Desulfurization performance and mechanism for H2S from blast furnace gas over FAU zeolite sorbent.

[Display omitted] • H 2 S in BFG could be adsorbed on Na-type FAU zeolite via two different ways. • H 2 S could be adsorbed on bridging hydroxyl groups of Na-type FAU zeolite. • H 2 S could interact with Na+ via base-acid interaction over FAU zeolite. • On Na+, H 2 S would be converted to S and further oxidized to SO 4 2− and S 2 O 3 2− by O 2. The desulfurization of blast furnace gas is crucial to meet the strict requirements for clean production of steel industry. However, the composition of blast furnace gas is complicated, and the gases of H 2 O, CO, CO 2 , and O 2 would significantly affect the desulfurization activity. Therefore, the desulfurization performance for H 2 S in simulated blast furnace gas by Na-type FAU zeolites with different Si/Al was investigated. The physicochemical properties of zeolite sorbents were measured, and their correlation with desulfurization performance was studied. Moreover, the adsorption mechanism of H 2 S was investigated. The breakthrough sulfur capacity improved with the increase of relative crystallinity, Na+ content, specific surface area, and the decrease of Si/Al ratio. The adsorption mechanism of H 2 S on Na-type FAU zeolite was proposed. One is the hydrogen bond interaction between the bridging hydroxyl groups and H 2 S, and the other one is the base-acid interaction between sodium ion and H 2 S. In blast furnace gas, when interacting with Na+, H 2 S would be transformed into S, which further oxidized into thiosulfate and sulfate by O 2. [ABSTRACT FROM AUTHOR]