Abstract:

Mg-rich Mg-Al spinel synthetized by Sol-Gel method and modified with CuO and CeO2 via co-gelling method was used to remove SO2 from FCC flue gas. Synthetic catalysts were evaluated on a fixed bed reactor and characterized with XRD, XPS, and Raman Spectra etc. Spinel with an mg-al ratio of 1:1 showed the highest SO2 removal activity. After modification of CuO and CeO2, it kept a desulfurization rate of 90.67% after 40 minutes. It was found that the generation of MgO-CuO solid solution was prevented in the presence of CeO2. So CuO had a better dispersion on the adsorbent surface and showed a better catalytic oxidation activity. At the same time, when CuO was added, oxygen defects were found in the lattice of CeO2 by Raman spectra. That improved the oxygen adsorption capacity of the catalyst. High catalytic oxidation activity and oxygen adsorption capacity of the catalyst enormously promote oxidation of SO2 to SO3, which is much easier to be adsorbed by spinel.

Key words: FCC fuel gas, desulfurization, Mg-Al spinel, CuO, CeO2