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Energy & Fuels 2005, 19, 170-179
H2S Absorption Behavior of Calcium Ferrite Prepared in the Presence of Coal Na-oki Ikenaga,* Yousuku Ohgaito, and Toshimitsu Suzuki Department of Chemical Engineering, Kansai University, 3-3-35 Yamate, Suita, Osaka 564-8680, Japan Received April 14, 2004. Revised Manuscript Received October 4, 2004
Calcium ferrite (CaFe2O4) absorbents of hydrogen sulfide (H2S) for hot-gas cleaning were prepared in the presence of Yallourn coal (YL). Calcium and iron nitrates in aqueous solution were impregnated onto YL, which was then dried at 70 °C in vacuo and calcined at various temperatures in air. The performance of the absorbent was evaluated using a fixed-bed flowtype reactor that was equipped with a quadrupole mass spectrometer. The surface area of the YL char-loaded CaFe2O4 (CaFe2O4/YL) was ca. 25 m2/g, and its value was the same order of magnitude as those of unloaded ferrites that had been prepared by a coprecipitation method. The morphological structures of CaFe2O4/YL showed a rough surface with a macroporous structure; however, the surface of unloaded ferrites prepared by the dry process and the coprecipitation method was smooth and flat. When the absorption behaviors of CaFe2O4/YL for H2S were measured at 500 °C, the absorption capacity of H2S with CaFe2O4/YL exhibited almost 100% of the stoichiometric amount of loaded metal species and could efficiently remove 4000 ppm of H2S to a level of
