Distributed electric power system using hydrogen fuel cell for domestic use and method for supplying electric power using the same

Abstract

The present invention relates to a household distributed power system using a hydrogen fuel cell and a method for supplying power using the same. In one embodiment, the household distributed power system using a hydrogen fuel cell comprises: a hydrogen production unit that generates hydrogen and carbon by-products by thermally decomposing hydrocarbons; and a hydrogen power generation unit that generates electricity using the hydrogen; wherein the generated electricity is transferred to a demand location.

Description

Technology Field

[0001] The present invention relates to a household distributed power system using a hydrogen fuel cell and a power supply method using the same. Background Technology

[0003] Currently in Korea, large-scale electricity is produced through centralized power generation, and the generated power is supplied to industries and households that require it through transmission, transformation, and distribution. However, centralized generation involves transmitting, transforming, and distributing electricity to regions far from the power plant. Consequently, problems such as energy loss and rising electricity rates have occurred during the transmission, transformation, and distribution processes.

[0004] In the case of centralized power generation, a problem arises where the entire power system fails if a single power plant malfunctions. This invariably leads to issues regarding system stability. Furthermore, centralized power generation generally consists mostly of thermal power plants that use fossil fuels. Consequently, nitrogen oxides and sulfur oxides, which are causes of fine dust, are emitted, as well as carbon dioxide, a greenhouse gas. Therefore, issues arise regarding the costs associated with treating nitrogen and sulfur oxides during power plant operations, as well as environmental costs due to greenhouse gas emissions.

[0005] Since centralized power plants produce electricity at large-scale power plants, it is difficult to flexibly adjust power production, which has the disadvantage of making it difficult to respond to times when electricity demand surges.

[0006] Furthermore, most fossil fuels (such as oil) required to operate centralized power plants are imported. Consequently, there is a disadvantage in that it is difficult to ensure price stability depending on international circumstances. This, in turn, can lead to problems regarding the stability of the power industry.

[0007] The background technology related to the present invention is disclosed in Korean Published Patent Application No. 2019-0107360 (published September 20, 2019; Title of Invention: Power Generation System Using a Seawater Electrolysis Module). The problem to be solved

[0009] One objective of the present invention is to provide a residential distributed power system capable of simultaneously realizing power generation, power supply, and carbon neutrality, and having excellent eco-friendliness by suppressing the emission of environmentally harmful substances.

[0010] Another objective of the present invention is to provide a residential distributed power system capable of directly supplying power to demand centers and offering excellent power supply stability and energy efficiency.

[0011] Another objective of the present invention is to provide a residential distributed power system with excellent productivity and economic efficiency, capable of producing high-value-added carbon materials and pyrolysis hydrogen using renewable energy, and enabling stable hydrogen production and supply.

[0012] Another objective of the present invention is to provide a residential distributed power system that can be installed in areas supplied with city gas, has excellent utility as a distributed power system, and allows for the miniaturization and simplification of the system.

[0013] Another objective of the present invention is to provide a power supply method using the above-described household distributed power system.

[0014] Another objective of the present invention is to provide a method for recovering carbon materials using the above-mentioned household distributed power system or power supply method.

[0015] Another objective of the present invention is to provide a carbon material recovered by the carbon material recovery method described above. means of solving the problem

[0017] One aspect of the present invention relates to a residential distributed power system using a hydrogen fuel cell. In one embodiment, the residential distributed power system comprises: a hydrogen production unit that generates hydrogen and carbon by-products by thermally decomposing a hydrocarbon; and a hydrogen power generation unit that generates electricity using the hydrogen, wherein the generated electricity is transferred to a demand location.

[0018] In another embodiment of the present invention, the household distributed power system comprises: a hydrogen production unit that pyrolyzes city gas to produce hydrogen-containing gas and carbon byproducts; a hydrogen separation unit that separates hydrogen from the hydrogen-containing gas; a hydrogen power generation unit that produces electricity using the hydrogen; and an energy storage system unit in which the electricity is stored, wherein the stored electricity is transferred to a demand location.

[0019] In one embodiment, the household distributed power system further includes a renewable energy unit that produces electrical energy using one or more renewable energy sources among hydropower, wind power, and solar power; and the produced electrical energy can be transferred to the hydrogen production unit and used for the pyrolysis.

[0020] In one embodiment, the hydrogen production unit is equipped with a catalyst, the catalyst includes a red mud catalyst, and the pyrolysis can be carried out at 850 to 950°C.

[0021] In one embodiment, the hydrogen power generation unit may include one or more hydrogen fuel cells that produce electricity using hydrogen and oxygen.

[0022] In one embodiment, the household distributed power system further includes a carbon material recovery unit that purifies the carbon byproduct to produce a carbon material; the carbon material recovery unit may include a carbon stripping unit that recovers carbon components by contacting the carbon byproduct with a strong acid and potassium permanganate (KMnO4), a primary purification unit that purifies the carbon components with a strong acid or a strong base, and a secondary purification unit that obtains carbon oxides by purifying the primary purified carbon components with hydrogen fluoride (HF).

[0023] In one embodiment, the carbon material recovery unit may further include a first reduction unit that first reduces the carbon oxide using a reducing solution and a second reduction unit that secondarily reduces the first reduced carbon oxide using sulfuric acid to obtain reduced carbon oxide.

[0024] In one embodiment, the hydrogen separation unit can separate hydrogen from a hydrogen-containing gas using a pressure swing adsorption (PSA) method.

[0025] In one embodiment, the hydrogen separation unit separates hydrogen and city gas from a hydrogen-containing gas, and the city gas can be introduced into a gas supply line and then into the hydrogen production unit.

[0026] In one embodiment, the household distributed power system may further include a hydrogen storage unit in which hydrogen is transferred from the hydrogen separation unit and stored.

[0027] In one embodiment, the energy storage system may include a battery in which power is stored, a battery management system (BMS) electrically connected to the battery and controlling the battery, a power conversion system (PCS) that converts the voltage characteristics of the power stored in the battery and transmits it to a demand source, and a total energy management system (EMS) electrically connected to and controlling the battery management system and the power conversion system.

[0028] In one embodiment, the total energy management system can calculate the required amount of power using power consumption data of the demand source and control a power conversion system to transfer power corresponding to the amount of power to the demand source.

[0029] Another aspect of the present invention relates to a method for supplying power using the above-described household distributed power system. In one embodiment, the method for supplying power comprises the step of thermally decomposing a hydrocarbon to produce hydrogen and carbon byproducts; and the step of producing electricity using the hydrogen; wherein the produced electricity is transferred to a demand location.

[0030] In another embodiment of the present invention, the power supply method comprises the steps of: thermally decomposing city gas to produce hydrogen-containing gas and carbon byproducts; separating hydrogen from the hydrogen-containing gas; producing electricity using the hydrogen; and storing the electricity in an energy storage system; wherein the stored electricity is transferred to a demand location.

[0031] In one embodiment, electrical energy produced using one or more renewable energy sources among hydropower, wind power, and solar power can be transferred and used for the pyrolysis.

[0032] In one embodiment, the pyrolysis is carried out under a catalyst, the catalyst includes a red mud catalyst, and the pyrolysis can be carried out at 850 to 950°C.

[0033] In one embodiment, the step of producing the power can produce power using hydrogen and oxygen in one or more hydrogen fuel cells.

[0034] In one embodiment, the hydrogen-containing gas is separated into hydrogen and city gas, and the city gas can be introduced into a gas supply line and pyrolyzed.

[0035] In one embodiment, the energy storage system may include a battery in which power is stored, a battery management system (BMS) electrically connected to the battery and controlling the battery, a power conversion system (PCS) that converts the voltage characteristics of the power stored in the battery, and a total energy management system (EMS) electrically connected to and controlling the battery management system and the power conversion system.

[0036] In one embodiment, the total energy management system can calculate the required amount of power using power consumption data of the demand source and control a power conversion system to transfer power corresponding to the amount of power to the demand source.

[0037] Another aspect of the present invention relates to a method for recovering carbon materials using the above-described household distributed power system or power supply method. In one embodiment, the carbon material recovery method comprises the steps of: recovering carbon by-products recovered by thermal decomposition of hydrocarbons or city gas under a catalyst by contacting them with a strong acid and potassium permanganate (KMnO4) to recover carbon components; treating the carbon components with a strong acid or a strong base to perform primary purification; and treating the primary purified carbon components with hydrogen fluoride (HF) to perform secondary purification to obtain carbon oxides.

[0038] In another embodiment of the present invention, the carbon material recovery method comprises the steps of: recovering carbon by-products recovered by thermal decomposition of hydrocarbons or city gas under a catalyst by contacting them with a strong acid and potassium permanganate (KMnO4) to recover carbon components; treating the carbon components with a strong acid or a strong base to perform primary purification; treating the primary purified carbon components with hydrogen fluoride (HF) to perform secondary purification to obtain carbon oxides; reducing the carbon oxides using a reducing solution to perform primary reduction; and reducing the primary reduced carbon oxides using sulfuric acid to perform secondary reduction to obtain reduced carbon oxides.

[0039] Another aspect of the present invention relates to a carbon material recovered by the carbon material recovery method described above. Effects of the invention

[0041] The residential distributed power system using a hydrogen fuel cell and the power supply method using the same according to the present invention can simultaneously realize power generation, power supply, and carbon neutrality; it is highly eco-friendly by suppressing the emission of environmentally harmful substances; it can directly supply power to demand centers; it has excellent power supply stability and energy efficiency; it enables the production of high-value-added carbon materials and the production of pyrolysis hydrogen using renewable energy; it has excellent productivity and economic efficiency by enabling stable hydrogen production and supply; it can be installed in areas supplied with city gas; it has excellent usability as a distributed power system; and it can perform the role of a distributed power system for each region by allowing for system miniaturization and simplification. Brief explanation of the drawing

[0043] FIG. 1 shows a household distributed power system according to one embodiment of the present invention. FIG. 2 shows a household distributed power system according to another embodiment of the present invention. Specific details for implementing the invention

[0044] In describing the present invention, if it is determined that a detailed description of related known technologies or configurations could unnecessarily obscure the essence of the invention, such detailed description will be omitted.

[0045] Furthermore, the terms described below are defined in consideration of their functions in the present invention; since these may vary depending on the intentions or practices of the user or operator, their definitions should be based on the content throughout this specification describing the present invention.

[0047] Home distributed power system using hydrogen fuel cells

[0048] One aspect of the present invention relates to a household distributed power system using a hydrogen fuel cell.

[0050] First specific example

[0051] FIG. 1 illustrates a household distributed power system according to one embodiment of the present invention. Referring to FIG. 1, the household distributed power system (1000) comprises: a hydrogen production unit (100) that generates hydrogen and carbon by-products by thermally decomposing hydrocarbons; and a hydrogen power generation unit (200) that generates power using the hydrogen, and the generated power is transferred to a demand location (500).

[0052] Referring to FIG. 1 above, the power (electricity) produced according to the present invention can be transferred to a demand location (500) for use. The demand location may be a household, such as an apartment complex. Hydrogen for producing power can be produced by utilizing hydrocarbons or LNG (liquefied natural gas) supplied to the apartment complex, and then supplied to a fuel cell to generate power. In addition, carbon byproducts produced as byproducts can be recovered to obtain economic benefits.

[0053] In one embodiment, the hydrogen production unit (100) can produce hydrogen and carbon byproducts through the decomposition of thermochemical hydrocarbon compounds. For example, the decomposition of thermochemical hydrocarbon compounds occurs as shown in the following reaction scheme 1:

[0054] [Reaction Equation 1]

[0055] C x H y → xC + y / 2H2.

[0056] In one embodiment, the hydrocarbon may include methane (CH4). For example, hydrogen and carbon (carbon byproduct) can be produced from methane as shown in Reaction Scheme 1-1 below. As the reaction is an endothermic reaction as shown in Reaction Scheme 1-1, energy is required for the reaction to occur:

[0057] [Reaction Equation 1-1]

[0058] CH4→ C + 2H2△H o 298 = 37kJ.

[0059] The thermal decomposition of methane is an endothermic reaction requiring high-temperature process conditions, and a large amount of energy is required to produce hydrogen in actual plants. Consequently, producing hydrogen, an eco-friendly energy source, actually requires an excess amount of electrical energy.

[0060] Conventional centralized power plants generated electricity using fossil fuels such as oil. Consequently, there were issues regarding the generation of greenhouse gases (such as carbon dioxide) and atmospheric pollutants (such as nitrogen oxides and sulfur oxides) during power plant operations. Furthermore, since most fossil fuels like oil were imported, it was difficult to ensure price stability in response to international conditions, and securing the stability of the power supply was also challenging.

[0061] On the other hand, the present invention generates electricity using hydrogen produced by the thermal decomposition of hydrocarbons or city gas, enabling carbon neutrality, and allows for stable hydrogen production and supply using city gas, thereby offering excellent eco-friendliness and economic efficiency.

[0062] Referring to FIG. 1 above, the household distributed power system (1000) may further include a renewable energy unit (300) that produces electrical energy using one or more renewable energy sources among hydropower, wind power, and solar power. For example, the renewable energy unit (300) may produce electrical energy using solar power. The electrical energy produced by the renewable energy unit (300) may be transferred to a hydrogen production unit (100) and used for the pyrolysis. When the electrical energy is transferred to the hydrogen production unit, it may be environmentally friendly, and during the pyrolysis reaction, it may be energy efficient and economical.

[0063] In one embodiment of the present invention, the hydrogen production unit (100) may be equipped with a catalyst. Thermochemical methane decomposition occurs at approximately 2,000°C under conditions without a catalyst. On the other hand, when using the catalyst of the present invention, a thermal decomposition reaction may occur at 850°C or higher, for example, 850 to 950°C.

[0064] The hydrogen production unit (100) can perform thermal decomposition of hydrocarbons or city gas at 850 to 950°C under catalytic conditions. Under these conditions, energy saving effects, productivity, and economic efficiency can be excellent.

[0065] In one embodiment, the hydrogen production unit is equipped with a catalyst, and the catalyst may include a red mud catalyst.

[0066] In one embodiment, the catalyst may include red mud. The red mud may be a byproduct (residue) of bauxite, which is a raw material for the Bayer process for the production of aluminum hydroxide, but is not limited thereto. When the red mud is included, high-quality hydrogen can be produced by easily thermally decomposing hydrocarbons or city gas at 850°C or higher, and carbon material can be easily recovered thereafter to produce high-purity and high-quality carbon material.

[0067] For example, the catalyst may include a material containing iron (Fe) components (red mud) and iron sulfate (FeSO4).

[0068] In one embodiment, the red mud may contain 15 to 50 weight percent of iron (Fe) based on the total weight. When included in this amount, the catalytic activity is excellent, making it possible to easily pyrolyze hydrocarbons or city gas at 850°C or higher to produce high-quality hydrogen, and subsequently easily recover carbon material to manufacture high-purity and high-quality carbon material. For example, it may contain 25 to 40 weight percent.

[0069] In one embodiment, the red mud may contain 26 to 45 weight percent iron (Fe) and 1 to 35 weight percent aluminum (Al) based on the total weight.

[0070] The above aluminum (Al) may be included in an amount of 1 to 35 weight percent based on the total weight of the red mud. When included within this content range, the strength and durability of the catalyst are excellent, the catalytic activity is not reduced during the direct decomposition of hydrocarbons, and the carbon material can be easily recovered to produce high-purity and high-quality carbon material. For example, it may be included in an amount of 15 to 25 weight percent.

[0071] As another example, the above red mud catalyst may further include one or more of calcium (Ca), titanium (Ti), sodium (Na), and silicon (Si).

[0072] In one embodiment, the hydrogen power generation unit (200) may include one or more hydrogen fuel cells that produce electricity using hydrogen and oxygen.

[0073] For example, the hydrogen power generation unit (200) has one or more hydrogen fuel cells connected in parallel, and hydrogen supplied from the hydrogen production unit (100) and oxygen are supplied respectively to produce electricity through their electrochemical reaction.

[0074] Traditionally, most hydrogen used domestically was imported or byproduct hydrogen. Consequently, the costs associated with producing, transporting, and importing hydrogen for power generation became a cause of increased financial burden.

[0075] On the other hand, the present invention stably produces hydrogen by thermally decomposing hydrocarbons or city gas and may further include a hydrogen storage unit to ensure a smooth supply of hydrogen to the hydrogen power generation unit. In addition, economic viability can be secured through the reprocessing and sale of carbon by-products obtained during the thermal decomposition process.

[0076] Carbon byproducts generated through the decomposition of thermochemical hydrocarbon compounds in the hydrogen production unit (100) are separated separately, and the separated carbon can be converted into high-value-added carbon materials (graphene, carbon nanotubes, etc.) through a process and sold, which can be economically viable.

[0077] In one embodiment, the household distributed power system may further include a carbon material recovery unit (not shown) that purifies carbon by-products recovered from the hydrogen production unit to produce carbon material.

[0078] In one embodiment, the carbon material may include one or more of graphene, graphite, graphene oxide (GO), reduced graphene oxide (rGO), and carbon nanotubes (CNT).

[0079] In one embodiment, the carbon material recovery unit may include a carbon stripping unit that recovers carbon components by contacting the carbon byproduct with a strong acid and potassium permanganate (KMnO4), a primary purification unit that purifies the carbon components with a strong acid or a strong base, and a secondary purification unit that obtains carbon oxides by purifying the primary purified carbon components with hydrogen fluoride (HF).

[0080] The carbon byproduct may include one or more of the carbon byproduct generated during the thermal decomposition of hydrocarbons in the hydrogen production unit (100) and the carbon byproduct formed on the surface of the reacted catalyst (spent catalyst). In addition to carbon, the carbon byproduct may include various metal components derived from the red mud and iron compounds of the catalyst.

[0081] When the above carbon byproduct is brought into contact with a strong acid and potassium permanganate, the carbon surrounding the carbon and catalyst in the recovered carbon byproduct can be easily separated (carbon stripping) to recover the carbon components. In addition, in the carbon stripping section, the potassium permanganate in the carbon components can be removed by contacting the recovered carbon components with hydrogen peroxide (H2O2).

[0082] In one embodiment, the strong acid for recovering the carbon component may include one or more of sulfuric acid (H2SO4), nitric acid (HNO3), and hydrochloric acid (HCl). For example, it may include sulfuric acid.

[0083] The carbon component recovered from the carbon exfoliation portion may include one or more of graphene, graphite, and carbon nanotubes.

[0084] In one embodiment, when performing primary purification in the primary purification unit, the strong acid may include one or more of sulfuric acid (H2SO4), nitric acid (HNO3), hydrochloric acid (HCl), and aqua regia, and the strong base may include sodium hydroxide (NaOH). When the strong acid or strong base is applied, metal oxide components contained in the exfoliated carbon components can be easily removed.

[0085] For example, the above first purification step can be carried out by adding the carbon component to a strong acid or strong base and stirring at 50 to 80°C for 6 to 15 hours. Under these conditions, metal components such as transition metal oxides of the carbon component can be easily removed. For example, during the above first purification, the carbon component can be washed with water and dried after stirring.

[0086] In the above secondary purification section, secondary purification may be performed to produce carbon oxide by removing typical metals such as aluminum oxide (Al2O3) and silicon oxide (SiO2) contained in the carbon component purified in the primary purification.

[0087] In one embodiment, the hydrogen fluoride may be at a concentration of 1 to 10 volume%. Under these conditions, the removal efficiency of the typical metal may be excellent.

[0088] The above secondary purification can be performed by immersing the carbon component purified in the above primary purification in hydrogen fluoride and treating it at 40 to 60°C. Under these conditions, a carbon oxide from which the typical metal component has been easily removed can be produced. For example, during the above secondary purification, the mixture can be washed with water and dried after stirring.

[0089] In one embodiment, the carbon material recovery unit may further include a first reduction unit that first reduces carbon oxide using a reducing solution and a second reduction unit that secondarily reduces the first reduced carbon oxide using sulfuric acid to obtain reduced carbon oxide.

[0090] In one embodiment, the reducing solution comprises a reducing agent and a solvent, and the reducing agent may include one or more of hydrazine, sodium hydride, hydroquinone, sodium borohydride, citric acid, ascorbic acid, and glucose.

[0091] In one embodiment, when the first reduction is performed in the first reduction section, the carbon oxide and the reduction solution may be in contact at 100 to 180°C. Under these conditions, the reduction composition can be easily prepared. For example, the reduction composition can be prepared by adding the carbon oxide to the reduction solution and stirring for 1 to 5 hours while heating to 100 to 180°C. Then, the stirred mixture can be washed with water and dried to obtain the first reduced carbon oxide (reduction composition).

[0092] The secondary reduction in the second reduction section above can be carried out by washing and drying the precipitate obtained by contacting the primary reduced carbon oxide (reduction composition) with sulfuric acid at 150 to 220°C.

[0093] For example, in the second reduction section above, the primary reduced carbon oxide (reduction composition) is introduced into sulfuric acid to disperse it, and then the reaction is carried out by stirring for 1 to 30 hours while maintaining the temperature at 150 to 220°C, and the reduced carbon oxide is obtained by washing and drying.

[0095] Second specific example

[0096] FIG. 2 illustrates a household distributed power system according to another embodiment of the present invention. Referring to FIG. 2, the household distributed power system (2000) comprises: a hydrogen production unit (100) that pyrolyzes city gas to produce hydrogen-containing gas and carbon byproducts; a hydrogen separation unit (110) that separates hydrogen from the hydrogen-containing gas; a hydrogen power generation unit (200) that produces electricity using the hydrogen; and an energy storage system unit (400) in which the electricity is stored, and the stored electricity is transferred to a demand location (500).

[0097] Referring to FIG. 2 above, the power (electricity) produced according to the present invention can be supplied to a demand location (500) for use. The demand location may be a household, such as an apartment complex. Hydrogen for producing power can be produced by utilizing LNG (liquefied natural gas) supplied to the apartment complex and supplied to a fuel cell. In addition, carbon byproducts produced as a byproduct can be recovered to obtain economic benefits.

[0098] The above city gas may include liquefied natural gas (LNG). For example, the city gas may be supplied to the hydrogen production unit by connecting without restriction to the city gas pipeline (gas supply line) in the supply area.

[0099] In this invention, city gas is utilized to inject raw materials into a thermochemical hydrocarbon compound decomposition system (hydrogen production unit). Unreacted LNG can be recycled using a PSA (hydrogen separation unit). Additionally, a gas separator can be used to store high-concentration hydrogen (99.9% or higher) in a hydrogen storage unit. The stored hydrogen is then transferred to a hydrogen power generation unit and can be used as needed for hydrogen production.

[0100] In one embodiment, the household distributed power system further includes a renewable energy unit that produces electrical energy using one or more renewable energy sources among hydropower, wind power, and solar power; and the produced electrical energy can be transferred to the hydrogen production unit and used for the pyrolysis.

[0101] In one embodiment, the hydrogen production unit is equipped with a catalyst, the catalyst includes a red mud catalyst, and the pyrolysis can be carried out at 850 to 950°C.

[0102] In one embodiment, the hydrogen separation unit (110) can separate the hydrogen-containing gas into hydrogen and unreacted city gas (LNG) by a pressure swing adsorption (PSA) method.

[0103] Referring to FIG. 2 above, the hydrogen separation unit (110) separates hydrogen and city gas from a hydrogen-containing gas, and the city gas can be introduced into a gas supply line (12). The city gas introduced into the gas supply line (12) can be supplied to a demand center or introduced into a hydrogen production unit (100).

[0104] In one embodiment, the hydrogen power generation unit may include one or more hydrogen fuel cells that produce electricity using hydrogen and oxygen.

[0105] For example, the hydrogen power generation unit (200) has one or more hydrogen fuel cells connected in parallel, and hydrogen supplied from the hydrogen production unit (100) and oxygen are supplied respectively to produce electricity through their electrochemical reaction.

[0106] The above hydrogen fuel cells can be configured in parallel by matching the number of fuel cells to supply power corresponding to the number of households at the point of demand. In addition, spare fuel cells can be installed so that they can be utilized when maintaining the above hydrogen fuel cells.

[0107] Referring to FIG. 2 above, the household distributed power system (2000) may further include a hydrogen storage unit (120) in which hydrogen is transferred from the hydrogen separation unit (110) and stored. Hydrogen with a high concentration (99.9% or more) may be stored in the hydrogen storage unit. Referring to FIG. 2 above, the hydrogen stored in the hydrogen storage unit (120) may be transferred to a hydrogen power generation unit (200) and utilized for power generation of a hydrogen fuel cell.

[0108] Although not shown in FIG. 2, the hydrogen power generation unit (200) may further include a compressor (not shown) that compresses air to generate oxygen and transfers it to the hydrogen fuel cell.

[0109] In one embodiment, the pyrolysis is carried out under a catalyst, and the catalyst may include a red mud catalyst. In one embodiment, the pyrolysis may be carried out under a catalyst at 850 to 950°C.

[0110] The hydrogen production unit (100) can perform the thermal decomposition of the city gas under catalytic conditions at 850 to 950°C. Under these conditions, productivity and economic efficiency can be excellent.

[0111] In one embodiment, the catalyst may include red mud. The red mud may be a byproduct (residue) of bauxite, which is a raw material for the Bayer process for the production of aluminum hydroxide, but is not limited thereto. When the red mud is included, high-quality hydrogen can be produced by easily thermally decomposing hydrocarbons or city gas at 850°C or higher, and carbon material can be easily recovered thereafter to produce high-purity and high-quality carbon material.

[0112] For example, the catalyst may include a material containing iron (Fe) components (red mud) and iron sulfate (FeSO4).

[0113] In one embodiment, the red mud may contain 15 to 50 weight percent of iron (Fe) based on the total weight. When included in this amount, the catalytic activity is excellent, making it possible to easily pyrolyze hydrocarbons or city gas at 850°C or higher to produce high-quality hydrogen, and subsequently easily recover carbon material to manufacture high-purity and high-quality carbon material. For example, it may contain 25 to 40 weight percent.

[0114] In one embodiment, the red mud may contain 26 to 45 weight percent iron (Fe) and 1 to 35 weight percent aluminum (Al) based on the total weight.

[0115] The above aluminum (Al) may be included in an amount of 1 to 35 weight percent based on the total weight of the red mud. When included within this content range, the strength and durability of the catalyst are excellent, the catalytic activity is not reduced during the direct decomposition of hydrocarbons, and the carbon material can be easily recovered to produce high-purity and high-quality carbon material. For example, it may be included in an amount of 15 to 25 weight percent.

[0116] As another example, the above red mud catalyst may further include one or more of calcium (Ca), titanium (Ti), sodium (Na), and silicon (Si).

[0117] In one embodiment, the household distributed power system may further include a carbon material recovery unit (not shown) that purifies carbon by-products recovered from the hydrogen production unit to produce carbon material.

[0118] In one embodiment, the carbon material may include one or more of graphene, graphite, graphene oxide (GO), reduced graphene oxide (rGO), and carbon nanotubes (CNT).

[0119] In one embodiment, the carbon material recovery unit may include a carbon stripping unit that recovers carbon components by contacting the carbon byproduct with a strong acid and potassium permanganate (KMnO4), a primary purification unit that purifies the carbon components with a strong acid or a strong base, and a secondary purification unit that obtains carbon oxides by purifying the primary purified carbon components with hydrogen fluoride (HF). Additionally, in the carbon stripping unit, potassium permanganate in the carbon components may be removed by contacting the recovered carbon components with hydrogen peroxide (H2O2).

[0120] The carbon byproduct may include one or more of the carbon byproduct generated during the thermal decomposition of city gas in the hydrogen production unit (100) and the carbon byproduct formed on the surface of the reacted catalyst (spent catalyst). In addition to carbon, the carbon byproduct may include various metal components derived from the red mud and iron compounds of the catalyst.

[0121] When the above carbon byproduct is brought into contact with a strong acid and potassium permanganate, the carbon surrounding the carbon and catalyst in the recovered carbon byproduct can be easily broken down (carbon stripping) to recover the carbon components.

[0122] In one embodiment, the strong acid for recovering the carbon component may include one or more of sulfuric acid (H2SO4), nitric acid (HNO3), and hydrochloric acid (HCl). For example, it may include sulfuric acid.

[0123] The carbon component recovered from the carbon exfoliation portion may include one or more of graphene, graphite, and carbon nanotubes.

[0124] In one embodiment, when performing primary purification in the primary purification unit, the strong acid may include one or more of sulfuric acid (H2SO4), nitric acid (HNO3), hydrochloric acid (HCl), and aqua regia, and the strong base may include sodium hydroxide (NaOH). When the strong acid or strong base is applied, metal oxide components contained in the exfoliated carbon components can be easily removed.

[0125] For example, the above first purification step can be carried out by adding the carbon component to a strong acid or strong base and stirring at 50 to 80°C for 6 to 15 hours. Under these conditions, metal components such as transition metal oxides of the carbon component can be easily removed. For example, during the above first purification, the carbon component can be washed with water and dried after stirring.

[0126] In the above secondary purification section, secondary purification may be performed to produce carbon oxide by removing typical metals such as aluminum oxide (Al2O3) and silicon oxide (SiO2) contained in the carbon component purified in the primary purification.

[0127] In one embodiment, the hydrogen fluoride may be at a concentration of 1 to 10 volume%. Under these conditions, the removal efficiency of the typical metal may be excellent.

[0128] The above secondary purification can be performed by immersing the carbon component purified in the above primary purification in hydrogen fluoride and treating it at 40 to 60°C. Under these conditions, a carbon oxide from which the typical metal component has been easily removed can be produced. For example, during the above secondary purification, the mixture can be washed with water and dried after stirring.

[0129] In one embodiment, the carbon material recovery unit may further include a first reduction unit that first reduces carbon oxide using a reducing solution and a second reduction unit that secondarily reduces the first reduced carbon oxide using sulfuric acid to obtain reduced carbon oxide.

[0130] In one embodiment, the reducing solution comprises a reducing agent and a solvent, and the reducing agent may include one or more of hydrazine, sodium hydride, hydroquinone, sodium borohydride, citric acid, ascorbic acid, and glucose.

[0131] In one embodiment, when the first reduction is performed in the first reduction section, the carbon oxide and the reduction solution may be in contact at 100 to 180°C. Under these conditions, the reduction composition can be easily prepared. For example, the reduction composition can be prepared by adding the carbon oxide to the reduction solution and stirring for 1 to 5 hours while heating to 100 to 180°C. Then, the stirred mixture can be washed with water and dried to obtain the first reduced carbon oxide (reduction composition).

[0132] The secondary reduction in the second reduction section above can be carried out by washing and drying the precipitate obtained by contacting the primary reduced carbon oxide (reduction composition) with sulfuric acid at 150 to 220°C.

[0133] For example, in the second reduction section above, the primary reduced carbon oxide (reduction composition) is introduced into sulfuric acid to disperse it, and then the reaction is carried out by stirring for 1 to 30 hours while maintaining the temperature at 150 to 220°C, and the reduced carbon oxide is obtained by washing and drying.

[0134] In addition, the system can be configured so that the power produced from the fuel cell is stored and the power is controlled through the energy storage system (400), thereby enabling stable power supply to power demand centers.

[0135] In one embodiment, the energy storage system unit (400) may include a battery in which the power is stored, a battery management system (BMS) electrically connected to the battery and controlling the battery, a power conditioning system (PCS) that converts the voltage characteristics of the power stored in the battery and transmits it to a demand source, and an energy management system (EMS) electrically connected to and controlling the battery management system and the power conditioning system.

[0136] In one embodiment, the total energy management system can calculate the required amount of power using power consumption data of the demand source and control a power conversion system to transfer power corresponding to the amount of power to the demand source.

[0137] In one embodiment, the total energy management system is electrically connected to a hydrogen production unit (100), a hydrogen separation unit (110), a hydrogen storage unit (120), and a hydrogen power generation unit (200), and can manage and control the household distributed power system as a whole by controlling each of them. For example, the total energy management system can be used to manage and control hydrogen production, power production, and power supply.

[0138] In one embodiment, the total energy management system utilizes and collects power consumption data from the demand source, calculates the required amount of power using the collected power consumption data, controls the amount of hydrogen produced through the pyrolysis reaction of the hydrogen production unit (100) or controls the amount of hydrogen produced transferred from the hydrogen storage unit (120) to the hydrogen power generation unit (200) to produce power corresponding to the required amount of power, and controls the power conversion system to transfer the power corresponding to the amount of power to the demand source. Under these conditions, excellent economic efficiency can be achieved by preventing excessive hydrogen production and power production.

[0139] For example, the total energy management system can control the amount of hydrogen produced by controlling the electronic regulator and electronic flow controller equipped in the hydrogen production unit (100) according to the required amount of power.

[0141] Power supply method using a residential distributed power system

[0142] Another aspect of the present invention relates to a power supply method using the above-described household distributed power system.

[0144] First specific example

[0145] In one embodiment, the power supply method comprises (S10) a step of thermally decomposing a hydrocarbon to produce hydrogen and carbon byproducts; and (S20) a step of producing electricity using the hydrogen; and the produced electricity is transferred to a demand location.

[0146] In one embodiment, the pyrolysis is carried out under a catalyst, and the catalyst may include a red mud catalyst. In one embodiment, the pyrolysis may be carried out under a catalyst at 850 to 950°C.

[0147] The above red mud catalyst may be the same as that described above.

[0148] In one embodiment, electrical energy produced using one or more renewable energy sources among hydropower, wind power, and solar power can be transferred and used for the pyrolysis.

[0149] In one embodiment, the step of producing power may produce power using hydrogen and oxygen in one or more hydrogen fuel cells. For example, power may be produced in a hydrogen power generation unit comprising one or more hydrogen fuel cells.

[0150] For example, the hydrogen power generation unit may have one or more hydrogen fuel cells connected in parallel, and hydrogen and oxygen supplied from the hydrogen production unit may be supplied respectively to produce electricity through their electrochemical reaction.

[0151] The electricity produced according to the present invention can be transported to a demand center for use. The demand center may be households, such as apartment complexes. Hydrogen for generating electricity can be produced by utilizing hydrocarbons or LNG (liquefied natural gas) supplied to the apartment complex, and then supplied to a fuel cell to generate power. Additionally, carbon byproducts produced as a byproduct can be recovered to obtain economic benefits.

[0153] Second specific example

[0154] In another embodiment of the present invention, the power supply method comprises: (S11) a step of thermally decomposing city gas to produce hydrogen-containing gas and carbon byproducts; (S21) a step of separating hydrogen from the hydrogen-containing gas; (S31) a step of producing electricity using the hydrogen; and (S41) a step of storing the electricity in an energy storage system; wherein the stored electricity is transferred to a demand location.

[0155] In one embodiment, electrical energy produced using one or more renewable energy sources among hydropower, wind power, and solar power can be transferred and used for the pyrolysis.

[0156] In one embodiment, the above electrical energy can be produced using solar power generation.

[0157] Meanwhile, most of the energy required for the thermal decomposition of the above city gas or hydrocarbon gas can be provided through renewable energy sources (residential solar power generation). The amount of electrical energy generated through the above renewable energy sources and the energy required for thermochemical methane decomposition are as follows. At this time, the power demand (energy balance) was calculated based on an apartment complex of 1,000 households.

[0158] (1) Electricity consumption = 0.5kW (based on 1 household of 4 people) x 1,000 households, power consumption = 0.5MW

[0159] (2) Solar power generation = 400W x sunlight (5hr / day) x 1,000 households, power generation = 2,000kWh

[0160] (3) Decomposition of city gas (methane gas) 283 kmol x 37 kJ / mol (methane conversion rate 70%), heat of reaction = 2,035 kWh

[0161] Referring to (1) to (3) above, approximately 0.5 MW of hydrogen fuel cell power generation is required for an apartment complex of 1,000 households. To achieve this, 283 kmol of methane must be converted per day based on a methane conversion rate of 70%. At this time, the reaction heat required for hydrogen production is approximately 2,000 kWh. That is, the electrical energy required for hydrogen production can be mostly provided through renewable energy sources (residential solar power generation).

[0162] In one embodiment, the pyrolysis is carried out under a catalyst, the catalyst includes a red mud catalyst, and the pyrolysis can be carried out at 850 to 950°C.

[0163] The above red mud catalyst may be the same as that described above.

[0164] In one embodiment, the step of producing the power can produce power using hydrogen and oxygen in one or more hydrogen fuel cells.

[0165] In one embodiment, the hydrogen-containing gas is separated into hydrogen and city gas, and the city gas can be introduced into a gas supply line and pyrolyzed.

[0166] In one embodiment, the energy storage system may include a battery in which power is stored, a battery management system (BMS) electrically connected to the battery and controlling the battery, a power conversion system (PCS) that converts the voltage characteristics of the power stored in the battery, and a total energy management system (EMS) electrically connected to and controlling the battery management system and the power conversion system.

[0167] In one embodiment, the total energy management system can calculate the required amount of power using power consumption data of the demand source and control a power conversion system to transfer power corresponding to the amount of power to the demand source.

[0168] Under the above conditions, it offers excellent utility as a distributed power system, which can improve the stability of power supply and increase energy efficiency. Additionally, stable power supply can be achieved by utilizing an energy storage system.

[0169] In one embodiment, the total energy management system is electrically connected to the hydrogen production unit, hydrogen separation unit, hydrogen storage unit, and hydrogen power generation unit, and can manage and control the household distributed power system as a whole by controlling each of them. For example, the total energy management system can be used to manage and control hydrogen production, power production, and power supply.

[0170] In one embodiment, the total energy management system utilizes and collects power consumption data from the demand source, calculates the required amount of power using the collected power consumption data, controls the amount of hydrogen produced through the pyrolysis reaction of the hydrogen production unit (100) or controls the amount of hydrogen produced transferred from the hydrogen storage unit (120) to the hydrogen power generation unit (200) to produce power corresponding to the required amount of power, and controls the power conversion system to transfer the power corresponding to the amount of power to the demand source. Under these conditions, excellent economic efficiency can be achieved by preventing excessive hydrogen production and power production.

[0171] For example, the total energy management system can control the amount of hydrogen produced by controlling the electronic regulator and electronic flow controller equipped in the hydrogen production unit (100) according to the required amount of power.

[0173] Carbon material recovery method

[0174] Another aspect of the present invention relates to a method for recovering carbon materials using the above-described household distributed power system or power supply method. In one embodiment, the carbon material recovery method comprises: (S100) a step of recovering carbon by-products recovered by thermal decomposition of hydrocarbons or city gas under a catalyst and contacting them with a strong acid and potassium permanganate (KMnO4) to recover carbon components; (S101) a step of primary purification by treating the carbon components with a strong acid or a strong base; and (S102) a step of secondary purification by treating the primary purified carbon components with hydrogen fluoride (HF) to obtain carbon oxides.

[0175] In the above step (S100), carbon byproducts recovered by thermal decomposition of hydrocarbons or city gas under a catalyst can be contacted with a strong acid and potassium permanganate (KMnO4) to recover carbon components from which metal oxides have been removed.

[0176] In one embodiment, the strong acid may include one or more of sulfuric acid (H2SO4), nitric acid (HNO3), and hydrochloric acid (HCl). For example, it may include sulfuric acid.

[0177] The carbon byproduct may include one or more of the carbon byproduct generated during the thermal decomposition of the city gas or hydrocarbon and the carbon byproduct formed on the surface of the reacted catalyst (spent catalyst). In addition to carbon, the carbon byproduct may include various metal components derived from the red mud and iron compounds of the catalyst.

[0178] When the above carbon byproduct is brought into contact with a strong acid and potassium permanganate, the carbon surrounding the carbon and catalyst in the recovered carbon byproduct can be easily removed (carbon stripping) to recover the carbon component. In one embodiment, the potassium permanganate can be removed by contacting the recovered carbon component with hydrogen peroxide (H2O2).

[0179] In the above step (S101), the carbon component can be purified by treating it with a strong acid or a strong base. For example, the above first purification step may include a step of treating the carbon component at 50 to 80°C in the presence of a strong acid or a strong base. Under these conditions, transition metal oxide components contained in the exfoliated carbon component can be easily removed.

[0180] In one embodiment, during the first purification, the strong acid may include one or more of sulfuric acid (H2SO4), nitric acid (HNO3), hydrochloric acid (HCl), and aqua regia, and the strong base may include sodium hydroxide (NaOH). When the strong acid or strong base is applied, the transition metal oxide component contained in the exfoliated carbon component can be easily removed.

[0181] For example, the above first purification step may be carried out by adding the carbon component to a strong acid or strong base and stirring at 50 to 80°C for 6 to 15 hours. Then, the carbon component after stirring may be washed with water and dried to perform first purification. The drying may be carried out at 70 to 90°C for 1 to 20 hours.

[0182] The above step (S102) is a step of obtaining carbon oxide by treating the above primary purified carbon component with hydrogen fluoride (HF) to perform secondary purification.

[0183] In the above secondary purification section, secondary purification may be performed to produce carbon oxide by removing typical metals such as aluminum oxide (Al2O3) and silicon oxide (SiO2) contained in the carbon component purified in the primary purification.

[0184] In one embodiment, the hydrogen fluoride may be at a concentration of 1 to 10 volume%. Under these conditions, the removal efficiency of the typical metal may be excellent.

[0185] The above secondary purification can be performed by immersing the carbon component purified in the above primary purification in hydrogen fluoride and treating it at 40 to 60°C. Under these conditions, a carbon oxide from which the typical metal component has been easily removed can be produced. For example, during the above secondary purification, the mixture can be washed with water and dried after stirring.

[0186] In one embodiment, the secondary purification may be carried out by including the step of immersing the primary purified carbon component in hydrogen fluoride (HF) and treating it at 40 to 60°C for 12 to 30 hours. Then, the carbon component after stirring may be washed with water and dried to perform secondary purification. The drying may be carried out at 70 to 90°C for 1 to 20 hours. Under these conditions, carbon oxide can be easily obtained.

[0187] The above carbon oxide may include graphene oxide (GO).

[0188] In another embodiment of the present invention, the carbon material recovery method comprises: (S110) a step of recovering carbon components by contacting carbon by-products recovered by pyrolyzing hydrocarbons or city gas under a catalyst with a strong acid and potassium permanganate (KMnO4); (S111) a step of first purifying the carbon components by treating them with a strong acid or a strong base; (S112) a step of secondarily purifying the firstly purified carbon components by treating them with hydrogen fluoride (HF) to obtain carbon oxides; (S113) a step of firstly reducing the carbon oxides using a reducing solution; and (S114) a step of secondarily reducing the firstly reduced carbon oxides using sulfuric acid to obtain reduced carbon oxides.

[0189] Since the above steps (S110); (S111); and (S112) can be carried out in the same manner as described above, a detailed description thereof will be omitted.

[0190] The above step (S113) may yield a reduced composition by contacting the carbon oxide with a reducing solution to perform primary reduction. In one embodiment, the reducing solution may include a reducing agent and a solvent. In one embodiment, the solvent may include one or more of ethylene glycol and water, and the reducing agent may include one or more of hydrazine, sodium hydride, hydroquinone, sodium borohydride, citric acid, ascorbic acid, and glucose.

[0191] In one embodiment, the carbon oxide and the reducing solution may be in contact at 100 to 180°C. Under these conditions, the reducing composition can be easily prepared. For example, the reducing composition can be prepared by adding the carbon oxide to the reducing solution and stirring for 1 to 5 hours while heating to 100 to 180°C. Then, the reducing composition can be washed with water and dried to obtain the reducing composition. For example, water can be added to the reducing composition, the pH adjusted to 7, washed 5 times, and then dried. For example, the drying can be carried out at 70 to 90°C for 1 to 20 hours.

[0192] The above step (S114) is a step of producing a reduced carbon oxide by contacting the primary reduced carbon oxide (reduction composition) with sulfuric acid. In one embodiment, the step of producing the reduced carbon oxide may be carried out by washing and drying the precipitate obtained by contacting the primary reduced carbon oxide (reduction composition) with sulfuric acid at 150 to 220°C.

[0193] For example, the above-mentioned first reduced carbon oxide (reduction composition) can be added to sulfuric acid to disperse it, and then the reaction can be carried out by stirring for 1 to 30 hours while maintaining the temperature at 150 to 220°C. After the reaction is completed, the reaction product can be washed 5 times with distilled water to achieve a pH of 7 and then dried. For example, the drying can be carried out at 70 to 90°C for 1 to 20 hours.

[0194] The above reduced carbon oxide may include reduced graphene oxide (rGO).

[0196] Carbon material recovered by the carbon material recovery method

[0197] Another aspect of the present invention relates to a carbon material recovered by the carbon material recovery method described above.

[0198] In one embodiment, the carbon material may include one or more of graphene, graphite, graphene oxide (GO), reduced graphene oxide (rGO), and carbon nanotubes (CNT).

[0200] Meanwhile, conventional centralized power generation systems supplied electricity using fossil fuels. Consequently, they emitted air pollutants such as nitrogen oxides and sulfur oxides, as well as greenhouse gases (such as carbon dioxide). However, hydrogen-based power generation systems, such as the residential distributed power system of the present invention, have the advantage of not emitting air pollutants (such as nitrogen oxides and sulfur oxides) or greenhouse gases (such as carbon dioxide). Furthermore, through eco-friendly power generation, there is a reduction in environmental costs, such as RECs (Renewable Energy Certificates) and greenhouse gas emission allowances.

[0201] The residential distributed power system of the present invention, as a distributed power system rather than a centralized generation system, can improve the stability of power supply and increase energy efficiency. In addition, stable power supply can be achieved by utilizing an energy storage system.

[0202] The hydrogen required for power generation according to the present invention can be produced using city gas; therefore, the system of the present invention can be installed in residential apartment complexes supplied with city gas. Accordingly, carbon byproducts are refined and resold through the thermochemical decomposition of hydrocarbon compounds using city gas, and economic feasibility regarding hydrogen production costs can be secured through the reduction of hydrogen transportation costs. Consequently, the unit cost of power generation can be reduced.

[0203] In the case of a centralized power generation system, it is necessary to construct systems for transmission, substation, and distribution, and continuous maintenance costs are incurred. However, the power generation system invented in this patent can supply power directly to power demand centers, thereby reducing system construction and maintenance costs for transmission and distribution. Consequently, it may be possible to reduce electricity production costs.

[0205] Hereinafter, the structure and operation of the present invention will be explained in more detail through preferred embodiments. However, these are presented as preferred examples of the present invention and should not be interpreted in any way as limiting the present invention. Details not described herein can be sufficiently technically inferred by those skilled in the art, so such descriptions will be omitted.

[0207] Examples and Comparative Examples

[0208] Example 1

[0209] (1) Configuration of a household distributed power system: A household distributed power system as shown in FIG. 1 was configured. Specifically, the household distributed power system (1000) is configured to include a hydrogen production unit (100) equipped with a red mud catalyst that pyrolyzes hydrocarbons to produce hydrogen and carbon byproducts; and a hydrogen power generation unit (200) that produces electricity using the hydrogen. In addition, the household distributed power system (1000) is equipped with a renewable energy unit (300) that generates electricity using solar power to produce electrical energy and transmits it to the hydrogen production unit (100), and the produced electricity is transmitted to a demand location (500, a household apartment complex). The hydrogen power generation unit (200) is configured by connecting one or more hydrogen fuel cells in parallel to produce electricity using hydrogen and oxygen.

[0210] Specifically, the carbon material recovery unit is equipped with a carbon stripping unit that recovers carbon components by contacting the carbon byproduct with a strong acid and potassium permanganate (KMnO4), a primary purification unit that purifies the carbon components with a strong acid or a strong base, a secondary purification unit that obtains carbon oxide by purifying the primary purified carbon components with hydrogen fluoride (HF), a first reduction unit that reduces the carbon oxide using a reducing solution, and a second reduction unit that obtains reduced carbon oxide by reducing the primary reduced carbon oxide using sulfuric acid.

[0211] (2) Power supply using a household distributed power system: Power was supplied (distributed supply) to demand locations using a household distributed power system (1000). Specifically, hydrocarbons (methane) introduced into the hydrogen production unit (100) were pyrolyzed at 900°C under a red mud catalyst to produce hydrogen and carbon byproducts. In the renewable energy unit (300), electrical energy was produced through solar power generation and used for the pyrolysis reaction in the hydrogen production unit (100).

[0212] Next, the produced hydrogen and oxygen were introduced into the hydrogen fuel cell of the hydrogen power generation unit (200) to produce electricity through an electrochemical reaction, and the produced electricity was transferred to a demand location (500, a residential apartment complex). In addition, the carbon byproduct generated in the hydrogen production unit (100) was transferred to the carbon material recovery unit and purified.

[0213] (3) Manufacturing of carbon material (graphene oxide) using carbon byproduct: The carbon byproduct was recovered from the hydrogen production unit (100) and transferred to the carbon material recovery unit. Then, in the carbon exfoliation unit, the carbon byproduct was contacted with sulfuric acid and potassium permanganate to recover the carbon component, and the potassium permanganate was removed by contacting the carbon component with hydrogen peroxide. Then, in the first purification unit, the carbon component was first purified with a strong acid at 50~80°C, and then in the second purification unit, the first purified carbon component was secondarily purified with 10% hydrogen fluoride (HF) at 60°C to obtain carbon oxide (graphene oxide).

[0214] (4) Preparation of carbon material (reduced graphene oxide) using carbon byproduct: The carbon oxide was first reduced in a first reduction unit with a reducing solution (hydrazine (N2H4) aqueous solution) at 100~180°C, and then the first reduced carbon oxide was secondarily reduced in a second reduction unit with sulfuric acid at 150~220°C to obtain reduced carbon oxide (reduced graphene oxide).

[0216] Example 2

[0217] (1) Configuration of a household distributed power system: A household distributed power system as shown in FIG. 2 was configured. Specifically, the household distributed power system (2000) is configured to include a gas supply line (10) through which city gas (LNG) is transported; a hydrogen production unit (100) that produces hydrogen and carbon by-products by pyrolyzing hydrocarbons; a hydrogen separation unit (110) that separates hydrogen from the hydrogen-containing gas using a pressure swing adsorption (PSA) method; a hydrogen storage unit (120) in which the separated hydrogen is stored; a hydrogen power generation unit (200) that produces electricity using the hydrogen; and an energy storage system unit (400) in which the electricity is stored. In addition, the household distributed power system (2000) is equipped with a renewable energy unit (300) that generates electricity using solar power to produce electrical energy and transports it to the hydrogen production unit (100), and the produced electricity is transported to a demand location (500, a household apartment complex). The hydrogen power generation unit (200) is configured by connecting one or more hydrogen fuel cells in parallel to generate power using hydrogen and oxygen.

[0218] The energy storage system unit (400) is configured to include a battery in which power transferred from the hydrogen power generation unit is stored, a battery management system (BMS) electrically connected to the battery and controlling the battery, a power conversion system (PCS) that converts the voltage characteristics of the power stored in the battery and transfers it to a demand source, and a total energy management system (EMS) electrically connected to and controlling the hydrogen production unit, hydrogen separation unit, hydrogen storage unit, hydrogen power generation unit, battery management system, and power conversion system, respectively.

[0219] The above total energy management system calculated the required amount of power using the power consumption data of the demand source and controlled the power conversion system to transfer power corresponding to the amount of power to the demand source. In addition, the carbon byproduct generated in the hydrogen production unit (100) was transferred to the carbon material recovery unit and purified. The carbon material recovery unit used was the same as that in Example 1.

[0220] (2) Power supply using a household distributed power system: Power was supplied (distributed supply) to demand locations using a household distributed power system (2000). Specifically, city gas (LNG) transferred from the gas supply line (10) to the hydrogen production unit (100) was pyrolyzed at 900°C under a red mud catalyst to produce hydrogen-containing gas and carbon byproducts. In the renewable energy unit (300), electrical energy was produced through solar power generation and used for the pyrolysis reaction in the hydrogen production unit (100). Then, the hydrogen-containing gas was transferred to the hydrogen separation unit (110), and hydrogen was separated by a pressure fluctuation adsorption method and stored in the hydrogen storage unit (120). The stored hydrogen was transferred to the hydrogen power generation unit (200), where electricity was produced by an electrochemical reaction using the hydrogen and oxygen in a hydrogen fuel cell. The produced electricity was stored in the battery of the energy storage system unit.

[0221] The above total energy management system calculated the required amount of power using the power consumption data of the above demand source and controlled the power conversion system to transfer power corresponding to the amount of power to the demand source (500). In addition, the carbon byproduct generated in the hydrogen production unit (100) was transferred to the carbon material recovery unit and purified.

[0222] Meanwhile, the energy for the thermal decomposition of city gas in Example 2 above can be mostly provided through renewable energy sources (residential solar power generation). The amount of electrical energy generated through the renewable energy sources and the energy required for thermochemical methane decomposition are as follows. At this time, the power demand (energy balance) was calculated based on an apartment complex of 1,000 households.

[0223] (1) Electricity consumption = 0.5kW (based on 1 household of 4 people) x 1,000 households, power consumption = 0.5MW

[0224] (2) Solar power generation = 400W x sunlight (5hr / day) x 1,000 households, power generation = 2,000kWh

[0225] (3) Decomposition of city gas (methane gas) 283 kmol x 37 kJ / mol (methane conversion rate 70%), heat of reaction = 2,035 kWh

[0226] Referring to (1) to (3) above, approximately 0.5 MW of hydrogen fuel cell power generation is required for an apartment complex of 1,000 households. To achieve this, 283 kmol of methane must be converted per day based on a methane conversion rate of 70%. At this time, the reaction heat required for hydrogen production is approximately 2,000 kWh. In other words, it can be seen that the electrical energy required for hydrogen production through pyrolysis can be mostly provided through renewable energy sources (residential solar power generation).

[0227] (3) Manufacturing of carbon material (graphene oxide) using carbon byproduct: The carbon byproduct was recovered from the hydrogen production unit (100) and transferred to the carbon material recovery unit. Then, in the carbon exfoliation unit, the carbon byproduct was contacted with sulfuric acid and potassium permanganate to recover the carbon component, and the potassium permanganate was removed by contacting the carbon component with hydrogen peroxide. Then, in the first purification unit, the carbon component was first purified with a strong acid at 50~80°C, and then in the second purification unit, the first purified carbon component was secondarily purified with 10% hydrogen fluoride (HF) at 60°C to obtain carbon oxide (graphene oxide).

[0228] (4) Preparation of carbon material (reduced graphene oxide) using carbon byproduct: The carbon oxide was first reduced in a first reduction unit with a reducing solution (hydrazine (N2H4) aqueous solution) at 100~180°C, and then the first reduced carbon oxide was secondarily reduced in a second reduction unit with sulfuric acid at 150~220°C to obtain reduced carbon oxide (reduced graphene oxide).

[0230] The present invention has been described above with reference to embodiments. Those skilled in the art will understand that the present invention may be embodied in modified forms without departing from the essential characteristics of the invention. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the invention is defined by the claims, not by the foregoing description, and all variations within the scope of equivalents should be interpreted as being included in the invention. Explanation of the symbols

[0232] 10: Gas supply line 100: Hydrogen production unit 110: Hydrogen separation unit 120: Hydrogen storage unit 200: Hydrogen Power Division 300: Renewable Energy Division 400: Energy Storage System Section 1000, 2000: Residential distributed power system

Claims

Claim 1 A household distributed power generation system comprising: a hydrogen production unit that generates hydrogen and carbon by-products by thermally decomposing hydrocarbons; a hydrogen power generation unit that generates electricity using the hydrogen; and a carbon material recovery unit that generates carbon materials by purifying the carbon by-products; wherein the carbon material recovery unit includes a carbon stripping unit that recovers carbon components by contacting the carbon by-products with a strong acid and potassium permanganate (KMnO4), a primary purification unit that performs primary purification of the carbon components with a strong acid or a strong base, and a secondary purification unit that obtains carbon oxides by secondary purification of the primary purified carbon components with hydrogen fluoride (HF); wherein the generated electricity is transferred to a demand source; wherein the hydrogen production unit is equipped with a catalyst, and the catalyst includes a red mud catalyst; and wherein the thermal decomposition is carried out at 850 to 950°C. Claim 2 A household distributed power generation system comprising: a hydrogen production unit that generates hydrogen-containing gas and carbon by-products by thermally decomposing city gas; a hydrogen separation unit that separates hydrogen from the hydrogen-containing gas; a hydrogen power generation unit that generates electricity using the hydrogen; an energy storage system unit in which the electricity is stored; and a carbon material recovery unit that purifies the carbon by-products to generate carbon materials; wherein the carbon material recovery unit includes a carbon stripping unit that recovers carbon components by contacting the carbon by-products with a strong acid and potassium permanganate (KMnO4), a primary purification unit that purifies the carbon components with a strong acid or a strong base, and a secondary purification unit that obtains carbon oxides by purifying the primary purified carbon components with hydrogen fluoride (HF); wherein the stored electricity is transferred to a demand source; wherein the hydrogen production unit is equipped with a catalyst, and the catalyst includes a red mud catalyst; and wherein the thermal decomposition is carried out at 850 to 950°C. Claim 3 A household distributed power system, wherein, in either of paragraphs 1 and 2, it further comprises a renewable energy unit that produces electrical energy using one or more renewable energy sources selected from hydropower, wind power, and solar power, and wherein the produced electrical energy is transferred to a hydrogen production unit and used for pyrolysis. Claim 4 delete Claim 5 A household distributed power system according to either claim 1 or claim 2, wherein the hydrogen power generation unit comprises one or more hydrogen fuel cells that produce electricity using hydrogen and oxygen. Claim 6 delete Claim 7 A household distributed power system according to claim 1, wherein the carbon material recovery unit further comprises a first reduction unit that first reduces the carbon oxide using a reducing solution and a second reduction unit that secondarily reduces the first reduced carbon oxide using sulfuric acid to obtain reduced carbon oxide. Claim 8 In paragraph 2, the hydrogen separation unit separates hydrogen from a hydrogen-containing gas using a pressure swing adsorption (PSA) method, in a household distributed power system. Claim 9 A household distributed power system according to paragraph 2, wherein the hydrogen separation unit separates hydrogen and city gas from a hydrogen-containing gas, and the city gas flows into a gas supply line and flows into the hydrogen production unit. Claim 10 A household distributed power system further comprising, in paragraph 2, a hydrogen storage unit in which hydrogen is transferred from the hydrogen separation unit and stored. Claim 11 In paragraph 2, the energy storage system comprises a battery in which power is stored, a battery management system (BMS) electrically connected to the battery and controlling the battery, a power conversion system (PCS) that converts the voltage characteristics of the power stored in the battery and transmits it to a demand source, and a total energy management system (EMS) electrically connected to and controlling the battery management system and the power conversion system, thereby forming a household distributed power system. Claim 12 In claim 11, the total energy management system is a household distributed power system that calculates the required amount of power using power consumption data of the demand location and controls a power conversion system to transfer power corresponding to the amount of power to the demand location. Claim 13 delete Claim 14 delete Claim 15 delete Claim 16 delete Claim 17 delete Claim 18 delete Claim 19 delete Claim 20 delete Claim 21 A method for recovering carbon materials, comprising: a step of recovering carbon by-products recovered by pyrolyzing hydrocarbons or city gas under a catalyst and contacting them with a strong acid and potassium permanganate (KMnO4) to recover carbon components; a step of first purifying the carbon components by treating them with a strong acid or a strong base at 50 to 80°C; and a step of secondarily purifying the first purified carbon components by treating them with hydrogen fluoride (HF) at 40 to 60°C to obtain carbon oxides; wherein the catalyst comprises a red mud catalyst, and the pyrolysis is carried out at 850 to 950°C. Claim 22 A method for recovering carbon materials, comprising: a step of recovering carbon by-products recovered by pyrolyzing hydrocarbons or city gas under a catalyst and contacting them with a strong acid and potassium permanganate (KMnO4) to recover carbon components; a step of first purifying the carbon components by treating them with a strong acid or a strong base at 50 to 80°C; a step of secondarily purifying the firstly purified carbon components by treating them with hydrogen fluoride (HF) at 40 to 60°C to obtain carbon oxides; a step of firstly reducing the carbon oxides using a reducing solution; and a step of secondarily reducing the firstly reduced carbon oxides using sulfuric acid to obtain reduced carbon oxides; wherein the catalyst comprises a red mud catalyst, and the pyrolysis is carried out at 850 to 950°C. Claim 23 Carbon material recovered by the carbon material recovery method of paragraph 21. Claim 24 Carbon material recovered by the carbon material recovery method of Paragraph 22.

Images