Process and apparatus for the continuous synthesis of cyclic peroxides

Abstract

A cyclic peroxide continuous synthesis method and device belong to the technical field of organic synthesis. The method pumps 2-butanone and hydrogen peroxide into a rotating disc reactor, uses a temperature-sensitive core-shell solid acid catalyst loaded on the disc surface to dynamically adjust the acid density under the radial temperature gradient, introduces ozone-containing gas to strengthen the micro-interface mass transfer, cooperates to initiate the free radical reaction, filters through the ceramic membrane, falls film evaporates and extracts the product. The invention solves the problems of low mass transfer efficiency, temperature-sensitive catalyst deactivation and continuous plugging in traditional process, and realizes safe, efficient and low-cost continuous production.

Description

Technical Field

[0001] A method and apparatus for the continuous synthesis of cyclic peroxides, belonging to the field of organic synthesis technology. Background Technology

[0002] Cyclic peroxides, particularly 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane (TEMTP), are highly reactive functional compounds widely used in polymer crosslinking agents, pharmaceutical intermediates, and energetic materials. Traditionally, the synthesis of these cyclic peroxides relies on the cyclization reaction of organic ketones with hydrogen peroxide under acidic catalytic conditions. However, due to the presence of multiple unstable peroxide bonds in the molecule, this reaction faces technical challenges such as poor thermal stability, frequent side reactions, and stringent reaction conditions. Especially when synthesized in traditional batch reactors (such as stirred tank reactors), the low heat and mass transfer efficiency easily leads to localized overheating, making it difficult to achieve a selectivity of over 80% for the target product and posing significant safety hazards (such as the risk of explosion due to heat accumulation). Furthermore, traditional processes have extremely stringent requirements for the moisture content of the raw materials (typically <5 ppm), further increasing the energy consumption and operational complexity of the initial dehydration process.

[0003] To address the aforementioned issues related to catalysis and reaction conditions, researchers in this field have focused on developing novel, highly efficient catalysts in recent years. For example, Chinese invention patent CN120346844B discloses a "solid acid catalyst for synthesizing cyclic peroxides and its application." This technology successfully prepares a functionalized solid acid catalyst with a core-shell structure by constructing a phosphorylated titanium dioxide interlayer and a nitrogen-doped sulfonated carbon shell on the surface of an aluminosilicate molecular sieve, and loading noble metal nanoparticles at the interface. Particularly noteworthy is that the catalyst's shell is grafted with a temperature-sensitive polymer network, allowing it to expose sulfonic acid groups at low temperatures for efficient activation of hydrogen peroxide, while shrinking at high temperatures to reduce acid density, thus effectively avoiding side reactions such as over-oxidation. Simultaneously, its hydrophobic shell design significantly enhances the catalyst's resistance to water poisoning. The emergence of this catalyst represents a major breakthrough in the selectivity and stability bottlenecks of traditional homogeneous and heterogeneous catalysts from a materials science perspective.

[0004] Although the catalysts of this prior art have demonstrated excellent catalytic activity and selectivity in small-scale laboratory tests, significant engineering challenges remain when applying them to industrial continuous production, especially in traditional fixed-bed or batch reactors. First, mass transfer and diffusion limitations mask the intrinsic activity of the catalyst. This catalyst possesses a complex core-shell structure, and its catalytic activity depends on the diffusion of organic ketones and hydrogen peroxide into the mesoporous channels of the outer shell and their contact with the gradient acid sites within. In traditional fixed-bed reactors, mass transfer between the liquid and solid phases relies primarily on slow molecular diffusion, making it difficult for reactants to quickly reach the active sites and for products to escape rapidly. This not only significantly reduces the actual utilization rate of the catalyst but also unnecessarily prolongs the reaction time.

[0005] Secondly, the heat transfer limitations of traditional reactors cannot match the temperature-sensitive characteristics of the catalyst. One of the core advantages of this catalyst is its specific low-temperature response range (sulfonic acid groups are exposed at <40℃, and the acid density is highest). However, in traditional fixed-bed or batch reactors, it is difficult to accurately establish and maintain such a precise local low-temperature environment on a timescale of milliseconds to seconds. At the same time, it is also difficult to achieve instantaneous removal of reaction heat, which greatly reduces the temperature-sensitive "smart switch" effect of the catalyst in practical engineering applications.

[0006] Finally, there is the issue of catalyst wear and clogging in continuous flow systems. In continuous production, the powdered or micro-particle form of the catalyst not only easily causes high pressure drops in the reactor, but also easily leads to collisions and friction between particles or between particles and the reactor wall under fluid scouring, resulting in damage to the fragile core-shell structure. This not only contaminates the product but also shortens the catalyst's lifespan.

[0007] Therefore, there is an urgent need in this field for a continuous flow synthesis process and supporting equipment that can perfectly couple "intelligent responsive solid acid catalysts" with "process enhanced transfer technology" in order to fully leverage the advantages of the catalyst's microstructure while overcoming the engineering bottlenecks of macroscopic mass and heat transfer, and to achieve safe, efficient, and low-cost continuous industrial production of cyclic peroxides. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method and apparatus for continuous synthesis of cyclic peroxides that achieves efficient, safe and low-cost industrial production.

[0009] The technical solution adopted by this invention to solve its technical problem is: a continuous synthesis method for cyclic peroxides based on a rotating disk reactor, characterized by comprising the following steps: (1) Organic ketones and hydrogen peroxide are used as reaction raw materials and pumped into the central feed zone of a rotary disk reactor; (2) The rotating disk reactor is loaded with a solid acid catalyst on its disk surface. The solid acid catalyst is a core-shell structured solid acid material with temperature-sensitive response characteristics. (3) The centrifugal force generated by the high-speed rotation of the rotating disk is used to make the raw material form a flowing micron-sized liquid film on the disk surface and flow over the surface of the solid acid catalyst; (4) During the liquid film flow, ozone-containing gas is introduced into the reaction zone to enhance mass transfer and catalysis through the micro-interface, so that the organic ketone and hydrogen peroxide undergo oxidative coupling and cyclization reactions to generate cyclic peroxides; the mixture after the reaction is separated online to obtain the target product.

[0010] This invention uses the centrifugal force of a rotating disk to form a micron-sized liquid film, shortening the mass transfer path of traditional batch reactions that takes several hours to the micron level. Combined with the micro-interface enhancement containing ozone gas, the reaction rate is increased by more than 10 times. The temperature-sensitive solid acid catalyst disclosed in CN120346844B is supported to avoid homogeneous acid corrosion, realizing continuous production and efficient recycling of the catalyst. The space-time yield is increased by 3 times compared with the fixed bed.

[0011] Preferably, the rotating disk reactor is radially divided into an inner feeding zone and an outer reaction zone, and the two zones have a temperature difference. The surface temperature of the inner feeding zone is controlled at 55℃~60℃; The surface temperature of the outer reaction zone is controlled at 35℃~40℃; The solid acid catalyst is mainly supported in the outer reaction zone.

[0012] The inner high-temperature zone of 55℃~60℃ in this invention matches the temperature-sensitive shrinkage characteristics of the catalyst, reducing the acid density to avoid violent decomposition of hydrogen peroxide; the outer low-temperature zone of 35℃~40℃ triggers the catalyst to expand, exposing high-density sulfonic acid groups to enhance the cyclization reaction, precisely matching the "smart switch" characteristics of the catalyst, thereby increasing the TEMTP selectivity to over 99% and reducing by-products by 40%.

[0013] Preferably, the solid acid catalyst is configured such that the surface acid density decreases at a temperature of 55℃~60℃ and increases at a temperature of 35℃~40℃; the solid acid catalyst is loaded by mixing solid acid catalyst powder with an inorganic binder and coating it onto the disk surface, followed by low-temperature vacuum drying and curing.

[0014] The acid density of the solid acid catalyst is dynamically adjusted with temperature to avoid the risk of hydrogen peroxide boiling violently in the early stage of the reaction. Stable Si-O-Si bonds are formed after high-temperature calcination of the substrate with a silica sol-based inorganic binder, which improves the bonding strength, makes it resistant to long-term liquid film erosion, reduces the catalyst wear rate to 0.1% / kh, and extends the lifespan to more than 2000 hours.

[0015] Preferably, the low-temperature vacuum drying and curing temperature is 100℃~180℃, the vacuum degree is ≤-0.08MPa, and the drying time is 4h~8h.

[0016] Preferably, the organic ketone is 2-butanone, the cyclic peroxide is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane (TEMTP), the hydrogen peroxide has a mass concentration of 27% to 35%, and the molar ratio of the organic ketone to hydrogen peroxide is 1:0.9 to 1.2. This invention preferably uses a hydrogen peroxide concentration of 27%~35% to balance reaction activity and safety, avoiding the risk of thermal decomposition from high-concentration hydrogen peroxide (>40%). The low excess hydrogen peroxide design with a molar ratio of 1:0.9~1.2 forms a precise synergy with the strong oxidizing power of the introduced ozone-containing gas: ozone, as a high-energy free radical initiator, rapidly starts the reaction chain in the low-temperature region (35℃~40℃), compensating for the high activation energy of low-concentration hydrogen peroxide. This ensures that even with a 15% reduction in hydrogen peroxide usage, the conversion rate of 2-butanone remains stable at over 98.5%, while significantly reducing side reactions such as peroxide bond breakage caused by excess hydrogen peroxide, and improving product selectivity to 99.2%.

[0017] According to claim 1, the method for continuous synthesis of cyclic peroxides based on a rotating disk reactor is characterized in that the rotation speed of the rotating disk reactor is 150 rpm to 350 rpm, the residence time of the raw material on the disk surface is 30 s to 120 s, and the ozone concentration in the ozone-containing gas is 10 mg / L to 50 mg / L.

[0018] At this rotation speed, the liquid film thickness can be controlled between 50μm and 200μm, balancing mass transfer efficiency and catalyst contact time; the residence time is matched with the TEMTP generation kinetics to avoid excessive residence time leading to the breakage of peroxy bonds; the ozone concentration assists in the initiation of free radicals, overcoming the activation energy barrier of hydrogen peroxide in the low-temperature region, and increasing the reaction rate by more than 25%.

[0019] Specifically, the online separation step in step (4) includes: after the reaction mixture flows out from the edge of the rotating disk, it first passes through a ceramic membrane module with a pore size of 0.1μm~0.5μm for solid-liquid separation to retain catalyst debris; then it enters a falling film evaporator to remove unreacted water and hydrogen peroxide under vacuum conditions of 60℃~80℃; finally, it enters an extraction tower and is subjected to countercurrent extraction using fluorinated ether HFE-7500 to separate the oil phase product.

[0020] The 0.1μm~0.5μm ceramic membrane efficiently retains catalyst particles, resulting in a product solid content of <1ppm; vacuum devolatilization at 60℃~80℃ avoids thermal decomposition of TEMTP, resulting in a residual hydrogen peroxide recovery rate of >95%; the HFE-7500 extractant has a partition coefficient of 120 for TEMTP, which is 3 times higher than that of traditional dichloromethane, and the product purity is stable at ≥98.5%, with no solvent residue.

[0021] Preferably, it also includes an in-situ regeneration step of the solid acid catalyst: when the continuous operation reaches a preset time or the catalytic activity drops to a threshold, the flow of organic ketone is stopped, while the flow of hydrogen peroxide and ozone-containing gas is maintained. The temperature of the rotating disk is raised to 70℃~90℃ and maintained for 1h~4h. Hydrogen peroxide and ozone-containing gas are used to oxidize and remove carbon deposits and organic residues on the surface of the catalyst. Then the temperature is lowered to restore the reaction.

[0022] In-situ regeneration at 70℃~90℃ avoids catalyst disassembly and loss. Hydrogen peroxide and ozone synergistically oxidize carbon deposits, and the acid density of the catalyst recovers to over 98% of its initial value after regeneration. Compared with offline regeneration, this reduces downtime, lowers catalyst replacement costs, and avoids the loss of heavy metal nanoparticles. During the regeneration process, the disk surface temperature rises to 70℃~90℃, which is higher than the LCST of PNIPAM. However, because the regeneration time is only 1h~4h and the polymer's thermal stability is improved in a dry state, experiments show that the polymer structure did not suffer irreversible damage after 4h of treatment at this temperature, and the acid density recovery rate is ≥98%. If further protection is required, the regeneration temperature can be controlled at 70℃~80℃.

[0023] A continuous synthesis apparatus for cyclic peroxides based on a rotating disk reactor, used to implement the above-mentioned synthesis method, characterized in that it comprises: The rotating disc reactor has a jacketed disc inside, which is divided into an inner heating zone and an outer cooling zone. A gas distributor, positioned above the rotating disk, is used to introduce ozone-containing gas onto the disk surface; The raw material feeding system is used to transport organic ketones and hydrogen peroxide to the center of the rotary table; The separation and purification system is sequentially connected to a ceramic membrane filter, a falling film evaporator, and an extraction tower. The control system is used to regulate the turntable speed, temperature, feed flow rate, and gas flow rate.

[0024] The falling film evaporator is equipped with an explosion-proof diaphragm (burst pressure ≤ 0.2 MPa) and a temperature interlock control system. When the evaporation temperature exceeds the set value (85°C), heating is automatically cut off and nitrogen is introduced for protection. The inner wall of the evaporator is made of 316L stainless steel or Hastelloy C-276 to withstand the oxidation and corrosion of residual hydrogen peroxide.

[0025] The various modules of this invention work together to achieve a continuous "reaction-separation-regeneration" process, with precise temperature control of the inner ring heating and outer ring cooling jackets; and the control system adjusts parameters such as rotation speed and flow rate in real time to ensure process stability.

[0026] Preferably, the rotating disk reactor has concentric circular grooves on its disk surface, and a foam metal skeleton layer is fixed in the grooves. The solid acid catalyst is filled or coated in the foam metal skeleton layer.

[0027] Concentric grooves are used to increase the turbulence of the liquid film and extend the residence time; the foam metal skeleton provides a high specific surface area carrier, which increases the catalyst loading, and the elasticity of the skeleton can buffer the scouring force of the buffer film and reduce the mechanical wear rate of the catalyst, making it suitable for long-term continuous operation.

[0028] Preferably, the foamed metal skeleton layer is made of foamed nickel or foamed stainless steel (316L), with a porosity of 75%~85% and a pore size of 0.5mm~2.0mm. The foamed metal is fixed to the stainless steel plate by laser welding or high-temperature brazing to ensure that it will not fall off during long-term operation.

[0029] More preferably, the porosity of the foamed metal skeleton is 75% to 85%. The preferred porosity ensures sufficient specific surface area for catalyst loading, maintains the mechanical strength of the skeleton, avoids high pressure drop or deformation, ensures uniform liquid film distribution, and improves catalytic efficiency.

[0030] More preferably, the ceramic membrane filter in the separation and purification system is configured in a cross-flow filtration mode and located directly below the rotating disk reactor to receive the reaction liquid ejected from the edge of the rotating disk. The cross-flow filtration mode effectively prevents catalyst particles from accumulating on the membrane surface, effectively slows down membrane flux decay, and extends the cleaning cycle. The ceramic membrane is positioned close to the rotating disk, allowing for timely separation of the reaction liquid after ejection, preventing the product from remaining in a high-temperature environment for too long and causing decomposition, thus reducing the TEMTP thermal decomposition loss rate.

[0031] Compared with existing technologies, the advantages of this invention are as follows: By deeply coupling a temperature-sensitive core-shell solid acid catalyst with a rotating disk micro-interface enhancement technology, this invention utilizes a radial temperature gradient to precisely trigger the dynamic response of the catalyst's acid density, thus solving the problem of temperature-sensitive effect failure caused by the lag in heat and mass transfer in traditional fixed-bed systems. A synergistic initiation mechanism is formed by a low molar ratio of hydrogen peroxide and trace amounts of ozone, significantly reducing safety risks and side reactions while ensuring a 2-butanone conversion rate of over 98.5%. The foamed metal framework and online membrane separation design overcome the wear and clogging problems of solid catalysts in continuous flow, achieving a closed-loop process of reaction-separation-regeneration. This method increases space-time yield by more than 3 times, extends catalyst life to over 2000 hours, and eliminates the need for stringent raw material dehydration, truly realizing safe, efficient, and low-cost continuous industrial production of cyclic peroxides. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the process flow for the continuous synthesis method of cyclic peroxides in an embodiment of the present invention.

[0033] Figure 2 This is a schematic diagram of the longitudinal section of the rotating disk reactor in an embodiment of the present invention.

[0034] Figure 3 for Figure 2 The enlarged structural diagram of region A shows the loading state of the foam metal skeleton layer and the catalyst.

[0035] The components include: 1. Rotary disc reactor; 101. Disc surface; 1011. Inner ring heating zone; 1012. Outer ring cooling zone; 102. Jacket; 103. Concentric grooves; 104. Foam metal skeleton layer; 105. Solid acid catalyst; 106. Gas distributor; 2. Ceramic membrane filter; 3. Falling film evaporator; 4. Extraction tower; 5. Control system.

[0036] Figure 4 The infrared spectrum of TEMTP prepared in Example 1 of this invention.

[0037] Figure 4 Both the winning standard sample and the sample were at 893.4 cm. -1 An absorption peak is observed at 1175.9 cm⁻¹, which is caused by the stretching vibration of the peroxy bond. -1 The absorption peak corresponds to the CO bond vibration adjacent to the peroxide bond, indicating the connection between the peroxide bond and the alkyl chain. 1465.6 cm⁻¹ -1 With 1375.5cm -1 The absorption peak at 2870 cm⁻¹ is attributed to the bending vibration of the CH bond between the methyl and methylene groups. -1 ~2960cm -1 The absorption peak at that point is attributed to the stretching vibration of the CH bond between the methyl and ethyl groups. The product can be identified as 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane.

[0038] Figure 5 The 1H NMR spectrum of the TEMTP prepared in Example 1 of this invention.

[0039] Figure 5 The peaks at 1.88 ppm and 1.59 ppm are CH2 of methylene, 1.25 ppm and 0.96 ppm are CH3 of methyl, and 0.87 ppm and 1.38 ppm are peaks of alkane diluent.

[0040] Figure 6 The carbon NMR spectrum of TEMTP prepared in Example 1 of this invention.

[0041] Figure 6 The peak at 109.84 ppm corresponds to a carbon atom bonded to an oxygen atom. Due to the symmetrical structure, the peak pattern is split, and other carbon atoms are also affected, resulting in peak splitting. 18.27 ppm and 8.44 ppm correspond to two methyl carbons, respectively, and 27.08 ppm to a methylene carbon. The peaks at 29.86 ppm and 14.26 ppm are alkane solvents contained in the Trigonox 301 standard. Detailed Implementation

[0042] The present invention will be further described below with reference to specific embodiments, wherein Example 1 is the preferred embodiment. The process conditions for other embodiments and comparative examples not explicitly described are the same as in Example 1. The solid acid catalyst used is a core-shell structured material with thermosensitive response characteristics, prepared according to the method of Example 1 in Chinese Invention Patent CN120346844B. The catalyst's shell is grafted with a poly(N-isopropylacrylamide) thermosensitive polymer network. At 35°C to 40°C, the sulfonic acid groups are exposed, resulting in the highest acid density; at 55°C to 60°C, the polymer chains shrink, and the acid density decreases. Example 1

[0043] 2-Butanone and 30% hydrogen peroxide are stored separately in raw material tanks. The molar ratio of 2-butanone to hydrogen peroxide is set to 1:1.1. The two materials are delivered to the central feed zone of rotary disc reactor 1 by a metering pump according to the set ratio.

[0044] The rotating disk reactor 1 has a disk 101 with a diameter of 500 mm made of 316L stainless steel. Concentric grooves 103 are machined on the surface of disk 101, and a foamed metal skeleton layer 104 with a porosity of 80% is welded and fixed within these grooves. A solid acid catalyst 105 is mixed with a silica sol binder (mass ratio 1:0.3) and coated onto the foamed metal skeleton layer 104, then vacuum-dried and cured at 150℃ (vacuum degree ≤ -0.08MPa, drying time 6h). The disk 101 is temperature-controlled in zones via the partitioning of the jacket 102: the temperature of the inner heating zone 1011 is controlled at 58℃, and the temperature of the outer cooling zone 1012 is controlled at 38℃ by separately controlling the temperature of the heat transfer oil. The solid acid catalyst 105 is mainly loaded in the outer cooling zone 1012.

[0045] The rotating disk reactor 1 is started and the rotation speed is set to 220 rpm. Under centrifugal force, the raw material flows outward, forming a micron-sized liquid film approximately 80 μm thick, flowing over the surface of the solid acid catalyst 105, with a residence time of approximately 60 s. Simultaneously, ozone-containing gas with an ozone concentration of 20 mg / L is introduced into the disk surface 101 through a gas distributor 106 positioned above the rotating disk reactor 1. The gas distributor 106 is an annular porous tube structure, installed directly above the rotating disk reactor 1 at a height of 5 mm to 10 mm from the disk surface 101. The outer diameter of the annular tube matches the outer ring reaction zone of the disk surface, and the tube wall is uniformly perforated with outlet holes of 0.5 mm to 1.0 mm in diameter, with a hole spacing of 5 mm to 10 mm. The ozone-containing gas is uniformly sprayed onto the disk surface through the gas distributor 106 and sheared into micron-sized bubbles by the high-speed rotating liquid film, achieving gas-liquid micro-interface mass transfer. The ozone is sheared into microbubbles by the rotating disk, enhancing gas-liquid mass transfer and synergistically initiating a free radical reaction with hydrogen peroxide.

[0046] After the reaction mixture is ejected from the edge of the rotating disc, it first enters the ceramic membrane filter 2 located directly below. The ceramic membrane filter 2 is set to cross-flow filtration mode with a membrane pore size of 0.2 μm to trap any catalyst debris that may detach. The filtrate passing through the ceramic membrane filter 2 enters the falling film evaporator 3. The falling film evaporator 3 operates at 75°C and a vacuum of -0.095 MPa to remove unreacted water and hydrogen peroxide. The crude product after devolatilization then enters the extraction column 4. Countercurrent extraction is performed using fluoroether HFE-7500 as the extractant, with an O / A ratio of 2:1. The top of the extraction column 4 collects an oil phase rich in TEMTP, which is then further distilled to obtain a final product with a purity of 99.0%.

[0047] Throughout the process, the flow rate of the metering pump, the rotation speed and temperature of the rotary reactor 1, the flow rate of the gas distributor 106, and the operating parameters of the separation and purification system are monitored and adjusted in real time by the control system 5 to ensure stable operation of the process.

[0048] Testing showed that, using the method of this embodiment, the conversion rate of 2-butanone remained stable at 98.8%, the selectivity of TEMTP was 99.2%, and the product purity reached 99.0%. After continuous operation for 2000 hours, the activity of the solid acid catalyst 105 did not show a significant decrease, and no wear or blockage was observed.

[0049] After 1500 hours of continuous operation, a slight decrease in the conversion rate of 2-butanone was detected. At this point, the flow of 2-butanone was stopped, while the flow of hydrogen peroxide and ozone-containing gas was maintained. The temperature of the rotating disk reactor 1, disk 101, was raised to 80°C and maintained for 2 hours. Active oxygen species were used to oxidize and remove carbon deposits and residual organic matter from the surface of the solid acid catalyst 105. After regeneration, the temperature of disk 101 was lowered to 38°C, and the flow of 2-butanone was resumed. The catalytic activity was restored to 99% of its initial level. Example 2

[0050] 2-Butanone and 27% hydrogen peroxide are stored separately in raw material tanks, with a molar ratio of 1:0.9. The two materials are pumped to the central feed zone of the rotary disc reactor 1 according to the set ratio using a metering pump. The disc 101 of the rotary disc reactor 1 is a 500mm diameter 316L stainless steel disc, with concentric grooves 103 machined on its surface. A foam metal skeleton layer 104 with a porosity of 75% is welded and fixed within the grooves. A solid acid catalyst 105 is mixed with a silica sol binder and coated onto the foam metal skeleton layer 104, then vacuum-dried and cured at 150℃ (vacuum degree ≤ -0.08MPa, drying time 6h). The disc 101 is temperature-controlled in zones using the partitioning of the jacket 102: the temperature of the inner heating zone 1011 is controlled at 55℃, and the temperature of the outer cooling zone 1012 is controlled at 35℃. The solid acid catalyst 105 is mainly supported in the outer cooling zone 1012.

[0051] The rotating disk reactor 1 is started and set to a rotation speed of 150 rpm. Under centrifugal force, the raw material flows outward, forming a micron-sized liquid film approximately 200 μm thick. This film flows over the surface of the solid acid catalyst 105, with a residence time of approximately 120 s. Simultaneously, ozone-containing gas (10 mg / L) is introduced into the disk surface 101 through a gas distributor 106 located above the rotating disk reactor 1. The ozone is sheared into microbubbles by the rotating disk, enhancing gas-liquid mass transfer and synergistically initiating a free radical reaction with hydrogen peroxide. The resulting mixture is ejected from the edge of the rotating disk and first enters the ceramic membrane filter 2 located directly below. The ceramic membrane filter 2 is configured for cross-flow filtration, with a membrane pore size of 0.1 μm, used to trap any catalyst debris that may detach. The filtrate passing through the ceramic membrane filter 2 enters the falling film evaporator 3, which operates at 60°C and a vacuum of -0.09 MPa to remove unreacted water and hydrogen peroxide. The crude product after devolatilization then enters extraction column 4, where countercurrent extraction is performed using fluoroether HFE-7500 as the extractant, with an O / A ratio of 2:1. The oil phase rich in TEMTP is collected from the top of extraction column 4, and subsequent distillation yields a final product with a purity of 98.6%.

[0052] Throughout the process, the flow rate of metering pump 2, the rotation speed and temperature of rotary reactor 1, the flow rate of gas distributor 106, and the operating parameters of the separation and purification system were monitored and adjusted in real time by control system 5. Testing showed that the conversion rate of 2-butanone was 98.5%, the selectivity of TEMTP was 99.0%, and the solid acid catalyst 105 maintained good activity after 2000 hours of continuous operation. Example 3

[0053] 2-Butanone and 35% hydrogen peroxide are stored separately in raw material tanks, with a molar ratio of 1:1.2. The two materials are pumped to the central feed zone of the rotary disc reactor 1 according to the set ratio using a metering pump. The disc 101 of the rotary disc reactor 1 is a 500mm diameter 316L stainless steel disc, with concentric grooves 103 machined on its surface. A foam metal skeleton layer 104 with a porosity of 85% is welded and fixed within the grooves. A solid acid catalyst 105 is mixed with a silica sol binder and coated onto the foam metal skeleton layer 104, then vacuum-dried and cured at 150℃ (vacuum degree ≤ -0.08MPa, drying time 6h). The disc 101 is temperature-controlled in zones using the partitioning of the jacket 102: the temperature of the inner heating zone 1011 is controlled at 60℃, and the temperature of the outer cooling zone 1012 is controlled at 40℃. The solid acid catalyst 105 is mainly supported in the outer cooling zone 1012.

[0054] The rotating disk reactor 1 is started and set to a rotation speed of 350 rpm. Under centrifugal force, the raw material flows outward, forming a micron-sized liquid film approximately 50 μm thick. This film flows over the surface of the solid acid catalyst 105, with a residence time of approximately 30 seconds. Simultaneously, ozone-containing gas (50 mg / L) is introduced into the disk surface 101 through a gas distributor 106 located above the rotating disk reactor 1. The ozone is sheared into microbubbles by the rotating disk, enhancing gas-liquid mass transfer and synergistically initiating a free radical reaction with hydrogen peroxide. The resulting mixture is ejected from the edge of the rotating disk and first enters the ceramic membrane filter 2 located directly below. The ceramic membrane filter 2 is configured for cross-flow filtration, with a membrane pore size of 0.5 μm, used to trap any catalyst debris that may detach. The filtrate passing through the ceramic membrane filter 2 enters the falling film evaporator 3, which operates at 80°C and a vacuum of -0.1 MPa to remove unreacted water and hydrogen peroxide. The crude product after devolatilization then enters extraction column 4, where countercurrent extraction is performed using fluoroether HFE-7500 as the extractant, with an O / A ratio of 2:1. The oil phase rich in TEMTP is collected from the top of extraction column 4, and subsequent distillation yields a final product with a purity of 99.3%.

[0055] Throughout the process, the flow rate of metering pump 2, the rotation speed and temperature of rotary reactor 1, the flow rate of gas distributor 106, and the operating parameters of the separation and purification system were monitored and adjusted in real time by control system 5. Testing showed that the conversion rate of 2-butanone was 99.0%, the selectivity of TEMTP was 99.3%, and the activity of solid acid catalyst 105 remained good after 2000 hours of continuous operation. Example 4

[0056] 2-Butanone and 32% hydrogen peroxide are stored separately in raw material tanks, with a molar ratio of 1:1.1. The two materials are pumped to the central feed zone of the rotary disc reactor 1 according to the set ratio using a metering pump. The disc 101 of the rotary disc reactor 1 is a 500mm diameter 316L stainless steel disc, with concentric grooves 103 machined on its surface. A foam metal skeleton layer 104 with 80% porosity is welded and fixed within the grooves. A solid acid catalyst 105 is mixed with a silica sol binder and coated onto the foam metal skeleton layer 104, then vacuum-dried and cured at 150℃ (vacuum degree ≤ -0.08MPa, drying time 6h). The disc 101 is temperature-controlled in zones using the partitioning of the jacket 102: the temperature of the inner heating zone 1011 is controlled at 58℃, and the temperature of the outer cooling zone 1012 is controlled at 38℃. The solid acid catalyst 105 is mainly supported in the outer cooling zone 1012.

[0057] The rotating disk reactor 1 is started and set to a rotation speed of 280 rpm. Under centrifugal force, the raw material flows outward, forming a micron-sized liquid film approximately 100 μm thick. This film flows over the surface of the solid acid catalyst 105, with a residence time of approximately 45 s. Simultaneously, ozone-containing gas (30 mg / L) is introduced into the disk surface 101 through a gas distributor 106 located above the rotating disk reactor 1. The ozone is sheared into microbubbles by the rotating disk, enhancing gas-liquid mass transfer and synergistically initiating a free radical reaction with hydrogen peroxide. The resulting mixture is ejected from the edge of the rotating disk and first enters the ceramic membrane filter 2 located directly below. The ceramic membrane filter 2 is configured for cross-flow filtration, with a membrane pore size of 0.3 μm, used to trap any catalyst debris that may detach. The filtrate passing through the ceramic membrane filter 2 enters the falling film evaporator 3, which operates at 70°C and a vacuum of -0.095 MPa to remove unreacted water and hydrogen peroxide. The crude product after devolatilization then enters extraction column 4, where countercurrent extraction is performed using fluoroether HFE-7500 as the extractant, with an O / A ratio of 2:1. The oil phase rich in TEMTP is collected from the top of extraction column 4, and subsequent distillation yields a final product with a purity of 99.1%.

[0058] Throughout the process, the flow rate of metering pump 2, the rotation speed and temperature of rotary reactor 1, the flow rate of gas distributor 106, and the operating parameters of the separation and purification system were monitored and adjusted in real time by control system 5. Testing showed that the conversion rate of 2-butanone was 98.9%, the selectivity of TEMTP was 99.2%, and the activity of solid acid catalyst 105 remained good after 2000 hours of continuous operation. Example 5

[0059] 2-Butanone and 30% hydrogen peroxide are stored separately in raw material tanks, with a molar ratio of 1:1.1. The two materials are pumped to the central feed zone of the rotary disc reactor 1 according to the set ratio using a metering pump. The disc 101 of the rotary disc reactor 1 is a 500mm diameter 316L stainless steel disc, with concentric grooves 103 machined on its surface. A foam metal skeleton layer 104 with 80% porosity is welded and fixed within the grooves. A solid acid catalyst 105 is mixed with a silica sol binder and coated onto the foam metal skeleton layer 104, then vacuum-dried and cured at 150℃ (vacuum degree ≤ -0.08MPa, drying time 6h). The disc 101 is temperature-controlled in zones using the partitioning of the jacket 102: the temperature of the inner heating zone 1011 is controlled at 58℃, and the temperature of the outer cooling zone 1012 is controlled at 38℃. The solid acid catalyst 105 is mainly supported in the outer cooling zone 1012.

[0060] The rotating disk reactor 1 is started and set to a rotation speed of 220 rpm. Under centrifugal force, the raw material flows outward, forming a micron-sized liquid film approximately 80 μm thick. This film flows over the surface of the solid acid catalyst 105, with a residence time of approximately 60 s. Simultaneously, ozone-containing gas (20 mg / L) is introduced into the disk surface 101 through a gas distributor 106 located above the rotating disk reactor 1. The ozone is sheared into microbubbles by the rotating disk, enhancing gas-liquid mass transfer and synergistically initiating a free radical reaction with hydrogen peroxide. The resulting mixture is ejected from the edge of the rotating disk and first enters the ceramic membrane filter 2 located directly below. The ceramic membrane filter 2 is configured for cross-flow filtration, with a membrane pore size of 0.2 μm, used to trap any catalyst debris that may detach. The filtrate passing through the ceramic membrane filter 2 enters the falling film evaporator 3, which operates at 75°C and a vacuum of -0.095 MPa to remove unreacted water and hydrogen peroxide. The crude product after devolatilization then enters extraction column 4, where countercurrent extraction is performed using fluoroether HFE-7500 as the extractant, with an O / A ratio of 2:1. The oil phase rich in TEMTP is collected from the top of extraction column 4, and subsequent distillation yields a final product with a purity of 99.1%.

[0061] Throughout the process, the flow rate of metering pump 2, the rotation speed and temperature of rotary reactor 1, the flow rate of gas distributor 106, and the operating parameters of the separation and purification system were monitored and adjusted in real time by control system 5. Testing showed that the conversion rate of 2-butanone was 98.9%, the selectivity of TEMTP was 99.3%, and the activity of solid acid catalyst 105 remained good after 2000 hours of continuous operation. Example 6

[0062] 2-Butanone and 32% hydrogen peroxide are stored separately in raw material tanks, with a molar ratio of 1:1.1. The two materials are pumped to the central feed zone of the rotary disc reactor 1 according to the set ratio using a metering pump. The disc 101 of the rotary disc reactor 1 is a 500mm diameter 316L stainless steel disc, with concentric grooves 103 machined on its surface. A foam metal skeleton layer 104 with 80% porosity is welded and fixed within the grooves. A solid acid catalyst 105 is mixed with a silica sol binder and coated onto the foam metal skeleton layer 104, then vacuum-dried and cured at 150℃ (vacuum degree ≤ -0.08MPa, drying time 6h). The disc 101 is temperature-controlled in zones using the partitioning of the jacket 102: the temperature of the inner heating zone 1011 is controlled at 58℃, and the temperature of the outer cooling zone 1012 is controlled at 38℃. The solid acid catalyst 105 is mainly supported in the outer cooling zone 1012.

[0063] The rotating disk reactor 1 is started and set to a rotation speed of 220 rpm. Under centrifugal force, the raw material flows outward, forming a micron-sized liquid film approximately 80 μm thick. This film flows over the surface of the solid acid catalyst 105, with a residence time of approximately 60 s. Simultaneously, ozone-containing gas (25 mg / L) is introduced into the disk surface 101 through a gas distributor 106 located above the rotating disk reactor 1. The ozone is sheared into microbubbles by the rotating disk, enhancing gas-liquid mass transfer and synergistically initiating a free radical reaction with hydrogen peroxide. The resulting mixture is ejected from the edge of the rotating disk and first enters the ceramic membrane filter 2 located directly below. The ceramic membrane filter 2 is configured for cross-flow filtration, with a membrane pore size of 0.2 μm, used to trap any catalyst debris that may detach. The filtrate passing through the ceramic membrane filter 2 enters the falling film evaporator 3, which operates at 75°C and a vacuum of -0.095 MPa to remove unreacted water and hydrogen peroxide. The crude product after devolatilization then enters extraction column 4, where countercurrent extraction is performed using fluoroether HFE-7500 as the extractant, with an O / A ratio of 2:1. The oil phase rich in TEMTP is collected from the top of extraction column 4, and subsequent distillation yields a final product with a purity of 99.2%.

[0064] Throughout the process, the flow rate of metering pump 2, the rotation speed and temperature of rotary reactor 1, the flow rate of gas distributor 106, and the operating parameters of the separation and purification system were monitored and adjusted in real time by control system 5. Testing showed that the conversion rate of 2-butanone was 99.0%, the selectivity of TEMTP was 99.4%, and the activity of solid acid catalyst 105 remained good after 2000 hours of continuous operation. Example 7

[0065] 2-Butanone and 30% hydrogen peroxide are stored separately in raw material tanks, with a molar ratio of 1:1.1. The two materials are pumped to the central feed zone of the rotary disc reactor 1 according to the set ratio using a metering pump. The disc 101 of the rotary disc reactor 1 is a 500mm diameter 316L stainless steel disc, with concentric grooves 103 machined on its surface. A foam metal skeleton layer 104 with 80% porosity is welded and fixed within the grooves. A solid acid catalyst 105 is mixed with a silica sol binder and coated onto the foam metal skeleton layer 104, then vacuum-dried and cured at 150℃ (vacuum degree ≤ -0.08MPa, drying time 6h). The disc 101 is temperature-controlled in zones using the partitioning of the jacket 102: the temperature of the inner heating zone 1011 is controlled at 58℃, and the temperature of the outer cooling zone 1012 is controlled at 38℃. The solid acid catalyst 105 is mainly supported in the outer cooling zone 1012.

[0066] The rotating disk reactor 1 is started and set to a rotation speed of 220 rpm. Under centrifugal force, the raw material flows outward, forming a micron-sized liquid film approximately 80 μm thick. This film flows over the surface of the solid acid catalyst 105, with a residence time of approximately 60 s. Simultaneously, ozone-containing gas (20 mg / L) is introduced into the disk surface 101 through a gas distributor 106 located above the rotating disk reactor 1. The ozone is sheared into microbubbles by the rotating disk, enhancing gas-liquid mass transfer and synergistically initiating a free radical reaction with hydrogen peroxide. The resulting mixture is ejected from the edge of the rotating disk and first enters the ceramic membrane filter 2 located directly below. The ceramic membrane filter 2 is configured for cross-flow filtration, with a membrane pore size of 0.2 μm, used to trap any catalyst debris that may detach. The filtrate passing through the ceramic membrane filter 2 enters the falling film evaporator 3, which operates at 75°C and a vacuum of -0.095 MPa to remove unreacted water and hydrogen peroxide. The crude product after devolatilization then enters extraction column 4, where countercurrent extraction is performed using fluoroether HFE-7500 as the extractant, with an O / A ratio of 2:1. The oil phase rich in TEMTP is collected from the top of extraction column 4, and subsequent distillation yields a final product with a purity of 99.0%.

[0067] Throughout the process, the flow rate of metering pump 2, the rotation speed and temperature of rotary reactor 1, the flow rate of gas distributor 106, and the operating parameters of the separation and purification system were monitored and adjusted in real time by control system 5. Testing showed that the conversion rate of 2-butanone was 98.8%, the selectivity of TEMTP was 99.2%, and the activity of solid acid catalyst 105 remained good after 2000 hours of continuous operation.

[0068] Comparative Example 1 The same rotating disk reactor 1 and process parameters as in Example 5 were used: a 500mm diameter disk 101, a foamed metal skeleton layer 104 with 80% porosity supporting a solid acid catalyst 105, an inner heating zone 1011 at 58°C, an outer cooling zone 1012 at 38°C, a rotation speed of 220 rpm, and a residence time of 60 s. The raw materials were also 2-butanone and 30% hydrogen peroxide in a molar ratio of 1:1.1. The difference was that only nitrogen was introduced into the gas distributor 106 as a protective gas; ozone was not introduced, and hydrogen peroxide was the sole oxygen source. The resulting mixture entered the same separation system. Testing revealed that due to the lack of ozone as a free radical initiator, the decomposition rate of hydrogen peroxide significantly slowed down in the outer low-temperature zone (35°C–40°C), leading to impaired reaction kinetics. The 2-butanone conversion rate was only 85.4%, and the TEMTP selectivity was 90.1%. During the experiment, in order to achieve the same conversion rate, the excess ratio of hydrogen peroxide was increased to 1:1.5, which led to an increase in unreacted hydrogen peroxide residue, an increase in separation load, and a significant increase in the content of carboxylic acid byproducts with broken peroxy bonds in the product, resulting in a product purity of only 96.5%.

Claims

1. A method for continuous synthesis of cyclic peroxides, characterized in that, Includes the following steps: (1) Organic ketones and hydrogen peroxide are used as reaction raw materials and pumped into the central feed zone of a rotary disk reactor; (2) The rotating disk reactor is loaded with a solid acid catalyst on its disk surface. The solid acid catalyst is a core-shell structured solid acid material with temperature-sensitive response characteristics. (3) The centrifugal force generated by the high-speed rotation of the rotating disk is used to make the raw material form a flowing micron-sized liquid film on the disk surface and flow over the surface of the solid acid catalyst; (4) During the liquid film flow, ozone-containing gas is introduced into the reaction zone to enhance mass transfer and catalysis through the micro-interface, so that the organic ketone and hydrogen peroxide undergo oxidative coupling and cyclization reactions to generate cyclic peroxides; the mixture after the reaction is separated online to obtain the target product.

2. The method for continuous synthesis of cyclic peroxides according to claim 1, characterized in that, The rotating disk reactor is radially divided into an inner feed zone and an outer reaction zone, and the two zones have a temperature difference: The surface temperature of the inner feeding zone is controlled at 55℃~60℃; The surface temperature of the outer reaction zone is controlled at 35℃~40℃; The solid acid catalyst is supported in the outer reaction zone.

3. The method for continuous synthesis of cyclic peroxides according to claim 2, characterized in that, The solid acid catalyst is configured such that the surface acid density decreases at a temperature of 55℃~60℃ and increases at a temperature of 35℃~40℃. The solid acid catalyst is loaded by mixing solid acid catalyst powder with an inorganic binder and coating it onto the disk surface, followed by low-temperature vacuum drying and curing.

4. The method for continuous synthesis of cyclic peroxides based on a rotating disk reactor according to claim 1, characterized in that, The organic ketone is 2-butanone, and the cyclic peroxide is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane; the hydrogen peroxide has a mass concentration of 27%~35%, and the molar ratio of the organic ketone to hydrogen peroxide is 1:0.9~1.

2.

5. The method for continuous synthesis of cyclic peroxides based on a rotating disk reactor according to claim 1, characterized in that, The rotating disk reactor rotates at a speed of 150 rpm to 350 rpm, and the residence time of the raw material on the disk is 30 s to 120 s; the ozone concentration in the ozone-containing gas is 10 mg / L to 50 mg / L.

6. The method for continuous synthesis of cyclic peroxides based on a rotating disk reactor according to claim 1, characterized in that, The online separation step described in step (4) includes: After the reaction mixture flows out from the edge of the rotating disk, it first undergoes solid-liquid separation through a ceramic membrane module with a pore size of 0.1μm~0.5μm to retain catalyst debris; then it enters a falling film evaporator to remove unreacted water and hydrogen peroxide under vacuum conditions of 60℃~80℃; finally, it enters an extraction tower for countercurrent extraction using fluoroether HFE-7500 to separate the oil phase product.

7. The method for continuous synthesis of cyclic peroxides according to claim 1, characterized in that, It also includes an in-situ regeneration step for solid acid catalysts: When the continuous operation reaches the preset time or the catalytic activity drops to the threshold, stop the flow of organic ketones and continue to flow hydrogen peroxide and ozone-containing gas. The temperature of the rotating disk is raised to 70℃~90℃ and maintained for 1h~4h. Hydrogen peroxide and ozone-containing gas are used to oxidize and remove carbon deposits and organic residues on the surface of the catalyst. Then the temperature is lowered to restore the reaction.

8. A continuous synthesis apparatus for cyclic peroxides, used to implement the continuous synthesis method for cyclic peroxides according to any one of claims 1 to 7, characterized in that, include: The rotating disc reactor has a jacketed disc inside, which is divided into an inner heating zone and an outer cooling zone. A gas distributor, positioned above the rotating disk, is used to introduce ozone-containing gas onto the disk surface; The raw material feed pipe is used to transport organic ketones and hydrogen peroxide to the center of the rotary table; The separation and purification system is sequentially connected to a ceramic membrane filter, a falling film evaporator, and an extraction tower. The control system is used to regulate the turntable speed, temperature, feed flow rate, and gas flow rate.

9. A continuous synthesis apparatus for cyclic peroxides according to claim 8, characterized in that, The rotating disk reactor has concentric circular grooves on its disk surface, and a foam metal skeleton layer is fixed in the grooves. The solid acid catalyst is filled or coated in the foam metal skeleton layer.

10. A continuous synthesis apparatus for cyclic peroxides according to claim 8, characterized in that, The ceramic membrane filter in the separation and purification system is configured in cross-flow filtration mode and is located directly below the rotating disk reactor to receive the reaction liquid ejected from the edge of the rotating disk.

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