Optimization of Sulfur Impregnation Protocol for Fixed-Bed Application of Activated Carbon-Based Sorbents for Gas-Phase Mercury Removal

Abstract

Novel sulfur-impregnated activated carbons for vapor phase mercury uptake (BPL-S series) were designed and developed in this study. Temperature and the initial sulfur to carbon ratio (SCR) during impregnation were the two control parameters for the impregnation procedure. By adjusting these two variables, a series of sulfur-impregnated carbons was created. These new materials together with commercially available sulfur-impregnated activated carbon (HGR) and coal samples were evaluated for the uptake of vapor phase elemental mercury using nitrogen as a carrier gas. The results showed that carbons impregnated with sulfur at high temperature exhibited the highest efficiency for mercury removal. As the impregna tion temperature decreased, the performance of the carbons deteriorated. When SCR was varied from 4:1 to 1:2, the sulfur content decreased only slightly, which resulted in a small decrease in mercury uptake capacity. Therefore, the impregnation temperature is the most important factor influencing the e...