Design of A Multipollutant Sorbent for Coal Gasification

In the United States, annual coal consumption is projected to increase from 22.9 x 10^15 Btu in 2005 to 34.1x10^5 Btu in 2030 (Energy Information Administration, 2007). Increasing coal consumption leads to an increase in the release of pollutants such as NOx, SOx, CO2, and trace elements (mercury, arsenic and selenium) into the environment. This research aims to design a multi-pollutant sorbent to remove Hg, As, and Se from the high temperature environment of coal gasification.

The adsorption energetics of various Hg species (Hg, HgH, HgS), As species (As2, AsS, AsH, AsH3, As), and Se species (Se, H2Se, HSe, SeS) typically found under gasification conditions were examined with dimers of Pd2, Au2, Pt2, and V2 using density functional theory and relativistic effective core potentials for the heavier atoms. The effectiveness of each metal dimer for the adsorption of multiple flue gas components has been evaluated. Overall, this study provides recommendations for the use of Pd2, Au2, Pt2, and V2 as potential catalyst materials for the adsorption of Hg, As, and Se species from flue gases.