Flue gas conditioning by in situ oxidation of so2 applying dielectric barrier discharge

Abstract

ABSTRACTAn advanced flue gas conditioning technology was developed through in situ oxidation of SO2 using dielectric barrier discharge and heterogeneous condensation of SO3 on fly ash (FA). Orthogonal experiments were carried out for the design of discharge structure, whereas the optimal condition was achieved at 8 kV of discharge voltage, 2 mm of discharge gap and 56 cm2 of discharge area; single factor experiment was introduced here to investigate impacts of various elements (gas flux, temperature, concentration of SO2 and relative humidity) on oxidation of SO2, results showed that the oxidation of SO2 was in inverse proportion to gas flux and SO2 concentration, whereas in direct proportion to relative humidity, the optimal temperature was detected at 45 °C. Physical and chemical characterizations of treated samples were performed in this work using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR). Particle coagulation was found in the SEM, and a continuous peak rise of sulfate at 1086 cm−1 was detected by the FTIR analysis, which indicated that SO3 generated by in situ oxidation of SO2 could be successfully absorbed by the surface of FA particles. The specific resistance of conditioning FA showed a remarkable decrease from 1.41 × 1013 to 5.74 × 1011 Ω cm compared with the untreated sample. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.