Continuous feeding reaction device for lignin photodegradation

Abstract

The invention relates to the technical field of chemical engineering and equipment, and discloses a continuous feeding reaction device for lignin photodegradation, which comprises a reaction tube, an LED light source array and a transducer arranged outside the reaction tube, and a rotating shaft arranged inside the reaction tube and driven by a rotation driving mechanism. A composite scraping mechanism is mounted on the rotating shaft and is used for forcibly scraping reaction liquid on the inner wall of the reaction tube to form a thin film. The transducer is used for generating an ultrasonic standing wave field to drive photocatalyst particles to form a high-density array; the LED light source array works in a pulse mode, and the triggering time of light pulses of the LED light source array is matched with the time when the density of the catalyst array reaches a peak value. Through the synergistic effect of dynamic film scraping self-cleaning, the sound field tissue catalyst and pulsed light synchronous irradiation, the problems of light shielding, easy blockage and slow mass transfer in a high-viscosity dark multiphase system are solved, and the reaction efficiency and stability are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical engineering and equipment technology, in particular to a continuous feeding reaction device for lignin photodegradation. BACKGROUND

[0002] Lignin, as the second most abundant natural organic polymer on earth after cellulose, is the only renewable aromatic compound resource. How to efficiently and high-value utilize lignin and convert it into platform compounds or high-value chemicals is the current research focus and core challenge in the field of biomass refining. Among the numerous conversion technologies, photocatalytic degradation shows great application potential due to its mild conditions, environmental friendliness, and adjustable product selectivity. This technology usually uses strong oxidizing free radicals generated by semiconductor photocatalysts (such as titanium dioxide and cadmium sulfide) under light to break the complex chemical bonds of lignin in liquid phase.

[0003] However, when applying photocatalytic technology to actual lignin degradation processes, especially in pursuit of industrialized continuous production, the existing reactor technology faces a series of interrelated inherent bottlenecks. First, lignin aqueous solution or organic solvent solution usually presents dark brown color and high viscosity, which physical properties lead to serious light shielding effect. In traditional tank or tubular slurry bed reactors, the incident light is quickly absorbed and scattered after entering the reaction liquid, with extremely shallow penetration depth, so that most of the photocatalyst particles suspended in the deep part of the reactor cannot be effectively excited, greatly limiting the effective volume of the reactor and the overall light quantum efficiency. Second, photocatalytic degradation is a typical heterogeneous catalytic process, whose reaction rate is not only controlled by photochemical steps, but more seriously limited by mass transfer process. Lignin macromolecules and intermediates produced by their degradation need to diffuse from the liquid phase to the surface of photocatalyst particles, while the final products need to be promptly desorbed and diffused back to the liquid phase. In high-viscosity reaction systems, this diffusion process is extremely slow, often becoming the rate-determining step of the entire reaction, resulting in the apparent activity of the catalyst being much lower than its intrinsic activity.

[0004] In addition, lignin and its degradation process of the viscosity of the intermediate product, easy to occur on the surface of the photocatalyst particles adsorption accumulation, resulting in catalyst deactivation. At the same time, these viscous substances are also easy to form a layer of pollution on the wall of the reactor, especially as the light window of the light transmission material surface, further hinder the light into. The catalyst particles themselves tend to agglomeration and sedimentation in the low flow area, not only reduces the effective catalytic area, serious time more will lead to reactor or pipeline blockage, forced production to stop for cleaning and maintenance, which is unacceptable for the continuous and stable operation of industrial application. Therefore, to develop a new type of reactor which can effectively overcome the above multiple obstacles such as light shielding, mass transfer limitation and pollution blockage, for promoting the practical process of lignin photocatalytic degradation technology has vital significance. SUMMARY

[0005] In view of the shortcomings of the prior art, the present application provides a continuous feeding reaction device for lignin photodegradation, which solves the problems of light shielding, easy plugging and low mass transfer efficiency caused by the viscosity and dark color of the reaction liquid in the prior art.

[0006] To achieve the above object, the present application is realized by the following technical scheme: a continuous feeding reaction device for lignin photodegradation, comprising a reaction tube; An LED light source array is arranged outside the reaction tube; A rotary drive mechanism is arranged above the reaction tube for driving the rotation of the rotating shaft inside the reaction tube; A composite scraping mechanism is installed on the rotating shaft; A transducer is arranged along the outer wall of the reaction tube; A feed pipe and a discharge pipe are fixedly connected to the top and bottom of the reaction tube, respectively, and valves are arranged on the feed pipe and the discharge pipe.

[0007] Further, when the device is running, the reaction liquid containing lignin and photocatalyst entering through the feed pipe is forced to spread into a uniform thickness liquid film on the inner wall of the reaction tube under the action of the composite scraping mechanism driven by the rotary drive mechanism. This structure significantly shortens the optical path and reduces the light shielding effect caused by the color of the reaction liquid. At the same time, the LED light source array irradiates the liquid film, and the transducer applies an ultrasonic field, which together promote the reaction to take place, and the final reaction products are discharged from the discharge pipe.

[0008] Preferably, the composite scraping mechanism comprises a mounting block fixedly connected to the outside of the rotating shaft, a connecting rod inserted into the mounting block, and a mounting rod fixedly connected between the two connecting rods, and a composite scraper mounted in the mounting block.

[0009] Further, during the rotation of the rotating shaft, the composite scraper made of porous sintered material can absorb the reaction liquid in contact with the inner wall of the reaction tube into its internal channels due to the inherent capillary action of the material. This design allows part of the reaction liquid to enter an independent micro area from the main liquid film area.

[0010] Preferably, the internal channels of the composite scraper are loaded with a second catalyst. Its technical effect is that when the reaction liquid containing the primary degradation product is absorbed into the channels, secondary catalytic conversion occurs under the action of the second catalyst. This design realizes the integration of the main reaction of photodegradation and the deep conversion of the product.

[0011] Preferably, to realize the stable connection of the components of the composite scraping mechanism, the mounting block is internally provided with a mounting groove, the connecting rod is inserted into the mounting groove, and the mounting block and the connecting rod are both provided with first threaded holes, and the first fixing screws are threadedly connected in the first threaded holes. Moreover, the mounting rod is internally provided with a clamping groove for the sliding of the composite scraper, and the mounting rod is provided with a second fixing screw for locking the composite scraper, and the second fixing screw is threadedly connected with the composite scraper through a second threaded hole.

[0012] Preferably, the rotating drive mechanism comprises a housing fixedly connected to the top of the reaction tube, a motor fixedly connected to the top of the housing, a first gear fixedly connected to the output end of the motor, a second gear fixedly connected to the top of the rotating shaft, and the first gear and the second gear are meshed with each other to transmit the driving torque.

[0013] Preferably, to ensure the overall stability of the device, a fixing ring is fixedly connected to the bottom of the reaction tube, and a support leg is fixedly connected to the bottom of the fixing ring. Moreover, a support shaft is fixedly connected inside the reaction tube, and the rotating shaft is rotationally connected through the support shaft to improve its radial stability during rotation.

[0014] Preferably, the tip of the composite scraper and the inner wall of the reaction tube maintain a pre-set gap in the range of 50 microns to 500 microns to form a liquid film of a specific thickness.

[0015] Preferably, a control system for a continuous feeding reaction device for lignin photodegradation, comprising a central control module connected to the transducer, the LED light source array and the photocatalyst array, for controlling the transducer to generate a stable ultrasonic standing wave field in the internal space of the reaction tube, driving the photocatalyst particles to form a dynamic arrangement of catalyst array, and simultaneously controlling the LED light source array to work in pulse mode, so that the trigger time of the light pulse matches the time when the density of the catalyst array reaches the peak.

[0016] The present application provides a continuous feeding reaction device for lignin photodegradation. The following advantages are provided: 1、The present application sets a composite scraping mechanism on the rotating shaft and driven by the rotating driving mechanism, which forcibly forms a thin film with controllable thickness on the inner wall of the reaction tube; the light shielding problem of dark reaction liquid is effectively overcome by shortening the optical path, and the continuous physical scraping effect of the composite scraping mechanism during rotation can effectively prevent the adhesion and accumulation of lignin and catalyst particles on the pipe wall, solving the technical problem of easy clogging of high-viscosity slurry system in continuous flow reactor, thereby ensuring long-term stable operation of the device.

[0017] 2、The present application sets a central control system to cooperatively control the transducer and the LED light source array. The central control system controls the transducer to generate an ultrasonic standing wave field, and simultaneously controls the LED light source array to work in pulse mode, realizing the concentrated transport of photon energy in time and space, improving the light quantum efficiency and total reaction rate.

[0018] 3、The composite scraper of the present application is composed of porous sintered material, which itself has the function of a microreactor; during operation, the porous structure of the composite scraper actively adsorbs the liquid in the main reaction zone through capillary action, and preloads the second catalyst in the internal pores for instant secondary catalytic conversion of the primary degradation products, realizing the integration of multi-step series reactions and simplifying the subsequent separation and purification process. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a perspective view of the present application; Figure 2 is a structural schematic view of the discharge pipe of the present application; Figure 3 is a schematic view of the rotating driving mechanism of the present application; Figure 4 is a cross-sectional schematic view of the shell of the present application; Figure 5 is a schematic view of the rotating shaft structure of the present application; Figure 6 is a cross-sectional schematic view of the reaction tube of the present application; Figure 7 is an exploded view of the fixing mechanism of the present application; Figure 8 Schematic diagram of the composite scraper of the present application.

[0020] Wherein, 1, reaction tube; 2, LED light source array; 3, motor; 4, transducer; 5, fixed ring; 6, support leg; 7, valve; 8, discharge pipe; 9, feed pipe; 10, shell; 11, rotating shaft; 12, first gear; 13, second gear; 14, mounting block; 15, connecting rod; 16, mounting rod; 17, composite scraper; 18, support shaft; 19, mounting groove; 20, first threaded hole; 21, first fixed screw; 22, second fixed screw; 23, second threaded hole; 24, clamping groove. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the specification of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0022] Embodiment: Please refer to the drawings in the specification of the present application Figure 1 - the drawings Figure 8 The embodiment of the present application provides a continuous feeding reaction device for lignin photodegradation, which comprises a reaction tube 1. The reaction tube 1 is the core unit of the reaction device and is in a cylindrical structure and transparent in material. Its axis is perpendicular to the horizontal plane during use. On the outside of the reaction tube 1, an LED light source array 2 for providing light energy and a transducer 4 for applying sound energy are arranged along the circumferential direction and the axial direction. Above the reaction tube 1, a rotating driving mechanism is arranged for providing power for the rotating components inside the reactor. Below the reaction tube 1, a support structure is arranged to stably support the device. Inside the reaction tube 1, a rotating shaft 11 is arranged along the geometric center axis of the reaction tube 1. At least one composite scraping mechanism is mounted on the rotating shaft 11 along the length direction thereof. When the composite scraping mechanism rotates on the rotating shaft 11, the composite scraper 17 at the end thereof acts with the inner wall of the reaction tube 1 to realize the treatment of the liquid flowing through the pipe wall. The material conveying system of the reaction device is composed of a feed pipe 9 located at the top of the reaction tube 1 and a discharge pipe 8 located at the bottom thereof, forming a continuous flow path from top to bottom. Valves 7 are arranged on the feed pipe 9 and the discharge pipe 8 for controlling the on-off and flow regulation of the material flow.

[0023] In addition, the reaction device also includes a central control module. This central control module is electrically connected to the rotary drive mechanism, the LED light source array 2, and the transducer 4, and is used to coordinate and control the operating parameters of each mechanism and component, such as rotational speed, light intensity and mode, ultrasonic frequency and power, and their working sequence in a unified and coordinated manner.

[0024] Please see the appendix Figure 1 Appendix Figure 2 and attached Figure 6 The reaction tube 1 and its supporting structure are described in detail below. The reaction tube 1 is made of high-transmittance quartz glass to minimize light energy absorption loss through the tube wall, ensuring that photons generated by the external LED light source array 2 can efficiently reach the reaction region. In this embodiment, ultraviolet fused silica glass is selected. This material has a light transmittance of over 90% in the commonly used photocatalytic wavelength range of 250 nm to 450 nm, perfectly matching the intrinsic absorption band of common wide-bandgap semiconductor photocatalysts. To obtain ideal liquid film flow characteristics, the inner wall of the reaction tube 1 is chemically and mechanically polished, and its surface roughness is controlled to less than 0.4 micrometers. This effectively reduces the flow resistance of the high-viscosity liquid film on the tube wall and reduces the mechanical wear of the composite scraper 17. As a more cost-effective alternative, the reaction tube 1 can also be made of borosilicate glass. Although its transmittance in the deep ultraviolet region is slightly lower than that of quartz glass, its performance fully meets the requirements for visible light responsive photocatalyst systems. The dimensions of reaction tube 1 can be customized according to the target throughput and the residence time required by the process. Its inner diameter can be selected from 50 mm to 200 mm, and the length of the effective reaction zone can be selected from 500 mm to 2000 mm.

[0025] To ensure the overall mechanical stability and installation accuracy of the device, a stainless steel retaining ring 5 is fixedly connected to the bottom outer side of the reaction tube 1 via a flange connection. Multiple ring-shaped support legs 6 are welded to the bottom of the retaining ring 5. The retaining ring 5 and support legs 6 together form an integrated base. Anchor bolt holes are pre-drilled on the base to firmly fix the entire device to the factory floor foundation. The verticality of the reaction tube 1 can be precisely calibrated by adjusting the leveling nuts on the anchor bolts to ensure the liquid film falls evenly under gravity. A flexible, shaped silicone rubber gasket is filled between the inner ring of the retaining ring 5 and the outer wall of the reaction tube 1. The elastic gasket absorbs vibrations transmitted from the motor 3 or the external environment, compensates for the different thermal expansion amounts between the quartz glass and stainless steel due to temperature changes, and provides reliable sealing and cushioning support to the bottom of the reaction tube 1.

[0026] To further improve the operational stability of the large aspect ratio rotating shaft 11 under high-speed rotation conditions and suppress its potential flexural deformation and radial vibration, a support shaft 18 is fixedly connected inside the reaction tube 1, serving as a guide and support. In this embodiment, the support shaft 18 is a hollow tubular structure, with its lower end fixed to the bottom of the inner wall of the reaction tube 1 and its upper end used to support the rotation of the rotating shaft 11. This bottom-center support structure provides a stable support point for the rotating shaft 11, greatly improving the stiffness and critical speed of the rotating shaft 11, thereby ensuring that the preset gap between the tip of the composite scraper 17 and the inner wall of the reaction tube 1 remains constant throughout the entire operation.

[0027] Please see the appendix Figure 3 and attached Figure 4 The rotary drive mechanism is described in detail below. The rotary drive mechanism is integrated into the upper end of the reaction tube 1 and includes a housing 10, which is fixedly connected to the top of the reaction tube 1. In this embodiment, the housing 10 is a sealed box made of stainless steel, with a standard mounting flange on its top for docking with the mounting flange of the motor 3; the bottom is tightly connected to the top of the reaction tube 1 via high-strength bolts and a corrosion-resistant PTFE gasket, thus forming a clean space completely isolated from the outside atmosphere to house the transmission components.

[0028] Motor 3 is fixedly mounted on the top of housing 10, with its power output shaft pointing vertically downwards. In this embodiment, a servo motor 3 with precise speed and position control capabilities is selected as the power source to enable wide-range stepless speed regulation and programmed control of the rotational speed of shaft 11 via a central control module. A first gear 12 is fixedly connected to the output shaft of motor 3, and the top end of shaft 11 extends through the bottom of housing 10 and is also fixedly connected to a second gear 13. The first gear 12 and the second gear 13 mesh with each other, forming a single-stage speed-reducing and torque-increasing transmission chain. When motor 3 operates, its output rotational motion and torque are stably transmitted to shaft 11 through this gear set, driving its rotation. The transmission ratio of the gear set is precisely calculated and designed based on the rated speed of motor 3 and the required speed range for the process. To ensure absolute sealing of the reaction system, a high-performance dynamic sealing device is installed at the location where shaft 11 passes through the bottom plate of housing 10. In this embodiment, a magnetohydrodynamic seal or a cartridge-type double-end mechanical seal is used. This type of seal can achieve zero leakage under high speed and certain pressure, effectively preventing the leakage of reactants or the entry of outside air into the reaction system, thus ensuring the safety and purity of the reaction process.

[0029] Please see the appendix Figure 5 To be continued Figure 8The detailed structure of the composite scraping mechanism is described below. This mechanism is a key component for realizing the core function of this invention. The composite scraping mechanism includes a mounting block 14 fixed to the outside of the rotating shaft 11. The mounting block 14 is firmly fixed to the rotating shaft 11 by welding to ensure reliable transmission of the large torque generated by the rotary drive mechanism. A mounting groove 19 is radially formed inside the mounting block 14. One end of the connecting rod 15 is machined to match the shape of the mounting groove 19 and inserted into the inside of the mounting groove 19. To achieve a secure lock, both the mounting block 14 and the connecting rod 15 have mutually aligned first threaded holes 20. By screwing the first fixing screw 21 into the first threaded hole 20, the connecting rod 15 can be locked onto the mounting block 14.

[0030] The other ends of the two connecting rods 15 are fixedly connected to a mounting rod 16 by welding. A composite scraper 17 is installed inside the mounting rod 16. A slot 24 is provided inside the mounting rod 16 to accommodate and guide the composite scraper 17, allowing one side of the composite scraper 17 to slide radially within the slot 24. To fix the position of the composite scraper 17, second threaded holes 23 are provided at corresponding positions on both the mounting rod 16 and the composite scraper 17. By screwing in and tightening the second fixing screw 22, the composite scraper 17 can be locked in the desired working position. This adjustable connection structure ensures that the tip of the composite scraper 17 remains within a preset micro-gap to the inner wall of the reaction tube 1. This gap is a key parameter for forming a liquid film of a specific thickness, and its actual range is typically between 50 and 500 micrometers. The mounting block 14, connecting rods 15, and mounting rod 16 are all made of 316L stainless steel with excellent corrosion resistance to withstand acidic or alkaline environments that may be encountered during lignin degradation.

[0031] The blade shape of the composite scraper 17 is optimized for hydrodynamics. Its side facing the direction of rotation is a smooth curved surface, which facilitates the smooth and undisturbed spreading of falling liquid into a film. Its tip is machined into a wedge shape to achieve efficient film scraping with minimal contact area and shear force. In another embodiment, one or more compression springs can be provided between the back of the composite scraper 17 and the bottom of the slot 24, allowing the composite scraper 17 to elastically conform to the inner wall of the reaction tube 1. This automatically compensates for minor non-roundness of the tube wall caused by processing errors and normal wear of the scraper during use, ensuring long-term consistency of the liquid film thickness.

[0032] In this embodiment, the main body of the composite scraper 17 is composed of a porous sintered material with a specific and uniform pore size distribution. When the rotating shaft 11 drives the composite scraper 17 to rotate at high speed on the inner wall of the reaction tube 1, due to the inherent and strong capillary action of the porous sintered material, the composite scraper 17, which is in continuous contact with the liquid film on the tube wall, will actively and continuously draw a portion of the reaction liquid into its internal micron-scale pore network. In this embodiment, the composite scraper 17 can be made of sintered stainless steel fiber felt or sintered titanium powder porous plate with an average pore size of 5 micrometers and a porosity of 35%. Its capillary adsorption capacity is closely related to the wettability of the material, the pore size, and the surface tension of the reaction liquid. By performing plasma treatment or chemical grafting modification on the sintered material, its surface energy can be actively adjusted to precisely match the reaction liquid of different solvent systems, thereby achieving optimized control of the adsorption rate and adsorption amount.

[0033] Furthermore, during the manufacturing of the composite scraper 17, a second catalyst is pre-loaded into the internal channels of the composite scraper 17 using a specific process. Thus, when the reaction liquid containing the initial photodegradation products is drawn into the channels, it will come into full contact with the second catalyst within this microscopic space, resulting in an immediate secondary catalytic transformation. This structural design ingeniously achieves a high degree of integration between the main photodegradation reaction and the deep product transformation tandem reaction within a single device. The loading process of the second catalyst can employ a mature wet chemical method. The porous scraper substrate is immersed in a solution containing the precursor of the second catalyst. Vacuum-assisted impregnation ensures that the solution completely penetrates deep into the pore network. Then, it is slowly dried to uniformly disperse the precursor. Finally, it is calcined under specific gas and temperature conditions to decompose the precursor in situ and transform it into highly catalytically active metal or metal oxide nanoparticles, which are then firmly immobilized on the inner wall of the channels.

[0034] The core of this invention's highly efficient photocatalysis lies in its acoustic-optical synergistic mechanism, which is precisely controlled by a central control system. First, the central control module controls an array of transducers 4 arranged in an array along the outer wall of the reaction tube 1, causing them to emit ultrasonic waves of a specific frequency and phase. In this embodiment, the transducers 4 are piezoelectric ceramic transducers, with continuously adjustable operating frequencies ranging from 0.5 MHz to 5 MHz. Multiple transducer units are closely arranged along the circumference and axial direction of the reaction tube 1, forming a multi-channel ultrasonic phased array. The central control module provides each transducer unit with a radio frequency drive signal whose phase and amplitude can be precisely controlled through a multi-channel signal generator and an independent power amplifier. By setting a specific phase difference for adjacent transducer units, a stable ultrasonic standing wave field can be formed by interference in the radial or circumferential dimensions of the thin liquid film inside the tube. In this standing wave field, the photocatalyst particles suspended in the liquid are subjected to acoustic radiation forces, the magnitude of which is related to the acoustic characteristics of the particles and the medium, the particle size, and the sound pressure gradient. By selecting appropriate ultrasonic frequencies and power, photocatalyst particles within a specific size range can be efficiently captured and organized, overcoming fluid drag and Brownian motion, and directionally migrating towards the nodes or antinodes of the standing wave field. This results in the formation of a series of periodically arranged dynamic catalyst arrays with extremely high local catalyst concentrations in the originally uniformly dispersed liquid film.

[0035] Simultaneously with the formation of the catalyst array, the central control module executes the acoustic-optical synchronization control logic, controlling the LED light source array 2 to output illumination in pulse mode. The LED light source array 2 is composed of multiple high-power deep ultraviolet LED chips densely packaged and arranged in a ring array close to the outer wall of the reaction tube 1, equipped with a heat dissipation system. The core processor in the central control module is responsible for performing this microsecond-level high-precision synchronization task. After the start of an ultrasonic cycle, the control system precisely triggers the drive circuit to generate a short, high-intensity light pulse. The width of the light pulse is designed to be much smaller than the ultrasonic cycle to ensure that the catalyst array is in a quasi-static, highest-density state during illumination. The repetition frequency of the light pulse is the same as the ultrasonic frequency. This synchronization mechanism ensures that precious photon energy is concentrated and delivered to the reaction region at the moment of highest catalyst particle density and in the most concentrated space, thereby greatly improving the efficiency of light energy utilization and the photon yield.

[0036] Working Principle: First, preparation work is carried out. Valves 7 on the inlet pipe 9 and outlet pipe 8 are opened, and the reactants, pre-prepared in the mixing tank, are continuously and stably pumped into the top of the reaction pipe 1 via the inlet pipe 9 using an external precision metering pump. The reactants are formed in the mixing tank by thoroughly mixing and dispersing quantitative amounts of lignin powder and photocatalyst powder in a specific solvent using a high-shear dispersing emulsifier to form a uniform and stable suspension. The metering pump is preferably a pulsation-free screw pump or peristaltic pump to achieve precise flow rate adjustment. The flow rate setpoint is calculated based on the average residence time and throughput required by the process.

[0037] Subsequently, the reaction process is initiated. The rotary drive mechanism is activated, and the servo motor 3 drives the rotating shaft 11 and the composite scraping mechanism mounted on it to rotate at a set speed through gear transmission. The material continuously falling from the feed pipe 9 flows towards the pipe wall under the combined action of gravity and centrifugal force, and is immediately forcibly scraped and spread on the inner wall of the reaction tube 1 by the high-speed rotating composite scraper 17, forming a turbulent liquid film with uniform thickness and continuously renewed surface. The actual thickness of the liquid film is determined by the scraper gap, rotation speed, liquid viscosity, and feed flow rate. By coordinating the adjustment of these parameters, the liquid film thickness can be stably controlled within the range of 50 to 500 micrometers. Such a thin liquid film greatly shortens the optical path, allowing even dark brown lignin solutions to achieve complete light penetration, thus fundamentally solving the serious light shielding problem existing in traditional reactors. Meanwhile, the powerful centrifugal force generated by high-speed rotation and the continuous shearing action of the scraper on the liquid film create strong micro-turbulence inside the liquid film, which greatly enhances the mass transfer of reactant molecules to the catalyst surface and the desorption of product molecules from the catalyst surface, effectively breaking through the mass transfer bottleneck.

[0038] Next, the acoustic-optical synergistic enhancement step is initiated. The central control system is activated, and transducer 4 and LED light source array 2 begin operating according to the preset acoustic-optical synergistic program. Transducer 4 generates an ultrasonic standing wave field, organizing the photocatalyst particles in the liquid film into a high-density array; simultaneously, LED light source array 2 emits pulsed light synchronized with the catalyst array, enabling a highly efficient photocatalytic reaction in the liquid film. Throughout the reaction process, in addition to fulfilling its core dynamic film-forming function, composite scraper 17 continuously physically scrapes the inner wall of reaction tube 1, effectively preventing the formation of a contamination layer on the tube wall by sticky lignin or its degradation products, achieving self-cleaning of the light window, and ensuring long-term stability of light energy input. Simultaneously, its porous structure also synchronously adsorbs liquid, and under the action of the internally loaded second catalyst, performs immediate secondary catalytic transformation of the initial degradation products.

[0039] Finally, the product is discharged. After remaining in the reactor for a predetermined time, the reacted liquid flows continuously along the tube wall to the bottom of reaction tube 1 under gravity, and is then continuously discharged through discharge pipe 8 to the subsequent separation and purification unit for product separation and recovery. The entire process achieves efficient and continuous photocatalytic degradation of lignin.

Claims

1. A continuous feed reaction apparatus for lignin photodegradation, characterized by, The utility model relates to a kind of reaction tube and its rotating mechanism, including, Reaction tube (1); LED light source array (2), the LED light source array (2) is arranged outside the reaction tube (1); Rotary drive mechanism, the rotary drive mechanism is arranged above the reaction tube (1), for driving rotating shaft (11) inside reaction tube (1) rotation; Composite scraping mechanism, the composite scraping mechanism is installed on the rotating shaft (11); Transducer (4), the transducer (4) is arranged along the reaction tube (1) outer wall; Feed pipe (9) and discharge pipe (8), the feed pipe (9) is fixedly connected at the top of the reaction tube (1), the discharge pipe (8) is fixedly connected at the bottom of the reaction tube (1), and the feed pipe (9) and discharge pipe (8) are both provided with valve (7).

2. A continuous feed reaction apparatus for the photodegradation of lignin according to claim 1, characterized in that, The composite scraping mechanism includes mounting block (14), the mounting block (14) is fixedly connected outside the rotating shaft (11), the mounting block (14) is inserted with connecting rod (15) inside, one mounting rod (16) is fixedly connected between two connecting rods (15), composite scraper (17) is installed in the mounting rod (16), the composite scraper (17) is made of porous sintered material, for being absorbed into its internal hole by capillary action when the rotating shaft (11) rotates, reaction liquid.

3. A continuous feed reaction apparatus for the photodegradation of lignin according to claim 2, characterized in that, The internal hole of the composite scraper (17) is loaded with catalyst, for the secondary catalytic conversion of the preliminary degradation product in the absorbed reaction liquid.

4. A continuous feed reaction apparatus for lignin photodegradation according to claim 2, characterized by, The mounting block (14) is provided with mounting groove (19) inside, the connecting rod (15) is inserted into the mounting groove (19), and the mounting block (14) and the connecting rod (15) are both provided with first threaded hole (20), the first threaded hole (20) is screwed with first fixing screw (21) inside.

5. A continuous feed reaction apparatus for the photodegradation of lignin according to claim 4, characterized in that, The mounting rod (16) is provided with clamping groove (24) inside, the composite scraper (17) is slidably connected in the clamping groove (24), and the mounting rod (16) and the composite scraper (17) are both provided with second threaded hole (23), the second threaded hole (23) is screwed with second fixing screw (22) inside.

6. A continuous feed reaction apparatus for lignin photodegradation according to claim 1, characterized by, The rotary drive mechanism includes shell (10), the shell (10) is fixedly connected at the top of the reaction tube (1), the shell (10) top is fixedly connected with motor (3), the motor (3) output end is fixedly connected with first gear (12), the rotating shaft (11) top is fixedly connected with second gear (13), and the first gear (12) and the second gear (13) are engaged with each other.

7. A continuous feed reaction apparatus for photodegradation of lignin according to claim 1, characterized by, The reaction tube (1) bottom outside is fixedly connected with fixed ring (5), and the fixed ring (5) bottom is fixedly connected with support leg (6).

8. A continuous feed reaction apparatus for photodegradation of lignin according to claim 1, characterized by, The reaction tube (1) is fixedly connected with support shaft (18) inside, and the rotating shaft (11) is rotatably connected in the support shaft (18).

9. A continuous feed reaction apparatus for photodegradation of lignin according to claim 2, characterized by, The tip of the composite scraper (17) and the inner wall of the reaction tube (1) keep the range of preset gap between 50 microns and 500 microns.

10. A control system for a continuous feed reaction apparatus for lignin photodegradation, characterized by, A continuous feeding reaction device for lignin photodegradation according to any one of claims 1-9, comprising a central control module electrically connected with the LED light source array (2), the motor (3) and the transducer (4) for controlling the (4) to generate a stable ultrasonic standing wave field in the internal space of the (1), driving the photocatalyst particles to form a dynamic arrangement of catalyst array, and at the same time controlling the (2) to work in pulse mode, so that the trigger time of the light pulse matches the time when the density of the catalyst array reaches the peak.

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