A system and method for coordinated desulfurization and denitrification by electron beam and oxygen

Abstract

The present invention relates to a system and method for electron beam and oxygen coordinated desulfurization and denitrification, the system comprising a dust removal device, a spray device, a mixed reaction device, an absorption device, an oxygen supply device and an ammonia supply device; the mixed reaction device comprises at least two gas distribution tube plates sequentially arranged inside a shell along the flue gas flow direction and an electron beam generating device after the last gas distribution tube plate; the flue gas flows through the dust removal device, the spray device, the mixed reaction device and the absorption device in sequence; an ammonia inlet is arranged between the flue gas inlet of the mixed reaction device and the first gas distribution tube plate, and the ammonia inlet is connected to the ammonia supply device; an oxygen inlet is arranged between the first gas distribution tube plate and the last gas distribution tube plate, and the oxygen inlet is connected to the oxygen supply device. The system can reduce ammonia emissions, which is beneficial to improving the desulfurization and denitrification effects of flue gas and reducing the impact of purified gas on the environment.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas treatment, and in particular to a system and method for desulfurization and denitrification, and in particular to a system and method for desulfurization and denitrification coordinated by electron beam and oxygen. Background Art

[0002] Pollutants such as SO2 and nitrogen oxides in flue gas can cause serious pollution to the atmosphere. Current desulfurization methods include acid method, subtraction method, limestone-gypsum wet method, double alkali method, ammonia method and metal oxide method; the main denitrification methods include selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR). Although the SCR method can achieve a high denitrification efficiency and meet the flue gas emission standards, its process and equipment system are complex and require special catalysts. The investment and operation costs of the entire system are high; although the SNCR method has a simple process and equipment system, and the investment and operation costs are low, its denitrification efficiency is not high.

[0003] The technology of using electron beam irradiation to desulfurize and denitrate flue gas is a coal-fired flue gas purification technology developed in recent years. At present, this technology has entered the stage of industrial application. Electron beam flue gas desulfurization and denitrification technology uses a high-energy electron beam to irradiate oxygen containing pollutants such as sulfur oxides and nitrogen oxides, ionize or excite the main components in the flue gas, and produce highly active and oxidizing free radicals. These free radicals oxidize sulfur oxides and nitrogen oxides in the flue gas at a very fast rate to generate high-valent sulfur oxides and nitrogen oxides. The high-valent sulfur oxides and nitrogen oxides react with moisture and ammonia in the flue gas to generate by-products whose main components are ammonium sulfate and ammonium nitrate. The by-products are collected and removed to achieve flue gas purification.

[0004] CN 104258702 A discloses a method and device for electron beam flue gas desulfurization and denitration, the method comprising the following steps: (1) heat exchanging the flue gas generated by the boiler with the flue gas of the first desulfurization and denitration to cool the flue gas generated by the boiler; (2) mixing the cooled flue gas with ammonia, and then spraying with water to complete the first desulfurization and denitration; (3) heat exchanging the flue gas of the first desulfurization and denitration with the flue gas generated by the boiler, so that the flue gas of the first desulfurization and denitration is further subjected to electron beam irradiation reaction to complete the second desulfurization and denitration. The method and device for electron beam flue gas desulfurization and denitration can effectively utilize the heat of the flue gas, and respectively reach the optimal removal temperature of sulfur oxides and nitrogen oxides in the two-step treatment process of desulfurization and denitration, but the method and device need to consume a large amount of ammonia, and the purified tail gas containing ammonia needs to be reprocessed.

[0005] CN 109499326 A discloses a method for desulfurizing and denitrifying flue gas. The method for preparing raw materials and removing nitrates comprises the following steps: S1, material selection: selecting distilled water and boiling the water; S2, selection: selecting FeCl3 solution; S3, dropping the FeCl3 solution into waste water and continuing to boil until a reddish brown liquid is generated, thereby obtaining a desulfurizer; S4, cooling the flue gas to 50-100°C through a heat exchanger, and passing the flue gas into the obtained desulfurizer to carry out a desulfurization reaction; S5, passing the flue gas into the obtained denitrifier to carry out a denitrification reaction; S6, simultaneously irradiating the flue gas desulfurized and denitrified for the first time with ultraviolet rays and electron beams to obtain a flue gas desulfurized and denitrified for the second time; S7, water spraying treatment; S8, discharging the denitrated coke oven flue gas through an induced draft fan. The method requires two desulfurization and denitrification treatments for the flue gas containing sulfur oxides and nitrogen oxides, and the second desulfurization and denitrification treatment requires simultaneous ultraviolet irradiation and electron beam irradiation, which is a relatively complicated process and is not conducive to reducing the cost of flue gas desulfurization and denitrification.

[0006] CN 208660765 U discloses an electron beam ammonia desulfurization and denitration reactor, the reactor comprises an annular tube, a mesh cover, a flue gas inlet, a flue gas outlet, an ammonia inlet, and an electron beam incident port; the mesh cover is arranged inside the annular tube, the flue gas inlet is connected to the inside of the mesh cover, the flue gas outlet is arranged outside the mesh cover and connected to the annular tube; the ammonia inlet is arranged near the flue gas inlet and connected to the inside of the mesh cover; the electron beam incident port is arranged near the flue gas inlet, and the mesh cover part is on the electron beam path emitted from the electron beam incident port. However, the mixing range of ammonia and flue gas in the electron beam ammonia desulfurization and denitration reactor is limited, it is difficult for flue gas and ammonia to achieve an ideal mixing effect, and the effect of electron beam irradiation is limited.

[0007] Therefore, a system and method for electron beam and oxygen coordinated desulfurization and denitrification is provided, which has simple purifier treatment after desulfurization and denitrification, has a high degree of mixing between flue gas and additives used for desulfurization and denitrification and can reduce ammonia emissions. This is beneficial to improving the desulfurization and denitrification effects of flue gas and reducing the impact of purified gas on the environment. Summary of the invention

[0008] The purpose of the present invention is to provide a system and method for electron beam and oxygen synergistic desulfurization and denitrification, the system can improve the mixing effect of ammonia and flue gas, and can make oxygen and electron beam system, thereby improving the treatment effect of nitrogen oxides and sulfur oxides in flue gas. And the content of ammonia in the treated tail gas is low, which is conducive to the post-treatment of desulfurization and denitrification gas.

[0009] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides an electron beam and oxygen coordinated desulfurization and denitrification system, the system comprising a dust removal device, a spray device, a mixing reaction device, an absorption device, an oxygen supply device and an ammonia supply device.

[0011] The mixed reaction device comprises at least two gas distribution tube plates which are sequentially arranged inside the shell along the flue gas flow direction and an electron beam generating device after the last gas distribution tube plate.

[0012] The flue gas flows through the dust removal device, the spraying device, the mixing reaction device and the absorption device in sequence; an ammonia inlet is provided between the flue gas inlet of the mixing reaction device and the first gas distribution tube plate, and the ammonia inlet is connected to the ammonia supply device; an oxygen inlet is provided between the first gas distribution tube plate and the last gas distribution tube plate, and the oxygen inlet is connected to the oxygen supply device.

[0013] The dust removal device of the present invention includes but is not limited to a cyclone separator, as long as it can remove solid particles in the flue gas; the spray device includes but is not limited to a spray tower, as long as it can achieve further dust removal and cooling of the flue gas by spraying water; the present invention does not make specific limitations on the dust removal device and the spray device. In addition, the oxygen supply device and the ammonia supply device of the present invention are conventional devices in the art that can supply oxygen or ammonia, and the present invention does not make specific limitations here.

[0014] In order to facilitate the flow of flue gas and the arrangement of components, the shell is a rectangular shell or a cylindrical shell; the number of gas distribution pipe plates in the mixed reaction device is at least 2, for example, it can be 2, 3, 4, 5, 6 or 7. Those skilled in the art can reasonably set it according to the length of the shell of the mixed reaction device, preferably 2-6, and more preferably 3.

[0015] When the electron beam and oxygen coordinated desulfurization and denitrification system is used to desulfurize and denitrify flue gas, the flue gas is first subjected to dust removal and spray cooling, which not only reduces the temperature of the flue gas to a temperature suitable for electron beam irradiation, but also adjusts the relative humidity of the flue gas to the required range. The flue gas that has been sprayed and cooled is mixed with ammonia and flows through the gas distribution duct plate, so that the flue gas and ammonia are evenly mixed; then, the mixed ammonia mixed gas flows through the gas distribution duct plate under the impact of a larger flow of oxygen-containing gas, so that oxygen, ammonia and flue gas can be evenly mixed. The evenly mixed gas reacts under the irradiation of the electron beam emitted by the electron beam generator, and the O2 and H2O in the mixed gas are converted into a large number of ·OH and ·O free radicals. These free radicals react with SO2 and nitrogen oxides in the flue gas at an extremely fast rate to generate H2SO4 and HNO3. H2SO4 and HNO3 react with ammonia to generate by-products of ammonium nitrate and ammonium sulfate.

[0016] Excessive ammonia is converted into NO and NO2 in the presence of oxygen, and NO and NO2 can react with NH3. By adjusting the ratio of ammonia, oxygen and flue gas, the content of nitrogen oxides and sulfur oxides in the treated purified gas can be reduced, and the NH3 content can be reduced, thereby reducing the difficulty of subsequent treatment of the purified gas.

[0017] The electron beam generating device described in the present invention is a device capable of emitting electron beams, including a device arranged inside a shell and capable of emitting electron beams; or, an electron beam emitting port arranged at a corresponding position of the shell, and an electron beam generator arranged outside injects the generated electron beam into the mixed reaction device through the electron beam emitting port.

[0018] Preferably, the gas distribution tube plate comprises a tower plate with through holes, and the through holes are connected to matching gas mixing tubes.

[0019] The through hole of the present invention is connected with a matching gas mixing tube, which means that the diameter of the gas mixing tube is equal to the diameter of the through hole connected thereto, so that the gas mixing tube plays a guiding role. Ammonia and flue gas flow through the gas mixing tube to complete preliminary mixing, and then mix with the oxygen-containing gas, and finally the oxygen, ammonia and flue gas are evenly distributed in the obtained mixed gas.

[0020] Preferably, a fixing part is arranged at the central axis of the gas mixing tube, and rotating parts which rotate along with the flow of flue gas are arranged at intervals on the fixing part.

[0021] The rotating member of the present invention includes but is not limited to propeller blades, which can rotate under the impetus of the flowing gas and change the flow direction of the flowing gas, thereby increasing the turbulence of the gas. Those skilled in the art can reasonably set the number of rotating members according to the length of the gas mixing tube; as a preferred technical solution, at least three rotating members are evenly and evenly spaced on the fixed member.

[0022] Preferably, along the flow direction of the smoke, wind shielding members are provided on both sides of the rotating shaft of the rotating member.

[0023] The wind shield member of the present invention is fixed to the fixed member and arranged on both sides of the rotating shaft of the rotating member, which can not only limit the rotating member, but also reduce the adverse effects of solid particles in the gas on the rotating shaft of the rotating member, thereby increasing the service life of the rotating member.

[0024] Preferably, the aspect ratio of the gas mixing tube is 5-15, for example, it can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] Preferably, the tower plate is provided with 4-8 layers of through holes from the center of the tower plate along the radial direction of the tower plate, and the through holes of each layer are arranged in a circular array, wherein the first layer of through holes is a through hole located in the center of the tower plate.

[0026] The number of through-hole layers on the tower plate is 4-8 layers, for example, it can be 4 layers, 5 layers, 6 layers, 7 layers or 8 layers. Those skilled in the art can reasonably set the number of through-hole layers and the spacing between two adjacent layers according to the size of the tower plate and the diameter of the through-holes, and the present invention does not make too many limitations here.

[0027] Preferably, the diameters of the through holes in each layer are equal.

[0028] The present invention does not specifically limit the number and diameter of the through holes in each layer on the tower plate, as long as the space of the tower plate is fully utilized, and those skilled in the art can reasonably set them according to the processing cost and difficulty.

[0029] Preferably, it is characterized in that the absorption device includes an absorption horizontal pipe and an absorption vertical pipe, and the bottom end of the absorption vertical pipe is connected to one end of the absorption horizontal pipe. The absorption horizontal pipe is provided with a desulfurization and denitration gas inlet relative to the other end connected to the absorption vertical pipe, and the desulfurization and denitration gas inlet is connected to the absorption horizontal pipe through a diameter change; a spray horizontal pipe is provided in the tube cavity of the absorption horizontal pipe, and a conical diverter plate is provided on the side of the spray horizontal pipe close to the desulfurization and denitration gas inlet. A purified gas outlet is provided at the top of the absorption vertical pipe; a spray vertical pipe is provided in the tube cavity of the absorption vertical pipe; a defogger is provided between the spray vertical pipe and the purified gas outlet; the bottom of the absorption horizontal pipe is connected to an absorption liquid storage chamber, and the absorption liquid in the absorption liquid storage chamber is independently connected to the bottom of the spray vertical pipe and the side of the spray horizontal pipe away from the desulfurization and denitration gas inlet through a conveying device.

[0030] When the absorption device provided by the present invention is used to absorb desulfurized and denitrified gases, the desulfurized and denitrified gases enter the absorption transverse tube from the desulfurized and denitrified gas inlet, and flow into the surroundings of the spray transverse tube under the diversion effect of the conical diverter plate, so that the desulfurized and denitrified gases are evenly contacted with the absorption liquid sprayed from the spray transverse tube, completing the preliminary absorption of the absorption liquid and the desulfurized and denitrified gases.

[0031] After the initial absorption, the temperature of the desulfurized and denitrified gas drops, and the flue gas flowing into the absorption vertical pipe flows from bottom to top, and contacts the absorption liquid sprayed from the spray vertical pipe in countercurrent, thereby completing the deep absorption of the absorption liquid and the desulfurized and denitrified gas. The purified desulfurized and denitrified gas flows out from the purified gas outlet after being defogged by the defogger.

[0032] Preferably, the spray cross pipe is provided with 4-10 layers of nozzles along its axial direction, and each layer of nozzles includes 3-6 nozzles evenly arranged along the radial direction of the spray cross pipe.

[0033] The number of layers of nozzles in the axial direction of the spray cross pipe is 4-10 layers, for example, it can be 4 layers, 5 layers, 6 layers, 7 layers, 8 layers, 9 layers or 10 layers; the 4-10 layers of nozzles arranged along the axial direction of the spray cross pipe are uniformly arranged, and the uniform arrangement means that the nozzles of two adjacent layers are arranged at equal intervals. Those skilled in the art can reasonably arrange the intervals between two adjacent layers of nozzles according to the length of the spray cross pipe. The uniform arrangement of 3-6 nozzles in each layer means that when there are 3 nozzles, the angle between two adjacent nozzles is 120°; when there are 4 nozzles, the angle between two adjacent nozzles is 90°; when there are 5 nozzles, the angle between two adjacent nozzles is 72°; when there are 6 nozzles, the angle between two adjacent nozzles is 60°.

[0034] Preferably, the spray standpipe is provided with 4-10 layers of nozzles along its axial direction, and each layer of nozzles includes 3-6 nozzles evenly arranged along the radial direction of the spray standpipe.

[0035] The number of layers of nozzles in the axial direction of the spray vertical pipe is 4-10 layers, for example, it can be 4 layers, 5 layers, 6 layers, 7 layers, 8 layers, 9 layers or 10 layers; the 4-10 layers of nozzles arranged along the axial direction of the spray vertical pipe are uniformly arranged, and the uniform arrangement means that the nozzles of two adjacent layers are arranged at equal intervals. Those skilled in the art can reasonably arrange the intervals between two adjacent layers of nozzles according to the length of the spray vertical pipe. The uniform arrangement of 3-6 nozzles in each layer means that when there are 3 nozzles, the angle between two adjacent nozzles is 120°; when there are 4 nozzles, the angle between two adjacent nozzles is 90°; when there are 5 nozzles, the angle between two adjacent nozzles is 72°; when there are 6 nozzles, the angle between two adjacent nozzles is 60°.

[0036] In a second aspect, the present invention provides a method for desulfurization and denitrification using the system for coordinated desulfurization and denitrification with electron beam and oxygen as described in the first aspect, the method comprising the following steps:

[0037] (1) After dust removal and cooling, the flue gas is mixed with ammonia to form an ammonia mixed gas;

[0038] (2) mixing oxygen with the ammonia obtained in step (1), and subjecting the obtained mixed gas to electron beam irradiation reaction to obtain desulfurized and denitrified gas;

[0039] (3) Using an absorption liquid to spray and absorb the desulfurized and denitrified gas obtained in step (2) to obtain purified gas and absorbed liquid.

[0040] Preferably, the temperature of the flue gas after dust removal and cooling in step (1) is 50-70°C, for example, it can be 50°C, 55°C, 60°C, 65°C or 70°C, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable; the relative humidity is 60-80%, for example, it can be 60%, 65%, 70%, 75% or 80%, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0041] Preferably, the flow rate of the flue gas in step (1) is 200000-300000Nm 3 / h, for example, it can be 200000Nm 3 / h、210000Nm 3 / h、220000Nm 3 / h、230000Nm 3 / h、240000Nm 3 / h、250000Nm 3 / h、260000Nm 3 / h、270000Nm 3 / h or 300000Nm 3 / h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0042] Preferably, the mass concentration of SO2 in the flue gas in step (1) is 500-800 mg / Nm 3 , for example, it can be 500mg / Nm 3 、550mg / Nm 3 、600mg / Nm 3 、650mg / Nm 3 、700mg / Nm 3 、750mg / Nm 3 or 800mg / Nm 3 , but not limited to the listed values, other values ​​not listed in the numerical range are also applicable; the mass concentration of nitrogen oxides ≤ 300mg / Nm 3 , for example, it can be 100 mg / Nm 3 、150mg / Nm 3 、200mg / Nm 3 、250mg / Nm 3 or 300mg / Nm 3 , but not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0043] Preferably, the ratio of the ammonia gas in step (1) to the total molar amount of SO2 and nitrogen oxides in the flue gas is (1-1.5):1, for example, it can be 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1 or 1.5:1, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0044] The ratio of the ammonia gas to the total molar amount of SO2 and nitrogen oxides in the flue gas is ammonia molar amount: (SO2 molar amount + nitrogen oxide molar amount).

[0045] Preferably, the molar ratio of the oxygen in step (2) to the ammonia in step (1) is (0.6-1.5):1, for example, it can be 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1 or 1.5:1, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0046] Preferably, the temperature of the electron beam irradiation in step (2) is 50-70°C, for example, 50°C, 55°C, 60°C, 65°C or 70°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0047] Preferably, the time for the electron beam irradiation reaction of the mixed gas in step (2) is 10-20 seconds, for example, it can be 10 seconds, 12 seconds, 15 seconds, 16 seconds, 18 seconds or 20 seconds, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0048] Preferably, the absorption liquid in step (3) is water and / or aqueous ammonia.

[0049] Excessive ammonia is beneficial to the oxidation of nitrogen oxides and sulfur oxides in the flue gas to form ammonium sulfate and ammonium nitrate. Ozone reacts with ammonia to form NO and NO2, and NO and NO2 react with ammonia water to form ammonium nitrite and ammonium nitrate. Using water and / or ammonia water as the absorption liquid can further reduce the total nitrogen content in the desulfurized and denitrified gas, and further reduce the total nitrogen content in the purified gas.

[0050] As a preferred technical solution of the method described in the second aspect of the present invention, the method comprises the following steps:

[0051] (1) Flow rate is 200000-300000Nm 3 / h The flue gas is mixed with ammonia after dust removal and cooling. The temperature of the flue gas after dust removal and cooling is 50-70℃, and the relative humidity is 60-80%, forming an ammonia mixed gas; the mass concentration of SO2 in the flue gas is 500-800mg / Nm 3 , the mass concentration of nitrogen oxides ≤300mg / Nm3 ; The ratio of ammonia to the total molar amount of SO2 and nitrogen oxides in the flue gas is (1-1.5):1

[0052] (2) mixing oxygen and ammonia obtained in step (1) in a molar ratio of (0.6-1.5):1, subjecting the obtained mixed gas to electron beam irradiation for 0.5-1s at 50-70°C to obtain desulfurized and denitrified gas;

[0053] (3) Using an absorption liquid to spray and absorb the desulfurized and denitrified gas obtained in step (2) to obtain purified gas and absorbed liquid; the absorption liquid is water and / or aqueous ammonia.

[0054] The system refers to an equipment system, a device system or a production device.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] (1) The present invention utilizes the synergistic effect of oxygen and electron beam to improve the effect of flue gas desulfurization and denitrification, and the electron beam and oxygen synergistic desulfurization and denitrification system improves the mixing effect of the gas through the application of a mixed reaction device, further improving the effect of flue gas desulfurization and denitrification;

[0057] (2) The electron beam and oxygen synergistic desulfurization and denitrification system of the present invention can treat flue gas at 50-70°C, requiring a low temperature; and the content of SO2, nitrogen oxides and total nitrogen in the purified gas is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 A schematic diagram of the structure of the electron beam and oxygen coordinated desulfurization and denitrification system provided by the present invention;

[0059] Figure 2 This is a schematic structural diagram of the gas mixing tube provided by the present invention.

[0060] Among them: 1, dust removal device; 2, spray device; 3, ammonia supply device; 4, oxygen supply device; 5, gas distribution pipe plate; 6, electron beam generating device; 7, absorption device; 71, desulfurization and denitrification gas inlet; 72, reducer; 73, spray horizontal pipe; 74, spray vertical pipe; 75, nozzle; 76, demisting device; 77, purified gas outlet; 78, absorption liquid storage chamber; 79, conical diverter plate. DETAILED DESCRIPTION

[0061] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0062] As a preferred technical solution of a system for coordinated desulfurization and denitrification by electron beam and oxygen provided by the present invention, the structural schematic diagram of the system for coordinated desulfurization and denitrification by electron beam and oxygen is as follows: Figure 1 As shown, it includes a dust removal device 1, a spray device 2, a mixing reaction device, an absorption device 7, an oxygen supply device 4 and an ammonia supply device 3.

[0063] The mixed reaction device comprises at least two gas distribution tube plates 5 sequentially arranged inside the shell along the flue gas flow direction and an electron beam generating device 6 after the last gas distribution tube plate 5 .

[0064] The flue gas flows through the dust removal device 1, the spray device 2, the mixing reaction device and the absorption device 7 in sequence; an ammonia inlet is provided between the flue gas inlet of the mixing reaction device and the first gas distribution tube plate 5, and the ammonia inlet is connected to the ammonia supply device 3; an oxygen inlet is provided between the first gas distribution tube plate 5 and the last gas distribution tube plate 5, and the oxygen inlet is connected to the oxygen supply device 4.

[0065] The gas distribution tube plate 5 includes a tower plate with through holes, and the through holes are connected to gas mixing tubes matched therewith. The structural schematic diagram of the gas mixing tube is as shown in FIG. Figure 2 The central axis of the gas mixing tube is provided with a fixing part, on which rotating parts rotating with the flow of smoke are arranged at intervals, and the rotating parts are propeller blades; along the flow direction of smoke, wind shielding parts are arranged on both sides of the rotating axis of the rotating parts; the aspect ratio of the gas mixing tube is 5-15.

[0066] The tower plate is provided with 4-8 layers of through holes from the center of the tower plate along the radial direction of the tower plate, and the through holes of each layer are arranged in a circular array, wherein the first layer of through holes is a through hole located in the center of the tower plate.

[0067] The absorption device 7 includes an absorption horizontal tube and an absorption vertical tube, the bottom end of the absorption vertical tube is connected to one end of the absorption horizontal tube; the absorption horizontal tube is provided with a desulfurization and denitrification gas inlet 71 relative to the other end connected to the absorption vertical tube, and the desulfurization and denitrification gas is connected to the absorption horizontal tube through a reducer 72; a spray horizontal tube 73 is provided in the tube cavity of the absorption horizontal tube, and a conical diverter plate 79 is provided on the side of the spray horizontal tube 73 close to the desulfurization and denitrification gas inlet 71; a purified gas outlet 77 is provided at the top of the absorption vertical tube; a spray vertical tube 74 is provided in the tube cavity of the absorption vertical tube; a defogger 76 is provided between the spray vertical tube 74 and the purified gas outlet 77; the bottom of the absorption horizontal tube is connected to an absorption liquid storage chamber 78, and the absorption liquid in the absorption liquid storage chamber 78 is independently connected to the bottom of the spray vertical tube 74 and the side of the spray horizontal tube 73 away from the desulfurization and denitrification gas inlet 71 through a conveying device.

[0068] The spray horizontal pipe 73 is provided with 4-10 layers of nozzles 75 along its axial direction, and each layer of nozzles 75 includes 3-6 nozzles 75 evenly arranged along the radial direction of the spray horizontal pipe 73; preferably, the spray vertical pipe 74 is provided with 4-10 layers of nozzles 75 along its axial direction, and each layer of nozzles 75 includes 3-6 nozzles 75 evenly arranged along the radial direction of the spray vertical pipe 74.

[0069] When the electron beam and oxygen coordinated desulfurization and denitrification system is used to desulfurize and denitrify flue gas, the flue gas is first subjected to dust removal and spray cooling, which not only reduces the temperature of the flue gas to a temperature suitable for electron beam irradiation, but also adjusts the relative humidity of the flue gas to the required range. The flue gas that has been sprayed and cooled is mixed with ammonia and flows through the gas distribution duct plate 5, so that the flue gas and ammonia are evenly mixed; then, the mixed ammonia mixed gas flows through the gas distribution duct plate 5 under the impact of a larger flow of oxygen-containing gas, so that oxygen, ammonia and flue gas can be evenly mixed. The evenly mixed gas reacts under the irradiation of the electron beam emitted by the electron beam generator 6, and the O2 and H2O in the mixed gas are converted into a large number of ·OH and ·O free radicals. These free radicals react with SO2 and nitrogen oxides in the flue gas at a very fast rate to generate H2SO4 and HNO3. H2SO4 and HNO3 react with ammonia to generate by-products of ammonium nitrate and ammonium sulfate.

[0070] Excessive ammonia is converted into NO and NO2 in the presence of oxygen, and NO and NO2 can react with NH3. By adjusting the ratio of ammonia, oxygen and flue gas, the content of nitrogen oxides and sulfur oxides in the treated purified gas can be reduced, and the NH3 content can be reduced, thereby reducing the difficulty of subsequent treatment of the purified gas.

[0071] Example 1

[0072] The present embodiment provides an electron beam and oxygen coordinated desulfurization and denitrification system, which includes a dust removal device 1, a spray device 2, a mixing reaction device, an absorption device 7, an oxygen supply device 4 and an ammonia supply device 3.

[0073] The dust removal device 1 is a cyclone separator, and the spray device 2 is a spray tower.

[0074] The mixed reaction device comprises three gas distribution tube plates 5 sequentially arranged inside the shell along the flue gas flow direction and an electron beam generating device 6 after the last gas distribution tube plate 5 .

[0075] The flue gas flows through the dust removal device 1, the spray device 2, the mixing reaction device and the absorption device 7 in sequence; an ammonia inlet is arranged between the flue gas inlet of the mixing reaction device and the first gas distribution tube plate 5, and the ammonia inlet is connected to the ammonia supply device 3; an oxygen inlet is arranged between the second gas distribution tube plate 5 and the third gas distribution tube plate 5, and the oxygen inlet is connected to the oxygen supply device 4.

[0076] The gas distribution tube plate 5 includes a tower plate with through holes, and the through holes are connected to a gas mixing tube matched therewith. A fixing part is arranged at the central axis of the gas mixing tube, and rotating parts rotating with the flow of flue gas are arranged evenly at intervals on the fixing part, and the rotating parts are propeller blades; along the flow direction of flue gas, wind shielding parts are arranged on both sides of the rotating shaft of the rotating part; the aspect ratio of the gas mixing tube is 10.

[0077] The tower plate is provided with 6 layers of through holes from the center of the tower plate along the radial direction of the tower plate, and the through holes of each layer are arranged in a circular array, wherein the first layer of through holes is a through hole located in the center of the tower plate.

[0078] The absorption device 7 includes an absorption horizontal tube and an absorption vertical tube, the bottom end of the absorption vertical tube is connected to one end of the absorption horizontal tube; the absorption horizontal tube is provided with a desulfurization and denitrification gas inlet 71 relative to the other end connected to the absorption vertical tube, and the desulfurization and denitrification gas is connected to the absorption horizontal tube through a reducer 72; a spray horizontal tube 73 is provided in the tube cavity of the absorption horizontal tube, and a conical diverter plate 79 is provided on the side of the spray horizontal tube 73 close to the desulfurization and denitrification gas inlet 71; a purified gas outlet 77 is provided at the top of the absorption vertical tube; a spray vertical tube 74 is provided in the tube cavity of the absorption vertical tube; a defogger 76 is provided between the spray vertical tube 74 and the purified gas outlet 77; the bottom of the absorption horizontal tube is connected to an absorption liquid storage chamber 78, and the absorption liquid in the absorption liquid storage chamber 78 is independently connected to the bottom of the spray vertical tube 74 and the side of the spray horizontal tube 73 away from the desulfurization and denitrification gas inlet 71 through a conveying device.

[0079] The spray horizontal pipe 73 is provided with 7 layers of nozzles 75 along its axial direction, and each layer of nozzles 75 includes 4 nozzles 75 evenly arranged along the radial direction of the spray horizontal pipe 73; preferably, the spray vertical pipe 74 is provided with 7 layers of nozzles 75 along its axial direction, and each layer of nozzles 75 includes 4 nozzles 75 evenly arranged along the radial direction of the spray vertical pipe 74.

[0080] Example 2

[0081] The present embodiment provides an electron beam and oxygen coordinated desulfurization and denitrification system, which includes a dust removal device 1, a spray device 2, a mixing reaction device, an absorption device 7, an oxygen supply device 4 and an ammonia supply device 3.

[0082] The dust removal device 1 is a cyclone separator, and the spray device 2 is a spray tower.

[0083] The mixed reaction device comprises two gas distribution tube plates 5 which are sequentially arranged inside the shell along the flue gas flow direction and an electron beam generating device 6 after the last gas distribution tube plate 5 .

[0084] The flue gas flows through the dust removal device 1, the spray device 2, the mixing reaction device and the absorption device 7 in sequence; an ammonia inlet is arranged between the flue gas inlet of the mixing reaction device and the first gas distribution tube plate 5, and the ammonia inlet is connected to the ammonia supply device 3; an oxygen inlet is arranged between the first gas distribution tube plate 5 and the second gas distribution tube plate 5, and the oxygen inlet is connected to the oxygen supply device 4.

[0085] The gas distribution tube plate 5 includes a tower plate with through holes, and the through holes are connected to a gas mixing tube matched therewith. A fixing part is arranged at the central axis of the gas mixing tube, and rotating parts rotating with the flow of smoke are arranged evenly at intervals on the fixing part, and the rotating parts are propeller blades; along the flow direction of smoke, wind shielding parts are arranged on both sides of the rotating shaft of the rotating part; the aspect ratio of the gas mixing tube is 15.

[0086] The tower plate is provided with 8 layers of through holes from the center of the tower plate along the radial direction of the tower plate, and the through holes of each layer are arranged in a circular array, wherein the first layer of through holes is a through hole located in the center of the tower plate.

[0087] The absorption device 7 includes an absorption horizontal tube and an absorption vertical tube, the bottom end of the absorption vertical tube is connected to one end of the absorption horizontal tube; the absorption horizontal tube is provided with a desulfurization and denitrification gas inlet 71 relative to the other end connected to the absorption vertical tube, and the desulfurization and denitrification gas is connected to the absorption horizontal tube through a reducer 72; a spray horizontal tube 73 is provided in the tube cavity of the absorption horizontal tube, and a conical diverter plate 79 is provided on the side of the spray horizontal tube 73 close to the desulfurization and denitrification gas inlet 71; a purified gas outlet 77 is provided at the top of the absorption vertical tube; a spray vertical tube 74 is provided in the tube cavity of the absorption vertical tube; a defogger 76 is provided between the spray vertical tube 74 and the purified gas outlet 77; the bottom of the absorption horizontal tube is connected to an absorption liquid storage chamber 78, and the absorption liquid in the absorption liquid storage chamber 78 is independently connected to the bottom of the spray vertical tube 74 and the side of the spray horizontal tube 73 away from the desulfurization and denitrification gas inlet 71 through a conveying device.

[0088] The spray horizontal pipe 73 is provided with 10 layers of nozzles 75 along its axial direction, and each layer of nozzles 75 includes 3 nozzles 75 evenly arranged along the radial direction of the spray horizontal pipe 73; preferably, the spray vertical pipe 74 is provided with 10 layers of nozzles 75 along its axial direction, and each layer of nozzles 75 includes 3 nozzles 75 evenly arranged along the radial direction of the spray vertical pipe 74.

[0089] Example 3

[0090] The present embodiment provides an electron beam and oxygen coordinated desulfurization and denitrification system, which includes a dust removal device 1, a spray device 2, a mixing reaction device, an absorption device 7, an oxygen supply device 4 and an ammonia supply device 3.

[0091] The dust removal device 1 is a cyclone separator, and the spray device 2 is a spray tower.

[0092] The mixed reaction device comprises six gas distribution tube plates 5 sequentially arranged inside the shell along the flue gas flow direction and an electron beam generating device 6 after the last gas distribution tube plate 5 .

[0093] The flue gas flows through the dust removal device 1, the spray device 2, the mixing reaction device and the absorption device 7 in sequence; an ammonia inlet is arranged between the flue gas inlet of the mixing reaction device and the first gas distribution tube plate 5, and the ammonia inlet is connected to the ammonia supply device 3; an oxygen inlet is arranged between the fifth gas distribution tube plate 5 and the sixth gas distribution tube plate 5, and the oxygen inlet is connected to the oxygen supply device 4.

[0094] The gas distribution tube plate 5 includes a tower plate with through holes, and the through holes are connected to a gas mixing tube matched therewith. A fixing part is arranged at the central axis of the gas mixing tube, and rotating parts rotating with the flow of flue gas are arranged evenly at intervals on the fixing part, and the rotating parts are propeller blades; along the flow direction of flue gas, wind shielding parts are arranged on both sides of the rotating shaft of the rotating part; the aspect ratio of the gas mixing tube is 5.

[0095] The tower plate is provided with 4 layers of through holes from the center of the tower plate along the radial direction of the tower plate, and the through holes of each layer are arranged in a circular array, wherein the first layer of through holes is a through hole located in the center of the tower plate.

[0096] The absorption device 7 includes an absorption horizontal tube and an absorption vertical tube, the bottom end of the absorption vertical tube is connected to one end of the absorption horizontal tube; the absorption horizontal tube is provided with a desulfurization and denitrification gas inlet 71 relative to the other end connected to the absorption vertical tube, and the desulfurization and denitrification gas is connected to the absorption horizontal tube through a reducer 72; a spray horizontal tube 73 is provided in the tube cavity of the absorption horizontal tube, and a conical diverter plate 79 is provided on the side of the spray horizontal tube 73 close to the desulfurization and denitrification gas inlet 71; a purified gas outlet 77 is provided at the top of the absorption vertical tube; a spray vertical tube 74 is provided in the tube cavity of the absorption vertical tube; a defogger 76 is provided between the spray vertical tube 74 and the purified gas outlet 77; the bottom of the absorption horizontal tube is connected to an absorption liquid storage chamber 78, and the absorption liquid in the absorption liquid storage chamber 78 is independently connected to the bottom of the spray vertical tube 74 and the side of the spray horizontal tube 73 away from the desulfurization and denitrification gas inlet 71 through a conveying device.

[0097] The spray horizontal pipe 73 is provided with 4 layers of nozzles 75 along its axial direction, and each layer of nozzles 75 includes 6 nozzles 75 evenly arranged along the radial direction of the spray horizontal pipe 73; preferably, the spray vertical pipe 74 is provided with 4 layers of nozzles 75 along its axial direction, and each layer of nozzles 75 includes 6 nozzles 75 evenly arranged along the radial direction of the spray vertical pipe 74.

[0098] Application Example 1

[0099] This application example provides a method for desulfurization and denitrification using the electron beam and oxygen coordinated desulfurization and denitrification system provided in Example 1, the method comprising the following steps:

[0100] (1) Flow rate is 250000Nm 3 / h The flue gas is mixed with ammonia after dust removal and cooling. The temperature of the flue gas after dust removal and cooling is 60℃ and the relative humidity is 70%, forming an ammonia mixed gas; the mass concentration of SO2 in the flue gas is 800mg / Nm 3 , the mass concentration of nitrogen oxides is 300mg / Nm 3 ; The ratio of ammonia to the total molar amount of SO2 and nitrogen oxides in flue gas is 1.3:1

[0101] (2) mixing oxygen and the ammonia obtained in step (1) in a molar ratio of 1:1, and subjecting the obtained mixed gas to electron beam irradiation for 0.8 s at 60° C. to obtain desulfurized and denitrified gas;

[0102] (3) using an absorption liquid to spray and absorb the desulfurized and denitrified gas obtained in step (2) to obtain purified gas and absorbed liquid; the absorption liquid is aqueous ammonia.

[0103] Application Example 2

[0104] This application example provides a method for desulfurization and denitrification using the electron beam and oxygen coordinated desulfurization and denitrification system provided in Example 1, the method comprising the following steps:

[0105] (1) Flow rate is 210000Nm 3 / h The flue gas is mixed with ammonia after dust removal and cooling. The temperature of the flue gas after dust removal and cooling is 65℃ and the relative humidity is 75%, forming an ammonia mixed gas; the mass concentration of SO2 in the flue gas is 800mg / Nm 3 , the mass concentration of nitrogen oxides is 300mg / Nm 3 ; The ratio of ammonia to the total molar amount of SO2 and nitrogen oxides in flue gas is 1.2:1

[0106] (2) mixing oxygen and the ammonia obtained in step (1) in a molar ratio of 0.8:1, and subjecting the obtained mixed gas to electron beam irradiation reaction at 65° C. for 0.6 s to obtain desulfurized and denitrified gas;

[0107] (3) using an absorption liquid to spray and absorb the desulfurized and denitrified gas obtained in step (2) to obtain purified gas and absorbed liquid; the absorption liquid is aqueous ammonia.

[0108] Application Example 3

[0109] This application example provides a method for desulfurization and denitrification using the electron beam and oxygen coordinated desulfurization and denitrification system provided in Example 1, the method comprising the following steps:

[0110] (1) Flow rate is 270000Nm 3 / h The flue gas is mixed with ammonia after dust removal and cooling. The temperature of the flue gas after dust removal and cooling is 55℃ and the relative humidity is 65%, forming an ammonia mixed gas; the mass concentration of SO2 in the flue gas is 800mg / Nm 3 , the mass concentration of nitrogen oxides is 300mg / Nm 3 ; The ratio of ammonia to the total molar amount of SO2 and nitrogen oxides in flue gas is 1.4:1

[0111] (2) mixing oxygen and the ammonia obtained in step (1) in a molar ratio of 1.2:1, and subjecting the obtained mixed gas to electron beam irradiation reaction at 55° C. for 0.9 s to obtain desulfurized and denitrified gas;

[0112] (3) using an absorption liquid to spray and absorb the desulfurized and denitrified gas obtained in step (2) to obtain purified gas and absorbed liquid; the absorption liquid is aqueous ammonia.

[0113] Application Example 4

[0114] This application example provides a method for desulfurization and denitrification using the electron beam and oxygen coordinated desulfurization and denitrification system provided in Example 1, the method comprising the following steps:

[0115] (1) Flow rate is 200000Nm 3 / h The flue gas is mixed with ammonia after dust removal and cooling. The temperature of the flue gas after dust removal and cooling is 70℃ and the relative humidity is 80%, forming an ammonia mixed gas; the mass concentration of SO2 in the flue gas is 800mg / Nm 3 , the mass concentration of nitrogen oxides is 300mg / Nm 3 ; The ratio of ammonia to the total molar amount of SO2 and nitrogen oxides in flue gas is 1:1

[0116] (2) mixing oxygen and the ammonia obtained in step (1) in a molar ratio of 1.5:1, and subjecting the obtained mixed gas to electron beam irradiation reaction at 70° C. for 0.5 s to obtain desulfurized and denitrified gas;

[0117] (3) using an absorption liquid to spray and absorb the desulfurized and denitrified gas obtained in step (2) to obtain purified gas and absorbed liquid; the absorption liquid is aqueous ammonia.

[0118] Application Example 5

[0119] This application example provides a method for desulfurization and denitrification using the electron beam and oxygen coordinated desulfurization and denitrification system provided in Example 1, the method comprising the following steps:

[0120] (1) Flow rate is 300000Nm 3 / h flue gas is mixed with ammonia after dust removal and cooling. The temperature of the flue gas after dust removal and cooling is 50℃ and the relative humidity is 60%, forming an ammonia mixed gas; the mass concentration of SO2 in the flue gas is 800mg / Nm 3 , the mass concentration of nitrogen oxides is 300mg / Nm 3 ; The ratio of ammonia to the total molar amount of SO2 and nitrogen oxides in flue gas is 1.5:1

[0121] (2) mixing oxygen and the ammonia obtained in step (1) at a molar ratio of 0.6:1, and subjecting the obtained mixed gas to electron beam irradiation at 50° C. for 1 second to obtain desulfurized and denitrified gas;

[0122] (3) using an absorption liquid to spray and absorb the desulfurized and denitrified gas obtained in step (2) to obtain purified gas and absorbed liquid; the absorption liquid is aqueous ammonia.

[0123] Application Example 6

[0124] This application example provides a method for desulfurization and denitrification using the system for coordinated desulfurization and denitrification with electron beam and oxygen provided in Example 2, the method comprising the following steps:

[0125] (1) Flow rate is 250000Nm 3 / h The flue gas is mixed with ammonia after dust removal and cooling. The temperature of the flue gas after dust removal and cooling is 60℃ and the relative humidity is 70%, forming an ammonia mixed gas; the mass concentration of SO2 in the flue gas is 800mg / Nm 3 , the mass concentration of nitrogen oxides is 300mg / Nm 3 ; The ratio of ammonia to the total molar amount of SO2 and nitrogen oxides in flue gas is 1.3:1

[0126] (2) mixing oxygen and the ammonia obtained in step (1) in a molar ratio of 1:1, and subjecting the obtained mixed gas to electron beam irradiation for 0.8 s at 60° C. to obtain desulfurized and denitrified gas;

[0127] (3) Using an absorption liquid to spray and absorb the desulfurized and denitrified gas obtained in step (2) to obtain purified gas and absorbed liquid; the absorption liquid is water.

[0128] Application Example 7

[0129] This application example provides a method for desulfurization and denitrification using the electron beam and oxygen coordinated desulfurization and denitrification system provided in Example 3, the method comprising the following steps:

[0130] (1) Flow rate is 250000Nm 3 / h The flue gas is mixed with ammonia after dust removal and cooling. The temperature of the flue gas after dust removal and cooling is 60℃ and the relative humidity is 70%, forming an ammonia mixed gas; the mass concentration of SO2 in the flue gas is 800mg / Nm 3 , the mass concentration of nitrogen oxides is 300mg / Nm 3 ; The ratio of ammonia to the total molar amount of SO2 and nitrogen oxides in flue gas is 1.3:1

[0131] (2) mixing oxygen and the ammonia obtained in step (1) in a molar ratio of 1:1, and subjecting the obtained mixed gas to electron beam irradiation for 0.8 s at 60° C. to obtain desulfurized and denitrified gas;

[0132] (3) Using an absorption liquid to spray and absorb the desulfurized and denitrified gas obtained in step (2) to obtain purified gas and absorbed liquid; the absorption liquid is water.

[0133] Application Example 8

[0134] This application example provides a method for desulfurization and denitrification using the electron beam and oxygen coordinated desulfurization and denitrification system provided in Example 1, the method comprising the following steps:

[0135] (1) Flow rate is 250000Nm 3 / h The flue gas is mixed with ammonia after dust removal and cooling. The temperature of the flue gas after dust removal and cooling is 60℃ and the relative humidity is 70%, forming an ammonia mixed gas; the mass concentration of SO2 in the flue gas is 800mg / Nm 3 , the mass concentration of nitrogen oxides is 300mg / Nm 3 ; The ratio of ammonia to the total molar amount of SO2 and nitrogen oxides in flue gas is 0.8:1

[0136] (2) mixing oxygen and the ammonia obtained in step (1) in a molar ratio of 1:1, and subjecting the obtained mixed gas to electron beam irradiation for 0.8 s at 60° C. to obtain desulfurized and denitrified gas;

[0137] (3) using an absorption liquid to spray and absorb the desulfurized and denitrified gas obtained in step (2) to obtain purified gas and absorbed liquid; the absorption liquid is aqueous ammonia.

[0138] Application Example 9

[0139] This application example provides a method for desulfurization and denitrification using the electron beam and oxygen coordinated desulfurization and denitrification system provided in Example 1, the method comprising the following steps:

[0140] (1) Flow rate is 250000Nm 3 / h The flue gas is mixed with ammonia after dust removal and cooling. The temperature of the flue gas after dust removal and cooling is 60℃ and the relative humidity is 70%, forming an ammonia mixed gas; the mass concentration of SO2 in the flue gas is 800mg / Nm 3 , the mass concentration of nitrogen oxides is 300mg / Nm 3 ; The ratio of ammonia to the total molar amount of SO2 and nitrogen oxides in flue gas is 1.6:1

[0141] (2) mixing oxygen and the ammonia obtained in step (1) in a molar ratio of 1:1, and subjecting the obtained mixed gas to electron beam irradiation for 0.8 s at 60° C. to obtain desulfurized and denitrified gas;

[0142] (3) using an absorption liquid to spray and absorb the desulfurized and denitrified gas obtained in step (2) to obtain purified gas and absorbed liquid; the absorption liquid is aqueous ammonia.

[0143] Application Example 10

[0144] This application example provides a method for desulfurization and denitrification using the electron beam and oxygen coordinated desulfurization and denitrification system provided in Example 1, the method comprising the following steps:

[0145] (1) Flow rate is 250000Nm 3 / h The flue gas is mixed with ammonia after dust removal and cooling. The temperature of the flue gas after dust removal and cooling is 60℃ and the relative humidity is 70%, forming an ammonia mixed gas; the mass concentration of SO2 in the flue gas is 800mg / Nm 3 , the mass concentration of nitrogen oxides is 300mg / Nm 3 ; The ratio of ammonia to the total molar amount of SO2 and nitrogen oxides in flue gas is 1.3:1

[0146] (2) mixing oxygen and the ammonia obtained in step (1) at a molar ratio of 0.5:1, and subjecting the obtained mixed gas to electron beam irradiation reaction at 60° C. for 0.8 s to obtain desulfurized and denitrified gas;

[0147] (3) using an absorption liquid to spray and absorb the desulfurized and denitrified gas obtained in step (2) to obtain purified gas and absorbed liquid; the absorption liquid is aqueous ammonia.

[0148] Application Example 11

[0149] This application example provides a method for desulfurization and denitrification using the electron beam and oxygen coordinated desulfurization and denitrification system provided in Example 1, the method comprising the following steps:

[0150] (1) Flow rate is 250000Nm 3 / h The flue gas is mixed with ammonia after dust removal and cooling. The temperature of the flue gas after dust removal and cooling is 60℃ and the relative humidity is 70%, forming an ammonia mixed gas; the mass concentration of SO2 in the flue gas is 800mg / Nm 3 , the mass concentration of nitrogen oxides is 300mg / Nm 3 ; The ratio of ammonia to the total molar amount of SO2 and nitrogen oxides in flue gas is 1.3:1

[0151] (2) mixing oxygen and the ammonia obtained in step (1) in a molar ratio of 1.6:1, and subjecting the obtained mixed gas to electron beam irradiation reaction at 60° C. for 0.8 s to obtain desulfurized and denitrified gas;

[0152] (3) using an absorption liquid to spray and absorb the desulfurized and denitrified gas obtained in step (2) to obtain purified gas and absorbed liquid; the absorption liquid is aqueous ammonia.

[0153] The contents of SO2, nitrogen oxides and total nitrogen in the purified gas obtained in Example 1-11 were measured using a flue gas analyzer. The SO2 removal rate, nitrogen oxide removal rate and total nitrogen content are shown in Table 1.

[0154] Table 1

[0155]

[0156]

[0157] As shown in Table 1, when the electron beam and oxygen synergistic desulfurization and denitrification system provided by the present invention is used to desulfurize and denitrify flue gas, the removal rate of SO2 can reach more than 99%, the removal rate of nitrogen oxides can reach more than 96%, and the total nitrogen content is ≤16mg / Nm 3 .

[0158] It can be seen from Application Example 8 that when the amount of ammonia is reduced, the SO2 removal rate is reduced from 99.5% to 96.2%; the nitrogen oxide removal rate is reduced from 96.6% to 92.5%; the total nitrogen content is reduced from 13.3 mg / Nm 3 Increased to 28.2mg / Nm 3 .

[0159] It can be seen from Application Example 9 that when the amount of ammonia is too high, the SO2 removal rate can be increased from 99.5% to 99.6%, but the nitrogen oxide removal rate is reduced from 96.6% to 93.8%, which may be due to the reaction of excessive ammonia with ozone. At the same time, excessive ammonia causes the total nitrogen content to increase from 13.3 mg / Nm 3 Increased to 32.4 mg / Nm 3 .

[0160] As can be seen from Application Example 10, when the amount of oxygen is reduced, oxygen cannot play a synergistic role with ammonia, nor can it fully react with excess ammonia. The removal rate of SO2 is reduced to 97.4%, the removal rate of nitrogen oxides is reduced to 93.3%, and the total nitrogen content is increased to 25.1 mg / Nm 3 .

[0161] As can be seen from Application Example 11, when the amount of oxygen used is too much, the oxygen will produce too much ozone under the irradiation of the electron beam, and the ozone will react with ammonia to produce nitrogen oxides, which will affect the removal of total nitrogen. Although the use of ammonia absorbent can reduce the impact of some ozone, the final total nitrogen content will still rise to 31.0 mg / Nm 3 .

[0162] In summary, the present invention utilizes the synergistic effect of oxygen and electron beam to improve the effect of flue gas desulfurization and denitrification, and the electron beam and oxygen synergistic desulfurization and denitrification system improves the mixing effect of the gas through the application of a mixed reaction device, thereby further improving the effect of flue gas desulfurization and denitrification; the electron beam and oxygen synergistic desulfurization and denitrification system of the present invention can treat flue gas at 50-70°C, and the required temperature is low; and the content of SO2, nitrogen oxides and total nitrogen in the purified gas is low.

[0163] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. An electron beam and oxygen synergistic desulfurization and denitrification system, characterized in that: The system includes a dust removal device, a spray device, a mixing reaction device, an absorption device, an oxygen supply device and an ammonia supply device; The mixed reaction device comprises at least two gas distribution tube plates sequentially arranged inside the shell along the flue gas flow direction and an electron beam generating device behind the last gas distribution tube plate; The flue gas flows through the dust removal device, the spray device, the mixed reaction device and the absorption device in sequence; an ammonia inlet is provided between the flue gas inlet of the mixed reaction device and the first gas distribution tube plate, and the ammonia inlet is connected to the ammonia supply device; an oxygen inlet is provided between the first gas distribution tube plate and the last gas distribution tube plate, and the oxygen inlet is connected to the oxygen supply device; The absorption device comprises an absorption horizontal pipe and an absorption vertical pipe, and the bottom end of the absorption vertical pipe is connected to one end of the absorption horizontal pipe; The absorption horizontal tube is provided with a desulfurized and denitrated gas inlet at the other end thereof connected to the absorption vertical tube, and the desulfurized and denitrated gas is connected to the absorption horizontal tube through a diameter reducer; a spray horizontal tube is provided in the tube cavity of the absorption horizontal tube, and a conical diverter plate is provided on one side of the spray horizontal tube close to the desulfurized and denitrated gas inlet; The top of the absorption vertical pipe is provided with a purified gas outlet; a spray vertical pipe is provided in the tube cavity of the absorption vertical pipe; a demisting device is provided between the spray vertical pipe and the purified gas outlet; The bottom of the absorption horizontal tube is connected to an absorption liquid storage chamber, and the absorption liquid in the absorption liquid storage chamber is independently connected to the bottom of the spray vertical pipe and the side of the spray horizontal tube away from the desulfurization and denitrification gas inlet through a conveying device; the gas distribution pipe plate includes a tower plate with through holes, and the through holes are connected to a matching gas mixing pipe.

2. The electron beam and oxygen coordinated desulfurization and denitrification system according to claim 1 is characterized in that: A fixing part is arranged at the central axis of the gas mixing tube, and rotating parts which rotate along with the flow of smoke are arranged at intervals on the fixing part.

3. The electron beam and oxygen coordinated desulfurization and denitrification system according to claim 2 is characterized in that: Along the flow direction of the smoke, wind shielding members are arranged on both sides of the rotating shaft of the rotating member.

4. The electron beam and oxygen coordinated desulfurization and denitrification system according to claim 1 is characterized in that: The aspect ratio of the gas mixing tube is 5-15.

5. The electron beam and oxygen coordinated desulfurization and denitrification system according to claim 1 is characterized in that: The tower plate is provided with 4-8 layers of through holes from the center of the tower plate along the radial direction of the tower plate, and the through holes of each layer are arranged in a circular array, wherein the first layer of through holes is a through hole located in the center of the tower plate.

6. The electron beam and oxygen coordinated desulfurization and denitrification system according to claim 1, characterized in that: The number of the air distribution pipe plates is 2-6.

7. The electron beam and oxygen coordinated desulfurization and denitrification system according to claim 1 is characterized in that: The number of the air distribution pipe plates is 3.

8. The electron beam and oxygen coordinated desulfurization and denitrification system according to claim 1, characterized in that: The spray cross pipe is provided with 4-10 layers of nozzles along its axial direction, and each layer of nozzles includes 3-6 nozzles evenly arranged along the radial direction of the spray cross pipe.

9. The electron beam and oxygen coordinated desulfurization and denitrification system according to claim 1, characterized in that: The spray vertical pipe is provided with 4-10 layers of nozzles along its axial direction, and each layer of nozzles includes 3-6 nozzles evenly arranged along the radial direction of the spray vertical pipe.

10. A method for desulfurization and denitrification using the electron beam and oxygen coordinated desulfurization and denitrification system as described in any one of claims 1 to 9, characterized in that: The method comprises the following steps: (1) After dust removal and cooling, the flue gas is mixed with ammonia to form ammonia mixed gas; (2) mixing oxygen with the ammonia obtained in step (1), and subjecting the obtained mixed gas to electron beam irradiation reaction to obtain desulfurized and denitrified gas; (3) Using an absorption liquid to spray and absorb the desulfurized and denitrified gas obtained in step (2) to obtain purified gas and absorbed liquid.

11. The method according to claim 10, characterized in that The temperature of the flue gas after dust removal and cooling in step (1) is 50-70°C and the relative humidity is 60-80%.

12. The method according to claim 10, characterized in that The flow rate of the flue gas in step (1) is 200000-300000Nm 3 / h.

13. The method according to claim 10, characterized in that The mass concentration of SO2 in the flue gas in step (1) is 500-800 mg / Nm 3 , the mass concentration of nitrogen oxides ≤300mg / Nm 3 .

14. The method according to claim 10, characterized in that The ratio of the ammonia gas to the total molar amount of SO2 and nitrogen oxides in the flue gas in step (1) is (1-1.5):

1.

15. The method according to claim 10, characterized in that The molar ratio of the oxygen in step (2) to the ammonia in step (1) is (0.6-1.5):

1.

16. The method according to claim 10, characterized in that The temperature of the electron beam irradiation in step (2) is 50-70°C.

17. The method according to claim 10, characterized in that The time for the mixed gas to undergo electron beam irradiation reaction in step (2) is 0.5-1s.

18. The method according to claim 10, characterized in that The absorption liquid in step (3) is water and / or aqueous ammonia.

19. The method according to claim 10, characterized in that The method comprises the following steps: (1) Flow rate is 200000-300000Nm 3 / h The flue gas is mixed with ammonia after dust removal and cooling. The temperature of the flue gas after dust removal and cooling is 50-70℃, and the relative humidity is 60-80%, forming an ammonia mixed gas; the mass concentration of SO2 in the flue gas is 500-800mg / Nm 3 , the mass concentration of nitrogen oxides ≤300mg / Nm 3 ; The ratio of ammonia to the total molar amount of SO2 and nitrogen oxides in the flue gas is (1-1.5):1 (2) mixing oxygen and the ammonia obtained in step (1) in a molar ratio of (0.6-1.5):1, subjecting the obtained mixed gas to electron beam irradiation reaction at 50-70° C. for 0.5-1 s to obtain desulfurized and denitrified gas; (3) Using an absorption liquid to spray and absorb the desulfurized and denitrified gas obtained in step (2) to obtain purified gas and absorbed liquid; the absorption liquid is water and / or aqueous ammonia.

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