Corrosion and scale inhibitor for green circulating cooling water and preparation method of corrosion and scale inhibitor

Abstract

The invention discloses a corrosion and scale inhibitor for green circulating cooling water and a preparation method of the corrosion and scale inhibitor, and the scale inhibitor is prepared from the following components in parts by weight: 3 to 6 parts of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 6 to 12 parts of 1-hydroxyethylidene-1, 1-diphosphonic acid, 6 to 15 parts of 2-phosphonobutane-1, 2, 4-tricarboxylic acid, 6 to 12 parts of polyepoxysuccinic acid and 6 to 12 parts of polyaspartic acid. The method comprises the following steps: adding an acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 1-hydroxyethylidene-1, 1-diphosphonic acid, 2-phosphonobutane-1, 2, 4-tricarboxylic acid, polyepoxysuccinic acid, polyaspartic acid and water into a stirrer, and stirring at room temperature for 10 minutes to obtain the corrosion and scale inhibitor for the green circulating cooling water. The efficient corrosion and scale inhibition performance can be guaranteed, meanwhile, the phosphorus content in cooling circulating water is greatly reduced, and breeding of algae in the circulating water is effectively restrained.

Description

Technical Field

[0001] The invention relates to the field of corrosion and scale inhibitors, and in particular to a corrosion and scale inhibitor for green circulating cooling water and a preparation method thereof. Background Art

[0002] Industrial water consumption accounts for a large proportion of the total water consumption in my country, among which circulating cooling water occupies an important position in industrial water. Therefore, it is very important to improve the water resource utilization rate of the circulating water system. However, in the long-term operation of circulating cooling water, problems such as inorganic salt precipitation, corrosion and algae growth will occur, which will corrode the equipment and cause it to be unable to operate normally. Therefore, how to avoid this phenomenon is the key to solving the problem. Literature has reported that several organic solvents have excellent corrosion inhibition effects in all aspects after being mixed, especially under high temperature and concentrated acid, and the corrosion rate is far lower than the first-level standard. Therefore, adding corrosion and scale inhibitors to the circulating water system is an effective way to control corrosion and scale inhibition.

[0003] Nowadays, most factories use phosphorus-based corrosion and scale inhibitors, which are cheap and effective. However, their disadvantage is that they can easily cause eutrophication of water bodies after discharge, and for systems with high concentration multiples, phosphorus-based formulas are more likely to cause bacterial and algae reproduction. Therefore, finding greener new corrosion and scale inhibitors is the future development direction. Summary of the invention

[0004] The purpose of the present invention is to provide a corrosion and scale inhibitor for green circulating cooling water and a preparation method thereof, which has excellent corrosion and scale inhibition effects while greatly reducing the phosphorus content in the cooling circulating water, thereby achieving true green and high efficiency.

[0005] In one aspect of the present invention, the present invention provides a corrosion and scale inhibitor for green circulating cooling water. According to an embodiment of the present invention, the corrosion and scale inhibitor comprises the following components by weight: 3-6 parts of acrylic acid-2-acrylamide-2-methylpropane sulfonic acid copolymer (AA / AMPS), 6-12 parts of hydroxyethylidene diphosphonic acid (HEDPA), 6-15 parts of 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA), 6-12 parts of polyepoxysuccinic acid (PESA), and 6-12 parts of polyaspartic acid (PASP).

[0006] In addition, the green corrosion and scale inhibitor for circulating cooling water according to the above embodiment of the present invention may also have the following additional technical features:

[0007] In some embodiments of the present invention, the preparation method of the acrylic acid-2-acrylamide-2-methylpropane sulfonic acid copolymer comprises the following steps: placing an aqueous monomer solution of acrylic acid (AA) and 2-acrylamide-2-methylpropane sulfonic acid (AMPS) and an aqueous ammonium persulfate solution (initiator) in a constant temperature water bath at 60-70° C. and adding dropwise, heating to 80-90° C. after the addition is completed, and adjusting the pH value of the solution to 8-9 to obtain an acrylic acid-2-acrylamide-2-methylpropane sulfonic acid copolymer (AA / AMPS).

[0008] In some embodiments of the present invention, the ratio of acrylic acid to 2-acrylamide-2-methylpropane sulfonic acid is 50%-70% (mass fraction) of acrylic acid and 30%-50% of 2-acrylamide-2-methylpropane sulfonic acid, and the reaction time of dripping and mixing the monomer aqueous solution of acrylic acid and 2-acrylamide-2-methylpropane sulfonic acid and the aqueous solution of ammonium persulfate initiator is 2-3h.

[0009] In some embodiments of the present invention, the preparation method of hydroxyethylidene diphosphonic acid comprises the following steps: heating the acetic acid aqueous solution to 30-40°C, adding phosphorus trichloride dropwise, and after the addition is completed, raising the temperature to 115-120°C within 2-3 hours, reacting at a constant temperature to evaporate acetyl chloride, and obtaining acetylated HEDP A, i.e. hydroxyethylidene diphosphonic acid.

[0010] In some embodiments of the present invention, the molar ratio of acetic acid to phosphorus trichloride is 3:1, and the constant temperature reaction time is 1-2 hours.

[0011] In some embodiments of the present invention, the preparation method of 2-phosphonobutane-1,2,4-tricarboxylic acid comprises the following steps: adding 10 g of dimethyl phosphite and dimethyl maleate into a reaction kettle, reacting at 100-105° C. for 4-5 hours under the catalysis of sodium peroxide to generate an intermediate, transferring the intermediate into a condensation kettle, reacting the intermediate with acrylic acid in the presence of a catalyst to undergo a Michael addition reaction, and transferring the generated new intermediate into a hydrolysis kettle to undergo hydrolysis under acid catalysis to obtain 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA).

[0012] In some embodiments of the present invention, the preparation method of the polyepoxysuccinic acid comprises the following steps: dissolving maleic anhydride in water, adding sodium hydroxide to react, heating to 55°C, adding hydrogen peroxide and sodium tungstate, adding hydrogen peroxide to maintain the pH value of the reaction system at 5-7, maintaining 1h when the temperature drops to 50-60°C, adding calcium hydroxide, and then heating to 90-100°C, maintaining 2-3h, and obtaining the polyepoxysuccinic acid. The specific steps are as follows: dissolving 22.3g of maleic anhydride (0.227mol) in 32mL of water and cooling in an ice bath. Then adding 29.3g (50% solution, 0.34mol) of sodium hydroxide. The reaction is carried out in a 500mL round-bottom flask. The round bottom flask was placed in an oil bath at 60-70°C. When the temperature reached 55°C, 27g of 30% hydrogen peroxide (0.238mol) and 0.784g (0.0024mol) of sodium tungstate were added. 9.1g (50%, 100°C) of hydrogen peroxide was added to maintain the pH value of the reaction system at 5-7. When heated to 60°C and maintained for 1h, 0.84g (0.0114mol) of calcium hydroxide was added, and then heated to 100°C and maintained for 2-3h. Volatiles were removed under vacuum, and the product was dried under vacuum at 100°C.

[0013] In another aspect of the present invention, the present invention proposes a method for preparing the green circulating cooling water corrosion inhibitor. According to an embodiment of the present invention, the method comprises the following steps: adding acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, hydroxyethylidene diphosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, polyepoxysuccinic acid, polyaspartic acid and water into a stirrer, stirring at room temperature for 10 minutes, and obtaining the green circulating cooling water corrosion inhibitor after the stirring.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1) The addition of polyepoxysuccinic acid (PESA) and polyaspartic acid (PASP) can significantly reduce the phosphorus content in the cooling circulating water, effectively curbing the growth of algae in the circulating water, while directly discharging it will not pollute the environment.

[0016] 2) The present invention obtains an excellent corrosion and scale inhibitor by adding three organic substances, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, hydroxyethylidene diphosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, polyepoxysuccinic acid (PESA), polyaspartic acid (PASP) and water into a stirrer. Several organic substances can reduce the contact between corrosion factors and metals, thereby reducing the corrosion inhibition rate, and together constitute a corrosion inhibition system. At the same time, because the molecular structure contains carboxylic acid groups with good scale inhibition and dispersion performance and strong polar sulfonic acid groups, it can improve calcium tolerance, has a significant scale inhibition effect on calcium phosphate, calcium carbonate, zinc scale and the like in water, and has excellent dispersibility.

[0017] 3) The corrosion and scale inhibitor of the present invention has extremely excellent corrosion inhibition ability and can greatly reduce the corrosion rate of circulating water on carbon steel pipelines. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Example 1

[0020] A method for preparing a corrosion and scale inhibitor for green circulating cooling water comprises the following steps:

[0021] (1) Place a reaction bottle equipped with a stirrer and a thermometer in a constant temperature water bath, and add 30 g of water to the reaction bottle. Dissolve 38 g of AA and 18 g of AMPS in 60 g of water for later use; dissolve 4.6 g of ammonium persulfate in 60 g of water for later use; at 60°C, drop the monomer aqueous solution of acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid and the ammonium persulfate aqueous initiator solution into the reaction bottle, respectively. After the dropwise addition is completed, heat the bottle to 90°C, and adjust the pH value of the solution to 9 with sodium hydroxide to obtain an AA / AMPS copolymer.

[0022] (2) Add 270 g of acetic acid and 72 g of water to a reaction flask to prepare an acetic acid aqueous solution, stir, heat to 40° C., dropwise add 165 g of phosphorus trichloride, and after the addition is complete, slowly raise the temperature to 120° C. within 3 hours. After a period of constant temperature reaction, evaporate acetyl chloride to obtain acetylated HEDP A.

[0023] (3) 10 g of dimethyl phosphite and dimethyl maleate were added to a reaction kettle, and reacted at 105°C for 4 h under the catalysis of sodium peroxide to generate an intermediate. The intermediate was transferred to a condensation kettle, and the new intermediate generated by the Michael addition reaction with acrylic acid in the presence of a catalyst was transferred to a hydrolysis kettle and hydrolyzed under acid catalysis to obtain PBTCA.

[0024] (4) 22.3 g of maleic anhydride was dissolved in 32 g of water, and then 29.3 g of sodium hydroxide was added to react in a 500 mL round-bottom flask equipped with a magnetic stirrer, a pH meter, a thermometer and a funnel. After heating to 55°C, 27 g of hydrogen peroxide and 0.784 g of sodium tungstate were added, and 9.1 g of hydrogen peroxide was added to maintain the pH value of the reaction system at 7. The temperature dropped to 60°C and maintained for 1 hour, 0.84 g of calcium hydroxide was added, and then heated to 100°C and maintained for 2 hours to obtain PESA.

[0025] (5) 6 parts by weight of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer (AA / AMPS), 6 parts by weight of hydroxyethylidene diphosphonic acid (HEDPA), 12 parts by weight of 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA), 12 parts by weight of polyepoxysuccinic acid (PESA), 12 parts by weight of polyaspartic acid (PASP) and 100 parts by weight of water are added into a stirrer and stirred at room temperature for 10 minutes. After stirring, a new green and efficient corrosion and scale inhibitor for circulating cooling water is obtained.

[0026] Example 2

[0027] A method for preparing a corrosion and scale inhibitor for green circulating cooling water comprises the following steps:

[0028] (1) Place a reaction bottle equipped with a stirrer and a thermometer in a constant temperature water bath, and add 30 g of water to the reaction bottle. Dissolve 38 g of AA and 18 g of AMPS in 60 g of water for later use; dissolve 4.6 g of ammonium persulfate in 60 g of water for later use; at 60°C, drop the monomer aqueous solution of acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid and the ammonium persulfate aqueous initiator solution into the reaction bottle, respectively. After the dropwise addition is completed, heat the bottle to 90°C, and adjust the pH value of the solution to 9 with sodium hydroxide to obtain an AA / AMPS copolymer.

[0029] (2) Add 270 g of acetic acid and 72 g of water to a reaction flask to prepare an acetic acid aqueous solution, stir, heat to 40° C., dropwise add 165 g of phosphorus trichloride, and after the addition is complete, slowly raise the temperature to 120° C. within 3 hours. After a period of constant temperature reaction, evaporate acetyl chloride to obtain acetylated HEDP A.

[0030] (3) 10 g of dimethyl phosphite and dimethyl maleate were added to a reaction kettle, and reacted at 105°C for 4 h under the catalysis of sodium peroxide to generate an intermediate. The intermediate was transferred to a condensation kettle, and the new intermediate generated by the Michael addition reaction with acrylic acid in the presence of a catalyst was transferred to a hydrolysis kettle and hydrolyzed under acid catalysis to obtain PBTCA.

[0031] (4) 22.3 g of maleic anhydride was dissolved in 32 g of water. Then 29.3 g of sodium hydroxide was added and reacted in a 500 mL round-bottom flask equipped with a magnetic stirrer, a pH meter, a thermometer and a funnel. After heating to 55°C, 27 g of hydrogen peroxide and 0.784 g of sodium tungstate were added, and 9.1 g of hydrogen peroxide was added to maintain the pH value of the reaction system at 7. When the temperature dropped to 60°C and maintained for 1 h, 0.84 g of calcium hydroxide was added, and then heated to 100°C and maintained for 2 h to obtain PESA.

[0032] (5) 6 parts by weight of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer (AA / AMPS), 6 parts by weight of hydroxyethylidene diphosphonic acid (HEDPA), 12 parts by weight of 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA), 6 parts by weight of polyepoxysuccinic acid (PESA), 6 parts by weight of polyaspartic acid (PASP) and 100 parts by weight of water are added into a stirrer and stirred at room temperature for 10 minutes. After stirring, a new green and efficient corrosion and scale inhibitor for circulating cooling water is obtained.

[0033] Example 3

[0034] A method for preparing a corrosion and scale inhibitor for green circulating cooling water comprises the following steps:

[0035] (1) Place a reaction bottle equipped with a stirrer and a thermometer in a constant temperature water bath, and add 30 g of water to the reaction bottle. Dissolve 38 g of AA and 18 g of AMPS in 60 g of water for later use; dissolve 4.6 g of ammonium persulfate in 60 g of water for later use; at 60°C, drop the monomer aqueous solution of acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid and the ammonium persulfate aqueous initiator solution into the reaction bottle, respectively. After the dropwise addition is completed, heat the bottle to 90°C, and adjust the pH value of the solution to 9 with sodium hydroxide to obtain an AA / AMPS copolymer.

[0036] (2) Add 270 g of acetic acid and 72 g of water to a reaction flask to prepare an acetic acid aqueous solution, stir, heat to 40° C., dropwise add 165 g of phosphorus trichloride, and after the addition is complete, slowly raise the temperature to 120° C. within 3 hours. After a period of constant temperature reaction, evaporate acetyl chloride to obtain acetylated HEDP A.

[0037] (3) 10 g of dimethyl phosphite and dimethyl maleate were added to a reaction kettle, and reacted at 105°C for 4 h under the catalysis of sodium peroxide to generate an intermediate. The intermediate was transferred to a condensation kettle, and the new intermediate generated by the Michael addition reaction with acrylic acid in the presence of a catalyst was transferred to a hydrolysis kettle and hydrolyzed under acid catalysis to obtain PBTCA.

[0038] (4) 22.3 g of maleic anhydride was dissolved in 32 g of water. Then 29.3 g of sodium hydroxide was added and reacted in a 500 mL round-bottom flask equipped with a magnetic stirrer, a pH meter, a thermometer and a funnel. After heating to 55°C, 27 g of hydrogen peroxide and 0.784 g of sodium tungstate were added, and 9.1 g of hydrogen peroxide was added to maintain the pH value of the reaction system at 7. When the temperature dropped to 60°C and maintained for 1 h, 0.84 g of calcium hydroxide was added, and then heated to 100°C and maintained for 2 h to obtain PESA.

[0039] (5) 6 parts by weight of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer (AA / AMPS), 6 parts by weight of hydroxyethylidene diphosphonic acid (HEDPA), 12 parts by weight of 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA), 8 parts by weight of polyepoxysuccinic acid (PESA), 8 parts by weight of polyaspartic acid (PASP) and 100 parts by weight of water are added into a stirrer and stirred at room temperature for 10 minutes. After stirring, a new green and efficient corrosion and scale inhibitor for circulating cooling water is obtained.

[0040] According to the National Standard of the People's Republic of China GB / T18175-2000, Determination of Corrosion Inhibition Performance of Water Treatment Agents - Rotating Coupon Method and GB / T 16632-2019 "Determination of Scale Inhibition Performance of Water Treatment Agents - Calcium Carbonate Deposition Method", the corrosion and scale inhibition performance of Examples 1-3 was tested. The results are shown in the following table:

[0041] Table 1 Corrosion and scale inhibition performance of the corrosion and scale inhibitor for circulating cooling water of Examples 1-3

[0042]

[0043] It can be seen from Table 1 that Examples 1-3 of the present invention have good corrosion and scale inhibition effects.

[0044] According to the National Standard of the People's Republic of China GB / T11893-1989, the ammonium molybdate spectrophotometry method was used to test the phosphorus content of Examples 1-3. The results are shown in the following table:

[0045] Table 2 Phosphorus content of corrosion and scale inhibitors for circulating cooling water in Examples 1-3 (in terms of PO4 3- count)

[0046]

[0047] The above experiments all show that the new green corrosion and scale inhibitor formula can still help reduce the phosphorus content in water without affecting performance, which helps prevent eutrophication of water bodies, protect water resources, and reduce harm to the ecological environment.

[0048] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A corrosion and scale inhibitor for green circulating cooling water, characterized in that: The invention comprises the following components in parts by weight: 3-6 parts of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 6-12 parts of hydroxyethylidene diphosphonic acid, 6-15 parts of 2-phosphonobutane-1,2,4-tricarboxylic acid, 6-12 parts of polyepoxysuccinic acid and 6-12 parts of polyaspartic acid.

2. A corrosion and scale inhibitor for green circulating cooling water according to claim 1, characterized in that: The preparation method of the acrylic acid-2-acrylamide-2-methylpropane sulfonic acid copolymer comprises the following steps: placing an aqueous solution of acrylic acid and 2-acrylamide-2-methylpropane sulfonic acid monomers and an aqueous solution of ammonium persulfate in a 60-70° C. constant temperature water bath and adding dropwise, heating the solution to 80-90° C. after the dropwise addition is completed, and adjusting the pH value of the solution to 8-9 to obtain the acrylic acid-2-acrylamide-2-methylpropane sulfonic acid copolymer.

3. The corrosion and scale inhibitor for green circulating cooling water according to claim 2, characterized in that: The mass percentage of the acrylic acid is 50%-70%, the amount percentage of the 2-acrylamide-2-methylpropane sulfonic acid is 30%-50%, the monomer aqueous solutions of the acrylic acid and 2-acrylamide-2-methylpropane sulfonic acid and the aqueous solution of ammonium persulfate are mixed and added dropwise, and the reaction time is 2-3 hours.

4. A corrosion and scale inhibitor for green circulating cooling water according to claim 1, characterized in that: The preparation method of hydroxyethylidene diphosphonic acid comprises the following steps: heating an acetic acid aqueous solution to 30-40° C., adding phosphorus trichloride dropwise, raising the temperature to 115-120° C. within 2-3 hours after the addition is completed, reacting at a constant temperature to evaporate acetyl chloride, and obtaining hydroxyethylidene diphosphonic acid.

5. The green corrosion and scale inhibitor for circulating cooling water according to claim 4, characterized in that: The molar ratio of acetic acid to phosphorus trichloride is 3:1, and the constant temperature reaction time is 1-2 hours.

6. The corrosion and scale inhibitor for green circulating cooling water according to claim 1, characterized in that: The preparation method of 2-phosphonobutane-1,2,4-tricarboxylic acid comprises the following steps: adding 10g of dimethyl phosphite and dimethyl maleate into a reaction kettle, reacting at 100-105°C for 4-5h under the catalysis of sodium peroxide to generate an intermediate, transferring the intermediate into a condensation kettle, reacting the intermediate with acrylic acid in the presence of a catalyst to generate a Michael addition reaction, and transferring the generated new intermediate into a hydrolysis kettle to hydrolyze under acid catalysis to obtain 2-phosphonobutane-1,2,4-tricarboxylic acid.

7. The green corrosion and scale inhibitor for circulating cooling water according to claim 1, characterized in that: The preparation method of polyepoxysuccinic acid comprises the following steps: dissolving maleic anhydride in water, adding sodium hydroxide for reaction, heating to 55°C, adding hydrogen peroxide and sodium tungstate, adding hydrogen peroxide to maintain the pH value of the reaction system at 5-7, maintaining the temperature at 50-60°C for 1h, adding calcium hydroxide, and then heating to 90-100°C for 2-3h to obtain the polyepoxysuccinic acid.

8. A method for preparing the corrosion and scale inhibitor for green circulating cooling water according to any one of claims 1 to 7, characterized in that: The following steps are involved: Add acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, hydroxyethylidene diphosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, polyepoxysuccinic acid, polyaspartic acid and water into a stirrer and stir for 10 minutes at room temperature. After stirring, the green circulating cooling water corrosion and scale inhibitor is obtained.

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