Photocatalytic degradation of toluene in a staged fluidized bed reactor using TiO₂/silica gel

Relatively high concentration toluene is photocatalytically degraded in a multi-stage fluidized bed reactor continuously. The fluidizing media are titanium dioxide deposited silica gel particles, which are prepared by the doping sol-gel method. The effects of the Ti/Si atomic ratio, the inlet gas flow rates, and the number of the stages on the toluene removal efficiency were evaluated. The highest toluene removal efficiency is obtained when the fluidizing media are with the Ti/Si atomic ratio of 1.25. The apparent reaction orders are 0.4-0.5 for the single-stage system and 0.7 for the two-stage system, respectively. With an inlet toluene concentration of 1,000 ppm, a relative humidity of 30% and a volumetric flow rate of 10 L/min, the removal efficiency of toluene at the steady state is as high as 80% and is maintained in the 6-hr experimental time.