Removing and recovering gas-phase elemental mercury by CuxCo3−xO4 (0.75 ⩽ x ⩽ 2.25) in the presence of sulphur compounds

The Hg0 oxidation ability and reusability of CuxCo3−xO4 were investigated in an attempt to improve SO2 anti-poisoning ability of metal oxide and produce more economic and effective sorbents for the control of Hg0 emission from combustion processes. The influence of copper content on CuxCo3−xO4’s (0.75 ⩽ x ⩽ 2.25) oxidation ability of Hg0 in the presence of SO2 was investigated. According to the X-ray diffraction, Brunauer–Emmett–Teller (BET) and mass balance analysis on mercury, we found that Cu1.5Co1.5O4 showed the highest SBET and best Hg0 oxidation ability. With continuous increase of x from 0.75 to 2.25, CuxCo3−xO4’s SO2 anti-poisoning ability increased. The analysis results of the X-ray photoelectron spectroscopy manifested that the adsorptive mercury species on spent Cu1.5Co1.5O4 was HgO. The spent Cu1.5Co1.5O4 could be regenerated by thermal decomposition at 673 K and regenerated Cu1.5Co1.5O4 showed higher Hg0 oxidation ability due to Hg-doping. Regenerated enrichment Hg0 was collected using activated carbon at an ambient temperature to eliminate the secondary pollution.