Catalytic Reduction of Nox and Unburned Carbon From Flue Gas By Packed Bed -Fe2O3 Process

摘要

The effect of simultaneous oxidization of unburned carbon and reduction of Nox in the presence of -Fe2O3 in the oxygen–rich environment were quantitatively determined in this study. The purposes of this research are to identify the reaction among -Fe2O3/ NO/C. Five different parameters: temperature, NO influent concentration, -Fe2O3 dosage, carbon dosage and O2 influent concentration, were tested in -Fe2O3 carbon packed column. Besides, the study contained NO flow of 300 mL/min. Under the carbon dosage of 2.0 g and -Fe2O3 dosage of 3.0 g at NO influent of 240 ppmv for 623 K, there was little NO reduction because of the lower temperature. For 673 K, 723 K and 773 K, complete removal for NO were achieved. The amount of NO (mg) reduction increased as temperature increased, and linearity was found with R2 = 0.9507. Furthermore the amount of NO (mg) reduction was increased as NO influent concentration increased under the NO influent concentration of 240 ~ 960 ppmv. When -Fe2O3 dosage was more than 0.5 g, complete removal for NO was accomplished because of the sufficient active surface of -Fe2O3. The time of CO produced was affected by carbon dosage, and the more carbon dosage added, the more amount of NO (mg) reduced. For effect of O2 influent concentration, the result indicated that the amounts of NO (mg) reduction decreased as O2 influent concentration increased. Chemical reactions among NO/O2 -Fe2O3/ carbon were proposed and verified by XRD analyses. According to the Xray diffraction (XRD) analytical results, the main equation is determined: C+1/2O2+Noα-Fe2O2→1/2N2+CO2