CARBONACEOUS MATERIALS AS DESULFURIZATION MEDIA

Activated carbon-based materials have proven to work efficiently as adsorbents of sulfur containing species such as hydrogen sulfide, sulfur dioxide, methyl mercaptans from gas phase. This is owing to their surface feature such as functional groups, ash constituents, and high volume of small pores. In the pore system, sulfur containing species are oxidized to either elemental sulfur, sulfur dioxide or dimethyldisulfide depending on the chemistry of the species to be removed. Oxygen and nitrogen containing functional groups and catalytic metals such as iron or calcium are involved in this process. Presence of water film ensures sufficient conditions for dissociation providing that the local pH of the surface is greater than pK

a

of the adsorbate. In this brief review the emphasis is placed on the role of activated carbons surfaces, either unmodified or modified in the processes of adsorption and catalytic oxidation of sulfur containing pollutants.