Ketal synthesis reaction device and production method

Abstract

The invention discloses a ketal synthesis reaction device and a production method. The device comprises a reaction unit, a liquid phase separation unit and a gas phase treatment unit; the reaction unit comprises a reactor with a cavity, a bubbling device is arranged inside the cavity of the reactor; the reactor is also provided with a heating component; the liquid phase separation unit comprises a separator; the gas phase treatment unit comprises a stripping tower, a condenser, a reflux device and a decanter. The device adopts a "reaction-distillation-decantation-separation" combined operation, and nitrogen is introduced to fully stir the materials, so as to improve the overall reaction yield of ketone-alcohol condensation, and reduce the equipment specifications through continuous production. The method can be used for the continuous production of ketal compounds, thereby reducing the equipment specifications, reducing the loss of raw materials, and improving the product yield.

Description

Technical Field

[0001] The present application relates to a ketal synthesis reaction device and a production method, belonging to the field of reaction technology. Background Art

[0002] Ketals are a type of fine chemical products with a special floral and fruity aroma, and are therefore widely used in the fragrance and flavoring of cosmetics, alcoholic beverages, food, and other daily necessities, as well as in the synthesis of spices. At the same time, ketal compounds are also often used as carbonyl protecting agents and drug intermediates due to their synthetic reversibility.

[0003] The existing ketal production process uses ketone alcohol as raw material to undergo dehydration condensation reaction, and adopts azeotropic evaporation method to evaporate water and water-carrying agent together to improve the raw material conversion rate. The whole process adopts intermittent operation, the equipment specifications are large, the energy consumption is high, and a lot of raw material alcohol is carried away in the wastewater, resulting in a waste of raw materials, reducing the overall yield of the product and limiting the scale of production. At the same time, the traditional reactor uses a large electric stirrer to stir the raw materials, and the equipment is too large. Therefore, it is necessary to improve the ketone alcohol condensation reaction process, develop a continuous production method, improve the product yield, and reduce the equipment scale and investment. Summary of the invention

[0004] The present application provides a ketone-alcohol synthesis continuous reaction device, which can be operated continuously and improve the product yield. Nitrogen is used to replace the traditional large-scale plug-in electric stirrer, making it possible to use internal coils for heat transfer in the reactor, thereby increasing the effective space of the reactor and the heat transfer efficiency.

[0005] The device comprises a reaction unit, a liquid phase separation unit, and a gas phase treatment unit;

[0006] The reaction unit comprises a reactor having a cavity, wherein a bubbling device is provided inside the cavity of the reactor; the reactor is also provided with a heating component;

[0007] The liquid phase separation unit comprises a separator;

[0008] The gas phase treatment unit includes a stripping tower, a condenser, a reflux device, and a decanter;

[0009] The reaction unit is connected to the liquid phase separation unit and the gas phase treatment unit respectively;

[0010] The gas phase outlet of the reactor is connected to the gas phase inlet of the stripping tower through a pipeline and a flange, and the gas phase outlet of the stripping tower is connected to the inlet of the reflux device through a condenser; the liquid phase outlet of the reflux device is connected to the liquid phase inlet of the stripping tower and the liquid phase inlet of the decanter through pipeline I and pipeline II, respectively, and the gas phase outlet of the reflux device is connected to the gas phase inlet of the reactor; the oil phase outlet of the decanter is connected to the oil phase inlet of the reactor.

[0011] Optionally, the decanter further includes a water phase outlet; the liquid phase outlet of the reflux device is connected to pipeline I and pipeline II respectively through pump I.

[0012] The gas phase outlet of the reflux device is connected to the gas phase inlet of the reactor through a pressurizing device.

[0013] Optionally, the liquid phase outlet of the reactor is connected to the liquid phase inlet of the separator, and the outlet I of the separator is connected to the inlet I of the reactor;

[0014] Preferably, the outlet I of the separator is connected to the inlet I of the reactor via a pump II; the separator also includes a product outlet.

[0015] Optionally, the stripping tower is a plate tower, and the theoretical number of plates of the plate tower is 8 to 25; the number of plates theoretically affects the separation effect of by-product water. If the theoretical number of plates is too low, the water component cannot be separated to the greatest extent, and if the theoretical number of plates is too high, the equipment investment will be affected.

[0016] Optionally, the heating component is selected from at least one of a jacket and an inner / outer coil;

[0017] The reactor also includes a feedstock inlet.

[0018] One solution of the device described in the present application includes a reaction unit, a liquid phase separation unit, and a gas phase treatment unit;

[0019] The reaction unit comprises a reactor having a cavity, wherein a bubbling device is provided inside the cavity of the reactor; the reactor is also provided with a heating component; the heating component is selected from at least one of a jacket and an inner / outer coil;

[0020] The liquid phase separation unit comprises a separator;

[0021] The gas phase treatment unit comprises a stripping tower, a condenser, a reflux device, and a decanter. The stripping tower is a plate tower, and the number of theoretical plates of the plate tower is 8 to 25.

[0022] The reaction unit is connected to the liquid phase separation unit and the gas phase treatment unit respectively;

[0023] The gas phase outlet of the reactor is connected to the gas phase inlet of the stripping tower through a pipeline and a flange, and the gas phase outlet of the stripping tower is connected to the inlet of the reflux device through a condenser; the liquid phase outlet of the reflux device is connected to the liquid phase inlet of the stripping tower and the liquid phase inlet of the decanter through pipeline I and pipeline II, respectively, and the gas phase outlet of the reflux device is connected to the gas phase inlet of the reactor; the oil phase outlet of the decanter is connected to the oil phase inlet of the reactor; the decanter also includes a water phase outlet; the liquid phase outlet of the reflux device is connected to pipeline I and pipeline II respectively through pump I;

[0024] The gas phase outlet of the reflux device is connected to the gas phase inlet of the reactor through a pressurizing device.

[0025] The liquid phase outlet of the reactor is connected to the liquid phase inlet of the separator, and the outlet I of the separator is connected to the inlet I of the reactor; the outlet I of the separator is connected to the inlet I of the reactor through a pump II; and the separator also includes a product outlet.

[0026] According to another aspect of the present application, a method for continuous synthesis of ketal is provided, wherein raw materials containing ketone, alcohol and water-carrying agent are introduced into a reactor of the continuous reaction device for synthesis of ketal to react and synthesize ketal.

[0027] Optionally, the ketone is selected from at least one of cyclohexanone, cyclohexanedione, cyclopentanone and butanone;

[0028] The alcohol is a dihydroxy alcohol compound;

[0029] The dihydroxy alcohol compound is selected from at least one of ethylene glycol, propylene glycol, butylene glycol and hexylene glycol;

[0030] The water-carrying agent is a compound that can form an azeotropic system with water, and is selected from at least one of cyclohexane, benzene, dichloromethane, carbon tetrachloride, and petroleum ether.

[0031] Optionally, the reaction is carried out under an inert atmosphere;

[0032] The inert atmosphere is selected from at least one of nitrogen, carbon dioxide and an inert gas;

[0033] Optionally, the method specifically comprises the following steps:

[0034] (a) introducing raw materials into a reactor containing a catalyst from the raw material inlet of the reactor, and introducing an inert atmosphere from the gas inlet via the bubbling device; the raw materials are heated to a reaction temperature by the heating component in the reactor to generate gas phase products and liquid phase products;

[0035] (b) the gas phase product described in step (a) passes through the stripping tower and is exchanged with the liquid phase refluxed through the reflux device for mass transfer, and the gas phase containing water and water-carrying agent is separated from the acetal product; the gas phase containing water and water-carrying agent is condensed in the condenser and enters the reflux device for gas-liquid phase separation, the condensed gas phase returns to the reactor through the reflux device, and the condensed liquid phase returns to the stripping tower through pipeline I and pipeline II and is sent to a decanter; the liquid phase entering the decanter is separated into an oil phase and a water phase, the oil phase is returned to the reactor as a water-carrying agent, and the water phase is discharged as waste water;

[0036] The liquid phase product in step (a) enters the separator and is separated by gravity sedimentation to obtain slurry and reaction products. The separated slurry is returned to the reactor, and the reaction products are discharged from the product outlet of the separator.

[0037] Optionally, in step (a), the molar ratio of the inert atmosphere to the total amount of alcohol ketone is 0.01-1.

[0038] Preferably, the upper limit of the molar ratio of the inert atmosphere to the total amount of alcohol ketone can be independently selected from 0.6, 0.7, 0.8, 0.9, 1; the lower limit of the molar ratio of the inert atmosphere to the total amount of alcohol ketone can be independently selected from 0.011, 0.02, 0.03, 0.04, 0.05;

[0039] The reaction temperature is 80-150°C;

[0040] Preferably, the reaction temperature can be independently selected from 80°C, 90°C, 100°C, 105°C, 110°C, 120°C, 130°C, 140°C, 150°C;

[0041] Optionally, in step (b), the pressure of the stripping tower is 101.3 to 110 kPaA;

[0042] Preferably, the pressure of the stripping tower is 101.3-105 kPaA;

[0043] The temperature of the top of the stripping tower is 10-50°C;

[0044] Preferably, the temperature at the top of the stripping tower is 10 to 45°C;

[0045] The reflux ratio of the stripping tower is 0.1-30.

[0046] Preferably, the reflux ratio of the stripping tower is 1-15.

[0047] The oil phase includes a water carrier and a ketone.

[0048] Optionally, the slurry comprises a catalyst, an unseparated product mixture.

[0049] The beneficial effects of this application include:

[0050] 1) Continuous production and reduced equipment specifications;

[0051] 2) Stable operation to ensure product quality;

[0052] 3) The unreacted raw alcohol contained in the gas phase is recovered and stripped back to the reactor via a stripping tower, thereby reducing the loss in the separation process and improving the product yield.

[0053] 4) The present application adopts nitrogen bubbling stirring to save electricity consumption, and replaces the traditional large-scale plug-in electric stirrer with nitrogen, making it possible to use internal coil heat transfer in the reactor, thereby increasing the effective space of the reactor and the heat transfer efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 Schematic diagram of the ketal synthesis reaction device containing a bubbling device prepared in Example 1 of the present application.

[0055] 1. Reactor; 2. Stripping tower; 3. Condenser; 4. Reflux tank; 5. Circulation pump; 6. Decanter; 7. Separator; 8. Slurry pump; 9. Blower; 10. Coil; 11. Bubbling device. DETAILED DESCRIPTION

[0056] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0057] Unless otherwise specified, the raw materials and catalysts in the examples of this application were purchased through commercial channels.

[0058] Example 1

[0059] like Figure 1 As shown, the present invention provides a ketal synthesis reaction device, comprising a reactor 1, a stripping tower 2, a condenser 3, a reflux tank 4, a circulating pump 5, a decanter 6, a separator 7, a slurry pump 8, and a blower 9, wherein a bubbling device 11 and a coil 10 are arranged at the bottom of the reactor 1; the top gas phase outlet of the reactor 1 is connected to the bottom gas phase inlet of the stripping tower 2, the top gas phase outlet of the stripping tower 2 is connected to the inlet of the condenser 3, the outlet of the condenser 3 is connected to the inlet of the reflux tank 4, and the gas phase outlet of the reflux tank 4 is connected to the blower 9 The gas phase outlet of the blower 9 is connected to the gas phase inlet of the reactor 1, the liquid phase outlet of the reflux tank 4 is connected to the circulation pump 5, the outlet pipeline of the circulation pump 5 is divided into two branches and is respectively connected to the liquid phase inlet of the stripping tower 2 and the liquid phase inlet of the decanter 6, the oil phase outlet of the decanter 6 is connected to the oil phase inlet of the reactor 1, and the water phase is discharged from the water phase outlet as waste water, the liquid phase outlet at the bottom of the reactor 1 is connected to the liquid phase inlet of the separator 7, the slurry outlet of the separator 7 is connected to the raw material inlet of the reactor 1 through the slurry pump 8, and a product outlet is provided on the upper part of the separator 7.

[0060] Example 2

[0061] This embodiment also provides a method for continuous synthesis of ketal, using Figure 1 The device shown specifically comprises the following steps:

[0062] Cyclohexanone, ethylene glycol and cyclohexane with water are sent to the reactor 1 as reaction materials. A supported phosphomolybdic tungstic acid catalyst is filled in the reactor 1. Nitrogen enters the reactor 1 through a bubbling device. The molar ratio of nitrogen to the total amount of alcohol ketone raw materials is 0.02. The material is heated to 105°C by steam in the jacket, and a dehydration condensation reaction occurs to generate cyclohexanone ethylene glycol acetal and a large amount of water. The water, cyclohexane, a small amount of reaction raw materials and products, and a mixed gas of stirring nitrogen obtained after the reaction enter the stripping tower 2 through the connection point, and are exchanged with the reflux liquid flowing down from the top of the tower step by step. The reflux ratio of the stripping tower 2 is 20, the top pressure is 102kPaA, the number of theoretical plates is 25, and the top temperature is 10°C. Finally, the gas phase flowing out from the top of the stripping tower 2 is condensed by the condenser 3 to obtain a gas-liquid mixture at 10°C, and is sent to the reflux tank 4 to achieve gas-liquid separation. The gas phase is pressurized by the blower 9 and returns to the reactor 1 for use as circulating nitrogen. The liquid phase is pressurized by the circulation pump 5 and partially returned to the top of the stripping tower 2 as reflux, and partially sent to the decanter 6 for stable stratification. The oil phase in the decanter 6 is cyclohexane with a molar fraction greater than 99.1%, which is returned to the reactor for use as a dehydrating agent, and the water phase is wastewater with a molar fraction greater than 99.1%. The mixture at the bottom of the reactor 1 is sent to the separator 7 for separation, and the catalyst and part of the product mixture at the bottom are pressurized by the slurry pump 8 and returned to the reactor 1. The upper product is sent out of the reaction device and sent to other separation units outside the system.

[0063] The overall yield of the process product is 92%, which is higher than the single-pass yield of 90%, and can be used for the continuous production of cyclohexanone ethylene glycol acetal.

[0064] Example 3

[0065] This embodiment also provides a method for continuous synthesis of ketal, using Figure 1 The device shown specifically comprises the following steps:

[0066] Butanone, ethylene glycol and cyclohexane with water are sent to the reactor 1 as reaction materials. The reactor 1 is filled with a copper metal-loaded SBA-15 catalyst. Nitrogen enters the reactor 1 through a bubbling device. The molar ratio of nitrogen to the total amount of alcohol ketone raw materials is 0.011. It is heated to 110°C by steam in the jacket, and a dehydration condensation reaction occurs to generate butanone ethylene glycol acetal and a large amount of water. The water, cyclohexane, a small amount of reaction raw materials and products, and a mixed gas of stirring nitrogen obtained after the reaction enter the stripping tower 2 through the connection point, and are exchanged with the reflux liquid flowing down from the top of the tower step by step. The reflux ratio of the stripping tower 2 is 1.36, the top pressure is 102kPaA, the number of theoretical plates is 20, and the top temperature is 20°C. Finally, the gas phase flowing out from the top of the stripping tower 2 is condensed by the condenser 3 to obtain a gas-liquid mixture at 20°C, and is sent to the reflux tank 4 to achieve gas-liquid separation. The gas phase is pressurized by the blower 9 and returned to the reactor 1 for use as circulating nitrogen. The liquid phase is pressurized by the circulating pump 5 and partially returned to the top of the stripping tower 2 as reflux, and partially sent to the decanter 6 for stable stratification. The oil phase in the decanter 6 is composed of cyclohexane with a molar fraction of 84.8% and butanone with a molar fraction of 13.9%, which is returned to the reactor as a dehydrating agent and circulating raw material. The water phase is waste water with a molar fraction greater than 98.3%. The mixture at the bottom of the reactor 1 is sent to the separator 7 for separation, and the catalyst and part of the product mixture at the bottom are pressurized by the slurry pump 8 and returned to the reactor 1, and the upper product is sent out of the reaction device to the separation unit.

[0067] The overall yield of the process product is 96.5%, which is higher than the single-pass yield of 85%, and can be used for the continuous production of butanone glycol acetal.

[0068] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A ketal synthesis continuous reaction device, characterized in that: The device comprises a reaction unit, a liquid phase separation unit, and a gas phase treatment unit; The reaction unit comprises a reactor having a cavity, wherein a bubbling device is provided inside the cavity of the reactor; the reactor is also provided with a heating component; The liquid phase separation unit comprises a separator; The gas phase treatment unit includes a stripping tower, a condenser, a reflux device, and a decanter; The reaction unit is connected to the liquid phase separation unit and the gas phase treatment unit respectively; The gas phase outlet of the reactor is connected to the gas phase inlet of the stripping tower, and the gas phase outlet of the stripping tower is connected to the inlet of the reflux device through a condenser; the liquid phase outlet of the reflux device is connected to the liquid phase inlet of the stripping tower and the liquid phase inlet of the decanter through pipeline I and pipeline II, respectively, and the gas phase outlet of the reflux device is connected to the gas phase inlet of the reactor; the oil phase outlet of the decanter is connected to the oil phase inlet of the reactor; The stripping tower is a plate tower, and the number of theoretical plates of the plate tower is 8 to 25; The heating component is selected from at least one of a jacket and an inner / outer coil.

2. The device according to claim 1, characterized in that The decanter also includes a water phase outlet; the liquid phase outlet of the reflux device is connected to pipeline I and pipeline II respectively through pump I; The gas phase outlet of the reflux device is connected to the gas phase inlet of the reactor through a pressurizing device.

3. The device according to claim 1, characterized in that The liquid phase outlet of the reactor is connected to the liquid phase inlet of the separator, and the outlet I of the separator is connected to the inlet I of the reactor.

4. The device according to claim 1, characterized in that The outlet I of the separator is connected to the inlet I of the reactor via a pump II; the separator also includes a product outlet.

5. A method for continuous synthesis of ketal, characterized in that: Passing raw materials containing ketone, alcohol and water-carrying agent into the reaction device according to any one of claims 1 to 4 to react and synthesize ketal; The water-carrying agent is cyclohexane.

6. The method according to claim 5, characterized in that The ketone is selected from at least one of cyclohexanone, cyclohexanedione, cyclopentanone and butanone; The alcohol is a dihydroxy alcohol compound.

7. The method according to claim 6, characterized in that The dihydroxy alcohol compound is selected from at least one of ethylene glycol, propylene glycol, butylene glycol and hexylene glycol.

8. The method according to claim 5, characterized in that The reaction is carried out under an inert atmosphere; The inert atmosphere is selected from at least one of nitrogen, carbon dioxide and an inert gas.

9. The method according to claim 8, characterized in that The method specifically comprises the following steps: (a) introducing raw materials into a reactor containing a catalyst from the raw material inlet of the reactor, and introducing an inert atmosphere from the gas phase inlet through the bubbling device; the raw materials are heated to a reaction temperature by the heating component in the reactor to generate gas phase products and liquid phase products; (b) the gas phase product of step (a) passes through the stripping tower and is exchanged with the liquid phase refluxed through the reflux device for mass transfer, and the gas phase containing water and water-carrying agent is separated from the acetal product; the gas phase containing water and water-carrying agent is condensed in the condenser and enters the reflux device for gas-liquid phase separation, the condensed gas phase returns to the reactor through the reflux device, the condensed liquid phase returns to the stripping tower through pipeline I and pipeline II and is sent to the decanter; the liquid phase entering the decanter is separated into an oil phase and a water phase, the oil phase is returned to the reactor as a water-carrying agent, and the water phase is discharged as waste water; The liquid phase product in step (a) enters the separator and is separated by gravity sedimentation to obtain slurry and reaction products. The separated slurry is returned to the reactor, and the reaction products are discharged from the product outlet of the separator.

10. The method according to claim 9, characterized in that In step (a), the molar ratio of the inert atmosphere to the total amount of alcohol and ketone is 0.01 to 1; The reaction temperature is 80-150°C; In step (b), the pressure of the stripping tower is 101.3-110 kPaA; The temperature of the top of the stripping tower is 10-50°C; The reflux ratio of the stripping tower is 0.1-30.

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