(33f) Chemisorption of Elemental Mercury Onto CuCl2-Impregnated Activated Carbon Sorbent

Elemental mercury (Hg(0)) is an environmentally toxic heavy metal that is released during the combustion of coal in power plants. It is imperative that Hg(0) be removed due to its toxicity and bioaccumulation. Since oxidized mercury (Hg(2+)) is highly soluble in water and can be easily adsorbed, it is normal practice to remove mercury by oxidizing the elemental form. In our studies, CuCl₂-impregnated activated carbon (AC) sorbent has shown great potential to oxidize Hg(0) without losing any chlorine species in a typical flue gas temperature window while AC sorbent adsorbs the oxidized form. The CuCl₂/AC sorbent with three different CuCl₂ loadings of 0.2, 0.6, and 1%(wt) was prepared using wetness incipient method. The breakthrough curves for Hg(0) and Hg(2+) were determined as a function of CuCl₂ loading. A rigorous mathematical model was developed to describe the oxidation of Hg(0) with CuCl₂ and the subsequent adsorption of Hg(2+) based on our previous detailed kinetic studies of the oxidation and adsorption. In this presentation, the kinetic model results for Hg(0) oxidation reaction followed by subsequent Hg(2+) adsorption will be compared with experimental results for the prediction of Hg(0) chemisorption onto CuCl₂/AC sorbent.