Gas reforming system

Abstract

A gas reforming system is proposed that serves as an environmental energy solution. More specifically, a gas reforming system utilizing plasma is proposed. The gas reforming system according to one embodiment may include a pre-treatment unit including a desulfurization module and a first gas separation module, a plasma reforming unit including a discharge tube, an RF generation unit, an antenna structure, and an additional reaction module, and a post-treatment unit including a gas conversion module and a second gas separation module.

Description

Technical Field

[0001] The present disclosure generally relates to a gas reforming system, and more specifically, to a system for reforming a feed gas by plasma to obtain a target gas.

Background Art

[0002] In recent years, due to the increasing concern about environmental problems, research on environmental energy solutions for reforming biogas or landfill gas into environmentally friendly energy has been actively carried out.

[0003] In particular, various studies have been conducted on gas reforming methods using catalysts, thermal energy, or plasma. Among these, inductively coupled plasma (ICP) technology offers multiple advantages over other methods. That is, it is more environmentally friendly, requires a relatively short processing time, and enables easier control of equipment.

[0004] However, conventional ICP-based gas reforming methods have not yet reached a level of energy conversion efficiency (ECE) sufficient to be commercially viable.

[0005] In the present disclosure, the aim is to introduce pre-treatment and post-treatment steps for reforming a feed gas into synthesis gas using ICP while interacting synergistically with plasma reforming. Through this approach, an efficient and environmentally friendly gas reforming system potentially suitable for practical and commercial applications is presented.

Summary of the Invention

Problems to be Solved by the Invention

[0006] Therefore, this disclosure has been made in consideration of the above-mentioned problems arising in the relevant art, and the object of this disclosure is to produce a synthesis gas having a specific composition ratio by modifying a feed gas with plasma.

[0007] The purpose of this disclosure is to design a pretreatment process, a plasma reforming unit, and a posttreatment process in order to provide a gas reforming system with high energy conversion efficiency.

[0008] The purpose of this disclosure is to design a pretreatment process such that the composition ratio of the reforming target gas supplied to the plasma reforming unit is a specific ratio.

[0009] The object of this disclosure is to provide a method for pre-activating a catalyst used in a gas conversion process during a post-processing step.

[0010] The purpose of this disclosure is to design a structure that controls the gas flow path within a plasma reforming unit.

[0011] The purposes of this disclosure are not limited to those mentioned above, and those skilled in the art will clearly understand from the following description and accompanying drawings that other purposes not mentioned above may be found. [Means for solving the problem]

[0012] To achieve the above objective, according to one aspect of the present disclosure, (1) a step of forming a first subfeed stream and a second subfeed stream by supplying a desulfurization feed gas to a first gas separation module, wherein the first separation module includes a porous separation membrane, wherein the first subfeed stream includes the feed gas that does not pass through the porous separation membrane, wherein the second subfeed stream includes the feed gas that passes through the porous separation membrane, wherein the molar ratio of carbon dioxide in the first subfeed stream is higher than the molar ratio of carbon dioxide in the second subfeed stream, wherein the molar ratio of methane in the first subfeed stream is lower than the molar ratio of methane in the second subfeed stream; (2) a step of forming a synthesis gas containing at least hydrogen and carbon monoxide by supplying the first subfeed stream, the second subfeed stream and steam (H2O) to a plasma reforming unit, wherein the first subfeed stream is configured to be supplied to the upstream end of a plasma induction region defined by a discharge tube of the plasma reforming unit, wherein the second subfeed stream and the steam (3) A step of forming an intermediate product by supplying the synthesis gas to a gas conversion module, wherein in the initial reduction section, the synthesis gas is configured to be supplied to the gas conversion module through a first path in the initial reduction section, and the supplied synthesis gas can be used as a reducing agent for the catalyst in the gas conversion module, wherein in the main reaction section, the synthesis gas is configured to be supplied to the gas conversion module through a second path, and the supplied synthesis gas can be converted to obtain the intermediate product, wherein the pressure of the synthesis gas supplied to the gas conversion module through the first path in the initial reduction section is lower than the pressure of the synthesis gas supplied to the gas conversion module through the second path in the main reaction section;A method for reforming a gas is provided, comprising the step of (4) supplying the intermediate product to a second gas separation module to form a final product.

[0013] The technical solutions of this disclosure are not limited to those mentioned above, and those skilled in the art will clearly understand from the following description and accompanying drawings other technical solutions not mentioned.

[0014] Favorable effects According to one embodiment, it is possible to provide a synthesis gas having the required composition ratio depending on the type of final product generated through the system.

[0015] According to one embodiment, it is possible to provide a gas reforming system having sufficient energy conversion efficiency to be commercially viable.

[0016] According to one embodiment, it is possible to achieve relatively low energy consumption during gas conversion in the post-processing step.

[0017] According to one embodiment, it is possible to improve the gas reaction rate and the durability of the components within the plasma reforming unit by controlling the gas flow within the plasma reforming unit.

[0018] The effects of this disclosure are not limited to those mentioned above, and those skilled in the art will clearly understand from the following description and accompanying drawings other effects not mentioned.

[0019] The above and other purposes, features, and other advantages of this disclosure will be better understood from the following detailed description when viewed in conjunction with the accompanying drawings. [Brief explanation of the drawing]

[0020] [Figure 1] This figure shows a gas reforming system according to one embodiment. [Figure 2]A diagram showing a pretreatment unit and a plasma reforming unit according to an embodiment. [Figure 3] A diagram showing a pretreatment gas separation module according to an embodiment. [Figure 4] A diagram showing the configuration of a plasma reforming unit according to an embodiment. [Figure 5] A diagram showing an RF generation unit according to an embodiment. [Figure 6] A diagram showing an antenna structure according to an embodiment. [Figure 7] A diagram showing a main antenna module according to an embodiment. [Figure 8] A diagram showing a main antenna module according to another embodiment. [Figure 9] A diagram showing the internal design of a plasma reforming unit according to an embodiment. [Figure 10] A flowchart showing a plasma reforming method according to an embodiment. [Figure 11] A diagram showing the process in which plasma reforming proceeds according to an embodiment. [Figure 12] A diagram showing the process in which plasma reforming proceeds according to an embodiment. [Figure 13] A diagram showing a discharge tube and a guide structure according to an embodiment. [Figure 14] A diagram showing a first gas supply nozzle and a second gas supply nozzle according to an embodiment. [Figure 15A] A diagram showing an additional reaction module according to an embodiment. [Figure 15B] A diagram showing the insulation structure of an additional reaction module according to an embodiment. [Figure 16] A diagram showing a plasma reforming unit and a post-treatment unit according to an embodiment. [Figure 17] A diagram showing a structure that enables syngas to flow into a gas conversion module according to an embodiment. [Figure 18] A diagram showing a gas conversion method according to an embodiment. [Figure 19]This figure shows the process of gas conversion according to one embodiment. [Figure 20] This figure shows the process of gas conversion according to one embodiment. [Figure 21] This figure shows the process of gas conversion according to one embodiment. [Modes for carrying out the invention]

[0021] In some embodiments, a method for reforming gas may be provided.The method is as follows: (1) to form a first subfeed stream and a second subfeed stream by supplying a desulfurization feed gas to a first gas separation module, wherein the first separation module includes a porous separation membrane, wherein the first subfeed stream includes the feed gas that does not pass through the porous separation membrane, wherein the second subfeed stream includes the feed gas that passes through the porous separation membrane, wherein the molar ratio of carbon dioxide in the first subfeed stream is higher than the molar ratio of carbon dioxide in the second subfeed stream, wherein the molar ratio of methane in the first subfeed stream is lower than the molar ratio of methane in the second subfeed stream; (2) to form a synthesis gas containing at least hydrogen and carbon monoxide by supplying the first subfeed stream, the second subfeed stream and vapor (H2O) to a plasma reforming unit, wherein the first subfeed stream is configured to be supplied to the upstream end of a plasma induction region defined by the discharge tube of the plasma reforming unit, wherein the second subfeed stream and the vapor are configured to be supplied to the downstream end of the plasma induction region, wherein (1) The first subfeed stream, the second subfeed stream, and the vapor are configured to be modified by plasma generated in the plasma induction region to form a synthesis gas; (2) The synthesis gas is supplied to a gas conversion module to form an intermediate product, wherein in the initial reduction section, the synthesis gas is configured to be supplied to the gas conversion module through a first path in the initial reduction section, and the supplied synthesis gas can be used as a reducing agent for a catalyst in the gas conversion module, wherein in the main reaction section, the synthesis gas is configured to be supplied to the gas conversion module through a second path, and the supplied synthesis gas can be converted to obtain the intermediate product, wherein the pressure of the synthesis gas supplied to the gas conversion module through the first path in the initial reduction section is lower than the pressure of the synthesis gas supplied to the gas conversion module through the second path in the main reaction section; and (3) The intermediate product is supplied to a second gas separation module to form a final product.

[0022] In some embodiments, the step of forming the synthesis gas includes generating the plasma by supplying a seed gas to the upstream end of the plasma induction region and supplying power to an auxiliary antenna module configured to surround at least a portion of the discharge tube; and maintaining the plasma discharge by supplying power to a main antenna module configured to surround at least a portion of the discharge tube.

[0023] In some embodiments, the seed gas is configured to be supplied to the plasma induction region from a first time point to a second time point, and the first subfeed flow is configured to be supplied to the plasma induction region from a third time point after the first time point to a fourth time point after the second time point. In some embodiments, the second time point at which the seed gas supply is stopped is after the time when power is supplied to the main antenna module. In some embodiments, the step of forming the synthesis gas includes controlling the flow rates of the first subfeed flow, the second subfeed flow, and the vapor flow rate so that the ratio of methane, carbon dioxide, and vapor supplied to the plasma induction region is within a predetermined range; the molar ratio of hydrogen to carbon monoxide (H2 / CO) in the synthesis gas is configured to be in the range of 1.8 to 2.7. In some embodiments, the direction in which the first subfeed flow is supplied to the plasma induction region and the direction in which the second subfeed flow is supplied to the plasma induction region are configured to be opposite to the central axis of the discharge tube. In some embodiments, the process further comprises a step of performing an additional reaction on the synthesis gas formed by plasma reforming using an additional reaction module configured to be located below the discharge tube, wherein the additional reaction module is configured to induce a catalytic reaction with the synthesis gas and increase the molar ratio of hydrogen in the synthesis gas. In some embodiments, the gas conversion module is a water-gas shift (WGS) module, and the molar ratio of carbon monoxide in the intermediate product is lower than the molar ratio of carbon monoxide in the synthesis gas. In some embodiments, the step of forming the intermediate product comprises cooling the synthesis gas transferred to the first path using a first heat exchanger module in the initial reduction section; and cooling and pressurizing the synthesis gas transferred to the second path using a second heat exchanger module and a compressor in the main reaction section.In some embodiments, the first heat exchanger is configured to cool the supplied gas to a first temperature range, and the second heat exchanger is configured to cool the supplied gas to a second temperature range, where the minimum value of the first temperature range is higher than the maximum value of the second temperature range. In some embodiments, a first valve is configured to control the flow of the synthesis gas to the first path, and a second valve is configured to control the flow of the synthesis gas to the second path. In some embodiments, the step of forming the synthesis gas includes inducing plasma into the plasma induction region by supplying power to the auxiliary antenna module and the main antenna module located adjacent to the discharge tube, and the opening time of the first valve is configured to be within a predetermined time from the time power is supplied to the main antenna module. In some embodiments, the closing time of the first valve is configured to occur after the temperature inside the gas conversion module has reached a predetermined temperature. In some embodiments, the opening time of the second valve is configured to occur after the temperature inside the gas conversion module has reached a predetermined temperature. In some embodiments, the closing time of the first valve is configured to be after the opening time of the second valve, so that the initial reduction section and the main reaction section overlap at least partially. In some embodiments, the step of forming the final product comprises adsorbing a specific gas from the intermediate product using an adsorbent in the second gas separation module.

[0024] The advantages and features of the disclosed embodiments and methods for achieving them can be more readily understood by referring to the following detailed descriptions of various embodiments and the accompanying drawings. Hereinafter, various embodiments of the disclosure will be referred to in detail, and specific examples thereof will be illustrated in the accompanying drawings and described below. However, the disclosure may be embodied in many different forms and should not be construed as being limited only to the embodiments described herein.

[0025] In the drawings, the thicknesses of layers and regions may be exaggerated for clarity. Furthermore, when an element or layer is referred to as being "on top of" or "above" another element or layer, it may also be directly on top of or above the other element or layer, or there may be elements or layers intervening between them. As a general rule, similar reference numerals designate similar elements throughout the specification. In addition, similar reference numerals are used to designate elements having the same function within the same concept illustrated in the drawings of each embodiment, and their redundant descriptions are omitted.

[0026] The numbers used in this specification (e.g., 1st, 2nd, etc.) are simply identifiers used to distinguish one element from another.

[0027] Furthermore, the suffixes “module” and “unit” used to refer to elements in the following embodiments are added or combined solely for the sake of ease of drafting the specification and do not have any distinct meaning or role in themselves.

[0028] In the following embodiments, the singular forms "a," "an," and "the" are intended to also include the plural forms unless the context explicitly indicates otherwise.

[0029] In the following embodiments, terms such as “comprise,” “include,” and “have” identify the presence of the described features and / or elements, but do not exclude the presence or addition of one or more other features and / or elements.

[0030] In the drawings, the size of elements may be exaggerated or reduced for illustrative purposes. For example, the size and thickness of elements in the drawings are arbitrarily shown for illustrative purposes, and embodiments of this disclosure are not limited thereto.

[0031] If some of the exemplary embodiments can be embodied in other ways, then certain processing steps described herein may be performed in other ways. That is, for example, the two processing steps described in a sequential order may be performed substantially simultaneously or in reverse order.

[0032] In the following embodiments, when films, regions, elements, etc. are referred to as being connected to one another, they may be directly connected, or one or more intervening films, regions, elements, etc. may be indirectly connected to one another through interposition between them.

[0033] For example, when it is mentioned that films, regions, elements, etc., are electrically connected to one another, they may be directly electrically connected to one another, such as being physically assembled or formed as a single unit to allow the flow of electric current, or one or more intervening films, regions, elements, etc., may be indirectly electrically connected to one another through interposition between them.

[0034] Furthermore, when films, regions, elements, etc. are referred to as being fluidly connected to one another, they may be directly fluidly connected to one another, such as being physically assembled or integrally formed to allow fluid flow, or one or more intervening films, regions, elements, etc. may be indirectly fluidly connected to one another through interposition between them. [introduction]

[0035] This disclosure relates in general to gas reforming systems, and more specifically to a system for reforming a feed gas with plasma to obtain a target gas.

[0036] Plasma is a phase in which matter receives high energy and separates into negatively charged electrons and positively charged ions, and it can be induced or generated by various methods.

[0037] Among the many methods for generating plasma, the inductively coupled plasma (ICP) method generates plasma by supplying power to a coil or antenna, thereby creating an induced or capacitive electric field in a specific space. This type of plasma is generally generated by a high-frequency power source such as radio frequency (RF). On the other hand, for the sake of explanation, plasma generated by plasma generation systems will be assumed to be inductively coupled plasma (ICP) and described below. However, the technical concepts of this disclosure are not limited to this.

[0038] Gas reforming refers to the process of converting an existing gas into a different type of gas, which may be carried out using various methods, such as catalyst-based reforming, thermal energy-based reforming, and plasma-based reforming. For the sake of explanation, gas reforming will be described below as a process in which a supplied gas is converted into a different type of gas using plasma. However, the technical concepts of this disclosure are not limited thereto.

[0039] Feed gas refers to the gas that is to be reformed. For example, feed gas may refer to the gas that is to be processed at a location where a gas reforming system is required. In another example, feed gas may refer to a predetermined amount of gas recovered using a specific method.

[0040] Depending on its source, feed gas may be classified as biogas, landfill gas (LFG), natural gas, or methane gas. Depending on its type, feed gas may contain methane (CH4), carbon dioxide (CO2), hydrogen (H2), oxygen (O2), nitrogen (N2), and similar substances. For the sake of explanation, the feed gas will be described below as containing at least methane and carbon dioxide. However, the technical concepts of this disclosure are not limited thereto.

[0041] The target gas may refer to the final product (or final product gas) intended to be produced through the gas reforming system. The target gas may include, but is not limited to, high-purity hydrogen, methanol, aviation fuel, base oil, bionaphtha, biodiesel, carbon black, graphene, carbon nanotubes, ammonia, or carbon monoxide.

[0042] [Gas reforming system] The gas reforming system will be described below with reference to Figure 1.

[0043] Figure 1 shows a gas reforming system 100 according to one embodiment.

[0044] Referring to Figure 1, the gas reforming system 100 may include a pre-treatment unit 1000, a plasma reforming unit 2000, and a post-treatment unit 3000.

[0045] The pretreatment unit 1000 is configured to perform pretreatment on the feed gas prior to gas reforming through the plasma reforming unit 2000. For example, the pretreatment unit 1000 may perform desulfurization and gas separation on the feed gas. Specific details of the processes performed in the pretreatment unit 1000 will be described later.

[0046] The plasma reforming unit 2000 is configured for reforming a gas using plasma. The plasma reforming unit 2000 may perform gas reforming by generating plasma through plasma induction, receiving a pre-treated feed gas, and passing it through the plasma region.

[0047] For example, when reforming a feed gas containing methane and carbon dioxide, the following reactions may occur in the plasma reforming unit 2000. CH4 + H2O → CO + 3H2 CO + H2O → CO2 + H2 CH4 + CO2 → 2CO + 2H2

[0048] The above reaction proceeds as the supplied gas is decomposed and recombined by the thermal energy of the plasma. As a result, methane and carbon dioxide in the feed gas are reformed by the plasma, producing a synthesis gas containing hydrogen and carbon monoxide.

[0049] Here, the ratio of hydrogen to carbon monoxide in the reformed synthesis gas may be determined according to the molar ratio of the gas supplied to the plasma reforming unit 2000.

[0050] In this case, the hydrogen-to-carbon monoxide ratio in the synthesis gas needs to be specified to a desirable value depending on the type of gas that will ultimately be produced. For example, if the final product is high-purity hydrogen, a higher hydrogen ratio in the synthesis gas is preferable. In another example, if the final product is methanol, the synthesis gas preferably has a hydrogen-to-carbon monoxide ratio (H2 / CO) of about 2.6 and / or an H2 / (2CO+3CO2) ratio of about 1.05. In yet another example, if the final product is aviation fuel, the synthesis gas preferably has a hydrogen-to-carbon monoxide ratio (H2 / CO) of about 1.8 to about 2.2 and a relatively low amount of vapor.

[0051] As described above, the molar ratio or flow rate of the gas supplied to the plasma reforming unit 2000 may be determined to adjust the hydrogen-to-carbon monoxide ratio in the synthesis gas, which varies depending on the type of final product. This will be explained in detail later.

[0052] The post-processing unit 3000 is configured to process the synthesis gas modified in the plasma modification unit 2000 in order to obtain the final product. For example, the post-processing unit 3000 may perform a gas conversion process to increase the purity of a specific gas in the synthesis gas and a gas separation process to separate the target gas.

[0053] Although not shown in Figure 1, the gas reforming system 100 may further include a central control unit for controlling the pretreatment unit 1000, the plasma reforming unit 2000, and the posttreatment unit 3000. The central control unit may control a first controller for controlling the pretreatment unit 1000, a second controller for controlling the plasma reforming unit 2000, and a third controller for controlling the posttreatment unit 3000.

[0054] In addition, although not shown in Figure 1, the gas reforming system 100 may further include a recovery unit for recovering the target gas or final product.

[0055] The pre-treatment unit 1000, the plasma modification unit 2000, and the post-treatment unit 3000 will be described in more detail below with reference to the drawings. [Pre-processing unit] 1. Structure of the pre-processing unit Figure 2 shows a pretreatment unit 1000 and a plasma modification unit 2000 according to one embodiment.

[0056] Referring to Figure 2, the pretreatment unit 1000 may include a desulfurization module 1100, a pretreatment gas separation module 1200, a first gas separation pipe 1210, and a second gas separation pipe 1220.

[0057] The desulfurization module 1100 may perform a desulfurization treatment on the feed gas. The desulfurization treatment may be understood as one of the treatments to remove unwanted components from the feed gas before it is injected into the plasma reforming unit 2000. Specifically, if the feed gas is biogas, it may contain components such as hydrogen sulfide, halides, and silicon-containing compounds. These components may form corrosive acids during the reforming process, which may reduce the durability of the plasma reforming unit 2000 or the post-treatment unit 3000, and therefore need to be removed from the feed gas.

[0058] The desulfurization module 1100 may receive a feed gas and remove hydrogen sulfide from it. The hydrogen sulfide removal process in the desulfurization module 1100 may be classified into dry, wet, and biological processes. For example, the desulfurization module 1100 may perform a dry desulfurization process that removes hydrogen sulfide by physical / chemical adsorption using adsorbents such as metal oxides of iron, zinc, and copper and activated carbon. In another example, the desulfurization module 1100 may perform a wet desulfurization process that dissolves hydrogen sulfide by bringing the feed gas into contact with a liquid at a specific temperature and pressure. In yet another example, the desulfurization module 1100 may perform a biological desulfurization process that removes hydrogen sulfide by oxidizing and decomposing it using the metabolic activity of microorganisms.

[0059] The desulfurization module 1100 may be fluidically connected to the pretreatment gas separation module 1200. Specifically, the outlet of the desulfurization module 1100 may be fluidically connected to the inlet of the pretreatment gas separation module 1200, thereby enabling the gas that has undergone desulfurization treatment in the desulfurization module 1100 to flow to the pretreatment gas separation module 1200.

[0060] The pretreatment unit 1000 may further include modules for removing specific components in addition to the desulfurization module 1100. For example, if the feed gas is landfill gas, the pretreatment unit 1000 may further include a dehumidification module for removing moisture.

[0061] The pre-treatment gas separation module 1200 may separate the supplied gas into a plurality of sub-feed streams. For example, the pre-treatment gas separation module 1200 may separate the supplied feed stream into a first sub-feed stream and a second sub-feed stream. The gas separation process performed by the pre-treatment gas separation module 1200 will be described later.

[0062] The pre-treatment gas separation module 1200 may be connected to a plurality of gas separation pipes. For example, the outlet of the pre-treatment gas separation module 1200 may be connected to a first gas separation pipe 1210 and a second gas separation pipe 1220. The first subfeed flow separated in the pre-treatment gas separation module 1200 may flow to the first gas separation pipe 1210, and the second subfeed flow may flow to the second gas separation pipe 1220.

[0063] The multiple gas separation pipes may be understood as a configuration that fluidly connects the pretreatment gas separation module 1200 and the plasma reforming unit 2000 to one another. Here, each of the multiple gas separation pipes functions to supply a gas having a specific composition ratio to a specific location within the plasma reforming unit 2000. For example, as described below, the first gas separation pipe 1210 is connected to an inlet located at the upper end of the plasma reforming unit 2000 and is configured to supply carbon dioxide-rich gas (CO2-rich gas) to the upstream end of the plasma induction region of the plasma reforming unit 2000. In addition, as also described below, the second gas separation pipe 1220 is connected to a second inlet located at the lower end of the plasma reforming unit 2000 and is configured to supply methane-rich gas (CH4-rich gas) to the downstream end of the plasma induction region of the plasma reforming unit 2000.

[0064] 2. Pre-treatment gas separation module The gas separation method performed in the pre-treatment gas separation module 1200 will be described below with reference to Figure 3. Figure 3 shows a pre-treatment gas separation module 1200 according to one embodiment.

[0065] Referring to Figure 3, the gas supplied to the pre-treatment gas separation module 1200 includes various types of gases. For example, the supplied gas may include carbon dioxide, hydrogen, oxygen, nitrogen, and methane.

[0066] On the other hand, one of the important aspects of plasma modification is plasma induction and maintenance.

[0067] This is because maintaining a stable plasma after induction ensures consistent gas reforming or decomposition.

[0068] At this time, depending on the type of gas supplied to the plasma modification unit 2000, the plasma discharge may be either stably maintained or hindered. For example, in the case of gases such as methane, which are involved in the endothermic reaction, this can be understood as a gas that hinders the maintenance of the plasma discharge because it absorbs thermal energy from the plasma. Therefore, in order to ensure the stability of the plasma discharge, it is necessary to control gases that hinder the plasma discharge, such as methane, among the gases injected into the plasma modification unit 2000.

[0069] In the gas reforming system 100 according to this disclosure, when gas is injected into the plasma reforming unit 2000, gases that hinder plasma maintenance, such as methane gas, may be separated. The separated gases may then be injected into the downstream end of the plasma induction region so as not to pass through the plasma. At this time, such plasma suppression gases may also be decomposed by heat from the plasma tail, thereby minimizing gas waste and ensuring a stable plasma discharge.

[0070] Referring again to Figure 3, the pretreatment gas separation module 1200 may include a separation membrane 1230. The separation membrane 1230 may have a porous structure. For example, the separation membrane 1230 may be understood as a membrane containing pores having a predetermined size range.

[0071] The separation membrane 1230 may be located between the inlet of the pre-treatment gas separation module 1200 and the first gas separation pipe 1210. The separation membrane 1230 may also be located between the inlet of the pre-treatment gas separation module 1200 and the second gas separation pipe 1220.

[0072] The separation membrane 1230 may separate gases having a predetermined particle size from the feed flow supplied to the pre-treatment gas separation module 1200. For example, when the feed flow is supplied to the pre-treatment gas separation module 1200, hydraulic pressure may be formed, and the resulting hydraulic pressure may become a force that causes a portion of the feed flow to permeate the separation membrane 1230.

[0073] Referring to Figure 3, when the feed flow contains carbon dioxide and methane, methane with relatively small particle sizes may permeate through the separation membrane 1230, while carbon dioxide with relatively large particle sizes may not permeate through the separation membrane 1230.

[0074] As a result, the feed stream supplied to the pre-treatment gas separation module 1200 may be separated into a first sub-feed stream with a high molar ratio of carbon dioxide and a second sub-feed stream with a high molar ratio of methane. For example, the molar ratio of carbon dioxide to methane in the first sub-feed stream may be about 10:0 to 7:3, and the molar ratio of carbon dioxide to methane in the second sub-feed stream may be about 0:10 to 2:8.

[0075] Here, the molar ratio of carbon dioxide in the first subfeed stream is greater than that of carbon dioxide in the second subfeed stream. In addition, the molar ratio of methane in the first subfeed stream is lower than that of methane in the second subfeed stream.

[0076] On the other hand, the molar ratio of carbon dioxide in the first subfeed stream and the molar ratio of methane in the second subfeed stream may vary depending on the design method of the pretreatment gas separation module 1200. For example, the molar ratio of carbon dioxide in the first subfeed stream and the molar ratio of methane in the second subfeed stream may be determined based on the pressure in the pretreatment gas separation module 1200 and the pore size of the separation membrane 1230.

[0077] As described above, i) in order to maintain the plasma discharge, it is necessary to inject gases involved in the endothermic reaction, such as methane, into the downstream end of the plasma induction region, and ii) in order to achieve a specific hydrogen-to-carbon monoxide ratio in the synthesis gas reformed in the plasma reforming unit 2000, as will be explained below, it is necessary to control the composition ratio of the gas introduced into the plasma reforming unit 2000 so that it falls within a predetermined range. From this perspective, the specifications of the separation membrane 1230 need to be appropriately selected to separate the feed stream supplied from the pretreatment gas separation module 1200 into a plurality of subfeed streams having the desired gas composition ratios.

[0078] For example, if the feed stream supplied to the pre-treatment gas separation module 1200 contains approximately 34% carbon dioxide, 44% methane, 20% nitrogen, and 2% oxygen, the separation membrane 1230 may separate the feed stream so that the first sub-feed stream contains approximately 60% carbon dioxide, 25% methane, 12% nitrogen, and 3% oxygen, and the second sub-feed stream contains approximately 10% carbon dioxide, 58% methane, 29% nitrogen, and 3% oxygen.

[0079] In the above description, the pre-treatment gas separation module 1200 was described as being implemented in a form including a separation membrane 1230, but the technical concepts of this disclosure are not limited thereto.

[0080] For example, if the feed gas to be reformed in the gas reforming system 100 contains a large amount of nitrogen (which is considered an inhibitor of the reforming efficiency in plasma reforming), the nitrogen may be difficult to separate using the separation membrane 1230. In this case, the pre-treatment gas separation module 1200 may instead be implemented using a pressure swing adsorption (PSA) method.

[0081] On the other hand, the pretreatment unit 1000 does not have to perform any additional special treatments other than the desulfurization and gas separation treatments described above. For example, the pretreatment unit 1000 does not have to perform a methane enrichment treatment to purify methane in the feed gas. As a result, most of the feed gas may flow to the plasma reforming unit 2000 for reforming. Since no portion of the feed gas is wasted, the energy conversion efficiency may be improved. Furthermore, since no additional treatment is required, the overall time required for gas reforming may be reduced, and the operating costs associated with additional treatments may be saved.

[0082] [Plasma Modification Unit] The plasma modification unit 2000 will be described below with reference to Figures 4 to 15. 1. Structure Figure 4 shows the configuration of a plasma modification unit 2000 according to one embodiment.

[0083] Referring to Figure 4, the plasma modification unit 2000 may include an RF generation unit 2100, an antenna structure 2200, a discharge tube 2300, a guide structure 2400, a seed gas supply module 2500, a steam supply module 2600, and an additional reaction module 2600.

[0084] First, the discharge tube 2300 defines a space in which plasma is induced and the supplied gas is subjected to plasma modification. In other words, the discharge tube 2300 includes an inner wall that defines the plasma induction region and may have various shapes, such as a cylindrical shape or a polygonal prism shape.

[0085] At least a portion of the discharge tube 2300 may be made of a heat-resistant material such as at least one of aluminum oxide, silicon nitride, silicon dioxide, yttrium oxide, ceramic, silicon carbide, and combinations thereof.

[0086] The antenna structure 2200 may be arranged around the discharge tube 2300. The antenna structure 2200 may function to generate an electromagnetic field within the discharge tube 2300 by receiving power. In this case, the component configured to supply power to the antenna structure 2200 is the RF generation unit 2100. The process by which the RF generation unit 2100 and the antenna structure 2200 induce plasma will be described later.

[0087] The RF generation unit 2100 may include multiple RF generators. For example, the RF generation unit 2100 may include the same number of RF generators as the number of antenna modules constituting the antenna structure 2200. Specifically, if the antenna structure 2200 includes an auxiliary antenna module and a main antenna module, the RF generation unit 2100 may include a first RF generator for supplying power to the auxiliary antenna module and a second RF generator for supplying power to the main antenna module. Even if the antenna structure 2200 includes multiple antenna modules, the RF generation unit 2100 may include a single RF generator, and power may be supplied to the multiple antenna modules using this single RF generator.

[0088] The seed gas supply module 2500 may supply seed gas into the discharge tube 2300. Here, the seed gas may be understood as a gas used to discharge plasma, such as argon or helium.

[0089] The steam supply module 2600 may supply steam into the discharge tube 2300. The steam supply module 2600 may be fluidically connected to the discharge tube 2300 and control the ratio of steam in the gas flow supplied into the discharge tube 2300 to within a predetermined range.

[0090] The guide structure 2400 may supply gas to the downstream end of the plasma induction region within the discharge tube 2300. For example, the guide structure 2400 may extend from the lower end of the discharge tube 2300 to the downstream end of the plasma induction region, thereby allowing the gas supplied to the lower end of the discharge tube 2300 to flow along the outer wall of the guide structure 2400 and reach the downstream end of the plasma induction region. The guide structure 2400 may be coupled to the discharge tube 2300. For this purpose, the discharge tube 2300 may be divided into a first part and a second part having different widths. The shape of the guide structure 2400 and the positional relationship between the discharge tube 2300 and the guide structure 2400 will be described later.

[0091] The additional reaction module 2700 may induce additional reactions in the gas produced through plasma reforming. For example, the additional reaction module 2700 may contain a catalyst and induce catalytic reactions in the gas supplied after passing through the plasma induction region. As a result, the additional reaction module 2700 may improve the reforming efficiency in the plasma reforming unit 2000.

[0092] The additional reaction module 2700 may be located at the lower end of the discharge tube 2300. Alternatively, the additional reaction module 2700 may be located between the discharge tube 2300 and the post-processing unit 3000 with respect to the gas flow path. The additional reaction module 2700 may be omitted. The configuration and design method of the additional reaction module 2700 will be described later.

[0093] 2. RF generation unit The RF generation unit 2100 will be described in detail below with reference to Figure 5. Figure 5 shows an RF generation unit 2100 according to one embodiment.

[0094] Referring to Figure 5, the RF generation unit 2100 may include an AC power supply 2110, a rectifier 2120, an inverter 2130, a sensor module 2140, and a control unit 2150. The RF generation unit 2100 may convert the first alternating current (AC) power supplied from the AC power supply 2110 into a second alternating current (AC) power and supply it to the load. For example, the RF generation unit 2100 may convert the first AC power, which is conventionally used in household or industrial applications, into a second AC power with a frequency in the range of several hundred kHz to several tens of MHz and a magnitude of several kW or more, and supply it to the load.

[0095] Here, the load may include the plasma generated by the antenna structure 2200 and the antenna structure 2200 itself. In this case, the load may exhibit a resonant frequency that changes over time due to the induced plasma.

[0096] The rectifier 2120 may convert the output of the AC power supply 2110 to direct current (DC). The rectifier 2120 may convert the first AC power supplied from the AC power supply 2110 to DC power and apply it to both terminals of the inverter 2130. On the other hand, in this disclosure, the term "DC power" may be interpreted as meaning either direct current or direct voltage.

[0097] The inverter 2130 may receive DC power from the rectifier 2120 and supply second AC power to the load. For example, the inverter 2130 may receive a switch signal from the control unit 2150 and use the received switch signal to supply second AC power to the load.

[0098] The inverter 2130 may include at least one switch element controlled by a switch signal, and the second AC power supplied from the inverter 2130 to the load may have a drive frequency set based on a switch signal received by the inverter 2130 from the control unit 2150.

[0099] For example, the inverter 2130 may be implemented in a full-bridge configuration. Specifically, the inverter 1300 may include first to fourth switches S1, S2, S3, and S4. Here, the first to fourth switches S1, S2, S3, and S4 may be turned on or off in response to switch signals received from the control unit 1500. In this case, when the first and third switches S1 and S3 are turned on and the second and fourth switches S2 and S4 are turned off, a positive voltage may be applied to the load. On the other hand, when the first and third switches S1 and S3 are turned off and the second and fourth switches S2 and S4 are turned on, a negative voltage may be applied to the load. In this way, the inverter 2130 may alternately apply positive and negative voltages to the load, thereby applying AC power having a specific frequency.

[0100] The implementation method of the inverter 2130 is not limited to those described above. For example, the inverter 2130 may refer to a configuration that includes a circuit structure that performs the function of converting DC power to AC power.

[0101] The inverter 2130 may be controlled, for example, by a time delay type, a pulse width modulation (PWM) type, or a combination thereof, depending on the frequency control method of the control unit 2150.

[0102] Alternatively, a capacitive element may be placed between the rectifier 2120 and the inverter 2130. For example, the RF generation unit 2100 may include a capacitor connected in parallel with the rectifier 2120 and the inverter 2130, and the capacitor may discharge the AC component of the power supplied to the inverter 2130 to the ground node GND.

[0103] The control unit 2150 may generate a switch signal. Specifically, the control unit 2150 may generate the switch signal by receiving data detected from the sensor module 2140, which will be described later. For example, the controller 2150 may be implemented to acquire data related to the resonant frequency, such as the load current and voltage, from the sensor module 2140 and generate a switch signal based on the acquired data. Specifically, the control unit 2150 may use the phase data of the current applied to the load and the phase data of the voltage applied to the load, acquired from the sensor module 2140, to acquire phase difference data or delay time, and generate a switch signal based on the phase delay data or delay time.

[0104] The control unit 2150 may be implemented as a central processing unit (CPU), microprocessor, processor core, multiprocessor, application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or similar, depending on the hardware, software, or a combination thereof.

[0105] The sensor module 2140 may provide the control unit 2150 with data related to the resonant frequency of the load or data related to the power supplied to the load.

[0106] Although not shown in Figure 5, the sensor module 2140 may also include a transformer, a filter, and a comparator.

[0107] The sensor module 2140 may receive a current or voltage signal flowing through the load, convert it into a current or voltage signal of different magnitudes using a current transformer, filter the converted current or voltage signal through a filter, and output phase data to the control unit 2150 via a comparator.

[0108] The current transformer may be inductively coupled to a wire between the inverter 2130 and the load, and may convert the voltage or current signal applied to the load and provide the converted voltage or current signal to the filter. Specifically, the current transformer may convert the current flowing through a conductive wire connected to the load into a voltage signal.

[0109] The filter may remove the DC component from the input current signal or voltage signal and output it to a comparator. To this end, the filter may perform high-pass band filtering or low-pass band filtering.

[0110] A comparator may acquire phase data. For example, a comparator may acquire phase data by comparing a voltage signal obtained from a current transformer or filter with a predetermined value. The phase data may refer to the phase data of the current applied to the load.

[0111] At least one of the components included in the sensor module 2140 may be omitted or implemented in another way.

[0112] As described above, the RF generation unit 2100 may control the drive frequency of the second AC power applied to the load based on data related to the load's resonant frequency. In other words, the RF generation unit 2100 may output the drive frequency of the second AC power to match the load's resonant frequency by tracking the load's resonant frequency, which shifts with changes in plasma conditions. This can prevent unnecessary power consumption and improve the durability of the plasma system.

[0113] On the other hand, although not shown in Figure 5, the RF generation unit 2100 may include memory. The memory may store various types of data. Various types of data may be stored in the memory temporarily or semi-permanently. Examples of memory may include hard disk drives (HDDs), solid state drives (SSDs), flash memory, read-only memory (ROMs), and random access memory. The memory may be implemented in a form that is built into the RF generation unit 2100 or in a removable form.

[0114] In addition, the RF generation unit 2100 may include an input unit for receiving user input. The input unit may receive user input from the user. User input may be implemented in various forms, including key input, touch input, and voice input. The input unit is a comprehensive concept that includes not only conventional keypads, keyboards, and mice, but also touch sensors that detect user touch, and various types of input devices that detect or receive various types of user input.

[0115] Furthermore, the RF generation unit 2100 may include an output unit for providing information to the user. The output unit may output information about the state of the plasma modification unit 2000 (e.g., sensor values ​​measured by the sensor module 2140, the drive frequency of the RF generation unit 2100, the temperature of the antenna structure 2200, and so on) and provide that information to the user. The output unit is a comprehensive concept that includes a display for outputting video, a speaker for outputting sound, a haptic device for generating vibrations, and various other types of output devices.

[0116] The RF generation unit 2100 described above may omit at least one of its components. For example, the RF generation unit 2100 may not include the sensor module 2140, and instead acquire electrical data related to the load from an external sensor. In another example, the RF generator unit 2100 may not include the AC power supply 2110 and the rectifier 2120, and instead receive DC power or rectified DC power from an external power supply.

[0117] 3. Antenna Structure The antenna structure 2200 will be described in detail below with reference to Figures 6 to 8. Figure 6 shows an antenna structure 2200 according to one embodiment.

[0118] Referring to Figure 6, the antenna structure 2200 may include an auxiliary antenna module 2210 and a main antenna module 2230. The auxiliary antenna module 2210 may be understood as an antenna module for plasma generation, and the main antenna module 2230 may be understood as an antenna module for maintaining the generated plasma. The processes for generating and maintaining the plasma will be described later.

[0119] The auxiliary antenna module 2210 may be arranged around the discharge tube 2300. The auxiliary antenna module 2210 may be mounted in a coil-like or ring shape surrounding the outer surface of the discharge tube 2300.

[0120] The auxiliary antenna module 2210 may have a layered structure. The auxiliary antenna module 2210 may have a structure in which identical or similar structures are stacked in the longitudinal direction of the discharge tube 2300. For example, as shown in Figure 6, the auxiliary antenna module 2210 may have a two-layer structure including two layer antennas. The number of layers in the auxiliary antenna module 2210 is not limited to two and may be appropriately determined as needed.

[0121] Each layer of the auxiliary antenna module 2210 may consist of multiple turns. For example, as shown in Figure 6, the auxiliary antenna module 2210 may consist of two turn antennas: an inner turn antenna surrounding the outer surface of the discharge tube 2300 and an outer turn antenna surrounding the inner turn antenna. The number of turns constituting each layer of the auxiliary antenna module 2210 is not limited to two and may be appropriately determined as needed.

[0122] The main antenna module 2230 may be arranged around the discharge tube 2300. The main antenna module 2230 may be mounted in a coil-like or ring shape surrounding the outer surface of the discharge tube 2300.

[0123] The main antenna module 2230 may have a layered structure. The main antenna module 2230 may have a structure in which identical or similar structures are stacked in the longitudinal direction of the discharge tube 2300. For example, as shown in Figure 6, the main antenna module 2230 may have a 7-layer structure. The number of layers in the main antenna module 2230 is not limited to 7 and may be appropriately determined as needed.

[0124] Each layer of the main antenna module 2230 may consist of multiple turns. For example, as shown in Figure 3, the main antenna module 2230 may consist of two turn antennas: an inner turn antenna surrounding the outer surface of the discharge tube 2300 and an outer turn antenna surrounding the inner turn antenna. The number of turns constituting each layer of the main antenna module 2230 is not limited to two and may be appropriately determined as needed.

[0125] The main antenna module 2230 may have at least one capacitive element. For example, the capacitive element may be electrically interposed between multiple antennas constituting the main antenna module 2230. Specifically, if the main antenna module 2230 includes multiple layer antennas and each layer antenna includes multiple turn antennas, the capacitive element may be electrically interposed between the multiple layer antennas and / or between the multiple turn antennas.

[0126] Here, the capacitive element may refer to an element having the function of storing electrical energy, such as a capacitor, ceramic capacitor, multilayer ceramic capacitor, or ultracapacitor, or its equivalent circuit.

[0127] Unlike the main antenna module 2230, the auxiliary antenna module 2210 does not need to include capacitive elements. This is because the inclusion of capacitive elements in an antenna module tends to reduce the voltage applied to both terminals of the antenna module, while, as will be explained below, a relatively high voltage needs to be applied to the auxiliary antenna module 2210 during plasma induction. It goes without saying that the auxiliary antenna module 2210 may include capacitive elements, and the main antenna module 2230 does not need to include capacitive elements.

[0128] The auxiliary antenna module 2210 and the main antenna module 2230 may be arranged around the discharge tube 2300 at a predetermined distance from each other. For example, as shown in Figure 6, the main antenna module 2230 may be separated from the auxiliary antenna module 2210 by a predetermined distance along the longitudinal direction of the discharge tube 2300.

[0129] On the other hand, the energy conversion efficiency (ECE) in the plasma reforming unit 2000 may vary depending on the shape of the main antenna module 2230. Here, ECE may refer to the extent to which the gas in the feed stream supplied to the plasma reforming unit 2000 is converted into synthesis gas through plasma reforming. Specifically, ECE may be obtained as the ratio of the energy of the gas converted in the plasma reforming unit 2000 to the energy of the gas injected into the plasma reforming unit 2000. On the other hand, when calculating ECE, the amount of electrical energy used in the plasma reforming unit 2000 may also be taken into consideration.

[0130] The shape of the main antenna module 2230 for increasing ECE will be described below with reference to Figures 7 and 8.

[0131] Figure 7 shows the main antenna module 2230 according to the first embodiment.

[0132] Referring to Figure 7, the main antenna module 2230 may be composed of multiple antenna segments. For example, the main antenna module 2230 may include first to third inner antenna segments 2231, 2233, and 2235 that form an inner turn, and first to third outer antenna segments 2232, 2234, and 2236 that form an outer turn.

[0133] The first inner antenna segment 2231 may be electrically connected to the first outer antenna segment 2232. The other end 2231b of the first inner antenna segment may be electrically connected to one end 2232a of the first outer antenna segment. The other end 2231b of the first inner antenna segment may be electrically connected to one end 2232a of the first outer antenna segment via a first connector. Here, the first connector may, but is not limited to, a U-shaped wire or coil.

[0134] On the other hand, one end 2231a of the first inner antenna may be electrically connected to one end of the RF generation unit 2100. In this case, the first auxiliary capacitive element SC1 may be electrically interposed between one end 2231a of the first inner antenna segment and the RF generation unit 2100.

[0135] The first outer antenna segment 2232 may be electrically connected to the second inner antenna segment 2233. The other end 2232b of the first outer antenna segment may be electrically connected to one end 2233a of the second inner antenna segment. The other end 2232b of the first outer antenna segment may be connected to one end 2233a of the second inner antenna segment via the first inter-turn capacitance element ITC1.

[0136] The second inner antenna segment 2233 may be electrically connected to the second outer antenna segment 2234. The other end 2233b of the second inner antenna segment may be electrically connected to one end 2234a of the second outer antenna segment. The other end 2233b of the second inner antenna segment may be electrically connected to one end 2234a of the second outer antenna segment via a second connector. Here, the second connector may, but is not limited to, a U-shaped wire or coil.

[0137] The second outer antenna segment 2234 may be electrically connected to the third inner antenna segment 2235. The other end 2234b of the second outer antenna segment may be electrically connected to one end 2235a of the third inner antenna segment. The other end 2234b of the second outer antenna segment may be connected to one end 2235a of the third inner antenna segment 2235 via the second inter-turn capacitance element ITC2.

[0138] The third inner antenna segment 2235 may be electrically connected to the third outer antenna segment 2236. The other end 2235b of the third inner antenna segment may be electrically connected to one end 2236a of the third outer antenna segment. The other end 2235b of the third inner antenna segment 2235 may be electrically connected to one end 2236a of the third outer antenna segment 2236 via a third connector. Here, the third connector may, but is not limited to, a U-shaped wire or coil.

[0139] On the other hand, the other end 2236b of the third outer antenna segment may be electrically connected to an antenna segment of another layer. However, if the main antenna module 2230 consists of a single layer, the other end 2236b of the third outer antenna segment may be electrically connected to the other end of the RF generation unit 2100. In this case, the second auxiliary capacitance element SC2 may be electrically interposed between the other end 2236b of the third outer antenna segment 2236 and the RF generation unit 2100. However, either the first auxiliary capacitance element SC1 or the second auxiliary capacitance element SC2 may be omitted.

[0140] As described above, if the antenna segments within the main antenna module 2230 are connected, they may be connected in series to the RF generating unit 2100 in the following order: first inner antenna segment 2231, first outer antenna segment 2232, first inter-turn capacitance element ITC1, second inner antenna segment 2233, second outer antenna segment 2234, second inter-turn capacitance element ITC2, third inner antenna segment 2235, and third outer antenna segment 2236.

[0141] Here, the first outer antenna segment 2232 and the first inter-turn capacitance element ITC1 may be electrically interposed between the first inner antenna segment 2231 and the second inner antenna segment 2233.

[0142] Furthermore, the second outer antenna segment 2234 and the second inter-turn capacitance element ITC2 may be electrically interposed between the second inner antenna segment 2233 and the third inner antenna segment 2235.

[0143] In addition, the second inter-turn capacitance element ITC2 and the third inner antenna segment 2235 may be electrically interposed between the second outer antenna segment 2234 and the third outer antenna segment 2236.

[0144] The portion shown in Figure 7 represents a single-layer antenna. The main antenna module 2230 may consist of multiple layers of antennas, each of which may be implemented as shown in Figure 7. In this case, the third outer antenna segment of the first-layer antenna may be electrically connected to the first inner antenna segment of the second-layer antenna, which is the next layer following the first-layer antenna, and an interlayer capacitor may be electrically interposed between them.

[0145] Figure 8 shows the main antenna module 2230 according to the second embodiment.

[0146] Referring to Figure 8, the main antenna module 2230 may be composed of multiple antenna segments. For example, the main antenna module 2230 may include a first inner antenna segment 2231 and a second inner antenna segment 2233 that form an inner turn, and a first outer antenna segment 2232 and a second outer antenna segment 2234 that form an outer turn.

[0147] The first inner antenna segment 2231 may be electrically connected to the first outer antenna segment 2232, and the second inner antenna segment 2233 may be electrically connected to the second outer antenna segment 2234. The methods by which the first inner antenna segment 2231 is connected to the first outer antenna segment 2232 and the methods by which the second inner antenna segment 2233 is connected to the second outer antenna segment 2234 are the same as those described in Figure 7 and are therefore omitted.

[0148] On the other hand, the other end 2232b of the first outer antenna segment 2232 may be connected to the first inner antenna segment of another layer antenna, or to the RF generation unit 2100 if the main antenna module 2230 is composed of a single layer. Similarly, the other end 2234b of the second outer antenna segment 2234 may be connected to the second inner antenna segment of another layer antenna, or to the RF generation unit 2100 if the main antenna module 2230 is composed of a single layer. In this case, an interlayer capacitor may be electrically interposed between the antenna segments of different layer antennas.

[0149] In other words, in the main antenna module 2230 according to the second embodiment, the first inner antenna segment and the first outer antenna segment of each layer may be connected in series with each other to form one closed circuit together with the RF generation unit 2100, and the second inner antenna segment and the second outer antenna segment of each layer may be connected in series with each other to form another closed circuit together with the RF generation unit 2100.

[0150] 4. Plasma modification method The plasma modification method will be explained below with reference to Figures 9 to 12. Before explaining the plasma modification method, we will first describe the internal design of the plasma modification unit 2000 used for modification.

[0151] Figure 9 shows the internal design of a plasma modification unit 2000 according to one embodiment.

[0152] First, the antenna structure 2200 may be arranged to surround the discharge tube 2300. In this case, the region within the discharge tube 2300 corresponding to the portion surrounded by the antenna structure 2200 may be understood as a plasma induction region (PIR).

[0153] As described above, the antenna structure 2200 may be electrically connected to the RF generation unit 2100. The RF generation unit 2100 may include a first RF generator 2100-1 corresponding to the auxiliary antenna module 2210 of the antenna structure 2200 and a second RF generator 2100-2 corresponding to the main antenna module 2230 of the antenna structure 2200.

[0154] Specifically, the auxiliary antenna module 2210 may be electrically connected to the first RF generator 2100-1. One end of the auxiliary antenna module 2210 may be electrically connected to one end of the first RF generator 2100-1, and the other end of the auxiliary antenna module 2210 may be electrically connected to the other end of the first RF generator 2100-1.

[0155] Furthermore, the main antenna module 2230 may be electrically connected to the second RF generator 2100-2. One end of the main antenna module 2230 may be electrically connected to one end of the second RF generator 2100-2, and the other end of the main antenna module 2230 may be electrically connected to the other end of the second RF generator 2100-2. In this case, a capacitive element may be electrically interposed between one end of the main antenna module 2230 and one end of the second RF generator 2100-2, and / or between the other end of the main antenna module 2230 and the other end of the second RF generator 2100-2.

[0156] Furthermore, the DC pulse power supply and DC electrodes may be placed outside the discharge tube 2300. The DC electrodes may receive a pulse voltage from the DC pulse power supply and generate a strong electric field inside the discharge tube 2300. The DC pulse power supply and DC electrodes may be used for plasma generation, as described below.

[0157] The discharge tube 2300 may be provided with an inlet for supplying feed flow. Multiple inlets may be formed in the discharge tube 2300.

[0158] For example, the discharge tube 2300 may include a first inlet 2310 and a second inlet 2320. The plasma induction region (PIR) may be located between the first inlet 2310 and the second inlet 2320. Specifically, the first inlet 2310 may be positioned at the upstream end of the plasma induction region PIR, and the second inlet 2320 may be positioned at the downstream end of the plasma induction region PIR.

[0159] At this time, the first inlet 2310 may be fluidically connected to the first gas separation pipe 1210 and the seed gas supply module 2500 of the pretreatment unit 1000. In other words, the first subfeed flow flowing through the first gas separation pipe 1210 and the seed gas supplied from the seed gas supply module 2500 may flow into the plasma induction region PIR through the first inlet 2310. Figure 9 shows that the seed gas and the first subfeed flow to the first inlet 2310 through separate pipes, but the technical concepts of this disclosure are not limited thereto. For example, the seed gas and the first subfeed flow may flow to the first inlet 2310 through the same pipe.

[0160] A swirl generator may be placed at the first inlet 2310 to cause the gas supplied to the discharge tube 2300 to form a swirl. The swirl generator may rotate the supplied gas clockwise or counterclockwise before supplying it to the discharge tube 2300.

[0161] Furthermore, the second inlet 2310 may be fluidically connected to the second gas separation pipe 1220 and the steam supply module 2600 of the pretreatment unit 1000. In other words, the second subfeed flow flowing through the second gas separation pipe 1220 and the steam supplied from the steam supply module 2600 may flow into the plasma induction region (PIR) via the second inlet 2320. Figure 9 shows that the second subfeed flow and steam are supplied via separate pipes, but the technical concepts of this disclosure are not limited thereto. For example, the second subfeed flow and steam may flow to the second inlet 2320 via the same pipe.

[0162] Alternatively, the flow rates of the first subfeed flow and seed gas introduced into the first inlet 2310 may be controlled. For example, a flow sensor may be installed at any point along the pipe through which the first subfeed flow and seed gas flow, and the flow rates of the first subfeed flow and seed gas may be controlled based on the detected flow rates. A mass flow controller (MFC) may also be used for flow rate control.

[0163] Similarly, the flow rates of the second subfeed flow and steam introduced into the second inlet 2320 may also be controlled.

[0164] The plasma modification method will be explained below with reference to Figures 10 to 12.

[0165] Figure 10 is a flowchart showing a plasma modification method according to one embodiment.

[0166] Figures 11 and 12 show the process of plasma modification according to one embodiment.

[0167] Referring to Figure 10, the plasma modification method may include the steps of: supplying a seed gas (S1100); applying power to the DC electrode and auxiliary antenna module 2210 (S1200); applying power to the main antenna module 2230 (S1300); supplying the target gas to be modified (S1400); stopping the supply of seed gas or changing the supplied seed gas (S1500); and controlling the flow rate of the supplied gas (S1600).

[0168] Each step is explained below.

[0169] Seed gas may be supplied to the discharge tube 2300 (S1100), and power may be applied to the DC electrode and auxiliary antenna module 2210 (S1200). Plasma generation processing may be performed through steps S1100 and S1200.

[0170] Referring to Figure 11, in the plasma generation process, seed gas is introduced into the discharge tube 2300, and when a DC pulse is applied to the DC electrode, a high voltage is applied inside the discharge tube 2300, ionizing the seed gas and increasing the electron density. When a voltage is applied to the auxiliary antenna module 2210 by the first RF generator 2100-1, an electric field E1 is formed. Therefore, the introduced seed gas is then accelerated by the electric field E1 and undergoes a phase transition to a plasma state. In the plasma generation process, as the electron density increases, the plasma transitions from the E mode, where capacitive coupling is dominant, to the H mode, where inductive coupling is dominant.

[0171] Next, power may be applied to the main antenna module 2230 (S1300). Step S1300 may be understood as a process for maintaining the generated plasma.

[0172] Referring to Figure 12, when a voltage is applied to the main antenna module 2230 by the second RF generator 2100-2, a continuously changing magnetic field is generated, inducing an electric field E2 within the discharge tube 2300. Then, particles in the H-mode plasma state move continuously under the influence of the induced electric field E2, thereby enabling the plasma to be maintained stably. At this time, the plasma may move in the plasma induction region (PIR) from the region corresponding to the auxiliary antenna module 2210 to the region corresponding to the main antenna module 2230.

[0173] As the plasma maintenance process progresses, a modified target gas may be supplied (S1500).

[0174] The target gas to be reformed may include the first subfeed flow, the second subfeed flow, and steam. The first subfeed flow, the second subfeed flow, and steam may be supplied simultaneously or sequentially. For example, steam may be supplied first, followed by the first subfeed flow at a flow rate of 1-1 and the second subfeed flow at a flow rate of 2-1. Subsequently, the first subfeed flow may be supplied at a flow rate of 1-2, which is greater than the flow rate of 1-1, and the second subfeed flow may be supplied at a flow rate of 2-2, which is greater than the flow rate of 2-1 (where the flow rate of 1-2 may represent the maximum flow rate at which the first subfeed flow can be supplied, and the flow rate of 2-2 may represent the maximum flow rate at which the second subfeed flow can be supplied). In another example, the first subfeed flow may be supplied first, followed by the second subfeed flow and steam simultaneously. In yet another example, the first subfeed flow, the second subfeed flow, and steam may be supplied simultaneously. In yet another example, the first and second subfeed flows may be supplied simultaneously, and the steam may be supplied afterward. In yet another example, the steam may be supplied first as a gas to maintain the plasma discharge, and then the first and second subfeed flows may be supplied afterward.

[0175] The supply or interruption of the first subfeed flow may be performed by opening and closing a valve installed at any point along the pipe through which the first subfeed flow flows, and by a mass flow controller. The supply or interruption of the second subfeed flow may be performed by opening and closing a valve installed at any point along the pipe through which the second subfeed flow flows, and by a mass flow controller. The supply or interruption of steam may be performed by opening and closing a valve installed at any point along the pipe through which the steam flows, and by a mass flow controller.

[0176] On the other hand, the feed flow introduced through the first inlet 2310 and the feed flow introduced through the second inlet 2320 may have opposite vortex directions. For example, if the vortex direction of the first sub-feed flow introduced through the first inlet 2310 is counterclockwise (or clockwise) with respect to the central axis of the discharge tube 2300, the vortex direction of the second sub-feed flow introduced through the second inlet 2320 may be clockwise (or counterclockwise). In the case of steam, it may be supplied in either the same vortex direction as that of the second sub-feed flow or in the opposite vortex direction. Therefore, if the vortex directions of the gas supplied through the first inlet 2310 and the second inlet 2320 are different, they may collide with each other and create turbulence, which may increase the gas reaction rate.

[0177] The supply of seed gas may be stopped, or the supplied seed gas may be changed (S1400). This is because seed gases such as argon have properties that make them difficult to separate when mixed with synthesis gas, and therefore, seed gas should preferably not be supplied during synthesis gas production. In other words, argon does not need to be supplied during synthesis gas production. Alternatively, a seed gas that is easily separated from synthesis gas or does not require separation (e.g., hydrogen gas) may be used as seed gas during synthesis gas production. Alternatively, a gas that is reformed into synthesis gas (e.g., methane or carbon dioxide) may be used as seed gas during synthesis gas production.

[0178] The supply or interruption of seed gas may be performed by opening and closing valves installed at any point along the pipe through which the seed gas flows, and by a mass flow controller.

[0179] The seed gas supply is stopped (or the seed gas is replaced from argon to another gas) at either the point when the voltage measured in the sub-antenna module 2210 exceeds a critical range (this critical range corresponds to the criteria for plasma generation and maintenance) or when a predetermined time has elapsed thereafter.

[0180] The target gas to be reformed may be supplied from a predetermined point in time prior to the point in time when the seed gas supply is stopped. More specifically, the flow rate of the seed gas may begin to decrease at the point in time when the target gas to be reformed is supplied or after a predetermined time thereafter. Here, the predetermined time may refer to the time required for the plasma to reach a steady state. In another example, the target gas to be reformed may be supplied at the point in time when the seed gas supply is stopped. In yet another example, the target gas to be reformed may be supplied from a predetermined point in time after the point in time when the seed gas supply is stopped.

[0181] The seed gas supply may be gradually reduced before it is stopped. For example, the seed gas flow rate may be gradually reduced by a predetermined amount from a predetermined point in time after power is applied to the main antenna module 2230, from the point in time when the target gas to be modified is supplied, or from a predetermined point in time thereafter. More specifically, the seed gas flow rate may be reduced by a first amount at a first point in time after the target gas to be modified is supplied, and further reduced by a second amount at a second point in time after the first point in time. In this case, it may be determined after the first point in time whether the plasma maintenance conditions are met. The plasma maintenance conditions may refer to the conditions under which the power consumption of the plasma load is maintained. If it is determined that the plasma maintenance conditions are met, the seed gas flow rate may be reduced by a second amount at the second point in time, and the determination of whether the plasma maintenance conditions are met may be performed again after the second point in time. On the other hand, the seed gas flow rate may be reduced by a second amount after a predetermined time has elapsed following the first point in time, regardless of whether the plasma maintenance conditions are met or not.

[0182] The timing at which the seed gas supply is stopped may vary depending on the type of final product. For example, if the final product is high-purity hydrogen and the synthesis gas contains a seed gas such as argon, separating the hydrogen and argon gases in the synthesis gas in the post-processing unit 3000 is relatively difficult. Therefore, it is necessary to prevent the seed gas from being included in the synthesis gas. Accordingly, if the final product is high-purity hydrogen, the seed gas supply may be stopped before the target gas to be reformed is supplied. Alternatively, the seed gas supply may be stopped after the target gas to be reformed has been supplied, but the reformed gas does not need to be supplied to the post-processing unit 3000 until the seed gas supply is stopped, and may instead be released to the outside.

[0183] During the plasma modification process (S1600), the flow rate of the supplied gas may be controlled.

[0184] The structure and configuration of the post-treatment unit 3000 may vary depending on the type of final product obtained through the gas reforming system 100. The gas composition ratio in the synthesis gas supplied to the post-treatment unit 3000 may be determined differently depending on the post-treatment unit 3000. For example, if the final product is high-purity hydrogen, a higher hydrogen ratio in the synthesis gas is preferable, regardless of the post-treatment unit 3000. As another example, if the final product is methanol, the post-treatment unit 3000 may include a configuration that promotes the hydrogenation of carbon dioxide or carbon monoxide, and the gas composition ratio in the synthesis gas supplied to the post-treatment unit 3000 is preferably such that the hydrogen-to-carbon monoxide ratio (H2 / CO) is about 2.6 and / or preferably the H2 / (2CO+3CO2) ratio is about 1.05. In yet another example, if the final product is aviation fuel, the post-processing unit 3000 may perform Fischer-Tropsch (FT) processing, and the synthesis gas supplied to the post-processing unit 3000 may preferably have a hydrogen-to-carbon monoxide ratio (H2 / CO) of about 1.8 to about 2.2 and a relatively low amount of vapor.

[0185] In other words, the composition ratio of the synthesis gas produced through plasma reforming needs to be controlled within a specific range, taking into account the post-processing steps. For this purpose, the ratio of gases supplied to the plasma induction region (PIR) may be adjusted. Specifically, the flow rates of the first subfeed flow, the second subfeed flow, and the vapor supplied to the plasma induction region (PIR) may be controlled.

[0186] For example, if the final product is high-purity hydrogen, the gas composition ratio inside the discharge tube 2300 must be controlled to satisfy the composition ratio condition of methane:carbon dioxide:vapor = approximately 1:0.5:2 as strictly as possible.

[0187] In another example, if the final product is methanol, the gas composition ratio inside the discharge tube 2300 must be controlled to satisfy the composition ratio condition of methane:carbon dioxide:vapor = approximately 1:0.35:1.6 as strictly as possible.

[0188] In yet another example, if the final product is synthetic crude oil (or aviation fuel), the gas composition ratio inside the discharge tube 2300 must be controlled to satisfy, as strictly as possible, the composition ratio condition of methane:carbon dioxide:steam = approximately 1:0.7:1.5.

[0189] The central control unit of the gas reforming system 100 or the controller of the plasma reformer 2000 may control the flow rates of the first subfeed flow, the second subfeed flow, and the steam based on sensor values ​​obtained by measuring the gas flow rate, so that the gas composition ratio in the discharge tube 2300 satisfies the above composition ratio conditions.

[0190] As described above, the gas flow rate may be controlled by the central control unit of the gas reforming system 100 or the controller of the plasma reforming unit 2000. In this case, sensors that detect the gas composition ratio or specific gas component ratio in the first subfeed flow and the second subfeed flow may be used. Specifically, a first gas sensor that measures the concentration of at least one of carbon dioxide and methane may be installed at any point along the pipe through which the first subfeed flow flows (e.g., the first gas separation pipe 1210). Similarly, a second gas sensor that measures the concentration of at least one of carbon dioxide and methane may be installed at any point along the pipe through which the second subfeed flow flows (e.g., the second gas separation pipe 1220). Furthermore, a third gas sensor that measures the concentration of steam may be installed at any point along the pipe through which steam flows. The central control unit or the controller of the plasma reforming unit 2000 may change the flow rate of at least one of the first subfeed flow, the second subfeed flow, and the steam by utilizing at least one of the first gas sensor, the second gas sensor, and the third gas sensor.

[0191] The synthesis gas generated through reforming in the plasma induction region (PIR) of the discharge tube 2300 may flow to the bottom of the discharge tube 2300. The synthesis gas that flows to the bottom of the discharge tube 2300 may undergo additional reactions in the additional reaction module 2700, as described below.

[0192] The structure for supplying gas below the plasma induction region (PIR) of the discharge tube 2300 will be described below with reference to Figure 13.

[0193] Figure 13 shows a discharge tube 2300 and a guide structure 2400 according to one embodiment.

[0194] Referring to Figure 13, the discharge tube 2300 and the guide structure 2400 may be configured to be connected to each other. For example, the discharge tube 2300 may be divided into a first part P1 and a second part P2, and the guide structure 2400 may be inserted into the second part P2 of the discharge tube 2300.

[0195] The first portion P1 of the discharge tube 2300 may be understood as the portion that defines the space in which the plasma is induced. Furthermore, the first portion P1 may be understood as the portion in which the antenna structure 2200 is located. Furthermore, the first portion P1 may be understood as the portion that defines the plasma induction region PIR.

[0196] The first part P1 may include the first entrance 2310 described above.

[0197] The first part P1 may be connected to the first gas separation pipe 1210.

[0198] The second portion P2 of the discharge tube 2300 may be understood as the portion that defines the space behind the downstream end of the plasma induction region PIR. Furthermore, the second portion P2 may be understood as the portion that defines the space into which the guide structure 2400 is inserted.

[0199] The second part P2 may include the second entrance 2320 described above.

[0200] The second section P2 may be connected to the second gas separation pipe 1220. Specifically, the gas supplied from the second gas separation pipe 1220 may flow into the second section P2 or into the first section P1 via the second section P2.

[0201] On the other hand, the antenna structure 2200 may be placed only around the first part P1 of the discharge tube 2300, and not around the second part P2 of the discharge tube 2300.

[0202] Alternatively, part of the antenna structure 2200 may be arranged around the first part P1 of the discharge tube 2300, and another part may be arranged around the second part P2 of the discharge tube 2300. In this case, more than half of the total number of layer antennas included in the antenna structure 2200 may be arranged around the first part P1 of the discharge tube 2300. Alternatively, 80% or more of the total number of layer antennas included in the antenna structure 2200 may be arranged around the first part P1 of the discharge tube 2300.

[0203] The first portion P1 of the discharge tube 2300 may have a first width W1 (or first diameter, first span). The second portion P2 of the discharge tube 2300 may have a second width W2 (or second diameter, second span). The first width W1 of the first portion P1 may be smaller than the second width W2 of the second portion P2. This is to prevent a reduction in the size of the flow path for synthesis gas caused by the insertion of the guide structure 2400 into the second portion P2.

[0204] The guide structure 2400 may include an inner wall, an outer wall, and at least one hole 2410 formed through the inner and outer walls. As described below, the gas supplied to the discharge tube 2300 may flow along the outer wall of the guide structure 2400. The gas that has flowed along the outer wall of the guide structure 2400 may flow into the guide structure 2400 through the hole 2410.

[0205] The guide structure 2400 may be inserted into the second portion P2 of the discharge tube 2300. When the guide structure 2400 is inserted into the second portion P2, a gap may be formed between the guide structure 2400 and the second portion P2. Specifically, a gap may be formed between the outer wall of the guide structure 2400 and the inner wall of the second portion P2, and the second subfeed flow and gases such as steam may flow through the formed gap.

[0206] Gas flowing through the gap formed between the guide structure 2400 and the second portion P2 of the discharge tube 2300 may flow into the guide structure 2400 or the discharge tube 2300 through the hole 2410. In this case, the hole 2410 may be located closer to the upper end of the guide structure 2400 than to the lower end. This is because, when the guide structure 2400 is coupled to the second portion P2, the upper end of the guide structure 2400 is positioned closer to the plasma induction region PIR or the first portion P1 than to the lower end, so that the guide structure 2400 is configured to supply gas to the plasma induction region PIR.

[0207] The guide structure 2400 may be designed to have a third width W3 (or a third diameter, a third span) and a predetermined thickness T. In this case, the third width W3 may be designed to satisfy a first design condition that it is equal to the first width W1 of the first portion P1 of the discharge tube 2300. In addition, the thickness T of the guide structure 2400 may be designed to satisfy a second design condition that it is less than half the difference between the first width W1 of the first portion P1 of the discharge tube 2300 and the second width W2 of the second portion P2 of the discharge tube 2300. Thus, even when the guide structure 2400 is coupled to the discharge tube 2300, the flow path for the synthesis gas produced through plasma reforming may not be reduced (because the first design condition is satisfied), and a gap for gas flow may be formed between the discharge tube 2300 and the guide structure 2400 (because the second design condition is satisfied).

[0208] By utilizing the guide structure 2400, the second subfeed flow and vapor may be introduced relatively far from the plasma induction region (PIR) and flow to the downstream end of the plasma induction region (PIR). In this case, thermal damage can be prevented because the gas inlet or gas flow pipe, which may be susceptible to thermal damage due to the high temperature of the plasma (approximately 800°C), is located away from the plasma. Here, at least a portion of the guide structure 2400 may be formed of a heat-resistant material such as at least one of aluminum oxide, silicon nitride, silicon dioxide, yttrium oxide, ceramic, silicon carbide, and combinations thereof.

[0209] The method and structure for supplying the second subfeed flow and steam will be described below with reference to Figures 14A and 14B.

[0210] Figure 14 shows a first gas supply nozzle N1 and a second gas supply nozzle N2 according to one embodiment.

[0211] Referring to Figure 14A, the first gas supply nozzle N1 may be understood as a nozzle to which a second subfeed flow is supplied, and the second gas supply nozzle N2 may be understood as a nozzle to which steam is supplied. Therefore, the first gas supply nozzle N1 may be connected to the second gas separation pipe 1220, and the second gas supply nozzle N2 may be connected to the steam supply module 2600.

[0212] Specifically, the first gas supply nozzle N1 and the second gas supply nozzle N2 may be designed so that the gas supply direction is tangential to the outer wall of the guide structure 2400. Therefore, the gas injected from the first gas supply nozzle N1 and the second gas supply nozzle N2 may flow along the outer wall of the guide structure 2400.

[0213] The first gas supply nozzle N1 and the second gas supply nozzle N2 may be arranged so that the gas is supplied in the same direction relative to the central axis of the guide structure 2400. For example, the first gas supply nozzle N1 and the second gas supply nozzle N2 may be arranged so that the gas is supplied in a clockwise or counterclockwise direction relative to the central axis of the guide structure 2400.

[0214] Here, the first gas supply nozzle N1 and the second gas supply nozzle N2 may be arranged to have a predetermined angle. For example, the virtual central axis of the first gas supply nozzle N1 and the virtual central axis of the second gas supply nozzle N2 may form a nozzle angle NA.

[0215] The nozzle angle NA may be designed to be closer to 0° or 180° rather than 90°.

[0216] Each of the first gas supply nozzle N1 and the second gas supply nozzle N2 may be positioned at a predetermined angle with respect to a direction parallel to the central axis of the guide structure 2400. This is to ensure that the first and second gas supply nozzles N1 and N2 inject gas from the bottom of the guide structure 2400 and that the injected gas flows more quickly toward the top of the guide structure 2400.

[0217] The first gas supply nozzle N1 and the second gas supply nozzle N2 may be connected to the stepped sections of the guide structure 2400. For example, referring to Figure 14B, the guide structure 2400 may include a first stepped section 2420 and a second stepped section 2430. In this case, the first gas supply nozzle N1 may be connected to the first stepped section 2420, and the second gas supply nozzle N2 may be connected to the second stepped section 2430. Each of the stepped sections of the guide structure 2400 may include a nozzle coupling, a flow path, and a gas inlet hole. Each of the gas supply nozzles may be coupled to the nozzle coupling of the stepped section, allowing the gas supplied from the gas supply nozzle to be introduced into the space between the outer wall of the guide structure 2400 and the inner wall of the discharge tube 2300 via the flow path and gas inlet hole.

[0218] The first stage 2420 and the second stage 2430 may have different heights with respect to the central axis of the guide structure 2400. For example, referring to Figure 14B, the first stage 2420 may be located lower than the second stage 2430. This is to ensure that the first gas supply nozzle N1 and the second gas supply nozzle N2 supply gas to the outer wall of the guide structure 2400 at different heights.

[0219] On the other hand, both the first gas supply nozzle N1 and the second gas supply nozzle N2 may be connected to either the first stage 2420 or the second stage 2430. Alternatively, the first gas supply nozzle N1 may be connected to the second stage 2430, and the second gas supply nozzle N2 may be connected to the first stage 2420.

[0220] The additional reaction module 2700 of the plasma modification unit 2000 and the additional reactions performed in the additional reaction module 2700 will be described below with reference to Figures 15A and 15B.

[0221] Figure 15A shows an additional reaction module 2700 according to one embodiment.

[0222] Figure 15B shows the insulating structure of an additional reaction module 2700 according to one embodiment.

[0223] The additional reaction module 2700 may be understood as a configuration for improving the gas conversion efficiency within the plasma reforming unit 2000. In other words, the additional reaction module 2700 is a configuration for additionally reacting gas that remains unreacted after plasma reforming.

[0224] Referring to Figure 15A, the additional reaction module 2700 may include a mesh filter MN, a catalyst, a first insulating structure IS1, and a second insulating structure IS2.

[0225] The additional reaction module 2700 may be located below the discharge tube 2300 or the guide structure 2400. In other words, the additional reaction module 2700 may be located in a region through which the plasma-reforming gas PRG has passed before reaching the post-treatment unit 3000.

[0226] The additional reaction module 2700 may be understood as essentially a configuration for inducing a catalytic reaction. Therefore, the additional reaction module 2700 may include a catalyst and a mesh filter MN on which the catalyst is placed. Specifically, the mesh filter MN may be positioned in place by a support, and the catalyst may be placed on the mesh filter MN.

[0227] On the other hand, catalytic reactions require high-temperature conditions for catalyst activation. These high-temperature conditions for catalytic reactions may be achieved by utilizing waste heat (or residual heat) from the plasma. In this case, the mesh filter MN may be made of a material resistant to corrosion and high temperatures to prevent damage from the high-temperature environment for catalytic reactions or from the catalyst itself. For example, the mesh filter MN may be made from materials such as Inconel, stainless steel, iron-chromium, nickel, or Monel.

[0228] Furthermore, a first insulating structure IS1 and a second insulating structure IS2 may be used to satisfy the high-temperature conditions required for the catalytic reaction. The first insulating structure IS1 and the second insulating structure IS2 are configured to prevent external heat from affecting the catalyst and to provide double insulation to the catalyst portion.

[0229] Referring to Figure 15A, the second insulating structure IS2 may be arranged to surround the catalyst, and the first insulating structure IS1 may be arranged to surround the second insulating structure IS2.

[0230] Each of the first insulating structure IS1 and the second insulating structure IS2 may be at least partially made of a heat-resistant material such as at least one of aluminum oxide, silicon nitride, silicon dioxide, yttrium oxide, ceramic, silicon carbide, or a combination thereof.

[0231] Referring to Figure 15B, the first insulating structure IS1 and the second insulating structure IS2 may have a cylindrical shape. Furthermore, the second insulating structure IS2 may have multiple grooves formed on its outer surface. Therefore, as shown in Figure 15A, a gap may be formed between the first insulating structure IS1 and the second insulating structure IS2, thereby improving thermal insulation performance.

[0232] On the other hand, the additional reaction module 2700 may be omitted.

[0233] The gas that has passed through the additional reaction module 2700 may flow to the post-treatment unit 3000. For the sake of explanation, the gas that flows to the post-treatment unit 300 will be referred to as synthesis gas SG below.

[0234] [Post-processing unit] The post-processing unit 3000 will be described below with reference to Figures 16 to 21. 1. Configuration of the post-processing unit Figure 16 shows a plasma modification unit 2000 and a post-treatment unit 3000 according to one embodiment.

[0235] Referring to Figure 16, the post-processing unit 3000 may include a first heat exchange module 3100, a second heat exchange module 3200, a compressor 3300, a gas conversion module 3400, a post-processing gas separation module 3500, and a gas recovery unit 3600.

[0236] The post-processing steps performed in the post-processing unit 3000 may be broadly understood to include gas conversion and gas separation processes. The main components of these processes are the gas conversion module 3400 and the post-processing gas separation module 3500.

[0237] Firstly, the synthesis gas SG generated in the plasma reforming unit 2000 may flow to the gas conversion module 3400 and be subjected to a reaction in which hydrogen or carbon monoxide in the synthesis gas is converted to a specific gas. At this time, the configuration or structure of the gas conversion module 3400 may change depending on the type of final product produced by the gas reforming system 100, and the type of reaction induced may also differ.

[0238] For example, the gas conversion module 3400 may be a water-gas shift (WGS) module. The WGS module may perform a process that converts carbon monoxide in synthesis gas to hydrogen through a catalytic reaction. Specifically, the WGS module may receive synthesis gas and vapor and induce the following reactions. CO + H2O → CO2 + H2

[0239] For a water-gas shift module, the conditions for the water-gas shift reaction are as follows: i) the internal temperature should be approximately 180°C to 250°C or approximately 300°C to 450°C; ii) there are no particular restrictions on the internal pressure, but it should preferably be approximately 10 bar (1 MPa); and iii) the hydrogen to carbon monoxide ratio (H2 / CO) in the supplied gas should be approximately 3 to 10. However, the conditions for the water-gas shift reaction are not limited to those described above.

[0240] In a water-gas shift module, the catalyst may be an oxide of a metal such as iron, nickel, or chromium, and a reducing agent must be added to activate the catalyst.

[0241] If the final product generated in the gas reforming system 100 is high-purity hydrogen, a water-based gas shift module may be selected as the gas conversion module 3400. Alternatively, in a process of recovering carbon dioxide through the gas reforming system 100, a water-based gas shift module may be selected as the gas conversion module 3400.

[0242] In another example, the gas conversion module 3400 may be a Fischer-Tropsch treatment module. The Fischer-Tropsch treatment module may perform a process to synthesize liquid hydrocarbons from synthesis gas via a catalytic reaction. Specifically, the Fischer-Tropsch treatment module receives synthesis gas and induces the following reaction: (2n+1)H2+(n)CO→C (n) H (2n+2) +(n)H2O For the Fischer-Tropsch treatment module, the conditions for the above reaction are as follows: i) the internal temperature should be about 220°C to 230°C (if the catalyst is cobalt) or about 300°C to 320°C (if the catalyst is iron); ii) the internal pressure should be about 20 bar (2 MPa) (if the catalyst is either cobalt or iron); and iii) the hydrogen to carbon monoxide ratio (H2 / CO) in the supplied gas should be about 2.0 to 2.1.

[0243] However, the conditions for the Fischer-Tropsch reaction are not limited to those described above.

[0244] In the Fischer-Tropsch treatment module, the catalyst may be an oxide of a metal such as iron, cobalt, ruthenium, nickel, or chromium, and a reducing agent must be added to activate the catalyst.

[0245] If the final product generated in the gas reforming system 100 is aviation fuel, a Fischer-Tropsch treatment module may be selected as the gas conversion module 3400.

[0246] In another example, the gas conversion module 3400 may be a methanol synthesis module. The methanol synthesis module may be implemented as a fixed-bed reactor or a fluidized-bed reactor and may perform the process of synthesizing methanol from synthesis gas through a catalytic reaction.

[0247] For methanol synthesis modules, the conditions for methanol synthesis are as follows: i) the internal temperature should be approximately 240°C to 260°C; ii) the internal pressure should be approximately 50 to 80 bar (5 to 8 MPa); and iii) the hydrogen to carbon monoxide ratio (H2 / CO) in the supplied gas should be approximately 2.6.

[0248] However, the conditions for methanol synthesis are not limited to those described above.

[0249] In the methanol synthesis module, the catalyst may be an oxide of zinc, chromium, copper-zinc, or copper-manganese, and a reducing agent must be added to activate the catalyst.

[0250] If the final product generated in the gas reforming system 100 is methanol, a methanol synthesis module may be selected as the gas conversion module 3400.

[0251] On the other hand, the gas conversion module 3400 may be configured as a processing module other than those described above, or it may be composed of multiple processing modules.

[0252] The gas released through the gas conversion module 3400 may be supplied to the post-treatment gas separation module 3500. For convenience of explanation, the gas released from the gas conversion module 3400 will hereafter be referred to as the intermediate product (IP).

[0253] The post-processing gas separation module 3500 may perform a gas separation process. The gas separation process performed in the post-processing gas separation module 3500 may be understood as a process that improves the yield efficiency of the final product.

[0254] The post-processing gas separation module 3500 may be implemented using a pressure swing adsorption (PSA) method. The PSA method separates gases by using an adsorbent to preferentially adsorb highly selective components from the pass-through gas, thereby allowing less selective components to be released first.

[0255] The post-treatment gas separation module 3500 may be implemented in a form including a separation membrane, similar to the pre-treatment gas separation module 1200 described above.

[0256] The gas released from the post-treatment gas separation module 3500 may be recovered as final product FP in the gas recovery unit 3600. Additional configurations for changing pressure or temperature may be provided between the post-treatment gas separation module 3500 and the gas recovery unit 3600.

[0257] The first heat exchange module 3100 and the second heat exchange module 3200 may function to control the temperature of the gas passing through them.

[0258] The temperature of the plasma induced in the plasma reforming unit 2000 is in the range of approximately 800°C to 2000°C, and therefore the temperature of the synthesis gas SG may also reach several hundred°C to 2000°C. As mentioned above, since the temperature conditions for gas conversion are relatively low, it is necessary to cool the synthesis gas SG to lower its temperature.

[0259] In other words, the first heat exchange module 3100 and the second heat exchange module 3200 may cool the synthesis gas passing through them so that the temperature of the synthesis gas reaches the temperature required for the gas conversion process.

[0260] The second heat exchange module 3200 may receive water and release steam. Specifically, the second heat exchange module 3200 may generate and release steam by cooling the supplied synthesis gas SG and transferring its thermal energy to water. The steam released from the second heat exchange module 3200 may flow to the gas conversion module 3400.

[0261] The first heat exchange module 3100 and the second heat exchange module 3200 may be implemented in various forms, such as surface heat exchangers like multi-tube heat exchangers or double-tube heat exchangers, regenerative heat exchangers like rotary regenerative heat exchangers or valve-type annular regenerative heat exchangers, liquid-connected indirect heat exchangers, or direct contact heat exchangers.

[0262] The compressor 3300 may increase the pressure of the gas passing through it. The synthesis gas SG released from the plasma reforming unit 2000 may be at atmospheric pressure or higher. As described above, the pressure requirements for gas conversion are relatively higher than atmospheric pressure, so the synthesis gas SG needs to be pressurized before being supplied to the gas conversion module 3400.

[0263] The compressor 3300 may increase the pressure of the supplied synthesis gas SG.

[0264] The compressor 3300 may be implemented as a reciprocating compressor, a rotary compressor, a screw compressor, or a centrifugal compressor.

[0265] 2. Path from the plasma reforming unit to the gas conversion module On the other hand, the synthesis gas SG released from the plasma reforming unit 2000 may reach the gas conversion module 3400 via at least two paths. The paths through which the synthesis gas SG flows to the gas conversion module 3400 will be described below with reference to Figure 17. Figure 17 shows a structure that enables the synthesis gas SG to flow to the gas conversion module 3400 according to one embodiment. Referring to Figure 17, the post-treatment unit 3000 may include a first valve 3110, a second valve 3210, a third valve 3220, and a fourth valve 3230 to control the gas flow. The first to fourth valves 3110, 3210, 3220, and 3230 may be used to determine the timing of the fluid flow in the pipes in which they are installed, and at least one of these valves may be omitted.

[0266] Referring to Figure 17, the first valve 3110 may be installed between the discharge pipe of the plasma reforming unit 2000 and the first heat exchange module 3100, the second valve 3210 may be installed between the discharge pipe of the plasma reforming unit 2000 and the second heat exchange module 3200, the valve 3220 may be installed between the compressor 3300 and the gas conversion module 3400, and the fourth valve 3230 may be installed at any point along the steam inlet pipe.

[0267] Referring to FIG. 17, the synthesis gas SG may flow to the gas conversion module 3400 through at least a first path that passes through the auxiliary gas pipe AGT and the first heat exchange module 3100. Further, the synthesis gas SG may flow to the gas conversion module 3400 through at least a second path that passes through the main gas pipe MGT, the second heat exchange module 3200, and the compressor 3300.

[0268] The first path may be understood as a route for creating a processing preparation environment within the gas conversion module 3400, as described below. For example, in the initial stage of the gas conversion process, the synthesis gas SG may flow to the gas conversion module 3400 through the first path.

[0269] The flow of the synthesis gas SG into the first path may be controlled by the opening and closing operation of the first valve 3110.

[0270] As described below, the second path may be understood as a route for supplying gas to advance the process within the gas conversion module 3400. For example, the synthesis gas SG may flow to the gas conversion module 3400 through the second path when a processing preparation environment is created within the gas conversion module 3400.

[0271] The flow of the synthesis gas SG into the second path may be controlled by the opening and closing operation of the second valve 3210.

[0272] The synthesis gas SG may flow through either the first path or the second path. Alternatively, the synthesis gas SG may flow into the first path simultaneously with flowing into the second path, and vice versa. Hereinafter, for convenience of explanation, the synthesis gas SG flowing through the first path is referred to as the first path flow, and the synthesis gas SG flowing through the second path is referred to as the second path flow. However, it should be understood that these may be referred to by other terms such as the first synthesis gas and the second synthesis gas. Depending on the gas flow control within the post-treatment unit 3000, the whole of the synthesis gas SG may form either the first path flow or the second path flow. Alternatively, the synthesis gas SG may be divided into both the first path flow and the second path flow.

[0273] The first path flow supplied to the gas conversion module 3400 through the first path may have a lower pressure than the second path flow supplied to the gas conversion module 3400 through the second path.

[0274] 3. Gas conversion method Hereinafter, the gas conversion method will be described with reference to FIGS. 18 to 21. FIG. 18 is a diagram showing a gas conversion method according to an embodiment.

[0275] FIGS. 19 to 21 are diagrams showing the processes in which gas conversion according to an embodiment proceeds.

[0276] Referring to FIG. 18, the gas conversion method includes a step of supplying the synthesis gas SG to the first path (S2100); a step of cooling the first path flow (S2200); a step of determining whether processing preparation conditions are satisfied (S2300); a step of supplying the synthesis gas SG to the second path (S2400); a step of cooling and pressurizing the second path flow (S2500); a step of determining whether processing maintenance conditions are satisfied (S2600); and a step of stopping the supply of the synthesis gas SG to the first path (S2700).

[0277] Each step will be described in detail below.

[0278] As mentioned above, for most types of gas conversion modules 3400 to operate, their interiors must reach a specific temperature, and a reducing agent must be supplied to activate the metal oxide catalyst. Therefore, preheating and catalyst activation preparations for the gas conversion module 3400 must be performed before supplying the target gas to be converted.

[0279] Steps S2100, S2200, and S2300 may be understood as steps for preparing the process. Furthermore, steps S2100, S2200, and S2300 may be understood as being performed within an initial reduction section (or first time section). Here, the initial reduction section may also be interpreted as a time section in which the synthesis gas SG is supplied to the gas conversion module 3400 via a first path.

[0280] First, synthesis gas SG may be supplied to the first path S2100. At this time, the synthesis gas SG that is transported to the first path and passes through the first heat exchange module 3100 may be understood as the first path flow.

[0281] The controller of the central control unit or the post-processing unit 3000 may control the first valve 3110 to supply synthesis gas SG to the first heat exchange module 3100. In this case, the time for which the first valve 3110 is open may be within a predetermined time from the time when power is applied to the main antenna module 2230. Alternatively, the time for which the first valve 3110 is open may be within a predetermined time from the time when one of the first subfeed flow, the second subfeed flow, and steam begins to be supplied to the discharge tube 2300. Alternatively, the time for which the first valve 3110 is open may be within a predetermined time from the time when the concentration of synthesis gas SG in the discharge tube 2300 is equal to or greater than a predetermined value. Alternatively, the first valve 3110 may be open even before plasma reforming begins.

[0282] Cooling of the first path flow may be performed in the first heat exchange module 3100 (S2200).

[0283] The first heat exchange module 3100 may cool the first path flow to a first temperature range. Here, the first temperature range may vary depending on the optimal reaction environment of the gas conversion module 3400. For example, if the gas conversion module 3400 is the aqueous-gas shift module described above, the first heat exchange module 3100 may cool the first path flow to a temperature range of 150°C to 400°C. Alternatively, the first temperature range may be the temperature range required to activate the catalyst of the gas conversion module 3400. Alternatively, considering the length of the path from the first heat exchange module 3100 to the gas conversion module 3400, the first temperature range may be a temperature range higher than the optimal reaction temperature of the gas conversion module 3400.

[0284] Referring to Figure 19, the synthesis gas SG may be supplied to the first heat exchange module 3100, and the first path flow cooled in the first heat exchange module 3100 may flow to the gas conversion module 3400. In other words, the entire synthesis gas SG may flow to the gas conversion module 3400 through the first path, and the synthesis gas SG may not flow through the second path.

[0285] In Figure 19, the first path flow that flows through the first path to the gas conversion module 3400 contains hydrogen, which may act as a reducing agent to activate the catalyst in the gas conversion module 3400. Furthermore, since the temperature of the first path flow can be controlled to a level necessary for the catalytic reaction or catalyst activation, the supply of the first path flow through the first path can make the internal environment of the gas conversion module 3400 suitable for initiating processing.

[0286] As described above, when the synthesis gas generated in the plasma reforming unit 2000 is used to create a processing preparation environment for the gas conversion module 3400, no separate equipment is required to preheat the gas conversion module 3400 or activate the catalyst. Therefore, the construction cost of the gas reforming system 100 can be significantly reduced, and the reduction in components can also improve the ease of control within the system.

[0287] As the processing preparation progresses, it may be determined whether the processing preparation conditions are met (S2300). Here, the processing preparation conditions can be understood as criteria for determining whether the processing preparation is complete and whether the gas conversion process can proceed. In other words, once the processing preparation conditions are met, the gas conversion process may proceed in the gas conversion module 3400.

[0288] The processing preparation conditions may vary depending on the type of gas conversion module 3400. For example, if the gas conversion module 3400 is a water-gas shift module, the processing preparation conditions may include the following conditions and combinations thereof: a first condition in which the internal temperature is maintained within the range of approximately 150°C and approximately 400°C; a second condition in which a predetermined proportion or more of the catalyst is activated; and a third condition in which a predetermined time has elapsed since the synthesis gas SG began to be supplied to the first pathway. Here, a component analysis device may be used to determine whether the second condition is met. The component analysis device may, for example, monitor the amount of hydrogen in the gas conversion module 3400 (e.g., hydrogen peak) and determine whether the catalyst is activated based on the degree of decrease in the amount of hydrogen.

[0289] If the processing preparation conditions are not met, the synthesis gas SG may continue to be supplied to the first heat exchange module 3100. This indicates that the supply of synthesis gas SG to the first heat exchange module 3100 will continue without interruption. Alternatively, the synthesis gas SG may be supplied to the first heat exchange module 3100 for a predetermined period only, and if the processing preparation conditions are not met, the synthesis gas SG may be supplied to the first heat exchange module 3100 again for another predetermined period.

[0290] When the processing preparation conditions are met, synthesis gas SG may be supplied to the second pathway (S2400). The time section in which synthesis gas SG is supplied to the second pathway may be understood as the main reaction section (or second time section). At this time, the synthesis gas SG transferred to the second pathway and passing through the second heat exchange module 3200 may be understood as the second pathway flow.

[0291] The controller of the central control unit or the post-processing unit 3000 may control the second valve 3210 to supply the synthesis gas SG to the second heat exchange module 3200. At this time, the opening time of the second valve 3210 may be after the above processing preparation conditions are satisfied.

[0292] On the other hand, the opening time of the second valve 3210 may be before the closing time of the first valve 3110. For example, since the pressurization process in the compressor 3300 in the second path may require a predetermined time, the second valve 3210 may open before the first valve 3110 closes, and the third valve 3220 may be controlled to remain closed. This ensures that the second path flow is pressurized before the processing preparation conditions are satisfied but remains not supplied to the gas conversion module 3400. At this time, steam may also be generated, but it can be controlled by the fourth valve 3230 so that it is not supplied to the gas conversion module 3400.

[0293] On the other hand, when the fourth valve 3230 is open, at least one of the first valve 3110 and the third valve 3220 needs to be open. In other words, it is necessary to prevent steam from being supplied to the gas conversion module 3400 alone. This is because supplying steam to the activation catalyst alone may cause a decrease in catalyst performance.

[0294] The cooling and pressurization of the second path flow may be performed (S2500). Specifically, the second path flow may be cooled in the second heat exchange module 3200 and pressurized in the compressor 3300.

[0295] The second heat exchange module 3200 may cool the supplied second path flow to a second temperature range, where the second temperature range may correspond to a room temperature range (approximately 15°C to 20°C). Before pressurization by the compressor 3300, the second path flow needs to have moisture removed using a dehumidification module (not shown); therefore, the room temperature range may be understood as a suitable temperature range for effective moisture removal. The second temperature range may also be determined by further considering the length of the path from the second heat exchange module 3200 to the gas conversion module 3400.

[0296] The first temperature range in which the first path flow is cooled by the first heat exchange module 3100 may differ from the second temperature range in which the second path flow is cooled by the second heat exchange module 3200. For example, the minimum value of the first temperature range may be higher than the maximum value of the second temperature range.

[0297] The first temperature range in which the first path flow is cooled by the first heat exchange module 3100 may be the same as the second temperature range in which the second path flow is cooled by the second heat exchange module 3200.

[0298] Referring to Figure 20, the synthesis gas SG may be supplied to a second heat exchange module 3200, and the second path flow cooled by the second heat exchange module 3200 may flow to a compressor 3300, be pressurized, and then flow to a gas conversion module 3400. The temperature of the second path flow before being supplied to the gas conversion module 3400 may be about 150°C, and for this purpose, a separate heating module may be provided. The fluid flow from the compressor 3300 to the gas conversion module 3400 may be controlled by the opening and closing operation of a third valve 3220.

[0299] When the second path flow flows to the gas conversion module 3400, the gas conversion process may proceed, and the gas conversion module 3400 may release intermediate product IP. The released intermediate product IP may be supplied to the post-processing gas separation module 3500.

[0300] At this time, as described above, the water may receive thermal energy from the second heat exchange module 3200 and be converted into steam, which may be supplied to the gas conversion module 3400 through a separate pipe. Here, the steam may play a role in maintaining the internal temperature of the gas conversion module 3400 at the optimal reaction temperature. Furthermore, depending on the type of gas conversion module 3400, the steam may also be used to produce the target intermediate product IP by reacting with the supplied synthesis gas (e.g., carbon monoxide or carbon dioxide). Depending on the type of gas conversion module 3400, steam may not be supplied. The flow of steam may be controlled by the opening and closing operation of the fourth valve 3230.

[0301] On the other hand, referring to Figure 20, if a portion of the synthesis gas SG flows through the second path, another portion of the synthesis gas SG may be continuously (or periodically) supplied to the gas conversion module 3400 through the first path. This is because if the supply of the first path flow through the first path is stopped immediately when the supply of the second path flow through the second path begins, the environment (e.g., temperature conditions) created for the catalytic reaction within the gas conversion module 3400 may deteriorate, potentially resulting in a decrease in the catalytic reaction rate.

[0302] Therefore, as explained below, the point at which the supply of synthesis gas SG through the first route is stopped must be precisely determined, taking into account the treatment maintenance conditions.

[0303] The gas conversion method may determine whether or not the processing maintenance conditions are met (S2600). The processing maintenance conditions may refer to the criteria for maintaining the gas conversion process.

[0304] The processing maintenance conditions may vary depending on the type of gas conversion module 3400. For example, if the gas conversion module 3400 is a water-gas shift module, the processing maintenance conditions may include the following conditions and combinations thereof: a first maintenance condition in which the internal temperature is maintained within the range of approximately 150°C and approximately 400°C for a predetermined time equal to or longer than that; a second maintenance condition in which a predetermined proportion or more of the catalyst is activated; a third maintenance condition in which a predetermined time has elapsed since the synthesis gas SG began to be supplied to the second pathway; and a fourth maintenance condition in which the amount of vapor supplied to the gas conversion module 3400 is equal to or greater than a predetermined amount. Here, the component analysis device may be used to determine whether the second maintenance condition is met.

[0305] If the processing maintenance conditions are not met, the synthesis gas SG may be continuously supplied to the second heat exchange module 3200. In this case, the supply of synthesis gas SG through the first path does not need to be stopped. This can be understood as meaning that the supply of synthesis gas (SG) through the first path needs to be maintained until the processing maintenance conditions are met.

[0306] If the processing maintenance conditions are met, the supply of synthesis gas SG to the first heat exchange module 3100 may be stopped (S2700). The controller of the central control unit or the post-processing unit 3000 may control the first valve 3110 to stop the flow of synthesis gas SG through the first path.

[0307] At this time, the closing time of the first valve 3110 may be after the above-mentioned processing maintenance conditions have been met.

[0308] Referring to Figure 21, the entire synthesis gas SG may flow to the gas conversion module 3400 through the second path, the steam may flow to the gas conversion module 3400 through another path, and the synthesis gas SG may not flow through the first path.

[0309] As described above, the gas conversion method may be divided into a processing preparation process (steps S2100, S2200, and S2300) and a processing progress process (steps S2400, S2500, S2600, and S2700).

[0310] Here, the synthesis gas reformed in the plasma reforming unit 2000 may be used for both the preparation for the gas conversion process and the gas conversion process itself. However, if the start of the gas conversion process is excessively delayed or the preparation for the process continues unnecessarily, a situation may arise where the synthesis gas to be converted is wasted during the preparation for the process. Therefore, steps S2300 and S2600 can be understood as important steps to prevent unnecessary waste of synthesis gas and further prevent a decrease in the efficiency of the gas conversion process (or the overall efficiency of the gas reforming system 100), in that the synthesis gas SG is supplied through the second path as quickly as possible once the preparation for the process is met, and the supply of synthesis gas SG through the first path is stopped as quickly as possible once the maintenance for the process is met.

[0311] The features, structures, effects, etc., described in the embodiments are included in, and not necessarily limited to, at least one embodiment of this disclosure. Furthermore, the features, structures, effects, etc., provided in each embodiment can be combined or modified in other embodiments by those skilled in the art to which the embodiment belongs. Accordingly, matters relating to combinations and modifications should be construed as being within the scope of this disclosure.

[0312] Furthermore, the embodiments described herein are provided for illustrative purposes only, and those skilled in the art will understand that various modifications, additions, and substitutions are possible without departing from the scope and spirit of the disclosure. In other words, each element specifically shown in the embodiments can be implemented in a modified form. Therefore, any differences relating to modifications and applications should be construed as being within the scope of the disclosure disclosed in the appended claims.

Claims

1. (1) A step of supplying desulfurization feed gas to a first gas separation module to form a first subfeed flow and a second subfeed flow, Here, the first gas separation module includes a porous separation membrane, Here, the first subfeed flow includes the desulfurization feed gas that does not pass through the porous separation membrane. Here, the second subfeed flow includes the desulfurization feed gas passing through the porous separation membrane, Here, the molar ratio of carbon dioxide in the first subfeed stream is higher than the molar ratio of carbon dioxide in the second subfeed stream. Here, the molar ratio of methane in the first subfeed stream is lower than the molar ratio of methane in the second subfeed stream; (2) The first subfeed flow, the second subfeed flow, and steam (H ２ A step of supplying O) to a plasma reforming unit to form a synthesis gas containing at least hydrogen and carbon monoxide, Here, the first subfeed flow is configured to be supplied to the upstream end of the plasma induction region defined by the discharge tube of the plasma modification unit, Here, the second subfeed flow and the steam are configured to be supplied to the downstream end of the plasma induction region. Here, the first subfeed flow, the second subfeed flow, and the vapor are configured to be modified by the plasma generated in the plasma induction region, and thus form a synthesis gas; (3) A step of forming an intermediate product by supplying the synthesis gas to a gas conversion module. Here, in the initial reduction section, the synthesis gas is configured to be supplied to the gas conversion module through a first path in the initial reduction section, and the supplied synthesis gas can be used as a reducing agent for the catalyst in the gas conversion module. Here, in the main reaction section, the synthesis gas is configured to be supplied to the gas conversion module through a second pathway, and the supplied synthesis gas can be converted to obtain the intermediate product. Here, the pressure of the synthesis gas supplied to the gas conversion module through the first path in the initial reduction section is lower than the pressure of the synthesis gas supplied to the gas conversion module through the second path in the main reaction section; and, (4) A step in which the intermediate product is supplied to the second gas separation module to form the final product. A method for reforming gas, comprising [a specific component / feature].

2. The step of forming the synthesis gas involves generating the plasma by supplying a seed gas to the upstream end of the plasma induction region and supplying power to an auxiliary antenna module configured to surround at least a portion of the discharge tube; and, The plasma discharge is maintained by supplying power to a main antenna module configured to surround at least a portion of the discharge tube. The method according to claim 1, comprising:

3. The seed gas is configured to be supplied to the plasma induction region from the first time point to the second time point. The method according to claim 2, wherein the first subfeed flow is configured to be supplied to the plasma induction region from a third time point after the first time point to a fourth time point after the second time point.

4. The method according to claim 3, wherein the second time point at which the supply of the seed gas is stopped is after the time at which power is supplied to the main antenna module.

5. The step of forming the aforementioned synthesis gas is, The method includes controlling the flow rate of the first subfeed flow, the flow rate of the second subfeed flow, and the flow rate of the steam so that the ratio of methane, carbon dioxide, and steam supplied to the plasma induction region is within a predetermined range; The molar ratio of hydrogen to carbon monoxide in the synthesis gas (H ２ The method according to claim 1, wherein the / CO) is configured to be in the range of 1.8 to 2.

7.

6. The method according to claim 1, wherein the direction in which the first subfeed flow is supplied to the plasma induction region and the direction in which the second subfeed flow is supplied to the plasma induction region are configured to be opposite to the central axis of the discharge tube.

7. A step in which an additional reaction is performed on the synthesis gas formed by plasma reforming using an additional reaction module configured to be located at the bottom of the discharge tube. Furthermore, The method according to claim 1, wherein the additional reaction module is configured to induce a catalytic reaction with the synthesis gas and increase the molar ratio of hydrogen in the synthesis gas.

8. The gas conversion module is a water-gas shift (WGS) module, The molar ratio of carbon monoxide in the intermediate product is lower than the molar ratio of carbon monoxide in the synthesis gas. The method according to claim 1.

9. The step of forming the intermediate product is, Cooling the synthesis gas transferred to the first path using the first heat exchange module in the initial reduction section; and In the main reaction section, the synthesis gas transferred to the second path is cooled and pressurized using the second heat exchange module and compressor. The method according to claim 1, comprising:

10. The first heat exchanger module is configured to cool the supplied gas to a first temperature range. The second heat exchanger module is configured to cool the supplied gas to a second temperature range. The minimum value in the first temperature range is higher than the maximum value in the second temperature range. The method according to claim 9.

11. The first valve is configured to control the flow of the synthesis gas into the first path. The second valve is configured to control the flow of the synthesis gas into the second path. The method according to claim 1.

12. The step of forming the aforementioned synthesis gas is, By supplying power to the auxiliary antenna module and the main antenna module, which are arranged adjacent to the discharge tube, plasma is induced in the plasma induction region. Includes, The opening time of the first valve is configured to be within a predetermined time from the moment power is supplied to the main antenna module. The method according to claim 11.

13. The closing time of the first valve is configured to occur after the temperature inside the gas conversion module reaches a predetermined temperature. The method according to claim 11.

14. The opening time of the second valve is configured to occur after the temperature inside the gas conversion module reaches a predetermined temperature. The method according to claim 11.

15. The closing time of the first valve is configured to occur after the opening time of the second valve, and therefore the initial reduction section and the main reaction section are configured to overlap at least partially. The method according to claim 11.

16. The step of forming the final product involves using an adsorbent in the second gas separation module to adsorb a specific gas from the intermediate product. The method according to claim 1.

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