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Investigation into Photocatalytic Degradation of Gaseous Benzene in a Circulated Photocatalytic Reactor (CPCR)
Author(s) -
Geng Q.J.,
Guo Q.J.,
Cao C.Q.,
Wang H.Q.
Publication year - 2008
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.200700510
Subject(s) - photocatalysis , benzene , adsorption , catalysis , degradation (telecommunications) , chemical engineering , reaction rate constant , chemistry , kinetics , reaction rate , materials science , nuclear chemistry , inorganic chemistry , organic chemistry , telecommunications , physics , quantum mechanics , computer science , engineering
Due to the fact that suspended TiO 2 powder enjoys free contact with gaseous pollutant molecules in photocatalytic reactors, it can generally achieve better efficiency than immobilized TiO 2 catalysts. However, difficulties with the separation of this catalyst powder from treated pollutants and its re‐use often limit its application. Therefore, a circulated photocatalytic reactor (CPCR) was designed to enhance the performance of the photocatalytic degradation of gaseous benzene. TiO 2 film photocatalysts were prepared by the sol‐gel method at low temperatures and coated onto the inner wall of this reactor by a bonding agent composed of poly‐(2, 2‐dimethyl)‐acrylic ethylene ester emulsion in which TiO 2 powder was characterized by FTIR, TEM and SEM. In particular, the influences of initial concentration and gas flow rate of benzene on the degradation conversion, D p , apparent reaction rate constants, k r , initial degradation rate, r , and the deactivation and regeneration of catalyst in the CPCR, were investigated. The results indicated that the degradation conversion, apparent reaction rate constants and initial degradation rate were closely correlated to the initial concentration of benzene. To elucidate the factors governing the observations, the adsorption characteristics and kinetics of the photocatalytic degradation of benzene were analyzed using the Langmuir adsorption isotherm and Langmuir‐Hinshelwood kinetic model. It was found that the reaction kinetics were best described by a fixed pseudo‐first‐order kinetic equation of photocatalytic degradation of gaseous benzene in the CPCR.