Method and device for continuously producing kung fu acid

Abstract

The invention relates to a method and a device for continuously producing kung fu acid, which are characterized in that a cis-trans-3-(2, 2-dichloro-3, 3, 3-trifluoropropyl)-2, 2-dimethyl cyclic carboxylate methanol solution and a strong alkali solution are respectively preheated by a preheater, then enter a high-efficiency mixer to be uniformly mixed, and then enter a dynamic tubular reactor, a static tubular reactor and a neutralization tubular reactor in sequence; the kung fu acid is obtained. The yield of the kung-fu acid is about 92%, the gas chromatography content of the product is about 98%, and the industrial safety production of the kung-fu acid is favorably realized.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical production, and in particular to a continuous production method and device of kung fu acid. Background Art

[0002] Kungfu acid is an important intermediate for the synthesis of pyrethroids such as highly effective chlorflucythrinate, and is widely used in the synthesis of technical drugs such as kungfu pyrethrin, bifenthrin, and tefluthrin.

[0003] The saponification reaction, the final step in the preparation of gongfu acid, is traditionally performed batchwise in a methanol system under atmospheric pressure. This slows the reaction rate and prolongs the reaction time, resulting in low crude gongfu acid yields, increased byproducts, and a significant decrease in product yield and quality. This prevents the use of recycled raw materials and generates significant amounts of waste. Furthermore, existing batch processes involve numerous equipment, including a saponification reactor, an acidification reactor, a two-in-one reactor, a primary refining reactor, a secondary refining reactor, and a three-in-one reactor. This equipment is complex and requires extensive operation. Patent Publication No. CN115636744A reports a method for synthesizing high-cis gongfu acid. The method involves forming a mixed solution of cis-3,3-dimethyl-4,6,6-trichloro-7,7,7-trifluoroheptanoate with an alcohol, dimethylformamide, and an alkane. The solution is cooled and a suspension of tert-butanol containing tert-butoxide is added to form a reaction system. Desolventization is then performed to obtain a mixed solution, which is then subjected to saponification, acidification, and purification to yield cis-gongfu acid. This method uses a batch reactor, which has a long reaction time, many reaction steps, and high reaction costs. Patent Publication No. CN105503582A reports a continuous production method for trifluoromonochlorochrysanthemic acid, which uses methyl benzoate and trifluorotrichloroethane as raw materials to obtain trifluoromonochlorochrysanthemic acid through addition, cyclization and saponification reactions. This method uses continuous pipeline equipment, and the cis-trans ratio of the product is not ideal, resulting in low product utilization.

[0004] The saponification reaction of gongfu acid in the prior art has a long reaction time, low production efficiency, and an unsatisfactory cis-trans ratio of the product. Therefore, a continuous production method of high-cis gongfu acid is urgently needed to reduce the amount of equipment used, improve the reaction efficiency, and increase production capacity. Summary of the Invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a method and device for continuously producing kung fu acid with high efficiency and high cis.

[0006] The technical solution adopted in the present invention is:

[0007] A reaction device for continuously producing kung fu acid mainly comprises: a cyclized product methanol premix solution storage tank (1), a strong alkali solution storage tank (2), a first preheater (3), a second preheater (4), a high-efficiency mixer (7), a dynamic tubular reactor (9), a static tubular reactor (10), a methanol solution storage tank (11), a flash kettle (12), a hydrochloric acid solution storage tank (14), a neutralization tubular reactor (16) and a receiving tank (17); the inlet and outlet of each storage tank and reactor are connected to a pipeline through a metering pump; the outlets of the cyclized product methanol premix solution storage tank (1) and the strong alkali solution storage tank (2) are connected to the first preheater (3), the second preheater ( The inlet of the first preheater (3) and the outlet of the second preheater (4) are connected to the inlet of the high-efficiency mixer (7); the outlet of the high-efficiency mixer (7) is connected to the inlet of the dynamic tubular reactor (9); the dynamic tubular reactor (9) is connected to the static tubular reactor (10), the static tubular reactor (10) is connected to the flash kettle (12), the lower outlet of the flash kettle (12) is connected to the neutralization tubular reactor (16), and the upper outlet of the flash kettle (12) is connected to the methanol solution storage tank (11); the outlet of the hydrochloric acid solution storage tank (14) is connected to the inlet of the neutralization tubular reactor (16), and the outlet of the neutralization tubular reactor (16) is connected to the receiving tank (17).

[0008] A method for continuously producing kung fu acid using the reaction device, wherein a methanol solution of a cyclized product (cis-trans-3-(2,2-dichloro-3,3,3-trifluoropropyl)-2,2-dimethyl cyclic carboxylate) and a strong base solution are preheated in a first preheater (3) and a second preheater (4), respectively, then enter a high-efficiency mixer (7) for uniform mixing, and then enter a dynamic tubular reactor (9), a static tubular reactor (10) and a neutralization tubular reactor (16) in sequence to obtain kung fu acid.

[0009] The mass ratio of the cyclized product (cis-trans-3-(2,2-dichloro-3,3,3-trifluoropropyl)-2,2-dimethylcyclocarboxylate) to methanol in the methanol solution is 1:0.1 to 1:4, preferably 1:1 to 1:3.

[0010] Wherein, the strong alkaline solution is selected from one of sodium hydroxide aqueous solution and potassium hydroxide aqueous solution.

[0011] The molar ratio of the cyclized product, the strong base and the hydrochloric acid is 1:1.5:4 to 1:5:10, preferably 1:2:4 to 1:3:7.

[0012] The two materials are preheated in the preheater at the same temperature, which is 30-100° C., preferably 40-90° C. The preheating time of the materials in the preheater is 3-10 minutes, preferably 3-8 minutes.

[0013] The flow rate of the material at each point in the pipeline is 5 to 80 L / min, preferably 20 to 70 L / min.

[0014] The material undergoes saponification reaction in dynamic and static tubular reactors, and the pipeline pressure in the dynamic and static tubular reactors is 0.1-3 MPa, preferably 0.2-1.2 MPa, the pipeline temperature in the dynamic tubular reactor is 70-200 ° C, preferably 70-150 ° C, and the pipeline residence time is 0.1-15 min, preferably 1-6 min. The pipeline temperature in the static tubular reactor is 100-200 ° C, preferably 110-180 ° C, and the pipeline residence time is 0.1-15 min, preferably 1-6 min.

[0015] The length of the dynamic and static tubular reactor pipes is 50 to 200 m, preferably 80 to 150 m, and the diameter of the pipes is 10 to 50 mm, preferably 20 to 50 mm.

[0016] The material undergoes a neutralization reaction with a hydrochloric acid solution in a neutralization tubular reactor. The pipe temperature in the neutralization tubular reactor is 15 to 70° C., preferably 20 to 30° C., and the pipe residence time is 0.5 to 40 minutes, preferably 10 to 30 minutes.

[0017] The neutralization tubular reactor has a length of 2-10 m, preferably 3-7 m, and a diameter of 10-80 cm, preferably 20-60 cm.

[0018] Furthermore, after the material completes the reaction through the static tubular reactor, the feed liquid is transferred to a flash kettle, and then the methanol is removed by flash evaporation. In the next step, the saponification reaction liquid is transported to the neutralization reaction tubular reactor through the fourth metering pump and neutralized with the hydrochloric acid solution transported by the fifth metering pump to precipitate the crude kung fu acid.

[0019] Furthermore, the reaction solution obtained by the present invention can be filtered to obtain a crude product, and the product can be further refined to obtain a high-purity refined product of Kung Fu acid.

[0020] Furthermore, the above-mentioned tubular reactor is one or a combination of several of a straight tubular reactor, a coil reactor, a multi-tubular reactor, a U-shaped tubular reactor and a ring tubular reactor; the purpose is to enable the raw materials to fully react in the tubular reactor, the flow rate and the composition, structure and length of the tubular reactor determine the reaction residence time, under the conditions determined by the tubular reactor, the reaction residence time is changed by adjusting the flow rate; under the conditions determined by the flow rate, the reaction residence time is changed by changing the composition, structure and length of the tubular reactor.

[0021] Furthermore, the tubular reactor is made of one or more of carbon steel, brass, stainless steel, monel, and Hastelloy alloy; this is intended to ensure corrosion resistance during the reaction of the raw materials within the tubular reactor. Furthermore, the tubular reactor is lined with a polyperfluoroolefin or carbon fiber lining. Due to its small size and simple internal structure, tubular reactors are more easily lined with other materials and are easier to process. Different materials exhibit significant variations in corrosion resistance during reactions, providing a wider selection of corrosion-resistant materials at the same equipment cost, thus helping to address corrosion issues within the reaction system.

[0022] Preferably, the material of the dynamic and static tubular reactors can be selected from one of 316L stainless steel tube, 304 stainless steel tube, 2205 stainless steel tube, and titanium; the material of the neutralization tubular reactor is a lined polytetrafluoroethylene tube.

[0023] Compared with the prior art, the advantages of the present invention are:

[0024] The present invention designs a method for synthesizing high-purity kung fu acid using cis-trans-3-(2,2-dichloro-3,3,3-trifluoropropyl)-2,2-dimethyl cyclocarboxylate as a raw material, using a continuous reaction apparatus without the addition of a catalyst. The production equipment in the prior art is too large and takes up too much space. The continuous reaction apparatus provided by the present invention is small in size, can significantly improve space utilization, and is easier to operate and more efficient. Furthermore, the inventors have discovered that preheating the reaction system before the reaction can reduce the content of by-products, thereby improving the reaction yield; adding a certain amount of methanol during the reaction can significantly shorten the reaction time and also play a role in suppressing side reactions, resulting in a lower content of by-products; after the reaction is completed, excess methanol is removed by high-temperature latent heat flash evaporation, which facilitates the sufficient precipitation of the product in the next acidification step, saves energy consumption, and is more conducive to industrial production.

[0025] The process of the present invention utilizes the advantages of a tubular reactor, such as minimal back-mixing, to overcome the long production cycle and complex process steps associated with conventional batch reactors for producing kung fu acid. This process enables continuous production and automated process control, resulting in efficient and safe production at low cost. Furthermore, the process shortens the reaction time, minimizes side reactions, and produces a high-purity product. The kung fu acid yield of the present invention is over 92%, and the product content is greater than 98%. This achieves industrialized and safe production of kung fu acid. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of a reaction device for continuously producing kung fu acid according to the present invention;

[0027] Figure 1In the figure, 1 is a storage tank for the methanol premixed solution of the cyclized product, 2 is a storage tank for the strong base solution, 3 is a first preheater, 4 is a second preheater, 5 is a first metering pump, 6 is a second metering pump, 7 is a high-efficiency mixer, 8 is a third metering pump, 9 is a dynamic tubular reactor, 10 is a static tubular reactor, 11 is a methanol solution storage tank, 12 is a flash kettle, 13 is a fourth metering pump, 14 is a hydrochloric acid solution storage tank, 15 is a fifth metering pump, 16 is a neutralization tubular reactor, and 17 is a receiving tank.

[0028] Figure 2 Schematic diagram of gas chromatography of the product of Example 1. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to specific embodiments, but the protection scope of the present invention is not limited thereto.

[0030] In the following examples, the apparatus used for the continuous production of kung fu acid is as follows: Figure 1 As shown, the device comprises: a cyclized product methanol premix solution storage tank (1), a strong alkali solution storage tank (2), a first preheater (3), a second preheater (4), a high-efficiency mixer (7), a dynamic tubular reactor (9), a static tubular reactor (10), a methanol solution storage tank (11), a flash kettle (12), a hydrochloric acid solution storage tank (14), a neutralization tubular reactor (16) and a receiving tank (17); the inlet and outlet of each storage tank and reactor are connected to the pipeline through a metering pump; the outlets of the cyclized product methanol premix solution storage tank (1) and the strong alkali solution storage tank (2) are connected to the inlet of the first preheater (3) and the second preheater (4), respectively. The outlets of the first preheater (3) and the second preheater (4) are connected to the inlet of the high-efficiency mixer (7); the outlet of the high-efficiency mixer (7) is connected to the inlet of the dynamic tubular reactor (9); the dynamic tubular reactor (9) is connected to the static tubular reactor (10), the static tubular reactor (10) is connected to the flash kettle (12), the lower outlet of the flash kettle (12) is connected to the neutralization tubular reactor (16), and the upper outlet of the flash kettle (12) is connected to the methanol solution storage tank (11); the outlet of the hydrochloric acid solution storage tank (14) is connected to the inlet of the neutralization tubular reactor (16), and the outlet of the neutralization tubular reactor (16) is connected to the receiving tank (17).

[0031] The working principle of the present invention is as follows: a methanol solution of a cyclized product (cis-trans-3-(2,2-dichloro-3,3,3-trifluoropropyl)-2,2-dimethyl cyclocarboxylate) and a strong base solution are preheated in a first preheater (3) and a second preheater (4), uniformly mixed in a high-efficiency mixer (7), and then sequentially enter a dynamic tubular reactor (9), a static tubular reactor (10), and a neutralization tubular reactor (16) to obtain kung fu acid.

[0032] During operation of the present invention, the methanol solution of the cyclized product in the cyclized product methanol premix solution storage tank (1) and the strong alkali solution in the strong alkali solution storage tank (2) are respectively preheated in a tubular manner by passing through a first preheater (3) and a second preheater (4). The purpose of preheating is, firstly, to accurately control the reaction time and fully utilize the excess heat of the reaction; secondly, to increase the reaction starting temperature, reduce the length and corrosion of the high-temperature reaction pipeline, and further reduce the content of by-products; the preheating temperature range is: room temperature < preheating temperature < reaction temperature. Then, the first metering pump (5) and the second metering pump (6) are transported at a certain mass ratio, and mixed evenly by the high-efficiency mixer (7). Then, the third metering pump (8) is continuously transported to the dynamic tubular reactor (9) and the static tubular reactor (10) for reaction. After the reaction is completed, the feed liquid is transferred to the flash evaporator (12). The methanol removed by flash evaporation is transferred to the methanol solution storage tank (11). Next, the saponification reaction feed liquid is transported to the neutralization reaction tubular reactor (16) by the fourth metering pump (13) and neutralized with the hydrochloric acid solution transported by the fifth metering pump (15) to precipitate the crude product of kung fu acid. Further, the precipitated crude product is transferred to the filter to obtain the crude product. The filtered crude product is transferred to the refining system to complete the refining to obtain the product kung fu acid, and the purity and yield of the product are calculated.

[0033] Reaction formula:

[0034]

[0035]

[0036] Example 1

[0037] The reaction device structure is as follows Figure 1 In this embodiment, the length of the dynamic and static tubular reactors is 100 m, and the diameter is 30 mm. The length of the neutralization tubular reactor is 6 m, and the diameter is 50 cm.

[0038] Prepare in advance the cyclized product (1000 kg, 3.41 kmol), methanol (1400 kg), strong base solution: 40% potassium hydroxide solution (955.6 kg, potassium hydroxide content is 6.82 kmol), hydrochloric acid solution: 35% hydrochloric acid solution (400 kg, hydrogen chloride content is 3.84 kmol).

[0039] The cyclized product and methanol are stored in a cyclized product-methanol premixed solution storage tank (1), the strong base solution is stored in a strong base solution storage tank (2), and the hydrochloric acid solution is stored in a hydrochloric acid solution storage tank (14).

[0040] The solutions in the cyclized product methanol premix solution storage tank (1) and the strong base solution storage tank (2) are respectively preheated to 85°C by a first preheater (3) and a second preheater (4), and then transported by a first metering pump (5) and a second metering pump (6) at a feed mass ratio of 3.01:1, and mixed uniformly by a high-efficiency mixer (7). The solutions are continuously transported to a dynamic tubular reactor (9) by a third metering pump (8) at a feed rate of 30L / min. The reaction temperature is 90±5°C, the pipeline pressure is 0.2MPa, and the pipeline residence time is 3±1min. , then enters the static tubular reactor (10), the reaction temperature is 160±5℃, the pipeline pressure is 1.2MPa, and the pipeline residence time is 5±1min. After the reaction is completed, the feed liquid is transferred to the flash kettle (12), and the methanol removed by flash evaporation is transferred to the methanol solution storage tank (11). The saponification reaction feed liquid is transported to the neutralization reaction tubular reactor (16) at a feed rate of 30L / min through the fourth metering pump (13), and is neutralized with the 35% hydrochloric acid solution added by the fifth metering pump (15). The reaction temperature is 25℃ and the pipeline residence time is 30min. After the reaction is completed, the feed liquid is transferred to the filter to obtain a crude product. The filtered crude product is transferred to the refining system to complete the refining. A total of 784.8kg of white solid kung fu acid is obtained from the discharge pipeline. The reaction yield is 92.87% based on the cyclized product. According to the GC analysis content, the product purity is 97.94%.

[0041] Example 2

[0042] The reaction device structure is as follows Figure 1 The length of the dynamic and static tubular reactors in this embodiment is 110 m, and the diameter is 35 mm. The length of the neutralization tubular reactor is 6 m, and the diameter is 50 cm.

[0043] Prepare in advance the cyclized product (1000 kg, 3.41 kmol), methanol (1400 kg), strong base solution: 40% potassium hydroxide solution (1099.0 kg, potassium hydroxide content is 7.85 kmol), hydrochloric acid solution: 35% hydrochloric acid solution (400 kg, hydrogen chloride content is 3.84 kmol).

[0044] The cyclized product and methanol are stored in a cyclized product-methanol premixed solution storage tank (1), the strong base solution is stored in a strong base solution storage tank (2), and the hydrochloric acid solution is stored in a hydrochloric acid solution storage tank (14).

[0045] The solutions in the cyclized methanol premix solution storage tank (1) and the strong base solution storage tank (2) are preheated to 85°C through the first preheater (3) and the second preheater (4) respectively, and then transported through the first metering pump (5) and the second metering pump (6) at a mass ratio of 3.01:1, and mixed evenly through the high-efficiency mixer (7). At a feed rate of 31L / min, the solutions are continuously transported to the dynamic tubular reactor (9) through the third metering pump (8), the reaction temperature is 100±5°C, the pipeline pressure is 0.2MPa, the pipeline residence time is 3±1min, and then enter the static The reaction was carried out in a tubular reactor (10) at a reaction temperature of 150±5°C, a pipeline pressure of 1.2 MPa, and a pipeline residence time of 5±1 min. After the reaction was completed, the feed liquid was transferred to a flash evaporator (12), and the methanol removed by flash evaporation was transferred to a methanol solution storage tank (11). The saponification reaction liquid was transported to a neutralization reaction tubular reactor (16) at a feed rate of 30 L / min via a fourth metering pump (13), and neutralized with 620 kg of 35% hydrochloric acid solution added via a fifth metering pump (15). The reaction temperature was 25°C, and the pipeline residence time was 40 min. After the reaction was completed, the feed liquid was transferred to a filter to obtain a crude product. The filtered crude product was transferred to a refining system for refining. A total of 774.9 kg of white solid kung fu acid was obtained from the discharge pipeline. The reaction yield was 92.12% based on the cyclized product. According to GC analysis, the product purity was 98.36%.

[0046] Example 3

[0047] The reaction device structure is as follows Figure 1 In this embodiment, the length of the dynamic and static tubular reactors is 100 m, and the diameter is 40 mm. The length of the neutralization tubular reactor is 6 m, and the diameter is 60 cm.

[0048] Prepare in advance the cyclized product (1000 kg, 3.41 kmol), methanol (1400 kg), strong base solution: 40% potassium hydroxide solution (955.6 kg, potassium hydroxide content is 6.82 kmol), hydrochloric acid solution: 35% hydrochloric acid solution (400 kg, hydrogen chloride content is 3.84 kmol).

[0049] The cyclized product and methanol are stored in a cyclized product-methanol premixed solution storage tank (1), the strong base solution is stored in a strong base solution storage tank (2), and the hydrochloric acid solution is stored in a hydrochloric acid solution storage tank (14).

[0050] The solutions in the cyclized methanol premix solution storage tank (1) and the strong base solution storage tank (2) are respectively preheated to 90°C by a first preheater (3) and a second preheater (4), and then transported by a first metering pump (5) and a second metering pump (6) at a mass ratio of 3.01:1, and mixed uniformly by a high-efficiency mixer (7). The solutions are continuously transported to a dynamic tubular reactor (9) by a third metering pump (8) at a feed rate of 30L / min. The reaction temperature is 110±5°C, the pipeline pressure is 0.2MPa, the pipeline residence time is 3±1min, and then enter the static tube reactor. The reaction was carried out in a reactor (10) with a reaction temperature of 170±5°C, a pipeline pressure of 1.2 MPa, and a pipeline residence time of 5±1 min. After the reaction was completed, the feed liquid was transferred to a flash evaporator (12), and the methanol removed by flash evaporation was transferred to a methanol solution storage tank (11). The saponification reaction feed liquid was transported to a neutralization reaction tubular reactor (16) at a feed rate of 30 L / min via a fourth metering pump (13), and neutralized with 600 kg of 35% hydrochloric acid solution added via a fifth metering pump (15). The reaction temperature was 25°C, and the pipeline residence time was 30 min. After the reaction was completed, the feed liquid was transferred to a filter to obtain a crude product. The filtered crude product was transferred to a refining system for refining. A total of 791.5 kg of white solid Kung Fu acid was obtained from the discharge pipeline. The reaction yield was 93.02% based on the cyclized product. According to GC analysis, the product purity was 97.23%.

[0051] Example 4

[0052] The reaction device structure is as follows Figure 1 The length of the dynamic and static tubular reactors in this embodiment is 110 m, and the diameter is 50 mm. The length of the neutralization tubular reactor is 6 m, and the diameter is 60 cm.

[0053] Prepare in advance the cyclized product (1000 kg, 3.41 kmol), methanol (1400 kg), strong base solution: 40% potassium hydroxide solution (1194.4 kg, potassium hydroxide content is 8.53 kmol), hydrochloric acid solution: 35% hydrochloric acid solution (400 kg, hydrogen chloride content is 3.84 kmol).

[0054] The cyclized product and methanol are stored in a cyclized product-methanol premixed solution storage tank (1), the strong base solution is stored in a strong base solution storage tank (2), and the hydrochloric acid solution is stored in a hydrochloric acid solution storage tank (14).

[0055] The solutions in the cyclized methanol premix solution storage tank (1) and the strong base solution storage tank (2) are preheated to 85°C through the first preheater (3) and the second preheater (4) respectively, and then transported through the first metering pump (5) and the second metering pump (6) at a mass ratio of 3.01:1, and mixed evenly through the high-efficiency mixer (7). At a feed rate of 31.9L / min, the solutions are continuously transported to the dynamic tubular reactor (9) through the third metering pump (8), the reaction temperature is 80±5°C, the pipeline pressure is 0.2MPa, the pipeline residence time is 3±1min, and then enter the static The reaction was carried out in a tubular reactor (10) at a reaction temperature of 130±5°C, a pipeline pressure of 1.2 MPa, and a pipeline residence time of 5±1 min. After the reaction was completed, the feed liquid was transferred to a flash evaporator (12), and the methanol removed by flash evaporation was transferred to a methanol solution storage tank (11). The saponification reaction liquid was transported to a neutralization reaction tubular reactor (16) at a feed rate of 30 L / min via a fourth metering pump (13), and neutralized with 640 kg of 35% hydrochloric acid solution added via a fifth metering pump (15). The reaction temperature was 25°C, and the pipeline residence time was 40 min. After the reaction was completed, the feed liquid was transferred to a filter to obtain a crude product. The filtered crude product was transferred to a refining system for refining. A total of 784.1 kg of white solid kung fu acid was obtained from the discharge pipeline. The reaction yield was 92.72% based on the cyclized product. According to GC analysis, the product purity was 97.84%.

[0056] Example 5

[0057] The reaction device structure is as follows Figure 1 The length of the dynamic and static tubular reactors in this embodiment is 130 m, and the diameter is 45 mm. The length of the neutralization tubular reactor is 5 m, and the diameter is 50 cm.

[0058] Prepare in advance the cyclized product (1000 kg, 3.41 kmol), methanol (1400 kg), strong base solution: 30% sodium hydroxide solution (921.3 kg, sodium hydroxide content is 6.91 kmol), hydrochloric acid solution: 35% hydrochloric acid solution (400 kg, hydrogen chloride content is 3.84 kmol).

[0059] The cyclized product and methanol are stored in a cyclized product-methanol premixed solution storage tank (1), the strong base solution is stored in a strong base solution storage tank (2), and the hydrochloric acid solution is stored in a hydrochloric acid solution storage tank (14).

[0060] The solutions in the cyclized product methanol premix solution storage tank (1) and the strong base solution storage tank (2) are respectively preheated to 85°C by a first preheater (3) and a second preheater (4), and then transported by a first metering pump (5) and a second metering pump (6) at a feed mass ratio of 3.01:1, and mixed uniformly by a high-efficiency mixer (7). The solutions are continuously transported to a dynamic tubular reactor (9) by a third metering pump (8) at a feed rate of 30L / min. The reaction temperature is 90±5°C, the pipeline pressure is 0.2MPa, and the pipeline residence time is 3±1min. , then enters the static tubular reactor (10), the reaction temperature is 160±5℃, the pipeline pressure is 1.2MPa, and the pipeline residence time is 5±1min. After the reaction is completed, the feed liquid is transferred to the flash kettle (12), and the methanol removed by flash evaporation is transferred to the methanol solution storage tank (11). The saponification reaction feed liquid is transported to the neutralization reaction tubular reactor (16) at a feed rate of 30L / min through the fourth metering pump (13), and is neutralized with the 35% hydrochloric acid solution added by the fifth metering pump (15). The reaction temperature is 25℃ and the pipeline residence time is 30min. After the reaction is completed, the feed liquid is transferred to the filter to obtain a crude product. The filtered crude product is transferred to the refining system to complete the refining. A total of 785.5kg of white solid kung fu acid is obtained from the discharge pipeline. The reaction yield is 92.26% based on the cyclized product. According to the GC analysis content, the product purity is 97.18%.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A reaction device for continuously producing kung fu acid, characterized in that: Mainly include: A cyclized product methanol premixed solution storage tank (1), a strong alkali solution storage tank (2), a first preheater (3), a second preheater (4), a high-efficiency mixer (7), a dynamic tubular reactor (9), a static tubular reactor (10), a methanol solution storage tank (11), a flash kettle (12), a hydrochloric acid solution storage tank (14), a neutralization tubular reactor (16) and a receiving tank (17); the inlet and outlet of each storage tank and reactor are connected to a pipeline through a metering pump; the outlets of the cyclized product methanol premixed solution storage tank (1) and the strong alkali solution storage tank (2) are respectively connected to the inlet of the first preheater (3) and the second preheater (4); the outlets of the first preheater (11) and the strong alkali solution storage tank (2) are respectively connected to the inlet of the first preheater (3) and the second preheater (4); (3), the outlet of the second preheater (4) is connected to the inlet of the high-efficiency mixer (7); the outlet of the high-efficiency mixer (7) is connected to the inlet of the dynamic tubular reactor (9); the dynamic tubular reactor (9) is connected to the static tubular reactor (10), the static tubular reactor (10) is connected to the flash kettle (12), the lower outlet of the flash kettle (12) is connected to the neutralization tubular reactor (16), and the upper outlet of the flash kettle (12) is connected to the methanol solution storage tank (11); the outlet of the hydrochloric acid solution storage tank (14) is connected to the inlet of the neutralization tubular reactor (16), and the outlet of the neutralization tubular reactor (16) is connected to the receiving tank (17).

2. A method for continuously producing kung fu acid using the reaction apparatus according to claim 1, characterized in that: The methanol solution of the cyclized product (cis-trans-3-(2,2-dichloro-3,3,3-trifluoropropyl)-2,2-dimethyl cyclocarboxylate) and the strong base solution are preheated in a first preheater (3) and a second preheater (4) respectively, then enter a high-efficiency mixer (7) for uniform mixing, and then enter a dynamic tubular reactor (9), a static tubular reactor (10) and a neutralization tubular reactor (16) in sequence to obtain kung fu acid.

3. The method for continuously producing kung fu acid according to claim 2, wherein: The temperatures of the two materials preheated in the preheater are kept the same, the preheating temperature is 30-100° C., and the residence time of the materials in the preheater is 3-10 minutes.

4. The method for continuously producing kung fu acid according to claim 2, wherein: The reaction liquid feed flow rate is 5 to 80 L / min.

5. The method for continuously producing kung fu acid according to claim 2, wherein: The mass ratio of the cyclized product to methanol is 1:0.1-4.

6. The method for continuously producing kung fu acid according to claim 3-5, characterized in that: The material undergoes a saponification reaction in dynamic and static tubular reactors. The length of the dynamic and static tubular reactor pipes is 50 to 200 meters, the pipe diameter is 10 to 50 mm, the pipe pressure in the dynamic and static tubular reactors is 0.1 to 3 MPa, the pipe temperature in the dynamic tubular reactor is 70 to 200° C., the pipe residence time is 0.1 to 15 minutes, and the pipe temperature in the static tubular reactor is 100 to 200° C., and the pipe residence time is 0.1 to 15 minutes.

7. The method for continuously producing kung fu acid according to claim 2, wherein: The molar ratio of the cyclized product, the strong base and the hydrochloric acid is 1:1.5:4 to 1:5:

10.

8. The method for continuously producing kung fu acid according to claim 7, wherein: The material undergoes a neutralization reaction with a hydrochloric acid solution in a neutralization tubular reactor. The neutralization tubular reactor has a pipe length of 2 to 10 meters, a pipe diameter of 10 to 80 cm, a pipe temperature of 15 to 70° C., and a pipe residence time of 0.5 to 40 minutes.

Images