SYSTEMATIC METHOD FOR REDUCING CARBON EMISSIONS THROUGHOUT THE PRODUCTION AND FOUNDRY PROCESS

Description

1 / 17 SYSTEMATIC METHOD FOR REDUCING CARBON EMISSIONS THROUGHOUT THE PRODUCTION AND FOUNDRY PROCESS Field of Invention

[0001] The present invention relates to the field of iron and steel metallurgy and, in particular, to a systematic method of carbon reduction for the entire steelmaking and casting process. Description of the state of the art

[0002] To address global climate change, reducing carbon dioxide (CO2) emissions and achieving low-carbon production have become the focus of social attention. The steel industry, which is highly energy-intensive, is one of the largest carbon emitters among the 31 categories of the manufacturing industry. In 2022, crude steel production in China reached 1.013 billion tons, the highest in the world, with CO2 emissions of 2.1 billion tons, representing approximately 15-17% of the country's total carbon emissions. The blast furnace conversion process, based on carbon and iron ore metallurgy, accounts for about 90% of total steel production. Among these processes, blast furnace iron production is the process with the highest CO2 emissions, accounting for 70-90% of total CO2 emissions in all iron and steel production.The use of hydrogen to replace carbon as much as possible as a reducing agent and fuel in the iron manufacturing process—with the product of hydrogen's participation in the reaction being water—can significantly reduce CO2 emissions and, fundamentally, achieve low-carbon smelting in blast furnaces. The application of green hydrogen in hydrogen-enriched low-carbon smelting in blast furnaces has become a research focus for transformative technologies in the iron and steel manufacturing process. Meanwhile, to further achieve the comprehensive and effective utilization of waste heat and energy throughout the... Petition 870250083950, dated 09 / 18 / 2025, page 11 / 70 2 / 17 In order to achieve the lowest possible energy consumption while also conserving energy and reducing carbon emissions, a new system needs to be built and optimized. Furthermore, the hydrogen currently used in factories is mainly a byproduct obtained from coke oven gas separation, while hydrogen production by water electrolysis requires a large amount of electrical energy. Therefore, it is necessary to introduce stable green energy into the carbon-free iron and steel smelting process to produce enough hydrogen to truly achieve the goal of carbon reduction throughout the process. At the same time, the current perspective on carbon reduction focuses mainly on the source and production process of iron and steel, ignoring the effect of carbon sequestration from the final products. Summary of the invention

[0003] To address the aforementioned problems, the present invention provides a systematic method for reducing carbon emissions for the entire production and smelting process, comprising the steps of: injecting hydrogen into a blast furnace; where the hydrogen comes from a nuclear-based hydrogen production system, a water electrolysis hydrogen production system, and a gas-steam reforming hydrogen production system in a coke oven; wherein the nuclear-based hydrogen production system comprises a nuclear power generation subsystem, a hydrogen production thermal cycle subsystem, and a hydrogen-enriched blast furnace converter subsystem; where the nuclear power generation subsystem generates electricity via a high-temperature helium Brayton / Rankine cycle and supplies steam to the hydrogen production thermal cycle subsystem; in which a thermochemical reaction occurs in the production cycle system of Petition 870250083950, dated 09 / 18 / 2025, page 12 / 70 3 / 17 Nuclear-heated hydrogen to produce hydrogen and oxygen; the hydrogen is heated within the nuclear heating cycle system, while the oxygen releases heat within the same system; the high-temperature hydrogen and low-temperature oxygen, after conversion into thermal energy, are introduced into the hydrogen-enriched blast furnace converter subsystem; where the electrical energy consumed by the hydrogen production system through water electrolysis comes from gas-fired power generation, residual vapor pressure power generation, solar power generation, wind power generation, and off-peak electricity from the power grid; where the combustible gases used for gas-fired power generation are coke oven gas, blast furnace gas, and converter gas; where the steam for generating residual steam pressure power comes from a sintering waste heat boiler; where the steam for hydrogen production by gas-steam reforming in a coke oven is low-pressure exhaust steam from residual pressure power generation; Production of finished products comprising cast steel profiles and casting materials, including high-carbon ductile cast iron profiles with a carbon content of 2-4% and a silicon content of 2-4%, and high-carbon ductile cast steel profiles with a carbon content of 1-2% and a silicon content of 1-1.9%; and recycling of scrap from finished products in a converter or electric arc furnace for casting.

[0004] In addition, the nuclear power generation subsystem comprises a nuclear reactor, a first steam turbine, a first generator, a steam generator, a first compressor, a second steam turbine, a second generator, a condenser, a condensate pump, a low-pressure heater, a deaerator, a feedwater pump and a high-pressure heater; Petition 870250083950, dated 09 / 18 / 2025, page 13 / 70 4 / 17 The high-temperature helium output from the nuclear reactor is directed to the first steam turbine and the hydrogen production thermal cycle subsystem; the high-temperature helium expands in the first steam turbine to perform work, driving the first generator to generate electricity; the first steam turbine discharges low-pressure helium to the steam generator; Low-pressure helium transfers its thermal energy in the steam generator to convert industrial water into steam via a Rankine cycle, with the steam being fed to the second steam turbine; the low-temperature, low-pressure helium is compressed by the first compressor and returned to the nuclear reactor as a reactor coolant for recirculation; A portion of the steam from the second steam turbine is extracted and directed to the hydrogen production thermal cycle subsystem; the remaining steam expands in the second steam turbine to perform work, driving the second generator to generate electricity, and is then discharged into the condenser; the electricity generated by the second generator is supplied to the hydrogen production thermal cycle subsystem; The condensate from the condenser is pressurized by the condensate pump and, combined with the industrial wastewater supplied by the hydrogen-enriched blast furnace converter subsystem, passes sequentially through the low-pressure heater, the deaerator, the feedwater pump, and the high-pressure heater before entering the tube side of the steam generator, where oxygen and other gases are removed from the water, thus serving as partial feedwater for the Rankine steam cycle.

[0005] In addition, the hydrogen production thermal cycle subsystem comprises a first pressure reducing valve, a second pressure reducing valve, a hydrogen and oxygen production unit of the iodine-sulfur cycle, a gas mixing chamber, a high-temperature, low-pressure heater, and a temperature control system; Petition 870250083950, dated 09 / 18 / 2025, page 14 / 70 5 / 17 The high-temperature helium output from the nuclear reactor is directed to the second pressure-reducing valve, while a portion of the steam extracted from the second steam turbine is directed to the first pressure-reducing valve; both streams are reduced to the operating pressure of the hydrogen and oxygen production unit of the iodine-sulfur cycle; the high-temperature helium and the high-temperature steam output jointly provide thermal energy to the hydrogen and oxygen production unit of the iodine-sulfur cycle, with the high-temperature steam further supplementing the steam required for thermochemical reactions in said unit; The hydrogen and oxygen production unit of the iodine-sulfur cycle undergoes thermochemical reactions to produce hydrogen and oxygen at high temperatures; the high-temperature hydrogen produced enters the gas mixing chamber and combines with coke oven gas and carbon monoxide generated by the hydrogen-enriched blast furnace converter subsystem to form a high-temperature reducing atmosphere; this atmosphere exchanges heat in the low-pressure, high-temperature heater with high-temperature helium that has passed through the second pressure-reducing valve and the temperature control system to achieve stable pressure and temperature conditions, before being introduced into the hydrogen-enriched blast furnace converter subsystem; High-temperature oxygen releases heat through the low-pressure heater and the high-pressure heater, and after conversion into thermal energy, it is introduced into the hydrogen-enriched blast furnace converter subsystem.

[0006] In addition, the hydrogen-enriched blast furnace converter subsystem comprises a hydrogen-enriched blast furnace, a converter, a slag waste heat recovery device, a third generator, and a higher-quality gas purification unit; the higher-quality gas purification unit comprises a desulfurization tower, a capture tower, a tower of Petition 870250083950, dated 09 / 18 / 2025, page 15 / 70 6 / 17 regeneration, a dust remover, a high-quality gas dechlorination and desulfurization wastewater treatment device, a second compressor, and a carbon dioxide storage tank; The high-temperature reducing atmosphere produced facilitates reduction reactions in the hydrogen-enriched blast furnace, producing pig iron that is charged into the converter; low-temperature oxygen is introduced into both the hydrogen-enriched blast furnace and the converter to facilitate oxidation reactions, producing steel products; simultaneously, waste heat from the slag is recovered by the slag waste heat recovery device, using a Kalina cycle power generation system to convert thermal energy into electrical energy, allowing the third generator to generate electricity to power the high-quality gas purification unit and the high-quality gas dechlorination and desulfurization wastewater treatment device; The high-quality gas discharged from the hydrogen-enriched blast furnace passes through the dust remover and then enters the high-quality gas purification unit, where it flows sequentially through the desulfurization tower, the capture tower, and the regeneration tower before the remaining gaseous components are discharged into the atmosphere; The high-quality gas fed into the desulfurization tower of the high-quality gas purification unit produces blast gas scrubbing wastewater, which is directed to the condensate pump for circulation to supply the industrial water needed for the hydrogen and oxygen production unit of the iodine-sulfur cycle; The capture tower captures carbon monoxide and feeds it into the gas mixing chamber to recirculate and supplement the reducing atmosphere; The regeneration tower extracts carbon dioxide and feeds it into the second compressor and the carbon dioxide storage tank. Petition 870250083950, dated 09 / 18 / 2025, page 16 / 70 7 / 17

[0007] In addition, the carbon dioxide (CO2) produced by the combustion of coke oven gas, blast furnace gas and converter gas in the gas-fired power generation process is captured by carbon capture technology and subsequently stored.

[0008] In addition, the electrical energy generated by gas-fired power generation, residual vapor pressure power generation, solar power generation, wind power generation and nuclear power generation is integrated into an internal electrical grid of the steel plant and transmitted to the hydrogen production equipment by water electrolysis.

[0009] In addition, the steam generated by the sintering waste heat boiler is fed into a high-pressure steam pipeline and delivered to the waste pressure power generation unit.

[0010] In addition, the low-pressure steam exhausted from the waste pressure power generation unit is conveyed via a low-pressure steam pipeline to the reaction furnace for hydrogen production by gas-steam reforming in a coke oven.

[0011] The present invention achieves carbon reduction at the source by injecting hydrogen into the blast furnace to replace fossil fuels as much as possible, thereby reducing the carbon input into the steel production process. This substitution of hydrogen for carbon reduces carbon emissions per unit of product by approximately 20% at the source. Simultaneously, by using high-carbon cast iron profiles and ductile cast steel profiles to replace traditional steels for construction and machinery, the carbon introduced into the steel production process is sequestered from the end products. These high-carbon end products will subsequently be recycled as scrap iron and scrap steel in electric arc furnaces and in converter steel production, preventing their release as carbon dioxide and thus achieving a carbon sequestration rate in Petition 870250083950, dated 09 / 18 / 2025, page 17 / 70 8 / 17 final product exceeding 25%. Furthermore, the invention introduces a nuclear hydrogen production system aligned with the aforementioned process, which completely eliminates the carbon footprint at the source through nuclear hydrogen generation. It also allows for the comprehensive utilization of waste heat and byproducts throughout the steel production process: waste heat from sintering is used to generate steam; the steam is used simultaneously for hydrogen production reforming and waste pressure power generation; and the exhausted steam from waste pressure power generation is subsequently employed for reforming with coking furnace gas to produce hydrogen. This systematically integrates and maximizes the use of various resources within the steel production workflow, thus achieving systematic carbon reduction throughout the steelmaking and casting process, from source to end.

[0012] The following description will further elucidate the concept, specific structure and technical effects of the present invention in conjunction with the accompanying drawings, to fully illustrate the objectives, features and advantages of the invention. Brief Description of the Drawings

[0013] Figure 1 is a process flow diagram of the systematic carbon reduction method for the entire steel production and casting process according to the present invention.

[0014] Figure 2 is a process flow diagram of the nuclear hydrogen production system of the method of the present invention. Detailed Description of the Modalities

[0015] A plurality of preferred embodiments of the present invention are described below with reference to the drawings, which makes its technical content clearer and easier to understand. The present invention can be carried out in many different embodiments, and the scope of protection of the present invention is not limited to the embodiments set forth herein. Petition 870250083950, dated 09 / 18 / 2025, p. 18 / 70 9 / 17

[0016] As shown in Figure 1, the systematic decarbonization method for the entire steelmaking and casting process, according to the present invention, comprises mainly two components: carbon reduction at the source and carbon sequestration in the final product. Carbon reduction at the source involves injecting hydrogen into the blast furnace during the ironmaking process, where hydrogen is used to replace carbon as much as possible, both as a reducing agent and as a fuel. This approach reduces the introduction of carbon into the steelmaking process at the source. Carbon sequestration in the final product, on the other hand, refers to the production of high-carbon cast iron profiles (carbon content: 2-4%) and ductile cast steel profiles (silicon content: 1-1.9%, carbon content: 1-2%) through steelmaking in an electric arc furnace.These products serve as final materials, replacing conventional construction steels (carbon content: ~0.2%), thus sequestering more carbon from the final products. In this way, the objective of low-carbon steel production is achieved through carbon sequestration in the final product.

[0017] Continuing with reference to Figure 1, it can be observed that, in the method of the present invention, the hydrogen used for hydrogen injection in a blast furnace comes mainly from two sources: hydrogen production by water electrolysis and hydrogen production by gas-steam reforming in a coke oven. The electrical energy consumed in water electrolysis for hydrogen production can come from nuclear power generation, gas-fired power generation, residual vapor pressure power generation, and off-peak grid electricity. The fuel gases used for gas-fired power generation are, respectively, coke oven gas from the coking process in steelmaking coke ovens, blast furnace gas from the blast furnace steelmaking process, and converter gas from the converter steelmaking process. Among these, the fuel components of coke oven gas are hydrogen (55% to 60%) and methane (23% to 27%), along with a Petition 870250083950, dated 09 / 18 / 2025, p. 19 / 70 10 / 17 small amount of carbon monoxide (5% to 8%); the fuel component of blast furnace gas is carbon monoxide, representing approximately 25%; and the fuel component of converter gas is carbon monoxide, with a content of 60-80%. The CO2 produced after the combustion of coke oven gas, blast furnace gas, and converter gas can be captured and stored using carbon capture technology. Waste pressure steam power generation utilizes backpressure units to convert thermal energy into electrical energy, taking advantage of steam pressure differences. Steam for waste pressure power generation is recovered from high-temperature flue gases in the sintering process using waste heat boilers and is transported to the waste pressure power generation unit via high-pressure steam pipelines for electricity generation.Coke oven gas-steam reforming for hydrogen production involves reacting coke oven gas with steam to generate hydrogen and carbon monoxide, which are then converted and separated to obtain hydrogen. Here, coke oven gas is a byproduct of the coking process in steel mills, while steam can come directly from waste heat boilers or from low-pressure steam after waste pressure power generation. Low-pressure steam is transported to the reaction furnace for coke oven gas-steam reforming via low-pressure steam pipelines. Based on hydrogen production by water electrolysis and coke oven gas-steam reforming, along with hydrogen injection into the blast furnace, carbon emissions per ton of product can be reduced by 25% from the source.

[0018] In practical production, the enormous amount of hydrogen needed for injection requires substantial electrical energy consumption for hydrogen production through water electrolysis. If the electricity for electrolysis still comes from coal-fired power generation, a truly green metallurgy cannot be achieved. Petition 870250083950, dated 09 / 18 / 2025, page 20 / 70 11 / 17 achieved.

[0019] Therefore, in another embodiment of the present invention, a nuclear-based hydrogen production system is provided. The system comprises a nuclear power generation subsystem, a hydrogen production thermal cycle subsystem, and a hydrogen-enriched blast furnace converter subsystem. The nuclear power generation subsystem employs a high-temperature helium Brayton / Rankine cycle for power generation and supplies steam to the hydrogen production thermal cycle subsystem. Within the nuclear-heated hydrogen production cycle system, a thermochemical reaction occurs to produce hydrogen and oxygen. The hydrogen is heated using thermal and electrical energy in the nuclear heating cycle system, while the oxygen releases waste heat.After conversion into thermal energy, the high-temperature hydrogen and low-temperature oxygen are introduced into the hydrogen-enriched blast furnace converter subsystem, where they are used to create a reducing-oxidative atmosphere.

[0020] As shown in Figure 2, the nuclear power generation subsystem comprises a nuclear reactor (1), a first steam turbine (2), a first generator (3), a steam generator (4), a first compressor (5), a second steam turbine (7), a second generator (8), a condenser (9), a condensate pump (10), a low-pressure heater (11), a deaerator (12), a feedwater pump (13) and a high-pressure heater (14).

[0021] The hydrogen production thermal cycle subsystem includes a first pressure reducing valve (6), a second pressure reducing valve (15), a hydrogen and oxygen production unit of the iodine-sulfur cycle (16), a gas mixing chamber (17), a high temperature and low pressure heater (18) and a temperature control system (19).

[0022] The nuclear reactor (1) discharges high-temperature helium at 900-1000 °C and 7-8 Petition 870250083950, dated 09 / 18 / 2025, page 21 / 70 12 / 17 MPa. The high-temperature helium pipelines are constructed of 310S austenitic stainless steel containing Al. The helium is then directed to the first steam turbine (2) of the nuclear power generation subsystem and to the second pressure reducing valve (15) of the hydrogen production thermal cycle subsystem.

[0023] A portion of the high-temperature helium gas entering the nuclear power generation subsystem expands in the first steam turbine (2) to perform work, driving the first generator (3) to generate electricity. The first steam turbine (2) discharges low-pressure helium to the steam generator (4). The temperature of the low-pressure helium—formed by mixing the output of the first steam turbine (2) and the low-pressure helium recirculated from the hydrogen production thermal cycle subsystem—varies from 600 °C to 700 °C. In the steam generator (4), the thermal energy of the low-pressure helium is transferred via a Rankine cycle to convert industrial water into steam, which is then fed to the second steam turbine (7). Simultaneously, low-temperature, low-pressure helium, between 300 °C and 400 °C, is discharged to the first compressor (5).The first compressor (5) compresses this helium and delivers it back to the nuclear reactor (1) at a temperature of 350°C to 450°C.

[0024] Industrial water, after being heated by low-pressure helium, is converted into steam in the steam generator (4). A portion of this steam is extracted from the second steam turbine (7) and directed to the first pressure reducing valve (6) of the hydrogen production thermal cycle subsystem. After pressure reduction, the steam is supplied to the hydrogen and oxygen production unit of the iodine-sulfur cycle (16). The remaining steam expands in the second steam turbine (7) to drive the second generator (8) for power generation and is then discharged into the condenser (9). The electricity generated by the second generator (8) is supplied to the temperature control system (19) of the hydrogen production thermal cycle subsystem. The condensate resulting from the condenser (9) is pressurized by the pump. Petition 870250083950, dated 09 / 18 / 2025, page 22 / 70 13 / 17 condensate (10) and, in combination with industrial wastewater supplied by the hydrogen-enriched blast furnace converter subsystem, passes sequentially through the low-pressure heater (11), deaerator (12), feedwater pump (13) and high-pressure heater (14). The resulting feedwater then enters the tubular side of the steam generator (4) to form the feedwater for the Rankine cycle.

[0025] The nuclear reactor (1) discharges the remaining high-temperature helium to the second pressure reducing valve (15) for pressure reduction. The said reduced-pressure helium, together with the steam depressurized by the first pressure reducing valve (6), provides the thermal energy required for the hydrogen and oxygen production unit of the iodine-sulfur cycle (16), which operates at a working temperature of 800-900 °C and a working pressure of 4-5 MPa. The high-temperature steam simultaneously serves to supplement the water required for the thermochemical reaction in the said hydrogen and oxygen production unit of the iodine-sulfur cycle (16). Within the said unit (16), a thermochemical reaction occurs to produce high-temperature hydrogen and oxygen, comprising the steps of: Bunsen reaction (20-120 °C): SO2 + 2H2O → 2HI + H2SO4 Decomposition reaction of hydroiodic acid (400-500 °C): 2HI ^ I2 + H2 Decomposition reaction of sulfuric acid (800-900 °C): H2SO4 + SO2 + H2O + 102

[0026] Considering the high temperature conditions and acid corrosion problems, the hydrogen and oxygen production unit of the iodine-sulfur cycle (16) and its associated piping are constructed of 310S austenitic stainless steel containing Al. Petition 870250083950, dated 09 / 18 / 2025, page 23 / 70 14 / 17 The high-temperature produced hydrogen gas enters the gas mixing chamber (17), where it combines with coke oven gas and carbon monoxide from the higher-quality gas purification unit (24) of the hydrogen-enriched blast furnace converter subsystem, forming a high-temperature reducing atmosphere. This atmosphere is then heated to 950-1050 °C in a high-temperature, low-pressure heater (18) made of GH3536 nickel alloy, by means of thermal energy exchange with high-temperature helium (1000-1100 °C) that has passed through the second pressure reducing valve (15) and has been electrically heated by the temperature control system (19). The heated reducing atmosphere is subsequently introduced into the hydrogen-enriched blast furnace converter subsystem. After the thermal energy transfer, the helium temperature drops to 750-850 °C.This cooled helium fuses with the low-temperature helium (300-500 °C) that has undergone heat loss in the hydrogen and oxygen production unit of the iodine-sulfur cycle (16), finally forming helium at 600-700 °C for recirculation in the nuclear power generation subsystem. Meanwhile, the high-temperature oxygen releases heat through the low-pressure heater (11) and the high-pressure heater (14). After this thermal energy conversion, the oxygen is introduced into the hydrogen-enriched blast furnace converter subsystem for recycling.

[0027] The hydrogen-enriched blast furnace converter subsystem comprises: a hydrogen-enriched blast furnace (20), a converter (21), a waste heat recovery device for slag (22), a third generator (23), a higher quality gas purification unit (24), a dust remover (25), a wastewater treatment device for dechlorination and desulfurization of higher quality gas (26), a second compressor (27) and a carbon dioxide storage tank (28).

[0028] The high-temperature reducing atmosphere produced by the hydrogen production thermal cycle subsystem is injected through the lower shaft or region of Petition 870250083950, dated 09 / 18 / 2025, page 24 / 70 15 / 17 Bosch hydrogen-enriched blast furnace (20). The gas pipelines and gas flow distribution device inside the furnace are constructed of nickel-based alloy GH3536. Reduction reactions occur in the hydrogen-enriched blast furnace (20), producing pig iron that is charged into the converter (21). Low-temperature oxygen is introduced into both the hydrogen-enriched blast furnace (20) and the converter (21) to facilitate oxidation reactions. During the production of steel products, waste heat from the slag is recovered by the waste heat recovery device (22). Using a Kalina cycle power generation system, thermal energy is converted into electrical energy, allowing the third generator (23) to generate electricity.The energy generated is supplied to operate the high-quality gas purification unit (24) and the wastewater treatment device for dechlorination and desulfurization of high-quality gas (26).

[0029] The high-quality gas generated by the reduction and oxidation reactions in the hydrogen-enriched blast furnace (20) passes sequentially through the dust remover (25) and the high-quality gas purification unit (24), after which the remaining harmless gaseous components are discharged into the atmosphere.

[0030] The high-quality gas purification unit (24) comprises a desulfurization tower (241), a capture tower (242), and a regeneration tower (243). The desulfurization tower (241) is in communication with the capture tower (242), the dust collector (25), and the wastewater treatment device for dechlorination and desulfurization of high-quality gas (26). The wastewater treatment device for dechlorination and desulfurization of high-quality gas (26) is in communication with the condensate pump (10). The capture tower (242) is in communication with the regeneration tower (243) and the gas mixing chamber (17). The regeneration tower (243) is in communication with the second compressor (27). Petition 870250083950, dated 09 / 18 / 2025, page 25 / 70 16 / 17

[0031] The high-quality gas, after passing through the dust collector (25), enters the desulfurization tower (241), where toxic components, including hydrogen chloride, carbonyl sulfide, and hydrogen sulfide, are removed. The effluent from the washing of the resulting high-quality gas is treated by the wastewater treatment device for dechlorination and desulfurization of the high-quality gas (26) and then enters the condensate pump (10), where it is used as industrial water for the Rankine cycle, thus achieving circular utilization. The preliminarily purified high-quality gas subsequently passes through the capture tower (242), where carbon monoxide is captured and transported to the gas mixing chamber (17) for recirculation, regulating and supplementing the reducing atmosphere. Finally, the still purified high-quality gas enters the regeneration tower (243), where carbon dioxide is extracted.The captured carbon dioxide is fed into the second compressor (27) for compression and stored in the carbon dioxide storage tank (28) for use in other industries. The superior quality gas, finally purified and harmless, is then discharged.

[0032] The present invention achieves carbon reduction at the source by injecting hydrogen into the blast furnace to replace fossil fuels as much as possible, thereby reducing the carbon input into the steel production process from the outset. This substitution of hydrogen for carbon reduces carbon emissions per unit of product by approximately 20% at the source. Simultaneously, by using high-carbon cast iron profiles and ductile cast steel profiles to replace traditional steels for construction and machinery, the carbon introduced into the steel production process is sequestered in the end products. These high-carbon end products will subsequently be recycled as iron scrap and steel scrap in electric arc furnaces and in converter steel production, preventing their release as carbon dioxide and thus achieving a carbon sequestration rate in the end product of more than 25% per ton of product.Furthermore, the invention introduces... Petition 870250083950, dated 09 / 18 / 2025, page 26 / 70 17 / 17 a nuclear hydrogen production system aligned with the aforementioned process. This system completely eliminates the carbon footprint at the source through nuclear hydrogen generation and allows for the comprehensive utilization of waste heat and byproducts throughout the steel production process. For example, waste heat from sintering is recovered to generate steam; this steam is used simultaneously for hydrogen production reforming and for residual pressure power generation; subsequently, the exhausted steam from residual power generation is further employed for reforming with coking furnace gas to produce hydrogen. This approach systematically integrates and maximizes the use of various resources within the steel production workflow.Furthermore, the invention proposes the use of nuclear energy as the main source of green energy for hydrogen production through water electrolysis and, specifically, provides a system dedicated to hydrogen production based on nuclear energy. This integrated solution provides a systematic reduction of carbon throughout the steel manufacturing and casting process.

[0033] The foregoing has provided a detailed description of specific preferred embodiments of the present invention. It should be understood that those with common knowledge of the art, without creative effort, could make numerous modifications and variations based on the concept of the present invention. Therefore, any technical solutions that can be obtained by a person skilled in the art through logical analysis, reasoning, or limited experimentation based on existing technology, in accordance with the inventive concept, will be covered by the scope of protection defined by the claims. Petition 870250083950, dated 09 / 18 / 2025, p. 27 / 70

Claims

1 / 6 CLAIMS 1. Systematic method for reducing carbon emissions for the entire production and smelting process, characterized in that it comprises the steps of: hydrogen injection into a blast furnace; wherein the hydrogen comes from a nuclear-based hydrogen production system, a water electrolysis hydrogen production system and a gas-steam reforming hydrogen production system in a coke oven; wherein the nuclear-based hydrogen production system comprises a nuclear power generation subsystem, a hydrogen production thermal cycle subsystem and a hydrogen-enriched blast furnace converter subsystem;wherein, the nuclear power generation subsystem comprises a nuclear reactor (1), a first steam turbine (2), a first generator (3), a steam generator (4), a first compressor (5), a second steam turbine (7), a second generator (8), a condenser (9), a condensate pump (10), a low-pressure heater (11), a deaerator (12), a feedwater pump (13) and a high-pressure heater (14); the hydrogen production thermal cycle subsystem comprises a first pressure reducing valve (6), a second pressure reducing valve (15), a hydrogen and oxygen production unit of the iodine-sulfur cycle (16), a gas mixing chamber (17), a high-temperature, low-pressure heater (18) and a temperature control system (19);The hydrogen-enriched blast furnace converter subsystem comprises a hydrogen-enriched blast furnace (20), a converter (21), a slag waste heat recovery device (22), a third generator (23), a high-quality gas purification unit (24), a dust remover (25), a high-quality gas dechlorination and desulfurization wastewater treatment device (26), a second compressor (27) and a carbon dioxide storage tank (28); wherein, the nuclear reactor (1) produces high-temperature helium at 900-1000 °C and 7-8 MPa, which is directed to the first steam turbine (2) of the nuclear power generation subsystem and to the second pressure reducing valve (15) of the hydrogen production thermal cycle subsystem;High-temperature helium expands in the first steam turbine (2) to perform work, driving the first generator (3) to generate electricity, which is supplied to the hydrogen production system by water electrolysis; the low-pressure helium output from the first steam turbine (2) mixes with the recirculated low-pressure helium from the hydrogen production thermal cycle subsystem to form a flow at 600-700 °C, which is transported to the steam generator (4); the low-pressure helium transfers its thermal energy from the steam generator (4) to convert industrial water into steam by means of a Rankine cycle, the steam being fed to the second steam turbine (7); the helium is then exhausted as low-temperature, low-pressure helium at 300-400 °C to the first compressor (5); the helium is compressed in the first compressor (5) and returned to the nuclear reactor (1) at 350-450 °C;a portion of the steam generated by the steam generator (4) is directed to the first pressure reducing valve (6) of the hydrogen production thermal cycle subsystem and, after pressure reduction, to the hydrogen and oxygen production unit of the iodine-sulfur cycle (16); the remaining steam expands in the second steam turbine (7) to perform work, driving the second generator (8) to generate electricity, and is then discharged into the condenser (9); the electricity generated by the second generator (8) is supplied to the temperature control system (19) of the hydrogen production thermal cycle subsystem;The condensate from the condenser (9) is pressurized by the condensate pump (10) and, combined with the industrial wastewater supplied by the hydrogen-enriched blast furnace converter subsystem, passes sequentially through the low-pressure heater (11), the deaerator (12), the feedwater pump (13) and the high-pressure heater (14) before entering the tube side of the steam generator (4) as feedwater for the Rankine cycle; the high-temperature helium from the nuclear reactor (1), after being fed to the second pressure reducing valve (15) and having its pressure reduced, is introduced into the hydrogen and oxygen production unit of the iodine-sulfur cycle (16);together with the steam from the first pressure reducing valve (6) (after pressure reduction), it provides the thermal energy required for the hydrogen and oxygen production unit of the iodine-sulfur cycle (16) operating at 800-900 °C and 4-5 MPa, wherein the steam also serves to supplement the water required for the thermochemical reaction in said unit (16); the high-temperature hydrogen produced by the hydrogen and oxygen production unit of the iodine-sulfur cycle (16) enters the gas mixing chamber (17) and mixes with coke oven gas and carbon monoxide from the higher-quality gas purification unit (24) of the hydrogen-enriched blast furnace converter subsystem to form a high-temperature reducing atmosphere;The said atmosphere enters the high temperature and low pressure heater (18) and is heated to 950-1050 °C by means of heat exchange with helium at 1000-1100 °C which has passed through the second pressure reducing valve (15) and has been electrically heated by the temperature control system (19); the heated reducing atmosphere is then introduced into the hydrogen-enriched blast furnace converter subsystem; Petition 870250083950, dated 09 / 18 / 2025, page 30 / 70 4 / 6 after the transfer of thermal energy, the temperature of the helium drops to 750-850 °C; This cooled helium fuses with the low-temperature helium of 300-500 °C that has undergone heat loss in the hydrogen and oxygen production unit of the iodine-sulfur cycle (16), ultimately forming 600-700 °C helium which is recirculated in the nuclear power generation subsystem by mixing with the low-pressure helium output from the first steam turbine (2), and entering the steam generator (4);The high-temperature oxygen produced by the hydrogen and oxygen production unit of the iodine-sulfur cycle (16) releases heat through the high-pressure heater (14) and the low-pressure heater (11), undergoes thermal energy exchange with the feedwater entering the steam generator (4) and is then introduced into the hydrogen-enriched blast furnace converter subsystem; the high-temperature reducing atmosphere produced by the hydrogen production thermal cycle subsystem is injected into the hydrogen-enriched blast furnace (20) through the lower shaft or Bosch region; reduction reactions occur in the hydrogen-enriched blast furnace (20), producing pig iron which is charged into the converter (21); low-temperature oxygen is introduced into the hydrogen-enriched blast furnace (20) and the converter (21) to facilitate oxidation reactions, producing steel products;Simultaneously, the waste heat from the slag is recovered by the waste heat recovery device (22); using a Kalina cycle power generation system, thermal energy is converted into electrical energy, allowing the third generator (23) to generate electricity to power the higher quality gas purification unit (24) and the higher quality gas dechlorination and desulfurization wastewater treatment device (26); the higher quality gas generated by the reduction and oxidation reactions in the hydrogen-enriched blast furnace (20) passes sequentially through the dust remover (25) and the higher quality gas purification unit (24), after which the remaining harmless gaseous components are discharged into the atmosphere;The high-quality gas, after passing through the dust collector (25), is treated by the desulfurization tower (241) of the high-quality gas purification unit (24); the wastewater from the washing of the resulting high-quality gas is treated by the wastewater treatment device for dechlorination and desulfurization of high-quality gas (26) and then fed into the condensate pump (10) for reuse as industrial water in the Rankine cycle, achieving circular utilization; the electrical energy consumed by the hydrogen production system by water electrolysis is additionally derived from gas-fired power generation, waste steam pressure power generation, solar power generation, wind power generation and off-peak grid electricity; the fuel gases used for gas-fired power generation are coke oven gas, blast furnace gas and converter gas;The steam for power generation from waste steam pressure comes from sintering waste heat boilers; the steam for hydrogen production in the gas-steam reforming of the coke oven is low-pressure steam obtained after waste pressure power generation; the end products are cast steel profiles and foundry materials comprising high-carbon ductile cast iron profiles with a carbon content of 2-4% and a silicon content of 2-4%, and high-carbon ductile cast steel profiles with a carbon content of 1-2% and a silicon content of 1-1.9%; scrap from the end products is fed into the converter or electric arc furnaces for recycling and smelting.

2. Method according to claim 1, characterized in that the high-quality gas purification unit (24) comprises: a desulfurization tower (241), a capture tower (242), and a regeneration tower (243); wherein the desulfurization tower (241) is in fluid communication with the capture tower (242), the dust remover (25) and the wastewater treatment device for dechlorination and desulfurization of high-quality gas (26); the wastewater treatment device for dechlorination and desulfurization of high-quality gas (26) is in fluid communication with the condensate pump (10); the capture tower (242) is in fluid communication with the regeneration tower (243) and the gas mixing chamber (17); and the regeneration tower (243) is in fluid communication with the second compressor (27).

3. Method according to claim 2, characterized in that the higher quality gas is subsequently processed through the regeneration tower (243) to extract carbon dioxide; the extracted carbon dioxide is fed into the second compressor (27) for compression and subsequently stored in the carbon dioxide storage tank (28).

4. Method, according to claim 1, characterized in that the electrical energy generated by gas power generation, residual vapor pressure power generation, solar power generation and wind power generation is integrated into an internal electrical grid of the steel plant and transmitted to the hydrogen production equipment by water electrolysis.

5. A method according to claim 1, characterized in that the steam generated by a sintering waste heat boiler is integrated into a high-pressure steam pipeline and transmitted to a waste pressure power generation unit.

6. Method according to claim 1, characterized in that the low-pressure steam exhausted from the residual pressure power generation unit is transported through a low-pressure steam pipeline to a reaction furnace for hydrogen production by gas-steam reforming in a coke oven. Petition 870250083950, dated 09 / 18 / 2025, p. 33 / 70

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