Cascade produced water electrolysis treatment device

Abstract

The invention relates to a stepped produced water electrolysis treatment device which comprises a softening system, one end of the softening system is provided with a liquid inlet assembly, one side of the softening system is connected with a diaphragm-free electrolytic bath, and the diaphragm-free electrolytic bath is relatively communicated with the softening system. An organic matter degradation hydrogen production assembly is arranged in the diaphragm-free electrolytic cell, a desalination value-added electrolytic cell is arranged on one side of the diaphragm-free electrolytic cell, the desalination value-added electrolytic cell is relatively communicated with the diaphragm-free electrolytic cell, and a desalination assembly is arranged in the desalination value-added electrolytic cell. According to the invention, pollution reduction and desalination of the produced water are synchronously realized by constructing the diaphragm-free electrolytic tank and the desalination tank which are electrochemically driven, and the effect of integrated decontamination and resource utilization of the produced water is realized.

Description

Technical Field

[0001] The present application relates to the field of oil and gas extraction equipment, and in particular to a device for electrolyzing and treating cascaded produced water. Background Art

[0002] In the current context, fossil resources will return to their resource nature, reducing their use in the energy sector. With the large-scale application of renewable energy sources such as wind, solar, and nuclear energy, the cost of renewable electricity will continue to decline. The future petrochemical industry will achieve electrification of energy supply and drive, and renewable electricity will become the primary energy input for the industry.

[0003] The oil and gas extraction process generates a large amount of produced water. This water contains a large number of pollutants, and direct discharge would cause huge environmental problems. Therefore, it must be treated to meet the standards before it can be discharged.

[0004] However, the current produced water treatment process is complex, consumes numerous treatment reagents, and is costly. Electrochemical oxidation technology offers a new approach to produced water treatment. By directly electrolyzing produced water and utilizing the highly oxidizing species generated during the electrolysis process to oxidize pollutants, it is possible to achieve integrated produced water pollution reduction and hydrogen production. Furthermore, produced water often contains high levels of salt, requiring further desalination before discharge. This desalination step can also be accomplished using electrochemical systems. Summary of the Invention

[0005] In order to simultaneously achieve pollution reduction and desalination of produced water by constructing an electrochemically driven diaphragmless electrolytic cell and a desalination cell, and realize integrated produced water decontamination and resource utilization, the present application provides a cascaded produced water electrolysis treatment device.

[0006] This application provides a cascade produced water electrolysis treatment device, which adopts the following technical solution:

[0007] A cascade produced water electrolysis treatment device includes a softening system, one end of the softening system is provided with a liquid inlet component, one side of the softening system is connected to a diaphragmless electrolytic cell, the diaphragmless electrolytic cell is relatively communicated with the softening system, an organic matter degradation and hydrogen production component is provided inside the diaphragmless electrolytic cell, a desalination and value-added electrolytic cell is provided on one side of the diaphragmless electrolytic cell, the desalination and value-added electrolytic cell is relatively communicated with the diaphragmless electrolytic cell, and a desalination component is provided inside the desalination and value-added electrolytic cell.

[0008] Optionally, the membraneless electrolyzer includes a membraneless electrolyzer body, a first water inlet is provided on the side of the membraneless electrolyzer body close to the softening system, a first water outlet is provided on the side of the membraneless electrolyzer body close to the desalination value-added electrolyzer, and a first hydrogen gas outlet is provided on the top wall of the membraneless electrolyzer body.

[0009] Optionally, the organic matter degradation and hydrogen production component includes a first anode and a first cathode arranged opposite to each other, the first anode and the first cathode are located inside the membraneless electrolyzer, and the interior of the membraneless electrolyzer is divided into an intermediate chamber between the first anode and the first cathode, an organic matter degradation chamber located on the side of the first anode away from the first cathode, and a hydrogen production chamber located on the side of the first cathode away from the first anode by the first anode and the first cathode, and the first hydrogen gas outlet is located at a position opposite to the membraneless electrolyzer and the hydrogen production chamber.

[0010] Optionally, the first anode is a boron-doped diamond electrode.

[0011] Optionally, the first anode is an oxide-loaded titanium electrode.

[0012] Optionally, the first cathode may be a Raney nickel electrode.

[0013] Optionally, the first cathode may be a foam nickel electrode.

[0014] Optionally, the first cathode may be a nickel foam electrode having a coating of non-metallic oxide, sulfide and phosphide.

[0015] Optionally, the oxide loading of the first anode may be Ir, Ru, Sn, Pb, Ta and Ti elements.

[0016] Optionally, the non-metal oxide coating of the first cathode may contain Ni, Co and Fe elements.

[0017] Optionally, the desalination value-added electrolytic cell includes a desalination value-added electrolytic cell body, the desalination component is located inside the desalination value-added electrolytic cell body, a circulating liquid inlet component is provided at the bottom end of the desalination value-added electrolytic cell body, a circulating liquid outlet component is provided on the side wall of the desalination value-added electrolytic cell body, and a circulation pipe is provided between the desalination value-added electrolytic cell and the softening system, and the circulation pipe relatively connects the interior of the desalination component with the interior of the softening component.

[0018] Optionally, the desalination component includes a second anode located inside the desalination value-added electrolytic cell, a first bipolar membrane is provided on one side of the second anode, an anion exchange membrane is provided on the side of the first bipolar membrane facing away from the second anode, a cation exchange membrane is provided on the side of the anion exchange membrane facing away from the first bipolar membrane, a second bipolar membrane is provided on the side of the cation exchange membrane facing away from the anion exchange membrane, and a second cathode is provided on the side of the second bipolar membrane facing away from the cation exchange membrane.

[0019] Optionally, a first chamber is formed between the second anode and the first bipolar membrane, a second chamber is formed between the first bipolar membrane and the anion exchange membrane, a third chamber is formed between the anion exchange membrane and the cation exchange membrane, a fourth chamber is formed between the cation exchange membrane and the second bipolar membrane, and a fifth chamber is formed between the second bipolar membrane and the second cathode.

[0020] Optionally, the circulating liquid inlet component includes a first liquid inlet arranged at the position of the first chamber, the first liquid inlet is relatively connected to the interior of the first chamber, the desalination value-added electrolytic cell is provided with a second liquid inlet relative to the second chamber, the second liquid inlet is relatively connected to the interior of the second chamber, the desalination value-added electrolytic cell is provided with a third liquid inlet relative to the third chamber, the third liquid inlet is relatively connected to the third chamber, the desalination value-added electrolytic cell is provided with a fourth liquid inlet relative to the fourth chamber, the fourth liquid inlet is relatively connected to the fourth chamber, the desalination value-added electrolytic cell is provided with a fifth liquid inlet relative to the fifth chamber, the fifth liquid inlet is relatively connected to the fifth chamber.

[0021] Optionally, the circulating liquid outlet component includes a first liquid outlet arranged at the position of the first chamber, the first liquid outlet is relatively connected to the interior of the first chamber, the desalination value-added electrolytic cell is provided with a second liquid outlet relative to the second chamber, the second liquid outlet is relatively connected to the interior of the second chamber, the desalination value-added electrolytic cell is provided with a third liquid outlet relative to the third chamber, the third liquid outlet is relatively connected to the third chamber, the desalination value-added electrolytic cell is provided with a fourth liquid outlet relative to the fourth chamber, the fourth liquid outlet is relatively connected to the fourth chamber, the desalination value-added electrolytic cell is provided with a fifth liquid outlet relative to the fifth chamber, the fifth liquid outlet is relatively connected to the fifth chamber.

[0022] Optionally, the first liquid inlet circulates and supplies a KOH solution with a concentration of 1 mol / L, the second liquid inlet circulates and supplies an HCL solution, the third liquid inlet is relatively connected to the liquid outlet of the desalination value-added electrolytic cell and is used to circulate and supply a NaCl solution, the fourth liquid inlet circulates and supplies a NaOH solution, and the fifth liquid inlet circulates and supplies a 0.5 mol / L H2SO4 solution.

[0023] Optionally, one end of the circulation pipeline is relatively connected to the fourth liquid outlet of the desalination and value-added electrolytic cell, and the other end of the circulation pipeline is relatively connected to the softening system.

[0024] Optionally, the desalination value-added electrolytic cell is fixedly connected to a second hydrogen gas outlet at a position relative to the fifth chamber.

[0025] Optionally, the desalination value-added electrolytic cell is fixedly connected to a low-salt water discharge pipe at a position relative to the third chamber.

[0026] Optionally, a hydrochloric acid discharge pipe is fixedly connected to the position of the desalination and value-added electrolytic cell relative to the second chamber.

[0027] In summary, this application includes at least one of the following beneficial technical effects:

[0028] The produced water from the oil field enters the softening system from the liquid inlet component. The produced water from the oil field in the softening system is mixed with the sodium hydroxide in the desalination value-added electrolytic cell. The Ca in the produced water is 2+ and Mg 2+ The plasma flocculates and precipitates under the action of alkali, and then is separated after filtration. The separated produced water enters the interior of the non-diaphragm electrolytic cell. Under the action of the first anode and the first cathode, the produced water pollution reduction and hydrogen production are integrated. The produced water inside the non-diaphragm electrolytic cell can undergo direct oxidation and degradation of organic pollutants, chlorine evolution reaction and oxygen evolution reaction on the side of the first anode. The chlorine produced by the chlorine evolution reaction reacts in situ with the hydroxide produced on the cathode side to produce ClO - , the oxygen evolution reaction can also generate strong oxidizing species such as OH·, which can further indirectly oxidize and degrade organic matter; the produced water inside the membraneless electrolyzer undergoes hydrogen evolution reaction on one side of the first cathode, and the generated hydrogen is collected; the produced water inside the membraneless electrolyzer enters the desalination value-added electrolyzer after treatment, and its Cl is driven by an external voltage in the third chamber. - Cross the anion exchange membrane into the second chamber, while Na + It crosses the cation exchange membrane and enters the fourth chamber to achieve the effect of desalination. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall process of a cascade produced water electrolysis treatment device in an embodiment of the present application.

[0030] Figure 2 It is a structural schematic diagram of a diaphragm-free electrolytic cell of a stepped produced water electrolysis treatment device in an embodiment of the present application.

[0031] Figure 3 It is a structural schematic diagram of a desalination and value-added electrolytic cell of a cascade produced water electrolysis treatment device in an embodiment of the present application.

[0032] Explanation of the accompanying symbols: 1. Softening system; 2. Membraneless electrolytic cell; 21. First water inlet; 22. First water outlet; 23. First anode; 24. First cathode; 25. Intermediate chamber; 26. Organic matter degradation chamber; 27. Hydrogen production chamber; 28. First hydrogen gas outlet; 3. Desalination and value-added electrolytic cell; 31. Deoxidation component; 311. Second anode; 312. First bipolar membrane; 313. Anion exchange membrane; 314. Cation exchange membrane; 315. Second bipolar membrane; 316. Second cathode; 32. First chamber; 33. Second chamber; 34. Third chamber; 35. Fourth chamber; 36. Fifth chamber; 4. Circulation pipeline. DETAILED DESCRIPTION

[0033] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other.

[0034] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0035] Against the backdrop of carbon peak and carbon neutrality, fossil resources will return to their resource nature, reducing their use in the energy sector. With the large-scale application of renewable energy sources such as wind, solar, and nuclear energy, the cost of renewable electricity will continue to decline. The future petrochemical industry will achieve electrification of energy supply and drive, and renewable electricity will become the primary energy input for the industry.

[0036] The oil and gas extraction process generates a large amount of produced water. This water contains a large number of pollutants, and direct discharge would cause huge environmental problems. Therefore, it must be treated to meet the standards before it can be discharged.

[0037] However, the current produced water treatment process is complex, consumes numerous treatment reagents, and is costly. Electrochemical oxidation technology offers a new approach to produced water treatment. By directly electrolyzing produced water and utilizing the highly oxidizing species generated during the electrolysis process to oxidize pollutants, it is possible to achieve integrated produced water pollution reduction and hydrogen production. Furthermore, produced water often contains high levels of salt, requiring further desalination before discharge. This desalination step can also be accomplished using electrochemical systems.

[0038] In order to simultaneously achieve pollution reduction and desalination of produced water by constructing an electrochemically driven diaphragm-free electrolyzer and desalination tank, integrated produced water decontamination and resource utilization are realized.

[0039] The following is combined with Figure 1-3 This application is described in further detail.

[0040] The present application discloses a device for electrolyzing and treating cascaded produced water. Figure 1 、 Figure 2 A cascaded produced water electrolysis treatment device includes a softening system 1. A liquid inlet component is provided on one side of the softening system 1. The liquid inlet component injects the produced water from the oil field into the interior of the softening system 1 for treatment. A diaphragmless electrolytic cell 2 is provided on one side of the softening system 1. By injecting the liquid treated by the softening system 1 into the interior of the diaphragmless electrolytic cell 2, the liquid is electrolyzed in the interior of the diaphragmless electrolytic cell 2 to realize the integrated production of produced water and hydrogen. A desalination and value-added electrolytic cell 3 is provided on one side of the diaphragmless electrolytic cell 2. The liquid treated by the diaphragmless electrolytic cell 2 can be injected into the interior of the desalination and value-added electrolytic cell 3, and desalination and value-added are carried out in the interior of the desalination and value-added electrolytic cell 3, thereby carrying out an integrated process of salt water desalination, acid-base regeneration and hydrogen production. A circulation pipe 4 is provided between the softening system 1 and the desalination and value-added electrolytic cell 3 , through which the sodium hydroxide examined in the desalination and value-added electrolytic cell 3 can flow back into the softening system 1 for flocculation and precipitation in the softening system 1 .

[0041] The liquid inlet assembly includes a liquid inlet pipe for circulating oilfield produced water. The liquid inlet pipe is fixedly connected to the softening system 1 and relatively communicated with each other, so that the produced water from the external oilfield is injected into the softening system 1 through the liquid inlet pipe for treatment.

[0042] The produced water from the external oil field is mixed with sodium hydroxide in the softening system 1. The Ca 2+ and Mg 2+ The plasma is flocculated and precipitated under the action of the alkali, thereby forming calcium hydroxide and magnesium hydroxide for precipitation. The precipitated calcium hydroxide and magnesium hydroxide are filtered inside the softening system 1, and then the filtered calcium hydroxide and magnesium hydroxide are filtered and discharged to the outside.

[0043] The membraneless electrolytic cell 2 includes a membraneless electrolytic cell body. A first water inlet 21 is provided on the side wall of the membraneless electrolytic cell body. The first water inlet 21 relatively connects the outside with the inside of the membraneless electrolytic cell body. A first water outlet 22 is also provided on the side wall of the membraneless electrolytic cell 2. The first water outlet 22 relatively connects the inside of the membraneless electrolytic cell 2 with the outside.

[0044] A first connecting pipe is provided between the membraneless electrolytic cell body and the softening system 1. The first connecting pipe is relatively connected to the first water inlet 21 of the membraneless electrolytic cell body, and the end of the first connecting pipe facing away from the membraneless electrolytic cell 2 is relatively connected to the softening system 1, so that the softening system 1 and the membraneless electrolytic cell body are relatively connected through the first connecting pipe, and the liquid after sedimentation and filtration in the softening system 1 can enter the interior of the membraneless electrolytic cell body.

[0045] A first anode 23 is vertically arranged inside the body of the membraneless electrolyzer, and a first cathode 24 is arranged on one side of the first anode 23. The first cathode 24 is vertically arranged, and the first anode 23 is fixedly connected to the body of the membraneless electrolyzer, and the first cathode 24 is fixedly connected to the body of the membraneless electrolyzer.

[0046] The first anode 23 may be a titanium electrode loaded with oxides of elements such as Ir, Ru, Sn, Pb, Ta, and Ti, or a boron-doped diamond electrode. The first cathode 24 may be a Raney nickel electrode, a foamed nickel electrode, or a foamed nickel electrode coated with oxides, sulfides, and phosphides of non-precious metals such as Ni, Co, and Fe.

[0047] The space inside the membraneless electrolyzer body is divided into three parts by the first cathode 24 and the first anode 23 located inside the membraneless electrolyzer body, including an intermediate chamber 25 located between the first cathode 24 and the first anode 23, an organic matter degradation chamber 26 located on the side of the first anode 23 away from the first cathode 24, and a hydrogen production chamber 27 on the side of the first cathode 24 away from the first anode 23.

[0048] In the organic matter degradation chamber, the first anode 23 can undergo direct oxidation degradation of organic pollutants, chlorine evolution reaction and oxygen evolution reaction, wherein the chlorine gas generated by the chlorine evolution reaction reacts with the hydroxide generated at the first cathode 24 to produce ClO - At the same time, the oxygen evolution reaction can also generate strong oxidizing species such as OH·, which can further indirectly oxidize and degrade organic matter.

[0049] A first hydrogen gas outlet 28 is provided on the top wall of the membraneless electrolyzer body at a position relative to the hydrogen production chamber 27. The first hydrogen gas outlet 28 connects the interior of the hydrogen production chamber 27 with the outside world, thereby facilitating the operator to collect the hydrogen generated inside the hydrogen production chamber 27.

[0050] Reference Figure 1 、 Figure 3 The desalination and value-added electrolytic cell 3 includes a desalination and value-added electrolytic cell body, within which a deoxidation assembly 31 is disposed. The desalination assembly includes a second anode 311 located within the desalination and value-added electrolytic cell body. The second anode 311 is vertically disposed and fixedly connected to the desalination and value-added electrolytic cell body. The second anode 311 is located on one side of the desalination and value-added electrolytic cell body. A first bipolar membrane 312 is disposed on a side of the second anode 311 near the center of the desalination and value-added electrolytic cell body. The first bipolar membrane 312 is vertically disposed and fixedly connected to the desalination and value-added electrolytic cell body. An anion exchange membrane 313 is disposed on the side of the first bipolar membrane 312 facing away from the second anode 311. The anion exchange membrane 313 is vertically disposed and fixedly connected to the side wall of the desalination and value-added electrolytic cell body. A cation exchange membrane 314 is provided on the side of the anion exchange membrane 313 facing away from the first bipolar membrane 312. The cation exchange membrane 314 is vertically arranged and fixedly connected to the desalination value-added electrolytic cell body. A second bipolar membrane 315 is provided on the side of the cation exchange membrane 314 facing away from the anion exchange membrane 313. The second bipolar membrane 315 is vertically arranged and fixedly connected to the desalination value-added electrolytic cell body. A second cathode 316 is provided on the side of the second bipolar membrane 315 facing away from the cation exchange membrane 314. The second cathode 316 is vertically arranged and located on the side of the desalination value-added electrolytic cell body facing away from the second anode 311. The second cathode 316 is fixedly connected to the desalination value-added electrolytic cell body.

[0051] The interior of the desalination value-added electrolytic cell body is divided into five chambers by the second cathode 316, the first bipolar membrane 312, the anion exchange membrane 313, the cation exchange membrane 314, the second bipolar membrane 315 and the second anode 311, which are respectively the first chamber 32 located between the second cathode 316 and the first bipolar membrane 312, the second chamber 33 between the first bipolar membrane 312 and the anion exchange membrane 313, the third chamber 34 between the anion exchange membrane 313 and the cation exchange membrane 314, the fourth chamber 35 between the cation exchange membrane 314 and the second bipolar membrane 315, and the fifth chamber 36 between the second bipolar membrane 315 and the second anode 311.

[0052] The first chamber 32 and the second chamber 33 are connected by the first bipolar membrane 312, the second chamber 33 and the third chamber 34 are connected by the anion exchange membrane 313 so that anions can be relatively connected, the third chamber 34 and the fourth chamber 35 are connected by the cation exchange membrane 314 so that cations can be relatively connected, and the fourth chamber 35 and the fifth chamber 36 are relatively connected by the second bipolar membrane 315.

[0053] A circulating liquid inlet assembly is provided at the bottom end of the desalination value-added electrolytic cell body, and a circulating liquid outlet assembly is provided at the top end of the desalination value-added electrolytic cell body. The circulating liquid inlet assembly is relatively connected to the interior of the desalination value-added electrolytic cell body, and the circulating liquid outlet assembly is relatively connected to the interior of the desalination value-added electrolytic cell body, and the circulating liquid inlet assembly and the circulating liquid outlet assembly are respectively connected one by one through pipelines.

[0054] The circulating liquid inlet assembly includes a first liquid inlet located on the bottom wall of the desalination value-added electrolytic cell body, and the first liquid inlet is in relative communication with the first chamber 32 of the desalination value-added electrolytic cell body. A second liquid inlet is provided on the bottom wall of the desalination value-added electrolytic cell body, and the second liquid inlet is in relative communication with the second chamber 33 of the desalination value-added electrolytic cell body. A third liquid inlet is provided on the bottom wall of the desalination value-added electrolytic cell body, and the third liquid inlet is in relative communication with the third chamber 34 of the desalination value-added electrolytic cell body. A fourth liquid inlet is provided on the bottom wall of the desalination value-added electrolytic cell body, and the fourth liquid inlet is in relative communication with the fourth chamber 35 of the desalination value-added electrolytic cell body. A fifth liquid inlet is provided on the bottom wall of the desalination value-added electrolytic cell 3, and the fifth liquid inlet is in relative communication with the fifth chamber 36 of the desalination value-added electrolytic cell body.

[0055] The circulating liquid outlet assembly includes a first liquid outlet located on the top wall of the desalination value-added electrolytic cell body, the first liquid outlet being in relative communication with the first chamber 32 of the desalination value-added electrolytic cell body. A second liquid outlet is provided on the top wall of the desalination value-added electrolytic cell body, the second liquid outlet being in relative communication with the second chamber 33 of the desalination value-added electrolytic cell body. A third liquid outlet is provided on the top wall of the desalination value-added electrolytic cell body, the third liquid outlet being in relative communication with the third chamber 34 of the desalination value-added electrolytic cell body. A fourth liquid outlet is provided on the top wall of the desalination value-added electrolytic cell body, the fourth liquid outlet being in relative communication with the fourth chamber 35 of the desalination value-added electrolytic cell body. A fifth liquid outlet is provided on the top wall of the desalination value-added electrolytic cell 3, the fifth liquid outlet being in relative communication with the fifth chamber 36 of the desalination value-added electrolytic cell body.

[0056] KOH with a concentration of 1 mol / L is circulated and supplied in a pipe connected to the first liquid inlet and the first liquid outlet, so that the interior of the first chamber 32 is filled with a KOH solution with a concentration of 1 mol / L.

[0057] The HCl solution is circulated in the pipes connected to the second liquid inlet and the second liquid outlet, so that the interior of the second chamber 33 is filled with the HCl solution.

[0058] Produced water containing NaCl from the membraneless electrolytic cell 2 is circulated in a pipeline relatively connected to the third liquid inlet and the third liquid outlet, so that the interior of the third chamber 34 is filled with produced water containing NaCl.

[0059] The NaOH solution is circulated in the pipelines connected to the fourth liquid inlet and the fourth liquid outlet, so that the interior of the fourth chamber 35 is filled with the NaOH solution.

[0060] A 0.5 mol / L H 2 SO 4 solution is circulated in the pipelines connected to the fifth liquid inlet and the fifth liquid outlet, so that the interior of the fifth chamber 36 is filled with the H 2 SO 4 solution.

[0061] For the produced water containing NaCl entering the third chamber 34, under the driving of external voltage, the Cl - Crossing the anion exchange membrane 313 into the interior of the second chamber 33, Na + The produced water passes through the cation exchange membrane 314 and enters the interior of the fourth chamber 35 , achieving the effect of desalination of the produced water in the third chamber 34 .

[0062] A hydrochloric acid discharge pipe is provided on the side wall of the desalination value-added electrolytic cell body relative to the second chamber 33 . The hydrochloric acid discharge pipe is relatively connected to the interior of the second chamber 33 , thereby facilitating the discharge of hydrochloric acid inside the second chamber 33 .

[0063] A low-salt water discharge pipe is provided on the side wall of the desalination value-added electrolytic cell body relative to the third chamber 34. One end of the low-salt water discharge pipe is relatively connected to the interior of the third chamber 34, and the other end of the low-salt water discharge pipe is relatively connected to the external subsequent processing device, thereby facilitating the discharge of the low-salt water located inside the third chamber 34.

[0064] A circulation pipe 4 is provided on the side wall of the desalination value-added electrolytic cell body relative to the fourth chamber 35. One end of the circulation pipe 4 is relatively connected to the fourth chamber 35, and the other end of the circulation pipe 4 is relatively connected to the softening system 1, so that the formed NaOH solution can be injected into the interior of the softening system 1 to remove the Ca in the produced water. 2+ and Mg 2+ The plasma undergoes flocculation and precipitation under the action of alkali, thereby forming calcium hydroxide and magnesium hydroxide precipitates.

[0065] A second hydrogen gas outlet is provided on the top wall of the desalination value-added electrolytic cell body at a position relative to the fifth chamber 36. The second hydrogen gas outlet is relatively connected to the interior of the fifth chamber 36, and the hydrogen inside the fifth chamber 36 is collected and processed through the second hydrogen gas outlet. In the present invention, the term "plurality" refers to at least two or at least two or more, unless otherwise clearly defined. Terms such as "installation", "connection", "connection", and "fixed" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "connection" can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0066] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Claims

1. A cascade produced water electrolysis treatment device, characterized by: The invention comprises a softening system (1), wherein one end of the softening system (1) is provided with a liquid inlet component, one side of the softening system (1) is connected to a non-diaphragm electrolytic cell (2), the non-diaphragm electrolytic cell (2) is relatively communicated with the softening system (1), an organic matter degradation hydrogen production component is provided inside the non-diaphragm electrolytic cell (2), a desalination value-added electrolytic cell (3) is provided on one side of the non-diaphragm electrolytic cell (2), the desalination value-added electrolytic cell (3) is relatively communicated with the non-diaphragm electrolytic cell (2), and a desalination component is provided inside the desalination value-added electrolytic cell (3).

2. The electrolytic treatment device for cascaded produced water according to claim 1, characterized in that: The membrane-less electrolytic cell (2) includes a membrane-less electrolytic cell body, a first water inlet (21) is provided on a side of the membrane-less electrolytic cell body close to the softening system (1), a first water outlet (22) is provided on a side of the membrane-less electrolytic cell body close to the desalination and value-added electrolytic cell (3), and a first hydrogen gas outlet (28) is provided on the top wall of the membrane-less electrolytic cell body.

3. The electrolytic treatment device for cascaded produced water according to claim 2, characterized in that: The organic matter degradation hydrogen production component comprises a first anode (23) and a first cathode (24) arranged opposite to each other, wherein the first anode (23) and the first cathode (24) are located inside the membraneless electrolyzer (2), and the interior of the membraneless electrolyzer (2) is divided into an intermediate chamber (25) located between the first anode (23) and the first cathode (24), an organic matter degradation chamber (26) located on the side of the first anode (23) away from the first cathode (24), and a hydrogen production chamber (27) located on the side of the first cathode (24) away from the first anode (23), and the first hydrogen gas outlet (28) is located at a position of the membraneless electrolyzer (2) opposite to the hydrogen production chamber (27).

4. The electrolytic treatment device for cascaded produced water according to claim 3, characterized in that: The first anode (23) is a boron-doped diamond electrode.

5. The electrolytic treatment device for cascaded produced water according to claim 3, characterized in that: The first anode (23) is an oxide-loaded titanium electrode.

6. The electrolytic treatment device for cascaded produced water according to claim 3, characterized in that: The first cathode (24) may be a Raney nickel electrode.

7. The electrolytic treatment device for cascaded produced water according to claim 3, characterized in that: The first cathode (24) may be a foam nickel electrode.

8. The electrolytic treatment device for cascaded produced water according to claim 3, characterized in that: The first cathode (24) may be a nickel foam electrode having a non-metallic oxide, sulfide and phosphide coating.

9. The electrolytic treatment device for cascaded produced water according to claim 5, characterized in that: The oxide loading of the first anode (23) may be Ir, Ru, Sn, Pb, Ta and Ti elements.

10. The electrolytic treatment device for cascaded produced water according to claim 8, characterized in that: The non-metal oxide coating of the first cathode (24) may contain Ni, Co and Fe elements.

11. The electrolytic treatment device for cascaded produced water according to claim 1, characterized in that: The desalination and value-added electrolytic cell (3) comprises a desalination and value-added electrolytic cell body, the desalination component is located inside the desalination and value-added electrolytic cell body, a circulating liquid inlet component is provided at the bottom end of the desalination and value-added electrolytic cell body, a circulating liquid outlet component is provided on the side wall of the desalination and value-added electrolytic cell body, a circulating pipe (4) is provided between the desalination and value-added electrolytic cell (3) and the softening system (1), and the circulating pipe (4) relatively connects the interior of the desalination component with the interior of the softening component.

12. The electrolytic treatment device for cascaded produced water according to claim 11, characterized in that: The desalination component comprises a second anode (311) located inside the desalination value-added electrolytic cell (3); a first bipolar membrane (312) is provided on one side of the second anode (311); an anion exchange membrane (313) is provided on the side of the first bipolar membrane (312) facing away from the second anode (311); a cation exchange membrane (314) is provided on the side of the anion exchange membrane (313) facing away from the first bipolar membrane (312); a second bipolar membrane (315) is provided on the side of the cation exchange membrane (314) facing away from the anion exchange membrane (313); and a second cathode (316) is provided on the side of the second bipolar membrane (315) facing away from the cation exchange membrane (314).

13. The electrolytic treatment device for cascaded produced water according to claim 12, characterized in that: A first chamber (32) is formed between the second anode (311) and the first bipolar membrane (312), a second chamber (33) is formed between the first bipolar membrane (312) and the anion exchange membrane (313), a third chamber (34) is formed between the anion exchange membrane (313) and the cation exchange membrane (314), a fourth chamber (35) is formed between the cation exchange membrane (314) and the second bipolar membrane (315), and a fifth chamber (36) is formed between the second bipolar membrane (315) and the second cathode (316).

14. The electrolytic treatment device for cascaded produced water according to claim 13, characterized in that: The circulating liquid inlet assembly includes a first liquid inlet provided at the position of the first chamber (32), the first liquid inlet being relatively connected to the interior of the first chamber (32), the desalination value-added electrolytic cell (3) being provided with a second liquid inlet relative to the second chamber (33), the second liquid inlet being relatively connected to the interior of the second chamber (33), the desalination value-added electrolytic cell (3) being provided with a third liquid inlet relative to the third chamber (34), the third liquid inlet being relatively connected to the third chamber (34), the desalination value-added electrolytic cell (3) being provided with a fourth liquid inlet relative to the fourth chamber (35), the fourth liquid inlet being relatively connected to the fourth chamber (35), and the desalination value-added electrolytic cell (3) being provided with a fifth liquid inlet relative to the fifth chamber (36), the fifth liquid inlet being relatively connected to the fifth chamber (36).

15. The electrolytic treatment device for cascaded produced water according to claim 13, characterized in that: The circulating liquid outlet component includes a first liquid outlet arranged at the position of the first chamber (32), the first liquid outlet being relatively connected to the interior of the first chamber (32), the desalination value-added electrolytic cell (3) being provided with a second liquid outlet relative to the second chamber (33), the second liquid outlet being relatively connected to the interior of the second chamber (33), the desalination value-added electrolytic cell (3) being provided with a third liquid outlet relative to the third chamber (34), the third liquid outlet being relatively connected to the third chamber (34), the desalination value-added electrolytic cell (3) being provided with a fourth liquid outlet relative to the fourth chamber (35), the fourth liquid outlet being relatively connected to the fourth chamber (35), and the desalination value-added electrolytic cell (3) being provided with a fifth liquid outlet relative to the fifth chamber (36), the fifth liquid outlet being relatively connected to the fifth chamber (36).

16. The device for electrolyzing cascaded produced water according to any one of claims 11 to 15, characterized in that: The first liquid inlet is used to circulate and supply a KOH solution with a concentration of 1 mol / L, the second liquid inlet is used to circulate and supply an HCL solution, the third liquid inlet is relatively connected to the liquid outlet of the desalination value-added electrolytic cell (3) and is used to circulate and supply a NaCl solution, the fourth liquid inlet is used to circulate and supply a NaOH solution, and the fifth liquid inlet is used to circulate and supply a 0.5 mol / L H2SO4 solution.

17. The electrolytic treatment device for cascaded produced water according to claim 16, characterized in that: One end of the circulation pipe (4) is relatively connected to the fourth liquid outlet of the desalination and value-added electrolytic cell (3), and the other end of the circulation pipe (4) is relatively connected to the softening system (1).

18. The electrolytic treatment device for cascaded produced water according to claim 16, characterized in that: The desalination value-added electrolytic cell (3) is fixedly connected to a second hydrogen gas outlet at a position relative to the fifth chamber (36).

19. The electrolytic treatment device for cascaded produced water according to claim 16, characterized in that: The desalination and value-added electrolytic cell (3) is fixedly connected to a low-salt water discharge pipe at a position relative to the third chamber (34).

20. The electrolytic treatment device for cascaded produced water according to claim 16, characterized in that: The desalination and value-added electrolytic cell (3) is fixedly connected to a hydrochloric acid discharge pipe at a position relative to the second chamber (33).

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