Green steel production: an overview

Abstract

Iron and steel production supports modern industrialization but is highly energy-intensive and accounts for approximately 7-9% of global CO2 emissions. In the goal of pursuing a carbon-neutral society, significant progress has been made toward green ironmaking technologies, including hydrogen-based reduction, biomass-assisted routes, and electrochemical methods. However, each approach still faces critical challenges, making it difficult to simultaneously achieve high efficiency, truly zero-carbon emissions, and economic viability. In this review, we provide a timely and comprehensive overview of green ironmaking strategies based on different reductants, including carbon, hydrogen, and electrons, together with carbon capture and utilization technologies. Owing to their potential to achieve net-zero carbon emissions, particular emphasis is placed on electrochemical ironmaking approaches. Their reaction mechanisms, advantages, limitations, and recent advances are systematically discussed. Furthermore, we highlight the potential of integrated strategies involving in situ hydrogen production and consumption, as well as on-site CO2 recycling, which may provide promising pathways for future green ironmaking. Finally, we present perspectives on the key challenges and opportunities for advancing electrochemical ironmaking technologies toward industrial implementation.