Removal of sulfur dioxide by fly ash/CaO/CaSO4 sorbents

This study presents findings from an experimental investigation of the influences of several factors on the desulfurization activity of sorbents synthesized from coal fly ash, CaO, and CaSO4. Specifically, the effects of specific surface area (16.1-133.3 m2/g), reaction temperature (60-300 °C), feed concentration of SO2 (500-2500 ppm), and feed concentration of NO (0-750 ppm) were elucidated using a fixed bed reactor. In general, the sorbent desulfurization activity increased with increasing specific surface area, reaction temperature, and NO concentration but with decreasing SO2 concentration. The physical and chemical properties of sorbent before and after SO2 capture were characterized through scanning electron microscopy, X-ray diffraction, and Fourier transform infrared analyses.