A chitosan-based corrosion and scale inhibitor, its preparation method and application

Abstract

This invention discloses a chitosan-based corrosion and scale inhibitor, its preparation method, and its application, belonging to the field of biomass materials and water treatment technology. The chitosan-based corrosion and scale inhibitor has the following general structural formula: [Insert general structural formula here]. This invention also proposes a preparation method for the above-mentioned chitosan-based corrosion and scale inhibitor, comprising the following steps: dissolving chitosan in an HAc solution, then adding maleic anhydride solution dropwise and mixing, and carrying out a ring-opening reaction under heating conditions to obtain CM; adding itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, and (3-acrylamidopropyl)trimethylammonium chloride monomers to the above CM, then adding an initiator, and heating the reaction to obtain the chitosan-based corrosion and scale inhibitor. The chitosan-based corrosion and scale inhibitor proposed in this invention has excellent scale inhibition and corrosion prevention properties.

Description

Technical Field

[0001] This invention relates to the fields of biomass materials and water treatment technology, specifically to a chitosan-based corrosion and scale inhibitor, its preparation method, and its application. Background Technology

[0002] During crude oil extraction, produced groundwater is generated along with the oil. To balance reservoir pressure and promote water recycling, this water is usually reinjected into the formation. However, this water has a complex composition, containing various metal ions and acid radicals. These ions easily interact, causing scale buildup that clogs pipeline walls and leads to under-deposit corrosion, resulting in pipeline perforation, increased maintenance and replacement costs, and severely limiting crude oil extraction efficiency.

[0003] Previously, the main approach to addressing corrosion and scaling during oilfield extraction was to add oilfield chemical additives such as corrosion inhibitors and scale inhibitors to the water. However, water quality and environmental conditions vary significantly across different regions, and these additives often operate in harsh environments with high temperatures and high salinity. Therefore, single-effect scale inhibitors or corrosion inhibitors are insufficient to simultaneously inhibit scaling and corrosion. To achieve both scale inhibition and corrosion prevention, various types of corrosion inhibitors and scale inhibitors need to be compounded in specific proportions. However, the physicochemical properties of corrosion inhibitors and scale inhibitors often differ significantly and they are incompatible, frequently leading to incompatibility issues and even agent ineffectiveness. Adding them separately, on the other hand, presents complex processes and is time-consuming and labor-intensive. Therefore, developing an "integrated scale inhibition and corrosion prevention" inhibitor seems more promising. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a chitosan-based corrosion and scale inhibitor, its preparation method and application, thereby solving the technical problem that inhibitors in the prior art cannot simultaneously achieve both scale inhibition and corrosion prevention performance.

[0005] To achieve the above-mentioned technical objectives, the present invention provides a chitosan-based corrosion and scale inhibitor with the following general structural formula: In the formula, n, x, y, z, m are any integers from 1 to 10.

[0006] In any embodiment, the chitosan-based corrosion and scale inhibitor is a polymer formed by grafting chitosan, maleic anhydride, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid and (3-acrylamidopropyl)trimethylammonium chloride monomers.

[0007] Furthermore, this invention also proposes a method for preparing the above-mentioned chitosan-based corrosion and scale inhibitor, comprising the following steps: S1. Chitosan is dissolved in HAc solution, then maleic anhydride solution is added dropwise and mixed, and a ring-opening reaction is carried out under heating conditions to obtain CM; S2. Add itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid and (3-acrylamidopropyl)trimethylammonium chloride to the above CM, then add an initiator, and heat the reaction to obtain the chitosan-based corrosion and scale inhibitor.

[0008] In any embodiment, in step S1, the mass ratio of chitosan to maleic anhydride is 1:(3-5).

[0009] In any embodiment, in step S1, the heating temperature is 65-75°C, and the heating time is 2-4 hours.

[0010] In any embodiment, in step S2, the mass ratio of the chitosan, the itaconic acid, the 2-acrylamido-2-methylpropanesulfonic acid and the (3-acrylamidopropyl)trimethylammonium chloride is 1:(6-7):(3-4):(3-4).

[0011] In any embodiment, in step S2, the heating temperature is 65-75°C, and the heating time is 2-4 hours.

[0012] In any embodiment, in step S2, the initiator is ammonium persulfate; and / or, the amount of the initiator added is 4-6% of the total mass of the five monomers.

[0013] In any embodiment, in step S1, the maleic anhydride solution is prepared by dissolving maleic anhydride in DMF solution.

[0014] Furthermore, this invention also proposes the application of the above-mentioned chitosan-based corrosion and scale inhibitor or the chitosan-based corrosion and scale inhibitor prepared by the above-mentioned preparation method in oilfield water treatment.

[0015] Compared with the prior art, the beneficial effects of the present invention include: the present invention uses chitosan / maleic anhydride / itaconic acid / 2-acrylamido-2-methylpropanesulfonic acid / (3-acrylamidopropyl)trimethylammonium chloride as monomers to form a copolymer scale inhibitor through graft copolymerization. Chitosan itself has a large number of -OH and -NH2 groups, and after reacting with other monomers, -COOH, -SO3H, -CONH2 and N+ are introduced. -COOH is the main group inhibiting the formation of calcium scale, and -COOH and -SO3H can react with calcium (Ca) in water. 2+ ), magnesium (Mg) 2+ Metal ions such as -CONH2 and N form stable soluble complexes. +It can form a thin film by adsorbing onto the metal surface. This film can prevent air from contacting the metal, thus playing a role in corrosion prevention and exhibiting excellent scale inhibition and corrosion prevention properties.

[0016] This invention, from a green and environmentally friendly perspective, provides a scale inhibitor that is more environmentally friendly than traditional phosphorus-based scale inhibitors, as its biodegradability allows it to degrade more quickly in the environment. It not only possesses the scale inhibition properties of traditional scale inhibitors but also has corrosion inhibition properties that traditional scale inhibitors lack, enabling a single application to simultaneously achieve both scale inhibition and corrosion inhibition. Attached Figure Description

[0017] Figure 1 The infrared spectrum of the corrosion and scale inhibitor prepared in Example 1 of this invention. Detailed Implementation

[0018] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for a specific parameter, it is also expected that ranges of 60~110 and 80~120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this application, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0019] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0020] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0021] This specific embodiment provides a chitosan-based corrosion and scale inhibitor with the following general structural formula: In the formula, n, x, y, z, m are any integers from 1 to 10; The chitosan-based corrosion and scale inhibitor is a polymer formed by grafting chitosan, maleic anhydride, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid and (3-acrylamidopropyl)trimethylammonium chloride monomers.

[0022] This specific embodiment also proposes a method for preparing the above-mentioned chitosan-based corrosion and scale inhibitor, including the following steps: S1. Chitosan is dissolved in HAc solution, then maleic anhydride solution is added dropwise and mixed, and the mixture is heated at 65-75℃ for 2-4 hours to carry out a ring-opening reaction to obtain CM; the mass ratio of chitosan to maleic anhydride is 1:(3-5); the maleic anhydride solution is prepared by dissolving maleic anhydride in DMF solution; S2. Add itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, and (3-acrylamidopropyl)trimethylammonium chloride to the above CM, and then add ammonium persulfate initiator. After heating and reacting at 65-75℃ for 2-4 hours, the chitosan-based corrosion and scale inhibitor is obtained; the mass ratio of chitosan, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, and (3-acrylamidopropyl)trimethylammonium chloride is 1:(6-8):(2-4):(2-4); the amount of initiator added is 4-6% of the total mass of the five monomers.

[0023] This specific embodiment also proposes the application of the above-mentioned chitosan-based corrosion and scale inhibitor or the chitosan-based corrosion and scale inhibitor prepared by the above preparation method in oilfield water treatment.

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] In this invention, the terms "some embodiments," "this embodiment," and examples are used to describe a subset of all possible embodiments. However, it is understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with each other without conflict.

[0026] If the application documents contain similar descriptions such as "first / second", the following explanation shall be added: In the following description, the terms "first / second / third" are used only to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0027] In this embodiment, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist simultaneously, and object B exists alone.

[0028] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0029] The maleic anhydride solution described in the following examples or comparative examples was prepared by dissolving maleic anhydride in DMF solution.

[0030] Example 1

[0031] This embodiment proposes a chitosan-based corrosion and scale inhibitor with the following general structural formula: In the formula, n, x, y, z, m are any integers from 1 to 10; It is prepared by the following steps: Under N2 conditions (with air removed by purging), a certain amount of chitosan and 5% acetic acid solution were added to the reactor. The mixture was stirred in a 50°C water bath until the chitosan was completely dissolved. Then, maleic anhydride solution was added dropwise over 30 minutes using a constant-pressure dropping funnel, with the mixture stirred continuously. The mass ratio of chitosan to maleic anhydride was 1:4. The temperature was then raised to 70°C and the reaction was continued for 3 hours. After the reaction time was reached, the mixture was cooled to room temperature to obtain CM. Itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, and (3-acrylamidopropyl)trimethylammonium chloride were then added, with the mass ratio of chitosan, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, and (3-acrylamidopropyl)trimethylammonium chloride being 1:7:3:3. Ammonium persulfate was added as an initiator, and the reaction was continued at 70°C for 3 hours. After cooling, the reaction product solution was obtained. The product solution was purified by dialysis and then freeze-dried to obtain the purified corrosion and scale inhibitor CM-g-IAA.

[0032] Example 2

[0033] This embodiment proposes a chitosan-based corrosion and scale inhibitor, which is prepared by the following steps: Under N2 conditions (with air removed by purging), a certain amount of chitosan and 5% acetic acid solution were added to the reactor. The mixture was stirred in a 50°C water bath until the chitosan was completely dissolved. Then, maleic anhydride solution was added dropwise over 30 minutes using a constant-pressure dropping funnel, with the mixture stirred continuously. The mass ratio of chitosan to maleic anhydride was 1:5. The temperature was then raised to 75°C and the reaction was continued for 2 hours. After the reaction time was reached, the mixture was cooled to room temperature to obtain CM. Then, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, and (3-acrylamidopropyl)trimethylammonium chloride were added, with the mass ratio of chitosan, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, and (3-acrylamidopropyl)trimethylammonium chloride being 1:6:3:4. Ammonium persulfate was added as an initiator, and the reaction was continued at 75°C for 2 hours. After cooling, the reaction product solution was obtained. The product solution was purified by dialysis and then freeze-dried to obtain the purified corrosion and scale inhibitor CM-g-IAA.

[0034] Example 3

[0035] This embodiment proposes a chitosan-based corrosion and scale inhibitor, which is prepared by the following steps: Under N2 conditions (with air removed by purging), a certain amount of chitosan and 5% acetic acid solution were added to the reactor. The mixture was stirred in a 50°C water bath until the chitosan was completely dissolved. Then, maleic anhydride solution was added dropwise over 30 minutes using a constant-pressure dropping funnel, with the mixture stirred continuously. The mass ratio of chitosan to maleic anhydride was 1:3. The temperature was then raised to 65°C and the reaction was continued for 4 hours. After the reaction time was reached, the mixture was cooled to room temperature to obtain CM. Then, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, and (3-acrylamidopropyl)trimethylammonium chloride were added, with the mass ratio of chitosan, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, and (3-acrylamidopropyl)trimethylammonium chloride being 1:7:4:3. Ammonium persulfate was added as an initiator, and the reaction was continued at 65°C for 2 hours. After cooling, the reaction product solution was obtained. The product solution was purified by dialysis and then freeze-dried to obtain the purified corrosion and scale inhibitor CM-g-IAA.

[0036] Comparative Example 1 This comparative example presents a chitosan-based corrosion and scale inhibitor, which is prepared by the following steps: Under N2 conditions (with air removed by purging), a certain amount of chitosan and 5% acetic acid solution were added to the reactor. The mixture was stirred in a 50°C water bath until the chitosan was completely dissolved. Then, maleic anhydride solution was added dropwise over 30 minutes using a constant-pressure dropping funnel, with the mixture stirred continuously. The mass ratio of chitosan to maleic anhydride was 1:4. The temperature was then raised to 70°C and the reaction was continued for 3 hours. After the reaction time was reached, the mixture was cooled to room temperature to obtain CM. Then, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, and (3-acrylamidopropyl)trimethylammonium chloride were added, with the mass ratio of chitosan, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, and (3-acrylamidopropyl)trimethylammonium chloride being 1:5:2:2. Ammonium persulfate was added as an initiator, and the reaction was continued at 70°C for 3 hours. After cooling, the reaction product solution was obtained. The product solution was purified by dialysis and then freeze-dried to obtain the purified corrosion and scale inhibitor CM-g-IAA.

[0037] Comparative Example 2 This comparative example presents a chitosan-based corrosion and scale inhibitor, which is prepared by the following steps: Under N2 conditions (with air removed by purging), a certain amount of chitosan and 5% acetic acid solution were added to the reactor. The mixture was stirred in a 50°C water bath until the chitosan was completely dissolved. Then, maleic anhydride solution was added dropwise over 30 minutes using a constant-pressure dropping funnel, with the mixture stirred continuously. The mass ratio of chitosan to maleic anhydride was 1:4. The temperature was then raised to 70°C and the reaction was continued for 3 hours. After the reaction time was reached, the mixture was cooled to room temperature to obtain CM. Itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, and (3-acrylamidopropyl)trimethylammonium chloride were then added, with the mass ratio of chitosan, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, and (3-acrylamidopropyl)trimethylammonium chloride being 1:8:5:5. Ammonium persulfate was added as an initiator, and the reaction was continued at 70°C for 3 hours. After cooling, the reaction product solution was obtained. The product solution was purified by dialysis and then freeze-dried to obtain the purified corrosion and scale inhibitor CM-g-IAA.

[0038] Comparative Example 3 The difference between this comparative example and the chitosan-based corrosion and scale inhibitor preparation method in Example 1 is that 2-acrylamido-2-methylpropanesulfonic acid is omitted, and itaconic acid is replaced with an equal amount; otherwise, it is the same as in Example 3.

[0039] Comparative Example 4 The difference between the preparation method of the chitosan-based corrosion and scale inhibitor in this comparative example and that in Example 1 is that (3-acrylamidopropyl)trimethylammonium chloride is omitted, and an equal amount of itaconic acid is used to replace (3-acrylamidopropyl)trimethylammonium chloride. Otherwise, the preparation method is the same as in Example 3.

[0040] Corrosion Inhibition Performance Test The test medium was simulated oilfield water, the test method was a rotating strip corrosion test, and the test material was carbon steel. The specific method is as follows: First, prepare simulated oilfield water. Weigh out 50g NaCl, 2g MgCl·6H2O, 6g Na2SO4, 4g CaCl2, and 0.4g NaHCO3, dissolve them in a small amount of distilled water, transfer them to a 1L volumetric flask, and make up to volume for later use.

[0041] Next, process the carbon steel test pieces. Measure the size of the test pieces with vernier calipers, accurate to 0.02 mm, and calculate the area. Wipe the test pieces clean with filter paper, place them in a container filled with petroleum ether with a boiling range of 60-90℃, remove surface grease with degreasing cotton, and then soak them in anhydrous ethanol for 5 minutes for further degreasing and dehydration. Remove the test pieces, place them on filter paper, dry them with cold air, wrap them in filter paper again, and store them in a desiccator. After 1 hour, weigh them to an accuracy of 0.01 mg.

[0042] The corrosion inhibitor was added to the experimental container, and the concentration of the corrosion inhibitor in the water sample was 100 mg / L. The amount of water sample used was per 1 cm³. 2 The surface area of ​​the test piece should be no less than 20 mL, and the test piece area should be 50 mm * 13 mm * 1.5 mm. The experimental container was purged with nitrogen to remove air, and then simulated oilfield water was introduced through a rubber tube. A blank experiment without corrosion inhibitor was also performed. The container was placed in a constant temperature chamber at 50℃ for 3 days. The test results are recorded in Table 1.

[0043] Table 1. Test results of corrosion inhibition performance of corrosion and scale inhibitors Note: Medium blank mass loss Δm0 = 0.0225g; annual uniform corrosion rate is 0.2530mm / year.

[0044] As can be seen from Table 1, the corrosion and scale inhibitor provided by this invention has good corrosion inhibition performance, especially at a dosage of 100 mg·L⁻¹. -1 It can achieve a uniform corrosion inhibition efficiency of 84.4% and a corrosion rate of 0.0426 mm / year.

[0045] Performance test of calcium carbonate scale inhibition The static scale inhibition evaluation method was used to test the calcium carbonate scale inhibition performance of the graft copolymer prepared in the examples, and the results are recorded in Table 2.

[0046] Accurately weigh 0.50 g of scale inhibitor, dissolve it in a small amount of pure water, and transfer it to a 250 mL volumetric flask. Dilute to the mark to obtain the scale inhibitor solution. Take 200 mL of pure water into a 250 mL volumetric flask, add 6.00 mL of pre-prepared CaCl2 solution, and dilute to the mark to obtain the scale inhibitor solution. 2+ The content is 96.00 mg·L. -1 Accurately add 3.75 mL of scale inhibitor solution, let stand for 10 minutes, then add the pre-prepared Na2CO3 solution while shaking, so that the CO32-... 2- The content is 150.72 mg·L. -1 Dilute with pure water to the mark and pour into a ground glass stoppered Erlenmeyer flask. Place in a water bath at 50℃ ± 1℃ for 30 minutes and let stand for 16 hours. Perform blank experiment one and blank experiment two simultaneously.

[0047] After the reaction was complete, the solution was cooled to room temperature and filtered using quantitative filter paper. The filtrate of CaCO3 was titrated with a standard solution of ethylenediaminetetraacetic acid (EDTA) to determine the Ca2+ content. 2+ The concentration of scale. The scale inhibition rate is calculated using the following formula: Where η (%) is the scale inhibition rate, This represents the volume of EDTA consumed by all calcium ions in the solution. This represents the volume of EDTA consumed by calcium ions in the solution when no scale inhibitor was added. This represents the volume of EDTA consumed by calcium ions present after the addition of scale inhibitor to the solution.

[0048] Table 2. Test results of scale inhibition performance of corrosion and scale inhibitors As shown in Table 2, the chitosan graft copolymer green corrosion and scale inhibitor provided by this invention has an inhibitory effect on calcium carbonate, and under the optimal monomer synthesis ratio, when the scale inhibitor dosage is 30 mg·L... -1 At that time, the scale inhibition efficiency can reach 95.80%.

[0049] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A chitosan-based corrosion and scale inhibitor, characterized in that, It has the following general structural formula: In the formula, n, x, y, z, m are any integers from 1 to 10.

2. The method for preparing the chitosan-based corrosion and scale inhibitor according to claim 1, characterized in that, The chitosan-based corrosion and scale inhibitor is a polymer formed by grafting chitosan, maleic anhydride, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid and (3-acrylamidopropyl)trimethylammonium chloride monomers.

3. A method for preparing the chitosan-based corrosion and scale inhibitor according to any one of claims 1-2, characterized in that, Includes the following steps: S1. Chitosan is dissolved in HAc solution, then maleic anhydride solution is added dropwise and mixed, and a ring-opening reaction is carried out under heating conditions to obtain CM; S2. Add itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid and (3-acrylamidopropyl)trimethylammonium chloride to the above CM, then add an initiator, and heat the reaction to obtain the chitosan-based corrosion and scale inhibitor.

4. The method for preparing the chitosan-based corrosion and scale inhibitor according to claim 3, characterized in that, In step S1, the mass ratio of chitosan to maleic anhydride is 1:(3-5).

5. The method for preparing the chitosan-based corrosion and scale inhibitor according to claim 3, characterized in that, In step S1, the heating temperature is 65-75℃, and the heating time is 2-4 hours.

6. The method for preparing the chitosan-based corrosion and scale inhibitor according to claim 3, characterized in that, In step S2, the mass ratio of chitosan, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid and (3-acrylamidopropyl)trimethylammonium chloride is 1:(6-7):(3-4):(3-4).

7. The method for preparing the chitosan-based corrosion and scale inhibitor according to claim 3, characterized in that, In step S2, the heating temperature is 65-75℃, and the heating time is 2-4 hours.

8. The method for preparing the chitosan-based corrosion and scale inhibitor according to claim 3, characterized in that, In step S2, the initiator is ammonium persulfate; and / or, the amount of the initiator added is 4-6% of the total mass of the five monomers.

9. The method for preparing the chitosan-based corrosion and scale inhibitor according to claim 3, characterized in that, In step S1, the maleic anhydride solution is prepared by dissolving maleic anhydride in DMF solution.

10. The application of a chitosan-based corrosion and scale inhibitor according to any one of claims 1-3 or a chitosan-based corrosion and scale inhibitor prepared by any one of claims 4-9 in oilfield water treatment.

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