Device and method for establishing CO2 pipeline transportation steel corrosion rate indication chart

Abstract

The invention discloses a device and a method for establishing a CO2 pipeline transportation steel corrosion rate indication chart. The device comprises a steel test sample, a reaction kettle, a CO2 gas storage tank, a sodium chloride solution storage tank and a data acquisition system, the steel test sample is arranged in the reaction kettle; and the reaction kettle is respectively connected with a CO2 gas storage tank and a sodium chloride solution storage tank. The method comprises the following steps: mounting a steel test hanging piece in a reaction kettle; vacuumizing the reaction kettle, and conveying materials in the CO2 gas storage tank and the sodium chloride solution storage tank into the reaction kettle for reaction; calculating the corrosion rate after the reaction is finished; according to the corrosion rate, a fitting interpolation method is used for drawing a corrosion rate characteristic graph, and a CO2 pipeline transportation steel corrosion rate indication chart is obtained. According to the method, a ternary contour phase diagram is drawn in a fitting interpolation mode through a steel test sample experiment, and a CO2 pipeline transportation steel corrosion rate indication chart is established.

Description

Technical Field

[0001] This invention belongs to the field of steel technology, and in particular relates to an apparatus and method for establishing a corrosion rate indicator chart for CO2 pipeline steel. Background Technology

[0002] In the process of transporting CO2 through pipelines, pipeline corrosion is one of the bottlenecks restricting the development and application of carbon sequestration technology. While dry CO2 is not corrosive, the presence of water in the pipeline causes it to react with water, producing H2CO3 and HCO3-. - These corrosive substances, such as compounds, can continuously erode the inner wall material of pipelines, leading to thinning of the pipe wall, decreased strength, and even potential leaks and other safety accidents, seriously threatening the long-term stable operation and reliability of the pipeline system.

[0003] Domestic and international experts have conducted extensive research on CO2 pipeline corrosion, accumulating rich experience in CO2 corrosion behavior, mechanisms, and corrosion inhibition strategies. However, the following issues still urgently need to be addressed: Although there are numerous experimental studies on the influence and mechanisms of environmental factors on CO2 corrosion, pipeline transport conditions vary between different pipelines, necessitating analysis of actual operating conditions and evaluation of the corrosion degree of various steels based on these conditions. Furthermore, on-site corrosion experiments are required to comprehensively analyze corrosion behavior and mechanisms. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides an apparatus and method for establishing a corrosion rate indicator chart for CO2 pipeline steel.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] On one hand, the present invention provides an apparatus for establishing a corrosion rate indicator chart for CO2 pipeline steel, comprising a steel test sample, a reaction vessel, a CO2 storage tank, a sodium chloride solution storage tank, and a data acquisition system; the steel test sample is installed in the reaction vessel; the reaction vessel is connected to the CO2 storage tank and the sodium chloride solution storage tank respectively.

[0007] Preferably, the steel test sample is selected from at least one of Q345 steel, 20# steel, and 304 stainless steel.

[0008] In some specific embodiments, the steel hanging plate has a size of 30-40mm × 5-10mm × 2-5mm.

[0009] Preferably, the system also includes a booster pump for transferring CO2 from the CO2 storage tank to the reactor; the booster pump is connected to the reactor and the CO2 storage tank respectively via pipelines.

[0010] Preferably, a first valve is installed on the pipeline connecting the booster pump and the reactor.

[0011] Preferably, a second valve and a first pressure sensor are installed on the pipeline connecting the booster pump and the CO2 storage tank.

[0012] Preferably, it also includes a second pressure sensor for collecting the pressure inside the CO2 storage tank.

[0013] Preferably, the reaction vessel is connected to a sodium chloride solution storage tank via a pipeline; a third valve is installed on the pipeline connecting the reaction vessel and the sodium chloride solution storage tank.

[0014] Preferably, the system further includes a piston pump for conveying sodium chloride solution from a sodium chloride solution storage tank to a reaction vessel; the piston pump is connected to the sodium chloride solution storage tank via a pipeline; and a fourth valve is installed on the pipeline connecting the piston pump and the sodium chloride solution storage tank.

[0015] Preferably, it further includes an atomizing nozzle; the atomizing nozzle is disposed at the material inlet of the reactor and is connected to the pipeline connecting the reactor to the booster pump and the pipeline connecting the reactor to the sodium chloride solution storage tank, for atomizing the material in the CO2 storage tank and the sodium chloride solution storage tank and conveying it to the reactor.

[0016] Preferably, the data acquisition system includes a third pressure sensor for acquiring the pressure inside the reactor and an information acquisition mechanism for recording the information acquired by the third pressure sensor.

[0017] In another aspect, the present invention provides a method for establishing a corrosion rate indicator chart for CO2 pipeline steel based on the above-mentioned apparatus, comprising the following steps:

[0018] (1) Install the steel test clips into the reactor;

[0019] (2) Vacuum the reactor, and then transfer the materials from the CO2 storage tank and the sodium chloride solution storage tank to the reactor for reaction;

[0020] (3) After the reaction is complete, calculate the corrosion rate according to formula (1);

[0021]

[0022] In equation (1), R corr The corrosion rate is expressed in mm / a; m is the initial mass of the steel test strip in g; m t S1 represents the mass of the steel test strip after the reaction, in grams; S2 represents the surface area of ​​the steel test strip, in centimeters. 2 ρ represents the density of the steel test strip, in g / cm³. 3t represents the reaction time, in hours (h).

[0023] (4) Based on the calculated corrosion rate, the pressure, water content, and Cl inside the reactor are interpolated using a fitting interpolation method. - After concentration normalization, a corrosion rate characteristic map is plotted to obtain the corrosion rate indicator map of the CO2 pipeline steel.

[0024] In a preferred embodiment, the steel test plate is pretreated.

[0025] Preferably, the pretreatment includes sanding, solvent cleaning, and drying.

[0026] In a preferred embodiment, the reaction time is 150-200 hours.

[0027] Preferably, the pressure ranges from 3.5 to 7.5 MPa.

[0028] Preferably, the Cl - The concentration range is 1000–5000 mg / L.

[0029] Preferably, the moisture content ranges from 0.05% to 2%.

[0030] The beneficial effects of this invention are:

[0031] (1) This invention uses steel test specimens to experiment and employs fitting interpolation to draw a ternary contour phase diagram. Different Cl... - Concentration, pressure, and moisture content are used to determine the corrosion rate of steel under different conditions.

[0032] (2) This invention will include moisture content, Cl - The indicator charts created to show the effects of concentration and pressure on CO2 pipeline corrosion can quickly determine the corrosion rate of pipeline steel under different conditions, enabling the selection of suitable steel for pipelines in different environments. Attached Figure Description

[0033] The invention, its features, shape, and advantages will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. Like reference numerals denote like parts throughout the drawings. The drawings are not intentionally drawn to scale; the focus is on illustrating the spirit of the invention.

[0034] Figure 1 This is a schematic diagram of the device used to establish a corrosion rate indicator chart for CO2 pipeline steel in Embodiment 1 of the present invention.

[0035] Figure 2 This is a schematic diagram of the installation of the steel test bracket in Embodiment 1 of the present invention.

[0036] Figure 3 This is a graph showing the corrosion rate as a function of water content, as measured in Example 2 of this invention.

[0037] Figure 4 The corrosion rate measured in Example 3 of this invention is as follows: - Concentration change curve.

[0038] Figure 5 This is a graph showing the corrosion rate as a function of pressure, as measured in Example 4 of this invention.

[0039] Figure 6-8 These are corrosion rate indicator charts for Q345 steel, 20# steel, and 304 stainless steel established in Embodiment 5 of the present invention. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Therefore, the detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the protection scope of the present invention.

[0041] It should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0042] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0043] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] In this invention, unless otherwise specified, all equipment and raw materials are commercially available or commonly used in the industry. The methods described in the following embodiments are conventional methods in the art, unless otherwise specified.

[0045] Example 1

[0046] like Figure 1-2 As shown, this embodiment provides an apparatus for establishing a corrosion rate indicator chart for steel transported by CO2, including a steel test sample, a reaction vessel 1, a CO2 storage tank 3, a sodium chloride solution storage tank 5, and a data acquisition system 6; the steel test sample is installed in the reaction vessel 1; the reaction vessel 1 is connected to the CO2 storage tank 3 and the sodium chloride solution storage tank 5 respectively.

[0047] Furthermore, the steel test specimens are selected from at least one of Q345 steel, 20# steel, and 304 stainless steel.

[0048] In some specific embodiments, the steel hanging plate has a size of 30-40mm × 5-10mm × 2-5mm. In this embodiment, the steel hanging plate has a size of 30mm × 8mm × 3mm.

[0049] Furthermore, it also includes a booster pump 2 that transports CO2 from the CO2 storage tank 3 to the reactor 1; the booster pump 2 is connected to the reactor 1 and the CO2 storage tank 3 respectively via pipelines.

[0050] Furthermore, a first valve 8-1 is installed on the pipeline connecting the booster pump 2 and the reactor 1.

[0051] Furthermore, a second valve 8-2 and a first pressure sensor 9-1 are installed on the pipeline connecting the booster pump 2 and the CO2 storage tank 3;

[0052] Furthermore, it also includes a second pressure sensor 9-2 for collecting the pressure inside the CO2 storage tank 3.

[0053] Furthermore, the reactor 1 is connected to the sodium chloride solution storage tank 5 via a pipeline; a third valve 8-3 is installed on the pipeline connecting the reactor 1 and the sodium chloride solution storage tank 5.

[0054] Furthermore, it also includes a piston pump 4 for transporting sodium chloride solution from sodium chloride solution storage tank 5 to reaction vessel 1; piston pump 4 is connected to sodium chloride solution storage tank 5 via a pipeline; a fourth valve 8-4 is installed on the pipeline connecting piston pump 4 and sodium chloride solution storage tank 5.

[0055] Furthermore, it also includes an atomizing nozzle 7; the atomizing nozzle 7 is located at the material inlet of the reactor 1 and is connected to the pipeline connecting the reactor 1 to the booster pump 2 and the pipeline connecting the reactor 1 to the sodium chloride solution storage tank 5, and is used to atomize the material in the gas storage tank 3 and the sodium chloride solution storage tank 5 and transport it to the reactor 1.

[0056] Furthermore, the data acquisition system 6 includes a third pressure sensor 9-3 for acquiring the pressure inside the reactor 1 and an information acquisition mechanism for recording the information acquired by the third pressure sensor 9-3.

[0057] The method for establishing a corrosion rate indicator chart for CO2 pipeline steel in this embodiment includes the following steps:

[0058] (1) The steel test clips were sanded, solvent-cleaned, and dried; and in accordance with... Figure 2 The steel test bracket is installed in the reactor as shown.

[0059] (2) Vacuum the reactor, and then transfer the materials from the CO2 storage tank and the sodium chloride solution storage tank to the reactor for reaction;

[0060] (3) After the reaction is complete, calculate the corrosion rate according to formula (1);

[0061]

[0062] In equation (1), R corr The corrosion rate is expressed in mm / a; m is the initial mass of the steel test strip in g; m t S1 represents the mass of the steel test strip after the reaction, in grams; S2 represents the surface area of ​​the steel test strip, in centimeters. 2 ρ represents the density of the steel test strip, in g / cm³. 3 t represents the reaction time, in hours (h).

[0063] (4) Based on the calculated corrosion rate, the pressure, water content, and Cl inside the reactor are interpolated using a fitting interpolation method. - After concentration normalization, a corrosion rate characteristic map is plotted to obtain the corrosion rate indicator map of the CO2 pipeline steel.

[0064] Example 2

[0065] This embodiment uses the apparatus in Example 1 to test and obtain the corrosion rate variation curves of three steel materials—Q345 steel, 20# steel, and 304 stainless steel—with moisture content. Figure 3 ).

[0066] As can be seen from the figure, when the moisture content changes from 0.5% to 1%, the corrosion rate of Q345 steel changes from 0.0382 mm / a to 0.2646 mm / a; and that of 20# steel changes from 0.0468 mm / a to 0.2695 mm / a. The corrosion rate of both types of steel shows a significant acceleration. Since stainless steel itself has good corrosion resistance, the moisture content has little effect on the corrosion of 304 stainless steel.

[0067] Example 3:

[0068] This embodiment uses the apparatus in Example 1 to obtain the corrosion rate of three types of steel—Q345 steel, 20# steel, and 304 stainless steel—as a function of Cl. - Concentration change curve ( Figure 4 ).

[0069] As can be seen from the figure, for both Q345 steel and 20# steel, these two carbon steels, with the increase of Cl... - As the concentration gradually increases, the corrosion rate accelerates accordingly.

[0070] Example 4:

[0071] This embodiment uses the apparatus in Example 1 to obtain the corrosion rate variation curves of three types of steel—Q345 steel, 20# steel, and 304 stainless steel—with pressure. Figure 5 The testing process and corrosion rate calculation process are the same as in Example 2.

[0072] As can be seen from the figure, the corrosion rate of both Q345 steel and 20# steel decreases as the pressure gradually increases.

[0073] Example 5

[0074] This embodiment addresses the pressure, moisture content, and Cl in Examples 2-4. - The three factors affecting the corrosion rate of steel, namely concentration, were normalized, and a ternary contour phase diagram was drawn using fitting interpolation to obtain a corrosion rate indicator chart for CO2 pipeline steel, thus clarifying the effects of pressure, moisture content, and Cl- concentration. - The effect of concentration on the corrosion rate of three types of steel: Q345 steel, 20# steel, and 304 stainless steel. Figure 6-8 The moisture content is taken as 0.05%, 0.5%, 1%, and 2%, and the pressure is taken as 3.5 MPa, 5.5 MPa, and 7.5 MPa. - The concentration values ​​were 1000 mg / L, 3000 mg / L, and 5000 mg / L.

[0075] The formula used for normalization is as follows:

[0076]

[0077] In the formula: X represents the original data, X min X is the minimum value of the data. max This represents the maximum value of the data.

[0078] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An apparatus for establishing a corrosion rate indicator chart for steel transported via CO2 pipelines, characterized in that, It includes a steel test sample, a reaction vessel, a CO2 storage tank, a sodium chloride solution storage tank, and a data acquisition system; the steel test sample is installed in the reaction vessel; the reaction vessel is connected to the CO2 storage tank and the sodium chloride solution storage tank respectively.

2. The apparatus according to claim 1, characterized in that, The steel test specimens are selected from at least one of Q345 steel, 20# steel, and 304 stainless steel.

3. The apparatus according to claim 1, characterized in that, It also includes a booster pump that delivers CO2 from a CO2 storage tank to a reaction vessel; the booster pump is connected to the reaction vessel and the CO2 storage tank via pipelines. Preferably, a first valve is installed on the pipeline connecting the booster pump and the reactor; Preferably, a second valve and a first pressure sensor are installed on the pipeline connecting the booster pump and the CO2 storage tank; Preferably, it also includes a second pressure sensor for collecting the pressure inside the CO2 storage tank.

4. The apparatus according to claim 3, characterized in that, The reactor is connected to a sodium chloride solution storage tank via a pipeline; a third valve is installed on the pipeline connecting the reactor and the sodium chloride solution storage tank.

5. The apparatus according to claim 1, characterized in that, It also includes a piston pump for transporting sodium chloride solution from a sodium chloride solution storage tank to a reaction vessel; the piston pump is connected to the sodium chloride solution storage tank via a pipeline; a fourth valve is installed on the pipeline connecting the piston pump and the sodium chloride solution storage tank.

6. The apparatus according to claim 4, characterized in that, It also includes an atomizing nozzle; the atomizing nozzle is located at the material inlet of the reactor and is connected to the pipeline connecting the reactor to the booster pump and the pipeline connecting the reactor to the sodium chloride solution storage tank, for atomizing the material in the CO2 storage tank and the sodium chloride solution storage tank and conveying it to the reactor.

7. The apparatus according to claim 1, characterized in that, The data acquisition system includes a third pressure sensor for acquiring the pressure inside the reactor and an information acquisition mechanism for recording the information acquired by the third pressure sensor.

8. A method for establishing a corrosion rate indicator chart for CO2 pipeline steel based on the apparatus described in any one of claims 1-7, characterized in that, Includes the following steps: (1) Install the steel test clips into the reactor; (2) Vacuum the reactor, and then transfer the materials from the CO2 storage tank and the sodium chloride solution storage tank to the reactor for reaction; (3) After the reaction is complete, calculate the corrosion rate according to formula (1); In equation (1), R corr The corrosion rate is expressed in mm / a; m is the initial mass of the steel test strip in g; m t S1 represents the mass of the steel test strip after the reaction, in grams; S2 represents the surface area of ​​the steel test strip, in centimeters. 2 ρ represents the density of the steel test strip, in g / cm³. 3 t represents the reaction time, in hours (h). (4) Based on the calculated corrosion rate, the pressure, water content, and Cl inside the reactor are interpolated using a fitting interpolation method. - After concentration normalization, a corrosion rate characteristic map is plotted to obtain the corrosion rate indicator map of the CO2 pipeline steel.

9. The method according to claim 8, characterized in that, The steel test brackets are pretreated; Preferably, the pretreatment includes sanding, solvent cleaning, and drying.

10. The method according to claim 8, characterized in that, The reaction time is 150–200 h; Preferably, the pressure ranges from 3.5 to 7.5 MPa; Preferably, the Cl - The concentration range is 1000–5000 mg / L; Preferably, the moisture content ranges from 0.05% to 2%.

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