Electronic Thesis and Dissertation Repository

Degree

Doctor of Philosophy

Program

Chemical and Biochemical Engineering

Supervisor

Dr. Hugo I. de Lasa

Abstract

The present study focuses on developing a predictive methodology to scale-up a slurry annular photoreactor using a TiO2 Degussa P25 from the bench-scale to a pilot-plant scale. The bench-scale photoreactor is a Photo-CREC-Water II, a 2.65 L internally-irradiated slurry annular photocatalytic reactor. The pilot-plant scale photoreactor is a Photo-CREC Water Solar Simulator, a 9.8 L pilot-plant photoreactor, externally irradiated by eight lamps.

The adopted methodology allows the independent validation of radiative and kinetic models avoiding cross-correlation issues. The proposed approach involves two Monte Carlo methods, to model the Radiative Transfer Equation (RTE) inside each photoreactor. With this end, a novel probe is developed to measure irradiance at different radial positions for improved RTE parameter estimation This allows determining both adequate boundary conditions in the photo-CREC-Water II unit as well as establishing a phase function for Degussa P25 TiO2.

On the other hand, a kinetic model and kinetic parameters are established by carrying out photocatalytic degradations of a model pollutant (Oxalic Acid). Kinetic experiments are developed at different photocatalyst concentrations and various irradiance conditions. Additionally, convective and dispersive transport models are proposed and solved by Finite Element (FE) Method to determine the photocatalyst irradiation time in each photoreactor unit and ultimately to predict the overall photocatalytic efficiency. Finally the kinetic-irradiance based model is validated. This is done by predicting irradiance profiles and degradation rates at different photocatalyst concentrations and irradiance conditions on the larger Photo-CREC Water III (Photo CREC Water Solar Simulator) photoreactor.