Plasma device and gas cracking method

Abstract

The invention 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, and an opening of the first cavity 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 such that the first cavity is in fluid communication with a plasma generation region through the through hole, the plasma generation region being located between the inner electrode and the outer electrode. The inner electrode is rotatable about a first axis of rotation, and the first axis of rotation extends through the first cavity. Some embodiments of the present disclosure particularly relate to a plasma apparatus and a gas cracking method.

Description

[0001] Cross-references

[0002] 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 Gases,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to plasma devices and methods. Some embodiments of the present disclosure relate particularly to plasma devices and gas cracking methods. Background Art

[0004] Plasma is considered to be the fourth state of matter in addition to 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. Using high-energy particles in plasma to interact with matter can lead to enhanced reactions. According to the operating environment and working pressure, plasma can be divided into vacuum plasma, atmospheric plasma and high-pressure plasma, each with its own application field. For example, vacuum plasma is generally used for coating. The material to be coated is made into a target and placed on the cathode. An additional gas such as argon is used as a working gas (or carrier gas), and a voltage is applied to generate plasma from the working gas. The plasma is used to impact the target so that the material is sputtered onto the substrate to be coated, thereby achieving coating on the substrate. Atmospheric plasma is generally used for surface modification or cleaning. The working gas used for atmospheric plasma treatment may include nitrogen, oxygen, argon, air or a combination of the foregoing gases, which are used to generate plasma at atmospheric pressure. The generated plasma is generally applied to the surface of an object for surface treatment applications.

[0005] When using plasma to crack hydrocarbons into hydrogen and carbon, the carbon generated during the cracking process will coat the electrodes, which will stop plasma generation and plasma cracking of hydrocarbons. To avoid this problem, nitrogen, oxygen, argon, air, or a combination of the foregoing gases are used as the main working gas to generate the plasma. As a result, in some cases, only a small amount (e.g., less than 10%) of hydrocarbon gas can enter the device, and the dissociation efficiency and product yield are relatively low. Summary of the invention

[0006] The present disclosure provides a plasma device. The plasma device includes an inner electrode and an outer electrode. The inner electrode includes a wall defining a first cavity, and an opening of the first cavity 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, so that the first cavity is in fluid communication with a plasma generation region through the through hole, and the plasma generation region is located between the inner electrode and the outer electrode. The inner electrode can rotate around a first rotation axis, and the first rotation axis extends through the first cavity.

[0007] In one embodiment, the inner electrode and the outer electrode are both substantially tubular.

[0008] In one embodiment, the outer electrode and the inner electrode are coaxially arranged.

[0009] In one embodiment, the plasma device further includes a rotating element mechanically coupled to the inner electrode such that the inner electrode can rotate about the first rotation axis.

[0010] In one embodiment, the rotating element includes a bearing or a rotor.

[0011] In one embodiment, the plasma apparatus further includes a motor coupled to the inner electrode, the motor being configured to provide a rotational driving force to rotate the inner electrode around the first rotation axis.

[0012] In one embodiment, the through hole is configured to obtain a rotational driving force from a gas flow of the first gas from the first cavity through the through hole to the plasma generation region, and the rotational driving force rotates the inner electrode around the first rotation axis.

[0013] In one embodiment, on a cross section of the inner electrode, a first angle between an extension direction of the through hole and a radial direction of the through hole is between about 5 degrees and about 85 degrees, and the cross section is perpendicular to a longitudinal axis of the inner electrode.

[0014] In one embodiment, a second angle between an extension direction of the through hole and an axial direction is between about 5 degrees and about 85 degrees, the axial direction coincides with a longitudinal axis of the inner electrode and extends from a point in the first cavity to the opening of the first cavity.

[0015] In one embodiment, the plasma device further includes a gas inlet configured to allow the first gas to flow into the first cavity.

[0016] In one embodiment, the plasma device further includes a gas container coupled to the gas inlet, and the gas container contains the first gas.

[0017] In one embodiment, the plasma device further includes an insulating layer annularly disposed between the outer electrode and the inner electrode.

[0018] In one embodiment, the plasma apparatus further includes a power supply electrically connected to both the inner electrode and the outer electrode, and the power supply is configured to provide a voltage between the inner electrode and the outer electrode.

[0019] In one embodiment, the plasma apparatus further includes a scraping unit configured to contact an outer surface of the inner electrode and move relative to the outer surface of the inner electrode.

[0020] In one embodiment, the scraping unit surrounds the outer surface of the inner electrode and is configured to move in a first direction along a longitudinal axis of the inner electrode and in a second direction opposite to the first direction.

[0021] In one embodiment, the scraping unit includes a first scraper, a second scraper, and a connecting member connecting the first scraper and the second scraper. The first scraper is configured to contact the outer surface of the inner electrode and move relative to the outer surface of the inner electrode, and the second scraper is configured to contact an inner surface of the outer electrode and move relative to the inner surface of the outer electrode.

[0022] In one embodiment, the plasma device further includes an outlet configured to output a second gas and a solid product, wherein the second gas and the solid product are generated from the first gas.

[0023] In one embodiment, the plasma device further comprises a separation device connected to the outlet, wherein the separation device is configured to separate the solid product from the second gas.

[0024] In one embodiment, the separation device includes a dust collector and a filter connected to the dust collector.

[0025] In one embodiment, the plasma device further includes a bottom cover connected to the outer electrode at one end of the outer electrode, and the outlet is disposed at the bottom cover.

[0026] In one embodiment, the outer electrode includes a gas conduit embedded in a wall of the outer electrode, and the gas conduit is configured to introduce the first gas into the plasma generation region.

[0027] In one embodiment, the first gas includes a hydrocarbon gas.

[0028] The present disclosure provides a method. The method includes introducing a first gas into the first cavity through an opening of a first cavity, the first cavity being defined by a wall of an inner electrode. The method includes flowing the first gas from the first cavity through a through hole extending through the wall of the inner electrode to a plasma generation region, the plasma generation region being located between the inner electrode and an outer electrode surrounding the inner electrode. The method includes generating a plasma in the plasma generation region by applying a voltage between the inner electrode and the outer electrode. The method includes cracking the first gas using the plasma. The method includes rotating the inner electrode about a first rotation axis, and the first rotation axis extends through the first cavity.

[0029] In one embodiment, generating the plasma includes generating the plasma from a portion of the first gas.

[0030] In one embodiment, the first gas includes a hydrocarbon gas.

[0031] In one embodiment, the method further includes outputting a product from an outlet, the product being produced by cracking the first gas.

[0032] In one embodiment, the product includes a second gas and a solid product.

[0033] In one embodiment, the method further comprises separating the solid product from the second gas by a separation device.

[0034] In one embodiment, the method further comprises inputting the second gas into a generator.

[0035] In one embodiment, rotating the inner electrode includes obtaining a rotational driving force from a gas flow of the first gas from the first cavity through the through hole to the plasma generation region.

[0036] In one embodiment, rotating the inner electrode includes providing a rotational driving force by a motor coupled to the inner electrode.

[0037] In one embodiment, the method further comprises removing a solid product attached to the inner electrode by a scraping unit.

[0038] In one embodiment, the method further comprises cooling the inner electrode by a gas flow of the first gas from the first cavity through the through hole to the plasma generation region.

[0039] In one embodiment, introducing the first gas includes introducing the first gas from a gas container into the first cavity.

[0040] In one embodiment, the method further comprises heating the first gas before the first gas is introduced into the first cavity.

[0041] In one embodiment, the method further includes introducing the first gas into the plasma generation region through a gas pipeline embedded in a wall of the outer electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1A and Figure 1B FIG. 4 is a schematic diagram of a plasma device according to an embodiment of the present disclosure.

[0043] Figure 2 FIG. 4 is a schematic diagram of a plasma device according to an embodiment of the present disclosure.

[0044] Figure 3A and Figure 3B is a schematic diagram of an inner electrode according to an embodiment of the present disclosure.

[0045] Figure 4 is a schematic diagram of an inner electrode according to an embodiment of the present disclosure.

[0046] Figure 5A and Figure 5B Schematic diagram of a scraping unit according to an embodiment of the present disclosure.

[0047] Figure 6 It is a cross-sectional schematic diagram of a scraping unit according to an embodiment of the present disclosure.

[0048] Figure 7 FIG. 4 is a schematic diagram of a plasma device according to an embodiment of the present disclosure.

[0049] Figure 8 FIG. 4 is a schematic diagram of a plasma device according to an embodiment of the present disclosure.

[0050] Fig. 9 is a flow chart of a method according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0051] The words used in this article are used to describe the details of a specific embodiment of the present invention, and all words should be interpreted reasonably in the broadest sense. Certain words will be particularly emphasized below; any restrictive terms will be defined by the specific embodiments. In the present invention, the components and functions of the plasma device can be described by the following figures and embodiments, but the size and shape of the plasma device shown in the figures do not limit the technical features of the present invention.

[0052] The term "located on..." in this specification may mean directly in contact with or indirectly located on an intermediate element or intermediate layer. Spatially relative terms such as "beneath", "below", "lower", "above", "upper" and other relative terms may be used herein to conveniently describe the relationship between an element or feature in the drawings and another (other) element or feature. In addition to the orientation described in the drawings, these spatially relative terms are intended to include different orientations of device use or operation. For example, when the device in the drawings is turned upside down, the elements described as being "below" or "below" other elements or features will become positioned "above" the other elements or features. Therefore, the term "below" in the example includes both the above and below directions. These devices may be positioned in another manner (rotated 90 degrees or in other orientations), so the spatially relative symbols used herein can be interpreted in the same manner.

[0053] Figure 1A and Figure 1B FIG. 4 is a schematic diagram of a plasma device according to an embodiment of the present disclosure. Figure 1B for Figure 1A Schematic diagram of the cross section of the plasma device along the A-A' line. Figure 1A and Figure 1B As shown, the plasma device 100 includes an inner electrode 104 and an outer electrode 105. The inner electrode 104 includes a wall 104a defining a first cavity 119, wherein an 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 located between the inner electrode 104 and the outer electrode 105. The inner electrode 104 may have a through hole 118 extending through the wall 104a of the inner electrode 104, so that the first cavity 119 is in fluid communication with the plasma generation region 106 through the through hole 118, and the plasma generation region 106 is located between the inner electrode 104 and the outer electrode 105. In this way, the first gas 109 can flow into the first cavity 119 through the opening 104b, and then flow into the plasma generation region 106 through the through hole 118. In some embodiments, the inner electrode 104 may have a plurality of through holes 118 extending through the wall 104a of the inner electrode 104.

[0054] The inner electrode 104 may include stainless steel, copper, graphite, molybdenum, aluminum, any suitable conductive material, or a combination thereof. The outer electrode 105 may include stainless steel, aluminum, any suitable conductive material, or a combination thereof. Figure 1A and Figure 1BIn the illustrated embodiment, the inner electrode 104 is substantially tubular-shaped, 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 may be closed, wherein the second end 104f is opposite to the first end 104e. However, the present disclosure is not limited thereto. The outer electrode 105 may also be substantially tubular-shaped. In some embodiments, the outer electrode 105 and the inner electrode 104 are arranged coaxially. In some embodiments, the gap between the inner electrode 104 and the outer electrode 105 is of a fixed size. Although the inner electrode 104 and the outer electrode 105 are shown as having a fixed radius along their longitudinal axis, in some embodiments, the radius 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 shaped.

[0055] like Figure 1A and Figure 1B As shown, 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 less than the length of the outer electrode 105. In some embodiments, the inner electrode 104 may have a length of about 20 millimeters (mm) to about 300 millimeters. In some embodiments, the outer electrode 105 may have a length of about 30 millimeters to about 500 millimeters. The inner electrode 104 may have an inner diameter 104i of about 5 millimeters to about 50 millimeters and an outer diameter 104o of about 20 millimeters to about 70 millimeters. The wall 104a of the inner electrode 104 may have a thickness of about 7.5 millimeters to about 10 millimeters. The outer electrode 105 may have an inner diameter 105i of about 25 millimeters to about 100 millimeters and an outer diameter 105o of about 30 millimeters to about 110 millimeters. The wall 105a of the outer electrode 105 may have a thickness of about 2.5 millimeters to about 5 millimeters. These values ​​are for illustrative purposes only and are not intended to limit the present disclosure.

[0056] The inner electrode 104 can rotate about a first rotation axis 104c, wherein the first rotation axis 104c extends through the first cavity 119 of the inner electrode 104. In some embodiments, the first rotation axis 104c can be aligned with the longitudinal axis (e.g., Figure 3A , Figure 3B and Figure 4In other words, the inner electrode 104 can rotate about its longitudinal axis. The longitudinal axis referred to herein can refer to an axis along the length direction, for example, along the direction from the first end 104e to the second end 104f of the inner electrode 104, and passing through its center of gravity. Specifically, the plasma device 100 is configured so that the inner electrode 104 can be driven to rotate, especially when the plasma device 100 is in operation. In some embodiments, the plasma device further includes a device, such as a motor (at Figure 7 In some embodiments, the inner electrode may be configured to be driven to rotate by a gas flow of the first gas that passes through the wall of the inner electrode (at Figure 3A and Figure 3B ). As a result, the problem of solid product accumulation on the outer surface of the inner electrode 104 during the plasma pyrolysis process can be alleviated, and the plasma device 100 can continue to operate for a reasonable period of time without the introduction of additional working gas. Therefore, the dissociation efficiency and yield can be increased, and the formation of undesirable side products by reaction with the additional working gas can be avoided. In addition, the frequency of plasma device maintenance and downtime caused by the accumulation of solid products can be reduced.

[0057] like Figure 1A and Figure 1B As shown, the plasma device 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 is configured to enable the first gas 109 to flow into the first cavity 119. In some embodiments, the plasma device 100 further includes a gas container 108. The gas container 108 may contain the first gas 109, and may be coupled to the gas inlet 102 to provide the first gas 109 into the first cavity 119 for plasma cracking. In some embodiments, the gas container 108 may be a pressurized gas container. In one embodiment, the plasma device 100 may further include a gas-intake valve 101 configured to control the flow rate of the first gas 109 into the first cavity 119.

[0058] In some embodiments, the first gas 109 includes 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 include 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. The hydrocarbon liquid may be vaporized to a gaseous state by heating in a vaporizer. In some embodiments, the first gas 109 is pure or substantially pure hydrocarbons, wherein impurities may need to be filtered out to provide substantially pure hydrocarbons. 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 pre-heated before flowing into the first cavity 119, so that the dissociation efficiency of the first gas 109 generated thereby may be increased. For example, the first gas 109 may flow through a waste-heat recycling system and be heated by waste heat recovered from a power plant.

[0059] In such Figure 1A In the illustrated embodiment, the plasma device 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 the first gas 109. The plasma can cleave molecules of the first gas 109 and break their chemical bonds. As a result, the first gas 109 can be dissociated, and products (e.g., the second gas 125 and the solid product 124) can be generated. In the case where the first gas includes hydrocarbons, the hydrocarbon molecules can be dissociated, and carbon and hydrogen can be generated.

[0060] In some embodiments, the power supply 107 includes a DC power supply and / or an AC power supply. Figure 1AIn the illustrated embodiment, the outer electrode 105 may be grounded. In some embodiments, the voltage and / or frequency of the power supply may be adjusted to achieve a higher conversion rate and / or greater energy efficiency.

[0061] In such Figure 1A In the illustrated embodiment, the plasma device 100 may further include an insulating layer 103 between the outer electrode 105 and the inner electrode 104. The insulating layer 103 may be configured in an annular shape and may wrap around 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 include Teflon, ceramics, any suitable insulating material, or a combination thereof. In some embodiments, the insulating layer 103 provides a gas-tight seal to prevent gas (e.g., the first gas 109 and the second gas 125) from leaking from a gap between the inner electrode 104 and the outer electrode 105.

[0062] In such Figure 1A In the illustrated embodiment, the plasma device 100 may further include a bottom cover 111 connected to the outer electrode 105. Specifically, as shown in FIG. Figure 1A As shown, the insulating layer 103 is coupled to the outer electrode 105 at the first end 105e of the outer electrode 105, and the bottom cover 111 is connected to the outer electrode 105 at the second end 105f of the outer electrode 105, wherein the second end 105f is opposite to the first end 105e. In some embodiments, the bottom cover 111 may include a non-conductive material, such as quartz, glass, plastic, any suitable insulating material, and a combination thereof. In some embodiments, the bottom cover 111 may include a conductive material, such as stainless steel, any suitable conductive material, and a combination thereof. The bottom cover 111 may be connected to the outer electrode 105 by a gasket, adhesives, welding, and / or other suitable methods. The connection between the bottom cover 111 and the outer electrode 105 may be airtight. Through the airtight configuration, the plasma device can be operated without an additional housing, the dissociation efficiency of the first gas can be improved, and the gas pressure in the outer electrode can be set to a higher pressure (e.g., 100 bar, depending on the airtightness of the plasma device) and is easy to control. By using a gasket or welding, the connection between the bottom cover 111 and the outer electrode 105 can form a strong airtight seal. Figure 1A As shown, the plasma device 100 further includes an outlet 116. The outlet 116 is configured to output the second gas 125 and the solid product 124 produced from the first gas 109. Figure 1AIn the illustrated embodiment, the outlet 116 is disposed on the bottom cover 111. However, the present disclosure is not limited thereto.

[0063] In such Figure 1A In the illustrated embodiment, the plasma device 100 further includes a separation device 117 connected to the outlet 116. The separation device 117 is configured to separate the solid product 124 from the second gas 125. Figure 1A As shown, the separation device 117 may include a dust collector 120 and a filter screen 121 connected to the dust collector 120. In an embodiment in which the first gas 109 includes a hydrocarbon gas, the separation device 117 may separate solid carbon from hydrogen for subsequent use. For example, the separated solid carbon can be used as an industrial raw material, and the hydrogen 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 intercept fine carbon powder that is not collected by the dust collector 120. The second gas 125 (e.g., hydrogen) passing through the separation device 117 can be discharged from the gas outlet 122. In some embodiments, the dust collector 120 and the filter screen 121 can be selected so that solid carbon with a desired particle size can be collected for various applications.

[0064] In such Figure 1A In the illustrated embodiment, the separation device 117 can be connected to the outlet 116 via a four-way pipe 113. An outlet pressure gauge 115 can also be connected to the four-way pipe 113 to detect the output pressure of the gas output from the outlet 116. In some embodiments, a sampling port 114 can also be connected to the outlet 116 via the four-way pipe 113. The sampling port 114 can be used to monitor the composition and dissociation efficiency of the output gas, etc., so that feedback can be provided to the plasma device 100.

[0065] like Figure 1A As shown, the plasma device 100 can be placed vertically. In some embodiments, by placing the plasma device 100 in a vertical direction, the efficiency of separating the solid product 124 (e.g., solid carbon) from the second gas 125 (e.g., hydrogen) can be improved, for example, by gravity-assisted separation of the heavier solid product 124 from the lighter second gas 125. For example, Figure 1A As shown, the plasma device 100 may further include a reactant collection region 112 below the plasma generation region 106. Due to gravity, the solid product 124 may settle in the reactant collection region 112. Other orientations of the plasma device 100 are also possible (eg, horizontal orientation).

[0066] Figure 2FIG. 4 is a schematic diagram of a plasma device according to an embodiment of the present disclosure. Figure 2 The plasma device 200 may be substantially similar to Figure 1A and Figure 1B The plasma device 100 of FIG. 1 is shown in FIG. 1 , wherein the same reference numerals indicate the same elements. Figure 2 As shown, the plasma device 200 further includes a rotating element 203. The rotating element 203 is mechanically coupled to the inner electrode 104 so that the inner electrode 104 can rotate around the first rotation axis 104c. The rotating element 203 is a mechanical element that limits the movement of the inner electrode 104 within a desired rotation range. The rotating element 203 can also provide mechanical support for the inner electrode 104. In some embodiments, the rotating element 203 includes a bearing. In some embodiments, the rotating element 203 includes a rotor. The rotor can be driven to rotate by the interaction between the rotor and the corresponding stator. However, the present disclosure is not limited thereto.

[0067] In such Figure 2 In the illustrated embodiment, the rotating element 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 element 203 may be fixed to the insulating layer 103, the outer electrode 105, or the housing (if present). The present disclosure is not limited thereto. Figure 2 As shown, the rotating element 203 may surround the inner electrode 104. The rotating element 203 may be disposed between the inner electrode 104 and the outer electrode 105. In some embodiments, the rotating element 203 may be configured as a ring. In some embodiments, the rotating element 203 may be configured to receive a rotational driving force that drives the inner electrode 104 to rotate around the first rotation axis 104c.

[0068] like Figure 2 As shown, the inner electrode 104 has a plurality of through holes 118 extending through the wall 104a of the inner electrode 104. In some embodiments, the through holes 118 of the inner electrode 104 are configured to obtain a rotational driving force from the gas flow of the first gas 109, wherein the rotational driving force rotates the inner electrode 104 around the first rotation axis 104c. Specifically, one or more through holes 118 may be configured to have an extension direction (at Figure 3A and Figure 3B), so that when the first gas 109 flows from the first cavity 119 through the through hole 118 to the plasma generation region 106, its gas flow can provide a rotational driving force to rotate the inner electrode 104 around the first rotation axis 104c. In this way, the inner electrode 104 can be driven to rotate by the gas flow of the first gas 109 (e.g., hydrocarbon gas). In this way, due to the rotation of the inner electrode and / or the gas flow of the first gas ejected from the through hole, the problem of solid products (e.g., carbon) accumulating on the outer surface of the inner electrode can be alleviated, and the plasma device can continue to operate for a reasonable period of time without introducing additional working gas; in addition, the downtime of the plasma device can be reduced. Due to the gas flow of the first gas ejected from the through hole, the problem of solid products (e.g., carbon) accumulating on the inner surface of the outer electrode can also be alleviated. The gas flow of the first gas 109 can also take away the heat of the inner electrode 104 to cool the inner electrode 104, and can also cool the outer electrode 105. In this way, the service life of the inner electrode 104 and / or the outer electrode 105 can be extended.

[0069] In some embodiments, the rotation speed of the inner electrode 104 may be between about 30 rotations per minute (rpm) and about 180 rpm. However, the present disclosure is not limited thereto. In some embodiments, the rotation speed of the inner electrode 104 may be less than 30 rpm or greater than 180 rpm. The rotation speed of the inner electrode 104 may vary due to its size or material, the arrangement and configuration of the through holes 118, etc. The rotation speed may be controlled by the flow rate of the first gas 109 and may be adjusted to achieve a higher conversion rate and / or greater energy efficiency. In some examples, such rotation may extend the operating time of the plasma device from one minute to about seven days, or even to about one month. These values ​​are for illustrative purposes only and are not intended to limit the present disclosure.

[0070] Figure 3A is a schematic diagram of an inner electrode according to an embodiment of the present disclosure. Figure 3B for Figure 3A A schematic cross-sectional view of the inner electrode 104 along the cross section 104 h , wherein the cross section 104 h is perpendicular to the longitudinal axis 104 n of the inner electrode 104 . Figure 3A and Figure 3B The inner electrode 104 may be substantially similar to Figure 1A , Figure 1B and Figure 2 The inner electrode 104 is shown in FIG. 1 , wherein the same reference numerals indicate the same elements. Figure 3A In the illustrated embodiment, the inner electrode 104 has twelve through holes 118 arranged in three columns, each column including four through holes 118, and evenly distributed on the circumference (eg, Figure 3BAs shown, the angle between adjacent through holes 118 is substantially 90 degrees). In some embodiments, a row of through holes 118 may include one to twelve through holes 118, and are evenly or unevenly distributed on the circumference. The number and distribution of through holes 118 may vary according to actual needs. In some embodiments, the distance 118d between adjacent rows of through holes 118 may be between about 5 mm and about 50 mm. In some embodiments, the opening shape of the through hole 118 on the wall 104a may be circular. In some embodiments, the opening diameter of the through hole 118 on the wall 104a may be between about 0.5 mm and about 25 mm. These values ​​are for illustration only and are not intended to limit the present disclosure.

[0071] In some embodiments, the through holes 118 may be arranged to extend the residence time of the first gas 109 in the plasma generation region 106. The extended residence time may result in a greater dissociation efficiency of the first gas 109. For example, the distribution of the through holes 118 near the opening 104b may be denser (e.g., a row may include more through holes and / or the distance between adjacent rows may be shorter), thereby increasing the residence time of the first gas 109 and the resulting dissociation efficiency.

[0072] like Figure 3B As shown, the extension direction 118f (extension direction) of the through hole 118 and the projection of the radial direction 118r (radial direction) on the cross section 104h form an angle, wherein 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 to the plasma generation region 106, and the cross section 104h refers to a plane perpendicular to the longitudinal axis 104n of the inner electrode 104. In this way, when the first gas 109 flows from the first cavity 119 through the through hole 118 to the plasma generation region 106, the gas flow can provide a rotational driving force to rotate the inner electrode 104 around the first rotation axis 104c, and the inner electrode 104 can rotate without an additional driving device.

[0073] In some embodiments, on the cross section 104h of the inner electrode 104, the first angle θ1 between the extension direction 118f of the through hole 118 and the radial direction 118r of the through hole 118 is between about 5 degrees and about 85 degrees. However, the present disclosure is not limited thereto. In some embodiments, the first angle θ1 may be less than 5 degrees or greater than 85 degrees. The first angle θ1 may be adjusted to achieve the desired rotation 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 for illustration only and are not intended to limit the present disclosure.

[0074] Figure 4is a schematic diagram of an inner electrode according to an embodiment of the present disclosure. Figure 4 The inner electrode 204 may be substantially similar to Figures 1A to 3B The inner electrode 104 is shown in FIG. 1 , wherein the same reference numerals indicate the same elements. Figure 4 As shown, the through hole 118 can be configured to extend upward to extend the residence time of the first gas 109 in the plasma generation region 106. The extended residence time can result in a greater 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, wherein the axial direction 104x coincides with the longitudinal axis 104n of the inner electrode 204 and extends from a point 104p in the first cavity 119 to the opening 104b of the first cavity 119. In some embodiments, the second angle θ2 can be less than 5 degrees or greater than 85 degrees. The second angle θ2 can be adjusted to achieve a greater dissociation efficiency. In some embodiments, the second angle θ2 is between about 0 degrees and about 45 degrees. These values ​​are only illustrative and are not intended to limit the present disclosure.

[0075] Figure 5A and Figure 5B Schematic diagram of a scraping unit according to an embodiment of the present disclosure. Figure 5A and Figure 5B The plasma device 500 may be substantially similar to Figure 1A and Figure 1B The plasma device 100 of FIG. 1 is shown in FIG. 1 , wherein the same reference numerals indicate the same elements. Figure 5A and Figure 5B In the illustrated embodiment, the plasma device 500 further includes a scraping unit 123. The scraping unit 123 is configured to contact the outer surface 104d of the inner electrode 104 and move relative to the outer surface 104d of the inner electrode 104. The scraping unit 123 may also be configured to contact the inner surface 105d of the outer electrode 105 and move relative to 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 and a second direction 127 along the longitudinal axis 104n of the inner electrode 104, wherein the second direction 127 is opposite to the first direction 126. In some embodiments, the accumulated 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 may stop the plasma device 500 from generating plasma. The scraping unit 123 may be used to remove the solid product 124 attached to the inner electrode 104 and / or the outer electrode 105 , so that the operation of the plasma device 500 and the plasma decomposition of the first gas 109 may be maintained.

[0076] like Figure 5A and Figure 5B As shown, 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 and return to an initial position. In some embodiments, the scraping unit 123 can be moved by a control rod (not shown) or a magnet group (not shown) connected to the scraping unit 123. The scraping unit 123 can be moved by an actuation device or can be moved manually. In some embodiments, the scraping unit 123 can be used during the operation of the plasma device 500. In this way, the frequency of maintenance and shutdown of the plasma device can be further reduced.

[0077] Figure 6 FIG. 1 is a cross-sectional schematic diagram of a scraping unit according to an embodiment of the present disclosure. Figure 6 In the illustrated embodiment, the scraping unit 123 includes a first scraper 123a, a second scraper 123b, and a connector 123c connecting the first scraper 123a and the second scraper 123b. The first scraper 123a may be configured to contact the outer surface 104d of the inner electrode 104 and move relative to the outer surface 104d of the inner electrode 104, and the second scraper 123b may be configured to contact the inner surface 105d of the outer electrode 105 and move relative to the inner surface 105d of the outer electrode 105. The first scraper 123a and the second scraper 123b may include Teflon, metal, ceramic, any suitable insulating material, or a combination of the foregoing. In some embodiments, the second scraper 123b and / or the first scraper 123a may include iron, any suitable ferromagnetic material, or a combination of the foregoing, so that the movement of the scraping unit 123 can be controlled by a magnetic element. In some embodiments, the connector 123c may include Teflon, ceramic, any suitable insulating material, or a combination of the foregoing to avoid short circuits between electrodes.

[0078] Figure 7 FIG. 4 is a schematic diagram of a plasma device according to an embodiment of the present disclosure. Figure 7 The plasma device 701 may be substantially similar to Figure 1A and Figure 1B The plasma device 100 of FIG. 1 is shown in FIG. 1 , wherein the same reference numerals indicate the same elements. Figure 7As shown, the plasma device 701 also includes a motor 129. The motor 129 can be coupled to the inner electrode 104 and is configured to provide a rotational driving force to rotate the inner electrode 104 around the first rotation axis 104c. The motor 129 can be directly or indirectly coupled to the inner electrode 104. In this way, the inner electrode 104 can be driven to rotate by the motor 129. In this way, due to the rotation of the inner electrode, the problem of accumulation of solid products (such as carbon) on the outer surface of the inner electrode can be alleviated, and the downtime of the plasma device can be reduced as described above. The rotation speed of the inner electrode 104 can be controlled by the rotation speed of the motor 129, and can be adjusted to achieve a higher conversion rate and / or greater energy efficiency. If applicable, the above-mentioned Figures 1A to 6 All other descriptions regarding the plasma device and the inner electrode in are applicable here.

[0079] Figure 8 FIG. 4 is a schematic diagram of a plasma device according to an embodiment of the present disclosure. Figure 8 The plasma device 801 may be substantially similar to Figure 1A and Figure 1B The plasma device 100 of FIG. 1 is shown in FIG. 1 , wherein the same reference numerals indicate the same elements. Figure 8 As shown, the outer electrode 105 of the plasma device 801 further includes a gas pipeline 130. The gas pipeline 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 pipelines 130. In one embodiment, the plasma device 801 may further include a gas inlet valve 101 configured to control the flow rate of the first gas 109 entering the plasma generation region 106. In some embodiments, the gas pipeline 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 through the gas pipeline 130. In this way, due to the gas flow of the first gas ejected from the gas pipeline, the problem of solid products (such as carbon) accumulating on the outer surface of the inner electrode and / or on the inner surface of the outer electrode can be alleviated, and the downtime of the plasma device 801 can be further reduced. The gas flow of the first gas 109 can also take away the heat of the outer electrode 105 to cool the outer electrode 105, and can also cool the inner electrode 104. In this way, the service life of the outer electrode 105 and / or the inner electrode 104 can be extended.

[0080] Fig. 9 900 can be performed on a plasma device, such as the aforementioned plasma device 100, plasma device 200, plasma device 500, plasma device 701, and plasma device 801. In some embodiments, the inner electrode of the plasma device may include any or all of the aforementioned Figures 2 to 4 characteristics, properties and parameters.

[0081] Reference Fig. 9 and Figure 1A to Figure 1B , method 900 includes introducing a first gas 109 into the first cavity 119 through the 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 includes a hydrocarbon gas. In some embodiments, step 910 may include introducing the first gas 109 into the first cavity 119 from the gas container 108. In some embodiments, method 900 may include heating the first gas 109 before the first gas 109 is introduced into the first cavity 119. If applicable, the above Figures 1A to 8 All other statements regarding the plasma apparatus in are applicable here.

[0082] Reference Fig. 9 and Figure 1A to Figure 1B , the method 900 includes flowing the first gas 109 from the first cavity 119 through the through hole 118 to the plasma generation region 106, and rotating the inner electrode 104 around the first rotation axis 104c (step 920). As previously described, 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 extends through the wall 104a of the inner electrode 104. The first rotation axis 104c extends through the first cavity 119 of the inner electrode 104. For more reference Figure 2 , Figure 3A and Figure 3B In some embodiments, rotating the inner electrode 104 includes obtaining a rotational driving force from a gas 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. Figure 7 In some embodiments, rotating the inner electrode 104 includes providing a rotational driving force by a motor 129 coupled to the inner electrode 104 as described above. Figures 1A to 8 All other descriptions regarding the plasma device and the inner electrode in are applicable here.

[0083] Reference Fig. 9 and Figure 1A to Figure 1B, the method 900 includes generating a plasma in the plasma generation region 106 by applying a voltage between the inner electrode 104 and the outer electrode 105 (step 930). In some embodiments, generating the plasma includes generating the plasma from a portion of the first gas 109. In other words, the method can be performed without introducing an additional working gas (e.g., nitrogen, oxygen, argon, air). In this way, the dissociation efficiency and yield of the method can be increased, and the formation of undesirable byproducts by reaction with the additional working gas can be avoided. The plasma can be a cold plasma or a non-thermal plasma, and the plasma device can be maintained at a relatively low temperature. For example, the plasma can be generated under non-thermodynamic conditions, so that the effective electron temperature can reach about 1000 degrees Celsius (1000° C.) to about 2000 degrees Celsius (2000° C.) or higher, while the bulk gas temperature is maintained at about less than 500 degrees Celsius (500° C.). This can avoid the problem of forming undesirable byproducts with high molecular weight (such as higher hydrocarbons and polycyclic compounds) and reducing the purity of the generated products when using hot or thermal plasma (such as plasma with a total gas temperature of about 2000 degrees Celsius) to crack hydrocarbons.

[0084] Reference Fig. 9 and Figure 1A to Figure 1B , the method 900 includes cracking the first gas 109 using a plasma (step 940). As previously described, the plasma can crack the molecules of the first gas 109 and break their chemical bonds. In some embodiments, the cracking process occurs in the plasma generation region 106. In some embodiments, the method 900 may include outputting the products generated by cracking the first gas 109 from the outlet 116. In some embodiments, the products include a second gas 125 and a solid product 124. In the case where the first gas 109 includes hydrocarbons, the second gas 125 may include hydrogen, and the solid product 124 may include solid carbon. In some embodiments, a portion of the un-cracking first gas 109 and / or other impurities may be output from the outlet 116. In some embodiments, the second gas 125 may include a decarbonized hydrocarbon gas (e.g., a mixture of hydrogen and hydrocarbon gases).

[0085] Reference Fig. 9 and Figure 1A to Figure 1BIn some embodiments, the method 900 may further include separating the solid product 124 from the second gas 125 by the separation device 117 as described above. In the case where the first gas 109 includes hydrocarbons, the separation device 117 can separate the solid carbon from the hydrogen (or the decarbonized hydrocarbon gas). The solid carbon can be used as an industrial raw material such as carbon black. In addition, the production and separation of carbon black can be performed without the need for additional energy. The hydrogen or the decarbonized hydrocarbon gas can be used for low-carbon emission power generation. In some embodiments, the hydrogen can be stored in the form of liquid hydrogen, compressed hydrogen, or metal hydride.

[0086] Reference Fig. 9 and Figure 1A to Figure 1B In some embodiments, the method 900 may further include inputting the second gas 125 to the generator 110. Figure 1A As shown, the generator 110 can be coupled to the gas outlet 122 of the separation device 117. In this way, the second gas 125 (such as hydrogen or decarbonized hydrocarbon gas) passing through the separation device 117 can be discharged from the gas outlet 122 and input to the generator 110. In one embodiment, the generator 110 may include a fuel cell. In one embodiment, the generator 110 may include a turbine or an engine. In some embodiments, due to the airtight design of the insulating layer 103 and / or the bottom cover 111 as described above, the second gas 125 can be input to the generator 110 at a desired gas pressure (such as atmospheric pressure, or a higher pressure such as 100 bar) without passing through a pump or a compressor. The input pressure of the second gas 125 can be controlled, for example, by the inlet valve 101.

[0087] Reference Fig. 9 and Figure 1A to Figure 1B And refer to Figure 2 In some embodiments, the method 900 may further include cooling the inner electrode 104 by a gas flow of the first gas 109 as described above, the gas flow being from the first cavity 119 through the through hole 118 to the plasma generation region 106, and the related description is omitted for brevity. In some embodiments, the plasma device may be operated without an additional cooling system. If applicable, the above Figures 1A to 8 All other statements regarding the plasma apparatus in are applicable here.

[0088] Reference Fig. 9 and Figure 1A to Figure 1B And refer to FIG. 5A to FIG. 6In some embodiments, the method 900 may further include removing the solid product 124 attached to the inner electrode 104 by the scraping unit 123 as described above, and the related description is omitted for brevity. Figures 1A to 8 All other statements regarding the plasma apparatus in are applicable here.

[0089] Reference Fig. 9 and Figure 1A to Figure 1B And refer to Figure 8 In some embodiments, the method 900 may further include introducing the first gas 109 into the plasma generation region 106 through the gas pipeline 130 as described above, and the gas pipeline 130 is embedded in the wall 105a of the outer electrode 105, and the related description is omitted for brevity. If applicable, the above Figures 1A to 8 All other statements regarding the plasma apparatus in are applicable here.

[0090] The description of the above embodiments can be used by those with ordinary skills in the art to implement the subject matter. Various modifications to the embodiments are obvious to those with ordinary skills in the art, and the basic principles determined here can be applied to other embodiments without creative work. Therefore, the subject matter claimed is not limited to the embodiments shown here, but is to the widest range consistent with the principles and novel features disclosed herein. It is envisioned that other embodiments are also within the spirit and scope disclosed by the present invention. Therefore, the present invention is intended to cover modifications and changes within the scope of the attached patent claims and their equivalents.

Claims

1. A plasma device, comprising: an inner electrode including walls defining a first cavity, an opening of the first cavity being configured to receive a first gas, the inner electrode being rotatable about a first rotation axis, wherein the first rotation axis extends through the first cavity; as well as an outer electrode, the outer electrode surrounding the inner electrode; The inner electrode has a through hole extending through the wall of the inner electrode, so that the first cavity is in fluid communication with a plasma generation region through the through hole, the plasma generation region being located between the inner electrode and the outer electrode.

2. The plasma device of claim 1, wherein the inner electrode and the outer electrode are both substantially tubular. 3 . The plasma device according to claim 1 , wherein the outer electrode and the inner electrode are coaxially arranged. 4 . The plasma device of claim 1 , further comprising a rotating element mechanically coupled to the inner electrode such that the inner electrode is rotatable about the first rotation axis. 5 . The plasma device according to claim 4 , wherein the rotating element comprises a bearing or a rotor. 6 . The plasma apparatus of claim 1 , further comprising a motor coupled to the inner electrode, the motor being configured to provide a rotational driving force to rotate the inner electrode about the first rotation axis.

7. The plasma device according to claim 1, wherein the through hole is configured to obtain a rotational driving force from a gas flow of the first gas from the first cavity through the through hole to the plasma generation region, and the rotational driving force rotates the inner electrode around the first rotation axis.

8. The plasma device of claim 1, wherein in a cross section of the inner electrode, a first angle between an extension direction of the through hole and a radial direction of the through hole is between about 5 degrees and about 85 degrees, wherein the cross section is perpendicular to a longitudinal axis of the inner electrode.

9. The plasma device of claim 1 , wherein a second angle between an extension direction of the through hole and an axial direction is between about 5 degrees and about 85 degrees, wherein the axial direction coincides with a longitudinal axis of the inner electrode and extends from a point in the first cavity to the opening of the first cavity. 10 . The plasma apparatus of claim 1 , further comprising a gas inlet configured to enable the first gas to flow into the first cavity. 11 . The plasma apparatus of claim 10 , further comprising a gas container coupled to the gas inlet, wherein the gas container contains the first gas. 12 . The plasma device according to claim 1 , further comprising an insulating layer annularly disposed between the outer electrode and the inner electrode. 13 . The plasma apparatus of 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 of claim 1 , further comprising a scraping unit configured to contact an outer surface of the inner electrode and move relative to the outer surface of the inner electrode. 15 . The plasma apparatus of claim 14 , wherein the scraping unit surrounds the outer surface of the inner electrode and is configured to move in a first direction along a longitudinal axis of the inner electrode and in a second direction opposite to the first direction.

16. The plasma device according to claim 15, wherein the scraping unit comprises a first scraping blade, a second scraping blade, and a connecting member connecting the first scraping blade and the second scraping blade, wherein the first scraping blade is configured to contact the outer surface of the inner electrode and move relative to the outer surface of the inner electrode, and the second scraping blade is configured to contact the inner surface of the outer electrode and move relative to the inner surface of the outer electrode. 17 . The plasma device of claim 1 , further comprising an outlet configured to output a second gas and a solid product, the second gas and the solid product being generated from the first gas. 18 . The plasma device of claim 17 , further comprising a separation device connected to the outlet, the separation device being configured to separate the solid product from the second gas. 19 . The plasma apparatus according to claim 18 , wherein the separation device comprises a dust collector and a filter connected to the dust collector. 20 . The plasma device of claim 17 , further comprising a bottom cover connected to the outer electrode at one end of the outer electrode, wherein the outlet is provided at the bottom cover. 21 . The plasma apparatus of claim 1 , wherein the outer electrode comprises a gas conduit embedded in a wall of the outer electrode, and the gas conduit is configured to introduce the first gas into the plasma generation region.

22. The plasma apparatus of claim 1, wherein the first gas comprises a hydrocarbon gas.

23. A method comprising: introducing a first gas into the first cavity through an opening of the first cavity, the first cavity being defined by a wall of the inner electrode; flowing the first gas from the first cavity through a through hole extending through the wall of the inner electrode to a plasma generation region between the inner electrode and an outer electrode surrounding the inner electrode; generating plasma in the plasma generation region by applying a voltage between the inner electrode and the outer electrode; using the plasma to crack the first gas; and The inner electrode is rotated about a first rotation axis, wherein the first rotation axis extends through the first cavity.

24. The method of claim 23, wherein generating the plasma comprises generating the plasma from a portion of the first gas.

25. The method of claim 23, wherein the first gas comprises a hydrocarbon gas.

26. The method of claim 23, further comprising outputting a product from an outlet, the product produced by cracking the first gas.

27. The method of claim 26, wherein the products include a second gas and a solid product.

28. The method of claim 27, further comprising separating the solid product from the second gas by a separation device.

29. The method of claim 27, further comprising inputting the second gas to a generator.

30. The method of claim 23, wherein rotating the inner electrode comprises obtaining a rotational driving force from a flow of the first gas from the first cavity through the through hole to the plasma generation region.

31. The method of claim 23, wherein rotating the inner electrode comprises providing a rotational drive force by a motor coupled to the inner electrode.

32. The method of claim 23, further comprising removing a solid product attached to the inner electrode by a scraping unit.

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

34. The method of claim 23, wherein introducing the first gas comprises introducing the first gas into the first cavity from a gas container.

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

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

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