ISSN:
1573-2932
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
Notes:
Abstract The combustion of coal in power plants generates solids (e.g., fly ash, bottom ash) and flue gas (e.g., SO x , CO2). New Clean Air Act mandated reduction of SO x emissions from coal burning power plants. As a result, a variety of Clean Coal Technologies (CCT) are implemented to comply with these amendments. However, most of the CCT processes transfer environmentally sensitive elements (e.g., As, Cd, Pb, Se) from flue gas to CCT ash. The objective of this study was to determine the effect of a pressurized CO2 treatment on the chemistry of CCT ash. Three CCT ash samples, produced from lime injection, atmospheric fluidized bed combustion, and sodium carbonate injection processes were reacted under different CO2 pressure treatment conditions. Treated and untreated samples were subjected to various experiments including, X-ray diffraction (XRD) analysis, calcium carbonate solubility studies, and trace element extraction studies. Factors influencing the efficiency of a CO2 treatment for CCT ash samples include combustion process, moisture, CO2 concentration, and pressure. The CO2 pressure treatment resulted in the precipitation of calcite in CCT ash samples, and thus lowered the pH and the concentration of extractable trace elements (e.g., Cd, Pb, Cr, As, Se). Furthermore, we found that CO2 pressure treatment was more effective for lime injection and atmospheric fluidized bed combustion processed samples than for sodium carbonate injection processed samples.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00475350
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