Semiconductor Industry Waste Gas Treatment Methods and Systems

Abstract

This application relates to the field of waste gas treatment technology, providing a method and system for treating waste gas from the semiconductor industry. The method includes: controlling a deoxygenation reaction unit to deoxygenate the semiconductor industrial waste gas; controlling a gas concentration detection unit to detect the oxygen concentration in the deoxygenated waste gas; controlling a plasma reactor to perform plasma treatment on the deoxygenated waste gas when the oxygen concentration is less than a first concentration threshold; predicting the remaining service life of the deoxidizer in the deoxygenation reaction unit, and replacing or regenerating the deoxidizer when the remaining service life is less than a service life threshold. This application utilizes pre-deoxygenation to suppress nitrogen oxide generation at the source, and uses the prediction of the remaining service life of the deoxidizer to replace or regenerate it in a timely manner. It is sustainable, does not affect the operation of high-precision semiconductor equipment or product yield, and does not require consideration of the efficiency of catalytic decomposition of nitrogen oxides or the energy consumption of high-thermal decomposition.

Description

Technical Field

[0001] This application relates to the field of waste gas treatment technology, specifically to a method and system for treating waste gas in the semiconductor industry. Background Technology

[0002] In the process of treating waste gas in the semiconductor industry, because the waste gas contains toxic, corrosive or flammable and explosive gases, it is necessary to pump a large amount of nitrogen into the waste gas delivery pipeline. The inert properties of nitrogen are used to safely and efficiently transport the waste gas to the treatment equipment for treatment. This results in the main component of the waste gas that actually enters the treatment equipment being nitrogen, along with a small amount of oxygen and other toxic and harmful industrial gases.

[0003] When oxygen and nitrogen are present in the exhaust gas, even if the oxygen content is low, the high temperature of the exhaust gas will still promote the reaction between oxygen and nitrogen, thereby generating excessive nitrogen oxides. If emitted into the outside world, it will cause serious pollution.

[0004] Existing methods for treating waste gas in the semiconductor industry include catalytic reduction of nitrogen oxides, which requires the continuous addition of ammonia as a reducing agent. On the one hand, most semiconductor plants do not have the facilities to continuously supply ammonia. On the other hand, the addition of ammonia may introduce new problems such as ammonia escape, affecting the operation of high-precision semiconductor equipment and product yield. Other methods use catalytic decomposition or high-temperature thermal decomposition of nitrogen oxides, which either have low catalytic efficiency or extremely high energy consumption.

[0005] In summary, some existing methods for treating waste gas in the semiconductor industry are unsustainable and affect the operation of high-precision semiconductor equipment and product yield when dealing with nitrogen oxides; some have low catalytic efficiency; and others have extremely high energy consumption. Summary of the Invention

[0006] This application provides a semiconductor industry waste gas treatment method and system to solve the technical problems of existing semiconductor industry waste gas treatment methods when treating nitrogen oxides, such as some being unsustainable and affecting the operation of high-precision semiconductor equipment and product yield, some having low catalytic efficiency, and others having extremely high energy consumption.

[0007] In a first aspect, embodiments of this application provide a method for treating waste gas from the semiconductor industry, comprising:

[0008] The deoxygenation reaction unit is controlled to deoxygenate the waste gas from the semiconductor industry, resulting in deoxygenated waste gas.

[0009] The control gas concentration detection unit detects the deoxygenated waste gas to obtain the oxygen concentration;

[0010] When the oxygen concentration is less than the first concentration threshold, the plasma reactor is controlled to perform plasma treatment on the deoxygenated waste gas to obtain the treated waste gas.

[0011] The remaining service life of the deoxidizer in the deoxidation reaction unit is predicted. If the remaining service life is less than the service life threshold, the deoxidizer is replaced or regenerated, and the process returns to controlling the deoxidation reaction unit to deoxidize the semiconductor industrial waste gas to obtain deoxidized waste gas, until the treated waste gas is obtained again.

[0012] In one embodiment, predicting the remaining service life of the deoxidizer in the deoxidation reaction unit includes:

[0013] The oxygen capacity of the deoxidizing agent in the deoxidation reaction unit, the real-time flow rate of the deoxidation waste gas, and the real-time oxygen concentration of the deoxidation waste gas are obtained.

[0014] The real-time oxygen content of the deoxygenated waste gas is obtained by multiplying the real-time flow rate and the real-time oxygen concentration.

[0015] The cumulative deoxygenation amount of the deoxygenated waste gas is obtained by integrating the reduction in the real-time oxygen content.

[0016] Based on the difference between the oxygen loading capacity and the cumulative deoxygenation amount, the theoretical residual oxygen capacity of the deoxidizer is obtained;

[0017] The remaining service life of the deoxidizer is predicted based on the difference between the theoretical remaining oxygen capacity and the actual remaining oxygen capacity.

[0018] In one embodiment, predicting the remaining service life of the deoxidizer based on the difference between the theoretical and actual remaining oxygen capacity includes:

[0019] Obtain the reaction bed temperature of the deoxygenation reaction unit;

[0020] If the difference between the theoretical residual oxygen capacity and the actual residual oxygen capacity is greater than the difference threshold, the theoretical residual oxygen capacity is corrected based on the decay relationship between the reaction bed temperature and the residual oxygen capacity of the deoxidizer to obtain the corrected residual oxygen capacity.

[0021] Based on the corrected remaining oxygen capacity, the remaining service life of the deoxidizer is predicted.

[0022] In one embodiment, the controlled plasma reactor performs plasma treatment on the deoxygenated waste gas, including:

[0023] When the oxygen concentration is less than the second concentration threshold and the pollutant concentration in the deoxygenated waste gas is less than the third concentration threshold, the plasma reactor is controlled to reduce the energy input in order to perform plasma treatment on the deoxygenated waste gas.

[0024] The second concentration threshold is less than the first concentration threshold.

[0025] In one embodiment, the controlled plasma reactor performs plasma treatment on the deoxygenated waste gas, including:

[0026] When the oxygen concentration is greater than or equal to a second concentration threshold, or when the pollutant concentration in the deoxygenated waste gas is greater than or equal to a third concentration threshold, the plasma reactor is controlled to increase the energy input to perform plasma treatment on the deoxygenated waste gas.

[0027] In one embodiment, after obtaining the treated waste gas, the process includes:

[0028] The spray device is controlled to spray and wash the treated waste gas to obtain residual exhaust gas.

[0029] The exhaust gas detection unit controls the remaining exhaust gas to detect the nitrogen oxide concentration;

[0030] If the nitrogen oxide concentration exceeds the standard, an alarm system will be triggered;

[0031] If the nitrogen oxide concentration does not exceed the standard, the remaining exhaust gas will be emitted.

[0032] In one embodiment, after the controlled spraying device sprays and washes the treated exhaust gas, it includes:

[0033] The plate heat exchanger is controlled to exchange heat and cool down the residual liquid after spray washing, so as to obtain the cooled liquid.

[0034] The plate heat exchanger is controlled to deliver the cooled liquid as a spraying liquid to the spraying device.

[0035] Secondly, embodiments of this application provide a semiconductor industry waste gas treatment system, including: an intelligent control unit, a deoxygenation reaction unit, a gas concentration detection unit, and a plasma reactor;

[0036] The intelligent control unit is used for:

[0037] The deoxygenation reaction unit is controlled to deoxygenate the semiconductor industry waste gas to obtain deoxygenated waste gas.

[0038] The gas concentration detection unit is controlled to detect the deoxygenated waste gas and obtain the oxygen concentration;

[0039] When the oxygen concentration is less than a first concentration threshold, the plasma reactor is controlled to perform plasma treatment on the deoxygenated waste gas to obtain treated waste gas;

[0040] The remaining service life of the deoxidizer in the deoxidation reaction unit is predicted. If the remaining service life is less than the service life threshold, the deoxidizer is replaced or regenerated, and the process returns to controlling the deoxidation reaction unit to deoxidize the semiconductor industrial waste gas to obtain deoxidized waste gas, until the treated waste gas is obtained again.

[0041] In one embodiment, it further includes: a spraying device and an exhaust gas detection unit;

[0042] The intelligent control unit is also used for:

[0043] The spraying device is controlled to spray and wash the treated waste gas to obtain residual exhaust gas.

[0044] The exhaust gas detection unit is controlled to detect the remaining exhaust gas and obtain the nitrogen oxide concentration;

[0045] If the nitrogen oxide concentration exceeds the standard, an alarm system will be triggered;

[0046] If the nitrogen oxide concentration does not exceed the standard, the remaining exhaust gas will be emitted.

[0047] In one embodiment, it further includes: a plate heat exchanger;

[0048] The intelligent control unit is also used for:

[0049] The plate heat exchanger is controlled to exchange heat and cool down the residual liquid after spray washing, so as to obtain the cooled liquid.

[0050] The plate heat exchanger is controlled to deliver the cooled liquid as a spraying liquid to the spraying device.

[0051] The semiconductor industry waste gas treatment method provided in this application involves controlling a deoxygenation reaction unit to deoxygenate the semiconductor industry waste gas, obtaining deoxygenated waste gas, controlling a gas concentration detection unit to detect the oxygen concentration of the deoxygenated waste gas, and controlling a plasma reactor to perform plasma treatment on the deoxygenated waste gas when the oxygen concentration is less than a first concentration threshold, obtaining treated waste gas, predicting the remaining service life of the deoxidizer in the deoxygenation reaction unit, and replacing or regenerating the deoxidizer when the remaining service life is less than the service life threshold, returning to the step of controlling the deoxygenation reaction unit to deoxygenate the semiconductor industry waste gas, obtaining deoxygenated waste gas, until treated waste gas is obtained again. This application deoxygenates the waste gas before nitrogen oxides are generated. When the oxygen concentration is sufficiently low, the deoxygenated waste gas undergoes plasma treatment, deeply eliminating the conditions for nitrogen to react with oxygen to generate thermal nitrogen oxides under the high-temperature plasma treatment environment. This inhibits nitrogen oxide generation at the source, eliminating the need for reducing agents such as ammonia, and also eliminating the need for catalytic decomposition or high-temperature thermal decomposition of nitrogen oxides. Furthermore, after each waste gas treatment, the remaining service life of the deoxidizer is predicted, and if the remaining service life is insufficient to support subsequent deoxygenation treatments, the deoxidizer is promptly replaced or regenerated to ensure effective deoxygenation. The oxygen treatment process is continuous, thus ensuring the continuous operation of the waste gas treatment process. Compared to the need for ammonia and other reducing agents to be continuously and uninterruptedly input during waste gas treatment, timely replacement or regeneration of deoxidizers is obviously more sustainable for most semiconductor plants. In summary, this application utilizes pre-deoxidation to suppress the generation of nitrogen oxides at the source, and uses the remaining service life of the deoxidizer to predict and replace or regenerate the deoxidizer in a timely manner. This approach is sustainable, does not affect the operation of high-precision semiconductor equipment or product yield, and does not require consideration of the efficiency of catalytic decomposition of nitrogen oxides or the energy consumption of high-thermal decomposition of nitrogen oxides. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in this application 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 application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is one of the schematic flowcharts of the semiconductor industry waste gas treatment method provided in the embodiments of this application;

[0054] Figure 2 This is a second schematic flowchart of the semiconductor industry waste gas treatment method provided in the embodiments of this application;

[0055] Figure 3 This is the third schematic flowchart of the semiconductor industry waste gas treatment method provided in the embodiments of this application;

[0056] Figure 4 This is the fourth schematic flowchart of the semiconductor industry waste gas treatment method provided in the embodiments of this application;

[0057] Figure 5 This is the fifth schematic flowchart of the semiconductor industry waste gas treatment method provided in the embodiments of this application;

[0058] Figure 6 This is a schematic diagram of the structure of the semiconductor industry waste gas treatment system provided in the embodiments of this application;

[0059] Figure 7 This is the sixth schematic flowchart of the semiconductor industry waste gas treatment method provided in the embodiments of this application.

[0060] Figure label:

[0061] 1-Exhaust gas inlet unit; 2-First-stage deoxygenation reactor; 3-First gas concentration sensor; 4-Second-stage deoxygenation reactor; 5-Second gas concentration sensor; 6-Plasma reactor; 7-Water tank; 8-Spray device; 9-Plate heat exchanger; 10-Tail gas detection unit; 11-Outlet unit; 12-Internal low-temperature zone. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0063] It should be noted that in the description of the embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. The terms "upper," "lower," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly, for example, they can be fixed connections, detachable connections, or integral connections; they can be mechanical connections or electrical connections; they can be direct connections or indirect connections through an intermediate medium; and they can be internal connections between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0064] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, without limiting the number of objects; for example, a first object can be one or more. Furthermore, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects have an "or" relationship.

[0065] Figure 1 This is one of the schematic flowcharts of the semiconductor industry waste gas treatment method provided in the embodiments of this application. (Refer to...) Figure 1 This application provides a method for treating waste gas from the semiconductor industry, which may include:

[0066] Step 101: Control the deoxygenation reaction unit to deoxygenate the semiconductor industry waste gas to obtain deoxygenated waste gas;

[0067] Step 102: The gas concentration detection unit controls the detection of the deoxygenated waste gas to obtain the oxygen concentration;

[0068] Step 103: When the oxygen concentration is less than the first concentration threshold, control the plasma reactor to perform plasma treatment on the deoxygenated waste gas to obtain the treated waste gas.

[0069] Step 104: Predict the remaining service life of the deoxidizer in the deoxidation reaction unit. If the remaining service life is less than the service life threshold, replace or regenerate the deoxidizer and return to step 101 until the treated waste gas is obtained again.

[0070] In step 101, the deoxygenation reaction unit may include at least one deoxygenation reactor. Semiconductor industrial waste gas can be deoxygenated through a single-stage deoxygenation reactor or through multiple-stage deoxygenation reactors. No limitation is made here.

[0071] In step 102, the gas concentration detection unit may include at least one gas concentration sensor. Each stage of the deoxygenation reactor is equipped with a gas concentration sensor on its outlet pipe, so the number of deoxygenation reactors and gas concentration sensors is the same.

[0072] In step 103, the semiconductor industry waste gas is deoxygenated in the first-stage deoxygenation reactor to obtain the first-stage deoxygenated waste gas. The gas concentration sensor on the outlet pipe of the first-stage deoxygenation reactor detects the oxygen concentration in the first-stage deoxygenated waste gas. If the oxygen concentration in the first-stage deoxygenated waste gas is less than the first concentration threshold, the first-stage deoxygenated waste gas is plasma treated in the plasma reactor to obtain the treated waste gas.

[0073] If the oxygen concentration in the first-stage deoxygenated waste gas is greater than or equal to the first concentration threshold, the first-stage deoxygenated waste gas is deoxygenated through the second-stage deoxygenated reactor to obtain the second-stage deoxygenated waste gas. The gas concentration sensor on the outlet pipe of the second-stage deoxygenated reactor detects the oxygen concentration in the second-stage deoxygenated waste gas. If the oxygen concentration in the second-stage deoxygenated waste gas is less than the first concentration threshold, the second-stage deoxygenated waste gas is plasma treated through the plasma reactor to obtain the treated waste gas.

[0074] If the oxygen concentration in the second-stage deoxygenated waste gas is greater than or equal to the first concentration threshold, the second-stage deoxygenated waste gas will undergo deoxygenation treatment in the third-stage deoxygenation reactor. Subsequent treatment is the same as the first two stages, and will not be described in detail here.

[0075] As can be seen from the above, the gas concentration sensors that are activated correspond one-to-one with the deoxygenation reactors that are activated. The number of deoxygenation reactors that are activated depends on the deoxygenation effect on the semiconductor industry waste gas. If the oxygen concentration in the Nth stage deoxygenation waste gas obtained after the semiconductor industry waste gas passes through the Nth stage deoxygenation reactor is less than the first concentration threshold, then the Nth stage deoxygenation reactor needs to be activated.

[0076] It should be noted that the number of deoxygenation reactors to be started is not fixed. Since the oxygen concentration in the semiconductor industrial waste gas generated by different semiconductor processes may vary, for some semiconductor industrial waste gases, starting fewer deoxygenation reactors can make the oxygen concentration in the deoxygenated waste gas lower than the first concentration threshold, while for other semiconductor industrial waste gases, starting more deoxygenation reactors is required to make the oxygen concentration in the deoxygenated waste gas lower than the first concentration threshold. Therefore, the number of deoxygenation reactors to be started in the deoxygenation reaction unit and the number of gas concentration sensors to be started in the gas concentration detection unit can be adjusted to meet different needs. This can ensure the deoxygenation effect while avoiding the waste of energy and materials caused by starting unnecessary deoxygenation reactors and gas concentration sensors.

[0077] Furthermore, the first concentration threshold can be set according to actual needs, and is not limited here. In this embodiment, the first concentration threshold can be set to 10 ppm.

[0078] The plasma reactor generates plasma through high-voltage discharges such as DC arc discharge and microwave discharge. This plasma is rich in high-energy active particles such as high-energy electrons, particles, and free radicals. These high-energy active particles can efficiently decompose pollutant molecules such as carbon tetrafluoride and sulfur hexafluoride in deoxygenated waste gas in a high-temperature environment, thus obtaining treated waste gas.

[0079] In step 104, each stage of the deoxygenation reactor is filled with a highly efficient selective deoxygenator. The deoxygenator uses porous materials such as activated alumina and molecular sieves as carriers and is loaded with highly active metal components such as copper, manganese, and iron. These highly active metal components can preferentially react with oxygen through chemical adsorption or catalytic oxidation, and efficiently and selectively remove oxygen from the waste gas without affecting other gas components.

[0080] Furthermore, the deoxidizer in each stage of the deoxidation reactor adopts a modular and detachable design, which facilitates the replacement or regeneration of the deoxidizer. The use of regenerable deoxidizer enables the deoxidizer to be recycled, reducing the cost of consumables.

[0081] It should be noted that since all deoxygenation reactors started in the deoxygenation reaction unit participate in the deoxygenation process, it is necessary to predict the remaining service life of the deoxygenating agent in all started deoxygenation reactors. If the remaining service life of any deoxygenating agent is less than the service life threshold, it must be replaced or regenerated to avoid affecting the subsequent deoxygenation process.

[0082] Furthermore, given that semiconductor plants typically struggle to achieve continuous material feeding, it is more feasible to schedule the replacement or regeneration of any deoxidizer within the scheduled maintenance period of its respective deoxidation reactor. Therefore, the designed oxygen capacity of the deoxidizer in each stage of the deoxidation reactor must ensure its service life exceeds the maintenance cycle of that stage to achieve uninterrupted operation in coordination with production plans. For example, if the service life of the deoxidizer in a certain stage of the deoxidation reactor is one year, then the maintenance cycle for that stage of the deoxidation reactor is at most one year, meaning it can be maintained no more than once a year.

[0083] The semiconductor industry waste gas treatment method provided in this embodiment controls a deoxygenation reaction unit to deoxygenate the semiconductor industry waste gas to obtain deoxygenated waste gas. A gas concentration detection unit is controlled to detect the oxygen concentration of the deoxygenated waste gas. If the oxygen concentration is less than a first concentration threshold, a plasma reactor is controlled to perform plasma treatment on the deoxygenated waste gas to obtain treated waste gas. The remaining service life of the deoxidizer in the deoxygenation reaction unit is predicted. If the remaining service life is less than the service life threshold, the deoxidizer is replaced or regenerated. The process is repeated until the treated waste gas is obtained again. This embodiment deoxygenates the waste gas before nitrogen oxides are generated. When the oxygen concentration is sufficiently low, the deoxygenated waste gas undergoes plasma treatment, deeply eliminating the conditions for nitrogen to react with oxygen to generate thermal nitrogen oxides under the high-temperature plasma treatment environment. This inhibits nitrogen oxide generation at the source, eliminating the need for reducing agents such as ammonia, and also eliminating the need for catalytic decomposition or high-temperature thermal decomposition of nitrogen oxides. Furthermore, after each waste gas treatment, the remaining service life of the deoxidizer is predicted, and if the remaining service life is insufficient to support subsequent deoxygenation treatments, the deoxidizer is promptly replaced or regenerated to ensure effective deoxygenation. The oxygen treatment process is continuous, thus ensuring the continuous operation of the waste gas treatment process. Compared to the need for a continuous and uninterrupted input of reducing agents such as ammonia during waste gas treatment, timely replacement or regeneration of the deoxidizer is obviously more sustainable for most semiconductor plants. In summary, this embodiment utilizes pre-deoxidation to suppress the generation of nitrogen oxides at the source, and uses the remaining service life of the deoxidizer to predict and replace or regenerate the deoxidizer in a timely manner. It is sustainable, does not affect the operation of high-precision semiconductor equipment and product yield, and does not require consideration of the efficiency of catalytic decomposition of nitrogen oxides or the energy consumption of high-thermal decomposition of nitrogen oxides.

[0084] Furthermore, by avoiding the generation of nitrogen oxides, the potential costs of subsequent denitrification are also saved.

[0085] Furthermore, since no reducing agent is needed, the risk of explosion due to reagent leakage is also avoided.

[0086] Figure 2This is a second schematic flowchart of the semiconductor industry waste gas treatment method provided in the embodiments of this application. (Refer to...) Figure 2 In one embodiment, step 104 may include:

[0087] Step 201: Obtain the oxygen capacity of the deoxidizer in the deoxidation reaction unit, the real-time flow rate of the deoxidation waste gas, and the real-time oxygen concentration of the deoxidation waste gas.

[0088] Step 202: Based on the product of real-time flow rate and real-time oxygen concentration, obtain the real-time oxygen content of the deoxygenated waste gas.

[0089] Step 203: Integrate the reduction in real-time oxygen content to obtain the cumulative deoxygenation amount of the deoxygenated waste gas;

[0090] Step 204: Based on the difference between the oxygen loading capacity and the cumulative deoxygenation amount, obtain the theoretical remaining oxygen capacity of the deoxidizer;

[0091] Step 205: Based on the difference between the theoretical remaining oxygen capacity and the actual remaining oxygen capacity, predict the remaining service life of the deoxidizer.

[0092] For each deoxygenation reactor started in the deoxygenation reaction unit, the following steps are performed:

[0093] In step 201, the oxygen capacity of the deoxidizing agent in the deoxidizing reactor, the real-time flow rate of the deoxidizing waste gas at the outlet of the deoxidizing reactor, and the real-time oxygen concentration are obtained.

[0094] In step 202, the product of the real-time flow rate and the real-time oxygen concentration is calculated to obtain the real-time oxygen content of the deoxygenated waste gas at the outlet of the deoxygenation reactor.

[0095] In step 203, due to the continuous deoxygenation of the deoxygenation reactor, the real-time oxygen content in the deoxygenated waste gas at its outlet is constantly decreasing. The amount of decrease is the amount of deoxygenation. Therefore, the cumulative amount of deoxygenation of the deoxygenated waste gas can be obtained by continuously accumulating this amount of decrease through integral calculation.

[0096] In step 204, the oxygen loading capacity is the theoretical amount of oxygen that the deoxidizer can deoxygenate, and the cumulative deoxygenation amount is the amount of oxygen that the deoxidizer has currently deoxygenated. The difference between the two is the theoretical remaining amount of oxygen that the deoxidizer can deoxygenate, which is also the theoretical remaining oxygen capacity.

[0097] In step 205, the remaining oxygen capacity of the deoxidizer is the key to predicting the remaining service life of the deoxidizer. However, in the actual use of the deoxidizer, there may be a deviation between the theoretical remaining oxygen capacity and the actual remaining oxygen capacity due to various reasons. Therefore, it is necessary to consider the impact of this deviation on the prediction in order to improve the accuracy of the prediction of the remaining service life of the deoxidizer.

[0098] This embodiment calculates the real-time oxygen content using the real-time flow rate and real-time oxygen concentration of the deoxygenated waste gas at the outlet of the deoxygenation reactor. Then, it integrates the decrease in real-time oxygen content to obtain the cumulative deoxygenation amount of the deoxygenated waste gas. This allows for the calculation of the difference between the oxygen loading capacity of the deoxidizer and the cumulative deoxygenation amount, yielding the theoretical remaining oxygen capacity. By taking into account the impact of the deviation between the theoretical and actual remaining oxygen capacity on the prediction, the remaining service life of the deoxidizer is predicted, ultimately achieving an accurate prediction of the remaining service life.

[0099] Figure 3 This is the third schematic flowchart of the semiconductor industry waste gas treatment method provided in the embodiments of this application. (Refer to...) Figure 3 In one embodiment, step 205 may include:

[0100] Step 301: Obtain the temperature of the reaction bed in the deoxygenation reaction unit;

[0101] Step 302: When the difference between the theoretical residual oxygen capacity and the actual residual oxygen capacity is greater than the difference threshold, the theoretical residual oxygen capacity is corrected based on the decay relationship between the reaction bed temperature and the residual oxygen capacity of the deoxidizer to obtain the corrected residual oxygen capacity.

[0102] Step 303: Based on the corrected remaining oxygen capacity, predict the remaining service life of the deoxidizer.

[0103] For each deoxygenation reactor started in the deoxygenation reaction unit, the following steps are performed:

[0104] In step 301, the reaction bed temperature of the deoxidation reactor is obtained. The reaction bed temperature is the average temperature of each measuring point in the fixed layer formed by the deoxidizer inside the deoxidation reactor.

[0105] In steps 302 to 303, according to the Arrhenius equation, there is a positive relationship between the rate of a chemical reaction and temperature. That is, the higher the reaction temperature, the faster the reaction rate. The faster the reaction rate, the more oxygen capacity is consumed in the deoxidation reaction of the deoxidizer, and the smaller the remaining oxygen capacity. That is, there is a decaying relationship between the reaction bed temperature and the remaining oxygen capacity. This decaying relationship can be indirectly obtained based on the Arrhenius equation. Based on this, the decay effect of the reaction bed temperature on the remaining oxygen capacity is obtained. This effect is then added to the theoretical remaining oxygen capacity to complete the correction and obtain the corrected remaining oxygen capacity. The remaining service life of the deoxidizer is then predicted using the corrected remaining oxygen capacity.

[0106] It should be noted that although the actual remaining oxygen capacity has been observed at this time, it can not be directly used to predict the remaining service life of the deoxidizer because it is affected by various observation conditions and may fluctuate under different observation conditions. However, it can be used as a reference to evaluate the accuracy of the theoretical remaining oxygen capacity. When the deviation between the theoretical remaining oxygen capacity and the actual remaining oxygen capacity under a certain observation condition is large, it is necessary to consider correcting the theoretical remaining oxygen capacity.

[0107] Furthermore, if the remaining service life of the deoxidizer is predicted to be less than the service life threshold, an early warning and maintenance plan prompt can be issued so that the deoxidizer can be updated or regenerated in a timely manner.

[0108] In this embodiment, when the deviation between the theoretical and actual residual oxygen capacity is large, the Arrhenius equation based on reaction kinetics is used to compensate for the attenuation of the theoretical residual oxygen capacity, thereby obtaining a more accurate residual oxygen capacity and achieving accurate prediction of the remaining service life of the deoxidizer.

[0109] In one embodiment, step 103 may include:

[0110] 1. When the oxygen concentration is less than the second concentration threshold and the pollutant concentration in the deoxygenated waste gas is less than the third concentration threshold, control the plasma reactor to reduce the energy input in order to perform plasma treatment on the deoxygenated waste gas.

[0111] 2. When the oxygen concentration is greater than or equal to the second concentration threshold, or the pollutant concentration in the deoxygenated waste gas is greater than or equal to the third concentration threshold, control the plasma reactor to increase the energy input in order to perform plasma treatment on the deoxygenated waste gas.

[0112] The second concentration threshold is less than the first concentration threshold.

[0113] The second and third concentration thresholds can be set according to actual needs and are not limited here. In this embodiment, the second concentration threshold can be set to 5 ppm, then:

[0114] If the oxygen concentration measured at the outlet of the deoxygenation reactor is less than 5 ppm and the pollutant concentration is low, it indicates that the oxygen concentration in the plasma reactor is extremely low and the energy required for pollutant treatment is also low. Therefore, the energy input can be appropriately reduced, and priority should be given to ensuring the pollutant decomposition efficiency, thereby achieving energy saving.

[0115] If the oxygen concentration measured at the deoxygenator outlet is greater than or equal to 5 ppm (and less than 10 ppm), or if the pollutant concentration is high, it indicates that the oxygen concentration in the plasma reactor is trending dangerously, or that the energy required for pollutant treatment is also high. It is necessary to increase the energy input, suppress the generation of nitrogen oxides, and ensure the efficiency of pollutant decomposition.

[0116] The energy input of a plasma reactor mainly consists of discharge power and energy density.

[0117] This embodiment detects the oxygen and pollutant concentrations in the deoxygenated waste gas entering the plasma reactor, and dynamically optimizes the discharge power and / or energy density of the plasma reactor based on changes in these concentrations. This changes the traditional mode of operation with a fixed high energy input and achieves "energy allocation on demand." While ensuring the treatment effect, it significantly reduces the treatment energy consumption and lowers the operating cost.

[0118] Figure 4 This is the fourth schematic flowchart of the semiconductor industry waste gas treatment method provided in the embodiments of this application. (Refer to...) Figure 4 In one embodiment, step 103 may be followed by:

[0119] Step 401: Control the spray device to spray and wash the treated waste gas to obtain the remaining tail gas;

[0120] Step 402: Control the exhaust gas detection unit to detect the remaining exhaust gas and obtain the nitrogen oxide concentration;

[0121] Step 403: If the nitrogen oxide concentration exceeds the standard, the alarm system will be triggered;

[0122] Step 404: If the nitrogen oxide concentration does not exceed the standard, the remaining exhaust gas shall be discharged.

[0123] In step 401, the treated waste gas includes gases that are easily soluble in water, such as carbon dioxide, hydrogen fluoride, and sulfur dioxide. Spraying and washing the waste gas with water can dissolve these gases in the water, thereby removing them and obtaining the remaining tail gas.

[0124] In steps 402 to 404, the concentration of nitrogen oxides in the remaining exhaust gas is detected to determine whether the concentration exceeds the standard. If the concentration exceeds the standard, the alarm system is triggered to remind the operator to intervene and check. If the concentration does not exceed the standard, the gas is discharged.

[0125] This embodiment utilizes the characteristic that the gases contained in the treated waste gas are easily soluble in water. These gases are removed by spray washing. The nitrogen oxide concentration of the remaining tail gas is then tested before emission. Only when it meets the standard is it allowed to be emitted, thus preventing pollution to the external environment.

[0126] Figure 5 This is the fifth schematic flowchart of the semiconductor industry waste gas treatment method provided in the embodiments of this application. (Refer to...) Figure 5 In one embodiment, step 401 may be followed by:

[0127] Step 501: Control the plate heat exchanger to exchange heat and cool down the residual liquid after spray washing, and obtain the cooled liquid.

[0128] Step 502: Control the plate heat exchanger to deliver the cooled liquid as spray liquid to the spraying device.

[0129] Since gases such as carbon dioxide, hydrogen fluoride, and sulfur dioxide release a large amount of heat when dissolved in water, the residual liquid after spray washing is at a high temperature. Therefore, the residual liquid can be cooled by heat exchange first, and then the cooled liquid can be used as spray liquid to be transported to the spraying device for the next spraying operation.

[0130] In this embodiment, the residual liquid after spray washing is cooled by heat exchange before being transported to the spraying device, so that the residual liquid can be recycled as spraying liquid, saving the amount of spraying liquid used.

[0131] Figure 6 This is a schematic diagram of the semiconductor industry waste gas treatment system provided in an embodiment of this application. (Refer to...) Figure 6 This application provides a semiconductor industry waste gas treatment system, which may include: an intelligent control unit, a deoxygenation reaction unit, a gas concentration detection unit, and a plasma reactor 6;

[0132] Intelligent control unit, used for:

[0133] The deoxygenation reaction unit is controlled to deoxygenate the waste gas from the semiconductor industry, resulting in deoxygenated waste gas.

[0134] The control gas concentration detection unit detects the deoxygenated waste gas to obtain the oxygen concentration;

[0135] When the oxygen concentration is less than the first concentration threshold, the plasma reactor 6 is controlled to perform plasma treatment on the deoxygenated waste gas to obtain the treated waste gas.

[0136] The remaining service life of the deoxidizer in the deoxidation reaction unit is predicted. If the remaining service life is less than the service life threshold, the deoxidizer is replaced or regenerated, and the process is repeated to control the deoxidation reaction unit to deoxidize the semiconductor industry waste gas and obtain deoxidized waste gas, until the treated waste gas is obtained again.

[0137] Reference Figure 6The deoxygenation reaction unit includes two-stage deoxygenation reactors, and the gas concentration measurement unit includes two gas concentration sensors. The first gas concentration sensor 3 is located between the outlet pipe of the first-stage deoxygenation reactor 2 and the inlet pipe of the second-stage deoxygenation reactor 4, and the second gas concentration sensor 5 is located between the outlet pipe of the second-stage deoxygenation reactor 4 and the inlet pipe of the plasma reactor 6.

[0138] Furthermore, the intelligent control unit is connected to two gas concentration sensors, and its built-in embedded system integrates two major calculation algorithm modules, which are used for predicting the remaining service life of the deoxidizer and for adaptive adjustment of the energy input of the plasma reactor, respectively.

[0139] Furthermore, the system may also include an exhaust gas inlet unit 1 for conveying semiconductor industry exhaust gas to the first-stage deoxygenation reactor 2.

[0140] Furthermore, if oxygen needs to be introduced into the plasma reactor 6 to completely treat part of the waste gas, it is possible to introduce additional air or oxygen into the internal low-temperature zone 12. The temperature of the internal low-temperature zone 12 is about 400-500℃. At this temperature, the oxidation treatment of the waste gas can be satisfied, while the generation of high-temperature nitrogen oxides can be avoided.

[0141] The semiconductor industrial waste gas treatment system provided in this embodiment includes an intelligent control unit that controls a deoxygenation reaction unit to deoxygenate the semiconductor industrial waste gas, resulting in deoxygenated waste gas. A gas concentration detection unit is then used to detect the oxygen concentration in the deoxygenated waste gas. If the oxygen concentration is less than a first concentration threshold, a plasma reactor is controlled to perform plasma treatment on the deoxygenated waste gas, resulting in treated waste gas. The remaining service life of the deoxidizer in the deoxygenation reaction unit is predicted. If the remaining service life is less than a service life threshold, the deoxidizer is replaced or regenerated. The system then returns to the step of controlling the deoxygenation reaction unit to deoxygenate the semiconductor industrial waste gas, resulting in deoxygenated waste gas, until treated waste gas is obtained again. This embodiment deoxygenates the waste gas before nitrogen oxides are generated. When the oxygen concentration is sufficiently low, the deoxygenated waste gas undergoes plasma treatment, deeply eliminating the conditions for nitrogen to react with oxygen to generate thermal nitrogen oxides under the high-temperature plasma treatment environment. This inhibits nitrogen oxide generation at the source, eliminating the need for reducing agents such as ammonia, and also eliminating the need for catalytic decomposition or high-temperature thermal decomposition of nitrogen oxides. Furthermore, after each waste gas treatment, the remaining service life of the deoxidizer is predicted, and if the remaining service life is insufficient to support subsequent deoxygenation treatments, the deoxidizer is promptly replaced or regenerated to ensure effective deoxygenation. The oxygen treatment process is continuous, thus ensuring the continuous operation of the waste gas treatment process. Compared to the need for a continuous and uninterrupted input of reducing agents such as ammonia during waste gas treatment, timely replacement or regeneration of the deoxidizer is obviously more sustainable for most semiconductor plants. In summary, this embodiment utilizes pre-deoxidation to suppress the generation of nitrogen oxides at the source, and uses the remaining service life of the deoxidizer to predict and replace or regenerate the deoxidizer in a timely manner. It is sustainable, does not affect the operation of high-precision semiconductor equipment and product yield, and does not require consideration of the efficiency of catalytic decomposition of nitrogen oxides or the energy consumption of high-thermal decomposition of nitrogen oxides.

[0142] Furthermore, the deoxygenation reaction unit and gas concentration detection unit of this embodiment can be easily integrated into the front end of the plasma reactor without requiring large-scale modifications to the existing system, making it particularly suitable for technological upgrades in space-constrained semiconductor factories and other similar facilities.

[0143] Reference Figure 6 In one embodiment, the system may further include: a spray device 8 and an exhaust gas detection unit 10;

[0144] The intelligent control unit is also used for:

[0145] The spray device 8 is controlled to spray and wash the treated waste gas to obtain the remaining tail gas.

[0146] The exhaust gas detection unit 10 controls the remaining exhaust gas to obtain the nitrogen oxide concentration;

[0147] If the nitrogen oxide concentration exceeds the standard, the alarm system will be triggered;

[0148] If the nitrogen oxide concentration does not exceed the standard, the remaining exhaust gas will be emitted.

[0149] The system may also include a water tank 7 and an outlet unit 11. The water tank 7 is installed on the outlet pipe of the plasma reactor 6, the spray device 8 is installed in the water tank 7, and the exhaust gas detection unit 10 is installed between the gas outlet pipe of the water tank 7 and the inlet pipe of the outlet unit 11. The outlet unit 11 is used to discharge the remaining exhaust gas when the exhaust gas detection unit 10 detects that the concentration of nitrogen oxides in the remaining exhaust gas does not exceed the standard.

[0150] This embodiment utilizes the characteristic that the gases contained in the treated waste gas are easily soluble in water. These gases are removed by spray washing. The nitrogen oxide concentration of the remaining tail gas is then tested before emission. Only when it meets the standard is it allowed to be emitted, thus preventing pollution to the external environment.

[0151] Reference Figure 6 In one embodiment, the system may further include: a plate heat exchanger 9;

[0152] The intelligent control unit is also used for:

[0153] The plate heat exchanger 9 is controlled to exchange heat and cool down the residual liquid after spray washing, so as to obtain the cooled liquid.

[0154] The plate heat exchanger 9 controls the cooling liquid to be transported to the spraying device 8 as the spraying liquid;

[0155] The plate heat exchanger 9 is located between the liquid outlet pipe of the water tank 7 and the inlet pipe of the spray device 8.

[0156] In this embodiment, the residual liquid after spray washing is cooled by heat exchange before being transported to the spraying device, so that the residual liquid can be recycled as spraying liquid, saving the amount of spraying liquid used.

[0157] Figure 7 This is the sixth schematic flowchart of the semiconductor industry waste gas treatment method provided in the embodiments of this application. (Refer to...) Figure 7 In one embodiment, the entire process of the semiconductor industry waste gas treatment method of this application is briefly described in conjunction with the semiconductor industry waste gas treatment system of this application:

[0158] 1. The intelligent control unit controls the exhaust gas inlet unit 1 to introduce semiconductor industry exhaust gas containing nitrogen N2, oxygen O2, carbon tetrafluoride CF4, sulfur hexafluoride SF6 and other gases into the first-stage deoxygenation reactor 2 for preliminary deoxygenation.

[0159] The reaction temperature of the deoxidizer in the deoxidation reactor can be set to around 300℃. Deoxidizers with lower operating temperatures should be selected as much as possible to reduce total energy consumption. Deoxidizers with a larger deoxidation capacity, generally up to 1500ml / g, can reduce the integrated size.

[0160] The core reaction can be represented as: 4M + O2 → 2M2O or 2M2O + O2 → 4MO, where M can be copper, Cu, etc.

[0161] 2. The intelligent control unit controls the first gas concentration sensor 3 to detect the oxygen concentration in the deoxygenated waste gas after treatment by the first-stage deoxygenation reactor 2 in real time.

[0162] 3. The intelligent control unit compares the detected oxygen concentration with the first concentration threshold (i.e., 10 ppm);

[0163] 4.1 If the oxygen concentration is less than the first concentration threshold, the deoxygenated waste gas is directly introduced into the plasma reactor 6 for treatment.

[0164] At this time, the deoxygenated exhaust gas is in an oxygen-deficient condition, which can significantly reduce the generation of nitrogen oxides.

[0165] Plasma reactor 6 breaks down and oxidizes pollutant molecules such as CF4 and SF6, generating gases that are easily soluble in water, such as carbon dioxide (CO2), hydrogen fluoride (HF), and sulfur dioxide (SO2).

[0166] 4.2 If the oxygen concentration is greater than or equal to the first concentration threshold, the second-stage deoxygenation reactor 4 is started to allow the waste gas to undergo deep deoxygenation treatment. After the second gas concentration sensor 5 detects that the oxygen concentration is less than the first concentration threshold, the deoxygenated waste gas is then introduced into the plasma reactor 6 for further treatment.

[0167] During the treatment process of plasma reactor 6, the intelligent control unit predicts the remaining service life of the deoxidizer. If the remaining service life is less than the service life threshold, the deoxidizer is replaced or regenerated, and the energy input of plasma reactor 6 is adaptively adjusted based on the oxygen concentration and pollutant concentration in the deoxidized waste gas.

[0168] 5. The waste gas treated by the plasma reactor 6 is introduced into the water tank 7. The intelligent control unit controls the spray device 8 to spray and wash it. CO2, HF, SO2 and other gases are dissolved in water and removed, and the remaining tail gas is obtained. At the same time, the plate heat exchanger 9 is controlled to exchange heat and cool the residual body fluid before it is transported to the spray device 8.

[0169] 6. The intelligent control unit controls the exhaust gas detection unit 10 to detect the remaining exhaust gas. If the nitrogen oxide concentration meets the standard, that is, less than or equal to 50mg / m³, the outlet unit 11 is controlled to emit the gas. If the nitrogen oxide concentration does not meet the standard, the alarm system is triggered to remind the operator to intervene and check.

[0170] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application 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. Such 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 this application.

Claims

1. A method for treating waste gas from the semiconductor industry, characterized in that, include: The deoxygenation reaction unit is controlled to deoxygenate the waste gas from the semiconductor industry, resulting in deoxygenated waste gas. The control gas concentration detection unit detects the deoxygenated waste gas to obtain the oxygen concentration; When the oxygen concentration is less than the first concentration threshold, the plasma reactor is controlled to perform plasma treatment on the deoxygenated waste gas to obtain the treated waste gas. Predicting the remaining service life of the deoxidizer in the deoxidation reaction unit includes: The oxygen capacity of the deoxidizing agent in the deoxidation reaction unit, the real-time flow rate of the deoxidation waste gas, and the real-time oxygen concentration of the deoxidation waste gas are obtained. The real-time oxygen content of the deoxygenated waste gas is obtained by multiplying the real-time flow rate and the real-time oxygen concentration. The cumulative deoxygenation amount of the deoxygenated waste gas is obtained by integrating the reduction in the real-time oxygen content. Based on the difference between the oxygen loading capacity and the cumulative deoxygenation amount, the theoretical residual oxygen capacity of the deoxidizer is obtained; The remaining service life of the deoxidizer is predicted based on the difference between the theoretical remaining oxygen capacity and the actual remaining oxygen capacity. If the remaining service life is less than the service life threshold, the deoxidizer is replaced or regenerated, and the process is repeated in the deoxidation reaction unit to deoxidize the semiconductor industry waste gas, obtaining deoxidized waste gas, until the treated waste gas is obtained again.

2. The semiconductor industry waste gas treatment method according to claim 1, characterized in that, The prediction of the remaining service life of the deoxidizer based on the difference between the theoretical and actual remaining oxygen capacity includes: Obtain the reaction bed temperature of the deoxygenation reaction unit; If the difference between the theoretical residual oxygen capacity and the actual residual oxygen capacity is greater than the difference threshold, the theoretical residual oxygen capacity is corrected based on the decay relationship between the reaction bed temperature and the residual oxygen capacity of the deoxidizer to obtain the corrected residual oxygen capacity. Based on the corrected remaining oxygen capacity, the remaining service life of the deoxidizer is predicted.

3. The semiconductor industry waste gas treatment method according to claim 1, characterized in that, The controlled plasma reactor performs plasma treatment on the deoxygenated waste gas, including: When the oxygen concentration is less than the second concentration threshold and the pollutant concentration in the deoxygenated waste gas is less than the third concentration threshold, the plasma reactor is controlled to reduce the energy input in order to perform plasma treatment on the deoxygenated waste gas. The second concentration threshold is less than the first concentration threshold.

4. The semiconductor industry waste gas treatment method according to claim 1, characterized in that, The controlled plasma reactor performs plasma treatment on the deoxygenated waste gas, including: When the oxygen concentration is greater than or equal to a second concentration threshold, or when the pollutant concentration in the deoxygenated waste gas is greater than or equal to a third concentration threshold, the plasma reactor is controlled to increase the energy input to perform plasma treatment on the deoxygenated waste gas.

5. The semiconductor industry waste gas treatment method according to claim 1, characterized in that, After the treated waste gas is obtained, the process includes: The spray device is controlled to spray and wash the treated waste gas to obtain residual exhaust gas. The exhaust gas detection unit controls the remaining exhaust gas to detect the nitrogen oxide concentration; If the nitrogen oxide concentration exceeds the standard, an alarm system will be triggered; If the nitrogen oxide concentration does not exceed the standard, the remaining exhaust gas will be emitted.

6. The semiconductor industry waste gas treatment method according to claim 5, characterized in that, After the controlled spraying device sprays and washes the treated waste gas, it includes: The plate heat exchanger is controlled to exchange heat and cool down the residual liquid after spray washing, so as to obtain the cooled liquid. The plate heat exchanger is controlled to deliver the cooled liquid as a spraying liquid to the spraying device.

7. A semiconductor industry waste gas treatment system, characterized in that, include: Intelligent control unit, deoxygenation reaction unit, gas concentration detection unit, and plasma reactor; The intelligent control unit is used to execute the semiconductor industry waste gas treatment method according to claim 1, including: The deoxygenation reaction unit is controlled to deoxygenate the semiconductor industry waste gas to obtain deoxygenated waste gas. The gas concentration detection unit is controlled to detect the deoxygenated waste gas and obtain the oxygen concentration; When the oxygen concentration is less than a first concentration threshold, the plasma reactor is controlled to perform plasma treatment on the deoxygenated waste gas to obtain treated waste gas; The remaining service life of the deoxidizer in the deoxidation reaction unit is predicted. If the remaining service life is less than the service life threshold, the deoxidizer is replaced or regenerated, and the process returns to controlling the deoxidation reaction unit to deoxidize the semiconductor industrial waste gas to obtain deoxidized waste gas, until the treated waste gas is obtained again.

8. The semiconductor industry waste gas treatment system according to claim 7, characterized in that, Also includes: Spraying device and exhaust gas detection unit; The intelligent control unit is also used for: The spraying device is controlled to spray and wash the treated waste gas to obtain residual exhaust gas. The exhaust gas detection unit is controlled to detect the remaining exhaust gas and obtain the nitrogen oxide concentration; If the nitrogen oxide concentration exceeds the standard, an alarm system will be triggered; If the nitrogen oxide concentration does not exceed the standard, the remaining exhaust gas will be emitted.

9. The semiconductor industry waste gas treatment system according to claim 8, characterized in that, Also includes: Plate heat exchanger; The intelligent control unit is also used for: The plate heat exchanger is controlled to exchange heat and cool down the residual liquid after spray washing, so as to obtain the cooled liquid. The plate heat exchanger is controlled to deliver the cooled liquid as a spraying liquid to the spraying device.

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