Thermal desorption and speciation of mercury in fly ash

FUEL 138

Junru Li1, Yang Yuan1, and M. Mercedes Maroto-Valer, mercedes.maroto-valer@nottingham.ac.uk2. (1) School of Chemical, Environmental and Mining Engineering, University of Nottingham, (2) School of Chemical, Environmental and Mining Engineering, University of Nottingham, Coates Building, University Park, NG7 2RD, United Kingdom
Mercury emitted from coal-fired utilities mainly includes gaseous element form (Hg0), oxidised mercury (Hg2+) and particulate bound mercury (Hgp). Oxidized mercury is water-soluble and reacts more readily with fly ash and sorbents, while elemental mercury is more difficult to control. A better understanding of the process that governs mercury oxidation in flue gas is needed as this will facilitate the development and optimization of mercury control technologies. The work thus far has focused on understanding mercury oxidation on the surface of fly ash. A series of mercury model compounds have been characterized by using a PSA thermal dissociation rig coupled with an AFS analyser to identify the thermally induced behaviour of mercury species. The studies have shown that different model compounds have characteristic temperatures and can be separated. After the completion of the model compounds studies, different fly ashes will be tested to ascertain the mercury species present in each fly ash. Theoretical modeling studies on mercury oxidation will also be reported using the Gaussian 03W modeling program.
 

Mercury and Trace Metal Transformations: Modeling
8:25 AM-11:35 AM, Tuesday, August 21, 2007 Boston Park Plaza -- Chartes River Room, Oral

Division of Fuel Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007