Mercury removal from flue gas by magnetic iron-copper oxide modified porous char derived from biomass materials

Abstract

In this work, a magnetic iron-copper oxide modified porous char derived from biomass materials was prepared by microwave activation and ultrasonic-assisted impregnation method to remove Hg0 from flue gas. The effects of operating parameters and flue gas components on Hg0 removal performance as well as physicochemical properties of samples were studied. The reaction mechanism and the regeneration performance of samples were also investigated. The experimental results display that the biomass-based porous char derived from microwave and steam activation exhibits a larger pore volume, higher surface area and well-developed pore structure. The ultrasonic treatment promotes the dispersion of active components on the surface of samples. The CuFe0.3/WSWU10(500) sample exhibits good Hg0 removal performance, and about 90.58% of Hg0 is captured from flue gas at 130 °C. Increasing SO2 concentration inhibits Hg0 removal. The presence of O2 and NO promotes the removal of Hg0. Low concentration of water vapor (>4%) improves Hg0 removal performance, while excessive water vapor plays an opposite role. The presence of copper/iron active components, chemisorbed oxygen and lattice oxygen over the surface of adsorbent is conducive to the removal of Hg0. The modified sample exhibits a good regeneration performance.