Nitrification process control method, device and equipment, storage medium and program product

Abstract

The invention relates to a nitration process control method and device, computer equipment, a computer readable storage medium and a computer program product. The nitration process comprises a nitration reaction process and a catalyst recovery process, a catalyst recovered in the catalyst recovery process is circularly applied to the nitration reaction process, and the method comprises the following steps: when it is detected that the reaction temperature value of the nitration reaction process exceeds a preset reaction temperature target range, starting the nitration reaction process, acquiring a recovery temperature set value and a recovery pressure set value in the catalyst recovery process; adjusting the recovery temperature set value according to the reaction temperature value and a preset reaction temperature target range; and adjusting the recovery pressure set value according to the adjusted recovery temperature set value and a preset catalyst concentration target range. By adopting the method, the generation of byproducts in the nitration reaction process can be effectively reduced.

Description

Technical Field

[0001] The present application relates to the technical field of nitrification processes, and particularly to a nitrification process control method, device, computer device, computer-readable storage medium, and computer program product. Background Art

[0002] Nitro compounds, as intermediates and organic synthesis reagents in industries such as pharmaceuticals, dyes, spices, and explosives, are important chemical raw materials indispensable to the modern chemical industry and an essential part of the development of the national economy. The nitrification process is the main process for producing nitro compounds, and nitro groups can be introduced into organic compound molecules through chemical reactions.

[0003] In traditional technologies, operators manually control reaction conditions based on experience.

[0004] However, the nitrification reaction process is affected by multiple reaction conditions, and there is a coupling effect between reaction conditions. Adjusting one reaction condition may affect other unadjusted reaction conditions. The manual adjustment method is difficult to capture the coupling effect between each reaction condition, easily leading to an increase in by-products. In severe cases, it will cause emulsification problems in the downstream ammonia washing process, seriously affecting the stable operation of the device. Summary of the Invention

[0005] Based on this, in view of the above technical problems, it is necessary to provide a nitrification process control method, device, computer device, computer-readable storage medium, and computer program product that can reduce by-products.

[0006] In a first aspect, the present application provides a nitrification process control method. The nitrification process includes a nitrification reaction process and a catalyst recovery process, and the catalyst recovered in the catalyst recovery process is recycled and applied to the nitrification reaction process. The method includes:

[0007] When it is detected that the reaction temperature value of the nitrification reaction process exceeds the preset reaction temperature target range, obtain the recovery temperature set value and the recovery pressure set value of the catalyst recovery process;

[0008] According to the reaction temperature value and the preset reaction temperature target range, adjust the recovery temperature set value so that the reaction temperature value changes in a direction closer to the preset reaction temperature target range;

[0009] According to the adjusted recovery temperature set value and the preset catalyst concentration target range, adjust the recovery pressure set value so that the catalyst concentration value in the catalyst recovery process changes in a direction closer to the preset catalyst concentration target range.

[0010] In one of the embodiments, adjusting the recovery temperature set value according to the reaction temperature value and the preset reaction temperature target range includes:

[0011] Detect the reaction temperature deviation value based on the reaction temperature value and the preset reaction temperature target range;

[0012] Adjust the set value of the recovery temperature based on the reaction temperature deviation value and the preset temperature transfer function.

[0013] In one embodiment, adjusting the set value of the recovery temperature based on the reaction temperature deviation value and the preset temperature transfer function includes:

[0014] Detect the target temperature adjustment value in the catalyst recovery process based on the reaction temperature deviation value and the preset temperature transfer function;

[0015] Determine the sum of the set value of the recovery temperature and the target temperature adjustment value as the initial temperature update value;

[0016] When the initial temperature update value is within the preset temperature adjustment range, set the initial temperature update value as the new set value of the recovery temperature;

[0017] When the initial temperature update value is higher than the upper limit value of the preset temperature adjustment range, set the upper limit value of the preset temperature adjustment range as the new set value of the recovery temperature;

[0018] When the initial temperature update value is lower than the lower limit value of the preset temperature adjustment range, set the lower limit value of the preset temperature adjustment range as the new set value of the recovery temperature.

[0019] In one embodiment, adjusting the set value of the recovery pressure according to the adjusted set value of the recovery temperature and the preset catalyst concentration target range includes:

[0020] Detect the initial catalyst concentration value according to the new set value of the recovery temperature and the set value of the recovery pressure;

[0021] When the initial catalyst concentration value exceeds the preset catalyst concentration target range, detect the catalyst concentration deviation value based on the initial catalyst concentration value and the preset catalyst concentration target range;

[0022] Adjust the set value of the recovery pressure based on the catalyst concentration deviation value and the preset pressure transfer function.

[0023] In one embodiment, adjusting the set value of the recovery pressure based on the catalyst concentration deviation value and the preset pressure transfer function includes:

[0024] Detect the target pressure adjustment value in the catalyst recovery process based on the catalyst concentration deviation value and the preset concentration transfer function;

[0025] Determine the sum of the set value of the recovery pressure and the target pressure adjustment value as the initial pressure update value;

[0026] When the initial pressure update value is within the preset pressure adjustment range, set the initial pressure update value as the new recovery pressure set value;

[0027] When the initial pressure update value is higher than the upper limit value of the preset pressure adjustment range, set the upper limit value of the preset pressure adjustment range as the new recovery pressure set value;

[0028] When the initial pressure update value is lower than the lower limit value of the preset pressure adjustment range, set the lower limit value of the preset pressure adjustment range as the new recovery pressure set value.

[0029] In one embodiment, the reaction temperature value includes a predicted reaction temperature value; before obtaining the recovery temperature set value and the recovery pressure set value in the catalyst recovery process when it is detected that the reaction temperature value in the nitration reaction process exceeds the preset reaction temperature target range, the method further includes:

[0030] Obtain the measured reaction temperature value of the nitration reaction process at the current time step;

[0031] Based on the measured reaction temperature value and the temperature-time model corresponding to the nitration reaction process, detect the predicted reaction temperature value of the nitration reaction process at the next time step;

[0032] Detect whether the predicted reaction temperature value exceeds the preset reaction temperature target range.

[0033] In a second aspect, the present application further provides a nitration process control device. The nitration process includes a nitration reaction process and a catalyst recovery process. The catalyst recovered in the catalyst recovery process is recycled to the nitration reaction process. The device includes:

[0034] An acquisition module, configured to acquire the reaction temperature value of the nitration reaction process, as well as the recovery temperature set value and the recovery pressure set value of the catalyst recovery process;

[0035] A first setting module, configured to, when the reaction temperature value exceeds the preset reaction temperature target range, adjust the recovery temperature set value according to the reaction temperature value and the preset reaction temperature target range, so that the reaction temperature value changes in a direction closer to the preset reaction temperature target range;

[0036] A second setting module, configured to adjust the recovery pressure set value according to the adjusted recovery temperature set value and the preset catalyst concentration target range, so that the catalyst concentration value in the catalyst recovery process changes in a direction closer to the preset catalyst concentration target range.

[0037] In a third aspect, the present application further provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0038] When it is detected that the reaction temperature value in the nitrification reaction process exceeds the preset reaction temperature target range, obtain the recovery temperature set value and the recovery pressure set value in the catalyst recovery process;

[0039] According to the reaction temperature value and the preset reaction temperature target range, adjust the recovery temperature set value so that the reaction temperature value changes in the direction of approaching the preset reaction temperature target range;

[0040] According to the adjusted recovery temperature set value and the preset catalyst concentration target range, adjust the recovery pressure set value so that the catalyst concentration value in the catalyst recovery process changes in the direction of approaching the preset catalyst concentration target range.

[0041] In a fourth aspect, the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0042] When it is detected that the reaction temperature value in the nitrification reaction process exceeds the preset reaction temperature target range, obtain the recovery temperature set value and the recovery pressure set value in the catalyst recovery process;

[0043] According to the reaction temperature value and the preset reaction temperature target range, adjust the recovery temperature set value so that the reaction temperature value changes in the direction of approaching the preset reaction temperature target range;

[0044] According to the adjusted recovery temperature set value and the preset catalyst concentration target range, adjust the recovery pressure set value so that the catalyst concentration value in the catalyst recovery process changes in the direction of approaching the preset catalyst concentration target range.

[0045] In a fifth aspect, the present application also provides a computer program product, including a computer program. When the computer program is executed by a processor, the following steps are implemented:

[0046] When it is detected that the reaction temperature value in the nitrification reaction process exceeds the preset reaction temperature target range, obtain the recovery temperature set value and the recovery pressure set value in the catalyst recovery process;

[0047] According to the reaction temperature value and the preset reaction temperature target range, adjust the recovery temperature set value so that the reaction temperature value changes in the direction of approaching the preset reaction temperature target range;

[0048] According to the adjusted recovery temperature set value and the preset catalyst concentration target range, adjust the recovery pressure set value so that the catalyst concentration value in the catalyst recovery process changes in the direction of approaching the preset catalyst concentration target range.

[0049] The above nitrification process control method, device, computer equipment, computer-readable storage medium, and computer program product are applied to a nitrification process with a catalyst recovery process. In this case, the nitrification process includes a nitrification reaction process and a catalyst recovery process, and the catalyst recovered in the catalyst recovery process is recycled and applied to the nitrification reaction process. By obtaining the recovery temperature set value and the recovery pressure set value of the catalyst recovery process when it is detected that the reaction temperature value of the nitrification reaction process exceeds the preset reaction temperature target range, and adjusting the recovery temperature set value according to the reaction temperature value and the preset reaction temperature target range, so that the reaction temperature value changes in the direction of approaching the preset reaction temperature target range, it realizes the adjustment of the recovery temperature set value of the catalyst recovery process when the reaction temperature value in the nitrification reaction process exceeds the range, in order to achieve the purpose of controlling the reaction temperature value of the nitrification reaction process. However, the adjustment of the recovery temperature set value of the catalyst recovery process will affect the concentration of the recovered catalyst. Therefore, further adjust the recovery pressure set value according to the adjusted recovery temperature set value and the preset catalyst concentration target range, so that the catalyst concentration value in the catalyst recovery process changes in the direction of approaching the preset catalyst concentration target range. By synchronously adjusting the recovery pressure set value of the catalyst recovery process, effective control of the catalyst concentration can be achieved. Compared with the way that operators manually control the reaction conditions according to experience, this application can more accurately and efficiently capture the abnormality of the nitrification process by automatically monitoring the reaction temperature of the nitrification reaction process, and in response to this abnormality, adaptively adjust the recovery temperature set value and the recovery pressure set value of the catalyst recovery process, fully considering the mutual coupling effects of the nitrification reaction temperature, the catalyst recovery temperature, the catalyst recovery pressure, and the catalyst concentration. It can realize the synchronous coordinated control of the reaction temperature of the nitrification reaction process and the catalyst concentration of the catalyst recovery process, can more accurately and timely eliminate the reaction temperature abnormality, and can effectively predict and prevent the deviation of the catalyst concentration, effectively reducing the by-products generated due to the reaction temperature abnormality and the catalyst concentration deviation, and improving the stability of the nitrification reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the following will briefly introduce the drawings required to be used in the description of the embodiments of the present application or the related art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0051] Figure 1 It is a schematic flowchart of the nitrification process control method in an embodiment;

[0052] Figure 2Schematic flowchart of the nitrification process control method in another embodiment;

[0053] Figure 3 Schematic structural diagram of the nitrification process system in one embodiment;

[0054] Figure 4 Block diagram of the structure of the nitrification process control device in one embodiment;

[0055] Figure 5 Internal structure diagram of a computer device in one embodiment. Detailed implementation manners

[0056] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0057] Nitro compounds, as intermediates and organic synthesis reagents in industries such as pharmaceuticals, dyes, fragrances, and explosives, are important chemical raw materials indispensable to modern chemical industry and an essential part of the national economic development. The nitrification process is the main process for producing nitro compounds and can introduce nitro groups into organic compound molecules through chemical reactions.

[0058] In the traditional technology, the reaction conditions are manually controlled by operators based on experience. However, the nitrification reaction process is affected by multiple reaction conditions, and there is a coupling effect between the reaction conditions. Adjusting one reaction condition may affect other unadjusted reaction conditions. The manual adjustment method is difficult to capture the coupling effect between each reaction condition, which easily leads to an increase in by-products. In severe cases, it will cause emulsification problems in the downstream ammonia washing process, seriously affecting the stable operation of the device.

[0059] Catalysts are often used in nitrification reactions. Theoretically, catalysts are not consumed during the nitrification reaction process. Therefore, in order to save costs, many production enterprises will set up a catalyst recycling device, such as a flash evaporator, after the nitrification reaction. After the nitrification reaction, first collect the mixture containing the catalyst, and then remove or separate other components in the mixture except the catalyst through the catalyst recycling device, and recycle the separated catalyst to the subsequent nitrification reaction process.

[0060] In a nitration process system where the catalyst is recycled, when recovering the catalyst, heating is usually required to remove or separate other components blended with the catalyst. This heat will be carried into the nitration reaction system together with the catalyst, affecting the nitration reaction. Therefore, in a nitration process system where a catalyst needs to be added, the reaction temperature during the nitration reaction process is usually determined by the temperature of the catalyst and the exotherm of the nitration reaction itself. If the reaction temperature is too high, it is usually very difficult to cool down in a timely and accurate manner from the outside through the reactor, easily leading to the generation of a large amount of by-products.

[0061] Therefore, in a nitration process system where the catalyst is recycled, the reaction temperature of the nitration reaction is usually controlled by adjusting the recovery temperature of the catalyst. However, when adjusting the recovery temperature of the catalyst, the concentration of the catalyst will also change accordingly, and the concentration of the catalyst can also easily lead to the generation of by-products. It can be seen that in the entire nitration process system, various process parameters are coupled with each other, and it is often very difficult to take into account the coupling effect between multiple reaction conditions in the manual adjustment method, and only multiple debugging and observations can be carried out. This not only highly depends on the experience and ability of the operator, but also during the process of multiple debugging and observations, the entire system remains in an inappropriate state for a relatively long period of time, and during this period, the by-products will increase significantly.

[0062] Based on this, this embodiment provides a method for automatic monitoring and automatic online control of the nitration process, which can control the nitration reaction temperature and the catalyst concentration within the target range by adjusting the recovery temperature and recovery pressure of the catalyst, thereby reducing reaction by-products, improving the stability and safety of the nitration reaction, and reducing the operation intensity of personnel.

[0063] In an exemplary embodiment, as Figure 1 shown, a nitration process control method is provided. In this embodiment, this method is exemplified by being applied to a terminal. Among them, the terminal can be, but is not limited to, various personal computers, laptop computers, smart phones, tablet computers, Internet of Things devices, and portable wearable devices. The Internet of Things devices can be smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, projection devices, etc. The portable wearable devices can be smart watches, smart bracelets, head-mounted devices, etc. The head-mounted device can be a virtual reality (VR) device, an augmented reality (AR) device, smart glasses, etc. It can be understood that this method can also be applied to a server, and can also be applied to a system including a terminal and a server, and is implemented through the interaction between the terminal and the server. In this embodiment, this method includes the following steps S10 - S30. Among them:

[0064] Step S10, when it is detected that the reaction temperature value in the nitration reaction process exceeds the preset reaction temperature target range, obtain the recovery temperature setting value and the recovery pressure setting value in the catalyst recovery process.

[0065] Among them, the nitration process includes a nitration reaction process and a catalyst recovery process. The catalyst recovered in the catalyst recovery process can be recycled and applied to the nitration reaction process.

[0066] The nitration reaction may refer to the process of introducing a nitro group into an organic compound molecule. The nitration reaction is usually achieved by substituting a nitro group for a hydrogen atom or other functional group in the organic compound, and it is an important method for synthesizing nitro compounds.

[0067] In some feasible embodiments, the nitration reaction may refer to an aromatic nitration reaction, and the aromatic nitration reaction may refer to the process of introducing a nitro group into an aromatic compound.

[0068] The aromatic nitration reaction usually requires a catalyst, especially when nitric acid is used as the nitration reagent. The catalyst can effectively promote the formation of the nitronium ion, which is a key intermediate for the nitration reaction of aromatic compounds. The catalyst may include at least one of sulfuric acid, phosphoric acid, ionic liquid, etc. After the nitration reaction, the nitro compound can be separated from the reaction mixture. The mixture after separating the nitro compound contains a catalyst, water, by-products, and impurity components, etc. After removing at least part of the water, by-products, and impurity components, etc., a certain concentration of the catalyst can be obtained and recycled in the aromatic nitration reaction.

[0069] The reaction temperature of the nitration reaction is one of the important factors affecting the by-products of the nitration reaction. If the reaction temperature is too low, the nitration reaction rate is slow and the reaction is incomplete. However, if the reaction temperature is too high, side reactions or substrate decomposition are likely to occur. A large amount of heat is usually released during the nitration reaction process, and heating is usually required during catalyst recovery. The catalyst will bring this part of the heat into the nitration reaction. In this way, it is easy to cause the reaction temperature to be too high, resulting in an increase in by-products. Therefore, an appropriate reaction temperature target range can be determined in advance based on actual situations or test results, etc., to guide the control process of the nitration process. For example, assuming that the reaction temperature target range is T1 - T2, where T2 is greater than T1, a temperature monitoring point can be set during the nitration reaction process, and a temperature sensor can be set. If it is detected that the actual reaction temperature of the nitration reaction is higher than T2 or lower than T1, the actual temperature of the nitration reaction can be adjusted back to the range of T1 - T2 by adjusting at least one process parameter in the nitration reaction process and the catalyst recovery process.

[0070] The reaction temperature value can be used to characterize the reaction temperature of the nitration reaction at the current moment or within a certain period of time in the future. That is to say, the reaction temperature value can include at least one of the measured reaction temperature value and the predicted reaction temperature value. The measured reaction temperature value can be obtained by collecting through a temperature sensor. The predicted reaction temperature value can be inferred based on the measured reaction temperature value and a preset temperature-time model, where the temperature-time model can be constructed based on test data. For example, the temperature at different times during the nitration reaction can be detected, and a correlation model between temperature and time can be constructed based on the detection results.

[0071] The set value of the recovery temperature can refer to the temperature condition set during the catalyst recovery process. The set value of the recovery pressure can refer to the pressure condition set during the catalyst recovery process.

[0072] In some feasible embodiments, the methods for catalyst recovery can include at least one of flash evaporation, extraction, crystallization, distillation, etc. Among them, the flash evaporation recovery method can separate sulfuric acid from volatile components within an extremely short time, so it is more suitable for the nitration process system for catalyst recycling applications.

[0073] Flash evaporation can refer to the process of realizing catalyst recovery by rapidly reducing the pressure to cause the volatile components in the reaction mixture to evaporate quickly. That is to say, before flash evaporation, the mixture after separating the nitro compound can be heated to a certain flash evaporation temperature under high pressure, and the flash evaporation temperature should be lower than the boiling point of the catalyst; then flash evaporation is carried out, that is, the pressure is rapidly reduced to the flash evaporation pressure, so that other components in the mixture except the catalyst evaporate quickly and are separated from the liquid phase, while the catalyst remains in the liquid phase and is recycled for use in the nitration reaction process.

[0074] Flash evaporation for catalyst recovery has the advantages of high efficiency, simple operation, environmental protection, etc. Therefore, for catalysts with relatively high boiling points, such as sulfuric acid, phosphoric acid, etc., the flash evaporation method can be used for catalyst recovery.

[0075] In the case of using the flash evaporation method for catalyst recovery, the recovery temperature can refer to the flash evaporation temperature, and the flash evaporation temperature can refer to the temperature that the mixture needs to reach before pressure reduction. The recovery pressure can refer to the flash evaporation pressure, and the flash evaporation pressure can refer to the pressure of the flash evaporation operation. It can be understood that flash evaporation is achieved by rapidly reducing the pressure, so that the volatile components in the mixture evaporate and separate quickly. Therefore, the flash evaporation pressure is lower than the pressure of the mixture before flash evaporation.

[0076] Exemplarily, in the process of synthesizing nitro compounds through a nitrification process, the reaction temperature value of the nitrification reaction process can be detected in real time, at regular intervals, or in a triggered manner, and the detected reaction temperature value is compared with a preset reaction temperature target range, and it is determined whether the detected reaction temperature value is within the preset reaction temperature target range. If it is determined that the reaction temperature value is within the preset reaction temperature target range, it indicates that the current reaction temperature value in the nitrification reaction process does not exceed the preset reaction temperature target range, and the existing process parameters can be maintained without adjustment, and the reaction temperature value in the nitrification reaction process can also be continuously monitored. If it is determined that the reaction temperature value is not within the preset reaction temperature target range, it indicates that the current reaction temperature value in the nitrification reaction process exceeds the preset reaction temperature target range, and temperature control is required. Therefore, the current set recovery temperature setting value and recovery pressure setting value in the catalyst recovery process can be obtained first.

[0077] Step S20, according to the reaction temperature value and the preset reaction temperature target range, adjust the recovery temperature setting value so that the reaction temperature value changes in a direction closer to the preset reaction temperature target range.

[0078] Among them, in the nitrification process where the catalyst is recycled, the heat generated during the heating of the catalyst during recovery will be brought into the nitrification reaction, thereby affecting the reaction temperature value. That is, there is a dynamic response relationship between the reaction temperature value in the nitrification reaction process and the recovery temperature setting value in the catalyst recovery process. Therefore, this dynamic response relationship can be captured in advance and applied to the nitrification process control method, and by adjusting the recovery temperature setting value, the dynamic regulation of the reaction temperature value can be achieved.

[0079] As an example, after obtaining the recovery temperature setting value, based on a preset temperature deviation calculation method, calculate the reaction temperature deviation value between the reaction temperature value and the reaction temperature target range, and then according to the dynamic response relationship between the preset reaction temperature deviation value and the recovery temperature adjustment value, determine the target recovery temperature adjustment value corresponding to the reaction temperature deviation value, and adjust the currently set recovery temperature setting value based on the target recovery temperature adjustment value. For example, if the reaction temperature deviation value is ΔT1 and the determined target recovery temperature adjustment value is ΔT2, if ΔT2 is greater than 0, the currently set recovery temperature setting value can be increased by ΔT2, and if ΔT2 is less than 0, the currently set recovery temperature setting value can be decreased by ΔT2.

[0080] As another example, after obtaining the recovery temperature setting value, based on the dynamic response relationship between the preset reaction temperature value and the recovery temperature value, determine the target recovery temperature setting value corresponding to the current reaction temperature value, and then the recovery temperature setting value can be adjusted to the target recovery temperature setting value.

[0081] Step S30: Adjust the set value of the recovery pressure according to the adjusted set value of the recovery temperature and the preset target range of the catalyst concentration, so that the catalyst concentration value during the catalyst recovery process changes in the direction closer to the preset target range of the catalyst concentration.

[0082] Among them, the recovery temperature during the catalyst recovery process may also affect the catalyst concentration. If the recovery temperature of the catalyst is relatively low, the recovered catalyst concentration may decrease accordingly. If the catalyst concentration is too low, it will not only significantly reduce the nitrification reaction rate and conversion rate, but also make the selectivity of the nitrification reaction poor and the side reactions increase, resulting in an increase in by-products. If the catalyst concentration is too high, it will intensify the severity of the nitrification reaction, cause the heat release of the nitrification reaction to intensify, and result in the loss of control of the reaction temperature during the nitrification reaction process. It will not only easily lead to the occurrence of polynitration reactions, reduce the selectivity of the target product, and generate more by-products, but may also trigger safety accidents. Therefore, an appropriate target range of the catalyst concentration can also be determined in advance based on the actual situation or test results, etc., to guide the control process of the nitrification process. For example, assuming that the target range of the catalyst concentration is C1 - C2, where C2 is greater than C1, a concentration monitoring point can be set during the catalyst recovery process. If the actual concentration of the catalyst is detected to be higher than C2 or lower than C1, the actual concentration of the catalyst can be adjusted back to the range of C1 - C2 by adjusting at least one process parameter during the catalyst recovery process.

[0083] During the catalyst recovery process, there is a dynamic response relationship between the catalyst concentration value and the set value of the recovery pressure during the catalyst recovery process. Therefore, this dynamic response relationship can be captured in advance and applied to the nitrification process control method to achieve dynamic control of the catalyst concentration value by regulating the set value of the recovery pressure.

[0084] In some feasible embodiments, the catalyst recovery process is a pressurized recovery process, that is, by increasing the pressure in the catalytic recovery device to increase the recovered catalyst concentration. In this case, the catalyst concentration value is positively correlated with the set value of the recovery pressure during the catalyst recovery process.

[0085] In other feasible embodiments, the catalyst recovery process is a depressurized recovery process, such as the catalyst recovery method of flash evaporation, that is, by reducing the pressure in the catalytic recovery device, the non-catalyst components are evaporated and removed from the liquid, thereby increasing the recovered catalyst concentration. In this case, the catalyst concentration value is negatively correlated with the set value of the recovery pressure during the catalyst recovery process.

[0086] The updated set value of the recovery temperature and the set value of the recovery pressure are mainly to make the reaction temperature value change in the direction closer to the preset target range of the reaction temperature, and the catalyst concentration value during the catalyst recovery process changes in the direction closer to the preset target range of the catalyst concentration.

[0087] In some feasible embodiments, the updated recovery temperature set value and the recovery pressure set value can make the reaction temperature value within the preset reaction temperature target range, and the catalyst concentration value during the catalyst recovery process within the preset catalyst concentration target range.

[0088] Exemplarily, after the recovery temperature set value is updated, based on the updated recovery temperature set value, the currently actually set recovery pressure set value, and the preset recovery concentration relationship model, the catalyst concentration value after the update of the recovery temperature set value can be calculated. Then, the catalyst concentration value after the update of the recovery temperature set value can be compared with the preset catalyst concentration target range to determine whether the catalyst concentration value will exceed the range after the update of the recovery temperature set value. If it is determined that the catalyst concentration value will exceed the range after the update of the recovery temperature set value, the recovery pressure set value can be adjusted according to the dynamic response relationship between the preset catalyst concentration value and the recovery pressure set value and the catalyst concentration value after the update of the recovery temperature set value. If it is determined that the catalyst concentration value will not exceed the range after the update of the recovery temperature set value, the current recovery pressure set value can be kept unchanged.

[0089] As an example, the method of adjusting the recovery pressure set value according to the dynamic response relationship between the preset catalyst concentration value and the recovery pressure set value and the catalyst concentration value after the update of the recovery temperature set value may include: calculating the catalyst concentration deviation value according to the catalyst concentration value after the update of the recovery temperature set value, the preset catalyst concentration target range, and the preset concentration deviation algorithm, and then determining the target recovery pressure adjustment value corresponding to the catalyst concentration deviation value according to the dynamic response relationship between the preset catalyst concentration value and the recovery pressure set value, and adjusting the currently set recovery pressure set value based on the target recovery pressure adjustment value. For example, if the reaction pressure deviation value is ΔP1 and the determined target recovery pressure adjustment value is ΔP2, if ΔP2 is greater than 0, the currently set recovery pressure set value can be increased by ΔP2, and if ΔP2 is less than 0, the currently set recovery temperature set value can be decreased by ΔP2.

[0090] As another example, after the recovery pressure set value is obtained, based on the dynamic response relationship between the preset catalyst concentration value and the recovery pressure set value, the target recovery pressure set value corresponding to the current catalyst concentration value can be determined, and then the recovery pressure set value can be adjusted to the target recovery pressure set value.

[0091] Among them, the catalyst concentration value can be used to characterize the catalyst concentration at the current moment or within a certain period of time in the future during the catalyst recovery process. That is to say, the catalyst concentration value can include at least one of the measured catalyst concentration value and the predicted catalyst concentration value. The measured catalyst concentration value can be obtained by detecting the recovered catalyst concentration. The predicted catalyst concentration value can be calculated based on the set value of the recovery pressure and the set value of the recovery temperature.

[0092] The above nitration process control method is applied to a nitration process with a catalyst recovery process. In this case, the nitration process includes a nitration reaction process and a catalyst recovery process, and the catalyst recovered in the catalyst recovery process is recycled to the nitration reaction process. By obtaining the set value of the recovery temperature and the set value of the recovery pressure in the catalyst recovery process when it is detected that the reaction temperature value in the nitration reaction process exceeds the preset reaction temperature target range, and adjusting the set value of the recovery temperature according to the reaction temperature value and the preset reaction temperature target range, so that the reaction temperature value changes in the direction of approaching the preset reaction temperature target range, the adjustment of the set value of the recovery temperature in the catalyst recovery process is realized when the reaction temperature value in the nitration reaction process exceeds the range, so as to achieve the purpose of controlling the reaction temperature value in the nitration reaction process. However, the adjustment of the set value of the recovery temperature in the catalyst recovery process will affect the recovered catalyst concentration. Therefore, further adjust the set value of the recovery pressure according to the adjusted set value of the recovery temperature and the preset catalyst concentration target range, so that the catalyst concentration value in the catalyst recovery process changes in the direction of approaching the preset catalyst concentration target range. By synchronously adjusting the set value of the recovery pressure in the catalyst recovery process, effective control of the catalyst concentration can be achieved. Compared with the way that the operator manually controls the reaction conditions according to experience, the present application can more accurately and efficiently capture the abnormality of the nitration process by automatically monitoring the reaction temperature in the nitration reaction process, and in response to this abnormality, adaptively adjust the set value of the recovery temperature and the set value of the recovery pressure in the catalyst recovery process, fully considering the mutual coupling effects of the nitration reaction temperature, the catalyst recovery temperature, the catalyst recovery pressure and the catalyst concentration, can realize the synchronous coordinated control of the reaction temperature in the nitration reaction process and the catalyst concentration in the catalyst recovery process, can more accurately and timely eliminate the reaction temperature abnormality, and can effectively predict and prevent the deviation of the catalyst concentration, effectively reduce the by-products generated due to the reaction temperature abnormality and the deviation of the catalyst concentration, and improve the stability of the nitration reaction.

[0093] In an exemplary embodiment, adjusting the set value of the recovery temperature according to the reaction temperature value and the preset reaction temperature target range includes: steps S21 to S22. Among them:

[0094] Step S21: Detect the reaction temperature deviation value based on the reaction temperature value and the preset reaction temperature target range.

[0095] Among them, the reaction temperature deviation value can be used to characterize the deviation between the reaction temperature value and the reaction temperature target range. For example, the minimum difference between the reaction temperature value and the reaction temperature target range can be used as the reaction temperature deviation value, or the minimum ratio between the reaction temperature value and the reaction temperature target range can also be used as the reaction temperature deviation value.

[0096] Exemplarily, after each detection of the reaction temperature value, the reaction temperature deviation value between the reaction temperature value and the reaction temperature target range can be calculated based on a preset temperature deviation calculation method.

[0097] Step S22: Adjust the recovery temperature setting value based on the reaction temperature deviation value and the preset temperature transfer function.

[0098] Among them, the temperature transfer function can refer to a mathematical model used to describe the relationship between the catalyst temperature value and the reaction temperature value during the nitrification reaction process, and is used to characterize the dynamic response relationship between the temperature adjustment value during the catalytic recovery process and the reaction temperature deviation value during the nitrification reaction process. Among them, during the catalytic recovery process, the mixture containing the catalyst is heated to the recovery temperature setting value. After separating the catalyst, the catalyst still maintains the recovery temperature setting value and participates in the nitrification reaction at the temperature of the recovery temperature setting value. Therefore, the catalyst temperature value during the nitrification reaction process is determined by the recovery temperature setting value during the catalytic recovery process.

[0099] The temperature transfer function can be determined by fitting based on historical operation data and historical monitoring data in advance. Specifically, before actually controlling the nitrification process, first obtain the historical operation data and historical detection data of the nitrification process. The historical operation data includes the historical recovery temperature adjustment value, and the historical detection data includes the historical reaction temperature deviation value. The historical recovery temperature adjustment value and the historical reaction temperature deviation value correspond one by one. That is, after each update of the historical recovery temperature setting value, first calculate the difference or ratio of the historical recovery temperature setting value before and after the update, determine the difference or ratio as the historical recovery temperature adjustment value, and detect the historical reaction temperature value of the nitrification reaction before and after the update of the historical recovery temperature setting value, so as to calculate the corresponding historical reaction temperature deviation value; furthermore, the temperature transfer function can be fitted based on the historical recovery temperature adjustment value and the historical reaction temperature deviation value.

[0100] Exemplarily, after determining the reaction temperature deviation value, the reaction temperature deviation value can be substituted into the preset temperature transfer function to calculate the target temperature adjustment value, and then the target temperature adjustment value is aggregated with the currently set recovery temperature setting value.

[0101] It can be understood that the way the target temperature adjustment value is aggregated with the currently set recovery temperature setting value is determined based on the calculation method of the deviation value. For example, if the deviation value is obtained by taking the difference, the aggregation can be summation; if the deviation value is obtained by division, the aggregation can be multiplication. Specifically, it can be determined according to the actual situation, and this embodiment does not limit it.

[0102] In this embodiment, through the temperature transfer function, the conversion between the reaction temperature in the nitrification reaction process and the recovery temperature in the catalytic recovery process can be realized. Thus, by adjusting the recovery temperature in the catalytic recovery process, the precise control of the reaction temperature in the nitrification reaction process can be achieved.

[0103] In an exemplary embodiment, based on the reaction temperature deviation value and the preset temperature transfer function, adjusting the recovery temperature setting value includes steps S221 to S225. Among them:

[0104] Step S221, based on the reaction temperature deviation value and the preset temperature transfer function, detect the target temperature adjustment value of the catalyst recovery process.

[0105] Step S222, determine the sum of the recovery temperature setting value and the target temperature adjustment value as the initial temperature update value.

[0106] It should be noted that in the catalyst recovery process, it is often necessary to heat the mixture containing the catalyst to separate other components in the mixture from the catalyst, so as to obtain a catalyst with higher purity and recycle it in the nitrification reaction process.

[0107] However, if the catalyst recovery temperature is too high, although the evaporation rate of volatile components increases and the separation efficiency improves, the catalyst may also decompose. If the catalyst recovery temperature is too low, the evaporation rate of volatile components slows down and the separation efficiency decreases. When the catalyst needs to be recycled, there are still a large number of impurity components left in the mixture, resulting in a low catalyst concentration and purity, poor catalytic effect, and increased by-products.

[0108] Therefore, an appropriate temperature adjustment range can be determined in advance based on the actual situation or test results, etc., to limit the temperature control in the catalytic recovery process.

[0109] Exemplarily, after determining the reaction temperature deviation value, the reaction temperature deviation value can be brought into the preset temperature transfer function to calculate the target temperature adjustment value. Then, the target temperature adjustment value is added to the currently set recovery temperature setting value, and the sum of the two is determined as the initial temperature update value.

[0110] Step S223, when the initial temperature update value is within the preset temperature adjustment range, set the initial temperature update value as the new recovery temperature set value.

[0111] Exemplarily, after adding the target temperature adjustment value to the currently set recovery temperature set value to obtain the initial temperature update value, it can be first determined whether the initial temperature update value is within the preset temperature adjustment range. If the initial temperature update value is within the preset temperature adjustment range, the initial temperature update value can be set as the new recovery temperature set value during the catalytic recovery process.

[0112] Step S224, when the initial temperature update value is higher than the upper limit value of the preset temperature adjustment range, set the upper limit value of the preset temperature adjustment range as the new recovery temperature set value.

[0113] Exemplarily, if the initial temperature update value is higher than the upper limit value of the preset temperature adjustment range, it indicates that the initial temperature update value is too high, which may lead to an increase in by-products, but also indicates that the reaction temperature during the nitration reaction process is too low and needs to be heated up as soon as possible. Therefore, the upper limit value of the preset temperature adjustment range can be set as the new recovery temperature set value during the catalytic recovery process to maximize the nitration reaction temperature while ensuring the quality of the nitration reaction.

[0114] Step S225, when the initial temperature update value is lower than the lower limit value of the preset temperature adjustment range, set the lower limit value of the preset temperature adjustment range as the new recovery temperature set value.

[0115] Exemplarily, if the initial temperature update value is lower than the lower limit value of the preset temperature adjustment range, it indicates that the initial temperature update value is too low, which may lead to too low a concentration of the recycled catalyst and also an increase in by-products, but also indicates that the reaction temperature during the nitration reaction process is too high and needs to be cooled down as soon as possible. Therefore, the lower limit value of the preset temperature adjustment range can be set as the new recovery temperature set value during the catalytic recovery process to maximize the reduction of the nitration reaction temperature while ensuring the quality of the nitration reaction.

[0116] In this embodiment, by setting the temperature adjustment range, the quality of the nitration reaction can be effectively ensured, and the situation where the temperature during the catalytic recovery process is too high or too low, resulting in the quality of the recovered catalyst being lower than expected and thus an increase in by-products, can be avoided. At the same time, when the initial temperature update value exceeds the preset temperature adjustment range, by setting the upper limit value or the lower limit value of the preset temperature adjustment range as the new recovery temperature set value, the nitration reaction temperature can be adjusted maximally.

[0117] In an exemplary embodiment, such as Figure 2As shown, according to the adjusted recovery temperature set value and the preset catalyst concentration target range, the recovery pressure set value is adjusted, including steps S31 to S33. Among them:

[0118] Step S31, according to the new recovery temperature set value and the recovery pressure set value, detect the initial catalyst concentration value.

[0119] Among them, the initial catalyst concentration value can refer to the estimated concentration value of the catalyst recovered under the condition of catalyst recovery based on the updated recovery temperature set value and the unupdated recovery pressure set value. By calculating the initial catalyst concentration value, it can be predicted in advance whether the update of the recovery temperature set value will cause the catalyst concentration to deviate from the catalyst concentration target range. If it is predicted that the update of the recovery temperature set value will cause the catalyst concentration to deviate from the catalyst concentration target range, it indicates that the catalyst concentration needs to be regulated to avoid the increase of by-products caused by the deviation of the catalyst concentration from the catalyst concentration target range.

[0120] Exemplarily, a concentration relationship model among the recovery temperature set value, the recovery pressure set value, and the catalyst concentration value can be constructed in advance based on historical data, test results, etc. During the actual nitrification process control, when the recovery temperature set value is updated, the updated recovery temperature set value and the unupdated recovery pressure set value can be brought into the pre-constructed concentration relationship model to calculate the initial catalyst concentration value.

[0121] In some feasible implementation manners, the catalyst recovery method can be flash evaporation. The recovery temperature can refer to the flash evaporation temperature, and the flash evaporation temperature can refer to the temperature that the mixture needs to reach before pressure reduction. The recovery pressure can refer to the flash evaporation pressure, and the flash evaporation pressure can refer to the pressure of the flash evaporation operation. It can be understood that flash evaporation is to quickly separate the volatile components in the mixture by rapidly reducing the pressure. Therefore, the flash evaporation pressure is lower than the pressure of the mixture before flash evaporation. The concentration relationship model can be expressed as:

[0122] AI.PV = T.PV×a + P.PV×b + c;

[0123] Among them, AI.PV can be the catalyst concentration value, T.PV can be the recovery temperature set value, P.PV can be the recovery pressure set value, and a, b, and c are all constants and can be determined by fitting.

[0124] In some feasible implementation manners, when the catalyst recovery method is flash evaporation, a is greater than 0, and b is less than 0, that is, the catalyst concentration value is positively correlated with the recovery temperature set value and negatively correlated with the recovery pressure set value.

[0125] As an example, before actually performing nitrification process control, historical operation data and historical detection data of the nitrification process can be obtained first. The historical operation data includes historical values of the recovery temperature and the recovery pressure, and the historical detection data includes the historical value of the catalyst concentration. The historical value of the recovery temperature, the historical value of the recovery pressure, and the historical value of the catalyst concentration correspond to each other one by one. Furthermore, based on the historical value of the recovery temperature, the historical value of the recovery pressure, and the historical value of the catalyst concentration, the above concentration relationship model can be fitted to determine the specific values of a, b, and c. During the actual nitrification process control, the fitted concentration relationship model can be directly applied. By substituting the updated recovery temperature set value and the unupdated recovery pressure set value into the concentration relationship model, the initial catalyst concentration value can be calculated.

[0126] Step S32, in the case where the initial catalyst concentration value exceeds the preset catalyst concentration target range, based on the initial catalyst concentration value and the preset catalyst concentration target range, detect the catalyst concentration deviation value.

[0127] Among them, the catalyst concentration deviation value can be used to characterize the deviation between the catalyst concentration value and the catalyst concentration target range. For example, the minimum difference between the catalyst concentration value and the catalyst concentration target range can be used as the catalyst concentration deviation value, or alternatively, the minimum ratio between the catalyst concentration value and the catalyst concentration target range can be used as the catalyst concentration deviation value.

[0128] Exemplarily, after determining the initial catalyst concentration value, the catalyst concentration deviation value can be calculated according to the initial catalyst concentration value, the preset catalyst concentration target range, and the preset concentration deviation algorithm. Among them, the preset concentration deviation algorithm can be determined according to the actual situation and test results, etc., and this embodiment does not limit this.

[0129] Step S33, based on the catalyst concentration deviation value and the preset pressure transfer function, adjust the recovery pressure set value.

[0130] Among them, the pressure transfer function can refer to a mathematical model used to describe the relationship between the catalyst concentration value and the recovery pressure value during the catalyst recovery process, and is used to characterize the dynamic response relationship between the catalyst concentration deviation value and the pressure adjustment value during the catalyst recovery process.

[0131] The pressure transfer function can be pre-determined by fitting based on historical operation data and historical monitoring data. Specifically, before actually controlling the nitrification process, the historical operation data and historical detection data of the nitrification process can be obtained first. The historical operation data includes the historical recycle pressure adjustment value, and the historical detection data includes the historical catalyst concentration change value. The historical recycle pressure adjustment value corresponds one-to-one with the historical catalyst concentration change value. That is, after each update of the historical recycle pressure set value, first calculate the difference or ratio of the historical recycle pressure set value before and after the update, determine the difference or ratio as the historical recycle pressure adjustment value, and detect the historical catalyst concentration value of the recovered catalyst before and after the update of the historical recycle pressure set value, so as to calculate the corresponding historical catalyst concentration change value. Furthermore, the pressure transfer function can be fitted based on the historical recycle pressure adjustment value and the historical catalyst concentration change value.

[0132] Exemplarily, after calculating the catalyst concentration deviation value, it can be determined whether the catalyst concentration value exceeds the range after the update of the recycle temperature set value based on the catalyst concentration deviation value. If it is determined that the catalyst concentration value exceeds the range after the update of the recycle temperature set value, the catalyst concentration deviation value can be substituted into the preset pressure transfer function to calculate the recycle pressure adjustment value, and then the recycle pressure adjustment value and the recycle pressure set value are aggregated to obtain a new recycle pressure set value. If it is determined that the catalyst concentration will not exceed the range after the update of the recycle temperature set value, the current recycle pressure set value can be kept unchanged.

[0133] It can be understood that the way of aggregating the recycle pressure adjustment value and the currently set recycle pressure set value is determined based on the calculation method of the deviation value. For example, if the deviation value is obtained by subtraction, the aggregation can be addition; if the deviation value is obtained by division, the aggregation can be multiplication, which can be specifically determined according to the actual situation, and this embodiment does not limit this.

[0134] In this embodiment, considering that the catalyst concentration is related to both the recycle temperature and the recycle pressure, when the recycle temperature changes to meet the actual needs of the reaction temperature, by predicting the catalyst concentration after the update of the recycle temperature set value, the recycle pressure can be adjusted in time when it is predicted that the catalyst concentration will exceed the range, so as to ensure the effective control of the catalyst concentration. Thus, the synchronous coordinated control of the reaction temperature in the nitrification reaction process and the catalyst concentration in the catalyst recovery process is realized, the by-products generated due to abnormal reaction temperature and deviation of catalyst concentration are reduced, and the stability of the nitrification reaction is improved.

[0135] In an exemplary embodiment, based on the catalyst concentration deviation value and the preset pressure transfer function, adjusting the recycle pressure set value includes steps S331 to S335. Among them:

[0136] Step S331, detecting a target pressure adjustment value of a catalyst recovery process based on a catalyst concentration deviation value and a preset concentration transfer function;

[0137] Step S332: determine the sum of the recovery pressure setting value and the target pressure adjustment value as the initial pressure update value.

[0138] It should be noted that during the catalyst recovery process, it is often necessary to regulate the pressure of the mixture containing the catalyst so that other components in the mixture except the catalyst are separated from the catalyst, thereby obtaining a catalyst with higher purity for recycling in the reaction process.

[0139] In the case of pressurized catalyst recovery, if the catalyst recovery pressure is too high, although it may speed up the separation rate of certain volatile components, it may cause changes in the catalyst structure or damage to the active sites, thereby reducing the activity and stability of the catalyst; if the catalyst recovery pressure is too low, the evaporation rate of the volatile components slows down and the separation efficiency decreases. When the catalyst needs to be recycled, a large amount of impurity components still remain in the mixture, resulting in lower catalyst concentration and purity, poor catalytic effect, and an increase in by-products.

[0140] In the case where reduced pressure promotes catalyst recovery, for example, when the catalyst recovery method is flash evaporation, if the catalyst recovery pressure is too high, it may lead to incomplete separation of the catalyst and volatile components, and a large amount of impurities will still remain in the mixture, affecting the purity of the catalyst and subsequent catalytic effects; if the catalyst recovery pressure is too low, although rapid evaporation of volatile components can be achieved, the catalyst particles may be subjected to mechanical shock due to the sudden drop in pressure, and even structural damage or loss of active sites may occur, thereby reducing the activity and stability of the catalyst.

[0141] Therefore, an appropriate pressure adjustment range can be determined in advance based on actual conditions or test results, etc., to limit the pressure regulation during the catalytic recovery process.

[0142] Exemplarily, after determining the reaction pressure deviation value, the reaction pressure deviation value can be substituted into the preset concentration transfer function to calculate the target pressure adjustment value, and then the target pressure adjustment value is added to the currently set recovery pressure setting value, and the sum of the two is determined as the initial pressure update value.

[0143] Step S333: When the initial pressure update value is within the preset pressure adjustment range, the initial pressure update value is set as a new recovery pressure setting value.

[0144] Exemplarily, after adding the target pressure adjustment value to the currently set recovery pressure set value to obtain the initial pressure update value, it can first be determined whether the initial pressure update value is within the preset pressure adjustment range. If the initial pressure update value is within the preset pressure adjustment range, the initial pressure update value can be set as the new recovery pressure set value in the catalytic recovery process.

[0145] Step S334, in the case where the initial pressure update value is higher than the upper limit value of the preset pressure adjustment range, set the upper limit value of the preset pressure adjustment range as the new recovery pressure set value.

[0146] Exemplarily, if the initial pressure update value is higher than the upper limit value of the preset pressure adjustment range, it indicates that the initial pressure update value is too high, which may lead to an increase in by-products. However, it also indicates that after the recovery temperature set value is updated, the recovered catalyst concentration may be too high or too low, and the recovery pressure needs to be increased as soon as possible. Therefore, the upper limit value of the preset pressure adjustment range can be set as the new recovery pressure set value in the catalytic recovery process. While ensuring the quality of the nitration reaction, the nitration reaction pressure can be maximally increased, and the catalyst concentration can be quickly adjusted back to the preset catalyst concentration target range.

[0147] Step S335, in the case where the initial pressure update value is lower than the lower limit value of the preset pressure adjustment range, set the lower limit value of the preset pressure adjustment range as the new recovery pressure set value.

[0148] Exemplarily, if the initial pressure update value is lower than the lower limit value of the preset pressure adjustment range, it indicates that the initial pressure update value is too low, which may lead to an increase in by-products. However, it also indicates that after the recovery temperature set value is updated, the recovered catalyst concentration may be too high or too low, and the recovery pressure needs to be decreased as soon as possible. Therefore, the lower limit value of the preset pressure adjustment range can be set as the new recovery pressure set value in the catalytic recovery process. While ensuring the quality of the nitration reaction, the nitration reaction pressure can be maximally decreased, and the catalyst concentration can be quickly adjusted back to the preset catalyst concentration target range.

[0149] In this embodiment, by setting the pressure adjustment range, the quality of the nitration reaction can be effectively ensured, and the situation of the pressure in the catalytic recovery process being too high or too low, resulting in the quality of the recovered catalyst being lower than expected and thus an increase in by-products can be avoided. At the same time, in the case where the initial pressure update value exceeds the preset pressure adjustment range, by setting the upper limit value or the lower limit value of the preset pressure adjustment range as the new recovery pressure set value, the nitration reaction pressure can be maximally adjusted.

[0150] In an exemplary embodiment, the reaction temperature value includes a predicted reaction temperature value; before obtaining the set value of the recovery temperature and the set value of the recovery pressure in the catalyst recovery process when it is detected that the reaction temperature value in the nitration reaction process exceeds the preset reaction temperature target range, the method further includes steps S01 to S03. Wherein:

[0151] Step S01, obtaining the measured reaction temperature value of the nitration reaction process at the current time step.

[0152] It should be noted that adjusting the process parameters in the catalyst recovery process based on the reaction temperature at the current moment will actually act on the nitration reaction at a future moment, and what is achieved is the adjustment of the reaction temperature at a future moment. That is to say, there is a lag in the nitration process control relative to the nitration reaction process. However, during the nitration reaction process, as the reaction progresses, the reaction temperature will change, and the difference between the reaction temperature at a future moment and the reaction temperature at the current moment will result in the nitration process control effect being lower than expected.

[0153] Among them, the measured reaction temperature value can refer to the reaction temperature value at the current time step collected by a temperature sensor arranged in the reactor or the nitration reaction system. The terminal can be communicatively connected to the temperature sensor to obtain the measured reaction temperature value collected by the temperature sensor.

[0154] Exemplarily, the measured reaction temperature value of the nitration reaction process at the current time step can be collected in real time, regularly, or in a triggered manner by a temperature sensor arranged in the reactor or the nitration reaction system.

[0155] Step S02, detecting the predicted reaction temperature value of the nitration reaction process at the next time step based on the measured reaction temperature value and the temperature-time model corresponding to the nitration reaction process.

[0156] Among them, the temperature-time model can refer to a mathematical model used to describe the change of temperature with time during the nitration reaction process, which can be obtained by fitting in advance based on test data or historical data.

[0157] Time step is a concept used in numerical simulation and calculation, referring to the discretization of continuous time into a series of intervals or steps. Each time step represents the length of this interval, and within this interval, it is assumed that the state change of the system can be described or approximated in some way.

[0158] In some feasible embodiments, the step size of the time step can be determined based on the duration of nitrification process control. As an example, the time interval between the first moment when the measured reaction temperature value is collected and the second moment when the set recovery temperature value and the set recovery pressure value are completed can be monitored and recorded, and this time interval can be determined as the step size of the time step. It can be understood that it can be monitored and recorded multiple times to obtain multiple time intervals, and then the step size of the time step can be determined by calculating the average value, median value, etc.

[0159] Exemplarily, after determining the measured reaction temperature value, the measured reaction temperature value can be input into a pre-constructed temperature-time model to predict the predicted reaction temperature value at the next time step of the nitrification reaction process.

[0160] Step S03, detect whether the predicted reaction temperature value exceeds the preset reaction temperature target range.

[0161] Exemplarily, after predicting the predicted reaction temperature value at the next time step of the nitrification reaction process, the predicted reaction temperature value can be compared with the preset reaction temperature target range, and it can be judged whether the predicted reaction temperature value is within the preset reaction temperature target range.

[0162] If it is determined that the reaction temperature value is not within the preset reaction temperature target range, a new set recovery temperature value can be set based on the predicted reaction temperature value, the preset reaction temperature target range, and the set recovery temperature value.

[0163] In this embodiment, by predicting the predicted reaction temperature value at the next time step and controlling the nitrification process based on the predicted reaction temperature value, the process parameters can be adjusted in advance to reduce the hysteresis, thereby improving the control effect of the nitrification process.

[0164] In an exemplary embodiment, the nitrification process can refer to the process of preparing nitrobenzene by reacting nitric acid and benzene under the catalysis of sulfuric acid. The nitrification process system is as Figure 3 shown. After sulfuric acid and nitric acid are mixed, they are mixed with the raw material benzene, and nitrobenzene is prepared through three-stage nitrification reaction. A temperature sensor can be set between the first-stage reaction and the second-stage reaction to collect the first-stage outlet temperature, and the first-stage outlet temperature can be used as the measured reaction temperature value. Further, after the three-stage nitrification reaction is completed, the reaction mixture is stratified in a separator. The nitrobenzene generated by the nitrification reaction enters the organic phase, while the sulfuric acid as a catalyst, other water-soluble by-products and impurities, etc. will enter the aqueous phase. The organic phase and the aqueous phase are separated. The organic phase can be further extracted and purified to obtain the nitrobenzene product, while the aqueous phase can be further transferred to a sulfuric acid flash evaporator to recover sulfuric acid by flash evaporation, realizing the recycling of sulfuric acid. During the flash evaporation process, the volatile components in the aqueous phase are evaporated and can be condensed and collected by a condenser.

[0165] Using the above nitrification process system, when the operating load is 100%, the annual output of nitrobenzene is 240,000 tons. When the load is 100%, according to the operating data, it is found that the preset reaction temperature target range is controlled at 116°C - 117°C, and the preset catalyst concentration target range is controlled at 70.3% - 70.7%. There are fewer by-products in the nitrification reaction, and the device operates relatively stably.

[0166] According to the quality inspection data and the device operating data, the concentration relationship model among the set value of the recovery temperature, the set value of the recovery pressure, and the sulfuric acid concentration value is fitted as:

[0167] AI = 42.3 + 0.35×T - 0.88×P;

[0168] where, AI is the sulfuric acid concentration value; T is the set value of the recovery temperature; P is the set value of the recovery pressure.

[0169] According to the step test results, the temperature transfer function is fitted, and the temperature transfer function is expressed as:

[0170]

[0171] where, s represents the transfer function variable factor; T1(s) represents the reaction temperature deviation value, which can be calculated and determined based on the outlet temperature of a certain section; T2(s).SP(s) represents the target temperature adjustment value; the fitted = 1.83, = 17, = 16.78.

[0172] According to the step test results, the pressure transfer function is fitted, and the pressure transfer function is expressed as:

[0173]

[0174] where, s represents the transfer function variable factor; AI1(s) represents the catalyst concentration deviation value, which can be calculated and determined based on the adjusted set value of the recovery temperature and the set value of the recovery pressure; P1(s).SP(s) represents the target pressure adjustment value; = -1.16, = 47, = 16.79.

[0175] At the current 100% load, the temperature at the outlet of the first stage is 118.3°C, the concentration of the circulating sulfuric acid is 70.6%. There is a deviation between the temperature at the outlet of the first stage and the preset reaction temperature target range. The control method of this patent is used for automatic adjustment. The temperature at the outlet of the first stage is adjusted to 116.6°C, the concentration of the circulating sulfuric acid is adjusted to 70.7%, the temperature of the circulating sulfuric acid is adjusted from 101.2°C to 100.3°C. To ensure the stability of the concentration of the circulating sulfuric acid, the pressure of the circulating sulfuric acid is adjusted from 8.1 kPa to 8.3 kPa. Track the changes in the by-products of the nitration reaction before and after the adjustment. The by-product mononitrophenol is reduced from 161 ppm to 89 ppm, improving the reaction operation efficiency and safety.

[0176] It should be understood that although the steps in the flowcharts involved in the above embodiments are shown in sequence according to the arrows, these steps do not necessarily need to be executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages. These steps or stages do not necessarily need to be executed at the same moment, but can be executed at different moments. The execution order of these steps or stages does not necessarily need to be sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0177] Based on the same inventive concept, the embodiments of the present application also provide a nitration process control device for implementing the nitration process control method involved above. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the nitration process control device provided below can refer to the limitations on the nitration process control method in the above text, and will not be repeated here.

[0178] In an exemplary embodiment, as Figure 4 shown, a nitration process control device is provided. The nitration process includes a nitration reaction process and a catalyst recovery process. The catalyst recovered in the catalyst recovery process is recycled and applied to the nitration reaction process. The device includes: an acquisition module 402, a first setting module 404, and a second setting module 406, where:

[0179] The acquisition module 402 is used to acquire the reaction temperature value of the nitration reaction process, as well as the recovery temperature setting value and the recovery pressure setting value of the catalyst recovery process;

[0180] The first setting module 404 is configured to, when the reaction temperature value exceeds the preset reaction temperature target range, adjust the recovery temperature setting value according to the reaction temperature value and the preset reaction temperature target range, so that the reaction temperature value changes in a direction closer to the preset reaction temperature target range;

[0181] The second setting module 406 is configured to adjust the recovery pressure setting value according to the adjusted recovery temperature setting value and the preset catalyst concentration target range, so that the catalyst concentration value during the catalyst recovery process changes in a direction closer to the preset catalyst concentration target range.

[0182] In an exemplary embodiment, the first setting module 404 is further configured to:

[0183] Detect the reaction temperature deviation value based on the reaction temperature value and the preset reaction temperature target range;

[0184] Adjust the recovery temperature setting value based on the reaction temperature deviation value and the preset temperature transfer function.

[0185] In an exemplary embodiment, the first setting module 404 is further configured to:

[0186] Detect the target temperature adjustment value for the catalyst recovery process based on the reaction temperature deviation value and the preset temperature transfer function;

[0187] Determine the sum of the recovery temperature setting value and the target temperature adjustment value as the initial temperature update value;

[0188] When the initial temperature update value is within the preset temperature adjustment range, set the initial temperature update value as the new recovery temperature setting value;

[0189] When the initial temperature update value is higher than the upper limit value of the preset temperature adjustment range, set the upper limit value of the preset temperature adjustment range as the new recovery temperature setting value;

[0190] When the initial temperature update value is lower than the lower limit value of the preset temperature adjustment range, set the lower limit value of the preset temperature adjustment range as the new recovery temperature setting value.

[0191] In an exemplary embodiment, the second setting module 406 is further configured to:

[0192] Detect the initial catalyst concentration value according to the new recovery temperature setting value and the recovery pressure setting value;

[0193] When the initial catalyst concentration value exceeds the preset catalyst concentration target range, detect the catalyst concentration deviation value based on the initial catalyst concentration value and the preset catalyst concentration target range;

[0194] Adjust the set value of the recovery pressure based on the catalyst concentration deviation value and the preset pressure transfer function.

[0195] In an exemplary embodiment, the second setting module 406 is further configured to:

[0196] Detect the target pressure adjustment value in the catalyst recovery process based on the catalyst concentration deviation value and the preset concentration transfer function;

[0197] Determine the sum of the set value of the recovery pressure and the target pressure adjustment value as the initial pressure update value;

[0198] When the initial pressure update value is within the preset pressure adjustment range, set the initial pressure update value as the new set value of the recovery pressure;

[0199] When the initial pressure update value is higher than the upper limit value of the preset pressure adjustment range, set the upper limit value of the preset pressure adjustment range as the new set value of the recovery pressure;

[0200] When the initial pressure update value is lower than the lower limit value of the preset pressure adjustment range, set the lower limit value of the preset pressure adjustment range as the new set value of the recovery pressure.

[0201] In an exemplary embodiment, the nitrification process control device further includes a prediction module; the reaction temperature value includes a predicted reaction temperature value; before obtaining the set value of the recovery temperature and the set value of the recovery pressure in the catalyst recovery process when it is detected that the reaction temperature value in the nitrification reaction process exceeds the preset reaction temperature target range, the prediction module is used to:

[0202] Obtain the measured value of the reaction temperature at the current time step in the nitrification reaction process;

[0203] Detect the predicted reaction temperature value at the next time step in the nitrification reaction process based on the measured value of the reaction temperature and the temperature-time model corresponding to the nitrification reaction process;

[0204] Detect whether the predicted reaction temperature value exceeds the preset reaction temperature target range.

[0205] Each module in the above nitrification process control device can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in the processor of the computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to the above modules.

[0206] In an exemplary embodiment, a computer device is provided. The computer device can be a terminal, and its internal structure diagram can be as Figure 5As shown in the figure. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit, and an input device. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface, the display unit, and the input device are connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, near field communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a nitrification process control method. The display unit of the computer device is used to form a visually visible picture, which can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer covering the display screen, or a button, a trackball, or a touchpad provided on the computer device housing, or an external keyboard, touchpad, or mouse, etc.

[0207] Those skilled in the art can understand that Figure 5 the structure shown in the figure is only a block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0208] In one embodiment, a computer device is further provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the steps in the above method embodiments are implemented.

[0209] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by the processor, the steps in the above method embodiments are implemented.

[0210] In one embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by the processor, the steps in the above method embodiments are implemented.

[0211] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0212] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., and are not limited thereto. The processors involved in the embodiments provided in this application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logic devices, data processing logics based on quantum computing, artificial intelligence (AI) processors, etc., and are not limited thereto.

[0213] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this application.

[0214] The above embodiments only express several implementation manners of this application, and the description is relatively specific and detailed. However, it should not be construed as a limitation on the patent scope of this application. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application should be subject to the appended claims.

Claims

1. A method for controlling a nitrification process, characterized in that, The nitrification process includes a nitrification reaction process and a catalyst recovery process. The catalyst recovered in the catalyst recovery process is recycled and applied to the nitrification reaction process. The method includes: When it is detected that the reaction temperature value in the nitrification reaction process exceeds the preset reaction temperature target range, obtain the recovery temperature set value and the recovery pressure set value in the catalyst recovery process; According to the reaction temperature value and the preset reaction temperature target range, adjust the recovery temperature set value so that the reaction temperature value changes in the direction of approaching the preset reaction temperature target range; According to the adjusted recovery temperature set value and the preset catalyst concentration target range, adjust the recovery pressure set value so that the catalyst concentration value in the catalyst recovery process changes in the direction of approaching the preset catalyst concentration target range.

2. The method according to claim 1, characterized in that, The adjusting the recovery temperature set value according to the reaction temperature value and the preset reaction temperature target range includes: Based on the reaction temperature value and the preset reaction temperature target range, detect the reaction temperature deviation value; Based on the reaction temperature deviation value and the preset temperature transfer function, adjust the recovery temperature set value.

3. The method according to claim 2, wherein The adjusting the recovery temperature set value based on the reaction temperature deviation value and the preset temperature transfer function includes: Based on the reaction temperature deviation value and the preset temperature transfer function, detect the target temperature adjustment value of the catalyst recovery process; Determine the sum of the recovery temperature set value and the target temperature adjustment value as the initial temperature update value; When the initial temperature update value is within the preset temperature adjustment range, set the initial temperature update value as the new recovery temperature set value; When the initial temperature update value is higher than the upper limit value of the preset temperature adjustment range, set the upper limit value of the preset temperature adjustment range as the new recovery temperature set value; When the initial temperature update value is lower than the lower limit value of the preset temperature adjustment range, set the lower limit value of the preset temperature adjustment range as the new recovery temperature set value.

4. The method according to claim 1, characterized in that, The adjusting the recovery pressure set value according to the adjusted recovery temperature set value and the preset catalyst concentration target range includes: According to the new recovery temperature set value and the recovery pressure set value, detect the initial catalyst concentration value; When the initial catalyst concentration value exceeds the preset catalyst concentration target range, based on the initial catalyst concentration value and the preset catalyst concentration target range, detect the catalyst concentration deviation value; Based on the catalyst concentration deviation value and the preset pressure transfer function, adjust the recovery pressure set value.

5. The method according to claim 4, wherein The adjusting the recovery pressure set value based on the catalyst concentration deviation value and the preset pressure transfer function includes: Based on the catalyst concentration deviation value and the preset concentration transfer function, detect the target pressure adjustment value of the catalyst recovery process; Determine the sum of the recovery pressure set value and the target pressure adjustment value as the initial pressure update value; When the initial pressure update value is within the preset pressure adjustment range, set the initial pressure update value as the new recovery pressure set value; In the case where the initial pressure update value is higher than the upper limit value of the preset pressure adjustment range, set the upper limit value of the preset pressure adjustment range as the new recovery pressure set value; In the case where the initial pressure update value is lower than the lower limit value of the preset pressure adjustment range, set the lower limit value of the preset pressure adjustment range as the new recovery pressure set value.

6. The method according to claim 1, characterized in that The reaction temperature value includes a predicted reaction temperature value; before obtaining the recovery temperature set value and the recovery pressure set value of the catalyst recovery process when it is detected that the reaction temperature value of the nitration reaction process exceeds the preset reaction temperature target range, the method further includes: Obtain the measured reaction temperature value of the nitration reaction process at the current time step; Based on the measured reaction temperature value and the temperature-time model corresponding to the nitration reaction process, detect the predicted reaction temperature value of the nitration reaction process at the next time step; Detect whether the predicted reaction temperature value exceeds the preset reaction temperature target range.

7. A nitrification process control device, characterized in that, The nitration process includes a nitration reaction process and a catalyst recovery process, and the catalyst recovered in the catalyst recovery process is recycled to the nitration reaction process. The device includes: An acquisition module for acquiring the reaction temperature value of the nitration reaction process, as well as the recovery temperature set value and the recovery pressure set value of the catalyst recovery process; A first setting module for adjusting the recovery temperature set value according to the reaction temperature value and the preset reaction temperature target range when the reaction temperature value exceeds the preset reaction temperature target range; A second setting module for adjusting the recovery pressure set value according to the adjusted recovery temperature set value and the preset catalyst concentration target range.

8. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product comprising a computer program, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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