Onset of pulsing in gas–liquid trickle bed filtration

Iliuta, Ion; Larachi, Faı̈çal

doi:10.1016/j.ces.2003.12.020

Cited by 14 publications

(17 citation statements)

References 34 publications

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“…Thus, a limited number of experimental works on the process of fines accumulation 2,5,23,24 and only some attempts concerning the modeling and conceptualization of dynamics of fines deposition have been reported. 3,4,25,26 The few available experimental studies showed that the pressure drop increases monotonically with the concentration of fine particles and this increase correlates well with the reduction in effective porosity arising from the accumulation of the fines. All the experimental studies suggest that the major change resulting from deposition of fine particles involves the effective size and geometry of catalyst particles, the surface characteristics of the catalyst particles, the porosity, and the effective porosity of the bed.…”

Section: Introductionmentioning

confidence: 77%

“…Currently, physical models linking gas-liquid flow to the filtration process in trickle beds neglected the possible release of fine particles 3,4,25,26 and the potential beneficial impact of induced pulsing to reduce the plugging in trickle beds. An attempt has therefore been made in this work in which the authors sought to develop a dynamic multiphase flow model based on the volume average mass, momentum, and species balance equations.…”

Section: Introductionmentioning

confidence: 99%

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Stretching operational life of trickle‐bed filters by liquid‐induced pulse flow

Iliuta

Larachi

2005

AIChE Journal

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Section: Introductionmentioning

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Stretching operational life of trickle‐bed filters by liquid‐induced pulse flow

Iliuta

Larachi

2005

AIChE Journal

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“…In the literature, up to now the CFD application in trickle‐bed systems has been largely limited to the trickling‐flow regime. A few researchers have also attempted to address the prediction of trickling‐to‐pulsing regime by coupling CFD approach and linear stability analysis (Attou and Ferschneider, 1999; Iliuta and Larachi, 2004c; Lopes and Quinta‐Ferreira, 2010d).…”

Section: Physical Description and Flow Patterns In Tbrsmentioning

confidence: 99%

Modelling and simulation of trickle‐bed reactors using computational fluid dynamics: A state‐of‐the‐art review

2011

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Trickle-bed reactors (TBRs), which accommodate the flow of gas and liquid phases through packed beds of catalysts, host a variety of gas-liquid-solid catalytic reactions, particularly in the petroleum/petrochemical industry. The multiphase flow hydrodynamics in TBRs are complex and directly affect the overall reactor performance in terms of reactant conversion and product yield and selectivity. Non-ideal flow behaviours, such as flow maldistribution, channelling or partial catalyst wetting may significantly reduce the effectiveness of the reactor. However, conventional TBR modelling approaches cannot properly account for these non-ideal behaviours owing to the complex coupling between fluid dynamics and chemical kinetics. Recent advances in the application of computational fluid dynamics (CFD) to three-phase TBR systems have shown promise of achieving a deeper understanding of the interactions between multiphase fluid dynamics and chemical reactions. This study is intended to give a state-of-the-art overview of the progress achieved in the field of CFD simulation of TBRs over the past two decades. The fundamental modelling framework of multiphase flow in TBRs, advances in important constitutive models, and the application of CFD models are discussed in detail. Directions for future research are suggested.RÉSUMÉ Les lits fixes arrosésà co-courant descendant de gaz et de liquide sont le siège d'innombrables processus catalytiques triphasiques, en particulier dans le domaine du raffinage pétrolier et de la pétrochimie. Les caractères polyphasique et non-idéal de leur hydrodynamique ont des répercussions importantes sur la conversion chimique, la productivité et la sélectivité. Ceci se traduit par l'entremise de la maldistribution des fluides, le mouillage partiel du catalyseur ou desécoulements préférentiels qui peuventêtre déterminants en ce qui a traità l'efficacité du réacteur. La mise enéquation rigoureuse de ces non-idéalités et des couplages réaction-hydrodynamique a longtemps résisté aux approches de conceptualisation dites « conventionnelles ». Cette revue de synthèse s'attarde par conséquentà discuter les récentes avancées dans l'utilisation de la mécanique des fluides numérique comme outil «émergent et non-conventionnel » de description quantitative et fine desécoulements et des réactions catalytiques, et de leur interaction au sein de ces réacteurs. Spécifiquement, nous discuterons de la pertinence des différentes approches multi-fluides mises en oeuvre, des relations constitutives développées et de l'utilisation de la mécanique des fluides numérique pour des applications pratiques des lits fixes arrosés. Nous suggérerons en guise d'épilogue de nouvelles directions de recherche dans ce domaine.Mots clés: Lit fixe arrosé, mécanique des fluides numérique, hydrodynamique polyphasique,équations constitutives tive amination, liquid-phase oxidation, etc.). TBRs are also used for the catalytic abatement of aqueous biocidal compounds in *

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“…In contrast, the literature still remains rather scanty with respect to the complex hydrodynamics and surface phenomena involved in the plugging with fine particles of packed‐bed gas–liquid–solid reactors despite the critical operational problem of fines in the petroleum refining industry. Thus, a limited number of experimental works on the process of fines accumulation6, 7, 12, 13 and only some attempts concerning the modeling and conceptualization of fines deposition dynamics have been reported 14–19. The few available experimental studies showed that the pressure drop increases monotonically with the concentration of fine particles and this increase correlates well with the reduction in effective porosity arising from the accumulation of fines.…”

Section: Introductionmentioning

confidence: 99%

“…Currently, physical models linking gas–liquid flow to the filtration process in trickle beds neglect the possible colloidal particle aggregation and release of aggregates and fine particles 14–16, 19. An attempt was thus made in the present study in which the authors sought to develop a Euler–Euler fluid dynamic model based on the volume average mass, momentum, and species balance equations, filtration equations for the Brownian particles and the aggregates, and the discrete population balance equations for the agglomeration of particles.…”

Section: Introductionmentioning

confidence: 99%

Deposition and aggregation of Brownian particles in trickle‐bed reactors

Iliuta

Larachi

2006

AIChE Journal

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in Wiley InterScience (www.interscience.wiley.com).When dilute liquid suspensions contaminated with Brownian fine solids are treated in catalytic trickle-bed reactors, bed plugging develops and increases the resistance to two-phase flow until ultimate unit shutdown for bed substitution with pristine catalyst is imposed. One of the important aspects during plugging with Brownian particles is the aggregation of fines and the release of the fine particles and aggregates from pore bodies within the porous bed as a result of the hydrodynamic or colloidal forces. Current physical models linking gas-liquid flow to the filtration process in high-pressure/ temperature trickle beds neglect the possible colloidal particle aggregation and the release of aggregates. This work attempts to fill this gap by developing a Euler-Euler fluid dynamic model based on the volume average mass, momentum, and species balance equations, filtration equations for the Brownian particles and the aggregates, and the discrete population balance equations for the agglomeration of particles. Both monolayer and multilayer depositions were considered for Brownian particles and only the monolayer deposition in the case of the detaching aggregates. The release of fine particles and aggregates from the collector surface was assumed to be induced by the colloidal forces in the case of Brownian particles/aggregates or by the hydrodynamic forces in the case of non-Brownian aggregates. Brownian particle aggregation was described by the rate at which a certain size aggregate is being formed by smaller aggregates less the rate at which the aggregate combines to form a larger aggregate.

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Onset of pulsing in gas–liquid trickle bed filtration

Cited by 14 publications

References 34 publications

Stretching operational life of trickle‐bed filters by liquid‐induced pulse flow

Stretching operational life of trickle‐bed filters by liquid‐induced pulse flow

Modelling and simulation of trickle‐bed reactors using computational fluid dynamics: A state‐of‐the‐art review

Deposition and aggregation of Brownian particles in trickle‐bed reactors

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