Microwave catalysis and plasma combined waste gas treatment system and method

Abstract

The invention discloses a microwave catalysis and plasma combined waste gas treatment system and method. The system is formed by connecting a pretreatment module, a pretreatment cavity module, a main catalysis cavity module, a tail end purification module and an intelligent control module in series. The pretreatment module adopts two-stage condensation and multi-stage dust removal and is provided with a humidity particle return valve; the pretreatment cavity completes low-temperature oxidation under the cooperation of multi-frequency microwaves and a catalyst; the main catalytic cavity integrates a pulse corona-enhanced plasma discharge structure and a 2.45 / 5.80 GHz double-frequency microwave source, and cooperates with a catalyst to deeply crack VOCs. The tail end module achieves waste heat recovery and fine purification through double heat exchangers and double activated carbon adsorption, and a terminal monitors emission online through Fourier infrared. And the intelligent control module predicts and adjusts the microwave power, the discharge frequency and the valve position in real time based on a long short-term memory (LSTM) network algorithm, namely LSTM, so that the system keeps high-efficiency, low-energy-consumption and stable operation under the conditions of high humidity and multi-component VOCs (Volatile Organic Compounds).

Description

Technical Field

[0001] This invention relates to the field of industrial waste gas treatment technology, specifically to a microwave catalytic combined plasma waste gas treatment system and method, which is suitable for the purification of VOCs waste gas with high humidity and complex composition. Background Technology

[0002] With the acceleration of industrialization, the large amounts of volatile organic compounds (VOCs) generated by industries such as spraying, printing, and chemicals have become one of the major sources of air pollution. These waste gases are typically characterized by high concentrations, high humidity, entrained particulate matter, and complex compositions. Existing treatment methods such as activated carbon adsorption, regenerative thermal oxidation (RTO), or single plasma treatment are insufficient to ensure purification efficiency while simultaneously controlling system energy consumption, and also suffer from problems such as rapid catalyst deactivation and insufficient purification capacity. Summary of the Invention

[0003] To address the shortcomings of existing technologies in terms of processing efficiency, energy consumption, and intelligence, this invention proposes a microwave catalytic combined plasma waste gas treatment system and method. The system consists of a pretreatment module, a pretreatment chamber module, a main catalytic chamber module, an end-of-pipe purification module, and an intelligent control module connected in series, forming a continuous purification channel through pipelines. It is suitable for the synergistic and efficient treatment of complex components and high-humidity VOCs waste gases. The system comprehensively utilizes multi-frequency microwave heating, plasma discharge, and composite catalytic mechanisms, and introduces a Long Short-Term Memory (LSTM) network algorithm for predictive control, achieving deep decomposition and energy consumption optimization of high-bond-energy, recalcitrant pollutants.

[0004] To achieve the above objectives, the present invention provides a microwave catalytic combined plasma waste gas treatment system, comprising: The pretreatment module consists of an intake Fourier transform infrared spectroscopy detection module, an intake parameter integrated sensor assembly, a two-stage condenser (with a first condensation section and a second condensation section inside), a condensate discharge pipe, a multi-stage dust removal assembly, a dust removal outlet integrated sensor assembly, a humidity-particulate matter linkage shut-off valve, a pretreatment circulation return pipe, and a pretreatment exhaust Fourier transform infrared spectroscopy detection module. It is responsible for cooling, dehumidification, and dust removal, and achieves closed-loop retreatment through the return pipe when humidity or particulate matter exceeds the standard.

[0005] The pretreatment chamber module adopts a metal sealed shell and is equipped with a pretreatment catalyst bed, an adjustable circulating fan and a multi-frequency microwave feed device to achieve the first stage of low-temperature microwave catalytic oxidation. The exhaust gas is guided to the main catalytic chamber module or the end purification module respectively through the pretreatment exhaust three-way guide valve according to whether it meets the standard.

[0006] The main catalytic chamber module is equipped with a pulsed corona-enhanced plasma composite discharge structure, a main catalyst bed, and a high-frequency microwave feed device arranged sequentially along the airflow direction. It performs deep cracking and efficient oxidation of residual VOCs through the synergistic effect of plasma-microwave-catalysis. An infrared spectroscopy monitoring device is provided at the exhaust gas outlet to provide real-time feedback on the treatment effect.

[0007] The end-of-pipe purification module is connected to the pretreatment bypass via the first heat exchanger and to the main catalytic converter via the second heat exchanger. Inside, a first heat energy transmission pipeline, a first temperature and humidity detection sensor, a first activated carbon adsorber, a second heat energy transmission pipeline, a second temperature and humidity detection sensor, and a second activated carbon adsorber are installed in sequence to achieve waste heat recovery and fine purification of exhaust gas. A terminal Fourier transform infrared spectroscopy detection module is installed at the exhaust pipe outlet to confirm online emission compliance.

[0008] The intelligent control module consists of a data acquisition unit, an LSTM prediction unit, and an execution controller. It collects information such as temperature, humidity, and VOC concentration in real time, dynamically adjusts microwave power, discharge parameters, and the opening of the pre-treatment exhaust three-way guide valve based on the prediction results, and triggers alarms and emergency operation strategies in abnormal situations to ensure the system operates efficiently, with low energy consumption, and in a stable manner over a long period of time.

[0009] The present invention also provides a waste gas treatment method based on the above system, comprising the following steps: The exhaust gas is cooled to approximately 40°C and 5°C and dehumidified by a two-stage condenser. Subsequently, gravity settling and pulse bag filter dust collection maintain a particle removal rate of ≥99.5%. If humidity or dust levels exceed limits, the gas is returned to the first condenser for recirculation. This step stabilizes and reduces humidity and dust load, providing a clean gas source for subsequent microwave discharge and catalytic reactions. If humidity or particle levels exceed limits, the humidity-particulate matter interlock valve closes, and the gas flow returns to the first condenser for recirculation via a return pipe.

[0010] Qualified exhaust gas enters the pretreatment chamber and undergoes low-temperature oxidation under the synergistic effect of composite microwaves at 433MHz, 866MHz, 2.45GHz, and 5.80GHz and a honeycomb catalyst. The intelligent control module reads FTIR concentration data every 2 seconds as a criterion for subsequent diversion. The intelligent control module reads FTIR and sensor data in real time to obtain the exhaust gas concentration as the basis for subsequent diversion logic judgment.

[0011] When the exhaust gas is below the set threshold for 30 consecutive seconds, the three-way valve switches to the branch, and the airflow is cooled by the first heat exchanger and then directly discharged through the first activated carbon adsorber.

[0012] The non-compliant exhaust gas enters the main catalytic chamber, where pulsed corona-enhanced plasma discharge (3kHz) and 2.45 / 5.80GHz microwave synergistic silicon carbide-rare earth catalyst deeply crack the C~F and C~Cl bonds. The cracked exhaust gas is cooled by the second heat exchanger and purified by the second activated carbon adsorber before being discharged.

[0013] The main exhaust channel is used for emission, and the two exhaust gases converge at the end purification module. After passing through heat exchange and dual-stage activated carbon adsorption purification, the gases are discharged. The terminal Fourier transform infrared spectroscopy detection module confirms online that the emissions meet the standards.

[0014] The LSTM module continuously predicts the load over 2-5 seconds and adjusts microwave power, discharge frequency, and valve position within 1 second; it detects abnormalities, triggers an alarm, and enters emergency mode. The overall system energy consumption is approximately 2.1 kWh / 100m³. 3 / h.

[0015] Through the above steps, the system realizes a synergistic mechanism of front-end steady-state humidity control and dust removal + dual-chamber staged oxidation + waste heat cascade recovery + LSTM predictive control, which greatly improves the purification efficiency of PFCs and complex VOCs and significantly reduces energy consumption. It is suitable for continuous treatment in high-humidity and high-load environments such as electronics and chemical industries.

[0016] Compared with existing technologies, the present invention has the following beneficial effects: This invention employs a dual-cavity, staged, synergistic purification approach, coupling multi-frequency microwaves, enhanced plasma, and a composite catalyst to achieve efficient pre-degradation of low-to-medium concentration VOCs and deep pyrolysis of high-concentration, recalcitrant components. Waste heat is recovered and the intake air is preheated via a first and second heat exchanger, forming an energy cascade utilization system that significantly reduces overall energy consumption. Combined with closed-loop intelligent predictive control driven by the LSTM algorithm, it maintains high removal rates and low energy consumption even under fluctuating operating conditions. The entire system is suitable for long-term industrial operation of complex, high-humidity VOCs waste gas, combining high efficiency, low operating costs, and excellent stability. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a longitudinal cross-sectional schematic diagram of a microwave catalytic combined plasma waste gas treatment system provided by the present invention.

[0019] Figure 2This is a schematic flowchart of the exhaust gas treatment method for the etching section of an integrated circuit factory provided in a specific embodiment of this application.

[0020] 1. Intake Fourier Transform Infrared Spectroscopy Module; 2. Intake Parameter Integrated Sensor Assembly; 3. Two-Stage Condenser; 4. Condensate Drainage Pipe; 5. Multi-Stage Dust Removal Assembly; 6. Dust Removal Outlet Integrated Sensor Assembly; 7. Humidity-Particulate Matter Linkage Shut-off Valve; 8. Pretreatment Circulation Backflow Pipe; 9. Adjustable Circulating Fan; 10. Multi-Frequency Microwave Feeding Device; 11. Pretreatment Catalyst Bed; 12. Pretreatment Chamber Shell; 13. Pretreatment Exhaust Fourier Transform Infrared Spectroscopy Module; 14. Pretreatment Exhaust Three-Way Guide Valve; 15. Pre- 16. Main emission control pipe; 17. First heat exchanger; 18. First heat energy transmission pipeline; 19. First temperature and humidity sensor; 20. First activated carbon adsorber; 21. Main catalytic reaction chamber; 22. Main catalyst bed; 23. Operation control panel; 24. Pulsed corona-enhanced plasma composite discharge structure; 25. High-frequency microwave feed device; 26. Second heat exchanger; 27. Second heat energy transmission pipeline; 28. Terminal Fourier transform infrared spectroscopy detection module; 29. ​​Second temperature and humidity sensor; 20. Second activated carbon adsorber. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1 Schematic diagram of a microwave catalytic combined plasma waste gas treatment system (component numbers are described in the text). This system is designed for treating high-concentration volatile organic compounds (VOCs) and particulate matter exhaust gases generated by the electronics manufacturing industry, and can be expanded to similar operating conditions as needed. Figure 1 As shown, the device consists of an initial detection section, a pretreatment module, a pretreatment chamber, a main catalytic chamber, a terminal purification module, and an intelligent control module connected in series, resulting in a compact structure. The system has a rated processing air volume of 1000 m³ / h. 3 / h, can operate stably for a long time under continuous production conditions.

[0023] The system operation process is as follows: The exhaust gas first enters the Fourier Transform Infrared (FTIR) spectroscopy detection module 1 at the inlet end, where the types of VOCs in the mixed gas are rapidly qualitatively analyzed and their concentrations estimated. The detection results are transmitted to the intelligent control module in real time, providing baseline data reference for subsequent valve opening and microwave power adjustment. After initial monitoring, the exhaust gas passes through two-stage condensers 3, namely the first and second condensation units, achieving staged cooling and dehumidification. The gas temperature drops to approximately 40℃ and 5℃ respectively, and the relative humidity decreases to 40~50%RH, thus condensing out most of the moisture. The condensed water is periodically discharged through corrosion-resistant drainage pipes 4 to prevent water accumulation within the system. The dehumidified and cooled airflow then enters the multi-stage dust removal assembly 5, which includes a gravity settling chamber and a pulse bag filter unit, to collaboratively remove particulate matter from the exhaust gas. This dust removal chain achieves a comprehensive particulate matter removal efficiency of ≥99.5%, providing a clean gas source for subsequent fine processing. If online monitoring detects that the humidity or particulate matter concentration of the exhaust gas after condensation or dust removal still exceeds the set threshold, the humidity-particulate matter linkage shut-off valve 7 will automatically close the main channel and open the pretreatment circulation return pipeline 8 to guide the substandard airflow back to the first-stage condensation unit for reprocessing. Through this closed-loop return pretreatment mechanism, it is ensured that the gas entering the next stage of treatment meets the requirements of dryness and cleanliness.

[0024] After sufficient cooling and dust removal, and with all indicators meeting standards, the exhaust gas enters the pretreatment chamber 12. Inside this chamber, a honeycomb ceramic catalyst bed 11 is installed, and an adjustable-speed circulating fan 9 guides the airflow evenly through the catalyst bed. A multi-frequency microwave feed device 10 couples electromagnetic energy (frequency ranges including 433MHz, 866MHz, 2.45GHz, and 5.80GHz) from the surrounding environment of the chamber, exciting an oxidation reaction on the catalyst surface at a relatively low temperature, decomposing some VOCs components, thus achieving the first stage of exhaust gas purification. Throughout the pretreatment microwave catalysis process, the intelligent control system reads the real-time concentration changes of VOCs in the exhaust gas within the chamber as a basis for determining the airflow direction.

[0025] When monitoring results indicate that the VOCs concentration in the exhaust gas at the pretreatment chamber outlet has decreased to within the acceptable range, the pretreatment exhaust three-way diverter valve 14 switches to the bypass branch position. At this time, the airflow is diverted to the pretreatment branch for treatment. First, the gas is cooled to a lower temperature by the first heat exchanger 16. Then, the waste heat is removed through the first heat energy transfer pipe 17, and the temperature and humidity are monitored and confirmed by the first temperature and humidity sensor 18 to meet the emission requirements. Finally, it enters the first activated carbon adsorber 19 for deep adsorption purification. After the above treatment, the clean and compliant exhaust gas is directly discharged into the atmosphere from the exhaust port of the pretreatment branch.

[0026] If the pretreatment chamber exhaust gas monitoring still shows non-compliance (VOCs concentration exceeding emission limits), the three-way valve 14 maintains the main channel direction, and the gas flow continues to enter the main catalytic chamber 20 for further treatment. Inside the main catalytic chamber, the gas is first broken down by a pulsed corona-enhanced plasma composite discharge structure 23, generating highly active plasma. The gas flow then passes through the main catalyst bed 21 and simultaneously receives high-frequency microwave energy input 24. Under the strong coupling effect of a discharge frequency of 1.5~2.5kHz and a microwave power of approximately 4200W, recalcitrant high-bond-energy compounds in the exhaust gas (such as C~F, C~Cl halogenated hydrocarbon bonds, and polycyclic aromatic hydrocarbons) are effectively broken down. After plasma-microwave synergistic deep oxidation treatment, the harmful components in the exhaust gas are completely decomposed.

[0027] After deep treatment in the main catalytic converter chamber, the exhaust gas is cooled down by the second heat exchanger 25, and some of the waste heat is recovered through the second heat transfer pipe 26. Before emission, the airflow is monitored by the second temperature and humidity sensor 28 to ensure that its temperature and humidity meet standards. It then enters the second activated carbon adsorber 29 for final adsorption and purification, removing residual trace VOCs and byproducts. The purified exhaust gas is then discharged from the exhaust port of the main catalytic converter branch, meeting emission standards.

[0028] This system integrates an intelligent control panel 22, which contains a data acquisition unit and a prediction model based on a Long Short-Term Memory (LSTM) network. The control system receives real-time data from multiple sources, including FTIR sensors, temperature and humidity sensors, VOCs concentration detection, and differential pressure, and can predict load changes within the next 2-5 seconds. Based on these predictions, the control system dynamically adjusts key parameters such as microwave power, plasma discharge frequency, and valve opening every second. When abnormal operating conditions are detected, the system automatically switches to emergency mode to ensure safe and continuous processing.

[0029] Under normal operating conditions, the microwave power of the pretreatment chamber is approximately 2800W, the microwave power of the main catalytic chamber is approximately 4200W, the total capacity of the built-in catalyst is approximately 45L, and the operating temperature of the main reaction zone is maintained at approximately 510~520℃. The system is designed with periodic condensate drainage (approximately every 20 minutes) to prevent condensate buildup from affecting operating efficiency.

[0030] During a continuous 120-hour operation test, the device consistently maintained VOCs emission concentrations in the exhaust gas at ≤15ppm, demonstrating excellent purification efficiency. The overall energy consumption is approximately 2.1 kWh / 100m³. 3 The exhaust gas exhibits low energy consumption and good economic efficiency. No malfunctions such as catalyst sintering deactivation, condensation unit blockage, or abnormal discharge were observed during operation, indicating that the system maintains good operational stability and safety even under high humidity and high particulate load conditions.

[0031] The above results demonstrate that this microwave catalytic-plasma combined waste gas treatment system exhibits advantages such as high removal efficiency, low energy consumption, and high reliability in the treatment of industrial waste gas with high humidity and high pollution load. This device can meet the stringent requirements for long-term continuous emission control in industries such as electronics and chemicals, providing an efficient and safe solution for the deep purification of industrial organic waste gas and particulate matter.

[0032] Example 2 This embodiment employs the microwave catalytic combined plasma waste gas treatment system described in Embodiment 1 to continuously treat the complex exhaust gas (initial VOC concentration approximately 240 ppm, relative humidity 85% RH, containing submicron particulate matter) emitted from the etching section of an integrated circuit plant. The treatment process is attached. Figure 2 As shown, steps S1 to S5 are completed sequentially.

[0033] Step S1: Pre-treatment, cooling and dust removal.

[0034] The exhaust gas undergoes parallel operation through two-stage condensers, with a coolant temperature of 3°C. The gas temperature is cooled in two stages from 40°C to 5°C, and the relative humidity is stabilized at 40~50%RH. The condensate is discharged through a drain pipe. After treatment by the combination of gravity settling chamber and pulse bag filter, the particle removal rate remains ≥99.5%. If the humidity or particulate matter concentration exceeds the limit, the humidity-particulate matter linkage shut-off valve closes the main channel, and the airflow returns to the first condensation section for recirculation through the return pipe. The inlet FTIR and parameter sensors synchronously output concentration, humidity, and dust data.

[0035] Step S2: Low-temperature microwave catalytic oxidation and real-time monitoring.

[0036] The pretreated exhaust gas enters the pretreatment chamber and undergoes low-temperature oxidation with the honeycomb ceramic catalyst bed under the synergistic effect of low-frequency microwave preheating (433MHz, 866MHz) and high-frequency microwave surface excitation (2.45GHz, 5.80GHz), pre-removing approximately 50% of low-to-medium concentration VOCs. The intelligent control module reads FTIR data at 2-second intervals, which is used as a diversion criterion.

[0037] Step S3: Discharge from compliant branch lines.

[0038] When the VOCs concentration at the pretreatment chamber outlet remains below the set threshold for 30 consecutive seconds, the three-way diverter valve switches to the branch circuit. The airflow recovers waste heat and cools down via the first heat exchanger, then enters the first activated carbon adsorber for deep purification before being discharged. Under this branch circuit operating condition, the cooling energy consumption is reduced by approximately 15% compared to the main channel.

[0039] Step S4: Deep pyrolysis and emission of substandard main channels.

[0040] If the concentration does not meet the standard, the three-way valve maintains the main channel flow direction, and the gas flow enters the main catalytic chamber, passing through pulsed corona-enhanced plasma discharge (3kHz) and 2.45GHz / 5.80GHz dual-frequency microwave (power density 95WL). -1 A synergistic silicon carbide-rare earth catalyst bed is used to deeply cleave high-bond-energy chemical bonds such as C~F and C~Cl at 510~520℃. The cleavage tail gas is cooled by a second heat exchanger, then finely purified by a second activated carbon adsorber before being discharged. The two branches are independent of each other, and the end of each branch is confirmed to meet standards online by FTIR.

[0041] Step S5: Intelligent closed-loop control and operating condition switching.

[0042] The system is preset with three operating conditions: "standard," "high humidity," and "drainage." The LSTM prediction model performs rolling load forecasts for the next 5 minutes. When humidity exceeds the limit for 5 consecutive minutes, the system automatically switches to high humidity mode, lowers the coolant temperature, and closes the reflux valve. If abnormal pressure or temperature differences are detected, the control system issues an alarm and performs bag filter cleaning or coolant flow adjustment. During 120 hours of operation, the outlet VOC concentration was ≤15ppm, the system pressure drop was 1180±40Pa, and no condensation blockage, catalyst deactivation, or abnormal discharge occurred, indicating the long-term stability of the method under high humidity and high load conditions. The comprehensive energy consumption was measured at 2.1 kW·h / 100m³. 3 Exhaust gas.

[0043] The microwave-plasma dual-cavity system in this embodiment relies on a "two-stage condensation + bag filter" pretreatment to achieve steady-state humidity regulation and dust removal of high-humidity, high-dust exhaust gases, ensuring long-term reliability of subsequent microwave and plasma discharge processes. The multi-frequency microwave and pulsed discharge in the main catalytic chamber work in synergy to rapidly decompose recalcitrant VOCs such as halogenated hydrocarbons at 510~520℃; the reaction zone exhibits uniform temperature and minimal pressure drop fluctuations, with no condensation blockage or overheating runaway occurring throughout the process. The end-stage heat exchange-dual-stage activated carbon adsorption pathway further reduces energy consumption and ensures long-term compliance of the exhaust gas. The LSTM predictive control module, combined with real-time concentration and humidity data, continuously adjusts power and valve positions, maintaining high removal rates and low energy consumption even under fluctuating loads, verifying the device's adaptability and operational safety in medium-to-high load scenarios such as integrated circuit etching.

[0044] Example 3 This embodiment addresses the emission of fluorinated organic waste gas from the high-load etching process in an integrated circuit factory. It employs the microwave catalytic combined with plasma waste gas treatment system described in Example 1. Without adding any additional modules, an in-situ regeneration strategy ensures long-term catalyst use and stable system operation. The exhaust gas components include perfluorinated compounds such as CF4 (50 ppm) and C2F6 (2 ppm), with a total VOCs concentration of approximately 100 ppm, including benzene, toluene, and chloroethane. The relative humidity is maintained at 55%–65%. The system has a continuous operating time of 1000 hours and a processing air volume of 1000 m³ / h. 3 / h.

[0045] Throughout the entire operating cycle, the process flow is consistent with Example 2, including seven stages: secondary condensation and dehumidification, multi-stage dust removal, first-stage low-temperature oxidation in the pretreatment chamber, three-way diversion and flow distribution, deep pyrolysis in the main catalytic chamber, heat exchange-adsorption end purification, and intelligent closed-loop control. To maintain catalyst activity and system load response capability, the following regeneration and monitoring strategies are implemented during operation: 1. Catalyst online regeneration strategy Every 200 hours of operation, while maintaining a chamber temperature of 510~520℃ in the main catalytic chamber, plasma discharge is paused while a 2.45GHz microwave input is retained. The system automatically switches the gas supply, introducing a 3vol% O2 / N2 mixed gas for surface rinsing for 30 minutes to achieve carbon deposit desorption and reactivation of active components. During this period, the exhaust gas is switched to a pretreatment branch for separate discharge.

[0046] 2. Real-time monitoring and control mechanism The intelligent control module collects data such as exhaust gas concentration, temperature difference, and pressure difference every 2 seconds using FTIR and multi-point temperature and humidity sensors; it also uses an LSTM prediction model to model the load fluctuation trend in real time for the next 2-5 minutes. When the predicted VOCs concentration exceeds the set threshold or a local pressure difference anomaly occurs, the system completes the synchronous adjustment of microwave power, discharge frequency, and valve position within 1 second, and triggers alarm and emergency response procedures if necessary.

[0047] 3. Evaluation of catalytic performance and system stability During a 1000-hour continuous operation cycle, the average removal rate of CF4 was 71.2%, the removal rate of C2F6 was 64.3%, and the removal rate of non-fluorinated VOCs remained above 91.7%; the system pressure drop fluctuation range was 1180±50 Pa. After each online regeneration, BET specific surface area testing and XRD crystal structure detection confirmed that the catalyst structure remained stable, with a surface area decay rate of less than 5%, and no obvious sintering or deloading phenomena were observed. The microwave reflection power fluctuation was within ±3%, and the discharge current showed no drift.

[0048] 4. Energy consumption trends and economic performance The overall specific energy consumption is approximately 2.1 kWh / 100m² during the start-up phase. 3 After running for 600 hours, the power consumption of the fuel system steadily decreased to 2.0 kW·h / 100m³. 3 This indicates that the synergistic effect of waste heat recovery efficiency and power regulation algorithm enhances the economic efficiency of system operation.

[0049] This embodiment demonstrates that, without replacing key modules and catalytic materials, by constructing a periodic online regeneration and dynamic closed-loop control mechanism, the system operating cycle can be effectively extended, the high-fluorine component cracking efficiency can be improved, microwave load energy consumption can be reduced, and the process resistance to fluctuations can be enhanced. It is suitable for continuous processing scenarios with medium air volume in the electronics industry, and has application prospects, especially in production lines where frequent replacement of consumables is not possible or where long-cycle operation requirements are high.

[0050] Table 1 Comparison of Device Performance As shown in Table 1, the device of this invention, by utilizing dual-cavity segmented purification, multi-frequency microwave-plasma synergy, and LSTM predictive control, achieves a CF4 removal rate increase of approximately 18 percentage points, a comprehensive energy consumption reduction of approximately 25%, and a system voltage drop decrease of approximately 15% compared to a single-cavity single-frequency microwave device. Furthermore, the device's dynamic response time is <2s, enabling rapid peak suppression of high fluoride concentration fluctuations, thus verifying the technical advantages of the synergy between multi-frequency microwave and intelligent predictive control.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A microwave catalytic combined with plasma waste gas treatment system, characterized in that, include: The pretreatment module is used to cool, dehumidify, and perform multi-stage dust removal on exhaust gas containing VOCs and dust. The pretreatment module is equipped with an exhaust gas inlet, a condensate discharge pipe, and a pretreatment outlet. Two condensers are connected in series inside the module, which contains a first condensation section and a second condensation section. Subsequently, there are multi-stage dust removal components, a dust removal outlet integrated sensor component, and a humidity-particulate matter linkage shut-off valve. The return end of the linkage shut-off valve is connected to the inlet of the first condensation section through a pretreatment circulation return pipe. The pretreatment chamber module has an air inlet, an exhaust gas outlet and a bypass outlet. The interior includes a pretreatment catalyst bed, an adjustable circulating fan and a multi-frequency microwave feed device. The air inlet is connected to the pretreatment outlet, and the exhaust gas outlet and the bypass outlet are respectively connected to the main channel and the branch channel of the pretreatment exhaust three-way guide valve. The main catalytic chamber module has a catalytic inlet and a main catalytic exhaust outlet. Inside the main catalytic chamber module, along the exhaust flow direction, a pulsed corona-enhanced plasma composite discharge structure, a main catalyst bed, and a high-frequency microwave feed device containing two microwave sources, 2.45GHz±0.05GHz and 5.80GHz±0.05GHz, are arranged sequentially. The power of the two microwave sources can be independently modulated, with a power ratio range of 1:1-3:1, and they are located in the same reaction zone as the plasma discharge structure to achieve multi-frequency microwave-plasma synergistic cracking and catalytic oxidation. The catalytic inlet is connected to the main channel of the pre-treated exhaust three-way guide valve, and the main catalytic exhaust outlet is connected to the terminal purification module via a second heat exchanger. The terminal purification module has one inlet connected to a branch of the pre-treated exhaust three-way guide valve via a first heat exchanger, and another inlet connected to the main catalytic exhaust outlet via a second heat exchanger. Inside the terminal purification module, a first heat energy conveying pipe, a first temperature and humidity detection sensor, a first activated carbon adsorber, a second heat energy conveying pipe, a second temperature and humidity detection sensor, and a second activated carbon adsorber are sequentially arranged. The treated exhaust gas is incorporated into the system exhaust pipe, and a terminal Fourier transform infrared spectroscopy detection module is installed at the exhaust pipe outlet. The intelligent control module includes a data acquisition unit, a predictive analysis unit, and an execution controller. The predictive unit adopts a long short-term memory neural network, and the LSTM prediction time window of the intelligent control module is 2-5s. When the predicted value is higher than the threshold Xppm or the humidity is higher than the threshold Y%RH, the controller's execution delay for the predicted over-limit signal does not exceed 1s, synchronously adjusts the microwave power ≥Z%, adjusts the discharge frequency ≤0.5kHz, and switches the flow direction of the three-way guide valve.

2. The system according to claim 1, characterized in that, The first and second condensing sections inside the secondary condenser sequentially perform multi-stage condensation and cooling of the exhaust gas; the dust removal outlet integrates a sensor component to monitor humidity and particulate matter concentration in real time. When the monitored value exceeds the standard, the humidity-particulate matter linkage shut-off valve is triggered to close, and the exhaust gas is returned to the first condensing section for reprocessing through the pretreatment circulation return pipeline.

3. The system according to claim 1, characterized in that, The pretreatment catalyst bed of the pretreatment chamber module has a honeycomb ceramic structure, and the adjustable circulating fan has an acceleration mode and a residence time extension mode. When the exhaust gas meets the emission standards, the pretreatment exhaust three-way guide valve switches to the branch channel, allowing the exhaust gas to bypass the main catalytic chamber module and directly enter the terminal purification module. When the exhaust gas does not meet the standards, the valve switches to the main channel, guiding the exhaust gas into the main catalytic chamber module for further treatment.

4. The system according to claim 1, characterized in that, The main catalytic chamber module is internally arranged along the airflow direction, consisting of a pulsed corona-enhanced plasma composite discharge structure, a main catalyst bed, and a high-frequency microwave feed device. The pulsed corona-enhanced plasma composite discharge structure is used for pre-cracking of macromolecular organic matter and generating high-energy active particles to enhance the oxidation reaction. The high-frequency microwave feed device provides synergistic heating and plasma maintenance for the main catalyst bed to improve the decomposition efficiency of residual VOCs. An infrared spectral monitoring device is installed at the exhaust gas outlet of the main catalytic chamber module and is electrically connected to the intelligent control module. This device is used to collect the spectral characteristics and concentration information of the exhaust gas after deep decomposition in real time and send adjustment commands to the intelligent control module when the detection results exceed a set threshold.

5. The system according to claim 1, characterized in that, The terminal purification module recovers waste heat from the pretreated exhaust gas through a first heat exchanger and waste heat from the main catalytic converter exhaust gas through a second heat exchanger. The exhaust gas after heat exchange passes through a first activated carbon adsorber and a second activated carbon adsorber for deep adsorption and purification before being discharged into the system exhaust pipe. The terminal Fourier transform infrared spectroscopy detection module is used to confirm online that emissions meet standards and to feed the detection results back to the intelligent control module.

6. The system according to claim 1, characterized in that, The predictive analysis unit of the intelligent control module is based on the Long Short-Term Memory (LSTM) network algorithm to predict historical and real-time data of temperature, humidity and VOCs concentration. The execution controller automatically adjusts the microwave power, discharge parameters and the opening and closing of the pre-treatment exhaust three-way guide valve according to the prediction results, and triggers an alarm and adjusts the operating conditions when an abnormality or exceeding the standard is detected.

7. A microwave catalytic combined plasma waste gas treatment method, using the system according to any one of claims 1 to 6 for waste gas treatment, characterized in that, Includes the following steps: The exhaust gas is introduced into the pretreatment module, where it is cooled, dehumidified, and subjected to multi-stage dust removal in sequence. The pretreated exhaust gas is introduced into the pretreatment chamber, where it undergoes the first stage of oxidation under the synergistic effect of multi-frequency microwaves and catalysts, and the exhaust gas concentration is monitored in real time by the intelligent control module. When the monitoring results show that the exhaust gas meets the standards, the three-way diverter valve is switched to the branch, and the gas is discharged after being cooled by the first heat exchanger and purified by the first activated carbon adsorber in sequence. When the monitoring results show that the exhaust gas does not meet the standards, the three-way guide valve is switched to the main channel, the gas enters the main catalytic chamber, and is deeply cracked under the synergistic effect of plasma discharge and high-frequency microwave. After being cooled by the second heat exchanger and purified by the second activated carbon adsorber, it is discharged. Throughout the entire execution process of all the above steps, the intelligent control module continuously collects temperature, humidity and VOCs concentration data, predicts pollutant fluctuations in real time within 2-5 seconds based on LSTM, and adjusts microwave power, discharge frequency and valve status within 1 second; when abnormalities or exceeding standards are detected, alarms and emergency adjustments are triggered to ensure long-term system stability and low-energy emission compliance.

8. Throughout the entire treatment process, the intelligent control module continuously collects airflow temperature, relative humidity, and VOCs concentration, and uses the LSTM algorithm to predict pollutant fluctuations within the next 2-5 seconds. Within 1 second of generating the prediction results, it completes closed-loop adjustments to microwave power, plasma discharge frequency, and valve opening. When any monitored parameter exceeds the limit or malfunctions, the system immediately issues an alarm and switches to emergency mode to maintain long-term stable operation of the device and ensure continuous compliance with emission standards under low energy consumption conditions.

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