Characteristics and Regeneration Properties of Manganese Oxide Sorbent under O2 Atmosphere
The regeneration behavior of manganese oxide sorbent under O2atmosphere was investigated in a fixed bed micro-reactor under the influence of different temperatures and O2 concentrations. The change in phase of the sulfided and the regenerated sorbents was analyzed by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) techniques. MnS, Mn3O4 and MnSO4 were found in regenerated sorbent at 400 °C, which indicated that the regeneration of the sulfided sorbent was not complete, however, MnS was converted to Mn3O4, Mn2O3 and few MnSO4 at 800 °C. The manganese sulfate formed during the regeneration but decomposed to Mn2O3 at 800 °C. MnS reacts with O2 to form Mn3O4 and MnSO4, and then MnSO4 was decomposed at 800 °C. The results show that the optimum regeneration temperature and O2 concentration obtained from this experiment are 800 °C and 2.2 vol %, respectively, and the regeneration conversion ratio was about 95%.