Three-dimensional simulation of microcapillary and microchannel photo reactors for organic pollutant degradation from contaminated water using computational fluid dynamics

A three-dimensional (۳D) simulation of four photocatalytic microreactors is performed using mass and momentum balance equations. The simulated results are validated with the available experimental data for the photocatalytic removal of methylene blue (MB) in two microcapillaries as well as dimethylformamide (DMF) and salicylic acid (SA) in two microchannels. In the surface layers of the microreactor, a photo removal reaction takes place, and the kinetic rates are described by the Langmuir-Hinshelwood (L-H) model. The Damköhler number for these microreactors is less than one, which indicates that the mass transfer rate is limited by the reaction rate. The numerical study and kinetic constants determination are carried out by using computational fluid dynamic techniques. The ۳D modelpredictionsare ingood agreementwith the availableexperimental data sets. The results of the parametric study show that by increasing the microreactor length from ۵۰ to ۹۰mm, the removal efficiency improves from ۷۶% to ۹۳%. Moreover, the removal rate is increased by about ۴۰% by reducing the microchannel depth from ۵۰۰ to ۱۰۰ .

Keywords:

Microcapillary , Microchannel , Photocatalytic degradation , Langmuir–Hinshelwood , CFD