CO2 gasification of dry quenching dust ash catalyzed in situ by soot

Abstract

It's imperative to reduce the CO2 emissions in iron and steel manufacturing and improve the reaction rate of the CO2 gasification of dry quenching dust ash (DQDA). In this study, a new technology is proposed in which the CO2 gasification of DQDA is catalyzed by high-temperature soot (HS) in the high-temperature flue gas of a converter. In the experiments, a composite catalyst (FeO: Fe2O3 = 5:2) was used to stimulate the main Components of HS. The influence of the main components of HS (FeO, Fe2O3) on DQDA gasification with CO2 was evaluated by thermodynamic simulation calculation (FactSage 6.1), thermo-gravimetric analysis, and drop-tube furnace experiments at high temperatures. In addition, the catalytic efficiency was quantitatively evaluated by the α and β values, LHVs, and kinetic analyses using homogeneous and shrinking-core models. The results indicated that the HS has significant catalytic effects on the CO2 gasification of DQDA, and exhibited differing characteristics. The catalytic efficiency increased with temperature. At 1200 °C, the consumption of CO2 was increased from 24.13% without a catalyst to 30.76% with the HS composite catalysts. As a result, Fe, FeO, and Fe3C were the most common solid products catalyzed by HS. Experiments proved the new technology's practicality.