Environment-friendly boiler energy-saving scale inhibitor, preparation method and application thereof

Abstract

The application discloses an environment-friendly boiler energy-saving scale inhibitor and a preparation method and application thereof. The environment-friendly boiler energy-saving scale inhibitor is prepared from ethanolamine, cyclohexylamine, sodium sarcosinate, sodium isopropyl phenyl sulfonate, sulfonated succinic acid dioctyl ester and sodium hydroxide; the environment-friendly boiler energy-saving scale inhibitor has a simple use method, can reduce the conductivity of boiler water, reduces the pollution discharge rate, effectively improves the steam quality, avoids the occurrence of salt accumulation, makes the steam turbine more safe, stable, efficient and long-period, simultaneously can greatly save the cost, and the preparation method is simple. Therefore, the environment-friendly boiler energy-saving scale inhibitor has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of boiler water treatment agents, specifically relating to an environmentally friendly boiler energy-saving scale inhibitor, its preparation method, and its application. Background Technology

[0002] When water is heated in a boiler, it boils and evaporates, providing conditions for chemical reactions and continuous concentration of impurities in the water. When these impurities reach a certain saturation point in the boiler, they form solid substances. If they are suspended in the boiler water, they are called "water slag," and if they are deposited on the heated surfaces, they are called "scale." To prevent the formation of scale and other deposits during boiler operation, and to prevent scaling, corrosion, and steam-water medley in boiler thermal equipment, ensuring safe, efficient, economical, and environmentally friendly boiler operation, it is essential to strengthen boiler water treatment and ensure that the boiler water quality meets national standards.

[0003] Currently, dry-quenched coke boilers use trisodium phosphate as a scale inhibitor for boiler feedwater treatment. This agent is an inorganic salt. Dimethyl ketoxime is used as an auxiliary deoxygenating agent for boiler feedwater. The addition of both agents increases the salinity of the boiler water, leading to an increase in its conductivity. To maintain the boiler water conductivity within the national standard control range (≤150 μS / cm), continuous blowdown and regular blowdown must be increased. The large-scale discharge of boiler water not only increases the boiler feedwater volume but also removes a significant amount of heat, resulting in reduced boiler thermal efficiency. Furthermore, trisodium phosphate exhibits a "hidden" phenomenon when boiler load fluctuates significantly, making it difficult to control phosphate levels within the standard range (2–6 mg / L). Excessively high or low phosphate concentrations can lead to secondary phosphate scaling, posing a significant threat to the safe operation of the boiler. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides an environmentally friendly boiler energy-saving scale inhibitor, its preparation method, and its application. This agent can improve boiler thermal efficiency, is phosphorus-free and environmentally friendly, improves steam and boiler water quality, and has a simple preparation method.

[0005] The proposed technical solution of this invention is as follows:

[0006] This invention provides an environmentally friendly boiler energy-saving scale inhibitor, the components of which include: ethanolamine, cyclohexylamine, sodium sarcosinate, sodium isopropylbenzenesulfonate, dioctyl sulfonate, and sodium hydroxide.

[0007] Further, by weight, the components of the boiler energy-saving scale inhibitor include: 50-150 parts of ethanolamine, 40-100 parts of cyclohexylamine, 1-10 parts of sodium sarcosinate, 1-10 parts of sodium isopropylbenzenesulfonate, 1-5 parts of dioctyl sulfonate, 5-15 parts of sodium hydroxide, and 700-850 parts of water.

[0008] Further, by weight, the components of the boiler energy-saving scale inhibitor include: 120 parts ethanolamine, 60 parts cyclohexylamine, 1 part sodium sarcosinate, 4 parts sodium isopropylbenzenesulfonate, 1 part dioctyl sulfosuccinate, 10 parts sodium hydroxide, and 800 parts water.

[0009] This invention also provides a method for preparing the aforementioned environmentally friendly boiler energy-saving scale inhibitor, which includes the following steps:

[0010] (1) Add water to the reaction vessel, then add sodium hydroxide and stir until well mixed;

[0011] (2) Add ethanolamine, cyclohexylamine, sodium sarcosinate, sodium isopropylbenzenesulfonate, and dioctyl sulfosuccinate to the reaction vessel in sequence, and stir evenly to obtain boiler energy-saving scale inhibitor.

[0012] Furthermore, the temperature is controlled between 10-30℃ throughout the stirring process.

[0013] Furthermore, the solid content of the environmentally friendly boiler energy-saving scale inhibitor after drying is 2-4%, and the pH value of the redissolved solution is 11-12, and the density is 1.0-1.1.

[0014] This invention also provides the application of the aforementioned environmentally friendly boiler energy-saving scale inhibitor in the treatment of boiler boiler water.

[0015] Furthermore, the concentration of the environmentally friendly boiler energy-saving scale inhibitor is 1-10 ppm.

[0016] Furthermore, the boiler is a dry-quenched coke boiler.

[0017] Furthermore, the environmentally friendly boiler energy-saving scale inhibitor can improve boiler thermal efficiency, improve steam and boiler water quality, and reduce blowdown rate.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. The boiler energy-saving scale inhibitor of the present invention can reduce the boiler blowdown rate to less than 1%, reduce boiler wastewater by 50%, and improve boiler thermal efficiency.

[0020] 2. The boiler energy-saving scale inhibitor of the present invention is phosphorus-free and environmentally friendly, reducing phosphorus pollution to water and soil.

[0021] 3. The boiler energy-saving scale inhibitor of the present invention can improve the quality of steam and boiler water, with low boiler water conductivity and low salt content in superheated steam.

[0022] 4. The boiler energy-saving scale inhibitor of the present invention can coat the metal surfaces of turbine impellers, boiler tubes and other metal surfaces, thereby extending their overhaul cycle. Attached Figure Description

[0023] Figure 1A comparative chart of trends in pH index data for boiler water in steam drum boilers;

[0024] Figure 2 A comparative chart of trends in the electrical conductivity index of boiler water in a steam drum boiler;

[0025] Figure 3 A comparative chart of trends in silica content in boiler water of steam drum boilers;

[0026] Figure 4 This is a trend comparison chart of silica index data for superheated steam. Detailed Implementation

[0027] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.

[0028] Example 1

[0029] A method for preparing a boiler energy-saving scale inhibitor, the specific steps of which are as follows:

[0030] (1) Add 800 kg of deionized water to the reaction vessel, then add 10 kg of sodium hydroxide and stir until homogeneous;

[0031] (2) Add 120 kg of ethanolamine, 60 kg of cyclohexylamine, 1 kg of sodium sarcosinate, 4 kg of sodium isopropylbenzenesulfonate, and 1 kg of dioctyl sulfonate to the reactor in sequence, and stir evenly. The temperature is controlled at 10-30℃ throughout the process to obtain the boiler energy-saving scale inhibitor.

[0032] The boiler energy-saving scale inhibitor has an average solid content of 3.0% after drying, and the pH value of the transparent liquid after being diluted 100 times is 11.34 after three measurements, with a density of 1.03.

[0033] Example 2

[0034] The present invention applies the boiler energy-saving scale inhibitor prepared in Example 1 to a 9.8MPa, 540℃ high temperature and high pressure dry quenching coke boiler in a coking plant.

[0035] I. How to use

[0036] The usage method of boiler energy-saving scale inhibitor is as follows:

[0037] The dosing ratio for the chemical dosing tank is 1:14 (chemical agent: demineralized water). Water should be added first, followed by the chemical. The flow rate of the demineralized water should not be too high, as this will cause foaming of the chemical. The normal operating concentration of the chemical is 3-5 ppm.

[0038] II. Detection Indicators

[0039] The graphs show the trends of boiler water pH, boiler water conductivity, boiler water silica, and steam silica before and after the use of boiler energy-saving scale inhibitors during different periods (June 8, 2024 to June 18, 2024).

[0040] The brief testing steps for each indicator are as follows:

[0041] 1. Spectrophotometric method for determining trace silicon content:

[0042] Referenced standard: GB / T 12149-2017

[0043] (1) Measure a certain amount of water sample with a pipette and place it in a 200mL polyethylene beaker. Dilute it with water to 50.00mL using a burette.

[0044] (2) Add 1.00 mL of hydrochloric acid solution and 2.00 mL of ammonium molybdate solution, mix well, and let stand for 5 min.

[0045] (3) Add 1.00 mL of oxalic acid solution and mix well.

[0046] (4) Immediately after 1 min, add 2 mL of 1-amino-2-naphthol-4-sulfonic acid solution, mix well, and let stand for 10 min.

[0047] (5) Using a spectrophotometer and with a reagent blank as a reference, measure the absorbance at 810 nm using a 10 cm cuvette. Calculate the mass of silica from the calibration curve or by using a regression equation.

[0048] 2. Spectrophotometric method - Determination of constant silicon content:

[0049] Referenced standard: GB / T 12149-2017

[0050] (1) Use a pipette to measure a certain amount of the filtered water sample, place it in a 50mL colorimetric tube, and dilute it with water to the mark.

[0051] (2) Add 1.00 mL of hydrochloric acid solution and 2.00 mL of ammonium molybdate solution, mix well, and let stand for 5 min.

[0052] (3) Add 1.50 mL of oxalic acid solution and mix well.

[0053] (4) Immediately after 1 min, add 2.00 mL of 1-amino-2-naphthol-4-sulfonic acid solution, mix well, and let stand for 10 min.

[0054] (5) Using a spectrophotometer and with a reagent blank as a reference, measure the absorbance at 640 nm using a 1 cm cuvette. The mass of silica can be determined from the calibration curve or calculated using the regression equation.

[0055] 3. Procedure for determining the conductivity of water (DDSJ-308F instruction manual):

[0056] Referenced standard GB / T 6908-2018

[0057] (1) Clean the electrode with pure water, gently blot it dry with filter paper, rinse it two to three times with the solution to be tested, and then put it into the solution to be tested.

[0058] (2) Wait for the data to stabilize. Once stable, read the measurement results.

[0059] 4. Procedure for pH measurement in water (pHS-3E instruction manual):

[0060] Referenced standard GB / T 6904-2008

[0061] (1) After rinsing the electrode with the solution to be tested two to three times, immerse it in the solution to be tested;

[0062] (2) Wait for the data to stabilize, and then read the measurement results;

[0063] (3) In measurement mode, press the mode key "mV / pH" to switch between displaying mV or pH value.

[0064] III. Test Results

[0065] Based on the combined test results of various indicators, the following conclusions are drawn:

[0066] 1. According to the requirements of GB / T12145-2016 "Water and Steam Quality of Thermal Power Generating Units and Steam Power Equipment", the standard pH value of boiler water in the steam drum is 9.0-10.0, and the expected value is 9.5-9.7. (This is followed by a continuation of the previous sentence, which is incomplete and requires further context.) Figure 1 The comparison of the boiler water pH trend charts shows that the boiler water pH value fluctuated significantly before chemical dosing, but was controlled within the standard range. After chemical dosing, the boiler water pH value stabilized between 9.0 and 9.5, with more stable data operation and smaller fluctuations. The expected value can be further achieved through adjustments.

[0067] 2. According to the requirements of GB / T12145-2016 "Water and Steam Quality of Thermal Power Generating Units and Steam Power Equipment", the standard value for the conductivity of boiler water in the steam drum boiler is less than 30 μS / cm. Figure 2 The comparison of the boiler water conductivity trend charts shows that the boiler water conductivity was unstable and high before the chemical addition, but decreased and stabilized at around 10-15 μS / cm after the chemical addition, which is better than the national standard.

[0068] 3. According to the requirements of GB / T12145-2016 "Water and Steam Quality of Thermal Power Generating Units and Steam Power Equipment", the standard value of silica in boiler water of steam drum boiler is less than 2 mg / L. Figure 3The comparison of the boiler water silica trend charts shows that before the chemical dosing, the boiler water silica concentration was around 2 mg / L under conditions of high blowdown volume, sometimes even failing to meet standards. After stabilization with the boiler energy-saving scale inhibitor, the boiler water silica concentration not only decreased the blowdown rate but also exceeded national standards. The reduction in boiler water silica significantly lowers the silicon content in the boiler water, thus reducing silicon carried by steam.

[0069] 4. According to the requirements of GB / T12145-2016 "Water and Steam Quality of Thermal Power Generating Units and Steam Power Equipment", the standard value for silica in superheated steam is less than 15 ug / kg, and the expected value is less than 10 ug / kg. Figure 4 The comparison of the superheated steam silica trend charts shows that before the chemical dosing, the steam silica content was too high, and some indicators were not up to standard. After the chemical dosing stabilized, the steam silica content met national standards and reached the expected value. By effectively reducing the silica content in the steam, the steam quality was effectively improved, the occurrence of salt accumulation was effectively avoided, and the steam turbine was made to operate more safely, stably, efficiently, and for longer periods.

[0070] 5. Economic benefit accounting:

[0071] (1) Dosage

[0072]

[0073] The designed dosage concentration is 2-6 ppm, and the calculated value is 4 ppm.

[0074] The daily dosage is: 135t / h × 24h × 4ppm / 1000 = 12.96kg;

[0075] The monthly dosage is: 12.96 kg × 30 = 388.8 kg;

[0076] The annual dosage is: 12.96kg × 365 = 4665.6kg.

[0077] (2) Reduced sewage discharge

[0078] The reduction in sewage discharge is shown in the table below:

[0079]

[0080]

[0081] (3) Economic benefits

[0082] The wastewater parameters of the high-temperature and high-pressure boiler are 316℃ and 10.5MPa. According to the table above, the annual wastewater saving is 27,072 tons. The economic analysis of the above wastewater can be converted into: 1. the same amount of ambient temperature makeup demineralized water; 2. the amount of low-pressure steam generated by the corresponding heat.

[0083] Cost of replenishing demineralized water: 27,072 tons × 20 yuan / ton = 541,000 yuan;

[0084] The unit price of demineralized water is 20 yuan / ton;

[0085] Cost of low-pressure steam generated: 13,638 tons × 150 yuan / ton = 2,046,000 yuan;

[0086] Enthalpy of deionized water: 84.1 kJ / kg;

[0087] Enthalpy of low-pressure saturated steam (0.6 MPa saturation): 2762.7 kJ / kg;

[0088] Wastewater enthalpy: 1433.5 kJ / kg;

[0089] The converted low-pressure steam volume is: (1433.5-84.1)×27072 / (2762.7-84.1)=13638(t)

[0090] The unit price of low-pressure steam is 150 yuan / ton.

[0091] As mentioned above, the economic benefits of using a phosphorus-free dosing system to reduce the discharge rate are as follows:

[0092] 54.1+204.6=258.7 (10,000 yuan);

[0093] The cost of the boiler energy-saving scale inhibitor is: 4.7 × 4.5 = 21.2 (ten thousand yuan);

[0094] The total economic benefit is: 258.7 - 21.2 = 237.5 (ten thousand yuan).

[0095] (4) Environmental benefits

[0096] Carbon emission reduction: (1433.5-84.1)×27072×0.11 / 1000=4018(tCO2)

[0097] After using this boiler energy-saving scale inhibitor, the blowdown rate of the dry quenching coke boiler dropped from 3.2% to about 0.8%, reducing the annual blowdown by 27,072 tons, which translates to a reduction of 4,018 tons of CO2 in carbon emissions. The energy-saving and carbon-reducing effects are significant.

[0098] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions claimed by the present invention.

Claims

1. An environmentally friendly boiler energy-saving scale inhibitor, characterized in that: The components of the environmentally friendly boiler energy-saving scale inhibitor include: ethanolamine, cyclohexylamine, sodium sarcosinate, sodium isopropylbenzenesulfonate, dioctyl sulfosuccinate, and sodium hydroxide.

2. The environmentally friendly boiler energy-saving scale inhibitor according to claim 1, characterized in that: By weight, the components of the environmentally friendly boiler energy-saving scale inhibitor include: 50-150 parts of ethanolamine, 40-100 parts of cyclohexylamine, 1-10 parts of sodium sarcosinate, 1-10 parts of sodium isopropylbenzenesulfonate, 1-5 parts of dioctyl sulfosuccinate, 5-15 parts of sodium hydroxide, and 700-850 parts of water.

3. The environmentally friendly boiler energy-saving scale inhibitor according to claim 1, characterized in that: The components of the environmentally friendly boiler energy-saving scale inhibitor, by weight, include: 120 parts ethanolamine, 60 parts cyclohexylamine, 1 part sodium sarcosinate, 4 parts sodium isopropylbenzenesulfonate, 1 part dioctyl sulfosuccinate, 10 parts sodium hydroxide, and 800 parts water.

4. The preparation method of the environmentally friendly boiler energy-saving scale inhibitor according to any one of claims 1-3, characterized in that: Includes the following steps: (1) Add water to the reaction vessel, then add sodium hydroxide and stir until well mixed; (2) Add ethanolamine, cyclohexylamine, sodium sarcosinate, sodium isopropylbenzenesulfonate and dioctyl sulfosuccinate to the reactor in sequence and stir evenly to obtain an environmentally friendly boiler energy-saving scale inhibitor.

5. The preparation method according to claim 4, characterized in that: The temperature is controlled at 10-30℃ during the stirring process in steps (1) and (2).

6. The preparation method according to claim 4, characterized in that: The environmentally friendly boiler energy-saving scale inhibitor has a solid content of 2-4% after drying, and the pH value of the redissolved solution is 11-12, and the density is 1.0-1.

1.

7. The application of the environmentally friendly boiler energy-saving scale inhibitor according to any one of claims 1-3 in the treatment of boiler boiler water.

8. The application according to claim 7, characterized in that: The concentration of the environmentally friendly boiler energy-saving scale inhibitor is 1-10 ppm.

9. The application according to claim 7, characterized in that: The boiler in question is a dry-quenched coke boiler.

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