JP6869188B2 - Reduction water production equipment and reduction water production method - Google Patents

Description

The present invention relates to reduced water (hydrogen water) containing hydrogen obtained by electrolytic reduction, and more particularly to an apparatus and method capable of suppressing a decrease in the concentration of dissolved hydrogen molecules in the reduced water.

In recent years, businesses using hydrogen water have become active. Examples of the method for producing hydrogen water include an electrolytic reduction method in which water is electrolytically reduced to directly generate dissolved hydrogen molecules in water, and a method in which hydrogen gas is bubbled in water to dissolve hydrogen molecules. , A hydrogen gas pressure dissolution method for pressurizing and dissolving hydrogen gas in water is known.

Under atmospheric pressure and room temperature (20-28 ° C.), the equilibrium-theoretical solubility of hydrogen gas is 1.5-1.6 ppm.
Since the reduced water produced by electrolytic reduction is in contact with the atmosphere, the concentration of dissolved hydrogen molecules in the water is considerably lower than 1.5 ppm. For example, when the electrolyzed reduced water is stored in a PET bottle or the like, the concentration of dissolved hydrogen molecules in the water becomes 0.5 ppm or less after a lapse of a certain period of time. When hydrogen water is stored in contact with the atmosphere in this way, some of the dissolved hydrogen molecules volatilize into the atmosphere, so that the concentration of the dissolved hydrogen molecules decreases.
Therefore, for example, the technique described in Patent Document 1 has been proposed for the purpose of suppressing a decrease in the concentration of dissolved hydrogen molecules in the obtained hydrogen water.

JP-A-2015-009175

Further techniques for suppressing the decrease in the concentration of dissolved hydrogen molecules are required. An object of the present invention is to provide a novel technique capable of suppressing a decrease in the concentration of dissolved hydrogen molecules in reduced water obtained by electrolytic reduction.

As a result of diligent research, the present inventor applies a predetermined current to the cathode electrode in the electrolytic cell involved in the reduction reaction when electrolyzing to generate hydrogen, or causes electrolytic reduction to proceed, or electrolytic reduction. The present invention has been completed by finding that it is possible to suppress a decrease in the concentration of dissolved hydrogen molecules by generating hydrogen in the vicinity of the cathode electrode and applying vibration by a predetermined ultrasonic wave to the cathode electrode.

That is, the gist of the present invention is as follows.
[1] An anode chamber, a cathode chamber, a diaphragm which is a fluorine-based ion exchange film arranged between the anode chamber and the cathode chamber, and porosity arranged so as to be in contact with the diaphragm in the anode chamber. An electrolytic cell including an anode electrode and a cathode electrode arranged in the cathode chamber,
To generate hydrogen by applying a current having an AC component having an average current value of 10 kHz or less to zero or more to the cathode electrode and electrolytically reducing the water supplied between the diaphragm and the cathode electrode. , And an electric current having a DC component is applied to the cathode electrode to electrolyze and reduce the water supplied between the diaphragm and the cathode electrode to generate hydrogen, and 30 kHz or more and 10 MHz on the surface of the cathode electrode. A reduced water production apparatus including a concentration reduction suppressing unit that executes at least one of applying mechanical vibration in the following ultrasonic region.
[2] In the apparatus according to [1]
A reduced water production apparatus in which a current having an alternating current component having an average current value of 10 kHz or less is zero or more is a current having an alternating current component having a minimum current value of zero or more.
[3] In the apparatus according to [1] or [2].
A reduced water production apparatus in which a current having an alternating current component having an average current value of 10 kHz or less is zero or more is an alternating current that has been half-wave rectified or full-wave rectified.
[4] In the apparatus according to any one of [1] to [3].
The concentration reduction suppressing unit applies a half-wave rectified or full-wave rectified alternating current of 10 kHz or less to the cathode electrode to perform electrolytic reduction of water, and 30 kHz or more and 10 MHz or less on the surface of the cathode electrode. A reduced water production device that applies mechanical vibration in the ultrasonic region.
[5] In the apparatus according to any one of [1] to [4].
A reduced water production apparatus in which an ion exchange resin is filled between the diaphragm and the cathode electrode.
[6] In the apparatus according to [5]
The concentration decrease suppressing portion has an ultrasonic vibrator embedded in the ion exchange resin.
The concentration decrease suppressing unit is a reduced water producing apparatus that applies mechanical vibration from the ultrasonic vibrator to the surface of the cathode electrode in an ultrasonic region of 30 kHz or more and 10 MHz or less.
[7] In the apparatus according to any one of [1] to [4].
The cathode chamber has a plurality of protrusions on a surface facing the diaphragm, and the cathode pole is arranged so as to be in contact with the protrusion at the tip of the protrusion, and is between the cathode pole and the diaphragm. A reduced water production apparatus having a distance of 1 mm or less in a direction orthogonal to the diaphragm.
[8] In the apparatus according to [7]
The cathode electrode is a porous cathode electrode,
The cathode chamber includes a plurality of raw material water supply units for flowing water from the cathode chamber and a plurality of reduced water discharge units for discharging electrolytically reduced water from the cathode chamber, and the raw material water supply unit and the above. The reduced water discharge unit is a reduced water producing apparatus arranged with the protruding portion in between.
[9] In the apparatus according to any one of [1] to [8].
The electrolytic cell is a three-chamber type electrolytic cell having an anode chamber, a cathode chamber, and an intermediate chamber arranged between the anode chamber and the cathode chamber and separated from the anode chamber and the cathode chamber by the diaphragm. A reduced water production apparatus in which a reducing substance is present in the intermediate chamber.
[10] An anode chamber, a cathode chamber, a diaphragm which is a fluorine-based ion exchange film arranged between the anode chamber and the cathode chamber, and porosity arranged so as to be in contact with the diaphragm in the anode chamber. Water is supplied between the diaphragm and the cathode electrode in the electrolytic cell including the anode electrode and the cathode electrode arranged in the cathode chamber.
A current having an AC component having an average current value of 10 kHz or less is zero or more is applied to the cathode electrode to perform electrolytic reduction of water to generate hydrogen, and a current having a DC component to the cathode electrode is applied. Hydrogen is applied to generate hydrogen by electrolytically reducing water, and at least one of applying mechanical vibration in the ultrasonic region of 30 kHz or more and 10 MHz or less to the surface of the cathode electrode. A method for producing reduced water containing.
[11] In the method described in [10],
A method for producing reduced water, wherein a current having an alternating current component having an average current value of 10 kHz or less is zero or more is a current having an alternating current component having a minimum current value of zero or more.
[12] In the method according to [10] or [11],
A method for producing reduced water in which a current having an alternating current component having an average current value of 10 kHz or less is zero or more is an alternating current that is half-wave rectified or full-wave rectified.
[13] In the method according to any one of [10] to [12],
Half-wave rectified or full-wave rectified alternating current of 10 kHz or less is applied to the cathode electrode to perform electrolytic reduction of water, and the surface of the cathode electrode is mechanically located in an ultrasonic region of 30 kHz or more and 10 MHz or less. A method for producing reduced water that imparts vibration.
[14] In the method according to any one of [10] to [13],
A method for producing reduced water in which an ion exchange resin is filled between the diaphragm and the cathode electrode.
[15] In the method described in [14],
Mechanical vibration in the ultrasonic region of 30 kHz or more and 10 MHz or less is applied to the surface of the cathode electrode, and the mechanical vibration is applied from the ultrasonic vibrator embedded in the ion exchange resin. A method for producing reduced water.
[16] In the method according to any one of [10] to [13],
The cathode chamber has a plurality of protrusions on a surface facing the diaphragm, and the cathode pole is arranged so as to be in contact with the protrusion at the tip of the protrusion, and is between the cathode pole and the diaphragm. A method for producing reduced water for supplying water between the diaphragm and the cathode electrode in the electrolytic cell in which the distance in the direction orthogonal to the diaphragm is 1 mm or less.
[17] In the method described in [16],
The cathode electrode is a porous cathode electrode,
The cathode chamber includes a plurality of raw material water supply units for flowing water from the cathode chamber and a plurality of reduced water discharge units for discharging electrolytically reduced water from the cathode chamber, and the raw material water supply unit and the above. The reduced water discharge portion is a method for producing reduced water, which is arranged with the protruding portion in between.
[18] In the method according to any one of [10] to [17],
The electrolytic cell is a three-chamber type electrolytic cell having an anode chamber, a cathode chamber, and an intermediate chamber arranged between the anode chamber and the cathode chamber and separated from the anode chamber and the cathode chamber by the diaphragm. A method for producing reduced water in which a reducing substance is present in the intermediate chamber.

According to the present invention, it is possible to provide a novel technique capable of suppressing a decrease in the concentration of dissolved hydrogen molecules in the reduced water obtained by electrolytic reduction.

It is a figure which shows the outline of the system which concerns on 1st Embodiment. It is a figure which shows the outline of the electrolytic cell which concerns on 2nd Embodiment. It is a figure which shows the outline of the system which concerns on 2nd Embodiment. It is a figure which shows the outline of the electrolytic cell which concerns on 2nd Embodiment. It is a figure which shows the outline of the system which concerns on 3rd Embodiment. It is a figure which shows the outline of the electrolytic cell which concerns on 4th Embodiment. It is a figure which shows the outline of the electrolytic cell which concerns on 4th Embodiment. It is a figure which shows the outline of the system which concerns on 5th Embodiment. It is a figure which shows the outline of the electrolytic cell which concerns on other embodiment. It is a figure which shows the outline of the system which concerns on other embodiment. It is a graph about the dissolution amount (equilibrium value) of a hydrogen molecule at atmospheric pressure normal temperature. It is a figure which shows typically the neighborhood of the cathode electrode surface. It is a graph which shows the hydrogen molecule bubble generation amount by a half-wave rectified electrolysis current, and the size thereof.

[First Embodiment]
Next, one embodiment of the present invention will be described.
In the first embodiment, the anode chamber, the cathode chamber, the diaphragm which is a fluorine-based ion exchange film arranged between the anode chamber and the cathode chamber, and the porosity arranged so as to be in contact with the diaphragm in the anode chamber. An electrolytic cell having an anode electrode and a cathode electrode arranged in a cathode chamber,
A concentration reduction suppressor that generates hydrogen by applying a current having an AC component with an average current value of 10 kHz or less to zero or more to the cathode electrode and electrolytically reducing the water supplied between the diaphragm and the cathode electrode. The present invention relates to a reduced water production apparatus including.

First, the configuration of the system according to the first embodiment will be described.
FIG. 1 is a diagram showing an outline of the configuration of the system.
The system according to the first embodiment includes an electrolytic cell 100 and a raw material water generation liquid feeding unit 200 that supplies water as a raw material to the cathode chamber 3 of the electrolytic cell 100. From the viewpoint that the produced reduced water (hydrogen water) is more preferable for drinking, in the following description, a case where water having a conductivity of 200 μS / cm or less is supplied to the electrolytic cell 100 is taken as an example. The explanation is given, but the present invention is not limited to this.

In the first embodiment, the raw material water generation liquid feeding unit 200 can be composed of a reverse osmosis membrane filter 140 and a water supply pump 130. The reverse osmosis membrane filter 140 enhances the purity of tap water sent from the tap water line 150, and has a conductivity of 200 μS / cm or less (hereinafter, also referred to as raw material water; water having a conductivity of 20 μS / cm or less). It is more preferable.) The water supply pump 130 supplies the raw material water generated in the reverse osmosis membrane filter 140 to the cathode chamber 3 of the electrolytic cell 100.
As the water supply pump 130, the reverse osmosis membrane filter 140, and the water supply line 150, known ones can be used and are not particularly limited. Further, the configuration of the raw material water generation liquid feeding unit 200 is an example, and the raw material water may be supplied to the electrolytic cell 100 by another configuration.

The electrolytic cell 100 can be, for example, a two-chamber type electrolytic cell described in Patent Document 1. Specifically, the electrolytic cell 100 has a configuration having an anode chamber 1 and a cathode chamber 3. A diaphragm 5 which is a fluorine-based ion exchange membrane is arranged between the anode chamber 1 and the cathode chamber 3, and separates the anode chamber 1 and the cathode chamber 3. Further, a porous anode pole 21 is arranged in the anode chamber 1, and a cathode pole 4 is arranged in the cathode chamber 3. The porous anode pole 21 is arranged in the anode chamber 1 at a position in contact with the diaphragm 5. Further, the cathode pole 4 is arranged so as to form a wall portion facing the diaphragm 5 of the cathode chamber 3. Further, in the first embodiment, water having a conductivity of 200 μS / cm or less (preferably water having a conductivity of 20 μS / cm or less) is used between the diaphragm 5 of the cathode chamber and the cathode electrode 4. As a preferable configuration for reduction, the ion exchange resin 31 is filled.
The capacities of the anode chamber 1 and the cathode chamber 3, the material and size of the porous anode pole 21 and the cathode pole 4, the size and number of holes in the porous anode pole 21, etc. are not particularly limited, and those skilled in the art can use them. It can be set as appropriate.
Further, a voltage is applied to the anode pole 21 and the cathode pole 4 by supplying a current from the power supply 110. As a result, water is electrolyzed in the electrolytic cell 100, and a reduction reaction proceeds in the cathode chamber 3 to generate hydrogen. On the other hand, in the anode chamber 1, an oxidation reaction is carried out (detailed description and illustration are omitted because a known configuration can be used).

The reduced water containing hydrogen generated in the cathode chamber 3 of the electrolytic cell 100 is sent to the water storage tank 120 and stored. The inflow to the water storage tank 120 can be controlled by the valve 160. Further, it is also possible to control the pressure state in the cathode chamber 3 by operating the valve 160.

In the first embodiment, a current having an AC component having an average current value of 10 kHz or less of 10 kHz or less is zero or more with respect to the cathode electrode 4 is transmitted from the power supply 110 (corresponding to the concentration decrease suppressing portion in the first embodiment). It is applied and electrolytically reduced to generate hydrogen. Specifically, half-wave rectified or full-wave rectified alternating current of 10 kHz or less is applied to the cathode electrode 4 to perform electrolytic reduction of water to generate hydrogen.
Here, half-wave rectification and full-wave rectification refer to a process of converting a current / voltage component in a negative direction in an alternating current / voltage to zero or a positive side larger than zero.
The current having an AC component having an average current value of zero or more is not limited to half-wave rectified or full-wave rectified alternating current, and may be, for example, a pulse current. On the other hand, since the cost is high, it is preferable to apply a half-wave rectified or full-wave rectified alternating current of 10 kHz or less to perform electrolytic reduction of water to generate hydrogen.

As described above, in the first embodiment, the water supplied to the cathode chamber is electrolytically reduced by applying a current having an AC component having an average current value of 10 kHz or less to zero or more to the cathode electrode to obtain the equilibrium value. It can have a high dissolved hydrogen molecule concentration. As a result, it is possible to suppress a decrease in the concentration of dissolved hydrogen molecules.

[Second Embodiment]
Next, the second embodiment will be described. The parts common to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 2 is a diagram showing a configuration of a system according to a second embodiment. The system according to the second embodiment includes an electrolytic cell 100, a raw material water generation liquid feeding unit 200, a power supply 110, and a water storage tank 120, as in the first embodiment. Further, the system according to the second embodiment includes a mechanical vibration applying unit 8 that applies mechanical vibration to the surface of the cathode electrode 4 in the cathode chamber 3. In the second embodiment, a current having a direct current component is applied to the cathode electrode 4 to electrolyze and reduce the water in the cathode chamber 3 to generate hydrogen, and the mechanical vibration imparting unit 8 causes the inside of the cathode chamber 3 to be generated. Mechanical vibration in the ultrasonic region of 30 kHz or more and 10 MHz or less is applied to the surface of the cathode electrode 4. Therefore, in the second embodiment, the power supply 110 and the mechanical vibration applying unit 8 correspond to the concentration decrease suppressing unit.
The current applied to the cathode electrode 4 is not particularly limited as long as it has a direct current component, and in addition to the half-wave rectified or full-wave rectified alternating current of 10 kHz or less of the first embodiment, a direct current, etc. It may be. On the other hand, from the viewpoint of further suppressing the decrease in the dissolved hydrogen molecule concentration, the current applied to the cathode electrode 4 is preferably a half-wave rectified or full-wave rectified alternating current of 10 kHz or less. FIG. 2 illustrates a case where a half-wave rectified or full-wave rectified alternating current of 10 kHz or less is applied.

For the mechanical vibration imparting unit 8, for example, an ultrasonic vibrator can be used. The position where the mechanical vibration applying portion 8 is arranged is not particularly limited and can be appropriately set, but for example, it can be arranged at the position shown in FIGS. 3 and 4.
In FIG. 3, the mechanical vibration applying portion 8 is arranged at a position in contact with the cathode electrode 4 outside the electrolytic cell 100. Further, in FIG. 4, the mechanical vibration imparting portion 8 is embedded in the ion exchange resin 31 in the cathode chamber 3 and arranged near the surface of the cathode pole 4. Note that FIG. 2 illustrates a case where the mechanical vibration imparting portion 8 is embedded in the ion exchange resin 31 in the cathode chamber 3.
Of these, since the dissolved hydrogen concentration can be further increased by directly applying mechanical vibration to the surface of the cathode electrode 4, a mechanical vibration imparting portion 8 is installed inside the cathode chamber as illustrated in FIG. Is preferable.

As described above, in the second embodiment, the water in the cathode chamber is electrolytically reduced to generate hydrogen, and the surface of the cathode electrode 4 in the cathode chamber 3 is subjected to more than 30 kHz or more and 10 MHz or less by the mechanical vibration imparting unit 8. By applying mechanical vibration in the sonic region, the concentration of dissolved hydrogen molecules can be set higher than the equilibrium value. As a result, it is possible to suppress a decrease in the concentration of dissolved hydrogen molecules in the reducing water.

[Third Embodiment]
Next, a third embodiment will be described. The parts common to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.
FIG. 5 shows an outline of the system according to the third embodiment.
The system according to the third embodiment has a three-chamber type electrolytic cell 300 instead of the two-chamber type electrolytic cell 100 according to the first embodiment. The three-chamber type electrolytic cell 300 is arranged between the anode chamber 1 and the cathode chamber 3 in addition to the anode chamber 1 and the cathode chamber 3, and is separated from the anode chamber 1 and the cathode chamber 3 by the diaphragms 51 and 52. Has. As in the case of the first embodiment, in the third embodiment, the electrolytic cell 300 can be, for example, the three-chamber type electrolytic cell described in Patent Document 1. The intermediate chamber 6 is filled with an ion exchange resin, and purified water from which divalent or higher metal ions including alkaline earth metals such as calcium ions have been removed can be supplied (anode chamber 1). Since a known configuration can be used for the intermediate chamber 6 as in the case of the above, detailed description and illustration will be omitted).
By providing the intermediate chamber 6, it is possible to prevent the oxidizing substance such as oxygen generated in the anode chamber 1 from migrating to the cathode chamber 3.

[Fourth Embodiment]
Next, a fourth embodiment will be described. The parts common to the second embodiment are designated by the same reference numerals, and the description thereof will be omitted.
6 and 7 are diagrams showing an outline of the electrolytic cell 300 according to the fourth embodiment. Also in the fourth embodiment, as in the second embodiment, the position where the mechanical vibration imparting portion 8 is arranged is not particularly limited and can be appropriately set. For example, the mechanical vibration imparting portion 8 is arranged at the position shown in FIGS. can do.
In FIG. 6, the mechanical vibration applying portion 8 is arranged at a position in contact with the cathode electrode 4 outside the electrolytic cell 300. Further, in FIG. 7, the mechanical vibration imparting portion 8 is embedded in the ion exchange resin 31 in the cathode chamber 3 and arranged near the surface of the cathode pole 4.

[Fifth Embodiment]
Next, a fifth embodiment will be described. The parts common to the third and fourth embodiments are designated by the same reference numerals, and the description thereof will be omitted.
In the fifth embodiment, the organic acid-reducing substance is present in the intermediate chamber 6 of the three-chamber type electrolytic cell 300 in order to further suppress the decrease in the concentration of dissolved hydrogen molecules. As a result, the cathode water becomes weakly acidic, so that a decrease in the dissolved hydrogen molecule concentration can be further suppressed.
FIG. 8 shows an outline of the system according to the fifth embodiment.
In the fifth embodiment, the organic acid-reducing aqueous solution is passed through the intermediate chamber 6, and the reducing aqueous solution discharged from the outlet of the intermediate chamber 6 is guided to the intermediate chamber 6 to circulate the reducing aqueous solution. , An organic acid-reducing aqueous solution is filled in the intermediate chamber 6. As a result, the reducing substance is present in the intermediate chamber 6.
In the fifth embodiment, the circulation line 190 is provided to circulate the organic acid reducing aqueous solution. An intermediate chamber liquid circulation pump 180 and an intermediate chamber liquid water storage tank 170 are provided in the circulation line 190 to circulate a reducing aqueous solution.
Examples of the organic acid-reducing substance include ascorbic acid, lactic acid, and gluconic acid, and in the present embodiment, these aqueous solutions can be circulated.

[Other Embodiments]
As described above, the present invention has been described with reference to some embodiments, but other embodiments are also possible.
For example, in the first to fifth embodiments, as a preferable configuration for reduction using water having a conductivity of 200 μS / cm or less, the electrolytic cell is filled with an ion exchange resin between the cathode electrode and the diaphragm in the cathode chamber. It has a configuration that is. Other configurations may be used instead of this.
For example, an improved cathode electrode can be used that allows both water flow and low voltage electrolysis without filling with an ion exchange resin. Specifically, the cathode chamber has a plurality of protrusions on the surface facing the diaphragm, and the cathode pole is arranged so as to be in contact with the protrusion at the tip of the protrusion, and is located between the cathode pole and the diaphragm. The distance in the direction perpendicular to the diaphragm can be 1 mm or less. Specific examples of such a cathode chamber include a cathode electrode having a corrugated surface and a cathode electrode having a comb-shaped surface described in Patent Document 1.

Further, as an example of the above-mentioned reduced water production apparatus in which the distance between the cathode electrode and the diaphragm in the direction perpendicular to the diaphragm is 1 mm or less, a reduced water production apparatus having a cathode chamber frame as described below will be mentioned. Can be done.
FIG. 9 is a diagram showing an outline of the electrolytic cell according to the embodiment, and FIG. 10 is a diagram showing an outline of the system according to the embodiment.
As shown in FIG. 9, in the reduced water production apparatus of this embodiment, the porous cathode pole 4 having a plurality of openings is arranged in contact with the cathode chamber frame 400, and the porous cathode pole 4 and the diaphragm 5 are arranged in contact with each other. The distance between the diaphragm 5 and the diaphragm 5 in the direction orthogonal to the diaphragm 5 is set to 1 mm or less. Specifically, the cathode chamber frame 400 has a plurality of protrusions 320 on the surface facing the diaphragm 5, and the porous cathode pole 4 is in contact with the protrusion 320 at the tip of the protrusion 320. Is arranged so as to face the diaphragm 5.
Further, a plurality of raw material water supply lines 302 and a plurality of reduced water discharge lines 303 are connected to a non-protruding portion of the cathode chamber frame 400 facing the porous cathode pole 4 and which is not in contact with the cathode pole 4. The raw material water supply line 302 and the reduced water discharge line 303 are arranged with the protruding portion 320 in contact with the porous cathode electrode 4 interposed therebetween.
The raw material water supply line 302 communicates with the raw material water supply manifold 304. The raw material water is supplied to the raw material water supply manifold 304 from the raw material water inlet 306 that communicates with the raw material water supply manifold 304. The raw material water flows into the cathode chamber 3 from the raw material water supply line 302 via the raw material water supply manifold 304, and is porous through the opening in the non-contact portion of the porous cathode pole 4 with the protruding portion 320. It is supplied to the electrolytic surface 301 on the surface of the cathode electrode 4.
Further, the reduced water discharge line 303 communicates with the reduced water discharge manifold 305. The reduced water generated on the electrolytic surface flows into the reduced water discharge manifold 305 through the opening in the non-contact portion of the porous cathode electrode 4 with the protruding portion 320 and the reduced water discharge line 303. The reduced water outlet 307 communicates with the reduced water discharge manifold 305, and the reduced water generated from the reduced water outlet 307 is discharged. In the illustrated embodiment, the reduced water discharge line 303 and the reduced water discharge manifold 305 cannot be visually recognized in the cross section where the raw material water supply line 302 and the raw material water supply manifold 304 can be visually recognized. Therefore, in FIGS. 9 and 10, the reduced water discharge line 303 and the reduced water discharge manifold 305 are shown by broken lines.
That is, in this embodiment, the raw material water that has flowed into the cathode chamber from the raw material water supply line 302 is supplied to the electrolytic surface 301 through the opening in the non-contact portion of the porous cathode pole 4 with the protruding portion 320. Further, the reduced water generated on the electrolytic surface 301 is discharged from the reduced water drainage line 303 to the outside of the cathode chamber through the opening in the non-contact portion of the porous cathode electrode 4 with the protruding portion 320. According to such an aspect, the flow velocity on the surface of the cathode electrode, which is the electrolytic surface, can be further increased. As a result, the highly dissolved hydrogen molecule-concentrated water in the vicinity of the cathode electrode can be more efficiently transferred to the bulk water, so that the decrease in the dissolved hydrogen molecule concentration can be further suppressed.

[Giving vibration to the cathode electrode]
As shown in FIG. 11, the equilibrium-theoretical solubility of hydrogen gas is 1.5 to 1.6 ppm under the conditions of atmospheric pressure and normal temperature.
As a result of diligent research, the present inventor applies a current having an AC component having an average current value of zero or more to the cathode electrode in the electrolytic tank involved in the reduction reaction when electrolyzing to generate hydrogen. By advancing electrolytic reduction, or by applying an electric current having a DC component to the cathode electrode to advance electrolytic reduction to generate hydrogen in the vicinity of the cathode electrode, and by applying vibration by a predetermined ultrasonic wave to the cathode electrode. , The present invention has been completed by finding that it is possible to suppress a decrease in the concentration of dissolved hydrogen molecules. This point will be described in detail below.

When electrolyzing using an electrolytic cell, the existence state and dissolution process of saturated hydrogen on the surface of the cathode electrode have been analyzed by Saihara et al. Regarding hydrogen generation and hydrogen molecular bubbles on the surface of the cathode electrode (Yasuhiro Saihara, Matsushita Electric Works Co., Ltd.) , Trial Youth Implementation Report, August 12, 2003).
In bulk water, the dissolved hydrogen concentration is below the equilibrium theory value, but the dissolved hydrogen concentration on the surface of the cathode electrode during electrolysis is above the equilibrium value. Furthermore, the diameter of the hydrogen gas is on the order of nm at the initial stage, but with the passage of time, minute hydrogen gases coalesce with each other, and the size of the hydrogen gas increases.

The state of hydrogen gas generated on the surface of the cathode electrode is shown in FIG. Generally, the interface layer of an aqueous solution is composed of a Helmholtz layer 10 and an electric double layer (diffusion layer) 9. The Helmholtz layer 10 is divided into an inner Helmholtz layer and an outer Helmholtz layer. When an aqueous solution from which ions and the like have been removed is used at the time of water supply, the main molecule of the Helmholtz layer 10 is a water molecule which is a solvent molecule. The water molecule H2O, which is a solvent molecule, is reduced and decomposed by the following reaction formula to generate a hydrogen molecule. As a result, the hydrogen molecule becomes the main molecule of the Helmholtz layer 10.
_{Anode: 2H 2 O → O 2 +} 4H + + 4e -
The ^{cathode: 2H + + 2e - → H} 2
For example, as illustrated in FIG. 12, the hydrogen molecule or the hydrogen molecule bubble 11 having a very small diameter (nm order) generated in the Helmholtz layer 10 has a larger diameter in the process of moving to the electric double layer 9. It becomes a bubble 13, and as the distance from the cathode electrode 4 further increases, it becomes a hydrogen molecular bubble 12 larger than the hydrogen molecular bubble 13. In such a dynamic process, the dissolved hydrogen concentration is expected to be higher than the value from the equilibrium point of view.

Here, the amount of hydrogen gas generated when electrolyzed at a current density of 0.2 A / cm ^{2 is simply calculated.} Assuming that electrolysis is performed under this condition within 1 μm of the cathode electrode surface per unit area, about 800 ppm of hydrogen molecules will be generated in the cathode electrode surface layer. Assuming that hydrogen molecules are dissolved at this concentration, based on the experiments by AHPray et al. (HA PRAY et al., IN DUSRIAL AND ENGI NEERING CHEMISTRY Vol. 44, No. 5, 1146), the surface of the cathode electrode The value when the dissolved hydrogen molecule concentration in is converted into pressure is assumed to be about 1000 HPa or more. In other words, it is a hydrogen gas dissolution phenomenon under a high pressure of about 1000 HPa or more. Since the surface of the cathode electrode during the electrolytic reaction is in a non-equilibrium state as described above, it is clear that the dissolved hydrogen molecule concentration is dissociated from the equilibrium value. The present invention relates to a method for effectively utilizing dissolved hydrogen molecules on the surface of the cathode electrode in this non-equilibrium state.
Furthermore, the report by Saihara et al. Describes that hydrogen gas with a size of 200 nm was observed on the surface of the cathode electrode. It has been reported that when the size of the hydrogen gas is 200 nm or less, it becomes visually uniform and transparent, and the stability in the water electrolyzed by the hydrogen gas is improved. This stability is important in terms of the lifetime of hydrogen gas residue in developing the business of water in which hydrogen molecules are dissolved.

The present inventor efficiently converts highly dissolved hydrogen molecule-concentrated water near the cathode electrode into bulk water in order to generate reduced water by making the dissolved hydrogen molecule concentration larger than the equilibrium concentration value and suppress a decrease in the dissolved hydrogen molecule concentration. I came up with the idea of migrating to. The present invention relates to a method of efficiently transferring highly dissolved hydrogen molecule-concentrated water in the vicinity of the cathode electrode to bulk water by applying a dynamic action to the surface of the cathode electrode.

Specifically, the dissolved hydrogen concentration in the reduced water can be increased by any of the methods shown as (1) and (2) below.
(1) Ultrasonic application The Helmholtz layer and the electric double layer (diffusion layer) are agitated by ultrasonic vibration, and the small-diameter hydrogen gas bubbles in the Helmholtz layer move to the electric double layer (diffusion layer) by this agitation, and electricity is generated. The concentration of small-diameter hydrogen gas bubbles increases in the double layer. As a result, the concentration of hydrogen gas having a small diameter in the bulk water increases, and the concentration of dissolved hydrogen in the obtained reduced water also increases.
(2) Application of Electrical Vibration (Fluctuating Electrolytic Current) In this method, the concentration of dissolved hydrogen in reduced water is increased by applying a current having an alternating current component having an average current value of zero or more to the cathode electrode.
In this method, instead of applying a constant electrolytic current, a period during which the electrolytic current is reduced to zero is provided. FIG. 13 shows a graph which is an example of the current application and the generated hydrogen gas according to the method. FIG. 13 is a graph corresponding to the case where a half-wave rectified current is applied to the cathode electrode in Experimental Example 1 described later. In FIG. 13, a half-wave rectified current is applied to the cathode electrode as shown by the dotted current value. There is. Large bubbles of hydrogen gas (larger than 1 μm) are generated in response to this change in current. When energized, small hydrogen gas bubbles (1 μm or less) are always supplied, so that hydrogen gas bubbles having a large diameter are generated. When water is passed through the electrode surface, hydrogen gas having a large diameter is removed. However, since the flow velocity is significantly reduced in the interface layer of the Helmholtz layer and the electric double layer, hydrogen gas having a small diameter remains partially. When no electricity is applied, the growth of the gas stops and only hydrogen gas with a small diameter can be removed. As a result, hydrogen gas having a diameter smaller than that of hydrogen gas that is removed when no electricity is applied remains in the reduced water, and the concentration of dissolved hydrogen can be increased. Further, in order to increase the dissolved hydrogen concentration, it is desirable to increase the pressure in the cathode chamber, and specifically, it is preferable to set the pressure in the cathode chamber to 0.01 to 0.1 kg / cm ² .
The above explanation shows that alternating current is desirable to increase the concentration of dissolved hydrogen. However, it should be noted here that the cathode electrolysis reaction is the target, so if a normal alternating current is used in alternating current, the anodic reaction will be mixed in and the concentration of dissolved hydrogen molecules will be increased. Becomes difficult. Therefore, it is necessary to reduce the value of the electrolytic current to a value at which it is difficult to visually observe hydrogen gas bubbles having a large diameter at the cathode electrolytic current. Specifically, a current having an alternating current component having an average current value of zero or more can be applied to the cathode electrode, and a current having an alternating current component having a minimum current value of zero or more is preferable. A half-wave or full-wave rectified alternating current is applied to the cathode pole. Therefore, for example, a rectified AC power supply or a pulse power supply can be used as a power supply for a current having an AC component having an average current value of zero or more.
Since the present invention focuses on the efficient movement of hydrogen gas bubbles, there is a limit to the upper limit of frequency. Generally, when the frequency dependence of a phenomenon involving mass transfer is measured, the effect of alternating current or pulse current appears on electrolysis in the region of about 10 kHz or less.

[Experimental Example 1]
A system based on the first embodiment described above was constructed.
As the reverse osmosis membrane filter 140, a reverse osmosis membrane filter manufactured by Seemsbionics was used. A DC power supply or a 50 Hz AC power supply was used as the power source. The alternating current was non-rectified, full-wave rectified, or half-wave rectified, and comparison was performed. The size of the electrolytic cell was 6 × 8 × about 1 cm for both the anode chamber and the cathode chamber. The outer dimensions of the electrodes were 8 x 6 cm ² (material: titanium plate plated with platinum). The anode electrode was a porous anode electrode with 130 holes of 6 mmφ at the same interval. The electrolytic current was set to 4A. The current density is 0.83 mA / cm ² .
The concentration of dissolved hydrogen molecules in the reducing water was measured with a methylene blue reagent.
The results are shown in Table 1.

When electrolyzed with the same current value, the dissolved hydrogen concentration value of about 1.5 ppm was not exceeded from the viewpoint of equilibrium theory when direct current was used. However, when a full-wave rectified or half-wave rectified current is applied, it has become possible to obtain a measured value in which the dissolved hydrogen molecule concentration exceeds the equilibrium value. This result shows that it is possible to generate dissolved hydrogen molecule-concentrated water having a concentration exceeding the equilibrium value by using the electrolytic cell and the electrolytic conditions of the present invention.

[Experimental Example 2]
In this Experimental Example 2, the effect of mechanical vibration on the concentration of dissolved hydrogen molecules will be described.
Approximately 250Hz vibration device (manufactured by WILD ONE) and approximately 2. A 4 MHz ultrasonic transducer (Honda Electronics Co., Ltd., HM2412 (C)) was used. The basic system configuration is the same as in Experimental Example 1. The method of applying mechanical vibration to the surface of the cathode electrode was as follows. In the case of low-frequency mechanical vibration of about 250 Hz, which is a control, the vibrating device was placed outside the electrolytic cell at a position in contact with the cathode electrode, and vibration was applied from the outside of the electrolytic cell. In the case of ultrasonic vibration of about 2.4 MHz, the two structures shown in FIGS. 3 and 4 were examined in the two-chamber electrolytic cell. That is, as shown in FIG. 3, the ultrasonic transducer is attached at a position in contact with the cathode electrode outside the electrolytic cell, and as shown in FIG. 4, the ultrasonic transducer is ion-exchanged in the vicinity of the cathode electrode surface in the cathode chamber. We prepared the one that was installed by embedding it in resin.

The results are shown in Tables 2 and 3. As shown in Tables 2 and 3, low frequency mechanical vibration (about 250 Hz) had no effect on increasing the dissolved hydrogen concentration. Using a DC power supply and ultrasonic vibration (about 2.4 MHz), the dissolved hydrogen molecule concentration was measured transiently at 1.8 ppm, and the result exceeded the equilibrium value. Furthermore, it was found that the combined use of ultrasonic irradiation and rectified alternating current increases the dissolved hydrogen concentration transiently.

[Experimental Example 3]
A reduced water production system including the three-chamber type electrolytic cell shown in FIG. 7 was constructed. The size of the anode chamber, the cathode chamber and the intermediate chamber was 6 × 8 × about 1 cm. Purified water and 50 g of ascorbic acid were added to the intermediate chamber (concentration: about 5%). This aqueous solution was constantly circulated. Other configurations and the like were the same as in Experimental Example 1.
In this state, full-wave rectification of 50 Hz and 4 A was applied to the cathode electrode, and 0.5 l / min. Water was passed. The valve at the outlet of the electrolytic cell was adjusted to adjust the pressure in the cathode chamber to 0.1 kg / cm2. Transient dissolved hydrogen molecule concentration measurements increased to 2.6ppm compared to the middle chamber solution circulation before 2.3 ppm.

[Experimental Example 4]
Reduced water was produced in an electrolytic cell using the cathode chamber frame (6X8 cm ^{2) shown in FIG.} The distance between the fluorine-based cation exchange membrane and the porous cathode electrode was 1 mm. Raw water treated with tap water using a reverse osmosis membrane filter was supplied to the cathode chamber of the electrolytic cell at 0.5 l / min. As shown in FIG. 9, five protrusions were provided. When energized with full-wave rectification at 50 Hz and 4 A, the dissolved hydrogen concentration was 2.7 ppm. By providing the protruding portion in this way and increasing the flow rate on the surface of the cathode electrode, it is possible to further increase the dissolved hydrogen concentration.

100: Electrolyte tank 1: Anodic chamber 3: Cathode chamber 4: Cathode electrode 5: Diaphragm 51: Anoside chamber side diaphragm 52: Cathode chamber side diaphragm 6: Intermediate chamber 8: Mechanical vibration imparting part 21: Anopole pole 31: Ion exchange Resin 110: Power supply 120: Water storage tank 130: Water supply pump 140: Reverse osmotic membrane filter 150: Tap water line 160: Valve 200: Raw material water generation liquid feeding unit 301: Electrolytic surface 302: Raw material water supply line 303: Reduced water discharge line 304: Raw material water supply manifold 305: Reduced water discharge manifold 306: Raw material water inlet 307: Reduced water outlet 400: Cathode chamber frame

Claims (8)

An anode chamber, a cathode chamber, a diaphragm which is a fluorine-based ion exchange film arranged between the anode chamber and the cathode chamber, and a porous anode electrode arranged so as to be in contact with the diaphragm in the anode chamber. An electrolytic cell having a plurality of openings and having a porous cathode electrode arranged in the cathode chamber.
A current having an AC component having an average current value of 10 kHz or less is zero or more is applied to the porous cathode electrode, and water is electrolytically reduced between the diaphragm and the porous cathode electrode to generate hydrogen. It is equipped with a concentration reduction suppressing part that generates reduced water.
The cathode chamber
The surface facing the porous cathode electrode and
A plurality of protrusions protruding from the facing surface toward the porous cathode electrode and having a tip in contact with the porous cathode electrode.
Each discharges water from a supply opening located between the protrusions on the facing surface, and supplies the water between the diaphragm and the porous cathode electrode through the opening of the porous cathode electrode. With multiple source water supply units
Each is a plurality of reduced water discharge portions having discharge openings located between the protrusions on the facing surface and adjacent to the supply opening of the raw material water supply portion via the protrusion, and the diaphragm. The reduced water generated between the and the porous cathode electrode flows into each of the discharge openings through the opening of the porous cathode electrode, and flows out of the cathode chamber through each of the reduced water discharge portions. A reduced water production apparatus including a plurality of reduced water discharge units. In the apparatus according to claim 1,
A reduced water production apparatus in which a current having an alternating current component having an average current value of 10 kHz or less is zero or more is a current having an alternating current component having a minimum current value of zero or more. In the apparatus according to claim 1 or 2,
A reduced water production apparatus in which a current having an alternating current component having an average current value of 10 kHz or less is zero or more is an alternating current that has been half-wave rectified or full-wave rectified. In the apparatus according to any one of claims 1 to 3.
A reduced water production apparatus in which the distance between the cathode electrode and the diaphragm in a direction orthogonal to the diaphragm is 1 mm or less. An anode chamber, a cathode chamber, a diaphragm which is a fluorine-based ion exchange film arranged between the anode chamber and the cathode chamber, and a porous anode electrode arranged so as to be in contact with the diaphragm in the anode chamber. A porous cathode electrode having a plurality of openings and arranged in the cathode chamber is provided, the cathode chamber is on a surface facing the porous cathode electrode, and the tip contacts the porous cathode electrode. A plurality of protruding portions, a plurality of raw material water supply portions each having a supply opening located between the protruding portions on the facing surface, and the above-mentioned raw material water supply portions between the protruding portions on the facing surface and each of the raw material water supply portions. A method for producing hydrogen-containing reduced water by an electrolytic tank including a supply opening and a reduced water discharge portion having a discharge opening at a position adjacent to each other via the protrusion.
Water is discharged from each of the supply openings, and the water is supplied between the diaphragm and the porous cathode electrode through the opening of the porous cathode electrode.
A current having an AC component having an average current value of 10 kHz or less is zero or more is applied to the porous cathode electrode, and the water is electrolytically reduced between the diaphragm and the porous cathode electrode to generate hydrogen. To generate reduced water,
This includes flowing the reduced water into the reduced water discharge portions through the openings and the discharge openings of the porous cathode electrode, and causing the reduced water to flow out of the cathode chamber through the reduced water discharge portions. , A method for producing reduced water containing hydrogen. In the method according to claim 5,
A method for producing reduced water, wherein a current having an alternating current component having an average current value of 10 kHz or less is zero or more is a current having an alternating current component having a minimum current value of zero or more. In the method according to claim 5 or 6,
A method for producing reduced water in which a current having an alternating current component having an average current value of 10 kHz or less is zero or more is an alternating current that is half-wave rectified or full-wave rectified. In the method according to any one of claims 5 to 7.
A method for producing reduced water for supplying water between the cathode electrode and the cathode electrode in the electrolytic cell in which the distance between the cathode electrode and the diaphragm in the direction orthogonal to the diaphragm is 1 mm or less.

Images