A method and system for producing caprolactone

Abstract

The present invention provides a method and system for producing caprolactone, comprising the following steps: S1: continuously adding carboxylic acid, a catalyst, a stabilizer, and hydrogen peroxide to a supergravity reactor; vaporizing a water-carrying agent and continuously adding the same to the supergravity reactor; S2: reacting the carboxylic acid and hydrogen peroxide in the supergravity reactor to generate peroxycarboxylic acid, wherein a peroxycarboxylic acid reaction liquid containing the water-carrying agent, the catalyst, and the stabilizer enters a dehydration device for heating, dehydration, and separation; azeotropic mixtures of the vaporized water-carrying agent and water are discharged, condensed, and separated by stratification; the separated water-carrying agent is circulated back to the dehydration device and continuously removed with water; S3: continuously discharging the separated peroxycarboxylic acid reaction liquid from the dehydration device, wherein a portion is sent to a caprolactone reactor after water removal, and the other portion is circulated into the supergravity reactor for further reaction; and S4: simultaneously adding cyclohexanone to the caprolactone reactor to react to obtain a crude caprolactone product, which is then rectified and separated to obtain caprolactone.

Description

Technical Field

[0001] The present invention relates to the field of new materials, and in particular to a method and system for producing a caprolactone monomer. Background Art

[0002] ε-caprolactone, chemical formula is C6H 10 O2 is a colorless liquid with a density of 1.0693, a boiling point of 98-99°C (1.33 kPa), and a melting point of approximately -5°C. It is readily soluble in water, ethanol, and benzene. ε-Caprolactone is a widely used chemical intermediate. ε-Caprolactone can undergo ring-opening reactions catalyzed by a variety of compounds and can also be copolymerized with other monomers to synthesize polymers such as polycaprolactone (PCL), polycaprolactone polyols (PCL polyols), and polycaprolactone polyurethanes. PCL resin exhibits excellent shape memory properties, low-temperature flexibility, and hydrolysis resistance. It is non-toxic, harmless, and 100% biodegradable. It is an important polymer material with broad application prospects in absorbable surgical sutures, facial fillers, tissue engineering, artificial skin, medical dressings, resin bandages, fracture fixation, and dental sealants. Polycaprolactone polyols (PCL polyols), obtained by reacting ε-caprolactone with diisocyanates, can then be used to produce polycaprolactone-based polyurethanes, which are widely used in coatings and adhesives. In addition, ε-caprolactone can also be used as a strong solvent to dissolve many polymer resins, and has good solubility for some difficult-to-dissolve resins, such as chlorinated polyolefin resins and "ESTANE" polyurethane resins.

[0003] Currently, the main industrial large-scale production method for ε-caprolactone both domestically and internationally is the cyclohexanone oxidation process, using an organic peracid as the oxidant. This method has the advantages of strong oxidizing ability, high product yield, and abundant raw material resources. CN103570667B discloses a method for continuously preparing ε-caprolactone. A peroxycarboxylic acid solution and cyclohexanone are added to the first stirred tank of two to eight stirred tanks connected in series. The reaction materials are then overflowed from each tank until the last tank produces a solution containing ε-caprolactone. This method achieves high cyclohexanone conversion and high ε-caprolactone selectivity. However, this process requires a long reaction time and complex equipment.

[0004] Therefore, it is necessary to provide a new method and system for producing caprolactone, which has simple process equipment, low energy consumption, and high conversion rate and selectivity. Summary of the Invention

[0005] The present invention aims to provide a method and system for producing caprolactone, which has simple process equipment, low energy consumption, and high reaction conversion rate and selectivity.

[0006] To achieve the above-mentioned object, the technical solution adopted by the present invention is to provide a method for producing caprolactone, comprising the following steps: S1: continuously adding carboxylic acid, a catalyst, and a stabilizer to a high-gravity reactor through a first pipeline; continuously adding hydrogen peroxide to the high-gravity reactor through a second pipeline; and continuously adding a water-carrying agent to the high-gravity reactor after vaporizing the water-carrying agent through a third pipeline; S2: reacting the carboxylic acid and hydrogen peroxide in the high-gravity reactor under the action of the catalyst and stabilizer to generate peroxycarboxylic acid, the peroxycarboxylic acid reaction liquid containing the water-carrying agent, the catalyst, and the stabilizer entering a dehydration device for heating, dehydration, and separation, the azeotrope of the vaporized water-carrying agent and water is discharged, condensed, and separated by layers, the separated water-carrying agent is circulated back to the dehydration device, and the water is continuously removed; S3: the separated peroxycarboxylic acid reaction liquid is continuously discharged from the dehydration device, a portion of which is sent to the caprolactone reactor after dehydration, and the other portion is circulated into the high-gravity reactor for further reaction; S4: cyclohexanone is simultaneously added to the caprolactone reactor to react to obtain a crude caprolactone product, and the crude caprolactone is distilled and separated to obtain caprolactone.

[0007] Furthermore, the hydrogen peroxide in step S1 is hydrogen peroxide with a mass percentage of 35-70%, the catalyst is one or more of boric acid, sulfuric acid, nitric acid and nicotinic acid, the stabilizer is one or more of 8-hydroxyquinoline, tributyl phosphate, pyridinecarboxylic acid and 2-methylpyridine, the carboxylic acid is acetic acid, propionic acid or butyric acid, and the water-carrying agent is one or more of ethyl acetate, ethyl propionate, ethyl butyrate, propyl propionate and butyl acetate.

[0008] Furthermore, the molar ratio of carboxylic acid: water-carrying agent: stabilizer: catalyst: hydrogen peroxide is (921-961): (218-238): (0.8-1.2): (3.72-7.601): (205-341).

[0009] Furthermore, in step S1, after all materials are added, the high gravity reactor is evacuated to -0.07-0.1 MPa, and the temperature of the reaction liquid is controlled to 50-68°C.

[0010] Furthermore, the reaction temperature in step S4 is 40-70° C., and the reaction time is 3-5 hours.

[0011] Furthermore, in step S4, the molar ratio of peroxycarboxylic acid to cyclohexanone is: peroxycarboxylic acid:cyclohexanone = (1-1.2):1.

[0012] Furthermore, in step S3, the volume ratio of the reaction liquid sent to the caprolactone reactor after dehydration by anhydride and the reaction liquid circulated into the high-gravity reactor is 1:(1-20).

[0013] To achieve the above object, the present invention also provides a system for the above-mentioned production method of caprolactone, comprising a high-gravity reactor, a vaporizer, a dehydration device, a condenser, a stratifier, a caprolactone reactor and a distillation column, wherein the discharge port of the vaporizer is connected to the high-gravity reactor, the discharge port of the high-gravity reactor is respectively connected to the dehydration device and the condenser, the discharge port of the dehydration device is respectively connected to the condenser and the microchannel reactor, the discharge port of the condenser is connected to the stratifier, the discharge port of the stratifier is connected to the dehydration device, and the discharge port of the microchannel reactor is connected to the distillation column; carboxylic acid, catalyst, stabilizer and hydrogen peroxide react in the high-gravity reactor to form a peroxycarboxylic acid reaction liquid, and part of the water-containing steam is dissolved in the peroxycarboxylic acid reaction liquid. The peroxycarboxylic acid reaction liquid enters the dehydration device together with the liquid, and part of the water-carrying agent vapor directly enters the condenser with water; the dehydration device includes a top dehydration tower and a bottom reboiler; the peroxycarboxylic acid reaction liquid in the supergravity reactor enters the dehydration tower after coming out; the reboiler heats the peroxycarboxylic acid reaction liquid in the dehydration tower so that the azeotrope of the water-carrying agent and water is discharged from the top and then enters the condenser; the water-carrying agent vapor is condensed in the condenser and then enters the separator for separation, the lower layer of water is discharged, and the upper layer of water-carrying agent is refluxed to the dehydration tower; the peroxycarboxylic acid reaction liquid in the dehydration tower is pumped out from the bottom of the dehydration tower, and a part enters the caprolactone reactor to react with cyclohexanone, and the other part is circulated into the supergravity reactor; the crude caprolactone product obtained by the reaction in the caprolactone reactor enters the distillation tower for distillation to obtain caprolactone.

[0014] Furthermore, the high-gravity reactor includes a liquid phase feed port, a liquid phase discharge port, a liquid distributor, a packing layer, a rotor, a rotating shaft, a gas phase feed port and a gas phase discharge port. Carboxylic acid, catalyst and stabilizer are continuously fed from the liquid phase feed port to the liquid distributor via a first pipeline. Hydrogen peroxide is continuously fed from another liquid phase feed port to the liquid distributor via a second pipeline. The liquid is evenly distributed in the packing layer via the liquid distributor. The discharge port of the vaporizer is connected to the gas phase feed port of the high-gravity reactor. The vaporized water-carrying agent enters the gas phase feed port of the high-gravity reactor. The packing layer is made of a porous material and is used to increase the gas-liquid contact area. The rotor is fixed and drives the packing layer to rotate to simulate the hypergravity environment. The rotating shaft supports and drives the rotor to rotate. The top gas phase discharge port of the hypergravity reactor is connected to the inlet of the condenser. The water-containing steam enters the condenser after exiting the top gas phase discharge port of the hypergravity reactor. The bottom liquid phase discharge port of the hypergravity reactor is connected to the middle feed port of the dehydration tower. The peroxycarboxylic acid reaction liquid enters the dehydration tower through the middle feed port of the dehydration tower after exiting the bottom liquid phase discharge port of the hypergravity reactor.

[0015] Furthermore, the caprolactone reactor includes a microchannel reactor and a maturer. The peroxycarboxylic acid reaction liquid from the dehydration tower enters the microchannel reactor to react with cyclohexanone. The discharge port of the microchannel reactor is connected to the feed port of the maturer, and the discharge port of the maturer is connected to the feed port of the distillation tower. The reaction liquid after the reaction in the microchannel reactor enters the maturer to continue the reaction, and the crude caprolactone obtained after the reaction in the maturer enters the distillation tower for distillation.

[0016] Compared with the prior art, the present invention has the following beneficial effects: the production method and system of caprolactone provided by the present invention, in the presence of a catalyst and a stabilizer, a carboxylic acid and hydrogen peroxide are subjected to an oxidation reaction in a high-gravity reactor to obtain peroxycarboxylic acid. During the reaction process, the vaporized water-carrying agent is continuously used to azeotropically carry water to accelerate the removal of water from the reaction system. The peroxycarboxylic acid and cyclohexanone are then reacted to obtain caprolactone. At the same time, the peroxycarboxylic acid reaction liquid is continuously circulated into the high-gravity reactor for sufficient material contact reaction, thereby improving the conversion rate and utilization rate of hydrogen peroxide, making the conversion rate of hydrogen peroxide greater than 99% and the utilization rate greater than 90%. In a high-gravity environment, the molecular diffusion and interphase mass transfer processes between molecules of different sizes are much faster than those in a conventional gravity field, the microscopic mixing and mass transfer processes are greatly enhanced, and the production efficiency per unit equipment volume can be greatly improved; in addition, the vaporized water-carrying agent carries away water during the reaction, which is beneficial to the forward reaction, ensuring the smooth progress of the reaction, reducing the reaction time, and avoiding the decomposition of peroxycarboxylic acid caused by excessive reaction time. At the same time, the coupling technology of high-gravity reaction and distillation enhances the reaction mass transfer, improving the reaction conversion rate and selectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of the production process of caprolactone in an embodiment of the present invention;

[0018] Figure 2 Schematic diagram of a production system for caprolactone according to an embodiment of the present invention;

[0019] Figure 3 Schematic diagram of the production system of peroxycarboxylic acid in an embodiment of the present invention.

[0020] Reference numerals in the figures:

[0021] 1-carboxylic acid, 2-catalyst, 3-stabilizer, 4-water-carrying agent, 5-hydrogen peroxide, 6-vaporizer, 7-supergravity reactor, 8-dehydration tower, 9-reboiler, 10-condenser, 11-separator, 12-caprolactone reactor, 13-rectification tower, 71-first pipeline, 72-second pipeline, 73-third pipeline, 89-dehydration device. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to the accompanying drawings and examples.

[0023] See Figure 1 The method for producing caprolactone provided by the present invention comprises the following steps:

[0024] S1: continuously adding a carboxylic acid, a catalyst, and a stabilizer to a high-gravity reactor via a first pipeline; continuously adding hydrogen peroxide to the high-gravity reactor via a second pipeline; and continuously adding a water-carrying agent to the high-gravity reactor after vaporizing. Preferably, the hydrogen peroxide is 35-70% by weight, more preferably 50% by weight; the catalyst is one or more of boric acid, sulfuric acid, nitric acid, and nicotinic acid; the stabilizer is one or more of 8-hydroxyquinoline, tributyl phosphate, pyridinecarboxylic acid, and 2-methylpyridine; the carboxylic acid is acetic acid, propionic acid, or butyric acid; and the water-carrying agent is one or more of ethyl acetate, ethyl propionate, ethyl butyrate, propyl propionate, and butyl acetate. In a preferred embodiment, the molar ratio of carboxylic acid: water-carrying agent: stabilizer: catalyst: hydrogen peroxide is (921-961): (218-238): (0.8-1.2): (3.72-7.601): (205-341). After all materials are added to the high-gravity reactor, the pressure is evacuated to -0.07-0.1 MPa, and the temperature of the reaction solution is controlled to 50-68°C.

[0025] The hypergravity reactor simulates a hypergravity environment, where the acceleration is greater than that of the Earth's gravity (9.8 m / s 2 The forces exerted on matter in an environment with much greater gravity. In hypergravity, molecular diffusion and interphase mass transfer between molecules of different sizes are much faster than in conventional gravity. Microscopic mixing and mass transfer processes are greatly enhanced, increasing production efficiency per unit of equipment volume by 1-2 orders of magnitude.

[0026] S2: In the presence of a catalyst and stabilizer, carboxylic acid and hydrogen peroxide react in the high-gravity reactor to produce peroxycarboxylic acid (Product 1). The peroxycarboxylic acid reaction liquid, containing a water-carrying agent, catalyst, and stabilizer, enters a dehydration unit for heating, dehydration, and separation. The vaporized water-carrying agent and water form an azeotrope, which is then condensed and separated by layers. The separated water-carrying agent is then circulated back to the dehydration unit, carrying the water with it. The presence of water in the reaction system hinders the forward reaction process, and continuous water removal is necessary to ensure smooth reaction progress. However, prolonged reaction times can cause the peroxycarboxylic acid to decompose. Vaporized water-carrying agent facilitates rapid water removal, reducing reaction time and thus preventing peroxycarboxylic acid decomposition.

[0027] S3: The separated peroxycarboxylic acid reaction liquid is continuously discharged from the dehydration device. A portion is sent to the caprolactone reactor after dehydration, and the remaining portion is recycled into the supergravity reactor for further reaction. Specifically, the peroxycarboxylic acid reaction liquid is dehydrated by anhydride, and the volume ratio of the reaction liquid sent to the caprolactone reactor to the reaction liquid recycled into the supergravity reactor is preferably 1:(1-20). The peroxycarboxylic acid reaction liquid is continuously recycled into the supergravity reactor for sufficient material contact reaction, thereby improving the conversion rate and utilization rate of hydrogen peroxide.

[0028] S4: Cyclohexanone is simultaneously added to the caprolactone reactor to react to obtain a crude caprolactone product. The crude caprolactone is then distilled and separated to obtain caprolactone. Preferably, the molar ratio of peroxycarboxylic acid to cyclohexanone is (1-1.2):1, the reaction temperature is 40-70°C, and the reaction time is 3.5-4.5 hours.

[0029] See Figure 2 and Figure 3 To implement the above-mentioned method for producing caprolactone, the present invention provides a caprolactone production system, comprising a high-gravity reactor 7, a vaporizer 6, a dehydration device 89, a condenser 10, a stratifier 11, a caprolactone reactor 12, and a distillation tower 13. The top discharge port of the vaporizer 6 is connected to the high-gravity reactor 7, the discharge port of the high-gravity reactor 7 is connected to the dehydration device 89 and the condenser 10, respectively, the discharge port of the dehydration device 89 is connected to the condenser 10 and the caprolactone reactor 12, respectively, the discharge port of the condenser 10 is connected to the stratifier 11, the discharge port of the stratifier 11 is connected to the dehydration device 89, and the discharge port of the caprolactone reactor 12 is connected to the distillation tower 13.

[0030] After the carboxylic acid 1, catalyst 2, stabilizer 3 and hydrogen peroxide 5 react in the supergravity reactor 7 to form a peroxycarboxylic acid reaction liquid, part of the vapor of the water-carrying agent 4 is dissolved in the peroxycarboxylic acid reaction liquid and enters the dehydration device 89 together, and part of the vapor of the water-carrying agent 4 directly enters the condenser 10 with water.

[0031] The dehydration device 89 includes a top dehydration tower 8 and a bottom reboiler 9. The peroxycarboxylic acid reaction liquid in the high-gravity reactor 7 enters the dehydration tower 8 after exiting. The reboiler 9 heats the peroxycarboxylic acid reaction liquid in the dehydration tower 8 so that an azeotrope of the water-carrying agent and water is discharged from the top and then enters the condenser 10. The water-carrying agent vapor is condensed in the condenser 10 and then enters the separator 11 for separation. The lower layer of water is discharged, and the upper layer of the water-carrying agent is refluxed to the dehydration tower 8. This cycle continues, and the water in the reaction system is continuously discharged.

[0032] After the peroxycarboxylic acid reaction liquid in the dehydration tower 8 is pumped out from the bottom of the dehydration tower, a portion enters the caprolactone reactor 12 to react with cyclohexanone, and the other portion is circulated into the high-gravity reactor 7; the crude caprolactone product obtained by the reaction in the caprolactone reactor 12 enters the distillation tower 13 for distillation to obtain caprolactone (product 2).

[0033] The high-gravity reactor 7 includes a liquid-phase feed port, a liquid-phase discharge port, a liquid distributor, a packing layer, a rotor, a rotating shaft, a gas-phase feed port, and a gas-phase discharge port. The carboxylic acid 1, the catalyst 2, and the stabilizer 3 are continuously fed from the liquid-phase feed port to the liquid distributor via a first pipeline 71. The hydrogen peroxide 5 is continuously fed from another liquid-phase feed port to the liquid distributor via a second pipeline 72. The reaction liquid is uniformly distributed in the packing layer via the liquid distributor. The discharge port of the vaporizer 6 is connected to the gas-phase feed port of the high-gravity reactor 7. The water-carrying agent 4 enters the vaporizer 6 from the bottom feed port of the vaporizer 6 and is vaporized. The vaporized water-carrying agent 4 is discharged from the high-gravity reactor 7. 7 enters the packing layer through the gas phase feed port; the packing layer is made of a porous material and is used to increase the gas-liquid contact area. The rotor is fixed and drives the packing layer to rotate to simulate the hypergravity environment. The rotating shaft supports and drives the rotor to rotate; the top gas phase discharge port of the hypergravity reactor 7 is connected to the inlet of the condenser, and a portion of the steam with the water agent 4 directly enters the condenser 10 after coming out of the top gas phase discharge port of the hypergravity reactor 7. The bottom liquid phase discharge port of the hypergravity reactor 7 is connected to the middle feed port of the dehydration tower 8. The peroxycarboxylic acid reaction liquid enters the dehydration tower 8 from the middle feed port of the dehydration tower 8 after coming out of the bottom liquid phase discharge port of the hypergravity reactor 7.

[0034] In one specific embodiment, the caprolactone reactor 12 includes a microchannel reactor and a ripener. The peroxycarboxylic acid reaction liquid from the dehydration tower enters the microchannel reactor to react with cyclohexanone. The discharge port of the microchannel reactor is connected to the feed port of the ripener, which is in turn connected to the feed port of the distillation tower. The reaction liquid after the reaction in the microchannel reactor enters the ripener for further reaction. The crude caprolactone obtained after the reaction in the ripener enters the distillation tower for distillation and separation to obtain caprolactone. In other embodiments, a tubular reactor may be used instead of the microchannel reactor.

[0035] Example 1

[0036] In this example, a mixture of acetic acid, ethyl acetate, 8-hydroxyquinoline, boric acid, and 35% hydrogen peroxide (molar ratios of 921:218:0.8:3.72:205) was placed in a high-gravity reactor, evacuated to -0.07 MPa, and maintained at a temperature of 50°C for 3 hours. The resulting peracetic acid concentration was 11% by weight.

[0037] Example 2

[0038] In this example, propionic acid: propyl propionate: tributyl phosphate: sulfuric acid: 43% hydrogen peroxide were placed in a high-gravity reactor at a molar ratio of 931:223:0.9:4.69:239. The reactor was evacuated to -0.03 MPa, the reaction temperature was 55°C, and the reaction time was 3.5 hours. The resulting peroxypropionic acid concentration was 11.6%.

[0039] Example 3

[0040] In this example, propionic acid: ethyl propionate: 2-picoline: boric acid: 50% hydrogen peroxide were placed in a high-gravity reactor at a molar ratio of 941:228:1:5.66:273. The reactor was evacuated to 0.01 MPa, the reaction temperature was 60°C, and the reaction time was 4 hours. The resulting peroxypropionic acid concentration was 17% by mass.

[0041] Example 4

[0042] In this example, butyric acid: ethyl butyrate: pyridine carboxylic acid: nitric acid: 45% hydrogen peroxide were placed in a high-gravity reactor at a molar ratio of 951:233:1.1:6.63:307. The reactor was evacuated to 0.05 MPa, the reaction temperature was 64°C, and the reaction time was 4.5 hours. The resulting peroxybutyric acid concentration was 20% by mass.

[0043] Example 5

[0044] In this example, acetic acid: butyl acetate: 2-methylpyridine: nicotinic acid: 50% hydrogen peroxide (molar ratios of 961:238:1.2:7.601:341) was placed in a high-gravity reactor, evacuated to 0.1 MPa, and maintained at a temperature of 68°C for 5 hours. The resulting peracetic acid concentration was 22%.

[0045]

[0046] Example 6

[0047] In this embodiment, in step S4, the molar ratio of peroxycarboxylic acid to cyclohexanone is: peroxycarboxylic acid:cyclohexanone = 1:1, the reaction temperature is 40° C., and the reaction time is 3 hours.

[0048] Example 7

[0049] In this embodiment, in step S4, the molar ratio of peroxycarboxylic acid to cyclohexanone is: peroxycarboxylic acid:cyclohexanone=1.2:1, the reaction temperature is 70° C., and the reaction time is 4 hours.

[0050] Example 8

[0051] In this embodiment, in step S4, the molar ratio of peroxycarboxylic acid to cyclohexanone is: peroxycarboxylic acid:cyclohexanone=1.1:1, the reaction temperature is 55° C., and the reaction time is 5 hours.

[0052]

[0053] In summary, the present invention adopts oxidation reaction in a high-gravity reactor to obtain peroxycarboxylic acid, and continuously utilizes the water-carrying agent after vaporization to carry out azeotropic water in the reaction process to accelerate the speed of taking away water in the reaction system, and then the peroxycarboxylic acid and cyclohexanone are reacted to obtain caprolactone, and the peroxycarboxylic acid reaction solution is continuously circulated into the high-gravity reactor for sufficient material contact reaction, thereby being able to improve the conversion rate and utilization rate of hydrogen peroxide. At the same time, high-gravity reaction and distillation coupling technology strengthen reaction mass transfer, improve the reaction conversion rate and selectivity of cyclohexanone. While realizing industrialized continuous production, the present invention simplifies process equipment, improves production efficiency, and reduces production costs.

[0054] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the definition of the claims.

Claims

1. A method for producing caprolactone, characterized in that: The steps include: S1: continuously adding carboxylic acid, catalyst and stabilizer into the high-gravity reactor through the first pipeline; continuously adding hydrogen peroxide into the high-gravity reactor through the second pipeline; The water-carrying agent is vaporized and continuously added to the high-gravity reactor through the third pipeline; the catalyst is one or more of boric acid, sulfuric acid, nitric acid and nicotinic acid; after all materials are added, the high-gravity reactor is evacuated to -0.07-0.1Mpa, and the temperature of the reaction liquid is controlled to 50-68°C; S2: Under the action of a catalyst and a stabilizer, carboxylic acid and hydrogen peroxide react in the high-gravity reactor to generate peroxycarboxylic acid, and the peroxycarboxylic acid reaction liquid containing the water-carrying agent, the catalyst and the stabilizer enters a dehydration device for heating, dehydration and separation, and the vaporized water-carrying agent and water azeotrope are discharged and condensed and separated by layers; part of the water-carrying agent vapor is dissolved in the peroxycarboxylic acid reaction liquid and enters the dehydration device together, and part of the water-carrying agent vapor directly enters the condenser with water, and the separated water-carrying agent is circulated back to the dehydration device and continuously removed with water; S3: The separated peroxycarboxylic acid reaction liquid is continuously discharged from the dehydration device, a portion of which is sent to the caprolactone reactor after dehydration, and the other portion is recycled into the high-gravity reactor to continue the reaction; the volume ratio of the reaction liquid sent to the caprolactone reactor after dehydration by anhydride to the reaction liquid recycled into the high-gravity reactor is 1:(1-20); S4: Cyclohexanone is added to the caprolactone reactor to react to obtain a crude caprolactone product, which is then distilled and separated to obtain caprolactone; the molar ratio of peroxycarboxylic acid to cyclohexanone is: peroxycarboxylic acid:cyclohexanone = (1-1.2):

1.

2. The method for producing caprolactone according to claim 1, wherein: The hydrogen peroxide in step S1 is 35-70% by mass of hydrogen peroxide, the stabilizer is one or more of 8-hydroxyquinoline, tributyl phosphate, pyridinecarboxylic acid and 2-methylpyridine, the carboxylic acid is acetic acid, propionic acid or butyric acid, and the water-carrying agent is one or more of ethyl acetate, ethyl propionate, ethyl butyrate, propyl propionate and butyl acetate.

3. The method for producing caprolactone according to claim 2, wherein The molar ratio of each component is as follows: carboxylic acid: water-carrying agent: stabilizer: catalyst: hydrogen peroxide = (921-961): (218-238): (0.8-1.2): (3.72-7.601): (205-341).

4. The method for producing caprolactone according to claim 1, wherein: The reaction temperature in step S4 is 40-70° C., and the reaction time is 3-5 hours.

5. A system for the production method of caprolactone according to any one of claims 1 to 4, characterized in that: It includes a high-gravity reactor, a vaporizer, a dehydration device, a condenser, a stratifier, a caprolactone reactor and a distillation column. The discharge port of the vaporizer is connected to the high-gravity reactor, the discharge port of the high-gravity reactor is respectively connected to the dehydration device and the condenser, the discharge port of the dehydration device is respectively connected to the condenser and the microchannel reactor, the discharge port of the condenser is connected to the stratifier, the discharge port of the stratifier is connected to the dehydration device, and the discharge port of the microchannel reactor is connected to the distillation column; Carboxylic acid, catalyst, stabilizer and hydrogen peroxide react in a high-gravity reactor to form a peroxycarboxylic acid reaction liquid. Part of the water-carrying steam is dissolved in the peroxycarboxylic acid reaction liquid and enters the dehydration device together, while part of the water-carrying steam directly enters the condenser with water. The dehydration device includes a top dehydration tower and a bottom reboiler. The peroxycarboxylic acid reaction liquid in the supergravity reactor enters the dehydration tower after coming out. The reboiler heats the peroxycarboxylic acid reaction liquid in the dehydration tower so that the azeotrope of the water-carrying agent and water is discharged from the top and then enters the condenser. The water-carrying agent vapor is condensed in the condenser and then enters the separator for separation. The lower layer of water is discharged, and the upper layer of water-carrying agent is refluxed to the dehydration tower. The peroxycarboxylic acid reaction liquid in the dehydration tower is pumped out from the bottom of the dehydration tower, and a portion thereof enters the caprolactone reactor to react with cyclohexanone, and the other portion is circulated into the supergravity reactor; the crude caprolactone product obtained by the reaction in the caprolactone reactor enters the distillation tower for distillation to obtain caprolactone.

6. The system according to claim 5, wherein: The high-gravity reactor includes a liquid phase feed port, a liquid phase discharge port, a liquid distributor, a packing layer, a rotor, a rotating shaft, a gas phase feed port and a gas phase discharge port. Carboxylic acid, catalyst and stabilizer are continuously fed into the liquid distributor from the liquid phase feed port through a first pipeline. Hydrogen peroxide is continuously fed into the liquid distributor from another liquid phase feed port through a second pipeline. The liquid is evenly distributed in the packing layer through the liquid distributor. The discharge port of the vaporizer is connected to the gas phase feed port of the high-gravity reactor. The vaporized water-carrying agent enters the packing layer from the gas phase feed port of the high-gravity reactor. layer; the packing layer is made of porous material and is used to increase the gas-liquid contact area; the rotor is fixed and drives the packing layer to rotate to simulate the hypergravity environment, and the rotating shaft supports and drives the rotor to rotate; the top gas phase discharge port of the hypergravity reactor is connected to the inlet of the condenser, and the water-containing steam enters the condenser after exiting the top gas phase discharge port of the hypergravity reactor; the bottom liquid phase discharge port of the hypergravity reactor is connected to the middle feed port of the dehydration tower, and the peroxycarboxylic acid reaction liquid enters the dehydration tower through the middle feed port of the dehydration tower after exiting the bottom liquid phase discharge port of the hypergravity reactor.

7. The system according to claim 5, wherein: The caprolactone reactor includes a microchannel reactor and a maturer. The peroxycarboxylic acid reaction liquid from the dehydration tower enters the microchannel reactor to react with cyclohexanone. The discharge port of the microchannel reactor is connected to the feed port of the maturer, and the discharge port of the maturer is connected to the feed port of the distillation tower. The reaction liquid after the reaction in the microchannel reactor enters the maturer to continue the reaction. The crude caprolactone obtained after the reaction in the maturer enters the distillation tower for distillation.

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