A laminar falling film slurry photocatalytic reactor. Part II - experimental validation of the model

The dimensionless mathematical model (LSSE-LSPP model) developed in Part I of this paper for a laminar falling film slurry (LFFS) photocatalytic reactor provides a method for scale-up and design of this type of reactor. Part II of the paper reports the experimental validation of the LSSE-LSPP model and a study of the sensitivity of the model with variations in the model parameters. The LSSE-LSPP model was used to calculate the rate of photocatalytic oxidation of salicylic acid in a pilot-scale LFFS photocatalytic reactor over a wide range of experimental conditions. The model results were found to fit the experimental data well, under conditions with varying substrate concentration, intensity of the incident radiation, catalyst loading, flow rates, recycle ratio and reactor geometry. The sensitivity analysis of the model parameters indicated that the reaction kinetics parameters are the major source of uncertainty in the modelling of photocatalytic reactors. The model revealed that, in the range of radiation wavelengths of 310-380 nm, light scattering in water suspensions of TiO2 (Degussa P25) is negligible at high optical thicknesses but cannot be neglected at low optical thicknesses. (C) 1998 Elsevier Science Ltd. All rights reserved.