Hydrogen production system and hydrogen production method

Abstract

According to exemplary embodiments of the present invention, a hydrogen production system is provided. The hydrogen production system comprises: a dry quenching facility configured to cool coke using a cooling gas; a boiler configured to receive the cooling gas from the dry quenching facility and recover heat energy of the cooling gas to produce first steam and electric power; and a water electrolysis facility configured to receive the electric power from the boiler and electrolyze second steam to produce hydrogen. According to other exemplary embodiments of the present invention, a method for producing hydrogen is provided.

Description

Hydrogen production system and hydrogen production method

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

[0002] More specifically, the present invention relates to a hydrogen production system linked to a steel mill.

[0003] Recently, with growing concern about global warming, research into technologies that can reduce CO2 emissions is ongoing. In particular, interest in hydrogen, a material capable of stable, large-scale, long-term energy storage, is growing.

[0004] Hydrogen can be produced by decomposing hydrogen-containing raw materials, such as water (water vapor) electrolysis or ammonia thermal decomposition. However, water electrolysis requires a significant amount of electrical energy, which reduces the overall energy efficiency of the hydrogen production system.

[0005] From the above, it can be said that research is needed on a hydrogen production system that can independently produce the electricity needed to produce hydrogen.

[0006] (Patent Document 1) Japanese Patent Publication No. 2006-307290.

[0007] The technical idea of ​​the present invention aims to solve a problem by providing a hydrogen production system and a hydrogen production method that can independently supply electricity.

[0008] The subject matter of the present invention is not limited to the above-described content. Those skilled in the art will have no difficulty understanding the additional subject matter of the present invention from the overall description of the present invention.

[0009] According to exemplary embodiments of the present invention, a hydrogen production system is provided. The hydrogen production system includes a dry digestion facility configured to cool coke using a cooling gas; a boiler configured to receive the cooling gas from the dry digestion facility and recover the thermal energy of the cooling gas to produce first steam and electric power; and a water electrolysis facility configured to receive the electric power from the boiler and electrolyze second steam to produce hydrogen.

[0010] The above hydrogen production system may be configured so that the cooling gas from which heat energy has been recovered in the boiler is circulated to the dry digestion facility.

[0011] The temperature of the cooling gas supplied to the boiler may be 900°C or higher, and the temperature of the cooling gas circulated to the dry digestion facility may be 200°C or lower.

[0012] The above first steam may be characterized in that it is not provided to the water electrolysis facility.

[0013] The dry extinguishing facility comprises a cooling chamber configured to cool the coke; and a pre-chamber continuously connected to the cooling chamber at an upper portion of the cooling chamber, wherein the boiler can be fluidly connected to the pre-chamber.

[0014] The above electrolysis facility includes a electrolysis unit cell, and the electrolysis unit cell includes a fuel electrode that receives second steam, an air electrode that generates a product gas containing hydrogen or oxygen, and an electrolyte disposed between the fuel electrode and the air electrode, and the electrolyte may include any one of a solid ceramic electrolyte, a polymer electrolyte membrane, an anion exchange membrane, and a combination thereof.

[0015] The above boiler can be configured to produce 10 MW or more of electric power based on a supply amount (ton / hr) of 80 tons / hr of coke fed into the dry digestion facility.

[0016]

[0017] According to other exemplary embodiments of the present invention, a method for producing hydrogen is provided. The method for producing hydrogen is linked to an iron and steel manufacturing process, and may include the steps of: providing power produced in a boiler to a water electrolysis facility using high-temperature cooling gas obtained by dry cooling coke; and supplying secondary steam to the water electrolysis facility, thereby producing hydrogen from the secondary steam.

[0018] The above-mentioned power and first steam are produced using the above-mentioned high-temperature cooling gas in the above-mentioned boiler, and the above-mentioned first steam may not be supplied to the above-mentioned water electrolysis facility.

[0019] The above coke can be cooled using the cooling gas in a dry quenching facility fluidly connected to the boiler.

[0020] The above boiler can be configured to produce 10 MW or more of electric power based on a supply amount (ton / hr) of 80 tons / hr of coke fed into the dry digestion facility.

[0021] According to exemplary embodiments of the present invention, a hydrogen production system and a hydrogen production method capable of supplying power on their own can be provided.

[0022] The various advantageous and beneficial effects of the present invention are not limited to the above-described contents, and will be more easily understood in the course of explaining specific embodiments of the present invention.

[0023] FIG. 1 is a drawing for explaining a hydrogen production system according to exemplary embodiments.

[0024] Figure 2 is a drawing for explaining a dry digestion facility.

[0025] Figure 3 is a drawing for explaining a boiler.

[0026] Figure 4 is a drawing for explaining a water electrolysis unit cell.

[0027] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0028] Hereinafter, when explaining with reference to drawings, identical or corresponding components are given the same drawing reference numerals and redundant descriptions thereof are omitted.

[0029] In the examples below, the terms first, second, etc. are not used in a limiting sense, but are used for the purpose of distinguishing one component from another.

[0030] In the examples below, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0031] In the examples below, terms such as “include” or “have” mean that a feature or component described in the specification is present, and do not preclude the possibility that one or more other features or components may be added.

[0032] For convenience of explanation, the sizes of components in the drawings may be exaggerated or reduced. For example, the sizes and thicknesses of each component shown in the drawings are arbitrarily indicated for convenience of explanation, and thus the present invention is not necessarily limited to what is shown.

[0033] In some embodiments, where implementations are otherwise feasible, specific process sequences may be performed in a different order than described. For example, two processes described in succession may be performed substantially simultaneously, or in a reverse order from the described order.

[0034] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0035]

[0036] FIG. 1 is a drawing for explaining a hydrogen production system (10) according to exemplary embodiments.

[0037] Referring to FIG. 1, a hydrogen production system (10) according to exemplary embodiments includes a dry digestion facility (100), a boiler (200), and a water electrolysis facility (300).

[0038] The dry quenching facility (100) may be configured to cool coke using cooling gas. In this way, according to exemplary embodiments, a hydrogen production system linked to a steelmaking process may be provided.

[0039] Blast furnace coke, typically used in the steelmaking process, is produced by introducing mixed coal into a coke oven, drying it at temperatures exceeding 1,000°C for approximately 20 hours, and then discharging and cooling the high-temperature, red-hot coke. This coke, along with sintered ore, is then fed into the blast furnace to serve as a heat source and reducing agent for the production of pig iron. The high-temperature, red-hot coke discharged after drying in this coke manufacturing process has a high temperature of over 1,000°C, requiring either wet or dry cooling methods for cooling.

[0040] In this case, wet cooling methods not only make it difficult to recover high-temperature sensible heat, but can also cause environmental problems such as the generation of large amounts of wastewater and dust. However, according to exemplary embodiments, the aforementioned problems can be prevented by using a dry cooling method.

[0041] Figure 2 is a drawing for explaining a dry digestion facility (100).

[0042] Referring to FIG. 2, the dry digestion facility (100) may include a cooling chamber (110) and a pre-chamber (120).

[0043] The cooling chamber (110) may be located at the bottom of the dry extinguishing facility (100). Coke may be supplied from the top of the dry extinguishing facility (100) and flow toward the cooling chamber (110).

[0044] The cooling chamber (110) may be configured to cool coke supplied to the dry extinguishing system (100). To this end, the cooling chamber (110) may accommodate cooling gas supplied from the outside. More specifically, the cooling gas may be supplied to the lower portion of the cooling chamber (110) so that it can contact the coke in a countercurrent direction. This improves the contact efficiency with the coke, thereby effectively cooling the coke.

[0045] The coke flowing into the cooling chamber (110) may contain thermal energy at a temperature of about 1000°C or higher. These high-temperature cokes may be cooled to about 150°C or lower by contacting and exchanging heat with the cooling gas flowing from the bottom to the top of the cooling chamber (110). As a result, the cooling gas may be heated to a temperature of about 900°C or higher. The heated cooling gas may be captured in the pre-chamber (120).

[0046] The cooling gas may comprise an inert gas. More specifically, the cooling gas may be an inert gas containing 70 to 75% by volume of nitrogen (N2).

[0047] The coke cooled in the cooling chamber (110) can be discharged to the lower part of the cooling chamber (110).

[0048] The pre-chamber (120) can be continuously connected to the cooling chamber (110) at the upper portion of the cooling chamber (110). Coke can be provided to the upper portion of the pre-chamber (120). More specifically, the red-hot coke that has completed dry distillation can be loaded into the pre-chamber (120) by a crane (not shown) in a bucket (not shown) mounted on a transport cart (not shown). The red-hot coke can be loaded by dropping into the pre-chamber (120) through an inlet (121) provided at the upper portion of the pre-chamber (120). Thereafter, the coke can flow into the cooling chamber (110) and be cooled by the cooling gas. The cooling gas that has cooled the coke can rise toward the pre-chamber (120) and flow to the upper portion of the dry extinguishing equipment (100).

[0049] Figure 3 is a drawing for explaining a boiler (200).

[0050] Referring to FIG. 3, the boiler (200) can receive cooling gas from the dry extinguishing system (100). For this purpose, the boiler (200) can be connected to the dry extinguishing system (100) via a fluid connection means, such as an air duct (not shown). More specifically, the boiler (200) can be connected to a pre-chamber (120). As a result, the boiler (200) can receive cooling gas containing high-temperature thermal energy after heat exchange with coke.

[0051] According to exemplary embodiments, the boiler (200) may be configured to recover thermal energy of a cooling gas to produce first steam and electric power. More specifically, the boiler (200) may include a cooling gas pipe (210) configured to allow cooling gas to flow, a heat exchange pipe (220) disposed adjacent to the cooling gas pipe, a water storage tank (230) that provides water to the heat exchange pipe (220), and a generator (240) that receives first steam from the heat exchange pipe (220) to operate a turbine and produce electric power.

[0052] The cooling gas pipe (210) may be fluidly connected to the dry extinguishing device (100). More specifically, the cooling gas pipe (210) may be fluidly connected to the pre-chamber (120). To this end, the cooling gas pipe (210) may be connected to the dry extinguishing device (100) through a fluid connection means such as an air duct.

[0053] According to exemplary embodiments, the cooling gas from which heat energy has been recovered in the boiler (200) may be circulated to the dry digestion facility (100). More specifically, the cooling gas from which heat energy has been recovered in the boiler (200) may be circulated to the cooling chamber (110). In this way, the cooling gas may be circulated within the hydrogen production system (10), thereby improving the dry digestion efficiency of coke.

[0054] According to exemplary embodiments, the boiler (200) may be configured to produce 10 MW or more of power based on a supply amount (ton / hr) of 80 tons / hr of coke fed into the dry digestion facility (100). As the supply amount of coke fed into the dry digestion facility (100) increases, the amount of cooling gas that exchanges heat with the coke in the cooling chamber (110) may increase. As the amount of cooling gas containing such high-temperature thermal energy increases, the amount of first steam produced through heat exchange with the cooling gas in the boiler (200) may increase. As the amount of first steam increases, higher power can be provided to the turbine of the generator (240), and thus higher power can be produced from the generator (240).

[0055] The heat exchange pipe (220) may be positioned adjacent to the cooling gas pipe (210) so as to exchange heat with the cooling gas pipe (210). More specifically, the heat exchange pipe (220) may be in partial or full contact with the cooling gas pipe (210).

[0056] One end (220a) of the heat exchange pipe (220) may be connected to a water storage tank (230), and the other end (220b) opposite to the one end (220a) may be connected to a generator (240). Water may flow through one end (220a) of the heat exchange pipe (220). The water may flow to the other end (220b) and be provided as first steam through heat exchange with a cooling gas. The first steam may be provided to the generator (240) through the other end (220b) of the heat exchange pipe (220).

[0057] The fluid (water and first steam) within the heat exchange pipe (220) can flow in parallel, countercurrent, or a combination thereof with respect to the flow direction of the cooling gas within the cooling gas pipe (210).

[0058] According to exemplary embodiments, the temperature of the cooling gas supplied to the boiler (200) may be about 900°C or higher. The temperature of the cooling gas circulated to the dry digestion facility (100) may be about 200°C or lower. The maximum production amount of the first steam may be determined by the thermal energy according to the difference between the supply temperature and the circulation temperature of the cooling gas. That is, the greater the temperature difference between the cooling gas supplied to the boiler (200) and the cooling gas circulated to the dry digestion facility (100), the greater the production amount of the first steam may be.

[0059] As a non-limiting example, the difference between the supply temperature and the circulation temperature of the cooling gas may be determined by any one of the heat exchange areas of the cooling gas pipe (210) and the heat exchange pipe (220), the materials of the cooling gas pipe (210) and the heat exchange pipe (220), the flow rate of the cooling gas within the cooling gas pipe (210), the flow rate of water within the heat exchange pipe (220), and a combination thereof.

[0060] The generator (240) is connected to the heat exchange pipe (220) and can receive first steam. The turbine included in the generator (240) rotates due to the flow of the first steam, and the generator (240) can produce electricity using the power of the turbine. The first steam that operates the turbine can be discharged to the outside of the hydrogen production system (10). Alternatively, the first steam that operates the turbine can be circulated to the storage tank (230). In this case, the first steam can be cooled during the process of being transported to the storage tank (230) and stored as water in the storage tank (230).

[0061] The electrolysis facility (300) may be configured to receive power from the boiler (200) and electrolyze secondary steam to produce hydrogen. In this way, the hydrogen production system (10) can independently supply power, thereby efficiently producing hydrogen.

[0062] The second steam may be distinct from the first steam produced in the boiler (200). For a more specific example, the first steam may not be provided to the electrolysis facility (300). The first steam may provide motive energy for rotating the turbine of the generator (240). If some of the first steam produced is branched and provided to the electrolysis facility (300) and the remainder is provided to the generator (240), the amount of the first steam provided to the generator (240) may decrease, thereby lowering the power generation efficiency of the generator (240). Alternatively, even if the generator (240) and the electrolysis facility (300) are sequentially connected to drive the turbine and supply the first steam to the electrolysis facility (300), the flow path of the first steam may become excessively long. Due to this, the pipelines and pumps, etc., that transport the first steam to the electrolysis facility (300) may be excessively extended, resulting in excessive costs for the maintenance and management of the hydrogen production system (10). Therefore, by producing hydrogen using a second steam separate from the first steam, the power generation efficiency of the boiler (200) can be improved and the maintenance and management of the hydrogen production system (10) can be easily performed.

[0063] As a non-limiting example, hydrogen produced in the electrolysis facility (300) can be provided to the iron ore reduction process of the iron ore manufacturing process. Conventionally, coke was manufactured using coal, and this coke was used in the iron ore reduction process. This resulted in a problem of increased carbon dioxide emissions derived from the raw material of the coke. However, according to exemplary embodiments, since hydrogen can be used as a reducing agent for iron ore, the amount of carbon dioxide generated in the iron ore manufacturing process can be effectively reduced.

[0064] Figure 4 is a drawing for explaining a water electrolysis unit cell (30).

[0065] Referring to FIG. 4, the electrolysis equipment (300) may include electrolysis unit cells (30). More specifically, the electrolysis equipment (300) may be provided in the form of a electrolysis stack in which a plurality of electrolysis unit cells (30) are stacked. In addition, the electrolysis equipment (300) may further include heating means capable of heating the second steam to the operating temperature of the electrolysis unit cells (30). In this case, the heating means may be any one of an electric heater, a heat exchanger, and a combination thereof.

[0066] The electrolysis unit cell (30) can generate electricity by electrolyzing moisture contained in the second steam. At this time, the electrolysis reaction of moisture is an endothermic reaction, but some heat may be generated by the electrochemical irreversible reaction occurring in the second steam. The amount of heat absorbed by the electrolysis of moisture in the electrolysis unit cell (30) and the amount of heat generated by the electrochemical irreversible reaction can be determined according to the operating voltage of the electrolysis unit cell (30).

[0067] According to exemplary embodiments, the operating voltage of the water electrolysis unit cell (30) may be set in a range in which the amount of heat generated by the electrochemical irreversible reaction of the water electrolysis unit cell (30) is greater than or equal to the amount of heat absorbed by the endothermic reaction of the water electrolysis unit cell (30). That is, the operating voltage of the water electrolysis unit cell (30) may be greater than or equal to the so-called thermoneutral voltage, in which the amount of heat generated by the electrochemical irreversible reaction of the water electrolysis unit cell (30) is substantially equal to the amount of heat absorbed by the endothermic reaction of the water electrolysis unit cell (30). Accordingly, the water electrolysis unit cell (30) can maintain a temperature required for the electroreaction of water by using its own thermal energy.

[0068] The electrolysis unit cell (30) may include a fuel electrode (31) that receives second steam, an air electrode (32) that generates a product gas containing hydrogen or oxygen, and an electrolyte (33) that is placed between the fuel electrode (31) and the air electrode (32).

[0069] Second steam may be provided to the fuel electrode (31). Moisture contained in the second steam may be electrolyzed at the fuel electrode (31). As a result, a reaction gas containing hydrogen or oxygen may be generated at the fuel electrode (31). The type of gas contained in the reaction gas may be different from the product gas. As one example, when the reaction gas contains oxygen, the product gas may contain hydrogen. As another example, when the reaction gas contains hydrogen, the product gas may contain oxygen.

[0070] As a non-limiting example, the air electrode (32) may be supplied with a carrier gas to effectively discharge the generated gas. The carrier gas may flow in one direction in the air electrode (32) and discharge the generated gas generated in the air electrode (32) to the outside of the electrolysis unit cell (30). However, for convenience of illustration, FIG. 4 illustrates a case where the carrier gas is not supplied. Therefore, a person skilled in the art will be able to appropriately design and modify the air electrode of the electrolysis unit cell to supply the carrier gas.

[0071] Depending on the type of electrolyte (33), the ion behavior within the electrolysis unit cell (30) may be different. As an example, water contained in the second water vapor in the fuel electrode (31) is electrolyzed to produce oxygen gas and hydrogen ions (H + ) can be generated. These hydrogen ions can be provided to the air electrode (32) through the electrolyte (33) to generate a product gas containing hydrogen. As another example, water contained in the second water vapor is electrolyzed at the fuel electrode (31) to generate hydrogen gas and oxygen ions (O 2-) can be generated. These oxygen ions can be provided to the cathode (32) through the electrolyte (33) to generate a product gas containing oxygen. As another example, water contained in the second steam at the fuel electrode (31) can be electrolyzed to generate hydroxide ions (OH-) and hydrogen gas. These hydroxide ions can be provided to the cathode (32) through the electrolyte (33) to generate a product gas containing oxygen. In this way, hydrogen can be included in the product gas or reaction gas discharged from the water electrolysis unit cell (30). The generated hydrogen can be captured separately and provided as a reducing agent in the iron making process.

[0072] As a non-limiting example, the electrolyte (33) may include any one of a solid ceramic electrolyte, a polymer electrolyte membrane, an anion exchange membrane, and combinations thereof.

[0073]

[0074] [Hydrogen production method]

[0075] A method for producing hydrogen according to exemplary embodiments may include a step of providing power produced in a steelmaking process to a water electrolysis facility, and a step of supplying second steam to the water electrolysis facility to produce hydrogen.

[0076]

[0077] The step of providing the electricity produced in the steelmaking process to the electrolysis facility can be performed using the so-called coke dry quenching method, which cools the red-hot coke with an inert gas. More specifically, the red-hot coke can be cooled using a cooling gas in a dry quenching facility that is fluidly connected to the boiler and cools the red-hot coke using the coke dry quenching method. Thereafter, the high-temperature cooling gas that has exchanged heat with the red-hot coke can be used to produce primary steam and electric power in the boiler. The electrolysis facility can be operated by providing the electric power produced in the boiler to the electrolysis facility. The boiler can be configured to produce 10 MW or more of electric power based on a supply amount (ton / hr) of 80 tons / hr of coke fed to the dry quenching facility. In this case, the primary steam may not be supplied to the electrolysis facility. In addition, since any overlapping matters with the above-described hydrogen production system (10) can be equally applied to the hydrogen production method, a detailed description thereof will be omitted.

[0078]

[0079] The step of producing hydrogen by supplying secondary steam to the electrolysis facility can be performed by supplying secondary steam, which is distinct from the primary steam, to the electrolysis facility and electrolyzing the secondary steam. In this way, the efficiency of the hydrogen production method can be further improved by producing hydrogen using the independent secondary steam rather than the primary steam derived from the iron and steel manufacturing process. In addition, since the overlapping matters with the above-described hydrogen production system (10) can be equally applied to the hydrogen production method, a detailed description thereof will be omitted.

[0080]

[0081] The present invention has been described in more detail through drawings and examples. However, the configurations described in the drawings or examples described in this specification are merely embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as of the time of this application.

[0082] (Explanation of symbols)

[0083] 10: Hydrogen production system 230: Water storage tank

[0084] 100: Dry fire extinguishing equipment 240: Generator

[0085] 110: Cooling chamber 300: Water electrolysis facility

[0086] 120: Free chamber 30: Electrolysis unit cell

[0087] 200: Boiler 31: Fuel electrode

[0088] 210: Cooling gas pipe 32: Air electrode

[0089] 220: Heat exchange pipe 33: Electrolyte

Claims

1. Dry quenching plant configured to cool coke using cooling gas; A boiler configured to receive the cooling gas from the dry digestion facility and to recover the heat energy of the cooling gas to produce first steam and electric power; and A hydrogen production system including a water electrolysis facility configured to receive the electric power from the boiler and electrolyze second steam to produce hydrogen.

2. In paragraph 1, The above hydrogen production system, A hydrogen production system configured to circulate the cooling gas from which heat energy is recovered in the above boiler to the above dry digestion facility.

3. In paragraph 2, The temperature of the cooling gas supplied to the above boiler is 900℃ or higher, A hydrogen production system in which the temperature of the cooling gas circulating through the dry digestion facility is 200°C or less.

4. In paragraph 1, A hydrogen production system, characterized in that the first steam is not provided to the water electrolysis facility.

5. In paragraph 1, The above dry extinguishing equipment is, a cooling chamber configured to cool the coke; and Including a pre-chamber continuously connected with the cooling chamber at the upper portion of the cooling chamber, The above boiler is a hydrogen production system fluidly connected to the above pre-chamber.

6. In paragraph 1, The above electrolysis equipment includes a electrolysis unit cell, The electrolysis unit cell comprises a fuel electrode that receives second steam, an air electrode that generates a product gas containing hydrogen or oxygen, and an electrolyte disposed between the fuel electrode and the air electrode. A hydrogen production system wherein the electrolyte comprises any one of a solid ceramic electrolyte, a polymer electrolyte membrane, an anion exchange membrane, and a combination thereof.

7. In paragraph 1, The above boiler, A hydrogen production system configured to produce 10MW or more of electricity based on a supply amount (ton / hr) of 80ton / hr of coke fed into the above dry digestion facility.

8. A method of producing hydrogen linked to the ironmaking process, A step of providing electric power produced in a boiler to an electrolysis facility by using high-temperature cooling gas obtained by dry cooling coke; and A hydrogen production method comprising a step of supplying second steam to the above-mentioned electrolysis facility and producing hydrogen from the second steam 9. In paragraph 8, The above electric power and first steam are produced by using the above high temperature cooling gas in the above boiler, A method for producing hydrogen in which the first steam is not supplied to the electrolysis facility.

10. In paragraph 8, The above coke, A method for producing hydrogen by cooling using the cooling gas in a dry digestion facility fluidly connected to the above boiler.

11. In paragraph 10, The above boiler, A hydrogen production method configured to produce 10MW or more of electricity based on a supply amount (ton / hr) of 80ton / hr of coke fed into the above dry digestion facility.

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