Kinetic parameter estimation and flow modeling of a photocatalytic reactor for waste gas treatment.

摘要

In this study two different methodologies have been utilized to model a photocatalytic reactor with a serpentine geometry for the degradation of trichloroethylene (TCE). Once the relevance of charge trapping in photocatalysis was established, the kinetic parameters of a kinetic model considering the effect of this phenomenon were estimated based on experimental data of Demeestere et al. [1] using flow models developed through simplified mass balance equations. It was found that although this kind of modeling gives useful information about the system, a more powerful methodology is needed to better explain the results and understand the fluid flow properties. Therefore, the Computational Fluid Dynamics (CFD) simulation was applied to provide a more realistic hydrodynamic model and consequently more accurate estimation of kinetic parameters. In the CFD modeling, first order and Langmuir-Hinshelwood (LH) kinetics for TCE removal rate were considered. The flow regime was laminar with a range of Reynolds numbers of 161 ≤ Re ≤ 972. However, at the higher end of these Reynolds numbers, the laminar flow becomes unstable. Through the CFD simulation, the velocity field and the concentration gradient of TCE in the reactor at various pollutant concentrations, 100 to 500 ppm, and gas residence times, 10 to 60.3 s were studied in detail.