STUDIES OF NO REMOVAL FROM FLUE GAS BY ZERO VALENT IRON

摘要

A novel technology to remove NO by zero valent iron (ZVIR) in a column study was conducted. Kinetic effects were determined based on the effluent concentrations and the operated temperatures versus time, and breakthrough curve was achieved for four different temperatures for influent concentration of 400 ppm NO. The results showed that when the temperature was increased, the reaction rate was increased, and first order reaction kinetic was determined accordingly. Rate constants k for the four operating temperatures can thus be fitted into Arrhenius equation and the activation energy (Ea) and frequency factor between ZVIR and NO can be determined as 13.7 kcal/mol and 2.1x10~6 s~(-1), respectively. The calculated Ea is slightly lower than the theoretical calculation by a thermodynamic computational software EQS4WIN (19.5 kcal/mol), but is higher than the result shown in other literature (10.8 kcal/mol). Moreover, when the reaction temperature was increased, the total amount of NO removed by ZVIR was also significantly increased. Since there were only less than 1 % ZVIR used to remove NO comparing to theoretical ZVIR used based on stoichiometry, it can be concluded that the heterogeneous reaction was only occurred on the ZVIR surface instead of bulk of the ZVIR. Electron Spectroscopy for Chemical Analysis was conducted to analyze the resulting species on the ZVIR surface and FeO was shown on the ZVIR surface.