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

Abstract

An advanced flue gas conditioning technology was developed through in situ oxidation of SO 2 using dielectric barrier discharge and heterogeneous condensation of SO 3 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 cm 2 of discharge area; single factor experiment was introduced here to investigate impacts of various elements (gas flux, temperature, concentration of SO 2 and relative humidity) on oxidation of SO 2 , results showed that the oxidation of SO 2 was in inverse proportion to gas flux and SO 2 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 À1 was detected by the FTIR analysis, which indicated that SO 3 generated by in situ oxidation of SO 2 could be successfully absorbed by the surface of FA particles. The specific resistance of conditioning FA showed a remarkable decrease from 1.41 Â 10 13 to 5.74 Â 10 11 Ω cm compared with the untreated sample.

Effect of Particulate Matter Mineral Composition on Environmentally Persistent Free Radical (EPFR) Formation

“…With that said, there is evidence to show that sulfur compounds have an effect on particulate formation from incineration processes. 38,39 …”

“…Third, introduction of large lime or limestone quantities indicates high concentrations of SO 2 in the systemsit is possible that SO 2 interacts with metal centers and prevents the formation of EPFRs. With that said, there is evidence to show that sulfur compounds have an effect on particulate formation from incineration processes. , …”

“…With that said, there is evidence to show that sulfur compounds have an effect on particulate formation from incineration processes. 38,39 It is unclear which scenario is applicable to MWI ash, but the data may provide vital information on ways to control EPFR formation/emission from combustion sources. Indeed zinc, identified earlier as an EPFR active metal, is the prominent surface element in MEDWI ashes, which also contained EPFRs.…”