Cooperative treatment system for multiple pollutants such as NOx, SOx, CO and VOCs in coke oven flue gas
By designing a collaborative treatment system for multiple pollutants and using the combination of fixed bed and catalyst layers, the problems of low efficiency and failure to deal with CO and VOCs in traditional treatment processes are solved, and efficient removal of multiple pollutants in coke oven flue gas is achieved and the recycling of resources is achieved.
Patent Information
- Application Number
- CN202421494970.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-27
- Publication Date
- 2025-05-27
- Estimated Expiration
- 2034-06-27
AI Technical Summary
The traditional coke oven flue gas treatment process is not efficient, fails to effectively treat CO and VOCs, and does not perform pretreatment, which affects the stable operation of downstream equipment and coke ovens.
A collaborative treatment system for multiple pollutants such as NOx, SOx, CO and VOCs of coke oven flue gases is designed, including fixed beds, dust collectors, heat exchangers, reaction towers and other equipment. Through the combination of multi-layer bed structure and catalyst layer, the synergistic removal of multiple pollutants is achieved.
It realizes ultra-low emissions of multiple pollutants in coke oven flue gas, improves the safety and stability of the system, extends the uptime of the coke oven, and realizes the recycling of resources.
Smart Images
Figure CN222900684U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of air pollution control, in particular to a multi-pollutant collaborative treatment system for NOx, SOx, CO, VOCs and other pollutants in coke oven flue gas.
Background Art
[0002] A coke oven is a furnace used to refine coke. Coal materials are heated into coke under the condition of air isolation. The volatile components in the coal are heated to form coke oven gas for recycling. Due to the particularity of the production process, the coke oven flue gas contains pollutants such as dust particles, coal tar, VOCs, CO, SOx and NOx. With the increasing environmental protection requirements, the collaborative treatment of pollutants in coke oven flue gas becomes particularly important.
[0003] In the traditional treatment process, the coke oven flue gas treatment device generally discharges after simple desulfurization, dust removal and denitrification processes. The treatment efficiency is not high, the operation is unstable, and CO and VOCs are not treated. At the same time, the coke oven flue gas is not pretreated, and coal tar has a great impact on downstream equipment, and in severe cases, the coke oven cannot operate normally.
[0004] In order to further achieve the collaborative and stable and efficient treatment of multi-pollution in coke oven flue gas, a multi-pollutant collaborative treatment system for NOx, SOx, CO, VOCs and other pollutants in coke oven flue gas is specifically proposed.
Content of the Utility Model
[0005] The purpose of the utility model is to solve the problems in the prior art, and propose a multi-pollutant collaborative treatment system for NOx, SOx, CO, VOCs and other pollutants in coke oven flue gas, which can solve at least one of the above problems.
[0006] To achieve the above purpose, the utility model proposes a multi-pollutant collaborative treatment system for NOx, SOx, CO, VOCs and other pollutants in coke oven flue gas, including a coke oven. The flue gas outlet of the coke oven is connected to the cold-side flue gas inlet of a heat exchanger through a fixed bed and a dust collector connected in sequence. The cold-side flue gas outlet of the heat exchanger is connected to the hot-side flue gas inlet of the heat exchanger through a reaction tower one and a reaction tower two connected in sequence. The hot-side flue gas outlet of the heat exchanger is connected to a chimney through a draft fan. A deacidifying agent metering and conveying device is connected to the inlet flue of the dust collector. A reducing agent regulating and metering device is arranged at the upper part of the reaction tower one. A burner and a temperature transmitter above the burner are arranged at the lower part of the reaction tower one. The fixed bed includes that there are several bed layers arranged in a shell body, and fillers are filled in the bed layers.
[0007] Preferably, the number of the bed layers is two and they are arranged at intervals in sequence. A differential pressure transmitter is arranged between the shell bodies on the front and back sides of each bed layer.
[0008] Preferably, the filler is rough-surfaced coke.
[0009] Preferably, a number of precious metal catalyst layers are provided at intervals in the first reaction tower between the reducing agent metering device and the temperature transmitter.
[0010] Preferably, a number of denitration catalyst layers are provided at intervals in the second reaction tower.
[0011] The beneficial effects of the present utility model are as follows: 1. It can achieve the collaborative treatment of multiple pollutants, effectively and synergistically remove unconventional pollutants in coke oven flue gas such as coal tar, VOCs, and CO, and achieve the ultra-low emission of multiple pollutants in coke oven flue gas. At the same time, it greatly improves the safety of the system and is conducive to the long-term stable operation of the coke oven;
[0012] 2. The filler in the fixed bed uses locally available coke, which can not only effectively remove coal tar and part of the dust, but also remove part of the VOCs. At the same time, the saturated adsorbent filler can be calcined in the coke oven or recycled as other fuels, thus truly realizing the recycling of resources.
[0013] The features and advantages of the present utility model will be described in detail through embodiments in conjunction with the drawings.
Description of the Drawings
[0014] Figure 1 It is a schematic structural diagram of a system for the collaborative treatment of multiple pollutants such as NOx, SOx, CO, and VOCs in coke oven flue gas of the present utility model.
[0015] In the figure: 1 - coke oven, 2 - fixed bed, 3 - acid removal agent metering and conveying device, 4 - dust collector, 5 - heat exchanger, 6 - burner, 7 - temperature transmitter, 8 - first reaction tower, 9 - reducing agent metering device, 10 - second reaction tower, 11 - induced draft fan, 12 - chimney, 20 - housing, 21 - bed layer, 22 - filler, 23 - differential pressure transmitter, 81 - precious metal catalyst layer, 101 - denitration catalyst layer.
Specific Embodiments
[0016] Refer to Figure 1, the present utility model relates to a multi-pollutant collaborative treatment system for NOx, SOx, CO, VOCs, etc. in coke oven flue gas, including a coke oven 1. The flue gas outlet of the coke oven 1 is connected to the cold-side flue gas inlet of a heat exchanger 5 through a fixed bed 2 and a dust collector 4 connected in sequence. The cold-side flue gas outlet of the heat exchanger 5 is connected to the hot-side flue gas inlet of the heat exchanger 5 through a reaction tower one 8 and a reaction tower two 10 connected in sequence. The hot-side flue gas outlet of the heat exchanger 5 is connected to a chimney 12 through a induced draft fan 11. A deacidifying agent metering and conveying device 3 is connected to the inlet flue of the dust collector 4. The upper part of the reaction tower one 8 is provided with a reducing agent regulating and metering device 9. The lower part of the reaction tower one 8 is provided with a burner 6 and a temperature transmitter 7 above the burner 6. The fixed bed 2 includes a housing 20, and several bed layers 21 are arranged in the housing 20. Packing 22 is filled in the bed layers 21.
[0017] The number of the bed layers 21 is two and they are arranged at intervals in sequence. Differential pressure transmitters 23 are arranged between the housing 20 on the front and rear sides of each bed layer 21.
[0018] The packing 22 uses coke with a rough surface.
[0019] Several precious metal catalyst layers 81 arranged at intervals are provided in the reaction tower one 8 between the reducing agent regulating and metering device 9 and the temperature transmitter 7.
[0020] Several denitration catalyst layers 101 arranged at intervals are provided in the reaction tower two 10.
[0021] The working process of the present utility model:
[0022] During the working process of a multi-pollutant collaborative treatment system for NOx, SOx, CO, VOCs, etc. in coke oven flue gas of the present utility model, first, the flue gas discharged from the coke oven 1 contains a large amount of pollutants such as NOx, SOx, VOCs, coal tar, and dust particles. The flue gas first enters the fixed bed 2. The fixed bed 2 is mainly used to remove coal tar. The fixed bed is provided with no less than 2 bed layers 21. Packing 22 is loaded into the bed layers. The packing 22 can use block-shaped coke. Differential pressure transmitters 23 are arranged on both sides of the bed layer 21 to detect the differential pressure of the bed layer 21. When the differential pressure reaches a certain value, the packing 22 of the bed layer 21 is replaced. The replaced packing can be recycled in the coke oven or used as fuel for combustion, so as to achieve the purpose of waste resource recovery and utilization. At least 2 layers of bed layers 21 are provided. When the packing of the first layer is replaced, the second bed layer can ensure the effective removal of coal tar and some dust particles. The packing 22 can also remove some high-molecular VOCs at the same time.
[0023] The pre-treated flue gas enters the dust collector 4. A deacidifying agent metering and conveying device 3 (which is prior art and will not be elaborated here) is provided at the inlet of the dust collector 4 to evenly spray the deacidifying agent into the inlet of the dust collector 4. The deacidifying agent uses sodium bicarbonate with a certain particle size and is sprayed into the dust collector inlet in the form of dry powder, and reacts with acidic gases such as SO 2 and SO 3 as well as HCl in the flue gas, so as to achieve the purpose of deacidification. After the mixed flue gas after the deacidification reaction is separated by the dust collector 4, the ash hopper removed is discharged from the bottom, and the clean flue gas enters the heat exchanger 5.
[0024] The flue gas entering the heat exchanger 5 is generally about 200 °C, and exchanges heat with the flue gas coming out of the denitration, so as to increase the temperature of the flue gas. The heated flue gas enters the reaction tower 1 8. In order to ensure that the temperature of the flue gas can reach the ignition temperature of CO and VOCs, a burner 6 and a temperature transmitter 7 are provided in front of the reaction tower 1 8. The burner 6 is adjusted according to the temperature transmitter 7 to ensure that the temperature of the flue gas entering the reaction tower 1 8 meets the ignition temperature of CO and OCs.
[0025] The heated flue gas enters the reaction tower 1 8. A noble metal catalyst layer is provided in the reaction tower 1 8. The noble metal catalyst layer is arranged in multiple layers to ensure the removal effect. Under the catalysis of the noble metal catalyst, VOCs and CO in the flue gas are catalytically oxidized into CO 2 and H 2 2O, so as to achieve the purpose of removing pollutants. At the same time, the catalyst oxidation is an exothermic reaction. After the oxidation reaction of high-concentration VOCs and CO, a large amount of heat will be released, which will increase the temperature of the flue gas again and make it meet the requirements of the denitration reaction. A reducing agent regulating and metering device 9 (which is prior art and will not be elaborated here) is provided between the reaction tower 2 10 and the reaction tower 1 8 to spray the reducing agent for the denitration reaction. A denitration catalyst layer is provided in the reaction tower 2 10. The denitration catalyst layer is arranged in multiple layers to ensure the denitration efficiency.
[0026] The high-temperature flue gas after denitration enters the heat exchanger 5 and exchanges heat with the cold flue gas to achieve the effect of energy saving. The final clean flue gas is discharged to the chimney 12 through the induced draft fan 11.
[0027] The above embodiments are illustrative of the present invention and not restrictive thereof. Any simple transformation of the present invention also falls within the protection scope of the present invention.
Claims
1. A system for the coordinated treatment of multiple pollutants such as NOx, SOx, CO and VOCs in coke oven flue gas, characterized by: The invention comprises a coke oven (1), wherein the flue gas outlet of the coke oven (1) is connected to the cold-side flue gas inlet of a heat exchanger (5) through a fixed bed (2) and a dust collector (4) which are connected in sequence, the cold-side flue gas outlet of the heat exchanger (5) is connected to the hot-side flue gas inlet of the heat exchanger (5) through a reaction tower 1 (8) and a reaction tower 2 (10) which are connected in sequence, the hot-side flue gas outlet of the heat exchanger (5) is connected to a chimney (12) through an induced draft fan (11), a deacidifying agent metering and conveying device (3) is connected to the inlet flue of the dust collector (4), a reducing agent regulating and metering device (9) is provided at the upper part of the reaction tower 1 (8), a burner (6) and a temperature transmitter (7) located above the burner (6) are provided at the lower part of the reaction tower 1 (8), and the fixed bed (2) comprises a shell (20), a plurality of bed layers (21) are provided in the shell (20), and the bed layers (21) are filled with fillers (22).
2. A system for coking oven flue gas NOx, SOx, CO, VOCs and other pollutants coordinated treatment as claimed in claim 1, characterized in that: The number of the bed layers (21) is two and they are arranged in sequence and at intervals. A differential pressure transmitter (23) is provided between the shells (20) on the front and rear sides of each bed layer (21).
3. A system for coking oven flue gas NOx, SOx, CO, VOCs and other pollutants coordinated treatment as claimed in claim 1, characterized in that: The filler (22) is coke with a rough surface.
4. A system for coking oven flue gas NOx, SOx, CO, VOCs and other pollutants coordinated treatment as claimed in claim 1, characterized in that: A plurality of precious metal catalyst layers (81) are arranged at intervals in the reaction tower 1 (8) between the reducing agent regulating and metering device (9) and the temperature transmitter (7).
5. A system for coking oven flue gas multi-pollutants such as NOx, SOx, CO and VOCs as claimed in any one of claims 1 to 4, characterized in that: The second reaction tower (10) is provided with a plurality of denitration catalyst layers (101) arranged at intervals.