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Sulfur dioxide (SO2) and trace elements are pollutants derived from coal combustion. This study focuses on the simultaneous removal of S02 and trace arsenic oxide (As2O3) from flue gas by calcium oxide (CaO) adsorption in the moderate temperature range. Experiments have been performed on a thermogravimetric analyzer (TGA). The interaction mechanism between As2O3 and CaO is studied via XRD detection. Calcium arsenate [Ca3(AsO4)2] is found to be the reaction product in the range of 600-1000 degrees C. The ability of CaO to absorb As2O3 increases with the increasing temperature over the range of 400-1000 degrees C. Through kinetics analysis, it has been found that the rate constant of arsenate reaction is much higher than that of sulfate reaction. SO2 presence does not affect the trace arsenic capture either in the initial reaction stage when CaO conversion is relatively low or in the later stage when CaO conversion is very high. The product of sulfate reaction, CaS04, is proven to be able to absorb As2O3. The coexisting CO2 does not weaken the trace arsenic capture either.

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CuCl 2 -impregnated sorbents were employed to remove elemental mercury from flue gas. Three carriers including neutral Al 2 O 3 , artificial zeolite, and activated carbon have been investigated in this research. The performances of these prepared sorbents have been tested in a bench-scale fixed-bed reactor under different simulated flue gas atmospheres and temperatures (333−573 K). CuCl 2 -impregnated activated carbon showed the best adsorption ability. However, CuCl 2 -impregnated neutral Al 2 O 3 and zeolite have demonstrated an adsorption rate similar to that of CuCl 2 -impregnated activated carbon in the early stage of the tests (5 min), and they achieved relatively high mercury oxidation efficiencies. These non-carbon sorbents could remarkably enhance the technoeconomical properties of mercury removal in coal-fired power plants and have great potentials in industrial application. The appropriate mercury capture temperature for these sorbents is 333−473 K. The possible mechanisms of elemental mercury oxidation have been discussed.