WO2021168909A1 - Hyperbranched phosphorus-free scale inhibitor and preparation method therefor - Google Patents

Abstract

A hyperbranched phosphorus-free scale inhibitor is prepared from polyvinylamine, aspartic acid and an analog thereof, ethylenediaminetetraacetic acid and an analog thereof, a tricarboxylic acid, a cross-linking agent, an inorganic base, a graphene dispersion, and water. The mass ratio of polyvinylamine, aspartic acid and the analog thereof, and ethylenediaminetetraacetic acid and the analog thereof is 1-2:4-5:1. The mass of water is 1-1.5 times the sum of the masses of polyvinylamine, aspartic acid and the analog thereof, and ethylenediaminetetraacetic acid and the analog thereof. The amount of the cross-linking agent is 0.5-0.8% of the weight of water. The amount of the graphene dispersion is 1.5-2g/L water. The amount of tricarboxylic acid is 0.5-0.8% of the weight of water. The amount of the inorganic base is 0.6-0.8mol/L water. Said phosphorus-free scale inhibitor product can have good inhibiting effects on carbonates, sulfates, metal oxides and silica, and is green and environmentally friendly.

Description

Hyperbranched phosphorus-free scale inhibitor and preparation method thereof Technical field

The invention relates to an environmentally friendly scale and corrosion inhibitor, in particular to a hyperbranched phosphorus-free scale inhibitor and a preparation method thereof.

Background technique

As people pay more and more attention to water resources and environmental protection, more companies use membrane systems for reclaimed water to reduce emissions. In order to reduce and prevent fouling of the membrane system, it is necessary to use antiscalant products to inhibit fouling of the system. However, since the water quality of the reused reclaimed water is much worse than that of the conventional surface water or groundwater, the water quality of this type of water, especially for the reuse of some landfill leachate and printing and dyeing wastewater, is generally subjected to biochemical treatment before the water is pretreated into the membrane. , The content of microorganisms is high, the content of macromolecular organic matter in the water after biochemical treatment is still more than 50mg/L, and the membrane has the characteristics of high water hardness, high sulfate, and high metal oxide content. Once the above pollutants are present, the reverse osmosis membrane is very easy to foul and block, and it is difficult to clean after fouling, and it is difficult to clean after fouling, which causes some systems to need to be cleaned every 1 to 2 months, while some systems even half It must be cleaned within a few months, which will seriously affect the service life of the membrane.

At present, domestic and foreign scale inhibitors are mainly phosphonic acid corrosion and scale inhibitors, whose main characteristics are good corrosion inhibition effect and low price. However, it is easy to form phosphate scale and cause eutrophication of the water body, and ultimately promote the growth and reproduction of microorganisms. At the same time, organic phosphine corrosion inhibitors are also corrosive to copper and copper alloys. Therefore, with increasing attention to environmental protection, the above corrosion and scale inhibitors do not conform to the concept of green and environmental protection, and will gradually be replaced by phosphorus-free environmentally friendly corrosion and scale inhibitors.

Summary of the invention

The present invention aims to overcome the above-mentioned defects and provide a scale and corrosion inhibitor which adopts a non-phosphorus water treatment formula and has excellent effects.

The invention provides a hyperbranched phosphorus-free scale inhibitor, which is characterized in that it is composed of polyvinylamine (preferably polyvinylamine with a molecular weight of 8000-12000), aspartic acid and its analogs, ethylenediaminetetraacetic acid and its Manufactured from analogs, tricarboxylic acids, crosslinking agents, inorganic bases, graphene dispersions, and water:

Wherein, the mass ratio of the above-mentioned polyvinylamine, aspartic acid and its analogs, ethylenediaminetetraacetic acid and its analogs is 1-2:4-5:1;

The mass of the above water is 1 to 1.5 times the sum of the masses of polyvinylamine, aspartic acid and its analogues, ethylenediaminetetraacetic acid and its analogues;

The amount of the above-mentioned crosslinking agent is 0.5-0.8% of the weight of water;

The dosage of the graphene dispersion liquid is 1.5-2g/L water;

The amount of the above-mentioned tricarboxylic acid is 0.5-0.8% of the weight of water;

The amount of the above-mentioned inorganic base is 0.6-0.8 mol/L water.

Further, the hyperbranched phosphorus-free scale inhibitor provided by the present invention is also characterized in that the above-mentioned aspartic acid and its analogs are selected from any of aspartic acid, alkali metal salts of aspartic acid or alkaline earth metal salts. One or several compounds.

Further, the hyperbranched phosphorus-free scale inhibitor provided by the present invention is also characterized in that the above-mentioned ethylenediaminetetraacetic acid and its analogs are selected from ethylenediaminetetraacetic acid, alkali metal salts of ethylenediaminetetraacetic acid or alkaline earth metals One or more of the salt.

Furthermore, the hyperbranched phosphorus-free scale inhibitor provided by the present invention is also characterized in that: the above-mentioned tricarboxylic acid is selected from any one or two of citric acid and nitrilotriacetic acid.

Furthermore, the hyperbranched phosphorus-free scale inhibitor provided by the present invention is also characterized in that the crosslinking agent is any one of hydroxyethyl acrylate and triethanolamine.

Further, the hyperbranched phosphorus-free scale inhibitor provided by the present invention is also characterized in that the above-mentioned inorganic base is selected from one or more of alkali metal salts or alkaline earth metal hydroxides.

Furthermore, the hyperbranched phosphorus-free scale inhibitor provided by the present invention is also characterized in that: the preparation method of the graphene dispersion liquid is: adding a reducing agent and a dispersant to the graphene oxide dispersion liquid under normal temperature and pressure, Graphene dispersion formed by reduction reaction;

The mass ratio of the graphene oxide dispersion liquid: reducing agent: dispersing agent is 3-30:1:1;

Among them, preferably, the mass ratio of graphene oxide: reducing agent: dispersing agent in the graphene oxide dispersion liquid is 3:1:1;

The solid content of the graphene dispersion is 0.1-1%, and the total oxygen content is 1%-9%.

The above reducing agent is sodium bisulfite or sodium metabisulfite;

The above-mentioned dispersant is a sodium polyacrylate dispersant;

The reduction reaction time is 0.5-5 hours.

In the present invention, the effect of using the above method to obtain the graphene dispersion is that due to the addition of the reducing agent, the graphene dispersion can also function as a protective film.

Furthermore, the hyperbranched non-phosphorus scale inhibitor provided by the present invention is also characterized in that the thickness of the graphene dispersion liquid is 0.55 to 3.74 μm, and the microplate size is 0.5 to 3 μm.

Further, the hyperbranched non-phosphorus scale inhibitor provided by the present invention is also characterized in that: in the reactor, the temperature is controlled to be 40-50°C, water, graphene dispersion, crosslinking agent, and inorganic alkali are added, and stirred at low speed. After 10-30min, then add polyvinylamine, aspartic acid and its analogues, ethylenediaminetetraacetic acid and its analogues, and tricarboxylic acid to the reactor and mix evenly to obtain hyperbranched phosphorus-free scale inhibitor Agent

Wherein, the total dropping time of the above-mentioned polyethyleneimine, aspartic acid and its analogs, ethylenediaminetetraacetic acid and its analogs is controlled within 2 to 3 hours.

Furthermore, the hyperbranched phosphorus-free scale inhibitor provided by the present invention is also characterized in that the dosage of the above-mentioned phosphorus-free scale inhibitor is controlled at 1 to 5 ppm.

The function and effect of the present invention:

The dosage of the scale inhibitor is controlled at 1～5ppm, which can effectively inhibit any one or more of carbonate, sulfate, metal oxide, and silica from fouling the membrane system, and the product has good stability , Green, phosphorus-free and environmentally friendly.

Detailed ways

Example 1

In the reactor, control the temperature to 40-50℃, add water, graphene dispersion, cross-linking agent (triethanolamine), inorganic alkali, stir at low speed for 10-30min, and then add dropwise polymerization within 2-3 hours. Ethyleneamine (molecular weight 10000), aspartic acid, ethylenediaminetetraacetic acid, and tricarboxylic acid (citric acid) are mixed uniformly in the reactor to obtain a hyperbranched phosphorus-free scale inhibitor.

The mass ratio of polyvinylamine, aspartic acid and its analogs, ethylenediaminetetraacetic acid and its analogs is 1:4:1;

The mass of the water is 1 time the sum of the masses of polyvinylamine, aspartic acid and its analogues, ethylenediaminetetraacetic acid and its analogues;

The amount of the crosslinking agent is 0.5% of the weight of the water;

The amount of the graphene dispersion is 2g/L water;

The amount of the tricarboxylic acid is 0.8% of the weight of water;

The amount of the inorganic base is 0.8mol/L water

The preparation method of graphene dispersion is as follows: under normal temperature and pressure, in a commercially available graphene oxide dispersion (preferably a graphene oxide dispersion prepared by a modified chemical Hummer method, the oxygen content is between 15-30%, The pH value is between 5-7 and the concentration is 2-6mg/ml), adding reducing agent and dispersant, the graphene dispersion formed by the reduction reaction (the end of the reaction is determined by the total oxygen content of the product);

The mass ratio of the graphene oxide dispersion liquid: reducing agent: dispersing agent is 3:1:1;

The above reducing agent is sodium bisulfite;

The above dispersant is sodium polyacrylate.

The solid content of the graphene dispersion liquid is between 0.4-0.5%, and the total oxygen content is between 3% and 5%;

The thickness of the upper graphene dispersion is about 1.54 μm, and the microplate size is about 0.8 μm.

The method of use is: the dosage is 1-5ppm.

Test method 1:

(A) Test object: Membrane system that treats the same water quality;

(B) Take the hyperbranched non-phosphorus scale inhibitor of this embodiment, and the dosage is 1ppm (B1), 2ppm (B2), 5ppm (B3);

(C) Take a commercially available non-phosphorus scale inhibitor, with a dosage of 1ppm (C1), 2ppm (C2), 5ppm (C3);

After the same treatment and time (1 month), through the B and C groups, the parallel comparison of the growth rate of scale from small to large is as follows: B3＜B2＜B1＜＜C3＜C2＜C1

Test method 2:

Test object: the hyperbranched non-phosphorus scale inhibitor of this embodiment;

1. Aiming at the anti-scaling effect of calcium carbonate:

(1) Take 3 sets of clean 100ml volumetric flasks and add 1/3 of deionized water;

(2) Add 1.2ml (600ppm calcium carbonate) calcium chloride solution to the 3 sets of volumetric flasks respectively, and analogously 1.6ml (800ppm calcium carbonate), 2ml (1000ppm calcium carbonate), 3ml (1500ppm calcium carbonate)...);

(3) Add 5 ppm of the hyperbranched non-phosphorus scale inhibitor of this embodiment to the 3 groups of volumetric flasks and make the blank group (by analogy, 5ppm, 10ppm, 20ppm...);

(4) Add 1ml buffer to 3 groups of volumetric flasks;

(5) Add 2.4ml (600ppm calcium carbonate) sodium bicarbonate solution to the 3 sets of volumetric flasks respectively (by analogy 3.2ml (800ppm calcium carbonate), 4ml (1000ppm calcium carbonate), 6ml (1500ppm calcium carbonate)...);

(6) Make the volume up to 100ml with deionized water, shake it enough, transfer it to a container prepared in advance, and place it in a sealed container for 24 hours;

(7) Dilute 1.2ml of calcium chloride solution to 100ml with a volumetric flask and make standard sample 1;

(8) Calibrate after 24h, take 5ml of the test solution, add 80ml of deionized water, add 5ml of potassium hydroxide solution, add about 0.5g of calcium carboxylic acid indicator, and titrate with edta solution to change from purple to bright blue. For the end.

(9)

V2: Take the average of the edta consumption of the solution after adding the scale inhibitor in three groups (the difference between the three groups of data should be within 0.1ml, and discard the abnormal data value)

V1: Average value of edta consumption without scale inhibitor solution (the difference between the three groups of data should be within 0.1ml, and the abnormal data value is discarded)

V0: The edta value consumed by the standard sample made of calcium chloride

By calculating the scale inhibition rate, it can be seen that the hyperbranched phosphorus-free scale inhibitor of this embodiment is better than the scale inhibition effect lacking any kind of raw material, and when LSI≈3, it can still achieve a scale inhibition effect of more than 90%.

2. Anti-scaling effect of calcium sulfate:

(1) Take 5 sets of clean 100ml volumetric flasks and add 1/3 of deionized water;

(2) Add 7.35ml (5000ppm calcium sulfate) calcium chloride solution to the 5 sets of volumetric flasks respectively (by analogy 10.3ml (7000ppm calcium sulfate), 13.2ml (9000ppm calcium sulfate)...);

(3) Add 5ppm scale inhibitor to the 5 groups of volumetric flasks and make the blank group (10ppm, 20ppm...);

(4) Add 7.35ml (5000ppm calcium carbonate) sodium bicarbonate solution to 5 sets of volumetric flasks respectively (by analogy 10.3ml (7000ppm calcium sulfate), 13.2ml (9000ppm calcium sulfate)...);

(5) Dilute the volume to 100ml with deionized water, shake it enough, transfer it to a pre-prepared container, and place it in an airtight container for 24 hours;

(6) Dilute 1.2ml of calcium chloride solution to 100ml with a volumetric flask and make standard sample 1;

(7) Calibrate after 24h, take 1ml of the test solution, add 80ml of deionized water, add 5ml of potassium hydroxide solution, add about 0.5g of calcium carboxylic acid indicator, and titrate with edta solution to change from purple to bright blue. For the end.

V2: Take the average of the edta consumption of the solution after adding the scale inhibitor in three groups (the difference between the three groups of data should be within 0.1ml, and discard the abnormal data value)

V1: Average value of edta consumption without scale inhibitor solution (the difference between the three groups of data should be within 0.1ml, and the abnormal data value is discarded)

V0: The edta value consumed by the standard sample made of calcium chloride

By calculating the scale inhibition rate, it can be seen that the hyperbranched phosphorus-free scale inhibitor of this embodiment is better than the scale inhibition effect lacking any kind of raw material, and when the calcium sulfate concentration reaches 9000mg/L, it can still achieve a scale inhibition effect of 90%. Above, compared with the scale inhibitors sold in the market, the scale inhibition effect is obvious.

3. Anti-scaling effect of calcium phosphate:

(1) Take 3 sets of clean 100ml volumetric flasks and add 1/3 of deionized water;

(2) Add 0.58ml 0.05mol/L calcium chloride solution (0.97ml (50ppm calcium phosphate) in turn) into 3 groups of volumetric flasks;

(3) Add 5ppm, 10ppm, and 20ppm scale inhibitors to the 3 groups of volumetric flasks and make the blank group;

(4) Add 0.39ml 0.05mol/L sodium phosphate solution to the 3 sets of volumetric flasks (by analogy 0.65ml (50ppm calcium phosphate));

(5) Dilute the volume to 100ml with deionized water, shake well and transfer it to a container prepared in advance, and place it in a sealed container for 24h; take 0.58ml of calcium chloride solution and dilute it to 100ml with a volumetric flask, and make standard 1;

(6) Calibrate after 24h, take 5ml of the test solution, add 80ml of deionized water, add 5ml of potassium hydroxide solution, add about 0.5g of calcium carboxylic acid indicator, titrate with 0.001mol/L edta solution to change from purple to red Bright blue is the end point.

(7)

V2: Take the average of the edta consumption of the solution after adding the scale inhibitor in three groups (the difference between the three groups of data should be within 0.1ml, and discard the abnormal data value)

V1: The average value of edta consumption without scale inhibitor solution (the difference between the three groups of data should be within 0.1ml, discard the abnormal data value)

V0: edta value consumed by the standard sample made of calcium chloride

By calculating the scale inhibition rate, it can be seen that the hyperbranched phosphorus-free scale inhibitor of this embodiment is better than the scale inhibition effect lacking any kind of raw material, and when the phosphate concentration reaches 50mg/L, it can still achieve a scale inhibition effect of 90%. above. 4. Anti-scaling effect for calcium silicate:

(1) Take 3 sets of clean 100ml volumetric flasks and add 1/3 of deionized water;

(2) Add 2.05ml 0.05mol/L calcium chloride solution to the 3 sets of volumetric flasks respectively (by analogy 4.15ml (240ppm calcium silicate), 6.2ml (360ppm calcium silicate));

(3) Add 5ppm, 10ppm, and 20ppm scale inhibitors to the 3 groups of volumetric flasks and make the blank group;

(4) Add 2.05ml 0.05mol/L sodium silicate solution to the 3 sets of volumetric flasks respectively (analogously 4.15ml (240ppm calcium silicate), 6.2ml (360ppm calcium silicate));

(5) Dilute the volume to 100ml with deionized water, shake it enough, transfer it to a pre-prepared container, and place it in an airtight container for 24 hours;

(6) Draw a standard curve in accordance with the standard GB/T 12149-2017 "Determination of Silicon in Industrial Circulating Cooling Water and Boiler Water". Using the measured absorbance as the ordinate and the mass concentration of silica (mg/L) as the abscissa, draw a standard curve or calculate a regression equation. The range of the calibration curve can also be adjusted according to the content of the analyte.

(7)

C2: Take three groups of solutions after adding the scale inhibitor to determine the average value of the concentration of silica (the difference between the three groups of data should be within 0.1ml, and discard the abnormal data values)

C1: Determine the average value of silica concentration without adding scale inhibitor solution (the difference between the three groups of data should be within 0.1ml, and discard the abnormal data value)

C0: Determine the average concentration of silica with a standard sample made of sodium silicate

By calculating the scale inhibition rate, it can be seen that the hyperbranched phosphorus-free scale inhibitor of this embodiment is better than the scale inhibition effect lacking any kind of raw material, and when the calcium silicate concentration reaches 360mg/L, it can still be used after adding a certain amount of medicament. It has an anti-scaling effect of more than 90%.

Example 2

In the reactor, control the temperature to 40-50℃, add water, graphene dispersion, cross-linking agent (hydroxyethyl acrylate), inorganic base, stir at low speed for 10-30min, and then drop it sequentially within 2-3 hours Add polyvinylamine (8000), potassium aspartate, ethylenediaminetetraacetic acid, and tricarboxylic acid (nitrilotriacetic acid) to the reactor and mix well to obtain a hyperbranched phosphorus-free scale inhibitor.

The mass ratio of polyvinylamine, aspartic acid and its analogs, ethylenediaminetetraacetic acid and its analogs is 2:5:1;

The mass of the water is 1.5 times the sum of the masses of polyvinylamine, aspartic acid and its analogues, ethylenediaminetetraacetic acid and its analogues;

The amount of the crosslinking agent is 0.8% of the weight of water;

The amount of the graphene dispersion is 1.5g/L water;

The amount of the tricarboxylic acid is 0.8% of the weight of water;

The amount of the inorganic base is 0.6mol/L water

The preparation method of the graphene dispersion is as follows: under normal temperature and pressure, add reducing agent and dispersant to the commercially available graphene oxide dispersion, and the graphene dispersion formed by the reduction reaction;

The mass ratio of the graphene oxide dispersion liquid: reducing agent: dispersing agent is 5:1:1;

The above reducing agent is sodium metabisulfite;

The above dispersant is sodium polyacrylate.

The solid content of the graphene dispersion liquid is between 0.4-0.7%, and the total oxygen content is between 5% and 7%;

The thickness of the upper graphene dispersion is about 1.68 μm, and the microplate size is about 1.2 μm.

The method of use is as follows: the dosage of 1-5ppm can achieve the purpose of scale inhibition.

Example 3

In the reactor, control the temperature to 40-50℃, add water, graphene dispersion, crosslinking agent (hydroxyethyl acrylate), inorganic potassium hydroxide, stir at low speed for 10-30min, then within 2-3 hours Polyvinylamine (12000), magnesium aspartate, dipotassium ethylenediaminetetraacetate, and tricarboxylic acid (nitrilotriacetic acid) were added dropwise to the reactor and mixed uniformly to obtain a hyperbranched phosphorus-free scale inhibitor.

The mass ratio of polyvinylamine, aspartic acid and its analogs, ethylenediaminetetraacetic acid and its analogs is 1:4:1;

The mass of the water is 1.5 times the sum of the masses of polyvinylamine, aspartic acid and its analogues, ethylenediaminetetraacetic acid and its analogues;

The amount of the crosslinking agent is 0.6% of the weight of water;

The amount of the graphene dispersion is 1.8 g/L water;

The amount of the tricarboxylic acid is 0.7% of the weight of the water;

The amount of the inorganic base is 0.7mol/L water

The preparation method of graphene dispersion is as follows: under normal temperature and pressure, add reducing agent and dispersant to commercially available graphene oxide dispersion, and form graphene dispersion through reduction reaction;

The mass ratio of the above graphene oxide dispersion: reducing agent: dispersing agent is 12:1:1;

The above reducing agent is sodium bisulfite;

The above dispersant is sodium polyacrylate.

The solid content of the graphene dispersion liquid is between 0.8-1%, and the total oxygen content is between 8% and 9%;

The thickness of the upper graphene dispersion is about 3.11 μm, and the microplate size is about 2.8 μm.

The method of use is as follows: the dosage of 1-5ppm can achieve the purpose of scale inhibition.

Example 4

In the reactor, control the temperature to 40-50℃, add water, graphene dispersion, crosslinking agent (hydroxyethyl acrylate), sodium hydroxide, stir at low speed for 10-30min, and then sequentially within 2-3 hours Add polyvinylamine (10000), sodium aspartate, sodium ethylenediaminetetraacetate, and tricarboxylic acid (citric acid) to the reactor and mix uniformly to obtain a hyperbranched phosphorus-free scale inhibitor.

The mass ratio of polyvinylamine, aspartic acid and its analogs, ethylenediaminetetraacetic acid and its analogs is 1.5:4.5:1;

The mass of the water is 1.2 times the sum of the masses of polyvinylamine, aspartic acid and its analogues, ethylenediaminetetraacetic acid and its analogues;

The amount of the crosslinking agent is 0.6% of the weight of water;

The amount of the graphene dispersion (same as in Example 1) is 1.8 g/L water;

The amount of the tricarboxylic acid is 0.5% of the weight of water;

The amount of the inorganic base is 0.8mol/L water

The method of use is as follows: the dosage of 1-5ppm can achieve the purpose of scale inhibition.

Claims (10)

A hyperbranched phosphorus-free scale inhibitor, characterized in that it is composed of polyvinylamine, aspartic acid and its analogues, ethylenediaminetetraacetic acid and its analogues, tricarboxylic acid, crosslinking agent, inorganic alkali, Manufactured from graphene dispersion and water: Wherein, the mass ratio of the polyvinylamine, aspartic acid and its analogs, ethylenediaminetetraacetic acid and its analogs is 1-2:4-5:1; The mass of the water is 1 to 1.5 times the sum of the masses of polyvinylamine, aspartic acid and its analogs, ethylenediaminetetraacetic acid and its analogs; The amount of the crosslinking agent is 0.5-0.8% of the weight of water; The amount of the graphene dispersion is 1.5-2g/L water; The amount of the tricarboxylic acid is 0.5-0.8% of the weight of water; The amount of the inorganic base is 0.6-0.8 mol/L water. The hyperbranched phosphorus-free scale inhibitor of claim 1, wherein: The aspartic acid and its analogs are selected from any one or several compounds of aspartic acid, alkali metal salt of aspartic acid or alkaline earth metal salt. The hyperbranched phosphorus-free scale inhibitor of claim 1, wherein: The ethylenediaminetetraacetic acid and its analogs are selected from one or more of ethylenediaminetetraacetic acid, alkali metal salts or alkaline earth metal salts of ethylenediaminetetraacetic acid. The hyperbranched phosphorus-free scale inhibitor of claim 1, wherein: The tricarboxylic acid is selected from any one or two of citric acid and nitrilotriacetic acid. The hyperbranched phosphorus-free scale inhibitor of claim 1, wherein: The crosslinking agent is any one of hydroxyethyl acrylate and triethanolamine. The hyperbranched phosphorus-free scale inhibitor of claim 1, wherein: The inorganic base is selected from one or more of alkali metal salts or alkaline earth metal hydroxides. The hyperbranched phosphorus-free scale inhibitor of claim 1, wherein: The preparation method of the graphene dispersion is: adding a reducing agent and a dispersing agent to the graphene oxide dispersion under normal temperature and pressure, and the graphene dispersion formed by a reduction reaction; Wherein, the mass ratio of the graphene oxide dispersion: reducing agent: dispersing agent is 3-30:1:1; The solid content of the graphene dispersion is 0.4-0.5%, and the total oxygen content is 3%-5%. The hyperbranched phosphorus-free scale inhibitor of claim 7, wherein: The thickness of the graphene dispersion is 0.55 to 3.74 μm, and the microplate size is 0.5 to 3 μm. The hyperbranched phosphorus-free scale inhibitor according to claim 1, wherein the specific preparation method is: In the reactor, control the temperature to 40-50℃, add water, graphene dispersion, cross-linking agent, inorganic alkali, stir at low speed for 10-30 minutes, then add polyvinylamine, aspartic acid and the like in sequence , Ethylenediaminetetraacetic acid and its analogues, and tricarboxylic acid are mixed uniformly in the reactor to obtain the hyperbranched phosphorus-free scale inhibitor; Wherein, the total dropping time of the polyethyleneimine, aspartic acid and its analogs, ethylenediaminetetraacetic acid and its analogs is controlled within 2 to 3 hours. The hyperbranched phosphorus-free scale inhibitor of claim 1, wherein: The dosage of the phosphorus-free scale inhibitor is controlled within 1 to 5 ppm.