Search Results (28)

The iron and steel industry is one of the largest industrial sources of greenhouse gas emissions. This paper examines the potential of green hydrogen as a reducing agent for decarbonizing primary steel production, focusing on the Taranto integrated steelworks in southern Italy. Producing about 3.5 Mt of crude steel annually, the plant is also among the country’s biggest emitters, with CO₂ emissions of roughly 8 Mt per year at typical blast furnace intensity (2.2 tCO₂/t steel). The analysis quantifies the hydrogen demand required to replace fossil fuels in iron ore reduction and evaluates the techno-economic feasibility of meeting it with green hydrogen. Using DWSIM (open-source chemical process simulation software, v9.0.2) for water electrolysis powered by renewables, the study estimates both the CO₂ emission reductions and cost impacts of hydrogen-based steelmaking. Results show that integrating green hydrogen at Taranto could achieve deep decarbonization by cutting emissions by over 90%, with a base-case levelized hydrogen cost (LCOH) of 3.6 EUR/kg and green steel production cost 653 EUR/t. With optimistic assumptions (renewable electricity at 40 EUR/MWh and electrolyzer CAPEX halved to 500 EUR/kW), hydrogen cost could be reduced to 2.3 EUR/kg, making green steel cost-competitive with conventional steel and implying a breakeven carbon price of under 60 EUR/t. Sensitivity analyses highlight that falling renewable electricity prices, supportive carbon policies, and successful demonstration projects are key enablers for economic viability. The findings underscore that renewable hydrogen can be a viable decarbonization pathway for steel when coupled with continued technological improvements and policy support. Full article

The global steel industry emits 1.92 tons of CO₂ per ton of output and faces urgent pressure to decarbonize. In Pakistan, the sector accounts for 0.29 tons of CO₂ per ton of output, with limited mitigation frameworks in place. Green hydrogen (GH2)-based steelmaking offers a strategic pathway toward decarbonization. However, realizing its potential depends on access to renewable energy. Despite Pakistan’s substantial technical wind potential of 340 GW, grid limitations currently restrict wind power to only 4% of national electricity generation. This study explores GH₂ production through sector coupling and power wheeling, repurposing curtailed wind energy from Sindh to supply Karachi’s steel industry, and proposing a phased roadmap for GH, enabling fossil fuel substitution, industrial resilience, and alignment with global carbon-border regulations. Full article

Hydrogen-based direct reduction of iron ore is a promising route to reduce CO₂ emissions in steelmaking, where uniform particle flow inside shaft furnaces is essential for efficient operation. In this study, a full-scale three-dimensional Discrete Element Method (DEM) model of a shaft furnace was developed to investigate the effects of a diverter device on granular flow. By systematically varying the radial width and top/bottom diameters of the diverter, particle descent velocity, residence time, compressive force distribution, and collision energy dissipation were analyzed. The results demonstrate that introducing a diverter effectively suppresses funnel flow, prolongs residence time, and improves radial flow uniformity. Among the tested configurations, the smaller central diameter diverter showed the most favorable performance, achieving a faster and more uniform descent, reduced compressive force concentration, and lower collision energy dissipation. These findings highlight the critical role of diverter design in regulating particle dynamics and provide theoretical guidance for optimizing shaft furnace structures to enhance the efficiency of hydrogen-based direct reduction processes. Full article

Electric arc furnace slag is a major by-product of steelmaking, yet its industrial utilization remains limited due to its complex chemical and mineralogical composition. This study presents a hydrogen-based approach to recover metallic components from EAF slag for potential reuse in steelmaking. Laboratory experiments were conducted by melting 50 g of industrial slag samples at 1600 °C and injecting hydrogen gas through a ceramic tube into the liquid slag. After cooling, both the slag and the metallic phases were analyzed for their chemical and phase compositions. Additionally, the reduction process was modeled using a combination of approaches, including the thermochemical software FactSage 8.1, models for density, surface tension, and viscosity, as well as a diffusion model. The injection of hydrogen resulted in the reduction of up to 40% of the iron oxide content in the liquid slag. In addition, the fraction of reacted hydrogen gas was calculated. Full article

The production of iron and steel plays a significant role in the anthropogenic carbon footprint, accounting for 7% of global GHG emissions. In the context of CO₂ mitigation, the steelmaking industry is looking to potentially replace traditional carbon-based ironmaking processes with hydrogen-based direct reduction of iron ore in shaft furnaces. Before industrialization, detailed modeling and parametric studies were needed to determine the proper operating parameters of this promising technology. The modeling approach selected here was to complement REDUCTOR, a detailed finite-volume model of the shaft furnace, which can simulate the gas and solid flows, heat transfers and reaction kinetics throughout the reactor, with an extension that describes the whole gas circuit of the direct reduction plant, including the top gas recycling set up and the fresh hydrogen production. Innovative strategies (such as the redirection of part of the bustle gas to a cooling inlet, the use of high nitrogen content in the gas, and the introduction of a hot solid burden) were investigated, and their effects on furnace operation (gas utilization degree and total energy consumption) were studied with a constant metallization target of 94%. It has also been demonstrated that complete metallization can be achieved at little expense. These strategies can improve the thermochemical state of the furnace and lead to different energy requirements. Full article

Vacuum degassing (VD) is a critical refining step in electric arc furnace (EAF) steelmaking for producing clean steel with reduced nitrogen and hydrogen content. This study develops an Effective Equilibrium Reaction Zone (EERZ) model focused on denitrogenation (de-N) by simulating interfacial reactions at the bubble–steel interface (Z1). The model incorporates key process parameters such as argon flow rate, vacuum pressure, and initial nitrogen and sulfur concentrations. A robust empirical correlation was established between de-N efficiency and the mass of Z1, reducing prediction time from a day to under a minute. Additionally, the model was further improved by incorporating a dynamic surface exposure zone (Z_eye) to account for transient ladle eye effects on nitrogen removal under deep vacuum (<10 torr), validated using synchronized plant trials and Python-based video analysis. The integrated approach—combining thermodynamic-kinetic modeling, plant validation, and image-based diagnostics—provides a robust framework for optimizing VD control and enhancing nitrogen removal control in EAF-based steelmaking. Full article

Amid escalating global climate crises and the urgent imperative to meet the Paris Agreement’s carbon neutrality targets, the steel industry—a leading contributor to global greenhouse gas emissions—confronts unprecedented challenges in driving sustainable industrial transformation through innovative low-carbon steelmaking technologies. This paper examines decarbonization technologies across three stages (source, process, and end-of-pipe) for two dominant steel production routes: the long process (BF-BOF) and the short process (EAF). For the BF-BOF route, carbon reduction at the source stage is achieved through high-proportion pellet charging in the blast furnace and high scrap ratio utilization; at the process stage, carbon control is optimized via bottom-blowing O₂-CO₂-CaO composite injection in the converter; and at the end-of-pipe stage, CO₂ recycling and carbon capture are employed to achieve deep decarbonization. In contrast, the EAF route establishes a low-carbon production system by relying on green and efficient electric arc furnaces and hydrogen-based shaft furnaces. At the source stage, energy consumption is reduced through the use of green electricity and advanced equipment; during the process stage, precision smelting is realized through intelligent control systems; and at the end-of-pipe stage, a closed-loop is achieved by combining cascade waste heat recovery and steel slag resource utilization. Across both process routes, hydrogen-based direct reduction and green power-driven EAF technology demonstrate significant emission reduction potential, providing key technical support for the low-carbon transformation of the steel industry. Comparative analysis of industrial applications reveals varying emission reduction efficiencies, economic viability, and implementation challenges across different technical pathways. The study concludes that deep decarbonization of the steel industry requires coordinated policy incentives, technological innovation, and industrial chain collaboration. Accelerating large-scale adoption of low-carbon metallurgical technologies through these synergistic efforts will drive the global steel sector toward sustainable development goals. This study provides a systematic evaluation of current low-carbon steelmaking technologies and outlines practical implementation strategies, contributing to the industry’s decarbonization efforts. Full article

It is essential to evaluate the prospective development trends of coke dry quenching (CDQ) waste heat power generation, to reduce the comprehensive cost of the steelmaking system. Based on TIMES energy system optimization model, this study develops a model of China’s iron and steel production. Three scenarios are established, predictions and comparisons are conducted regarding the iron and steel production structure, total CDQ quantity, CO₂ and pollutant emissions under these scenarios. The findings indicate that: (1) The advancement of hydrogen metallurgy and EAF scrap smelting facilitates a reduction in the quantity of BF-BOF steelmaking and total CDQ consumption. (2) The decreasing demand for CDQ shows that the shift to clean production alters process pathways and compels the energy system from scale-driven to flexibility-focused. (3) The marginal value of the CDQ system is contingent upon the targeted policy support for multi-energy co-generation systems and their deep integration with hydrogen infrastructure. Accordingly, the utilization of CDQ waste heat power generation should be considered as a transitional strategy, it will be imperative to implement a reduction in capacity. Full article

Against the backdrop of global energy crises and climate change, the iron and steel industry, as a typical high energy consumption and high-emission sector, faces rigid constraints for energy conservation and emission reduction. This paper systematically reviews the research progress and application effects of energy-saving technologies across the entire steel production chain, including coking, sintering, ironmaking, steelmaking, continuous casting, and rolling processes. Studies reveal that technologies such as coal moisture control (CMC) and coke dry quenching (CDQ) significantly improve energy utilization efficiency in the coking process. In sintering, thick-layer sintering and flue gas recirculation (FGR) technologies reduce fuel consumption while enhancing sintered ore performance. In ironmaking, high-efficiency pulverized coal injection (PCI) and hydrogen-based fuel injection effectively lower coke ratios and carbon emissions. Integrated and intelligent innovations in continuous casting and rolling processes (e.g., endless strip production, ESP) substantially reduce energy consumption. Furthermore, the system energy conservation theory, through energy cascade utilization and full-process optimization, drives dual reductions in comprehensive energy consumption and carbon emission intensity. The study emphasizes that future advancements must integrate hydrogen metallurgy, digitalization, and multi-energy synergy to steer the industry toward green, high-efficiency, and low-carbon transformation, providing technical support for China’s “Dual Carbon” goals. Full article

In the context of the “carbon peaking and carbon neutrality” era, China’s steel industry, as one of the pillars of the national economy, must accelerate the exploration and adoption of innovative production processes to effectively reduce its carbon footprint. The numerical simulation of hydrogen-based shaft furnaces is an important method for studying the internal characteristics of steelmaking processes. Its objective is to set reasonable furnace parameters to significantly enhance production efficiency and environmental friendliness, ensuring that sustainability and economic benefits coexist in the steel manufacturing process. In order to develop a new shaft furnace, which simplifies the cooling parts, the mathematical model was used to conduct a numerical simulation analysis of hydrogen-based shaft furnaces. The Discrete Element Method (DEM) was employed to focus on the stress and wear behavior of internal components within the hydrogen-based shaft furnace. The results indicated that during the charging of iron ore pellets, the outlet area experienced friction and compression from Direct Reduced Iron (DRI), resulting in a maximum stress of 47,422.1 Pa at the output section. The stresses on the loosening roller were locally concentrated due to its clockwise rotational motion, with a maximum shear stress of 219,896.1 Pa. By applying the Archard wear theory and the moving bed model, the theoretical wear degrees of the refractory materials in the reduction section and the steel shell in the cooling section were obtained; the monthly wear rate of the loosening roller was approximately 0.601 mm. Reasonably setting the parameters and feeding speed of the hydrogen-based shaft furnace can optimize the force and wear conditions of internal components, achieving optimal operating conditions. This provides a reference for factories to effectively extend the service life of hydrogen-based shaft furnaces and offers reasonable suggestions for the future industrial application of hydrogen metallurgy. Full article

Iron-based oxygen carriers (OCs) have received much attention due to their low costs, high mechanical strengths and high-temperature stabilities in the chemical looping gasification (CLG) of biomass, but their chemical reactivity is very ordinary. Converter steel slags (CSSs) are steelmaking wastes and rich in Fe₂O₃, CaO and MgO, which have good oxidative ability and good stability as well as catalytic effects on biomass gasification. Therefore, the composite OCs prepared by mechanically mixing CSSs with iron-based OCs are expected to be used to increase the hydrogen production in the CLG of biomass. In this study, the catalytic performance of CSS/Fe₂O₃ composite OCs prepared by mechanically mixing CSSs with iron-based OCs on the gasification of brewers’ spent grains (BSGs) were investigated in a tubular furnace experimental apparatus. The results showed that when the weight ratio of the CSSs in composite OCs was 0.5, the relative volume fraction of hydrogen reached the maximum value of 49.1%, the product gas yield was 0.85 Nm³/kg and the gasification efficiency was 64.05%. It could be found by X-ray diffraction patterns and scanning electron microscope characterizations that the addition of CSSs helped to form MgFe₂O₄, which are efficient catalysts for H₂ production. Owing to the large and widely distributed surface pores of CSSs, mixing them with iron-based OCs was beneficial for catalytic steam reforming to produce hydrogen. Full article

Decarbonizing the iron and steelmaking industry is critical for China to pursue the net-zero emissions target and advance sustainable industrialization (SDG 9). This paper addresses the urgent need for decarbonization strategies in this sector, aiming to align with China’s carbon neutrality goals by 2060. By reviewing the current technological advancements and potential pathways for deep decarbonization, including process optimization, hydrogen-based direct reduction, and carbon capture, utilization, and storage (CCUS), these decarbonization technologies are categorized into six strategic approaches: systemic energy efficiency improvement, resource recycling, process optimization and innovation, breakthrough smelting, product iterative upgrading, and CCUS. These strategies also align with SDG 13 (climate action) by reducing greenhouse gas emissions and SDG 7 (affordable and clean energy) through the promotion of clean energy technologies. These strategies are evaluated for their emission reduction potential and technological maturity. The results indicate that, while efficiency improvements and resource recycling are currently the most mature and widely implemented strategy, significant breakthroughs in hydrogen metallurgy and CCUS are essential for achieving long-term carbon neutrality. Based on an analysis, a comprehensive roadmap is proposed, detailing the near-term to long-term actions required for the industry’s transition. The near-term focus (up to 2030) should be on enhancing energy efficiency and process optimization, whereas the mid-term (2030–2050) focus should emphasize the adoption of hydrogen-based technologies and CCUS. By the 2050–2060 period, the industry should achieve widespread commercialization of breakthrough smelting technologies and CCUS, ensuring the achievement of carbon neutrality. This study intends to provide a systematic framework and strategic recommendations for policymakers and industry stakeholders to guide the decarbonization of China’s iron and steelmaking sector, addressing both technological and economic challenges to achieve sustainable and low-carbon development. Full article

In the context of carbon reduction and emission reduction, the new process of electric arc furnace (EAF) steelmaking based on direct hydrogen reduction is an important potential method for the green and sustainable development of the steel industry. Within an electric furnace for the hydrogen-based direct reduction of iron, after hydrogen-based directly reduced iron (HDRI) is produced through a shaft furnace, HDRI is melted or smelted in an EAF to form final products such as high-purity iron or high-end special steel. As smelting proceeds in the electric furnace, it is easy for pieces of HDRI to bond to each other and become larger pieces; they may even form an “iceberg”, and this phenomenon may then worsen the smelting working conditions. Therefore, the melting of HDRI is the key to affecting the smelting cycle and energy consumption of EAFs. In this study, based on the basic characteristics of HDRI, we established an HDRI melting model using COMSOL Multiphysics 6.0 and studied the HDRI melting process, utilizing pellets with a radius of 8 mm. The results of our simulation show that the HDRI melting process can be divided into three different stages: generating a solidified steel layer, melting the solidified steel layer, and melting HDRI bodies. Moreover, multiple HDRI processes are prone to bonding in the melting process. Increasing the spacing between pieces of HDRI and increasing the preheating temperature used on the HDRI can effectively reduce the aforementioned bonding phenomenon. When the melting pool temperature is 1873 K, increasing the spacing of HDRI to 10 mm and increasing the initial HDRI temperature to 973 K was shown to effectively reduce or eliminate the bonding phenomenon among pieces of HDRI. In addition, with the increase in the melting pool temperature, the time required for melting within the three stages of the HDRI melting process shortened, and the melting speed was accelerated. With the increase in the temperature used to preheat the HDRI, the duration of the solidified steel layer’s existence was also shortened, but this had no significant impact on the time required for the complete melting of HDRI. This study provides a theoretical basis for the optimization of the HDRI process within EAFs. Full article

The mitigation of CO₂ emissions is one of the major areas of research in iron ore-based steelmaking. In this study, four simulated current and potential future reheating scenarios with different fuel and oxidizer gases were studied regarding the amount of oxide formation and the adhesion of the steel–oxide interface: (1) methane–air; (2) coke oven gas–air; (3) hydrogen–air; (4) and an oxyfuel scenario with 50:50 methane/hydrogen as fuel gases. Isothermal oxidation tests were conducted at temperatures of 1150, 1230 and 1300 °C. Four low-carbon steel grades were tested in the previously mentioned gas atmospheres. The structure and composition of the formed oxide scales was analyzed with FESEM-EDS microscopy. The amount of oxide formation correlated with the water vapor content of the gas atmosphere for all four steel grades; however, notable differences were found between individual steel grades regarding the degree of oxidation increase. No clear evidence was found of the gas atmospheres affecting the adhesion of oxide scales to the steel substrate. The adhesion of the interface was mainly determined by the content of silicon in the steel grade and the test temperature. Full article

Hydrogen-based direct reduction is a promising technology for CO₂ lean steelmaking. The electric arc furnace is the most relevant aggregate for processing direct reduced iron (DRI). As DRI is usually added into the arc, the behavior in this area is of great interest. A laboratory-scale hydrogen plasma smelting reduction (HPSR) reactor was used to analyze that under inert conditions. Four cases were compared: carbon-free and carbon-containing DRI from DR-grade pellets as well as fines from a fluidized bed reactor were melted batch-wise. A slag layer’s influence was investigated using DRI from the BF-grade pellets and the continuous addition of slag-forming oxides. While carbon-free materials show a porous structure with gangue entrapments, the carburized DRI forms a dense regulus with the oxides collected on top. The test with slag-forming oxides demonstrates the mixing effect of the arc’s electromagnetic forces. The cross-section shows a steel melt framed by a slag layer. These experiments match the past work in that carburized DRI is preferable, and material feed to the hotspot is critical for the EAF operation. Full article