Preparation and Evaluation of Fe<sub>2</sub>O<sub>3</sub>/Ceramic Composites for Flue Gas Desulfurization

Abstract

Ceramic supported ferric oxide composites were synthesized by impregnation- precipitation (I) and sol-gel (II) methods using FeSO4as a precursor. We investigated the effect of the calcination temperatures on the structure, morphology, and agglomeration of supported ferric oxide. It has been found that Fe2O3was stabilized when the as-synthesized composites were calcinated at 330-360 °C under 10% (v/v) O2/N2mixture, and the calcination temperature was chosen as 350°C . The SEM images demonstrated that for the composite I, which was prepared by method (I), Fe2O3 nanoparticles were distributed on the surface and pores of the ceramic; while for the composite II, which was synthesized by method (II), Fe2O3thin layer was covered the surface of the ceramic. EDS analysis showed 7.9% (wt) ferric oxide had been supported on the composite I and up to 13.3% (wt) ferric oxide on the composite II. XPS analysis revealed that the valence of iron was +3 on both composites. Fe2O3/ceramic composites were used as the catalysts for low temperature wet Flue Gas Desulphurization (FGD), and demonstrated higher SO2removal efficiency. Because of the excellent hydrophilicity of ceramic and high dispersibility of Fe2O3 on ceramic surface, this catalyst had high SO2removal efficiency at 60°C even at pH2O3/ceramic composites, prepared by a simple, reproducible impregnation-precipitation and sol-gel method, was an inexpensive, active catalyst for S(IV) catalytic oxidation in wet FGD process in an economical feasible temperature range.