A safety control method and system for the preparation of methyl ethyl carbonate

Abstract

This invention relates to a safety control method and system for the preparation of ethyl methyl carbonate (EMC). The method involves feeding dimethyl carbonate into an EMC purification tower, monitoring the pressure within the tower, and adjusting the pressure if it falls outside a preset range. The purity of the output dimethyl carbonate is also monitored. The output dimethyl carbonate, a sodium methoxide / methanol solution, and anhydrous ethanol are mixed in a specified ratio in a raw material mixing unit to achieve the required homogeneity. Pressure and temperature are monitored in an EMC reaction tower; if these requirements are not met, pressure or temperature is adjusted. The bottom liquid from the EMC reaction tower is transferred to a waste catalyst concentration tank for further processing, and then to an EMC light-weight removal tower for further treatment. Temperature and pressure are monitored within the EMC light-weight removal tower; if the pressure falls outside a preset range, pressure or temperature is adjusted. After cooling, the final EMC product is obtained. This process ensures safe and stable production of ethyl methyl carbonate.

Description

Technical Field

[0001] This invention belongs to the field of methyl ethyl carbonate production technology, and particularly relates to a safety control method and system in the preparation process of methyl ethyl carbonate. Background Technology

[0002] Ethyl methyl carbonate (EMC) is a colorless and transparent liquid with the molecular formula C4H8O3. It is insoluble in water and is mainly used as a solvent in organic synthesis and lithium-ion battery electrolytes. It can ignite and explode when exposed to high heat, open flame, or violent impact, and is classified as a flammable chemical.

[0003] In the production process of ethyl methyl carbonate (EMC), industrial-grade dimethyl carbonate is first pumped into an electronic-grade DMC purification tower for purification at 50-55°C and -0.06-0.08 MPa. Then, the purified dimethyl carbonate, sodium methoxide / methanol solution (catalyst), and anhydrous ethanol from the tank area are fed into the EMC reaction tower in appropriate proportions. Under specified pressure and temperature conditions, a transesterification reaction occurs, converting some dimethyl carbonate into ethyl methyl carbonate. Subsequent removal of light components and cooling treatment yields the final EMC product.

[0004] In the production of methyl ethyl carbonate (MEC), it is necessary to control the temperature and pressure within various production equipment, such as the dimethyl carbonate purification tower, EMC reaction tower, and EMC light-weight removal tower, to obtain dimethyl carbonate that meets purity requirements, ensure the reaction proceeds fully, or achieve complete light-weight removal. Simultaneously, it is crucial to prevent leaks in all production equipment during the MEC production process. Leaks of dimethyl carbonate, or other raw materials or finished products such as methyl ethyl carbonate, will pose serious safety hazards.

[0005] Therefore, how to implement safety control during the production and preparation of methyl ethyl carbonate and ensure the safe and stable operation of the entire production and preparation process is a technical problem that urgently needs to be solved. Summary of the Invention

[0006] The purpose of this invention is to provide a safety control method and system for the preparation of methyl ethyl carbonate, so as to carry out safety control in the production and preparation process of methyl ethyl carbonate and ensure that the entire production and preparation process of methyl ethyl carbonate is safe and stable.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0008] A safety control method for the preparation process of ethyl methyl carbonate includes the following steps:

[0009] S1: Industrial-grade dimethyl carbonate is fed into the dimethyl carbonate purification tower. The gas pressure inside the dimethyl carbonate purification tower is detected by the gas pressure detection unit. When the gas pressure detection value is not within the preset gas pressure range, the gas pressure inside the dimethyl carbonate purification tower is adjusted by the gas pressure adjustment unit until the gas pressure detection value is within the preset gas pressure range.

[0010] S2: After purification by the dimethyl carbonate purification tower, the purity of the output dimethyl carbonate is detected by the purity detection unit to determine whether the purity of the output dimethyl carbonate is within the preset purity range. If yes, proceed to step S3; otherwise, return the output dimethyl carbonate to the dimethyl carbonate purification tower for re-purification.

[0011] S3: Input the output dimethyl carbonate, catalyst sodium methoxide / methanol solution and anhydrous ethanol into the raw material mixing unit according to the specified ratio for mixing, and perform uniformity detection on the mixed raw material through the uniformity detection unit, and determine whether the uniformity detection result of the mixed raw material is within the preset uniformity range. If yes, proceed to step S4; otherwise, continue mixing the raw material until the uniformity detection result is within the preset uniformity range.

[0012] S4: Feed the uniform raw material into the EMC reaction tower, detect the gas pressure in the EMC reaction tower, and if the gas pressure in the EMC reaction tower is not within the preset gas pressure range, adjust the gas pressure through the gas pressure regulating unit. Detect the temperature in the EMC reaction tower through the temperature detection device, and if the temperature is not within the preset temperature range, adjust the temperature through the temperature regulating unit.

[0013] S6: The bottom liquid in the EMC reaction tower is transferred to the waste catalyst concentration tank for treatment to obtain liquid and gaseous substances. The liquid substances are dried and the gaseous substances are transferred to the EMC light-duty removal tower for further treatment.

[0014] S7: Detect the temperature and pressure inside the EMC light residue removal tower. If the pressure in the EMC reaction tower is not within the preset pressure range, adjust the pressure through the pressure regulating unit. If the temperature is not within the preset temperature range, adjust the temperature through the temperature regulating unit.

[0015] S8: The liquid in the bottom of the EMC light removal tower is sent into the EMC product tower and cooled by the cooler. The temperature inside the cooler is monitored. If the temperature of the cooler is not within the preset range, the temperature is adjusted by the temperature regulation unit. The cooled liquid is then transported into the EMC finished product tank to obtain the EMC finished product.

[0016] Preferably, during step S1, the temperature inside the dimethyl carbonate purification tower is detected by a temperature detection unit, and it is determined whether the temperature detection value is within the preset temperature range. If the temperature detection value is not within the preset temperature range, the temperature inside the dimethyl carbonate purification tower is adjusted by a temperature adjustment unit.

[0017] Preferably, it also includes a leak detection process, as follows:

[0018] Leak detection devices are installed at designated locations on each production equipment to detect leaks throughout the entire preparation process of dimethyl carbonate (DMCO). The devices emit ultraviolet light at these locations. When a leak occurs, the volatilized DMCO is excited by the ultraviolet light in the ionization chamber of the detection device. The excited DMCO molecules are ionized into positively and negatively charged particles. These charged particles collide with the electrode plates, generating a detectable weak current. This weak current is amplified by an amplifier circuit. The magnitude of the detected current is displayed on a display module, showing the corresponding degree and location of the leak. An early warning module then provides an alert.

[0019] Preferably, the amplification circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor, and a differential amplifier;

[0020] One end of the first resistor is connected to the positive terminal of the current output, and the other end is connected to the negative terminal of the current output. One end of the second resistor is connected to the first resistor, and the other end is connected to the inverting input terminal of the differential amplifier, the first capacitor, and the fourth resistor, respectively. The other end of the fourth resistor and the other end of the first capacitor are both grounded through the sixth resistor and connected to the output terminal of the amplified current.

[0021] One end of the third resistor is connected to the first resistor, and the other end is connected to the non-inverting input terminal of the differential amplifier and the fifth resistor, respectively. The positive terminal of the differential amplifier is connected to a 5V power supply, and the negative terminal is grounded.

[0022] Preferably, temperature and pressure prediction models are also deployed in each temperature and pressure regulation unit of the dimethyl carbonate purification tower, EMC reaction tower, and EMC light component removal tower. Historical datasets are constructed by acquiring historical purification time data and corresponding temperature and pressure data in the purification tower, historical EMC reaction time data and corresponding temperature and pressure data in the EMC reaction tower, and historical light component removal time data and corresponding temperature and pressure data in the EMC light component removal tower. The historical datasets are then labeled, and the labeled historical datasets are input into the temperature and pressure prediction models to train the models.

[0023] Preferably, in the dimethyl carbonate purification stage, the purification time data of the dimethyl carbonate purification tower is acquired through the data acquisition module, and the purification time data is input into the temperature and pressure prediction model. The temperature and pressure prediction model predicts the temperature and pressure corresponding to the purification time data, plots the relationship between temperature and pressure and purification time, and generates a relationship between temperature and pressure adjustment amount and purification time.

[0024] During the EMC reaction stage, the reaction time data of the EMC reaction tower is acquired through the data acquisition module. The reaction time data is input into the temperature and pressure prediction model. The temperature and pressure prediction model predicts the temperature and pressure corresponding to the reaction time data, plots the relationship between temperature and pressure and reaction time, and generates a relationship between temperature and pressure adjustment and reaction time.

[0025] During the EMC light-light removal stage, the light-light removal time data of the EMC light-light removal tower is acquired through the data acquisition module. The light-light removal time data is input into the temperature and pressure prediction model. The temperature and pressure prediction model predicts the temperature and pressure corresponding to the light-light removal time data, plots the relationship between temperature and pressure and light-light removal time, and generates a relationship between temperature and pressure adjustment and light-light removal time.

[0026] The temperature regulation unit and the pressure regulation unit directly obtain the temperature and pressure regulation amounts that change with time in each stage through the temperature and pressure regulation amount versus purification time graph, the temperature and pressure regulation amount versus reaction time graph, and the temperature and pressure regulation amount versus light removal time graph. Based on the temperature and pressure regulation amounts, they realize the advance adjustment of temperature and pressure so that the specified temperature and pressure can be reached at the corresponding time points.

[0027] Preferably, during the process of temperature and pressure regulation by the temperature regulation unit and the pressure regulation unit, the temperature detection unit and the pressure detection unit respectively detect the temperature and pressure of the corresponding equipment in real time, and judge whether the prediction result of the temperature and pressure prediction model is accurate based on the real-time detection result. If it is inaccurate, the inaccurate temperature or pressure and the corresponding time point are fed back to the temperature regulation unit and the pressure regulation unit to adjust the temperature and pressure regulation amount.

[0028] Preferably, the temperature and pressure prediction model is a neural network model, including an input layer, a hidden layer, and an output layer. The input layer has three channels, which are used to input temperature data, pressure data, and corresponding time data, respectively. The corresponding time data are purification time data, EMC reaction time data, and EMC light removal time data. The hidden layer has multiple layers, which are used to capture the relationship between the input temperature and pressure data and the corresponding time data. The output layer is used to output the predicted temperature and pressure data.

[0029] Preferably, the output calculation formula of the hidden layer is as follows:

[0030] Z k = f ( w k1 * X 1 +w k2 * X 2+···+ w ki * X i + w kn * X n );

[0031] in, Z k The output of the hidden layer, f It is a nonlinear function. w k1 The weights are the values ​​between the first node of the input layer and the kth node of the hidden layer. w k2 The weights are the values ​​between the second node in the input layer and the kth node in the hidden layer. w ki For the input layer i The weight between the node and the k-th node in the hidden layer w kn For the input layer n Nodes and Hidden Layers k Weights between nodes X 1 represents the input of the first node in the input layer. X 2 represents the input of the second node in the input layer. X i For the input layer i The input of the node, X n For the input layer n The input to the node.

[0032] Secondly, a safety control system is provided for the preparation process of methyl ethyl carbonate, used to implement the safety control method for the preparation process of methyl ethyl carbonate as described in any one of the claims, including a data acquisition module, a purity detection unit, a uniformity detection unit, a pressure regulation unit, a temperature regulation unit, and a temperature and pressure prediction model. The data acquisition module has multiple units respectively arranged in the dimethyl carbonate purification tower, the EMC reaction tower, and the EMC light-weight removal tower. The data acquisition module includes a pressure detection unit and a temperature detection unit. The purity detection unit is arranged at the output end of the dimethyl carbonate purification tower. The uniformity detection unit is arranged inside the raw material mixing unit. The pressure regulation unit and the temperature regulation unit are connected to the dimethyl carbonate purification tower, the EMC reaction tower, and the EMC light-weight removal tower. The temperature and pressure prediction model is connected to the data acquisition module, the pressure regulation unit, and the temperature regulation unit.

[0033] The data acquisition module is used to acquire various historical and real-time data from the dimethyl carbonate purification tower, EMC reaction tower, and EMC light component removal tower.

[0034] The uniformity detection unit is used to detect the uniformity of the raw materials in the raw material mixing unit;

[0035] The pressure regulating unit is used to regulate the pressure in the dimethyl carbonate purification tower, the EMC reaction tower and the EMC light component removal tower.

[0036] The temperature control unit is used to regulate the temperature inside the dimethyl carbonate purification tower, the EMC reaction tower, and the EMC light component removal tower.

[0037] The temperature and pressure prediction model is used to predict the temperature and pressure of the dimethyl carbonate purification tower, the EMC reaction tower, and the EMC light-light removal tower at corresponding times based on the purification time data of the dimethyl carbonate purification tower, the reaction time data of the EMC reaction tower, and the light-light removal time data of the EMC light-light removal tower.

[0038] The beneficial effects of this invention include:

[0039] The present invention provides a safety control method and system for the preparation process of ethyl methyl carbonate (EMC). The method involves feeding dimethyl carbonate into an EMC purification tower, monitoring the gas pressure within the tower, and adjusting the pressure if the pressure reading falls outside a preset range. The method also monitors the purity of the output dimethyl carbonate. The output dimethyl carbonate, catalyst sodium methoxide / methanol solution, and anhydrous ethanol are mixed in a specified ratio in a raw material mixing unit to achieve the required homogeneity. Pressure and temperature are monitored in the EMC reaction tower; if these requirements are not met, pressure or temperature is adjusted. The bottom liquid from the EMC reaction tower is transferred to a waste catalyst concentration tank for further processing, and then to an EMC light phase removal tower for further processing. Temperature and pressure are monitored within the EMC light phase removal tower; if the pressure falls outside a preset range, pressure or temperature is adjusted. After cooling, the final EMC product is obtained. This process ensures safe and stable production of ethyl methyl carbonate.

[0040] First, by installing leak detection devices at designated locations on each production equipment, leak detection is performed throughout the entire preparation process of dimethyl carbonate (DMC). The leak detection devices emit ultraviolet light at designated locations. When a leak of dimethyl carbonate or DMCC occurs, the volatilized dimethyl carbonate or DMCC is excited by ultraviolet light in the ionization chamber of the leak detection device. The excited dimethyl carbonate or DMCC molecules are ionized into particles with positive and negative charges. The charged particles collide with the electrode plate, forming a detectable weak current. This weak current is amplified by an amplification circuit, and the magnitude of the detected current is displayed to indicate the degree of leakage. This achieves rigorous leak monitoring, allowing for timely handling of leaks and ensuring leak safety throughout the entire production process.

[0041] Secondly, by incorporating an amplification circuit into the leakage detection device, including a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor, and a differential amplifier; one end of the first resistor is connected to the positive terminal of the current output, and the other end is connected to the negative terminal of the current output; one end of the second resistor is connected to the first resistor, and the other end is connected to the inverting input terminal of the differential amplifier, the first capacitor, and the fourth resistor, respectively; the other ends of the fourth resistor and the first capacitor are both grounded through the sixth resistor and connected to the output terminal of the amplified current; one end of the third resistor is connected to the first resistor, and the other end is connected to the non-inverting input terminal of the differential amplifier and the fifth resistor, respectively. This amplification of weak currents enables the detection of micro-leakages and avoids the situation where large-scale leaks are only discovered later, thus preventing significant safety hazards.

[0042] Third, by deploying a temperature and pressure prediction model and acquiring relevant historical data through a data acquisition module, the model is trained by inputting the labeled historical dataset into the temperature and pressure prediction model. Based on the purification time data of the dimethyl carbonate purification tower, the reaction time data of the EMC reaction tower, and the light-light ...

[0043] Fourth, the temperature and pressure prediction model consists of an input layer, a hidden layer, and an output layer. The input layer has three channels, used to input temperature data, pressure data, and corresponding time data, facilitating the subsequent extraction of feature relationships between these data by the hidden layer. The hidden layer comprises multiple layers to capture the relationships between the input temperature and pressure data and their corresponding time data. The output layer outputs the predicted temperature and pressure data and includes detailed calculation formulas for the hidden layer's output. Z k = f ( w k1 * X 1 +w k2 * X 2+···+ w ki * X i + w kn * X n This enables accurate feature capture through the hidden layer, thereby outputting accurate temperature and pressure prediction results. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the safety control method in the preparation process of methyl ethyl carbonate according to the present invention.

[0045] Figure 2 This is a schematic diagram of the amplifier circuit of the present invention.

[0046] Figure description: R1 is the first resistor, R2 is the second resistor, R3 is the third resistor, R4 is the fourth resistor, R5 is the fifth resistor, R6 is the sixth resistor, C1 is the first capacitor, and DA is the differential amplifier. Detailed Implementation

[0047] The following is in conjunction with the appendix Figures 1-2 The present invention will be further described in detail below:

[0048] Example 1

[0049] See appendix Figure 1 As shown, a safety control method in the preparation process of methyl ethyl carbonate includes the following steps:

[0050] S1: Industrial-grade dimethyl carbonate is fed into the dimethyl carbonate purification tower. The pressure inside the tower is monitored by a pressure detection unit. If the pressure reading is outside the preset range, the pressure is adjusted by a pressure regulating unit until the reading falls within the preset range. The industrial-grade dimethyl carbonate is purchased externally, and its purity does not meet the requirements for EMC reactions; therefore, it needs to be purified in the dimethyl carbonate purification tower. The dimethyl carbonate purification tower, also known as the DMC purification tower, requires processing at 50~55℃ and -0.06~0.08MPa. Because processing must be carried out under these temperature and pressure conditions, the pressure and temperature must be adjusted to these ranges to ensure efficient purification.

[0051] The overhead gas from the purification tower, consisting of light components, is condensed and sent to an industrial-grade DMC intermediate tank as a raw material for EMC / DEC synthesis. The heavy components from the bottom of the tower are also used as raw materials for EMC / DEC synthesis. Liquid material drawn from the side stream of the DMC purification tower is cooled by a cooler and then sent to electronic-grade DMC product tanks. The non-condensable gas (G1) generated during the condensation of the overhead gas from the DMC purification tower is collected and sent to the tail gas treatment system for incineration in an RTO furnace.

[0052] S2: After purification by the dimethyl carbonate purification tower, the output dimethyl carbonate is tested by the purity detection unit to determine whether the purity of the output dimethyl carbonate is within the preset purity range. If yes, proceed to step S3; otherwise, the output dimethyl carbonate is returned to the dimethyl carbonate purification tower for re-purification. To ensure that the purity meets the requirements of the EMC reaction, it is necessary to test the purity. If the purity does not meet the corresponding requirements, it is returned to the purification tower for further purification. This effectively ensures the purity of the raw materials for the subsequent EMC reaction, enabling the EMC reaction tower to react fully and efficiently, while ensuring the safety of the reaction process.

[0053] S3: The output dimethyl carbonate, catalyst sodium methoxide / methanol solution, and anhydrous ethanol are input into the raw material mixing unit according to the specified ratio for mixing. The uniformity of the mixed raw materials is detected by the uniformity detection unit, and it is determined whether the uniformity detection result of the mixed raw materials is within the preset uniformity range. If yes, proceed to step S4; otherwise, continue mixing the raw materials until the uniformity detection result is within the preset uniformity range. The uniformity detection process is to ensure that the raw materials are fully mixed, promote the efficient reaction process in the subsequent reaction tower, and shorten the reaction time.

[0054] The catalyst sodium methoxide / methanol solution, industrial-grade DMC, and anhydrous ethanol from the tank farm are mixed in a ratio of 0.0024:1:0.588 by pumping into the raw material mixing tank.

[0055] S4: The raw materials are uniformly fed into the EMC reaction tower. The gas pressure inside the EMC reaction tower is monitored. If the gas pressure is outside the preset range, the pressure is adjusted by the pressure regulating unit. Similarly, the temperature inside the EMC reaction tower is monitored by the temperature detection device. If the temperature is outside the preset range, the temperature is adjusted by the temperature regulating unit. Through this temperature and pressure regulation process, the gas pressure inside the reaction tower is ensured to meet the corresponding reaction conditions, allowing the reaction to proceed normally.

[0056] The mixed catalyst sodium methoxide / methanol solution, industrial-grade DMC, and anhydrous ethanol from the tank farm are pumped into the EMC reaction tower for reaction. Under normal pressure and 100-110℃ conditions, dimethyl carbonate and ethanol undergo transesterification in the reactor, with some dimethyl carbonate being converted into ethyl methyl carbonate.

[0057] S6: The bottom liquid in the EMC reaction tower is transferred to the waste catalyst concentration tank for treatment to obtain liquid and gaseous substances. The liquid substances are dried and the gaseous substances are transferred to the EMC light-duty removal tower for further treatment.

[0058] S7: Detect the temperature and pressure inside the EMC light residue removal tower. If the pressure in the EMC reaction tower is not within the preset pressure range, adjust the pressure through the pressure regulating unit. If the temperature is not within the preset temperature range, adjust the temperature through the temperature regulating unit.

[0059] S8: The liquid in the bottom of the EMC light removal tower is sent into the EMC product tower and cooled by the cooler. The temperature inside the cooler is monitored. If the temperature of the cooler is not within the preset range, the temperature is adjusted by the temperature regulation unit. The cooled liquid is then transported into the EMC finished product tank to obtain the EMC finished product.

[0060] In this embodiment, while performing step S1, the temperature inside the dimethyl carbonate purification tower is detected by a temperature detection unit, and it is determined whether the temperature detection value is within the preset temperature range. If the temperature detection value is not within the preset temperature range, the temperature inside the dimethyl carbonate purification tower is adjusted by a temperature adjustment unit.

[0061] Inside the EMC reaction tower, methyl ethyl carbonate (MEC) and ethanol undergo a transesterification reaction to produce diethyl carbonate. Methanol is generated as a byproduct during both reactions. While MEC, diethyl carbonate, and methanol are being produced in the EMC reaction tower, methanol is separated from MEC and diethyl carbonate. Methanol and a portion of the raw material DMC are distilled off the top of the tower as an azeotrope and pumped into a pressurized tower. The bottom liquid of the EMC reaction tower, consisting of excess dimethyl carbonate (all ethanol participated in the reaction) and the generated MEC and diethyl carbonate, is sent to the spent catalyst concentration tank. The azeotrope distilled off the top of the pressurized tower enters the atmospheric distillation tower. The bottom liquid of the atmospheric distillation tower, mainly consisting of recovered DMC, is returned to the feed tank. The azeotrope distilled off the top of the atmospheric distillation tower is then returned to the pressurized tower. The bottom liquid of the atmospheric distillation tower is a methanol byproduct.

[0062] The gaseous material after evaporation in the concentration tank enters the EMC light phase removal tower, while the liquid phase mainly consists of the catalyst sodium methoxide / methanol solution. This solution is dried in a vacuum dryer under steam heating and then recycled. The drying exhaust gas (G2) generated during the drying process is collected through a vacuum system and sent to an RTO incinerator for incineration. After multiple reuses and deactivation, the spent catalyst (S1) is disposed of as hazardous waste through an external contractor.

[0063] The gaseous material entering the EMC light component removal tower is heated to 110-120°C with steam at 10-20 kPa. The gaseous phase (mainly DMC) exiting from the top of the tower is recovered by condensation. The non-condensable gas (G3) generated during the condensation process is collected and sent to the RTO incinerator for treatment. The recovered DMC is reused in the EMC reaction tower. The bottom liquid is pumped into the EMC product tower for EMC purification at 80-85°C and -75 to -85 kPa. The light components at the top of the EMC product tower are returned to the EMC light component removal tower, and the bottom liquid is sent to the DEC purification process. The liquid material collected from the side stream is cooled by a cooler and sent to the electronic-grade EMC product tank.

[0064] Example 2

[0065] Based on Example 1, a leakage detection process is also included, as detailed below:

[0066] Leak detection devices are installed at designated locations on each production equipment to detect leaks throughout the entire preparation process of dimethyl carbonate (DMCO). The devices emit ultraviolet light at these locations. When a leak occurs, the volatilized DMCO is excited by the ultraviolet light in the ionization chamber of the detection device. The excited DMCO molecules are ionized into positively and negatively charged particles. These charged particles collide with the electrode plates, generating a detectable weak current. This weak current is amplified by an amplifier circuit. The magnitude of the detected current is displayed on a display module, showing the corresponding degree and location of the leak. An early warning module then provides an alert. Leak detection devices are installed at designated locations on each production equipment to detect leaks throughout the entire preparation process of dimethyl carbonate (DMCO). These devices emit ultraviolet light at the designated locations. When a leak of dimethyl carbonate or DMCO occurs, the volatilized dimethyl carbonate or DMCO is excited by the ultraviolet light in the ionization chamber of the detection device. The excited dimethyl carbonate or DMCO molecules are ionized into positively and negatively charged particles. These charged particles collide with the electrode plates, forming a detectable weak current. This weak current is amplified by an amplifier circuit, and the magnitude of the detected current is displayed to indicate the degree of leakage. This achieves rigorous leak monitoring. In the event of a leak, the corresponding leak information, including the degree and location of the leak, is transmitted to an early warning module for alert processing. This allows safety management personnel to promptly address leaks in the relevant equipment, ensuring leak safety throughout the entire production process.

[0067] In this embodiment, see Figure 2 As shown, the amplification circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first capacitor C1, and a differential amplifier DA. One end of the first resistor R1 is connected to the positive terminal of the current output, and the other end is connected to the negative terminal of the current output. One end of the second resistor R2 is connected to the first resistor R1, and the other end is connected to the inverting input terminal of the differential amplifier DA, the first capacitor C1, and the fourth resistor R4. The other ends of the fourth resistor R4 and the first capacitor C1 are both grounded through the sixth resistor R6 and connected to the output terminal of the amplified current. One end of the third resistor R3 is connected to the first resistor R1, and the other end is connected to the non-inverting input terminal of the differential amplifier DA and the fifth resistor R5. The positive terminal of the differential amplifier DA is connected to a 5V power supply, and the negative terminal is grounded. This circuit amplifies weak currents, enabling the detection of minor leaks and preventing large-scale safety hazards caused by delayed detection of leaks.

[0068] Example 3

[0069] Based on Example 1 or Example 2, a temperature and pressure prediction model is also deployed in each temperature and pressure regulation unit of the dimethyl carbonate purification tower, EMC reaction tower, and EMC light-light-removal tower. A historical dataset is constructed by acquiring historical purification time data and corresponding temperature and pressure data in the purification tower, historical EMC reaction time data and corresponding temperature and pressure data in the EMC reaction tower, and historical light-light-removal time data and corresponding temperature and pressure data in the EMC light-light-removal tower through the data acquisition module. The historical dataset is then labeled, and the labeled historical dataset is input into the temperature and pressure prediction model to train the model.

[0070] During the dimethyl carbonate purification stage, the purification time data of the dimethyl carbonate purification tower is acquired through the data acquisition module. The purification time data is then input into the temperature and pressure prediction model. The temperature and pressure prediction model predicts the temperature and pressure corresponding to the purification time data, plots the relationship between temperature and pressure and purification time, and generates a relationship diagram between temperature and pressure adjustment and purification time.

[0071] During the EMC reaction stage, the reaction time data of the EMC reaction tower is acquired through the data acquisition module. This data is then input into the temperature and pressure prediction model. The model predicts the temperature and pressure corresponding to the reaction time data, plots a graph showing the relationship between temperature and pressure and reaction time, and generates a graph showing the relationship between temperature and pressure adjustment and reaction time. During the EMC light-duty removal stage, the light-duty removal time data of the EMC light-duty removal tower is acquired through the data acquisition module. This data is then input into the temperature and pressure prediction model. The model predicts the temperature and pressure corresponding to the light-duty removal time data, plots a graph showing the relationship between temperature and pressure and light-duty removal time, and generates a graph showing the relationship between temperature and pressure adjustment and light-duty removal time.

[0072] The temperature regulation unit and the pressure regulation unit directly obtain the temperature and pressure regulation amounts that change with time in each stage through the temperature and pressure regulation amount versus purification time graph, the temperature and pressure regulation amount versus reaction time graph, and the temperature and pressure regulation amount versus light removal time graph. Based on the temperature and pressure regulation amounts, they realize the advance adjustment of temperature and pressure so that the specified temperature and pressure can be reached at the corresponding time points.

[0073] By deploying a temperature and pressure prediction model and acquiring relevant historical data through a data acquisition module, the model is trained using labeled historical datasets. Based on purification time data from the dimethyl carbonate purification tower, reaction time data from the EMC reaction tower, and light-light ...

[0074] In this embodiment, during the process of temperature and pressure regulation by the temperature regulation unit and the pressure regulation unit, the temperature detection unit and the pressure detection unit respectively detect the temperature and pressure of the corresponding equipment in real time, and determine whether the prediction result of the temperature and pressure prediction model is accurate based on the real-time detection result. If it is inaccurate, the inaccurate temperature or pressure and the corresponding time point are fed back to the temperature regulation unit and the pressure regulation unit to adjust the temperature and pressure regulation amount.

[0075] Example 4

[0076] Based on Embodiment 1, Embodiment 2, or Embodiment 3, the temperature and pressure prediction model is a neural network model, including an input layer, a hidden layer, and an output layer. The input layer has three channels, used to input temperature data, pressure data, and corresponding time data, respectively. The corresponding time data includes purification time data, EMC reaction time data, and EMC light removal time data. The hidden layer has multiple layers to capture the relationship between the input temperature and pressure data and the corresponding time data. The output layer outputs the predicted temperature and pressure data. The temperature and pressure prediction model has an input layer, a hidden layer, and an output layer. The input layer has three channels, used to input temperature data, pressure data, and corresponding time data, which facilitates the subsequent extraction of feature relationships between temperature data, pressure data, and corresponding time data by the hidden layer.

[0077] In this embodiment, the output calculation formula of the hidden layer is as follows:

[0078] Z k = f ( w k1 * X 1 +w k2 * X 2+···+ w ki * Xi + w kn * X n );

[0079] in, Z k The output of the hidden layer, f It is a nonlinear function. w k1 The weights are the values ​​between the first node of the input layer and the kth node of the hidden layer. w k2 The weights are the values ​​between the second node in the input layer and the kth node in the hidden layer. w ki For the input layer i The weight between the node and the k-th node in the hidden layer w kn For the input layer n Nodes and Hidden Layers k Weights between nodes X 1 represents the input of the first node in the input layer. X 2 represents the input of the second node in the input layer. X i For the input layer i The input of the node, X n For the input layer n The input to the node.

[0080] The hidden layer has multiple layers to accurately capture the relationship between temperature and pressure data and their corresponding time data. The output layer is used to output the predicted temperature and pressure data and sets the detailed output calculation formulas for the hidden layers. Z k = f ( w k1 * X 1 +w k2 * X 2+···+ w ki * X i + w kn * X n This enables accurate feature capture through the hidden layer, thereby outputting accurate temperature and pressure prediction results.

[0081] In addition to extracting the relationship features between temperature and air pressure data and corresponding time data, the hidden layer also performs data dimensionality reduction and feature information extraction and classification. Through the processing of this hidden layer, the complexity of the data is reduced, and the neural network can process the input data more efficiently. By automatically learning the inherent laws and features of the input data, the hidden layer can better understand and process the data, thus achieving accurate prediction of temperature and air pressure.

[0082] A safety control system for the preparation process of methyl ethyl carbonate (MEC) is provided to implement the safety control method for the preparation process of MEC as described in any one of the claims. The system includes a data acquisition module, a purity detection unit, a uniformity detection unit, a pressure regulation unit, a temperature regulation unit, and a temperature and pressure prediction model. The data acquisition module has multiple units respectively arranged in a dimethyl carbonate purification tower, an EMC reaction tower, and an EMC light-weight removal tower. The data acquisition module includes a pressure detection unit and a temperature detection unit. The purity detection unit is located at the output end of the dimethyl carbonate purification tower, and the uniformity detection unit is located inside the raw material mixing unit. The pressure regulation unit and the temperature regulation unit are connected to the dimethyl carbonate purification tower, the EMC reaction tower, and the EMC light-weight removal tower. The temperature and pressure prediction model is connected to the data acquisition module, the pressure regulation unit, and the temperature regulation unit.

[0083] The data acquisition module is used to acquire historical and real-time data from the dimethyl carbonate purification tower, EMC reaction tower, and EMC light-light removal tower. The uniformity detection unit is used to detect the uniformity of the raw materials in the raw material mixing unit. The pressure regulation unit is used to regulate the pressure in the dimethyl carbonate purification tower, EMC reaction tower, and EMC light-light removal tower. The temperature regulation unit is used to regulate the temperature in the dimethyl carbonate purification tower, EMC reaction tower, and EMC light-light removal tower. The temperature and pressure prediction model is used to predict the temperature and pressure of the dimethyl carbonate purification tower, EMC reaction tower, and EMC light-light removal tower at corresponding times based on the purification time data of the dimethyl carbonate purification tower, the reaction time data of the EMC reaction tower, and the light-light removal time data of the EMC light-light removal tower.

[0084] In summary, the safety control method and system for the preparation process of methyl ethyl carbonate (ME) provided by this invention, by deploying leak detection devices at designated locations in each production equipment, performs leak detection throughout the entire ME preparation process. The leak detection devices emit ultraviolet light at designated locations. When a leak of dimethyl carbonate or ME is detected, the volatilized dimethyl carbonate or ME is excited by ultraviolet light in the ionization chamber of the leak detection device. The excited dimethyl carbonate or ME molecule is ionized into positively and negatively charged particles. These charged particles collide with the electrode plate, forming a detectable weak current. This weak current is amplified by an amplification circuit, and the magnitude of the detected current is displayed to indicate the degree of leakage. This achieves rigorous leak monitoring, allowing for timely handling of leaks and ensuring leak safety throughout the entire production process. The amplification circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor, and a differential amplifier. This amplification of the weak current enables the detection of micro-leakages and avoids the situation where leaks become large enough to cause significant safety hazards.

[0085] By deploying a temperature and pressure prediction model, the data acquisition module obtains relevant historical data, which is then labeled. This labeled historical dataset is input into the temperature and pressure prediction model for training. Temperature and pressure predictions are made based on purification time data from the dimethyl carbonate purification tower, reaction time data from the EMC reaction tower, and light-light ... The hidden layer has multiple layers to capture the relationship between the input temperature and pressure data and the corresponding time data. The output layer is used to output the predicted temperature and pressure data and sets the detailed output calculation formula of the hidden layer, so that the hidden layer can accurately capture features and output accurate temperature and pressure prediction results.

Claims

1. A safety control method for the preparation process of methyl ethyl carbonate, characterized in that, Includes the following steps: S1: Industrial-grade dimethyl carbonate is fed into the dimethyl carbonate purification tower. The gas pressure inside the dimethyl carbonate purification tower is detected by the gas pressure detection unit. When the gas pressure detection value is not within the preset gas pressure range, the gas pressure inside the dimethyl carbonate purification tower is adjusted by the gas pressure adjustment unit until the gas pressure detection value is within the preset gas pressure range. S2: After purification by the dimethyl carbonate purification tower, the output dimethyl carbonate is tested by the purity detection unit to determine whether the purity of the output dimethyl carbonate is within the preset purity range. If yes, proceed to step S3; otherwise, return the output dimethyl carbonate to the dimethyl carbonate purification tower for re-purification. S3: Input the output dimethyl carbonate, catalyst sodium methoxide / methanol solution and anhydrous ethanol into the raw material mixing unit according to the specified ratio for mixing, and perform uniformity detection on the mixed raw material through the uniformity detection unit, and determine whether the uniformity detection result of the mixed raw material is within the preset uniformity range. If yes, proceed to step S4; otherwise, continue mixing the raw material until the uniformity detection result is within the preset uniformity range. S4: Feed the uniform raw material into the EMC reaction tower, detect the gas pressure in the EMC reaction tower, and if the gas pressure in the EMC reaction tower is not within the preset gas pressure range, adjust the gas pressure through the gas pressure regulating unit. Detect the temperature in the EMC reaction tower through the temperature detection device, and if the temperature is not within the preset temperature range, adjust the temperature through the temperature regulating unit. S5: The bottom liquid in the EMC reaction tower is transferred to the waste catalyst concentration tank for treatment to obtain liquid and gaseous substances. The liquid substances are dried and the gaseous substances are transferred to the EMC light-duty removal tower for further treatment. S6: Detect the temperature and pressure inside the EMC light residue removal tower. If the pressure in the EMC reaction tower is not within the preset pressure range, adjust the pressure through the pressure regulating unit. If the temperature is not within the preset temperature range, adjust the temperature through the temperature regulating unit. S7: The bottom liquid of the EMC light removal tower is sent into the EMC product tower. After being cooled by the cooler, the temperature inside the cooler is detected. If the temperature of the cooler is not within the preset range, the temperature is adjusted by the temperature adjustment unit. The cooled substance is then transported into the EMC finished product tank to obtain the EMC finished product. It also includes the leak detection process, as detailed below: Leak detection devices are installed at designated locations on each production equipment to detect leaks throughout the entire preparation process of dimethyl carbonate (DMCO). The devices emit ultraviolet light at these locations. When a leak occurs, the volatilized DMCO is excited by the ultraviolet light in the ionization chamber of the detection device. The excited DMCO molecules are ionized into positively and negatively charged particles. These charged particles collide with the electrode plates, generating a detectable weak current. This weak current is amplified by an amplifier circuit. The magnitude of the detected current is displayed on a display module, showing the corresponding degree and location of the leak. An early warning module then provides an alert.

2. The safety control method for the preparation process of methyl ethyl carbonate according to claim 1, characterized in that, Simultaneously with step S1, the temperature inside the dimethyl carbonate purification tower is detected by the temperature detection unit, and it is determined whether the temperature detection value is within the preset temperature range. If the temperature detection value is not within the preset temperature range, the temperature inside the dimethyl carbonate purification tower is adjusted by the temperature adjustment unit.

3. The safety control method for the preparation process of methyl ethyl carbonate according to claim 1, characterized in that, The amplifier circuit includes a first resistor (R1), a second resistor (R2), a third resistor (R3), a fourth resistor (R4), a fifth resistor (R5), a sixth resistor (R6), a first capacitor (C1), and a differential amplifier (DA). One end of the first resistor (R1) is connected to the positive terminal of the current output, and the other end is connected to the negative terminal of the current output. One end of the second resistor (R2) is connected to the first resistor (R1), and the other end is connected to the inverting input terminal of the differential amplifier (DA), the first capacitor (C1), and the fourth resistor (R4), respectively. The other end of the fourth resistor (R4) and the other end of the first capacitor (C1) are both grounded through the sixth resistor (R6) and connected to the output terminal of the amplified current. One end of the third resistor (R3) is connected to the first resistor (R1), and the other end is connected to the non-inverting input terminal of the differential amplifier (DA) and the fifth resistor (R5). The positive terminal of the power supply of the differential amplifier (DA) is connected to a 5V power supply, and the negative terminal is grounded.

4. The safety control method for the preparation process of methyl ethyl carbonate according to claim 2, characterized in that, Temperature and pressure prediction models are deployed in each temperature and pressure regulation unit of the dimethyl carbonate purification tower, EMC reaction tower, and EMC light component removal tower. Historical datasets are constructed by acquiring historical purification time data and corresponding temperature and pressure data in the purification tower, historical EMC reaction time data and corresponding temperature and pressure data in the EMC reaction tower, and historical light component removal time data and corresponding temperature and pressure data in the EMC light component removal tower. The historical datasets are then labeled and input into the temperature and pressure prediction models to train the models.

5. The safety control method for the preparation process of methyl ethyl carbonate according to claim 4, characterized in that, During the dimethyl carbonate purification stage, the purification time data of the dimethyl carbonate purification tower is acquired through the data acquisition module. The purification time data is input into the temperature and pressure prediction model. The temperature and pressure prediction model predicts the temperature and pressure corresponding to the purification time data, plots the relationship between temperature and pressure and purification time, and generates a relationship between temperature and pressure adjustment and purification time. During the EMC reaction stage, the reaction time data of the EMC reaction tower is acquired through the data acquisition module. The reaction time data is input into the temperature and pressure prediction model. The temperature and pressure prediction model predicts the temperature and pressure corresponding to the reaction time data, plots the relationship between temperature and pressure and reaction time, and generates a relationship between temperature and pressure adjustment and reaction time. During the EMC light-light removal stage, the light-light removal time data of the EMC light-light removal tower is acquired through the data acquisition module. The light-light removal time data is input into the temperature and pressure prediction model. The temperature and pressure prediction model predicts the temperature and pressure corresponding to the light-light removal time data, plots the relationship between temperature and pressure and light-light removal time, and generates a relationship between temperature and pressure adjustment and light-light removal time. The temperature regulation unit and the pressure regulation unit directly obtain the temperature and pressure regulation amounts that change with time in each stage through the temperature and pressure regulation amount versus purification time graph, the temperature and pressure regulation amount versus reaction time graph, and the temperature and pressure regulation amount versus light removal time graph. Based on the temperature and pressure regulation amounts, they realize the advance adjustment of temperature and pressure so that the specified temperature and pressure can be reached at the corresponding time points.

6. The safety control method for the preparation process of methyl ethyl carbonate according to claim 5, characterized in that, During the process of temperature and pressure regulation by the temperature regulation unit and the pressure regulation unit, the temperature detection unit and the pressure detection unit respectively detect the temperature and pressure of the corresponding equipment in real time, and judge whether the prediction result of the temperature and pressure prediction model is accurate based on the real-time detection results. If it is inaccurate, the inaccurate temperature or pressure and the corresponding time point are fed back to the temperature regulation unit and the pressure regulation unit to adjust the temperature and pressure regulation amount.

7. The safety control method for the preparation process of methyl ethyl carbonate according to claim 5, characterized in that, The temperature and pressure prediction model is a neural network model, including an input layer, a hidden layer, and an output layer. The input layer has three channels, which are used to input temperature data, pressure data, and corresponding time data, respectively. The corresponding time data are purification time data, EMC reaction time data, and EMC light removal time data. The hidden layer has multiple layers, which are used to capture the relationship between the input temperature and pressure data and the corresponding time data. The output layer is used to output the predicted temperature and pressure data.

8. The safety control method for the preparation process of methyl ethyl carbonate according to claim 7, characterized in that, The output calculation formula for the hidden layer is as follows: Z k = f ( w k1 * X 1 +w k2 * X 2+···+ w ki * X i + w kn * X n )； in, Z k The output of the hidden layer, f It is a nonlinear function. w k1 The weights are the values ​​between the first node of the input layer and the kth node of the hidden layer. w k2 The weights are the values ​​between the second node in the input layer and the kth node in the hidden layer. w ki For the input layer i The weight between the node and the k-th node in the hidden layer w kn For the input layer n Nodes and Hidden Layers k Weights between nodes X 1 represents the input of the first node in the input layer. X 2 represents the input of the second node in the input layer. X i For the input layer i The input of the node, X n For the input layer n The input to the node.

9. A safety control system for the preparation process of methyl ethyl carbonate, used to implement the safety control method for the preparation process of methyl ethyl carbonate as described in any one of claims 1-8, characterized in that, The system includes a data acquisition module, a purity detection unit, a uniformity detection unit, a pressure regulation unit, a temperature regulation unit, and a temperature and pressure prediction model. The data acquisition module has multiple units, which are respectively arranged in the dimethyl carbonate purification tower, the EMC reaction tower, and the EMC light component removal tower. The data acquisition module includes a pressure detection unit and a temperature detection unit. The purity detection unit is arranged at the output end of the dimethyl carbonate purification tower, and the uniformity detection unit is arranged inside the raw material mixing unit. The pressure regulation unit and the temperature regulation unit are connected to the dimethyl carbonate purification tower, the EMC reaction tower, and the EMC light component removal tower. The temperature and pressure prediction model is connected to the data acquisition module, the pressure regulation unit, and the temperature regulation unit. The data acquisition module is used to acquire various historical and real-time data from the dimethyl carbonate purification tower, EMC reaction tower, and EMC light component removal tower. The uniformity detection unit is used to detect the uniformity of the raw materials in the raw material mixing unit; The pressure regulating unit is used to regulate the pressure in the dimethyl carbonate purification tower, the EMC reaction tower and the EMC light component removal tower. The temperature control unit is used to regulate the temperature inside the dimethyl carbonate purification tower, the EMC reaction tower, and the EMC light component removal tower. The temperature and pressure prediction model is used to predict the temperature and pressure of the dimethyl carbonate purification tower, the EMC reaction tower, and the EMC light-light removal tower at corresponding times based on the purification time data of the dimethyl carbonate purification tower, the reaction time data of the EMC reaction tower, and the light-light removal time data of the EMC light-light removal tower.

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