Chemical Engineering & Technology, Vol.34, No.3, 400-408, 2011
Photocatalytic Degradation of a Gaseous Benzene-Toluene Mixture in a Circulated Photocatalytic Reactor
A circulated photocatalytic reactor (CPCR) was designed to enhance performance of the photocatalytic degradation of a gaseous mixture of aromatic volatile organic compounds (VOC) consisting of benzene and toluene in this study. The TiO2 film photocatalysts, characterized by FTIR and SEM, were prepared using the sol-gel method in low temperature and coating onto the inner wall of this reactor by bonder of poly-(2,2-dimethyl)-acrylic ethylene ester emulsion. The influences of the initial concentration and proportions of the mixture of toluene and benzene on the adsorption efficiency (A(i)), degradation efficiency (D-i), half-life (t(1/2)), and deactivation and regeneration of catalyst in the CPCR were investigated. The results indicated that the adsorption efficiency, degradation efficiency, and half-life were closely correlated to the initial concentrations of the mixture of toluene and benzene. The adsorption characteristics and kinetics of the photocatalytic degradation of the mixture were obtained based on the Langmuir-Hinshelwood-kinetic model. Furthermore, a series of new equations were developed. Finally, the reaction kinetics of the photocatalytic degradation of gaseous benzene or toluene in the CPCR was influenced by the interaction between benzene and toluene molecules.