Review on Measurement Techniques for Drop Size Distribution in a Stirred Vessel

Abidin, Mohd Izzudin Izzat Zainal; Raman, Abdul Aziz Abdul; Nor, Mohamad Iskandr Mohamad

doi:10.1021/ie401548z

Cited by 37 publications

(22 citation statements)

References 62 publications

(186 reference statements)

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“…A broad overview on existing measurement techniques was found by Abidin et al They described the different methods of measurement which can be classified into in situ and external measurement. Two main groups of measurement techniques were reviewed by Abidin et al Several issues regarding the applications of the techniques and possible ways to overcome the problems were discussed.…”

Section: Methodsmentioning

confidence: 99%

Cross Linking Between the Baffling Effect and Phase Inversion During Liquid–Liquid Monomer Mixing

Cocke

Maaß

2017

Macro Reaction Engineering

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remains one of the most difficult and least understood mixing problems, in contempt of its major significance for optimization of suspension polymerization. The first step of the process, the liquid-liquid mixing and even more the medium conversion stage with increased dispersed phase viscosity and sticky polymer-monomer particles already determines the size of the final particle size distribution.Xie et al. are introducing this major challenge and give a meaningful introduction about suspension polymerization. [1] It has been widely used to produce poly-(vinyl chloride), poly-(vinylidene chloride) copolymers, polystyrene, poly-(methyl methacrylate), and high value-added polymer particulate products (e.g., chromatographic separation media, ion exchange resins, and enzyme immobilization supports). During the suspension polymerization process, a monomer (or monomers) that is immiscible or slightly soluble in water is first dispersed to form monomer droplets by stirring in the aqueous phase containing a dispersant-the liquid-liquid mixing process.Recent studies have revealed unexpected developments in drop size by only small changes in the geometrical constraints of batch vessels used for suspension polymerization. The effect of the dispersed phase fraction, surfactant concentration, as well as baffle length on the evolving drop size distribution in different low viscous liquid-liquid systems is investigated. The analysis is focused on the drop-dominated systems by hindering the coalescence by polyvinyl alcohol (PVA) concentrations up to three times higher than the critical micelle concentration. The influence of PVA on drop size in breakage-dominated systems is well reproduced with population balance equation simulations. The drops are measured using a photo-optical system with automated image analysis. The measured drop sizes increase with increasing dispersed phase fraction. As coalescence is completely hindered, all observed coalescence effects are connected to phase inversion, a catastrophic phenomenon during suspension polymerization for industrial production processes. Phase inversion can be reproduced for all studied solvents with and without the use of surfactants. In particular, the influence of the baffles can be reproduced. The system is adapted and trained to detect phase inversion as a warning system to make the suspension polymerization process more stable and robust.

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Section: Methodsmentioning

confidence: 99%

Cross Linking Between the Baffling Effect and Phase Inversion During Liquid–Liquid Monomer Mixing

Cocke

Maaß

2017

Macro Reaction Engineering

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“…Therefore, various experiments have been carried out, analysing the drop size as a function of reactor design parameters, operating conditions and physical characteristics of the l-l dispersion. A broad overview of existing measurement techniques can be found in (Abidin et al, 2013). They describe the different methods of measurement which can be classified into in-situ and external measurement.…”

Section: Drop Size Measurementsmentioning

confidence: 99%

“…They describe the different methods of measurement which can be classified into in-situ and external measurement. Two main groups of measurement techniques are reviewed by Abidin et al (2013). Several issues regarding the applications of the techniques and possible ways to overcome the problems are discussed.…”

Section: Drop Size Measurementsmentioning

confidence: 99%

Photo-Optical In-Situ Measurement of Drop Size Distributions: Applications in Research and Industry

Panckow

Reinecke²,

Cuellar

et al. 2017

Oil Gas Sci. Technol. – Rev. IFP Energies nouvelles

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-The exact knowledge of Drop Size Distributions (DSD) plays a major role in various fields of applications to control and optimise processes as well as reduce waste. In the microbial production of advanced biofuels, oil droplets are produced under turbulent conditions in an aqueous medium containing many surface active components, which might hinder the recovery of the product. Knowledge of DSD is thus essential for process optimisation. This study demonstrates the capability of a photo-optical measurement method for DSD measurement in fermentation broth and in plate separators aimed at cost reduction in the microbial production of advanced biofuels. Measurements were made with model mixtures in a bioreactor, and at the inlet and outlet of a plate separator. In the bioreactor, the method was effective in detecting a broad range of droplet sizes and in differentiating other disperse components (e.g. microbial cells and gas bubbles). In the plate separator, the method was effective in determining the influence of the varied parameters on the separation efficiency.Résumé -Mesure photo-optique in-situ de la distribution des taille des gouttes : applications dans la recherche et l'industrie -La connaissance approfondie de la distribution du diamètre des gouttelettes joue un rôle important dans des diverses applications des contrôles et d'optimisations des processus, de plus elle permet de réduire le gaspillage. Pendant la production microbienne de biocarburants avancés, des gouttelettes d'huiles sont produites sous les effets des turbulences du milieu aqueux contenant beaucoup de substances tensio-actives, ce qui pourrait entraver la récupération du produit. La connaissance de la distribution du diamètre des gouttelettes est donc essentielle pour l'optimisation des processus. Cette étude montre les possibilités offertes par une méthode de mesure photo-optique pour les mesures de la taille des gouttelettes dans des bouillons de fermentations et dans des séparateurs à plaques, ceci vise à réduire les coûts dans la production microbienne de biocarburants avancés. Les mesures ont été effectuées avec des mélanges modèles dans un bioréacteur ainsi qu'à l'entrée et à la sortie d'une plaque de séparation. Dans le bioréacteur, le procédé est efficace dans la détection d'une large gamme de tailles de gouttelettes et dans la différenciation des autres composants dispersés (par exemple des cellules microbiennes et des bulles de gaz). Dans le séparateur à plaque, le procédé est efficace, car il détermine l'influence de différents paramètres sur l'efficacité de la séparation.Oil & Gas Science and Technology -Rev. IFP Energies nouvelles (2017) 72, 14 Ó R.P. Panckow et al., published by IFP Energies nouvelles, 2017 DOI: 10.2516 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. LIST OF SYMBOLS AND/OR NOT...

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“…Also, due to the restriction of this method to Ha > 3, it cannot be used for the present cases of nBAL aldol condensation at industrial operating conditions where 0.3 < Ha < 1.5. As an alternative, the measurement of the interfacial area using a borescope is a direct and in situ method . In this technique, actual droplet pictures in a biphasic stirred tank are taken by a CCD camera with a borescope.…”

Section: Introductionmentioning

confidence: 99%

“…The drop‐size distribution and interfacial area are obtained directly from counting droplets in the pictures . This method, despite labor‐intensive droplet counting, is acknowledged to be the most accurate method to obtain the interfacial area . Because the aldol reaction is at 80–140°C and temperature can influence the interfacial area, the temperature effect has to be considered.…”

Section: Introductionmentioning

confidence: 99%

Aldol condensation of n‐butyraldehyde in a biphasic stirred tank reactor: Experiments and models

Lee

Varma

2015

AIChE Journal

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To model a biphasic stirred tank reactor, intrinsic reaction kinetics and interfacial area are required. In this study, reactor modeling for n-butyraldehyde aldol condensation was investigated under industrially relevent conditions. The interfacial area in the reactor was directly measured using a borescope system under appropriate temperature, NaOH concentration and rpm conditions. To estimate the interfacial area, a semi-empirical correlation was developed, which provides good estimates within ±15% error. The reactor model based on two-film theory was developed, combining the interfacial area and intrinsic reaction kinetics reported in our prior work. The model was verified by reaction experiments in the range 0.05-1.9M NaOH, 80-130 o C and 600-1000 rpm. The prediction errors using the interfacial area from direct measurements and the correlation were ±8% and ±15%, respectively, suggesting that the model accuracy may be improved with better interfacial area estimation.Topical Area: Reaction Engineering, Kinetics and Catalysis

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Review on Measurement Techniques for Drop Size Distribution in a Stirred Vessel

Cited by 37 publications

References 62 publications

Cross Linking Between the Baffling Effect and Phase Inversion During Liquid–Liquid Monomer Mixing

Cross Linking Between the Baffling Effect and Phase Inversion During Liquid–Liquid Monomer Mixing

Photo-Optical In-Situ Measurement of Drop Size Distributions: Applications in Research and Industry

Aldol condensation of n‐butyraldehyde in a biphasic stirred tank reactor: Experiments and models

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