In coal gasification process, sulfur compounds such as H2S and COS can be produced, due to the sulfur component in coal, and the hydrogen sulfide contained in coal derived synthetic gas can be selectively treated using the hot gas desulfurization process with a desulfurization sorbents. An SO2 reduction process is necessary for IGCC systems as clean coal technology, because SO2 is produced in the regeneration process of the sulfide sorbent. SO2 can be removed by recovering the elemental sulfur produced in the SO2 catalytic reduction process using a reducing agent. Various reducing agents such as hydrogen, carbon monoxide, methane, and carbonaceous materials have been used for the reduction of SO2. Carbon monoxide is used in the DSRP through the reaction (1)
SO2 + 2CO → 2CO2 + S (1)
S + O2 → SO2 (2)
The regeneration gas exhausted in the regenerator of hot gas desulfurization process contained the low content of unreacted O2, which is the remained oxygen in the re-oxidation of metal sulfide used as the desulfurization sorbent. Since, this oxygen can leads an oxidation of the elemental sulfur, the conversion of SO2 decreased due to the production of SO2 as through reaction(2). In order to find a suitable catalyst for DSRP, the Cu-Sn-Zr catalyst including noble-metal were prepared and their catalytic activity was examined in this study. The catalytic activity of Cu-Sn-Zr catalyst for SO2 reduction was confirmed in our previous study. In this study, the catalytic activity of Cu-Sn-Zr based catalyst including noble-metal was tested for SO2 reduction under oxygen. Experimental conditions were changed contents of noble-metal and O2 and SO2. The high catalytic activity of these catalysts was confirmed by the activity tests. The high conversion of SO2 and the yield of elemental sulfur could be obtained with Cu-Sn-Zr based catalyst including noble-metal for direct sulfur recovery process. however, at the all of experiment was confirmed catalytic sintering through SEM, XRD analysis. Therefore, in the next experiment sintering of the catalyst surface is prevent and maintain a high catalytic reactivity.