Water electrolysis device including an electrolyte correction unit equipped with a diaphragm

Abstract

The present invention relates to a water electrolysis device including an electrolyte correcting unit having a diaphragm. The electrolyte correcting unit includes a diaphragm for eliminating a concentration difference in the electrolyte, thereby preventing the gas composition in a gas phase region of the water electrolysis device from reaching an explosion limit. Furthermore, even when the electrolyte discharged from the positive electrode chamber and the electrolyte discharged from the negative electrode chamber are circulated independently, no liquid level difference due to a concentration difference between the electrolytes is generated. This eliminates the need for an additional device for eliminating this, and solves the problem of reduced processability due to reinjection of the electrolyte and stabilization of operation.

Description

[Technical Field]

[0001] The present invention relates to a water electrolysis device including an electrolyte correction unit equipped with a diaphragm. [Background technology]

[0002] Water electrolysis, a representative hydrogen production technology, is a technology that directly produces hydrogen from water using electrical energy, and can produce high-purity hydrogen in an environmentally friendly manner. Water electrolysis technologies are classified into alkaline water electrolysis, polymer electrolyte water electrolysis, and solid oxide water electrolysis.

[0003] Among these water electrolysis technologies, alkaline water electrolysis has the advantage of being able to produce large amounts of hydrogen inexpensively.An alkaline water electrolysis system consists of an electrolytic cell that produces hydrogen, a gas-liquid separator that separates the gaseous hydrogen or oxygen discharged from the electrolytic cell from the electrolyte, an electrolyte storage tank that stores the liquid phase discharged from the gas-liquid separator and reintroduces it into the electrolytic cell, and an operating device (Balance of Plant) that appropriately supplies the electrolyte and controls and manages the power.

[0004] The electrolytic cell comprises an electrolyte, a separator, and electrodes, a positive electrode (anode) and a negative electrode (cathode), and the following reaction occurs at the positive electrode and the negative electrode:

[0005] Positive electrode: 2OH - →1 / 2O2+H2O+2e -

[0006] Negative electrode: 2H2O+2e - →H2+2OH -

[0007] The electrolyte solution containing dissolved oxygen gas produced by the reaction in the cathode chamber of the electrolytic cell is separated into oxygen gas and electrolyte through a cathode-side gas-liquid separator, and the electrolyte solution containing dissolved hydrogen gas produced by the reaction in the anode chamber of the electrolytic cell is separated into hydrogen gas and electrolyte through an anode-side gas-liquid separator.

[0008] However, the production of hydrogen using alkaline water electrolysis presents a problem of dissolved gas. Specifically, the electrolyte recovered from the cathode chamber of the electrolytic cell contains a portion of dissolved oxygen gas generated by the cathode reaction, and the electrolyte recovered from the anode chamber contains a portion of dissolved hydrogen gas generated by the anode reaction. Here, "oxygen gas" and "hydrogen gas" dissolved in the electrolyte encompass both the state in which oxygen gas and hydrogen gas are dissolved in the electrolyte and the state in which oxygen gas and hydrogen gas remain in the form of fine bubbles. Because the electrolyte recovered from the cathode chamber and the electrolyte recovered from the anode chamber are mixed in the electrolyte storage tank, both oxygen gas and hydrogen gas are dissolved in the electrolyte in the electrolyte storage tank. The oxygen gas and hydrogen gas dissolved in the electrolyte in the electrolyte storage tank are gradually released into the gas phase, gradually increasing the concentrations of oxygen gas and hydrogen gas in the upper gas phase of the electrolyte storage tank. Therefore, during continuous operation of the water electrolysis device, the gas composition in the upper gas phase of the electrolyte storage tank may reach an explosive limit.

[0009] Patent Document 1, which relates to a water electrolysis device that generates hydrogen gas, describes a water electrolysis device that includes a positive electrode chamber that accommodates a positive electrode and generates positive electrode gas, a negative electrode chamber that accommodates a negative electrode and generates hydrogen gas, a diaphragm that separates the positive electrode chamber from the negative electrode chamber, and a positive electrode side circulation line that discharges electrolyte from the positive electrode chamber and returns it to the positive electrode chamber, wherein the positive electrode side circulation line connects a positive electrode side gas-liquid separator that separates the cathode gas from the electrolyte, and the positive electrode chamber and the positive electrode side gas-liquid separator, and the electrolyte and the positive electrode gas are discharged from the positive electrode chamber and sent to the positive electrode side gas-liquid separator. and a cathode-side discharge line connecting the cathode chamber and the cathode-side gas-liquid separator, the cathode-side supply line discharging the electrolyte from the cathode-side gas-liquid separator and delivering it to the cathode chamber, the cathode gas delivery line connecting the cathode-side gas-liquid separator to a gas phase region in which the dissolved hydrogen gas exists in a gas phase and the hydrogen gas and the cathode gas are mixed, the cathode gas delivery line delivering at least a portion of the cathode gas to the gas phase region, and the hydrogen gas concentration in the gas phase region being below the lower explosion limit. Patent Document 1 discloses that a water electrolysis device having the configuration described above can eliminate the possibility of trace amounts of hydrogen gas gradually accumulating in an electrolyte circulation line and reaching the explosion limit of hydrogen.

[0010] However, Patent Document 1 describes that the gas discharged from the gas phase region of the electrolyte storage tank is released outside the system, and when the gas in the gas phase region of the electrolyte storage tank is purged using the positive electrode gas and then discharged, there is a problem in that it is difficult to obtain a highly pure gas even if the discharged gas is recovered.

[0011] On the other hand, when the electrolyte recovered in the positive electrode chamber and the electrolyte recovered in the negative electrode chamber are stored in separate electrolyte storage tanks and circulated, there is a problem that a difference in the concentration of the electrolyte present in the positive electrode side electrolyte storage tank and the negative electrode side electrolyte storage tank occurs due to the difference in the number of moles consumed in the positive electrode reaction and the negative electrode reaction.

[0012] When additional communication pipes are installed between the liquid phase regions of the positive electrode side electrolyte storage tank and the negative electrode side electrolyte storage tank in order to prevent a difference in the concentration of the electrolyte present in the positive electrode side electrolyte storage tank and the negative electrode side electrolyte storage tank, the electrolyte flowing in through the communication pipe contains dissolved gas, and there is a risk that the gas composition in the gas phase region of the storage tank into which the electrolyte flows in through the communication pipe will reach the explosion limit.

[0013] Therefore, there is a need for a water electrolysis device that prevents the gas composition in the gas phase region of the electrolyte storage tank from reaching the explosion limit, and that does not cause a difference in electrolyte concentration even when the electrolyte discharged from the positive electrode chamber and the electrolyte discharged from the negative electrode chamber are circulated independently. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] Japanese Patent Application Publication No. 2017-039982 Summary of the Invention [Problem to be solved by the invention]

[0015] The present invention provides a water electrolysis device that prevents the gas composition in the gas phase region of the water electrolysis device from reaching an explosion limit, and that does not cause a difference in electrolyte concentration even when the electrolyte discharged from the positive electrode chamber and the electrolyte discharged from the negative electrode chamber are circulated independently. [Means for solving the problem]

[0016] The present invention provides a water electrolysis device comprising an electrolytic cell including a positive electrode chamber and an negative electrode chamber separated by a partition wall; an electrolyte correction section including a positive electrode chamber electrolyte storage section and an negative electrode chamber electrolyte storage section, the positive electrode chamber electrolyte storage section and the negative electrode chamber electrolyte storage section being separated by a partition wall; a positive electrode circulation line connecting the positive electrode chamber of the electrolytic cell with the positive electrode chamber electrolyte storage section of the electrolyte correction section; and a negative electrode circulation line connecting the negative electrode chamber of the electrolytic cell with the negative electrode chamber electrolyte storage section of the electrolyte correction section.

[0017] In one embodiment, the fuel cell may further include a positive electrode gas-liquid separator provided in the positive electrode circulation line; and a negative electrode gas-liquid separator provided in the negative electrode circulation line.

[0018] In one embodiment, the positive electrode side gas-liquid separator may be provided at the rear end of the positive electrode chamber of the electrolytic cell and the front end of the positive electrode chamber electrolyte accommodating portion of the electrolyte correcting portion along the positive electrode circulation line, and the negative electrode side gas-liquid separator may be provided at the rear end of the negative electrode chamber of the electrolytic cell and the front end of the negative electrode chamber electrolyte accommodating portion of the electrolyte correcting portion along the negative electrode circulation line.

[0019] In one embodiment, the positive electrode side gas-liquid separator may be provided at the rear end of the positive electrode chamber electrolyte accommodating portion of the electrolyte correcting portion and the front end of the positive electrode chamber of the electrolytic cell along the positive electrode circulation line, and the negative electrode side gas-liquid separator may be provided at the rear end of the negative electrode chamber electrolyte accommodating portion of the electrolyte correcting portion and the front end of the negative electrode chamber of the electrolytic cell along the negative electrode circulation line.

[0020] In one example, the membrane may be permeable to electrolyte and ions, but impermeable to gases.

[0021] In one embodiment, the membrane may be a porous membrane.

[0022] As an example, the membrane may be a cation exchange membrane or an anion exchange membrane.

[0023] In one embodiment, a plurality of the diaphragms may be provided, and the positive electrode chamber electrolyte receiving portions and the negative electrode chamber electrolyte receiving portions may be arranged alternately.

[0024] In one embodiment, when the positive electrode chamber electrolyte receiving portion and the negative electrode chamber electrolyte receiving portion are alternately arranged, the plurality of diaphragms alternately arranged in accordance with the direction in which the receiving portions are alternately arranged may be cation exchange membranes and anion exchange membranes alternately provided.

[0025] In one embodiment, a positive electrode and a negative electrode may be provided at both ends of the electrolyte compensation unit, and a diaphragm may be disposed between the positive electrode and the negative electrode.

[0026] In one embodiment, the diaphragm may be a cation exchange membrane or an anion exchange membrane, and the cation exchange membrane may be located on a side of the positive electrode chamber electrolyte-accommodating portion adjacent to the positive electrode and the anion exchange membrane may be located on a side of the negative electrode chamber electrolyte-accommodating portion adjacent to the positive electrode and the anion exchange membrane may be located on a side of the negative electrode chamber electrolyte-accommodating portion adjacent to the positive electrode and the cation exchange membrane may be located on a side of the negative electrode chamber electrolyte-accommodating portion adjacent to the negative electrode.

[0027] In one embodiment, a water supply pipe and a water supply pump for supplying water may be further provided to at least one of the anode chamber of the electrolytic cell, the anode chamber electrolyte storage unit of the electrolyte compensation unit, and the anode circulation line.

[0028] As an example, the negative electrode gas-liquid separator may further include a water supply pipe and a water supply pump for supplying water. [Effects of the Invention]

[0029] The present invention provides an electrolyte correcting unit including a diaphragm for eliminating a concentration difference between electrolytes, thereby preventing the gas composition in the gas phase region of the water electrolysis device from reaching an explosion limit. Furthermore, even when the electrolytes discharged from the cathode chamber and the anode chamber are circulated independently, no difference in electrolyte concentration occurs. This eliminates the need for an additional device for eliminating this difference, and solves problems of reduced processability due to reinjection of electrolyte and operational stabilization. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a configuration diagram showing an electrolytic cell, an electrolyte correction unit, a positive electrode circulation line, and a negative electrode circulation line of a water electrolysis device according to the present invention. [Figure 2] 1 is a configuration diagram of a water electrolysis device according to an embodiment of the present invention. [Figure 3] FIG. 10 is a configuration diagram of a water electrolysis device according to another embodiment of the present invention. [Figure 4] 3 is a schematic diagram showing the configuration of a diaphragm inside an electrolyte correction unit of the present invention. FIG. [Figure 5]1 is a schematic diagram showing a configuration in which a plurality of cation exchange membranes are configured inside an electrolyte solution correction unit of the present invention. [Figure 6] 1 is a schematic diagram showing a configuration in which a plurality of anion exchange membranes are configured inside an electrolyte solution correction unit of the present invention. [Figure 7] 1 is a schematic diagram showing a configuration in which a plurality of cation exchange membranes and anion exchange membranes are configured inside an electrolyte correction unit of the present invention. [Figure 8] 3 is a schematic diagram showing a configuration in which electrodes are formed in the electrolyte correction section of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0031] The present invention can be modified in various ways and can have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail in the detailed description.

[0032] However, it should be understood that this is not intended to limit the invention to any particular embodiment, but rather to include all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

[0033] In the present invention, the terms "comprise," "include," "comprise," or "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0034] Therefore, the configurations illustrated in the embodiments described in this specification are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and there may be various equivalents and modifications that can replace them at the time of this application.

[0035] Referring to FIG. 1 , the present invention provides a water electrolysis device 1 including an electrolytic cell 100 including a cathode chamber 130 and an anode chamber 150 separated by a partition 110, an electrolyte correction section 400 including a cathode chamber electrolyte reservoir 410 and an anode chamber electrolyte reservoir 420, the cathode chamber electrolyte reservoir 410 and the anode chamber electrolyte reservoir 420 being separated by a diaphragm 500, a positive electrode circulation line 250 connecting the positive electrode chamber 130 of the electrolytic cell with the positive electrode chamber electrolyte reservoir 410 of the electrolyte correction section, and a negative electrode circulation line 350 connecting the anode chamber 150 of the electrolytic cell with the anode chamber electrolyte reservoir 420 of the electrolyte correction section 400.

[0036] The water electrolysis device 1 is a device that produces oxygen gas and hydrogen gas by electrolysis using an electrolyte.

[0037] The electrolytic cell 100 includes a positive electrode chamber 130 including a positive electrode 140 for generating oxygen gas and an negative electrode chamber 150 including a negative electrode 160 for generating hydrogen gas. The positive electrode chamber 130 and the negative electrode chamber 150 are separated by a partition wall 110.

[0038] The partition wall 110 separates the positive electrode chamber 130 from the negative electrode chamber 150 and has gas barrier properties, and its shape and material are not particularly limited.

[0039] The partition wall 110 may be a plate having a predetermined thickness, and preferably has high electrolyte permeability, high ion permeability, and high gas barrier property. The material of the partition wall may include polymer resin fibers and inorganic compounds, and may be, for example, a porous polymer film.

[0040] The positive electrode chamber 130 and the negative electrode chamber 150 each have a space surrounded by a partition wall 110 and an outer frame 120, through which the electrolyte flowing in from the electrolyte correcting unit 400 passes.

[0041] At this time, the following reaction occurs between the positive electrode in the positive electrode chamber and the negative electrode in the negative electrode chamber.

[0042] Positive electrode: 2OH -→1 / 2O2+H2O+2e -

[0043] Negative electrode: 2H2O+2e - →H2+2OH -

[0044] That is, in the positive electrode chamber, hydroxide thing ions (OH - ) is consumed, oxygen gas is generated, and hydroxide thing ions (OH - ) is produced while hydrogen gas is released.

[0045] In this case, the production of hydrogen using alkaline water electrolysis involves the problem of dissolved gas: the electrolyte discharged from the positive electrode chamber of the electrolytic cell contains some dissolved oxygen gas generated by the positive electrode reaction, and the electrolyte discharged from the negative electrode chamber contains some dissolved hydrogen gas generated by the negative electrode reaction.

[0046] In the present invention, the oxygen gas and hydrogen gas dissolved in the electrolyte solution is a concept that includes a state in which oxygen gas and hydrogen gas are dissolved in the electrolyte solution and a state in which oxygen gas and hydrogen gas remain in the form of fine bubbles.

[0047] Therefore, if the concentrations of oxygen gas and hydrogen gas dissolved in the electrolyte exceed a predetermined range (explosive range) during the circulation of the electrolyte while the water electrolysis device is in operation, there is a risk that the water electrolysis device may explode.

[0048] The present invention has a technical feature in that an electrolyte correction unit 400 is provided at the front or rear end of the electrolytic cell 100 in order to adjust the concentrations of oxygen gas and hydrogen gas dissolved in the electrolyte to below the explosion limit.

[0049] The present invention may further include a cathode gas-liquid separator 200 provided in the cathode circulation line 250 and an anode gas-liquid separator 300 provided in the anode circulation line 350 .

[0050] In one embodiment, the cathode-side gas-liquid separator 200 is provided along the cathode circulation line 250 between the cathode chamber 130 of the electrolytic cell and the cathode chamber electrolyte reservoir 410 of the electrolyte compensation unit, specifically, at the rear end of the cathode chamber 130 of the electrolytic cell and the front end of the cathode chamber electrolyte reservoir 410 of the electrolyte compensation unit, along the cathode circulation line 250. The anode-side gas-liquid separator 300 may be provided along the anode circulation line 350 between the anode chamber 150 of the electrolytic cell and the anode chamber electrolyte reservoir 420 of the electrolyte compensation unit, specifically, at the rear end of the anode chamber 150 of the electrolytic cell and the front end of the anode chamber electrolyte reservoir 420 of the electrolyte compensation unit, along the anode circulation line 350.

[0051] Referring to FIG. 2 , in this embodiment, the positive electrode circulation line 250 may be divided into a positive electrode return pipe 210 that connects the positive electrode chamber 130 and the positive electrode side gas-liquid separator 200, a positive electrode electrolyte return pipe 230 that connects the positive electrode side gas-liquid separator 200 and the positive electrode chamber electrolyte container 410, and a positive electrode electrolyte supply pipe 440 that connects the positive electrode chamber electrolyte container 410 and the positive electrode chamber 130.

[0052] In addition, the positive electrode side gas-liquid separator 200 includes a liquid phase region 201 located at the bottom and a gas phase region 202 located above the liquid phase region, and the negative electrode side gas-liquid separator 300 includes a liquid phase region 301 located at the bottom and a gas phase region 302 located above the liquid phase region.

[0053] In addition, the anode circulation line 350 may be divided into an anode recovery pipe 310 that connects the anode chamber 150 and the anode-side gas-liquid separator 300, an anode electrolyte recovery pipe 330 that connects the anode-side gas-liquid separator 300 and the anode chamber electrolyte container 420, and an anode electrolyte supply pipe 450 that connects the anode chamber electrolyte container 420 and the anode chamber 150.

[0054] Specifically, the cathode-side gas-liquid separator 200 is connected to the cathode chamber 130 through a cathode recovery pipe 210 and separates the electrolyte and oxygen gas discharged from the cathode chamber 130 into gas and liquid. The anode-side gas-liquid separator 300 is connected to the anode chamber 150 through a cathode recovery pipe 310 and separates the electrolyte and hydrogen gas discharged from the anode chamber 150 into gas and liquid.

[0055] In this case, the positive electrode recovery pipe 210 and the negative electrode recovery pipe 310 may be connected to the upper portions of the positive electrode side gas-liquid separator 200 and the negative electrode side gas-liquid separator 300 .

[0056] When the cathode recovery pipe 210 and the anode recovery pipe 310 are connected to the upper parts of the cathode-side gas-liquid separator 200 and the anode-side gas-liquid separator 300, the time for the electrolyte containing dissolved gases discharged from the electrolytic cell to fall from inside the gas-liquid separator to the liquid surface is increased, thereby increasing the gas-liquid separation efficiency.

[0057] The electrolyte correcting unit 400 communicates with the cathode gas-liquid separator 200 through a cathode electrolyte recovery pipe 230 and with the anode gas-liquid separator 300 through an anode electrolyte recovery pipe 330, and a diaphragm 500 is provided inside the electrolyte correcting unit 400.

[0058] Specifically, the electrolyte correction unit 400 includes a cathode chamber electrolyte accommodating unit 410 that communicates with the cathode side gas-liquid separator 200 through a cathode electrolyte recovery pipe 230, and an anode chamber electrolyte accommodating unit 420 that communicates with the anode side gas-liquid separator 300 through an anode electrolyte recovery pipe 330, and the cathode chamber electrolyte accommodating unit 410 and the anode chamber electrolyte accommodating unit 420 are separated by a diaphragm 500.

[0059] At this time, the positive electrode electrolyte recovery pipe 230 communicates with the liquid phase region 201 of the positive electrode gas-liquid separator 200 , and the negative electrode electrolyte recovery pipe 330 communicates with the liquid phase region 301 of the negative electrode gas-liquid separator 300 .

[0060] The electrolyte correction unit 400 accommodates the electrolyte present in the liquid phase regions 201, 301 of the cathode-side gas-liquid separator 200 and the anode-side gas-liquid separator 300, and supplies the electrolyte to the cathode chamber 130 and the anode chamber 150 of the electrolytic cell 100 via a cathode electrolyte supply pipe 440 communicating with the cathode chamber electrolyte accommodation unit 410 and an anode electrolyte supply pipe 450 communicating with the anode chamber electrolyte accommodation unit 420, respectively.

[0061] In addition, the positive electrode electrolyte supply pipe 440 and the negative electrode electrolyte supply pipe 450 may be provided with a circulation pump 600 for supplying the electrolyte of the electrolyte compensation unit 400 to the electrolytic cell 100. In this case, the circulation pump 600 may be configured as a single circulation pump after the positive electrode electrolyte supply pipe 440 and the negative electrode electrolyte supply pipe 450 are combined into one supply pipe.

[0062] The electrolyte solution flowing from the cathode gas-liquid separator 200 and the electrolyte solution flowing from the anode gas-liquid separator 300 can be separated into two by the diaphragm 500 provided in the electrolyte solution correcting unit 400 within the electrolyte solution correcting unit.

[0063] The membrane 500 may have different permeabilities for liquid and gas to allow ions and electrolyte to pass through and isolate hydrogen gas and oxygen gas generated in the electrolytic cell.

[0064] Specifically, the membrane contains pores, and the permeability of liquids and gases can be varied by adjusting the size of the pores, or by adjusting the size of the polymer resin fibers or inorganic particles.

[0065] For example, the size of the pores, polymer resin fibers, or inorganic particles may be 0.01 μm to 10 μm.

[0066] A membrane having the above properties can be achieved by adjusting the pore diameter, surface area, hydrophilicity, and pore structure. For example, a polymer porous membrane, an inorganic porous membrane, a woven fabric, or a nonwoven fabric can be used.

[0067] The membrane may be permeable to electrolyte and ions, but impermeable to gases.

[0068] The gas impermeability is defined as a gas permeability of 10 l / min.cm when measured at a pressure of 5 bar. 3 For example, the membrane may have a gas permeability of 7 l / min.cm when measured at a pressure of 5 bar. 3Less than or equal to 5 l / min.cm 3 It can be the following:

[0069] The material of the membrane 500 may be at least one selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, polysulfone, polyphenylene sulfide, polyethersulfone, polyphenylsulfone, polyvinylidene fluoride, polyacrylonitrile, polyethylene oxide, polymethyl methacrylate, polyamide, polyetheretherketone, sulfonated polyetheretherketone, polyimide, and copolymers thereof.

[0070] The membrane 500 may be a porous membrane and may have a three-dimensional porous network.

[0071] The size of the pores in the porous membrane is not particularly limited as long as it can be controlled to be permeable to the electrolyte and ions and impermeable to gas, and may be, for example, 0.01 μm to 10 μm.

[0072] The diaphragm 500 may be an ion exchange membrane, which may be an anion exchange membrane or a cation exchange membrane. Examples of the ion exchange membrane include a fluorine-containing ion exchange membrane. In this case, the ion exchange membrane may be porous or non-porous.

[0073] By providing the diaphragm 500 as described above in the electrolyte correction unit 400, the present invention can prevent the oxygen gas generated at the positive electrode and the hydrogen gas generated at the negative electrode from mixing in the electrolyte correction unit, thereby maintaining the concentrations of hydrogen gas in oxygen gas and oxygen gas in hydrogen gas below the explosive range.

[0074] That is, in the water electrolysis device according to the present invention, the electrolyte circulating through the positive electrode chamber 130, positive electrode recovery pipe 210, positive electrode side gas-liquid separator 200, positive electrode electrolyte recovery pipe 230, positive electrode chamber electrolyte container 410, and positive electrode electrolyte supply pipe 440 of the electrolytic cell 100, and the electrolyte circulating through the negative electrode chamber 150, negative electrode recovery pipe 310, negative electrode side gas-liquid separator 300, negative electrode electrolyte recovery pipe 330, negative electrode chamber electrolyte container 420, and negative electrode electrolyte supply pipe 450 of the electrolytic cell 100 circulate independently of each other.

[0075] Therefore, in the water electrolysis device according to the present invention, the oxygen and hydrogen gases dissolved in the electrolytes in the positive electrode chamber and the negative electrode chamber, respectively, are not mixed, and the concentration of hydrogen gas can be maintained within the explosive range.

[0076] In addition, in the positive electrode chamber 130 and the negative electrode chamber 150 of the electrolytic cell 100, hydroxide thing ions (OH - ) is consumed and produced, which creates a concentration gradient between the electrolytes discharged from the cathode chamber and the anode chamber, resulting in the problem of hydrogen gas and oxygen gas mixing during the process of correcting the difference in electrolyte concentration. However, the present invention provides an electrolyte correcting unit with a diaphragm 500 that is ion permeable, so it can correct the difference in concentration between the electrolytes discharged from the cathode chamber 130 and the anode chamber 150. This solves the problems of the need for additional equipment due to the difference in electrolyte levels and the reduced processability due to the need to re-inject the electrolyte and stabilize operation.

[0077] In addition, the electrolyte correcting unit 400 allows the electrolyte flowing in from the positive electrode gas-liquid separator 200 and the electrolyte flowing in from the negative electrode gas-liquid separator 300 to flow alternately across a plurality of diaphragms.

[0078] That is, the electrolyte correcting unit 400 may be provided with a plurality of diaphragms, thereby forming a plurality of positive electrode chamber electrolyte receiving units 410 and anode chamber electrolyte receiving units 420, and at this time, the positive electrode chamber electrolyte receiving units 410 and the anode chamber electrolyte receiving units 420 may be arranged alternately.

[0079] As described above, when the positive electrode chamber electrolyte storage section 410 and the negative electrode chamber electrolyte storage section 420 are formed with a plurality of diaphragms sandwiched therebetween, the relatively low-concentration electrolyte flowing in from the positive electrode-side gas-liquid separator 200 and the relatively high-concentration electrolyte flowing in from the negative electrode-side gas-liquid separator 300 exchange ions with each other, thereby eliminating the concentration difference.

[0080] In this case, the plurality of membranes may be cation exchange membranes or anion exchange membranes, or may be formed of only cation exchange membranes or only anion exchange membranes.

[0081] The plurality of membranes may be formed by alternating cation exchange membranes and anion exchange membranes.

[0082] In this case, when the positive electrode chamber electrolyte receiving portion 410 and the negative electrode chamber electrolyte receiving portion 420 are alternately arranged, the plurality of membranes alternately arranged in the direction in which the receiving portions are alternately arranged may be provided with cation exchange membranes and anion exchange membranes alternately.

[0083] In addition, a positive electrode and a negative electrode may be provided at both ends of the electrolyte compensation unit 400, and a diaphragm may be disposed between the positive electrode and the negative electrode. When a power source is applied to the electrodes to generate an electromotive force difference, the ion exchange rate increases, thereby improving productivity.

[0084] Specifically, the diaphragm may be a cation exchange membrane or an anion exchange membrane, and the cation exchange membrane may be located on a side of the cathode chamber electrolyte-accommodating portion adjacent to the cathode and the anion exchange membrane may be located on a side of the anode chamber electrolyte-accommodating portion adjacent to the cathode and the anion exchange membrane may be located on a side of the anode chamber electrolyte-accommodating portion adjacent to the cathode and the cation exchange membrane may be located on a side of the anode chamber electrolyte-accommodating portion adjacent to the cathode. Also, the battery may be configured so that a separate electrolyte is supplied to the space where the cathode and the anode are provided.

[0085] The electrolyte used in the present invention may be an alkaline aqueous solution in which an alkaline salt is dissolved, for example, an aqueous NaOH solution or an aqueous KOH solution.

[0086] In this case, the concentration of the alkali salt may be 1% to 50% by weight, for example, when the electrolyte is an aqueous NaOH solution, the NaOH content may be 1% to 20% by weight or 10% to 15% by weight, or when the electrolyte is an aqueous KOH solution, the KOH content may be 20% to 50% by weight, for example, 25% to 40% by weight or 25% to 35% by weight.

[0087] In addition, the anode chamber 150 of the electrolytic cell, the anode chamber electrolyte storage unit 420 of the electrolyte correction unit, the anode side gas-liquid separator 300, and the anode circulation line 350 may be provided with a water supply pipe and a water supply pump for supplying water from a water storage tank.

[0088] In another embodiment of the present invention, the positive electrode side gas-liquid separator 200 may be provided at the rear end of the positive electrode chamber electrolyte accommodating portion 410 of the electrolyte compensation portion and the front end of the positive electrode chamber 130 of the electrolytic cell along the positive electrode circulation line 250, and the negative electrode side gas-liquid separator 300 may be provided at the rear end of the negative electrode chamber electrolyte accommodating portion 420 of the electrolyte compensation portion and the front end of the negative electrode chamber 150 of the electrolytic cell along the negative electrode circulation line 350.

[0089] Referring to FIG. 3 , in the above embodiment, the positive electrode circulation line 250 may be divided into a second positive electrode return pipe 211 that connects the positive electrode chamber 130 and the positive electrode chamber electrolyte container 410, a second positive electrode electrolyte return pipe 231 that connects the positive electrode chamber electrolyte container 410 and the positive electrode side gas-liquid separator 200, and a second positive electrode electrolyte supply pipe 441 that connects the positive electrode side gas-liquid separator 200 and the positive electrode chamber 130.

[0090] In addition, the anode circulation line 350 may be divided into a second anode return pipe 311 that connects the anode chamber 150 and the anode chamber electrolyte container 420, a second anode electrolyte return pipe 331 that connects the anode chamber electrolyte container 420 and the anode side gas-liquid separator 300, and a second anode electrolyte supply pipe 451 that connects the anode side gas-liquid separator 300 and the anode chamber 150.

[0091] The positive electrode chamber electrolyte storage section 410 communicates with the positive electrode chamber 130 through a second positive electrode recovery pipe 211 and stores the electrolyte and oxygen gas discharged from the positive electrode chamber 130. The negative electrode chamber electrolyte storage section 420 communicates with the negative electrode chamber 150 through a second negative electrode recovery pipe 311 and stores the electrolyte and hydrogen gas discharged from the negative electrode chamber 150.

[0092] In the electrolyte correcting section 400 , ions of the electrolyte in the positive electrode chamber electrolyte receiving section 410 and the electrolyte in the negative electrode chamber electrolyte receiving section 420 are exchanged through the diaphragm 500 .

[0093] Through the ion exchange, the difference in concentration between the electrolyte in the positive electrode chamber electrolyte receiving portion 410 and the electrolyte in the negative electrode chamber electrolyte receiving portion 420 is eliminated.

[0094] The positive electrode chamber electrolyte container 410 communicates with the positive electrode side gas-liquid separator 200 through a second positive electrode electrolyte recovery pipe 231, and the negative electrode chamber electrolyte container 420 communicates with the negative electrode side gas-liquid separator 300 through a second negative electrode electrolyte recovery pipe 331.

[0095] The electrolyte present in the liquid phase regions of the positive electrode side gas-liquid separator 200 and the negative electrode side gas-liquid separator 300 is supplied to the positive electrode chamber 130 and the negative electrode chamber 150 of the electrolytic cell 100 through a second positive electrode electrolyte supply pipe 441 and a second negative electrode electrolyte supply pipe 451, respectively.

[0096] The embodiment according to FIG. 2 and the embodiment according to FIG. 3 differ only in that the cathode-side gas-liquid separator 200 and the anode-side gas-liquid separator 300 are located at the front or rear end of the electrolytic cell, but the main role and structure of the electrolyte correction unit 400 are common, and the main content described above can be applied in the same way.

[0097] The electrolyte according to the present invention may be KOH, and the concentration of the electrolyte may be 20 to 50%, but is not limited thereto.

[0098] The operating conditions are not particularly limited. For example, the temperature of the electrolytic solution may be 30°C to 200°C, and the current density of the electrolytic cell may be 1 kA / m 2 ~50kA / m2 The pressure of the electrolytic cell may be 0.1 MPa to 20 MPa.

[0099] Specific examples of the present invention will be presented below, but the examples described below are merely for the purpose of specifically illustrating or explaining the present invention, and the present invention is not limited thereto.

[0100] 1-1 embodiment Referring to FIG. 2 , one embodiment of the present invention includes an electrolytic cell 100 including a cathode chamber 130 and an anode chamber 150 separated by a partition wall 110, a cathode-side gas-liquid separator 200 in communication with the cathode chamber 130 via a cathode return pipe 210, an anode-side gas-liquid separator 300 in communication with the anode chamber 150 via an anode return pipe 310, and a cathode chamber electrolyte receiving portion 410 and an anode chamber electrolyte receiving portion 420 of an electrolyte correction unit 400 in communication with the cathode side gas-liquid separator 200 and the anode side gas-liquid separator 300 via a cathode electrolyte recovery pipe 230 and an anode electrolyte recovery pipe 330, respectively. A diaphragm 500 is provided inside the electrolyte correction unit 400, and electrolyte is supplied to the cathode chamber and the anode chamber of the electrolytic cell 100 via a cathode electrolyte supply pipe 440 and an anode electrolyte supply pipe 450. In this case, the positive electrode electrolyte supply pipe 440 and the negative electrode electrolyte supply pipe 450 may be provided with a circulation pump 600 .

[0101] The electrolyte may be an aqueous solution of KOH.

[0102] In the electrolytic bath 100, the following reaction occurs when an electrolyte having a molar concentration of x is supplied from the electrolyte correcting unit 400.

[0103] Positive electrode: 2OH - →1 / 2O2+H2O+2e -

[0104] Negative electrode: 2H2O+2e - →H2+2OH -

[0105] That is, in the positive electrode chamber, hydroxide thing ions (OH- ) is consumed, oxygen gas is generated, and hydroxide thing ions (OH - ) is produced, and hydrogen gas is generated. As a result, the molar concentration of the electrolyte discharged from the positive electrode chamber becomes (xa) moles, and oxygen gas is dissolved therein. Also, the molar concentration of the electrolyte discharged from the negative electrode chamber becomes (x + a) moles, and hydrogen gas is dissolved therein.

[0106] The electrolyte discharged from the positive electrode chamber 130 and the negative electrode chamber 150 moves to the positive electrode gas-liquid separator 200 and the negative electrode gas-liquid separator 300 through the positive electrode recovery pipe 210 and the negative electrode recovery pipe 310 .

[0107] In the cathode gas-liquid separator 200, oxygen gas dissolved in the electrolyte exists as a gas phase region, and the electrolyte exists as a liquid phase region, and the gas phase region may be provided with an oxygen gas discharge pipe 220 for discharging the oxygen gas to the outside of the system. In addition, the electrolyte existing in the liquid phase region flows into the cathode chamber electrolyte container 410 of the electrolyte correction unit 400 through the cathode electrolyte recovery pipe 230.

[0108] In the anode gas-liquid separator 300, the hydrogen gas dissolved in the electrolyte exists as a gas phase region, and the electrolyte exists as a liquid phase region. The gas phase region may be provided with a hydrogen gas discharge pipe 320 for discharging the hydrogen gas to the outside of the system. The electrolyte existing in the liquid phase region flows into the anode chamber electrolyte container 420 of the electrolyte correction unit 400 through the anode electrolyte recovery pipe 330.

[0109] At this time, oxygen and hydrogen gas are partially dissolved in the electrolyte present in the liquid phase region.

[0110] Referring to FIG. 4, in the electrolyte correcting unit 400, (xa) moles of electrolyte flowing in through the positive electrode electrolyte recovery pipe 230 and (x+a) moles of electrolyte flowing in through the negative electrode electrolyte recovery pipe 330 are supplied to the positive electrode chamber electrolyte receiving unit 410 and the negative electrode chamber electrolyte receiving unit 420, respectively, by the diaphragm 500.

[0111] The diaphragm 500 is an ion-permeable diaphragm that allows ions to pass through but blocks the permeation of hydrogen gas and oxygen gas generated in the electrolytic cell.

[0112] The diaphragm has a plurality of fine through-pores and has a structure that allows the electrolyte to pass through, but has gas barrier properties that prevent the hydrogen gas and oxygen gas dissolved in the electrolyte from passing through.

[0113] Therefore, since the (x+a) moles of electrolyte flowing in through the anode electrolyte recovery pipe 330 has a higher concentration than the (xa) moles of electrolyte flowing in through the cathode electrolyte recovery pipe 230, ions of the electrolyte flowing in through the anode electrolyte recovery pipe 330 move through the diaphragm to the electrolyte flowing in through the cathode electrolyte recovery pipe 230. As a result, the concentration gradient of the electrolyte in the electrolyte correction unit 400 separated by the diaphragm disappears.

[0114] In addition, the electrolyte correcting unit 400 prevents the mixing of oxygen gas and hydrogen gas by the diaphragm 500, thereby preventing the risk of explosion caused by the hydrogen gas concentration exceeding the explosive range in the oxygen gas.

[0115] 1-2 Embodiment The first embodiment is configured in the same manner as the first embodiment, except that the electrolyte correcting unit 400 includes a plurality of porous membranes.

[0116] The electrolyte correction unit 400 has n+1 electrolyte storage compartments formed by n porous diaphragms, and (xa) moles of electrolyte flowing in from the cathode-side gas-liquid separator 200 and (x+a) moles of electrolyte flowing in from the anode-side gas-liquid separator 300 alternately flow into the n+1 electrolyte storage compartments.

[0117] In this case, the positive electrode electrolyte supply pipe 440 and the negative electrode electrolyte supply pipe 450 for supplying the electrolyte from the electrolyte compensation unit 400 to the electrolytic cell 100 may each be formed as a single pipe and may have a manifold therein for smooth supply to the electrolyte reservoirs. Also, the positive electrode electrolyte supply pipe 440 and the negative electrode electrolyte supply pipe 450 may be formed as a plurality of pipes corresponding to the n+1 electrolyte reservoirs.

[0118] First to third embodiments The first embodiment is configured in the same manner as the first embodiment, except that the electrolyte compensation unit 400 uses a cation exchange membrane 510 instead of a porous membrane.

[0119] The cation exchange membrane 510 selectively allows only cations in the electrolyte to pass through, and has gas barrier properties.

[0120] At this time, inside the electrolyte correction unit 400, the cations (i.e., K + ions) move through the cation exchange membrane due to a concentration gradient to the (x+a) moles of electrolyte in the cathode chamber electrolyte storage section 410 that has flowed in from the adjacent cathode side gas-liquid separator 200. Thereafter, to maintain ion balance, anions can pass through the membrane and move, even though the cation exchange membrane has cation selectivity. That is, the anions (i.e., OH - ions) move through the cation exchange membrane to the (xa) moles of electrolyte in the adjacent positive electrode chamber electrolyte storage section 410. As a result, the concentration of the electrolyte finally discharged from the electrolyte correction section 400 becomes x moles.

[0121] First to fourth embodiments The first to fourth embodiments are configured in the same manner as the first to third embodiments, except that the electrolyte correcting unit 400 includes a plurality of cation exchange membranes 510 .

[0122] Referring to FIG. 5, the cation exchange membrane selectively allows only cations in the electrolyte to pass through and has gas barrier properties.

[0123] The electrolyte correction unit 400 has n+1 electrolyte storage compartments formed by n cation exchange membranes, and (xa) moles of electrolyte flowing in from the positive electrode side gas-liquid separator 200 and (x+a) moles of electrolyte flowing in from the negative electrode side gas-liquid separator 300 alternately flow into the n+1 electrolyte storage compartments.

[0124] At this time, inside the electrolyte correction unit 400, the cations (i.e., K + ions) move through the cation exchange membrane due to a concentration gradient to the (x+a) moles of electrolyte in the cathode chamber electrolyte storage section 410 that has flowed in from the adjacent cathode side gas-liquid separator 200. Thereafter, to maintain ion balance, anions can pass through the membrane to move, even though the cation exchange membrane has cation selectivity. That is, to maintain ion balance, anions (i.e., OH - ions) move through the ion exchange membrane to the (xa) moles of electrolyte in the adjacent positive electrode chamber electrolyte storage section 410. As a result, the concentration of the electrolyte finally discharged from the electrolyte correction section 400 becomes x moles.

[0125] In this case, the cathode electrolyte supply pipe 440 and the anode electrolyte supply pipe 450 for supplying the electrolyte from the electrolyte correcting unit 400 to the electrolytic cell 100 may each be formed as a single pipe, or the cathode electrolyte supply pipe 440 and the anode electrolyte supply pipe 450 may each be formed as a plurality of pipes corresponding to the n+1 electrolyte receiving units.

[0126] In addition, the cathode electrolyte recovery pipe 230 and the anode electrolyte recovery pipe 330 for supplying the electrolyte from the cathode gas-liquid separator 200 and the anode gas-liquid separator 300 to the electrolyte correction unit 400 may each be formed as a single pipe, or the cathode electrolyte recovery pipe 230 and the anode electrolyte recovery pipe 330 may each be formed as a plurality of pipes corresponding to the n+1 electrolyte storage units.

[0127] The electrolyte compensation unit may have a manifold inside for smooth supply and discharge of the electrolyte.

[0128] Furthermore, since the cation exchange membrane 510 has gas barrier properties, it is possible to prevent the mixing of oxygen gas and hydrogen gas, and to prevent the risk of explosion due to the concentration of hydrogen gas in oxygen gas and the concentration of oxygen gas in hydrogen gas exceeding the explosive range.

[0129] 1st to 5th embodiments The 1-5th embodiment is configured in the same manner as the 1-1th embodiment, except that the electrolyte compensation unit 400 uses an anion exchange membrane 520 instead of a porous membrane.

[0130] The anion exchange membrane 520 selectively allows only anions in the electrolyte to pass through, and has gas barrier properties.

[0131] At this time, inside the electrolyte correction unit 400, the anions (i.e., OH) of the (x+a) moles of electrolyte flowing in from the negative electrode side gas-liquid separator 300 - ions) move through the anion exchange membrane 520 due to a concentration gradient into the (x+a) moles of electrolyte solution flowing in from the adjacent positive electrode gas-liquid separator 200. Thereafter, to maintain ion balance, the anion exchange membrane has anion selectivity, but cations can also pass through the membrane and move. That is, the cations (i.e., K + ions) move through the anion exchange membrane to the (xa) moles of electrolyte flowing in from the adjacent positive electrode side gas-liquid separator 200. As a result, the concentration of the electrolyte finally discharged from the electrolyte correction unit 400 becomes x moles.

[0132] 1st to 6th embodiments The sixth embodiment is configured in the same manner as the fifth embodiment, except that the electrolyte correcting unit 400 includes a plurality of anion exchange membranes 520 .

[0133] Referring to FIG. 6, the anion exchange membrane 520 selectively allows only anions in the electrolyte to pass through, and has gas barrier properties.

[0134] The electrolyte correction unit 400 has n anion exchange membranes, which form n+1 electrolyte inflow spaces. The n+1 electrolyte inflow spaces alternately receive (xa) moles of electrolyte from the cathode gas-liquid separator 200 and (x+a) moles of electrolyte from the anode gas-liquid separator 300.

[0135] At this time, inside the electrolyte correction unit 400, the anions (i.e., OH) of the (x+a) moles of electrolyte flowing in from the negative electrode side gas-liquid separator 300 - ions) move through the anion exchange membrane due to a concentration gradient into the (x+a) moles of electrolyte solution flowing in from the adjacent positive electrode gas-liquid separator 200. Thereafter, to maintain ion balance, cations can pass through the membrane and move, even though the anion exchange membrane has anion selectivity. That is, the cations (i.e., K + ions) move through the ion exchange membrane to the (xa) moles of electrolyte flowing in from the adjacent positive electrode side gas-liquid separator 200. As a result, the concentration of the electrolyte finally discharged from the electrolyte correction unit 400 becomes x moles.

[0136] In this case, the cathode electrolyte supply pipe 440 and the anode electrolyte supply pipe 450 for supplying the electrolyte from the electrolyte correcting unit 400 to the electrolytic cell 100 may each be formed as a single pipe, or the cathode electrolyte supply pipe 440 and the anode electrolyte supply pipe 450 may each be formed as a plurality of pipes corresponding to the n+1 electrolyte receiving units.

[0137] In addition, the cathode electrolyte recovery pipe 230 and the anode electrolyte recovery pipe 330 for supplying the electrolyte from the cathode gas-liquid separator 200 and the anode gas-liquid separator 300 to the electrolyte correction unit 400 may each be formed as a single pipe, or the cathode electrolyte recovery pipe 230 and the anode electrolyte recovery pipe 330 may each be formed as a plurality of pipes corresponding to the n+1 electrolyte storage units.

[0138] The electrolyte compensation unit may have a manifold inside for smooth supply and discharge of the electrolyte.

[0139] Furthermore, since the anion exchange membrane 520 has gas barrier properties, it is possible to prevent the mixing of oxygen gas and hydrogen gas, and to prevent the risk of explosion caused by the concentration of hydrogen gas in oxygen gas and the concentration of oxygen gas in hydrogen gas exceeding the explosive range.

[0140] 1st to 7th embodiments 7, in the first to seventh embodiments, a plurality of cation exchange membranes 510 and a plurality of anion exchange membranes 520 are alternately provided in the electrolyte correction unit 400. In this case, the cation exchange membranes selectively allow only cations in the electrolyte to pass through, and the anion exchange membranes selectively allow only anions in the electrolyte to pass through.

[0141] The electrolyte correction unit 400 has n+1 electrolyte storage compartments formed by n cation exchange membranes 510 and anion exchange membranes 520, and (xa) moles of electrolyte flowing in from the positive electrode side gas-liquid separator 200 and (x+a) moles of electrolyte flowing in from the negative electrode side gas-liquid separator 300 alternately flow into the n+1 electrolyte storage compartments.

[0142] At this time, inside the electrolyte correction unit 400, the anions (i.e., OH) of the (x+a) moles of electrolyte in the anode chamber electrolyte storage unit 420 that flowed in from the anode side gas-liquid separator 300 - ions) move through the anion exchange membrane 520 due to a concentration gradient to the (xa) moles of electrolyte in the cathode chamber electrolyte storage section 410 that has flowed in from the adjacent cathode side gas-liquid separator 200. Also, the cations (i.e., K + ions) move through the cation exchange membrane 510 to the (xa) moles of electrolyte in the adjacent positive electrode chamber electrolyte storage section 410. As a result, the concentration of the electrolyte finally discharged from the electrolyte correction section 400 becomes x moles.

[0143] In this case, the cathode electrolyte supply pipe 440 and the anode electrolyte supply pipe 450 for supplying the electrolyte from the electrolyte correcting unit 400 to the electrolytic cell 100 may each be formed as a single pipe, or the cathode electrolyte supply pipe 440 and the anode electrolyte supply pipe 450 may each be formed as a plurality of pipes corresponding to the n+1 electrolyte receiving units.

[0144] In addition, the cathode electrolyte recovery pipe 230 and the anode electrolyte recovery pipe 330 for supplying the electrolyte from the cathode gas-liquid separator 200 and the anode gas-liquid separator 300 to the electrolyte correction unit 400 may each be formed as a single pipe, or the cathode electrolyte recovery pipe 230 and the anode electrolyte recovery pipe 330 may each be formed as a plurality of pipes corresponding to the n+1 electrolyte storage units.

[0145] The electrolyte compensation unit may have a manifold inside for smooth supply and discharge of the electrolyte.

[0146] Furthermore, since the cation exchange membrane 510 has gas barrier properties, it is possible to prevent the mixing of oxygen gas and hydrogen gas, and to prevent the risk of explosion due to the concentration of hydrogen gas in oxygen gas and the concentration of oxygen gas in hydrogen gas exceeding the explosive range.

[0147] 1st to 8th embodiments Referring to FIG. 8, the electrolyte correcting unit 400 of the first to eighth embodiment has the same structure as that of the first to seventh embodiment, except that electrodes are provided at both ends of the electrolyte correcting unit 400.

[0148] The electrolyte correcting unit 400 is provided at both ends with a positive electrode 460 and a negative electrode 470. When a potential difference is generated by applying a power source to the positive electrode 460 and the negative electrode 470, ions in the electrolyte inside the electrolyte correcting unit 400 move through the cation exchange membrane 510 and the anion exchange membrane 520.

[0149] In this case, a cation exchange membrane 510 is located on the side of the positive electrode chamber electrolyte receiving portion 410 adjacent to the positive electrode, and an anion exchange membrane 520 is located on the side of the negative electrode chamber electrolyte receiving portion 420 adjacent to the positive electrode, and a cation exchange membrane 510 is located on the side of the negative electrode chamber electrolyte receiving portion 420 adjacent to the positive electrode.

[0150] As described above, when the difference in electromotive force is utilized using electrodes, the movement of ions becomes faster, so the time required for correcting the concentration of the electrolyte can be reduced.

[0151] 2-1 Embodiment Referring to FIG. 3, in one embodiment, the present invention includes an electrolytic cell 100 including a cathode chamber 130 and an anode chamber 150 separated by a partition wall 110, a cathode chamber electrolyte receiving portion 410 of an electrolyte correcting portion 400 communicating with the cathode chamber 130 through a second cathode recovery pipe 211, an anode chamber electrolyte receiving portion 420 of the electrolyte correcting portion 400 communicating with the anode chamber 150 through a second anode recovery pipe 311, and a separator 500 separating the cathode chamber electrolyte receiving portion 410 and the anode chamber electrolyte receiving portion 420 from each other within the electrolyte correcting portion 400. The storage section 420 is divided and includes a cathode side gas-liquid separator 200 and an anode side gas-liquid separator 300 which are in communication with the cathode chamber electrolyte storage section 410 and the anode chamber electrolyte storage section 420 via a second cathode electrolyte recovery pipe 231 and a second anode electrolyte recovery pipe 331, respectively. The cathode side gas-liquid separator 200 and the anode side gas-liquid separator 300 supply electrolyte to the cathode chamber and the anode chamber of the electrolytic cell 100 via a second cathode electrolyte supply pipe 441 and a second anode electrolyte supply pipe 451. At this time, the second cathode electrolyte supply pipe 441 and the second anode electrolyte supply pipe 451 may be provided with a circulation pump 600.

[0152] The electrolyte may be an aqueous solution of KOH.

[0153] In the electrolytic bath 100, the following reaction occurs when an electrolyte having a molar concentration of x is supplied from the electrolyte correcting unit 400.

[0154] Positive electrode: 2OH - →1 / 2O2+H2O+2e -

[0155] Negative electrode: 2H2O+2e - →H2+2OH -

[0156] That is, in the positive electrode chamber, hydroxide thing ions (OH - ) is consumed, oxygen gas is generated, and hydroxide thing ions (OH - ) is produced, and hydrogen gas is generated. As a result, the molar concentration of the electrolyte discharged from the positive electrode chamber becomes (xa) moles, and oxygen gas is dissolved therein. Also, the molar concentration of the electrolyte discharged from the negative electrode chamber becomes (x + a) moles, and hydrogen gas is dissolved therein.

[0157] The electrolyte discharged from the positive electrode chamber 130 and the negative electrode chamber 150 moves to the positive electrode chamber electrolyte receiving section 410 and the negative electrode chamber electrolyte receiving section 420 of the electrolyte correcting section 400 through the second positive electrode recovery pipe 211 and the second negative electrode recovery pipe 311 .

[0158] The electrolyte solution flowing into the electrolyte correction unit 400 through the second positive electrode recovery pipe 211 and the second negative electrode recovery pipe 311 contains dissolved oxygen gas and hydrogen gas, respectively. In the water electrolysis device according to the present embodiment, the oxygen gas and hydrogen gas discharged from the electrolytic cell and the electrolyte solution have not yet passed through the positive electrode-side gas-liquid separator 200 and the negative electrode-side gas-liquid separator 300, so the dissolved oxygen gas and hydrogen gas have higher concentrations than in the first embodiment.

[0159] Referring to FIG. 4, in the electrolyte correcting unit 400, the (xa) moles of electrolyte flowing in through the second cathode recovery pipe 211 and the (x+a) moles of electrolyte flowing in through the second anode recovery pipe 311 are supplied to the cathode chamber electrolyte receiving unit 410 and the anode chamber electrolyte receiving unit 420, respectively, by the diaphragm 500.

[0160] The diaphragm 500 is an ion-permeable diaphragm that allows ions to pass through and separates hydrogen gas and oxygen gas produced in the electrolytic cell.

[0161] The diaphragm has a plurality of fine through-pores and has a structure that allows the electrolyte to pass through, but has gas barrier properties that prevent the hydrogen gas and oxygen gas dissolved in the electrolyte from passing through.

[0162] Therefore, since the (x+a) moles of electrolyte in anode chamber electrolyte accommodating section 420 flowing in through second anode recovery pipe 311 has a higher concentration than the (xa) moles of electrolyte in cathode chamber electrolyte accommodating section 410 flowing in through second cathode recovery pipe 211, ions in the electrolyte in anode chamber electrolyte accommodating section 420 move through the diaphragm to the electrolyte in cathode chamber electrolyte accommodating section 410, and as a result, the concentration gradient of the electrolyte in the electrolyte correction section separated by the diaphragm disappears.

[0163] In addition, the electrolyte correcting unit 400 prevents the mixing of oxygen gas and hydrogen gas by the diaphragm 500, thereby preventing the risk of explosion caused by the hydrogen gas concentration exceeding the explosive range in the oxygen gas.

[0164] In the cathode gas-liquid separator 200, oxygen gas dissolved in the electrolyte exists as a gas phase region, and the electrolyte exists as a liquid phase region, and the gas phase region may be provided with an oxygen gas discharge pipe 220 for discharging the oxygen gas to the outside of the system. In addition, the electrolyte existing in the liquid phase region flows into the cathode chamber 130 of the electrolytic cell 100 through a second cathode electrolyte supply pipe 441.

[0165] In the anode gas-liquid separator 300, the hydrogen gas dissolved in the electrolyte exists as a gas phase region, and the electrolyte exists as a liquid phase region, and the gas phase region may be provided with a hydrogen gas discharge pipe 320 for discharging the hydrogen gas to the outside of the system. In addition, the electrolyte existing in the liquid phase region flows into the anode chamber 150 of the electrolytic cell 100 through a second anode electrolyte supply pipe 451.

[0166] 2-2 embodiment The second embodiment is configured in the same manner as the first embodiment, except that the electrolyte correcting unit 400 includes a plurality of porous membranes.

[0167] The electrolyte compensation unit 400 has n+1 electrolyte storage compartments formed by n porous diaphragms, and (xa) moles of electrolyte flowing from the positive electrode chamber 130 and (x+a) moles of electrolyte flowing from the negative electrode chamber 150 alternately flow into the n+1 electrolyte storage compartments.

[0168] In this case, the second cathode electrolyte recovery pipe 231 and the second anode electrolyte recovery pipe 331 for supplying the electrolyte from the electrolyte correction unit 400 to the cathode gas-liquid separator 200 and the anode gas-liquid separator 300 may each be formed as a single pipe and may have a manifold therein for smooth supply to the electrolyte receiving units. Also, a plurality of pipes may be formed corresponding to the n+1 electrolyte receiving units.

[0169] Second and third embodiments The second embodiment is configured in the same manner as the first embodiment, except that the electrolyte compensation unit 400 uses a cation exchange membrane 510 instead of a porous membrane.

[0170] The cation exchange membrane 510 selectively allows only cations in the electrolyte to pass through, and has gas barrier properties.

[0171] At this time, inside the electrolyte correction unit 400, the cations of the (x+a) moles of the electrolyte in the anode chamber electrolyte storage unit 420 that flowed in from the anode chamber 150 (i.e., K + ions) move through the cation exchange membrane due to a concentration gradient to the (xa) moles of electrolyte in the cathode chamber electrolyte storage section 410 that has flowed in from the adjacent cathode chamber 130. Thereafter, to maintain ion balance, anions can pass through the membrane and move, even though the cation exchange membrane has cation selectivity. That is, the anions (i.e., OH - ions) move through the cation exchange membrane to the (xa) moles of electrolyte in the adjacent positive electrode chamber electrolyte storage section 410. As a result, the concentration of the electrolyte finally discharged from the electrolyte correction section 400 becomes x moles.

[0172] 2nd-4th embodiment The second embodiment is configured in the same manner as the second embodiment, except that a plurality of cation exchange membranes 510 are provided in the electrolyte correcting unit 400.

[0173] Referring to FIG. 5, the cation exchange membrane selectively allows only cations in the electrolyte to pass through and has gas barrier properties.

[0174] The electrolyte correction unit 400 has n+1 electrolyte storage compartments formed by n cation exchange membranes, and (xa) moles of electrolyte flowing in from the positive electrode chamber 130 and (x+a) moles of electrolyte flowing in from the negative electrode chamber 150 alternately flow into the n+1 electrolyte storage compartments.

[0175] At this time, inside the electrolyte correction unit 400, the cations of the (x+a) moles of the electrolyte in the anode chamber electrolyte storage unit 420 that flowed in from the anode chamber 150 (i.e., K + ions) move through the cation exchange membrane due to a concentration gradient to the (xa) moles of electrolyte in the cathode chamber electrolyte storage section 410 that has flowed in from the adjacent cathode chamber 130. Thereafter, to maintain ion balance, anions can pass through the membrane and move, even though the cation exchange membrane has cation selectivity. That is, the anions (i.e., OH - ions) move through the ion exchange membrane to the (xa) moles of electrolyte in the adjacent positive electrode chamber electrolyte storage section 410. As a result, the concentration of the electrolyte finally discharged from the electrolyte correction section 400 becomes x moles.

[0176] In this case, the second cathode electrolyte recovery pipe 231 and the second anode electrolyte recovery pipe 331 for supplying the electrolyte from the electrolyte correction unit 400 to the cathode side gas-liquid separator 200 and the anode side gas-liquid separator 300 may each be formed as a single pipe, or the second cathode electrolyte recovery pipe 231 and the second anode electrolyte recovery pipe 331 may each be formed as a plurality of pipes corresponding to the n+1 electrolyte receiving units.

[0177] In addition, the cathode side gas-liquid separator 200 for supplying the electrolyte from the electrolytic cell 100 to the electrolyte solution correction unit 400 and the second cathode return pipe 211 for supplying the electrolyte to the anode side gas-liquid separator 300 may each be formed as a single pipe, or the second cathode return pipe 211 and the second anode return pipe 311 may each be formed as a plurality of pipes corresponding to the n+1 electrolyte storage units.

[0178] The electrolyte compensation unit may have a manifold inside for smooth supply and discharge of the electrolyte.

[0179] Furthermore, since the cation exchange membrane 510 has gas barrier properties, it is possible to prevent the mixing of oxygen gas and hydrogen gas, and to prevent the risk of explosion due to the concentration of hydrogen gas in oxygen gas and the concentration of oxygen gas in hydrogen gas exceeding the explosive range.

[0180] 2-5th embodiment The second embodiment is configured in the same manner as the first embodiment, except that the electrolyte compensation unit 400 uses an anion exchange membrane 520 instead of a porous membrane.

[0181] The anion exchange membrane 520 selectively allows only anions in the electrolyte to pass through, and has gas barrier properties.

[0182] At this time, inside the electrolyte correction unit 400, the anions (i.e., OH) of the (x+a) moles of electrolyte in the anode chamber electrolyte storage unit 420 that flowed in from the anode chamber 150 - ions) move through the anion exchange membrane due to a concentration gradient to the (x+a) moles of electrolyte in the cathode chamber electrolyte storage section 410 that has flowed in from the adjacent cathode chamber 130. Thereafter, to maintain ion balance, cations can pass through the membrane and move, even though the anion exchange membrane has anion selectivity. That is, the cations (i.e., K +ions) migrate through the anion exchange membrane to the (xa) moles of electrolyte in the positive electrode chamber electrolyte storage section 410 that has flowed in from the adjacent positive electrode chamber 130. As a result, the concentration of the electrolyte finally discharged from the electrolyte correction section 400 becomes x moles.

[0183] 2nd to 6th embodiments The second embodiment is configured in the same manner as the second embodiment, except that a plurality of anion exchange membranes 520 are provided in the electrolyte correcting unit 400.

[0184] Referring to FIG. 6, the anion exchange membrane 520 selectively allows only anions in the electrolyte to pass through, and has gas barrier properties.

[0185] The electrolyte correction unit 400 has n+1 electrolyte storage compartments formed by n anion exchange membranes, and (xa) moles of electrolyte flowing in from the positive electrode chamber 130 and (x+a) moles of electrolyte flowing in from the negative electrode chamber 150 alternately flow into the n+1 electrolyte storage compartments.

[0186] At this time, inside the electrolyte correction unit 400, the anions (i.e., OH) of the (x+a) moles of electrolyte in the anode chamber electrolyte storage unit 420 that flowed in from the anode chamber 150 - ions) move through the anion exchange membrane due to a concentration gradient to the (x+a) moles of electrolyte in the cathode chamber electrolyte storage section 410 that has flowed in from the adjacent cathode chamber 130. Thereafter, to maintain ion balance, cations can pass through the membrane and move, even though the anion exchange membrane has anion selectivity. That is, the cations (i.e., K + ions) move through the ion exchange membrane to the (xa) moles of electrolyte in the positive electrode chamber electrolyte storage section 410 that has flowed in from the adjacent positive electrode chamber 130. As a result, the concentration of the electrolyte finally discharged from the electrolyte correction section 400 becomes x moles.

[0187] In this case, the second cathode electrolyte recovery pipe 231 and the second anode electrolyte recovery pipe 331 for supplying the electrolyte from the electrolyte correction unit 400 to the cathode side gas-liquid separator 200 and the anode side gas-liquid separator 300 may each be formed as a single pipe, or the second cathode electrolyte recovery pipe 231 and the second anode electrolyte recovery pipe 331 may each be formed as a plurality of pipes corresponding to the n+1 electrolyte receiving units.

[0188] In addition, the cathode side gas-liquid separator 200 for supplying the electrolyte from the electrolytic cell 100 to the electrolyte solution correction unit 400 and the second cathode return pipe 211 for supplying the electrolyte to the anode side gas-liquid separator 300 may each be formed as a single pipe, or the second cathode return pipe 211 and the second anode return pipe 311 may each be formed as a plurality of pipes corresponding to the n+1 electrolyte storage units.

[0189] The electrolyte compensation unit may have a manifold inside for smooth supply and discharge of the electrolyte.

[0190] Furthermore, since the anion exchange membrane 520 has gas barrier properties, it is possible to prevent the mixing of oxygen gas and hydrogen gas, and to prevent the risk of explosion caused by the concentration of hydrogen gas in oxygen gas and the concentration of oxygen gas in hydrogen gas exceeding the explosive range.

[0191] 2-7th embodiment 7, in the second to seventh embodiments, a plurality of cation exchange membranes 510 and a plurality of anion exchange membranes 520 are alternately provided in the electrolyte correction unit 400. In this case, the cation exchange membranes selectively allow only cations in the electrolyte to pass through, and the anion exchange membranes selectively allow only anions in the electrolyte to pass through.

[0192] The electrolyte correction unit 400 has n+1 electrolyte storage compartments formed by n cation exchange membranes 510 and n anion exchange membranes 520, and (xa) moles of electrolyte flowing in from the positive electrode chamber 130 and (x+a) moles of electrolyte flowing in from the negative electrode chamber 150 alternately flow into the n+1 electrolyte storage compartments.

[0193] At this time, inside the electrolyte correction unit 400, the anions (i.e., OH) of the (x+a) moles of electrolyte in the anode chamber electrolyte storage unit 420 that flowed in from the anode chamber 150 - ions) move through the anion exchange membrane 520 due to a concentration gradient to the (xa) moles of electrolyte in the cathode chamber electrolyte storage section 410 that has flowed in from the adjacent cathode chamber 130. Also, the cations (i.e., K + ions) move through the cation exchange membrane 510 to the (xa) moles of electrolyte in the positive electrode chamber electrolyte storage section 410 that has flowed in from the adjacent positive electrode chamber 130. As a result, the concentration of the electrolyte finally discharged from the electrolyte correction section 400 becomes x moles.

[0194] In this case, the second cathode electrolyte recovery pipe 231 and the second anode electrolyte recovery pipe 331 for supplying the electrolyte from the electrolyte correction unit 400 to the cathode side gas-liquid separator 200 and the anode side gas-liquid separator 300 may each be formed as a single pipe, or the second cathode electrolyte recovery pipe 231 and the second anode electrolyte recovery pipe 331 may each be formed as a plurality of pipes corresponding to the n+1 electrolyte receiving units.

[0195] In addition, the cathode side gas-liquid separator 200 for supplying the electrolyte from the electrolytic cell 100 to the electrolyte solution correction unit 400 and the second cathode return pipe 211 for supplying the electrolyte to the anode side gas-liquid separator 300 may each be formed as a single pipe, or the second cathode return pipe 211 and the second anode return pipe 311 may each be formed as a plurality of pipes corresponding to the n+1 electrolyte storage units.

[0196] The electrolyte compensation unit may have a manifold inside for smooth supply and discharge of the electrolyte.

[0197] Furthermore, since the anion exchange membrane 520 has gas barrier properties, it is possible to prevent the mixing of oxygen gas and hydrogen gas, and to prevent the risk of explosion caused by the concentration of hydrogen gas in oxygen gas and the concentration of oxygen gas in hydrogen gas exceeding the explosive range.

[0198] 2-8th embodiment Referring to FIG. 8, the second embodiment is configured in the same manner as the second embodiment, except that the electrolyte correcting unit 400 has electrodes at both ends thereof.

[0199] The electrolyte correcting unit 400 is provided at both ends with a positive electrode 460 and a negative electrode 470. When a potential difference is generated by applying a power source to the positive electrode 460 and the negative electrode 470, ions in the electrolyte inside the electrolyte correcting unit 400 move through the cation exchange membrane 510 and the anion exchange membrane 520.

[0200] In this case, a cation exchange membrane 510 is located on the side of the positive electrode chamber electrolyte receiving portion adjacent to the positive electrode 460, and an anion exchange membrane 520 is located on the side of the negative electrode chamber electrolyte receiving portion adjacent to the positive electrode 470, and an anion exchange membrane 520 is located on the side of the negative electrode chamber electrolyte receiving portion adjacent to the positive electrode, and a cation exchange membrane 510 is located on the side of the negative electrode chamber electrolyte receiving portion adjacent to the negative electrode.

[0201] As described above, when the difference in electromotive force is utilized using electrodes, the movement of ions becomes faster, so the time required for correcting the concentration of the electrolyte can be reduced. [Industrial Applicability]

[0202] The present invention provides an electrolyte correcting unit including a diaphragm for eliminating a concentration difference between electrolytes, thereby preventing the gas composition in the gas phase region of the water electrolysis device from reaching an explosion limit. Furthermore, even when the electrolytes discharged from the cathode chamber and the anode chamber are circulated independently, no difference in electrolyte concentration occurs. This eliminates the need for an additional device for eliminating this difference, and solves problems of reduced processability due to reinjection of electrolyte and operational stabilization.

Claims

1. an electrolytic cell including a positive electrode chamber and a negative electrode chamber separated by a partition; an electrolyte correction section including a positive electrode chamber electrolyte storage section and an anode chamber electrolyte storage section, the positive electrode chamber electrolyte storage section and the anode chamber electrolyte storage section being separated by a diaphragm; a positive electrode circulation line communicating the positive electrode chamber of the electrolytic cell with the positive electrode chamber electrolyte storage unit of the electrolyte correction unit; and a negative electrode circulation line communicating the negative electrode chamber of the electrolytic cell with the negative electrode chamber electrolyte storage section of the electrolyte correction section, the membrane is permeable to electrolyte and ions; It is gas impermeable, the electrolyte correction unit is provided to reduce a difference in hydroxide ion concentration between the electrolyte discharged from the positive electrode chamber and the electrolyte discharged from the negative electrode chamber.

2. a positive electrode side gas-liquid separator provided in the positive electrode circulation line; and The water electrolysis apparatus according to claim 1 , further comprising an anode-side gas-liquid separator provided in the anode circulation line.

3. the positive electrode side gas-liquid separator is provided along the positive electrode circulation line between the rear end of the positive electrode chamber of the electrolytic cell and the front end of the positive electrode chamber electrolyte accommodating portion of the electrolyte correcting portion, 3. The water electrolysis apparatus according to claim 2, wherein the anode-side gas-liquid separator is provided along the anode circulation line between a rear end of the anode chamber of the electrolytic cell and a front end of the anode chamber electrolyte accommodating section of the electrolyte correcting section.

4. the positive electrode side gas-liquid separator is provided along the positive electrode circulation line between the rear end of the positive electrode chamber electrolyte accommodating portion of the electrolyte correcting portion and the front end of the positive electrode chamber of the electrolytic cell; 3. The water electrolysis apparatus according to claim 2, wherein the anode-side gas-liquid separator is provided along the anode circulation line between a rear end of the anode chamber electrolyte accommodating portion of the electrolyte correcting portion and a front end of the anode chamber of the electrolytic cell.

5. The water electrolysis apparatus according to claim 1 , wherein the diaphragm is a porous membrane.

6. The water electrolysis apparatus according to claim 1 , wherein the diaphragm is a cation exchange membrane or an anion exchange membrane.

7. The water electrolysis apparatus according to claim 1 , wherein a plurality of the diaphragms are provided, and the positive electrode chamber electrolyte accommodating sections and the negative electrode chamber electrolyte accommodating sections are arranged alternately.

8. 8. The water electrolysis apparatus according to claim 7, wherein when the positive electrode chamber electrolyte storage portions and the negative electrode chamber electrolyte storage portions are alternately arranged, the plurality of diaphragms alternately arranged in a direction in which the storage portions are alternately arranged are provided with cation exchange membranes and anion exchange membranes alternately.

9. 8. The water electrolysis apparatus according to claim 7, wherein a positive electrode and a negative electrode are provided at both ends of the electrolyte correction section, and a diaphragm is positioned between the positive electrode and the negative electrode.

10. the diaphragm is a cation exchange membrane or an anion exchange membrane, A cation exchange membrane is disposed on the side of the positive electrode chamber electrolyte storage portion adjacent to the positive electrode, and an anion exchange membrane is disposed on the side of the positive electrode chamber electrolyte storage portion adjacent to the negative electrode.

10. The water electrolysis apparatus according to claim 9, wherein an anion exchange membrane is located on a side of the negative electrode chamber electrolyte housing portion adjacent to the positive electrode, and a cation exchange membrane is located on a side of the negative electrode chamber electrolyte housing portion adjacent to the negative electrode.

11. 2. The water electrolysis apparatus according to claim 1, further comprising a water supply pipe and a water supply pump for supplying water to at least one of the anode chamber of the electrolytic cell, the anode chamber electrolyte storage unit of the electrolyte correction unit, and the anode circulation line.

12. 3. The water electrolysis apparatus of claim 2, further comprising a water supply pipe and a water supply pump for supplying water to at least one of the anode chamber of the electrolytic cell, the anode chamber electrolyte storage unit of the electrolyte correction unit, the anode-side gas-liquid separator, and the anode circulation line.

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