Adsorption of hydrogen sulfide by iron-based adsorbent derived from fly ash and iron slag

In this article, an innovative sorbent (Fe-FA) is prepared from fly ash; ferrous sulfate-containing waste slag (FSS), which are industrial wastes; and NaOH by a hydrothermal method at 100 °C. As a result, in comparison to several conventional sorbents, such as ZnO, Fe₂O₃, 13X zeolite, and activated carbon, Fe-FA had the best adsorption performance for H₂S adsorption. Fe-FA had not only a higher adsorption capacity (near 150 mg/g) but also a longer breakthrough time (near 400 min) when gas hourly space velocity was 8000 h^-1. Then, characterizations of XRD, BET, NH₃-TPD, FTIR, and XPS analyzed basic properties of Fe-FA and revealed reasons for the excellent adsorption performance. In general, the excellent adsorption performance of Fe-FA for H₂S is mainly due to the high content of iron species (almost 50%) and suitable mesoporous structure in the Fe-FA.