Study on Reactivity of HgO over Activated Carbon with HCl and SO2 in the Presence of Moisture by Temperature-Programmed Decomposition Desorption Mass Spectrometry

Abstract

Reactivities of mercury compounds over mercury sorbents with HCl and SO2 are very important to the design of a solid sorbent for mercury vapor removal from coal-derived flue gases. However, presently available data on the reactivity of mercury oxide over mercury sorbent is insufficient. This study investigated the reactivity of mercury oxide with HCl and SO2 using a temperature-programmed decomposition and desorption technique and a mass spectrometer (TPDD-mass) method. Mercury desorption from HgO over activated carbon (HgO/AC) was observed at the same temperature range as from HgO/SiO2, but the mercury desorption peak from the HgO/AC was observed at a higher temperature than from the HgO/SiO2, indicating that some of the HgO was stabilized by the AC surface. When the HgO/AC was pretreated with HCl–H2O, the formation of HgCl2 was suggested by the mass spectra of m/z = 272 and 270. The mercury desorption temperatures in the TPDD spectra were lower than those of nonpretreated samples. On the basis of the sh...