas and the catholyte from the cathode chamber. The F ion concentration in the anolyte and catholyte is an indicator of the concentration of pollutant substances, and the higher the F ion concentration, the higher the concentration of pollutants in each electrode chamber. Contamination of the anode chamber causes a reduction in electrolytic performance. Further, contamination of the cathode chamber (31) causes the surface of the cathode catalyst layer to tilt toward the hydrophilic side and increase the permeation amount of hydrogen into the anode chamber. The amount of water transferred is the amount of water transferred from the anode to the cathode, and is expressed as H ₂ O (mol) / H ⁺ (mol).

[Example 2]
(Processing at startup)
A sheet-like anode catalyst layer (23) was produced in the same manner as in Example 1, and this anode catalyst layer (23) was immersed and washed with ozone water at room temperature for 1 hour using the washing device (60) shown in FIG. Went. Washing was performed by placing 100 ml of pure water and the anode catalyst layer (23) in an air diffusion bottle (61) and continuously supplying ozone gas having an ozone concentration of 198 to 205 g / Nm ³ into pure water for 1 hour. The ozone concentration in the ozone water during the immersion cleaning was 40 ppm. The ozone contact amount of the anode catalyst layer (23) calculated from the ozone gas supply amount is 8 g.

It was 1.0 mg / L when F ion concentration in ozone water was measured after immersion washing. The F ions are decomposition products of polyvinylidene difluoride, which is a constituent material of the anode catalyst layer (23), and are substances causing cell contamination. The F ion concentration in the ozone water indicates the amount of the pollutant that has eluted.

(Electrolysis test)
The electrolytic cell (1) was assembled using the anode catalyst layer (23) washed with ozone water, and this electrolytic cell (1) was incorporated into the electrolytic ozone generator (M) used in Example 1, and the same conditions as in the example 1 day, 10 days, 30 days after the start of electrolysis, cell voltage and ozone generation efficiency, hydrogen concentration in anodic gas, F ion concentration in anolyte, F ion in catholyte Concentration and amount of transferred water were measured. These measurement results are shown in Table 1 below.

[Example 3]
As the start-up process, the same process as in Example 2 was performed except that the immersion time of the anode catalyst layer (23) in ozone water was changed to 24 hours. In the starting process, the ozone contact amount of the anode catalyst layer (23) calculated from the ozone gas supply amount is 192 g. Moreover, it was 5.5 mg / L when F ion concentration in ozone water was measured after immersion washing.

The electrolysis test after the start-up treatment was carried out for 10 days under the same conditions as in Example 2. After 1 day and 10 days from the start of electrolysis, the cell voltage and ozone generation efficiency, the hydrogen concentration in the anode gas, the anode The F ion concentration in the liquid, the F ion concentration in the catholyte, and the amount of water transferred were measured. These measurement results are shown in Table 1 below.

[Comparative Example 1]
Only the electrolysis test was performed under the same conditions as in Example 1 without performing the start-up process, and after 1 day, 10 days, and 30 days from the start of electrolysis, the cell voltage and ozone generation efficiency, the hydrogen concentration in the anode gas The F ion concentration in the anolyte, the F ion concentration in the catholyte, and the amount of water transferred were measured. These measurement results are shown in Table 1 below.

From the results shown in Table 1, when Examples 1 to 3 that were subjected to the start-up process were compared with Comparative Example 1 that was not subjected to the start-up process, Examples 1 to 3 were found in the anolyte and catholyte in the electrolytic test. It was confirmed that the F ion concentration was low and the pollutant was removed by the start-up process. Further, in Examples 1 to 3, the hydrogen concentration in the anode gas was lower than that in Comparative Example 1, and the hydrophobicity of the cathode catalyst layer surface was maintained by removing the pollutant causing the amount of hydrogen permeation from the cathode to the anode. It was confirmed that it could be reduced. Since there is not much difference in the amount of water transferred between Examples 1 to 3 and the comparative example, even when the amount of water permeated from the anode to the cathode is about the same, the start-up treatment of Examples 1 to 3 is the hydrogen from the cathode to the anode. It shows that the amount of permeation is reliably reduced.

In the comparison between Example 2 and Example 3 in which the anode catalyst layer was subjected to immersion cleaning, when the cleaning time was lengthened, the amount of contamination-causing substances removed was increased and the cleaning effect was increased. In the anode gas after assembling the electrolytic cell, This indicates that the hydrogen concentration of can be maintained at a low concentration. Moreover, Example 3 which performed immersion washing for 24 hours showed ozone generation efficiency lower than Example 2 which performed immersion washing for 1 hour. This is presumably because a part of lead dioxide, which is an electrode catalyst, was reduced by immersion for a long time. From the comparison between the two, it is shown that the immersion cleaning time of the anode catalyst layer using lead dioxide is preferably 1 hour rather than 24 hours when importance is placed on the ozone generation efficiency.

[Example 4]
An anode catalyst layer (23) was produced from a resin different from that in Example 1.

The anode catalyst layer (23) was formed by dispersing lead dioxide powder (manufactured by Nacalai Tesque Co., Ltd.), which is an anode catalyst, into a THV copolymer and forming it into a sheet shape. The sheet-like anode catalyst layer (23) was prepared by dissolving a lead dioxide powder and a powdered THV copolymer (manufactured by Sumitomo 3M Limited, THV221AZ) in ethyl acetate to adjust the content ratio of the THV copolymer. A paste-like mixture was prepared by mixing with a resin solution prepared to 12% by mass, and this paste-like mixture was applied to a thickness of 100 μm on a glass plate and further dried. That is, the resin and solvent constituting the anode catalyst layer (23) are different from those in Example 1.

An ozone generating cell (1) is assembled with the same material as in Example 1 except that the resin of the anode catalyst layer (23) is changed, and this ozone generating cell (1) is incorporated into the electrolytic ozone generator (M). It is.

Then, the start-up process was performed by washing the anode chamber 12 times under the same conditions as in Example 1, and then an electrolytic test was performed under the same conditions as in Example 1 as actual operation. During this electrolysis test, as in Example 1, after 1 day from the start of electrolysis, after 10 days, after 30 days, cell voltage and ozone generation efficiency, hydrogen concentration in the anode gas, F ion concentration in the anolyte, cathode The F ion concentration in the liquid and the amount of transferred water were measured. These measurement results are also shown in Table 1.

F ions detected in the anolyte and in the catholyte are decomposition products of vinylidene difluoride constituting the THV copolymer that is a constituent material of the anode catalyst layer (23), and the resin is dissolved by electrolysis. Indicates that it occurred. However, since the ozone generation efficiency is stable and the hydrogen concentration in the anode gas is stable at a low concentration, it is considered that the decomposition product removal effect of the THV copolymer by the start-up treatment was obtained. Further, in comparison between Example 1 and Example 4 in which the same number of times of anode chamber cleaning was performed, Example 4 had a lower F ion concentration than Example 1 throughout the electrolytic test. This is because the THV copolymer has higher ozone resistance and less decomposition products than polyvinylidene difluoride, so the residual amount after the same number of washings is small and occurs over time. This is probably because there were also few decomposition products.

This application is accompanied by the priority claim of Japanese Patent Application No. 2011-75351 filed on March 30, 2011, the disclosure of which constitutes part of the present application as it is. .

The terms and expressions used herein are for illustrative purposes and are not to be construed as limiting, but represent any equivalent of the features shown and described herein. It should be recognized that various modifications within the claimed scope of the present invention are permissible.

The starting method of the electrolysis cell for ozone generation of the present invention can be widely used as a starting method of the electrolysis cell for ozone generation of the zero gap method.

M ... Electrolytic ozone generator
1 ... Electrolytic cell
10 ... Cation exchange membrane
20 ... Anode
21 ... Anode chamber
22 ... Anode current collector or anode substrate
23… Anode catalyst layer
24 ... Anolyte supply port (pure water supply means)
25 ... Anolyte / gas outlet
26 ... Anolyte discharge port (Anolyte discharge means)
30 ... Cathode
31 ... Cathode chamber
32 ... Cathode current collector or cathode substrate
33 ... Cathode catalyst layer
35 ... Cathode / Gas outlet
40 ... Anolyte circulation device (pure water supply means)
41 ... 1st conduit
42 ... Second conduit (pure water supply means)
44 ... Pure water supply channel (pure water supply means)
45 ... Anolyte gas-liquid separator
46 ... Drain conduit (Anolyte discharge means)
47… Valve (Anolyte discharge means)
50 ... Catholyte gas-liquid separator
60 ... Cleaning equipment

Claims

An anode chamber and a cathode chamber are formed by providing an anode and a cathode on both sides of a fluororesin cation exchange membrane, and pure water supplied to the anode chamber is electrolyzed by supplying a direct current between the anode and the cathode. In the electrolytic cell for ozone generation in which ozone is generated from the anode and hydrogen is generated from the cathode, the anode is cleaned as a start-up process.
2. The start-up electrolysis cell for ozone generation according to claim 1, wherein as the start-up process, the anode chamber is cleaned at least once by supplying a direct current between the anode and the cathode and then discharging the anolyte and supplying pure water. Method.
The discharge method of the electrolytic cell for ozone generation according to claim 2, wherein the discharge of the anolyte is performed while maintaining the state in which the anodic catalyst is immersed in the anolyte.
The method for starting an electrolytic cell for ozone generation according to claim 1, wherein as the start-up treatment, the anode is washed with ozone water before assembling the electrolytic cell, and the electrolytic cell is assembled using the cleaned anode.
The method for starting an electrolysis cell for ozone generation according to any one of claims 1 to 4, wherein the anode catalyst layer of the anode is composed of a layer in which the anode catalyst is dispersed in polyvinylidene difluoride.
The method for starting an electrolysis cell for ozone generation according to any one of claims 1 to 4, wherein the cathode catalyst layer of the cathode is composed of a layer in which the cathode catalyst is dispersed in polytetrafluoroethylene.
The anode catalyst layer of the anode is composed of a layer in which the anode catalyst is dispersed in polyvinylidene difluoride, and the cathode catalyst layer of the cathode is composed of a layer in which the cathode catalyst is dispersed in polytetrafluoroethylene. Item 5. A starting method for an electrolytic cell for ozone generation according to any one of Items 1 to 4.
An anode chamber and a cathode chamber are formed by providing an anode and a cathode on both sides of a fluororesin-based cation exchange membrane, and the pure water supplied to the anode chamber is electrolyzed by applying a DC voltage between the anode and the cathode. An ozone generating electrolysis cell that generates ozone from the anode and generates hydrogen from the cathode;
An anolyte discharging means for discharging the anolyte from the anode chamber of the electrolysis cell without recirculation;
An electrolytic ozone generator comprising: pure water supply means for supplying pure water to the anode chamber of the electrolytic cell.
An anode chamber and a cathode chamber are formed by providing an anode and a cathode on both sides of a fluororesin cation exchange membrane, and pure water supplied to the anode chamber is electrolyzed by supplying a direct current between the anode and the cathode. In the electrolytic cell for ozone generation that generates ozone from the anode and generates hydrogen from the cathode,
An electrolytic cell for generating ozone, wherein the anode is washed with ozone water before assembling the electrolytic cell.
An electrolysis ozone generator comprising the electrolysis cell for ozone generation according to claim 9.