Decarbonising the iron and steel sector for a 2 °C target using inherent waste streams

Yongqi Sun , Sicong Tian , Philippe Ciais (1, 2) , Zhenzhong Zeng , Jing Meng , Zuotai Zhang

1 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
2 OVSQ - Observatoire de Versailles Saint-Quentin-en-Yvelines

The decarbonisation of the iron and steel industry, contributing approximately 8% of current global anthropogenic CO₂ emissions, is challenged by the persistently growing global steel demand and limitations of techno-economically feasible options for low-carbon steelmaking. Here we explore the inherent potential of recovering energy and re-using materials from waste streams, high-temperature slag, and re-investing the revenues for carbon capture and storage. In a pathway based on energy recovery and resource recycling of glassy blast furnace slag and crystalline steel slag, we show that a reduction of 28.5 ± 5.7% CO₂ emissions to the sectoral 2 °C target requirements in the iron and steel industry could be realized in 2050 under strong decarbonization policy consistent with low warming targets. The technological schemes applied to engineer this high-potential pathway could generate a revenue of US$35 ± 16 and US$40 ± 18 billion globally in 2035 and 2050, respectively. If this revenue is used for carbon capture and storage implementation, equivalent CO₂ emission to the 2 °C sectoral target requirements is expected to be reduced before 2050, without any external investments.

Domains: Sciences of the Universe [physics]; Earth Sciences

Yongqi Sun, Sicong Tian, Philippe Ciais, Zhenzhong Zeng, Jing Meng, et al.. Decarbonising the iron and steel sector for a 2 °C target using inherent waste streams. Nature Communications, 2022, 13, pp.297. ⟨10.1038/s41467-021-27770-y⟩. ⟨insu-03721935⟩