Thermodynamic simulations of the H2S removal from blast furnace gas by metal oxides were conducted to select a suitable metal desulfurizer. Notably, the Mn oxides demonstrated themselves as the optimal H2S removal agents. They are characterized by the absence of radioactive pollution, high cost-effectiveness, high sulfur fixation potential, and non-reactivity with CO2, CO, and CH4. Through a comprehensive comparison of Mn oxides, the sulfur fixation potential and sulfur capacity were elucidated as follows: Mn3O4 > Mn2O3 > MnO2 > MnO. The higher-valence manganese oxides were shown to have stronger oxidation ability, larger sulfur capacity, and the advantage of producing elemental sulfur with high utilization value during the reaction. After selecting Mn oxides as the optimal H2S removal agents, an equilibrium component analysis of the regeneration process of the sulfided MnS was carried out. The results indicate that an oxygen amount that is 1.5 times that of MnS is the optimal dosage, and such an amount can oxidize all of the MnS at a relatively low temperature. Conversely, a diluted oxygen concentration can further reduce the temperature of the regeneration process, preventing the sintering of the regenerated desulfurizer and thus maintaining its reusability. This research provides a sufficient theoretical basis for the use of Mn oxides as active components of desulfurizers to remove H2S from blast furnace gas and for the regeneration of MnS after desulfurization.
Keywords: Gibbs free energy variation; H2S removal; metal oxide; reaction products regulation; thermodynamic simulation.