Systematic power decarbonization strategies for sustainable steel manufacturing: an integrated modeling framework combining process regulation and technology integration

Achieving an economically feasible low-carbon transition is critical for the steel industry. Electricity serves as a central energy carrier in steel manufacturing, making power decarbonization important to the low-carbon development of this sector. However, existing studies often underrepresent the system-wide propagation effects arising from the coupling between production and power systems, which can bias estimates of decarbonization benefits and associated trade-offs. This study develops an integrated modeling framework to quantify the emission and economic contributions of electricity and to evaluate plant-level power decarbonization strategies based on parameter regulation and low-carbon technology deployment. For the case plant, emissions of the BF-BOF process are 1548.14 kg-CO 2 /t-CS, of which electricity-related emissions account for 24.79% (383.82 kg-CO 2 /t-CS). Energy costs account for 12.08% of the total cost (2739.08 CNY/t-CS). Adjustments to raw-material quality, production organization, and technical parameters can synergistically achieve carbon and cost reduction of the power and production system. Under the specified electricity price, emission factor, and substitution ratio, contractual green-power procurement reduces emissions and may achieve cost parity without carbon-market revenue. The plant-gate CCU scenarios yield substantial emission reductions, but the economics depend on carbon prices, capture costs, and downstream CO 2 utilization revenues. The scrap-EAF route supplied with green electricity can reduce emissions to 35.51 kg-CO 2 /t-CS, though it relies on stable supply of cost-competitive scrap steel. The DRI-based routes remain sensitive to costs and emissions associated with hydrogen production, indicating the necessity of low-cost green hydrogen supply and supportive market conditions.