A system and method for preparing anhydrous peroxyacids above C3

Abstract

The present invention belongs to the field of chemical synthesis technology, and specifically relates to a system and method for preparing anhydrous peroxyacids with a C3 or higher content. The system includes a reactive distillation bulkhead tower, which includes 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 several solvent inlets. The reaction separation zone and the water zone are separated by a NaA molecular sieve membrane assembly, and the bottom of the water zone is a closed structure. The system described in the present invention can promptly remove water produced by the reaction and water introduced by hydrogen peroxide from the system, reducing back-mixing between the reaction raw materials, thereby accelerating the reaction rate, and at the same time reducing the water content of the peroxide at the bottom of the tower, thereby shortening the residence time of the peroxide and reducing energy consumption.

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 with C3 or higher, and more particularly to a system and method for preparing anhydrous peroxyacids with C3 or higher by utilizing a reactive distillation bulkhead tower coupled with an internal NaA membrane. Background Art

[0002] Anhydrous peroxypropionic acid is the key raw material for oxidizing cyclohexanone to generate caprolactone. Current methods mainly adopt 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, the peroxide decomposition and explosion will occur. Although traditional reactive distillation can improve conversion efficiency, if the water content in peroxypropionic acid is reduced to the ppm level, more trays and a larger reflux ratio are also required, and the residence time of peroxide in the tower will also increase relatively, which will cause the peroxide decomposition and explosion. In addition, if the moisture in peroxyacid is too much, then in the caprolactone synthesis polycaprolactone workshop section, polymerization side reactions will occur, resulting in poor polycaprolactone selectivity.

[0003] CN102584775B and CN103570667B mention the use of reactive distillation to produce peroxycarboxylic acid. Although this operation mode can overcome the shortcomings 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. CN202010904713.6, CN202010904726.3 and CN202010904683.9 propose the use of slow heating and backpack reactive distillation to produce peroxypropionic acid. Although this method can solve the problem of explosion caused by excessively long residence time of the peroxide or local high temperature, it cannot solve the problem of high energy consumption when preparing anhydrous peroxypropionic acid, and it cannot take into account the problem of large investment in baffle tower equipment. Summary of the Invention

[0004] The present invention aims to address the problems of prior art in preparing anhydrous peroxyacids, such as long peroxide residence time, which can lead to decomposition and explosion, as well as high energy consumption and large equipment investment. The present invention provides a system and method for preparing anhydrous peroxyacids having a C3 or higher content. By replacing the partition between the reaction separation zone and the water-carrying zone in a reactive distillation bulkhead tower with a NaA molecular sieve membrane assembly, the system can directly separate water during the reaction process, reducing back-mixing between the reaction raw materials, thereby accelerating the reaction rate and preventing decomposition and explosion of the peroxide. Furthermore, the bottom of the water-carrying zone is a closed structure, preventing water in the water-carrying zone from re-entering the peroxide. This reduces the water content of the peroxide at the bottom of the tower, thereby shortening the residence time of the peroxide and reducing energy consumption.

[0005] In a first aspect, the present invention provides a system for preparing anhydrous peroxyacids with a C3 content of above, comprising a reactive distillation bulkhead tower, the reactive distillation bulkhead tower comprising a reaction separation zone, a water zone, a tower top zone, and a tower bottom zone, wherein 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 several 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 provided 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 provided 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 delivering the solvent to 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 region is sequentially connected to the condenser and the phase separator via connecting pipes.

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

[0010] Preferably, the number of trays provided 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 structured packing. Further preferably, the structured packing is perforated plate corrugated packing, plate mesh corrugated packing, perforated plate corrugated packing, wire mesh corrugated packing, or annular corrugated packing. Even more preferably, the height of the structured packing is 3-5 meters.

[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 connecting pipes.

[0013] A second aspect of the present invention provides a method for preparing anhydrous peroxyacids with a C3 or higher content. The method is implemented in the above-mentioned system, comprising: transporting an organic acid with a C3 or higher content, hydrogen peroxide, and a catalyst to the reaction separation zone through a raw material inlet for reaction; separating the reaction product through the NaA molecular sieve membrane assembly; the separated anhydrous peroxyacid solution enters the bottom zone of the tower through the gas phase distributor; the separated water enters the water-carrying 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 temperature of the azeotropic mixture is 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 of C3 or higher described in the present invention, by replacing the partition between the reaction separation zone and the water-carrying zone in the reactive distillation bulkhead tower with a NaA molecular sieve membrane assembly, the excellent water permeation and dehydration performance of the NaA molecular sieve membrane assembly is utilized to directly separate water during the reaction process, thereby timely removing the water produced by the reaction and the water introduced by hydrogen peroxide from the system, reducing backmixing between the reaction raw materials, and thereby accelerating the reaction rate. At the same time, the bottom of the water-carrying zone is a closed structure, which prevents water in the water-carrying zone from re-entering the peroxide, thereby reducing the water content of the peroxide at the bottom of the tower, thereby shortening the residence time of the peroxide and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of a system for preparing anhydrous peroxyacids of C3 or higher 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 pipe; 10. Second connecting pipe; 11. Reboiler; 12. Phase separator; 13. Water extraction pipe; 14. Condenser; 15. Reaction distillation tray; 16. Anhydrous peracid receiving tank; 17. Reaction separation zone; 18. Water zone; 19. Tower top zone; 20. Tower bottom zone. DETAILED DESCRIPTION

[0027] The following describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0028] The endpoints of the ranges and any values ​​disclosed herein 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 endpoints of each range, the endpoints of each range and 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 to be specifically disclosed herein.

[0029] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate relative importance or implicitly specify the quantity of the technical features indicated. Therefore, unless otherwise specified, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features; "plurality" means two or more. The term "comprising" and any variations thereof are intended to be non-exclusive inclusion, and one or more other features, integers, steps, operations, units, components, and / or combinations thereof may be present or added.

[0030] In addition, terms such as "upper", "lower", "inside", and "outside" indicating orientation or positional relationships are described based on the orientation or relative positional relationships shown in the accompanying drawings. They are only simplified descriptions for the convenience of describing this 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. Therefore, they should not be understood as limitations on this application.

[0031] In addition, unless otherwise expressly specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0032] The first aspect of 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 top zone 19 and a bottom zone 20. The reaction separation zone 17 and the water zone 18 are arranged between the top zone 19 and the bottom zone 20. The reaction separation zone 17 has a raw material inlet, and the water zone 18 has several solvent inlets. 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 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 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.

[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 upper middle portion of the reactive 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 mixing feed pipe 1, which can more conveniently transport the organic acid, hydrogen peroxide, and catalyst to the reaction and separation zone 17. During the specific operation, the organic acid, hydrogen peroxide, and catalyst are transported from the raw material inlet through the mixing feed pipe 1 to the reaction and separation zone 17 for reaction. The feed temperature is 20-30°C, wherein the molar ratio of the organic acid to the hydrogen peroxide is controlled to be 1.0-1.5:1, and the content of the catalyst is 0.1-1% by weight, based on the total weight of the organic acid, hydrogen peroxide, and catalyst as 100% by weight.

[0037] In the system described herein, the organic acid and hydrogen peroxide react on the trays of the reactive distillation column under the action of a catalyst. As the reaction proceeds, the hydrogen peroxide is consumed. To prevent excessive hydrogen peroxide concentration, which could decompose the hydrogen peroxide and cause an explosion, it is necessary to replenish the reactive distillation column with hydrogen peroxide. In a specific embodiment, several hydrogen peroxide inlets are provided on the sidewalls of the reaction and separation zone 17. In a preferred embodiment, the number of hydrogen peroxide inlets is 2-5, for example, 2, 3, 4, or 5. In a more preferred embodiment, the number of hydrogen peroxide inlets is 2.

[0038] In the system of the present invention, in a specific embodiment, when there are two hydrogen peroxide inlets, the first hydrogen peroxide inlet is located in the middle of the reaction and separation zone 17, specifically, at the 10th to 15th theoretical plate of the reaction and distillation tray 15. The first hydrogen peroxide inlet is connected to a hydrogen peroxide feed pipe 2, which facilitates the introduction of hydrogen peroxide into the reaction and 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 and separation zone 17 and the concentration of peroxyacid generated after the reaction, hydrogen peroxide is added in the middle and bottom of the tower. The main purpose is to increase the conversion rate of organic acid while preventing excessive addition of hydrogen peroxide, which may cause decomposition of hydrogen peroxide and result in explosion accidents. Therefore, the feed amount of hydrogen peroxide needs to be controlled. The second hydrogen peroxide inlet is located at the lower part of the reaction and separation zone 17, specifically, can be located at the position of the 20th to 30th theoretical plate of the reaction distillation tray 15. The second hydrogen peroxide inlet is connected to another hydrogen peroxide feed pipe 2, which can more conveniently feed the hydrogen peroxide into the reaction and 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 can be purchased or prepared by methods 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, wherein sodium aluminate and alkaline silica sol are used as aluminum source and silicon source, and 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 a molar ratio, and magnetic stirring is performed at 30°C for 3 hours. During this process, alkaline silica sol is slowly added dropwise to obtain a synthetic solution for later 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. During the specific operation, in order to distill off the maximum amount of water on the left and right sides of the dividing 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 the gas phase distributor is not provided with an opening.

[0045] In the system of the present invention, in a specific embodiment, the gas phase distributor 6 can be a conventional choice in the field. During the specific operation process, in order to prevent the anhydrous peracid solution produced in the reaction and 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. Specifically, the packing layer 7 is a structured packing. The structured packing can be any conventionally selected material in the art. In a preferred embodiment, 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 an annular corrugated packing. In a further embodiment, the height of the structured packing is 3-5 meters.

[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 together and enter the water zone 18. In order to transport the water entering the water zone 18 to the top zone 19 and discharge it out of the system, while preventing the temperature of the reactive distillation bulkhead tower from being too high, thereby causing the decomposition of hydrogen peroxide and reducing the peroxyacid 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, during a specific operation, the operating pressure of the main tower of the reactive distillation bulkhead tower is set to 5-20 kPa, preferably 10-15 kPa. The organic acid with C3 or higher, hydrogen peroxide, and the catalyst are transported to the reactive separation zone 17 through the mixing feed pipe 1. The organic acid and hydrogen peroxide react on the trays of the reactive distillation tower under the action of the catalyst. The hydrogen peroxide is consumed during the reaction, so it is necessary to replenish the hydrogen peroxide in a timely manner. The hydrogen peroxide feed pipe 2 is used to replenish the reactive separation zone 17 in a timely manner. During this process, the peroxyacid product generated by the reaction enters the tower bottom zone 20 through the gas phase distributor 6, while 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 with excellent water-based osmotic dehydration performance, and mix 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. 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 includes a condenser 14 and a phase separator 12, and the top region 19 is sequentially connected to the condenser 14 and the phase separator 12 via connecting pipes. During the specific operation, the azeotrope extracted from the top region 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 aqueous 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 from 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 includes 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 via connecting pipes. During specific operation, the peroxyacid product in the tower bottom zone 20 is extracted as liquid through the reboiler 11 with a reboil ratio of 3-5:1, and is stored in the anhydrous peroxyacid receiver 16, specifically at a storage temperature of 0°C.

[0055] In the system of the present invention, in a specific embodiment, in order to obtain anhydrous peroxyacids with a C3 or higher content and to heat the organic acid with a C3 or higher content at the bottom of the tower to enter the left side of the baffle tower, thereby maintaining 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 via 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 reactive distillation bulkhead tower, the reactive distillation bulkhead tower including 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 including 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 the 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 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, 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 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 reactive distillation bulkhead tower, the reactive distillation bulkhead tower including 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 transporting 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 reactive distillation bulkhead tower, the reactive distillation bulkhead tower including 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 both connected to the tower top zone 19, and a liquid phase distributor 4 is provided at the connection point, 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 transporting 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 transporting 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 reactive distillation bulkhead tower, the reactive distillation bulkhead tower including 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 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 are 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 transporting the solvent to the water zone 18. Several 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 transporting the solvent output from the phase separator 12 to the water zone 18. The number of tower 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 reactive distillation bulkhead tower, the reactive distillation bulkhead tower including 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 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 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 tower plates provided in the reaction separation zone 17 is 25-40; a packing layer 7 is provided 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 punctured 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 including 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 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, and is used to transport the solvent output by the phase separator 12 to the water zone 18; the number of plates provided in the reaction separation zone 17 is 25-40; a packing layer 7 is provided 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 an annular corrugated packing, and the height of the structured packing is 3-5m; the system further comprises a reboiler 11 and an anhydrous peroxy acid receiving tank 16, and the bottom zone 20 is connected to the reboiler 11 and the anhydrous peroxy acid receiving tank 16 in sequence through a connecting pipe.

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

[0074] The following examples further illustrate the system and method for preparing anhydrous peroxyacids of C3 or higher according to the present invention. The examples are implemented based on the technical solutions of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection 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 reactive distillation bulkhead tower, a reboiler 11, a phase separator 12 and a condenser 14, wherein the reactive 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, and 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 plates 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 plate in the reaction separation zone 17. The raw material inlet is connected to the mixed feed pipe 1 for transporting 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, the first hydrogen peroxide inlet is located at the 10th theoretical plate in the reaction separation zone 17, and the first hydrogen peroxide inlet is located at the 10th theoretical plate 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 and 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 provided 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 for transporting the solvent to the water zone 18, and the second solvent inlet is located at the At the lower part of the packing layer 7, the second solvent inlet is connected to another solvent feed pipe 8 for transporting 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 from 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, which is connected to the reboiler 11; the phase separator 12 has a water outlet, which 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 4.6 kg of 72% propionic acid, 28% hydrogen peroxide (hydrogen peroxide concentration is 50%), and about 0.028 kg of 98% sulfuric acid is transported to the reaction separation zone 17 through the mixing feed pipe 1. The feed 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 to form peroxypropionic acid under the catalytic action of sulfuric acid. During the reaction, hydrogen peroxide (50%) with a feed 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 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 sequence, and 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 reboil ratio is 3:1, and stored at 0°C in the anhydrous peroxyacid receiver 16. 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 The NaA molecular sieve membrane was replaced with a NaA molecular sieve membrane produced by SMT. The flow rate of the obtained anhydrous peroxypropionic acid was 1.30 kg / h, the water content of the anhydrous peroxypropionic acid was 3000 ppm, the hydrogen peroxide conversion rate was 98%, and the anhydrous peroxypropionic acid yield was 98.03%.

[0082] Example 3

[0083] The method of Example 1 was followed, except that ZEBREX TMThe NaA molecular sieve membrane was replaced with a NaA molecular sieve membrane prepared according to the literature "Preparation of NaA Molecular Sieve Membrane and Its Application in Pyridine Dehydration." The resulting anhydrous peroxypropionic acid flow rate was 1.31 kg / h, the water content of the anhydrous peroxypropionic acid was 2500 ppm, the hydrogen peroxide conversion was 98.22%, and the anhydrous peroxypropionic acid yield was 98.26%.

[0084] Example 4

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

[0086] Example 5

[0087] The process was carried out in the same manner as in Example 1, except that the filler in structured packing layer 7 was replaced with wire mesh corrugated packing. The resulting flow rate of 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 with 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 hydrogen peroxide conversion rate was 98.6%, and the anhydrous peroxypropionic acid yield was 98.64%.

[0090] Example 7

[0091] The process was carried out in the same manner as in Example 1, except that a hydrogen peroxide inlet was provided on the sidewall of the reaction and separation zone 17, located at the 15th theoretical plate within the zone. The hydrogen peroxide inlet was connected to a hydrogen peroxide feed pipe 2, through which hydrogen peroxide (50%) at a feed rate of 0.4 kg / h and a feed temperature of 40°C was introduced into the reaction and separation zone 17. The resulting anhydrous peroxypropionic acid had a flow rate of 1.296 kg / h, a water content of 3200 ppm, a hydrogen peroxide conversion of 97.92%, and an anhydrous peroxypropionic acid yield of 99.96%.

[0092] Example 8

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

[0094] Example 9

[0095] The process was carried out in the same manner as in Example 1, except that a raw material mixture containing 4.6 kg of 69% propionic acid, 31% hydrogen peroxide (hydrogen peroxide concentration of 50%), and approximately 0.037 kg of 98% sulfuric acid was delivered to the reaction and separation zone 17 via the mixing feed pipe 1. The flow rate of the obtained anhydrous peroxypropionic acid was 1.292 kg / h, the water content of the anhydrous peroxypropionic acid was 2000 ppm, the hydrogen peroxide conversion was 97.62%, and the yield of anhydrous peroxypropionic acid was 97.66%.

[0096] Example 10

[0097] The process was carried out in the same manner as in Example 1, except that a raw material mixture containing 4.6 kg of 77% propionic acid, 23% hydrogen peroxide (hydrogen peroxide concentration of 50%), and approximately 0.048 kg of 98% sulfuric acid was delivered to the reaction and separation zone 17 via the mixing feed pipe 1. The flow rate of the obtained anhydrous peroxypropionic acid was 1.82 kg / h, the water content of the anhydrous peroxypropionic acid was 3000 ppm, the hydrogen peroxide conversion rate was 98.55%, and the yield of anhydrous peroxypropionic acid was 95.58%.

[0098] Example 11

[0099] The process was carried out in the same manner as in Example 1, except that a raw material mixture containing 4.6 kg of 76% butyric acid, 24% hydrogen peroxide (hydrogen peroxide concentration of 50%), and approximately 0.028 kg of 98% nitric acid was delivered to the reaction and separation zone 17 via the mixing feed pipe 1. The resulting anhydrous peroxybutyric acid had a flow rate of 1.5 kg / h, a water content of 2800 ppm, a hydrogen peroxide conversion rate of 98.07%, and an anhydrous peroxybutyric acid yield of 98.04%.

[0100] Comparative Example 1

[0101] The process was carried out in the same manner as in Example 1, except that the NaA molecular sieve membrane assembly 5 was replaced with a zirconia ceramic separation membrane. The resulting anhydrous peroxyacid had a flow rate of 0.8 kg / h, a water content of 2% for the anhydrous peroxypropionic acid, a hydrogen peroxide conversion of 60.44%, and a yield of 60.47% for the anhydrous peroxypropionic acid.

[0102] Comparative Example 2

[0103] The process was carried out in the same manner as in Example 1, except that the bottom of the water zone 18 had an opening. The flow rate of the obtained anhydrous peroxyacid was 1.0 kg / h, the water content of the anhydrous peroxyacid was 1%, the hydrogen peroxide conversion rate was 75.55%, and the yield of anhydrous peroxypropionic acid was 75.75%.

[0104] Comparative Example 3

[0105] The process was carried out in the same manner as in Example 1, except that no gas distributor was installed at the junction between the bottom of the reaction and separation zone and the tower bottom zone. The resulting anhydrous peroxyacid had a flow rate of 0.9 kg / h, a water content of 1.5%, a hydrogen peroxide conversion of 68%, and a peroxypropionic acid yield of 68.02%.

[0106] Comparative Example 4

[0107] The process was carried out in the same manner as in Example 1, except that no liquid phase distributor was installed at the junction between the top of the reaction and separation zone and the water zone and the tower top zone. The resulting anhydrous peroxyacid had a flow rate of 1.0 kg / h, a water content of 1%, a hydrogen peroxide conversion of 75.55%, and a peroxypropionic acid yield of 75.59%.

[0108] As can be seen from the above examples, the system for preparing anhydrous peroxyacid of the present invention can directly separate water during the reaction process, reduce back-mixing between the reaction raw materials, thereby accelerating the reaction rate and preventing decomposition and explosion of the peroxide. At the same time, the water content of the peroxide at the bottom of the tower can be reduced to 3500 ppm, thereby shortening the residence time of the peroxide and reducing energy consumption. The system can also achieve a hydrogen peroxide conversion rate of over 97% and an anhydrous peroxyacid yield of over 95%.

[0109] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection 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 dividing wall tower, wherein the reaction distillation dividing wall 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) The reaction separation zone (17) is 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; the bottom of the water zone (18) is a closed structure (3); and a plurality of hydrogen peroxide inlets are provided on the side wall of the reaction separation zone (17).

2. The system according to claim 1, wherein: The number of the solvent inlets is 2-5.

3. The system according to claim 1, wherein: The solvent inlet is connected to the solvent feed pipe (8) and is used to transport the solvent into the water zone (18).

4. The system according to any one of claims 1 to 3, characterized in that: The number of the hydrogen peroxide inlets is 2-5.

5. 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 region (19) is sequentially connected to the condenser (14) and the phase separator (12) via connecting pipes.

6. The system according to claim 5, 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 zone (18).

7. The system according to any one of claims 1 to 3, characterized in that: The number of trays provided in the reaction and separation zone (17) is 25-40.

8. The system according to any one of claims 1 to 3, characterized in that: A packing layer (7) is provided in the water zone (18).

9. The system according to claim 8, characterized in that The packing layer (7) is a structured packing.

10. The system according to claim 9, characterized in that 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 an annular corrugated packing.

11. The system according to claim 9 or 10, characterized in that The height of the structured packing is 3-5m.

12. The system according to any one of claims 1 to 3, characterized in that: 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 connecting pipes.

13. A method for preparing anhydrous peroxyacids having a C3 or higher content, the method being implemented in the system according to any one of claims 1 to 12, characterized in that: The method comprises: transporting an organic acid with a C3 content of above, hydrogen peroxide and a catalyst to the reaction separation zone (17) through a raw material inlet for reaction; separating the reaction product through the NaA molecular sieve membrane assembly (5); the separated anhydrous peroxy acid solution entering the tower bottom zone (20) through the gas phase distributor (6); the separated water entering the water zone (18) and forming an azeotropic mixture with the solvent injected through the solvent inlet; and the azeotropic mixture entering the tower top zone (19) through the liquid phase distributor (4).

14. The method according to claim 13, wherein: The molar ratio of the organic acid to the hydrogen peroxide is 1.0-1.5:

1.

15. The method according to claim 13 or 14, characterized in that The concentration of the hydrogen peroxide solution is 10-90% by weight.

16. The method according to claim 13 or 14, characterized in that The organic acid is propionic acid or butyric acid.

17. The method according to claim 13 or 14, characterized in that 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 %.

18. The method according to claim 13 or 14, characterized in that The catalyst is selected from one or more of sulfuric acid, phosphotungstic acid and boric acid.

19. The method according to claim 13 or 14, 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.

20. The method according to claim 19, characterized in that The azeotropic temperature of the azeotropic mixture is 10-30°C.

21. The method according to claim 13 or 14, characterized in that The feed temperature of the organic acid, hydrogen peroxide and catalyst is 20-30°C.

22. The method according to claim 13 or 14, characterized in that The reaction conditions include: temperature of 30-60° C. and pressure of 5-20 kPa.

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