SOEC electrolytic oilfield sewage hydrogen production system and method

Abstract

The invention discloses a system and a method for hydrogen production by SOEC electrolysis of oilfield sewage, and belongs to the technical field of sewage environmental protection. According to the system disclosed by the invention, the SOEC electrolytic tank is arranged, so that electrolytic products of SOEC are fully utilized, products obtained in the treatment process are useful resources such as hydrogen and oxygen, high-purity oxygen can be used for oxidation treatment of oilfield sewage, and hydrogen can be used as a clean and efficient energy source, so that recycling of oilfield sewage is realized; and meanwhile, the high-temperature characteristic of SOEC electrolysis is utilized, the generated high-temperature gas is subjected to heat regeneration utilization through the waste heat utilization module, the energy utilization rate is greatly increased, and input energy needed by the system is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage environmental protection, and specifically relates to a SOEC electrolysis oilfield sewage hydrogen production system and method. Background Art

[0002] As the water content of crude oil produced by oil fields is generally above 80%, a large amount of oilfield wastewater is generated. The pollutants in oilfield wastewater mainly include COD, TDS, suspended solids, ammonia nitrogen, calcium and magnesium ions, chloride ions, sulfates, fluorides, sulfides, and organic matter. The output of oilfield wastewater is huge and the distribution area is wide. If it is directly discharged without treatment, it will have a huge impact on the soil, water sources, air, and people's life safety, and cause huge losses to the national economy.

[0003] At present, the commonly used methods for treating oilfield wastewater can be mainly divided into physical methods, chemical methods, and biological methods. Physical treatment methods refer to methods of separating and removing suspended solids insoluble in water from oilfield wastewater through physical action. Physical methods mainly include natural separation method, membrane separation method, etc., chemical methods include flocculation method, electro-desorption technology, etc., and biological methods include biofilm method, activated sludge method, etc. Due to the diversity of oilfield wastewater pollution, multiple methods are often required to be used in combination in actual treatment. Common primary treatments include natural separation, centrifugation, and flotation, which preliminarily treat wet solids and floating oil; secondary treatments include chemical treatment, filtration, etc., which remove dispersed oil and demulsification; deep treatments include adsorption, ultrafiltration, etc., and dissolved oil in wastewater is treated in this step. Although traditional processes for treating oilfield wastewater are effective to a certain extent, they have many disadvantages. Traditional oilfield wastewater treatment processes require a lot of energy and are costly. Traditional wastewater treatment processes usually require a lot of energy, such as electricity and heat energy, to drive sewage pumps, agitators, and aeration equipment, etc. Microorganisms in bioreactors need to consume a lot of oxygen, resulting in increased energy consumption. High operating costs may put pressure on the financial situation of the company and affect its long-term sustainable operation. At the same time, the wastewater treated by the traditional oilfield wastewater treatment process can only be injected back into the ground, and it is difficult to realize resource utilization of the products in the wastewater treatment process, and it is impossible to achieve waste resource utilization. In addition, the traditional oilfield wastewater treatment process requires a large amount of chemical and biological agents, which may cause secondary pollution to the environment.

[0004] Solid oxide electrolysis cell (SOEC) is mainly used for processes such as electrolysis of water to produce hydrogen or reduction of carbon dioxide, and is an efficient electrolysis technology. SOEC usually works at high temperature (700℃-1000℃), which can significantly reduce the electrolysis voltage. At the same time, due to the more favorable reaction kinetics under high temperature conditions, the electrolysis efficiency of SOEC is higher than that of traditional low-temperature electrolysis cells, which improves the electrolysis efficiency. Due to the high-temperature working characteristics of SOEC, the temperature of the produced gas is very high, and the waste heat can also be fully utilized. Hydrogen generated by SOEC electrolysis of water vapor can bring some economic benefits as a clean energy source. In addition to hydrogen, SOEC also has high-purity oxygen in the products generated by electrolysis, which can be supplied to the aeration tank. At the same time, SOEC is composed of all solids and has high safety. The electrolyte will not leak or volatilize. In cold areas, the performance will not drop significantly due to low temperature, and the service life is also longer.

[0005] The Chinese patent application with publication number CN117700047A discloses a system and method for producing hydrogen by electrolysis of sewage. However, the electrolyte of this system is composed of potassium chloride solution, which has a low freezing point. Since a large number of oil fields are concentrated in the north, the temperature in winter is often below zero, which makes it difficult to meet the needs of oil fields throughout the year. The oxygen produced in the Chinese patent application with publication number CN117700047A is not effectively utilized.

[0006] Therefore, there is a need for a SOEC electrolysis oilfield wastewater system that does not require any harmful materials, can effectively utilize the waste heat carried in the SOEC production gas, maximize the energy utilization efficiency in the oilfield wastewater recovery process, and can effectively integrate hydrogen and oxygen production systems to convert oilfield wastewater into clean and efficient energy hydrogen, and use the produced oxygen to oxidize and treat oilfield wastewater, with high efficiency and low cost. Summary of the invention

[0007] The object of the present invention is to provide a SOEC electrolysis oilfield wastewater hydrogen production system and method, which is used to solve the technical problem of low energy utilization efficiency in the wastewater recovery process in the existing electrolysis hydrogen production system.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions: The invention discloses a SOEC electrolysis oilfield sewage hydrogen production system, comprising a sewage treatment module, a waste heat utilization module, a SOEC electrolytic cell and an oxygen storage tank; the sewage treatment module is connected to sewage and air; the output end of the sewage treatment module is connected to the input end of the waste heat utilization module and the oxygen storage tank; the output end of the SOEC electrolytic cell is connected to the input end of the waste heat utilization module; The output end of the waste heat utilization module is connected to the input end of the sewage treatment module and the input end of the SOEC electrolytic cell.

[0009] Furthermore, the sewage treatment module includes a compressor, an aeration tank, an evaporator and an adsorption device; the output end of the sewage, air and waste heat utilization module is connected to the input end of the aeration tank; the output end of the aeration tank is connected to the input end of the evaporator; the output end of the evaporator is connected to the input end of the adsorption device.

[0010] Furthermore, the SOEC electrolytic cell includes an anode channel, a cathode channel, an anode, a cathode, an electrolyte and a connector.

[0011] Furthermore, it also includes a membrane separator and a hydrogen storage tank; the output end of the waste heat utilization module is connected to the input end of the membrane separator; the output end of the membrane separator is connected to the hydrogen storage tank.

[0012] Furthermore, the waste heat utilization module includes a first-stage heat exchanger and a second-stage heat exchanger; The first-stage heat exchanger and the second-stage heat exchanger are connected in series; the output end of the SOEC electrolytic cell is connected to the input end of the first-stage heat exchanger; the input end of the second-stage heat exchanger is connected to the output end of the SOEC electrolytic cell; and the output end of the second-stage heat exchanger is connected to the input end of the SOEC electrolytic cell.

[0013] Furthermore, an electric heater is connected to the connection between the output end of the second-stage heat exchanger and the input end of the SOEC electrolytic cell.

[0014] Furthermore, the output end of the first-stage heat exchanger is connected to the input end of the membrane separator.

[0015] The present invention also discloses a method for using the SOEC electrolysis oilfield wastewater hydrogen production system, comprising the following steps: Sewage and air are drawn into the sewage treatment module. The oxygen produced by the SOEC electrolytic cell is heated with water vapor by the waste heat utilization module and then passed into the sewage treatment module for aeration treatment of the sewage. The remaining oxygen after aeration treatment is stored in the oxygen storage tank. The hydrogen produced by the SOEC electrolytic cell is passed into the waste heat utilization module for waste heat utilization to heat water vapor. A part of the hydrogen is mixed with water vapor to create a reducing environment and enters the SOEC electrolytic cell, and the other part of the hydrogen is stored.

[0016] Furthermore, the SOEC oilfield wastewater electrolysis hydrogen production system also includes a membrane separator and a hydrogen storage tank; the other part of hydrogen enters the hydrogen storage tank through the membrane separator for storage.

[0017] Furthermore, the SOEC electrolytic cell includes an anode channel, a cathode channel, an anode, a cathode, an electrolyte and a connector; water vapor flows into the cathode channel, and after electrolysis, hydrogen flows out of the cathode channel, and oxygen flows out of the anode channel.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The invention discloses a system for producing hydrogen by electrolyzing oilfield sewage through SOEC. By setting a SOEC electrolytic cell, the electrolysis product of SOEC is fully utilized. The products obtained in the treatment process are useful resources of hydrogen and oxygen. High-purity oxygen can be used for oxidation treatment of oilfield sewage, and hydrogen can be used as clean and efficient energy to realize the resource utilization of oilfield sewage. At the same time, by utilizing the high-temperature characteristics of SOEC electrolysis, the produced high-temperature gas is recycled through a waste heat utilization module, thereby improving the energy utilization rate and reducing the input energy required for the system.

[0019] Furthermore, the system of the present invention produces only hydrogen, oxygen and water vapor during the treatment process, without any other toxic or harmful products. At the same time, no chemical or biological agents need to be added during the operation of the system, and no secondary pollution will be caused. In addition, the sewage treatment module includes an aeration tank, an electric heating evaporator, an adsorption device, and a membrane separator, and the system can effectively remove pollutants in oilfield sewage, with good environmental protection effects.

[0020] Furthermore, unlike other sewage electrolysis systems, this system uses SOEC batteries composed of all solids, which are stable, non-volatile, and highly safe; the requirements for water quality for electrolysis are also lower than those for other electrolytic cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The overall structure diagram of the SOEC electrolysis oilfield wastewater hydrogen production system of the present invention; Figure 2 This is the overall structural diagram of the sewage treatment module of the present invention; Figure 3 This is the overall structural diagram of the waste heat utilization module of the present invention; Among them: 1-wastewater treatment module; 101-compressor; 102-aeration tank; 103-evaporator; 104-adsorption device; 2-waste heat utilization module; 201-first stage heat exchanger; 202-second stage heat exchanger; 203-electric heater; 3-SOEC electrolytic cell; 4-membrane separator; 5-oxygen storage tank; 6-hydrogen storage tank. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0023] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings: like Figure 1 As shown, the SOEC electrolysis oilfield sewage hydrogen production system disclosed in the present invention mainly includes a sewage treatment module 1, a waste heat utilization module 2, a SOEC electrolytic cell 3, a membrane separator 4, an oxygen storage tank 5 and a hydrogen storage tank 6; the sewage treatment module 1 is connected to sewage and air; the output end of the sewage treatment module 1 is connected to the input end of the waste heat utilization module 2 and the oxygen storage tank 5; the output end of the SOEC electrolytic cell 3 is connected to the input end of the waste heat utilization module 2; the output end of the waste heat utilization module 2 is connected to the input end of the membrane separator 4; the output end of the membrane separator 4 is connected to the hydrogen storage tank 6; the output end of the waste heat utilization module 2 is connected to the input end of the sewage treatment module 1 and the input end of the SOEC electrolytic cell 3.

[0025] Among them, the sewage treatment module 1 is mainly used for pollution treatment and preheating of oilfield sewage; the waste heat utilization module 2 is used for waste heat utilization of oilfield sewage before it enters the SOEC electrolytic cell 3; the oxygen required by the aeration tank 102 is provided by the oxygen produced by the anode channel of the SOEC electrolytic cell 3 after heat exchange flowing out of the waste heat utilization module 2, and the air is provided by air extracted by the compressor 101. The amount of oxygen and air flowing into the aeration tank 102 is determined according to the flow rate and pollutant content of the oilfield wastewater; in order to prevent impurities such as salt from damaging the working efficiency of the evaporator 103, the evaporator 103 should be cleaned regularly; the adsorption device 104 is mainly used for desulfurization of oilfield wastewater, and activated carbon can be selected; the heating and evaporation of water vapor before entering the SOEC electrolytic cell 3 is completed by the evaporator 103 and the waste heat utilization module 2; the evaporator 103 needs to heat the water vapor to a temperature close to that required by the SOEC electrolytic cell 3, and then the waste heat utilization module 2 uses the high-temperature hydrogen and oxygen produced by the SOEC electrolytic cell 3 for the final heating; before entering the SOEC electrolytic cell 3 for electrolysis, the water vapor needs to be mixed with a part of the hydrogen to create a reducing environment for protection.

[0026] Preferably, the SOEC electrolytic cell 3 is divided into an anode channel, a cathode channel, an anode, a cathode, an electrolyte, and a connector. Water vapor flows into the cathode channel, and hydrogen flows out of the cathode channel after electrolysis, and oxygen flows out of the anode channel. In the present invention, the hydrogen flowing out of the cathode channel of the SOEC electrolytic cell 3 does not directly enter the hydrogen storage tank 6, but first enters the waste heat utilization module 2 for waste heat utilization, and a part of the hydrogen is mixed with the water vapor entering the waste heat utilization module 2 to create a reducing environment for electrolysis and protect the system.

[0027] Preferably, since the water vapor temperature required by the SOEC electrolytic cell 3 is very high and the temperature of the produced gas is also very high, the sewage treatment module 1 does not completely heat the water vapor to the temperature required by the SOEC electrolytic cell 3, but heats it to a certain temperature and then reheats the hydrogen and oxygen produced by the SOEC electrolytic cell 3, and heats them to the required temperature through the waste heat utilization module 2.

[0028] Preferably, if Figure 2 As shown, the sewage treatment module 1 includes a compressor 101, an aeration tank 102, an evaporator 103 and an adsorption device 104, and is mainly used for pollution treatment and preheating of oilfield sewage. The compressed air of the compressor 101 is mixed with a part of the oxygen flowing out of the waste heat utilization module 2 and enters the aeration tank 102. A reaction occurs in the aeration tank 102 to remove COD, ammonia nitrogen, phosphorus, etc. in the oilfield sewage. The excess oxygen flowing out of the waste heat utilization module 2 is stored in the oxygen storage tank 5. The sewage is then heated and evaporated by the evaporator 103, and finally desulfurized by the adsorption process of the adsorption device and flows into the waste heat utilization module 2.

[0029] Preferably, if Figure 3 As shown, the waste heat utilization module 2 includes a first-stage heat exchanger 201, a second-stage heat exchanger 202 and an electric heater 203. The water vapor flows through the first-stage heat exchanger 201 and the second-stage heat exchanger 202 in sequence and is heated by hydrogen and oxygen in succession. According to the different gas enthalpy flow rates, the hydrogen with a larger enthalpy flow rate is supplied to the first-stage heat exchanger 201, and the oxygen is supplied to the second-stage heat exchanger 202. The electric heater 203 is added after the first-stage heat exchanger 201 and the second-stage heat exchanger 202. When the temperature of the water vapor after the heat exchange between hydrogen and oxygen is still insufficient, the electric heater 203 is operated to heat the water vapor.

[0030] Preferably, a membrane separator 4 is provided before the hydrogen enters the hydrogen storage tank 6 to remove residual water vapor and organic matter, etc. The separated pure hydrogen enters the hydrogen storage tank 6 for storage, and the separated water is injected back into the ground.

[0031] Example 1 The present invention discloses a system including a sewage treatment module 1, a waste heat utilization module 2, a SOEC electrolytic cell 3 and an oxygen storage tank 5; the sewage treatment module 1 is connected to sewage and air; the output end of the sewage treatment module 1 is connected to the input end of the waste heat utilization module 2 and the oxygen storage tank 5; the output end of the SOEC electrolytic cell 3 is connected to the input end of the waste heat utilization module 2; the output end of the waste heat utilization module 2 is connected to the input end of the sewage treatment module 1 and the input end of the SOEC electrolytic cell 3. By setting the SOEC electrolytic cell 3, the electrolysis product of SOEC is fully utilized, and the products obtained in the treatment process are useful resources of hydrogen and oxygen. High-purity oxygen can be used for oxidation treatment of oilfield sewage, and hydrogen can be used as clean and efficient energy to realize the resource utilization of oilfield sewage; at the same time, by utilizing the high-temperature characteristics of SOEC electrolysis, the high-temperature gas produced is recycled through the waste heat utilization module 2, which improves the energy utilization rate and reduces the input energy required by the system.

[0032] Example 2 On the basis of Example 1, the sewage treatment module 1 includes a compressor 101, an aeration tank 102, an evaporator 103 and an adsorption device 104; the output end of the sewage, air and waste heat utilization module 2 is connected to the input end of the aeration tank 102; the output end of the aeration tank 102 is connected to the input end of the evaporator 103; the output end of the evaporator 103 is connected to the input end of the adsorption device 104.

[0033] Example 3 The SOEC electrolytic cell 3 comprises an anode channel, a cathode channel, an anode, a cathode, an electrolyte and a connector; water vapor flows into the cathode channel, hydrogen flows out of the cathode channel after electrolysis, and oxygen flows out of the anode channel.

[0034] Example 4 On the basis of Example 1, it further includes a membrane separator 4 and a hydrogen storage tank 6; the output end of the waste heat utilization module 2 is connected to the input end of the membrane separator 4; the output end of the membrane separator 4 is connected to the hydrogen storage tank 6.

[0035] Example 5 The waste heat utilization module 2 includes a first-stage heat exchanger 201 and a second-stage heat exchanger 202; The first-stage heat exchanger 201 and the second-stage heat exchanger 202 are connected in series; the output end of the SOEC electrolytic cell 3 is connected to the input end of the first-stage heat exchanger 201; the input end of the second-stage heat exchanger 202 is connected to the output end of the SOEC electrolytic cell 3; the output end of the second-stage heat exchanger 202 is connected to the input end of the SOEC electrolytic cell 3; since the water vapor temperature required by the SOEC electrolytic cell 3 is very high and the temperature of the produced gas is also very high, the sewage treatment module 1 does not completely heat the water vapor to the required temperature of the SOEC electrolytic cell 3, but after heating to a certain temperature, the hydrogen and oxygen produced by the SOEC electrolytic cell 3 are recycled and heated to the required temperature by the waste heat utilization module 2.

[0036] Example 6 The method for using the SOEC electrolysis oilfield wastewater hydrogen production system of the present invention comprises the following steps: Sewage and air are drawn into the sewage treatment module 1, and the oxygen produced by the SOEC electrolytic cell 3 is heated by the waste heat utilization module 2 and then introduced into the sewage treatment module 1 to aerate the sewage. The remaining oxygen after the aeration treatment is stored in the oxygen storage tank 5; the hydrogen produced by the SOEC electrolytic cell 3 is introduced into the waste heat utilization module 2 for waste heat utilization to heat the water vapor. A part of the hydrogen is mixed with the water vapor to create a reducing environment and enters the SOEC electrolytic cell 3, and the other part of the hydrogen is stored.

[0037] The system of the present invention produces hydrogen by electrolyzing oilfield sewage, realizing the effective utilization of sewage resources and reducing the demand for traditional water resources. In addition, the system also integrates a waste heat utilization module 2, which can recover the heat generated during the SOEC electrolysis process and use it to heat the water vapor entering the electrolytic cell, thereby improving the energy utilization efficiency; by electrolyzing sewage to produce hydrogen, the system can reduce the dependence on traditional fossil fuels and reduce greenhouse gas emissions. At the same time, the sewage treatment module 1 can purify sewage and reduce environmental pollution; the system integrates multiple modules such as sewage treatment, waste heat utilization, SOEC electrolysis, and hydrogen storage to form a complete hydrogen production process. This highly integrated system design simplifies the operating process and improves the stability and reliability of the system; the system can flexibly adjust the working state of each module according to actual needs. For example, when the pollutant concentration in the sewage is high, the water quality can be ensured to meet the standard by increasing the processing time of the sewage treatment module 1 or improving the processing efficiency; when more hydrogen is needed, the hydrogen production can be increased by adjusting the working parameters of the SOEC electrolytic cell 3.

[0038] At the same time, the system uses oilfield wastewater as raw material, which can reduce the cost of hydrogen production. At the same time, the waste heat utilization module 2 can reduce energy consumption and further reduce operating costs. In addition, the system can also produce oxygen as a by-product, which increases economic benefits; it adopts advanced SOEC electrolysis technology and membrane separation technology to improve the efficiency and purity of hydrogen production. At the same time, by optimizing the system design and operating procedures, automatic control and intelligent management are realized, and the operating efficiency and safety of the system are improved; the system conforms to the concept of sustainable development, and by using renewable energy (such as solar energy, wind energy, etc.) to provide electricity for the SOEC electrolysis cell, zero-emission hydrogen production can be achieved. In addition, with the continuous advancement of technology and the reduction of costs, the application prospects of this system will be broader.

[0039] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A SOEC system for producing hydrogen by electrolyzing oilfield wastewater, characterized in that: The invention comprises a sewage treatment module (1), a waste heat utilization module (2), an SOEC electrolytic cell (3) and an oxygen storage tank (5); the sewage treatment module (1) is connected to sewage and air; the output end of the sewage treatment module (1) is connected to the input end of the waste heat utilization module (2) and the oxygen storage tank (5); the output end of the SOEC electrolytic cell (3) is connected to the input end of the waste heat utilization module (2); The output end of the waste heat utilization module (2) is connected to the input end of the sewage treatment module (1) and the input end of the SOEC electrolytic cell (3).

2. A SOEC system for producing hydrogen by electrolysis of oilfield wastewater according to claim 1, characterized in that: The sewage treatment module (1) comprises a compressor (101), an aeration tank (102), an evaporator (103) and an adsorption device (104); the output end of the sewage, air and waste heat utilization module (2) is connected to the input end of the aeration tank (102); the output end of the aeration tank (102) is connected to the input end of the evaporator (103); and the output end of the evaporator (103) is connected to the input end of the adsorption device (104).

3. A SOEC system for producing hydrogen by electrolysis of oilfield wastewater according to claim 1, characterized in that: The SOEC electrolytic cell (3) comprises an anode channel, a cathode channel, an anode, a cathode, an electrolyte and a connector.

4. A SOEC system for producing hydrogen by electrolysis of oilfield wastewater according to claim 1, characterized in that: It also includes a membrane separator (4) and a hydrogen storage tank (6); the output end of the waste heat utilization module (2) is connected to the input end of the membrane separator (4); and the output end of the membrane separator (4) is connected to the hydrogen storage tank (6).

5. A SOEC system for producing hydrogen by electrolyzing oilfield wastewater according to claim 4, characterized in that: The waste heat utilization module (2) comprises a first-stage heat exchanger (201) and a second-stage heat exchanger (202); The first-stage heat exchanger (201) and the second-stage heat exchanger (202) are connected in series; the output end of the SOEC electrolytic cell (3) is connected to the input end of the first-stage heat exchanger (201); the input end of the second-stage heat exchanger (202) is connected to the output end of the SOEC electrolytic cell (3); and the output end of the second-stage heat exchanger (202) is connected to the input end of the SOEC electrolytic cell (3).

6. A SOEC system for producing hydrogen by electrolyzing oilfield wastewater according to claim 5, characterized in that: An electric heater (203) is connected to the connection point between the output end of the second-stage heat exchanger (202) and the input end of the SOEC electrolytic cell (3).

7. A SOEC system for producing hydrogen by electrolyzing oilfield wastewater according to claim 5, characterized in that: The output end of the first-stage heat exchanger (201) is connected to the input end of the membrane separator (4).

8. The method for using the SOEC system for producing hydrogen by electrolyzing oilfield wastewater according to any one of claims 1 to 7, characterized in that: The following steps are involved: Sewage and air are drawn into the sewage treatment module (1); oxygen produced by the SOEC electrolytic cell (3) is heated by the waste heat utilization module (2) and then introduced into the sewage treatment module (1) to aerate the sewage; the remaining oxygen after the aeration treatment is stored in the oxygen storage tank (5); hydrogen produced by the SOEC electrolytic cell (3) is introduced into the waste heat utilization module (2) to heat water vapor for waste heat utilization; a portion of the hydrogen is mixed with the water vapor to produce a reducing environment and then introduced into the SOEC electrolytic cell (3); the other portion of the hydrogen is stored.

9. The method for using a SOEC electrolysis oilfield wastewater hydrogen production system according to claim 8, characterized in that: The SOEC oilfield wastewater electrolysis hydrogen production system further comprises a membrane separator (4) and a hydrogen storage tank (6); the other part of the hydrogen passes through the membrane separator (4) and enters the hydrogen storage tank (6) for storage.

10. The method for using a SOEC electrolysis oilfield wastewater hydrogen production system according to claim 8, characterized in that: The SOEC electrolytic cell (3) comprises an anode channel, a cathode channel, an anode, a cathode, an electrolyte and a connector; water vapor flows into the cathode channel, and after electrolysis, hydrogen flows out of the cathode channel, and oxygen flows out of the anode channel.

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