Volatility of Cu, Ni, Cr, Co, Pb, and As in Fluidised-Bed Combustion Chamber in Relation to Their Modes of Occurrence in Coal

Modes of occurrence of Pb, As, Cr, Co, Cu, and Ni in bituminous coal and lignite were determined by means of sequential extraction using NH4OAc, HCl, HF and HNO3 extraction solutions. Elemental affinities obtained were then evaluated in relation to volatility of these elements during the combustion of these coals in two circulating fluidised-bed power stations. It was found out that higher percentage of the elements bound in silicates brought about lower volatility, while higher elemental proportion with monosulphides association (or bound as exchangeable ion) resulted in higher volatility. The only exception was the behavior of arsenic, whose volatility depended on amount of limestone added during the combustion process (as desulphurisation additive) rather than to its association in coal.

• L. Bartoňová
• Z. Klika

• Coal combustion
• sequential extraction
• trace elements
• volatility.

[1] M. Xu, R. Yan, Ch. Zheng, Y. Quiao, J. Han, Ch. Sheng, "Status of trace
element emission in a coal combustion process: a review," Fuel
Processing Technology, vol. 85, pp. 215-237, 2003.
[2] R.B. Finkelman, "Determination of trace element sites in the
Waynesburg coal by SEM analysis of accessory minerals," Scanning
Electron Microscopy, vol. 1, pp. 143-148, 1978.
[3] C.A. Booth, D.A. Spears, P. Krause, A.G. Cox, "The determination of
low level trace elements in coals by laser ablation - inductively coupled
plasma - mass spectrometry (LA - ICP - MS)," Fuel, vol. 78, pp. 1665-
1670, 1999.
[4] Z. Klika, I. Kolomazník, "New concept for the calculation of the trace
element affinity in coal," Fuel, vol. 79, pp. 659-670, 2000.
[5] Z. Klika, Z. Weiss, V. Roubíček, "Calculation of element distribution
between inorganic and organic parts of coal," Fuel, vol. 76, pp. 1537-
1544, 1997.
[6] R.M. Davidson, "Modes of occurrence of trace elements in coal. Results
from an international collaborative programme," London: IEA Coal
Research, 2000, 36 p. ISBN 92-9029-346-2.
[7] R.B. Finkelman, C.A. Palmer, M.R. Krasnow, P.J. Aruscavage, G.A.
Sellers and F.T. Dulong, "Combustion and leaching behavior of
elements in the Argonne premium coal samples," Energy and Fuels, vol.
4, pp. 755-766, 1990.
[8] C.A. Palmer, P.C. Lyons, "Chemistry and origin of minor and trace
elements in selected vitrinite concentrates from bituminous and
anthracitic coals," International Journal of Coal Geology, vol. 16, pp.
189-192, 1990.
[9] L. Bartoňov├í, Z. Klika, "Sequential Extraction of Brown Coals and
Unburned Carbons from Small Combustion Units," Acta Universitatis
Carolinae Environmentalica, vol. 19, pp. 21-32, 2005.
[10] D.J. Swaine, "Trace elements in coal," London: Butterworths, 1990, 278
p. ISBN 0-408-03309-6.
[11] Z. Klika, L. Bartoňov├í, D.A. Spears, "Effect of boiler output on trace
element partitioning during coal combustion in two fluidised-bed power
stations," Fuel, vol. 80, pp. 907-917, 2001.
[12] L. Bartoňov├í, Z. Klika, D.A. Spears, "Characterization of unburned
carbon from ash after bituminous coal and lignite combustion in CFBs,"
Fuel, vol. 86, pp. 455-463, 2007.