Desulfurization slurry additives, desulfurization slurry and its preparation method
By adding carrageenan and tributyl phosphate to the desulfurization slurry, the surface tension is increased and a dense layer is formed, which solves the problem of CPM release caused by the evaporation of the desulfurization slurry and achieves efficient desulfurization and dust removal.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GUODIAN SCI & TECH RES INST
- Filing Date
- 2024-09-19
- Publication Date
- 2026-06-30
AI Technical Summary
In existing wet flue gas desulfurization systems, the desulfurization slurry droplets evaporate upon heating, leading to the release of volatile, easily decomposed, and hydrophobic components. This results in a high content of condensable particulate matter (CPM), which affects the dust removal efficiency.
Carrageenan and tributyl phosphate were used as additives for desulfurization slurry. Carrageenan increased the surface tension, and tributyl phosphate formed a dense layer on the surface of the droplets, reducing evaporation and the release of volatile components.
It effectively reduces the CPM content in the desulfurization flue gas discharged from the WFGD system, improves dust removal efficiency, and reduces the concentration of soluble ions, thus providing economic benefits.
Smart Images
Figure CN119075657B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of environmental protection technology, specifically to a desulfurization slurry additive, a desulfurization slurry, and a method for preparing the desulfurization slurry. Background Technology
[0002] Flue gas emitted from coal-fired power plants contains a large number of pollutants, including sulfur dioxide (SO2), nitrogen oxides (NOx), and condensable particulate matter (CPM). Currently, the common dust removal route for flue gas is dry electrostatic precipitator – desulfurization-co-precipitator – wet electrostatic precipitator, aiming to achieve high-efficiency dust removal and ultra-low emissions. The desulfurization-co-precipitator is generally carried out in a wet flue gas desulfurization (WFGD) system.
[0003] Although the WFGD system can remove CPM from flue gas to a certain extent, during the actual dust removal process, the high-temperature flue gas and the low-temperature desulfurization slurry come into countercurrent contact, causing the desulfurization slurry droplets to evaporate due to heat. This evaporation releases some volatile, easily decomposable, and hydrophobic components, which often re-enter the gas phase as CPM or CPM precursors. This results in a high CPM content in the desulfurized flue gas discharged from the WFGD system, leading to poor CPM removal efficiency of the aforementioned dust removal route. Summary of the Invention
[0004] The purpose of this invention is to overcome the problem of high CPM content in the desulfurized flue gas discharged from wet flue gas desulfurization systems in the prior art, and to provide a desulfurization slurry additive, a desulfurization slurry, and a method for preparing the desulfurization slurry.
[0005] To achieve the above objectives, the first aspect of the present invention provides a desulfurization slurry additive, the desulfurization slurry additive comprising carrageenan and tributyl phosphate.
[0006] In the embodiments of this application, the molar ratio of carrageenan to tributyl phosphate in the desulfurization slurry additive is (1:10) to (10:1).
[0007] In the embodiments of this application, the molar ratio of carrageenan to tributyl phosphate in the desulfurization slurry additive is (1:3) to (3:1).
[0008] In this embodiment of the application, the gel strength of carrageenan in the desulfurization slurry additive is greater than or equal to 1500 g / cm³. 2 .
[0009] In this embodiment of the application, the moisture content of the carrageenan in the desulfurization slurry additive is less than 4.0%; the ash content of the carrageenan in the desulfurization slurry additive is less than 1.6% by mass; and the drying weight loss of the carrageenan in the desulfurization slurry additive is less than 10% within 4 hours at 105°C.
[0010] In the embodiments of this application, the lead content in the carrageenan of the desulfurization slurry additive is less than 0.002% by mass; the arsenic content in the carrageenan of the desulfurization slurry additive is less than 0.0002% by mass.
[0011] The second aspect of this application provides a desulfurization slurry, which is obtained by mixing limestone slurry and the desulfurization slurry additives provided in the first aspect of this application.
[0012] In the embodiments of this application, the total molar concentration of carrageenan and tributyl phosphate in the desulfurization slurry is 2 mmol / L to 16 mmol / L.
[0013] In the embodiments of this application, the total molar concentration of carrageenan and tributyl phosphate in the desulfurization slurry is 4 mmol / L to 16 mmol / L.
[0014] A third aspect of this application provides a method for preparing the desulfurization slurry of the second aspect, the method comprising:
[0015] Carrageenan was added to the limestone slurry to obtain the first solution;
[0016] Tributyl phosphate was added to the first solution to obtain a desulfurization slurry.
[0017] The desulfurization slurry additive provided by the above technical solution includes carrageenan and tributyl phosphate. Carrageenan can increase the surface tension of the desulfurization slurry, while tributyl phosphate can form a dense layer on the surface of the slurry droplets, thus slowing down the rate at which the desulfurization slurry transforms from the liquid phase to the gas phase, reducing the evaporation rate of the desulfurization slurry, and consequently reducing the release of volatile, decomposable, and hydrophobic components in the desulfurization slurry. This, in turn, can reduce the CPM content in the desulfurization flue gas discharged from the WFGD system.
[0018] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description
[0019] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings:
[0020] Figure 1 The schematic diagram illustrates a process flow diagram of a desulfurization slurry preparation method according to an embodiment of this application. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of this application and are not intended to limit the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0022] If the embodiments of this application involve descriptions such as "first" or "second," such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Furthermore, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.
[0023] As described in the background section, flue gas emitted from coal-fired power plants contains a large number of pollutants, including sulfur dioxide (SO2), nitrogen oxides (NOx), and condensable particulate matter (CPM). Currently, the common dust removal route for flue gas is dry electrostatic precipitator – desulfurization-co-precipitator – wet electrostatic precipitator to achieve high-efficiency dust removal and ultra-low emissions. Desulfurization-co-precipitator is generally carried out in wet flue gas desulfurization (WFGD) systems. Although WFGD systems can remove CPM from flue gas to a certain extent, in the actual dust removal process of WFGD systems, high-temperature flue gas comes into countercurrent contact with low-temperature desulfurization slurry, causing the desulfurization slurry droplets to evaporate due to heat. This evaporation of the desulfurization slurry droplets releases some volatile, easily decomposable, and hydrophobic components. These released components often re-enter the gas phase in the form of CPM or CPM precursors; that is, the desulfurization slurry can be considered to release CPM and CPM precursors. Although some CPM or CPM precursors entering the gas phase may condense heterogeneously on the surface of filterable particulate matter (FPM), they often continue to undergo metathesis reactions with related components in the FPM, releasing CPM or CPM precursors again. Therefore, the desulfurization flue gas discharged from the WFGD system has a high CPM content, mostly in gaseous form. Since gaseous CPM in the desulfurization flue gas is difficult to remove by subsequent wet electrostatic precipitators, the aforementioned dust removal route is ineffective in removing CPM.
[0024] To address this, this application provides a desulfurization slurry additive that can be used to reduce the CPM content in the desulfurization flue gas discharged from a WFGD system. In this application embodiment, the desulfurization slurry additive includes carrageenan and tributyl phosphate.
[0025] Carrageenan, also known as agar, is a hydrophilic colloid composed of calcium, potassium, sodium, or ammonium salts of a polysaccharide sulfate ester consisting of galactose and dehydrated galactose. In the embodiments of this application, carrageenan can be used to increase the surface tension of desulfurization slurry.
[0026] Furthermore, the carrageenan used in the desulfurization slurry additive can have the following parameters:
[0027] (1) Gel strength greater than or equal to 1500 g / cm 2 (2) Humidity less than 4.0%; (3) Ash content less than 1.6%; (4) Loss on drying less than 10% within 4 hours at 105℃; (5) Lead content less than 0.002%; (6) Arsenic content less than 0.0002%.
[0028] Tributyl phosphate, chemical formula C 12 H 27 O4P or (C4H9)3PO4 is an organic compound. In the prior art, tributyl phosphate is commonly used as an industrial defoamer, which can defoam the formed foam film in an unstable state, thereby rapidly defoaming. In the embodiments of this application, tributyl phosphate can be used to form a dense layer on the surface of the droplets of desulfurization slurry.
[0029] In the desulfurization slurry additive provided in this application embodiment, the molar ratio of carrageenan to tributyl phosphate is (1:10) to (10:1). For example, it can be 1:10, 1:3, 2:5, 1:2, 1:1, 2:1, 5:2, 3:1, 10:1, or any ratio between the listed ratios. Preferably, the molar ratio of carrageenan to tributyl phosphate is (1:3) to (3:1). For example, it can be 1:3, 2:5, 1:2, 1:1, 2:1, 5:2, 3:1, or any ratio between the listed ratios. More preferably, the molar ratio of carrageenan to tributyl phosphate is 1:1.
[0030] It is understood that the desulfurization slurry additive provided in this application includes carrageenan and tributyl phosphate. Since carrageenan can increase the surface tension of the desulfurization slurry, and tributyl phosphate can form a dense layer on the surface of the slurry droplets, the rate at which the desulfurization slurry transforms from the liquid phase to the gas phase can be slowed down, reducing the evaporation of the desulfurization slurry. This, in turn, reduces the release of volatile, decomposable, and hydrophobic components from the desulfurization slurry, thereby lowering the CPM content in the desulfurization flue gas discharged from the WFGD system.
[0031] It is understandable that reducing the release of volatile, decomposable, and hydrophobic components in the desulfurization slurry is equivalent to preventing the conversion of these components into CPM and CPM precursors. This inhibits the release of CPM or CPM precursors from the desulfurization slurry, thus reducing the CPM content in the desulfurization flue gas discharged from the WFGD system. Volatile and decomposable components can be, for example, soluble ions dissolved in the desulfurization slurry (such as SO42-). 2- Ca 2+ Na + and Cl - )wait.
[0032] Furthermore, the desulfurization slurry additive provided in this application embodiment can reduce the CPM content in the desulfurization flue gas discharged from the WFGD system without modifying the equipment, thereby improving the removal effect of the dust removal route on CPM. Moreover, based on the desulfurization slurry additive provided in this application embodiment, the WFGD system can achieve both desulfurization and good removal of CPM, resulting in significant economic benefits.
[0033] Based on the desulfurization slurry additives provided in the above embodiments of this application, this application also provides a desulfurization slurry, which is obtained by mixing limestone slurry and the desulfurization slurry additives in the above embodiments of this application. This desulfurization slurry can be transported to an absorption tower and sprayed down from the top of the absorption tower to contact the flue gas in a counter-current flow.
[0034] In the desulfurization slurry provided in this application embodiment, the total molar concentration of carrageenan and tributyl phosphate is 2 mmol / L to 16 mmol / L. For example, it can be 2 mmol / L, 4 mmol / L, 6 mmol / L, 8 mmol / L, 10 mmol / L, 12 mmol / L, 14 mmol / L, 16 mmol / L, or any concentration between the listed concentrations. Preferably, the total molar concentration of carrageenan and tributyl phosphate is 4 mmol / L to 16 mmol / L. For example, it can be 4 mmol / L, 6 mmol / L, 8 mmol / L, 10 mmol / L, 12 mmol / L, 16 mmol / L, or any concentration between the listed concentrations. More preferably, the total molar concentration of carrageenan and tributyl phosphate is 8 mmol / L.
[0035] That is, in a preferred embodiment, the total molar concentration of carrageenan and tributyl phosphate in the desulfurization slurry is 8 mmol / L, and the molar ratio of carrageenan to tributyl phosphate is 1:1.
[0036] It is understood that the desulfurization slurry provided in the embodiments of this application is obtained by mixing limestone slurry and the desulfurization slurry additives in the above embodiments of this application. Since the desulfurization slurry additives include carrageenan and tributyl phosphate, and carrageenan can increase the surface tension of the desulfurization slurry, while tributyl phosphate can form a dense layer on the surface of the droplets in the desulfurization slurry, the addition of the desulfurization slurry additives can slow down the rate at which the desulfurization slurry transforms from the liquid phase to the gas phase, reduce the evaporation of the desulfurization slurry, and thus reduce the release of volatile components, easily decomposable components, and hydrophobic components in the desulfurization slurry. Therefore, using the desulfurization slurry provided in the embodiments of this application can reduce the CPM content in the desulfurization flue gas discharged from the WFGD system.
[0037] Based on the desulfurization slurry provided in the above embodiments of this application, this application also provides a method for preparing desulfurization slurry, which can be used to prepare the desulfurization slurry in the above embodiments. Figure 1 As shown, the desulfurization slurry preparation method may include the following steps:
[0038] Step 101: Add carrageenan to the limestone slurry to obtain the first solution.
[0039] The reaction temperature corresponding to this step can be the temperature of the limestone slurry when applied to the absorption tower, for example, it can be 35℃~45℃.
[0040] Considering that tributyl phosphate is slightly soluble in water, if it is added first, it will float on the surface of the limestone slurry, preventing the formation of a dense layer on the surface of the desulfurization slurry droplets and hindering the subsequent mixing of carrageenan and limestone slurry. Therefore, in this embodiment, carrageenan is added to the limestone slurry first, and after thorough stirring, tributyl phosphate is added.
[0041] Step 102: Add tributyl phosphate to the first solution to obtain desulfurization slurry.
[0042] Similarly, the reaction temperature corresponding to this step can be the temperature of the limestone slurry when applied to the absorption tower, for example, 35℃~45℃.
[0043] It is understood that the desulfurization slurry preparation method provided in the embodiments of this application can be used to prepare the desulfurization slurry provided in the above embodiments of this application. Furthermore, since the desulfurization slurry is obtained by mixing limestone slurry and the desulfurization slurry additives in the above embodiments of this application, including carrageenan and tributyl phosphate, carrageenan can increase the surface tension of the desulfurization slurry. Simultaneously, tributyl phosphate can form a dense layer on the surface of the droplets of the desulfurization slurry, thereby slowing down the rate at which the desulfurization slurry transforms from the liquid phase to the gas phase, reducing the evaporation of the desulfurization slurry, and consequently reducing the release of volatile components, easily decomposable components, and hydrophobic components in the desulfurization slurry. Therefore, the desulfurization slurry prepared using the preparation method provided in the embodiments of this application can reduce the CPM content in the desulfurization flue gas discharged from the WFGD system.
[0044] The solutions provided by the embodiments of this application are described below with reference to specific examples and comparative examples. It should be understood that the following embodiments are merely some specific implementation methods and do not imply an improper limitation on the solutions of this application.
[0045] Comparative Example 1
[0046] No desulfurization slurry additives are added to the limestone slurry.
[0047] The SO2 concentration in the inlet flue gas of the WFGD system was 2860 mg / Nm³. 3 The inlet flue gas flow rate is 10 L / min; the inlet flue gas temperature is 120℃; the temperature of the limestone slurry without desulfurization slurry additives is 40℃; and the mass concentration of limestone in the limestone slurry without desulfurization slurry additives is 15%.
[0048] The surface tension coefficient of limestone slurry without desulfurization additives was measured to be 35.6 × 10⁻⁶ using a surface tension meter. -3 The measured average CPM emission concentration of the WFGD system over 100 minutes was 9.5 mg / Nm³. 3 .
[0049] Example 1
[0050] First, carrageenan is added to the limestone slurry and stirred until homogeneous. Then, tributyl phosphate is added to obtain the desulfurization slurry. In the desulfurization slurry, the total molar concentration of carrageenan and tributyl phosphate is 2 mmol / L, of which the concentration of carrageenan is 1 mmol / L and the concentration of tributyl phosphate is 1 mmol / L.
[0051] The SO2 concentration in the inlet flue gas of the WFGD system was 2860 mg / Nm³. 3 The inlet flue gas flow rate is 10 L / min; the inlet flue gas temperature is 120℃; the desulfurization slurry temperature is 40℃; and the mass concentration of limestone in the desulfurization slurry is 15%.
[0052] The surface tension coefficient of the desulfurization slurry was measured to be 36.5 × 10⁻⁶ using a surface tension meter. -3 The measured average CPM emission concentration of the WFGD system over 100 minutes was 7.9 mg / Nm³. 3 Compared with Comparative Example 1, the CPM emission concentration decreased by 17%.
[0053] Example 2
[0054] First, carrageenan is added to the limestone slurry and stirred until homogeneous. Then, tributyl phosphate is added to obtain the desulfurization slurry. In the desulfurization slurry, the total molar concentration of carrageenan and tributyl phosphate is 4 mmol / L, of which the concentration of carrageenan is 2 mmol / L and the concentration of tributyl phosphate is 2 mmol / L.
[0055] The SO2 concentration in the inlet flue gas of the WFGD system was 2860 mg / Nm³. 3 The inlet flue gas flow rate is 10 L / min; the inlet flue gas temperature is 120℃; the desulfurization slurry temperature is 40℃; and the mass concentration of limestone in the desulfurization slurry is 15%.
[0056] The surface tension coefficient of the desulfurization slurry was measured to be 37.8 × 10⁻⁶ using a surface tension meter. -3 The measured average CPM emission concentration of the WFGD system over 100 minutes was 7.1 mg / Nm³. 3 Compared with Comparative Example 1, the CPM emission concentration was reduced by 25%.
[0057] Example 3
[0058] First, carrageenan is added to the limestone slurry and stirred until homogeneous. Then, tributyl phosphate is added to obtain the desulfurization slurry. In the desulfurization slurry, the total molar concentration of carrageenan and tributyl phosphate is 8 mmol / L, of which the concentration of carrageenan is 4 mmol / L and the concentration of tributyl phosphate is 4 mmol / L.
[0059] The SO2 concentration in the inlet flue gas of the WFGD system was 2860 mg / Nm³. 3 The inlet flue gas flow rate is 10 L / min; the inlet flue gas temperature is 120℃; the desulfurization slurry temperature is 40℃; and the mass concentration of limestone in the desulfurization slurry is 15%.
[0060] The surface tension coefficient of the desulfurization slurry was measured to be 38.9 × 10⁻⁶ using a surface tension meter. -3 The measured average CPM emission concentration of the WFGD system over 100 minutes was 6.9 mg / Nm³. 3 Compared with Comparative Example 1, the CPM emission concentration was reduced by 27%.
[0061] Example 4
[0062] First, carrageenan is added to the limestone slurry and stirred until homogeneous. Then, tributyl phosphate is added to obtain the desulfurization slurry. In the desulfurization slurry, the total molar concentration of carrageenan and tributyl phosphate is 12 mmol / L, of which the concentration of carrageenan is 6 mmol / L and the concentration of tributyl phosphate is 6 mmol / L.
[0063] The SO2 concentration in the inlet flue gas of the WFGD system was 2860 mg / Nm³. 3 The inlet flue gas flow rate is 10 L / min; the inlet flue gas temperature is 120℃; the desulfurization slurry temperature is 40℃; and the mass concentration of limestone in the desulfurization slurry is 15%.
[0064] The surface tension coefficient of the desulfurization slurry was measured to be 39.0 × 10⁻⁶ using a surface tension meter. -3 N / m, the measured average CPM emission concentration of the WFGD system over 100 minutes was 7 mg / Nm. 3 Compared with Comparative Example 1, the CPM emission concentration was reduced by 26%.
[0065] Example 5
[0066] First, carrageenan is added to the limestone slurry and stirred until homogeneous. Then, tributyl phosphate is added to obtain the desulfurization slurry. In the desulfurization slurry, the total molar concentration of carrageenan and tributyl phosphate is 16 mmol / L, of which the concentration of carrageenan is 8 mmol / L and the concentration of tributyl phosphate is 8 mmol / L.
[0067] The SO2 concentration in the inlet flue gas of the WFGD system was 2860 mg / Nm³. 3 The inlet flue gas flow rate is 10 L / min; the inlet flue gas temperature is 120℃; the desulfurization slurry temperature is 40℃; and the mass concentration of limestone in the desulfurization slurry is 15%.
[0068] The surface tension coefficient of the desulfurization slurry was measured to be 39.1 × 10⁻⁶ using a surface tension meter. -3 The measured average CPM emission concentration of the WFGD system over 100 minutes was 7.1 mg / Nm³. 3 Compared with Comparative Example 1, the CPM emission concentration was reduced by 25%.
[0069] Example 6
[0070] First, carrageenan is added to the limestone slurry and stirred until homogeneous. Then, tributyl phosphate is added to obtain the desulfurization slurry. In the desulfurization slurry, the total molar concentration of carrageenan and tributyl phosphate is 8 mmol / L, of which the concentration of carrageenan is 2 mmol / L and the concentration of tributyl phosphate is 6 mmol / L.
[0071] The SO2 concentration in the inlet flue gas of the WFGD system was 2860 mg / Nm³. 3 The inlet flue gas flow rate is 10 L / min; the inlet flue gas temperature is 120℃; the desulfurization slurry temperature is 40℃; and the mass concentration of limestone in the desulfurization slurry is 15%.
[0072] The surface tension coefficient of the desulfurization slurry was measured to be 37.8 × 10⁻⁶ using a surface tension meter. -3 The measured average CPM emission concentration of the WFGD system over 100 minutes was 7.2 mg / Nm³. 3 Compared with Comparative Example 1, the CPM emission concentration was reduced by 24%.
[0073] Example 7
[0074] First, carrageenan is added to the limestone slurry and stirred until homogeneous. Then, tributyl phosphate is added to obtain the desulfurization slurry. In the desulfurization slurry, the total molar concentration of carrageenan and tributyl phosphate is 8 mmol / L, of which the concentration of carrageenan is 3 mmol / L and the concentration of tributyl phosphate is 5 mmol / L.
[0075] The SO2 concentration in the inlet flue gas of the WFGD system was 2860 mg / Nm³. 3 The inlet flue gas flow rate is 10 L / min; the inlet flue gas temperature is 120℃; the desulfurization slurry temperature is 40℃; and the mass concentration of limestone in the desulfurization slurry is 15%.
[0076] The surface tension coefficient of the desulfurization slurry was measured to be 38.4 × 10⁻⁶ using a surface tension meter.-3 The measured average CPM emission concentration of the WFGD system over 100 minutes was 7.1 mg / Nm³. 3 Compared with Comparative Example 1, the CPM emission concentration was reduced by 25%.
[0077] Example 8
[0078] First, carrageenan is added to the limestone slurry and stirred until homogeneous. Then, tributyl phosphate is added to obtain the desulfurization slurry. In the desulfurization slurry, the total molar concentration of carrageenan and tributyl phosphate is 8 mmol / L, of which the concentration of carrageenan is 5 mmol / L and the concentration of tributyl phosphate is 3 mmol / L.
[0079] The SO2 concentration in the inlet flue gas of the WFGD system was 2860 mg / Nm³. 3 The inlet flue gas flow rate is 10 L / min; the inlet flue gas temperature is 120℃; the desulfurization slurry temperature is 40℃; and the mass concentration of limestone in the desulfurization slurry is 15%.
[0080] The surface tension coefficient of the desulfurization slurry was measured to be 39.0 × 10⁻⁶ using a surface tension meter. -3 N / m, the measured average CPM emission concentration of the WFGD system over 100 minutes was 7.0 mg / Nm. 3 Compared with Comparative Example 1, the CPM emission concentration was reduced by 26%.
[0081] Example 9
[0082] First, carrageenan is added to the limestone slurry and stirred until homogeneous. Then, tributyl phosphate is added to obtain the desulfurization slurry. In the desulfurization slurry, the total molar concentration of carrageenan and tributyl phosphate is 8 mmol / L, of which the concentration of carrageenan is 6 mmol / L and the concentration of tributyl phosphate is 2 mmol / L.
[0083] The SO2 concentration in the inlet flue gas of the WFGD system was 2860 mg / Nm³. 3 The inlet flue gas flow rate is 10 L / min; the inlet flue gas temperature is 120℃; the desulfurization slurry temperature is 40℃; and the mass concentration of limestone in the desulfurization slurry is 15%.
[0084] The surface tension coefficient of the desulfurization slurry was measured to be 39.0 × 10⁻⁶ using a surface tension meter. -3 The measured average CPM emission concentration of the WFGD system over 100 minutes was 7.3 mg / Nm³. 3 Compared with Comparative Example 1, the CPM emission concentration was reduced by 23%.
[0085] Carrageenan used in Examples 1-9 was purchased from the same batch, with the following parameters: gel strength greater than or equal to 1500 g / cm³.2 Humidity less than 4.0%; ash content less than 1.6% by mass; weight loss after drying at 105℃ for 4 hours less than 10%; lead content less than 0.002% by mass; arsenic content less than 0.0002% by mass.
[0086] Furthermore, under the conditions of Example 3, the mass concentration of soluble ions in the CPM discharged from the WFGD system was detected. Compared with Comparative Example 1, SO42- 2- Ca 2+ Na + and Cl - The reduction rates can reach 23%, 31%, 23%, and 25%, respectively.
[0087] As can be seen from the above, the solutions provided in the embodiments of this application can effectively reduce the CPM content in the desulfurized flue gas discharged from the WFGD system. Among them, Example 3 has the best effect, with a CPM emission concentration reduction rate of up to 27%. At the same time, the solutions provided in the embodiments of this application can also reduce the mass concentration of soluble ions in CPM.
[0088] It should also be noted that the endpoints and any values of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of the various ranges, the endpoint values of the various ranges and individual point values, and individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.
[0089] The terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.
[0090] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.
Claims
1. A desulfurization slurry additive, characterized in that, The desulfurization slurry additive is used to mix with limestone slurry to form desulfurization slurry, and the desulfurization slurry additive includes carrageenan and tributyl phosphate; The carrageenan is used to increase the surface tension of the desulfurization slurry, and the tributyl phosphate is used to form a dense layer on the surface of the droplets of the desulfurization slurry. In the desulfurization slurry additive, the molar ratio of carrageenan to tributyl phosphate is (1:3) to (3:1). In the desulfurization slurry, the total molar concentration of carrageenan and tributyl phosphate is 4 mmol / L to 12 mmol / L.
2. The desulfurization slurry additive according to claim 1, characterized in that, The gel strength of the carrageenan in the desulfurization slurry additive is greater than or equal to 1500 g / cm³. 2 .
3. The desulfurization slurry additive according to claim 1, characterized in that, The moisture content of the carrageenan in the desulfurization slurry additive is less than 4.0%; The ash content of the carrageenan in the desulfurization slurry additive is less than 1.6% by mass. At 105°C, the carrageenan in the desulfurization slurry additive has a drying weight loss of less than 10% within 4 hours.
4. The desulfurization slurry additive according to claim 1, characterized in that, The lead content in the carrageenan of the desulfurization slurry additive is less than 0.002% by mass; The arsenic content in the carrageenan in the desulfurization slurry additive is less than 0.0002%.
5. A desulfurization slurry, characterized in that, The desulfurization slurry is obtained by mixing limestone slurry and the desulfurization slurry additive according to any one of claims 1-4.
6. A method for preparing the desulfurization slurry according to claim 5, characterized in that, The preparation method includes: Carrageenan was added to the limestone slurry to obtain the first solution; Tributyl phosphate was added to the first solution to obtain a desulfurization slurry.