A continuous production system and continuous production process of isophthaloyl chloride

Abstract

The invention discloses a continuous production system and a continuous production process of isophthaloyl chloride, and belongs to the technical field of chemical synthesis. The continuous production system of isophthaloyl chloride comprises a first reactor, a microreactor and a second reactor connected in sequence; the microreactor is sequentially provided with a dispersed phase feeding module, a microsieve membrane, a microchannel plate, a continuous phase feeding module and a cover plate from bottom to top; wherein the microchannel plate is composed of a plurality of microchannels arranged in parallel, and is composed of one or more columns. Sulfur oxychloride is added in two times, and the added thionyl chloride enters the dispersed phase feeding module from the dispersed phase inlet as a dispersed phase, is dispersed into tiny droplets through the microsieve membrane above and enters the microchannel plate, and is quickly and evenly mixed with the continuous phase in the microchannel, thereby strengthening mixing and mass transfer, and at the same time, the heat exchange efficiency is improved by using microchannel enhanced heat exchange means, the reaction time is shortened, and the production capacity of a single reactor is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a continuous production system and a continuous production process of isophthaloyl chloride / terephthaloyl chloride. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] The traditional production process of isophthaloyl chloride is mainly based on the thionyl chloride method. Generally, isophthalic acid, excess thionyl chloride and catalyst are added to a reactor together, and then the temperature is raised and refluxed to react until the reaction is complete, and the excess thionyl chloride is evaporated. The thionyl chloride serves as both a reaction raw material and a solvent during the reaction. This method uses isophthalic acid and thionyl chloride as raw materials, and adds the catalyst to the reactor at the same time. Under the action of the catalyst, the crude isophthaloyl chloride is obtained by heating reaction, and hydrogen chloride and sulfur dioxide gas are generated at the same time. Finally, high-purity isophthaloyl chloride is obtained by distillation under high vacuum.

[0004] On the one hand, all the excess thionyl chloride is added to the reactor, the initial reaction temperature rise rate is slow, and the thionyl chloride reflux rate is large during the reaction, which reduces the reaction temperature, resulting in a slow reaction rate and high energy consumption. On the other hand, as the reaction proceeds, the generated hydrogen chloride and sulfur dioxide gas are extracted from the top of the reactor, the total volume of the raw materials continues to decrease, and after the reaction is completed, the reaction materials only account for half of the volume of the reactor, and the utilization rate of the reactor is not high. Summary of the invention

[0005] In order to solve the deficiencies of the prior art, the purpose of the present invention is to provide a continuous production system and continuous production process of isophthaloyl chloride. The production process provided by the production system adopts continuous production, has low energy consumption, high heat exchange efficiency, and improves the single-reactor capacity. The prepared isophthaloyl chloride has high yield and purity, and the product quality is relatively stable.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] On the one hand, the present application provides a continuous production system of isophthaloyl chloride / terephthaloyl chloride, comprising a first reactor, a microreactor and a second reactor connected in sequence; the first reactor is connected to one end of the microreactor through a pipeline, and the other end of the microreactor is connected to the second reactor through a pipeline; the microreactor is provided with a dispersed phase feed module, a microsieve membrane, a microchannel plate, a continuous phase feed module and a cover plate in sequence from bottom to top;

[0008] The microchannel plate is composed of a plurality of microchannels arranged in parallel, and is composed of one or more columns; the microreactor includes a continuous phase inlet, a dispersed phase inlet and a material outlet. Specifically, the continuous phase feed module is provided with a continuous phase inlet and a material outlet, respectively, and the dispersed phase feed module is provided with a dispersed phase inlet. The continuous phase enters the continuous phase feed module from the continuous phase inlet, and then enters the microchannel plate, while the dispersed phase enters the dispersed phase feed module from the dispersed phase inlet, is dispersed into tiny droplets through the micro-sieve membrane above, enters the microchannel plate, and mixes with the continuous phase in the microchannel, and finally the mixed liquid flows out from the material outlet.

[0009] The continuous phase feeding module contains multiple rows of material channels, including a feeding channel and a discharging channel; one end of the microchannel is connected to the feeding channel of the feeding module, and the other end is connected to the discharging channel of the feeding module, the feeding channel of the feeding module is connected to the continuous phase inlet, and the discharging channel of the feeding module is connected to the material outlet.

[0010] Furthermore, thionyl chloride is added twice, the first time it is added to the first reactor, and the second time it is added to the microreactor, so that the added thionyl chloride enters the microreactor as a dispersed phase. The material coming out of the bottom of the first reactor is used as a continuous phase and enters the continuous phase feeding module through the continuous phase inlet; the added thionyl chloride enters the dispersed phase feeding module through the dispersed phase inlet as a dispersed phase. Among them, the added thionyl chloride is dispersed into tiny droplets through the micro-sieve membrane above the dispersed phase feeding module, enters the microchannel, and mixes with the continuous phase in the microchannel, and finally flows out from the material outlet.

[0011] Furthermore, the micro-sieve membrane is a porous membrane with a pore size between 5 micrometers and 1.0 millimeters. The cross-sectional size of the micro-sieve membrane and the microreactor is the same, so that the micro-sieve membrane can be just embedded in the microreactor.

[0012] Furthermore, the thickness of the microchannel plate is 1-3 mm. The size of the microchannel plate is the same as the cross-sectional size of the microreactor.

[0013] The number of microchannels in each column can be adjusted according to actual conditions, for example, 1-50. In the embodiment of the present invention, there are 25 microchannels in each column. The interval between each microchannel in each column is 1-3 mm.

[0014] Each column is spaced a certain distance apart, and the spacing distance may also be adjusted according to actual conditions, for example, the spacing may be 5-20 mm. In the embodiment of the present invention, the spacing distance between each column is 10 mm.

[0015] Furthermore, one end of the feed channel is connected to the continuous phase inlet, and the other end is closed; one end of the discharge channel is connected to the material outlet, and the other end is closed.

[0016] The microchannel plate is fitted with the continuous phase feed module, and the continuous phase material is mixed with the dispersed phase from the feed channel through the microreactor and enters the discharge channel.

[0017] The feed channel and the discharge channel are slotted in the continuous phase feed module.

[0018] Furthermore, the continuous phase inlet is divided into a single or multiple feed branches, one feed branch is connected to a row of feed channels, and the number of rows of feed channels is the same as the number of feed branches at the continuous phase inlet; similarly, the material outlet is divided into a single or multiple discharge branches, one discharge branch is connected to a row of discharge channels, and the number of rows of discharge channels is the same as the number of discharge branches.

[0019] The microchannel plate covers the feed channel and the discharge channel on the continuous phase feed module, and the feed channel and the discharge channel are connected through microchannels. The microchannel plate is located below the continuous phase feed module. When the dispersed phase is dispersed into small droplets through the micro-sieve membrane and enters the microchannels in the microchannel plate, the continuous phase material enters from the continuous phase inlet, enters the feed channel in the continuous phase feed module through the feed branch, and then enters the microchannel below, so that the continuous phase and the dispersed phase are mixed in the microchannel plate, and finally the mixed liquid converges from the discharge channel through the discharge branch and flows out from the material outlet.

[0020] The specific number of columns of microchannels can be adjusted according to actual conditions.

[0021] Preferably, when the number of microchannel columns is four, the continuous phase feed module contains five columns of material channels, including three columns of feed channels and two columns of discharge channels, that is, three inlets and two outlets. One end of the three columns of feed channels is connected to the inlet of the continuous phase, and the other end is closed and not connected to the material outlet of the microreactor. One end of the remaining two columns of feed channels is connected to the material outlet of the microreactor, and the other end is closed and not connected to the end near the continuous phase inlet. At this time, the continuous phase inlet is divided into three feed branches and connected to the three columns of feed channels. The discharge channel is divided into two discharge branches and connected to the two columns of discharge channels, which are merged through the two discharge branches and connected to the material outlet.

[0022] Preferably, when the number of microchannel columns is 1, the continuous phase feed module contains two columns of material channels, including 1 column of feed channels and 1 column of discharge channels, that is, one inlet and one outlet. At this time, the continuous phase inlet is 1 feed branch, which is connected to the feed channel. The discharge channel is 1 discharge branch, which is connected to the discharge channel, and the discharge branch is connected to the material outlet.

[0023] The relationship between the number of microchannel columns and the number of material channel columns is as follows:

[0024] When the number of microchannel columns is 1, it contains 2 columns of material channels. At this time, the number of microchannel columns = the number of feed channel columns = the number of discharge channel columns = 1;

[0025] When the number of microchannel columns is 2, there are 3 columns of material channels. At this time, the number of microchannel columns = the number of feed channel columns = 2, the number of discharge channel columns = 1, or the number of microchannel columns = the discharge channel = 2, the number of feed channel columns = 1;

[0026] When the number of microchannel columns is 3, it contains 4 columns of material channels. At this time, the number of feed channel columns = the number of discharge channel columns = 2;

[0027] When the number of microchannel columns is 4, there are 5 columns of material channels. At this time, the number of feed channel columns = 3, the number of discharge channel columns = 2, or the number of feed channel columns = 2, the number of discharge channel columns = 3;

[0028] When the number of microchannel columns is 5, there are 6 columns of material channels. At this time, the number of feed channel columns = the number of discharge channel columns = 3;

[0029] …

[0030] Therefore, when the number of microchannel columns is n, there are (n+1) columns of material channels. At this time:

[0031] When n is an odd number, the number of feed channel columns = the number of discharge channel columns = ;

[0032] When n is an even number, the number of feed channel columns = , discharge channel = +1; or discharge channel column = ; Number of feed channel columns = +1;

[0033] Wherein, n≥1, and n is an integer.

[0034] By setting the number of microchannel columns and material channel columns as mentioned above, the dispersed phase is dispersed into small droplets through the microporous sieve membrane and enters the microchannel, while the continuous phase enters the microchannel through the feed channel, so that in the microchannel, the dispersed phase in a smaller droplet state and the continuous phase can be more fully mixed.

[0035] Furthermore, the continuous phase feed module is provided with a heat exchange module, including a heat exchange pipe. The heat exchange pipe is located above the feed channel and the discharge channel. A steam inlet is provided at one end of the heat exchange pipe, and a steam outlet is provided at the other end. The steam inlet and the steam outlet can be arranged on the same side or on different sides. The heat exchange pipe is a microchannel heat exchanger. The microchannel heat exchanger can be a heat exchanger in the prior art without specific limitation. A coiled tube heat exchanger can be used in the embodiment of the present invention.

[0036] Furthermore, the mixing tank is also included, and the mixing tank is connected to the first reaction kettle through a pipeline. The top of the mixing tank is provided with a catalyst addition port and an isophthaloyl chloride addition port, and is also provided with a pipeline connected to a thionyl chloride recovery tank, and a new thionyl chloride addition port is provided on the pipeline.

[0037] Furthermore, it also includes a first reactor condenser and a second reactor condenser. The first reactor condenser is connected to the top of the first reactor, and the second reactor condenser is connected to the top of the second reactor. Therefore, the steam from the top of the reactor is processed by the condenser and then flows back to the reactor, and the tail gas is also discharged. The tail gas contains SO2, HCl, etc.

[0038] Furthermore, the first reactor and the second reactor are provided with a stirring device, which can be any stirring device in the prior art, such as a stirring shaft.

[0039] Furthermore, it also includes a first reactor pump and a second reactor pump. The first reactor pump is arranged on the pipeline connecting the first reactor and the microreactor, and the second reactor pump is arranged on the pipeline connecting the second reactor and the atmospheric pressure desolventizing tower.

[0040] Furthermore, the invention also includes a thionyl chloride separation device and a thionyl chloride recovery tank, wherein the thionyl chloride separation device includes a normal pressure desolventizing tower and a negative pressure desolventizing tower. The second reactor, the normal pressure desolventizing tower and the negative pressure desolventizing tower are sequentially connected through pipelines.

[0041] The thionyl chloride recovery tank is connected to the condenser above the atmospheric pressure desolventizing tower through a pipeline, and is also connected to the condenser above the negative pressure desolventizing tower through a pipeline, and the unreacted thionyl chloride separated from the atmospheric pressure desolventizing tower and the negative pressure desolventizing tower is recovered through the two pipelines. The bottom of the thionyl chloride recovery tank is connected to the mixing tank through a pipeline, and a thionyl chloride recovery tank booster pump is arranged on the pipeline, so as to realize the reuse of the recovered thionyl chloride.

[0042] The pipeline coming out from the bottom of the atmospheric pressure desolventizing tower is connected to the atmospheric pressure desolventizing tower pump. The other end of the atmospheric pressure desolventizing tower pump has two connecting pipelines, one connecting pipeline is connected to the middle part of the negative pressure desolventizing tower, and the other connecting pipeline is connected to one end of the reboiler below the atmospheric pressure desolventizing tower, and then the other end of the reboiler below the atmospheric pressure desolventizing tower is connected to the atmospheric pressure desolventizing tower.

[0043] The pipeline coming out from the bottom of the negative pressure desolventizing tower is connected to the negative pressure desolventizing tower pump. The other end of the normal pressure desolventizing tower pump has two connecting pipelines, one connecting pipeline is connected to the distillation tower, and the other connecting pipeline is connected to one end of the reboiler below the negative pressure desolventizing tower. The reboiler is divided into two pipelines, one pipeline is connected to the negative pressure desolventizing tower, and the other pipeline is connected to the hot water tank.

[0044] The top of the atmospheric pressure desolventizing tower is connected to one end of the condenser above the atmospheric pressure desolventizing tower through a pipeline. The other end of the condenser above the atmospheric pressure desolventizing tower has two connecting pipelines, one connecting pipeline is connected to the thionyl chloride recovery tank, and the other connecting pipeline is connected to the top of the atmospheric pressure desolventizing tower.

[0045] The top of the negative pressure desolventizing tower is connected to one end of the condenser above the negative pressure desolventizing tower through a pipeline. The other end of the condenser above the negative pressure desolventizing tower has two connecting pipelines, one connecting pipeline is connected to the top of the negative pressure desolventizing tower, and the other connecting pipeline is connected to the pipeline of the other end of the condenser above the normal pressure desolventizing tower and the thionyl chloride recovery tank, so that the thionyl chloride separated in the normal pressure desolventizing tower and the negative pressure desolventizing tower are collected and transported to the thionyl chloride recovery tank.

[0046] The crude isophthaloyl chloride / terephthaloyl chloride from the reflux reaction of the second reactor enters the middle of the atmospheric pressure desolventizing tower after being pressurized by the second reactor pump. After the crude isophthaloyl chloride / terephthaloyl chloride is processed by the atmospheric pressure desolventizing tower, the recovered unreacted thionyl chloride comes out from the top of the tower, and after being condensed by the condenser above the atmospheric pressure desolventizing tower, most of it enters the thionyl chloride recovery tank, and a small part of it flows back to the top of the atmospheric pressure desolventizing tower, and the reflux ratio is 0.1~1. The reflux here, on the one hand, provides liquid phase reflux on the tower plate to achieve the purpose of full contact, heat transfer and mass transfer between the vapor and liquid phases, and on the other hand, takes away the residual heat in the tower to maintain the thermal equilibrium state of the whole tower, so as to control the product quality.

[0047] After being processed in the atmospheric pressure desolventizing tower, the crude isophthaloyl chloride / terephthaloyl chloride coming out from the bottom of the atmospheric pressure desolventizing tower is pressurized by a pump, part of which enters the negative pressure desolventizing tower, and part of which returns to the atmospheric pressure desolventizing tower after being heated by a reboiler, with a circulation and extraction ratio of 3 to 10. The function of the tower bottom material circulation here is that, on the one hand, the reboiler provides the necessary heat for the tower to maintain the boiling and evaporation of the liquid in the tower, thereby realizing the separation and purification of the liquid, and on the other hand, the reboiler helps maintain the pressure balance in the tower by heating and vaporizing the liquid, ensuring safe and stable operation in the tower.

[0048] The crude isophthaloyl chloride / terephthaloyl chloride entering the negative pressure desolventizing tower is treated by the negative pressure desolventizing tower, and the recovered unreacted thionyl chloride comes out from the top of the tower. After condensation in the condenser above the negative pressure desolventizing tower, part of it enters the thionyl chloride recovery tank, and part of it refluxes to the top of the negative pressure desolventizing tower, with a reflux ratio of 0.5 to 1.5. After being treated by the negative pressure desolventizing tower, the crude isophthaloyl chloride / terephthaloyl chloride coming out from the bottom of the negative pressure desolventizing tower is pressurized by a pump, part of it enters the distillation tower, and part of it is heated by a reboiler and refluxed to the negative pressure desolventizing tower, with a circulation and extraction ratio of 1 to 3.

[0049] Furthermore, it also includes a hot water tank. The reboiler below the negative pressure desolventizing tower, the hot water tank, the hot water tank booster pump, and the condenser above the distillation tower are connected in sequence through pipelines. The reboiler below the negative pressure desolventizing tower is connected to one end of the hot water tank, the steam releases heat and condenses in the reboiler, and the condensate returns to the hot water tank. The other end of the hot water tank is connected to the condenser above the distillation tower through the hot water tank booster pump, the hot water absorbs heat and vaporizes in the condenser, and the steam is used to heat the reboiler of the negative pressure desolventizing tower. By setting appropriate parameters (tower top extraction and reflux ratio), the heat load of the condenser at the top of the distillation tower and the heat load of the reboiler in the kettle of the negative pressure desolventizing tower are matched, the two towers achieve double-effect distillation, and energy is integrated.

[0050] Furthermore, the continuous production system also includes a distillation tower and an evaporator, and the negative pressure desolventizing tower, the distillation tower and the evaporator are connected in sequence through pipelines.

[0051] The distillation tower has a pipeline coming out of the bottom connected to a distillation tower pump, and the other end of the distillation tower pump has two connecting pipelines, one connecting pipeline is connected to the top side of the evaporator, and the other connecting pipeline is connected to one end of the reboiler below the distillation tower, and then the other end of the reboiler below the distillation tower is connected to the distillation tower.

[0052] The top of the distillation tower is connected to one end of the condenser above the distillation tower through a pipeline, and the other end of the condenser above the distillation tower has two connecting pipelines, one connecting pipeline is connected to the negative pressure desolventizing tower to further separate thionyl chloride, and the other connecting pipeline is connected to the top of the distillation tower; one side of the condenser cooling medium above the distillation tower is also connected to the reboiler below the negative pressure desolventizing tower, and by setting appropriate parameters, the heat load of the condenser at the top of the distillation tower and the heat load of the reboiler in the kettle of the negative pressure desolventizing tower are matched, and the two towers realize double-effect distillation, and energy is integrated. One side of the distillation tower is also provided with an isophthaloyl chloride product discharge port.

[0053] In the evaporator, one side of the top of the evaporator is connected to the pipeline coming out of the distillation tower pump, so that the material in the distillation tower kettle enters the evaporator, the bottom of the evaporator is the heavy component discharge port, and the other side of the top of the evaporator is connected to one end of the condenser above the light component recovery tank, and the bottom of the light component recovery tank is connected to the distillation tower.

[0054] On the other hand, the present application also provides a continuous production process of isophthaloyl chloride / terephthaloyl chloride, which utilizes the above-mentioned continuous production system of isophthaloyl chloride / terephthaloyl chloride, comprising the following steps:

[0055] (1) isophthalic acid / terephthalic acid, thionyl chloride and a catalyst are uniformly mixed in a mixing tank, and the materials in the mixing tank are fed into a first reactor for reaction;

[0056] (2) the reaction product of step (1) enters the microreactor through the continuous phase inlet, and a set amount of thionyl chloride is added to the microreactor through the dispersed phase inlet, the added thionyl chloride is dispersed into tiny droplets through the micro-mesh membrane, enters the microchannel, mixes with the continuous phase, and reacts, and the mixed liquid flows out from the material outlet;

[0057] (3) The product at the outlet of the microreactor enters the second reactor for reaction to obtain crude isophthaloyl chloride / terephthaloyl chloride;

[0058] (4) The crude isophthaloyl chloride / terephthaloyl chloride product enters a normal pressure desolventizing tower and a negative pressure desolventizing tower in turn, and thionyl chloride in the crude isophthaloyl chloride / terephthaloyl chloride product is separated and flows into a thionyl chloride recovery tank from the top of the tower;

[0059] (5) The materials in the bottom of the negative pressure desolventizing tower are fed into the product distillation tower to obtain qualified isophthaloyl / terephthaloyl chloride.

[0060] Furthermore, in the step (1), the molar ratio of thionyl chloride to isophthalic acid is (1-3):1; the amount of catalyst used is 1-2% of the mass of isophthalic acid; and the catalyst is N,N-dimethylformamide (DMF) or pyridine.

[0061] The sources of thionyl chloride include new thionyl chloride and recycled thionyl chloride. Recycled thionyl chloride is used preferentially, with new thionyl chloride used as a supplement.

[0062] Furthermore, in the step (1), in the first reactor, the reaction conditions are as follows: the reaction pressure is controlled to be 0-25 kPa, and the reaction temperature is controlled to be 60-100°C.

[0063] Furthermore, in the step (2), in the microreactor, the molar ratio of thionyl chloride to isophthalic acid / terephthalic acid is (1-3):1.

[0064] Furthermore, in the step (3), the reaction conditions in the second reactor are as follows: the reaction pressure is controlled to be 0-25 kPa, and the reaction temperature is controlled to be 60-100°C.

[0065] Furthermore, in the normal pressure desolventizing tower, the pressure is normal pressure, and the tower bottom temperature is 100-130° C. In the negative pressure desolventizing tower, the vacuum degree is 80-100 kPa, and the tower bottom temperature is 100-130° C.

[0066] Furthermore, in the distillation tower, the vacuum degree is 95-100 kPa, the tower top temperature is 130-150°C, and the tower bottom temperature is 150-170°C.

[0067] Furthermore, the isophthaloyl chloride / terephthaloyl chloride product is taken out from the side line of the distillation tower, and the thionyl chloride content in the top product is 5% to 20%, which enters the negative pressure desolventizing tower for further separation.

[0068] One or some of the above technical solutions have the following advantages or beneficial effects:

[0069] 1. Sulfonyl chloride is added to the reaction system in two parts. The first part is added to the first reactor at the beginning of the reaction. The remaining thionyl chloride is used as a dispersed phase and dispersed into droplets in the microreactor through micro-sieve holes before being added to the reaction system. Sulfonyl chloride is added in two batches to avoid a large amount of thionyl chloride reflux in the early stage of the reaction, which reduces the reaction temperature and inhibits the activity of the catalyst. At the same time, thionyl chloride is directly mixed with the outlet product of the first reactor in the microreactor quickly and evenly, which strengthens the mixing and mass transfer. At the same time, the microchannel enhanced heat exchange method is used to improve the heat exchange efficiency, shorten the reaction time, and increase the production capacity of a single reactor.

[0070] 2. The recovery of thionyl chloride from the crude acyl chloride is separated and purified by first desolventizing at normal pressure and then desolventizing at negative pressure. Desolventizing at normal pressure results in less solvent loss and low separation energy consumption; the crude product after desolventizing at normal pressure has an increased content of heavy components, and desolventizing at negative pressure is used to avoid product decomposition caused by excessively high tower bottom temperature. By setting appropriate parameters to ensure that the heat load of the top condenser of the distillation tower matches the heat load of the reboiler in the bottom of the negative pressure desolventizing tower, the two towers achieve double-effect distillation, and energy is integrated and utilized.

[0071] 3. The present invention utilizes a production process provided by a continuous production system of isophthaloyl chloride, which not only retains the characteristics of high yield and low impurity content of the product of the thionyl chloride method, but also realizes continuous production and improves the stability of product quality; the isophthaloyl chloride produced has a purity of more than 99.9% and a yield of more than 99.0%. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0073] Figure 1 This is a flow chart of the continuous production process of isophthaloyl chloride in Example 1 of the present invention;

[0074] Figure 2 The mixing principle diagram of the microreactor in Example 1 of the present invention;

[0075] Figure 3 This is a schematic diagram of the assembly of the microreactor in Example 1 of the present invention;

[0076] Figure 4 for Figure 3Schematic diagram of a continuous phase feeding module of a microreactor in the continuous phase feeding module; wherein (A) is a schematic diagram of the structure of each inlet and outlet position in the continuous phase feeding module; (B) is a schematic diagram of the heat exchange pipeline in the heat exchange module; (C) is a schematic diagram of the position of the material channel in the continuous phase feeding module and the steam channel in the heat exchange module, (a) is a general schematic diagram of the steam channel and the material channel, (b) is a separate schematic diagram of the material channel, and (c) is a separate schematic diagram of the steam channel; (D) is a schematic diagram of the connection relationship between the feed channel and the discharge channel inside the continuous phase feeding module;

[0077] Figure 5 Schematic diagram of a microchannel plate in a microreactor according to Example 1 of the present invention;

[0078] Figure 6 This is a schematic diagram of a dispersed phase feeding module in a microreactor according to Example 1 of the present invention;

[0079] Figure 7 This is a schematic diagram of the material channel of the continuous phase feeding module and the material flow in the continuous phase feeding module and the microchannel in the microreactor of Example 1 of the present invention; wherein the arrow indicates the material flow direction;

[0080] Among them, 1-mixing tank; 2-first reactor; 3-microreactor; 4-second reactor; 5-normal pressure desolventizing tower; 6-negative pressure desolventizing tower; 7-thionyl chloride recovery tank; 8-hot water tank; 9-distillation tower; 10-evaporator; 11-light component recovery tank; 12-first reactor condenser; 13-second reactor condenser; 14-first reactor pump; 15-second reactor pump; 16-normal pressure desolventizing tower pump; 17-negative pressure desolventizing tower pump; 18-thionyl chloride recovery tank booster pump; 19-hot water tank booster pump; 20-distillation tower pump; 21-catalyst addition port; 2 2-inlet for isophthaloyl chloride / terephthaloyl chloride; 23-addition of new thionyl chloride; 24-discharge outlet for isophthaloyl chloride / terephthaloyl chloride product; 25-discharge outlet for heavy components; 26-tail gas; 31-dispersed phase feed module; 32-microsieve membrane; 33-microchannel plate; 34-continuous phase feed module; 35-cover plate; 311-dispersed phase inlet; 331-microchannel; 341-continuous phase inlet; 342-material outlet; 343-steam inlet; 344-steam outlet; 345-feed channel; 346-discharge channel; 347-feed branch; 348-discharge branch. DETAILED DESCRIPTION

[0081] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0082] Example 1

[0083] The continuous production system of isophthaloyl chloride in this embodiment 1 is referred to as Figure 1 , including a first reactor, a microreactor and a second reactor connected in sequence; the first reactor is connected to the microreactor through a pipeline, and the microreactor is connected to the second reactor through a pipeline; the microreactor is provided with a dispersed phase feed module, a microsieve membrane, a microchannel plate, a continuous phase feed module and a cover plate in sequence from bottom to top. The microreactor includes a continuous phase inlet, a dispersed phase inlet and a material outlet.

[0084] Specifically, the continuous phase feed module is provided with a continuous phase inlet and a material outlet, respectively, and the dispersed phase feed module is provided with a dispersed phase inlet. The material coming out of the bottom of the first reactor enters the microreactor through the continuous phase inlet as the continuous phase; the added thionyl chloride enters the microreactor through the dispersed phase inlet as the dispersed phase. The added thionyl chloride is dispersed into tiny droplets through the micro-mesh membrane above the dispersed phase feed module, enters the microchannel, and mixes with the material from the bottom of the first reactor in the microchannel, and finally flows out from the material outlet of the microreactor.

[0085] The dispersed phase feed module has a dispersed phase inlet on one side and a micro-sieve membrane on the upper end. The micro-sieve membrane can be a porous membrane with a pore size of 0.5 mm. The cross-sectional size of the micro-sieve membrane and the microreactor is the same, so that the micro-sieve membrane is just embedded in the microreactor.

[0086] In this example, the dispersed phase inlet and the continuous phase inlet are on adjacent sides (at a 90° angle). In practice, the dispersed phase opening can be adjusted according to the installation situation, and can be on the same side, adjacent side, or opposite side.

[0087] The thickness of the microchannel plate is 3mm. The microchannel plate fits the continuous phase feed module, and the continuous phase material is fully mixed with the dispersed phase through the feed channel through the microreactor and enters the discharge channel. The size of the microchannel plate is the same as the cross-sectional size of the microreactor.

[0088] The microchannel plate is composed of multiple columns with multiple microchannels arranged side by side. One end of the microchannel is connected to the feed channel of the feed module, and the other end is connected to the discharge channel of the feed module. The feed channel of the feed module is connected to the continuous phase inlet of the microreactor, and the discharge channel of the feed module is connected to the material outlet of the microreactor. There are 25 microchannels in each column. Each microchannel in each column is 2mm apart. Each column is separated by a certain distance, and the distance between each column is 10mm.

[0089] The continuous phase feeding module contains multiple columns of material channels, including feed channels and discharge channels; one end of the feed channel is connected to the continuous phase inlet and the other end is closed, and one end of the discharge channel is connected to the material outlet and the other end is closed. The feed channel and the discharge channel are slotted in the continuous phase feeding module. The continuous phase inlet is divided into multiple feed branches, one feed branch is connected to a column of feed channels, and the number of columns of feed channels is the same as the number of feed branches of the continuous phase inlet; similarly, the material outlet is divided into multiple discharge branches, one discharge branch is connected to a column of feed channels, and the number of columns of discharge channels is the same as the number of discharge branches.

[0090] In the present embodiment, the number of microchannel columns is an even number, n=4, that is, there are four columns of microchannels, then the feed module contains five columns of material channels, which can be set to 3 columns of feed channels and 2 columns of discharge channels, that is, three inlets and two outlets, or 2 columns of feed channels and 3 columns of discharge channels, that is, two inlets and three outlets. In order to further achieve sufficient mixing of the continuous phase and the dispersed phase, three inlets and two outlets are selected in the present embodiment. Specifically, one end of the three columns of feed channels is connected to the inlet of the continuous phase through a feed branch, and the other end is not connected to the material outlet of the microreactor, and the remaining two columns of feed channels are not connected to the end close to the continuous phase inlet, and the other end is connected to the material outlet of the microreactor through a discharge branch. At this time, the continuous phase inlet is connected to the 3 columns of feed channels through 3 feed branches. The discharge channel is divided into 2 discharge branches connected to the 2 columns of feed channels, which are merged through 2 discharge branches and connected to the material outlet, such as Figure 7 shown.

[0091] The microchannel plate covers the feed channel and the discharge channel on the continuous phase feed module, and the feed channel and the discharge channel are connected through microchannels. The microchannel plate is located below the continuous phase feed module. When the dispersed phase is dispersed into small droplets through the micro-sieve membrane and enters the microchannels in the microchannel plate, the continuous phase material enters from the continuous phase inlet, enters the feed channel in the continuous phase feed module through the feed branch, and then enters the microchannel below, so that the continuous phase and the dispersed phase are mixed in the microchannel plate, and finally the mixed liquid converges from the discharge channel through the discharge branch and flows out from the material outlet.

[0092] In other words, the material from the first reactor as the continuous phase passes through the continuous phase inlet through the feed branch into the feed channel in the continuous phase feed module, and then enters the microchannel of the microchannel plate. When the added thionyl chloride as the dispersed phase passes through the microsieve membrane from the dispersed phase feed module into the microchannel in the microchannel plate, the two are rapidly mixed and mass transferred. In addition, because of the heat exchange pipe provided above the material channel, the heat transfer efficiency is further improved, the heat load required for the reaction is met, and the reaction rate is increased. Furthermore, the mixed material enters the discharge channel in the continuous phase feed module, converges to the material outlet through the discharge branch, and enters the next stage.

[0093] The continuous phase feeding module is provided with a continuous phase material inlet and a microreactor material outlet, and the continuous phase material inlet and the microreactor material outlet are arranged on opposite sides respectively.

[0094] like Figure 3 and Figure 4 (B) Figure 4 As shown in (C), the continuous phase feed module is also provided with a heat exchange module, including a heat exchange pipe. The heat exchange pipe is located above the material channel (feed channel and discharge channel). A steam inlet is provided at one end of the heat exchange pipe, and a steam outlet is provided at the other end. The steam inlet and the steam outlet are arranged on the same side, and are arranged on the adjacent sides of the continuous phase material inlet and the microreactor material outlet. The heat exchange pipe is a microchannel heat exchanger, and the style of the microchannel heat exchanger can be a coil heat exchanger. The steam temperature is about 130°C, and the materials react after mixing in the microreactor.

[0095] The steam channel is above the continuous phase feeding module, and the material channel is below the continuous phase feeding module.

[0096] The continuous production system also includes a mixing tank, which is connected to the first reaction kettle through a pipeline. The top of the mixing tank is provided with a catalyst addition port and an isophthaloyl chloride addition port, and is also provided with a pipeline connected to a thionyl chloride recovery tank, and a new thionyl chloride addition port is provided on the pipeline.

[0097] The continuous production system also includes a first reactor condenser and a second reactor condenser. The first reactor condenser is connected to the top of the first reactor, and the second reactor condenser is connected to the top of the second reactor. Therefore, the steam from the top of the reactor is processed by the condenser and then flows back to the reactor, and the tail gas is also discharged. The tail gas contains SO2, HCl, etc.

[0098] In the first reaction kettle condenser and the second reaction kettle condenser, a plurality of condensing tubes can be arranged and connected in parallel. In this embodiment, two condensing tubes can be arranged.

[0099] The first reactor and the second reactor are provided with a stirring device, which can be a stirring device in the prior art, such as a stirring shaft.

[0100] The continuous production system also includes a first reactor pump and a second reactor pump. The first reactor pump is arranged on a pipeline connecting the first reactor and the microreactor, and the second reactor pump is arranged on a pipeline connecting the second reactor and the atmospheric pressure desolventizing tower.

[0101] The continuous production system also includes a thionyl chloride separation device, which includes a normal pressure desolventizing tower and a negative pressure desolventizing tower, which are connected in sequence.

[0102] The pipeline coming out from the bottom of the normal pressure desolventizing tower is connected to the normal pressure desolventizing tower pump, and the other end of the normal pressure desolventizing tower pump has two connecting pipelines, one connecting pipeline is connected to the middle of the negative pressure desolventizing tower, and the other connecting pipeline is connected to one end of the reboiler below the normal pressure desolventizing tower, and then the other end of the reboiler below the normal pressure desolventizing tower is connected to the normal pressure desolventizing tower. The pipeline coming out from the bottom of the negative pressure desolventizing tower is connected to the negative pressure desolventizing tower pump, and the other end of the normal pressure desolventizing tower pump has two connecting pipelines, one connecting pipeline is connected to the distillation tower, and the other connecting pipeline is connected to one end of the reboiler below the negative pressure desolventizing tower. The reboiler is divided into two pipelines, one pipeline is connected to the negative pressure desolventizing tower, and the other pipeline is connected to the hot water tank.

[0103] The top of the atmospheric pressure desolventizing tower is connected to one end of the condenser above the atmospheric pressure desolventizing tower through a pipeline, and the other end of the condenser above the atmospheric pressure desolventizing tower has two connecting pipelines, one connecting pipeline is connected to the thionyl chloride recovery tank, and the other connecting pipeline is connected to the top of the atmospheric pressure desolventizing tower. The top of the negative pressure desolventizing tower is connected to one end of the condenser above the negative pressure desolventizing tower through a pipeline, and the other end of the condenser above the negative pressure desolventizing tower has two connecting pipelines, one connecting pipeline is connected to the top of the negative pressure desolventizing tower, and the other connecting pipeline is connected to the other end of the condenser above the atmospheric pressure desolventizing tower and the pipeline of the thionyl chloride recovery tank, and the separated thionyl chloride in the atmospheric pressure desolventizing tower and the negative pressure desolventizing tower are collected and transported to the thionyl chloride recovery tank.

[0104] The crude isophthaloyl chloride produced by the reflux reaction of the second reactor enters the middle part of the atmospheric pressure desolventizing tower after being pressurized by the second reactor pump. After the crude isophthaloyl chloride is treated by the atmospheric pressure desolventizing tower, the unreacted thionyl chloride is recovered from the top of the tower, and after being condensed by the condenser above the atmospheric pressure desolventizing tower, most of it enters the thionyl chloride recovery tank, and a small part is refluxed to the top of the atmospheric pressure desolventizing tower, and the reflux ratio is 0.4; after being treated by the atmospheric pressure desolventizing tower, the crude isophthaloyl chloride coming out from the bottom of the atmospheric pressure desolventizing tower is pressurized by the pump, and part of it enters the negative pressure desolventizing tower, and part of it returns to the atmospheric pressure desolventizing tower after being heated by the reboiler, and the circulation and extraction ratio is 6.5.

[0105] The crude isophthaloyl chloride / terephthaloyl chloride entering the negative pressure desolventizing tower is treated by the negative pressure desolventizing tower, and the recovered unreacted thionyl chloride comes out from the top of the tower. After condensation in the condenser above the negative pressure desolventizing tower, part of it enters the thionyl chloride recovery tank, and part of it flows back to the top of the negative pressure desolventizing tower, and the reflux ratio is 1; after being treated by the negative pressure desolventizing tower, the crude isophthaloyl chloride / terephthaloyl chloride coming out from the bottom of the negative pressure desolventizing tower is pressurized by a pump, and part of it enters the distillation tower, and part of it returns to the negative pressure desolventizing tower after being heated in a reboiler, and the circulation and extraction ratio is 1.4.

[0106] The continuous production system includes a thionyl chloride recovery tank, which is connected to the condenser above the atmospheric pressure desolventizing tower through a pipeline, and is also connected to the condenser above the negative pressure desolventizing tower through a pipeline, and the unreacted thionyl chloride separated from the atmospheric pressure desolventizing tower and the negative pressure desolventizing tower is recovered through the above two pipelines. The bottom of the thionyl chloride recovery tank is connected to the mixing tank through a pipeline, and a thionyl chloride recovery tank pressure pump is arranged on the pipeline, so as to realize the reuse of the recovered thionyl chloride.

[0107] Among them, since thionyl chloride is added twice, whether it is the thionyl chloride added to the first reactor for the first time or the thionyl chloride added in the microreactor later, the thionyl chloride source includes new thionyl chloride and recycled thionyl chloride, and recycled thionyl chloride is preferably used, and new thionyl chloride is added as a supplement. The added thionyl chloride is added to the microreactor through the dispersed phase inlet, and its specific source route is as follows: Figure 1 Not given in .

[0108] The continuous production system also includes a hot water tank. The reboiler below the negative pressure desolventizing tower, the hot water tank, the hot water tank booster pump, and the condenser above the distillation tower are connected in sequence through pipelines. The reboiler below the negative pressure desolventizing tower is connected to the hot water tank, the steam releases heat and condenses in the reboiler, and the condensate returns to the hot water tank. The bottom of the hot water tank is connected to the condenser above the distillation tower through the hot water tank booster pump, the hot water absorbs heat and vaporizes in the condenser, and the steam is used to heat the reboiler of the negative pressure desolventizing tower. By setting appropriate parameters (the reflux ratio of the distillation tower is 0.3, and the top extraction feed ratio is 0.21), the heat load of the condenser at the top of the distillation tower and the heat load of the reboiler in the bottom of the negative pressure desolventizing tower are matched, and the two towers achieve double-effect distillation, and energy is integrated.

[0109] The continuous production system also includes a distillation tower and an evaporator. The negative pressure desolventizing tower, the distillation tower and the evaporator are connected in sequence through pipelines.

[0110] The pipeline coming out of the bottom of the distillation tower is connected to the distillation tower pump. The other end of the distillation tower pump has two connecting pipelines, one connecting pipeline is connected to the top side of the evaporator, and the other connecting pipeline is connected to one end of the reboiler below the distillation tower, and then the other end of the reboiler below the distillation tower is connected to the distillation tower.

[0111] The top of the distillation tower is connected to one end of the condenser above the distillation tower through a pipeline. The other end of the condenser above the distillation tower has two connecting pipelines, one connecting pipeline is connected to the negative pressure desolventizing tower to further separate thionyl chloride, and the other connecting pipeline is connected to the top of the distillation tower. In addition, one side of the cooling medium of the condenser above the distillation tower is also connected to the reboiler below the negative pressure desolventizing tower. By setting appropriate parameters, the heat load of the condenser at the top of the distillation tower and the heat load of the reboiler in the kettle of the negative pressure desolventizing tower are matched, and the two towers realize double-effect distillation, and energy is integrated.

[0112] One side of the distillation tower is also provided with an outlet for isophthaloyl chloride product.

[0113] In the evaporator, one side of the top of the evaporator is connected to the pipeline coming out of the distillation tower pump, so that the materials in the distillation tower kettle enter the evaporator, and the bottom of the evaporator is the heavy component discharge port; the other side of the top of the evaporator is connected to one end of the condenser above the light component recovery tank, and the bottom of the light component recovery tank is connected to the distillation tower.

[0114] Example 2

[0115] The continuous production system of isophthaloyl chloride in this embodiment 2 is the same as that in embodiment 1, except that when there is one row of microchannels, the continuous phase feed module contains two rows of material channels, including one row of feed channels and one row of discharge channels, that is, one inlet and one outlet. At this time, the continuous phase inlet is one feed branch, which is connected to the feed channel. The discharge channel is one discharge branch, which is connected to the discharge channel, and the discharge branch is connected to the material outlet.

[0116] Example 3

[0117] This embodiment provides a continuous production process of isophthaloyl chloride / terephthaloyl chloride, using the continuous production system of embodiment 1, comprising the following steps:

[0118] (1) isophthalic acid / terephthalic acid, thionyl chloride and a catalyst are uniformly mixed in a mixing tank, and the materials in the mixing tank enter a first reactor and undergo a reflux reaction in the first reactor;

[0119] (2) the reaction product of step (1) is introduced into the microreactor through the continuous phase inlet, and a set amount of thionyl chloride is added into the microreactor through the dispersed phase inlet, the added thionyl chloride is dispersed into droplets through the micro-mesh membrane, mixed with the material after the reaction in step (1), and the mixed liquid flows out from the material outlet;

[0120] (3) The product at the material outlet of the microreactor enters the second reactor and undergoes a reflux reaction in the second reactor to obtain a crude product of isophthaloyl chloride or terephthaloyl chloride;

[0121] (4) The crude isophthaloyl chloride / terephthaloyl chloride product enters the atmospheric pressure desolventizing tower and the negative pressure desolventizing tower in turn, and the thionyl chloride in the crude isophthaloyl chloride / terephthaloyl chloride product is separated and flows into the thionyl chloride recovery tank from the top of the tower;

[0122] (5) The materials in the bottom of the negative pressure desolventizing tower are fed into the product distillation tower to obtain qualified isophthaloyl chloride. The purity of the produced isophthaloyl chloride reaches 99.9% and the yield is 99%.

[0123] Among them, the sources of thionyl chloride are new thionyl chloride and recycled thionyl chloride. Recycled thionyl chloride is preferred, and new thionyl chloride is used as a supplement. Figure 1 As shown in, the thionyl chloride in the mixing tank has new thionyl chloride added, and also has the added of recovered thionyl chloride from the thionyl chloride recovery tank booster pump.

[0124] Sulfur oxychloride is added twice, the first time is added to the reactor, and the second time is added to the microreactor. In this embodiment, the ratio of the two additions is 1.

[0125] In step (1), the molar ratio of thionyl chloride to isophthalic acid is 2:1; the amount of catalyst used is 1.5% of the mass of isophthalic acid; and the catalyst is N,N-dimethylformamide (DMF).

[0126] In the first reactor, the reflux reaction conditions are as follows: the reaction pressure is controlled at 20 kPa and the reaction temperature is controlled at 80°C.

[0127] In step (2), in the microreactor, the molar ratio of thionyl chloride to isophthalic acid / terephthalic acid is 2:1.

[0128] In the second reactor, the reflux reaction conditions are as follows: the reaction pressure is controlled at 20 kPa and the reaction temperature is controlled at 80°C.

[0129] In the atmospheric pressure desolventizing tower, the pressure is atmospheric pressure and the tower bottom temperature is 107°C. In the negative pressure desolventizing tower, the vacuum degree is 90 kPa and the tower bottom temperature is 105°C.

[0130] In the distillation tower, the vacuum degree is 99 kPa, the top temperature is 146°C, and the bottom temperature is 160°C.

[0131] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A continuous production system of isophthaloyl chloride / terephthaloyl chloride, characterized in that: The invention comprises a first reactor, a microreactor and a second reactor connected in sequence; the first reactor is connected to one end of the microreactor through a pipeline, and the other end of the microreactor is connected to the second reactor through a pipeline; the microreactor is provided with a dispersed phase feeding module, a microsieve membrane, a microchannel plate, a continuous phase feeding module and a cover plate in sequence from bottom to top; The microchannel plate is composed of a plurality of microchannels arranged in parallel, and is composed of one or more columns; the continuous phase feed module is provided with a continuous phase inlet and a material outlet, respectively, and the dispersed phase feed module is provided with a dispersed phase inlet; The continuous phase feed module contains multiple rows of material channels, including feed channels and discharge channels; one end of the microchannel is connected to the feed channel of the feed module, and the other end is connected to the discharge channel of the feed module, the feed channel of the feed module is connected to the continuous phase inlet, and the discharge channel of the feed module is connected to the material outlet; The continuous phase inlet is divided into a single or multiple feed branches, one feed branch is connected to a row of feed channels, and the number of rows of feed channels is the same as the number of feed branches at the continuous phase inlet; the material outlet is divided into a single or multiple discharge branches, one discharge branch is connected to a row of discharge channels, and the number of rows of discharge channels is the same as the number of discharge branches; When the number of microchannel columns is n, there are (n+1) columns of material channels. At this time: When n is an odd number, the number of feed channel columns = the number of discharge channel columns = ; When n is an even number, the number of feed channel columns = , discharge channel = +1; or discharge channel column = ; Number of feed channel columns = +1; Wherein, n≥1, n is an integer; The continuous phase feed module is provided with a heat exchange module, including a heat exchange pipeline, the heat exchange pipeline is located above the feed channel and the discharge channel; a steam inlet is provided at one end of the heat exchange pipeline, and a steam outlet is provided at the other end; It also includes a thionyl chloride separation device, which includes a normal pressure desolventizing tower and a negative pressure desolventizing tower; the second reaction kettle, the normal pressure desolventizing tower and the negative pressure desolventizing tower are connected in sequence through pipelines; The pipeline coming out from the bottom of the atmospheric pressure desolventizing tower is connected to the atmospheric pressure desolventizing tower pump, and the other end of the atmospheric pressure desolventizing tower pump has two connecting pipelines, one connecting pipeline is connected to the middle of the negative pressure desolventizing tower, and the other connecting pipeline is connected to one end of the reboiler below the atmospheric pressure desolventizing tower, and then the other end of the reboiler below the atmospheric pressure desolventizing tower is connected to the atmospheric pressure desolventizing tower; The pipeline coming out from the bottom of the negative pressure desolventizing tower is connected to the negative pressure desolventizing tower pump, and the other end of the normal pressure desolventizing tower pump has two connecting pipelines, one connecting pipeline is connected to the distillation tower, and the other connecting pipeline is connected to one end of the reboiler below the negative pressure desolventizing tower. The reboiler is divided into two pipelines, one pipeline is connected to the negative pressure desolventizing tower, and the other pipeline is connected to the hot water tank; The top of the atmospheric pressure desolventizing tower is connected to one end of the condenser above the atmospheric pressure desolventizing tower through a pipeline, and the other end of the condenser above the atmospheric pressure desolventizing tower has two connecting pipelines, one connecting pipeline is connected to the thionyl chloride recovery tank, and the other connecting pipeline is connected to the top of the atmospheric pressure desolventizing tower; The top of the negative pressure desolventizing tower is connected to one end of the condenser above the negative pressure desolventizing tower through a pipeline, and the other end of the condenser above the negative pressure desolventizing tower has two connecting pipelines, one connecting pipeline is connected to the top of the negative pressure desolventizing tower, and the other connecting pipeline is connected to the pipeline of the other end of the condenser above the normal pressure desolventizing tower and the thionyl chloride recovery tank, and the separated thionyl chloride in the normal pressure desolventizing tower and the negative pressure desolventizing tower are collected and transported to the thionyl chloride recovery tank; The isophthalic acid / terephthalic acid, thionyl chloride and catalyst are uniformly mixed in a mixing tank, and the materials in the mixing tank enter the first reactor for reaction; the reaction product obtained in the first reactor enters the microreactor as a continuous phase through a continuous phase inlet, and a set amount of thionyl chloride is added to the microreactor through a dispersed phase inlet, the added thionyl chloride is dispersed into tiny droplets through a micro-sieve membrane, enters a microchannel, and reacts with the continuous phase, and the mixed liquid flows out from a material outlet.

2. The continuous production system of isophthaloyl chloride / terephthaloyl chloride according to claim 1, characterized in that: The thickness of the microchannel plate is 1-3 mm; The micro-mesh membrane is a porous membrane with a pore size of 5 micrometers to 1.0 millimeters.

3. The continuous production system of isophthaloyl chloride / terephthaloyl chloride according to claim 1, characterized in that: One end of the feed channel is connected to the continuous phase inlet and the other end is closed, and one end of the discharge channel is connected to the material outlet and the other end is closed; the microchannel plate is fitted with the continuous phase feed module, and the continuous phase material is mixed with the dispersed phase from the feed channel through the microreactor and enters the discharge channel; The feed channel and the discharge channel are slotted in the continuous phase feed module.

4. The continuous production system of isophthaloyl chloride / terephthaloyl chloride according to claim 1, characterized in that: It also includes a mixing tank, which is connected to the first reaction kettle through a pipeline; It also includes a first reactor condenser and a second reactor condenser; the first reactor condenser is connected to the top of the first reactor, and the second reactor condenser is connected to the top of the second reactor; The thionyl chloride recovery tank is connected to the condenser above the normal pressure desolventizing tower through a pipeline, and is also connected to the condenser above the negative pressure desolventizing tower through a pipeline; the thionyl chloride recovery tank is also connected to a mixing tank.

5. The continuous production system of isophthaloyl chloride / terephthaloyl chloride according to claim 1, characterized in that: It also includes an evaporator, a negative pressure desolventizing tower, a distillation tower and an evaporator connected in sequence through pipelines; The distillation tower has a pipeline coming out of the bottom connected to a distillation tower pump, and the other end of the distillation tower pump has two connecting pipelines, one connecting pipeline is connected to the top side of the evaporator, and the other connecting pipeline is connected to one end of the reboiler below the distillation tower, and then the other end of the reboiler below the distillation tower is connected to the distillation tower; The top of the distillation tower is connected to one end of the condenser above the distillation tower through a pipeline, and the other end of the condenser above the distillation tower has two connecting pipelines, one connecting pipeline is connected to the negative pressure desolventizing tower, and the other connecting pipeline is connected to the top of the distillation tower; one side of the cooling medium of the condenser above the distillation tower is also connected to the reboiler below the negative pressure desolventizing tower; The evaporator has one side of the top connected to the pipeline coming out of the distillation tower pump, the bottom of the evaporator is the heavy component discharge port, the other side of the top of the evaporator is connected to one end of the condenser above the light component recovery tank, and the bottom of the light component recovery tank is connected to the distillation tower.

6. A continuous production process of isophthaloyl chloride / terephthaloyl chloride, using the continuous production system of isophthaloyl chloride / terephthaloyl chloride according to any one of claims 1 to 5, characterized in that: The steps include: (1) isophthalic acid / terephthalic acid, thionyl chloride and a catalyst are uniformly mixed in a mixing tank, and the materials in the mixing tank are introduced into a first reaction kettle for reaction; (2) the reaction product of step (1) is introduced into the microreactor as a continuous phase through the continuous phase inlet, and a set amount of thionyl chloride is added into the microreactor through the dispersed phase inlet. The added thionyl chloride is dispersed into tiny droplets through the micro-mesh membrane, enters the microchannel, and reacts with the continuous phase, and the mixed liquid flows out from the material outlet; (3) The product at the outlet of the microreactor enters the second reactor for reaction to obtain crude isophthaloyl chloride / terephthaloyl chloride; (4) The crude isophthaloyl chloride / terephthaloyl chloride product enters a normal pressure desolventizing tower and a negative pressure desolventizing tower in turn, and thionyl chloride in the crude isophthaloyl chloride / terephthaloyl chloride product is separated and flows into a thionyl chloride recovery tank from the top of the tower; (5) The materials in the bottom of the negative pressure desolventizing tower are fed into the product distillation tower to obtain qualified isophthaloyl / terephthaloyl chloride.

7. The continuous production process according to claim 6, characterized in that: In step (1), the molar ratio of thionyl chloride to isophthalic acid is (1-3):1; the amount of catalyst is 1-2% of the mass of isophthalic acid; the catalyst is N,N-dimethylformamide or pyridine; In the first reactor, the reaction conditions are as follows: the reaction pressure is controlled to be 0-25 kPa and the reaction temperature is controlled to be 60-100°C; In step (2), in the microreactor, the molar ratio of thionyl chloride to isophthalic acid / terephthalic acid is (1-3):1; In step (3), in the second reactor, the reaction conditions are as follows: the reaction pressure is controlled to be 0-25 kPa, and the reaction temperature is controlled to be 60-100°C.

8. The continuous production process according to claim 6, characterized in that: In the atmospheric pressure desolventizing tower, the pressure is atmospheric pressure and the temperature of the tower bottom is 100-130°C; In the negative pressure desolventizing tower, the vacuum degree is 80-100 kPa, and the temperature of the tower kettle is 100-130°C; In the distillation tower, the vacuum degree is 95-100 kPa, the tower top temperature is 130-150°C, and the tower bottom temperature is 150-170°C.

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