2018 年 58 巻 4 号 p. 776-783
A new process for resource utilization of converter gas is proposed to produce CO2 at a lower cost in this paper. Converter gas is burned in O2–CO2 atmosphere instead of O2–N2 atmosphere in a closed combustion furnace. Flue gas with high concentration of CO2 can be used as low-grade CO2 directly or be purified as raw gas for preparing high-purity CO2. Both the low-grade CO2 and high-purity CO2 can be recycled for the converter blowing and sealing. In order to analyze the combustion characteristics of converter gas, numerical simulations based on a three dimensional combustion furnace model were carried out. Volume fraction of N2 in combustion flue gas dropped from 63.37% to 3.92%, meanwhile CO2 concentration in flue gas reached 95.08% when the N2 in air was totally replaced by CO2. In addition, to control the CO content in flue gas within the safety criterion, lower stoichiometry is an optimal solution for the converter gas compete combustion.