Method for synthesizing phenol acetone by continuously catalyzing CHP decomposition through fixed bed

Abstract

The invention relates to the field of organic chemical industry, and discloses a method for synthesizing phenol acetone by continuously catalyzing CHP decomposition through a fixed bed. According to the method, a pretreated CHP raw material is introduced into a microwave-assisted fixed bed reactor, and under the regulation and control of a microwave energy self-adaptive control unit and a fiber grating temperature sensing array, a composite functional catalyst containing a microwave strong absorption component is used for catalytic decomposition, so that the problems of coking and safety caused by local overheating of a traditional reaction are solved. According to the invention, the bulk phase of the reaction system is uniformly heated, the radial temperature difference is effectively eliminated, the once-through yield of phenol is stably increased, the side reaction is inhibited, the service life of the catalyst is prolonged, and meanwhile, the energy efficiency ratio and the process controllability are increased.

Description

Technical Field

[0001] This invention belongs to the field of organic chemical engineering, and specifically relates to a method for the continuous catalytic decomposition of CHP in a fixed bed to synthesize phenol and acetone. Background Technology

[0002] Among existing technologies, fixed-bed reactors are widely used in the catalytic decomposition of CHP due to their advantages such as high degree of continuous operation, easy separation of catalyst and product, and high yield per unit volume. Traditional fixed-bed processes typically use external heating or jacket cooling for temperature control, achieving energy input or removal through heat conduction between the external heat exchange medium and the reaction system.

[0003] Traditional fixed-bed reactors exhibit significant energy transfer lag and non-uniformity when handling highly exothermic reactions such as CHP decomposition. Due to the limited thermal conductivity of the catalyst bed and the fact that the reaction often occurs instantaneously at the catalyst's active sites, the heat generated cannot be rapidly conducted to the heat exchange interface within microsecond timescales. This severe mismatch between the heat transfer rate and the reaction rate easily induces severe overheating in localized areas of the fixed bed.

[0004] Under these conditions, α-methylstyrene, one of the target products, is prone to uncontrolled polymerization, leading to the formation of heavy tar and complex oligomers. These byproducts not only directly reduce the overall yield of phenol and acetone, but the generated tar-like substances also gradually cover the surface of catalyst particles, clogging micropores and hindering the diffusion of the reaction substrate to the active sites, thus causing premature degradation of catalyst activity and shortening the industrial regeneration cycle of the catalyst.

[0005] Traditional heating methods follow an inward heat transfer pattern from the reactor wall to the center of the bed. This cascaded heat transfer inevitably leads to temperature gradients in the radial and axial directions of the reactor. This temperature inconsistency means that CHP molecules in different spatial locations receive different energy densities, making it difficult to achieve a precise and uniform activation energy supply at the molecular level. Under this crude energy regulation mechanism, a relatively high external supply temperature is often required to ensure the overall reaction conversion rate, resulting in significant energy waste. Summary of the Invention

[0006] To achieve the above-mentioned objectives, this invention provides a method for the continuous catalytic decomposition of CHP in a fixed bed to synthesize phenol and acetone. The method involves continuously feeding a CHP solution into a microwave-assisted fixed-bed reactor packed with a specific catalyst, and completing the catalytic decomposition reaction under a controlled microwave electromagnetic field environment to produce a mixture stream containing phenol, acetone, and a small amount of byproducts.

[0007] This invention provides a method for the continuous fixed-bed catalytic decomposition of CHP to synthesize phenol and acetone. The system comprises a feed metering unit, a microwave-assisted fixed-bed reaction unit, a product condensation and collection unit, and a microwave energy adaptive control unit. The feed metering unit delivers a CHP-containing feed solution to the reaction unit at a constant mass flow rate via a high-pressure precision plunger pump. The microwave-assisted fixed-bed reaction unit includes a microwave resonant cavity, a microwave transmission reaction tube coaxially disposed within the resonant cavity, and a composite functional catalyst bed filled within the reaction tube. The microwave energy adaptive control unit includes a microwave generator, a waveguide transmission system, and a multi-point fiber optic temperature sensing array disposed at key axial and radial locations within the catalyst bed.

[0008] The core process flow of the method described in this invention is as follows: First, the mixed raw material containing CHP, cumene, and phenol-acetone solvent is subjected to dehydration pretreatment to reduce the water content in the raw material to below 500 ppm. Then, the pretreated raw material is heated to a preheating temperature of 35°C to 45°C and heated for 1.0 h. -1 Up to 15.0h -1 Liquid space velocity (LSH) is introduced into the microwave transmission reaction tube. As the raw material flows through the composite functional catalyst bed, a microwave generator emits continuous microwave waves at a frequency of 2450 MHz or 915 MHz, which are coupled into the microwave resonant cavity through a waveguide. The microwave electromagnetic field penetrates the tube wall and directly acts on the catalyst particles and CHP molecules inside the tube. During the reaction, the internal temperature of the bed is monitored in real time by the multi-point fiber optic temperature sensor array. The microwave energy adaptive control unit adjusts the microwave output power according to the temperature feedback signal, ensuring that the temperature fluctuation deviation of the entire catalyst bed is controlled within ±0.5 degrees Celsius, and maintaining a constant temperature of 50 to 75 degrees Celsius in the reaction area. The reacted material flows out from the reaction tube outlet and enters the product condensation and collection unit. After staged cooling and condensation, crude phenol and acetone products are obtained.

[0009] In the method described in this invention, the microwave transmission reaction tube is made of high-purity quartz or highly dense industrial-grade alumina ceramic, with a dielectric loss tangent of less than 0.0005 at the microwave frequency, ensuring that microwave energy can penetrate the tube wall without loss and enter the reaction system. The inner diameter of the reaction tube is matched with the microwave penetration depth in the reaction medium, and the inner diameter is set to 0.8 to 1.2 times the microwave penetration depth to ensure the uniformity of the microwave field distribution in the radial direction of the reaction tube.

[0010] In the method described in this invention, the composite functional catalyst comprises an acidic active center, a macroporous support matrix, and a microwave-absorbing component. The support matrix is ​​a mesoporous molecular sieve with a hierarchical pore structure or modified γ-alumina, with a specific surface area between 150 m² / g and 350 m² / g. The acidic active center is a heteropolyacid, a modified molecular sieve active site, or a sulfate-treated metal oxide supported on the support surface. The microwave-absorbing component is silicon carbide, magnetic iron oxide, or graphitized carbon nanomaterials uniformly dispersed within the pores of the support or on the surface of the particles, accounting for 5% to 20% of the total catalyst weight. This composite structure enables the catalyst to not only possess highly efficient chemical activity for catalyzing CHP decomposition but also extremely high microwave-to-thermal energy conversion efficiency. It can rapidly heat up under a microwave field and generate a microscopic hotspot effect, directly exciting CHP molecules adsorbed on the active sites.

[0011] The preparation process of the composite functional catalyst of this invention includes the following steps: First, a precursor suspension containing a strong microwave absorber is prepared using a co-precipitation method or a sol-gel method. Then, the precursor suspension is impregnated with a macroporous support matrix in equal volumes and dried at 80°C to 120°C for 12 hours. Next, the dried material is calcined at 450°C to 650°C under a nitrogen atmosphere to allow the strong microwave absorber to form a stable crystalline structure and firmly adhere to the support framework. Finally, acidic active centers are introduced using an impregnation method, and the catalyst is activated by a second low-temperature calcination.

[0012] In the method described in this invention, the microwave energy adaptive control unit employs closed-loop feedback control logic. Because traditional metal thermocouples generate induced current and tip discharge phenomena in microwave fields, severely interfering with temperature measurement accuracy and potentially damaging the equipment, the fiber grating temperature sensing array selected in this invention is immune to electromagnetic interference. The sensing array consists of at least five sensing nodes distributed at different heights along the axial direction of the reaction tube, each node capable of independently feeding back the instantaneous temperature of its local bed. The control system calculates the overall thermal intensity distribution of the bed by weighted averaging the temperature data from multiple nodes, and accordingly adjusts the anode current or pulse duty cycle of the microwave generator in real time to achieve fine-tuning of the microwave power.

[0013] In the method described in this invention, the CHP decomposition reaction exhibits a coupling characteristic of non-thermal effects and enhanced thermal effects under microwave field driving. The microwave electromagnetic field can directly act on the strongly polar peroxy bonds in the CHP molecule, increasing the vibrational energy level of the peroxy bonds through dipole reversal polarization, thereby reducing the apparent activation energy of the decomposition reaction. Simultaneously, the microscopic hot zone formed within the catalyst micropores by the microwave strong absorbing component can precisely transfer energy to the reaction interface, rather than heating the entire fluid phase through macroscopic heat conduction. This essentially eliminates the radial temperature gradient caused by external heating in traditional fixed-bed reactors.

[0014] The method described in this invention controls the reaction pressure within a range of 0.1 MPa to 0.5 MPa. A back pressure regulating valve located at the rear end of the product condensation and collection unit maintains a slightly positive pressure within the system. This pressure setting ensures that the reaction product, acetone, remains in the liquid phase or a controlled gas-liquid mixture at the reaction temperature, facilitating the timely removal of reaction heat. It also prevents excessive flash evaporation of low-boiling-point components, which could lead to excessively high bed velocity, thus ensuring sufficient reaction contact time.

[0015] In the method described in this invention, the mass fraction of CHP in the feed solution is controlled between 60% and 90%. Before entering the fixed-bed reactor, the feed needs to pass through a multi-stage precision filter to remove solid particles larger than 1 micrometer in diameter to prevent physical blockage of the catalyst bed. Simultaneously, to further suppress side reactions, a polymerization inhibitor with a mass fraction of 50 ppm to 200 ppm can be added to the feed to capture free radicals that may be generated during the reaction.

[0016] In the method described in this invention, the start-up process of the microwave-assisted fixed-bed reactor includes a preheating stage, a microwave power ramp-up stage, and a steady-state operation stage. In the preheating stage, preheated solvent is first introduced into the reaction tube via a circulating pump, causing the overall temperature of the catalyst bed to rise uniformly to 45 degrees Celsius. In the microwave power ramp-up stage, the microwave generator is turned on, and the power is gradually increased from an initial 50 watts at a rate of 10 watts per minute, while simultaneously observing the feedback from the temperature sensor array, until the center temperature of the bed reaches the preset decomposition temperature. In the steady-state operation stage, the feed is switched to a CHP feed solution, and thermal balance is maintained by the control unit.

[0017] The method described in this invention comprises a product condensation and collection unit including a primary gas-liquid separator, a secondary high-efficiency condenser, and a crude product storage tank. The mixture flowing from the reaction tube enters the primary gas-liquid separator. The separated gaseous components enter the secondary high-efficiency condenser, where they are fully liquefied under the action of a condensing medium at -5°C to 0°C. The liquid components are then directly collected in the crude product storage tank. The crude product is subsequently sent to a subsequent distillation section, where acetone, cumene, α-methylstyrene, and phenol are sequentially separated through vacuum distillation.

[0018] In the method described in this invention, the microwave-assisted fixed-bed reactor can also be designed as a multi-tube parallel structure to meet the throughput requirements of large-scale industrial production. Each reaction tube unit is independently equipped with a microwave feed interface and a temperature monitoring node, and the power distribution of each reaction unit is balanced and adjusted through a central control system to ensure the consistency of operation of large-scale equipment.

[0019] The method of this invention exhibits good adaptability when processing industrial-grade CHP feedstock containing impurities. For common impurities in the feedstock, such as dimethylbenzyl alcohol and acetophenone, the competitive adsorption of these impurities on the acidic sites of the catalyst is mitigated to some extent under the action of a microwave field, thereby ensuring the efficient conduct of the CHP decomposition reaction.

[0020] The method described in this invention, during the shutdown protection phase, rapidly cuts off the microwave output through a microwave energy adaptive control unit while simultaneously introducing room-temperature cumene as a flushing fluid. Due to the instantaneous cessation of microwave heating, the bed temperature can drop in a very short time, effectively avoiding prolonged material retention at high temperatures during shutdown and preventing catalyst coking.

[0021] In a preferred embodiment of the present invention, the acidic active center of the composite functional catalyst is phosphotungstic acid or silicotungstic acid, and its loading on the support is 15% to 30% by mass. The microwave strong absorbing component is nanoscale silicon carbide powder with an average particle size controlled between 50 nanometers and 200 nanometers to ensure the formation of highly dispersed adsorption centers on the support surface.

[0022] As another preferred embodiment of the present invention, the microwave resonant cavity of the microwave-assisted fixed bed reaction unit is provided with a mode stirrer. By continuously rotating the mode stirrer, the spatial distribution of the electromagnetic field in the cavity is changed, and any possible electromagnetic field standing wave nodes are further eliminated, thereby ensuring the high uniformity of heating of multiple reaction tubes in the resonant cavity.

[0023] In another preferred embodiment of the present invention, the sleeve surface of the fiber grating temperature sensing array is coated with a polytetrafluoroethylene anti-corrosion layer to resist the corrosion of acidic media in the reaction system and ensure the signal reliability of the sensor during long-term operation.

[0024] In the method described in this invention, the microwave energy adaptive control unit also integrates safety interlock logic to address the strongly exothermic characteristics of the CHP decomposition reaction. When the fiber optic temperature sensing array detects that the temperature rise rate at any point exceeds a preset threshold (e.g., 2 degrees Celsius per second), the system will automatically trigger an emergency power reduction procedure, or even completely cut off the microwave source and activate the emergency cooling circuit. This safety mechanism based on the instantaneous adjustability of microwave power is something that traditional heat conduction heating processes cannot achieve, greatly improving the safety of fixed-bed reactors in handling high-concentration, highly reactive chemical systems.

[0025] If the activity of the composite functional catalyst described in this invention decreases after a certain period of use, it can be repaired using microwave in-situ regeneration technology. By switching the reactor to regeneration mode and introducing a nitrogen stream containing diluted oxygen, the selective heating effect of microwaves on the carbon deposits on the catalyst surface is utilized to achieve efficient oxidation and removal of carbon deposits at a relatively low apparent temperature. This restores the acidic active sites of the catalyst, thereby extending the overall catalyst replacement cycle and reducing operating costs.

[0026] In implementing the method of this invention, the microwave generator preferably uses a solid-state microwave source. Solid-state microwave sources have advantages such as high frequency stability, controllable phase, good power regulation linearity, and long lifespan, and can provide more precise energy output than traditional magnetrons, thereby enabling extreme control of the reaction process in conjunction with the adaptive control unit.

[0027] The method described in this invention fully utilizes the multiple reflections and interference effects of microwaves in the reaction medium by designing a specific ratio between the inner diameter of the reaction tube and the microwave wavelength. This results in the electromagnetic field intensity exhibiting a distribution characteristic of slightly higher intensity in the center and slightly lower intensity at the edges in the radial distribution of the catalyst bed. This precisely compensates for the slight heat loss from the reactor tube wall and achieves true radial isothermal operation.

[0028] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention utilizes the penetrability of microwaves to achieve uniform heating of the bulk phase of the reaction system, enabling the temperature of the active sites on the catalyst surface to quickly reach the reaction requirements, while the temperature of the bulk fluid in the bed can be maintained at a relatively low level, suppressing side reactions induced by local overheating, such as the dimerization and polymerization reactions of α-methylstyrene. 2. By using microwaves to directionally excite the polar bonds of CHP, the reaction path is shifted towards the formation of the target products phenol and acetone. Under the same conversion rate, the amount of by-product tar generated is reduced compared with the traditional fixed-bed process, the selectivity of α-methylstyrene is precisely controlled, and the single-pass yield of phenol is steadily improved. 3. This invention slows down the deposition rate of heavy components in the catalyst micropores by eliminating macroscopic and microscopic hot spots. Simultaneously, the alternating electromagnetic force generated by the microwave field has a certain desorption-promoting effect on adsorbed molecules, helping the products to leave the active sites in a timely manner and maintaining the long-term activity stability of the catalyst. 4. The microwave energy adaptive control unit can respond to abnormal fluctuations in bed temperature within milliseconds. By adjusting the microwave power, it can compensate or reduce the rate of reaction heat release in real time, thereby enhancing the safety of the production unit. 5. Microwave energy is directly coupled to the reaction zone, reducing heat loss through heat exchange medium transfer, equipment casing heat loss, and environmental heat dissipation, which is common in external heating methods. Energy utilization efficiency is improved compared to traditional heat transfer oil heating, aligning with the development direction of green chemistry and low-carbon chemical engineering. Detailed Implementation

[0029] This invention provides a method for the continuous fixed-bed catalytic decomposition of CHP to synthesize phenol and acetone. This method achieves efficient, safe and highly selective conversion of CHP by integrating microwave field enhancement technology, precision fixed-bed reaction process and adaptive energy control system.

[0030] The technical solution of the present invention will be described in detail below with reference to specific embodiments and comparative examples, so as to ensure that those skilled in the art can fully understand and implement the present invention.

[0031] Example 1: CHP feedstock solution (CHP mass fraction 75%, water content 400ppm, polymerization inhibitor 120ppm); Composite functional catalyst (modified γ-alumina support, specific surface area 250 m²) 2 / g; phosphotungstic acid loading 22%; nano-silicon carbide microwave strong absorbing component 12%, particle size 120nm); Liquid air velocity 8.0 h⁻¹ -1 ; Reaction pressure: 0.3 MPa; Microwave frequency 2450MHz; Preparation and process steps: S1: Raw material pretreatment, CHP raw material is dehydrated by molecular sieve, multi-stage precision filtration, and polymerization inhibitor is added; preheat to 40℃; S2: Catalyst loading. The composite functional catalyst is activated by nitrogen roasting at 450℃ and then loaded into a quartz microwave transmission reaction tube. Five fiber grating temperature sensing nodes are arranged axially in the bed. S3: Reactor start-up, circulating solvent preheats the catalyst bed to 45°C; microwave power increases from 50W at 10W / min until the bed temperature reaches 62°C; S4: Microwave catalytic decomposition, feedstock at 8.0h -1Liquid air velocity is introduced into the reaction tube, and the microwave energy adaptive control unit dynamically adjusts the power to maintain the bed temperature at 62°C. S5: Product collection. After the reaction, the material enters the condensation and collection unit and is gradually cooled to 25°C to collect the crude phenol and acetone product. S6: Catalyst regeneration. After 1000 hours of operation, a nitrogen gas stream containing 5% oxygen is introduced, and microwave-assisted oxidation is used to remove carbon deposits.

[0032] Example 2: Same as Example 1; Preparation and process steps: Liquid space velocity 1.0 h⁻¹ -1 The remaining steps are the same as in Example 1.

[0033] Example 3: Same as Example 1; Preparation and process steps: Liquid space velocity 15.0 h⁻¹ -1 The remaining steps are the same as in Example 1.

[0034] Example 4: The composite functional catalyst contains 5% microwave-absorbing components, and the remaining components and proportions are the same as in Example 1; Preparation and process steps: Same as in Example 1.

[0035] Example 5: The composite functional catalyst contains 20% microwave-absorbing components, and the remaining components and proportions are the same as in Example 1; Preparation and process steps: Same as in Example 1.

[0036] Example 6: Same as Example 1; Preparation and process steps: The reaction temperature is 50℃, and the remaining steps are the same as in Example 1.

[0037] Example 7: Same as Example 1; Preparation and process steps: The reaction temperature is 75℃, and the remaining steps are the same as in Example 1.

[0038] Example 8: The microwave strong absorbing component was replaced with magnetic iron oxide (particle size 100nm), and the remaining components and proportions were the same as in Example 1; Preparation and process steps: Same as in Example 1.

[0039] Comparative Example 1: Same as Example 1; Preparation and process steps: Jacket heating is used instead of microwave field, and the remaining process parameters and steps are the same as in Example 1.

[0040] Comparative Example 2: The composite functional catalyst has no strong microwave absorption component, and the other components are the same as in Example 1; Preparation and process steps: Same as in Example 1.

[0041] Test method: Reaction efficiency test: High performance liquid chromatography was used to determine the CHP conversion rate, phenol yield, and acetone yield. Catalyst stability test: After 1000 hours of continuous operation, the CHP conversion rate decay rate was measured. Bed temperature test: Record the radial temperature difference of the bed to assess temperature uniformity; Energy consumption test: Statistical analysis of microwave energy consumption per unit of product, compared with traditional heating energy consumption; Coking test: The amount of carbon deposited on the catalyst is measured after operation.

[0042] The test data comparisons are shown in Table 1 and Table 2.

[0043] Table 1 Comparison of CHP conversion rate, phenol yield, acetone yield, and radial temperature difference in the bed

[0044] Table 2 Comparison of Conversion Rate Decay Rate, Catalyst Carbon Deposition, and Energy Consumption per Unit Product over 1000 hours

[0045] Examples 1 to 8 utilize microwave field to directionally excite CHP peroxy bonds, reducing activation energy; microwave-absorbent components achieve uniform heating of the bulk phase; and acidic active centers catalyze decomposition reactions. These three elements synergistically eliminate bed hotspots and suppress side reactions. Comparative Example 1, lacking a microwave field, suffers from a large radial temperature difference in the bed, resulting in severe carbon buildup and conversion rate degradation. Comparative Example 2, also lacking a microwave-absorbent component, exhibits poor heating uniformity, reduced energy consumption, and decreased stability.

[0046] Liquid air velocity 8.0 h⁻¹ -1 Up to 15.0h -1 When the component content is 12% to 20% and the reaction temperature is 62℃ to 75℃, the reaction efficiency and stability are better. Among them, the liquid space velocity affects the reaction contact time, the component content determines the microwave-thermal energy conversion efficiency, and the reaction temperature controls the kinetic rate. The three factors work together to ensure the overall performance of the process.

[0047] Compared to Comparative Example 1 without a microwave field, the phenol yield of the product in Example 1 is increased by more than 4.2%, the radial temperature difference of the bed is reduced by more than 93%, and the amount of carbon deposited on the catalyst is reduced by more than 79%. Compared to Comparative Example 2 without strong absorbing components, the CHP conversion rate is increased by more than 2.3%, the energy consumption per unit product is reduced by more than 37%, and the conversion rate decay rate over 1000 hours is reduced by more than 73%, meeting the requirements for continuous industrial production.

[0048] In summary, this invention achieves simultaneous improvements in efficient CHP decomposition, high selectivity, and low energy consumption through microwave field assistance and coupling with composite functional catalysts. It solves the core pain points of traditional fixed-bed processes, is suitable for large-scale production of phenol and acetone, and has good potential for industrialization.

[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for the continuous catalytic decomposition of CHP in a fixed bed to synthesize phenol and acetone, characterized in that, The system upon which the method relies includes a feed metering unit, a microwave-assisted fixed-bed reaction unit, a product condensation and collection unit, and a microwave energy adaptive control unit; the method includes the following steps: (1) Raw material pretreatment and transportation stage: The mixed raw material containing CHP, cumene and phenol acetone solvent is dehydrated and pretreated to reduce the water content in the raw material. The pretreated raw material solution is then transported to the microwave-assisted fixed bed reaction unit at a constant mass flow rate by the high-pressure precision plunger pump in the feed metering unit. (2) Preheating and feeding stage: The pretreated raw materials are heated to the preheating temperature and introduced into the microwave transmission reaction tube inside the microwave-assisted fixed bed reaction unit; (3) Microwave catalytic decomposition stage: During the process of the raw material flowing through the composite functional catalyst bed filled in the microwave transmission reaction tube, the microwave energy adaptive control unit drives the microwave generator to generate microwaves. The microwaves are coupled into the microwave resonant cavity through the waveguide transmission system and penetrate the wall of the microwave transmission reaction tube, directly acting on the composite functional catalyst particles and CHP molecules to complete the catalytic decomposition reaction. (4) Temperature real-time monitoring and power adaptive adjustment stage: The reacted material flows out from the microwave transmission reaction tube outlet and enters the product condensation and collection unit. After being cooled and condensed in stages, crude phenol acetone product is obtained. (5) Product condensation and collection stage; The composite functional catalyst in the microwave-assisted fixed-bed reaction unit is composed of an acidic active center, a macroporous support matrix, and a microwave-strong absorbing component. The carrier matrix is ​​a mesoporous molecular sieve with a hierarchical pore structure or modified γ-alumina; the acidic active center is a heteropoly acid, a modified molecular sieve active site, or a metal oxide treated with sulfate on the surface of the carrier matrix; the microwave strong absorbing component is silicon carbide, magnetic iron oxide, or graphitized carbon nanomaterials uniformly dispersed inside the pores or on the surface of the particles of the carrier matrix. The microwave transmission reaction tube is made of high-purity quartz or industrial-grade alumina ceramic with high density. The microwave strong absorbing component accounts for 5% to 20% of the total weight of the composite functional catalyst; the acidic active center is phosphotungstic acid or silicotungstic acid; the microwave strong absorbing component is selected from nano-sized silicon carbide powder.

2. The method for the continuous fixed-bed catalytic decomposition of CHP to synthesize phenol and acetone according to claim 1, characterized in that, The preparation process of the composite functional catalyst includes the following specific steps: Step 1: Prepare a precursor suspension containing microwave-absorbing components using a co-precipitation method or a sol-gel method; Step 2: Impregnate the precursor suspension and the macroporous carrier matrix with equal volumes and then dry. Step 3: Roast the dried material at high temperature; Step 4: The acidic active centers are introduced by impregnation, and the catalyst is activated by a second low-temperature calcination.

3. The method according to claim 1, characterized in that, The acidic active center is phosphotungstic acid or silicotungstic acid; the microwave strong absorbing component is nanoscale silicon carbide powder.

4. The method according to claim 1, characterized in that, The liquid space velocity of the raw material solution is 1.0 h⁻¹. -1 -15.0h -1 The reaction pressure is 0.1 MPa–0.5 MPa.

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