System and method for preparing anhydrous peroxy acid with more than C3

Abstract

The invention belongs to the technical field of chemical synthesis, and particularly relates to a system and a method for preparing anhydrous peroxy acid with more than C3. The system comprises a reactive distillation dividing wall tower, the reactive distillation dividing wall tower comprises a reaction separation zone, a water zone, a tower top zone and a tower bottom zone, the reaction separation zone and the water zone are arranged between the tower top zone and the tower bottom zone, the reaction separation zone is provided with a raw material inlet, and the water zone is provided with a plurality of solvent inlets; the reaction separation area and the water-carrying area are separated through a NaA molecular sieve membrane assembly, and the bottom of the water-carrying area is of a closed structure. By adopting the system disclosed by the invention, water generated by reaction and water brought by hydrogen peroxide can be removed from the system in time, backmixing among reaction raw materials is reduced, the reaction rate is further increased, and meanwhile, the water content of peroxide at the tower bottom can be reduced, so that the retention time of the peroxide is shortened, and the energy consumption is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical synthesis, and in particular to a system and method for preparing anhydrous peroxyacids above C3, and in particular to a system and method for preparing anhydrous peroxyacids above C3 by using a reactive distillation bulkhead tower with an internally coupled NaA membrane. Background Art

[0002] Anhydrous peroxypropionic acid is the key raw material for oxidizing cyclohexanone to generate caprolactone. Current method mainly adopts hydrogen peroxide and organic acid reaction, and this reaction process has water to generate, and in the reaction process, if the reaction temperature cannot be strictly controlled, peroxide decomposition and explosion will occur. Although traditional reactive distillation can improve conversion efficiency, more plates and larger reflux ratio are also needed if the water content in peroxypropionic acid is reduced to ppm level, and the residence time of peroxide in the tower will also increase relatively, which will cause peroxide decomposition and explosion. In addition, if the moisture in peroxyacid is too much, polymerization side reaction will occur in the caprolactone synthesis polycaprolactone workshop section, resulting in poor selectivity of polycaprolactone.

[0003] CN102584775B and CN103570667B mention the production of peroxycarboxylic acid by reactive distillation. Although this operation mode can overcome the disadvantages of intermittent operation and produce peroxypropionic acid, when producing anhydrous peroxypropionic acid by reactive distillation, the water content requirement is too high, resulting in a long residence time of the peroxide, decomposition and explosion, and the problem of high energy consumption for obtaining anhydrous peroxypropionic acid is not solved. The production of peroxypropionic acid by slow heating and backpack reactive distillation proposed by CN202010904713.6, CN202010904726.3 and CN202010904683.9 can solve the problem of explosion caused by long residence time of peroxide or local high temperature, but cannot solve the problem of high energy consumption when preparing anhydrous peroxypropionic acid, and cannot take into account the problem of large investment in baffle tower equipment. Summary of the invention

[0004] The purpose of the present invention is to provide a system and method for preparing anhydrous peroxyacids above C3 in view of the problems that the prior art may cause decomposition and explosion due to the long residence time of peroxides, as well as high energy consumption and large equipment investment when preparing anhydrous peroxyacids. The system can directly separate water during the reaction process by replacing the partition between the reaction separation zone and the water zone in the reactive distillation bulkhead tower with a NaA molecular sieve membrane component, thereby reducing the back mixing between the reaction raw materials, thereby accelerating the reaction rate, and preventing the decomposition and explosion of the peroxide. At the same time, the bottom of the water zone is a closed structure to prevent the water in the water zone from entering the peroxide again, so that the water content of the peroxide at the bottom of the tower can be reduced, thereby shortening the residence time of the peroxide and reducing energy consumption.

[0005] The first aspect of the present invention provides a system for preparing anhydrous peroxyacids above C3, the system comprising a reaction distillation bulkhead tower, the reaction distillation bulkhead tower comprising a reaction separation zone, a water zone, a tower top zone and a tower bottom zone, the reaction separation zone and the water zone are arranged between the tower top zone and the tower bottom zone, the reaction separation zone has a raw material inlet, and the water zone has a plurality of solvent inlets, wherein the reaction separation zone and the water zone are separated by a NaA molecular sieve membrane assembly, the bottom of the reaction separation zone is connected to the tower bottom zone, and a gas phase distributor is arranged at the connection; the tops of the reaction separation zone and the water zone are both connected to the tower top zone, and a liquid phase distributor is arranged at the connection, and the bottom of the water zone is a closed structure.

[0006] Preferably, the number of the solvent inlets is 2 to 5. More preferably, the solvent inlet is connected to a solvent feed pipe for conveying the solvent into the water zone.

[0007] Preferably, a plurality of hydrogen peroxide inlets are provided on the side wall of the reaction and separation zone, and more preferably, the number of the hydrogen peroxide inlets is 2-5.

[0008] Preferably, the system further comprises a condenser and a phase separator, and the tower top zone is sequentially connected to the condenser and the phase separator via a connecting pipe.

[0009] Preferably, the solvent inlet is communicated with the phase separator for conveying the solvent output from the phase separator to the water-carrying zone.

[0010] Preferably, the number of plates arranged in the reaction and separation zone is 25-40.

[0011] Preferably, a packing layer is provided in the water zone. More preferably, the packing layer is a structured packing. Further preferably, the structured packing is a perforated plate corrugated packing, a plate mesh corrugated packing, a punctured plate corrugated packing, a wire mesh corrugated packing or a ring corrugated packing. Further preferably, the height of the structured packing is 3-5m.

[0012] Preferably, the system further comprises a reboiler and an anhydrous peroxyacid receiving tank, and the tower bottom zone is sequentially connected to the reboiler and the anhydrous peroxyacid receiving tank via a connecting pipe.

[0013] The second aspect of the present invention provides a method for preparing anhydrous peroxyacids of C3 or above, which is implemented in the above-mentioned system, and comprises: transporting an organic acid of C3 or above, hydrogen peroxide and a catalyst to the reaction separation zone through a raw material inlet for reaction, separating the product obtained by the reaction through the NaA molecular sieve membrane assembly, and the separated anhydrous peroxyacid solution enters the bottom zone of the tower through the gas phase distributor, and the separated water enters the water zone and forms an azeotropic mixture with the solvent injected through the solvent inlet, and the azeotropic mixture enters the top zone of the tower through the liquid phase distributor.

[0014] Preferably, the molar ratio of the organic acid to the hydrogen peroxide is 1.0-1.5:1.

[0015] Preferably, the concentration of the hydrogen peroxide is 10-90% by weight.

[0016] Preferably, the organic acid is propionic acid or butyric acid.

[0017] Preferably, based on the total weight of the organic acid, hydrogen peroxide and catalyst being 100 weight %, the content of the catalyst is 0.1-1 weight %.

[0018] Preferably, the catalyst is selected from one or more of sulfuric acid, phosphotungstic acid and boric acid.

[0019] Preferably, the solvent is selected from one or more of ethyl acetate, propyl acetate, isobutyl acetate, propyl propionate, isopropyl propionate, ethyl propionate, butyl acetate, n-ethane, methylene chloride and acetonitrile.

[0020] Preferably, the azeotropic mixture has an azeotropic temperature of 10-30°C.

[0021] Preferably, the feed temperature of the organic acid, hydrogen peroxide and catalyst is 20-30°C.

[0022] Preferably, the reaction conditions include: temperature of 30-60° C. and pressure of 5-20 kPa.

[0023] In the system for preparing anhydrous peroxyacids above C3 described in the present invention, by replacing the partition between the reaction separation zone and the water-carrying zone in the reaction distillation bulkhead tower with a NaA molecular sieve membrane assembly, the excellent water system permeation dehydration performance of the NaA molecular sieve membrane assembly is utilized to directly separate water during the reaction process, thereby timely removing the water generated by the reaction and the water brought in by hydrogen peroxide from the system, reducing the back mixing between the reaction raw materials, and thus accelerating the reaction rate. At the same time, the bottom of the water-carrying zone is a closed structure to prevent the water in the water-carrying zone from entering the peroxide again, so that the water content of the peroxide at the bottom of the tower can be reduced, thereby shortening the residence time of the peroxide and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of a system for preparing anhydrous peroxyacids above C3 according to one embodiment of the present invention.

[0025] Description of Reference Numerals

[0026] 1. Mixing feed pipe; 2. Hydrogen peroxide feed pipe; 3. Closed structure; 4. Liquid phase distributor; 5. NaA molecular sieve membrane assembly; 6. Gas phase distributor; 7. Packing layer; 8. Solvent feed pipe; 9. First connecting pipeline; 10. Second connecting pipeline; 11. Reboiler; 12. Phase separator; 13. Water extraction pipe; 14. Condenser; 15. Reaction distillation tower plate; 16. Anhydrous peracid receiving tank; 17. Reaction separation zone; 18. Water zone; 19. Tower top zone; 20. Tower bottom zone. DETAILED DESCRIPTION

[0027] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0028] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0029] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, unless otherwise specified, features defined as "first" and "second" may explicitly or implicitly include one or more of the features; "plurality" means two or more. The term "including" and any variation thereof means non-exclusive inclusion, and one or more other features, integers, steps, operations, units, components and / or combinations thereof may exist or be added.

[0030] In addition, terms indicating orientation or positional relationships such as "upper", "lower", "inside", and "outside" are described based on the orientation or relative positional relationships shown in the drawings, and are only for the convenience of describing the simplified description of the present application, and do not indicate that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0031] In addition, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internally connected between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] In a first aspect, the present invention provides a system for preparing anhydrous peroxyacids above C3, such as Figure 1 As shown, the system includes a reaction distillation bulkhead tower, which includes a reaction separation zone 17, a water zone 18, a tower top zone 19 and a tower bottom zone 20, wherein the reaction separation zone 17 and the water zone 18 are arranged between the tower top zone 19 and the tower bottom zone 20, the reaction separation zone 17 has a raw material inlet, and the water zone 18 has a plurality of solvent inlets, wherein the reaction separation zone 17 and the water zone 18 are separated by a NaA molecular sieve membrane component 5, the bottom of the reaction separation zone 17 is connected to the tower bottom zone 20, and a gas phase distributor 6 is arranged at the connection; the tops of the reaction separation zone 17 and the water zone 18 are both connected to the tower top zone 19, and a liquid phase distributor 4 is arranged at the connection, and the bottom of the water zone 18 is a closed structure 3.

[0033] In the system of the present invention, in a specific embodiment, the reaction separation zone 17 and the water zone 18 are located in the middle and upper part of the reaction distillation dividing wall tower.

[0034] In the system of the present invention, in a specific embodiment, a reactive distillation tray 15 is provided in the reactive separation zone 17. In a preferred embodiment, the reactive distillation tray 15 has 25-40 theoretical trays.

[0035] In the system of the present invention, in a specific embodiment, a raw material inlet is provided on the side wall of the reaction separation zone 17, and the raw material inlet is located at the upper part of the reaction separation zone 17. Specifically, the raw material inlet is located at the position of the 3rd to 5th theoretical plates of the reaction distillation tower plate 15.

[0036] In the system of the present invention, in a preferred embodiment, the raw material inlet is connected to the mixed feed pipe 1, which can more conveniently transport the organic acid, hydrogen peroxide and catalyst to the reaction separation zone 17. In the specific operation process, the organic acid, hydrogen peroxide and catalyst are transported from the raw material inlet to the reaction separation zone 17 through the mixed feed pipe 1 for reaction, and the feed temperature is 20-30° C., wherein the molar ratio of the amount of the organic acid to the amount of the hydrogen peroxide is controlled to be 1.0-1.5:1, and the total weight of the organic acid, hydrogen peroxide and the catalyst is 100 weight%, and the content of the catalyst is 0.1-1 weight%.

[0037] In the system of the present invention, the organic acid and hydrogen peroxide react on the plates of the reaction distillation tower under the action of a catalyst. As the reaction proceeds, hydrogen peroxide will be consumed. In order to prevent the hydrogen peroxide concentration from being too high, causing the decomposition of hydrogen peroxide and causing an explosion accident, it is necessary to replenish hydrogen peroxide in the reaction distillation tower. In a specific embodiment, a plurality of hydrogen peroxide inlets are provided on the side wall of the reaction separation zone 17. In a preferred embodiment, the number of the hydrogen peroxide inlets is 2-5, for example, 2, 3, 4 or 5. In a more preferred embodiment, the number of the hydrogen peroxide inlets is 2.

[0038] In the system of the present invention, in a specific embodiment, when the number of the hydrogen peroxide inlets is 2, the first hydrogen peroxide inlet is located in the middle of the reaction separation zone 17, specifically, it can be located at the position of the 10th to 15th theoretical plates of the reaction distillation tower plate 15, and the first hydrogen peroxide inlet is connected to a hydrogen peroxide feed pipe 2, so that the hydrogen peroxide can be more conveniently fed into the reaction separation zone 17. The feed temperature of the hydrogen peroxide is 30-40° C. Specifically, in order to control the concentration of hydrogen peroxide in the reaction separation zone 17 and the concentration of peroxy acid generated after the reaction, hydrogen peroxide needs to be added in the middle and bottom of the tower. The main purpose is to improve the conversion rate of organic acid, while preventing the excessive addition from causing the decomposition of hydrogen peroxide and causing explosion accidents, so the feed amount of hydrogen peroxide needs to be controlled. The second hydrogen peroxide inlet is located at the lower part of the reaction separation zone 17, specifically, it can be located at the position of the 20th-30th theoretical plate of the reaction distillation tower plate 15. The second hydrogen peroxide inlet is connected to another hydrogen peroxide feed pipe 2, which can more conveniently input the hydrogen peroxide into the reaction separation zone 17. The feed temperature of the hydrogen peroxide is 40-50°C.

[0039] In the system of the present invention, in a specific embodiment, the NaA molecular sieve membrane assembly 5 includes a NaA molecular sieve membrane. In this article, the source of the NaA molecular sieve membrane is not limited, and it can be purchased or prepared by a method in the prior art.

[0040] In the system of the present invention, in a preferred embodiment, the NaA molecular sieve membrane can be prepared according to the method of the document "Preparation of NaA molecular sieve membrane and its application in pyridine dehydration", Modern Chemical Industry, 2018, 38 (6) 110-1136, the preparation method uses sodium aluminate and alkaline silica sol as aluminum source and silicon source, and sets n (Na2O) ∶ n (SiO2) ∶ n (Al2O3) ∶ n (H2O) = 2 ∶ 2 ∶ 1 ∶ 150. Sodium aluminate and sodium hydroxide are dissolved in a 500 mL three-necked flask containing corresponding amounts of deionized water according to the molar ratio, and magnetically stirred at 30°C for 3 hours. During this process, alkaline silica sol is slowly added dropwise to obtain a synthetic solution for standby use.

[0041] In the system of the present invention, in a preferred embodiment, the NaA molecular sieve membrane is commercially available ZEBREX TM Series membranes (Sujiutian High-Tech Co., Ltd., Mitsubishi Chemical).

[0042] In the system of the present invention, in a preferred embodiment, the acute angle formed between the NaA molecular sieve membrane assembly 5 and the horizontal line is 60<α≤90°, for example, 60°, 70°, 80° or 90°.

[0043] In the system of the present invention, in a specific embodiment, the liquid phase distributor 4 can be a conventional choice in the art. In the specific operation process, in order to evaporate the maximum amount of water on the left and right sides of the next wall tower (i.e., the reaction separation zone 17 and the water zone 18), prevent flooding, maintain stable operation of the distillation tower, and ensure that the solvent (ethyl propionate) can reflux with water, the liquid phase distributor 4 is provided with uniform openings.

[0044] In the system of the present invention, in a specific embodiment, the closed structure 3 is a gas phase distributor, and no opening is provided on the gas phase distributor.

[0045] In the system of the present invention, in a specific embodiment, the gas phase distributor 6 can be a conventional choice in the art. During the specific operation, in order to prevent the anhydrous peracid solution produced in the reaction separation zone 17 from entering the water zone 18, thereby causing raw material loss, specifically, the gas phase distributor 6 is provided with uniform openings.

[0046] In the system of the present invention, in a specific embodiment, a packing layer 7 is provided in the water zone 18, and specifically, the packing layer 7 is a structured packing, and in this article, the structured packing can be a conventional choice in the art. In a preferred embodiment, the material in the structured packing is a perforated plate corrugated packing, a plate mesh corrugated packing, a perforated plate corrugated packing, a wire mesh corrugated packing or a ring corrugated packing. In a further embodiment, the height of the structured packing is 3-5m.

[0047] In the system of the present invention, the water generated in the reaction separation zone 17 and the water in the hydrogen peroxide pass through the NaA molecular sieve membrane assembly 5 and enter the water zone 18. In order to transport the water entering the water zone 18 to the tower top zone 19 and discharge it out of the system, and prevent the temperature of the reaction distillation wall tower from being too high, which may cause the decomposition of hydrogen peroxide and reduce the peroxy acid reaction rate, in a specific embodiment, a plurality of solvent inlets are provided on the side wall of the water zone 18. Specifically, the solvent inlet is located in the middle of the structured packing. In a preferred embodiment, the solvent inlet is connected to the solvent feed pipe 8 for transporting the solvent to the water zone 18.

[0048] In the system of the present invention, in a preferred embodiment, the number of the solvent inlets is 2-5, for example, 2, 3, 4 or 5. In a more preferred embodiment, the number of the solvent inlets is 2.

[0049] In the system of the present invention, in the specific operation process, the operating pressure of the main tower of the reactive distillation bulkhead tower is set to 5-20 kpa, preferably 10-15 kpa, and the organic acid above C3, hydrogen peroxide and the catalyst are transported to the reactive separation zone 17 through the mixed feed pipe 1. The organic acid and hydrogen peroxide react on the plates of the reactive distillation tower under the action of the catalyst. The hydrogen peroxide will be consumed during the reaction process, so it is necessary to replenish the hydrogen peroxide in time. The hydrogen peroxide feed pipe 2 is used to replenish the hydrogen peroxide to the reactive separation zone 17 in time. In this process, the peroxy acid product generated by the reaction enters the tower bottom zone 20 through the gas phase distributor 6, and the water generated by the reaction and the water in the hydrogen peroxide enter the water zone 18 through the NaA molecular sieve membrane component 5 with excellent water system osmotic dehydration performance, and are mixed with the solvent transported to the water zone 18 through the solvent feed pipe 8 to form an azeotrope. The azeotrope enters the tower top zone 19 through the liquid phase distributor 4, and the extraction temperature of the tower top zone 19 is 20-30°C.

[0050] In the system of the present invention, in a specific embodiment, the system further comprises a condenser 14 and a phase separator 12, and the tower top zone 19 is sequentially connected to the condenser 14 and the phase separator 12 through a connecting pipe. In a specific operation process, the azeotrope extracted from the tower top zone 19 enters the condenser 14 for condensation, and is phase-separated in the phase separator 12, with the upper layer being the solvent phase and the lower layer being the water phase.

[0051] In the system of the present invention, the solvent in the phase separator 12 can be recycled. In a specific embodiment, the solvent feed pipe 8 is connected to the phase separator 12 to allow the solvent output from the phase separator 12 to enter the water zone 18 through the solvent feed pipe 8.

[0052] In the system described in the present invention, in a specific embodiment, the several solvent feed pipes 8 can be connected through a first connecting pipe 10, and then the first connecting pipe 10 is connected to the phase separator 12, and the solvent output by the phase separator 12 is input into the water zone 18 through the solvent feed pipe 8.

[0053] In the system of the present invention, in a specific embodiment, the phase separator 12 has a water outlet. In a preferred embodiment, the water outlet is connected to the water sampling pipe 13 to sample the water in the phase separator 12.

[0054] In the system of the present invention, in a specific embodiment, the system further comprises a reboiler 11 and an anhydrous peroxyacid receiving tank 16, and the tower bottom zone 20 is sequentially connected to the reboiler 11 and the anhydrous peroxyacid receiving tank 16 through a connecting pipe. In a specific operation process, the peroxyacid product in the tower bottom zone 20 is extracted from the reboiler 11 as liquid, with a reboil ratio of 3-5:1, and is stored in the anhydrous peroxyacid receiver 16, specifically, the storage temperature is 0°C.

[0055] In the system of the present invention, in a specific embodiment, in order to obtain anhydrous peroxyacids above C3 and heat the organic acids above C3 at the bottom of the tower to enter the left side of the partition tower, and maintain stable operation of the distillation tower, a connection point is provided between the reboiler 11 and the anhydrous peroxyacid receiving tank 16, and the connection point is connected to the bottom zone 20 of the tower through a second connecting pipe 9.

[0056] According to a first embodiment of the present invention, the system for preparing anhydrous peroxyacids above C3 includes a reaction distillation bulkhead tower, the reaction distillation bulkhead tower includes a reaction separation zone 17, a water zone 18, a tower top zone 19 and a tower bottom zone 20, the reaction separation zone 17 and the water zone 18 are located between the tower top zone 19 and the tower bottom zone 20, the reaction separation zone 17 has a raw material inlet, and the water zone 18 has several solvent inlets, wherein the reaction separation zone 17 and the water zone 18 are separated by a NaA molecular sieve membrane assembly 5, the bottom of the reaction separation zone 17 is connected to the tower bottom zone 20, and a gas phase distributor 6 is provided at the connection; the tops of the reaction separation zone 17 and the water zone 18 are both connected to the tower top zone 19, and a liquid phase distributor 4 is provided at the connection, and the bottom of the water zone 18 is a closed structure 3.

[0057] According to a second embodiment of the present invention, the system for preparing anhydrous peroxyacids above C3 includes a reactive distillation bulkhead tower, the reactive distillation bulkhead tower includes a reaction separation zone 17, a water zone 18, a tower top zone 19 and a tower bottom zone 20, the reaction separation zone 17 and the water zone 18 are located between the tower top zone 19 and the tower bottom zone 20, the reaction separation zone 17 has a raw material inlet, and the water zone 18 has 2-5 solvent inlets, wherein the reaction separation zone 17 and the water zone 18 are separated by a NaA molecular sieve membrane assembly 5, the bottom of the reaction separation zone 17 is connected to the tower bottom zone 20, and a gas phase distributor 6 is provided at the connection; the tops of the reaction separation zone 17 and the water zone 18 are both connected to the tower top zone 19, and a liquid phase distributor 4 is provided at the connection, and the bottom of the water zone 18 is a closed structure 3; the solvent inlet is connected to a solvent feed pipe 8 for transporting the solvent to the water zone 18.

[0058] According to a third embodiment of the present invention, the system for preparing anhydrous peroxyacids above C3 includes a reaction distillation bulkhead tower, the reaction distillation bulkhead tower includes a reaction separation zone 17, a water zone 18, a tower top zone 19 and a tower bottom zone 20, the reaction separation zone 17 and the water zone 18 are located between the tower top zone 19 and the tower bottom zone 20, the reaction separation zone 17 has a raw material inlet, the water zone 18 has several solvent inlets, wherein the reaction separation zone 17 and the water zone 18 are separated by a NaA molecular sieve membrane assembly 5 The bottom of the reaction separation zone 17 is connected to the tower bottom zone 20, and a gas phase distributor 6 is provided at the connection; the tops of the reaction separation zone 17 and the water zone 18 are connected to the tower top zone 19, and a liquid phase distributor 4 is provided at the connection, and the bottom of the water zone 18 is a closed structure 3; the number of the solvent inlets is 2-5, and the solvent inlet is connected to the solvent feed pipe 8 for conveying the solvent to the water zone 18; a plurality of hydrogen peroxide inlets are provided on the side wall of the reaction separation zone (17).

[0059] According to a fourth embodiment of the present invention, the system for preparing anhydrous peroxyacids above C3 includes a reaction distillation bulkhead tower, the reaction distillation bulkhead tower includes a reaction separation zone 17, a water zone 18, a tower top zone 19 and a tower bottom zone 20, the reaction separation zone 17 and the water zone 18 are located between the tower top zone 19 and the tower bottom zone 20, the reaction separation zone 17 has a raw material inlet, and the water zone 18 has several solvent inlets, wherein the reaction separation zone 17 and the water zone 18 are separated by a NaA molecular sieve membrane assembly 5, and the bottom of the reaction separation zone 17 is connected to the tower bottom zone 20, A gas phase distributor 6 is provided at the connection; the tops of the reaction separation zone 17 and the water zone 18 are both connected to the tower top zone 19, and a liquid phase distributor 4 is provided at the connection, and the bottom of the water zone 18 is a closed structure 3; the number of the solvent inlets is 2-5, and the solvent inlet is connected to the solvent feed pipe 8 for conveying the solvent to the water zone 18; a plurality of hydrogen peroxide inlets are provided on the side wall of the reaction separation zone (17); the system also includes a condenser 14 and a phase separator 12, and the tower top zone 19 is connected to the condenser 14 and the phase separator 12 in sequence through a connecting pipe.

[0060] According to a fifth embodiment of the present invention, the system for preparing anhydrous peroxyacids above C3 includes a reaction distillation bulkhead tower, the reaction distillation bulkhead tower includes a reaction separation zone 17, a water zone 18, a tower top zone 19 and a tower bottom zone 20, the reaction separation zone 17 and the water zone 18 are located between the tower top zone 19 and the tower bottom zone 20, the reaction separation zone 17 has a raw material inlet, and the water zone 18 has several solvent inlets, wherein the reaction separation zone 17 and the water zone 18 are separated by a NaA molecular sieve membrane assembly 5, the bottom of the reaction separation zone 17 is connected to the tower bottom zone 20, and a gas phase distributor 6 is provided at the connection; the reaction separation zone 17 and the top of the water zone 18 are connected to the tower top zone 19, and a liquid phase distributor 4 is provided at the connection, and the bottom of the water zone 18 is a closed structure 3; the number of the solvent inlets is 2-5, and the solvent inlet is connected to the solvent feed pipe 8 for conveying the solvent to the water zone 18; a plurality of hydrogen peroxide inlets are provided on the side wall of the reaction separation zone (17); the system also includes a condenser 14 and a phase separator 12, and the tower top zone 19 is connected to the condenser 14 and the phase separator 12 in sequence through a connecting pipe; the solvent inlet is connected to the phase separator 12 for conveying the solvent output from the phase separator 12 to the water zone 18.

[0061] According to a sixth embodiment of the present invention, the system for preparing anhydrous peroxyacids above C3 includes a reaction distillation bulkhead tower, the reaction distillation bulkhead tower includes a reaction separation zone 17, a water zone 18, a tower top zone 19 and a tower bottom zone 20, the reaction separation zone 17 and the water zone 18 are located between the tower top zone 19 and the tower bottom zone 20, the reaction separation zone 17 has a raw material inlet, and the water zone 18 has several solvent inlets, wherein the reaction separation zone 17 and the water zone 18 are separated by a NaA molecular sieve membrane assembly 5, the bottom of the reaction separation zone 17 is connected to the tower bottom zone 20, and a gas phase distributor 6 is provided at the connection; the reaction separation zone 17 and the water zone 18 are connected to the tower bottom zone 20, and a gas phase distributor 6 is provided at the connection; The top is connected to the tower top zone 19, and a liquid phase distributor 4 is provided at the connection point. The bottom of the water zone 18 is a closed structure 3. The number of the solvent inlets is 2-5, and the solvent inlet is connected to the solvent feed pipe 8 for conveying the solvent to the water zone 18. A plurality of hydrogen peroxide inlets are provided on the side wall of the reaction separation zone (17). The system also includes a condenser 14 and a phase separator 12. The tower top zone 19 is connected to the condenser 14 and the phase separator 12 in sequence through a connecting pipe. The solvent inlet is connected to the phase separator 12 for conveying the solvent output from the phase separator 12 to the water zone 18. The number of plates provided in the reaction separation zone 17 is 25-40.

[0062] According to a seventh embodiment of the present invention, the system for preparing anhydrous peroxyacids above C3 includes a reaction distillation bulkhead tower, the reaction distillation bulkhead tower includes a reaction separation zone 17, a water zone 18, a tower top zone 19 and a tower bottom zone 20, the reaction separation zone 17 and the water zone 18 are located between the tower top zone 19 and the tower bottom zone 20, the reaction separation zone 17 has a raw material inlet, and the water zone 18 has several solvent inlets, wherein the reaction separation zone 17 and the water zone 18 are separated by a NaA molecular sieve membrane component 5, the bottom of the reaction separation zone 17 is connected to the tower bottom zone 20, and a gas phase distributor 6 is provided at the connection; the tops of the reaction separation zone 17 and the water zone 18 are both connected to the tower top zone 19, and a liquid phase distributor 4 is provided at the connection, and the bottom of the water zone 18 is a closed structure. Structure 3; the number of the solvent inlets is 2-5, and the solvent inlet is connected to the solvent feed pipe 8 for conveying the solvent to the water zone 18; a plurality of hydrogen peroxide inlets are arranged on the side wall of the reaction separation zone (17); the system also includes a condenser 14 and a phase separator 12, and the top zone 19 is connected to the condenser 14 and the phase separator 12 in sequence through a connecting pipe; the solvent inlet is connected to the phase separator 12 for conveying the solvent output by the phase separator 12 to the water zone 18; the number of tower plates arranged in the reaction separation zone 17 is 25-40; a packing layer 7 is arranged in the water zone 18, and the packing layer 7 is a structured packing, and the structured packing is a perforated plate corrugated packing, a plate mesh corrugated packing, a perforated plate corrugated packing, a wire mesh corrugated packing or a ring corrugated packing, and the height of the structured packing is 3-5m.

[0063] According to an eighth embodiment of the present invention, the system for preparing anhydrous peroxyacids above C3 includes a reactive distillation bulkhead tower, the reactive distillation bulkhead tower includes a reaction separation zone 17, a water zone 18, a tower top zone 19 and a tower bottom zone 20, the reaction separation zone 17 and the water zone 18 are located between the tower top zone 19 and the tower bottom zone 20, the reaction separation zone 17 has a raw material inlet, and the water zone 18 has several solvent inlets, wherein the reaction separation zone 17 and the water zone 18 are separated by a NaA molecular sieve membrane assembly 5, the bottom of the reaction separation zone 17 is connected to the tower bottom zone 20, and a gas phase distributor 6 is provided at the connection; the tops of the reaction separation zone 17 and the water zone 18 are both connected to the tower top zone 19, and a liquid phase distributor 4 is provided at the connection, and the bottom of the water zone 18 is a closed structure 3; the number of the solvent inlets is 2-5, and the solvent inlet is connected to the solvent feed pipe 8 The system further comprises a condenser 14 and a phase separator 12, wherein the tower top zone 19 is sequentially connected to the condenser 14 and the phase separator 12 through a connecting pipe; the solvent inlet is connected to the phase separator 12, and is used to transport the solvent output by the phase separator 12 to the water zone 18; the number of plates arranged in the reaction separation zone 17 is 25-40; a packing layer 7 is arranged in the water zone 18, wherein the packing layer 7 is a structured packing, wherein the structured packing is a perforated plate corrugated packing, a plate mesh corrugated packing, a punctured plate corrugated packing, a wire mesh corrugated packing or a ring corrugated packing, and the height of the structured packing is 3-5m; the system further comprises a reboiler 11 and an anhydrous peroxyacid receiving tank 16, wherein the tower bottom zone 20 is sequentially connected to the reboiler 11 and the anhydrous peroxyacid receiving tank 16 through a connecting pipe.

[0064] The second aspect of the present invention provides a method for preparing anhydrous peroxyacids of C3 or above, which is implemented in the above-mentioned system, and comprises: transporting an organic acid of C3 or above, hydrogen peroxide and a catalyst to the reaction separation zone 17 through a raw material inlet for reaction, separating the product obtained by the reaction through the NaA molecular sieve membrane assembly 5, and the separated anhydrous peroxyacid solution enters the bottom zone 20 through the gas phase distributor 6, and the separated water enters the water zone 18 and forms an azeotropic mixture with the solvent injected through the solvent inlet, and the azeotropic mixture enters the top zone 19 through the liquid phase distributor 4.

[0065] In the method of the present invention, in a specific embodiment, the molar ratio of the organic acid to the hydrogen peroxide is 1.0-1.5:1, for example, it can be 1.0:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1 or 1.5:1.

[0066] In the method of the present invention, in a specific embodiment, the concentration of the hydrogen peroxide is 10-90% by weight. In a preferred embodiment, the concentration of the hydrogen peroxide is 25-50% by weight.

[0067] In the method of the present invention, in a preferred embodiment, the organic acid is propionic acid or butyric acid.

[0068] In the method of the present invention, in a specific embodiment, based on the total weight of the organic acid, hydrogen peroxide and catalyst as 100 weight%, the content of the catalyst is 0.1-1.0 weight%, for example, it can be 0.1 weight%, 0.2 weight%, 0.4 weight%, 0.6 weight%, 0.8 weight% or 1.0 weight%. In a preferred embodiment, based on the total weight of the organic acid, hydrogen peroxide and catalyst as 100 weight%, the content of the catalyst is 0.4-0.8 weight%.

[0069] In the method of the present invention, in a specific embodiment, the catalyst is selected from one or more of sulfuric acid, phosphotungstic acid and boric acid.

[0070] In the system of the present invention, in order to make the water entering the water zone 18 be discharged from the system more efficiently and to recover the solvent better, a solvent that can form an oil-water two-phase substance with water after cooling should be used. In a specific embodiment, the solvent is selected from one or more of ethyl acetate, propyl acetate, isobutyl acetate, propyl propionate, isopropyl propionate, ethyl propionate, butyl acetate, n-ethane, methylene chloride, and acetonitrile.

[0071] In the method of the present invention, in a specific embodiment, the azeotropic temperature of the azeotropic mixture is 10-30°C.

[0072] In the method of the present invention, in a specific embodiment, the feed temperature of the organic acid, hydrogen peroxide and catalyst is 20-30°C.

[0073] In the method of the present invention, in a specific embodiment, the reaction conditions include: temperature of 30-60°C and pressure of 5-20kPa.

[0074] The following examples further illustrate the system and method for preparing C3 or higher anhydrous peroxyacids of the present invention. The examples are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following examples.

[0075] ZEBREX TM Series membrane, manufacturer: Su Jiutian High-Tech Co., Ltd.

[0076] like Figure 1As shown, the embodiments and comparative examples are implemented in the following system for preparing anhydrous peroxyacids of C3 or more, wherein the system for preparing anhydrous peroxyacids of C3 or more comprises a reaction distillation bulkhead tower, a reboiler 11, a phase separator 12 and a condenser 14, wherein the reaction distillation bulkhead tower comprises a reaction separation zone 17, a water zone 18, a tower top zone 19 and a tower bottom zone 20, wherein the reaction separation zone 17 and the water zone 18 are arranged between the tower top zone 19 and the tower bottom zone 20, wherein the tower top zone 19 is connected to the condenser 14 and the phase separator 12 in sequence through a connecting pipe, and the tower bottom zone 20 is connected to the reboiler 11, wherein the reaction separation zone 17 and the water zone 18 are separated by a vertical NaA molecular sieve membrane assembly 5, and the NaA molecular sieve membrane assembly 5 is made of ZEBREX TM(NaA molecular sieve membrane); the tops of the reaction separation zone 17 and the water zone 18 are connected to the tower top zone 19, and a liquid phase distributor 4 is provided at the connection, the liquid phase distributor 4 is provided with an opening, and the liquid phase distributor 4 is perpendicular to the NaA molecular sieve membrane assembly 5; the bottom of the reaction separation zone 17 is connected to the tower bottom zone 20, and a gas phase distributor 6 is provided at the connection, the gas phase distributor 6 is perpendicular to the NaA molecular sieve membrane assembly 5, and the bottom of the water zone 18 is separated from the tower bottom zone 20 by a closed gas phase distributor The reaction separation zone 17 contains a reaction distillation tray 15, and the number of theoretical trays of the reaction distillation tray 15 is 30; a raw material inlet is provided on the side wall of the reaction separation zone 17, and the raw material inlet is located at the third theoretical tray in the reaction separation zone 17, and the raw material inlet is connected to the mixed feed pipe 1, and is used to transport the organic acid, hydrogen peroxide and catalyst to the reaction separation zone 17; two hydrogen peroxide inlets are provided on the side wall of the reaction separation zone 17, and the first hydrogen peroxide inlet is located at the 10th theoretical tray in the reaction separation zone 17, and the first hydrogen peroxide inlet is located at the 10th theoretical tray in the reaction separation zone 17. The hydrogen peroxide inlet is connected to a hydrogen peroxide feed pipe 2, and the second hydrogen peroxide inlet is located at the 20th theoretical plate in the reaction separation zone 17, and the second hydrogen peroxide inlet is connected to another hydrogen peroxide feed pipe 2; the water zone 18 contains a structured packing layer 7 whose filler is a perforated plate corrugated packing, and the height of the structured packing is 3m; two solvent inlets are arranged on the side wall of the water zone 18, the first solvent inlet is located in the middle of the packing layer 7, the first solvent inlet is connected to a solvent feed pipe 8, which is used to transport the solvent to the water zone 18, and the second solvent inlet is located at the middle of the packing layer 7. At the lower part of the packing layer 7, the second solvent inlet is connected to another solvent feed pipe 8 for conveying the solvent to the water zone 18; the solvent feed pipe 8 is connected to the first connecting pipe 10, and the first connecting pipe 10 is connected to the phase separator 12, for inputting the solvent output by the phase separator 12 into the water zone 18 through the solvent feed pipe 8; the system also includes an anhydrous peroxyacid receiving tank 16, and the anhydrous peroxyacid receiving tank 16 is connected to the reboiler 11; the phase separator 12 has a water outlet, and the water outlet is connected to the moisture extraction pipe 13.

[0077] Example 1

[0078] The method for preparing anhydrous peroxypropionic acid comprises:

[0079] The operating pressure of the reactive distillation dividing wall tower is set to 15 kPa, and the tower top temperature is set to 30° C. A raw material mixture containing 72% propionic acid, 28% hydrogen peroxide (hydrogen peroxide concentration is 50%), 4.6 kg in total, and about 0.028 kg of 98% sulfuric acid is transported to the reaction separation zone 17 through the mixed feed pipe 1. The feed flow rate of the raw material mixture is controlled to be 4.6 kg / h, and the feed temperature is controlled to be 25° C. Propionic acid and hydrogen peroxide react under the catalytic action of sulfuric acid to generate peroxypropionic acid. During the reaction, hydrogen peroxide (50%) with a feed flow rate of 0.2 kg / h and a feed temperature of 35° C. is fed into the reaction separation zone 17 through the first hydrogen peroxide inlet through a hydrogen peroxide feed pipe 2, and then hydrogen peroxide (50%) with a feed flow rate of 0.2 kg / h and a feed temperature of 45° C. is fed into the reaction separation zone 17 through another hydrogen peroxide feed pipe 2. %) is input into the reaction separation zone 17 through the second hydrogen peroxide inlet; the water generated by the reaction and the water in the hydrogen peroxide enter the water zone 18 through the NaA molecular sieve membrane assembly 5, and then ethyl propionate is input into the water zone 18 through the solvent feed pipe 8, the water in the water zone 18 forms an azeotropic mixture with ethyl propionate, and then enters the tower top zone 19 through the liquid phase distributor 4, and finally condensed in the condenser 14 in turn, layered in the phase separator 12, the ethyl propionate in the upper layer is refluxed to the water zone 18 through the solvent feed pipe 8, and the water in the lower layer is discharged from the water outlet through the moisture extraction pipe 13; the anhydrous peroxypropionic acid synthetic solution generated by the reaction passes through the gas phase distributor 6 to reach the tower bottom zone 20, and then the liquid is extracted through the reboiler 11, the reboiling ratio is 3:1, and stored in the anhydrous peroxyacid receiver 16 at 0°C. The flow rate of the obtained anhydrous peroxypropionic acid was 1.297 kg / h, the water content of the anhydrous peroxypropionic acid was 2800 ppm, the conversion rate of hydrogen peroxide was 98.97%, and the yield of anhydrous peroxypropionic acid was 99.01%.

[0080] Example 2

[0081] The method of Example 1 was followed, except that ZEBREX TM (NaA molecular sieve membrane) was replaced with NaA molecular sieve membrane produced by SMT Co. The flow rate of anhydrous peroxypropionic acid obtained was 1.30 kg / h, the water content of anhydrous peroxypropionic acid was 3000 ppm, the conversion rate of hydrogen peroxide was 98%, and the yield of anhydrous peroxypropionic acid was 98.03%.

[0082] Example 3

[0083] The method of Example 1 was followed, except that ZEBREX TM(NaA molecular sieve membrane) was replaced with a NaA molecular sieve membrane prepared according to the document "Preparation of NaA molecular sieve membrane and its application in pyridine dehydration". The flow rate of anhydrous peroxypropionic acid obtained was 1.31 kg / h, the water content of anhydrous peroxypropionic acid was 2500 ppm, the hydrogen peroxide conversion rate was 98.22%, and the yield of anhydrous peroxypropionic acid was 98.26%.

[0084] Example 4

[0085] The method of Example 1 was followed, except that the acute angle formed between the NaA molecular sieve membrane assembly 5 and the horizontal line was 60°. The flow rate of the obtained anhydrous peroxypropionic acid was 1.315 kg / h, the water content of the anhydrous peroxypropionic acid was 2500 ppm, the hydrogen peroxide conversion rate was 99.35%, and the anhydrous peroxypropionic acid yield was 99.39%.

[0086] Example 5

[0087] The method of Example 1 was followed, except that the filler in the structured packing layer 7 was replaced with a wire mesh corrugated packing. The flow rate of the obtained anhydrous peroxypropionic acid was 1.298 kg / h, the water content of the anhydrous peroxypropionic acid was 2900 ppm, the hydrogen peroxide conversion rate was 98.07%, and the anhydrous peroxypropionic acid yield was 98.11%.

[0088] Example 6

[0089] The process was carried out in the same manner as in Example 1, except that ethyl propionate was replaced by dichloromethane. The flow rate of the obtained anhydrous peroxypropionic acid was 1.305 kg / h, the water content of the anhydrous peroxypropionic acid was 3000 ppm, the conversion rate of hydrogen peroxide was 98.6%, and the yield of anhydrous peroxypropionic acid was 98.64%.

[0090] Example 7

[0091] The method was implemented in the same manner as in Example 1, except that a hydrogen peroxide inlet was provided on the side wall of the reaction separation zone 17, the hydrogen peroxide inlet was located at the 15th theoretical plate in the reaction separation zone 17, the hydrogen peroxide inlet was connected to the hydrogen peroxide feed pipe 2, and hydrogen peroxide (50%) with a feed flow rate of 0.4 kg / h and a feed temperature of 40° C. was fed into the reaction separation zone 17 through the hydrogen peroxide feed pipe 2. The flow rate of the obtained anhydrous peroxypropionic acid was 1.296 kg / h, the water content of the anhydrous peroxypropionic acid was 3200 ppm, the hydrogen peroxide conversion rate was 97.92%, and the anhydrous peroxypropionic acid yield was 99.96%.

[0092] Example 8

[0093] The process was carried out in the same manner as in Example 1, except that the operating pressure of the reactive distillation dividing wall tower was set to 20 kPa and the tower top temperature was set to 40.2° C. The flow rate of the obtained anhydrous peroxypropionic acid was 1.29 kg / h, the water content of the anhydrous peroxypropionic acid was 2000 ppm, the hydrogen peroxide conversion rate was 97.47%, and the anhydrous peroxypropionic acid yield was 97.5%.

[0094] Example 9

[0095] The method of Example 1 is followed, except that a raw material mixture containing 69% propionic acid, 31% hydrogen peroxide (hydrogen peroxide concentration of 50%), 4.6 kg in total, and about 0.037 kg of 98% sulfuric acid is transported to the reaction separation zone 17 through the mixing feed pipe 1. The flow rate of the obtained anhydrous peroxy propionic acid is 1.292 kg / h, the water content of the anhydrous peroxy propionic acid is 2000 ppm, the hydrogen peroxide conversion rate is 97.62%, and the anhydrous peroxy propionic acid yield is 97.66%.

[0096] Example 10

[0097] The method of Example 1 is implemented, except that a raw material mixture containing 77% propionic acid, 23% hydrogen peroxide (hydrogen peroxide concentration is 50%), 4.6 kg in total, and 98% sulfuric acid, about 0.048 kg, is transported to the reaction separation zone 17 through the mixing feed pipe 1. The flow rate of the obtained anhydrous peroxy propionic acid is 1.82 kg / h, the water content of the anhydrous peroxy propionic acid is 3000 ppm, the hydrogen peroxide conversion rate is 98.55%, and the anhydrous peroxy propionic acid yield is 95.58%.

[0098] Embodiment 11

[0099] The method of Example 1 is followed, except that a raw material mixture containing 76% butyric acid by mass, 4.6 kg of 24% hydrogen peroxide (hydrogen peroxide concentration is 50%) and about 0.028 kg of 98% nitric acid is transported to the reaction separation zone 17 through the mixing feed pipe 1. The flow rate of the obtained anhydrous peroxybutyric acid is 1.5 kg / h, the water content of the anhydrous peroxybutyric acid is 2800 ppm, the hydrogen peroxide conversion rate is 98.07%, and the anhydrous peroxybutyric acid yield is 98.04%.

[0100] Comparative Example 1

[0101] The method of Example 1 was followed, except that the NaA molecular sieve membrane assembly 5 was replaced with a zirconium oxide ceramic separation membrane. The flow rate of the obtained anhydrous peroxy acid was 0.8 kg / h, the water content of the anhydrous peroxy propionic acid was 2%, the hydrogen peroxide conversion rate was 60.44%, and the anhydrous peroxy propionic acid yield was 60.47%.

[0102] Comparative Example 2

[0103] The method of Example 1 was followed, except that the bottom of the water zone 18 had an opening. The flow rate of the obtained anhydrous peroxy acid was 1.0 kg / h, the water content of the anhydrous peroxy acid was 1%, the hydrogen peroxide conversion rate was 75.55%, and the anhydrous peroxy propionic acid yield was 75.75%.

[0104] Comparative Example 3

[0105] The method of Example 1 was followed, except that no gas phase distributor was provided at the connection between the bottom of the reaction separation zone and the tower bottom zone. The flow rate of the obtained anhydrous peroxy acid was 0.9 kg / h, the water content of the anhydrous peroxy acid was 1.5%, the conversion rate of hydrogen peroxide was 68%, and the yield of peroxypropionic acid was 68.02%.

[0106] Comparative Example 4

[0107] The method of Example 1 was followed, except that no liquid phase distributor was provided at the connection between the top of the reaction separation zone and the water zone and the tower top zone. The flow rate of the obtained anhydrous peroxy acid was 1.0 kg / h, the water content of the anhydrous peroxy acid was 1%, the conversion rate of hydrogen peroxide was 75.55%, and the yield of peroxypropionic acid was 75.59%.

[0108] It can be seen from the above embodiments that the system for preparing anhydrous peroxyacid of the present invention can realize direct separation of water during the reaction process, reduce the back mixing between the reaction raw materials, thereby accelerating the reaction rate, preventing the decomposition and explosion of the peroxide, and at the same time can reduce the water content of the peroxide at the bottom of the tower to 3500ppm, thereby shortening the residence time of the peroxide, reducing energy consumption, and making the conversion rate of hydrogen peroxide reach more than 97%, and the yield of anhydrous peroxyacid reach more than 95%.

[0109] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A system for preparing anhydrous peroxyacids of C3 or above, characterized in that: The system comprises a reaction distillation bulkhead tower, wherein the reaction distillation bulkhead tower comprises a reaction separation zone (17), a water zone (18), a tower top zone (19) and a tower bottom zone (20), wherein the reaction separation zone (17) and the water zone (18) are located between the tower top zone (19) and the tower bottom zone (20), wherein the reaction separation zone (17) has a raw material inlet, and the water zone (18) has a plurality of solvent inlets, wherein the reaction separation zone (17) and the water zone (18) are separated by a NaA molecular sieve membrane assembly (5), wherein the bottom of the reaction separation zone (17) is connected to the tower bottom zone (20), and a gas phase distributor (6) is provided at the connection; wherein the tops of the reaction separation zone (17) and the water zone (18) are both connected to the tower top zone (19), and a liquid phase distributor (4) is provided at the connection, and the bottom of the water zone (18) is a closed structure (3).

2. The system according to claim 1, characterized in that The number of the solvent inlets is 2-5; Preferably, the solvent inlet is connected to a solvent feed pipe (8) for conveying the solvent into the water zone (18).

3. The system according to claim 1 or 2, characterized in that: A plurality of hydrogen peroxide inlets are provided on the side wall of the reaction and separation zone (17); Preferably, the number of the hydrogen peroxide inlets is 2-5.

4. The system according to any one of claims 1 to 3, characterized in that: The system further comprises a condenser (14) and a phase separator (12), and the tower top zone (19) is connected to the condenser (14) and the phase separator (12) in sequence through a connecting pipe.

5. The system according to claim 4, characterized in that The solvent inlet is in communication with the phase separator (12) and is used for conveying the solvent output from the phase separator (12) to the water-carrying zone (18).

6. The system according to any one of claims 1 to 5, characterized in that: The number of plates arranged in the reaction and separation zone (17) is 25-40.

7. The system according to any one of claims 1 to 6, characterized in that: A packing layer (7) is provided in the water zone (18); Preferably, the packing layer (7) is a structured packing; Preferably, the structured packing is a perforated plate corrugated packing, a plate mesh corrugated packing, a perforated plate corrugated packing, a wire mesh corrugated packing or annular corrugated packing; Preferably, the height of the structured packing is 3-5m.

8. The system according to any one of claims 1 to 7, characterized in that: The system further comprises a reboiler (11) and an anhydrous peroxyacid receiving tank (16), and the tower bottom zone (20) is connected to the reboiler (11) and the anhydrous peroxyacid receiving tank (16) in sequence through a connecting pipe.

9. A method for preparing anhydrous peroxyacids of C3 or above, the method being implemented in the system according to any one of claims 1 to 8, characterized in that: The method comprises: transporting an organic acid of C3 or above, hydrogen peroxide and a catalyst to the reaction separation zone (17) through a raw material inlet for reaction; separating the product obtained by the reaction through the NaA molecular sieve membrane assembly (5); the anhydrous peroxy acid solution obtained by separation enters the tower bottom zone (20) through the gas phase distributor (6); the separated water enters the water zone (18) and forms an azeotropic mixture with the solvent injected through the solvent inlet; and the azeotropic mixture enters the tower top zone (19) through the liquid phase distributor (4).

10. The method according to claim 9, characterized in that The molar ratio of the organic acid to the hydrogen peroxide is 1.0-1.5:1; Preferably, the concentration of the hydrogen peroxide is 10-90% by weight; Preferably, the organic acid is propionic acid or butyric acid.

11. The method according to claim 9 or 10, characterized in that: Based on the total weight of the organic acid, hydrogen peroxide and the catalyst being 100 weight percent, the content of the catalyst is 0.1-1 weight percent; Preferably, the catalyst is selected from one or more of sulfuric acid, phosphotungstic acid and boric acid.

12. The method according to any one of claims 9 to 11, characterized in that: The solvent is selected from one or more of ethyl acetate, propyl acetate, isobutyl acetate, propyl propionate, isopropyl propionate, ethyl propionate, butyl acetate, n-ethane, methylene chloride and acetonitrile.

13. The method according to claim 12, characterized in that The azeotropic temperature of the azeotropic mixture is 10-30°C.

14. The method according to any one of claims 9 to 13, characterized in that: The feed temperature of the organic acid, hydrogen peroxide and catalyst is 20-30°C.

15. The method according to any one of claims 9 to 13, characterized in that: The reaction conditions include: temperature of 30-60° C. and pressure of 5-20 kPa.

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