A system and method for in-situ electrochemical corrosion testing in a carbon dioxide-rich phase

Abstract

This invention discloses an in-situ testing system and method for electrochemical corrosion in carbon dioxide-rich phases, comprising a carbon dioxide pressurization device, a reaction vessel, a heating device, first test pieces, and an electrochemical analyzer. The carbon dioxide pressurization device is used to prepare pressurized carbon dioxide and inject it into the reaction vessel. The reaction vessel is used to provide and maintain a stable set temperature and pressure environment inside the vessel. The heating device includes a temperature control system and a heating jacket, which covers the reaction vessel and heats the reaction vessel under the control of the temperature control system. Two first test pieces form a dual electrode, which is electrically connected to the electrochemical analyzer via wires. The dual electrode consists of two first test pieces arranged in a grid-like cross pattern. The electrode array spacing of the dual electrode is ≤0.1mm, which enables the dual electrode test surface to have good conductivity under the action of a discontinuous thin liquid film, realizing the simulation of the non-uniform and discontinuous characteristics of metal / solution interface processes and electrochemical parameters.

Description

Technical Field

[0001] This invention relates to the field of electrochemical corrosion technology, and in particular to an in-situ testing system and method for electrochemical corrosion of carbon dioxide-rich phases. Background Technology

[0002] Carbon dioxide, as an acidic gas, forms a carbonated solution when dissolved in water, which can severely corrode metallic materials. Furthermore, carbon dioxide is a major greenhouse gas, and its emissions contributing to global climate change are a matter of international consensus.

[0003] Under my country's vision of achieving carbon neutrality, the field of carbon dioxide capture, utilization, and storage (CCUS) faces enormous demand. Pipeline transportation, as a high-capacity, low-cost, stable, and continuous method, is a crucial link in transporting carbon dioxide from capture sites to storage or utilization sites. During pipeline transportation, to improve efficiency and reduce costs, carbon dioxide is typically compressed to a high-pressure state, i.e., transported in a supercritical or dense-phase state. However, pipeline-transported carbon dioxide often contains a certain amount of water. Under certain environmental conditions, the aqueous phase precipitates on the pipe wall surface, forming a thin liquid film. This film then dissolves the carbon dioxide, forming a corrosive electrolyte solution that severely corrodes the pipeline, threatening the safe operation of pipeline transportation and the successful implementation of CCUS.

[0004] Unlike conventional corrosion problems in carbon dioxide-containing oil and gas pipelines, in carbon dioxide transport pipelines, carbon dioxide is the dominant phase, i.e., a carbon dioxide-rich phase; while water is an impurity phase, precipitating on the metal surface to form a thin liquid film. In this case, the metal / solution interface processes and electrochemical parameters exhibit non-uniform and discontinuous characteristics. This discontinuity makes it difficult to conduct in-situ testing and characterization of the electrochemical corrosion behavior of the pipe wall material under the action of a carbon dioxide-rich phase thin liquid film using conventional three-electrode systems. Existing testing methods and devices typically immerse the test electrodes in a saturated carbon dioxide solution, which differs significantly from the thin liquid film solution system in a carbon dioxide-rich phase. Such a corrosion environment cannot accurately simulate the corrosion behavior of materials under the action of a carbon dioxide-rich phase thin liquid film. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention provides an in-situ testing system and method for electrochemical corrosion of carbon dioxide-rich phases, comprising the following specific technical solutions:

[0006] An in-situ testing system for electrochemical corrosion in carbon dioxide-rich phases includes a carbon dioxide pressurization device, a reaction vessel, a heating device, a first test piece, and an electrochemical analyzer.

[0007] The carbon dioxide pressurization device is used to prepare pressurized carbon dioxide and is fixedly connected to the reaction vessel through a delivery pipe to inject the pressurized carbon dioxide into the reaction vessel;

[0008] The reactor is used to provide and maintain a stable set temperature and pressure environment inside the reactor. The set temperature inside the reactor is greater than 31.1℃ and the set pressure is greater than 7.38MPa.

[0009] The heating device includes a temperature control system and a heating jacket. The heating jacket covers the reaction vessel, and the reaction vessel is heated by the heating jacket under the control of the temperature control system.

[0010] The first test piece is placed inside the reaction vessel, and two first test pieces form a dual electrode. The dual electrode is electrically connected to an electrochemical testing instrument outside the reaction vessel via wires.

[0011] Furthermore, the first test piece includes a first metal strip, a plurality of second metal strips, and a third metal strip; the third metal strip is disposed at the end of the first metal strip and is disposed perpendicularly to the second metal strip at equal intervals on the same side of the first metal strip.

[0012] Furthermore, the two first test pieces arranged in a cross-shaped grid pattern constitute a dual electrode, and the second metal strips of the dual electrodes are arranged at equal intervals to form an electrode array.

[0013] Furthermore, the spacing between adjacent second metal strips of the dual electrodes is ≤0.1mm; the dual electrodes are encapsulated with epoxy resin; the encapsulated dual electrodes are ground to expose the dual electrode test surface, and the dual electrode test surface is polished to a roughness of 0.01. -0.08 between.

[0014] Furthermore, the thickness of the first test piece is 2mm; the length of the first metal strip is 30mm and the width is 2mm; the length of the second metal strip is 18mm and the width is 0.8mm; and the length of the third metal strip is 18mm and the width is 5mm.

[0015] Furthermore, the dual electrodes are fixedly installed inside the upper part of the reactor via polytetrafluoroethylene tubes; the wires are embedded inside the polytetrafluoroethylene tubes and are respectively connected to the third metal strips located at both ends of the dual electrodes.

[0016] Furthermore, the in-situ testing system also includes a second test piece; multiple second test pieces are provided and suspended inside the reactor by a polytetrafluoroethylene bracket.

[0017] Furthermore, a motor is installed above the reactor, and the output shaft of the motor is connected to a stirring shaft. The stirring shaft penetrates into the interior of the reactor, and stirring blades are installed at the end of the stirring shaft. The stirring blades rotate forward and / or in reverse at a set frequency to simulate the flow conditions of carbon dioxide being transported in an actual pipeline within the reactor.

[0018] Furthermore, the two first test pieces are arranged in concentric rings or mosquito coils to form a dual electrode, and the distance between the electrode test surfaces of the dual electrode is ≤0.1mm.

[0019] An in-situ testing method for electrochemical corrosion of carbon dioxide-rich phases, using the aforementioned in-situ testing system, includes the following steps:

[0020] S1, add deionized water into the reactor, and set the volume of deionized water so that the highest liquid level does not contact any part of the first and second test pieces;

[0021] S2, the surfaces of the dual electrodes other than the test surface are encapsulated with epoxy resin. Before encapsulation, the third metal strips at both ends of the test surface are connected to the wires and led out. After encapsulation, the dual electrode test surfaces are polished to a mirror finish by water-polishing sandpaper. Then, they are rinsed with deionized water and anhydrous ethanol respectively, dried with cold air, and placed in a dry environment for later use.

[0022] S3, Install the packaged dual electrodes on the lid of the high-temperature and high-pressure reactor, and set the position of the dual electrodes inside the reactor so that the test surface of the dual electrodes faces downward;

[0023] The second test piece is suspended on a polytetrafluoroethylene bracket, and the entire second test piece is completely exposed above the surface of the deionized water.

[0024] S4, for a sealed reactor, turn on the nitrogen booster pump, open the reactor exhaust valve, inject pressurized carbon dioxide into the reactor, and maintain this for at least 60 minutes before closing the reactor exhaust valve. When the gas pressure inside the reactor is greater than 7.38 MPa, close the delivery pipe.

[0025] S5, start the temperature control system, heat the carbon dioxide in the reactor through the heating jacket, measure the temperature in the reactor through the temperature sensor, and control the temperature in the reactor to be maintained above 31.1℃;

[0026] S6. Based on the data collected by the electrochemical analyzer, plot the polarization curves and AC impedance spectra of the dual electrodes under the action of a carbon dioxide-rich phase thin liquid film.

[0027] After maintaining the test environment inside the reactor for at least 24 hours, the second test piece was removed, its corrosion status was observed, and the corrosion of the second test piece was evaluated using analytical testing methods such as scanning electron microscopy and energy dispersive spectroscopy.

[0028] Based on the acquired dual-electrode polarization curves and AC impedance spectra, as well as the corrosion evaluation of the second test piece, in-situ testing and analysis of the electrochemical corrosion of the carbon dioxide-rich phase were completed.

[0029] Based on the above technical solution, the in-situ testing system and method for electrochemical corrosion of carbon dioxide-rich phases described in this invention has the following beneficial effects:

[0030] 1. The dual electrode consists of two first test pieces arranged in a cross-shaped grid pattern. The second metal strips of the first test pieces are arranged at equal intervals to form an electrode array. The distance between adjacent second metal strips is ≤0.1mm, which enables the dual electrode test surface to have good conductivity under the action of discontinuous thin liquid film, and realizes the simulation of the non-uniform and discontinuous characteristics of metal / solution interface processes and electrochemical parameters.

[0031] 2. Encapsulating the dual electrodes with epoxy resin ensures insulation between the working and auxiliary electrodes. Furthermore, polishing the test surfaces of the dual electrodes reduces their surface roughness to within 0.01 mm. -0.08 Between these, a mirror-like effect is achieved, resulting in a smooth, flat surface and uniform structure on the dual-electrode test surface.

[0032] 3. The first and second test pieces were fabricated from materials sourced from the carbon dioxide transport pipeline at the work site, achieving a realistic simulation of the pipeline. Furthermore, detailed dimensional settings were made for the first test piece to ensure sufficient test area and strength.

[0033] 4. The reactor is equipped with dual-electrode test plates and corrosion test plates, which can collect dual-electrode polarization curves and AC impedance spectra through an electrochemical analyzer, and evaluate the corrosion of the second test plate. This allows for scientific and effective in-situ testing and analysis of electrochemical corrosion of carbon dioxide-rich phases, providing technical guidance for supercritical carbon dioxide pipeline transportation in actual operations.

[0034] 5. The carbon dioxide pressurization device pressurizes carbon dioxide by driving a nitrogen booster pump with high-pressure nitrogen. Nitrogen is an inert gas, and there is no oil or other solvent adhering to the nitrogen booster pump, thus ensuring that the carbon dioxide entering the reactor remains pure.

[0035] 6. The heating jacket is driven by a temperature control system to heat the reactor. The temperature inside the reactor can be adjusted according to actual operating requirements and a stable set temperature is maintained. Attached Figure Description

[0036] Figure 1 : Schematic diagram of the overall structure of the test system in the embodiment;

[0037] Figure 2 : Schematic diagram of the dual-electrode structure in the embodiment;

[0038] Figure 3 : Schematic diagram of dual-electrode packaging in the embodiment;

[0039] Figure 4 : Schematic diagram of the dual-electrode electrochemical impedance spectroscopy measurement results after 120 hours of testing in the example;

[0040] Figure 5 : Schematic diagram of the scanning electron microscope observation results of the slide surface after 120 hours of testing in the example.

[0041] Symbol Explanation

[0042] 101-Carbon dioxide gas cylinder, 102-Nitrogen booster pump, 103-High-pressure nitrogen gas cylinder, 104-Delivery pipe, 105-First valve;

[0043] 201-Reaction vessel, 202-Motor, 203-Stirring shaft, 204-Stirring blades;

[0044] 301 - Temperature control system; 302 - Heating jacket;

[0045] 4-First test piece, 401-First metal strip, 402-Second metal strip, 403-Third metal strip, 404-Epoxy resin, 405-PTFE tube;

[0046] 5-Second test piece, 501-PTFE support;

[0047] 6-Electrochemical Analyzer;

[0048] 701 - Exhaust gas collection device, 702 - Gas pipe, 703 - Second valve. Detailed Implementation

[0049] It should be noted that:

[0050] 1. Certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in their functions.

[0051] 2. Unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] 3. Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning as understood by a person of ordinary skill in the art to which this disclosure pertains.

[0053] The following is in conjunction with the appendix Figure 1 -Appendix Figure 5 The present invention will be described in detail by way of examples.

[0054] This embodiment describes an in-situ testing system for electrochemical corrosion in carbon dioxide-rich phases, including...

[0055] Carbon dioxide pressurization device, reaction vessel 201, heating device, first test piece 4, electrochemical analyzer 6.

[0056] A carbon dioxide pressurization device is used to prepare pressurized carbon dioxide and is fixedly connected to a reaction vessel 201 via a delivery pipe 104 to inject pressurized carbon dioxide into the reaction vessel 201. A first valve 105 is installed on the delivery pipe 104 to control the flow rate of carbon dioxide in the delivery pipe 104.

[0057] The carbon dioxide pressurization device includes a carbon dioxide tank 101, a nitrogen booster pump 102, and a high-pressure nitrogen tank 103.

[0058] High-pressure nitrogen tank 103, carbon dioxide tank 101, and delivery pipe 104 are sequentially connected to the driving gas inlet, air inlet, and air outlet of nitrogen booster pump 102. Nitrogen drives nitrogen booster pump 102 to operate and output carbon dioxide at a set pressure. The set pressure should be greater than 7.38 MPa.

[0059] Reactor 201 is a high-temperature, high-pressure reactor used to provide and maintain a stable internal temperature and pressure environment. The operating temperature range of reactor 201 is set to room temperature - 150℃, and the operating pressure range is set to atmospheric pressure - 20MPa.

[0060] A motor 202 is installed above the reactor 201. The motor output shaft is connected to a stirring shaft 203, which penetrates into the reactor 201. Stirring blades 204 are installed at the end of the stirring shaft 203. The purpose of the stirring inside the reactor 201 is to simulate the flow conditions when carbon dioxide is transported through a pipeline.

[0061] The heating device includes a temperature control system 301 and a heating jacket 302. The heating jacket 302 covers the reactor 201. Under the control of the temperature control system 301, the heating jacket 302 heats the reactor 201, raising and stabilizing the temperature inside the reactor 201 at a set temperature. The set temperature should be greater than 31.1°C.

[0062] The first test piece 4 is made of metal. In this embodiment, the first test piece 4 is made from materials sourced from the carbon dioxide transport pipeline at the work site to achieve a realistic simulation of the transport pipeline.

[0063] The first test piece 4 includes a first metal strip 401, a plurality of second metal strips 402, and a third metal strip 403. The third metal strip 403 is disposed at the end of the first metal strip 401 and is disposed perpendicularly to the second metal strips 402 at equal intervals on the same side of the first metal strip 401.

[0064] To achieve sufficient test area and strength, the dimensions of the first test piece 4 are set as follows in this embodiment: the thickness of the first test piece 4 is 2mm; the length of the first metal strip 401 is 30mm and the width is 2mm; the length of the second metal strip 402 is 18mm and the width is 0.8mm; and the length of the third metal strip 403 is 18mm and the width is 5mm.

[0065] Two opposing grid-like cross-arranged first test pieces 4 constitute a dual electrode, including a working electrode and an auxiliary electrode, which also serves as a reference electrode.

[0066] The second metal strips 402 of the dual electrodes are arranged at equal intervals to form an electrode array. In order to obtain the technical effect of good conductivity of the dual electrode test surface under the action of discontinuous thin liquid film, the spacing between adjacent second metal strips 402 of the dual electrodes is ≤0.1mm.

[0067] To ensure insulation between the working and auxiliary electrodes, the dual electrodes are encapsulated using epoxy resin 404. After encapsulation, the dual electrodes are polished to expose the test surfaces. To achieve a smooth, flat surface and uniform structure, the test surfaces are further polished to a roughness of 0.01. -0.08 Between them, a mirror effect is achieved.

[0068] The dual electrodes are fixedly mounted inside the upper part of the reactor 201 via a polytetrafluoroethylene (PTFE) tube 405 and electrically connected to the electrochemical analyzer 6 outside the reactor 201 via wires. The wires are embedded inside the PTFE tube 405, and the connection between the wires and the dual electrodes is achieved by soldering. To obtain sufficient welding strength, the wires are connected to the working electrode third metal strip 403 and the auxiliary electrode third metal strip 403 located at both ends of the dual electrode test surface, respectively.

[0069] The second test piece 5 is made of metal. In this embodiment, the second test piece 5 is also made from materials sourced from the carbon dioxide transport pipeline at the work site to achieve a realistic simulation of the transport pipeline.

[0070] Multiple second test pieces 5 are configured and suspended inside the reactor 201 by a polytetrafluoroethylene bracket 501.

[0071] In this embodiment, the system further includes a tail gas collection device 701, which is connected to the exhaust valve of the reaction vessel 201 via a gas pipe 702, and a second valve 703 is provided on the gas pipe 702; the device stores an alkaline solution for collecting and neutralizing carbon dioxide that escapes or is discharged from the reaction vessel 201.

[0072] In addition, the working electrode and auxiliary electrode in the dual electrode can also be designed in the form of concentric rings or mosquito coils. In order to obtain the technical effect of good conductivity between the working electrode and auxiliary electrode test surfaces under the action of discontinuous thin liquid film, the distance between the two electrode test surfaces should be ≤0.1mm.

[0073] Based on the system described above, this embodiment also describes an in-situ testing method for electrochemical corrosion of carbon dioxide-rich phases, including the following steps:

[0074] S1. Select a high-temperature and high-pressure reactor 201 with a working volume of 1.6L. Add deionized water into the reactor 201. The amount or volume of deionized water is set so that the highest liquid level does not contact any part of the first test piece 4 and the second test piece 5.

[0075] S2, the surfaces of the dual electrodes other than the test surface are encapsulated with epoxy resin 404. Before encapsulation, the third metal strip 403 located at both ends of the test surface is connected to the wire and led out. After encapsulation, the dual electrode test surface is polished to a mirror finish by water sandpaper. Then it is rinsed with deionized water and anhydrous ethanol respectively, dried with cold air and placed in a dry environment for later use.

[0076] S3, install the packaged dual electrodes on the lid of the high temperature and high pressure reactor, and set the position of the dual electrodes inside the reactor 201 so that the test surface of the dual electrodes faces downward. This position setting can obtain the corrosion effect of the flowing thin liquid film.

[0077] The second test piece 5 is suspended on the polytetrafluoroethylene bracket 501, and the second test piece 5 is positioned so that it is completely exposed above the surface of the deionized water.

[0078] S4. In the sealed reactor 201, turn on the nitrogen booster pump 102, open the reactor exhaust valve, and inject pressurized carbon dioxide into the reactor. Maintain this for at least 60 minutes, then close the reactor exhaust valve. This operation method can remove residual gas and dissolved air from the deionized water in the reactor. The reactor pressure gauge displays the gas pressure inside reactor 201 in real time. When the gas pressure exceeds 7.38 MPa, close the delivery pipe 104.

[0079] S5, start the temperature control system 301, heat the carbon dioxide in the reactor through the heating jacket 302, measure the temperature in the reactor through the temperature sensor, and control the temperature in the reactor to be maintained above 31.1℃.

[0080] S6. Based on the data collected by the electrochemical analyzer 6, plot the polarization curves and AC impedance spectra of the two electrodes under the action of a carbon dioxide-rich phase thin liquid film.

[0081] After maintaining the test environment inside the reactor for at least 24 hours, the second test piece 5 was removed, the corrosion state of the second test piece 5 was observed, and the corrosion of the second test piece 5 was evaluated using analytical testing methods such as scanning electron microscopy and energy dispersive spectroscopy.

[0082] Based on the acquired dual-electrode polarization curves and AC impedance spectra, as well as the corrosion evaluation of the second test piece 5, in-situ testing and analysis of the electrochemical corrosion of the carbon dioxide-rich phase were completed.

[0083] The method described in this embodiment can also be used to perform in-situ corrosion testing and analysis of thin liquid films after adding corrosion inhibitors to carbon dioxide-rich phases, thereby evaluating the effectiveness of the corrosion inhibitors.

[0084] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. An in-situ testing method for electrochemical corrosion of carbon dioxide-rich phases, using an in-situ testing system, the in-situ testing system comprising a carbon dioxide pressurizing device, a reaction vessel, a heating device, a first test piece, a second test piece, and an electrochemical analyzer; the carbon dioxide pressurizing device is used to prepare pressurized carbon dioxide and is fixedly connected to the reaction vessel via a delivery pipe to inject the pressurized carbon dioxide into the reaction vessel; the reaction vessel is used to provide and maintain a stable set temperature and pressure environment inside the vessel, the set temperature inside the reaction vessel being greater than 31.1℃ and the set pressure being greater than 7.38MPa; the heating device includes a temperature control system and a heating jacket, the heating jacket covering the reaction vessel, and heating the reaction vessel under the control of the temperature control system; the first test piece is disposed inside the reaction vessel, two first test pieces forming a dual electrode, the dual electrode being electrically connected to the electrochemical analyzer outside the reaction vessel via wires; multiple second test pieces are disposed inside the reaction vessel and suspended by a polytetrafluoroethylene bracket; characterized in that... Includes the following steps: S1, add deionized water into the reactor, and set the volume of deionized water so that the highest liquid level does not contact any part of the first and second test pieces; S2, the surfaces of the dual electrodes other than the test surface are encapsulated with epoxy resin. Before encapsulation, the third metal strips at both ends of the test surface are connected to the wires and led out. After encapsulation, the dual electrode test surfaces are polished to a mirror finish by water-polishing sandpaper. Then, they are rinsed with deionized water and anhydrous ethanol respectively, dried with cold air, and placed in a dry environment for later use. S3, Install the packaged dual electrodes on the lid of the high-temperature and high-pressure reactor, and set the position of the dual electrodes inside the reactor so that the test surface of the dual electrodes faces downward; The second test piece is suspended on a polytetrafluoroethylene bracket, and the entire second test piece is completely exposed above the surface of the deionized water. S4, for a sealed reactor, turn on the nitrogen booster pump, open the reactor exhaust valve, inject pressurized carbon dioxide into the reactor, and maintain this for at least 60 minutes before closing the reactor exhaust valve. When the gas pressure inside the reactor is greater than 7.38 MPa, close the delivery pipe. S5, start the temperature control system, heat the carbon dioxide in the reactor through the heating jacket, measure the temperature in the reactor through the temperature sensor, and control the temperature in the reactor to be maintained above 31.1℃; S6. Based on the data collected by the electrochemical analyzer, plot the polarization curves and AC impedance spectra of the dual electrodes under the action of a carbon dioxide-rich phase thin liquid film. After maintaining the test environment inside the reactor for at least 24 hours, the second test piece was removed, its corrosion status was observed, and the corrosion of the second test piece was evaluated using analytical testing methods such as scanning electron microscopy and energy dispersive spectroscopy. Based on the acquired dual-electrode polarization curves and AC impedance spectra, as well as the corrosion evaluation of the second test piece, in-situ testing and analysis of the electrochemical corrosion of the carbon dioxide-rich phase were completed.

2. The in-situ testing method for electrochemical corrosion of carbon dioxide-rich phases according to claim 1, characterized in that, The first test piece includes a first metal strip, multiple second metal strips, and a third metal strip; the third metal strip is disposed at the end of the first metal strip and is disposed perpendicularly to the second metal strips at equal intervals on the same side of the first metal strip; Two opposing grid-like cross-arranged first test pieces constitute a dual electrode, and the second metal strips of the dual electrodes are arranged at equal intervals to form an electrode array.

3. The in-situ testing method for electrochemical corrosion of carbon dioxide-rich phases according to claim 2, characterized in that, The spacing between adjacent second metal strips of the dual electrodes is ≤0.1mm; The dual electrodes are encapsulated with epoxy resin; The encapsulated dual electrodes are ground until the dual electrode test surfaces are exposed, and then polished to a roughness of 0.

01. -0.08 between.

4. The in-situ testing method for electrochemical corrosion of carbon dioxide-rich phases according to claim 3, characterized in that, The thickness of the first test piece is 2 mm; The first metal strip is 30mm long and 2mm wide; The second metal strip is 18mm long and 0.8mm wide; The third metal strip is 18mm long and 5mm wide.

5. The in-situ testing method for electrochemical corrosion of carbon dioxide-rich phases according to claim 3, characterized in that, The dual electrodes are fixedly installed inside the upper part of the reactor via polytetrafluoroethylene tubes. The wires are embedded inside the polytetrafluoroethylene tube and are connected to the third metal strips located at both ends of the dual electrodes.

6. The in-situ testing method for electrochemical corrosion of carbon dioxide-rich phases according to any one of claims 1-5, characterized in that, A motor is installed above the reactor, and the output shaft of the motor is connected to a stirring shaft. The stirring shaft penetrates into the interior of the reactor, and stirring blades are installed at the end of the stirring shaft. The stirring blades rotate forward and / or in reverse at a set frequency to simulate the flow conditions of carbon dioxide being transported in an actual pipeline within the reactor.

7. The in-situ testing method for electrochemical corrosion of carbon dioxide-rich phases according to any one of claims 1-5, characterized in that, The carbon dioxide pressurization device includes a carbon dioxide tank, a nitrogen booster pump, and a high-pressure nitrogen tank. The high-pressure nitrogen tank, the carbon dioxide tank, and the delivery pipe are sequentially connected to the driving gas inlet, the air inlet, and the air outlet of the nitrogen booster pump. The nitrogen drives the nitrogen booster pump to operate and output carbon dioxide at a set pressure.

8. The in-situ testing method for electrochemical corrosion of carbon dioxide-rich phases according to claim 1, characterized in that, Two first test pieces are arranged in concentric rings or mosquito coils to form a dual electrode, and the distance between the electrode test surfaces of the dual electrode is ≤0.1mm.

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