Efficient phosphorus-free gray water scale inhibition dispersant and preparation method thereof

Abstract

The invention relates to the technical field of gray water dispersing agents, and discloses an efficient phosphorus-free gray water scale inhibition dispersing agent and a preparation method thereof.The efficient phosphorus-free gray water scale inhibition dispersing agent is characterized in that a green amino acid monomer is adopted for conducting carboxyl end capping on a prepared polyether long-chain monomer containing carboxyl and sulfonic acid groups so as to improve the biodegradability of a macromolecular polyether monomer, and the efficient phosphorus-free gray water scale inhibition dispersing agent is obtained through copolymerization with an acrylic acid monomer; the steric hindrance and hydrophilicity of the dispersing agent are enhanced; carboxyl and sulfonic acid groups of the aspartic acid terminated polyether alkenyl monomer can chelate iron ions, hydrophilic groups such as amino groups and ether groups enable the chelate to be dissolved or suspended in a solution, and the dispersing performance is good; active carboxyl and sulfonic acid groups in a molecular chain are chelated with Ca < 2 + > and Ba < 2 + >, and a polyethylene glycol alkyl long chain enables zwitterions to have a certain mutual repulsive interaction; the scale inhibition dispersant integrates scale inhibition and dispersion functions, is free of phosphorus in a molecular structure, is easy to degrade after being discharged, and belongs to an environment-friendly multifunctional scale inhibition dispersant.

Description

Technical Field

[0001] The invention relates to the technical field of ash water dispersants, in particular to a high-efficiency phosphorus-free ash water scale inhibitor dispersant and a preparation method thereof. Background Art

[0002] Coal gasification ash water is a type of water that is prone to scaling during the water circulation process in the coal chemical industry. It has the characteristics of high hardness, high alkalinity, and a wide pH range. During the operation of the coal gasification water circulation, it is often accompanied by problems such as scaling and clogging of the pipeline. Therefore, the treatment of coal gasification ash water is an important environmental protection and production link. Through effective treatment processes, it can not only reduce the discharge of wastewater and reduce pollution to the environment, but also achieve the recycling of water resources and reduce production costs. At present, phosphorus-based formulas are popular at home and abroad, and are used in most of my country's coal gasification water circulation systems. However, the discharge of a large amount of phosphorus-containing wastewater can easily cause eutrophication of water bodies. With the continuous deterioration of water quality and the increasing hardness of water quality, the requirements for the discharge of phosphorus-containing wastewater at home and abroad are becoming increasingly stringent. Therefore, the preparation of a more efficient and environmentally friendly new type of ash water scale inhibitor dispersant has become a hot topic of current research.

[0003] The main function of the scale inhibitor and dispersant for coal gasification ash water is to disperse the suspended matter, microcrystals and other particles in the ash water through physical or chemical effects to prevent their aggregation and deposition; at the same time, it can also form stable complexes with hard water ions such as calcium and magnesium in the ash water to reduce their concentration, thereby inhibiting the formation of hard scale; polyaspartic acid is a water-soluble biopolymer material successfully developed under the inspiration of marine animal metabolism. The carboxyl group in its structure can change the crystal structure of calcium salts. Compared with traditional scale inhibitors and dispersants, it is completely biodegradable. Although polyaspartic acid has chelating properties, its scale inhibition and dispersing ability is not as good as the currently widely used acrylic acid and maleic acid polymers. Especially when polyaspartic acid is applied to high hardness water, the scale inhibition and dispersing effect is not satisfactory.

[0004] Invention patent CN108439618B discloses a coal gasification ash water scale inhibitor and a preparation method thereof, wherein a high molecular weight polymer is modified by oxidative degradation, sulfonation, selective amination and graft copolymerization, and the aminated modified product obtained by amination of the sulfonated modified product and the copolymerization product are mixed together to serve as a coal gasification ash water scale inhibitor, that is, the coal gasification ash water scale inhibitor finally obtained has a high scale inhibition rate; however, the natural polymer has many reaction sites, the reaction is uncontrollable, the preparation process is complicated, and the scope of application is limited; the present invention aims to achieve coordinated aggregation of multiple functional groups such as carboxyl, sulfonic acid, ester and polyethyleneoxy groups through molecular design, and prepare a multifunctional green scale inhibitor dispersant to broaden its application in coal gasification ash water dispersion. Summary of the invention

[0005] The purpose of the present invention is to solve the problems existing in the above-mentioned prior art and to provide a high-efficiency phosphorus-free ash water scale inhibitor and dispersant and a preparation method thereof, which has good scale inhibition and dispersibility and solves the problems of phosphorus pollution, single function, poor stability in use and small scope of application of current scale inhibitors and dispersants.

[0006] The present invention is achieved through the following technical solutions:

[0007] A method for preparing a highly efficient phosphorus-free ash water scale inhibitor dispersant comprises the following steps:

[0008] Step (1), under nitrogen atmosphere, add a solution of the structural formula The potassium olefin aspartate sulfonate monomer and N-methyl pyrrolidone are stirred evenly, and then 1000 polyethylene glycol monomethyl ether is added, stirred for reaction, and after the reaction is completed, vacuum distillation is performed to obtain an aspartic acid-terminated polyether-type olefin monomer. The preparation reaction formula is as follows:

[0009]

[0010] Step (2), under a nitrogen atmosphere, add deionized water, ammonium persulfate, sodium dodecylbenzene sulfonate and OP-10 to a reaction bottle equipped with a dropping funnel, and stir to dissolve; add a uniformly mixed mixture of methyl methacrylate, butyl acrylate, acrylic acid and aspartic acid-terminated polyether-type olefin monomer to the dropping funnel, first drop 1 / 3 of the mixture, react at 75-90° C. for 2-5 hours, then drop the remaining mixture, continue to react for 2-4 hours, after the reaction is completed, add ammonia water to adjust the pH to 7-8, and finally add emulsified silicone oil to obtain a high-efficiency phosphorus-free ash water scale inhibitor dispersant.

[0011] Preferably, in step (1), the molar ratio of the potassium alkenyl aspartate sulfonate monomer to the polyethylene glycol monomethyl ether 1000 is 1:1.2-1.5.

[0012] Preferably, in step (1), the reaction temperature is 90-110° C. and the reaction time is 3-8 h.

[0013] Preferably, in step (2), the mass ratio of deionized water, ammonium persulfate, sodium dodecylbenzene sulfonate, OP-10, methyl methacrylate, butyl acrylate, acrylic acid, aspartic acid-terminated polyether-type olefin monomer, and emulsified silicone oil is 20-35:2-4:3-6:5-8:100:30-40:5-10:3-15:0.5-2.

[0014] Preferably, the method for preparing potassium alkenyl aspartate sulfonate monomer in step (1) comprises the following steps:

[0015] Step S1: Add L-aspartic acid and methanol to a reaction flask under a nitrogen atmosphere, stir evenly, then add potassium 3-(acryloyloxy)propane-1-sulfonate, stir to react, and after the reaction is completed, concentrate under reduced pressure, separate by column chromatography (dichloromethane: methanol: ammonia water = 90:9:1), and obtain potassium aspartate sulfonate monomer. The preparation reaction formula is as follows:

[0016]

[0017] Step S2: Add potassium aspartate sulfonate monomer and N,N-dimethylformamide to a reaction flask under a nitrogen atmosphere, add acryloyl chloride and triethylamine after uniform dispersion, stir to react, add deionized water to extract after the reaction is completed, concentrate the organic phase, and separate by column chromatography (dichloromethane: methanol = 85:15) to obtain potassium alkenyl aspartate sulfonate monomer. The preparation reaction formula is as follows:

[0018]

[0019] Preferably, in step S1, the molar ratio of L-aspartic acid to potassium 3-(acryloyloxy)propane-1-sulfonate is 1:1.05-1.1.

[0020] Preferably, in step S1, the reaction temperature is 65-80° C. and the reaction time is 12-24 h.

[0021] Preferably, in step S2, the ratio of potassium aspartate sulfonate monomer, acryloyl chloride and triethylamine is 1:1.2-1.35:1.5-1.8.

[0022] Preferably, in step S2, the reaction temperature is 80-100° C. and the reaction time is 8-16 h.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The invention firstly utilizes the amino group of L-aspartic acid to carry out Michael addition reaction with the alkenyl group of 3-(acryloyloxy) propane-1-potassium sulfonate to obtain an aspartic acid potassium sulfonate monomer, then reacts with acryloyl chloride under the action of triethylamine to obtain an alkenyl aspartic acid potassium sulfonate monomer, then carries out esterification reaction with polyethylene glycol monomethyl ether 1000 to obtain an aspartic acid-terminated polyether-type alkenyl monomer, and finally polymerizes with an acrylic acid monomer to obtain a high-efficiency phosphate-free ash water scale inhibitor dispersant.

[0025] The invention adopts green amino acid monomers to perform carboxyl end-capping on prepared polyether long-chain monomers containing carboxyl groups and sulfonic acid groups, so as to improve the biodegradability of macromolecular polyether monomers, and enhances the steric hindrance and hydrophilicity of the dispersant by copolymerization with acrylic acid monomers, so as to have good scale inhibition and dispersing performance; the carboxyl groups and sulfonic acid groups of the aspartic acid end-capped polyether type alkenyl monomers can chelate iron ions, and the hydrophilic groups such as amino groups and ether groups can make the chelate dissolve or suspend in the solution, so as to prevent the precipitation of iron oxide and achieve the effect of dispersing iron oxide; the polyethylene glycol alkyl long-chain compound in the dispersant, as a solvation chain, can form an effective steric hindrance to prevent flocculation and precipitation between particles, so as to achieve the stable dispersion of iron ions in the medium.

[0026] Through the active carboxyl and sulfonic acid groups in the molecular chain of the scale inhibitor dispersant and Ca 2+ , Ba 2+ Chelation inhibits crystal nucleation and can be adsorbed on the pipe or container wall to effectively disperse particles, ensuring the long-term effectiveness of chelation scale inhibition and dispersion. 2+ , Ba 2+ It is not easy to form precipitation in an environment with high concentration; the long alkyl chain of polyethylene glycol makes the anions and cations repel each other to a certain extent, and the molecular chain stretches to reduce BaSO 4 、CaCO 3 The probability of crystal particles colliding with each other is reduced, so as to avoid crystal aggregation, precipitation and scaling. The scale inhibitor dispersant prepared by the present invention has both scale inhibition and dispersing functions, is suitable for coal gasification circulating water and other water that is prone to scaling, has no phosphorus in its molecular structure, is easily degraded after discharge, and is an environmentally friendly multifunctional scale inhibitor dispersant. DETAILED DESCRIPTION

[0027] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0028] Unless otherwise specified, the raw materials and reagents used in this application are commercially available or can be prepared by known methods.

[0029] L-Aspartic acid, CAS number is 56-84-8.

[0030] Potassium 3-(acryloyloxy)propane-1-sulfonate, CAS number is 31098-20-1.

[0031] Polyethylene glycol monomethyl ether 1000, CAS number is 9004-74-4.

[0032] Example 1

[0033] (1) Under a nitrogen atmosphere, 42 mmol of L-aspartic acid and 315 mL of methanol were added to a reaction flask. After stirring, 44.8 mmol of potassium 3-(acryloyloxy)propane-1-sulfonate was added, and the mixture was reacted at 75° C. for 16 h. The mixture was concentrated under reduced pressure and separated by column chromatography (dichloromethane:methanol:aqueous ammonia=90:9:1) to obtain potassium aspartate sulfonate monomer.

[0034] (2) Under nitrogen atmosphere, 35 mmol of potassium aspartate sulfonate monomer and 630 mL of N,N-dimethylformamide were added to the reaction flask. After uniform dispersion, 45.5 mmol of acryloyl chloride and 58.8 mmol of triethylamine were added. The mixture was reacted at 90° C. for 12 h. Deionized water was added for extraction. The organic phase was concentrated and separated by column chromatography (dichloromethane:methanol=85:15) to obtain potassium alkenyl aspartate sulfonate monomer.

[0035] (3) Under nitrogen atmosphere, 30 mmol of potassium olefin aspartate sulfonate monomer and 840 mL of N-methylpyrrolidone were added to a reaction flask equipped with a thermometer. After stirring evenly, 40.5 mmol of polyethylene glycol monomethyl ether 1000 was added, and the mixture was reacted at 100° C. for 5 h. The mixture was distilled under reduced pressure to obtain an aspartic acid-terminated polyether-type olefin monomer.

[0036] (4) Under nitrogen atmosphere, 25 g of deionized water, 3 g of ammonium persulfate, 5 g of sodium dodecylbenzene sulfonate and 7 g of OP-10 were added to a reaction bottle equipped with a dropping funnel and stirred to dissolve; a uniformly mixed solution of 100 g of methyl methacrylate, 35 g of butyl acrylate, 8 g of acrylic acid and 3 g of aspartic acid-terminated polyether-type olefin monomer was added to the dropping funnel, 1 / 3 of the mixture was first added dropwise, and the mixture was reacted at 80° C. for 3 h, and then the remaining mixture was added dropwise, and the reaction was continued for 2 h. After the reaction was completed, ammonia water was added to adjust the pH to 8, and finally 1.5 g of emulsified silicone oil was added to obtain a high-efficiency phosphorus-free ash water scale inhibitor dispersant.

[0037] Example 2

[0038] (1) Under a nitrogen atmosphere, 120 mmol of L-aspartic acid and 600 mL of methanol were added to a reaction flask. After stirring, 126 mmol of potassium 3-(acryloyloxy)propane-1-sulfonate was added. The mixture was reacted at 80° C. for 12 h, concentrated under reduced pressure, and separated by column chromatography (dichloromethane:methanol:aqueous ammonia=90:9:1) to obtain potassium aspartate sulfonate monomer.

[0039] (2) Under nitrogen atmosphere, 108 mmol of potassium aspartate sulfonate monomer and 1620 mL of N,N-dimethylformamide were added to the reaction flask. After uniform dispersion, 129.6 mmol of acryloyl chloride and 162 mmol of triethylamine were added. The mixture was reacted at 100° C. for 8 h. Deionized water was added for extraction. The organic phase was concentrated and separated by column chromatography (dichloromethane:methanol=85:15) to obtain potassium alkenyl aspartate sulfonate monomer.

[0040] (3) Under nitrogen atmosphere, 90 mmol of potassium olefin aspartate sulfonate monomer and 2250 mL of N-methylpyrrolidone were added to a reaction flask equipped with a thermometer. After stirring, 108 mmol of polyethylene glycol monomethyl ether 1000 was added, and the mixture was reacted at 110° C. for 3 h. The mixture was distilled under reduced pressure to obtain an aspartic acid-terminated polyether-type olefin monomer.

[0041] (4) Under nitrogen atmosphere, 20 g of deionized water, 2 g of ammonium persulfate, 3 g of sodium dodecylbenzene sulfonate and 5 g of OP-10 were added to a reaction bottle equipped with a dropping funnel and stirred to dissolve; a uniformly mixed solution of 100 g of methyl methacrylate, 30 g of butyl acrylate, 5 g of acrylic acid and 6 g of aspartic acid-terminated polyether-type olefin monomer was added to the dropping funnel, 1 / 3 of the mixture was first added dropwise, and the mixture was reacted at 90° C. for 2 h, and then the remaining mixture was added dropwise, and the reaction was continued for 2 h. After the reaction was completed, ammonia water was added to adjust the pH to 7, and finally 0.5 g of emulsified silicone oil was added to obtain a high-efficiency phosphorus-free ash water scale inhibitor dispersant.

[0042] Example 3

[0043] (1) Under a nitrogen atmosphere, 50 mmol of L-aspartic acid and 500 mL of methanol were added to a reaction flask. After stirring, 55 mmol of potassium 3-(acryloyloxy)propane-1-sulfonate was added. The mixture was reacted at 65° C. for 24 h, concentrated under reduced pressure, and separated by column chromatography (dichloromethane: methanol: ammonia water = 90:9:1) to obtain potassium aspartate sulfonate monomer.

[0044] (2) Under a nitrogen atmosphere, 45 mmol of potassium aspartate sulfonate monomer and 900 mL of N,N-dimethylformamide were added to a reaction flask. After uniform dispersion, 60.75 mmol of acryloyl chloride and 81 mmol of triethylamine were added. The mixture was reacted at 80° C. for 16 h. Deionized water was added for extraction. The organic phase was concentrated and separated by column chromatography (dichloromethane:methanol=85:15) to obtain potassium alkenyl aspartate sulfonate monomer.

[0045] (3) Under a nitrogen atmosphere, 40 mmol of potassium olefin aspartate sulfonate monomer and 1200 mL of N-methylpyrrolidone were added to a reaction flask equipped with a thermometer. After stirring evenly, 60 mmol of polyethylene glycol monomethyl ether 1000 was added, and the mixture was reacted at 90° C. for 8 h. The mixture was distilled under reduced pressure to obtain an aspartic acid-terminated polyether-type olefin monomer.

[0046] (4) Under nitrogen atmosphere, 35 g of deionized water, 4 g of ammonium persulfate, 6 g of sodium dodecylbenzene sulfonate and 8 g of OP-10 were added to a reaction bottle equipped with a dropping funnel and stirred to dissolve; a uniformly mixed solution of 100 g of methyl methacrylate, 40 g of butyl acrylate, 10 g of acrylic acid and 9 g of aspartic acid-terminated polyether-type olefin monomer was added to the dropping funnel, 1 / 3 of the mixture was first added dropwise, and the mixture was reacted at 75° C. for 5 h, and then the remaining mixture was added dropwise, and the reaction was continued for 4 h. After the reaction was completed, ammonia water was added to adjust the pH to 8, and finally 2 g of emulsified silicone oil was added to obtain a high-efficiency phosphorus-free ash water scale inhibitor dispersant.

[0047] Example 4

[0048] (1) Under a nitrogen atmosphere, 12 mmol of L-aspartic acid and 80 mL of methanol were added to a reaction flask. After stirring, 13 mmol of potassium 3-(acryloyloxy)propane-1-sulfonate was added. The mixture was reacted at 75° C. for 16 h, concentrated under reduced pressure, and separated by column chromatography (dichloromethane: methanol: ammonia water = 90:9:1) to obtain potassium aspartate sulfonate monomer.

[0049] (2) Under nitrogen atmosphere, 10 mmol of potassium aspartate sulfonate monomer and 185 mL of N,N-dimethylformamide were added to the reaction flask. After uniform dispersion, 13.5 mmol of acryloyl chloride and 16 mmol of triethylamine were added. The mixture was reacted at 95° C. for 15 h. Deionized water was added for extraction. The organic phase was concentrated and separated by column chromatography (dichloromethane:methanol=85:15) to obtain potassium alkenyl aspartate sulfonate monomer.

[0050] (3) Under a nitrogen atmosphere, 8 mmol of potassium olefin aspartate sulfonate monomer and 210 mL of N-methylpyrrolidone were added to a reaction flask equipped with a thermometer. After stirring evenly, 10 mmol of polyethylene glycol monomethyl ether 1000 was added, and the mixture was reacted at 105° C. for 6 h. The mixture was distilled under reduced pressure to obtain an aspartic acid-terminated polyether-type olefin monomer.

[0051] (4) Under nitrogen atmosphere, 30 g of deionized water, 3.5 g of ammonium persulfate, 4.5 g of sodium dodecylbenzene sulfonate and 7 g of OP-10 were added to a reaction bottle equipped with a dropping funnel and stirred to dissolve; a uniformly mixed solution of 100 g of methyl methacrylate, 32 g of butyl acrylate, 9 g of acrylic acid and 12 g of aspartic acid-terminated polyether-type olefin monomer was added to the dropping funnel, 1 / 3 of the mixture was first added dropwise, and the mixture was reacted at 80° C. for 5 h, and then the remaining mixture was added dropwise, and the reaction was continued for 3 h. After the reaction was completed, ammonia water was added to adjust the pH to 8, and finally 1 g of emulsified silicone oil was added to obtain a high-efficiency phosphorus-free ash water scale inhibitor dispersant.

[0052] Example 5

[0053] (1) Under a nitrogen atmosphere, 25 mmol of L-aspartic acid and 200 mL of methanol were added to a reaction flask. After stirring, 27 mmol of potassium 3-(acryloyloxy)propane-1-sulfonate was added, and the mixture was reacted at 70° C. for 24 h. The mixture was concentrated under reduced pressure and separated by column chromatography (dichloromethane:methanol:aqueous ammonia=90:9:1) to obtain potassium aspartate sulfonate monomer.

[0054] (2) Under nitrogen atmosphere, 18 mmol of potassium aspartate sulfonate monomer and 270 mL of N,N-dimethylformamide were added to the reaction flask. After uniform dispersion, 22.5 mmol of acryloyl chloride and 24 mmol of triethylamine were added. The mixture was reacted at 85° C. for 16 h. Deionized water was added for extraction. The organic phase was concentrated and separated by column chromatography (dichloromethane:methanol=85:15) to obtain potassium alkenyl aspartate sulfonate monomer.

[0055] (3) Under a nitrogen atmosphere, 12 mmol of potassium olefin aspartate sulfonate monomer and 320 mL of N-methylpyrrolidone were added to a reaction flask equipped with a thermometer. After stirring evenly, 16.2 mmol of polyethylene glycol monomethyl ether 1000 was added, and the mixture was reacted at 105° C. for 7 h. The mixture was distilled under reduced pressure to obtain an aspartic acid-terminated polyether-type olefin monomer.

[0056] (4) Under nitrogen atmosphere, 32 g of deionized water, 4 g of ammonium persulfate, 5 g of sodium dodecylbenzene sulfonate and 6 g of OP-10 were added to a reaction bottle equipped with a dropping funnel and stirred to dissolve; a uniformly mixed solution of 100 g of methyl methacrylate, 35 g of butyl acrylate, 7 g of acrylic acid and 15 g of aspartic acid-terminated polyether-type olefin monomer was added to the dropping funnel, 1 / 3 of the mixture was first added dropwise, and the mixture was reacted at 80° C. for 5 h, and then the remaining mixture was added dropwise, and the reaction was continued for 3 h. After the reaction was completed, ammonia water was added to adjust the pH to 8, and finally 1.5 g of emulsified silicone oil was added to obtain a high-efficiency phosphorus-free ash water scale inhibitor dispersant.

[0057] Comparative Example 1

[0058] Under a nitrogen atmosphere, 25 g of deionized water, 3 g of ammonium persulfate, 5 g of sodium dodecylbenzene sulfonate and 7 g of OP-10 were added to a reaction bottle equipped with a dropping funnel, and stirred to dissolve; a uniformly mixed mixture of 100 g of methyl methacrylate, 35 g of butyl acrylate, 8 g of acrylic acid and 3 g of potassium aspartate sulfonate monomer (prepared in Example 1) was added to the dropping funnel, 1 / 3 of the mixture was first added dropwise, and the reaction was carried out at 80° C. for 3 h, and then the remaining mixture was added dropwise, and the reaction was continued for 2 h. After the reaction was completed, ammonia water was added to adjust the pH to 8, and finally 1.5 g of emulsified silicone oil was added to obtain a phosphorus-free ash water scale inhibitor dispersant.

[0059] Comparative Example 2

[0060] Under a nitrogen atmosphere, 25 g of deionized water, 3 g of ammonium persulfate, 5 g of sodium dodecylbenzene sulfonate and 7 g of OP-10 were added to a reaction bottle equipped with a dropping funnel and stirred to dissolve; a uniformly mixed mixture of 100 g of methyl methacrylate, 35 g of butyl acrylate, 8 g of acrylic acid and 3 g of potassium 3-(acryloyloxy)propane-1-sulfonate was added to the dropping funnel, 1 / 3 of the mixture was first added dropwise, and the reaction was carried out at 80°C for 3 h, and then the remaining mixture was added dropwise, and the reaction was continued for 2 h. After the reaction was completed, ammonia water was added to adjust the pH to 8, and finally 1.5 g of emulsified silicone oil was added to obtain a phosphorus-free ash water scale inhibitor dispersant.

[0061] Comparative Example 3

[0062] Under a nitrogen atmosphere, 25 g of deionized water, 3 g of ammonium persulfate, 5 g of sodium dodecylbenzene sulfonate and 7 g of OP-10 were added to a reaction bottle equipped with a dropping funnel and stirred to dissolve; a uniformly mixed solution of 100 g of methyl methacrylate, 35 g of butyl acrylate and 8 g of acrylic acid was added to the dropping funnel, 1 / 3 of the mixture was first added dropwise, and the reaction was carried out at 80°C for 3 h, and then the remaining mixture was added dropwise, and the reaction was continued for 2 h. After the reaction was completed, ammonia water was added to adjust the pH to 8, and finally 1.5 g of emulsified silicone oil was added to obtain a phosphorus-free ash water scale inhibitor dispersant.

[0063] Dispersion performance test: 8 groups of Ca 2+ To a solution with a mass concentration of 150 mg / L, 100 mg of the scale inhibitor and dispersant prepared in the examples and comparative examples were added, and ferrous sulfate heptahydrate was added to make Fe 2+ The concentration of the solution is 10 mg / L, and the volume is adjusted to 500 mL. At the same time, a blank test is performed. The pH value of the solution is adjusted to 9 with sodium tetraborate. When the pH value is stable, stir vigorously for 15 minutes, and then let it stand in a 50°C water bath for 5 hours. Take the upper clear liquid and use a visible light spectrophotometer to measure the transmittance T at 420 nm and 3 cm colorimetric cell. The smaller the transmittance, the better the dispersion effect.

[0064] Table 1 Dispersion performance test

[0065] Transmittance T(%) Example 1 46.4 Example 2 37.1 Example 3 29.6 Example 4 23.0 Example 5 22.7 Comparative Example 1 50.3 Comparative Example 2 68.2 Comparative Example 3 83.9

[0066] The transmittance reflects the turbidity of the solution. The transmittance can be used to evaluate the performance of the polymer in dispersing iron oxide. Ferrous sulfate heptahydrate generates ferrous hydroxide in an alkaline solution and is then oxidized into iron oxide. If the dispersion performance of the polymer is poor, the iron oxide will precipitate and the transmittance of the solution will be large. Conversely, the smaller the transmittance, the better the dispersion performance of the polymer.

[0067] It can be seen from the test results in the above table that with the increase of the content of aspartic acid-terminated polyether-type alkenyl monomer, the dispersibility of the gray water scale inhibitor dispersant is gradually enhanced, wherein the transmittance in Example 4 is only 23.0%, because on the one hand, the carboxyl group and sulfonic acid group of the aspartic acid-terminated polyether-type alkenyl monomer can chelate iron ions, and the hydrophilic groups such as amino groups and ether groups make the chelate dissolved or suspended in the solution, thereby preventing the precipitation of iron oxide and achieving the effect of dispersing iron oxide; on the other hand, the polyethylene glycol alkyl long-chain compound as a solvation chain can form an effective steric hindrance to prevent flocculation and precipitation between particles, thereby achieving the stable dispersion of iron ions in the medium; when the dosage reaches the critical value, the aspartic acid-terminated polyether-type alkenyl monomer can ionize enough carboxylic acid and sulfonic acid groups to chelate most of the free iron ions in the solution, the functional groups reach saturation, and the effect of reducing the transmittance is no longer significant.

[0068] Comparative Example 1 contains carboxylic acid and sulfonic acid chelating functional groups, but does not contain polyethylene glycol long chains, and has a certain dispersing effect; Comparative Example 2 does not contain polyethylene glycol long chain groups, does not have a synergistic dispersing effect, and has limited chelating effect; Comparative Example 3 does not add functional groups, and has the worst dispersing performance.

[0069] Anti-scaling performance test: Tested in accordance with standard HG / T 2024-2009. The principle of the method is quantitative CaCl 2 、BaCl 2 With quantitative NaHCO 3 Or Na 2 SO 4 Reaction to form CaCO 3 ,BaSO 4 Precipitation, in which the reaction generates CaCO 3 ,BaSO 4 Before precipitation, the prepared ash water anti-scaling dispersant and the unprepared ash water anti-scaling dispersant were added to the solution, and the solution was kept at a constant temperature for a period of time, and the Ca content in the clear solution was measured. 2+ and Ba 2+ Content, calculate the scale inhibition rate.

[0070] CaCl 2Solution preparation: weigh 13.86g of anhydrous calcium chloride and dissolve it in water. 2+ 5mg / mL).

[0071] NaHCO 3 Solution preparation: weigh 9.92 g of NaHCO 3 Dissolve in water and dilute to volume in a 1L volumetric flask (with HCO 3 - Total 7.29 mg / mL).

[0072] Disodium ethylenediaminetetraacetic acid (EDTA) solution: 0.01 mol / L standard solution.

[0073] Calcium indicator: 0.2g calcium carboxylic acid is thoroughly mixed with 100g calcium chloride and ground to 40-50 mesh.

[0074] Test steps: Add 200mL of deionized water to a 250mL volumetric flask, and use a burette to add 10mL of 5mg / mL Ca 2+ The solution was mixed with 100 mg of the scale inhibitor dispersant prepared in the examples and comparative examples, and then shaken well and 10 mL of HCO with a mass concentration of 7.29 mg / mL was added. 3 - Solution was diluted to the mark with deionized water, shaken, and placed in a 250 mL stoppered conical flask and allowed to stand at 70 °C for 10 h. During the experiment, an experiment without adding dispersant was carried out at the same time, and the other steps were the same to obtain a blank solution 1.

[0075] The experiment was carried out without adding HCO 3- For the experiment of solution and dispersant, the rest of the steps are the same to obtain blank solution 2; take out each stoppered conical flask and let it stand to room temperature, take 50mL of deionized water into a clean conical flask, accurately transfer 25mL of filtrate, mix well, add 10mL of 4% sodium hydroxide solution and 3mL of calcium indicator, and add 0.01mol / L EDTA standard solution until it turns pure blue.

[0076] Scale inhibition rate = [ρ(Ca 2+ 2 )-ρ(Ca 2+ 1 )] / [ρ(Ca 2+ )-ρ(Ca 2+ 1 )]×100%.

[0077] Where ρ(Ca 2+ ) is the Ca added to the ash water scale inhibitor 2+ concentration, ρ(Ca 2+ 1 ) is the Ca in blank solution 12+ concentration, ρ(Ca 2+ 2 ) is the Ca in blank solution 2 2+ concentration.

[0078] BaSO 4 Scale inhibition test: Add 200mL of deionized water to a 250mL volumetric flask, and use a burette to add 5mL of Ba with a mass concentration of 2.81mg / mL. 2+ Solution, add 100 mg of the gray water scale inhibitor prepared in the examples and comparative examples, shake well and add 5 mL of SO with a mass concentration of 2.06 mg / mL 4 2- The solution was diluted to the mark with deionized water, shaken, and placed in a 250 mL stoppered flask and allowed to stand at 70 °C for 10 h. The experiment without adding dispersant was also carried out, and the other steps were the same to obtain blank solution 1. The experiment without adding SO 4 2- The remaining steps of the experiment of solution and dispersant were the same to obtain blank solution 2.

[0079] Table 2 Scale inhibition performance test

[0080]

[0081]

[0082] From the test results in the table above, it can be seen that with the increase of the content of aspartic acid-terminated polyether-type olefin monomer, the dispersant can be 2+ , Ba 2+ The content of chelated groups increases, and the scale inhibition performance is significantly improved; through the active carboxyl and sulfonic acid groups in the molecular chain and Ca 2+ , Ba 2+ Chelation inhibits crystal nucleation and can be adsorbed on the pipe or container wall to effectively disperse particles, ensuring the long-term effectiveness of chelation scale inhibition and dispersion. 2+ , Ba 2+ It is not easy to form precipitation in an environment with high concentration; the long alkyl chain of polyethylene glycol makes the anions and cations repel each other to a certain extent, and the molecular chain stretches to reduce BaSO 4 、CaCO 3 The probability of crystal particles colliding with each other can be reduced to avoid crystal aggregation, precipitation and scaling.

[0083] The above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing a highly efficient non-phosphate ash water scale inhibitor dispersant, characterized in that: The preparation method comprises the following steps: Step (1), under nitrogen atmosphere, add a solution of the structural formula The potassium olefin aspartate sulfonate monomer and N-methyl pyrrolidone are stirred evenly, and then 1000 polyethylene glycol monomethyl ether is added, and the mixture is stirred for reaction. After the reaction is completed, the mixture is distilled under reduced pressure to obtain an aspartic acid-terminated polyether-type olefin monomer; Step (2), under a nitrogen atmosphere, add deionized water, ammonium persulfate, sodium dodecylbenzene sulfonate and OP-10 to a reaction bottle equipped with a dropping funnel, and stir to dissolve; add a uniformly mixed mixture of methyl methacrylate, butyl acrylate, acrylic acid and aspartic acid-terminated polyether-type olefin monomer to the dropping funnel, first drop 1 / 3 of the mixture, react at 75-90° C. for 2-5 hours, then drop the remaining mixture, continue to react for 2-4 hours, after the reaction is completed, add ammonia water to adjust the pH to 7-8, and finally add emulsified silicone oil to obtain a high-efficiency phosphorus-free ash water scale inhibitor dispersant.

2. The method for preparing the high-efficiency non-phosphate ash water scale inhibitor dispersant according to claim 1, characterized in that: In the step (1), the molar ratio of the potassium alkenyl aspartate sulfonate monomer to the polyethylene glycol monomethyl ether 1000 is 1:1.2-1.

5.

3. The method for preparing the high-efficiency non-phosphate ash water scale inhibitor dispersant according to claim 1, characterized in that: In the step (1), the reaction temperature is 90-110° C. and the reaction time is 3-8 h.

4. The method for preparing a highly efficient non-phosphate ash water scale inhibitor and dispersant according to claim 1, characterized in that: In the step (2), the mass ratio of deionized water, ammonium persulfate, sodium dodecylbenzene sulfonate, OP-10, methyl methacrylate, butyl acrylate, acrylic acid, aspartic acid-terminated polyether-type olefin monomer, and emulsified silicone oil is 20-35:2-4:3-6:5-8:100:30-40:5-10:3-15:0.5-2.

5. The method for preparing a highly efficient non-phosphate ash water scale inhibitor and dispersant according to claim 1, characterized in that: The method for preparing the potassium alkenyl aspartate sulfonate monomer in step (1) comprises the following steps: Step S1, under a nitrogen atmosphere, add L-aspartic acid and methanol to a reaction flask, stir evenly, add potassium 3-(acryloyloxy)propane-1-sulfonate, stir to react, and after the reaction is completed, concentrate under reduced pressure, separate by column chromatography (dichloromethane: methanol: ammonia water = 90:9:1), and obtain potassium aspartate sulfonate monomer; Step S2, under a nitrogen atmosphere, add potassium aspartate sulfonate monomer and N,N-dimethylformamide to a reaction flask, and after uniform dispersion, add acryloyl chloride and triethylamine, and stir to react. After the reaction is completed, add deionized water for extraction, concentrate the organic phase, and separate by column chromatography (dichloromethane: methanol = 85:15) to obtain potassium alkenyl aspartate sulfonate monomer.

6. The method for preparing the high-efficiency non-phosphate ash water scale inhibitor and dispersant according to claim 5, characterized in that: In the step S1, the molar ratio of L-aspartic acid to potassium 3-(acryloyloxy)propane-1-sulfonate is 1:1.05-1.

1.

7. The method for preparing a highly efficient non-phosphate ash water scale inhibitor and dispersant according to claim 5, characterized in that: In step S1, the reaction temperature is 65-80° C. and the reaction time is 12-24 h.

8. The method for preparing a highly efficient non-phosphate ash water scale inhibitor and dispersant according to claim 5, characterized in that: In the step S2, the ratio of potassium aspartate sulfonate monomer, acryloyl chloride and triethylamine is 1:1.2-1.35:1.5-1.

8.

9. The method for preparing a highly efficient non-phosphate ash water scale inhibitor and dispersant according to claim 5, characterized in that: In step S2, the reaction temperature is 80-100° C. and the reaction time is 8-16 hours.

10. A highly efficient non-phosphate ash water scale inhibitor dispersant, characterized in that: Obtained by the preparation method according to any one of claims 1 to 9.

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