A preparation method of TEMTP

Abstract

The present invention relates to a preparation method of TEMTP, belonging to the technical field of organic cyclic peroxides. Based on an efficient preparation method using a three-stage microchannel reactor, the first-stage 2 ± 0.2 mm serpentine channel realizes high-shear mixing, the inner wall of the second-stage 1 ± 0.2 mm spiral channel is loaded with TiO2-Ag nano-photocatalyst, and supercritical CO2 is introduced into the third-stage 2 ± 0.2 mm straight channel to reduce the viscosity of the material and improve the mass transfer efficiency. The catalytic system uses the ionic liquid [BMIM][HSO4] and sulfuric acid in combination, with segmented temperature control. The post-treatment process includes electric field-assisted phase separation, which improves the product purity, selectivity and stability, and has important industrial application value.

Description

Technical Field

[0001] The present invention relates to a preparation method of TEMTP, belonging to the technical field of organic cyclic peroxides. Background Art

[0002] 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane (TEMTP) is a typical organic cyclic peroxide, which has high activity and oxidizing property and is easy to decompose. Due to the existence of peroxy bonds and high oxygen element content in its molecular structure, TEMTP can be used as a radical initiator and participate in oxidation reactions, and is widely used in the fields of organic synthesis, polymer materials, fuel additives, etc. However, there are many problems in the synthesis process of existing polyperoxyalkane compounds, such as harsh reaction conditions, low product purity, poor stability, etc. These problems not only limit its application in industry, but also increase production costs and environmental burdens. Therefore, it is of great significance to develop an efficient, mild and environmentally friendly preparation method.

[0003] The existing preparation methods of organic peroxides still have certain deficiencies in terms of reaction conditions, product purity, stability and environmental friendliness. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: to overcome the deficiencies of the prior art, provide an optimized synthesis process, reduce the harshness of reaction conditions, improve the purity and stability of the product, and at the same time reduce the environmental burden, so as to meet the requirements of industrial production for the preparation method of TEMTP, an efficient and environmentally friendly organic peroxide.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a preparation method of TEMTP, comprising the following steps: carrying out a synthesis reaction of an organic ketone and hydrogen peroxide under the catalysis of a composite sulfuric acid catalyst in a three-stage microchannel reactor, and the oil phase separated from the reaction system is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane; wherein the reaction temperature is 10°C to 35°C; the total reaction time in the three-stage microchannel is 3.5 h to 6 h; the feed molar ratio of the organic ketone to hydrogen peroxide is 0.5 to 2.5:1; the organic ketone is selected from one or more of methyl ethyl ketone and its homologues;

[0006] The three-stage microchannel reactor is: the first-stage channel is a 2 ± 0.2 mm serpentine structure for high-shear mixing; the secondary channel is a 1 ± 0.2 mm spiral structure with a TiO 2 -Ag nanophotocatalyst loaded on the inner wall; the last-stage channel is a 2 ± 0.2 mm straight channel into which supercritical CO 2 .

[0007] The present invention realizes the efficient synthesis of TEMTP through the collaborative design of a three-stage microchannel reactor (the first-stage serpentine channel achieves high-shear mixing, the second-stage helical channel is loaded with TiO 2 -Ag nanophotocatalyst to enhance selectivity, and the last-stage straight channel introduces supercritical CO 2 to strengthen mass transfer and green separation), combined with a composite sulfuric acid catalyst and low-temperature temperature control technology. This process uses organic ketone and hydrogen peroxide as raw materials, and avoids local overheating through continuous flow in the microchannel, significantly improving the product purity and stability; at the same time, using supercritical CO 2 to replace toxic solvents and photocatalysis to reduce by-products, which has both green environmental protection and economic advantages. While reducing energy consumption and safety risks, it realizes continuous production with high yield and high structural controllability, providing an efficient, safe and environmentally friendly solution for industrial applications.

[0008] The synthesis reaction route of the present invention is as follows:

[0009] .

[0010] Preferably, in the above method for preparing TEMTP, the length of the first-stage channel is 1000 ± 100 mm, and rapid and uniform mixing of raw materials is achieved through high shear force. The TiO 2 -Ag nanophotocatalyst loaded on the inner wall of the second-stage channel has a loading amount of 8 mg / cm² to 12 mg / cm², and is irradiated with ultraviolet light of 365 nm. Under the irradiation of ultraviolet light of 365 nm, the reaction activation energy is effectively reduced.

[0011] The TiO 2 -Ag nanophotocatalyst is a catalyst prepared by the impregnation-calcination method customized for the present invention. The core steps include impregnation, drying and calcination: First, disperse the TiO 2 carrier (such as Degussa P25) in a solvent, eliminate agglomeration by ultrasonic treatment, and then dropwise add silver nitrate solution according to the target loading amount (2.5 wt%). Stir for 4 to 12 hours under acidic conditions (pH ≈ 3 to 5) to make Ag + uniformly adsorbed on the surface of TiO 2 ; then remove the solvent by drying at 60°C to 80°C under normal pressure to avoid local enrichment of Ag + ; finally, place the dried sample in a muffle furnace, heat it to 300°C to 400°C at a rate of 2°C / min to 5°C / min (maintain the anatase phase below 400°C), and calcine it in air or an inert atmosphere for 2 to 4 hours to decompose AgNO 3 into silver nanoparticles and stably load them on the surface of TiO 2 to obtain. The preparation cost of this method is small, suitable for large-scale production use, and TiO 2The -Ag nanophotocatalyst can also achieve a similar catalytic effect.

[0012] Preferably, in the above preparation method of TEMTP, the supercritical CO in the final-stage channel 2 is set at a pressure of 7.4 MPa to 7.8 MPa. When the pressure of the supercritical CO in the final-stage channel 2 is set at 7.4 MPa to 7.8 MPa, by precisely regulating the CO 2 to be in the supercritical state, it not only enhances the mass transfer efficiency (using its high diffusivity and solubility to accelerate the reaction process), but also can achieve green separation by means of the selective dissolution characteristics of the supercritical fluid for the product (the product is instantaneously precipitated after depressurization and the CO 2 vaporizes, with a purity ≥ 95%), and at the same time, the temperature corresponding to this pressure range matches the reaction temperature, inhibiting the thermal decomposition of peroxides and free radical side reactions, ensuring safety; in addition, a slightly higher pressure than the critical point can reduce the equipment pressure resistance cost, and combined with the recyclability of supercritical CO 2 to reduce solvent consumption, and the residual TiO 2 -Ag photocatalyst particles in the secondary channel can also self-clean the surface through the microemulsion effect in the supercritical system, prolonging the catalytic life, and finally realizing efficient, environmentally friendly and low-cost continuous production.

[0013] Preferably, in the above preparation method of TEMTP, the inner wall surfaces of the three-stage microchannel reactor are all attached with a superhydrophobic interface formed by plasma grafting perfluorosilane to reduce material residue and lower the water consumption for single-batch cleaning.

[0014] Specifically, the treatment steps of the superhydrophobic interface formed by plasma grafting perfluorosilane are as follows:

[0015] Ultrasonically clean and dry the inner tube of the three-stage microchannel reactor with acetone and ethanol, and then introduce an O 2 / Ar mixed gas (ratio 1:1), and clean it for 10 to 15 minutes under an ultrasonic power of 80 W to 120 W to remove surface impurities and generate active hydroxyl groups. Then, atomize a 1% to 2% vol ethanol solution of perfluorosilane (such as FAS-17) and introduce it into the tube through a nitrogen carrier gas, and perform plasma grafting for 30 ± 5 minutes at a power of 100 ± 5 W and a pressure of 100 Pa to 200 Pa, so that the perfluorosilane decomposes into active free radicals and covalently bonds with the hydroxyl groups on the substrate surface to form a vertically arranged perfluorinated chain monolayer. Finally, purge the unreacted substances with nitrogen, thermally cure at 80 °C to 120 °C for 1 hour to enhance the interface stability, then rinse with ethanol and dry. The grafting density of perfluorosilane is 10 ± 2 μg / cm², and the preparation of the superhydrophobic interface is completed.

[0016] Preferably, in the above preparation method of TEMTP, the composite sulfuric acid catalyst is an ionic liquid [BMIM][HSO 4 and sulfuric acid (calculated as pure sulfuric acid, with a concentration of 50 wt% - 80 wt%) in a mass ratio of 1:2.6 - 3.3. The addition amount of the composite sulfuric acid catalyst is 1% - 5% of the mass of the organic ketone. This composite sulfuric acid catalyst is an ionic liquid - acid composite system, which can reduce the sulfuric acid consumption and the cost of waste acid treatment, better balance the reaction rate through dynamic feeding, and improve the space - time yield. The reaction selectivity is better. With multi - stage gradient temperature control to inhibit the formation of dimer by - products, the product selectivity is increased to more than 98.5%.

[0017] Specifically, the preparation steps of the composite sulfuric acid catalyst are as follows: 1 - butyl - 3 - methylimidazolium bromide ([BMIM]Br) and sodium bisulfate (NaHSO 4 ) are reacted at a molar ratio of 1:3 - 3.5 at 100 °C - 105 °C for 100 min - 150 min to obtain [BMIM][HSO 4 ] ionic liquid; the ionic liquid and sulfuric acid are mixed in proportion to obtain the composite sulfuric acid catalyst.

[0018] The preparation of this composite sulfuric acid catalyst is achieved by compounding the ionic liquid [BMIM][HSO 4 ] with sulfuric acid, which has both greenness and high efficiency: First, an ionic liquid is synthesized by mild anion exchange of [BMIM]Br and cheap NaHSO 4 The process is simple and low - cost; after compounding, the acidity of the ionic liquid synergistically forms a dynamic proton network with strong sulfuric acid, reducing the sulfuric acid consumption, while improving the catalytic efficiency and reaction selectivity; the recyclability of the ionic liquid (activity ≥ 90% after 35 cycles) and economic ratio (sulfuric acid concentration 50 wt% - 80 wt%) further strengthen the system stability (decomposition temperature ≥ 180 °C). Combined with the gradient temperature control of microchannel continuous flow, the dimer by - products are precisely inhibited, ensuring the product purity (≥ 99%), and realizing multiple optimizations of "high - efficiency catalysis - low - consumption emission reduction - process compatibility".

[0019] Preferably, in the above preparation method of TEMTP, the reaction temperature in the primary channel is 15 ± 2 °C, and the reaction time is 20 s - 40 s; the reaction temperature in the secondary channel is 22 ± 2 °C, and the reaction time is 25 min - 35 min; the reaction temperature in the final channel is 32 ± 0.5 °C, and the reaction time is 50 min - 70 min; the feed molar ratio of the organic ketone to hydrogen peroxide is 0.6 - 1.2:1.

[0020] In this reaction system, through the precise control of multi-stage temperature and time, an efficient and selective reaction process is achieved. First, the high-shear micro-mixing technology (20 - 40 seconds) quickly forms a homogeneous system, avoiding the risk of peroxy bond breakage or explosive polymerization caused by local overheating, while reducing the side reaction of ketone self-condensation under acidic conditions, reducing by-products by 12% - 18%. The secondary reaction is carried out under medium temperature (22 °C) conditions, adapting to the TiO 2 -Ag photocatalytic activity window. Under ultraviolet excitation, hydrogen peroxide is selectively activated to generate hydroxyl radicals (·OH), which precisely attack the α-H site of the ketone, inhibiting non-target oxidation paths (such as peroxyacid formation), thereby increasing the selectivity of the main reaction to over 98.5%. The final reaction is carried out at a precise high temperature (32 ± 0.5 °C), matching the critical temperature of supercritical CO 2 (31.1 °C). Under supercritical conditions, the mass transfer efficiency is enhanced, increasing the diffusion rate by 3 - 5 times, promoting the complete cyclization of intermediates, and strictly controlling the temperature (±0.5 °C fluctuation) to avoid the thermal decomposition of peroxides (decomposition rate < 0.5%).

[0021] In terms of time control, the residence time of the primary reaction is in the order of seconds (20 - 40 seconds), meeting the rapid nucleophilic addition of protonated ketone and hydrogen peroxide, avoiding the side reaction of acid-catalyzed hydrolysis caused by retention in the microchannel, and thus reducing hydrolysis products. The secondary reaction time is 25 - 35 minutes, ensuring sufficient progress of the photocatalytic oxidation and cyclization steps. At the same time, the light contact time is extended through the spiral channel to improve the photon utilization rate. The final reaction time is 50 - 70 minutes, ensuring the slow and orderly assembly of the triperoxy cyclic structure, using the solvation effect of supercritical CO 2 to stabilize the transition state and reduce the breakage of peroxy bonds caused by ring tension, ultimately ensuring the integrity of the product structure.

[0022] Preferably, in the above preparation method of TEMTP, during the oil phase separation, the reaction solution is carried out in a pulsed electric field phase separation tank, and the field strength of the pulsed electric field phase separation tank is set to 550 ± 5 V / cm. In the phase separation treatment stage, the reaction solution enters the pulsed electric field phase separation tank, and its field strength is set to about 550 V / cm. Electric field-assisted phase separation can significantly shorten the phase separation time, reducing the phase separation time from about 2 h to about 25 minutes; and reducing the water content in the oil phase, with the water content in the oil phase ≤ 0.3%.

[0023] Preferably, in the above preparation method of TEMTP, it further includes a solvent recovery step. The aqueous phase recovers residual 2-butanone through a molecular sieve adsorption tower, and the waste acid solution is neutralized with magnesium oxide to recover magnesium sulfate crystals.

[0024] The present invention combines the optimization of the catalytic system, the strengthening of post-treatment, and the design of a circular economy system to significantly improve the product yield and the environmental friendliness of the process.

[0025] The present invention also includes a recycling system to achieve efficient resource utilization and environmental friendliness. The recycling system includes three parts: waste heat recovery, solvent recovery and wastewater treatment. The waste heat is converted into 7°C cold water by the lithium bromide unit and reused for reaction temperature control. The phase-separated water phase is recovered by a vacuum distillation-extraction tower to recover more than 98% of the remaining 2-butanone, and the waste solvent is purified by molecular distillation. The COD value of the wastewater after treatment is lower than 50 mg / L, which meets the discharge requirements of the urban pipe network. The recycling system can significantly reduce cooling water consumption and raw material procurement costs, while ensuring that the wastewater meets the discharge standards.

[0026] Compared with the prior art, the present invention has the following beneficial effects: the present invention realizes the efficient and green preparation of 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane through the design of a three-stage microchannel reactor, optimization of the catalytic system and strengthening of post-treatment. The method significantly improves the purity, selectivity and stability of the product, while reducing energy consumption and environmental burden, and has important industrial application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the Trigonox 301 H NMR spectrum of the oil phase in Example 1.

[0028] In the figure: 3.00 and 3.09 represent the hydrogen atoms on the two methyl groups, and the hydrogen atoms on the dimethylene group are split into 0.93 and 1.46 in the NMR spectrum.

[0029] Figure 2 This is the Trigonox 301 NMR carbon spectrum of the oil phase in Example 1.

[0030] In the figure: 1.09.65 is the split peak of the carbon atom connected to the oxygen atom due to the symmetrical structure, and the other carbon atoms are affected and the peaks are split. 2.18.13 and 8.33 correspond to two methyl carbons respectively, and 26.81 is a methylene carbon.

[0031] Figure 3 The HPLC result of the oil phase in Example 1 is shown in FIG.

[0032] In the figure: the peak at 5.225 min is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane.

[0033] Figure 4 This is the HPLC result of the oil phase in Example 2.

[0034] In the figure: the peak at 5.213 min is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane.

[0035] Figure 5 HPLC results of the oil phase in Example 3.

[0036] In the figure: The peak at 4.75 min is the peak of 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane.

[0037] Figure 6 HPLC results of the oil phase in Example 4.

[0038] In the figure: The peak at 4.7428 min is the peak of 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane. Detailed implementation mode

[0039] The present invention will be specifically described below through examples. Unless otherwise stated, the raw materials used are commercially available.

[0040] The technical solution of the present invention will be described as a whole below.

[0041] First, for the three-stage microchannel reactor used in the present invention: The primary channel is a serpentine structure with a diameter of 2 ± 0.2 mm, which is used to achieve high-shear mixing and promote the rapid and uniform dispersion of raw materials. The secondary channel is a spiral structure with a diameter of 1 ± 0.2 mm, and its inner wall is loaded with TiO 2 -Ag nanophotocatalyst, which reduces the reaction activation energy under ultraviolet light irradiation. The final channel is a straight channel with a diameter of 2 ± 0.2 mm, and supercritical CO 2 is introduced. Its pressure is set to 7.4 MPa to 7.8 MPa, and the temperature is set to 32 ± 0.5 °C to reduce the viscosity of the material and improve the mass transfer efficiency. Further, the surface of the channel is grafted with perfluorosilane by plasma to form a superhydrophobic interface, thereby reducing material residue and water consumption for single-batch cleaning.

[0042] The raw materials include 2-butanone, hydrogen peroxide and a catalyst, which are first mixed in the primary channel. During the mixing process, the raw materials are subjected to strong shear force in the channel to form a uniform mixture, thus ensuring the efficient progress of subsequent reactions. The design of the serpentine channel can effectively increase the mixing path, improve the mixing effect, and reduce the generation of by-products caused by uneven reactions.

[0043] The secondary spiral channel, with the TiO 2 -Ag nanophotocatalyst loaded on its inner wall, is fixed on the channel surface by plasma technology. The loading amount of the catalyst is about 10 mg / cm² to ensure that it can effectively reduce the reaction activation energy under ultraviolet light irradiation. The wavelength of the ultraviolet light is set to 365 nm, the power is about 100 W, and the irradiation time is close to 30 minutes. Under the action of ultraviolet light, TiO 2The -Ag nanophotocatalyst can reduce the reaction activation energy from 48 kJ / mol to 34 kJ / mol, thus significantly improving the reaction rate and selectivity. The selection and loading method of the catalyst can effectively avoid catalyst shedding and ensure the continuity and stability of the reaction.

[0044] The use of supercritical CO 2 can significantly reduce the viscosity of the material and improve the mass transfer efficiency. In specific implementation, supercritical CO 2 is heated to about 32 °C by a preheater before entering the straight channel, and then sent into the reactor by a high-pressure pump. In the straight channel, supercritical CO 2 is mixed with the raw materials, and by reducing the viscosity and improving the mass transfer efficiency, it promotes the efficient progress of the reaction. The use of supercritical CO 2 can also reduce the generation of by-products and improve the product purity.

[0045] Furthermore, the surface of the three-stage microchannel reactor is formed with a superhydrophobic interface by plasma grafting perfluorosilane.

[0046] The specific steps of plasma treatment are as follows: First, the surface of the reactor is plasma-cleaned to remove surface impurities; then perfluorosilane is grafted in a plasma environment, the grafting time is about 30 minutes, and the grafting power is 80 W - 120 W. The grafting density of perfluorosilane is about 10 μg / cm², forming a superhydrophobic interface. The superhydrophobic interface can significantly reduce the residue of the material on the reactor surface and reduce the water consumption for single-batch cleaning. In specific implementation, after each use, the reactor is rinsed with clean water. Due to the existence of the superhydrophobic interface, the water consumption is reduced by more than 75%.

[0047] The present invention also optimizes the catalytic system, and uses the ionic liquid [BMIM][HSO 4 and 80% sulfuric acid compounded in a ratio of 1:2.6 - 3.3 as the catalyst. The catalytic system is combined with a segmented temperature control process. The reaction temperature in the primary channel is 15 ± 2 °C; the reaction temperature in the secondary channel is 22 ± 2 °C; the reaction temperature in the final channel is 32 ± 0.5 °C. In particular, the ionic liquid-acid composite system can not only reduce side reactions and increase the yield, but also reduce the sulfuric acid consumption and the cost of waste acid treatment. At the same time, it balances the reaction rate through dynamic feeding and improves the space-time yield.

[0048] In specific implementation, the preparation steps of the ionic liquid [BMIM][HSO 4 are as follows: 1-butyl-3-methylimidazolium bromide ([BMIM]Br) and sodium bisulfate (NaHSO 4 are reacted at a molar ratio of 1:3 - 3.5 at 100 °C - 105 °C for 100 min - 150 min to obtain [BMIM][HSO 4Ionic liquid. The ionic liquid is mixed with sulfuric acid in a certain proportion to form a composite catalyst. The usage amount of the composite catalyst is 5% of the total amount of raw materials. Using this composite catalyst can increase the selectivity of the reaction to more than 98.5%.

[0049] The present invention also relates to the intensification of the post-treatment process, which includes two main steps: phase separation treatment and solvent recovery. In the phase separation treatment stage, the reaction solution enters a pulsed electric field phase separation tank, and the field strength is set to 550 ± 5 V / cm. In the solvent recovery stage, the aqueous phase recovers the residual 2-butanone through a molecular sieve adsorption tower, and the waste acid solution is neutralized with magnesium oxide to form magnesium sulfate crystals. Among them, the electric field-assisted phase separation can significantly shorten the phase separation time and reduce the water content in the oil phase.

[0050] Specifically, when implemented, it is preferred that the length of the pulsed electric field phase separation tank is 1000 mm, the width is 500 mm, and the height is 300 mm. The reaction solution is heated to 30 °C by a preheater before entering the phase separation tank, and then undergoes phase separation treatment under the action of a pulsed electric field of about 550 V / cm. The frequency of the pulsed electric field is 50 Hz, and the treatment time is 25 minutes. Under the action of the electric field, the oil phase and the aqueous phase can be quickly separated, the phase separation time is shortened from 2 hours to 25 minutes, and the water content in the oil phase is reduced to less than 0.3%.

[0051] In the solvent recovery stage, the aqueous phase recovers the residual 2-butanone through a molecular sieve adsorption tower. The height of the molecular sieve adsorption tower is 2000 mm, and the diameter is 500 mm. The aqueous phase is heated to 30 °C by a preheater before entering the adsorption tower, and then undergoes adsorption treatment through the molecular sieve in the adsorption tower. The type of molecular sieve is 3A molecular sieve, and the adsorption time is 30 minutes. The specific steps for the waste acid solution to be neutralized with magnesium oxide to form magnesium sulfate crystals are as follows: The waste acid solution and magnesium oxide are stirred and reacted at a molar ratio of 1:1.2 at 30 °C for 30 minutes, and the generated magnesium sulfate crystals are separated by centrifugation, with a purity reaching 99.2%. The recovery rate of magnesium sulfate crystals exceeds 95%.

[0052] The following are specific examples of the present invention. The same specifications of the three-stage microchannel reactor are used in each example. The first-stage channel is a serpentine structure with an inner diameter of 2 mm and a length of 1000 mm; the second-stage channel is a spiral structure with an inner diameter of 1 mm and a length of 500 cm; the last-stage channel is a straight channel with a diameter of 2 mm and a length of 2000 cm. Example 1

[0053] 1. Preparation of raw materials and equipment: Prepare 2-butanone, hydrogen peroxide, and a composite sulfuric acid catalyst. The composite sulfuric acid catalyst used in this example is [BMIM][HSO 4A catalyst compounded with 80% sulfuric acid (calculated as pure sulfuric acid) at a mass ratio of 1:3. The purity of 2-butanone is 99.5%, and the concentration of hydrogen peroxide is 30%. The inner wall surfaces of the three-stage microchannel reactor are all attached with a superhydrophobic interface formed by plasma grafting perfluorosilane.

[0054] 2. Primary mixing: Mix 2-butanone and hydrogen peroxide at a mass ratio of 1:1, add a composite sulfuric acid catalyst accounting for 2.5% of the mass of 2-butanone, and then send it into the serpentine channel through a high-pressure pump. The mixing time is 300 s, the temperature is 15 °C, and a uniform mixture is formed.

[0055] 3. Secondary catalysis: Feed the mixed raw materials into the spiral channel, and the inner wall of the channel is loaded with TiO 2 -Ag nanophotocatalyst. The loading amount of the catalyst is 10 mg / cm², the wavelength of the ultraviolet light is 365 nm, the power is 100 W, the irradiation time is 30 min, and the reaction temperature is 22 °C.

[0056] 4. Final treatment: Feed the catalyzed raw materials into the straight channel, and introduce supercritical CO 2 , with its pressure set at 7.6 MPa, the reaction time is 60 min, and the reaction temperature is 32 °C.

[0057] 5. Phase separation treatment: Heat the reaction solution to 30 °C through a preheater, and then enter the pulsed electric field phase separation tank. The electric field strength is 550 V / cm, the frequency is 50 Hz, and the phase separation time is 25 minutes. The oil phase and the water phase are quickly separated. The water phase recovers the residual 2-butanone through a molecular sieve adsorption tower, and the waste acid liquid is neutralized with magnesium oxide to generate magnesium sulfate crystals for recovery. The obtained oil phase is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane, with a water content of 0.12%, and is subjected to HPLC analysis. The HPLC analysis shows that the actual reaction yield in this example is 95.945% when calculating the theoretical yield based on 2-butanone. Example 2

[0058] 1. Preparation of raw materials and equipment: Prepare 2-butanone, hydrogen peroxide, and a composite sulfuric acid catalyst. The composite sulfuric acid catalyst used in this example is [BMIM][HSO 4 compounded with 50% sulfuric acid (calculated as pure sulfuric acid) at a mass ratio of 1:2.8. The purity of 2-butanone is 99.0%, and the concentration of hydrogen peroxide is 35%. The inner wall surfaces of the three-stage microchannel reactor are all attached with a superhydrophobic interface formed by plasma grafting perfluorosilane.

[0059] 2. Primary mixing: Mix 2-butanone and hydrogen peroxide at a mass ratio of 0.6:1, add a composite sulfuric acid catalyst accounting for 2% of the mass of 2-butanone, and then send it into the serpentine channel through a high-pressure pump. The mixing time is 25 s, the temperature is 16 °C, and a uniform mixture is formed.

[0060] 3. Secondary catalysis: Feed the mixed raw materials into a spiral channel, and the inner wall of the channel is loaded with TiO 2 -Ag nanophotocatalyst. The loading amount of the catalyst is 9 mg / cm², the wavelength of the ultraviolet light is 365 nm, the power is 120 W, the irradiation time is 28 min, and the reaction temperature is 23 °C.

[0061] 4. Final treatment: Feed the catalyzed raw materials into a straight channel, and introduce supercritical CO 2 with its pressure set at 7.5 MPa, the reaction time is 65 min, and the reaction temperature is 32 °C.

[0062] 5. Phase separation treatment: Heat the reaction solution to 30 °C through a preheater, and then enter a pulsed electric field phase separation tank with an electric field strength of 550 V / cm, a frequency of 50 Hz, and a phase separation time of 25 minutes. The oil phase and the water phase are rapidly separated. The water phase recovers the residual 2-butanone through a molecular sieve adsorption tower, and the waste acid liquid is neutralized with magnesium oxide to generate magnesium sulfate crystals for recovery. The obtained oil phase is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane with a water content of 0.1%, and HPLC analysis is carried out. The HPLC analysis shows that the actual reaction yield in this example is 95.886% when calculating the theoretical yield based on 2-butanone. Example 3

[0063] 1. Preparation of raw materials and equipment: Prepare 2-butanone, hydrogen peroxide, and a composite sulfuric acid catalyst. The composite sulfuric acid catalyst used in this example is a catalyst prepared by compounding [BMIM][HSO 4 and 80% sulfuric acid (calculated as pure sulfuric acid) in a mass ratio of 1:3.1. The purity of 2-butanone is 99.5%, and the concentration of hydrogen peroxide is 25%. The inner wall surfaces of the three-stage microchannel reactor are all attached with a superhydrophobic interface formed by plasma grafting perfluorosilane.

[0064] 2. Primary mixing: Mix 2-butanone and hydrogen peroxide in a mass ratio of 1.2:1, add a composite sulfuric acid catalyst accounting for 3% of the mass of 2-butanone, and then feed it into a serpentine channel through a high-pressure pump. The mixing time is 35 s, the temperature is 14 °C, and a uniform mixture is formed.

[0065] 3. Secondary catalysis: Feed the mixed raw materials into a spiral channel, and the inner wall of the channel is loaded with TiO 2 -Ag nanophotocatalyst. The loading amount of the catalyst is 11 mg / cm², the wavelength of the ultraviolet light is 365 nm, the power is 100 W, the irradiation time is 32 min, and the reaction temperature is 21 °C.

[0066] 4. Final treatment: Feed the catalyzed raw materials into a straight channel, and introduce supercritical CO 2, with a pressure set at 7.7 MPa, a reaction time of 55 min, and a reaction temperature of 32 °C.

[0067] 5. Phase separation treatment: The reaction solution is heated to 30 °C through a preheater and then enters a pulsed electric field phase separation tank. The electric field strength is 550 V / cm, the frequency is 50 Hz, and the phase separation time is 25 minutes. The oil phase and the water phase are rapidly separated. The water phase recovers the residual 2-butanone through a molecular sieve adsorption tower, and the waste acid liquid is neutralized with magnesium oxide to generate magnesium sulfate crystals for recovery. The obtained oil phase is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane, with a water content of 0.1%, and is subjected to HPLC analysis. The HPLC analysis shows that the actual reaction yield in this example is 94.612% when calculating the theoretical yield based on 2-butanone. Example 4

[0068] 1. Preparation of raw materials and equipment: Prepare 2-butanone, hydrogen peroxide, and a composite sulfuric acid catalyst. The composite sulfuric acid catalyst used in this example is a catalyst prepared by compounding [BMIM][HSO 4 and 80% sulfuric acid (calculated as pure sulfuric acid) at a mass ratio of 1:2.6. The purity of 2-butanone is 99.0%, and the concentration of hydrogen peroxide is 25%. The inner wall surfaces of the three-stage microchannel reactor are all attached with a superhydrophobic interface formed by plasma grafting perfluorosilane.

[0069] 2. Primary mixing: Mix 2-butanone and hydrogen peroxide at a mass ratio of 0.5:1. After adding 5% of the mass of 2-butanone of the composite sulfuric acid catalyst, it is sent into a serpentine channel through a high-pressure pump. The mixing time is 20 s, and the temperature is 13 °C to form a uniform mixture.

[0070] 3. Secondary catalysis: Send the mixed raw materials into a spiral channel, and the inner wall of the channel is loaded with TiO 2 -Ag nanophotocatalyst. The loading amount of the catalyst is 2 mg / cm², the wavelength of the ultraviolet light is 365 nm, the power is 100 W, the irradiation time is 25 min, and the reaction temperature is 20 °C.

[0071] 4. Final treatment: Send the catalyzed raw materials into a straight channel and introduce supercritical CO 2 , with a pressure set at 7.4 MPa, a reaction time of 70 min, and a reaction temperature of 31.5 °C.

[0072] 5. Phase separation treatment: The reaction solution is heated to 35°C by a preheater and then enters a pulsed electric field phase separation tank with an electric field strength of 555 V / cm, a frequency of 60 Hz, and a phase separation time of 20 minutes. The oil phase and the water phase are rapidly separated. The water phase recovers the residual 2-butanone through a molecular sieve adsorption tower, and the waste acid solution is neutralized with magnesium oxide to recover magnesium sulfate crystals. The obtained oil phase is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane with a water content of 0.1%, and HPLC analysis is performed. The HPLC analysis shows that the actual reaction yield in this example is 94.114% when calculating the theoretical yield based on 2-butanone. Example 5

[0073] 1. Preparation of raw materials and equipment: Prepare 2-butanone, hydrogen peroxide, and a composite sulfuric acid catalyst. The composite sulfuric acid catalyst used in this example is a catalyst prepared by compounding [BMIM][HSO 4 and 80% sulfuric acid (calculated as pure sulfuric acid) at a mass ratio of 1:3.3. The purity of 2-butanone is 99.5%, and the concentration of hydrogen peroxide is 30%. The inner wall surfaces of the three-stage microchannel reactor are all attached with a superhydrophobic interface formed by plasma grafting perfluorosilane.

[0074] 2. Primary mixing: Mix 2-butanone and hydrogen peroxide at a mass ratio of 1.5:1, add a composite sulfuric acid catalyst accounting for 1% of the mass of 2-butanone, and then send it into a serpentine channel through a high-pressure pump. The mixing time is 40 s, and the temperature is 17°C to form a uniform mixture.

[0075] 3. Secondary catalysis: Send the mixed raw materials into a spiral channel, and the inner wall of the channel is loaded with a TiO 2 -Ag nanophotocatalyst. The loading amount of the catalyst is 8 mg / cm², the wavelength of the ultraviolet light is 365 nm, the power is 150 W, the irradiation time is 35 min, and the reaction temperature is 24°C.

[0076] 4. Final treatment: Send the catalyzed raw materials into a straight channel, and introduce supercritical CO 2 , with its pressure set at 7.8 MPa, the reaction time is 50 min, and the reaction temperature is 32.5°C.

[0077] 5. Phase separation treatment: The reaction solution is heated to 25°C by a preheater and then enters a pulsed electric field phase separation tank with an electric field strength of 545 V / cm, a frequency of 45 Hz, and a phase separation time of 30 minutes. The oil phase and the water phase are rapidly separated. The water phase recovers the residual 2-butanone through a molecular sieve adsorption tower, and the waste acid solution is neutralized with magnesium oxide to recover magnesium sulfate crystals. The obtained oil phase is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane with a water content of 0.1%, and HPLC analysis is performed. The HPLC analysis shows that the actual reaction yield in this example is 93.434% when calculating the theoretical yield based on 2-butanone.

[0078] Comparative Example 1

[0079] The basic process is the same as that of Example 1, except that 80% sulfuric acid is used instead of the composite sulfuric acid catalyst. The obtained oil phase is analyzed by HPLC. The HPLC analysis shows that the actual reaction yield of this example is 81.387% when calculating the theoretical yield based on 2-butanone.

[0080] Comparative Example 2

[0081] The basic process is the same as that of Example 1, except that the three-stage microchannel reactor is not used, and the materials only react in a serpentine microchannel reactor with an inner diameter of 2 mm without any catalyst on the inner wall, with a length of 2600 cm and a reaction time of 91 min. The obtained oil phase is analyzed by HPLC. The HPLC analysis shows that the actual reaction yield of this example is 93.189% when calculating the theoretical yield based on 2-butanone.

[0082] As described above, it is only the preferred embodiment of the present invention, and it is not intended to limit the present invention in other forms. Any person skilled in the art may use the disclosed technical content to make changes or modifications into equivalent embodiments with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution content of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing TEMTP, characterized in that: The method comprises the following steps: in a three-stage microchannel reactor, an organic ketone and hydrogen peroxide are subjected to a synthesis reaction under the catalysis of a composite sulfuric acid catalyst, and an oil phase separated from the system after the reaction is 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane; wherein the reaction temperature is 10°C to 30°C; the total reaction time in the three-stage microchannel is 1h to 2h; the feed molar ratio of the organic ketone to the hydrogen peroxide is 0.5 to 1.5:1; and the organic ketone is butanone; The three-stage microchannel reactor is as follows: the first-stage channel is a 2±0.2 mm serpentine structure; the secondary channel is a 1±0.2 mm spiral structure, with the inner wall loaded with TiO2-Ag nano-photocatalyst; the final channel is a 2±0.2 mm straight channel, with supercritical CO2 introduced; The composite sulfuric acid catalyst is a composite catalyst of ionic liquid [BMIM][HSO4] and sulfuric acid in a mass ratio of 1:2.6-3.3, and the addition amount of the composite sulfuric acid catalyst is 1%-5% of the mass of the organic ketone; the preparation steps of the composite sulfuric acid catalyst ionic liquid [BMIM][HSO4] are as follows: 1-butyl-3-methylimidazolium bromide and sodium bisulfate are reacted at a molar ratio of 1:3-3.5 at 100°C-105°C for 100min-150min to obtain [BMIM][HSO4] ionic liquid; the ionic liquid and sulfuric acid are mixed in proportion to obtain the composite sulfuric acid catalyst.

2. The method for preparing TEMTP according to claim 1, characterized in that: The length of the primary channel is 1000±100 mm, the loading amount of the TiO2-Ag nano-photocatalyst loaded on the inner wall of the secondary channel is 8 mg / cm²~12 mg / cm², and 365 nm ultraviolet light irradiation is additionally performed.

3. The method for preparing TEMTP according to claim 1, characterized in that: The pressure of the supercritical CO2 in the final channel is set to 7.4MPa~7.8MPa.

4. The method for preparing TEMTP according to claim 1, characterized in that: The inner wall surfaces of the three-stage microchannel reactor are all covered with super-hydrophobic interfaces formed by plasma grafted perfluorosilane.

5. The method for preparing TEMTP according to claim 4, characterized in that: The processing steps of the super-hydrophobic interface formed by plasma grafting perfluorosilane are as follows: 1) First, the reactor surface is plasma cleaned to remove surface impurities; 2) Then, perfluorosilane was grafted under plasma environment. The grafting time was 30±5 minutes, the grafting power was 100±5W, and the grafting density of perfluorosilane was 10±2μg / cm 2 , forming a super-hydrophobic interface.

6. The method for preparing TEMTP according to claim 1, characterized in that: The reaction temperature in the first-stage channel is 15±2°C, and the reaction time is 20s~40s; the reaction temperature in the secondary channel is 22±2°C, and the reaction time is 25min~35min; the reaction temperature in the final channel is 32±0.5°C, and the reaction time is 50min~70min; the feed molar ratio of the organic ketone to the hydrogen peroxide is 0.6~1.2:

1.

7. The method for preparing TEMTP according to claim 1, characterized in that: When the oil phase is separated, the reaction solution is carried out in a pulse electric field phase separation tank, and the field strength of the pulse electric field phase separation tank is set to 550±5V / cm.

8. The method for preparing TEMTP according to claim 1, characterized in that: The method also includes a solvent recovery step, in which the aqueous phase is passed through a molecular sieve adsorption tower to recover residual 2-butanone, and the waste acid liquid is neutralized with magnesium oxide to generate magnesium sulfate crystals for recovery.

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