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 chemica l solution and a dry physical pyrolysis converter were applied to redu ce the HB(II) in the gas before leading it to the detector. Results sh ow 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 measurem ent of Hg(II), the wet method is suitable only at SO2 concentrations < 50 ppm. The dry thermal converter filled with crushed quartz chips tog ether with a small amount of soda lime converts Hg(II) quantitatively at laboratory scale. ?his result is promising, since the trace gases d elivered to the system such as SO2, and HCl are similar to those produ ced in coal burning and waste incineration processes. The limiting fac tor for such a converter is its comparatively short Life time of perfo rmance, about 20 hours.