The Sulfur Dioxide Removal and Regeneration Properties of MgO-Based Sorbents Promoted with Ceria and Iron Oxide

摘要

Nano-size MgO-based sorbents that were promoted with ceria and iron oxide were prepared using the coprecipitation method. The sulfur removing capacity and the role of ceria and iron oxide promoters were investigated using a fixed-bed reactor and X-ray diffraction (XRD). The ceria played an important role in the catalytic oxidation of SO_2 to SO_3 which could be easily absorbed by the MgO. In order for sulfate absorption to occur, SO_2 must be oxidized to SO_3 before absorption to a pure MgO. The iron oxide exhibited a lowering of the regeneration temperature of the sulfated sorbent under a residue fluid catalytic cracking (RFCC) condition. These results can be explained by the presence of iron oxide particles that interact strongly with MgO support. The MgO-based sorbent that was promoted with ceria and iron oxide showed excellent characteristics in that it could satisfy a large amount of SO_2 absorption and fast regeneration.