Combined VOCs catalytic oxidation treatment method and system and application

Abstract

The invention belongs to the technical field of organic waste gas treatment, and discloses a combined VOCs catalytic oxidation treatment method and system and application, the treatment method comprises the following steps: 1) VOCs gas enters a condensation tank, part of the VOCs gas is condensed into a liquid phase to be stored in the condensation tank, and the uncondensed part is discharged to a buffer tank; when the liquid in the condensation tank reaches a set liquid level value, the liquid is evaporated into gas which enters the buffer tank; (2) the VOCs gas in the buffer tank is decompressed and then mixed with preheated air in a mixer, and then the mixture enters a catalytic oxidation reactor to react; and 3) cooling the gas obtained by the reaction, and discharging the gas after the gas reaches the standard through concentration detection. According to the treatment method, the applicability of the device can be improved, and the energy consumption and investment cost of the device are effectively reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic waste gas treatment, and particularly relates to a combined VOCs catalytic oxidation treatment method and system and application. BACKGROUND

[0002] Volatile organic compounds (VOCs) refer to organic compounds with high saturated vapor pressure, low boiling point, small molecular weight and easy volatilization at room temperature under standard conditions. Generally, it refers to various organic compounds with a boiling point of 50-260℃ at room temperature. VOCs are generally divided into several categories such as methane hydrocarbons (NMHCs), oxygen-containing organic compounds, halogenated hydrocarbons, nitrogen-containing organic compounds, sulfur-containing organic compounds, etc. Most of them have unpleasant special smell and have toxicity, irritation, teratogenicity and carcinogenicity, and are mainly derived from coal chemical industry, petroleum chemical industry, fuel paint manufacturing, solvent manufacturing and use, etc.

[0003] At present, many provinces and cities in China have issued local control standards related to VOCs emissions. The national standard "Integrated Emission Standard of Air Pollutants" stipulates the emission limits of 33 kinds of air pollutants, and its index system is the maximum allowable emission concentration, the maximum allowable emission rate and the unorganized emission monitoring concentration limit. In the process of environmental monitoring and evaluation, non-methane hydrocarbons (NMHC) as a comprehensive index representing the concentration of VOCs in waste gas is the mainstream of various standards and is widely used in the evaluation of VOCs fixed pollutant total amount control, treatment facility governance efficiency, end emission standard, etc. Non-methane hydrocarbons refer to all carbon hydrocarbons except methane, mainly including alkanes, alkenes, aromatic hydrocarbons and oxygen-containing hydrocarbons. As non-methane hydrocarbons, which are air pollutants, they actually refer to hydrocarbons with C2-C12. According to the current emission standard requirements of Beijing, since January 1, 2018, the maximum allowable emission concentration of non-methane hydrocarbons in the atmospheric pollutants of all new, modified and expanded projects is 50mg / Nm 3 , and the maximum allowable emission concentration limit of non-methane hydrocarbons in semiconductor and electronic product manufacturing industry, pharmaceutical manufacturing industry (except chemical medicine raw material manufacturing) is 20mg / Nm 3 . Waste gas treatment is an important part of environmental protection engineering. The significance and social importance of waste gas treatment cannot be ignored.

[0004] VOCs exhaust pollutants are various in types and different in characteristics. Different types of exhaust gas should be treated by appropriate methods. Commonly used exhaust gas treatment methods include condensation method, absorption method, combustion method, catalytic method, activated carbon adsorption method, biological method, plasma decomposition method, UV method, etc. Condensation method is a method that directs the exhaust gas into a condenser or first absorbs the concentrated exhaust gas by desorption, and then directs it into a condenser. The condensate can be separated to recover valuable organic matter. Absorption method can be divided into chemical absorption and physical absorption. Because the organic exhaust gas contains a large amount of "three benzene" gas, which has low chemical activity, chemical absorption cannot be used. Physical absorption is that one or several components in the exhaust gas are dissolved in the selected liquid absorbent. The absorbent should have high affinity with the absorbed components, low volatility, and small volatility. After the absorption liquid is saturated, it is heated to desorb and then cooled for reuse. Combustion method is a method that uses auxiliary fuel such as gas or oil to heat the mixed gas to a certain temperature (700-800℃) and stay for a certain time (0.3-0.5 seconds) to decompose the combustible harmful substances at high temperature into harmless substances. Catalytic method is a process in which harmful combustible components in exhaust gas are completely oxidized into carbon dioxide and water under the action of a catalyst. Activated carbon adsorption method is a method in which organic exhaust gas is sent into an adsorption bed by an exhaust fan, and the organic exhaust gas is adsorbed by activated carbon adsorbent to purify the gas. The purified gas is discharged into the atmosphere to complete the purification process. Biological method is a method in which microorganisms decompose organic components as carbon source and energy. Plasma decomposition method is a waste gas treatment method in which a large number of energy-carrying electrons produced by dielectric discharge under the action of an external electric field bombard pollutant molecules, causing a series of complex physical and chemical reactions, so that the pollutants are degraded and removed. UV method is a method that uses a specially designed high-energy ozone UV light beam to irradiate the exhaust gas, changes the molecular structure of the exhaust gas, and makes the organic or inorganic polymer waste gas compounds degrade into low molecular compounds under the irradiation of high-energy UV light beam.

[0005] The experimental device of polyolefin, especially the pilot plant, produces high-concentration exhaust gas with the characteristics of easy condensation, high concentration, and intermittent discharge. According to these characteristics, condensation method, absorption method, combustion method, catalytic method, activated carbon adsorption method, biological method, plasma decomposition method, and UV method have certain limitations and inapplicability, and cannot completely treat such working condition exhaust gas normally and efficiently.

[0006] Currently, the treatment is usually carried out in a catalytic way. The waste gas discharged continuously by a conventional device is mixed with air in proportion, preheated by a heat exchanger, and then introduced into a reactor to carry out a chemical reaction under the action of a catalyst. The CO2 and H2O after the reaction are cooled by the heat exchanger and then discharged to the atmosphere at a high point. However, the amount of waste gas discharged intermittently will be relatively large in a short time, and there is almost no waste gas discharged during the non-discharge time. The treatment capacity needs to be set according to the instantaneous maximum discharge amount. If the instantaneous maximum discharge amount is not set, a certain back pressure will be caused to the device venting, which causes the venting waste gas to be unable to be discharged in time, and affects the normal operation of the device. The design of the instantaneous maximum discharge amount will cause a large amount of catalyst to be filled, a large amount of power to be consumed by electric heating, a large area to be occupied by the device, and a high investment cost and catalyst replacement cost. SUMMARY

[0007] For the VOCs waste gas with components prone to condensation, high concentration and intermittent discharge, the purpose of the present application is to provide a combined VOCs catalytic oxidation treatment method and system and application, which combines condensation and catalytic oxidation, can reasonably set the treatment capacity of catalytic oxidation, optimizes the process flow, increases the applicability of the device, and effectively reduces the energy consumption and investment cost of the device.

[0008] The first aspect of the present application provides a combined VOCs catalytic oxidation treatment method, which comprises the following steps:

[0009] 1) VOCs gas enters a condensing tank, part of which is condensed into a liquid phase and stored in the condensing tank, and the uncondensed part is discharged to a buffer tank; when the liquid in the condensing tank reaches a set liquid level value, the liquid is evaporated into gas and enters the buffer tank;

[0010] 2) The VOCs gas in the buffer tank is mixed with preheated air in a mixer after being reduced in pressure, and then enters a catalytic oxidation reactor for reaction;

[0011] 3) The gas obtained by the reaction is cooled and discharged after concentration detection.

[0012] The second aspect of the present application provides a combined VOCs catalytic oxidation treatment system used in the above treatment method, which comprises a condensing tank, a buffer tank, a mixer, an air providing unit and a catalytic oxidation reactor.

[0013] The gas outlet of the condensing tank is connected with the gas inlet of the buffer tank, the liquid outlet of the condensing tank is connected with the feed inlet of the buffer tank through an air temperature type low-temperature vaporizer, and the gas outlet of the buffer tank is connected with the feed inlet of the catalytic oxidation reactor through the mixer;

[0014] The gas outlet of the air providing unit is connected with the feed inlet of the catalytic oxidation reactor through the mixer;

[0015] The outlet of the catalytic oxidation reactor is connected with a condensing unit.

[0016] The third aspect of the present application provides application of the above-mentioned treatment method and treatment system in catalytic oxidation treatment of VOCs gas discharged intermittently.

[0017] Compared with the prior art, the present application has the following beneficial effects:

[0018] (1) The treatment method of the present application is suitable for VOCs waste gas with components prone to condensation, high concentration and intermittent discharge. According to the working condition of waste gas treatment, condensation or catalytic oxidation can be used alone, or the two can be combined for treatment, thereby increasing the applicability of the device and effectively reducing the energy consumption and investment cost of the device.

[0019] (2) The treatment method of the present application comprehensively considers factors such as equipment power consumption, device floor area, catalyst loading amount, investment cost, operation and maintenance convenience on the premise of reasonable treatment capacity and meeting the requirement of standard discharge.

[0020] Other features and advantages of the present application will be described in detail in the subsequent specific embodiment part. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a process flow schematic diagram of a combined VOCs catalytic oxidation treatment system of the present application.

[0022] Explanation of reference signs: 1. Refrigeration unit; 2. Condensing tank; 3. Air temperature type low-temperature vaporizer; 4. Buffer tank; 5. Air filter; 6. Blower; 7. Plate heat exchanger; 8. Electric heating preheater; 9. Flame arrester; 10. Venturi mixer; 11. Catalytic oxidation reactor; 12. Condensing heat exchanger; A. On-off valve; B. On-off valve; C. Regulating valve; D. Regulating valve; E. Pressure reducing valve. DETAILED DESCRIPTION

[0023] The specific embodiment of the present application is described in detail below. It should be understood that the specific embodiment described herein is only used to illustrate and explain the present application, and is not used to limit the present application.

[0024] According to the first aspect of the present application, the present application provides a combined VOCs catalytic oxidation treatment method, which comprises the following steps:

[0025] 1) VOCs gas enters the condensing tank, part of which is condensed into liquid phase and stored in the condensing tank, and the uncondensed part is discharged into the buffer tank; when the liquid in the condensing tank reaches the set liquid level value, the liquid is evaporated into gas and enters the buffer tank;

[0026] 2) The VOCs gas in the buffer tank is mixed with preheated air in a mixer after decompression, and then enters the catalytic oxidation reactor for reaction;

[0027] 3) The gas obtained by reaction is cooled, and discharged after concentration detection.

[0028] According to the present application, the liquid in the condensing tank is evaporated into gas by using ambient temperature through the air temperature type low-temperature vaporizer.

[0029] In the present application, the air is preheated by heat exchange with the gas obtained by reaction and optional electric heating.

[0030] According to the present application, the liquid level value in the condensing tank can be set as needed. Generally, the setting of the liquid level value can realize that the condensing tank collects condensed liquid when VOCs gas is discharged, and the liquid in the condensing tank is gasified and treated when VOCs gas is not discharged.

[0031] The treatment method of the present application adopts the combination of condensation and catalytic oxidation technology. When discharging intermittently, the gas components that can be condensed in the VOCs waste gas are liquefied and stored by the circulation of cooling liquid, and the gas that cannot be condensed is mixed with air in proportion after buffering, and then enters the subsequent catalytic oxidation device for treatment reaction, and finally is discharged up to standard. When not discharging intermittently, the liquefied VOCs waste gas can be reversed gasification, mixed with air in proportion after buffering, and then enters the subsequent catalytic oxidation device for treatment reaction, and finally is discharged up to standard.

[0032] According to a specific embodiment, the treatment method of the present application includes the following flow:

[0033] The VOCs waste gas enters the condensing tank through the venting pipeline. The inside of the tank is provided with U-shaped heat exchange pipes. The cooling capacity provided by the matching refrigerating unit is used to condense the easily condensable volatile organic compounds contained in the discharge gas into liquid phase, and store them in the tank. Part of the non-condensable gas that may be contained in the discharge gas is discharged to the buffer tank through the tank top pipeline.

[0034] When the condensing tank is stored to the set liquid level value, the automatic shut-off valve at the bottom of the condensing tank is opened, the stored liquid enters the air temperature type low-temperature vaporizer, and the liquid is evaporated into gas by using ambient temperature, and is stored in the buffer tank.

[0035] The VOCs gas in the buffer tank is decompressed to a certain pressure value by a pressure reducing valve, and then mixed with preheated air in a Venturi mixer on the air pipeline in a constant flow manner through the metering and control adjustment of the regulating valve and the flow detection, and then enters the catalytic oxidation reactor. The air flow and the VOCs gas flow are proportionally interlocked controlled.

[0036] Based on the feed rate, composition, and safety limits of each VOCs gas, the necessary air for catalytic oxidation is supplied by a blower. The air flow rate is proportionally controlled to maintain the set air-fuel ratio, ensuring complete VOCs catalytic oxidation and system safety. The airflow from the blower is metered by a flow meter, and the flow rate is adjusted by the blower's frequency converter. After detection and adjustment, the air enters a plate heat exchanger for preheating. The preheated air then enters an electric preheater. If the preheated air temperature does not reach the set requirement, the electric preheater is activated, heating the air to the catalytic oxidation reaction temperature before it enters the catalytic oxidation reactor.

[0037] Preheated air from the electric preheater and VOCs gas are mixed in a Venturi mixer before entering the catalytic oxidation reactor. The Venturi mixer ensures that catalytic oxidation treatment can still be carried out even when the VOCs gas pressure is lower than the air pressure. The VOCs gas and air undergo a catalytic oxidation reaction under the action of a catalyst, producing carbon dioxide and water vapor. The high-temperature gas exiting the catalytic oxidation reactor enters a plate heat exchanger to preheat the air through heat exchange. After being water-cooled by a condenser heat exchanger, the gas is discharged after concentration testing confirms compliance with standards.

[0038] The specific process conditions for each step of this invention are not particularly limited. Those skilled in the art can appropriately determine the specific operating conditions and methods based on existing technology, such as catalytic oxidation steps.

[0039] According to a second aspect of the present invention, the present invention provides a combined VOCs catalytic oxidation treatment system used in the above-described treatment method, the treatment system comprising a condenser, a buffer tank, a mixer, an air supply unit, and a catalytic oxidation reactor;

[0040] The gas outlet of the condenser is connected to the gas inlet of the buffer tank, the liquid outlet of the condenser is connected to the feed inlet of the buffer tank through an ambient temperature cryogenic vaporizer, and the gas outlet of the buffer tank is connected to the feed inlet of the catalytic oxidation reactor through a mixer.

[0041] The air outlet of the air supply unit is connected to the feed inlet of the catalytic oxidation reactor via a mixer;

[0042] The outlet of the catalytic oxidation reactor is connected to a condensation unit.

[0043] In this invention, the condenser is provided with a jacket on the outside and a U-shaped heat exchange tube inside the tank, and the jacket and the U-shaped heat exchange tube are connected to a matching refrigeration unit.

[0044] According to the present invention, the condenser is provided with a first liquid level detection device, which is electrically connected to the liquid outlet valve of the condenser; the buffer tank is provided with a second liquid level detection device, which is electrically connected to the feed inlet valve of the buffer tank.

[0045] Preferably, in accordance with the direction of air flow, the air supply unit includes an air filter, a blower, a plate heat exchanger, an electric preheater, and a flame arrester arranged in sequence, and the outlet of the flame arrester is connected to the feed inlet of the catalytic oxidation reactor via a mixer.

[0046] In this invention, the outlet of the electric heating preheater is equipped with a first temperature detection device, which is electrically connected to the heating regulation device of the electric heating preheater.

[0047] According to the present invention, the condensation unit includes a condensation heat exchanger, and the outlet of the catalytic oxidation reactor is connected to the condensation heat exchanger via the plate heat exchanger.

[0048] In this invention, the gas outlet pipeline of the buffer tank is respectively equipped with a pressure reducing valve, a regulating valve, and a first flow detection device, and the regulating valve is electrically connected to the first flow detection device; the blower is equipped with a frequency converter, and the gas outlet pipeline of the blower is equipped with a second flow detection device, and the frequency converter is electrically connected to the second flow detection device; the first flow detection device and the second flow detection device are interlocked.

[0049] According to the present invention, the catalytic oxidation reactor is provided with a second temperature detection device, which is electrically connected to the first temperature detection device and the first flow detection device.

[0050] The electrical connection in this invention refers to the interlocking control and adjustment between the two through a control device, which can be achieved using conventional methods in the prior art.

[0051] The connecting pipelines between the various devices, the material inlets that enable the devices to operate normally, etc., which are not specifically limited in this invention, can all be conventionally set up according to existing technology.

[0052] According to a third aspect of the present invention, the present invention provides the application of the above-described treatment method and treatment system in the catalytic oxidation treatment of intermittently emitted VOCs gas.

[0053] The substances, devices, and process parameters not limited in this invention can be selected according to existing technology and are conventional technical means in this field.

[0054] The present invention will be further described below with reference to embodiments. However, the invention is not limited to these embodiments.

[0055] Example

[0056] use Figure 1 The combined VOCs catalytic oxidation treatment system shown intermittently emits VOCs waste gas from the polyolefin experimental device, which enters the condenser tank 2 through pipelines. The tank is equipped with multiple sets of U-shaped heat exchange tubes according to the different VOCs components being treated. A supporting refrigeration unit 1 provides different low-temperature coolants, which circulate through the U-shaped heat exchange tubes and the condenser tank jacket, condensing easily condensable volatile organic compounds in the exhaust gas into a liquid phase for collection and storage. The non-condensable components in the exhaust gas are transported through a pipeline at the top of the condenser tank 2 to a buffer tank 4 for buffering and pressure stabilization before entering the catalytic oxidation reaction stage.

[0057] When the experimental setup is intermittently emitting VOCs, the liquid level is measured by the first liquid level detection device on the condenser tank 2. If the level is higher than the set value, the control valve A opens, and the liquid phase enters the ambient temperature cryogenic vaporizer 3 for vaporization at the ambient temperature. The gaseous phase then enters the buffer tank 4 through the regulating valve C for buffering and pressure stabilization before proceeding to the catalytic oxidation reaction stage. If the level is lower than the set value, the control valve A closes, and the liquid phase is stored in the condenser tank 2. If the ambient temperature cryogenic vaporizer 3 experiences incomplete vaporization, the liquid phase may be carried into the buffer tank 4. The second liquid level detection device on the buffer tank 4 measures the liquid level. If the level is higher than the set value, the control valve B closes, and the liquid phase in the buffer tank 4 needs to be drained. If the level is lower than the set value, the control valve A opens, and vaporization continues.

[0058] Atmospheric air, after being filtered by air filter 5, is transported by blower 6 through pipes to plate heat exchanger 7 for preheating. The preheated air is then sent to electric preheater 8 for further heating. The air heating temperature is controlled by a first temperature detection device at the outlet of electric preheater 8 and its own heating regulation, forming a PID single-loop control to achieve the reaction set temperature required for catalytic oxidation. The heated air is then thoroughly mixed with VOCs waste gas in venturi mixer 10 via flame arrester 9, and enters catalytic oxidation reactor 11. Under the action of a catalyst, a catalytic oxidation reaction occurs, generating carbon dioxide and water vapor. The high-temperature gas after the reaction enters plate heat exchanger 7, where it exchanges heat with the air at the outlet of blower 6. After the gas cools down, it is further water-cooled by condenser heat exchanger 12, and after passing concentration detection, it is discharged into the atmosphere at a high point.

[0059] The second air flow detection device and the first VOCs flow detection device in the catalytic oxidation reaction process need to be interlocked and controlled according to a certain ratio based on the different VOCs components and concentrations. The detection of the second temperature detection device in the catalytic oxidation reactor 11 directly determines whether the reaction can be completed and whether the emission requirements are met. At the same time, it also needs to take into account the interlocking treatment of both over-temperature and under-temperature abnormal operating conditions.

[0060] Determine the flow ratio relationship between air and VOCs according to the explosion limits of VOC components. Based on the set flow rate of VOCs, determine the set flow rate of air. The VOCs in buffer tank 4 are depressurized by pressure reducing valve E on the outlet pipeline at the top of the tank, and then the flow set value of VOCs is controlled through the PID single loop formed by the first flow detection device and regulating valve D to achieve a throughput matching that of catalytic oxidation reactor 11. The variable frequency speed regulation device supporting blower 6 and the second flow detection device on the outlet pipeline form a PID single loop to control the flow set value of air. The second temperature detection device on catalytic oxidation reactor 11 sets the high limit alarm value and low limit alarm value of the temperature. If it is lower than the low limit alarm value, it indicates that the reaction is incomplete and cannot meet the standard for treatment. It is necessary to increase the set value of the first temperature detection device at the outlet of electric heating preheater 8 and appropriately increase the set value of the first flow detection device for VOCs to reach the temperature range of normal catalytic oxidation reaction. If it is higher than the high limit alarm value, it indicates that there is an over-temperature phenomenon during the reaction process. It is necessary to decrease the set value of the first temperature detection device at the outlet of electric heating preheater 8 and appropriately decrease the set value of the first flow detection device for VOCs to reach the temperature range of normal catalytic oxidation reaction.

[0061] The combined VOCs catalytic oxidation treatment method of the present invention greatly reduces the collection of short-term large air volumes through condensation, reasonably sets the throughput of catalytic oxidation, optimizes the process flow, increases the applicability of the device, and effectively reduces the energy consumption and investment cost of the device.

[0062] The embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is also not limited to the disclosed embodiments. Many modifications and changes are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A combined VOCs catalytic oxidation treatment method, characterized in that, The processing method includes the following steps: 1) VOCs gas enters the condenser, part of which is condensed into liquid and stored in the condenser, while the uncondensed part is discharged to the buffer tank; when the liquid in the condenser reaches the set liquid level, the liquid evaporates into gas and enters the buffer tank. 2) The VOCs gas in the buffer tank is reduced in pressure and mixed with preheated air in a mixer, and then enters the catalytic oxidation reactor for reaction; 3) After the gas obtained from the reaction is cooled, it is discharged after the concentration is detected and meets the standard.

2. The combined VOCs catalytic oxidation treatment method according to claim 1, wherein, The liquid in the condenser is vaporized into gas using an ambient temperature cryogenic vaporizer.

3. The combined VOCs catalytic oxidation treatment method according to claim 1, wherein, The air is preheated by heat exchange with the gas produced in the reaction and by optional electric heating.

4. The combined VOCs catalytic oxidation treatment system used in the treatment method according to any one of claims 1-3, characterized in that, The processing system includes a condenser, a buffer tank, a mixer, an air supply unit, and a catalytic oxidation reactor; The gas outlet of the condenser is connected to the gas inlet of the buffer tank, the liquid outlet of the condenser is connected to the feed inlet of the buffer tank through an ambient temperature cryogenic vaporizer, and the gas outlet of the buffer tank is connected to the feed inlet of the catalytic oxidation reactor through a mixer. The air outlet of the air supply unit is connected to the feed inlet of the catalytic oxidation reactor via a mixer; The outlet of the catalytic oxidation reactor is connected to a condensation unit.

5. The combined VOCs catalytic oxidation treatment system according to claim 4, wherein, The condenser is equipped with a jacket on the outside and a U-shaped heat exchange tube inside. The jacket and the U-shaped heat exchange tube are connected to a matching refrigeration unit.

6. The combined VOCs catalytic oxidation treatment system according to claim 4, wherein, The condenser is equipped with a first liquid level detection device, which is electrically connected to the liquid outlet valve of the condenser; the buffer tank is equipped with a second liquid level detection device, which is electrically connected to the feed inlet valve of the buffer tank.

7. The combined VOCs catalytic oxidation treatment system according to claim 4, wherein, In accordance with the direction of air flow, the air supply unit includes an air filter, a blower, a plate heat exchanger, an electric preheater, and a flame arrester arranged in sequence. The outlet of the flame arrester is connected to the feed inlet of the catalytic oxidation reactor via a mixer. The outlet of the electric heating preheater is equipped with a first temperature detection device, which is electrically connected to the heating regulation device of the electric heating preheater. Preferably, the condensation unit includes a condensation heat exchanger, and the outlet of the catalytic oxidation reactor is connected to the condensation heat exchanger via the plate heat exchanger.

8. The combined VOCs catalytic oxidation treatment system according to claim 4, wherein, The gas outlet pipeline of the buffer tank is equipped with a pressure reducing valve, a regulating valve, and a first flow detection device, and the regulating valve is electrically connected to the first flow detection device; the blower is equipped with a frequency converter, and the gas outlet pipeline of the blower is equipped with a second flow detection device, and the frequency converter is electrically connected to the second flow detection device; the first flow detection device and the second flow detection device are interlocked.

9. The combined VOCs catalytic oxidation treatment system according to claim 7, wherein, The catalytic oxidation reactor is equipped with a second temperature detection device, which is electrically connected to the first temperature detection device and the first flow detection device.

10. The application of the treatment method according to any one of claims 1-3 and the treatment system according to any one of claims 4-9 in the catalytic oxidation treatment of intermittently emitted VOCs gas.

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