"VOC Destruction by Water Diluted Hydrogen Mild Combustion"

This study represents a preliminary evaluation of the effect of steam dilution and hydrogen addition on the oxidation of formaldehyde and benzene, chosen as representative of the Volatile Organic Compounds, in Mild condition by evaluating the autoignition time and the steady state attainment. These parameters are important in the design of thermal VOC destruction plants since they influence the abatement efficiency and, therefore, the plant dimension. It came out that steam dilution implies lower autoignition times and, on the other hand, longer times for the attainment of the steady state. In contrast, for very high water content there is an increase of the autoignition time. This implies that there is an optimum value of steam content that allows for the attainment of the steady state condition by the lowest residence time. Hydrogen addition to systems diluted in nitrogen promotes the oxidation reactions and anticipates the steady state condition. In in steam diluted systems hydrogen delays the autoignition of the mixtures even though anticipates the attainment of the complete destruction of the VOC. The rate of production analysis showed that the H2/O2 reactions that promote the ignition and the destruction of VOC are sensibly modified by the presence of water and hydrogen.