Numerical simulation of extraction columns using a drop population model

Kronberger, Thomas; Ortner, Andreas; Zulehner, Walter; Bart, Hans‐Jörg

doi:10.1016/0098-1354(95)87107-1

Cited by 30 publications

(12 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the present model, the basic variable is a drop size distribution function P(z,d,t,) which represents the volume fraction of drops with diameter d, in an unit volume of the column at level z and time t [4]. The local hold-up of the dispersed phase can be calculated from P(z,d,t) as follows 1)…”

Section: Model Equationsmentioning

confidence: 99%

A Genetic Algorithm Based Approach to Coalescence Parameters: Estimation in Liquid‐Liquid Extraction Columns

et al. 2006

View full text Add to dashboard Cite

The population balance model is a useful tool for the design and prediction of a range of processes that involve dispersed phases and particulates. The inverse problem method for the droplet population balance model is applied to estimate coalescences parameters for two-phase liquid-liquid systems. This is undertaken for two systems, namely toluene/water and n-butyl acetate/water in a rotating disc contactor (RDC), using a droplet population balance model. In the literature, the estimation procedure applied to this problem is often based on the deterministic optimization approach. These methods generate instabilities near a local minimum, inevitably requiring information about the derivatives at each iteration. To overcome these limitations, a method providing an estimate for the coalescences parameters is proposed. It is based on a simple and adapted structure of the genetic algorithm, for this particular problem. The agreement between the experimental observations and the simulations is encouraging and, in particular, the models used have proven to be suitable for the prediction of hold-up and Sauter diameter profiles for these systems. Finally, these results demonstrate that the optimization procedure proposed is very convenient for estimating the coalescences parameters for extraction column systems.

show abstract

Section: Model Equationsmentioning

confidence: 99%

A Genetic Algorithm Based Approach to Coalescence Parameters: Estimation in Liquid‐Liquid Extraction Columns

et al. 2006

View full text Add to dashboard Cite

show abstract

“…In the present model the basic variable is a drop size distribution function P(z,d,t) that represents the volume fraction of drops with diameter d in a unit volume of the column at level z and time t [5] 1) . The local holdup of the dispersed phase can be calculated from P(z,d,t) as follows:…”

Section: Model Equationsmentioning

confidence: 99%

“…The choice of the most appropriate model for calculating a given type of a liquid-liquid extraction column is not straightforward. Most of the recent models [5,6] aim to study the influence of breakup and coalescence rates in turbulent dispersions on hydrodynamics and mass transfer. Drop coalescence and breakage are key parameters for a fundamental understanding of the behavior of liquid-liquid dispersions in extraction columns.…”

mentioning

confidence: 99%

Assessment of Drop Coalescence and Breakup for Stirred Extraction Columns

et al. 2005

View full text Add to dashboard Cite

This work is a model assessment study considering two major hydrodynamic parameters: the holdup of the dispersed phase and the Sauter diameter. This is done for two different types of extraction columns, namely, the rotating disc contactor (RDC) and the Kühni column, using different drop breakup and coalescence models in a droplet population balance model. Based on the film drainage models for undeformable (spherical drops) and deformable drops with partially mobile interfaces, different simulations have been performed and the results compared with experimental values. The agreement between the experimental observation and the simulation is encouraging and the used models have proven to be suitable to predict holdup and Sauter diameter profiles for the system toluene/water. IntroductionExtraction columns are widely used in petroleum, pharmaceutical and chemical industries, mainly with physical extraction systems [1,2]. Their advantage is their high efficiency and low cost in respect of number of stages, solvent inventory, settler area, site area, maintenance, etc. [3, 4]. The choice of the most appropriate model for calculating a given type of a liquid-liquid extraction column is not straightforward. Most of the recent models [5,6] aim to study the influence of breakup and coalescence rates in turbulent dispersions on hydrodynamics and mass transfer. Drop coalescence and breakage are key parameters for a fundamental understanding of the behavior of liquid-liquid dispersions in extraction columns. These two processes are dynamic in nature and, in a turbulent flow field, depend on the drop sizes, the 552

show abstract

“…With larger columns and higher residence time, the model needs to be more complex, e.g. the droplet populance model [48].…”

Section: Hydrodynamicsmentioning

confidence: 99%

Reactive Extraction In Stirred Columns – A Review

Bart¹

2003

Chem Eng & Technol

View full text Add to dashboard Cite

The use of liquid ion exchangers enables one to perform selective separations with reactive extraction of species such as metal ions or acids. For the simulation of countercurrent column performance, three major outstanding issues have to be tackled: The first step is in a description of reactive equilibria, based on Gibbs excess modeling, taking into account complex formation involving aqueous electrolytes and organic species. In addition to physical extraction, the mass transfer co-efficient must be determined by taking into account diffusional and/or chemical reaction resistances. Finally, the column hydrodynamics have to be considered, where the state of the art design is to consider the deviation from plug flow with one parameter (e.g. the axial dispersion co-efficient). The development of droplet population methods, and the helpful information from CFD-calculations for the improvement of the physical understanding of complex flows, will be discussed. The use of lab-scale equipment to estimate all necessary design parameters involving a minimum of matter, is also presented.

show abstract

Numerical simulation of extraction columns using a drop population model

Cited by 30 publications

References 2 publications

A Genetic Algorithm Based Approach to Coalescence Parameters: Estimation in Liquid‐Liquid Extraction Columns

A Genetic Algorithm Based Approach to Coalescence Parameters: Estimation in Liquid‐Liquid Extraction Columns

Assessment of Drop Coalescence and Breakup for Stirred Extraction Columns

Reactive Extraction In Stirred Columns – A Review

Contact Info

Product

Resources

About