Deposition and aggregation of Brownian particles in trickle‐bed reactors

Iliuta, Ion; Larachi, Faı̈çal

doi:10.1002/aic.11023

Cited by 8 publications

(5 citation statements)

References 53 publications

(73 reference statements)

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“…Argyle et al have reviewed heterogeneous catalyst deactivation; defined as the loss of catalyst activity or selectivity over time . The catalyst in a fixed bed reactor deactivates during operation over time for a variety of reasons: ,,,,,,− (1) poisoning, (2) fouling (coking), (3) thermal degradation and sintering (aging, hardening, or agglomeration), (4) metal leaching accompanied by transport from the catalyst surface or particle, (5) vapor formation, (6) vapor–solid or solid–solid reactions (chemical routes rather than thermal), and (7) attrition/crushing.…”

Section: Trickle Bed Reactor (Tbr) and Respective Critical Parametersmentioning

confidence: 99%

Fixed Bed Continuous Hydrogenations in Trickle Flow Mode: A Pharmaceutical Industry Perspective

Masson

Maciejewski

Wheelhouse

et al. 2022

Org. Process Res. Dev.

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Since the 1930s, fixed bed reactors (FBR) have been operated for continuous hydrogenation reactions in the petrochemical/fine chemical industries, with publications each year detailing engineering principles, scientific breakthroughs, equipment design and setup, from these industries. Only in the last two decades, FBR have started to be utilized in the pharmaceutical industry as a result of sustainability commitment and growing demand of complex and specialized drugs. Most of the engineering knowledge is transferable across industries; however, there are differentiators inherent to each industry, with the pharmaceutical industry having its own unique challenges. One of the main differentiators between industries is the reactor scale and, consequently, reactor catalyst requirements. Petrochemicals or fine chemicals operate on a large industrial scale, with up to 72 m high reactors, with an internal diameter on the order of 5 m (China Petroleum & Chemical Corporation), and require large volumes of catalysts because of the high product demand for thousands of tonnes per year, while for the pharmaceutical industry, a smaller scale reactor is required for product demand in the thousands of kilograms per year range. It is the reactor size that defines catalyst specifications, such as particle size and geometry. Many transformations have emerged from academic and medicinal chemistry groups utilizing the ThalesNano H-Cube; however, there are relatively few reported processes that have been scaled within the pharmaceutical industry. This Perspective outlines a review of continuous flow hydrogenation technologies; focusing on the trickle bed reactor (TBR) and the respective process operation and effect of process variables on reaction rate requirements for the pharmaceutical industry; it also reflects on transformation examples using TBR across the pharmaceutical industry.

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Section: Trickle Bed Reactor (Tbr) and Respective Critical Parametersmentioning

confidence: 99%

Fixed Bed Continuous Hydrogenations in Trickle Flow Mode: A Pharmaceutical Industry Perspective

Masson

Maciejewski

Wheelhouse

et al. 2022

Org. Process Res. Dev.

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“…One of the important aspects not addressed in the literature is the aggregation of fines and the detachment of fine particles/aggregates during plugging with Brownian particles. To address this issue, Iliuta and Larachi (2006a) attempted to develop an Euler–Euler fluid dynamic model, which accounts for the filtration equations for the Brownian particles/aggregates as well as the discrete population balance equations for the agglomeration of particles. The model is proposed for the description of two‐phase flow and deposition/aggregation/release of Brownian fine solids in high‐pressure/temperature TBRs.…”

Section: Cfd Modelling and Simulation Of Trickle‐bed Reaction Systemsmentioning

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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“…They developed transfer functions to predict the hydrodynamic parameters such as the liquid hold up, liquid phase Pećlet number, and wetting efficiency. 6 Iliuta and Larachi 7 studied the fines release from the catalyst bed and their aggregation due to the hydrodynamics and colloidal forces in a TBR. Using the Euler−Euler fluid dynamic model, volume average transport conservation rules, Brownian motion, discrete population balance for particles, and the aggregate filtration equations, they modeled the aggregation behavior.…”

Section: Introductionmentioning

confidence: 99%

“…The Brownian particle aggregation was explained by the rate at which a definite aggregate size was obtained from smaller aggregates. 7 Tukačet al 8 assessed the scale up performance of hydrodynamic parameters such as pressure drop and wetting efficiency in bench (continuous) and pilot (periodic) TBRs.…”

Section: Introductionmentioning

confidence: 99%

“…Using the Euler–Euler fluid dynamic model, volume average transport conservation rules, Brownian motion, discrete population balance for particles, and the aggregate filtration equations, they modeled the aggregation behavior. The Brownian particle aggregation was explained by the rate at which a definite aggregate size was obtained from smaller aggregates . Tukač et al assessed the scale up performance of hydrodynamic parameters such as pressure drop and wetting efficiency in bench (continuous) and pilot (periodic) TBRs.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dynamic Modeling Strategy To Assess Impacts of Hydrodynamic Parameters on Industrial Hydropurification Process by Considering Catalyst Deactivation

Azarpour

Rezaei

Zendehboudi

2018

Ind. Eng. Chem. Res.

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In this study, modeling and simulation of the dynamic behavior of an industrial-scale trickle bed reactor (TBR) with application to a hydropurification process for production of purified terephthalic acid (PTA) are carried out. The impacts of hydrodynamic parameters such as reactor bed porosity, liquid hourly space velocity (LHSV), and liquid–solid and gas–liquid mass transfer coefficients on the industrial hydropurification TBR performance (in particular, on the catalyst lifetime) are analyzed. As the palladium supported on carbon (Pd/C) catalyst deactivates with time, the concentration of impurities in the product, especially 4-carboxybenzaldehyde (4-CBA) as the main impurity of PTA, increases. The three-phase dynamic mathematical model developed in this research work is validated against the plant data, and an average relative error of 2.2% is obtained for the concentration of 4-CBA. The lifetime of the catalyst based on plant data is 348.2 ± 5.0 days; this value is estimated to be 365.1 days from the simulation results, showing a 4.8% error. According to the sensitivity analysis on the model parameters, the effects of LHSV and bed porosity are in the same direction and magnitude, while the effects of the liquid–solid and gas–liquid mass transfer coefficients are in the opposite direction, and their impacts are also less significant. These parameters are disturbed in a range of up to ±15%, compared to the normal operating conditions that results in an absolute catalyst lifetime change of 2.9%–14.2%. The maximum and minimum variations in the catalyst lifetime are obtained when LHSV is disturbed by ±10%, exhibiting a catalyst lifetime change of 14.2% at a −10% disturbance (416.9 days) and −6.5% at a +10% disturbance (341.3 days). A +15% disturbance in the liquid–solid mass transfer coefficient increases the catalyst lifetime by 2.9% (375.8 days), and a −15% disturbance decreases this vital parameter by 3.7% (351.8 days). Eventually, the findings of this study might be applied to the relevant industrial sectors, providing the required close and meticulous control of the process.

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Deposition and aggregation of Brownian particles in trickle‐bed reactors

Cited by 8 publications

References 53 publications

Fixed Bed Continuous Hydrogenations in Trickle Flow Mode: A Pharmaceutical Industry Perspective

Fixed Bed Continuous Hydrogenations in Trickle Flow Mode: A Pharmaceutical Industry Perspective

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

Dynamic Modeling Strategy To Assess Impacts of Hydrodynamic Parameters on Industrial Hydropurification Process by Considering Catalyst Deactivation

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