Cascade regulation and control wastewater hydrogen production system
Through cascade control of wastewater hydrogen production system, self-driven separators and self-capture units are used to separate organic and inorganic components in wastewater and capture pure water, solving the problems of high cost of wastewater hydrogen production and shortage of water resources in the prior art. Achieve efficient and low-cost large-scale electrolysis hydrogen production.
Patent Information
- Application Number
- CN202421237284.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-31
- Publication Date
- 2025-02-18
- Estimated Expiration
- 2034-05-31
AI Technical Summary
The existing wastewater hydrogen production technology is costly and difficult to achieve large-scale development, and the shortage of water resources has a great impact on electrolytic hydrogen production.
A cascaded control wastewater hydrogen production system is designed, and the organic and inorganic components in the wastewater are separated by a self-driven separator, and phase separation is performed using a self-driven liquid, and purified water is captured through a self-capture unit for electrolytic hydrogen production. .
Effective isolation between organic and inorganic substances in wastewater is achieved, and the pure water in the electrolyte is used for electrolysis and hydrogen production is ensured, which reduces the consumption and cost of water resources during the hydrogen production process, and improves the efficiency of hydrogen production and product purity.
Smart Images
Figure CN222499396U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of electrochemistry, and more specifically to a cascade-controlled wastewater hydrogen production system. Background Art
[0002] With the introduction of dual carbon goals and new quality productivity, the development of cutting-edge hydrogen energy technology is imminent. In particular, since my country is currently short of freshwater resources, with the explosive growth of hydrogen energy in the future, water shortages will have a greater impact on electrolytic hydrogen production. my country discharges more than 60 billion tons of wastewater and sewage each year. If wastewater is efficiently utilized for hydrogen production, it will help meet my country's future demand for hydrogen energy. However, most wastewater hydrogen production solutions remain at the electrochemical method, dissolved metal reduction, supercritical water gasification, biophotolysis, photofermentation, dark fermentation, photocatalysis and other methods. Most of these solutions remain in the laboratory stage, or are too expensive to achieve large-scale hydrogen production. Therefore, there is an urgent need to develop efficient, large-scale, low-cost wastewater hydrogen production technology and system equipment. Utility Model Content
[0003] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a cascade-controlled wastewater hydrogen production system.
[0004] The purpose of the utility model is achieved through the following solutions:
[0005] A cascade-controlled wastewater hydrogen production system comprises: a self-driven separator, a wastewater inlet, a self-capture unit, a self-driven liquid upper layer, a self-driven liquid lower layer, an electrolytic cell and a component detector; the self-driven separator is used to separate organic components and inorganic components in wastewater, a wastewater inlet is arranged on the self-driven separator, a self-capture unit is arranged in the self-driven separator, and an electrolyte is arranged in the self-capture unit; the self-driven separator is filled with a self-driven liquid with selective separation; when the wastewater enters the self-driven separator and contacts the self-driven liquid, the self-driven liquid can be used to phase-separate the organic components in the wastewater to the self-driven liquid upper layer, and the inorganic components in the wastewater to the self-driven liquid lower layer; after selective separation in the self-driven separator, the water and inorganic substances in the wastewater enter the self-driven liquid lower layer; the water molecules in the lower layer solution pass through the interface The pressure difference enters the self-capture unit in the self-driven separator and is captured by the electrolyte in the self-capture unit to supplement pure water for electrolytic hydrogen production. As a part of the self-driven separator, the self-capture unit separates the self-driven liquid lower layer from the electrolyte inside it through a waterproof and breathable membrane layer, a reverse osmosis layer or a forward osmosis membrane layer, allowing only pure water molecules to enter the electrolyte through the membrane layer, while blocking inorganic matter from the outside. The electrolyte with pure water is obtained in the self-capture unit, and the concentration of chloride ions and cod in the electrolyte is detected by a component detector. After the electrolyte composition meets the requirements of the electrolyzer, the electrolyte enters the electrolyzer for electrolytic hydrogen production. After the electrolysis reaction occurs in the electrolyzer to produce hydrogen and oxygen, the electrolyte circulates into the self-capture unit again to further absorb and obtain water molecules to obtain sufficient water for electrolytic hydrogen production.
[0006] Furthermore, the self-driving liquid includes a lower layer liquid and an upper layer liquid; the lower layer liquid includes 10-25wt% magnesium sulfate, 10-25wt% sodium sulfate and 15-34wt% sodium citrate; the upper layer liquid includes PEG400 aqueous solution, PEG600 aqueous solution, PEG800 aqueous solution, PEG1000 aqueous solution, PEG1500 aqueous solution, PEG2000 aqueous solution, PEG3000 aqueous solution, PEG4000 aqueous solution, PEG6000 aqueous solution or PEG8000 aqueous solution.
[0007] Further, if the electrolyte in the self-capture unit is an alkaline electrolyte, the electrolyzer matches an alkaline electrolyzer or an AEM electrolyzer; if the electrolyte in the self-capture unit is acidic, the electrolyzer matches a PEM electrolyzer.
[0008] Furthermore, it also includes a liquid level meter, a density meter and a control system. When the concentration of the lower layer of the driving liquid increases, the liquid level of the lower layer of the self-driving liquid decreases. When the liquid level drops to the height controlled by the liquid level meter, or the concentration of the lower layer of the self-driving liquid is higher than the control concentration corresponding to the density meter, the control system is triggered to control the replenishment of wastewater to enter the self-selective drive through the wastewater inlet again, which will again leave organic matter in the wastewater in the upper layer of the self-driving liquid, and the inorganic salts and water in the wastewater enter the lower layer of the self-driving liquid, thereby providing a steady supply of water for electrolytic hydrogen production.
[0009] Furthermore, it can also include a hydrogen separator and a hydrogen purifier. The hydrogen generated by electrolysis passes through the hydrogen separator and the hydrogen purifier, and the oxygen passes through the oxygen separator and oxygen purification to obtain the final product.
[0010] Furthermore, by using the waste heat generated by electrolysis as a heat source to heat the self-driving liquid, the phase separation effect and the wastewater self-selective separation effect are enhanced, and at the same time, the water in the lower layer of the self-driving liquid is accelerated to enter the electrolyte through heating.
[0011] Furthermore, it also includes a power supply module for supplying power to the electrolytic cell.
[0012] Furthermore, it also includes a stirrer, which is used to stir the lower layer of the self-driving liquid to make the liquid concentration uniform on the one hand, and to allow the solid salt in the lower layer of liquid to enter the solid-liquid separator on the other hand, so as to obtain the solid salt after separation.
[0013] The beneficial effects of the utility model include:
[0014] The utility model has explored a new connection mechanism after creative thinking: the organic matter, inorganic salts and water in the wastewater are automatically separated by self-driven phase separation, and the water molecules are induced to migrate to the electrolyte through the interface pressure difference in the inorganic-rich phase of the self-driven liquid, which is used to supplement pure water for electrolytic hydrogen production. Specifically, it can induce the organic matter, inorganic solution, volatile matter and other components in the wastewater to separate into phases, and at the same time, it can enable pure water molecules to enter the electrolyte through the interface pressure difference.
[0015] Through the cascade control method of the utility model, organic and inorganic substances in wastewater can be effectively isolated, thereby ensuring that pure water enters the electrolyte for electrolytic hydrogen production, avoiding the systematic impact of complex components of wastewater on electrolytic hydrogen production.
[0016] The design and construction of the self-driven separator of the utility model can realize the integration of in-situ separation of wastewater and mass transfer of pure water, and because the mass transfer distance of water molecules is limited to the micron level, the mass transfer rate is greatly improved, which is helpful for large-scale electrolytic hydrogen production process.
[0017] The agitator in the self-driven separator is used to cause turbulence in the lower layer of the self-driven liquid, preventing the liquid from causing concentration polarization at the mass transfer interface and preventing the generation of salt crystals that damage the mass transfer structure. Therefore, compared with traditional static mass transfer, the utility model can further achieve more efficient mass transfer.
[0018] In addition, the liquid level meter, density meter and component detector provided in the utility model are provided according to the scheme proposed in the utility model, which can effectively control the system process, realize an efficient and stable hydrogen production process, and at the same time achieve the purpose of self-protection and self-regulation of the system.
[0019] The utility model has good stability and high efficiency. By using self-driving liquid and cascade regulation, the organic matter in the wastewater is phase-separated to the upper layer of the self-driving liquid, and the inorganic matter in the wastewater is phase-separated to the lower layer. At the same time, the water molecules in the lower solution migrate to the electrolyte in the self-capture unit, which can completely isolate the organic and inorganic matter in the wastewater from the outside to avoid their influence on the electrolyte, thereby obtaining high-purity hydrogen without any corrosion and toxicity to the electrolysis system.
[0020] The utility model system replenishes water for the electrolyte in the self-capture unit in the self-driven separator for use in electrolysis; at the same time, electrolysis synchronously consumes water to continuously maintain the interface pressure difference between the electrolyte and the lower layer of the self-driven liquid, thereby continuing to induce water to enter the electrolyte from the lower layer of the self-driven liquid, and at the same time providing a solution concentration environment for further wastewater self-selective separation. The realization of this cascade control process enables the system to continuously use industrial wastewater for hydrogen production.
[0021] The utility model system can realize a dynamic and continuous process of hydrogen production using any type of industrial wastewater without distinction, and has no restrictions on wastewater components, concentration, etc.; in addition, the system can provide a way of energy utilization of industrial wastewater, turning a large amount of industrial wastewater into treasure, and realizing the development of new clean energy while reducing environmental pollution.
[0022] Traditional wastewater treatment is difficult to achieve complete water extraction, the high-concentration wastewater obtained is still difficult to treat or becomes hazardous waste, and the water utilization rate is low. The system equipment proposed in the utility model can achieve complete utilization of water resources in wastewater and achieve efficient utilization of wastewater.
[0023] The system provided by the utility model is helpful to realize hydrogen production by electrolysis without extra energy consumption, and realize the dual-effect utilization of wastewater as a resource and energy. In particular, the design and construction of the self-driven separator can realize the integration of wastewater in-situ separation and pure water mass transfer, and because the mass transfer distance of water molecules is limited to the micron level, the mass transfer rate is greatly improved, which is helpful for large-scale electrolysis hydrogen production process. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] 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.
[0025] Figure 1 It is a schematic diagram of the structure of an embodiment of the utility model;
[0026] Figure 2 Data test results of Case 1 for verification of the technical effect of this utility model;
[0027] In the figure, 1-self-driven separator; 2-wastewater inlet; 3-self-capture unit; 4-self-driven liquid upper layer; 5-self-driven liquid lower layer; 6-electrolyzer; 7-power supply module; 8-hydrogen separation; 9-oxygen separator; 10-hydrogen purifier; 11-agitator; 12-liquid level meter; 13-density meter; 14-component detector; 15-solid-liquid separator; 16-solid salt. DETAILED DESCRIPTION
[0028] All features disclosed in all embodiments in this specification, or all features implicitly disclosed, except mutually exclusive features and / or steps, can be combined and / or expanded or replaced in any manner.
[0029] The specific implementation process of the utility model is as follows:
[0030] The embodiment of the utility model provides a cascade-controlled wastewater hydrogen production system, comprising: a self-driven separator 1, a wastewater inlet 2, a self-capture unit 3, a self-driven liquid upper layer 4, a self-driven liquid lower layer 5, an electrolyzer 6, a power supply module 7, hydrogen separation 8, oxygen separation 9, hydrogen purification 10, an agitator 11, a liquid level meter 12, a density meter 13, a component detector 14, a solid-liquid separator 15 and a solid salt 16.
[0031] Specifically, the self-driven separator 1 is a device for separating organic components and inorganic components in wastewater. The device is filled with a self-driven liquid with selective separation. When the wastewater enters the self-driven separator 1 and contacts the self-driven liquid, the organic components in the wastewater can be automatically separated into the self-driven liquid upper layer 4, and the inorganic components in the wastewater can be separated into the self-driven liquid lower layer 5. The self-driven liquid can be a composition of a lower layer liquid (10-25wt% magnesium sulfate, 10-25wt% sodium sulfate or 15-34wt% sodium citrate) and an upper layer liquid (PEG400 aqueous solution, PEG600 aqueous solution, PEG800 aqueous solution, PEG1000 aqueous solution, PEG1500 aqueous solution, PEG2000 aqueous solution, PEG3000 aqueous solution, PEG4000 aqueous solution, PEG6000 aqueous solution or PEG8000 aqueous solution).
[0032] After selective separation in the self-driven separator 1, the water and inorganic substances in the wastewater enter the self-driven liquid lower layer 5. The water molecules in the lower solution enter the self-capture unit 3 in the self-driven separator 1 through the interface pressure difference, and are captured by the electrolyte in the self-capture unit 3 to supplement pure water for electrolytic hydrogen production. As a part of the self-driven separator 1, the self-capture unit 3 separates the self-driven liquid lower layer from the electrolyte inside it through a waterproof and breathable membrane layer, a reverse osmosis layer or a forward osmosis membrane layer, allowing only pure water molecules to enter the electrolyte through the membrane layer, while blocking inorganic substances from the outside.
[0033] The electrolyte with pure water is obtained in the self-capture unit 3. After the concentration of chloride ions and cod in the electrolyte is detected by the component detector 14, after reaching the requirements of the electrolytic cell, the electrolyte enters the electrolytic cell 6 for electrolytic hydrogen production. If the electrolyte is an alkaline electrolyte, the electrolytic cell 6 can be matched with an alkaline electrolytic cell or an AEM electrolytic cell; if the electrolyte is acidic, the electrolytic cell 6 can be matched with a PEM electrolytic cell. After the electrolysis reaction occurs in the electrolytic cell 6 to produce hydrogen and oxygen, the electrolyte is circulated again into the self-capture unit 3 to further absorb and obtain water molecules to obtain sufficient water for electrolytic hydrogen production.
[0034] After the water in the lower layer 5 of the self-driving liquid migrates to the electrolyte, the concentration of the lower layer 5 of the self-driving liquid increases, and the liquid level of the lower layer 5 of the self-driving liquid decreases. The lower layer 5 of the self-driving liquid is turbulently stirred by the agitator 11 to prevent concentration polarization from occurring at the mass transfer interface. When the liquid level drops to the height controlled by the liquid level gauge 12, or the concentration of the lower layer of the self-driving liquid is higher than the control concentration corresponding to the density gauge 13, the trigger system automatically replenishes the wastewater and enters the self-selective driver 1 again through the wastewater inlet 2, which will again leave the organic matter in the wastewater in the upper layer 4 of the self-driving liquid, and the inorganic salts and water in the wastewater enter the lower layer 5, thereby providing a continuous supply of water for hydrogen production by electrolysis.
[0035] In addition, as the concentration of the lower layer 5 of the self-driving liquid continues to increase, salt precipitation occurs, and the salt mud enters the solid-liquid separator 15, where solid salt is obtained after separation.
[0036] The hydrogen produced by electrolysis passes through a hydrogen separator 8 and a hydrogen purifier 9, and the oxygen passes through an oxygen separator 9 and oxygen purification to obtain the final product.
[0037] Through this cascade control method, the organic and inorganic matter in the wastewater can be effectively isolated, thereby ensuring that pure water enters the electrolyte for electrolytic hydrogen production, avoiding the systematic impact of the complex components of the wastewater on electrolytic hydrogen production.
[0038] During the whole process, the waste heat generated by electrolysis can also be used as a heat source to heat the self-driving liquid to enhance the phase separation effect and the self-selective separation effect of wastewater. At the same time, heating can be used to accelerate the entry of water in the lower layer of the self-driving liquid into the electrolyte.
[0039] The system will realize the process of hydrogen production by electrolysis of industrial wastewater. Compared with the existing wastewater treatment process, it can achieve low-cost wastewater treatment while realizing the production of hydrogen energy.
[0040] The utility model has the following advantages:
[0041] Since the self-driven separator in the utility model adds impurity-free water to the electrolyte, the bottleneck of direct industrial wastewater hydrogen production is broken through the restriction of industrial wastewater composition due to different wastewater sources. In addition, the utility model can effectively prevent the oxidation and escape of harmful and toxic components in industrial wastewater, and is a green, non-toxic and environmentally friendly process system. The electrolytic hydrogen production system does not contain impurity ions such as calcium ions and magnesium ions, and there will be no calcium and magnesium precipitation during long-term operation, reducing the cost of later cleaning and maintenance.
[0042] The utility model device can realize hydrogen and oxygen separation when multiple groups of electrolysis units are used in series and parallel, and high-purity hydrogen and oxygen can be well collected.
[0043] The utility model can realize the internal self-circulation of electrolyte, and there is no need to additionally supplement electrolyte and pure water therein.
[0044] Case 1 of technical effect verification of this utility model:
[0045] A self-selective phase separation liquid is formed by using 25% MgSO4 and 30wt% PEG8000 as a ratio, and chemical wastewater is used as a water source. The wastewater mainly contains inorganic salts such as sodium chloride, naphthol, 2-naphthoxyacetic acid, 1-naphthyl butyrate, 2-naphthyl acetate and other organic substances. The KOH electrolyte has a concentration of 45wt%, and the electrolytic cell operates at 60°C for more than 100 hours without side reactions and catalyst corrosion. After the reaction, the proportion of each impurity component in the KOH electrolyte is less than 0.1wt%, such as Figure 2 shown.
[0046] 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.
[0047] Example 1
[0048] A cascade-controlled wastewater hydrogen production system comprises: a self-driven separator 1, a wastewater inlet 2, a self-capture unit 3, a self-driving liquid upper layer 4, a self-driving liquid lower layer 5, an electrolytic cell 6 and a component detector 14; the self-driven separator 1 is used to separate organic components and inorganic components in wastewater, a wastewater inlet 2 is arranged on the self-driven separator 1, a self-capture unit 3 is arranged in the self-driven separator 1, and an electrolyte is arranged in the self-capture unit 3; the self-driven separator 1 is filled with a self-driving liquid with selective separation; when the wastewater enters the self-driven separator 1 and contacts the self-driving liquid, the self-driving liquid can be used to phase-separate the organic components in the wastewater to the self-driving liquid upper layer 4, and the inorganic components in the wastewater to the self-driving liquid lower layer 5; after selective separation in the self-driven separator 1, the water and inorganic substances in the wastewater enter the self-driving liquid lower layer 5; the water in the lower solution The water molecules enter the self-capture unit 3 in the self-driven separator 1 through the interface pressure difference, and are captured by the electrolyte in the self-capture unit 3 to supplement pure water for electrolytic hydrogen production. As a part of the self-driven separator 1, the self-capture unit 3 separates the self-driven liquid lower layer from the electrolyte inside it through a waterproof and breathable membrane layer, a reverse osmosis layer or a forward osmosis membrane layer, and only allows pure water molecules to enter the electrolyte through the membrane layer, while inorganic matter is blocked out. The electrolyte with pure water is obtained in the self-capture unit 3, and the concentration of chloride ions and cod in the electrolyte is detected by the component detector 14. After the electrolyte composition meets the requirements of the electrolytic cell, the electrolyte enters the electrolytic cell 6 for electrolytic hydrogen production. After the electrolysis reaction occurs in the electrolytic cell 6 to produce hydrogen and oxygen, the electrolyte circulates into the self-capture unit 3 again to further absorb and obtain water molecules to obtain sufficient water for electrolytic hydrogen production.
[0049] Example 2
[0050] Based on Example 1, the self-driving liquid includes a lower layer liquid and an upper layer liquid; the lower layer liquid includes 10-25wt% magnesium sulfate, 10-25wt% sodium sulfate and 15-34wt% sodium citrate; the upper layer liquid includes PEG400 aqueous solution, PEG600 aqueous solution, PEG800 aqueous solution, PEG1000 aqueous solution, PEG1500 aqueous solution, PEG2000 aqueous solution, PEG3000 aqueous solution, PEG4000 aqueous solution, PEG6000 aqueous solution or PEG8000 aqueous solution.
[0051] Example 3
[0052] On the basis of Example 1, if the electrolyte in the self-capture unit 3 is an alkaline electrolyte, the electrolytic cell 6 matches an alkaline electrolytic cell or an AEM electrolytic cell; if the electrolyte in the self-capture unit 3 is acidic, the electrolytic cell 6 matches a PEM electrolytic cell.
[0053] Example 4
[0054] On the basis of Example 1, it also includes a liquid level meter 12, a density meter 13 and a control system. The concentration of the driving liquid lower layer 5 increases, and the liquid level of the self-driving liquid lower layer 5 decreases. When the liquid level drops to the control height of the liquid level meter 12, or the concentration of the self-driving liquid lower layer is higher than the control concentration corresponding to the density meter 13, the control system is triggered to control the replenishment of wastewater to enter the self-selective driver 1 through the wastewater inlet 2 again, and the organic matter in the wastewater will be retained in the self-driving liquid upper layer 4 again, and the inorganic salts and water in the wastewater enter the self-driving liquid lower layer 5, thereby providing a continuous supply of water for electrolytic hydrogen production.
[0055] Example 5
[0056] On the basis of Example 1, a hydrogen separator 8 and a hydrogen purifier 10 may also be included. The hydrogen generated by electrolysis passes through the hydrogen separator 8 and the hydrogen purifier 10, and the oxygen passes through the oxygen separator 9 and oxygen purification to obtain the final product.
[0057] Example 6
[0058] On the basis of Example 1, the waste heat generated by electrolysis is used as a heat source to heat the self-driving liquid to enhance the phase separation effect and the self-selective separation effect of wastewater. At the same time, heating is used to accelerate the entry of water in the lower layer of the self-driving liquid into the electrolyte.
[0059] Example 7
[0060] On the basis of embodiment 1, it further includes a power supply module 7 for supplying power to the electrolytic cell 6 .
[0061] Example 8
[0062] On the basis of Example 1, an agitator 11 is further included, which is used to stir the lower layer 5 of the self-driving liquid to make the liquid concentration uniform on the one hand, and to allow the solid salt in the lower layer of liquid to enter the solid-liquid separator 15 on the other hand, so as to obtain solid salt 16 after separation.
[0063] The specific implementation methods of the present utility model are not limited to the above-mentioned methods. The above description is only the preferred embodiment of the present utility model and the technical principles used. Those skilled in the art will understand that the present utility model is not limited to the specific embodiments described here. It is possible for those skilled in the art to make various obvious changes, adjustments and substitutions without departing from the scope of protection of the present utility model. Therefore, although the present utility model is described in more detail through the above embodiments, the present utility model is not limited to the above embodiments, but may also include more other equivalent embodiments without departing from the principles and concepts of the present utility model, and the scope of the present utility model is determined by the scope of the attached claims.
Claims
1. A cascade control wastewater hydrogen production system, characterized in that: include: A self-driven separator (1), a wastewater inlet (2), a self-capture unit (3), a self-driven liquid upper layer (4), a self-driven liquid lower layer (5), an electrolytic cell (6) and a component detector (14); The self-driven separator (1) is used to separate organic components and inorganic components in wastewater. A wastewater inlet (2) is provided on the self-driven separator (1), a self-capture unit (3) is provided in the self-driven separator (1), and an electrolyte is provided in the self-capture unit (3). The self-driven separator (1) is filled with a self-driving liquid with selective separation. When the wastewater enters the self-driven separator (1) and contacts the self-driving liquid, the self-driving liquid can be used to separate the organic components in the wastewater into an upper layer (4) of the self-driving liquid, and the inorganic components in the wastewater into a lower layer (5) of the self-driving liquid. After selective separation in the self-driven separator (1), the water and inorganic substances in the wastewater enter the self-driven liquid lower layer (5); the water molecules in the lower solution enter the self-capture unit (3) in the self-driven separator (1) through the interface pressure difference, and are captured by the electrolyte in the self-capture unit (3) to supplement pure water for electrolytic hydrogen production; the self-capture unit (3) is a part of the self-driven separator (1), which separates the self-driven liquid lower layer from the electrolyte inside it through a waterproof and breathable membrane layer, a reverse osmosis layer or a forward osmosis membrane layer, allowing only pure water molecules to pass through the membrane layer to enter the electrolyte, while blocking inorganic substances from the outside; An electrolyte containing pure water is obtained in the self-capture unit (3). The concentrations of chloride ions and cod in the electrolyte are detected by a component detector (14). After the electrolyte composition reaches the requirements of the electrolytic cell, the electrolyte enters the electrolytic cell (6) for electrolytic hydrogen production. After an electrolytic reaction occurs in the electrolytic cell (6) to produce hydrogen and oxygen, the electrolyte is circulated again into the self-capture unit (3) to further absorb and obtain water molecules, thereby obtaining sufficient water for electrolytic hydrogen production.
2. The cascade control wastewater hydrogen production system according to claim 1, characterized in that: The self-driving liquid includes a lower layer liquid and an upper layer liquid; the lower layer liquid includes 10-25wt% magnesium sulfate, 10-25wt% sodium sulfate and 15-34wt% sodium citrate; the upper layer liquid includes PEG400 aqueous solution, PEG600 aqueous solution, PEG800 aqueous solution, PEG1000 aqueous solution, PEG1500 aqueous solution, PEG2000 aqueous solution, PEG3000 aqueous solution, PEG4000 aqueous solution, PEG6000 aqueous solution or PEG8000 aqueous solution.
3. The cascade control wastewater hydrogen production system according to claim 1, characterized in that: If the electrolyte in the self-capture unit (3) is an alkaline electrolyte, the electrolytic cell (6) matches an alkaline electrolytic cell or an AEM electrolytic cell; if the electrolyte in the self-capture unit (3) is acidic, the electrolytic cell (6) matches a PEM electrolytic cell.
4. The cascade control wastewater hydrogen production system according to claim 1, characterized in that: The invention also comprises a liquid level meter (12), a density meter (13) and a control system. When the concentration of the lower layer of the driving liquid (5) increases, the liquid level of the lower layer of the self-driving liquid (5) decreases. When the liquid level drops to the height controlled by the liquid level meter (12), or when the concentration of the lower layer of the self-driving liquid is higher than the corresponding control concentration of the density meter (13), the control system is triggered to control the replenished wastewater to enter the self-driving separator (1) again through the wastewater inlet (2). The organic matter in the wastewater will be retained in the upper layer of the self-driving liquid (4), and the inorganic salts and water in the wastewater will enter the lower layer of the self-driving liquid (5), thereby providing a continuous supply of water for electrolytic hydrogen production.
5. The cascade control wastewater hydrogen production system according to claim 1, characterized in that: It can also include a hydrogen separator (8) and a hydrogen purifier (10). The hydrogen generated by electrolysis passes through the hydrogen separator (8) and the hydrogen purifier (10), and the oxygen passes through the oxygen separator (9) and oxygen purification to obtain the final product.
6. The cascade control wastewater hydrogen production system according to claim 1, characterized in that: By using the waste heat generated by electrolysis as a heat source to heat the self-driving liquid, the phase separation effect and the self-selective separation effect of wastewater are enhanced, and at the same time, heating is used to accelerate the entry of water in the lower layer of the self-driving liquid into the electrolyte.
7. The cascade control wastewater hydrogen production system according to claim 1, characterized in that: It also includes a power supply module (7) for supplying power to the electrolytic cell (6).
8. The cascade control wastewater hydrogen production system according to claim 1, characterized in that: The invention also comprises a stirrer (11), which is used to stir the lower layer of the self-driving liquid (5) to make the liquid concentration uniform, and to allow the solid salt in the lower layer of the liquid to enter the solid-liquid separator (15) for separation to obtain the solid salt (16).