Effect of applying a full oxygen blast furnace on carbon emissions based on a carbon metabolism calculation model

Abstract

Abstract In this study, the effects of applying a full oxygen blast furnace (FOBF) on carbon emissions were investigated by determining the ultimate minimum carbon consumption and a carbon metabolism calculation model. The results demonstrate that the minimum coke ratio of the top gas circulation-FOBF (TGR-FOBF) is significantly reduced (from 270 to 207 kg·thm−1) compared to that of the traditional ironmaking blast furnace (TBF). Owing to the complete recycling of the furnace top gas of the TGR-FOBF, the degree of direct reduction of TGR-FOBF significantly decreased to 0.14. The replacement of the TGR-FOBF with the three TBFs significantly reduced the CO2 emissions, which were the highest at 1.761 t-CO2/t-CS. Most of the CO2 emissions were generated by the direct combustion emissions (CDE) and direct process emissions (PDE), with a small amount generated by the electricity indirect emissions (EIE). The CO2 emissions generated by CDE, PDE, and EIE were 0.872 t-CO2/t-CS, 0.840 t-CO2/t-CS, and 0.049 t-CO2/t-CS, respectively. As the amount of TGR-FOBF replaced with the three TBFs increased, the CO2 emissions generated by the CDE and PDE significantly decreased. When all three TBFs were replaced with TGR–FOBF, the CO2 emissions generated by the CDE and PDE decreased to extremely low levels of 0.267 t-CO2/t-CS and 0.065 t-CO2/t-CS, respectively.