Role of fly ash in heavy metal removal from flue gas. Final report, September 1, 1994--February 29, 1996
The work is mainly focused towards investigating the sorption phenomena of a representative chalcophile, arsenic (As) species, on fly ashes at temperatures representative of the upper-furnace region (850 -1200{degrees}C) and the economizer section (375-600{degrees}C). Arsenic is chosen because it is a highly toxic chalcophile and shows some affinity for fly ash but is also emitted from the stack as vapor and aerosol particles. Based on the preliminary thermodynamic analyses it was determined that under the temperature ranges of interest (400- 600{degrees}C and 800-1000{degrees}C) arsenic trioxide (As{sub 2}O{sub 3}) is the main arsenic species in the flue gas environment. The two temperature zones have been chosen because most of the dry-sorbent injection technologies are being developed for application in these two regions. Also various fly ash samples from different sources are being studied because their chemical composition and subsequently their chemical sorption characteristics would show a great deal of variation depending on their source. Studies were also conducted with calcium hydroxide as the chosen representative dry sorbent. This served as comparative studies between fly ash and dry sorbents. This will enable us to predict the behavior of arsenic when exposed to both fly ash and sorbent which is the case under actual boiler conditions. Experimental results show that Ca(OH){sub 2} captures significant amounts of arsenic species. To gain further insight into the capturing mechanism of calcium hydroxide experiments were performed at various temperatures and exposure times.
- Research Organization:
- The Ohio State Univ., Columbus, OH (United States)
- Sponsoring Organization:
- Ohio State Government, Columbus, OH (United States)
- OSTI ID:
- 419442
- Report Number(s):
- OCDO-97001485; ON: TI97001485
- Resource Relation:
- Other Information: PBD: Oct 1996
- Country of Publication:
- United States
- Language:
- English
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