Energy saving analysis for CO2–O2 mixed injection technology in converter steelmaking

Energy-saving in China's iron and steel industry still relies on the development and improvement of short-term energy saving technologies. Therefore, a special converter smelting technology incorporating energy saving was proposed. To evaluate the energy-saving potential of the CO2–O2 mixed injection (COMI) technology, collected production data were used to develop an improved techno-economic model. Calculations reveal that the technology can save energy through auxiliary material consumption, sensible heat of solid by-product, iron loss reduction, and energy recovery. The application of COMI technology in an enterprise is cost effective, involving the energy saving potential of 0.206 GJ/t, the cost of conserved energy of − 48.83 yuan/GJ, and a simple payback period of 0.35 year for a 60-million-yuan investment. Sensitivity analysis shows that the investment cost and discount rate primarily influence the cost of conserved energy of the technology. As the discount rate increased, the cost of conserved energy also gradually increased. Overall, the COMI technology is an energy-saving technology with good development prospects.