NO based on plasma-activated water x Processing system and method

Abstract

This invention provides a NO based on plasma-activated water. x This invention relates to the field of industrial waste gas treatment technology, specifically to a treatment system and method for removing nitrogen oxides (NOx). x The exhaust gas; using plasma-activated water containing oxidants, spraying NO... x The exhaust gas, to absorb NO x In plasma-activated water, oxidant and NO x A redox reaction occurs, and the reaction products include water-soluble nitrate ions. This invention utilizes plasma-activated water containing an oxidant, sprayed with NO... x The exhaust gas effectively removes NO. x Meanwhile, the activation reaction module of this invention can be integrated into the industrial waste gas treatment module, realizing NO... x The removal of [the pollutant] results in zero increase in land use costs. This invention integrates a plasma-activated water device into a semiconductor plasma exhaust gas treatment system, achieving the denitrification goals of zero reagent addition, zero wastewater discharge, and zero increase in land use costs while efficiently treating semiconductor exhaust gas.

Description

Technical Field

[0001] This invention relates to the field of industrial waste gas treatment technology, and more particularly to a method for treating NO based on plasma-activated water. x Processing systems and methods. Background Technology

[0002] Plasma equipment is widely used in the treatment of semiconductor fluoride waste gases. For example, carbon tetrafluoride (CF4) and sulfur hexafluoride (SF6) in semiconductor waste gases are difficult to remove using combustion or other methods; plasma technology can be used to treat these hazardous waste gases. However, these semiconductor waste gases also contain components such as nitrogen (N2) and oxygen (O2). In the high-temperature environment of plasma (typically >1300℃), N2 and O2 react to easily generate nitrogen oxides (NOx). x (N2 + O2 → NO) x This leads to secondary pollution.

[0003] Traditional NO x Control requires the addition of alkaline reagents (e.g., alkaline scrubbing towers) or catalysts, but semiconductor factories do not have the conditions for additional storage or transportation of alkaline reagents in their exhaust gas treatment spaces. Furthermore, plasma equipment used for exhaust gas treatment generally includes a high-temperature plasma reaction chamber and a high-humidity spray chamber, making it difficult to use catalysts for extended periods in plasma equipment.

[0004] In summary, existing semiconductor waste gas treatment processes generate nitrogen oxides (NOx) as a secondary pollutant. x Difficult to remove. Summary of the Invention

[0005] This invention provides a NO based on plasma-activated water. x Treatment systems and methods are provided to address the issue of nitrogen oxides (NOx) generated as secondary pollution during the treatment of semiconductor waste gas in existing technologies. x Overcoming the difficulty in removing defects, this method aims to remove nitrogen oxides (NOx) generated as secondary pollutants during the semiconductor waste gas removal process. x .

[0006] This invention provides a NO based on plasma-activated water. x The treatment system includes: an industrial waste gas treatment module, an activation reaction module, and a power determination module.

[0007] The industrial waste gas treatment module is used to treat industrial waste gas and remove nitrogen oxides (NOx). x exhaust gas;

[0008] The activation reaction module uses plasma-activated water containing oxidant, and sprays it with NO. x The exhaust gas, to absorb NO x In plasma-activated water, oxidant and NO xA redox reaction occurs, and the reaction products include nitrate ions that are soluble in water;

[0009] The power determination module is used to determine the power based on the dissociation power of the mixed gas, the dissociation power of the working gas, and the spray power of the plasma-activated water, as variables, the gas flow rate of the mixed gas, the flow rate of the plasma-activated water, and NO. x Based on the concentration, construct the objective function;

[0010] The power determination module is also used to ensure NO x When the processing rate is greater than or equal to the set processing efficiency, the objective function is solved to obtain the determined values ​​of the dissociation power of the mixed gas, the dissociation power of the working gas, and the spraying power of the plasma-activated water. The set processing efficiency characterizes the effect on NO. x Minimum requirements for processing.

[0011] NO based on plasma-activated water provided by the present invention x The processing system also includes NO x The processing rate determination module and the industrial waste gas treatment module include NO. x The detection unit and activation reaction module include an oxidant generation unit;

[0012] NO x The detection unit is used to detect NO. x NO in exhaust gas x The concentration;

[0013] The oxidant generation unit is used to determine the concentration of the oxidant in the plasma-activated water;

[0014] NO x The processing rate determination module is used to obtain NO. x The concentration of NO and the concentration of oxidant, based on NO x The concentration of NO and the concentration of oxidant are used to determine NO. x Processing rate.

[0015] NO based on plasma-activated water provided by the present invention x The treatment system, specifically the industrial waste gas treatment module, also includes a plasma reaction chamber.

[0016] The plasma reaction chamber is used to ionize a mixture of industrial waste gas, nitrogen, and oxygen, causing the waste gas, nitrogen, and oxygen to react and produce NO. x The exhaust gas.

[0017] NO based on plasma-activated water provided by the present invention x Processing system, NO x The detection unit includes an airflow detector, a temperature detector, and a calculator;

[0018] An airflow detector is used to detect the airflow of a gas mixture;

[0019] Temperature detectors are used to measure the reaction temperature inside the plasma reaction chamber;

[0020] The calculator is used to calculate the residence time of the mixed gas in the plasma reaction chamber based on the flow rate of the mixed gas and the volume of the plasma reaction chamber.

[0021] The calculator is also used to determine the reaction rate constant based on the reaction temperature;

[0022] The calculator is also used to calculate NO based on the gas flow rate, reaction temperature, residence time, and reaction rate constant of the gas mixture. x The concentration.

[0023] NO based on plasma-activated water provided by the present invention x The processing system, including the oxidant generation unit, comprises a working gas detection unit;

[0024] The working gas detection unit is used to detect the flow of working gas for plasma-activated water;

[0025] The oxidant generating unit is used to dissociate the working gas, contact the dissociated working gas with water, and generate oxidant to produce plasma-activated water;

[0026] The oxidant generation unit is also used to determine the concentration of the oxidant based on the gas flow rate and the dissociation power of the working gas.

[0027] NO based on plasma-activated water provided by the present invention x In the treatment system, the concentration of the oxidant is determined based on the following method:

[0028] A mapping relationship is constructed between the recorded working gas flow rate, the recorded working gas dissociation power, and the recorded oxidant concentration to obtain an oxidant concentration library.

[0029] Based on the gas flow rate and dissociation power of the working gas, the concentration of the oxidant is matched from the concentration library of oxidants.

[0030] NO based on plasma-activated water provided by the present invention x The processing system also includes a loop module:

[0031] The circulation module is used to cool down the plasma-activated water output from the activation reaction module and input the cooled plasma-activated water back into the activation reaction module.

[0032] The activation reaction module uses cooled plasma-activated water to wash the exhaust gas generated after the oxidation-reduction reaction, so as to recycle the plasma-activated water.

[0033] NO based on plasma-activated water provided by the present invention x The treatment system also includes an exhaust gas detection module:

[0034] The exhaust gas detection module is used to detect the temperature and NO of the exhaust gas. x The residual amount, when temperature and NO x When the residual amount meets the discharge conditions, the exhaust gas is discharged.

[0035] This invention also provides a NO based on plasma-activated water. x The treatment method is applied to the above-mentioned NO treatment based on plasma-activated water. x The processing system includes:

[0036] Obtain NO containing nitrogen oxides x exhaust gas;

[0037] Using plasma-activated water containing oxidants, spraying water containing NO x The exhaust gas, to absorb NO x In plasma-activated water, oxidant and NO x A redox reaction occurs, and the reaction products include nitrate ions that are soluble in water;

[0038] Using the dissociation power of the mixed gas, the dissociation power of the working gas, and the spray power of the plasma-activated water as variables, based on these variables, the gas flow rate of the mixed gas, the flow rate of the plasma-activated water, and NO... x Based on the concentration, construct the objective function;

[0039] While ensuring NO x When the processing rate is greater than or equal to the set processing efficiency, the objective function is solved to obtain the determined values ​​of the dissociation power of the mixed gas, the dissociation power of the working gas, and the spraying power of the plasma-activated water. The set processing efficiency characterizes the effect of NO... x Minimum requirements for processing.

[0040] The present invention provides a NOx treatment system and method based on plasma-activated water, which obtains NOx containing nitrogen oxides. x The exhaust gas; using plasma-activated water containing oxidants, spraying NO... x The exhaust gas, to absorb NO x In plasma-activated water, oxidant and NO x A redox reaction occurs, and the reaction products include water-soluble nitrate ions. This invention utilizes plasma-activated water containing an oxidant, sprayed with NO... x The exhaust gas effectively removes NO. xMeanwhile, the activation reaction module of this invention can be integrated into the industrial waste gas treatment module, realizing NO... x The removal of nitrification results in zero increase in land use costs. Based on the characteristic that plasma jet power sources can activate water to generate strong oxidants, this invention integrates a plasma-activated water device into a semiconductor plasma waste gas treatment system. This achieves the denitrification goal of zero reagent addition, zero wastewater discharge, and zero increase in land use costs while efficiently treating semiconductor waste gas. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 This invention provides NO based on plasma-activated water. x A schematic diagram of the processing system.

[0043] Figure 2 This invention provides NO based on plasma-activated water. x One of the flowcharts for the processing method.

[0044] Figure 3 This invention provides NO based on plasma-activated water. x The second flowchart of the processing method.

[0045] Figure 4 This invention provides NO based on plasma-activated water. x The third flowchart of the processing method.

[0046] Figure label:

[0047] 101: Nitrogen input pipeline; 102: Industrial waste gas input pipeline; 103: Air input pipeline; 104: Nitrogen flow controller; 105: Industrial waste gas flow monitor; 106: Air flow controller; 107: Plasma torch; 108: Plasma reaction chamber; 109: Water tank; 110: Power supply for oxidant generation unit; 111: Plasma activated water spray gun; 112: Underwater plasma; 113: Nozzle; 114: Waste gas flow path; 115: Plate heat exchanger; 116: Exhaust gas temperature detector; 117: Exhaust gas discharge pipeline; 118: Hazardous substance detector. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0049] The following is combined Figures 1-4 The present invention describes NO based on plasma-activated water. x Processing systems and methods.

[0050] like Figure 1 As shown, this invention provides a NO based on plasma-activated water. x The treatment system includes: an industrial waste gas treatment module and an activation reaction module.

[0051] The industrial waste gas treatment module is used to treat industrial waste gas and remove nitrogen oxides (NOx). x exhaust gas;

[0052] The activation reaction module uses plasma-activated water containing oxidant, and sprays it with NO. x The exhaust gas, to absorb NO x In plasma-activated water, oxidant and NO x A redox reaction occurs, and the reaction products include nitrate ions that are soluble in water.

[0053] The present invention relates to NO based on plasma-activated water x The treatment system can be applied to the treatment of various industrial waste gases. This invention uses the treatment of industrial waste gases from semiconductor processes as an example for illustration.

[0054] Industrial waste gas is treated to obtain nitrogen oxides (NOx). x The waste gas. For example, industrial waste gas from semiconductor processes undergoes preliminary treatment processes such as washing, dust removal, or oxidation-reduction reactions. During these preliminary treatments, secondary pollution is generated, producing nitrogen oxides (NOx). x Exhaust gas. NO x It is an environmental pollutant, NO x It irritates the eyes and upper respiratory tract, and can cause throat discomfort and dry cough; high concentrations or long-term exposure can cause delayed pulmonary edema, adult respiratory distress syndrome, and may induce pneumothorax / mediastinal emphysema. x As a significant air pollutant, it also poses a considerable threat to the environment. x NO can react chemically with water, oxygen, and other chemicals in the atmosphere, forming secondary pollutants such as acid rain and photochemical smog, which damage ecosystems. Therefore, NO... xSuch handling is absolutely necessary.

[0055] This invention uses an activation reaction module to treat nitrogen oxides (NO). x The exhaust gas. The activation reaction module includes several nozzles 113. The nozzles spray plasma-activated water containing an oxidant to absorb NO. x NO in exhaust gas x NO x This includes NO, NO2, etc. The activation reaction module is equipped with an oxidant generation unit to generate oxidants and produce plasma-activated water.

[0056] Oxidizing agents include strong oxidizing agents such as hydroxyl radicals (·OH), ozone (O3), and hydrogen peroxide (H2O2). Alternatively, oxidizing agents include nitric oxide radicals (·NO), nitrogen dioxide (NO2), and nitric acid (HNO3). Taking strong oxidizing agents such as ·OH, O3, and H2O2 as examples, the oxidizing agent and NO... x The following redox reaction occurs.

[0057] NO + ·OH → HNO2;

[0058] NO2+·OH→HNO3;

[0059] 4NO + 4O3 + 2H2O → 4HNO3 + 3O2;

[0060] 2NO2 + O3 → N2O5 + O2 → 2HNO3;

[0061] After a redox reaction, water-soluble nitrate ions are generated, such as -NO2 and -NO3. This is achieved through the reaction of an oxidizing agent and NO... x The oxidation-reduction reaction between them removes NO from the exhaust gas. x .

[0062] The NO based on plasma-activated water provided in this embodiment of the invention x The treatment system includes: an industrial waste gas treatment module and an activation reaction module. The industrial waste gas treatment module is used to treat industrial waste gas and remove nitrogen oxides (NOx). x The exhaust gas; the activation reaction module uses plasma activation water containing oxidant, sprayed with NO... x The exhaust gas, to absorb NO x In plasma-activated water, oxidant and NO x A redox reaction occurs, and the reaction products include water-soluble nitrate ions. This invention utilizes plasma-activated water containing an oxidant, sprayed with NO... x The exhaust gas effectively removes NO. x Meanwhile, the activation reaction module of this invention can be integrated into the industrial waste gas treatment module, realizing NO... xThe removal of nitrification results in zero increase in land use costs. Based on the characteristic that plasma jet power sources can activate water to generate strong oxidants, this invention integrates a plasma-activated water device into a semiconductor plasma waste gas treatment system. This achieves the denitrification goal of zero reagent addition, zero wastewater discharge, and zero increase in land use costs while efficiently treating semiconductor waste gas.

[0063] Based on the above embodiments, the industrial waste gas treatment module further includes a plasma reaction chamber 108:

[0064] The plasma reaction chamber is used to ionize a mixture of industrial waste gas, nitrogen, and oxygen, causing the waste gas, nitrogen, and oxygen to react and produce NO. x The exhaust gas.

[0065] The industrial waste gas treatment module includes a plasma device. This device uses high-energy electrons and free radicals to react with pollutants in the industrial waste gas from semiconductor processes, converting them into harmless substances. Industrial waste gas contains harmful substances such as fluorides and silicides. Fluorides include carbon tetrafluoride (CF4) and sulfur hexafluoride (SF6).

[0066] Industrial waste gas, nitrogen (N2), and oxygen (O2) enter the plasma reaction chamber of the plasma equipment from the top, forming a mixed gas. Nitrogen serves as the working medium gas for the plasma torch, forming the plasma flame. Simultaneously, some of the industrial waste gas requires oxygen for complete treatment. Inside the plasma reaction chamber, the industrial waste gas is dissociated through high-energy electron collisions within the plasma region, while N2 and O2 react to produce NO. x .

[0067] This invention effectively removes harmful substances from industrial waste gases that are difficult to remove through combustion or other methods by ionizing the mixed gas.

[0068] Based on the above embodiments, NO based on plasma-activated water x The processing system also includes NO x The processing rate determination module and the industrial waste gas treatment module include NO. x The detection unit and activation reaction module include an oxidant generation unit;

[0069] NO x The detection unit is used to detect NO. x NO in exhaust gas x The concentration;

[0070] The oxidant generation unit is used to determine the concentration of the oxidant in the plasma-activated water;

[0071] NO x The processing rate determination module is used to obtain NO. xThe concentration of NO and the concentration of oxidant, based on NO x The concentration of NO and the concentration of oxidant are used to determine NO. x Processing rate.

[0072] NO x The concentration of NO in the plasma reaction chamber x The concentration of NO. x The concentration of NO represents the reaction between industrial waste gas, nitrogen, and oxygen to produce NO. x The rate. NO x The higher the concentration of NO, the faster the reaction rate between industrial waste gas, nitrogen, and oxygen, resulting in the production of NO. x The faster the speed.

[0073] NO x The detection unit is used to detect NO. x NO in exhaust gas x The concentration of NO. x The detection unit monitors NO by tracking the reaction progress of industrial waste gas, nitrogen, and oxygen within the plasma reaction chamber. x The generation rate of NO was derived from this. x The concentration.

[0074] The oxidant generation unit dissociates the working gas and then contacts the dissociated working gas with water to obtain ion-activated water containing a strong oxidant. The concentration of the oxidant characterizes the rate at which the working gas dissociates to generate the oxidant. The higher the oxidant concentration, the faster the rate at which the working gas dissociates to generate the oxidant.

[0075] Optionally, the working gas of the oxidant generating unit includes nitrogen (N2) or oxygen (O2), preferably O2. The oxidant generating unit includes a plasma-activated water spray gun. The working gas (e.g., O2) is sprayed out through the plasma-activated water spray gun and dissociated at the head of the spray gun while the spray gun is immersed in water. Strong oxidants such as ·OH, O3, and H2O2 are continuously generated near the head of the underwater plasma-activated water spray gun, forming plasma-activated water. The oxidant generating unit derives the concentration of oxidant in the plasma-activated water by monitoring the dissociation rate of O2.

[0076] NO x The processing rate determination module is used to obtain NO. x The concentration of NO and the concentration of oxidant, based on NO x The concentration of NO and the concentration of oxidant are used to determine NO. x Processing speed. NO x The processing rate determination module uses the effective rate constant and NO... x Calculate NO based on the concentration of NO and the concentration of oxidant. x Processing speed. NOx The formula for calculating the processing rate is as follows.

[0077] ;

[0078] in, NO x Processing speed The effective rate constant is determined by temperature, pressure, and the presence of NO. x The degree of mixing between the exhaust gas and plasma-activated water is affected by various factors. NO x The concentration.

[0079] Optionally, multiple previously recorded NO values ​​can be recorded experimentally. x The concentration of the oxidant, the concentration of the recorded oxidant, and the recorded NO x Processing rate. Construct the recorded NO. x The concentration of the oxidant, the concentration of the recorded oxidant, and the recorded NO x The mapping relationship between the three factors of processing speed yields NO. x Processing rate library. According to NO. x The concentration of the oxidant and the concentration of the oxidant can be found in the NO list. x Processing speed library, can quickly obtain NO x Processing rate.

[0080] NO x The processing rate needs to be greater than or equal to the set processing rate (minimum NO). x Processing rate), to meet NO x The minimum treatment requirements. Furthermore, this can be achieved by monitoring NO levels in plasma-activated water. x NO in exhaust gas from the treatment system x The residual amount of NO was determined. x Does the treatment rate meet the standard? If NO in the exhaust gas... x The residual amount exceeds the set target value, indicating that NO x The processing rate is too low; NO needs to be increased. x Processing rate. If NO in the exhaust gas x The residual amount is less than the set target value, indicating that NO x The processing rate has been met. Optionally, the minimum NO can be determined based on the set target value. x Processing rate.

[0081] Furthermore, such as Figure 3 As shown, according to NO x Treatment rate, optimize spray parameters to control NO xThe absorption efficiency. Spray parameters include the spray power of the plasma-activated water. The spray power of the plasma-activated water determines the circulation rate of the plasma-activated water. The spray power of the plasma-activated water includes the power of the water pump. For example, when the calculated NO... x When the processing rate is high, the power of the water pump needs to be increased to improve the circulation rate of the plasma-activated water. When the calculated NO... x When the processing rate is low, the power of the water pump can be appropriately reduced to reduce system energy consumption.

[0082] This invention uses NO x Calculate NO based on the concentration of NO and the concentration of oxidant. x Processing speed, enabling NO x Effective monitoring of processing rate. This is achieved by monitoring NO... x The concentration of NO and the concentration of oxidant can be used to calculate NO. x Processing speed, which will abstract and be difficult to monitor NO x Processing speed was converted into easily detectable NO. x The concentration of the oxidant and the concentration of the oxidant.

[0083] Based on the above embodiments, NO x The detection unit includes an airflow detector, a temperature detector, and a calculator;

[0084] An airflow detector is used to detect the airflow of a gas mixture;

[0085] Temperature detectors are used to measure the reaction temperature inside the plasma reaction chamber;

[0086] The calculator is used to calculate the residence time of the mixed gas in the plasma reaction chamber based on the flow rate of the mixed gas and the volume of the plasma reaction chamber.

[0087] The calculator is also used to determine the reaction rate constant based on the reaction temperature;

[0088] The calculator is also used to calculate NO based on the gas flow of the mixed gas, the reaction temperature, the residence time, and the reaction rate constant. x The concentration.

[0089] The gas flow rate of the mixed gas includes the flow velocity of the mixed gas flowing into the plasma device. The reaction temperature includes the temperature at which the industrial waste gas, nitrogen, and oxygen react within the plasma reaction chamber.

[0090] like Figure 1As shown, the top of the plasma equipment is equipped with a nitrogen input pipe 101 (for inputting nitrogen), an industrial waste gas input pipe 102 (for inputting industrial waste gas), and an air input pipe 103 (for inputting air to provide oxygen). The airflow detector includes a nitrogen flow controller 104, an industrial waste gas flow monitor 105, and an air flow controller 106. The nitrogen input pipe is equipped with a nitrogen flow controller to detect the nitrogen flow. The industrial waste gas input pipe is equipped with an industrial waste gas flow monitor to monitor the industrial waste gas flow. The air input pipe is equipped with an air flow controller to detect the air flow. The airflow detector sends the detected nitrogen, industrial waste gas, and air flow to a calculator.

[0091] A temperature detector is installed inside the plasma reaction chamber to detect the reaction temperature when industrial waste gas, nitrogen, and oxygen react. The temperature detector sends the detected reaction temperature to a calculator.

[0092] The calculator obtains the gas flow rate of the mixed gas by analyzing the flow rates of nitrogen, industrial waste gas, and air. Based on the flow rate of the mixed gas and the volume of the plasma reaction chamber, the calculator calculates the residence time of the mixed gas within the plasma reaction chamber. Optionally, the residence time of the mixed gas in the high-temperature zone of the plasma reaction chamber can be determined based on the ratio of the flow rate of the mixed gas to the volume of the plasma reaction chamber. Furthermore, to ensure safety, the pressure of the mixed gas within the plasma reaction chamber should be within a safe range, for example, 40-500 kPa.

[0093] The calculator determines the reaction rate constant based on the reaction temperature; it also calculates NO based on the gas flow rate, reaction temperature, residence time, and reaction rate constant of the mixed gas. x The concentration of NO. x The formula for calculating the concentration is as follows.

[0094] ;

[0095] in, NO x concentration, For the duration of stay, The reaction temperature, Let be the reaction rate constant, which is a constant that varies with reaction temperature. The concentration of nitrogen gas can be obtained by measuring the flow of nitrogen gas. The concentration of oxygen can be obtained through airflow. For activation energy, This is the universal gas constant.

[0096] Furthermore, such as Figure 3 As shown, by predicting NO xThe concentration guides the oxidant generation unit to prepare in advance, producing enough oxidant (ensuring a sufficiently high oxidant concentration), thereby achieving feedforward preparation of the oxidant.

[0097] This invention calculates NO by considering the gas flow rate, reaction temperature, residence time, and reaction rate constant of the mixed gas. x The concentration of NO will be difficult to monitor. x The concentration of NO was monitored by easily monitored gas flow, reaction temperature, residence time, and reaction rate constant, thus reducing NO levels. x The cost and efficiency of concentration monitoring.

[0098] Based on the above embodiments, the oxidant generating unit includes a working gas detection unit;

[0099] The working gas detection unit is used to detect the flow of working gas for plasma-activated water;

[0100] The oxidant generating unit is used to dissociate the working gas, contact the dissociated working gas with water, and generate oxidant to produce plasma-activated water;

[0101] The oxidant generation unit is also used to determine the concentration of the oxidant based on the gas flow rate and the dissociation power of the working gas.

[0102] The oxidant generation unit includes a plasma-activated water spray gun 111. Before being input into the plasma-activated water spray gun, the flow rate of the working gas is detected by a gas flow meter (working gas detection unit). The working gas (e.g., O2) is ejected through the plasma-activated water spray gun. A power supply 110 of the oxidant generation unit supplies power to the plasma-activated water spray gun, causing the working gas to dissociate at the head of the spray gun while it is submerged in water. Strong oxidants such as ·OH, O3, and H2O2 are continuously generated near the head of the underwater plasma-activated water spray gun, producing underwater plasma 112 and forming plasma-activated water. The oxidant generation unit derives the concentration of the oxidant in the plasma-activated water by monitoring the dissociation rate of the working gas (e.g., O2).

[0103] Optionally, the power supply for the oxidant generating unit includes a jet power supply. The head of the plasma-activated water spray gun is fixed inside the water tank and connected to the jet power supply via a waterproof sealed interface. The power of the jet power supply ranges from 1 to 2 kW. The discharge frequency of the jet power supply ranges from 20 to 60 kHz.

[0104] The dissociation rate of the working gas is determined by the gas flow rate and the dissociation power of the working gas. For example... Figure 3As shown, the gas flow rate and dissociation power of the working gas determine the effective electron energy range during the dissociation process. The effective electron energy range determines the effectiveness of the working gas in generating an oxidant, i.e., the efficiency of working gas dissociation. A higher efficiency of working gas dissociation indicates a higher percentage of dissociated working gas used for oxidant generation. A lower efficiency of working gas dissociation indicates a lower percentage of dissociated working gas used for oxidant generation. The effective electron energy range determines the efficiency of the oxidant generation unit. The oxidant generation unit determines the oxidant concentration based on the working gas flow rate and dissociation power.

[0105] Furthermore, a higher concentration of oxidant indicates a higher efficiency in oxidant generation by the oxidant-generating unit. Conversely, a lower concentration of oxidant indicates a lower concentration of oxidant produced.

[0106] This invention determines the concentration of the oxidant by measuring the gas flow rate and dissociation power of the working gas, thus simplifying the method for monitoring the concentration of the oxidant.

[0107] Based on the above embodiments, the concentration of the oxidant was determined in the following manner:

[0108] A mapping relationship is constructed between the recorded working gas flow rate, the recorded working gas dissociation power, and the recorded oxidant concentration to obtain an oxidant concentration library.

[0109] Based on the gas flow rate and dissociation power of the working gas, the concentration of the oxidant is matched from the concentration library of oxidants.

[0110] Multiple experiments were conducted to determine the concentration of the oxidant produced by the oxidant generating unit. Based on the experimental results, the recorded gas flow rate, the recorded dissociation power of the working gas, and the recorded concentration of the oxidant were obtained.

[0111] A mapping relationship is constructed between the recorded working gas flow rate, the recorded working gas dissociation power, and the recorded oxidant concentration to obtain an oxidant concentration library. For example, a one-to-one mapping relationship is constructed between the recorded working gas flow rate, the recorded working gas dissociation power, and the recorded oxidant concentration to obtain an oxidant concentration library.

[0112] Actual NO x During the processing, the concentration of the oxidant is determined by matching the detected gas flow rate and dissociation power of the working gas with the concentration library of the oxidant.

[0113] This invention improves the efficiency of obtaining oxidant concentration by matching a concentration library of oxidants to obtain the final oxidant concentration.

[0114] Based on the above embodiments, NO based on plasma-activated water x The processing system also includes a power determination module;

[0115] The power determination module is used to determine the power based on the dissociation power of the mixed gas, the dissociation power of the working gas, and the spray power of the plasma-activated water, as variables, the gas flow rate of the mixed gas, the flow rate of the plasma-activated water, and NO. x Based on the concentration, construct the objective function;

[0116] The power determination module is also used to ensure NO x When the processing rate is greater than or equal to the set processing efficiency, the objective function is solved to obtain the determined values ​​of the dissociation power of the mixed gas, the dissociation power of the working gas, and the spraying power of the plasma-activated water.

[0117] In order to reduce NO in plasma-activated water x To address the energy consumption of the processing system, this invention designs a dynamic energy allocation optimization algorithm. For example... Figure 3 As shown, the dynamic energy allocation optimization algorithm monitors or calculates the gas flow rate of the mixed gas, the flow rate of plasma-activated water, and NO. x The concentration of NO was determined, and the dissociation power of the mixed gas, the dissociation power of the working gas, and the spraying power of the plasma-activated water were calculated to ensure the NO concentration based on the plasma-activated water. x The system employs a minimum energy consumption operation strategy to optimize system energy consumption.

[0118] The spray power of the plasma-activated water is determined by the power of the water pump. The power determination module uses the dissociation power of the mixed gas, the dissociation power of the working gas, and the spray power of the plasma-activated water as variables, based on the variables, the gas flow rate of the mixed gas, the flow rate of the plasma-activated water, and NO. x The concentration is used to construct the objective function. The formula for calculating the objective function is as follows.

[0119] ;

[0120] in, , and These are the weighting coefficients. The dissociation power of the gas mixture. The spray power of plasma-activated water. The dissociation power of the working gas. NO x concentration, The gas flow is a mixture of gases. This refers to the flow rate of the plasma-activated water.

[0121] While ensuring NOx When the processing rate is greater than or equal to the set processing efficiency, solve the objective function to obtain the determined values ​​of the dissociation power of the mixed gas, the dissociation power of the working gas, and the spraying power of the plasma-activated water. The constraints of the objective function are as follows.

[0122] ;

[0123] in, NO x Processing speed To set the processing efficiency, the processing efficiency characterizes the system's response to NO. x Minimum requirements for processing.

[0124] Solve for the objective function, i.e., solve for NO based on plasma-activated water. x The processing system (system) meets the requirements for NO. x Given the minimum requirements for treatment, determine the minimum energy consumption operating strategy for the system. This is based on NO removal from plasma-activated water. x The energy consumption of the treatment system is determined by the dissociation power of the mixed gas, the dissociation power of the working gas, and the spray power of the plasma-activated water.

[0125] Furthermore, at regular intervals, based on the objective function and its constraints, the dissociation power of the mixed gas, the dissociation power of the working gas, and the spraying power of the plasma-activated water are adjusted to achieve the desired NO emission reduction effect based on plasma-activated water. x Timed optimization of the energy consumption of the processing system.

[0126] This invention ensures NO x When the processing rate is greater than or equal to the set processing efficiency, the objective function is solved to obtain the determined values ​​of the dissociation power of the mixed gas, the dissociation power of the working gas, and the spraying power of the plasma-activated water. This ensures that the system meets the requirements for NO. x Under the minimum requirements of treatment, the lowest energy consumption operation strategy of the system was solved, and the NO based on plasma-activated water was realized. x Minimize the energy consumption of the processing system.

[0127] Based on the above embodiments, NO based on plasma-activated water x The processing system also includes a loop module:

[0128] The circulation module is used to cool down the plasma-activated water output from the activation reaction module and input the cooled plasma-activated water back into the activation reaction module.

[0129] The activation reaction module uses cooled plasma-activated water to wash the exhaust gas generated after the oxidation-reduction reaction, so as to recycle the plasma-activated water.

[0130] like Figure 1 As shown, the circulation module includes a water tank 109 and a plate heat exchanger. The water tank receives the plasma-activated water (i.e., spray water) that has undergone a redox reaction, output from the activation reaction module. The water tank then feeds the sprayed plasma-activated water into the plate heat exchanger. The plate heat exchanger cools the sprayed plasma-activated water and then feeds the cooled plasma-activated water back into the activation reaction module.

[0131] The activation reaction module uses cooled plasma-activated water to wash the exhaust gas generated after the oxidation-reduction reaction, so as to recycle the plasma-activated water.

[0132] The plasma-activated water after spraying is cooled and then reused, which can be used to wash the exhaust gas and further remove residual NO from it. x This invention also cools the exhaust gas, preventing it from becoming too hot during emission. By incorporating a circulation module, the invention enables the recycling of plasma-activated water, thereby increasing its utilization rate.

[0133] Based on the above embodiments, NO based on plasma-activated water x The treatment system also includes an exhaust gas detection module:

[0134] The exhaust gas detection module is used to detect the temperature and NO of the exhaust gas. x The residual amount, when temperature and NO x When the residual amount meets the discharge conditions, the exhaust gas is discharged.

[0135] The exhaust gas detection module includes an exhaust gas temperature detector and a hazardous substance detector. For example... Figure 1 As shown, an exhaust gas temperature detector 116 and a hazardous substance detector 118 are installed at the exhaust gas discharge pipe 117. The exhaust gas temperature detector is used to detect the temperature of the exhaust gas. The hazardous substance detector can detect NO. x The residual amount.

[0136] When the temperature of the exhaust gas is lower than the set temperature for exhaust gas emission, and NO... x When the residual amount is less than the set residual amount of exhaust gas, it is determined that the exhaust gas can be discharged.

[0137] Furthermore, when the exhaust gas temperature detected by the exhaust gas detection module is higher than the set exhaust gas emission temperature, the temperature of the plasma activated water after spraying can be reduced by adjusting the plate heat exchanger 115. During the exhaust gas washing process, the exhaust gas temperature is further reduced until it is lower than the set exhaust gas emission temperature.

[0138] Furthermore, based on the detected NO in the exhaust gas... xThe residual amount of NO is controlled by adjusting the gas flow rate of the mixed gas, the reaction temperature in the plasma reaction chamber, the gas flow rate of the working gas, and the dissociation power of the working gas. x The concentration of NO and the concentration of oxidant, thereby increasing NO x Processing rate.

[0139] like Figure 2 As shown, in NO based on plasma-activated water x In the treatment system, a mixture of industrial waste gas, nitrogen (N2), and oxygen (O2) enters the plasma reaction chamber from the top of the plasma equipment. Inside the plasma reaction chamber, the plasma torch 107 dissociates the gas mixture, forming a plasma flame and generating high temperatures within the chamber. Within this high-temperature chamber, the industrial waste gas is dissociated through high-energy electron collisions in the ion regions (high-temperature treatment), while N2 and O2 react to generate NO. x .

[0140] Several nozzles are installed in the lower space of the plasma reaction chamber. These nozzles spray plasma-activated water, which is effective against high-temperature NO-containing water. x The exhaust gas is sprayed to reduce humidity and absorb NO. x A redox reaction occurs. The plasma-activated water, after spraying, falls into the water tank. Based on the NO content of the plasma-activated water... x The exhaust gas flow path in the treatment system is as follows: After the oxidation-reduction reaction, the exhaust gas enters the scrubbing tower. Several nozzles are also installed inside the scrubbing tower. The plasma-activated water from the water tank, after being sprayed, is cooled by a plate heat exchanger and then returned to the nozzles in the scrubbing tower to further cool and scrub the exhaust gas. The scrubbed plasma-activated water is then received back into the water tank and recycled. After further cooling and scrubbing by spraying, the exhaust gas meets emission requirements and is discharged from the equipment's tailpipe outlet.

[0141] This invention utilizes high-temperature gas-phase plasma (containing NO) x By combining the waste gas (from semiconductor manufacturing processes) with plasma-activated water containing oxidants, the problem of NO byproducts in industrial waste gas treatment has been overcome. x The problem of removal.

[0142] This invention increases the concentration of ·OH by using plasma interface discharge with working gases such as oxygen or nitrogen, thus overcoming the bottleneck of low efficiency in traditional spray denitrification.

[0143] This invention only requires the addition of working gases such as oxygen or nitrogen, without the need for additional chemical reagents or the generation of chemical sludge.

[0144] The activation reaction module of this invention can be integrated into an industrial waste gas treatment module, achieving NO... xThe removal of nitrification results in zero increase in land use cost. Based on the characteristic that plasma jet power sources can activate water to generate strong oxidants (e.g., ·OH, O3), this invention integrates a plasma-activated water device into a semiconductor plasma exhaust gas treatment system, achieving the denitrification goal of zero reagent addition, zero wastewater discharge, and zero increase in land use cost while efficiently treating semiconductor exhaust gas.

[0145] This invention enables automatic monitoring of oxidant concentration and NO concentration. x concentration of NO x Processing rate. This invention achieves this by automatically optimizing the dissociation power of the mixed gas, the dissociation power of the working gas, and the spraying power of the plasma-activated water, while ensuring NO... x While maintaining high processing speed, the system energy consumption is reduced. This invention can achieve NO x Remote monitoring of the process reduces labor costs.

[0146] like Figure 4 As shown, embodiments of the present invention also provide a NO based on plasma-activated water. x The treatment method is applied to the above-mentioned NO treatment based on plasma-activated water. x The processing system includes steps S100-S200, each step of which is detailed below:

[0147] S100: Obtain NO containing nitrogen oxides x exhaust gas;

[0148] S200: Uses plasma-activated water containing oxidants, sprayed with NO. x The exhaust gas, to absorb NO x In plasma-activated water, oxidant and NO x A redox reaction occurs, and the reaction products include nitrate ions that are soluble in water;

[0149] S300: Using the dissociation power of the mixed gas, the dissociation power of the working gas, and the spray power of the plasma-activated water as variables, based on the variables, the airflow of the mixed gas, the flow rate of the plasma-activated water, and NO... x Based on the concentration, construct the objective function;

[0150] S400: While ensuring NO x When the processing rate is greater than or equal to the set processing efficiency, the objective function is solved to obtain the determined values ​​of the dissociation power of the mixed gas, the dissociation power of the working gas, and the spraying power of the plasma-activated water. The set processing efficiency characterizes the effect on NO. x Minimum requirements for processing.

[0151] The present invention provides NO based on plasma-activated water x The specific steps involved in the process are as follows.

[0152] Step 1: System Start-up. Open the plasma reaction chamber; industrial waste gas enters the plasma reaction chamber from the top cover and is decomposed. Start the plate heat exchanger and control the water tank temperature at 25±5℃.

[0153] Step 2: Plasma-activated water generation. Oxygen is introduced into the plasma-activated water spray gun (e.g., flow rate 3 L / min), and an 8 kV voltage is applied to generate a plasma jet underwater in the tank. After continuous discharge for 30 minutes, the H2O2 concentration in the water reaches 50 mg / L, and the oxidation-reduction potential (ORP) > 800 mV.

[0154] Step 3: Spray denitrification. Plasma-activated water is pumped to the spray tower via a high-pressure water pump, with a liquid-to-gas ratio of 1.5 L / m³. 3 Contains NO x The exhaust gas comes into countercurrent contact with plasma-activated water inside the spray tower (residence time ≥ 2s).

[0155] Step 4: Water Quality Management. Regularly replenish the water tank with 20% fresh water and discharge nitrate-containing wastewater to the neutralization tank. Monitor the pH of the water tank in real time, maintaining the pH of the plasma-activated water at 6.5-7.5 and the conductivity of the plasma-activated water ≤200μS / cm.

[0156] The NO based on plasma-activated water provided in this embodiment of the invention x The treatment method involves obtaining nitrogen oxides (NO) x The exhaust gas; using plasma-activated water containing oxidants, spraying NO... x The exhaust gas, to absorb NO x In plasma-activated water, oxidant and NO x A redox reaction occurs, and the reaction products include water-soluble nitrate ions. This invention utilizes plasma-activated water containing an oxidant, sprayed with NO... x The exhaust gas effectively removes NO. x Meanwhile, the activation reaction module of this invention can be integrated into the industrial waste gas treatment module, realizing NO... x The removal of nitrification results in zero increase in land use costs. Based on the characteristic that plasma jet power sources can activate water to generate strong oxidants, this invention integrates a plasma-activated water device into a semiconductor plasma waste gas treatment system. This achieves the denitrification goal of zero reagent addition, zero wastewater discharge, and zero increase in land use costs while efficiently treating semiconductor waste gas.

[0157] The plasma-activated water of this invention also has a water purification function. The plasma-activated water generated in the water tank is rich in active substances (such as hydroxyl radicals, hydrogen peroxide, ozone, etc.) and is also a major bactericidal component. It can kill microorganisms by destroying cell walls and cell membranes, thus purifying the water. The NO based on plasma-activated water of this invention... x Compared to traditional alkaline washing and reduction methods, this treatment method eliminates the risks of reagent leakage and explosion.

[0158] The system / device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0159] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A NOx treatment system based on plasma-activated water x A processing system characterized by, The application comprises: industrial waste gas treatment module, activation reaction module, NO x treatment rate determination module and power determination module; the industrial waste gas treatment module comprises NO x detection unit and plasma reaction cavity, and the activation reaction module comprises an oxidant generation unit: The plasma reaction cavity is used for ionizing mixed gas containing industrial waste gas, nitrogen and oxygen, making the industrial waste gas, the nitrogen and the oxygen react, and obtaining waste gas containing nitrogen oxide NO x ​ The activation reaction module sprays the exhaust gas containing NO x with plasma-activated water containing an oxidizing agent to absorb the NO x x In the plasma-activated water, the oxidizing agent and the NO x undergoes a redox reaction, and the reaction product includes nitrate ions dissolved in water; The NO x detection unit is used to detect the concentration of NO x in the exhaust gas containing NO x ​ The oxidant generating unit is configured to determine the concentration of the oxidant in the plasma-activated water; The NO x processing rate determination module is configured to obtain the concentration of the NO x and the concentration of the oxidizing agent, determine the NO x processing rate based on the concentration of the NO x and the concentration of the oxidizing agent. The oxidant generating unit is configured to dissociate the working gas, contact the dissociated working gas with water, and generate the oxidant to produce the plasma-activated water; The power determination module is used for taking the dissociation power of the mixed gas, the dissociation power of the working gas and the spraying power of the plasma-activated water as variables, and constructing a target function based on the variables, the gas flow of the mixed gas, the flow of the plasma-activated water and the concentration of NO x ​ The power determination module is further configured to ensure that the NO x In a case where the processing rate is greater than or equal to a set processing efficiency, the target function is solved to obtain a determined value of the dissociation power of the mixed gas, a determined value of the dissociation power of the working gas, and a determined value of the spraying power of the plasma activated water, the set processing efficiency representing a minimum requirement for processing NO x x.

2. The NO based on plasma-activated water as described in claim 1 x The processing system is characterized in that, The NO x The detection unit includes an airflow detector, a temperature detector, and a calculator. The airflow detector is configured to detect the airflow of the mixed gas; The temperature detector is configured to measure the reaction temperature in the plasma reaction chamber; The calculator is configured to calculate the residence time of the mixed gas in the plasma reaction chamber based on the flow rate of the mixed gas and the volume of the plasma reaction chamber; The calculator is further configured to determine the reaction rate constant based on the reaction temperature; The calculator is also used to calculate the NO based on the gas flow of the mixed gas, the reaction temperature, the residence time, and the reaction rate constant. x The concentration.

3. The NO based on plasma-activated water as described in claim 1 x The processing system is characterized in that, The oxidant generating unit comprises a working gas detection unit; The working gas detection unit is configured to detect the airflow of the working gas of the plasma-activated water; The oxidant generating unit is further configured to determine the concentration of the oxidant based on the airflow of the working gas and the dissociation power of the working gas.

4. The NO based on plasma-activated water as described in claim 3 x The processing system is characterized in that, The concentration of the oxidant is determined based on the following method: A mapping relationship among the recorded airflow of the working gas, the recorded dissociation power of the working gas, and the recorded concentration of the oxidant is constructed to obtain a concentration library of the oxidant; The concentration of the oxidant is matched in the concentration library of the oxidant based on the airflow of the working gas and the dissociation power of the working gas.

5. The plasma activated water based NOx reduction system of claim 1. x A processing system, characterized by The application further comprises a circulation module: The circulation module is configured to cool the plasma-activated water output by the activation reaction module and input the cooled plasma-activated water into the activation reaction module; The activation reaction module uses the cooled plasma-activated water to wash the tail gas generated after the redox reaction, so as to recycle the plasma-activated water.

6. The NO based on plasma-activated water as described in claim 5 x The processing system is characterized in that, The application further comprises a tail gas detection module: The tail gas detection module is configured to detect a temperature and a residual amount of NOx of the tail gas x when the temperature and the residual amount of NOx satisfy an exhaust condition. x The tail gas detection module is configured to detect a temperature and a residual amount of NOx of the tail gas 7. A NOx based on plasma-activated water x A method of treatment, characterized in that, Plasma-activated water-based NO for use in any one of claims 1 to 6 x A processing system comprising: The mixed gas containing industrial waste gas, nitrogen and oxygen is ionized to make the industrial waste gas, the nitrogen and the oxygen react to obtain waste gas containing nitrogen oxide NO x ​ Spraying a waste gas containing NO x with plasma-activated water containing an oxidizing agent to absorb the NO x ; in the plasma-activated water, the oxidizing agent and the NO x undergo a redox reaction, and the reaction product includes nitrate ions dissolved in water; the plasma-activated water is obtained by dissociating a working gas, contacting the dissociated working gas with water, and generating the oxidizing agent; detecting the concentration of NOx in the exhaust gas containing NOx x detecting the concentration of NOx in the exhaust gas containing NOx x ​ The concentration of the oxidant in the plasma-activated water is determined; Based on the NO x The concentration of NO and the concentration of the oxidant determine NO x Processing speed; With the dissociation power of the mixed gas, the dissociation power of the working gas and the spraying power of the plasma-activated water as variables, a target function is constructed based on the variables, the gas flow of the mixed gas, the flow of the plasma-activated water and the concentration of NO x ​ In the case where the processing rate is greater than or equal to the set processing efficiency, the target function is solved to obtain a determined value of the dissociation power of the mixed gas, a determined value of the dissociation power of the working gas, and a determined value of the spraying power of the plasma-activated water, the set processing efficiency representing the minimum requirement for processing NOx. x x In the case where the processing rate is greater than or equal to the set processing efficiency, the target function is solved to obtain a determined value of the dissociation power of the mixed gas, a determined value of the dissociation power of the working gas, and a determined value of the spraying power of the plasma-activated water, the set processing efficiency representing the minimum requirement for processing NOx.​

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