Submicrometer particle formation and mercury speciation under O{sub 2}-CO{sub 2} coal combustion
- Aerosol and Air Quality Research Laboratory and Environmental Engineering Science, St. Louis, MO (United States)
The characteristics of the submicrometer mode of ash and mercury speciation on combustion of coal in an oxygen-carbon dioxide and air (conventional) system were compared. The experiments were conducted at different O{sub 2}:CO{sub 2} and O{sub 2}:N{sub 2}:CO{sub 2} mixing ratios. On replacing the nitrogen in air with carbon dioxide, the total mass of the particles in the submicrometer mode ({lt}0.5 {mu}m) of ash was smaller. Correspondingly, the geometric mean size (d{sub pg}) of the submicrometer aerosol was smaller by approximately 28%. When the O{sub 2}:CO{sub 2} ratio was increased from 1:4 to 4:4, the geometric mean size of the submicrometer mode increased from 29 to 54 nm because of a faster vaporization rate as a result of a higher coal particle temperature. An increase in the geometric mean size was observed on increasing the N{sub 2}:CO{sub 2} ratio at a fixed O{sub 2} concentration because of the same reasons. The shape of the primary particles was spherical in all the tests, indicating that a vapor to particle transformation pathway was prevalent. The ratios of elemental to oxidized mercury (approximately 4:1) were similar for O{sub 2}-CO{sub 2} and air combustion. 31 refs., 8 figs., 2 tabs.
- OSTI ID:
- 20838253
- Journal Information:
- Energy and Fuels, Vol. 20, Issue 6; Other Information: pratim-biswas@seas.wustl.edu; ISSN 0887-0624
- Country of Publication:
- United States
- Language:
- English
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