Multi-channel rotating sliding arc plasma device for methane conversion

Abstract

The invention provides a multi-channel rotating sliding arc plasma device for methane conversion, a high-voltage electrode comprises a connecting column, one end of the connecting column is provided with a plurality of sharp corners in different directions, the other end of the connecting column is connected with a motor, a gas inlet comprises a main gas inlet, the main gas inlet is divided into a plurality of branch gas inlets through gas inlet channels, and the branch gas inlets are communicated with the gas inlet channels. The number of the branch air inlets is consistent with that of the sharp corners in the high-voltage electrode, the branch air inlets enter the reaction cavity, and each branch air inlet corresponds to one sharp corner. According to the methane partial oxidation reaction device, efficient conversion of methane can be achieved, and liquid products generated in the methane partial oxidation reaction process can be collected. According to the invention, a plurality of sliding arcs can be generated in the plasma reactor cavity, so that the methane treatment efficiency is improved; the electric arc can extend to a farther position by optimizing the electrode structure, so that the discharge area of the gliding arc plasma is increased, the contact time of methane molecules and the electric arc is prolonged, and finally the conversion effect of methane is improved.

Description

Technical Field

[0001] The invention relates to a plasma device, in particular to a multi-channel rotating sliding arc plasma device for methane conversion. Background Art

[0002] As an important energy substance and organic compound, the rational use of methane to produce high-value chemical products such as methanol or clean energy such as hydrogen and synthesis gas can not only significantly improve the economic benefits of methane but also reduce dependence on traditional fossil energy.

[0003] Gliding arc discharge plasma possesses the characteristics of both high-temperature and low-temperature plasmas, with high electron density and high chemical activity. It can quickly break the stable C-H bonds in methane molecules and accelerate the methane activation reaction. However, the discharge region of a conventional sliding arc is a two-dimensional plane, resulting in a small contact area between the arc and the reactant molecules. This shortens the residence time of the reactant molecules in the reactor, leading to low reactant conversion rates and limiting the industrial application of conventional sliding arc plasma.

[0004] By optimizing the electrode structure and the coordination of the electric field and the flow field, a three-dimensional rotating sliding arc can be generated, which not only increases the contact time between the reactants and the arc, but also makes the active particles generated by the plasma evenly distributed in the reactor through the rotating airflow, thereby enhancing the interaction between the reactants and the plasma. Although the effective area of ​​the arc is increased by rotating the gas, the complex turbulent flow caused by the swirl has a significant impact on the discharge characteristics of the arc, which correspondingly increases the difficulty of regulating the arc performance. In addition, the existing rotating sliding arc device only has a single arc during discharge, so the processing efficiency needs to be improved. For the exothermic reaction of partial oxidation of methane to produce oxygen-containing liquid products, the existing rotating sliding arc devices have the problem of being unable to collect the liquid products due to the excessively high temperature in the reaction area. Summary of the Invention

[0005] 1. Technical problems to be solved: How to increase the probability of contact between methane molecules and electric arc, thereby improving its conversion effect.

[0006] 2. Technical solution: In order to solve the above problems, the present invention provides a multi-channel rotating sliding arc plasma device for methane conversion, including a cylindrical reaction chamber, a high-voltage electrode is arranged in the reaction chamber, and a low-voltage electrode is a stainless steel cylinder arranged between the reaction chamber and the high-voltage electrode and coaxial with the reaction chamber and connected to the ground. The high-voltage electrode includes a connecting column, which is coaxial with the reaction chamber, one end of which is provided with multiple sharp corners in different directions, and the other end passes through the top cover of the reaction chamber and is connected to a motor. The motor drives the high-voltage electrode to rotate in the reaction chamber. The air inlet includes a main air inlet, and the main air inlet is divided into multiple branch air inlets through an air inlet channel. The number of the branch air inlets is consistent with the number of sharp corners in the high-voltage electrode. The branch air inlet enters the reaction chamber from the first air inlet reserved port at the top of the reaction chamber, and each of the branch air inlets corresponds to a sharp corner.

[0007] The high-voltage electrode further includes an edge, and the sharp corner is connected downwardly to the connecting column through the edge.

[0008] It also includes a liquid product collector with the same diameter as the reaction chamber. The top of the liquid product collector and the bottom of the reaction chamber are connected by threads, and the gas outlet is set on the liquid product collector.

[0009] A ceramic membrane is placed between the reaction chamber and the liquid product collector.

[0010] The low-voltage electrode includes a quartz cover, which is provided with a second air inlet reserved for the same number, size, and position as the first air inlet reserved. The quartz cover is also provided with a high-voltage electrode reserved hole. The low-voltage electrode is connected to the ground via a grounding bolt. The motor holder is placed coaxially with the reaction chamber. There is a reserved space in the center of the motor holder that is the same size as the motor used. A motor fixing cover is provided on the motor. The motor fixing cover is provided with a motor wire reserved hole for leading out the wire to connect to the power supply.

[0011] The reaction cavity is provided with a water inlet and a water outlet.

[0012] A bolt fixing hole is provided below the water inlet of the reaction chamber and near the top of the water outlet. Bolts are inserted into the bolt fixing holes and contact the low-voltage electrodes, so that the reaction chamber and the low-voltage electrodes will not be displaced.

[0013] A baffle is provided above the bolt fixing hole and below the water inlet.

[0014] The high voltage electrode has four sharp corners.

[0015] 3.Beneficial effects: This invention proposes a multi-channel rotating gliding arc plasma device for methane conversion, which not only achieves efficient methane conversion but also collects liquid products produced during the methane partial oxidation reaction. By using a motor-driven irregular conical electrode structure coupled with a distributed flow field, multiple gliding arcs are generated within the plasma reactor chamber, thereby improving methane processing efficiency. Furthermore, the three-dimensional electrode structure provides a longer arc extension, which in turn increases the discharge area of ​​the gliding arc plasma, thereby increasing the contact time between methane molecules and the arc and ultimately improving methane conversion. An external water cooling device creates a temperature gradient outside the reactor, facilitating the separation and collection of liquid products produced during the reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the device structure.

[0017] Figure 2 This is the intake system structure diagram.

[0018] Figure 3 It is a schematic diagram of low voltage electrode.

[0019] Figure 4 is a schematic diagram of the reaction chamber.

[0020] Figure 5 This is the main view of the high-voltage electrode.

[0021] Figure 6 It is a top view of the high voltage electrode.

[0022] Figure 7 is a schematic diagram of the liquid product collector.

[0023] Explanation of the reference numerals: 1. Air inlet; 101. Main air inlet; 102. Branch air inlet; 2. Motor; 3. Air inlet channel; 4. Reaction chamber; 401. Motor fixing cover; 402. Motor wire reserved hole; 403. First air inlet reserved hole; 404. Motor holder; 405. Bolt fixing hole; 5. Water inlet; 6. High-voltage electrode; 601. Connecting column; 602. Sharp corner; 603. Edge; 7. Water outlet; 8. Low-voltage electrode; 801. High-voltage electrode reserved hole; 802. Quartz cover; 803. Second air inlet reserved hole; 804. Stainless steel cylinder; 9. Grounding bolt; 10. Filter membrane; 11. Thread; 12. Air outlet; 13. Liquid product collector; 1302. Collection area. DETAILED DESCRIPTION

[0024] The present invention will be described in detail below with reference to the accompanying drawings, taking the high-voltage electrode 6 having four sharp corners as an example.

[0025] The present invention generates four electric arcs simultaneously, which improves the reaction efficiency while consuming about one-third of the energy of the traditional rotary sliding arc, significantly reducing the energy required for methane conversion and improving the overall energy efficiency.

[0026] like Figure 1 As shown, a multi-channel rotating sliding arc plasma device for methane conversion includes a cylindrical reaction chamber 4, a high-voltage electrode 6 is arranged in the reaction chamber 4, and a low-voltage electrode 8 is a stainless steel cylinder 804 arranged between the reaction chamber 4 and the high-voltage electrode 6 and is coaxial with the reaction chamber 4 and connected to the ground.

[0027] In one embodiment, Figure 5 As shown, the high-voltage electrode 4 includes a connecting column 601, which is coaxial with the reaction chamber 4, one end of which is provided with multiple sharp corners 602 in different directions, and the other end passes through the top cover of the reaction chamber 4 and is connected to the motor 2, and the motor 2 drives the high-voltage electrode 4 to rotate in the reaction chamber 4.

[0028] The present invention proposes a multi-channel rotating sliding arc plasma device for methane oxidation reaction. It uses a high-speed rotating motor to drive the rotation of the electrode. Combined with a distributed flow field, it can form multiple spirally rotating arcs in the reaction chamber. This not only controls the rotation speed of the arc but also increases the number of discharge channels, which is beneficial to the contact and mutual reaction between plasma and reactants.

[0029] In one embodiment, Figure 6 The high-voltage electrode 6 further includes an edge 603 , and the sharp corner 602 is downwardly connected to the connecting post 601 via the edge 603 .

[0030] An arc will be generated between the high-voltage electrode 6 and the grounded low-voltage electrode 8 between the electrode tip and the inner wall of the external medium. Due to high-speed rotation, the generated arc will be stretched tangentially and affected by the exhaust gas from the upper branch air inlet 102. The arc will be blown longitudinally and slide downward along the edge 603 of the electrode until it reaches the bottom of the electrode.

[0031] The high-voltage electrode 6 has a length and width of 60 to 90 mm. The electrode connecting post is approximately 70 to 100 mm long and has a diameter of 20 to 30 mm. The angle of the sharp corner 602 is between 25° and 40°, and the four corners of the high-voltage electrode are equal. The total height of the high-voltage electrode is approximately 110 to 150 mm, and the length of the edge 603 is 75 to 110 mm, ensuring the sliding effect of the arc.

[0032] The present invention designs the high-voltage electrode into a three-dimensional cone. On the one hand, it enables multiple arcs to be generated in the reaction chamber at one time, thereby increasing the contact time between the arcs and the reactants. On the other hand, the generated arcs will slide downward along the edges of the high-voltage electrode under the impetus of the motor and airflow, forming a three-dimensional reaction area, thereby increasing the discharge area of ​​the plasma and thereby facilitating the improvement of the overall reaction performance.

[0033] In one embodiment, Figure 2 As shown, the air inlet 1 includes a main air inlet 101, and the main air inlet 101 is divided into multiple branch air inlets 102 through the air inlet channel 3. The number of the branch air inlets 102 is consistent with the number of sharp corners 602 in the high-voltage electrode. The branch air inlets 102 enter the reaction chamber 4 from the first air inlet reserved port 403 at the top of the reaction chamber 4, and each of the branch air inlets 102 corresponds to a sharp corner 602.

[0034] The outer diameter of the main air inlet 101 is 6~10mm and the thickness is 1~2mm, the outer diameter of the branch air inlet 3 is 6~10mm and the thickness is 1~2mm, and the outer diameter of the air outlet 12 is 6~10mm and the thickness is 1~2mm.

[0035] After entering the main gas inlet 1, the gas is divided into multiple gas paths. Each gas path enters the reaction chamber 4 through a branch gas inlet 3, and an arc is formed at the minimum distance between the high-voltage electrode 6 and the low-voltage electrode 8. The formed arc rotates in the reaction chamber under the joint action of the motor 2 and the airflow, slides and extends toward the outlet, and finally leaves the reaction chamber through the outlet 12.

[0036] In one embodiment, Figure 7 As shown, it also includes a liquid product collector 13, which is a quartz cylindrical barrel with an inner diameter of 90~120mm and a thickness of 2~6mm. The liquid product collector 13 is connected to the reaction chamber 4 through a thread 11, and the collection area 1302 in the liquid product collector 13 is used to collect liquid products.

[0037] In one embodiment, a ceramic membrane 10 is placed between the reaction chamber 4 and the liquid product collector 13, so that the reaction product is first filtered through the ceramic membrane after passing through the reaction chamber, and then enters the liquid product collector 13, ensuring that some impurities generated in the reaction will be adsorbed by the ceramic membrane 10 to ensure that the liquid product is not contaminated.

[0038] In one embodiment, the gas outlet 1301 is provided on the liquid product collector 13 .

[0039] In one embodiment, Figure 3As shown, the low-voltage electrode 8 also includes a quartz cover 802, a stainless steel cylinder 804 with an outer diameter of 80~110 mm and a thickness of 2~5 mm, a diameter of 80~110 mm, and a high-voltage electrode reserved hole 801 of 20~30 mm. A second air intake reserved hole 803 with the same number, size, and position as the first air intake reserved hole 403 is also provided. The low-voltage electrode 8 is connected to the ground through a grounding bolt 9.

[0040] In one embodiment, Figure 4 As shown, the reaction chamber 4 is made of glass with an outer diameter of 90-120 mm and a thickness of 3-6 mm. It has four first air inlet openings 403 with a diameter of 6-10 mm at the top, and bolt fixing holes 405 with a diameter of 2-4 mm are reserved 10-15 mm from the bottom. The motor holder 404 is coaxially placed with the reaction chamber body 4 and has an outer diameter of 20-35 mm. A reserved space in the center, the same size as the motor, is provided to facilitate securing the motor 2.

[0041] In one embodiment, the reaction chamber 4 is provided with a water inlet 5 and a water outlet 7. The water inlet 5 and the water outlet 7 are the same, with a diameter of 6-10 mm and a thickness of 1-2 mm.

[0042] Methane oxidation is an exothermic reaction, releasing a large amount of heat. Combined with the heat generated by the rotating gliding arc plasma, this creates a high-temperature zone that vaporizes the liquid products produced during the reaction, making them impossible to collect. The present invention utilizes an external cooling device to regulate the temperature of the reactor's ground electrodes, creating a temperature gradient across the reactor, effectively collecting the liquid products formed during the reaction.

[0043] In one embodiment, the motor fixing cover 401 is made of quartz with an outer diameter of 20-35 mm. A hole 402 with a diameter of 1-2 mm is punched into the cover for the motor wires to be connected to the power supply. After the two are coaxially positioned, a bolt is inserted into the fixing hole 405 to prevent displacement between the high-voltage electrode 6 and the low-voltage electrode 8.

[0044] In one embodiment, a baffle with a thickness of 1 to 2 mm is placed in the glass wall of the reaction chamber 4 to 5 mm above the fixing hole 405. The baffle is below the water inlet 5 and above 405, which is equivalent to water only above the baffle, preventing water from leaking out of 405 and preventing water seepage.

[0045] The overall workflow of the present invention is as follows: methane gas enters from the main air inlet 1 and is evenly divided into four gas paths, each entering the four branch air inlets 3 below. A motor 2 is connected to a high-voltage electrode 6 via a connecting column. When powered, the motor 2 drives the high-voltage electrode 6 to rotate at high speed. A low-voltage electrode 8 is connected to the ground via a grounding bolt 9. An arc is generated between the electrode tips and the inner wall of the external dielectric. Due to the high-speed rotation, the generated arc is stretched tangentially. Influenced by the gas exiting the branch air inlet above, the arc is blown longitudinally, sliding downward along the electrode edges to the bottom of the electrode. Methane undergoes an oxidation reaction in the arc, and the reacted gas flows downward. After being treated by a catalyst placed in the reaction chamber, it is filtered by a ceramic membrane 10 and reaches the gas outlet 12, exiting the reaction chamber and being collected by a gas collection bag. Water enters from the water inlet 5 via a circulating water pump, flows upward along the water flow channel 4, causing the discharge area to continuously cool, and then flows downward to the water outlet 7. The temperature gradient formed within the reaction chamber is conducive to the formation of liquid products, which, along with a small amount of impurities produced by the reaction, flow under the influence of gravity toward the liquid product collector 13. The liquid products preferentially permeate the ceramic membrane 10 and then flow into the liquid product collector 13, while the impurities are adsorbed by the ceramic membrane 10 and cannot pass through, thereby improving the purity of the collected product and facilitating subsequent analysis.

Claims

1. A multi-channel rotating sliding arc plasma device for methane conversion, comprising a cylindrical reaction chamber (4), a high-voltage electrode (6) disposed in the reaction chamber (4), and a low-voltage electrode (8) which is a stainless steel cylinder (804) disposed between the reaction chamber (4) and the high-voltage electrode (6) and coaxial with the reaction chamber (4) and connected to the ground, characterized in that: The high-voltage electrode (4) includes a connecting column (601), which is coaxial with the reaction chamber (4), one end of which is provided with multiple sharp corners (602) in different directions, and the other end passes through the top cover of the reaction chamber (4) and is connected to the motor (2), and the motor (2) drives the high-voltage electrode (4) to rotate in the reaction chamber (4). The air inlet (1) includes a main air inlet (101), and the main air inlet (101) is divided into multiple branch air inlets (102) through the air inlet channel (3). The number of the branch air inlets (102) is consistent with the number of sharp corners (602) in the high-voltage electrode (6). The branch air inlets (102) enter the reaction chamber (4) from the first air inlet reserved port (403) at the top of the reaction chamber (4), and each of the branch air inlets (102) corresponds to a sharp corner (602).

2. The multi-channel rotating sliding arc plasma device for methane conversion according to claim 1, characterized in that: The high-voltage electrode (6) further comprises an edge (603), and the sharp corner (602) is connected downwardly to the connecting column (601) via the edge (603).

3. The multi-channel rotating sliding arc plasma device for methane conversion according to claim 1, characterized in that: It also includes a liquid product collector (13) having the same diameter as the reaction chamber (4), the top of the liquid product collector (13) and the bottom of the reaction chamber (4) being connected via a thread (11), and an air outlet (1301) being provided on the liquid product collector (13).

4. The multi-channel rotating sliding arc plasma device for methane conversion according to claim 2, characterized in that: A ceramic membrane (10) is placed between the reaction chamber (4) and the liquid product collector (13).

5. The multi-channel rotating sliding arc plasma device for methane conversion according to claim 1, characterized in that: The low-voltage electrode (8) includes a quartz cover (802), the quartz cover (802) is provided with a second air inlet reserved opening (803) having the same number, size, and position as the first air inlet reserved opening (403), and the quartz cover (802) is also provided with a high-voltage electrode reserved hole (801). The low-voltage electrode (8) is connected to the ground via a grounding bolt (9).

6. The multi-channel rotating gliding arc plasma device for methane conversion according to claim 1, characterized in that: The motor holder (404) is coaxially placed with the reaction chamber (4), and a reserved space of the same size as the motor (2) is provided at the center of the motor holder (404). A motor fixing cover (401) is provided on the motor (2), and the motor fixing cover (401) is provided with a motor wire reserved hole (402) for leading out a wire to connect to a power supply.

7. The multi-channel rotating gliding arc plasma device for methane conversion according to claim 1, characterized in that: The reaction chamber (4) is provided with a water inlet (5) and a water outlet (7).

8. The multi-channel rotating sliding arc plasma device for methane conversion according to claim 7, characterized in that: A bolt fixing hole (405) is provided below the water inlet (5) of the reaction chamber (4) and above the water outlet (7). A bolt is inserted into the bolt fixing hole (2) and contacts the low-voltage electrode (8), so that the reaction chamber (4) and the low-voltage electrode (8) do not move.

9. The multi-channel rotating sliding arc plasma device for methane conversion according to claim 8, characterized in that: A baffle is provided above the bolt fixing hole (405) and below the water inlet (5).

10. The multi-channel rotating sliding arc plasma device for methane conversion according to any one of claims 1 to 9, characterized in that: The high-voltage electrode (6) has four sharp corners (602).

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