Device for synthesizing aspirin by using microchannel continuous flow technology

Abstract

The utility model relates to the technical field of devices for synthesizing aspirin, in particular to a device for synthesizing aspirin by a micro-channel continuous flow technology. According to the technical scheme, the device comprises a premixing system for mixing raw materials, a reaction system for providing reaction conditions for the materials and a continuous post-treatment system for separating and purifying the reacted materials, the premixing system and the reaction system are connected through a polytetrafluoroethylene pipeline, and the reaction system and the continuous post-treatment system are connected through a polytetrafluoroethylene pipeline. A valve is arranged at the joint to control feeding and discharging of materials. According to the utility model, the micro-channel continuous flow technology is applied to the synthesis of aspirin, and the existing equipment in a laboratory is adopted for feeding and heating, so that the continuous reaction is easy to build, the cost is low, the reaction temperature is lower, safety and high efficiency are realized, and the application range is student experiment, practical training and pilot scale production.

Description

TECHNICAL FIELD

[0001] The utility model relates to the device technical field of synthetic aspirin, especially to a device of microchannel continuous flow technology synthetic aspirin. BACKGROUND

[0002] Aspirin, also known as acetylsalicylic acid, is an organic compound, which has been used in clinical application for nearly a hundred years, and is mainly used for antipyretic analgesia. It is better for relieving mild or moderate pain, such as toothache, headache, neuralgia, muscle soreness and dysmenorrhea. It is also used for antipyretic of fever diseases such as cold and influenza, and treatment of rheumatic pain. It can prevent thrombosis.

[0003] The synthesis of aspirin is one of the classic organic basic experiments. The reaction raw material structure is special, and the product composition is relatively complex, which is a good teaching experiment. Microchannel continuous flow synthesis experiment has produced obvious influence in academic and industrial circles in recent years and is more and more popular. Among them, the application publication number CN 109559589 A discloses a modular teaching practice device of aspirin production line, which comprises a reaction kettle. However, the reaction kettle has certain limitations in terms of temperature and pressure, and cannot safely and effectively strengthen the reaction process. UTILITY MODEL CONTENT

[0004] The utility model aims at the problems in the background art, and provides a device of microchannel continuous flow technology synthetic aspirin.

[0005] The technical scheme of the utility model is: a device of microchannel continuous flow technology synthetic aspirin, comprising a premixing system for mixing raw materials, a reaction system for providing reaction conditions for materials, and a continuous post-treatment system for separating and purifying materials after reaction. The premixing system, the reaction system and the continuous post-treatment system are connected through polytetrafluoroethylene pipelines, and valves are arranged at the connection positions to control the inflow and outflow of materials. At the same time, the device can be externally connected with a nitrogen circulation device to discharge the air and moisture in the system, so that the reaction can be carried out under the condition of no water and no oxygen, the reaction rate is improved, and the energy consumption and organic solvent consumption are reduced.

[0006] Optionally, the premixing system comprises an acetic anhydride raw material tank, a salicylic acid raw material tank, a first pump body and a second pump body. The input end of the first pump body is communicated with the acetic anhydride raw material tank, and the input end of the second pump body is communicated with the salicylic acid raw material tank.

[0007] Optionally, the reaction system comprises a micro-channel reactor, a cold-hot well and a heat exchanger, the cold-hot well is set to a temperature of 70-80℃, the output ends of the first pump body and the second pump body are both in communication with the micro-channel reactor, the micro-channel reactor and the heat exchanger are in communication through a first crude product discharge port, the heat exchanger is provided with a water inlet, the heat exchanger and the cold-hot well are in communication through a hot oil liquid inlet, and the micro-channel reactor and the cold-hot well are in communication through a hot oil liquid outlet.

[0008] Optionally, the continuous post-treatment system comprises a wiped film evaporator, a tubular reactor and a horizontal scraper centrifuge, the wiped film evaporator is in communication with the heat exchanger through a second crude product discharge port, the wiped film evaporator is provided with a steam inlet, a condensed water outlet and an organic solvent outlet, the organic solvent outlet is connected with a third pump body, the organic solvent outlet and the input end of the third pump body are in communication, and the output end of the third pump body is connected with an oxygen hexacyclic ring receiving tank.

[0009] Optionally, the wiped film evaporator is provided with a concentrated liquid liquid outlet, the other end of the concentrated liquid liquid outlet is connected with a solid-liquid mixture receiving tank, the solid-liquid mixture receiving tank is connected with a fourth pump body, the solid-liquid mixture receiving tank and the input end of the fourth pump body are connected, the output end of the fourth pump body is in communication with the tubular reactor, the tubular reactor is connected with a hot water inlet, the hot water inlet is connected with a fifth pump body, the hot water inlet and the input end of the fifth pump body are in communication, and the output end of the fifth pump body is connected with a hot water supplier.

[0010] Optionally, the tubular reactor and the horizontal scraper centrifuge are in communication through a solid-liquid mixture inlet, the horizontal scraper centrifuge is provided with a product aspirin discharge port and a liquid outlet, the product aspirin discharge port is connected with a product aspirin receiving tank, and the liquid outlet is connected with a post-treatment liquid receiving tank.

[0011] Optionally, the length of the pipeline in the heat exchanger is 30-50m.

[0012] Optionally, the first pump body and the second pump body are set to have consistent flow rates of 2mL / min-20mL / min and pressures of 0-1bar.

[0013] In summary, the present application has the following at least beneficial technical effects:

[0014] The utility model discloses introduce the microchannel continuous flow technology to the industrial production of aspirin, replace the solvent with the acetic anhydride of irritant for the more gentle organic solvent, and is equipped with solvent recovery device, and it is more favorable to the popularization of teaching experiment. Adopt the corresponding more gentle organic solvent to dissolve material fully, reduced the irritability of material, prevented the pipeline blockage of microchannel continuous flow reactor simultaneously, utilize vacuum pump air pumping, and the feeding device feeds, create the anhydrous oxygen-free reaction environment, make the product yield higher, avoid the product oxidation.

[0015] The utility model discloses use microchannel continuous flow technology in the synthesis of aspirin, adopt laboratory existing equipment to feed and heat, easy to build the continuous reaction, low in cost, the reaction temperature is lower, safe and efficient, can be used in large-scale industrial production of medium and large scale. The utility model discloses can be used in industrial production after equipment replacement, and the production part is connected with continuous automatic post-treatment equipment, organic solution recovery equipment, automatic remote control equipment, can reduce the enterprise production and manpower cost greatly, and compared with the reaction kettle, it is more safe and controllable. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is the structural schematic diagram of the utility model embodiment.

[0017] Sign significance: V1, acetic anhydride raw material tank, V2, salicylic acid raw material tank, V3, oxygen hexacyclic receiving tank, V4, post-processing liquid receiving tank, V5, product aspirin receiving tank, V6, solid-liquid mixture receiving tank, P1, first pump body, P2, second pump body, P3, third pump body, P4, fourth pump body, P5, fifth pump body, R1, microchannel reactor, R2, tubular reactor, E1, cold and hot well, E2, heat exchanger, X1, horizontal scraper centrifuge, T1, scraper type thin film evaporator, B1, hot water supplier, H1, first crude product discharge port, H2, water inlet, H3, hot oil liquid inlet, H4, hot oil liquid outlet, H5, second crude product discharge port, H6, steam inlet, H7, condensed water outlet, H8, organic solvent outlet, H9, concentrated liquid liquid outlet, H10, hot water inlet, H11, solid-liquid mixture inlet, H12, product aspirin discharge port, H13, liquid outlet, Z1, back pressure valve. DETAILED DESCRIPTION

[0018] The technical scheme of the utility model will be further explained in the following in connection with the drawings and specific embodiments.

[0019] Embodiment, such as Figure 1As shown, the utility model provides a device of synthesizing aspirin by microchannel continuous flow technology, including premixing system of mixing raw materials, reaction system of providing reaction condition for material, continuous post processing system of separating and purifying material after reaction, premixing system and reaction system and reaction system and continuous post processing system are all connected through polytetrafluoroethylene pipeline or stainless steel pipeline, the polytetrafluoroethylene pipeline or stainless steel pipeline is equipped with insulating layer, and the connecting place is equipped with valve control material in and out.

[0020] Further, the premixing system includes acetic anhydride raw material tank V1, salicylic acid raw material tank V2, first pump body P1 and second pump body P2, the input end of the first pump body P1 is communicated with the acetic anhydride raw material tank V1, and the input end of the second pump body P2 is communicated with the salicylic acid raw material tank V2. After acetic anhydride and salicylic acid in the acetic anhydride raw material tank V1 and the salicylic acid raw material tank V2 are fully dissolved with sufficient dioxane, they are pumped into the reaction system by the first pump body P1 and the second pump body P2 respectively, the volume of the acetic anhydride raw material tank V1 and the salicylic acid raw material tank V2 is consistent, the flow rate of the first pump body P1 and the second pump body P2 is consistent, and is 2mL / min-20mL / min, and the pressure is 0-1bar.

[0021] The reaction system includes a microchannel reactor R1, a cold-hot well E1 and a heat exchanger E2, the cold-hot well E1 is set to a temperature of 70-80 DEG C, the output ends of the first pump body P1 and the second pump body P2 are communicated with the microchannel reactor R1, the microchannel reactor R1 and the heat exchanger E2 are communicated through a first crude product discharge port H1, a water inlet H2 is arranged on the heat exchanger E2, the heat exchanger E2 and the cold-hot well E1 are communicated through a hot oil liquid inlet H3, the microchannel reactor R1 and the cold-hot well E1 are communicated through a hot oil liquid outlet H4, and the pipeline length in the heat exchanger E2 is 30-50m.

[0022] The pipeline length in the heat exchanger E2 is 30-50m. The first pump body P1 and the second pump body P2 are set to consistent flow rates, and the flow rate is 2mL / min-20mL / min, and the pressure is 0-1bar.

[0023] The material enters the microchannel reactor R1 under the action of the first pump body P1 and the second pump body P2, after the material passes through the microchannel reactor R1, flows into the polytetrafluoroethylene pipeline in the heat exchanger E2 to carry out delay reaction, the micro-reaction part provides the required temperature by the cold-hot well E1, the heated hot oil flows out from the hot oil liquid outlet H4, enters the microchannel reactor R1, then flows into the heat exchanger E2 through the pipeline, and finally flows back to the cold-hot well E1 through the hot oil liquid inlet H3.

[0024] In this embodiment, the continuous post-treatment system comprises a scraped film evaporator T1, a tubular reactor R2, a horizontal scraped blade centrifuge X1, and the tubular reactor R2 can also be a crystallization reactor. The scraped film evaporator T1 is connected to the heat exchanger E2 through a second crude product discharge port H5. The scraped film evaporator T1 is provided with a steam inlet H6, a condensed water outlet H7, and an organic solvent outlet H8. The organic solvent used is dioxane. The organic solvent outlet H8 is connected to a third pump body P3. The output end of the third pump body P3 is connected to a dioxane receiving tank V3.

[0025] Further, the scraped film evaporator T1 is provided with a concentrated liquid liquid outlet H9. The other end of the concentrated liquid liquid outlet H9 is connected to a solid-liquid mixture receiving tank V6. The solid-liquid mixture receiving tank V6 is connected to a fourth pump body P4. The output end of the fourth pump body P4 is connected to the tubular reactor R2. The tubular reactor R2 is connected to a 75℃ hot water inlet H10. The hot water inlet H10 is connected to a fifth pump body P5. The output end of the fifth pump body P5 is connected to a hot water supplier B1.

[0026] The concentrated liquid liquid outlet H9 is provided with a flow rate control component for controlling the flow rate. The solid-liquid mixture receiving tank V6 is provided with a liquid level detector for automatically sensing the liquid level.

[0027] The second crude product discharge port H5 is provided with a back pressure valve Z1. The crude product mixture enters the continuous post-treatment system through the second crude product discharge port H5. The back pressure valve Z1 adjusts the entering rate of the crude product in the scraped film evaporator T1. The material is first preheated to a set temperature before entering the scraped film evaporator T1. The pressure is negative so that the material starts to evaporate after entering the scraped film evaporator T1.

[0028] The scraped film evaporator T1 evaporates part of the dioxane in the entering crude product. The scraped film evaporator T1 is provided with a liquid level sensor. When the concentrated liquid collected from the bottom of the scraped film evaporator T1 reaches a certain amount, the pressure is adjusted to discharge the material from the concentrated liquid liquid outlet H9 into the solid-liquid mixture receiving tank V6. The material is then pumped into the tubular reactor R2 by the fourth pump body P4 through the concentrated liquid liquid outlet H9.

[0029] The liquid evaporated from the scraped film evaporator T1 is pumped into the dioxane receiving tank V3 by the third pump body P3 through the organic solvent outlet H8 for recycling.

[0030] Further, the tubular reactor R2 and the horizontal scraper centrifuge X1 are connected through the solid-liquid mixture inlet H11, the horizontal scraper centrifuge X1 is provided with a product aspirin discharge port H12 and a liquid outlet H13, the product aspirin discharge port H12 is connected with a product aspirin receiving tank V5, and the liquid outlet H13 is connected with a post-treatment liquid receiving tank V4.

[0031] The hot water in the hot water supply B1 enters the tubular reactor R2 through the hot water inlet H10 by the fourth pump body P4, recrystallizes the concentrated liquid to form a solid-liquid mixture, the solid-liquid mixture in the tubular reactor R2 enters the horizontal scraper centrifuge X1 through the solid-liquid mixture inlet H11 for spin filtration separation, the crystals in the horizontal scraper centrifuge X1 enter the product aspirin receiving tank V5 through the product aspirin discharge port H12 by the scraper, and the mixed liquid enters the post-treatment liquid receiving tank V4 through the liquid outlet H13.

[0032] Working principle: the acetic anhydride and salicylic acid in the acetic anhydride raw material tank V1 and the salicylic acid raw material tank V2 are fully dissolved with sufficient dioxane, and then pumped into the reaction system by the first pump body P1 and the second pump body P2 through the pipeline, the material enters the micro-channel reactor R1 under the action of the first pump body P1 and the second pump body P2, and then flows into the polytetrafluoroethylene pipeline in the heat exchanger E2 for a delay reaction, the micro-reaction part provides the required temperature for the reaction by the cold and hot well E1, the heated hot oil flows out from the hot oil liquid outlet H4, enters the micro-channel reactor R1, and then flows into the heat exchanger E2 through the pipeline, and finally flows back to the cold and hot well E1 from the hot oil liquid inlet H3. The back pressure valve Z1 is installed on the second crude product discharge port H5, the crude product mixed liquid enters the continuous post-treatment system through the second crude product discharge port H5, the back pressure valve Z1 adjusts the entering rate of the crude product in the scraped film evaporator T1, and the scraped film evaporator T1 is preheated to a set temperature before the material enters the scraped film evaporator T1, and the gas pressure is negative pressure, so that the material begins to evaporate after entering the scraped film evaporator T1. After the dioxane in the entering crude product is evaporated by the scraped film evaporator T1, a liquid level sensor is arranged in the scraped film evaporator T1, and when the concentrated liquid collected at the bottom of the scraped film evaporator T1 reaches a certain amount, the pressure is adjusted to discharge the material from the concentrated liquid liquid outlet H9, enter the solid-liquid mixture receiving tank V6, and then enter the tubular reactor R2 through the concentrated liquid liquid outlet H9 by the fourth pump body P4. The liquid evaporated in the scraped film evaporator T1 enters the dioxane receiving tank V3 through the organic solvent outlet H8 by the third pump body P3, and is recycled. The hot water in the hot water supplier B1 enters the tubular reactor R2 through the hot water inlet H10 by the fourth pump body P4, recrystallizes the concentrated liquid, forms a solid-liquid mixture, and the solid-liquid mixture in the tubular reactor R2 enters the horizontal scraped blade centrifuge X1 through the solid-liquid mixture inlet H11 for spin filtration separation, the crystals in the horizontal scraped blade centrifuge X1 enter the product aspirin receiving tank V5 through the product aspirin discharge port H12 by the scraper, and the mixed liquid enters the post-treatment liquid receiving tank V4 through the liquid outlet H13. The above product yield is 70% to 95%, and the purity is more than 99%, and the device can also be used for producing a one-step synthesis of acetaminophen and similar drugs that can be dissolved in organic solvents.

[0033] The above specific embodiments are only several optional embodiments of the present application, and based on the technical solutions of the present application and the related inspiration of the above embodiments, those skilled in the art can make various alternative improvements and combinations on the above specific embodiments.

Claims

1. A device for the synthesis of aspirin by microchannel continuous flow technology, characterized by, The pre-mixing system, the reaction system and the continuous post-treatment system are connected by polytetrafluoroethylene pipes or stainless steel pipes, and the pipes are provided with heat preservation layers and valves for controlling the material flow.

2. The device for synthesis of aspirin by microchannel continuous flow technology as claimed in claim 1, wherein, The pre-mixing system comprises an acetic anhydride raw material tank (V1), a salicylic acid raw material tank (V2), a first pump body (P1) and a second pump body (P2), the input end of the first pump body (P1) is communicated with the acetic anhydride raw material tank (V1), and the input end of the second pump body (P2) is communicated with the salicylic acid raw material tank (V2). The acetic anhydride raw material tank (V1) and the salicylic acid raw material tank (V2) have the same volume, and the flow rates of the first pump body (P1) and the second pump body (P2) are consistent and are 2 mL / min-20 mL / min, and the pressure is 0-1 bar.

3. The apparatus for synthesis of aspirin by microchannel continuous flow technology as claimed in claim 2, wherein, The reaction system comprises a micro-channel reactor (R1), a cold-hot well (E1) and a heat exchanger (E2), the cold-hot well (E1) is set to have a temperature of 70-80℃, the output ends of the first pump body (P1) and the second pump body (P2) are communicated with the micro-channel reactor (R1), the micro-channel reactor (R1) and the heat exchanger (E2) are communicated through a first crude product discharge port (H1), the heat exchanger (E2) is provided with a water inlet (H2), the heat exchanger (E2) and the cold-hot well (E1) are communicated through a hot oil liquid inlet (H3), and the micro-channel reactor (R1) and the cold-hot well (E1) are communicated through a hot oil liquid outlet (H4).

4. The apparatus for synthesis of aspirin by microchannel continuous flow technology as claimed in claim 3 wherein, The continuous post-treatment system comprises a scraped film evaporator (T1), a tubular reactor (R2) and a horizontal scraped blade centrifuge (X1), the scraped film evaporator (T1) and the heat exchanger (E2) are communicated through a second crude product discharge port (H5), the scraped film evaporator (T1) is provided with a steam inlet (H6), a condensed water outlet (H7) and an organic solvent outlet (H8), the organic solvent outlet (H8) is connected with a third pump body (P3), the organic solvent outlet (H8) and the input end of the third pump body (P3) are communicated, and the output end of the third pump body (P3) is connected with an oxygen hexacyclic ring receiving tank (V3).

5. The apparatus for synthesis of aspirin by microchannel continuous flow technology as claimed in claim 4, wherein, The scraper type thin film evaporator (T1) is provided with a concentrated liquid liquid outlet (H9), the concentrated liquid liquid outlet (H9) is provided with a flow rate control component for controlling the flow rate, one end of the concentrated liquid liquid outlet (H9) is connected with a solid-liquid mixture receiving tank (V6), the solid-liquid mixture receiving tank (V6) is provided with a liquid level detector for automatically sensing the liquid level, the solid-liquid mixture receiving tank (V6) is connected with a fourth pump body (P4), the solid-liquid mixture receiving tank (V6) is connected with the input end of the fourth pump body (P4), the output end of the fourth pump body (P4) is communicated with the tubular reactor (R2), the tubular reactor (R2) is connected with a hot water inlet (H10), the hot water inlet (H10) is connected with a fifth pump body (P5), the hot water inlet (H10) is communicated with the input end of the fifth pump body (P5), the output end of the fifth pump body (P5) is connected with a hot water supplier (B1).

6. The apparatus for synthesis of aspirin by microchannel continuous flow technology as claimed in claim 5 wherein, The tubular reactor (R2) and the horizontal scraper centrifuge (X1) are communicated through a solid-liquid mixture inlet (H11), the horizontal scraper centrifuge (X1) is provided with a product aspirin discharge port (H12) and a liquid outlet (H13), the product aspirin discharge port (H12) is connected with a product aspirin receiving tank (V5), and the liquid outlet (H13) is connected with a post-treatment liquid receiving tank (V4).

7. The apparatus for synthesis of aspirin by microchannel continuous flow technology as claimed in claim 6 wherein, The length of the pipeline in the heat exchanger (E2) is 30-50 m.

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