Environmentally friendly compounds and intermediates of function-integrated molecular construction and methods of preparation and use

Abstract

The application relates to the technical field of key materials for corrosion prevention in ocean engineering, in particular to an environmentally-friendly compound and intermediate of functionally-integrated molecular construction, a preparation method and application. The compound is shown in formula I, the compound has high-efficiency and stable corrosion inhibition performance, has scale inhibition and bactericidal characteristics, and is suitable for complex corrosion environments in oil and gas fields. The formula reduces the dependence on traditional chemical reagents, reduces production cost, shows excellent effects in extreme corrosion environments, prolongs the service life of equipment, and improves production safety. In the formula,

Description

Technical Field

[0001] This invention relates to the field of key materials technology for corrosion protection in marine engineering, and more specifically, to an environmentally friendly compound with integrated functional molecular structure, an intermediate, a preparation method, and an application. Background Technology

[0002] Oil and gas fields exist in corrosive conditions characterized by high temperatures and high acidity, posing a significant obstacle to the safe and reliable operation of equipment. During oil extraction and transportation, equipment, pipelines, and other materials primarily made of metal frequently encounter a series of problems. One major issue is pipeline and equipment corrosion, which leads to substantial economic losses, high costs, environmental pollution, and resource waste. As oil and gas exploration and development continue, these problems are becoming increasingly prevalent.

[0003] Corrosion inhibitors are widely considered one of the most effective strategies for reducing steel corrosion due to their economy, high efficiency, and ease of use. They remain a primary corrosion prevention method used in oilfields both domestically and internationally. However, traditional corrosion inhibitors exhibit biological and environmental toxicity, leading to increasingly prominent problems. Previous corrosion inhibitors were often compounded, such as those combined with bactericides, to achieve corrosion inhibition and bactericidal effects. However, this often involved the use of hazardous chemicals, further contributing to environmental harm.

[0004] Therefore, the development of low-toxicity, environmentally friendly green biological corrosion inhibitors has become a current research hotspot. To reduce the amount of chemicals used, researchers are looking to synthesize a corrosion inhibitor that integrates multiple functions such as corrosion inhibition, bactericidal action, and scale inhibition, seeking more effective, economical, and environmentally friendly anti-corrosion solutions to improve the safety and production efficiency of oil and gas field equipment. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned defects and deficiencies in the prior art and to provide an environmentally friendly compound with an integrated functional molecular structure.

[0006] Another object of the present invention is to provide a method for preparing the environmentally friendly compound having a functionally integrated molecular structure.

[0007] Another object of the present invention is to provide the application of the environmentally friendly compound having a functionally integrated molecular structure.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] An environmentally friendly compound with a functionally integrated molecular structure, the compound being shown in Formula 1.

[0010]

[0011] Formula 1

[0012] In the formula,

[0013] .

[0014] A method for preparing the compound described above:

[0015] A1: Preparation of benzimidazole matrix: Lauric acid and o-phenylenediamine were reacted in the presence of solvent under nitrogen protection and by gradient temperature increase to obtain benzimidazole compound;

[0016] A2: Synthesis of intermediate I: The benzimidazole compound obtained in step A1 was dissolved in an organic solvent with sodium hydroxide. After stirring at 55-65℃, epichlorohydrin was added to continue the reaction. After purification, intermediate I containing hydroxyl groups was obtained.

[0017] A3: Synthesis of intermediate II: Intermediate I and acryloyl chloride were mixed and dissolved in an organic solvent, and the system was adjusted to react at 45-55℃ under alkaline conditions to obtain intermediate II containing double bonds;

[0018] A4: Preparation of the final product: Intermediate II was mixed with CHPS-Na and subjected to a quaternization reaction at 75-85℃, and the target compound was obtained after purification.

[0019] In step A1, lauric acid and o-phenylenediamine are mixed in a molar ratio of 1:1.1 to 1.3, and xylene is used as the solvent.

[0020] In step A1, the gradient temperature reaction is carried out in the first stage at 155-165℃ for 3.5-4.5 hours, and in the second stage at 215-225℃ for 2.5-3.5 hours. After the reaction is completed, the solvent is removed by vacuum distillation to obtain the benzimidazole compound.

[0021] In step A2, the benzimidazole compound obtained in step A1 is mixed with sodium hydroxide in a molar ratio of 1:1.0 to 1.1; in step A3, the intermediate I is mixed with acryloyl chloride in a molar ratio of 1:1.0 to 1.05.

[0022] In step A3, the system is adjusted with sodium hydroxide, wherein the volume ratio of sodium hydroxide solution to organic solution is 1.5~2:1.

[0023] The organic solvents used in steps A2 and A3 may be the same or different and may be selected from one or more of xylene, dimethyl sulfoxide, dichloromethane, and ethyl acetate.

[0024] In step A4, the amount of intermediate II and CHPS-Na is used in a molar ratio of 1:1 to 1.1.

[0025] Application of a compound in the preparation of a multifunctional corrosion inhibitor in the oil and gas field (60-100°C).

[0026] An intermediate for preparing the aforementioned compound, the intermediate having the structure shown below.

[0027] .

[0028] The beneficial effects of this invention are:

[0029] The environmentally friendly compound constructed by the present invention, which integrates functions, can be used as a corrosion inhibitor in oil and gas fields. It is a novel corrosion inhibitor based on the molecular design of benzimidazole matrix structure. Through the fine organic synthesis of benzimidazole structure, a variety of functional groups such as hydroxyl and sulfonic acid groups were successfully introduced, thereby significantly enhancing its performance diversity and application potential.

[0030] The core objective of this invention is to establish a highly efficient and stable corrosion inhibition system to address the corrosion problems of metal equipment under high temperature and extreme environments during oil and gas field extraction. This corrosion inhibitor not only possesses excellent corrosion inhibition performance but also combines scale inhibition and bactericidal properties, thus achieving multifunctional integration in a single product and significantly improving its applicability and efficiency in complex industrial environments.

[0031] Furthermore, this novel corrosion inhibitor represents a significant breakthrough in formulation design, reducing reliance on various traditional chemical reagents. This not only lowers production costs but also minimizes potential environmental impact, aligning with the trend of green development in modern industry. In performance tests conducted in extreme corrosive environments unique to oil and gas fields, including temperatures exceeding 60°C, acidity, and the presence of sulfate-reducing bacteria (SRB), this corrosion inhibitor demonstrated remarkable performance, far surpassing traditional corrosion inhibitors. It effectively extends the service life of oil and gas field equipment, reduces maintenance costs, and simultaneously improves production safety.

[0032] This invention not only provides new ideas and methods for the development of corrosion inhibitors for oil and gas fields, but also makes a positive contribution to promoting the sustainable development of the oil and gas field development industry. Attached Figure Description

[0033] Figure 1 The present invention provides a synthetic route for an environmentally friendly corrosion inhibitor with an integrated functional molecular structure.

[0034] Figure 2 The structural characterization diagram shows the environmentally friendly corrosion inhibitor constructed using the functionally integrated molecular structure of this invention.

[0035] Figure 3 The figure shows the static scale inhibition test results of the environmentally friendly corrosion inhibitor with integrated functional molecular structure of the present invention.

[0036] Figure 4 The image shows the fluorescence microscopy results of the environmentally friendly corrosion inhibitor constructed using the functional integrated molecular structure of this invention. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in this technical field.

[0038] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0039] Example 1:

[0040] The process of compound synthesis is as follows Figure 1 ,

[0041] A1: Lauric acid and o-phenylenediamine were mixed in a three-necked flask at a molar ratio of 1:1.1. Xylene was added as a water-carrying agent. Nitrogen gas was bubbled through the mixture for protection, and the reaction was then heated to reflux with stirring. The amidation reaction was continued at 160°C for 3.5 hours, then the temperature was increased to 215°C and the reaction continued for another 2.5 hours. After cooling, the desired benzimidazole matrix was obtained by vacuum distillation.

[0042] A2: Dimethyl sulfoxide was mixed with sodium hydroxide in a 1:1 molar ratio and stirred at 55°C for 1 hour. Then epichlorohydrin was added, and the mixture was stirred for another 12 hours. After the reaction was complete, the mixture was cooled to room temperature, poured into cold water, filtered, and purified to yield intermediate I.

[0043] A3: Dissolve intermediate product I in dimethyl sulfoxide solution, mix intermediate product I with acryloyl chloride at a molar ratio of 1:1.05, add sodium hydroxide solution, and maintain the temperature at 50°C for 10 hours to generate intermediate product II (see [link to product description]). Figure 2 The volume ratio of sodium hydroxide solution to dimethyl sulfoxide solution is 1:2.

[0044] A4: Intermediate product II was mixed with CHPS-Na at a molar ratio of 1:4 and dissolved in a mixture of ethanol and water. The mixture was then refluxed at 85°C for 24 hours to produce the final product shown in Formula 1 (see [link]). Figure 2 ).

[0045] Performance tests on the obtained compounds and intermediates:

[0046] 1. Test methods for simulating corrosion of carbon steel and other metal products under simulated oilfield produced water immersion conditions.

[0047] First, a Q235 carbon steel sheet was selected as the metal to be tested (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%) and used as the working electrode for the electrochemical experiment. The size of the electrode was 10mm x 10mm x 10mm. The sample was polished step by step with 800-3000 grit sandpaper, then rinsed with deionized water, ultrasonically cleaned with anhydrous ethanol for 5 minutes, dried with nitrogen gas, and finally stored in a desiccator for use.

[0048] Electrochemical testing: A three-electrode system was used, with a saturated calomel electrode (SCE) as the reference electrode and a platinum sheet electrode (Pt) with an area of ​​4 cm² as the counter electrode. 2 The working electrode was immersed in both of the above media until the open circuit potential (OCP) stabilized. The electrochemical impedance spectroscopy (EIS) test used a sine wave as the excitation signal with an amplitude of 10 my and a scanning frequency range of 100 kHz to 10 mHz. The test time was the first 8 hours of immersion and the 4th hour of each wet-dry cycle immersion time.

[0049] Specifically:

[0050] Group 1

[0051] Experimental Group 1: Conditions: The experimental material was carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), and the corrosive environment was simulated oilfield produced water with a pH of approximately 3 (composition shown in Table 1). The additive was the compound of Formula 1 prepared in Example 1 above, and the amount of compound added was 1×10⁻⁶. -4 mol / L; the NaCl content in the medium is 36 g / L, the volume is 500 mL; the temperature is 25℃.

[0052] Table 1

[0053]

[0054] Experimental Group 2: Conditions: The experimental material was carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), the corrosive environment was simulated oilfield produced water with a pH of approximately 3, and the additive was the compound of Formula 1 prepared in Example 1 above, with an addition amount of 3 × 10⁻⁶. -4 mol / L; the NaCl content in the medium is 36 g / L, the volume is 500 mL; the temperature is 25℃.

[0055] Experimental Group 3: Conditions: The experimental material was carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), the corrosive environment was simulated oilfield produced water with a pH of approximately 3, and the additive was the compound of Formula 1 prepared in Example 1 above, with an addition amount of 6 × 10⁻⁶. -4mol / L; the NaCl content in the medium is 36 g / L, the volume is 500 mL; the temperature is 25℃.

[0056] Control group: Conditions: The experimental material was carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), the corrosive environment was simulated oilfield produced water with a pH of about 3, the NaCl content in the medium was 36 g / L, and the dosage was 500 mL; no compounds were added, and the temperature was 25℃.

[0057] Group 2

[0058] Experimental Group 1: Conditions: The experimental material was carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), the corrosive environment was simulated oilfield produced water with a pH of approximately 3, and the additive was the compound of Formula 1 prepared in Example 1 above, with an addition amount of 1×10⁻⁶. -4 mol / L; the NaCl content in the medium is 36 g / L, the volume is 500 mL; the temperature is 45 ℃.

[0059] Experimental Group 2: Conditions: The experimental material was carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), the corrosive environment was simulated oilfield produced water with a pH of approximately 3, and the additive was the compound of Formula 1 prepared in Example 1 above, with an addition amount of 3 × 10⁻⁶. -4 mol / L; the NaCl content in the medium is 36 g / L, the volume is 500 mL; the temperature is 45 ℃.

[0060] Experimental Group 3: Conditions: The experimental material was carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), the corrosive environment was simulated oilfield produced water with a pH of approximately 3, and the additive was the compound of Formula 1 prepared in Example 1 above, with an addition amount of 6 × 10⁻⁶. -4 mol / L; the NaCl content in the medium is 36 g / L, the volume is 500 mL; the temperature is 45 ℃.

[0061] Control group: Conditions: The experimental material was carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), the corrosive environment was simulated oilfield produced water with a pH of about 3, the NaCl content in the medium was 36 g / L, and the dosage was 500 mL; no compounds were added, and the temperature was 45℃.

[0062] Group 3

[0063] Experimental Group 1: Conditions: The experimental material was carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), the corrosive environment was simulated oilfield produced water with a pH of approximately 3, and the additive was the compound of Formula 1 prepared in Example 1 above, with an addition amount of 1×10⁻⁶. -4 mol / L; the NaCl content in the medium is 36 g / L, the volume is 500 mL; the temperature is 85 ℃.

[0064] Experimental Group 2: Conditions: The experimental material was carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), the corrosive environment was simulated oilfield produced water with a pH of approximately 3, and the additive was the compound of Formula 1 prepared in Example 1 above, with an addition amount of 3 × 10⁻⁶. -4 mol / L; the NaCl content in the medium is 36 g / L, the volume is 500 mL; the temperature is 85 ℃.

[0065] Experimental Group 3: Conditions: The experimental material was carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), the corrosive environment was simulated oilfield produced water with a pH of approximately 3, and the additive was the compound of Formula 1 prepared in Example 1 above, with an addition amount of 6 × 10⁻⁶. -4 mol / L; the NaCl content in the medium is 36 g / L, the volume is 500 mL; the temperature is 85 ℃.

[0066] Control group: Conditions: The experimental material was carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), the corrosive environment was simulated oilfield produced water with a pH of about 3, the NaCl content in the medium was 36 g / L, and the dosage was 500 mL; no compounds were added, and the temperature was 85℃.

[0067] Group 4

[0068] Experimental group: Conditions: The experimental material was carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), the corrosive environment was a neutral solution with high scale content, and the medium contained Ca... 2+ The content is 1.44 g / L, and the dosage is 500 mL; the additive is the compound of formula one prepared in Example 1 above, and the amount of compound added is 6 × 10⁻⁶. -4 mol / L; temperature 25℃.

[0069] Control group: Conditions: Experimental material was carbon steel (Fe: 99.5%, Mn: 0.4-0.5%, C: 0.1-0.2%), the corrosive environment was a neutral solution with high scale content, and the medium contained Ca... 2+The concentration was 1.44 g / L, and the dosage was 500 mL; the compound was benzimidazole, and the amount added was 6 × 10⁻⁶ g / L. -4 mol / L; temperature 25℃.

[0070] The test results are shown in Table 2 below:

[0071] Table 2

[0072]

[0073] Referring to the data in the table above, Groups 1-3 show that adding corrosion inhibitors can effectively suppress corrosion within a certain temperature range. As the temperature increases, the corrosion inhibitor molecules maintain their adsorption behavior, forming bonds with the carbon steel surface, thereby rapidly adsorbing and covering the active sites. Long-chain alkyl groups enhance the hydrophobicity and stability of the substance. Lower dosages produce higher levels of corrosion inhibition, indicating that the corrosion inhibitor has excellent anti-corrosion capabilities. The table clearly shows that regardless of concentration or temperature, the added corrosion inhibitor exhibits strong corrosion inhibition properties in simulated oil and gas field solutions. It can provide effective and stable anti-corrosion protection over a wide concentration range. Group 4 compares the performance of benzimidazole and the novel corrosion inhibitor synthesized after modification of benzimidazole in this invention in solutions with high scale content, clearly demonstrating the superior performance improvement after modification.

[0074] 2. Conduct static scale inhibition tests on the multifunctional corrosion inhibitor.

[0075] Static scale inhibition tests were conducted using the applicable standards specified in the People's Republic of China National Standard GB / T 16632-2019 to evaluate the scale inhibition performance of the multifunctional corrosion inhibitor. To assess the scale inhibition effect of the compound shown in Formula 1 of this invention, the static scale inhibition efficiency of the compound in Formula 1 and benzimidazole was compared. The test results are as follows. Figure 3 As shown:

[0076] As can be seen from the data in the figure, under the same mass conditions, the static scale inhibition efficiency of benzimidazole is above 8%, while the static scale inhibition efficiency of the compound shown in Formula 1 of this invention is above 80%, which is significantly higher than that of benzimidazole, and the scale inhibition efficiency is nearly an order of magnitude higher than that of benzimidazole.

[0077] 3. Conduct fluorescence microscopy observation tests to assess the bactericidal performance of the multifunctional corrosion inhibitor.

[0078] To verify the bactericidal performance of the multifunctional additive, a fluorescence microscopy observation experiment was conducted. Q235 steel was immersed in simulated oilfield production water containing SRB bacteria (composition as shown in Table 1 of Example Group 1, pH approximately 5) with or without the compound shown in Formula 1, and cultured for 7 days. The test results are as follows. Figure 4 As shown:

[0079] The SRB bacteria used in the simulated oilfield produced water containing SRB bacteria need to be cultured for 2 days before addition, reaching a quantity on the order of 10. 6 SRB bacterial solution was added at a volume ratio of 1:100 to simulated oilfield produced water.

[0080] In the fluorescence images, green and red represent live and dead bacteria, respectively. In the control group without the multifunctional corrosion inhibitor (Fig. (ac)), some live cells and very few dead cells are shown. After adding the multifunctional corrosion inhibitor (Fig. (eg)), the number of live bacteria decreased significantly, while the number of dead bacteria increased. This indicates that the multifunctional corrosion inhibitor effectively inhibits the growth of SRB biofilm. The observed decrease in live bacteria and increase in dead bacteria suggest that the multifunctional corrosion inhibitor not only inhibits SRB proliferation but also induces cell death, which is a key factor in inhibiting biofilm formation and subsequent corrosion processes.

[0081] All the above test results show that the environmentally friendly corrosion inhibitor with integrated functional molecular structure prepared by this invention has excellent performance, high efficiency and durability, low dosage and high efficiency, and has significant application value and broad market prospects.

Claims

1. An environmentally friendly compound with a functionally integrated molecular structure, characterized in that, The compound is shown in Formula 1. Formula 1 In the formula, 。 2. A method for preparing the compound according to claim 1, characterized in that: A1: Preparation of benzimidazole matrix: Lauric acid and o-phenylenediamine were reacted in the presence of an organic solvent under nitrogen protection and with a gradient temperature increase to obtain the benzimidazole matrix; A2: Synthesis of intermediate I: The benzimidazole matrix obtained in step A1 was dissolved in an organic solvent with sodium hydroxide. After stirring at 55-65℃, epichlorohydrin was added to continue the reaction. After purification, intermediate I containing hydroxyl groups was obtained. A3: Synthesis of intermediate II: Intermediate I and acryloyl chloride were mixed and dissolved in an organic solvent, and the system was adjusted to react at 45-55℃ under alkaline conditions to obtain intermediate II containing double bonds; A4: Preparation of final product: Intermediate II was mixed with CHPS-Na and quaternized at 75-85℃, and the final product was obtained after purification. Its synthetic route is as follows: 。 3. The method for preparing the compound according to claim 2, characterized in that: In step A1, lauric acid and o-phenylenediamine are mixed in a molar ratio of 1:1.1 to 1.3 and dissolved in xylene.

4. The method for preparing the compound according to claim 2, characterized in that: In step A1, the gradient temperature reaction is carried out at 155-165℃ for 3.5-4.5 hours in the first stage and at 215-225℃ for 2.5-3.5 hours in the second stage. After the reaction is completed, the solvent is removed by vacuum distillation to obtain the benzimidazole matrix.

5. The method for preparing the compound according to claim 2, characterized in that: In step A2, the benzimidazole matrix and sodium hydroxide are mixed in a molar ratio of 1:1.0 to 1.

1. In step A3, the amount of intermediate I and acryloyl chloride is in a molar ratio of 1:1.0 to 1.

05.

6. The method for preparing the compound according to claim 2, characterized in that: The organic solvents used in steps A2 and A3 may be the same or different and may be selected from one or more of xylene, dimethyl sulfoxide, dichloromethane, and ethyl acetate.

7. The method for preparing the compound according to claim 2, characterized in that: In step A4, the amount of intermediate II and CHPS-Na is used in a molar ratio of 1:1 to 1.

1.

8. An application of the compound according to claim 1, characterized in that: The compound is used in the preparation of multifunctional corrosion inhibitors for oil and gas fields.

9. An intermediate for preparing the compound of claim 1, characterized in that: The intermediate has the structure shown below. 。

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