Plasma apparatus and method for decomposing gases

Abstract

The present disclosure relates to a plasma device and method. The plasma device includes an inner electrode and an outer electrode. The inner electrode includes a wall defining a first cavity, the opening of the first cavity being configured to receive a first gas. The outer electrode surrounds the inner electrode. The inner electrode has a through-hole extending through the wall of the inner electrode, and the first cavity is in fluid communication with a plasma generation region between the inner electrode and the outer electrode via the through-hole. The inner electrode is rotatable about a first rotation axis, the first rotation axis extending through the first cavity. In particular, some embodiments of the present disclosure relate to a plasma device and method for decomposing gases.

Description

Technical Field

[0003] ,

[0001] (Related Application) This application claims priority to U.S. Provisional Patent Application No. 63 / 391,421, filed on July 22, 2022, entitled "Method for simultaneous production of carbon and hydrogen by plasma cracking of hydrocarbon gas", the entire content of which is incorporated herein by reference.

[0002] (Technical Field) The present disclosure relates to plasma devices and methods. In particular, some embodiments of the present disclosure relate to plasma devices and methods for decomposing gases.

Background Art

[0003] Plasma is considered the fourth state of matter, beyond solid, liquid, and gas. It is defined as a state of matter in which electrons, ions, and electrically neutral particles coexist in the same space. Plasma technology is widely used in many industries. Interacting with matter using high-energy particles within a plasma can enhance reactions. Plasmas are classified into vacuum plasma, atmospheric pressure plasma, and high-pressure plasma based on their operating environment and pressure, each with its own application area. For example, vacuum plasma is commonly used for coating. The material to be coated is targeted and placed on the cathode. An additional gas, such as argon, is used as the working gas (or carrier gas), and a voltage is applied to generate plasma from the working gas. By impacting the plasma onto the target, the material is sputtered onto the substrate to be coated, resulting in a coating on the substrate. Atmospheric pressure plasma is commonly used for applications such as surface modification and cleaning. Working gases used in atmospheric pressure plasma processing may include nitrogen, oxygen, argon, air, or combinations of the aforementioned gases. The working gas is used to generate plasma under atmospheric pressure. The generated plasma is typically applied to the surface of an object for surface treatment applications.

[0004] When using plasma to decompose hydrocarbons into hydrogen and carbon, the carbon generated during the decomposition process can coat the electrodes, stopping both plasma generation and the plasma decomposition of hydrocarbons. To avoid this problem, nitrogen, oxygen, argon, air, or a combination of the aforementioned gases are used as the primary working gas for plasma generation. As a result, in some cases, only small amounts (e.g., less than 10%) of hydrocarbon gas enter the device, leading to relatively low dissociation efficiency and product yield. [Overview of the project]

[0005] A plasma apparatus is provided according to this disclosure. The plasma apparatus comprises an inner electrode and an outer electrode. The inner electrode has a wall defining a first cavity, the opening of which is configured to receive a first gas. The outer electrode surrounds the inner electrode. The inner electrode has a through hole extending through the wall of the inner electrode, and the first cavity is in fluid communication with a plasma generation region between the inner electrode and the outer electrode through the through hole. The inner electrode is rotatable about a first axis of rotation, the first axis of rotation passing through the first cavity.

[0006] In one embodiment, both the inner electrode and the outer electrode are substantially tubular.

[0007] In one embodiment, the outer electrode is positioned coaxially with the inner electrode.

[0008] In one embodiment, the plasma apparatus further includes a rotating member mechanically coupled to the inner electrode so that the inner electrode can rotate about a first axis of rotation.

[0009] In one embodiment, the rotating member includes a bearing or a rotor.

[0010] In one embodiment, the plasma apparatus further includes a motor coupled to an inner electrode and configured to provide a rotational driving force for rotating the inner electrode about a first axis of rotation.

[0011] In one embodiment, the through-hole is configured to acquire a rotational driving force from a first gas flow from a first cavity to a plasma generation region through the through-hole, and the rotational driving force rotates the inner electrode about a first axis of rotation.

[0012] In one embodiment, the first angle between the extensional direction of the through-hole and the radial direction of the through-hole on the cross-sectional plane of the inner electrode is between approximately 5 degrees and approximately 85 degrees, and the cross-sectional plane is perpendicular to the longitudinal axis of the inner electrode.

[0013] In one embodiment, the second angle between the extension direction of the through hole and the axial direction is between approximately 5 degrees and approximately 85 degrees, and the axial direction coincides with the longitudinal axis of the inner electrode and extends from a point in the first cavity toward the opening of the first cavity.

[0014] In one embodiment, the plasma apparatus further includes a gas inlet configured to allow the flow of a first gas into a first cavity.

[0015] In one embodiment, the plasma apparatus further comprises a gas vessel coupled to a gas inlet, the gas vessel containing a first gas.

[0016] In one embodiment, the plasma apparatus further includes an insulating layer arranged in an annular manner between the outer electrode and the inner electrode.

[0017] In one embodiment, the plasma apparatus further includes a power supply electrically connected to both the inner electrode and the outer electrode, the power supply configured to provide a voltage between the inner electrode and the outer electrode.

[0018] In one embodiment, the plasma apparatus further includes a scraping unit configured to move in contact with the outer surface of the inner electrode.

[0019] In one embodiment, the scraping unit surrounds the outer surface of the inner electrode and is configured to move in a first direction along the longitudinal axis of the inner electrode and in a second direction opposite to the first direction.

[0020] In one embodiment, the scraping unit comprises a first blade, a second blade, and a connector connecting the first blade and the second blade. The first blade is configured to move in contact with the outer surface of the inner electrode, and the second blade is configured to move in contact with the inner surface of the outer electrode.

[0021] In one embodiment, the plasma device further comprises an outlet configured to output a second gas and a solid product generated from the first gas.

[0022] In one embodiment, the plasma device further comprises a separation device connected to the outlet, the separation device being configured to separate the solid product from the second gas.

[0023] In one embodiment, the separation device comprises a dust collector and a filter screen connected to the dust collector.

[0024] In one embodiment, the plasma device further comprises a bottom cover connected to the outer electrode at an end of the outer electrode, the outlet being disposed in the bottom cover.

[0025] In one embodiment, the outer electrode comprises a gas pipe embedded in a wall of the outer electrode, the gas pipe being configured to introduce the first gas into the plasma generation region.

[0026] In one embodiment, the first gas comprises a hydrocarbon gas.

[0027] According to the present disclosure, a method is provided. The method comprises introducing a first gas into a first cavity defined by a wall of an inner electrode through an opening of the first cavity. The method comprises flowing the first gas from the first cavity through a through hole penetrating the wall of the inner electrode into a plasma generation region between the inner electrode and an outer electrode surrounding the inner electrode. The method comprises generating plasma in the plasma generation region by applying a voltage between the inner electrode and the outer electrode. The method comprises decomposing the first gas using the plasma. The method comprises rotating the inner electrode about a first rotation axis, the first rotation axis penetrating the first cavity.

[0028] In one embodiment, generating the plasma comprises generating the plasma from a portion of the first gas.

[0029] In one embodiment, the first gas comprises a hydrocarbon gas.

[0030] In one embodiment, the method further comprises discharging the product generated from the decomposition of the first gas from the outlet.

[0031] In one embodiment, the product comprises a second gas and a solid product.

[0032] In one embodiment, the method further comprises separating the solid product from the second gas by a separation device.

[0033] In one embodiment, the method further comprises introducing the second gas into a generator.

[0034] In one embodiment, rotating the inner electrode comprises obtaining a rotational driving force from the flow of the first gas from the first cavity through the through-hole to the plasma generation region.

[0035] In one embodiment, rotating the inner electrode comprises providing a rotational driving force from a motor coupled to the inner electrode.

[0036] In one embodiment, the method further comprises removing the solid product adhering to the inner electrode by a scraping unit.

[0037] In one embodiment, the method further comprises cooling the inner electrode by the flow of the first gas from the first cavity through the through-hole to the plasma generation region.

[0038] In one embodiment, introducing the first gas comprises introducing the first gas from a gas container into the first cavity.

[0039] In one embodiment, the method further comprises heating the first gas before it is introduced into the first cavity.

[0040] In one embodiment, the method further comprises introducing a first gas into the plasma generation region through a gas pipe embedded in the wall of the outer electrode. [Brief explanation of the drawing]

[0041] [Figure 1A] This is a schematic diagram of a plasma apparatus according to one embodiment of the present disclosure. [Figure 1B] This is a schematic diagram of a plasma apparatus according to one embodiment of the present disclosure. [Figure 2] This is a schematic diagram of a plasma apparatus according to one embodiment of the present disclosure. [Figure 3A] This is a schematic diagram of an inner electrode according to one embodiment of the present disclosure. [Figure 3B] This is a schematic diagram of an inner electrode according to one embodiment of the present disclosure. [Figure 4] This is a schematic diagram of an inner electrode according to one embodiment of the present disclosure. [Figure 5A] This is a schematic diagram of a scraping unit according to one embodiment of the present disclosure. [Figure 5B] This is a schematic diagram of a scraping unit according to one embodiment of the present disclosure. [Figure 6] This is a schematic cross-sectional view of a scraping unit according to one embodiment of the present disclosure. [Figure 7] This is a schematic diagram of a plasma apparatus according to one embodiment of the present disclosure. [Figure 8] This is a schematic diagram of a plasma apparatus according to one embodiment of the present disclosure. [Figure 9] This is a flowchart illustrating a method according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0042] The terms used in the following description are intended to be interpreted in the broadest and most reasonable manner, even when used in conjunction with a detailed description of a particular embodiment of the technology. Certain terms may be emphasized below, but any terms intended to be interpreted restrictively are specifically defined in this detailed description section. Components and results of plasma apparatuses according to this disclosure can be illustrated in the following drawings and embodiments. However, the sizes and shapes illustrated in the drawings of plasma apparatuses do not limit the features of this disclosure.

[0043] As used herein, the term “above” can mean directly above or indirectly above through an intervening element or layer. For convenience of explanation, spatially relative terms such as “directly below,” “downward,” “below,” “up,” and “above” may be used to describe the relationship between one element or feature and another, as illustrated in the drawings. Spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, if the device in the drawing is inverted, an element described as being “below” or “directly below” another element or feature will become “above” the other element or feature. Thus, the illustrative term “downward” can encompass both upward and downward orientations. The device may be oriented differently (by being rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein may be interpreted accordingly.

[0044] Figures 1A and 1B are schematic diagrams of a plasma apparatus according to one embodiment of the present disclosure. Figure 1B is a schematic cross-sectional view of the plasma apparatus of Figure 1A along the line A-A'. As shown in Figures 1A and 1B, the plasma apparatus 100 comprises an inner electrode 104 and an outer electrode 105. The inner electrode 104 has a wall 104a defining a first cavity 119, and the opening 104b of the first cavity 119 is configured to receive a first gas 109. The outer electrode 105 surrounds the inner electrode 104 and defines a plasma generation region 106 between the inner electrode 104 and the outer electrode 105. The inner electrode 104 may have a through hole 118 penetrating the wall 104a of the inner electrode 104, thereby the first cavity 119 is in fluid communication with the plasma generation region 106 between the inner electrode 104 and the outer electrode 105 through the through hole 118. Therefore, the first gas 109 can flow through the opening 104b into the first cavity 119, and then into the plasma generation region 106 through the through-holes 118. In some embodiments, the inner electrode 104 may have a plurality of through-holes 118 penetrating the wall 104a of the inner electrode 104.

[0045] The inner electrode 104 may be made of stainless steel, copper, graphite, molybdenum, aluminum, any suitable conductive material, or a combination thereof. The outer electrode 105 may be made of stainless steel, aluminum, any suitable conductive material, or a combination thereof. In the embodiments illustrated in Figures 1A and 1B, the inner electrode 104 is substantially tubular, and the opening 104b of the first cavity 119 is located at the first end 104e of the inner electrode 104. The second end 104f of the inner electrode 104, opposite the first end 104e, may be closed. However, the disclosure is not limited thereto. The outer electrode 105 may also be substantially tubular. In some embodiments, the outer electrode 105 is positioned coaxially with the inner electrode 104. In some embodiments, the gap between the inner electrode 104 and the outer electrode 105 is constant. Although the inner electrode 104 and the outer electrode 105 are exemplified as having a constant radius along their longitudinal axis, in some embodiments the radii of the inner electrode 104 and the outer electrode 105 may vary along their longitudinal axis. For example, the inner electrode 104 and / or the outer electrode 105 may be hollow conical in shape.

[0046] As shown in Figures 1A and 1B, the outer electrode 105 surrounds the second end 104f of the inner electrode 104. In some embodiments, the length of the inner electrode 104 is shorter than the length of the outer electrode 105. In some embodiments, the inner electrode 104 may have a length of about 20 mm to about 300 mm. In some embodiments, the outer electrode 105 may have a length of about 30 mm to about 500 mm. The inner electrode 104 may have an inner diameter 104i of about 5 mm to about 50 mm and an outer diameter 104o of about 20 mm to about 70 mm. The wall 104a of the inner electrode 104 may have a thickness of about 7.5 mm to about 10 mm. The outer electrode 105 may have an inner diameter 105i of about 25 mm to about 100 mm and an outer diameter 105o of about 30 mm to about 110 mm. The wall 105a of the outer electrode 105 may have a thickness of approximately 2.5 mm to approximately 5 mm. These values ​​are merely examples and are not intended to be limiting.

[0047] The inner electrode 104 is rotatable about a first axis of rotation 104c, which passes through the first cavity 119 of the inner electrode 104. In some embodiments, the first axis of rotation 104c may coincide with the longitudinal axis of the inner electrode 104 (for example, the longitudinal axis 104n as illustrated in Figures 3A, 3B, and 4). In other words, the inner electrode 104 may be rotatable about its longitudinal axis. In this specification, the longitudinal axis may refer, for example, an axis that runs along the length of the inner electrode 104 from the first end 104e to the second end 104f, passing through the center of the centroid of the inner electrode 104. Specifically, the plasma apparatus 100 is configured to allow the inner electrode 104 to be rotationally driven, particularly when the plasma apparatus 100 is in operation. In some embodiments, the plasma apparatus further includes a device such as a motor for providing a rotational driving force to rotate the inner electrode (as will be described in more detail below with respect to Figure 7). In some embodiments, the inner electrode may be configured to be driven to rotate by a first gas flow passing through the wall of the inner electrode (as will be described in more detail below with respect to Figures 3A and 3B). This can mitigate the problem of solid product accumulation on the outer surface of the inner electrode 104 during plasma decomposition, allowing the plasma apparatus 100 to continue operating for a reasonable period without introducing additional working gas. Thus, dissociation efficiency and product yield can be improved, and undesirable byproducts formed by reaction with additional working gas can be avoided. Furthermore, the frequency of maintenance and downtime of the plasma apparatus due to solid product accumulation can also be reduced.

[0048] As shown in Figures 1A and 1B, the plasma apparatus 100 further includes a gas inlet 102. The gas inlet 102 may be coupled to the inner electrode 104 at the opening 104b of the first cavity 119 and may be configured to allow the first gas 109 to flow into the first cavity 119.

[0049] In some embodiments, the plasma apparatus 100 further comprises a gas container 108. The gas container 108 may contain a first gas 109 and may be coupled to a gas inlet 102 that supplies the first gas 109 to a first cavity 119 for plasma decomposition. In some embodiments, the gas container 108 may be a pressurized gas container. In one embodiment, the plasma apparatus 100 may further comprise a gas intake valve 101 configured to control the flow rate of the first gas 109 to the first cavity 119. In some embodiments, the first gas 109 comprises hydrocarbon gases such as alkanes, alkenes, cycloalkanes, and aromatic hydrocarbons, including, but not limited to, methane, ethane, propane, butane, ethylene, natural gas, compressed natural gas (CNG), petroleum gas, and combinations thereof. In some embodiments, the first gas 109 may comprise gases vaporized from hydrocarbon liquids such as alkanes, alkenes, cycloalkanes, and aromatic hydrocarbons, including, but not limited to, hexane, diesel, gasoline, kerosene, and combinations thereof. Hydrocarbon liquids can be vaporized by heating in a vaporizer to become a gaseous state. In some embodiments, the first gas 109 is a pure or substantially pure hydrocarbon, and it may be necessary to filter out impurities in order to provide a substantially pure hydrocarbon. In some embodiments, the first gas 109 may be filtered through a filter before flowing into the first cavity 119. In some embodiments, the first gas 109 may be preheated before flowing into the first cavity 119, thereby increasing the dissociation efficiency of the first gas 109. For example, the first gas 109 may flow through a waste heat recycling system and be heated by waste heat recycling from a power plant.

[0050] In the embodiment illustrated in Figure 1A, the plasma apparatus 100 further includes a power supply 107. The power supply 107 is electrically connected to both the inner electrode 104 and the outer electrode 105 and is configured to provide a voltage between the inner electrode 104 and the outer electrode 105 so that plasma is generated in the plasma generation region 106. In some embodiments, the plasma is generated from a portion of a first gas 109. The plasma can decompose the molecules of the first gas 109 and break the chemical bonds within them. As a result, the first gas 109 may be dissociated, and products such as a second gas 125 and solid products 124 may be generated. In situations where the first gas contains hydrocarbons, hydrocarbon molecules may be dissociated, and carbon and hydrogen may be generated.

[0051] In some embodiments, the power supply 107 comprises a direct current (DC) power supply and / or an alternating current (AC) power supply. In the embodiment illustrated in Figure 1A, the outer electrode 105 may be grounded. In some embodiments, the magnitude of the voltage and / or frequency of the power supply can be adjusted to achieve a higher conversion rate and / or higher energy efficiency.

[0052] In the embodiment illustrated in Figure 1A, the plasma apparatus 100 may further include an insulating layer 103 between the outer electrode 105 and the inner electrode 104. The insulating layer 103 may be arranged in an annular shape and may enclose a portion of the inner electrode 104 so that the inner electrode 104 is electrically insulated from the outer electrode 105. The insulating layer 103 may comprise Teflon®, ceramic, any suitable insulating material, or a combination thereof. In some embodiments, the insulating layer 103 provides an airtight seal to prevent gases (e.g., a first gas 109 and a second gas 125) from leaking through the gap between the inner electrode 104 and the outer electrode 105.

[0053] In the embodiment illustrated in Figure 1A, the plasma apparatus 100 further comprises a bottom cover 111 connected to the outer electrode 105. Specifically, as shown in Figure 1A, the insulating layer 103 is coupled to the outer electrode 105 at a first end 105e of the outer electrode 105, and the bottom cover 111 is connected to the outer electrode 105 at a second end 105f opposite to the first end 105e of the outer electrode 105. In some embodiments, the bottom cover 111 may be made of a non-conductive material such as quartz, glass, plastic, any suitable insulating material, and combinations thereof. In some embodiments, the bottom cover 111 may be made of a conductive material such as stainless steel, any suitable conductive material, and combinations thereof. The bottom cover 111 may be connected to the outer electrode 105 by a gasket, adhesive, welding, and / or other suitable method. The connection between the bottom cover 111 and the outer electrode 105 may be airtight. The hermetically sealed configuration allows the plasma apparatus to function without an additional outer casing, enhance the dissociation efficiency of the first gas, and allow the gas pressure inside the outer electrode to be set to a higher pressure (e.g., 100 bar, depending on the degree of hermetically sealed plasma apparatus) and be easier to control. By using a gasket or welding, the connection between the bottom cover 111 and the outer electrode 105 can form a stronger hermetically sealed seal. As shown in Figure 1A, the plasma apparatus 100 further includes an outlet 116. The outlet 116 is configured to discharge a second gas 125 and solid products 124 generated from the first gas 109. In the embodiment shown in Figure 1A, the outlet 116 is located in the bottom cover 111. However, the disclosure is not limited thereto.

[0054] In the embodiment illustrated in Figure 1A, the plasma apparatus 100 further comprises a separation device 117 connected to an outlet 116. The separation device 117 is configured to separate solid products 124 from a second gas 125. As shown in Figure 1A, the separation device 117 may comprise a dust collector 120 and a filter screen 121 connected to the dust collector 120. In embodiments where the first gas 109 is a hydrocarbon gas, the separation device 117 may separate solid carbon from hydrogen gas for subsequent applications. For example, the separated solid carbon can be used as an industrial raw material, and the hydrogen gas can be used for low-carbon emission power generation. In some embodiments, the dust collector 120 is configured to collect larger sized solid carbon, and the filter screen 121 is configured to block fine carbon powder that is not collected by the dust collector 120. The second gas 125 (e.g., hydrogen gas) that has passed through the separation device 117 may be discharged from a gas outlet 122. In some embodiments, the dust collector 120 and the filter screen 121 may be selected to collect solid carbon of a desired particle size for various applications.

[0055] In the embodiment illustrated in Figure 1A, the separation device 117 may be connected to the outlet 116 through a four-way tube 113. An outlet pressure gauge 115 may be connected to the four-way tube 113 to detect the output pressure of the outlet gas from the outlet 116. In some embodiments, a sampling port 114 may be connected to the outlet 116 through the four-way tube 113. The sampling port 114 can be used to monitor the composition of the outlet gas, the dissociation efficiency, etc., and to provide feedback to the plasma apparatus 100.

[0056] As shown in Figure 1A, the plasma apparatus 100 is oriented vertically. In some embodiments, oriented the plasma apparatus 100 vertically can improve the efficiency of separating solid products 124 (e.g., solid carbon) from the second gas 125 (e.g., hydrogen gas) by assisting, for example, gravity in separating the heavier solid products 124 from the lighter second gas 125. For example, as shown in Figure 1A, the plasma apparatus 100 may further include a reactant collection area 112 directly below the plasma generation area 106. The solid products 124 can descend in the reactant collection area 112 due to gravity. Other orientations of the plasma apparatus 100 (e.g., horizontal orientation) are also possible.

[0057] Figure 2 is a schematic diagram of a plasma apparatus according to one embodiment of the present disclosure. The plasma apparatus 200 in Figure 2 may be substantially similar to the plasma apparatus 100 in Figures 1A and 1B, where the same reference numerals indicate the same elements. As illustrated in Figure 2, the plasma apparatus 200 further comprises a rotating member 203. The rotating member 203 is mechanically coupled to an inner electrode 104, which is rotatable about a first rotation axis 104c. The rotating member 203 is a mechanical element that restricts the movement of the inner electrode 104 to a desired rotation. The rotating member 203 may also provide mechanical support for the inner electrode 104. In some embodiments, the rotating member 203 comprises bearings. In some embodiments, the rotating member 203 comprises a rotor. The rotor may be driven to rotate by interaction between the rotor and its respective stator. However, the present disclosure is not limited thereto.

[0058] In the embodiment illustrated in Figure 2, the rotating member 203 is fixed to the gas inlet 102, and the insulating layer 103 seals the gap between the gas inlet 102 and the outer electrode 105. However, in other embodiments, the rotating member 203 may be fixed to the insulating layer 103, to the outer electrode 105, or to the outer casing, if present. The disclosure is not limited thereto. As shown in Figure 2, the rotating member 203 may wrap around the inner electrode 104. The rotating member 203 may be positioned between the inner electrode 104 and the outer electrode 105. In some embodiments, the rotating member 203 is arranged in an annular manner. In some embodiments, the rotating member 203 may be configured to receive a rotational driving force that rotates the inner electrode 104 about a first rotation axis 104c.

[0059] As shown in Figure 2, the inner electrode 104 has a plurality of through-holes 118 that penetrate the wall 104a of the inner electrode 104. In some embodiments, the through-holes 118 of the inner electrode 104 are configured to acquire rotational driving force from the flow of a first gas 109, which rotates the inner electrode 104 about a first axis of rotation 104c. Specifically, one or more through-holes 118 may be configured to have an extensional direction (as will be described in more detail below with respect to Figures 3A and 3B), so that when the first gas 109 flows from the first cavity 119 to the plasma generation region 106 through the through-holes 118, the flow provides rotational driving force, which can rotate the inner electrode 104 about the first axis of rotation 104c. Thus, the inner electrode 104 can be rotationally driven by the flow of the first gas 109 (e.g., a hydrocarbon gas). Thus, the rotation of the inner electrode and / or the gas flow of the first gas ejected from the through-hole can mitigate the problem of solid product (e.g., carbon) accumulation on the outer surface of the inner electrode, allowing the plasma apparatus to continue operating for a reasonable period without introducing additional working gas, and reducing the downtime of the plasma apparatus. The gas flow of the first gas ejected from the through-hole can also mitigate the problem of solid product (e.g., carbon) accumulation on the inner surface of the outer electrode. The gas flow of the first gas 109 can cool the inner electrode 104 by removing heat from it, and the outer electrode 105 can be cooled in the same way. This can extend the service life of the inner electrode 104 and / or the outer electrode 105.

[0060] In some embodiments, the rotational speed of the inner electrode 104 may be between approximately 30 revolutions per minute (rpm) and approximately 180 rpm. However, the disclosure is not limited thereto. In some embodiments, the rotational speed of the inner electrode 104 may be less than 30 rpm or greater than 180 rpm. The rotational speed of the inner electrode 104 may vary depending on its size and material, the arrangement and configuration of the through-hole 118, etc. The rotational speed may be controlled by the flow rate of the first gas 109 and adjusted to achieve a higher conversion rate and / or higher energy efficiency. In some cases, such rotation may extend the operating duration of the plasma apparatus from 1 minute to approximately 7 days, and even to approximately 1 month. These values ​​are merely examples and are not intended to be limiting.

[0061] Figure 3A is a schematic diagram of an inner electrode according to one embodiment of the present disclosure. Figure 3B is a schematic cross-sectional view of the inner electrode in Figure 3A along the cross-sectional plane 104h, where the cross-sectional plane 104h is perpendicular to the longitudinal axis 104n of the inner electrode 104. The inner electrode 104 in Figures 3A and 3B may be substantially similar to the inner electrode 104 in Figures 1A, 1B, and 2, and the same reference numerals indicate the same elements. In the embodiment illustrated in Figure 3A, the inner electrode 104 has 12 through-holes 118 arranged in three rows, including four through-holes 118 evenly distributed circumferentially (as shown in Figure 3B, the angle between adjacent through-holes 118 is substantially 90 degrees). In some embodiments, the rows of through-holes 118 may include 1 to 12 through-holes 118 evenly or unevenly distributed circumferentially. The number and distribution of through-holes 118 may be modified according to actual needs. In some embodiments, the distance 118d between adjacent rows of through-holes 118 can range from about 5 mm to about 50 mm. In some embodiments, the shape of the opening of the through-hole 118 on the wall 104a can be circular. In some embodiments, the diameter of the opening of the through-hole 118 on the wall 104a can range from about 0.5 mm to about 25 mm. These values ​​are merely examples and are not intended to be limiting.

[0062] In some embodiments, the through-holes 118 may be positioned to extend the residence time of the first gas 109 remaining within the plasma generation region 106. A longer residence time can increase the dissociation efficiency of the first gas 109. For example, near the opening 104b, the distribution of through-holes 118 may be more densely packed (e.g., more through-holes may be included in a row, and / or the distance between adjacent rows may be shorter), which can increase the residence time of the first gas 109 and the resulting dissociation efficiency.

[0063] As shown in Figure 3B, the projections of the extension direction 118f and radial direction 118r of the through-hole 118 onto the cross-sectional plane 104h are at an angle. The radial direction 118r of the through-hole 118 extends from a point on the longitudinal axis 104n of the inner electrode 104 to the through-hole 118, the extension direction 118f of the through-hole 118 extends from the first cavity 119 toward the plasma generation region 106, and the cross-sectional plane 104h refers to a plane perpendicular to the longitudinal axis 104n of the inner electrode 104. Thus, when the first gas 109 flows from the first cavity 119 through the through-hole 118 into the plasma generation region 106, this flow can provide a rotational driving force that rotates the inner electrode 104 around the first rotation axis 104c, allowing the inner electrode 104 to rotate without additional drive devices.

[0064] In some embodiments, the first angle θ1 between the longitudinal direction 118f and the radial direction 118r of the through hole 118 in the cross-sectional plane 104h of the inner electrode 104 is between about 5 degrees and about 85 degrees. However, the disclosure is not limited thereto. In some embodiments, the first angle θ1 can be less than 5 degrees or greater than 85 degrees. The first angle θ1 can be adjusted to allow a desired rotational speed of the inner electrode 104. In some embodiments, the first angle θ1 is between about 45 degrees and about 90 degrees. These values ​​are merely examples and are not intended to limit the possibilities.

[0065] Figure 4 is a schematic diagram of an inner electrode according to one embodiment of the present disclosure. The inner electrode 204 in Figure 4 may be substantially similar to the inner electrode 104 in Figures 1A to 3B, where the same reference numerals indicate the same elements. As illustrated in Figure 4, the through-hole 118 may be configured to extend "upward" to extend the residence time of the first gas 109 remaining within the plasma generation region 106. Extending the residence time can increase the dissociation efficiency of the first gas 109. In some embodiments, the second angle θ2 between the extension direction 118f of the through-hole 118 and the axial direction 104x is between about 5 degrees and about 85 degrees, where the axial direction 104x coincides with the longitudinal axis 104n of the inner electrode 104 and extends from a point 104p in the first cavity 119 toward the opening 104b of the first cavity 119. In some embodiments, the second angle θ2 may be less than 5 degrees or greater than 85 degrees. The second angle θ2 can be adjusted to achieve higher dissociation efficiency. In some embodiments, the second angle θ2 is between approximately 0 degrees and approximately 45 degrees. These values ​​are merely examples and are not intended to be limiting.

[0066] Figures 5A and 5B are schematic diagrams of a scraping unit according to one embodiment of the present disclosure. The plasma apparatus 500 in Figures 5A and 5B is substantially similar to the plasma apparatus 100 in Figures 1A and 1B, and the same reference numerals indicate the same elements. In the embodiment illustrated in Figures 5A and 5B, the plasma apparatus 500 further comprises a scraping unit 123. The scraping unit 123 is also configured to move in contact with the outer surface 104d of the inner electrode 104. The scraping unit 123 may be configured to move in contact with the inner surface 105d of the outer electrode 105. In some embodiments, the scraping unit 123 surrounds the outer surface 104d of the inner electrode 104 and is configured to move in a first direction 126 along the longitudinal axis 104n of the inner electrode 104 and in a second direction 127 opposite to the first direction 126. In some embodiments, the accumulation of solid product 124 deposited on the outer surface 104d of the inner electrode 104 and / or the inner surface 105d of the outer electrode 105 can stop plasma generation by the plasma apparatus 500. A scraping unit 123 can be used to remove the solid product 124 adhering to the inner electrode 104 and / or the outer electrode 105, thereby maintaining the operation of the plasma apparatus 500 and the plasma decomposition of the first gas 109.

[0067] As illustrated in Figures 5A and 5B, the scraping unit 123 surrounding the outer surface 104d of the inner electrode 104 can move in a first direction 126 to remove a portion of the solid product 124 deposited on the outer surface 104d of the inner electrode 104 and / or the inner surface 105d of the outer electrode 105. The scraping unit 123 can move in a second direction 127 opposite to the first direction 126 to return to its initial position. In some embodiments, the scraping unit 123 can be moved by a control rod (not shown) or a magnet assembly (not shown) connected to the scraping unit 123. The scraping unit 123 can be moved by a drive device or manually. In some embodiments, the scraping unit 123 can be used during the operation period of the plasma apparatus 500. This can further reduce the frequency of maintenance and downtime of the plasma apparatus.

[0068] Figure 6 is a schematic cross-sectional view of a scraping unit according to one embodiment of the present disclosure. In the embodiment illustrated in Figure 6, the scraping unit 123 comprises a first blade 123a, a second blade 123b, and a connector 123c connecting the first blade 123a and the second blade 123b. The first blade 123a may be configured to move in contact with the outer surface 104d of the inner electrode 104, and the second blade 123b may be configured to move in contact with the inner surface 105d of the outer electrode 105. The first blade 123a and the second blade 123b may be made of Teflon, metal, ceramic, any suitable insulating material, or a combination thereof. In some embodiments, the second blade 123b and / or the first blade 123a may be made of iron, any suitable ferromagnetic material, or a combination thereof, thereby allowing the movement of the scraping unit 123 to be controlled by a magnetic element. In some embodiments, the connector 123c may be equipped with Teflon, ceramic, any suitable insulating material, or a combination thereof to avoid short circuits between the electrodes.

[0069] Figure 7 is a schematic diagram of a plasma apparatus according to one embodiment of the present disclosure. The plasma apparatus 701 in Figure 7 may be substantially similar to the plasma apparatus 100 in Figures 1A and 1B, where the same reference numerals indicate the same elements. As shown in Figure 7, the plasma apparatus 701 further comprises a motor 129. The motor 129 may be coupled to an inner electrode 104 and configured to provide a rotational driving force for rotating the inner electrode 104 about a first rotation axis 104c. The motor 129 may be directly or indirectly coupled to the inner electrode 104. This allows the inner electrode 104 to be rotationally driven by the motor 129. In this way, the rotation of the inner electrode mitigates the problem of solid product (e.g., carbon) accumulation on the outer surface of the inner electrode and can reduce the downtime of the plasma apparatus as described above. The rotational speed of the inner electrode 104 may be controlled by the rotational speed of the motor 129 and may be adjusted to achieve a higher conversion rate and / or higher energy efficiency. All other descriptions of the plasma apparatus and inner electrodes described above with respect to Figures 1A to 6 may also be applied here, where applicable.

[0070] Figure 8 is a schematic diagram of a plasma apparatus according to one embodiment of the present disclosure. The plasma apparatus 801 in Figure 8 may be substantially similar to the plasma apparatus 100 in Figures 1A and 1B, with the same reference numerals indicating the same elements. As shown in Figure 8, the outer electrode 105 of the plasma apparatus 801 further comprises a gas piping 130. The gas piping 130 may be embedded in the wall 105a of the outer electrode 105. In some embodiments, the outer electrode 105 may have a plurality of gas piping 130. In one embodiment, the plasma apparatus 801 may further comprise a gas intake valve 101 configured to control the flow rate of a first gas 109 into the plasma generation region 106. In some embodiments, the gas piping 130 is configured to introduce the first gas 109 into the plasma generation region 106. In other words, the first gas 109 can flow into the plasma generation region 106 via the gas piping 130. In this way, the airflow of the first gas ejected from the gas piping can mitigate the problem of solid products (e.g., carbon) accumulating on the outer surface of the inner electrode and / or the inner surface of the outer electrode, further reducing the downtime of the plasma apparatus 801. The airflow of the first gas 109 can cool the outer electrode 105 by removing heat from it, and can also cool the inner electrode 104. This can extend the service life of the outer electrode 105 and / or the inner electrode 104.

[0071] Figure 9 is a flowchart illustrating a method according to one embodiment of the present disclosure. Method 900 may be operable in the plasma apparatuses discussed above, such as plasma apparatus 100, plasma apparatus 200, plasma apparatus 500, plasma apparatus 701, and plasma apparatus 801. In some embodiments, the internal electrodes of the plasma apparatus may include any or all of the features, characteristics, and parameters discussed above with respect to Figures 2 to 4.

[0072] As shown with reference to Figures 9 and 1A to 1B, Method 900 comprises introducing a first gas 109 into the first cavity 119 through an opening 104b of the first cavity 119 (step 910). The first cavity 119 may be defined by the wall 104a of the inner electrode 104. In some embodiments, the first gas 109 comprises a hydrocarbon gas. In some embodiments, step 910 may include introducing the first gas 109 into the first cavity 119 from a gas vessel 108. In some embodiments, Method 900 may include heating the first gas 109 before it is introduced into the first cavity 119. All other descriptions relating to the plasma apparatus described above with reference to Figures 1A to 8 may also be adapted here, where applicable.

[0073] As shown with reference to Figures 9 and 1A to 1B, Method 900 comprises introducing a first gas 109 from a first cavity 119 into a plasma generation region 106 through a through-hole 118, and rotating the inner electrode 104 about a first rotation axis 104c (step 920). As described above, the plasma generation region 106 is the region between the inner electrode 104 and the outer electrode 105 surrounding the inner electrode 104. The through-hole 118 penetrates the wall 104a of the inner electrode 104. The first rotation axis 104c penetrates the first cavity 119 of the inner electrode 104. Furthermore, as shown with reference to Figures 2, 3A, and 3B, in some embodiments, rotating the inner electrode 104 comprises obtaining rotational driving force from the flow of the first gas 109 from the first cavity 119 through the through hole 118 to the plasma generation region 106, as described above. Furthermore, as shown with reference to Figure 7, in some embodiments, rotating the inner electrode 104 comprises providing rotational driving force from a motor 129 coupled to the inner electrode 104, as described above. All other descriptions of the plasma apparatus and inner electrode described above with reference to Figures 1A to 8 may also be adapted here, where applicable.

[0074] As shown with reference to Figures 9 and 1A to 1B, Method 900 comprises generating plasma in a plasma generation region 106 by applying a voltage between an inner electrode 104 and an outer electrode 105 (step 930). In some embodiments, generating plasma comprises generating plasma from a portion of a first gas 109. In other words, this method can be carried out without introducing additional working gases (e.g., nitrogen, oxygen, argon, and air). This can increase the dissociation efficiency and product yield of this method and avoid undesirable byproducts formed by reactions with additional working gases. The plasma can be low-temperature, i.e., non-thermal plasma, and the plasma apparatus can be kept relatively low. For example, the plasma can be generated under non-thermodynamic conditions, thereby achieving an effective electron temperature of about 1000°C to about 2000°C or higher while keeping the bulk gas temperature below about 500°C. This avoids the problem that when hydrocarbons are decomposed using high temperatures, i.e., thermal plasma (for example, plasma with a bulk gas temperature of about 2000°C), high molecular weight, undesirable by-products (e.g., higher hydrocarbons, polycyclic compounds) are formed, reducing the purity of the resulting products.

[0075] As shown with reference to Figures 9 and 1A to 1B, Method 900 comprises using plasma to decompose the first gas 109 (step 940). The plasma can decompose the molecules of the first gas 109 and break the chemical bonds therein, as described above. In some embodiments, the decomposition process occurs in a plasma generation region 106. In some embodiments, Method 900 may include releasing the products generated from the decomposition of the first gas 109 from an outlet 116. In some embodiments, the products may comprise a second gas 125 and a solid product 124. In situations where the first gas 109 contains hydrocarbons, the second gas 125 may comprise hydrogen gas, and the solid product 124 may comprise solid carbon. In some embodiments, some of the undecomposed first gas 109 and / or other impurities may be released from the outlet 116. In some embodiments, the second gas 125 may comprise a decarbonized hydrocarbon gas (e.g., a mixture of hydrogen gas and hydrocarbon gas).

[0076] As shown with reference to Figures 9 and 1A to 1B, in some embodiments, method 900 may further include separating the solid product 124 from the second gas 125 by a separation device 117, as described above. In situations where the first gas 109 contains hydrocarbons, the separation device 117 may separate solid carbon from the hydrogen gas (or decarbonized hydrocarbon gas). Solid carbon can be used as an industrial raw material, such as carbon black. Furthermore, the production and separation of carbon black can be carried out without additional energy. The hydrogen gas or decarbonized hydrocarbon gas can be used for low-carbon emission power generation. In some embodiments, the hydrogen gas can be stored in the form of liquid hydrogen, compressed hydrogen, or metal hydrides.

[0077] As shown with reference to Figures 9 and 1A to 1B, in some embodiments, method 900 may further include feeding a second gas 125 into the generator 110. As shown in Figure 1A, the generator 110 may be coupled to the gas outlet 122 of the separation device 117. Thus, the second gas 125 (e.g., hydrogen gas or decarbonized hydrocarbon gas) that has passed through the separation device 117 can be discharged from the gas outlet 122 and fed into the generator 110. In one embodiment, the generator 110 may comprise a fuel cell. In one embodiment, the generator 110 may comprise a turbine or engine. In some embodiments, as described above, the airtight design of the insulating layer 103 and / or bottom cover 111 allows the second gas 125 to be fed into the generator 110 at the required gas pressure (e.g., atmospheric pressure or a higher pressure such as 100 bar) without passing through a pump or compressor. The feeding pressure of the second gas 125 may be controlled, for example, by a gas intake valve 101.

[0078] As shown with reference to Figures 9 and 1A to 1B, and further with reference to Figure 2, in some embodiments, method 900 may further include cooling the inner electrode 104 by a flow of the first gas 109 from the first cavity 119 to the plasma generation region 106 through the through hole 118, as described above, but for simplicity, the relevant description is omitted. In some embodiments, the plasma apparatus may function without an additional cooling system. All other descriptions of the plasma apparatus described above with reference to Figures 1A to 8 may also be adapted here, where applicable.

[0079] As shown with reference to Figures 9 and 1A to 1B, and further with reference to Figures 5A to 6, in some embodiments, method 900 may further include removing solid products 124 adhering to the inner electrode 104 by a scraping unit 123, as described above, but for simplicity, the relevant description is omitted. All other descriptions of the plasma apparatus described above with reference to Figures 1A to 8 may also be applied here, where applicable.

[0080] As shown with reference to Figures 9 and 1A to 1B, and further with reference to Figure 8, in some embodiments, method 900 may further include introducing a first gas 109 into the plasma generation region 106 through a gas pipe 130 embedded in the wall 105a of the outer electrode 105, as described above, but for simplicity, the relevant description is omitted. All other descriptions of the plasma apparatus described above with reference to Figures 1A to 8 may also be adapted here, where applicable.

[0081] The above-described embodiments are provided to enable those skilled in the art to manufacture and use the subject matter. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the novel principles and subject matter disclosed herein may be applied to other embodiments without using innovative features. The subject matter described in the claims is not intended to be limited to the embodiments illustrated herein, but should be given the broadest scope consistent with the principles and novel features disclosed herein. Additional embodiments are considered to be within the spirit and true scope of the disclosed subject matter. Accordingly, the present invention is intended to cover modifications and changes that fall within the scope of the appended claims and their equivalents.

Claims

1. It is a plasma device, An inner electrode having a wall defining a first cavity, wherein the opening of the first cavity is configured to receive a first gas, the inner electrode is rotatable about a first axis of rotation, and the first axis of rotation penetrates the first cavity, and the inner electrode is characterized in that The system comprises an outer electrode surrounding the inner electrode, A plasma apparatus characterized in that the inner electrode has a through hole penetrating the wall of the inner electrode, and the first cavity is in fluid communication with the plasma generation region between the inner electrode and the outer electrode through the through hole.

2. The plasma apparatus according to claim 1, characterized in that both the inner electrode and the outer electrode are substantially tubular.

3. The plasma apparatus according to claim 1, characterized in that the outer electrode is arranged coaxially with the inner electrode.

4. The plasma apparatus according to claim 1, further comprising a rotating member mechanically coupled to the inner electrode so that the inner electrode can rotate about a first rotation axis.

5. The plasma apparatus according to claim 4, characterized in that the rotating member comprises a bearing or a rotor.

6. The plasma apparatus according to claim 1, further comprising a motor coupled to the inner electrode and configured to provide a rotational driving force for rotating the inner electrode about a first rotation axis.

7. The plasma apparatus according to claim 1, wherein the through-hole is configured to obtain a rotational driving force from the first gas flow from the first cavity to the plasma generation region through the through-hole, and the rotational driving force causes the inner electrode to rotate about the first rotation axis.

8. The plasma apparatus according to claim 1, characterized in that the first angle between the extension direction of the through hole on the cross-sectional plane of the inner electrode and the radial direction extending from a point on the longitudinal axis of the inner electrode in the through hole to the through hole is between 5 degrees and 85 degrees, and the cross-sectional plane is perpendicular to the longitudinal axis of the inner electrode.

9. The plasma apparatus according to claim 1, characterized in that the second angle between the extension direction of the through hole and the axial direction is between 5 degrees and 85 degrees, the axial direction coincides with the longitudinal axis of the inner electrode and extends from a point in the first cavity toward the opening of the first cavity.

10. The plasma apparatus according to claim 1, further comprising a gas inlet configured to allow the flow of the first gas into the first cavity.

11. The plasma apparatus according to claim 10, further comprising a gas container coupled to the gas inlet, wherein the gas container contains the first gas.

12. The plasma apparatus according to claim 1, further comprising an insulating layer arranged in an annular shape between the outer electrode and the inner electrode.

13. The plasma apparatus according to claim 1, further comprising a power supply electrically connected to both the inner electrode and the outer electrode, wherein the power supply is configured to provide a voltage between the inner electrode and the outer electrode.

14. The plasma apparatus according to claim 1, further comprising a scraping unit configured to move in contact with the outer surface of the inner electrode.

15. The plasma apparatus according to claim 14, characterized in that the scraping unit surrounds the outer surface of the inner electrode and is configured to move in a first direction along the longitudinal axis of the inner electrode and in a second direction opposite to the first direction.

16. The plasma apparatus according to claim 15, characterized in that the scraping unit comprises a first blade, a second blade, and a connector connecting the first blade and the second blade, wherein the first blade is configured to move in contact with the outer surface of the inner electrode, and the second blade is configured to move in contact with the inner surface of the outer electrode.

17. The plasma apparatus according to claim 1, further comprising an outlet configured to discharge a second gas and solid products generated from the first gas.

18. The plasma apparatus according to claim 17, further comprising a separation device connected to the outlet, wherein the separation device is configured to separate the solid product from the second gas.

19. The plasma apparatus according to claim 18, characterized in that the separation device comprises a dust collector and a filter screen connected to the dust collector.

20. The plasma apparatus according to claim 17, further comprising a bottom cover connected to the outer electrode at the end of the outer electrode, and the outlet being located in the bottom cover.

21. The plasma apparatus according to claim 1, characterized in that the outer electrode comprises a gas pipe embedded in the wall of the outer electrode, and the gas pipe is configured to introduce the first gas into the plasma generation region.

22. The plasma apparatus according to claim 1, characterized in that the first gas comprises a hydrocarbon gas.

23. It is a method, Introducing a first gas into the first cavity defined by the wall of the inner electrode through the opening of the first cavity, The first gas is flowed from the first cavity through a through-hole penetrating the wall of the inner electrode into the plasma generation region between the inner electrode and the outer electrode surrounding the inner electrode, By applying a voltage between the inner electrode and the outer electrode, plasma is generated in the plasma generation region. Decomposing the first gas using the plasma, A method comprising rotating the inner electrode about a first rotation axis, wherein the first rotation axis penetrates the first cavity.

24. The method according to claim 23, characterized in that generating the plasma comprises generating the plasma from a portion of the first gas.

25. The method according to claim 23, characterized in that the first gas comprises a hydrocarbon gas.

26. The method according to claim 23, further comprising discharging the product generated from the decomposition of the first gas from an outlet.

27. The method according to claim 26, characterized in that the product comprises a second gas and a solid product.

28. The method according to claim 27, further comprising separating the solid product from the second gas using a separation device.

29. The method according to claim 27, further comprising introducing the second gas into a generator.

30. The method according to claim 23, characterized in that the rotation of the inner electrode is performed by obtaining a rotational driving force from the first gas flow from the first cavity to the plasma generation region through the through hole.

31. The method according to claim 23, characterized in that the rotation of the inner electrode is provided by a motor coupled to the inner electrode.

32. The method according to claim 23, further comprising removing solid products adhering to the inner electrode by a scraping unit.

33. The method according to claim 23, further comprising cooling the inner electrode by a first gas flow from the first cavity through the through hole to the plasma generation region.

34. The method according to claim 23, characterized in that introducing the first gas comprises introducing the first gas from a gas container into the first cavity.

35. The method according to claim 23, further comprising heating the first gas before it is introduced into the first cavity.

36. The method according to claim 23, further comprising introducing the first gas into the plasma generation region through a gas pipe embedded in the wall of the outer electrode.

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