Authors: T.C. Wang, H.Y. Kang, H.P. Wang, J.G. Jou, J.L. Wei
Affilation: National Cheng Kung University, Taiwan
Pages: 639 - 641
Keywords: desulfurization, nanosize ZnO, XANES, EXAFS
Thermal efficiencies of an integrated gasification combined cycle (IGCC) process can be enhanced with high-temperature desulfurization. Nanosize, sub-nano (clusters) and atomic-dispersed ZnO has been prepared for the high-temperature desulfurization. An enhanced absorbance of the nanosize ZnO at 9668 eV is found by X-ray absorption near edge structure (XANES) spectroscopy (Figure 1). ZnO clusters are also observed in the channels of MCM-41. By temperature programmed sulfurization (TPS) and oxidization (TPO), it is found that the nanosize ZnO can be effectively sulfurized and regenerated (with air) at 940-950 K (Figure 2). The smaller ZnO clusters in MCM-41 can be sulfurized at relatively lower temperatures (700-820 K). The atomic dispersed ZnO on TiO2 having the strong metal-support interactions cannot be sulfurized at the temperature of < 960 K, and interestingly, regenerated at much lower temperatures (i.e., <650 K). It seems that the nanosize or atomic dispersed ZnO may be desired for the high-temperature desulfurization especially for a high efficiency IGCC based electric power generation.