Surface dielectric barrier discharge plasma ammonia synthesis device
By using lead zirconate titanate dielectric plates and specific electrode structures in a dielectric barrier discharge system, partial discharge and efficient ammonia synthesis are achieved, solving the problems of high ammonia yield and high energy consumption, and realizing efficient and low-energy ammonia synthesis.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XI AN JIAOTONG UNIV
- Filing Date
- 2026-01-22
- Publication Date
- 2026-06-02
AI Technical Summary
In existing dielectric barrier discharge systems, ammonia production is low and energy consumption is high, which is limited by the fact that the discharge zone fills the entire air gap, leading to the decomposition of ammonia products, and the insufficient surface charge of the dielectric material.
Lead zirconate titanate is used as the surface dielectric material. High concentrations of ammonia are generated through partial discharge and rapidly diffused into the non-discharge region, increasing the surface charge and promoting the ammonia synthesis reaction. A combination structure of lead zirconate titanate dielectric plate, metal sheet electrode and hexagonal mesh stainless steel electrode is used in conjunction with an alternating power supply to carry out the plasma reaction of nitrogen and hydrogen.
It significantly improves ammonia synthesis efficiency and energy efficiency, with lower energy consumption than the traditional HB process. The device is compatible with renewable energy sources, has a large gas processing volume, a simple structure that is easy to expand, an ammonia yield of up to 539 μmol/h, and an energy efficiency of 1.53 g/kWh.
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Figure CN122124726A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of ammonia synthesis by atmospheric pressure plasma technology, and particularly relates to a surface dielectric barrier discharge plasma ammonia synthesis device. BACKGROUND
[0002] As one of the most important basic chemical products in the world, ammonia is widely used in the fields of chemical fertilizers and fine chemicals. In addition, ammonia is easy to liquefy, has high energy density and low storage and transportation cost, and is a promising carbon-free fuel and hydrogen energy carrier. At present, the industrial synthesis of ammonia mainly relies on the Haber-Bosch (H-B) process, which uses high temperature and high pressure to drive the nitrogen-hydrogen reaction balance, consumes 1-2% of the global energy and emits more than 300 million tons of carbon dioxide per year. Therefore, developing ammonia synthesis technology under normal temperature and pressure conditions suitable for distributed and renewable energy-driven ammonia synthesis is of great significance for realizing the sustainable production of ammonia.
[0003] In recent years, various alternative synthesis paths such as electrochemistry, biochemistry and plasma have attracted widespread attention. Among them, non-thermal plasma can effectively activate nitrogen molecules under mild conditions due to its high-energy electrons and active species, realizing green synthesis of ammonia. However, in a typical dielectric barrier discharge system, the ammonia yield needs to be improved, which is limited by two reasons: (i) the discharge zone fills the entire gas gap, which leads to the easy decomposition of ammonia products by high-energy electrons; (ii) the dielectric material is usually quartz or ceramic, and the surface charge during the discharge process is low, which is not conducive to the occurrence of the forward reaction of ammonia production.
[0004] The information disclosed in the background section merely serves to enhance the understanding of the background of the present application, and therefore can contain information that does not constitute prior art that is already known to those of ordinary skill in the art. SUMMARY
[0005] In view of the deficiencies or shortcomings of the prior art, a surface dielectric barrier discharge plasma ammonia synthesis device is provided. The use of lead zirconate titanate as a surface dielectric barrier discharge can achieve local discharge on the surface of an insulating material. The high concentration of ammonia produced in the plasma region can rapidly diffuse to the non-discharge zone, reducing the occurrence of ammonia decomposition, providing a new path for the energy efficiency improvement of ammonia synthesis. The use of lead zirconate titanate as a dielectric material can increase the surface charge during the discharge process, promote the forward progress of the ammonia synthesis reaction, and produce a higher concentration of ammonia at a certain power, so that the plasma ammonia synthesis process achieves high efficiency and low energy consumption.
[0006] The purpose of the present application is achieved by the following technical solutions.
[0007] A surface dielectric barrier discharge plasma ammonia synthesis device comprises,
[0008] a reactor comprising,
[0009] The container has an opening, an inlet for introducing nitrogen and hydrogen, and an outlet for discharging ammonia.
[0010] A lead zirconate titanate dielectric plate is hermetically disposed at the opening to form a sealed space with the container.
[0011] A metal sheet electrode is disposed on the side of the lead zirconate titanate dielectric plate away from the container.
[0012] A hexagonal mesh stainless steel electrode is disposed on the side of the lead zirconate titanate dielectric plate near the container.
[0013] A stainless steel L-shaped metal rod, comprising a first section placed inside a container as a hexagonal mesh stainless steel electrode connector and a second section extending perpendicularly out of the container from the first section.
[0014] A discharge power supply is connected to a metal sheet electrode and a stainless steel L-shaped metal rod, which causes nitrogen and hydrogen in the container to undergo a plasma reaction to generate ammonia.
[0015] The surface dielectric barrier discharge plasma ammonia synthesis device also includes a connecting fastener, one side of which is fixed to the side of the container, and the other side is fixed to the second section.
[0016] In the aforementioned surface dielectric barrier discharge plasma ammonia synthesis device, the container is provided with a single-pass interface adapted to the diameter of the second section, the connecting fastener is made of insulating material, the interfaces on both sides of the connecting fastener are formed with threaded structures, and the other side is provided with a ferrule structure placed inside the nut and fitted outside the second section, and the second section is fixed by screwing in the nut.
[0017] In the aforementioned surface dielectric barrier discharge plasma ammonia synthesis device, the insulating material is polytetrafluoroethylene (PTFE).
[0018] In the aforementioned surface dielectric barrier discharge plasma ammonia synthesis device, the opening at the top of the container is square, and the side of the container has an inlet for introducing nitrogen and hydrogen and an outlet for discharging tail gas containing ammonia. The inlet is connected to the nitrogen and hydrogen gas source.
[0019] In the aforementioned surface dielectric barrier discharge plasma ammonia synthesis device, the lead zirconate titanate dielectric plate is square in shape and adapted to the size of the opening at the top of the container; the metal sheet electrode is placed on the upper center of the lead zirconate titanate dielectric plate and is attached to it; the hexagonal mesh stainless steel electrode is placed on the lower center of the lead zirconate titanate dielectric plate and is attached to it.
[0020] In the aforementioned surface dielectric barrier discharge plasma ammonia synthesis device, the lead zirconate titanate dielectric plate is a square flat sheet with a side length of 50cm and a thickness of 0.1cm.
[0021] In the aforementioned surface dielectric barrier discharge plasma ammonia synthesis device, the metal sheet electrode is a square copper foil with a side length smaller than that of the lead zirconate titanate dielectric plate. It is placed on the upper center of the lead zirconate titanate dielectric plate and tightly attached to it. It is connected to the positive terminal of the power supply through a wire. The hexagonal mesh stainless steel electrode has a side length equal to that of the metal sheet electrode. It is placed on the lower center of the lead zirconate titanate dielectric plate and tightly attached to it. It is connected to the negative terminal of the power supply through a stainless steel L-shaped metal rod.
[0022] In the aforementioned surface dielectric barrier discharge plasma ammonia synthesis device, a stainless steel L-shaped metal rod is connected to a hexagonal mesh stainless steel electrode by winding with wires.
[0023] In the aforementioned surface dielectric barrier discharge plasma ammonia synthesis device, the discharge power supply is an alternating power supply with a discharge voltage of at least 500V and a discharge frequency of at least 40kHz.
[0024] Compared with the prior art, the beneficial effects of this invention are as follows:
[0025] This invention exhibits high chemical reactivity. Under the same operating conditions, the lead zirconate titanate dielectric plate used in this invention can enrich electrons on its surface, thereby effectively improving the chemical reaction kinetics in the plasma ammonia synthesis process and significantly enhancing the ammonia synthesis efficiency. Energy consumption is low; the theoretical energy consumption of the plasma nitrogen fixation process is at least 2.5 times lower than that of the HB method. Compared with traditional industrial ammonia production methods, the ammonia produced by the device of this invention is generated solely through a discharge device, requiring no fossil fuels and eliminating greenhouse gas emissions. When the same gas flow rate is introduced, the power of the traditional dielectric barrier discharge device reaches 20-60W, resulting in very low energy efficiency. In contrast, the reactor in the device of this invention has a discharge power of 6W and produces a stable high concentration of ammonia. The entire device can be started and stopped at any time, is compatible with renewable resources such as solar and wind power, and is environmentally friendly. It can handle large volumes of gas. DBD ammonia production devices with similar structures to this invention, due to the plasma filling the discharge gap, handle smaller gas volumes, typically only a few milliliters. The device of this invention confines the plasma near the surface of the medium, and diffuses the product ammonia into the non-plasma region through diffusion circulation, reducing the decomposition of the product ammonia and increasing the processed gas volume to several liters. The device has a simple structure, is easy to expand, and can process several cubic meters of gas through array distribution.
[0026] The description provided is merely an overview of the technical solution of this invention. In order to make the technical means of this invention clearer and more understandable, so that those skilled in the art can implement it according to the contents of the specification, and to make the described and other objects, features and advantages of this invention more obvious and understandable, specific embodiments of this invention are described below. Attached Figure Description
[0027] Various other advantages and benefits of the present invention will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. Furthermore, the same reference numerals denote the same parts throughout the drawings.
[0028] In the attached diagram:
[0029] Figure 1 This is a schematic diagram of the overall structure of the present invention. Figure 1 In the image, the left side is a front view of the plasma reactor, and the right side is a bottom view of the plasma generator.
[0030] Figure 2 To compare the Lissajous figures of the device of the present invention and other dielectric materials as dielectric plates when using the device of the present invention as a dielectric plate with the same discharge power of 6W, the Lissajous figures of the device of the present invention and other dielectric materials as dielectric plates were compared. The device of the present invention reduces the discharge voltage and increases the surface charge. The increased high-energy electrons on the dielectric surface can enhance the reactivity of nitrogen and hydrogen.
[0031] Figure 3 This is a statistical diagram illustrating the variation of ammonia production rate with discharge power using the device of this invention, other dielectric materials as dielectric plates, and a conventional DBD device. With increasing power, the ammonia production rate of both the device of this invention and the conventional DBD device shows a slow upward trend. At a typical discharge power of 6W, the ammonia production rate of the device of this invention can reach 539 μmol / h, while that of the conventional DBD device is only 79 μmol / h. These test results are attached. Figure 1 The example of its specific implementation method is implemented in which the input gas is a mixture of nitrogen and hydrogen in a ratio of 1:2, and the gas flow rate is 120 ml / min;
[0032] Figure 4 The attached diagram illustrates the statistical variation of ammonia production energy efficiency with discharge power using the device of this invention and a conventional DBD device. Figure 2 Energy efficiency calculation;
[0033] Figure 5 This is a statistical diagram showing the change in ammonia production rate with discharge power after being combined with the MCM-41 catalyst in another example of the present invention. 100 mg of particulate catalyst MCM-41 with a particle size of 50 mesh (about 300 μm) is placed on the surface of the dielectric plate. The synergistic effect of the device and the catalyst described in the present invention can further enhance the ammonia production rate.
[0034] The present invention will be further explained below with reference to the accompanying drawings and embodiments. Detailed Implementation
[0035] Specific embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While specific embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.
[0036] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions are preferred embodiments for carrying out the invention; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of the invention. The scope of protection of this invention is determined by the appended claims.
[0037] To facilitate understanding of the embodiments of the present invention, the following will provide further explanation and description with reference to the accompanying drawings and several specific embodiments, and the accompanying drawings do not constitute a limitation on the embodiments of the present invention.
[0038] To better understand, such as Figures 1 to 5 As shown, a surface dielectric barrier discharge plasma ammonia synthesis device includes,
[0039] Reactor 1, which includes,
[0040] Container 3 has an opening, an inlet for introducing nitrogen and hydrogen, and an outlet for discharging ammonia.
[0041] A lead zirconate titanate dielectric plate 1001 is sealed at the opening to form a closed space with the container 3.
[0042] A metal sheet electrode 1002 is disposed on the side of the lead zirconate titanate dielectric plate 1001 away from the container 3.
[0043] A hexagonal mesh stainless steel electrode 1003 is disposed on the side of the lead zirconate titanate dielectric plate 1001 near the container 3.
[0044] Stainless steel L-shaped metal rod 2001, which includes a first section placed inside the container 3 as a connector for a hexagonal mesh stainless steel electrode 1003 and a second section extending perpendicularly out of the container 3 from the first section.
[0045] A discharge power supply is connected to a metal sheet electrode 1002 and a stainless steel L-shaped metal rod 2001, respectively, so that nitrogen and hydrogen in the container 3 undergo a plasma reaction to generate ammonia.
[0046] In a preferred embodiment of the surface dielectric barrier discharge plasma ammonia synthesis device, a connecting fastener 2002 is further included, one side of which is fixed to the side of the container 3, and the other side is fixed to the second segment.
[0047] In a preferred embodiment of the surface dielectric barrier discharge plasma ammonia synthesis device, the container 3 is provided with a single-through interface adapted to the diameter of the second section, the connecting fastener 2002 is made of insulating material, the two sides of the connecting fastener 2002 have threaded structures, and the other side is provided with a ferrule structure placed inside the nut and fitted outside the second section, and the second section is fixed by screwing in the nut.
[0048] In a preferred embodiment of the surface dielectric barrier discharge plasma ammonia synthesis device, the insulating material is polytetrafluoroethylene (PTFE).
[0049] In a preferred embodiment of the surface dielectric barrier discharge plasma ammonia synthesis device, the opening at the top of the container 3 is square, and the side of the container 3 has an inlet for introducing nitrogen and hydrogen and an outlet for discharging tail gas containing ammonia. The inlet is connected to the nitrogen and hydrogen gas source.
[0050] In a preferred embodiment of the surface dielectric barrier discharge plasma ammonia synthesis device, the lead zirconate titanate dielectric plate 1001 is square in shape and adapted to the size of the top opening of the container 3; the metal sheet electrode 1002 is placed on the upper center of the lead zirconate titanate dielectric plate 1001 and attached to it; the hexagonal mesh stainless steel electrode 1003 is placed on the lower center of the lead zirconate titanate dielectric plate 1001 and attached to it.
[0051] In a preferred embodiment of the surface dielectric barrier discharge plasma ammonia synthesis device, the lead zirconate titanate dielectric plate 1001 is a square flat sheet with a side length of 50cm and a thickness of 0.1cm.
[0052] In a preferred embodiment of the surface dielectric barrier discharge plasma ammonia synthesis device, the metal sheet electrode 1002 is a square copper foil with a side length smaller than that of the lead zirconate titanate dielectric plate 1001, placed at the center of the upper side of the lead zirconate titanate dielectric plate 1001 and tightly attached, and connected to the positive terminal of the power supply through a wire. The hexagonal mesh stainless steel electrode 1003 has a side length equal to that of the metal sheet electrode 1002, placed at the center of the lower side of the lead zirconate titanate dielectric plate 1001 and tightly attached, and connected to the negative terminal of the power supply through a stainless steel L-shaped metal rod 2001.
[0053] In a preferred embodiment of the surface dielectric barrier discharge plasma ammonia synthesis device, a stainless steel L-shaped metal rod 2001 is connected to a hexagonal mesh stainless steel electrode 1003 by winding with wires.
[0054] In a preferred embodiment of the surface dielectric barrier discharge plasma ammonia synthesis device, the discharge power supply is an alternating power supply with a discharge voltage of at least 500V and a discharge frequency of at least 40kHz.
[0055] In one embodiment, the surface dielectric barrier discharge plasma ammonia synthesis apparatus includes a lead zirconate titanate dielectric plate 1001, a stainless steel sheet electrode, a hexagonal mesh stainless steel electrode 1003, a stainless steel connector, a container 3 with an outlet and an inlet, and a connecting fastener 2002. Dielectric barrier discharge occurs in the hexagonal air gap between the lead zirconate titanate dielectric plate 1001 and the mesh electrode, directly acting on the nitrogen and hydrogen gases in the container 3. The produced ammonia diffuses into the chamber and is discharged to the outside through the outlet, thus realizing ammonia production. The connecting fastener 2002 and the stainless steel L-shaped metal rod 2001 constitute the connecting part 2.
[0056] In one embodiment, the surface dielectric barrier discharge plasma ammonia synthesis apparatus includes...
[0057] The reactor includes:
[0058] Lead zirconate titanate dielectric plate 1001 is square in shape and is adapted to the top dimensions of container 3;
[0059] A metal sheet electrode 1002 is placed and attached to the upper center of the lead zirconate titanate dielectric plate 1001;
[0060] A hexagonal mesh stainless steel electrode 1003, serving as a low-voltage electrode, is placed and attached to the lower center of the lead zirconate titanate dielectric plate 1001.
[0061] Stainless steel L-shaped metal rod 2001 is placed inside the device as a connector for hexagonal mesh stainless steel electrode 1003 and is fixed by connecting fastener 2002.
[0062] Container 3 is used to fill gas and fit tightly with lead zirconate titanate dielectric plate 1001;
[0063] The connecting fastener 2002 is fixed to the right side of container 3, and the stainless steel L-shaped metal rod 2001 is fixed to the left side.
[0064] Discharge power supply, connected to stainless steel sheet electrode and stainless steel L-shaped metal rod 2001.
[0065] In one embodiment, a metal sheet electrode connected to a wire is attached to the upper side of the lead zirconate titanate dielectric plate 1001 as a high-voltage electrode, and a hexagonal mesh stainless steel electrode 1003 connected to a stainless steel L-shaped metal rod 2001 is attached to the lower side of the lead zirconate titanate dielectric plate 1001 as a low-voltage electrode. The surface dielectric barrier discharge plasma reactor is fixed to the top of the container 3 and fits tightly with the container 3.
[0066] In one embodiment, the interfaces on both sides of the connecting fastener 2002 are threaded. A retainer structure is required on the left side, placed inside a nut and fitted over the stainless steel L-shaped metal rod 2001. The nut is screwed in to secure the stainless steel L-shaped metal rod 2001 and ensure airtightness. The sheet metal electrode 1002 is a square copper foil with a side length smaller than that of the lead zirconate titanate dielectric plate 1001. It is placed at the upper center of the lead zirconate titanate dielectric plate 1001 and tightly fitted, connected to the positive terminal of the power supply via a wire. The hexagonal mesh stainless steel electrode 1003 has a side length equal to that of the sheet metal electrode 1002. It is placed at the lower center of the lead zirconate titanate dielectric plate 1001 and tightly fitted, connected to the negative terminal of the power supply via the stainless steel L-shaped metal rod 2001. Specifically, the hexagonal mesh stainless steel electrode 1003 needs to be polished smooth to ensure stable plasma generation. The stainless steel L-shaped metal rod 2001 is connected to the hexagonal mesh stainless steel electrode 1003, ensuring good contact through wire winding or other methods.
[0067] In one embodiment, the metal sheet electrode 1002 is placed on the upper side of the lead zirconate titanate dielectric plate 1001 and is tightly attached; the hexagonal stainless steel mesh electrode 1003 is placed on the lower side of the lead zirconate titanate dielectric plate 1001 and is tightly attached.
[0068] In one embodiment, the metal sheet electrode 1002 and the hexagonal stainless steel mesh electrode 1003 have the same side length and are positioned at the center of both sides of the lead zirconate titanate dielectric plate 1001. Fixing methods can include adhesive bonding, external support, etc. The left side of the connecting fastener 2002 is connected to the stainless steel L-shaped metal rod 2001, and the right side is connected to the container sidewall. The left interface is a bolt and threaded structure, and the right interface is a threaded interface. The connecting fastener should be made of insulating material; in a preferred embodiment of the invention, the connecting fastener is made of polytetrafluoroethylene (PTFE). Good airtightness of the connecting fastener is achieved through the fit of the ferrule and bolt structure and the tight fit of the threads. The gas introduced through the gas pipeline can be a gas cylinder or a hydrogen generator, and the flow rate needs to be controlled and stabilized using a gas mass flow meter. In a preferred embodiment of the invention, the ratio of nitrogen to hydrogen is 1:2, and the gas flow rate is controlled at 120 mL / min. The top of the container is fixed by adhesive bonding to ensure at least the chamber is airtight.
[0069] The metal sheet electrode 1002 and the stainless steel L-shaped metal rod 2001 in this device can be made of common metals, including but not limited to 304 stainless steel, tungsten steel, copper, etc. It is important to note that the metal sheet electrode should have a smooth and flat surface to ensure uniform and stable surface dielectric barrier discharge and extend its service life.
[0070] In this device, the stainless steel L-shaped metal rod 2001 is reliably connected to the hexagonal mesh electrode 1003. Connection methods can include wire wrapping, metal clips, etc., to ensure good contact between the two.
[0071] In this device, the metal sheet electrode 1002 and the stainless steel L-shaped metal rod 2001 are connected. The power supply providing voltage for discharge is not limited to a fixed type. In a preferred embodiment of the invention, a high-frequency AC power supply is used, with a voltage of 500V or higher and a frequency of 40kHz or higher.
[0072] Furthermore, the container here includes any form of barrel, bottle, box, can, bucket, tube, cup, and other fixed-shape container that can hold liquids. Preferably, the container may be made of a material with good light transmittance to facilitate observation of surface dielectric barrier discharge.
[0073] The following describes the practical effects of a specific embodiment of the present invention:
[0074] In the above specific implementation method, the input gas is a mixture of nitrogen and hydrogen in a ratio of 1:2, and the gas flow rate is 120 ml / min. Figure 2 The Lissajous waveforms of the device of the present invention were compared with those of different dielectric materials used as dielectric plates. Figure 3 The ammonia production rates of the device of the present invention, with different media materials as media plates, and a conventional DBD device were compared at a series of power levels. Figure 4The energy efficiency of the device of this invention was compared with that of conventional DBD at various power levels. At a typical discharge power of 6W, the maximum surface charge of the lead zirconate titanate dielectric plate in the device of this invention is 2-3 times that of dielectric plates made of other materials, exhibiting extremely high reactivity. The ammonia production rate of the device of this invention can reach 539 μmol / h, far exceeding the ammonia production rate of other dielectric materials used as dielectric plates, while that of conventional DBD devices is only 79 μmol / h. Under these operating conditions, the ammonia synthesis energy efficiency of the device of this invention is as high as 1.53 g / kWh, which is 6.8 times that of conventional DBD.
[0075] This invention employs square-shaped lead zirconate titanate as the dielectric layer. It provides a high dielectric constant and good polarization characteristics, enhancing the uniformity of the electric field distribution; it improves the charge accumulation capacity of the dielectric surface, thereby increasing plasma reactivity; and when used with metal electrodes, it achieves stable dielectric barrier discharge (DBD) to prevent breakdown. Compared to traditional glass or quartz dielectrics, it has a higher surface charge density, significantly improving ammonia synthesis efficiency.
[0076] Stainless steel is processed into a hexagonal mesh structure and attached to the underside of the lead zirconate titanate dielectric plate. The mesh structure reduces local electric field concentration, achieving more uniform discharge; increases the contact area between the gas and the electrode, promoting the excitation and reaction of nitrogen and hydrogen; reduces electrode shielding effects, resulting in a wider plasma region and higher reaction efficiency; the hexagonal design optimizes space utilization, facilitating multi-module integration and expansion. Small square electrodes made of copper foil are attached to the center of the upper side of the lead zirconate titanate dielectric plate. Copper's excellent conductivity ensures stable high-voltage transmission; its size is slightly smaller than the dielectric plate, avoiding edge discharge and energy loss; its central arrangement helps form a symmetrical discharge region, improving discharge stability; and it forms an effective discharge gas gap with the mesh electrode below, generating highly active plasma. L-shaped stainless steel rods are used as connectors and fixed to the container wall using PTFE-insulated fasteners. This system achieves reliable connection between the low-voltage electrode and the external power supply; the L-shaped structure facilitates internal electrode wiring and external power connection; PTFE material provides excellent insulation and airtightness; the ferrule + threaded structure ensures a secure connection and prevents gas leakage; the overall structure enhances the safety and stability of the device. It uses an alternating power supply with a voltage ≥500V and a frequency ≥40kHz. The high-frequency power supply reduces the plasma discharge pulse interval, improving reaction continuity; high voltage starts and maintains a stable dielectric barrier discharge process; it prevents arc discharge, ensuring safe operation; it improves electron energy distribution, increasing reaction rate and energy utilization efficiency. A sealed space maintains the required gas atmosphere for the reaction; gas path control precisely adjusts the nitrogen-hydrogen ratio (e.g., 1:2) and flow rate (e.g., 120mL / min); the open structure facilitates disassembly, maintenance, and replacement of electrodes / dielectric plates; and transparent materials can be selected for easy observation of the discharge state and reaction process. The integrated design of the lead zirconate titanate dielectric plate, upper and lower electrodes, connection structure, power supply, and container forms a highly efficient surface dielectric barrier discharge structure that directly acts on the reactant gas. This significantly increases the generation of free radicals, atomic nitrogen, and hydrogen in the plasma, substantially improving the ammonia synthesis rate (up to 539 μmol / h) and energy efficiency (up to 1.53 g / kWh). Its compact structure and easy modular expansion make it suitable for industrial-grade ammonia synthesis applications. Lissajous waveform comparisons show that this device has strong charge accumulation capabilities and more stable discharge; ammonia production rate comparison: this device is more than 6 times higher than ordinary DBD devices; energy efficiency comparison: this device is 6.8 times that of ordinary DBD devices.
[0077] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.
Claims
1. A surface dielectric barrier discharge plasma ammonia synthesis device, characterized in that, It includes, The reactor includes, The container has an opening, an inlet for introducing nitrogen and hydrogen, and an outlet for discharging ammonia. A lead zirconate titanate dielectric plate is hermetically disposed at the opening to form a sealed space with the container. A metal sheet electrode is disposed on the side of the lead zirconate titanate dielectric plate away from the container. A hexagonal mesh stainless steel electrode is disposed on the side of the lead zirconate titanate dielectric plate near the container. A stainless steel L-shaped metal rod, comprising a first section placed inside a container as a hexagonal mesh stainless steel electrode connector and a second section extending perpendicularly out of the container from the first section. A discharge power supply is connected to a metal sheet electrode and a stainless steel L-shaped metal rod, which causes nitrogen and hydrogen in the container to undergo a plasma reaction to generate ammonia.
2. The surface dielectric barrier discharge plasma ammonia synthesis apparatus as described in claim 1, characterized in that, Preferably, it also includes a connecting fastener, one side of which is fixed to the side of the container and the other side of which is fixed to the second segment.
3. The surface dielectric barrier discharge plasma ammonia synthesis apparatus as described in claim 2, characterized in that, The container is provided with a single-through interface that adapts to the diameter of the second section. The connecting fastener is made of insulating material. The interfaces on both sides of the connecting fastener have a threaded structure, and the other side has a ferrule structure placed inside the nut and fitted outside the second section. The second section is fixed by screwing in the nut.
4. The surface dielectric barrier discharge plasma ammonia synthesis apparatus as described in claim 3, characterized in that, The insulation material is polytetrafluoroethylene.
5. The surface dielectric barrier discharge plasma ammonia synthesis apparatus as described in claim 1, characterized in that, The container has a square opening at the top and an inlet on the side for introducing nitrogen and hydrogen gas and an outlet for discharging tail gas containing ammonia. The inlet is connected to a nitrogen and hydrogen gas source.
6. The surface dielectric barrier discharge plasma ammonia synthesis apparatus as described in claim 5, characterized in that, The lead zirconate titanate dielectric plate is square in shape and fits the opening size at the top of the container; the metal sheet electrode is placed on the upper center of the lead zirconate titanate dielectric plate and is attached; the hexagonal mesh stainless steel electrode is placed on the lower center of the lead zirconate titanate dielectric plate and is attached.
7. The surface dielectric barrier discharge plasma ammonia synthesis apparatus as described in claim 6, characterized in that, The lead zirconate titanate dielectric substrate is a square flat sheet with a side length of 50cm and a thickness of 0.1cm.
8. The surface dielectric barrier discharge plasma ammonia synthesis apparatus as described in claim 1, characterized in that, The metal sheet electrode is a square copper foil with a side length smaller than that of the lead zirconate titanate dielectric substrate. It is placed on the upper center of the lead zirconate titanate dielectric substrate and is tightly attached to it. It is connected to the positive terminal of the power supply through a wire. The hexagonal mesh stainless steel electrode has a side length equal to that of the metal sheet electrode. It is placed on the lower center of the lead zirconate titanate dielectric substrate and is tightly attached to it. It is connected to the negative terminal of the power supply through a stainless steel L-shaped metal rod.
9. The surface dielectric barrier discharge plasma ammonia synthesis apparatus as described in claim 1, characterized in that, The stainless steel L-shaped metal rod is connected to the hexagonal mesh stainless steel electrode by winding with wire.
10. The surface dielectric barrier discharge plasma ammonia synthesis apparatus as described in claim 1, characterized in that, The discharge power supply is an alternating power supply, with a discharge voltage of at least 500V and a discharge frequency of at least 40kHz.