A corrosion inhibitor, a corrosion inhibitor composition for CO2 transport environments, its preparation method and application

Abstract

This invention relates to the field of corrosion and protection technology for chemical agents and metallic materials used in oil and gas fields, specifically to a corrosion inhibitor, a corrosion inhibitor composition for CO2 transport environments, its preparation method, and its application. The preparation method of the corrosion inhibitor includes: reacting benzylpiperazine, an aldehyde-containing compound, and a hydroxyl-containing compound in the presence of microwaves; the molar ratio of the benzylpiperazine, the aldehyde-containing compound, and the hydroxyl-containing compound is 1-1.7:1-1.4:1. The corrosion inhibitor prepared by the method of this invention contains multiple functional groups with excellent corrosion inhibition functions, and can form multiple adsorption centers such as triple bonds, N, and O on the metal surface. The corrosion inhibitor composition for CO2 transport environments prepared using this corrosion inhibitor, along with modifiers, dispersants, solvents, and other components, can achieve highly efficient resistance to high-concentration CO2 corrosion.

Description

Technical Field

[0001] This invention relates to the field of corrosion and protection technology of chemical agents and metallic materials used in oil and gas fields, specifically to a corrosion inhibitor, a corrosion inhibitor composition for CO2 transport environments, its preparation method, and its application. Background Technology

[0002] The petrochemical industry is the fourth largest source of CO2 emissions after power, steel, and cement. Carbon capture, utilization, and storage (CCUS) technology is a cutting-edge technology that collects CO2 emitted from coal-fired power plants and other industries, storing it in various forms or utilizing it as a resource to prevent its release into the atmosphere. It represents the most promising direction for emission reduction and carbon sequestration, encompassing the capture, transportation, storage, and use of carbon. CO2 transportation plays a crucial role in the application of CCUS technology. Generally, CO2 pipeline transportation operates at temperatures ranging from 4 to 50°C and pressures from 5 to 20 MPa. The critical temperature and pressure of CO2 are 31.04°C and 7.38 MPa, respectively; therefore, CO2 can be transported in gaseous, liquid, dense-phase, or supercritical states via pipelines.

[0003] Before CO2 enters pipelines, it is generally captured and purified using pre-combustion, post-combustion, or oxygen-enriched combustion technologies. However, thoroughly purifying large amounts of CO2 poses challenges to existing capture technologies and their energy consumption, and is not economical. Therefore, the CO2 gas stream transported in pipelines contains a certain amount of impurities such as SO2, NO2, H2S, O2, and H2O. During CO2 pipeline transportation, CO2 and its impurities dissolve in the aqueous phase, forming a multi-media coupled system. In particular, when the water content in the CO2 exceeds the critical water content, it causes severe corrosion to carbon steel metal pipelines. In such high-CO2 environments, the performance of conventional CO2 corrosion inhibitors in oil and gas fields is poor and cannot meet the requirements for corrosion control. Therefore, it is necessary to develop corrosion inhibitors resistant to high concentrations of CO2.

[0004] Patent CN 107699900 B discloses a CO2 corrosion inhibitor for oil and gas field gathering and transportation pipelines and its preparation method, applicable to the corrosive environment of gathering and transportation pipelines with high Cl- content, high salinity, and high temperature. The corrosion inhibitor contains 44-55 parts by weight of an imidazoline-benzoic acid derivative, 5-10 parts by weight of thiourea, 10-18 parts by weight of water, 5-8 parts by weight of alkylphenol polyoxyethylene ether OP-10, 1-2 parts by weight of triethanolamine, 2-5 parts by weight of phenoxymethyl ether O-25, and 7-28 parts by weight of ethylene glycol monobutyl ether; the imidazoline-benzoic acid derivative is synthesized by reacting imidazoline and benzoic acid. Due to the relatively low partial pressure and content of CO2 in oil and gas field gathering and transportation pipelines, this corrosion inhibitor is not suitable for CO2 transportation environments.

[0005] Patent application CN 1410595A discloses a water-soluble corrosion inhibitor for suppressing CO2 corrosion of carbon steel and its preparation method. The inhibitor comprises: 15-40% (by weight) rosin amine, 5-30% (by weight) monobasic acid, 5-30% (by weight) thiourea and thiourea derivatives, and 10-50% (by weight) solvent. It can effectively inhibit CO2 corrosion of carbon steel pipelines in CO2-containing environments of oil fields over a wide temperature range. However, the corrosion environment of oil and gas fields is completely different from that of CO2 transport pipelines. Oil and gas fields primarily experience CO2-saturated water systems, with water as the main component, and corrosion mainly occurs at low temperatures and low pressures in oil and gas transport systems and at high temperatures and high pressures during oil and gas extraction. CO2 transport, on the other hand, involves a CO2 system containing small amounts of water and impurities, with CO2 as the main component, primarily existing at low temperatures and high pressures. Therefore, corrosion inhibitors developed for oil and gas field environments are not suitable for the high-CO2-content corrosive environment of CO2 transport.

[0006] Patent application CN1818138A discloses a corrosion inhibitor for controlling carbon dioxide corrosion, containing 1-70 wt% oleic acid imidazoline; 0.01-30 wt% thiourea; 0-60 wt% water; 0-30 wt% polyoxyethylene ether; and 0-40 wt% isopropanol. The provided corrosion inhibitor exhibits good CO2 corrosion control effects. However, based on its research background, this corrosion inhibitor is suitable for CO2 corrosion control in oil and gas field systems, but not for the high-CO2 corrosive environment of CO2 transportation.

[0007] Patent application CN106588776A provides a simple preparation method for a corrosion inhibitor that has a good corrosion inhibition effect in environments with high H2S / CO2 content. The method involves reacting long-chain fatty acids with polyamines to form high molecular weight imidazoline and amide molecules, and then combining aromatic acids with aliphatic cyclic amines to synthesize amides. It is mainly targeted at corrosive environments where H2S corrosion is dominant, such as the development of oil and gas wells with high H2S / CO2 content. Summary of the Invention

[0008] The purpose of this invention is to overcome the problem of poor corrosion inhibition effect of corrosion inhibitors in high-concentration CO2 corrosive environments, and to provide a corrosion inhibitor, a corrosion inhibition composition for CO2 transport environments, its preparation method and application.

[0009] To achieve the above objectives, the present invention provides a method for preparing a corrosion inhibitor, the method comprising: reacting benzylpiperazine, a compound containing an aldehyde group, and a compound containing a hydroxyl group in the presence of microwaves;

[0010] The molar ratio of the benzylpiperazine, the aldehyde-containing compound, and the hydroxyl-containing compound is 1-1.7:1-1.4:1.

[0011] Preferably, the molar ratio of the benzylpiperazine, the aldehyde-containing compound, and the hydroxyl-containing compound is 1.07-1.26:1-1.18:1.

[0012] Preferably, the aldehyde-containing compound is directly derived from aldehyde compounds and / or obtained by heating and decomposing paraformaldehyde.

[0013] Preferably, the aldehyde compound is selected from monoaldehydes and / or dialdehydes;

[0014] Preferably, the monohydric aldehyde is selected from C1-C5 monohydric aldehydes; more preferably, it is formaldehyde and / or acetaldehyde;

[0015] Preferably, the dialdehyde is selected from C2-C5 dialdehydes, and more preferably glutaraldehyde.

[0016] Preferably, the hydroxyl-containing compound is selected from alkynols and / or alcoholamines.

[0017] Preferably, the alkynol is selected from monoalkynols and / or dialkynols;

[0018] Preferably, the monoalkynol is selected from at least one of propynol, methylpentynol, and 2-butyn-1-ol;

[0019] Preferably, the dialkynol is 1,4-butynediol.

[0020] Preferably, the alkanolamine is selected from one or more of diethanolamine, ethanolamine, triethanolamine and N-methyldiethanolamine.

[0021] Preferably, the power of the microwave is 500 to 800 watts.

[0022] Preferably, the reaction time is 6 to 12 minutes.

[0023] A second aspect of the present invention provides a corrosion inhibitor prepared by the method described above.

[0024] A third aspect of the present invention provides a corrosion inhibitor composition for use in CO2 transport environments, the composition comprising a corrosion inhibitor, an optional modifier, a dispersant, and a solvent;

[0025] The corrosion inhibitor is the corrosion inhibitor described above;

[0026] The total weight of the composition is 100 parts by weight, the amount of the corrosion inhibitor is 35-60 parts by weight, the amount of the modifier is 0-15 parts by weight, the amount of the dispersant is 5-10 parts by weight, and the amount of the solvent is 15-40 parts by weight.

[0027] Preferably, the total weight of the composition is 100 parts by weight, the amount of the corrosion inhibitor is 40-58 parts by weight, the amount of the modifier is 0-12 parts by weight, the amount of the dispersant is 6-8 parts by weight, and the amount of the solvent is 22-40 parts by weight.

[0028] Preferably, the modifier is selected from one or more of potassium iodide, sodium iodide, cuprous iodide and Na2S2O3;

[0029] Preferably, the dispersant is selected from one or more of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, polyoxyethylene fatty alcohol ether, and Span-20;

[0030] Preferably, the solvent is selected from one or more of methanol, ethanol, ethylene glycol, propylene glycol, butanediol, isopropanol, diethyl ether, and water.

[0031] The fourth aspect of the present invention provides the application of the corrosion inhibitor described above or the corrosion inhibitor composition described above for CO2 transport environments in the process of transporting CO2 in pipelines.

[0032] Preferably, when CO2 is transported in a supercritical state, the corrosion inhibitor used for the CO2 transport environment contains a modifier.

[0033] The corrosion inhibitor prepared by the method described in this invention contains multiple functional groups with excellent corrosion inhibition functions, and can form multiple adsorption centers such as triple bonds, N, and O on the metal surface. The corrosion inhibitor composition prepared using this corrosion inhibitor, along with modifiers, dispersants, solvents, and other components, for use in CO2 transport environments can achieve highly efficient resistance to high-concentration CO2 corrosion.

[0034] Existing corrosion inhibitors for oil and gas fields are ineffective in high-concentration CO2 corrosive environments. Compared with existing technologies, this invention provides a corrosion inhibitor composition for CO2 transportation environments that exhibits highly efficient resistance to high-concentration CO2 corrosion, and is particularly suitable for environments containing high concentrations of CO2 in CO2 transportation pipelines. The application process is simple, the dosage is low, and it has a wide range of applicability. Detailed Implementation

[0035] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0036] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0037] The present invention provides a method for preparing a corrosion inhibitor, the method comprising: reacting benzylpiperazine, a compound containing an aldehyde group and a compound containing a hydroxyl group in the presence of microwaves; wherein the molar ratio of the benzylpiperazine, the compound containing an aldehyde group and the compound containing a hydroxyl group is 1-1.7:1-1.4:1.

[0038] The corrosion inhibitor described in this invention is synthesized using a microwave method, requiring only one step to obtain the target product. Because microwaves can penetrate deep into the interior of materials, rather than relying on the material's own heat conduction, the entire heating process can be completed in only one-tenth to one-hundredth of the time required by conventional methods. This method offers advantages such as rapid heating, high thermal energy utilization, and energy savings. The corrosion inhibitor synthesized using this method exhibits excellent corrosion inhibition performance.

[0039] To obtain a corrosion inhibitor with excellent corrosion inhibition properties, the benzylpiperazine, the aldehyde-containing compound, and the hydroxyl-containing compound are all indispensable. In a preferred embodiment, the molar ratio of the benzylpiperazine, the aldehyde-containing compound, and the hydroxyl-containing compound can be 1.07-1.26:1-1.18:1.

[0040] In a preferred embodiment, the aldehyde-containing compound is directly derived from aldehyde compounds and / or obtained by the thermal decomposition of paraformaldehyde.

[0041] More preferably, the aldehyde compound is selected from monoaldehydes and / or dialdehydes.

[0042] Preferably, the monohydric aldehyde is selected from C1-C5 monohydric aldehydes; more preferably, it is formaldehyde and / or acetaldehyde;

[0043] Preferably, the dialdehyde is selected from C2-C5 dialdehydes, and more preferably glutaraldehyde.

[0044] More preferably, the dialdehyde is selected from C2-C5 dialdehydes, and more preferably glutaraldehyde.

[0045] Preferably, the degree of polymerization n of the paraformaldehyde is 8 to 10.

[0046] In a preferred embodiment, the hydroxyl-containing compound is selected from alkynols and / or alcoholamines.

[0047] In the method described in this invention, alkynyl alcohols containing both a triple bond and an -OH- group are used as raw materials, and the prepared corrosion inhibitors exhibit excellent corrosion inhibition properties. More preferably, the alkynyl alcohols are selected from monoalkynyl alcohols and / or dialkynyl alcohols;

[0048] More preferably, the monoalkynol is selected from at least one of propynol, methylpentynol, and 2-butyn-1-ol;

[0049] More preferably, the dialkynol is 1,4-butynediol.

[0050] In the method described in this invention, an N-containing organic amine containing one or more hydroxyl groups is used as a raw material to prepare a corrosion inhibitor with excellent corrosion inhibition properties. More preferably, the amine is selected from one or more of diethanolamine, ethanolamine, triethanolamine, and N-methyldiethanolamine.

[0051] In one specific embodiment, when benzylpiperazine, acetaldehyde, and propynyl alcohol are used as raw materials to prepare the corrosion inhibitor, the reaction process is as follows:

[0052]

[0053] In one specific embodiment, when benzylpiperazine, formaldehyde, and ethanolamine are used as raw materials to prepare the corrosion inhibitor, the reaction process is as follows:

[0054]

[0055] In one specific embodiment, when benzylpiperazine, glutaraldehyde, and 2-butynediol are used as raw materials to prepare the corrosion inhibitor, the reaction process is as follows:

[0056]

[0057] In one specific embodiment, when benzylpiperazine, paraformaldehyde (which decomposes to yield formaldehyde), and N-methyldiethanolamine are used as raw materials to prepare the corrosion inhibitor, the reaction process is as follows:

[0058]

[0059] In one specific embodiment, when benzylpiperazine, formaldehyde, and diethanolamine are used as raw materials to prepare the corrosion inhibitor, the reaction process is as follows:

[0060]

[0061] In one specific embodiment, when benzylpiperazine, paraformaldehyde (which decomposes to yield formaldehyde), and methylpentynol are used as raw materials to prepare the corrosion inhibitor, the reaction process is as follows:

[0062]

[0063] In one specific embodiment, when benzylpiperazine, glutaraldehyde, and triethanolamine are used as raw materials to prepare the corrosion inhibitor, the reaction process is as follows:

[0064]

[0065] In one specific embodiment, when benzylpiperazine, acetaldehyde, and 2-butynediol are used as raw materials to prepare the corrosion inhibitor, the reaction process is as follows:

[0066]

[0067] In one specific embodiment, when benzylpiperazine, formaldehyde, and diethanolamine are used as raw materials to prepare the corrosion inhibitor, the reaction process is as follows:

[0068]

[0069] In the method described in this invention, in order to ensure that the reaction proceeds quickly, smoothly and efficiently, it is necessary to reasonably control the microwave conditions and reaction time.

[0070] In a preferred embodiment, the microwave radiation power can be 500 to 800 watts. Specifically, the microwave radiation power can be 500 watts, 550 watts, 600 watts, 650 watts, 700 watts, 750 watts, or 800 watts.

[0071] In a preferred embodiment, the reaction time is 6-12 minutes. Specifically, the reaction time can be 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, or 12 minutes.

[0072] A third aspect of the present invention provides a corrosion inhibitor composition for use in CO2 transport environments, the composition comprising a corrosion inhibitor, an optional modifier, a dispersant, and a solvent;

[0073] The corrosion inhibitor is the corrosion inhibitor described above;

[0074] The total weight of the composition is 100 parts by weight, the amount of the corrosion inhibitor is 35-60 parts by weight, the amount of the modifier is 0-15 parts by weight, the amount of the dispersant is 5-10 parts by weight, and the amount of the solvent is 15-40 parts by weight.

[0075] More preferably, the total weight of the composition is 100 parts by weight, the amount of the corrosion inhibitor is 40-58 parts by weight, the amount of the modifier is 0-12 parts by weight, the amount of the dispersant is 6-8 parts by weight, and the amount of the solvent is 22-40 parts by weight.

[0076] In this invention, the corrosion inhibitor composition for CO2 transport environments can be obtained simply by mixing raw materials without the need for a complex preparation process.

[0077] In this invention, the addition of a modifier can change the excess charge on the metal surface, which is beneficial to further improve the corrosion inhibition effect.

[0078] In a preferred embodiment, the modifier is selected from one or more of potassium iodide, sodium iodide, cuprous iodide, and Na2S2O3.

[0079] In a preferred embodiment, the dispersant is selected from one or more of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, polyoxyethylene fatty alcohol ether, and Span-20.

[0080] In this invention, the solvent can be any conventional choice in the art. In a preferred embodiment, the solvent is selected from one or more of methanol, ethanol, ethylene glycol, propylene glycol, butanediol, isopropanol, diethyl ether, and water.

[0081] In this invention, the corrosion inhibitor, modifier, dispersant and solvent are mixed in a specific ratio to have the function of resisting high concentration CO2 corrosion.

[0082] The fourth aspect of the present invention provides the application of the corrosion inhibitor described above or the corrosion inhibitor composition described above for CO2 transport environments in the process of transporting CO2 in pipelines.

[0083] CO2 can be transported in a supercritical state, gaseous state, dense phase, or liquid state, and the corrosion inhibitors for CO2 transport environments described in this invention can be used to protect the transport pipelines.

[0084] When CO2 is transported in a supercritical state, the corrosion inhibition effect is better when using a corrosion inhibitor containing a modifier for the CO2 transport environment. Therefore, in a preferred embodiment, when CO2 is transported in a supercritical state, the corrosion inhibitor for the CO2 transport environment contains a modifier.

[0085] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto.

[0086] Unless otherwise specified, all reagents used in the following examples are commercially available products.

[0087] Example 1

[0088] Preparation process of corrosion inhibitor:

[0089] 0.12 mol benzylpiperazine, 0.11 mol acetaldehyde and 0.11 mol propargyl alcohol were reacted under microwave irradiation at 700 W for 11 minutes, with a final temperature of 285 °C, to obtain corrosion inhibitor A1.

[0090] Preparation process of corrosion inhibitor compositions suitable for CO2 transport environments:

[0091] 48 parts by weight of corrosion inhibitor (A1), 10 parts by weight of KI, 8 parts by weight of alkylphenol polyoxyethylene ether, and 34 parts by weight of ethanol were stirred and mixed to obtain corrosion inhibitor composition S1 suitable for CO2 transport environments.

[0092] Example 2

[0093] Preparation process of corrosion inhibitor:

[0094] 0.13 mol benzylpiperazine, 0.13 mol formaldehyde and 0.11 mol ethanolamine were reacted under microwave irradiation at 750 W for 10 minutes, with the final temperature being 280 °C, to obtain corrosion inhibitor A2.

[0095] Preparation process of corrosion inhibitor compositions suitable for CO2 transport environments:

[0096] 50 parts by weight of corrosion inhibitor formula (A2), 8 parts by weight of NaI, 6 parts by weight of fatty alcohol polyoxyethylene ether, and 36 parts by weight of water are stirred and mixed to obtain corrosion inhibitor composition S2 suitable for CO2 transport environments.

[0097] Example 3

[0098] Preparation process of corrosion inhibitor:

[0099] 0.14 mol benzylpiperazine, 0.12 mol glutaraldehyde and 0.12 mol 2-butynediol were reacted under microwave irradiation at 800 W for 9 minutes, with the final temperature reaching 285 °C, to obtain corrosion inhibitor A3.

[0100] Preparation process of corrosion inhibitor compositions suitable for CO2 transport environments:

[0101] 46 parts by weight of corrosion inhibitor (A3), 12 parts by weight of cuprous iodide, 8 parts by weight of polyoxyethylene fatty alcohol ether, 15 parts by weight of methanol, and 19 parts by weight of water are stirred and mixed to obtain corrosion inhibitor composition S3 suitable for CO2 transport environments.

[0102] Example 4

[0103] Preparation process of corrosion inhibitor:

[0104] 0.13 mol benzylpiperazine, paraformaldehyde (degree of polymerization 9, providing 0.13 mol of formaldehyde), and 0.12 mol N-methyldiethanolamine were reacted under microwave irradiation at 500 W for 12 minutes, with a final temperature of 270 °C, to obtain corrosion inhibitor A4.

[0105] Preparation process of corrosion inhibitor compositions suitable for CO2 transport environments:

[0106] 55 parts by weight of corrosion inhibitor (A4), 8 parts by weight of Span-20, and 37 parts by weight of isopropanol were stirred and mixed to obtain corrosion inhibitor composition S4 suitable for CO2 transport environments.

[0107] Example 5

[0108] Preparation process of corrosion inhibitor:

[0109] 0.15 mol benzylpiperazine, 0.13 mol formaldehyde and 0.12 mol diethanolamine were reacted under microwave irradiation at 650 watts for 11 minutes, with a final temperature of 275 °C, to obtain corrosion inhibitor A5.

[0110] Preparation process of corrosion inhibitor compositions suitable for CO2 transport environments:

[0111] 52 parts by weight of corrosion inhibitor (A5), 10 parts by weight of Na2S2O3, 7 parts by weight of alkylphenol polyoxyethylene ether, 10 parts by weight of ethanol and 21 parts by weight of water are stirred and mixed to obtain corrosion inhibitor composition S5 suitable for CO2 transport environments.

[0112] Example 6

[0113] Preparation process of corrosion inhibitor:

[0114] 0.17 mol benzylpiperazine, paraformaldehyde (degree of polymerization 9, providing 0.14 mol formaldehyde), and 0.13 mol methylpentynol were reacted under microwave irradiation at 600 W for 12 minutes, with a final temperature of 280 °C, to obtain corrosion inhibitor A6.

[0115] Preparation process of corrosion inhibitor compositions suitable for CO2 transport environments:

[0116] 58 parts by weight of corrosion inhibitor (A6), 15 parts by weight of NaI, 10 parts by weight of alkylphenol polyoxyethylene ether, 5 parts by weight of ethylene glycol, and 12 parts by weight of isopropanol were stirred and mixed to obtain corrosion inhibitor composition S6 suitable for CO2 transport environments.

[0117] Example 7

[0118] Preparation process of corrosion inhibitor:

[0119] 0.18 mol benzylpiperazine, 0.15 mol glutaraldehyde and 0.13 mol triethanolamine were reacted under microwave irradiation at 750 W for 10 minutes, with the final temperature being 280 °C, to obtain corrosion inhibitor A7.

[0120] Preparation process of corrosion inhibitor compositions suitable for CO2 transport environments:

[0121] The corrosion inhibitor (A7), 15 parts by weight of cuprous iodide, 10 parts by weight of fatty alcohol polyoxyethylene ether, 10 parts by weight of diethyl ether, and 30 parts by weight of water are stirred and mixed to obtain the corrosion inhibitor composition S7 suitable for CO2 transport environments.

[0122] Example 8

[0123] Preparation process of corrosion inhibitor:

[0124] 0.16 mol benzylpiperazine was reacted with 0.1 mol acetaldehyde and 0.1 mol 2-butynediol under microwave irradiation at 500 W for 12 minutes, with the final temperature being 270 °C, to obtain corrosion inhibitor A8.

[0125] Preparation process of corrosion inhibitor compositions suitable for CO2 transport environments:

[0126] 45 parts by weight of corrosion inhibitor (A8), 13 parts by weight of NaI, 9 parts by weight of polyoxyethylene fatty alcohol ether, 10 parts by weight of propylene glycol, and 23 parts by weight of water are stirred and mixed to obtain corrosion inhibitor composition S8 suitable for CO2 transport environments.

[0127] Example 9

[0128] Preparation process of corrosion inhibitor:

[0129] 0.17 mol benzylpiperazine, 0.14 mol formaldehyde and 0.1 mol diethanolamine were reacted under microwave irradiation at 550 W for 10 minutes, with the final temperature being 265 °C, to obtain corrosion inhibitor A9.

[0130] Preparation process of corrosion inhibitor compositions suitable for CO2 transport environments:

[0131] 56 parts by weight of corrosion inhibitor (A9), 14 parts by weight of Na2S2O3, 5 parts by weight of Span-20, and 25 parts by weight of ethanol were stirred and mixed to obtain corrosion inhibitor composition S9 suitable for CO2 transport environments.

[0132] Example 10

[0133] Preparation process of corrosion inhibitor compositions suitable for CO2 transport environments:

[0134] 58 parts by weight of corrosion inhibitor (A1), 8 parts by weight of alkylphenol polyoxyethylene ether, and 34 parts by weight of ethanol were stirred and mixed to obtain a corrosion inhibitor composition S10 suitable for CO2 transport environments.

[0135] Comparative Example 1

[0136] The composition was obtained by stirring and mixing 63 parts by weight of corrosion inhibitor (A1), 15 parts by weight of KI, 8 parts by weight of alkylphenol polyoxyethylene ether, and 14 parts by weight of ethanol.

[0137] Comparative Example 2

[0138] The composition was obtained by stirring and mixing 32 parts by weight of corrosion inhibitor (A1), 15 parts by weight of KI, 10 parts by weight of alkylphenol polyoxyethylene ether, and 43 parts by weight of ethanol.

[0139] Comparative Example 3

[0140] 0.24 mol benzylpiperazine, 0.15 mol acetaldehyde and 0.13 mol propargyl alcohol were reacted under microwave irradiation at 700 W for 11 minutes, with a final temperature of 285 °C, to obtain corrosion inhibitor D1.

[0141] The composition was obtained by stirring and mixing 48 parts by weight of corrosion inhibitor (D1), 10 parts by weight of KI, 8 parts by weight of alkylphenol polyoxyethylene ether, and 34 parts by weight of ethanol.

[0142] Comparative Example 4

[0143] 48 parts by weight of benzylpiperazine, 10 parts by weight of KI, 8 parts by weight of alkylphenol polyoxyethylene ether, and 34 parts by weight of ethanol were stirred and mixed.

[0144] Comparative Example 5

[0145] 48 parts by weight of propynyl alcohol, 10 parts by weight of KI, 8 parts by weight of alkylphenol polyoxyethylene ether, and 34 parts by weight of ethanol were stirred and mixed.

[0146] Test Example 1

[0147] The corrosion inhibition effects of the compositions prepared in the above examples and comparative examples were tested, and the test results are shown in Table 1. The test method refers to SY / T5273-2014 (Performance Inhibitors and Evaluation Methods for Oilfield Produced Water Treatment), and the material is X65 low carbon steel.

[0148] Table 1

[0149]

[0150]

[0151] As can be seen from Table 1, the corrosion inhibitor composition described in this invention can effectively slow down the corrosion rate in high-concentration CO2 transportation environments.

[0152] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a corrosion inhibitor, characterized in that, The method includes reacting benzylpiperazine, an aldehyde-containing compound, and a hydroxyl-containing compound in the presence of microwaves; The molar ratio of the benzylpiperazine, the aldehyde-containing compound, and the hydroxyl-containing compound is 1-1.7:1-1.4:1; The aldehyde-containing compound is directly derived from aldehyde compounds and / or obtained by heating and decomposing paraformaldehyde; the aldehyde compound is selected from monoaldehydes and / or dialdehydes, the monoaldehyde is selected from C1-C5 monoaldehydes, and the dialdehyde is selected from C2-C5 dialdehydes. The hydroxyl-containing compound is selected from alkynols and / or alkanolamines; the alkynol is selected from monoalkynols and / or dialkynols, wherein the monoalkynol is selected from at least one of propynol, methylpentynol, and 2-butyn-1-ol, and the dialkynol is 1,4-butynediol; the alkanolamine is selected from one or more of diethanolamine, ethanolamine, triethanolamine, and N-methyldiethanolamine.

2. The method according to claim 1, characterized in that, The molar ratio of the benzylpiperazine, the aldehyde-containing compound, and the hydroxyl-containing compound is 1.07-1.26:1-1.18:

1.

3. The method according to claim 1, characterized in that, The monoaldehyde is selected from formaldehyde and / or acetaldehyde.

4. The method according to claim 1, characterized in that, The dialdehyde is glutaraldehyde.

5. The method according to claim 1, characterized in that, The power of the microwave is 500 to 800 watts.

6. The method according to claim 1 or 5, characterized in that, The reaction time is 6 to 12 minutes.

7. The corrosion inhibitor prepared by the method according to any one of claims 1-6.

8. A corrosion inhibitor composition for use in CO2 transport environments, characterized in that, The composition contains a corrosion inhibitor, optional modifier, dispersant and solvent; The corrosion inhibitor is the corrosion inhibitor according to claim 7; The total weight of the composition is 100 parts by weight, the amount of the corrosion inhibitor is 35-60 parts by weight, the amount of the modifier is 0-15 parts by weight, the amount of the dispersant is 5-10 parts by weight, and the amount of the solvent is 15-40 parts by weight. The modifier is selected from one or more of potassium iodide, sodium iodide, cuprous iodide and Na2S2O3; The dispersant is selected from one or more of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, polyoxyethylene fatty alcohol ether, and Span-20; The solvent is selected from one or more of methanol, ethanol, ethylene glycol, propylene glycol, butanediol, isopropanol, diethyl ether, and water.

9. The corrosion inhibitor composition for CO2 transport environments according to claim 8, characterized in that, The total weight of the composition is 100 parts by weight, the amount of the corrosion inhibitor is 40-58 parts by weight, the amount of the modifier is 0-12 parts by weight, the amount of the dispersant is 6-8 parts by weight, and the amount of the solvent is 22-40 parts by weight.

10. The application of the corrosion inhibitor of claim 7 or the corrosion inhibitory composition for CO2 transport environments according to any one of claims 8-9 in the process of transporting CO2 through pipelines.

11. The application according to claim 10, characterized in that, When CO2 is transported in a supercritical state, the corrosion inhibitor composition for the CO2 transport environment contains a modifier.

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