Flue gas deacidification fly ash treatment process

Abstract

The invention relates to the technical field of environmental engineering, in particular to a flue gas deacidification fly ash treatment process, which is characterized in that a deacidification agent used in a deacidification step is a powdery deacidification agent, and the specific content is as follows: flue gas at an outlet of an incinerator is introduced into a desulfurization tower; the method comprises the following steps: detecting the concentration and flow of hydrogen chloride and sulfur dioxide in flue gas before the flue gas enters a desulfurization tower, setting the initial addition amount of a powdery deacidification agent according to the concentration and flow of the hydrogen chloride and the sulfur dioxide in the flue gas, and ensuring that the initial addition amount of the deacidification agent is that the molar weight of the deacidification agent is 1.1-1.5 times of the sum of the molar weight of hydrogen chloride and 2.1-2.6 times of the molar weight of sulfur dioxide within the initial time period of 30 minutes; then detecting the concentration of acid gas in the flue gas at the outlet of the desulfurization tower and adjusting the dosage of a deacidification agent to ensure that the flue gas emission requirement is met; the flue gas treatment device has the advantage of reducing the fly ash amount during flue gas treatment.

Description

Technical Field

[0001] The present application relates to the technical field of environmental engineering, and in particular to a flue gas deacidification fly ash treatment process. Background Art

[0002] In recent years, with the gradual increase of domestic waste, the treatment of fly ash from waste incineration has become a focus of attention. The waste incineration treatment process generally involves first burning the waste in an incinerator, and then the flue gas generated by the incineration enters the desulfurization tower through the outlet of the incinerator for desulfurization by a semi-dry method. In the desulfurization tower, the deacidification agent reacts with the acidic gas in the flue gas, mainly hydrogen chloride and sulfur dioxide, so that the hydrogen chloride and sulfur dioxide in the flue gas reach a content below the emission standard. The deacidification agent is lime slurry. The flue gas after desulfurization enters the dust removal device for dust removal, and the flue gas after dust removal enters the emission device after denitrification treatment by the denitrification device.

[0003] Among them, the flue gas temperature at the outlet of the incinerator can reach 220°C. After desulfurization by lime slurry in the desulfurization tower, the temperature drops to about 155°C. After dust removal by bag filter, the temperature further drops to about 150°C. The temperature of the existing traditional denitrification process needs to be around 175°C. Therefore, it is necessary to add a steam step to heat the flue gas before denitrification. And when lime slurry is used for desulfurization, after the lime slurry is dried, it produces a large amount of very fine smoke dust. These smoke dusts enter the bag filter for dust removal together with the flue gas, which increases the amount of fly ash. According to the test, the amount of fly ash in the dust removal device can reach 4.5%, and the cost of handling the fly ash is also high. Under comprehensive circumstances, the cost of waste incineration treatment is relatively high. Summary of the invention

[0004] In order to reduce the amount of fly ash during flue gas treatment, the present application provides a flue gas deacidification fly ash treatment process.

[0005] In the first aspect, the present application provides a flue gas deacidification fly ash treatment process, which adopts the following technical scheme: A flue gas deacidification fly ash treatment process, wherein the deacidification agent used in the deacidification step is a powdered deacidification agent, and the powdered deacidification agent is sodium bicarbonate or a mixture of sodium bicarbonate and sodium hydroxide, and the specific contents are as follows: S1. Pass the flue gas from the incinerator outlet into the desulfurization tower, and detect the concentration and flow rate of hydrogen chloride and sulfur dioxide in the flue gas before entering the desulfurization tower, and set the initial addition amount of the powdered deacidification agent accordingly to ensure that within the initial 30-minute period, the initial addition amount of the deacidification agent is: the molar amount of the deacidification agent is the sum of 1.1-1.5 times the molar amount of hydrogen chloride and 2.1-2.6 times the molar amount of sulfur dioxide; then detect the concentration of acidic gas in the flue gas at the outlet of the desulfurization tower, and adjust the amount of the deacidification agent according to the detection data to ensure that the flue gas emission requirements are met; S2. The deacidified flue gas is passed through a bag filter for dust removal and then subjected to denitrification treatment.

[0006] By adopting the above technical scheme, the flue gas deacidification process of the present application abandons the traditional semi-dry desulfurization process, and by using the spraying method to spray the powdered deacidification agent, the amount of the deacidification agent can be reduced; and it can avoid the situation that the temperature of the waste incineration flue gas drops too much due to the high water content of the lime slurry and the increase of its water temperature, and the flue gas needs to be heated separately, which actively responds to the national call for energy conservation and emission reduction, and also reduces the cost of domestic waste treatment; and because most of the powdered deacidification agent will fall to the bottom of the desulfurization tower for collection, there is no need for a bag dust collector for dust removal, thereby greatly reducing the amount of fly ash and reducing the cost of domestic waste treatment; The powdered deacidification agent of the present application can achieve a good deacidification effect using sodium bicarbonate, a mixture of sodium bicarbonate and sodium hydroxide. After the lime slurry is sprayed into the desulfurization tower, it is easy to produce a large amount of tiny dust, which is mixed into the flue gas. When the flue gas enters the bag filter, it becomes a part of the fly ash, thereby increasing the amount of fly ash and increasing the processing cost of fly ash. The powdered deacidification agent has large particles, and its volume is not easy to change before and after the reaction. After the reaction, it falls to the bottom of the desulfurization tower and is not easy to follow the flue gas into the bag filter, so that the increase in fly ash is small. The inventor also shows that the use of sodium bicarbonate is lower than that of lime slurry, which is also conducive to reducing the increase in fly ash. And the addition of sodium hydroxide can make the reaction activity of the deacidification agent better, so that its addition amount is reduced, and the increase in its fly ash amount is further reduced.

[0007] Preferably, the deacidifying agent is injected into the desulfurization tower through multiple channels.

[0008] By adopting the above technical solution, the injection rate of the deacidifying agent can be increased through multiple channels, and the desulfurization tower is in a negative pressure state, which has a suction effect on the deacidifying agent. In actual operation, it is not easy to cause congestion in the channels.

[0009] Preferably, the deacidification agent is a porous carrier composite alkali, and the porous carrier composite alkali is prepared by loading the deacidification agent on a porous carrier.

[0010] By adopting the above technical solution, since the powdered deacidification agent is in granular form, its particle surface is easy to react, while the inside of the particle has a small contact surface with the acidic gas, so it reacts slowly or cannot react with the acidic gas, resulting in waste of acidic agents and increased costs. On this basis, the inventors of the present application prepared a porous carrier composite alkali, which can increase the contact area between the deacidification agent and the flue gas, make the deacidification agent react more fully, further reduce the amount of deacidification agent used, and save costs.

[0011] Preferably, the porous carrier is one or more of vermiculite, sepiolite and montmorillonite.

[0012] By adopting the above technical scheme, vermiculite is a layered structured magnesium-containing hydrous aluminosilicate secondary metamorphic mineral, sepiolite is a fibrous hydrated magnesium silicate mineral, and montmorillonite is a layered mineral composed of extremely fine particles of hydrous aluminosilicate; vermiculite, sepiolite and montmorillonite all have large specific surface areas and internal pores, and can construct fine gas diffusion channels; using them as porous carriers, on the one hand, they can allow a large amount of deacidification agents to be adsorbed, and on the other hand, the pores they contain can play a certain adsorption role on acidic gases, and then react with the deacidification agents they carry, thereby improving the deacidification efficiency.

[0013] Preferably, the deacidification agent is sodium hydroxide.

[0014] By adopting the above technical solution, due to the limited solubility of sodium bicarbonate in water, the amount of porous carrier required is large, which also increases the cost and the amount of fly ash. On this basis, sodium hydroxide is used as a deacidification agent. The solubility of sodium hydroxide in water is large, which greatly increases the load per unit mass of the porous carrier. Therefore, the amount of porous carrier used can be reduced and the amount of fly ash generated can be reduced. In addition, sodium hydroxide is easy to absorb moisture. By preparing it through this method, the moisture absorption of sodium hydroxide can be reduced, and it is easier to spray and add.

[0015] As a preference: the method of compounding the porous carrier with alkali is as follows: An aqueous solution of a deacidifying agent is prepared, and then a porous carrier is immersed in the aqueous solution of the deacidifying agent, filtered, and then dried or blown dry at a temperature below 45° C. to obtain a porous carrier composite alkali.

[0016] By adopting the above technical solution, the preparation is carried out by infiltration and then drying, which is simple and easy to operate and very easy to achieve, and the reaction with carbon dioxide in the air can be reduced by controlling the drying temperature.

[0017] Preferably, the aqueous solution of the deacidification agent is a saturated solution of a deacidification solvent.

[0018] By adopting the above technical solution, the content of deacidifying agent in the saturated solution is higher, so that the porous carrier can adsorb more deacidifying agent, thereby reducing the amount of porous carrier used, and is also beneficial to reducing the amount of fly ash caused by the use of porous carrier.

[0019] Preferably, the water content of the porous carrier composite alkali is ≤6%.

[0020] By adopting the above technical solution, the porous carrier composite alkali contains a certain amount of water, which can improve its adsorption and dissolution of acidic gases, and then react with the sodium hydroxide loaded on its surface, so as to improve the deacidification efficiency. However, the water content will reduce the flue gas temperature at the outlet of the desulfurization tower. Through the detection of experimental data, the water content of the porous carrier deacidification agent should not exceed 6%.

[0021] Preferably, the average particle size of the porous carrier is 800 mesh to 100 mesh.

[0022] By adopting the above technical solution, the particle size of the porous carrier should not be too large, as it is not conducive to its injection addition, while too small a particle size will easily increase the amount of fly ash. Good technical effects can be obtained within this range.

[0023] In summary, the present application includes at least one of the following beneficial technical effects: 1. The flue gas deacidification process of the present application abandons the traditional semi-dry desulfurization process, and uses a spraying method to spray powdered deacidification agents, which can reduce the amount of deacidification agents used; and can avoid the situation where the temperature of the waste incineration flue gas drops too much due to the high water content of the lime slurry and the increase in its water temperature, and the flue gas needs to be heated separately, which actively responds to the national call for energy conservation and emission reduction, and also reduces the cost of domestic waste treatment; and because most of the powdered deacidification agents will fall to the bottom of the desulfurization tower for collection, there is no need for a bag dust collector for dust removal, thereby greatly reducing the amount of fly ash and reducing the cost of domestic waste treatment.

[0024] 2. Since the powdered deacidification agent is granular, its particle surface is easy to react, but the inside of the particle has a small contact surface with the acidic gas, so it reacts slowly or cannot react with the acidic gas, resulting in waste of acidic agents and increased costs. On this basis, the inventors of the present application prepared a porous carrier composite alkali, which can increase the contact area between the deacidification agent and the flue gas, make the deacidification agent react more fully, further reduce the amount of deacidification agent used, and save costs.

[0025] 3. The flue gas deacidification process of the present application abandons the traditional semi-dry desulfurization process. By using the spraying method to spray the powdered deacidification agent, the dosage of the deacidification agent can be reduced. It can also avoid the situation where the temperature of the waste incineration flue gas drops too much due to the high water content of the lime slurry and the increase in its water temperature, and the flue gas needs to be heated separately. It actively responds to the national call for energy conservation and emission reduction, and also reduces the cost of domestic waste treatment. And because most of the powdered deacidification agent will fall to the bottom of the desulfurization tower for collection, there is no need for a bag filter for dust removal, which greatly reduces the amount of fly ash and further reduces the cost of domestic waste treatment. Ignoring the cost reduction of the deacidification agent, only from the calculation of fly ash treatment and MVR water evaporation, 34.36-41.56 yuan can be saved per ton of domestic waste treatment, and there is no need to set up a steam heating device after the dust bag is removed, which can effectively save energy. DETAILED DESCRIPTION

[0026] The present application is further described in detail below in conjunction with the specific contents.

[0027] raw material The raw materials used in the examples of the present application are all commercially available products, wherein the deacidification agents used are all industrial grade. Example

[0028] Example 1 A domestic waste treatment plant has a rated domestic waste treatment capacity of 100t / d and produces 17500Nm 3 / h, the average concentration of HCl is 500mg / Nm 3 The average concentration of SO2 is 400mg / Nm 3 ; Among them, the flue gas generated by the garbage enters the desulfurization tower through the outlet of the incinerator for deacidification, and the flue gas deacidification fly ash process includes the following steps: S1. The flue gas from the incinerator outlet is passed into the desulfurization tower. After testing, the flue gas temperature at the inlet of the desulfurization tower is 220°C. The concentration and flow rate of hydrogen chloride and sulfur dioxide in the flue gas before entering the desulfurization tower are tested, and the amount of powdered deacidification agent is adjusted accordingly. The powdered deacidification agent is sodium bicarbonate. It is ensured that within a 30-minute period, the initial addition amount of the deacidification agent is: the molar amount of sodium bicarbonate is the sum of 1.3 times the molar amount of hydrogen chloride and 2.5 times the molar amount of sulfur dioxide; then the concentration of acidic gas in the flue gas at the outlet of the desulfurization tower is tested, and the amount of deacidification agent is adjusted according to the data to ensure that the flue gas emission requirements are met; the powdered deacidification agent is sprayed into the desulfurization tower through multiple channels; S2. After the flue gas is deacidified, it passes through a bag filter for dedusting, and then enters a denitrification device for denitrification according to the prior art. It will not be described here in detail. It is known that the temperature required for denitrification is 171-182°C. After testing, the temperature of the flue gas at the outlet of the desulfurization tower after deacidification is 182°C, and after the flue gas is dedusted by the bag filter, the temperature at the inlet of the denitrification device is 176°C, which can meet the temperature required for the denitrification step. There is no need to steam heat the flue gas after dedusting.

[0029] Example 2 A flue gas deacidification fly ash treatment process, which is different from Example 1 in that its deacidification agent is a mixture of sodium bicarbonate and sodium hydroxide. In actual use, sodium bicarbonate and sodium hydroxide can be mixed immediately or added separately. The molar ratio of sodium bicarbonate to sodium hydroxide is 3:1, ensuring that within a 30-minute time period, the initial addition amount of the deacidification agent is: the total molar amount of sodium bicarbonate and sodium hydroxide is the sum of 1.3 times the molar amount of hydrogen chloride and 2.5 times the molar amount of sulfur dioxide, and the concentration of acidic gas in the flue gas at the outlet of the desulfurization tower is detected, and the total amount of sodium bicarbonate and sodium hydroxide is adjusted according to the data to ensure that the flue gas emission requirements are met. The remaining steps are the same as Example 1.

[0030] Example 3 A flue gas deacidification fly ash treatment process, which is different from Example 1 in that its deacidification agent is loaded through a porous carrier, wherein the porous carrier is vermiculite, the deacidification agent is sodium bicarbonate, the average particle size of the porous carrier is 400 mesh, and the preparation method of the porous carrier composite alkali is as follows: at 30°C, a saturated sodium bicarbonate solution is prepared, and then the saturated sodium bicarbonate solution is added to the vermiculite until the vermiculite is just submerged, and after soaking for 10 minutes, the filtrate is filtered, and the filtrate can be reused, and the filtered solid is dried at 40°C to obtain a porous carrier composite alkali; the prepared porous carrier loaded with sodium bicarbonate is used as a deacidification agent in step S1 of Example 1, and the concentration of acidic gas in the flue gas at the outlet of the desulfurization tower is detected, and the amount of the porous carrier composite alkali is adjusted according to the data to ensure that the flue gas emission requirements are met.

[0031] Example 4 A flue gas deacidification fly ash treatment process, which is different from Example 3 in that, when preparing its porous carrier composite alkali, the deacidification agent it carries is sodium hydroxide; the preparation method of the porous carrier composite alkali is as follows: at 30°C, a saturated sodium hydroxide solution is prepared, and then a saturated sodium bicarbonate solution is added to the vermiculite until the vermiculite is just submerged, and after soaking for 10 minutes, the filtrate is filtered, and the filtrate can be reused. The filtered solid is dried at 40°C to obtain a porous carrier composite alkali.

[0032] Example 5 A flue gas deacidification fly ash treatment process is different from Example 4 in that the porous carrier composite alkali is dried to a moisture content of 4% during preparation, and the remaining steps are the same as those of Example 4.

[0033] Example 6 A flue gas deacidification fly ash treatment process is different from Example 4 in that the porous carrier composite alkali is dried to a moisture content of 5% during preparation, and the remaining steps are the same as those of Example 4.

[0034] Example 7 A flue gas deacidification fly ash treatment process is different from Example 4 in that the porous carrier composite alkali is dried to a moisture content of 6% during preparation, and the remaining steps are the same as those of Example 4.

[0035] Example 8 A flue gas deacidification fly ash treatment process, which is different from Example 6 in that the average particle size of its porous carrier vermiculite is 100 mesh, and the remaining steps are the same as Example 6.

[0036] Example 9 A flue gas deacidification fly ash treatment process, which is different from Example 6 in that the average particle size of its porous carrier vermiculite is 800 mesh, and the remaining steps are the same as Example 6.

[0037] Comparative Example Comparative Example 1 A flue gas deacidification fly ash treatment process is different from Example 1 in that it adopts traditional semi-dry desulfurization, the deacidification agent is lime slurry, and then the flue gas is dedusted by a bag filter, and its temperature is raised to 172°C by steam, and the remaining steps are the same as Example 1.

[0038] Performance testing Detection method / test method According to Examples 1-9 and Comparative Example 1, 100 tons of waste incineration flue gas, i.e., the waste treatment amount for one day, was treated respectively, and then the total amount of deacidification agent used was calculated. The test results are shown in Table 1.

[0039] Among them, the deacidification agent of Comparative Example 1 is lime slurry, and Table 1 shows the solid content thereof.

[0040] Table 1 Test results of Examples 1-9 and Comparative Example 1 It is known that the cost of fly ash treatment is at least 1,800 yuan / t, and the price of MVR water evaporation is 80 yuan / t; the inventor pointed out that the price of sodium bicarbonate and sodium hydroxide is relatively high, so it is not provided. However, the inventor pointed out that although the unit price is relatively high for sodium bicarbonate and sodium hydroxide, the overall cost of the deacidification agent is lower than that of using lime slurry due to the large amount of lime slurry used. Ignoring the cost reduction of the deacidification agent, only from the calculation of fly ash treatment and MVR water evaporation, 34.36-41.56 yuan can be saved per ton of domestic waste treatment, and there is no need to set up a steam heating device after the dust bag is removed, which can effectively save energy.

[0041] It can be seen from Examples 1-9 and Comparative Example 1, as well as the test data in Table 1, that the flue gas deacidification process of the present application abandons the traditional semi-dry desulfurization process, and by using a spraying method to spray a powdered deacidification agent, the amount of deacidification agent used can be reduced; and the situation in which the waste incineration flue gas temperature drops too much due to the high water content of the lime slurry and the increase in its water temperature, and the flue gas needs to be heated additionally, is avoided, actively responds to the national call for energy conservation and emission reduction, and reduces the cost of domestic waste treatment; and because most of the powdered deacidification agent will fall to the bottom of the desulfurization tower for collection, there is no need for a bag filter for dust removal, thereby greatly reducing the amount of fly ash and further reducing the cost of domestic waste treatment.

[0042] It can be seen from the test data of Example 1 and Example 2, as well as Comparative Example 1, that the powdered deacidification agent of the present application can achieve a good deacidification effect using sodium bicarbonate, a mixture of sodium bicarbonate and sodium hydroxide. After the lime slurry is sprayed into the desulfurization tower, it is easy to produce a large amount of tiny dust, which is mixed into the flue gas. When the flue gas enters the bag filter, it becomes part of the fly ash, thereby increasing the amount of fly ash and increasing the processing cost of fly ash. The powdered deacidification agent has large particles, and its volume is not easy to change before and after the reaction. After the reaction, it falls to the bottom of the desulfurization tower and is not easy to follow the flue gas into the bag filter, thereby reducing the increase in the amount of fly ash. The inventor also shows that the use of sodium bicarbonate is lower than that of lime slurry, which is also conducive to reducing the increase in fly ash. And the addition of sodium hydroxide can make the reaction activity of the deacidification agent better, thereby reducing its addition amount, and further reducing the increase in its fly ash amount.

[0043] Since the powdered deacidification agent is granular, its particle surface is easy to react, while the inside of the particle has a small contact surface with the acidic gas, so its reaction is slow, or it cannot react with the acidic gas, resulting in waste of acidic agents and increased costs. On this basis, the inventor of the present application prepared a porous carrier composite alkali, first preparing a saturated solution of sodium bicarbonate, then using it to infiltrate a porous carrier, and then drying it, so that the porous carrier composite alkali greatly increases the contact area between sodium bicarbonate and the gas, so that sodium bicarbonate can react with the acidic gas more fully. And the porous carrier is a multi-porous structure with a large surface area, which can construct a fine gas diffusion channel, so that the acidic gas can be adsorbed and the removal efficiency of the acidic gas can be improved. It can be seen from the test data of Example 1 and Example 3. However, due to the limited solubility of sodium bicarbonate in water, the amount of porous carrier required is large, which also increases the cost and increases the amount of fly ash. On this basis, sodium hydroxide is used as a deacidification agent. The solubility of sodium hydroxide in water is relatively large, which greatly increases the load per unit mass of the porous carrier. Therefore, the use of the porous carrier can be reduced and the amount of fly ash generated can be reduced. This can be seen in combination with the test data of Example 4. The inventor pointed out that although the step of adding a porous carrier composite alkali was added, the deacidification agent was fully reacted, and the use of the deacidification agent was reduced. Under the comprehensive cost, the cost is still lower than that of the semi-dry method. In addition, the adsorption of acidic gases by the porous carrier and further reaction can also increase the reaction rate and improve production efficiency.

[0044] On this basis, the porous carrier composite alkali contains a certain amount of water, which can improve its adsorption and dissolution of acidic gases, and then react with the sodium hydroxide loaded on its surface, so as to improve the deacidification efficiency. However, the water content will reduce the flue gas temperature at the outlet of the desulfurization tower. Through the detection of experimental data, the water content of the porous carrier deacidification agent should not exceed 6%. This can be verified by the detection data of Examples 5-7.

[0045] It can be seen from the test data of Example 4 and Examples 7-8 that the particle size of the porous carrier should not be too large, as it is not conducive to its spraying and addition, and if the particle size is too large, its usage will also increase, because the deacidification agent inside the porous carrier composite alkali is not easy to react with the acidic gas; and if its particle size is too small, it is easy to enter the bag filter with the flue gas, thereby increasing the amount of fly ash; through the test data, when the average particle size of the porous carrier is between 800 mesh and 100 mesh, better technical effects can be obtained.

[0046] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A flue gas deacidification fly ash treatment process, characterized in that: The deacidification agent used in the deacidification step is a powdered deacidification agent, which is sodium bicarbonate or a mixture of sodium bicarbonate and sodium hydroxide. The specific content is as follows: S1. Pass the flue gas from the incinerator outlet into the desulfurization tower, and detect the concentration and flow rate of hydrogen chloride and sulfur dioxide in the flue gas before entering the desulfurization tower, and set the initial addition amount of the powdered deacidification agent accordingly to ensure that within the initial 30-minute period, the initial addition amount of the deacidification agent is: the molar amount of the deacidification agent is the sum of 1.1-1.5 times the molar amount of hydrogen chloride and 2.1-2.6 times the molar amount of sulfur dioxide; then detect the concentration of acidic gas in the flue gas at the outlet of the desulfurization tower, and adjust the amount of the deacidification agent according to the detection data to ensure that the flue gas emission requirements are met; S2. The deacidified flue gas is passed through a bag filter for dust removal and then subjected to denitrification treatment.

2. A flue gas deacidification fly ash treatment process according to claim 1, characterized in that: The deacidifying agent is injected into the desulfurization tower through multiple channels.

3. A flue gas deacidification fly ash treatment process according to claim 1, characterized in that: The deacidification agent is a porous carrier composite alkali, and the porous carrier composite alkali is prepared by loading the deacidification agent on a porous carrier.

4. A flue gas deacidification fly ash treatment process according to claim 3, characterized in that: The porous carrier is one or more of vermiculite, sepiolite and montmorillonite.

5. A flue gas deacidification fly ash treatment process according to claim 3, characterized in that: The deacidification agent is sodium hydroxide.

6. A flue gas deacidification fly ash treatment process according to claim 3, characterized in that: The method of the porous carrier composite alkali is as follows: An aqueous solution of a deacidifying agent is prepared, and then a porous carrier is immersed in the aqueous solution of the deacidifying agent, filtered, and then dried or blown dry at a temperature below 45° C. to obtain a porous carrier composite alkali.

7. A flue gas deacidification fly ash treatment process according to claim 6, characterized in that: The aqueous solution of the deacidification agent is a saturated solution of the deacidification solvent.

8. A flue gas deacidification fly ash treatment process according to claim 6, characterized in that: The water content of the porous carrier composite alkali is ≤6%.

9. A flue gas deacidification fly ash treatment process according to claim 3, characterized in that: The average particle size of the porous carrier is 800 meshes to 100 meshes.

Images