KR20020056454A - Composition for prevented rust and scale - Google Patents

Abstract

PURPOSE: Provided is an anti-rust/anti-scale agent suitable for use in low pressure boiler(less than 35 kg) into which a cooling water with calcium ion concentration of higher than 1 ppm is introduced. CONSTITUTION: The anti-rust/anti-scale agent comprises 0.1 to 25 wt.% of acrylate copolymer, represented by formula I; organic phosphate 0.1 to 20 wt.%; sodium gluconate 0.1 to 20 wt.%; sodium sulfite 0.1 to 25 wt.%; amine compound 0.1 to 10 wt.%. In the formula I, each l, m and n are an integer of 1 to 1000 respectively; R denote hydrogen, methyl or carboxyl, wherein in case that R is carboxyl group, R react with adjacent carboxyl group to form anhydrous ring; R1 and R8 are identical or different each other and denote hydrogen, alkyl, hydroxy or phosphono group; R2 and R3 are identical or different each other and denote hydrogen or C1-C2 alkyl group; R4 denote hydrogen or C1-C5 alkyl group; R5 denote C1-C8 alkyl or C8-C10 alkyl group; X and Y are identical or different each other and denote C1-C5 alkyl or C1-C5 hydroxy alkyl group; R0 is represented by formula II, III or IV. In the formula III, R6 is hydrogen or C1-C2 alkyl group; R7 is C1-C6 alkyl, C6-C10 alkyl or compound represented by formula V. In the formula V, I is an integer of 1 to 3; R9 denote hydrogen C1-C2 alkyl; R10 denote hydrogen or C1-C6 alkyl group. In the formula IV, R12 denote hydrogen or C1-C2 alkyl; R13 and R14 are identical or different each other and denote hydrogen, C1-C8 alkyl, C6-C8 cyclo alkyl, benzyl or a compound represented by formula V.

Description

Corrosion and Scale Prevention Compositions {COMPOSITION FOR PREVENTED RUST AND SCALE}

[Industrial use]

The present invention relates to a composition for preventing corrosion and scale, and is particularly useful for low-pressure boiler water systems of 35 kg or less in which water quality of raw water is not very good even if the water softener is not installed or installed, so that more than 1 ppm of calcium ions are introduced into the feed water. It relates to a composition for preventing corrosion and scale.

[Prior art]

In various industrial facilities where boiler water is needed and in buildings that use boiler water for heating, corrosion and scale are intensively generated on metal surfaces, especially heat transfer surfaces, where the boiler water system is in contact with water. At the same time, the thermal efficiency can be reduced and, in severe cases, can lead to a severe situation in which the water pipe ruptures.

Corrosion can be described simply as rust in metal materials. In general, since metal is a material made from an oxide state through a refining process, it has a very strong property of returning to a thermodynamically stable oxide state. It is therefore natural that corrosion occurs in boiler systems.

The scale phenomenon is mainly due to the hardness component introduced into the boiler feed water together with the anion, and the hardness component mainly means calcium and magnesium ions. The inflow of hardness components can be seen as two cases where raw water is used as boiler feed water without a water softener, and the cation is not completely removed despite the water softener.

The scale components produced by the inflow of hardness components are the highest in calcium carbonate and calcium phosphite, and they are concentrated on relatively high heat transfer surfaces because they have physical properties that are less soluble as the temperature increases. It causes some problems.

Conventionally, sedimentation type and non-precipitating type were used as a water treatment agent program to prevent the scale of such a low pressure boiler. The precipitation type includes a carbonate program and a phosphate program, and a non-precipitating type chelate program is known (Chemical Engineering / August 15). , 1988).

Among the above programs, the carbonate program has been used for a long time to prevent calcium sulfate scale formation in boilers with a pressure of 150 psig or less and water hardness of about 50 ppm, but at a boiler pressure of 50 psig or higher, sodium carbonate and sodium hydroxide It decomposes into carbon dioxide and loses its scale control ability, and the decomposed carbon dioxide dissolves in the condensate and adversely affects the corrosion of the condensate line.

Chelating programs are effective at pressures up to 1300 psig, where the calcium hardness of the feedwater is less than 1.5 ppm, but is very difficult to apply because of the high corrosive properties of chelating compounds. For example, if the maintenance concentration of the chelate is low, there is no threshold function, so the scale control ability is lost, and if the concentration of the chelate is high, corrosion by the chelate occurs.

The phosphate program is currently the most widely used boiler water treatment program. It is used together with polymers to remove suspended solids with calcium phosphate. However, in the water quality of 50 ppm or more of concentrated calcium hardness in watering, there is a problem that the performance of the program is rapidly lowered, but rather adversely affects the weight of calcium phosphate scale.

In view of the problems of the prior art, it is an object of the present invention to provide a composition for preventing corrosion and scale excellent in anticorrosive effect and excellent ability to suppress scale.

In another aspect, the present invention provides a boiler water treatment method excellent in suppressing the scale.

[Means for solving the problem]

The present invention, in order to achieve the above object, in the composition for preventing corrosion and scale,

Iii) an acrylate polymer;

Ii) organophosphoric acid;

Iii) sodium gluconate;

Viii) sodium sulfite; And

Iii) amine compounds

It provides a composition for preventing corrosion and scale comprising a.

Also in the water treatment method of the boiler,

V) 0.1-25 wt% of the acrylate polymer;

Ii) 0.1 to 20% by weight of organophosphoric acid;

V) 0.1-20% by weight sodium gluconate;

V) 0.1-25 wt% sodium sulfite; And

Iii) 0.1 to 10% by weight of amine compound

Corrosion and scale preventing composition comprising 1 to 200,000 ppm

It provides a water treatment method comprising the step of putting in the water system of the closed system.

Hereinafter, the present invention will be described in detail.

[Action]

The present invention relates to a composition for preventing corrosion and scale, wherein the water quality of raw water is poor even if the water softener is not provided or contains an acrylate polymer, organophosphoric acid, sodium gluconate, sodium sulfite, and an amine compound. In the low pressure boiler water of 35 kg or less in which calcium ions of 1 ppm or more are introduced into the feed water, it is possible to provide a composition for preventing corrosion and scaling having an excellent corrosion and scale preventing function and at the same time having a corrosion preventing function of a condensation line.

More specifically,

V) 0.1-25 wt% of the acrylate polymer;

Ii) 0.1 to 20% by weight of organophosphoric acid;

V) 0.1-20% by weight sodium gluconate;

V) 0.1-25 wt% sodium sulfite; And

Iii) 0.1 to 10% by weight of amine compound

It is a composition for preventing corrosion and scale.

It is preferable that the acrylate-type polymer of (i) is a compound represented by the structure of following General formula (1).

[Formula 1]

In the formula of Formula 1,

Each of l, m and n is an integer of 1 to 1000,

R is hydrogen, methyl, or a carboxyl group, and when R is a carboxyl group, R may combine with an adjacent carboxyl group to form an anhydrous ring,

Each of R ₁ and R ₈ is the same or different hydrogen, an alkyl group, a hydroxy group, or a phosphono group,

Each of R ₂ and R ₃ is the same or different hydrogen or an alkyl group having 1 to 2 carbon atoms,

R ₄ is hydrogen or an alkyl group having 1 to 5 carbon atoms,

R ₅ is an alkyl group having 1 to 8 carbon atoms or an alkyl group having 8 to 10 carbon atoms;

Each X and Y is the same or different hydrogen, an alkyl group of 1 to 5 carbon atoms, or a hydroxy alkyl group of 1 to 5 carbon atoms,

R ₀ is a compound represented by the structure of Formula 2, 3, or 4 below;

[Formula 2]

[Formula 3]

In the formula (3),

R ₆ is hydrogen or an alkyl group having 1 to 2 carbon atoms,

R ₇ is a compound represented by an alkyl group having 1 to 6 carbon atoms, an alkyl group having 6 to 10 carbon atoms, or a structure represented by the following formula (5);

[Formula 5]

In the formula (5),

i is 1, 2, or 3,

R ₉ is hydrogen or an alkyl group having 1 to 2 carbon atoms,

R ₁₀ is hydrogen or an alkyl group having 1 to 6 carbon atoms;

[Formula 4]

In the formula (4),

R ₁₂ is hydrogen or an alkyl group having 1 to 2 carbon atoms,

Each of R ₁₃ and R ₁₄ is the same as or different from each other hydrogen, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 6 to 8 carbon atoms, a benzyl group, or a compound represented by the formula (5).

The acrylate polymer of iii) uses 0.1 to 25% by weight, and it is preferable to maintain 1 to 500 ppm in the boiler water when the water treatment program is applied. When the amount of the acrylate-based polymer is less than 0.1% by weight, the effect is insignificant, and when the amount of the acrylate-based polymer exceeds 25% by weight, product stability is a problem.

The organic phosphoric acid of ii) is used in 0.1 to 20% by weight, it is preferable to maintain 1 to 400 ppm in the boiler water. When the amount of the organic phosphoric acid is less than 0.1% by weight, the effect is insignificant, and when the amount of the organophosphoric acid is more than 20% by weight, there is a problem in economy.

In addition, the organic phosphoric acid of ii) is hydroxyethylidenediphosphonic acid, diethylenetriaminepentamethylene phosphonic acid, hexamethylenediaminetetraethylphosphonic acid, nitrilotrimethylene phosphonic acid, and ethylenediamine tetramethylenedipo It is preferable that 1 or more types are chosen from the group which consists of a sponic acid.

Sodium gluconate of i) is used in an amount of 0.1 to 20% by weight, and it is preferable to maintain 1 to 400 ppm in boiler water. If the amount of sodium gluconate is less than 0.1% by weight, the effect is insignificant, and if it exceeds 20% by weight, there is a problem in economic efficiency.

Sodium sulfite of iii) is used in 0.1 to 25% by weight, it is preferable to maintain 50 ppb to 50 ppm in the boiler feed water. When the amount of the sodium sulfite is less than 0.1% by weight, the oxygen removal effect is insignificant, and when it exceeds 25% by weight, product stability is a problem.

When the amine compound of iii) is used in an amount of 0.1 to 10% by weight, it is preferable to maintain 0.1 to 200 ppm in boiler condensate, and when the amount is less than 0.1% by weight, the effect is insufficient when used, and when it exceeds 10% by weight. There is a problem with economics. As an example, it is preferable that 1 or more types are chosen from the group which consists of morpholine, cyclohexylamine, diethylethanolamine, and dimethylpropanolamine.

In addition, the boiler water treatment method

V) 0.1-25 wt% of the acrylate polymer;

Ii) 0.1 to 20% by weight of organophosphoric acid;

V) 0.1-20% by weight sodium gluconate;

V) 0.1-25 wt% sodium sulfite; And

Iii) 0.1 to 10% by weight of amine compound

Corrosion and scale preventing composition comprising 1 to 200,000 ppm

It provides a water treatment method comprising the step of putting in the water system of the closed system.

Corrosion and anti-scale composition of the present invention is effective in the corrosion and scale prevention and corrosion prevention of the condensation line in a boiler having a steam pressure of 35 kg or less, the calcium hardness of the boiler feed water of 1 ppm or more.

The present invention will be described in more detail with reference to the following examples and comparative examples. However, an Example is for illustrating this invention and is not limited only to these.

EXAMPLE

Example 1

20 ppm of chlorite k776 from Goodrich, an acrylate polymer, 20 ppm of quest 2066 from Monsanto, ethylenediaminetetramethyllidinephosphonic acid, 50 ppm of sodium gluconate, 5 ppm of sodium sulfide, and an amine compound 10 ppm of morpholine was mixed to maintain the test solution, thereby preparing a composition for preventing corrosion and scale.

Example 2

40 ppm of chlorite k776, an acrylate-based polymer, and organophosphoric acid include 40 ppm of quest 2066, 40 ppm of sodium gluconate, 10 ppm of sodium sulfide, and an amine compound of ethylenediaminetetramethyllidine phosphonic acid. 20 ppm of morpholine was mixed to maintain the test solution, thereby preparing a composition for preventing corrosion and scale.

Example 3

80 ppm of chlorite k776, an acrylate-based polymer, and organophosphoric acid include 80 ppm of quest 2066, ethylenediaminetetramethyllidine phosphonic acid, 20 ppm of sodium gluconate, 20 ppm of sodium sulfide, and an amine compound. 40 ppm of morpholine was mixed to maintain the test solution to prepare a composition for preventing corrosion and scale.

Comparative Example 1

The experiment was carried out without addition of the composition for corrosion and scale prevention.

Comparative Example 2

Only 5 ppm of Goodlite k776 from Goodrich, an acrylate-based polymer, was used to prepare a composition for preventing corrosion and scale.

Comparative Example 3

As organophosphoric acid, 5 ppm of Dequest 2066, and 5 ppm of sodium sulfide, which is an ethylenediaminetetramethyllidinephosphonic acid, and sodium sulfide were mixed to prepare a composition for preventing corrosion and scale.

Experimental Example

Experimental Example 1

Corrosion Experiment

Corrosion experiments of water treatment agent compositions for boilers prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were measured using an autoclave. The weight loss of the low carbon steel having a carbon content of 0.18% was measured by immersing the composition for preventing corrosion and scale at a temperature of 121 ° C. and a pressure of 1.5 kg for 30 minutes in the experimental water of A, B, and C as follows. It is shown in Table 1 below.

The pHs of the following experimental water quality A, B, and C were adjusted with 0.1 N, 0.5 N, and 1 N aqueous sodium hydroxide solution, the calcium hardness was calculated as calcium chloride, and the total hardness was calculated as the amount of magnesium hardness that adhered to the calcium hardness. It was adjusted with magnesium sulfate, respectively.

Experimental water quality A: pH 10.0 ± 0.5, calcium hardness 50 ppm, total hardness 60 ppm, chlorine ion 35.5 ppm

Experimental water quality B: pH 10.0 ± 0.5, calcium hardness 100 ppm, total hardness 120 ppm, chlorine ion 71 ppm

Experimental water C: pH 10.0 ± 0.5, calcium hardness 200 ppm, total hardness 240 ppm, chlorine ion 142 ppm

TABLE 1

division Weight loss (mg) Experimental Water Quality A Experimental Water Quality B Experimental Water Quality C Example 1 1.8 1.7 1.0 Example 2 0.9 0.8 0.4 Example 3 0.4 0.3 0.2 Comparative Example 1 7.1 6.9 6.8 Comparative Example 2 7.0 6.9 6.8 Comparative Example 3 5.6 5.6 5.3

Through Table 1, compared to Comparative Examples 1 to 3 in the case of preparing the composition for preventing corrosion and scale by adding an acrylate-based polymer, organophosphoric acid, sodium gluconate, sodium sulfite, and morpholine Not only was the anti-corrosion effect excellent, it was confirmed that the composition is stable even in a mixed state.

Experimental Example 2

(Scale Formation Inhibition Experiment)

In order to evaluate the scale inhibition ability of the boiler, experiments with calcium hardness 500 ppm, M-alkaline 500 ppm and 355 ppm chlorine ion (the calcium hardness was adjusted with calcium chloride and M-alkaline with sodium bicarbonate and sodium carbonate) 200 mL of water was placed in a capped bottle, and the corrosion and scale preventing compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were added thereto. After adjusting the pH of the solution to 9.15, scale inhibition experiments were conducted in an oven for 20 hours. After 20 hours, the mixture was cooled to room temperature, filtered using a 0.45 μm filter, and then the calcium hardness was measured. The calcium transport value was calculated and shown in Table 2 below.

The calcium transformation value is a measure of how many percent is removed by blowdown when the hardness components of the feedwater are concentrated in the boiler irrigation. 80% means that it is attached to the surface of the boiler on a scale.

TABLE 2

division Calcium Transformation Value (%) Example 1 83 Example 2 88 Example 3 92 Comparative Example 1 33 Comparative Example 2 68 Comparative Example 3 64

Through Table 2, compared with Comparative Examples 1 to 3 in the case of Examples 1 to 3 to prepare a composition for preventing corrosion and scale by adding an acrylate-based polymer, organophosphoric acid, sodium gluconate, sodium sulfite, and morpholine It was confirmed that the scale inhibition rate is excellent.

The present invention can provide a corrosion and scale prevention composition having a corrosion protection function of the condensation line while showing an excellent corrosion and scale prevention function in a low pressure boiler water of 35 kg or less.

Claims (7)

In the composition for preventing corrosion and scale, Iii) an acrylate polymer; Ii) organophosphoric acid; Iii) sodium gluconate; Viii) sodium sulfite; And Iii) amine compounds Corrosion and anti-scale composition comprising a. The method of claim 1, V) 0.1-25 wt% of the acrylate polymer; Ii) 0.1 to 20% by weight of organophosphoric acid; V) 0.1-20% by weight sodium gluconate; V) 0.1-25 wt% sodium sulfite; And Iii) 0.1 to 10% by weight of amine compound Corrosion and anti-scale composition comprising a. The method according to any one of claims 1 to 2, The acrylate-based polymer of iii) is a compound represented by the structure of Formula 1 below: [Formula 1] In the formula of Formula 1, Each of l, m and n is an integer of 1 to 1000, R is hydrogen, methyl, or a carboxyl group, and when R is a carboxyl group, R may combine with an adjacent carboxyl group to form an anhydrous ring, Each of R ₁ and R ₈ is the same or different hydrogen, an alkyl group, a hydroxy group, or a phosphono group, Each of R ₂ and R ₃ is the same or different hydrogen or an alkyl group having 1 to 2 carbon atoms, R ₄ is hydrogen or an alkyl group having 1 to 5 carbon atoms, R ₅ is an alkyl group having 1 to 8 carbon atoms or an alkyl group having 8 to 10 carbon atoms; Each X and Y is the same or different hydrogen, an alkyl group of 1 to 5 carbon atoms, or a hydroxy alkyl group of 1 to 5 carbon atoms, R ₀ is a compound represented by the structure of Formula 2, 3, or 4 below; [Formula 2] [Formula 3] In the formula (3), R ₆ is hydrogen or an alkyl group having 1 to 2 carbon atoms, R ₇ is a compound represented by an alkyl group having 1 to 6 carbon atoms, an alkyl group having 6 to 10 carbon atoms, or a structure represented by the following formula (5); [Formula 5] In the formula (5), i is 1, 2, or 3, R ₉ is hydrogen or an alkyl group having 1 to 2 carbon atoms, R ₁₀ is hydrogen or an alkyl group having 1 to 6 carbon atoms; [Formula 4] In the formula (4), R ₁₂ is hydrogen or an alkyl group having 1 to 2 carbon atoms, Each of R ₁₃ and R ₁₄ is the same as or different from each other hydrogen, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 6 to 8 carbon atoms, a benzyl group, or a compound represented by the formula (5). The method according to any one of claims 1 to 2, The organic phosphate of ii) is hydroxyethylidenediphosphonic acid, diethylenetriaminepentamethylene phosphonic acid, hexamethylenediamine tetraethylphosphonic acid, nitrilotrimethylene phosphonic acid, and ethylenediamine tetramethylene diphospho A composition for preventing corrosion and scale, which is selected from the group consisting of nickexide. The method according to any one of claims 1 to 2, A composition for preventing corrosion and scale, wherein the amine compound of vi) is selected from the group consisting of morpholine, cyclohexylamine, diethylethanolamine, and dimethylpropanolamine. In the water treatment method of the boiler, V) 0.1-25 wt% of the acrylate polymer; Ii) 0.1 to 20% by weight of organophosphoric acid; V) 0.1-20% by weight sodium gluconate; V) 0.1-25 wt% sodium sulfite; And Iii) 0.1 to 10% by weight of amine compound Corrosion and scale preventing composition comprising 1 to 200,000 ppm To a water system of the closed system. The method of claim 6, The boiler has a steam pressure of 35 kg or less, and the calcium hardness of the boiler feed water is 1 ppm or more.