Eight-lamp externally irradiated bench-scale photocatalytic reactor: Scale-up and performance prediction

Valadés-Pelayo, Patricio J.; Sosa, F. Guayaquil; Serrano, Benito; Lasa, Hugo de

doi:10.1016/j.cej.2015.03.039

Cited by 15 publications

(18 citation statements)

References 36 publications

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“…(27)(28)(29) the SFM-HG scattering probabilities were calculated for each commercial photocatalyst (Table 3). In contrast to the SFM-DR [14] with scattering probabilities invariant with catalyst type (Table 3), the SFM-HG can now differentiate between photocatalysts types through the appropriate estimation of the HG asymmetry factor.…”

Section: Application Of Sfm-hg To Solar Heterogeneous Photocatalytic mentioning

confidence: 99%

Coupling the Six Flux Absorption–Scattering Model to the Henyey–Greenstein scattering phase function: Evaluation and optimization of radiation absorption in solar heterogeneous photoreactors

Acosta-Herazo

Monterroza-Romero

Mueses

et al. 2016

Chemical Engineering Journal

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Robust and practical models describing the radiation field in heterogeneous photocatalytic systems, used in emerging environmental, photochemical and renewable energy applications, are fundamental for the further development of these technologies. The sixflux radiation absorption-scattering model (SFM) has shown to be particularly suitable for the modeling of the radiation field in solar pilot-plant photoreactors. In this study, the SFM was coupled to the Henyey-Greenstein (HG) scattering phase function in order to assemble the model with a more accurate description of the scattering phenomenon provided by this IntroductionAs an emerging environmental technology, heterogeneous photocatalysis has received increasing attention in recent years. Its promising applications in air and water remediation[1], clean fuels production [2], green products (e.g. self-cleaning surface [3]) and selective 4 synthesis of organic molecules [4] demonstrates great interest in this technology. The underlying basis of every photocatalytic reaction mechanism is the photoactivation of the semiconductor photocatalyst by absorption of photons with energy higher or equal than the catalyst band-gap. The consequent generation of electron-hole pairs produces a chain of reactions that drive simultaneous oxidation and reduction (redox) reactions.The evaluation of the radiation field and of the spatial distribution of radiation absorption in a photoreactor system, commonly described by the local volumetric rate of photon absorption (LVRPA), is therefore a crucial aspect in the development of efficient photocatalytic processes [5].The LVRPA is the photon equivalent to the concentration of reactant species and is always considered in the description of the kinetics of photochemical reactions and in the optimization of the performance of photoreactors. For instance, several methodologies have been proposed for the determination of the optimum catalyst load or reactor thickness which maximize the absorption of radiation [6,7].The estimation of the LVRPA has been a defiant task within the heterogeneous photocatalysis community, as result of the complex nature of the absorption and scattering radiation phenomenon, which in the most rigorous case is modeled by the Radiative Transfer Equation (RTE). The RTE for a medium that does not emit radiation is [8]: where I λ is the photon irradiance at λ wavelength, s is a spatial coordinate, Ω is the directional solid angle, κ λ is the absorption coefficient and σ λ the scattering coefficient. TheΩ → Ω is the scattering phase function representing the probability of a photon to be redirected by scattering from the direction Ω', in surroundings of the position s, into the direction Ω [8]. A trivial solution for the RTE cannot be achieved and a numerical method is always necessary.Although the precise modeling of the LVRPA and a better understanding of the radiationphotocatalyst-operational conditions nexus still remains a challenge, several approaches have been proposed to solve the RTE. The most rigoro...

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Section: Application Of Sfm-hg To Solar Heterogeneous Photocatalytic mentioning

confidence: 99%

Coupling the Six Flux Absorption–Scattering Model to the Henyey–Greenstein scattering phase function: Evaluation and optimization of radiation absorption in solar heterogeneous photoreactors

Acosta-Herazo

Monterroza-Romero

Mueses

et al. 2016

Chemical Engineering Journal

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“…4 and (b) employing a Monte Carlo numerical probabilistic solution of Eq. 19, a method, a phase function, and suitable boundary conditions 23–25.…”

Section: Macroscopic Radiation Balancesmentioning

confidence: 99%

“…With these facts in mind, three type of laboratory scale units were developed in the CREC laboratories at the University of Western Ontario: (a) Photo‐CREC‐Water II, a centrally irradiated concentric slurry photocatalytic reactor 22–24, (b) Photo‐CREC‐Water III, an externally irradiated tubular slurry photocatalytic reactor 25, and (c) Photo‐CREC‐Air, an externally irradiated cross‐flow reactor with mesh‐immobilized photocatalyst 20. As a reference, Fig.…”

Section: Experimental Tools For Radiation Measurementsmentioning

confidence: 99%

“…6 provides a detailed diagram of the Photo‐CREC‐Water II. Detailed schematics of the Photo‐CREC‐Water III and Photo‐CREC‐Air are provided in Valades et al 25 and Garcia Hernandez et al 20, respectively.…”

Section: Experimental Tools For Radiation Measurementsmentioning

confidence: 99%

“…19 is required. In this particular case, a validated Monte Carlo method with properly selected phase functions as proposed by Valades‐Pelayo et al 25, 26 is strongly recommended.…”

Section: Experimental Tools For Radiation Measurementsmentioning

confidence: 99%

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Efficiency Factors in Photocatalytic Reactors: Quantum Yield and Photochemical Thermodynamic Efficiency Factor

et al. 2015

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Photocatalytic efficiency is evaluated using quantum yields (QYs) and the photochemical thermodynamic efficiency factor (PTEF). The PTEF allows establishing reactor efficiency as the ratio of utilized enthalpy for the formation of consumed OH . free radicals over the absorbed photon energy. A key consideration for the evaluation of efficiency factors is the establishment of macroscopic energy balances together with an accurate assessment of evolved and absorbed photons. Of considerable help are the experimental devices developed at the Chemical Reactor Engineering Centre (CREC)/University of Western Ontario (UWO) laboratories. Photoconversion kinetics is required for calculation of the OH . consumption rates and establishment of the related kinetic parameters. PTEFs and QYs have been applied by CREC-UWO researchers for efficiency calculations in photocatalytic reactors for the decontamination of air, water, and hydrogen production.

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Simulation of Photocatalytic Reactors

Akach¹,

Kabuba²,

Ochieng³

2023

Photoreactors in Advanced Oxidation Processes

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Eight-lamp externally irradiated bench-scale photocatalytic reactor: Scale-up and performance prediction

Cited by 15 publications

References 36 publications

Coupling the Six Flux Absorption–Scattering Model to the Henyey–Greenstein scattering phase function: Evaluation and optimization of radiation absorption in solar heterogeneous photoreactors

Coupling the Six Flux Absorption–Scattering Model to the Henyey–Greenstein scattering phase function: Evaluation and optimization of radiation absorption in solar heterogeneous photoreactors

Efficiency Factors in Photocatalytic Reactors: Quantum Yield and Photochemical Thermodynamic Efficiency Factor

Simulation of Photocatalytic Reactors

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