WO2022181875A1 - Water management apparatus in hydrogen production system using water electrolysis - Google Patents

Abstract

The present invention relates to a water management apparatus, which is disposed on a water circulation line of a hydrogen production system using water electrolysis to remove impurities generated during water electrolysis and circulation procedures, the apparatus comprising a first reaction tower (500) removing radicals generated during the water electrolysis procedure and a second reaction tower (600) removing metal ions generated during the water circulation procedure, wherein the first reaction tower (500) comprises a filling (510) composed of a radical scavenger catalyst (512) on a carrier (511).

Description

Water management device in hydrogen production system using water electrolysis

The present invention relates to a hydrogen production system using water electrolysis (hereinafter, water electrolysis), and more particularly, is disposed in the water circulation line of the hydrogen production system to secure the durability of the water electrolysis stack (electrochemical reactor). It relates to a device that manages water by removing radicals and metal ions, which are impurities generated in the electrolysis process and circulation process.

In general, there are various methods of producing hydrogen, but the method of obtaining hydrogen by electrolysis of water using a power source and water using renewable energy does not generate CO ₂ during the hydrogen production process, so CO ₂ free hydrogen, or green Hydrogen has recently been in the spotlight under another name.

1 to 3 show the basic principle of a typical electrochemical cell (electrochemical reactor) for obtaining hydrogen by electrolysis of water, a unit electrochemical cell, and a stack structure for electrochemistry.

1 is a conceptual diagram of a membrane electrode assembly 100 constituting a part of a typical electrochemical cell that produces hydrogen gas and oxygen gas by electrochemically decomposing water. The membrane electrode assembly 100 is the core of the electrochemical reaction. is a component

The electrochemical cell for electrolysis that electrolyzes water (H ₂ 0) to produce oxygen gas (O ₂ ) and hydrogen gas (H ₂ ) is a first electrochemical reaction layer 104, a second electrochemical reaction layer ( 108 ), a film 106 , a first diffusion layer 102 , and a second diffusion layer 110 . At this time, the first electrochemical reaction layer 104 is composed of the first electrochemical catalyst 112 and the first carrier 114, the second electrochemical reaction layer 108 is the second electrochemical catalyst 116 and and a second carrier 118 .

The first diffusion layer 102 and the second diffusion layer 110 assist in transport of electrons and reactants or products to (or to) the first and second electrochemical catalysts 112 and 116 . The first and second electrochemical catalysts 112 and 116 are the most important materials for electrolysis or for making electrical energy, and the first and second carriers 114 and 118 are the first and second electrochemical catalysts 112 and 118. 116) serves as a support and provides a path for electrons to move.

The first and second electrochemical catalysts 112 and 116 are mixed with the first and second carriers 114 and 118, a binder and a solvent to form a slurry or paste. After being made, the first and second electrochemical reaction layers 104 and 108 are formed by coating on the film 106 or on the first and second diffusion layers 102 and 110 . At this time, the "electrochemical reaction layer 104, 108-membrane 106" or "electrochemical reaction layer 104, 108-membrane 106- diffusion layer 102, 110" made in this way is applied to the membrane electrode assembly ( 100) (Membrane Electrode Assembly, hereinafter referred to as "MEA").

The gap between the first electrochemical reaction layer 104 and the second electrochemical reaction layer 108 formed in the MEA 100 has a thickness value of a physical film, and the first electrochemical reaction layer 104 and the second electrochemical reaction layer 104 Since bubbles do not exist in the reaction layer 108 , it is possible to operate at a low voltage and a high current. In addition, since the conductivity of the electrolyte is not used as in the alkaline electrochemical cell, water as a raw material can be used with high purity, and there is an advantage in that high purity hydrogen and oxygen can be obtained.

A process of electrolyzing water using the configuration shown in FIG. 1 will be described as follows. Here, the place where the oxidation reaction occurs is the first electrochemical reaction layer 104 , and the place where the reduction reaction occurs is the second electrochemical reaction layer 108 , and the oxidation reaction and the reduction reaction occur simultaneously.

First, when water (H ₂ 0) is supplied to the first electrochemical reaction layer 104 through the first diffusion layer 102, water is generated by the first electrochemical catalyst 112 (oxidation catalyst, positive electrode active material, oxygen gas) At the pole), a decomposition reaction takes place into oxygen gas (O ₂ ), electrons (e ^- ), and hydrogen ions (H ⁺ ) (protons) as shown in Reaction Equation 1 below. At this time, oxygen gas (O ₂ ) flows out of the electrochemical cell (electrolysis cell) by diffusion, and hydrogen ions (H ⁺ ) pass through the membrane 106 by an electric field and the second electrochemical catalyst 116 ) (reduction catalyst, negative electrode active material, also referred to as a hydrogen gas generating electrode), and the electrons (e ^- ) generated by the reaction are transferred from the first electrochemical catalyst 112 to the first diffusion layer 102, an external circuit (not shown). city) through the second diffusion layer 110 and the second electrochemical catalyst 116 .

On the other hand, in the second electrochemical catalyst 116, hydrogen ions (H ⁺ ) and electrons (e ^- ) moved from the first electrochemical catalyst 112 react to generate hydrogen gas (H ₂ ) as shown in Scheme 2 . And, some of the water supplied to the first electrochemical reaction layer 104 moves to the second electrochemical reaction layer 108 by the electric field and flows out together with the hydrogen gas (H ₂ ) to the outside of the electrolysis cell.

When the electrochemical reaction that occurred in the first electrochemical catalyst 112 and the second electrochemical catalyst 116, respectively, is expressed, the following Reaction Schemes 1 and 2 are the same, and the overall reaction (general reaction) in the electrochemical cell is Scheme 3 same as

[Scheme 1]

2H ₂ O → 4H ⁺ + 4e ^- + O ₂ (anode)

[Scheme 2]

4H ⁺ + 4e ^- → 2H ₂ (cathode)

[Scheme 3]

2H ₂ O → O ₂ (anode) + 2H ₂ (cathode)

FIG. 2 is a structural diagram of a typical electrochemical cell for electrolyzing water with the MEA of FIG. 1 . 2, the electrochemical cell 200 is a first end plate 202 (End Plate), a first insulating plate 204, a first current supply plate 206, a first electrochemical reaction chamber frame 208, the first electrochemical reaction chamber 210, the MEA (100 in FIG. 1), the second electrochemical reaction chamber 212, the second electrochemical reaction chamber frame 214, the second current supply plate 216 ), a second insulating plate 218 and a second end plate 220, and there is a DC power supply as a power converter 224 for supplying current to the electrochemical cell.

The first end plate 202 and the second end plate 220 provide bolt/nut fastening holes (not shown) for assembling a unit electrochemical cell, and passages of reactants and products (not shown), and the first insulating plate 204 and the second insulating plate 218 are electrically connected between the first end plate 202 and the first current supply plate 206 and between the second end plate 220 and the second current supply plate 216, respectively. Insulating function, the first current supply plate 206 and the second current supply plate 216 are connected to the power conversion device 224 serves to supply the required current to the electrochemical cell (200).

On the other hand, when the first electrochemical reaction layer 104 is located in the first electrochemical reaction chamber 210 and the oxidation reaction occurs, it becomes a space for movement of water as a reactant and oxygen as a product, and the film 106 is formed In the second electrochemical reaction chamber 212 located on the opposite side of the first electrochemical reaction chamber 210 to the center, for the movement of hydrogen generated by the reduction reaction and the water moved in the first electrochemical reaction chamber 210 . space is provided.

The first electrochemical reaction chamber 210 is blocked from the outside by the first electrochemical reaction chamber frame 208 , and the second electrochemical reaction chamber 212 is externally by the second electrochemical reaction chamber frame 214 . and is blocked In addition, gaskets (or packings) 222 for preventing external leakage of reactants and products are installed between the MEA 100 and the first electrochemical reaction chamber frame 208 and the second electrochemical reaction chamber frame 214 , respectively. .

Among the components constituting the electrochemical cell 200 , the first electrochemical reaction chamber frame 208 , the second electrochemical reaction chamber frame 214 , and the gasket 222 include the inflow of reactants or products through the electrochemical cell and It has an appropriate hole for easy outflow, and the first electrochemical reaction chamber frame 208 and the second electrochemical reaction chamber frame 214 have a fluid (oxygen, hydrogen, water) flow path (a dotted line in FIG. 2A). indicated by ) is formed.

3 is a conceptual diagram of a conventional general electrochemical stack. In order to obtain a desired amount of product in the electrolysis reaction, a plurality of unit electrochemical cells are required. In this case, an aggregate of two or more stacked electrochemical cells is called an electrochemical stack.

As shown in FIG. 3 , when the electrochemical cells are stacked to form the electrochemical stack 300 , a desired number of unit electrochemical cells are repeatedly installed between the basic electrochemical cells 200 . In the electrochemical stack, the unit electrochemical cells are assembled by coupling the bolt 306 and the nut 310 through holes formed at the edges of the first and second end plates 202 and 220 .

A bipolar plate 304 in which the first electrochemical reaction chamber frame 208 and the second electrochemical reaction chamber frame 214 of FIG. 2 are integrated is applied to the electrochemical stack 300 . The bipolar plate 304 is an integral plate and has the functions of an anode chamber and a cathode chamber.

4 is a view illustrating a system for producing hydrogen by electrolyzing water using an electrolysis stack having the same concept as the electrochemical stack of FIG. 3 . The hydrogen production system 400 shown in FIG. 4 purifies the hydrogen gas generated from the electrolysis stack 420 , a water treatment unit for processing water supplied to the electrolysis stack 420 , and the electrolysis stack 420 , and It consists of a gas processing unit that controls the pressure.

Water, which is a raw material used in the electrolysis stack 420, uses 1 Mega ohm cm or more of pure water, and the pure water is supplied by the control of the automatic valve 402 installed in the pure water supply line s1, and the automatic valve 402 control is It is controlled by the level sensor 405 for detecting the water level in the oxygen-water separation tank 404 (dashed line e2). Water in the oxygen-water separation tank 404 is supplied to the electrolysis stack 420 by the circulation pump 406 installed in the circulation pipe s2, and a circulation line s9 circulated in the hydrogen-water separator 424. combined with the heat exchanger 408, the water quality detection sensor 410, and the ion exchange filter 412 through the installed pipe to the first electrochemical reaction chamber 414 of the electrolysis stack 420 (where the oxidation reaction takes place) is supplied On the other hand, when a DC current is supplied to the electrolysis stack 420 through the wire e1 from the power conversion device 440, a water decomposition reaction occurs.

Oxygen and unreacted water generated in the first electrochemical reaction chamber 414 are moved to the oxygen-water separation tank 404 through the discharge pipe s4, and a temperature sensor 416 for monitoring the temperature in the discharge pipe s4 ) is installed. Oxygen separated in the oxygen-water separation tank 404 is discharged to the outside through the oxygen discharge pipe s5, and the water undergoes a recirculation process.

The hydrogen gas generated in the second electrochemical reaction chamber 422 is accompanied by water, and is moved to the hydrogen-water separation tank 424 through the discharge pipe s6 to separate the gas and water. The hydrogen-water separation tank 424 is provided with a level sensor 426 for water level detection for water level control. If, when the water level in the hydrogen-water separation tank 424 exceeds a predetermined value, the automatic valve 428 is opened (electrical signal e3) and is supplied to the circulation pipe s2 through the circulation line s9.

Meanwhile, the hydrogen gas separated in the hydrogen-water separation tank 424 is supplied to the hydrogen gas purifier 430 through the gas pipe s7 to remove moisture contained in the hydrogen. In general, a bed filled with a desiccant is applied to the hydrogen gas purifier 430 . Hydrogen that has passed through the hydrogen gas purifier 430 is supplied to a site requiring hydrogen through a high-purity hydrogen gas pipe s8. At this time, there is a pressure regulating valve 434 for controlling the pressure of hydrogen in the high-purity hydrogen gas pipe s8 so that the pressure of hydrogen gas generated in the electrolysis stack 420 is adjusted. Pressure sensors 432 and 438 for measuring pressure are installed at the front and rear ends of the pressure control valve 434 , and a check valve 436 for maintaining the flow of gas in a certain direction is installed.

As described above, securing long-term durability of the electrolysis stack 420, which is a key process in the process of producing hydrogen by electrolysis of water, is an important factor in lowering the hydrogen production price and system price.

[Prior art literature]

[Non-patent literature]

Ka Hung Wong and Erik Kjeang, "The Electrochemical Society Macroscopic In-Situ Modeling of Chemical Membrane Degradation in Polymer Electrolyte Fuel Cells", Journal of The Electrochemical Society, 161 (9) F823-F832 (2014) Journal of Power Sources, Vol. 420, 54-62, 2019

Frensch SH, Serre G, Fouda-Onana F, Jensen HC, Christensen ML, Araya SS, Kaer SK DOI, "Impact of iron and hydrogen peroxide on membrane degradation for polymer electrolyte membrane water electrolysis: Computational and experimental investigation on fluoride emission", Journal of Power Sources, Vol.420, 54-62, 2019

Daejin Yoon, Yeonseon Oh, Hyunseo Seo, Sangbong Moon, and Hoon Jeong, "Manufacturing and Performance Study according to Ceria Content of Covalently Crosslinked SPEEK/Cs-TSiA Membrane for Water Electrolysis", Trans. of the Korean Hydrogen and New Energy Society (2015. 6), Vol. 26, No. 3, pp. 212~220

Zhiyan Rui, JianguoLiu, "Review Understanding of free radical scavengers used in highly durable proton exchange membranes", Progress in Natural Science: Materials International, Vol. 30, 2020, pp.732-742

This invention is arranged in the water circulation line of the hydrogen production system using water electrolysis to secure the durability of the water electrolysis stack (electrochemical reactor) to remove radicals and metal ions, which are impurities generated during the electrolysis and circulation of water. An object of the present invention is to provide a device for managing water.

This invention for achieving the above object is a device for managing water by being disposed in a water circulation line of a hydrogen production system using water electrolysis and removing impurities generated in the electrolysis process and circulation process of water, and the electrolysis process of water A first reaction column for removing radicals generated in It is characterized in that it contains a filling.

Also, according to the present invention, the first reaction tower and the second reaction tower may be connected in series or in parallel.

In addition, according to the present invention, the metal ion is preferably Fe ²⁺ or Cu ²⁺ ion.

In addition, according to the present invention, the carrier may be composed of any one of titanium oxide, carbon black, graphite, graphite, activated carbon, carbon fiber, carbon nanotube, fullerene, titanium carbide, silica gel, alumina or other inorganic porous material. have.

Further, according to the present invention, the radical scavenger catalyst is preferably CeO2, ZrO2 _, or a complex oxide thereof.

In addition, according to the present invention, the amount of the radical scavenger catalyst is more preferably in the range of 1 to 5% by weight based on the weight of the carrier.

In addition, according to the present invention, the second reaction tower may include a chelate resin.

This invention has the advantage of lowering the hydrogen production cost during hydrogen production by removing impurities affecting the durability during a long-term operation in the water electrolysis process to secure the durability of the device. That is, this invention is arranged in the water circulation line of the hydrogen production system to remove radicals and metal ions, which are impurities generated in the electrolysis process and circulation process of water, to secure the durability of the water electrolysis stack (electrochemical reactor). Manufacturing cost can be lowered.

1 is a conceptual diagram of an MEA, which is a part of a typical electrochemical cell that electrochemically decomposes water to produce hydrogen gas and oxygen gas.

FIG. 2 is a structural diagram of a typical electrochemical cell for electrolyzing water with the MEA of FIG. 1 .

3 is a conceptual diagram of a conventional general electrochemical stack.

FIG. 4 is a view showing a system for producing hydrogen by electrolyzing water using the electrochemical stack of FIG. 3 .

5 is a view showing a hydrogen production system using water electrolysis having a water management device according to an embodiment of the present invention.

6 is a conceptual view of the first reaction tower shown in FIG.

Fig. 7 is a structural diagram of the filling material shown in Fig. 6;

8 is a view showing a hydrogen production system using water electrolysis having a water management device according to another embodiment of the present invention.

9 is a graph showing the comparison of the performance of Inventive Examples 1 and 2 and Comparative Example 1 according to the present invention.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment in which a person of ordinary skill in the art to which this invention pertains can easily practice this invention will be described in detail. However, when it is determined that a detailed description of a related well-known function or configuration may unnecessarily obscure the gist of the present invention in describing the operating principle of the preferred embodiment of the present invention in detail, the detailed description thereof will be omitted. In addition, the same reference numerals are used for parts having similar functions and actions throughout the drawings.

5 is a view showing a hydrogen production system using water electrolysis having a water management device according to an embodiment of the present invention. As shown in FIG. 5, the water management device according to an embodiment of the present invention is disposed in the water circulation line of the hydrogen production system 400A configured in the same concept as in FIG. 4 to receive power in the electrolysis process and circulation process of water. This is to manage water by removing impurities that affect the durability of the stack (electrochemical reactor). Therefore, in this embodiment, the description of the hydrogen production system having the same concept as that of FIG. 4 is omitted and the same or similar reference numerals are used.

As shown in FIG. 5 , the water management device of this embodiment is configured to remove radicals generated in the electrolysis process of water and metal ions generated in the water cycle process. That is, the water management device of this embodiment includes the first reaction tower 500 for removing radicals generated in the water electrolysis stack (FIG. 3), and Fe ²⁺ or Cu generated in the hydrogen production system (FIG. 4). A second reaction tower 600 for removing ²⁺ ions is provided, and the first reaction tower 500 and the second reaction tower 600 are provided in series. Here, the second reaction tower (adsorption tower) 600 is generally a commercially available chelate resin applied for heavy metal removal is preferably applied.

In order to confirm the necessity of the development of the water management device according to the present invention, the OH radical generation process will be described as follows.

Oxygen gas (O ₂ ) and hydrogen ions (H ⁺ ) generated at the anode of the electrolysis cell generate hydrogen peroxide (H ₂ O ₂₎ (reaction formula 4), and the hydrogen peroxide is in the pipe (metal) of the hydrogen production system of FIG. It reacts with the eluted Fe ²⁺ or Cu ²⁺ to generate OH radicals that affect the durability of the membrane 106 (cation exchange membrane) of FIG. 1 (Scheme 5). The OH radical generation reaction is known as the Fenton reaction.

[Scheme 4]

O ₂ + 2H ⁺ + 2e ^- → H ₂ O ₂

[Scheme 5]

H ₂ O ₂ + Fe ²⁺ → Fe ³⁺ + HO ^· + HO ^-

It is known that the OH radical generated by Scheme 5 attacks the membrane 106 of the polymer component in the MEA of FIG. 1, which is a key component of the electrochemical cell, to weaken the durability.

6 and 7 are for removing OH radicals generated by Scheme 5. FIG. 6 is a conceptual diagram of the first reaction tower shown in FIG. 5, and FIG. 7 is a structural diagram of the packing shown in FIG.

As shown in FIG. 6 , the first reaction tower 500 is configured similarly to a generally used water purification tower, with a filler 510 and a filler 520 for preventing the outflow of the filler 510 . is composed On the other hand, the packing 510 is composed of a catalyst 512 for radical scavenger (scavenger) in the carrier 511 as shown in FIG. As the carrier 511, titanium oxide, carbon black, graphite, graphite, activated carbon, carbon fiber, carbon nanotube, fullerene, titanium carbide, silica gel, alumina or other inorganic porous material is used, and preferably with regular and fine pores. A titanium-based inorganic material having a structure is suitable. On the other hand, the carrier 610 preferably has a particle diameter of 0.02 mm or more.

The radical scavenger catalyst 512 applied on the carrier 511 is preferably CeO2, ZrO2 _, or a complex oxide thereof. The amount of the radical scavenger catalyst 512 applied on the carrier 511 is preferably in the range of 1 to 5% by weight based on the weight of the carrier 511 . The reason is that the radical removal rate becomes low at 1 wt% or less, and at 5 wt% or more, the radical removal amount is an inflection point at which the amount becomes constant.

The process of forming the radical scavenger catalyst 512 on the carrier 511 may be obtained by mixing the carrier and the precursor, adsorbing the precursor on the carrier, and then sintering. The reaction formula for this process is as follows.

[Scheme 6]

Ce(NO ₃ ) ₃ .6H ₂ O (CeCl ₃ or CeCl ₄ )→ CeO ₂ + NO _x

The thermal decomposition temperature for Scheme 6 is preferably 225 to 400 °C. The reason is that it is difficult to obtain CeO ₂ crystallinity at 225° C. or lower, and metal crystallinity is obtained at 400° C. or higher, resulting in lower catalytic activity.

8 is a view showing a hydrogen production system using water electrolysis having a water management device according to another embodiment of the present invention. As shown in FIG. 8 , the water management device according to this embodiment is installed in the hydrogen production system 400B configured in the same concept as in FIG. 4 , but with the first reaction tower 500 having the same configuration as above and The second reaction tower 600 is configured in parallel.

Hereinafter, the results according to the embodiment of the present invention will be described.

[Invention Example 1]

After the production and evaluation of the electrochemical cell for hydrogen production, it was applied to the hydrogen production system 400A shown in FIG. 5 .

(1) Manufacturing process of MEA (100)

It consists of a process of forming the first and second electrochemical reaction layers 104 and 108 , a process of forming on the film 106 , an ink manufacturing process, an ink transfer process, and a thermocompression bonding process.

(1-1) Synthesis process of the first and second electrochemical catalysts 112 and 116

As the first and second electrochemical catalysts 112 and 116, commercially available Pt/C (Premetek, 30% by weight of platinum) was used.

(1-2) Ink manufacturing process of the first and second electrochemical catalysts 112 and 116

Pt/C (Premetek, 30% platinum loading) as the electrochemical catalysts 112 and 116, and Nafion solution (registered product, DuPont) were used as the binder. The catalyst and Nafion solution used were mixed in an isopropyl alcohol solvent in a ratio of 1:7.5 based on the solid weight. In order to disperse the catalyst, stirring and ultrasonication were alternately treated twice for 1 hour each.

(1-3) Transfer process of the first and second electrochemical catalysts 112 and 116

(1-2) The ink obtained in the process was transferred to a dedicated syringe for electrospray, transferred to a carbon sheet, and dried at 90° C. for 30 minutes in an atmospheric atmosphere to prepare an electrochemical reaction layer. The thickness of the electrochemical reaction layer was adjusted so that the oxide catalyst loading amount was about 1 mg/cm 2 .

(1-4) Thermocompression bonding process

The electrochemical catalysts 112 and 116 prepared above were subjected to thermocompression treatment for 2 minutes at a pressure of 10 MPa under a condition of 120 ° C. .

(2) Composition of water electrolysis system

After manufacturing the MEA by the above procedure, a 1NM ³ H ₂ /hr electrochemical cell (or stack, 300) was manufactured, and a system 400 for producing hydrogen by electrolysis of water using the stack is configured as shown in FIG. 4 . did.

(3) Water purification process composition

(3-1) Preparation of the first reaction tower 500

As the carrier 511 used for the filler 510, titanium oxide (Degussa, P25) with excellent durability was applied. The purchased carrier was left in a weak acid (sulfuric acid, 1 Mole) and washed with pure water. As the radical scavenger catalyst 512 applied on the carrier, 5% by weight of a CeO ₂ and ZrO ₂ composite was applied. The molar ratio of CeO ₂ and ZrO ₂ formed on the carrier was set to 90:10.

Preparation was prepared by mixing a carrier (95 wt%) and CeO _{2 ,} ZrO ₂ precursor CeCl ₄ and ZrCl ₄ in a molar ratio, mixing them in IPA, and drying them at 80° C. overnight, then sintering them at 400° C. for 2 hours to obtain a filling. The obtained packing was filled in the reaction tower to prepare a first reaction tower.

(3-2) Preparation of the second reaction tower 600

Chelex 100 for removing Fe ²⁺ or Cu ²⁺ ions from Bio-rad was selected and applied.

(3-3) Construction of the process

5, the first reaction tower 500 and the second reaction tower 600 were operated in series.

(4) Evaluation method

The temperature of the electrochemical cell (or stack, 300) and system 400A was maintained at 50° C. (416 temperature sensor in FIG. 5), and the current density was accelerated to 3 A/cm ² (typical current density 1 A/cm ² ). The evaluation was performed and shown in FIG. 9 .

[Invention Example 2]

After the production and evaluation of the electrochemical cell for hydrogen production, it was applied to the hydrogen production system 400B shown in FIG. 8 .

(1) Manufacturing process of MEA (100): It was applied in the same manner as in Invention Example 1.

(2) Configuration of water electrolysis system: It was applied in the same manner as in Invention Example 1.

(3) Water purification process composition

(3-1) Preparation of the first reaction tower 500: It was applied in the same manner as in Inventive Example 1.

(3-2) Preparation of the second reaction tower 600: It was applied in the same manner as in Inventive Example 1.

(3-3) Process configuration: As shown in FIG. 8 , the first reaction tower 500 and the second reaction tower 600 were operated in parallel.

(4) Evaluation method

The temperature of the electrochemical cell (or stack, 300) and system 400B was maintained at 50° C. (416 temperature sensor in FIG. 8), and the current density was accelerated to 3 A/cm ² (typical current density of 1 A/cm ² ). It was evaluated and shown as Invention Example 2 in FIG. 9 .

[Comparative Example 1]

After the production and evaluation of the electrochemical cell for hydrogen production, it was applied to the hydrogen production system 400 shown in FIG. 4 .

(1) MEA (100) manufacturing process: It was applied in the same manner as in Inventive Example 1.

(2) Configuration of water electrolysis system: It was applied in the same manner as in Invention Example 1.

(3) Water purification process configuration: It was configured as a general process without the first reaction tower 500 and the second reaction tower 600 .

(4) Evaluation method

The temperature of the electrochemical cell (or stack, 300) and system 400 was maintained at 50° C. (416 temperature sensor in FIG. 4), and the current density accelerated to 3 A/cm ² (typical current density 1 A/cm ² ). It was evaluated and shown as Comparative Example 1 in FIG. 9 .

[result]

9 is a graph showing the comparison of the performance of Inventive Examples 1 and 2 and Comparative Example 1 according to the present invention, in which the durability of the water electrolytic stack is compared and evaluated through accelerated operation.

9, Inventive Example 1 (when the first and second reaction towers 500 and 600 are operated in series) and Inventive Example 2 (the first and second reaction towers 500 and 600 are operated in parallel) operation), it was confirmed that the durability is improved by 1.5 times or more than the durability (within 800 hours) of Comparative Example 1 (when the first and second reaction towers 500 and 600 are not present).

As can be seen through the above-described invention examples to which the accelerated test results are applied as described above, when the first and second reaction towers 500 and 600 are applied to the water treatment process, the durability of the stack in the water electrolysis system is improved, This makes it possible to lower the hydrogen production cost.

[Explanation of code]

100: MEA 200: electrochemical cell

300: electrochemical stack 400, 400A, 400B: hydrogen production system

500: first reaction tower 510: packing

511: carrier 512: radical scavenger catalyst

520: prevention material 600: second reaction tower

Claims (7)

1. A device that manages water by removing impurities generated during the electrolysis and circulation of water by being placed in the water circulation line of a hydrogen production system using water electrolysis,

   A first reaction tower for removing radicals generated in the electrolysis process of water;

   It includes a second reaction tower for removing metal ions generated in the water cycle process,

   The first reaction tower is a water management device in a hydrogen production system using water electrolysis, characterized in that it comprises a charge composed of a radical scavenger catalyst on a carrier.
2. The method according to claim 1,

   The first reaction tower and the second reaction tower are water management apparatus in a hydrogen production system using water electrolysis, characterized in that connected in series or parallel.
3. The method according to claim 1,

   The metal ion is a water management device in a hydrogen production system using water electrolysis, characterized in that Fe ²⁺ or Cu ²⁺ ion.
4. The method according to claim 1,

   The carrier is water electrolysis, characterized in that it is composed of any one of titanium oxide, carbon black, graphite, graphite, activated carbon, carbon fiber, carbon nanotube, fullerene, titanium carbide, silica gel, alumina or other inorganic porous material. Water management system in the hydrogen production system using.
5. 5. The method according to claim 4,

   The radical scavenger catalyst is CeO2, ZrO2 _, or a water management device in a hydrogen production system using water electrolysis, characterized in that a complex oxide thereof.
6. 6. The method of claim 5,

   The amount of the radical scavenger catalyst is a water management device in a hydrogen production system using water electrolysis, characterized in that in the range of 1 to 5% by weight relative to the weight of the carrier.
7. The method according to claim 1,

   The second reaction tower is a water management device in a hydrogen production system using water electrolysis, characterized in that it comprises a chelate resin (chelate resin).

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