Improving the SO2 absorption rate of CeFeMg-based sorbent promoted with titanium promoter

Abstract

To improve the poor SO2 absorption rate of CeFeMgTi sorbent with high sulfur removal capacity and fast regeneration, a new sorbent, CeFeMgTi-sol was prepared by the modified co-precipitation method and tested in a packed bed reactor at RFCC conditions (sulfation of MgO to MgSO4 in the presence of low concentration of SO2 at 973 K, regeneration of MgSO4 to MgO and H2S in the presence of H2 at 803 K). The CeFeMgTi-sol sorbent showed excellent SO2 absorption and sulfur removal capacity (46.2 sulfur g/g absorbent×100). It was found that the SO2 absorption rates were related to the structure of the Mg and Ti and the textural properties such as surface area and pore volume. In the case of the fresh state of CeFeMgTi sorbent, CeO2, MgO and MgTiO3 structures were observed. But the new CeFeMgTisol sorbent before SO2 absorption, showed a separated MgO and TiO2 peak only. These differences in the sorption rates were discussed by the difference in the XRD pattern, surface area and pore volume.