Energy-saving environment-friendly phosphorus-free boiler water treatment agent

Abstract

The invention discloses an energy-saving and environment-friendly phosphorus-free boiler water treatment agent, relates to the technical field of boiler water treatment, and aims to solve the problems of high discharge capacity, high energy consumption, high environmental protection pressure, poor water quality stability, inconvenience in operation and the like of a traditional phosphorus-containing agent. The boiler water treatment agent consists of alkaline amine, volatile amine, film-forming amine, a liquid scale inhibitor, a composite scale inhibitor, an organic deoxidant, an organic silt adjusting agent, absolute ethyl alcohol and deionized water according to specific parts by mass, and is prepared into a liquid medicament through processes of three-step stirring dissolution, mixing and the like. The boiler water treatment agent is phosphorus-free and environment-friendly, can reduce the blow-off rate and operation and maintenance difficulty of a boiler, ensures that boiler water and steam indexes reach the standard, prolongs the service life of equipment, remarkably saves water consumption, energy consumption and cost, and assists an enterprise in green production.

Description

Technical Field

[0001] This invention relates to the field of boiler water treatment technology, specifically to an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent. Background Technology

[0002] In the field of boiler water treatment technology, traditional boiler water stabilization treatment has long relied on phosphorus-containing agents such as trisodium phosphate. These agents inhibit scale formation by reacting with calcium and magnesium ions in the boiler water to generate phosphate precipitates, and rely on phosphate ions to help maintain the pH value of the boiler water. This is a relatively traditional water treatment solution in industrial boiler operation. However, with the increasing demands for energy conservation and environmental protection in the industrial sector, as well as the growing requirements for boiler operating efficiency, the limitations of traditional phosphorus-containing agents have gradually become apparent, making it difficult to meet the long-term stable, low-consumption, and environmentally friendly operation requirements of modern boilers.

[0003] The core shortcomings of traditional phosphorus-containing agents lie in their blowdown and energy consumption. Taking trisodium phosphate as an example, because it is a salt, its addition to the boiler drum significantly increases the salinity of the boiler water, leading to a substantial increase in its conductivity. To prevent salt accumulation from affecting steam quality, a large, continuous blowdown opening is required. Simultaneously, the process generates a large amount of phosphate precipitate in the boiler drum, necessitating frequent, periodic blowdowns, typically every 1-3 days, to remove the precipitate. This process not only wastes a significant amount of water resources but also results in substantial heat loss from the boiler water, significantly increasing the company's water and energy costs over the long term. Furthermore, frequent blowdowns accelerate wear on the blowdown valves, shortening their lifespan, and increasing the workload and labor intensity for on-site personnel.

[0004] Traditional phosphorus-containing agents also suffer from problems such as high environmental pressure, poor water quality stability, and inconvenient operation. After using phosphorus-containing agents, the direct discharge of phosphate ions in the wastewater can easily lead to eutrophication, failing to meet national environmental protection requirements. Subsequent phosphorus removal treatment requires additional equipment and costs, increasing the operational load on the water treatment section. Furthermore, trisodium phosphate has a weak buffering capacity for adjusting boiler water pH during boiler load fluctuations or abnormal influent water quality, easily causing sudden pH drops. Frequent adjustments to the dosing pump flow rate are necessary to maintain stable parameters, resulting in high operational complexity. Moreover, trisodium phosphate is prone to precipitation and caking due to temperature changes during storage and preparation, potentially clogging the dosing tank's drain pipes, affecting the accuracy of agent dosing, and consequently causing fluctuations in boiler water parameters, increasing the risk of boiler scaling and corrosion of pipelines and valves. Therefore, considering the limitations of the aforementioned technologies, there is an urgent need to develop an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent, which effectively solves the problems of large discharge volume, serious energy waste, high environmental pressure, poor water quality stability, and inconvenient operation of traditional phosphorus-containing agents.

[0006] To address the aforementioned problems in the prior art, the present invention provides the following technical solution:

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] This invention provides an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent, comprising the following raw materials in parts by weight: 5-6 parts of alkaline amine, 2-4 parts of volatile amine, 3-5 parts of film-forming amine, 12-20 parts of liquid scale inhibitor, 8-14 parts of composite scale inhibitor, 2-4 parts of organic deoxygenator, 1-2 parts of organic sludge conditioner, 12-18 parts of anhydrous ethanol, and 45-60 parts of deionized water.

[0009] Furthermore, the basic amine is at least one of ethanolamine, diethanolamine, or triethanolamine.

[0010] Furthermore, the volatile amine is at least one of cyclohexylamine, N-methyldiethanolamine, or diisopropanolamine.

[0011] Furthermore, the film-forming amine is at least one of octadecylamine, hexadecylamine, or tetradecylamine.

[0012] Furthermore, the liquid scale inhibitor is polyacrylic acid with a solid content of 30%-50%.

[0013] Furthermore, the composite scale inhibitor is composed of a mixture of hydrolyzed polymaleic anhydride, benzotriazole, and disodium ethylenediaminetetraacetate.

[0014] Furthermore, the mass ratio of the hydrolyzed polymaleic anhydride, benzotriazole, and disodium ethylenediaminetetraacetate is 5:1-4:2-5.

[0015] Furthermore, the solid content of the hydrolyzed polymaleic anhydride is 50%.

[0016] Furthermore, the organic oxygen scavenger is sodium isoascorbate.

[0017] Furthermore, the organic sludge-regulating agent is anionic polyacrylamide.

[0018] Furthermore, the preparation method of the energy-saving and environmentally friendly phosphorus-free boiler water treatment agent includes the following steps:

[0019] S1: Add basic amine to deionized water and stir, then add volatile amine and continue stirring, then add anhydrous ethanol, add film-forming amine and stir to dissolve, to obtain a poly-organic amine solution;

[0020] S2: Slowly add the organic scale inhibitor to the poly-organic amine solution and stir, then add the composite scale inhibitor and continue stirring to obtain a high molecular weight chelate dispersion solution;

[0021] S3: Add the liquid scale inhibitor to the polymer chelate dispersion solution and stir. Add the organic oxygen remover and continue stirring. After cooling to room temperature, seal and store to obtain an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent.

[0022] Further, the specific steps of S1 are as follows: add alkaline amine to deionized water, control the stirring speed at 200 rpm-300 rpm, stir at room temperature for 8 min-15 min, keep the stirring speed constant, slowly add volatile amine, after the volatile amine is added, continue stirring for 5 min-15 min, after the stirring is complete, add anhydrous ethanol, heat to 35℃-45℃, add film-forming amine in 3-5 portions, stir to dissolve, and obtain a polymeric organic amine solution;

[0023] Further, the specific steps of S2 are as follows: the organic scale inhibitor is slowly added to the poly-organic amine solution, the stirring speed is controlled at 300rpm-500rpm, and the mixture is stirred at 30℃-50℃ for 10min-15min; the composite scale inhibitor is added, the stirring speed is controlled at 300rpm-400rpm, and the mixture is stirred at 40℃-50℃ for 20min-35min to obtain a polymer chelate dispersion solution.

[0024] Further, the specific steps of S3 are as follows: add the liquid scale inhibitor to the polymer chelate dispersion solution, control the stirring speed at 200rpm-300rpm, stir at 30℃-40℃ for 15min-20min, add the organic oxygen remover, control the stirring speed at 150rpm-250rpm, stir at 35℃-45℃ for 30min-50min, cool to room temperature, seal and store to obtain the energy-saving and environmentally friendly phosphorus-free boiler water treatment agent.

[0025] The beneficial effects of this invention are:

[0026] 1. This invention can significantly reduce boiler blowdown rate from 3.0%-3.5% using traditional phosphorus-containing agents to 0.5%, a reduction of 2.5-3.0%. The continuous blowdown opening is reduced by 83%-86% year-on-year, and the scheduled blowdown frequency is extended from twice daily to once every 15 days, a reduction of 97% year-on-year. Based on two boilers with a rated evaporation capacity of 280t / h operating for 8000 hours annually, this can save 672,000 tons of demineralized water annually, saving 1,008,000 yuan in water costs; simultaneously, it reduces heat loss, equivalent to saving 9996.1 tons of coal annually, saving approximately 4,998,000 yuan in coal costs, demonstrating significant water and energy savings.

[0027] 2. Compared with traditional trisodium phosphate agents, this phosphate-free water treatment agent can maintain the pH value of boiler water stably within the optimal range of 9.0-10.5, meeting the requirements of GB / T12145-2016 standard, avoiding the risk of corrosion caused by sudden pH drops; the conductivity of boiler water is stably controlled within 50μs / cm, the silica content is <2mg / L, the sodium ion content of steam is ≤5μg / L, the silica content is ≤15μg / L, and the conductivity is ≤10μs / cm, comprehensively ensuring the quality of water and steam, reducing boiler scaling and pipeline and valve corrosion, extending equipment service life, and reducing maintenance costs.

[0028] 3. This invention contains no phosphorus. After use, the phosphate content in the boiler water gradually decreases from 2-8 mg / L in traditional processes to below 0.5 mg / L, eventually approaching zero, completely solving the eutrophication problem in wastewater caused by traditional phosphorus-containing agents. Enterprises do not need to invest in additional phosphorus removal equipment and incur operating costs, reducing the environmental burden on water treatment processes while meeting national environmental emission requirements, avoiding environmental penalties, and helping enterprises achieve green production transformation.

[0029] 4. Traditional trisodium phosphate suffers from problems such as easy precipitation and caking during storage, and easy clogging of dosing pipelines during preparation, requiring frequent adjustments to the dosing pump flow rate to maintain water quality stability. In contrast, this phosphate-free water treatment agent is a stable liquid system, convenient to store and add. During stable operation, the average dosage is only 4.0g / ton / steam - 4.5g / ton / steam, eliminating the need for frequent adjustments. It also features scale removal, metal passivation, and coating functions, reducing boiler cleaning frequency, lowering the workload and operational intensity of staff, and improving production efficiency. Detailed Implementation

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The anionic polyacrylamide used in this embodiment of the invention was purchased from Shandong Delan Chemical Co., Ltd.

[0032] In this embodiment of the invention, the polyacrylic acid was purchased from Shandong Delan Chemical Co., Ltd.

[0033] The hydrolyzed polymaleic anhydride in this embodiment of the invention was purchased from Shandong Delan Chemical Co., Ltd.

[0034] Example 1

[0035] A method for preparing an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent includes the following steps:

[0036] S1: Add 45 parts of deionized water to a jacketed stirred reaction vessel, start stirring, and control the stirring speed at 200 rpm; slowly add 5 parts of ethanolamine and continue stirring at room temperature for 8 minutes; keep the stirring speed at 200 rpm constant and slowly add 2 parts of cyclohexylamine dropwise, and continue stirring for 5 minutes after the addition is complete; then add 12 parts of anhydrous ethanol to the vessel, raise the jacket temperature to 35°C, and add 3 parts of octadecylamine in 3 portions, 1 part each time, with an interval of 2 minutes. After each addition, continue stirring until the octadecylamine is completely dissolved to obtain a polycyclic organic amine solution.

[0037] S2: Keep the jacket temperature of the stirred reaction vessel at 30°C, slowly add 1 part of anionic polyacrylamide to the above multi-organic amine solution, adjust the stirring speed to 300 rpm, and continue stirring for 10 min; then add 8 parts of composite scale inhibitor, which is composed of 5 parts of hydrolyzed polymaleic anhydride with a solid content of 50%, 1 part of benzotriazole, and 2 parts of disodium ethylenediaminetetraacetate pulverized through an 80-mesh sieve. Keep the stirring speed at 300 rpm, raise the jacket temperature to 40°C, and continue stirring for 20 min to obtain a polymer chelated dispersion solution.

[0038] S3: Add 12 parts of liquid scale inhibitor to the polymer chelate dispersion solution. The liquid scale inhibitor is polyacrylic acid with a solid content of 30%. Adjust the stirring speed to 200 rpm, control the jacket temperature at 30°C, and continue stirring for 15 min. Then add 2 parts of sodium isoascorbate, reduce the stirring speed to 150 rpm, raise the jacket temperature to 35°C, and continue stirring for 30 min. After stirring, turn off the heating device and let the system cool naturally to room temperature. Transfer the product to a sealed storage tank for storage to obtain the energy-saving and environmentally friendly phosphorus-free boiler water treatment agent.

[0039] Example 2

[0040] A method for preparing an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent includes the following steps:

[0041] S1: Add 48 parts of deionized water to a jacketed stirred reaction vessel, start stirring, and control the stirring speed at 220 rpm; slowly add 5.2 parts of diethanolamine and continue stirring at room temperature for 10 min; keep the stirring speed at 220 rpm and slowly add 2.5 parts of N-methyldiethanolamine dropwise, and continue stirring for 8 min after the addition is complete; then add 13.5 parts of anhydrous ethanol to the vessel, raise the jacket temperature to 38°C, and add 3.5 parts of hexadecylamine in 3 portions, adding 1.2 parts each for the first two portions and 1.1 parts for the last portion, with an interval of 2 min. After each addition, continue stirring until the hexadecylamine is completely dissolved to obtain a polycyclic organic amine solution.

[0042] S2: Keep the jacket temperature of the stirred reaction vessel at 35°C, slowly add 1.2 parts of anionic polyacrylamide to the above multi-organic amine solution, adjust the stirring speed to 350 rpm, and continue stirring for 12 min; then add 10 parts of composite scale inhibitor, which is composed of 5 parts of hydrolyzed polymaleic anhydride with a solid content of 50%, 2 parts of benzotriazole, and 3 parts of disodium ethylenediaminetetraacetate pulverized through an 85-mesh sieve. Keep the stirring speed at 320 rpm, raise the jacket temperature to 42°C, and continue stirring for 25 min to obtain a polymer chelated dispersion solution.

[0043] S3: Add 14 parts of liquid scale inhibitor to the polymer chelate dispersion solution. The liquid scale inhibitor is polyacrylic acid with a solid content of 30%. Adjust the stirring speed to 220 rpm, control the jacket temperature at 32℃, and continue stirring for 16 min. Then add 2.5 parts of sodium isoascorbate, reduce the stirring speed to 180 rpm, raise the jacket temperature to 38℃, and continue stirring for 35 min. After stirring, turn off the heating device and let the system cool naturally to room temperature. Transfer the product to a sealed storage tank for storage to obtain the energy-saving and environmentally friendly phosphorus-free boiler water treatment agent.

[0044] Example 3

[0045] A method for preparing an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent includes the following steps:

[0046] S1: Add 52 parts of deionized water to a jacketed stirred reaction vessel, start stirring, and control the stirring speed at 250 rpm; slowly add 5.5 parts of triethanolamine and continue stirring at room temperature for 12 min; keep the stirring speed at 250 rpm and slowly add 3 parts of diisopropanolamine dropwise, and continue stirring for 10 min after the addition is complete; then add 15 parts of anhydrous ethanol to the vessel, raise the jacket temperature to 40°C, and add 4 parts of tetradecylamine in 4 portions, 1 part each time, with an interval of 2 min. After each addition, continue stirring until the tetradecylamine is completely dissolved to obtain a polycyclic organic amine solution.

[0047] S2: Keep the jacket temperature of the stirred reaction vessel at 40°C, slowly add 1.5 parts of anionic polyacrylamide to the above multi-organic amine solution, adjust the stirring speed to 400 rpm, and continue stirring for 13 min; then add 11 parts of composite scale inhibitor, which is composed of 5 parts of hydrolyzed polymaleic anhydride with a solid content of 50%, 2 parts of benzotriazole, and 4 parts of disodium ethylenediaminetetraacetate pulverized through a 90-mesh sieve. Keep the stirring speed at 350 rpm, raise the jacket temperature to 45°C, and continue stirring for 28 min to obtain a polymer chelated dispersion solution.

[0048] S3: Add 16 parts of liquid scale inhibitor to the polymer chelate dispersion solution. The liquid scale inhibitor is polyacrylic acid with a solid content of 40%. Adjust the stirring speed to 250 rpm, control the jacket temperature at 35°C, and continue stirring for 18 minutes. Then add 3 parts of sodium isoascorbate, reduce the stirring speed to 200 rpm, raise the jacket temperature to 40°C, and continue stirring for 40 minutes. After stirring, turn off the heating device and let the system cool naturally to room temperature. Transfer the product to a sealed storage tank for storage to obtain the energy-saving and environmentally friendly phosphorus-free boiler water treatment agent.

[0049] Example 4

[0050] A method for preparing an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent includes the following steps:

[0051] S1: Add 55 parts of deionized water to a jacketed stirred reaction vessel, start stirring, and control the stirring speed at 280 rpm; slowly add 5.8 parts of a mixture of ethanolamine and diethanolamine, with a mass ratio of ethanolamine to diethanolamine of 1:1, and continue stirring at room temperature for 14 min; keep the stirring speed constant at 280 rpm, and slowly add 3.5 parts of a mixture of cyclohexylamine and N-methyldiethanolamine, with a mass ratio of cyclohexylamine to N-methyldiethanolamine of 1:1, and continue stirring for 12 min after the addition is complete; then add 16.5 parts of anhydrous ethanol to the vessel, raise the jacket temperature to 42℃, and add 4.5 parts of a mixture of octadecylamine and hexadecylamine, with a mass ratio of octadecylamine to hexadecylamine of 1:1, in 4 portions, adding 1.125 parts each time, with an interval of 2 min, and continue stirring after each addition until the mixed amine is completely dissolved to obtain a polymeric organic amine solution.

[0052] S2: Keep the jacket temperature of the stirred reaction vessel at 45°C, slowly add 1.8 parts of anionic polyacrylamide to the above multi-organic amine solution, adjust the stirring speed to 450 rpm, and continue stirring for 14 min; then add 13 parts of composite scale inhibitor, which is composed of 5 parts of hydrolyzed polymaleic anhydride with a solid content of 50%, 3 parts of benzotriazole, and 5 parts of disodium ethylenediaminetetraacetate pulverized through a 90-mesh sieve and mixed. Keep the stirring speed at 380 rpm, raise the jacket temperature to 48°C, and continue stirring for 32 min to obtain a polymer chelated dispersion solution.

[0053] S3: Add 18 parts of liquid scale inhibitor to the polymer chelate dispersion solution. The liquid scale inhibitor is polyacrylic acid with a solid content of 40%. Adjust the stirring speed to 280 rpm, control the jacket temperature at 38℃, and continue stirring for 19 min. Then add 3.5 parts of sodium isoascorbate, reduce the stirring speed to 220 rpm, raise the jacket temperature to 42℃, and continue stirring for 45 min. After stirring, turn off the heating device and let the system cool naturally to room temperature. Transfer the product to a sealed storage tank for storage to obtain the energy-saving and environmentally friendly phosphorus-free boiler water treatment agent.

[0054] Example 5

[0055] A method for preparing an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent includes the following steps:

[0056] S1: Add 60 parts of deionized water to a jacketed stirred reaction vessel, start stirring, and control the stirring speed at 300 rpm; slowly add 6 parts of triethanolamine, and continue stirring at room temperature for 15 min; keep the stirring speed at 300 rpm constant, slowly add 4 parts of diisopropanolamine, and continue stirring for 15 min after the addition is complete; then add 18 parts of anhydrous ethanol to the vessel, raise the jacket temperature to 45°C, and add 5 parts of tetradecylamine in 5 portions, 1 part each time, with an interval of 2 min. After each addition, continue stirring until the tetradecylamine is completely dissolved to obtain a polycyclic organic amine solution.

[0057] S2: Keep the jacket temperature of the stirred reaction vessel at 50°C, slowly add 2 parts of anionic polyacrylamide to the above multi-organic amine solution, adjust the stirring speed to 500 rpm, and continue stirring for 15 min; then add 14 parts of composite scale inhibitor, which is composed of 5 parts of hydrolyzed polymaleic anhydride with a solid content of 50%, 4 parts of benzotriazole, and 5 parts of disodium ethylenediaminetetraacetate pulverized through a 100-mesh sieve. Keep the stirring speed at 400 rpm, raise the jacket temperature to 50°C, and continue stirring for 35 min to obtain a polymer chelated dispersion solution.

[0058] S3: Add 20 parts of liquid scale inhibitor to the polymer chelate dispersion solution. The liquid scale inhibitor is polyacrylic acid with a solid content of 50%. Adjust the stirring speed to 300 rpm, control the jacket temperature at 40℃, and continue stirring for 20 min. Then add 4 parts of sodium isoascorbate, reduce the stirring speed to 250 rpm, raise the jacket temperature to 45℃, and continue stirring for 50 min. After stirring, turn off the heating device and let the system cool naturally to room temperature. Transfer the product to a sealed storage tank for storage to obtain the energy-saving and environmentally friendly phosphorus-free boiler water treatment agent.

[0059] Comparative Example 1

[0060] Compared with Example 3, this comparative example replaces the "composite scale inhibitor" with the same mass of "sodium tripolyphosphate". All other steps and parameters are the same, and will not be repeated in this comparative example. Finally, an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent is obtained.

[0061] Comparative Example 2

[0062] Compared with Example 3, this comparative example does not add octadecylamine, and all other steps and parameters are the same. The details of this comparative example will not be repeated here. Finally, an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent is obtained.

[0063] Comparative Example 3

[0064] Compared with Example 3, this comparative example replaces the "organic deoxygenating agent sodium isoascorbate" with an equal mass of "sodium sulfite". All other steps and parameters are the same, and will not be repeated in this comparative example. Finally, an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent is obtained.

[0065] Comparative Example 4

[0066] Compared with Example 3, this comparative example replaces "hydrolyzed polymaleic anhydride with a solid content of 50%" with the same mass of "polyacrylic acid with a solid content of 50%". All other steps and parameters are the same, and will not be repeated in this comparative example. Finally, an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent is obtained.

[0067] Comparative Example 5

[0068] Compared with Example 3, this comparative example does not add anionic polyacrylamide, but all other steps and parameters are the same. This comparative example will not be repeated here. Finally, an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent is obtained.

[0069] According to GB / T12145-2016 "Water and Steam Quality Standard for Thermal Power Generating Units and Steam Power Equipment", the performance of the energy-saving and environmentally friendly phosphorus-free boiler water treatment agents prepared in Examples 1-5 and Comparative Examples 1-5 was tested. The detailed results are shown in Table 1.

[0070] Table 1

[0071]

[0072] Based on the analysis of test data, the energy-saving and environmentally friendly phosphorus-free boiler water treatment agents prepared in Examples 1-3 of this invention have the following advantages:

[0073] Excellent water quality stability: The pH value of the boiler water is stable at 9.07-9.55, which meets the 9.0-10.5 range of GB / T12145-2016 standard, and the fluctuation is small; the conductivity of the boiler water is controlled at 9.36μs / cm-33.0μs / cm, which is far lower than the high conductivity of traditional phosphorus-containing agents, effectively reducing the need for sewage discharge.

[0074] Outstanding environmental performance: The phosphate content in the boiler water is low, ranging from 0.06 mg / L to 0.48 mg / L, which is close to being phosphorus-free. This completely solves the problem of eutrophication caused by traditional phosphorus-containing agents and eliminates the need for additional phosphorus removal treatment.

[0075] Steam quality meets standards: saturated steam sodium ion content of 0.4μg / L-1.6μg / L, silica content of 1.6μg / L-11.8μg / L, and electrical conductivity of 3.22μs / cm-6.46μs / cm all meet the standard requirements, ensuring the safe and stable operation of the boiler.

[0076] Significant scale and corrosion inhibition effects: Through the synergistic effect of composite scale inhibitor and organic sludge regulator, the silica content of boiler water is effectively controlled at 0.16mg / L-0.47mg / L, reducing the risk of scaling and corrosion.

[0077] A comparison of Comparative Example 1 and Example 2 shows that after replacing the composite scale inhibitor with sodium tripolyphosphate in Comparative Example 1, the boiler water pH decreased to 8.65, the conductivity increased to 18.6 μS / cm, and the saturated steam silica reached 16.5 μg / L. This indicates that the composite scale inhibitor, composed of hydrolyzed polymaleic anhydride, benzotriazole, and disodium EDTA, is significantly more effective than sodium tripolyphosphate in maintaining pH stability, reducing conductivity, and ensuring steam quality, and its phosphorus-free nature makes it more environmentally friendly.

[0078] A comparison of Comparative Example 2 and Example 2 shows that: without the addition of the film-forming amine octadecylamine, the boiler water conductivity in Comparative Example 2 increased to 25.4 μS / cm, higher than the 12.89 μS / cm in Example 2; the saturated steam conductivity was 6.82 μS / cm, higher than the 3.22 μS / cm in Example 2. This indicates that the film-forming amine, by forming a protective film on the metal surface, can not only reduce the conductivity of boiler water and steam, but also enhance the corrosion inhibition effect, making it a key component for maintaining water quality stability.

[0079] A comparison of Comparative Example 3 and Example 2 shows that after replacing the organic scavenger sodium isoascorbate with sodium sulfite in Comparative Example 3, the boiler water conductivity increased to 30.2 μS / cm, significantly higher than the 12.89 μS / cm in Example 2. The saturated steam sodium ion concentration was 3.2 μg / L, higher than the 1.6 μg / L in Example 2, and the saturated steam silica concentration was 12.8 μg / L, also higher than the 1.6 μg / L in Example 2. This indicates that sodium sulfite, as an inorganic scavenger, introduces impurities such as sodium ions, increasing the salinity of the boiler water and leading to higher conductivity, while also affecting steam purity. In contrast, sodium isoascorbate, as an organic scavenger, offers stable deoxygenation efficiency without introducing additional salts, better maintaining boiler water and steam quality. It is a crucial component for ensuring the environmental friendliness of the reagent and the stability of the water quality.

[0080] A comparison of Comparative Example 4 and Example 2 shows that after replacing hydrolyzed polymaleic anhydride with polyacrylic acid in Comparative Example 4, the boiler water conductivity surged to 65.8 μS / cm, far exceeding the 12.89 μS / cm in Example 2; the boiler water phosphate concentration reached 5.86 mg / L, indicating phosphorus content and environmental unfriendliness. This demonstrates that the carboxyl structure of hydrolyzed polymaleic anhydride exhibits superior scale inhibition and dispersion performance compared to polyacrylic acid, and its synergistic effect with benzotriazole and disodium ethylenediaminetetraacetate is more significant, making it the core component for achieving low conductivity and phosphorus-free environmental friendliness.

[0081] A comparison of Comparative Example 5 and Example 2 shows that: Comparative Example 5, without the addition of anionic polyacrylamide organic sludge conditioner, had a furnace water silica content of 0.63 mg / L, higher than the 0.47 in Example 2; and an electrical conductivity of 28.7 μS / cm, higher than the 12.89 in Example 2. This indicates that the organic sludge conditioner effectively aggregates and removes fine impurities such as silica scale particles, reducing deposits in the furnace, and is an important auxiliary component for maintaining low silica content and electrical conductivity.

[0082] The No. 3 boiler in the thermal power coal preparation plant began using the energy-saving and environmentally friendly phosphorus-free boiler water treatment agent prepared in Example 1 on November 22, 2024, and the No. 1 boiler began using the same agent for dosing and commissioning on November 25, 2024. Initially, the dosing was concentrated and the dosage was relatively large; during the stabilization period, the average dosage remained stable at 4.0-4.5 g / ton of steam.

[0083] The operation report analyzes data from boilers #1 and #3 before and after the addition of the phosphate-free boiler water treatment agent. The proposed solution involves adding the energy-saving and environmentally friendly phosphate-free boiler water treatment agent prepared in Example 1 to the boiler drum, replacing the original sodium tripolyphosphate dosing method. The original sodium tripolyphosphate dosing was discontinued, while the ammonia dosing method remained unchanged. The operational status during the period of adding the phosphate-free boiler water treatment agent is as follows.

[0084] I. Boiler Operation Overview

[0085] Regular exhaust: The regular exhaust cycle for boilers #1 and #3 has been extended from twice a day to once every 10 days.

[0086] Continuous flow: Boiler #1 was moved from the original continuous flow to the expansion vessel. The manual secondary valve was opened 3 turns and then closed to a slightly open flow state.

[0087] The No. 3 boiler was originally connected to the expansion vessel, and the manual secondary valve was opened 3.5 turns, then closed to a slightly open flow state.

[0088] Boiler water parameters: The pH value of the boiler water is stable between 9.0 and 10.5.

[0089] The conductivity of the boiler water is stabilized below 50 μS / cm; the silica content of the boiler water is <2 mg / L, and the phosphate content is reduced to 0.5 mg / L. With the use of the reagents, the phosphate content of the boiler water will gradually decrease to 0.

[0090] Steam specifications: Sodium ion concentration ≤5ug / L, silica concentration ≤15ug / L, and electrical conductivity ≤10us / cm in saturated and superheated steam all meet the requirements.

[0091] II. Performance indicators during the assessment period after adopting phosphorus-free boiler water treatment agents

[0092] The following is a data table comparing the traditional dosing process with the new boiler water treatment agent. The data comparison period is from November 15th to November 21st for the sodium tripolyphosphate control method, and from November 26th to December 6th for the phosphate-free boiler water treatment agent control method. Data at 9:00 AM each day is used for comparison.

[0093] All data are based on the test data from the quality inspection center.

[0094] 1. Boiler water parameters

[0095] According to the requirements of the plan, the pH value of the boiler water should be controlled between 9.0 and 10.5, the conductivity should be controlled below 50 μS / cm, and the silica concentration should be controlled below 2 mg / L. Previously, trisodium phosphate was used. During the assessment period, the energy-saving and environmentally friendly phosphorus-free boiler water treatment agent prepared in Example 1 was used, and the treatment results are shown in Table 2.

[0096] Table 2

[0097]

[0098] 1.1 Boiler water pH

[0099] As shown in Table 1, after using the phosphorus-free boiler water treatment agent, the pH of the boiler water increased from 8.4-9.0 when using trisodium phosphate to over 9.0, and the pH of the boiler water remained stable, meeting the requirements of GB / T12145-2016 "Water and Steam Quality Standards for Thermal Power Generating Units and Steam Power Equipment".

[0100] 1.2 Boiler water conductivity

[0101] As shown in Table 1, from November 26 to December 2, the boiler water conductivity was controlled below 45 μS / cm despite a significant reduction in the sewage discharge rate. This ensured that the boiler water conductivity met the required standards while achieving water and sewage reduction.

[0102] 1.3 Boiler Cleaning

[0103] The energy-saving and environmentally friendly phosphorus-free boiler water treatment agent prepared in Example 1 has the ability to remove existing scale and rust. The cleaning and removal process does not damage the pipe structure. Long-term accumulation of scale and rust can lead to under-deposit corrosion, further damaging the pipes. Cleaning avoids this problem. The agent also has the functions of passivating metals and forming a coating, further reducing corrosion in pipes and the steam drum.

[0104] 1.4 Boiler water silica

[0105] As shown in Table 1, the silica concentration of <2 mg / L meets the requirements of GB / T12145-2016 "Water and Steam Quality Standards for Thermal Power Generating Units and Steam Power Equipment".

[0106] 1.5 boiler water phosphate

[0107] As shown in Table 1, the phosphate content in the boiler water decreased significantly. On November 30th, boiler load fluctuated, and trisodium phosphate dissolution occurred. With the replacement of wastewater, the phosphate content rapidly decreased. Subsequently, with the use of chemicals, the phosphate content in the boiler water will gradually decrease to 0, significantly reducing phosphorus emissions for the company and alleviating the pressure on the subsequent phosphorus removal system. This greatly reduces the phosphorus content in the discharged wastewater, making it more environmentally friendly. Simultaneously, it reduces and mitigates the increase in boiler water conductivity caused by the addition of trisodium phosphate, thus lowering the wastewater discharge rate.

[0108] 2. Steam Indicators

[0109] According to GB / T12145-2016 "Water and Steam Quality Standards for Thermal Power Generating Units and Steam Power Equipment" and the manufacturer's standard, the requirements for steam sodium ion concentration are ≤5ug / L, silica concentration is ≤15ug / L, and steam conductivity is ≤10us / cm. Previously, trisodium phosphate was used. During the evaluation period, the energy-saving and environmentally friendly phosphorus-free boiler water treatment agent prepared in Example 1 was used. The treatment results are shown in Tables 3 and 4.

[0110] Table 3

[0111]

[0112] Table 4

[0113]

[0114] 2.1 Sodium ions in vapor

[0115] As can be seen from Tables 1 and 2, during the trial period, the two boilers greatly reduced the blowdown rate while ensuring that the sodium ion concentration in the saturated steam and superheated steam was ≤5ug / L, which ensured that the sodium ion concentration in the superheated steam met the requirements of GB / T12145-2016 "Water and Steam Quality Standards for Thermal Power Generating Units and Steam Power Equipment".

[0116] 2.2 Steam-generated silica

[0117] As can be seen from Tables 1 and 2, the silica content on the steam side is ≤15ug / L. This greatly reduces the sewage discharge rate while ensuring that the silica content of saturated steam and superheated steam meets the requirements of GB / T12145-2016 "Water and Steam Quality Standard for Thermal Power Generating Units and Steam Power Equipment".

[0118] 2.2 Steam conductivity

[0119] As can be seen from Tables 1 and 2, the steam conductivity is ≤10µs / cm, which greatly reduces the sewage discharge rate while ensuring that the conductivity of saturated steam and superheated steam meets the factory standard requirements.

[0120] III. Dosage

[0121] Due to the initial influence of the initial dosage, the overall dosage of the phosphorus-free boiler water treatment agent was relatively large during the initial dosing period. From November 26th to December 6th, the average dosage concentration of the energy-saving and environmentally friendly phosphorus-free boiler water treatment agent prepared in Example 1 was 4.0 g / ton·steam - 4.5 g / ton·steam. Details are shown in Table 5 below:

[0122] Table 5

[0123]

[0124] IV. Sewage Discharge

[0125] V. The original boiler blowdown rate was 3.0%-3.5%. Considering the decrease in continuous blowdown opening and fixed blowdown frequency after using the phosphate-free boiler water treatment agent, it is estimated that the blowdown rate will decrease by approximately 0.5% after using the phosphate-free boiler water treatment agent. The blowdown rate will decrease by approximately 2.5%-3.0%, as detailed in Table 6.

[0126] Table 6

[0127]

[0128] As shown in Table 5, after using the phosphate-free boiler water treatment agent, the continuous discharge opening decreased by about 83%-86% year-on-year, and the fixed discharge decreased by about 97% year-on-year. Therefore, it is estimated that the blowdown rate after using the phosphate-free boiler water treatment agent is about 0.5%, which is a decrease of 2.5%-3.0%.

[0129] V. Economic Benefits

[0130] The calculation is based on an initial wastewater discharge rate of 2%, a wastewater discharge rate of 0.5% after using a phosphate-free water treatment agent, and an evaporation capacity of 280 t / h for a single boiler. The calculation is based on an evaporation capacity of 280 t / h for a single boiler, with two boilers operating for 8000 hours and one boiler operating for 4000 hours. Detailed results are shown in Table 7.

[0131] Table 7

[0132]

[0133] Using phosphate-free boiler water treatment agent results in annual savings of approximately 570,400 yuan.

[0134] Note: This example uses a demineralized water price of 15 yuan / ton, a coal calorific value of 3200kcal / kg-3700kcal / kg, taking 3500kcal / Kg=14630kJ / kg, and a coal price of 500 yuan / ton.

[0135] The enthalpy of the boiler water at 9.8 MPa is 1399.03 kJ / kg, and the enthalpy of water at 25℃ is 104.86 kJ / kg; the boiler thermal efficiency is taken as 90%.

[0136] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An energy-saving and environmentally friendly phosphorus-free boiler water treatment agent, characterized in that, The raw materials include the following parts by weight: 5-6 parts basic amine, 2-4 parts volatile amine, 3-5 parts film-forming amine, 12-20 parts liquid scale inhibitor, 8-14 parts composite scale inhibitor, 2-4 parts organic oxygen remover, 1-2 parts organic sludge conditioner, 12-18 parts anhydrous ethanol, and 45-60 parts deionized water.

2. The energy-saving and environmentally friendly phosphorus-free boiler water treatment agent according to claim 1, characterized in that, The basic amine is at least one of ethanolamine, diethanolamine, or triethanolamine.

3. The energy-saving and environmentally friendly phosphorus-free boiler water treatment agent according to claim 1, characterized in that, The volatile amine is at least one of cyclohexylamine, N-methyldiethanolamine, or diisopropanolamine.

4. The energy-saving and environmentally friendly phosphorus-free boiler water treatment agent according to claim 1, characterized in that, The film-forming amine is at least one of octadecylamine, hexadecylamine, or tetradecylamine.

5. The energy-saving and environmentally friendly phosphorus-free boiler water treatment agent according to claim 1, characterized in that, The liquid scale inhibitor is polyacrylic acid with a solid content of 30%-50%.

6. The energy-saving and environmentally friendly phosphorus-free boiler water treatment agent according to claim 1, characterized in that, The composite scale inhibitor is composed of a mixture of hydrolyzed polymaleic anhydride, benzotriazole, and disodium ethylenediaminetetraacetate.

7. The energy-saving and environmentally friendly phosphorus-free boiler water treatment agent according to claim 6, characterized in that, The mass ratio of the hydrolyzed polymaleic anhydride, benzotriazole, and disodium ethylenediaminetetraacetate is 5:1-4:2-5.

8. The energy-saving and environmentally friendly phosphorus-free boiler water treatment agent according to claim 1, characterized in that, The organic oxygen scavenger is sodium isoascorbate.

9. The energy-saving and environmentally friendly phosphorus-free boiler water treatment agent according to claim 1, characterized in that, The organic sludge-regulating agent is anionic polyacrylamide.

10. The energy-saving and environmentally friendly phosphorus-free boiler water treatment agent according to claim 1, characterized in that, The preparation method of the energy-saving and environmentally friendly phosphorus-free boiler water treatment agent includes the following steps: S1: Add basic amine to deionized water and stir, then add volatile amine and continue stirring, then add anhydrous ethanol, add film-forming amine and stir to dissolve, to obtain a poly-organic amine solution; S2: Slowly add the organic scale inhibitor to the poly-organic amine solution and stir, then add the composite scale inhibitor and continue stirring to obtain a polymer chelate dispersion solution; S3: Add the liquid scale inhibitor to the polymer chelate dispersion solution and stir. Add the organic oxygen remover and continue stirring. After cooling to room temperature, seal and store to obtain an energy-saving and environmentally friendly phosphorus-free boiler water treatment agent.

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