Synthesis of mercury sorbent including metal oxides with layered carbonates material

Mercury sorbents M-Al-CO3 were synthesized by coprecipitating M2+ and Al3+ in an alkaline NaOH/Na2CO3 solution, where M2+ corresponds to me, Zn2+, Cu2+, and Mn2+ ions. The formation of a layered double hydroxide structure significantly enhanced the surface area of the synthetic materials. Mercury removal tests were conducted under hydrothermal conditions between 30 and 250 degrees C and in a fixed-bed reactor at 100-400 degrees C. Energy-dispersive X-ray spectroscopy clearly indicated that the principal elements were embedded in the spent sorbents along with Hg. This analysis showed that Mn/Al predominated the materials with compositions that were double that of MnO, followed by Zn, Mg, and Cu. The mercury sorption curve exhibited a maximum slope at 300 degrees C for the Mn/Al sorbent. These findings demonstrate the potential of these synthetic sorbents under medium to high temperature conditions. (C) 2015 Elsevier B.V. All rights reserved.