Speciation of mercury in coal and sludge combustion flue gases

Because mercury has varying reactivity depending on its speciation, understanding mercury speciation is important in predicting the fates of mercury in combustion flue gases and formulating effective strategy of its control. Mercury speciation was determined in the combustion flue gases of coal and sludge. The extent of mercury oxidation was investigated with respect to changes in fuel properties and combustion conditions such as temperature and concentrations of oxygen (O2), carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx) and sulfur dioxide (SO2). Mercury content in the sludge samples was found to be much higher than that in the coal sample. O2 and CO2 concentrations were found to be closely related to Hg oxidation in the flue gases.