Oxidation absorption of hydrogen sulfide from gas stream using vacuum ultraviolet/H2O2/urea wet scrubbing system

Hydrogen sulfide has serious harm to human body and equipment. Advanced oxidation technology shows excellent development prospect for hydrogen sulfide (H2S) removal due to strong oxidation ability and green process. This article proposed a novel separation process for H2S from gas stream using vacuum ultraviolet (VUV)/H2O2/urea wet scrubbing system in a VUV-spraying scrubber, and studied the effectiveness of H2S removal and removal pathways using VUV/H2O2/urea wet scrubbing system. Results indicated that the highest H2S removal efficiency was up to 98.2 % under optimal experimental conditions. Increasing UV-light intensity and solution pH improved the H2S removal efficiency. Increasing fluegas flow rate and H2S concentration decreased the H2S removal efficiency. The increase of H2O2 concentration, reaction temperature, liquid-gas ratio or urea concentration first increased and then reducedthe H2S removal efficiency. H2S was removed by five pathways such as ionization, urea absorption, H2O2 oxidation, photolysis and center dot OH oxidation. Photolysis and center dot OH oxidation were the two major pathways forthe H2S removal. (c) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.