VOCs treatment device for low-temperature coal pyrolysis

Abstract

The utility model relates to the field of VOCs waste gas treatment, and particularly discloses a VOCs treatment device for low-temperature coal pyrolysis. The VOCs treatment device for low-temperature coal pyrolysis comprises a tank field tail gas collecting system, a submerged pool tail gas collecting system, a furnace top tail gas collecting system, a coke discharging pit tail gas collecting system, a sintered plate dust remover, a spray demisting tower, a gas-liquid separation tower, a combustion system and a wastewater treatment device. Corresponding collection and treatment measures are provided for different VOCs emission sources such as a tank area, a submerged pool, a furnace top and a coke discharging pit, and it is ensured that the whole system can comprehensively cover and effectively treat VOCs.

Description

Technical Field

[0001] The present application relates to the field of VOCs waste gas treatment, and in particular to a VOCs treatment device for low-temperature pyrolysis of coal. Background Art

[0002] The low-temperature coal pyrolysis device is a complex system that includes multiple processes such as coal preparation, carbonization, and purification. Among them, the carbonization section, as a key part of the entire process, involves multiple production links such as wet quenching, tar and ammonia separation, and tar storage tanks. These links work together to achieve low-temperature pyrolysis of coal and generate corresponding chemical products and by-products.

[0003] During the wet quenching process, a large amount of volatile organic gases will be generated when high-temperature blue coke comes into contact with quenching water. Similarly, tar-ammonia separation devices, tar storage tanks and other facilities will also emit tail gas during operation. These tail gases mainly contain non-methane total hydrocarbons, tar droplets, water vapor, dust and other volatile organic gases (VOCs). These unorganized VOCs emissions not only pollute the environment, but may also have a negative impact on the occupational health of employees. Summary of the invention

[0004] In order to achieve "zero" emission of VOCs during low-temperature pyrolysis of coal, the present application provides a VOCs control device for low-temperature pyrolysis of coal.

[0005] The VOCs treatment device for low-temperature pyrolysis of coal provided in this application adopts the following technical solution:

[0006] In the first aspect, the present application provides a VOCs treatment device for low-temperature pyrolysis of coal, which adopts the following technical solution:

[0007] A VOCs treatment device for low-temperature pyrolysis of coal, comprising:

[0008] The tail gas collection system includes a tank area tail gas collection system, a submerged pool tail gas collection system, a furnace top tail gas collection system and a coke outlet pit tail gas collection system; the tank area tail gas collection system, the submerged pool tail gas collection system, the furnace top tail gas collection system and the coke outlet pit tail gas collection system all include a gas collection hood, a breathing valve and a tail gas collection pipeline located in the collection area, the breathing valve is connected through the tail gas collection pipeline, and the tail gas collection pipelines of the furnace top tail gas collection system and the coke outlet pit tail gas collection system are also connected to a pipeline dust collector;

[0009] The sintering plate dust collector has an inlet connected to the tail gas collection pipeline of the furnace top tail gas collection system and the coke pit tail gas collection system. The sintering plate dust collector is used for preliminary dust removal and purification of the collected tail gas;

[0010] The spray demisting tower has an inlet connected to the tail gas collection system of the tank area, the tail gas collection pipeline of the submerged pool tail gas collection system, and the outlet of the sintered plate dust collector. The spray demisting tower is provided with a spray device for washing, cooling and cooling the collected tail gas;

[0011] The gas-liquid separation tower has an inlet connected to the outlet of the spray demister tower. The gas-liquid separation tower is equipped with a high-efficiency blade demister device for separating liquid droplets in the tail gas;

[0012] A combustion system connected to the outlet of the high-efficiency gas-liquid separation tower, the combustion system comprising a direct combustion device and a catalytic combustion device, the catalytic combustion device comprising an activated carbon adsorption box for intercepting volatile organic substances;

[0013] A wastewater treatment plant is used to treat the condensate collected from each treatment plant.

[0014] Optionally, an energy recovery system is also included, which is used to recover the heat energy generated in the combustion system and use it for preheating or other heat energy requirements of the coal low-temperature pyrolysis process. The energy recovery system includes a heat exchanger, which is connected to the exhaust port of the combustion system.

[0015] Optionally, the spray demisting tower adopts a high tower design to reduce the floor space, and its bottom serves as a circulation pool, and the washing circulating water is transported to the spray device in the tower through a circulating water pump.

[0016] Optionally, the high-efficiency blade defogger device includes a plurality of guide plates, the surface of the guide plates is provided with wavy guide grooves, the through direction of the guide grooves is perpendicular to the flow direction of the gas along the guide plates, a plurality of baffles evenly spaced and fixedly arranged on both sides of the guide plates are provided with bent baffles integrally provided at both ends of the baffles, the baffles at both ends of the baffles are arranged in opposite directions, and the baffles are S-shaped as a whole.

[0017] Optionally, the internal filter element of the sintered plate dust collector is a sintered plate, and a plurality of the sintered plates are provided. The plurality of sintered plates are vertically arranged in parallel inside the sintered plate dust collector, and the sintered plates are corrugated sintered plates.

[0018] Optionally, the surface of the sintered plate is coated with a PTFE coating.

[0019] Optionally, an activated carbon bed is provided in the activated carbon adsorption box. After the activated carbon bed reaches the adsorption saturation state, it is burned under low-temperature flameless conditions through the action of precious metal catalysts such as platinum and palladium with ceramic as the carrier, so as to oxidize and decompose the trapped volatile organic substances into CO2 and H2O.

[0020] In summary, the present application includes at least one of the following beneficial technical effects:

[0021] 1. Since the VOCs treatment device for low-temperature coal pyrolysis provided by the present application is flexibly designed, it can be split or combined according to actual working conditions and needs. This means that whether in a large-scale low-temperature coal pyrolysis plant or in a small laboratory scale, suitable process sections and equipment can be selected for application according to specific circumstances. In addition, for different VOCs emission sources, such as tank areas, submerged pools, furnace tops, and coke pits, the present invention provides corresponding collection and treatment measures to ensure that the entire system can fully cover and effectively treat VOCs;

[0022] 2. The process equipment such as sintered plate dust collector, spray demisting tower and high-efficiency gas-liquid separation tower in this application all adopt advanced technology and materials, which can efficiently capture dust, tar droplets and volatile organic compounds in tail gas. In particular, the sintered plate dust collector, with its micron-level filter aperture and special surface coating, makes the capture rate reach more than 99%. In addition, through direct combustion and catalytic combustion devices to thoroughly decompose VOCs, "zero emission" of VOCs is achieved, effectively protecting the environment;

[0023] 3. The process equipment in this application is advanced in selection, not only with efficient processing capacity, but also with a high degree of automation, reducing the reliance on manual operation and the risk of misoperation. For example, the sintering plate dust collector and the spray mist removal tower are equipped with automatic control systems, which can automatically adjust the operating status according to the exhaust gas composition and processing requirements. In addition, the setting of the safety interlock device also ensures the safety of the entire system during operation, further improving the reliability of operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the overall structure of a VOCs treatment device for low-temperature coal pyrolysis according to an embodiment of the present application;

[0025] Figure 2 This is a schematic diagram of the structure of a sintering plate of a VOCs treatment device for low-temperature pyrolysis of coal according to an embodiment of the present application;

[0026] Figure 3 It is a structural schematic diagram of a blade defogger device of a VOCs treatment device for low-temperature pyrolysis of coal in an embodiment of the present application.

[0027] Explanation of the reference numerals: 1. exhaust gas collection system; 11. gas collecting hood; 12. breathing valve; 13. exhaust gas collection pipeline; 14. pipeline dust collector; 2. sintering plate dust collector; 21. sintering plate; 211. coalescing tank; 3. spray defogger; 31. first induced draft fan; 32. circulating water pump; 4. gas-liquid separation tower; 41. high-efficiency blade defogger; 411. guide plate; 4111. guide groove; 412. baffle; 4121. flow blocking part; 5. combustion system; 51. direct combustion device; 52. catalytic combustion device; 53. second induced draft fan; 6. energy recovery system; 61. heat exchanger; 7. wastewater treatment device; 71. condensate collection pipeline. DETAILED DESCRIPTION

[0028] The following is combined with Figure 1-3 This application is described in further detail.

[0029] The present application embodiment discloses a VOCs treatment device for low-temperature pyrolysis of coal. Figure 1 A VOCs treatment device for low-temperature pyrolysis of coal includes a tail gas collection system 1, a sintering plate dust collector 2, a spray demisting tower 3, a gas-liquid separation tower 4, a combustion system 5, an energy recovery system 6 and a wastewater treatment device 7.

[0030] Reference Figure 1 The tail gas collection system 1 includes a tank area tail gas collection system, a submerged pool tail gas collection system, a furnace top tail gas collection system and a coke outlet pit tail gas collection system. The tank area tail gas collection system, the submerged pool tail gas collection system, the furnace top tail gas collection system and the coke outlet pit tail gas collection system all include a gas collection hood 11, a breathing valve 12 and a tail gas collection pipe 13 located in the collection area. The gas collection hood 11 is connected to the VOCs discharge port of each collection area respectively. The gas collection hood 11 is used to enhance the sealing of the equipment in each collection area and set an effective collection point so as to guide the generated VOCs tail gas to the subsequent processing equipment in time. One end of the tail gas collection pipe 13 is fixedly connected to the gas collection hood 11, and the other end is connected to the spray demisting tower 3. The exhaust gas collection pipes 13 of the furnace top exhaust gas collection system and the coke pit exhaust gas collection system are also connected to a pipeline dust collector 14. Since there are still many solid dust particles in the furnace top exhaust gas and the coke pit exhaust gas, the pipeline dust collector 14 is first set to perform preliminary coarse filtration on the exhaust gas.

[0031] Reference Figure 1 and Figure 2The ends of the tail gas collection pipes 13 of the furnace top tail gas collection system and the coke outlet pit tail gas collection system are connected to the inlet of the sintering plate dust collector 2. The internal filter element of the sintering plate dust collector 2 adopts a sintering plate 21, and a plurality of sintering plates 21 are provided. The plurality of sintering plates 21 are vertically arranged in parallel inside the sintering plate dust collector 2, and the surface of the sintering plate 21 perpendicular to the airflow direction is set as a wavy gathering groove 211. The collected furnace top tail gas and coke outlet pit tail gas are further preliminarily dusted and purified by the sintering plate dust collector 2, so as to facilitate the subsequent VOCs purification treatment.

[0032] Reference Figure 1 and Figure 2 The sintering plate 21 is a wavy sintering plate 21 with gaps after being cast and sintered by a polymer compound assembly, and a PTFE coating is sprayed on its surface. The surface coating is resistant to acid and alkali, moisture, impact, and wear, and has extremely strong hydrophobicity, non-stickiness, and special chemical stability. Its smooth surface makes it difficult for dust to penetrate and stay. Even if some extremely fine dust may enter the gap, it will be blown away by the set pulse compressed air flow, and the tail gas containing sticky dust in the coke outlet area and the furnace top is filtered. The micron-level filter pore size can remove most of the dust and tar droplets, has a high dust removal efficiency, and has a good protective effect on the subsequent spray demisting tower 3.

[0033] Reference Figure 1 The inlet of the spray demisting tower 3 is fixedly connected with the tail gas collection system of the tank area, the tail gas collection pipeline 13 of the tail gas collection system of the submerged pool, and the outlet of the sintering plate dust collector 2 by a pipeline. The first induced draft fan 31 is arranged on the pipeline. The first induced draft fan 31 is used to input the collected and purified tail gas into the spray demisting tower 3. The spray demisting tower 3 adopts a high tower design to reduce the floor space. Its bottom is used as a circulation pool, and the washing circulating water is transported to the spray device in the tower through the circulating water pump 32. The circulating water pump 32 transports the washing circulating water at the bottom of the tower to the spray device in the tower to wash and cool the tail gas, and washes off the water vapor, dust and some volatile organic compounds in the tail gas. By using the height of the spray demisting tower 3 and the demisting device in the tower, the water mist particles are gradually enlarged through the processes of airflow intensification, adsorption, diffusion, condensation and filtration, and the water droplets are separated. The tail gas after removing the large particles of water mist enters the high-efficiency gas-liquid separation tower 4.

[0034] Reference Figure 1 and Figure 3The inlet of the gas-liquid separation tower 4 is connected to the outlet of the spray demister tower 3. The gas-liquid separation tower 4 is provided with a high-efficiency blade demister 41 for separating liquid droplets in the tail gas. The high-efficiency blade demister 41 includes a plurality of guide plates 411 arranged side by side. The surface of the guide plate 411 is provided with a wavy guide groove 4111. The through direction of the guide groove 4111 is perpendicular to the flow direction of the gas along the guide plate 411. A plurality of baffles 412 evenly distributed at intervals are fixedly provided on both sides of the guide plate 411. Both ends of the baffle 412 are integrally provided with a bent flow blocking portion 4121. The flow blocking portions 4121 at both ends of the baffle 412 are arranged in opposite directions. The baffle 412 is S-shaped as a whole. When the gas carrying liquid passes through the high-efficiency blade demister 41, the flow direction of the fluid is changed by the guide plate 411, and then the gas carrying liquid is subjected to continuous kinetic energy collisions with the flow-blocking portion 4121 of the baffle plate 412 under the action of inertial force through collision, agglomeration adsorption, and gravity sedimentation. At the same time, the droplets collide with the blade surface due to surface tension, resulting in a coalescence effect to merge into larger particles, absorbing other droplets to collide with the blade surface and converting into sheet flow. The formed liquid film is collected by its own gravity and then discharged to the bottom of the tank through the liquid guide channel, thereby achieving the purpose of efficient separation. The high-efficiency gas-liquid separation tower 4 can separate droplets larger than 10μm from the gas.

[0035] Reference Figure 1 The combustion system 5 is connected to the outlet of the gas-liquid separation tower 4, and the combustion system 5 includes a direct combustion device 51 and a catalytic combustion device 52. The clean, dry exhaust gas containing VOCs gas treated by the gas-liquid separation tower 4 can be connected to the air blower as air distribution to the direct combustion device 51 for direct combustion without an emission point. The outlet end of the second induced draft fan 53 is connected to the inlet of the catalytic combustion device 52. The catalytic combustion device 52 includes an activated carbon adsorption box for intercepting volatile organic substances. An activated carbon bed is provided in the activated carbon adsorption box. After the activated carbon bed reaches the adsorption saturation state, it is burned under low-temperature flameless conditions through the action of precious metal catalysts such as platinum and palladium with ceramic as the carrier, and the intercepted volatile organic substances are oxidized and decomposed into CO2 and H2O.

[0036] Reference Figure 1 The energy recovery system 6 includes a plurality of heat exchangers 61, which are connected to the exhaust ports of the direct combustion system 5 and the catalytic combustion system 5. The heat exchangers 61 are used to recover the heat energy generated in the combustion system 5 and use it for preheating or other heat energy requirements of the coal low-temperature pyrolysis process.

[0037] Reference Figure 1 The condensate collected from the sintering plate dust collector 2, the spray demisting tower 3, and the high-efficiency gas-liquid separation tower 4 is combined through the condensate collection pipeline 71 and then sent to the wastewater treatment device 7 for treatment.

[0038] The implementation principle of the VOCs treatment device for low-temperature pyrolysis of coal in this embodiment is as follows: when working, the tail gas collection system in the tank area, the tail gas collection system in the submerged pool, the tail gas collection system on the furnace top and the tail gas collection system in the coke pit collect VOCs tail gas through the gas collection hood 11. The gas collection hood 11 is connected to the tail gas collection pipeline 13 to guide the VOCs tail gas to the subsequent treatment equipment.

[0039] The tail gas collection system of the furnace top and the tail gas collection system of the coke pit contain a lot of solid dust particles, so the tail gas will be initially coarsely filtered through the pipeline dust collector 14 before entering the subsequent treatment. The tail gas of the furnace top and the tail gas of the coke pit enter the sintering plate dust collector 2 for preliminary dust removal and purification.

[0040] The sintered plate dust collector 2 adopts a corrugated sintered plate 21, and removes most of the dust and tar droplets through the gaps and coating (PTFE) on the surface of the sintered plate 21.

[0041] Then, the tail gas from the tank area, the tail gas from the submerged pool and the tail gas treated by the sintered plate dust collector 2 enter the spray demister 3. The washing circulating water is transported to the spray device in the tower by the circulating water pump 32 to spray the tail gas, reduce the tail gas temperature, and remove water vapor, dust and volatile organic matter at the same time. The large particles of water mist in the tail gas are removed by using the height and demister of the spray demister 3. Then the tail gas treated by the spray demister 3 enters the high-efficiency gas-liquid separation tower 4. The high-efficiency gas-liquid separation tower 4 uses a high-efficiency blade demister 41 (including a guide plate 411 and a baffle 412) to remove tiny droplets in the tail gas, especially droplets larger than 10 μm. The tail gas treated by the gas-liquid separation tower 4 can enter the direct combustion device 51 for combustion, or be deeply treated by the catalytic combustion device 52. The catalytic combustion device 52 uses activated carbon to adsorb VOCs. When the activated carbon bed is saturated, the VOCs are oxidized and decomposed into CO2 and H2O under low-temperature flameless conditions by the action of the precious metal catalyst. The heat energy generated in the combustion system 5 is recovered through the heat exchanger 61 and used for preheating or other heat energy requirements of the low-temperature pyrolysis process of coal. The condensate collected from the sintering plate dust collector 2, the spray demisting tower 3, and the high-efficiency gas-liquid separation tower 4 is centrally treated by the wastewater treatment device 7. The entire device integrates multiple processing units to achieve effective collection, dust removal, spray demisting, gas-liquid separation, combustion treatment and energy recovery of VOCs tail gas generated during the low-temperature pyrolysis of coal, thereby reducing environmental pollution and improving resource utilization efficiency.

[0042] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A VOCs treatment device for low-temperature coal pyrolysis, characterized in that: include: A tail gas collection system (1) comprises a tank area tail gas collection system, a submerged pool tail gas collection system, a furnace top tail gas collection system and a coke outlet pit tail gas collection system; the tank area tail gas collection system, the submerged pool tail gas collection system, the furnace top tail gas collection system and the coke outlet pit tail gas collection system all comprise a gas collection hood (11) located in the collection area, a breathing valve (12) and a tail gas collection pipeline (13); the breathing valve (12) is connected via the tail gas collection pipeline (13); and the tail gas collection pipelines (13) of the furnace top tail gas collection system and the coke outlet pit tail gas collection system (1) are also connected to a pipeline dust collector (14); The inlet of the sintering plate dust collector (2) is connected to the tail gas collection pipeline (13) of the furnace top tail gas collection system and the coke pit tail gas collection system. The sintering plate dust collector (2) is used for preliminary dust removal and purification of the collected tail gas; A spray demisting tower (3), the inlet of which is connected to the tail gas collection system of the tank area, the tail gas collection pipeline (13) of the submerged pool tail gas collection system, and the outlet of the sintered plate dust collector (2), and a spray device is provided in the spray demisting tower (3) for washing, cooling and cooling the collected tail gas; A gas-liquid separation tower (4), the inlet of which is connected to the outlet of the spray demisting tower (3), and a high-efficiency blade demisting device (41) is provided in the gas-liquid separation tower (4) for separating liquid droplets in the tail gas; A combustion system (5) is connected to the outlet of the high-efficiency gas-liquid separation tower (4), wherein the combustion system (5) comprises a direct combustion device (51) and a catalytic combustion device (52), wherein the catalytic combustion device (52) comprises an activated carbon adsorption box for intercepting volatile organic substances; The wastewater treatment device (7) is used to treat the condensate collected from each treatment device.

2. A VOCs treatment device for low-temperature coal pyrolysis according to claim 1, characterized in that: It also includes an energy recovery system (6), which is used to recover the heat energy generated in the combustion system (5). The energy recovery system (6) includes a heat exchanger (61), and the heat exchanger (61) is connected to the exhaust port of the combustion system (5).

3. The VOCs treatment device for low-temperature coal pyrolysis according to claim 1 is characterized in that: The spray demisting tower (3) is designed as a high tower to reduce the floor space, and its bottom is used as a circulation pool, through which the washing circulating water is transported to the spray device in the tower by a circulating water pump (32).

4. A VOCs treatment device for low-temperature coal pyrolysis according to claim 3, characterized in that: The high-efficiency blade demisting device (41) comprises a plurality of guide plates (411), the surface of the guide plates (411) being provided with wavy guide grooves (4111), the through direction of the guide grooves (4111) being perpendicular to the flow direction of the gas along the guide plates (411), a plurality of baffles (412) being fixedly provided at both sides of the guide plates (411) and being evenly distributed at intervals, both ends of the baffles (412) being integrally provided with bent flow blocking portions (4121), the flow blocking portions (4121) at both ends of the baffles (412) being arranged in opposite directions, and the baffles (412) being S-shaped as a whole.

5. The VOCs treatment device for low-temperature coal pyrolysis according to claim 1 is characterized in that: The internal filter element of the sintered plate dust collector (2) is a sintered plate (21), and a plurality of the sintered plates (21) are provided. The plurality of sintered plates (21) are arranged vertically in parallel inside the sintered plate dust collector (2), and the surface of the sintered plate (21) perpendicular to the airflow direction is arranged as a wave-shaped gathering groove.

6. A VOCs treatment device for low-temperature coal pyrolysis according to claim 5, characterized in that: The surface of the sintered plate (21) is coated with a PTFE coating.

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