A kind of production system and method of cycloheximide

Abstract

A cyclohexyl imine production system comprises a reactor, a filter, a dealcoholization tower, a decanter, and a separation tower, wherein a feed port is provided at the bottom of the reactor for connecting with adiponitrile, ethanol, alkali, and a hydrogen source, a discharge port is provided at the top of the reactor, and the dealcoholization tower is fed through the filter, the bottom liquid outlet of the dealcoholization tower is connected to the decanter, and the light phase outlet of the decanter is connected to the feed port of the separation tower. The present invention has a simple structure and is easy to operate, and can continuously and stably produce cyclohexyl imine and hexamethylenediamine at the same time, meeting the actual needs of chemical enterprises.

Description

Technical Field

[0001] The invention relates to the field of chemical industry, and in particular to a production system and method of cycloheximide. Background Art

[0002] Cyclohexylamine, also known as hexamethyleneimine (HMI), cyclohexamethyleneimine or azacycloheptane. As an organic chemical raw material, it is mainly used as a raw material for pesticides, pharmaceuticals and rubber products, and can also be used as an intermediate for pharmaceuticals and pesticides. In medicine, it is used to make penicillin, etc. In pesticides, it is used to synthesize herbicides and fungicides; it is also used in rubber vulcanizers, photographic agents, rust inhibitors, resin additives, etc.

[0003] Its synthesis routes include: using 1,6-hexanediamine to obtain by deamination and cyclization; using aniline as raw material and obtaining by catalytic hydrogenation; and using caprolactam as raw material. Its downstream products include 4-(1-azacycloheptanesulfonyl)aniline, 1-(4-chloro-1,2,5-thiadiazol-3-yl)azepane, hexamethyleniminoacetonitrile, hexahydro-1H-azepine-1-carboxaldehyde, N-dimethoxymethylazepane, 2-phenylazepane and other substances.

[0004] Because the synthetic route of 1,6-hexanediamine through deamination and cyclization is similar to the synthetic conditions of 1,6-hexanediamine, how to obtain cyclohexylimide product while producing hexanediamine is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] One of the purposes of the present invention is to provide a production system of cycloheximide in view of the deficiencies in the prior art, which has a simple structure and is easy to operate, and can continuously and stably produce cycloheximide and hexamethylenediamine at the same time, thereby meeting the actual needs of chemical companies.

[0006] The second object of the present invention is to provide a method for synthesizing cycloheximide using the above production system, which can continuously and stably produce cycloheximide and hexamethylenediamine products at the same time, and the purity of the cycloheximide product produced reaches more than 90wt%, the water content is below 9.5wt%, and the content of other organic impurities is below 0.5wt%, thereby ensuring product quality.

[0007] The technical solution for achieving one of the purposes of the present invention is: a production system of cyclohexylimide, comprising a reactor, a filter, a dealcoholization tower, a decanter, and a separation tower, wherein a feed port is arranged at the bottom of the reactor for being connected to adiponitrile, ethanol, alkali, and a hydrogen source, a discharge port is arranged at the top of the reactor, and the dealcoholization tower is fed through the filter, a bottom liquid outlet of the dealcoholization tower is connected to the decanter, and a light phase outlet of the decanter is connected to a feed port of the separation tower.

[0008] Furthermore, a first buffer tank is arranged between the reactor and the filter, and an agitator and a cooling mechanism are arranged in the first buffer tank.

[0009] Preferably, a filter feed pump is provided between the filter and the first buffer tank, the filter medium pore size of the filter is 1-20 μm, the material inlet of the filter is located below the filter medium, and the material outlet of the filter is located above the filter medium.

[0010] Furthermore, a heat exchanger is provided between the filter and the dealcoholization tower, the filter is connected to the feed port of the dealcoholization tower via the cold medium channel of the heat exchanger, and the bottom discharge port of the dealcoholization tower is connected to the feed port of the decanter via the hot medium channel of the heat exchanger.

[0011] Furthermore, a second buffer tank is arranged between the separation tower and the decanter, and a separation tower feed pump is arranged between the second buffer tank and the separation tower.

[0012] The technical solution for achieving the second object of the present invention is: a method for synthesizing cycloheximide using any of the above-mentioned production systems, comprising the following steps:

[0013] 1) adiponitrile, ethanol, alkali solution and catalyst are mixed to obtain a premixed solution, and the premixed solution is fed with excess hydrogen from a feed port of a reactor, and the reaction temperature is controlled to be 65-80° C. to obtain a reaction mixture, wherein the weight ratio of adiponitrile, ethanol, alkali solution and catalyst is 80-120:50-90:0.5-1.5:1-10, the concentration of the alkali solution is 30-45wt%, and the catalyst is a metal catalyst;

[0014] 2) The reaction mixture is subjected to gas-liquid separation, and the obtained liquid phase is cooled to 55-70°C, filtered to remove the catalyst, and then enters a dealcoholization tower to remove ethanol therein;

[0015] 3) The bottom liquid of the dealcoholization tower is cooled to 75-95°C and enters the decanter. The light phase overflowing from the decanter is sent to the separation tower, and the density of the light phase is <1.05g / cm 3 ;

[0016] 4) The top pressure of the separation tower is controlled to be -(80-100) KPaG, the bottom temperature is controlled to be 125-145° C., water is produced at the top of the separation tower, a hexamethylenediamine mixed liquid is produced at the bottom of the separation tower, and cycloheximide is produced intermittently in the middle section of the separation tower.

[0017] Preferably, the metal catalyst in step 1) is a nickel-based metal catalyst, and its activity is ≥5 ml H2 / g·min.

[0018] Preferably, the alkali solution in step 1) is a sodium hydroxide solution, and the molar ratio of the amount of hydrogen added to the amount of adiponitrile added is 2.2-4:1.

[0019] Preferably, the liquid phase obtained in step 2) is pressurized to 200-400 KPaG and then filtered, and the bottom temperature of the dealcoholization tower is 110-135°C.

[0020] Furthermore, in step 4), the hexamethylenediamine mixed liquid extracted from the bottom of the tower is separated to obtain a hexamethylenediamine product, and the content of cycloheximide intermittently extracted from the middle section of the separation tower reaches more than 90wt%, the content of impurity organic matter is less than 0.5wt%, and the remainder is water.

[0021] The above technical solution has the following beneficial effects:

[0022] 1. The production system of cyclohexylimide of the present invention comprises a reactor, a filter, a dealcoholization tower, a decanter, and a separation tower, wherein the reactor is used to provide space and reaction conditions for synthesizing a target product from raw materials, the filter is used to remove the catalyst contained in the reaction product, to avoid the reaction product from continuing to catalyze the reaction under the action of the catalyst, to avoid the generation of by-products, and to ensure the yield of cyclohexylimide, the dealcoholization tower is used to separate and recover ethanol in the reaction product, the decanter is used to separate and recover alkali in the reaction product, and the separation tower is used to separate water, cyclohexylimide product and hexamethylenediamine product in the reaction product, which is beneficial to subsequent further purification, and the content of the separated cyclohexylimide product reaches more than 90wt%, the water content is controlled to be below 9.5wt%, and the content of impurity organic matter is less than 0.5wt%, and no sodium hydroxide is contained.

[0023] 2. A first buffer tank is provided between the reactor and the filter of the production system of the present invention. The first buffer tank is provided with an agitator and a cooling mechanism. Before filtering the reaction product, the reaction product is cooled in time and the reaction product is kept uniform, thereby further reducing the risk of the reaction product continuing to react to produce by-products and ensuring the yield of cycloheximide.

[0024] 3. A filter feed pump is arranged between the filter and the first buffer tank of the production system of the present invention. The filter medium pore size of the filter is 1-20 μm, and the material inlet of the filter is located below the filter medium, and the material outlet of the filter is located above the filter medium, so that the reaction product is pressurized and filtered through the filter medium with a pore size of 1-20 μm, forming a self-filtration layer on the surface of the filter medium with a certain thickness, thereby ensuring that the catalyst entrained in the material is completely removed.

[0025] 4. A heat exchanger is provided between the filter and the dealcoholization tower in the production system of the present invention. The filter is connected to the feed port of the dealcoholization tower via the cold medium channel of the heat exchanger, and the bottom discharge port of the dealcoholization tower is connected to the feed port of the decanter via the hot medium channel of the heat exchanger. That is, the low-temperature catalyst-removed reaction product material exchanges heat with the high-temperature dealcoholization reaction product material before entering the tower, thereby reducing the heat required for heating the dealcoholization tower feed and the heat required for cooling the discharge. At the same time, it is also beneficial for the alkali solution in the dealcoholization reaction product material to precipitate in the decanter, thereby improving the alkali separation effect.

[0026] 5. The synthesis method of the present invention controls the weight ratio of adiponitrile, ethanol, alkali solution and catalyst to 80-120:50-90:0.5-1.5:1-10, and controls the reaction temperature to 65-80°C, and performs a hydrogenation reaction under the action of a catalyst to generate a mixed solution including cyclohexylimide, 1,2-cyclohexyldiamine, hexamethylenediamine, 2-hexamethylenetriamine, etc., which can effectively control the reaction hydrogenation rate, the generation of organic impurities such as 6-aminocapronitrile and 2-aminocyclopentylmethylamine, and achieve the purpose of industrially synthesizing cyclohexylimide and hexamethylenediamine at the same time. If the reaction conditions are changed, the material reaction will be incomplete, the conversion rate will be low, or the material and the catalyst will over-react to generate heavy component by-products.

[0027] The applicant has verified through experiments that the conversion rate of adiponitrile can reach above 99.9% and the selectivity of cycloheximide and hexamethylenediamine is ≥97% by using the synthesis method of the present invention.

[0028] Further description is given below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a connection schematic diagram of the production system of the present invention.

[0030] In the accompanying drawings, 1 is a reactor, 2 is a filter, 3 is a dealcoholization tower, 4 is a decanter, 5 is a separation tower, 6 is a first buffer tank, 7 is a filter feed pump, 8 is a heat exchanger, 9 is a second buffer tank, and 10 is a separation tower feed pump. DETAILED DESCRIPTION

[0031] In the present invention, the equipment or parts without specific structure are usually conventional equipment or parts in the chemical industry, and the specific connection method is usually conventional connection method in the chemical industry or connection method recommended by the manufacturer. The raw materials used meet the requirements of relevant national or industry standards.

[0032] Example 1

[0033] The production system of cyclohexyl imine comprises a reactor 1, a filter 2, a dealcoholization tower 3, a decanter 4, and a separation tower 5. The reactor 1 adopts a gas, liquid, and solid three-phase fluidized bed reactor, and a material circulation pipeline using hydrogen as a power is arranged in the structure, which is conducive to fully mixing various materials, stabilizing the reaction, making it easy to control, and reducing by-products. A feed port is arranged at the bottom of the reactor, which is used to connect with adiponitrile, ethanol, alkali, and hydrogen sources. A discharge port is arranged at the top of the reactor 1, and the dealcoholization tower 3 is fed through the filter 2. Specifically, a first buffer tank 6 is arranged between the reactor 1 and the filter 2, and a stirrer and a cooling mechanism are arranged in the first buffer tank 6. The cooling mechanism can adopt, for example, a cooling coil or a cooling jacket. A filter feed pump 7 is arranged between the filter 2 and the first buffer tank 6. The filter medium pore size of the filter 2 is 1-20 μm, and the material inlet of the filter is located below the filter medium, and the material outlet of the filter is located above the filter medium. The bottom liquid outlet of the dealcoholization tower 3 is connected to the decanter 4. In this embodiment, a heat exchanger 8 is provided between the filter 2 and the dealcoholization tower 3. The material outlet of the filter 2 is connected to the feed port of the dealcoholization tower 3 through the cold medium channel of the heat exchanger. The bottom discharge port of the dealcoholization tower is connected to the feed port of the decanter through the hot medium channel of the heat exchanger. A top cooler is provided at the top of the dealcoholization tower, and a bottom reboiler is provided at the bottom of the dealcoholization tower. The light phase outlet of the decanter 4 is connected to the feed port of the separation tower 5. Specifically, a second buffer tank 9 is provided between the separation tower 5 and the decanter 4, and a separation tower feed pump 10 is provided between the second buffer tank 9 and the separation tower 5. A top condenser is provided at the top of the separation tower, and a bottom reboiler is provided at the bottom of the separation tower.

[0034] Example 2

[0035] The method for synthesizing cycloheximide using the production system of Example 1 comprises the following steps:

[0036] 1) adiponitrile, ethanol, sodium hydroxide solution and catalyst are mixed to obtain a premixed liquid, which is fed with hydrogen from the feed port of the reactor. The weight ratio of adiponitrile, ethanol, sodium hydroxide solution and catalyst is 100:70:0.8:3, the concentration of sodium hydroxide solution is 30wt%, the catalyst is a nickel-based metal catalyst, the flow rate of the premixed liquid is 4.35t / h, and the flow rate of hydrogen is 5200Nm 3 / h. The reaction temperature was controlled to be 70°C, and a hydrogenation reaction was performed to obtain a reaction mixture;

[0037] 2) The reaction mixture is subjected to gas-liquid separation, hydrogen is removed therefrom, and the obtained liquid phase enters the first buffer tank, is cooled to 60°C, and is pressurized to 280KPaG by a filter feed pump. After the catalyst is removed by a filter (the filter medium of the filter is a high-precision filter cloth with a pore size of 2μm), it is preheated in a heat exchanger and then enters a dealcoholization tower, the tower bottom temperature is controlled at 115°C, and ethanol is removed therefrom;

[0038] 3) After cooling down in the heat exchanger, the bottom liquid of the dealcoholization tower enters the decanter at a temperature of 80°C. Sodium hydroxide is separated from the bottom of the decanter and recycled. The light phase overflows from the top of the decanter and is sent to the second buffer tank. The density of the light phase is <1.05g / cm 3 ;

[0039] 4) The light phase in the second buffer tank is sent to a separation tower, which is a distillation tower. The top pressure of the separation tower is controlled to be -95 KPaG, and the bottom temperature is 130° C. Water is produced at the top of the separation tower, and a hexamethylenediamine mixed liquid is produced at the bottom of the separation tower. The middle section of the separation tower is opened for 600 seconds to produce a target product of cycloheximide.

[0040] It has been verified that 90% of cyclohexylimine produced by the separation tower is about 14.9 kg / h, and the hexamethylenediamine content in the produced hexamethylenediamine mixture is about 2.60 t / h. The selectivity of cyclohexylimine and hexamethylenediamine is 97.33%.

[0041] Example 3

[0042] The method for synthesizing cycloheximide using the production system of Example 1 comprises the following steps:

[0043] 1) adiponitrile, ethanol, sodium hydroxide solution and catalyst are mixed to obtain a premixed liquid, which is fed with hydrogen from the feed port of the reactor. The weight ratio of adiponitrile, ethanol, sodium hydroxide solution and catalyst is 100:75:1.2:5, the concentration of sodium hydroxide solution is 32wt%, the catalyst is a nickel-based metal catalyst, the flow rate of the premixed liquid is 10.0t / h, and the flow rate of hydrogen is 13700Nm 3 / h. The reaction temperature was controlled to be 75°C, and a hydrogenation reaction was performed to obtain a reaction mixture;

[0044] 2) The reaction mixture is subjected to gas-liquid separation to remove hydrogen therein, and the obtained liquid phase enters the first buffer tank, is cooled to 58°C, and is pressurized to 320KPaG by a filter feed pump. After the catalyst is removed by a filter (the filter medium of the filter is a high-precision filter cloth with a pore size of 2μm), it is preheated in a heat exchanger and enters a dealcoholization tower. The tower bottom temperature is controlled at 120°C to remove ethanol therein;

[0045] 3) After cooling down in the heat exchanger, the bottom liquid of the dealcoholization tower enters the decanter at a temperature of 82°C. Sodium hydroxide is separated from the bottom of the decanter and recycled. The light phase overflows from the top of the decanter and is sent to the second buffer tank. The density of the light phase is <1.05g / cm 3 ;

[0046] 4) The light phase in the second buffer tank is sent to a separation tower, which is a distillation tower. The top pressure of the separation tower is controlled to be -93 KPaG, and the bottom temperature is 135° C. Water is produced at the top of the separation tower, and a hexamethylenediamine mixed liquid is produced at the bottom of the separation tower. The middle section of the separation tower is opened for 350 seconds to produce a target product of cycloheximide.

[0047] It has been verified that 90% of cyclohexylimine produced by the separation tower is about 29.6 kg / h, and the hexamethylenediamine content in the produced hexamethylenediamine mixture is about 5.75 t / h. The selectivity of cyclohexylimine and hexamethylenediamine is 97.43%.

Claims

1. A synthetic method for cycloheximide, characterized in that: The production system used includes a reactor (1), a filter (2), a dealcoholization tower (3), a decanter (4), and a separation tower (5). The bottom of the reactor (1) is provided with a feed port for connecting to adiponitrile, ethanol, alkali, and a hydrogen source. The top of the reactor (1) is provided with a discharge port for supplying materials to the dealcoholization tower (3) through a filter (2). The bottom liquid outlet of the dealcoholization tower (3) is connected to the decanter (4), and the light phase outlet of the decanter (4) is connected to the feed inlet of the separation tower (5). The following steps are involved: 1) adiponitrile, ethanol, alkali solution and catalyst are mixed to obtain a premixed solution, which is fed with excess hydrogen from a feed port of a reactor, and the reaction temperature is controlled to be 65-80° C. to obtain a reaction mixture, wherein the weight ratio of adiponitrile, ethanol, alkali solution and catalyst is 80-120:50-90:0.5-1.5:1-10, the concentration of alkali solution is 30-45wt%, and the catalyst is a metal catalyst; 2) The reaction mixture is separated into gas and liquid, and the obtained liquid phase is cooled to 55-70°C, filtered to remove the catalyst, and then enters the dealcoholization tower to remove the ethanol therein; 3) The bottom liquid of the dealcoholization tower is cooled to 75-95℃ and enters the decanter. The light phase overflowing from the decanter is sent to the separation tower, and the density of the light phase is <1.05g / cm 3 ; 4) The top pressure of the separation tower is controlled to be -(80-100) KPaG, the bottom temperature is controlled to be 125-145°C, water is produced at the top of the separation tower, a hexamethylenediamine mixed liquid is produced at the bottom of the separation tower, and cycloheximide is produced intermittently in the middle section of the separation tower.

2. The synthetic method of cycloheximide according to claim 1, characterized in that: A first buffer tank (6) is arranged between the reactor (1) and the filter (2), and a stirrer and a cooling mechanism are arranged in the first buffer tank (6).

3. The synthetic method of cycloheximide according to claim 2, characterized in that: A filter feed pump (7) is provided between the filter (2) and the first buffer tank (6); the filter medium of the filter (2) has a pore size of 1-20 μm, and the material inlet of the filter is located below the filter medium, and the material outlet of the filter is located above the filter medium.

4. The synthetic method of cycloheximide according to claim 1, characterized in that: A heat exchanger (8) is provided between the filter (2) and the dealcoholization tower (3); the filter (2) is connected to the feed port of the dealcoholization tower (3) via a cold medium channel of the heat exchanger; and the bottom discharge port of the dealcoholization tower is connected to the feed port of the decanter via a hot medium channel of the heat exchanger.

5. The synthetic method of cycloheximide according to claim 1, characterized in that: A second buffer tank (9) is arranged between the separation tower (5) and the decanter (4), and a separation tower feed pump (10) is arranged between the second buffer tank (9) and the separation tower (5).

6. The synthetic method of cycloheximide according to claim 1, characterized in that Step 1) The metal catalyst is a nickel-based metal catalyst, and its activity is ≥5ml H2 / g·min.

7. The synthetic method of cycloheximide according to claim 1, characterized in that, Step 1) The alkali solution is a sodium hydroxide solution, and the molar ratio of the amount of hydrogen added to the amount of adiponitrile added is 2.2-4:

1.

8. The synthetic method of cycloheximide according to claim 1, characterized in that, Step 2) The liquid phase obtained is pressurized to 200-400 KPaG and then filtered. The bottom temperature of the dealcoholization tower is 110-135°C.

9. The synthetic method of cycloheximide according to claim 1, characterized in that, Step 4) The hexamethylenediamine mixed liquid taken out from the bottom of the tower is separated to obtain the hexamethylenediamine product, the content of cycloheximide taken out intermittently in the middle section of the separation tower reaches more than 90wt%, the content of impurity organic matter is less than 0.5wt%, and the remainder is water.

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