TY - BOOK

T1 - Pathways to climate-neutral EAF Steel Production based on Energy Efficiency and Integration of Renewable Energy

AU - Dock, Johannes

N1 - no embargo

PY - 2023

Y1 - 2023

N2 - The iron and steel industry is accountable for a major share of global carbon dioxide emissions. Meeting the targets of the United Nations and the European Union to mitigate global warming requires a sharp reduction in greenhouse gas emissions. The transition from coal to renewable electric power as the main energy source allows for a major reduction of carbon dioxide emissions in steel production. This suggests a shift from the integrated process route involving blast furnace and converter to electric arc furnace-based production processes. The production of primary steel via direct reduction and secondary steel via the recycling of steel scrap enables low-carbon dioxide steelmaking. Both process routes entail the operation of an EAF steel mill. Electric steel production is characterized by a high share of electric power in the total energy consumption. Thus, the provision of renewable electricity for the operation of the electric arc furnace and other aggregates represents an initial step towards carbon dioxide neutral steel production. However, a considerable amount of energy is supplied in the form of fossil fuels such as natural gas and coal. Three approaches are considered for reducing direct carbon dioxide emissions from the combustion of fossil fuels: fuel saving, carbon capture and substitution of energy carriers. The optimal implementation and the evaluation of these measures demands a holistic consideration of the entire production process, its energy supply and its interaction with the overall energy system. Within the scope of the present thesis, potential approaches to reduce carbon dioxide emissions in electric steel production were investigated. First, a component- and time-resolved energy system model of an existing EAF steel mill was created based on measured data. This model generates energy-related key performance indicators and load profiles of energy carriers and industrial gases. Second, the energy system model was utilized to perform a techno-economic evaluation of a range of proposed energy efficiency and carbon dioxide emission reduction measures. Third, an optimization model was developed to analyze different options for flexible on-site production of oxygen, hydrogen and synthetic natural gas. Thus, the impact of the electricity price-driven operation of a power-to-gas plant on the steel mill and the overall energy system was analyzed. Based on the defined research questions, the proposed options were assessed with regard to energy consumption, demand-side flexibility, carbon dioxide emission reduction and economic viability. Eventually, the thesis outlines a potential pathway leading to the carbon dioxide-neutral energy supply of an EAF steel mill and identifies the enabling framework.

AB - The iron and steel industry is accountable for a major share of global carbon dioxide emissions. Meeting the targets of the United Nations and the European Union to mitigate global warming requires a sharp reduction in greenhouse gas emissions. The transition from coal to renewable electric power as the main energy source allows for a major reduction of carbon dioxide emissions in steel production. This suggests a shift from the integrated process route involving blast furnace and converter to electric arc furnace-based production processes. The production of primary steel via direct reduction and secondary steel via the recycling of steel scrap enables low-carbon dioxide steelmaking. Both process routes entail the operation of an EAF steel mill. Electric steel production is characterized by a high share of electric power in the total energy consumption. Thus, the provision of renewable electricity for the operation of the electric arc furnace and other aggregates represents an initial step towards carbon dioxide neutral steel production. However, a considerable amount of energy is supplied in the form of fossil fuels such as natural gas and coal. Three approaches are considered for reducing direct carbon dioxide emissions from the combustion of fossil fuels: fuel saving, carbon capture and substitution of energy carriers. The optimal implementation and the evaluation of these measures demands a holistic consideration of the entire production process, its energy supply and its interaction with the overall energy system. Within the scope of the present thesis, potential approaches to reduce carbon dioxide emissions in electric steel production were investigated. First, a component- and time-resolved energy system model of an existing EAF steel mill was created based on measured data. This model generates energy-related key performance indicators and load profiles of energy carriers and industrial gases. Second, the energy system model was utilized to perform a techno-economic evaluation of a range of proposed energy efficiency and carbon dioxide emission reduction measures. Third, an optimization model was developed to analyze different options for flexible on-site production of oxygen, hydrogen and synthetic natural gas. Thus, the impact of the electricity price-driven operation of a power-to-gas plant on the steel mill and the overall energy system was analyzed. Based on the defined research questions, the proposed options were assessed with regard to energy consumption, demand-side flexibility, carbon dioxide emission reduction and economic viability. Eventually, the thesis outlines a potential pathway leading to the carbon dioxide-neutral energy supply of an EAF steel mill and identifies the enabling framework.

KW - EAF-Stahlproduktion

KW - Energieeffizienz

KW - Demand Side Management

KW - Carbon Capture and Utilization

KW - Oxyfuel-Verbrennung

KW - Power-to-Gas

KW - EAF steel production

KW - Energy efficiency

KW - Demand side management

KW - Carbon capture and utilization

KW - Oxyfuel combustion

KW - Power-to-Gas

U2 - 10.34901/mul.pub.2023.56

DO - 10.34901/mul.pub.2023.56

M3 - Doctoral Thesis

ER -