A scale inhibitor and its preparation method and application

Abstract

The present invention relates to the technical field of energy conservation and environmental protection, and specifically discloses a scale inhibitor and a preparation method and application thereof. The scale inhibitor provided by the present invention is obtained by addition reaction of 3,5-diamino-1,2,4-triazole and methylene succinic acid, and is a scale inhibitor suitable for industrial circulating cooling systems of high-salt water systems, with the advantages of low cost, simple operation, safety and high efficiency, etc., and can form a dense and firm protective film on the metal surface under the conditions of a high-salt water system, effectively slowing down the corrosion and scaling rate of the metal, and the scale inhibition rate and corrosion inhibition rate in the high-salt water system can reach more than 90%, which is beneficial to improve the equipment life, and significantly reduce the scaling phenomenon on the surface of the heat exchange equipment, improve the heat exchange rate, reduce energy consumption, and ensure the safe, efficient and stable operation of the industrial circulating cooling water system, which is of great significance for promoting the sustainable development of the industrial field.

Description

Technical Field

[0001] The present invention relates to the technical field of energy conservation and environmental protection, and in particular to a scale inhibitor and a preparation method and application thereof. Background Art

[0002] The demand for water in industries such as petrochemical, metallurgy, steel, pharmaceutical, electric power and printing and dyeing is very large, and water consumption is mainly concentrated in circulating cooling water. Although most companies have adopted circulating cooling water systems to achieve water reuse, the water utilization rate is not high, resulting in serious waste of water resources. Therefore, at present, reasonable technical means are mainly used to increase the concentration multiple of circulating cooling water to reduce the amount of fresh water replenishment and reduce the amount of sewage discharged, thereby achieving water resource conservation and environmental protection benefits.

[0003] However, as the concentration ratio of the system increases, the water quality of the circulating water system is characterized by high hardness, high alkalinity and high content of corrosive ions. In order to make the system operate safely under this condition, solving the scale and corrosion problems in this high-salt water quality has become the focus of water conservation. In addition, due to the shortage of fresh water resources, the water use of industrial circulating cooling water systems has begun to shift from direct use of groundwater or tap water to the use of treated reclaimed water, sewage or seawater and other high-salt water systems. The high-salt water system generally has a high content of scaling ions and corrosive ions such as calcium ions, magnesium ions, and chloride ions. The heat exchange equipment in the industrial circulating cooling water system will suffer from severe corrosion and scaling, resulting in a decrease in the heat transfer capacity of the equipment and a waste of energy and resources.

[0004] As an important water treatment chemical that can promote the stability of cooling water systems and maximize the reuse of cooling water, scale inhibitors and corrosion inhibitors have developed rapidly in recent years. However, the current scale inhibitors and corrosion inhibitors have poor scale and corrosion inhibition performance in the high-salt water system of industrial circulating cooling water systems. The scale inhibition rate and corrosion inhibition rate can generally only reach about 50%~60%, and it is difficult to further improve. Therefore, it is of great significance to promote the development of water treatment agents in my country to develop an environmentally friendly scale inhibitor and corrosion inhibitor suitable for the high-salt water system of industrial circulating cooling water systems to effectively alleviate the corrosion problem of the high-salt water system of industrial circulating cooling water systems and ensure the safe and stable operation of circulating cooling water systems. Summary of the invention

[0005] In view of the problems that the scale inhibitors and corrosion inhibitors in the prior art have poor scale inhibition and corrosion inhibition performance on industrial circulating cooling water systems with high salt water systems, the present invention provides a scale inhibitor and corrosion inhibitor, and a preparation method and application thereof.

[0006] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0007] In a first aspect, the present invention provides a scale inhibitor and a corrosion inhibitor, wherein the structure of the scale inhibitor and a corrosion inhibitor is shown in Formula I:

[0008]

[0009] Formula Ⅰ.

[0010] Compared with the prior art, the scale inhibitor provided by the present invention contains a conjugated system of triazole, and methylene succinic acid groups are introduced into the two -NH2 of triazole, so that the scale inhibitor provided by the present invention contains more carboxyl groups in the molecular structure, which can more effectively attract and chelate Ca 2+ , reduce Ca in high salt water system 2+ concentration, thereby significantly reducing the growth rate of calcium carbonate microcrystals. At the same time, the scale inhibitor and corrosion inhibitor of the present invention can be adsorbed on the microcrystals of inorganic salts, so that the repulsion between the particles is increased, thereby hindering their aggregation; in addition, the structure of the scale inhibitor and corrosion inhibitor provided by the present invention is also conducive to its adsorption on the metal surface, and chemically reacts with the metal surface to form a protective film with a barrier effect, thereby effectively hindering the collision between the calcium carbonate microcrystals and the heat transfer surface of the metal container to form a scaling layer, and isolating the metal from the contact with the corrosive medium, thereby slowing down the corrosion rate. The scale inhibitor and corrosion inhibitor provided by the present invention can significantly reduce metal corrosion and reduce the formation of scale. It shows good scale inhibition and corrosion inhibition performance in the actual application of high-salt water system. It is of great significance for extending the service life of equipment and protecting the environment. It can meet the needs of modern industry for high-performance scale inhibitors and corrosion inhibitors and has high practical value.

[0011] In a second aspect, the present invention also provides a method for preparing a scale inhibitor and a corrosion inhibitor, wherein 3,5-diamino-1,2,4-triazole and methylene succinic acid are used as raw materials to prepare the scale inhibitor and a corrosion inhibitor through an addition reaction.

[0012] As a specific embodiment of the present invention, the preparation method of the scale and corrosion inhibitor comprises the following steps:

[0013] Step a, dissolving 3,5-diamino-1,2,4-triazole and methylenesuccinic acid in water respectively to obtain an aqueous solution of 3,5-diamino-1,2,4-triazole and an aqueous solution of methylenesuccinic acid;

[0014] Step b, under an inert atmosphere, adding an initiator to the 3,5-diamino-1,2,4-triazole aqueous solution, mixing evenly, adding a methylene succinic acid aqueous solution, heating to carry out an addition reaction, and obtaining a scale inhibitor and corrosion inhibitor as shown in formula I, i.e. methylene succinic acid-3,5-diamino-1,2,4-triazole (IA-DMTA), and the reaction equation is as follows.

[0015]

[0016] The preparation method of the scale and corrosion inhibitor provided by the present invention is simple, the reaction conditions are mild, the operation is simple and convenient, and the product yield is high, which is convenient for large-scale production and application.

[0017] Furthermore, the molar ratio of the 3,5-diamino-1,2,4-triazole to methylene succinic acid is 1:2.0 to 1:2.5.

[0018] Furthermore, the mass concentration of the 3,5-diamino-1,2,4-triazole aqueous solution is 4% to 5%.

[0019] Furthermore, the mass concentration of the methylene succinic acid aqueous solution is 7% to 10%.

[0020] Furthermore, the initiator is an aqueous persulfate solution with a mass concentration of 9% to 12%, wherein the mass ratio of ammonium persulfate to 3,5-diamino-1,2,4-triazole in the initiator is 0.2:1 to 0.4:1.

[0021] Furthermore, the temperature of the addition reaction is 76° C. to 82° C., and the reaction time is 4 h to 6 h.

[0022] The preferred addition ratio of each substance, as well as the preferred reaction temperature and time, can improve the conversion rate of 3,5-diamino-1,2,4-triazole, reduce the occurrence of side reactions, and thus improve the yield and purity of the methylene succinic acid-3,5-diamino-1,2,4-triazole product.

[0023] Furthermore, the methylene succinic acid aqueous solution is added in a slow dripping manner, and the dripping time is 0.5h~1h.

[0024] It should be noted that the above reaction time includes the time for dropping the methylenesuccinic acid aqueous solution.

[0025] The preferred method and time of adding the methylene succinic acid aqueous solution can allow 3,5-diamino-1,2,4-triazole to fully react with methylene succinic acid, reduce the occurrence of side reactions, and improve the yield and purity of the methylene succinic acid-3,5-diamino-1,2,4-triazole product.

[0026] Furthermore, after the addition reaction is completed, a post-treatment process is also included: cooling the reaction solution to room temperature, adjusting the pH to 8-9 with a sodium hydroxide solution, adding anhydrous ethanol for washing, standing for stratification, filtering, drying the obtained solid, and grinding to obtain a scale inhibitor and corrosion inhibitor.

[0027] Specifically, a sodium hydroxide solution with a mass concentration of 18% to 22% is used to adjust the pH to 8 to 9.

[0028] It should be noted that the inert atmosphere in the present invention is provided by conventional inert gases in the art, such as nitrogen, argon, etc.

[0029] In a third aspect, as another object of the present invention, the present invention also provides a scale inhibitor and corrosion inhibitor composition, comprising the above-mentioned scale inhibitor and corrosion inhibitor composition.

[0030] The scale and corrosion inhibitor can be used in combination with conventional water treatment agents in the art as long as there is no adverse effect between the components.

[0031] In a fourth aspect, the present invention also provides the use of the above-mentioned scale inhibitor and corrosion inhibitor in an industrial circulating cooling water system of a high-salt water system.

[0032] The present invention provides an efficient, multifunctional, environmentally friendly scale and corrosion inhibitor, which can be used in industrial circulating cooling water systems with high salt water systems, effectively inhibiting the corrosion of various metal containers, and preventing the formation of various scales (such as calcium carbonate, calcium sulfate, calcium phosphate, calcium silicate, etc.). In addition, it has good compatibility with other water treatment agents, can meet the requirements of continuous and stable operation of industrial production, can significantly extend the service life of equipment, and ensure the safe, efficient and energy-saving operation of industrial water systems, thereby promoting the sustainable development of the industrial field, and has high economic and environmental value.

[0033] Furthermore, the addition amount of the scale inhibitor and corrosion inhibitor is 50 mg / L to 80 mg / L.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention creatively proposes a novel scale inhibitor and corrosion inhibitor for an industrial circulating cooling water system of a high-salt water system, which is obtained by addition reaction of 3,5-diamino-1,2,4-triazole and methylene succinic acid. The present invention is a scale inhibitor and corrosion inhibitor suitable for an industrial circulating cooling water system of a high-salt water system, has the advantages of low cost, simple operation, safety and high efficiency, etc., can form a dense and firm protective film on the metal surface under the conditions of a high-salt water system, effectively slow down the corrosion and scaling rate of the metal, and the scale inhibition rate and corrosion inhibition rate in the high-salt water system can reach more than 90%, which is beneficial to prolonging the life of the equipment and protecting the safe operation of the system, and is of great significance to promoting the development of water treatment agents in my country. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is the infrared spectrum of the methylenesuccinic acid-3,5-diamino-1,2,4-triazole product prepared in Example 1. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0038] In order to better illustrate the present invention, further examples are given below.

[0039] Example 1

[0040] A method for preparing a scale and corrosion inhibitor comprises the following steps:

[0041] Weigh 13 g of methylene succinic acid and dissolve it in 150 mL of distilled water to obtain a methylene succinic acid aqueous solution. Weigh 4.95 g of 3,5-diamino-1,2,4-triazole and dissolve it in 100 mL of distilled water to obtain a 3,5-diamino-1,2,4-triazole aqueous solution.

[0042] Under nitrogen protection, 15 g of 9% ammonium persulfate aqueous solution was added dropwise to the 3,5-diamino-1,2,4-triazole aqueous solution at 75°C for 0.5 h, and then methylene succinic acid aqueous solution was added dropwise at 76°C for 0.5 h. After the addition was completed, the reaction was kept warm for 3.5 h, cooled to room temperature, and the pH of the system was adjusted to 8.8 with a 20% NaOH aqueous solution. The system was washed with anhydrous ethanol for 5 times, stirred, allowed to stand for stratification, and the brown precipitate was filtered out. It was vacuum dried at 80°C to constant weight and ground to obtain methylene succinic acid-3,5-diamino-1,2,4-triazole (IA-DMTA).

[0043] The methylene succinic acid-3,5-diamino-1,2,4-triazole product prepared in this example was subjected to infrared measurement, and the obtained infrared spectrum is shown in FIG1 .

[0044] It can be seen from the figure that methylene succinic acid-3,5-diamino-1,2,4-triazole is at 3317 cm -1 A broad absorption peak appears at 3400~3500cm, which is the stretching vibration absorption peak of -NH in the copolymer, while -NH2 is at 3400~3500cm -1 There are two stretching vibration absorption peaks between them, indicating that a methylene succinic acid group is introduced into the -NH2 in the molecular structure of 3,5-diamino-1,2,4-triazole. -1 The stretching vibration absorption peak of the CH bond is at 1714cm -1 The stretching vibration absorption peak of C=O bond is at 1408cm -1 The bending vibration absorption peak of the CH bond is at 1285cm -1 The peak at 1178cm is the stretching vibration absorption peak of CO bond; -1The stretching vibration absorption peak of CC bond is at 1614cm -1 The bending vibration absorption peak of NH bond is at 1546cm -1 The bending vibration absorption peak of NH bond is at 1056cm -1 The peak at the center is the stretching vibration absorption peak of the CN bond, proving that methylenesuccinic acid-3,5-diamino-1,2,4-triazole was successfully synthesized.

[0045] Example 2

[0046] A method for preparing a scale and corrosion inhibitor comprises the following steps:

[0047] Weigh 14.3 g of methylene succinic acid and dissolve it in 150 mL of distilled water to obtain a methylene succinic acid aqueous solution. Weigh 4.95 g of 3,5-diamino-1,2,4-triazole and dissolve it in 115 mL of distilled water to obtain a 3,5-diamino-1,2,4-triazole aqueous solution.

[0048] Under nitrogen protection, 15 g of 10% ammonium persulfate aqueous solution was added dropwise to the 3,5-diamino-1,2,4-triazole aqueous solution at 75°C for 0.5 h, and then methylene succinic acid aqueous solution was added dropwise at 78°C for 0.5 h. After the addition was completed, the reaction was kept warm for 4.5 h, cooled to room temperature, and the pH of the system was adjusted to 8.6 with a 20% NaOH aqueous solution. The system was washed with anhydrous ethanol for 5 times, stirred, and allowed to stand for stratification. The brown precipitate was filtered out, dried in vacuo at 80°C to constant weight, and ground to obtain methylene succinic acid-3,5-diamino-1,2,4-triazole (IA-DMTA).

[0049] Example 3

[0050] A method for preparing a scale and corrosion inhibitor comprises the following steps:

[0051] Weigh 14.3 g of methylene succinic acid and dissolve it in 150 mL of distilled water to obtain a methylene succinic acid aqueous solution. Weigh 4.95 g of 3,5-diamino-1,2,4-triazole and dissolve it in 110 mL of distilled water to obtain a 3,5-diamino-1,2,4-triazole aqueous solution.

[0052] Under nitrogen protection, 15 g of 12% ammonium persulfate aqueous solution was added dropwise to the 3,5-diamino-1,2,4-triazole aqueous solution at 75°C for 0.5 h, and then methylene succinic acid aqueous solution was added dropwise at 80°C for 0.5 h. After the addition was completed, the mixture was kept warm for 5.5 h and cooled to room temperature. The pH of the system was adjusted to 8.5 with a 20% NaOH aqueous solution, washed with anhydrous ethanol for 5 times, stirred, allowed to stand for stratification, and the brown precipitate was filtered out. It was vacuum dried at 80°C to constant weight and ground to obtain methylene succinic acid-3,5-diamino-1,2,4-triazole (IA-DMTA).

[0053] Example 4

[0054] A method for preparing a scale and corrosion inhibitor comprises the following steps:

[0055] Weigh 15.6 g of methylene succinic acid and dissolve it in 150 mL of distilled water to obtain a methylene succinic acid aqueous solution. Weigh 4.95 g of 3,5-diamino-1,2,4-triazole and dissolve it in 105 mL of distilled water to obtain a 3,5-diamino-1,2,4-triazole aqueous solution.

[0056] Under nitrogen protection, 15 g of 12% ammonium persulfate aqueous solution was added dropwise to the 3,5-diamino-1,2,4-triazole aqueous solution at 75°C for 0.5 h, and then methylene succinic acid aqueous solution was added dropwise at 82°C for 1 h. After the addition was completed, the reaction was kept warm for 4.5 h, cooled to room temperature, and the pH of the system was adjusted to 8.0 with a 20% NaOH aqueous solution. The system was washed with anhydrous ethanol for 5 times, stirred, allowed to stand for stratification, and the brown precipitate was filtered out. It was vacuum dried at 80°C to constant weight and ground to obtain methylene succinic acid-3,5-diamino-1,2,4-triazole (IA-DMTA).

[0057] Example 5

[0058] A method for preparing a scale and corrosion inhibitor comprises the following steps:

[0059] Weigh 15.6 g of methylene succinic acid and dissolve it in 150 mL of distilled water to obtain a methylene succinic acid aqueous solution. Weigh 4.95 g of 3,5-diamino-1,2,4-triazole and dissolve it in 100 mL of distilled water to obtain a 3,5-diamino-1,2,4-triazole aqueous solution.

[0060] Under nitrogen protection, 15 g of 11% ammonium persulfate aqueous solution was added dropwise to the 3,5-diamino-1,2,4-triazole aqueous solution at 75°C for 0.5 h, and then methylene succinic acid aqueous solution was added dropwise at 82°C for 0.5 h. After the addition was completed, the reaction was kept warm for 4.5 h, cooled to room temperature, and the pH of the system was adjusted to 9.0 with a 20% NaOH aqueous solution. The system was washed with anhydrous ethanol for 5 times, stirred, allowed to stand for stratification, and the brown precipitate was filtered out. It was vacuum dried at 80°C to constant weight and ground to obtain methylene succinic acid-3,5-diamino-1,2,4-triazole (IA-DMTA).

[0061] Example 6

[0062] A method for preparing a scale and corrosion inhibitor comprises the following steps:

[0063] Weigh 16.25 g of methylene succinic acid and dissolve it in 150 mL of distilled water to obtain a methylene succinic acid aqueous solution. Weigh 4.95 g of 3,5-diamino-1,2,4-triazole and dissolve it in 100 mL of distilled water to obtain a 3,5-diamino-1,2,4-triazole aqueous solution.

[0064] Under nitrogen protection, 15 g of 11% ammonium persulfate aqueous solution was added dropwise to the 3,5-diamino-1,2,4-triazole aqueous solution at 75°C for 0.5 h, and then methylene succinic acid aqueous solution was added dropwise at 80°C for 0.5 h. After the addition was completed, the reaction was kept warm for 3.5 h, cooled to room temperature, and the pH of the system was adjusted to 8.2 with a 20% NaOH aqueous solution. The system was washed with anhydrous ethanol for 5 times, stirred, and allowed to stand for stratification. The brown precipitate was filtered out, dried in vacuo at 80°C to constant weight, and ground to obtain methylene succinic acid-3,5-diamino-1,2,4-triazole (IA-DMTA).

[0065] Scale and corrosion inhibition performance test

[0066] In order to test the scale and corrosion inhibition performance of the scale inhibitor in the high salt water system of the embodiment of the present invention, the test water is high salt water concentrated 4 times by tap water, and the scale inhibition test adopts the dynamic simulation scale inhibition test method. 10L of high salt water is added to the two water tanks of the small dynamic simulation test device respectively, and no agent is added to water tank 1, and the scale inhibitor prepared in the embodiment is added to water tank 2. At the same time, supplementary water is injected into the water tank on the cooling tower, and the preparation concentration of the supplementary water is the same as that of the water in the water tank. The inlet temperature is set to 35±0.1℃, the flow rate is adjusted to 70L / h, and when the concentration is 4 times, 2 A3 carbon steel test pieces (50mm×25mm×2mm) are hung in each of the two water tanks (water tank 1 is recorded as a blank test piece, and water tank 2 is recorded as a drug-added test piece), and sewage is discharged, and the concentration is maintained at about 4 times, and it is operated for 7 days.

[0067] The calculation formula of scale inhibition rate is:

[0068] Scale inhibition rate = (scaling amount of blank heating tube - scaling amount of added heating tube) / scaling amount of blank heating tube × 100%.

[0069] The corrosion rate is calculated as:

[0070] Corrosion rate (mm / a) = 8760 × 10 × (W0-W) / (A × D × T)

[0071] Where: W0 is the initial weight of the test piece before the test, g;

[0072] W is the initial weight of the corrosion specimen after the test, g;

[0073] 8760 is the number of hours equivalent to 1a, h / a;

[0074] 10 is the number of millimeters equivalent to 1 cm, mm / cm;

[0075] A is the surface area of ​​the test piece, 28 cm 2 ;

[0076] D is the density of the test piece, 7.850 g / cm 3 ;

[0077] T is the experimental time of the corrosion test, 168h.

[0078] The calculation formula of corrosion inhibition rate is:

[0079] Corrosion inhibition rate = (corrosion rate of blank test piece - corrosion rate of test piece) / corrosion rate of blank test piece × 100%.

[0080] Test results:

[0081] When the dosage of methylene succinic acid-3,5-diamino-1,2,4-triazole in Example 1-6 is 50 mg / L, the average scale inhibition rate is 91.6% and the average corrosion inhibition rate is 91.3%. When the dosage of methylene succinic acid-3,5-diamino-1,2,4-triazole is 80 mg / L, the average scale inhibition rate reaches 95.2% and the average corrosion inhibition rate reaches 94.6%.

[0082] Comparative Example 1

[0083] 4.95 g of 3,5-diamino-1,2,4-triazole was dissolved in 100 mL of distilled water to obtain an aqueous solution of 3,5-diamino-1,2,4-triazole as a scale inhibitor and corrosion inhibitor a.

[0084] The scale inhibition and corrosion inhibition performance was tested in the manner of the embodiment. When the dosage was 80 mg / L, the scale inhibition rate in the high salt water system was 34.8%, and the corrosion inhibition rate for A3 carbon steel was 68.7%.

[0085] Comparative Example 2

[0086] 13 g of methylene succinic acid was dissolved in 150 mL of distilled water to obtain a methylene succinic acid aqueous solution as a scale inhibitor and corrosion inhibitor b.

[0087] The scale inhibition and corrosion inhibition performance was tested in the manner of the embodiment. When the dosage was 80 mg / L, the scale inhibition rate in the high salt water system was 73.6%, and the corrosion inhibition rate for A3 carbon steel was 58.4%.

[0088] Comparative Example 3

[0089] Dissolve 4.95 g of 3,5-diamino-1,2,4-triazole in 100 mL of distilled water to obtain an aqueous solution of 3,5-diamino-1,2,4-triazole.

[0090] Dissolve 13 g of methylene succinic acid in 150 mL of distilled water to obtain an aqueous solution of methylene succinic acid.

[0091] The above 3,5-diamino-1,2,4-triazole aqueous solution and methylene succinic acid aqueous solution are mixed evenly to obtain scale inhibitor c.

[0092] The scale inhibition and corrosion inhibition performance was tested in the manner of the embodiment. When the dosage was 80 mg / L, the scale inhibition rate in the high salt water system was 65.2%, and the corrosion inhibition rate for A3 carbon steel was 64.7%.

[0093] Comparative Example 4

[0094] Weigh 3.12 g of methylene succinic acid and dissolve it in 100 mL of distilled water to obtain a methylene succinic acid aqueous solution. Weigh 2.32 g of 3-amino-5-mercapto-1,2,4-triazole and dissolve it in 200 mL of distilled water to obtain a 3-amino-5-mercapto-1,2,4-triazole aqueous solution.

[0095] Under nitrogen protection, 5.5 g of 10% ammonium persulfate aqueous solution was added dropwise to the 3-amino-5-mercapto-1,2,4-triazole aqueous solution at 75°C, and the addition time was controlled to be 0.5 h. Then, methylene succinic acid aqueous solution was added dropwise at 80°C, and the addition time was controlled to be 0.5 h. After the addition was completed, the reaction was kept warm for 3.5 h, and then cooled to room temperature. The pH of the system was adjusted to 8.8 with a 20% mass concentration NaOH aqueous solution, washed with anhydrous ethanol for 5 times, stirred, and allowed to stand for stratification. The brown precipitate was filtered out, vacuum dried at 80°C to constant weight, and ground to obtain methylene succinic acid-3-amino-5-mercapto-1,2,4-triazole as a scale inhibitor and corrosion inhibitor d.

[0096] The scale inhibition and corrosion inhibition performance was tested in the manner of the embodiment. When the dosage was 80 mg / L, the scale inhibition rate in the high salt water system was 76.4%, and the corrosion inhibition rate for A3 carbon steel was 72.1%.

[0097] In summary, the scale and corrosion inhibitor methylene succinic acid-3,5-diamino-1,2,4-triazole prepared in the embodiment of the present invention can be used in industrial circulating cooling water in a high-salt water system, with a scale inhibition rate of 95.2%. It has certain corrosion inhibition performance for A3 carbon steel, with a corrosion inhibition rate of up to 94.6%, which can significantly improve the service life of the equipment, significantly reduce scaling on the surface of the heat exchange equipment, increase the heat exchange rate, reduce energy consumption, and ensure the safe, efficient and stable operation of the industrial circulating cooling water system, which is of great significance for promoting sustainable development in the industrial field.

[0098] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A scale and corrosion inhibitor, characterized in that: The structure of the scale and corrosion inhibitor is shown in Formula I: Formula Ⅰ.

2. The method for preparing the scale and corrosion inhibitor according to claim 1, characterized in that: The method comprises the following steps: step a, dissolving 3,5-diamino-1,2,4-triazole and methylene succinic acid in water respectively to obtain a 3,5-diamino-1,2,4-triazole aqueous solution and a methylene succinic acid aqueous solution; Step b, under an inert atmosphere, adding an initiator to the aqueous solution of 3,5-diamino-1,2,4-triazole, mixing evenly, adding an aqueous solution of methylene succinic acid, heating to carry out an addition reaction, and obtaining a scale inhibitor as shown in formula I; The initiator is an aqueous solution of ammonium persulfate with a mass concentration of 9% to 12%.

3. The method for preparing the scale and corrosion inhibitor according to claim 2, characterized in that: The molar ratio of the 3,5-diamino-1,2,4-triazole to methylene succinic acid is 1:2.0 to 1:2.

5.

4. The method for preparing the scale and corrosion inhibitor according to claim 2 or 3, characterized in that: The mass concentration of the 3,5-diamino-1,2,4-triazole aqueous solution is 4% to 5%; and / or The mass concentration of the methylene succinic acid aqueous solution is 7% to 10%; and / or The mass ratio of ammonium persulfate to 3,5-diamino-1,2,4-triazole in the ammonium persulfate aqueous solution is 0.2:1 to 0.4:

1.

5. The method for preparing the scale and corrosion inhibitor according to claim 2, characterized in that: The temperature of the addition reaction is 76° C. to 82° C., and the reaction time is 4 h to 6 h.

6. The method for preparing a scale and corrosion inhibitor according to claim 2, characterized in that: The methylene succinic acid aqueous solution is added in a slow dropwise manner, and the dropwise addition time is 0.5h~1h.

7. A scale and corrosion inhibitor composition, characterized in that: Contains the scale and corrosion inhibitor according to claim 1.

8. Use of the scale inhibitor and corrosion inhibitor according to claim 1 in an industrial circulating cooling water system of a high-salt water system.

9. The use according to claim 8, characterized in that The added amount of the scale inhibitor and corrosion inhibitor is 50 mg / L to 80 mg / L.

Images