Analysis of Energy Consumption and Carbon Emissions in Blast Furnaces: Formation Mechanisms and Optimization Strategies
摘要
The blast furnace (BF) ironmaking process is one of the most energy- and carbon-intensive stages in steel production, making it critical for achieving carbon and energy reduction in the iron and steel industry. This study proposes an equipment-oriented microscopic material and energy flow (MEF) analysis method to identify energy- and carbon-reduction pathways in the BF. The BF is divided into functional zones based on thermochemical characteristics, and a hybrid model integrating heat balance constraints with data-driven approaches is established. Using this model, the internal MEF is analyzed to elucidate mechanisms of energy consumption and carbon emissions. Subsequently, the carbon and energy saving potential of five improvement measures (Case 1–Case 5) is evaluated to identify effective strategies for reducing BF carbon emissions and energy consumption. The results show that the tuyere zone (TZ) and high temperature zone (HTZ) consume over 94 pct of the carbonaceous energy, while 41.68 pct of this energy is carried away by the blast furnace gas (BFG) and slag. Moreover, the thermal efficiency of these two zones is significantly lower than that of other zones. The Case study indicates that Case 5 achieves the best comprehensive effect in carbon and energy saving potentials, with values of 21.42 kgCO2/tHM and 11.62 kgce/tHM, respectively. This is followed by Case 2, which achieves carbon reduction of 24.90 kgCO2/tHM and an energy saving of 5.08 kgce/tHM. These results demonstrate that enhancing slag waste heat recovery and improving gas utilization efficiency are two highly effective strategies for reducing the BF’s carbon emission and energy consumption.