Nano liquid caustic soda for absorbing acid gas and semi-dry method waste incineration flue gas deacidification system and method

Abstract

The invention relates to the technical field of waste incineration deacidification, and particularly discloses nano liquid caustic soda for absorbing acid gas and a semi-dry method waste incineration flue gas deacidification system and method. The nano caustic soda liquid comprises nano calcium hydroxide, alkaline metal ions and carbonate ions, so that the reaction rate with acid gas can be greatly increased, and the fly ash amount can be reduced; meanwhile, the nano caustic soda liquid is highly adaptive to a deacidification system, so that the equipment blockage risk and the maintenance cost can be remarkably reduced; in addition, due to the high reaction efficiency of the nano caustic soda liquid and the strong adaptability of the nano caustic soda liquid to a deacidification system, the comprehensive operation cost is lower, and zero dust pollution can be realized. According to the semi-dry method waste incineration flue gas deacidification system and method, the dilution proportion and the adding amount of the nano caustic soda liquid can be precisely regulated and controlled, different flue gas acid loads are matched, deacidification efficiency maximization and operation cost minimization are achieved, and the problems that an existing waste incineration process is low in deacidification efficiency, large in fly ash amount and high in system maintenance cost are solved.

Description

Technical Field

[0001] This application relates to the field of waste incineration deacidification technology, and in particular to a nano-liquid alkali and semi-dry waste incineration flue gas deacidification system and method for absorbing acidic gases. Background Technology

[0002] With the development of the waste incineration industry, incineration conditions have changed significantly: the proportion of co-incineration of existing waste and high-calorific-value waste is gradually increasing, while the proportion of municipal solid waste incineration is continuously decreasing. Under these conditions, the content of acidic gases in the flue gas produced by incineration increases exponentially, significantly increasing the operating pressure on the acid removal equipment in the flue gas treatment system. Furthermore, the consumption of acid removal consumables has surged, and fly ash production has increased simultaneously, posing a significant challenge to the stable production and operation of incineration plants. Therefore, it is urgent to optimize existing acid removal technologies to adapt to the current operating conditions.

[0003] Currently, slaked lime is commonly used as a deacidifying agent in waste-to-energy plants. However, the deacidification technology using slaked lime still has the following insurmountable drawbacks: First, the deacidification reaction efficiency is relatively low. To ensure that the emission of acidic gases in the flue gas meets the standards, a large amount of slaked lime needs to be consumed, directly leading to high usage costs of deacidification agents. Second, slaked lime generates a large amount of fly ash during use, which not only increases the cost and difficulty of subsequent fly ash treatment but also poses a risk of secondary pollution. Third, during the transportation and addition of slaked lime slurry, long-term operation can easily lead to deposition and scaling in the pipelines, causing pipeline blockage, seriously affecting the stable operation of the deacidification system, and also increasing the frequency of equipment maintenance and maintenance costs, significantly increasing the workload of operation and maintenance personnel.

[0004] In summary, the existing technology using slaked lime as a deacidifying agent in waste incineration flue gas desulfurization systems is no longer suitable for the changing needs of current waste incineration operations. Its low reaction efficiency, high fly ash production, easy equipment clogging, and high overall operating costs have become key technical bottlenecks restricting the environmental compliance and stable, efficient operation of waste-to-energy power plants. Therefore, it is essential to develop a novel flue gas deacidification technology that addresses these technical shortcomings and is adapted to current incineration conditions, thereby improving the efficiency of the deacidification system and reducing operating costs and environmental risks. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide a nano-liquid alkali and semi-dry waste incineration flue gas deacidification system and method for absorbing acidic gases, in order to solve the problems of low deacidification efficiency, large fly ash volume and high system maintenance cost in existing waste incineration processes.

[0006] To achieve the above-mentioned technical objectives, this application provides a nano-liquid alkali for absorbing acidic gases, the nano-liquid alkali comprising nano-sized calcium hydroxide, alkaline metal ions, and carbonate ions.

[0007] Furthermore, the solid content of the nano-liquid alkali is 24%~26%; the mass percentage of acid-insoluble matter in the nano-liquid alkali is ≤0.02%; and the pH value of the nano-liquid alkali is ≥12.

[0008] This application provides a semi-dry waste incineration flue gas deacidification system, including a storage device, a conveying device, and a deacidification reaction device;

[0009] The storage device is used to store nano-liquid alkali or nano-liquid alkali dilution prepared from nano-liquid alkali; the conveying device is used to convey nano-liquid alkali or nano-liquid alkali dilution to the deacidification reaction device; the deacidification reaction device is used to supply nano-liquid alkali or nano-liquid alkali dilution to react with acidic gas.

[0010] Furthermore, it also includes a dilution device; the dilution device is connected to the storage device and the deacidification reaction device respectively through a conveying device; the dilution device is used to dilute the nano-liquid alkali.

[0011] Furthermore, it also includes a monitoring device; the monitoring device is electrically connected to the deacidification reaction device and is used to monitor the concentration of acidic gas, the amount of nano-liquid alkali used, and the amount of fly ash generated inside the deacidification reaction device.

[0012] This application provides a method for desulfurization of flue gas from waste incineration, which is implemented using a semi-dry flue gas desulfurization system.

[0013] Further, the method includes the following steps: placing nano-liquid alkali or nano-liquid alkali dilution in a storage device, starting the semi-dry waste incineration flue gas deacidification system, and conveying the nano-liquid alkali or nano-liquid alkali dilution to the deacidification reaction device via a conveying device, so that the nano-liquid alkali or nano-liquid alkali dilution comes into contact with acidic gas and reacts.

[0014] Furthermore, before the conveying device delivers the nano-liquid alkali to the deacidification reaction device, it performs a dilution operation on the nano-liquid alkali, including the following steps: using a dilution device to mix the nano-liquid alkali with water to obtain a diluted nano-liquid alkali solution; the conveying device delivers the diluted nano-liquid alkali solution to the deacidification reaction device.

[0015] Furthermore, the nano-liquid alkali dilution solution is obtained by mixing nano-liquid alkali with water at a mass ratio of 1:3 to 4.

[0016] Furthermore, the monitoring device is used to monitor the concentration of acidic gas, the amount of nano-liquid alkali used, and the amount of fly ash generated in the deacidification reaction unit; when the concentration of acidic gas does not meet the emission standards, the amount of nano-liquid alkali or nano-liquid alkali dilution in the deacidification reaction unit is increased.

[0017] In summary, this application provides a nano-liquid alkali for absorbing acidic gases. The nano-liquid alkali comprises nano-sized calcium hydroxide, alkaline metal ions, and carbonate ions. The nano-liquid alkali consists of micron-sized particles with low solid content and a large specific surface area, which significantly increases the reaction rate with acidic gases, reduces the amount of deacidifying agent used, and lowers the subsequent treatment cost of fly ash. Simultaneously, the nano-liquid alkali is highly compatible with deacidification systems, reducing the frequency of periodic sludge removal from the pulping system and the workload of cleaning the vibrating screen, effectively preventing system overflow. Furthermore, there is no significant scaling on the inner wall of the pulping tank, no blockage in the filter screen of the conveying pipeline, and stable operation of the atomizer, significantly reducing the risk of equipment blockage and maintenance costs, while also reducing the workload of operation and maintenance personnel. In addition, the nano-liquid alkali has advantages such as high reaction efficiency, low reagent consumption, and low fly ash treatment cost, resulting in lower overall operating costs and achieving zero dust pollution, thus avoiding the secondary pollution risk of traditional deacidification processes at the source.

[0018] This application provides a semi-dry waste incineration flue gas deacidification system and method, as well as a waste incineration flue gas deacidification method using this system. The system includes a storage device, a conveying device, and a deacidification reaction device; the storage device includes an iron tank or a plastic tank for storing nano-liquid alkali or a diluted solution of nano-liquid alkali; the conveying device is used to transport the nano-liquid alkali or the diluted solution to the deacidification reaction device; the deacidification reaction device is used to supply the nano-liquid alkali or the diluted solution to react with acidic gases. The semi-dry waste incineration flue gas deacidification system and method can precisely adjust the dilution ratio and dosage of nano-liquid alkali to match different flue gas acidity loads, maximizing deacidification efficiency and minimizing operating costs, thereby improving the overall emission level of waste incineration power plants.

[0019] Compared with existing technologies, this solution uses nano-liquid alkali as a deacidifying agent, which has higher treatment efficiency, less fly ash generation, and greater economic practicality. Detailed Implementation

[0020] The technical solutions of the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments in this application specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection claimed in this application.

[0021] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship shown, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] Unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0023] The raw materials used in this invention are not particularly restricted in their source; they can be purchased on the market or prepared using conventional methods known to those skilled in the art.

[0024] This application provides a nano-liquid alkali for absorbing acidic gases. The nano-liquid alkali includes nano-sized calcium hydroxide, alkaline metal ions, and carbonate ions.

[0025] In some embodiments, the solid content of the nano-liquid alkali is 24%~26%; the mass percentage of acid-insoluble matter in the nano-liquid alkali is ≤0.02%; and the pH value of the nano-liquid alkali is ≥12.

[0026] It should be noted that nano-liquid alkali consists of micron-sized particles with low solid content and large specific surface area, which can significantly improve the reaction rate with acidic gases, reduce the amount of deacidifying agent used, and lower the subsequent treatment cost of fly ash. Nano-liquid alkali has advantages such as high reaction efficiency, low reagent consumption, and low fly ash treatment cost, resulting in lower overall operating costs. It can also achieve zero dust pollution, avoiding the secondary pollution risk of traditional deacidification processes from the source.

[0027] This application provides a semi-dry waste incineration flue gas deacidification system, including a storage device, a conveying device, and a deacidification reaction device;

[0028] The storage device is used to store nano-liquid alkali or nano-liquid alkali dilution prepared from nano-liquid alkali; the conveying device is used to convey nano-liquid alkali or nano-liquid alkali dilution to the deacidification reaction device; the deacidification reaction device is used to supply nano-liquid alkali or nano-liquid alkali dilution to react with acidic gas.

[0029] It should be noted that nano liquid alkali is highly compatible with the system. During use, it can reduce the frequency of regular sewage discharge and the workload of cleaning the vibrating screen in the pulping system, effectively avoid system overflow problems, and there is no obvious scaling on the inner wall of the pulping tank, no blockage of the filter screen in the conveying pipeline, and stable operation of the atomizer. It can significantly reduce the risk of equipment blockage and maintenance costs, while also reducing the workload of operation and maintenance personnel.

[0030] In some embodiments, a dilution device is also included; the dilution device is connected to the storage device and the deacidification reaction device respectively via a conveying device; the dilution device is used to dilute the nano-liquid alkali.

[0031] In some embodiments, a monitoring device is also included; the monitoring device is electrically connected to the deacidification reaction device and is used to monitor the concentration of acidic gas, the amount of nano-liquid alkali used, and the amount of fly ash generated inside the deacidification reaction device.

[0032] This application provides a method for desulfurizing flue gas from waste incineration, which is implemented using a semi-dry waste incineration flue gas desulfurization system.

[0033] In some embodiments, the method includes the following steps: placing nano-liquid alkali or nano-liquid alkali dilution in a storage device, starting a semi-dry waste incineration flue gas deacidification system, and conveying nano-liquid alkali or nano-liquid alkali dilution to a deacidification reaction device via a conveying device, so that the nano-liquid alkali or nano-liquid alkali dilution comes into contact with acidic gas and reacts.

[0034] In some embodiments, before the conveying device delivers the nano-liquid alkali to the deacidification reaction device, it performs a dilution operation on the nano-liquid alkali, including the following steps: using a dilution device to mix the nano-liquid alkali with water to obtain a diluted nano-liquid alkali solution; and the conveying device delivers the diluted nano-liquid alkali solution to the deacidification reaction device.

[0035] In some embodiments, the nano-liquid alkali dilution is obtained by mixing nano-liquid alkali and water at a mass ratio of 1:3 to 4.

[0036] In some embodiments, the monitoring device is used to monitor the concentration of acidic gas, the amount of nano-liquid alkali used, and the amount of fly ash generated in the deacidification reaction device; when the concentration of acidic gas does not meet the emission standards, the amount of nano-liquid alkali or nano-liquid alkali dilution in the deacidification reaction device is increased.

[0037] The applicant further provides the following specific embodiments to describe the present invention. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0038] Example 1

[0039] This embodiment provides a nano-liquid alkali, a novel high-efficiency deacidifying agent and a calcium-based absorbent, with nano-sized Ca(OH)2 as its main component. The nano-liquid alkali uses calcium as the base material, with some alkali metals and carbonate ions as auxiliary materials. Through activation and modification with various functional components, it acquires strong alkaline properties and possesses the ability to efficiently absorb acidic gases. The physical and chemical properties of the nano-liquid alkali are as follows: appearance: milky white liquid; solid content: 25%±1%; acid-insoluble matter ≤0.02%; pH value ≥12; it can be stored in iron cans or plastic drums and transported by tank truck.

[0040] Example 2

[0041] This embodiment provides a semi-dry waste incineration flue gas deacidification system, which includes an alkali storage device, a dilution device, a conveying device, and a deacidification reaction device;

[0042] Storage devices include iron cans or plastic containers for storing nano-liquid alkali or nano-liquid alkali dilution;

[0043] The dilution device is used to mix and dilute the nano-liquid alkali with water at a preset ratio to prepare a nano-liquid alkali dilution solution that meets the requirements of the deacidification reaction.

[0044] The conveying device is connected to the outlet of the dilution device and the inlet of the deacidification reaction device, respectively, and is used to convey the nano-liquid alkali dilution to the deacidification reaction device;

[0045] The deacidification reaction device is connected to the main flue gas emission pipeline of the waste incinerator through a pipeline, providing sufficient space for the nano-liquid alkali dilution to contact and react with the acidic gases (mainly SO2 and HCl) in the flue gas, thus efficiently removing the acidic gases. In addition, the deacidification reaction device is also equipped with an injection device, which is equipped with an automatic regulating valve and a flow meter to automatically adjust the flow rate according to the changes in the concentration of acidic gases.

[0046] The monitoring device is connected to the flue gas pipeline and reagent delivery pipeline at the outlet of the deacidification reaction unit. It is used to collect and monitor the emission concentrations of SO2 and HCl in the flue gas in real time, as well as the real-time consumption of nano-liquid alkali dilution solution and the amount of fly ash generated.

[0047] Example 3

[0048] This embodiment provides a method for desulfurizing flue gas from waste incineration. The method is implemented using a semi-dry waste incineration flue gas desulfurization system and includes the following steps:

[0049] Step S1, Preparation of nano-liquid alkali dilution: Using nano-liquid alkali as a deacidifying agent, take the nano-liquid alkali from the storage device and place it in the dilution device, mix the nano-liquid alkali and water at a mass ratio of 1:3.5 to obtain nano-liquid alkali dilution, the alkalinity of the nano-liquid alkali dilution is 5~6;

[0050] Step S2, Start the deacidification system: Start the semi-dry waste incineration flue gas deacidification system of Example 2. The nano-liquid alkali dilution solution in the dilution device is transported to the deacidification reaction device through the conveying device, so that the nano-liquid alkali dilution solution can fully contact and react with acidic gases such as SO2 and HCl in the waste incineration flue gas until the SO2 and HCl concentrations reach the emission standards. At the same time, the consumption of nano-liquid alkali dilution solution, the amount of fly ash generated, and the SO2 and HCl concentrations at the flue gas emission outlets of the incinerators (including No. 1 to No. 7) are monitored in real time through the monitoring device. The monitoring data are detailed in Tables 1 and 2.

[0051] Comparative Example 1

[0052] This embodiment provides a method for desulfurizing flue gas from waste incineration. The method is implemented using a semi-dry waste incineration flue gas desulfurization system and includes the following steps:

[0053] Step S1, preparing deacidifying agent dilution: using calcium hydroxide as the deacidifying agent, take calcium hydroxide from the storage device and place it in the dilution device, mix calcium hydroxide and water at a volume ratio of 1:9 to obtain deacidifying agent dilution; the alkalinity of the deacidifying agent dilution is 5~6, and its calcium content is consistent with that of the nano liquid alkali dilution.

[0054] Step S2, Start the deacidification system: Start the semi-dry waste incineration flue gas deacidification system of Example 2. The deacidifying agent dilution liquid in the dilution device is transported to the deacidification reaction device through the conveying device, so that the deacidifying agent dilution liquid can fully contact and react with acidic gases such as SO2 and HCl in the waste incineration flue gas. At the same time, the consumption of deacidifying agent dilution liquid, the amount of fly ash generated, and the concentration of SO2 and HCl at the emission outlet in the flue gas are monitored through the monitoring device. The monitoring data are detailed in Tables 1 and 2.

[0055] Table 1. Application effects and data of nano-liquid alkali dilution and deacidifying agent dilution

[0056]

[0057] Table 2. Application effects and data of nano-liquid alkali diluent and deacidifying agent diluent

[0058]

[0059] Based on the data in Tables 1 and 2, it can be seen that the nano-liquid alkali dilution can significantly reduce the amount of fly ash generated. For example, the amount of fly ash generated in Example 3 in Table 1 is significantly lower than that in Comparative Example 1, and the amount of fly ash generated in Example 3 in Table 2 is significantly lower than that in Comparative Example 1, thereby reducing the cost of fly ash treatment. The overall comprehensive cost has also decreased. The comprehensive cost of treating flue gas per ton of waste in Table 1 decreased by 5.3%, and the comprehensive cost of treating flue gas per ton of waste in Table 2 decreased by 9.36%.

[0060] The above are merely preferred embodiments of this application and are not intended to limit the present invention. Although this application has been described in detail with reference to examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A nano-liquid alkali for absorbing acidic gases, characterized in that, The nano-liquid alkali includes nano-sized calcium hydroxide, alkaline metal ions, and carbonate ions.

2. The nano-liquid alkali for absorbing acidic gases according to claim 1, characterized in that, The solid content of the nano-liquid alkali is 24% to 26%; the mass percentage of acid-insoluble matter in the nano-liquid alkali is ≤0.02%; and the pH value of the nano-liquid alkali is ≥12.

3. A semi-dry waste incineration flue gas desulfurization system, characterized in that, Includes storage devices, conveying devices, and deacidification reaction devices; The storage device is used to store the nano liquid alkali according to any one of claims 1 to 2 or the nano liquid alkali dilution prepared according to any one of claims 1 to 2; The conveying device is used to convey the nano-liquid alkali or the nano-liquid alkali dilution to the deacidification reaction device; The deacidification reaction device is used to supply the nano-liquid alkali or the nano-liquid alkali dilution to react with acidic gas.

4. The semi-dry waste incineration flue gas desulfurization system according to claim 3, characterized in that, It also includes a dilution device; The dilution device is connected to the storage device and the deacidification reaction device via the conveying device; the dilution device is used to dilute the nano-liquid alkali.

5. The semi-dry waste incineration flue gas desulfurization system according to any one of claims 3 to 4, characterized in that, It also includes monitoring devices; The monitoring device is electrically connected to the deacidification reaction device and is used to monitor the concentration of acidic gas, the amount of nano-liquid alkali used, and the amount of fly ash generated inside the deacidification reaction device.

6. A method for desulfurizing flue gas from waste incineration, characterized in that, The waste incineration flue gas desulfurization method is implemented using the semi-dry waste incineration flue gas desulfurization system described in any one of claims 3 to 5.

7. The method for desulfurizing flue gas from waste incineration according to claim 6, characterized in that, Includes the following steps: The nano-liquid alkali or its diluted form is placed in a storage device. The semi-dry waste incineration flue gas deacidification system is started, and the nano-liquid alkali or its diluted form is transported to the deacidification reaction device via a conveying device, so that the nano-liquid alkali or its diluted form comes into contact with the acidic gas and reacts.

8. The method for desulfurizing flue gas from waste incineration according to claim 7, characterized in that, Before the conveying device delivers the nano-liquid alkali to the deacidification reaction device, it performs a dilution operation on the nano-liquid alkali, including the following steps: using a dilution device to mix the nano-liquid alkali with water to obtain a diluted nano-liquid alkali solution; the conveying device delivers the diluted nano-liquid alkali solution to the deacidification reaction device.

9. The method for desulfurizing flue gas from waste incineration according to any one of claims 7 to 8, characterized in that, The nano-liquid alkali dilution solution is obtained by mixing nano-liquid alkali and water at a mass ratio of 1:3~4.

10. The method for desulfurizing flue gas from waste incineration according to claim 7, characterized in that, The monitoring device is used to monitor the concentration of acidic gas, the amount of nano-liquid alkali used, and the amount of fly ash generated in the deacidification reaction device; when the concentration of acidic gas does not meet the emission standards, the amount of nano-liquid alkali or nano-liquid alkali dilution in the deacidification reaction device is increased.

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