A green electricity driven hydrogen-based shaft furnace steelmaking cogeneration method

Abstract

The application provides a green electricity-driven hydrogen-based shaft furnace steeling cogeneration method, and relates to the technical field of iron and steel metallurgy and energy collaborative utilization. The hydrogen-based shaft furnace steeling cogeneration method realizes the green electricity-driven hydrogen-based shaft furnace steeling cogeneration method through renewable power supply and dynamic management, water electrolysis hydrogen production and hydrogen purification storage, iron ore pretreatment, hydrogen-based shaft furnace reduction, tail gas circulation and steeling cogeneration, whole-process monitoring control, environmental protection resource circulation and safety guarantee design. The method is simple and easy to operate, uses green electricity as energy, and is provided with a device structure and a whole-process monitoring control device structure capable of stably operating hydrogen production by green electricity, and has the advantages of low cost, high safety rate, high production efficiency, and is beneficial to industrial large-scale production and popularization.

Description

Technical Field

[0001] This invention relates to the technical field of synergistic utilization of iron and steel metallurgy and energy, and in particular to a green electricity-driven hydrogen-based vertical shaft furnace co-production method for steelmaking. Background Technology

[0002] Traditional ironmaking processes nowadays suffer from severe carbon emissions: relying on coke and coal gas, carbon emissions per ton of iron can reach over 2 tons; for blast furnace processes, the utilization rate of decommissioned blast furnace slag is low. Secondly, hydrogen-based direct reduction technology is developing rapidly: natural gas-modified direct reduction of iron is commercialized, but fossil carbon emissions still occur; wind and solar power output is volatile, requiring rapid start-up and shutdown of electrolyzers and smooth hydrogen storage and transportation systems; existing hydrogen production-reduction coupling systems are mostly static designs, lacking dynamic scheduling and hydrogen storage strategies; and even if hydrogen storage devices exist, they are only static designs, and current technology is insufficient for the recovery and utilization of tail gas to manufacture industrial organic compounds.

[0003] For example, Chinese patent CN112899427A discloses a hydrogen vertical furnace ironmaking system and method using electric heating. It involves electrolyzing water in an electrolysis cell to generate hydrogen, which is then introduced into a hydrogen storage tank. The hydrogen is then heated through a heat exchanger and enters a mixing tank, where it undergoes gas-solid heat exchange and reduction reactions with iron-containing materials. This method clearly does not take into account the instability of green electricity or the need for electrical compensation for heating devices that require electricity. Furthermore, the hydrogen is not purified, and the design of full-process monitoring and control and safety devices is even more difficult to predict.

[0004] Although Chinese patent CN118835018A discloses a hydrogen-based vertical furnace direct reduction iron energy storage device, which is also a green electricity hydrogen production device, its heating method does not use a reforming heating furnace that burns natural gas. The electric arc plasma heater used is not suitable for green electricity drive, resulting in high energy consumption, high cost of hydrogen storage device, narrow applicability, and poor regulation capability of reduction process.

[0005] Chinese patent CN115058553A discloses a vertical shaft furnace reactor suitable for the direct reduction of iron with hydrogen and its application. It requires dividing the inner cavity into n independent reaction zones by vertical partition walls, such that these n reaction zones are distributed in a fan shape around the central axis of the furnace cavity, where n is an integer greater than or equal to 4. Therefore, it requires a special installation structure, which does not meet the technical requirements of large-scale industrial production. Furthermore, it requires adjusting the number and position of the reaction zones participating in the direct reduction of iron with hydrogen according to the supply of fresh hydrogen, making operation inconvenient and the control method not dynamic. Similarly, Chinese patent CN114000162A also requires a specially designed device structure, resulting in a complex structure and difficult operation. Moreover, it uses a method where part of the green electricity is used to produce hydrogen and part is converted into heat energy, without considering the technical requirements of the reduction process in vertical shaft ironmaking regarding the influence of hydrogen and furnace charge.

[0006] Therefore, there is an urgent need for a complete system that fully integrates renewable electricity to produce hydrogen, direct hydrogen reduction, and the synthesis of organic chemicals using recycled gases to improve the overall efficiency of energy utilization. Summary of the Invention

[0007] This invention addresses several technical problems in existing hydrogen-based shaft furnace ironmaking processes, including reliance on fossil fuel power, low coupling between hydrogen production and reduction processes, large fluctuations in furnace reduction temperature and atmosphere leading to pellet agglomeration, and low efficiency in utilizing tail gas and waste heat. Therefore, a green electricity-driven hydrogen-based shaft furnace co-production method for steelmaking is proposed, capable of solving these problems.

[0008] A green electricity-driven hydrogen-based vertical shaft furnace co-production method for steelmaking includes the following steps:

[0009] S1. Renewable power supply and dynamic management: Renewable power is generated from wind power and solar photovoltaic power, and is fed into the distributed energy management system DERMS via inverters and distribution transformers. DERMS dynamically schedules power according to grid electricity prices and energy demand.

[0010] S2. Hydrogen production and purification storage via water electrolysis: Hydrogen is produced by using renewable electricity to drive a water electrolysis unit; the produced hydrogen is purified of impurities by membrane separation and PSA, dried, and stored in a hydrogen storage system with safety devices.

[0011] S3. Iron ore pretreatment: Iron ore is pretreated by crushing, pelletizing, and drying to obtain pretreated pellets.

[0012] S4. Hydrogen-based vertical shaft furnace reduction: The pretreated pellets are fed into a multi-layer countercurrent hydrogen-based vertical shaft furnace, natural gas is introduced for reduction, sponge iron is obtained, and the tail gas is recovered.

[0013] S5. Tail gas recycling and co-production of steelmaking: using an electrically heated reformer to process the recovered tail gas into chemical products and synthesize industrial organic compounds.

[0014] S6. Full-process monitoring and control: DCS / SCADA system is used for monitoring and scheduling;

[0015] S7. Environmental protection and resource recycling: Reduce the circulating water consumption of industrial water treatment systems;

[0016] S8. Safety Design: Equipment, pipelines, and valves are designed to be explosion-proof. Hydrogen pipelines are equipped with leak sensors and forced ventilation systems, and are equipped with emergency shut-off valves.

[0017] Optionally, the S1's distributed energy management system DERMS needs to be configured with a lithium battery energy storage system to smooth out power output fluctuations and ensure system load stability when green electricity output fluctuates.

[0018] Optionally, the dynamic scheduling of S1 is as follows: full-load hydrogen production during off-peak electricity prices, and surplus electricity for peak shaving or sales during peak electricity prices.

[0019] Optionally, the S2 water electrolysis device uses a molecular sieve, the deep drying device uses a molecular sieve dryer, the hydrogen storage system includes a high-pressure cylinder group and a medium-pressure storage tank, and the safety devices include a safety relief valve, a flame arrester, and a leak sensor with a detection limit ≤1 vol%.

[0020] Optionally, the water electrolysis device of S2 can be a proton exchange membrane electrolyzer (PEM) or a solid oxide electrolyzer (SOEC).

[0021] Optionally, the iron ore pretreatment of S3 adopts a two-stage jaw crusher and hammer crusher, the pelletizer is a disc pelletizer, and the drying temperature is 100-120℃; the hydrogen-based vertical shaft furnace is 20-25m high and 5-6m in inner diameter, with intermittent slag discharge from the lower slag outlet, with each batch being 0.8-1m. 3 After the sponge iron is unloaded, it is slowly cooled to 300-400℃.

[0022] Optionally, the sinter of S3 is sinter with Fe ≥ 67wt.%, the average size of the crushed sinter is 3-10mm, the pellet size of the pretreated pellets is 5-15mm, the strength is ≥ 2.5kN / particle, and the moisture content is ≤ 5%.

[0023] Optionally, the temperature of the natural gas introduced into S4 is 800-900℃, the outlet temperature is 650-750℃, and the sponge iron reduction degree is ≥95%.

[0024] Optionally, in S5, an electrically heated reformer is used to process the recovered tail gas for chemical production, synthesizing industrial organic compounds. By utilizing steel tail gas resources, the gasification stage can be omitted, resulting in significant investment savings.

[0025] Optionally, the S6's DCS / SCADA system includes an energy management layer (EMS), a manufacturing execution layer (MES), and a process control layer (PCS). Each unit is interconnected via industrial Ethernet and OPC-UA, and features fault diagnosis and alarm linkage.

[0026] Optionally, the S6's DCS / SCADA system's energy management layer (EMS) updates renewable electricity output data in real time, and the process control layer (PCS) controls current fluctuations in the water electrolysis unit; fault linkage includes hydrogen storage replenishment when hydrogen production is interrupted, ORC load reduction when the waste heat boiler is under maintenance, and emergency ventilation shutdown when hydrogen leaks.

[0027] The above technical solution has at least the following advantages compared with the existing technology:

[0028] The above-mentioned solution proposes a green electricity-driven hydrogen-based vertical shaft furnace co-production method for ironmaking, which can solve the technical problems existing in the prior art, such as the reliance on fossil power as the energy source for hydrogen-based vertical shaft furnace ironmaking, the low coupling degree between hydrogen production and reduction processes, the large fluctuations in furnace reduction temperature and atmosphere that easily lead to pellet agglomeration, and the low efficiency of tail gas and waste heat utilization.

[0029] This invention enables stable access and efficient consumption of green electricity through renewable power supply and dynamic management, reduces the dependence of hydrogen electrolysis and steelmaking on fossil power, smooths out fluctuations in renewable energy output, and improves the overall energy utilization efficiency and operational reliability of the system.

[0030] This invention enables the stable supply of high-purity hydrogen to hydrogen-based shaft furnaces and steelmaking units under different load conditions through hydrogen production by water electrolysis and hydrogen purification and storage. This achieves effective decoupling between hydrogen production, storage and use, providing a safe and reliable reducing gas source for continuous reduction and steelmaking processes.

[0031] This invention enables iron ore pretreatment to meet the requirements of hydrogen-based vertical shaft furnace direct reduction process in terms of particle size, strength, and moisture content, improves the permeability of the furnace bed, reduces the risk of pellet breakage and agglomeration during reduction, and enhances the uniformity and stability of the reduction reaction.

[0032] This invention enables efficient direct reduction of iron ore under low-carbon and low-impurity conditions through hydrogen-based vertical furnace reduction, resulting in sponge iron with high reduction degree and high metallization rate, while significantly reducing carbon dioxide emissions and improving the level of green ironmaking.

[0033] This invention enables the full recovery and cascade utilization of high-temperature exhaust gas and residual hydrogen generated during the vertical furnace and steelmaking process through tail gas recycling and co-production of steelmaking, realizing waste heat power generation, steam co-production and hydrogen recycling, further reducing system energy consumption and improving economic efficiency.

[0034] This invention enables the coordinated operation and dynamic optimization scheduling of hydrogen production, reduction, steelmaking and energy recovery units through full-process monitoring and control, ensuring stable process parameters, reducing human error, and improving the automation and intelligence level of the system.

[0035] This invention enables the efficient recycling and reuse of water resources, exhaust gas, and solid by-products through environmentally friendly resource recycling, reducing emissions of waste gas, wastewater, and solid waste, and meeting the requirements of green, low-carbon, and clean production.

[0036] This invention, through its safety-enhancing design, enables the entire process of hydrogen production, transportation, storage, and use to have comprehensive leak-proof, explosion-proof, and emergency response capabilities, significantly improving the inherent safety level of the system and making it suitable for long-term stable industrial operation.

[0037] This invention utilizes green electricity and hydrogen as the main components throughout the entire process, employing an electrically heated reformer to process the recovered tail gas for chemical production, synthesizing industrial organic compounds. By utilizing steel tail gas resources, the gasification stage can be omitted, significantly saving investment and achieving both economic efficiency and reliability.

[0038] In summary, compared to traditional vertical shaft furnace hydrogen reduction of iron, the present invention creatively achieves a green electricity-driven hydrogen-based vertical shaft furnace co-production method for steelmaking through renewable power supply and dynamic management, water electrolysis for hydrogen production and hydrogen purification and storage, iron ore pretreatment, hydrogen-based vertical shaft furnace reduction, tail gas recycling and steelmaking co-production, full-process monitoring and control, environmental resource recycling, and safety assurance design. This method is simple and easy to operate, uses green electricity as an energy source, and is equipped with a device structure for stable hydrogen production and a full-process monitoring and control device structure. It is low in cost, high in safety, and high in production efficiency, which is conducive to large-scale industrial production and promotion. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic flowchart of a green electricity-driven hydrogen-based vertical shaft furnace steelmaking and co-production method according to the present invention. Detailed Implementation

[0041] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0042] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0043] In the embodiments of the present invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that when the distinction is not emphasized, their intended meanings are consistent.

[0044] In this embodiment of the invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.

[0045] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0046] A green electricity-driven hydrogen-based vertical shaft furnace co-production method for steelmaking, wherein the green electricity-driven hydrogen-based vertical shaft furnace co-production method combines Figure 1 Includes the following steps:

[0047] S1. Renewable Power Supply and Dynamic Management: Using wind power and solar photovoltaic power as the core renewable power sources, the power generated by wind farms and photovoltaic power stations is converted from DC to AC via inverters and then fed into the Distributed Energy Management System (DERMS) via distribution transformers. Simultaneously, a lithium battery energy storage system is configured to smooth out fluctuations in renewable power output and support rapid start-up and shutdown of subsequent water electrolysis units and load adjustments.

[0048] The Distributed Energy Management System (DERMS) collects grid electricity prices, renewable power output forecasts, and energy demand data for each part of the system in real time, and formulates dynamic scheduling strategies: during off-peak electricity price periods, it controls the full load of renewable power for water electrolysis to produce hydrogen; during peak electricity price periods, if there is surplus power in the system, it connects the surplus power to the grid to participate in peak shaving or sells it directly, ensuring the efficient use of green electricity and the economic balance of the system.

[0049] S2, Hydrogen production and hydrogen purification and storage by electrolysis of water: Hydrogen is produced by using the renewable electricity output from S1 to drive the water electrolysis device. The water electrolysis device is a proton exchange membrane electrolyzer or a solid oxide electrolyzer (SOEC) with rapid dynamic response capability and can withstand rapid load switching.

[0050] The water electrolysis unit first performs preliminary purification through membrane separation to remove most of the impurities such as N2; then it uses pressure swing adsorption (PSA) process for deep purification. The purified hydrogen is compressed by a three-stage reciprocating compressor. During the compression process, the hydrogen pressure and temperature are monitored in real time to avoid overpressure and overtemperature; then it is sent to a deep drying unit.

[0051] The dried hydrogen is stored in a hydrogen storage system, which includes a high-pressure cylinder group and a medium-pressure storage tank to achieve hydrogen buffering and peak-valley regulation. At the same time, the hydrogen storage system is equipped with a safety pressure relief valve, a flame arrester and a hydrogen leakage monitoring sensor to ensure the safety of hydrogen storage.

[0052] S3. Iron ore pretreatment: A two-stage jaw crusher is used for coarse crushing to a particle size ≤50mm; then a hammer crusher is used for fine crushing to a particle size ≤20mm; the crushed ore is then processed into pellets with a diameter of 8-10mm by a pelletizer, and the pellet strength is tested to be ≥2.8kN / particle; finally, the pellets are dried to control the moisture content ≤5%, thus completing the iron ore pretreatment.

[0053] S4. Hydrogen-based vertical shaft furnace reduction: Pretreated iron ore is fed into a hydrogen-based vertical shaft furnace for direct reduction. The hydrogen-based vertical shaft furnace has a multi-layer counter-current structure, with a furnace height of 20-25m and an inner diameter of 5-6m. From top to bottom, it is arranged with an upper preheating zone, a middle reduction zone, and a lower combustion / supporting zone. Natural gas is heated to 800-900℃ and fed into the furnace as a reducing agent to react with the iron ore. The outlet temperature of the reduction zone is controlled at 650-750℃, and the residence time of the iron ore in the reduction zone is 60-120min to ensure that the sponge iron reduction degree is ≥90%.

[0054] S5. Tail gas recycling and steelmaking co-production: Using an electrically heated reformer to process the recovered tail gas into chemical products, synthesizing industrial organic compounds. Utilizing steel tail gas resources can eliminate the gasification stage, saving a significant amount of investment.

[0055] Among them, the utilization of medium-temperature waste heat: medium-temperature exhaust gas with a temperature of 200-400℃ is introduced into the Organic Rankine Cycle (ORC) device. The ORC device uses an environmentally friendly working fluid, which absorbs waste heat through phase change and drives a turbine to generate electricity.

[0056] Hydrogen-rich exhaust gas utilization: A gas turbine cogeneration unit is set up to send the exhaust gas, which is still rich in hydrogen after recovery, or the vent gas from the hydrogen storage system into the gas turbine for combustion and power generation; at the same time, the exhaust gas from the gas turbine is connected to the waste heat recovery system to further utilize the waste heat and realize the cascade utilization of waste heat.

[0057] Hydrogen recovery is performed on the exhaust gas after waste heat recovery: a combined process of membrane separation and pressure swing adsorption (PSA) is adopted. First, the hydrogen in the exhaust gas is initially separated by membrane separation, and then the PSA process is used for deep purification to ensure that the hydrogen recovery efficiency is ≥85%. The recovered hydrogen is compressed to -50 to 30 bar by a two-stage compressor and then returned to the hydrogen storage system in S2 for recycling to hydrogen-based vertical furnace as a reducing agent injection gas, realizing the closed-loop utilization of hydrogen. At the same time, the recovered reducing gas can still be used to synthesize syngas to produce methanol, olefins, diesel, ethylene glycol, etc. This not only provides a new idea and solution for the comprehensive utilization of steel plant exhaust gas, but also significantly reduces the cost of gasification stage, while providing a guarantee for national energy security.

[0058] S6. Full-process monitoring and control: A distributed control system (DCS) / supervisory and data acquisition system (SCADA) is used to dynamically monitor and optimize the scheduling of the entire process from S1 to S5. The DCS / SCADA system includes an energy management layer (EMS), a manufacturing execution layer (MES), and a process control layer (PCS). The functions of each layer are as follows:

[0059] Energy Management System (EMS): Real-time monitoring of energy data such as renewable electricity output, hydrogen production, and total system energy consumption; generating the next day's renewable electricity output curve and energy demand plan based on predictive models.

[0060] Manufacturing Execution System (MES): Tracks production indicators such as the reduction degree of sponge iron and coordinates the start-up, shutdown and load adjustment of each production unit;

[0061] Process Control System (PCS): Collects real-time parameters such as temperature, pressure, flow rate, and gas composition of each device to achieve precise control of equipment such as water electrolysis unit, hydrogen-based vertical furnace, and waste heat boiler;

[0062] The units are interconnected via industrial Ethernet and OPC-UA protocol, with data transmission latency ≤100ms, ensuring the real-time performance and reliability of control commands and monitoring data. Simultaneously, the system features fault diagnosis and alarm linkage functions: when hydrogen production in the water electrolysis unit is interrupted, the hydrogen storage system is automatically activated for replenishment; when the waste heat boiler requires maintenance, the ORC unit is automatically controlled to operate at reduced load; when a leak is detected in the hydrogen pipeline, the relevant valves are immediately closed and the forced ventilation system is activated, while simultaneously issuing an audible and visual alarm.

[0063] S7. Environmental protection and resource recycling: Reduce the circulating water consumption of industrial water treatment systems;

[0064] Water resource recycling: An industrial water treatment system is set up, which includes a bar screen, sedimentation tank, membrane filtration unit and disinfection unit; the process water, cooling water and exhaust gas condensate are sequentially subjected to solid-liquid separation (bar screen and sedimentation tank), oil removal (air flotation device), deep filtration (membrane filtration unit) and disinfection (ultraviolet disinfection). The treated water is returned to the system for recycling, thereby reducing the total circulating water consumption.

[0065] S8. Safety Assurance Design: All production equipment (electrolysis water unit, hydrogen-based vertical furnace, gas turbine, etc.), pipelines, valves, and electrical devices are designed with explosion-proof ratings according to relevant standards to meet the safety requirements of the hydrogen environment; the entire hydrogen pipeline is equipped with high-sensitivity hydrogen leak sensors (detection limit ≤1 vol%) and a forced ventilation system. When a leak is detected, the forced ventilation system automatically starts to accelerate hydrogen diffusion; at the same time, the system is equipped with an emergency shut-off valve, which can quickly cut off the hydrogen supply in an emergency to ensure the safe operation of the entire plant.

[0066] Example 1

[0067] A green electricity-driven hydrogen-based vertical shaft furnace co-production method for steelmaking includes the following steps:

[0068] S1. Renewable power supply and dynamic management: Construct a 100MW wind farm and a 50MW photovoltaic power station as renewable power sources. The wind farm will use 20 wind turbine generators with a single unit capacity of 5MW. The photovoltaic power station will use monocrystalline silicon photovoltaic modules with a total installed capacity of 50MW.

[0069] S2. Electrolysis of water to produce hydrogen and hydrogen purification and storage: Two 50MW proton exchange membrane electrolyzers (PEM) are selected. The water electrolysis device first removes N2 through a ceramic membrane separation device, and then purifies it through a PSA adsorption device (the adsorbent is a molecular sieve).

[0070] Hydrogen is compressed using a three-stage reciprocating compressor and then sent to a molecular sieve drying device. After drying, it is stored in a high-pressure carbon fiber composite bottle group and a medium-pressure storage tank. Both the bottle group and the storage tank are equipped with safety valves, flame arresters and semiconductor hydrogen leakage sensors.

[0071] S3. Iron Ore Pretreatment: Purchase sintered ore with an Fe content of 68 wt.%, first coarsely crush it to ≤50 mm using a jaw crusher, then finely crush it to ≤20 mm using a hammer crusher; the crushed ore is fed into a disc pelletizer to form 8 mm pellets, and the pellet strength is tested by a pressure testing machine to be 2.9 kN / pellet; the pellets are dried by a rotary dryer, and the moisture content is controlled at 4%;

[0072] S4. Hydrogen-based vertical shaft furnace reduction: The hydrogen-based vertical shaft furnace is 25m high and 6m in inner diameter. The upper preheating zone is 5m high, the middle reduction zone is 12m high, and the lower combustion zone is 8m high. Hydrogen and nitrogen are mixed at a ratio of 9:1 and heated to 850℃ by an electric heater before being fed into the furnace. The iron ore stays in the reduction zone for 60 minutes, and the outlet temperature of the reduction zone is 700℃. Slag is discharged from the lower slag outlet of the furnace every 2 hours, with each batch of slag being 1m high. 3 The Fe content in the slag is ≤1.5%; the unloading temperature of the sponge iron is 650℃, and it is slowly cooled to 350℃ in a slow cooling pit;

[0073] S5. Tail Gas Recirculation and Steelmaking Cogeneration: The tail gas temperature of the hydrogen-based vertical shaft furnace is 550℃. It is introduced into two 8MPa / 450℃ high-temperature waste heat boilers, producing 100kt of steam annually. The steam drives a 15MW steam turbine generator to generate electricity, with an annual power generation of 80GWh. The tail gas temperature is 400℃. Part of it is introduced into the ORC unit (working fluid is R245fa), generating 20GWh annually. The remaining tail gas and hydrogen-rich tail gas (H2 content 25%) after hydrogen recovery are sent to a 10MW gas turbine to generate electricity, generating 10GWh annually. The exhaust gas from the gas turbine (temperature 320℃) is connected to the waste heat boiler for further utilization.

[0074] S6. Full-process monitoring and control: In the DCS / SCADA system, the energy management layer (EMS) monitors wind and solar power output in real time (data refresh frequency 1s), the manufacturing execution layer (MES) tracks the reduction degree of sponge iron (tested once every 30 minutes), and the process control layer (PCS) controls the current fluctuation of the water electrolysis unit to ≤±2%. All units are interconnected via industrial Ethernet (Profinet), with a data transmission delay of 80ms. In fault simulation tests, after a power outage in the water electrolysis unit, the hydrogen storage system started replenishment within 3 seconds, without affecting the operation of the vertical furnace.

[0075] S7. Environmental Protection and Resource Recycling: Industrial water treatment system with a treatment capacity of 100m³ 3 / h, the screen removes large particulate impurities, the sedimentation tank removes suspended solids (removal rate 95%), the ultrafiltration membrane (pore size 0.1μm) removes colloids, and the water is reused after ultraviolet disinfection, reducing circulating water consumption by 35%;

[0076] S8. Safety Design: The hydrogen pipeline is made of 316L stainless steel and is equipped with an electrochemical hydrogen leak sensor, one every 10m; it is also equipped with an electrolysis water device, a hydrogen-based vertical furnace, and electrical equipment.

[0077] Example 2

[0078] A green electricity-driven hydrogen-based vertical shaft furnace co-production method for steelmaking includes the following steps:

[0079] S1. Renewable Power Supply and Dynamic Management: An 80MW wind farm and a 60MW photovoltaic power station will be constructed as renewable power sources. The wind farm will use 20 wind turbines with a single unit capacity of 4MW each; the photovoltaic power station will use bifacial monocrystalline silicon modules with an installed capacity of 60MW. A 20MWh lithium battery energy storage system will be constructed to facilitate peak shaving and valley filling, as well as smooth regulation of loads generated through hydrogen electrolysis.

[0080] S2. Hydrogen Production and Purification via Water Electrolysis: One 60MW proton exchange membrane (PEM) electrolyzer and one 40MW alkaline electrolyzer are operated in parallel. Hydrogen produced from water electrolysis is initially dehydrated by a cyclone separator, then passes through a ceramic membrane device to remove impurities, and is further purified by a PSA device to achieve a hydrogen purity ≥99.9%. The hydrogen is then subjected to two stages of centrifugal compression and one stage of piston compression before being sent to a molecular sieve drying device. After drying, it is stored in a 150 bar medium-pressure storage tank and a 30 bar buffer tank, respectively.

[0081] S3. Iron ore pretreatment: Sintered ore with an Fe content of 67.5 wt.% is used. It is first crushed to ≤40mm by a jaw crusher, and then crushed to ≤15mm by a roller crusher. The crushed ore is then processed into pellets with a particle size of 6-12mm by a disc pelletizer. The compressive strength of the pellets is ≥2.6kN / pellet. After drying by a belt dryer, the moisture content is controlled at 4.5%.

[0082] S4. Hydrogen-based vertical shaft furnace reduction: The vertical shaft furnace is 22m high and 5.5m in inner diameter. The volume ratio of hydrogen to nitrogen is 8.5:1.5. The ore is preheated to 830℃ before being fed into the furnace. The iron ore stays in the reduction zone for 55 minutes, and the outlet temperature of the reduction zone is 680℃. The resulting sponge iron has a metallization rate of ≥91%, and the unloading temperature is 620℃. After slow cooling, it is sent to subsequent processes.

[0083] S5. Tail gas recirculation and cogeneration of steelmaking: The tail gas temperature of the vertical furnace is about 520℃. It enters the waste heat boiler to generate 7MPa steam, which drives a 10MW steam turbine to generate electricity; the medium and low temperature tail gas enters the ORC unit to generate electricity, with an annual power generation of about 15GWh; the hydrogen-rich tail gas is partially returned to the vertical furnace after recovery, and the rest is sent to the gas turbine to generate electricity.

[0084] S6. Full-process monitoring and control: In the DCS / SCADA system, the energy management layer (EMS) monitors wind and solar power output in real time (data refresh frequency 1s), the manufacturing execution layer (MES) tracks the reduction degree of sponge iron (tested once every 30 minutes), and the process control layer (PCS) controls the current fluctuation of the water electrolysis unit to ≤±2%. All units are interconnected via industrial Ethernet (Profinet), with a data transmission delay of 80ms. In fault simulation tests, after a power outage in the water electrolysis unit, the hydrogen storage system started replenishment within 3 seconds, without affecting the operation of the vertical furnace.

[0085] S7. Environmental Protection and Resource Recycling: Industrial water treatment system with a treatment capacity of 100m³ 3 / h, the screen removes large particulate impurities, the sedimentation tank removes suspended solids (removal rate 95%), the ultrafiltration membrane (pore size 0.1μm) removes colloids, and the water is reused after ultraviolet disinfection, reducing circulating water consumption by 35%;

[0086] S8. Safety Design: The hydrogen pipeline is made of 316L stainless steel and is equipped with an electrochemical hydrogen leak sensor, one every 10m; it is also equipped with an electrolysis water device, a hydrogen-based vertical furnace, and electrical equipment.

[0087] Example 3

[0088] A green electricity-driven hydrogen-based vertical shaft furnace co-production method for steelmaking in medium-sized steel enterprises includes the following steps:

[0089] S1. Renewable power supply and dynamic management: Configure a 50MW photovoltaic power station and a 50MW centralized wind power as the main power sources, supplemented by a 15MWh energy storage system, to achieve a renewable power ratio of ≥85%.

[0090] S2. Hydrogen production and purification through water electrolysis: Two 30MW PEM electrolyzers are used. The hydrogen produced by electrolysis is purified by membrane separation and PSA, achieving a hydrogen purity of ≥99.95%. After being compressed by a three-stage piston, the hydrogen is stored in a high-pressure cylinder group (200bar) and a medium-pressure storage tank as a backup gas source for the continuous operation of the vertical shaft furnace.

[0091] S3. Iron ore pretreatment: Sintered ore with an Fe content of 69wt.% is used. After crushing, the average particle size is controlled at 3-10mm. After pelletizing, pellets with a particle size of 5-15mm are formed. The compressive strength of the pellets is ≥3.0kN / particle, and the moisture content is ≤4%.

[0092] S4. Hydrogen-based vertical shaft furnace reduction: The vertical shaft furnace is 20m high and 5m in diameter. The hydrogen inlet temperature is 840℃, the reduction residence time is 60min, the outlet sponge iron temperature is 660℃, and the metallization rate is ≥92%.

[0093] S5. Tail gas recirculation and co-production of tempering: The high-temperature tail gas generated by the vertical furnace and subsequent tempering process enters the waste heat boiler and ORC system in sequence to realize the co-production of steam, power generation and plant heating; the unreacted hydrogen in the tail gas is recovered and recycled, improving the overall energy efficiency by about 25%.

[0094] S6. Full-process monitoring and control: In the DCS / SCADA system, the energy management layer (EMS) monitors wind and solar power output in real time (data refresh frequency 1s), the manufacturing execution layer (MES) tracks the reduction degree of sponge iron (tested once every 30 minutes), and the process control layer (PCS) controls the current fluctuation of the water electrolysis unit to ≤±2%. All units are interconnected via industrial Ethernet (Profinet), with a data transmission delay of 80ms. In fault simulation tests, after a power outage in the water electrolysis unit, the hydrogen storage system started replenishment within 3 seconds, without affecting the operation of the vertical furnace.

[0095] S7. Environmental Protection and Resource Recycling: Industrial water treatment system with a treatment capacity of 100m³ 3 / h, the screen removes large particulate impurities, the sedimentation tank removes suspended solids (removal rate 95%), the ultrafiltration membrane (pore size 0.1μm) removes colloids, and the water is reused after ultraviolet disinfection, reducing circulating water consumption by 35%;

[0096] S8. Safety Design: The hydrogen pipeline is made of 316L stainless steel and is equipped with an electrochemical hydrogen leak sensor, one every 10m; it is also equipped with an electrolysis water device, a hydrogen-based vertical furnace, and electrical equipment.

[0097] The above-mentioned solution proposes a green electricity-driven hydrogen-based vertical shaft furnace co-production method for ironmaking, which can solve the technical problems existing in the prior art, such as the reliance on fossil power as the energy source for hydrogen-based vertical shaft furnace ironmaking, the low coupling degree between hydrogen production and reduction processes, the large fluctuations in furnace reduction temperature and atmosphere that easily lead to pellet agglomeration, and the low efficiency of tail gas and waste heat utilization.

[0098] This invention enables stable access and efficient consumption of green electricity through renewable power supply and dynamic management, reduces the dependence of hydrogen electrolysis and steelmaking on fossil power, smooths out fluctuations in renewable energy output, and improves the overall energy utilization efficiency and operational reliability of the system.

[0099] This invention enables the stable supply of high-purity hydrogen to hydrogen-based shaft furnaces and steelmaking units under different load conditions through hydrogen production by water electrolysis and hydrogen purification and storage. This achieves effective decoupling between hydrogen production, storage and use, providing a safe and reliable reducing gas source for continuous reduction and steelmaking processes.

[0100] This invention enables iron ore pretreatment to meet the requirements of hydrogen-based vertical shaft furnace direct reduction process in terms of particle size, strength, and moisture content, improves the permeability of the furnace bed, reduces the risk of pellet breakage and agglomeration during reduction, and enhances the uniformity and stability of the reduction reaction.

[0101] This invention enables efficient direct reduction of iron ore under low-carbon and low-impurity conditions through hydrogen-based vertical furnace reduction, resulting in sponge iron with high reduction degree and high metallization rate, while significantly reducing carbon dioxide emissions and improving the level of green ironmaking.

[0102] This invention enables the full recovery and cascade utilization of high-temperature exhaust gas and residual hydrogen generated during the vertical furnace and steelmaking process through tail gas recycling and co-production of steelmaking, realizing waste heat power generation, steam co-production and hydrogen recycling, further reducing system energy consumption and improving economic efficiency.

[0103] This invention enables the coordinated operation and dynamic optimization scheduling of hydrogen production, reduction, steelmaking and energy recovery units through full-process monitoring and control, ensuring stable process parameters, reducing human error, and improving the automation and intelligence level of the system.

[0104] This invention enables the efficient recycling and reuse of water resources, exhaust gas, and solid by-products through environmentally friendly resource recycling, reducing emissions of waste gas, wastewater, and solid waste, and meeting the requirements of green, low-carbon, and clean production.

[0105] This invention, through its safety-enhancing design, provides comprehensive leak-proof, explosion-proof, and emergency response capabilities throughout the entire process of hydrogen production, transportation, storage, and use, significantly improving the inherent safety level of the system and making it suitable for long-term stable industrial operation. This invention utilizes green electricity and hydrogen as the primary sources throughout the entire process, employing an electrically heated reformer to process recovered tail gas for chemical production, synthesizing industrial organic compounds. By utilizing steel mill tail gas resources, the gasification stage can be omitted, resulting in substantial investment savings and achieving both economic efficiency and reliability.

[0106] In summary, compared to traditional vertical shaft furnace hydrogen reduction of iron, the present invention creatively achieves a green electricity-driven hydrogen-based vertical shaft furnace co-production method for steelmaking through renewable power supply and dynamic management, water electrolysis for hydrogen production and hydrogen purification and storage, iron ore pretreatment, hydrogen-based vertical shaft furnace reduction, tail gas recycling and steelmaking co-production, full-process monitoring and control, environmental resource recycling, and safety assurance design. This method is simple and easy to operate, uses green electricity as an energy source, and is equipped with a device structure for stable hydrogen production and a full-process monitoring and control device structure. It is low in cost, high in safety, and high in production efficiency, which is conducive to large-scale industrial production and promotion.

[0107] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0108] In this invention, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be a single item or multiple items.

[0109] It should be understood that, in various embodiments of the present invention, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0110] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A green electricity-driven hydrogen-based vertical shaft furnace co-production method for steelmaking, characterized in that, The green electricity-driven hydrogen-based vertical shaft furnace co-production method for steelmaking includes the following steps: S1. Renewable power supply and dynamic management: Renewable power is generated from wind power and solar photovoltaic power, and is fed into the distributed energy management system DERMS via inverters and distribution transformers. DERMS dynamically schedules power according to grid electricity prices and energy demand. S2. Hydrogen production and purification storage via water electrolysis: Hydrogen is produced by using renewable electricity to drive a water electrolysis unit; the produced hydrogen is purified of impurities by membrane separation and PSA, dried, and stored in a hydrogen storage system with safety devices. S3. Iron ore pretreatment: Iron ore is pretreated by crushing, pelletizing, and drying to obtain pretreated pellets. S4. Hydrogen-based vertical shaft furnace reduction: The pretreated pellets are fed into a multi-layer countercurrent hydrogen-based vertical shaft furnace, and natural gas is introduced for reduction to obtain sponge iron. The tail gas is then recovered. S5. Tail gas recycling and co-production of steelmaking: using an electrically heated reformer to process the recovered tail gas into chemical products and synthesize industrial organic compounds. S6. Full-process monitoring and control: DCS / SCADA system is used for monitoring and scheduling; S7. Environmental protection and resource recycling: Reduce the circulating water consumption of industrial water treatment systems; S8. Safety Design: Equipment, pipelines, and valves are designed to be explosion-proof. Hydrogen pipelines are equipped with leak sensors and forced ventilation systems, and are equipped with emergency shut-off valves.

2. The green electric-driven hydrogen-based vertical shaft furnace steelmaking and co-production method according to claim 1, characterized in that, S1's distributed energy management system DERMS needs to be configured with a lithium battery energy storage system to smooth out power output fluctuations and ensure system load stability when green electricity output fluctuates.

3. The green electric-driven hydrogen-based vertical shaft furnace steelmaking and co-production method according to claim 1, characterized in that, S1's dynamic scheduling is as follows: full-load hydrogen production during off-peak electricity prices, and surplus electricity for peak shaving or sales during peak electricity prices.

4. The green electric-driven hydrogen-based vertical shaft furnace co-production method for steelmaking according to claim 1, characterized in that, The S2 water electrolysis unit uses molecular sieves, the deep drying unit uses a molecular sieve dryer, the hydrogen storage system includes a high-pressure gas cylinder group and a medium-pressure storage tank, and the safety devices include a safety relief valve, a flame arrester, and a leak sensor with a detection limit of ≤1 vol%.

5. The green electric-driven hydrogen-based vertical shaft furnace co-production method for steelmaking according to claim 1, characterized in that, The S2 water electrolysis device uses a proton exchange membrane electrolyzer (PEM) or a solid oxide electrolyzer (SOEC).

6. The green electric-driven hydrogen-based vertical shaft furnace steelmaking and co-production method according to claim 1, characterized in that, The S3 iron ore pretreatment uses a two-stage jaw and hammer crusher, and the pelletizer is a disc pelletizer. The drying temperature is 100-120℃. The hydrogen-based vertical shaft furnace is 20-25m high and 5-6m in inner diameter, with intermittent slag discharge from the lower slag outlet, with each batch being 0.8-1m high. 3 After the sponge iron is unloaded, it is slowly cooled to 300-400℃.

7. The green electric-driven hydrogen-based vertical shaft furnace co-production method for steelmaking according to claim 1, characterized in that, The sinter of S3 is sinter with Fe ≥ 67wt.% and the average size of the crushed sinter is 3-10mm. The pretreated pellets have a pellet size of 5-15mm, a strength ≥ 2.5kN / particle, and a moisture content ≤ 5%.

8. The green electric-driven hydrogen-based vertical shaft furnace co-production method for steelmaking according to claim 1, characterized in that, The inlet temperature of S4 is 800-900℃, the outlet temperature is 650-750℃, and the sponge iron reduction degree is ≥95%.

9. The green electric-driven hydrogen-based vertical shaft furnace co-production method for steelmaking according to claim 1, characterized in that, In S5, an electrically heated reformer is used to process the recovered tail gas for chemical production, synthesizing industrial organic compounds. By utilizing steel tail gas resources, the gasification stage can be omitted, resulting in significant investment savings.

10. The green electric-driven hydrogen-based vertical shaft furnace steelmaking and co-production method according to claim 1, characterized in that, The S6 DCS / SCADA system includes an energy management layer (EMS), a manufacturing execution layer (MES), and a process control layer (PCS). Each unit is interconnected via industrial Ethernet and OPC-UA, and features fault diagnosis and alarm linkage.

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