A tar separation and removal device and method

Abstract

The present invention relates to a tar separation and removal device, which includes a first reactor, a second reactor, and a third reactor connected in sequence. The first reactor is connected to an intake pipeline, and a first water vapor inlet is provided on the side wall of the first reactor; a second water vapor inlet is provided on the side wall of the second reactor; the first reactor includes a first housing, and at least one first plasma torch is arranged inside the first housing. The first plasma torch includes an insulating first cylinder body with openings at both the upper and lower ends. A first grounding electrode is arranged on the inner wall circumference of the first cylinder body, and a first corona electrode is arranged at the center inside the first cylinder body. The present invention also provides a method for tar separation and removal. The present invention realizes the separation, removal, and collection of tar in the waste gas through a three-stage reactor. After passing through the second reactor, 99% of the tar in the waste gas can be removed and collected. The remaining tar passes through the third reactor, where the tar is further physically adsorbed, and at the same time, a catalytic reaction occurs to further degrade the remaining tar, realizing the qualified discharge of the waste gas.

Description

Technical Field

[0001] The present invention relates to the technical field of tar treatment, and particularly relates to a tar separation and removal device and method. Background Art

[0002] China is the country with the largest population and the largest amount of solid waste generated in the world. Every year, about 10 billion tons of new solid waste is added, and the total historical stockpile is as high as 60 - 70 billion tons. China is still in the stage of rapid urbanization. The land for sanitary landfills is in short supply and it is difficult to add new ones. Due to secondary pollution reasons such as service life and leachate, many current landfills are facing the dilemma of needing to be completely closed. Solid waste, especially municipal waste, is rich in organic matter, flammable, and contains chemical energy. It contains about 10 MJ / kg of heat or a volume energy density of 15.6 - 26.8 MJ / L. It is reported that the proportion of combustible components screened out from municipal waste landfills ranges from 38% to 50%, which is a considerable heat energy resource that should be recycled. Recycling municipal waste is the future development direction of solid waste treatment.

[0003] Currently, in the prior art, there is a solution that uses an incineration process to recover heat energy for power generation. However, the incineration method produces a large amount of fly ash and dioxins, etc., which has serious secondary pollution problems, and the treatment scale is too small (<500 tons / day), and the economic value is limited.

[0004] Therefore, a pyrolysis gasification technology for organic waste has been developed. The pyrolysis gasification technology of organic waste refers to the process in which large molecules of organic components in the waste break under anaerobic or anoxic conditions, generating small molecule gases, tar, and residues. It can effectively dispose of organic matter separated from domestic waste, stockpiled waste, and mixed waste. This technology replaces the traditional incinerator with a new pyrolysis gasification system device and uses biomass high-temperature decomposition technology to convert organic matter into clean energy gas. The waste pyrolysis gasification technology not only realizes the harmlessness, reduction, and resource utilization of waste, but also effectively overcomes the problem of dioxin pollution caused by waste incineration, thus becoming a waste treatment technology with great development prospects.

[0005] One drawback of this technology is that it will produce a large amount of tar. Depending on the types of organic waste and the oxygen supply ratio, tar accounts for about 10% - 50% of the organic solid waste treatment volume. The components of tar are very complex, and the main components are polycyclic aromatic hydrocarbons such as naphthalene, anthracene, phenanthrene, and quinone. It cannot be directly used and is difficult to refine. If tar is not treated, it will condense as the temperature drops, causing problems such as blockage of the subsequent waste gas purification system device, and tar is also included in the category of hazardous solid waste in the country. In the prior art, there is a process to refine tar into fuel oil, but this process requires further hydrocracking to produce light tar. Compared with petroleum products, the quality of this oil is poor, and the heating and cracking process during the re-treatment of tar will inevitably lead to energy waste, and the economic value is very low.

[0006] Tar is both a pollutant and a hazardous solid waste, yet it is also an energy-containing fuel. It is advisable to make full use of the high calorific value contained in tar. It is a relatively simple mixture of polycyclic aromatic hydrocarbons, and the calorific value and energy it contains are much higher than those of domestic waste itself. How to collect it efficiently with low energy consumption is a major challenge in the current process.

[0007] Electrodesulfurization of tar can reduce the agglomeration of tar. However, since tar is a non-polar substance, its poor electrical conductivity is not conducive to the efficient implementation of electrodesulfurization. For example, an electric tar precipitator for industrial gas purification disclosed in the prior art CN209020578U includes an electric tar precipitator body. An international standard explosion-proof hole is opened in the upper part of the left surface of the electric tar precipitator body. Insulation boxes are arranged on the left and right sides of the top of the electric tar precipitator body. A precipitation tube bundle is installed inside the electric tar precipitator body. A corona electrode is arranged on the upper side of the precipitation tube bundle, and a precipitation electrode is arranged on the lower side of the precipitation tube bundle. An upper suspension umbrella frame is arranged above the precipitation tube bundle, and a lower suspension umbrella frame is installed below the precipitation tube bundle. A gas distributor is arranged below the weight, and gas distribution plates are arranged on both the upper and lower sides of the gas distributor. A resonance chamber is arranged outside the bottom of the electric tar precipitator body, and a sound inspection hole is opened on the outer wall of the resonance chamber.

[0008] In summary, the present invention provides a tar separation and removal device and method. Summary of the Invention

[0009] In order to solve the technical problem of low tar removal efficiency in the prior art, the present invention provides a tar separation and removal device and method. The present invention makes full use of the water vapor contained in the process of pyrolysis and gasification of domestic waste. Taking these co-existing water vapors as atomic sources, the tar components are activated under the action of an electric field to generate polar components to enhance conductivity, and they are aggregated on the corona electrode for collection, which not only purifies the tail gas but also meets the requirements of up-to-standard discharge.

[0010] To achieve the above object, the technical solution of the present invention is as follows:

[0011] A tar separation and removal device includes a first reactor, a second reactor, and a third reactor connected in sequence. The first reactor is connected to an intake pipeline for introducing waste gas containing tar. A first water vapor inlet is arranged on the side wall of the first reactor, and a first discharge port is arranged at the bottom of the first reactor. The first reactor is connected to the second reactor through a first pipeline. A second water vapor inlet is arranged on the side wall of the second reactor, and a second discharge port is arranged at the bottom of the second reactor. The second reactor is connected to the third reactor through a second pipeline. A third discharge port is arranged at the bottom of the third reactor, and a gas outlet is also arranged on the side wall of the third reactor.

[0012] The first reactor includes a first housing, and at least one first plasma torch is arranged inside the first housing. The first plasma torch includes an insulating first cylinder body with openings at both the upper and lower ends. A first grounding electrode is arranged on the inner wall circumference of the first cylinder body, and a first corona electrode is arranged at the center inside the first cylinder body.

[0013] Further, the second reactor includes a second housing, and at least one second plasma torch is arranged inside the second housing. The second plasma torch includes an insulating second cylinder body with openings at both the upper and lower ends. A second grounding electrode is arranged on the inner wall circumference of the second cylinder body, and a second corona electrode is arranged at the center inside the second cylinder body.

[0014] Furthermore, a plurality of grooves are arranged on the inner walls of the first grounding electrode and the second grounding electrode, which is beneficial to the collection of liquid tar.

[0015] Further, the third reactor includes a third housing, and at least one third plasma torch is arranged inside the third housing. The third plasma torch includes an insulating third cylinder body with openings at both the upper and lower ends. A third grounding electrode is arranged on the outer wall circumference of the third cylinder body, and a third corona electrode is arranged at the center position inside the third cylinder body; a catalyst is filled between the third corona electrode and the inner wall of the third cylinder body.

[0016] Furthermore, the catalyst includes a carrier and a coating on the surface of the carrier. The carrier is a porous particle, and its material is Al 2 O 3 、CaNaSiOAlO、3 / 4CaO1 / 4Na 2 OAl 2 O 3 .2SiO 2 or one or more of them; the coating is a metal oxide.

[0017] Further, a first sensor is arranged on the intake pipeline for detecting the tar concentration.

[0018] Furthermore, a second sensor is arranged on the first pipeline for detecting the tar concentration; the tar concentration detected by the second sensor is subtracted from the tar concentration detected by the first sensor to calculate the tar purification efficiency of the waste gas after passing through the first reactor.

[0019] Furthermore, a third sensor is arranged on the second pipeline for detecting the tar concentration; the tar concentration detected by the third sensor is subtracted from the tar concentration detected by the first sensor to calculate the tar purification efficiency of the waste gas after passing through the second reactor.

[0020] Furthermore, the gas outlet is connected to an outlet pipeline, and a fourth sensor for detecting the tar content is arranged on the outlet pipeline.

[0021] Further, the inlet end of the first pipeline is arranged near the top of the first reactor, and the outlet end of the first pipeline is arranged at the bottom of the second reactor; the inlet end of the second pipeline is arranged near the top of the second reactor, and the outlet end of the second pipeline is arranged at the bottom of the third reactor.

[0022] Further, the diameter of the first cylinder is 100 mm - 1000 mm, the diameter of the second cylinder is 100 mm - 1000 mm, and the diameter of the third cylinder is 20 mm - 500 mm.

[0023] Still further, the wall thickness of the third cylinder is 2 - 20 mm.

[0024] Further, the tar separation and removal device further includes a pyrolysis furnace, which is arranged at the front end of the first reactor, and the pyrolysis furnace is communicated with the first reactor through an intake pipeline; a material inlet is arranged above the pyrolysis furnace for feeding organic waste, a plasma torch is arranged inside the pyrolysis furnace, a reducing gas inlet is arranged on the side wall of the pyrolysis furnace, and a slag outlet is arranged at the bottom of the pyrolysis furnace;

[0025] The plasma torch includes a housing with upper and lower openings. A pyrolysis corona electrode is arranged at the center of the inner cavity of the housing. An insulating layer is wrapped on the outer surface of the pyrolysis corona electrode. The pyrolysis corona electrode is connected to an external power supply. A pyrolysis grounding electrode is arranged on the inner wall of the housing. A pyrolysis corona region is formed between the pyrolysis corona electrode and the pyrolysis grounding electrode; the region between the upper part of the plasma torch and the top wall of the pyrolysis furnace is the waste drying area.

[0026] The reducing gas is carbon dioxide, nitrogen, helium, argon, etc.

[0027] The present invention also provides a method for separating and removing tar, which is applied to the above-mentioned tar separation and removal device. The specific steps include:

[0028] S1. Pass the waste gas containing tar into the first reactor through the intake pipeline. At the same time, pass water vapor into the first reactor through the first water vapor inlet; adjust the temperature and humidity in the first reactor and the voltage and current of the first corona electrode, so that the tar is in a gaseous state in the first reactor, and an emulsification reaction occurs with water molecules. At the same time, a part of the tar molecules are attacked by the hydroxyl radicals decomposed from water molecules and degraded;

[0029] S2. The emulsified tar molecules are adsorbed onto the first grounded electrode in the first reactor, and after aggregation, they are discharged from the first discharge port. The remaining gas is introduced into the second reactor through the first pipeline. Meanwhile, water vapor is introduced into the second reactor through the second water vapor inlet. The temperature, humidity, voltage, and current of the second corona electrode in the second reactor are adjusted so that the tar is in a gaseous state in the first reactor and undergoes an emulsification reaction with water molecules. At the same time, a part of the tar molecules are attacked by the hydroxyl radicals decomposed from water molecules and degraded.

[0030] S3. The gas purified by the second reactor is introduced into the third reactor through the second pipeline. The temperature, voltage, and current of the third corona electrode in the third reactor are adjusted to further collect tar and further degrade and remove the remaining trace tar.

[0031] Furthermore, the temperature in the first reactor is 200 - 800 °C, the humidity is 100%, the diameter of the first cylinder is 100 - 1000 mm, the access voltage of the first corona electrode is 20 - 100 KV, the access current is 0.05 - 0.10 A, and the residence time of the waste gas in the first reactor is 50 - 100 s.

[0032] The temperature in the second reactor is 150 - 250 °C, the humidity is 100%, the diameter of the second cylinder is 100 - 1000 mm, the access voltage of the second corona electrode is 20 - 100 KV, the access current is 0.05 - 0.10 A, and the residence time of the waste gas in the second reactor is 50 - 100 s.

[0033] The temperature in the third reactor is 100 - 250 °C, the diameter of the third cylinder is 20 - 500 mm, the access voltage of the third corona electrode is 10 - 100 KV, the access current is 0.12 - 0.50 A, and the residence time of the waste gas in the third reactor is 1 - 25 s.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] The present invention realizes the separation, removal, and collection of tar in the waste gas through three - stage reactors, achieving the qualified discharge of the tail gas. The plasma torches in the first reactor and the second reactor both adopt the structural form of arranging corona electrodes on the inner wall of the cylinder and introducing water vapor. Under the adjustment of a certain temperature, humidity, and connection power, the water vapor decomposes into charged hydroxyl radicals and hydrogen atoms. The tar undergoes an addition reaction with the hydroxyl radicals, adding - OH groups to the tar molecules. This group has high hydrophilicity, which promotes the emulsification of tar, making it highly conductive. Under the action of corona, the tar is adsorbed onto the corona electrode, and the aggregated tar flows downward and is finally discharged and collected from the discharge port. After passing through the second reactor, 99% of the tar in the waste gas can be removed. The remaining tar passes through the third reactor, and the filler inside further physically adsorbs the tar, achieving the qualified discharge of the waste gas. Brief Description of the Drawings

[0036] Figure 1 This is a schematic structural diagram of the present invention.

[0037] Figure 2 This is a schematic cross-sectional structural diagram of the first plasma torch in the present invention.

[0038] Description of the Reference Numerals in the Drawings:

[0039] 1 - First reactor, 101 - First water vapor inlet, 102 - First discharge port, 103 - First cylinder, 104 - First grounding electrode, 105 - First corona electrode,

[0040] 2 - Second reactor, 201 - Second water vapor inlet, 202 - Second discharge port, 203 - Second cylinder, 204 - Second grounding electrode, 205 - Second corona electrode,

[0041] 3 - Third reactor, 301 - Third discharge port, 302 - Gas outlet, 303 - Third cylinder, 304 - Third grounding electrode, 305 - Third corona electrode,

[0042] 4 - Pyrolysis furnace, 401 - Pyrolysis corona electrode, 402 - Pyrolysis grounding electrode, 403 - Reducing gas inlet, 404 - Slag discharge port,

[0043] 5 - Intake pipeline, 6 - First pipeline, 7 - Second pipeline, 8 - First sensor, 9 - Second sensor, 10 - Third sensor, 11 - Fourth sensor. Detailed Embodiments

[0044] The technical solutions of the present invention will be clearly described below in conjunction with the description of the drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0045] It should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0046] As Figure 1As shown in the figure, the present invention provides a tar separation and removal device, which includes a first reactor 1, a second reactor 2, and a third reactor 3 connected in sequence. The first reactor 1 is connected to an intake pipe 5 for introducing waste gas containing tar. A first water vapor inlet 101 is provided on the side wall of the first reactor 1, and a first discharge port 102 is provided at the bottom of the first reactor 1; the first reactor 1 is connected to the second reactor 2 through a first pipe 6. A second water vapor inlet 201 is provided on the side wall of the second reactor 2, and a second discharge port 202 is provided at the bottom of the second reactor 2; the second reactor 2 is connected to the third reactor 3 through a second pipe 7. A third discharge port 301 is provided at the bottom of the third reactor 3, and a gas outlet 302 is also provided on the side wall of the third reactor 3;

[0047] The first reactor 1 includes a first housing. At least one first plasma torch is arranged inside the first housing. The first plasma torch includes an insulating first cylinder body 103 with upper and lower openings. A first grounding electrode 104 is arranged on the inner wall circumference of the first cylinder body 103, and a first corona electrode 105 is arranged at the center inside the first cylinder body 103. When there are multiple first plasma torches inside the first housing, the multiple plasma torches are arranged in an array. The diameter of the first cylinder body 103 is 100 mm - 1000 mm, and the side wall thickness of the first cylinder is 5 mm - 50 mm. The first cylinder body 103 is made of an insulating material, and the insulating material is one or more of mica, asbestos, quartz cloth, glass fiber, ceramic, alumina, and zirconia. The first grounding electrode 104 is closely attached to the first cylinder body 103.

[0048] Further, the second reactor 2 includes a second housing. At least one second plasma torch is arranged inside the second housing. The structure of the second plasma torch is the same as that of the first plasma torch. The second plasma torch includes an insulating second cylinder body 203 with upper and lower openings. A second grounding electrode 204 is arranged on the inner wall circumference of the second cylinder body 203, and a second corona electrode 205 is arranged at the center inside the second cylinder body 203.

[0049] Even further, as Figure 2 shown, a number of grooves are arranged on the inner walls of the first grounding electrode 104 and the second grounding electrode 204, which is beneficial to the collection of liquid tar and improves the collection efficiency.

[0050] Further, the third reactor 3 includes a third housing, and at least one third plasma torch is arranged inside the third housing. The third plasma torch includes an insulating third cylinder body 303 with openings at both the upper and lower ends. The diameter of the third cylinder body 303 is 20 mm - 500 mm, and the wall thickness is 2 mm - 20 mm. A third grounding electrode 304 is arranged on the outer circumferential wall of the third cylinder body 303, and a third corona electrode 305 is arranged at the central position inside the third cylinder body 303; a catalyst is filled between the third corona electrode 305 and the inner wall of the third cylinder body 303. The catalyst includes a carrier and a coating on the surface of the carrier. The carrier is a porous particle, and its material is Al 2 O 3 , CaNaSiOAlO, 3 / 4CaO1 / 4Na 2 OAl 2 O 3 .2SiO 2 or one or more of them; the coating is a metal oxide, such as an oxide of one or two elements among Ni, Mn, Zn, Co, Cu, and Fe. The metal oxide is in a nanostructure.

[0051] Further, a first sensor 8 is arranged on the intake pipe 5 for detecting the tar concentration. A second sensor 9 is arranged on the first pipe 6 for detecting the tar concentration; the tar concentration detected by the second sensor 9 minus the tar concentration detected by the first sensor 8 is used to calculate the tar purification efficiency of the waste gas after passing through the first reactor 1. A third sensor 10 is arranged on the second pipe 7 for detecting the tar concentration; the tar concentration detected by the third sensor 10 minus the tar concentration detected by the first sensor 8 is used to calculate the tar purification efficiency of the waste gas after passing through the second reactor 2. The gas outlet 302 is connected to an outlet pipe, and a fourth sensor 11 for detecting the tar content is arranged on the outlet pipe.

[0052] The purification efficiency of the waste gas after passing through the first reactor 1 should be greater than 90%, the purification efficiency after passing through the second reactor 2 should be greater than 99%, and the tar after passing through the third reactor 3 should meet the emission standard. The emission standard in this embodiment is that the tar concentration is less than 100 mg / m 3 ; Therefore, a controller can be set. The controller is connected to the first sensor 8, the second sensor 9, the third sensor 10, and the fourth sensor 11. When the purification efficiency of the tar does not meet the standard, the inlet speed of the waste gas can be adjusted, the gas purification time can be increased, or the corona electrode voltage can be increased to improve the purification efficiency. To facilitate the adjustment of the inlet speed of the waste gas, a gas flow meter is arranged on the intake pipe, and the gas flow meter is connected to the controller to control the inlet speed of the waste gas. To facilitate the control of the gas purification time, a gas flow meter is arranged on the first pipe or the second pipe, and the gas purification time is adjusted by the valve opening of the gas flow meter.

[0053] Further, the inlet end of the first pipeline 6 is arranged near the top of the first reactor 1, and the outlet end of the first pipeline 6 is arranged at the bottom of the second reactor 2; the inlet end of the second pipeline 7 is arranged near the top of the second reactor 2, and the outlet end of the second pipeline 7 is arranged at the bottom of the third reactor 3.

[0054] In other embodiments, the tar separation and removal device may further include a pyrolysis furnace 4, which is arranged at the front end of the first reactor 1 and is communicated with the first reactor 1 through an intake pipeline 5; a material inlet is arranged above the pyrolysis furnace 4 for feeding organic waste, a plasma torch is arranged inside the pyrolysis furnace 4, a reducing gas inlet 403 is arranged on the side wall of the pyrolysis furnace 4, and a slag outlet 404 is arranged at the bottom of the pyrolysis furnace 4;

[0055] The plasma torch includes a housing with upper and lower openings. A pyrolysis corona electrode 401 is arranged at the center of the inner cavity of the housing. The outer surface of the pyrolysis corona electrode 401 is wrapped with an insulating layer. The pyrolysis corona electrode 401 is connected to an external power supply. A pyrolysis ground electrode 402 is arranged on the inner wall of the housing. A pyrolysis corona region is formed between the pyrolysis corona electrode 401 and the pyrolysis ground electrode 402; the region between the upper part of the plasma torch and the top wall of the pyrolysis furnace is a waste drying area.

[0056] The reducing gas is carbon dioxide, nitrogen, helium, argon, etc.

[0057] The reducing gas enters the pyrolysis furnace 4 from the reducing gas inlet and enters the pyrolysis corona region inside the plasma torch. A power supply with a certain voltage is applied to the pyrolysis corona electrode 401 to raise the temperature of the corona region to a certain range. The organic waste releases water vapor, and the water vapor decomposes into high-energy free radicals and small molecules under the action of voltage and high temperature. The free radicals and small molecules react with the large carbon-hydrogen molecules in the waste and are cracked into combustible synthesis gases such as H 2 , CO, etc., which carry tar. The combustible synthesis gas rises to the top of the pyrolysis furnace and enters the waste drying area with a certain amount of heat. The combustible synthesis gas carrying heat contacts the input waste to evaporate the water in the waste, thereby achieving the purpose of drying the waste. The dried waste descends into the plasma torch and continues to react with the free radicals to generate combustible synthesis gas.

[0058] The present invention also provides a tar separation and removal method, which is applied to the above tar separation and removal device. The specific steps include:

[0059] S1. Pass the waste gas containing tar into the first reactor 1 through the intake pipe 5. At the same time, pass water vapor into the first reactor 1 through the first water vapor inlet 101. Adjust the temperature and humidity in the first reactor 1 and the voltage and current of the first corona electrode 105 so that the tar is in a gaseous state in the first reactor 1 and undergoes an emulsification reaction with water molecules. At the same time, a part of the tar molecules are attacked by the hydroxyl radicals decomposed from water molecules and degraded.

[0060] S2. The tar molecules with hydroxyl radicals are adsorbed on the first corona electrode 105 in the first reactor 1, aggregated and discharged from the first discharge port 102. The remaining gas is passed into the second reactor 2 through the first pipe 6. At the same time, pass water vapor into the second reactor 2 through the second water vapor inlet 201. Adjust the temperature, humidity and the voltage and current of the second corona electrode 205 in the second reactor 2 so that the tar is in a gaseous state in the first reactor 1 and undergoes an emulsification reaction with water molecules. At the same time, a part of the tar molecules are attacked by the hydroxyl radicals decomposed from water molecules and degraded.

[0061] S3. The gas purified by the second reactor 2 is passed into the third reactor 3 through the second pipe 7. Adjust the temperature in the third reactor 3 and the voltage and current of the third corona electrode 305 to further collect tar and further degrade and remove the remaining trace tar.

[0062] Furthermore, the temperature in the first reactor 1 is 200 - 800 °C, the humidity is 100%, the diameter of the first cylinder is 100 - 1000 mm, the access voltage of the first corona electrode 105 is 20 - 100 KV, the access current is 0.05 - 0.10 A, and the residence time of the waste gas in the first reactor is 50 - 100 s.

[0063] The temperature in the second reactor 2 is 150 - 250 °C, the humidity is 100%, the diameter of the second cylinder is 100 - 1000 mm, the access voltage of the second corona electrode 205 is 20 - 100 KV, the access current is 0.05 - 0.10 A, and the residence time of the waste gas in the second reactor is 50 - 100 s.

[0064] The temperature in the third reactor 3 is 100 - 250 °C, the diameter of the third cylinder is 20 - 500 mm, the access voltage of the third corona electrode 305 is 10 - 100 KV, the access current is 0.12 - 0.50 A, and the residence time of the waste gas in the third reactor is 1 - 25 s.

[0065] During the tar collection process, the water in the first reactor 1 decomposes into hydroxyl radicals ·OH and hydrogen atoms under the action of corona. Subsequently, the tar molecules combine with the hydroxyl radicals to undergo an addition reaction, causing the tar molecules to carry ·OH groups. Hydroxyl radicals have high hydrophilicity, which in turn makes the tar molecules highly conductive. Under the action of corona, the tar is adsorbed on the inner walls of the first corona electrode or the second corona electrode and accumulates downward through the grooves, and finally is discharged from the discharge port.

[0066] The saturated water vapor is in the first reactor and the second reactor, and parameters such as the access voltage, access power, and temperature of the first reactor and the second reactor are limited. The tar in the waste gas is extremely easy to undergo an emulsification reaction with water molecules, that is, the tar combines with hydroxyl radicals to undergo an addition reaction, and thus the tar has strong conductivity.

[0067] Example 1

[0068] The tar content in the waste gas is 15.5%. Two plasma torches are arranged in both the first reactor and the second reactor, and one plasma torch is arranged in the third reactor. The diameters of the first cylinder and the second cylinder are both 100 mm and the lengths are 1000 mm. The materials of the first cylinder and the second cylinder are both high-temperature resistant ceramics; the materials of the first corona electrode and the second corona electrode are both copper layers; the materials of the first grounding electrode and the second grounding electrode are both stainless steel meshes. The diameter of the third cylinder is 20 mm and the length is 500 mm. The material of the third cylinder is quartz with a wall thickness of 3 mm. The material of the third corona electrode is a Ф5 mm copper rod, and the material of the third grounding electrode is a 3 mm thick stainless steel mesh. The catalyst in the third reactor is Ф4 mm porous particles, and its carrier is Al 2 O 3 , and the coating is Co 2 O 3 . The residence time of the tar-containing gas in the first reactor and the second reactor is 50 s, and the residence time in the third reactor is 1.0 s. The control parameters are shown in Table 1.

[0069] Table 1 Control parameters in Example 1

[0070]

[0071]

[0072] Example 2

[0073] The tar content in the waste gas is 15.5%. Two plasma torches are installed in both the first reactor and the second reactor, and one plasma torch is installed in the third reactor. The diameters of the first cylinder and the second cylinder are both 1000 mm and the lengths are 5000 mm. The materials of the first cylinder and the second cylinder are both high-temperature resistant ceramics; the materials of the first corona electrode and the second corona electrode are both copper layers; the materials of the first grounding electrode and the second grounding electrode are both stainless steel meshes. The diameter of the third cylinder is 500 mm and the length is 5000 mm. The material of the third cylinder is quartz with a wall thickness of 10 mm. The material of the third corona electrode is a 10-mm copper rod, and the material of the third grounding electrode is a 10-mm thick stainless steel mesh. The catalyst in the third reactor is a porous particle with a diameter of Ф5 mm, and its carrier is Al 2 O 3 , and the coating is Co 2 O 3 . The residence time of the tar-containing gas in the first reactor and the second reactor is 100 s, and the residence time in the third reactor is 25 s. The control parameters are shown in Table 2.

[0074] Table 2 Control Parameters in Example 2

[0075]

[0076] Example 3

[0077] The tar content in the waste gas is 15.5%. Two plasma torches are installed in both the first reactor and the second reactor, and one plasma torch is installed in the third reactor. The diameters of the first cylinder and the second cylinder are 300 mm and the lengths are 1 m. The materials of the first cylinder and the second cylinder are both high-temperature resistant ceramics; the materials of the first corona electrode and the second corona electrode are both copper layers; the materials of the first grounding electrode and the second grounding electrode are both stainless steel meshes. The diameter of the third cylinder is 100 mm and the length is 1000 mm. The material of the third cylinder is quartz with a wall thickness of 6 mm. The material of the third corona electrode is a Ф10-mm copper rod, and the material of the third grounding electrode is a 5-mm thick stainless steel mesh. The catalyst in the third reactor is a porous particle with a diameter of Ф4 mm, and its carrier is Al 2 O 3 , and the coating is Co 2 O 3 . The residence time of the tar-containing gas in the first reactor and the second reactor is 100 s, and the residence time in the third reactor is 12 s. The control parameters are shown in Table 3.

[0078] Table 3 Control Parameters in Example 3

[0079]

[0080]

[0081] Comparative Example 1

[0082] The tar content in the waste gas is 15.5%. Two plasma torches are installed in both the first reactor and the second reactor, and one plasma torch is installed in the third reactor. The diameters of the first cylinder and the second cylinder are both 100 mm and the lengths are both 1000 mm. The materials of the first cylinder and the second cylinder are both high-temperature resistant ceramics; the materials of the first corona electrode and the second corona electrode are both copper layers; the materials of the first grounding electrode and the second grounding electrode are both stainless steel meshes. The diameter of the third cylinder is 100 mm and the length is 1000 mm. The material of the third cylinder is quartz with a wall thickness of 5 mm. The material of the third corona electrode is a copper rod with a diameter of Ф10 mm, and the material of the third grounding electrode is a stainless steel mesh with a thickness of 5 mm. The catalyst in the third reactor is porous particles with a diameter of Ф10 mm, and its carrier is Al 2 O 3 , and the coating is Co 2 O 3 . The residence time of the tar-containing gas in the first reactor and the second reactor is 50 s, and the residence time in the third reactor is 50 s. The control parameters are shown in Table 4.

[0083] Table 4 Control Parameters in Comparative Example 1

[0084]

[0085] Comparative Example 2

[0086] The tar content in the waste gas is 15.5%. Two plasma torches are installed in both the first reactor and the second reactor, and one plasma torch is installed in the third reactor. The diameters of the first cylinder and the second cylinder are 600 mm and the lengths are 100 mm. The materials of the first cylinder and the second cylinder are both high-temperature resistant ceramics; the materials of the first corona electrode and the second corona electrode are both copper layers; the materials of the first grounding electrode and the second grounding electrode are both stainless steel meshes. The diameter of the third cylinder is 100 mm and the length is 500 mm. The material of the third cylinder is quartz with a wall thickness of 5 mm. The material of the third corona electrode is a copper rod with a diameter of Ф8 mm, and the material of the third grounding electrode is a stainless steel mesh with a thickness of 5 mm. The catalyst in the third reactor is porous particles with a diameter of Ф4 mm, and its carrier is Al 2 O 3 , and the coating is Co 2 O 3 . The residence time of the tar-containing gas in the first reactor and the second reactor is 30 s, and the residence time in the third reactor is 0.5 s. The control parameters are shown in Table 5.

[0087] Table 5 Control Parameters in Comparative Example 2

[0088]

[0089] The results of the tar purification efficiency of the examples and comparative examples are shown in Table 6.

[0090] Table 6 Tar purification efficiency of the examples and comparative examples

[0091]

[0092] The above specific embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A tar separation and removal device, characterized in that, it includes a first reactor, a second reactor, and a third reactor connected in sequence. The first reactor is connected to an intake pipe and is used for introducing waste gas containing tar. A first water vapor inlet is arranged on the side wall of the first reactor, and a first discharge port is arranged at the bottom of the first reactor; the first reactor and the second reactor are connected through a first pipe. A second water vapor inlet is arranged on the side wall of the second reactor, and a second discharge port is arranged at the bottom of the second reactor; the second reactor and the third reactor are connected through a second pipe. A third discharge port is arranged at the bottom of the third reactor, and a gas outlet is also arranged on the side wall of the third reactor; The first reactor includes a first housing, and at least one first plasma torch is arranged inside the first housing. The first plasma torch includes an insulating first cylinder body with upper and lower openings. A first grounding electrode is arranged on the inner wall circumference of the first cylinder body, and a first corona electrode is arranged at the center inside the first cylinder body; A tar separation and removal method applied to the tar separation and removal device described above includes: S1. Introduce the waste gas containing tar into the first reactor through the intake pipe. At the same time, introduce water vapor into the first reactor through the first water vapor inlet; Adjust the temperature and humidity inside the first reactor and the voltage and current of the first corona electrode so that the tar is in a gaseous state in the first reactor and undergoes an emulsification reaction with water molecules. At the same time, a part of the tar molecules are attacked by the hydroxyl radicals decomposed from the water molecules and degraded; S2. The emulsified tar molecules are adsorbed on the first grounding electrode inside the first reactor, aggregated and discharged from the first discharge port. The remaining gas is introduced into the second reactor through the first pipe. At the same time, introduce water vapor into the second reactor through the second water vapor inlet; adjust the temperature, humidity, and the voltage and current of the second corona electrode inside the second reactor so that the tar is in a gaseous state in the first reactor and undergoes an emulsification reaction with water molecules. At the same time, a part of the tar molecules are attacked by the hydroxyl radicals decomposed from the water molecules and degraded; S3. The gas purified by the second reactor is introduced into the third reactor through the second pipe. Adjust the temperature inside the third reactor and the voltage and current of the third corona electrode to further collect tar and further degrade and remove the remaining trace tar.

2. The tar separation and removal device according to claim 1, characterized in that, the second reactor includes a second housing, and at least one second plasma torch is arranged inside the second housing. The second plasma torch includes an insulating second cylinder body with upper and lower openings. A second grounding electrode is arranged on the inner wall circumference of the second cylinder body, and a second corona electrode is arranged at the center inside the second cylinder body.

3. The tar separation and removal device according to claim 2, characterized in that, several grooves are arranged on the inner walls of the first grounding electrode and the second grounding electrode, which is beneficial to the collection of liquid tar.

4. The tar separation and removal device according to claim 1, characterized in that, The third reactor includes a third housing, and at least one third plasma torch is arranged inside the third housing. The third plasma torch includes an insulating third cylinder body with upper and lower openings. A third grounding electrode is arranged on the outer circumferential wall of the third cylinder body, and a third corona electrode is arranged at the central position inside the third cylinder body. A catalyst is filled between the third corona electrode and the inner wall of the third cylinder body.

5. The tar separation and removal device according to claim 4, wherein, The catalyst includes a carrier and a coating on the surface of the carrier. The carrier is a porous particle, and its material is Al 2 O 3 , CaNaSiOAlO, 3 / 4CaO1 / 4Na 2 OAl 2 O 3 .2SiO 2 or one or more of them; the coating is a metal oxide.

6. The tar separation and removal device according to claim 1, wherein, A first sensor is arranged on the intake pipe for detecting the tar concentration; A second sensor is arranged on the first pipe for detecting the tar concentration. The tar purification efficiency of the waste gas after passing through the first reactor is calculated by subtracting the tar concentration detected by the first sensor from the tar concentration detected by the second sensor; A third sensor is arranged on the second pipe for detecting the tar concentration. The tar purification efficiency of the waste gas after passing through the second reactor is calculated by subtracting the tar concentration detected by the first sensor from the tar concentration detected by the third sensor; The gas outlet is connected to an outlet pipe, and a fourth sensor for detecting the tar content is arranged on the outlet pipe.

7. The tar separation and removal device according to claim 1, wherein, The inlet end of the first pipe is arranged near the top of the first reactor, and the outlet end of the first pipe is arranged at the bottom of the second reactor; the inlet end of the second pipe is arranged near the top of the second reactor, and the outlet end of the second pipe is arranged at the bottom of the third reactor.

8. The tar separation and removal device according to claim 1, wherein, The tar separation and removal device further includes a pyrolysis furnace, which is arranged at the front end of the first reactor and is communicated with the first reactor through an intake pipe; a material inlet is arranged above the pyrolysis furnace for feeding organic waste, a plasma torch is arranged inside the pyrolysis furnace, a reducing gas inlet is arranged on the side wall of the pyrolysis furnace, and a slag outlet is arranged at the bottom of the pyrolysis furnace; The plasma torch includes a housing with upper and lower openings. A pyrolysis corona electrode is arranged at the center of the inner cavity of the housing. An insulating layer is wrapped on the outer surface of the pyrolysis corona electrode. The pyrolysis corona electrode is connected to an external power supply. A pyrolysis grounding electrode is arranged on the inner wall of the housing. A pyrolysis corona region is formed between the pyrolysis corona electrode and the pyrolysis grounding electrode; the region between the upper part of the plasma torch and the top wall of the pyrolysis furnace is a waste drying area.

9. The tar separation and removal device according to claim 1, wherein, The temperature in the first reactor is 200 - 800 °C, the humidity is 100%, the diameter of the first cylinder body is 100 - 1000 mm, the access voltage of the first corona electrode is 20 - 100 KV, the access current is 0.05 - 0.10 A, and the residence time of the waste gas in the first reactor is 50 - 100 s; The temperature in the second reactor is 150 - 250 °C, the humidity is 100%, the diameter of the second cylinder body is 100 - 1000 mm, the access voltage of the second corona electrode is 20 - 100 KV, the access current is 0.05 - 0.10 A, and the residence time of the waste gas in the second reactor is 50 - 100 s; The temperature in the third reactor is 100 - 250 °C, the diameter of the third cylinder is 20 - 500 mm, the access voltage of the third corona electrode is 10 - 100 KV, the access current is 0.12 - 0.50 A, and the residence time of the waste gas in the third reactor is 1 - 25 s.

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