A Study of Mercury Removal in FBC Systems Fired with High Chlorine Coals

Abstract

The objective of this project is to study the reduction, at a low monetary cost, of mercury emissions from coal fired combustors by using HCl to convert elemental mercury to oxidized mercury species. The HCl atmosphere needed for the oxidation of elemental mercury is provided by the combustion of high chlorine coal in a utility boiler system at relatively low temperatures (500-600°C). By oxidizing elemental mercury inside the fluidized bed combustion (FBC) system, total mercury emissions can be reduced with high efficiency and low cost while maintaining low emissions of other pollutants. The results indicate that using high chlorine coal in an FBC system converted more than 99% of elemental mercury to an oxidized state — mainly HgCl₂.

Keywords:

• Mercury
• Chlorine
• Combustion