Chemical Looping Selective Oxidation of H₂S using V₂O₅ Impregnated over Different Supports as Oxygen Carriers

Abstract

Abstract Chemical looping concept is proposed to improve the efficiency of selective oxidation of H 2 S into elemental sulfur. V 2 O 5 as an active oxygen carrier, is impregnated on different supports and exposed cyclically to reductant (H 2 S) and to oxidant (O 2 ). Among all, TiO 2 and SiO 2 proved as better supports for V 2 O 5 as they provided more formation of elemental sulfur than undesired SO 2 in the reductant step. Results indicate that the support can either directly react and provide oxygen to the process like for CeO 2 or indirectly affect the properties of the active phase, leading either into the improvement, as for TiO 2 and SiO 2 , or worsening, as in case of Al 2 O 3 and ZrO 2 . Oxygen carriers with partially reduced species, i. e., the combination of V 5+ and V 4+ , show better performances than carriers containing mostly highly oxidized V 5+ species. Interaction between the active phase and support plays a vital role for the controls of the formation of these partially reduced species.