Novel-doped zinc oxide sorbents for low temperature regenerable desulfurization applications

Abstract

Eight metal oxide sorbents including transition metal doped ZnO/SiO2 sorbents and ZnO/SiO2 were prepared by incipient wetness impregnation for regenerable desulfurization applications at low temperatures (i.e. room temperature). Among them, copper-doped sorbent (Cu-ZnO/SiO2) demonstrated the highest saturation sulfur capacity of 0.213 g sulfur/g ZnO (54% of the theoretical capacity), which is twice that of ZnO/SiO2 sorbent. Compared with ZnO/SiO2, Cu-ZnO/SiO2 demonstrated superior desulfurization performance in a wide temperature range of 20-400°C. Due to the use of porous SiO2 support, Cu-ZnO/SiO2 is highly regenerable. It can be easily regenerated in air at low temperatures, ca. 300-550°C, which are much lower than the typical regeneration temperatures of commercial ZnO sorbents. Cu-ZnO/SiO2 maintained its sulfur capacity during 10 cycles of regeneration/sulfidation. © 2010 American Institute of Chemical Engineers (AIChE).