Hydrogen generation system

Abstract

Provided is a hydrogen generation system for generating hydrogen using waste heat from a hydrogen utilization device, wherein hydrogen can be generated by thermally decomposing an organic compound having a carbon atom, a hydrogen atom and a hydroxy group by using the waste heat.

Description

Hydrogen generation system

[0001] This disclosure relates to a hydrogen generation system.

[0002] Hydrogen is attracting attention as a clean energy source that does not emit carbon dioxide and has no adverse effects on the human body. For example, in the automotive industry, the development of automobiles using hydrogen engines and hydrogen fuel cells fueled by hydrogen is underway. As one method of obtaining such hydrogen, for example, the steam reforming method of mixing steam with fossil fuel gas such as methane and causing a chemical reaction at a high temperature to obtain hydrogen is widely used (see Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2007-009917

[0004] According to the method (steam reforming method) disclosed in Patent Document 1, methanol and water can be reacted to generate hydrogen, but at the same time, a large amount of carbon dioxide is also generated, and there is concern about the environmental load.

[0005] This disclosure has been made in view of such problems. That is, an object is to provide a hydrogen generation system that can suitably generate hydrogen while avoiding the generation of carbon dioxide.

[0006] In order to achieve the above object, in one embodiment of the present disclosure, there is provided a system for generating hydrogen by using waste heat of a hydrogen utilization device, wherein the waste heat can thermally decompose an organic compound having a carbon atom, a hydrogen atom, and a hydroxy group to generate hydrogen.

[0007] Also, in order to achieve the above object, in one embodiment of the present disclosure, there is provided a system for generating hydrogen by using waste heat of a hydrogen production device, wherein the waste heat can thermally decompose an organic compound having a carbon atom, a hydrogen atom, and a hydroxy group to generate hydrogen.

[0008] According to the hydrogen generation system according to one embodiment of the present disclosure, it is possible to provide a hydrogen generation system that can suitably generate hydrogen while avoiding the generation of carbon dioxide.

[0009] Figure 1 is a schematic diagram showing a first embodiment of the hydrogen generation system according to the present invention. Figure 2 is a schematic diagram showing a second embodiment of the hydrogen generation system according to the present invention. Figure 3 is a schematic diagram showing a discharge device, which is a component of the hydrogen generation system according to the present invention.

[0010] Embodiments of this disclosure will be described in detail below with reference to the drawings. Components in the following embodiments that are not described in an independent claim will be described as optional components. Furthermore, the sizes and size ratios of the components shown in the drawings are not necessarily precise. In addition, substantially identical components are denoted by the same reference numerals in each drawing, and redundant explanations may be omitted or simplified.

[0011] Furthermore, the following description uses terminology to indicate specific directions and locations as needed. However, the use of these terms is for the purpose of facilitating the understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of this disclosure. Unless otherwise noted, the same reference numerals or symbols indicate the same component or part or have the same meaning.

[0012] The description of the exemplary embodiments of this disclosure is intended to be read in conjunction with the accompanying drawings (drawings that are deemed to be part of the entire description). In the description of embodiments of this disclosure disclosed in this specification, references to directions or orientations are for illustrative purposes only and are not intended to limit the scope of this disclosure. Relative terms such as “downward,” “upward,” “top,” “down,” and their derivative terms such as “downward,” “upward,” etc., should be understood to refer to directions as described or illustrated. Such relative terms are for illustrative purposes only and do not require that each element be composed of or positioned in a particular direction unless otherwise explicitly stated.

[0013] Furthermore, terms such as “attached” and “connected,” and similar terms, unless otherwise explicitly stated, indicate a relationship in which structures are directly or indirectly fixed or attached to each other by an intermediary, or that both are movable or rigidly attached or in that relationship.

[0014] The embodiments of this disclosure will be described below with reference to the drawings, but this disclosure is not limited thereto. The components of the embodiments described below can be combined as appropriate. Some components may also be omitted. Furthermore, the components of the embodiments described below include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and so-called equivalents.

[0015] Furthermore, the features or benefits of this disclosure are illustrated by reference to preferred embodiments. Such embodiments are described in sufficient detail to enable those skilled in the art to implement this disclosure. It should also be understood that other embodiments are available and that process, thermal, or mechanical modifications are possible without departing from the scope of this disclosure. Therefore, this disclosure is not expressly limited to preferred embodiments (individually or in combination with other features) that illustrate a non-restrictive combination of possible features.

[0016] First, an overview of one embodiment of the hydrogen generation system of this disclosure is described below.

[0017] [Hydrogen Generation System] Figure 1 is a schematic diagram showing a first embodiment of the hydrogen generation system 100 according to the present invention. In the hydrogen generation system 100, a liquid organic compound having carbon atoms, hydrogen atoms, and hydroxyl groups is thermally decomposed to produce hydrogen. The main components of the hydrogen generation system 100 may include a first holding tank 10, a hydrogen utilization device 20, a first piping 30, a discharge device 40, a recovery unit 50, and pumps 60 and 61.

[0018] The basic components of the hydrogen generation system 100 described above will be explained in detail below. (First holding tank 10) The first holding tank 10 is a tank capable of holding the above-mentioned liquid organic compound inside. The first holding tank 10 is preferably a container that is highly airtight and corrosion resistant. It is also preferable to have a vent valve or the like, as the organic compound may volatilize. Furthermore, it is even more preferable to have an insulating material and a temperature control system that can withstand temperature fluctuations inside the tank. The material of this holding tank may be, for example, stainless steel and a tank with a corrosion-resistant coating.

[0019] (Hydrogen utilization device 20) The hydrogen utilization device 20 is a device that operates and is powered by hydrogen. Although this is merely an example, the hydrogen utilization device 20 may be a hydrogen engine, fuel cell, hydrogen combustion boiler, hydrogen turbine, hydrogen power generation system, ammonia synthesis device, hydrogen burner and industrial furnace, hydrogen co-firing compatible gas equipment, for example, a hydrogen reduction furnace for reducing iron oxide. When the hydrogen utilization device 20 reacts using hydrogen, it is preferable that it dissipates heat to a temperature of about 200°C or higher, which is the temperature at which organic compounds can be thermally decomposed, and to about 600°C without combustion of hydrogen. However, it is not limited to the above device, and may be, for example, a hydrogen production device and a hydrogen flare stack.

[0020] (First pipe 30 and second pipe 31) The first pipe 30 is a hollow pipe for supplying a liquid organic compound having carbon atoms, hydrogen atoms, and hydroxyl groups. The second pipe 31, on the other hand, is a hollow pipe that connects the hydrogen utilization device 20 to the recovery unit 50 described later and supplies hydrogen to the hydrogen utilization device 20. Both pipes may be made of corrosion-resistant metals such as stainless steel or copper, or corrosion-resistant synthetic resins with high thermal conductivity. The inner diameter can be selected to various sizes depending on the application of the hydrogen utilization device 20, and may be, for example, about 5 to 10 mm, about 10 to 20 mm, or about 25 to 50 mm, but is not limited to these. It should be noted that the pipe 30 is composed of three regions I, II, and III, and in Figures 1 and 2, each region is shown with a dashed line to distinguish it from the pipe shown with a solid line. Also, the pipe 31A in Figure 2 is composed of two regions X and Y, and these regions are shown with a dashed line, similar to regions I to III.

[0021] (Third piping 32) The third piping 32 for air intake is a hollow pipe for supplying air to the hydrogen utilization device 20, and may be made of a durable and corrosion-resistant material. Examples of materials that can be used include, but are not limited to, aluminum alloy, high-strength plastic, and silicon. Furthermore, it is desirable that the third piping 32 be equipped with an air filter. The air filter filters the air taken in from the outside, removing foreign matter and contaminants, thereby supplying clean air.

[0022] (Discharge device 40) The discharge device 40 may be used depending on the application and size of the hydrogen generation system 100. This is merely an example and not an limitation, but the discharge device 40 may be a plasma discharge device using arc discharge, glow discharge, or corona discharge generated by methods such as DC, AC, high frequency, or microwave. It is also possible to select the optimal combination of these discharge (or molecular excitation) methods depending on the process.

[0023] (Collection Unit 50) The collection unit 50 is an open-topped container for collecting gas, and may be made of glass and / or transparent resin, for example. It may also have a supply pipe for collecting gas generated by the discharge device 40, and may have a level sensor for adjusting the water level in the first holding tank 10.

[0024] (Features of the First Embodiment) Based on the contents of the main components of the hydrogen generation system 100 described above, the features of the first embodiment will be explained below.

[0025] The hydrogen generation system 100 of this disclosure is characterized in that it efficiently generates hydrogen by thermally decomposing a liquid organic compound, which generally has carbon atoms, hydrogen atoms, and hydroxyl groups, using waste heat generated during the operation of a device that uses hydrogen as fuel (i.e., a hydrogen utilization device 20).

[0026] Specifically, when the hydrogen utilization device 20 is activated, a chemical reaction occurs inside it, generating heat. Furthermore, the hydrogen utilization device 20 itself generates operating heat. A portion of this heat is eventually released to the outside as the temperature of the hydrogen utilization device 20 rises. This released heat (i.e., waste heat) is used to thermally decompose organic compounds. Meanwhile, the organic compounds can be thermally decomposed at a predetermined waste heat temperature or higher, producing hydrogen.

[0027] A key feature of the hydrogen generation system 100 of this disclosure is that it can promote the thermal decomposition of organic compounds and contribute to reducing energy consumption by utilizing the waste heat from the hydrogen utilization device 20 itself.

[0028] In other words, the hydrogen generation system 100 of this disclosure utilizes the waste heat of hydrogen utilization devices 20 such as fuel cells and / or hydrogen engines that utilize hydrogen. In addition to hydrogen utilization devices, hydrogen production devices that manufacture hydrogen and hydrogen flare stacks that process hydrogen may also be used. That is, it does not use waste heat from hydrogen-unrelated devices such as gas turbines to pyrolyze organic compounds and produce hydrogen, which are different from hydrogen-related devices such as hydrogen utilization devices such as fuel cells, hydrogen production devices, and hydrogen flare stacks. Therefore, the hydrogen generation system 100 of this disclosure is a system that utilizes the waste heat of hydrogen-related devices such as hydrogen utilization devices (fuel cells, etc.) described later, and does not utilize the waste heat of other hydrogen-unrelated devices such as devices that do not use hydrogen, and thus has high waste heat utilization efficiency.

[0029] Next, the configuration and material flow of the hydrogen generation system 100 of this disclosure, which has the above-described features, will be explained in detail. The first holding tank 10 holds a liquid organic compound having carbon atoms, hydrogen atoms, and hydroxyl groups at room temperature and atmospheric pressure. This organic compound is supplied by a pump 60 from inside the first holding tank 10 to a pipe 30 connected to the tank 10 (corresponding to area I in Figure 1). The organic compound is movable inside the pipe 30, and it is preferable that the pipe 30 is connected below or to the bottom of the first holding tank 10. By connecting it in such a position, it is possible to prevent contamination with oxygen and other substances, and to prevent oxidation reactions and the generation of carbon dioxide during the process in which the organic compound is thermally decomposed, which will be described later.

[0030] More specifically, as organic compounds are supplied, the amount of organic compounds gradually decreases. Therefore, if the piping 30 is connected above the first holding tank 10, a space is created above the first holding tank 10, and unwanted substances such as air and oxygen may enter the piping through the vent valve of the first holding tank 10. As a result, there is a risk that oxygen and organic compounds will react to produce carbon dioxide.

[0031] In contrast, by connecting the piping 30 below the first holding tank 10, the piping 30 can be filled with organic compounds even as supply progresses, and oxidation reactions and steam reforming reactions of the organic compounds cannot occur unless carbon dioxide, water, oxygen, etc. are intentionally added. In other words, the possibility of water and oxygen, etc., accidentally entering the piping 30 is eliminated, and preferably a state in which water and oxygen are absent can be maintained. Therefore, the generation of carbon dioxide can be avoided.

[0032] In contrast, the hydrogen fuel supply device described in Patent Document 1 uses a general steam reforming method, which requires steam in the reaction process and may emit a large amount of carbon dioxide. On the other hand, the hydrogen production system 100 of this disclosure does not require steam, thus eliminating the need for steam supply and production equipment. Furthermore, since thermal decomposition occurs at a low temperature (for example, about 300°C) in a state where no oxygen is present in the piping 30, combustion does not occur, and the process of generating carbon dioxide cannot exist in the hydrogen production system 100. As a result, a major advantage and feature of the hydrogen production system 100 of this disclosure is that it can eliminate carbon dioxide emissions. The thermal decomposition reaction in the piping 30 can proceed without a catalyst, but a catalyst may be used to improve the efficiency of the hydrogen production system 100.

[0033] Next, in region II of the piping 30 in Figure 1, the piping 30 can be arranged adjacent to the outside of the hydrogen utilization device 20. For example, the piping 30 can be arranged to surround the hydrogen utilization device 20, from below to above. The hydrogen generation system 100 of this disclosure aims to obtain hydrogen by thermally decomposing an organic compound using the waste heat of the hydrogen utilization device 20. Due to this configuration, as the organic compound moves through the piping 30, it receives waste heat from the hydrogen utilization device 20, which raises the temperature of the organic compound itself and promotes thermal decomposition.

[0034] The piping 30 is installed so that the waste heat from the hydrogen utilization device 20 is transferred from the outer surface of the hydrogen utilization device 20 to the organic compound inside the piping 30. Specifically, the heat generated when the hydrogen utilization device 20 is driven is released as waste heat from the outer surface of the hydrogen utilization device 20. At this time, since the piping 30, which is made of metal or a material with high thermal conductivity, is located adjacent to the outside of the hydrogen utilization device 20, the thermal energy caused by the waste heat is transferred to the piping 30. As a result, the thermal energy caused by the waste heat from the hydrogen utilization device 20 can be indirectly transferred to the organic compound moving inside the piping 30. When the temperature at which the heat is transferred from the waste heat of the hydrogen utilization device 20 to the organic compound reaches a temperature suitable for the thermal decomposition of the organic compound, hydrogen can be produced from the organic compound.

[0035] As described above, the arrangement of the piping 30 allows for efficient utilization of the waste heat from the hydrogen utilization device 20 (see Area II). Furthermore, since the organic compounds are not thermally decomposed using waste heat from a gas turbine separate from the hydrogen utilization device or heat from a dedicated decomposition reactor, these separate devices are unnecessary, resulting in the advantage of simplifying and miniaturizing the entire system. As an example and not limited to the shape surrounding the outer circumference of the hydrogen utilization device 20, the piping 30 can be spiral-shaped like a heat exchanger along the outer circumference of the hydrogen utilization device 20. In this case, the contact area with the liquid organic compound increases, and as the organic compound passes through, heat can be continuously applied, further improving the heat exchange efficiency.

[0036] In addition, to achieve efficient thermal decomposition in the piping 30, a catalyst may be provided inside the piping 30 (particularly in region II). For example, if the organic compound is butanol, providing a catalyst such as palladium can cause thermal decomposition of butanol at approximately 300-400°C, and if the organic compound is methanol, providing a catalyst such as a copper and nickel-based catalyst can cause thermal decomposition at approximately 200-300°C. In this way, the use of a catalyst lowers the reaction temperature and increases the reaction rate, allowing for efficient thermal decomposition. That is, by installing a catalyst, it is possible to control the reaction inside the piping 30 even more effectively. Depending on the temperature of the waste heat generated from the hydrogen utilization device 20, the hydrogen generation system 100 of this disclosure may be configured to change the catalyst or not use a catalyst.

[0037] The piping 30 surrounding the hydrogen utilization device 20 is installed in such a way that organic compounds can move from bottom to top. Because the generated hydrogen has a smaller molecular weight than air, it can easily move upward through the piping 30.

[0038] However, since it may take several seconds to several minutes for organic compounds to decompose thermally, the piping 30 must be of sufficient length and positioned to effectively transfer waste heat to the organic compounds. In addition, in order to receive the waste heat at an appropriate temperature, it is important to ensure a predetermined distance between the piping 30 and the hydrogen utilization device 20, depending on the waste heat temperature. This minimizes heat loss and maintains optimal heat transfer efficiency. The length of the piping 30 and the distance from the hydrogen utilization device 20 can be appropriately changed depending on the type of hydrogen utilization device 20.

[0039] As the organic compound passes through region II of the pipe 30, it is thermally decomposed to produce hydrogen. In this process, in addition to hydrogen production, carbon monoxide can also be further produced from the organic compound, as shown by the general formula below.

[0040] As can be seen from the following formula, the hydrogen generation system 100 of the present disclosure can generate hydrogen from organic compounds in the absence of water and oxygen. Further, as described above, as long as it is not intended, oxygen and the like are not contained in the pipe 30, so that a combustion reaction does not occur, carbon dioxide and water cannot be generated, and instead unreacted carbon can be generated.

[0041] In the hydrogen generation system 100 of the present disclosure, from the viewpoint of thermal decomposition using waste heat, an organic compound for which the temperature required for thermal decomposition may be relatively low is preferable. That is, it is preferable that the ranges of x, y, and z in the above formula satisfy 1 ≤ x ≤ 12 and 1 ≤ y + z ≤ 2x + 2. With an organic compound within this range, there is a possibility of thermal decomposition at a temperature of about 200°C to about 600°C by receiving the waste heat of a general hydrogen utilization device 20.

[0042] Although carbon monoxide can also be generated as shown in the above formula, in the hydrogen generation system 100, as will be described later, a process for generating acetic acid from carbon monoxide is adopted. On the other hand, in the conventional method, there is a process of burning a gas mainly composed of generated carbon monoxide by using the waste heat of another device (for example, a gas turbine, etc.) that does not use hydrogen or is not related to hydrogen. Therefore, there is a possibility that carbon dioxide is substantially generated as an entire system. Therefore, the hydrogen generation system 100 of the present disclosure is also greatly different from the prior art in that there is no process of generating carbon dioxide. That is, it can be said that it is an environmentally friendly system that can significantly reduce or eliminate the amount of carbon dioxide emissions.

[0043] Further, in the above formula, although not limited, examples of organic compounds include phenols, carboxylic acids, alcohols, etc. Among these, from the viewpoint that the possibility of generating by-products other than hydrogen and carbon monoxide during thermal decomposition is low and the reactivity of thermal decomposition is high, the organic compound is preferably an alcohol, and particularly preferably methanol. Therefore, from the viewpoint of preventing by-products (for example, water and oxygen) other than hydrogen and carbon monoxide from occurring, the relationship between x and z in the above formula is more preferably x ≥ z, and from the viewpoint of not generating carbon (C), it is even more preferably x = z.

[0044] Methanol has only one carbon atom, a small molecular weight, and a very simple molecular structure. Therefore, it easily absorbs thermal energy and thermal decomposition is relatively easy. The C-H bond and C-OH bond of methanol are energetically weaker than these bonds in ethanol, for example, making it easier to cause a thermal decomposition reaction with a small amount of thermal energy. In contrast, as the number of carbon and hydrogen atoms increases, as in the case of ethanol and butanol, the decomposition reaction becomes more complex and thermal decomposition at low temperatures can become difficult.

[0045] Furthermore, since methanol is relatively easily decomposed into hydrogen and carbon monoxide, unreacted carbon is less likely to be generated. That is, it is possible to reduce the risk of clogging inside the pipe and a consequent decrease in the efficiency of the entire system due to the generation of unreacted carbon inside the pipe 3 ). From the above, methanol is the most preferable as an organic compound that can be easily thermally decomposed, and it becomes possible to maximize the utilization of the waste heat of the hydrogen utilization device 20 and generate sustainable energy.

[0046] As a non-limiting example in the hydrogen generation system 100 of the present disclosure, when the waste heat temperature of the hydrogen utilization device 20 is in the range of about 400 to about 600 °C, for example, under conditions where no catalyst is present, if the organic compound is butanol, thermal decomposition of butanol occurs at about 400 to about 600 °C, and hydrogen and carbon monoxide can be generated.

[0047] Also, as another example, when the organic compound is methanol, thermal decomposition occurs at about 300 to about 500 °C, and hydrogen and carbon monoxide can be generated. On the other hand, as described above, in the presence of a catalyst, the thermal decomposition temperature can be lowered compared to the case where no catalyst is present. As an example of the conditions where a catalyst is present, when the concentration of methanol is 30% by mass, at a temperature of about 300 °C, and the supply rate is 1 L / h, it is considered that theoretically more than about 400 L / h of hydrogen and more than about 200 L / h of carbon monoxide can be generated.

[0048] Thus, the thermal decomposition temperature differs depending on the type of organic compound, but it can change due to various factors such as the exhaust heat temperature of the hydrogen utilization device 20. Therefore, in designing region II of the piping 30, it is important to consider the exhaust heat temperature of the hydrogen utilization device 20, the thermal decomposition temperature of the organic compound, the supply rate, and the material of the piping 30 in order to optimize heat transfer from the outer surface to the interior of the piping 30. Specifically, setting the distance between the hydrogen utilization device 20 and the piping 30 and its length can contribute to improving reaction efficiency.

[0049] However, in the thermal decomposition process, it is preferable that the organic compound is completely decomposed to produce only hydrogen and carbon monoxide, but it is also possible that it is partially decomposed, resulting in the presence of unreacted organic compounds (e.g., methanol) in addition to hydrogen and carbon monoxide.

[0050] Through this process of organic compound movement and thermal decomposition, gaseous hydrogen and carbon monoxide are obtained from the organic compound. Therefore, in region I of pipe 30, only liquid organic compound may exist, but from near the outlet of region II to region III of pipe 30, only gas may exist. Alternatively, if the organic compound is partially thermally decomposed, a mixture of hydrogen and carbon monoxide gas and a mixture of liquid organic compound may coexist.

[0051] Furthermore, if an organic compound is supplied immediately after the hydrogen utilization device 20 starts operating, the exhaust heat temperature will be lower than the temperature at which the organic compound can be thermally decomposed, potentially generating impurities such as formaldehyde. These impurities can be generated in the initial stages before the organic compound is completely decomposed. However, as the exhaust heat temperature of the hydrogen utilization device 20 rises while passing through region II of the piping 30, the formaldehyde can be decomposed (to approximately 150°C) and converted into carbon monoxide. In this way, the proportion of hydrogen and carbon monoxide gases can be increased by promoting thermal decomposition.

[0052] Furthermore, as mentioned above, even if formaldehyde is not thermally decomposed, it can be radicalized and decomposed by passing through the discharge device 40 described later.

[0053] Through the above process, hydrogen can be produced by thermally decomposing the organic compound using the waste heat from the hydrogen utilization device 20.

[0054] However, since carbon monoxide is also produced along with hydrogen, it is necessary to separate the hydrogen and carbon monoxide. Therefore, the following will explain the arrangement of each component and device after region II of piping 30, the separation method using them, and the flow of materials.

[0055] As described above, one end of the piping 30 is connected to the first holding tank 10, but the other end extends to the vicinity of the bottom (or below) of the first holding tank 10, where the discharge device 40 is attached (see Figure 1). In other words, the discharge device 40 is placed in a solution of organic compound. This is because the discharge device 40 is intended to be used in the liquid of the organic compound held in the first holding tank 10. Therefore, it is preferable that the discharge device 40 is a liquid-based plasma discharge device that can be used in liquid.

[0056] By positioning the discharge device 40 near the bottom, the possibility of efficiently utilizing the discharge device 40 can be increased even if the liquid volume decreases due to the supply of organic matter. Specifically, it is preferable that the other end of the piping 30 extending into the first holding tank 10 and the discharge device 40 are located in the liquid organic compound. Furthermore, a recovery unit 50 for recovering hydrogen is provided in the first holding tank 10 above the discharge device 40. It is preferable that this recovery unit 50 is located in the liquid organic compound, for example, to avoid the inclusion of air.

[0057] The hydrogen and other substances (i.e., a mixed gas of hydrogen and carbon monoxide, or hydrogen, carbon monoxide, and undecomposed organic compounds) that have been thermally decomposed in region II of pipe 30 are moved through region III of pipe 30 using pump 61 and resupplied to the first holding tank 10. In other words, the hydrogen generation system 100 is a circulating system in which the organic compounds move from the first holding tank 10, are thermally decomposed, and then the generated mixed gas and other substances return to the first holding tank 10. Subsequently, the mixed gas of hydrogen and carbon monoxide that has moved through region III of pipe 30 passes through a discharge device 40 attached to the other end of pipe 30.

[0058] In this case, if the discharge device 40 is, for example, a plasma discharge device (particularly a liquid-immersion plasma discharge device), the mixed gas is converted into a plasma state, and carbon monoxide and hydrogen become excited. This excited carbon monoxide can react with organic compounds present around the discharge device 40 in the first holding tank 10 where the discharge device 40 and the recovery unit 50 are located, to produce acetic acid (see Figure 3).

[0059] Regarding the generation of acetic acid, we will describe in detail, as an example, the case in which the discharge device 40 is a liquid-immersion plasma discharge device and the organic compound is methanol.

[0060] First, a power supply 41 (for example, an AC power supply such as a DC power supply or a high-frequency power supply) is applied to the liquid-immersion plasma discharge device 40. When the power supply 41 is applied to the liquid-immersion plasma discharge device 40, a liquid-immersion plasma at a very high temperature of approximately 4000K is generated inside bubbles formed by heating such as electrolysis near the tip of the pipe 30.

[0061] In this liquid-phase plasma, carbon monoxide and hydrogen, which are continuously supplied mainly through the pipe 30, can have their molecular bonds broken by collisions with high-energy electrons. As a result, near the end of the pipe 30, carbon monoxide can be converted to CO* (excited state) or CO• (radical), and hydrogen can be converted to H* or H•. Thus, because the liquid-phase plasma is at a very high temperature, carbon monoxide and hydrogen can be converted to an excited state or a radical (or plasma) state instantaneously (in a few nanoseconds) without the use of a catalyst or under high temperature and high pressure conditions.

[0062] Here, the liquid plasma generated by the liquid plasma discharge device 40 is a non-equilibrium plasma localized inside the bubble formed near the tip of the pipe 30. This liquid plasma forms a reaction environment in which molecules present in the gas phase undergo direct collisions with high-energy electrons. In other words, the liquid plasma can create a non-equilibrium reaction environment in which a reaction in which carbon monoxide, in particular, preferentially transitions to an excited state becomes dominant.

[0063] Specifically, since the plasma in the liquid is localized near the tip of the pipe 30, in this discharge region, a reaction field is formed in which molecules among the supplied gas components that have the highest frequency of contact with high-energy electrons are preferentially excited and decomposed. Therefore, the degree of contact with electrons can correspond to the degree of excitation and decomposition by the plasma.

[0064] In the hydrogen generation system 100 of this disclosure, hydrogen and carbon monoxide are produced by thermal decomposition of methanol at low temperatures. Therefore, the produced hydrogen inevitably passes through the piping 30 in the process of being supplied to the hydrogen utilization device 20. In this hydrogen generation system 100 of this disclosure, in which carbon monoxide and hydrogen are continuously supplied to the piping 30, the excitation and decomposition reactions of carbon monoxide and hydrogen, which have the highest contact frequency with the high-energy electrons in the plasma generated by the liquid-immersion plasma discharge device 40, become the dominant main reactions.

[0065] On the other hand, methanol present in the liquid phase is located in the region outside the gaseous regions of carbon monoxide and hydrogen, resulting in a relatively low frequency of collisions with high-energy electrons in the liquid plasma. Furthermore, even if methanol excitation occurs, its excitation energy is easily diffused or deactivated rapidly through collisions with surrounding solvent molecules because it is in the liquid phase.

[0066] Therefore, in the reaction field formed by the liquid-phase plasma discharge device 40, carbon monoxide and hydrogen in the gas phase, which have a high frequency of contact with electrons, are excited and decomposed to a greater extent by the plasma, while organic compound sources such as methanol present in the liquid phase are decomposed to a relatively smaller extent by the plasma.

[0067] Thus, in a liquid-phase plasma, carbon monoxide and hydrogen are excited or partially decomposed by collisions with high-energy electrons, potentially generating highly reactive carbon-containing species and hydrogen radicals. On the other hand, methanol is present in the liquid phase and is relatively less decomposed by the plasma, so it is supplied to the reaction field while retaining its carbon skeleton.

[0068] As a result, a reaction pathway in which the highly reactive carbon-containing species derived from carbon monoxide combines with the carbon skeleton or substructure derived from methanol becomes relatively dominant, and acetic acid can be produced.

[0069] As described above, in the hydrogen generation system 100 of this disclosure, carbon monoxide is generated by thermal decomposition at low temperatures, and by intentionally supplying these gases, the production of acetic acid is promoted rather than the autodecomposition of methanol, thereby enabling efficient acquisition of acetic acid.

[0070] Furthermore, unlike conventional thermal reactions, the reaction using the liquid-phase plasma discharge apparatus 40 described above is extremely instantaneous, without the need for stepwise intermediate processes. In other words, acetic acid can be instantly produced from methanol and CO* (reactant species) on-site (in methanol solution).

[0071] On the other hand, excited hydrogen, although initially becoming atomic hydrogen (H), recombines within a very short time of a few nanoseconds to become molecular hydrogen (H). ２ ) is then recovered in a recovery unit 50 connected to the other end of the discharge device 40. Since the recovery unit 50 is installed above the discharge device 40, hydrogen, which has a low molecular weight and does not dissolve in water, can be efficiently accumulated in the recovery unit 50 by a method such as water displacement.

[0072] In this way, by using the discharge device 40, hydrogen can be separated from the mixed gas of hydrogen and carbon monoxide, and acetic acid can be easily produced from carbon monoxide and organic compounds (particularly methanol). By using the discharge device 40, it may be possible to produce acetic acid without requiring expensive catalysts such as rhodium or iridium, which are necessary in general acetic acid production processes. Therefore, the problem of catalyst deactivation does not occur, and long-term stable operation may be possible. Furthermore, when producing acetic acid using the above method, conditions such as high temperature and high pressure (for example, about 30 atmospheres, about 150-200°C) and pretreatment are not required. In other words, acetic acid can be produced at room temperature and atmospheric pressure (or normal pressure) in a simple process and with compact equipment, without using sealed containers, etc.

[0073] From the viewpoint of producing acetic acid from carbon monoxide, methanol is preferred as the organic compound because it has the shortest reaction pathway and the minimum energy loss.

[0074] Another advantage is that the discharge device 40 is used in a liquid with a high molecular density. Specifically, using the discharge device 40 in a liquid speeds up the process by which hydrogen and carbon monoxide become excited, which is one of the features that increases the efficiency of acetic acid production. Furthermore, by placing the discharge device 40 in a liquid, high-purity hydrogen can be generated without the introduction of air, and the hydrogen can be recovered in the recovery unit 50.

[0075] Next, as previously described, the hydrogen separated from carbon monoxide is collected in the recovery unit 50. For this purpose, the recovery unit 50 is sized to collect a certain amount of hydrogen, and can store hydrogen so that the hydrogen required by the hydrogen utilization device 20 can be stably supplied.

[0076] Through the above process, it becomes possible to thermally decompose organic compounds using the waste heat from the hydrogen utilization device 20, generate hydrogen, and accumulate it.

[0077] Next, the process of supplying hydrogen to the hydrogen utilization device 20, which uses the hydrogen collected in the recovery unit 50 as fuel, will be described. The hydrogen utilization device 20 may further include a second pipe 31 connecting the recovery unit 50 and the hydrogen utilization device 20 for supplying hydrogen, and a third pipe 32 for supplying outside air to the hydrogen utilization device 20.

[0078] Therefore, the hydrogen is supplied to the hydrogen utilization device 20 as needed via the second pipe 31 connected to the recovery unit 50. Note that before or immediately after the hydrogen utilization device 20 is driven, air may be trapped in the second pipe 31; therefore, a purge valve for releasing air may be provided in the second pipe 31.

[0079] In this way, hydrogen is supplied to the hydrogen utilization device 20 via the second pipe 31, enabling the hydrogen utilization device 20 to be driven by combustion. Since oxygen is essential in the combustion process, it is necessary to supply oxygen from the outside air. Outside air can be taken in through the third pipe 32 and supplied to the hydrogen utilization device 20. By providing the third pipe 32, oxygen is secured, the combustion process proceeds smoothly, and the hydrogen utilization device 20 can be driven stably. However, the third pipe 32 is for driving the hydrogen utilization device 20 and is not used in the pyrolysis process.

[0080] The hydrogen utilization device 20 may be, for example, a hydrogen engine for a vehicle or a hydrogen engine for a ship. In particular, if a ship's engine uses a conventional heavy oil-fueled engine, it can release a large amount of carbon dioxide into the ocean. Therefore, fuels using ammonia are also being researched to reduce carbon dioxide emissions. However, ammonia is highly toxic, and if ammonia leaks into the atmosphere, the vaporized ammonia gas can diffuse and have a significant impact on human life and the environment. Therefore, the above problem can be solved by using a hydrogen generation system 100 that can drive an engine with environmentally friendly hydrogen using highly safe organic compounds (for example, ethanol and methanol).

[0081] Through the process described above, the hydrogen generation system 100 can supply hydrogen generated from organic compounds supplied from the first holding tank 10 to drive the hydrogen utilization device 20. It also includes a process for producing acetic acid by utilizing the generated carbon monoxide. Thus, the hydrogen generation system 100 of this disclosure has a significant advantage over conventional technology in that it can produce beneficial substances without generating harmful substances.

[0082] One cycle of the hydrogen generation system 100 is completed when the supply of organic compounds to the first holding tank 10 ends. Specifically, as explained above, while organic compounds are held and supplied in the first holding tank 10, the generated hydrogen and carbon monoxide are resupplied, so acetic acid is continuously produced in the first holding tank 10. Consequently, as the concentration of acetic acid in the liquid increases, the concentration of organic compounds decreases relatively, and eventually, no organic compounds are supplied. As a result, the point at which hydrogen generation and supply can no longer be performed marks the completion of one cycle.

[0083] Once one cycle is complete, the first holding tank 10 holds a liquid whose main component is acetic acid. This acetic acid can be recovered by various methods and used for other purposes. Examples of recovery methods include pumping up the acetic acid using a pump, or converting it to sodium acetate by adding an alkaline agent such as sodium hydroxide and recovering the precipitate. It is also possible to recover the acetic acid using a so-called batch method, where the first holding tank 10 is replaced with another tank. The recovered acetic acid can be used in the production of products such as vinyl acetate, acetic acid esters, and cellulose acetate, and has a wide range of applications.

[0084] The hydrogen generation system 100 according to this disclosure can generate hydrogen at low temperatures (for example, about 200 to about 600°C) without generating carbon dioxide from organic compounds. A major feature is that the generated hydrogen can be supplied to drive the hydrogen utilization device 20, and acetic acid, an industrially important chemical substance, can also be obtained. If ethanol and methanol are used as the organic compounds, for example, they can be obtained relatively cheaply, thus providing excellent cost-effectiveness. Furthermore, commercially available methanol solutions can be used, and environmentally friendly raw materials such as biomethanol can also be used. This makes it possible to efficiently utilize resources while reducing the environmental impact. The recovery and utilization of acetic acid can contribute to sustainable industrial processes and can contribute to improved energy efficiency and cost reduction.

[0085] (Second Embodiment) The configuration of the hydrogen generation system 100A according to the second embodiment will be described below with reference to Figure 2. The second embodiment differs from the first embodiment in that it is equipped with a second holding tank 11, a buffer tank 70, and auxiliary fuel 80. Compared to the first embodiment, the second embodiment is provided with two holding tanks. The second holding tank 11 is a different tank from the first holding tank 10, and is used to separately hold the hydrogen and carbon monoxide produced from liquid organic compounds by thermal decomposition without returning them to the first holding tank 10. In other words, the second embodiment differs from the first embodiment in that the generated hydrogen and other gases are not returned to the first holding tank 10. Figure 2 is a schematic diagram showing the hydrogen generation system 100A according to the second embodiment of this disclosure.

[0086] The hydrogen generation system 100A according to the second embodiment of this disclosure may include a first holding tank 10, a hydrogen utilization device 20, a first pipe 30A, a second pipe 31A, a third pipe 32, a fourth pipe 33, a discharge device 40, a recovery unit 50, pumps 60, 61, a buffer tank 70, and auxiliary fuel 80. The components will be described in detail below.

[0087] (Second storage tank 11) The second storage tank 11 is preferably a highly airtight and corrosion-resistant container, similar to the first storage tank 10. It is also preferable to have a vent valve or the like, as organic compounds may volatilize. Furthermore, it is even more preferable to have insulation and a temperature control system that can withstand temperature fluctuations inside the tank. The material may be, for example, stainless steel and a tank with a corrosion-resistant coating.

[0088] (Buffer Tank 70) The buffer tank 70 is a high-pressure container for temporarily storing hydrogen produced from organic compounds, and is preferably airtight and corrosion-resistant. It is also preferable that it is equipped with an appropriate exhaust device such as a vent valve to prevent hydrogen leakage and contamination. Furthermore, it is even more preferable that it is equipped with insulation and a temperature control system to withstand fluctuations in pressure and temperature inside the tank, thereby enabling stable storage of hydrogen. The material may be stainless steel with excellent corrosion resistance, or a tank with a corrosion-resistant coating.

[0089] (Auxiliary fuel 80) Hydrogen is stored in the auxiliary fuel 80. For example, it is a fuel to supply hydrogen as needed when the amount of organic compounds decreases and the amount of hydrogen supplied decreases as the system operating time increases, or when the hydrogen utilization device 20 is first started up.

[0090] First, the differences in the arrangement of each device and equipment in the second embodiment compared to the first embodiment will be explained. Similar to the first embodiment, one end of the first pipe 30A is connected to the lower part of the first holding tank 10, but region III of the first pipe 30A extends downward toward the second holding tank 11, which is different from the first holding tank 10. In other words, unlike the first embodiment, the discharge device 40 and the recovery unit 50 are not provided in the first holding tank 10, while the discharge device 40 and the recovery unit 50 are located in the second holding tank 11.

[0091] In this case, gases such as hydrogen generated using the pump 61 can be moved. Furthermore, there is a second pipe 31A connecting the recovery unit 50 located in the second holding tank 11 and the hydrogen utilization device 20, and a buffer tank 70 for temporarily storing the generated hydrogen can be provided in the middle section of the second pipe 31A. In addition, there may be an auxiliary fuel 80 which is auxiliary hydrogen, and a valve is installed at the connection point between the fourth pipe 33 connected to the auxiliary fuel 80 and the second pipe 31A.

[0092] In other words, the second embodiment includes a first holding tank 10 for holding an organic compound, a first pipe 30A connected at one end to the first holding tank 10 and through which the organic compound can move, a discharge device 40 connected to the other end of the first pipe 30A, a recovery unit 50 for recovering hydrogen, and a second holding tank 11 different from the first holding tank, with the discharge device 40 and the recovery unit 50 located in the second holding tank 11.

[0093] The second holding tank 11, where the discharge device 40 and the recovery unit 50 are located, stores organic compounds similar to those stored in the first holding tank 10, filling at least one-third of the volume of the second holding tank 11. With this configuration, the waste heat from the hydrogen utilization device 20 can be used to excite a mixed gas of hydrogen and carbon monoxide (and possibly undecomposed organic compounds) that can be generated (thermally decomposed) from the organic compounds, via the discharge device 40.

[0094] As previously described, hydrogen can be separated from the mixed gas, and acetic acid can be produced by the reaction of excited carbon monoxide with the organic compound held in the second holding tank. In other words, it is possible to produce acetic acid by reacting the organic compound held in the second holding tank 11, where the discharge device 40 and the recovery unit 50 are located, with the carbon monoxide that can be produced from the organic compound held in the first holding tank 10. That is, the second holding tank 11 can be said to be a tank for producing acetic acid.

[0095] In this regard, in the first embodiment, since acetic acid was generated in the first holding tank 10 via the discharge device 40, a state in which organic compounds and acetic acid are mixed may occur. However, in the second embodiment, because there is a second holding tank 11, acetic acid is not generated in the first holding tank 10, and a state in which only organic compounds are stored can be maintained. As a result, even if organic compounds are continuously supplied from the first holding tank 10, the concentration of organic compounds in the first holding tank 10 cannot decrease, making it possible to stably secure the amount of hydrogen generated.

[0096] Next, the generated hydrogen is captured and collected in the recovery unit 50, temporarily stored in the buffer tank 70 via the second pipe 31A, and supplied to the hydrogen utilization device 20. This ensures a stable supply of hydrogen without interruption, in accordance with the amount of hydrogen generated. In particular, if the hydrogen utilization device 20 is a hydrogen engine, the engine repeatedly inhales and exhausts air, which can cause pulsation in the supplied hydrogen due to pressure fluctuations inside the engine. In this case, by providing the buffer tank 70, it is possible to mitigate these pressure fluctuations and maintain a more uniform flow rate of supplied hydrogen, thereby improving the overall efficiency of the hydrogen generation system 100A.

[0097] Furthermore, immediately after the hydrogen utilization device 20 is started up, it may not be able to thermally decompose organic compounds because the hydrogen utilization device 20 has not yet reached the temperature required for such decomposition. In this case, if hydrogen is stored in the buffer tank 70, it is possible to supply hydrogen from immediately after the hydrogen utilization device 20 is started up. Therefore, the startup time of the hydrogen utilization device 20 can be shortened, and stable operation can be achieved. As a result, improved overall system efficiency and earlier start of operation can be expected.

[0098] Generally, high pressure is required to efficiently store hydrogen in a tank. Therefore, if hydrogen produced from organic compounds is not used, a large-capacity, high-pressure tank is needed to store enough hydrogen to power the hydrogen utilization device 20. In contrast, the hydrogen generation system 100A is designed to supply hydrogen while generating it, so the buffer tank 70 does not need to be a large-capacity tank to store the amount needed to power the hydrogen utilization device 20. In other words, the required capacity and size of the buffer tank 70 are relatively small, as it only needs to store the amount needed immediately after the hydrogen utilization device 20 is started up. As a result, the hydrogen generation system 100A of this disclosure can improve the safety of the system and reduce the risks during handling and installation.

[0099] If no hydrogen is stored in the buffer tank 70, for example, hydrogen stored in the auxiliary fuel 80 is supplied via the connected fourth pipe 33 and second pipe 31A (region Y). At this time, the valve 90 provided between the fourth pipe 33 and the second pipe 31A is positioned so that region Y of the fourth pipe 33 and the second pipe 31A is opened, and region X of the second pipe 31A is closed.

[0100] While hydrogen is being supplied from the auxiliary fuel 80, when the hydrogen utilization device 20 reaches a temperature at which it can thermally decompose organic compounds, hydrogen is generated and accumulates in the buffer tank 70 and region X of the second piping 31A connected thereto. Subsequently, by switching the valve 90, the second piping 31A (regions X and Y) is opened and the fourth piping 33 is closed, thereby enabling the process of supplying hydrogen generated from organic compounds.

[0101] Furthermore, the second pipe 31A may be equipped with a flow meter and a sensor to detect it. For example, if hydrogen production and flow rate are unstable, the valve 90 may be switched to open both the fourth pipe 33 and the second pipe 31A as instructed by the sensor.

[0102] Furthermore, a supercharger may be installed in the second piping 31A. If the pressure of the generated hydrogen is insufficient, the supercharger can be used to increase the pressure of the hydrogen and supply it to the hydrogen utilization device 20. In other words, hydrogen can be utilized efficiently, making it possible to improve the performance of the hydrogen utilization device 20. As a result, it is expected that the reaction efficiency and operational stability of the entire hydrogen generation system 100A will be improved.

[0103] In some cases, the supercharger can make it easier to remove impurities, thereby increasing the purity of the hydrogen. Consequently, the reaction efficiency of the hydrogen utilization device 20 may be improved, and the output of the device may become more stable. Furthermore, since impurities are less likely to accumulate inside the hydrogen utilization device 20, the deterioration of the hydrogen utilization device 20's components may be reduced.

[0104] The embodiments described above represent typical examples. Those skilled in the art will readily understand that the disclosure is not limited thereto, and various other embodiments are conceivable without altering the essence of the disclosure.

[0105] Furthermore, the above-described embodiment of the present disclosure encompasses the following preferred embodiments: 1. A hydrogen generation system that generates hydrogen using waste heat from a hydrogen utilization device, wherein the waste heat causes thermal decomposition of an organic compound having carbon atoms, hydrogen atoms, and hydroxyl groups to generate hydrogen. 2. The hydrogen generation system in the 1st embodiment, capable of generating hydrogen from the organic compound in the absence of water and oxygen. 3. The hydrogen generation system in the 1st and 2nd embodiments, comprising piping through which the organic compound can move, wherein the piping is arranged adjacent to the outside of the hydrogen utilization device. 4. The hydrogen generation system in the 3rd embodiment, wherein the piping is provided such that the waste heat is transferred from the outer surface of the hydrogen utilization device to the organic compound inside the piping. 5. The hydrogen generation system in the 3rd or 4th embodiment, wherein the piping surrounds the hydrogen utilization device. 6. The hydrogen generation system in the 5th embodiment, wherein the portion of the piping surrounding the hydrogen utilization device is spiral. Seventh embodiment: A hydrogen generation system in which, in addition to generating hydrogen, carbon monoxide can be further generated from the organic compound, as in any of the first to sixth embodiments described above. Eighth embodiment: A hydrogen generation system in which carbon dioxide is not generated, as in any of the first to seventh embodiments described above. Ninth embodiment: A hydrogen generation system in which, as in any of the first to eighth embodiments described above, the system comprises a first holding tank for holding the organic compound, a pipe connected at one end to the first holding tank and through which the organic compound can move, a discharge device connected to the other end of the pipe, and a recovery unit for recovering the hydrogen, wherein the discharge device and the recovery unit are arranged in the first holding tank. A tenth embodiment: A hydrogen generation system comprising, in any of the first to eighth embodiments, a first holding tank for holding the organic compound, a pipe connected at one end to the first holding tank and through which the organic compound can move, a discharge device connected to the other end of the pipe, a recovery unit for recovering the hydrogen, and a second holding tank different from the first holding tank, wherein the discharge device and the recovery unit are arranged in the second holding tank.11th Embodiment: A hydrogen generation system further comprising a second pipe connecting the recovery unit and the hydrogen utilization device, as in the 9th Embodiment or the 10th Embodiment. 12th Embodiment: A hydrogen generation system, as in any of the 1st to 11th Embodiments, that enables the production of acetic acid from the organic compound held in the first or second holding tank, in which the discharge device and the recovery unit are arranged, and from carbon monoxide that can be produced from the organic compound. 13th Embodiment: A hydrogen generation system, as in any of the 10th to 12th Embodiments, further comprising a buffer tank for storing the hydrogen produced from the organic compound and auxiliary hydrogen. 14th Embodiment: A hydrogen generation system, as in any of the 9th to 13th Embodiments, in which the discharge device is placed in a solution of the organic compound held in the first or second holding tank. 15th Embodiment: A hydrogen generation system, as in any of the 9th to 14th Embodiments, in which the discharge device is a liquid-immersion plasma discharge device. 16th Embodiment: A hydrogen generation system capable of producing acetic acid from the organic compound held in the first or second holding tank and carbon monoxide that can be produced from the organic compound, under normal temperature and atmospheric pressure conditions, according to any of the first to 15 embodiments. 17th Embodiment: A hydrogen generation system capable of producing acetic acid in the absence of a catalyst, according to any of the first to 16 embodiments. 18th Embodiment: A hydrogen generation system in which the organic compound is an alcohol, according to any of the first to 17 embodiments. 19th Embodiment: A hydrogen generation system in which the organic compound is methanol, according to any of the first to 18 embodiments. 20th Embodiment: A hydrogen generation system in which the hydrogen utilization device is a hydrogen engine for ships or vehicles, a fuel cell, a hydrogen combustion boiler, a hydrogen turbine, a hydrogen power generation system, an ammonia synthesis device, a hydrogen burner, a gas appliance for hydrogen co-firing, or a hydrogen reduction furnace, according to any of the first to 19 embodiments. 21st aspect: A hydrogen generation system that generates hydrogen using waste heat from a hydrogen production apparatus, wherein the waste heat causes an organic compound having carbon atoms, hydrogen atoms, and hydroxyl groups to be thermally decomposed, thereby generating hydrogen.

[0106] 100: Hydrogen generation system 100A: Hydrogen generation system 10: First storage tank 11: Second storage tank 20: Hydrogen utilization device 30, 30A: First piping 31, 31A: Second piping 32: Third piping 33: Fourth piping 40: Discharge device 41: Power supply 50: Recovery unit 60, 61: Pump 70: Buffer tank 80: Auxiliary fuel 90: Valve P: Plasma

Claims

1. A hydrogen generation system that generates hydrogen using waste heat from a hydrogen utilization device, wherein the waste heat causes the thermal decomposition of an organic compound having carbon atoms, hydrogen atoms, and hydroxyl groups, thereby generating hydrogen.

2. The hydrogen generation system according to claim 1, which is capable of generating hydrogen from the organic compound in the absence of water and oxygen.

3. The hydrogen generation system according to claim 1, wherein the hydrogen generation system comprises piping through which the organic compound can move, and the piping is located adjacent to the outside of the hydrogen utilization device.

4. The hydrogen generation system according to claim 3, wherein the piping is provided such that the exhaust heat is transferred from the outer surface of the hydrogen utilization device to the organic compound inside the piping.

5. The hydrogen generation system according to claim 3, wherein the piping surrounds the hydrogen utilization device.

6. The hydrogen generation system according to claim 5, wherein the portion of the piping surrounding the hydrogen utilization device is spiral-shaped.

7. The hydrogen generation system according to claim 1, further capable of generating carbon monoxide from the organic compound in addition to generating hydrogen.

8. The hydrogen generation system according to claim 1, wherein no carbon dioxide is produced.

9. A hydrogen generation system according to claim 3, comprising: a first holding tank for holding the organic compound; a pipe connected at one end to the first holding tank and through which the organic compound can move; a discharge device connected to the other end of the pipe; and a recovery unit for recovering the hydrogen, wherein the discharge device and the recovery unit are arranged in the first holding tank.

10. The hydrogen generation system according to claim 3, comprising: a first holding tank for holding the organic compound; a pipe connected at one end to the first holding tank and through which the organic compound can move; a discharge device connected to the other end of the pipe; a recovery unit for recovering the hydrogen; and a second holding tank different from the first holding tank, wherein the discharge device and the recovery unit are arranged in the second holding tank.

11. The hydrogen generation system according to claim 9 or 10, further comprising a second pipe connecting the recovery unit and the hydrogen utilization device.

12. The hydrogen generation system according to claim 9 or 10, which enables the production of acetic acid from the organic compound held in the first or second holding tank in which the discharge device and the recovery unit are arranged, and from carbon monoxide that can be produced from the organic compound.

13. The hydrogen generation system according to claim 10, further comprising a buffer tank for storing the hydrogen generated from the organic compound and auxiliary hydrogen.

14. The hydrogen generation system according to claim 9 or 10, wherein the discharge device is placed in a solution of the organic compound held in the first holding tank or the second holding tank.

15. The hydrogen generation system according to claim 14, wherein the discharge device is a liquid plasma discharge device.

16. The hydrogen generation system according to claim 15, which is capable of producing acetic acid from the organic compound held in the first or second holding tank and carbon monoxide that can be produced from the organic compound, under normal temperature and atmospheric pressure conditions.

17. The hydrogen generation system according to claim 16, which is capable of producing acetic acid in the absence of a catalyst.

18. The hydrogen generation system according to claim 1, wherein the organic compound is an alcohol.

19. The hydrogen generation system according to claim 1, wherein the organic compound is methanol.

20. The hydrogen production system according to claim 1, wherein the hydrogen utilization device is a hydrogen engine for ships or vehicles, a fuel cell, a hydrogen combustion boiler, a hydrogen turbine, a hydrogen power generation system, an ammonia synthesis device, a hydrogen burner, a gas equipment compatible with hydrogen co-firing, or a hydrogen reduction furnace.

21. A hydrogen production system that generates hydrogen using waste heat from a hydrogen production apparatus, wherein the waste heat causes an organic compound having carbon atoms, hydrogen atoms, and hydroxyl groups to be thermally decomposed, thereby generating hydrogen.

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