An anion exchange membrane water electrolysis system

Abstract

This utility model relates to the field of water electrolysis technology, and provides an anion exchange membrane water electrolysis system, including: an electrolyzer device with an anode region and a cathode region; an anode gas-liquid separator connected to the outlet of the anode region of the electrolyzer device; a cathode gas-liquid separator connected to the outlet of the cathode region of the electrolyzer device; an anode alkali storage tank connected to the inlet of the anode region via an anode inlet pipe; an anode inlet valve provided on the anode inlet pipe; a cathode alkali storage tank connected to the inlet of the cathode region via a cathode inlet pipe; a buffer alkali storage tank, with both the anode and cathode alkali storage tanks connected to the buffer alkali storage tank via buffer pipes; the anode alkali storage tank connected to the buffer alkali storage tank via a first circulation pipe; the cathode alkali storage tank connected to the buffer alkali storage tank via a second circulation pipe; a supply module for providing alkali and / or pure water to the anode and cathode alkali storage tanks; and a computer control system. Advantages: Improved stability of electrolyzed water.

Description

Technical Field

[0001] This utility model relates to the field of hydrogen production by water electrolysis, and more specifically, to an anion exchange membrane water electrolysis system. Background Technology

[0002] Electrolysis of water for hydrogen production is a core pathway for green hydrogen production, with broad technological prospects. It is estimated that the global installed capacity will exceed 100GW in the next 5 years, and the cost is expected to drop to below RMB 20 / kg, helping decarbonization in industries, transportation, energy storage, and other fields. Among them, anion exchange membrane (AEM) water electrolysis technology has emerged with significant advantages: (1) low cost, using non-precious metal catalysts (nickel / iron-based), reducing material costs by more than 50% compared to proton exchange membrane (PEM) water electrolysis for hydrogen production; (2) low-alkaline operation, requiring only <1M KOH electrolyte, reducing dependence on corrosive media, and reducing system maintenance difficulty compared to alkaline (ALK) water electrolysis for hydrogen production; (3) high adaptability, supporting ambient temperature and distributed hydrogen production, and adapting to fluctuating wind and solar power sources. AEM technology will become a key driving force for the large-scale application of green hydrogen.

[0003] In the AEM water electrolysis hydrogen production process, the oxygen evolution reaction (OER) occurs on the anode side, and the reaction equation is shown below:

[0004] 4OH - →2H₂O + O₂ + 4e -

[0005] The hydrogen evolution reaction (HER) occurs on the cathode side, and the reaction equation is shown below:

[0006] 4H2O+4e - →4OH - +2H2

[0007] In different experimental designs, the concentrations of the alkali solution at the cathode and anode may be the same or different. According to the mechanisms of the anodic OER reaction and the cathode HER reaction, as the reaction proceeds, fresh alkali solution needs to be replenished; otherwise, the alkali concentration on the anode side will gradually decrease, while the alkali concentration on the cathode side will gradually increase. This change in alkali concentration will lead to a decline in the performance of both the cathode and anode sides.

[0008] Currently, there are two common methods for replenishing the alkali solution during AEM water electrolysis hydrogen production testing:

[0009] (1) The cathode and anode share a common alkali replenishment tank. Although this alkali replenishment scheme can offset the difference between the gradual increase in cathode alkali concentration and the gradual decrease in anode alkali concentration during AEM water electrolysis to some extent, this alkali replenishment scheme can only meet the requirement of the same alkali concentration for both cathode and anode during AEM water electrolysis testing, and cannot meet the requirements of testing methods where the cathode and anode alkali concentrations are different.

[0010] (2) Separate alkali replenishment tanks are set up for the cathode and anode. This alkali replenishment scheme can meet the requirements of the same alkali concentration for both the cathode and anode, as well as the requirements of different alkali concentrations for both the cathode and anode. However, as the AEM water electrolysis reaction proceeds, the alkali concentration at the cathode continuously increases, while that at the anode continuously decreases. Therefore, fresh alkali and pure water need to be continuously added manually to balance the changes in alkali concentration caused by the AEM water electrolysis process. This scheme has low alkali concentration adjustment efficiency, large fluctuations in alkali concentration, and a large consumption of fresh alkali.

[0011] Furthermore, both methods (1) and (2) mentioned above suffer from low utilization rates in the recycling of electrolyte in the electrolytic cell. Moreover, the alkali in the anode and cathode alkali replenishment tanks, whether for alkali preparation before electrolysis or concentration adjustment during electrolysis, is usually achieved by directly adding concentrated alkali and pure water to the replenishment tanks. The significant concentration difference between the high-concentration alkali and the pure water replenishment causes uneven mixing of the alkali concentration when the replenishment enters the cathode and anode electrolytic cell inlet tanks, thus affecting the stability of the AEM electrolysis test process. Utility Model Content

[0012] The present invention aims to overcome at least one defect (deficiency) of the prior art and provide an anion exchange membrane electrolysis water system for improving the stability of electrolyzed water.

[0013] The technical solution adopted by this utility model is to provide an anion exchange membrane water electrolysis system, comprising:

[0014] An electrolytic cell apparatus has an anode region and a cathode region, each of which is provided with an inlet and an outlet.

[0015] Anode gas-liquid separator, connected to the outlet of the anode zone of the electrolytic cell unit;

[0016] The cathode gas-liquid separator is connected to the outlet of the cathode zone of the electrolytic cell unit.

[0017] An anode alkali solution storage tank is connected to the inlet of the anode zone via an anode inlet pipeline; an anode inlet valve is installed on the anode inlet pipeline.

[0018] A cathode alkali solution storage tank is connected to the inlet of the cathode zone via a cathode inlet pipe; a cathode inlet valve is provided on the cathode inlet pipe.

[0019] A buffer alkali solution storage tank is provided, wherein both the anode alkali solution storage tank and the cathode alkali solution storage tank are connected to the buffer alkali solution storage tank via buffer pipelines; the anode alkali solution storage tank is connected to the buffer alkali solution storage tank via a first circulation pipeline; and the cathode alkali solution storage tank is connected to the buffer alkali solution storage tank via a second circulation pipeline.

[0020] The buffer pipeline is equipped with a buffer valve; the first circulation pipeline is equipped with a first circulation valve; the second circulation pipeline is equipped with a second circulation valve.

[0021] The liquid supply module is used to provide alkali solution and / or pure water to the anode alkali solution storage tank and the cathode alkali solution storage tank. The concentration of alkali solution in the liquid supply module is higher than the concentration of alkali solution in the anode alkali solution storage tank, the cathode alkali solution storage tank and the buffer alkali solution storage tank.

[0022] The computer control system is electrically connected to the anode inlet valve, cathode inlet valve, buffer valve, first circulation valve, second circulation valve, and liquid supply module.

[0023] In this technical solution, valves are used to control the on / off state of corresponding pipelines. The computer-controlled liquid supply module provides alkali solution and / or pure water to the anode and cathode alkali solution storage tanks, ensuring that the alkali solution in both tanks reaches the target concentration. The alkali solution in the anode alkali solution storage tank enters the anode zone of the electrolytic cell through pipelines for electrolysis; the alkali solution in the cathode alkali solution storage tank enters the cathode zone of the electrolytic cell through pipelines for electrolysis.

[0024] During electrolysis, oxygen generated in the anode region and the electrolytic alkali solution are separated in the anode gas-liquid separator. The oxygen leaves the electrolysis system, and the remaining alkali solution enters the alkali buffer tank for reuse. Similarly, hydrogen generated in the cathode region and the electrolytic alkali solution are separated in the cathode gas-liquid separator. The hydrogen leaves the electrolysis system, and the remaining alkali solution enters the alkali buffer tank for reuse. The alkali solutions from the cathode and anode regions are mixed in the alkali buffer tank and then flow into the anode alkali storage tank through the first circulation pipeline, and into the cathode alkali storage tank through the second circulation pipeline for use. If the alkali concentrations in the anode and cathode regions are the same, they can be directly supplied to the anode and cathode for electrolysis. If the alkali concentrations in the anode and cathode regions are different, a high-concentration alkali solution or pure water is supplied through the liquid supply module to adjust to the target concentration.

[0025] Compared to the traditional method of directly adding high-concentration alkali solution and pure water to the cathode and cation alkali solution storage tanks, in this scheme, the liquid entering the cathode and cation alkali solution storage tanks is alkali solution recovered from the cathode and cation regions, which has a certain concentration. Even if adjustments are needed, the concentration will not fluctuate too much, ensuring the stability of the alkali solution concentration supplied to the cathode and anode regions of the electrolyzer, and also ensuring the stability of the electrolysis process.

[0026] Furthermore, this solution recovers the electrolyte from the anode and cathode areas of the electrolytic cell into a buffer tank for reuse, improving the utilization rate of the alkali solution, reducing the consumption of fresh alkali solution, saving materials, and lowering costs. Additionally, this solution uses a computer control system to control the valve opening and closing, improving control efficiency.

[0027] Furthermore, the liquid supply module includes a replenishing alkali storage tank and a pure water storage tank. The replenishing alkali storage tank is connected to the anode alkali storage tank via an alkali replenishment pipeline; the pure water storage tank is connected to the cathode alkali storage tank via a pure water replenishment pipeline.

[0028] An alkali replenishment branch and a pure water replenishment branch are provided between the alkali replenishment pipeline and the pure water replenishment pipeline; the alkali replenishment branch and the pure water replenishment branch are both connected to the alkali replenishment pipeline and the pure water replenishment pipeline;

[0029] Both the alkali replenishment branch and the pure water replenishment branch are equipped with branch valves. An alkali replenishment valve is provided on the side of the alkali replenishment branch near the anode alkali storage tank on the alkali replenishment pipeline, and a pure water replenishment valve is provided on the side of the pure water replenishment branch near the cathode alkali storage tank on the pure water replenishment pipeline. The computer control system is electrically connected to the branch valves, the alkali replenishment valves, and the pure water replenishment valves.

[0030] In this technical solution, the supplementary alkali storage tank is used to hold a high-concentration alkali solution, which has a higher concentration than that in the anode, cathode, and buffer alkali storage tanks. The anode and cathode alkali storage tanks are connected to the supplementary alkali storage tank and the pure water storage tank. Whether preparing the alkali solution to the target concentration before electrolysis or adjusting the concentration of the alkali solution in the anode and cathode storage tanks during electrolysis, this can be achieved through the flexible mixing ratio of the liquids in the supplementary tank and the pure water tank, thus improving the efficiency of alkali concentration adjustment.

[0031] Furthermore, the anode alkali storage tank is connected to the buffer alkali storage tank via a third circulation pipeline, and the cathode alkali storage tank is connected to the buffer alkali storage tank via a fourth circulation pipeline; a third circulation valve is provided on the third circulation pipeline, and a fourth circulation valve is provided on the fourth circulation pipeline; both the third circulation valve and the fourth circulation valve are connected to the computer control system.

[0032] In this technical solution, before electrolysis, the first circulation pipeline, in conjunction with the third circulation pipeline, allows the alkali solution to circulate in the anode alkali solution storage tank and the buffer alkali solution storage tank, thereby thoroughly mixing the high-concentration alkali solution and pure water to achieve the target concentration of alkali solution. The second circulation pipeline, in conjunction with the fourth circulation pipeline, allows the alkali solution to circulate in the cathode alkali solution storage tank and the buffer alkali solution storage tank, which also facilitates mixing. This allows for thorough mixing of the anode and cathode alkali solution storage tanks without the need for a stirring device, providing a stable concentration of alkali solution for electrolysis in the electrolytic cell.

[0033] Furthermore, a first circulation pump is provided on the first circulation pipeline, a second circulation pump is provided on the second circulation pipeline, a third circulation pump is provided on the third circulation pipeline, and a fourth circulation pump is provided on the fourth circulation pipeline; an anode inlet pump is provided on the anode inlet pipeline, and a cathode inlet pump is provided on the cathode inlet pipeline; an alkali replenishment pump is provided on the alkali replenishment pipeline, and a pure water replenishment pump is provided on the pure water replenishment pipeline.

[0034] The first circulation pump, the second circulation pump, the third circulation pump, the fourth circulation pump, the anode inlet pump, the cathode inlet pump, the alkali replenishment pump, and the pure water replenishment pump are all electrically connected to the computer control system.

[0035] In this technical solution, the flow rates of the first and third circulating pumps are preferably the same; the flow rate control of the second and fourth circulating pumps is preferably kept consistent to reduce the probability of pump damage.

[0036] Furthermore, it also includes a waste liquid module, which includes a waste liquid storage tank. The buffer alkali storage tank is connected to the waste liquid storage tank through a waste liquid pipeline. The waste liquid pipeline is equipped with a waste liquid valve and a waste liquid pump, both of which are electrically connected to the computer control system.

[0037] In this technical solution, the liquids from the anode and cathode alkaline solution storage tanks, alkaline solution buffer tanks, and anode and cathode gas-liquid separators can all be discharged to the waste liquid storage tank through waste liquid pipelines, which facilitates the adjustment of liquid levels and cleaning.

[0038] Furthermore, the anode gas-liquid separator, cathode gas-liquid separator, anode alkali storage tank, cathode alkali storage tank, buffer alkali storage tank, and waste liquid storage tank are all equipped with concentration detectors, which are electrically connected to the computer control system.

[0039] The concentration detector is used to detect the concentration of the alkaline solution.

[0040] Furthermore, the anode gas-liquid separator, cathode gas-liquid separator, anode alkali storage tank, cathode alkali storage tank, buffer alkali storage tank, and waste liquid storage tank are all equipped with a liquid level detection component, which is electrically connected to the computer control system.

[0041] Furthermore, the liquid level detection component includes a high-level liquid level detector, a middle-level liquid level detector, and a low-level liquid level detector arranged sequentially from top to bottom.

[0042] In this technical solution, the liquid level in the storage tank is precisely controlled by setting different liquid level detectors.

[0043] Furthermore, the anode gas-liquid separator, cathode gas-liquid separator, anode alkali storage tank, cathode alkali storage tank, buffer alkali storage tank, and waste liquid storage tank are all equipped with alarms, and the high-level liquid level detector and the low-level liquid level detector are both electrically connected to the alarms.

[0044] In this technical solution, when there is too much or too little liquid in the storage tank, the alarm will sound, which facilitates the adjustment of the liquid volume in the storage tank and ensures the smooth progress of electrolysis.

[0045] Furthermore, the anode gas-liquid separator, cathode gas-liquid separator, anode alkali storage tank, cathode alkali storage tank, buffer alkali storage tank, and waste liquid storage tank are all equipped with temperature detectors, which are electrically connected to the computer control system. The temperature detectors allow for real-time monitoring of the liquid temperature within the storage tanks.

[0046] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0047] (1) Compared with the traditional method of directly adding high-concentration alkali solution and pure water to the cathode and cation alkali solution storage tank, this utility model uses the setting of alkali solution buffer storage tank. The liquid entering the cathode and anode alkali solution storage tank is the alkali solution recovered from the cathode and anode areas, which has a certain concentration. Even if adjustments are needed, the concentration will not fluctuate too much, thus ensuring the stability of the alkali solution concentration supplied to the cathode and anode areas of the electrolytic cell, and also ensuring the stability of the electrolysis process.

[0048] (2) In this invention, the electrolyte in the anode and cathode areas of the electrolytic cell is recovered to the buffer tank for continued use, which improves the utilization rate of the alkali solution, reduces the consumption of fresh alkali solution, saves materials, and reduces costs. Furthermore, this invention uses a computer control system to control the opening and closing of the valves, thereby improving control efficiency.

[0049] (3) This utility model enables the anode and cathode alkaline solution storage tanks to achieve full mixing without the need for a stirring device, thereby improving the stability of the electrolyzed water by providing a stable concentration of alkaline solution for electrolysis. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the anion exchange membrane water electrolysis system of this utility model.

[0051] Figure 2 This is a schematic diagram of the buffer alkali storage tank of this utility model.

[0052] Figure label:

[0053] Electrolytic cell 100, anode gas-liquid separator 200, cathode gas-liquid separator 300;

[0054] Anode alkali storage tank 400, anode inlet valve 410, anode inlet pump 420;

[0055] 500 cathode alkali storage tank, 510 cathode inlet valve, 520 cathode inlet pump;

[0056] The system includes: a buffer alkali storage tank 600; a first circulation pipeline 610; a first circulation valve 611; a first circulation pump 612; a second circulation pipeline 620; a second circulation valve 621; a second circulation pump 622; a third circulation pipeline 630; a third circulation valve 631; a third circulation pump 632; a fourth circulation pipeline 640; a fourth circulation valve 641; a fourth circulation pump 642; a buffer pipeline 650; a buffer valve 651; a high-level liquid level detector 661; a medium-level liquid level detector 662; a low-level liquid level detector 663; a concentration detector 670; and a temperature detector 680.

[0057] 700, 710, 711, 712, 713, 714; 700, 712, 713, 714.

[0058] Pure water storage tank 800, pure water replenishment pipeline 810, pure water replenishment branch 811, pure water replenishment valve 812, pure water replenishment pump 813;

[0059] Waste liquid storage tank 900, waste liquid valve 910, waste liquid pump 920. Detailed Implementation

[0060] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this invention. To better illustrate the following embodiments, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0061] Example 1

[0062] like Figure 1 As shown, this embodiment provides an anion exchange membrane water electrolysis system, including:

[0063] An electrolytic cell apparatus 100 has an anode region and a cathode region, each of which is provided with an inlet and an outlet.

[0064] Anode gas-liquid separator 200 is connected to the outlet of the anode zone of electrolytic cell device 100;

[0065] The cathode gas-liquid separator 300 is connected to the outlet of the cathode region of the electrolytic cell device 100;

[0066] An anode alkali storage tank 400 is connected to the inlet of the anode zone via an anode inlet pipe; an anode inlet valve 410 is provided on the anode inlet pipe.

[0067] The cathode alkali solution storage tank 500 is connected to the inlet of the cathode area through a cathode inlet pipe; the cathode inlet pipe is equipped with a cathode inlet pump 520.

[0068] A buffer alkali solution storage tank 600 is provided, wherein the anode alkali solution storage tank 400 and the cathode alkali solution storage tank 500 are both connected to the buffer alkali solution storage tank 600 via a buffer pipeline 650; the anode alkali solution storage tank 400 is connected to the buffer alkali solution storage tank 600 via a first circulation pipeline 610; and the cathode alkali solution storage tank 500 is connected to the buffer alkali solution storage tank 600 via a second circulation pipeline 620.

[0069] The buffer pipeline 650 is provided with a buffer valve 651; the first circulation pipeline 610 is provided with a first circulation valve 611; the second circulation pipeline 620 is provided with a second circulation valve 621;

[0070] The liquid supply module is used to provide alkali solution and / or pure water to the anode alkali solution storage tank 400 and the cathode alkali solution storage tank 500. The concentration of alkali solution in the liquid supply module is higher than the concentration of alkali solution in the anode alkali solution storage tank 400, the cathode alkali solution storage tank 500 and the buffer alkali solution storage tank 600.

[0071] The computer control system is electrically connected to the anode inlet valve 410, the cathode inlet pump 520, the buffer valve 651, the first circulation valve 611, the second circulation valve 621, and the liquid supply module.

[0072] Preferably, the liquid supply module includes a replenishing alkali storage tank 700 and a pure water storage tank 800. The replenishing alkali storage tank 700 is connected to the anode alkali storage tank 400 through an alkali replenishing pipeline 710; the pure water storage tank 800 is connected to the cathode alkali storage tank 500 through a pure water replenishing pipeline 810.

[0073] An alkali replenishment branch line 711 and a pure water replenishment branch line 811 are provided between the alkali replenishment pipeline 710 and the pure water replenishment pipeline 810; the alkali replenishment branch line 711 and the pure water replenishment branch line 811 are both connected to the alkali replenishment pipeline 710 and the pure water replenishment pipeline 810.

[0074] Both the alkali replenishment branch 711 and the pure water replenishment branch 811 are equipped with branch valves 713. An alkali replenishment valve 712 is provided on the side of the alkali replenishment branch 711 near the anode alkali storage tank 400 on the alkali replenishment pipeline 710. A pure water replenishment valve 812 is provided on the side of the pure water replenishment branch 811 near the cathode alkali storage tank 500 on the pure water replenishment pipeline 810. The computer control system is electrically connected to the branch valves 713, alkali replenishment valves 712 and pure water replenishment valves 812.

[0075] Preferably, the anode alkali storage tank 400 is connected to the buffer alkali storage tank 600 via a third circulation pipeline 630, and the cathode alkali storage tank 500 is connected to the buffer alkali storage tank 600 via a fourth circulation pipeline 640; the third circulation pipeline 630 is equipped with a third circulation valve 631, and the fourth circulation pipeline 640 is equipped with a fourth circulation valve 641; both the third circulation valve 631 and the fourth circulation valve 641 are connected to a computer control system.

[0076] Preferably, the first circulation pipeline 610 is equipped with a first circulation pump 612, the second circulation pipeline 620 is equipped with a second circulation pump 622, the third circulation pipeline 630 is equipped with a third circulation pump 632, and the fourth circulation pipeline 640 is equipped with a fourth circulation pump 642; the anode inlet pipeline is equipped with an anode inlet pump 420, and the cathode inlet pipeline is equipped with a cathode inlet pump 520; the alkali replenishment pipeline 710 is equipped with an alkali replenishment pump 714, and the pure water replenishment pipeline 810 is equipped with a pure water replenishment pump 813;

[0077] The first circulation pump 612, the second circulation pump 622, the third circulation pump 632, the fourth circulation pump 642, the anode inlet pump 420, the cathode inlet pump 520, the alkali replenishment pump 714, and the pure water replenishment pump 813 are all electrically connected to the computer control system.

[0078] Preferably, it also includes a waste liquid module, which includes a waste liquid storage tank 900. The buffer alkali storage tank 600 is connected to the waste liquid storage tank 900 through a waste liquid pipeline. The waste liquid pipeline is equipped with a waste liquid valve 910 and a waste liquid pump 920. Both the waste liquid valve 910 and the waste liquid pump 920 are electrically connected to the computer control system.

[0079] Preferably, the anode gas-liquid separator 200, the cathode gas-liquid separator 300, the anode alkali storage tank 400, the cathode alkali storage tank 500, the buffer alkali storage tank 600, and the waste liquid storage tank 900 are all equipped with a concentration detector 670, which is electrically connected to the computer control system.

[0080] Preferably, the anode gas-liquid separator 200, cathode gas-liquid separator 300, anode alkali storage tank 400, cathode alkali storage tank 500, buffer alkali storage tank, and waste liquid storage tank 900 are all equipped with liquid level detection components, which are electrically connected to the computer control system. Specifically, the liquid level detection components include a high-level liquid level detector 660, a mid-level liquid level detector 662, and a low-level liquid level detector 663 arranged sequentially from top to bottom.

[0081] Preferably, the anode gas-liquid separator 200, the cathode gas-liquid separator 300, the anode alkali storage tank 400, the cathode alkali storage tank 500, the buffer alkali storage tank, and the waste liquid storage tank 900 are all equipped with alarms and temperature detectors 680. The high-level liquid level detector 661 and the low-level liquid level detector 663 are both electrically connected to the alarms; the temperature detector 680 is electrically connected to the computer control system.

[0082] For example, one method of using the above-mentioned anion exchange membrane electrolysis water system is as follows, which is applicable when the required alkali concentration is the same in the anode and cathode regions of the electrolyzer:

[0083] Solution addition. Add 2M KOH alkali solution to replenish alkali solution storage tank 700 to 4 / 5 of the total tank volume; add pure water to pure water storage tank 800 to 4 / 5 of the total volume.

[0084] Add 1M alkali solution to both the anode and cathode alkali storage tanks 500. Open alkali solution replenishment valve 712, pure water replenishment valve 812, and branch valve 713 on alkali solution replenishment branch 711. Start alkali solution replenishment pump 714 at a flow rate of 100 ml / min for 30 minutes, then close the pump and branch valve 713 on alkali solution replenishment branch 711. Open branch valve 713 on pure water replenishment branch 811. Start pure water replenishment pump 813 at a flow rate of 100 ml / min for 30 minutes, then close the valves and pump. Set the system temperature to 60℃.

[0085] AEM water electrolysis begins. Open the anode inlet valve 410, cathode inlet pump 520, buffer valve 651, first circulation valve 611, and second circulation valve 621. Start the anode inlet pump 420, cathode inlet pump 520, first circulation pump 612, and second circulation pump 622, setting the flow rate of each pump to 100 mL / min. O2 generated at the anode and the decreasing concentration of the alkaline solution on the anode side flow from the outlet of the electrolytic cell's anode area to the anode gas-liquid separator 200. O2 leaves the test system from the top gas pipe outlet, and the alkaline solution returning from the anode side (theoretically calculated KOH concentration approximately 0.9 M) enters the buffer alkaline solution storage tank 600. H2 generated at the cathode and the increasing concentration of the alkaline solution flow from the outlet of the electrolytic cell's cathode area to the cathode gas-liquid separator 300. Similar to the anode side, H2 leaves the test system from the top gas pipe outlet, and the alkaline solution returning from the cathode (theoretically calculated KOH concentration approximately 1.1 M) enters the buffer alkaline solution storage tank 600. In the buffer alkali storage tank 600, the alkali solution with decreased concentration on the cathode side (alkali concentration of approximately 0.9M) is mixed with the alkali solution with increased concentration on the anode side (alkali concentration of approximately 1.1M), and the concentration returns to approximately 1M. The alkali buffer solution with a concentration of approximately 1M then re-enters the anode alkali storage tank 400 and the cathode alkali storage tank 500, completing the multi-stage alkali concentration regulation.

[0086] Using the above method, approximately 2.7 mol of KOH can be saved per unit time.

[0087] AEM water electrolysis is complete. Open waste liquid valve 910, start waste liquid pump 920, set the flow rate to 200 mL / min, and discharge all alkaline solutions from anode gas-liquid separator 200, cathode gas-liquid separator 300, anode alkaline solution storage tank 400, and cathode alkaline solution storage tank 500 through buffer alkaline solution storage tank 600 and waste liquid pipeline into waste liquid storage tank 900. Reopen pure water replenishment valve 812, alkaline solution replenishment valve 712, and branch valve 713 on pure water replenishment branch 811, start pure water replenishment pump 813, set the flow rate to 200 mL / min, inject pure water into each storage tank and pipeline for cleaning, and finally discharge it through the waste liquid module.

[0088] For example, another method of using the above-mentioned anion exchange membrane electrolysis water system is as follows, which is applicable when the required alkali concentrations in the anode and cathode regions of the electrolyzer are different:

[0089] Add the solution. The steps are the same as described above.

[0090] Add a 0.5M alkali solution to the anode alkali storage tank 400 and a 1M alkali solution to the cathode alkali storage tank 500. Open the alkali replenishment valve 712, start the alkali replenishment pump 714 at a flow rate of 50 mL / min, maintain for 15 minutes, and then close the pump. Open the branch valve 713 on the pure water replenishment branch 811, start the pure water replenishment pump 813 at a flow rate of 150 mL / min, maintain for 15 minutes, and then close the valve and pump. At this point, the alkali concentration in the anode alkali storage tank 400 is approximately 0.5M. Open the pure water replenishment valve 812 and the branch valve 713 on the alkali replenishment branch 711, start the alkali replenishment pump 714 at a flow rate of 100 mL / min, maintain for 15 minutes, and then close the pump, the branch valve 713 on the alkali replenishment branch 711, and the pump. Start the pure water replenishment pump 813 at a flow rate of 100 mL / min, maintain for 15 minutes, and then close the valve and pump. At this time, the concentration of alkali solution in cathode alkali storage tank 500 is approximately 1 M.

[0091] Before starting the AEM water electrolysis test, the heating and solution mixing are performed. First circulation valve 611 and third circulation valve 631 are opened, and first circulation pump 612 and second circulation pump 622 are started. The alkali solution in the anode alkali storage tank 400 is circulated between this tank and the buffer alkali storage tank 600, thoroughly mixing the high-concentration alkali solution and pure water. After mixing is complete, third circulation valve 631 is closed, and third circulation pump 632 is stopped. All the alkali solution in the buffer alkali storage tank 600 is then transferred to the anode alkali storage tank 400. Similarly, the high-concentration alkali solution and water in the cathode alkali storage tank 500 are thoroughly mixed.

[0092] AEM water electrolysis begins. Open the anode inlet valve 410, cathode inlet pump 520, buffer valve 651, first circulation valve 611, and second circulation valve 621. Start the anode inlet pump 420, cathode inlet pump 520, first circulation pump 612, and second circulation pump 622, setting the flow rate of each pump to 100 mL / min. O2 generated at the anode and the alkaline solution with decreasing concentration on the anode side flow from the outlet of the electrolytic cell's anode zone to the anode gas-liquid separator 200. O2 leaves the test system from the top gas pipe outlet, and the anode-side reflux alkaline solution enters the buffer alkaline solution storage tank 600. H2 generated at the cathode and the alkaline solution with increasing concentration flow from the outlet of the electrolytic cell's cathode zone to the cathode gas-liquid separator 300. Similar to the anode side, H2 leaves the test system from the top gas pipe outlet, and the cathode reflux alkaline solution enters the buffer alkaline solution storage tank 600. In the buffer alkaline solution storage tank 600, the alkaline solution with decreasing concentration on the cathode side mixes with the alkaline solution with increasing concentration on the anode side, resulting in an alkaline concentration of approximately 0.75 M. After the mixed alkaline solution is introduced into the anode and cathode alkaline solution storage tanks, the alkaline solution replenishment valve 712 and the branch valve 713 on the pure water replenishment branch 811 are opened, and the pure water replenishment pump 813 is started. The computer control system controls the pure water replenished into the anode alkaline solution storage tank 400, so that the alkaline solution concentration in the tank is 0.5M. Similarly, a high-concentration alkaline solution is added to the cathode alkaline solution storage tank 500, so that the alkaline solution concentration in the tank is 1M.

[0093] AEM electrolysis of water is complete. The steps are the same as described above.

[0094] Using the above method, approximately 2.03 mol of KOH can be saved per unit time.

[0095] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the technical solution of this utility model, and are not intended to limit the specific implementation of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. An anion exchange membrane water electrolysis system, characterized by, include: An electrolytic cell apparatus has an anode region and a cathode region, each of which is provided with an inlet and an outlet. Anode gas-liquid separator, connected to the outlet of the anode zone of the electrolytic cell unit; The cathode gas-liquid separator is connected to the outlet of the cathode zone of the electrolytic cell unit. An anode alkali solution storage tank is connected to the inlet of the anode zone via an anode inlet pipeline; the anode inlet pipeline is equipped with an anode inlet valve. A cathode alkali solution storage tank is connected to the inlet of the cathode zone via a cathode inlet pipe; a cathode inlet valve is provided on the cathode inlet pipe. A buffer alkali solution storage tank is provided, wherein both the anode alkali solution storage tank and the cathode alkali solution storage tank are connected to the buffer alkali solution storage tank via buffer pipelines; the anode alkali solution storage tank is connected to the buffer alkali solution storage tank via a first circulation pipeline; and the cathode alkali solution storage tank is connected to the buffer alkali solution storage tank via a second circulation pipeline. The buffer pipeline is equipped with a buffer valve; the first circulation pipeline is equipped with a first circulation valve; the second circulation pipeline is equipped with a second circulation valve. A liquid supply module is used to supply alkali and / or pure water to the anode alkali storage tank and the cathode alkali storage tank, wherein the concentration of alkali in the liquid supply module is higher than the concentration of alkali in the anode alkali storage tank, the cathode alkali storage tank and the buffer alkali storage tank; The computer control system is electrically connected to the anode inlet valve, cathode inlet valve, buffer valve, first circulation valve, second circulation valve, and liquid supply module.

2. The anion exchange membrane water electrolysis system of claim 1, wherein, The liquid supply module includes a replenishing alkali solution storage tank and a pure water storage tank. The replenishing alkali solution storage tank is connected to the anode alkali solution storage tank through an alkali solution replenishment pipeline; the pure water storage tank is connected to the cathode alkali solution storage tank through a pure water replenishment pipeline. An alkali replenishment branch and a pure water replenishment branch are provided between the alkali replenishment pipeline and the pure water replenishment pipeline; the alkali replenishment branch and the pure water replenishment branch are both connected to the alkali replenishment pipeline and the pure water replenishment pipeline; Both the alkali replenishment branch and the pure water replenishment branch are equipped with branch valves. An alkali replenishment valve is located on the side of the alkali replenishment branch near the anode alkali storage tank on the alkali replenishment pipeline, and a pure water replenishment valve is located on the side of the pure water replenishment branch near the cathode alkali storage tank on the pure water replenishment pipeline. The computer control system is electrically connected to the branch valve, the alkali replenishment valve, and the pure water replenishment valve.

3. The anion exchange membrane water electrolysis system of claim 2, wherein, The anode alkali storage tank is connected to the buffer alkali storage tank via a third circulation pipeline, and the cathode alkali storage tank is connected to the buffer alkali storage tank via a fourth circulation pipeline; the third circulation pipeline is equipped with a third circulation valve, and the fourth circulation pipeline is equipped with a fourth circulation valve; both the third circulation valve and the fourth circulation valve are connected to the computer control system.

4. The anion exchange membrane water electrolysis system of claim 3, wherein, A first circulation pump is provided on the first circulation pipeline, a second circulation pump is provided on the second circulation pipeline, a third circulation pump is provided on the third circulation pipeline, and a fourth circulation pump is provided on the fourth circulation pipeline; an anode inlet pump is provided on the anode inlet pipeline, and a cathode inlet pump is provided on the cathode inlet pipeline; an alkali replenishment pump is provided on the alkali replenishment pipeline, and a pure water replenishment pump is provided on the pure water replenishment pipeline; The first circulation pump, the second circulation pump, the third circulation pump, the fourth circulation pump, the anode inlet pump, the cathode inlet pump, the alkali replenishment pump, and the pure water replenishment pump are all electrically connected to the computer control system.

5. The water electrolysis system of any one of claims 1 to 4, wherein the anion exchange membrane is a perfluorinated sulfonic acid membrane. It also includes a waste liquid module, which includes a waste liquid storage tank. The buffer alkali storage tank is connected to the waste liquid storage tank through a waste liquid pipeline. The waste liquid pipeline is equipped with a waste liquid valve and a waste liquid pump, both of which are electrically connected to the computer control system.

6. The anion exchange membrane water electrolysis system of claim 5, wherein, The anode gas-liquid separator, cathode gas-liquid separator, anode alkaline solution storage tank, cathode alkaline solution storage tank, buffer alkaline solution storage tank, and waste liquid storage tank are all equipped with concentration detectors, which are electrically connected to the computer control system.

7. The anion exchange membrane water electrolysis system of claim 5, wherein, The anode gas-liquid separator, cathode gas-liquid separator, anode alkali storage tank, cathode alkali storage tank, buffer alkali storage tank, and waste liquid storage tank are all equipped with a liquid level detection component, which is electrically connected to the computer control system.

8. The anion exchange membrane water electrolysis system of claim 7, wherein, The liquid level detection component includes a high-level liquid level detector, a middle-level liquid level detector, and a low-level liquid level detector arranged sequentially from top to bottom.

9. The anion exchange membrane water electrolysis system of claim 8, wherein, The anode gas-liquid separator, cathode gas-liquid separator, anode alkaline solution storage tank, cathode alkaline solution storage tank, buffer alkaline solution storage tank, and waste liquid storage tank are all equipped with alarms, and the high-level liquid level detector and the low-level liquid level detector are both electrically connected to the alarms.

10. The anion exchange membrane water electrolysis system according to claim 5, characterized in that, The anode gas-liquid separator, cathode gas-liquid separator, anode alkali storage tank, cathode alkali storage tank, buffer alkali storage tank, and waste liquid storage tank are all equipped with temperature detectors, which are electrically connected to the computer control system.

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