Factors that influence kinetic reactivity and equilibrium between elemental mercury, carbon. and flue gas components have been the focus of numerous studies. This study pertains to recent bench-scale fixed-bed tests in which activated carbon was exposed to HgCl2 in a flue gas composition typical of an unscrubbed eastern bituminous coal. Results are discussed in light of a refined binding site model based on the zigzag carbene structures recently proposed for electronic states at the edges of the carbon graphene layers. (C) 2009 Elsevier B.V. All rights reserved.