Tracking Carbon Flows in China’s Iron and Steel Industry

Accurately tracking carbon flows is the first step toward reducing the climate impacts of the iron and steel industry (ISI), which is still lacking in China. In this study, we track carbon flows from coal/mineral mines to end steel users by coupling the cross-process material and energy flow model, point-based emission inventory, and interprovincial trade matrices. In 2020, ISI emitted 2288 Tg of CO₂ equivalent (CO₂eq, including CH₄ and CO₂), 96% of which came from energy use and 4% from raw material decomposition. Often overlooked off-gas use and CH₄ leakage in coal mines account for 25% of life-cycle emissions. Due to limited scrap resources and a high proportion of pig iron feed, the life-cycle emission intensity of the electric arc furnace (EAF) (1.15 t CO₂eq/t steel) is slightly lower than the basic oxygen furnace (BOF) (1.58 t CO₂eq/t steel) in China. In addition, over 49% of producer-based emissions are driven by interprovincial coal/coke/steel trade. In particular, nearly all user-based emissions in Zhejiang and Beijing are transferred to steelmaking bases. Therefore, we highlight the need for life-cycle and spatial shifts in user-side carbon management.