Separation of hydrogen sulfide from gas phase using Ce3+/Mn2+-enhanced fenton-like oxidation system

Abstract

A novel separation process of hydrogen sulfide from gas phase using Ce3+/Mn2+-enhanced Fe3+/H2O2 oxidation systems (i.e., Ce3+/Mn2+-enhanced Fenton-like oxidation systems) in a bubbling stirred reactor was developed. Experiments were conducted to study the effects of several influencing factors (Fe3+ and H2O2 concentrations, concentrations of Ce3+/Mn2+, solution temperature, H2S inlet concentration, gas flow rate, stirring rate and initial solution pH) on H2S removal. Ion chromatography, high performance liquid chromatography, flue gas analyzer and electron spin resonance capture technology were used to measure the reaction products and free radicals in H2S removal process. Mechanism and routes of H2S removal were also proposed preliminarily. The results reveal that addition of Ce3+/Mn2+ effectively enhances H2S removal in Fenton-like oxidation system. The enhancement effects are caused by production of more OH that are produced from synergistic effect between Fe3+ and Ce3+/Mn2+ in the Fenton-like oxidation systems. H2S removal efficiency was increased by increasing Fe3+ concentration and concentrations of Ce3+/Mn2+, and decreased by increasing H2S inlet concentration and gas flow rate. Increasing H2O2 concentration, solution temperature, stirring rate and initial solution pH show double impact on H2S removal. H2S is mainly removed by oxidation of OH (it is the main reaction route of H2S removal). The new removal technology can provide new an option for removal of gaseous hydrogen sulfide.