(60h) Effects of Preparation Parameters on Simultaneous Removal of Hg(0) and NO over Modified SCR Catalyst

Elemental mercury (Hg(0)) released from coal combustion has widely been recognized as an environmentally toxic heavy metal due to its toxicity and bioaccumulation. Since oxidized mercury (Hg(2+)) is highly soluble in water and can be easily captured with a downstream wet FGD system, it is critical to reduce mercury emissions by oxidizing the elemental form.

In this study, the effects of the preparation parameters (TiO₂ supports and calcination temperatures) on the simultaneous removal of Hg(0) and NO over a modified Selective Catalytic Reduction (SCR) catalyst were investigated using a fixed-bed system in a temperature range of 300 to 400 °C under a steady-state condition. The Hg(0) oxidation and NO reduction performances significantly change with respect to different TiO₂ supports and calcination temperatures. The optimal TiO₂ support and calcination temperature have been determined to show the best performances of Hg(0) oxidation and NO reduction under typical simulated coal combustion flue gas conditions. Different characterization techniques including BET, TEM, XRD, XPS, XAFS and DRIFTS were used to elucidate the mechanisms responsible for the performance differences. The detailed experimental and characterization results will be presented.