An apparatus and method for co-producing steam using catalytic wet oxidation.

Abstract

This invention discloses an apparatus and method for co-producing steam using catalytic wet oxidation. The reactor of the apparatus is equipped with a heat extraction module, which includes a heat exchange chamber and a heat extraction medium inlet and outlet connecting to the heat exchange chamber. The heat extraction module also has multiple channels spaced apart from the heat exchange chamber along its thickness for radial flow of materials within the reactor. By incorporating a heat extraction module inside the reactor, this invention can promptly remove the heat of reaction from the catalytic wet oxidation reaction, ensuring the reactor operates at a constant temperature. This significantly improves the reactor's adaptability to TOC content in wastewater. Simultaneously, the heat removed from the reactor can be co-produced using a steam generator. This invention's reaction system not only achieves catalytic wet oxidation treatment of high-content organic wastewater but also realizes comprehensive heat utilization, further reducing wastewater treatment costs.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment and relates to an apparatus and method for co-producing steam using catalytic wet oxidation. Specifically, it relates to an apparatus for treating wastewater using catalytic wet oxidation and a method for co-producing steam using the heat of reaction during oxidation. Background Technology

[0002] Wet oxidation (WAO) is an effective method for treating toxic, hazardous, and highly concentrated organic wastewater, developed in the 1950s. Under high temperature and pressure, WAO utilizes an oxidant to oxidize and degrade dissolved or suspended organic matter in wastewater, thereby removing pollutants. During the WAO reaction, organic pollutants are oxidized and decomposed into easily biodegradable small molecules or mineralized into harmless inorganic substances such as carbon dioxide, water, and inorganic salts. Sulfur in organic pollutants is generally converted to sulfates, halogens to halides, and phosphorus to phosphates. Wet oxidation is characterized by its wide applicability, high treatment efficiency, low secondary pollution, fast oxidation rate, and the ability to recover energy and useful materials. Since the 1970s, wet oxidation technology has developed rapidly, expanding its application from recovering useful chemicals and energy to treating toxic and hazardous waste, particularly in the treatment of toxic and hazardous substances containing phenols, phosphorus, and cyanide, with numerous literature reports on its application. Abroad, WAO technology has been industrialized and is mainly used for activated carbon regeneration, cyanide-containing wastewater, coal gasification wastewater, papermaking black liquor, and the treatment of municipal sludge and landfill leachate. In China, research on WAO only began in the 1980s, with studies conducted on papermaking black liquor, sulfur-containing wastewater, phenol-containing wastewater, coal gasification wastewater, pesticide wastewater, and dyeing and printing wastewater.

[0003] However, WAO technology also has certain problems. Mainly, it cannot achieve complete mineralization of organic matter and may produce low-molecular-weight oxygen-containing compounds (especially acetic acid, propionic acid, methanol, ethanol, and acetaldehyde). Furthermore, WAO is not ideal for treating structurally stable compounds such as polychlorinated biphenyls (PCBs). Therefore, WAO is generally used as a pretreatment step for wastewater containing structurally stable compounds like PCBs, and the pretreated wastewater is then discharged after biological treatment. Therefore, to improve the decomposition efficiency of organic matter in wet oxidation processes, catalytic wet oxidation methods using efficient and stable catalysts have been developed based on traditional wet air oxidation. This method uses oxygen-enriched gas or oxygen as the oxidant, and under certain temperature, pressure, and catalyst conditions, it further enhances the decomposition efficiency of organic matter in wet oxidation processes. This method uses oxygen-enriched gas or oxygen as the oxidant, and utilizes the catalytic effect of a catalyst to lower the activation energy of the wet oxidation reaction, thereby accelerating the reaction between organic matter in wastewater and the oxidant. This oxidizes organic matter and poisons containing nitrogen and sulfur in the wastewater into CO2, N2, SO2, and H2O, achieving the purpose of wastewater purification. Catalysts used for wet oxidation treatment can be divided into two types: homogeneous oxidation catalysts and heterogeneous oxidation catalysts.

[0004] In recent years, driven by national industrial policies, the utilization of waste salt (water) resources has gained increasing attention, creating new application scenarios for catalytic wet oxidation. However, existing catalytic wet oxidation methods require the TOC concentration in wastewater to be within a reasonable range. When the TOC concentration is too low, the catalytic wet oxidation reaction requires a large amount of additional heat energy; conversely, when the TOC concentration is too high, the release of heat from the catalytic wet oxidation reaction causes a rise in reaction temperature, which in turn enhances the corrosiveness of the materials, accelerating the corrosion of the catalytic wet oxidation equipment. Furthermore, the increased temperature also leads to increased reaction pressure, making the entire system prone to material leakage, thus seriously threatening the operational safety of the catalytic wet oxidation reactor. Additionally, the reaction heat requires a large amount of circulating water for cooling, resulting in energy waste, increased operating costs, and decreased economic benefits. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention provides a catalytic wet oxidation reactor, wherein a heat extraction module is provided within the reactor.

[0006] According to an embodiment of the present invention, the heat extraction module is concentrically located within the reactor. Preferably, the heat extraction module is coaxially located within the reactor.

[0007] According to an embodiment of the present invention, the outer diameter of the heat extraction module is smaller than the inner diameter of the reactor. Preferably, the ratio of the outer diameter of the heat extraction module to the inner diameter of the reactor is (0.95~1):1.

[0008] According to an embodiment of the present invention, the heat extraction module is provided with a heat exchange cavity and a heat extraction medium inlet and a heat extraction medium outlet communicating with the heat exchange cavity, and the heat extraction module is provided with a plurality of channels along the thickness direction that are spaced apart from the heat exchange cavity for radial flow of materials in the reactor.

[0009] According to an embodiment of the present invention, the plurality of channels for radial flow of materials in the reactor, which are spaced apart from the heat exchange chamber, are uniformly spaced.

[0010] According to an embodiment of the present invention, the heat exchange cavity is divided into multiple spaces along the thickness direction, and adjacent spaces are connected by through holes. The heat exchange medium inlet and outlet are respectively connected to the spaces located at both ends of the multiple spaces. Preferably, adjacent through holes are arranged radially opposite to each other.

[0011] According to an embodiment of the present invention, the total cross-sectional area of ​​all through holes is 0.1%-1% of the cross-sectional area of ​​the heat exchange cavity, for example 0.1%, 0.2%, 0.5%, 0.8%, and 1%.

[0012] According to an embodiment of the present invention, the diameter of all through holes can be 2-8 mm, with 5 mm being an example.

[0013] According to an embodiment of the present invention, an inspection channel is further provided in the middle of the heat extraction module. Preferably, a movable cover plate is provided on the inspection channel. Preferably, the cover plate is square. For example, the side length of the cover plate is 500-700 mm.

[0014] The heat extraction module of this invention combines the functions of heat exchange and trays, achieving the goal of reducing the number of reactor internals and saving costs. The heat extraction module has through-holes that allow the material in the reactor to flow axially from bottom to top. It can also redistribute the material to prevent short circuits. Furthermore, a maintenance passage is provided in the center of the heat extraction module, and the maintenance passage adopts a cover design, allowing for easy access for personnel when maintenance is needed.

[0015] According to an embodiment of the present invention, the reactor is further provided with a gas distributor located at the bottom of the heat extraction module. The gas distributor can generate a large number of millimeter-sized bubbles, which enhances the mass transfer process during the reaction, facilitates the formation of more free radicals, and promotes the efficient progress of the oxidation reaction. Within the same residence time, it can effectively reduce the TOC content in the wastewater, thereby ensuring the effluent quality at the reactor outlet.

[0016] According to an embodiment of the present invention, the reactor can be composed of multiple reactors connected in series, or multiple heat extraction modules can be axially arranged within a single reactor. Preferably, multiple heat extraction modules are axially arranged within the reactor. For example, 1-8 heat extraction modules can be axially arranged within the reactor.

[0017] According to an embodiment of the present invention, a plurality of heat-collecting modules are uniformly arranged axially within the reactor. Preferably, the height distance between two adjacent heat-collecting modules is 1800-2200mm, exemplarily 1800mm, 1900mm, 2000mm, 2100mm, and 2200mm.

[0018] Setting multiple heat extraction modules axially inside the reactor can ensure precise temperature control within the reactor, allowing for timely adjustment of the temperature in different sections of the reactor based on the reaction results.

[0019] According to an embodiment of the present invention, the thickness of the heat extraction module is 60-200mm, with exemplary thicknesses of 60mm, 80mm, 100mm, 120mm, 150mm, 180mm, and 200mm.

[0020] The heat extraction module of this invention can operate under high temperature and high pressure, and can withstand a single-sided high pressure difference, thereby greatly improving the safety of the reaction. At the same time, the heat extraction module used in this invention ensures uniform heat extraction within the reactor and guarantees a favorable construction and maintenance environment.

[0021] According to an embodiment of the present invention, the heat extraction medium is preferably a heat transfer medium, such as water or heat transfer oil.

[0022] According to an embodiment of the present invention, the reactor is further provided with a catalyst recovery unit. For example, the catalyst is a catalyst known in the art for use in catalytic wet oxidation processes, preferably a copper-containing catalyst. An example is copper chloride.

[0023] According to an embodiment of the present invention, the reactor further includes components required for the catalytic wet oxidation reaction. These components include, but are not limited to, one or more selected from an inlet unit, an outlet unit, a feed unit, a discharge unit, and an instrumentation unit. Those skilled in the art will understand that when the reactor is equipped with the above-mentioned components, the components should not affect the airtightness of the reactor. For this purpose, the components can be connected to the reactor by welding, flanges, and / or piping. It should be understood that the structure and function of the components are known in the art. For example, the inlet unit and outlet unit can be used to introduce oxygen and / or air to enable the catalytic wet oxidation reaction. The feed unit can be used to introduce wastewater that needs to be treated, and the discharge unit can be used to discharge reaction products or undesirable residues. The instrumentation unit can be used to display or monitor the process parameters of the reactor.

[0024] In one embodiment of the present invention, the feeding unit includes a wastewater storage unit and a conveying unit. For example, the wastewater storage unit is a wastewater storage tank; the conveying unit is a high-pressure pump.

[0025] In one embodiment of the present invention, the instrument unit includes a temperature sensor, a pressure sensor, an online TOC analyzer, an online pH meter, an online copper ion detector, and a liquid level sensor. Preferably, the temperature sensor, pressure sensor, and liquid level sensor are interlocked.

[0026] The present invention also provides a catalytic wet oxidation reaction system comprising the above-described reactor.

[0027] According to an embodiment of the present invention, the reaction system further includes a preheater and a heater connected in series with the feeding unit, wherein the outlet of the heater is connected to the inlet of the reactor.

[0028] According to an embodiment of the present invention, the reaction system further includes a steam generator, the inlet of which is connected to the heat extraction medium outlet of the heat extraction module. The steam generator of the present invention can achieve automatic steam pressure control and automatically adjust the steam flow rate according to the amount of heat of reaction obtained. According to an embodiment of the present invention, a distributor is provided inside the steam generator. The steam generator realizes the flash evaporation of superheated water to produce steam and can also extract superheated water. The heat of reaction from the extracted hot water at the heat extraction medium outlet raises the water temperature in the steam generator, forming steam. When the steam pressure is greater than the preset pressure of the steam generator, the steam is discharged into the steam network through a pipeline. After the steam is discharged, the pressure inside the steam generator decreases, and the supply of steam to the steam network stops. When the hot water level in the steam generator is high, hot water can be directly extracted from the bottom of the steam generator for use in other devices to further recover heat. The extracted hot water continuously extracts heat from the reactor, causing the temperature of the extracted hot water to rise, which in turn raises the pressure inside the steam generator, resulting in the discharge of steam, thus repeating the cycle.

[0029] According to an embodiment of the present invention, the steam generator is equipped with a level gauge. When the water level in the steam generator rises, the drain valve is automatically opened to discharge hot water.

[0030] According to an embodiment of the present invention, the steam outlet of the steam generator can be connected to the heat exchange medium inlet of the lowest heat exchange module in the reactor.

[0031] The heat removed from the reactor can be used to generate steam through a steam generator. Part of the generated steam can then be used to heat the heat exchange medium in the lowest heat exchange module to increase its temperature and thus input heat into the reactor, thereby increasing the rate of the wet oxidation reaction and ensuring the effectiveness of the wet oxidation reaction.

[0032] According to an embodiment of the present invention, the reaction system further includes a gas-liquid separation unit (such as a gas-liquid separation tank) connected to a preheater.

[0033] According to an embodiment of the present invention, the reaction system further includes a condensation unit connected to the gas outlet of the gas-liquid separator.

[0034] According to an embodiment of the present invention, the reaction system further includes a post-treatment unit connected to the liquid outlet of a gas-liquid separator. This is used for further purification and recovery of metal ions in wastewater.

[0035] The reactor of this invention is equipped with a safety valve or rupture disc, etc. If the reactor is at risk of overpressure, the material is automatically released into the gas-liquid separator. The high-temperature gas enters the condenser at the top of the gas-liquid separator and is condensed into liquid, which flows into the gas-liquid separator by gravity. The liquid in the gas-liquid separator is pumped to the post-treatment unit for further purification and recovery of metal ions in the wastewater.

[0036] According to an embodiment of the present invention, the reaction system further includes an exhaust gas treatment unit, which is connected to the non-condensable gas outlet of the gas-liquid separator.

[0037] In this invention, after the reacted material exits the reactor, it passes through a preheater to further recover residual heat, and then enters a gas-liquid separator after pressure reduction. The partially vaporized liquid in the gas-liquid separator is condensed by a condensation unit (such as a condenser) at the top of the separator and then returned to the separator. It is then pumped to a post-treatment unit for further purification and recovery of metal ions in the wastewater. The non-condensable gas is sent to a tail gas treatment unit for further processing.

[0038] According to an embodiment of the present invention, the reaction system further includes a DCS (Distributed Control System) control system and a SIS (Safety Instrumented System) control system.

[0039] The DCS control system primarily adjusts the pump's frequency conversion (speed) through control logic or manual input commands, thereby regulating valve opening, shut-off valve status, and controlling the setpoints of process parameters such as temperature, pressure, liquid level, flow rate, pH value, and copper ion content. The DCS control system displays real-time status of various process parameters, including flow rate, temperature, pressure, liquid level, pH value, copper ion content, and the operating status of rotating equipment, providing crucial information for production adjustments. The SIS system, primarily a safety instrumented system, exists independently of the DCS control system. When key parameters such as temperature, pressure, and flow rate exceed setpoints, it automatically triggers interlocks to maintain the system in a safe state.

[0040] According to an exemplary embodiment of the present invention, the DCS control system includes detection instruments, cards (for acquiring signals from the detection instruments and outputting analog or digital signals to actuators), an instrument transmission network, and a control station.

[0041] In one embodiment of the present invention, the detection instrument includes a thermometer, a pressure gauge, and a flow meter.

[0042] In one embodiment of the invention, a remote thermometer is provided between two adjacent heat extraction modules of the reactor. For example, the remote thermometer can be inserted into the reactor, or an infrared thermometer can be used to detect the temperature of the outer wall of the reactor to monitor the temperature inside the reactor.

[0043] In this invention, the temperature detected by the thermometer and the flow rate of the heat-extracting medium in the heat-extracting module form a control loop. Simultaneously, the flow meter and the heat-extracting medium flow regulating valve of the heat-extracting module form another control loop, ultimately achieving regulation of the heat-extracting medium flow rate of two adjacent heat-extracting modules within the reactor, thereby stabilizing the temperature within the reactor. Furthermore, the DCS control system can control the heat-extracting medium flow rate of the heat-extracting module below the thermometer or selectively control the heat-extracting medium flow rate of the heat-extracting module above it. The control loop selection allows for control of the heat-extracting medium flow rate of two adjacent heat-extracting modules.

[0044] In one embodiment of the invention, the control station includes an engineer station and an operator station.

[0045] In one embodiment of the present invention, the DCS control system and the SIS control system are each independently equipped with an uninterruptible power supply (UPS power supply).

[0046] The present invention also provides an apparatus for co-producing steam using catalytic wet oxidation, which includes the above-described reaction system.

[0047] The present invention also provides a method for co-producing steam using catalytic wet oxidation, comprising, in the above-mentioned reaction system, subjecting wastewater to catalytic wet oxidation in a reactor, and using the heat released by the catalytic wet oxidation reaction to co-produce steam in a steam generator.

[0048] The present invention also provides a wastewater treatment method, comprising subjecting wastewater to a catalytic wet oxidation reaction in the above-mentioned reactor or reaction system to achieve wastewater purification.

[0049] According to an embodiment of the present invention, the operating temperature of the reactor is between 150-300°C, preferably stable at around 280°C.

[0050] According to an embodiment of the present invention, during the catalytic wet oxidation reaction, the pH value of the wastewater is between 0.8 and 1.4, for example 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, and 1.4.

[0051] According to an embodiment of the present invention, the catalyst used in the catalytic wet oxidation reaction can be any catalyst known in the art for use in catalytic wet oxidation methods, preferably a copper-containing catalyst. For example, the copper ion content is between 1000-3000 ppm.

[0052] According to an embodiment of the present invention, the TOC content in the wastewater can be 1000-50000 ppm.

[0053] According to an embodiment of the present invention, in the catalytic wet oxidation reaction, the flow rate of the heat extraction medium inlet is 1 to 3 m / s, exemplarily 1 m / s, 2 m / s, and 3 m / s.

[0054] According to an embodiment of the present invention, in the catalytic wet oxidation reaction, the inlet flow velocity of the heat recovery medium outlet is 1 to 3 m / s, exemplarily 1 m / s, 2 m / s, and 3 m / s.

[0055] According to an embodiment of the present invention, in the catalytic wet oxidation reaction, the inlet flow rate of the wastewater is 1-2 m / s, exemplarily 1 m / s, 1.5 m / s, or 2 m / s.

[0056] According to an embodiment of the present invention, in the catalytic wet oxidation reaction, the flow rate of wastewater in the reactor is 0.05-0.2 m / min, exemplarily 0.05 m / min, 0.1 m / min, 0.15 m / min, and 0.2 m / min.

[0057] According to an embodiment of the present invention, the wastewater may contain mineral salts, primarily sodium chloride, and also contains small amounts of phosphates, nitrates, and sulfates. For example, the wastewater may contain sodium chloride. Preferably, the mass fraction of sodium chloride in the wastewater can be as high as 21%.

[0058] The beneficial effects of this invention:

[0059] (1) This invention, by setting a heat removal module inside the reactor, can promptly remove the heat of reaction from the catalytic wet oxidation reaction, ensuring that the reactor operates at a constant temperature, thereby greatly improving the reactor's adaptability to TOC content in wastewater. The reactor of this invention can promptly remove the heat generated when high-TOC-concentration organic wastewater enters the reactor for catalytic wet oxidation, ensuring the safe and stable operation of the reactor. Simultaneously, the heat removed by the reactor can be used to co-generate steam through a steam generator. Part of the co-generated steam can be used to heat the wastewater entering the reactor to increase its temperature, and it can also be sent to other users. Furthermore, the hot water generated by the steam generator can also be supplied to other users to further recover the heat from the hot water generated by the steam generator. The reaction system of this invention not only achieves catalytic wet oxidation treatment of high-content organic wastewater but also realizes comprehensive heat utilization, further reducing wastewater treatment costs.

[0060] (2) The heat extraction module of this invention features high heat transfer efficiency, high pressure resistance, and corrosion resistance. Furthermore, by installing the heat extraction module within the reactor, this invention stabilizes the reactor temperature, ensuring that the TOC of the effluent from the catalytic wet oxidation reactor meets the target, and providing a favorable guarantee for the safe and stable operation of the reactor. Simultaneously, the control system of this invention can automatically control the flow rate of the heat extraction medium in the heat extraction module to ensure temperature stability within the reactor. The heat extraction medium carries heat to the steam generator, which is designed with pressure self-control. Its pressure and steam generation form a control loop; when the heat extraction medium carries more heat, the steam generation increases, and the resulting heat is removed immediately.

[0061] (3) The heat extraction module of the present invention can also input heat into the reactor. When the temperature inside the reactor is low, heat can be input into the heat extraction module through the steam generated by the steam generator to increase the reaction temperature to a suitable reaction temperature, thereby increasing the rate of wet oxidation reaction and ensuring the effect of wet oxidation reaction. Attached Figure Description

[0062] Figure 1 This is a schematic diagram of the wastewater treatment system of the present invention;

[0063] Figure 2 This is a schematic diagram of the reactor structure;

[0064] Figure 3 This is a top view of the heat extraction module;

[0065] Figure 4 This is a cross-sectional view of the heat extraction module;

[0066] Figure 5 for Figure 4 A magnified view of part A in the middle;

[0067] The reference numerals in the accompanying figures have the following meanings:

[0068] 1-High-pressure pump; 2-Preheater; 3-Heater; 4-Reactor; 5-Heat extraction module; 51-Heat extraction medium inlet; 52-Heat extraction medium outlet; 53-Through hole; 54-Inspection channel; 55-Cover plate; 6-Air inlet unit; 7-Gas distributor; 8-Heat transfer oil pump; 9-Steam generator; 10-Safety valve; 11-Gas-liquid separator; 12-Top condenser; 13-Transfer pump; 14-Overheat shut-off valve; 15-Shut-off valve; 16-Feeding unit. Detailed Implementation

[0069] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0070] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0071] Example 1

[0072] Reference Figure 1 A catalytic wet oxidation reaction system, which includes a reactor 4, and a heat extraction module 5 is installed inside the reactor 4.

[0073] Reactor

[0074] Reference Figure 2 Multiple heat collection modules 5 are axially arranged inside the reactor 4. Preferably, multiple heat collection modules 5 are axially arranged inside the reactor 4. For example, 1-8 heat collection modules 5 are evenly spaced axially inside the reactor 4. Preferably, the height distance between two adjacent heat collection modules 5 is 1800-2200 mm.

[0075] By axially arranging multiple heat extraction modules 5 inside reactor 4, precise temperature control inside the reactor can be ensured, allowing for timely adjustment of the temperature in each section of reactor 4 based on the reaction effect.

[0076] Reactor 4 also includes an inlet unit 6, an outlet unit, a feed unit 16, a discharge unit, and an instrumentation unit required for the catalytic wet oxidation reaction.

[0077] In this embodiment, the air inlet unit 6 and the air outlet unit can be used to introduce oxygen and / or air to achieve the catalytic wet oxidation reaction. The feed unit 16 can be used to introduce wastewater that needs to be treated, and the discharge unit can be used to discharge reaction products or unwanted residues. The instrumentation unit can be used to display or monitor the process parameters of the reactor.

[0078] [Heat Extraction Module]

[0079] Reference Figure 3-5 The heat-collecting module 5 is coaxially located inside the reactor 4. The thickness of a single heat-collecting module 5 is 60-200 mm, for example, 150 mm. The outer diameter of the heat-collecting module 5 is slightly smaller than the inner diameter of the reactor 4. For example, the ratio of the outer diameter of the heat-collecting module 5 to the inner diameter of the reactor 4 is infinitely close to 1:1.

[0080] The heat extraction module 5 is provided with a heat exchange chamber and a heat extraction medium inlet 51 and a heat extraction medium outlet 52 connecting the heat exchange chamber. The heat extraction module 5 is provided with multiple channels along its thickness direction, spaced apart from the heat exchange chamber, for radial flow of materials in the reactor 4. The multiple channels for radial flow of materials in the reactor 4, spaced apart from the heat exchange chamber, are evenly spaced.

[0081] The heat exchange cavity is divided into multiple spaces along its thickness direction. Adjacent spaces are connected by through holes 53. The heat exchange medium inlet 51 and the heat exchange medium outlet 52 are respectively connected to the spaces located at both ends of the multiple spaces. Preferably, adjacent through holes 53 are arranged radially opposite each other.

[0082] The heat extraction medium is preferably a heat-conducting medium, such as water or heat-conducting oil.

[0083] The heat extraction module 5 can operate under high temperature and high pressure, and can withstand a single-sided high pressure difference, thus greatly improving the safety of the reaction. At the same time, the heat extraction module 5 can ensure uniform heat extraction in the reactor 4, and also ensure a good construction and maintenance environment.

[0084] Through hole

[0085] The diameter of all through holes 53 can be 2-8mm, with 5mm being an example.

[0086] The total cross-sectional area of ​​all through holes 53 is 0.1%-1% of the cross-sectional area of ​​the heat exchange cavity, for example 0.1%, 0.2%, 0.5%, 0.8%, and 1%.

[0087] [Inspection Channel]

[0088] The heat extraction module 5 also has an inspection channel 54 in the middle. Preferably, the inspection channel 54 is provided with a movable cover plate 55. Preferably, the cover plate 55 is square. For example, the side length of the cover plate 55 is 500-700mm.

[0089] The heat extraction module 5 of this invention combines the functions of heat exchange and trays, achieving the goal of reducing the number of internal components in the reactor 4 and saving costs. The heat extraction module 5 has through holes 53 that allow the material in the reactor 4 to flow axially from bottom to top. It can also redistribute the material to prevent short circuits. Furthermore, a maintenance passage 54 is reserved in the center of the heat extraction module 5. The maintenance passage 54 is designed with a cover plate 55, which allows for easy access for personnel when maintenance is needed.

[0090] Gas distributor

[0091] The reactor 4 is equipped with a gas distributor 7, which is located at the bottom of the lowest heat extraction module 5. The gas distributor 7 can generate a large number of millimeter-sized bubbles, which enhances the mass transfer process during the reaction, facilitates the formation of more free radicals, and promotes the efficient progress of the oxidation reaction. In the same residence time, it can effectively reduce the TOC content in the wastewater to ensure the effluent quality of the reactor 4.

[0092]

Control System

[0093] The catalytic wet oxidation reaction operates under high temperature, high pressure, and acidic conditions. To ensure reaction safety, the reaction system is equipped with a DCS (Distributed Control System) and a SIS (Safety Instrumented System). The control systems can control the flow rate of the feed wastewater to the catalytic wet oxidation reactor. A flow meter controls the frequency conversion of the reactor feed high-pressure pump, thus controlling the flow rate. The pH value of the feed water is used to control the amount of acid added to the catalyst (e.g., copper chloride) solution, thereby adjusting the pH value of the reactor feed. The concentration of copper ions in the feed water is detected to control the amount of catalyst (copper chloride) solution added, thus adjusting the catalyst content in the reactor. A flow meter in the reactor air intake system is used to adjust the opening of the air intake regulating valve, thereby regulating the flow rate of oxygen or air entering the reactor. The steam pressure of the heater is controlled to regulate the flow rate of the feed water. The steam flow rate entering the heater controls the temperature of the wastewater fed into the reactor. A pressure gauge at the top of the reactor controls the opening of the pressure-reducing valve before the gas-liquid separator in the reactor's outlet pipe, thus regulating the reactor pressure. Multiple thermometers mounted axially on the reactor control the flow rate of the heat-extracting medium in each corresponding heat-extracting module, controlling the reactor temperature. The temperature detected by the thermometers and the flow rate of the heat-extracting medium in the heat-extracting module form a control loop. Simultaneously, the flow meter and the heat-extracting medium flow regulating valve of the heat-extracting module form another control loop, ultimately regulating the flow rate of the heat-extracting medium between two adjacent heat-extracting modules within the reactor, thereby stabilizing the reactor temperature. Furthermore, the DCS control system can control the flow rate of the heat-extracting medium in the lower heat-extracting module via thermometers or selectively control the flow rate of the heat-extracting medium in the upper heat-extracting module. By selecting the control loop, the flow rate of the heat-extracting medium in two adjacent heat-extracting modules can be controlled.

[0094] The reaction system also includes alarms for temperature, pressure, flow rate, pH value, and catalyst concentration. When a level one alarm is triggered, the DCS control system will issue an audible and visual alarm to alert operators to intervene and adjust as soon as possible. When a level two alarm is triggered, related equipment or valves will be interlocked to ensure safety. The instrumentation unit includes a temperature sensor, a pressure sensor, an online TOC analyzer, an online pH meter, an online copper ion detector, and a liquid level sensor. Preferably, the temperature sensor, pressure sensor, and liquid level sensor are interlocked.

[0095] When the pressure sensor detects that the pressure inside reactor 4 exceeds the preset pressure, the reactants are released into the gas-liquid separator 11 through the safety valve. The water vapor flashed out of the gas-liquid separator 11 forms a liquid phase through the condenser 12 at the top of the tank and is sent to the subsequent processing stage. When the temperature sensor detects that reactor 4 exceeds the preset reaction temperature, the over-temperature shut-off valve 14 is opened to introduce low-temperature wastewater into reactor 4 to cool it down, while simultaneously shutting off the reactor gas feed valve. When the flow sensor detects that the liquid phase flow in reactor 4 is interrupted, the gas phase inlet pipe shut-off valve 15 of reactor 4 is interlocked and closed to ensure reaction safety. Alternatively, when the reactor pressure exceeds the set value, the reactor gas intake system is forcibly stopped to achieve the purpose of safe production. The DCS control system and the SIS control system are also equipped with independent UPS power supplies to ensure that the system can still detect and control the device in the event of an unexpected power outage.

[0096] The DCS control system includes detection instruments, cards (used to acquire signals from the detection instruments and output analog or digital signals to the actuators), instrument transmission network, and control station; the detection instruments include thermometers, pressure gauges, and flow meters.

[0097] [Feeding Unit]

[0098] The feeding unit 16 includes a wastewater storage unit and a conveying unit. For example, the wastewater storage unit is a wastewater storage tank; the conveying unit is a high-pressure pump 1.

[0099] The reaction system also includes a preheater 2 and a heater 3 connected in series with the feed unit 16. The outlet of the heater 3 is connected to the inlet of the reactor 4. The heater 3 can also use external steam to heat the wastewater.

[0100] The feeding unit also includes a catalyst inlet. For example, the catalyst is a catalyst known in the art for use in catalytic wet oxidation processes, preferably a copper-containing catalyst. An example is copper chloride.

[0101] Steam generator

[0102] The reaction system also includes a steam generator 9, the inlet of which is connected to the heat exchange medium outlet 52 of the heat exchange module 5, and the outlet of which is connected to the heat exchange medium inlet 51 of the lowest heat exchange module 5 in the reactor 4.

[0103] The steam generator 9 of this invention can achieve automatic control of steam pressure and automatically adjust the steam flow rate according to the amount of heat obtained from the reaction. The bottom of the reactor 4 is the start-up stage of the reaction. The heat removed from the reactor can be used to generate steam through the steam generator 9. Part of the generated steam can be used to heat the bottom heat extraction module 5, thereby increasing the speed of the wet oxidation reaction and ensuring the effect of the wet oxidation reaction.

[0104] Steam generator 9 achieves superheated water flash evaporation to produce steam, and can also extract superheated water. The reaction heat from the extracted hot water at the heat extraction medium outlet 52 raises the water temperature in steam generator 9, forming steam. When the steam pressure exceeds the preset pressure of steam generator 9, the steam is discharged into the steam network through pipes. After the steam is discharged, the pressure inside steam generator 9 decreases, and the supply of steam to the steam network stops. When the hot water level in steam generator 9 is high, hot water can be directly extracted from the bottom of steam generator 9 for use in other devices to further recover heat. The extracted hot water continuously extracts heat from the reactor, causing the temperature of the extracted hot water to rise, which in turn increases the pressure inside steam generator 9, resulting in the discharge of steam, and this cycle repeats continuously.

[0105] According to an embodiment of the present invention, the steam generator 9 is equipped with a level gauge. When the water level in the steam generator 9 rises, the drain valve is automatically opened to discharge hot water.

[0106] [Reaction Waste Heat Recovery Unit]

[0107] In this invention, after the high-temperature material from the reactor 4 has completed the reaction, it passes through the preheater 2 and exchanges heat with the low-temperature material in the preheater 2. This causes the temperature of the low-temperature material to be preheated in the preheater to rise, while the temperature of the material exiting the reactor decreases, so as to further recover the waste heat of the material and thus realize the full utilization of the reaction heat energy.

[0108] Gas-liquid separation unit

[0109] The reaction system also includes a gas-liquid separator 11, which is connected to the preheater 2. The reactor 4 of this invention is equipped with a safety valve or rupture disc, etc. If an overpressure risk occurs in the reactor 4, the material is automatically released into the gas-liquid separator 11. The high-temperature gas passes through the gas-liquid separator 11 and enters the top condenser 12, where it is condensed into liquid and flows by gravity into the gas-liquid separator 11. The liquid in the gas-liquid separator 11 is pumped to the post-treatment unit for further purification and recovery of metal ions in the wastewater.

[0110] In this invention, after the reaction is completed, the material exiting reactor 4 passes through a preheater to further recover the waste heat, and then enters the gas-liquid separator 11 after pressure reduction. The partially vaporized liquid in the gas-liquid separator 11 is condensed by a condensation unit (such as a top condenser 12) at the top of the separator and then returned to the gas-liquid separator. It is then pumped to a post-treatment unit for further purification and recovery of metal ions in the wastewater. The non-condensable gas is sent to the tail gas treatment unit for further processing.

[0111] [Condensation Unit]

[0112] The reaction system also includes a condensation unit, which is connected to the gas outlet of the gas-liquid separator 11.

[0113] Post-processing unit

[0114] The reaction system also includes a post-treatment unit connected to the liquid outlet of the gas-liquid separator 11. This post-treatment unit is used for further purification and recovery of metal ions from the wastewater.

[0115] Exhaust gas treatment unit

[0116] The reaction system also includes an exhaust gas treatment unit, which is connected to the non-condensable gas outlet of the gas-liquid separator 11.

[0117] The working process of the reaction system of this invention is as follows: After adding a catalyst to the wastewater containing organic matter, the catalyst concentration and the pH value of the wastewater are adjusted to suitable levels. A high-pressure pump 1 transports the wastewater to be treated to a preheater 2, where the low-temperature wastewater to be treated and the treated high-temperature wastewater exchange heat. The cooled high-temperature wastewater, after being depressurized by a pressure-reducing valve, enters a gas-liquid separator 11. The low-temperature wastewater, after heat exchange, reaches a certain temperature and then enters a heater 3. The heater 3 automatically supplements the heat according to the temperature of the preheated wastewater and the set heating temperature, raising the temperature of the wastewater to be treated to the set temperature. The heated wastewater enters a reactor 4, while a certain proportion of high-pressure pure oxygen or a corresponding proportion of air is introduced. The gas, after passing through a gas distributor 7, forms millimeter-sized microbubbles, enhancing the heat transfer of the reaction. The hydroxyl radicals formed in the reactor 4 gradually break down the organic matter in the wastewater, and as the reaction time progresses, carbon dioxide, water, other salts, and trace amounts of small-molecule organic matter are formed. The reaction releases heat, raising the temperature of the material in reactor 4 to approximately 270-280°C, facilitating the rapid catalytic wet oxidation reaction. When the organic content in reactor 4 is high, more heat is released, and higher material temperatures exacerbate corrosion of the reactor 4 material. Simultaneously, the reaction pressure within reactor 4 increases, posing operational safety risks and increasing operating costs. In this situation, the DCS control system sets the temperature between adjacent heat extraction modules 5 within reactor 4 to a suitable level. As the temperature rises, the thermometer, through control logic, signals the heat extraction medium flow regulating valve to increase its opening, thereby increasing the flow rate of the heat extraction medium at the inlet 51 of heat extraction module 5. This ensures timely and uniform removal of the reaction heat, and the heat extraction medium at the outlet 52 carries the heat to the steam generator 9. The steam generator 9 features automatic pressure control, and the steam outlet is equipped with a flow meter and regulating valve. The water extraction pipeline also features a flow meter and regulating valve. By controlling the steam generation rate and water flow rate, the steam generator 9 achieves automatic pressure control, automatic liquid level control, and automatic steam flow control. A portion of the steam produced by steam generator 9 can be used to supplement heater 3 to heat the wastewater, while the remaining steam is sent to the pipeline network. The wastewater after the reaction enters preheater 2 for cooling. After cooling, the wastewater, after pressure reduction, enters gas-liquid separator 11. Water vapor and non-condensable gases in gas-liquid separator 11 enter condenser 12 at the top of the tank. The liquid phase condenses and flows back into gas-liquid separator 11, while the non-condensable gases enter the waste gas treatment unit. The liquid phase in gas-liquid separator 11 is pumped to the post-treatment unit for further purification of metal ions, ultimately reaching a level suitable for use in the caustic soda plant. Reactor 4 is also equipped with interlocking devices for temperature, pressure, and liquid flow interruption.When the pressure inside reactor 4 exceeds the preset pressure, the reactants are released into the gas-liquid separator 11 through the safety valve. The water vapor that flashes out of the gas-liquid separator 11 forms a liquid phase through the condenser 12 on the top of the tank and goes to the subsequent processing steps. When reactor 4 exceeds the preset reaction temperature, the over-temperature shut-off valve 14 can be opened to introduce low-temperature wastewater into reactor 4 to cool it down. When the liquid phase flow in reactor 4 is interrupted, the gas phase inlet pipe shut-off valve 15 of reactor 4 is interlocked and closed to ensure reaction safety.

[0118] Example 2

[0119] In the reaction system of Example 1 (wherein: five heat-extracting modules 5 are evenly spaced axially within reactor 4, with a heat-extracting thickness of 150 mm, and the height distance between two adjacent heat-extracting modules 5 is 2.2 meters. The heat exchange chamber is divided into multiple spaces along the thickness direction, and two adjacent spaces are connected by through holes 53. The heat-extracting medium inlet 51 and the heat-extracting medium outlet 52 are respectively connected to the spaces located at both ends of the multiple spaces. Two adjacent through holes 53 are arranged radially opposite each other, and the total number of through holes 53 is 1150, with a diameter of 5 mm), the flow rate of a certain pesticide wastewater is 25 t / h, the wastewater flow velocity in the reactor is 0.09 m / min, and the sodium chloride mass concentration in the wastewater is 20%. The total organic matter (TOC) content in the reactor is 9000 ppm. The inlet temperature of reactor 4 is 230℃, the maximum temperature of reactor 4 is 280℃, the maximum pressure of reactor 4 is 7 MPa, the oxygen consumption is 670 kg / h, the catalyst used is copper chloride with a mass concentration of approximately 1500 ppm, the pH value of the wastewater is 1.2, and the organic matter content in the water after the reaction is 6.8 ppm. During the reaction, the hot water inlet flow rate of heat extraction module 5 is automatically controlled. After the reaction starts, the reactor temperature gradually rises. When the reaction temperature reaches above 280℃, the opening of the hot water valve of the second heat extraction module 5 (counting upwards from the bottom of reactor 4) gradually opens, and the hot water flow rate gradually increases to 3.8 m³ / h. 3The hot water temperature rises from 25℃ to 207℃ per hour, ultimately producing 0.59 tons of 130℃ steam and 3.21 tons of 130℃ hot water. When the reaction temperature reaches above 280℃ again, the hot water valve of the third heat extraction module 5 counting upwards from the bottom of reactor 4 gradually opens, and the hot water flow rate gradually increases to 1.9 m³ / h. The hot water temperature rises from 25℃ to 207℃, ultimately producing 0.3 tons of 130℃ steam and 1.6 tons of 130℃ hot water. Finally, the temperature of reactor 4 stabilizes at around 280℃, and the hot water valves of heat extraction modules 5 above the third level remain closed. The effluent from reactor 4 (TOC content of 6.8 ppm) decreases to 80℃ after passing through preheater 2, and the feed water temperature of reactor 4 increases from 30℃ to 200℃. External steam is introduced into heater 3, raising the inlet material temperature of reactor 4 to 230℃. During the entire reaction process, 0.89 t / h of steam with a heat of about 2400 MJ / h was generated by the exothermic reaction; 4.81 tons of hot water at 130℃ were generated with a heat of about 4063 MJ / h; the high-temperature water after the reaction and the low-temperature water in the reactor feed exchanged heat, and 14888 MJ / h of waste heat was reused.

[0120] This embodiment saves 21351 MJ / h of thermal energy, which greatly conserves energy and generates significant economic benefits. Throughout the entire operation, the highest temperature of reactor 4 remains stable at the preset value, and the heat extraction module operates stably.

[0121] Comparative Example 1

[0122] In the reaction system of Example 1 (wherein: 5 heat exchange modules 5 are axially spaced evenly in reactor 4, with a height distance of 2.2 meters between adjacent heat exchange modules 5. The heat exchange chamber is divided into multiple spaces along the thickness direction, and adjacent spaces are connected by through holes 53. The heat exchange medium inlet 51 and heat exchange medium outlet 52 are respectively connected to the spaces located at both ends of the multiple spaces. Adjacent through holes 53 are arranged radially opposite each other, with a total of 1150 through holes 53 and a diameter of 5 mm. The heat exchange modules of reactor 4 were not turned on during this experiment. The flow rate of a certain pesticide wastewater is 25 t / h, the wastewater flow velocity in the reactor is 0.09 m / min, the sodium chloride mass concentration in the wastewater is 20%, and the TOC content in the wastewater is 9000 ppm. The reaction... The inlet temperature of the reactor was 230℃, the highest temperature of the reactor was 280℃, the highest pressure of reactor 4 was 7MPa, the oxygen consumption was 670kg / h, the catalyst used was copper chloride with a mass concentration of approximately 1500ppm, and the pH of the wastewater was 1.2. After the reaction started, the temperature of reactor 4 rapidly rose to 280℃. To ensure the safety of the reaction, the overheat shut-off valve 14 was quickly opened to introduce low-temperature wastewater into reactor 4 at a constant flow rate of 15t / h to cool it down. Due to the addition of a large amount of low-temperature water, the temperature of reactor 4 fluctuated, especially at the bottom of the reactor where the temperature dropped below 200℃. This caused a decrease in the rate of catalytic wet oxidation and a shift in the reaction position upwards. Ultimately, the TOC content at the outlet of reactor 4 was approximately 703.5ppm.

[0123]

[0124] Example 3

[0125] In the reaction system of Example 1 (wherein: eight heat exchange modules 5 are axially spaced evenly in reactor 4, with a height distance of 2.0 meters between adjacent heat exchange modules 5; the heat exchange chamber is divided into multiple spaces along the thickness direction, and adjacent spaces are connected by through holes 53; the heat exchange medium inlet 51 and heat exchange medium outlet 52 are respectively connected to the spaces located at both ends of the multiple spaces; adjacent through holes 53 are arranged radially opposite each other, and the total number of through holes 53 is 1350, with a diameter of 5 mm), a certain chemical wastewater contains chlorinated... The sodium concentration was 18%, the TOC content in the wastewater was 13000 ppm, the inlet temperature of reactor 4 was 220℃, the maximum temperature of reactor 4 was 280℃, the maximum pressure of reactor 4 was 7 MPa, the oxygen consumption was 853 kg / h, the catalyst used was copper chloride with a catalyst concentration of about 2000 ppm, the pH value of the wastewater was 1.0, the influent flow rate of reactor 4 was 45 t / h, the wastewater flow velocity in the reactor was 0.14 m / min, and the organic matter content in the water after the reaction was 7.2 ppm. After the reaction begins, the reactor temperature gradually rises. When the reaction temperature reaches above 280℃, the hot water valve of the third heat extraction module 5 (counting upwards from the bottom of reactor 4) gradually opens, increasing the hot water flow rate to 3.8 m³ / h and the hot water temperature from 30℃ to 212℃, ultimately producing 0.63 tons of 130℃ steam and 3.18 tons of 130℃ hot water. Similarly, the hot water valve of the fourth heat extraction module 5 (counting upwards from the bottom of reactor 4) gradually opens, increasing the hot water flow rate to 3.0 m³ / h and the hot water temperature from 30℃ to 207℃, ultimately producing 0.47 tons of 130℃ steam and 2.53 tons of 130℃ hot water. Finally, the hot water valve of the fifth heat extraction module 5 (counting upwards from the bottom of reactor 4) gradually opens, increasing the hot water flow rate to 1.0 m³ / h. 3 The hot water temperature rises from 30℃ to 207℃ per hour, ultimately producing 0.16 tons of 130℃ steam and 0.84 tons of 130℃ hot water. The final temperature of reactor 4 stabilizes at around 280℃, and the hot water valves of heat extraction modules 5 above the fifth block remain closed. The effluent from reactor 4 (TOC content 7.2ppm) decreases to 85℃ after passing through preheater 2, while the feed water temperature rises from 35℃ to 202℃. External steam is introduced into heater 3, raising the inlet material temperature of reactor 4 to 220℃. Throughout the reaction process, 1.26 t / h of 130℃ steam is generated using the exothermic reaction, producing approximately 3430 MJ / h of heat; 6.55 t / h of 130℃ hot water is generated, producing approximately 5532 MJ / h of heat; the high-temperature water after the reaction exchanges heat with the low-temperature feed water of the reactor, utilizing 26403 MJ of waste heat again.

[0126] This embodiment saves 35365 MJ / h of thermal energy. Throughout the entire operation, the highest temperature of the reactor remains stable at the preset value, and the reaction heat extraction system operates stably.

[0127] Comparative Example 2

[0128] In the reaction system of Example 1 (wherein: 8 heat exchange modules 5 are axially spaced evenly in reactor 4, with a height distance of 2.0 meters between adjacent heat exchange modules 5. The heat exchange chamber is divided into multiple spaces along the thickness direction, and adjacent spaces are connected by through holes 53. The heat exchange medium inlet 51 and heat exchange medium outlet 52 are respectively connected to the spaces located at both ends of the multiple spaces. Adjacent through holes 53 are arranged radially opposite each other, with a total of 1350 through holes 53 and a diameter of 5 mm. During this experiment, the heat exchange modules 5 of reactor 4 were not turned on. A certain chemical wastewater has a sodium chloride mass concentration of 18% and a TOC content of 13000 ppm. The inlet temperature of reactor 4 is 220℃, the highest temperature of reactor 4 is 280℃, and the highest pressure of reactor 4 is... The pressure was 7 MPa, the oxygen consumption was 853 kg / h, the catalyst was copper chloride with a mass concentration of approximately 2000 ppm, the pH of the wastewater was 1.0, the influent flow rate of reactor 4 was 45 t / h, and the wastewater flow rate in the reactor was 0.14 m / min. After the reaction started, the temperature of reactor 4 rapidly rose to 280℃. To ensure reaction safety, the overheat shut-off valve 14 was quickly opened to introduce low-temperature wastewater into reactor 4 at a constant flow rate of 25 t / h to cool it down. Due to the rapid overheating and the addition of a large amount of low-temperature water, the temperature of reactor 4 fluctuated, especially at the bottom, where the temperature dropped below 130℃. This caused a decrease in the rate of catalytic wet oxidation and a shift in the reaction position. Ultimately, the TOC content at the outlet of reactor 4 was approximately 3768.2 ppm.

[0129]

[0130] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for wastewater treatment, characterized in that, This includes a catalytic wet oxidation reaction system, in which wastewater undergoes a catalytic wet oxidation reaction to achieve wastewater purification; The catalyst used in the catalytic wet oxidation reaction is a copper-containing catalyst; The reaction system includes a reactor, and multiple heat collection modules are arranged axially and coaxially inside the reactor, with the heat collection modules located concentrically inside the reactor; The heat extraction module is provided with a heat exchange chamber and a heat extraction medium inlet and a heat extraction medium outlet that connect to the heat exchange chamber. The heat extraction module is also provided with multiple channels along the thickness direction that are spaced apart from the heat exchange chamber for radial flow of wastewater in the reactor. The plurality of channels for radial flow of wastewater in the reactor, which are spaced apart from the heat exchange chamber, are evenly spaced. The heat exchange cavity is divided into multiple spaces along the thickness direction. Adjacent spaces are connected by through holes. The heat exchange medium inlet and heat exchange medium outlet are respectively connected to the spaces located at both ends of the multiple spaces. Adjacent through holes are arranged radially opposite to each other. The reactor is also equipped with a gas distributor, which is located at the bottom of the lowest heat extraction module. The reaction system also includes a steam generator, the inlet of which is connected to the heat exchange medium outlet of the heat exchange module; the outlet of the steam generator is connected to the heat exchange medium inlet of the lowest heat exchange module in the reactor. The reaction system also includes a DCS control system and a SIS control system; The heat extraction module serves both as a heat exchanger and as a tray in the reactor.

2. The method as described in claim 1, characterized in that... The outer diameter of the heat extraction module is smaller than the inner diameter of the reactor.

3. The method as described in claim 2, characterized in that, The ratio of the outer diameter of the heat extraction module to the inner diameter of the reactor is (0.95~1):

1.

4. The method according to any one of claims 1-3, characterized in that, The total cross-sectional area of ​​all through holes is 0.1%-1% of the cross-sectional area of ​​the heat exchange cavity; And / or, the diameter of all through holes is 2-8mm.

5. The method according to any one of claims 1-3, characterized in that, The heat extraction module is also provided with an inspection channel in the middle, and the inspection channel is provided with a movable cover plate; The cover plate is square, and the side length of the cover plate is 500-700mm.

6. The method according to any one of claims 1-2, characterized in that, One to eight heat collection modules are axially arranged inside the reactor, and multiple heat collection modules are evenly spaced axially inside the reactor. And / or, the height distance between two adjacent heat extraction modules is 1800-2200mm; And / or, the thickness of the heat extraction module is 60-200mm.

7. The method according to any one of claims 1-3, characterized in that, The reactor is also equipped with a catalyst recovery unit.

8. The method according to any one of claims 1-3, characterized in that, The reactor also includes an inlet unit, an outlet unit, a feed unit, a discharge unit, and an instrumentation unit required for the catalytic wet oxidation reaction; The instrument unit includes a temperature sensor, a pressure sensor, and a liquid level sensor, which are interlocked.

9. The method as described in claim 8, characterized in that, The reaction system also includes a preheater and a heater connected in series with the feeding unit, the outlet of which is connected to the inlet of the reactor.

10. The method according to any one of claims 1-3, characterized in that, The steam generator is equipped with a distributor; The steam generator is equipped with a level gauge.

11. The method as described in claim 9, characterized in that, The reaction system also includes a gas-liquid separator, which is connected to a preheater.

12. The method as described in claim 11, characterized in that, The reaction system also includes a condensation unit, which is connected to the gas outlet of the gas-liquid separator.

13. The method as described in claim 11, characterized in that, The reaction system also includes a post-processing unit, which is connected to the liquid outlet of the gas-liquid separator.

14. The method as described in claim 11, characterized in that, The reaction system also includes an exhaust gas treatment unit, which is connected to the non-condensable gas outlet of the gas-liquid separator.

15. The method as described in claim 1, characterized in that, The operating temperature of the reactor is between 150-300℃; And / or, during the catalytic wet oxidation reaction, the pH value of the wastewater is 0.8-1.4; And / or, the copper ion content is between 1000-3000 ppm; And / or, the TOC content in the wastewater is 1000-50000 ppm; And / or, in the catalytic wet oxidation reaction, the flow rate of the heat medium inlet is 1~3m / s; And / or, in the catalytic wet oxidation reaction, the flow rate at the outlet of the heat transfer medium is 1~3m / s; And / or, in the catalytic wet oxidation reaction, the inlet flow rate of the wastewater is 1-2 m / s; And / or, in the catalytic wet oxidation reaction, the flow rate of wastewater in the reactor is 0.05-0.2 m / min.

16. A method for co-producing steam using catalytic wet oxidation, characterized in that, This method employs a catalytic wet oxidation reaction system; The reaction system includes a reactor, and multiple heat collection modules are arranged axially and coaxially inside the reactor, with the heat collection modules located concentrically inside the reactor; The heat extraction module is provided with a heat exchange chamber and a heat extraction medium inlet and a heat extraction medium outlet that connect to the heat exchange chamber. The heat extraction module is also provided with multiple channels along the thickness direction that are spaced apart from the heat exchange chamber for radial flow of wastewater in the reactor. The plurality of channels for radial flow of wastewater in the reactor, which are spaced apart from the heat exchange chamber, are evenly spaced. The heat exchange cavity is divided into multiple spaces along the thickness direction. Adjacent spaces are connected by through holes. The heat exchange medium inlet and heat exchange medium outlet are respectively connected to the spaces located at both ends of the multiple spaces. Adjacent through holes are arranged radially opposite to each other. The reactor is also equipped with a gas distributor, which is located at the bottom of the lowest heat extraction module. The reaction system also includes a steam generator, the inlet of which is connected to the heat exchange medium outlet of the heat exchange module; the outlet of the steam generator is connected to the heat exchange medium inlet of the lowest heat exchange module in the reactor. The reaction system also includes a DCS control system and a SIS control system; The heat extraction module serves both as a heat exchanger and as a tray in the reactor. The method for co-producing steam includes a catalytic wet oxidation reaction system in which wastewater undergoes a catalytic wet oxidation reaction in a reactor, and steam is co-produced in a steam generator using the heat released from the catalytic wet oxidation reaction. The catalyst used in the catalytic wet oxidation reaction is a copper-containing catalyst.

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