Modeling, simulation and control of liquid-liquid extraction columns

Weinstein, Oleg; Semiat, Raphael; Lewin, Daniel R.

doi:10.1016/s0009-2509(97)00310-2

Cited by 46 publications

(32 citation statements)

References 13 publications

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“…In this control scheme the outlet continuous flow rate is manipulated to control the position of the interface at the top of the column. The velocity model corresponding to this scheme shows an oscillatory behaviour in the dispersed phase hold-up as reported both experimentally by Hufnagl et al [56] and theoretically by Weinstein et al [14] and Attarakih et al [19]. Fig.…”

Section: Continuous Phase Velocity Modelssupporting

confidence: 75%

LLECMOD: A Bivariate Population Balance Simulation Tool for Liquid- Liquid Extraction Columns

Attarakih¹,

Bart²,

Steinmetz³

et al. 2008

TOCENGJ

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Abstract:The population balance equation finds many applications in modelling poly-dispersed systems arising in many engineering applications such as aerosols dynamics, crystallization, precipitation, granulation, liquid-liquid, gas-liquid, combustion processes and microbial systems. The population balance lays down a modern approach for modelling the complex discrete behaviour of such systems. Due to the industrial importance of liquid-liquid extraction columns for the separation of many chemicals that are not amenable for separation by distillation, a Windows based program called LLECMOD is developed. Due to the multivariate nature of the population of droplets in liquid -liquid extraction columns (with respect to size and solute concentration), a spatially distributed population balance equation is developed. The basis of LLECMOD depends on modern numerical algorithms that couples the computational fluid dynamics and population balances. To avoid the solution of the momentum balance equations (for the continuous and discrete phases), experimental correlations are used for the estimation of the turbulent energy dissipation and the slip velocities of the moving droplets along with interaction frequencies of breakage and coalescence. The design of LLECMOD is flexible in such a way that allows the user to define droplet terminal velocity, energy dissipation, axial dispersion, breakage and coalescence frequencies and the other internal geometrical details of the column. The user input dialog makes the LLECMOD a user-friendly program that enables the user to select the simulation parameters and functions easily. The program is reinforced by a parameter estimation package for the droplet coalescence models. The scale-up and simulation of agitated extraction columns based on the populations balanced model leads to the main application of the simulation tool.

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Section: Continuous Phase Velocity Modelssupporting

confidence: 75%

LLECMOD: A Bivariate Population Balance Simulation Tool for Liquid- Liquid Extraction Columns

Attarakih¹,

Bart²,

Steinmetz³

et al. 2008

TOCENGJ

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“…The population of droplets is modelled by a multivariate number concentration function, which takes into account the dynamic evolution of droplet size and solute concentrations. The understanding of liquid-liquid extraction columns dynamic behavior can be notably used in the design of process control strategy or the start-up and shutdown procedures [8][9][10][11]. In attempting to model this dynamic behavior, one has to consider the macroscopic dispersed phase interactions (droplet breakage and coalescence) as well as the microscopic interaction (interphase mass transfer) occurring in the continuously turbulent flow field, which results in a distributed population of droplets.…”

Section: The Mathematical Modelmentioning

confidence: 99%

LLECMOD: A Bivariate Population Balance Simulation Tool for Pulsed Liquid-Liquid Extraction Columns

Jaradat¹,

Attarakih²,

Steinmetz³

et al. 2012

TOCENGJ

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A rigours mathematical model based on the bivariate population balance frame work (the base of LLECMOD ''Liquid-Liquid Extraction Column Module'') for the steady state and dynamic simulation of pulsed liquid-liquid extraction columns is developed. The model simulates the coupled hydrodynamic and mass transfer for pulsed (packed and sieve plate) extraction columns. It is implemented using visual digital FORTRAN and then integrated into the LLECMOD program. Experimental validated correlations are used for the estimation of the droplet terminal velocity in extraction columns based on single and swarm droplet experiments in laboratory scale devices. Additionally, recently published correlations for turbulent energy dissipation, droplet breakage and coalescence frequencies are discussed as being used in this version of LLECMOD. In a case study, LLECMOD is used here to simulate the steady state performance of pulsed extraction columns with two chemical test systems recommended by the European Federation of Chemical Engineering (water-acetone-n-butyl acetate and water-acetone-toluene) and an industrial test system. Model predictions are successfully validated against steady state and transient experimental data, where good agreements are achieved. The simulated results (holdup, mean droplet diameter and mass transfer profiles) compared to the experimental data show that LLECMOD is a powerful simulation tool, which can efficiently predict the dynamic and steady state performance of pulsed extraction columns.

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“…In the present work, the simplified model of Handlos and Baron (1957) as used by many researches (Zhang et al, 1985;Weinstein et al, 1998) as well as the correlation of Kumar and Hartland (1999) are used. However, the criterion based on the Reynolds number as suggested by Zhang et al (1985) may be used as a guide for selecting the proper mass transfer model.…”

Section: Mass Transfer Coefficientsmentioning

confidence: 99%

“…The individual mass transfer coefficient for the continuous phase is essentially subjected to the aforementioned classification procedure, where two models are used to predict it. The first simple one is based on the film coefficient equation as recommended by Weinstein et al (1998), and the second one is based on the correlation of Kumar and Hartland (1999) for RDC LLECs. Now, once the individual mass transfer coefficients are estimated, the rate of change of solute concentration in the liquid droplet (ċ y ) is expressed in terms of the droplet volume average concentration and the overall mass transfer coefficient, K oy :…”

Section: Mass Transfer Coefficientsmentioning

confidence: 99%

Numerical solution of the bivariate population balance equation for the interacting hydrodynamics and mass transfer in liquid–liquid extraction columns

Attarakih

Bart

Faqir

2006

Chemical Engineering Science

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Modeling, simulation and control of liquid-liquid extraction columns

Cited by 46 publications

References 13 publications

LLECMOD: A Bivariate Population Balance Simulation Tool for Liquid- Liquid Extraction Columns

LLECMOD: A Bivariate Population Balance Simulation Tool for Liquid- Liquid Extraction Columns

LLECMOD: A Bivariate Population Balance Simulation Tool for Pulsed Liquid-Liquid Extraction Columns

Numerical solution of the bivariate population balance equation for the interacting hydrodynamics and mass transfer in liquid–liquid extraction columns

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