title: Mercury Removal by Magnetic Biochar Derived from Simultaneous Activation and Magnetization of Sawdust.
abstract: Novel magnetic biochars (MBC) were prepared by one-step pyrolysis of FeCl3-laden biomass and employed for Hg0removal in simulated combustion flue gas. The sample characterization indicated that highly dispersed Fe3O4particles could be deposited on the MBC surface. Both enhanced surface area and excellent magnetization property were obtained. With the activation of FeCl3, more oxygen-rich functional groups were formed on the MBC, especially the C═O group. The MBC exhibited far greater Hg0removal performance compared to the nonmagnetic biochar (NMBC) under N2+ 4% O2atmosphere in a wide reaction temperature window (120-250 °C). The optimal pyrolysis temperature for the preparation of MBC is 600 °C, and the best FeCl3/biomass impregnation mass ratio is 1.5 g/g. At the optimal temperature (120 °C), the Fe1.5MBC600was superior in both Hg0adsorption capacity and adsorption rate to a commercial brominated activated carbon (Br-AC) used for mercury removal in power plants. The mechanism of Hg0removal was proposed, and there are two types of active adsorption/oxidation sites for Hg0: Fe3O4and oxygen-rich functional groups. The role of Fe3O4in Hg0removal was attributed to the Fe3+(t) coordination and lattice oxygen. The C═O group could act as act as electron acceptors, facilitating the electron transfer for Hg0oxidation.
authors.affiliation: State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Yongchun
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Siming
authors.initials: S
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Binbin
authors.initials: B
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Junying
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Chuguang
authors.initials: C
authors.lastname: Zheng
mesh_terms: D000327:Adsorption; D002606:Charcoal; D059346:Magnets; D008628:Mercury; D010084:Oxidation-Reduction; D011210:Power Plants; D013696:Temperature
chemical_list: D002606:Charcoal; D008628:Mercury