Dynamic Evaluation of H₂S Adsorption Performance by Using Mining Waste and LaNi₅ in Combination

Abstract

As the demand for green hydrogen with carbon neutrality increases, this research has focused on hydrogen production via the pyrolysis of biomass resources. Hydrogen sulfide (H₂S) is an impurity produced during this process. This pollutant necessitates desulfurization since H₂S can react with the platinum catalyst in fuel cells, leading to a significant voltage reduction. Our previous studies explored the possibility of using neutralized sediment (NS)—a mining waste product—as an alternative to metal oxides for desulfurization because of its similar effectiveness and potential for reduced environmental impact. We also considered the use of LaNi₅—a hydrogen storage alloy—which can adsorb and release hydrogen and also remove H2S through the reaction of Ni with S. Initially, we discovered that hydrogen gas flow decreases the H₂S adsorption capacity of NS due to hydrogen attaching to the NS surface. Subsequently, we examined the performance of a combined NS and LaNi5 adsorbent for the complete removal of H₂S, identifying an effective temperature range above 160 °C. Additionally, our results suggested a synergistic effect on the H₂S adsorption mechanism when using NS and LaNi₅ together.