Effects of different coals on mercury distribution in a 6 kWth circulating fluidized bed under air and O2/CO2 atmosphere via experiment and thermodynamic equilibrium calculation

Mercury distribution is important to know clearly under O-2/CO2 atmosphere. Although some reports in published about mercury transform under oxy-coal combustion, different kinds of coal on the mercury distribution in a 6 kWth circulating fluidized bed under air and O-2/CO2 atmosphere via experiment and thermodynamic equilibrium calculation has been little studied. Hg2+ concentration was lower under oxy atmosphere compared to that under air atmosphere. The percentage of mercury oxidized was affected by the unburned carbon contents of fly ashes. According to thermodynamic calculation, five major products associated with mercury would be generated: Hg-0, HgO, HgS, HgCl, and HgCl2. Moreover, from 350 degrees C to 1200 degrees C, the mole percent of Hg-0 arrives its peak. The mole percent of HgO in the flue gas is decreased according to the following order: 40%O-2/60%CO2 > 30%O-2/70%CO2 > 21%O-2/79%CO2 > air. (C) 2016 Energy Institute. Published by Elsevier Ltd. All rights reserved.