Mine water hydrogen production system and method

Abstract

The invention relates to the field of mine water resource utilization, in particular to a mine water hydrogen production system and method. The system comprises a mine water feeding pipeline, a fresh steam feeding pipeline, a preheating unit, an evaporation unit, a water storage unit, a phase change mass transfer unit, an electrolysis unit and a salt recovery unit, the preheating unit comprises preheaters A1-An which are sequentially connected in series, and the evaporation unit comprises evaporators B1-Bn which are sequentially connected in series. The system for producing hydrogen from mine water can greatly reduce the content of impurity ions in mine water, reduce the scaling phenomenon of the device, and ensure the long-period operation of evaporation equipment and mass transfer devices.

Description

Technical Field

[0001] This invention relates to the field of mine water resource utilization, specifically to a mine water hydrogen production system and method. Background Technology

[0002] Coal, as a fundamental energy source, plays a vital role in the national economy. The large amounts of mine water generated and discharged during coal mining represent a significant unconventional water resource. According to statistics, in 2022, the coal production in the nine provinces along the Yellow River reached 3.59 billion tons, with mine water inflows of approximately 6.5 billion cubic meters, approaching the designed water diversion volume of 8 billion cubic meters for the first phase of the South-to-North Water Diversion Project. If this mine water is not effectively treated and utilized, it will not only waste precious water resources and pollute the ecological environment of the Yellow River basin, but also trigger mine flooding accidents, posing serious production safety risks. In the context of dual carbon emissions, coal chemical enterprises face high carbon emissions, making the use of green hydrogen an important means to reduce these emissions. Green hydrogen production inevitably requires water. In regions with relatively scarce water resources, utilizing mine water—an unconventional water resource—for green hydrogen production has greater practical significance compared to using conventional water resources for hydrogen production.

[0003] Currently, the most common method for treating highly mineralized mine water is reverse osmosis membrane technology. While this process effectively filters out most ions, it also leaves behind highly mineralized concentrated brine. This type of wastewater has extremely high salt content, causing soil salinization and groundwater pollution, and also results in significant membrane wear. Since the main components of highly mineralized concentrated brine from coal mines are sodium chloride and sodium sulfate, evaporation and crystallization can be used to recover the salts and simultaneously obtain fresh water for green hydrogen production. This can improve the energy utilization rate of mine water and is of great significance for promoting carbon emission reduction in the coal chemical industry. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems of low membrane mass transfer efficiency and easy clogging in existing mine water hydrogen production processes, and to provide a mine water hydrogen production system and method. This system can realize the separation and purification of salt in mine water, reduce the impact of impurity ions on the electrolysis process, improve the efficiency of hydrogen production, and ensure the continuous industrial treatment of mine water.

[0005] To achieve the above objectives, the present invention provides a system for producing hydrogen from mine water, comprising: a mine water feed pipeline, a fresh steam feed pipeline, a preheating unit, an evaporation unit, a compression unit, a water storage unit, a phase change mass transfer unit, an electrolysis unit, and a salt recovery unit; wherein... The preheating unit includes preheaters A1~A1 connected in series. n The inlet of the preheater A1 is connected to the mine water feed pipeline; The evaporation unit includes evaporators B1~B1 connected in series.n The evaporators B1~B n Each of the evaporators is equipped with a reboiler; the evaporator B n The upper part of the preheater A n The outlet connection; the evaporator B n The inlet of the reboiler is connected to the outlet of the compression unit; the evaporator B n The top of the evaporator B n-1 The reboiler inlet is connected inside, and the bottom is connected to the evaporator B. n-1 The upper part is connected, and so on, until the top of the evaporator B1 is connected to the inlet of the compression unit and the bottom is connected to the salt recovery unit; any of the evaporators B m The outlet of the reboiler inside is connected to the preheater A with the corresponding number. m connect; The outlet of the compression unit is connected to the fresh steam feed line; The water storage unit is connected to the preheaters A1~A1 respectively. n connect; The phase change mass transfer unit includes a first heat exchanger and a mass transfer device, and the water storage unit, the first heat exchanger and the mass transfer device form a circulation loop. The electrolysis unit includes an electrolytic cell and an energy supply unit connected in series, and the electrolytic cell, the first heat exchanger and the mass transfer device form a circulation loop; n is an integer greater than or equal to 1, and m is an integer from 1 to n.

[0006] Preferably, the system further includes a pretreatment unit, which is connected to the mine water inlet pipeline and the inlet of the preheater A1, respectively.

[0007] Preferably, the preheaters A1~A n It is equipped with an ultrasonic transmitter.

[0008] Preferably, the evaporators B1~B n It is equipped with an ultrasonic transmitter.

[0009] Preferably, the compression unit includes at least one compressor.

[0010] Preferably, the mass transfer device includes a purified water chamber, an electrolyte chamber, and an FO membrane. The FO membrane is disposed between the purified water chamber and the electrolyte chamber. The water storage unit, the first heat exchanger, and the purified water chamber form a circulation loop. The electrolytic cell, the first heat exchanger, and the electrolyte chamber form a circulation loop.

[0011] Preferably, the salt recovery unit includes a second heat exchanger and a centrifuge. The bottom of the evaporator B1 is sequentially connected to the second heat exchanger and the centrifuge. The second heat exchanger is connected to the mine water inlet pipeline and the preheater A1, respectively.

[0012] Preferably, the electrolytic cell is equipped with a hydrogen recovery device and an oxygen recovery device.

[0013] Preferably, the hydrogen recovery device includes a hydrogen gas-liquid separator and a hydrogen purification device, wherein the hydrogen purification device includes a membrane separator and / or an adsorption tower; and the oxygen recovery device includes an oxygen gas-liquid separator.

[0014] Another aspect of the present invention provides a method for producing hydrogen from mine water, the method being carried out in the aforementioned system and comprising the following steps: 1) At least a portion of the mine water pretreated by the pretreatment unit is sequentially fed into preheaters A1~A n After heat exchange, it is sent to evaporator B. n ; 2) Evaporator B n Inside, the gas phase generated by the reboiler heating of mine water is sent to evaporator B. n-1 The reboiler inside is connected in sequence with evaporator B. n-1 Preheater A n-1 After heat exchange, the mine water is sent to the water storage unit, and the remaining liquid phase is sent to evaporator B. n-1 The process continues in sequence until the gas phase in evaporator B1 is sent to the compression unit and the remaining liquid phase is sent to the salt recovery unit. 3) The vapor phase from evaporator B1 is pressurized by the compression unit and mixed with fresh steam before being sent to evaporator B. n The reboiler inside is connected in sequence with evaporator B. n Preheater A n The mine water is heated and then sent to the water storage unit. 4) Mine water from the water storage unit enters the mass transfer device after heat exchange in the first heat exchanger. The electrolyte concentrated by ionization in the electrolytic cell is replenished with water in the mass transfer device after heat exchange in the first heat exchanger, and then returned to the electrolytic cell. The remaining mine water is returned to the water storage unit.

[0015] Preferably, the pretreatment includes: softening, clarifying and filtering the mine water in sequence.

[0016] Preferably, a portion of the pretreated mine water is sent to the preheater A1, and the other portion is sent to the second heat exchanger, where it exchanges heat with the liquid phase from the evaporator B1 before being sent to the preheater A1.

[0017] Preferably, the mine water from the water storage unit is sent to the clean water chamber after heat exchange in the first heat exchanger, the electrolyte concentrated by ionization in the electrolytic cell is sent to the electrolyte chamber after heat exchange in the first heat exchanger, the mine water enters the electrolyte chamber from the clean water chamber through the FO membrane to replenish the electrolyte water, and the liquid phase from the evaporator B1 is sent to the centrifuge after heat exchange in the second heat exchanger.

[0018] Preferably, the mine water feed pressure is 0.2~3 MPaG, and the mine water is sequentially fed into the preheaters A1~A1. n The temperature after heat exchange is 90~250℃; Preferably, after being pressurized by the compression unit, the temperature of the steam is 150~300℃ and the pressure is 1~3MPaG.

[0019] Preferably, the temperature of the water storage unit is 25~60℃.

[0020] Compared with the prior art, this application has the following advantages: 1) The mine water hydrogen production system of the present invention can realize the separation of salt and purification of mine water, make full use of mine water resources, and provide an industrial continuous treatment solution for the development of green hydrogen coupled coal chemical process and the reduction of carbon dioxide emissions from coal chemical industry in water-scarce areas.

[0021] 2) The mine water hydrogen production system of this invention couples multi-effect mechanical vapor compression technology with ultrasonic enhancement technology, significantly reducing the content of impurity ions in the mine water, minimizing scaling in the evaporator and heat exchanger, and ensuring long-term operation of the evaporation equipment and mass transfer devices. Simultaneously, due to the reduced impurity ion content in the purified mine water, the mass transfer flux of the FO membrane is not affected by impurity components, further extending the service life of the FO membrane in the phase change mass transfer device and ensuring the stable and efficient operation of the water electrolysis hydrogen production process.

[0022] 3) This invention uses an FO membrane to isolate impurity ions in mine water, reducing the impact of impurity ions on the electrolysis process. At the same time, compared with other technologies such as PTFE membranes, the FO membrane can quickly replenish the water required for the hydrogen production process, thereby improving the efficiency of hydrogen production.

[0023] 4) The mine water hydrogen production system of this invention has a wide range of applications and can treat mine water containing mainly calcium ions, chloride ions, sodium ions, magnesium ions, sulfate ions, etc., with chloride ion content less than or equal to 10,000 mg / L, calcium ion content less than or equal to 10,000 mg / L, magnesium ion content less than or equal to 1,000 mg / L, sodium ion content less than or equal to 10,000 mg / L, and sulfate ion content less than or equal to 3,000 mg / L. After purification by the mine water hydrogen production system of this invention, the mine water has chloride ion content less than or equal to 1,000 mg / L, calcium ion content less than or equal to 1,000 mg / L, magnesium ion content less than or equal to 200 mg / L, sodium ion content less than or equal to 1,000 mg / L, and sulfate ion content less than or equal to 500 mg / L, effectively extending the service life of the FO membrane and improving the water replenishment rate. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the mine water hydrogen production system in Embodiment 1 of the present invention.

[0025] Figure 2 This is a schematic diagram of the mine water hydrogen production system in Embodiment 2 of the present invention.

[0026] Figure 3 This is a schematic diagram of the mine water hydrogen production system in Embodiment 3 of the present invention.

[0027] Explanation of reference numerals in the attached figures 1. Mine water feed line; 2. Clarification unit; 3. Filtration unit; 4. Heat exchanger A1; 5. Heat exchanger A2; 6. Heat exchanger A3; 7. Evaporator B3; 8. Evaporator B2; 9. Evaporator B1; 10. Second heat exchanger; 11. Compressor; 12. Fresh steam feed line; 13. Water storage tank; 14. First heat exchanger; 15. Mass transfer device; 16. Electrolyzer; 17. Oxygen recovery device; 18. Hydrogen recovery device; 19. Centrifuge; 20. Mixed salts; 21. Photovoltaic cell; 22. Reboiler C3; 23. Reboiler C2; 24. Reboiler C1. Detailed Implementation

[0028] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0029] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0030] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. The term "comprising" and any variations thereof mean non-exclusive inclusion, where one or more other features, integers, steps, operations, units, components, and / or combinations thereof may be present or added.

[0031] In addition, terms such as “center,” “horizontal,” “up,” “down,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer” that indicate orientation or positional relationship are based on the orientation or relative positional relationship shown in the accompanying drawings. They are only for the purpose of simplifying the description of this application and do not indicate that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0032] Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0033] The mine water hydrogen production system of the present invention includes: a mine water inlet pipeline 1, a fresh steam inlet pipeline 12, a preheating unit, an evaporation unit, a compression unit, a water storage unit, a phase change mass transfer unit, an electrolysis unit, and a salt recovery unit; wherein, The preheating unit includes preheaters A1~A1 connected in series. n The inlet of the preheater A14 is connected to the mine water feed pipeline 1; The evaporation unit includes evaporators B1~B1 connected in series. n The evaporators B1~B n Each of the evaporators is equipped with a reboiler; the evaporator B n The upper part of the preheater An The outlet connection; the evaporator B n The inlet of the reboiler is connected to the outlet of the compression unit; the evaporator B n The top of the evaporator B n-1 The reboiler inlet is connected inside, and the bottom is connected to the evaporator B. n-1 The upper part is connected, and so on, until the top of the evaporator B1 is connected to the inlet of the compression unit and the bottom is connected to the salt recovery unit; any of the evaporators B m The outlet of the reboiler inside is connected to the preheater A with the corresponding number. m connect; The outlet of the compression unit is connected to the fresh steam feed line; The water storage unit is connected to the preheaters A1~A1 respectively. n connect; The phase change mass transfer unit includes a first heat exchanger 14 and a mass transfer device 15, and the water storage unit, the first heat exchanger 14 and the mass transfer device 15 form a circulation loop. The electrolysis unit includes an electrolytic cell 16 connected in series and an energy supply unit. The electrolytic cell 16, the first heat exchanger 14 and the mass transfer device 15 form a circulation loop. n is an integer greater than or equal to 1, and m is an integer from 1 to n.

[0034] In this invention, the value of m is any integer from 1 to n. For example, when n is 1, m is 1, and the outlet of the reboiler in evaporator B1 is connected to preheater A1. When n is 2, m takes values ​​of 1 and 2 successively, and the outlet of the reboiler in evaporator B1 is connected to preheater A1, and the outlet of the reboiler in evaporator B2 is connected to preheater A2. When n is 3, m takes values ​​of 1, 2, and 3 successively, and the outlet of the reboiler in evaporator B1 is connected to preheater A1, the outlet of the reboiler in evaporator B2 is connected to preheater A2, and the outlet of the reboiler in evaporator B3 is connected to preheater A3.

[0035] The system of the present invention further includes a pretreatment unit for pretreatment of mine water, wherein the pretreatment unit is connected to the mine water inlet pipeline 1 and the inlet of the preheater A14.

[0036] The mine water hydrogen production system of the present invention can adjust the number of preheaters in the preheating unit and the number of evaporators in the evaporation unit according to factors such as the amount of mine water to be processed and the salinity of the mine water. n can be any integer greater than or equal to 1.

[0037] In some embodiments, when n=1, the preheating unit includes a preheater A14, the evaporation unit includes an evaporator B19, and a reboiler C124 is installed inside the evaporator B19. The mine water inlet pipeline 1 is connected in sequence to the upper part of the preheater A14 and the evaporator B19. The top of the evaporator B19 is connected to the inlet of the compression unit, and the bottom is connected to the salt recovery unit. The outlet of the compression unit is connected to the inlet of the reboiler C124 inside the evaporator B19. The outlet of the reboiler C124 is connected to the inlet of the preheater A14, and the outlet of the preheater A14 is connected to the water storage unit.

[0038] When n=2, the preheating unit includes preheaters A1~A2, the evaporation unit includes evaporators B1~B2, and reboilers C1 and C2 are respectively installed in evaporators B1 and B2. The mine water inlet pipeline 1 is connected to preheaters A1 and A2 in sequence. Preheater A25 is connected to the upper part of evaporator B28. The top of evaporator B27 is connected to the inlet of reboiler C124 in evaporator B18, and the bottom is connected to the upper part of evaporator B19. The outlet of reboiler C124 is connected to preheater A14. The top of evaporator B19 is connected to the inlet of the compression unit, and the bottom is connected to the salt recovery unit. The outlet of the compression unit is connected to the inlet of reboiler C223 in evaporator B28, and the outlet of reboiler C223 is connected to preheater A25. Preheaters A1 and A2 are both connected to the water storage unit.

[0039] When n=3, the preheating unit includes preheaters A1~A3, and the evaporation unit includes evaporators B1~B3. Reboilers C1~C3 are respectively installed in evaporators B1~B3. The mine water inlet pipeline 1 is sequentially connected to preheaters A1~A3. Preheater A36 is connected to the upper part of evaporator B37. The top of evaporator B37 is connected to the inlet of reboiler C223 in evaporator B28, and the bottom is connected to the upper part of evaporator B28. The outlet of reboiler C223 is connected to preheater A25. The top of evaporator B28 is connected to the inlet of reboiler C124 in evaporator B19, and the bottom is connected to the upper part of evaporator B28. 1 9 The upper part is connected to the reboiler C124 outlet, which is connected to the preheater A14. The top of the evaporator B19 is connected to the inlet of the compression unit, and the bottom is connected to the salt recovery unit. The outlet of the compression unit is connected to the inlet of the reboiler C322 in the evaporator B37. The outlet of the reboiler C322 is connected to the preheater A36. The preheaters A1 to A3 are all connected to the water storage unit.

[0040] The present invention relates to the preheaters A1~A n There are no special restrictions on the type; any conventional heat exchanger in this field is acceptable. The preheaters A1~A... nPreferably, an ultrasonic transmitter is provided. In some embodiments, preheaters A1~A n It is a tubular heat exchanger, and the mine water inlet pipeline 1 is connected to the tube side of preheater A1. Preheaters A1~A n The tubes are connected in series, preheaters A1~A n The tube side is equipped with an ultrasonic transmitter. The ultrasonic transmitter emits ultrasonic waves that cause ultrasonic cavitation in the mine water within the preheater, increasing the turbulence coefficient and thus improving the heat transfer coefficient and efficiency, enhancing the heat transfer effect. Simultaneously, because the mine water contains a large amount of salt, it passes through preheaters A1~A... n Heating can cause a large amount of scaling inside the heat exchanger. The ultrasonic transmitter has a significant effect on preventing and removing scaling.

[0041] The present invention does not limit the type of evaporators B1 to Bn, and they can be any one of falling film evaporators, rising film evaporators, and forced circulation evaporators. Evaporators B1 to Bn are preferably equipped with ultrasonic transmitters.

[0042] In the system described in this invention, a demister is preferably provided. The top of the evaporator B1 is connected in sequence to the demister and the compression unit to prevent foam generated by secondary steam from being carried into the compression unit.

[0043] The compression unit of this invention includes at least one compressor 11. When the compression unit includes two or more compressors, the compressors can be connected in series. This application does not impose any special restrictions on the type of compressor; any steam compressor conventionally applicable to MVR technology in the art is acceptable. Depending on the evaporation capacity, a centrifugal compressor or a Roots compressor can be selected.

[0044] The water storage unit described in this invention is connected to the preheaters A1~A1 respectively. n The connection is used to store purified mine water, and the water storage unit can be a storage tank or a water tower.

[0045] The phase change mass transfer unit of this invention is used to replenish the water in the electrolyte. The mass transfer device 15 may include a purified water chamber, an electrolyte chamber, and an FO membrane. The FO membrane is disposed between the purified water chamber and the electrolyte chamber. The water storage unit, the first heat exchanger 14, and the purified water chamber form a circulation loop. The electrolytic cell, the first heat exchanger 14, and the electrolyte chamber also form a circulation loop. Mine water from the storage tank enters the purified water chamber after heat exchange with the first heat exchanger 14. High-temperature concentrated electrolyte from the electrolytic cell 16 enters the electrolyte chamber after cooling down by heat exchange with the mine water in the first heat exchanger 14. The purified mine water in the purified water chamber passes through the FO membrane into the concentrated electrolyte in the electrolyte chamber, replenishing the water during the electrolysis process. The diluted electrolyte returns to the electrolytic cell 16. Remaining water in the purified water chamber returns to the water storage unit.

[0046] The electrolyzer 16 described in this invention can be powered by renewable energy sources, such as photovoltaic power generation, or directly by the power grid. This invention does not impose any special restrictions on the type of electrolyzer 16. When using an alkaline electrolyte, the electrolyzer 16 can be configured as an ALK / AWE electrolyzer or an AEM anion exchange membrane electrolyzer.

[0047] The electrolytic cell 16 of this invention may be equipped with a hydrogen recovery device 18 and an oxygen recovery device 17. Preferably, the hydrogen recovery device 18 includes a hydrogen gas-liquid separator and a hydrogen purification device, wherein the hydrogen purification device includes a membrane separator and / or an adsorption tower; the oxygen recovery device includes an oxygen gas-liquid separator. An electrolytic reaction occurs within the electrolytic cell 16, and the generated hydrogen and oxygen enter the hydrogen recovery device 18 and oxygen recovery device 17, respectively. In the hydrogen recovery device 18, the hydrogen, after recovering the entrained electrolyte by the hydrogen gas-liquid separator, enters the purification device, where it is purified to obtain hydrogen product. In the oxygen recovery device 17, the oxygen, after recovering the entrained electrolyte by the oxygen gas-liquid separator, obtains oxygen product.

[0048] The salt recovery unit of this invention may include a second heat exchanger 10 and a centrifuge 19. The bottom of the evaporator B19 is sequentially connected to the second heat exchanger 10 and the centrifuge 19. The second heat exchanger 10 is connected to the mine water inlet pipeline 1 and the preheater A14, respectively. In this invention, the mine water can partially pass through the second heat exchanger 10, exchange heat with the liquid phase from the bottom of the evaporator B19, and then mix with the remaining mine water before entering the preheater A14 to recover part of the heat from the liquid phase at the bottom of the evaporator B19.

[0049] The specific steps for producing hydrogen in the aforementioned mine water hydrogen production system may include: 1) At least a portion of the mine water pretreated by the pretreatment unit is sequentially fed into preheaters A1~A n After heat exchange, it is sent to evaporator B. n ; 2) Evaporator B n Inside, the gas phase generated by the reboiler heating of mine water is sent to evaporator B. n-1 The reboiler inside is connected in sequence with evaporator B. n-1 Preheater A n-1 After heat exchange, the mine water is sent to the water storage unit, and the remaining liquid phase is sent to evaporator B. n-1 Inside, and so on, until the gas phase in evaporator B19 is sent to the compression unit and the remaining liquid phase is sent to the salt recovery unit; 3) The vapor phase from evaporator B19 is mixed with fresh steam and pressurized by the compression unit before being sent to evaporator B. n The reboiler inside is connected in sequence with evaporator B.n Preheater A n The mine water is heated and then sent to the water storage unit. 4) Mine water from the water storage unit enters the mass transfer device 15 after heat exchange in the first heat exchanger 14. The electrolyte concentrated by ionization in the electrolytic cell 16 is replenished with water in the mass transfer device 15 after heat exchange in the first heat exchanger 14, and then returns to the electrolytic cell 16. The remaining mine water returns to the water storage unit.

[0050] In this invention, before preheating the mine water, it is preferable to pretreat the mine water. The pretreatment includes softening, clarification, and filtration of the mine water sequentially. Specifically, this can involve adding softening agents such as lime, sodium carbonate, or sodium bicarbonate to the mine water to reduce its hardness, and removing suspended solids through clarification and filtration. After pretreatment, the mine water contains chloride ions ≤ 1000 mg / L, calcium ions ≤ 1000 mg / L, magnesium ions ≤ 200 mg / L, sodium ions ≤ 1000 mg / L, and sulfate ions ≤ 500 mg / L.

[0051] The pretreated mine water of this invention can be partially sent to the preheater A14 and partially sent to the second heat exchanger 10, where it exchanges heat with the material from the evaporator B19 before being sent back to the preheater A14. This process not only recovers heat from the liquid phase in the evaporator B19 and lowers the solution temperature entering the salt recovery unit, facilitating the crystallization and precipitation of salt, but also increases the temperature of the mine water before preheating, promoting the evaporation of the mine water.

[0052] In this invention, preheaters and evaporators are configured correspondingly. In some specific embodiments, when both the number of preheaters and evaporators is one, the mine water feed pressure is 0.2~1.5 MPaG. The mine water is preheated to 90~120℃ by preheater A14 and then sent to evaporator B19. The mine water in evaporator B19 is heated to 130~180℃ by reboiler C124, and the generated steam is sent to compressor 11 and pressurized to 1~1.5 MPaG. It is then sequentially sent to reboiler C1 and preheater A14, providing heat sources for heating and evaporating the mine water in evaporator B19 and for preheating the mine water in preheater A14, respectively. After heat exchange, the mine water condenses into a liquid phase and enters the water storage unit. When preheater A1 is working, an ultrasonic transmitter can be activated to prevent and remove scale. The ultrasonic transmitter operates at a frequency of 20~50kHz and has an ultrasonic power density of 0.5~2W / cm³. 2 .

[0053] When there are two preheaters and two evaporators, the mine water feed pressure is 0.2~2.4 MPaG. After being preheated by preheaters A1~A2, the mine water is sent to evaporator B28. After being preheated by preheater A14, the temperature is 65~90℃, and after being preheated by preheater A25, the temperature is 110~170℃. The mine water in evaporator B28 is heated to 130~200℃ by reboiler C224. The generated steam is sent to reboiler C124 in evaporator B19, and the remaining liquid phase is sent to evaporator B19. The liquid phase from evaporator B28 is heated by heat exchange with the steam in reboiler C124 in evaporator B19. The generated steam is sent to compressor 11 and pressurized to 1~2 MPaG. The remaining liquid phase is sent to the salt recovery unit. Steam from evaporator B19 is compressed and heated by the compression unit before being sent to reboiler C223 to provide a heat source for the evaporation of mine water from preheater A2. Steam from reboilers C1-C2 is then sent to the corresponding preheaters A1-A2 after heat exchange, where it preheats the mine water and condenses into a liquid phase before being sent to the water storage unit. When preheaters A1-A2 are operating, an ultrasonic transmitter can be activated to prevent and remove scale. The ultrasonic transmitter operates at a frequency of 20-50 kHz and has an ultrasonic power density of 0.5-2 W / cm³. 2 .

[0054] When there are 3 preheaters, the mine water feed pressure is 0.2~3 MPaG. After being preheated by preheaters A1~A3, the mine water is sent to evaporator B37. After being preheated by preheater A14, the temperature is 65~85℃; after being preheated by preheater A25, the temperature is 90~150℃; and after being preheated by preheater A36, the temperature is 125~250℃. The mine water in evaporator B37 is heated to 130~250℃ by reboiler C322. The generated steam is sent to reboiler C223 in evaporator B28, and the remaining liquid phase is sent to evaporator B28. The liquid phase from evaporator B37 exchanges heat with the steam in reboiler C223 in evaporator B28, heating the liquid phase. The resulting evaporation is sent to evaporator B19, and the remaining liquid phase is sent to evaporator B19. Inside evaporator B19, the liquid phase from evaporator B28 exchanges heat with the steam in reboiler C223, heating the liquid phase. The generated steam is sent to compressor 11 and pressurized to 1-3 MPaG. The remaining liquid phase is sent to the salt recovery unit. The steam from evaporator B19 is compressed and heated by the compression unit before being sent to reboiler C322 to provide a heat source for the evaporation of preheated mine water. The steam in reboilers C1-C3 is sent to the corresponding preheaters A1-A3 after heat exchange, where the preheated mine water condenses into a liquid phase and is then sent to the water storage unit. When preheaters A1-A3 are operating, an ultrasonic transmitter can be activated to prevent and remove scale. The ultrasonic transmitter operates at a frequency of 20-50 kHz and has an ultrasonic power density of 0.5-2 W / cm³. 2 .

[0055] When the evaporators B1-B3 of the present invention are working, the ultrasonic transmitter can be activated to prevent and remove scale. The ultrasonic transmitter operates at a frequency of 20-50 kHz and has an ultrasonic power density of 0.5-2 W / cm². 2 .

[0056] In this invention, mine water from the water storage unit is sent to the clean water chamber after heat exchange in the first heat exchanger 14. Electrolyte concentrated by ionization in the electrolytic cell 16 is sent to the electrolyte chamber after heat exchange in the first heat exchanger 14. Mine water enters the electrolyte chamber from the clean water chamber through the FO membrane to replenish the electrolyte water. Liquid phase from the evaporator B19 is sent to the centrifuge 19 after heat exchange in the second heat exchanger 10.

[0057] In this invention, the mine water feed pressure can be 0.2~3 MPaG, and the mine water is sequentially fed into preheaters A1~A2. n The temperature after heat exchange can be 90~250℃, preferably 125~200℃; after being pressurized by the compression unit, the temperature of the steam can be 150~300℃, preferably 200~250℃; the pressure can be 1~3MPaG, preferably 2~3MPaG. The temperature of the water storage unit can be 25~60℃, preferably 30~50℃.

[0058] The mine water hydrogen production system of this invention has a wide range of applications and can treat mine water containing mainly calcium ions, chloride ions, sodium ions, magnesium ions, sulfate ions, etc. Specifically, the mine water has a chloride ion content of less than or equal to 10,000 mg / L, a calcium ion content of less than or equal to 10,000 mg / L, a magnesium ion content of less than or equal to 1,000 mg / L, a sodium ion content of less than or equal to 10,000 mg / L, and a sulfate ion content of less than or equal to 3,000 mg / L. Furthermore, after purification by the mine water hydrogen production system of this invention, the mine water has a chloride ion content of less than or equal to 1,000 mg / L, a calcium ion content of less than or equal to 1,000 mg / L, a magnesium ion content of less than or equal to 200 mg / L, a sodium ion content of less than or equal to 1,000 mg / L, and a sulfate ion content of less than or equal to 500 mg / L.

[0059] The following examples further illustrate the mine water hydrogen production system and method of the present invention. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.

[0060] The salt content of the mine water to be purified in the following embodiments of the present invention is shown in Table 1.

[0061] Table 1

[0062] Example 1 Mine water hydrogen production system such as Figure 1 As shown, the system includes a mine water feed pipeline 1, a fresh steam feed pipeline 12, a clarification unit 2, a filtration unit 3, preheaters A1~A3, evaporators B1~B3, a water storage tank 13, a compressor 11, a first heat exchanger 14, a mass transfer device 15, an electrolytic cell 16, a second heat exchanger 10, a centrifuge 19, and a photovoltaic cell 21. Evaporators B1-B3 are falling film evaporators. Evaporator B19 contains a reboiler C124, evaporator B28 contains a reboiler C223, and evaporator B37 contains a reboiler C322. Preheaters A1-A3 are all tubular heat exchangers equipped with ultrasonic transmitters. The total heat exchange area of ​​preheaters A1-A3 is 15 m². 2 The total heat exchange area of ​​evaporators B1 to B3 is 30m². 2 .

[0063] Mine water feed line 1, preheaters A14, A25, and A36 are connected in sequence. The upper part of evaporator B37 is connected to the outlet of preheater A36, the top is connected to the inlet of reboiler C223, and the bottom is connected to the upper part of evaporator B28. The outlet of reboiler C322 is connected to the inlet of preheater A36. The top of evaporator B28 is connected to the inlet of reboiler C124, and the bottom is connected to the upper part of evaporator B19. The outlet of reboiler C223 is connected to the inlet of preheater A25. The top of evaporator B19 is connected to the inlet of compressor 11, and the bottom is connected to the second heat exchanger 10 and centrifuge 19 in sequence. The outlet of reboiler C124 is connected to the inlet of preheater A14. The inlet of reboiler C322 is connected to the outlet of compressor 11 and fresh steam feed line 12. The outlets of preheaters A1 to A3 are connected to water storage tank 13.

[0064] The mass transfer device 15 includes a purified water chamber, an electrolyte chamber, and an FO membrane, with the FO membrane disposed between the purified water chamber and the electrolyte chamber. The water storage tank 13, the first heat exchanger 14, and the purified water chamber form a circulation loop, as do the electrolytic cell 16, the first heat exchanger 14, and the electrolyte chamber.

[0065] Electrolyzer 16 is connected to photovoltaic cell 21 and is equipped with hydrogen recovery device 18 and oxygen recovery device 17. Electrolyzer 16 is an alkaline electrolyzer (ALK / AWE).

[0066] The above system is used to produce hydrogen from mine water. The composition of the mine water is shown in Table 1. The specific steps are as follows: Lime, sodium carbonate, and sodium bicarbonate are added to the mine water to reduce its hardness. After clarification and filtration to remove suspended solids, a portion of the water is passed through the second heat exchanger 10 at an inlet flow rate of 1000 kg / h and a pressure of 0.3 MPaG. Then, it is mixed with another portion of the mine water and sent to preheaters A1-A3. There, it exchanges heat with materials from reboilers C1-C3 to reach a temperature of 125°C and a pressure of 0.28 MPaG before entering evaporator B3.

[0067] In evaporator B37, the steam generated from the mine water heated by reboiler C322 is sent to reboiler C223 to provide a heat source for evaporator B28. The remaining liquid phase is sent to evaporator B28 to exchange heat with the steam in reboiler C223. The evaporation generated from this heat exchange is sent to reboiler C124 to provide a heat source for evaporator B19. The remaining liquid phase is sent to evaporator B19 to exchange heat with the steam in reboiler C124. The steam generated from this heat exchange is compressed to 1 MPaG by compressor 11, heated to 180°C, mixed with fresh steam, and then sent to reboiler C322 to provide a heat source for evaporator B37. The remaining liquid phase in evaporator B19 is cooled to 50°C by the second heat exchanger 10 and then enters centrifuge 19 to separate and obtain impurities 20. The ultrasonic power densities of preheaters A1~A3 and evaporators B1~B3 are 0.6 W / cm³. 2 With 1W / cm 2 .

[0068] The materials from reboilers C1 to C3 exchange heat with the mine water in preheaters A1 to A3 and then enter the water storage tank 13. The temperature inside the water storage tank is 50℃ and the pressure is 0.1MPaG.

[0069] Photovoltaic cell 21 provides electrical energy for hydrogen production through water electrolysis in an alkaline electrolyzer (ALK / AWE). The current density of the electrolyzer during the electrolysis process is 250 mA / cm². 2 The electrolyte is a 30wt.% KOH solution. The oxygen produced by electrolysis is sent to the oxygen recovery unit 17. After gas-liquid separation to recover the entrained electrolyte, the oxygen product is obtained. The hydrogen produced by electrolysis is sent to the hydrogen recovery unit 18. After gas-liquid separation to recover the entrained electrolyte, the hydrogen product is obtained by pressure swing adsorption (PSA).

[0070] The high-temperature concentrated electrolyte produced after electrolysis is cooled by exchanging heat with mine water from storage tank 13 through the first heat exchanger 14 before entering the electrolytic cell chamber. After being heated by the first heat exchanger 14, the mine water enters the purification chamber. The mine water purified by the MVR device enters the electrolytic cell chamber through the FO membrane to replenish the concentrated electrolyte. After being diluted with replenished water, the concentrated electrolyte returns to the electrolytic cell 16, and the remaining mine water returns to storage tank 13.

[0071] Example 2 Mine water hydrogen production system such as Figure 2As shown, the system includes a mine water feed pipeline 1, a fresh steam feed pipeline 12, a clarification unit 2, a filtration unit 3, preheaters A1-A2, evaporators B1-B2, a water storage tank 13, a compressor 11, a first heat exchanger 14, a mass transfer device 15, an electrolytic cell 16, a second heat exchanger 10, a centrifuge 19, and a photovoltaic cell 21. Evaporators B1 and B2 are falling film evaporators. Evaporator B19 contains a reboiler C124, and evaporator B28 contains a reboiler C223. Preheaters A1 and A2 are all tubular heat exchangers equipped with ultrasonic transmitters. The total heat exchange area of ​​preheaters A1 and A2 is 10 m². 2 The total heat exchange area of ​​evaporators B1 to B2 is 20m². 2 .

[0072] Mine water feed line 1, preheater A14, and preheater A25 are connected in sequence. The upper part of evaporator B28 is connected to the outlet of preheater A25, the top is connected to the inlet of reboiler C124, and the bottom is connected to the upper part of evaporator B19. The outlet of reboiler C124 is connected to the inlet of preheater A14. The top of evaporator B19 is connected to the inlet of compressor 11, and the bottom is connected to the second heat exchanger 10 and centrifuge 19 in sequence. The inlet of reboiler C223 is connected to the outlet of compressor 11 and fresh steam feed line 12, respectively. The outlet of reboiler C223 is connected to the inlet of preheater A25. The outlets of preheaters A1~A2 are connected to water storage tank 13.

[0073] The mass transfer device 15 includes a purified water chamber, an electrolyte chamber, and an FO membrane, with the FO membrane disposed between the purified water chamber and the electrolyte chamber. The water storage tank 13, the first heat exchanger 14, and the purified water chamber form a circulation loop, as do the electrolytic cell 16, the first heat exchanger 14, and the electrolyte chamber.

[0074] Electrolyzer 16 is connected to photovoltaic cell 21 and is equipped with hydrogen recovery device 18 and oxygen recovery device 17. Electrolyzer 16 is an alkaline electrolyzer (ALK / AWE).

[0075] The above system is used to produce hydrogen from mine water. The composition of the mine water is shown in Table 1. The specific steps are as follows: Lime, sodium carbonate, and sodium bicarbonate are added to the mine water to reduce its hardness. After clarification and filtration to remove suspended solids, a portion of the water is passed through the second heat exchanger 10 at an inlet flow rate of 1000 kg / h and a pressure of 0.3 MPaG. Then, it is mixed with another portion of the mine water and sent to preheaters A1-A2. There, it exchanges heat with materials from reboilers C1-C2 to reach a temperature of 110℃ and a pressure of 0.285 MPaG before entering evaporator B2.

[0076] In evaporator B28, the steam generated from the mine water heated by reboiler C223 is sent to reboiler C124 to provide a heat source for evaporator B19. The remaining liquid phase is sent to evaporator B19 to exchange heat with the steam in reboiler C124. The evaporation generated by the heat exchange is compressed to 1 MPaG by compressor 11, heated to 180℃ and mixed with fresh steam, and then sent to reboiler C322 to provide a heat source for evaporator B37. The remaining liquid phase in evaporator B19 is cooled to 50℃ by the second heat exchanger 10 and then enters centrifuge 19 to separate and obtain impurities 20. The materials from reboilers C1~C2 are cooled by exchanging heat with the mine water in preheaters A1~A2 and then enter water storage tank 13. The temperature in the water storage tank is 50℃ and the pressure is 0.1 MPaG. The ultrasonic power density of preheaters A1~A2 and evaporators B1~B2 is 0.6 W / cm³. 2 With 1W / cm 2 .

[0077] Photovoltaic cell 21 provides electrical energy for hydrogen production through water electrolysis in an alkaline electrolyzer (ALK / AWE). The current density of the electrolyzer during the electrolysis process is 250 mA / cm². 2 The electrolyte is a 30wt.% KOH solution. The oxygen produced by electrolysis is sent to the oxygen recovery unit 17. After gas-liquid separation to recover the entrained electrolyte, the oxygen product is obtained. The hydrogen produced by electrolysis is sent to the hydrogen recovery unit 18. After gas-liquid separation to recover the entrained electrolyte, the hydrogen product is obtained by pressure swing adsorption (PSA).

[0078] The high-temperature concentrated electrolyte produced after electrolysis is cooled by exchanging heat with mine water from storage tank 13 through the first heat exchanger 14 before entering the electrolytic cell chamber. After being heated by the first heat exchanger 14, the mine water enters the purification chamber. The mine water purified by the MVR device enters the electrolytic cell chamber through the FO membrane to replenish the concentrated electrolyte. After being diluted with replenished water, the concentrated electrolyte returns to the electrolytic cell 16, and the remaining mine water returns to storage tank 13.

[0079] Example 3 Mine water hydrogen production system such as Figure 3 As shown, the system includes a mine water feed pipeline 1, a fresh steam feed pipeline 12, a clarification unit 2, a filtration unit 3, a preheater A14, an evaporator B19, a water storage tank 13, a compressor 11, a first heat exchanger 14, a mass transfer device 15, an electrolytic cell 16, a second heat exchanger 10, a centrifuge 19, and a photovoltaic cell 21. Evaporator B19 is a falling film evaporator, and a reboiler C124 is installed inside evaporator B19. Preheater A1 is a tubular heat exchanger equipped with an ultrasonic transmitter, and evaporator B1 is also a tubular heat exchanger equipped with an ultrasonic transmitter. The total heat exchange area of ​​preheater A1 is 5 m². 2 The total heat exchange area of ​​evaporator B1 is 10m². 2 .

[0080] The upper parts of the mine water feed pipeline 1, preheater A14, and evaporator B19 are connected in sequence. The top of evaporator B19 is connected to the inlet of compressor 11, and the bottom is connected to the second heat exchanger 10 and centrifuge 19 in sequence. The inlet of reboiler C124 is connected to the outlet of compressor 11 and fresh steam feed pipeline 12, and the outlet is connected to the inlet of preheater A14. The outlet of preheater A14 is connected to water storage tank 13. Mass transfer device 15 includes a clean water chamber, an electrolyte chamber, and an FO membrane, with the FO membrane disposed between the clean water chamber and the electrolyte chamber. Water storage tank 13, first heat exchanger 14, and clean water chamber form a circulation loop, as do electrolytic cell 16, first heat exchanger 14, and electrolyte chamber.

[0081] The mass transfer device 15 includes a purified water chamber, an electrolyte chamber, and an FO membrane, with the FO membrane disposed between the purified water chamber and the electrolyte chamber. The water storage tank 13, the first heat exchanger 14, and the purified water chamber form a circulation loop, as do the electrolytic cell 16, the first heat exchanger 14, and the electrolyte chamber.

[0082] Electrolyzer 16 is connected to photovoltaic cell 21 and is equipped with hydrogen recovery device 18 and oxygen recovery device 17. Electrolyzer 16 is an alkaline electrolyzer (ALK / AWE).

[0083] The above system is used to produce hydrogen from mine water. The composition of the mine water is shown in Table 1. The specific steps are as follows: Lime, sodium carbonate, and sodium bicarbonate are added to the mine water to reduce its hardness. After clarification and filtration to remove suspended solids, a portion of the water is mixed with another portion of the mine water in the second heat exchanger 10 at an inlet flow rate of 1000 kg / h and a pressure of 0.3 MPaG. The mixture is then sent to the preheater A1, where it exchanges heat with the material from the reboiler C1 to reach a temperature of 125°C and a pressure of 0.29 MPaG before entering the evaporator B19.

[0084] In evaporator B19, the steam generated from the mine water heated by reboiler C124 is compressed to 1 MPaG by compressor 11, heated to 180℃, mixed with fresh steam, and then sent to reboiler C124 to provide a heat source for evaporator B19. The remaining liquid phase is cooled to 50℃ and pressured to 0.15 MPaG by the second heat exchanger 10 before entering centrifuge 19 to separate impurities 20. The ultrasonic power densities of preheater A1 and evaporator B1 are 0.6 W / cm³, respectively. 2 With 1W / cm 2 .

[0085] The material from the reboiler C124 is cooled down by exchanging heat with the mine water in the preheater A14 and then enters the water storage tank 13. The temperature in the water storage tank 13 is 50°C and the pressure is 0.1 MPaG.

[0086] Photovoltaic cell 21 provides electrical energy for hydrogen production through water electrolysis in an alkaline electrolyzer (ALK / AWE). The current density of the electrolyzer during the electrolysis process is 250 mA / cm². 2 The electrolyte is a 30wt.% KOH solution. The oxygen produced by electrolysis is sent to the oxygen recovery unit 17. After gas-liquid separation to recover the entrained electrolyte, the oxygen product is obtained. The hydrogen produced by electrolysis is sent to the hydrogen recovery unit 18. After gas-liquid separation to recover the entrained electrolyte, the hydrogen product is obtained by pressure swing adsorption (PSA).

[0087] The high-temperature concentrated electrolyte produced after electrolysis is cooled by exchanging heat with mine water from storage tank 13 through the first heat exchanger 14 before entering the electrolytic cell chamber. After being heated by the first heat exchanger 14, the mine water enters the purification chamber. The mine water purified by the MVR device enters the electrolytic cell chamber through the FO membrane to replenish the concentrated electrolyte. After being diluted with replenished water, the concentrated electrolyte returns to the electrolytic cell 16, and the remaining mine water returns to storage tank 13.

[0088] Example 4 The system used in Example 1 was used for hydrogen production from mine water, but it differed from Example 1 in that the current density of the electrolyzer during the electrolysis process was 500 mA / cm². 2 .

[0089] Example 5 The system used in Example 1 for hydrogen production from mine water differs from that in Example 1 in that: the photovoltaic cell 21 is an anion exchange membrane electrolyzer (AEM), and the current density of the electrolyzer during electrolysis is 500 mA / cm². 2 .

[0090] Example 6 The system used in Example 1 was used for mine water hydrogen production, with the difference that the total heat exchange area of ​​preheaters A1 to A3 is 25m². 2 The total heat exchange area of ​​evaporators B1 to B3 is 40m². 2 .

[0091] The specific operation is as follows: lime, sodium carbonate, and sodium bicarbonate are added to the mine water to reduce its hardness. After clarification and filtration to remove suspended solids, part of the water is passed through the second heat exchanger 10 at an inlet flow rate of 1000 kg / h and a pressure of 3 MPaG. Then, it is mixed with another part of the mine water and sent to the preheaters A1~A3. The water is then exchanged with the materials from the reboilers C1~C3 to reach a temperature of 200℃ and a pressure of 2.95 MPaG before entering the evaporator B37.

[0092] In evaporator B37, the steam generated from the mine water heated by reboiler C322 is sent to reboiler C223 to provide a heat source for evaporator B28. The remaining liquid phase is sent to evaporator B28 to exchange heat with the steam in reboiler C223. The evaporation generated from this heat exchange is sent to reboiler C124 to provide a heat source for evaporator B19. The remaining liquid phase is sent to evaporator B19 to exchange heat with the steam in reboiler C124. The steam generated from this heat exchange is compressed to 3 MPaG by compressor 11, heated to 260℃, mixed with fresh steam, and then sent to reboiler C322 to provide a heat source for evaporator B37. The remaining liquid phase in evaporator B19 is cooled to 50℃ by the second heat exchanger 10 and then enters centrifuge 19 to separate and obtain impurities 20. The ultrasonic power density of preheaters A1~A3 and evaporators B1~B3 is 0.6 W / cm³. 2 With 1W / cm 2 .

[0093] The materials from reboilers C1 to C3 exchange heat with the mine water in preheaters A1 to A3 and then enter the water storage tank 13. The temperature inside the water storage tank is 50℃ and the pressure is 0.1MPaG.

[0094] Photovoltaic cell 21 provides electrical energy for hydrogen production through water electrolysis in an alkaline electrolyzer (ALK / AWE). The current density of the electrolyzer during the electrolysis process is 250 mA / cm². 2 The electrolyte is a 30wt.% KOH solution. The oxygen produced by electrolysis is sent to the oxygen recovery unit 17. After gas-liquid separation to recover the entrained electrolyte, the oxygen product is obtained. The hydrogen produced by electrolysis is sent to the hydrogen recovery unit 18. After gas-liquid separation to recover the entrained electrolyte, the hydrogen product is obtained by pressure swing adsorption (PSA).

[0095] The high-temperature concentrated electrolyte produced after electrolysis is cooled by exchanging heat with mine water from storage tank 13 through the first heat exchanger 14 before entering the electrolytic cell chamber. After being heated by the first heat exchanger 14, the mine water enters the purification chamber. The mine water purified by the MVR device enters the electrolytic cell chamber through the FO membrane to replenish the concentrated electrolyte. After being diluted with replenished water, the concentrated electrolyte returns to the electrolytic cell 16, and the remaining mine water returns to storage tank 13.

[0096] Example 7 The system used in Example 1 was used for mine water hydrogen production, with the difference that the total heat exchange area of ​​preheaters A1 to A2 was 18m². 2 The total heat exchange area of ​​evaporators B1 to B2 is 33m². 2 .

[0097] The specific operation is as follows: lime, sodium carbonate, and sodium bicarbonate are added to the mine water to reduce its hardness. After clarification and filtration to remove suspended solids, part of the water is passed through the second heat exchanger 10 at an inlet flow rate of 1000 kg / h and a pressure of 1 MPaG. Then, it is mixed with another part of the mine water and sent to the preheaters A1~A3. The water is then exchanged with the materials from the reboilers C1~C3 to reach a temperature of 160℃ and a pressure of 0.95 MPaG before entering the evaporator B37.

[0098] In evaporator B37, the steam generated from the mine water heated by reboiler C322 is sent to reboiler C223 to provide a heat source for evaporator B28. The remaining liquid phase is sent to evaporator B28 to exchange heat with the steam in reboiler C223. The evaporation generated from this heat exchange is sent to reboiler C124 to provide a heat source for evaporator B19. The remaining liquid phase is sent to evaporator B19 to exchange heat with the steam in reboiler C124. The steam generated from this heat exchange is compressed to 1 MPaG by compressor 11, heated to 180°C, mixed with fresh steam, and then sent to reboiler C322 to provide a heat source for evaporator B37. The remaining liquid phase in evaporator B19 is cooled to 50°C by the second heat exchanger 10 and then enters centrifuge 19 to separate and obtain impurities 20. The ultrasonic power density of preheaters A1~A3 and evaporators B1~B3 is 0.6 W / cm³. 2 With 1W / cm 2 .

[0099] The materials from reboilers C1 to C3 exchange heat with the mine water in preheaters A1 to A3 and then enter the water storage tank 13. The temperature inside the water storage tank is 50℃ and the pressure is 0.1MPaG.

[0100] Photovoltaic cell 21 provides electrical energy for hydrogen production through water electrolysis in an alkaline electrolyzer (ALK / AWE). The current density of the electrolyzer during the electrolysis process is 250 mA / cm². 2 The electrolyte is a 30wt.% KOH solution. The oxygen produced by electrolysis is sent to the oxygen recovery unit 17. After gas-liquid separation to recover the entrained electrolyte, the oxygen product is obtained. The hydrogen produced by electrolysis is sent to the hydrogen recovery unit 18. After gas-liquid separation to recover the entrained electrolyte, the hydrogen product is obtained by pressure swing adsorption (PSA).

[0101] The high-temperature concentrated electrolyte produced after electrolysis is cooled by exchanging heat with mine water from storage tank 13 through the first heat exchanger 14 before entering the electrolytic cell chamber. After being heated by the first heat exchanger 14, the mine water enters the purification chamber. The mine water purified by the MVR device enters the electrolytic cell chamber through the FO membrane to replenish the concentrated electrolyte. After being diluted with replenished water, the concentrated electrolyte returns to the electrolytic cell 16, and the remaining mine water returns to storage tank 13.

[0102] Example 8 The system used in Example 1 for hydrogen production from mine water differs from Example 1 in that the total heat exchange area of ​​preheaters A1 to A3 is 22 m². 2 The total heat exchange area of ​​evaporators B1 to B3 is 37m². 2 .

[0103] The specific operation is as follows: lime, sodium carbonate, and sodium bicarbonate are added to the mine water to reduce its hardness. After clarification and filtration to remove suspended solids, part of the water is heated by the second heat exchanger 10 under an inlet pressure of 2 MPaG. Then it is mixed with another part of the mine water and sent to the preheaters A1~A3. The water is heated by the materials from the reboilers C1~C3 to reach a temperature of 200℃ and a pressure of 1.95 MPaG before entering the evaporator B3.

[0104] In evaporator B37, the steam generated from the mine water heated by reboiler C322 is sent to reboiler C223 to provide a heat source for evaporator B28. The remaining liquid phase is sent to evaporator B28 to exchange heat with the steam in reboiler C223. The evaporation generated from this heat exchange is sent to reboiler C124 to provide a heat source for evaporator B19. The remaining liquid phase is sent to evaporator B19 to exchange heat with the steam in reboiler C124. The steam generated from this heat exchange is compressed to 2 MPaG by compressor 11, heated to 210℃, mixed with fresh steam, and then sent to reboiler C322 to provide a heat source for evaporator B37. The remaining liquid phase in evaporator B19 is cooled to 50℃ by the second heat exchanger 10 and then enters centrifuge 19 to separate and obtain impurities 20. The ultrasonic power densities of preheaters A1~A3 and evaporators B1~B3 are 0.6 W / cm³. 2 With 1W / cm 2 The total heat exchange area of ​​preheaters A1 to A3 is 22 m². 2 The total heat exchange area of ​​evaporators B1 to B3 is 37m². 2 .

[0105] The materials from reboilers C1 to C3 exchange heat with the mine water in preheaters A1 to A3 and then enter the water storage tank 13. The temperature inside the water storage tank is 50℃ and the pressure is 0.1MPaG.

[0106] Photovoltaic cell 21 provides electrical energy for hydrogen production through water electrolysis in an alkaline electrolyzer (ALK / AWE). The current density of the electrolyzer during the electrolysis process is 250 mA / cm². 2 The electrolyte is a 30wt.% KOH solution. The oxygen produced by electrolysis is sent to the oxygen recovery unit 17. After gas-liquid separation to recover the entrained electrolyte, the oxygen product is obtained. The hydrogen produced by electrolysis is sent to the hydrogen recovery unit 18. After gas-liquid separation to recover the entrained electrolyte, the hydrogen product is obtained by pressure swing adsorption (PSA).

[0107] The high-temperature concentrated electrolyte produced after electrolysis is cooled by exchanging heat with mine water from storage tank 13 through the first heat exchanger 14 before entering the electrolytic cell chamber. After being heated by the first heat exchanger 14, the mine water enters the purification chamber. The mine water purified by the MVR device enters the electrolytic cell chamber through the FO membrane to replenish the concentrated electrolyte. After being diluted with replenished water, the concentrated electrolyte returns to the electrolytic cell 16, and the remaining mine water returns to storage tank 13.

[0108] Comparative Example 1 The system for producing hydrogen from mine water was implemented according to Example 1, except that the FO membrane in the mass transfer device was replaced with a PTFE membrane (the mass transfer rate of water is 0.1 g / (cm³)). 2 ·h)).

[0109] Comparative Example 2 The difference from Example 1 is that untreated mine water is used directly for hydrogen production, and a PTFE membrane (with a water mass transfer rate of 0.1 g / (cm³)) is utilized. 2 Mass transfer is performed using h).

[0110] The salt content of the purified mine water and the stable operating time of the mine water hydrogen production systems of Examples 1-8 and Comparative Examples 1-2 are recorded in Table 2.

[0111] Table 2

[0112] As shown in Table 1, the mine water hydrogen production system of Examples 1-8 of the present invention can reduce the content of impurity ions in mine water, reduce scaling in evaporators and heat exchangers, and ensure long-term operation of evaporation equipment and mass transfer devices.

[0113] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A mine water hydrogen production system, characterized in that, The system includes: a mine water feed pipeline (1), a fresh steam feed pipeline (12), a preheating unit, an evaporation unit, a compression unit, a water storage unit, a phase change mass transfer unit, an electrolysis unit, and a salt recovery unit; among which, The preheating unit includes preheaters A1~A1 connected in series. n The inlet of the preheater A1 (4) is connected to the mine water feed pipeline (1); The evaporation unit includes evaporators B1~B1 connected in series. n The evaporators B1~B n Each of the evaporators is equipped with a reboiler; the evaporator B n The upper part of the preheater A n The outlet connection; the evaporator B n The inlet of the reboiler is connected to the outlet of the compression unit; the evaporator B n The top of the evaporator B n-1 The reboiler inlet is connected inside, and the bottom is connected to the evaporator B. n-1 The upper part is connected, and so on, until the top of the evaporator B1 is connected to the inlet of the compression unit and the bottom is connected to the salt recovery unit; any of the evaporators B m The outlet of the reboiler inside is connected to the preheater A with the corresponding number. m connect; The outlet of the compression unit is connected to the fresh steam feed line (12); The water storage unit is connected to the preheaters A1~A1 respectively. n connect; The phase change mass transfer unit includes a first heat exchanger (14) and a mass transfer device (15), and the water storage unit, the first heat exchanger (14) and the mass transfer device (15) form a circulation loop; The electrolysis unit includes an electrolytic cell (16) connected in series and an energy supply unit. The electrolytic cell (16), the first heat exchanger (14), and the mass transfer device (15) form a circulation loop. n is an integer greater than or equal to 1, and m is an integer from 1 to n.

2. The system according to claim 1, characterized in that, The system also includes a pretreatment unit, which is connected to the mine water feed pipeline (1) and the inlet of the preheater A1 (4).

3. The system according to claim 1 or 2, characterized in that, The preheaters A1~A n Equipped with an ultrasonic transmitter; and / or The evaporators B1~B n Equipped with an ultrasonic transmitter; and / or The compression unit includes at least one compressor (11).

4. The system according to any one of claims 1-3, characterized in that, The mass transfer device (15) includes a water purification chamber, an electrolyte chamber, and an FO membrane. The FO membrane is disposed between the water purification chamber and the electrolyte chamber. The water storage unit, the first heat exchanger (14), and the water purification chamber form a circulation loop. The electrolytic cell, the first heat exchanger (14), and the electrolyte chamber form a circulation loop.

5. The system according to any one of claims 1-4, characterized in that, The salt recovery unit includes a second heat exchanger (10) and a centrifuge (19). The bottom of the evaporator B1 is connected in sequence to the second heat exchanger (10) and the centrifuge (19). The second heat exchanger (10) is connected to the mine water feed pipeline (1) and the preheater A1, respectively.

6. The system according to any one of claims 1-5, characterized in that, The electrolytic cell (16) is equipped with a hydrogen recovery device (18) and an oxygen recovery device (17). Preferably, the hydrogen recovery device (18) includes a hydrogen gas-liquid separator and a hydrogen purification device, wherein the hydrogen purification device includes a membrane separator and / or an adsorption tower; and the oxygen recovery device includes an oxygen gas-liquid separator.

7. A method for producing hydrogen from mine water, characterized in that, The method is performed in the system described in any one of claims 1-6, and includes the following steps: 1) At least a portion of the mine water pretreated by the pretreatment unit is sequentially fed into preheaters A1~A n After heat exchange, it is sent to evaporator B. n ; 2) Evaporator B n Inside, the gas phase generated by the reboiler heating of mine water is sent to evaporator B. n-1 The reboiler inside is connected in sequence with evaporator B. n-1 Preheater A n-1 After heat exchange, the mine water is sent to the water storage unit, and the remaining liquid phase is sent to evaporator B. n-1 The process continues in sequence until the gas phase in evaporator B1 (9) is sent to the compression unit and the remaining liquid phase is sent to the salt recovery unit. 3) The gas phase from evaporator B1 (9) is pressurized by the compression unit and mixed with fresh steam, and then sent to evaporator B. n The reboiler inside is connected in sequence with evaporator B. n Preheater A n The mine water is heated and then sent to the water storage unit. 4) The mine water from the water storage unit enters the mass transfer device (15) after heat exchange in the first heat exchanger (14). The electrolyte concentrated by ionization in the electrolytic cell (16) is replenished with water in the mass transfer device (15) after heat exchange in the first heat exchanger (14), and then returns to the electrolytic cell (16). The remaining mine water returns to the water storage unit.

8. The method according to claim 7, characterized in that, In step 1), the pretreatment includes: sequentially softening, clarifying, and filtering the mine water; and / or Part of the pretreated mine water is sent to the preheater A1 (4), and the other part is sent to the second heat exchanger (10) to exchange heat with the liquid phase from the evaporator B1 (9) before being sent to the preheater A1 (4).

9. The method according to claim 7 or 8, characterized in that, Mine water from the water storage unit is sent to the clean water chamber after heat exchange in the first heat exchanger (14). Electrolyte concentrated by ionization in the electrolytic cell (16) is sent to the electrolyte chamber after heat exchange in the first heat exchanger (14). Mine water enters the electrolyte chamber from the clean water chamber through the FO membrane to replenish the electrolyte water. Liquid phase from the evaporator B1 is sent to the centrifuge (19) after heat exchange in the second heat exchanger (10).

10. The method according to any one of claims 7-9, characterized in that, The mine water feed pressure is 0.2~3 MPaG, and the mine water is sequentially fed into the preheaters A1~A1. n The temperature after heat exchange is 90~250℃; and / or After being pressurized by the compression unit, the steam temperature is 150~300℃ and the pressure is 1~3MPaG; and / or The temperature of the water storage unit is 25~60℃.

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