|Abstract Title:||Traceable measurements of mercury species in emissions from cement production facility|
|Presenter Name:||Jože Kotnik|
|Company/Institution:||Jožef Stefan Institute|
|Session:||Special Session - Metrological Traceability for mercury analysis and speciation|
|Co-Authors:||Jože Kotnik,Igor Živković,Jan Gačnik,Tanja Ljubič Mlakar,Milena Horvat|
Abstract Information :
Within this work we tested and validated existing methods for on-line Hg monitoring from process stack emissions using the calibration methods, reference gas standards, and protocol developed during the MercOx project. A cement clinker production facility (in Anhovo, Slovenia) were used for the field tests. Samples from the stack gas were collected using different types of commercial Ohio Lumex sorbent traps. The measurements were carried out with sorbent traps for the determination of total mercury in accordance with the new CEN TS 17286 method and the US EPA 30B method and with traps for speciation. Sorbent traps were used to collect flue gas for the determination of total Hg, mercury speciation, and stable isotope ratio analysis. The results of analyses using sorbent traps were in good agreement with the results measured by CEMS. At the cement plant, three modes of operation were employed during the sampling, depending on the number of mills operating. The results showed a clear trend in concentrations of different mercury fractions that depend on the plant operation mode. Total Hg and oxidized Hg were the lowest during two-mills operation while greatest during no-mill operation of the plant. The inverse trend was observed for the elemental mercury. A cold vapor generator hyphenated to Inductively Coupled Plasma - Mass Spectrometry was used for the quantitative determination of Hg in the sorbent trap samples. The digestions of the ball-mill homogenized carbon from the carbon-trap sections of the speciation traps and from the total Hg traps was performed with the optimized procedure. In general, as high as 50 % of Hg(II) is trapped on sections of the traps, which are not normally considered as trapping sorbent for oxidized mercury (e.g. KCl); the data implies that glass wool and acid gas scrubber are more efficient trapping media compared to KCl.