Hofmann degradation reaction system for continuous production of cyclopropylamine and production method

Abstract

The invention relates to a Hofmann degradation reaction system for continuous production of cyclopropylamine and a production method. The method comprises the following steps: pumping a cyclopropanecarboxamide aqueous solution (containing sodium chloride) produced in an amination reaction section and a sodium hydroxide / sodium hypochlorite mixed solution to respective heat exchangers, mixing through an efficient mixer I at a certain temperature, and then feeding into a substitution reactor; the mixed material enters a high-efficiency mixer II through an outlet of the substitution reactor, is mixed with a quantitative sodium hydroxide solution, then enters a Hofmann degradation reactor, and enters a reaction liquid receiving tank after the mixed material is completely reacted in the Hofmann degradation reactor; the reacted material is subjected to gas-liquid separation through a reaction liquid receiving tank and then enters a continuous rectification system to be rectified, and a cyclopropylamine product is obtained. According to the invention, the complete continuous production of the Hofmann degradation reaction of the cyclopropylamine can be realized, the production efficiency is high, the energy consumption is low, and the product quality is stable.

Description

Technical Field

[0001] The invention belongs to the field of chemical production, and in particular relates to a Hofmann degradation reaction system and a production method for continuous production of cyclopropylamine. Background Art

[0002] Cyclopropylamine is an important chemical intermediate and an important raw material for the production of quinolone antibiotics (ciprofloxacin, sparfloxacin, enrofloxacin), anti-human immunoviral drugs and chemical herbicides (ciprofloxacin, ciprofloxacin, etc.).

[0003] Hofmann degradation is the last step of the current cyclopropylamine production process. This step includes three processes: substitution reaction, elimination (rearrangement) reaction and hydrolysis reaction. At present, the mainstream production processes are intermittent process and continuous process. The intermittent reaction is to carry out the substitution reaction at about (0±10)℃ for 1-2h, and then add liquid alkali to heat up and carry out rearrangement and hydrolysis reaction; the continuous reaction is to carry out the degradation reaction under the temperature condition of (-15~30)℃ (patent number: ZL201711492500.1); both processes are carried out at about (0±10)℃. Under this temperature condition, the solubility of cyclopropylcarboxamide solution is low, and solids will precipitate and suspend on the liquid surface. Above, in the continuous production process, sufficient mixing cannot be achieved, resulting in the concentration of cyclopropylcarboxamide in the reactor being locally too high or too low, causing an increase in urea or nitrile by-products, thereby reducing the product yield and affecting the product quality; in addition, excessive sodium hypochlorite has an effect on the oxidation of cyclopropylcarboxamide raw materials, intermediates and target product cyclopropylamine. Depending on the process conditions, it is crucial to select an appropriate amount of sodium hypochlorite; secondly, in the study of Hofmann degradation continuous reaction, the reaction temperature has a greater influence on the reaction time. By increasing the reaction temperature, the reaction time can be shortened from the original 1~2h to 4~10min, which has a greater impact on the structure, equipment and engineering cost of the Hofmann degradation reactor.

[0004]

[0005] Hofmann degradation mechanism in the production of cyclopropylamine.

[0006] In view of the various technical problems raised above, developing a Hofmann degradation reaction system and production method for continuous production of cyclopropylamine is of great significance to improving the production efficiency of cyclopropylamine products and upgrading the level of production equipment. Summary of the invention

[0007] In order to solve the technical problems in the Hofmann degradation reaction process of continuous production of cyclopropylamine, the object of the present invention is to provide a Hofmann degradation reaction production system for continuous production of cyclopropylamine, which can be used to more efficiently and continuously produce cyclopropylamine products.

[0008] The Hofmann degradation reaction system for continuous production of cyclopropylamine provided by the present invention comprises: a reaction module, a feeding module and an automatic control module; The reaction module comprises a substitution reactor, a high-efficiency mixer 1, a Hofmann degradation reactor, a high-efficiency mixer 2, and a reaction liquid receiving tank; the outlet of the high-efficiency mixer 1 is connected to the bottom of the substitution reactor through a pipeline, the upper part of the substitution reactor is connected to the high-efficiency mixer 2 through a pipeline, the high-efficiency mixer 2 is connected to the bottom of the Hofmann degradation reactor through a pipeline, the upper part of the Hofmann degradation reactor is connected to the reaction liquid receiving tank through a pipeline, and the bottom of the reaction liquid receiving tank is connected to the distillation system through a pipeline; the substitution reactor and the Hofmann degradation reactor are both tubular reactors with a shell side and a tube side, the shell side of the reactor is a heat medium, and the tube side of the reactor is a material reaction medium; the top of the reaction liquid receiving tank is provided with safety accessories and an exhaust gas discharge port.

[0009] The feeding module comprises pump 1, pump 2, pump 3, heat exchanger 1 and heat exchanger 2. Sodium hydroxide solution is transported to high-efficiency mixer 2 through pump 1, sodium hydroxide / sodium hypochlorite mixed solution is transported to heat exchanger 2 through pump 2, the outlet of heat exchanger 2 is connected with high-efficiency mixer 1 through a pipeline, cyclopropylcarboxamide aqueous solution is transported to heat exchanger 1 through pump 3, the outlet of heat exchanger 1 is connected with high-efficiency mixer 1 through a pipeline, and pneumatic regulating valves and mass flow meters are arranged on the outlet pipelines of pump 1, pump 2 and pump 3.

[0010] The automatic control module includes a pneumatic regulating valve on the outlet pipeline of pump 1 and a mass flow meter for automatically regulating the feeding amount of sodium hydroxide solution, a pneumatic regulating valve on the outlet pipeline of pump 2 and a mass flow meter for automatically regulating the feeding amount of sodium hydroxide / sodium hypochlorite mixed solution, and a pneumatic regulating valve on the outlet pipeline of pump 3 and a mass flow meter for automatically regulating the feeding amount of cyclopropylcarboxamide aqueous solution; pneumatic regulating valves are arranged on the heat medium inlet pipelines of heat exchanger 1 and heat exchanger 2, pneumatic shut-off valves are arranged on the heat medium outlet pipelines, a temperature transmitter is arranged inside heat exchanger 1, and a thermocouple temperature transmitter is arranged on the material outlet pipeline of heat exchanger 2; pneumatic regulating valves are arranged on the heat medium inlet pipelines of the replacement reactor and the Hofmann degradation reactor, pneumatic shut-off valves are arranged on the heat medium outlet pipelines, and temperature transmitters are arranged on the material outlet pipelines of the replacement reactor and the Hofmann degradation reactor; the tank body of the reaction liquid receiving tank is provided with a liquid level transmitter and a pressure transmitter, and a pneumatic regulating valve is arranged on the discharge pipeline at the bottom of the reaction liquid receiving tank; The data transmission and control of the pneumatic regulating valve, pneumatic shut-off valve, temperature transmitter, pressure transmitter and liquid level transmitter are all connected to the automatic control system in the computer, and the automatic control system adopts the control technology of the distributed control system (DCS).

[0011] The heat exchanger of the equipment described in the present invention is a kettle structure, provided with an anchor stirring device, and the stirring speed is 60-200 rad / min.

[0012] The safety accessory described in the present invention consists of a bursting disc and a safety valve. The bursting disc is located at the top of the reaction liquid receiving tank and is connected through a pipeline. The safety valve is located behind the bursting disc. The discharge outlet of the safety valve is connected to the safety discharge buffer tank through a pipeline. A back pressure valve is arranged on the exhaust gas discharge outlet pipeline at the top of the reaction liquid receiving tank, and the exhaust gas discharge pipeline is connected to the exhaust gas treatment system through the back pressure valve.

[0013] The heat medium described in the present invention is steam, hot water or heat transfer oil.

[0014] In the Hofmann degradation reaction production method, the temperature of the cyclopropylcarboxamide aqueous solution after heat exchange in the first heat exchanger is 40-60° C., and the temperature of the sodium hydroxide / sodium hypochlorite mixed solution after heat exchange in the second heat exchanger is 40-60° C.; In the Hofmann degradation reaction production method, the molar ratio of cyclopropylcarboxamide to sodium hypochlorite feed is 1:(1-1.1), the molar ratio of sodium hypochlorite to sodium hydroxide in the sodium hydroxide / sodium hypochlorite mixed solution is 1:(1-2), and the molar ratio of sodium hydroxide molar amount to cyclopropylcarboxamide in the sodium hydroxide solution is (1-2):1.

[0015] In the Hofmann degradation reaction production method, the temperature of the substitution reactor is 40-80°C, and the residence time of the mixed material in the substitution reactor is 2-8 minutes; the temperature of the Hofmann degradation reactor is 80-100°C, and the residence time of the mixed material in the Hofmann degradation reactor is 4-10 minutes.

[0016] The high-efficiency mixer 1 and the high-efficiency mixer 2 of the equipment described in the present invention are fluid mixers with a mixing efficiency greater than 97%.

[0017] The equipment replacement reactor and the Hofman degradation reactor of the present invention are fully mixed tank reactors (one-stage or multi-stage series connection) or plug flow tubular reactors, preferably plug flow tubular reactors.

[0018] In summary, the beneficial technical effects of this application are: The invention solves the problem that the cyclopropylcarboxamide aqueous solution cannot be fully mixed due to crystallization of the cyclopropylcarboxamide aqueous solution by increasing the feed temperature of the cyclopropylcarboxamide aqueous solution and premixing by stirring in a heat exchanger; the sodium hypochlorite feed amount is reasonably optimized to prevent excessive sodium hypochlorite from oxidizing the product cyclopropylamine; the operating temperature of the Hofmann degradation reactor is improved, the continuous reaction time is shortened, and the continuous production efficiency of cyclopropylamine is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a diagram of a pipeline reactor device of the present invention; Figure numerals: 1 heat exchanger one, 2 heat exchanger two, 3 high-efficiency mixer one, 4 replacement reactor, 5 high-efficiency mixer two, 6 Hofman degradation reactor, 7 reaction liquid receiving tank, 8 pump one, 9 pump two, 10 pump three, 11 mass flow meter one, 13 mass flow meter two, 15 mass flow meter three, 12 pneumatic control valve one, 14 pneumatic control valve two, 16 pneumatic control valve three, 21 pneumatic control valve four, 24 pneumatic control valve five, 27 pneumatic control valve six, 30 pneumatic control valve seven, 34 pneumatic control valve eight, 17 safety valve, 18 bursting disc, 20 pneumatic cut-off valve one, 23 pneumatic cut-off valve two, 26 pneumatic cut-off valve three, 29 pneumatic cut-off valve four, 19 temperature transmitter one, 22 temperature transmitter two, 25 temperature transmitter three, 28, temperature transmitter four, 31 back pressure valve, 32 pressure transmitter, 33 liquid level transmitter. DETAILED DESCRIPTION

[0020] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings.

[0021] Embodiment 1, as Figure 1 As shown, the present invention provides a Hofmann degradation reaction system for continuous production of cyclopropylamine, the system comprising: a reaction module, a feeding module and an automatic control module; The reaction module includes a replacement reactor 4, a high-efficiency mixer 3, a Hofmann degradation reactor 6, a high-efficiency mixer 2 5, and a reaction liquid receiving tank 7; the outlet of the high-efficiency mixer 3 is connected to the bottom of the replacement reactor 4 through a pipeline, the upper part of the replacement reactor 4 is connected to the high-efficiency mixer 2 5 through a pipeline, the high-efficiency mixer 2 5 is connected to the bottom of the Hofmann degradation reactor 6 through a pipeline, the upper part of the Hofmann degradation reactor 6 is connected to the reaction liquid receiving tank 7 through a pipeline, and the bottom of the reaction liquid receiving tank 7 is connected to the distillation system through a pipeline; the replacement reactor 4 and the Hofmann degradation reactor 6 are both tubular reactors with a shell side and a tube side, the shell side of the reactor is a heat medium, and the tube side of the reactor is a material reaction medium; the top of the reaction liquid receiving tank 7 is provided with safety accessories and an exhaust gas discharge port.

[0022] The feeding module includes pump 1 8, pump 2 9, pump 3 10, heat exchanger 1, and heat exchanger 2 2. The sodium hydroxide solution is transported to the high-efficiency mixer 2 5 through pump 1 8, and the sodium hydroxide / sodium hypochlorite mixed solution is transported to the heat exchanger 2 2 through pump 2 9. The outlet of the heat exchanger 2 2 is connected to the high-efficiency mixer 3 through a pipeline. The cyclopropylcarboxamide aqueous solution is transported to the heat exchanger 1 through pump 3 10, and the outlet of the heat exchanger 1 is connected to the high-efficiency mixer 3 through a pipeline. Pneumatic regulating valves and mass flow meters are provided on the outlet pipelines of pump 1 8, pump 2 9 and pump 3 10.

[0023] The automatic control module includes a pneumatic regulating valve 12 on the outlet pipeline of pump 18 and a mass flow meter 11 for automatically regulating the feeding amount of sodium hydroxide solution, a pneumatic regulating valve 2 14 on the outlet pipeline of pump 29 and a mass flow meter 2 13 for automatically regulating the feeding amount of sodium hydroxide / sodium hypochlorite mixed solution, a pneumatic regulating valve 3 16 on the outlet pipeline of pump 3 10 and a mass flow meter 3 15 for automatically regulating the feeding amount of cyclopropylcarboxamide aqueous solution; a pneumatic regulating valve 4 21 and a pneumatic regulating valve 5 24 are respectively arranged on the heat medium inlet pipelines of heat exchanger 1 and heat exchanger 2, and a pneumatic shut-off valve 1 20 and a pneumatic shut-off valve 2 2 are respectively arranged on the heat medium outlet pipelines. 3. A temperature transmitter 19 is provided inside the heat exchanger 1, and a temperature transmitter 22 is provided on the material outlet pipeline of the heat exchanger 2; a pneumatic regulating valve 6 27 and a pneumatic regulating valve 7 30 are provided on the heat medium inlet pipelines of the replacement reactor 4 and the Hoffman degradation reactor 6, respectively, and a pneumatic shut-off valve 3 26 and a pneumatic shut-off valve 4 29 are provided on the heat medium outlet pipelines, and a temperature transmitter 3 25 and a temperature transmitter 4 28 are provided on the material outlet pipelines of the replacement reactor 4 and the Hoffman degradation reactor 6, respectively; a liquid level transmitter 33 and a pressure transmitter 32 are provided on the tank body of the reaction liquid receiving tank 7, and a pneumatic regulating valve 8 34 is provided on the discharge pipeline at the bottom of the reaction liquid receiving tank 7; The data transmission and control of the pneumatic regulating valve, pneumatic shut-off valve, temperature transmitter, pressure transmitter and liquid level transmitter are all connected to the automatic control system in the computer, and the automatic control system adopts the distributed control system (DCS) control technology.

[0024] The Hofmann degradation reaction production method for continuous production of cyclopropylamine using the above system device comprises: 4480 Kg / h (cyclopropylcarboxamide molar flow rate 8.1 Kmol / h) of cyclopropylcarboxamide aqueous solution (containing sodium chloride) produced in the amination reaction section is pumped into a heat exchanger 1 and heated to 40°C, and the heated material enters a high-efficiency mixer 3; 4800 Kg / h of sodium hypochlorite / sodium hydroxide mixed solution (sodium hypochlorite / sodium hydroxide molar flow rates are 8.34 Kmol / h and 9 Kmol / h, respectively) is pumped into a heat exchanger 2 and heated to 40°C, and the heated material enters a high-efficiency mixer 3; the mixed material mixed by the high-efficiency mixer 3 enters a substitution reactor 4, the temperature of the substitution reactor 4 is controlled to be 60°C, the material stays in the substitution reactor 4 for 5 minutes, and the material after the substitution reaction enters a high-efficiency mixer 25 and 1200 Kg / h. Kg / h sodium hydroxide solution (sodium hydroxide molar flow rate is 9Kmol / h), the mixed material after mixing through the high-efficiency mixer 5 enters the Hofmann degradation reactor 6, the temperature of the Hofmann degradation reactor 6 is controlled to be 90°C, the material residence time in the Hofmann degradation reactor 6 is 8min, and the mixed material enters the reaction liquid receiving tank for temporary storage after the reaction in the Hofmann degradation reactor 6, and then enters the continuous distillation system to obtain the cyclopropylamine product, the cyclopropylamine yield is 95.80%, and the purity is 99.92%.

[0025] Example 2: This example is the same as Example 1 in other contents, except that the reaction temperature of the replacement reactor 4 is 45°C, the reaction temperature of the Hofmann degradation reactor 6 is 95°C, the yield of cyclopropylamine product is 95.34%, and the purity is 99.90%.

[0026] Example 3: This example is the same as Example 1 in other contents, except that the reaction temperature of the replacement reactor 4 is 80°C, the reaction temperature of the Hofmann degradation reactor 6 is 95°C, the yield of cyclopropylamine product is 94.27%, and the purity is 99.95%.

[0027] Example 4: This example is the same as Example 1 in other contents, except that the residence time of the mixture in the substitution reactor 4 is 3 min, the residence time of the mixture in the Hofmann degradation reactor 6 is 4 min, and the yield of cyclopropylamine product is 92.95% and the purity is 99.85%.

[0028] Example 5: This example is the same as Example 1 in other contents, except that the residence time of the mixture in the substitution reactor 4 is 3 min, the residence time of the mixture in the Hofmann degradation reactor 6 is 10 min, and the yield of cyclopropylamine product is 95.35% and the purity is 99.91%.

[0029] Example 6: This example is the same as Example 1 except that the sodium hypochlorite / sodium hydroxide mixture is 4780 Kg / h (the molar flow rates of sodium hypochlorite / sodium hydroxide are 8.15 Kmol / h and 9 Kmol / h, respectively), the yield of cyclopropylamine product is 93.72%, and the purity is 99.53%.

[0030] Example 7: This example is the same as Example 1 in other contents, except that: 4480 Kg / h (cyclopropylcarboxamide molar flow rate 8.1 Kmol / h) of cyclopropylcarboxamide aqueous solution (containing sodium chloride) produced in the amination reaction section is pumped into a heat exchanger 1 and heated to 60°C, and the heated material enters a high-efficiency mixer 3; 4800 Kg / h of sodium hypochlorite / sodium hydroxide mixed solution (sodium hypochlorite / sodium hydroxide molar flow rates are 8.34 Kmol / h and 9 Kmol / h, respectively) is pumped into a heat exchanger 2 and heated to 60°C, and the heated material enters a high-efficiency mixer 3. The yield of cyclopropylamine product is 95.72% and the purity is 99.83%.

Claims

1. A Hofmann degradation reaction system for continuous production of cyclopropylamine, characterized in that: The system comprises: a reaction module, a feeding module and an automatic control module; The reaction module comprises a substitution reactor, a high-efficiency mixer 1, a Hofmann degradation reactor, a high-efficiency mixer 2, and a reaction liquid receiving tank; the outlet of the high-efficiency mixer 1 is connected to the bottom of the substitution reactor through a pipeline, the upper part of the substitution reactor is connected to the high-efficiency mixer 2 through a pipeline, the high-efficiency mixer 2 is connected to the bottom of the Hofmann degradation reactor through a pipeline, the upper part of the Hofmann degradation reactor is connected to the reaction liquid receiving tank through a pipeline, and the bottom of the reaction liquid receiving tank is connected to a continuous distillation system through a pipeline; the substitution reactor and the Hofmann degradation reactor are both tubular reactors with a shell side and a tube side, the shell side of the reactor is a heat medium, and the tube side of the reactor is a material reaction medium; the top of the reaction liquid receiving tank is provided with safety accessories and an exhaust gas discharge port; The feeding module comprises pump 1, pump 2, pump 3, heat exchanger 1 and heat exchanger 2, wherein the sodium hydroxide solution is transported to the high-efficiency mixer 2 by pump 1, the sodium hydroxide / sodium hypochlorite mixed solution is transported to the heat exchanger 2 by pump 2, the outlet of the heat exchanger 2 is connected to the high-efficiency mixer 1 by a pipeline, the cyclopropylcarboxamide aqueous solution is transported to the heat exchanger 1 by pump 3, and the outlet of the heat exchanger 1 is connected to the high-efficiency mixer 1 by a pipeline; The automatic control module includes a pneumatic regulating valve on the outlet pipeline of pump 1 and a mass flow meter for automatically regulating the feeding amount of sodium hydroxide solution, a pneumatic regulating valve on the outlet pipeline of pump 2 and a mass flow meter for automatically regulating the feeding amount of sodium hydroxide / sodium hypochlorite mixed solution, and a pneumatic regulating valve on the outlet pipeline of pump 3 and a mass flow meter for automatically regulating the feeding amount of cyclopropylcarboxamide aqueous solution; pneumatic regulating valves are arranged on the heat medium inlet pipelines of heat exchanger 1 and heat exchanger 2, and pneumatic regulating valves are arranged on the heat medium outlet pipelines of heat exchanger 1 and heat exchanger 2. A pneumatic shut-off valve is provided, a temperature transmitter is provided inside the heat exchanger 1, and a temperature transmitter is provided on the material outlet pipeline of the heat exchanger 2; a pneumatic regulating valve is provided on the heat medium inlet pipelines of the replacement reactor and the Hoffman degradation reactor, a pneumatic shut-off valve is provided on the heat medium outlet pipelines of the replacement reactor and the Hoffman degradation reactor, and a temperature transmitter is provided on the material outlet pipelines of the replacement reactor and the Hoffman degradation reactor; a liquid level transmitter and a pressure transmitter are provided on the reaction liquid receiving tank, and a pneumatic regulating valve is provided on the discharge pipeline at the bottom of the reaction liquid receiving tank; The data transmission and control of the pneumatic regulating valve, pneumatic shut-off valve, temperature transmitter, pressure transmitter and liquid level transmitter are all connected to the automatic control system in the computer, and the automatic control system adopts the distributed control system control technology.

2. A Hofmann degradation reaction system for continuous production of cyclopropylamine according to claim 1, characterized in that: The first heat exchanger is a kettle structure, equipped with an anchor stirring, and the stirring speed is 60~200rad / min.

3. A Hofmann degradation reaction system for continuous production of cyclopropylamine according to claim 1, characterized in that: The safety accessories consist of a bursting disc and a safety valve. The bursting disc is located at the top of the reaction liquid receiving tank and is connected through a pipeline. The bursting disc is then connected to the safety valve through a pipeline. The discharge outlet of the safety valve is connected to the safety discharge buffer tank through a pipeline. A back pressure valve is provided on the exhaust gas discharge pipeline at the top of the reaction liquid receiving tank, and the end of the exhaust gas discharge pipeline away from the reaction liquid receiving tank is connected to the exhaust gas treatment system.

4. A Hofmann degradation reaction system for continuous production of cyclopropylamine according to claim 1, characterized in that: The heat medium is steam, hot water or thermal oil.

5. A method for producing cyclopropylamine using the Hofmann degradation reaction system for continuous production of cyclopropylamine according to any one of claims 1 to 4, characterized in that: After heat exchange in heat exchanger 1, the temperature of the cyclopropylcarboxamide aqueous solution is 40-60°C, and after heat exchange in heat exchanger 2, the temperature of the sodium hydroxide / sodium hypochlorite mixed solution is 40-60°C.

6. A method for producing cyclopropylamine using the Hofmann degradation reaction system for continuous production of cyclopropylamine according to any one of claims 1 to 4, characterized in that: The molar ratio of cyclopropylcarboxamide to sodium hypochlorite feed is 1:(1-1.1), the molar ratio of sodium hypochlorite to sodium hydroxide in the sodium hydroxide / sodium hypochlorite mixed solution is 1:(1-2), and the molar ratio of sodium hydroxide molar amount to cyclopropylcarboxamide in the sodium hydroxide solution is (1-2):

1.

7. A method for producing cyclopropylamine using the Hofmann degradation reaction system for continuous production of cyclopropylamine according to any one of claims 1 to 4, characterized in that: The temperature of the substitution reactor is 40-80°C, and the residence time of the mixed material in the substitution reactor is 2-8 minutes; the temperature of the Hofmann degradation reactor is 80-100°C, and the residence time of the mixed material in the Hofmann degradation reactor is 4-10 minutes.

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