To improve the sulfur removing capacity of the conventional Zn-Ti-based H2S removal sorbents, a new Zn-Ti based sorbent (ZT-cp) was prepared by the coprecipitation method and tested in a packed bed reactor at middle temperature conditions (H2S absorption at 480 degrees C, regeneration at 580 degrees C). The new Zn-Ti-based sorbent showed excellent sulfur removing capacity without deactivation, even after 10 cycles of absorption and regeneration. The conventional Zn-Ti-based sorbents (ZT-700, ZT-1000), however, that were prepared by physical mixing, were continuously deactivated. In particular, the initial sulfur removing capacity of the ZT-cp sorbent showed a very high absorption value (0.22 g S/g sorbent), which corresponded to 91.6% of theoretical absorption amount. These results can be explained by the difference in physical properties such as pore volume, surface area, and particle size. It was also found that the sulfides formed from the ZT-cp and ZT-1000 sorbents with spinel structure were easily regenerated even at 580 degrees C. Those from the ZT-700 sorbent, with separated ZnO and TiO2 structures, needed a temperature higher than 610 degrees C for regeneration.

To improve the poor SO 2 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 MgSO 4 in the presence of low concentration of SO 2 at 973 K, regeneration of MgSO 4 to MgO and H 2 S in the presence of H 2 at 803 K). The CeFeMgTi-sol sorbent showed excellent SO 2 absorption and sulfur removal capacity (46.2 sulfur g/g absorbent×100). It was found that the SO 2 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, CeO 2 , MgO and MgTiO 3 structures were observed. But the new CeFeMgTisol sorbent before SO 2 absorption, showed a separated MgO and TiO 2 peak only. These differences in the sorption rates were discussed by the difference in the XRD pattern, surface area and pore volume.