Synthesis of mercury sorbent including metal oxides with layered carbonates material

•Mercury sorbents of M–Al–CO3 (M = Mg2+, Zn2+, Cu2+, and Mn2+ ions) were prepared.•Sorption Hg was tested at 30–400 °C by hydrothermal conditions and fixed-bed reactor.•Mn/Al predominated the materials with embodiment of Hg compositions that were double that of MnO.•Elemental mercury sorption on Mn/Al sorbents also exhibited a maximum slope at 300 °C.

Mercury sorbents M–Al–CO3 were synthesized by coprecipitating M2+ and Al3+ in an alkaline NaOH/Na2CO3 solution, where M2+ corresponds to Mg2+, 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 °C and in a fixed-bed reactor at 100–400 °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 °C for the Mn/Al sorbent. These findings demonstrate the potential of these synthetic sorbents under medium to high temperature conditions.