Development of CO 2 capture and utilization technology in steelmaking plant

The performance of a recycling process for CO 2 capture and utilization of exhaust gas in the steelmaking plant was reported. A facility capable of capturing CO 2 at 3200 m 3 /h was established in the steelmaking plant, resulting in the CO 2 production of 50,000 t/a. The CO 2 concentration of the exhaust gas from the lime kiln increased from 25.0 to 99.8 vol.% using the comprehensive method of the pressure swing adsorption and cryogenic separation. The captured and purified CO 2 was successfully applied in the converter process by the top blowing and bottom blowing. The utilization of CO 2 was 3.5 m 3 /t through these two modes. After optimizing parameters of CO 2 –O 2 mixed top blowing, the value of [C] × [O] and the content of TFe in slag were reduced by 1.33 × 10 −4 and 1.27%, respectively, and the dephosphorization rate of the molten steel increased by 2.31%. For the CO 2 bottom blowing, the [N] content in the molten steel was significantly reduced by 5.7 × 10 −6 .