Method and device for continuously recovering isopropanol in 3-bromo-1-(3-chloropyridine-2-yl)-1H-pyrazole-5-ethyl formate centrifugal mother liquor

Abstract

The invention relates to the technical field of chemical production, and particularly discloses a method and a device for continuously recovering isopropanol in centrifugal mother liquor of ethyl 3-bromo-1-(3-chloropyridine-2-yl)-1H-pyrazole-5-formate. The invention relates to a method for continuously recovering isopropyl alcohol in 3-bromo-1-(3-chloropyridine-2-yl)-1H-pyrazole-5-ethyl formate centrifugal mother liquor, which comprises the following steps: carrying out two times of preheating treatment on the centrifugal mother liquor, forming a concentrated solution of the centrifugal mother liquor and isopropyl alcohol recovery steam under the action of a scraper film evaporator, and condensing and recovering the isopropyl alcohol recovery steam. According to the method for continuously recovering the isopropanol in the 3-bromo-1-(3-chloropyridine-2-yl)-1H-pyrazole-5-ethyl formate centrifugal mother liquor, continuous operation can be achieved, the recovery rate of the isopropanol in the centrifugal mother liquor is larger than or equal to 98%, the purity of the recovered isopropanol is larger than or equal to 99%, and the method has important industrial application value.

Description

Technical Field

[0001] The present application relates to the technical field of chemical production, and more specifically, it relates to a method and device for continuously recovering isopropanol from the centrifugal mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate. Background Art

[0002] Ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate is an important organic compound. As a key intermediate of chlorantraniliprole, it has broad application prospects in the pesticide field. Chlorantraniliprole is a highly efficient, broad-spectrum, and low-toxic o-formamido benzamide insecticide, which is an environmentally friendly green chemical insecticide. Due to its high efficacy against Lepidoptera insects, it has become an important and indispensable pesticide variety in modern agriculture.

[0003] The main synthesis method of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate is as follows: Using (3-chloro-2-pyridinyl)-3-hydroxy-4,5-dihydro-1H-pyrazole-5-carboxylate as the raw material, bromination is carried out with phosphorus oxychloride tribromide to obtain ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate. Then, water is added to quench the unreacted phosphorus oxychloride tribromide. After liquid separation, the organic phase is distilled. After removing the solvent, isopropanol is added for recrystallization, and finally, ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate solid is obtained by centrifugation.

[0004] In the synthesis process of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate, isopropanol, as an important solvent, is widely used in the recrystallization step to improve the purity and yield of the product. However, after the synthesis process is completed, centrifugal mother liquor containing isopropanol and other impurities will be generated. The content of isopropanol in these centrifugal mother liquors is usually relatively high. If it fails to be effectively removed, it will seriously affect the quality and performance of the final product, chlorantraniliprole. Therefore, how to efficiently and environmentally recover isopropanol from the centrifugal mother liquor has become an urgent problem to be solved.

[0005] Traditional isopropanol recovery methods mainly adopt kettle distillation technology and rectifying tower technology. However, for the above-mentioned related technologies, the inventors found that kettle distillation technology has problems such as low production efficiency and complicated operation, which is difficult to meet the needs of modern chemical production efficiency and continuity. In addition, for centrifugal mother liquor containing more impurities and viscosity, problems such as equipment blockage and high energy consumption are also prone to occur in the kettle distillation process, which further limits its application range; although the rectifying tower technology has the advantages of high efficiency and continuity, when processing the centrifugal mother liquor containing a large amount of impurities and viscous materials, its filler is easily blocked, resulting in a decrease in recovery efficiency, an increase in equipment maintenance cost, and a certain limitation in the application of the continuous recovery of isopropanol. Therefore, there is an urgent need for a more efficient, reliable and environmentally friendly isopropanol continuous recovery technology to solve the current production efficiency and equipment blockage problems and create greater value for enterprises. Summary of the invention

[0006] In order to improve the production efficiency of continuous recovery of isopropanol and reduce the adverse effects of equipment blockage on isopropanol recovery, the present application provides a method and apparatus for continuously recovering isopropanol from the centrifugal mother liquor of 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid ethyl ester.

[0007] The present application provides a method for continuously recovering isopropanol from the centrifugal mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate, which adopts the following technical scheme: The invention relates to a device for continuously recovering isopropanol from the centrifugal mother liquor of 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid ethyl ester. The device for continuously recovering isopropanol from the centrifugal mother liquor of 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid ethyl ester comprises a feed kettle (1), a feed pump (2), a preheater (3), a scraper film evaporator (4), a concentrated liquid receiving kettle (5), a feed pump (6), a condenser (7), an isopropanol receiving tank (8) and a vacuum pump (9) which are interconnected. One end of the scraper film evaporator (4) is connected to the concentrated liquid receiving kettle (5), and the other end is connected to the isopropanol receiving tank (8); The specific steps include: S1: The centrifuged mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate is transported to a feed kettle (1) for stirring and first preheating, and then transported to a preheater (3) under the action of a feed pump (2) for second preheating to obtain a pretreated mother liquor; S2: Turn on the vacuum pump (9) to evacuate the pretreated mother liquor, and transport it to the scraped film evaporator (4) at a transport rate of 20-25 g / min for stirring and evaporation to obtain isopropyl alcohol recovery vapor and concentrated liquid; S3: The concentrated liquid is discharged from the bottom of the wiped film evaporator (4) into the concentrated liquid receiving kettle (5), stirred under heating conditions, and then transported to related processes for post-treatment of the concentrated liquid by a feeding pump (6). The isopropanol recovery vapor flows out from the top of the wiped film evaporator (4) and is condensed and recovered into the isopropanol receiving tank (8) through the condenser (7).

[0008] By adopting the above technical solutions, each component is connected in series to achieve mutual communication, realizing the continuous operation of the whole process from the feeding of the centrifugal mother liquor to the separate recovery, avoiding the downtime caused by the intermittent operation of the traditional batch distillation, and significantly improving the production efficiency. The coordinated use of the vacuum pump and the condenser ensures the rapid condensation and recovery of the isopropanol vapor, reduces the residence time of the solvent, and helps to increase the throughput per unit time and the recovery purity of isopropanol.

[0009] By using a wiped film evaporator, a high-speed rotating scraper is used to force the formation of a film, and rapid evaporation is carried out on the heating surface, so that the solvent in the mother liquor evaporates rapidly, forming secondary vapor, which is condensed and discharged for recovery by the upper condenser, and the concentrated liquid is discharged from the bottom, avoiding the coking or solid deposition of the centrifugal mother liquor on the inner wall of the evaporator, and avoiding the blockage problem caused by the adhesion of materials in the traditional rectification column. It is particularly suitable for treating the centrifugal mother liquor containing impurities and high-viscosity ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate. The linkage between the concentrated liquid receiving kettle and the feeding pump ensures the timely discharge of the concentrated liquid, can effectively prevent the blockage of pipelines or equipment caused by the accumulation of residues, reduces energy consumption at the same time, realizes the continuous production of isopropanol recovery, significantly improves the production efficiency, is easy to operate, and has significant industrial application value.

[0010] Optionally, the content of isopropanol in the centrifugal mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate is 60-90%.

[0011] Optionally, in step S1, the first preheating temperature is 40-50 °C, and the second preheating temperature is 50-60 °C.

[0012] By adopting the above technical solutions, the purpose of the first preheating in the process of preheating the centrifugal mother liquor in stages is to reduce the initial viscosity of the centrifugal mother liquor, facilitate pumping, and the purpose of the second further preheating is to further reduce the viscosity, ensuring that the centrifugal mother liquor reaches the best fluidity before entering the wiped film evaporator, improving the evaporation efficiency, balancing the pumping requirements and thermal stability, and avoiding local blockage caused by cooling and solidification in the preheater or the inlet / outlet pipelines.

[0013] In addition, by preheating the centrifuged mother liquor in stages and gradually increasing the temperature, it can effectively prevent the generation of impurities and the degradation of products caused by the decomposition of some thermosensitive substances in the centrifuged mother liquor, which may affect the purity of the subsequent continuous recovery of isopropanol.

[0014] Optionally, the purity of isopropanol recovered and condensed by the condenser into the isopropanol receiving tank is ≥99%, and the recovery rate of isopropanol is ≥98%.

[0015] Optionally, the conditions for evaporation in the wiped film evaporator in step S2 are: temperature 80 - 120°C, pressure 5 - 10 kPa, and rotation speed 200 - 300 rpm.

[0016] By adopting the above technical solution, isopropanol can be rapidly evaporated under the most suitable conditions, avoiding carbonization and coking of the centrifuged mother liquor caused by high temperature and the formation of precipitates due to too long residence time on the inner wall of the evaporator, effectively preventing the problem of evaporator blockage, and effectively improving the production efficiency and recovery stability of continuous isopropanol recovery.

[0017] Optionally, the heating temperature of the concentrated liquid receiving kettle in step S3 is 70 - 80°C.

[0018] By adopting the above technical solution, 70 - 80°C can effectively maintain the fluidity of the concentrated liquid, prevent a significant increase in viscosity or solidification after cooling, ensure that the feeding pump can smoothly transport it to other relevant processes for post-treatment, and prevent the accumulation and blockage of the concentrated liquid in the receiving kettle or pipeline.

[0019] Optionally, the wiped film evaporator adopts a thin film evaporator with model DEA - BM - 5, the evaporation area is 0.058 m2, and the material processing capacity is 0.5 - 1.5 kg / h.

[0020] By adopting the above technical solution, selecting a thin film evaporator with model DEA - BM - 5 to match other components ensures precise control of the treatment volume of the centrifuged mother liquor in continuous production, which can not only meet industrial requirements but also avoid efficiency decline caused by overloading. Its scraper rotation speed and film thickness parameters can effectively prevent blockage caused by organic matter residues or crystal precipitation in the centrifuged mother liquor.

[0021] Optionally, the feeding kettle and the concentrated liquid receiving kettle adopt a double-layer explosion-proof glass reaction kettle with model SF - 2L.

[0022] By adopting the above technical solution, the double-layer explosion-proof glass reaction kettle of SF - 2L has good temperature control performance through jacket heating, ensuring the fluidity of the centrifuged mother liquor during the feeding and concentrated liquid receiving processes, and avoiding the blockage of pipelines caused by material solidification due to temperature fluctuations.

[0023] To sum up, the present application has the following beneficial effects: 1. Through the series connection between the feed kettle, feed pump, preheater, scraping film evaporator, concentrated liquid receiving kettle, pumping pump, condenser, isopropanol receiving tank and vacuum pump, seamless connection of the whole process of centrifugal mother liquor treatment is realized, effectively reducing the time-consuming problem of frequent shutdown for feeding and slag discharging in the traditional distillation recovery method, realizing efficient continuous treatment of isopropanol recovery, and significantly improving the production efficiency of isopropanol.

[0024] 2. In this application, forced film formation is carried out by the scraping film evaporator, effectively reducing the equipment blockage problem caused by material adhesion, coking or solidification in the traditional recovery process, reducing energy consumption, being easy to operate, suitable for industrial production, and realizing that the purity of recovered isopropanol ≥ 99% and the recovery rate of isopropanol ≥ 98%.

[0025] 3. The method of this application preheats in stages, gradually raises the temperature, and gradually reduces the viscosity of the centrifugal mother liquor, making it more convenient for pumping, ensuring the best fluidity of the centrifugal mother liquor before entering the scraping film evaporator, helping to improve the evaporation efficiency, balancing the pumping demand and thermal stability, avoiding local blockage caused by cooling and solidification in the preheater or the inlet / outlet pipeline, and further ensuring the high recovery rate and high recovery purity of isopropanol. Description of the Drawings

[0026] Figure 1 It is a device diagram for continuously recovering isopropanol from the centrifugal mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate in this application.

[0027] Description of the reference numerals: 1. Feed kettle; 2. Feed pump; 3. Preheater; 4. Scraping film evaporator; 5. Concentrated liquid receiving kettle; 6. Pumping pump; 7. Condenser; 8. Isopropanol receiving tank; 9. Vacuum pump. Detailed Description of the Embodiment

[0028] The following embodiments further illustrate this application in detail. Embodiment Embodiment 1

[0029] A device for continuously recovering isopropanol from the centrifugal mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate, as Figure 1 shown, includes a feed kettle 1, a feed pump 2, a preheater 3, a scraping film evaporator 4, a concentrated liquid receiving kettle 5, a pumping pump 6, a condenser 7, an isopropanol receiving tank 8 and a vacuum pump 9 that are interconnected. The above-mentioned various device components are interconnected through the feed pipelines or discharge pipelines of each device component.

[0030] Among them, the feeding kettle 1 adopts a double-layer explosion-proof glass reactor with the model of SF-2L. The kettle body of the feeding kettle 1 is provided with a jacket, which is used to preheat the centrifugal mother liquor in the kettle when hot water is introduced. A stirring device is arranged in the kettle to stir the centrifugal mother liquor. The feeding pipeline of the kettle body is arranged at the top of the kettle body, and the discharging pipeline is arranged at the bottom of the kettle body. The discharging pipeline of the feeding kettle 1 is communicated with the feeding pipeline of the feeding pump 2.

[0031] The discharging pipeline of the feeding pump 2 is communicated with the feeding pipeline of the preheater 3. The outer layer of the preheater 3 is provided with a jacket, and hot water is introduced into the jacket to adjust and maintain the temperature of the centrifugal mother liquor. The centrifugal mother liquor heated and stirred by the feeding kettle 1 is pumped by the feeding pump 2 to the preheater 3 for preheating, and then is transported to the scraping thin-film evaporator 4 through the discharging pipeline of the preheater 3.

[0032] The scraping thin-film evaporator 4 adopts a thin-film evaporator with the model of DEA-BM-5, which has an evaporation area of 0.058 m 2 and a processing capacity of 0.5 - 1.5 kg / h. The outer layer of the scraping thin-film evaporator 4 is provided with a jacket, and heat-conducting oil is introduced as a heating source to evaporate the internal centrifugal mother liquor. A rotating shaft is arranged inside the scraping thin-film evaporator 4, and a sliding scraper is installed on the rotating shaft. Through the rotation of the rotating shaft, the scraper forms a uniform thin film on the heating surface of the inner wall of the scraping thin-film evaporator 4 to ensure an efficient evaporation process. A regulating valve is installed on the feeding pipeline on the side where the scraping thin-film evaporator 4 is communicated with the preheater 3 to control the speed of the centrifugal mother liquor entering the scraping thin-film evaporator 4. There are two discharging pipelines on the other side of the scraping thin-film evaporator 4. One discharging pipeline is arranged near the top outside the scraping thin-film evaporator 4 and is communicated with the condenser 7 to realize the condensation and recovery of the solvent isopropanol in the centrifugal mother liquor. One discharging pipeline is arranged at the bottom of the scraping thin-film evaporator 4 and is communicated with the concentrated liquid receiving kettle 5 to transport the concentrated liquid of the centrifugal mother liquor into the concentrated liquid receiving kettle 5.

[0033] A vacuum pump 9 is arranged on one side of the condenser 7. The vacuum pump 9 is a two-stage rotary vane vacuum pump 9, which is used to evacuate the inside of the condenser 7. The outer layer of the condenser 7 is provided with a jacket, and cold water is introduced to condense the solvent isopropanol inside the condenser 7. The discharging pipeline of the condenser 7 is communicated with the isopropanol receiving tank 8. The discharging pipeline of the scraping thin-film evaporator 4 transports the solvent isopropanol in the centrifugal mother liquor to the condenser 7, and the condensation recovery of isopropanol is realized under the condensation effect.

[0034] The concentrated liquid receiving kettle 5 and the feeding kettle 1 adopt double-layer explosion-proof glass reaction kettles of the same model SF-2L. A stirring device is arranged inside the kettle body to ensure the uniform mixing of the concentrated liquid in the kettle body. A jacket is arranged outside the kettle body to prevent the centrifugal mother liquor concentrated liquid from caking at low temperatures and ensure the fluidity and stability of the centrifugal mother liquor concentrated liquid. The discharge pipeline of the concentrated liquid receiving kettle 5 is communicated with the feeding pump 6, and the discharge pipeline of the feeding pump 6 transports the concentrated liquid of the centrifugal mother liquor to the next process for relevant process treatment of the concentrated liquid. Application example

[0035] A method for continuously recovering isopropanol from the centrifugal mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate is carried out by using the device for continuously recovering isopropanol from the centrifugal mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate in Application Example 1.

[0036] Application Example 1 A method for continuously recovering isopropanol from the centrifugal mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate comprises the following steps: S1: Open the valve of the feeding pipeline of the feeding valve, and transport 1800 g of the centrifugal mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate to the feeding kettle 1. The content of isopropanol in the centrifugal mother liquor is 70%. Pass hot water into the jacket of the feeding kettle 1 for circulation to make the temperature in the kettle 45 °C for the first preheating. Start stirring, and then under the action of the feeding pump 2, transport the centrifugal mother liquor to the preheater 3 for the second preheating at 55 °C to obtain the pretreated mother liquor. S2: Start the vacuum pump 9 to pump vacuum, and start the circulating water in the jacket of the condenser 7 and the heat-conducting oil in the jacket of the wiped film evaporator 4 to make the temperature in the wiped film evaporator 4 reach 100 °C. After the vacuum degree is stable, adjust the regulating valve on the feeding pipeline of the wiped film evaporator 4, and transport the pretreated mother liquor to the wiped film evaporator 4 at a transport flow rate of 22 g / min. Carry out stirring evaporation under the conditions of a pressure of 6 kPa and a rotation speed of 200 rpm. The centrifugal mother liquor enters the wiped film evaporator 4 along the tangential direction of the feeding pipeline. Under the action of gravity and the scraper, a uniform liquid film is formed, and then isopropanol recovery vapor and concentrated liquid are obtained. S3: The concentrated liquid is discharged from the bottom of the wiped film evaporator 4 to the concentrated liquid receiving kettle 5, and stirring is carried out under the condition of heating at 75 °C. After a certain amount of concentrated liquid is reached in the kettle, it is transported to the relevant process for post-treatment of the concentrated liquid through the feeding pump 6. The isopropanol recovery vapor flows out from the top of the wiped film evaporator 4 and is condensed and recovered into the isopropanol receiving tank 8 through the condenser 7.

[0037] Application Example 2 A method for continuously recovering isopropanol from the centrifugal mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate, comprising the following steps: S1: Open the feed pipeline valve of the feed valve, and transfer 1800 g of the centrifugal mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate to the feed kettle 1. The content of isopropanol in the centrifugal mother liquor is 90%. Pass hot water through the jacket of the feed kettle 1 for circulation to make the temperature in the kettle 40 °C for the first preheating. Start stirring, and then transfer the centrifugal mother liquor to the preheater 3 under the action of the feed pump 2 for the second preheating at 50 °C to obtain the pretreated mother liquor; S2: Turn on the vacuum pump 9 to pump vacuum, turn on the jacket circulating water of the condenser 7 and the jacket heat-conducting oil of the wiped film evaporator 4 to make the temperature in the wiped film evaporator 4 reach 80 °C. After the vacuum degree is stable, adjust the regulating valve on the feed pipeline of the wiped film evaporator 4, and transfer the pretreated mother liquor to the wiped film evaporator 4 at a conveying flow rate of 20 g / min. Carry out stirring evaporation under the conditions of a pressure of 10 kPa and a rotation speed of 300 rpm. The centrifugal mother liquor enters the wiped film evaporator 4 along the tangential direction of the feed pipeline, and under the action of gravity and the scraper, a uniform liquid film is formed, and then isopropanol recovery vapor and concentrated liquid are obtained; S3: The concentrated liquid is discharged from the bottom of the wiped film evaporator 4 to the concentrated liquid receiving kettle 5, and stirring is carried out under the condition of heating at 80 °C. After a certain amount of concentrated liquid is reached in the kettle, it is transported to the relevant process for post-treatment of the concentrated liquid through the feeding pump 6. The isopropanol recovery vapor flows out from the top of the wiped film evaporator 4 and is condensed and recovered into the isopropanol receiving tank 8 through the condenser 7.

[0038] Application Example 3 A method for continuously recovering isopropanol from the centrifugal mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate, comprising the following steps: S1: Open the feed pipeline valve of the feed valve, and transfer 1800 g of the centrifugal mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate to the feed kettle 1. The content of isopropanol in the centrifugal mother liquor is 85%. Pass hot water through the jacket of the feed kettle 1 for circulation to make the temperature in the kettle 50 °C for the first preheating. Start stirring, and then transfer the centrifugal mother liquor to the preheater 3 under the action of the feed pump 2 for the second preheating at 60 °C to obtain the pretreated mother liquor; S2: Turn on the vacuum pump 9 to evacuate the air, turn on the jacket circulating water of the condenser 7 and the jacket heat-conducting oil of the scraping thin-film evaporator 4, so that the temperature inside the scraping thin-film evaporator 4 reaches 108 °C. After the vacuum degree is stable, adjust the regulating valve on the feed pipeline of the scraping thin-film evaporator 4, and convey the pretreated mother liquor to the scraping thin-film evaporator 4 at a conveying flow rate of 23.5 g / min. Carry out stirring evaporation under the conditions of a pressure of 8 kPa and a rotation speed of 300 rpm. The centrifuged mother liquor enters along the tangent direction of the feed pipeline of the scraping thin-film evaporator 4, and under the action of gravity and the scraper, a uniform liquid film is formed, and then isopropyl alcohol recovery vapor and concentrated liquid are obtained; S3: The concentrated liquid is discharged from the bottom of the scraping thin-film evaporator 4 into the concentrated liquid receiving kettle 5, and stirring is carried out under the condition of heating at 75 °C. After a certain amount of concentrated liquid is in the kettle, it is conveyed to the relevant process for post-treatment of the concentrated liquid through the feeding pump 6. The isopropyl alcohol recovery vapor flows out from the top of the scraping thin-film evaporator 4 and is condensed and recovered into the isopropyl alcohol receiving tank 8 through the condenser 7.

[0039] Application Example 4 A method for continuously recovering isopropyl alcohol from the centrifuged mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate, comprising the following steps: S1: Open the valve of the feed pipeline of the feed valve, and convey 1800 g of the centrifuged mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate to the feed kettle 1. The content of isopropyl alcohol in the centrifuged mother liquor is 60%. Pass hot water into the jacket of the feed kettle 1 for circulation to make the temperature in the kettle 45 °C for the first preheating. Turn on the stirring, and then convey the centrifuged mother liquor to the preheater 3 under the action of the feed pump 2 for the second preheating at 50 °C to obtain the pretreated mother liquor; S2: Turn on the vacuum pump 9 to evacuate the air, turn on the jacket circulating water of the condenser 7 and the jacket heat-conducting oil of the scraping thin-film evaporator 4, so that the temperature inside the scraping thin-film evaporator 4 reaches 120 °C. After the vacuum degree is stable, adjust the regulating valve on the feed pipeline of the scraping thin-film evaporator 4, and convey the pretreated mother liquor to the scraping thin-film evaporator 4 at a conveying flow rate of 25 g / min. Carry out stirring evaporation under the conditions of a pressure of 5 kPa and a rotation speed of 300 rpm. The centrifuged mother liquor enters along the tangent direction of the feed pipeline of the scraping thin-film evaporator 4, and under the action of gravity and the scraper, a uniform liquid film is formed, and then isopropyl alcohol recovery vapor and concentrated liquid are obtained; S3: The concentrated liquid is discharged from the bottom of the scraping thin-film evaporator 4 into the concentrated liquid receiving kettle 5, and stirring is carried out under the condition of heating at 70 °C. After a certain amount of concentrated liquid is in the kettle, it is conveyed to the relevant process for post-treatment of the concentrated liquid through the feeding pump 6. The isopropyl alcohol recovery vapor flows out from the top of the scraping thin-film evaporator 4 and is condensed and recovered into the isopropyl alcohol receiving tank 8 through the condenser 7.

[0040] Application Example 5 A method for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate, which is different from Application Example 1 in that the specific method of step S1 is as follows: Open the feed pipeline valve of the feed valve, and transfer 1800 g of the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate to the feed kettle 1. The content of isopropanol in the centrifugation mother liquor is 70%. Pass hot water into the jacket of the feed kettle 1 for circulation to make the temperature in the kettle preheat at 45°C. Start stirring, and then transfer the centrifugation mother liquor to the preheater 3 under the action of the feed pump 2, and continue to preheat at 45°C to obtain the pretreated mother liquor. Other steps are the same as those in Application Example 1.

[0041] Application Example 6 A method for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate, which is different from Application Example 1 in that the specific method of step S1 is as follows: Open the feed pipeline valve of the feed valve, and transfer 1800 g of the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate to the feed kettle 1. The content of isopropanol in the centrifugation mother liquor is 70%. Pass hot water into the jacket of the feed kettle 1 for circulation to make the temperature in the kettle preheat at 55°C. Start stirring, and then transfer the centrifugation mother liquor to the preheater 3 under the action of the feed pump 2, and continue to preheat at 55°C to obtain the pretreated mother liquor. Other steps are the same as those in Application Example 1.

[0042] Application Example 7 A method for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate, which is different from Application Example 1 in that the specific method of step S2 is as follows: Turn on the vacuum pump 9 to evacuate, turn on the jacket circulating water of the condenser 7 and the jacket heat-conducting oil of the wiped film evaporator 4, so that the temperature in the wiped film evaporator 4 reaches 108°C. After the vacuum degree is stable, adjust the regulating valve on the feed pipeline of the wiped film evaporator 4, and transfer the pretreated mother liquor to the wiped film evaporator 4 at a conveying flow rate of 22 g / min, and carry out stirring evaporation under the conditions of a pressure of 6 kPa and a rotation speed of 200 rpm. The centrifugation mother liquor enters the wiped film evaporator 4 along the tangential direction of the feed pipeline, and under the action of gravity and the scraper, a uniform liquid film is formed, and then isopropanol recovery vapor and concentrated liquid are obtained. Other steps are the same as those in Application Example 1. Comparative Example

[0043] Comparative Example 1 A method for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate, which is different from Application Example 1 in that the feeding flow rate of the pretreated mother liquor to the wiped film evaporator 4 in step S2 is 17 g / min, and other steps are the same as those in Application Example 1.

[0044] Comparative Example 2 A method for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate, which is different from Application Example 1 in that the feeding flow rate of the pretreated mother liquor to the wiped film evaporator 4 in step S2 is 27 g / min, and other steps are the same as those in Application Example 1. Performance detection test

[0045] The isopropanol recovered by the method for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate in Application Examples 1-7 and Comparative Examples 1-2 was subjected to the following relevant performance detections by gas chromatography (GC).

[0046] Experimental conditions: DB-WAX chromatographic column (30 m×0.25 mm×0.25 μm), carrier gas is high-purity nitrogen, and the flow rate is 1.0 mL / min; Test conditions: The inlet temperature is 210 °C, the initial column temperature is 60 °C, held for 1 min, then increased to 70 °C at 2 °C / min, and then increased to 150 °C at 20 °C / min; the detector temperature is 250 °C, the air flow rate is 400 mL / min, the hydrogen flow rate is 40 mL / min, the tail gas purge flow rate is 30 mL / min, split injection, split ratio is 10:1, and the injection volume is 1 μL; A series of standard solutions of pure isopropanol were prepared. After the conditions of the gas chromatograph were stable, GC separation and detection were carried out. According to the peak area of isopropanol measured by the gas chromatograph, a standard curve was drawn. The centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate, the isopropanol recovered in the isopropanol receiving tank, and the concentrated solution were injected respectively. According to the standard curve equation, the purity of isopropanol in the centrifugation mother liquor, the isopropanol recovered in the isopropanol receiving tank, and the concentrated solution was calculated, and the recovery rate and total loss amount of isopropanol were calculated. Recovery rate (%) = mass of recovered isopropanol / total mass of isopropanol in the centrifugation mother liquor × 100%, total loss rate = (total weight of centrifugation mother liquor - mass of recovered isopropanol - mass of concentrated solution) / total mass of centrifugation mother liquor × 100%. Each group of tests was carried out with 3 repeated tests, and the average value of the 3 test results was taken as the final result and the final result was recorded in Table 1.

[0047] Table 1

[0048] According to the performance test results of Application Examples 1-4 and Application Example 7 in Table 1, it can be seen that the device for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate of the present application can realize the continuous recovery of isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate. The purity of the isopropanol recovered and condensed by the condenser into the isopropanol receiving tank is ≥99.3%, the recovery rate of isopropanol is ≥98.2%, the content of isopropanol in the concentrated solution is ≤1.69%, and the total loss rate is ≤1.46%. This shows that the method for recovering isopropanol by using the device for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate of the present application can efficiently separate and recover isopropanol, obtain high-purity isopropanol, and at the same time obtain a high-purity concentrated solution of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate, and can be widely applied in industry.

[0049] According to the performance test results of Application Examples 1, 3 and Application Example 7, it can be further seen that when the temperature in the wiped film evaporator reaches 108 °C and the pretreated mother liquor is fed into the wiped film evaporator at a feeding flow rate of 23.5 g / min, the separation of isopropanol and ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate can be maximized, higher-purity separation products can be obtained, and the loss rate of the recovery method is also relatively low.

[0050] According to the performance test results of Application Examples 1-4 and Application Examples 5-6, it can be seen that the separation products obtained by preheating the centrifugation mother liquor by means of staged preheating and gradually increasing the temperature have higher purity and lower loss rate. This is because staged preheating can gradually reduce the viscosity of the centrifugation mother liquor, making it more convenient for pumping, ensuring that the centrifugation mother liquor reaches the best fluidity before entering the wiped film evaporator, improving the evaporation efficiency, balancing the pumping requirements and thermal stability, avoiding local blockage caused by cooling and solidification in the preheater or the inlet / outlet pipeline, effectively preventing the generation of impurities and the degradation of products due to the decomposition of some thermosensitive substances in the centrifugation mother liquor, and further ensuring the high recovery rate and high recovery purity of isopropanol.

[0051] According to the performance test results of Application Examples 1-4 and Comparative Examples 1-2, it can be seen that when the pre-treated mother liquor is fed into the wiped film evaporator at a conveying flow rate of 20-25 g / min for stirring evaporation, the feed rate is appropriate, which is more adaptable to the processing capacity of the wiped film evaporator and other components of the device, and can achieve the best working effect of the device, maximizing the evaporation efficiency, thereby ensuring high recovery rate and high recovery purity of isopropanol.

[0052] This specific embodiment is only an interpretation of the present application and does not limit the present application. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate, characterized in that, The invention relates to a device for continuously recovering isopropanol from the centrifugal mother liquor of 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid ethyl ester. The device for continuously recovering isopropanol from the centrifugal mother liquor of 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid ethyl ester comprises a feed kettle (1), a feed pump (2), a preheater (3), a scraper film evaporator (4), a concentrated liquid receiving kettle (5), a feed pump (6), a condenser (7), an isopropanol receiving tank (8) and a vacuum pump (9) which are interconnected. One end of the scraper film evaporator (4) is connected to the concentrated liquid receiving kettle (5), and the other end is connected to the isopropanol receiving tank (8); The specific steps include: S1: The centrifuged mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate is transported to a feed kettle (1) for stirring and first preheating, and then transported to a preheater (3) under the action of a feed pump (2) for second preheating to obtain a pretreated mother liquor; S2: Turn on the vacuum pump (9) to evacuate the pretreated mother liquor, and transport it to the scraped film evaporator (4) at a transport rate of 20-25 g / min for stirring and evaporation to obtain isopropyl alcohol recovery vapor and concentrated liquid; S3: The concentrated liquid is discharged from the bottom of the scraped film evaporator (4) into the concentrated liquid receiving kettle (5), stirred under heating conditions, and then transported to the relevant process for post-treatment of the concentrated liquid through a feed pump (6). The isopropyl alcohol recovery vapor flows out from the top of the scraped film evaporator (4), is condensed in a condenser (7), and is recovered into an isopropyl alcohol receiving tank (8).

2. The method for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate according to claim 1, characterized in that The content of isopropanol in the centrifugal mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate is 60-90%.

3. The method for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate according to claim 2, characterized in that ,In step S1, the first preheating temperature is 40-50℃, and the second preheating temperature is 50-60℃.

4. The method for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate according to claim 3, characterized in that The purity of the isopropanol recovered in the isopropanol receiving tank (8) after condensation in the condenser (7) is ≥99%, and the recovery rate of the isopropanol is ≥98%.

5. The method for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate according to claim 1, characterized in that In step S2, the conditions for evaporation in the scraped film evaporator (4) are: temperature 80-120°C, pressure 5-10 kPa, and rotation speed 200-300 rpm.

6. The method for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate according to claim 1, characterized in that In step S3, the heating temperature of the concentrated liquid receiving kettle (5) is 70-80°C.

7. The method for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate according to claim 1, characterized in that , the scraper thin-film evaporator (4) uses a thin-film evaporator with the model number DEA-BM-5, and the evaporation area is 0.058 m 2 , and the material processing capacity is 0.5 - 1.5 kg / h.

8. The method for continuously recovering isopropanol from the centrifugation mother liquor of ethyl 3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylate according to claim 1, characterized in that The feed kettle (1) and the concentrated liquid receiving kettle (5) are double-layer explosion-proof glass reactors of model SF-2L.

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