Silica versus Alumina towards Ozonation Reactivity for Removal of VOCs: Effect of Temperature, Ozone Concentration and Porous Area

The effect of temperature, ozone concentration and porous area on toluene conversion, using alumina and silica was investigated. There appeared a maximum rate of toluene conversion as the ozone concentration increased. With area 150m 2 on both of alumina and silica, the optimal ozone concentration was 125gr/Nm 3 for all temperature ranges. In the presence of ozone, toluene conversion over alumina increased at least 55%, in comparison with ozone free mode while this amount was about 100% over silica. In addition, toluene conversion increased with area so that even at low temperatures such as 50 o C, especially over alumina, toluene conversion was about 100%. In ozonation, if sufficient area of porous material were available, then effect of temperature on toluene conversion was marginal while effect of temperature on toluene removal in the presence of air is considerable. Narrow size distribution of alumina in comparison with silica resulted in higher toluene conversion, even at low temperatures. In other words, alumina is more active than silica, in toluene conversion in similar conditions.

Keywords:

VOC-Toluene-ozonation-silica-alumina