Fluidized bed dielectric barrier discharge reactor, system and method

Abstract

The embodiment of the invention discloses a fluidized bed dielectric barrier discharge reactor, system and method, and relates to the technical field of plasma synthesis ammonia, the reactor comprises an inner electrode tail end and a dielectric barrier tube bottom which are provided with mutually matched curved surface structures, the structure generates a non-uniform electric field when working voltage is applied, and the inner electrode tail end and the dielectric barrier tube bottom are connected with each other. Dielectrophoretic force is generated on catalyst particles, and the particles are driven to form a fluidized state. The system also comprises a controllable power supply system which is used for adjusting the amplitude and frequency of the working voltage so as to adjust the size of the dielectrophoretic force. The method of the present application includes applying a voltage to fluidize the catalyst and adjusting the voltage or frequency to match the fluidization state to the reactor load. Dynamic fluidization of the catalyst is achieved through dielectrophoretic force, effective contact is increased, discharge uniformity is improved, reaction efficiency is improved, and accurate regulation and control of the fluidization state can be achieved.

Description

Technical Field

[0001] This invention relates to the field of plasma ammonia synthesis technology, and more particularly to a fluidized bed medium barrier discharge reactor. Background Technology

[0002] In recent years, plasma technology has shown great potential in the field of ammonia synthesis. Among them, dielectric barrier discharge (DBD) has received widespread attention in plasma ammonia synthesis research due to its advantages such as simple structure, convenient operation, uniform discharge, and easy coupling with catalysts.

[0003] In plasma-coupled catalyst ammonia synthesis systems, there are typically two interaction modes between the plasma and the catalyst. One mode involves the catalyst being downstream of the plasma; the gas passes through the plasma region before flowing through the catalyst bed to synthesize ammonia. Therefore, the plasma and catalyst are physically separated, a mode known as post-plasma catalysis. While this mode achieves some degree of plasma-catalyst coupling, it also presents several significant problems: highly reactive substances generated in the plasma (such as electrons, ions, and short-lived free radicals) have already decayed or deactivated before reaching the catalyst, leaving only long-lived free radicals to interact with it, which greatly limits catalytic efficiency. Furthermore, the temperature difference between the plasma and catalyst regions can inhibit the thermodynamic equilibrium reaction. The other mode places the catalyst in the discharge region and allows it to directly contact the plasma, achieving immediate synergistic effects between the plasma and catalyst, a mode known as intra-plasma catalysis. In this mode, the theoretical contact area between the plasma and catalyst is large, allowing the plasma to effectively act on the catalyst. Currently, catalyst particles are typically placed directly on the DBD discharge region or coated onto the surface of electrodes or dielectric barrier layers to achieve in-plasma catalysis. While this method increases the contact area, the catalyst particles are prone to compact packing and uneven distribution due to gravity or airflow. This results in some catalysts failing to fully contact the plasma and can also cause electric field distortion in the discharge region, concentrating discharge energy in the gaps between particles or on surface protrusions, forming "micro-discharge hotspots" that affect overall catalytic performance. Therefore, overcoming the static packing of catalysts and achieving uniform and dynamic dispersion within the plasma discharge region is a key technological bottleneck for improving the performance of dielectric barrier discharge catalytic systems. Summary of the Invention

[0004] The main objective of this invention is to provide a fluidized bed medium barrier discharge reactor, system, and method, which aims to solve the technical problems of insufficient contact with plasma, uneven discharge, and low reaction efficiency caused by the static accumulation of catalyst particles.

[0005] To achieve the above objectives, this application provides a fluidized bed medium barrier discharge reactor, comprising:

[0006] A dielectric barrier tube defining a reaction chamber; catalyst particles disposed within the reaction chamber; an inner electrode and an outer electrode disposed inside and outside the dielectric barrier tube, respectively; and a gas inlet for introducing reaction gas into the reaction chamber;

[0007] in:

[0008] The end of the inner electrode and the bottom of the dielectric barrier tube have mutually compatible curved surface structures.

[0009] The mutually adapted curved structure is used to generate a non-uniform electric field in the bottom region of the reaction chamber when a working voltage is applied between the inner and outer electrodes. The non-uniform electric field generates a dielectric force on the catalyst particles placed therein, thereby driving the catalyst particles to form a fluidized state in the reaction chamber.

[0010] This application also provides a fluidized bed dielectric barrier discharge system, including a fluidized bed dielectric barrier discharge reactor as described in the first aspect; and a power supply system for supplying power to the reactor;

[0011] The power supply system includes a frequency and voltage regulation module and a control unit;

[0012] The control unit is used to adjust the output of the frequency and voltage modulation module to control the voltage amplitude and frequency of the working voltage applied to the inner and outer electrodes, thereby adjusting the magnitude of the dielectric force.

[0013] This application, in another aspect, provides a method for achieving catalyst fluidization, said method being applied to a fluidized bed dielectric barrier discharge system as described in the second aspect; the method includes:

[0014] The reaction gas is introduced into the reaction chamber containing catalyst particles;

[0015] A working voltage is applied to the inner and outer electrodes via the power system to generate a non-uniform electric field using the mutually adapted curved surface structure, thereby applying dielectric force to the catalyst particles and fluidizing them; and

[0016] The voltage amplitude or frequency of the operating voltage is adjusted by the control unit to change the magnitude of the dielectric force, thereby matching the fluidization state of the catalyst particles with the reactor load.

[0017] The technical solution provided in this application has the following beneficial effects:

[0018] Dynamic fluidization of the catalyst through dielectric electrophoresis greatly increases the effective contact area and contact time between the catalyst and the plasma, enabling all catalyst particles to participate effectively in the reaction, thereby significantly improving the conversion rate and yield of the chemical reaction. At the same time, the dynamic suspension of catalyst particles avoids electric field distortion and local hot spots caused by static accumulation, making the discharge more uniform and dispersed throughout the reaction region, improving energy utilization efficiency, and enhancing the stability of system operation. In addition, by precisely controlling the power supply parameters, the fluidization state of the catalyst can be actively and flexibly controlled to match different reactor loads and process requirements, providing a reliable means to optimize reaction conditions and achieve optimal catalytic performance. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] in:

[0021] Figure 1 This is a schematic diagram of the architecture of a fluidized bed dielectric barrier discharge system provided in an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of the structure of a fluidized bed medium barrier discharge reactor provided in an embodiment of this application;

[0023] Figure 3 This is a three-dimensional schematic diagram of an internal electrode used in a reactor, provided as an embodiment of this application.

[0024] Figure 4 An equivalent circuit diagram of a fluidized bed DBD system based on electrohydraulic effects is provided in an embodiment of this application;

[0025] Figure 5 This is a schematic flowchart illustrating a method for achieving catalyst fluidization provided in an embodiment of this application.

[0026] Figure 6 This is a schematic flowchart illustrating another method for achieving catalyst fluidization provided in an embodiment of this application. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0028] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] The embodiments of this application are described below with reference to the accompanying drawings.

[0031] Please see Figure 2 This is a schematic diagram of the structure of a fluidized bed medium barrier discharge reactor provided in an embodiment of this application. Figure 3 This is a three-dimensional schematic diagram of the internal electrode 1 used in the reactor.

[0032] Specifically, the fluidized bed dielectric barrier discharge reactor includes an inner electrode 1, a ceramic insulating plug 2, catalyst powder 3, a quartz dielectric tube 4, and an outer electrode 5.

[0033] The quartz dielectric tube 4, serving as the main container of the reactor, is made of high-purity quartz glass. This material possesses excellent dielectric properties, high-temperature resistance, and chemical stability, enabling it to withstand the high temperatures and chemical corrosion under plasma discharge conditions. The quartz dielectric tube 4 is cylindrical, defining a reaction chamber within it for the chemical reaction. It should be noted that the bottom of the quartz dielectric tube 4 is not flat but designed as a smooth hemispherical bottom. This curved structure is used to create a specific non-uniform electric field with the internal electrodes.

[0034] The inner electrode 1 is disposed inside the quartz dielectric tube 4 and extends longitudinally along its central axis. For example... Figure 3 As shown, in one embodiment of this application, the inner electrode 1 is preferably made of Hastelloy C276 material. This nickel-based corrosion-resistant alloy has excellent resistance to corrosive gases that may be present in the reaction environment such as plasma ammonia synthesis, thereby ensuring the long-term stable operation of the electrode. The structure of the inner electrode 1 may include two parts: a hollow tubular body and a porous spherical end. The upper end of the hollow tubular body extends to the outside of the reactor, and its internal channel constitutes a gas inlet 8 for introducing reaction gas from an external gas source. The porous spherical end is located at the lower end of the inner electrode 1, and its outer surface is a smooth sphere. The spherical curved surface of the porous spherical end and the hemispherical bottom of the quartz dielectric tube 4 have a mutually compatible geometric relationship. Specifically, the porous spherical end and the hemispherical bottom are coaxially arranged, and the gap between them remains uniform. As a preferred implementation, to ensure the accuracy of the electric field distribution, the coaxiality error between the two is strictly controlled within 0.05 mm. The surface of the porous spherical end is also uniformly distributed with a large number of micropores. These micropores are connected to the internal channels of the hollow tubular body of the inner electrode 1, so that the reaction gas entering from the gas inlet 8 can be uniformly sprayed from the porous spherical end to the bottom region of the reaction chamber.

[0035] The external electrode 5 is disposed on the outside of the quartz dielectric tube 4. In this embodiment, the external electrode 5 adopts a metal mesh structure, such as stainless steel mesh or copper mesh, whose shape matches the outer contour of the quartz dielectric tube 4, and tightly wraps and adheres to the lower half of the outer wall of the quartz dielectric tube 4, especially covering the outer area corresponding to the hemispherical bottom. This mesh structure ensures good conductivity and facilitates observation of the internal condition of the reaction chamber. Accordingly, the inner electrode 1 and the external electrode 5 together constitute the electrode pair that generates dielectric barrier discharge.

[0036] Catalyst powder 3 (also referred to as catalyst particles) is pre-placed at the bottom of the reaction chamber, specifically in the annular space between the porous spherical end 1a of the inner electrode 1 and the hemispherical bottom 4a of the quartz dielectric tube 4. These catalyst particles are crucial for achieving specific chemical reactions (such as ammonia synthesis). Without an applied electric field or gas flow, the catalyst powder 3 statically accumulates at the bottom of the reaction chamber due to gravity.

[0037] To achieve precise positioning of the inner electrode 1, sealing of the reaction chamber, and separation of products, the reactor also includes a ceramic insulating plug 2. This ceramic insulating plug 2 is located in the upper part of the reaction chamber and is made of high-temperature insulating ceramics such as alumina, and has a special partitioned functional structure. Its central part is a solid structure with a central through-hole precisely fitted to the outer diameter of the hollow tubular body of the inner electrode 1, used to securely clamp and fix the inner electrode 1, ensuring its positional stability and coaxiality. The outer wall of the ceramic insulating plug 2 is tightly fitted to the inner wall of the quartz dielectric tube 4, and the reaction chamber is effectively sealed through auxiliary structures such as sealing rings to prevent gas leakage. In the annular region between the central fixed area and the outer wall, numerous through-holes are machined. The diameter of these through-holes is carefully designed to allow gas molecules generated after the reaction to pass through smoothly, but is much smaller than the particle diameter of the catalyst powder 3, thus effectively preventing the catalyst powder 3 from being carried away from the reaction zone by airflow or dielectric force, preventing catalyst loss. The gas passing through the ceramic insulating plug 2 is finally discharged from the outlet 7 located above it.

[0038] In addition, to precisely control the reaction temperature, a liquid constant-temperature heating device 6 can be installed outside the reactor. This device can be a constant-temperature oil bath or water bath jacket, which heats or cools the quartz dielectric tube 4 by circulating liquid at a specific temperature, thereby precisely maintaining the temperature inside the reaction chamber at the set value required by the process. For reactions such as plasma-catalyzed ammonia synthesis, a preferred temperature range is 200°C to 300°C, within which the synergistic effect of the catalyst and the plasma can achieve better results.

[0039] The working process of the reactor described in this embodiment may include the following steps:

[0040] First, an appropriate amount of catalyst powder 3 is loaded into the bottom of the reaction chamber. Then, nitrogen and hydrogen are mixed in a specific ratio and used as the reaction gas. This mixture is introduced into the hollow tubular body 1b of the inner electrode 1 through the gas inlet 8. The gas flows downwards along the internal channel and is finally uniformly ejected from the micropores of the porous spherical end 1a, entering the area where the catalyst powder 3 is located. Simultaneously, the liquid constant-temperature heating device 6 is activated to heat and stabilize the temperature of the reaction chamber at, for example, 250°C.

[0041] After the above preparations are completed, a working voltage is applied between the inner electrode 1 and the outer electrode 5 using a high-frequency, high-voltage AC power supply (described in detail in Example 4). A preferred voltage parameter range is: a voltage amplitude of 8 kV to 12 kV and a frequency of 5 kHz to 7 kHz. After applying this working voltage, the porous spherical end of the inner electrode 1 and the hemispherical bottom of the quartz dielectric tube 4 form a mutually compatible curved surface structure, which, together with the outer electrode 5, generates a highly non-uniform electric field in the bottom region of the reaction chamber. The electric field lines radiate outwards from the surface of the spherical inner electrode, with the electric field strength reaching its maximum near the surface of the porous spherical end 1a of the inner electrode 1, and rapidly decreasing with distance from this surface, forming a significant electric field strength gradient.

[0042] The catalyst powder 3, placed in this non-uniform electric field, as a polarizable dielectric particle, is subjected to a volume force called dielectric force. The magnitude of the dielectric force is proportional to the dielectric properties of the particle, the square of the electric field strength, and the gradient of the electric field strength. Under the specific structure and electric field conditions of this application, the dielectric force manifests as a force pointing towards the region with a stronger electric field (i.e., towards the porous spherical end of the inner electrode 1), as well as a complex, frequency-dependent tumbling and levitation force. By precisely adjusting the amplitude and frequency of the working voltage, the magnitude of the dielectric force can be actively and controllably changed. When the dielectric force works synergistically with the drag force generated by the gas ejected from the bottom, and the resultant force is sufficient to overcome the gravity of the catalyst particles themselves and the van der Waals forces between the particles due to electrostatics, moisture, etc., the originally statically packed catalyst powder 3 will detach from the bottom and begin to violently tumble, jump, and suspend in the reaction chamber, forming a macroscopically uniformly distributed dynamic fluidized state.

[0043] In this fluidized state, each catalyst particle has ample opportunity to come into close contact with the large number of high-energy electrons, ions, free radicals, and other active species (i.e., plasma) generated by the dielectric barrier discharge within the reaction chamber. This significantly increases the effective contact area and interaction time between the plasma and the catalyst, overcoming the shortcomings of static beds where only surface particles participate in the reaction. Simultaneously, the dynamic movement of the particles avoids localized electric field concentration and hotspot formation, making the micro-discharge more diffuse and uniform throughout the discharge region, thus improving energy utilization efficiency. The reaction products (e.g., ammonia) mix with the unreacted gas and flow upwards, passing through the porous region of the ceramic insulating plug 2, and finally exiting from the outlet 7 for subsequent collection and analysis.

[0044] Based on the aforementioned reactor structure, this application also proposes a fluidized bed dielectric barrier discharge system.

[0045] Figure 1 This is a schematic diagram of the architecture of a fluidized bed dielectric barrier discharge system provided in an embodiment of this application.

[0046] like Figure 1 As shown, the fluidized bed dielectric barrier discharge system 100 of this embodiment may include, as shown in the figure, Figure 2 The fluidized bed medium barrier discharge reactor 200 shown, and the power supply system for powering it.

[0047] The reactor can be any type of reactor, but their common core feature is that they have mutually adapted curved electrode structures that can generate non-uniform electric fields.

[0048] The aforementioned power supply system is a key component for achieving precise control of dielectric force. It is designed as a modular system, mainly comprising: an input processing and rectification module 110, a frequency and voltage regulation module 120, a feedback and protection module 130, and a control unit 140.

[0049] The input processing and rectification module 110 is used to receive AC power (e.g., 220V / 50Hz) from the mains or industrial power grid, and to filter, rectify and regulate it to convert it into stable high-voltage DC power to provide energy for subsequent applications.

[0050] The frequency and voltage regulation module 120 typically consists of a full-bridge or half-bridge inverter circuit (e.g., using insulated-gate bipolar transistors or metal-oxide-semiconductor field-effect transistors as switching elements) and a high-frequency step-up transformer. This module receives DC power from module 110 and, driven by control signals from control unit 140, inverts it into high-frequency, high-voltage AC power with adjustable frequency and voltage through high-frequency switching operation, outputting it to the inner and outer electrodes of the reactor.

[0051] The feedback and protection module 130 monitors the voltage applied to the reactor and the current flowing through the circuit in real time using a high-voltage probe and a current sensor, and feeds these signals back to the control unit 140. Simultaneously, this module also has overvoltage, overcurrent, and overheat protection functions; once an abnormal operating condition is detected, it can immediately cut off the output to protect the power supply and the reactor.

[0052] The control unit 140 is the core control component of the entire power system, typically implemented by a microcontroller or digital signal processor. It receives instructions from the user (e.g., target voltage and frequency set via a touchscreen or host computer software) and, based on real-time electrical parameters fed back from the feedback and protection module 130, dynamically adjusts the duty cycle and frequency of the pulse width modulation signal sent to the frequency and voltage modulation module 120 by executing a preset control algorithm (such as a proportional-integral-derivative control algorithm). Through this closed-loop control method, the control unit 140 ensures that the amplitude and frequency of the operating voltage output to the reactor are precisely stabilized at the set values, thereby achieving precise and dynamic adjustment of the dielectric force.

[0053] Figure 4 An equivalent circuit diagram of a fluidized bed DBD system based on electrohydraulic effects is provided for an embodiment of this application.

[0054] like Figure 4 The diagram illustrates the complete power conversion and control chain from AC mains input to discharge in a fluidized bed dielectric barrier discharge (DBD) reactor. Its core function is to convert AC mains power into a stable and safe high-voltage AC output with adjustable frequency and voltage to drive the DBD reactor. The system consists of the following main modules:

[0055] Rectifier module: Receives external AC input, filters and rectifies it to provide DC power to the system.

[0056] Inverter module: Includes full-bridge inverter and LC filter, converting DC power into frequency- and voltage-adjustable AC power for use in the DBD reactor. The high-frequency square wave after inversion is filtered by LC low-pass filter to restore it to a smooth sinusoidal high-voltage AC, reducing harmonics and ensuring the pure sinusoidal excitation required by DBD.

[0057] Control and signal modules: These include feedback and protection modules, heat dissipation and power management modules, and output interface modules. These modules are responsible for monitoring system status, ensuring stable and safe system operation, and managing power supply heat dissipation. Optionally, the control and signal modules can adjust the duty cycle and frequency in real time via SPWM (sinusoidal pulse width modulation) to achieve continuous adjustment of the output voltage amplitude and frequency (target 5–7kHz, 8–12kV peak).

[0058] in:

[0059] The feedback and protection module can collect discharge voltage, current and temperature in real time. When overvoltage, overcurrent or abnormal temperature rise occurs, it will immediately shut down or limit the inverter drive signal to achieve hardware-level fast protection.

[0060] The heat dissipation and power management module provides forced air cooling or liquid cooling for the rectifier bridge, inverter MOSFET / IGBT, control board, etc., and centrally manages the auxiliary power supply to ensure long-term stable operation of the system;

[0061] The output interface module can use a high-voltage shielded connector to safely feed the LC-filtered high-voltage sinusoidal signal into the DBD reactor, while simultaneously sending the reactor's monitoring signal back to the control / protection circuit without loss, thus completing electrical isolation and signal conditioning.

[0062] Discharge Module: The DBD reactor is the core component of the system, used to generate plasma and promote chemical reactions. The filtered high-voltage sinusoidal discharge is connected to the high-voltage end of the fluidized bed DBD reactor, and the external electrode is grounded (GND). A dielectric barrier discharge is formed inside the reactor, generating uniform plasma. The reactor simultaneously transmits the peak voltage / current and temperature signals of the discharge back to the feedback and protection module.

[0063] In one optional implementation, the diode of the rectifier module is selected as a fast recovery diode, the rated current is determined by equation (1), the reverse voltage is determined by equation (2), and the capacitance C of the above-mentioned voltage regulator capacitor is determined by equation (3).

[0064] I avg ≥1.5×I in (1)

[0065] V RRM ≥2×V ACpeak (2)

[0066]

[0067] Among them, I avg I is the rated current of the bridge rectifier diode. in For the input current, V ACpeak For the peak input AC voltage, I load Δt is the load current, Δt is the charging / discharging time, and ΔV is the ripple voltage.

[0068] In the sinusoidal pulse width modulation (SPWM) algorithm, the modulation ratio M is determined by equation (4), and the fundamental frequency f out It is determined by equation (5).

[0069]

[0070] Where V control V is the modulation amplitude value. triangular f is the carrier amplitude. SW Where is the switching frequency, and N is the carrier ratio.

[0071] Further optionally, in some embodiments, the effect of the electrohydrodynamics on the catalyst powder is mainly determined by the influence of the electric field distribution, dielectric force, particle polarization, and gas drag. The dielectric force is determined by equation (6), the particle polarization response time is determined by equation (7), and the gas drag on the particles is determined by equation (8).

[0072]

[0073] F D =3πμd p u g (8)

[0074] in Let d be the electric field gradient. p Where σ is the catalyst particle size, σ is the particle conductivity, and ε is the particle size. r ε0 represents the relative permittivity of the catalyst particles, and ε0 represents the vacuum permittivity.

[0075] The final fluidization criterion is that the combined force required for particle fluidization exceeds the sum of gravity and van der Waals forces (determined by equation (9)). During the formation of fluidization, dielectrophoresis force dominates the fluidization process, gas drag assists, and the combined force is sufficient to overcome particle gravity and van der Waals forces to achieve fluidization.

[0076] F DEP +F D ≥F g +F vdW (9)

[0077] Where F g For particle gravity, which is affected by particle density and particle size, F vdW For Van der Waals.

[0078] Through the coordinated operation of these modules, the entire system converts mains power into AC power suitable for the DBD reactor, and optimizes plasma generation and catalyst fluidization process by precisely controlling voltage and frequency, thereby improving the efficiency of ammonia synthesis.

[0079] Based on the above system, this application also provides a method for achieving catalyst fluidization.

[0080] Figure 5 This is a schematic flowchart illustrating a method for achieving catalyst fluidization, provided as an embodiment of this application. Figure 5 As shown, this method is applied to a fluidized bed dielectric barrier discharge system as described in the foregoing embodiments; the method specifically includes:

[0081] 501. Introduce the reaction gas into the reaction chamber containing the catalyst particles;

[0082] 502. Apply working voltage to the inner and outer electrodes through the power supply system to generate a non-uniform electric field using the mutually adapted curved surface structure, thereby applying dielectric force to the catalyst particles and fluidizing them; and adjust the voltage amplitude or frequency of the working voltage through the control unit to change the magnitude of the dielectric force, thereby matching the fluidization state of the catalyst particles with the reactor load.

[0083] The relevant structures and operational steps involved in the above methods can be referred to Figure 1 , Figure 2 , Figure 3 The structural diagram and related method descriptions shown are not repeated here.

[0084] Figure 6 This is a flowchart illustrating another method for achieving catalyst fluidization provided in an embodiment of this application, which describes in more detail the method flow based on the aforementioned system. For example... Figure 6 As shown, the method in this embodiment specifically includes:

[0085] Step S1: Load catalyst particles into the reactor. A specific type and quantity of catalyst powder 3 is loaded into the bottom of the reaction chamber through the feed port at the top of the reactor (not shown in the figure). The loading amount is one type of reactor load.

[0086] Step S2: Introduce the reaction gas. Close the feed port and seal the reactor. Turn on the gas source and introduce the reaction gas (such as a nitrogen-hydrogen mixture) into the reaction chamber through the gas inlet (such as gas inlet 8 in Example 1, or porous gas distribution plate 8” in Example 3) at a set flow rate.

[0087] Step S3: Apply initial voltage and frequency. Start the power system 100 and set an initial operating voltage amplitude and frequency through the user interface of the central control unit 140. For example, set the voltage to 8 kV and the frequency to 6 kHz. The power system 100 then applies this voltage parameter to the electrodes of the reactor 200, generating initial dielectric force, causing the catalyst particles to begin exhibiting fluidization characteristics.

[0088] Step S4: Monitor the fluidization state. The movement of the catalyst particles can be observed directly with the naked eye or a high-speed camera through an observation window installed on the reactor; alternatively, the fluidization state can be indirectly determined by monitoring pressure fluctuations within the reaction chamber. An ideal fluidization state is characterized by uniform suspension and vigorous turbulence of the particles, but without a large number of particles being excessively thrown high enough to touch the top ceramic insulating plug 2.

[0089] Step S5: Adjust the voltage or frequency online to match the load. The fluidization state is assessed based on the monitoring results from Step S4. If insufficient catalyst fluidization is observed, with most particles still bubbling or slightly vibrating at the bottom, it indicates that the current dielectric force is insufficient to completely overcome gravity and interparticle forces. In this case, the operator can smoothly increase the working voltage amplitude (e.g., gradually increasing from 8 kV to 10 kV) or fine-tune the frequency online through the central control unit 140 to increase the dielectric force until the ideal fluidization state is observed. Conversely, if excessive fluidization is observed and particle movement is out of control, the voltage amplitude should be appropriately reduced or the frequency adjusted. This adjustment process aims to precisely match the magnitude of the dielectric force, determined by the electric field parameters, with the current reactor load (including but not limited to catalyst type, particle size, density, loading amount, and gas flow rate) to find the optimal reaction kinetics conditions. Preferably, the voltage amplitude is adjusted within the range of 8 kV to 12 kV, and the frequency is adjusted within the range of 5 kHz to 7 kHz.

[0090] Step S6: Start the temperature control device. After achieving a stable fluidization state, start the liquid constant temperature heating device 6 to adjust and maintain the temperature of the reaction chamber within the temperature range most favorable for the catalytic reaction, such as 200°C to 300°C.

[0091] Step S7: Continue the reaction and collect the products. The chemical reaction continues under stable fluidization, discharge, and temperature conditions. Product gases are continuously discharged from outlet 7 and processed by subsequent gas analysis and collection equipment.

[0092] The system and method provided in this embodiment can achieve active, precise and dynamic control of the catalyst fluidization state, thereby ensuring that the plasma catalytic reaction can be carried out under optimal conditions under different reactor loads and process requirements, so as to obtain higher reaction efficiency and yield.

[0093] In summary, the modular power system design in this embodiment provides dual protection for the stability and safety of the plasma ammonia synthesis process. The power system employs an input processing and rectification module, along with an inverter frequency modulation module, to convert mains power into AC power with precisely adjustable voltage and frequency, meeting the flexible voltage and frequency requirements of fluidized bed dielectric barrier discharge. Combined with a feedback protection module that monitors output parameters in real time and a dynamically controlled heat dissipation management system, it effectively avoids discharge instability caused by current fluctuations and abnormal temperatures. The reactor utilizes an optimized combination structure of a metal mesh external electrode and a quartz dielectric tube, which not only suppresses the risk of arc discharge through the dielectric barrier layer but also significantly improves the uniformity of the electric field distribution, providing an ideal reaction environment for fluidized bed dielectric barrier discharge.

[0094] This application's embodiments, by introducing a design concept combining electrohydraulic effects and fluidized bed technology, overcome the technical bottlenecks of limited contact area and uneven distribution caused by fixed catalyst stacking in traditional plasma catalysis systems. This invention, through precise control of the gas flow rate and the synergistic effect of plasma electrohydraulic effects, enables the catalyst powder to form a dynamically suspended fluidized state within the reaction chamber, increasing the effective contact area between the catalyst and plasma and significantly improving the synergistic efficiency of plasma and catalyst. The unique porous spherical structure design at the end of the metal internal electrode further optimizes gas diffusion uniformity, and combined with the uniform through-hole layout of the ceramic insulating plug, it ensures smooth gas flow while preventing catalyst powder escape. Furthermore, the introduction of a liquid constant-temperature heating device allows for precise control of the reaction temperature, avoiding the decrease in reaction efficiency caused by temperature gradients in traditional methods.

[0095] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0096] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A fluidized bed dielectric barrier discharge reactor, characterized in that, include: A medium-blocking tube that defines the reaction chamber; Catalyst particles disposed within the reaction chamber; An inner electrode and an outer electrode are respectively disposed inside and outside the dielectric barrier tube; and a gas inlet is used to introduce the reaction gas into the reaction chamber; in: The end of the inner electrode and the bottom of the dielectric barrier tube have mutually compatible curved surface structures. The mutually adapted curved structure is used to generate a non-uniform electric field in the bottom region of the reaction chamber when a working voltage is applied between the inner and outer electrodes. The non-uniform electric field generates a dielectric force on the catalyst particles placed therein, thereby driving the catalyst particles to form a fluidized state in the reaction chamber.

2. The fluidized bed dielectric barrier discharge reactor according to claim 1, characterized in that, The end of the inner electrode is a spherical structure, and the bottom of the dielectric barrier tube is a hemispherical structure adapted to the spherical structure.

3. The fluidized bed dielectric barrier discharge reactor according to claim 2, characterized in that, The inner electrode has a hollow structure, and its internal channel forms the gas inlet, which is used to introduce the reaction gas from the end of the spherical structure of the inner electrode into the reaction chamber.

4. The fluidized bed medium barrier discharge reactor according to claim 1, characterized in that, The fluidized bed dielectric barrier discharge reactor further includes: A ceramic insulating plug is disposed at the upper part of the reaction chamber; the ceramic insulating plug is used to fix the inner electrode and is provided with a through hole for the reaction product gas to pass through and to block the catalyst particles from escaping.

5. The fluidized bed medium barrier discharge reactor according to claim 1, characterized in that, The fluidized bed dielectric barrier discharge reactor further includes: A temperature control device installed outside the reactor is used to control the temperature of the reaction chamber within a preset reaction temperature range.

6. A fluidized bed dielectric barrier discharge system, characterized in that, Includes a fluidized bed medium barrier discharge reactor as described in any one of claims 1-5; and further includes a power supply system for supplying power to the reactor; The power supply system includes a frequency and voltage regulation module and a control unit; The control unit is used to adjust the output of the frequency and voltage modulation module to control the voltage amplitude and frequency of the working voltage applied to the inner and outer electrodes, thereby adjusting the magnitude of the dielectric force.

7. The fluidized bed dielectric barrier discharge system according to claim 6, characterized in that, The power supply system also includes: The input processing and rectification module is used to receive external AC input, perform filtering, rectification and preliminary voltage regulation, and input the obtained stable voltage to the frequency modulation and voltage regulation module; The feedback and protection module is used to monitor the output status in real time to ensure the stability and safety of the fluidized bed medium barrier discharge ammonia production system; The heat dissipation and power management module is used for heat dissipation and power management control to ensure the long-term stable operation of the equipment; The output interface module is used to connect to the reactor high-voltage terminal of the fluidized bed medium barrier discharge system to ensure safe discharge of the fluidized bed medium barrier discharge reactor.

8. The fluidized bed dielectric barrier discharge system according to claim 7, characterized in that, The input processing and rectification module includes a bridge rectifier diode; The bridge rectifier diodes are selected as fast recovery diodes, with a rated current of I... avg ≥1.5×I in The reverse voltage is determined by V. RRM ≥2×V ACpeak The decision was made that the voltage regulator capacitor would be supplied by... The decision, of which, I avg I is the rated current of the bridge rectifier diode. in For the input current, V ACpeak For the peak input AC voltage, I load Δt is the load current, Δt is the charging / discharging time, and ΔV is the ripple voltage.

9. The fluidized bed dielectric barrier discharge system according to claim 7, characterized in that, The frequency and voltage regulation module is specifically used to convert DC voltage into frequency-adjustable AC power, and in conjunction with an LC filter, further output a stable sinusoidal AC power to supply the fluidized bed medium barrier discharge reactor for discharge.

10. A method for achieving catalyst fluidization, characterized in that, The method is applied to a fluidized bed dielectric barrier discharge system as described in any one of claims 7-9; the method includes: The reaction gas is introduced into the reaction chamber containing catalyst particles; A working voltage is applied to the inner and outer electrodes via the power system to generate a non-uniform electric field using the mutually adapted curved surface structure, thereby applying dielectric force to the catalyst particles and fluidizing them; and The voltage amplitude or frequency of the operating voltage is adjusted by the control unit to change the magnitude of the dielectric force, thereby matching the fluidization state of the catalyst particles with the reactor load.

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