A suspended electrode gas-liquid mixed-phase discharge plasma generating device

Abstract

The utility model provides a kind of suspension electrode gas-liquid mixed phase discharge plasma generation device, including reactor body, the inside of the reactor body is closed cavity, the middle part of the closed cavity is provided with insulating plate, the closed cavity is divided into upper reaction chamber and lower reaction chamber by insulating plate;Ground electrode plate is provided in the upper reaction chamber, the ground electrode plate is connected ground wire, the upper reaction chamber is connected with the upper reaction chamber liquid circulation part being arranged outside the reactor body, the upper reaction chamber is connected with the separation device being arranged outside the reactor body;High-voltage electrode plate is provided in the lower reaction chamber, and the high-voltage electrode plate is connected with pulse power supply and gas storage device being arranged outside the reactor body respectively through air inlet.The plasma of the device can be generated in gas-liquid interface and bubble simultaneously, which improves nitrogen fixation efficiency and hydrogen production efficiency, improves product concentration and reduces energy consumption.

Description

Technical Field

[0001] This utility model relates to the field of low-temperature plasma technology, and more specifically, to a suspended electrode gas-liquid mixed-phase discharge plasma generator. Background Technology

[0002] Nitrogen fixation technology is a crucial process in agriculture and chemical industries, involving the conversion of atmospheric nitrogen into usable nitrogen compounds. Nitrogen is a key element for plant growth; however, due to the relative inertness of atmospheric nitrogen, it requires special treatment to make it easily absorbed by plants. Plasma nitrogen fixation technology has attracted attention. Commonly used plasma nitrogen fixation discharge methods include dielectric barrier discharge (DBD), sliding arc discharge, microwave discharge, and pulsed corona discharge. Among these, pulsed discharge nitrogen fixation technology has advantages such as high efficiency, high selectivity, energy saving and environmental protection, operational flexibility, and wide applicability, thus showing broad application prospects in the field of nitrogen fixation.

[0003] Currently available plasma nitrogen fixation devices can be divided into two types based on the discharge raw materials: gas-phase discharge and gas-liquid discharge. Gas-phase discharge plasma nitrogen fixation uses N2 / H2 mixtures or air as the raw material. Due to the gaseous nature of the raw material, these devices produce low plasma density, resulting in less than ideal nitrogen fixation and significant electrode wear. Especially when the reaction involves mixing hydrogen with other gases, besides the high cost of the gases, it is easy to enter the hydrogen explosion limit zone, leading to poor safety. Gas-liquid two-phase discharge nitrogen fixation uses water and nitrogen / air as the raw materials. These devices typically come in two forms: gas-liquid two-phase discharge above the liquid surface and bubble discharge within the liquid. Gas-liquid two-phase discharge devices above the liquid surface are simpler, but in most devices, the plasma does not have sufficient contact with the liquid surface, with only some active particles entering the solution, resulting in slightly lower nitrogen fixation efficiency. Bubble discharge within the liquid allows for sufficient contact with the liquid, but it results in less ionization of the gas, and the nitrogen fixation and ammonia production effect is also not ideal.

[0004] Arc discharge plasma nitrogen fixation is considered one of the large-scale nitrogen fixation methods. The multi-channel sliding arc nitrogen fixation device described in patent CN115999484A proposes a method of connecting multiple sliding arc devices in series to increase yield, but this method increases cost accordingly, without significantly improving yield and energy consumption. Furthermore, safety hazards exist when processing large quantities of compressed gas. The lack of a circulation device also affects the processing effect, and since the nitrogen fixation products are all gaseous, they are not convenient for direct use and need to be dissolved in water to generate nitrogen-fixing compounds such as nitrates before application.

[0005] Gas-liquid two-phase discharge plasma nitrogen fixation typically uses water and nitrogen or air as raw materials, offering low cost and high safety. Patent CN115554952A proposes using nanosecond pulsed spark discharge jet plasma for nitrogen fixation. This method generates plasma only in the gas phase, limiting plasma-water contact. Achieving efficient nitrogen-water conversion is challenging. Maintaining high NOx concentrations and low energy consumption under high flow conditions is also difficult. Patent CN115594257A proposes a bubble discharge nitrogen fixation device and method, generating plasma through air discharge and then dissolving the product in water using a bubble diffuser. However, this device has some drawbacks, such as the gaseous nitrogen fixation product not reacting directly with water, a lack of a circulation module limiting water treatment capacity, and low nitrogen fixation efficiency.

[0006] Patent CN117085615A proposes an apparatus and method for underwater bubble plasma nitrogen fixation, which generates discharge when flowing bubbles in water pass through an insulating perforated plate. The core discharge region of this device is within the flowing gas, which presents problems such as the gas flow rate affecting the discharge, and even preventing discharge when the flow rate increases significantly. Furthermore, the concentration of plasma products is limited by the volume of the plasma. Utility Model Content

[0007] To address the technical problem of low nitrogen fixation efficiency caused by the inability of existing gas-liquid two-phase discharge plasma nitrogen fixation technology to dissolve nitrogen fixation products in water, this invention provides a suspended electrode gas-liquid mixed-phase discharge plasma generator. The plasma of this invention can be generated simultaneously at the gas-liquid interface and in the bubbles, which improves nitrogen fixation efficiency, increases product concentration, and reduces energy consumption.

[0008] The technical means adopted in this utility model are as follows:

[0009] A suspended electrode gas-liquid mixed-phase discharge plasma generator includes a reactor body. The interior of the reactor body is a closed cavity. An insulating plate is disposed in the middle of the closed cavity, and the closed cavity is divided by the insulating plate into an upper reaction chamber and a lower reaction chamber. A grounding electrode plate is disposed in the upper reaction chamber and connected to a ground wire. The upper reaction chamber is connected to an upper reaction chamber liquid circulation section disposed outside the reactor body and is also connected to a separation device disposed outside the reactor body. A high-voltage electrode plate is disposed in the lower reaction chamber and is connected to a pulse power supply and a gas storage device disposed outside the reactor body through an air inlet. The lower reaction chamber is also connected to the lower reaction chamber liquid circulation section disposed outside the reactor body.

[0010] The upper surface of the middle part of the insulating plate is recessed downward to form a groove. A perforated metal plate is fixed at the upper part of the groove. The upper surface of the perforated metal plate is flush with the upper surface of the insulating plate. A floating electrode is disposed through the center of the perforated metal plate. A central hole is opened on the insulating plate at the lower part of the groove.

[0011] Furthermore, the liquid circulation section of the upper reaction chamber includes an upper reaction chamber end outlet and an upper reaction chamber end inlet connected to the upper reaction chamber at one end. The upper reaction chamber end outlet is higher than the upper reaction chamber end inlet. The other end of the upper reaction chamber end outlet is sequentially connected to an upper reaction chamber end circulation pump and an upper reaction chamber end liquid storage tank. The other end of the upper reaction chamber end inlet is sequentially connected to an upper reaction chamber end flow meter, an upper reaction chamber end valve, an upper reaction chamber end circulation pump, and an upper reaction chamber end liquid storage tank.

[0012] The lower reaction chamber liquid circulation section includes a lower reaction chamber end outlet and a lower reaction chamber end inlet connected to the lower reaction chamber at one end. The lower reaction chamber end outlet is higher than the lower reaction chamber end inlet. The other end of the lower reaction chamber end outlet is sequentially connected to the lower reaction chamber end circulation pump and the lower reaction chamber end liquid storage tank. The other end of the lower reaction chamber end inlet is sequentially connected to the lower reaction chamber end flow meter, the lower reaction chamber end valve, the lower reaction chamber end circulation pump, and the lower reaction chamber end liquid storage tank.

[0013] Furthermore, the separation device is connected to the upper reaction chamber via the gas outlet at the upper reaction chamber end, and a gas outlet flow meter is installed between the separation device and the gas outlet.

[0014] An inlet flow meter is installed between the gas storage device structure and the inlet.

[0015] Furthermore, the porous metal plate has vertical holes for placing the suspended electrode and several vent holes for gas circulation. The several vent holes are inclined from bottom to top towards the suspended electrode, and the angle between the several vent holes and the vertical line is in the range of 0-30°. The height of the gas buffer cavity between the lower surface of the porous metal plate and the insulating plate at the bottom of the groove is greater than 1mm.

[0016] Furthermore, the discharge forms of the pulse power supply include corona discharge, spark discharge, and arc discharge, and the pulse power supply can simultaneously realize gas-liquid mixed-phase interface discharge and liquid phase discharge.

[0017] Furthermore, the chamber material of the reactor is any one of quartz, glass, polytetrafluoroethylene, and ceramic.

[0018] Furthermore, the high-voltage electrode plate and the grounding electrode plate are plate electrodes, and the plate electrodes are provided with ventilation holes; the suspended electrode is a needle or rod electrode with both ends sharpened.

[0019] Furthermore, the diameter of the central hole is larger than the diameter of the suspended electrode, and the suspended electrode does not contact the insulating plate; the height of the lower part of the suspended electrode is equal to or lower than the height of the insulating plate.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. The apparatus for nitrogen fixation and ammonia synthesis provided by this utility model, by adjusting and limiting parameters such as voltage, frequency, gas flow rate, and electrode gap of the pulse power supply, changes the discharge form, such as corona discharge, streamer discharge, and spark discharge, releasing a large number of high-energy electrons in a short time, achieving electron avalanche and greatly improving Faraday efficiency. The needle and plate electrodes are respectively in two phases, which can improve nitrogen utilization. Adjusting the distance between the needle and plate electrode device and the liquid surface will change the discharge form. The large activation volume of the streamer and spark discharge plasma is beneficial to enhancing nitrogen dissociation, thereby improving the yield and energy efficiency of nitrogen fixation products.

[0022] 2. This utility model creatively proposes to use pulse power supply for discharge. The device is simple, occupies a small area, has low cost, is easy to operate, and has a short reaction time. It can achieve the effect of turning on and off immediately, and is green and environmentally friendly.

[0023] 3. This device fixes nitrogen using air, pure nitrogen, or a mixture of nitrogen and oxygen as raw materials, resulting in low pollution, no greenhouse gas emissions, and low energy consumption.

[0024] 4. The reaction chamber is divided into upper and lower sections. The liquid level in the lower section covers the bottom high-voltage electrode plate, while the liquid level in the upper section covers the suspended needle electrode. Small bubbles are generated at the bottom electrode plate, while gas enters the upper chamber through the holes in the porous metal plate connected to the suspended electrode. First, a gas-liquid surface discharge occurs in the lower chamber, with plasma ignited from the needle tip and exploding at the liquid surface. High-energy metastable particles are generated at the gas phase and gas-liquid interface. These particles enter the gas-liquid mixing zone and react with water molecules, with the products entering the liquid phase to form the final aqueous solution. In the upper chamber, plasma filaments are generated in bubbles near the needle tip. As the bubbles develop and burst, they are ignited onto the grounding electrode. This device can improve plasma utilization while generating more plasma, significantly increasing the yield of nitrogen-containing compounds.

[0025] 5. The gas-liquid mixed-phase discharge plasma device can efficiently decompose ethanol solution under mild conditions such as low temperature and normal pressure, significantly improving the hydrogen yield and increasing hydrogen production efficiency.

[0026] 6. The device features a compact structure and flexible operation, adapting to various reaction conditions and scales; it eliminates the need for combustion heating, reducing carbon emissions and providing a green and environmentally friendly hydrogen production solution.

[0027] 7. The generation or degradation of the main target product can be controlled by changing the composition of the reaction liquid, thus achieving multiple applications. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the device structure of this utility model.

[0030] Figure 2 This is a cross-sectional schematic diagram of the insulating plate, porous metal plate, and suspended electrode of this utility model.

[0031] Figure 3 This is a schematic diagram of the structure of the insulating board of this utility model.

[0032] Figure 4 This is a cross-sectional view of the porous metal plate of this utility model.

[0033] Figure 5 This is a schematic diagram of a porous metal plate structure with different numbers of holes according to this utility model.

[0034] In the diagram: 1. Pulse power supply; 2. Lower reaction chamber; 3. Insulating plate; 31. Groove; 32. Central hole; 4. Upper reaction chamber; 5. Air inlet; 6. High-voltage electrode plate; 7. Porous metal plate; 71. Vertical hole; 72. Vent hole; 8. Suspended electrode; 9. Sealing gasket; 10. Grounding electrode plate; 11. Grounding wire; 12. Gas storage device; 13. Air inlet flow meter; 14. Liquid storage tank at the lower reaction chamber end; 15. Circulation pump at the lower reaction chamber end. 6. Lower reaction chamber end valve; 17. Lower reaction chamber end flow meter; 18. Lower reaction chamber end outlet; 19. Lower reaction chamber end inlet; 20. Upper reaction chamber end liquid storage tank; 21. Upper reaction chamber end circulating pump; 22. Upper reaction chamber end valve; 23. Upper reaction chamber end flow meter; 24. Upper reaction chamber end outlet; 25. Upper reaction chamber end inlet; 26. Upper reaction chamber end gas outlet; 27. Gas outlet flow meter; 28. Separation device. Detailed Implementation

[0035] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. The present utility model will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this utility model or its application or use. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0039] In the description of this utility model, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0040] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0041] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0042] like Figure 1-5As shown, this utility model provides a suspended electrode gas-liquid mixed-phase discharge plasma generator, including a reactor body. The interior of the reactor body is a closed cavity, and an insulating plate 3 is provided in the middle of the closed cavity. A silicone gasket connects the upper and lower reaction chambers to the insulating plate 3. The closed cavity is divided by the insulating plate 3 into an upper reaction chamber 4 and a lower reaction chamber 2. A grounding electrode plate 10 is provided in the upper reaction chamber 4, and the grounding electrode plate 10 is connected to a ground wire 11. The upper reaction chamber 4 is connected to a liquid circulation section of the upper reaction chamber 4 located outside the reactor body. The upper reaction chamber 4 is also connected to a separation device 28 located outside the reactor body. The separation device 28 is used to collect and discharge reaction product gases. The separation device 28 can employ liquid absorption or gas absorption methods to adapt to different operating conditions and absorption requirements. The separation device 28 is connected to the upper reaction chamber 4 via the gas outlet 26 at the upper reaction chamber end. A gas outlet flow meter 27 is installed between the separation device 28 and the gas outlet. A high-voltage electrode plate 6 is installed in the lower reaction chamber 2. The high-voltage electrode plate 6 is connected to a pulse power supply 1 and a gas storage device 12 located outside the reactor body via a gas inlet 5. A gas inlet flow meter 13 is installed between the gas storage device and the gas inlet 5 to precisely control the flow of reaction gas into the reaction vessel. The lower reaction chamber 2 is connected to the liquid circulation section of the lower reaction chamber 2 located outside the reactor body. The centers of the high-voltage electrode plate 6, the suspended electrode 8, and the grounding electrode plate 10 are located on the same vertical line. The high-voltage electrode plate 6 can be circular or square, and the grounding electrode plate 10 corresponds to the shape of the high-voltage electrode plate 6. The pulse power supply 1 is connected to the high-voltage electrode plate 6 and the grounding electrode plate 10.

[0043] The upper surface of the insulating plate 3 is recessed downwards to form a groove 31, the depth of which exceeds that of the porous metal plate 7. A porous metal plate 7 is fixed to the upper part of the groove 31, and the periphery of the porous metal plate 7 is fixed to the insulating plate 3 by sealing gaskets 9. The sealing gaskets 9 can be annular gaskets made of polytetrafluoroethylene or silicone to meet sealing requirements under different working conditions. The holes in the porous metal plate 7 are axially symmetrically and uniformly distributed. The upper surface of the porous metal plate 7 is flush with the upper surface of the insulating plate 3. A suspended electrode 8 is disposed through the center of the porous metal plate 7. A central hole 32 is formed on the insulating plate 3 below the groove 31. The diameter of the central hole 32 is larger than the diameter of the suspended electrode 8, and the suspended electrode 8 does not contact the insulating plate 3.

[0044] The porous metal plate 7 has vertical holes 71 for placing the suspended electrode 8 and several vent holes 71 for gas flow. These vent holes 71 are inclined upwards towards the suspended electrode 8, and the angle between the vent holes 71 and the vertical line ranges from 0-30° to adjust the gas supply direction. The opening diameter of the vent holes 71 is 1-2 mm, and the number of openings is 2-18. The distance between the vertical holes 71 and the vent holes 71 is maintained within the range of 3-10 mm to ensure the uniformity of the gas flow entering the upper reaction chamber 4 and the stability of its function. The height of the gas buffer chamber between the lower surface of the porous metal plate 7 and the insulating plate 3 at the bottom of the groove 31 is greater than 1 mm. The function of the gas buffer chamber is to uniformly distribute the airflow. The liquid circulation section of the upper reaction chamber 4 includes an upper reaction chamber end outlet 24 and an upper reaction chamber end inlet 25 connected to the upper reaction chamber 4 at one end. The upper reaction chamber end outlet 24 is higher than the upper reaction chamber end inlet 25. The other end of the upper reaction chamber end outlet 24 is connected in sequence to the upper reaction chamber end circulation pump 21 and the upper reaction chamber end liquid storage tank 20. The other end of the upper reaction chamber end inlet 25 is connected in sequence to the upper reaction chamber end flow meter 23, the upper reaction chamber end valve 22, the upper reaction chamber end circulation pump 21, and the upper reaction chamber end liquid storage tank 20.

[0045] The liquid circulation section of the lower reaction chamber 2 includes a lower reaction chamber end outlet 18 and a lower reaction chamber end inlet 19 connected to the lower reaction chamber 2 at one end. The lower reaction chamber end outlet 18 is higher than the lower reaction chamber end inlet 19. The other end of the lower reaction chamber end outlet 18 is connected in sequence to the lower reaction chamber end circulation pump 15 and the lower reaction chamber end liquid storage tank 14. The other end of the lower reaction chamber end inlet 19 is connected in sequence to the lower reaction chamber end flow meter 17, the lower reaction chamber end valve 16, the lower reaction chamber end circulation pump 15, and the lower reaction chamber end liquid storage tank 14.

[0046] The circulation system ensures independent liquid circulation in both parts of the reaction chamber, achieving efficient exchange of reaction media and energy utilization. The liquid storage tank can be a closed-loop structure to prevent liquid evaporation. The liquid storage tank is connected to the circulation pump via PU tubing, which in turn connects to the inlet and outlet ports at the lower end of the upper reaction chamber 4, ensuring the stability and airtightness of the liquid circulation.

[0047] The discharge forms of the pulse power supply 1 include corona discharge, spark discharge, and arc discharge. The pulse power supply 1 can simultaneously achieve gas-liquid mixed-phase interface discharge and liquid phase discharge. The frequency of the pulse power supply 1 is 1Hz-20kHz, and the voltage of the pulse power supply 1 is 1-60kV. The cavity material of the reactor is any one of quartz, glass, polytetrafluoroethylene, and ceramic. The high-voltage electrode plate 6 and the ground electrode plate 10 are plate electrodes. The plate electrodes are provided with vent holes 71 with an opening diameter of 1-5mm. The suspended electrode 8 is a needle or rod electrode with both ends sharpened. The high-voltage electrode plate 6 is made of iron, tungsten, copper, carbon, or stainless steel, and the suspended electrode 8 is made of platinum, tungsten, copper, or stainless steel. The distance from the upper part of the suspended electrode to the porous metal plate 7 ranges from 3-10mm, and the distance from the lower part of the suspended electrode to the insulating plate is 0-10mm.

[0048] Preferably, the thickness of the annular layer in the reaction chamber is 1–6 mm. The flow rate of the reaction gas is 5–30 mL / min. The nitrogen fixation reaction liquid is pure water. The nanosecond pulse power supply is 30 kV and 10 Hz.

[0049] The method for nitrogen fixation according to this invention is as follows: It is implemented using a suspended electrode gas-liquid mixed-phase discharge plasma generator, wherein the reaction gas is pure nitrogen, air, or a mixture of nitrogen and oxygen. The reaction liquid is water, which can also be a mixture of water and alcohols, or a mixture of water and melamine compounds, to optimize the reaction effect and improve nitrogen fixation efficiency. Specifically, it includes the following steps:

[0050] S1. Connect the suspended electrode gas-liquid mixed phase discharge plasma generator and check the airtightness of the suspended electrode gas-liquid mixed phase discharge plasma generator. Set the voltage and current monitoring device to be connected to the pulse power supply 1.

[0051] S2. Nitrogen gas is injected into the reactor for 5 minutes through the gas storage device to remove air from the device and achieve gas washing of the suspended electrode gas-liquid mixed-phase discharge plasma generator.

[0052] S3. Control the nitrogen flow rate of the gas storage device to 10 mL / min through the flow meter. After continuous gas washing for 5 min, adjust the pulse power supply 1 according to the voltage and current monitoring device so that the frequency of the pulse power supply 1 is 10 Hz and the voltage amplitude is 20 kV. The suspended electrode gas-liquid mixed phase discharge plasma generator produces plasma for 5 min.

[0053] S4. Separate and detect the liquid in the reactor body and separation device 28 to obtain nitrogen fixation products.

[0054] The method for producing hydrogen according to this invention is as follows: It is achieved using a suspended electrode gas-liquid mixed-phase discharge plasma generator. The solution in the reactor is methanol, ethanol, or an organic solution, with an organic concentration of 5-100%. Specifically, it includes the following steps:

[0055] T1. Connect the suspended electrode gas-liquid mixed phase discharge plasma generator and check the airtightness of the suspended electrode gas-liquid mixed phase discharge plasma generator. Set the voltage and current monitoring device to be connected to the pulse power supply 1.

[0056] T2. Add ethanol solution to the reaction chamber through the water inlet 25 at the upper reaction chamber end and the water inlet 19 at the lower reaction chamber end. The height of the reaction liquid in the lower reaction chamber 2 is higher than that of the high voltage electrode plate 6, and the height of the reaction liquid in the upper reaction chamber 4 is higher than that of the upper end of the suspension electrode 8. The volume fraction concentration of the reaction liquid is 5-100%.

[0057] T3. Inject argon gas into the reactor for 5 minutes through the gas storage device to remove air from the device, thereby replacing and washing the suspended electrode gas-liquid mixed-phase discharge plasma generator; control the argon gas flow rate of the gas storage device to be 5-500 mL / min through the inlet flow meter 13.

[0058] T4. Adjust the pulse power supply 1 according to the voltage and current monitoring device so that the frequency of the pulse power supply 1 is 5Hz-20kHz and the voltage amplitude is 10-100kV; generate plasma by gas-liquid mixed-phase discharge of the suspended electrode; measure the gas flow rate through the flow meter and collect the generated hydrogen during the reaction.

[0059] This invention can be used for nitrogen fixation or hydrogen production. Its key features include simultaneous discharge from two needle-plate reactors with different discharge modes; separation of the discharge zone and gas flow zone to reduce gas flow interference; discharge at both ends of the suspended electrode 8, with part of the suspended electrode 8 submerged in liquid for cooling and reduced electrode wear. For nitrogen fixation, only nitrogen / air and water are used as raw materials, eliminating the need for hydrogen discharge. The plasma in this device can be generated simultaneously at the gas-liquid interface and in the bubbles, improving nitrogen fixation efficiency, increasing product concentration, and reducing energy consumption. Furthermore, the presence of liquid allows the generated nitrogen oxides to dissolve directly in the liquid phase, producing NO3. - NO2 - and NH4 + It exists in the liquid phase and promotes the formation and fixation of nitrogen oxides in the gas phase.

[0060] This invention enables simultaneous gas-liquid interface discharge and liquid-phase discharge modes, significantly improving energy utilization efficiency, expanding the production range of products, and enhancing the overall energy efficiency of the system. The device employs a design where discharge occurs at both ends of the tip of the suspended electrode 8 within the reactor, enhancing the energy density and reactivity of the discharge region. The lower end of the reaction chamber concentrates the airflow through a small-scale ventilation structure near the tip, maintaining continuous and slow gas flow and exchange within the discharge plasma region. Gas enters the upper end of the reaction chamber through a porous structure and exits near the upper electrode, ensuring effective gas exchange between the discharge region and the airflow into the plasma region. Simultaneously, the upper part of the suspended electrode 8 is immersed in the liquid, serving as a cooling electrode and effectively reducing the wear of the suspended electrode 8 while promoting liquid-phase discharge. This design realizes the application potential of pulsed suspended electrode 8 plasma gas-liquid mixed-phase discharge technology in the fields of efficient nitrogen fixation and hydrogen production.

[0061] The needle-shaped suspended electrode of this invention is placed between two parallel plate electrodes, but the voltage is applied through the two plate electrodes. Without the inserted insulating plate and needle-shaped suspended electrode, the device's electric field is a plate electric field with a relatively large distribution area, uniform but weak. After inserting the insulating plate and needle-shaped suspended electrode, the insulating plate provides electrical isolation, while the needle-shaped suspended electrode concentrates and conducts the electric field, thus changing the parallel electric field distribution to a locally concentrated electric field, with the field distribution becoming hourglass-shaped. A strong field region is formed near the needle-shaped suspended electrode; this localized strong field is beneficial for increasing ionization, forming high-density plasma, and enhancing nitrogen fixation and hydrogen production.

[0062] Example 1

[0063] A suspended electrode gas-liquid mixed-phase discharge plasma generator for nitrogen fixation includes an upper reaction chamber 4 and a lower reaction chamber 2, a pulse power supply 1, a high-voltage electrode plate 6, a suspended electrode 8, a grounded electrode plate 10, a gas storage device 12, liquid circulation devices 15 and 19, and a separation device 28 for nitride absorption.

[0064] The reaction chamber includes a lower reaction chamber 2 and an upper reaction chamber 4. A grounding electrode plate 10 and a high-voltage electrode plate 6 are fixed at the upper and lower ends of the reaction chamber, respectively. The high-voltage electrode plate 6 has an air inlet in the middle. The lower reaction chamber 2 has a lower reaction chamber end outlet 18 and a lower reaction chamber end inlet 19 for circulating the liquid at the lower end. The upper reaction chamber 4 includes a grounding electrode plate 10, an upper reaction chamber end outlet 24, and an upper reaction chamber end inlet 25. The lower end of the upper reaction chamber is isolated by an insulating plate 3. The insulating plate 3 has a hole in the center, and a porous metal plate 7 is fixed in the middle using a polytetrafluoroethylene gasket. A suspended electrode 8 that penetrates the insulating plate is fixed in the middle hole of the metal plate. Rubber sealing gaskets are provided between the upper and lower end plates and the reactor body for sealing. In this embodiment, the reactor is made of quartz. The upper chamber 4 has a height of 14mm, the lower chamber 2 has a height of 20mm, and the inner diameter of the chambers is 35mm. The upper and lower end plates are connected by bolts to press them onto the reactor body to achieve a fixed connection between the upper and lower end plates and the double-pass pipe. The plate electrode is made of stainless steel plate with a diameter of 60mm. The metal porous plate 7 has a diameter of 20mm, and there are 8 vent holes 72. The center hole is 5mm from the edge, and the opening angle is 15° off-axis. The needle electrode can be a platinum needle electrode with a diameter of 1mm and a length of 8mm, and the needle electrode is fixed with silicone sealant. The closed chamber of the reactor is equipped with a nitrogen fixation reaction. The pure water level is higher than the high-voltage electrode plate 6 and the suspension electrode 8, respectively. The liquid volumes in the upper and lower reaction chambers are maintained at 7 mL and 10 mL, respectively. When adding pure water, it enters the lower reaction chamber 2 and the upper reaction chamber 4 through the lower inlet 19 and the upper inlet 25. The liquid in the lower reaction chamber 2 and the upper reaction chamber 4 is circulated by the circulation pump 15 at the lower reaction chamber end and the circulation pump 21 at the upper reaction chamber end at the upper reaction chamber end at a circulation speed of 5 mL / min. The liquid storage tank 14 at the lower reaction chamber end and the liquid storage tank 20 at the upper reaction chamber end are used to store and circulate the reaction liquid. The high-voltage electrode plate 6 is connected to the pulse power supply 1, and the grounding electrode plate 10 is connected to the ground wire 11.

[0065] The gas storage device 12 stores nitrogen gas. The gas storage device 12 is connected to the air inlet 5 through a pipeline. The flow meter 13 is installed between the gas storage device 12 and the air inlet 5. Specifically, the gas storage device 12 is generally a nitrogen cylinder used to store the raw material gas for the ammonia synthesis reaction. The gas storage device 12, the flow meter 13 and the air inlet 5 are connected in sequence through a PU gas pipe. The flow meter 13 is used to monitor the flow rate of the raw material gas.

[0066] The separation device 28 is connected to the upper gas outlet 26 through a pipeline. Specifically, in this embodiment, the upper reaction chamber 4 is provided with an upper gas outlet 26. The gas outlet 26 is connected to the flow meter 27 and the separation device 28 through a pipeline. The separation device 28 contains 20 mL of pure water absorption liquid. The gas outlet of the pipeline is submerged in the absorption liquid. The gas generated after the reaction in the reactor enters the absorption liquid in the absorption device 28 and is absorbed by the absorption liquid to fix nitrogen products.

[0067] Ammonia is obtained by separating the absorbent in the absorption device 28; after the reaction stabilizes, pure water in the lower part of the upper reaction chamber is collected, and the concentration of nitrogen fixation product is determined by spectrophotometry.

[0068] The ammonia concentration can be calculated, and the NH3 yield of the gas-liquid mixed-phase discharge plasma ammonia production device disclosed in this invention can be deduced to be 3.9 mg / h and 0.041 g / kWh, respectively, and the NO3 yield is also calculated to be... - The yield and energy efficiency were 95.051 mg / h and 1.18 g / kWh, respectively, and NO2... - The yield and energy efficiency were 27.313 mg / h and 0.34 g / kWh, respectively. The total nitrogen fixation energy efficiency was 1.88 g / kWh, which is much higher than the 0.78 g / kWh of the traditional needle-plate reactor, indicating that this method has a significant nitrogen fixation effect.

[0069] Example 2

[0070] A suspended electrode gas-liquid mixed-phase discharge plasma generator for hydrogen production includes an upper reaction chamber 4 and a lower reaction chamber 2, a pulse power supply 1, a high-voltage electrode plate 6, a suspended electrode 8, a grounded electrode plate 10, a gas storage device 12, a flow meter 13, and a separation device 28.

[0071] The reaction chamber includes a lower reaction chamber 2 and an upper reaction chamber 4. The lower ends of the upper reaction chamber are respectively fixed with a grounding electrode plate 10 and a high-voltage electrode plate 6. The high-voltage electrode plate 6 has an air inlet in the middle. The lower reaction chamber 2 has a lower water inlet 19. The upper reaction chamber 4 includes a grounding electrode plate 10 and an upper water inlet 25. The lower end of the upper reaction chamber is isolated by an insulating plate 3. The insulating plate 3 has a hole in the center, and a porous metal plate 7 is fixed in the middle by a polytetrafluoroethylene gasket. A suspended electrode 8 that penetrates the insulating plate is fixed in the middle hole of the metal plate. Rubber sealing gaskets are provided between the upper and lower end plates and the reactor body for sealing. In this embodiment, the reactor is made of quartz. The height of the upper chamber 4 is 14mm, the height of the lower chamber 2 is 20mm, and the inner diameter of the chambers is 35mm. The upper and lower end plates are pressed onto the reactor body by bolts to achieve a fixed connection between the upper and lower end plates and the double-pass pipe. The plate electrode is made of stainless steel plate with a diameter of 60mm. The diameter of the metal perforated plate 7 is 20mm, the number of vent holes 72 is 8, the distance from the center hole to the edge is 5mm, and the opening angle is 0° off-axis. The needle electrode can be a platinum needle electrode with a diameter of 1mm and a length of 8mm, and the needle electrode is fixed by silicone sealant. The closed cavity of the reactor contains an 80% ethanol aqueous solution. The liquid level of the alcohol-water solution is higher than that of the high-voltage electrode plate 6 and the suspension electrode 8, respectively. The liquid volumes in the upper and lower reaction chambers are maintained at 7 mL and 10 mL, respectively. When adding the ethanol-water solution, it enters the lower reaction chamber 2 and the upper reaction chamber 4 through the lower inlet 19 and the upper inlet 25. The liquid in the lower reaction chamber 2 and the upper reaction chamber 4 is circulated by the circulation pump 15 at the lower reaction chamber end and the circulation pump 21 at the upper reaction chamber end, with a circulation speed of 5 mL / min. The liquid storage tank 14 at the lower reaction chamber end and the liquid storage tank 20 at the upper reaction chamber end are used to store and circulate the reaction liquid. The high-voltage electrode plate 6 is connected to the pulse power supply 1, and the grounding electrode plate 10 is connected to the ground wire 11.

[0072] The gas storage device 12 stores argon gas. The gas storage device 12 is connected to the air inlet 5 through a pipeline. The flow meter 13 is installed between the gas storage device 12 and the air inlet 5. Specifically, the gas storage device 12 is generally an argon cylinder used to store inert gas. The gas storage device 12, the flow meter 13 and the air inlet 5 are connected in sequence through a PU gas pipe. The flow meter 13 is used to monitor the flow rate of the raw material gas.

[0073] The separation device 28 is connected to the upper gas outlet 26 and the gas outlet flow meter 27 via pipelines. Specifically, in this embodiment, the upper reaction chamber 4 is provided with an upper gas outlet 26, which is connected to the gas outlet flow meter 27 and the separation device 28 via pipelines. The gas generated after the reaction in the reactor enters the separation device 28 and the hydrogen production product is collected by the gas collection bag.

[0074] Argon gas is injected into the reactor for 5 minutes through a gas storage device to purge the air from the device and achieve gas purification, and then discharge is performed; the frequency of the pulse power supply is 10Hz, the voltage of the pulse power supply is 20kV, and the nitrogen flow rate is 10mL / min; the reaction time can be continuous.

[0075] Hydrogen is obtained by separating the metered gas using the separation device 28.

[0076] The hydrogen production concentration can be calculated, and the hydrogen yield of the gas-liquid mixed-phase discharge plasma hydrogen production device disclosed in this invention can be deduced to be 120 mL / min, with an energy consumption of 3.6 kW·h / m³. 3 -H2, indicating that this method has a significant hydrogen production effect, far less than the energy consumption of 5.8 kWh / m² for traditional plate-hole-plate hydrogen production. 3 -H2.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A suspended electrode gas-liquid mixed-phase discharge plasma generator, characterized in that: The reactor includes a reactor body, the interior of which is a closed cavity. An insulating plate is installed in the middle of the closed cavity, dividing the closed cavity into an upper reaction chamber and a lower reaction chamber. A grounding electrode plate is installed in the upper reaction chamber and connected to a ground wire. The upper reaction chamber is connected to an upper reaction chamber liquid circulation section located outside the reactor body and to a separation device located outside the reactor body. A high-voltage electrode plate is installed in the lower reaction chamber and connected to a pulse power supply and a gas storage device located outside the reactor body through an air inlet. The lower reaction chamber is connected to the lower reaction chamber liquid circulation section located outside the reactor body. The upper surface of the middle part of the insulating plate is recessed downward to form a groove. A perforated metal plate is fixed at the upper part of the groove. The upper surface of the perforated metal plate is flush with the upper surface of the insulating plate. A floating electrode is disposed through the center of the perforated metal plate. A central hole is opened on the insulating plate at the lower part of the groove.

2. The suspended electrode gas-liquid mixed-phase discharge plasma generator according to claim 1, characterized in that: The liquid circulation section of the upper reaction chamber includes an upper reaction chamber end outlet and an upper reaction chamber end inlet connected to the upper reaction chamber at one end. The upper reaction chamber end outlet is higher than the upper reaction chamber end inlet. The other end of the upper reaction chamber end outlet is connected in sequence to an upper reaction chamber end circulation pump and an upper reaction chamber end liquid storage tank. The other end of the upper reaction chamber end inlet is connected in sequence to an upper reaction chamber end flow meter, an upper reaction chamber end valve, an upper reaction chamber end circulation pump, and an upper reaction chamber end liquid storage tank. The lower reaction chamber liquid circulation section includes a lower reaction chamber end outlet and a lower reaction chamber end inlet connected to the lower reaction chamber at one end. The lower reaction chamber end outlet is higher than the lower reaction chamber end inlet. The other end of the lower reaction chamber end outlet is sequentially connected to the lower reaction chamber end circulation pump and the lower reaction chamber end liquid storage tank. The other end of the lower reaction chamber end inlet is sequentially connected to the lower reaction chamber end flow meter, the lower reaction chamber end valve, the lower reaction chamber end circulation pump, and the lower reaction chamber end liquid storage tank.

3. The suspended electrode gas-liquid mixed-phase discharge plasma generator according to claim 1, characterized in that, The separation device is connected to the upper reaction chamber through the gas outlet at the upper reaction chamber end, and a gas outlet flow meter is installed between the separation device and the gas outlet. An inlet flow meter is installed between the gas storage device structure and the inlet.

4. The suspended electrode gas-liquid mixed-phase discharge plasma generator according to claim 1, characterized in that, The porous metal plate has vertical holes for placing the suspended electrode and several vent holes for gas flow. The several vent holes are inclined from bottom to top towards the suspended electrode. The angle between the several vent holes and the vertical line is in the range of 0-30°. The height of the gas buffer cavity between the lower surface of the porous metal plate and the insulating plate at the bottom of the groove is greater than 1mm.

5. The suspended electrode gas-liquid mixed-phase discharge plasma generator according to claim 1, characterized in that, The discharge modes of the pulse power supply include corona discharge, spark discharge, and arc discharge. The pulse power supply can simultaneously realize gas-liquid mixed-phase interface discharge and liquid phase discharge.

6. The suspended electrode gas-liquid mixed-phase discharge plasma generator according to claim 1, characterized in that, The reactor cavity is made of any one of the following materials: quartz, glass, polytetrafluoroethylene, and ceramic.

7. The suspended electrode gas-liquid mixed-phase discharge plasma generator according to claim 1, characterized in that, The high-voltage electrode plate and the grounding electrode plate are plate electrodes, and the plate electrodes are provided with ventilation holes; the suspended electrode is a needle or rod electrode with both ends sharpened.

8. The suspended electrode gas-liquid mixed-phase discharge plasma generator according to claim 1, characterized in that, The diameter of the central hole is larger than the diameter of the suspended electrode, and the suspended electrode does not contact the insulating plate; the height of the lower part of the suspended electrode is equal to or lower than the height of the insulating plate.

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