Micro-plasma gas-solid catalytic reaction device

Abstract

The present application relates to a kind of micro plasma gas-solid catalytic reaction device.The device includes reactor, and the reactor has reaction cavity inside, and the reactor is provided with gas inlet.Reaction cavity is provided with micro plasma electrode structure, and the micro plasma electrode structure includes insulating base body, and at least two electrodes are arranged on the insulating base body for ionizing gas to form plasma.The insulating base body is provided with solid catalyst.Electrode ionizes reaction gas to form plasma, combined with catalyst, to realize the catalytic reaction of gas under micro plasma condition.Heating structure is arranged in reaction cavity;The micro plasma gas-solid catalytic reaction device further includes plasma power supply and heating power supply.Reactor is provided with vacuum connection pipe and gas outlet in communication with reaction cavity, vacuum connection pipe is connected with vacuum pump, vacuum gauge and pressure gauge, and back pressure valve is arranged at gas outlet, can adjust the pressure in reaction cavity, so that reaction cavity is in vacuum or at normal pressure or greater than one atmosphere.

Description

Technical Field

[0001] This invention relates to the field of catalytic reactors, and more specifically to a gas-solid catalytic reaction device that combines gas and catalyst under micro-plasma conditions. Background Technology

[0002] Currently, gases such as nitrogen, carbon dioxide, and methane are stable, but their conversion into other products through catalytic reactions requires stringent conditions. For example, the synthesis of ammonia requires converting N2 to NH3 at high temperatures (300–500℃) and high pressures (20–30 MPa). Plasma can ionize gases at room temperature and pressure, producing ions and active groups, allowing stable molecules to react under milder conditions. However, chemical reactions under pure plasma conditions have low efficiency and poor selectivity. By adding a catalyst to the discharge region, the combined advantages of plasma and catalysis can be utilized, improving conversion rate and selectivity while providing milder reaction conditions, longer catalyst lifetime, and higher efficiency. Micro-plasma reduces the discharge region to the micrometer scale, resulting in better stability. Currently, there are no reaction devices that combine micro-plasma with a catalyst. Summary of the Invention

[0003] The purpose of this invention is to provide a micro-plasma gas-solid catalytic reaction device.

[0004] To achieve the above objectives, the present invention provides a micro-plasma gas-solid catalytic reaction device with the following technical solution: A micro-plasma gas-solid catalytic reaction device includes a reactor, the reactor having a reaction chamber inside, and an inlet on the reactor communicating with the reaction chamber. The inlet is used to communicate with a gas source to allow the gas to be reacted to enter. A micro-plasma electrode structure is provided in the reaction chamber, the micro-plasma electrode structure including an insulating substrate, at least two electrodes being provided on the insulating substrate for ionizing gas to form plasma; a solid catalyst is provided on the insulating substrate; a heating structure is provided in the reaction chamber; the micro-plasma gas-solid catalytic reaction device further includes a plasma power supply for supplying power to each electrode and a heating power supply for supplying power to the heating structure; a vacuum connection pipe communicating with the reaction chamber and an outlet are provided on the reactor, the vacuum connection pipe being connected to a vacuum pump, a vacuum gauge and a pressure gauge, and a back pressure valve is provided at the outlet to regulate the pressure in the reaction chamber.

[0005] The electrode includes a first electrode and a second electrode, which are disposed on the same side of the insulating substrate.

[0006] The electrode includes a first electrode and a second electrode, which are respectively disposed on two different sides of the insulating substrate.

[0007] The minimum distance between the first electrode and the second electrode is 1 μm–10 mm.

[0008] The electrode includes a first electrode, a second electrode, and a third electrode. The first electrode and the second electrode are disposed on the same side of the insulating substrate, and the first electrode and the third electrode are disposed on two different sides of the insulating substrate, respectively.

[0009] The heating structure includes a ceramic heating element.

[0010] The insulating substrate is composed of quartz and / or silicon wafers, and the heating structure includes an electric heating element disposed on the insulating substrate.

[0011] A window is provided above the micro-plasma electrode structure on the reactor. A window plate is sealed at the window. A spectrometer is provided above the window. The spectrometer can collect ultraviolet-visible and infrared spectra in the micro-plasma gas-solid catalytic reaction through the window plate.

[0012] The window is made of one of the following materials: quartz, sapphire, potassium bromide, zinc selenide, calcium fluoride, or sodium chloride.

[0013] The reactor's outlet is connected to a mass spectrometer or a gas chromatograph.

[0014] The beneficial effects of this invention are as follows: The gas to be reacted enters the reaction chamber through the inlet. After connecting the electrodes and the plasma power supply, the plasma power supply ionizes the reactant gas to form plasma. Combined with the catalyst, this achieves a catalytic reaction of the gas under micro-plasma conditions. Through the heating structure and heating power supply, the co-catalytic effect of plasma and catalyst on the gas can be achieved under different temperature conditions. A vacuum pump and vacuum gauge can maintain different vacuum levels in the reaction chamber. When the reaction chamber needs to be at atmospheric pressure or positive pressure, the vacuum pump stops working. By adjusting the pressure of the gas source in conjunction with the back pressure valve, the pressure in the reaction chamber can be made greater than or equal to one atmosphere, and this pressure is detected by a pressure gauge. It has multiple functions and is easy to use. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a micro-plasma gas-solid catalytic reaction device according to an embodiment of the present invention;

[0016] Figure 2 yes Figure 1 Schematic diagram of the reactor structure;

[0017] Figure 3 yes Figure 2 A magnified view of a section at point A in the middle;

[0018] Figure 4 This is a schematic diagram of the micro-plasma electrode structure in Embodiment 2 of the micro-plasma gas-solid catalytic reaction device of the present invention;

[0019] Figure 5 This is a schematic diagram of the micro-plasma electrode structure in Embodiment 3 of a micro-plasma gas-solid catalytic reaction device of the present invention;

[0020] Explanation of reference numerals in the attached figures: 1. Gas source; 2. Plasma power supply; 3. Heating power supply; 4. Vacuum pump; 5. Vacuum gauge and pressure gauge; 6. Reactor; 7. Reaction chamber; 8. Upper shell; 9. Lower shell; 10. Inlet pipe; 11. Electrode wire; 12. Thermocouple wire; 13. Heating wire; 14. Vacuum connection pipe; 15. Outlet pipe; 16. Ceramic heating element; 17. Micro-plasma electrode structure; 18. Window; 19. Window plate; 20. Insulating substrate; 21. First electrode; 22. Second electrode; 23. Solid catalyst; 24. Third electrode. Detailed Implementation

[0021] To facilitate understanding of the present invention, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0022] It should be noted that, unless otherwise defined, the technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The use of "belonging" in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0023] Example 1 of a micro-plasma gas-solid catalytic reaction device of the present invention, as follows: Figures 1-3 As shown, the reactor includes a reactor 6, which has a reaction chamber 7 inside. Specifically, the reactor includes an upper shell 8 and a lower shell 9, which are sealed together, and the inner cavities of the upper and lower shells together form the reaction chamber. The reactor is provided with an air inlet communicating with the reaction chamber. The air inlet is used to connect with a gas source 1 to allow the gas to be reacted to enter. The gas source is a pressurized gas cylinder. The gas source can be one or more gases, such as nitrogen, hydrogen, carbon dioxide, methane, ammonia, etc.

[0024] A micro-plasma electrode structure 17 is provided in the reaction chamber 7. The micro-plasma electrode structure includes an insulating substrate 20, on which two electrodes are disposed for ionizing gas to form plasma. The two electrodes are a first electrode 21 and a second electrode 22, and the first and second electrodes are disposed on the same side of the insulating substrate. The shortest distance between the first and second electrodes is 1μm–10mm, and the shortest distance refers to the distance between the points where the first and second electrodes are closest. The insulating substrate is composed of quartz and silicon wafers. The first and second electrodes are fixed on the insulating substrate, and a fixed catalyst 23 is disposed on the insulating substrate between the first and second electrodes. In this embodiment, the fixed catalyst is disposed on the insulating substrate by coating.

[0025] A heating structure 16 is provided in the reaction chamber. In this embodiment, the heating structure is a ceramic heating element. In other embodiments, the heating structure can also be an electric heating element disposed on an insulating substrate. The micro-plasma gas-solid catalytic reaction device also includes a plasma power supply 2 for supplying power to each electrode and a heating power supply 3 for supplying power to the heating structure. The plasma power supply can be an AC high-voltage power supply with a frequency of 1–100 kHz and a peak voltage of 0–50 kV, or a DC pulse power supply with a frequency of 1–100 kHz and a peak voltage of 0–50 kV, or a DC power supply of 0–10 kV. The setting of the heating structure and heating power supply can complete the co-catalytic effect of plasma and catalyst on gas under conditions between room temperature and 500°C. A vacuum connection pipe 14 is provided on the reactor, which is connected to the reaction chamber. The vacuum connection pipe 14 is connected to a vacuum pump 4. A vacuum gauge and a pressure gauge 5 are also provided on the vacuum connection pipe. A back pressure valve is provided at the gas outlet to adjust the pressure in the reaction chamber. In this embodiment, the pressure in the reaction chamber can be maintained at 10 kV. –3 The pressure can be adjusted between mbar and 2000 mbar to achieve gas-solid catalytic reactions under micro-plasma discharge conditions at different pressures. Specifically, when a vacuum condition is required in the reaction chamber, such as 10... –3 For pressures between mbar and 1000 mbar, a vacuum pump needs to be turned on to evacuate the gas, and a vacuum gauge should be used for measurement. When the reaction chamber needs to be at or above one atmosphere, such as 1000 mbar to 2000 mbar, the back pressure valve needs to be adjusted through a pressure cylinder to regulate the pressure, and a pressure gauge should be used for measurement.

[0026] A thermocouple is installed in the reaction chamber for real-time temperature monitoring. An inlet pipe 10 is located at the inlet of the reaction chamber, and an outlet pipe 15 is installed on the reactor, communicating with the reaction chamber. The outlet pipe 15 is connected to a mass spectrometer or gas chromatograph for product detection. The reactor also has electrode conduits 11 for cables connecting electrodes and the plasma power supply, thermocouple conduits 12 for thermocouple cables, and heating conduits 13 for cables of the heating structure. A window 18 is located above the micro-plasma electrode structure on the reactor, and a sealed window plate 19 is installed at the window. In this embodiment, the window plate is made of one of the following materials: quartz, sapphire, potassium bromide, zinc selenide, calcium fluoride, or sodium chloride. A spectrometer is located above the window, and the spectrometer can collect ultraviolet-visible and infrared spectra of the micro-plasma gas-solid catalytic reaction through the window plate. Quartz or sapphire windows can be used to collect the ultraviolet and visible spectra of the catalyst in the microplasma region; potassium bromide, zinc selenide, calcium fluoride, or sodium chloride windows can be used to collect the infrared spectra of the catalyst in the microplasma region.

[0027] The following detailed explanation uses specific experimental examples.

[0028] Example 1

[0029] 1) Iron-based catalyst powder for ammonia synthesis is coated on an insulating substrate and connected to a first electrode and a second electrode on the same side with a distance of 1 μm between the two electrodes, forming a micro-plasma electrode structure.

[0030] 2) Place the micro-plasma electrode structure into the reaction chamber, connect each electrode to the plasma power supply, and connect the heating structure and the heating power supply.

[0031] 3) Use a quartz window to seal the reaction chamber so that the micro-plasma discharge region faces the window.

[0032] 4) The heating structure is heated by a heating power source. After the catalyst is reduced, the temperature of the heating element is adjusted to 500℃.

[0033] 5) Nitrogen and hydrogen enter the reaction chamber through the inlet, and the opening of the outlet valve is adjusted to make the internal pressure normal.

[0034] 6) Connect the electrode plates to an AC high-voltage power supply with a peak voltage of 0–50kV and a frequency of 1–100kHz via electrode wires. Set the power supply frequency to 10kHz and the peak voltage to 50kV.

[0035] 7) Connect the window to the UV-Vis spectrometer to collect UV and visible spectra, and connect the mass spectrometer at the gas outlet for product detection.

[0036] Example 2

[0037] 1) The iron-based catalyst powder from ammonia decomposition is coated on an insulating substrate and connected to the first and second electrodes on the same side with a distance of 10 mm between the two electrodes, forming a micro-plasma electrode structure.

[0038] 2) Place the micro-plasma electrode structure into the reaction chamber, connect each electrode to the plasma power supply, and connect the heating structure and the heating power supply.

[0039] 3) Use a potassium bromide window to seal the reaction chamber so that the micro-plasma discharge region faces the window.

[0040] 4) The heating structure is heated by a heating power source. After the catalyst is reduced, the temperature of the heating element is adjusted to 500℃.

[0041] 5) Ammonia gas enters the reaction chamber through the inlet, and the opening of the outlet valve is adjusted to bring the internal pressure to normal.

[0042] 6) Connect the electrode sheet to a 100kHz, 50kV pulse DC power supply via electrode wires, and set the power supply to 100kHz, 50kV.

[0043] 7) Connect the window to the infrared spectrometer to collect infrared spectra, and connect the gas chromatograph to the gas outlet for product detection.

[0044] Example 3

[0045] 1) A platinum-based catalyst powder of carbon dioxide dry reforming is coated on an insulating substrate, and a first electrode and a second electrode that are not in the same plane are connected. The electrode spacing is the insulating substrate (quartz plate), and the thickness of the insulating substrate is 10 μm. This forms a micro-plasma electrode structure.

[0046] 2) Place the micro-plasma electrode structure into the reaction chamber, connect each electrode to the plasma power supply, and connect the heating structure and the heating power supply.

[0047] 3) Use a sapphire window to seal the reaction chamber so that the micro-plasma discharge region faces the window.

[0048] 4) The heating structure is heated by a heating power source. After the catalyst is reduced, the temperature of the heating element is adjusted to 300℃.

[0049] 5) Carbon dioxide and methane enter the reaction chamber through the inlet, and the opening of the outlet valve is adjusted to make the internal pressure 2000mbar.

[0050] 6) Connect the electrode plates to an AC high-voltage power supply with a peak voltage of 0–50kV and a frequency of 1–100kHz via electrode wires. Set the power supply to 1kHz and 50kV.

[0051] 7) Connect the window to the UV-Vis spectrometer to collect UV-Vis spectra, and connect the gas chromatograph to the gas outlet for product detection.

[0052] Example 4

[0053] 1) A nickel-based catalyst powder of carbon dioxide and methane dry reforming is coated on an insulating substrate and connected to a first electrode and a second electrode in the same plane with an electrode spacing of 1 μm, forming a micro-plasma electrode structure.

[0054] 2) Place the micro-plasma electrode structure into the reaction chamber, connect each electrode to the plasma power supply, and connect the heating structure and the heating power supply.

[0055] 3) The reaction chamber is sealed with a zinc selenide window, and the micro-plasma discharge area faces the window.

[0056] 4) The heating structure is heated by a heating power source. After the catalyst is reduced, the temperature of the heating element is adjusted to 500℃.

[0057] 5) Carbon dioxide and methane enter the reaction chamber through the inlet. Adjust the opening of the outlet valve to make the internal pressure 10. -1 mbar.

[0058] 6) Connect the electrode plates to an AC high-voltage power supply with a peak voltage of 0–50kV and a frequency of 1–100kHz via electrode wires. Set the power supply to 10kHz and 1kV.

[0059] 7) Connect the window to the infrared spectrometer to collect infrared spectra, and connect the gas chromatograph to the gas outlet for product detection.

[0060] Example 5

[0061] 1) The iron-based catalyst powder for ammonia synthesis is coated on an insulating substrate and connected to the first and second electrodes on the same surface with a spacing of 1 μm between the electrodes.

[0062] 2) Place the micro-plasma electrode structure into the reaction chamber, connect each electrode to the plasma power supply, and connect the heating structure and the heating power supply.

[0063] 3) The reaction chamber is sealed with a calcium fluoride window, and the micro-plasma discharge area is directly opposite the window.

[0064] 4) The heating structure is heated by a heating power source. After the catalyst is reduced, the temperature of the heating element is adjusted to room temperature.

[0065] 5) Carbon dioxide and methane enter the reaction chamber through the inlet. Adjust the opening of the outlet valve to make the internal pressure 10. -2 mbar.

[0066] 6) Connect the electrode plates to a 1–100kHz AC high-voltage power supply with a peak voltage of 0–50kV via electrode wires.

[0067] 7) Connect the window to the infrared spectrometer to collect infrared spectra, and connect the gas chromatograph to the gas outlet for product detection.

[0068] Example 6

[0069] 1) Iron-based catalyst powder for ammonia synthesis is coated on an insulating substrate and connected to a first electrode and a second electrode on the same plane with a spacing of 1 μm, forming a micro-plasma electrode structure.

[0070] 2) Place the micro-plasma electrode structure into the reaction chamber, connect each electrode to the plasma power supply, and connect the heating structure and the heating power supply.

[0071] 3) The reaction chamber is sealed with a sodium chloride window, and the micro-plasma discharge region is directly opposite the window.

[0072] 4) The heating structure is heated by a heating power source. After the catalyst is reduced, the temperature of the heating element is adjusted to 500℃.

[0073] 5) Carbon dioxide and methane enter the reaction chamber through the inlet. Adjust the opening of the outlet valve to make the internal pressure 10. -3 mbar.

[0074] 6) Connect the electrode plates to a 1–100kHz AC high-voltage power supply with a peak voltage of 0–50kV via electrode wires.

[0075] 7) Connect the window to the infrared spectrometer to collect infrared spectra, and connect the gas chromatograph to the gas outlet for product detection.

[0076] Example 2 of the micro-plasma gas-solid catalytic reaction device of the present invention, as follows: Figure 4 As shown, the difference from Embodiment 1 lies in the different structure of the micro-plasma electrode, as follows: the electrode includes a first electrode and a second electrode, which are respectively disposed on two different sides of the insulating substrate.

[0077] Example 3 of the micro-plasma gas-solid catalytic reaction device of the present invention, as follows: Figure 5 As shown, the difference from Embodiment 1 lies in the different structures of the micro-plasma electrode. In Embodiment 1, the micro-plasma electrode structure is a 2-electrode structure, while in Embodiment 3, the micro-plasma electrode structure is a 3-electrode structure, as follows: The electrode includes a first electrode, a second electrode, and a third electrode. The first electrode and the second electrode are disposed on the same side of the insulating substrate, while the first electrode and the third electrode are disposed on two different sides of the insulating substrate.

[0078] This application involves three different microplasma electrode structures, which enable switching between discharge modes to conduct catalytic reactions under different discharge modes. For example, two electrodes placed on the same side can produce glow discharge and arc discharge under different pressures, while two electrodes placed on different sides can achieve dielectric barrier discharge. This further enhances the functionality of the device in this application.

[0079] In the foregoing description of this specification, unless otherwise expressly specified and limited, the terms "fixed," "installed," "connected," or "linked" should be interpreted broadly. For example, the term "linked" can refer to a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can refer to the internal communication of two components or the interaction between two components. Therefore, unless otherwise expressly limited in this specification, those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0080] Based on the above description in this specification, those skilled in the art will also understand that terms used, such as "upper," "lower," "front," "rear," "left," "right," "length," "width," "thickness," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," "center," "longitudinal," "transverse," "clockwise," or "counterclockwise," are terms indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings of this specification. They are only for the purpose of facilitating the explanation of the present invention and simplifying the description, and do not imply that the devices or elements involved must have the specific orientation, or be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms should not be understood or interpreted as limitations on the present invention.

[0081] Furthermore, the terms "first" or "second," etc., used in this specification to refer to numbers or ordinal numbers are for descriptive purposes only and should not be construed as indicating, explicitly or implicitly, relative importance or specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this specification, "a plurality of" means at least two, such as two, three, or more, unless otherwise explicitly specified.

Claims

1. A micro-plasma gas-solid catalytic reaction device, characterized in that: The device includes a reactor with a reaction chamber inside. An inlet connected to the reaction chamber is provided on the reactor for connecting to a gas source to allow the gas to be reacted to enter. A micro-plasma electrode structure is provided within the reaction chamber. The micro-plasma electrode structure includes an insulating substrate with at least two electrodes on the substrate for ionizing gas to form plasma. A solid catalyst is placed on the insulating substrate. A heating structure is provided within the reaction chamber. The micro-plasma gas-solid catalytic reaction device also includes a plasma power supply for supplying power to the electrodes and a heating power supply for supplying power to the heating structure. A vacuum connection pipe and an outlet connected to the reaction chamber are provided on the reactor. The vacuum connection pipe is connected to a vacuum pump, a vacuum gauge, and a pressure gauge. A back pressure valve is provided at the outlet to regulate the pressure within the reaction chamber.

2. The micro-plasma gas-solid catalytic reaction device according to claim 1, characterized in that: The electrode includes a first electrode and a second electrode, which are disposed on the same side of the insulating substrate.

3. The micro-plasma gas-solid catalytic reaction device according to claim 1, characterized in that: The electrode includes a first electrode and a second electrode, which are respectively disposed on two different sides of the insulating substrate.

4. The micro-plasma gas-solid catalytic reaction device according to claim 2 or 3, characterized in that: The minimum distance between the first electrode and the second electrode is 1 μm–10 mm.

5. The micro-plasma gas-solid catalytic reaction device according to claim 1, characterized in that: The electrode includes a first electrode, a second electrode, and a third electrode. The first electrode and the second electrode are disposed on the same side of the insulating substrate, and the first electrode and the third electrode are disposed on two different sides of the insulating substrate, respectively.

6. The micro-plasma gas-solid catalytic reaction device according to claim 1, characterized in that: The heating structure includes a ceramic heating element.

7. The micro-plasma gas-solid catalytic reaction device according to claim 1, characterized in that: The insulating substrate is composed of quartz and / or silicon wafers, and the heating structure includes an electric heating element disposed on the insulating substrate.

8. The micro-plasma gas-solid catalytic reaction device according to claim 1, characterized in that: A window is provided above the micro-plasma electrode structure on the reactor. A window plate is sealed at the window. A spectrometer is provided above the window. The spectrometer can collect ultraviolet-visible or infrared spectra in the micro-plasma gas-solid catalytic reaction through the window plate.

9. The micro-plasma gas-solid catalytic reaction device according to claim 8, characterized in that: The window is made of one of the following materials: quartz, sapphire, potassium bromide, zinc selenide, calcium fluoride, or sodium chloride.

10. The micro-plasma gas-solid catalytic reaction device according to claim 1, characterized in that: The reactor's outlet is connected to a mass spectrometer or a gas chromatograph.

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