WO2007080811A1

WO2007080811A1 - Antiscaling agent and antiscaling method

Info

Publication number: WO2007080811A1
Application number: PCT/JP2006/326328
Authority: WO
Inventors: Hirotaka Ogasahara
Original assignee: Kurita Water Industries Ltd.
Priority date: 2006-01-11
Filing date: 2006-12-25
Publication date: 2007-07-19
Also published as: JP2011236547A; JPWO2007080811A1; CN101356122B; JP5353960B2; CN101356122A

Abstract

A method for inhibiting scale build-up in aqueous systems under the conditions of 50 to 250°C and pH>9, characterized by adding a carboxyl-bearing polymer or a salt thereof and a phosphono-bearing compound or a salt thereof to the aqueous systems; and an antiscaling agent for inhibiting scale build-up in aqueous systems under the conditions of 50 to 250°C and pH>9, characterized by comprising a carboxyl-bearing polymer or a salt thereof and a phosphono-bearing compound or a salt thereof. The antiscaling agent of the invention can effectively inhibit scale build-up even when the quantity thereof added is small, and is effective in inhibiting scale build-up in boiler tubes, dust collection water systems in steel making converters, digesters and black liquor concentration step in pulp production , and so on.

Description

Description Prevention of scale and simultaneous suction scale

The present invention relates to a scale prevention method and a scale prevention agent. More specifically, the present invention is applied to an aqueous system under high temperature (50 ° C. or higher and 25 ° C. or lower) and high strength (pH 9)! The scale can be effectively prevented with a small amount of added calorie additive,

The present invention relates to a scale prevention method and a skeno deterrent that are suitable for scaling in the cooking process in the production process. Background

A scale is a substance in which a substance dissolved or suspended in water is precipitated or solidified on a solid surface. The type of the slurry varies depending on the aqueous system, and includes calcium carbonate, calcium sulfate, calcium sulfite, calcium phosphate, calcium silicate, magnesium silicate, magnesium hydroxide, phosphate, 7-oxidizer, and oxalate. The scale adheres to ^, piping, dredging, etc. in many devices such as boilers, cooling water «, garbage incinerators,» ms «, seawater devices, etc. Causes various jurisdictions such as breakage, increased pump pressure, decreased flow, decreased production, interrupted operation, and wasted energy. Under high temperature and high alkali conditions, scale is generated, and scale removal is not easy. For this reason, it is desired to prevent adhesion of the scale continuously without stopping the operation, and various methods for stopping the Skeno H3 are used. For example, in the kraft pulp manufacturing process, as a method of preventing scale adhesion that effectively prevents the scaling phenomenon generated inside the digester, polymaleic acid or a salt thereof is added to the white liquor in the digester or in the evening. There is a proposed method (Patent Document 1). In addition, as a method of continuously preventing skeinole adhering to the kraft tanks and the surrounding piping and equipment in the cooking process, acrylo-itaconic acid copolymerization can be added to the cooking liquor in the digester. The method of adding calories to the salt has been tested (Patent Document 2). Similarly, as a scale adhesion inhibitor that continuously prevents scale from adhering to the cooking and cooking equipment in the kraft pallet and its surroundings, as a scale adhesion inhibitor, 1-acrylo maleate — 2-acrylamido 2— Methylpropanesulfo A scale adhesion inhibitor containing an acid terpolymer has been proposed (Patent Document 3). Furthermore, as a method for improving the structure of the calcium salt scale in the chemical pulping process, there has been proposed a method in which phosphon derivative is added to the digester (Patent Document 4).

However, these methods require a large amount of chemicals in order to obtain a sufficient scale prevention effect. Under these circumstances, a more effective scale prevention method is desired. In addition, because the target of scaling / restraint treatment is high azore power, adding phosphonic acid to the bacteria may cause a neutral heat and is dangerous. In order to avoid this, it is possible to use a neutralized preparation that is obtained by neutralizing phosphonic acid to form a salt. However, the neutralized preparation has a problem of high cost. Furthermore, when scale prevention is performed only with a polymer having a carboxyl group, there is a problem that a high concentration of chemical power S is required.

[Patent Document 1] Hei 2-5 3 5 5 1

[Patent Document 2] Japanese Patent Laid-Open No. 4-1 3 6 2 8 6

[Patent Document 3] Japanese Patent No. 3 1 9 4 8 6 7

[Patent Document 4] Table 2 0 0 4— 5 3 2 9 4 5 Disclosure of Invention

The present invention effectively prevents scale in a water system under high temperature (50 ° C. or higher and 25 ° C. or lower) and high strength (pH 9) conditions with a small amount of addition of a laxative agent. In the boiler can,, converter system, PAL: ^ The purpose of the scale prevention method and scale inhibitor is to prevent scale in the cooking process of the cooking process. The

As a result of intensive efforts to solve the above problems, the inventor of the present invention uses a polymer having a strong levoxinore group or a salt thereof and a compound having a phosphono group or a salt thereof in combination with a high temperature and a high alkali. In the water system under the conditions, it has been found that scale generation can be effectively prevented, and the present invention has been completed based on this finding.

That is, the present invention

(1) A method for preventing scino in an aqueous system under conditions of 50 to 25 ° C. and pH H≥9, wherein the polymer has a carboxyl group or a salt thereof, and the compound has a phosphono group. Or a scale prevention method that uses the salt as a glue for the ¾K system,

(2) A polymer having a carboxyl group or a salt thereof and a compound having a phosphono group ^) Or the salt weight ft ^ 匕 is 40:60 to 95: 5 (1),

(3) A compound having a phosphono group 1-hydroxyethylidene 1,1-diphosphonic acid (1) or (2) a method for preventing scales of soot, and

(4) A scenic deterrent for preventing scenole in an aqueous system under the conditions of 50 to 25 ° C. and pH H≥9, comprising a polymer having a carboxyl group or a salt thereof, and phosphono It is a squeeze agent that contains a group containing a group or a salt thereof. BEST MODE FOR CARRYING OUT THE INVENTION

The scale prevention method of the present invention is a method for inhibiting a sceno in a water system under conditions of 50 to 25 ° C. and pH 9, wherein a polymer having a carboxyl group or a salt thereof, and a phosphono group are added. The compound or salt thereof is added to the water system. The scale inhibitor of the present invention is a scaling inhibitor for preventing scaling in an aqueous system under conditions of 50 to 25 ° C. and pH ≥9, comprising a polymer having a carboxyl group or a salt thereof, and , Containing a phosphono group ^) or a salt thereof.

The method of the present invention or the water system under the conditions of 50 to 25 ° C. and pH ≥9 to which the inventive agent is applied is, for example, in a boiler can, 、 ¾Τ¾Μτ system, non-re: The cooking process can be cited as a night cooking process. In high alkaline water systems with a high temperature of 5 0-2500 ° C ρ Η 9, the scale does not adhere firmly to the solid surface, and the attached scale is removed. The method of the present invention or the drug of the present invention can be applied to ^ I.

Examples of the polymer having a carboxyl group used in the present invention include acrylo, methacrylo, crotonic acid, 3-butenoic acid, itaconic acid, sorbic acid, maleic acid, fumano, p-vininobenzoic acid, and salts thereof. Anhydrous anhydride, maleic acid and other monoesters such as fumarazo, copolymers thereof, copolymers with other monomers copolymerizable with these, and the like. Other monomers that can be copolymerized include, for example, vinyl sulphonic acid, sulphonyl sulphonic acid, vinyl phosphonic acid, 2-acrylamido-2-methinolepropane sulphonic acid, 2-hydroxy-1-sulyloxypropane sulphone. Acid, Styrene sulfonic acid, Isoprene sulfonic acid, (Meth) acrylo! ^ Methyl, (Meth) acryloethyl, (Meth) Atalino —7 Drokishchinole, Glycerol monoaryl ether, Arino oleanol, (Meth) acrylic Amide, N-alkyl (meth) acrylic amide, (meth) natalyl nitrinore, cocoon Examples include bulle, styrene, and isobutylene. Examples of the salt of the polymer having a carboxyl group used in the present invention include an ammonium salt, a sodium salt, and a potassium salt.

The weight average molecular weight of the polymer having a canolepoxyl group for use in the present invention is preferably from 3 00 to 50, 0, more preferably from 5 0 to 2 0, 0 0 0. Even if the weight-average molecular weight of the polymer having a casreboxyl group is less than 300 or more than 50,000, the SkeinoΙβ-stop effect may be reduced. On the other hand, if the weight average molecular weight of the polymer having a force / repoxyl group exceeds 50, 00, the viscosity at the night of the water will increase, and there is a possibility that the polarity will not be easy. The weight average molecular weight of the polymer having a carboxyl group used in the present invention can be determined by gel permeation chromatography using a polyethylene glycol having a molecular weight of »as the standard quality.

Production of a polymer having a carboxyl group used in the present invention; ^ is not particularly limited, and can be produced by polymerization, bulk polymerization or the like. A polymer having a carboxyl group can be suitably used for water-based polymerization using water as a starting material because the monomer of the raw material is water-soluble. In 7 灘 polymerization, prepare 5 ~ 50 weight *% water tank of monomer, replace the atmosphere with inert ft gas, cover at 50 ~ 100, and dissolve in water. Polymerization can be carried out by adding ½ ^. 7 For example, 4, 4'-azobis (4-cyanok ^), 2, 2'-azobis (2-methylpropionamidine), etc. | J, excess ammonia, i Examples include ^, trimethyl, «acidic lithium, and other peracids such as hydrogen peroxide, sodium periodate, and the like. In addition, alcohols and phosphorous can be used as chain transfer if necessary. The polymerization is usually completed in 3 to 6 hours, and a water tank of a polymer having a strong noroxyl group can be obtained by allowing to cool.

The compound having a phosphono group used in the present invention is a compound having a structure represented by the formula [1].

Having a phosphono group! For example, iminodi (methylene phosphone, nitori Tris (methylene phosphonic acid), ethylene diamine tetra (methylene phosphonic acid, hexame) ■ Tylenediamine tetra (methylene phosphonic acid, diethylene triamine penta (methylene phosphonic acid, 1-hydroxyxylidene 1, 1-diphosphonic acid, 2-phosphono 1, 2, 4 1 Butanetri force / levonic acid, etc. In addition, methacrylic acid 3-phosphonopropinole and other monomers having a phosphono group such as quaternary S-copolymers, copolymers, etc. Among these, 1-hydroxyethylidene-1,1-diphosphonic acid is particularly suitable because it has a large scale-preventing effect. A polymer having a carboxyl group or a salt thereof, and a compound having a phosphono group. The ratio of the amount of the salt added is not particularly limited, but the weight ratio of the polymer having a carboxyl group or a salt thereof to a compound having a phosphono group or a salt thereof is 40:60 to 95: 5. More preferably, it is 50:50 to 85:15: 15. A polymer having a carboxyl group or a salt thereof and a compound having a phosphono group or the weight of the salt: By setting the wings to 40:60 to 95: 5, a high scale prevention effect can be exhibited.

In the present invention, the amount of a polymer having a canolepoxyl group added to an aqueous system, or a compound having a phosphono group or a salt thereof can be adjusted depending on the water quality. Usually, it is preferable that the total concentration of the polymer having a canolepoxyl group or a phosphono group thereof or a salt thereof having a phosphono group or a salt thereof is 0.:! To 1, 0 0 0 OmgZL, 0.5 to 5 0, more preferred to be O mg ZL.

In the present invention, there is no particular limitation on the method of adding a polymer having a carboxyl group or a salt thereof and a compound having a phosphono group or a salt thereof to an aqueous system. For example, a polymer having a carboxyl group or a salt thereof, A compound having a phosphono group or a salt thereof can be mixed in advance and added to an aqueous system as ~ ^. Alternatively, a polymer having a carboxynole group or a salt thereof and a compound having a phosphono group or a salt thereof can be added. It can also be added to the water system separately.

In the present invention, there are no particular restrictions on the location where the polymer having a carboxyl group or a salt thereof and the compound having a phosphono group or a salt thereof are added to an aqueous system. For example, in the treatment in a boiler can, Or z Can be added directly to the drum. In the treatment of ΜΙ ^^ ΚτΚ system, it can be fed into the thickener treated water pit ¾¾¾, or it can be used as a massacre in circulating water, or it can be added to the slurry pit after the dust catcher. The In addition, in the processing of the digester in the non-regeneration process, it can be added directly to the kettle, can be added to the circulation line in the kettle, or added to the white liquor SB "in the kettle. In addition, in the night-making process of the manufacturing process, the rare tank can be added to the rare liquid feed line.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

In addition, in H½ examples, the polycarboxylic acids A to F shown in Table 1 were used as the polymer having a canolepoxyl group, and the phosphonic acids A to C shown in Table 1 were used as the compound having a phosphono group. .

Table 1

Example 1

Assuming a normal cooking process, sodium hydroxide (N a OH) 25, 00 Omg / L, sodium carbonate (Na ₂ C0 ₃ ) 15, 00 Omg / L, sodium sulfate (N a ₂ S ) 25,000 mgZlJ and calcium chloride H hydrate (C a C 1 ₂ 2H ₂ 0) 37 OmgZL was dissolved in water to prepare a simulated white liquor. The pH of this simulated white liquor exceeded 13 and the calcium concentration was 100 mgCa L.

Immerse 100 mL of simulated white liquor in a pressure vessel at A, 160 ° C oil bath for 1 hour, cool, filter with 5 C filter paper, and measure the calcium concentration in the filtrate by atomic absorption spectrometry. . The calcium concentration in the filtrate was 1 OmgCaZL.

In a pressure vessel, add 10 OmL of simulated white liquor containing 50 mg / L phosphonic acid A (utrilotri (methylenephosphonic acid) trisodium); τ, in the same way, heat at .160 ° C for 1 hour, then cool After filtration, the calcium concentration in the filtrate was measured. The calcium concentration was S mgCaZL, and the scale prevention rate was {1- (100-24) / (100-10)} Χ 00 = 16 (%).

In the simulated white liquor, the total concentration of poly strength norebonic acid A (polyacrylo ^) and phosphonic acid A (nitrite tri (methylethylenephosphonic sodium trisodium)) is reduced to 50 mgZL. After heating for 1 hour, cooling and filtering, the calcium concentration in the filtrate was measured, and the scale prevention rate was determined.

Table 2

Example 2

Using the polycarboxylic acid A (polyacrylo «and phosphonic acid B (1-hydroxyethylidene 1,1-diphosphonic acid), the same operation as in Example 1 was performed to obtain the result of the skeno H3 stopping rate. , Table 3 shows.

Table 3

Example 3.

Using polycarboxylic acid A (polyacrylolic acid) and phosphonic acid C (2-phosphonobutane 1,2,4, tritrinobononic acid), perform the same operation as in Example 1 to obtain the scale prevention rate. ^ The results are shown in Table 4. ,

Table 4

Example 4

Using the polycarboxylic acid B (polymaleic acid) and phosphonic acid B (l-hydroxyethylidene-1,1,)-diphosphonic swell, the same operation as in Example 1 was carried out to obtain the scale prevention rate. The results are shown in Table 5. Table 5

Example 5

Using the polycarboxylic acid B (polymaleic acid) and the phosphonic acid C (2-phosphonobutane 1,2,4,1 tricarboxylic acid, the same operation as in Example 1 was performed, and the scale prevention rate was obtained. Is shown in Table 6.

Table 6

Example 6

Using the same procedure as in Example 1 using polycarboxylic acid C (acrylic acid Z maleic acid copolymer sodium; ^) and phosphonic acid A (nitritritrimethylenephosphonic trisodium) Table 7 shows the 7to results. Table 7

Example "7

Polycarboxylic acid c (acrylolic acid z maleic acid copolymer sodium and phosphonic acid B

Using (1-hydroxyethylidene-1,1,1-diphosphonic acid), the same operation as in Example 1 was performed to determine the scale prevention rate. The results are shown in Table 8.

Table 8 ''

Example 8

Same as in difficult example 1 using polycarboxylic acid D (atalinoleic acid Z 2-hydroxyl-3-aryloxypropane sulfonic acid copolymer) and phosphonic acid B (l-hydroxyethylidene 1,1-diphosphone swell) The scale prevention rate was calculated and the results are shown in Table 9. Table 9

Male Example 9

The same operation as in Example 1 was carried out using polycarboxylic acid (atalinoleic acid maleic acid / vinyl acetate copolymer) and phosphonic acid B (1-hydroxyethylidene-1,1-diphosphonic acid). The scale prevention rate was determined. The results are shown in Table 10.

Table 10.

Example 1 0,

The same procedure as in Example 1 was performed using polycarboxylic acid F (malein / isobutylene copolymer) and phosphonic acid B (1-hydroxy shetilidene_1,1-diphosphonic acid) to determine the scaling rate. The results are shown in Table 11.

Table 1 1

As can be seen in Tables 2 to 11, Examples:! To 1 0 in all combinations Compared to the age when a polymer having a boxyl group or a salt thereof and a compound having a phosphono group or a salt thereof are inverted by a worm, the age at which both are used improves the scale prevention effect, and the weight ratio between the two is higher. At 60:40 or in the vicinity, the Skeino power stoppage rate is the maximum. Example 11

Assuming converter dust collection water for steel production, sodium bicarbonate (NaHC0 ₃ ) 1,344 _{mg /} L and calcium chloride; ΙτΙhydrate (C a C 1 ₂ · 2H ₂ 0) 73.5 mg / L in water After dissolution, use 赚 and sodium hydroxide syrup to adjust pH,

The Mo醒τΚ Me pH 9.5, acid consumption _(P H4.8) is 80 OmgCaC0 ₃ / L, calcium concentration was 20. OmgCaZL.

Put 10 OmL of water in a sealed container. (After heating for 1 hour in a constant temperature bath, it was cooled and filtered using 5 C filter paper, and the calcium concentration in the filtrate was measured by atomic absorption spectrometry. The calcium concentration in the filtrate was 3.2 mg CaZL. It was.

In a closed container, add phosphonic acid B (l-hydroxykitilidene_1, 1-diphosphone ^) 1. OMG / L added «^ JS water 10 OmL, and in the same way, at 70, 1 B temple After striking, it was cooled and filtered, and the calcium concentration in the filtrate was measured. The calcium concentration was 10.9mgCa ZL, and the scale inhibition rate was {1- (20.0-10.9) / (20.0-3.2)} X 100 = 4Θ (%).

Add the polycarboxylic acid Α (polyacryloleic acid) and phosphonic acid B (1-hydroxyethylidene-1,1-diphosphonic acid) to the model so that the total concentration is 1. Omg / L. Then, after heating at 70 ° C for 1 hour, cooling and filtering, the calcium concentration in the filtrate was measured, and the scale prevention rate was determined. The results are shown in Table 12.

Table 12

Example 12

Polycarboxylic acid c (Natrium and phosphonic acid B of attalic acid / maleic acid copolymer

Using (1-hydroxyethylidene 1,1-diphosphone ^), the same operation as in Example 11 was performed to determine the scale prevention rate. The results are shown in Table 13.

Table 13

Example 13

Example using polycarboxylic acid D (acrylic acid / 2-hydroxy _ 3-aryloxypropane sulfonic acid copolymer ^ (book) and phosphonic acid B (l-hydroxyethylidene_1,1-diphosphonic acid) The same procedure as in No. 11 was performed to determine the skeletal stopping rate, and the results are shown in Table 14. Table 14

Table 12 ~: As shown in Table 14, in all combinations of ¾6S Example 11-13, a polymer having a carboxyl group or a salt thereof and a salt of ^^! Having a phosphono group Compared to ^ used, both were used together: ^ improved the scaling effect, and when the weight of both was 60:40, the scaling rate was maximum. Example 14

No. 7 ^ Realistic fumigation angle, assuming a nightmare process? ¾ We used the extraction midnight night and performed a bowl. Extraction of Calcium Concentration 900 mg · C a / L Calcium chloride hydrate was added at night to adjust the calcium concentration to 56 Omg · Ca / L (six times the equivalent concentration). Immerse 100 mL of pressure in a pressure vessel in an oil bath at AL and 100 ° C for 1 hour, cool, and filter using 5 C filter paper, and measure the calcium concentration in the filtrate by atomic absorption spectrometry. did. The calcium concentration in the filtrate was 95 mg · CaZL.

10 OmL of phosphonic acid B (l-hydrochetylidene-1,1-diphosphonic acid) 10 Og / L added to the pressure vessel was soaked overnight at 100 X for 1 hour. After cooling, the mixture was filtered using 5 C filter paper, and the calcium concentration in the filtrate was measured by atomic absorption spectrometry. The calcium concentration in the filtrate is 155mg · Ca / L, and the skeno-retention rate is {1— (560—155) Z (560—95)} X 100 = 13 (%),

To the simulated black liquor, add polycarboxylic acid A (polyacryloleic acid) and phosphonic acid B (1-hydroxyethylidene 1-1,1-diphosphonic acid to a total concentration of 100 mg / L, and in the same way at 100 ° C After heating for 1 hour, cooling and filtering, the calcium concentration in the filtrate was measured, and the skeno stoppage rate was determined, and the results are shown in Table 15.

Table 15

Example 15

Using polycarboxylic acid B (polymaleic acid and phosphonic acid B (1-hydroxyethylidene-1,1-1 diphosphon ^), the same operation as in Example 14 was performed to determine the scale prevention rate. Table 16 shows. Scale inhibitor concentration (mg / L) Scale prevention rate

Polycarboxylic acid B Phosphonic acid B (%)

0 100 13

20 80 18

40 60 58

60 40 85

80 20 82

100 0 12

Example 16

The same procedure as in Example 14 was carried out using polycarboxylic acid C (acrylic acid / maleic acid copolymer sodium; ^ and phosphonic acid B (1-hydroxyethylidene-1,1-diphosphonic acid). The prevention rate was calculated and the results are shown in Table 17.

Table 17

Example 17

Using the polycarboxylic acid A (polyacryloleic acid) and the phosphonic acid C (2-phosphonobutane-1,2,4_tricarboxylic acid), the same operation as in Example 14 was carried out to determine the scaling rate. The results are shown in Table 18. Scale inhibitor concentration (mg / L) Scale prevention rate

Polycarboxylic acid A Phosphonic acid C (%)

0 100 1 7

20 80 22

40 60 68

60 40 70

80 20 65

100 0. 0

Example 18

Using the polycarboxylic acid B (polymaleic acid) and the phosphonic acid C (2-phosphonobutane 1,2,4-tricarboxylic bulge, the same operation as in Example 14 was performed to obtain the scale prevention rate. Table 19 shows.

Table 19

Example 19

The same operation as in Example 14 was performed using polycarboxylic acid C (acrylic acid / maleic acid copolymer sodium: ^) and phosphonic acid C (2-phosphonobutane 1,2,4-tricarboxylic acid). The scale prevention rate was calculated and the results are shown in Table 20. Table 20

Industrial applicability

According to the scale prevention method and scale inhibitor of the present invention, a polymer having a carboxyl group or a salt thereof and a salt having a phosphono group or a salt thereof are used in combination in an aqueous system under conditions of high temperature and high alkali. As a result, compared to the case of using each of them as insects, the effect of preventing a high level of scale can be exerted, and the amount of condensation can be reduced.

Claims

The scope of the claims

A method for preventing scale in an aqueous system under the conditions of 1.5 to 25 ° C. and pH H≥9, comprising a polymer having a strong lpoxyl group or a salt thereof, and a compound having a phosphono group or its Skeno that uses salt as a glue to ¾ system

2. The scale of claim 1 wherein the weight ratio of the polymer having a carboxyl group or a salt thereof to the compound having a phosphono group or the salt thereof is 40:60 to 95: 5 Prevention method.

3. Claim 1 or Claim 2 wherein the compound having a phosphono group is 1-hydroxyethylidene-1,1-diphosphonic acid;

4. An anti-scaling agent for preventing scale in an aqueous system under conditions of 50 to 25 ° C. and ρρ≥9, comprising a polymer having a carboxyl group or a salt thereof, and a phosphono group. An anti-scaling agent that has a martyrdom to contain it.