Description:TECHNICAL FIELD
[0001] The present disclosure relates to the field of metallurgy. In particular, the present disclosure relates to a method for producing green rolled steel with significantly reduced greenhouse gas emissions using renewable energy sources. It may be appreciated that the term “green steel or green rolled steel" throughout the description refers to steel produced using environmentally friendly and sustainable methods which involves the usage of electricity generated from renewable energy sources, reduction of carbon dioxide emissions, and minimization and recycling of waste during the production process.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present disclosure. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed disclosure, or that any publication specifically or implicitly referenced is prior art.
[0003] Steel production plays an important role in modern industrial economies, serving as a primary material in construction, transportation, and manufacturing. The process of steelmaking involves the conversion of raw materials, such as iron ore, scrap metal, and various alloys, into steel through methods like the Blast Furnace-Basic Oxygen Furnace (BF-BOF) route, Electric Arc Furnace (EAF) route, and Induction Furnace (IF) route. These processes are energy-intensive and traditionally rely on fossil fuels and electricity contributing significantly to greenhouse gas (hereinafter “GHG”) emissions. The steel industry is continuously seeking methods to improve efficiency, reduce emissions, and enhance the quality of steel products.
[0004] India is currently the world's second-largest steel producer & aspires to achieve crude steel production capacity of 300 million Tons by 2030. Steel industry contributes ~7-9% of total global Greenhouse Gas (hereinafter “GHG”) emissions making it the fifth largest polluting industry in the world while in India it contributes ~12%. Hence, decarbonizing the steel industry and producing green steel is need of the hour.
[0005] In the steel industry, primary goal is to reduce the environmental impact of steel production, particularly by minimizing GHG emissions. This involves optimizing the use of raw materials, improving energy efficiency, and integrating renewable energy sources into the production process. Additionally, there is a focus on developing new technologies and methods that can produce high-quality steel with lower carbon footprints. The industry aims to achieve these goals while maintaining or improving the quality, mechanical properties and performance of steel products to meet the demands of various applications.
[0006] Traditional steelmaking process is characterized as one of the highest emission intensive processes. The traditional steelmaking processes include Steel making through Blast Furnace (BF) – Basic Oxygen Furnace (BOF) route, Electric Arc Furnace route (EAF), and Induction Furnace (IF) route. In BF-BOF route, steel is produced with iron ore, in EAF route either 100% scrap or scrap along with Direct Reduced Iron (DRI)/ pig iron mix is used. Based on such different input raw material used for melting, the total GHG emission varies.
[0007] Achieving the goal of reducing greenhouse gas emissions in steel production is challenged by several obstacles. Traditional steelmaking processes are fundamentally carbon-intensive, and the transition to greener methods requires significant technological advancements and investments. The reliance on non-renewable energy sources and the transportation of raw materials further exacerbates the carbon footprint. Moreover, existing methods often do not adequately capture process emissions, leading to their release into the atmosphere. These challenges call for innovative approaches to steel production that can effectively address these environmental concerns.
[0008] Patent document, “CN 115,896,590 A” titled “Production process of a medium-high-quality thin-gauge carbon tool steel” discloses a production process of medium-high-quality thin-gauge carbon tool steel, which belongs to the technical field of production equipment for hot-rolled strip products in the metallurgical industry. It adopts a low-emission short-flow headless strip production process, including the use of a quantum electric furnace, smelting molten steel process, Ladle Furnace (LF) refining for molten steel refining process , Vacuum Oxygen Decarburization (VOD) or Ruhrstahl Heraeus (RH) refining for molten steel refining process outside the furnace, Endless Strip Production (ESP) continuous casting and rolling endless strip rolling process, the above production processes are effectively combined to form new endless strip steel. The production process produces high-quality thin-gauge carbon tool steel and produces high-carbon steel below the set specification of steel. The invention can effectively reduce energy consumption and harmful emissions in the production process of strip steel products. However, the method does not disclose process of producing green rolled steel using renewable energy sources.
[0009] Another patent document. “IN 20,2421,079,071” titled “A system and a method for producing green steel with near zero GHG emissions intensity”, discloses a method and a system for producing green steel. The method includes the initial step of obtaining scrap from one or more sources of scrap. The obtained scrap and ferroalloys are charged into an induction furnace and melted in an inert environment to obtain molten steel. The inert gases are introduced into the induction furnace to prevent oxidation of the scrap and different types of scrap alloys and ferroalloys during melting. The molten steel is transferred from the induction furnace either directly to a casting area or to a refining unit to refine the molten steel. The refined steel was transferred to a vacuum-degassing unit to degas the refined steel. Finally, the vacuum-degassed steel is transferred to a casting area to produce the green steel. However, the method does not disclose process of producing green rolled steel using renewable energy sources.
[0010] Existing methods, as described above, do not adequately address the integration of renewable energy sources. Hence, in view of the aforementioned challenges and shortcomings in prior arts, there is a dire need in the art to provide a system and a method for producing green rolled steel with very low GHG emission intensity.

OBJECTS OF THE PRESENT DISCLOSURE
[0011] Some of the objects of the present disclosure, which at least one embodiment herein satisfies are as listed herein below.
[0012] It is a general object of the present disclosure to overcome the limitations of existing methods of steel production while reducing GHG emission intensity.
[0013] It is an object of the present disclosure to provide a method for producing green rolled steel with very low GHG emissions.
[0014] It is another object of the present disclosure to minimize direct GHG emissions during the steel rolling process by utilizing biodiesel in reheating furnaces.
[0015] Yet another object of the present disclosure is to provide a system and a method that reduces indirect emissions from electricity generation by utilizing renewable energy sources, such as solar and wind power, to power steel production facilities, including induction furnaces, electric arc furnaces, and rolling mills etc.
[0016] Yet another object of the present disclosure is to provide a system and a method that integrates technologies to reduce GHG emissions throughout the entire steel production process, from raw material purchase to final product manufacturing, ensuring that the overall carbon footprint is minimized.
[0017] Yet another object of the present disclosure is to enable the production of all types of steel including low carbon, medium carbon, high carbon, high-strength low-alloy (HSLA), low alloy steel, high alloy steel, stainless steel, Fe-based super alloy & tool and die steel, valve steel using environmentally friendly methods that align with sustainability goals.

SUMMARY
[0018] Within the scope of this application, it is expressly envisaged that the various aspects, embodiments, examples, and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments unless such features are incompatible.
[0019] Aspects of the present disclosure relate to the field of metallurgy. The present disclosure discloses a method of producing green rolled steel. The method includes obtaining crude steel from a casting unit by a casting process. A heating unit is selected based on the casting process applied to the size of the obtained crude steel. The obtained crude steel is heated by the selected heating unit. The heated crude steel is transferred to a blooming mill for initial deformation through hot rolling process. The blooming mill deforms the heated crude steel to a pre-determined size. After that the pre-deformed steel from blooming mill is hot rolled by a finish rolling unit until the pre-determined final size is achieved. The rolled steel is cut by a cutting unit to obtain a set of rolled bars to a pre-determined length. The set of rolled bars are cooled by a selected cooling unit to obtain the green rolled steel.
[0020] In another aspect of the present disclosure, the heating unit, blooming mill, the finish rolling unit, the cutting unit, and the cooling unit are operated using a power supply generated from a renewable energy source. The renewable energy source may include, but is not limited to, solar power, wind energy, or hydropower.
[0021] The crude steel is transferred to the heating unit from the casting unit by an electric vehicle. The temperature of the heating unit ranges between 700°C to 1350°C.
[0022] In yet another aspect, a system to produce green rolled steel is disclosed. The system includes the casting unit to obtain crude steel from different types of casting processes. The heating unit is configured to heat the obtained crude steel. The heating unit is selected based on the type of casting process applied to the obtained crude steel. A transferring means is configured to transfer the heated crude steel to the blooming mill for initial deformation. The blooming mill deforms the heated crude steel to a pre-determined initial size. The finish rolling unit is configured to hot roll the steel until the pre-determined final size is achieved. The cutting unit is configured to cut the rolled crude steel to obtain a set of rolled bars to a pre-determined length. Further, cooling unit is configured to cool the set of rolled bars to obtain the green rolled steel.
[0023] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF DRAWINGS
[0024] The accompanying drawings, which are incorporated herein, and constitute a part of this disclosure, illustrate exemplary embodiments of the disclosed methods and systems which like reference numerals refer to the same parts throughout the different drawings. Components in the drawings are not necessarily to scale; emphasis is instead placed upon clearly illustrating the principles of the present disclosure. Some drawings may indicate the components using block diagrams and may not represent the internal circuitry of each component. It will be appreciated by those skilled in the art that the disclosure of such drawings includes the disclosure of electrical components, electronic components or circuitry commonly used to implement such components.
[0025] FIG. 1 illustrates an exemplary representation of a flow diagram that illustrates a method of producing green rolled steel with very low GHG emission intensity for rolled products, in accordance with an embodiment of the present disclosure.
[0026] FIG. 2 illustrates an exemplary representation of a block diagram of a system to produce green rolled steel with very low GHG emission intensity for rolled products, in accordance with an exemplary embodiment of the present disclosure.
[0027] FIG. 3 illustrates an exemplary representation of a flow chart that illustrates development of a process with very low GHG emission intensity for producing green rolled steel products, in accordance with an embodiment of the present disclosure.
[0028] Other objects, advantages, and novel features of the disclosure will become apparent from the following more detailed description of the present embodiment when taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION
[0029] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of details offered are not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0030] Reference numerals used:
Method - 100
System -200
Casting unit - 204
Heating unit - 206
Blooming mill -208
Finish rolling unit - 210
Cutting unit - 212
Cooling unit - 214
Transferring means - 216
[0031] The present disclosure relates a method for producing green steel with significantly reduced greenhouse gas emissions using renewable energy sources. The main objective of the present disclosure is to produce steel with very low GHG emissions, as per scope 1, scope 2, and scope 3 defined by GHG protocol. The objective includes the reduction of emissions of GHG as per the below-mentioned scopes:
Scope 1: Direct Emissions during the manufacturing phase
Scope 2: Indirect Emissions during power generation
Scope 3: Indirect Emissions during the production of raw materials, fuels, and transportation.
[0032] Below table 1 gives the definition of emissions under above-mentioned scope 1, scope 2 and scope 3 defined by GHG protocol.

Table 1:
Scope no. Definition
Scope 1 Direct GHG emissions occur from sources that are owned or controlled by the company. (At source/manufacturing plant)
Scope 2 GHG emissions are indirect emissions from the generation of purchased energy, from a utility provider. In other words, all GHG emissions released in the atmosphere, from the consumption of purchased electricity, steam, heat, and cooling.
Scope 3 Emissions that are all indirect emissions consequence of the activities of the company but occur from sources not owned or controlled by the company.

[0033] The GHG emissions that occurred during steel making and casting are accounted in the rolled steel product GHG emissions calculations, as a part of scope 1 or scope 3 emissions depending on the facilities available in the organization. The cast steel (crude steel) which is input to the rolling mill can be produced through various manufacturing routes. Route 1: is induction furnace-based steel making. Route 2: is through an electric arc furnace followed by a ladle refining furnace and cast through ingot or continuous casting method. Route 3: is blast furnace followed by energy optimizing furnace then followed by ladle refining furnace and cast through ingot or continuous casting method. Route 1 is further divided into two sub-routes, induction furnace followed by ingot or continuous casting method. Another sub-route is the induction furnace followed by a ladle refining furnace and cast through ingot or continuous casting method. Route 1 has the lowest GHG emissions whereas Route 3 has the highest GHG emissions. During hot rolling operations, GHG emissions are also occurring while reheating process and during deformation. The present invention reduces GHG emissions occurring during the hot rolling process and post rolling cooling treatment operations. The GHG emissions occurred during cast steel production are added to the GHG emissions generated during hot rolling operation. Hence, the cast steel product needs to be selected from above mentioned manufacturing routes carefully.
[0034] Therefore, to address all the emission sources, the present invention discloses method to reduce the GHG emissions including scope 1 - direct emissions, scope 2 – indirect emissions due to power generation, and scope 3 – indirect emissions due to procurement of raw materials, transportation etc.
[0035] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings FIGs. 1-3.
[0036] FIG. 1 illustrates an exemplary representation of a flow diagram that illustrates a method (100) of producing green rolled steel with very low GHG emission intensity for rolled products, in accordance with an embodiment of the present disclosure.
[0037] Referring to FIG. 1, in an embodiment, the method (100) for producing green rolled steel. The method (100) includes an initial step (102) of obtaining crude steel from a casting unit (204) by a casting process. The casting unit (204) include different casting processes such as ingot and continuous casting to produce crude steel. The casting unit (204) is equipped with a set of molds to make different sizes of crude steel. The casting unit (204) further includes a cooling system that facilitates the solidification of the liquid steel.
[0038] At block 104, a heating unit (206) is selected based on the casting process applied to the obtained crude steel. The heating unit (206) includes a soaking pit for ingots produced from ingot casting process or a walking beam furnace (WBF) for blooms produced from continuous casting process. The heating unit (206) is used for heating the crude steel to achieve a suitable condition for further processing. The heating unit (206) is powered by a renewable energy source selected from any or a combination of solar power, biodiesel, wind energy, green hydrogen or hydropower. In such embodiment, the soaking pit and the WBF uses biodiesel for the heating.
[0039] At block 106, the obtained crude steel is heated by the selected heating unit (206), to the required temperature within the range of 700-1350°C. The heating unit (206) applies controlled heating to ensure uniform temperature distribution within the crude steel.
[0040] At block 108, after reaching the required temperature, the crude steel is transferred (110) to a blooming mill (208) for initial deformation. The transferring means (216) includes, but are not limited to, an automated conveyor system, Electric Vehicles (EVs), Automated Guided Vehicles (AGVs), overhead cranes, rail-bound transport systems, robotic arms, a roller table, or hydraulic or pneumatic lifts. The transferring means (216) can be selected based on factors such as layout, automation level, energy efficiency, and production capacity of the manufacturing plant for green rolled steel. The blooming mill (208) deforms the heated crude steel to a pre-determined size ranging from 100 mm to 800 mm in round corner square shape. The blooming mill (208) operates under controlled rolling conditions to refine the microstructure of the crude steel.
[0041] At block 110, a finish rolling unit (210) is used to further roll the deformed steel from blooming mill until the pre-determined final size is achieved. The finish rolling unit (210) includes multiple rolling stands to progressively reduce the thickness and enhance the mechanical properties of the steel. The finish rolling unit (210) is powered by electricity generated from a renewable energy source, ensuring an environmentally sustainable manufacturing process. The finish rolling unit (210) deforms the heated steel to a pre-determined final size ranging from 5 mm to 200 mm in round corner square or round shape.
[0042] In such embodiment, the predetermined final size can be achieved after blooming mill operations, and the deformed steel can be sent to cutting unit (212) for cutting the deformed steel to the predetermined final size. If the predetermined final size is not achieved after initial blooming operation, the deformed steel can be sent to the heating unit (WBF) (206) and then processed through either blooming mill (208) or finish rolling unit (210) to achieve the predetermined final size.
[0043] At block 112, the method (100) further includes a cutting unit (212) that cuts the rolled steel to obtain a set of rolled bars to a pre-determined length. The cutting unit (212) includes a hot saw machine or a shear cutting device to ensure precise cutting of the rolled crude steel. The cutting unit (212) is operated through a power supply derived from a renewable energy source.
[0044] At block 114, the set of rolled bars is cooled by a cooling unit (214), to obtain the green rolled steel. The cooling unit (214) includes an air-cooling system, a water-cooling system, furnace cooling, stress reliving, annealing or a combination of any of them to achieve the required cooling rate. The cooling unit (214) ensures uniform cooling of the rolled bars to attain the desired quality and metallurgical properties.
[0045] In an exemplary implementation of the embodiment, the crude steel is transferred to the heating unit (206) from the casting unit (204) by an electric vehicle. In such embodiment, the heating unit (206) can be operated within a temperature range of 700°C to 1350°C.
[0046] In the exemplary implementation of the embodiment, the method (100) can include crude steel which is obtained from the casting unit (204) by a casting process. The heating unit (206), the blooming mill (208), the finish rolling unit (210), the cutting unit (212), and the cooling unit (214) is operated using a power supply generated from a renewable energy source. Renewable energy sources can include, but are not limited to, solar power, biodiesel, wind energy, green hydrogen and hydropower. In such embodiment, the crude steel can be transferred to the heating unit (206) from the casting unit (204) by an electric vehicle or by an overhead crane.
[0047] In the exemplary implementation of the embodiment, the casting process can be selected from any or a combination of induction furnace (IF-CC/IC), induction furnace - ladle furnace - vacuum degassing (IF-LF-VD-CC/IC), electric arc furnace - ladle furnace - vacuum degassing/vacuum oxygen decarburization (EAF-LF-VD/VOD-CC/IC).
[0048] In the exemplary implementation of the embodiment, the heating unit (206) can be selected based on the casting process applied to the obtained crude steel. The heating unit (206) can be selected from any or a combination of soaking pit, walking beam furnace (WBF), rotary hearth furnace (RHF), and regenerative heating furnace. The heating unit (206) is configured to heat the crude steel before deformation in the blooming mill (208). The blooming mill (208) is used to deform the heated crude steel to a pre-determined initial size. The finish rolling unit (210) is used to hot roll the deformed steel from blooming mill until the final pre-determined size is achieved. The finish rolling unit (210) can be selected from any or a combination of blooming mill, rolling mill, continuous rolling mill, planetary rolling mill, cross rolling mill, ring rolling mill, skew rolling mill, and two-high or four-high rolling mill. The finish rolling unit (210) is configured to shape the crude steel into rolled steel.
[0049] In the exemplary implementation of the embodiment, the cutting unit (212) is configured to cut the rolled crude steel to obtain a set of rolled bars with a pre-determined length. The cutting unit (212) can include but is not limited to, hot saw machine, shearing machine, plasma cutting, laser cutting, oxy-fuel cutting, and water jet cutting. The cutting unit (212) is configured to precisely cut the rolled steel based on the desired dimensions of the rolled bars.
[0050] In the exemplary implementation of the embodiment, the cooling unit (214) is used to cool the set of rolled bars to obtain the green rolled steel. The cooling unit (214) can include, but is not limited to, air cooling, box cooling, furnace cooling or annealing, water quenching, stress relieving, spray cooling, controlled cooling beds, mist cooling, oil quenching, polymer quenching, salt bath cooling, hydrogen cooling, vacuum cooling, and cryogenic cooling. The cooling unit (214) regulates the temperature of the rolled bars and ensure quality and mechanical properties of the green rolled steel.
[0051] In the exemplary implementation of the embodiment, the process of producing green rolled steel involves multiple steps of heating, rolling, cutting, and cooling, ensuring the formation of the final product with the desired specifications. The use of renewable energy sources for operating the heating unit (206), blooming mill (208), finish rolling unit (210), cutting unit (212), and cooling unit (214) facilitates an environmentally sustainable manufacturing process.
[0052] FIG. 2 illustrates an exemplary representation of a block diagram (200) of a system (202) to produce green rolled steel with very low GHG emission intensity for rolled products, in accordance with an exemplary embodiment of the present disclosure.
[0053] In another embodiment, the system (202) to produce green rolled steel can include the casting unit (204) to obtain crude steel from different types of casting processes such as ingot or continuous casting is disclosed. The system (202) includes the heating unit (206) to heat the obtained crude steel, wherein the heating unit (206) is selected based on the type of casting process applied to the liquid steel. Ingots produced from ingot casting process are heated in soaking pit and blooms produced from continuous casting process are heated in the Walking Beam Furnace (WBF). The system (202) further includes the transferring means (216) to transfer the heated crude steel to the blooming mill (208) for initial deformation. The blooming mill (208) deforms the heated crude steel to a pre-determined initial size. The system (202) further includes the finish rolling unit (210) to finish-roll the steel until the final pre-determined final size is achieved. The cutting unit (212) cut the rolled steel to obtain a set of rolled bars to a pre-determined length. The cooling unit (214) cools the set of rolled bars, thereby obtaining the green rolled steel.
[0054] In an exemplary implementation of the embodiment, the system (202) includes the casting unit (204) to obtain crude steel from different types of casting processes. The casting unit (204) is configured to receive liquid steel from any of the process, including but are not limited to, induction furnace (IF-CC/IC), induction furnace - ladle furnace - vacuum degassing (IF-LF-VD-CC/IC), electric arc furnace - ladle furnace - vacuum degassing/vacuum oxygen decarburization (EAF-LF-VD/VOD-CC/IC), The selection of the casting process depends on the required sizes of the crude steel.
[0055] In the exemplary implementation of the embodiment, the system (202) includes the heating unit (206) to heat obtained crude steel. Heating unit (206) can be selected based on the type of casting process applied to the obtained crude steel. The heating unit (206) can include, but is not limited to, soaking pit and walking beam furnace (WBF), rotary hearth furnace (RHF), and regenerative heating furnace. The heating unit (206) can be operated at a temperature ranging between 700°C to 1350°C to achieve the required heating for further processing.
[0056] In the exemplary implementation of the embodiment, the system (202) includes a transferring means (216) to transfer the heated crude steel to the blooming mill (208) for deformation. The blooming mill (208) deforms the heated crude steel to a pre-determined size. The pre-determined size can range from 100 mm to 800 mm based on the required specifications of the rolled steel in round corner square shape. The crude steel can be transferred from the casting unit (204) to the heating unit (206) by an electric vehicle to ensure an eco-friendly transportation process.
[0057] In the exemplary implementation of the embodiment, the system (202) includes finish rolling unit (210) to hot roll the deformed steel from blooming mill until the pre-determined final size is achieved. The finish rolling unit (210) can include, but not limited, blooming mill, rolling mill, continuous rolling mill, planetary rolling mill, cross rolling mill, ring rolling mill, skew rolling mill, and two-high or four-high rolling mill. The rolling process can be carried out to achieve the desired dimensions and mechanical properties of the rolled steel. The finish rolling unit (210) deforms the heated pre-deformed steel to a pre-determined final size ranging from 5 mm to 200 mm in round corner square or round shape.
[0058] In the exemplary implementation of the embodiment, the system (202) includes cutting unit (212) to cut the rolled crude steel to obtain a set of rolled bars to a pre-determined length. The cutting unit (212) can include but not limited to, hot saw machine, shearing machine, plasma cutting, laser cutting, oxy-fuel cutting, and water jet cutting. The cutting process ensures precise dimensions of the rolled bars as per industrial requirements.
[0059] In the exemplary implementation of the embodiment, the system (202) includes cooling unit to cool the set of rolled bars, thereby obtaining the green rolled steel. The cooling unit (214) can include but not limited to air cooling, box cooling, furnace cooling or annealing, water quenching, stress relieving, spray cooling, controlled cooling beds, mist cooling, oil quenching, polymer quenching, salt bath cooling, hydrogen cooling, vacuum cooling, and cryogenic cooling. The cooling process can be controlled to enhance the mechanical properties of the rolled steel by achieving the desired microstructure.
[0060] In the exemplary implementation of the embodiment, the heating unit (206), the blooming mill (208), the finish rolling unit (210), the cutting unit (212), and the cooling unit (214) is operated using a power supply generated from a renewable energy source. Renewable energy sources can include but are not limited to, solar power, biodiesel, green hydrogen, wind energy, and hydropower. The use of renewable energy sources can reduce the carbon footprint of the steel manufacturing process, making it more environmentally friendly.
[0061] FIG. 3 illustrates an exemplary representation of a flow chart that illustrates the development of a process (300) with very low GHG emission intensity for producing rolled steel products, in accordance with an embodiment of the present disclosure.
[0062] Referring to FIG. 3, in an embodiment, the process (300) includes casting unit (204) which is configured to receive liquid steel from any of the process. These processes can include an induction furnace IF-CC/IC (302), an induction furnace-ladle furnace-vacuum degassing IF-LF-VD-CC/IC (304), and an electric arc furnace-ladle furnace-vacuum degassing/vacuum oxygen decarburization EAF-LF-VD/VOD-CC/IC (306). The crude steel can be obtained from the casting processes can have very low greenhouse gas emissions, as indicated by block 308.
[0063] The process (300) further includes heating unit (206) configured to heat the crude steel. The heating unit (206) can be selected based on the type of casting process applied to the crude steel. The heating unit (206) can include a walking beam furnace (310) for blooms produced from continuous casting (CC) process or a soaking pit (312) for ingots produced from ingot casting (IC) process. The heated crude steel can be transferred to blooming mill (314) for initial deformation. The blooming mill (314) can be configured to deform the crude steel to a predetermined initial size. The pre-deformed steel can then be further processed in a finish rolling mill (316) for final deformation. The finish rolling mill (316) can be configured to further deform the steel to a predetermined final size.
[0064] In such embodiment, determination can be made at block 318 regarding whether the required size has been achieved or not. If the required size has not been achieved, as indicated by decision block 320, the crude steel can be further heated in walking beam furnace (310) and processed through either blooming mill (314) or finish rolling mill (316). If the required size has been achieved, and the answer is "yes" (322) the deformed steel can proceed to hot saw cutting (324), where the rolled steel can be cut to obtain a set of rolled bars of a predetermined length.
[0065] In such embodiment, the process (300) includes cooling unit (214) configured to cool the set of rolled bars. The cooling unit (214) can be selected based on process requirements and can include air cooling (326), box cooling (328), or furnace cooling/annealing (330). After the cooling process, rolled bars with very low greenhouse gas emissions can be obtained, as shown in block 332.
[0066] In such embodiment, the heating unit (206), the blooming mill (208), the finish rolling unit (210), the cutting unit (212), and the cooling unit (214) can be operated using a power supply generated from renewable energy sources. Renewable energy sources may include but are not limited to, solar power, biodiesel, green hydrogen, wind energy, or hydropower. The crude steel can be transferred to the heating unit (206) from the casting unit (204) by an electric vehicle. The heating unit (206) may include but is not limited to soaking pit (312) and walking beam furnace (WBF) (310), rotary hearth furnace (RHF), or a regenerative heating furnace.
[0067] In such embodiment, the process (300) may facilitate the production of green rolled steel by incorporating energy-efficient processes and utilizing renewable energy sources. The selection of the casting process, heating unit (206), the blooming mill (208), finish rolling unit (210), cutting unit (212), and cooling unit (214) can contribute to the reduction of greenhouse gas emissions during the production of rolled bars. The implementation of controlled heating and cooling techniques can ensure that the rolled steel achieves the desired mechanical properties and dimensional accuracy.
[0068] In such embodiment, the ingot products from routes depicted in the flowchart (300) are reheated in pit type of soaking furnace before rolling. The temperature of soaking the ingots may range from 700°C to 1350°C. Similarly, the continuous cast blooms are heated in walking beam furnace at a temperature may range from 700 °C to 1350 °C prior to hot rolling. During hot rolling, the crude steel products are subjected to deformation due to hot rolling passes. The steel can be reheated more than once as per the requirement of the final sizes. Various cross-sectional sizes are made using two different rolling mills to make the final sizes in round corner square (RCS) or round cross-section. RCS shape is manufactured from the blooming mill (208) and round sections as well as RCS sections are produced from a Finish rolling mill. The blooming mill (208) can produce the rolled bars may be in the size range of 100 – 800mm RCS. The finish rolling mill can produce the rolled bars in the size range of either 5-200 mm round or 5-200 mm RCS. To achieve the required size, blooms can be reheated more than once. In single rolling required size is achieved in single reheating, whereas in double rolling blooms are reheated twice to achieve the required size. It may be appreciated by the person skilled in the art, the sizes mentioned herewith are not limited to mentioned ranges for the rolled products having bigger size, since the rolled products having bigger size can be manufactured using the proposed system (202) and the method (100).
[0069] Further, the rolled bars are cut as per the length requirement using hot saw cutting machine. Post cutting the blooms are sent to either, an annealing furnace (electrical) slow cooling box, or normal air-cooling area depending on the requirement specific to the material grade produced. After the stage, the rolled bars are subjected to quality inspection and testing before dispatch to the customer. The GHG emissions that occurred during the entire hot rolling process are very low because of following elements are implemented. 1. Electrical power used for operations of blooming mill, finish rolling mill, hot saw cutting, overhead cranes, manipulators, descalers and electrical annealing furnaces is generated from renewable energy sources such as solar power, wind mill power or hydro power etc. 2. The fuel used in soaking pit and walking beam furnace is biodiesel which has near zero GHG emissions. 3. Material movement of finish rolled products and cast steel products is carried out by EV forklifts and cranes.
[0070] In yet another embodiment, the disclosed method (100) helps to minimize the GHG emissions that occur during the entire process chain of steelmaking. Using the proposed method (100) of steel manufacturing route, all types of steel including low carbon, medium carbon, high carbon, high-strength low-alloy (HSLA), low alloy steel, high alloy steel, stainless steel, FE-based super alloy & tool and die steel, valve steel can be effectively produced. Individual elemental range is specified in the table below. The entire range of various chemical compositions of the steel grades that can be produced will be a subset of the elemental range. The below table 2 encompasses all the types of steel and ferrous alloys.
Table 2:
Element C Mn Si S P Cr Ni Mo Al Ti
Range (Wt%) 0.005 – 1.5 0 - 30 0 - 5 0 - 0.9 0 - 0.9 0 - 30 0 - 45 0 - 15 0 - 10 0 – 5
Element V Nb W Cu Pb Sn Te Ca Co Ta
Range
(Wt%) 0 - 10 0 - 10 0 - 10 0 - 10 0 - 0.5 0 - 0.5 0 - 0.5 0 - 0.5 0 - 5 0 - 0.1
Element Sb Ce La Zr Zn O H N As B
Range
(Wt%) 0 - 0.1 0 - 0.1 0 - 0.1 0 - 0.1 0 - 0.1 0 - 0.05 0 - 0.01 0 - 1 0 - 0.5 0 - 0.5

[0071] In yet another embodiment, the disclosed method (100) is further illustrated with the help of the following example.
[0072] Example: the GHG emissions that occur during crude steelmaking are highly dependent on the manufacturing route. There are six steel-making routes (as mentioned in table 3) through which the cast steel is prepared for the hot rolling process. Further, depending on the supply size, the cast steel is subjected to single-rolling or double-rolling. In the double rolling process, rolled bars after first rolling are reheated in WBF and subjected to second rolling. Hence, GHG emissions vary for single and double-rolled products. The below table 3 lists the range of GHG emissions with respect to crude steel production routes as well as single or double rolling processes.
 
Table 3:
Rolled steel emissions
Route
No. Crude Steel Route tCO2e/MT rolled steel
Single Roll Double Roll
1 IF- IC 0.040-0.050 0.050-0.060
2 IF- CC 0.020-0.030 0.035-0.045
3 IF-LF-VD- IC 0.050-0.065 0.070-0.080
4 IF-LF-VD-CC 0.035-0.045 0.050-0.060
5 EAF- LF-VD/VOD-IC 0.250-0.265 0.265-0.280
6 EAF-LF-VD/VOD-CC 0.220-0.235 0.235-0.250

[0073] In yet another embodiment, the real-world applications of the disclosed system (200) and method (100) are illustrated herein below.
[0074] Example (Steel manufacturing plants): The system (202) can be integrated into rolled steel products manufacturing plants that focus on reducing greenhouse gas emissions. Traditional rolled steel production methods generate significant carbon emissions, whereas the described system (202) can utilize renewable energy sources, electric vehicles for transportation, and optimized heating and cooling techniques to minimize environmental impact.
[0075] Further, the system (200) and the method (100) can be implemented in various industries where the rolled steel manufacturing is required with reduced GHG emission such as but not limited to automobile industry, construction and infrastructure, aerospace industry, pipelines and oil industry or gas industry.
[0076] What are described above are merely preferred embodiments of the present disclosure, and are not to limit the present disclosure. Any modification, equivalent replacement, and improvement within the principle of the present disclosure should be included in the protection scope of the present disclosure.
[0077] Since the subject matter of the dependent claims in relation to the prior art on the priority date may form separate and independent disclosures, the applicant reserves the right to make them the subject matter of independent claims or divisional declarations. They may furthermore also contain independent disclosures that have a configuration that is independent of the subject matters of the preceding dependent claims.
[0078] Further, elements and/or features of different example embodiments may be combined with each other and/or substituted for each other within the scope of this disclosure and appended claims.

ADVANTAGES OF THE DISCLOSURE
[0079] The proposed disclosure provides a system and a method for producing green rolled steel products with very low greenhouse gas emission intensity using renewable energy sources.
[0080] The proposed disclosure provides a system and a method that uses low-emission fuel to align with global sustainability goals.
[0081] The proposed disclosure provides a system and a method that addresses GHG emissions across all scopes and ensures a significant reduction in the overall carbon footprint of rolled steel production.
[0082] The proposed disclosure provides a system and a method that produces a wide range of rolled steel product grades, low carbon, medium carbon, high carbon, High-Strength Low-Alloy (HSLA), low alloy steel, high alloy steel, stainless steel, FE-based super alloy & tool and die steel, and valve steel, making it suitable for various industrial applications.
, Claims:1. A method (100) of producing green rolled steel, the method (102) comprising:
obtaining (102) crude steel from a casting unit (204) by a casting process;
selecting (104) a heating unit (206) based on the casting process applied to the obtained crude steel;
heating (106), by the selected heating unit (206), the obtained crude steel;
transferring (108) the heated crude steel to a blooming mill (208) for initial deformation, wherein the blooming mill (208) deforms the heated crude steel to a pre-determined initial size;
hot rolling (110), by a finish rolling unit (210), the pre-deformed steel until the pre-determined final size is achieved;
cutting (112), by a cutting unit (212), the rolled steel to obtain a set of rolled bars to a pre-determined length; and
cooling (114), by a cooling unit (214), the set of rolled bars, thereby obtaining the green rolled steel.

2. The method (100) as claimed in claim 1, wherein the heating unit (206), the blooming mill (208), the finish rolling unit (210), the cutting unit (212), the cooling unit (214) and transferring means (216) are operated using a power supply generated from a renewable energy source selected from any or a combination of solar power, biodiesel, green hydrogen, wind energy, and hydropower.

3. The method (100) as claimed in claim 1, wherein the casting process is selected from any or a combination of routes- induction furnace (IF-CC/IC), induction furnace - ladle furnace - vacuum degassing (IF-LF-VD-CC/IC), and electric arc furnace - ladle furnace - vacuum degassing/vacuum oxygen decarburization (EAF-LF-VD/VOD-CC/IC).

4. The method (100) as claimed in claim 1, wherein the heating unit (206) is selected from any or a combination of soaking pit and walking beam furnace (WBF), rotary hearth furnace (RHF), and regenerative heating furnace.

5. The method (100) as claimed in claim 1, wherein the cutting unit (212) is selected from any or a combination of hot saw machine, shearing machine, plasma cutting, laser cutting, oxy-fuel cutting, and water jet cutting.

6. The method (100) as claimed in claim 1, wherein the finish rolling unit (210) is selected from any or a combination of blooming mill, rolling mill, continuous rolling mill, planetary rolling mill, cross rolling mill, ring rolling mill, skew rolling mill, and two-high or four-high rolling mill.

7. The method (100) as claimed in claim 1, wherein the cooling unit (214) is selected from any or a combination of air cooling, box cooling, furnace cooling or annealing, water quenching, stress relieving, spray cooling, controlled cooling beds, mist cooling, oil quenching, and polymer quenching.

8. The method (100) as claimed in claim 1, wherein temperature of the heating unit (206) ranges between 700°C to 1350°C and the pre-determined initial size and the pre-determined final size ranges between 5 mm to 800 mm having shape of round, round corner square, and square.

9. The method (100) as claimed in claim 1, wherein the green rolled steel is selected from any or a combination of low carbon, medium carbon, high carbon, High-Strength Low-Alloy (HSLA), low alloy steel, high alloy steel, stainless steel, FE-based super alloy and tool, die steel, and valve steel.

10. A system (202) to produce green rolled steel, the system (202) comprising:
a casting unit (204) to obtain crude steel from different types of casting processes;
a heating unit (206) to heat the obtained crude steel, wherein the heating means is selected based on the type of casting process applied to the obtained crude steel;
a transferring means (216) to transfer the heated crude steel to a blooming mill (208) for deformation, wherein the blooming mill (208) deforms the heated crude steel to a pre-determined initial size;
a finish rolling unit (210) to hot roll the pre-deformed steel until the pre-determined final size is achieved;
a cutting unit (212) to cut the rolled steel to obtain a set of rolled bars to a pre-determined length; and
a cooling unit (214) to cool the set of rolled bars, thereby obtaining the green rolled steel.