CN109748401B - Method for treating circulating cooling water - Google Patents
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Abstract
The invention relates to the field of corrosion and scale inhibition of circulating cooling water, in particular to a treatment method of circulating cooling water, which comprises the steps of contacting the circulating cooling water with a phosphorus-free composite corrosion and scale inhibitor; the phosphorus-free composite corrosion and scale inhibitor contains a compound A, a sulfonate copolymer, a zinc salt and an optional copper corrosion inhibitor, wherein the compound A is hydrolyzed polymaleic anhydride and/or a maleic acid-acrylic acid copolymer; the circulating cooling water is medium-hardness water with the sum of calcium hardness and total alkalinity being more than 100mg/L and less than 900 mg/L; the pH value of the circulating cooling water is 7.9-8.5. The composite corrosion and scale inhibitor has excellent corrosion inhibition performance and can well stabilize Zn in water2+Ability to and CaCO3The corrosion and scale inhibitor has the advantages of less components and low dosage, and is particularly suitable for the treatment of circulating cooling water with the sum of calcium hardness and total alkalinity of more than 100mg/L and less than 900 mg/L. And the composite corrosion and scale inhibitor does not contain phosphorus, and is green and environment-friendly.
Description
Technical Field
The invention relates to the field of corrosion and scale inhibition of circulating cooling water, in particular to a method for treating the circulating cooling water by adopting phosphorus-free composite corrosion and scale inhibition.
Background
The supply and demand conditions of the circulating cooling water have great influence on water use, drainage and water saving of the whole industrial enterprise, but the problem of candle corrosion and scaling of cooling facilities in the circulating cooling water system is brought along. In a cooling circulating water system, adding a corrosion and scale inhibitor is one of the most important methods for preventing the circulating cooling water from scaling. In addition, in recent years, the environmental protection attention of China is continuously improved, and particularly for industrial enterprises, the total phosphorus emission (counted by P) is less than or equal to 1.0mg/L, the total zinc is less than or equal to 2.0mg/L and the chemical oxygen consumption is less than or equal to 60mg/L in the discharge standard GB31570-2015 of pollutants for the petrochemical industry; the total phosphorus, the chemical oxygen consumption and the total zinc of a newly built plant are regulated to be less than or equal to 0.3mg/L, 30mg/L and 1.0mg/L in the discharge standard DB11/890-2012 of water pollutants of urban sewage treatment plants. Therefore, the control of the phosphorus content, the chemical oxygen consumption and the total zinc content of the corrosion and scale inhibitor is an important link for reducing pollution emission, and the phosphorus-free greening of the corrosion and scale inhibitor is not slow. The development and application of the polyepoxysuccinic acid become the development direction of a phosphorus-free biodegradable green corrosion and scale inhibitor, the polyepoxysuccinic acid has the double functions of corrosion inhibition and scale inhibition, good thermal stability, no phosphorus and no nitrogen, but in practical application, the polyepoxysuccinic acid is alkaline, is easy to precipitate and not easy to mix when being compounded with other corrosion and scale inhibitors, and is inconvenient in practical application. Meanwhile, in the present day that water resources are increasingly deficient, low hard water, soft water, demineralized water, sewage reuse water and the like exist in many cases in the aspect of water quality, and the superiority of the water treatment agent in the aspect of corrosion inhibition is tested more seriously.
Therefore, the corrosion and scale inhibitor which is phosphorus-free, green, strong in applicability, few in components and low in use concentration is urgently needed to be developed.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a method for treating circulating cooling water by adopting phosphorus-free composite corrosion and scale inhibitor, and the composite corrosion and scale inhibitor used in the method has the characteristics of few components, no phosphorus, low working concentration and environmental protection.
In order to achieve the above object, the present invention provides a method for treating recirculated cooling water, which comprises contacting recirculated cooling water with a phosphorus-free composite corrosion and scale inhibitor;
the phosphorus-free composite corrosion and scale inhibitor contains a compound A, a sulfonate copolymer, a zinc salt and an optional copper corrosion inhibitor, wherein the compound A is hydrolyzed polymaleic anhydride and/or a maleic acid-acrylic acid copolymer;
wherein the circulating cooling water is medium-hardness water with the sum of calcium hardness and total alkalinity being more than 100mg/L and less than 900 mg/L; the pH value of the circulating cooling water is 7.9-8.5.
Preferably, the sulfonate copolymer is a disulfonate copolymer or a trisulfonate copolymer.
Preferably, the copper corrosion inhibitor is an azole compound.
Preferably, the non-phosphorus composite corrosion and scale inhibitor further contains water in an amount of 30 to 80 parts by weight based on 100 parts by weight of the non-phosphorus composite corrosion and scale inhibitor.
The composite corrosion and scale inhibitor used in the circulating cooling water treatment method has excellent corrosion inhibition performance and can well stabilize Zn in water2+Ability to and CaCO3The scale inhibitor has the advantages of scale function, less components and lower dosage, and is particularly suitable for the circulating cooling water treatment of medium-hard water quality, such as the circulating cooling water treatment of medium-hard water with the sum of calcium hardness and total alkalinity more than 100mg/L and less than 900 mg/L. In addition, the composite corrosion and scale inhibitor used in the method does not contain phosphorus, and belongs to an environment-friendly corrosion and scale inhibitor.
Detailed Description
The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.
The first aspect of the invention provides a method for treating circulating cooling water, which comprises the steps of contacting the circulating cooling water with a phosphorus-free composite corrosion and scale inhibitor;
the phosphorus-free composite corrosion and scale inhibitor contains a compound A, a sulfonate copolymer, a zinc salt and an optional copper corrosion inhibitor, wherein the compound A is hydrolyzed polymaleic anhydride and/or a maleic acid-acrylic acid copolymer;
wherein the circulating cooling water is medium-hardness water with the sum of calcium hardness and total alkalinity being more than 100mg/L and less than 900 mg/L; the pH value of the circulating cooling water is 7.9-8.5.
Preferably, the phosphorus-free composite corrosion and scale inhibitor consists of a compound A, a sulfonate copolymer, a zinc salt and an optional copper corrosion inhibitor.
The inventor of the invention finds that the hydrolytic polymaleic anhydride and/or maleic acid-acrylic acid copolymer and zinc salt can play a role in corrosion inhibition, and the sulfonate copolymer can play a role in stabilizing the zinc salt in circulating water and preventing CaCO3Deposition of scale and suspended matter. The hydrolytic polymaleic anhydride and/or maleic acid-acrylic acid copolymer is matched with the sulfonate copolymer, the zinc salt and the optional copper corrosion inhibitor for use, so that the working concentration of the hydrolytic polymaleic anhydride and/or maleic acid-acrylic acid copolymer can be reduced while the corrosion and scale inhibition effects are ensured. Therefore, the green environment-friendly corrosion and scale inhibitor is developed and used for treating medium-hardness water with the sum of calcium hardness and total alkalinity being more than 100mg/L and less than 900mg/L and the pH value of 7.9-8.5 (natural operation pH value), and a good effect is achieved.
In the invention, the hydrolyzed polymaleic anhydride (HPMA) is orange viscous liquid, the relative density is 1.2(20 ℃), the general relative molecular weight is 400-800, the average relative molecular weight is about 600, and the hydrolyzed polymaleic anhydride is acidic, can be ionized, can be dissolved in water, and has the decomposition temperature of over 330 ℃.
In the present invention, the object of the present invention can be achieved by using the above-mentioned components in combination and applying them to the treatment of medium hardness water as described above, and the content of each component is not particularly required. Preferably, in order to further improve the corrosion and scale inhibition effect, the content of the sulfonate copolymer is 18 to 600 parts by weight relative to 100 parts by weight of the compound A, and the zinc salt is Zn2+The calculated content is 3-125 weight portions, and the content of the optional copper corrosion inhibitor is 3-75 weight portions; further preferably, the sulfonate copolymer is contained in an amount of 30 to 270 parts by weight and the zinc salt is Zn, relative to 100 parts by weight of the compound A2+The content is 4-40 weight portions, and the content of the optional copper corrosion inhibitor is 5-50 weight portions.
The type of the sulfonate copolymer is not particularly limited in the present invention, and in order to further improve the corrosion and scale inhibition effect, it is preferable that the sulfonate copolymer is a disulfonate copolymer or a trisulfonate copolymer, and it is further preferable that the sulfonate copolymer is selected from the group consisting of an acrylic acid/2-acrylamide-2-methylpropanesulfonic acid copolymer, an acrylic acid/2-acrylamide-2-methylpropanesulfonic acid/hydroxypropyl acrylate copolymer, an acrylic acid/acrylate/sulfonate copolymer, a carboxylate/sulfonate/nonionic copolymer, an acrylic acid/styrene sulfonic acid copolymer, an acrylate/styrene sulfonic acid copolymer, an acrylic acid/allyl sulfonic acid copolymer, an acrylic acid/vinyl sulfonic acid copolymer, an acrylic acid/2-methyl-2' -acrylamidopropanesulfonic acid copolymer, a salt of a carboxylic acid/sulfonic acid/nonionic copolymer, an acrylic acid/, At least one of acrylic acid/acrylamide/2-methyl-2 ' -acrylamidopropanesulfonic acid copolymer, acrylic acid/maleic acid/2-methyl-2 ' -acrylamidopropanesulfonic acid copolymer, and acrylic acid/acrylate-2-methyl-2 ' -acrylamidopropanesulfonic acid copolymer.
In the invention. The zinc salt can be water-soluble zinc salt with corrosion inhibition performance (the solubility is more than or equal to 1g/100g water at 20 ℃) which is common in the field, and the type and the content of the zinc salt are not particularly limited. Preferably, the zinc salt is zinc sulfate and/or zinc chloride.
In one embodiment of the invention, the non-phosphorus composite corrosion and scale inhibitor contains a copper corrosion inhibitor. The copper corrosion inhibitor can be various heterocyclic compounds with copper corrosion inhibition performance commonly seen in the field. The kind and content thereof are not particularly limited. Preferably, the copper corrosion inhibitor is an azole corrosion inhibitor, preferably at least one selected from benzotriazole, methylbenzotriazole and mercaptobenzotriazol.
The components of the phosphorus-free composite corrosion and scale inhibitor used in the method can be stored independently or in a mixed manner.
In a preferred embodiment, the phosphorus-free composite corrosion and scale inhibitor used in the method of the invention consists of the components described above. The individual components are commercially available and may be provided in the form of a solution, but the contents or weights referred to in the present invention are each in terms of an effective concentration (content or weight of solute).
According to a specific embodiment of the invention, the phosphorus-free composite corrosion and scale inhibitor used in the method also contains water, and the components of the phosphorus-free corrosion and scale inhibitor can be dissolved in water according to a proportion to prepare a corrosion and scale inhibitor solution for standby application, or can be matched with water when in use. Preferably, the water content is 30 to 80 parts by weight, more preferably 40 to 70 parts by weight, based on 100 parts by weight of the phosphorus-free composite corrosion and scale inhibitor.
In the treatment method of the circulating cooling water, the dosage of the non-phosphorus composite corrosion and scale inhibitor is not particularly limited as long as the corrosion and scale inhibitor can play a corrosion and scale inhibiting effect on cooling equipment. Preferably, the composite corrosion and scale inhibitor is used in an amount such that the concentration of the compound A is 2-16mg/L (for example, 2mg/L, 4mg/L, 6mg/L, 8mg/L, 10mg/L, 12mg/L, 14mg/L, 16mg/L), the concentration of the sulfonate copolymer is 3-12mg/L (for example, 3mg/L, 4mg/L, 6mg/L, 8mg/L, 10mg/L, 12mg/L), and Zn is added to the circulating cooling water2+The concentration of zinc salt is 0.5-2.5mg/L (e.g., can be 0.5mg/L, 0.8mg/L, 1.0mg/L, 1.2mg/L, 1.5mg/L, 1.8mg/L, 2.0mg/L, 2.3mg/L, 2.5mg/L), and the concentration of optional copper corrosion inhibitor is 0.5-1.5mg/L (e.g., can be 0.5mg/L, 0.8mg/L, 1.0mg/L, 1.2mg/L, 1.5 mg/L).
In the circulating cooling water treatment method provided by the invention, the components of the phosphorus-free corrosion and scale inhibitor can cooperate with each other, so that the corrosivity of medium-hardness water can be effectively relieved under the condition of low consumption of the components, and Zn in water can be well stabilized2+Ability of (C) and resistance of CaCO3The scale effect is obvious. Therefore, the phosphorus-free composite corrosion and scale inhibitor can obtain excellent corrosion and scale inhibition effects without using phosphorus-containing components.
In practical application, the phosphorus-free composite corrosion and scale inhibitor can be prepared before use, for example, the components are mixed according to the formula and then added into circulating cooling water; the components can also be added directly to the recirculating cooling water in accordance with the foregoing formulation without a mixing step. When directly added, the order of addition of the respective components is not particularly limited. In addition, the components can be mixed with water to be fully dissolved and then added into circulating cooling water.
In order to control the growth of microorganisms in the circulating cooling water, a bactericide can be added into the circulating cooling water when the circulating cooling water is treated, the bactericide can be added simultaneously or not simultaneously with the components of the phosphorus-free composite corrosion and scale inhibitor, and the type and the using amount of the bactericide used are well known to those skilled in the art and are not described again.
The present invention will be described in detail below by way of examples.
In the following examples and comparative examples,
hydrolyzed polymaleic anhydride (HPMA), maleic acid-acrylic acid copolymer (MA/AA), acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer (AA/AMPS), acrylic acid/acrylic ester/sulfonate copolymer (TH-2000), acrylic acid/vinylsulfonic acid copolymer, acrylic acid/2-methyl-2 '-acrylamidopropanesulfonic acid copolymer, acrylic acid/2-acrylamide-2-methylpropanesulfonic acid/hydroxypropyl acrylate copolymer (AA/AMPS/HPA), acrylic acid/acrylamide/2-methyl-2' -acrylamidopropanesulfonic acid copolymer, acrylic ester/styrenesulfonic acid copolymer, acrylic acid/styrene sulfonic acid copolymer, acrylic acid/, Acrylic acid/allyl sulfonic acid copolymer, carboxylate-sulfonate-nonionic copolymer (TH-3100), acrylic acid/acrylate-2-methyl-2' -acrylamidopropanesulfonic acid copolymer, were all available from Tai and Water treatment, Inc., Shandong province.
The water quality of the test water is shown in Table 1. Wherein Ca2+And total alkalinity are all as CaCO3In which Ca is counted2+Representing calcium hardness. The water quality determination method refers to the analysis and test method of cooling water (1993, published by the information center of the general petrochemical plant in Anqing) compiled by the Ministry of production and development of the general petrochemical company of China.
TABLE 1
| Quality of water | Ca2+(mg/l) | Total alkalinity (mg/l) | Cl-(mg/l) | PH | Conductivity (μ s/cm) |
| Test Water 1 | 430 | 450 | 121 | 8.2 | 1320 |
| Test Water 2 | 140 | 165 | 34 | 7.9 | 356 |
Determination of calcium carbonate Scale inhibition Properties
The calcium carbonate scale inhibition performance test is to determine the scale inhibition performance of the water treatment medicament composition according to the method of GB/T16632-2008 'determination of scale inhibition performance of water treatment agent-calcium carbonate deposition method'. The specific process is as follows:
to Ca2+Adding the reagent into test water with the concentration of 600mg/L and the alkalinity of 600mg/L, preserving the heat for 10 hours in a constant-temperature water bath at the temperature of 80 +/-1 ℃, sampling and analyzing the residual Ca in the water after cooling2+At the same time asBlank samples are made, and the scale inhibition rate is calculated.
The scale inhibition rate calculation formula is as follows:
c: actually measured Ca2+Concentration of (2)
C0: ca of blank2+Concentration of (2)
Determination of Corrosion inhibition Performance
The rotating hanging piece corrosion test is to measure the corrosion inhibition performance of the water treatment medicament composition according to the method of GB/T18175-. The specific process is as follows:
fixing a No. 20 high-quality carbon steel test piece on a coupon instrument, putting the test piece into test water 1 added with a corrosion and scale inhibitor, keeping the temperature at 45 +/-1 ℃, keeping the rotating speed at 75rpm for 72 hours, recording the weight of the test piece before and after the test, and calculating the average corrosion speed.
The average corrosion rate is calculated by the formula: f ═ C × Δ W/a × T × ρ
C: the constants were calculated, and when mm/a (mm/year) is used, C is 8.76 × 107
Δ W: corrosion weight loss of test piece (gram)
A: area of test piece (cm)2)
T: corrosion test time (hours)
ρ: density of test piece material (kg/m)3)
Dynamic simulation test
The dynamic simulation test is to determine the effect of the water treatment medicament composition of the invention on simulating the water treatment of a circulating water field according to the method of HG/T2160-2008 cooling water dynamic simulation test method. The specific process is as follows:
in order to simulate the circulating water field condition, a dynamic simulation test is carried out. Annual corrosion rate B (mm/a) and adhesion rate mcm (mg/cm)3) The evaluation is carried out according to the following specific calculation formula:
the annual corrosion rate is calculated by the formula:
K：3.65ⅹ106
g: mass (g) reduced after tube corrosion
T: time of test run (d)
A: corrosion area of test tube (cm)2)
D: metal density (g/cm)3)
Adhesion rate calculation formula: mcm is 7.2 × 105(W1-W2)/A·t
W1: weight of test tube after test, g;
W2: weight of tube after washing, g;
a: internal surface area, cm, of test tube before test2；
t: test time, h.
Stabilization of zinc salt properties
Preparing Ca from distilled water2+The concentration is 250 mg.L-1Alkalinity of 250 mg.L-1，Zn2+Is 5 mg.L-1And 1g/L of sodium tetraborate as test water, adding a phosphorus-free corrosion and scale inhibitor, standing for 10 hours in a constant-temperature water bath at the temperature of 80 +/-1 ℃, and sampling and analyzing residual Zn in the water2+And (4) simultaneously making blank samples, and calculating the zinc resistance rate.
The zinc resistance rate calculation formula is as follows: the zinc resistance rate is (C-C0)/(C1-C0). times.100%
C: actually measured Zn2+Concentration of (2)
C0: zn of blank2+Concentration of (2)
C1: zn in raw water2+Concentration of (2)
The higher the zinc inhibition rate, the better the stability of the zinc salt in water, which indicates that the performance of stabilizing the zinc salt is better.
Total phosphorus determination
See HG/T3540 & 2011 determination of total phosphate content in industrial circulating cooling water
Chemical oxygen consumption determination
See DL/T502.23-2006 section 23 of method for steam analysis in thermal power plants: in the determination of chemical oxygen consumption (potassium dichromate method), the solution with COD less than or equal to 30mg/L can be tested by 0.025mol/L potassium dichromate solution.
Example 1
This example is used to illustrate the corrosion and scale inhibition performance of the phosphorus-free corrosion and scale inhibitor provided by the present invention
Weighing 8.0g of HPMA with effective content of 50%, 25.0g of acrylic acid/styrene sulfonic acid copolymer with active component of 30%, and 4.0g of ZnSO4·7H2And O, adding 63.0g of water, and shaking up to obtain 100.0g of the phosphorus-free corrosion and scale inhibitor 1 required to be prepared. The prepared phosphorus-free corrosion and scale inhibitor 1 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor 1 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Example 2
This example is used to illustrate the corrosion and scale inhibition performance of the phosphorus-free corrosion and scale inhibitor provided by the present invention
16.0g of HPMA with an effective content of 50%, 8.3g of an acrylate/styrenesulfonic acid copolymer with an active ingredient of 30%, 11.7g of an acrylic acid/allylsulfonic acid copolymer with an active ingredient of 30%, 4.4g of ZnSO were weighed out4·7H2And O, adding 59.6g of water, and shaking up to obtain 100.0g of the phosphorus-free corrosion and scale inhibitor 2 required to be prepared. The prepared phosphorus-free corrosion and scale inhibitor 2 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor 2 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Example 3
This example is used to illustrate the corrosion and scale inhibition performance of the phosphorus-free corrosion and scale inhibitor provided by the present invention
Weighing 20.0g of HPMA with effective content of 50%, 18.3g of AA/AMPS with active component of 30%, and 1.7g of ZnCl2And adding 60.0g of water, and shaking uniformly to obtain 100.0g of the phosphorus-free corrosion and scale inhibitor 3 required to be prepared. The prepared phosphorus-free corrosion and scale inhibitor 3 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor 3 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Example 4
This example is used to illustrate the corrosion and scale inhibition performance of the phosphorus-free corrosion and scale inhibitor provided by the present invention
24.0g of HPMA with an effective content of 50%, 26.7g of an acrylic acid/acrylate/sulfonate copolymer (TH-2000) with an active component of 30% and 5.3g of ZnSO were weighed out4·7H2And O, adding 44.0g of water, and shaking up to obtain 100.0g of the phosphorus-free corrosion and scale inhibitor 4 required to be prepared. The prepared phosphorus-free corrosion and scale inhibitor 4 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor 4 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Example 5
This example is used to illustrate the corrosion and scale inhibition performance of the phosphorus-free corrosion and scale inhibitor provided by the present invention
Preparation of phosphorus-free Corrosion and Scale inhibitor 5 was carried out as in example 4, except that ZnSO4·7H2The dosage of the O is 1.8g, and the total amount of the phosphorus-free corrosion and scale inhibitor is complemented to 100.0g by water. The prepared phosphorus-free corrosion and scale inhibitor 5 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor 5 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Example 6
This example is used to illustrate the corrosion and scale inhibition performance of the phosphorus-free corrosion and scale inhibitor provided by the present invention
The preparation of the phosphorus-free corrosion and scale inhibitor 6 was carried out as in example 4, except that the amount of the 30% acrylic acid-acrylate-sulfonate copolymer was 5.0g, and the total amount of the phosphorus-free corrosion and scale inhibitor was made up to 100.0g with water. The prepared phosphorus-free corrosion and scale inhibitor 6 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor 6 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Example 7
This example is used to illustrate the corrosion and scale inhibition performance of the phosphorus-free corrosion and scale inhibitor provided by the present invention
31.0g of HPMA with an effective content of 50%, 21.7g of an acrylic acid/vinylsulfonic acid copolymer with an active component of 30% and 3.1g of ZnSO were weighed out4·7H2And O, adding 44.2g of water, and shaking up to obtain 100.0g of the phosphorus-free corrosion and scale inhibitor 7 required to be prepared. The prepared phosphorus-free corrosion and scale inhibitor 7 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor 7 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Example 8
This example is used to illustrate the corrosion and scale inhibition performance of the phosphorus-free corrosion and scale inhibitor provided by the present invention
Weighing 6.0g of MA/AA with effective content of 50%, 26.7g of acrylic acid/2-methyl-2' -acrylamidopropanesulfonic acid copolymer with active component of 30%, and 4.9g of ZnSO4·7H2And O, adding 62.4g of water, and shaking up to obtain 100.0g of the phosphorus-free corrosion and scale inhibitor 8 required to be prepared. The prepared phosphorus-free corrosion and scale inhibitor 8 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor 8 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Example 9
This example is used to illustrate the corrosion and scale inhibition performance of the phosphorus-free corrosion and scale inhibitor provided by the present invention
Weighing 12.0g of MA/AA with effective content of 50%, 30.0g of acrylic acid/acrylamide/2-methyl-2' -acrylamidopropanesulfonic acid copolymer with active component of 30%, and 5.3g of ZnSO4·7H2And O, adding 52.7g of water, and shaking up to obtain 100.0g of the phosphorus-free corrosion and scale inhibitor 9 required to be prepared. The prepared phosphorus-free corrosion and scale inhibitor 9 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor 9 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Example 10
This example is used to illustrate the corrosion and scale inhibition performance of the phosphorus-free corrosion and scale inhibitor provided by the present invention
Weighing18.0g of MA/AA with an effective content of 50%, 18.0g of AA/AMPS/HPA with an active component of 30%, and 3.5g of ZnSO4·7H2And O, adding 60.5g of water, and shaking up to obtain 100.0g of the phosphorus-free corrosion and scale inhibitor 10 required to be prepared. The prepared phosphorus-free corrosion and scale inhibitor 10 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor 10 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Example 11
This example is used to illustrate the corrosion and scale inhibition performance of the phosphorus-free corrosion and scale inhibitor provided by the present invention
Weighing 24.0g of MA/AA with effective content of 50%, 10.0g of TH-3100 with active component of 45%, and 2.6g of ZnSO4·7H2And O, adding 63.4g of water, and shaking up to obtain 100.0g of the phosphorus-free corrosion and scale inhibitor 11 required to be prepared. The prepared phosphorus-free corrosion and scale inhibitor 11 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor 11 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Example 12
This example is used to illustrate the corrosion and scale inhibition performance of the phosphorus-free corrosion and scale inhibitor provided by the present invention
Weighing 18.0g of HPMA with effective content of 50%, 9.0g of MA/AA with effective content of 50%, 13.3g of acrylic acid/acrylate/2-methyl-2' -acrylamidopropanesulfonic acid copolymer with active component of 30%, and 3.1g of ZnSO4·7H2And O, adding 56.6g of water, and shaking up to obtain 100.0g of the phosphorus-free corrosion and scale inhibitor 12 required to be prepared. The prepared phosphorus-free corrosion and scale inhibitor 12 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor 12 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Example 13
This example is used to illustrate the corrosion and scale inhibition performance of the phosphorus-free corrosion and scale inhibitor provided by the present invention
Weighing 4.0g of HPMA with effective content of 50%, 12.0g of MA/AA with effective content of 50%, and 23.3g of active component30% acrylic acid/acrylic ester/sulfonate copolymer, 4.9g ZnSO4·7H2And O, adding 55.8g of water, and shaking up to obtain 100.0g of the phosphorus-free corrosion and scale inhibitor 13 required to be prepared. The prepared phosphorus-free corrosion and scale inhibitor 13 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor 13 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Example 14
This example is used to illustrate the corrosion and scale inhibition performance of the phosphorus-free corrosion and scale inhibitor provided by the present invention
Weighing 7.0g of HPMA with effective content of 50%, 7.0g of MA/AA with effective content of 50%, 20.0g of AA/AMPS/HPA with active component of 30%, 4.4g of TH-2000 with active component of 45%, and 4.9g of ZnCl2And adding 56.7g of water, and shaking up to obtain 100.0g of the phosphorus-free corrosion and scale inhibitor 14 required to be prepared. The prepared phosphorus-free corrosion and scale inhibitor 14 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor 14 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Example 15
This example is used to illustrate the corrosion and scale inhibition performance of the phosphorus-free corrosion and scale inhibitor provided by the present invention
Weighing 16.0g of HPMA with effective content of 50%, 4.0g of MA/AA with effective content of 50%, 3.3g of TH-2000 with active component of 45%, 5.6g of TH-3100 with active component of 45%, and 2.9g of ZnSO4·7H2And adding 68.2g of water into the mixture, and shaking the mixture evenly to obtain 100.0g of the phosphorus-free corrosion and scale inhibitor 15 required to be prepared. The prepared phosphorus-free corrosion and scale inhibitor 15 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor 15 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Comparative example 1
The comparative example is used for explaining the corrosion and scale inhibition performance of the reference phosphorus-free corrosion and scale inhibitor
The formulation of the phosphorus-free corrosion and scale inhibitor D1 was carried out as in example 4, except that no zinc salt and no sulfonate were addedAnd (3) adding water to make up the total amount of the phosphorus-free corrosion and scale inhibitor to 100.0 g. The prepared phosphorus-free corrosion and scale inhibitor D1 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor D1 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Comparative example 2
The comparative example is used for explaining the corrosion and scale inhibition performance of the reference phosphorus-free corrosion and scale inhibitor
The formulation of the phosphorus-free corrosion and scale inhibitor D2 was carried out as in example 4, except that the total amount of the phosphorus-free corrosion and scale inhibitor was made up to 100.0g with water without addition of zinc salts. The prepared phosphorus-free corrosion and scale inhibitor D2 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor D2 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Comparative example 3
The comparative example is used for explaining the corrosion and scale inhibition performance of the reference phosphorus-free corrosion and scale inhibitor
Formulation of the phosphorus-free corrosion and scale inhibitor D3 was carried out as in example 4, except that HPMA was replaced with an equal amount of polyaspartic acid. The prepared phosphorus-free corrosion and scale inhibitor D3 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor D3 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
Comparative example 4
The comparative example is used for explaining the corrosion and scale inhibition performance of the reference phosphorus-free corrosion and scale inhibitor
Formulation of the phosphorus-free corrosion and scale inhibitor D4 was carried out as in example 4, except that HPMA was replaced with an equal amount of copolymer of maleic acid and acrylamide. The prepared phosphorus-free corrosion and scale inhibitor D4 is added into test water according to the concentration of 100mg/L, and CaCO inhibition of the phosphorus-free corrosion and scale inhibitor D4 is measured according to the method3The scale formation rate, corrosion rate and zinc inhibition rate are shown in Table 2.
TABLE 2
As can be seen from the data in Table 2, the phosphorus-free composite corrosion and scale inhibitor used in the method has good comprehensive performance and good CaCO inhibition performance3Scale performance, corrosion inhibition performance and Zn stabilization in water2+The ability of the cell to perform.
Simulation experiment 1
To simulate the field, dynamic simulation tests were performed. The dynamic simulation test method is carried out according to the chemical industry standard HG/T2160-2008 of the people's republic of China, and the control parameters are as follows:
water quality: experimental Water 2 in Table 1
The concentration multiple is controlled by calcium hardness and total alkalinity value:
concentrating the A tower: more than 750mg/L and less than 900mg/L
And (4) concentrating the tower B: more than 750mg/L and less than 900mg/L
Flow rate: 1.0m/s
Medicament: tower A: comparative example 2 non-phosphorus composite corrosion and scale inhibitor D2
Tower B: non-phosphorus composite corrosion and scale inhibitor 4 of example 4
Inlet temperature: temperature difference of 32. + -. 1 ℃: 10 deg.C
The corrosion rate and tube adhesion rate are shown in table 3.
The results of the water quality index measured after the dynamic simulation test are shown in Table 4.
TABLE 3
TABLE 4
The corrosion speed of the carbon steel pipe wall of the open system is less than or equal to 0.075mm/a as specified in national standard GB 50050-2007 design Specification for Industrial circulating Cooling Water treatment 3.1.6; in the cooling water analysis and test method compiled by the production department and the development department of the general company of petrochemical industry, the laboratory small simulation test method stipulates that the corrosion speed of carbon steel is in a good grade between 0 and 0.028mm/a, in a good grade between 0.028 and 0.056mm/a and in an allowable grade between 0.056 and 0.070 mm/a; the adhesion speed is of the order of "good" at 0-6mcm, of "good" at 6-15mcm and of "permissible" at 15-20 mcm.
Therefore, when the sum of the calcium hardness and the total alkalinity is less than 900mg/L, the corrosion rate of the test tube is 0.020mm/a, the corrosion rate reaches the 'good' standard of the middle petrochemical industry, the adhesion rate is 7.6 mm, the 'good' standard is reached, and the corrosion and scale inhibition effects of the non-phosphorus composite scale and corrosion inhibitor are better than those of the formula of the comparative example. And the results of measuring the total phosphorus and COD of the circulating water after 15 days of operation show that the total phosphorus is almost absent, the COD value is lower, and the total phosphorus and the COD value meet the requirements in the discharge standard GB31570-2015 of pollutants for the petrochemical industry, namely the total phosphorus discharge (measured by P) is less than or equal to 1.0mg/L, and the chemical oxygen consumption is less than or equal to 60 mg/L.
The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.
Claims (13)
1. A treatment method of circulating cooling water is characterized by comprising the steps of contacting the circulating cooling water with a phosphorus-free composite corrosion and scale inhibitor;
the phosphorus-free composite corrosion and scale inhibitor consists of a compound A, a sulfonate copolymer and a zinc salt, wherein the compound A is hydrolyzed polymaleic anhydride and/or a maleic acid-acrylic acid copolymer;
wherein the circulating cooling water is medium-hardness water with the sum of calcium hardness and total alkalinity being more than 100mg/L and less than 900 mg/L; the pH value of the circulating cooling water is 7.9-8.5;
wherein the sulfonate copolymer is contained in an amount of 30 to 270 parts by weight and the zinc salt is Zn based on 100 parts by weight of the compound A2+The content is 4-40 weight portions.
2. The method of claim 1 wherein the sulfonate copolymer is a disulfonate copolymer or a trisulfonate copolymer.
3. The method of claim 2, wherein the sulfonate copolymer is selected from the group consisting of acrylic acid/2-acrylamido-2-methylpropanesulfonic acid copolymer, acrylic acid/2-acrylamido-2-methylpropanesulfonic acid/hydroxypropyl acrylate copolymer, acrylic acid/acrylate/sulfonate copolymer, carboxylate/sulfonate/nonionic copolymer, acrylic acid/styrenesulfonic acid copolymer, acrylate/styrenesulfonic acid copolymer, acrylic acid/allylsulfonic acid copolymer, acrylic acid/vinylsulfonic acid copolymer, acrylic acid/2-methyl-2 '-acrylamidopropanesulfonic acid copolymer, acrylic acid/acrylamide/2-methyl-2' -acrylamidopropanesulfonic acid copolymer, and mixtures thereof, At least one of acrylic acid/maleic acid/2-methyl-2 '-acrylamidopropanesulfonic acid copolymer and acrylic acid/acrylate-2-methyl-2' -acrylamidopropanesulfonic acid copolymer.
4. The method according to any one of claims 1-3, wherein the zinc salt is zinc sulphate and/or zinc chloride.
5. A treatment method of circulating cooling water is characterized by comprising the steps of contacting the circulating cooling water with a phosphorus-free composite corrosion and scale inhibitor;
the phosphorus-free composite corrosion and scale inhibitor consists of a compound A, a sulfonate copolymer, a zinc salt and a copper corrosion inhibitor, wherein the compound A is hydrolyzed polymaleic anhydride and/or a maleic acid-acrylic acid copolymer;
wherein the circulating cooling water is medium-hardness water with the sum of calcium hardness and total alkalinity being more than 100mg/L and less than 900 mg/L; the pH value of the circulating cooling water is 7.9-8.5;
wherein the sulfonate copolymer is contained in an amount of 30 to 270 parts by weight and the zinc salt is Zn based on 100 parts by weight of the compound A2+The content is 4-40 weight portions, and the content of the copper corrosion inhibitor is 5-50 weight portions.
6. The method of claim 5 wherein the sulfonate copolymer is a disulfonate copolymer or a trisulfonate copolymer.
7. The method of claim 6, wherein the sulfonate copolymer is selected from the group consisting of acrylic acid/2-acrylamido-2-methylpropanesulfonic acid copolymer, acrylic acid/2-acrylamido-2-methylpropanesulfonic acid/hydroxypropyl acrylate copolymer, acrylic acid/acrylate/sulfonate copolymer, carboxylate/sulfonate/nonionic copolymer, acrylic acid/styrenesulfonic acid copolymer, acrylate/styrenesulfonic acid copolymer, acrylic acid/allylsulfonic acid copolymer, acrylic acid/vinylsulfonic acid copolymer, acrylic acid/2-methyl-2 '-acrylamidopropanesulfonic acid copolymer, acrylic acid/acrylamide/2-methyl-2' -acrylamidopropanesulfonic acid copolymer, and mixtures thereof, At least one of acrylic acid/maleic acid/2-methyl-2 '-acrylamidopropanesulfonic acid copolymer and acrylic acid/acrylate-2-methyl-2' -acrylamidopropanesulfonic acid copolymer.
8. The method according to any one of claims 5-7, wherein the zinc salt is zinc sulphate and/or zinc chloride.
9. The method according to any one of claims 5-7, wherein the copper corrosion inhibitor is an azole compound.
10. The method of claim 9, wherein the copper corrosion inhibitor is selected from at least one of benzotriazole, methylbenzotriazole, and mercaptobenzotriazol.
11. A treatment method of circulating cooling water is characterized by comprising the steps of contacting the circulating cooling water with a phosphorus-free composite corrosion and scale inhibitor solution;
wherein the phosphorus-free composite corrosion and scale inhibitor solution consists of water and the phosphorus-free composite corrosion and scale inhibitor of any one of claims 1 to 10, and the content of the water is 30 to 80 parts by weight based on 100 parts by weight of the phosphorus-free composite corrosion and scale inhibitor;
wherein the circulating cooling water is medium-hardness water with the sum of calcium hardness and total alkalinity being more than 100mg/L and less than 900 mg/L; the pH value of the circulating cooling water is 7.9-8.5.
12. The method according to claim 1 or 11, wherein the phosphorus-free composite corrosion and scale inhibitor or the phosphorus-free composite corrosion and scale inhibitor solution is used in an amount such that the concentration of compound a is 2-16mg/L, the concentration of the sulfonate copolymer is 3-12mg/L, and Zn is used in the circulating cooling water per liter of the circulating cooling water2+The concentration of the zinc salt is 0.5-2.5 mg/L.
13. The method according to claim 5 or 11, wherein the phosphorus-free composite corrosion and scale inhibitor or the phosphorus-free composite corrosion and scale inhibitor solution is used in an amount such that the concentration of the compound A is 2-16mg/L, the concentration of the sulfonate copolymer is 3-12mg/L, and Zn is used in the circulating cooling water per liter of the circulating cooling water2+The concentration of the zinc salt is 0.5-2.5mg/L, and the concentration of the copper corrosion inhibitor is 0.5-1.5 mg/L.
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