Potential of iron-based composites derived from sucrose foam for mercury removal and safe recovery

Abstract

Although various methods for removal of elemental mercury from gas streams have been proposed, the control of mercury emissions to the environment from anthropogenic sources, mainly coal-fired power plants, remains unresolved in many countries worldwide. Meanwhile, the Minamata Convention and the IED of the European Commission continue to impose restrictions for its control and mitigation. In this work, a new material based on a sucrose foam impregnated with iron oxide nanoparticles has been developed for the adsorption of elemental mercury from flue gases allowing the regeneration of the material and the recovery of elemental mercury. Of the different iron oxides supported on the sucrose foam, αFe2O3 nanoneedles were found to be the most efficient in capturing mercury through a Mars-Maessen mechanism and the forming of HgO. The adsorbents developed proved to be effective in the presence of SO2 and H2O, with the O2 present in the gas playing a key role in the regeneration of the material. From the results found sucrose foam-based αFe2O3 composite could be an attractive alternative to traditional non-regenerable activated carbons, reducing costs and being environmentally sustainable.