Rotating corrugated photoreactor design: Experimental and computational analysis of TiO₂‐based photocatalysis

Abstract

A TiO 2 -coated rotating corrugated reactor is experimentally characterized and simulated for ultraviolet (UV)-based photo degradation of methylene blue (MB). Using degradation kinetics derived from flat-plate experiments and finiteelement discrete-ordinate models simulating spatially and temporally varying radiation patterns from a UV-lamp array, the simulated reactor performance is experimentally validated and extended to explore the impact of geometry variations. Mass-transfer limitations between the corrugated surface and the reservoir bulk are identified as a determining factor in the degradation rate of MB. Optimization studies suggest minimizing the corrugation half-angle to improve reactor performance for a given area, increasing the number of corrugations rather than the corrugation depth subject to practical limitations arising from undesirable bubble formation at small aperture widths. Given the relevance of mass transfer to this system, future work is needed to elucidate the experimental impact of reservoir volume and geometry while validating the use of flat-plate correlations for mass transfer.

A corrugated plate photocatalytic reactor for degradation of waterborne organic contaminants

“…The photocatalytic reaction relies on the flow to transport the reactant onto the catalytic surface, where the pollutant is adsorbed and the reaction occurs, and then to take degradation products away . Due to the surface reaction nature of the photocatalytic process, research on the photocatalyst surface flow profile/pattern has been crucial to optimizing reactor design . The reactor design in this paper is different from other reactors and the authors discuss experimental results from a fluid dynamic perspective in order to analyze the vital adsorption part of the process.…”

“…LASREA modelling being used to evaluate the reactor photon energy absorption in corrugated reactors has been reported, in which a diffuse emission model was adopted for lamp modelling. However, when calculating light intensity absorption, half sphere coordinates were applied, whereas a full sphere coordinate system was used for emitter light intensity modelling by others, which is considered reasonable in that the emitter on a lamp emits light rays in all directions.…”

“…However, when calculating light intensity absorption, half sphere coordinates were applied, whereas a full sphere coordinate system was used for emitter light intensity modelling by others, which is considered reasonable in that the emitter on a lamp emits light rays in all directions. The reactor light energy absorption profiles reported in the literature were all in two dimensions (2D) with one extruded from a 2D profile, and with simplified lamp surface modelling . For this work, a 3D LASREA profile was developed across the whole projected surface area of all of the lamp(s) in order to provide more precise energy absorption profiles.…”

“…The spectral absorption coefficient ɑ(λ) of the TiO 2 coating is the fraction of the absorbed incident energy of wavelength λ. The relationship is expressed in Equation : …”

“…Due to the surface reactions, the reactor should be configured for optimum mass transfer of oxygen, reactant, and product . In order to achieve these requirements, photocatalytic reactors with angled plates have been proposed, as they can accommodate more catalyst surface under a given illuminated area and absorb photon energy more effectively …”