Techno-Economic Case Study on Oxyfuel Technology Implementation in EAF Steel Mills – Concepts for Waste Heat Recovery and Carbon Dioxide Utilization

Compared to integrated steel production via blast furnace and basic oxygen furnace, the electric arc furnace route saves energy and carbon dioxide emissions. While the major part of the energy is provided in the form of electric power, a substantial fraction of thermal energy is supplied by the combustion of direct fuels.
In the present study, we describe available options for increasing the energy efficiency and cut down on carbon dioxide emissions in electric arc furnace steel mills. Based on these technologies, we develop possible process layouts including the transition to Oxyfuel ladle preheating, on-site utilization of the CO2-rich product gas and off-gas heat as well as the recovery of waste heat from the hot gas duct of the electric arc furnace for process steam production.
With the aid of an energy system model, a case study is carried out to determine the potential for fuel savings as well as carbon dioxide and waste heat utilization. In a technical assessment, we investigate the relationship between the storage capacities, the carbon dioxide and waste heat utilization ratios as well as the fuel and CO2 emission savings. The subsequent economic analysis yields the optimum system layout under different framework conditions.