A cleaning agent for preventing scale and purifying steam and a preparation method thereof

Abstract

This invention relates to the field of boiler water treatment technology, and particularly to a boiler cleaning agent with scale prevention and steam purification functions, and its preparation method. The agent comprises the following components by weight: 20-40 parts of a self-made scale inhibitor, 3-5 parts of a penetrant, 20-30 parts of a dispersant, 1-5 parts of an oxygen scavenger, 0.003-0.017 parts of a catalyst, and 100-150 parts of water. The boiler cleaning agent prepared by this invention is suitable for medium and low-pressure boilers and has the functions of corrosion inhibition, scale inhibition, steam purification, and also inhibits the formation of microbial sludge.

Description

Technical Field

[0001] This invention relates to the field of boiler water treatment technology, and in particular to a boiler cleaning agent with anti-scaling and steam purification functions and its preparation method. Background Technology

[0002] Boilers are a widely used type of equipment in my country, extensively applied in thermal power generation, petrochemicals, mining, and other fields. With their widespread use, their drawbacks have become increasingly apparent, the most concerning being boiler explosions. Boilers are unlikely to explode under normal use; the primary cause of explosions lies in the weakening of the boiler's materials. When the pressure inside the furnace exceeds the material's strength, an explosion is likely to occur. Therefore, weakened material strength is the root cause of boiler explosions. Researchers have studied material weakening and found that it is usually caused by aging, corrosion, and overheating, with scale being one of the main factors leading to corrosion. Boiler water is primarily industrial water, containing abundant calcium carbonate (Ca). + Mg + Fe + Metal cations and such as OH - CO3 - SO4 - Anions, such as limescale, accumulate as boiler water evaporates, leading to increased limescale concentration. In addition, microbial sludge is another cause of material corrosion. Currently, the most common method is to add water treatment agents to prevent limescale formation, while simultaneously adding bactericides to inhibit microbial growth and reduce microbial sludge production.

[0003] Water treatment agents are divided into inorganic corrosion inhibitors and organic corrosion inhibitors. Inorganic corrosion inhibitors mainly include chromates, molybdates, tungstates, and arsenic compounds. These inorganic corrosion inhibitors are environmentally harmful and expensive, thus limiting their use. Commonly used organic corrosion inhibitors can be further divided into amine corrosion inhibitors, aldehyde corrosion inhibitors, alkynyl alcohol corrosion inhibitors, organophosphorus corrosion inhibitors, sulfur compound corrosion inhibitors, carboxylic acid corrosion inhibitors, and sulfonic acid corrosion inhibitors, each with its own advantages and disadvantages. For example, CN106434047A discloses "a rapid descaling agent for boilers," which is prepared using tartaric acid, aminosulfonic acid, trisodium phosphate, sodium tripolyphosphate, penetrant, sodium hydroxymethyl cellulose, etc. as raw materials. The descaling agent prepared by this patent has a good boiler descaling effect and can maintain the scale inhibition effect for a long time. For example, CN113044998B discloses "a boiler feedwater agent and its preparation method and application," which is prepared using sodium sulfite and sodium metabisulfite as the main raw materials. The feedwater agent prepared by this patent has a good deoxygenation effect, and when used in combination with polyaspartic acid, it can quickly play a role in corrosion and scale inhibition. However, the aforementioned patent uses phosphorus- and sulfur-containing compounds as corrosion and scale inhibitors, which is more difficult in the later treatment process and is likely to have an impact on the environment.

[0004] For example, CN111233178A discloses "a phosphorus-free composite boiler cleaning agent for low-pressure boilers and its preparation method". It is prepared by using deoxygenating components, slow-release components and scale inhibitors as the main raw materials. The cleaning agent prepared by this patent does not contain phosphorus and can eliminate dissolved oxygen corrosion in boiler water, and can play a role in corrosion inhibition and scale inhibition. However, this patent only mentions that the product is suitable for low-pressure boilers and cannot solve the problem of medium-pressure boilers.

[0005] Therefore, it is urgent to develop a boiler cleaning agent that is suitable for medium and low pressure boilers, has the functions of corrosion inhibition, scale inhibition and steam purification, and can also inhibit the production of microbial sludge. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a boiler cleaning agent with anti-scaling and steam purification functions, as well as its preparation method. The boiler cleaning agent of this invention is suitable for medium and low-pressure boilers and has the functions of corrosion inhibition, scale inhibition, steam purification, and also inhibiting the formation of microbial sludge.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] The present invention provides a tank cleaning agent with anti-scaling and steam purification functions, comprising the following components by weight: 20-40 parts of self-made scale inhibitor, 3-5 parts of penetrant, 20-30 parts of dispersant, 1-5 parts of oxygen remover, 0.003-0.017 parts of catalyst and 100-150 parts of water.

[0009] In some embodiments, the self-made scale inhibitor has the following structure:

[0010]

[0011] Where 10≤a≤15, 6≤b≤10.

[0012] Currently, most commercially available scale inhibitors are phosphorus-containing, which cause some environmental pollution and cannot meet current environmental trends. Polyaspartic acid is a relatively environmentally friendly scale inhibitor with good scale inhibition effects on calcium carbonate and calcium sulfate. However, studies have shown that polyaspartic acid loses its function when the local temperature is too high, resulting in poor thermal stability. The current common method to solve this problem is physical compounding, which is cumbersome to use. The applicant introduces a large number of benzene ring structures into the structure of the self-made scale inhibitor, which can play a π-π stacking role. This not only enhances the stability of the molecular structure in conjunction with hydrogen bonding forces, but also enhances the temperature resistance of the self-made scale inhibitor.

[0013] While some common scale inhibitors can effectively inhibit corrosion and scale formation, their effectiveness is not prominent in certain environments, such as under the influence of pH range. The self-made scale inhibitor in this application has a large number of amide groups, which increases its acid and alkali resistance, allowing it to be used in a wider range of feedwater pH. In addition, the self-made scale inhibitor also contains a large number of hydrogen bond acceptors and hydrogen bond donors, which can be adsorbed onto the boiler surface to form a protective film and thus inhibit boiler corrosion.

[0014] Furthermore, the applicant discovered that commonly used scale inhibitors mainly work by chelating metal cations in boiler water to reduce their concentration and thus reduce scale formation. However, water contains a large number of microorganisms with extremely strong reproductive capabilities. During the metabolism of these microorganisms, a large amount of microbial sludge is generated, which is also one of the causes of scale formation. Therefore, the elimination of microorganisms cannot be ignored. The scale inhibitor in this application contains a small amount of quaternary ammonium salt structure, which not only increases the hydrophilicity of the self-made scale inhibitor but also inhibits the reproduction of microorganisms, thereby reducing the formation of microbial sludge.

[0015] In some embodiments, the method for preparing the homemade scale inhibitor includes the following steps:

[0016] S1. The compound shown in Formula I

[0017] The compound E was obtained by adding trimethyliodosilane to a third solvent, stirring at room temperature for 4–6 h, adding triethylamine, stirring for 20–25 min, removing the solvent under reduced pressure, adding ethanol, centrifuging and filtering.

[0018] S2. Mix polysuccinimide with water, then dissolve compound E from step S1 in sodium hydroxide solution and add it dropwise to the polysuccinimide and water mixture at a dropping rate of 10–15 mL / min. Stir at room temperature for 26–30 h. After the reaction is complete, adjust the pH to 7–8, add ethanol, centrifuge, filter, and dry to obtain the compound shown in Formula II.

[0019]

[0020] S3. Mix the compound shown in Formula II in step S2, tetramethylammonium chloride and methanol, let stand for 3-5 hours, and then exchange ions to obtain the self-made scale inhibitor.

[0021] In some embodiments, the method for preparing the compound represented by Formula I includes the following steps:

[0022] S11. Ethylenediamine and methyl acrylate are subjected to a Michael addition reaction to obtain compound A;

[0023] S12. Compound A from step S11 is subjected to an amidation reaction with ethylenediamine to obtain compound B;

[0024] S13. Dissolve compound B and the first acid-binding agent from step S12 in the first solvent, cool to -5 to 5°C, slowly add benzyl chloroformate to it, and after the addition is complete, heat to room temperature and stir for 4 to 5 hours to obtain compound C.

[0025] S14. Add compound C from step S13 and 2-naphthaldehyde to the second solvent and mix. Heat to 50-60℃ and stir for 6-7 hours. Then cool the reaction solution to room temperature, add sodium borohydride and continue stirring for 40-50 minutes. After the reaction is completed, quench at low temperature and then extract and concentrate under reduced pressure to obtain compound D.

[0026] S15. Mix compound D from step S14 with deionized water and stir until homogeneous. Add the second acid-binding agent and control the temperature to room temperature. Add chloroacetic acid aqueous solution dropwise to the system. After the addition is complete, stir at a constant temperature for 1-3 hours. After the reaction is complete, concentrate under reduced pressure and pass through a chromatographic column to obtain the compound shown in Formula I.

[0027] In some embodiments, in step S1, the first solvent is acetonitrile.

[0028] In some embodiments, in step S2, the mass ratio of the polysuccinimide to compound E is 1:(0.3 to 0.6).

[0029] Preferably, in step S2, the mass ratio of the polysuccinimide to compound E is 1:0.4.

[0030] This application, by adjusting the mass ratio of polysuccinimide to compound E, can prevent the increase in benzene ring content from weakening the hydrophilicity of the self-made scale inhibitor, thereby reducing its scale inhibition performance. At the same time, it can also prevent the weakening of the Pi-P-P accumulation effect, which would lead to a decrease in the temperature resistance of the self-made scale inhibitor.

[0031] In some embodiments, step S11 specifically involves: mixing ethylenediamine with anhydrous methanol and then adding it dropwise to methyl acrylate, purging with an inert protective gas, and reacting at a constant temperature of 28–33°C for 24–26 hours to obtain compound A.

[0032] In some embodiments, step S12 specifically involves: mixing compound A with anhydrous methanol, adding ethylenediamine dropwise, and reacting at a constant temperature of 23–27°C for 24–26 hours to obtain compound B.

[0033] In some embodiments, in step S13, the first acid-binding agent is one or more of triethylamine, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0034] In some embodiments, in step S13, the second solvent is one or more of toluene, tetrahydrofuran, and anhydrous methanol.

[0035] In some embodiments, in step S13, the molar ratio of compound B to benzyl chloroformate is 1:(1.1 to 1.2).

[0036] Preferably, in step S13, the molar ratio of compound B to benzyl chloroformate is 1:1.15.

[0037] This application enables the protection of one amino group in compound B by adjusting the molar ratio of compound B to benzyl chloroformate, while allowing the other three amino groups to participate in the reaction in the next step.

[0038] In some embodiments, in step S14, the third solvent is anhydrous methanol or anhydrous ethanol.

[0039] In some embodiments, in step S14, the molar ratio of compound C to 2-naphthaldehyde is 1:(2 to 2.2).

[0040] Preferably, in step S14, the molar ratio of compound C to 2-naphthaldehyde is 1:2.1.

[0041] This application enables the substitution reaction between 2-naphthoaldehyde and two amino groups in the structure of compound C by adjusting the molar ratio of compound C to 2-naphthoaldehyde, thereby providing a large number of benzene ring structures, which improves the π-π stacking ability between molecules and thus enhances the high-temperature resistance of the self-made scale inhibitor.

[0042] In some embodiments, in step S15, the second acid-binding agent is one or more of sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0043] In some embodiments, in step S15, the molar ratio of compound D to chloroacetic acid is 1:(1 to 1.2).

[0044] Preferably, in step S15, the molar ratio of compound D to chloroacetic acid is 1:1.1.

[0045] In some embodiments, the dispersant is one or more selected from acrylic acid, polyacrylic acid, sodium polyacrylate, sodium lignosulfonate, and sodium dodecyl sulfonate.

[0046] This application does not specifically limit the type of penetrant, but uses penetrants commonly used by those skilled in the art, including but not limited to JFC-1.

[0047] In some embodiments, the oxygen scavenger is hydrazine hydrate; the catalyst is hydroquinone.

[0048] This application selects a specific deoxygenator that can replace sodium sulfite and sodium metabisulfite to prevent the decomposition and generation of toxic flue gas in medium-pressure boilers. In addition, a specific catalyst is selected to promote the deoxygenation rate of hydrazine hydrate at low temperatures.

[0049] In some embodiments, the mass ratio of the self-made scale inhibitor, oxygen scavenger, and catalyst is 1:(0.06-0.1):(0.0002-0.0004).

[0050] Preferably, the mass ratio of the self-made scale inhibitor, oxygen scavenger and catalyst is 1:0.08:0.0003.

[0051] This application, by adjusting the mass ratio of self-made scale inhibitor, oxygen scavenger and catalyst, can prevent ammonia corrosion of copper components caused by excessively high pH value of the feed water.

[0052] Another aspect of the present invention provides a method for preparing a tank cleaning agent with anti-scaling and steam purification functions, comprising the following steps: mixing a self-made scale inhibitor, penetrant, dispersant, oxygen remover, catalyst and water, and adjusting the pH of the system to 8-9 to obtain the tank cleaning agent.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] (1) The cleaning agent of the present invention is prepared by self-made scale inhibitor, penetrant, dispersant, deoxygenator, catalyst and water. It is suitable for medium and low pressure boilers and has the functions of corrosion inhibition, scale inhibition and steam purification, and can also inhibit the generation of microbial sludge.

[0055] (2) The scale inhibitor of the present invention contains a benzene ring structure, which can undergo intermolecular π-π stacking and enhance the stability of the molecular structure through synergistic hydrogen bonding. At the same time, it improves the high temperature resistance of the self-made scale inhibitor, making it suitable for use in low and medium pressure boilers. The amide group can improve the acid and alkali resistance of the self-made scale inhibitor, enabling it to be used in a wider range of feedwater pH. The self-made scale inhibitor also contains a large number of hydrogen bond acceptors and hydrogen bond donors that can be adsorbed onto the boiler body surface to form a protective film and inhibit corrosion. It also contains a quaternary ammonium salt structure that can inhibit the reproduction of microorganisms and thus reduce the generation of microbial sludge.

[0056] (3) This application can improve the corrosion and scale inhibition performance of the cleaning agent by using self-made scale inhibitor, penetrant and deoxygenator in synergy, and at the same time can make the self-made scale inhibitor adhere better to the surface of the boiler body to prevent the growth of microorganisms and the generation of biological mud. Detailed Implementation

[0057] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0058] In the following preparation examples, embodiments, and comparative examples, polysuccinimide was purchased from Wuhan Huaxiang Kejie Biotechnology Co., Ltd.; JFC-1 was purchased from Jinan Xinzhan Chemical Industry and Trade Co., Ltd.

[0059] Preparation Example 1

[0060] The preparation method of the homemade scale inhibitor includes the following steps:

[0061] (1) Mix 10g of ethylenediamine with 100mL of anhydrous methanol and add it dropwise to 14.3g of methyl acrylate. Inert protective gas is introduced and the mixture is kept at 30℃ for 25h to obtain compound A.

[0062] (2) Mix 50g of compound A from step S1 with 500mL of anhydrous methanol, add 8g of ethylenediamine dropwise, and react at 25℃ for 25h to obtain compound B;

[0063] (3) Dissolve 70g of compound B from step S2 and 16g of triethylamine in 700mL of toluene, cool to 0℃, slowly add 26.6g of benzyl chloroformate, and then heat to 27℃ and stir for 4.5h to obtain compound C;

[0064] (4) Add 80g of compound C from step S3 and 40.3g of 2-naphthaldehyde to 1000mL of methanol and mix. Heat to 55℃ and stir for 6.5h. Then cool the reaction solution to 27℃, add 3g of sodium borohydride and continue stirring for 45min. After the reaction is completed, quench at -5℃ and then extract and concentrate under reduced pressure to obtain compound D.

[0065] (5) Mix 100g of compound D from step S4 with 1000mL of deionized water and stir until homogeneous. Add 15g of sodium carbonate to the mixture and control the temperature to 27℃. Add a mixture of 11g of chloroacetic acid and 20mL of water dropwise to the system. After the addition is complete, stir at a constant temperature for 2h. After the reaction is complete, concentrate the solution under reduced pressure and pass it through a chromatographic column to obtain the compound shown in Formula I.

[0066] (6) Add 100g of the compound shown in Formula I in step S5 and 40g of trimethyliodosilane to acetonitrile, stir at 27°C for 5h, add 3.35g of triethylamine, continue stirring for 23min, remove the solvent under reduced pressure, add ethanol, centrifuge and filter to obtain compound E;

[0067] (7) Mix 250g of polysuccinimide with 1500mL of water, then dissolve 100g of compound E from step S6 in 500mL of 10% sodium hydroxide solution, and add it dropwise to the mixed solution of polysuccinimide and water at a dropping rate of 13mL / min. Stir at room temperature for 28h. After the reaction is complete, adjust the pH to 7.5, add ethanol, centrifuge, filter and dry to obtain the compound shown in formula II.

[0068] (8) Mix 300g of the compound shown in Formula II from step S7, 200g of tetramethylammonium chloride, and 5000mL of methanol, let stand for 4h, and then perform ion exchange to obtain a self-made scale inhibitor. The structure of the self-made scale inhibitor is as follows:

[0069]

[0070] Where a = 15 and b = 6.

[0071] Preparation Example 2

[0072] The preparation method of the self-made scale inhibitor is the same as that in preparation example 1, except that the amount of benzyl chloroformate added in step (3) is 46.2g.

[0073] Preparation Example 3

[0074] The preparation method of the self-made scale inhibitor is the same as that in Preparation Example 1, except that benzyl chloroformate is not introduced.

[0075] Preparation Example 4

[0076] The preparation method of the self-made scale inhibitor is the same as that in preparation example 1, except that the amount of 2-naphthaldehyde added in step (4) is 20g.

[0077] Preparation Example 5

[0078] The preparation method of the self-made scale inhibitor is the same as that in preparation example 1, except that the amount of 2-naphthaldehyde added in step (4) is 60g.

[0079] Preparation Example 6

[0080] The preparation method of the homemade scale inhibitor is the same as in Preparation Example 1, except that the amount of compound E added in step (7) is 280g. The structure of the homemade scale inhibitor is as follows:

[0081]

[0082] Where a = 1.2 and b = 1.4.

[0083] Preparation Example 7

[0084] The preparation method of the homemade scale inhibitor includes the following steps:

[0085] (1) Mix 10g of ethylenediamine with 100mL of anhydrous methanol and add it dropwise to 14.3g of methyl acrylate. Inert protective gas is introduced and the mixture is kept at 30℃ for 25h to obtain compound A.

[0086] (2) Mix 50g of compound A from step S1 with 500mL of anhydrous methanol, add 8g of ethylenediamine dropwise, and react at 25℃ for 25h to obtain compound B;

[0087] (3) Dissolve 70g of compound B from step S2 and 16g of triethylamine in 700mL of toluene, cool to 0℃, slowly add 26.6g of benzyl chloroformate, and then heat to 27℃ and stir for 4.5h to obtain compound C;

[0088] (4) Add 80g of compound C from step S3 and 40.3g of 2-naphthaldehyde to 1000mL of methanol and mix. Heat to 55℃ and stir for 6.5h. Then cool the reaction solution to 27℃, add 3g of sodium borohydride and continue stirring for 45min. After the reaction is completed, quench at -5℃ and then extract and concentrate under reduced pressure to obtain compound D.

[0089] (5) Mix 100g of compound D from step S4 with 1000mL of deionized water and stir until homogeneous. Add 15g of sodium carbonate to the mixture and control the temperature to 27℃. Add a mixture of 11g of chloroacetic acid and 20mL of water dropwise to the system. After the addition is complete, stir at a constant temperature for 2h. After the reaction is complete, concentrate the solution under reduced pressure and pass it through a chromatographic column to obtain the compound shown in Formula I.

[0090] (6) Add 100g of the compound shown in Formula I in step S5 and 40g of trimethyliodosilane to acetonitrile, stir at 27°C for 5h, add 3.35g of triethylamine, continue stirring for 23min, remove the solvent under reduced pressure, add ethanol, centrifuge and filter to obtain compound E;

[0091] (7) Mix 250g of polysuccinimide with 1500mL of water, then dissolve 100g of compound E from step S6 in 500mL of 10% sodium hydroxide solution and add it dropwise to the mixture of polysuccinimide and water at a dropping rate of 13mL / min. Stir at room temperature for 28h. After the reaction is complete, adjust the pH to 7.5, add ethanol, centrifuge, filter and dry to obtain the self-made scale inhibitor.

[0092] Example 1

[0093] This embodiment provides a tank cleaning agent with anti-scaling and steam purification functions, comprising the following components by weight: 30 parts of self-made scale inhibitor, 4 parts of JFC-1, 25 parts of sodium dodecyl sulfonate, 2.4 parts of hydrazine hydrate, 0.009 parts of hydroquinone, and 130 parts of water.

[0094] The self-made scale inhibitor was prepared in Preparation Example 1.

[0095] The preparation method of the tank cleaner with anti-scaling and steam purification functions in this embodiment includes the following steps: mixing the self-made scale inhibitor, JFC-1, sodium dodecyl sulfonate, hydrazine hydrate, hydroquinone and water, and then adding a 10% sodium hydroxide solution to adjust the pH of the system to 8, thus obtaining the tank cleaner.

[0096] Example 2

[0097] This embodiment provides a tank cleaning agent with anti-scaling and steam purification functions, comprising the following components by weight: 20 parts of self-made scale inhibitor, 3 parts of JFC-1, 20 parts of sodium dodecyl sulfonate, 1.2 parts of hydrazine hydrate, 0.004 parts of hydroquinone, and 70 parts of water.

[0098] The self-made scale inhibitor was prepared in Preparation Example 1.

[0099] The preparation method of the tank cleaner with anti-scaling and steam purification functions in this embodiment includes the following steps: mixing the self-made scale inhibitor, JFC-1, sodium dodecyl sulfonate, hydrazine hydrate, hydroquinone and water, and then adding a 10% sodium hydroxide solution to adjust the pH of the system to 9, thus obtaining the tank cleaner.

[0100] Example 3

[0101] This embodiment provides a tank cleaner with anti-scaling and steam purification functions, comprising the following components by weight: 40 parts of self-made scale inhibitor, 5 parts of JFC-1, 30 parts of sodium dodecyl sulfonate, 4 parts of hydrazine hydrate, 0.016 parts of hydroquinone, and 150 parts of water.

[0102] The self-made scale inhibitor was prepared in Preparation Example 1.

[0103] The preparation method of the tank cleaner with anti-scaling and steam purification functions in this embodiment includes the following steps: mixing the self-made scale inhibitor, JFC-1, sodium dodecyl sulfonate, hydrazine hydrate, hydroquinone and water, and then adding a 10% sodium hydroxide solution to adjust the pH of the system to 8, thus obtaining the tank cleaner.

[0104] Example 4

[0105] A tank cleaning agent with anti-scaling and steam purification functions and its preparation method are described. The specific implementation method is the same as in Example 1, except that the amount of hydrazine hydrate is 13 parts.

[0106] Example 5

[0107] A tank cleaning agent with anti-scaling and steam purification functions and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that the self-made scale inhibitor is prepared in Example 2.

[0108] Example 6

[0109] A tank cleaning agent with anti-scaling and steam purification functions and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that the self-made scale inhibitor is prepared by Example 3.

[0110] Example 7

[0111] A tank cleaning agent with anti-scaling and steam purification functions and its preparation method are described. The specific implementation method is the same as that in Example 1, except that the self-made scale inhibitor is prepared in Example 4.

[0112] Example 8

[0113] A tank cleaning agent with anti-scaling and steam purification functions and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that the self-made scale inhibitor is obtained from Preparation Example 5.

[0114] Example 9

[0115] A tank cleaning agent with anti-scaling and steam purification functions and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that the self-made scale inhibitor is obtained from Preparation Example 6.

[0116] Example 10

[0117] A tank cleaning agent with anti-scaling and steam purification functions and its preparation method are described. The specific implementation method is the same as in Example 1, except that the self-made scale inhibitor is prepared in Example 7.

[0118] Example 11

[0119] A tank cleaning agent with anti-scaling and steam purification functions and its preparation method are disclosed. The specific implementation method is the same as in Example 1, except that sodium sulfite in equal parts by mass is used instead of hydrazine hydrate.

[0120] Comparative Example 1

[0121] A tank cleaning agent with anti-scaling and steam purification functions and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that citric acid of equal mass is used instead of the self-made scale inhibitor.

[0122] Performance testing:

[0123] (1) Scale inhibition rate: The cleaning agent was prepared into a mixed solution with a concentration of 80 mg / L and tested according to B / T16632-2008 "Determination of scale inhibition performance of water treatment agents by calcium carbonate deposition method".

[0124] (2) Corrosion rate: According to GBT18175 "Determination of corrosion inhibition performance of water treatment agents by rotating plate method", the dosage of cleaning agent is 50mg / L, the temperature is 45℃, and the treatment time is 72h.

[0125] (3) High temperature resistance: Place the cleaning agent at 400℃ for 10 hours, take it out and cool it down to 27℃, and then test its scale inhibition rate according to test method (1).

[0126] (4) Antibacterial test: Take two beakers of the same volume as containers. Fill one beaker with 1L of tap water as a blank group, and add 1L of tap water and 10g of cleaning agent to the other beaker. Soak at room temperature for 72 hours and take water to test the total number of colonies for comparison.

[0127] The cleaning agents prepared in each embodiment and comparative example were tested according to the above test methods, and the test results are shown in Table 1.

[0128] Table 1

[0129]

[0130] Table 1 shows that the tank cleaning agents prepared in Examples 1-3 have good scale inhibition rate, high temperature resistance, and resistance to microbial growth, and low corrosivity. In Example 4, the pH of the system increased slightly due to the change in the mass ratio of the self-made scale inhibitor, hydrazine hydrate, and hydroquinone, resulting in a slight increase in corrosivity. However, with the increase in the hydrazine hydrate content, its deoxygenation efficiency increased, thus slightly increasing the scale inhibition rate. In Example 5, the molar ratio of compound B to benzyl chloroformate was changed, which protected the two amino groups in compound B, reducing the benzene ring content in the tank cleaning agent and thus weakening the π-π packing strength and reducing the temperature resistance. In Example 6, the absence of benzyl chloroformate resulted in the partial incorporation of 2-naphthaldehyde and chloroacetic acid into the amino groups, leading to a decrease in the content of polysuccinimide-incorporated products and a slight decrease in scale inhibition rate. In Example 7, the change in the molar ratio of compound C to 2-naphthaldehyde reduced the benzene ring content in the tank cleaning agent, weakening the π-π packing strength and thus improving the temperature resistance of the tank cleaning agent. The following examples illustrate the decline in scale inhibition performance: Example 8: Due to the change in the molar ratio of compound C to 2-naphthaldehyde, the benzene ring content in the self-made scale inhibitor increased, but the carboxyl group content decreased, resulting in a slight decrease in scale inhibition performance but a slight increase in high-temperature resistance. Example 9: Due to the change in the mass ratio of polysuccinimide to compound E, the benzene ring content in the self-made scale inhibitor increased, enhancing the temperature resistance of the tank cleaner. However, due to the excessive benzene ring content, the hydrophilicity of the tank cleaner decreased slightly, resulting in a slight decrease in scale inhibition rate. Example 10: Because ion exchange was not performed during the synthesis of the self-made scale inhibitor, the quaternary ammonium salt structure in the self-made scale inhibitor decreased, resulting in a decrease in the antimicrobial performance of the tank cleaner. Example 11: Because an equal mass of sodium sulfite was used instead of hydrazine hydrate, sodium sulfite decomposed at high temperatures, leading to a decrease in the high-temperature deoxygenation rate of the tank cleaner and thus a decrease in scale inhibition rate. Comparative Example 1: Because an equal mass of citric acid was used instead of the self-made scale inhibitor, both the antimicrobial performance and high-temperature resistance of the tank cleaner decreased.

[0131] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tank cleaning agent with anti-scaling and steam purification functions, characterized in that, It comprises the following components by weight: 20-40 parts of self-made scale inhibitor, 3-5 parts of penetrant, 20-30 parts of dispersant, 1-5 parts of oxygen scavenger, 0.003-0.017 parts of catalyst, and 100-150 parts of water; The structure of the self-made scale inhibitor is as follows: ； Where 10≤a≤15, 6≤b≤10.

2. A tank cleaning agent with anti-scaling and steam purification functions according to claim 1, characterized in that, The preparation method of the self-made scale inhibitor includes the following steps: S1. The compound shown in Formula I (I) Add trimethyliodosilane to the first solvent, stir at room temperature for 4-6 h, then add triethylamine, continue stirring for 20-25 min, remove the solvent under reduced pressure, add ethanol, centrifuge and filter to obtain compound E; S2. Mix polysuccinimide with water, then dissolve compound E from step S1 in sodium hydroxide solution and add it dropwise to the polysuccinimide and water mixture at a dropping rate of 10-15 mL / min. Stir at room temperature for 26-30 h. After the reaction is complete, adjust the pH to 7-8, add ethanol, centrifuge, filter and dry to obtain the compound shown in Formula II. （Ⅱ）； S3. Mix the compound shown in Formula II in step S2, tetramethylammonium chloride and methanol, let stand for 3-5 hours, and then perform ion exchange to obtain the self-made scale inhibitor.

3. A tank cleaning agent with anti-scaling and steam purification functions according to claim 2, characterized in that, The method for preparing the compound represented by Formula I includes the following steps: S11. Ethylenediamine and methyl acrylate are subjected to a Michael addition reaction to obtain compound A; S12. Compound A from step S11 is subjected to an amidation reaction with ethylenediamine to obtain compound B; S13. Dissolve compound B and the first acid-binding agent from step S12 in the second solvent, cool to -5~5℃, slowly add benzyl chloroformate to it, and after the addition is complete, heat to room temperature and stir for 4~5 hours to obtain compound C. S14. Add compound C from step S13 and 2-naphthaldehyde to the third solvent and mix. Heat to 50-60℃ and stir for 6-7 hours. Then cool the reaction solution to room temperature, add sodium borohydride and continue stirring for 40-50 minutes. After the reaction is completed, quench at low temperature and then extract and concentrate under reduced pressure to obtain compound D. S15. Mix compound D from step S14 with deionized water and stir until homogeneous. Add the second acid-binding agent and control the temperature to room temperature. Add chloroacetic acid aqueous solution dropwise to the system. After the addition is complete, stir at a constant temperature for 1-3 hours. After the reaction is complete, concentrate under reduced pressure and pass through a chromatographic column to obtain the compound shown in Formula I.

4. A tank cleaning agent with anti-scaling and steam purification functions according to claim 2, characterized in that, In step S3, the mass ratio of the polysuccinimide to compound E is 1:(0.3~0.6).

5. A tank cleaning agent with anti-scaling and steam purification functions according to claim 3, characterized in that, In step S13, the molar ratio of compound B to benzyl chloroformate is 1:(1.1~1.2).

6. A tank cleaning agent with anti-scaling and steam purification functions according to claim 3, characterized in that, In step S14, the molar ratio of compound C to 2-naphthaldehyde is 1:(2~2.2).

7. A tank cleaning agent with anti-scaling and steam purification functions according to claim 1, characterized in that, The dispersant is one or more selected from acrylic acid, polyacrylic acid, sodium polyacrylate, sodium lignosulfonate, and sodium dodecyl sulfonate.

8. A tank cleaning agent with anti-scaling and steam purification functions according to claim 1, characterized in that, The mass ratio of the self-made scale inhibitor, oxygen scavenger, and catalyst is 1:(0.06~0.1):(0.0002~0.0004).

9. A method for preparing a tank cleaning agent with anti-scaling and steam purification functions as described in any one of claims 1 to 8, characterized in that, The process includes the following steps: mixing homemade scale inhibitor, penetrant, dispersant, oxygen remover, and catalyst with water, and then adjusting the pH of the system to 8-9 to obtain the tank cleaner.

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