Adsorption and catalytic oxidation of Hg0  by NID(novel integrated desulfurization) ash and CFB-FGD(circulating fluidized bed flue gas desulfurization) ash were studied by exposing the adsorbent samples to a simulated flue gas stream in a fixed-bed reactor.The results showed that mercury captured on the surface of desulfurization ash was in Hg2+ form.Higher levels of mercury oxidation were associated with higher levels of mercury capture.Generally

higher levels of mercury oxidation and adsorption rates were achieved by exposing the adsorbent samples in the combination of any two components of Cl2

HCl

NO2  than in a single component.Mercury oxidation and capture rates of NID ash were higher than those of CFB-FGD ash in the same condition.Unburnt carbon and Fe2O3  in desulfurization ash played important roles in mercury adsorption and catalytic oxidation.Mercury oxidation and capture rates increased and then decreased with rising temperature due to the joint action of mass transfer and reaction rate.