Hydrogen sulfide removal technology: A focused review on adsorption and catalytic oxidation

Abstract

The principal technologies for H2S removal are reviewed herein. Two technologies in particular, adsorption and catalytic oxidation, are considered as promising for desulfurization in terms of process simplicity, H2S removal performance, and operational cost. Nanoporous materials such as activated carbons, zeolites, mesoporous silicas, and metal organic frameworks are extensively used as sorbents because their porous characteristics are suitable for efficient diffusion and capture of H2S. To improve the H2S adsorption performance, these materials are frequently modified with functional groups or doped with various metal oxides. For example, representative metal oxide-based catalysts (e.g., vanadium, magnesium, and iron oxides) have been investigated for the selective oxidation of H2S to elemental sulfur. In this context, the dispersion of active metals onto supports, or the addition of modifying metals, are reasonable strategies for inhibiting catalyst deactivation and enhancing catalytic activity. Emerging studies based on the combination of adsorption and catalytic oxidation have introduced the syntheses of dual-function materials, such as metal nanoparticle-dispersed or metal-free porous carbons. In conclusion, comprehensive research into catalyst synthesis and performance evaluation must continue in order to develop the most promising technology for H2S removal.