JPH11128940A - Device and method for electrolysis of water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently prepare acidic or alkaline water with a simple device. SOLUTION: A device for electrolysis of water comprises a storage 10 containing an aqueous solution of an electrolyte, an electrode 7 installed in the storage 10, and an electrolytic cell (a) arranged so that the aqueous solution of an electrolyte is come into contact with an outer wall, wherein all or a part of the wall side of the electrolytic cell (a) is composed of an electrode plate 3 formed by accumulating a sheet-like diaphragm 5, a sheet-like nonconductive material 8 having a number of holes 9, and a sheet-like electrode 4 having a number of holes 6 successively from outside, and holes of the nonconductive material 8 and the electrode plate 3 are penetrated. The diaphragm 5 may be a negative or positive ion-exchange membrane. The nonconductive material 8 may be omitted. Water to be electrolyzed is fed into the electrolytic cell (a), and direct current is applied to the electrodes 4 and 7 to electrolyze the water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an electrolysis
The present invention relates to a water electrolyzer for producing acidic water or alkaline water having strong sterilizing power or weak alkaline water suitable for beverages, and a method for electrolyzing water using the water electrolyzer.

[0002]

2. Description of the Related Art In recent years, strongly acidic water having a high oxidation-reduction potential obtained by electrolysis of water and water having a strongly alkaline and low oxidation-reduction potential have a strong bactericidal effect against Escherichia coli and the like. Has attracted much attention. In addition, weakly alkaline water is commercially available as alkaline ionized water suitable for beverages because it is delicious to drink and does not contain active oxygen. Conventionally, such water has been produced by electrolyzing water using a water electrolyzer having a structure in which a diaphragm is arranged between a cathode and an electrode serving as an anode. When electrolyzing water using this water electrolyzer, when trying to obtain acidic or alkaline water, by the principle of electrolysis,
Water with the opposite property to the purpose will also be produced. That is, to obtain acidic water, alkaline water is produced at the same time, and vice versa.

[0003] The structure of the electrolytic cell in the conventional method is a method in which two chambers are provided with a diaphragm, and electrodes are installed in each of the chambers. In the opposite room, water of opposite quality, for example alkaline water, is produced. Furthermore, in the conventional method, when the electrolyte is added during the electrolysis, the electrolyte is added to the raw water supplied to the electrolytic cell. It is necessary to make the target water, such as acidic water, and the non-target water, such as alkali, almost the same, and the production amounts of the respective waters become almost the same. Therefore, the design of the electrolytic cell requires a volume of the electrolytic cell more than twice as much as the target water, and a water circulation device other than the target is required, which complicates the structure and increases the manufacturing cost. There is a problem in that unnecessary water is drained, or extra work is required for taking measures to utilize the water.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a water electrolysis apparatus capable of efficiently producing only water having desired properties, for example, acidic water or alkaline water, with a simple apparatus. And a water electrolysis method.

[0005]

Means for Solving the Problems In order to achieve the above object, the present inventor changed the pH and oxidation-reduction potential by electrolyzing water to obtain water which is acidic and has a positive oxidation-reduction potential. As a result of various investigations on an apparatus for producing water having an alkaline and redox potential which is negative, unlike the conventional method of producing an approximately equal amount of acidic or alkaline water by dividing the electrolytic cell with a diaphragm and electrolyzing it, Electrolysis of water in the electrolytic cell using an electrolytic cell equipped with an electrode and a diaphragm and an electrolytic aqueous solution in contact with the electrode and an electrode disposed in the electrolytic aqueous solution, so that only water having desired properties can be obtained. The present inventors have found that it can be manufactured while the electrolyte is present in the aqueous electrolyte solution, and have completed the present invention.

That is, the present invention provides a water electrolysis apparatus comprising a storage tank containing an aqueous electrolyte solution, an electrode arranged in the storage tank, and an electrolytic tank arranged so that the electrolyte solution in the storage tank is in contact with an outer wall. In the electrolytic cell, all or a part of the wall surface is formed of an electrode plate, and the electrode plate is an electrode plate in which a sheet-shaped diaphragm and a sheet-shaped electrode having a large number of holes are sequentially stacked from the outside. [Claim 1]. A storage tank containing an aqueous electrolyte solution,
A water electrolysis apparatus comprising an electrode disposed in the storage tank and an electrolytic tank disposed so that an outer surface of the aqueous solution is in contact with the electrolyte aqueous solution in the storage tank. This electrode plate is an electrode plate in which a sheet-shaped diaphragm, a sheet-shaped non-conductive material having a large number of holes, and a sheet-shaped electrode having a large number of holes are laminated in order from the outside, and The water electrolysis apparatus is characterized in that the material and the hole of the electrode plate are penetrated [Claim 2]. The present invention also relates to a water electrolyzer, wherein the above-mentioned diaphragm is an anion exchange membrane [Claim 3]. The present invention also relates to a water electrolyzer, wherein the above-mentioned diaphragm is a cation exchange membrane [Claim 4]. Further, two or more electrolytic cells may be arranged in the storage tank.

Further, according to the present invention, water to be electrolyzed is passed through the electrolytic cell of the water electrolyzer according to claim 1 or 2, and the water is supplied to the electrode of the electrode plate constituting the electrolytic cell and the storage tank. A water electrolysis method is characterized in that a DC voltage is applied to the arranged electrodes and a current is applied [Claim 5]. The present invention also provides
The water to be electrolyzed is passed through the electrolytic cell of the water electrolyzer according to claim 3, the electrode of an electrode plate constituting the electrolytic cell is used as an anode, and the electrode arranged in the storage tank is used as a cathode. A water electrolysis method characterized in that a voltage is impressed and a current is passed [Claim 6]. Further, according to the present invention, water to be electrolyzed is passed through the electrolytic cell of the water electrolyzer according to claim 4 described above, and the electrode of the electrode plate constituting the electrolytic cell is used as a cathode and disposed in the storage tank. A water electrolysis method characterized in that a direct current voltage is applied and an electric current is applied using the electrode as an anode [Claim 7].

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the first and second aspects of the present invention will be described. FIG. 1A is a schematic view of an example of the electrolytic cell of the water electrolyzer according to the first aspect of the present invention. Reference numeral 10 denotes a storage tank containing an aqueous electrolyte solution 11. a is an electrolytic cell, and 3 is an electrode plate constituting a part of the electrolytic cell. FIG.
(B) is a partially enlarged sectional view of the electrode plate 3.
The electrode 3 is a laminate of a sheet-like diaphragm 5, a sheet-like non-conductive material 8 having many holes 9, and a sheet-like electrode 4 having many holes 6. 7 is an electrode. The electrolytic cell a and the electrode 7 are arranged in a storage tank 10 filled with an aqueous electrolyte solution 11. Therefore, the electrolytic cell a
Is in contact with the aqueous electrolyte solution. Electrolytic cell a
The inside is filled with water 12 to be electrolyzed. The water to be electrolyzed in the electrolytic cell a may be of a batch type,
It is preferable to supply water continuously and to continuously discharge the water. In this example, the water 12 enters through the inlet 15, is electrolyzed, and is discharged through the outlet 16, so that acidic water and alkaline water having desired properties can be continuously obtained. The electrode 7 may be rod-shaped or plate-shaped. Further, the electrode 7 may be formed in a sheet shape and arranged outside the diaphragm along the diaphragm. Two or more electrolytic cells a may be provided in the storage tank.

FIG. 2 is a sectional view of the electrolytic cell a. This electrolytic cell a is cylindrical. 1 is one end of the electrolytic cell a, 2
Is the other end of the electrolytic cell a, and these portions 1 and 2 are preferably made of synthetic resin. Reference numeral 3 denotes an electrode plate forming a wall surface of an intermediate portion of the electrolytic cell a. This electrode plate 3 is a laminate in which a sheet-like diaphragm 5, a sheet-like non-conductive material 8 having a large number of holes 9, and a sheet-like electrode 4 having a large number of holes 6 are laminated in this order from the outside. It is. The electrode plate 3 is adhered and fixed to one end 1 and the other end 2 of the electrolytic cell a so as to be integrated, and the integral constitutes the electrolytic cell a. In the above-mentioned electrode plate 3, the sheet-shaped non-conductive material 8 having many holes 9 can be omitted (claim 1 invention). Sheet-shaped non-conductive material 8 having many holes 9 and many holes 6
The holes of the sheet-like electrode 4 having the holes are made substantially coincident with each other so as to form through holes. FIG. 2B is an enlarged perspective view of a part of the electrode plate 3.

In the present invention, water is electrolyzed in the electrolytic cell a. Since the water 12 to be electrolyzed is raw water to which no electrolyte is added, the electric conductivity of the water is low.
Therefore, it is necessary to shorten the distance between the diaphragm 5 and the electrode 4 for efficient electrolysis. Therefore, in the present invention, an electrode plate of a type in which the diaphragm 5 and the electrode 4 are laminated, a number of holes 6 are formed in the electrode 4, and electrons and ions are moved through the holes 6 is adopted.

The sheet-like electrode 4 constituting the electrode plate 3 is
The sheet-shaped conductive material is, for example, a plate made of copper, lead, nickel, chromium, titanium, tantalum, gold, platinum, iron oxide, stainless steel, carbon fiber, graphite, or the like. The thickness of the sheet electrode is 0.01 to 5 mm, but 0.01 to 5 mm.
It is preferable that a titanium plate of about 5 mm is plated with a white metal. A large number of through holes 6 are formed in the sheet-like electrode. It is appropriate that the diameter of the hole is 1 to 10 mm and the aperture ratio is 30 to 70%. In addition, the sheet-like electrode knits the linear material of the conductive material into a net shape,
It may be woven. Further, a linear material made of a conductive material may be wound around the frame in an interdigital shape.

The sheet-like diaphragm 5 constituting the electrode plate 3 is
Non-woven fabrics such as polyvinyl fluoride fiber, asbestos, glass wool, polyvinyl chloride fiber, polyvinylidene chloride fiber, polyester fiber, and aromatic polyamide fiber are usually used as the diaphragm. For example, non-woven fabric such as polyester fiber, nylon fiber or polyethylene fiber or polyethylene screen is used for the aggregate, and chlorinated polyethylene, polyvinyl chloride or polyvinylidene fluoride or a mixture of these materials is used for the film material. The used diaphragm can also be preferably used. A semipermeable membrane such as cellophane, or a cation exchange resin membrane or an anion exchange resin membrane can also be used as a special membrane. In addition, by using various combinations such as a semi-permeable membrane and a non-woven membrane, a semi-permeable membrane and an ion exchange membrane, or an ion-exchange membrane and a non-woven membrane, the strength can be increased, and acid, alkali, Corrosion resistance against the gas generated, or change the permeability of the diaphragm.

The sheet-shaped non-conductive material 8 is made of synthetic resin such as ABS resin, acrylic resin, epoxy resin, polyurethane resin, polyethylene resin, polypropylene resin, nylon resin, polyethylene terephthalate resin, polyamide resin, vinyl chloride resin, etc. Alternatively, it is a sheet made of an elastomer such as natural rubber, SBR, or chloroprene rubber. The thickness of the sheet-shaped non-conductive material is 0.01 to
3 mm is preferred. The diameter of the hole is preferably 1 to 10 mm, and the aperture ratio is preferably 30 to 70%. It is preferable that the holes of the sheet-like electrode and the holes of the sheet-like non-conductive material have the same size and arrangement so that the holes overlap each other, so that there is at least a portion penetrating both. One side of the sheet electrode 4 (the surface in contact with the diaphragm)
It may be a coating layer formed by coating on the substrate. in this case,
The non-conductive material is heated and melted, dissolved in a solvent, or dispersed, or powdered to form a sheet-like electrode 4,
The coating film layer may be formed by coating so that the hole 6 formed in the sheet-like electrode 4 is not closed. When water is electrolyzed, a gas such as oxygen, hydrogen, or chlorine generated by the electrolysis foams and closes the hole 6 of the electrode 4 to reduce the electric current. In particular, when an ion-exchange membrane or a semipermeable membrane is used for the diaphragm, it is necessary to take measures to prevent the membrane from deteriorating. However, providing a sheet-shaped non-conductive material can reduce these problems.

In the present invention, the shape of the electrolytic cell a may be a cylindrical shape, a rectangular cross-sectional shape or a cylindrical cross-sectional shape having a star shape. The electrolytic cell a is formed by laminating a sheet-like diaphragm 5 and a sheet-like electrode 4 having a large number of holes 6 formed therein, or a sheet-like non-membrane having a sheet-like diaphragm 5 and a large number of holes 9 formed therein. The conductive material 8 and the sheet-like electrode 4 having a large number of holes 6 are laminated to form a sheet-like electrode plate 3 in advance, and this electrode plate 3 is connected to both ends 1 and 2 of the electrolytic cell a. Attach to create. The sheet-like electrode 4 having a sheet-like diaphragm 5 and a number of holes 6 is sequentially attached to both ends 1 and 2 of the electrolytic cell a, or the sheet-like diaphragm 5 and a number of holes 9 are formed. The sheet-shaped electrode 4 having the sheet-shaped non-conductive material 8 and a large number of holes 6 formed therein may be sequentially attached to both ends 1 and 2 of the electrolytic cell a. Since the electric conductivity of water is low, the distance between the sheet-like electrode 4 and the sheet-like diaphragm 5 is preferably as short as possible in order to flow a current necessary for electrolysis at a low voltage. It is preferable to use a structure in which the sheet-like diaphragm 5 and the sheet-like electrode 4 are stacked and arranged, or a structure in which the sheet-like diaphragm 5 and the sheet-like non-conductive material and the sheet-like electrode 4 are stacked and arranged. Further, the two ends 1 and 2 of the electrolytic cell a are not necessarily separated independently from each other, but may be partially connected.

The electrode 7 disposed outside the electrolytic cell a in the aqueous electrolyte solution 11 of the present invention is made of, for example, copper, lead, nickel, chromium, titanium, tantalum, gold, platinum, iron oxide, stainless steel, carbon fiber, graphite, or the like. May be used, or those obtained by plating them with a white metal may be used.

In the present invention, the water to be electrolyzed includes tap water, industrial water, river water, seawater, rainwater, pure water, ultrapure water and the like. In addition, sodium chloride and potassium chloride are generally used as the electrolyte, but other metal salts such as silver nitrate and magnesium chloride and alkaline substances such as sodium hydroxide, potassium hydroxide and ammonia are also used. , Carbonic acid, nitric acid,
Acidic substances such as boric acid, phosphoric acid, acetic acid, lactic acid, oxalic acid and tartaric acid, and salts thereof such as sodium salt, potassium salt and calcium salt are also used. Further, an acidic substance and a salt such as hydrochloric acid and sodium chloride or sodium hydroxide and sodium chloride, or an alkaline substance and a salt may be combined. The concentration of the aqueous electrolyte solution is made high. That is, the concentration is set to 0.1% by weight or more. The upper limit of the concentration is a range in which the aqueous electrolyte solution can maintain fluidity. Then, by performing the electrolysis, the concentration of the electrolyte decreases with time, and the electrolysis efficiency decreases. Therefore, the electrolyte is replenished or the electrolyte aqueous solution is replaced. Therefore, the larger the storage tank for storing the electrolyte aqueous solution and the higher the electrolyte concentration of the electrolyte aqueous solution to increase the storage amount of the electrolyte, the longer the electrolysis can be performed for a longer time, and the desired water can be obtained. it can.

A method for electrolyzing water using the water electrolyzer shown in FIGS. 1 and 2 will be described. Here, the case where a sodium chloride aqueous solution is used as the electrolyte aqueous solution will be described. The electrode 4 of the electrode plate 3 constituting the wall surface of the electrolytic cell a is used as an anode, for example, and the electrode 7 is used as a cathode, for example. When electrolysis is performed, ions in the aqueous solution move in proportion to the amount of electric current according to the unique transport number of each ion. In the above example, when the electrode 4 constituting the inner wall of the electrolytic cell a is an anode and the electrode 7 disposed outside the electrolytic cell a is a cathode, the storage tank 1
The anion, i.e., chloride ion, contained in the sodium chloride in 0 is attracted by the electrode 4 to move into the electrolytic cell a, and the cation, i.e., the sodium ion, in the storage tank 10 in which the electrode 7 is disposed. The force to stay in the work. Then, oxygen gas and chlorine gas are generated on the anode surface in the electrolytic cell a, the hydrogen ion concentration of the water in the electrolytic cell a increases, the pH decreases, the acid becomes acidic, and the oxidation-reduction potential increases. Thus, the water 1 to be electrolyzed
2 is introduced and the electrolyzed water is drained from outlet 16. In this manner, acidic water having a high oxidation-reduction potential generated by electrolysis can be continuously taken out. The opposite phenomenon occurs when the electrode 4 inside the electrolytic cell a is a cathode and the electrode 7 disposed outside the electrolytic cell a is an anode. Further, since there is a difference in electrolyte concentration between the electrolytic cell a and the storage tank 10, a force for maintaining the concentration gradient at an equilibrium also acts.

However, when a normal diaphragm is used as the diaphragm, the concentration of sodium chloride in the storage tank 10 and the concentration of the electrolytic cell a
The sodium chloride in the storage tank 10 elutes into the water in the electrolytic cell a due to the diffusion phenomenon due to the difference with the sodium chloride concentration in the medium. Therefore, the concentration of sodium chloride in the electrolytic cell a increases. In the case where the purpose of use does not cause any inconvenience even when the concentration of the electrolyte in the electrolytic cell a is high as described above, or when there is no problem even if the consumption of the electrolyte is large, an ordinary diaphragm can be used.

When the electrode 4 on the inner wall of the electrolytic cell a is used as an anode and the electrode 7 outside the electrolytic cell a is used as a cathode, electrolysis is performed in proportion to the amount of current at the time of electrolysis. Anions, ie, chloride ions, contained in the sodium chloride move from the storage tank 10 to the electrolytic cell a. In the storage tank 10, chloride ions decrease and hydroxyl ions increase by electrolysis, and alkaline substances such as sodium hydroxide increase. While chloride ions are present, it is possible to produce acidic water having a high oxidation-reduction potential by electrolysis.
When the chlorine ions become insufficient, the current carrying ions become insufficient, so that the current becomes difficult to flow. In that case, sodium chloride is replenished in the storage tank 10, or the sodium chloride in the storage tank 10 is replaced with a new one. Further, when an electrolyte to which an acidic substance such as hydrochloric acid is added in advance is used, the hydroxide ions to be purified by electrolysis are neutralized by the acid and the storage tank 1
The inside of 0 can be kept acidic. When the inside of the storage tank is kept acidic, there is an advantage that it is easy to produce acidic water from the water in the electrolytic tank and that the scale is less likely to adhere to the electrode. Further, deterioration of the ion exchange membrane due to hydroxyl ions can be prevented. In the present invention, by increasing the storage tank 10 and increasing the electrolyte concentration of the electrolyte aqueous solution, the electrolysis can be continued for a long time without replenishment or replacement of sodium chloride. Conversely, when performing electrolysis using the electrode 4 on the inner wall of the electrolytic cell a as a cathode and the electrode 7 outside the electrolytic cell a as an anode, the concentration of the alkaline substance in the electrolytic cell a increases. .

In the water electrolysis apparatus of the present invention, when an ion exchange membrane is used as the sheet-like diaphragm 5, only specific ions among the ions contained in the electrolyte can be selectively passed through the ion exchange membrane. Therefore, production of desired water is facilitated. First, an example in which an anion exchange membrane is used as a diaphragm will be described. For example, in FIGS. 1 and 2,
The electrode plate 3 is formed using an anion exchange membrane as the diaphragm 5. An electrolytic cell a is formed using the electrode plate 3, and water to be electrolyzed is passed through the electrolytic cell a. This storage tank 1
0 is filled with an aqueous solution of sodium chloride as an aqueous electrolyte solution. Further, the electrode 7 is inserted into the storage tank 10. Next, a direct current is applied to use the sheet electrode 4 of the electrode plate 3 of the electrolytic cell a as an anode and the electrode 7 in the storage tank as a cathode to perform electrolysis. In this case, oxygen gas, chlorine gas and hydrogen ions are generated on the anode surface, and hydrogen gas and hydroxyl ions are generated on the cathode surface. Anions such as chloride ions contained in the water in the storage tank 10 are electrolyzed together with the anion exchange membrane 5.
, And moves into the electrolytic cell a, but the sodium ion of the cation cannot permeate and remains in the storage tank 10. As a result, the water 12 in the electrolytic cell a becomes acidic, the oxidation-reduction potential value increases, and when electrolysis is sufficiently performed, the pH value exhibits a strong acidity with a low pH value, a high positive oxidation-reduction potential, and a sodium ion Is obtained. Also,
According to this method, sodium chloride is not eluted from the electrolytic cell a, so that consumption of sodium chloride can be suppressed. When hydrochloric acid or a mixture of sodium chloride and hydrochloric acid is used as the electrolyte, water having a low pH and a strong acidity and a high redox potential is easily removed from the water in the electrolytic cell a while keeping the storage tank 10 acidic. Can be manufactured.

When the pH value is 2.7 or less and the oxidation-reduction potential is 1
Water exhibiting 000 mV or more is, for example, pathogenic E. coli "O-157", resistant bacterium "MRSA", "Legionella bacterium" causing infectious disease, pathogenic microorganism "Cryptosporidium" which is a problem of tap water contamination. , Powdery mildew, harmful to plants, Rhizoctonia causing turf disease
It is known to have an effective bactericidal effect against many bacteria and viruses, and is used as a disinfectant for agriculture and livestock, as a disinfectant for medical use, or as a therapeutic agent for skin diseases. Is done.

Next, an example in which a cation exchange membrane is used as a diaphragm will be described. For example, in FIGS.
The electrode plate 3 is prepared using a cation exchange membrane as a method.
An electrolytic cell a is formed using the electrode plate 3, and water to be electrolyzed is passed through the electrolytic cell a. The storage tank 10 is filled with an aqueous sodium chloride solution as an aqueous electrolyte solution. The electrode 7 is inserted into the storage tank 10. Next, a DC current is passed through the sheet electrode 4 of the electrode plate 3 of the electrolytic tank a as a cathode and the electrode 7 in the storage tank as an anode to perform electrolysis. In this case, oxygen gas, chlorine gas and hydrogen ions are generated on the anode surface,
Hydrogen gas and hydroxyl ions are generated on the cathode surface. Storage tank 1
The sodium ions in 0 permeate the cation exchange membrane 5 with the electrolysis and move to the electrolytic cell a side, but do not transmit anions such as chloride ions and remain in the storage tank 10. As a result, the water 12 in the electrolytic cell a becomes alkaline, and the oxidation-reduction potential decreases. When the electrolysis is sufficiently performed, water having a high alkaline value at a pH value and a low negative oxidation-reduction potential is produced.

When the pH value is 11 or more and the oxidation-reduction potential is -80
It is known that water exhibiting 0 mV or less has a strong reducing power and exhibits a certain bactericidal effect against bacteria and viruses, and there have been reports of examples of water being used for sterilizing vegetables and the like. In addition, weakly alkaline water having a pH value of 8 to 10 is
It is commercially available as alkaline ionized water and delicious drinking water. In recent studies, alkaline ionized water has attracted attention as a health-free water that does not contain active oxygen, which is one of the causes of cancer. Furthermore, when using calcium lactate containing calcium as an electrolyte,
Calcium ions are eluted into alkaline ionized water, and water containing a large amount of calcium necessary for the formation of human bones can be produced.

FIG. 3 (a) is a schematic view showing another embodiment of the water electrolysis apparatus of the present invention, and FIG. 3 (b) is an enlarged sectional view of a part of the electrode plate. . In FIG. 3A, a storage tank 10 is filled with an aqueous electrolyte solution 11. Reference symbol a denotes a box-shaped electrolytic cell, which is connected to a hole formed in a part of the wall of the storage tank 10. This connection surface is separated by the electrode plate 3. The electrode plate 3 has the configuration shown in FIG. 3B, and has a sheet-shaped diaphragm 5, a sheet-shaped non-conductive material 8 having a large number of holes 9, and a sheet provided with a large number of holes 6. It is a laminate of the electrode 4 in a shape. The electrode 4 is located on the side of the electrolytic cell a, so that the portion of the diaphragm 5 on the outer wall of the electrolytic cell a is in contact with the aqueous electrolyte solution 11 in the storage tank 10. Reference numeral 7 denotes an electrode disposed outside the electrolytic cell a, which is disposed in the storage tank 10. Electrolysis is performed by passing a direct current between the electrode 4 in the electrolytic cell a and the electrode 7 in the storage tank 10. At the same time, water 1 to be electrolyzed from inlet 17 of electrolytic cell a
2 is introduced. The water 12 is electrolyzed into acidic water or alkaline water. The electrolyzed water is continuously withdrawn from the outlet 18 and used for a predetermined application. Also in this embodiment, an anion exchange membrane or a cation exchange membrane can be used as the diaphragm 5. Two or more electrolytic cells a may be provided.

FIG. 4A is a schematic view showing another embodiment of the water electrolysis apparatus of the present invention, and FIG. 4B is a partially enlarged sectional view of the electrode plate. 10 is a storage tank. This storage tank 10 is filled with an electrolyte solution 11. Reference symbol a denotes an electrolytic cell in the shape of a cylindrical container inserted into the electrolyte aqueous solution 11, a part of which is constituted by the electrode plate 3. The electrode plate 3 has a configuration shown in FIG. 7
Is an electrode disposed outside the electrolytic cell a, and is disposed in the storage tank 10. Electrolysis is performed by passing a direct current between the electrode 4 in the electrolytic cell a and the electrode 7 in the storage tank 10. Electrolytic cell a
The inside is filled with water 12 to be electrolyzed. The water to be electrolyzed in the electrolytic cell a is supplied in a batch manner,
The water 12 to be electrolyzed may be discharged,
, And may be of a water-flow type that is discharged from the discharge pipe 14. Electrode 4 of electrode plate 3 constituting the wall of electrolytic cell a
Is used as an anode, and the electrode 7 is used as a cathode, for example, and a DC voltage is applied and a current flows to perform water electrolysis. At the same time, water 12 to be electrolyzed flows from the introduction pipe 13 of the electrolytic cell a into the electrolytic cell a. The water 12 is electrolyzed into acidic water or alkaline water. The electrolyzed water is supplied to the discharge pipe 1
4. Take out continuously from 4 and use it for a predetermined purpose. Also in this embodiment, an anion exchange membrane or a cation exchange membrane can be used as the diaphragm 5. The electrolytic cell a is 2
More than one may be provided.

In each of the above embodiments, the electrode disposed outside the electrolytic cell a is disposed apart from the electrolytic cell a. However, the electrode disposed outside the electrolytic cell a is replaced with an electrode plate constituting the electrolytic cell a. It may be incorporated in FIG. 5 is a cross-sectional view showing one example thereof, and shows an electrolytic cell used in a water splitting apparatus having the same configuration as that shown in FIG. a is an electrolytic cell in the shape of a cylindrical container. 19 is the bottom of the electrolytic cell a, and 20 is the upper part of the electrolytic cell a. Reference numeral 3 denotes an electrode plate forming a wall surface of an intermediate portion of the electrolytic cell a. The electrode plate 3 has a large number of holes 6 in order from the inside.
A sheet-like electrode 4 having a plurality of holes 9 formed therein, a sheet-shaped non-conductive material 8 having a plurality of holes 9 formed therein, a sheet-shaped diaphragm 5 and a sheet-shaped non-conductive material 22 having a plurality of holes 24 formed therein. It is a laminate with a sheet-like electrode 21 having a number of holes 23 formed therein.
The sheet-like electrode 21 having the outermost holes 23 formed therein functions as the electrode 7 in each of the above-described embodiments. Therefore, if the above-mentioned electrode plate is used, it is not necessary to arrange the electrode 7 in each of the above-mentioned modes. The sheet-like electrode 21 having a large number of holes may be the same as the sheet-like electrode 4 having a large number of holes. Note that one or both of the non-conductive materials provided with the large number of holes may be omitted. This electrode plate is disclosed in JP-A-8-276.
No. 184, Japanese Patent Application No. 9-6322. When this electrode plate is used, the distance between the electrode and the diaphragm becomes extremely narrow, and no gas is generated between the electrode and the diaphragm at the time of electrolysis, so that bubbles do not obstruct the current, which is very convenient. good.

In each of the above embodiments, the storage tank 10 may be enlarged, and two or more electrolytic cells a may be arranged in the storage tank. At this time, when the plurality of electrolytic cells a disposed in the storage tank 10 are electrolytic cells for obtaining the same type of water, that is, when both electrolytic cells for obtaining acidic water or both for obtaining alkaline water, the electrode 7 may be shared or may be separately provided to increase the number of electrodes. On the other hand, for example, 2
When one electrolytic cell is arranged and one electrolytic cell is to obtain acidic water and the other electrolytic cell is to obtain alkaline water, the electrode of one electrolytic cell is used as the anode and the electrode of the other electrolytic cell is used as the anode. Is a cathode, the electrode 7 is not required. FIG. 6 is a schematic view of an example of the water electrolysis apparatus. An electrolytic bath a and an electrolytic bath a ′ are arranged in a storage tank 10 filled with an aqueous electrolyte solution. The electrolytic cell a and the electrolytic cell a 'have the same structure, and both have the same structure as that shown in FIG. In the electrolytic cell a, water 12 to be electrolyzed enters through an inlet pipe 13, is electrolyzed, and is discharged from a discharge pipe 14. In the electrolytic cell a ', the water 12 to be electrolyzed enters through an inlet pipe 13', is electrolyzed, and is discharged from an outlet pipe 14 '. Then, a direct current is flowed using the electrode 4 of the electrolytic cell a as an anode and the electrode 4 'of the electrolytic cell a' as a cathode. Electrolysis is performed in each electrolytic cell, and acidic water is taken out from the discharge pipe 14 of the electrolytic cell a, while alkaline water is taken out from the discharge pipe 14 'of the electrolytic cell a'.

[0028]

【Example】

Example 1 An example using the water electrolysis apparatus shown in FIG. 3 will be described.
A 14 cm long, 6 cm wide hole is opened in one side of the plastic storage tank 10 having a length of 30 cm, a width of 22 cm, and a height of 22 cm, and a box-shaped electrolytic cell a having a length of 15 cm, a width of 7 cm, and a depth of 3 cm is formed therein. Attached. The storage tank 10 and the electrolytic cell a were separated by the electrode plate 3. When this partition is made, the electrode 4 of the electrode plate 3
Are located on the side of the electrolytic cell a, and the diaphragm 5 is located on the side of the storage tank. The electrode plate 3 was prepared as follows. That is, a hole having a diameter of 1.5 mm was formed almost all over a titanium plate having a length of 14 cm, a width of 6 cm and a thickness of 0.1 mm.
The aperture ratio at this time was 51%. Platinum plating of 0.7 μm thickness is applied to the titanium plate having a large number of holes 6 to form an electrode 4, and a non-conductive polyvinyl chloride resin layer is formed on the side of the electrode 4 which contacts the diaphragm 5. 8 was provided by painting. At the time of this coating, the holes formed in the titanium plate were not closed. As the diaphragm 5, a sheet-like anion exchange membrane ("A-501" manufactured by Asahi Kasei Corporation) was used. The electrode plate 3 was formed by laminating the electrode 4 provided with the polyvinyl chloride layer 8 and the diaphragm.

The storage tank 10 was filled with a high-concentration sodium chloride aqueous solution having a concentration of 3% by weight or more, and a stainless steel electrode 7 was disposed therein. Tap water from the inlet of electrolytic cell a (pH 7.79, oxidation-reduction potential (ORP) 640 mV)
Was flowed in at a rate of 900 cc / min and discharged from the outlet 18. Then, a DC voltage of 12 volts was applied using the electrode 4 as an anode and the electrode 7 as a cathode, and a current of 15.3 amps was passed to perform electrolysis. PH 2.4 from outlet
4. Acidic water having an oxidation-reduction potential of 1200 mV was discharged.

From these results, it was found that the electrolyte was not added to the tap water of the raw water, and the electrical resistance of the water was high, so that the voltage required in the ordinary electrolysis method was high. It was found that by using the electrode plate 3 of the present invention in which the electrodes 4 were laminated, the electrolysis could be performed efficiently at a relatively low voltage. The reason for this is that the distance between the diaphragm 5 and the electrode 4 which is a feature of the electrode plate 3 of the present invention is extremely short, the electric resistance is small, and the sodium chloride stored in the storage tank 10 during the electrolysis process. This is because the contained chlorine ions pass through the anion exchange membrane while carrying electrons, move to the electrolytic cell a side, and activate the electrolysis reaction on the surface of the electrode 4.

Embodiment 2 An embodiment using the water electrolysis apparatus shown in FIG. 4 will be described.
A glass beaker having a diameter of 11 cm and a height of 15 cm was used as the storage tank 10. This storage tank 10 was filled with an aqueous electrolyte solution 11. The electrolytic solution a
And an electrode 7 made of a stainless steel (SUS316) plate. In the electrolytic cell a, a part of a plastic cylinder having a diameter of 5 cm is constituted by the electrode plate 3. A DC voltage was applied with the electrode plate 4 of the electrode plate 3 as an anode and the electrode 7 as a cathode, and water 12 to be electrolyzed was passed through the electrolytic cell a to perform electrolysis. The electrode 4 of the electrode plate 3 was located on the electrolytic cell a side, and the diaphragm 5 was located on the storage tank 10 side. The electrode 4 has a cylindrical shape with a diameter of 5 cm and a height of 2.8 cm and an area of 44 cm.
^{In step 2} , a hole having a diameter of 1.5 mm was formed almost all over a titanium plate having a thickness of 0.1 mm. The aperture ratio at this time is 5
1%. An electrode 4 is formed by applying platinum plating with a thickness of 0.7 micron to the titanium plate having a large number of holes formed thereon, and further, on the side in contact with the diaphragm, a polyvinyl chloride resin layer 8 as a non-conductive material is formed. Was provided by painting. Diaphragm 5
Used was a sheet-like anion exchange membrane (“A-501” manufactured by Asahi Kasei Corporation). This electrode, a non-conductive material and a diaphragm were laminated to form an electrode plate 3.

The storage tank 10 was filled with an aqueous electrolyte solution 11 prepared by dissolving a hydrochloric acid electrolyte prepared by mixing 18 g of sodium chloride and 10 cc of 35% hydrochloric acid in 600 cc of water. The electrode plate 3 and the electrode 7 were immersed in the aqueous electrolyte solution 11. Tap water (pH
7.57, an oxidation-reduction potential 763) was flowed in at a rate of 340 cc / min, and taken out from the discharge pipe 14. Then, using the electrode 4 as an anode and the electrode 7 as a cathode, a DC voltage of 8 volts was impressed, a current of 6.1 amps was passed, electrolysis was performed, and 12 liters of water was taken out from the discharge pipe 14. This water was stored in a water tank. The pH of this water is 2.4
9. The oxidation-reduction potential was 1198 mV.

Example 3 Water electrolysis was carried out using the same water electrolysis apparatus as in Example 2. In this example, an aqueous electrolyte solution prepared by dissolving 50 cc of 35% hydrochloric acid in 550 cc of water was used as the aqueous electrolyte solution. From the introduction pipe 13 of the electrolytic cell a, tap water (p
H7.35, oxidation-reduction potential 765) were introduced at a rate of 340 cc / min, and were taken out from the outlet 14.
Then, the electrode 4 is used as an anode, the electrode 7 is used as a cathode, and a DC voltage of 8 volts is impressed. A current of 6.0 amperes is applied to perform electrolysis. This water was stored in a water tank. The pH of this water is 2.
56, the oxidation-reduction potential was 1197 mV.

[0034]

The water electrolysis apparatus of the present invention has a simplified structure, is inexpensive, and can efficiently produce target water, that is, acidic water or alkaline water. Then, the electrolytic solution is stored in the storage tank, and the electrolytic solution having the wall surface constituted by the electrode plate is arranged so as to be in contact with the electrolytic solution. Therefore, the design and manufacture of the electrolyzer are simple and easy. In addition, since the electrolyte aqueous solution can be stored in a larger amount than the electrolyte consumption, the management of the electrolyte aqueous solution is reduced. Also, if an ion exchange membrane is used for the diaphragm,
It is further advantageous that the elution of the electrolyte can be reduced. Furthermore, in the conventional water electrolysis method, acidic water and alkaline water were simultaneously generated, and water other than water having desired properties was also generated in substantially the same amount. However, water was electrolyzed using the electrolysis apparatus of the present invention. Decomposition is very convenient because only acidic or alkaline water can be obtained as long as the electrolyte required to obtain the desired water is present in the storage tank. In addition, there is an advantage that the size can be reduced so that no installation space is required.

[Brief description of the drawings]

FIG. 1 is a schematic view of an example of a water electrolysis apparatus of the present invention.

FIG. 2 is a sectional view of an electrolytic cell used in the water electrolysis apparatus of the present invention.

FIG. 3 is a schematic view of another example of the water electrolysis apparatus of the present invention.

FIG. 4 is a schematic view of another example of the water electrolysis apparatus of the present invention.

FIG. 5 is a sectional view of another example of the electrolytic cell used in the water electrolysis apparatus of the present invention.

FIG. 6 is a schematic view of another example of the water electrolysis apparatus of the present invention.

[Explanation of symbols]

a, a 'electrolytic cell, 1, 2 end of electrolytic cell, 3 electrode plate, 4, 21 sheet electrode, 5 sheet diaphragm, 6,
23 sheet-shaped electrode hole, 7 electrode, 8,22 sheet-shaped non-conductive material, 9,24 sheet-shaped non-conductive material hole, 10 storage tank, 11 electrolyte aqueous solution, 12 electrolyzed water, 19 bottom of electrolytic cell , 20 Upper part of electrolytic cell

Claims (7)

[Claims] 1. A water electrolysis apparatus comprising a storage tank containing an aqueous electrolyte solution, an electrode arranged in the storage tank, and an electrolytic tank arranged such that an outer wall of the aqueous electrolyte solution is in contact with the electrolyte solution in the storage tank. The electrolytic cell has an electrode plate in which all or a part of the wall surface is formed of an electrode plate, and the electrode plate is an electrode plate in which a sheet-like diaphragm and a sheet-like electrode having a large number of holes are sequentially stacked from the outside. Water electrolysis equipment. 2. A water electrolysis apparatus comprising a storage tank containing an aqueous electrolyte solution, an electrode arranged in the storage tank, and an electrolytic tank arranged so that an outer wall of the aqueous electrolyte solution is in contact with the electrolyte solution in the storage tank. The electrolytic cell is composed of an electrode plate in which all or a part of the wall surface is formed of an electrode plate. A water electrolysis apparatus comprising: an electrode plate on which electrodes are stacked; and a non-conductive material and a hole in the electrode plate penetrating therethrough. 3. The water electrolysis apparatus according to claim 1, wherein the diaphragm is an anion exchange membrane. 4. The water electrolysis apparatus according to claim 1, wherein the membrane is a cation exchange membrane. 5. The water to be electrolyzed is passed through the electrolytic cell of the water electrolyzer according to claim 1 or 2, and direct current is supplied to the electrode of the electrode plate constituting the electrolytic cell and the electrode arranged in the storage tank. A water electrolysis method characterized by applying a voltage and flowing an electric current. 6. The water to be electrolyzed is passed through the electrolytic cell of the water electrolyzer according to claim 3, the electrode of an electrode plate constituting the electrolytic cell is used as an anode, and the electrode arranged in the storage tank is used as an electrode. A water electrolysis method characterized by applying a DC voltage as a cathode and flowing an electric current. 7. The water to be electrolyzed is passed through the electrolytic cell of the water electrolyzer according to claim 4, the electrode of an electrode plate constituting the electrolytic cell is used as a cathode, and the electrode arranged in the storage tank is used as an electrode. A water electrolysis method characterized by applying a DC voltage as an anode and flowing an electric current.