Phase change mass transfer enhanced non-pure aqueous solution direct electrolysis hydrogen production system

Abstract

The utility model discloses a phase change mass transfer enhanced non-pure water solution direct electrolysis hydrogen production system, which belongs to the field of electrochemistry and comprises a non-pure water solution hydrogen production subsystem and a phase change mass transfer enhanced subsystem which are connected with each other. A non-pure water solution mass transfer device is arranged in a non-pure water solution heat preservation cabin of the phase change mass transfer enhancement subsystem, and a non-pure water solution inlet, a non-pure water solution outlet and a pure water vapor outlet are formed in the non-pure water solution heat preservation cabin; the non-pure water solution inlet is connected with a valve I, and the non-pure water solution outlet is connected with a valve II; the non-pure water solution mass transfer device comprises a non-pure water solution mass transfer unit, and a waterproof breathable layer is attached to the surface of the non-pure water solution mass transfer unit. According to the utility model, more purified water can be obtained in a smaller space, and meanwhile, the waste heat can further evaporate non-pure water solution to obtain pure liquid water resources.

Description

Technical Field

[0001] The utility model relates to the field of electrochemistry, and more specifically, to a non-pure aqueous solution direct electrolysis hydrogen production system 000 with phase change mass transfer enhancement. Background Art

[0002] Hydrogen energy has the advantages of wide sources, storability, multiple uses, zero carbon and zero pollution, and high energy density. It is a key component of the future energy field. At present, there are two ways to obtain hydrogen energy by electrolyzing water. One is to directly use natural seawater, river water or lake water. Taking seawater electrolysis for hydrogen production as an example, it has the following problems: (1) The composition of seawater is complex, and its composition varies with factors such as season, climate, temperature, region and human activities. Therefore, seawater direct hydrogen electrolysis devices in different regions are not directly compatible; (2) Cl in seawater - The highest content, in the electrolysis reaction, Cl - Can be oxidized in the oxygen evolution reaction to produce ClO which is toxic, environmentally harmful and corrosive - and Cl2; (3) When hydrogen is produced directly from seawater, H + and OH - The ion concentration is too small or the buffer molecules cannot transport OH at the cathode and anode. - and H + , resulting in low electrolysis efficiency, so additional additives or ion exchange membranes are required, which greatly increases costs. At the same time, the exchange membrane is highly sensitive to impurities and may have deactivation or maintenance costs; (4) Due to local pH differences during electrolysis, precipitation with calcium and magnesium ions may occur, and acid precipitation treatment is required, which incurs additional costs. The second is to desalinate various aqueous solutions to produce pure water for use in electrolytic cells. Still taking seawater as an example, it is necessary to go through the seawater desalination process. This method requires the establishment of a seawater desalination plant on the coast, which greatly increases costs in terms of construction, operation, manpower, and maintenance; and it is difficult to use offshore wind power coupling on a large scale to form an in-situ integrated green hydrogen production system to achieve stable storage of renewable energy. Utility Model Content

[0003] The purpose of the utility model is to overcome the shortcomings of the prior art and provide a system for direct electrolysis of non-pure aqueous solutions for hydrogen production with enhanced phase change mass transfer. The energy consumption of electrolysis will be comparable to that of industrial electrolysis of pure water for hydrogen production. No additional energy consumption is required for desalination / purification of the non-pure aqueous solution. A large amount of waste heat generated during the electrolysis process can be used to enhance the phase change mass transfer process of the system itself, so that more pure water can be obtained in a smaller space. At the same time, the waste heat can further evaporate the non-pure aqueous solution to obtain pure liquid water resources.

[0004] The purpose of the utility model is achieved through the following solutions:

[0005] A system for producing hydrogen by direct electrolysis of impure aqueous solution with enhanced phase change mass transfer, comprising:

[0006] A non-pure aqueous solution hydrogen production subsystem and a phase change mass transfer enhancement subsystem, wherein the non-pure aqueous solution hydrogen production subsystem is connected to the phase change mass transfer enhancement subsystem; the phase change mass transfer enhancement subsystem comprises a non-pure aqueous solution insulation cabin, a non-pure aqueous solution mass transfer device is arranged inside the non-pure aqueous solution insulation cabin, and a non-pure aqueous solution inlet, a non-pure aqueous solution outlet and a pure water vapor outlet are arranged on the non-pure aqueous solution insulation cabin; the non-pure aqueous solution inlet is connected to valve one, and the non-pure aqueous solution outlet is connected to valve two; the non-pure aqueous solution mass transfer device comprises non-pure aqueous solution mass transfer units A1~An, and a waterproof and breathable layer is attached to the surface of the non-pure aqueous solution mass transfer units A1~An.

[0007] Furthermore, the non-pure aqueous solution insulation chamber is provided with an insulation layer.

[0008] Furthermore, the thermal insulation layer includes a vacuum sandwich structure or a thermal insulation coating directly coated on the wall surface.

[0009] Furthermore, the structure of each of the non-pure aqueous solution mass transfer units A1 to An is a plate type or a hollow fiber type.

[0010] Furthermore, the waterproof and breathable layer includes any one of a porous TPU film, a PDMS film and a PTFE film.

[0011] Furthermore, the waterproof and breathable layer includes a porous waterproof and breathable mass transfer layer prepared by using graphene, PVDF particles, PTFE particles and by spraying, screen printing, and electrostatic adsorption.

[0012] Furthermore, the non-pure aqueous solution insulation chamber comprises a non-pure aqueous solution insulation chamber made of 316L stainless steel corrosion-resistant material.

[0013] Furthermore, the shapes of the non-pure aqueous solution insulation chamber include cylindrical and square.

[0014] Furthermore, the non-pure aqueous solution includes any one of seawater, salt lake water, chemical water, river water, lake water, wastewater, swamp water, domestic sewage and mine water.

[0015] The beneficial effects of the utility model include:

[0016] The utility model provides a non-pure aqueous solution direct electrolysis hydrogen production system based on the newly discovered principle, which integrates an energy supply module, an electrolysis hydrogen production module, a hydrogen collection module, an oxygen collection module, a non-pure aqueous solution mass transfer module, a non-pure aqueous solution insulation module, and a cooling module to form a novel non-pure aqueous solution direct electrolysis hydrogen production process system.

[0017] The non-pure aqueous solution direct electrolysis hydrogen production system with phase change mass transfer enhancement constructed by the utility model has the following functions: 1) pure water for hydrogen production can be directly obtained from various non-pure waters such as sea water, river water, lake water, silt, swamp, etc. through electrolytes; 2) the waste heat generated by electrolysis heats the non-pure aqueous solution, enhances the mass transfer rate between the non-pure aqueous solution and the electrolyte, so that the electrolysis system can obtain more pure water for hydrogen production in a smaller mass transfer space; 3) the excess heat generated by the system is exchanged with the non-pure aqueous solution, providing the system with a stable temperature; 4) after the non-pure aqueous solution is heated by heat exchange, it will further volatilize to generate pure water vapor, which can be collected to obtain pure water.

[0018] The utility model fundamentally solves the problem that the complex ion composition causes the ion exchange membrane to fail, the catalyst to be deactivated, and alkaline precipitation and toxic gases to be generated; at the same time, the heat exchange between the non-pure aqueous solution and the electrolyte can be used to effectively utilize the waste heat of the electrolysis system, which plays a role in enhancing the phase change mass transfer of the non-pure aqueous solution and maintaining the temperature of the electrolyte in the system; at the same time, it helps the future hydrogen energy conversion to be free from time and space constraints, and provides strong technical support for the direct hydrogen production of non-pure aqueous solutions; and when producing hydrogen in coastal areas or oceans, it produces high-purity hydrogen and co-produces pure water resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 A schematic diagram of the structure of a non-pure aqueous solution direct hydrogen production system with enhanced phase change mass transfer provided by an embodiment of the utility model;

[0021] Figure 2 The test results of water phase change migration rate at different temperatures;

[0022] Figure 3 The test results of the electrolysis system stability at 60°C;

[0023] In the figure, 1-power supply module; 2-electrolyzer; 3-hydrogen separator; 4-hydrogen purifier; 5-hydrogen regulating valve; 6-hydrogen check valve; 7-hydrogen cooler; 8-hydrogen storage tank; 9-oxygen separator; 10-oxygen purifier; 11-oxygen regulating valve; 12-oxygen check valve; 13-oxygen cooler; 14-oxygen storage tank; 15-cooling water tank; 16-cooling water pump; 17-non-pure aqueous solution insulation cabin; 18-non-pure aqueous solution mass transfer device; 19-non-pure aqueous solution inlet; 20-valve one; 21-valve two; 22-non-pure aqueous solution outlet; 23-pure water vapor outlet; 24-electrolyte buffer tank; 25-pressure relief valve; 26-external electrolyte storage tank; 27-control valve; A1~An-non-pure aqueous solution mass transfer unit. DETAILED DESCRIPTION

[0024] All features disclosed in all embodiments in this specification, or steps in all methods or processes implicitly disclosed, except for mutually exclusive features and / or steps, can be combined and / or expanded or replaced in any manner.

[0025] The utility model provides a non-pure aqueous solution direct electrolysis hydrogen production system with phase change mass transfer enhancement, including an energy supply module, an electrolysis hydrogen production module, a hydrogen collection module, an oxygen collection module, a non-pure aqueous solution mass transfer module, a non-pure aqueous solution insulation module and a cooling module. Figure 1 As shown, the energy supply module is a power supply module 1, and the power supply module 1 is used to provide power to the electrolysis hydrogen production module.

[0026] Before the reaction starts, the electrolyte is pumped into the external electrolyte storage tank 26, and the electrolyte enters the electrolytic cell 2, the hydrogen separator 3, the oxygen separator 9, and the electrolyte buffer tank 24, and a certain amount of electrolyte is controlled to enter the non-pure aqueous solution mass transfer device 18. A control valve 27 is provided between the external electrolyte storage tank 26 and the electrolyte buffer tank 24, and the electrolyte buffer tank 24 is provided with a pressure relief valve 25.

[0027] When hydrogen production begins, the electrolyte in the electrolytic cell 2 undergoes a redox reaction to generate hydrogen and oxygen. If the electrolytic cell 2 is an alkaline electrolytic cell or an AEM (anion exchange membrane) electrolytic cell, the electrolyte first undergoes a reduction hydrogen evolution reaction at the cathode to generate OH - The electrolyte enters the anode through the diaphragm or anion exchange membrane and undergoes an oxidation reaction to produce oxygen. If the electrolyzer 2 is a PEM (proton exchange membrane) electrolyzer, the electrolyte now undergoes an oxidation oxygen evolution reaction at the anode to produce H + It enters the cathode through the proton exchange membrane and undergoes a reduction reaction to produce hydrogen.

[0028] The generated hydrogen and oxygen enter the hydrogen separator 3 and the oxygen separator 9 respectively. This process separates the generated hydrogen / oxygen from the mixed electrolyte or water.

[0029] The separated hydrogen and oxygen enter the hydrogen purifier 4 and the oxygen purifier 10 respectively. This process further cleans the electrolyte and water in the gas that have not been separated completely.

[0030] The cleaned hydrogen enters the hydrogen cooler 7 under the control of the hydrogen regulating valve 5 and the check valve 6 to dry and cool the hydrogen, and then is stored in the hydrogen storage tank 8. The cleaned oxygen enters the oxygen cooler 13 under the control of the oxygen regulating valve 11 and the check valve 12 to dry and cool the oxygen, and then is stored in the hydrogen storage tank 14. The purification and cooling and drying of oxygen are optional processes, depending on the demand for oxygen at the back end.

[0031] The electrolyte entering the non-pure aqueous solution mass transfer device 18 is divided into non-pure aqueous solution mass transfer units A1~An. A waterproof and breathable layer is attached to the surface of the non-pure aqueous solution mass transfer unit. The membrane layer only allows water vapor to pass through, and does not allow liquid water to penetrate and contaminate each other. When the electrolyte passes through the non-pure aqueous solution mass transfer device 18, under the action of the interface vapor pressure difference between the non-pure aqueous solution and the electrolyte, the non-pure aqueous solution undergoes vaporization on the surface of the waterproof and breathable layer to produce water vapor. The water vapor enters the electrolyte side through the waterproof and breathable layer, and under the action of the interface pressure difference, the water vapor is induced to phase change and liquefy to replenish water for the electrolyte. Therefore, the non-pure aqueous solution in the non-pure aqueous solution insulation cabin 17 can continuously replenish pure water to the electrolyte in the non-pure aqueous solution mass transfer device 18 for electrolytic hydrogen production. At the same time, since the hydrogen production system generates a large amount of heat, the high-temperature electrolyte enters the non-pure water solution mass transfer cabin 17 and exchanges heat with the low-temperature non-pure water solution, so that the non-pure water solution is heated up. The heat preservation effect of the non-pure water solution insulation cabin 17 further prevents heat from being lost to the outside. After the non-pure water solution is heated up, the vapor pressure difference between it and the electrolyte increases, further increasing the phase change mass transfer rate of the non-pure water solution to the electrolyte, so that more pure water is continuously added to the electrolyte for electrolytic hydrogen production. At the same time, since the temperature in the non-pure water solution insulation cabin 17 increases, the water is continuously evaporated outward, and pure water vapor can be further obtained, and pure water can be co-produced after condensation and liquefaction. The non-pure water solution insulation cabin 17 is also provided with a non-pure water solution inlet 19 and a non-pure water solution outlet 22, so that fresh non-pure water solution is continuously introduced / exported from the insulation cabin to balance the concentration. After exchanging heat with the non-pure water solution and obtaining pure water, the electrolyte is returned to the external electrolyte storage tank 26 for storage, replenishing pure water for the electrolysis system while preparing for the next electrolysis.

[0032] During the whole reaction process, the total amount of electrolyte is regulated by the liquid level controller. When the liquid levels in the hydrogen separator 3 and the oxygen separator 9 are reduced to a specific value, the electrolyte is continuously replenished into the system from the external electrolyte storage tank 26 through control.

[0033] In the whole system, there is also an internal circulation cooling system, which consists of a cooling water tank 15 and a cooling water pump 16, and provides cooling water for the hydrogen separator 3, the hydrogen purifier 4, the hydrogen cooler 7, the oxygen separator 9, the oxygen purifier 10, and the oxygen cooler 13.

[0034] After the reaction is completed, the electrolyte is discharged through the pressure relief valve 25.

[0035] The non-pure water solution insulation cabin in the utility model can be made of corrosion-resistant materials such as 316L stainless steel, and its structure can be various structures such as cylindrical and square. The key is the insulation layer on its wall (inner wall or outer wall), which can be composed of a vacuum interlayer or coated with an insulation coating. There are holes for the electrolyte pipeline to enter / exit the insulation cabin, which are sealed to prevent the leakage of the non-pure water container, and channels for the non-pure water solution to enter and exit are opened. In addition, there is also an outlet for pure water vapor on the non-pure water solution insulation cabin, which can be further connected to a condenser to condense and liquefy the water vapor for recycling.

[0036] The non-pure aqueous solution mass transfer unit used in the utility model can be any mass transfer device that can achieve two-phase liquid isolation but allow gas to pass, such as a commercially mature flat-plate membrane distillation reactor, a hollow fiber membrane distillation reactor, or any self-made device with two-phase independent mass transfer space isolated by a waterproof and breathable layer.

[0037] The waterproof and breathable layer in the non-pure aqueous solution mass transfer device used in the utility model can be a porous TPU film, PDMS, PTFE film or a porous waterproof and breathable mass transfer layer prepared by spraying, screen printing, and electrostatic adsorption of graphene, PVDF particles, and PTFE particles. The waterproof and breathable layer has a hydrophobic effect, allowing only water vapor to pass through, and not allowing liquid water to penetrate and pollute each other.

[0038] The electrolyte used in the utility model depends on the different electrolytic cells. If an alkaline electrolytic cell or an AEM electrolytic cell is used, an alkaline electrolyte such as a 20wt% to 40wt% KOH solution or a 20 to 30wt% NaOH solution can be used. If a PEM electrolytic cell is used, an acidic liquid electrolyte such as an H2SO4 solution, an H3PO4 solution, an HClO4 solution, etc. can be used.

[0039] The non-pure aqueous solution mentioned in the utility model includes all non-pure water resources such as sea water, river water, lake water, waste water, swamp water, domestic sewage, etc.

[0040] The technical process in the utility model can be fully automatically controlled by PID control and the like, thereby realizing full process automation of the electrolytic hydrogen production process.

[0041] The system of the utility model has the following advantages:

[0042] The utility model can directly use non-pure water solution to produce hydrogen, and collect the waste heat generated in the electrolysis process to improve the system phase change mass transfer rate, while co-producing pure water. The electrolysis energy consumption of the system is equivalent to that of industrial electrolysis of pure water, and no additional desalination / purification energy consumption is required; and the electrolysis effect is consistent with the electrolysis performance of commercial electrolyzers.

[0043] By utilizing the heat exchange between the non-pure aqueous solution and the electrolyte, on the one hand, the non-pure aqueous solution can be heated up, the phase change mass transfer rate of the system can be increased, and the replenishment rate of pure water can be increased; on the other hand, directly using the non-pure aqueous solution to cool the electrolyte can save the investment in additional equipment to cool the electrolyte, which has good benefits in the large-scale hydrogen production process.

[0044] The utility model can directly use commercial electrolytic cells and electrolytes, greatly improving the conductivity and electrochemical performance of the electrolysis system, and avoiding the direct production of hydrogen from non-pure aqueous solutions. + and OH - The problem of low transmission efficiency at the anode and cathode is caused by low concentration.

[0045] The utility model breaks through the bottleneck of traditional non-pure aqueous solution electrolysis hydrogen production, and does not require the desalination / purification process of the non-pure aqueous solution, so there is no need to build a large-scale seawater desalination plant, which greatly reduces the costs of construction, operation, manpower, maintenance, etc.

[0046] Since the water added to the electrolyte in the mass transfer device is impurity-free water in the utility model, the bottleneck of direct non-pure aqueous solution hydrogen production being restricted by factors such as time, climate, and human activities has been broken through. At the same time, the system can be used for electrolytic hydrogen production in any non-pure water environment such as river water, lake water, sludge, swamp, and river, which greatly broadens the source range of hydrogen energy and is not limited by time and space. In addition, the utility model breaks through the direct non-pure aqueous solution hydrogen production where chloride ions are oxidized to produce Cl2 or ClO - The bottleneck of corrosion and toxic substances is a green, non-toxic and environmentally friendly process system. This solution system does not contain impurity ions such as calcium ions and magnesium ions. There will be no calcium and magnesium precipitation during long-term operation, which reduces the cost of subsequent cleaning and maintenance.

[0047] The utility model can realize the internal self-circulation of electrolyte, and there is no need to additionally supplement electrolyte and pure water therein.

[0048] All devices, components and units in the utility model can use existing commercial mature objects, which greatly ensures the stability and feasibility of the system. Moreover, due to the maturity of the system, large-scale preparation can be easily and quickly realized.

[0049] The utility model makes full use of the surplus heat generated by the electrolysis system to enhance its own mass transfer and co-produce pure water, thus realizing efficient use of energy.

[0050] The utility model can realize efficient hydrogen production directly in non-pure water solution, utilize heat exchange between non-pure water solution and electrolyte, reduce system temperature, increase system phase change mass transfer rate, and co-produce pure water. On this basis, hydrogen collection module, oxygen collection module and cooling module can be added to make the system more perfect.

[0051] The utility model realizes the direct electrolysis of non-pure water to produce hydrogen, and at the same time utilizes the waste heat of the electrolysis hydrogen production system itself to increase the phase change mass transfer rate, reduce the system electrolyte temperature, and co-produce pure water.

[0052] The implementation effect verification of this utility model:

[0053] 1. If Figure 2 At 60 °C, the initial electrolyte-induced water phase transition migration rate is about 0.25 g H2O g SDE min -1 , which is significantly higher than the electrolyte induction rate at 25°C (0.175g H2O g SDE min -1 ), indicating the enhancement effect of the utility model. At the same time, at a high temperature of 60°C, the electrolysis system is at 400mA / cm 2 Stable hydrogen production for 54 hours at current density, energy consumption is about 4.4kWh / Nm 3 H2, such as Figure 3 shown.

[0054] It should be noted that within the scope of protection defined in the claims of the present utility model, the following embodiments can be combined and / or expanded or replaced in any logical way from the above specific implementation methods, such as disclosed technical principles, disclosed technical features or implicitly disclosed technical features.

[0055] Example 1

[0056] A system for producing hydrogen by direct electrolysis of impure aqueous solution with enhanced phase change mass transfer, comprising:

[0057] A non-pure aqueous solution hydrogen production subsystem and a phase change mass transfer enhancement subsystem, wherein the non-pure aqueous solution hydrogen production subsystem is connected to the phase change mass transfer enhancement subsystem; the phase change mass transfer enhancement subsystem comprises a non-pure aqueous solution insulation cabin 17, a non-pure aqueous solution mass transfer device 18 is arranged inside the non-pure aqueous solution insulation cabin 17, a non-pure aqueous solution inlet 19, a non-pure aqueous solution outlet 22 and a pure water vapor outlet 23 are arranged on the non-pure aqueous solution insulation cabin 17; the non-pure aqueous solution inlet 19 is connected to a valve one 20, and the non-pure aqueous solution outlet 22 is connected to a valve two 21; the non-pure aqueous solution mass transfer device 18 comprises non-pure aqueous solution mass transfer units A1~An, and a waterproof and breathable layer is attached to the surface of the non-pure aqueous solution mass transfer units A1~An.

[0058] Example 2

[0059] Based on Example 1, the non-pure aqueous solution insulation chamber 17 is provided with an insulation layer.

[0060] Example 3

[0061] Based on Example 2, the thermal insulation layer includes a vacuum sandwich structure or a thermal insulation coating directly coated on the wall surface.

[0062] Example 4

[0063] On the basis of Example 1, the structure of each mass transfer unit in the non-pure aqueous solution mass transfer units A1 to An is a plate type or a hollow fiber type.

[0064] Example 5

[0065] Based on Example 1, the waterproof and breathable layer includes any one of a porous TPU membrane, a PDMS membrane and a PTFE membrane.

[0066] Example 6

[0067] On the basis of Example 1, the waterproof and breathable layer includes a porous waterproof and breathable mass transfer layer prepared by using graphene, PVDF particles, PTFE particles and by spraying, screen printing, and electrostatic adsorption.

[0068] Example 7

[0069] Based on Example 1, the non-pure aqueous solution insulation chamber 17 includes a non-pure aqueous solution insulation chamber made of 316L stainless steel corrosion-resistant material.

[0070] Example 8

[0071] Based on Example 1, the shapes of the non-pure aqueous solution insulation chamber 17 include cylindrical and square.

[0072] Example 9

[0073] Based on Example 1, the non-pure aqueous solution includes any one of seawater, salt lake water, chemical water, river water, lake water, wastewater, swamp water, domestic sewage and mine water.

[0074] In addition to the above examples, those skilled in the art may obtain other embodiments based on the above disclosure or by using the knowledge or technology in the relevant field to make changes. The features of each embodiment may be interchangeable or replaced. The changes and modifications made by those skilled in the art do not depart from the spirit and scope of the present invention and should be within the scope of protection of the claims attached to the present invention.

Claims

1. A system for direct electrolysis of non-pure aqueous solution to produce hydrogen with enhanced phase change mass transfer. It is characterized in that include: A non-pure aqueous solution hydrogen production subsystem and a phase change mass transfer enhancement subsystem, wherein the non-pure aqueous solution hydrogen production subsystem is connected to the phase change mass transfer enhancement subsystem; The phase change mass transfer enhancement subsystem comprises a non-pure aqueous solution insulation chamber (17), a non-pure aqueous solution mass transfer device (18) is arranged inside the non-pure aqueous solution insulation chamber (17), and a non-pure aqueous solution inlet (19), a non-pure aqueous solution outlet (22) and a pure water vapor outlet (23) are arranged on the non-pure aqueous solution insulation chamber (17); the non-pure aqueous solution inlet (19) is connected to a valve one (20), and the non-pure aqueous solution outlet (22) is connected to a valve two (21); the non-pure aqueous solution mass transfer device (18) comprises non-pure aqueous solution mass transfer units A1~An, and a waterproof and breathable layer is attached to the surface of the non-pure aqueous solution mass transfer units A1~An.

2. The non-pure aqueous solution direct electrolysis hydrogen production system with phase change mass transfer enhancement according to claim 1, It is characterized in that The non-pure aqueous solution insulation chamber (17) is provided with an insulation layer.

3. The system for producing hydrogen by direct electrolysis of non-pure aqueous solution with enhanced phase change mass transfer according to claim 2, It is characterized in that The thermal insulation layer includes a vacuum sandwich structure or a thermal insulation coating directly coated on the wall surface.

4. The system for producing hydrogen by direct electrolysis of non-pure aqueous solution with enhanced phase change mass transfer according to claim 1, It is characterized in that The structure of each of the non-pure aqueous solution mass transfer units A1 to An is a plate type or a hollow fiber type.

5. The system for producing hydrogen by direct electrolysis of non-pure aqueous solution with enhanced phase change mass transfer according to claim 1, It is characterized in that The waterproof and breathable layer includes any one of a porous TPU film, a PDMS film and a PTFE film.

6. The system for producing hydrogen by direct electrolysis of non-pure aqueous solution with enhanced phase change mass transfer according to claim 1, It is characterized in that The waterproof and breathable layer comprises a porous waterproof and breathable mass transfer layer which is prepared by using graphene, PVDF particles, and PTFE particles through spraying, screen printing, and electrostatic adsorption.

7. The system for producing hydrogen by direct electrolysis of non-pure aqueous solution with enhanced phase change mass transfer according to claim 1, It is characterized in that The non-pure aqueous solution insulation chamber (17) comprises a non-pure aqueous solution insulation chamber made of 316L stainless steel corrosion-resistant material.

8. The system for producing hydrogen by direct electrolysis of non-pure aqueous solution with enhanced phase change mass transfer according to claim 1, It is characterized in that The shapes of the non-pure aqueous solution insulation chamber (17) include cylindrical and square.

9. The system for producing hydrogen by direct electrolysis of non-pure aqueous solution with enhanced phase change mass transfer according to claim 1, It is characterized in that The non-pure aqueous solution includes any one of sea water, salt lake water, chemical water, river water, lake water, waste water, swamp water, domestic sewage and mine water.

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