A system and method for preparing anhydrous peroxyacids with C3 or higher using a resin bed coupled NaA membrane module.

Abstract

This invention belongs to the field of chemical synthesis technology, specifically relating to a system and method for preparing anhydrous peroxyacids with C3 or higher concentrations using a resin bed coupled with a NaA membrane module. The system includes a reactive distillation column, which, from top to bottom, comprises a top zone, a first structured packing layer, several reaction separation components, and a bottom zone. The reaction separation components include an acidic resin bed and a NaA molecular sieve membrane module located below the acidic resin bed. The first structured packing layer has an inlet for a mixture of C3 or higher organic acids and hydrogen peroxide, and the acidic resin bed has an inlet for organic solvents. Using this system to prepare anhydrous peroxyacids can effectively reduce the energy consumption of the reactive distillation column, accelerate the reaction rate, prevent the decomposition and explosion of peroxides, and effectively avoid catalyst loss in the later stages, preventing catalyst from entering the anhydrous peroxyacid product. Using the prepared anhydrous peroxyacid product to prepare caprolactone can achieve high caprolactone selectivity and yield.

Description

Technical Field

[0001] This invention relates to the field of chemical synthesis technology, specifically to a system and method for preparing anhydrous peroxy acids with C3 or higher using a resin bed coupled NaA membrane module, and more particularly to a system and method for preparing anhydrous peroxy acids with C3 or higher using a reactive distillation column with an acidic resin bed coupled NaA molecular sieve membrane module. Background Technology

[0002] Peroxyacid is a key raw material for the oxidation of cyclohexanone to caprolactone. Current methods primarily involve the reaction of hydrogen peroxide with propionic acid. However, this reaction generates water, and if the reaction temperature is not strictly controlled, the peroxide can decompose and explode. While traditional reactive distillation can improve conversion efficiency, reducing the water content of perpropionic acid to the ppm level requires more trays and a higher reflux ratio. Furthermore, the residence time of the peroxide in the column also increases, which can lead to peroxide decomposition and explosion.

[0003] CN102584775B and CN103570667B mention the use of reactive distillation to produce carboxylic acids peroxide. While this method overcomes the drawbacks of batch operation and can produce peroxy acids, the high water content requirement in the production of anhydrous peroxy acids leads to long residence times of peroxides, potentially causing decomposition and explosions. The high energy consumption in obtaining anhydrous peroxy acids also remains unresolved. CN202010904713.6, CN202010904726.3, and CN202010904683.9 propose methods such as slow heating and backpack-style reactive distillation to produce peroxy acids. While these methods address the issues of excessively long residence times or localized high temperatures leading to combustion and explosions, they do not solve the problem of high energy consumption in obtaining anhydrous peroxy acids. Furthermore, the use of soluble catalysts results in catalyst loss. Summary of the Invention

[0004] The purpose of this invention is to address the problems in existing technologies for preparing anhydrous peroxyacids, which cannot simultaneously solve the issues of long peroxide residence time leading to peroxide decomposition and explosion, low reaction rate, high energy consumption, and easy catalyst loss during the reaction process. Therefore, this invention proposes a system and method for preparing anhydrous peroxyacids with C3 or higher by coupling a resin bed with a NaA membrane module. This system, by coupling the NaA membrane module into a reactive distillation column, can reduce the number of theoretical plates in the column, effectively reducing energy consumption. It also enables timely separation of water from other substances during the reaction, reducing backmixing between reactants, thereby accelerating the reaction rate, reducing the reaction residence time, and effectively preventing peroxide decomposition and explosion. Furthermore, the reactive distillation column also includes an acidic resin bed arranged sequentially with the NaA membrane module. The acidic resin bed operates heterogeneously with the reactants and products, effectively avoiding catalyst loss in the later stages.

[0005] The first aspect of this invention proposes a system for preparing anhydrous peroxides with C3 or higher concentrations using a resin bed coupled with a NaA membrane module. The system includes a reactive distillation column, which, from top to bottom, comprises a top zone, a first structured packing layer, several reaction separation components, and a bottom zone. The reaction separation components include an acidic resin bed and a NaA molecular sieve membrane module located below the acidic resin bed. The first structured packing layer has an inlet for a mixture of C3 or higher organic acids and hydrogen peroxide, and the acidic resin bed has an inlet for organic solvents.

[0006] Preferably, the total height of the acidic resin bed is 10-30% of the height of the reactive distillation column.

[0007] Preferably, the number of reaction separation components is 2-4.

[0008] Preferably, the acidic resin bed also has a hydrogen peroxide inlet.

[0009] Preferably, the NaA molecular sieve membrane assembly has a first water outlet.

[0010] Preferably, the system further includes a condenser and a phase separator, with the top section of the tower connected sequentially to the condenser and the phase separator via connecting pipes. More preferably, the phase separator has a second outlet.

[0011] Preferably, the organic solvent inlet is connected to the phase separator, and is used to transport the organic solvent output from the phase separator to the acidic resin bed.

[0012] Preferably, the system further includes a second structured packing layer, the bottom of which is connected to the bottom region of the tower.

[0013] Preferably, the system further includes a reboiler and an anhydrous peroxy acid receiving tank, and the bottom zone of the tower is connected to the reboiler and the anhydrous peroxy acid receiving tank in sequence via connecting pipes.

[0014] A second aspect of this invention provides a method for preparing anhydrous peroxyacids with a concentration of C3 or higher using a resin bed coupled with a NaA membrane module. This method is implemented in the aforementioned system and includes: conveying an organic acid with a concentration of C3 or higher and hydrogen peroxide into a first structured packing layer, then reacting them in the acidic resin bed; separating the reaction product using the NaA molecular sieve membrane module; allowing the separated anhydrous peroxyacid solution to enter the bottom zone of the column; forming an azeotropic mixture with the separated water and an organic solvent conveyed to the acidic resin bed through the organic solvent inlet; and allowing the azeotropic mixture to enter the top zone of the column.

[0015] Preferably, the weight ratio of the organic acid with more than C3 atoms to hydrogen peroxide is 1-4:1; more preferably, the weight ratio of the organic acid with more than C3 atoms to hydrogen peroxide is 2-3:1.

[0016] Preferably, the concentration of the hydrogen peroxide is 30-70% by weight.

[0017] Preferably, the feeding conditions for the organic acid with C3 or higher and hydrogen peroxide include: a feeding temperature of 20-40℃ and a feeding flow rate of 2-5 kg / h.

[0018] Preferably, the temperature at the bottom of the tower is 60-70°C.

[0019] Preferably, the reaction conditions include a temperature of 40-80°C and a pressure of 5-20 kPa.

[0020] Preferably, the organic acid with more than three carbon atoms is propionic acid and / or butyric acid.

[0021] Preferably, the organic solvent is selected from one or more of ethyl acetate, propyl acetate, isobutyl acetate, propyl propionate, isopropyl propionate, ethyl propionate, butyl acetate, n-hexane, dioxane, and acetonitrile.

[0022] In the system for preparing anhydrous peroxyacids of C3 or higher using a resin bed coupled NaA membrane module as described in this invention, by coupling the NaA membrane module to a reactive distillation column, the number of theoretical plates in the reactive distillation column can be reduced, effectively reducing the energy consumption of the reactive distillation column. It can also enable timely separation of water from other substances during the reaction process, reducing backmixing between reaction raw materials, thereby accelerating the reaction rate and reducing the reaction residence time. To prevent the decomposition and explosion of peroxides, the reactive distillation column is also equipped with an acidic resin bed connected to the NaA membrane module. The acidic resin bed contains a catalyst that reacts with organic acids and hydrogen peroxide to generate peroxyacid. On the one hand, the acidic resin bed operates heterogeneously with the reaction raw materials and products, which can effectively avoid the loss of catalyst in the later stages. On the other hand, the catalyst in the acidic resin bed will not enter the top or bottom zone of the column with the azeotropic mixture or anhydrous peroxyacid product, which can effectively avoid the catalyst being doped into the final anhydrous peroxyacid product. Therefore, when using the obtained anhydrous peroxyacid product to oxidize cyclohexanone to prepare caprolactone, it will not cause caprolactone to undergo a condensation reaction, thereby improving the selectivity and yield of caprolactone. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a system for preparing anhydrous peroxypropionic acid using a resin bed coupled NaA membrane module according to the present invention.

[0024] Explanation of reference numerals in the attached figures

[0025] 1. Inlet for mixture of C3 and above organic acids and hydrogen peroxide; 2. NaA molecular sieve membrane module; 3. Hydrogen peroxide inlet; 4. Organic solvent inlet; 5. Condenser; 6. First structured packing layer; 7. Acidic resin bed; 8. First outlet; 9. Connecting pipes; 10. Phase separator; 11. Second outlet; 12. Top zone; 13. Second structured packing layer; 14. Bottom zone; 15. Reboiler; 16. Anhydrous peroxy acid receiving tank. Detailed Implementation

[0026] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0027] The endpoints and any values ​​of the ranges 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 endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0028] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. The term "comprising" and any variations thereof mean non-exclusive inclusion, where one or more other features, integers, steps, operations, units, components, and / or combinations thereof may be present or added.

[0029] Furthermore, terms such as "upper," "lower," "inner," and "outer" indicating orientation or positional relationships are based on the orientation or relative positional relationships shown in the accompanying drawings. They are merely 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, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0030] Furthermore, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0031] The first aspect of this invention proposes a system for preparing anhydrous peroxyacids with a C3 or higher concentration using a resin bed coupled NaA membrane module, such as... Figure 1 As shown, the system includes a reactive distillation column, which is provided from top to bottom as a top zone 12, a first structured packing layer 6, several reaction separation components, and a bottom zone 14. The reaction separation components include an acidic resin bed 7 and a NaA molecular sieve membrane component 2 located below the acidic resin bed 7. The first structured packing layer 6 has a mixture inlet 1 for organic acids with C3 or higher concentrations and hydrogen peroxide, and the acidic resin bed 7 has an organic solvent inlet 4.

[0032] In the system described in this invention, in a specific embodiment, the reactive distillation column can be a conventional choice in the art, specifically, the height of the reactive distillation column is 3-5m.

[0033] In the system described in this invention, in a specific embodiment, the first structured packing layer 6 has a mixture inlet 1 for organic acids of C3 or higher and hydrogen peroxide, which is connected to a raw material feed pipe. In the specific implementation process, the organic acids of C3 or higher and hydrogen peroxide are transported via the raw material feed pipe and then through the mixture inlet 1 into the first structured packing layer 6.

[0034] In the system described in this invention, in a specific embodiment, the filler in the first structured filler layer 6 is selected from one or more of wire mesh corrugated filler, mesh corrugated filler, and plate corrugated filler. In a preferred embodiment, the filler height of the first structured filler layer 6 is 0.5-1.0m.

[0035] In the system described in this invention, the acidic resin bed 7 and the NaA molecular sieve membrane assembly 2 are interconnected. This allows for the timely removal of water generated during the reaction of organic acid and hydrogen peroxide to form peroxy acid, which is beneficial for the reaction. At the same time, it avoids the explosion of peroxides and reduces the loss of catalyst in the later stages. In a specific embodiment, the acidic resin bed 7 is connected to the bottom of the first structured packing layer 6, and the acidic resin bed 7 is connected to the top of the NaA molecular sieve membrane assembly 2.

[0036] In the system described in this invention, in a specific embodiment, the acidic resin bed 7 comprises an acidic ion exchange resin. In a preferred embodiment, the acidic ion exchange resin is selected from one or more of Amberlyst series ion exchange resins, Amberlyst IR-120 ion exchange resin, and 732 type styrene strong acidic cation exchange resin.

[0037] In the system described in this invention, in a specific embodiment, the total height of the acidic resin bed 7 is 10-30% of the height of the reactive distillation column. In a preferred embodiment, the total height of the acidic resin bed 7 is 30-80% of the total height of the first structured packing layer and the second structured packing layer.

[0038] In the system described in this invention, to promptly remove water from the hydrogen peroxide and increase its concentration, thereby accelerating the reaction rate, the acidic resin bed 7 is provided with an organic solvent inlet 4 in a specific embodiment. In a preferred embodiment, the organic solvent inlet 4 is connected to an organic solvent feed pipe. During implementation, the organic solvent is transported via the organic solvent feed pipe and enters the acidic resin bed 7 through the organic solvent inlet 4. The organic solvent entering the acidic resin bed 7 forms an azeotropic mixture with the water therein, and then enters the top zone 12 of the column.

[0039] In the system described in this invention, in a specific embodiment, the NaA molecular sieve membrane assembly 2 includes a NaA molecular sieve membrane. The source of the NaA molecular sieve membrane is not limited herein; it can be purchased or prepared using methods in the prior art. In a preferred embodiment, the NaA molecular sieve membrane assembly is in a tubular form; specifically, the NaA molecular sieve membrane assembly has 10-20 tubes.

[0040] In the system described in this invention, in order to promptly remove the water generated from the reaction and the residual water in the hydrogen peroxide, in a specific embodiment, the NaA molecular sieve membrane module 2 has a first outlet 8. During implementation, since the permeation pressure of the NaA molecular sieve membrane module is lower than the distillation column pressure, water precipitated from the NaA molecular sieve membrane module is collected through the first outlet 8.

[0041] In the system described in this invention, in order to reduce the energy consumption of the reactive distillation column, accelerate the reaction rate, and improve product quality, the conversion rate of hydrogen peroxide is >97%, the selectivity of peroxyacid is >97%, the concentration of peroxyacid is 5-50% by weight, and the water content is less than 100 ppm. In a preferred embodiment, the number of reaction separation components is 2-4, for example, 2, 3, or 4. In a more preferred embodiment, the number of reaction separation components is 3.

[0042] In the system described in this invention, when the number of reaction separation components is 2-4, the consumed hydrogen peroxide needs to be replenished in a timely manner to accelerate the reaction rate. In a specific embodiment, the acidic resin bed 7 also has a hydrogen peroxide inlet 3. In a preferred embodiment, the hydrogen peroxide inlet 3 is connected to a hydrogen peroxide feed pipe, which facilitates the delivery of hydrogen peroxide to the acidic resin bed 7 during actual operation. In a more preferred embodiment, when the number of reaction separation components is 3, from top to bottom, the feed temperature of the hydrogen peroxide inlet 3 in the second acidic resin bed 7 is 40-50°C, preferably 45°C, and the feed temperature of the hydrogen peroxide inlet 3 in the third acidic resin bed 7 is 50-60°C, preferably 55°C. In a further preferred embodiment, the feed flow rate of the hydrogen peroxide inlet 3 in both the second and third acidic resin beds 7 is 1 / 3 of the feed flow rate of the mixture inlet 1 of the organic acid and hydrogen peroxide mixture.

[0043] In the system described in this invention, in order to recycle the azeotropic mixture formed in the acidic resin bed 7, in a specific embodiment, the system further includes a condenser 5 and a phase separator 10. The top zone 12 is connected to the condenser 5 and the phase separator 10 in sequence via connecting pipes. In the specific implementation, the azeotropic mixture is condensed in the condenser 5 in the top zone 12, and then separated into phases in the phase separator 10. The upper layer is the solvent phase, and the lower layer is the aqueous phase. Specifically, the phase separator 10 has a second outlet 11, through which the aqueous phase is discharged.

[0044] In the system described in this invention, in a preferred embodiment, the organic solvent inlet 4 is connected to the phase separator 10, and is used to transport the organic solvent output from the phase separator 10 to the acidic resin bed 7 for recycling. In specific operation, when the number of reaction separation components is 2-4, the organic solvent inlet 4 is connected to the connecting pipe 9, and is used to transport the organic solvent output from the phase separator 10 to each of the acidic resin beds 7 respectively.

[0045] In a specific embodiment of the system described in this invention, the system further includes a second structured packing layer 13, the bottom of which is connected to the tower bottom region 14. In a preferred embodiment, the packing material in the second structured packing layer 13 is selected from one or more of wire mesh corrugated packing, mesh corrugated packing, and plate corrugated packing. In a more preferred embodiment, the packing height of the second structured packing layer 13 is 0.5-1.0 m.

[0046] In the system described in this invention, in a specific embodiment, the system further includes a reboiler 15 and an anhydrous peroxy acid receiving tank 16. The bottom zone 14 is connected to the reboiler 15 and the anhydrous peroxy acid receiving tank 16 in sequence via connecting pipes. In specific operation, the peroxy acid product in the bottom zone 14 is collected as liquid by the reboiler 15, with a reboiling ratio of 3-5:1, and stored in the anhydrous peroxy acid receiving tank 16. Specifically, the storage temperature is 0°C.

[0047] In the system described in this invention, during specific operation, organic acids with a concentration of C3 or higher and hydrogen peroxide are transported via the raw material feed pipe and enter the first structured packing layer 6 through the mixture inlet 1. The organic acids with a concentration of C3 or higher and hydrogen peroxide undergo an autocatalytic reaction and dehydration separation in the first structured packing layer 6, and then enter the acidic resin bed 7. Simultaneously, organic solvent is transported via the organic solvent feed pipe and enters the acidic resin bed 7 through the organic solvent inlet 4. During the reaction, the product obtained from the reaction of the organic acids with a concentration of C3 or higher and hydrogen peroxide is transported through the... The NaA molecular sieve membrane module 2 performs separation, and the separated anhydrous peroxy acid solution continues to flow downward into the next acidic resin bed 7. Hydrogen peroxide is replenished into the acidic resin bed 7 through the hydrogen peroxide inlet 3 to continue the next round of reaction. Part of the separated water is discharged through the first outlet 8, and the other part of the separated water and the water remaining in the hydrogen peroxide form an azeotropic mixture with the organic solvent and enter the top zone 12 of the column. It is condensed in the condenser 5 and then separated in the phase separator 10. The aqueous phase is discharged from the second outlet 11, and the organic solvent enters the acidic resin bed 7 through the organic solvent inlet 4 for recycling.

[0048] According to a first embodiment of the system of the present invention, the system for preparing anhydrous peroxide with C3 or higher concentration includes a reactive distillation column. The reactive distillation column is provided from top to bottom as follows: a top zone 12, a first structured packing layer 6, a plurality of reaction separation components, and a bottom zone 14. The reaction separation components include an acidic resin bed 7 and a NaA molecular sieve membrane component 2 located below the acidic resin bed 7. The first structured packing layer 6 has a mixture inlet 1 for an organic acid with C3 or higher concentration and hydrogen peroxide, and the acidic resin bed 7 has an organic solvent inlet 4.

[0049] According to a second embodiment of the system of the present invention, the system for preparing anhydrous peroxide with C3 or higher concentrations includes a reactive distillation column. The reactive distillation column is provided from top to bottom as follows: a top zone 12, a first structured packing layer 6, a plurality of reaction separation components, and a bottom zone 14. The reaction separation components include an acidic resin bed 7 and a NaA molecular sieve membrane component 2 located below the acidic resin bed 7. The first structured packing layer 6 has a mixture inlet 1 for an organic acid with C3 or higher concentrations and hydrogen peroxide. The acidic resin bed 7 has an organic solvent inlet 4. The total height of the acidic resin bed 7 is 10-30% of the height of the reactive distillation column.

[0050] According to a third embodiment of the system of the present invention, the system for preparing anhydrous peroxide with C3 or higher concentration includes a reactive distillation column. The reactive distillation column is provided from top to bottom as follows: a top zone 12, a first structured packing layer 6, 2-4 reaction separation components, and a bottom zone 14. The reaction separation components include an acidic resin bed 7 and a NaA molecular sieve membrane component 2 located below the acidic resin bed 7. The first structured packing layer 6 has a mixture inlet 1 for a mixture of C3 or higher organic acid and hydrogen peroxide. The acidic resin bed 7 has an organic solvent inlet 4. The total height of the acidic resin bed 7 is 10-30% of the height of the reactive distillation column. The number of reaction separation components is 2-4.

[0051] According to a fourth embodiment of the system described in this invention, the system for preparing anhydrous peroxide with C3 or higher concentrations includes a reactive distillation column. The reactive distillation column is arranged from top to bottom as follows: a top zone 12, a first structured packing layer 6, 2-4 reaction separation components, and a bottom zone 14. The reaction separation components include an acidic resin bed 7 and a NaA molecular sieve membrane assembly 2 located below the acidic resin bed 7. The first structured packing layer 6 has a mixture inlet 1 for an organic acid with C3 or higher concentrations and hydrogen peroxide. The acidic resin bed 7 has an organic solvent inlet 4. The total height of the acidic resin bed 7 is 10-30% of the height of the reactive distillation column. The number of reaction separation components is 2-4. The acidic resin bed 7 also has a hydrogen peroxide inlet 3, and the NaA molecular sieve membrane assembly 2 has a first outlet 8.

[0052] According to a fifth embodiment of the system of the present invention, the system for preparing anhydrous peroxide with C3 or higher concentration includes a reactive distillation column. The reactive distillation column is arranged from top to bottom as follows: a top zone 12, a first structured packing layer 6, 2-4 reaction separation components, and a bottom zone 14. The reaction separation components include an acidic resin bed 7 and a NaA molecular sieve membrane assembly 2 located below the acidic resin bed 7. The first structured packing layer 6 has a mixture inlet 1 for an organic acid with C3 or higher concentration and hydrogen peroxide. The acidic resin bed 7 has an organic solvent inlet 4. The total height of the acidic resin bed 7 is 10-30% of the height of the reactive distillation column. The number of reaction separation components is 2-4. The acidic resin bed 7 also has a hydrogen peroxide inlet 3, and the NaA molecular sieve membrane assembly 2 has a first outlet 8. The system also includes a condenser 5 and a phase separator 10. The top zone 12 is connected to the condenser 5 and the phase separator 10 sequentially via connecting pipes.

[0053] According to a sixth embodiment of the system described in this invention, the system for preparing anhydrous peroxide with C3 or higher concentrations includes a reactive distillation column. The reactive distillation column is arranged from top to bottom as follows: a top zone 12, a first structured packing layer 6, 2-4 reaction separation components, and a bottom zone 14. The reaction separation components include an acidic resin bed 7 and a NaA molecular sieve membrane assembly 2 located below the acidic resin bed 7. The first structured packing layer 6 has a mixture inlet 1 for an organic acid with C3 or higher concentrations and hydrogen peroxide. The acidic resin bed 7 has an organic solvent inlet 4. The total height of the acidic resin bed 7 is 10-30% of the height of the reactive distillation column; the number of reaction separation components is 2-4; the acidic resin bed 7 also has a hydrogen peroxide inlet 3, and the NaA molecular sieve membrane component 2 has a first water outlet 8; the system also includes a condenser 5 and a phase separator 10, and the top zone 12 is connected to the condenser 5 and the phase separator 10 in sequence through connecting pipes; the organic solvent inlet 4 is connected to the phase separator 10 and is used to transport the organic solvent output by the phase separator 10 to the acidic resin bed 7.

[0054] According to a seventh embodiment of the system described in this invention, the system for preparing anhydrous peroxide with C3 or higher concentrations includes a reactive distillation column. The reactive distillation column is arranged from top to bottom as follows: a top zone 12, a first structured packing layer 6, 2-4 reaction separation components, and a bottom zone 14. The reaction separation components include an acidic resin bed 7 and a NaA molecular sieve membrane assembly 2 located below the acidic resin bed 7. The first structured packing layer 6 has a mixture inlet 1 for an organic acid with C3 or higher concentrations and hydrogen peroxide. The acidic resin bed 7 has an organic solvent inlet 4. The total height of the acidic resin bed 7 is [amount missing] of the height of the reactive distillation column. 10-30%; the number of reaction separation components is 2-4; the acidic resin bed 7 also has a hydrogen peroxide inlet 3, and the NaA molecular sieve membrane component 2 has a first outlet 8; the system also includes a condenser 5 and a phase separator 10, and the top zone 12 is connected to the condenser 5 and the phase separator 10 in sequence through connecting pipes; the organic solvent inlet 4 is connected to the phase separator 10 and is used to transport the organic solvent output by the phase separator 10 to the acidic resin bed 7; the system also includes a second structured packing layer 13, the bottom of which is connected to the bottom zone 14.

[0055] According to an eighth embodiment of the system of the present invention, the system for preparing anhydrous peroxide with C3 or higher concentrations includes a reactive distillation column. The reactive distillation column is arranged from top to bottom as follows: a top zone 12, a first structured packing layer 6, 2-4 reaction separation components, and a bottom zone 14. The reaction separation components include an acidic resin bed 7 and a NaA molecular sieve membrane assembly 2 located below the acidic resin bed 7. The first structured packing layer 6 has a mixture inlet 1 for an organic acid with C3 or higher concentrations and hydrogen peroxide. The acidic resin bed 7 has an organic solvent inlet 4. The total height of the acidic resin bed 7 is 10-30% of the height of the reactive distillation column. The number of reaction separation components is 2-4. The system also includes a hydrogen peroxide inlet 3, and the NaA molecular sieve membrane assembly 2 has a first outlet 8; the system also includes a condenser 5 and a phase separator 10, and the top zone 12 is connected to the condenser 5 and the phase separator 10 in sequence via connecting pipes; the organic solvent inlet 4 is connected to the phase separator 10 and is used to transport the organic solvent output by the phase separator 10 to the acidic resin bed 7; the system also includes a second structured packing layer 13, the bottom of which is connected to the bottom zone 14; the system also includes a reboiler 15 and an anhydrous peroxy acid receiving tank 16, and the bottom zone 14 is connected to the reboiler 15 and the anhydrous peroxy acid receiving tank 16 in sequence via connecting pipes.

[0056] A second aspect of the present invention provides a method for preparing anhydrous peroxyacid with a concentration of C3 or higher using a resin bed coupled NaA membrane module. This method is implemented in the aforementioned system and includes: conveying an organic acid with a concentration of C3 or higher and hydrogen peroxide through a mixture inlet 1 to a first structured packing layer 6; reacting the mixture in an acidic resin bed 7; separating the reaction product through the NaA molecular sieve membrane module 2; the separated anhydrous peroxyacid solution entering the bottom zone 14 of the column; forming an azeotropic mixture with an organic solvent conveyed to the acidic resin bed 7 through an organic solvent inlet 4; the azeotropic mixture entering the top zone 12 of the column; and discharging the remaining separated water through the first outlet 8.

[0057] In the method described in this invention, in a specific embodiment, the weight ratio of the organic acid with more than 3 carbon atoms to hydrogen peroxide is 1-4:1. In a preferred embodiment, the weight ratio of the organic acid with more than 3 carbon atoms to hydrogen peroxide is 2-3:1.

[0058] In the method described in this invention, in a specific embodiment, the concentration of hydrogen peroxide is 30-70% by weight. In a preferred embodiment, the concentration of hydrogen peroxide is 45-55% by weight.

[0059] In the method described in this invention, in a specific embodiment, the feeding conditions for the organic acid with C3 or higher and hydrogen peroxide include: a feeding temperature of 20-40°C and a feeding flow rate of 2-5 kg / h.

[0060] In the method described in this invention, in a specific embodiment, the temperature of the bottom zone 14 of the tower is 60-70°C.

[0061] In the method described in this invention, in a specific embodiment, the reaction conditions include: a temperature of 40-80°C and a pressure of 5-20 kPa.

[0062] In the method described in this invention, in a specific embodiment, the organic acid is propionic acid and / or butyric acid.

[0063] In the method described in this invention, in a specific embodiment, the organic solvent is selected from one or more of ethyl acetate, propyl acetate, isobutyl acetate, propyl propionate, isopropyl propionate, ethyl propionate, butyl acetate, n-hexane, dioxane, and acetonitrile.

[0064] The following examples further illustrate the system for preparing anhydrous peroxy acids with C3 or higher concentrations according to the present invention. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.

[0065] like Figure 1As shown, the embodiments and comparative examples were carried out in the following system for preparing anhydrous peroxyacids of C3 or higher. The system includes a reactive distillation column, a condenser 5, a phase separator 10, a reboiler 15, and an anhydrous peroxyacid receiving tank 16. The reactive distillation column has a height of 3m. From top to bottom, the column is provided with a top zone 12, a first structured packing layer 6, and three separation components. The separation components include an acidic resin bed 7, a NaA molecular sieve membrane assembly 2 located below the acidic resin bed 7, a second structured packing layer 13, and a bottom zone 14. The top zone 12 is connected to the condenser 5 and the phase separator 10 via connecting pipes. The bottom zone 14 is connected to the reboiler 15 and the anhydrous peroxyacid receiving tank 16 via connecting pipes. The packing in the first structured packing layer 6 is a wire mesh corrugated packing. The packing height is 0.5m. The packing in the second structured packing layer 13 is a wire mesh corrugated packing with a packing height of 0.5m. The first structured packing layer 6 has a mixture inlet 1 for organic acids of C3 or higher and hydrogen peroxide. The acidic resin bed 7 contains 732 strong acid styrene cation exchange resin. The total height of the acidic resin bed 7 is 0.9m. All three acidic resin beds 7 have organic solvent inlets 4. From top to bottom, the second and third acidic resin beds 7 have hydrogen peroxide inlets 3. The organic solvent inlets 4 are connected to the phase separator 10 and are used to transport the organic solvent output by the phase separator 10 to the acidic resin bed 7. The phase separator 10 has a second outlet 11. The NaA molecular sieve membrane assembly 2 has a first outlet 8 and is composed of 100 NaA molecular sieve tubes.

[0066] Example 1

[0067] Methods for preparing anhydrous peroxyacids include:

[0068] The reactive distillation column is set with a bottom temperature of 60°C, a top temperature of 25°C, and a pressure of 10 kPa. The bottom zone is heated (to allow the light components to evaporate and condense at the top). A feed mixture containing 50% propionic acid and 50% hydrogen peroxide (by mass fraction) is fed into the first structured packing layer 6 through the organic acid and hydrogen peroxide mixture inlet 1. The feed flow rate of the feed mixture is controlled at 3 kg / h, and the feed temperature is 25°C. Simultaneously, ethyl propionate is added to the phase separator 10, maintaining the ethyl propionate level with the baffle plate inside the phase separator. The ethyl propionate is then connected to the phase separator via a connecting pipe. The ester is sequentially fed from the organic solvent inlet 4 into three acidic resin beds 7. The propionic acid reacts with hydrogen peroxide in the first acidic resin bed 7, and the resulting peroxyacid solution enters the first NaA molecular sieve membrane module 2 for separation. The separated primary peroxyacid product enters the second acidic resin bed 7. A portion of the separated water forms an azeotropic mixture with ethyl propionate and enters the top zone 12 of the column, while the remaining water is discharged through the first outlet 8. Simultaneously, hydrogen peroxide at a temperature of 35°C and a flow rate of 2 kg / h is introduced into the second acidic resin bed 7 through the hydrogen peroxide inlet 3. The primary peroxyacid product reacts with hydrogen peroxide in the second acidic resin bed 7. The resulting peroxyacid solution enters the second NaA molecular sieve membrane module 2 for separation. The separated secondary peroxyacid product enters the third acidic resin bed 7. A portion of the separated water forms an azeotropic mixture with ethyl propionate and enters the top zone 12 of the column. The remaining separated water is discharged through the first outlet 8. Simultaneously, hydrogen peroxide at a temperature of 40°C and a flow rate of 1 kg / h is introduced into the third acidic resin bed 7 through the hydrogen peroxide inlet 3, where the secondary peroxyacid product reacts with the hydrogen peroxide. The peroxyacid solution generated in the reaction enters the third NaA molecular sieve membrane module 2 for separation. The resulting tertiary peroxyacid product enters the second structured packing layer 13, and then enters the bottom zone 14 at a temperature of 65°C. The reboiling ratio in the reboiler 15 is controlled at 3:1. The final peroxyacid product is collected in an anhydrous peroxyacid receiving tank 16. The azeotropic mixture is condensed sequentially in the condenser 5 and separated in the phase separator 10. The separated aqueous phase is discharged from the second outlet 11, and the separated ethyl propionate is transported to the acidic resin bed 7 through the organic solvent inlet 4 for recycling. The peroxyacid product collected in the anhydrous peroxyacid receiving tank 16 contains 41.89 wt% propionic acid, 28.92 wt% peroxypropionic acid, and 29.19 wt% ethyl propionate. Measurements show that the hydrogen peroxide conversion rate is 98.2% and the selectivity for peroxypropionic acid is 99.0%.

[0069] Application Example 1

[0070] 20g of cyclohexanone was weighed and placed in a batch reactor, and the temperature was raised to 50°C. A magnetic stirrer was started at 200 rpm, and 68.3g of the peroxyacid product obtained in Example 1 was slowly added dropwise to the cyclohexanone. The addition was completed after 0.5 hours, and the reaction was then maintained at 50°C and 0.1 MPa for 2 hours to obtain a caprolactone solution. The conversion rate of cyclohexanone was 99.5%, the selectivity of caprolactone was 98.5%, and the yield of caprolactone was 98.0%.

[0071] Example 2

[0072] The procedure was carried out as described in Example 1, except that the acidic resin bed 7 contained Amberlyst-15 type ion exchange resin. The peroxyacid product collected in the anhydrous peroxyacid receiving tank 16 contained 41 wt% propionic acid, 28 wt% peroxypropionic acid, and 31 wt% ethyl propionate. Measurements showed that the hydrogen peroxide conversion rate was 99.8%, and the selectivity for peroxypropionic acid was 98.2%.

[0073] Application Example 2

[0074] 20g of cyclohexanone was weighed and placed in a batch reactor, and the temperature was raised to 50°C. A magnetic stirrer was started at 200 rpm, and 64g of the peroxyacid product obtained in Example 2 was slowly added dropwise to the cyclohexanone. The addition was completed after 0.5 hours, and the reaction was maintained at 50°C and 0.1 MPa for 2 hours to obtain a caprolactone solution. The conversion rate of cyclohexanone was 99.5%, the selectivity of caprolactone was 99%, and the yield of caprolactone was 98.5%.

[0075] Example 3

[0076] The procedure was carried out as described in Example 1, except that the acidic resin bed 7 contained Amberlyst IR-120 ion exchange resin. The peroxyacid product collected in the anhydrous peroxyacid receiving tank 16 contained 42 wt% propionic acid, 25 wt% peroxypropionic acid, and 33 wt% ethyl propionate. Measurements showed that the hydrogen peroxide conversion rate was 99.0%, and the selectivity for peroxypropionic acid was 98.0%.

[0077] Application Example 3

[0078] 20g of cyclohexanone was weighed and placed in a batch reactor, and the temperature was raised to 50°C. A magnetic stirrer was started at 300 rpm, and 77g of the peroxyacid product obtained in Example 3 was slowly added dropwise to the cyclohexanone. The addition was completed after 0.5 hours, and the reaction was then maintained at 50°C and 0.1 MPa for 2 hours to obtain a caprolactone solution. The conversion rate of cyclohexanone was 99.2%, the selectivity of caprolactone was 99%, and the yield of caprolactone was 98.2%.

[0079] Example 4

[0080] The process was carried out as described in Example 1, except that the reactive distillation column included two reaction separation components (an acidic resin bed and a NaA molecular sieve membrane assembly located below the acidic resin bed). The peroxyacid product collected in the anhydrous peroxyacid receiving tank 16 contained 41.5 wt% propionic acid, 26 wt% peroxypropionic acid, and 32.5 wt% ethyl propionate. Measurements showed that the hydrogen peroxide conversion rate was 99.9% and the peroxypropionic acid selectivity was 98%.

[0081] Application Example 4

[0082] 20g of cyclohexanone was weighed and placed in a batch reactor, and the temperature was raised to 50°C. A magnetic stirrer was started at 300 rpm, and 74g of the peroxyacid product obtained in Example 4 was slowly added dropwise to the cyclohexanone. The addition was completed after 0.5 hours, and the reaction was maintained at 50°C and 0.1 MPa for 2 hours to obtain a caprolactone solution. The conversion rate of cyclohexanone was 99.3%, the selectivity of caprolactone was 99.0%, and the yield of caprolactone was 98.30%.

[0083] Example 5

[0084] The process was carried out as described in Example 1, except that the reactive distillation column included four reaction separation components (an acidic resin bed and a NaA molecular sieve membrane assembly located below the acidic resin bed). The peroxyacid product collected in the anhydrous peroxyacid receiving tank 16 contained 42 wt% propionic acid, 28 wt% peroxypropionic acid, and 30 wt% ethyl propionate. Measurements showed that the hydrogen peroxide conversion rate was 99.9% and the peroxypropionic acid selectivity was 98.0%.

[0085] Application Example 5

[0086] 20g of cyclohexanone was weighed and placed in a batch reactor, and the temperature was raised to 50°C. A magnetic stirrer was started at 300 rpm, and 69g of the peroxyacid product obtained in Example 5 was slowly added dropwise to the cyclohexanone. The addition was completed after 0.5 hours, and the reaction was maintained at 50°C and 0.1 MPa for 2 hours to obtain a caprolactone solution. The conversion rate of cyclohexanone was 98.9%, the selectivity of caprolactone was 99%, and the yield of caprolactone was 98%.

[0087] Example 6

[0088] The procedure was carried out as described in Example 1, except that a raw material mixture containing 75% butyric acid and 25% hydrogen peroxide by mass was fed into the first structured packing layer 6 through the mixture inlet 1. The peroxyacid product collected in the anhydrous peroxyacid receiving tank 16 contained 40 wt% butyric acid, 25 wt% peroxybutyric acid, and 35 wt% ethyl propionate. Measurements showed that the hydrogen peroxide conversion rate was 99.2% and the selectivity for peroxybutyric acid was 98%.

[0089] Application Example 6

[0090] 20g of cyclohexanone was weighed and placed in a batch reactor, and the temperature was raised to 50°C. A magnetic stirrer was started at 300 rpm, and 88g of the peroxyacid product obtained in Example 6 was slowly added dropwise to the cyclohexanone. The addition was completed after 0.5 hours, and the reaction was then maintained at 60°C and 0.1 MPa for 2 hours to obtain a caprolactone solution. The conversion rate of cyclohexanone was 99.0%, the selectivity of caprolactone was 98.0%, and the yield of caprolactone was 97.0%.

[0091] Example 7

[0092] The process was carried out as described in Example 1, except that the temperature in the reactive distillation column was set at 70°C and the pressure at 20 kPa. The peroxyacid product collected in the anhydrous peroxyacid receiving tank 16 contained 41 wt% propionic acid, 26 wt% peroxypropionic acid, and 33 wt% ethyl propionate. Measurements showed that the hydrogen peroxide conversion rate was 99.8% and the peroxypropionic acid selectivity was 97.8%.

[0093] Application Example 7

[0094] 20g of cyclohexanone was weighed and placed in a batch reactor, and the temperature was raised to 50°C. A magnetic stirrer was started at 40 rpm, and 74.2g of the peroxyacid product obtained in Example 7 was slowly added dropwise to the cyclohexanone. The addition was completed after 0.5 hours, and the reaction was then maintained at 60°C and 0.1 MPa for 2 hours to obtain a caprolactone solution. The conversion rate of cyclohexanone was 99.2%, the selectivity of caprolactone was 98.5%, and the yield of caprolactone was 99.7%.

[0095] Example 8

[0096] The procedure was carried out as described in Example 1, except that the feed flow rate of the raw material mixture was controlled at 3 kg / h and the feed temperature at 40°C. The peroxyacid product collected in the anhydrous peroxyacid receiving tank 16 contained 41 wt% propionic acid, 26 wt% peroxypropionic acid, and 33 wt% ethyl propionate. Measurements showed that the hydrogen peroxide conversion rate was 99.7% and the peroxypropionic acid selectivity was 97.9%.

[0097] Application Example 8

[0098] 20g of cyclohexanone was weighed and placed in a batch reactor, and the temperature was raised to 50°C. A magnetic stirrer was started at 300 rpm, and 74.5g of the peroxyacid product obtained in Example 8 was slowly added dropwise to the cyclohexanone. The addition was completed after 0.5 hours, and the reaction was then maintained at 60°C and 0.1 MPa for 2 hours to obtain a caprolactone solution. The conversion rate of cyclohexanone was 99.3%, the selectivity of caprolactone was 98.4%, and the yield of caprolactone was 97.7%.

[0099] Example 9

[0100] The procedure was carried out as described in Example 1, except that a raw material mixture containing 87.5% butyric acid and 12.5% ​​hydrogen peroxide by mass was fed into the first structured packing layer 6 through the mixture inlet 1. The peroxyacid product collected in the anhydrous peroxyacid receiving tank 16 contained 41.1 wt% propionic acid, 26 wt% peroxypropionic acid, and 32.9 wt% ethyl propionate. Measurements showed that the hydrogen peroxide conversion rate was 97.7% and the peroxypropionic acid selectivity was 98.2%.

[0101] Application Example 9

[0102] 20g of cyclohexanone was weighed and placed in a batch reactor, and the temperature was raised to 50°C. A magnetic stirrer was started at 300 rpm, and 74.12g of the peroxyacid product obtained in Example 9 was slowly added dropwise to the cyclohexanone. The addition was completed after 0.5 hours, and the reaction was then maintained at 50°C and 0.1 MPa for 2 hours to obtain a caprolactone solution. The conversion rate of cyclohexanone was 99.2%, the selectivity of caprolactone was 98.3%, and the yield of caprolactone was 97.5%.

[0103] Example 10

[0104] The method described in Example 1 was followed, except that the height of the reactive distillation column was 5m, and the total height of the acidic resin bed 7 was 2.5m. The peroxyacid product collected in the anhydrous peroxyacid receiving tank 16 contained 41wt% propionic acid, 26wt% peroxypropionic acid, and 33wt% ethyl propionate. Measurements showed that the hydrogen peroxide conversion rate was 97.7%, and the selectivity for peroxypropionic acid was 98.0%.

[0105] Application Example 10

[0106] 20g of cyclohexanone was weighed and placed in a batch reactor, and the temperature was raised to 50°C. A magnetic stirrer was started at 400 rpm, and 74.2g of the peroxyacid product obtained in Example 10 was slowly added dropwise to the cyclohexanone. The addition was completed after 0.5 hours, and the reaction was then maintained at 550°C and 0.1 MPa for 2 hours to obtain a caprolactone solution. The conversion rate of cyclohexanone was 99.2%, the selectivity of caprolactone was 98.5%, and the yield of caprolactone was 97.7%.

[0107] Comparative Example 1

[0108] The process is carried out in accordance with Example 1, except that the reactive distillation column does not have an acidic resin bed 7, and the first structured packing layer 6 has a mixture inlet 1 for organic acid, hydrogen peroxide, acidic catalyst, and organic solvent. In actual operation, the temperature in the reactive distillation column is set to 60°C and the pressure to 10 kPa. The bottom zone of the column is heated, and a raw material mixture containing 41% propionic acid, 17.8% hydrogen peroxide (50% concentration), 0.2% sulfuric acid (98% concentration), and 41% ethyl propionate is fed into the first structured packing layer 6 through the mixture inlet 1 and reacted. The product after the reaction is separated by a NaA molecular sieve membrane assembly 2. Part of the separated water forms an azeotropic mixture with ethyl propionate and enters the top zone 12 of the column, while the other part is discharged through the first outlet 8. The separated peroxypropionic acid product enters the bottom zone 14 of the column and is collected in an anhydrous peroxyacid receiving tank 16. The peroxyacid product collected in the anhydrous peroxyacid receiving tank 16 contains 42% propionic acid, 14.6 wt% peroxypropionic acid, and 44 wt% ethyl propionate. Measurements show that the hydrogen peroxide conversion rate is 49% and the peroxypropionic acid selectivity is 50%.

[0109] Comparative Application Example 1

[0110] 20g of cyclohexanone was weighed and placed in a batch reactor, and the temperature was raised to 50°C. A magnetic stirrer was started at 400 rpm, and 132g of the peroxyacid product obtained in Comparative Example 1 was slowly added dropwise to the cyclohexanone. The addition was completed after 0.5 hours, and the reaction was maintained at 50°C and 0.1 MPa for 2 hours to obtain a caprolactone solution. The conversion rate of cyclohexanone was 90%, the selectivity of caprolactone was 80%, and the yield of caprolactone was 72%.

[0111] Comparative Example 2

[0112] The procedure was carried out as described in Example 1, except that the NaA molecular sieve membrane assembly 2 in the reactive distillation column was replaced with a β-type molecular sieve membrane. The peroxyacid product collected in the anhydrous peroxyacid receiving tank 16 contained 41 wt% propionic acid, 14 wt% peroxypropionic acid, 43 wt% ethyl propionate, and 2 wt% water. Measurements showed that the hydrogen peroxide conversion rate was 80%, and the selectivity for peroxypropionic acid was 90%.

[0113] Comparative Application Example 2

[0114] 20g of cyclohexanone was weighed and placed in a batch reactor, and the temperature was raised to 50°C. A magnetic stirrer was started at 300 rpm, and 133g of the peroxyacid product obtained in Comparative Example 2 was slowly added dropwise to the cyclohexanone. The addition was completed after 0.5 hours, and the reaction was maintained at 50°C and 0.1 MPa for 2 hours to obtain a caprolactone solution. The conversion rate of cyclohexanone was 90%, the selectivity of caprolactone was 85%, and the yield of caprolactone was 76.5%.

[0115] Comparative Example 3

[0116] The procedure was carried out as described in Example 1, except that the NaA molecular sieve membrane assembly 2 in the reactive distillation column was replaced with a ZSM-5 molecular sieve membrane. The peroxyacid product collected in the anhydrous peroxyacid receiving tank 16 contained 39 wt% propionic acid, 18.1 wt% peroxypropionic acid, 40.9 wt% ethyl propionate, and 2 wt% water. Measurements showed that the hydrogen peroxide conversion rate was 85%, and the peroxypropionic acid selectivity was 91%.

[0117] Comparative Application Example 3

[0118] 20g of cyclohexanone was weighed and placed in a batch reactor, and the temperature was raised to 50°C. A magnetic stirrer was started at 300 rpm, and 106.5g of the peroxyacid product obtained in Comparative Example 3 was slowly added dropwise to the cyclohexanone. The addition was completed after 0.5 hours, and the reaction was maintained at 50°C and 0.1 MPa for 2 hours to obtain a caprolactone solution. The conversion rate of cyclohexanone was 89%, the selectivity of caprolactone was 90%, and the yield of caprolactone was 80.1%.

[0119] Comparative Example 4

[0120] The method described in Example 1 is followed, except that the acidic resin bed 7 and the NaA molecular sieve membrane assembly 2 are not spaced apart. Specifically, three acidic resin beds 7 and three NaA molecular sieve membrane assemblies 2 are connected sequentially. From top to bottom, the top of the first acidic resin bed 7 is connected to the first structured packing layer 6, and the bottom of the third acidic resin bed 7 is connected to the first NaA molecular sieve membrane assembly 2. The peroxyacid product collected in the anhydrous peroxyacid receiving tank 16 contains 41.2 wt% propionic acid, 15 wt% peroxypropionic acid, 41.8 wt% ethyl propionate, and 2 wt% water. Measurements show that the hydrogen peroxide conversion rate is 49.4% and the peroxypropionic acid selectivity is 50%.

[0121] Comparative Application Example 4

[0122] 20g of cyclohexanone was weighed and placed in a batch reactor, and the temperature was raised to 50°C. A magnetic stirrer was started at 300 rpm, and 128.5g of the peroxyacid product obtained in Comparative Example 4 was slowly added dropwise to the cyclohexanone. The addition was completed after 0.5 hours, and the reaction was maintained at 50°C and 0.1 MPa for 2 hours to obtain a caprolactone solution. The conversion rate of cyclohexanone was 95%, the selectivity of caprolactone was 80%, and the yield of caprolactone was 76%.

[0123] The system described in this invention can effectively reduce the energy consumption of the reactive distillation column, accelerate the reaction rate, prevent the decomposition and explosion of peroxides, and effectively avoid the loss of catalyst in the later stage. When the obtained anhydrous peroxy acid is used to oxidize cyclohexanone to prepare caprolactone, it will not cause caprolactone to undergo a condensation reaction, thereby improving the selectivity and yield of caprolactone. The selectivity of caprolactone is >98%, and the yield is >97%.

[0124] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A system for preparing anhydrous peroxyacids with C3 or higher using a resin bed coupled NaA membrane module, characterized in that, The system includes a reactive distillation column, which is provided from top to bottom as a top zone (12), a first structured packing layer (6), several reaction separation components and a bottom zone (14). The reaction separation components include an acidic resin bed (7) and a NaA molecular sieve membrane assembly (2) located below the acidic resin bed (7). The first structured packing layer (6) has a mixture inlet (1) for organic acids of C3 or above and hydrogen peroxide, and the acidic resin bed (7) has an organic solvent inlet (4).

2. The system according to claim 1, characterized in that, The total height of the acidic resin bed (7) is 10-30% of the height of the reactive distillation column.

3. The system according to claim 1 or 2, characterized in that, The number of reaction separation components is 2-4.

4. The system according to claim 1, characterized in that, The acidic resin bed (7) also has a hydrogen peroxide inlet (3).

5. The system according to claim 1, characterized in that, The NaA molecular sieve membrane assembly (2) has a first outlet (8).

6. The system according to claim 1, characterized in that, The system also includes a condenser (5) and a phase separator (10), and the top section (12) is connected to the condenser (5) and the phase separator (10) in sequence via connecting pipes.

7. The system according to claim 6, characterized in that, The phase separator (10) has a second outlet (11).

8. The system according to claim 6, characterized in that, The organic solvent inlet (4) is connected to the phase separator (10) and is used to transport the organic solvent output by the phase separator (10) to the acidic resin bed (7).

9. The system according to claim 1, characterized in that, The system also includes a second structured packing layer (13), the bottom of which is connected to the bottom zone (14) of the tower.

10. The system according to claim 1, characterized in that, The system also includes a reboiler (15) and an anhydrous peroxy acid receiving tank (16), and the bottom zone (14) is connected to the reboiler (15) and the anhydrous peroxy acid receiving tank (16) in sequence via connecting pipes.

11. A method for preparing anhydrous peroxyacids with C3 or higher using a resin bed coupled NaA membrane module, characterized in that, The method is implemented in any one of the systems described in claims 1-10, characterized in that the method comprises: conveying an organic acid of C3 or above and hydrogen peroxide to the first structured packing layer (6), and then reacting it in the acidic resin bed (7), separating the product obtained by the reaction through the NaA molecular sieve membrane assembly (2), and the separated anhydrous peroxy acid solution entering the bottom zone (14) of the column, and forming an azeotropic mixture with the organic solvent conveyed to the acidic resin bed (7) through the organic solvent inlet (4), and the azeotropic mixture entering the top zone (12) of the column.

12. The method according to claim 11, characterized in that, The weight ratio of the organic acid with C3 or higher to hydrogen peroxide is 1-4:

1.

13. The method according to claim 12, characterized in that, The weight ratio of the organic acid with C3 or higher to hydrogen peroxide is 2-3:

1.

14. The method according to claim 11 or 12, characterized in that, The concentration of the hydrogen peroxide is 30-70% by weight.

15. The method according to claim 11 or 12, characterized in that, The feeding conditions for the organic acids with C3 or higher and hydrogen peroxide include: a feed temperature of 20-40℃ and a feed flow rate of 2-5 kg / h.

16. The method according to claim 11 or 12, characterized in that, The temperature of the bottom zone (14) of the tower is 60-70℃.

17. The method according to claim 11, characterized in that, The reaction conditions include a temperature of 40-80℃ and a pressure of 5-20 kPa.

18. The method according to claim 11, characterized in that, The organic acids with C3 or higher are propionic acid and / or butyric acid.

19. The method according to claim 11, characterized in that, The organic solvent is selected from one or more of ethyl acetate, propyl acetate, isobutyl acetate, propyl propionate, isopropyl propionate, ethyl propionate, butyl acetate, n-hexane, dioxane, and acetonitrile.

Images