Assessment of decarbonization pathways for the steel industry using process simulation

As a significant contributor to industrial CO2 emissions, the iron and steel industry needs to adopt CO2-lean technologies to align with the European Green Deal’s target of carbon neutrality by 2050. Process simulation aids in assessing potential decarbonization strategies. This paper investigates a hypothetical stepwise transformation of the steel mill Linz using the flowsheet simulation software gPROMS (General PROcess Modeling System). The transition from the traditional blast furnace-basic oxygen furnace route to an electric arc furnace-based steelmaking process is modelled, integrating hydrogen-based direct reduction, electric smelting furnace, as well as carbon capture, utilization, and storage technologies. A comprehensive analysis of energy streams, including shifts in external energy demand for electricity, natural gas, and hydrogen, is carried out for each potential future scenario. Moreover, the impacts on the steam network, energy surpluses, and Operational Expenditures are assessed. While each transformation scenario lowers direct CO2 emissions, electricity and hydrogen demand rise significantly, increasing operational costs. The results provide valuable insights into the evolving energy requirements and economic challenges the European steel industry is facing on its path to sustainable production. In particular, the economic feasibility of the decarbonization pathways depends strongly on the scalability of key infrastructure, including access to low-cost renewable electricity, affordable green hydrogen, and sufficiently high CO2 prices.