Removal of hydrogen sulfide by permanganate based sorbents: Experimental investigation and reactor modeling

The removal of hydrogen sulfide from ambient air can be accomplished by porous adsorbents, which are impregnated with potassium permanganate. In this study such adsorbents were prepared by granulation on a pelletizing disk and characterized in breakthrough measurements with hydrogen sulfide. In these experiments different reaction times, pellet sizes, inlet concentrations and residence times were analyzed. To investigate the reaction process inside the pellet, microscopic analyses and REM/EDX element scans of reacted particles after different reaction times were performed. These results indicate that the reaction mainly proceeds at a rather sharp reaction front. As a first approach the shrinking core model was applied for the description of the breakthrough curves, showing already a good agreement with the experimental results. Additionally a volume reaction model was developed, which considers two consecutive reactions occurring in the whole particle volume. In contrast to the shrinking core model, the volume reaction model allows for describing the decrease of the measured position of the reaction zone in good agreement with the optical and elemental analyses of the reacted adsorbent pellets. (C) 2016 Elsevier Ltd. All rights reserved.