A heterogeneous catalytic wet oxidation device suitable for coking wastewater treatment
The design of the heterogeneous catalytic wet oxidation device solves the problems of low efficiency, large footprint, and high cost in coking wastewater treatment, and achieves efficient and stable wastewater degradation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BEIJING BOOTES ELECTRIC POWER SCI & TECH
- Filing Date
- 2025-04-30
- Publication Date
- 2026-07-03
AI Technical Summary
Existing coking wastewater treatment technologies suffer from limited treatment effectiveness, large land area requirements, high costs, susceptibility to environmental factors, and potential for secondary pollution. They are particularly difficult to effectively treat high concentrations of organic pollutants.
The heterogeneous catalytic wet oxidation device includes an equalization tank, a sedimentation tank, a dosing device, a reaction tower, a micro-nano aeration device, and a nano-catalyst layer. It improves oxygen solubility and contact area through pH adjustment, sedimentation, micro-nano bubble generation, and catalyst loading, and utilizes the waste heat of coking flue gas to achieve efficient wastewater treatment.
It improves oxygen utilization, increases gas-liquid contact area and reaction efficiency, reduces equipment footprint, has good stability, avoids catalyst fouling, and achieves efficient degradation of coking wastewater.
Smart Images
Figure CN224450462U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of water treatment technology, specifically, to a heterogeneous catalytic wet oxidation device suitable for treating coking wastewater. Background Technology
[0002] The coking industry, as an important basic industry in my country, plays a vital role in steel production, chemical production, and other fields. However, the production process in this industry inevitably generates a large amount of wastewater containing high levels of organic pollutants, posing a serious threat to the environment.
[0003] Currently, the traditional water treatment technologies widely used in China's coking industry mainly include three types: physical treatment, chemical treatment, and biological treatment. Physical treatment methods primarily involve sedimentation and filtration, using gravity, pressure difference, or mechanical action to separate solid particles from the water. Chemical treatment methods utilize chemical agents to alter the properties of pollutants, making them easier to remove. Common chemical treatment methods include chemical precipitation and redox reactions. Biological treatment methods include activated sludge processes and biofilm processes.
[0004] While traditional wastewater treatment technologies can effectively control wastewater discharge from the coking industry to some extent, their limitations are becoming increasingly apparent with stricter environmental regulations and heightened public awareness. Traditional physical treatment methods have limited effectiveness against certain easily soluble or particulate pollutants, chemical treatment methods may cause secondary pollution, and biological treatment processes are easily affected by environmental factors such as water temperature and pH, lacking stability and requiring large land areas. The characteristics of coking wastewater include high COD content and the presence of recalcitrant compounds such as polycyclic aromatic hydrocarbons and organic ammonia nitrogen, making direct treatment using conventional biological methods difficult.
[0005] Wet air oxidation technology uses air as an oxidant to convert dissolved substances (including inorganic and organic matter) in water into harmless new substances or into forms (gases or solids) that are easily separated and removed from the water, thus achieving the purpose of treatment. Traditional wet oxidation technology requires high temperature and pressure, and relatively long residence time, especially for some recalcitrant organic compounds, resulting in high equipment investment and operating costs. Catalytic wet oxidation has made some improvements on traditional wet oxidation technology, reducing reaction temperature and pressure while improving treatment efficiency. Catalytic wet oxidation is based on the principle of catalytic combustion of organic matter in wastewater under high temperature and pressure to purify high-concentration organic wastewater. Its most significant feature is that hydroxyl radicals are the main oxidant that reacts with organic matter. The organic free radicals generated in the reaction can continue to participate in the chain reaction of ·OH, or generate organic peroxide free radicals, which further undergo oxidative decomposition reactions until they are degraded into the final products CO2 and H2O, thereby achieving the purpose of oxidative decomposition. Catalytic wet oxidation is very effective in treating various harmful, toxic, and recalcitrant high-concentration wastewater and has high practical value.
[0006] Catalytic wet oxidation is further divided into homogeneous catalytic wet oxidation and heterogeneous catalytic wet oxidation. The reaction mechanism of heterogeneous catalytic wet oxidation is mostly attributed to free radical oxidation, mainly including three stages: initiation, propagation, and termination. In heterogeneous catalytic oxidation, the catalyst exists in a solid state, making separation from wastewater convenient. Furthermore, the catalyst possesses advantages such as high activity, ease of separation, and good stability.
[0007] Because oxygen has low solubility and diffusion coefficient in water, oxygen mass transfer becomes a key factor limiting the rate of oxygen-consuming reactions. Simply increasing reaction pressure and temperature to improve oxygen mass transfer efficiency leads to higher costs. Furthermore, catalyst fouling is also a major cause of deteriorated treatment results.
[0008] Therefore, providing a water treatment device that is easy to operate, has stable performance, occupies a small area, has high reaction efficiency, and has a good degradation effect on coking wastewater has become an urgent problem to be solved by those skilled in the art. Summary of the Invention
[0009] This invention provides a heterogeneous catalytic wet oxidation device suitable for coking wastewater treatment. It has a simple process, small footprint, high oxygen utilization rate, and can increase the reaction contact area of catalyst, wastewater and oxygen. It is a water treatment device with good and stable degradation effect and can effectively solve the above problems.
[0010] To achieve the above objectives, the present invention adopts the following technical solution:
[0011] A heterogeneous catalytic wet oxidation device suitable for coking wastewater treatment is characterized in that the device includes an equalization tank (1), a sedimentation tank (2), a dosing device (3), a high-pressure pump (4), a wastewater tubular heat exchanger (5), a reaction tower (6), a gas tubular heat exchanger (7), an air compressor (8), a condenser (9), a gas-liquid separator (10), a tail gas treatment device (11), a spray system (12), a nano-catalyst partition (13), and a micro-nano aeration device (14).
[0012] A heterogeneous catalytic wet oxidation device suitable for coking wastewater treatment is characterized in that: the wastewater enters the equalization tank (1), and after pH adjustment by the dosing device (3) in the equalization tank (1), flocculants and coagulants are added, and after sedimentation in the sedimentation tank (2), it enters the wastewater tubular heat exchanger (5) by the high pressure pump (4), and after heat exchange, it enters the top of the reaction tower (6), and is evenly distributed in the nano-catalyst partition (13) in the tower by the spray system (12) installed at the top of the reaction tower (6); air enters the reaction tower (6) from the micro-nano aeration device (14) at the bottom and middle of the reaction tower (6).
[0013] A heterogeneous catalytic wet oxidation device suitable for coking wastewater treatment is characterized by: a dosing device installed in the equalization tank, which can adjust the pH and add coagulants, and then enter the sedimentation tank for sedimentation. The dosing device and the sedimentation tank can remove most of the suspended solids in the wastewater, avoiding the clogging of the catalyst in the subsequent reaction tower.
[0014] A heterogeneous catalytic wet oxidation device suitable for coking wastewater treatment is characterized by: micro-nano aeration devices being installed in the middle and bottom of the reaction tower respectively. The micro-nano aeration devices generate micro-nano bubbles with slow rising speed and self-pressurization and dissolution, which causes the micro-nano bubbles to gradually shrink to the nanoscale during the slow rising process, and finally disappear and dissolve into the water, thereby greatly improving the solubility of oxygen in water.
[0015] A heterogeneous catalytic wet oxidation device suitable for coking wastewater treatment is characterized in that: wastewater enters the reaction tower through a spray system, and gas enters the tower through micro-nano aeration devices in the middle and bottom of the reaction tower. The spray system and micro-nano aeration devices enable air and wastewater to react in a staged cross-flow manner under the catalytic action of the nano-catalyst layer in the reaction tower, which greatly increases the gas-liquid contact area and improves the reaction efficiency.
[0016] A heterogeneous catalytic wet oxidation device suitable for coking wastewater treatment is characterized in that: the nanocatalyst separator is composed of nanocatalyst uniformly loaded on carbon fibers, the carbon fibers having a well-developed pore structure, providing a large number of active sites, and the high surface area and specific surface area are conducive to loading more nanocatalysts, while also facilitating the contact between the nanocatalysts and oxygen, thereby improving catalytic efficiency.
[0017] A heterogeneous catalytic wet oxidation device suitable for coking wastewater treatment is characterized by: using high-temperature flue gas generated during the coking process to heat air, and then returning the high-temperature flue gas after heat exchange to the flue gas treatment system to realize the utilization of waste heat from the high-temperature flue gas.
[0018] Based on the above-described contents of this utility model, the beneficial effects of this utility model are as follows:
[0019] 1. A dosing device is installed in the equalization tank. The dosing device can adjust the pH and add coagulant. After the wastewater enters the sedimentation tank for sedimentation, most of the suspended solids in the wastewater can be removed, which can avoid the fouling of the nano-catalyst in the subsequent reaction tower.
[0020] 2. Wastewater enters the reaction tower through a spray system at the top, while gas enters the tower through micro-nano aeration devices in the middle and bottom. The spray system and micro-nano aeration devices enable air and wastewater to react in a staged cross-flow manner under the catalytic action of the nano-catalyst layer in the reaction tower, greatly increasing the gas-liquid contact area and improving the reaction efficiency.
[0021] 3. Micro-nano aeration devices are installed in the middle and bottom of the reaction tower respectively. The micro-nano aeration devices generate micro-nano bubbles with slow rising speed and self-pressurization and dissolution. This allows the micro-nano bubbles to gradually shrink to the nanoscale during the slow rising process and finally disappear and dissolve into the water, thereby greatly improving the solubility of gaseous oxygen in water.
[0022] 4. The nanocatalyst separator is composed of nanocatalyst uniformly loaded on carbon fibers. The carbon fibers have a well-developed porous structure, providing a large number of active sites. The high surface area and specific surface area are conducive to loading more nanocatalysts, and at the same time, they are conducive to the contact between nanocatalysts and oxygen, thereby improving catalytic efficiency. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of a heterogeneous catalytic wet oxidation device suitable for treating coking wastewater.
[0024] Among them, 1-equalization tank, 2-sedimentation tank, 3-dosing device, 4-high pressure pump, 5-wastewater tubular heat exchanger, 6-reaction tower, 7-gas tubular heat exchanger, 8-air compressor, 9-condenser, 10-gas-water separator, 11-tail gas treatment device, 12-spray system, 13-nano catalyst partition, 14-micro-nano aeration device.
[0025] Figure 2 This is a schematic diagram of the internal structure of a nanocatalytic separator in a heterogeneous catalytic wet oxidation device suitable for coking wastewater treatment.
[0026] Among them, 13-nano catalyst separator, 15-nano catalyst, 16-carbon fiber cross-section diagram, 17-metal fixing frame. Detailed Implementation
[0027] The present utility model patent will be further described in detail below with reference to the accompanying drawings and examples:
[0028] The directional terms described in this utility model, such as "up," "down," "left," "right," "center," "horizontal," and "top," are based on the directional relationships shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate specific orientations that the device or equipment must have. Therefore, they should not be construed as limitations on this utility model.
[0029] The purpose of this utility model patent is to provide a heterogeneous catalytic wet oxidation device suitable for coking wastewater treatment. It is simple to operate, has stable performance, occupies a small area, and has high oxygen mass transfer efficiency, enabling effective coking wastewater treatment.
[0030] To achieve the above objectives, this utility model patent adopts the following technical solution:
[0031] like Figure 1The image shows an embodiment of a heterogeneous catalytic wet oxidation device for treating coking wastewater according to this utility model. It includes an equalization tank 1, a sedimentation tank 2, a dosing device 3, a high-pressure pump 4, a wastewater tubular heat exchanger 5, a reaction tower 6, a gas tubular heat exchanger 7, an air compressor 8, a condenser 9, a gas-liquid separator 10, a tail gas treatment device 11, a spray system 12, a nano-catalyst partition 13, and a micro-nano aeration device 14. The characteristic feature is that the collected wastewater enters the equalization tank 1, where the pH is adjusted by the dosing device 3, and flocculants and coagulants are added. After the reaction, the wastewater enters the sedimentation tank 2 for sedimentation. The high-pressure pump 4 pumps the wastewater into the wastewater tubular heat exchanger 5 for heat exchange before it enters the reaction tower 6. The wastewater is evenly distributed on the nano-catalyst partition 13 by the spray system 12. Air is pumped into the gas tubular heat exchanger 7 by the air compressor 8 for heat exchange, and then enters the reaction tower 6 through the nano aeration device 14. In the reaction tower 6, the organic matter and oxygen in the wastewater are decomposed under the catalytic action of the nano catalyst 15.
[0032] It should be noted that the wastewater after the reaction in reaction tower 6 is at a high temperature. It is cooled by the wastewater tube heat exchanger 5 from the bottom of reaction tower 6 before being discharged.
[0033] It should be noted that the waste gas generated in the reaction tower 6 is cooled by the condenser 9 after passing through the top of the reaction tower 6, and then separated by the gas-water separator 10. The waste gas enters the tail gas treatment device 11 for treatment, and the moisture returns to the reaction tower 6 through the bottom line of the gas-water separator 10 for further treatment. The oxygen-containing gas is transported to the air compressor 8 for reuse.
[0034] It should be noted that in the conditioning tank 1, after pH adjustment by the dosing device 3, flocculants and coagulants are added to react. After sedimentation in the sedimentation tank 2, most of the suspended solids and some organic matter can be effectively removed, which can largely avoid clogging of the nano-catalyst 15 and extend the life of the nano-catalyst 15.
[0035] It should be noted that in the gas tubular heat exchanger 7, the high-temperature flue gas from the coking plant is used to heat the air, thus utilizing waste heat. The high-temperature flue gas after heat exchange is then returned to the flue gas treatment system.
[0036] It should be noted that the nano-aeration devices 14 are respectively installed at the bottom and middle of the reaction tower 6, and the airflow can be controlled by valves according to the actual situation.
[0037] It should be noted that the air enters the reaction tower 6 from the bottom and middle of the nano-aeration device 14, respectively. The wastewater enters the reaction tower 6 from the bottom through the spray system 12, and reacts in a staged cross-flow manner under the action of the catalyst partition 13 inside the tower. This greatly improves the solubility and utilization rate of oxygen in water, increases the reaction contact area, and thus improves the wastewater pollutant treatment capacity.
[0038] In this implementation case, such as Figure 1 and Figure 2 As shown, the nanocatalyst partition 13 is made by uniformly loading nanocatalyst 15 onto carbon fiber 16. The carbon fiber 16 uniformly loaded with nanocatalyst 15 is fixed to the metal fixing frame 17 in a mesh-like cross, ensuring that the water flow can pass through each nanocatalyst partition 13 evenly and smoothly.
[0039] It should be noted that the number of nanocatalyst separators 13 can be adjusted according to the degree of pollution of the wastewater, which facilitates cost control.
[0040] It should be noted that the carbon fiber 16 has a well-developed pore structure, providing a large number of active sites. The high surface area and specific surface area are conducive to loading more nano-catalysts 15, and at the same time, they are conducive to the contact between nano-catalysts 15 and oxygen, thereby improving catalytic efficiency.
[0041] It should be noted that the metal fixing frame 17 is made of 316 stainless steel and has fixing holes.
[0042] The foregoing detailed description of one embodiment of this utility model patent is merely a preferred embodiment and is not intended to limit the scope of this utility model. Any simple modifications, equivalent substitutions, and alterations made within the scope of this patent application should fall within the patent coverage of this invention.
Claims
1. A heterogeneous catalytic wet oxidation apparatus suitable for coking wastewater treatment, characterized by, The device includes an equalization tank (1), a sedimentation tank (2), a dosing device (3), a high-pressure pump (4), a wastewater tubular heat exchanger (5), a reaction tower (6), a gas tubular heat exchanger (7), an air compressor (8), a condenser (9), a gas-liquid separator (10), and a tail gas treatment device (11); the reaction tower (6) includes a spray system (12), a nano-catalyst partition (13), and a micro-nano aeration device (14); the nano-catalyst partition (13) includes a nano-catalyst (15), carbon fiber (16), and a metal fixing frame (17); the dosing device (3) and the equalization tank (4) are connected to the sedimentation tank (5). The regulating tank (1) is connected to the sedimentation tank (2), the sedimentation tank (2) is connected to the high-pressure pump (4), the high-pressure pump (4) is connected to the wastewater tubular heat exchanger (5), the wastewater tubular heat exchanger (5) is connected to the spray system (12) inside the reaction tower (6); the tail gas treatment device (11) is connected to the gas-water separator (10), the gas-water separator (10) is connected to the condenser (9), the condenser (9) is connected to the reaction tower (6); the air compressor (8) is connected to the gas tubular heat exchanger (7), the gas tubular heat exchanger (7) is connected to the micro-nano aeration device (14) inside the reaction tower (6).
2. A heterogeneous catalytic wet air oxidation device suitable for coking wastewater treatment according to claim 1, characterized in that, The reaction tower (6) is equipped with a nano-catalyst partition (13), and the number of nano-catalyst partitions (13) can be arranged according to the actual situation.
3. A heterogeneous catalytic wet air oxidation device suitable for coking wastewater treatment according to claim 1, characterized in that, The nanocatalyst partition (13) is made by uniformly loading nanocatalyst (15) onto carbon fiber (16). All the carbon fibers (16) uniformly loaded with nanocatalyst (15) are fixed in a mesh-like cross on a metal fixing frame (17) to ensure that the water flow can pass through each nanocatalyst partition (13) evenly and smoothly.
4. A heterogeneous catalytic wet air oxidation device suitable for coking wastewater treatment according to claim 1, characterized in that, The metal fixing frame (17) is made of 316 stainless steel and has fixing holes.
5. A heterogeneous catalytic wet air oxidation device suitable for coking wastewater treatment according to claim 1, characterized in that, The nanocatalyst (15) can be one of TiO2 catalyst, AU-TiO2 catalyst or Ag-TiO2 catalyst.