An electrolysis device and method with low bubble energy consumption using circulating flowing electrolyte

Abstract

The present invention provides an electrolysis device and method with low bubble energy consumption using circulating electrolyte. The electrolysis device includes an electrolysis system, a switching valve system, a circulation pump, a flow meter, and a gas separation and purification system, wherein: the electrolysis system is connected in a closed loop with the circulation pump and the flow meter in sequence, and the gas separation and purification system is connected to the electrolysis system; the electrolysis system includes an electrolytic cell and a liquid storage tank, and a plurality of electrode plates and liquid circulation pipes are arranged in the electrolytic cell. The electrolysis method includes steps such as continuously wetting the surface of the electrode plates, continuously circulating the electrolyte, electrolytically preparing hydrogen and oxygen, and separating and purifying hydrogen and oxygen. The electrolysis device and method of the present invention can not only greatly improve the electrolysis efficiency, save the electrolysis energy consumption, but also be applicable to large-scale electrolysis systems, and are expected to be coupled with the industrial hydrogen production industry in China, which has great significance for the development of the green hydrogen industry in China.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production by electrolysis of water, and particularly relates to an electrolysis device and method with low bubble energy consumption using circulating flow electrolyte. Background Art

[0002] As a clean, carbon-free, flexible, efficient, and secondary energy source with rich application scenarios and an important industrial raw material, hydrogen energy has broad development prospects. Internationally, many countries and regions have started to layout the hydrogen energy development route. The European Union, Japan, the United States, and South Korea have all formulated hydrogen energy development strategies. In China, hydrogen energy has been incorporated into the national "14th Five-Year Plan" and the Outline of the Long-Term Goals for 2035.

[0003] However, there are still many problems in hydrogen production by electrolysis of water, such as high energy consumption and poor stability. In the traditional electrolysis process, a large number of bubbles are generated on the surface of the electrode plate. The bubbles adhering to the surface of the electrode plate reduce the effective area of the electrode, increase the overpotential, and thus cause large energy losses.

[0004] Therefore, developing a low-energy-consumption electrolysis method for hydrogen production by electrolysis of water with low bubbles or even no bubbles is of great significance for the field of hydrogen production by electrolysis of water and the realization of the national hydrogen energy long-term goal.

[0005] CN218561641U discloses an efficient hydrogen production device by electrolysis of water, including an electrolytic cell and a cover plate. Two stirring components are arranged inside the electrolytic cell. An anode plate and a cathode plate are respectively arranged at both ends of the bottom of the cover plate, and a diaphragm frame is arranged at the bottom. This utility model is provided with an electrolytic cell, a stirring component, a cover plate, an anode plate, a cathode plate, an ion diaphragm, a liquid inlet pipe, a feeding pipe, a flow control valve, an exhaust pipe, and a collection box, which can configure the corresponding dose of electrolyte to be mixed with pure water according to the amount of pure water to be electrolyzed as needed, so as to improve the conductivity of pure water and improve the efficiency of hydrogen production by electrolysis of water. This patent precisely increases the conductivity of the electrolyte to improve the electrolysis efficiency, but this method is not an efficient one. It still cannot avoid the problem of high energy consumption during electrolysis. Therefore, starting from reducing the electrolysis energy consumption and improving the electrolysis efficiency is the most beneficial solution.

[0006] CN14657586A discloses an electrode assembly and device for electrolyzing water. The electrode assembly of the device includes a first electrode, a second electrode, and a porous diaphragm disposed between the first electrode and the second electrode. The porous diaphragm is configured to suck electrolyte through capillary self-priming effect, so that the generated hydrogen and oxygen are directly separated in gaseous form without forming bubbles. Through this electrode assembly for electrolyzing water, the hydrogen production efficiency can be improved. Although the method proposed in this patent can reduce the energy consumption during electrolysis, it only describes an electrode equipment method and cannot achieve the coupling of a large-scale electrolysis system. At the same time, due to the high precision requirements of its equipment, it can only be in the laboratory small-scale test stage at present and cannot be applied to industrial production in a short time.

[0007] Therefore, there is an urgent need for an electrolysis device and method that can not only reduce electrolysis energy consumption, improve electrolysis efficiency, but also achieve the coupling of a large-scale electrolysis system and be applied to industrial production. Summary of the Invention

[0008] To solve the above problems, the present invention provides an electrolysis device and method with low bubble energy consumption using circulating electrolyte. By setting a liquid storage tank and a liquid circulation pipe at the upper part of the electrolysis cell body, the electrolyte is continuously circulated to ensure that the surface of the electrode plate is in a wet state, so as to ensure that the electrolysis reaction can proceed normally. At the same time, there will be no large bubble energy loss, which can not only improve the electrolysis efficiency and thus save electrolysis energy consumption, but also achieve the coupling of a large-scale electrolysis system.

[0009] Therefore, the first object of the present invention is to provide an electrolysis device with low bubble energy consumption using circulating electrolyte, including an electrolysis system, a switch valve system, a circulation pump, a flow meter, and a gas separation and purification system. The electrolysis system is connected in a closed loop with the circulation pump and the flow meter in sequence, and the gas separation and purification system is connected to the gas outlet of the electrolysis system, wherein:

[0010] The electrolysis system includes an electrolysis cell at the lower part and a liquid storage tank at the upper part. The electrolysis cell and the liquid storage tank store electrolyte. A plurality of anode electrode plates and cathode electrode plates arranged at intervals are provided in the electrolysis cell, and a plurality of liquid circulation pipes are provided at the upper part of each electrode plate; a plurality of extension sections corresponding to the positions of the liquid circulation pipes are provided at the connection between the liquid storage tank and the liquid circulation pipes;

[0011] The switch valve system includes a tank liquid outlet valve, a liquid storage tank liquid filling port valve, a hydrogen and oxygen gas outlet valve, a hydrogen secondary drying and purification inlet valve, an oxygen secondary drying and purification inlet valve, and a tank liquid replacement port valve;

[0012] The gas separation and purification system includes a gas dryer, a hydrogen-oxygen gas separator, and a secondary drying and purification device connected in sequence. The gas dryer is connected to the gas outlet of the electrolysis system. The secondary drying and purification device includes a hydrogen secondary drying and purification device and an oxygen secondary drying and purification device, which are respectively connected to the hydrogen and oxygen gas outlets of the hydrogen-oxygen gas separator.

[0013] According to the present invention, the electrolytic cell and the liquid circulation pipe are made of stainless steel. The diameter of the liquid circulation pipe is set to be 0.2 m to 0.4 m, and the spacing is set to be 0.2 m to 0.4 m.

[0014] Further, a liquid flow meter and a switch valve are provided above the liquid circulation pipe.

[0015] Further, the outlet of the liquid circulation pipe is set to an inclined long cone structure, and the inclination angles on both sides are set to 15°.

[0016] According to the present invention, a stainless steel liquid baffle with a length of 0.1 m to 0.3 m is provided at the upper left corner of the electrolytic cell.

[0017] According to the present invention, a liquid outlet of the cell body is provided at the right end of the bottom of the electrolytic cell, a gas outlet of the cell body is provided at the left end of the top, and a liquid changing port of the cell body is provided at the left end of the bottom.

[0018] According to the present invention, a liquid inlet of the liquid storage tank is provided at the middle side of the top of the liquid storage tank, and a liquid adding port of the liquid storage tank is provided at the left end of the top.

[0019] According to the present invention, the length of the extension section is set to be 0.4 m to 1 m.

[0020] The second object of the present invention is to provide an electrolysis method with low bubble energy consumption using circulating electrolyte to solve the problem of large electrolysis energy consumption caused by the generation of bubbles during the electrolysis process of existing electrolysis devices and improve the electrolysis efficiency. The electrolysis method includes the following steps:

[0021] Step 1: Continuously wet the surface of the electrode plate:

[0022] First, put an appropriate amount of electrolyte into the liquid adding port of the liquid storage tank, open and adjust the switch valve above the liquid circulation pipe, and ensure that the flow rate of each liquid circulation pipe is the same; the electrolyte flows from the liquid storage tank through the liquid circulation pipe and naturally flows into the electrode plate in the electrolytic cell, so that the electrode plate is always kept in a wet state;

[0023] Step 2: Continuously circulate the electrolyte:

[0024] After the electrolyte wets the surface of the electrode plate, it flows to the bottom of the electrolytic cell; when the liquid level of the electrolyte just touches the lowermost end of the electrode plate, the valve of the liquid outlet of the cell body is opened, and at the same time, the circulation pump is turned on. The electrolyte is discharged from the liquid outlet of the cell body and, under the action of the circulation pump, is injected into the liquid storage tank again through the liquid inlet of the liquid storage tank for continuous circulation;

[0025] Step Three: Electrolytic preparation of hydrogen and oxygen:

[0026] The power supply is turned on, and an electrolytic reaction occurs on the electrode plates in the electrolytic cell, electrolyzing the electrolyte flowing through the electrode plates, thereby preparing and generating hydrogen and oxygen;

[0027] Step Four: Separation and purification of hydrogen and oxygen:

[0028] The hydrogen-oxygen gas outlet valve is opened. After the hydrogen and oxygen generated by electrolysis in Step Three are discharged from the gas outlet of the cell body of the electrolytic cell, they first pass through the gas dryer, then enter the hydrogen-oxygen gas separator, and then the separated hydrogen and oxygen enter the hydrogen secondary drying and purification device and the oxygen secondary drying and purification device respectively for secondary drying and purification. Finally, the hydrogen and oxygen after secondary drying and purification are collected and stored respectively.

[0029] According to the present invention, the volume of the electrolyte in the liquid storage tank in Step One satisfies normal operation for 10 minutes without turning on the circulation pump.

[0030] According to the present invention, the liquid flow rate in the liquid circulation pipe in Step One is 5 L / min to 18 L / min.

[0031] According to the present invention, the circulation flow rate of the circulation pump in Step Two is the sum of the total flow rates of each liquid circulation pipe.

[0032] According to the present invention, the working pressure of the circulation pump in Step Two is 0.2 MPa to 0.6 MPa.

[0033] According to the present invention, the liquid level of the electrolyte in the electrolytic cell in Step Three is kept at the lowermost end of the electrode plate and does not submerge the electrode plate at the same time.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] By arranging a liquid storage tank and a liquid circulation pipe at the upper part of the electrolytic cell body, the electrolytic solution flows from the liquid storage tank at the upper part of the electrolytic cell through the liquid circulation pipe and naturally flows into the electrodes in the electrolytic cell, so that the electrodes are always kept in a wet state. The electrolytic solution that flows to the bottom of the cell body after wetting the surface of the electrode plates is injected into the liquid storage tank again for circulation under the action of a circulation pump. The gases (hydrogen and oxygen) generated by the reaction are discharged from the upper part of the cell body, and after passing through a primary drying device, they enter a hydrogen-oxygen separation device. The separated hydrogen and oxygen respectively enter a secondary drying and purification device and are then collected and stored. By using the electrolytic device and method of the present invention for hydrogen production by electrolyzing water, it can be ensured that the hydrogen and oxygen generated by electrolysis are completely in a gaseous state, avoiding a large amount of energy consumption caused by bubbles, greatly improving the electrolysis efficiency, thus saving the electrolysis energy consumption in production, reducing the production cost, and being beneficial to energy conservation and environmental protection; in addition, the electrolytic device and method of the present invention can also be applied to large-scale electrolysis systems, thereby increasing the hydrogen production amount of industrial equipment and realizing the green industrial production of hydrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 FIG. is a schematic process flow diagram of low-bubble energy consumption electrolysis using circulating electrolytic solution according to the present invention.

[0037] Figure 2 FIG. is a schematic structural diagram of the electrolysis system 1 according to the present invention.

[0038] Figure 3 FIG. is a side sectional view of the electrolysis system 1 according to the present invention.

[0039] Figure 4 FIG. is a front view of the liquid circulation pipe 1103 according to the present invention.

[0040] Figure 5 FIG. is a side view of the liquid circulation pipe 1103 according to the present invention.

[0041] Figure 6 FIG. is a graph showing the electrolysis voltage fluctuation results of the example and the comparative example electrolysis devices in Example 3 of the present invention under the same constant current.

[0042] Description of the drawing numbers:

[0043] 1 - electrolysis system;

[0044] 11 - electrolytic cell; 1101 - anode electrode plate; 1102 - cathode electrode plate; 1103 - liquid circulation pipe; 1104 - liquid flow

[0045] meter; 1105 - liquid baffle;

[0046] 12 - liquid storage tank; 1201 - electrolytic solution; 1202 - extension section;

[0047] 101 - Liquid outlet of the tank body; 102 - Liquid inlet of the liquid storage tank; 103 - Liquid filling port of the liquid storage tank; 104 - Gas outlet of the tank body; 105 - Liquid changing port of the tank body;

[0048] 2 - Switch valve system;

[0049] 201 - Valve for the liquid outlet of the tank body; 202 - Valve for the liquid filling port of the liquid storage tank; 203 - Valve for the hydrogen - oxygen gas outlet; 204 - Valve for the inlet of the secondary hydrogen drying and purification; 205 - Valve for the inlet of the secondary oxygen drying and purification; 206 - Valve for the liquid changing port of the tank body;

[0050] 3 - Circulation pump; 4 - Flowmeter; 5 - Gas dryer; 6 - Hydrogen - oxygen gas separator; 7 - Secondary hydrogen drying and purification device; 8 - Secondary oxygen drying and purification device. Detailed implementation mode

[0051] The present invention will be further described in detail below in conjunction with embodiments. It should be understood that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the protection scope of the present invention. Some non - essential improvements and adjustments made by those skilled in the art based on the content of the present invention still fall within the protection scope of the present invention.

[0052] Embodiment 1: An electrolysis device with low - bubble energy consumption using circulating electrolyte

[0053] As Figure 1 shown, the electrolysis device with low - bubble energy consumption using circulating electrolyte of the present invention includes: an electrolysis system 1, a switch valve system 2, a circulation pump 3, a flowmeter 4, and a gas separation and purification system. The electrolysis system 1, the circulation pump 3, and the flowmeter 4 are connected in a closed loop in sequence. The gas separation and purification system is connected to the gas outlet of the electrolysis system 1. Among them: the electrolysis system 1 is used for electrolyzing to generate hydrogen and oxygen; the switch valve system 2 is used to control the inflow and outflow of the electrolyte and hydrogen - oxygen gas, including a valve 201 for the liquid outlet of the tank body, a valve 202 for the liquid filling port of the liquid storage tank, a valve 203 for the hydrogen - oxygen gas outlet, a valve 204 for the inlet of the secondary hydrogen drying and purification, a valve 205 for the inlet of the secondary oxygen drying and purification, and a valve 206 for the liquid changing port of the tank body; the circulation pump 3 is connected to the electrolytic cell below the electrolysis system 1 and the liquid storage tank above, and is used to make the electrolyte flowing out naturally from the electrolytic cell be injected into the liquid storage tank again through the circulation pump 3 for circulation, so that the electrolysis system 1 can continuously generate hydrogen and oxygen in a cycle; the flowmeter 4 is used to measure the total flow of the electrolyte flowing through the electrolysis system 1.

[0054] The gas separation and purification system includes a gas dryer 5, a hydrogen-oxygen gas separator 6, and secondary drying and purification devices 7 and 8 connected in sequence. The gas dryer 5 is connected to the gas outlet of the electrolysis system 1. The secondary drying and purification devices include a hydrogen secondary drying and purification device 7 and an oxygen secondary drying and purification device 8, which are respectively connected to the hydrogen and oxygen gas outlets of the hydrogen-oxygen gas separator 6. The gas dryer 5 is used for the primary drying of hydrogen and oxygen generated and discharged in the electrolysis system 1. The hydrogen-oxygen gas separator 6 is used for separating the hydrogen and oxygen after the primary drying. The hydrogen secondary drying and purification device 7 and the oxygen secondary drying and purification device 8 are respectively used for the secondary drying and purification of the separated hydrogen and oxygen. A hydrogen secondary drying and purification inlet valve 204 is provided at the inlet of the hydrogen secondary drying and purification device 7, and an oxygen secondary drying and purification inlet valve 205 is provided at the inlet of the oxygen secondary drying and purification device 8.

[0055] As Figure 2 and Figure 3 shown, the electrolysis system 1 includes an electrolytic cell 11 at the lower part and a liquid storage tank 12 at the upper part. An electrolytic solution 1201 is stored in the electrolytic cell 11 and the liquid storage tank 12. The electrolytic cell 11 is made of stainless steel. During the operation of the electrolysis device, the reaction part of the cell body is in a non-immersed state, so a large number of bubbles will not be generated during the electrolysis process, thus ensuring a high electrolysis efficiency.

[0056] A number of anode electrode plates 1101 and cathode electrode plates 1102 arranged at intervals are provided in the electrolytic cell 11 for electrolyzing the electrolytic solution 1201 to generate hydrogen and oxygen. A number of liquid circulation pipes 1103 are provided at the upper parts of each anode electrode plate 1101 and cathode electrode plate 1102 for circulating the electrolytic solution to keep the whole electrode in a liquid state all the time. The material of the liquid circulation pipe 1103 is preferably stainless steel. The pipe diameter is set to 0.2 m - 0.4 m, and the spacing is set to 0.2 m - 0.4 m. The number of liquid circulation pipes 1103 on each electrode plate can be set according to the width of the electrode plate, for example, 3 - 8. Further, as Figure 4 and Figure 5 shown, the outlet of the liquid circulation pipe 1103 is set to an inclined long cone structure, with the inclination angles on both sides set to 15°. This can make the outlet of the electrolytic solution large and the flow rate uniform, and is used to ensure that the

[0057] surface of the electrode plate can be better wetted.

[0058] At the connection between the liquid storage tank 12 and the liquid circulation pipe 1103, there are a number of extension sections 1202 corresponding to the position of the liquid circulation pipe 1103. The length of the extension section 1202 is set to be 0.4 m to 1 m, which is used to ensure that the electrolyte 1201 at the inlet of the liquid circulation pipe 1103 has a certain potential energy, so that the electrolyte 1201 can flow out normally and flow into and wet the electrode plate.

[0059] Above the liquid circulation pipe 1103, there are a liquid flow meter 1104 and a switch valve (not shown in the figure). When the electrolysis device is operating, by adjusting the switch valve and observing the liquid flow meter 1104 at the same time, the flow rate of the electrolyte flowing through the liquid circulation pipe 1103 can be adjusted, and it is ensured that the flow rate of each liquid circulation pipe 1103 is the same and the entire electrode is completely wetted. In addition, at the upper left corner of the electrolytic cell 11, there is a stainless steel liquid baffle 1105 with a length of 0.1 m to 0.3 m, which is used to prevent the electrolyte from splashing out from the left gas outlet.

[0060] At the right end of the bottom of the electrolytic cell 11, there is a tank liquid outlet 101, at the left end of the top, there is a tank gas outlet 104, and at the left end of the bottom, there is a tank liquid replacement port 105; at the middle side of the top of the liquid storage tank 12, there is a liquid storage tank liquid inlet 102, and at the left end of the top, there is a liquid storage tank liquid addition port 103. Among them, at the tank liquid outlet 101, there is a tank liquid outlet valve 201, at the liquid storage tank liquid addition port 103, there is a liquid storage tank liquid addition port valve 202, at the tank gas outlet 104, there is a hydrogen-oxygen gas outlet valve 203, and at the tank liquid replacement port 105, there is a tank liquid replacement port valve 206.

[0061] The working principle of the electrolysis device of the present invention is as follows:

[0062] Before the electrolysis device of the present invention starts to operate, an appropriate amount of electrolyte 1201 is put into the liquid storage tank 12 at the upper part of the electrolysis system 1. The electrolyte 1201 flows down naturally from the liquid storage tank 12 through the liquid circulation pipe 1103, and then naturally flows onto the electrode plate below the liquid circulation pipe 1103, keeping the electrode plate in a wet state at all times. Under the electrolysis of the electrode plate, hydrogen and oxygen are generated; then the electrolyte 1201 flows into the bottom of the electrolytic cell 11 and flows out from the electrolyte circulation pump inlet 101 at the right end of the bottom. Under the action of the circulation pump 3, it is injected into the liquid storage tank 12 again for circulation. The generated hydrogen and oxygen are discharged from the tank gas outlet 104 at the upper left end of the electrolytic cell 11, and after passing through the primary drying device 5, they enter the hydrogen-oxygen separation device 6; the separated hydrogen and oxygen enter the hydrogen secondary drying and purification device 7 and the oxygen secondary drying and purification device 8 respectively and are collected and stored.

[0063] Example 2: Electrolysis Method with Low Bubble Energy Consumption Using Recirculating Electrolyte

[0064] Based on the electrolysis device with low bubble energy consumption in Example 1, this example aims to provide an electrolysis method with low bubble energy consumption using recirculating electrolyte. This electrolysis method can not only ensure that the generated hydrogen and oxygen are completely in a gaseous state, avoiding a large amount of energy consumption caused by bubbles, thereby significantly improving the electrolysis efficiency; but also be applicable to large-scale electrolysis systems, thus increasing the hydrogen production of industrial equipment and realizing the large-scale industrial production of hydrogen. The electrolysis method includes the following steps.

[0065] Step 1: Continuously wet the surface of the electrode plate

[0066] First, put an appropriate amount of electrolyte 1201 into the liquid inlet 103 of the liquid storage tank 12. Open and adjust the switch valve above the liquid circulation pipe 1103, and at the same time observe the liquid flowmeter 1104 to ensure that the flow rate of each liquid circulation pipe 1103 is the same. The electrolyte 1201 flows out of the liquid storage tank 12 through the liquid circulation pipe 1103 and naturally flows onto the electrode plate in the electrolytic cell 11, keeping the electrode plate moist at all times.

[0067] Among them, the volume of the electrolyte 1201 in the liquid storage tank 12 should at least ensure normal operation for 10 minutes without turning on the circulation pump 3. In addition, to ensure that the electrode plate can always be in a completely wet state, it is necessary to adjust the opening of the flowmeter on the liquid circulation pipe 1103. According to the size of different electrode plates and the number of liquid circulation pipes 1103, it is best to control the liquid flow rate in the liquid circulation pipe 1103 at 5 L / min - 18 L / min.

[0068] Step 2: Continuously circulate the electrolyte

[0069] After the electrolyte 1201 wets the surface of the electrode plate, it flows to the bottom of the electrolytic cell 11. When the liquid level of the electrolyte 1201 just touches the lower end of the electrode plate, open and adjust the valve 201 at the liquid outlet of the cell body, and at the same time turn on the circulation pump 3. The electrolyte 1201 is discharged from the liquid outlet 101 of the cell body and, under the action of the circulation pump 3, is injected into the liquid storage tank 12 again through the liquid inlet 102 of the liquid storage tank for continuous circulation.

[0070] Among them, the circulation flow rate of the circulation pump 3 should be the sum of the total flow rates of each liquid circulation pipe 1103 to ensure the normal progress of electrolyte circulation. In addition, to ensure the normal circulation and flow of the electrolyte, the working pressure of the circulation pump 3 is 0.2 MPa - 0.6 MPa, which is used to ensure that the electrolyte in the electrolytic cell 11 can smoothly flow back to the liquid storage tank 12 for circulation at this working pressure.

[0071] Step 3: Electrolytic preparation of hydrogen and oxygen

[0072] Connect the power supply. Electrolysis reactions occur on the anode electrode plate 1101 and the cathode electrode plate 1102 in the electrolytic cell 11, and the electrolyte 1201 flowing through the electrode plates is electrolyzed to produce hydrogen and oxygen. Among them, by further adjusting the valve 201 at the liquid outlet of the cell body, the liquid level of the electrolyte 1201 in the electrolytic cell 11 is still maintained at the lowermost end of the electrode plate, and at the same time, the electrode plate cannot be submerged, so as to ensure that most of the hydrogen and oxygen generated during electrolysis exist in the form of gas, and avoid generating additional bubble resistance.

[0073] Step 4: Separation and purification of hydrogen and oxygen

[0074] Open the hydrogen-oxygen gas outlet valve 203. After the hydrogen and oxygen generated by electrolysis in Step 3 are discharged from the gas outlet 104 of the cell body of the electrolytic cell 11, they first pass through the gas dryer 5, then enter the hydrogen-oxygen gas separator 6, and then the separated hydrogen and oxygen enter the hydrogen secondary drying and purification device 7 and the oxygen secondary drying and purification device 8 respectively for secondary drying and purification. Finally, the dried and purified hydrogen and oxygen are collected and stored respectively.

[0075] Example 3: Comparative experiment on the electrolysis efficiency between the electrolysis system of the present invention and a common alkaline water electrolytic cell

[0076] In this example, it is used to verify the progressiveness of the electrolysis device and method of the present invention in improving electrolysis efficiency and saving electrolysis energy consumption. In the comparative experiment of this example, the electrolysis device described in Example 1 of the present invention is used in the example, and a common alkaline water electrolytic cell is used in the comparative example for electrolysis experiments respectively. Among them, the electrolytes in the example and the comparative example both use a KOH solution with a concentration of 30%. Another variable in the comparative experiment of this example is the electrolysis method. Among them, the electrolyte circulates in the example, and the electrodes are immersed in the electrolytic cell in the comparative example, and a gas-liquid separator is used to collect hydrogen. Keep other operating conditions the same. Among them, the operating current in both methods is 50 mA, and the electrolysis time is 200 s. Measure the electrolysis voltage and the hydrogen production efficiency of the example and the comparative example. The fluctuations of the electrolysis voltage of the example and the comparative example under the same constant current are as Figure 6 shown, and the experimental results of the hydrogen production capacity and electrolysis energy consumption under the same conditions are shown in Table 1.

[0077] Table 1

[0078]

[0079] Figure 6The results show that at the same current, since no bubbles are generated in the electrolysis system of the embodiment, its average electrolysis voltage is -4.4 V; while the comparative example uses traditional alkaline water electrolysis. Due to the generation of a large number of bubbles during its electrolysis process, a relatively high bubble overpotential is caused, and its average electrolysis voltage is -5.5 V. This shows that when using the electrolysis system described in the embodiment for electrolysis, its electrolysis voltage, that is, the electrolysis energy consumption, is reduced by about 20%. It can be seen that compared with traditional alkaline water electrolysis, the electrolysis device and method of the present invention have made great progress in saving electrolysis energy consumption.

[0080] The results in Table 1 show that although the hydrogen production capacity of the electrolysis system of the embodiment is slightly lower than that of the traditional alkaline water electrolysis system of the comparative example, it is significantly superior to the comparative example in terms of energy consumption and electrolysis efficiency. Therefore, the electrolysis device and method of the present invention are expected to accelerate their coupling with China's industrial hydrogen production industry, which is of great significance to the development of China's green hydrogen industry and the realization of the carbon neutrality strategy.

[0081] In summary, the electrolysis device and method with low bubble energy consumption using a circulating flowing electrolyte of the present invention, by designing a new electrolysis system structure, enables the electrolyte to naturally flow from the upper liquid storage tank of the electrolytic cell into the electrodes in the electrolytic cell, keeping the electrodes moist at all times. In addition, through the action of the circulating pump, the electrolyte circulates, ensuring the continuous progress of the electrolysis reaction. During the electrolysis process, the generated hydrogen and oxygen gases are completely in a gaseous state, without the generation of bubbles, avoiding a large amount of energy consumption caused by bubbles. Therefore, the electrolysis of the electrolysis device and method of the present invention can not only greatly improve the electrolysis efficiency, save electrolysis energy consumption, thereby reducing production costs, which is of great significance for energy conservation and environmental protection; in addition, the electrolysis device and method of the present invention can also be applied to large-scale electrolysis systems, and are expected to be coupled with China's industrial hydrogen production industry, which is of great significance to the development of China's green hydrogen industry and the realization of the carbon neutrality strategy.

[0082] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. An electrolysis device with low bubble energy consumption using a circulating flowing electrolyte, characterized in that, It includes an electrolysis system, a switching valve system, a circulation pump, a flow meter, and a gas separation and purification system. The electrolysis system, the circulation pump, and the flow meter are connected in a closed loop in sequence. The gas separation and purification system is connected to the gas outlet of the electrolysis system, where: The electrolysis system includes an electrolytic cell at the lower part and a liquid storage tank at the upper part. The electrolytic cell and the liquid storage tank store electrolyte. A number of anode electrode plates and cathode electrode plates arranged at intervals are provided in the electrolytic cell. A number of liquid circulation pipes are provided above each electrode plate. A number of extension sections corresponding to the positions of the liquid circulation pipes are provided at the connection between the liquid storage tank and the liquid circulation pipes. The electrolyte flows from the liquid storage tank above the electrolytic cell through the liquid circulation pipes and naturally flows onto the electrode plates in the electrolytic cell, keeping the electrode plates wet at all times. After wetting the surface of the electrode plates, the electrolyte flowing into the bottom of the electrolytic cell is injected into the liquid storage tank again for circulation under the action of the circulation pump. The liquid level of the electrolyte in the electrolytic cell is kept at the lowermost end of the electrode plates and does not submerge the electrode plates. The switching valve system includes a tank liquid outlet valve, a liquid storage tank liquid filling port valve, a hydrogen-oxygen gas outlet valve, a hydrogen secondary drying and purification inlet valve, an oxygen secondary drying and purification inlet valve, and a tank liquid replacement port valve. The gas separation and purification system includes a gas dryer, a hydrogen-oxygen gas separator, and a secondary drying and purification device connected in sequence. The gas dryer is connected to the gas outlet of the electrolysis system. The secondary drying and purification device includes a hydrogen secondary drying and purification device and an oxygen secondary drying and purification device, and is respectively connected to the hydrogen and oxygen gas outlets of the hydrogen-oxygen gas separator.

2. The electrolysis device with low bubble energy consumption according to claim 1, characterized in that, The electrolytic cell and the liquid circulation pipes are made of stainless steel. The pipe diameter of the liquid circulation pipes is set to be 0.2 m to 0.4 m, and the spacing is set to be 0.2 m to 0.4 m.

3. The electrolysis device with low bubble energy consumption according to claim 2, characterized in that, A liquid flow meter and a switching valve are provided above the liquid circulation pipes.

4. The electrolysis device with low bubble energy consumption according to claim 2, characterized in that, The outlet of the liquid circulation pipe is set to be an inclined long cone structure, and the inclination angles on both sides are set to be 15°.

5. The electrolysis device with low bubble energy consumption according to claim 1, characterized in that, A stainless steel liquid baffle with a length of 0.1 m to 0.3 m is provided at the upper left corner of the electrolytic cell.

6. The electrolysis device with low bubble energy consumption according to claim 1, characterized in that, A tank liquid outlet is provided at the right end of the bottom of the electrolytic cell, a tank gas outlet is provided at the left end of the top, and a tank liquid replacement port is provided at the left end of the bottom.

7. The electrolysis device with low bubble energy consumption according to claim 1, characterized in that A liquid storage tank liquid inlet is provided in the middle of the top of the liquid storage tank, and a liquid storage tank liquid filling port is provided at the left end of the top.

8. The electrolysis device with low bubble energy consumption according to claim 1, characterized in that, The length of the extension section is set to be 0.4 m to 1 m.

9. The electrolysis method of the electrolysis device with low bubble energy consumption according to any one of claims 1-8, characterized in that, The electrolysis method includes the following steps: Step 1: Continuously wet the surface of the electrode plates: First, put an appropriate amount of electrolyte into the liquid storage tank, open and adjust the switching valve above the liquid circulation pipes, and ensure that the flow rate of each liquid circulation pipe is the same. The electrolyte flows from the liquid storage tank through the liquid circulation pipes and naturally flows onto the electrode plates in the electrolytic cell, keeping the electrode plates wet at all times. Step 2: Continuously circulate the electrolyte: After the electrolyte wets the surface of the electrode plate, it flows to the bottom of the electrolytic cell; when the liquid level of the electrolyte just touches the lowermost end of the electrode plate, the valve of the liquid outlet of the cell body is opened, and at the same time, the circulation pump is turned on. The electrolyte is discharged from the electrolytic cell and, under the action of the circulation pump, is injected into the liquid storage tank again for continuous circulation; Step Three: Electrolytic preparation of hydrogen and oxygen: The power supply is connected, and an electrolytic reaction occurs on the electrode plates in the electrolytic cell to electrolyze the electrolyte flowing through the electrode plates, thereby producing hydrogen and oxygen; Step Four: Separation and purification of hydrogen and oxygen: The hydrogen-oxygen gas outlet valve is opened. After the hydrogen and oxygen generated by electrolysis in Step Three are discharged from the electrolytic cell, they first pass through the gas dryer, then enter the hydrogen-oxygen gas separator. Subsequently, the separated hydrogen and oxygen enter the hydrogen secondary drying and purification device and the oxygen secondary drying and purification device respectively for secondary drying and purification. Finally, the hydrogen and oxygen after secondary drying and purification are collected and stored separately.

10. The electrolysis method with low bubble energy consumption according to claim 9, characterized in that, The volume of the electrolyte in the liquid storage tank in Step One satisfies normal operation for 10 minutes without turning on the circulation pump.

11. The electrolysis method with low bubble energy consumption according to claim 9, characterized in that, The liquid flow rate in the liquid circulation pipe in Step One is 5 L / min to 18 L / min.

12. The electrolysis method with low bubble energy consumption according to claim 9, characterized in that, The circulation flow rate of the circulation pump in Step Two is the sum of the total flow rates of each liquid circulation pipe.

13. The electrolysis method with low bubble energy consumption according to claim 9, characterized in that, The working pressure of the circulation pump in Step Two is 0.2 MPa to 0.6 MPa.

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