Closed-circulating CO_2 sequestration process evaluation utilizing wastes in steelmaking plant

摘要

The wastes network system exploration in metallurgical process imposes of great significance for advancing green circular economy in steel plant. This paper originally proposes a closed-circulating CO_2 sequestering process for wastes appreciation and harmless disposal, and the effect of two circulation strategy, i.e. Slag circulation strategy and cold-rolling waste water(CRW) circulation strategy, on the CO_2 uptake efficiency, carbonation degree and desalination rate were systemically discussed. Then, their kinetics are analyzed by model and molecular simulation in detail, respectively. In addition, the energy consumption and the cost are simulated for comprehensively evaluating its superiority. The experimental and molecular simulation results all show that the peak values for both strategies could be achieved when circulation times is in the range of three to five. CRW circulation strategy has a better CO_2 uptake efficiency than slag circulation strategy, the CO_2 uptake efficiency is about 487kgCO_2/ tslag and corresponding desalination rate is 48.9%, when CRW is circulated for five times at 60 °C and 20 L/g for 90 min. Adopting CRW circulation strategy, the CO_2 sequestration efficiency is averagely doubled comparing to previous results. 129%-183% energy consumption and 35.6% cost would be reduced, which represents that the proposed routine is economical to step forward to industrial application.