A pilot-scale TiO2 photocatalytic system for removing gas-phase elemental mercury at Hg-emitting facilities

A pilot-scale TiO2 photocatalytic system using common household fluorescent lamps was tested at a real combustion facility for its ability to control Hg0 emissions. An Hg0 removal efficiency of greater than 90% was achieved under optimum conditions. The photocatalytic reaction units connected in series were more efficient than those connected in parallel. Acid components of the flue gas, such as NO and H2O, exhibited significant negative effects on the Hg0 removal efficiency. There was no difference in Hg0 removal efficiency between the systems employing mono-wavelength and tri-wavelength fluorescent lamps, and the efficiency was enhanced by increasing the amount of irradiation.