Combined theoretical and experimental investigation of mechanisms and kinetics ofvapor-phase mercury uptake by carbonaceous surfaces

摘要

The overall goal of this research program is to gain fundamental understanding ofthe important chemistry and physics involved in mercury absorption on carbonaceous surfaces. This knowledge will then be used to optimize adsorption processes and operating conditions to maximize the uptake of mercury within the required contact time. An additional long-term benefit of this research is the basic understanding of the Hg absorption process, which may facilitate the design of new absorbents for more efficient and cost-effective removal of Hg from a variety of effluent streams. Molecular modeling of the absorption of Hg on carbonaceous surfaces will greatly increase the insight into the physics of the absorption process and combined with in situ rate measurements of mercury absorption and desorption (conventional and pulsed laser) on graphite using linear and nonlinear optical probes with real time optical resolution have the potential to provide fundamental insight into the process of mercury uptake by carbonaceous surfaces. Besides accurate assessment of key parameters influencing absorption equilibrium, fundamental understanding of the kinetics of mercury absorption, desorption, and diffusion will be developed in this study. These key physical and chemical processes postulated through molecular modeling efforts and verified by in situ measurements will be utilized to select (or develop) promising sorbents for mercury control, which will be tested under dynamic conditions using simulated flue gas.