TW202010565A - Aerosol generation controlling method during absorption process of ammonia desulfurization capable of realizing highly efficient desulfurization and dust removal while controlling ammonia escape and aerosol generation - Google Patents

Abstract

This invention relates to a method and a device for controlling aerosol generation during the absorption process of ammonia desulfurization, which uses an absorption circulation liquid containing ammonium sulfite to remove sulfur dioxide in the smoke to control the aerosol generation during the absorption process of ammonia desulfurization. By controlling graded solution ingredient and the reaction conditions, highly efficient desulfurization and dust removal can be realized while ammonia escape and aerosol generation during the absorption process can be controlled. After preliminary cooling and purifying, the smoke can be contacted with the absorption circulation liquid and the fine particles washing circulation liquid sequentially to control the solution ingredient and reaction temperature at all grades.

Description

Method for controlling aerosol generation in absorption process by ammonia desulfurization

This application requires the priority of Chinese Patent Application No. 201710800599.0 filed on September 7, 2017 and the priority of US Application No. 15/923,031 filed on March 16, 2018 according to 35 USC § 119, the entire contents of which are incorporated herein This article.

The disclosure content belongs to the technical field of environment, and specifically relates to a method for controlling the generation of aerosol in the absorption process of ammonia desulfurization.

Countries in the world emit sulfur dioxide to varying degrees. The huge amount of sulfur dioxide emissions in China has a huge impact on the environment and society. In 2014, the total amount of sulfur dioxide emissions was 19.74 million tons, and the total amount of sulfur dioxide emissions in 2015 was 18.591 million tons, ranking first in the world, causing huge economic losses and seriously affecting China’s ecology. Environment and people's health.

There are hundreds of mature desulfurization technologies, of which the wet desulfurization process is the most widely used, accounting for about 85% of the world's total desulfurization installed capacity. Common wet flue gas desulfurization technologies include limestone-gypsum method, double alkali method, sodium carbonate method, ammonia method, magnesium oxide method, etc. Ammonia desulfurization is a wet desulfurization process that uses ammonia as an absorbent. This method can use SO _{2 to} produce ammonium sulfate fertilizers. It is a green flue gas treatment plan with low energy consumption, high added value, and resource recycling. A large amount of waste ammonia is produced in the chemical industry during the production process. Therefore, the ammonia industry desulfurization of boiler waste gas in the chemical industry has its unique advantages.

The ammonia desulfurization process mainly includes three processes: absorption, oxidation and concentration (crystallization):

Absorb sulfur dioxide with ammonium sulfite to obtain a mixed solution of ammonium sulfite and ammonium bisulfite. After neutralization with ammonia, ammonium sulfite is obtained: (NH ₄ ) ₂ SO ₃ +H ₂ O+SO ₂ =2NH ₄ HSO ₃ (NH ₄ ) _X H(2-x)SO ₃ +(2-x)NH ₃ =(NH ₄ ) ₂ SO _{3 The} solution is fed with oxidizing air to oxidize ammonium sulfite to obtain ammonium sulfate: (NH ₄ ) ₂ SO ₃ +1/2O ₂ = (NH ₄ ) ₂ SO ₄ ; and the ammonium sulfate solution is concentrated, crystallized, solid-liquid separated, and dried to obtain the final product, ammonium sulfate.

The three processes of absorption, oxidation and concentration seem to be simple. Actually they influence each other. Conventionally, in order to ensure the absorption efficiency, the content of ammonium sulfite and free ammonia in the absorption liquid is maintained at a high level and the content of ammonium sulfate is maintained at a low level. Although it is conducive to absorption, it is not conducive to oxidation and concentration. The pH of the absorption liquid is maintained at ~7, As a result, ammonia escapes during the absorption process and the aerosol is severe.

In order to ensure the absorption efficiency, the water temperature, reheater, dilute ammonium sulfate solution cooling and other measures that are conducive to absorption, but not conducive to oxidation and concentration, should be controlled as usual to control the absorption temperature below 40℃. At lower temperatures, high concentrations of ammonium sulfite cannot be directly and completely oxidized to ammonium sulfate, but can be oxidized at lower concentrations to obtain products through evaporation and concentration processes, which have large evaporation, large energy consumption and long process , More equipment, large area, high operating cost, and poor economic efficiency of the device. And the water content of general boiler flue gas is maintained above 7%. The water content of industrial waste gas such as sulfur recovery waste gas and incineration flue gas even exceeds 25%. Therefore, if the absorption efficiency is deliberately reduced and the absorption temperature is reduced to above 40°C, not only the energy consumption is high, but also the water in the flue gas will condense. Excessive condensate is not conducive to defogger flushing and tower wall flushing, and must be discharged in the form of waste water.

For dry sulfuric acid waste gas, due to low water content and low sulfur dioxide concentration, the absorption temperature can be controlled at 30-50°C.

The flue gas ammonia desulfurization process may include the following technical issues: 1. Ammonia escape and aerosol

Unlike the limestone-gypsum method based on limestone, ammonia is easily volatilized. When free ammonia is present in the absorption liquid, ammonia, SO ₂ and SO ₃ are simultaneously present in the gas phase. Therefore, it is easy to form ammonium sulfite and ammonium sulfide mist, and with this mist as the core, the saturated water vapor in the flue gas condenses on these mists to form a dense white mist, which causes ammonia loss on the one hand and secondary Pollution.

Up to now, the ammonia desulfurization has not been effectively promoted. The main reason is that the previous efforts focused on how to capture the aerosol generated during the absorption process, but did not inhibit or reduce the generation of aerosol during the absorption process, resulting in large system investment and operating costs. High and unstable operation. 2. Ammonium sulfite oxidation

Ammonium sulfite oxidation is different from other sulfites. At a certain concentration, NH ₄ ⁺ has a damping effect on the oxidation process. Literature [e.g. Kinetics Of Heterogeneous Oxidation Of Concentrated Ammonium Sulfite by Zhou, J., W. Li and W. Xiao, Chemical Engineering Science, Volume 55, December 23, 2000, pages 5637-5671, Pergamon Press, Oxford , England, 2000, the entire contents of which are incorporated herein] illustrates the unique property that NH ₄ ⁺ significantly hinders the dissolution of O ₂ in aqueous solutions. When the salt concentration is less than 0.5 mol/L (about 5% (wt)), the oxidation rate of ammonium sulfite increases as its concentration increases, and when this limit is exceeded, the oxidation rate decreases with increasing concentration. In addition, when the total ammonium salt concentration is 3-4mol/L, and the concentration of ammonium sulfite is less than 0.15mol/L, the oxidation reaction of the solution is a 0-level rapid reaction, that is, the oxidation rate is independent of the ammonium sulfite content.

The ammonium sulfite oxidation reaction actually occurs during the absorption process, except that due to the low O ₂ content in the flue gas, the temperature is low, and the reaction speed is slow, but under continuous circulation conditions, the oxidation rate is generally 40-70%. However, it is still necessary to further increase the oxidation rate to more than 95% to meet the post-processing requirements, so an oxidation tank/oxidation section/jet oxidizer is used to fully oxidize ammonium sulfite under the condition of excess and pressurized oxidation air. Some technicians choose to add a catalyst to the absorption liquid to promote oxidation, but this will affect product quality. 3. Recovery of ammonia entrained in exhaust gas

Unlike other alkaline substances, ammonia is volatile. The traditional countercurrent contact absorption tower, whether it is a spray tower, a packed tower or a plate tower, in order to ensure the desulfurization efficiency and the final emission index, at the contact point located at the top of the absorption zone, the pH of the solution is the highest and the SO _{2 in the} gas phase The concentration is the lowest, and the concentration of ammonia in the gas phase will be the highest. This means that the amount of ammonia that overflows the desulfurization tower with the exhaust gas will be large. This will cause both waste and loss of ammonia and new pollution.

In response to the problem of aerosol and ammonia escape, well-known research institutions and engineering technology companies have proposed a variety of solutions to control or eliminate, such as wet electricity, multi-stage water washing, multi-stage defogging, or a combination thereof, but these methods are not from the absorption process. Solve the source of the escape of sol and ammonia, and focus only on how to eliminate the ammonia escape and the aerosol generated during the absorption process, which makes the number of towers more and more, the system is more complicated, not only the treatment effect is bad, but also the investment operating cost A substantial increase.

The absorption, oxidation and concentration of the ammonia desulfurization device affect each other. The absorption requires a high solution pH and high ammonium sulfite content. The oxidation requires a relatively low total ammonium salt concentration, low ammonium sulfite content, and concentration requires high ammonium sulfate content. To control the escape of ammonia, aerosols require a low pH and the solution does not contain free ammonia.

Due to the different requirements for the composition of the solution in different processes, a more reasonable technology for controlling aerosol generation is needed to achieve coordinated control of absorption, oxidation, and concentration. While meeting the emission requirements, it reduces investment, simplifies the technical process, and reduces the difficulty of operation.

The Chinese invention patent with application number CN02136906.2 proposes a method and device for the extraction and recovery of SO ₂ in flue gas, controlling the concentration of ammonium sulfite between 0.1-5% (wt), for example between 0.5-2.0% In order to create conditions conducive to oxidation, reduce energy consumption and investment in oxidation, and ensure high desulfurization efficiency, the absorption liquid ammonia/sulfur ratio is 1.3-1.8 (molar ratio), and the absorption gas/liquid ratio is 2000-5000 (volume ratio). The hot flue gas heat is used to concentrate the ammonium sulfate solution. The temperature of the hot flue gas is reduced to 50-55℃, and the concentration of ammonium sulfate can be increased to 40-50% (wt). It is sent to the ammonium sulfate crystallizer and processed into commercial ammonium sulfate fertilizer. The oxidation section is provided with a longitudinal partition plate to separate the unoxidized ammonium sulfite solution from the oxidized ammonium sulfide solution as much as possible to prevent back mixing. In this method: 1) The concentration of the absorption liquid is low, which is only suitable for low-sulfur flue gas; 2) No attention is paid to the control of ammonia escape and aerosol generation during the absorption process, and a reheater needs to be set to eliminate white smoke; 3) Crystallization Affected by drying air volume and dust content, the crystal volume is small and unstable.

The Chinese invention patent with application number CN201310634675.7 proposes a desulfurization and denitration system and a desulfurization and denitration method, wherein the absorption section includes a first-level circulating liquid spray layer I and a first-level circulating liquid spray set in order from bottom to top Shower layer II, filler absorption layer and primary circulation liquid spray layer III, wherein the primary circulation liquid spray layer I is a fixed ammonia addition absorption layer for efficient absorption of SO ₂ , the fixed ammonia addition absorption layer is a separate Ammonia absorption circulation system, primary circulation liquid spray layer II and filler absorption layer are used to prevent ammonia from escaping and absorbing SO ₂ , and primary circulation liquid spray layer III is used to prevent ammonia from escaping. However, the composition of the solution is not clear, and the effect of controlling the escape of ammonia and the aerosol is limited only by adding ammonia in layers.

The Chinese invention patent with application number CN201510009642.2 proposes an integrated ultra-low emission method of ultrasonic desulfurization and dust removal, setting the absorption liquid droplet washing system to fully wash the flue gas after cooling and desulfurization to capture and remove the absorption liquid in the flue gas Droplets, and then defogging; after defogging, the flue gas is then washed and defogged by absorption liquid droplets; the above-mentioned preliminary purified flue gas continues to agglomerate or/and coagulate and increase the particle size of fine particles and then agglomerate Or/and layer demister to remove the increased fine particles; multi-stage water washing and multi-stage defogging are adopted to ensure the total dust is qualified, the investment is large, the operating cost is high, and the escape of ammonia and the generation of aerosol are not controlled from the mechanism.

The Chinese invention patent with application number CN201510680578.0 proposes an ammonia double-cycle desulfurization, denitration and dust removal system, which includes a scrubbing absorption tower (1) and an oxidation circulation tank (9); the scrubbing absorption tower (1) is sequentially dewatered The mist section (2), the enhanced ammonia removal mist section (3), the absorption liquid mist removal section (4), the secondary absorption section (5), the primary absorption section (6), and the washing and cooling section (7); When entering the first-stage absorption section (6), the ammonium sulfate solution containing ammonium nitrate with a density of 1.1 to 1.15 kg/L and a pH of 6.5 to 7 is used as the absorption liquid to mainly remove SO ₂ ; when the flue gas enters the second stage In the absorption section (5), an ammonium sulfate solution containing ammonium nitrate with a density of 1.05 to 1.1 kg/L and a pH of 5.5 to 6 is used as an absorption liquid to assist in the removal of SO ₂ . The manufacturing process is complicated, the ammonia used in the absorption process is excessive, the aerosol and ammonia escape significantly, and it is difficult to guarantee the final emission index by washing and defogging.

The Chinese invention patent with application number CN201610390173.8 proposes a single tower six-stage cascade purification desulfurization and dust removal ultra-low emission integrated device, including: oxidation section, concentration section, absorption section, purified water washing section, defogging section, separator and wet Electric section; the wet electric section further removes the tiny mist droplets carried in the flue gas after demisting by electrostatic adsorption to ensure that the flue gas meets the standard discharge when the flue gas working conditions change, and is used as an insurance measure for this device . This process requires a large investment, has high operating costs, and is a non-functional method of electrically controlling ammonia slip and aerosol emissions.

The Chinese invention patent with application number CN201610177178.2 proposes a combined process for desulfurization and dust removal with ultra-low emissions. The device includes a desulfurization tower (1); the desulfurization tower (1) is provided with a flue gas inlet (2) and flue gas Outlet (9); between the flue gas inlet (2) and the flue gas outlet (9), according to the flue gas flow direction, set the cooling and cooling section (3), the first absorption section (4), the second absorption section ( 5). The first-level defogging section (6), the second-level defogging section (7) and the third-level defogging section (8); after the flue gas of 120 ℃ ~ 180 ℃ containing SO ₂ in coal combustion is denitrified and dedusted, From the flue gas inlet (2) into the washing and cooling section (3), spray with an ammonium sulfate solution with a pH value of 3 to 5 and a density of 1200 to 1250 g/L to reduce the temperature of the flue gas to 45 ℃~60℃; the flue gas flows into the first absorption section (4), sprayed with the absorption liquid with the pH value of 5.5~6.5 and the density of 1100~1250g/L; the flue gas reaches the second absorption section (5) ，Spray with an absorption solution with a pH value of 5.0~5.8 and a density of 1030~1100g/L, and then the flue gas will enter the first-level defogging section (6), second-level defogging section (7) and third-level defogging section in sequence. (8), discharged from the flue gas outlet (9). Gradient elution of hot flue gas by controlling the density and pH value of the absorption liquid, combined with the use of special demisters and other devices to remove mist droplets, etc., can effectively remove sulfur and soot in the flue gas to achieve ultra-low emission. However, the solution composition and absorption temperature are not specified in this process, and ammonia escape and aerosol generation cannot be controlled from the source.

The Chinese invention patent with application number CN201611014433.8 proposes a method to reduce the production of aerosols by ammonia desulfurization. The specific steps are: 1) Ammonia water is pumped into the ammonia absorption tower, and the first-level absorption circulation pump is started for spray washing and desulfurization. Most of the SO2 in the flue gas; 2) The ammonia water is injected into the ammonia absorption tower for spray washing, and the spray liquid further reacts with the SO2 flue gas to remove pollutants in the flue gas; 3) After the second absorption The flue gas is washed with water spraying device to aerosol and other impurities entrained in the flue gas; 4) Finally, the liquid mist and residue carried by the flue gas in the process of washing and spraying are washed by the flue gas after water washing Impurities such as aerosols are purified, and the cleaned exhaust gas meets the emission standards. In step 1), the pH of the absorption liquid is strictly controlled at 5.5~6.5, and the density is 1.15~1.25g/ml. In step 2), the pH of the absorption liquid is strictly controlled at 5.0~6.0, and the density is 1.0~1.20g/ml. The solution composition and absorption temperature are not specified in this process, and the escape of ammonia and the generation of aerosol cannot be completely controlled from the source. The flue gas after the same simple water washing and defogging cannot meet or meet the requirements of China's ultra-low emission standards or higher requirements.

The Chinese invention patent with application number CN201611207184.4 proposes a process for saving water and controlling aerosol in the ammonia desulfurization process. The boiler flue gas enters the desulfurization tower, and the spray liquid and the SO ₂ containing smoke in the desulfurization tower Spraying with gas, the spray liquid adopts ammonium sulfate/ammonium sulfite solution with a concentration of 5-35%, and then contacts the cooling water on the filler layer through the filler layer and then contacts the water spray layer, and the bottom of the filler layer is cooled The water falls into the washing liquid tray and flows back to the cooling water tower, and then enters the washing container to be recycled by the washing water delivery pump to the washing spray layer for recycling; the system has the advantages of simple process, good cooling effect, low operating cost, etc. The cooling water absorbs (NH4) ₂ SO ₄ particles, SO ₂ , and NH ₃ in the boiler flue gas. The saturated water vapor in the boiler flue gas condenses with (NH ₄ ) ₂ SO ₄ particles as cores to form water droplets and trap the boiler. The (NH ₄ ) ₂ SO ₄ particles in the flue gas inhibit the formation of aerosols, so that the concentration of particulate matter in the flue gas discharged from the ammonia desulfurization process is less than 30 mg/m ³ . In this process, the solution composition, pH value and absorption temperature are not clear, and the escape of ammonia and aerosol generation cannot be completely controlled from the source, and the energy consumption of low-temperature water washing is high. The concentration of particulate matter in the net flue gas is less than 30mg/m ³ , which cannot be satisfied The latest emission standards.

The Chinese invention patent with the application number CN201310340885.5 proposes a method for controlling the emission of ammonia desulfurization aerosol and its special absorption tower, and the flue gas cooled to 100~120°C by atomizing water spray is passed into the desulfurization absorption tower In the desulfurization zone, the flue gas from the bottom up in the desulfurization zone contacts the desulfurization liquid sprayed from the top down to absorb SO ₂ in the flue gas, and the filler or sieve plate is set in the desulfurization zone; After desulfurization, it enters the packing washing area, and the washing water is injected to remove the coarse and fine aerosol generated in the ammonia desulfurization; the flue gas enters the water vapor phase transition area after desulfurization and removal of the coarse and fine aerosol, from the water vapor phase transition area Inject steam in the middle to establish the supersaturated water vapor environment required for the water vapor phase transition, so that the unremoved fine aerosol particles will condense and grow and be removed by the wire mesh demister at the outlet of the flue gas in the water vapor phase transition area; The flue gas outlet at the top of the desulfurization absorption tower is discharged through the chimney. The gas velocity of the flue gas empty tower is 2.0~3.0m/s, the operating liquid-gas ratio is 2~8L/Nm ³ ; the pH value of the desulfurization liquid is 5.2~6.0, and the temperature of the desulfurization liquid is 45~55℃; The desulfurizing agent in the desulfurization liquid is ammonium sulfate or ammonium sulfite, the concentration is 10%wt to supersaturation, the gas ratio of the washing water spray liquid in the packing washing area is 0.6~3.0L/Nm ³ , washed by the packing layer After the flue gas temperature drops to 50~55℃, in the example, the PM ₁₀ mass concentration at the outlet of the absorption tower has a minimum concentration of 45 mg/m ³ and a minimum SO ₂ concentration of 135 mg/Nm ³ . The process still cannot completely control the escape of ammonia and the generation of aerosol from the source. The particulate matter and SO ₂ in the net flue gas cannot meet the latest emission standards, and the energy consumption of the vapor phase change is high.

The Chinese invention patent with application number CN201610966033.0 proposes a device and method for removing aerosols from ammonia desulfurization. The device includes a desulfurization tower (1), and the desulfurization tower (1) is provided with absorption reaction zones in order from bottom to top. (2), oxidized water washing area (3) and water washing purification area (4); the oxidized water washing area (3) is provided with an oxidized water washing spray layer (22) to control the concentration of dissolved ammonium sulfate in the oxidized water washing circulating liquid ≤3 %; the temperature of water washing and purification is ≤50℃; the strong oxidant includes hydrogen peroxide or hypochlorite. In this process, the solution composition, pH value and absorption temperature are not specified, and the escape of ammonia and the generation of aerosol cannot be completely controlled from the source, and the investment in oxidative water washing is large, the operating cost is high, and there are certain safety risks.

definition

"Ammonia escape" means ammonia or one or more ammonia/amine-containing substances that escape as the gas stream is discharged. This material comes from ammonia or ammonia/amine-containing materials added to the gas stream.

"Dust" means a sufficiently fine particulate material that floats with the gas flow during handling, processing, or contact. It includes but is not limited to aerosols, including solid aerosol-4-particles and liquid aerosol particles, soot, charcoal, non-combustible coal, fine minerals, sand, gravel, salt, and any combination thereof.

"Exhaust" means air flow that exists in industrial or chemical processes. It includes but is not limited to flue gas, exhaust gas, exhaust gas of ovens, furnaces, boilers and/or generators. It can contain combustion products from combustion air and combustible materials, and residual materials from chemical processes can include water, nitrogen, and pollutants such as particulate matter, soot, carbon monoxide, nitrogen oxides, and sulfur oxides. Exhaust gas from one process can be used as gas input from another process.

"Oxidation rate" means the mole percentage of a given material that has been converted to a defined oxide of that material. For example, in a mixture that includes ammonia-containing substances and sulfur oxides, if the X mol% of the mixture is ammonium sulfate, Y mol% is ammonium sulfite, and Z mol% is some other ammonia and sulfur containing greater oxidation potential than ammonium sulfate And/or oxygen species, since it is clear that ammonium sulfate is the most oxidized species, the oxidation rate of the mixture is X mol%.

"Ammonia recovery rate" means the proportion or percentage of ammonia that is captured and added to the gas cleaning process from the process.

"Spray coverage" is the divergence of the spray liquid from the spout or spout array. The greater the divergence, the greater the spray coverage.

If the above definitions or the descriptions elsewhere in this application are not in common use with the meanings (express or implied) listed in the dictionary or incorporated by reference in the source of this application, this application and the patent application The scope is specifically understood to be interpreted according to the definition or description in this application, rather than according to common definitions, dictionary definitions or definitions incorporated by reference. If the term of patent scope can be understood only when it is interpreted by a dictionary, it should be controlled as defined in Kirk-Othmer Encyclopedia of Chemical Technology, 5th Edition, 2005, (John Wiley & Sons, Inc.). provide.

All ranges and parameters disclosed herein should be understood to include any and all subranges contained therein, as well as every number between the endpoints. For example, the range of "1-10" should be understood to include any and all subranges between (and inclusive of) the minimum value 1 and the maximum value 10, that is, with a minimum value of 1 or greater (eg, 1-6.1) Start, end with a maximum value of 10 or less (eg 2.3-9.4, 3-8, 4-7), and end up with 1, 2, 3, 4, 5, 6, 7, 8, 9 in this range And any subrange of 10 for each number. Unless otherwise specified, all percentages, ratios, and ratios herein are by weight, and unless specifically stated otherwise, the term "molecular weight" means weight average molecular weight (Mw).

Provide a method and device for controlling aerosol generation in ammonia desulfurization. The apparatus may include, and the method may involve a gas purification and removal system. A gas purification and removal system can be configured to apply an ammonium salt gradient to the flue gas. The apparatus may include, and the method may involve an oxidation system. The apparatus may include, and the method may involve an auxiliary system.

The oxidation system may include an oxidation vessel configured to perform forced oxidation of the input ammonium solution to produce multiple ammonium solution outputs of different degrees of oxidation. The oxidation vessel may provide an output to the gas purification and removal system to define the gradient.

The auxiliary system may include an ammonium sulfate aftertreatment system. The auxiliary system may include an ammonia supply system. The auxiliary system may include a process water system.

The device may include a tower. The tower can contain a gas purification and removal system. The tower may include a pre-wash zone. The tower may include an absorption zone. The tower may include a fine particle control zone.

The device may include elements disposed between the absorption zone and the pre-wash zone. The element may only allow gas to pass through. The device may include multiple spray layers. The pre-wash zone may include one spray layer of the plurality of spray layers. The absorption zone may include one spray layer of the plurality of spray layers. The fine particle control area may include one spray layer of the plurality of spray layers. The tower can be configured to provide zone control of the solution composition to the spray layer. Zoning control may include providing different components to different spray layers. Different components can be selected or adjusted to select or adjust the gradient.

The oxidation system may include a spray layer. The oxidation system can be configured to control the interaction between (a) the liquid sprayed in different spray layers and (b) the flue gas in different spray layers to naturally oxidize the liquid to produce multiple ammonium solutions with different degrees of oxidation Output to define the gradient.

The oxidation system can be configured to control the operating temperature of one or more of the prewash zone, absorption zone, and fine particulate control zone to control the gradient.

The oxidation system may be an oxidation system that does not include a forced oxidation vessel.

The oxidation system can be configured to allow the pre-wash solution to enter the absorption zone.

Each zone may include a single spray layer. Each zone may include multiple spray layers.

The device may include elements disposed between the absorption zone and the fine particle control zone. The element may only allow gas to pass through.

The device may include components disposed within the absorption zone. The element may only allow gas to pass through.

The device may include components disposed within the fine particle control zone. The element may only allow gas to pass through.

The device may include multiple demister layers. The demister layers of multiple demister layers may be disposed within the fine particle control area. A demister layer of multiple demister layers may be disposed in each spray layer of the pre-wash zone and the absorption zone.

The demisters of multiple demister layers may include baffles.

The demisters of multiple demister layers may include roof ridges.

The demisters of multiple demister layers may include fillers.

The demisters of multiple demister layers may include wire mesh.

The demisters of multiple demister layers may include a combination of one or more of baffles, ridges, fillers, and wire mesh.

Each spray layer of the absorption zone may have a liquid-gas ratio of not less than 0.2 L/Nm ³ . Each spray layer of the absorption zone may have a spray coverage of not less than 110%.

Each spray layer of the fine particle control area may have a liquid-gas ratio of not less than 0.1 L/Nm ³ . Each spray layer of the fine particle control area may have a spray coverage of not less than 105%.

Each spray layer in the absorption zone may have a liquid-to-gas ratio of not less than 0.2 L/Nm ³ and a spray coverage of not less than 110%; each spray layer in the fine particle control zone may have a liquid-gas ratio of not less than 0.1 L/ Nm ³ , spray coverage is not less than 105%.

The oxidation system may include multiple stages. Each segment can correspond to a different composition of ammonium salt. The oxidizing system can be configured to provide one of a plurality of components to the fine particle washing circulating fluid and the absorption circulating fluid to form an ammonium salt gradient.

A section can be defined by a layer of the oxidation system.

A section can be defined by elements of the oxidation system.

One section can occupy different positions in the oxidation system.

The oxidation system may include 0, 1, 2, 3, 4, 5 or more layers of gas-liquid dispersion intensifiers.

The oxidation system may include a liquid grade. The liquid level is greater than 3m. The oxidizing air system can be configured to provide over 20% excess oxidizing air.

The tower can be configured to cool and wash the flue gas in the pre-washing zone with circulating washing liquid, while increasing the concentration of circulating washing liquid. The tower can be configured to pass the flue gas through the absorption zone, wherein the flue gas is washed and desulfurized with the absorption circulating liquid. The tower can be configured to allow flue gas to pass through the fine particle control zone, in which fine particles are removed with a circulating washing liquid of fine particles. The tower can be configured to discharge flue gas. The tower can be configured to supplement the circulating washing liquid in the pre-washing zone from the circulating washing liquid of fine particles. The tower can be configured to flush the scale on the tower wall. The tower can be configured to supplement absorption circulating fluid. The tower can be configured to oxidize the absorption circulating fluid in the oxidation system. The tower can be configured to draw circulating liquids with different compositions from different sections of the oxidation system to different areas.

The fine particle circulating washing liquid may be the main component of the circulating washing liquid replenishing liquid.

The tower can be configured to wash the scale deposits by spraying fine particles to circulate the washing liquid. The fouling may be chemical fouling. The fouling may be physical fouling. This fouling can be inside the tower. The fouling can be on the structure inside the tower.

The tower can be configured to rinse scale deposits by spraying process water.

The tower can be configured to supplement the absorption circulating fluid with the liquid in the fine particle control zone.

The tower can be equipped with process water to supplement the absorption circulating fluid. The tower can be configured to supplement the process water with liquid from the fine particulate control zone.

The tower can be configured to provide the flue gas velocity of the empty tower in the range of 1-5 m/s.

The tower can be configured to provide temperatures in the pre-wash zone in the 40°C-80°C range.

The tower can be configured to receive flue gas with SO ₂ concentration up to 30000 mg/Nm ³ .

The configurable tower can discharge the purified flue gas that meets the following requirements: In 2011, the Ministry of Environmental Protection of the People's Republic of China, all emission requirements of thermal power plant air pollutant emission standard GB13223-2011, the entire contents of which are incorporated herein. For example, GB13223-2011 requires that the emissions of dust, sulfur dioxide and nitrogen oxides from coal-fired boilers in key areas of China are not higher than 20, 50 and 100 mg/Nm ³ (oxygen content 6%, dry basis). According to Huanfa No. 164 (The Ministry of Environmental Protection, Development and Reform Commission of the People's Republic of China, and the National Energy Administration issued a comprehensive implementation plan for ultra-low-emission and energy-saving transformation of coal-fired power plants on December 11, 2015, the entire contents are here (Incorporated into this article), China will strive to achieve ultra-low emissions by 2020 (that is, at an oxygen content of 6%, the emission concentrations of soot, sulfur dioxide, and nitrogen oxides are not higher than 10, 35, and 50 mg/m ^{3, respectively.} ). At the same time, relative to the amino desulfurization and electrostatic defogging listed in PCT/US2002/039095, it includes the following methods to remove SO ₂ /NO/NO ₂ from flue gas: A. Oxidize some or all of the NO gas flow to NO ₂ ; , B. Wash some or all of SO ₂ , NO and NO _{2 in the} gas stream with ammonia-containing washing liquid with a pH between 6-8, C. Use an aerosol removal device to remove some or all of the ammonia aerosol generated in the washing step; D. To recover ammonium sulfate from the washing liquid as a fertilizer, the tower can have a 10-20% reduction in investment, a 5-10% reduction in operating costs, and a 15-30% increase in cost performance.

The tower can be configured to emit flue gas with a SO ₂ concentration not greater than 200 mg/Nm ³ . The tower can be configured to emit flue gas with a SO ₂ concentration not greater than 100 mg/Nm ³ . The tower can be configured to emit flue gas with a SO ₂ concentration not greater than 35 mg/Nm ³ . The tower can be configured to emit flue gas with a SO ₂ concentration not greater than 5 mg/Nm ³ .

The tower can be configured to emit flue gas with a total aerosol dust concentration not greater than 20 mg/Nm ³ . The tower can be configured to emit flue gas with a total aerosol dust concentration not greater than 10 mg/Nm ³ . The tower can be configured to emit flue gas with a total aerosol dust concentration not greater than 5 mg/Nm ³ . The tower can be configured to emit flue gas with a total aerosol dust concentration not greater than 2 mg/Nm ³ .

The tower can be configured to emit flue gas with an ammonia concentration not greater than 5 mg/Nm ³ . The tower can be configured to emit flue gas with an ammonia concentration not greater than 2 mg/Nm ³ .

The tower can be configured to emit flue gas with an ammonia concentration not greater than 1 mg/Nm ³ .

The tower can be configured to emit flue gas with an ammonia concentration not greater than 0.5 mg/Nm ³ .

The device may include drying equipment. The drying device can be configured to receive the absorption liquid. The drying equipment can be configured to produce a solid product that includes ions from the circulating liquid. The ion may include chloride ion. The ion may include fluoride ion.

Drying equipment can be configured to reduce the chloride ion concentration of the circulating fluid to less than 50000 mg/L. The drying equipment can be configured to reduce the fluoride ion concentration in the circulating liquid to less than 20,000 mg/L. The drying equipment can be configured to reduce the fluoride ion concentration in the circulating liquid to 300-3000 mg/L. The drying equipment can be configured to reduce the chloride ion concentration of the circulating liquid to 10000-31000 mg/L.

The spray layer of the tower in the absorption zone can be configured to absorb the quality ratio of ammonium sulfate to ammonium sulfite in the circulating liquid of 1.5-199:1.

The tower can be configured in the spray layer of the fine particle absorption area, and the quality ratio of ammonium sulfate to ammonium sulfite in the fine particle circulating washing liquid is 3-1999:1.

The method may include applying a gradient of ammonium salt to the flue gas. The method may include applying a gradient of reaction conditions to the flue gas.

Applying the ammonium salt gradient may include applying the first ammonium salt concentration in the first stage. Applying the ammonium salt gradient may include applying a second ammonium salt concentration in the second stage. Relative to the flue gas, the first stage may be upstream of the second stage.

The salt may include ammonium sulfite. The salt may include ammonium bisulfite. The salt may include ammonium sulfate.

The first concentration may be greater than the second concentration.

Applying the first ammonium salt concentration in the first stage may include spraying the absorption circulating liquid on the flue gas during the sulfur dioxide absorption process.

Applying the second ammonium salt concentration in the second stage may include spraying the absorption circulating liquid on the flue gas during the sulfur dioxide absorption process.

Applying the first ammonium salt concentration in the first stage may include spraying the fine particulate washing circulating liquid on the flue gas in the fine particulate washing process.

Applying the second ammonium salt concentration in the second stage may include spraying the fine particle washing circulating liquid on the flue gas in the fine particle washing process.

Applying a gradient of reaction conditions may include providing a first temperature at the first stage. Applying a gradient of reaction conditions may include providing a second temperature at the second stage. Relative to the flue gas, the first stage may be upstream of the second stage.

The first temperature may be higher than the second temperature.

Providing the first temperature at the first stage may include setting the first temperature during the sulfur dioxide absorption process. Providing the second temperature at the second stage may include setting the second temperature during the fine particle washing process.

Applying a gradient of reaction conditions may include providing a first pH in the first stage. Applying a gradient of reaction conditions may include providing a second pH at the second stage. Relative to the flue gas, the first stage may be upstream of the second stage.

The first pH may be greater than the second pH.

Providing the first pH at the first stage may include spraying the absorption circulating liquid on the flue gas during the sulfur dioxide absorption process.

Providing the second pH at the second stage may include spraying the absorption circulating liquid on the flue gas during the sulfur dioxide absorption process.

Providing the first pH at the first stage may include spraying the fine particulate washing circulating liquid on the flue gas during the fine particulate washing process.

Providing the second pH at the second stage may include spraying the fine particulate washing circulating liquid on the flue gas during the fine particulate washing process.

The method may include cooling and purifying the flue gas. The method may include absorption of sulfur dioxide after cooling and purification. The method may include washing the circulating liquid with fine particles to remove smoke after absorption. The ammonium salt gradient can be applied after purification and cooling. Both the absorption and the removal may include spraying ammonium sulfite. Both the absorption and the removal may include spraying ammonium sulfate.

The absorption may include spraying absorption circulation liquid on the flue gas. The fine particulate washing circulating fluid may have a pH lower than that of the flue gas absorption circulating fluid. The fine particulate matter washing circulating fluid may have an ammonium sulfite concentration that is less than that of the absorption circulating fluid.

The reaction condition may be a temperature gradient. The temperature gradient can be defined by the absorption temperature and the washing temperature. Applying a gradient of reaction conditions may include controlling absorption temperature and washing temperature to reduce energy loss. Applying a gradient of reaction conditions may include maintaining absorption efficiency. Applying a gradient of reaction conditions may include maintaining a limit to ammonia slip. Applying a gradient of reaction conditions may include maintaining restrictions on aerosol escape.

The absorption temperature can be in the range of 30°C-70°C.

The absorption temperature can be in the range of 35°C-60°C.

The absorption temperature can be in the range of 45°C-55°C.

The washing temperature may be in the range of 28°C-68°C.

The washing temperature may be in the range of 30°C-55°C.

The washing temperature may be in the range of 40°C-50°C.

The absorption may include spraying absorption circulation liquid at the lower stage. The absorption may include spraying the absorption circulating liquid with the upper stage downstream of the lower stage relative to the flue gas. The absorption circulating fluid may include 0.15%-4.95% ammonium sulfite in the first stage or two stages of the lower stage and the upper stage. The absorption circulating fluid may include 5%-38% of ammonium sulfate in the first stage or two stages of the lower stage and the upper stage. The absorption circulating liquid may have a pH value in the range of 4-6.6 in the first or two stages of the lower and upper stages. The concentration of ammonium sulfite in the upper absorption circulation liquid may be lower than that in the lower absorption circulation liquid.

The pH of the upper absorption circulation liquid may be lower than the pH of the lower absorption circulation liquid.

The absorption may include spraying absorption circulation liquid at the lower stage. The absorption may include spraying the absorption circulating liquid with the upper stage downstream of the lower stage relative to the flue gas. The absorption circulating fluid may include 0.15%-4.95% ammonium sulfite in the first stage or two stages of the lower stage and the upper stage. The absorption circulating fluid may include 5%-38% of ammonium sulfate in the first stage or two stages of the lower stage and the upper stage. The absorption circulating liquid may have a pH value in the range of 4-6.6 in the first or two stages of the lower and upper stages. The pH of the upper absorption circulation liquid may be lower than the pH of the lower absorption circulation liquid.

The absorption may include spraying the absorption circulating fluid in a single stage.

The absorption may include spraying the absorption circulating fluid only in two stages.

In the removal stage, the fine particulate washing cycle fluid may include 0.003%-1% ammonium sulfite. In the removal stage, the fine particulate washing cycle liquid may include 0.3%-38% ammonium sulfate. In the removal stage, the fine particulate washing cycle liquid may have a pH in the range of 3-5.4.

The removal may include spraying the fine particle washing cycle liquid in two stages. At the level of this level, the fine particulate washing circulating fluid may include 0.1% to 1% ammonium sulfite. At the level of this level, the fine particulate washing circulating fluid may include 5%-38% ammonium sulfate.

The device and method control the escape of ammonia and aerosol generation from the source. The absorption liquid containing ammonium sulfite removes sulfur dioxide in the flue gas. The ammonia is converted into ammonium sulfite by adding an absorption circulating liquid before performing ammonia desulfurization. In addition, by using fractional solution composition control and reaction condition control, collaborative control of absorption, oxidation, and concentration can be achieved. This simplifies the process flow, reduces investment, and forms the disclosed technology.

The illustrative principles of the invention, such as those described below, can be used alone or in combination, or in combination with other illustrative principles herein: 1. The gas purification process can include an absorption cycle and a fine particle washing cycle, and the circulating fluid during the gas purification process can include absorption Circulating fluid and fine particles wash the circulating fluid. The absorption circulating fluid can be mainly used for desulfurization and to control the aerosol generation in the desulfurization process. The fine particulate matter washing circulating liquid can further promote the desulfurization efficiency while controlling fine particulate matter. 2. The reaction conditions can be controlled, the pH value of the absorption circulating liquid can be reduced to below 6.6, the absorption temperature can be controlled at 30 ℃ -70 ℃, in order to reduce the ammonia escape and aerosol in the absorption process, the total dust at the outlet after the demisting in the absorption area is not More than 100mg/Nm ³ . This can reduce energy consumption, reduce or avoid wastewater discharge, and provide long-term stable operation of the device. 3. The content of ammonium sulfite in the absorption circulating fluid can be controlled. This can control the generation of aerosol during absorption, produce favorable oxidation conditions, and reduce energy consumption and costs associated with oxidation. 4. The heat of flue gas can be used for concentration of ammonium sulfate solution. It can increase the ammonium sulfate content of the absorption circulating fluid, which is generally above 5%, for example, not less than 15-35%. This can maintain the absorption efficiency and control the generation of aerosol while promoting the concentration process. Processes that are configured to accept untreated flue gas with SO ₂ concentrations greater than 10,000 mg/Nm ³ require only saturated crystallization. For flue gas with higher SO ₂ concentration, part of the solution can be sent to the evaporative crystallization unit to reduce the investment and energy consumption of the ammonium sulfate post-treatment system. 5. An oxidation system that can include different layers, different equipment, or both can be controlled and implemented according to the desired solution composition. The fine particulate washing circulating fluid and the absorption circulating fluid can be taken out from different positions (each corresponding to a different layer) or different equipment in the oxidation vessel of the oxidation system.

Controlling the generation of aerosol during the absorption process can facilitate the process of exposure. The control means may include zoned precise control of the solution components. Absorption circulating fluid can be set to 1 or more levels. Level 1 or multiple levels can include ammonium sulfite and ammonium sulfate, and fine particle washing cycle fluid can be set to level 1 or multiple levels. Level 1 or multiple levels may contain ammonium sulfite and ammonium sulfate. The pH value of the fine particulate washing circulating fluid may be lower than that of the absorption circulating fluid, and the content of ammonium sulfite is less than that of the absorption circulating fluid. The absorption temperature can be controlled within a suitable range to ensure the absorption efficiency, control ammonia escape, and aerosol while reducing energy consumption. The total dust at the outlet after demisting in the absorption zone can be no more than 100 mg/Nm ³ .

The composition of the zoned solution can be controlled by forced oxidation and/or natural oxidation and/or pre-washing liquid in the oxidation vessel into the absorption zone and/or by controlling the operating temperature.

The absorption temperature can be lowered by conventional means such as process water cooling and blending cold air, and increased by blending hot air and other conventional means.

A method for controlling the generation of aerosol in the absorption process by ammonia desulfurization may include removing sulfur dioxide in flue gas with an absorption circulating liquid containing ammonium sulfite to control the generation of aerosol in the absorption process by ammonia desulfurization.

The aerosol may include solid grains evaporated from droplets of circulating absorption liquid in high-temperature flue gas, and solid particles formed by reacting gaseous NH ₃ volatilized from ammonia in the circulating absorption liquid with SO _{2 in} flue gas, mainly The composition is (NH ₄ ) ₂ SO ₃ , NH ₄ HSO ₃ , NH ₄ HSO ₄ , (NH ₄ ) ₂ SO ₄ . The higher the pH value of the circulating absorption liquid and/or the higher the operating temperature, the more severe the aerosol.

The aerosol has a specific relationship with the total dust content of the export. The aerosol content is high and the total dust content of the export is high. Can not or do not have a good device to control aerosol, can not meet the ultra-low emission requirements, such as GB13223-2011, and the net smoke can form a "white dragon" when it is discharged into the atmosphere, which can stretch for several kilometers or even tens of kilometers , Causing severe smog pollution.

By controlling the composition of the graded solution and the control of the reaction conditions, efficient desulfurization and dust removal can be achieved, and at the same time, the escape of ammonia and the generation of aerosol can be controlled.

The fractional solution composition control may include concentration gradient control of ammonium sulfite, ammonium bisulfite, ammonium sulfate, or a combination thereof.

The flue gas after the initial cooling and purification can be contacted with the absorption circulating liquid and the fine particle washing cycle liquid in order to realize the coordinated control of absorption, oxidation and concentration. The absorption circulating fluid can be set to one or more stages as required, and one or more stages can include ammonium sulfite and ammonium sulfate. The fine particle washing circulating fluid can be set to 1 or more levels. One or more stages contain ammonium sulfite and ammonium sulfate.

The pH value of the fine particulate washing circulating fluid may be lower than that of the absorption circulating fluid, and the content of ammonium sulfite is less than that of the absorption circulating fluid.

Absorption temperature and washing temperature can be controlled within an appropriate range, while maintaining absorption efficiency, controlling ammonia escape and aerosol while reducing energy consumption.

The absorption circulating fluid may have any suitable number of stages, such as 1-2 stages, or 1 stage. When multi-stage is selected, the composition of one-stage or multi-stage absorption circulating fluid may include ammonium sulfite 0.15-4.95%, ammonium sulfate 5-38%, pH value 4-6.6, and the content of ammonium sulfite in the upper-level absorption circulating fluid may be lower than that of the lower-level Absorb circulating ammonium sulfite content. The pH value of the upper absorption circulation liquid may be lower than the pH value of the lower absorption circulation liquid.

The components of the one-stage or multi-stage fine particulate washing circulating fluid may include ammonium sulfite 0.003-1%, ammonium sulfate 0.3-38%, and pH value 3-5.4.

The fine particulate washing circulating liquid may have any suitable number of stages, for example, 2 stages. Level 1 in this level can be a circulating fluid with a high concentration of ammonium sulfate, of which ammonium sulfite is 0.1-1% and ammonium sulfate is 5-38%, and other grades can be dilute solutions, with ammonium sulfite content below 0.1%. May include grade 1 dilute solution. May include level 1 process water.

The absorption temperature may be any suitable temperature, such as 30-70°C, 35-60°C, or 45-55°C.

The washing temperature may be any suitable temperature, such as 28-68°C, 30-55°C, or 40-50°C.

The auxiliary system may include an ammonium sulfide aftertreatment system, an ammonia supply system, and a process water system.

The device and method can adopt zone control, and can include pre-washing zone, absorption zone, and fine particulate matter control zone, where the pre-wash zone, absorption zone, and fine particulate matter control zone are each set with one or more spray layers. There are gas-liquid separators between the washing area that only allow gas to pass and liquid to be taken out from the side or the lower part, such as liquid collectors, separators with gas caps, gas distribution plates, and liquid receiving trays.

Between the absorption zone and the fine particle control zone, the absorption zone, and the fine particle control zone, a gas-liquid separator that allows only gas passage and liquid to be taken out from the side or the lower part can be set as follows: When the original flue gas volume is greater than 800,000 Nm ³ At /h, a gas-liquid separator can be provided in the absorption area and the fine particle control area to allow only gas passage and liquid to be taken from the side or the lower part; when the original flue gas SO ₂ concentration is higher than 6000mg/Nm ³ , absorption A gas-liquid separator that allows only gas passage and liquid to be taken from the side or the lower part can be installed in the area; and when the total dust of the original flue gas is greater than 100mg/Nm ³ , the fine particle control area can be provided with only gas passage 、Gas-liquid separator with liquid taken from the side or lower part.

The fine particle control area may be provided with one or more layers of demisters, and each layer of the pre-wash area and the absorption area may be provided with one or more layers of demisters. The demister can adopt baffle, ridge, filler and wire mesh type, or a combination thereof.

The liquid-gas ratio and spray coverage of each layer in the absorption zone can be controlled so that sulfur dioxide, particulate matter, and free ammonia can be fully absorbed or nearly fully absorbed. Specifically, for example, the liquid-gas ratio of each layer in the absorption zone may be not less than 0.2L/Nm ³ , and the spray coverage may not be less than 110%; the liquid-gas ratio of each layer in the fine particle control area may be not less than 0.1L/Nm ³ , spray coverage The rate can be no less than 105%.

According to the requirements of solution composition control, the oxidation system can be established in layers or equipment. The fine particulate matter washing circulation liquid and absorption circulation liquid can be taken out from different positions or equipments of the oxidation container of the oxidation system.

In some embodiments, the absorption circulating fluid, high ammonium sulfate and ammonium sulfite concentration fine particulate washing circulating fluid may be taken from different locations of the oxidation system oxidation vessel. The absorption circulating fluid may include grades 1-3. The high ammonium sulfate and ammonium sulfite concentration fine particle washing cycle liquid may include grades 1-2. The low-concentration fine-particle washing circulation liquid can be circulated separately from the fine-particle washing circulation tank, and can be set to 1-3 levels.

In some embodiments, the absorption circulating fluid can be taken out of the absorption circulation tank, and may include grades 1-4. The high-ammonium sulfate and ammonium sulfite fine particle washing cycle liquid can be taken out from the oxidation system oxidation vessel, and can have a level of 1-2. The low-ammonium sulfate concentration fine particle washing circulation liquid can be circulated separately from the fine particle washing circulation tank. For example, if the imported flue gas sulfur dioxide concentration is lower than 2000 mg/Nm ³ (6%O ₂ , dry basis) and the pure gas sulfur dioxide emission concentration is higher than 100 mg/Nm ³ (6%O ₂ , dry basis), separate circulation may be omitted , Fine particles washing cycle liquid can spray 1-3 grade.

In some embodiments, process water can be used as the final stage (most downstream) fine particulate washing cycle liquid.

One to five layers of gas-liquid dispersion intensifier can be set in the oxidation vessel of the oxidation system. The gas-liquid dispersion intensifier can use one or more of structured packing, random packing, perforated plate, gas cap, aeration head, etc., or a combination thereof.

The oxidation vessel can have a liquid level greater than 3m and an excess of 20% of the oxidation air.

The method may include the following illustrative process: The flue gas enters from the pre-washing zone, is cooled and washed by the circulating washing liquid in the pre-washing zone, and the circulating washing liquid is concentrated at the same time. The flue gas is then desulfurized by the absorption circulating liquid in the absorption zone, and the fine particulate control zone is removed by the fine particulate circulating washing liquid Discharge after fine particles; The circulating washing liquid in the pre-washing zone is mainly supplemented by the circulating washing liquid of fine particles. The circulating washing liquid of fine particles and/or process water is used to rinse the scale deposits on the wall of the tower, and the circulating liquid is absorbed to circulate the washing liquid and/or the process by the controlling area of fine particles. Water replenishment; and The absorption circulating fluid is oxidized in the oxidation system, and solutions of different compositions are drawn from different locations or equipment of the oxidation vessel of the oxidation system to be circulated separately.

The process water can be replenished from one or both of the fine particle control area and the fine particle washing circulation tank, or the process water can be supplemented by rinse water; The composition of the solution can be controlled by forcibly oxidizing and/or natural oxidizing and/or pre-washing liquid into the absorption zone and/or operating temperature by the oxidation equipment. Under normal circumstances, the flue gas temperature is 110-180℃, the flue gas oxygen content is 3-7%, and the water content is 7-10%. At this time, it is necessary to control the forced oxidation of part of the circulating liquid to control the solution composition in the required range, but in the flue gas When the temperature exceeds 200°C and/or the flue gas oxygen content exceeds 8%, the natural oxidation of the absorption circulating fluid by the flue gas can meet the requirements. At this time, it is not necessary to control the forced oxidation during the circulation absorption process.

If the gas velocity of the absorption tower is high, the gas entrainment is severe, or the tightness of the trays between the zones is poor, the pre-washing circulation liquid and the absorption circulation liquid cross-flow with each other, and the ideal solution composition may also be obtained.

Implementation methods may include graded solution composition control and reaction condition control, to achieve high-efficiency desulfurization and dust removal, and to control ammonia escape and aerosol generation in the absorption process while efficiently desulfurizing. The desulfurization substance may include ammonium sulfite. The absorption circulating liquid may be a weakly acidic ammonium sulfate-ammonium sulfite mixed liquid, and the fine particle washing cycle liquid may be a more acidic and lower concentration ammonium sulfate-ammonium sulfite mixed liquid. This can help achieve coordinated control of absorption, oxidation, and concentration.

The absorption circulating liquid containing ammonium sulfite is used to remove sulfur dioxide in the flue gas. The absorption circulating liquid after absorbing SO ₂ is converted into ammonium sulfite by adding ammonia and then the ammonia desulfurization is performed.

The absorption tower may have a flue gas inlet and multiple zones, and one or more of the following stages are located based on flue gas parameters: inlet, control after pre-wash (if this stage exists), after absorption, after fine particle control, and after discharge. The location can also depend on the presence of a pre-wash control zone, the number of spray layers in the zone, the degree of oxidation of the absorbing fluid in the oxidation system, and the degree of post-treatment concentration. The flue gas inlet position can be 10-40% of the tower body height, the pre-washing zone height can be 10-40% of the tower body height, the absorption zone height can be 10-35% of the tower body height, and the fine particle control zone height It can be 15-70% of the tower height.

The ratio of the diameter of the absorption tower to the diameter of the oxidation vessel may be 0.5-3, and the height of the oxidation vessel may be 0.3-6 times the diameter of the absorption tower.

The gas velocity of the absorption tower can be 1 m/s-5 m/s. The operating temperature of the pre-washing zone may be 40°C-80°C.

The absorption temperature can be controlled according to the flue gas parameters, and the boiler flue gas is generally controlled at 40-60°C. Sulfur recovery waste gas and incineration flue gas are generally controlled at 50-70℃. Dry sulfuric acid waste gas is generally controlled at 30-45℃.

Under the condition that the original flue gas SO ₂ concentration is not more than 30,000mg/Nm ³ , the net flue gas can meet the most stringent emission standards or process requirements in the world. The device can be adjusted and designed according to the specific project requirements to reduce investment and operation. Cost, improve cost performance.

The net flue gas SO ₂ may not be greater than 200 mg/Nm ³ , for example, not greater than 100 mg/Nm ³ , or 35 mg/Nm ³ , or 5 mg/Nm ³ .

The net total flue gas dust (including aerosol) may not be greater than 20 mg/Nm ³ , such as 10 mg/Nm ³ , or 5 mg/Nm ³ , or 2 mg/Nm ³ .

The net flue gas ammonia escape may not be greater than 5 mg/Nm ³ , such as 2 mg/Nm ³ , or 1 mg/Nm ³ , or 0.5 mg/Nm ³ .

When the requirements of the emission index are low, it can be reduced by reducing the number of stages and/or the number of spray layers and/or circulation of the absorption cycle, fine particle washing cycle, and/or increasing the ammonium sulfite content and pH value of the absorption liquid Investment and operating costs.

When the emission requirements are strict, by increasing the number of absorption cycles, fine particle washing cycles and/or the number of spray layers and/or circulation, and/or accurately controlling the ammonium sulfite content and pH value of the absorption liquid Emissions can be qualified or can meet the needs of post-process production.

The mass fraction ratio of ammonium sulfate and ammonium sulfite in the one-stage or multi-stage absorption circulating fluid can be 1.5-199:1, such as 9-99:1.

The mass fraction ratio of ammonium sulfate and ammonium sulfite in the circulating washing liquid of one-stage or multi-stage fine particles can be 3-1999:1, such as 9-999:1.

When it is necessary to control harmful ions such as chloride ions and fluoride ions in the circulating solution, some fine particles can be directly made into ammonium sulfate by circulating washing liquid. The chloride ion content in the circulating solution can be lower than 50000mg/L, such as 10000-31000mg/L, and the fluoride ion concentration can be lower than 20000mg/L, such as 300-3000mg/L. Selected illustrative implementation options:

1. A method for controlling the generation of aerosol in the absorption process by ammonia desulfurization, characterized in that the absorption circulating liquid containing ammonium sulfite is used to remove sulfur dioxide in flue gas to control the generation of aerosol in the absorption process by ammonia desulfurization.

2. The method according to embodiment 1, characterized in that high-efficiency desulfurization and dedusting are achieved by controlling the composition of the graded solution and the control of the reaction conditions, while controlling the escape of ammonia and the generation of aerosol while desulfurizing and dedusting efficiently.

3. The method according to embodiment 2, wherein the fractional solution composition control includes concentration gradient control of ammonium sulfite, ammonium bisulfite, ammonium sulfate, or a combination thereof.

4. The method according to embodiment 2, characterized in that the flue gas after the initial cooling and purification is sequentially contacted with the absorption circulating fluid and the fine particulate washing circulating fluid to realize the coordinated control of absorption, oxidation and concentration, and the absorption circulating fluid is as required Set 1 or more levels, of which one or more levels contain ammonium sulfite and ammonium sulfate, and the fine particulate washing cycle liquid is set to one or more levels as needed, of which one or more levels contain ammonium sulfite and ammonium sulfate.

5. The method according to embodiment 4, characterized in that the pH value of the fine particulate washing circulating liquid is lower than the pH value of the absorption circulating liquid, and the content of ammonium sulfite is less than that of the absorption circulating liquid.

6. The method according to embodiment 2, wherein the absorption temperature and the washing temperature are controlled within an appropriate range to reduce energy consumption while ensuring absorption efficiency, controlling ammonia slip, and aerosol.

7. The method according to embodiment 4, characterized in that, when multi-stage absorption circulation liquid is selected, the first-stage or multi-stage components include ammonium sulfite 0.15-4.95%, ammonium sulfate 5-38%, pH value 4-6.6, The ammonium sulfite content of the upper absorption circulation liquid is lower than that of the lower absorption circulation liquid, and/or the pH value of the upper absorption circulation liquid is lower than the pH value of the lower absorption circulation liquid.

8. The method according to embodiment 4, characterized in that the absorption circulating fluid is of grade 1-2, for example grade 1.

9. The method according to embodiment 4, the first-stage or multi-stage components of the fine particulate washing circulating liquid include ammonium sulfite 0.003-1%, ammonium sulfate 0.3-38%, and pH value 3-5.4.

10. The method according to embodiment 9, wherein the fine particulate washing circulating liquid is grade 2, and the grade one of the grade contains high concentration of ammonium sulfate, wherein ammonium sulfite is 0.1-1% and ammonium sulfate is 5-38%.

11. The method according to embodiment 6, characterized in that the absorption temperature is 30-70°C, for example 35-60°C, or 45-55°C.

12. The method according to embodiment 6, wherein the washing temperature is 28-68°C, for example 30-55°C, or 40-50°C.

13. An ammonia desulfurization device for controlling the production of aerosol by implementing the method according to any one of embodiments 1-12, characterized in that it includes a gas purification and removal system, an oxidation system, and an auxiliary system.

14. The device according to embodiment 13, wherein the auxiliary system includes an ammonium sulfate post-treatment system, an ammonia supply system, and a process water system.

15. The apparatus according to embodiment 13, wherein the absorption tower of the gas purification and removal system adopts zone control, including a pre-wash zone, an absorption zone, and a fine particulate matter control zone, wherein the pre-wash zone, the absorption zone, and the fine particulate matter control zone One or more spray layers are set for each. Between the absorption zone and the pre-washing zone, there are devices/components that only allow gas to pass through.

16. The device according to embodiment 15, characterized in that between the absorption zone and the fine particle control zone, devices/components that only allow gas to pass are provided as needed.

17. The device according to embodiment 15, characterized in that the absorption zone is provided with devices/components that only allow gas to pass through as needed.

18. The device according to embodiment 15, wherein the fine particulate matter control area is provided with devices/components that only allow gas to pass as needed.

19. The device according to embodiment 15, characterized in that the fine particle control zone is provided with one or more layers of demisters, and each layer of the pre-washing zone and the absorption zone is provided with one or more layers of demisters as required; the demister is selected Types of baffles, ridges, fillers and wire mesh, or combinations thereof.

20. The device according to embodiment 15, wherein the liquid-gas ratio of each layer in the absorption zone is not less than 0.2 L/Nm ³ and the spray coverage is not less than 110%; the liquid-gas ratio of each layer in the fine particle control zone is not less than 20. 0.1 L/Nm ³ , spray coverage is not less than 105%.

21. The device according to embodiment 13, characterized in that the oxidation system sets layers or equipment according to the solution composition control requirements, and the fine particulate matter washing circulating liquid and absorption circulating liquid are taken out from different positions of the oxidation system oxidation container or different equipment.

22. The device according to embodiment 21, characterized in that one to five layers of gas-liquid dispersion intensifiers are set in the oxidation vessel of the oxidation system.

23. The device according to embodiment 22, wherein the gas-liquid dispersion intensifier can use one or a combination of structured packing, random packing, perforated plate, gas cap, and aeration head.

24. The device according to embodiment 21, wherein the liquid level of the oxidation vessel of the oxidation system is greater than 3 m, and the oxidation air is more than 20% excess.

25. The device according to any one of embodiments 13-24, characterized in that: The flue gas enters from the pre-washing zone, is cooled and washed by the circulating washing liquid in the pre-washing zone, and the circulating washing liquid is concentrated at the same time. The flue gas is then desulfurized by the absorption circulating liquid in the absorption zone, and the fine particulate control zone is removed by the fine particulate circulating washing liquid Discharge after fine particles; The circulating washing liquid in the pre-washing area is mainly replenished from the circulating washing liquid of fine particles. The circulating washing liquid of fine particles and/or process water is used to rinse the scale deposits on the tower wall. The absorption of circulating liquid is supplemented by the circulating washing liquid and/or process water of the control area of fine particles ;with The absorption circulating fluid is oxidized in the oxidation system, and solutions of different compositions are drawn from different locations or equipment of the oxidation vessel of the oxidation system to be circulated separately.

26. The apparatus of embodiment 25, wherein the process water is replenished from the fine particle control zone.

27. The device according to embodiment 25, wherein the preliminary cooling and purification scheme is cooling and dust removal with circulating washing liquid.

28. The device according to embodiment 15, wherein the position of the flue gas inlet is 10-40% of the height of the tower, the height of the pre-washing zone is 10-40% of the height of the tower, and the height of the absorption zone is the tower 10-35% of the height, the height of the fine particle control area is 15-70% of the height of the tower.

29. The device according to embodiment 21, wherein the ratio of the diameter of the absorption tower to the diameter of the oxidation vessel is 0.5-3, and the height of the oxidation vessel is 0.3-6 times the diameter of the absorption tower.

30. The device according to embodiment 25, wherein the gas velocity of the absorption tower is 1 m/s-5 m/s; and/or the operating temperature of the pre-washing zone is 40°C-80°C.

31. The device according to embodiment 25, wherein the original flue gas SO ₂ concentration is ≤30,000 mg/Nm ³ .

32. The device according to embodiment 31, characterized in that the net flue gas can meet the most stringent emission standards or process requirements in the world, and optimize the design of the device according to the specific project requirements to reduce investment and operating costs and improve cost performance .

33. The apparatus according to embodiment 31, wherein, the net flue gas SO ₂ ≤200mg / Nm ^3, e.g. ≤100mg / Nm ^3, or ≤35mg / Nm ^3, or ≤5mg / Nm ^3.

34. The device according to embodiment 32, characterized in that the net total flue gas dust (including aerosol) ≤ 20 mg/Nm ³ , for example ≤ 10 mg/Nm ³ , or ≤ 5 mg/Nm ³ , or ≤ 2 mg/Nm ³ .

35. The apparatus according to embodiment 32, wherein, the net flue gas ammonia slip ≤5mg / Nm ^3, preferably ≤2mg / Nm ^3, or ≤1mg / Nm ^3, or ≤0.5mg / Nm ^3.

36. The device according to embodiment 25, wherein when it is necessary to control the harmful ions of chlorine and fluorine in the circulating solution, a drying device is used to directly make part of the absorption liquid into a solid product.

37. The device according to embodiment 36, characterized in that the chloride ion content in the circulating solution is lower than 50,000 mg/L, for example 10,000-31,000 mg/L, and the fluoride ion concentration is lower than 20,000 mg/L, for example 300-3,000 mg/L.

38. The device according to embodiment 21, characterized in that the composition of the solution is controlled by forced oxidation and/or natural oxidation and/or pre-washing liquid into the absorption zone and/or by controlling the operating temperature through an oxidation vessel.

39. The device according to embodiment 25, wherein the mass fraction ratio of ammonium sulfate to ammonium sulfite in the one-stage or multi-stage absorption circulating fluid is 1.5-199:1.

40. The device according to embodiment 20, wherein the mass fraction ratio of ammonium sulfate to ammonium sulfite in the one-stage or multi-stage fine particulate matter circulating washing liquid is 3-1999:1.

The devices and methods described herein are illustrative. The device and method according to the invention will now be described in conjunction with the accompanying drawings, which form part of the invention. The drawings show illustrative features of apparatus and method steps in accordance with the principles of the present invention. It should be understood that other embodiments may be used, and structural, functional, and procedural modifications may be made without departing from the scope and spirit of the invention.

The steps of the method may be performed in an order different from that shown herein and/or in that order. Embodiments may omit the illustration and/or this step related to the illustrative method. Embodiments may include steps that are neither shown nor described in connection with the illustrative method. Illustrative method steps can be combined. For example, one illustrative method may include the illustrated steps related to another illustrative method.

Some devices may omit features shown and/or described in relation to illustrative devices. Embodiments may include features that are neither shown nor described in relation to the illustrative method. The characteristics of illustrative devices can be combined. For example, one illustrative embodiment may include the illustrated features related to another illustrative embodiment.

The apparatus and method of the present invention will be described in conjunction with the embodiments and features of the illustrative apparatus. The device will now be described with reference to the drawings in the attached drawings, which form part of the invention.

As shown in Figure 1, the method of ammonia desulfurization to control the generation of aerosol in the absorption process, using an absorption circulating liquid containing ammonium sulfite to remove sulfur dioxide in the flue gas, to control the generation of aerosol in the ammonia desulfurization absorption process.

By controlling the composition of the graded solution and the control of the reaction conditions, high-efficiency desulfurization and dust removal can be achieved while controlling ammonia slip and aerosol generation.

The fractional solution composition control may include concentration gradient control of ammonium sulfite, ammonium bisulfite, ammonium sulfate, or a combination thereof.

The flue gas can enter from the pre-washing zone, and the flue gas after preliminary cooling and purification in the pre-washing zone can sequentially contact the absorption circulating liquid 7 and the fine particle circulating washing liquid 15 to realize the coordinated control of absorption, oxidation, and concentration. A single-stage absorption circulating fluid can be set, which includes ammonium sulfite 1%, ammonium sulfate 22%, pH 6.1, and absorption temperature 50°C. Can set 3 levels of fine particulate washing circulating liquid, of which the lower level is a high concentration ammonium sulfate-ammonium sulfite mixed solution, including 0.17% ammonium sulfite, 22% ammonium sulfate, pH 4.5, washing temperature 49.3 ℃, the second level is dilute Ammonium sulfate-ammonium sulfite mixed solution, including ammonium sulfite 0.01%, ammonium sulfate 1.5%, pH value 4.3, washing temperature 48 ℃, the third level is process water.

Configurable device to control aerosol production during absorption. The device may include a gas purification and removal system, an oxidation system, and an auxiliary system. The auxiliary system may include an ammonium sulfide aftertreatment system, an ammonia supply system, and a process water system.

The gas purification and removal system may include an absorption tower 1, a fine particle washing circulation tank 3, a pre-washing circulation pump, and a fine particle washing circulation pump. The absorption tower 1 can be controlled by zones, divided into pre-washing zone 4, absorption zone 5, and fine particulate matter control zone 6, pre-wash zone 4, absorption zone 5, and fine particulate matter control zone 6 can be set to 3/3/5 layers respectively In the shower layer, a gas-liquid separator a 17 may be provided between the absorption zone 5 and the pre-wash zone 4 to allow only gas to pass and liquid to be drawn from the side or the lower part. The fine particle control zone can be divided into three spray layers, of which a gas-liquid separator b 18.1 can be provided between the second layer spray and the third layer spray to allow only gas passage and liquid to be drawn from the side or the lower part. -2 layers of fine particulate washing circulation liquid 15 can be mixed with the absorption circulation liquid 7 and flow into the oxidation vessel.

The fine particle control area can be equipped with 7 layers of demisters, 3 layers below the gas-liquid separator b, including 1 layer of baffles and 2 layers of roofs, and 4 layers below the net flue gas outlet, including 1 layer of baffles, 2 layers of roof and 1 layer of wire mesh.

Each layer of liquid gas in the absorption zone can be 1.5L/Nm ³ , and the spray coverage can be 300%. The liquid-gas ratio of each layer of the fine particle control area can be 0.15 L/Nm ³ , 1.1 L/Nm ³ , 1.3 L/Nm ³ , 0.15 L/Nm ³ , 1.5 L/Nm ³ , and the spray coverage can be 105 respectively %, 250%, 280%, 105%, 300%.

The oxidation system may include an oxidation vessel 2 in which the oxidation device 2 may set a layer according to the requirements of solution composition control. The fine particle washing circulation liquid 15 and the absorption circulation liquid 7 can be taken out from different positions of the oxidation container. Five layers of gas-liquid dispersion intensifiers can be installed in the oxidation vessel. The gas-liquid dispersion intensifier uses perforated plates.

The oxidation vessel may have a liquid level of 8 m, and the oxidation air is over 200%.

The equipment and methods may include the following illustrative processes: The flue gas enters from the pre-washing zone 4, the washing liquid is cooled and washed by the circulating washing liquid in the pre-washing zone 4, and the circulating washing liquid is concentrated at the same time, and the flue gas is washed and desulfurized by the absorption circulating liquid 7 through the absorption zone 5 respectively, and the fine particle control zone 6 is fine Particulate circulating washing liquid 15 is discharged after removing fine particles; The pre-washing zone 4 circulating washing liquid is mainly replenished by the fine particulate circulating washing liquid 15, the fine particulate circulating washing liquid 15 and/or the process water 23 is used to rinse the scales of the tower wall, etc., and the absorption circulating liquid is circulating through the fine particulate circulating washing liquid 15 and /Or process water 23 supplement; and The absorption circulation liquid 7 is oxidized in the oxidation vessel 2 and solutions of different components are drawn from different positions of the oxidation vessel 2 to be circulated separately.

The absorption circulating fluid containing ammonium sulfite can be used to remove sulfur dioxide in the flue gas. Ammonia added to the absorption circulating fluid can be converted into ammonium sulfite before ammonia desulfurization. At the same time, ammonia can be added to the pre-wash area to ensure ammonium sulfate products. The medium free acid index meets the requirements of GB535.

The process water 23 can be replenished from the fine particle control area 6 and the fine particle washing circulation tank 3. The location of the flue gas inlet can be 12% of the height of the tower body of the absorption tower 1. The height of the pre-washing zone 4 may be 20% of the height of the tower body. The height of the absorption zone 5 may be 15% of the height of the tower body. The height of the fine particle control zone 6 may be 65% of the height of the tower body.

The diameter ratio of the absorption tower 1 to the oxidation vessel 2 may be 1.5, and the height of the oxidation vessel 2 may be 1.4 times the diameter of the absorption tower 1.

The gas velocity of the absorption tower 1 can be 2.75 m/s; the operating temperature of the pre-washing zone 4 can be 55°C.

Flue gas flow rate can be 186,000Nm ³ /h, SO ₂ concentration can be 3000mg/Nm ³ , total dust concentration can be 19.6mg/Nm ³ , net flue gas SO ₂ can be 79.4mg/Nm ³ , total dust (gas Sol) can be 6.5 mg/Nm ³ and ammonia slip can be 1.8 mg/Nm ³ .

The composition of the solution can be controlled mainly by the forced oxidation of the oxidation container 2 and the operation temperature.

The mass fraction ratio of ammonium sulfate and ammonium sulfite in the absorption circulating liquid 7 can be 22:1.

The mass fraction ratio of ammonium sulfate and ammonium sulfite in the bottom fine particle circulating washing liquid 15 may be 129.4:1. Examples

The following examples are given for illustrative purposes and are not intended to limit the scope of the present invention. The application of the principles of the present invention is not limited to the conditions listed in the embodiments, and it should be understood that these principles include various changes and modifications to the embodiments described herein, and such changes and modifications can be made without departing from the spirit and scope of the present invention . Example 1

1. An ammonia desulfurization method to control the generation of aerosol in the absorption process The absorption circulating fluid containing ammonium sulfite is used to remove sulfur dioxide in flue gas to control the generation of aerosol during absorption by ammonia desulfurization.

By controlling the composition of the graded solution and the control of the reaction conditions, high-efficiency desulfurization and dedusting can be achieved while controlling the escape of ammonia and the generation of aerosols.

The composition control of the graded solution includes one or more concentration gradient control of ammonium sulfite, ammonium bisulfite, and ammonium sulfate.

The flue gas enters from the pre-washing area of the absorption tower, and the flue gas after preliminary cooling and purification in the pre-washing area contacts the absorption circulating liquid 7 and the fine particulate washing circulating liquid 15 in order to achieve coordinated control of absorption, oxidation, and concentration. The absorption circulation liquid is set to 2 levels, taken out from different positions of the oxidation container and transported by an independent pump. The first-stage absorption circulating fluid includes ammonium sulfite 1.5%, ammonium sulfate 24%, pH 6.3, absorption temperature 51 ℃, the second-stage absorption circulation fluid includes ammonium sulfite 0.9%, ammonium sulfate 24%, pH 5.5, absorption The temperature is 50.8℃, and the fine particle washing circulating liquid is set to 3 levels, of which the first level is a high concentration ammonium sulfate-ammonium sulfite mixed solution, including ammonium sulfite 0.15%, ammonium sulfate 24%, pH value 4.5, washing temperature 50.5℃, The second level is dilute ammonium sulfate-ammonium sulfite mixed solution, including ammonium sulfite 0.02%, ammonium sulfate 2%, pH value 4.2, washing temperature 49.8℃, and the third level is process water. 2. An ammonia desulfurization device for controlling aerosol generation during absorption

The device mainly includes a gas purification and removal system, an oxidation system, and an auxiliary system. Auxiliary systems include ammonium sulfide aftertreatment system, ammonia supply system, and process water system.

The gas purification and removal system includes an absorption tower 1, a fine particle washing circulation tank 3, a pre-washing circulation pump, and a fine particle washing circulation pump. The absorption tower 1 is controlled by zones, and is mainly divided into a pre-washing zone 4, an absorption zone 5, and a fine Particulate control zone 6, pre-wash zone 4, absorption zone 5, and fine particulate matter control zone 6 are each set with 3/3/4 layers of spray layer, and between the absorption zone 5 and pre-wash zone 4, only gas is allowed Gas-liquid separator a 17. There is also a gas-liquid separator 17 between the absorption zone 5 and the fine particle control zone 6 that only allows gas to pass through. The fine particle control zone 6 is divided into three spray layers, of which the first layer is sprayed and the second layer is sprayed There is a gas-liquid separator b 18 that only allows gas to pass through. The spraying liquid and absorption circulating liquid of the first layer enter the oxidation container respectively.

There are 5 layers of demisters in the fine particle control area, 2 layers below the gas-liquid separator b, including 1 layer of baffles and 1 layer of ridge, and 3 layers below the net flue gas outlet, including 1 layer of ridge and 2 layers of wire network.

In the absorption zone, there are 2 layers of baffle defogger.

The liquid-gas ratio of each layer in the absorption zone is 1.6L/Nm ³ , and the spray coverage is 320%; the liquid-gas ratio of each layer from the top to the bottom of the fine particle control area is 0.2/1.2/1.3/1.6 L/Nm ³ , spray coverage The rates are 110%/260%/290%/320%.

The oxidation system includes an oxidation vessel 2 in which the oxidation device 2 sets layers according to the requirements of the solution composition control. The fine particulate matter washing circulating liquid 15 and the absorption circulating liquid 7 are taken out from the oxidation vessel 2 at different positions. There are 5 layers of gas-liquid dispersion intensifier in the oxidation vessel. The gas-liquid dispersion intensifier uses perforated plates and aeration heads.

The level of the oxidation vessel is 9.3m, and the excess of oxidation air is 250%. 3. The process flow and parameters of a method of ammonia desulfurization to control the generation of aerosol in the absorption process

The equipment and method may include the following instructions for the manufacturing process: The flue gas enters from the pre-washing zone 4, is cooled and washed by the circulating washing liquid in the pre-washing zone 4, and the circulating washing liquid is concentrated at the same time. The flue gas is then desulfurized by the absorption circulating fluid 7 through the absorption zone 5 and desulfurized, and is finely divided by the fine particle control zone The particulate matter circulating washing liquid 15 is discharged after removing fine particulate matter.

The circulating washing liquid in the pre-washing zone 4 is mainly supplemented by the fine particle circulating washing liquid 15, the fine particle circulating washing liquid 15 and/or the process water 23 is used to rinse the scales of the tower wall, etc., and the absorption circulating liquid is circulated through the fine particle circulating washing liquid 15 and/ Or process water 23 supplement.

The absorption circulation liquid 7 is oxidized in the oxidation vessel 2, and solutions of different components are drawn from different positions of the oxidation vessel 2 to the absorption zone 5 and the fine particle control zone 6 for circulation.

The process water 23 is replenished from the fine particle control area 6 and the fine particle washing circulation tank 3.

The second stage fine particle washing cycle liquid 15 (dilute ammonium sulfate-ammonium sulfite mixed solution) is mixed with the first stage fine particle washing cycle liquid 15 (high concentration ammonium sulfate-ammonium sulfite mixed solution) through a pipe, and then absorbed The spray layer in the fine particle control area 6 of tower 1 is sprayed.

The absorbent is 20% ammonia water, supplement the pre-wash area 4, the oxidation container 2, and use the absorption circulating liquid containing ammonium sulfite to remove the sulfur dioxide in the flue gas. Ammonia is added to the oxidation vessel and converted to ammonium sulfite before ammonia desulfurization. At the same time, ammonia is added in the pre-wash area to ensure that the free acid index in the ammonium sulfate product meets the requirements of GB535.

The oxidized air is added to the oxidation vessel 2, and the gas at the outlet of the oxidation vessel 2 is introduced into the absorption zone 4 of the absorption tower 1 to naturally oxidize the absorption liquid.

The flue gas inlet is located at 11% of the height of the tower body of the absorption tower 1, the height of the pre-washing zone 4 is 21% of the tower body height, the height of the absorption zone 5 is 20% of the tower body height, and the height of the fine particle control zone 6 is the tower body 59% of height.

The diameter ratio of the absorption tower 1 to the oxidation vessel 2 is 1.1, and the height of the oxidation vessel 2 is 1.2 times the diameter of the absorption tower 1.

The gas velocity of the absorption tower 1 is 2.68 m/s; the operating temperature of the pre-washing zone 4 is 56°C.

The designed flue gas flow is 510,000Nm ³ /h, the designed SO ₂ concentration is 5000mg/Nm ³ , and the designed total dust concentration is not more than 25mg/Nm ³ .

During the test, the net flue gas SO ₂ was 21 mg/Nm ³ , the total dust (including aerosol) was 1.3 mg/Nm ³ , and ammonia escaped 0.8 mg/Nm ³ .

4、實施效果The composition of the zoned solution is controlled mainly by means of forced oxidation in the oxidation vessel 2, natural oxidation in the absorption zone 4, and control of the operating temperature. Table 1 Device design parameters

4. Implementation effect

表3 裝置運行參數和及測試結果

實施例2The apparatus and method of Example 1 are used to perform flue gas desulfurization and dedusting on flue gas of different working conditions. Table 2 shows the test methods and test instruments, and Table 3 shows the operating parameters and test results. Table 2 Test methods of various indicators and a list of main instruments

Table 3 Device operating parameters and test results

Example 2

1. An ammonia desulfurization method to control the generation of aerosol in the absorption process The absorption circulating fluid containing ammonium sulfite is used to remove sulfur dioxide in flue gas to control the generation of aerosol during absorption by ammonia desulfurization.

By controlling the composition of the graded solution and the control of the reaction conditions, high-efficiency desulfurization and dedusting can be achieved while controlling the escape of ammonia and the generation of aerosols.

The composition control of the graded solution includes one or more concentration gradient control of ammonium sulfite, ammonium bisulfite, and ammonium sulfate.

The flue gas enters from the pre-washing zone, and the flue gas after preliminary cooling and purification in the pre-washing zone contacts the absorption circulating liquid 7 and the fine particulate washing circulating liquid 15 in order to achieve coordinated control of absorption, oxidation, and concentration. The absorption circulating fluid is set to 2 levels, taken from different positions of the absorption circulation tank 16 and transported by an independent pump. The first-stage absorption circulating fluid includes ammonium sulfite 2%, ammonium sulfate 27%, pH 6.4, absorption temperature 49 ℃, the second-stage absorption circulation fluid includes ammonium sulfite 1.1%, ammonium sulfate 27.9%, pH 5.7, absorption The temperature is 48.7℃, and the fine particle washing circulating liquid is provided with 4 stages, of which the first stage is a high concentration ammonium sulfate-ammonium sulfite mixed solution, including ammonium sulfite 0.2%, ammonium sulfate 28.8%, pH value 4.9, washing temperature 48.5℃ , The second level is dilute ammonium sulfate-ammonium sulfite mixed solution, including ammonium sulfite 0.03%, ammonium sulfate 3.7%, pH value 4.3, washing temperature 48.2℃, the third level is lower concentration dilute ammonium sulfate-ammonium sulfite The mixed solution includes ammonium sulfite 0.005%, ammonium sulfate 0.5%, pH value 4.25, washing temperature 48.1°C, and the fourth stage is process water. 2. An ammonia desulfurization device for controlling aerosol generation during absorption

The device mainly includes gas purification and removal system, oxidation system and auxiliary system. Auxiliary systems include ammonium sulfide aftertreatment system, ammonia supply system, and process water system.

The gas purification and removal system includes an absorption tower 1, an absorption circulation tank 16, a fine particulate washing circulation tank a 3, a fine particulate washing circulation tank b 3, and a pre-washing circulation pump, an absorption circulation pump, and a fine particulate washing circulation pump. Tower 1 adopts zone control, which is mainly divided into pre-washing zone 4, absorption zone 5, and fine particle control zone 6. Pre-wash zone 4, absorption zone 5, and fine particulate matter control zone 6 are respectively set with 3/4/5 spray layers. A gas-liquid separator a 17 is provided between the absorption zone 5 and the pre-wash zone 4 to allow only gas to pass through. There is also a gas-liquid separator a 17 that only allows gas to pass between the absorption zone 5 and the fine particle control zone 6, and between the primary absorption (2-layer spray) and the secondary absorption (2-layer spray) in the absorption zone 5. 1. Between the first layer spray and the second layer spray in the fine particle control zone 6, the third layer and the fourth layer spray in the fine particle control zone are provided with a gas-liquid separator b 18 that only allows gas to pass through. The absorption circulation liquid 7 enters the absorption circulation tank, the first layer fine particle circulation washing liquid 15 enters the oxidation vessel 2, the second layer and third layer fine particle circulation washing liquid 15 enters the fine particle washing circulation tank a 3, the fourth layer, the first The five-layer fine particle circulation washing liquid 15 enters the fine particle washing circulation tank b3.

There are 7 layers of demisters in the fine particle control area. The gas-liquid separator between the first layer and the second layer of spray b 18 is 2 layers, including the roof of 2 layers, and the gas-liquid separation between the third layer and the fourth layer of spray Below b 18, there are 2 layers, including 1 layer of ridge and 1 layer of wire mesh, and below the net flue gas outlet 8 is 3 layers, including 1 layer of ridge and 2 layers of wire mesh.

The absorption zone is provided with a layer of baffle defogger and a layer of ridge defogger.

The liquid-gas ratio of each layer in the absorption zone is 2.1 L/Nm ³ , and the spray coverage is 400%; the liquid-gas ratio of each layer from the top to the bottom of the fine particle control area is 0.16/2.1/1.4/1.4/2.1 L/Nm ³ , respectively. The shower coverage rate is 110%/400%/300%/300%/400%.

The absorption circulation tank 16 is set in layers according to the requirements of the solution composition control. The primary absorption circulation liquid 7 and the secondary absorption circulation liquid 7 are taken out from the absorption circulation tank 2 at different positions. Two layers of gas-liquid dispersion intensifiers are set in the absorption circulation tank 16 as structured packing.

The oxidation system includes an oxidation vessel 2. Five layers of gas-liquid dispersion intensifiers are set in the oxidation vessel. The gas-liquid dispersion intensifier uses perforated plates and aeration heads.

Oxidation vessel 2 liquid level 10m.

The oxidation air added to the absorption circulation tank 16 and the oxidation vessel 2 is 350% excess.

The ammonium sulfate post-treatment system is equipped with a drying tower, which directly converts part of the fine particles circulating washing liquid into ammonium sulfate to control the content of chloride and fluoride ions in various circulating solutions. 3. The process flow and parameters of a method of ammonia desulfurization to control the generation of aerosol in the absorption process

The specific process flow of the above method or device is: The flue gas enters from the pre-washing zone 4, the washing liquid is cooled and washed by the circulating washing liquid in the pre-washing zone 4, and the circulating washing liquid is concentrated at the same time. The flue gas is then washed and desulfurized by the absorption circulating liquid 7 through the absorption zone 5, and the fine particulate control zone 6 is fine The particulate matter circulating washing liquid 15 is discharged after removing fine particulate matter.

The pre-washing zone 4 circulating washing liquid is mainly supplemented from the fine particulate matter circulating washing liquid 15. The fine particulate matter circulating washing liquid 15 and/or the process water 23 are used to wash the tower wall fouling, and the absorption circulating fluid is circulated by the fine particulate matter washing liquid 15 and/or Process water 23 supplement.

The absorption circulation liquid 7 is oxidized in the absorption circulation tank 16, and solutions of different components are drawn from different positions of the absorption circulation tank 16 to perform primary absorption and secondary absorption, respectively.

The process water 23 is replenished from the fine particle control area 6 and the fine particle washing circulation tank 3.

The second-stage and third-stage fine particle washing circulation liquid 15 (dilute ammonium sulfate-ammonium sulfite mixed solution) supplements the oxidation vessel 2.

The fourth stage fine particle washing circulation liquid 15 supplements the fine particle washing circulation tank 3.

The first-stage fine particulate washing circulation liquid 15 supplements the absorption circulation tank 16.

The absorption agent is liquid ammonia, which mainly supplements the absorption circulation tank 16, and the absorption circulation liquid containing ammonium sulfite is used to remove sulfur dioxide in the flue gas. Ammonia is added to the absorption circulation tank 16 to be converted into ammonium sulfite and then used for ammonia desulfurization.

Add ammonia to the pre-washing zone 4 to adjust the pH to ensure that the product's ammonium sulfate free acid index meets the requirements of GB535, and add ammonia to the oxidation vessel 2 to adjust the pH.

The oxidized air is added to the oxidation vessel 2 and the absorption circulation tank 16, and the gas at the outlet of the oxidation vessel 2 and the absorption circulation tank 16 is introduced into the absorption zone 4 of the absorption tower 1 to naturally oxidize the absorption liquid.

The flue gas inlet is located at 7% of the tower body height of the absorption tower 1, the height of the pre-wash zone 4 is 17% of the tower body height, the height of the absorption zone 5 is 25% of the tower body height, and the height of the fine particle control zone 6 is the tower body 58% of the height.

The diameter ratio of the absorption tower 1 to the oxidation vessel 2 is 0.85, and the height of the oxidation vessel 2 is 1.25 times the diameter of the absorption tower 1.

The gas velocity of the absorption tower 1 is 2.64 m/s; the operating temperature of the pre-washing zone 4 is 51°C.

The designed flue gas flow is 350,000Nm ³ /h, the designed SO ₂ concentration is 15000mg/Nm ³ , the designed hydrogen chloride content is 100mg/Nm ³ , and the designed total dust concentration is not more than 30mg/Nm ³ .

The flue gas has high sulfur dioxide content. After water balance calculation and analysis, it is necessary to send 10-20% of the high-concentration fine particles circulating washing liquid to the evaporative crystallization system for separate treatment. The remaining high-concentration fine particles circulating washing liquid can be concentrated and crystallized in the pre-washing area of the absorption tower . Considering that the flue gas hydrogen chloride content of the tower design is as high as 100mg/Nm ³ , the drying equipment (instead of the evaporative crystallization system) is selected, and the 10-20% high-concentration fine particle circulating washing liquid is directly dried in the drying equipment to remove the chloride ions in the circulating liquid The concentration is controlled at 10000-30000mg/L, and the concentration of fluoride ion is controlled at 500-2800mg/L.

During the test, the net flue gas SO ₂ was 3.4 mg/Nm ³ , the total dust (including aerosol) was 0.9 mg/Nm ³ , and ammonia escaped 0.25 mg/Nm ³ .

4、實施效果The composition of the zoned solution is controlled mainly by means of forced oxidation in the oxidation vessel 2, forced oxidation in the absorption circulation tank 16, natural oxidation in the absorption zone 4, control of the operating temperature and so on. Table 4 Device design parameters

4. Implementation effect

表6 裝置運行參數和及測試結果

The apparatus and method of Example 2 are used to perform flue gas desulfurization and dust removal for flue gas of different working conditions. Table 5 shows the test methods and test instruments, and Table 6 shows the operating parameters and test results. Table 5 Test methods of various indicators and a list of main instruments

Table 6 Device operating parameters and test results

Therefore, an apparatus and method for controlling aerosol generation in the process of absorbing sulfur dioxide from flue gas are provided. Those skilled in the art will appreciate that the present invention can be practiced in addition to this embodiment, and that the existence of this embodiment is for illustration rather than limitation. The invention is limited only by the scope of the following patent applications.

1: absorption tower 2: oxidation container 3: Fine particles washing circulation tank 4: Pre-wash area 5: Absorption zone 6: Fine particle control area 7: Absorb circulating fluid 8: Net flue gas outlet 9: Smoke import 10: Pre-wash spray layer 11: Absorption spray layer 12: fine particle spray layer a 13: fine particle spray layer b 14: defogger 15: Fine particles circulating washing liquid 16: Absorption circulation tank 17: gas-liquid separator a 18: gas-liquid separator b 19: gas-liquid dispersion intensifier 21: Ammonia 22: Oxidized air 23: Process water 24: ammonium sulphate aftertreatment system

Considering the following detailed description in conjunction with the accompanying drawings, the objects and advantages of the present invention will become apparent, wherein the same reference numerals always denote the same parts, and wherein: Figure 1 is a schematic diagram of a method and device in accordance with the principles of the present invention. Figure 2 is a schematic diagram of Example 1. Figure 3 is a schematic diagram of Example 2.

1: absorption tower

2: oxidation container

3: Fine particles washing circulation tank

4: Pre-wash area

5: Absorption zone

6: Fine particle control area

7: Absorb circulating fluid

8: Net flue gas outlet

9: Smoke import

10: Pre-wash spray layer

11: Absorption spray layer

12: fine particle spray layer a

13: fine particle spray layer b

14: defogger

15: Fine particles circulating washing liquid

17: gas-liquid separator a

18: gas-liquid separator b

19: gas-liquid dispersion intensifier

21: Ammonia

22: Oxidized air

23: Process water

24: ammonium sulphate aftertreatment system

Claims (53)

A method for controlling the generation of aerosol in the process of absorbing sulfur dioxide from flue gas is characterized in that the method includes applying a gradient of ammonium salt to the flue gas. The method as described in item 1 of the patent application scope further includes applying a reaction condition gradient to a flue gas. The method according to item 1 of the patent application scope, wherein the application of the ammonium salt gradient includes: Apply a first ammonium salt concentration in the first stage; and Apply a second ammonium salt concentration in the second stage; Compared with the flue gas, the first stage is upstream of the second stage. The method of claim 3, wherein the salt includes ammonium sulfite, ammonium bisulfite, or ammonium sulfate. The method of claim 3, wherein the first-level concentration is greater than the second-level concentration. The method according to item 5 of the patent application scope, wherein applying the first ammonium salt concentration in the first stage includes spraying the absorption circulating fluid on the flue gas in the sulfur dioxide absorption process; and/or Applying the second ammonium salt concentration in the second stage includes spraying the absorption circulating fluid on the flue gas during the sulfur dioxide absorption process; and/or Applying the first ammonium salt concentration in the first stage includes spraying the fine particle washing circulating fluid on the flue gas in the fine particle washing process; and/or Applying the second ammonium salt concentration in the second stage includes spraying the fine particle washing circulating liquid on the flue gas in the fine particle washing process. The method according to item 2 of the patent application scope, wherein the application of the reaction condition gradient includes: Provide the first temperature at the first level; and Provide the second temperature in the second stage; Compared with the flue gas, the first stage is upstream of the second stage. The method according to item 7 of the patent application scope, wherein the first temperature is higher than the second temperature. The method according to item 8 of the patent application scope, wherein providing the first temperature at the first stage includes setting the first temperature during the sulfur dioxide absorption process; and/or Providing the second temperature at the second stage includes setting the second temperature during the fine particle washing process. The method according to item 2 of the patent application scope, wherein the application of the reaction condition gradient includes: Providing the first pH at the first level; and Provide a second pH at the second stage; Compared with the flue gas, the first stage is upstream of the second stage. The method as described in item 10 of the patent application range is characterized in that the first pH is greater than the second pH. The method according to item 11 of the patent application range, characterized in that providing the first pH at the first stage includes spraying the absorption circulating liquid on the flue gas during the sulfur dioxide absorption process; and/or providing the first pH at the first stage This includes spraying fine particle washing circulating liquid on the flue gas during the fine particle washing process. The method as described in item 12 of the patent application range, characterized in that providing the second pH at the second stage includes spraying the absorption circulating liquid on the flue gas during the sulfur dioxide absorption process; and/or providing the second pH at the second stage This includes spraying fine particle washing circulating liquid on the flue gas during the fine particle washing process. The method as described in item 2 of the patent application scope also includes: Cool and purify the flue gas; Absorption of sulfur dioxide after cooling and purification; and After absorption, wash the circulating fluid with fine particles to remove the smoke; Among them: applying a gradient of ammonium salt after purification and cooling; and Both absorption and removal include: Spray ammonium sulfite; and Spray ammonium sulfate. The method according to item 14 of the patent application scope, in which The absorption includes spraying absorption circulation liquid on the flue gas; and The fine particulate washing cycle liquid has: PH below the pH of the absorption circulating fluid; and The concentration of ammonium sulfite is less than that of the absorption circulating fluid. The method as described in item 2 of the patent application scope, wherein, The reaction conditions are temperature gradients defined by an absorption temperature and a washing temperature; and The applied reaction condition gradient includes: Control absorption temperature and washing temperature to reduce energy consumption; Maintain absorption efficiency; Control ammonia slip; and Control aerosol production. The method as described in item 16 of the patent application range is characterized in that the absorption temperature is in the range of 30°C-70°C, or 35°C-60°C, or 45°C-55°C. The method as described in item 16 of the patent application range is characterized in that the washing temperature is in the range of 28°C-68°C, or 30°C-55°C, or 40°C-50°C. The method according to item 14 of the patent application scope, in which The absorption includes: Spray and absorb circulating fluid at the lower level; Relative to the flue gas, spray and absorb the circulating fluid upstream of the lower stage; and The absorption circulating fluid in the first or second stage of the lower and upper stages contains: 0.15%-4.95% ammonium sulfite; and 5%-38% ammonium sulfate; and With a pH value in the range of 4-6.6; The concentration of ammonium sulfite in the upper absorption circulating fluid is lower than that in the lower absorption circulating fluid. The method as described in item 19 of the patent application range is characterized in that the pH of the upper absorption circulation liquid is lower than the pH of the lower absorption circulation liquid. The method according to item 14 of the patent application scope, in which The absorption includes: Spray and absorb circulating fluid at the lower level; Relative to the flue gas, the upper level upstream of the lower level sprays the absorption circulating fluid; and The absorption circulating fluid in the first or two levels of the lower and upper levels includes: 0.15%-4.95% ammonium sulfite; and 5%-38% ammonium sulfate; and With a pH value in the range of 4-6.6; The pH of the upper absorption circulation liquid is lower than that of the lower absorption circulation liquid. The method according to item 14 of the patent application scope, wherein the absorption includes spraying the absorption circulating fluid in a single stage; and/or the absorption includes spraying the absorption circulating fluid in only two stages. The method according to item 14 of the patent application scope, wherein, at a fine particle control level, the fine particle washing circulating liquid comprises: 0.003%-1% ammonium sulfite; and 0.3%-38% ammonium sulfate; and Has a pH in the range of 3-5.4. The method as described in item 23 of the patent application scope, in which The fine particle control includes spraying the fine particle washing circulating liquid in two stages; and At the level of this level, the fine particulate washing cycle liquid contains: 0.1%-1% ammonium sulfite; and 5%-38% ammonium sulfate. A device for controlling aerosol generation in ammonia desulfurization, wherein the device includes: A gas purification and removal system configured to apply an ammonium salt gradient to flue gas; Oxidation system; and auxiliary system. The device of claim 25, wherein the oxidation system includes an oxidation vessel configured for: Forced oxidation of the input ammonium solution to produce multiple outputs of ammonium solutions of different degrees of oxidation; and Provide an output to the gas purification and removal system to define the gradient; and/or The auxiliary system includes: Ammonium sulphate aftertreatment system; Ammonia supply system; and Process water system. The device as described in item 25 of the patent application scope also includes: One tower, the tower A containment gas purification and removal system; and include: A pre-wash area; An absorption zone; and A fine particle control area; Set an element between the absorption zone and the pre-wash zone that only allows gas to pass through; and Multiple spray layers, the pre-washing zone, the absorption zone and the fine particulate matter control zone each include one spray layer of the multiple spray layers; The tower is configured to provide zone control of the solution components to the spray layer. The device as described in item 27 of the patent application range is characterized by an oxidation system: Including the spray layer; and Configured to control the interaction between the liquid sprayed in the different spray layers and the flue gas in the different spray layers to naturally oxidize the liquid to produce multiple ammonium solution outputs with different degrees of oxidation to define the gradient; and/or Where the oxidation system is configured to control the operating temperature gradient of the pre-wash zone; and/or Where the oxidation system is configured to control the operating temperature gradient of the absorption zone; and/or Where the oxidation system is configured to control the operating temperature gradient of the fine particle control zone; and/or Where the oxidation system is configured to control the operating temperature of the pre-wash zone and the operating temperature gradient of the fine particulate matter zone; and/or Where the oxidation system is configured to control the operating temperature gradient of the absorption zone; and/or Where the oxidation system is configured to control the operating temperature gradient of the fine particle area; and/or Where the oxidation system is configured to control the operating temperature gradient of the fine particle area; and/or Where the oxidation system does not include a forced oxidation vessel; and/or The oxidation system is configured to allow the pre-wash solution to enter the absorption zone. The device of claim 27, wherein each zone includes a single spray layer; and/or One zone of this zone includes multiple spray layers; and/or Also contains elements placed between the absorption zone and the fine particle control zone that only allow gas to pass through; and/or Also contains elements placed in the absorption zone that only allow gas to pass through; and/or It also includes elements placed in the fine particle control zone that only allow gas to pass through. The device as described in item 27 of the patent application scope also includes multiple demister layers; among them: One demister layer of the plurality of demister layers is placed in the fine particle control area; and One demister layer of the plurality of demister layers is arranged in each spray layer of the pre-washing zone and the absorption zone. The device according to item 30 of the patent application range, characterized in that the demisters of the multiple demister layers include baffles; and/or The demisters of the multiple demister layers include the roof ridge; and/or The demisters of the multiple demister layers include packing; and/or The demisters of the multiple demister layers include wire mesh; and/or The demisters of the multiple demister layers include structures selected from the following: Baffle Roof filler; Wire mesh; and A combination of one or more of baffles, ridges, fillers and wire mesh. The device as described in item 27 of the patent application range is characterized in that in each spray layer of the absorption zone: the liquid-gas ratio is not less than 0.2 L/Nm ³ ; and the spray coverage is not less than 110%; and in the control of fine particles In each spray layer of the zone: the liquid-gas ratio is not less than 0.1 L/Nm ³ ; and the spray coverage is not less than 105%. The device as described in item 25 of the patent application range is characterized by an oxidation system: Including multiple sections, each section corresponding to different composition of ammonium solution; Configured to form an ammonium salt gradient, To provide components with different compositions to the fine particulate washing circulating fluid; and In order to provide the absorption circulating fluid with different composition components to form an ammonium salt gradient. The device according to item 33 of the patent application, characterized in that each segment is defined by the layer of the oxidation system; and/or Each section is defined by elements of the oxidation system; and/or Each section occupies a different position in the oxidation system; and/or The oxidation system includes 1-5 layers of gas-liquid dispersion intensifiers; and/or The oxidation system: The liquid level is greater than 3m; and The excess of oxidized air is not less than 20%. The device as described in item 27 of the patent application scope is characterized in that a tower is configured to: Cooling and washing flue gas with circulating washing liquid in the pre-washing area, and the concentration of circulating washing liquid increases at the same time; Make the flue gas pass through the absorption zone, where the flue gas is washed and desulfurized by the absorption circulating fluid; Make the flue gas pass through the fine particle control area, and use the fine particle circulating washing liquid to remove the fine particles; Exhaust smoke; Replenish the circulating washing liquid in the pre-washing area from the circulating washing liquid of fine particles; Replenish the absorption circulating fluid to wash the scale deposit on the tower wall; Oxidize and absorb the circulating fluid in the oxidation system; and Circulating fluids with different compositions are drawn from different sections of the oxidation system for distribution to different zones. The device as described in item 35 of the patent application range, characterized in that the fine particle circulating washing liquid is the main component of the circulating washing liquid replenishing liquid; and/or The tower is configured to wash the scale deposits by spraying fine particles to circulate the washing liquid; and/or The tower is configured to wash the scale deposits by spraying process water; and/or Supplement the absorption circulating fluid with the liquid in the fine particulate control area; and/or Supplement the absorption circulating fluid with process water; and/or Replenish the circulating washing liquid of fine particles with process water. The device as described in item 35 of the patent application is characterized in that the tower is configured to provide an empty tower flue gas velocity in the range of 1-5 m/s. Apparatus as described in item 37 of the patent application scope, wherein the tower is configured to provide a temperature in the pre-wash zone in the range of 40°C-80°C; and/or wherein the tower is configured to receive SO ₂ concentrations up to 30,000 mg/Nm ³ Smoke. The device as described in item 38 of the patent application range is characterized in that the tower is also configured Emission of purified flue gas that meets the following requirements: All emission requirements of GB13223-2011; and China Huanfa [2015] No. 164; and Compared with the amino desulfurization and electrostatic defogging listed in PCT/US2002/039095, it has: 10-20% less investment; 5-10% less operating costs; and Cost-effective 15-30%. The device as described in item 39 of the patent application range is characterized in that the SO ₂ concentration of flue gas discharged from the tower is not greater than 200 mg/Nm ³ , or the concentration is not greater than 100 mg/Nm ³ , or the concentration is not greater than 35 mg/Nm ³ , or the concentration is not more than 5 mg/Nm ³ . The device as described in item 39 of the patent application range is characterized in that the total dust concentration of the flue gas aerosol discharged from the tower is not more than 20 mg/Nm ³ or the concentration is not more than 10 mg/Nm ³ or the concentration is not more than 5 mg/Nm ³ , or the concentration is not more than 2 mg/Nm ³ . The device as described in item 39 of the patent application range is characterized in that the ammonia concentration of the flue gas discharged from the tower is not more than 5 mg/Nm ³ or the concentration is not more than 2 mg/Nm ³ or the concentration is not more than 1 mg/Nm ³ , Or the concentration is not greater than 0.5 mg/Nm ³ . The device as described in item 38 of the patent application range is characterized in that the SO ₂ concentration of the flue gas discharged from the tower is not greater than 200 mg/Nm ³ or the concentration is not greater than 100 mg/Nm ³ or the concentration is not greater than 35 mg/Nm ³ , or the concentration is not more than 5 mg/Nm ³ . The device as described in item 38 of the patent application range is characterized in that the total dust concentration of the flue gas aerosol discharged from the tower is not more than 20 mg/Nm ³ or the concentration is not more than 10 mg/Nm ³ or the concentration is not more than 5 mg/Nm ³ , or the concentration is not more than 2 mg/Nm ³ . The device according to item 38 of the patent application scope is characterized in that the ammonia concentration of the flue gas discharged from the tower is not more than 5 mg/Nm ³ , or the concentration is not more than 2 mg/Nm ³ , or the concentration is not more than 1 mg/Nm ³ , Or the concentration is not greater than 0.5 mg/Nm ³ . The device as described in item 35 of the patent application scope also includes a drying device configured to: Receive the absorption fluid; and A solid product including one ion from the circulating liquid is produced. The device as described in item 46 of the patent application range is characterized in that the ion is chloride ion or fluoride ion. The device as described in item 46 of the patent application range is characterized in that the drying equipment is configured to reduce The chloride ion concentration of the circulating fluid is less than 50,000 mg/L; and The fluoride ion concentration in the circulating fluid should be less than 20,000 mg/L. The device as described in item 46 of the patent application range is characterized in that the drying equipment is configured to reduce The chloride ion concentration of the circulating fluid is less than 50,000 mg/L; and The concentration of fluoride ion in the circulating fluid is 300-3000 mg/L. The device as described in item 46 of the patent application range is characterized in that the drying equipment is configured to reduce The concentration of chloride ion in the circulating fluid to 10000-31000 mg/L; and The fluoride ion concentration in the circulating fluid should be less than 20,000 mg/L. The device as described in item 46 of the patent application range is characterized in that the drying equipment is configured to reduce The concentration of chloride ion in the circulating fluid to 10000-31000 mg/L; and The concentration of fluoride ion in the circulating fluid is 300-3000 mg/L. The device as described in item 35 of the patent application range is characterized in that the tower is configured to spray a layer in the absorption zone to absorb the quality ratio of ammonium sulfate to ammonium sulfite in the circulating liquid of 1.5-199:1. The device as described in item 35 of the patent application range is characterized in that the tower is configured to spray a layer in the fine particulate matter absorption area, and the fine particulate matter circulating washing liquid has a quality ratio of ammonium sulfate to ammonium sulfite of 3-1999:1.

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