Photocatalytic removal of elemental mercury via Ce-doped TiO 2 catalyst coupling with a novel optical fiber monolith reactor:
Abstract
Reduction of mercury emission from coal combustion is a serious task for public health and environmental societies. Herein, Ce-doped TiO
2 (Ce/TiO
2) catalyst coupling with a novel optical fiber monolith reactor was applied to efficiently remove elemental mercury (Hg
0) from coal-fired flue gas. Under the optimal operation condition (i.e., 1.5 mW/cm
2 UV light, 90 °C), above 95% of Hg
0 removal efficiency was attained over the optical fiber monolith reactor coating with 3.40 g/m
2 Ce/TiO
2 catalyst. The effects of flue gas compositions on Hg
0 removal performance were clarified systematically. Gaseous O
2 replenished the surface oxygen, hence maintaining the production of free radicals and promoting the removal of Hg
0. SO
2, HCl, and NO inhibited Hg
0 removal in the absence of O
2 due to the competitive adsorption and consumption of free radicals. However, SO
2 and HCl significantly enhanced Hg
0 removal with the participation of O
2, while NO exhibited obviously inhibitory effect even with the assistance of O
2. H
2O also decreased the Hg
0 oxidation capacity owing to the competitive adsorption and reduction of HgO. The optical fiber monolith reactor exhibited much superior Hg
0 removal capacity than the powder reactor. Utilization of Ce/TiO
2 catalyst coupling with an optical fiber monolith reactor provides a cost-effective method for removing Hg
0 from coal-fired flue gas.
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου