Hydrogen production method and hydrogen production system

Abstract

According to exemplary embodiments of the present invention, a hydrogen production method and a hydrogen production system can be provided, the hydrogen production method optimizing ammonia decomposition conditions, thereby ensuring sufficient ammonia decomposition efficiency and preventing the occurrence of side reactions of a catalyst.

Description

Hydrogen production methods and hydrogen production systems

[0001] The present invention relates to a hydrogen production method and a hydrogen production system.

[0002] Ammonia (NH3) is used as an important chemical in various industrial fields. Recently, the utilization of ammonia as a hydrogen carrier is being actively researched.

[0003] Ammonia has a higher energy density than liquid hydrogen and can store approximately 1.7 times more hydrogen than liquid hydrogen in the same volume. In particular, liquid hydrogen must be transported and stored at ultra-low temperatures (approx. -253°C). In contrast, since ammonia liquefies easily at approximately -33°C under atmospheric pressure, it is much easier to store and transport compared to liquid hydrogen. Consequently, using ammonia can prevent increased facility costs for maintaining ultra-low temperatures and energy loss due to so-called boil-off.

[0004] In order to use hydrogen transported and stored using ammonia, a process of decomposing ammonia back into hydrogen is required. To produce hydrogen by decomposing ammonia, the following reaction equation is followed.

[0005] 2NH3↔ N2+ 3H2(Reaction Equation 1)

[0006] Ammonia decomposition according to Equation 1 can be carried out by various methods such as thermal decomposition, photodecomposition, plasma decomposition, or electrolysis. The ammonia decomposition reaction according to Equation 1 can reach thermal equilibrium at a temperature of approximately 500°C or higher at atmospheric pressure. A catalyst may be used to improve the reaction efficiency of this ammonia decomposition. However, as a nitriding atmosphere is formed due to ammonia decomposition, there was a problem of performance degradation caused by the nitriding of the catalyst.

[0007] (Patent Document 1) Korean Patent Publication No. 10-2024-0068674

[0008] The problem that the technical concept of the present invention aims to solve is to provide a hydrogen production method and a hydrogen production system capable of minimizing side reactions between a catalyst and ammonia.

[0009] The problems of the present invention are not limited to those described above. A person skilled in the art to which the present invention pertains will have no difficulty understanding additional problems of the present invention from the overall details of the specification.

[0010] According to exemplary embodiments for solving the problem of the present invention, a method for producing hydrogen is provided. The method for producing hydrogen comprises the step of producing hydrogen by contacting a source gas containing ammonia and hydrogen with reduced iron, wherein the supply rate of ammonia per mass of reduced iron is 1,000 to 8,000 mL g / g o •h, and the above raw gas contains, in mol%, ammonia: 15~60%, the remainder being hydrogen and unavoidable impurities.

[0011] The supply rate of the ammonia per mass of the reduced iron is 1,000 to 6,500 mL g / g o It can be h.

[0012] The above raw gas may contain, in mol%, ammonia: 20~50%, the remainder being hydrogen and unavoidable impurities.

[0013] The step of producing the above hydrogen can be performed at 700 to 900°C.

[0014] The above reduced iron is derived from one or more of a fluidized bed reduction furnace, a shaft furnace, a rotary kiln, and a combination thereof, and the temperature of the above reduced iron may be 500 to 1100°C.

[0015] The above hydrogen production method may further include the step of contacting the raw material gas with reduced iron, and then using the reduced iron to produce molten iron.

[0016] According to other exemplary embodiments of the present invention, a hydrogen production system is provided. The hydrogen production system comprises a hydrogen generating device configured to generate hydrogen by contacting reduced iron contained in an internal space with a source gas, wherein the source gas comprises, in molar percent, ammonia: 15 to 60%, the remainder being hydrogen and unavoidable impurities, and the supply rate of the ammonia per mass of the reduced iron is 1,000 to 8,000 mL g / g o It is h.

[0017] The above hydrogen production system may further include an ironmaking device configured to produce molten iron using the reduced iron of the hydrogen generation device.

[0018] The above hydrogen production system may further include a reduction furnace configured to reduce iron oxide to provide the reduced iron, and the reduction furnace may be characterized by reducing the iron oxide using hydrogen produced from the hydrogen generation device.

[0019] The above hydrogen generation device may include one or more of a fluidized bed reactor, a reaction tower, a moving bed reactor, a fixed bed reactor, a rotary kiln reactor, and a combination thereof.

[0020] According to exemplary embodiments of the present invention, by optimizing ammonia decomposition conditions, a hydrogen production method and a hydrogen production system can be provided that secure sufficient ammonia decomposition efficiency while preventing side reactions of the catalyst.

[0021] The various and beneficial advantages and effects of the present invention are not limited to those described above and will be more easily understood in the process of explaining specific embodiments of the present invention.

[0022] FIG. 1 is a drawing for illustrating a hydrogen production system according to exemplary embodiments.

[0023] FIG. 2 is a drawing for illustrating a hydrogen production system according to other exemplary embodiments.

[0024] FIG. 3 is a drawing for illustrating a hydrogen production system according to other exemplary embodiments.

[0025] FIG. 4 is a diagram showing the XRD analysis results according to Examples 1 to 3 and Comparative Examples 1 to 3.

[0026] FIG. 5 is a diagram showing the XRD analysis results according to Comparative Examples 4 to 9.

[0027] FIG. 6 is a diagram showing the XRD analysis results according to Comparative Examples 10 to 15.

[0028] FIG. 7 is a diagram showing the XRD analysis results according to Comparative Examples 16 to 21.

[0029] Figure 8 is a graph showing the results of the ammonia decomposition efficiency evaluation.

[0030] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe his invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention.

[0031] In the following descriptions with reference to the drawings, identical or corresponding components are assigned the same reference numerals, and redundant descriptions thereof will be omitted.

[0032] In the following embodiments, the terms first, second, etc. are used not in a limiting sense, but for the purpose of distinguishing one component from another component.

[0033] In the following embodiments, the singular expression includes the plural expression unless the context clearly indicates otherwise.

[0034] In the following embodiments, terms such as "include" or "have" mean that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components may be added.

[0035] In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, so the present invention is not necessarily limited to what is illustrated.

[0036] Where an embodiment can be implemented differently, a specific process sequence may be performed differently from the order described. For example, two processes described consecutively may be performed substantially simultaneously or proceed in the reverse order of the description.

[0037] In addition, in describing the present invention, if it is determined that a detailed description of related known components or functions may obscure the essence of the invention, such detailed description is omitted.

[0038] The present invention will be described in detail below through each embodiment. It should be noted that each embodiment described in this specification is not limited to a single embodiment but may also be combined with other embodiments. Accordingly, the citation of claims in the patent claims is merely an example of an embodiment, and the technical concept of the present invention should not be interpreted as being limited only to a combination with the cited claims; rather, combinations with various claims are also included within the scope of the technical concept of the present invention.

[0039] The present invention will be described in detail below through examples. However, it should be noted that the following examples are intended merely to illustrate and embody the present invention and are not intended to limit the scope of the present invention. This is because the scope of the present invention is determined by the matters described in the patent claims and matters reasonably inferred therefrom.

[0040] [Hydrogen Production Methods]

[0041] According to exemplary embodiments, a hydrogen production method may include a step of producing hydrogen by contacting reduced iron with a feedstock gas containing ammonia and a reducing gas. Thus, the present invention utilizes reduced iron as a catalyst for the ammonia decomposition reaction. Generally, precious metals such as ruthenium (Ru) or nickel (Ni) have been used as catalysts for hydrogen production. Although these have high catalytic activity, they are expensive and have limited reserves. Furthermore, large amounts of carbon dioxide are generated during the mining and extraction processes, resulting in a relatively high Global Warming Potential (GWP). In contrast, iron (Fe) is cheaper than precious metal or nickel catalysts, has abundant reserves, and has a low GWP. Therefore, there is a need to utilize iron as a catalyst for hydrogen production.

[0042] According to exemplary embodiments, reduced iron may be derived from a steelmaking process. More specifically, reduced iron may be derived from one or more of a fluidized bed reduction furnace, a shaft furnace, a rotary kiln, and a combination thereof. These facilities can provide reduced iron by reducing iron oxide of iron ore in a high-temperature reducing gas atmosphere. Thus, reduced iron derived from these facilities (steelmaking process) may contain high-temperature thermal energy. According to exemplary embodiments, the temperature of the reduced iron may be 500 to 1100°C. By utilizing such high-temperature reduced iron as a catalyst for the ammonia decomposition reaction, the ammonia decomposition efficiency can be increased. More preferably, in terms of improving ammonia decomposition efficiency, the temperature of the reduced iron may be 700 to 1000°C.

[0043] The source gas contains ammonia and hydrogen. When reduced iron is used as a catalyst, iron nitride may be formed during the ammonia decomposition process. In this case, as nitrogen atoms penetrate the lattice structure of the reduced iron, lattice distortion and internal stress may occur. Consequently, cracks and defects may develop in the reduced iron, reducing the number of catalytic active sites and potentially lowering the ammonia decomposition efficiency. Furthermore, the penetration of nitrogen may cause the reduced iron to become brittle, leading to particle breakage and potentially reducing the mechanical stability of the catalyst, which in turn shortens the catalyst's lifespan. Most importantly, after the catalytic reaction using reduced iron is completed, there is a concern that the catalyst may become difficult to regenerate due to the deep penetration of nitrogen into the reduced iron. However, according to exemplary embodiments, the formation of iron nitride during the ammonia decomposition process can be suppressed by including hydrogen in the source gas. This allows for an improved lifespan of the reduced iron and, consequently, contributes to an improved ammonia decomposition efficiency.

[0044] However, simply using a mixed gas containing ammonia and hydrogen as a raw material may make it difficult to effectively suppress the nitridation of reduced iron while simultaneously ensuring sufficient hydrogen production efficiency. Therefore, it is necessary to optimize the supply conditions and composition of the raw gas.

[0045] According to exemplary embodiments, the supply rate of ammonia per mass of reduced iron is 1,000 to 8,000 mL g / g o It can be ㆍh. The ammonia supply rate per mass of reduced iron is per unit catalyst mass (g o Ammonia injection amount per ) (mL) g It means ( / h). The ammonia supply rate per mass of reduced iron is 8000 mL g / g o If it exceeds ·h, it is necessary to excessively restrict the ammonia content of the source gas to inhibit the formation of iron nitride. In this case, hydrogen production efficiency may decrease. More preferably, in terms of inhibiting iron nitride formation and securing hydrogen production efficiency, the ammonia supply rate per mass of reduced iron is 6500 mL g / g o It may be less than ㆍh. More specifically, the ammonia supply rate per mass of reduced iron is 4000 mL g / g o It may be less than ㆍh. Meanwhile, the ammonia supply rate per mass of reduced iron is 1000 mL g / g o If the rate is less than 1 / h, it may cause a non-uniform temperature distribution within the reactor, leading to localized heating or cooling. In this case, the safety of the reactor may be compromised. Taking this into consideration, the ammonia supply rate per mass of reduced iron is 2000 mL g / g o It can be more than h.

[0046] According to exemplary embodiments, the raw gas may comprise, in mol%, 15 to 60% ammonia, the remainder hydrogen, and unavoidable impurities. By controlling the ammonia and hydrogen in the raw gas in such an appropriate ratio, it is possible to suppress the nitridation reaction of reduced iron while simultaneously ensuring sufficient hydrogen productivity. More preferably in terms of hydrogen productivity, the raw gas may comprise, in mol%, 20 to 50% ammonia, the remainder hydrogen, and unavoidable impurities. Unavoidable impurities refer collectively to impurities inevitably contained in the raw gas during the production or transport process, and may include, but are not particularly limited to, nitrogen, iron powder, and impurities deposited inside the reactor. Thus, by optimizing the supply conditions and composition of the raw gas, the present invention can ensure sufficient hydrogen productivity while simultaneously suppressing the nitridation reaction of reduced iron.

[0047] According to exemplary embodiments, the step of producing hydrogen can be performed at 700 to 900°C. If the temperature falls outside the lower limit of the above-described temperature range, the ammonia decomposition efficiency may be impaired. If the temperature falls outside the upper limit of the above-described temperature range, the stability of the reactor may be impaired. This temperature range can be maintained by heating the reactor in various ways, but the reaction temperature can be maintained more effectively by using reduced iron derived from the steelmaking process according to the exemplary embodiments.

[0048] According to exemplary embodiments, the hydrogen production method may further include the step of contacting a raw gas with reduced iron and then using the reduced iron to produce molten iron. If the supply conditions and composition of the raw gas are not controlled, the nitriding reaction of the reduced iron cannot be suppressed, making it difficult to recycle the reduced iron after the reaction. However, according to exemplary embodiments of the present invention, the purity of the reduced iron is maintained by sufficiently suppressing the nitriding reaction of the reduced iron during the ammonia decomposition process. As a result, it can be used as a raw material for the steelmaking process, thereby providing a hydrogen production method that can be integrated with the steelmaking process.

[0049] The production of molten iron is not particularly limited as long as reduced iron can be melted, but it can be carried out using an electric melting furnace.

[0050] [Hydrogen Production System]

[0051] FIG. 1 is a drawing for illustrating a hydrogen production system (10) according to exemplary embodiments.

[0052] Referring to FIG. 1, the hydrogen production system (10) includes a hydrogen generating device (100).

[0053] The hydrogen generating device (100) is configured to generate hydrogen by contacting reduced iron contained in an internal space with a raw gas. The hydrogen generating device (100) may be a reactor, a reactor, or a reaction tower that provides a predetermined reaction space so that the raw gas can properly contact the reduced iron.

[0054] According to exemplary embodiments, the hydrogen generation device (100) may include one or more of a fluidized bed reactor, a reaction tower, a moving bed reactor, a fixed bed reactor, a rotary kiln reactor, and a combination thereof. The fluidized bed reactor uses a raw material gas to evacuate reduced iron contained within to form a fluidized bed of reduced iron. This increases the contact efficiency between the raw material gas and the reduced iron, thereby increasing hydrogen productivity. Additionally, the reduced iron can be used as a catalyst without special processing, thus increasing production efficiency. The reaction tower can increase reaction efficiency by bringing the reduced iron moving vertically from top to bottom into countercurrent contact with the raw material gas rising upward. In this way, the fluidized bed reactor and the reaction tower can increase hydrogen productivity by ensuring sufficient contact between the raw material gas and the reduced iron. The combination of the fluidized bed reactor and the reaction tower is not particularly limited as long as sufficient contact between the reduced iron and the raw material gas is achieved, but it may be a facility in which the fluidized bed reactor and the reaction tower are connected sequentially.

[0055] According to exemplary embodiments, the source gas may comprise, in mol%, ammonia: 15–60%, the remainder being hydrogen and unavoidable impurities. Additionally, the supply rate of the ammonia per mass of reduced iron is 1000–8000 mL. g / g o It may be ㆍh. In this way, by controlling the supply conditions of the raw gas supplied to the hydrogen generation device (100), the formation of iron nitride can be suppressed and the lifespan of reduced iron can be extended. More specifically, in terms of suppressing the formation of iron nitride and securing hydrogen production efficiency, it is more preferable that the supply rate of ammonia per mass of reduced iron is 6500 mL g / g o It may be less than ㆍh. More specifically, the ammonia supply rate per mass of reduced iron is 4000 mL g / g o It may be less than ㆍh. Or, the ammonia supply rate per mass of reduced iron is 2000 mLg / g o It may be greater than 1. More preferably in terms of hydrogen productivity, the source gas may contain, in mol%, ammonia: 20-50%, the remainder being hydrogen and unavoidable impurities.

[0056] FIG. 2 is a drawing for illustrating a hydrogen production system (20) according to other exemplary embodiments.

[0057] Referring to FIG. 2, the hydrogen production system (20) may further include a steelmaking device (200) configured to produce molten iron using reduced iron from a hydrogen generating device (100). A conveying means may be installed between the hydrogen generating device (100) and the steelmaking device (200) so that the reduced iron from the hydrogen generating device (100) is supplied to the steelmaking device (200). The conveying means is not particularly limited, but may be implemented by an automated device such as a conveyor belt or by a worker directly conveying it.

[0058] The ironmaking device (200) is a device or facility that melts reduced iron to provide molten iron for steel production. When reduced iron is used as a catalyst for the ammonia decomposition reaction, a large amount of iron nitride may be produced. In the field of steel manufacturing, if a large amount of nitrogen is contained within the steel, it can lower the toughness of the steel and reduce steelmaking workability due to excessive denitrification. Therefore, during steel manufacturing, it is necessary to manage the process so that a large amount of nitrogen is not contained within the steel. According to exemplary embodiments, even though reduced iron is used as a catalyst for the ammonia decomposition reaction, it may substantially not contain iron nitride or may contain only a minute amount. Therefore, even if reduced iron is used as an ammonia catalyst, it can be used as a raw material for steel manufacturing, thereby further increasing manufacturing efficiency. In addition, hydrogen generated using reduced iron as a catalyst can be used to form a reducing atmosphere in the steel manufacturing process. As a result, energy efficiency can be increased during steel manufacturing.

[0059] FIG. 3 is a drawing for illustrating a hydrogen production system (30) according to other exemplary embodiments.

[0060] Referring to FIG. 3, the hydrogen production system (30) may further include a reduction furnace (300) configured to reduce iron oxide to provide reduced iron.

[0061] A conveying means may be installed between the hydrogen generating device (100) and the reduction furnace (300) so that the reduced iron of the reduction furnace (300) is supplied to the hydrogen generating device (100). The conveying means is not particularly limited, but may be implemented by an automated device such as a conveyor belt or by a worker directly conveying it.

[0062] The reduction furnace (300) can reduce iron oxide contained in the iron ore raw material supplied in a high-temperature reducing atmosphere into reduced iron. As a result, the reduced iron provided by the reduction furnace (300) contains high thermal energy, so it can provide the thermal energy required for ammonia decomposition as self-heat.

[0063] According to exemplary embodiments, the reduction furnace (300) can reduce iron oxide using hydrogen generated from the hydrogen generation device (100). In this way, the hydrogen production system (30) can supply the reduction gas required for the production of reduced iron, which is a material for steel production, on its own. In addition, since the reduction gas (hydrogen) can be supplied to the steelmaking process using ammonia, the generation of carbon dioxide in the steelmaking process can be reduced. As a result, it can contribute to achieving so-called green steel.

[0064] The amount of hydrogen supplied to the reduction furnace (300) from the hydrogen produced in the hydrogen generating device (100) is not particularly limited, as it can be appropriately adjusted according to the demand for reduction gas in the reduction furnace (300). As a non-limiting example, 1 to 100% of the hydrogen produced in the hydrogen generating device (100) may be supplied to the reduction furnace (300).

[0065] The reduction furnace (300) is not particularly limited as long as it is a device or facility capable of reducing iron oxide using a reducing gas. As a non-limiting example, the reduction furnace (300) may be one or more of a fluidized reduction furnace, a shaft furnace, a rotary kiln, and a combination thereof.

[0066] [Test Example]

[0067] Test Example 1: Iron Nitride Generation Test According to Ammonia Supply Rate

[0068] An experiment was conducted to determine whether iron nitride was generated depending on the ammonia supply rate. At this time, the reactor temperature was set to approximately 750°C and the reaction time was set to approximately 5 hours. The ammonia content and supply rate of the raw gas were set as shown below and in Table 1.

[0069] Separate ammonia supply rate (mL) g / g o ㆍh) Raw Gas Ammonia Content (mol%) Example 1: 3000 20 Example 2: 30 Example 3: 50 Comparative Example 1: 110 Comparative Example 2: 75 Comparative Example 3: 100 Comparative Example 4: 10000 10 Comparative Example 5: 20 Comparative Example 6: 30 Comparative Example 7: 50 Comparative Example 8: 75 Comparative Example 9: 100 Comparative Example 1: 30000 10 Comparative Example 1: 1120 Comparative Example 1: 1230 Comparative Example 1: 1350 Comparative Example 1: 1475 Comparative Example 15: 100 Comparative Example 16: 45000 10 Comparative Example 1: 1720 Comparative Example 1: 1830 Comparative Example 1: 1950 Comparative Example 2: 2075 Comparative Example 2: 1100

[0070] After the reaction was completed, X-ray diffraction (XRD) analysis was performed on each reduced iron used as a catalyst, using the Cu-Kα line as the target line.

[0071] FIG. 4 is a figure showing the XRD analysis results according to Examples 1 to 3 and Comparative Examples 1 to 3.

[0072] Figure 5 is a diagram showing the XRD analysis results according to Comparative Examples 4 to 9.

[0073] Figure 6 is a diagram showing the XRD analysis results according to Comparative Examples 10 to 15.

[0074] FIG. 7 is a diagram showing the XRD analysis results according to Comparative Examples 16 to 21.

[0075] Referring to FIGS. 4 to 7, the supply rate of the ammonia per mass of reduced iron is 8000 mL g / g o In Examples 1 to 3 and Comparative Example 1, which had a low ammonia content in the raw gas and a value of less than 1h, iron nitride (Fe4N) was not present.

[0076] However, the supply rate of the above ammonia per mass of reduced iron is 8000 mL g / g o Comparative Examples 4 to 21 exceeding ㆍh, and the supply rate of the ammonia per mass of reduced iron is 8000 mL g / g o Iron nitride appeared in Comparative Examples 2 and 3, which had a high ammonia content in the raw gas, although the ammonia content was less than or equal to h.

[0077] Test Example 2: Test of Ammonia Decomposition Efficiency According to Ammonia Content in Raw Gas

[0078] The ammonia decomposition efficiency of Examples 1 to 3 and Comparative Examples 1 to 3 of Table 1 above was measured. The component analysis of the gas generated at 30-minute intervals after the start of the reaction was performed, and the ammonia decomposition efficiency was evaluated by comparing it with the ammonia content introduced as the raw gas.

[0079] Figure 8 is a graph showing the results of the ammonia decomposition efficiency evaluation.

[0080] Referring to FIG. 8, Comparative Example 1 had the lowest ammonia decomposition efficiency. However, despite having a relatively low ammonia content, Examples 1 to 3 showed a decomposition efficiency similar to that of Comparative Examples 2 and 3, which had a relatively high ammonia content.

[0081] From the above tests, it was confirmed that by controlling the ammonia supply rate and the ammonia content in the raw gas, sufficient ammonia decomposition efficiency can be secured while simultaneously suppressing the nitration of reduced iron.

[0082] Although the invention has been described with reference to the above embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as described in the following claims.

[0083] (Explanation of symbols)

[0084] 10, 20, 30: Hydrogen production system

[0085] 100: Hydrogen generator

[0086] 200: Ironmaking device

[0087] 300: Reduction furnace

Claims

1. A method comprising the step of producing hydrogen by contacting a source gas containing ammonia and hydrogen with reduced iron, wherein The supply rate of the ammonia per mass of the reduced iron is 1,000 to 8,000 mL g / g o ㆍh and, A method for producing hydrogen using the above raw gas, comprising, in mol%, ammonia: 15~60%, the remainder being hydrogen and unavoidable impurities.

2. In Paragraph 1, The supply rate of the ammonia per mass of the reduced iron is 1,000 to 6,500 mL g / g o ㆍh hydrogen production method.

3. In Paragraph 1, A method for producing hydrogen using the above raw gas, comprising, in mol%, ammonia: 20~50%, the remainder being hydrogen and unavoidable impurities.

4. In Paragraph 1, The step of producing the above hydrogen is a hydrogen production method performed at 700 to 900°C.

5. In Paragraph 1, The above reduced iron is derived from one or more of a fluidized bed reduction furnace, a shaft furnace, a rotary kiln, and a combination thereof, and A hydrogen production method in which the temperature of the above-mentioned reduced iron is 500~1100℃.

6. In Paragraph 1, The above hydrogen production method is, A method for producing hydrogen, further comprising the step of contacting the above raw material gas with reduced iron, and then using the reduced iron to produce molten iron.

7. A hydrogen generating device configured to generate hydrogen by contacting reduced iron contained in an internal space with a raw gas; comprising, The above raw gas comprises, in mol%, ammonia: 15–60%, the remainder being hydrogen and unavoidable impurities, and The supply rate of the ammonia per mass of the reduced iron is 1,000 to 8,000 mL g / g o ㆍh hydrogen production system.

8. In Paragraph 7, The above hydrogen production system is, A hydrogen production system further comprising a steelmaking device configured to produce molten iron using the reduced iron of the hydrogen generation device.

9. In Paragraph 7, The above hydrogen production system is, It further includes a reduction furnace configured to reduce iron oxide to provide the reduced iron, and A hydrogen production system characterized by the above-mentioned reduction furnace reducing the iron oxide using hydrogen produced from the above-mentioned hydrogen generation device.

10. In Paragraph 7, The above hydrogen generation device is, A hydrogen production system comprising one or more of a fluidized bed reactor, a reaction tower, a moving bed reactor, a fixed bed reactor, a rotary kiln reactor, and a combination thereof.

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