Dioxin emissions from coal combustion in domestic stove: Formation in the chimney and coal chlorine content influence

• Published in: Thermal science 2015-01, Vol.19 (1), p.295-304
• Main Authors: Paradiz, Bostjan, Dilara, Panagiota, Umlauf, Gunther, Bajsic, Ivan, Butala, Vincenc
• Format: Article
• Language: English
• Subjects: Chimneys; Chlorine; Coal; Combustion; Dioxins; Domestic; Flue gas; Flue gases; Formations; Gas temperature; Household wastes; Incinerators; Stoves
• ISSN: 0354-9836; 2334-7163
• DOI: 10.2298/TSCI140113079P

Combustion experiments conducted in domestic stove burning hard coal demonstrated a predominant influence of the coal chlorine content on the PCDD/F emissions, together with a pronounced effect of the flue gas temperature. PCDD/F concentrations of over 100 ng TEQ/m3, three orders of magnitude higher than in a modern waste incinerator, were measured in the flue gases of a domestic stove when combusting high chlorine coal (0.31 %). The PCDD/F concentrations in the flue gases dropped below 0,5 ng TEQ/m3, when low chlorine coal (0.07 %) was used. When low chlorine coal was impregnated with NaCl to obtain 0.38 % chlorine content, the emission of the PCDD/Fs increased by two orders of magnitude. Pronounced nonlinearity of the PCDD/F concentrations related to chlorine content in the coal was observed. The combustion of the high chlorine coal yielded PCDD/F concentrations in flue gases one order of magnitude lower in a fan cooled chimney when compared to an insulated one, thus indicating formation in the chimney. The influence of flue gas temperature on the PCDD/F emissions was less pronounced when burning low chlorine coal. The predominant pathway of the PCDD/F emissions is via flue gases, 99 % of the TEQ in the case of the high chlorine coal for insulated chimney.