JP2019214777A - Apparatus for producing chlorous acid-containing aqueous liquid - Google Patents

Abstract

To provide an apparatus for easily producing a chlorous acid-containing aqueous liquid from chlorite.SOLUTION: An apparatus 100 according to one embodiment produces a chlorous acid-containing aqueous liquid through electrolysis. The apparatus 100 comprises an anode 111, a cathode 112, a cell 120 in which the anode 111 and the cathode 112 are arranged, a cation exchange membrane 131, and a diaphragm 132. The cell 120 is partitioned into an intermediate cell 123, and an anode cell 121 and cathode cell 122 arranged to sandwich the intermediate cell 123 between them. The anode cell 121 and the intermediate cell 123 are partitioned with the cation exchange membrane 131. The intermediate cell 123 and the cathode cell 122 are partitioned with the diaphragm 132. An electrolytic solution 11 is arranged in the anode cell 121. A solution 12 of chlorite is arranged in the cathode cell 122. An aqueous liquid 13 is arranged in the intermediate cell 123.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an apparatus for producing an aqueous liquid containing chlorite.

  Aqueous solutions of chlorous acid are used for sterilization and other uses. However, aqueous chlorite solutions are unstable and may be difficult to store for long periods. Therefore, if an aqueous chlorite solution can be easily produced from chlorite, it is not necessary to store the aqueous chlorite solution for a long time, which is convenient. As a method for obtaining an aqueous chlorite solution, a method has been proposed in which sodium ions of sodium chlorite are ion-exchanged using an ion-exchange resin (Patent Document 1).

  However, in the method using an ion exchange resin, it is necessary to use a concentrated acid for the regeneration of the ion exchange resin, which is very inconvenient and the regeneration cost is high.

JP-A-2005-217334

  In the above situation, one of the objects of the present invention is to provide an apparatus capable of easily producing an aqueous liquid containing chlorite from chlorite.

  A manufacturing apparatus according to an embodiment of the present invention is a manufacturing apparatus that manufactures an aqueous liquid containing chlorite using electrolysis, and includes an anode, a cathode, a tank in which the anode and the cathode are arranged, and a cation. Exchange membrane, and, including a diaphragm, the tank is partitioned into an intermediate tank, an anode tank and a cathode tank arranged so as to sandwich the intermediate tank, the anode tank and the intermediate tank are the cations Are separated by an exchange membrane, the intermediate cell and the cathode cell are separated by the diaphragm, the anode cell is provided with the anode, and the cathode cell is provided with the cathode. An aqueous solution of an electrolyte is disposed in the anode cell, an aqueous solution of chlorite is disposed in the cathode cell, and an aqueous liquid is disposed in the intermediate cell.

  A manufacturing apparatus according to another embodiment of the present invention is a manufacturing apparatus that manufactures an aqueous liquid containing chlorite using electrolysis, and includes an anode, a cathode, a tank in which the anode and the cathode are arranged, And a cation exchange membrane, wherein the tank is partitioned into an anode tank and a cathode tank by the cation exchange membrane, the anode is disposed in the anode tank, and the cathode is A cathode is arranged, an aqueous solution of an electrolyte is arranged in the anode bath, an aqueous solution of chlorite is arranged in the cathode bath, and the cathode is an electrode for adsorbing cations during electrolysis.

  According to the present invention, an aqueous liquid containing chlorite can be easily produced.

FIG. 1 is a diagram schematically illustrating a configuration of an example of the device according to the first embodiment. FIG. 2 is a diagram illustrating an example of a method for producing water containing chlorite using the apparatus shown in FIG. FIG. 3 is a diagram illustrating an example of a method for producing water containing chlorite using another example of the apparatus of the first embodiment. FIG. 4 is a diagram schematically illustrating a configuration of another example of the device according to the first embodiment. FIG. 5 is a diagram schematically illustrating a configuration of an example of the device according to the second embodiment. FIG. 6 is a diagram illustrating an example of a method for producing water containing chlorite using the apparatus shown in FIG. FIG. 7 is a diagram illustrating an example of a method for producing water containing chlorite using another example of the apparatus of the second embodiment.

  An embodiment of the present invention will be described below. In the following description, embodiments of the present invention will be described by way of examples, but the present invention is not limited to the examples described below. In the following description, specific numerical values and specific materials may be exemplified, but the present invention is not limited to these examples.

(First Production Apparatus for Producing Aqueous Liquid Containing Chlorous Acid)
A first production apparatus for producing an aqueous liquid containing chlorite (HClO ₂ ) using electrolysis will be described below. Hereinafter, the first manufacturing apparatus may be referred to as “apparatus (E1)”.

  As used herein, "aqueous liquid" means a liquid containing water, typically a liquid in which the solvent is water. That is, a typical example of the aqueous liquid containing chlorous acid is an aqueous solution containing chlorous acid. Hereinafter, the aqueous liquid containing chlorous acid may be referred to as “aqueous chlorous acid solution”. It is considered that at least a part of the chlorous acid is dissociated in the aqueous solution to keep the equilibrium state.

  The apparatus (E1) includes an anode, a cathode, a vessel in which the anode and the cathode are arranged, a cation exchange membrane, and a diaphragm. The tank is partitioned into an intermediate tank and an anode tank and a cathode tank arranged so as to sandwich the intermediate tank. The anode tank and the intermediate tank are separated by a cation exchange membrane. The intermediate cell and the cathode cell are separated by a diaphragm. An anode is arranged in the anode tank. A cathode is arranged in the cathode cell. An aqueous solution of an electrolyte is disposed in the anode tank. An aqueous solution of chlorite is placed in the cathode cell. The aqueous liquid is arranged in the intermediate tank. Note that a solute other than chlorite may be dissolved in the aqueous solution of chlorite as long as the effects of the present invention can be obtained. Hypochlorite may be used as an example of a solute other than chlorite.

  In the device (E1), each of the anode and the cathode may be an electrode that generates a gas by electrolysis of water during electrolysis. Such an electrode may be referred to below as a “gas generating electrode”. The gas generating electrode may be an electrode having platinum on the surface. That is, the anode and the cathode may be electrodes each having platinum on the surface.

  Examples of the electrode having platinum on the surface include a metal electrode with a platinum coating on the surface, for example, a titanium electrode with a platinum coating on the surface.

  In the apparatus (E1), the anode may be a gas generating electrode, and the cathode may be an electrode that adsorbs cations during electrolysis. For example, the anode may be an electrode having platinum on the surface, and the cathode may be an electrode which adsorbs cations during electrolysis. Hereinafter, an electrode that adsorbs cations during electrolysis may be referred to as a “cation adsorption electrode”.

  The cation adsorption electrode is an electrode that adsorbs cations by applying a voltage. Examples of the cation adsorption electrode include an electrode containing activated carbon. The electrode containing activated carbon is not particularly limited, and a known activated carbon electrode or an activated carbon nonwoven fabric may be used. Since these cation adsorption electrodes adsorb ions reversibly, they can release the adsorbed ions.

  The shapes of the anode and the cathode are not particularly limited. From the viewpoint of the efficiency of electrolysis, an electrode spreading two-dimensionally may be used. For example, a plate-like electrode or a mesh-like electrode may be used.

  The cation exchange membrane is a membrane that allows the permeation of cations while suppressing the permeation of anions. The cation exchange membrane is not particularly limited, and a known cation exchange membrane can be used. As the cation exchange membrane, it is preferable to use a membrane which is stably present in an environment of electrolysis of the apparatus (E1) (in an environment where chlorite or the like is present). Examples of the cation exchange membrane include a fluororesin-based ion exchange membrane (for example, a fluoropolymer membrane having a sulfonic acid group).

  The diaphragm is a membrane that allows cations and anions to permeate. Further, the diaphragm is a membrane that allows the passage of liquid while suppressing the passage of liquid to some extent. Examples of such membranes include hydrophilic, porous membranes, such as separators. As the diaphragm, it is preferable to use a membrane that is stably present in the environment of the electrolysis of the device (E1).

  The tank may be any one that can stably hold the liquid arranged in the tank, and a tank generally used for an electrolytic tank can be applied.

  The device (E1) and the device (E2) described below usually include a DC power supply for applying a DC voltage between the anode and the cathode. The DC power supply is not particularly limited, and may be an AC-DC converter that converts an AC voltage from an outlet into a DC voltage and supplies the DC voltage. The voltage applied at the time of electrolysis is a voltage at which an electrolysis reaction (or electrolysis reaction and cation adsorption) described later occurs.

  In the device (E1), the electrolysis may be performed in a state where the aqueous liquid in the intermediate tank is flowing in a flow-through manner. Alternatively, the electrolysis may be performed in a state where the aqueous liquid in the intermediate tank is not flowing (batch type).

  In the device (E1) and the device (E2) to be described later, the electrolysis may be performed in a state where the aqueous solution in the anode tank is flowing in a flowing manner, and the state in which the aqueous solution in the cathode tank is flowing in a flowing manner. Electrolysis may be performed.

  Hereinafter, the electrolyte of the aqueous solution arranged in the anode tank may be referred to as “electrolyte (L)”. By disposing an aqueous solution of the electrolyte (L) in the anode tank, electrolysis is facilitated.

  The electrolyte (L) preferably releases hydrogen ions upon dissolution. Therefore, the electrolyte (L) is preferably at least one selected from acids and acid salts, and may be an acid, an acid salt, or a mixture of both. When reducing the amount of metal cations (eg, alkali metal ions) present in the intermediate tank, the electrolyte (L) preferably does not contain metal cations. In that case, the electrolyte (L) is preferably an acid. Hereinafter, the acid used as the electrolyte (L) may be described as “acid (A)”. Examples of the acid (A) include phosphoric acid, dilute sulfuric acid, boric acid and the like. Examples of the acid salt include those in which a part of the hydrogen ion of these acids is replaced with a metal cation (for example, an alkali metal ion). The acidic salt may be one obtained by substituting a part of hydrogen ions of phosphoric acid or sulfuric acid with an alkali metal ion (sodium ion or potassium ion).

The anion constituting the electrolyte (L) (for example, the acid (A) and the acid salt described above) is preferably an anion that is not easily electrolyzed at an anode at a potential at which water is electrolyzed. Examples of such anions include phosphate ions (PO ₄ ³⁻ ) and sulfate ions (SO ₄ ²⁻ ). That is, the acid (A1), which is a preferred example of the acid (A), is at least one acid selected from phosphoric acid and sulfuric acid. When the anion is chloride ion (Cl ⁻ ), chlorine gas may be generated by electrolysis. Therefore, it is preferable to use an electrolyte (L) containing no chloride ion from an environmental point of view.

  By allowing the metal cation to be present in the aqueous solution disposed in the anode tank, a part thereof can be moved to the intermediate tank. Thereby, it is also possible to adjust the pH of the intermediate tank. For example, the pH of the aqueous liquid containing chlorite obtained by electrolysis may be in the range of 2.1 to 9 by adjusting the metal cation concentration in the anode tank. Adjusting the pH to the range may improve the stability of the liquid in some cases.

  An electrolyte (L) containing a metal cation having low permeability to the cation exchange membrane may be used. For example, an electrolyte (L) containing a metal cation whose permeability of the cation exchange membrane is lower than that of hydrogen ions may be used. In that case, a cation exchange membrane having low permeability of the metal cation may be selected and used.

  The concentration of the aqueous solution of the electrolyte (L) is not particularly limited as long as a desired aqueous liquid of chlorous acid can be obtained. When phosphoric acid is used as the electrolyte (L), for example, a phosphoric acid aqueous solution having a pH of about 1 may be used.

Chlorite, which is a solute of the aqueous solution placed in the cathode cell, is a salt composed of chlorite ions (ClO ₂ ⁻ ) and cations other than hydrogen ions (eg, metal cations). The chlorite may be at least one selected from sodium chlorite and potassium chlorite. That is, the chlorite may be sodium chlorite, potassium chlorite, or a mixture of both. In that case, the above-mentioned preferred acid (A1) may be used as the electrolyte (L) of the aqueous solution disposed in the anode tank. Cations generated by dissolution of chlorite are attracted to the cathode side during electrolysis, and thus do not substantially move to the intermediate tank during electrolysis.

  The concentration of the aqueous solution of chlorite is not particularly limited as long as a desired aqueous liquid of chlorite is obtained. When sodium chlorite or potassium chlorite is used as the chlorite, for example, an aqueous solution having a concentration in the range of 1000 ppm to 4000 ppm (mass ppm) may be used.

  The aqueous liquid disposed in the intermediate tank is a liquid containing water, and may be any aqueous solution or general water (for example, tap water).

(First Method for Producing Aqueous Liquid Containing Chlorous Acid)
The first method for producing an aqueous liquid containing chlorite using electrolysis will be described below. Hereinafter, this first manufacturing method may be referred to as “manufacturing method (M1)”. The manufacturing method (M1) may be performed using the device (E1). The items described in the apparatus (E1) may be applied to the manufacturing method (M1). Similarly, the items described in the manufacturing method (M1) may be applied to the device (E1).

  The production method (M1) includes the following steps (i) and (ii). In the step (i), the above-described liquid is disposed in each of the anode tank, the intermediate tank, and the cathode tank described in the apparatus (E1). As described above, the anode is provided with the anode, and the cathode is provided with the cathode.

In the step (ii), a DC voltage is applied between the anode and the cathode. At this time, a voltage is applied so that oxygen gas (oxygen molecules) and hydrogen ions are generated at the anode by voltage application (electrolysis). When the cathode is a gas generation electrode, hydrogen gas (hydrogen molecules) and hydroxide ions are generated at the cathode by voltage application. On the other hand, when the cathode is a cation adsorption electrode, cations constituting chlorite are adsorbed on the cathode by voltage application. By the voltage application in step (ii), the concentration of chlorous acid in the aqueous liquid in the intermediate tank increases.
In this way, an aqueous liquid containing chlorous acid is produced.

(Second production device for producing aqueous liquid containing chlorous acid)
A second production apparatus for producing an aqueous liquid containing chlorite using electrolysis will be described below. Hereinafter, the second manufacturing apparatus may be referred to as “apparatus (E2)”.

  The apparatus (E2) includes an anode, a cathode, a vessel in which the anode and the cathode are arranged, and a cation exchange membrane. The cell is divided into an anode cell and a cathode cell by a cation exchange membrane. An anode is arranged in the anode tank. A cathode is arranged in the cathode cell. An aqueous solution of the electrolyte (L) is disposed in the anode tank. An aqueous solution of chlorite is placed in the cathode cell. The cathode is an electrode that adsorbs cations during electrolysis.

  The gas generating electrode described above can be used for the anode. The above-mentioned cation adsorption electrode can be used for the cathode. As the cation exchange membrane, the above-described cation exchange membrane can be used. The tank may be any one that can stably hold the liquid arranged in the tank, and a tank generally used for an electrolytic tank can be applied.

  The device (E2) may further include a third electrode disposed between the cation exchange membrane and the cathode. At least one time during the electrolysis, by setting the potential of the third electrode to a potential at which hydrogen ions are reduced to hydrogen molecules, the amount of hydrogen ions adsorbed on the cathode may be reduced in some cases. . The above-mentioned gas generating electrode can be used as the third electrode. It is preferable to use an electrode having a smaller hydrogen overvoltage than the cathode as the third electrode.

  The aqueous solution of the electrolyte described in the apparatus (E1) can be used as the aqueous solution of the electrolyte disposed in the anode tank. The aqueous chlorite solution described in the apparatus (E1) can be used as the aqueous chlorite solution disposed in the cathode cell. Preferred examples and preferred combinations thereof include the preferred examples and preferred combinations described in the device (E1).

(Second Method for Producing Aqueous Liquid Containing Chlorous Acid)
A second method for producing an aqueous liquid containing chlorite using electrolysis will be described below. Hereinafter, this second manufacturing method may be referred to as “manufacturing method (M2)”. The manufacturing method (M2) may be performed using the device (E2). The items described in the apparatus (E2) may be applied to the manufacturing method (M2). Similarly, the items described in the manufacturing method (M2) may be applied to the device (E2).

  The production method (M2) includes the following steps (I) and (II). In the step (I), the above-described liquid is disposed in each of the anode tank and the cathode tank described in the apparatus (E2). As described above, the anode is provided with the anode, and the cathode is provided with the cathode.

  In the step (II), a DC voltage is applied between the anode and the cathode. At this time, a voltage is applied such that oxygen gas and hydrogen ions are generated at the anode by voltage application (electrolysis), and cations constituting chlorite are adsorbed at the cathode (cation adsorption electrode). . By the voltage application in the step (II), the concentration of chlorite in the aqueous solution of the cathode tank increases. In this way, an aqueous liquid containing chlorous acid (typically, an aqueous solution of chlorous acid) is produced.

  In the production method (M2), the above-described third electrode may be used in the electrolysis in the step (II). At least temporarily during the electrolysis in the step (II), the potential of the third electrode is set to a potential at which hydrogen ions are reduced to hydrogen molecules.

  In one aspect, the manufacturing apparatus and the manufacturing method described above can be used as a manufacturing apparatus and a manufacturing method for manufacturing chlorite from chlorite. From another viewpoint, the above-described production apparatus and production method can be used as a method for removing a salt component (metal cation) in chlorite. For example, it is possible to remove 50% by mole or more (for example, 80% by mole or more) of chlorite by removing metal cations of chlorite disposed in the cathode cell. That is, it is possible to obtain an aqueous liquid having a molar ratio of chlorite: chlorite = 0 to 1: 1 (for example, 0 to 0.25: 1) in terms of a molar ratio in terms of a state before dissociation. It is.

  There is no particular limitation on the pH of the aqueous liquid of chlorite obtained by the above production apparatus and production method. The aqueous liquid may be acidic or neutral.

  The ambient temperature during the electrolysis and the temperature of the liquid placed in the tank are not particularly limited, and may be a general storage temperature (for example, about 10 ° C. or 5 ° C. to 20 ° C.). Good), a liquid at that temperature may be used.

  An embodiment of the present invention will be described below with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals, and redundant description may be omitted. As long as the effects of the present invention can be obtained, the configurations of the following embodiments can be replaced with the other configurations described above. Among the configurations of the devices of the following embodiments, configurations that are not necessary for achieving the effects of the present invention may be omitted. Items described for one embodiment can be applied to other embodiments as long as they do not contradict the configuration of the other embodiments. Therefore, description of items described in one embodiment may be omitted in the description of another embodiment. In the following figures, chemical formulas may be described ignoring electrical equivalents and chemical equivalents.

(Embodiment 1)
In the first embodiment, an example of the device (E1) will be described. FIG. 1 schematically shows a configuration of the manufacturing apparatus 100 according to the first embodiment.

  The apparatus 100 includes an anode (first electrode) 111, a cathode (second electrode) 112, a tank 120, a cation exchange membrane 131, a diaphragm 132, and a DC power supply 140. The tank 120 includes an anode tank 121, a cathode tank 122, and an intermediate tank 123 disposed therebetween. The anode tank 121 and the intermediate tank 123 are separated by a cation exchange membrane 131. The intermediate tank 123 and the cathode tank 122 are separated by a diaphragm 132.

  An anode 111 is arranged in the anode tank 121, and a cathode 112 is arranged in the cathode tank 122. Each of the anode 111 and the cathode 112 is a gas generating electrode, for example, a titanium electrode coated with platinum. The anode 111 and the cathode 112 are connected to a DC power supply 140.

  An aqueous solution 11 of the electrolyte (L) is arranged in the anode tank 121, and an aqueous solution 12 of chlorite is arranged in the cathode tank 122. The aqueous liquid 13 is disposed in the intermediate tank 123.

An example of a method for producing an aqueous chlorite solution (aqueous liquid containing chlorite) using the apparatus 100 will be described with reference to FIG. In the following, as an example, a case where an aqueous solution of phosphoric acid (H ₃ PO ₄ ) is used as the aqueous solution 11, an aqueous solution of sodium chlorite (NaClO ₂ ) is used as the aqueous solution 12, and water is used as the aqueous liquid 13 will be described. I do.

  First, the aqueous solution is placed in the anode tank 121 and the cathode tank 122, and water is placed in the intermediate tank 123. Next, a DC voltage is applied between the anode 111 and the cathode 112 by the DC power supply 140. At this time, a voltage is applied so that the anode 111 becomes an anode and the cathode 112 becomes a cathode. The applied voltage is a voltage at which water is electrolyzed. That is, a voltage at which oxygen gas is generated at the anode 111 and hydrogen gas is generated at the cathode 112 is applied. If the applied voltage is too high, anions of the electrolyte (L) may be electrolyzed, and the efficiency may be reduced. Therefore, it is preferable to apply a voltage at which water is electrolyzed but anions of the electrolyte (L) are not easily electrolyzed.

When water is electrolyzed by applying a voltage, oxygen gas and hydrogen ions (H ⁺ ) are generated at the anode 111. On the other hand, at the cathode 112, hydrogen gas and hydroxide ions (OH ⁻ ) are generated. The generated oxygen gas and hydrogen gas are released to the outside of the tank 120. Some of the hydrogen ions in the anode tank 121 move to the intermediate tank 123 through the cation exchange membrane 131 due to the electric field and the concentration gradient. Further, a part of the chlorite ion (ClO ₂ ⁻ ) in the cathode tank 122 moves to the intermediate tank 123 through the diaphragm 132 due to the electric field and the concentration gradient. As a result, the aqueous liquid in the intermediate tank 123 becomes an aqueous chlorite solution. The aqueous chlorite solution in the intermediate tank 123 can be used for sterilization and other uses.

  In the intermediate tank 123, part of the chlorite is dissociated into hydrogen ions and chlorite ions, and it is considered that the hydrogen ions and chlorite ions are in equilibrium with chlorite.

  Some of the hydroxide ions generated at the cathode 112 pass through the diaphragm 132 and move to the intermediate tank 123. As a result, when the electrolysis is continued, the concentration of hydroxide ions increases, and the increase in the concentration of chlorite in the aqueous liquid 13 may be suppressed. Further, if the electrolysis is continued, the concentration of chlorite ion in the cathode tank 122 decreases. Therefore, the liquid in the tank 120 may be replaced after the electrolysis is performed to some extent in order to obtain a chlorite aqueous solution having a high concentration.

  In the device 100, a cation adsorption electrode may be used as a cathode. An example of a method for producing an aqueous chlorite solution by the production apparatus 100a using the cathode 112a as a cation adsorption electrode will be described with reference to FIG. Hereinafter, an example of producing an aqueous chlorite solution using the same liquid as the example described in FIG. 2 will be described.

  First, as in the example described with reference to FIG. 2, the liquid is placed in the anode tank 121, the cathode tank 122, and the intermediate tank 123. Next, a DC voltage is applied between the anode 111 and the cathode 112a so that the anode 111 becomes an anode and the cathode 112a becomes a cathode. At this time, a voltage at which water is electrolyzed at the anode 111 to generate oxygen gas and cations (in this example, sodium ions) are adsorbed at the cathode 112a is applied. If the applied voltage is too high, the efficiency may decrease due to the decomposition of anions of the electrolyte (L) at the anode 111 or the electrolysis of water at the cathode 112a. Therefore, it is preferable to apply a voltage that does not easily cause the decomposition.

At the anode 111, oxygen gas and hydrogen ions are generated by the electrolysis. On the other hand, sodium ions are adsorbed on the cathode 112a. As described above, some of the hydrogen ions in the anode tank 121 pass through the cation exchange membrane 131 and move to the intermediate tank 123. A part of the chlorite ion (ClO ₂ ⁻ ) in the cathode tank 122 moves to the intermediate tank 123 through the diaphragm 132. As a result, the water in the intermediate tank 123 becomes an aqueous chlorite solution. When the cathode 112a, which is a cation adsorption electrode, is used, unlike the example shown in FIG. 2, an adverse effect caused by an excessive increase in hydroxide ion concentration can be avoided.

  When the electrolysis is continued in the apparatus of FIG. 3, the cation adsorption capacity of the cathode 112a decreases, and the concentration of chlorite ion in the cathode tank 122 decreases. To reduce the adsorption ability of the cathode 112a, the cathode 112a may be replaced, or the adsorbed cations may be released by applying a voltage in the opposite direction. To reduce the concentration of chlorite ions, the liquid in the cathode chamber 122 may be exchanged, or a high-concentration aqueous solution of sodium chlorite or sodium chlorite is charged into the cathode chamber 122. May be.

  In both the apparatus 100 and the apparatus 100a, the intermediate tank 123 may be of a liquid-flow type. FIG. 4 schematically shows a configuration of an example of the device 100 in that case when viewed from above. As shown in FIG. 4, two flow paths (an inflow path 150a and an outflow path 150b) are connected to the intermediate tank 123. The aqueous liquid 13 is introduced into the intermediate tank 123 from the inflow path 150a. Then, the aqueous chlorite solution generated by the electrolysis is taken out from the outflow passage 150b. According to this configuration, the aqueous chlorite solution can be continuously produced and used.

(Embodiment 2)
In the second embodiment, an example of the device (E2) will be described. FIG. 5 schematically shows the configuration of the manufacturing apparatus 200 according to the second embodiment.

  The apparatus 200 includes an anode (first electrode) 111, a cathode (second electrode) 112a, a tank 120, a cation exchange membrane 131, and a DC power supply 140. The tank 120 is partitioned into an anode tank 121 and a cathode tank 122 by a cation exchange membrane 131.

  In the device 200, the anode 111 is a gas generation electrode, and the cathode 112a is a cation adsorption electrode. An aqueous solution 11 of the electrolyte (L) is arranged in the anode tank 121, and an aqueous solution 12 of chlorite is arranged in the cathode tank 122.

  An example of a method for producing an aqueous chlorite solution (aqueous liquid containing chlorous acid) using the apparatus 200 will be described with reference to FIG. Hereinafter, as an example, a case will be described in which a phosphoric acid aqueous solution is used as the aqueous solution 11 and a sodium chlorite aqueous solution is used as the aqueous solution 12.

  First, the aqueous solution is placed in the anode tank 121 and the cathode tank 122. Next, a DC voltage is applied between the anode 111 and the cathode 112a by the DC power supply 140. At this time, a voltage is applied in the same manner as in the method described with reference to FIG.

  At the anode 111, oxygen gas and hydrogen ions are generated by the electrolysis. On the other hand, sodium ions are adsorbed on the cathode 112a. As described above, some of the hydrogen ions in the anode cell 121 pass through the cation exchange membrane 131 and move to the cathode cell 122. As a result, the liquid in the cathode tank 122 becomes an aqueous chlorite solution.

  When the electrolysis is continued in the apparatus shown in FIG. 6, the cation adsorption capacity of the cathode 112a is reduced. The reduction in the adsorption capacity of the cathode 112a may be dealt with by the above-described method.

  When the hydrogen ion concentration in the cathode tank 122 increases, not only sodium ions but also hydrogen ions are easily adsorbed on the cathode 112a. When the hydrogen ions are adsorbed, the production efficiency is reduced accordingly. The device 100a shown in FIG. 3 has an advantage that hydrogen ions are less likely to be adsorbed on the cathode 112a than the device 200 shown in FIG.

  The device (E2) may include the third electrode described above. An example of a method for manufacturing an aqueous chlorite solution using the manufacturing apparatus 200a including the third electrode 113 will be described with reference to FIG. The device 200a of FIG. 7 has the same configuration as the device 200 except that the device 200a includes the third electrode 113.

  The third electrode 113 is, for example, an electrode having platinum on the surface. In the example shown in FIG. 7, the cathode 112a and the third electrode 113 are electrically connected to have substantially the same potential. In this case, cations are adsorbed to the cathode 112a with the electrolysis, and both the potential of the cathode 112a and the potential of the third electrode 113 decrease. Consider a case where an electrode having a small hydrogen overvoltage is used as the third electrode 113, such as a case where an activated carbon electrode is used for the cathode 112a and a platinum electrode is used for the third electrode 113. In this case, first, hydrogen gas generation is started at the third electrode 113. By the generation of hydrogen gas at the third electrode 113, the amount of hydrogen ions adsorbed on the cathode 112a may be reduced, and as a result, the utilization efficiency of the cathode 112a may be increased.

  Note that the potential of the third electrode 113 may be different from the potential of the cathode 112a without connecting the third electrode 113 to the cathode 112a. In that case, the potential of the third electrode 113 is set to a potential at which hydrogen ions are reduced to hydrogen molecules at least at a time during the electrolysis. Thus, the amount of hydrogen ions adsorbed on the cathode 112a can be reduced.

  The apparatus 200a can also produce an aqueous chlorite solution in the same manner as the apparatus 200. However, in the device 200a, some hydrogen ions are reduced to hydrogen gas by the third electrode 113. Therefore, it is considered that it is possible to prevent sodium ions from being hardly adsorbed on the cathode 112a due to the adsorption of hydrogen ions on the cathode 112a (cation adsorption electrode).

  INDUSTRIAL APPLICATION This invention can be utilized for manufacture of the aqueous liquid containing chlorite.

Reference Signs List 11 aqueous solution of electrolyte 12 aqueous solution of chlorite 13 aqueous liquid 100, 100a, 200, 200a manufacturing apparatus 111 anode 112, 112a cathode 113 third electrode 120 tank 121 anode tank 122 cathode tank 123 intermediate tank 131 cation exchange membrane 132 diaphragm 140 DC power supply

Claims (7)

A production apparatus for producing an aqueous liquid containing chlorite using electrolysis,
An anode, a cathode, a vessel in which the anode and the cathode are arranged, a cation exchange membrane, and a diaphragm,
The tank is divided into an intermediate tank and an anode tank and a cathode tank arranged so as to sandwich the intermediate tank,
The anode tank and the intermediate tank are partitioned by the cation exchange membrane,
The intermediate tank and the cathode tank are partitioned by the diaphragm,
The anode is disposed in the anode tank,
The cathode is disposed in the cathode tank,
An aqueous solution of an electrolyte is arranged in the anode tank,
An aqueous solution of chlorite is arranged in the cathode cell,
An apparatus for producing an aqueous liquid containing chlorite, wherein an aqueous liquid is disposed in the intermediate tank.   The manufacturing apparatus according to claim 1, wherein the anode and the cathode are electrodes each having platinum on the surface. The anode is an electrode having platinum on its surface,
The manufacturing apparatus according to claim 1, wherein the cathode is an electrode that adsorbs cations during electrolysis.   The production apparatus according to any one of claims 1 to 3, wherein the electrolysis is performed in a state where the aqueous liquid in the intermediate tank is flowing in a flow-through manner. A production apparatus for producing an aqueous liquid containing chlorite using electrolysis,
An anode, a cathode, a vessel in which the anode and the cathode are arranged, and a cation exchange membrane,
The tank is partitioned into an anode tank and a cathode tank by the cation exchange membrane,
The anode is disposed in the anode tank,
The cathode is disposed in the cathode tank,
An aqueous solution of an electrolyte is arranged in the anode tank,
An aqueous solution of chlorite is arranged in the cathode cell,
An apparatus for producing an aqueous liquid containing chlorite, wherein the cathode is an electrode that adsorbs cations during electrolysis.   The manufacturing apparatus according to any one of claims 1 to 5, wherein the electrolyte is at least one selected from an acid and an acid salt. The manufacturing apparatus according to any one of claims 1 to 6, wherein the chlorite is at least one selected from sodium chlorite and potassium chlorite.

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