A systematic review on the efficiency of cerium-impregnated activated carbons for the removal of gas-phase, elemental mercury from flue gas.

In the present systematic review, we aimed to collect and analyze all the relevant evidence on the efficiency of cerium-impregnated versus virgin-activated carbons (ACs) for the removal of gas-phase elemental mercury (Hg0) from the flue gas of coal-fired power plants and to assess the effect of different calcination and operational parameters on their efficiency. A total of eight relevant papers (out of 1193 hits produced by the search) met the eligibility criteria and were included in the study. Results indicated that the Hg0 adsorption capacity of cerium-impregnated ACs is significantly higher than that of virgin ACs, depending highly on the impregnation and operational parameters. It was noticed that although cerium-impregnated ACs possessed smaller surface areas and pore volumes, their Hg0 removal efficiencies were still higher than their virgin counterparts. An increased Hg0 removal efficiency was in general found by increasing the operational adsorption temperature as high as 150-170 °C. Studies also indicated that NO, SO2, and HCl have promoting impacts on the Hg0 removal efficiency of Ce-impregnated ACs, while H2O has an inhibitory effect.