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

Abstract

The invention discloses an environment-friendly boiler energy-saving scale inhibitor as well as a preparation method and application thereof. The environment-friendly energy-saving boiler scale inhibitor is prepared from ethanolamine, cyclohexylamine, sodium sarcosinate, sodium cumenesulfonate, sulfonated dioctyl succinate and sodium hydroxide. The use method is simple, the boiler water conductivity can be reduced, the pollution discharge rate is reduced, the steam quality is effectively improved, the salt deposition phenomenon is avoided, a steam turbine can operate more safely, stably and efficiently for a long period, meanwhile, the cost can be greatly saved, and the preparation method is simple. Therefore, the environment-friendly boiler energy-saving scale inhibitor has a wide application prospect.

Description

Technical Field

[0001] The invention belongs to the field of boiler water treatment agents, and in particular relates to an environmentally friendly boiler energy-saving scale inhibitor and a preparation method and application thereof. Background Art

[0002] When water is heated in the 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 state in the boiler, solid matter will be formed. If it is suspended in the boiler water, it is called "water slag", and if it is deposited on the heating surface, it is called "scale". In order to prevent the formation of scale and attachments, prevent scaling, corrosion and steam-water co-evaporation of boiler thermal equipment during boiler operation, and ensure safe, efficient, economical and environmentally friendly operation of the boiler, it is necessary to strengthen the water treatment in the boiler to ensure that the boiler water quality meets national standards.

[0003] At present, CDQ boilers use trisodium phosphate as a scale inhibitor for boiler water treatment, which belongs to inorganic salts. Dimethyl ketoxime is used as an auxiliary deoxidizer for boiler feed water. After the two agents are added to the boiler, the salt content of the boiler water is increased, resulting in an increase in the conductivity of the boiler water. In order to maintain the conductivity of the boiler water within the national standard control range (≤150μs / cm), it is necessary to increase the continuous discharge and strengthen the fixed discharge. The large amount of boiler water discharged not only increases the boiler feed water volume, but also takes away a lot of heat from the boiler, resulting in a decrease in the thermal efficiency of the boiler. At the same time, trisodium phosphate has a "hidden" phenomenon when the boiler load changes greatly, and it is difficult to control the phosphate ion within the standard range (2-6mg / l). When the phosphate ion concentration is too high or too low, there is a problem of secondary phosphate scaling, which buries a great hidden danger to the safe operation of the boiler. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an environmentally friendly boiler energy-saving scale inhibitor and its preparation method and application, which can improve the thermal efficiency of the boiler, is phosphorus-free and environmentally friendly, can improve the quality of steam and boiler water, and has a simple preparation method.

[0005] The present invention intends to adopt the following technical solutions:

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

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

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

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

[0010] (1) Add water into a reaction kettle, then add sodium hydroxide and stir evenly;

[0011] (2) Then, ethanolamine, cyclohexylamine, sodium sarcosinate, sodium cumene sulfonate, and dioctyl sulfosuccinate are sequentially added to the reaction kettle and stirred evenly to obtain a boiler energy-saving scale inhibitor.

[0012] Furthermore, the temperature of the stirring is controlled at 10-30°C throughout the whole process.

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

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

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

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

[0017] Furthermore, the environmentally friendly boiler energy-saving scale inhibitor can improve the thermal efficiency of the boiler, improve the quality of steam and boiler water, and reduce the sewage discharge 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 sewage discharge rate to below 1%, reduce boiler sewage discharge 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, the conductivity of boiler water is low, and the salt content of superheated steam is low.

[0022] 4. The boiler energy-saving scale inhibitor of the present invention can be coated on metal surfaces such as steam turbine impellers and boiler tubes, thereby extending their overhaul cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1This is a comparison chart of drum boiler water pH index data trends;

[0024] Figure 2 This is a comparison chart of the data trend of the drum boiler water conductivity index;

[0025] Figure 3 This is a comparison chart of the silica index data trend of drum boiler water;

[0026] Figure 4 This is a comparison chart of superheated steam silica index data trends. DETAILED DESCRIPTION

[0027] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiment.

[0028] Example 1

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

[0030] (1) Add 800 kg of deionized water into a reaction kettle, then add 10 kg of sodium hydroxide and stir evenly;

[0031] (2) 120 kg of ethanolamine, 60 kg of cyclohexylamine, 1 kg of sodium sarcosinate, 4 kg of sodium cumene sulfonate, and 1 kg of dioctyl sulfosuccinate were added to the reactor in sequence, and stirred evenly. The temperature was controlled at 10-30° C. throughout the process to obtain a boiler energy-saving scale inhibitor.

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

[0033] Example 2

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

[0035] 1. Usage

[0036] The use of boiler energy-saving antiscalant is as follows:

[0037] The dosing ratio of the dosing tank is 1:14 (drug: desalted water). Water should be added first and then the drug should be added. The flow rate of desalted water should not be too high, as it will cause the drug to produce foam. The normal concentration of the drug is 3-5ppm.

[0038] 2. Testing indicators

[0039] At different periods (June 8, 2024 to June 18, 2024), the change trend charts of boiler water pH value, boiler water conductivity, boiler water silica and steam silica were measured before and after the use of boiler energy-saving scale inhibitor.

[0040] The brief detection steps of each indicator are as follows:

[0041] 1. Spectrophotometry - Determination steps of trace silicon content:

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

[0043] ⑴ Use a pipette to measure a certain amount of water sample, place it in a 200mL polyethylene beaker, and use a burette to dilute it to 50.00mL with water.

[0044] ⑵ Add 1.00mL hydrochloric acid solution and 2.00mL ammonium molybdate solution, mix well, and let stand for 5 minutes.

[0045] ⑶ Add 1.00 mL of oxalic acid solution and mix well.

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

[0047] 5. Use a spectrophotometer, with the reagent blank as the reference, and measure the absorbance at a wavelength of 810 nm using a 10 cm cuvette. The mass of silica can be obtained from the calibration curve or calculated using the regression equation.

[0048] 2. Spectrophotometry - Determination steps of constant silicon content:

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

[0050] ⑴ Use a pipette to measure a certain amount of filtered water sample, place it in a 50mL colorimetric tube, and dilute it to the scale with water.

[0051] ⑵ Add 1.00mL hydrochloric acid solution and 2.00mL ammonium molybdate solution, mix well, and let stand for 5 minutes.

[0052] ⑶ Add 1.50 mL of oxalic acid solution and mix well.

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

[0054] 5. Use a spectrophotometer, with the reagent blank as the reference, and measure the absorbance at a wavelength of 640nm using a 1cm cuvette. The mass of silicon dioxide can be obtained from the calibration curve or calculated using the regression equation.

[0055] 3. Steps for measuring conductivity in water (DDSJ-308F user manual):

[0056] Reference standard GB / T 6908-2018

[0057] ⑴ Clean the electrode with pure water, dry it gently with filter paper, rinse it with the solution to be tested two to three times, and then put it into the solution to be tested;

[0058] ⑵Wait for the data to stabilize, and then read the measurement results.

[0059] 4. Steps for determining pH in water (instructions for use of pHS-3E):

[0060] Reference standard GB / T 6904-2008

[0061] ⑴ Rinse the electrode with the solution to be tested two or three times, and then place it in the solution to be tested;

[0062] ⑵Wait for the data to stabilize, and then read the measurement results;

[0063] ⑶ In the measurement state, press the mode key "mV / pH" to switch the display to mV value or pH value.

[0064] 3. Test results

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

[0066] 1. According to the requirements of GBT12145-2016 "Water and Steam Quality for Thermal Power Generators and Steam Power Equipment", the pH standard value of drum boiler water is 9.0-10.0, and the expected value is 9.5-9.7. Figure 1 Comparing the boiler water pH trend chart shown, the pH value of the boiler water fluctuated greatly before adding the drug, and the pH was controlled within the standard value range. After the addition of the drug stabilized, the pH of the boiler water basically stabilized between 9.0-9.5. The data ran more smoothly with less fluctuation, and the expected value can be further achieved through debugging.

[0067] 2. According to the requirements of GBT12145-2016 "Water and Steam Quality for Thermal Power Generators and Steam Power Equipment", the standard value of the conductivity of drum boiler water is less than 30uS / cm. Figure 2 Comparing the boiler water conductivity trend chart shown in the figure, the boiler water conductivity was unstable and high before adding chemicals, and decreased after adding chemicals, and stabilized at around 10-15us / cm, which is better than the national standard.

[0068] 3. According to the requirements of GBT12145-2016 "Water and Steam Quality for Thermal Power Generators and Steam Power Equipment", the standard value of silica in drum boiler water is less than 2 mg / L. Figure 3Compared with the trend chart of silica in boiler water shown in the figure, before adding the agent, the silica in boiler water was running at about 2 mg / L when the discharge volume was large, and sometimes the index would fail to meet the standard. After the boiler energy-saving scale inhibitor was added and stabilized, the silica in boiler water not only reduced the discharge rate, but also the index was better than the national standard. The reduction of silica in boiler water greatly reduced the silicon content in boiler water and reduced the silicon carried by steam.

[0069] 4. According to the requirements of GBT12145-2016 "Water and Steam Quality for Thermal Power Generators and Steam Power Equipment", the standard value of silica in superheated steam is less than 15ug / kg, and the expected value is less than 10ug / kg. Figure 4 The silica trend chart of superheated steam is shown in the figure. Before adding the chemical, the silica content of steam was too high and some indicators were unqualified. After the chemical was stabilized, the silica value of steam met the national standard and reached the expected value. By effectively reducing the silica content in steam, the steam quality is effectively improved, and the occurrence of salt accumulation is effectively avoided, making the steam turbine safer, more stable, more efficient, and longer-term operation.

[0070] 5. Economic benefit calculation:

[0071] (1) Dosage

[0072]

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

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

[0075] Monthly dosage: 12.96kg×30=388.8kg;

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

[0077] (2) Reduction in pollutant discharge

[0078] The reduction in pollutant discharge is shown in the following table:

[0079]

[0080]

[0081] (3) Economic Benefits

[0082] The parameters of wastewater discharged from high temperature and high pressure boilers are 316℃ and 10.5MPa. According to the above table, the annual wastewater saving is 27072t. The economic analysis of the above wastewater can be converted into: 1. The same amount of room temperature supplementary demineralized water; 2. The amount of low-pressure steam generated by the corresponding heat.

[0083] Desalted water supplement cost: 27072t×20 yuan / t=541,000 yuan;

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

[0085] Cost of low-pressure steam generated: 13,638t × 150 yuan / ton = 2.046 million yuan;

[0086] Desalted water enthalpy: 84.1 kJ / kg;

[0087] Low-pressure saturated steam (0.6MPa saturated) enthalpy value: 2762.7kJ / kg;

[0088] Enthalpy of sewage: 1433.5kJ / kg;

[0089] Converted low-pressure steam volume: (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:

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

[0093] The cost of boiler energy-saving scale inhibitor is: 4.7×4.5=21.2 (10,000 yuan);

[0094] The total economic benefits are: 258.7-21.2=237.5 (10,000 yuan).

[0095] (4) Environmental benefits

[0096] Reduction of carbon emissions: (1433.5-84.1)×27072×0.11 / 1000=4018(tCO2)

[0097] After the dry quenching boiler used this boiler energy-saving scale inhibitor, the emission rate dropped from 3.2% to about 0.8%, reducing the annual emission by 27,072 tons, which is equivalent to reducing carbon emissions by 4,018 tons of CO2, with significant energy-saving and carbon-reduction effects.

[0098] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to replace some of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions claimed to be protected 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 cumene sulfonate, dioctyl sulfosuccinate and sodium hydroxide.

2. The environmentally friendly boiler energy-saving scale inhibitor according to claim 1 is characterized by: The components of the environmentally friendly boiler energy-saving scale inhibitor include, by weight: 50-150 parts of ethanolamine, 40-100 parts of cyclohexylamine, 1-10 parts of sodium sarcosinate, 1-10 parts of sodium cumene sulfonate, 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 is characterized in that: The components of the environmentally friendly boiler energy-saving scale inhibitor include, by weight: 120 parts of ethanolamine, 60 parts of cyclohexylamine, 1 part of sodium sarcosinate, 4 parts of sodium cumene sulfonate, 1 part of dioctyl sulfosuccinate, 10 parts of sodium hydroxide, and 800 parts of water.

4. The method for preparing the environmentally friendly boiler energy-saving antiscalant according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) Add water into a reaction kettle, then add sodium hydroxide and stir evenly; (2) Then, ethanolamine, cyclohexylamine, sodium sarcosinate, sodium cumene sulfonate, and dioctyl sulfosuccinate are sequentially added to the reaction kettle and stirred 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°C during the whole stirring process.

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, a pH value of the solution after redilution of 11-12, and a density of 1.0-1.

1.

7. Use of the environmentally friendly boiler energy-saving antiscalant according to any one of claims 1 to 3 in treating boiler water.

8. The use according to claim 7, characterized in that: The environmentally friendly boiler energy-saving antiscalant is used at a concentration of 1-10 ppm.

9. The use according to claim 7, characterized in that: The boiler is a coke dry quenching boiler.

10. The use according to claim 7, characterized in that: The environmentally friendly boiler energy-saving scale inhibitor can improve the thermal efficiency of the boiler, improve the quality of steam and boiler water, and reduce the sewage discharge rate.

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