A temperature control method and reaction device for thermotropic liquid crystal polyester synthesis reactor

Abstract

The present invention belongs to the technical field of thermotropic liquid crystal polyester synthesis, and particularly relates to a temperature control method and reaction device for a thermotropic liquid crystal polyester synthesis reactor. The present invention stops heating when the thermotropic liquid crystal polyester acylation reaction reaches a predetermined temperature, and combines the reactor with evacuation to make the feed liquid boil at an appropriate temperature and keep the temperature constant; in the later stage of the reaction, when the heat release slows down and the temperature is lowered by the evaporation of the feed liquid, the temperature balance is maintained by moderate heating and reducing the condensation and reflux of by-products, thereby reducing the influence of "flying temperature" on the product quality. The synthesis reaction device of the present invention realizes the effect of adjusting the gas pressure by temperature and controlling the temperature by gas pressure by linking the feed liquid temperature sensor and the gas phase temperature sensor in the reactor with the vacuum regulating valve. Therefore, the boiling state of the feed liquid in the reactor is used to reduce the "flying temperature" of the thermotropic liquid crystal polyester acylation reaction, and it is beneficial to improve the boiling mixing of the materials in the feed liquid, improve the reaction efficiency and material utilization rate.

Description

Technical Field

[0001] The invention belongs to the technical field of thermotropic liquid crystal polyester synthesis, and particularly relates to a temperature control method and a reaction device for a thermotropic liquid crystal polyester synthesis reaction kettle. Background Art

[0002] As a high-performance engineering plastic, fully aromatic liquid crystal polyester has very few entanglements in the molten state due to its rigid molecular chain structure, and the molecular chain is very easy to be oriented in the shear flow direction, and has excellent special properties, such as high strength and high modulus, excellent heat resistance and melt fluidity, excellent thermal stability and mechanical stability, low water absorption, high chemical corrosion resistance, and excellent flame retardant and electrical insulation properties. At present, this type of liquid crystal polyester has been widely used in high-performance fibers, electronic appliances, small thin-walled precision parts and other fields.

[0003] The steps of preparing liquid crystal polyesters by the current melt transesterification process can generally be divided into acylation, pre-condensation and final condensation. Unlike the production process of semi-aromatic polyesters, in which highly active primary alcohols such as ethylene glycol and butanediol can directly undergo esterification with terephthalic acid, since the monomers used to prepare liquid crystal polyesters, such as p-hydroxybenzoic acid (HBA), have low activity, they need to be properly modified before reacting with aromatic carboxylic acids. The acylation reaction is to react the aromatic hydroxyl group with an acylating agent such as acetic anhydride at a certain temperature to generate an acetoxy group with high reaction activity.

[0004] Reactors are widely used in the fields of petroleum, chemical industry, rubber, pesticides and dyes. They can be used to complete processes such as vulcanization, nitration, hydrogenation and polymerization, and are an important reaction equipment. Acylation reactions are inseparable from acylation reactors. In the acylation reaction of the preparation process of fully aromatic liquid crystal polyesters, the heat transfer oil is usually first set to the reaction temperature required by the process, and the materials are heated to start the reaction. As the temperature of the reactor rises, monomers such as p-hydroxybenzoic acid begin to dissolve and undergo acylation reaction with acid anhydride to generate p-acetoxybenzoic acid (ABA). However, the acylation reaction process is usually accompanied by a relatively strong exothermic phenomenon, causing the temperature of the material in the reactor to exceed the temperature required by the process, resulting in "flying temperature". Excessive reaction temperature will cause side reactions such as decarboxylation of the monomers, resulting in an imbalance in the molar ratio of the monomers, ultimately affecting the product quality, and also causing adverse effects on the safe and stable operation of the device. Moreover, in the actual production process, the mass of the monomers in the reactor is much greater than that in the laboratory or pilot stage. The reaction heat generated when a large amount of monomers undergo acylation reaction will cause the temperature of the reaction system to rise sharply, and the "flying temperature" phenomenon will be more severe.

[0005] After the acylation reaction is completed, the temperature needs to be raised in time to remove by-products, and then pre-condensation and final condensation reactions are carried out (which can be carried out in the acylation reactor). When the melt in the reactor reaches a predetermined viscosity, it is discharged from the reactor for granulation or crushing to obtain a liquid crystal polyester product. Therefore, accurately controlling the temperature of the acylation reactor is a key technical issue in improving product quality.

[0006] Patent document CN110527070A discloses a one-pot method for preparing thermotropic liquid crystal polyester, which uses a common process and method, that is, after the acylation reaction is completed, byproducts such as acetic anhydride are discharged, and then nitrogen is blown in for heating and polycondensation. However, this method is difficult to control the "flying temperature".

[0007] Patent document CN111408320A discloses a synthesis device for producing thermotropic liquid crystal polyester, which needs to be provided with an inner window on the reactor. During the acylation reaction, when white monomers are observed to adhere to the reactor wall through the inner window, the distilled acetic acid is sprayed back into the reactor. The main purpose is to use the sprayed acetic acid to bring the easily sublimated and adhered p-acetoxybenzoic acid (ABA) monomer back into the reaction system. At the same time, a cooling assembly is also provided in the reactor heat exchange interlayer to cool the heat transfer oil. However, this method not only needs to provide an inner window on the reactor. This scheme also needs to observe the sublimation of the monomers and the adhesion to the reactor wall at all times. It is important that when a lower reaction temperature is required, the system will not have the phenomenon of distillation of acetic acid and sublimation of the monomers, which limits the practical application of the invention to a certain extent. In addition, the device sets the sprayer inside the reactor. Although it can achieve a certain cooling effect through the sprayed acetic acid, it is easily blocked by monomers and oligomers during long-term use and fails. In addition, although the device can use cooling components and sprayers to reduce the temperature, there are still problems of uneven and inaccurate temperature control of the reactor.

[0008] Therefore, for the temperature control method of the acylation reaction in the synthesis process of liquid crystal polyester, a fast cooling system is required to maintain the reaction temperature constant or within a narrow temperature fluctuation range. Summary of the invention

[0009] In view of the above problems, the purpose of the present invention is to provide a temperature control method and reaction device for a thermotropic liquid crystal polyester (TLCP) synthesis reactor. The inventors found through research on the synthesis process of thermotropic liquid crystal polyester (TLCP) that during the TLCP synthesis process, the boiling point of the feed liquid in the acylation reaction device (pre-polycondensation and final polycondensation reactions can also be carried out in one pot) and the pressure of the gas phase system in the acylation reaction device are nonlinear; however, the acylation reaction feed liquid can be controlled in a boiling state based on dynamic regulation within a certain range, through gas phase system pressure regulation, etc., so as to maintain a narrow temperature fluctuation range and make the boiling temperature range meet the appropriate temperature of the acylation reaction. In this way, the acylation reaction temperature can be controlled more accurately, reducing the impact of "flying temperature" on the product.

[0010] Based on the above findings and technical ideas, the present invention improves the temperature control method of the TLCP synthesis reactor and improves the TLCP reaction device to match the temperature control method.

[0011] First, the present invention provides a temperature control method for a TLCP synthesis reactor, in particular a temperature control method for a TLCP acylation reactor. Of course, the TLCP acylation reactor can also perform subsequent pre-polycondensation and final polycondensation reactions.

[0012] Specifically, the method comprises the following steps:

[0013] S0 parameter settings:

[0014] S01 Setting the parameters of the thermotropic liquid crystal polyester acylation reaction liquid: According to the appropriate temperature of the thermotropic liquid crystal polyester acylation reaction, set the target boiling temperature T and the lower limit temperature T of the liquid. 1 , the T is 100°C to 150°C, preferably 120°C to 140°C; the T 1 T-2℃~T-10℃. 1 The difference from T can be left with a larger margin, such as T-5℃, T-10℃, according to the thermodynamic characteristics of different reaction systems (such as differences in reaction exothermic rates caused by different catalysts).

[0015] S02 Setting of gas phase system parameters for thermotropic liquid crystal polyester acylation reaction: Setting the gas phase temperature threshold Tx and gas phase pressure reduction range Py for gas phase system pressure regulation; Tx is the gas phase temperature corresponding to the boiling of the feed liquid, and x is 5°C to 50°C; P is the gas phase pressure corresponding to the boiling of the feed liquid and the gas phase temperature is Tx, and y is 0 to 5kPa.

[0016] S03 Setting of nitrogen pressure control parameters for thermotropic liquid crystal polyester acylation reaction: Setting nitrogen pressure control parameter P+z, where z is the excess pressure value, and z is 0 to 10 kPa.

[0017] S1 acylation reaction and temperature control:

[0018] S11: Add monomers, acylation reagents and catalysts into the reactor, stir the materials, start heating, start condensation and reflux, and evaporate the by-products and condense and reflux into the reactor.

[0019] S12: When the temperature of the liquid in the reactor reaches T, stop heating and evacuate the reactor at a rate of 10 kPa / min to 50 kPa / min; as the gas pressure in the reactor drops to P, the liquid in the reactor boils and the gas phase temperature in the reactor reaches Tx.

[0020] S13: When the gas phase temperature in the reactor reaches Tx, the gas pressure in the reactor is controlled to be Py; as the feed liquid in the reactor evaporates and the by-products evaporate and condense back into the reactor, the heat in the reactor decreases.

[0021] S14: When the temperature of the liquid in the reactor is less than T and greater than T 1 When the temperature of the liquid in the reactor drops to T 1 , you can choose to start heating to reduce the speed at which the by-products evaporate and condense back into the reactor, and maintain the temperature balance of the liquid in the reactor until the reaction is completed.

[0022] The parameter settings can be fixed preset values; they can also be specifically set before different batches of reactions according to the feed amount and catalyst. Depending on the control method or location of the reaction device, the parameter settings can be set simultaneously, or in steps or locations. For example, when an external heating device is used, T or T 1 Two thresholds, which are transmitted and feedback-controlled by sensors located in the feed liquid of the acylation reaction device. For another example: when a gas extraction device and a gas pressure control device externally connected to the reactor are used, a gas phase temperature / gas phase pressure sensor and a gas extraction device can usually be set on the upper part of the reactor, so as to set the control thresholds of the gas phase temperature / gas phase pressure, such as Tx, Py, and P+z, in the control mechanism.

[0023] The aforementioned temperature control method uses the term "step" only to facilitate those skilled in the art to understand the principle of the temperature control method. Obviously, steps S01 to S03 of the aforementioned temperature control method are not necessarily performed in sequence; step S0 and step S1 are not necessarily performed separately. For example, when the same control system is used to control the reaction system as a whole, the temperature and pressure parameters can be preset in the control system, and the reaction process does not need to set the temperature or pressure parameters in each step. When different parameters are regulated by independent different control systems, the temperature or pressure parameters can be set in each step.

[0024] When the temperature control method of the above TLCP synthesis reactor is adopted:

[0025] The monomer is selected from one or more of p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 4,4-biphenylene glycol, hydroquinone, p-aminophenol and derivatives thereof.

[0026] The acylating agent is selected from any one of acetic anhydride, propionic anhydride, butyric anhydride and valeric anhydride; more preferably acetic anhydride.

[0027] The catalyst can be selected from metal acetates (such as magnesium acetate, zinc acetate, sodium acetate, magnesium acetate), and can also be selected from organic base compounds such as 1-methylimidazole, 1-ethylimidazole, 1-propylimidazole, 1-butylimidazole, 1-hexylimidazole, 2-aminoimidazole, 3-aminopyridine, 4-aminopyridine, 3-dimethylaminopyridine, 4-dimethylaminopyridine, 3-pyrrolidinylpyridine, 4-pyrrolidinylpyridine, 2-aminopyrimidine, 3-aminopyrimidine, 4-aminopyrimidine, etc.

[0028] Secondly, the present invention provides a synthesis reaction device, which can be used for a reaction system in which the reaction temperature of the feed liquid needs to be controlled and the reaction temperature of the feed liquid can be adjusted by controlling the gas pressure of the gas phase in the reaction device, including but not limited to the TLCP acylation reaction system.

[0029] The synthesis reaction device comprises a reaction device body, a feed liquid heating component, a condensing medium transmission component, a gas phase pressure control component and a liquid collection tank; the reaction device body comprises a reactor; the feed liquid heating component comprises a feed liquid temperature sensor, a heating mechanism (such as a jacket, a coil or an electric heating element), and a heating control mechanism (such as a heat medium regulating valve / electric heating power or an on-off regulator); the condensing medium transmission component introduces the gas evaporated from the reactor into the condensing component and the liquid collection tank through a steam inlet pipe, the condensing component condenses the steam, and returns the condensed fluid to the reactor or extracts it through a reflux pipeline, the steam inlet pipe or A gas phase temperature sensor is provided at the top of the reactor; the gas phase pressure control component comprises a nitrogen replenishing system, an exhaust system and a pressure transmitter; the nitrogen replenishing system is openably and closably connected to the top of the reactor or the top of the condenser through a nitrogen pipeline and a nitrogen regulating valve; the exhaust system comprises a vacuum pipeline, a vacuum regulating valve and a vacuum pump; the vacuum regulating valve is located on the vacuum pipeline, and both ends of the vacuum pipeline are openably and closably connected to the vacuum pump and the top of the reactor respectively; the vacuum regulating valve is electrically connected to the feed liquid temperature sensor and the gas phase temperature sensor; the pressure transmitter is electrically connected to the nitrogen regulating valve and the vacuum regulating valve through a controller.

[0030] Generally speaking, in the art, the temperature sensing element of the feed liquid temperature sensor is generally arranged in the reactor to measure and feedback the feed liquid temperature in real time.

[0031] The term "electrical connection" includes wired connections formed by physical connections such as conductive lines and data lines, as well as wireless connections formed by electromagnetic signals, digital signals, etc.

[0032] The liquid collection tank is a device for collecting reaction waste liquid. Its purpose is related to environmental protection and / or material recycling. It can be replaced by a waste liquid pool in the art or other devices with equivalent functions.

[0033] Preferably, the condensing component includes a shell and tube condenser, a reflux distributor and a production pipeline; the shell and tube condenser receives gas from the steam inlet pipe and transports it to the reflux distributor, the reflux distributor transports the condensed fluid to the reflux pipeline and / or the production pipeline, and the production pipeline is connected to the liquid collection tank.

[0034] Preferably, the condensation component includes a spray condenser, a secondary condenser, a temporary storage tank, an overflow pipeline, an electromagnetic three-way valve, a spray pump, a spray pipeline and a balance pipe. The spray condenser receives gas from the steam inlet pipe and transports it to the secondary condenser and the liquid collection tank respectively, and the two ends of the balance pipe are connected to the spray condenser and the liquid collection tank respectively; the secondary condenser transports the condensed fluid to the temporary storage tank (during the TLCP acylation reaction, the temporary storage tank is used to temporarily store the condensed fluid such as acetic acid); the lower part of the temporary storage tank is connected to the spray condenser through the spray pump and the spray pipeline, and the upper part of the temporary storage tank is connected to the reflux pipeline and the liquid collection tank through the overflow pipeline and the electromagnetic three-way valve.

[0035] Preferably, a liquid seal is provided on the return pipeline of the condensing component.

[0036] Preferably, the vacuum pipeline includes a front vacuum pipeline, a vacuum buffer tank and a rear vacuum pipeline; the vacuum buffer tank is connected to the front vacuum pipeline and the rear vacuum pipeline respectively, the rear vacuum pipeline is connected to a vacuum pump; the front vacuum pipeline is connected to the reactor.

[0037] Preferably, the vacuum regulating valve is installed on the front vacuum pipeline.

[0038] In a preferred embodiment, the fore-vacuum pipeline is directly connected to the upper part of the condenser in an openable and closable manner; in another preferred embodiment, the fore-vacuum pipeline is indirectly connected to the upper part of the reactor through a steam inlet pipe; in another preferred embodiment, the fore-vacuum pipeline is indirectly connected to the upper part of the reactor through a shell and tube condenser or a spray condenser via a steam inlet pipe.

[0039] Preferably, the vacuum pump is one of a screw pump, a Roots pump and a diaphragm pump.

[0040] As for the reaction device body, a stirring mechanism may be usually provided inside the reactor to facilitate mixing of feed and liquid. For example, a feeding port, a discharging port and a stirring motor for driving the stirring mechanism may be provided on the reactor.

[0041] As for the liquid heating component, a commonly used heating jacket (with or without a coil) can be used. The heating method can be a thermal oil heating device or an electric heater. For example, the liquid heating component can include a heating jacket, a heat medium oil inlet pipe, a heat medium flow regulating valve and a heat medium oil outlet pipe arranged on the outer wall of the reactor 1. When the predetermined temperature is reached, the heat medium flow regulating valve is closed to stop the heat supply to the heating jacket. An automatic control system can also be used to automatically adjust the opening and closing and size of the heat medium flow regulating valve 6 according to the preset temperature to achieve automatic control.

[0042] The technology of the present invention has the following beneficial effects

[0043] (1) The temperature control method of the TLCP synthesis reactor of the present invention stops heating when the reaction reaches an appropriate temperature but releases heat rapidly. In addition, by virtue of the discovery that there is a nonlinear relationship between the state of the feed liquid in the acylation reaction device and the gas pressure of the gas phase system, the gas pressure in the acylation reaction device is controlled by exhaustion, so that the feed liquid is in a boiling state at an appropriate reaction temperature, thereby reducing temperature fluctuations and "temperature runaway" in the heating stage, and solving the problem of deviation from the actual set temperature caused by a large amount of heat release in the acylation reaction stage of TLCP.

[0044] (2) The temperature control method of the TLCP synthesis reactor of the present invention, in the late stage of the reaction, when the reaction heat release rate slows down and the temperature decreases due to reasons such as evaporation of the feed liquid, the recovery heating is combined with reducing the reflux rate of the evaporation and condensation of the by-products, so that the feed liquid temperature fluctuation can be more easily controlled. In this way, the feed liquid temperature is maintained to fluctuate around the set range until the reaction is completed.

[0045] (3) Due to the correlation between the boiling temperature of the material and the gas phase pressure, the temperature control method of the present invention is conducive to achieving higher temperature control accuracy, and is conducive to controlling the reaction temperature within a narrower range, so as to obtain a target product with a more controlled conversion rate and the amount of side reactions. In addition, since the pressure of the gas phase system is introduced as the main variable for controlling the temperature, there is no need to rely on the internal window to observe the monomer precipitation in the reactor to determine the timing of cooling. When the temperature and pressure parameters of the gas phase system are used for regulation, the dependence of the heat medium temperature in the present invention is weakened, and a higher temperature heat medium can be used, which is conducive to improving the operating efficiency of the slurry preheating stage and the temperature rise devolatilization stage by increasing the temperature of the heat medium.

[0046] (4) The synthesis reaction device of the present invention has a simple structure. There is no need to add an additional cooling system or observation window in the reactor or on the heat medium pipeline. There is no need to worry about the solidification of the material in the reactor. The internal parts of the reactor have a simple structure, and the design tolerance of the agitator is larger, which helps to ensure the stirring capacity of the reactor and improve the performance in the slurry dissolution and preheating stages.

[0047] (5) The synthetic reaction device of the present invention is equipped with devices related to by-product condensation and reflux, and devices related to gas suction and air pressure control. Therefore, the double cooling by gas extraction and pressure reduction combined with condensation and reflux can be used to suppress "temperature runaway" in the rapid heat release stage. And through the linkage control of the feed liquid temperature sensor and the gas phase temperature sensor and the vacuum control valve, the feed liquid and gas phase temperature data can be analyzed and processed in real time, and the corresponding control instructions are issued. The signal fed back to the vacuum control valve by the temperature sensor automatically controls the opening of the vacuum control valve, so that the feed liquid in the reactor is in a boiling state. This is more conducive to achieving faster cooling in combination with the condensation and reflux of the by-products, reducing "temperature runaway".

[0048] (6) The synthesis reaction device of the present invention is equipped with a by-product condensation reflux related device and a heating device, and the reflux distributor and other devices can adjust the reflux state. In the later stage of the reaction, the heat release slows down and the temperature fluctuation range is small. At this time, when the feed liquid temperature drops to a set threshold, the heating can be restarted and the reflux state can be adjusted. By adjusting the heating speed and the reflux speed, one increases and the other decreases, it is easier to maintain the feed liquid temperature within the set range.

[0049] (7) The volatilization of the liquid in the reactor can take away part of the heat generated by the acylation reaction. The steam is condensed and then refluxed into the reactor. On the one hand, it can further reduce the temperature in the reactor. On the other hand, the anhydride in the refluxed material can continue to participate in the reaction, thereby improving the material utilization rate and reaction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A logical flow diagram of the temperature control method of the TLCP synthesis reactor of the present invention;

[0051] Figure 2 A structural diagram of a TLCP acylation reaction device of the present invention;

[0052] Figure 3 It is a structural diagram of a reflux distributor;

[0053] Figure 4 This is another structural diagram of the TLCP acylation reaction device of the present invention;

[0054] In the figure, 1, reactor; 2, feeding port; 3, discharge port; 4, stirring motor; 5, heat medium oil inlet pipe; 6, heat medium flow regulating valve; 7, heat medium oil outlet pipe; 8, nitrogen pipeline; 9, nitrogen regulating valve; 10, feed liquid temperature sensor; 11, pressure transmitter; 12, steam inlet pipe; 13, gas phase temperature sensor; 14, tube condenser; 15, reflux distributor; 16, reflux pipeline; 17, liquid seal; 18, extraction pipeline ; 19. Liquid collection tank; 20. Front vacuum pipeline; 21. Vacuum regulating valve; 22. Vacuum buffer tank; 23. Rear vacuum pipeline; 24. Vacuum pump; 25. Condensate inlet; 26. Controller; 27. Drainage device; 28. Drainage rod; 29. ​​Spray condenser; 30. Secondary condenser; 31. Temporary storage tank; 32. Overflow pipeline; 33. Solenoid three-way valve; 34. Spray pump; 35. Spray pipeline; 36. Balance pipe. DETAILED DESCRIPTION

[0055] The technical ideas, solutions, effects, etc. of the present invention are described in detail below through specific embodiments in conjunction with the accompanying drawings. The embodiments are only exemplary descriptions of the present invention and are not to be regarded as limiting the protection scope of the present invention.

[0056] Please combine Figure 1 , 2 4. The logic flow chart or working principle diagram of the temperature control of the TLCP acylation reaction system by the synthesis reaction device of the present invention can be found in Figure 1 . Figure 2 , 4 They are two synthetic reaction devices that can be used to control the temperature of the TLCP acylation reaction system and reduce "temperature runaway". The main difference between the two is the difference in condensation strategy and condensation components. Figure 2 Adopting tube condensation scheme, Figure 4 Adopt spray condensation solution. Figure 3 for Figure 2 The schematic structural diagram of the reflux distributor 15 shows the structure of a reflux distributor 15 in the prior art.

[0057] Example 1 A synthesis reaction device and a temperature control method for TLCP acylation reaction

[0058] See also Figure 1 , 2 、3. Figure 1 This is a logical flow chart (or working principle diagram) for controlling the temperature of the TLCP acylation reaction system by the synthesis reaction device. Figure 2 A TLCP acylation reaction unit using a tube-in-tube condensation scheme. Figure 3 for Figure 2 Schematic diagram of the structure of the middle reflux distributor 15.

[0059] like Figure 2 , 3As shown: the synthesis reaction device includes a liquid collection tank 19 and:

[0060] The reaction device body is mainly composed of a reaction kettle 1, a feeding port 2, a discharging port 3, and a stirring motor 4;

[0061] The liquid heating component is mainly composed of a heat medium oil inlet pipe 5, a heat medium flow regulating valve 6, a heat medium oil outlet pipe 7, and a liquid temperature sensor 10;

[0062] A nitrogen replenishment system mainly composed of a nitrogen pipeline 8 and a nitrogen regulating valve 9; an exhaust system mainly composed of a front vacuum pipeline 20, a vacuum regulating valve 21, a vacuum buffer tank 22, a rear vacuum pipeline 23 and a vacuum pump 24; a gas phase pressure control component composed of the nitrogen replenishment system, the exhaust system and the pressure transmitter 11;

[0063] The shell and tube condensation system is mainly composed of a steam inlet pipe 12, a gas phase temperature sensor 13, a shell and tube condenser 14, a reflux distributor 15, a reflux pipeline 16, a liquid seal 17 and a production pipeline 18.

[0064] in Figure 3 In addition to connecting the reflux pipeline 16 and the production pipeline 18, the reflux distributor of the prior art also includes a condensate inlet 25, a controller 26, a flow guide 27, and a flow guide rod 28. The reflux distributor can control the working state of the reflux distributor 15 to be a full reflux state, a partial reflux state, a full production state, etc., so as to facilitate the adjustment of the reflux speed and state.

[0065] The vacuum regulating valve 21 is electrically connected to the liquid temperature sensor 10 and the gas phase temperature sensor 13; the pressure transmitter 11 is electrically connected to the nitrogen regulating valve 9 and the vacuum regulating valve 21 through the controller. The controller controls the vacuum regulating valve 21 or the nitrogen regulating valve 9 according to the air pressure parameter in the reactor 1 received by the pressure transmitter 11, thereby controlling the air pressure in the reactor 1 and determining the timing of nitrogen replenishment.

[0066] When in use, the material is fed in from the feed port 2, stirred by the stirring motor 4, and the reacted material can be discharged from the discharge port 3. When the liquid feed needs to be heated, the heat medium flow regulating valve 6 is opened, and the heat medium enters the heating jacket on the outer wall of the reactor 1 through the heat medium oil inlet pipe 5 for heating, and then flows out from the heat medium oil outlet pipe 7. The temperature sensing unit of the liquid feed temperature sensor 10 is arranged inside the reactor 1.

[0067] After the feeding is completed, the heat medium flow regulating valve 6 can be started for heating, and the full reflux state or partial reflux state can be opened before the preset target boiling temperature T of the feed liquid is reached (T is 100°C to 150°C, preferably 120 to 140°C). As the material heats up, the heat medium flow regulating valve 6 can be closed to stop heating when the feed liquid is heated to the target boiling temperature T. The vacuum pump 24 is turned on, and the exhaust rate is 10kPa / min to 50kPa / min. With the electrical connection and automatic feedback control between the feed liquid temperature sensor 10 and the vacuum regulating valve 21, the gas extraction speed can be controlled more accurately. The gas is discharged through the steam inlet pipe 12, the tube condenser 14, the front vacuum pipeline 20, the vacuum regulating valve 21, the vacuum buffer tank 22, the rear vacuum pipeline 23 and the vacuum pump 24 to reduce the gas pressure in the reactor 1. When the reaction is over-temperature, the full reflux state can be used to assist in cooling.

[0068] The gas phase temperature sensor 13 on the steam inlet pipe 12 is used to monitor the temperature of the gas phase in the reactor 1. The temperature sensing unit of the gas phase temperature sensor 13 can also be arranged on the upper part of the reactor 1. The gas pressure in the reactor 1 can be accurately controlled by the electrical connection and automatic feedback control between the gas phase temperature sensor 13 and the vacuum regulating valve 21.

[0069] When the gas phase temperature sensor 13 detects that the gas phase temperature in the reactor reaches Tx (x can be selected from 5 to 50°C), the gas pressure in the reactor 1 is controlled to Py through the vacuum regulating valve 21 (where P is the gas phase pressure corresponding to the boiling of the liquid and the gas phase temperature is Tx, and y is 0 to 5 kPa); when the pressure in the reactor is lower than the saturated vapor pressure of the material, the material in the reactor begins to boil and evaporate, and is maintained for a certain period of time.

[0070] As the liquid in the reactor boils and evaporates, the heat release slows down in the later stage of the reaction, and the evaporation takes away part of the heat and the temperature of the liquid begins to decrease. 1 Time (T 1 The preset lower limit temperature of the liquid feed can be selected from T-2°C to T-10°C, such as T-2°C, T-5°C or T-10°C), the vacuum pump 24 is turned off, and the pumping is stopped. The pressure transmitter 11 controls the nitrogen regulating valve 9 to open, and nitrogen is introduced into the reactor 1 through the nitrogen pipeline 8, thereby controlling the gas phase pressure in the reactor 1 to P+z (z is the excess pressure value, and the z value range can be selected from 0 to 10 kPa), and the boiling state is terminated.

[0071] Continue the reaction until the liquid temperature drops to T 1 The heat medium flow regulating valve 6 can be opened again for heating, and the reflux state can be adjusted. By adjusting the heating speed and the reflux speed, the temperature of the feed liquid can be kept balanced, thereby reducing the temperature fluctuation.

[0072] When the reaction reaches a high conversion rate, the heat release is not obvious, and the by-products need to be removed, the reflux distributor 15 is changed to a full extraction state to distill out the by-product carboxylic acid, and then a polycondensation reaction is carried out to obtain a liquid crystal polyester product.

[0073] The synthetic reaction device and the TLCP acylation reaction temperature control method have a wide range of applications. For example, the monomer used can be one or more of p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 4,4-biphenyl, hydroquinone, p-aminophenol and derivatives thereof; the acylation agent used can be any one of acetic anhydride, propionic anhydride, butyric anhydride and valeric anhydride. The catalyst used can be selected from metal acetates (such as magnesium acetate, zinc acetate, sodium acetate, magnesium acetate), and can also be selected from organic base compounds such as 1-methylimidazole, 1-ethylimidazole, 1-propylimidazole, 1-butylimidazole, 1-hexylimidazole, 2-aminoimidazole, 3-aminopyridine, 4-aminopyridine, 3-dimethylaminopyridine, 4-dimethylaminopyridine, 3-pyrrolidinylpyridine, 4-pyrrolidinylpyridine, 2-aminopyrimidine, 3-aminopyrimidine, 4-aminopyrimidine and the like.

[0074] Example 2 A synthesis reaction device and a temperature control method for TLCP acylation reaction

[0075] This embodiment provides another synthesis reaction device, which is different from the synthesis reaction device in Example 1 in that a spray condensation scheme is adopted. Figure 4 As shown. The spray condensation mechanism of the synthesis reaction device includes a spray condenser 29, a secondary condenser 30, a temporary storage tank 31, an overflow pipeline 32, an electromagnetic three-way valve 33, a spray pump 34, a spray pipeline 35 and a balance pipe 36. The gas in the steam inlet pipe 12 can enter the spray condenser 29, then enter the secondary condenser 30, and enter the temporary storage tank 31 after condensation. The condensed fluid in the temporary storage tank 31 can return to the spray condenser 29 through the spray pipeline 35 under the suction action of the spray pump 34, and assist in cooling the gas in the spray condenser 29. The condensed fluid in the temporary storage tank 31 can also enter the reflux pipeline 16 (leading to the reactor 1) or the liquid collection tank 19 through the overflow pipeline 32 under the control of the electromagnetic three-way valve 33. A part of the condensed fluid in the spray condenser 29 enters the liquid collection tank 19 through the balance pipe 36.

[0076] The electromagnetic three-way valve 33 can adjust the reflux state by opening or closing or adjusting the opening or closing degree, such as full reflux state, partial reflux state, and full extraction state. Obviously, the synthesis device can also be installed with a reflux distributor 15 as used in Example 1, such as replacing the electromagnetic three-way valve 33, and the two have similar functions, namely adjusting the reflux state.

[0077] After the acylation reaction is completed, the by-product acetic acid removal stage begins. At this time, the electromagnetic three-way valve 33 can be set to a full extraction state. The by-product acetic acid vapor in the reactor 1 enters the spray condenser 29 through the steam inlet pipe 12 and is sprayed and condensed by the cold acetic acid in the temporary storage tank 31. The condensed acetic acid liquid passes through the secondary condenser 30 and the temporary storage tank 31 and enters the liquid collection tank 19.

[0078] The synthetic reaction device and the TLCP acylation reaction temperature control method have a wide range of applications. For example, the monomer used can be one or more of p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 4,4-biphenyl, hydroquinone, p-aminophenol and derivatives thereof; the acylation agent used can be any one of acetic anhydride, propionic anhydride, butyric anhydride and valeric anhydride. The catalyst used can be selected from metal acetates (such as magnesium acetate, zinc acetate, sodium acetate, magnesium acetate), and can also be selected from organic base compounds such as 1-methylimidazole, 1-ethylimidazole, 1-propylimidazole, 1-butylimidazole, 1-hexylimidazole, 2-aminoimidazole, 3-aminopyridine, 4-aminopyridine, 3-dimethylaminopyridine, 4-dimethylaminopyridine, 3-pyrrolidinylpyridine, 4-pyrrolidinylpyridine, 2-aminopyrimidine, 3-aminopyrimidine, 4-aminopyrimidine and the like.

[0079] Since the synthesis reaction device is different from the device in Example 1 only in that a spray condensation scheme is adopted, the temperature control method is the same as that in Example 1.

[0080] Example 3 TLCP acylation reaction

[0081] The temperature control method and product characteristics of the TLCP acylation reaction of the present invention are investigated by comparing specific reactions and products. The target boiling temperature T (°C) of the feed liquid in the following examples can be selected according to the appropriate temperature of the TLCP acylation reaction. (P) and (Tx) can be selected by drawing a relationship diagram between the boiling temperature of the feed liquid and the gas pressure. The following catalysts are all 1-methylimidazole. The subsequent polycondensation reaction conditions of the following experimental examples and comparative examples are the same.

[0082] Three temperature and pressure control parameters were used to investigate the experimental examples. The temperature and pressure control parameters of Experimental Examples 1 to 3 are shown in Table 1. The reaction apparatus is the synthetic reaction apparatus of Example 1, and the volume of the reactor 1 is 20 L. The logical flow diagram of the synthetic reaction temperature control method is shown in Figure 1 .

[0083] Table 1 Temperature and pressure control parameters of Experimental Examples 1-3

[0084]

[0085] The materials charged in Experimental Examples 1 to 3 are: 5.967 kg of p-hydroxybenzoic acid, 3.162 kg of 6-hydroxy-2-naphthoic acid, 6.432 kg of acetic anhydride, and 1.826 g of catalyst.

[0086] In Experimental Example 1: After the feeding is completed, the heating is started, the heat medium temperature is 140°C, the reflux distributor 15 is set to a full reflux state, the heating is stopped when it reaches 120°C, and the vacuum is started at a vacuum rate of 10kPa / min. When the gas phase temperature reaches 110°C, the gas pressure of the gas phase is maintained at 45kPa (P is 50kPa). At this time, the feed liquid is boiling, and the feed liquid temperature is maintained at 120°C and does not rise any more. After about 1h of reaction, the acylated boiling product gradually changes from being mainly acetic anhydride to being mainly acetic acid. Due to the evaporation of the feed liquid and the removal of part of the heat, the feed liquid temperature and the gas phase temperature decrease. When the feed liquid temperature drops to 119°C (less than T and greater than T 1 ), nitrogen was introduced to a pressure of 50 kPa, and boiling was interrupted. During this period, the temperature was as low as T 1 When the heating is resumed, the reflux distributor 15 is set to a partial reflux state. The heating speed is adjusted by adjusting the heat medium speed or temperature, and the cooling speed is adjusted by adjusting the reflux speed. The reaction temperature is kept balanced until the reaction is finished. The acylation reaction is completed after 2 hours. During the process, the maximum temperature of the acylation reaction liquid is monitored to be 122°C, and the minimum temperature of the liquid after boiling before the reaction is finished is 117°C. The maximum temperature of the liquid is 2°C higher than T, and the minimum temperature of the liquid after boiling before the reaction is finished is 117°C higher than T. 1 1°C lower. The temperature of the reaction process is well controlled.

[0087] The reflux distributor 15 is set to the full extraction state, and the temperature is gradually increased to remove the by-product acetic acid, and the acetic acid produced in the acylation stage is retained. The material temperature is raised to 310°C within 3 hours for polycondensation reaction. When the stirring power reaches a predetermined value, the polymer melt is discharged from the casting head and water-cooled and pelletized.

[0088] In Experimental Example 2: After the feeding is completed, the heating is started, the heat medium temperature is 140°C, the reflux distributor 15 is set to a full reflux state, the heating is stopped when it reaches 130°C, and the vacuum is started at a vacuum rate of 20kPa / min. When the gas phase temperature reaches 100°C, the gas pressure of the gas phase is maintained at 62kPa (P is 64kPa). At this time, the feed liquid is boiling, and the feed liquid temperature in the kettle is 130°C and no longer rises. After about 1 hour, the acylated boiling product gradually changes from being mainly acetic anhydride to being mainly acetic acid. Due to the evaporation of the feed liquid and the removal of part of the heat, the feed liquid temperature and the gas phase temperature decrease. When the feed liquid temperature drops to 129.5°C (less than T and greater than T 1), nitrogen was introduced until the pressure in the kettle was 69 kPa, and boiling was interrupted. The reflux distributor 15 was adjusted to a partial reflux state, and the reflux rate was adjusted to maintain the balance of the reaction temperature. The acylation reaction was completed after 2 hours. During the process, the maximum temperature of the acylation reaction liquid was monitored to be 131°C, and the minimum temperature of the liquid after boiling before the end of the reaction was 129°C (not reaching T 1 ). The temperature of the reaction process is well controlled.

[0089] The reflux distributor 15 is set to a full extraction state, and the temperature is gradually increased to remove the by-product acetic acid, and the acetic acid produced in the acylation stage is retained. Then, the material temperature is increased to 310°C within 3 hours for polycondensation reaction. When the stirring power reaches a predetermined value, the polymer melt is discharged from the casting head and water-cooled and pelletized.

[0090] In Experimental Example 3: After the feeding is completed, the heating is started, the heat medium temperature is 140°C, the reflux distributor 15 is set to a full reflux state, the heating is stopped when it reaches 140°C, and the vacuum is started at a vacuum rate of 30kPa / min. When the gas phase temperature reaches 90°C, the gas pressure of the gas phase is maintained at 73kPa (P is 78kPa). At this time, the feed liquid is boiling, and the feed liquid temperature in the kettle is 140°C and no longer rises. After about 1 hour, the acylated boiling product gradually changes from being mainly acetic anhydride to being mainly acetic acid. Due to the evaporation of the feed liquid and the removal of part of the heat, the feed liquid temperature and the gas phase temperature decrease. When the feed liquid temperature drops to 139.5°C (less than T and greater than T 1 ), nitrogen was introduced until the pressure in the kettle was 88 kPa, and boiling was interrupted. The reflux distributor 15 was set to a partial reflux state to maintain the balance of the reaction temperature.

[0091] During the process, the maximum temperature of the acylation reaction liquid was monitored to be 142°C, and the minimum temperature of the liquid after boiling and before the end of the reaction was 139°C (not reaching T 1 ). The temperature of the reaction process is well controlled.

[0092] The reflux distributor 15 is set to a full extraction state, and the temperature is gradually increased to remove the by-product acetic acid, and the acetic acid produced in the acylation stage is retained. Then, the material temperature is increased to 310°C within 3 hours for polycondensation reaction. When the stirring power reaches a predetermined value, the polymer melt is discharged from the casting head and water-cooled and pelletized.

[0093] Three groups of comparative experiments were conducted, and the materials were the same as those in Experimental Examples 1 to 3. The structure of the reactor 1 was the same as that in Experimental Examples 1 to 3, but there was no exhaust system. That is, the heat was only dissipated by heat medium air cooling and the temperature was controlled by acetic acid reflux. Before the experiment began, the acetic acid collection tank was pre-filled with clean acetic acid, and the acetic acid collection tank was connected to the reactor 1 through an acetic acid reflux pump so that acetic acid could be input into the reactor 1 to cool the interior. The timing of heating and cooling was determined by the reading of the liquid temperature sensor 10.

[0094] Comparative Example 1: After the reactants were mixed and stirred evenly, the heat medium temperature was set to 120°C, and the acylation reaction was carried out under the protection of a nitrogen atmosphere. The feed liquid reached the specified temperature of 120°C in about 30 minutes. At this time, the heat medium heater was turned off and the heat medium air cooling was turned on. At the same time, the acetic acid reflux pump was turned on to return the clean acetic acid to the kettle for cooling. After cooling, the feed liquid temperature dropped to 119°C, and the cooling was stopped to maintain the reaction. After repeated regulation, the acylation reaction was completed in 2 hours. During the process, the maximum temperature of the acylation reaction feed liquid was monitored to be 125°C, and the minimum temperature of the feed liquid before the end of the reaction after boiling was 116°C. The temperature fluctuation amplitude, especially the over-temperature phenomenon of high temperature, is higher than that of Experimental Example 1.

[0095] After the acylation reaction is completed, the reflux distributor is set to the extraction state, and the temperature is gradually increased to remove the by-product acetic acid, and the acetic acid produced in the acylation stage is retained. Then the material temperature is raised to 310°C within 3 hours for polycondensation reaction. When the stirring power reaches the predetermined value, the polymer melt is discharged from the casting head and water-cooled pelletized.

[0096] Comparative Example 2: After the reactants were mixed and stirred evenly, the heat medium temperature was set to 130°C, and the acylation reaction was carried out under the protection of a nitrogen atmosphere. The feed liquid reached the specified temperature of 130°C in about 30 minutes. At this time, the heat medium heater was turned off and the heat medium air cooling was turned on. At the same time, the acetic acid reflux pump was turned on to return the clean acetic acid to the kettle for cooling. After cooling, the feed liquid temperature dropped to 129.5°C, and the cooling was stopped to maintain the reaction. After repeated regulation, the acylation reaction was completed in 2 hours. During the process, the maximum temperature of the acylation reaction feed liquid was monitored to be 136°C, and the minimum temperature of the feed liquid before the end of the reaction after boiling was 127°C. Temperature fluctuations, especially the over-temperature phenomenon of high temperature, are higher than those in Experimental Example 2.

[0097] After the acylation reaction is completed, the reflux distributor is set to the extraction state, and the temperature is gradually increased to remove the by-product acetic acid, and the acetic acid produced in the acylation stage is retained. Then the material temperature is raised to 310°C within 3 hours for polycondensation reaction. When the stirring power reaches the predetermined value, the polymer melt is discharged from the casting head and water-cooled pelletized.

[0098] Comparative Example 3: After the reactants were mixed and stirred evenly, the heat medium temperature was set to 140°C, and the acylation reaction was carried out under the protection of a nitrogen atmosphere. The feed liquid reached the specified temperature of 140°C in about 30 minutes. At this time, the heat medium heater was turned off and the heat medium air cooling was turned on. At the same time, the acetic acid reflux pump was turned on to return the clean acetic acid to the kettle for cooling. After cooling, the feed liquid temperature dropped to 139.5°C, and the cooling was stopped to maintain the reaction. After repeated regulation, the acylation reaction was completed in 2 hours. During the process, the maximum temperature of the acylation reaction feed liquid was monitored to be 145°C, and the minimum temperature of the feed liquid before the end of the reaction after boiling was 135°C. Temperature fluctuations, especially the over-temperature phenomenon of high temperature, are higher than those in Experimental Example 3.

[0099] After the acylation reaction is completed, the reflux distributor is set to the extraction state, and the temperature is gradually increased to remove the by-product acetic acid, and the acetic acid produced in the acylation stage is retained. Then the material temperature is raised to 310°C within 3 hours for polycondensation reaction. When the stirring power reaches the predetermined value, the polymer melt is discharged from the casting head and water-cooled pelletized.

[0100] The acetic acid samples of Experimental Examples 1 to 3 and Comparative Examples 1 to 3 were tested and evaluated. The phenol content was calculated by the following method: 10 g of the acetic acid sample was taken, 40 g of deionized water was added to dilute it, and then 0.1 mol / L of NaOH aqueous solution was added to adjust the pH to about 6, 3 ml of dichloromethane was added to extract twice, and the lower organic phase was taken for GC-MS testing, and the phenol content was obtained by the peak area.

[0101] The melting point test was performed on the final polymer products of Experimental Examples 1 to 3 and Comparative Examples 1 to 3. The melting point of the polymer was measured by DSC, and the temperature was raised from room temperature to 350°C at a heating rate of 20°C / min, and then the temperature was lowered to room temperature at a heating rate of 20°C / min after 3 minutes of heat preservation, and then the temperature was raised to 350°C at a heating rate of 20°C / min after 3 minutes of heat preservation, and the second DSC heating curve was obtained. The melting peak of this curve was selected as the melting point of the polymer. The results of the phenol content and melting point of the polymer are shown in Table 2.

[0102] Table 2 Determination results of different acetic acid samples and polymers

[0103]

[0104] As can be seen from Table 2, due to the large fluctuations in temperature control during the reaction process of Comparative Examples 1 to 3, especially the obvious "temperature runaway" phenomenon at high temperature, the acetic acid fraction obviously contains more phenol, and the performance of the polymer product is poor. However, the temperature control method of the present invention has less phenol content in the acetic acid fraction, better performance of the polymer product (high melting point liquid crystal polyester has higher strength and higher performance), more thorough acylation reaction and less impurities, which improves the quality of the subsequent polymer and is suitable for producing high-quality liquid crystal polyester.

Claims

1. A temperature control method for a thermotropic liquid crystal polyester synthesis reactor, wherein the synthesis reactor is a synthesis reactor for acylation reaction, characterized in that: The temperature control method comprises the following steps: S0 parameter settings: S01 Acylation reaction liquid parameter setting: set the target boiling temperature T of the liquid and the lower limit temperature T1 of the liquid, wherein T is 100°C to 150°C, and T1 is T-2°C to T-10°C; S02 Acylation reaction gas phase system parameter setting: Set the gas phase temperature threshold T- for gas phase system pressure regulation x and gas phase decompression range Py; the T- x is the gas phase temperature corresponding to the boiling of the feed liquid, x is 5℃~50℃; the P is the boiling temperature of the liquid and the gas phase temperature is T- x The corresponding gas phase pressure, y is 0~5kPa; S03 Nitrogen pressure control parameter setting for thermotropic liquid crystal polyester acylation reaction: Set nitrogen pressure control parameter P+ z , z is the pressure excess value, z 0~10kPa; S1 Acylation reaction and temperature control: S11: adding monomer, acylating agent and catalyst into the reaction kettle, stirring the materials, turning on heating, and turning on condensation reflux; S12: When the temperature of the liquid in the reactor reaches T, the heating is stopped and the reactor is evacuated; S13: The gas phase temperature in the reactor reaches T- x When, the pressure in the reactor is controlled to be Py; S14: When the temperature of the liquid in the reactor is less than T and greater than T1, stop pumping and introduce nitrogen to control the gas phase pressure in the reactor to P+ z Continue to react.

2. The temperature control method for a thermotropic liquid crystal polyester synthesis reactor according to claim 1, characterized in that: The T is 120°C to 140°C.

3. The temperature control method for a thermotropic liquid crystal polyester synthesis reactor according to claim 1, characterized in that: The monomer is selected from one or more of p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 4,4-biphenylene glycol, hydroquinone, p-aminophenol and derivatives thereof.

4. The temperature control method for a thermotropic liquid crystal polyester synthesis reactor according to claim 1, characterized in that: The acylating agent is selected from any one of acetic anhydride, propionic anhydride, butyric anhydride and valeric anhydride.

5. The temperature control method for a thermotropic liquid crystal polyester synthesis reactor according to claim 1, characterized in that: The catalyst is selected from one or more of metal acetates, 1-methylimidazole, 1-ethylimidazole, 1-propylimidazole, 1-butylimidazole, 1-hexylimidazole, 2-aminoimidazole, 3-aminopyridine, 4-aminopyridine, 3-dimethylaminopyridine, 4-dimethylaminopyridine, 3-pyrrolidinopyridine, 4-pyrrolidinopyridine, 2-aminopyrimidine, 3-aminopyrimidine, and 4-aminopyrimidine.

6. A synthetic reaction device applicable to the temperature control method of a thermotropic liquid crystal polyester synthesis reactor according to claim 1, comprising a reaction device body, a liquid heating component, a condensing medium transmission component, a gas phase pressure control component and a liquid collection tank; characterized in that: The condensing medium transmission component includes a steam inlet pipe, a condensing component and a reflux pipeline; the gas phase pressure control component includes a nitrogen replenishment system, a gas extraction system and a pressure transmitter.

7. The synthesis reaction device according to claim 6, characterized in that: The reaction device body includes a reactor; the liquid heating component includes a liquid temperature sensor and a heating controller; a gas phase temperature sensor is provided in the steam inlet pipe or on the upper part of the reactor; the nitrogen replenishment system is provided with a nitrogen regulating valve, and the exhaust system includes a vacuum pipeline, a vacuum regulating valve and a vacuum pump; the vacuum regulating valve is electrically connected to the liquid temperature sensor and the gas phase temperature sensor; the pressure transmitter is electrically connected to the nitrogen regulating valve and the vacuum regulating valve through a controller.

8. The synthesis reaction device according to claim 6, characterized in that: The condensing component includes a shell and tube condenser, a reflux distributor and a production pipeline; the shell and tube condenser receives gas from the steam inlet pipe and transports it to the reflux distributor, the reflux distributor transports the condensed fluid to the reflux pipeline and / or the production pipeline, and the production pipeline is connected to the liquid collection tank.

9. The synthesis reaction device according to claim 6, characterized in that: The condensing component includes a spray condenser, a secondary condenser, a temporary storage tank, an overflow pipeline, an electromagnetic three-way valve, a spray pump, a spray pipeline and a balance pipe; the spray condenser receives gas from the steam inlet pipe and transports it to the secondary condenser and the liquid collection tank respectively, and the two ends of the balance pipe are connected to the spray condenser and the liquid collection tank respectively; the secondary condenser transports the condensed fluid to the temporary storage tank; the lower part of the temporary storage tank is connected to the spray condenser through the spray pump and the spray pipeline, and the upper part of the temporary storage tank is connected to the reflux pipeline and the liquid collection tank through the overflow pipeline and the electromagnetic three-way valve.

10. The synthesis reaction device according to claim 6, characterized in that: A liquid seal is arranged on the return pipeline of the condensing component.

11. The synthesis reaction device according to claim 7, characterized in that: The vacuum pipeline includes a front vacuum pipeline, a vacuum buffer tank and a rear vacuum pipeline; the vacuum buffer tank is connected to the front vacuum pipeline and the rear vacuum pipeline respectively, the rear vacuum pipeline is connected to a vacuum pump; the front vacuum pipeline is connected to the reactor.

12. The synthesis reaction device according to claim 11, characterized in that: The vacuum regulating valve is installed on the front vacuum pipeline.

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