Surfactant-modified biosolid-derived materials as efficient H2S removal media: Synergistic effects of carbon phase properties and inorganic phase chemistry on reactive adsorption

A new H2S reactive adsorbent was prepared from a biosolid by the addition of pluronic surfactant F127 prior to a simple pyrolysis at 950 degrees C at two heating regimes. The materials were extensively characterized and tested as H2S removal media from air. The results show an over 250% increase in the H2S removal efficiency compared to the adsorbent obtained without the surfactant addition. Hydrogen sulfide was converted mainly to elemental sulfur. While the surfactant increased the carbon content and volume of mesopores, slow pyrolysis additionally contributed to the development of micropores, increased a carbon structural order, and resulted in an enhanced dispersion of catalytic centers (Ca and Fe oxides) on the surface. It also increased the amount of nitrogen in pyridinic configurations. All of these facilitated electron transfers, thus promoting oxidation reactions, and provided the sites increasing H2S interactions with the surface and also those acting as a storage system for elemental sulfur.