WO2015161675A1

WO2015161675A1 - Method and equipment for purifying flue gas containing sulfur dioxide

Info

Publication number: WO2015161675A1
Application number: PCT/CN2015/000271
Authority: WO
Inventors: 傅国琳
Original assignee: 林小晓; 车道岚
Priority date: 2014-04-23
Filing date: 2015-04-17
Publication date: 2015-10-29
Also published as: CN103949144B; CN103949144A

Abstract

A method and equipment for purifying a flue gas containing sulfur dioxide. One of the best features of the system is that the problem of sulfur dioxide removal is solved without additional costs. A pretreatment chamber is provided with capability for removing PM10. A solar-powered chamber serves as a sulfur dioxide removal apparatus. A high-intensity ultraviolet lamp and a Fenton reaction allow for reaction with and decomposition of any organic and inorganic molecules. This allows for removal of sulfur dioxide produced in an exhaust gas of coal combustion. The method involves physics and chemistry. Nitric acid is formed when sulfur dioxide is oxidized.

Description

Method and device for purifying flue gas containing sulfur dioxide

(1) Technical field:

The invention relates to a purification method and device, in particular to a method and a device for purifying flue gas containing sulfur dioxide.

(2) Background technology:

In the form of China's sustained and rapid economic development, the demand for energy consumption has risen sharply. In the case of coal alone, the annual increase in demand for coal since the reform and development has been about 8-12%. The biggest problem is the severe air. Pollution.

China today is one of the most polluted countries in the world (after India). Not long ago, at the regular meeting of the State Council of China, the theme of 'eliminating the heart and lungs of the people' was put forward specifically; the pollution control was combined with the people's state and the people's livelihood, and it was determined to eliminate the hat of the polluting country. The Chinese government has decided not only to take off economically but also to make positive contributions to the country, the people, the future generations, and even the world in the environment. On the road built by China, new clean energy sources are limited by reserves and international politics and cannot become the main alternative kinetic energy for domestic industrial demand. Therefore, coal will remain China's main kinetic energy source for a long time. As the industrial demand continues to increase, it means that air pollution will become more serious. Effectively reducing and preventing pollution will always be a arduous task.

As we all know, serious air pollution will bring irreversible disasters to all living things on the earth, and the polluted air is mainly from industrial soot containing a lot of toxic and harmful substances. Most of these harmful soots are produced by the combustion process of coal. However, there is no absolute clean coal in the world, only coal resources with different proportions of toxic substances due to different geological conditions. For example, coal produced in northern China is high-quality low-sulfur coal with a sulfur content of only 1% to 2%; while coal produced in Yunnan, Guizhou and Inner Mongolia can have a sulfur content of more than 5%. According to estimates: the annual emissions of sulfur dioxide in industrial dust in China is as high as 20 million tons. the above. Among the 113 cities with key air pollution control, 40 cities have more sulfur dioxide emissions than the national standard line, and 39 cities are even worse than the national third-level standard line! Acid rain pollution caused by air pollution has already ravaged one-third of China's territory. The faster the industrial process grows, the higher the pollution index will be with its peers, and the environmental control of the relevant departments will become more difficult.

In the past 20 years, China has carried out uninterrupted technical research on soot desulfurization and denitrification. Controlling the pollution of sulfur dioxide by flue gas desulfurization technology is an important part of domestic environmental protection application. It is calculated as low-sulfur coal (1% sulfur): burning one ton of coal produces 16 kg (1600 x 1%, Kg) of sulfur dioxide. A medium-sized coal-fired boiler burns about 150 to 200 tons of coal per day; that is, it produces 2.4 to 3.2 tons of sulfur dioxide per day. The current desulfurization technologies include coal mixed lime or additives; direct calcium injection in the furnace and dry bed limestone desulfurization; and wet desulfurization such as calcium alkali method, ammonia alkali method, sodium alkali method, and magnesium alkali method. After years of practice verification and the elimination of market economy technology, only a small number of technical equipment has truly entered the coal-fired industry boiler application. The shortcoming of the prior art is that the desulfurization efficiency is only 60-80% on average, and the cost is extremely high. The current operating cost of desulfurization is 0.3 yuan per watt, and the annual operating cost of a medium-sized 12 megawatt coal-fired power plant is 44.3 million yuan; and the cost of its desulfurization unit is 360 million yuan!

(3) Invention content:

It is an object of the present invention to provide a method and apparatus for purifying flue gas containing sulfur dioxide. One of the best functions of the system is to solve the problem of sulfur dioxide removal without any additional cost. The pretreatment chamber has the ability to eliminate PM10, which is a sulfur dioxide removal device. The high intensity UV lamp and Fenton reaction can react with any organic and inorganic molecules and decompose. The invention can eliminate the sulfur dioxide generated in the coal-fired exhaust gas, and is a physical compounding chemical method, and the sulfur dioxide is oxidized to form sulfuric acid.

The technical solution of the invention:

A method of treating flue gas containing sulfur dioxide, comprising the steps of:

(1) adding water to the pretreatment vessel;

(2) adding a solution containing a Fenton reagent and adjusting the pH to 3 or less using an α-hydroxy acid, the metal containing a photo-assisted Fenton reaction and hydrogen peroxide;

The solution is configured to have a mass percentage of hydrogen peroxide to water of 3% to 5%.

The molar ratio of hydrogen peroxide to metal system is greater than or equal to 10:1;

(3) arranging an illumination system in the reaction vessel according to the light absorption peak of the metal system;

(4) passing the exhaust gas into the pretreatment vessel and sufficiently contacting the liquid to leave solid particles having a diameter larger than 10 μm in the liquid;

(5) discharging a liquid containing solid particles having a diameter greater than 10 μm to a pretreatment vessel;

(6) discharging the purified flue gas out of the pretreatment container;

(7) passing the flue gas discharged from the step (6) into the reaction vessel, and sufficiently contacting the Fenton reagent to oxidize the sulfur dioxide in the flue gas to sulfur trioxide and dissolve the solution into sulfuric acid;

(8) Deriving the sulfuric acid solution after the reaction, and periodically monitoring the concentration of the Fenton reagent in the derivatized solution, and adding a new solution containing Fenton's reagent to keep the composition of the solution stable according to the monitored condition;

(9) The purified gas is discharged from the reaction vessel.

After the above step (1), the step (1') is added to adjust the pH to 3 or less with nitric acid, and then an oxidizing agent is added to oxidize the carbon particles to carbon monoxide, and some of the SO _{2 is} oxidized to SO ₃ ; the oxidizing agent is hydrogen peroxide. a mixture of molybdenum oxide and tungsten oxide, a mixture of magnesium oxide and magnesium hydroxide or ferric oxide, wherein the solid particles of molybdenum oxide, tungsten oxide, magnesium oxide, magnesium hydroxide and ferric oxide have a diameter of less than 20 nm. The volume ratio of hydrogen peroxide to water is 1:18-22, the molar ratio of molybdenum oxide to tungsten oxide is 1:1, the molar ratio of magnesium oxide to magnesium hydroxide is 1:1, and the ratio of molybdenum oxide to water is greater than or equal to 10mol/L, the ratio of tungsten oxide to water is 10mol/L or more, the ratio of magnesium oxide to water is 10mol/L or more, and the ratio of magnesium hydroxide to water is 10mol/L or more, ferric oxide and water. The dosage ratio is 20 mol/L or more.

The concentration of the oxidizing agent in the above step (1') needs to be monitored periodically and the oxidizing agent is supplemented as needed to stabilize the concentration of the oxidizing agent in the solution.

The metal system in the above step (2) is a Fe(II)/F(III) system or a Cu(I)/Cu(II) system; when the metal system is a Fe(II)/F(III) system, The illumination is ultraviolet light having a wavelength of 200 nm to 400 nm; when the metal system is a Cu(I)/Cu(II) system, the illumination is visible light having a wavelength of 600 nm to 800 nm.

The Fe(II)/F(III) system described above consists of FeSO ₄ and Fe ₃ O ₄ particles having a diameter of less than 20 nm.

The Cu(I)/Cu(II) system described above consists of Cu ₂ O and CuSO ₄ particles having a diameter of less than 20 nm.

The manner of sufficient contact in the above step (4) is to spray the liquid through the spray device to the gas to increase the area and time of contact of the exhaust gas with the liquid.

The flue gas in the above step (4) enters from the lower portion of the pretreatment vessel, is oriented horizontally and at an angle of 40 to 50 degrees with the vessel wall to increase the time of contact with the liquid.

In the above step (5), the liquid from which the pretreatment vessel is derived is removed from the pretreatment vessel by a water pump after removing the particulate matter larger than 10 μm.

The hydrogen peroxide described above is produced by reacting magnesium peroxide, sodium peroxide or calcium peroxide having a diameter of less than 50 nm in the solution.

The above-mentioned consumption of hydrogen peroxide was closely monitored by periodically collecting samples, and the consumption rate of peroxide was observed using an iodine/potassium permanganate (I/KMnO4) titration method.

The above α-hydroxy acid is glycolic acid, pyruvic acid or lactic acid.

The manner of sufficient contact in the above step (7) is at least one of directly introducing a gas into the liquid or spraying the liquid through the shower device to the gas.

The above step (8) is added to the step 8' to adsorb and recover the metal system substance by using a commercially available DOW Chemical Company's Amberlite IRC 748 ion exchange resin coating to purify the sulfuric acid-containing solution.

A desulfurization device for realizing the above method, comprising a pretreatment bin and a light energy bin; the pretreatment bin comprises a pretreatment bin body 1-13, a pretreatment bin sprinkler device 1-2, a pretreatment bin air inlet 1 -4, pretreatment bin pump 1-6, accumulator 1-7, pretreatment bin outlet port 1-8, pretreatment bin inlet port 1-10 and pretreatment bin outlet port 1-12, The bottom of the pretreatment cartridge body 1-13 is the accumulator 1-7, and the pretreatment chamber outlet port 1-8 is disposed at the accumulator 1-7, the pretreatment chamber inlet 1-4, pretreatment The tank inlet port 1-10 and the pretreatment tank outlet port 1-12 are disposed on the pretreatment tank body 1-13 above the accumulator 1-7, and the pretreatment tank outlet port 1-12 is at the pretreatment tank inlet port. Above the 1-4, the pretreatment chamber spraying device 1-2 is disposed in the pretreatment bin body 1-13, and the pretreatment bin pump 1-6 is connected to the output end of the accumulator 1-7 through a pipe. And an input end of the pretreatment chamber sprinkler device 1-2; the light energy bin includes a light energy bin body 2-11, a light energy bin air inlet 2-2, a light energy bin air outlet 2-1, a light energy bin Inlet port 2-3, gas-liquid mixing channel 2-4, light energy bin pump 2-5, light energy bin outlet 2-6, light energy bin spray The device 2-8 and the illumination device 2-10, the light energy bin inlet 2-2 and the light energy bin outlet 2-1 are disposed at an upper portion of the light energy cartridge body 2-11, and the light energy bin inlet 2-3 is disposed in the middle of the light energy storage body 2-11, and the light energy storage port 2-6 is disposed at the bottom of the light energy storage body 2-11, the gas-liquid mixing channel 2-4, the light energy The bin shower device 2-8 and the illumination device 2-10 are located in the light energy bin body 2-11, and the input end of the gas-liquid mixing channel 2-4 is connected to the light energy bin air inlet 2-2, and the gas-liquid mixing channel 2-2 The output end of 4 is located at a position close to the bottom of the light energy bin body 2-11, and the light energy bin pump 2-5 is connected by a pipe to the output end of the bottom of the light energy bin body 2-11 and the light energy bin shower device 2 The input end of -8; the pre-chamber outlet port 1-12 is connected to the light energy box inlet 2-2.

The pretreatment bin body 1-13 is provided with a pretreatment bin inspection cover 1-1 at the top, and the pretreatment bin body 1-13 is provided with a pretreatment bin inspection door 1-11 on the side wall of the pretreatment cartridge body 1-13, and the top of the reservoir 1-7 is set. The funnel-shaped collecting plates 1-3, the side walls of the accumulators 1-7 are provided with pre-treatment tank levelers 1-9 and sampling ports 1-5.

The pretreatment chamber spraying device 1-2 is a pressure shower device disposed at the top of the pretreatment cartridge body 1-13, or a pressure shower device disposed at the top of the pretreatment cartridge body 1-13. And a spray sprinkler disposed on the inner wall of the pretreatment cartridge body 1-13.

The spray droplets of the above-mentioned pressure sprinkler device are uniform wires; the diameter of each drop is 2 to 3 mm, and the interval between each drop is 6 to 10 mm.

The pretreatment cartridge body 1-13 described above is made of a stainless steel metal plate.

The pretreatment bin pump 1-6 described above is an acid-resistant water pump.

The above-mentioned light energy storage body 2-11 is made of a stainless steel metal plate, and the inner wall of the light energy storage body 2-11 is coated with an anti-corrosion coating.

The light energy chamber liquid level device 2-7 is disposed on the side wall of the light energy storage body 2-11, and the light energy storage box inspection cover 2-9 is disposed at the top of the light energy storage body 2-11.

The illumination device 2-10 described above is a quartz tube ultraviolet lamp or a visible light lamp.

The lower half of the above-mentioned light energy storage chamber has a purification plate coated with a commercially available coating of Amberlite IRC 748 ion exchange resin of DOW Chemical Co., Ltd. for adsorbing and recovering the metal system substance and purifying the solution containing sulfuric acid.

The working principle of the invention:

1, the working principle of the pre-processing warehouse:

The liquid in the pretreatment chamber is controlled by an acid-resistant water pump containing water and oxidizing reagents. The water removes PM10 from the flue gas. When hydrogen peroxide (H ₂ O ₂ ) is used as the oxidizing reagent, H ₂ O ₂ is equivalent to a strong oxidizing agent in an acidic reaction environment. The velocity of the flue gas in the ventilation duct exceeds 6 m/s. At this rate, any material carried by the flue gas does not have much time to generate a chemical reaction unless the reaction is exothermic and spontaneous. In addition, hydrogen peroxide is relatively inexpensive and safe compared to other strong oxidants, so that when the technology is applied to the industry on a large scale, the cost can be greatly reduced and the safety factor can be improved.

European and American countries have tried to use hydrogen peroxide to purify flue gas but have not achieved significant results, probably because the peroxide tested is in a gaseous state. Although the gas reaction has a high reaction kinetics and usually occurs very quickly, the reverse reaction can be immediately produced after reaching equilibrium. Since the oxides produced by peroxides are all in a transition state, they are not very stable. If there is no effective way to convert the transition state to other final products, the intermediate can be immediately converted back to the reactants thereby reducing the effectiveness of the oxidant. Therefore, the problem is solved successfully and effectively by placing the light energy chamber immediately behind the pretreatment chamber.

A sprinkler system is placed on the top and sides of the pretreatment chamber to ensure adequate long-term contact between the flue gas and the liquid. The flue gas will enter the pretreatment chamber at an angle of 40-50 degrees, causing the flue gas to produce a spiral effect when moving upward. Both the sprinkler system and the spiral effect increase the time that the flue gas stays inside the pretreatment chamber. The even droplets of the shower at the top of the shower ensure maximum contact between the flue gas and the liquid without any back pressure on the exhaust system. Any droplets smaller than 2 mm can be easily carried into the light bin by the exhaust force. Cross-contamination reduces the efficiency of the equipment and therefore needs to be avoided. The side shower system is sprayed to ensure adequate mixing of liquids and gases.

2, the working principle of the light energy warehouse:

In a light energy chamber, sulfur dioxide is converted to sulfur trioxide by using a photo-assisted Fenton reaction and a catalytic/oxidation reaction. The Fenton reaction is a simple photoinduced oxidation/reduction catalytic reaction. The main feature of the Fenton reaction is its production of reactive oxygen species (ROS), especially hydroxyl radicals. Hydroxyl radicals are the most effective reactive oxygen species, which oxidize any organic (including biomolecules) and inorganic matrices around them. The original chemical reaction is the reaction of Fe(II) with H ₂ O ₂ to form Fe(III) and OH· (see Figure 4). The reduction of Fe(III) to Fe(II) requires heat or light energy. There are three main mechanisms in the absence of matrix and substrate as well as light energy (see Figures 5-7). Fenton reaction efficiency of light depends on the concentration of H ₂ O _{_2, Fe (II) / H 2} O 2 ratio, pH, reaction time and intensity of UV (ultraviolet) light. The chemical, physical, initial, and temperature concentrations of the contaminants also have an important impact on the final efficiency.

The smoke in the smoke (the main component of the smog) is actually the coal that is not completely burned. The organic matter contained in the coal is decomposed by heat to produce a flammable gas, also known as "volatile matter" (VOC). A mixed gas of various compounds such as hydrocarbons, hydrogen, and carbon monoxide. When coal combustion conditions are not smashed or when high-volatility coal (poor coal) burns, it is easy to produce carbon particles that are not burnt out, commonly known as "black smoke"; and produce more VOCs such as carbon monoxide and polycyclic aromatic hydrocarbons. Hydrocarbon contaminants such as aldehydes.

Any organic carbon-containing molecules present in the flue gas are oxidized to CO ₂ as they pass through the light energy bin, and heavy metals and inorganic minerals are deposited in the fiber mercury removal filter in our exhaust duct. The first reaction of hydroxyl radicals with hydrocarbons in flue gas in a light energy chamber is to remove one hydrogen atom from its molecular structure (R) and then form water and alkyl radicals (R·) (see Figure 8). The second reaction is that the alkyl radical (R·) reacts rapidly with the molecular oxygen to form a peroxy radical (see Figure 9), after which many steps are taken to eventually produce carbon dioxide and water.

Sulfur dioxide is oxidized to sulfur trioxide and forms sulfuric acid when it enters the light energy bin. The reaction mechanism is shown in Figure 11 (Figure 11).

The advantages of the invention: 1. The advantage of the nano material is that the surface area is large, and the mutual transfer of the electron layers between the molecules is very rapid, and the chemical reaction rate can be exponentially accelerated; especially in the field of optics, the diameter of the nanometer is smaller. The greater the activity and momentum of energy. Therefore, in order to make any chemical reaction of the flue gas with such a fast flow rate, the advantages of nanotechnology are undeniable. The self-oxidation-reduction reaction is spontaneous and has the characteristics of a catalyst, so it is not necessary to add it frequently, and the amount is small, which is very economical. 2. The present invention is based on the principle of photo-assisted Fenton reaction and has achieved great success in eliminating soot. The present invention is the most economical and effective method of particulate removal today, which is a more economical and efficient way to control air pollution without any additional manufacturing and operating costs. It can be incorporated into existing dust removal systems for coal-fired boilers to increase their effectiveness and completely replace the old ones. This filtration system can also be used in other industrial markets, including cement plants, steel plants, municipal waste combustion plants, medical waste combustion plants, chlorine gas plants, pulp and paper production plants.

1. Testing standards (methods) and using instruments

2, sulfur removal effect test results Unit: mg / cubic meter

(4) Description of the drawings:

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view showing the structure of a pretreatment chamber having two types of shower devices in an apparatus for treating flue gas containing sulfur dioxide.

2 is a schematic view showing the structure of a pretreatment chamber having a top pressure spray device in a device for treating flue gas containing sulfur dioxide according to the present invention.

3 is a schematic view showing the structure of a light energy chamber in a device for treating flue gas containing sulfur dioxide according to the present invention.

4 is a reaction equation for the oxidation of Fe(II) to Fe(III) in a photo-assisted Fenton reaction in a method for treating flue gas containing sulfur dioxide according to the present invention.

Figure 5 is a reaction equation for the reduction of the first Fe(III) to Fe(II) in the photo-assisted Fenton reaction in a method for treating flue gas containing sulfur dioxide according to the present invention.

6 is a reaction equation for reducing a second Fe(III) to Fe(II) in a photo-assisted Fenton reaction in a method for treating flue gas containing sulfur dioxide according to the present invention.

Figure 7 is a reaction equation for the reduction of a third Fe(III) to Fe(II) in a photo-assisted Fenton reaction in a method for treating flue gas containing sulfur dioxide according to the present invention.

8 is a chemical reaction formula for reacting hydroxyl radicals with hydrocarbons to form water and alkyl radicals in a photo-assisted Fenton reaction in a method for treating flue gas containing sulfur dioxide according to the present invention;

Figure 9 is a chemical reaction formula for reacting alkyl radicals with molecular oxygen to form peroxy radicals in a photo-assisted Fenton reaction in a method for treating flue gas containing sulfur dioxide according to the present invention.

Figure 10 is a chemical reaction formula for the decomposition of C ₂ H ₆ into carbon dioxide and water in a process for treating flue gas containing sulfur dioxide according to the present invention.

Figure 11 is a chemical reaction formula for treating sulfur dioxide containing sulfur dioxide in a process for treating sulfur dioxide containing sulfur dioxide to form sulfur trioxide and form sulfuric acid.

Figure 12 shows the recycling structure of the lower part of the light energy bin

Among them, 1-1 is the pre-treatment warehouse inspection cover, 1-2 is the pre-treatment tank sprinkler, 1-3 is the funnel-shaped collecting plate, 1-4 is the pre-treatment tank inlet, 1-5 is the sampling port, 1-6 is the pre-treatment tank pump, 1-7 is the accumulator, 1-8 is the pre-treatment tank outlet, 1-9 is the pre-treatment tank level, and 1-10 is the pre-treatment tank inlet 1-11 is the pre-treatment warehouse inspection door, 1-12 is the pre-treatment tank outlet port, 1-13 is the pre-treatment tank body, 2-1 is the light energy bin outlet, and 2-2 is the light energy bin air inlet. 2-3 is the light energy inlet, 2-4 is the gas-liquid mixing channel, 2-5 is the light energy storage pump, 2-6 is the light energy storage port, 2-7 is the light energy storage liquid Positioner, 2-8 is the light energy tank shower device, 2-9 is the light energy warehouse inspection cover, 2-10 lighting equipment, 2-11 is the light energy warehouse body. Figure 12 The main room of the 1 warehouse is 2, the lower purification chamber 3, the purification plate 4, the liquid flow control plug 5, the liquid outlet, the 6 outlet, the air inlet, the inlet

(5) Specific implementation methods:

Embodiment 1: A method of treating flue gas containing sulfur dioxide, characterized by comprising the steps of:

(1) adding water to the pretreatment vessel;

The solution is configured to have a mass percentage of hydrogen peroxide to water of 5%.

The molar ratio of hydrogen peroxide to metal system is about 30:1;

(6) discharging the purified flue gas out of the pretreatment container;

(7) passing the flue gas discharged from the step (6) into the reaction vessel, and sufficiently reacting with the Fenton reagent to oxidize the sulfur dioxide in the flue gas to sulfur trioxide;

(8) Deriving the solution after the reaction, and regularly monitoring the concentration of the Fenton reagent in the derivatized solution, and adding a new solution containing Fenton's reagent to stabilize the solution component according to the monitored condition;

(9) Recovery of sulfuric acid in the solution after the reaction

(10) The purified gas is discharged from the reaction vessel.

After the step (1) described above, the step (1') is added to adjust the pH to 3 or less with nitric acid, and then an oxidizing agent is added to oxidize the carbon particles to carbon monoxide, and the oxidizing agent is hydrogen peroxide, hydrogen peroxide and water. The mass percentage is 5%

The concentration of the oxidizing agent in the above step (1') needs to be monitored every 10 hours and the oxidizing agent is supplemented as needed to stabilize the concentration of the oxidizing agent in the solution.

The metal system in the above step (2) is a Fe(II)/F(III) system; when the metal system is a Fe(II)/F(III) system, the illumination is ultraviolet light having a wavelength of 200 nm to 400 nm. .

The flue gas in step (4) described above enters from the lower portion of the pretreatment vessel and is oriented horizontally at an angle of 45 degrees to the vessel wall to increase the time of contact with the liquid.

The above-mentioned consumption of hydrogen peroxide was closely monitored by collecting samples every 10 hours, and the consumption rate of peroxide was observed using an iodine/potassium permanganate (I/KMnO4) titration method.

The above α-hydroxy acid is lactic acid.

The manner of sufficient contact in the above step (7) is to directly pass the gas into the liquid and spray the liquid through the spraying device to the gas.

The metal system substance is adsorbed and recovered by using Amberlite IRC 748 ion exchange resin coating of commercially available DOW chemical company, and the solution containing sulfuric acid is purified.

The pretreatment chamber sprinkler device 1-2 described above is a pressure sprinkler device disposed at the top of the pretreatment cartridge body 1-13 and a spray sprinkler device disposed on the inner wall of the pretreatment cartridge body 1-13. (see picture 1)

The spray droplets of the above-mentioned pressurized shower device are uniform wires; each droplet has a diameter of 2 to 3 mm, and each droplet is spaced apart by 8 mm.

The pretreatment bin pump 1-6 described above is an acid-resistant water pump.

The above-mentioned light energy storage body 2-11 is made of a stainless steel metal plate, and the inner wall of the light energy storage body 2-11 is coated with a 2-3 mm Teflon anticorrosive coating.

The illumination device 2-10 described above is a quartz tube ultraviolet lamp.

The lower part of the desulfurization chamber has a purification plate (Fig. 12) coated with a commercially available coating of Amberlite IRC 748 ion exchange resin of DOW Chemical Co., Ltd. for adsorption recovery of the metal system substance and purification of the solution containing sulfuric acid.

The working method of the sulfur removal device in this embodiment:

Take a 15 ton coal-fired boiler that burns about 30 tons of coal per day as an example:

Working method of pretreatment bin:

(1) The diameter and height of the pretreated cartridge body 1-13 are 2.7 meters and 3 meters, respectively;

(2) Injecting water at a water level of 40 cm to form 2289 liters of water, using nitric acid to adjust the pH to below 3, and then adding 327 liters of 35% hydrogen peroxide;

(3) The pretreatment bin pump 1-6 is opened, and the pretreatment bin sprinkler device 1-2 starts to work;

(4) The flue gas enters the pre-treatment chamber body 1-13 from the direction of the pre-chamber air inlet 1-4 and the inner wall of the pre-treatment chamber body 1-13 at an angle of forty-five degrees, so that the flue gas is generated when moving upward. Spiral effect

(5) solid particles having a diameter greater than 10 microns in the flue gas remain in the liquid;

(6) discharging a liquid containing solid particles having a diameter greater than 10 μm from the pretreatment tank outlets 1-8;

(7) discharging the purified flue gas from the pre-chamber outlet port 1-12;

(8) The consumption of hydrogen peroxide (H ₂ O ₂ ) was closely monitored by sample collection every 10 hours, and the consumption rate of peroxide was observed using iodine/potassium permanganate (I/KMnO ₄ ) titration. .

Working method of light energy warehouse:

(1) The diameter and height of the light energy bins 2-11 are 2.7 meters and 2.25 meters, respectively;

(2) injecting 5725 liters of water into the light energy storage body 2-11, adding 817 liters of 35% H ₂ O ₂ and 64 kg of FeSO ₄ (FeSO ₄ :H ₂ O ₂ = ₁ : ₅ w/w);

(3) Four UV light having a width of 1000 W, a wavelength of 200 nm to 400 nm, and a light absorption peak equal to 365 nm (FeSO ₄ having the highest absorption coefficient at 365 nm) are disposed in the light energy storage body 2-11;

(4) opening the light energy bin shower device 2-8;

(5) The flue gas discharged from the outlet port 1-12 of the pretreatment chamber is introduced into the light energy bin body 2-11 from the light source bin inlet 2-2, and is in contact with the liquid at the gas-liquid mixing channel 2-4. After the gas floats out of the liquid surface, it reacts with the droplets ejected from the light energy tank spraying device 2-8 to decompose the hydrocarbons in the flue gas into carbon dioxide and water, and the carbon particles and carbon monoxide are oxidized into carbon dioxide, while sulfur dioxide Oxidizing to sulfur trioxide and dissolving in solution to form sulfuric acid, wherein hydrocarbons commonly found in flue gas, including C ₂ H _{6 ,} can be decomposed in the light energy bin (see Figure 10);

(6) The solution after the reaction is taken out from the outlet 2-6 of the light energy storage chamber. The consumption of hydrogen peroxide (H ₂ O ₂ ) is closely monitored by sample collection every 10 hours, and iodine/permanganic acid is used. Potassium (I / KMnO ₄ ) titration method to observe the consumption rate of peroxide, according to the CO ₂ content in the flue gas, the metering pump will replenish hydrogen peroxide from the reservoir to the light energy bin 2-11;

(7) Recovery of sulfuric acid in the solution after the reaction

(8) The purified gas is discharged from the light energy storage port 2-1 to the light energy storage body 2-11.

According to the industrial test data of the 15 ton coal-fired boiler according to the present embodiment, the method of the present invention has achieved a SO ₂ removal rate of from 99.68% or more (from 314 μg/m 3 to 1 μg/m 3 ).

Detection method and device

The test results are as follows

Example 2:

(1) adding water to the pretreatment vessel;

The solution is configured to have a ratio of hydrogen peroxide to water of 4%.

The molar ratio of hydrogen peroxide to metal system is 10:1;

(6) discharging the purified flue gas out of the pretreatment container;

(7) passing the flue gas discharged from the step (6) into the reaction vessel, and sufficiently reacting with the Fenton reagent to oxidize the sulfur dioxide in the flue gas to sulfur trioxide, and the sulfur trioxide is dissolved in water to form sulfuric acid;

(9) Recovery of sulfuric acid in the solution after the reaction

(10) The purified gas is discharged from the reaction vessel.

After the step (1) described above, the step (1') is added to adjust the pH to 3 or less with nitric acid, and then an oxidizing agent is added to oxidize the carbon particles to carbon monoxide. The oxidizing agent is a mixture of molybdenum oxide and tungsten oxide, and is oxidized. The solid particles of molybdenum and tungsten oxide have a diameter of less than 20 nm, a molar ratio of molybdenum oxide to tungsten oxide of 1:1, and a mixture concentration of molybdenum oxide and tungsten oxide of ≥10 mol/L.

The metal system in the above step (2) is a Cu(I)/Cu(II) system, and the light is visible light having a wavelength of 600 nm to 800 nm.

The hydrogen peroxide described above is produced after the reaction in the solution of magnesium peroxide having a diameter of less than 50 nm.

The above-mentioned consumption of hydrogen peroxide was closely monitored by collecting samples every 8 hours, and the consumption rate of peroxide was observed using an iodine/potassium permanganate (I/KMnO4) titration method.

The above α-hydroxy acid is glycolic acid.

A sulfur removal device for realizing the above method, comprising a pretreatment bin and a light energy bin; the pretreatment bin comprises a pretreatment bin body 1-13, a pretreatment bin sprinkler device 1-2, a pretreatment bin air inlet 1-4, pre-treatment tank pump 1-6, reservoir 1-7, pre-treatment tank outlet port 1-8, pre-treatment tank inlet port 1-10 and pre-treatment tank outlet port 1-12, The bottom of the pretreatment cartridge body 1-13 is the accumulator 1-7, and the pretreatment bin outlet port 1-8 is disposed at the accumulator 1-7, the pretreatment bin inlet 1-4, pre The treatment tank inlet port 1-10 and the pretreatment tank outlet port 1-12 are disposed on the pretreatment tank body 1-13 above the accumulator 1-7, and the pretreatment tank outlet port 1-12 is in the pretreatment tank inlet. Above the port 1-4, the pretreatment chamber spray device 1-2 is disposed in the pretreatment bin body 1-13, and the pretreatment bin pump 1-6 is connected to the output of the accumulator 1-7 through a pipe. The input end of the end and pretreatment chamber sprinkler device 1-2; the light energy bin includes a light energy bin body 2-11, a light energy bin air inlet 2-2, a light energy bin air outlet 2-1, and a light energy Warehouse inlet 2-3, gas-liquid mixing channel 2-4, light energy bin pump 2-5, light energy bin outlet 2-6, light energy bin spray The device 2-8 and the illumination device 2-10, the light energy bin inlet 2-2 and the light energy bin outlet 2-1 are disposed at an upper portion of the light energy cartridge body 2-11, and the light energy bin inlet 2-3 is disposed in the middle of the light energy storage body 2-11, and the light energy storage port 2-6 is disposed at the bottom of the light energy storage body 2-11, the gas-liquid mixing channel 2-4, the light energy The bin shower device 2-8 and the illumination device 2-10 are located in the light energy bin body 2-11, and the input end of the gas-liquid mixing channel 2-4 is connected to the light energy bin air inlet 2-2, and the gas-liquid mixing channel 2-2 The output end of 4 is located at a position close to the bottom of the light energy bin body 2-11, and the light energy bin pump 2-5 is connected by a pipe to the output end of the bottom of the light energy bin body 2-11 and the light energy bin shower device 2 The input end of -8; the pre-chamber outlet port 1-12 is connected to the light energy box inlet 2-2.

The pretreatment chamber shower device 1-2 described above is a pressure shower device disposed at the top of the pretreatment cartridge body 1-13. (See Figure 2)

The pretreatment bin pump 1-6 described above is an acid-resistant water pump.

The illumination device 2-10 described above is a visible light lamp.

In the present embodiment, one of the advantages of using the Cu(I)/Cu(II) system is that the light absorption peak of Cu ₂ O is 600 nm, and the light absorption peak of CuSO ₄ is 700 nm, which is in the visible light region which is very harmful. (600-800nm, near-infrared).

Claims

A method for purifying flue gas containing sulfur dioxide, comprising: the following steps

(1) The industrial waste gas containing sulfur dioxide is pretreated, and the pretreatment process removes solid particles having a diameter larger than 10 μm in the exhaust gas.

(2) adding a solution containing a Fenton's reagent and an alpha hydroxy acid having a pH of 3 or less to a Fenton reaction vessel, the Fenton reagent comprising a metal system capable of undergoing photo-assisted Fenton reaction and hydrogen peroxide

The solution is configured with a hydrogen peroxide concentration of 3% to 5% by volume; the ratio of hydrogen peroxide to the metal system is a molar ratio ≥10

(3) Setting the illumination system according to the light absorption peak of the metal system

(4) The gas is passed into the Fenton reaction vessel, and the reaction is fully contacted with the Fenton reagent to oxidize the sulfur dioxide to sulfur trioxide and dissolve in the solution to form sulfuric acid.

(5) Deriving the solution after the reaction, and regularly monitoring the concentration of the Fenton reagent in the derivatized solution. According to the monitoring situation, adding a new solution containing Fenton reagent to stabilize the solution composition in the container.

(6) Purified gas discharge container
The method of claim 1 wherein:

The metal system in step (2) is Fe(II)/F(III) system or Cu(I)/Cu(II) system; when the metal system is Fe(II)/F(III) system, the illumination is Ultraviolet light having a wavelength of 200 nm to 400 nm; when the metal system is a Cu(I)/Cu(II) system, the light is visible light having a wavelength of 600 nm to 800 nm.
The method of claim 2 wherein Fe(II)/F(III) The system is a triiron tetroxide particle of less than 20 nanometers.
The method of claim 1 wherein:

The hydrogen peroxide in the step (2) is produced by reacting magnesium peroxide or sodium peroxide or calcium peroxide in the solution.
The method of claim 1 wherein the manner of sufficient contact in step (4) is

Method 1: Gas directly into the liquid

Method 2, adding a shower device to the container

Optionally, one or both of these two methods are used simultaneously.
The method according to claim 1, wherein the step (4) is followed by the step (4') of adsorbing and recovering the metal system substance by using a commercially available Amberlite IRC 748 ion exchange resin coating of DOW Chemical Co., Ltd., which will contain Solution purification of sulfuric acid
The method of claim 1 wherein the step of pretreating comprises

a adding water to the pretreatment vessel;

b passing the exhaust gas into the pretreatment vessel, in full contact with the liquid, leaving solid particles having a diameter greater than 10 nm in the solution;

cExtract the solution containing solid particles from the pretreatment container

d The purified exhaust gas exits the pretreatment vessel and enters the Fenton reaction vessel.
The method of claim 7 wherein:

Join after step a

Step a' is to add an oxidizing agent to the water, and the oxidizing agent may be selected from hydrogen peroxide, or Manganese oxide, or a mixture of molybdenum oxide and tungsten oxide, or ferric oxide, or a mixture of magnesium oxide and magnesium hydroxide, wherein the solid particles should be nanomaterials having a diameter of less than 20 nm
The method according to claim 1, wherein the concentration of the oxidizing agent is regularly monitored by the liquid outlet, and the oxidizing agent is supplemented as needed to stabilize the concentration of the oxidizing agent in the solution.
The method of claim 7 wherein:

The liquid in step b is sprayed through the spray device to increase the area and time of contact of the exhaust gas with the liquid
The method of claim 7 wherein:

In step b, the exhaust gas enters the pretreatment vessel and enters from the lower portion of the vessel. The direction is horizontal and at an angle of 40 to 50 degrees to the wall of the container to increase the time of contact with the liquid
The method of claim 7 wherein:

The liquid flowing out of the pretreatment chamber is returned to the pretreatment vessel by the water pump after removing the particles larger than 10 microns.
A desulfurization apparatus for implementing the method of claim 1, comprising:

Warehouse body (2-11), access cover (2-9), air inlet (2-2), gas-liquid mixing channel (2-4), liquid inlet (2-3), lighting equipment (2-10) ), the liquid outlet (2-6), the air outlet (2-1), the air inlet is connected with the gas-liquid mixing channel, the gas-liquid mixing channel is located at the lower part of the warehouse near the bottom of the warehouse, and the air outlet is located at the upper part of the warehouse. The top position also includes a pre-treatment bin;
The desulfurization apparatus according to claim 13, wherein the pretreatment chamber is in the form of a vertical barrel, and the structure of the pretreatment chamber comprises:

Carcass body (1-13), liquid sprinkler (1-2), air inlet (1-4), sampling port (1-5), Water pump (1-6) for controlling the circulation of liquid in the chamber, reservoir (1-7), outlet (1-8), level (1-9), inlet (1- 10), the inspection door (1-11), the air outlet (1-12) air outlet is connected with the air inlet of the desulfurization device, and the liquid storage device is connected through the pipeline and the water pump and the liquid spray device;
A desulfurization apparatus according to claim 13, wherein the solution of the pretreatment chamber contains an oxidizing agent, and the oxidizing agent may be selected from hydrogen peroxide or manganese oxide, or a mixture of molybdenum oxide and tungsten oxide, or ferric oxide. Or a mixture of magnesium oxide and magnesium hydroxide, wherein the solid particles should be nanomaterials having a diameter of less than 20 nm
A desulfurization apparatus according to claim 13, wherein the lower portion of the desulfurization chamber has a purification plate coated with an Amberlite IRC 748 ion exchange resin coating for adsorbing and recovering the metal system substance, and containing sulfuric acid. Solution purification.
A desulfurization apparatus according to claim 13, wherein the hydrogen peroxide used in the solution added to the desulfurization means is produced by reacting magnesium peroxide or sodium peroxide or calcium peroxide in said solution.
The desulfurization apparatus according to claim 13, wherein the metal system in the solution of the desulfurization chamber is a Fe(II)/Fe(III) system or a Cu(I)/Cu(II) system; and when the metal system is Fe ( II) / Fe (III) system, the corresponding illumination device is an ultraviolet lamp, the emission wavelength is 200nm to 400nm, the peak value is 365nm; when the metal system is Cu (I) / Cu (II) system, the corresponding illumination device is visible light The tube has an emission wavelength of 600 nm to 800 nm.
A desulfurization apparatus according to claim 18, wherein the Fe(II)/Fe(III) system is a triiron tetroxide particle having a diameter of less than 20 nm.
A desulfurization apparatus according to claim 13, wherein the consumption of hydrogen peroxide is closely monitored by hourly sample collection, and iodine/potassium permanganate is used. (I/KMnO4) titration method was used to observe the consumption rate of peroxide.