Abstract:
As a pillar of the national economy, the iron and steel industry is both energy-intensive and a primary source of global carbon emissions. In the context of global climate mitigation and China’s “Dual Carbon” targets, the product carbon footprint (PCF) has emerged as a critical metric determining competitiveness in international trade and supply chains. Given the high carbon intensity per unit of product, the Chinese steel industry faces significant challenges in achieving sustainable development. This study employs life cycle assessment (LCA) to quantify the PCFs of three typical crude steel production routes: the blast furnace–basic oxygen furnace (BF–BOF) long process, an electric arc furnace (EAF) short process with 45% scrap input, and a full-scrap EAF short process. Furthermore, using the grid emission factor method, this study calculated and analyzed annual electricity carbon footprint factors at regional and provincial levels in China from 2018 to 2022, thereby establishing a localized dataset for electricity carbon intensity. Results indicate that electricity consumption is a critical determinant of carbon emissions in steel manufacturing, with the contribution of electricity-related emissions varying significantly across routes: approximately 7% for BF–BOF, 20% for the 45% scrap EAF, and rising to 58% for the full-scrap EAF. Moreover, significant discrepancies were observed between PCFs calculated using localized electricity factors and those derived from commercial databases such as Ecoinvent. For the full-scrap EAF route, this deviation reached 35%, underscoring the need to use region-specific emission factors for accurate PCF accounting. Additionally, significant spatial heterogeneity exists in regional and provincial power structures. In hydropower-dominant southwestern China, the electricity carbon footprint factor remained below 0.40 kg·kW
–1·h
–1, whereas in coal-reliant northern and eastern regions, it exceeded 1.00 kg·kW
–1·h
–1, exhibiting a spatial pattern of “high in the north and east, low in the south and west.” From 2018 to 2022, these factors showed a general downward trend, reflecting the emission reduction benefits of increased clean energy generation. Sensitivity analysis indicates that a 0.1 kg·kW
–1·h
–1 decrease in the electricity factor reduces the PCF of the full-scrap EAF route by approximately 50–70 kg·t
–1, confirming the substantial impact of optimizing the power structure on the industry’s decarbonization potential. By systematically quantifying the relationship between electricity factors and steel PCFs, this study elucidates the spatial and temporal trends of China’s electricity carbon footprint factors. It further quantifies the influence of these factors across different steelmaking processes, confirming that localized factors are essential for improving the accuracy and regional comparability of PCF accounting. These findings provide empirical data and methodological references to support the low-carbon transformation of the steel industry, optimization of production capacity layout, and enhancement of regional energy planning.