Monte Carlo simulation of the light distribution in an annular slurry bubble column photocatalytic reactor

Photocatalytic water splitting with noble‐metal free cocatalysts for a comprehensive study of two nonidentical photoreactors designs

“…The concentration of 1 g/L for annular reactor (10 cm inner diameter), can be considered very high and it is very likely that dark regions were formed. It was reported in the literature that LVREA profiles of annular reactors with smaller inner diameters like, 0.85, 2.6, 3.52, and 6.5 cm, obtained optimal TiO 2 concentrations (1.0, 0.25, 0.14, and 0.4 g/L, respectively) lower than that used in the present study 34,36‐38 Another way to evaluate the differences in H 2 production of the two photoreactors is by the apparent quantum yield (AQY) described in the Supplementary Material.…”

“… The first operational difference observed between the systems is the perfect homogenization of reaction system A throughout the time interval guaranteed by a magnetic stirrer. The fluid movement plays an important role in a reaction system, as it provides a homogeneous distribution of reagents, pollutants, catalysts, temperature and bubbles within the reactor, but it does not guarantee the photoreactor isoactinicity, that is, the uniform light distribution in the reactor volume 36,39,55 . The absence of agitators (reaction system B) may be an advantage as it makes the cost less expensive and facilitates the scale‐up of photoreactor designs like quartz ones with an external radiation source attached to a refractory panel.…”

“…Light distribution in the reactor is the basis of design parameters for photocatalytic reactors, such as local volumetric rate of energy absorption (LVREA) profiles, which refer to the amount of radiation absorbed by the photocatalyst particle per unit of time and volume. LVREA profiles are widely used in the literature to determine the optimal photocatalyst concentration to avoid dark zone formation since it is clear from their direct relationship that a possible increase in catalyst concentration can affect light penetrability in the reaction medium 19,34‐39 . According to the authors, the LVREA profile when evaluated on the photoreactors' radial axis indicates an exponentially decrease as it approaches the inner wall of the reactor, that is, when most of the photons are being absorbed or scattered closer to the lamp 34‐36 …”

“…LVREA profiles are widely used in the literature to determine the optimal photocatalyst concentration to avoid dark zone formation since it is clear from their direct relationship that a possible increase in catalyst concentration can affect light penetrability in the reaction medium. 19,[34][35][36][37][38][39] According to the authors, the LVREA profile when evaluated on the photoreactors' radial axis indicates an exponentially decrease as it approaches the inner wall of the reactor, that is, when most of the photons are being absorbed or scattered closer to the lamp. [34][35][36] There are few studies comparing the effect of the catalyst on hydrogen production under the same operating and experimental conditions in reactors of different geometries.…”

Design and performance evaluation of a photocatalytic reactor for indoor air disinfection

“…Stochastic simulation methods, like the Monte Carlo method, are preferred to solve radiation models in reactors with complex geometries (Moreira et al 2010). The Monte Carlo method has been successfully employed to evaluate the photon absorption distribution inside reactors with different geometries, radiation sources, and catalyst arrangements (Imoberdorf et al 2010;Zazueta et al 2013;Marugán et al 2015;Akach and Ochieng 2018).…”