Removal of Mercury Using Novel Lamella Carbonate Sorbent at Elevated Temperature Conditions

Abstract

Carbonaceous fuel combustion has increased such that approximately 80% of current global Hg emissions originate from anthropogenic sources, particularly from coal‐fired plants and incinerators. Accordingly, the development of effective Hg scrubbing methods that enable cleaner industrial processes is of great significance to human health. Because of the weak physical adsorption of Hg at ambient temperatures, numerous sorbents are required for its removal via processes such as electrostatic precipitation, selective catalytic reduction, flue gas desulfurization, and activated carbon injection. Alternatively, capturing Hg at elevated temperatures has numerous advantages such as high capacity and the avoidance of the diffusion of Hg species throughout the process. Herein, we report the preparation of a novel sorbent with a layered structure, (Mg3‐x, Mx)‐Al‐CO3, via the coprecipitation of Mg2+, M2+, and Al3+ in an alkaline solution of NaOH/Na2CO3, where M2+ = Cu2+ or Zn2+. In a fixed‐bed reactor, the Hg removal rate R notably increased at elevated temperatures (200‐300 °C) and was enhanced by a factor of 10 via the incorporation of M2+ in Mg‐Al‐CO3. These results demonstrate the potential of such synthetic Hg sorbents under medium‐high temperature conditions.