Computational fluid dynamic (CFD) simulation of a pilot-scale annular bubble column photocatalytic reactor

Pareek, Vishnu; Cox, Shane; Brungs, M. P.; Young, Brent R.; Adesina, Adesoji A.

doi:10.1016/s0009-2509(02)00617-6

Cited by 82 publications

(48 citation statements)

References 15 publications

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“…CFD analysis using FLUENT 6.0 software package was employed to investigate dependency of light intensity distribution on gas and liquid hydrodynamics, catalyst (titania) loading and optical characteristics of the medium. The RTE for the reactor simulation was solved using a finite-volume based discrete ordinate method [32]. As has been observed in laboratory bubble column reactors, the LVREA predicted in the pilot-scaled photocatalytic reactor increased with catalyst loading approaching a plateau at 1 g L À1 as seen in Figure 2.…”

Section: Photocausticisation Of Spent Industrial Bayer Liquor In a Bumentioning

confidence: 69%

“…Thus, it is advisable to carry out scale-up calculations on the basis of geometric and dynamic similarities [31]. To minimise experimental effort and fabrication costs at the pilotscale level, computational fluid dynamics (CFD) simulation of the scaled-up reactor would be necessary to identify regions in parameter space for detailed inquiry [32].…”

Section: Pilot-scale Trialsmentioning

confidence: 99%

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Industrial exploitation of photocatalysis: progress, perspectives and prospects

Adesina

2004

Catal Surv Asia

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151

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The removal of numerous organic pollutants from aqueous media using titania photocatalysis has motivated the need for commercial application of this technology for tertiary wastewater treatment and water purification. A discussion of the development of visible light-activating catalysts, pilot-scale multiphase reactor analysis and case studies with industrial significance is presented. An overview of different solar photocatalytic reactors is also given.

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Section: Photocausticisation Of Spent Industrial Bayer Liquor In a Bumentioning

confidence: 69%

Section: Pilot-scale Trialsmentioning

confidence: 99%

Industrial exploitation of photocatalysis: progress, perspectives and prospects

Adesina

2004

Catal Surv Asia

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151

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“…Because this approach is based on general computational fluid dynamics, the hydrodynamic and radiation transport equations can be solved concurrently to allow more accurate photoreactor designs. The predicted LVREA data can be used to calculate the reaction rates at various reactor points and can be used in the continuity equation to predict the overall conversion (Pareek et al, 2003c …”

Section: Discussionmentioning

confidence: 99%

“…In the FV method, the RTE is integrated over both the control angle and the control volume, unlike the DO method, in which the RTE is integrated over the control volume only. In the FV method, apart from the spatial discretization, a relatively new concept of the control angle is involved Mathur, 1998, 2000;Pareek et al, 2003c;Raithby and Chui, 1990). In 2-D, the control angle is simply an angle as shown in Figure 2a and the summation of these angles will be 2.…”

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confidence: 99%

Light intensity distribution in a photocatalytic reactor using finite volume

Pareek

Adesina

2004

AIChE Journal

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A conservative variant of discrete ordinate model was used to solve the radiation transport equation. The model prediction was used to assess the effect of wall reflectivity, catalyst loading, and phase function parameter on the light intensity distribution in an annular heterogeneous photocatalytic reactor. For relatively low catalyst loadings, thewall reflectivity strongly influenced the light intensity distribution. However, for an optically thick medium, the wall reflectivity had very little or no effect. The volumeaverage light intensity distribution decreased rather sharply with the catalyst loading and an opposite trend was obtained for the local volumetric rate of energy absorption (LVREA). However, after the initial sharp increase, the LVREA appeared independent of catalyst loading. For nonreflecting reactor walls, phase function parameter did not show much influence. However, for the specularly reflecting reactor walls and optically thin mediums, a moderate dependency on the phase function parameter was observed. AIChE J, 50: 1273AIChE J, 50: -1288AIChE J, 50: , 2004 Keywords: photocatalytic reactor, radiant transport, light intensity distribution, wall reflectivity, light volumetric rate of energy absorption (LVREA) © 2004 American Institute of Chemical Engineers IntroductionThe involvement of radiation is the single most important factor that distinguishes the photochemical/photocatalytic reactor from the conventional thermally activated reactive processes. The rate of initiation (in case of photocatalysis, electron-hole formation) step in photochemical reaction is directly dependent on the light intensity (Cassano et al., 1995). Because the step of electron-hole formation is a fast one (time constant Ϸ 10 15 s Ϫ1 ), in a well illuminated reactor, it may be expected that light intensity will not be a rate determining step. However, it is highly difficult to maintain a uniform light intensity within a reactor space and the intensity distribution invariably determines the overall conversion and reactor performance. The radiation transport equation (RTE) that describes the light intensity distribution is an integrodifferential equation, and an exact analytical solution is possible only for highly ideal one-dimensional situations (Carvalho and Farias, 1998). For photocatalytic reactors, however, because of light scattering in the presence of titania particles, it is impossible to find an analytical solution for the RTE. Therefore, to reliably design a photocatalytic reactor, use of new and efficient numerical methods is desired to solve the RTE in the reaction domain of interest. Furthermore, an overall design of the reactor system will require a simultaneous solution of flow equations (e.g., Navier-Stokes equation). It is, therefore, important to investigate the photocatalytic systems using a computational fluid dynamics (CFD) approach so that the effects of flow and radiation attributes can be combined. Most of the current commercial CFD codes use finite-volume scheme to numerically solve the conserva...

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“…The application of CFD in reaction engineering is well known and has been applied in many other areas of chemical engineering and chemical reaction engineering, 24 such as fluidization, [25][26][27] and multiphase flow systems, [28][29][30][31] and more recently, it has been utilized for simulation of photocatalytic reactors. 17,24,[32][33][34][35] Pareek et al 33 applied the CFD approach to model an annular photoreactor and analyze its performance for possible industrial wastewater treatment. A granular Eulerian approach was used to simulate the three-phase flow in a photocatalytic reactor.…”

Section: Introductionmentioning

confidence: 99%

Three‐dimensional CFD model for a flat plate photocatalytic reactor: Degradation of TCE in a serpentine flow field

Jarandehei

Visscher

2008

AIChE Journal

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in Wiley InterScience (www.interscience.wiley.com).Computational fluid dynamics (CFD) simulation was applied to a photocatalytic reactor with surface reaction for trichloroethylene (TCE) oxidation at various pollutant concentrations, and flow rates. First-order and Langmuir-Hinshelwood kinetics for TCE removal rate were considered. The results were compared with those from experiments of Demeestere et al. (Appl Catal B Environ. 2004;54:261-274) in a flat plate photocatalytic reactor with serpentine geometry. The flow regime was laminar. Through the CFD simulation, the velocity field and the concentration gradient of TCE in the reactor were studied in detail. At Reynolds numbers around 900, the laminar flow becomes unstable. Under such a condition, when flow passes the 1808 sharp turns, due to formation of secondary flow and consequently vortices, there is a lot of crosssectional mixing in the reactor. This kind of studies can help us to model the photocatalytic reactor as accurately as possible.

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Computational fluid dynamic (CFD) simulation of a pilot-scale annular bubble column photocatalytic reactor

Cited by 82 publications

References 15 publications

Industrial exploitation of photocatalysis: progress, perspectives and prospects

Industrial exploitation of photocatalysis: progress, perspectives and prospects

Light intensity distribution in a photocatalytic reactor using finite volume

Three‐dimensional CFD model for a flat plate photocatalytic reactor: Degradation of TCE in a serpentine flow field

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