Membrane-free single-tank water electrolysis hydrogen production-electroplating wastewater enrichment coupling device

Abstract

The utility model belongs to the field of industrial wastewater purification equipment, and particularly discloses a membrane-free single-tank water electrolysis hydrogen production-electroplating wastewater enrichment coupling device which comprises a membrane-free single tank, an oxygen evolution tank and a hollow sealing tank, the membrane-free single tank is a box body with a cover, and a cathode electrode and an anode electrode which are connected with each other are arranged in the box body; the membrane-free single tank, the oxygen evolution tank body and the hollow sealing tank are sequentially connected to form a closed circulation loop; the membrane-free single tank is used as a place for electrolytic hydrogen production of a to-be-electrolyzed solution and is also used for inputting electrolytic residual liquid into the oxygen evolution tank body, the oxygen evolution tank body is a place for oxygen evolution reaction and is also used for inputting reaction residual liquid after the oxygen evolution reaction into the hollow sealing tank, and the hollow sealing tank is used as a transfer place; and the reaction residual liquid is input into the membrane-free single tank to participate in the next round of electrolytic reaction. According to the device, the functions of electrolytic hydrogen production, wastewater treatment and metal ion enrichment can be synchronously and circularly carried out in one set of device.

Description

Technical Field

[0001] This application belongs to the technical field of industrial wastewater purification equipment, and more specifically, relates to a membrane-free single-tank electrolysis water production hydrogen-electroplating wastewater enrichment coupling device. Background Technology

[0002] Water electrolysis for hydrogen production uses water as its raw material, which is widely available and relatively inexpensive. The process produces almost no pollutants, and the resulting hydrogen is highly pure, offering significant cleanliness advantages. More importantly, the electricity driving water splitting can be converted from renewable energy sources such as solar, wind, hydropower, and geothermal energy. These renewable energy sources are intermittent and fluctuate, with unstable supply in time and space. Converting them into hydrogen fuel through water electrolysis and storing it effectively compensates for the gaps in sustainable energy supply over time and space. Therefore, water electrolysis for hydrogen production is widely recognized as the most promising green hydrogen production route. However, when using water electrolysis to treat electroplating wastewater, existing methods require the use of ion exchange membranes in the reaction vessel to avoid hydrogen-oxygen mixing issues. Ion exchange membranes are expensive, increasing production costs. Furthermore, organic matter and colloids in electroplating wastewater easily clog the membrane pores, necessitating frequent cleaning or replacement of membrane modules, further increasing operating costs. In addition, the use of ion exchange membranes also has the following problems: (1) Proton exchange membranes need to work in an acidic environment, and their chemical stability and proton conductivity will be affected under long-term high current density operation; (2) It is difficult to balance the ionic conductivity and dimensional stability of anion exchange membranes, which limits the increase of current density and hydrogen production efficiency. The catalyst stability is poor and cannot meet the needs of long-term, large-scale industrial applications. In terms of system operation, the traditional water electrolysis process requires stable power input to ensure the balance of H2 and O2 yields in order to reduce the pressure difference across the membrane. However, OER has a slower kinetic characteristic than HER. When the input power changes, the response rates of the two are different, which will cause an instantaneous increase in the pressure difference across the membrane, posing a risk of membrane damage and gas mixing. Therefore, a new electrolysis device is needed to be suitable for hydrogen production and purification of industrial electroplating wastewater. Utility Model Content

[0003] In view of the shortcomings of the prior art, the purpose of this application is to provide a membraneless single-tank electrolysis water production hydrogen production-electroplating wastewater enrichment coupling device, which aims to solve the problem that existing electrolysis water production hydrogen production devices cannot achieve efficient and stable electrolysis purification of electroplating wastewater.

[0004] To achieve the above objectives, this application provides a membraneless single-tank electrolysis water production hydrogen-electroplating wastewater enrichment coupling device, comprising a membraneless single tank, an oxygen evolution tank, and a hollow sealed tank. The membraneless single tank is a covered box, and a cathode electrode and an anode electrode are connected in series inside the box. The membraneless single tank, the oxygen evolution tank, and the hollow sealed tank are connected in sequence to form a closed loop. The membraneless single tank serves as the site for electrolyzing the electrolyte to produce hydrogen, and also serves to input the residual electrolyte into the oxygen evolution tank. The oxygen evolution tank serves as the site for the oxygen evolution reaction, and also serves to input the residual reaction liquid after the oxygen evolution reaction into the hollow sealed tank. The hollow sealed tank serves as a transfer site to input the residual reaction liquid into the membraneless single tank to participate in the next round of electrolysis reaction.

[0005] Furthermore, the top cover of the membraneless single tank is provided with a first hydrogen outlet and an air outlet, the upper part of its side wall is provided with a residual liquid inlet, and the lower part of its side wall is provided with a residual liquid outlet; the hollow sealed tank is provided with a first liquid outlet and a first liquid inlet; the oxygen evolution tank is provided with a fourth liquid inlet and a second liquid outlet, the residual liquid outlet is connected to the fourth liquid inlet, the second liquid outlet is connected to the first liquid inlet, and the residual liquid inlet is connected to the first liquid outlet to form a closed loop.

[0006] Furthermore, the lower part of the hollow sealed container is also provided with a metal ion enrichment residual liquid outlet.

[0007] Furthermore, a first heating device is provided inside the membrane-free single tank, and the first heating device is located between the cathode electrode and the anode electrode.

[0008] Furthermore, a magnetic stir bar is provided at the bottom of the membrane-free single tank, and the magnetic stir bar is located between the cathode electrode and the anode electrode.

[0009] Furthermore, a first water pump is provided between the first liquid outlet and the residual liquid inlet; a second water pump is provided between the first liquid inlet and the second liquid outlet; and a third water pump is provided between the fourth liquid inlet and the residual liquid outlet.

[0010] Furthermore, a second heating device is provided inside the oxygen evolution tank.

[0011] Furthermore, the top of the oxygen evolution tank is provided with an oxygen outlet and a vacuum pump connection port.

[0012] Furthermore, the oxygen evolution tank is equipped with an oxygen evolution catalyst, which is formed by multiple oxygen evolution catalyst plates connected in series.

[0013] Furthermore, the upper side wall of the membraneless single tank is also provided with an inlet for the electrolyte to be ingested.

[0014] Overall, the technical solutions conceived in this application have the following beneficial effects compared with the prior art:

[0015] (1) This application avoids hydrogen and oxygen mixing through spatial separation design (such as hollow sealed tank and oxygen evolution tank), eliminating the need for expensive membrane components and reducing membrane fouling and replacement costs; the closed-loop design of one tank and two tanks realizes the simultaneous production of hydrogen and oxygen, as well as the rapid exchange of solutions within the three. Hydrogen and oxygen can be produced simultaneously in the single tank and oxygen evolution tank, which not only saves a lot of time, but also enables the separate preparation and collection of high-purity hydrogen and oxygen.

[0016] (2) This application avoids the problem of traditional electroplating wastewater treatment requiring the addition of large amounts of reagents. It achieves pollutant degradation through electrolytic oxidation-reduction reaction, reducing reagent use and sludge production.

[0017] (3) This application directly decomposes water molecules in electroplating wastewater through membrane-free single-tank electrolysis to generate hydrogen (cathode) and oxygen (anode), while using anodic oxidation reaction to degrade organic matter in wastewater and reduce heavy metal ions, thereby achieving multiple objectives of wastewater treatment, hydrogen production and metal ion enrichment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a membraneless single-tank electrolysis water production hydrogen-electroplating wastewater enrichment coupling device provided in an embodiment of this application.

[0019] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0020] 1-First hydrogen outlet, 2-Air outlet; 31-Residual liquid inlet, 32-Residual liquid outlet; 4-Electrolyte inlet; 5-Cathode electrode; 6-Anode electrode; 7-Magnetic stir bar; 81-First heating device, 82-Second heating device; 9-Membrane-free single tank; 10-Oxygen evolution tank; 11-Oxygen evolution catalyst; 12-Hose; 13-Hollow sealed tank, 131-First outlet, 132-First inlet; 14-Oxygen outlet; 15-Metal ion enrichment residual liquid outlet; 16-Third inlet, 17-Fourth inlet, 18-Second outlet, 19-First water pump, 20-Second water pump, 21-Third water pump, 22-Vacuum pump connection port. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0022] In this article, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The symbol " / " in this article indicates that the related objects are in an "or" relationship; for example, A / B means A or B.

[0023] The terms "first" and "second," etc., used in the specification and claims herein are used to distinguish different objects, not to describe a specific order of objects. For example, "first response message" and "second response message," etc., are used to distinguish different response messages, not to describe a specific order of response messages.

[0024] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0025] In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more, for example, multiple processing units means two or more processing units, multiple elements means two or more elements, etc.

[0026] The embodiments of this application are described below with reference to the accompanying drawings.

[0027] This embodiment provides a membraneless single-tank electrolysis water production hydrogen-electroplating wastewater enrichment coupling device, including a membraneless single tank 9, a hollow sealed tank 13, and an oxygen evolution tank 10. The membraneless single tank 9 is a covered box with a first hydrogen outlet 1 and an air outlet 2 on its top cover. A residual liquid inlet 31 is provided on the upper part of its side wall, and a residual liquid outlet 32 ​​is provided on the lower part of its side wall. A cathode electrode 5 and an anode electrode 6 are suspended inside the box, and the two electrodes are connected by wires and respectively connected to a current supply unit. The hollow sealed tank 13 is provided with a first liquid outlet 131 and a first liquid inlet 10. 32 and metal ion enrichment residual liquid outlet 15, the metal ion enrichment residual liquid outlet 15 is located at the lower part of the hollow sealed tank 13, used to discharge the waste liquid enriched with metal ions after each cycle reaction; the oxygen evolution tank 10 is a cylindrical tank, on which a third liquid inlet 16, a fourth liquid inlet 17 and a second liquid outlet 18 are arranged sequentially from high to low. The residual liquid outlet 32 ​​is connected to the fourth liquid inlet 17 through a pipe, the second liquid outlet 18 is connected to the first liquid inlet 132 through a hose 12, and the residual liquid inlet 31 is connected to the first liquid outlet 131 through a pipe to form a closed loop.

[0028] The aforementioned membrane-free single tank 9 is equipped with a first heating device 81, located between the cathode electrode 5 and the anode electrode 6. This device heats the electroplating wastewater within the membrane-free single tank to a preset reaction temperature. The first reaction device 81 can be an externally powered heating rod or other devices with similar heating functions. A magnetic stir bar 7 is located at its bottom, between the cathode electrode 5 and the anode electrode 6, and continuously rotates to promote the hydrogen evolution reaction within the membrane-free single tank.

[0029] A first water pump 19 is provided between the aforementioned first liquid outlet 131 and the residual liquid inlet 31 to pump the reaction residual liquid collected in the hollow sealed tank 13 into the membraneless single tank 9.

[0030] A second water pump 20 is provided between the first liquid inlet 132 and the second liquid outlet 18 to input the residual liquid from the oxygen evolution reaction in the oxygen evolution tank 10 into the hollow sealed tank 13.

[0031] A third water pump 21 is provided between the aforementioned fourth liquid inlet 17 and the residual liquid outlet 32, which is used to pump the residual liquid after the hydrogen evolution reaction in the membraneless single tank 9 into the oxygen evolution tank 10 for oxygen evolution reaction.

[0032] The aforementioned oxygen evolution tank 10 is equipped with a second heating device 82 for heating the reaction solution therein to accelerate the oxygen evolution reaction. The second heating device 82 may be the same as or different from the first heating device 81. The top of the oxygen evolution tank 10 is also equipped with an oxygen outlet 14 and a vacuum pump connection port 22. During the reaction, the oxygen generated in the oxygen evolution tank 10 can be collected separately through the oxygen outlet 14. The vacuum pump connection port 22 is used to connect a vacuum pump before the oxygen evolution reaction to extract excess air from the oxygen evolution tank 10.

[0033] The oxygen evolution tank 10 is also equipped with an oxygen evolution catalyst 11. The oxygen evolution catalyst 11 is formed by multiple oxygen evolution catalyst plates connected in series and suspended in the middle of the oxygen evolution tank 10 to participate in the oxygen evolution reaction.

[0034] The working principle of the aforementioned membrane-free single-tank electrolysis water production-electroplating wastewater enrichment coupling device is as follows:

[0035] Before the S1 reaction begins, keep the first water pump 19, the second water pump 20, and the third water pump 21 closed. Inject a near-neutral electroplating wastewater mixture containing 1 mol / L to 3 mol / L sodium bromide, 0.1 mol / L to 1.0 mol / L boric acid, and 0.1 mmol / L to 0.5 mmol / L sodium dichromate buffer into the non-membrane single tank 9 through the electrolyte inlet 4. A dual-electrode system is formed, with the hydrogen evolution electrode as the cathode and the bromine evolution electrode as the anode. The anode and cathode are platinum wire and platinum sheet, respectively. The electroplating wastewater solution injected into the non-membrane single tank 9 fills 4 / 5 of the total tank volume. Air is extracted from the non-membrane single tank 9 through the hydrogen gas 21. The first heating device 81 is turned on to raise the temperature of the electroplating wastewater solution to the specified temperature. During the reaction, the magnetic stir bar 17 can be turned on and continuously rotated for 30 seconds, then turned off to promote the reaction within the tank.

[0036] S2 applies current to the two electrodes and collects H2 generated in the tank from the first hydrogen outlet 1. Simultaneously, air is extracted from the oxygen evolution tank 10 through the vacuum pump connection port 22 using a vacuum pump. Then, a near-neutral electroplating wastewater mixed solution containing 1 mol / L~3 mol / L sodium bromate, 0.1 mol / L~1.0 mol / L boric acid, and 0.1 mmol / L~0.5 mmol / L sodium dichromate buffer is injected into the oxygen evolution tank 10. The solution reacts with the oxygen evolution catalyst inside to generate oxygen. During the reaction, the electroplating wastewater mixed solution can be heated by the second heating device 82.

[0037] O2 is collected from the top of the oxygen evolution tank 10 through the oxygen outlet 14. The first round of reaction ends when the voltage in the tank increases significantly and no bubbles are generated on the oxygen evolution catalyst 11. The power is then cut off, and the residual hydrogen and oxygen in the oxygen evolution tank 10 are extracted from the vacuum pump connection port 22 using a vacuum pump.

[0038] S3 opens the second water pump 20 to pump the solution in the oxygen evolution tank 10 into the hollow sealed tank 13, and then closes the second water pump 20; then opens the third water pump 21 to transfer the mixed solution in the membraneless single tank 9 into the oxygen evolution tank 10, and then closes the third water pump 21; finally opens the first water pump 19 to pump the solution in the hollow sealed tank 13 into the membraneless single tank 9, and then closes the first water pump 19, starting the second round of reaction according to the same reaction process;

[0039] S4 repeats steps S2 and S3 until the electrolyte (mixed wastewater solution) level in the membraneless single-tank 9 drops to 1 / 5 of its initial height. The remaining liquid is collected in the hollow sealed tank 13 and discharged through the metal ion enrichment outlet at the bottom of the hollow sealed tank 13 for metal extraction. The extracted residual liquid and washing solution can be mixed and added to the next batch of industrial wastewater for subsequent recycling electrolysis. During subsequent recycling, electrolyte can also be added from the third inlet 16 on the oxygen evolution tank 10, and the electrolyte can be circulated in the membraneless single-tank electrolysis water production-electroplating wastewater enrichment coupling device by adjusting the corresponding water pump.

[0040] It should be understood that expressions such as “comprising” and “may include” used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as “comprising” and / or “having” are to be interpreted as indicating a particular characteristic, number, operation, constituent element, component, or combination thereof, but not to exclude the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0041] Furthermore, in this application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0042] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. "Fixed connection" refers to a connection where the relative positional relationship remains unchanged after connection. "Rotary connection" refers to a connection where the components can rotate relative to each other after connection. "Sliding connection" refers to a connection where the components can slide relative to each other after connection. The directional terms mentioned in the embodiments of this application, such as "top," "bottom," "inner," "outer," "left," and "right," are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of this application, and are not intended to indicate or imply that the device or component 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 the embodiments of this application.

[0043] Furthermore, the mathematical concepts mentioned in the embodiments of this application, such as symmetry, equality, parallelism, and perpendicularity, are limitations specific to the current technological level, rather than absolute and strict mathematical definitions. Slight deviations are permissible; approximations of symmetry, equality, parallelism, and perpendicularity are all acceptable. For example, "A and B are parallel" means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 and 10 degrees. "A and B are perpendicular" means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 80 and 100 degrees.

[0044] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A membrane-free single-tank electrolysis water production-electroplating wastewater enrichment coupling device, characterized in that, The system includes a membraneless single tank (9), an oxygen evolution tank (10), and a hollow sealed tank (13). The membraneless single tank (9) is a covered box with a cathode electrode (5) and an anode electrode (6) connected in series inside the box. The membraneless single tank (9), the oxygen evolution tank (10), and the hollow sealed tank (13) are connected in sequence to form a closed loop. The membraneless single tank (9) is used as a place for the electrolyte to be electrolyzed to produce hydrogen, and is also used to input the residual electrolyte into the oxygen evolution tank (10). The oxygen evolution tank (10) is used as a place for the oxygen evolution reaction, and is also used to input the residual reaction liquid after the oxygen evolution reaction into the hollow sealed tank (13). The hollow sealed tank (13) is used as a transfer place to input the residual reaction liquid into the membraneless single tank (9) to participate in the next round of electrolysis reaction.

2. The membrane-free single-tank electrolysis water production-electroplating wastewater enrichment coupling device as described in claim 1, characterized in that, The top cover of the membraneless single tank (9) is provided with a first hydrogen outlet (1) and an air outlet (2), and the upper part of its side wall is provided with a residual liquid inlet (31) and the lower part of its side wall is provided with a residual liquid outlet (32); the hollow sealed tank (13) is provided with a first liquid outlet (131) and a first liquid inlet (132); the oxygen evolution tank (10) is provided with a fourth liquid inlet (17) and a second liquid outlet (18), the residual liquid outlet (32) is connected to the fourth liquid inlet (17), the second liquid outlet (18) is connected to the first liquid inlet (132), and the residual liquid inlet (31) is connected to the first liquid outlet (131) to form a closed loop.

3. The membrane-free single-tank electrolysis water production-electroplating wastewater enrichment coupling device as described in claim 2, characterized in that, The lower part of the hollow sealed container (13) is also provided with a metal ion enrichment residual liquid outlet (15).

4. The membrane-free single-tank electrolysis water production-electroplating wastewater enrichment coupling device as described in claim 1, characterized in that, The membrane-free single tank (9) is equipped with a first heating device (81), which is located between the cathode electrode (5) and the anode electrode (6).

5. The membrane-free single-tank electrolysis water production-electroplating wastewater enrichment coupling device as described in claim 1, characterized in that, A magnetic stir bar (7) is provided at the bottom of the membraneless single tank (9), and the magnetic stir bar is located between the cathode electrode (5) and the anode electrode (6).

6. The membrane-free single-tank electrolysis water production-electroplating wastewater enrichment coupling device as described in claim 2, characterized in that, A first water pump (19) is provided between the first liquid outlet (131) and the residual liquid inlet (31); a second water pump (20) is provided between the first liquid inlet (132) and the second liquid outlet (18); and a third water pump (21) is provided between the fourth liquid inlet (17) and the residual liquid outlet (32).

7. The membrane-free single-tank electrolysis water production-electroplating wastewater enrichment coupling device as described in claim 1, characterized in that, The oxygen evolution tank (10) is equipped with a second heating device (82).

8. The membrane-free single-tank electrolysis water production-electroplating wastewater enrichment coupling device as described in claim 1, characterized in that, The oxygen evolution tank (10) is provided with an oxygen outlet (14) and a vacuum pump connection port (22) at the top.

9. The membrane-free single-tank electrolysis water production-electroplating wastewater enrichment coupling device as described in claim 1, characterized in that, The oxygen evolution tank (10) is equipped with an oxygen evolution catalyst (11), which is formed by multiple oxygen evolution catalyst plates connected in series.

10. The membrane-free single-tank electrolysis water production-electroplating wastewater enrichment coupling device as described in claim 1, characterized in that, The upper side wall of the membraneless single tank (9) is also provided with an electrolyte inlet (4).

Images