Accurate sampling of PCDD/F in high temperature flue-gas using cooled sampling probes

作者：Duong Ngoc Chau Phan^*; Weidemann Eva; Lundin Lisa; Marklund Stellan; Jansson Stina

来源：Chemosphere, 2012, 88(7): 832-836.

DOI：10.1016/j.chemosphere.2012.03.090

• Polychlorinated dibenzo-p-dioxins
• Polychlorinated dibenzofurans
• Quenching
• Sub-zero cooling probe
• Waste combustion

In a laboratory-scale combustion reactor, flue-gas samples were collected at two temperatures in the post-combustion zone, 700 degrees C and 400 degrees C, using two different water-cooled sampling probes. The probes were the cooled probe described in the European Standard method EN-1948:1, referred to as the original probe, and a modified probe that contained a salt/ice mixture to assist the cooling, referred to as the subzero probe. To determine the efficiency of the cooling probes, internal temperature measurements were recorded at 5 cm intervals inside the probes. Flue-gas samples were analyzed for polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs). Samples collected at 700 degrees C using the original cooling probe showed higher concentrations of PCDD/Fs compared to samples collected using the sub-zero probe. No significant differences were observed between samples collected at 400 degrees C. The results indicated that artifact formation of PCDD/Fs readily occurs during flue-gas sampling at high temperatures if the cooling within the probe is insufficient, as found for the original probe at 700 degrees C. It was also shown that this problem could be alleviated by using probes with an enhanced cooling capacity, such as the sub-zero probe. %26lt;br%26gt;Although this may not affect samples collected for regulatory purposes in exit gases, it is of great importance for research conducted in the high-temperature region of the post-combustion zone.

• 出版日期2012-8