Device and method for synchronously removing nitrogen oxides and chlorine-containing organic matters in flue gas

Abstract

The invention discloses a device and a method for synchronously removing nitrogen oxides and chlorine-containing organic matters in flue gas. The device is composed of a heat exchange dehydrator, a DBD plasma reactor and a bag-type dust collector, the method comprises the steps of flue gas pretreatment, synchronous removal of chlorine-containing organic matters and nitrogen oxides and removal of reaction byproducts. According to the invention, a DBD plasma reactor is adopted, and chlorine-containing organic matters and nitrogen oxides are synchronously removed by using a dielectric barrier discharge low-temperature plasma catalysis technology. The defects that in traditional SNCR and SCR denitration, a catalyst is prone to poisoning, a reaction temperature window is narrow, ammonia is excessively sprayed, ammonia escapes and the like are overcome, the problem that the cost is high when chlorine-containing organic matter is removed through activated carbon is solved, and the DBD plasma reactor is higher than corona discharge and other discharge modes in the discharge space, density, electron energy and discharge efficiency; the device has the advantages of being simple in structure, long in service life, high in safety and convenient to use.

Description

Technical Field

[0001] The invention relates to the technical field of environmental protection, and in particular to a device and method for synchronously removing nitrogen oxides and chlorine-containing organic matter from flue gas. Background Art

[0002] CVOCs are a class of organic substances with one or more Cl atoms. They are relatively stable and difficult to degrade in nature. Most of them have certain carcinogenic potential, so they are difficult to decompose and have persistent pollution. When chlorine-containing organic matter is mixed into the waste incineration process, chlorobenzene is easily generated through chlorination reaction and converted into polychlorinated biphenyls (PCBs) under certain temperature and catalysis. Under 510-820℃, polychlorinated biphenyls will further react to generate more toxic dioxins (PCDD / Fs) substances. Since combustion air is required in the process of waste incineration, when the combustion temperature reaches 800-1000℃, NO x It will also be produced at the same time, causing CVOCs and NO to be produced in the flue gas at the same time x Two types of pollutants.

[0003] In recent years, as the incineration rate and scale of urban domestic waste have continued to increase and expand, NO in waste incineration flue gas has x The emission standards for pollutants and dioxins have also been significantly increased accordingly.

[0004] For nitrogen oxides in flue gas, the main methods are SNCR (selective non-catalytic reduction) and SCR (selective catalytic reduction). Among them, the SNCR process mainly sprays reducing substances such as urea or ammonia in the furnace. The denitrification efficiency is not high, the temperature and reaction space requirements are high, and the application range is limited. The SCR denitrification process uses a catalyst to reduce nitrogen oxides in flue gas. Although the denitrification efficiency is high, reducing gases such as ammonia must still be sprayed. The total investment cost, operating cost, and maintenance cost are high. In addition, there are many implementation cases of ozone denitrification processes. For example, patent CN201821177083.1 discloses an ozone denitrification device. Ozone denitrification uses an ozone generator to generate ozone. Ozone has strong oxidizing properties and oxidizes nitrogen oxides into nitric acid and nitrites. The process has high energy consumption, and ozone is easily decomposed when exposed to high temperatures, so the utilization rate is low, wastewater treatment is difficult, and it is difficult to promote on a large scale.

[0005] For chlorinated organic dioxins in flue gas, physical methods are currently widely used. One method is to avoid the temperature window for synthesizing dioxins by rapid cooling of flue gas. For example, patent CN202210044362.5 discloses a low-temperature treatment system for incineration tail gas, which controls the flue gas cooling temperature at 400 degrees, thereby reducing the resynthesis of dioxins. Another method is to spray activated carbon powder for adsorption and filtration. For example, patent CN202110365464.2 discloses a method for treating chlorinated organic waste gas, which mainly removes dioxins, a by-product of incineration, by spraying activated carbon powder.

[0006] The existing incineration flue gas treatment methods and processes, in addition to meeting the local waste incineration flue gas emission standards, lack new methods and new devices with high denitrification efficiency, economy and reliability to cope with more stringent emission standards in the future. The existing problems are:

[0007] 1) In order to improve the denitrification efficiency, the SCR process is generally added to the flue gas end. This method can further improve the denitrification efficiency to a certain extent, but the SCR catalyst requires a certain reaction temperature. When using a low-temperature SCR catalyst, the flue gas temperature must also be increased from the exhaust temperature of 140°C to about 280-350°C, so it is necessary to increase some energy consumption and control is complicated. In addition, due to the complex source of garbage, there is a lot of water and harmful substances in the incineration process, which is easy to poison the catalyst and make it ineffective. In addition, the SCR catalyst also needs to add an ammonia injection link, which inevitably leads to a certain amount of ammonia escape, increasing the control cost.

[0008] 2) In order to improve the removal efficiency of chlorinated organic matter, especially dioxins, the method of increasing the amount of activated carbon injection is generally adopted. Although activated carbon overspray can generally improve the adsorption efficiency of chlorinated organic matter and dioxins, it also comes with high operating costs. In addition, activated carbon is considered hazardous waste after replacement, and still requires considerable disposal costs and storage and transportation costs.

[0009] In order to meet higher emission requirements and find economical and efficient methods, it is necessary to develop a new device and method for the simultaneous removal of nitrogen oxides and chlorine-containing organic matter to address the shortcomings of the existing SCR denitrification method and the high operating costs of the quenching process and activated carbon. Summary of the invention

[0010] The purpose of the present invention is to provide a device and method for synchronously removing nitrogen oxides and chlorine-containing organic matter from flue gas in view of the deficiencies of the prior art. The device of the present invention is composed of a heat exchange dehydrator, a DBD plasma reactor and a bag filter; the method of the present invention includes flue gas pretreatment, synchronous removal of chlorine-containing organic matter and nitrogen oxides and removal of reaction by-products; the present invention adopts a DBD plasma reactor and utilizes dielectric barrier discharge low-temperature plasma catalytic technology to synchronously remove nitrogen oxides and chlorine-containing organic matter. The present invention overcomes the drawbacks of easy poisoning of catalysts, narrow reaction temperature window, overspray of ammonia and ammonia escape in traditional SNCR and SCR denitrification, and solves the high cost problem of activated carbon removal of chlorine-containing organic matter. The DBD plasma reaction device of the present invention is higher than corona discharge and other discharge methods in discharge space, density, electron energy and discharge efficiency; the present invention has the advantages of simple structure, long equipment life, high safety and easy use.

[0011] The specific technical solution for achieving the purpose of the present invention is:

[0012] A device for simultaneously removing nitrogen oxides and chlorine-containing organic matter from flue gas, which features include a heat exchange dehumidifier, a DBD plasma reactor and a bag filter;

[0013] The heat exchange dehumidifier is composed of a first heat exchanger, a second heat exchanger, an oil pump and a cooling tower;

[0014] The first heat exchanger is provided with a flue gas channel and a heat transfer medium channel, wherein the flue gas channel is provided with a first flue gas inlet, a first flue gas outlet and a drain hole, and the heat transfer medium channel is provided with a first heat transfer oil inlet and a first heat transfer oil outlet;

[0015] The second heat exchanger is provided with a flue gas channel and a heat transfer medium channel, wherein the flue gas channel is provided with a second flue gas inlet and a second flue gas outlet, and the heat transfer medium channel is provided with a second heat transfer oil inlet and a second heat transfer oil outlet;

[0016] The first flue gas outlet of the first heat exchanger is connected to the second flue gas inlet of the second heat exchanger;

[0017] The first heat transfer oil outlet of the first heat exchanger is connected to the second heat transfer oil inlet of the second heat exchanger;

[0018] The outlet of the oil pump is connected to the first heat transfer oil inlet of the first heat exchanger, and the inlet of the oil pump is connected to the outlet of the cooling tower;

[0019] The inlet of the cooling tower is connected to the second heat transfer oil outlet of the second heat exchanger;

[0020] The DBD plasma reactor is composed of a DBD plasma reaction chamber, a DBD plasma reactor inlet, a DBD plasma reactor outlet, a high-frequency power supply, a heat dissipation positive electrode sheet and a heat dissipation negative electrode sheet;

[0021] The DBD plasma reactor inlet and the DBD plasma reactor outlet are respectively connected to two ends of the DBD plasma reaction chamber;

[0022] The heat dissipation positive electrode sheet and the heat dissipation negative electrode sheet are respectively arranged on the upper and lower surfaces of the DBD plasma reaction chamber, and the high-frequency power supply is electrically connected to the heat dissipation positive electrode sheet and the heat dissipation negative electrode sheet;

[0023] The bag dust collector is composed of a filter cartridge, an air compressor and a high temperature resistant blower;

[0024] The filter cartridge is provided with a dust removal inlet, a dust removal outlet and a dust discharge port, and a back-blowing nozzle is provided inside the filter cartridge;

[0025] The high temperature resistant fan is connected to the dust removal outlet, and the air compressor is connected to the back-blowing nozzle;

[0026] The second flue gas outlet of the second heat exchanger on the heat exchange dehydrator is connected to the DBD plasma reactor inlet of the DBD plasma reactor through a flue gas pipeline, and the DBD plasma reactor outlet of the DBD plasma reactor is connected to the dust removal inlet of the bag filter through a flue gas pipeline.

[0027] The DBD plasma reactor is also called a dielectric barrier discharge plasma reactor; a flat channel is arranged in the DBD plasma reaction chamber of the DBD plasma reactor, a plurality of through holes in a row are arranged on the DBD plasma reactor inlet and the DBD plasma reactor outlet, and the plurality of through holes on the DBD plasma reactor inlet and the DBD plasma reactor outlet are connected with the flat channel in the DBD plasma reaction chamber.

[0028] A method for achieving simultaneous removal of nitrogen oxides and chlorine-containing organic matter in flue gas based on the above method, which is characterized by comprising the following steps;

[0029] a) Flue gas pretreatment

[0030] The heat exchange dehumidifier pre-treats the flue gas; the high temperature resistant fan introduces the flue gas from the first flue gas inlet into the flue gas channel of the first heat exchanger, and the flue gas flows from the first heat exchanger to the flue gas channel of the second heat exchanger;

[0031] Using heat transfer oil as the heat transfer medium, the heat transfer oil is introduced into the heat transfer medium channel of the first heat exchanger from the first heat transfer oil inlet under the action of the oil pump, and after heat exchange with the flue gas in the flue gas channel of the first heat exchanger, the heat transfer oil flows out from the first heat transfer oil outlet of the first heat exchanger with the residual heat, thereby cooling and removing water from the flue gas in the first heat exchanger;

[0032] The heat transfer oil enters the heat transfer medium channel of the second heat exchanger through the second heat transfer oil inlet, exchanges heat with the flue gas in the flue gas channel of the second heat exchanger, and dries the flue gas by increasing the temperature to reduce the water vapor content in the flue gas;

[0033] The heat transfer oil passing through the heat transfer medium channels of the first heat exchanger and the second heat exchanger enters the cooling tower from the second heat transfer oil outlet for cooling, and then the cooled heat transfer oil is transported from the first heat transfer oil inlet to the first heat exchanger by the oil pump, and the cycle is repeated to complete the pretreatment of the flue gas;

[0034] After the flue gas passes through the first heat exchanger, the flue gas temperature is instantly lower than the dew point, and the condensed water generated is discharged through the drainage hole;

[0035] The pretreated flue gas enters the DBD plasma reactor from the second flue gas outlet of the second heat exchanger through the DBD plasma reactor inlet;

[0036] Flue gas pretreatment can effectively reduce the impact of water vapor in waste incineration flue gas on the operation of the plasma reactor and ensure long-term stable operation.

[0037] b) Simultaneous removal of chlorine-containing organic matter and nitrogen oxides

[0038] The DBD plasma reactor uses plasma catalysis to simultaneously remove chlorine-containing organic matter and nitrogen oxides from flue gas;

[0039] The pre-treated flue gas enters the DBD plasma reaction chamber from the DBD plasma reactor inlet of the DBD plasma reactor;

[0040] Since the positive electrode of the high-frequency power supply is connected to the heat dissipation positive electrode sheet of the DBD plasma reactor, and the negative electrode of the high-frequency power supply is connected to the heat dissipation negative electrode sheet, when the voltage is 5000-12000V, a high-frequency high-voltage electric field is formed for the flue gas in the DBD plasma reaction chamber. There are a large number of high-energy electrons in the electric field. The high-energy electrons react with the molecules of chlorobenzene, dioxins, polychlorinated biphenyls, NO, NO2, H2O, and O2 in the flue gas by plasma catalysis. The DBD plasma reactor is implemented to perform plasma catalysis on the flue gas to simultaneously remove chlorine-containing organic matter and nitrogen oxides, forming reaction by-products;

[0041] c) Removal of reaction by-products

[0042] The bag filter removes the reaction by-products; the flue gas containing the reaction by-products enters the bag filter from the outlet of the DBD plasma reactor through the dust removal inlet, and the high-temperature resistant fan removes the flue gas filtered by the filter cartridge, chlorine-containing organic matter and NOx from the dust removal outlet at the same time; the air compressor is started at a fixed time, and the air compressor delivers pressurized gas to the back-blowing nozzle to blow off the dust accumulated in the filter cartridge and discharge it through the dust outlet to remove the reaction by-products.

[0043] The beneficial effects of the present invention are:

[0044] 1. The DBD plasma reactor of the present invention adopts dielectric barrier discharge, which is higher than other discharge modes such as corona discharge in discharge space, density, electron energy and discharge efficiency. The flat-plate discharge structure is simpler than the coaxial and row-type structures, and is also convenient for later replacement and maintenance.

[0045] 2. The added heat dissipation positive electrode sheet and heat dissipation negative electrode sheet are conducive to the long-term stable operation of the DBD plasma reactor. The device life is longer than the coaxial and row-type discharge methods.

[0046] 3. The electrode and the heat dissipation device are combined. Compared with other discharge structures, the electrode is easier to lead out and easier to assemble.

[0047] 4. The active free radicals generated by discharge can act on nitrogen oxides and chlorine-containing organic matter at the same time. Under the action of the catalyst, efficient and stable removal effects can be achieved at the same time, and the energy utilization rate is higher; the removal rate of low-concentration NO can reach 50%.

[0048] 5. No need to add other reducing gases such as ammonia, etc., simple structure, long equipment life and high safety; suitable for various working conditions, small equipment footprint, modular design and manufacturing, easy construction, installation and management.

[0049] 6. The device is easy to assemble, the accessories are easy to replace, and it is easy to realize large-scale industrial production.

[0050] 7. It can effectively solve the problem of ammonia escape in SNCR and SCR denitrification processes, and reduce the impact of subsequent reactions between ammonia and sulfate in the atmosphere on haze. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A schematic diagram of the structure of the invention;

[0052] Figure 2 It is a schematic diagram of the structure of a DBD plasma reactor;

[0053] Figure 3 for Figure 2 sectional view of . DETAILED DESCRIPTION

[0054] See also Figure 1 , Figure 2 , Figure 3 The device of the present invention comprises a heat exchange dehumidifier 1, a DBD plasma reactor 2 and a bag filter 3;

[0055] The heat exchange dehumidifier 1 is composed of a first heat exchanger 11, a second heat exchanger 12, an oil pump 111 and a cooling tower 112;

[0056] The first heat exchanger 11 is provided with a flue gas channel and a heat transfer medium channel, wherein the flue gas channel is provided with a first flue gas inlet 103, a first flue gas outlet 106 and a drain hole 115, and the heat transfer medium channel is provided with a first heat transfer oil inlet 109 and a first heat transfer oil outlet 104;

[0057] The second heat exchanger 12 is provided with a flue gas channel and a heat transfer medium channel, wherein the flue gas channel is provided with a second flue gas inlet 107 and a second flue gas outlet 108, and the heat transfer medium channel is provided with a second heat transfer oil inlet 110 and a second heat transfer oil outlet 105;

[0058] The first flue gas outlet 106 of the first heat exchanger 11 is connected to the second flue gas inlet 107 of the second heat exchanger 12;

[0059] The first heat transfer oil outlet 104 of the first heat exchanger 11 is connected to the second heat transfer oil inlet 110 of the second heat exchanger 12;

[0060] The outlet of the oil pump 111 is connected to the first heat transfer oil inlet 109 of the first heat exchanger 11, and the inlet of the oil pump 111 is connected to the outlet of the cooling tower 112;

[0061] The inlet of the cooling tower 112 is connected to the second heat transfer oil outlet 105 of the second heat exchanger 12;

[0062] The DBD plasma reactor 2 is composed of a DBD plasma reaction chamber 227, a DBD plasma reactor inlet 225, a DBD plasma reactor outlet 226, a high-frequency power supply 222, a heat dissipation positive electrode sheet 223 and a heat dissipation negative electrode sheet 224;

[0063] The DBD plasma reactor inlet 225 and the DBD plasma reactor outlet 226 are respectively connected to two ends of the DBD plasma reaction chamber 227;

[0064] The heat dissipation positive electrode sheet 223 and the heat dissipation negative electrode sheet 224 are respectively arranged on the upper and lower surfaces of the DBD plasma reaction chamber 227, and the high frequency power supply 222 is electrically connected to the heat dissipation positive electrode sheet 223 and the heat dissipation negative electrode sheet 224;

[0065] The bag filter 3 is composed of a filter cartridge 319, an air compressor 322 and a high temperature resistant fan 321;

[0066] The filter cartridge 319 is provided with a dust removal inlet 316, a dust removal outlet 317 and a dust discharge port 320, and a back-blowing nozzle 318 is provided inside the filter cartridge 319;

[0067] The high temperature resistant fan 321 is connected to the dust removal outlet 317, and the air compressor 322 is connected to the back-blowing nozzle 318;

[0068] The second flue gas outlet 108 of the second heat exchanger 12 on the heat exchange dehydrator 1 is connected to the DBD plasma reactor inlet 225 of the DBD plasma reactor 2 through a flue gas pipeline, and the DBD plasma reactor outlet 226 of the DBD plasma reactor 2 is connected to the dust removal inlet 316 of the bag dust collector 3 through a flue gas pipeline.

[0069] See also Figure 1 , Figure 2 , Figure 3 The DBD plasma reactor 2 of the present invention is also called a dielectric barrier discharge plasma reactor; a flat channel 228 is provided in the DBD plasma reaction chamber 227 of the DBD plasma reactor 2, and a plurality of through holes 221 in a row are provided on the DBD plasma reactor inlet 225 and the DBD plasma reactor outlet 226, and the plurality of through holes on the DBD plasma reactor inlet 225 and the DBD plasma reactor outlet 226 are connected with the flat channel 228 in the DBD plasma reaction chamber 227.

[0070] The device of the present invention works like this:

[0071] See also Figure 1 , Figure 2 , Figure 3 The flue gas passages in the first heat exchanger 11 and the second heat exchanger 12 on the heat exchange dehydrator 1 of the present invention, the DBD plasma reaction chamber 227 of the DBD plasma reactor 2 and the filter cartridge 319 of the bag filter 3 constitute the closed flue gas passage of the present invention, and the high temperature resistant fan 321 provides power for the flue gas to flow in the closed flue gas passage.

[0072] See also Figure 1 , Figure 2 , Figure 3The heat transfer medium channel, cooling tower 112 and oil pump 111 in the first heat exchanger 11 and the second heat exchanger 12 of the heat exchange dehydrator 1 of the present invention constitute a closed heat transfer medium channel of the heat exchange dehydrator 1, and the oil pump 111 provides power for the heat transfer oil; under the action of the oil pump 111, the heat transfer oil flows from the first heat exchanger 11 through the second heat exchanger 12, and enters the cooling tower 112 from the second heat transfer oil outlet 102 for cooling, and then the cooled heat transfer oil is transported back to the first heat exchanger 11 from the first heat transfer oil inlet 109 by the oil pump 111, and the cycle is repeated to perform heat exchange on the flue gas, thereby completing the pretreatment of the flue gas;

[0073] Example

[0074] Based on the device of the present invention, a method for simultaneously removing nitrogen oxides and chlorine-containing organic matter from flue gas is implemented, and the specific steps are as follows:

[0075] a) Flue gas pretreatment

[0076] See also Figure 1 , the flue gas is pre-treated by the heat exchange dehumidifier 1; the high temperature resistant fan 321 introduces the flue gas from the first flue gas inlet 103 into the flue gas channel of the first heat exchanger 11, and the flue gas flows from the first heat exchanger 11 to the flue gas channel of the second heat exchanger 12;

[0077] With heat transfer oil as the heat transfer medium, the heat transfer oil is introduced into the heat transfer medium channel of the first heat exchanger 11 from the first heat transfer oil inlet 109 under the action of the oil pump 111, and after heat exchange with the flue gas in the flue gas channel of the first heat exchanger 11, the heat transfer oil carries the residual heat and flows out from the first heat transfer oil outlet 104 of the first heat exchanger 11, thereby cooling and removing water from the flue gas in the first heat exchanger 11;

[0078] The heat transfer oil enters the heat transfer medium channel of the second heat exchanger 12 through the second heat transfer oil inlet 110, exchanges heat with the flue gas in the flue gas channel of the second heat exchanger 12, and dries the flue gas by increasing the temperature to reduce the water vapor content in the flue gas;

[0079] The heat transfer oil passing through the heat transfer medium channels of the first heat exchanger 11 and the second heat exchanger 12 enters the cooling tower 112 from the second heat transfer oil outlet 102 for cooling, and then the cooled heat transfer oil is transported from the first heat transfer oil inlet 109 to the first heat exchanger 11 by the oil pump 111, and the cycle is repeated to complete the pretreatment of the flue gas;

[0080] After the flue gas passes through the first heat exchanger 11, the flue gas temperature is instantly lower than the dew point, and the generated condensed water is discharged through the drainage hole 115;

[0081] The pre-treated flue gas enters the DBD plasma reactor 2 through the second flue gas outlet 108 of the second heat exchanger 12 and the DBD plasma reactor inlet 225;

[0082] Specifically, the incinerated flue gas first passes through the first heat exchanger 11, and performs heat exchange with the heat transfer oil entering the first heat exchanger for high-temperature flue gas, and the condensed water is enriched and removed by the first heat exchanger 11; the heat transfer oil after heat exchange enters the second heat exchanger 12 with residual heat, and the heat transfer oil after heat exchange with the flue gas again is discharged into the cooling tower 112 for cooling, and the cooled heat transfer oil enters the first heat exchanger 11 again through the oil pump 111, and repeats this process to complete the flue gas pretreatment of heat exchange and water removal;

[0083] Flue gas pretreatment can effectively reduce the impact of water vapor in waste incineration flue gas on the operation of the plasma reactor and ensure long-term stable operation.

[0084] b) Simultaneous removal of chlorine-containing organic matter and nitrogen oxides

[0085] See also Figure 1 , Figure 2 , Figure 3 , the DBD plasma reactor 2 carries out plasma catalysis on the flue gas to simultaneously remove chlorine-containing organic matter and nitrogen oxides;

[0086] The flue gas generated by the incineration of garbage, i.e. the flue gas after pretreatment, inevitably contains chlorine-containing organic substances such as chlorobenzene, polychlorinated biphenyls and dioxins, and enters the DBD plasma reaction chamber 227 from the DBD plasma reactor inlet 225 of the DBD plasma reactor 2 together with NOx;

[0087] Since the positive electrode of the high-frequency power supply 222 is connected to the heat dissipation positive electrode sheet 123 of the DBD plasma reactor 2, and the negative electrode of the high-frequency power supply 222 is connected to the heat dissipation negative electrode sheet 224, when the voltage is 5000-12000V, a high-frequency high-voltage electric field is formed for the flue gas in the DBD plasma reaction chamber 227. There are a large number of high-energy electrons in the electric field. The high-energy electrons react with molecules such as chlorobenzene, dioxins, polychlorinated biphenyls, NO, NO2, H2O, O2, etc. in the flue gas as follows:

[0088] e+H2O→e+H+OH;

[0089] e+O2→e+O+O;

[0090] O2+·O→O3;

[0091] NO+·O→NO2;

[0092] NO+OH→NO2+H2O;

[0093] NO2+O2+H2O→HNO3;

[0094] C6H5Cl+OH+·O→HCl+CH3CHO+CO2+CO+H2O (under plasma catalysis);

[0095] NOx+CO+CH3CHO→N2+CO2+H2O (under the action of plasma catalyst);

[0096] HCl+NH3→NH4Cl;

[0097] HNO3+NH3→NH4NO3;

[0098] In the coupled reaction system, these pollutants undergo dechlorination and redox reactions in the DBD plasma reactor 2. Since the bond energy of the C-Cl bond in the chlorinated organic matter is 328 kJ / mol, it is easily attacked by the high-energy electrons generated by the DBD plasma and removed. The dechlorinated chlorine atoms and the ammonia escaped from the SNCR in the flue gas further react to form ammonium chloride, and the dechlorinated chlorinated organic matter decomposes into reducing substances containing carbon and hydrogen. Similarly, under the action of plasma and catalyst, it undergoes redox reactions with NOx, a part of which is reduced to N2, and the other part of NOx is oxidized in the presence of water and OH free radicals to form HNO3, and ammonium nitrate is formed in the presence of escaped ammonia.

[0099] The DBD plasma reactor 2 is implemented to perform plasma catalysis on the flue gas to simultaneously remove chlorine-containing organic matter and nitrogen oxides to form reaction by-products.

[0100] See also Figure 1 , Figure 2 , Figure 3 In order to improve the efficiency of plasma catalysis of flue gas in the DBD plasma reactor 2, a flat channel 228 is provided in the DBD plasma reaction chamber 227 of the DBD plasma reactor 2 of the present invention, and a plurality of through holes 221 in a row are provided on the DBD plasma reactor inlet 225 and the DBD plasma reactor outlet 226, and the plurality of through holes on the DBD plasma reactor inlet 225 and the DBD plasma reactor outlet 226 are connected with the flat channel 228 in the DBD plasma reaction chamber 227.

[0101] c) Removal of reaction by-products

[0102] See also Figure 1, the bag filter 3 removes the reaction by-products; the flue gas containing the reaction by-products enters the bag filter 3 through the dust removal inlet 316 from the DBD plasma reactor outlet 226, and the high temperature resistant fan 321 removes the flue gas and chlorine-containing organic matter and NOx filtered by the filter cartridge 319 from the dust removal outlet 317 at the same time; the air compressor 322 is started at a fixed time, and the air compressor 322 delivers pressurized gas to the back-blowing nozzle 318 to blow off the dust accumulated in the filter cartridge 319 and discharge it through the dust discharge port 320, thereby removing the reaction by-products. ,

[0103] Specific implementation effects:

[0104] Flue gas oxygen content 10.3%, flue gas volume 1000m 3 / h, power 2230w, does not contain V2O5 / TiO2 catalyst.

[0105]

[0106] Oxygen content 10.2%, flue gas volume 1000m 3 / h, power 2230w, containing V2O5 / TiO2 catalyst.

[0107]

[0108] Oxygen content 11.8%, flue gas volume 1000m 3 / h, power 2230w, does not contain V2O5 / TiO2 catalyst.

[0109]

[0110] Oxygen content 11.9%, flue gas volume 1000m 3 / h, power 2230w, containing V2O5 / TiO2 catalyst.

[0111]

[0112] Detection instrument: JMS-800D high-resolution gas chromatography-high-resolution mass spectrometry

[0113] Sampler: Laoying 3030B intelligent exhaust gas sampler

[0114] Testing basis: HJ 77.2-2008

[0115]

Claims

1. A device for simultaneously removing nitrogen oxides and chlorine-containing organic matter from flue gas, characterized in that: It comprises a heat exchange dehydrator (1), a DBD plasma reactor (2) and a bag filter (3); The heat exchange dehydrator (1) is composed of a first heat exchanger (11), a second heat exchanger (12), an oil pump (111) and a cooling tower (112); The first heat exchanger (11) is provided with a smoke channel and a heat transfer medium channel, wherein the smoke channel is provided with a first smoke inlet (103), a first smoke outlet (106) and a drain hole (115), and the heat transfer medium channel is provided with a first heat transfer oil inlet (109) and a first heat transfer oil outlet (104); The second heat exchanger (12) is provided with a flue gas channel and a heat transfer medium channel, wherein the flue gas channel is provided with a second flue gas inlet (107) and a second flue gas outlet (108), and the heat transfer medium channel is provided with a second heat transfer oil inlet (110) and a second heat transfer oil outlet (105); The first flue gas outlet (106) of the first heat exchanger (11) is connected to the second flue gas inlet (107) of the second heat exchanger (12); The first heat transfer oil outlet (104) of the first heat exchanger (11) is connected to the second heat transfer oil inlet (110) of the second heat exchanger (12); The outlet of the oil pump (111) is connected to the first heat transfer oil inlet (109) of the first heat exchanger (11), and the inlet of the oil pump (111) is connected to the outlet of the cooling tower (112); The inlet of the cooling tower (112) is connected to the second heat transfer oil outlet (105) of the second heat exchanger (12); The DBD plasma reactor (2) is composed of a DBD plasma reaction chamber (227), a DBD plasma reactor inlet (225), a DBD plasma reactor outlet (226), a high-frequency power supply (222), a heat dissipation positive electrode sheet (223), and a heat dissipation negative electrode sheet (224); The DBD plasma reactor inlet (225) and the DBD plasma reactor outlet (226) are respectively connected to two ends of the DBD plasma reaction chamber (227); The heat dissipation positive electrode sheet (223) and the heat dissipation negative electrode sheet (224) are respectively arranged on the upper and lower surfaces of the DBD plasma reaction chamber (227), and the high-frequency power supply (222) is electrically connected to the heat dissipation positive electrode sheet (223) and the heat dissipation negative electrode sheet (224); The bag filter (3) is composed of a filter cartridge (319), an air compressor (322) and a high temperature resistant fan (321); The filter cartridge (319) is provided with a dust removal inlet (316), a dust removal outlet (317) and a dust discharge port (320), and a back-blowing nozzle (318) is provided inside the filter cartridge (319); The high temperature resistant fan (321) is connected to the dust removal outlet (317), and the air compressor (322) is connected to the back-blowing nozzle (318); The second flue gas outlet (108) of the second heat exchanger (12) on the heat exchange dehydrator (1) is connected to the DBD plasma reactor inlet (225) of the DBD plasma reactor (2) via a flue gas duct, and the DBD plasma reactor outlet (226) of the DBD plasma reactor (2) is connected to the dust removal inlet (316) of the bag filter (3) via a flue gas duct.

2. The device for simultaneously removing nitrogen oxides and chlorine-containing organic matter from flue gas according to claim 1 is characterized in that: A flat channel (228) is provided in the DBD plasma reaction chamber (227); a plurality of through holes (221) arranged in a row are provided on the DBD plasma reactor inlet (225) and the DBD plasma reactor outlet (226); the plurality of through holes are connected to the flat channel (228) in the DBD plasma reaction chamber (227).

3. A method for simultaneously removing nitrogen oxides and chlorine-containing organic matter from flue gas based on the device of claim 1, characterized in that: The method comprises the following steps: a) Flue gas pretreatment The heat exchange dehumidifier (1) pre-treats the flue gas; the high temperature resistant fan (321) introduces the flue gas from the first flue gas inlet (103) into the flue gas passage of the first heat exchanger (11), and the flue gas flows from the first heat exchanger (11) to the flue gas passage of the second heat exchanger (12); Using heat transfer oil as a heat transfer medium, the heat transfer oil is introduced into the heat transfer medium channel of the first heat exchanger (11) from a first heat transfer oil inlet (109) under the action of an oil pump (111), and after heat exchange with the flue gas in the flue gas channel of the first heat exchanger (11), the heat transfer oil flows out from the first heat transfer oil outlet (104) of the first heat exchanger (11) carrying residual heat, thereby cooling and removing water from the flue gas in the first heat exchanger (11); The heat transfer oil enters the heat transfer medium channel of the second heat exchanger (12) through the second heat transfer oil inlet (110), exchanges heat with the flue gas in the flue gas channel of the second heat exchanger (12), and dries the flue gas by increasing the temperature, thereby reducing the water vapor content in the flue gas; The heat transfer oil passing through the heat transfer medium channels of the first heat exchanger (11) and the second heat exchanger (12) enters the cooling tower (112) from the second heat transfer oil outlet (102) for cooling, and then the cooled heat transfer oil is transported from the first heat transfer oil inlet (109) to the first heat exchanger (11) by the oil pump (111), and the cycle is repeated to complete the pretreatment of the flue gas; After the flue gas passes through the first heat exchanger (11), the flue gas temperature is instantly lower than the dew point, and the generated condensed water is discharged through the drainage hole (115); The pre-treated flue gas enters the DBD plasma reactor (2) from the second flue gas outlet (108) of the second heat exchanger (12) through the DBD plasma reactor inlet (225); b) Simultaneous removal of chlorine-containing organic matter and nitrogen oxides The DBD plasma reactor (2) performs plasma catalysis on the flue gas to simultaneously remove chlorine-containing organic matter and nitrogen oxides; The pre-treated flue gas enters the DBD plasma reaction chamber (227) from the inlet (225) of the DBD plasma reactor (2); Since the positive electrode of the high-frequency power source (222) is connected to the heat dissipation positive electrode sheet (123) of the DBD plasma reactor (2), and the negative electrode of the high-frequency power source (222) is connected to the heat dissipation negative electrode sheet (224), when the voltage is between 5000 and 12000 V, a high-frequency high-voltage electric field is formed for the flue gas in the DBD plasma reaction chamber (227). A large number of high-energy electrons exist in the electric field. The high-energy electrons react with chlorobenzene, dioxins, polychlorinated biphenyls, NO, NO2, H2O, and O2 molecules in the flue gas through plasma catalysis, and the DBD plasma reactor (2) performs plasma catalysis on the flue gas to simultaneously remove chlorine-containing organic matter and nitrogen oxides, thereby forming reaction by-products; c) Removal of reaction by-products: The bag filter (3) removes the reaction by-products; the flue gas containing the reaction by-products enters the bag filter (3) from the outlet (226) of the DBD plasma reactor through the dust removal inlet (316); the high temperature resistant fan (321) removes the flue gas filtered by the filter cartridge (319) and the chlorine-containing organic matter and NOx from the dust removal outlet (317); the air compressor (322) is started at a fixed time, and the air compressor (322) delivers pressurized gas to the back-blowing nozzle (318) to blow off the dust accumulated in the filter cartridge (319) and discharge it through the dust discharge port (320), thereby removing the reaction by-products.

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