ONLINE MEASUREMENT OF MERCURY IN SIMULATED FLUE-GAS

Total and elemental mercury (Hg) in simulated flue gas was measured on-line by. commercial Semtech(R) Hg analyzer. This instrument is based on Zeeman modulated Atomic Absorption Spectrometry. Both a wet chemical solution and a dry physical pyrolysis converter were applied to reduce the HB(II) in the gas before leading it to the detector. Results show that the Semtech(R) analyzer is suitable fcr measuring elemental Hg even in the presence of 2500 ppm SO2 and 500 ppm HCl. Fa the measurement of Hg(II), the wet method is suitable only at SO2 concentrations <50 ppm. The dry thermal converter filled with crushed quartz chips together with a small amount of soda lime converts Hg(II) quantitatively at laboratory scale. ?his result is promising, since the trace gases delivered to the system such as SO2, and HCl are similar to those produced in coal burning and waste incineration processes. The limiting factor for such a converter is its comparatively short Life time of performance, about 20 hours.