Simultaneous removal of VOC and NO by activated carbon impregnated with transition metal catalysts in combustion flue gas

Activated carbon (AC) was conventionally sprayed into the incineration flue gas for controlling the emissions of volatile organic compounds (VOC) by adsorption at low temperature (200-250 degrees C). However, the spent carbons required to be further disposed with more energy. In the present study, the inertness and hydrophobic AC was used as support for transition metal catalysts (Cu, Co, Fe and Ni) to remove VOC by deep oxidation into CO2 and H2O2 and also to converse NO to N, with reduction at the temperature of 200-250 degrees C. The properties of the catalysts were analyzed by ICPMS, XPS, FTIR, BET and SEM. The chemical state of transition metals supported on AC playing a significant role in improving the ability of VOC adsorption or catalytic oxidation at low temperature. The XPS analysis proved that the oxidized and reduced metals were coexisted on the fresh catalysts, but there was only the oxidized metal on the spent catalysts. These investigations indicated that AC impregnated with transition metal catalysts had the potential to simultaneously remove VOC and NO at 250 degrees C, with Co/AC being found to have higher activity. (C) 2007 Elsevier B.V All rights reserved.