Removing and recovering gas-phase elemental mercury by Cu xCo 3−xO 4 (0.75 ⩽ x ⩽ 2.25) in the presence of sulphur compounds

Abstract

The Hg 0 oxidation ability and reusability of Cu x Co 3− x O 4 were investigated in an attempt to improve SO 2 anti-poisoning ability of metal oxide and produce more economic and effective sorbents for the control of Hg 0 emission from combustion processes. The influence of copper content on Cu x Co 3− x O 4’s (0.75 ⩽ x ⩽ 2.25) oxidation ability of Hg 0 in the presence of SO 2 was investigated. According to the X-ray diffraction, Brunauer–Emmett–Teller (BET) and mass balance analysis on mercury, we found that Cu 1.5Co 1.5O 4 showed the highest S BET and best Hg 0 oxidation ability. With continuous increase of x from 0.75 to 2.25, Cu x Co 3− x O 4’s SO 2 anti-poisoning ability increased. The analysis results of the X-ray photoelectron spectroscopy manifested that the adsorptive mercury species on spent Cu 1.5Co 1.5O 4 was HgO. The spent Cu 1.5Co 1.5O 4 could be regenerated by thermal decomposition at 673 K and regenerated Cu 1.5Co 1.5O 4 showed higher Hg 0 oxidation ability due to Hg-doping. Regenerated enrichment Hg 0 was collected using activated carbon at an ambient temperature to eliminate the secondary pollution.