Removal of H2S from gas stream using combined plasma photolysis technique at atmospheric pressure

► A combined plasma with photolysis reactor was constructed to decompose H2S. ► The influence of operation parameters on removal efficiency was investigated. ► The new technique is safe because the main products were H2O and SO42-. In this paper, H2S in gas stream was successfully decomposed at atmospheric pressure by dielectric barrier discharge plasma and VUV–UV radiation from a combined plasma photolysis reactor (CDBD). In comparison with DBD, CDBD enhanced H2S removal efficiency significantly at the same applied voltage, inlet H2S concentration and gas residence time. H2S removal efficiency was determined as a function of Kr pressure, applied voltage, inlet H2S concentration, and gas residence time. H2S removal efficiency could reach as high as 93% at inlet H2S concentration of 27.1mgm−3, residence time of 0.4s, and applied voltage of 7.5kV. The main products were discerned as H2O and SO42- based on FTIR and IC analysis.