Operating method for electric arc furnace and steelmaking equipment

Abstract

The present invention discloses a method of operating an electric arc furnace, the method comprising recovering heated metallurgical gases, including water and carbon monoxide, from at least one unit (12) of a steel plant (100), conducting the metallurgical gases to a reactor (16) via a reactor feed line (14), treating the metallurgical gases in the reactor (16) to convert the carbon monoxide and water to hydrogen and carbon dioxide according to the water-gas shift reaction, and subsequently separating the hydrogen via a separator (18). The method further includes supplying an iron bearing material, including iron primarily in the form of iron oxide, to an electric arc furnace (10); at least partially melting the iron bearing material to obtain a molten bath; conducting hydrogen via a furnace feed line (20) to the electric arc furnace (10) disposed downstream of the furnace feed line (20); and injecting hydrogen into the electric arc furnace (10) via a plurality of hydrogen injectors (26) such that the hydrogen reacts as a reducing agent to reduce the iron oxide in the molten bath during a smelting operation of the electric arc furnace (10).

Description

Technical Field

[0001] The present invention relates to a method for operating an electric arc furnace, an electric arc furnace, and a steelmaking facility (steelworks, steel mill).

Background Art

[0002] Modern steelmaking facilities, each of the iron and steel and metal production facilities, are subject to the constraint of reducing carbon dioxide emissions. For this reason, steelmakers replace the fossil fuels used within the production facilities with so-called "green" electrical energy or "renewable" fuels. In this regard, hydrogen is used as a fuel and is thus considered an important factor in reducing CO2 emissions. However, the production, transportation, and storage of large amounts of hydrogen are significant technical challenges and are associated with high costs. For this reason, the prior art often focuses on the economic aspects of hydrogen production or the method of replacing fossil fuels with hydrogen in production.

[0003] The main integrated hydrogen production processes are steam reforming (of natural gas) and electrolysis. Steam reforming of natural gas is currently considered the most common and least expensive industrial hydrogen source. Natural gas (methane) is heated from 700 to 1100 °C in the presence of steam and a nickel catalyst. Methane molecules are decomposed, and carbon monoxide and hydrogen are formed. The carbon monoxide gas passes over iron oxide or other oxides together with steam, and additional hydrogen can be obtained by the so-called water gas shift reaction. The hydrogen produced in this way is economically attractive but still requires fossil fuels. In order to completely avoid CO2 emissions during hydrogen production, CO2 must be recovered and stored. In electrolysis, hydrogen is produced by a unit composed of several electrolytic cells, each cell having an anode and a cathode immersed in an electrolyte and connected to a power source.

[0004] However, both steam reforming and electrolysis are extremely expensive and require substantial amounts of energy as well as large-scale, secure infrastructure for the transport and storage of hydrogen. When one of these methods is set up to operate in an industrial environment, the corresponding manufacturing facilities are usually completely isolated from high-temperature areas, primarily for safety reasons. This has a significant drawback: valuable resources such as space and energy may simply be used inefficiently within and on such facilities.

[0005] Conventional technologies include electric furnaces such as electric arc furnaces (EAFs), which are typically used to produce steel from a charge mixture made of scrap and high-temperature metals, while EAFs primarily perform the melting process. If iron oxide is present in the charge mixture, EAFs can also reduce these iron oxides.

[0006] However, such reduction can only be performed in limited quantities due to process constraints. Such EAFs typically require an insertion mixture with a high degree of metallization. Therefore, when iron oxide is included in the EAF input feed, it generally results from directly reduced iron (DRI) with a degree of metallization of 88% or higher, produced by a previous gas-based direct reduction process. Such EAFs are called "directly heated" because they generate a high concentration of heat released from the electric arc formed between the electrode and the molten material.

[0007] Another type of electric furnace, the so-called submerged arc furnace (SAF), was developed for the reduction and melting of metal oxides. These SAFs can perform a complete reduction process starting from metal ores such as nickel, chromium, copper, or iron. In an SAF, the heating principle is based on the Joule effect, caused by the electric current generated by electrodes in a highly electrically resistive slag, with the electrodes immersed in the molten material, either in the slag or the molten bath. Generally, the process parameters in an SAF differ from those of the EAF described above. SAFs enable a complete reduction process from iron or other metal ores.

[0008] The reduction process in EAF and SAF is carried out with carbon, generally in the form of coke or anthracite, as the reducing agent, which can be injected through a suitable lance or filled from a top-filling system.

[0009] When pre-reduced iron pellets, directly reduced iron (DRI), or hot-formed reduced iron (HBI) are included in the raw materials to be melted, some of the carbon required for the reduction process is already present in the DRI or HBI pellets. Therefore, the reduction reaction in EAF is carried out by both the injected carbon and the carbon present in the directly reduced iron.

[0010] Carbon is not only necessary as a reducing agent in EAF and SAF, but also for maintaining appropriate process conditions in terms of reaction kinetics, overall energy balance, heat transfer coefficient, and process yield.

[0011] Therefore, such reactors have the disadvantage of emitting relatively large amounts of carbon dioxide during their operation. Object of the invention

[0012] Therefore, an object of the present invention is to provide a method for operating an electric arc furnace in a steelmaking facility that significantly reduces the amount of carbon dioxide emitted.

[0013] This objective is achieved by the subject matter of the independent claim. [Overview of the project]

[0014] The present invention proposes a method for operating an electric arc furnace, which includes recovering heated metallurgical gas containing water and carbon monoxide from at least one piece of equipment in a steelmaking facility. The metallurgical gas is introduced into a reactor by a reactor supply line. The method further includes converting the carbon monoxide and water contained in the metallurgical gas into hydrogen and carbon dioxide according to a water-gas shift reaction by processing the metallurgical gas in the reactor, and subsequently separating the hydrogen by a separation device. The method further includes providing an iron-containing material, mainly iron in the form of iron oxide, to an electric arc furnace; at least partially melting the iron-containing material to obtain a molten bath; conducting hydrogen to an electric arc furnace located downstream of the furnace supply line by a furnace supply line; and injecting hydrogen into the molten bath in the electric arc furnace by a plurality of hydrogen injection devices so that the hydrogen reacts as a reducing agent for reducing iron oxide in the molten bath during the refining operation of the electric arc furnace.

[0015] This method is based on the understanding that hydrogen can be produced and used in a more sustainable and environmentally friendly manner in steelmaking facilities, and that it can be advantageously used as a reducing agent in electric arc furnaces operating as electric refineries. It is known that hydrogen (H2) can be separated from different on-site facilities in steelmaking facilities, and from multiple metallurgical gases emitted from each facility. For example, hydrogen can be obtained / generated by vapor injected into CO-rich gases such as blast furnace gas by utilizing a water-gas shift reaction.

[0016] "Metallurgical gases" can generally refer to any gases emitted from metallurgical equipment, such as (blast) furnaces, stoves, coke cells, or similar facilities. Metallurgical gases form the basis of so-called synthesis gas, a mixture of fuel gases, mainly hydrogen, carbon monoxide, and very often some carbon dioxide.

[0017] In particular, this method aims to utilize the availability of synthesis gas containing hydrogen and / or carbon monoxide in steelmaking facilities, where carbon monoxide is used for steam separation of hydrogen. Synthesis gas can be obtained from metallurgical gases by, for example, carrying out a Boudouar reaction and / or a water-gas shift reaction according to known techniques. Alternatively, hydrogen may also be produced by other processes such as natural gas reforming, biomass reforming, or steam reforming. An example of a metallurgical gas may be blast furnace gas. Blast furnace gas contains or consists of about 20-30 vol% CO2, about 35-50 vol% N2, about 20-30 vol% CO, and about 5% H2. Another example of a metallurgical gas is so-called "converter gas." Converter gas contains or consists of about 60-70% CO, about 10-20% CO2, about 0-5% H2, and about 5-15% N2. Another example of a metallurgical gas is "coke oven gas." Coke oven gas contains, or consists of, approximately 5-10% CO, approximately 50-55% H2, approximately 20% CH4 and / or other hydrocarbons, less than approximately 10% N2, and small amounts of CO2. It should be noted that this composition and exemplary proportions can vary considerably depending on process conditions. The metallurgical gas can be mixed with steam for heating and / or water addition.

[0018] Metallurgical gases can be treated by methods commonly known to separate hydrogen from other compounds. For example, using water-gas shift (WGS) reactions and / or carbon dioxide removal methods, carbon monoxide (CO), which forms part of the metallurgical gas, can be converted to carbon dioxide. Carbon dioxide is then easily separated from the metallurgical gas (easier than carbon monoxide), and as a result, the remaining metallurgical gas contains a large amount of hydrogen, each at a specific high concentration.

[0019] Furthermore, it was found that recovering hydrogen gas by separating it from gases emitted by existing processes and equipment makes it possible to provide, maintain, and operate electric arc furnaces in a particularly economical and environmentally friendly manner.

[0020] This method is based on the knowledge that hydrogen can be introduced into an electric arc furnace (EAF), which is then injected into the molten bath and the slag, thereby operating the electric arc furnace as an electric smelter. During such operation of the EAF, hydrogen is used as a reducing agent instead of carbon when producing steel from iron-containing materials, primarily in the form of iron oxide. As a result, the amount of carbon dioxide emitted from such EAFs and metallurgical facilities can be significantly reduced. In this context, "primarily" means that more than 50%, preferably at least 60%, for example, at least 70%, at least 80%, or even more than 85% of the weight of the iron-containing material is in the form of iron oxide.

[0021] An "electric arc furnace" generally refers to an industrial furnace configured for a smelting process using an electric arc. The electric arc in an electric arc furnace (generated between electrodes or between electrodes and molten material, respectively, a metal bath or slag) can be configured to operate and maintain the process conditions necessary for a hydrogen-based reduction process. These process conditions can be characterized by parameters such as pressure, temperature, reaction kinetics, heat transfer coefficient, or similar parameters. An electric arc furnace may be powered by direct current or alternating current.

[0022] "Facilities" generally refers to any collection of industrial equipment or devices constructed, installed, or established to serve a specific purpose. For example, facilities may include, or consist of, blast furnaces, coke ovens, or hot blast furnaces.

[0023] "Steelmaking equipment" and "steelmaking plants" generally refer to industrial facilities where iron, steel, and / or metals are manufactured.

[0024] A "reaction device" generally refers to a device used as a container / tank / receptacle for a chemical reaction. The reaction device can also include, for example, multiple vats separated from each other by a (semi)permeable filter or a catalyst. For example, the reactor may be configured to convert carbon monoxide and water contained in the metallurgical gas into hydrogen and carbon dioxide.

[0025] A "furnace supply line" generally refers to a gas pipeline that introduces gas, particularly hydrogen, into a furnace such as an electric arc furnace.

[0026] A "reducing agent" generally refers to a substance that reduces a compound by donating electrons. According to the prior art electric arc furnace, iron oxide in the slag could be reduced by injecting coal. Furthermore, for example, carbon monoxide present in the melt, slag, or bath in the EAF can also act as a reducing agent for iron oxide. The reduction reaction in the EAF can be based on hydrogen as well as electrical energy. As a result, hydrogen can completely or at least partially replace carbon as a reducing agent, preferably up to at least 25 mol.%, advantageously up to at least 50%, preferably up to at least 60%, for example up to at least 70%, up to at least 80% or even up to almost 100 mol.%. In other words, the carbon currently used as a reducing agent in state-of-the-art electric arc furnaces can be partially or completely replaced by hydrogen. Carbon dioxide emissions can be completely prevented or at least significantly reduced.

[0027] "Conduction" usually refers to the act of guiding, transporting, and transmitting gas generally by providing a conductor or path in the form of, for example, a pipe, tube, line, (gas) pipeline, or similar technical element. A "reaction device supply line" generally refers to a gas pipeline that supplies gas to the reaction device.

[0028] "Recovery" generally refers to the process of separating, isolating, storing, absorbing, capturing, seizing, and / or preventing the discharge or release of a gas into the external environment, such as a gas. For example, metallurgical gas discharged from a blast furnace can be recovered by appropriate filters and / or separation devices.

[0029] "Injection" generally refers to the introduction of a gas into a facility such as an EAF, or to a melt or mixture of compounds within a facility such as slag. Injection can be performed using an injection device. An "injection device" generally refers to any device used or configured to inject a gas such as hydrogen or oxygen into a melt or mixture of compounds within a facility or within a compound within the facility. For example, the injection device may be immersed in a molten bath.

[0030] "Operation" generally refers to the act of functioning.

[0031] "Refining" generally refers to the process of melting and reducing a metal-containing material, such as an iron ore containing iron mainly in the form of iron oxide, which results in chemical changes or reactions within the molten state and leads to the separation of metals such as metallic iron.

[0032] "Separation" generally refers to the act of separating gas components from a gas mixture. For example, after a metallurgical gas is converted into hydrogen, carbon dioxide and possibly further by-products within a reactor, the hydrogen can be separated from the mixture using, for example, one filter or a plurality of membranes. Furthermore, separation can also be carried out by known methods such as gas separation methods based on cryogenic distillation, swing adsorption technology, the Hampson-Linde cycle or similar separation methods. A "separation device" generally refers to a device or a set of connected devices used or configured to operate a separation step or a separation method.

[0033] "Conversion" generally refers to a change in the composition, structure, form or appearance of one or more substances, such as a gas mixture.

[0034] "Processing" or "processing" generally refers to providing something to a drug, catalyst, energy, chemical, biological or physical influence, or the action of a process. For example, processing may include introducing metallurgical gases in a reactor to a heated catalyst.

[0035] In some embodiments, the metallurgical gas has a temperature in the range of 20°C to 100°C after the associated gas scrubbing. It has been found that the metallurgical gas can be preheated in a suitable heat recovery system, utilizing some of the available heat from other processes within the integrated steelmaking facility and converting it into subsequent reactions in a particularly energy-efficient manner. The metallurgical gas may be generally available at temperatures of 20°C to 100°C, preferably below 50°C. The metallurgical gas can be stored in a gas holder after gas scrubbing, for example, gas scrubbing in a scrubber. It should be noted that, depending on their configuration, these heated metallurgical gases may be subjected to known heat recovery methods.

[0036] The process of converting carbon monoxide and water into hydrogen and carbon dioxide involves at least a water-gas shift reaction, which takes place in the presence of a catalyst. The "water-gas shift reaction," also known as the water-gas shift reaction or water-gas conversion reaction, is a process for reducing the carbon monoxide content in synthesis gas and producing hydrogen. This reaction equation is also known as the conversion equilibrium: CO + H2O ⇔ CO2 + H2.

[0037] In some embodiments, the method further includes separating hydrogen and then guiding the hydrogen to a hydrogen storage tank via a storage supply conduit. "Storage supply conduit" generally refers to a pipeline used or configured to guide hydrogen to a hydrogen (storage) tank.

[0038] In some embodiments, the method further includes discharging hydrogen from a hydrogen storage tank to an electric arc furnace via a furnace supply line.

[0039] In some embodiments, the method further includes heating the hydrogen upstream of the electric arc furnace so that the hydrogen has a temperature in the range of 25 to 700°C when it is injected into the electric arc furnace. Heating the hydrogen increases the pressure, which in turn promotes the distribution of the injected hydrogen in the molten bath. It should be noted that “heating” can also refer to the process of preheating the hydrogen gas before it is injected into the EAF.

[0040] In some embodiments, the hydrogen injection apparatus comprises at least one supersonic gas lance for injecting at least a portion of the hydrogen supplied to the electric arc furnace into the furnace. In other words, the gas is injected at supersonic speeds.

[0041] In some embodiments, hydrogen injected via a supersonic gas lance is 10 m 3 / min~500m 3 It has a throughput in the range of / minute.

[0042] In some embodiments, the method further includes injecting oxygen into an electric arc furnace via a plurality of oxygen injection devices. The oxygen may be injected at least partially in the bath, and each in the slag, to oxidize the iron. In other words, the oxygen oxidizes at least a small amount of iron in the bath to wustite (FeO) by utilizing the heat released from the exothermic reaction, which may be locally required to maintain the desired process conditions.

[0043] In some embodiments, the method further includes introducing lime into the electric arc furnace by a lime introduction device. “Lime introduction device” generally refers to any device used or configured for the introduction, injection, of lime into the electric arc furnace or the slag layer within the electric arc furnace. The lime may include, for example, quicklime, or consist of quicklime. Lime can be used as a flux for cleaning the steel in the electric arc furnace (EAF). For example, lime can be used to remove sulfur, silica, phosphorus, and similar substances.

[0044] In some embodiments, the method further includes inserting / introducing a material into an electric arc furnace, the material comprising at least one of iron oxide, pre-reduced iron ore pellets, directly reduced iron (DRI), hot briquette iron briquettes (HBI), blast furnace grade, DR grade iron ore pellets or powder, or mixtures thereof. For example, a small amount of carbon that can be used to heat the molten material may be provided by directly reduced iron in the form of cold pellets or hot briquettes. These reduced irons can be produced by a natural gas-based direct reduction process.

[0045] In some embodiments, the method further includes supplying electrical energy to an electric arc furnace, which is used to operate the EAF, and the electrical energy is obtained from a renewable energy source. "Renewable energy source" generally refers to a source that supplies electrical energy based on at least one of solar energy, wind energy, hydroelectric energy, biomass energy, geothermal energy, tidal energy and wave energy, or a mixture thereof. The use of a renewable energy source enables the production of "green steel" that is largely or completely CO2-free, provided that only DRI / HBI from iron ore and / or a hydrogen-based direct reduction process is used to fill the EAF as iron bearing material.

[0046] The present invention further comprises an electric arc furnace, From at least one piece of steelmaking equipment, heated metallurgical gas containing water and carbon monoxide is recovered. The metallurgical gas is supplied to the reactor via the reactor supply line. The metallurgical gas in the reactor is treated to convert carbon monoxide and water into hydrogen and carbon dioxide according to the water-gas shift reaction, and subsequently, Hydrogen is separated using a separation device. It was done in this way, Iron-containing materials, mainly in the form of iron oxide, are supplied to an electric arc furnace. A molten bath is obtained by at least partially melting the iron-containing material. Hydrogen is supplied via the furnace supply line to the electric arc furnace located downstream of the furnace supply line. This invention relates to a steelmaking facility in which hydrogen is injected into the molten bath of an electric arc furnace by multiple hydrogen injection devices so that hydrogen acts as a reducing agent for reducing iron oxide in the molten bath during the refining operation of the electric arc furnace. The aforementioned improvements and embodiments of the method according to the present invention are also applicable to steelmaking equipment.

[0047] Further aspects and features of the present invention are derived from the dependent claims, the accompanying drawings and the following description of embodiments. [Brief explanation of the drawing]

[0048] Next, embodiments of the present invention will be described, by example, with reference to the accompanying drawings. [Figure 1] This is a schematic diagram showing the method, electric arc furnace, and steelmaking equipment according to the present invention. [Figure 2] This is a schematic diagram showing an electric arc furnace according to the present invention. [Modes for carrying out the invention]

[0049] Figure 1 shows a schematic diagram of the method according to the present invention, as well as an electric arc furnace 10 and steelmaking equipment 100. The steelmaking equipment 100 comprises equipment 12 consisting of a blast furnace 12 that discharges heated metallurgical gas containing water and carbon monoxide. The gas from the blast furnace has a temperature in the range of about 200°C to 300°C. The metallurgical gas can be washed by a scrubber and stored in a gas holder (not shown). As shown in Figure 1, the metallurgical gas discharged by the blast furnace 12 is captured and led to the reactor 16 by / through a reactor supply line 14. The metallurgical gas must be preheated for the hydrogen production process, for example by mixing the metallurgical gas with steam (not shown), the steam providing the heat and water required for the water-gas shift reaction.

[0050] Further devices (not shown), such as temperature sensors, pressure sensors, flow meters, and (automatic) valves, may be located on and / or within the reactor supply line 14. These further devices may be connected to a control device, such as a computer (not shown). The control device may be configured to determine process parameters related to the metallurgical gas, such as the temperature of the metallurgical gas, the pressure of the metallurgical gas, and / or the rate of the metallurgical gas. Depending on these process parameters, the control device can, by software, determine whether valves located within the reactor supply line 14 should be fully open, partially open, or closed.

[0051] The metallurgical gas, introduced through the reactor supply line 14, is brought into the reactor 16, where carbon monoxide and water compounds in the metallurgical gas are converted to carbon dioxide and hydrogen. The conversion of carbon monoxide and water to hydrogen and carbon dioxide is based on a water-gas shift reaction in the presence of a catalyst, such as a nickel-based catalyst (not shown). Further steps can be performed upstream of the reactor to heat the gas and / or to separate substances from the metallurgical gas that would harm the catalyst (not shown) before the metallurgical gas is processed in the reactor.

[0052] After the gas is processed in the reactor, it is led to a separator 18, where hydrogen is separated from other compounds of the metallurgical gas. In the next step, the hydrogen is led either directly to an electric arc furnace located downstream of the furnace supply line 20 by the furnace supply line 20, or to a hydrogen storage tank 24 via a supply conductor 22. (Automatic) valves are located in the supply conductor 22 and the furnace supply line 20 (not shown) to operate the passage of hydrogen toward the tank 24 and / or the electric arc furnace 10. The valves are equipped with actuators operated by a computer. Furthermore, both the furnace supply line 20 and the supply conduit 22 are equipped with pressure sensors, flow meters, and temperature sensors (not shown), respectively, connected to a computer. Depending on the requirements of the electric arc furnace 10, the hydrogen is conducted either directly into the furnace or into the storage tank 24. If the hydrogen is stored in the tank 24, the hydrogen may be released into the electric arc furnace at a predetermined rate and / or volume. As can be further deduced from Figure 1, a discharge line 23 for discharging hydrogen is in fluid communication with the furnace supply line 20. The discharge line 23 includes a temperature sensor, a flow meter, a pressure sensor, and an (automatic) valve, each of which is connected to and operated by a control device (not shown).

[0053] Furthermore, the furnace supply line 20 may include an optional heating device (not shown), which is also controlled by a computer. The heating device allows for heating of hydrogen upstream of the electric arc furnace, so that the hydrogen has a temperature in the range of 25°C to 700°C when injected into the electric arc furnace.

[0054] Hydrogen is injected into the electric arc furnace 10 via / by multiple injection devices 26, as shown in more detail in Figure 2. Two horizontal dashed lines within the furnace represent the boundary between the slag region 34 and the liquid metal region 36. During operation of the electric arc furnace, the slag layer 34 forms on the surface adjacent to the electrodes (not shown). Below the slag layer 34, the liquid metal layer 36 is generated after the electric arc furnace 10 has been operated for a certain period of time. The electrodes(s) of the EAF protrude from above into the slag, each from the furnace hat (not shown). In other words, the electrodes are at least partially immersed in the slag.

[0055] The multiple hydrogen injection devices 26 also include supersonic gas lances 28, which protrude from the top of the furnace, each from the furnace cover into the liquid metal area 36. During EAF operation, hydrogen is preferably injected at a rate of 10 m 3 / min~500m 3 It is injected via the supersonic gas lance 28 at a speed within the range of / min.

[0056] Furthermore, the electric arc furnace 10 is equipped with multiple oxygen injection devices 30 and lances for injecting oxygen into the electric arc furnace 10. The oxygen injection devices 30 are spaced apart from the hydrogen injection device 26 and the supersonic gas lance 28. Note that the oxygen injection device 26 may also be equipped with a supersonic gas lance, or may consist of a supersonic gas lance.

[0057] As further shown in Figure 2, the lime introduction device 32 protrudes into the liquid metal region 32 of the electric arc furnace, and also protrudes at the interface between the liquid metal region 32 and the slag region 34. The lime introduction device 32 provides lime injection during the operation of the electric arc furnace.

[0058] During operation of the electric arc furnace, the material is inserted into the furnace hearth. The material may include at least one of the following: scrap iron, iron oxide, pre-reduced iron ore pellets, directly reduced iron (DRI), hot briquette iron briquettes (HBI), blast furnace grade, DR grade iron ore pellets or powder, or mixtures thereof. The electric arc furnace is powered by electrical energy, which is obtained from renewable energy sources.

[0059] The injected hydrogen is used to reduce iron oxide (e.g., FeO) to iron (Fe) and water according to the following reaction equation. FeO + H2 → Fe + H2O

[0060] Furthermore, the injected hydrogen is used to react with oxygen, releasing heat according to the following equation. H2 + 1 / 2O2 → H2O

[0061] The injected oxygen is used to oxidize iron (Fe) according to the following equation: Fe + 1 / 2O2 → FeO.

[0062] As can be seen from Figure 2, the amount of carbon dioxide decreases overall or at least significantly during the operation of the electric arc furnace 10.

[0063] The embodiments described are examples of the present invention. Each described component in each embodiment represents an individual feature of the present invention that should be considered independently of each other. Therefore, these features should also be considered components of the present invention, individually or in combinations other than those shown. Furthermore, the described embodiments may be supplemented by further features of the present invention already described.

[0064] Further features and embodiments of the present invention will be provided to those skilled in the art in the context of this disclosure and claims. [Explanation of symbols]

[0065] 10 Electric arc furnace 12 Equipment 14. Reactor supply line 16 Reactor 18 Separation device 20 reactor supply lines 22 Storage and supply conductor 23 Discharge Line 24 tanks 26 Hydrogen injection device 28 Lance 30. Oxygen infusion device 32 Lime introduction device 34 Slag Area 36 metal layer 100 Steelmaking Equipment

Claims

1. A method for operating an electric arc furnace (10), A step of recovering heated metallurgical gas containing water and carbon monoxide from at least one piece of equipment (12) of the steelmaking equipment (100), The process involves conducting the metallurgical gas to the reactor (16) via the reactor supply line (14), The process involves converting carbon monoxide and water into hydrogen and carbon dioxide according to a water-gas shift reaction by processing the metallurgical gas in the reaction apparatus (16), Next, the process includes separating the hydrogen using a separation device (18), The aforementioned method, A step of supplying an iron-containing material, mainly iron in the form of iron oxide, to the electric arc furnace (10), A step of obtaining a molten bath by at least partially melting the iron-containing material, A step of guiding the hydrogen through the furnace supply line (20) to the electric arc furnace (10) located downstream of the furnace supply line (20), A method further comprising the step of injecting the hydrogen into the molten bath of the electric arc furnace (10) by a plurality of hydrogen injection devices (26) so that the hydrogen acts as a reducing agent for reducing iron oxide in the molten bath during the refining operation of the electric arc furnace (10).

2. The method according to claim 1, wherein the heated metallurgical gas has a temperature in the range of 20°C to 100°C.

3. The method according to claim 1 or 2, wherein the aqueous-gas shift reaction is carried out in the presence of a catalyst.

4. The method according to claim 1 or 2, further comprising the steps of: introducing the hydrogen to a hydrogen storage tank (24) via a storage supply conductor (22); and discharging the hydrogen from the hydrogen storage tank (24) to the electric arc furnace (10) via the furnace supply line (20).

5. The method according to claim 1 or 2, further comprising the step of heating the hydrogen upstream of the electric arc furnace such that the hydrogen has a temperature in the range of 25°C to 700°C when the hydrogen is injected into the electric arc furnace.

6. The method according to claim 1 or 2, wherein the plurality of hydrogen injection devices (26) each include at least one supersonic gas lance (28) for injecting at least a portion of the hydrogen supplied to the electric arc furnace (10) into the electric arc furnace (10).

7. The hydrogen injected through the supersonic gas lance (28) reaches 10 m ３ / min~500m ３ The method according to claim 6, having a throughput in the range of / min.

8. The method according to claim 1 or 2, further comprising the step of injecting oxygen into the electric arc furnace (20) via a plurality of oxygen injection devices (30).

9. The method according to claim 1 or 2, further comprising the step of introducing lime into the electric arc furnace (10) using a lime introduction device (32).

10. The method according to claim 1 or 2, further comprising the step of inserting a material into the electric arc furnace, wherein the material comprises at least one of iron oxide, pre-reduced iron ore pellets, directly reduced iron (DRI), hot briquette iron briquettes (HBI), blast furnace grade, DR grade iron ore pellets or powder, or a mixture thereof.

11. The method according to claim 1 or 2, further comprising the step of operating the electric arc furnace with electrical energy obtained from a renewable energy source.

12. A steelmaking facility (100) equipped with an electric arc furnace (10), From at least one piece of equipment (12) of the steelmaking equipment (100), heated metallurgical gas containing water and carbon monoxide is recovered. The metallurgical gas is transmitted to the reactor (16) via the reactor supply line (14). The metallurgical gas in the reaction apparatus (16) is processed to convert carbon monoxide and water into hydrogen and carbon dioxide according to the water-gas shift reaction, and subsequently, The hydrogen is separated by the separation device (18). It is configured in such a way, An iron-containing material, mainly containing iron in the form of iron oxide, is supplied to an electric arc furnace (10). A molten bath is obtained by at least partially melting the iron-containing material. The hydrogen is transmitted via the furnace supply line (20) to the electric arc furnace (10) located downstream of the furnace supply line (20). A steelmaking apparatus characterized in that the hydrogen is injected into the molten bath of the electric arc furnace (10) by a plurality of hydrogen injection devices (26) so that the hydrogen acts as a reducing agent for reducing iron oxide in the molten bath during the refining operation of the electric arc furnace (10).

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