LLECMOD (Liquid-Liquid Extraction Column Module) is a windows based program that is developed (Attarakih et al., 2006, 2008) to simulate liquid extraction columns. Liquid-liquid extraction is an important separation processes encountered in many chemical process industries. Due to its complex hydrodynamic nature (caused by droplet interactions (namely: breakage and coalescence), detailed modelling on a discrete level is needed using the population balance equation as a mathematical framework. Simulation of liquid–liquid extraction columns based on a droplet population balance approach provides a useful means for getting more insight into the transient and steady state column behaviour. A comprehensive model for predicting the interacting hydrodynamics and mass transfer is formulated on the basis of a spatially distributed population balance equation in terms of the bivariate number density function with respect to droplet diameter and solute concentration. The two macro- (droplet breakage and coalescence) and micro-(interphase mass transfer) droplet phenomena are allowed to interact through the dispersion interfacial tension. The resulting model is composed of a system of integro-partial differential and algebraic equations that are dominated by convection, and hence it calls for a specialized discretization approach. Under the frame work of the developed model the steady state and dynamic performance of extraction columns can be investigated taking into account the effect of dispersed phase inlet (light or heavy phase is dispersed) and the direction of mass transfer (from continuous to dispersed phase and vice versa).

Existing simulation software does not have such a comprehensive mathematical models capable to describe extraction columns’ behaviour on the basis of droplet interactions (breakage, coalescence, droplet velocity...etc). Unlike existing modules in commercial flowsheeting programs, this model implements non-equilibrium bivariate population balance models (droplet size and solute concentration) distributed over the columns’ spatial domain.

Two types of extraction modules are actually implemented: these are agitated RDC and Kühni columns and pulsed sieve plate and packed columns. Using the developed model as a simulation tool, scale-up and simulation of agitated and non-agitated extraction columns based on the population balance model can now be carried out successfully. These sophisticated mathematical models are programmed in LLECMOD, using Visual Digital FORTRAN with optimized and efficient numerical algorithms. Recent correlations for fluid dynamics and mass transfer are now available and are extensively validated against experimental data collected from pilot and industrial columns.

References:

- M. M. Attarakih, Hans-Jörg Bart and N. M. Faqir (2006). LLECMOD A Windows-based program for hydrodynamics simulation of liquid–liquid extraction columns, Chemical Engineering and Processing 45: 113-123.

- M. J. Goodson (2006). Stochastic Solution of Multi-Dimensional Population Balances. PhD thesis, Trinity College, University of Cambridge, Cambridge.

- M.M. Attarakih, H.-J.Bart, T. Steinmetz, M. Dietzen and N.M. Faqir (2008). LLECMOD: A Bivariate Population Balance Simulation Tool for Liquid - Liquid Extraction Columns, Open Chem. Eng. J., 2: 10-34.

LLECMOD Publications:

Papers:

- M. M. Attarakih, Hans-Jörg Bart and N. M. Faqir (2006). LLECMOD A Windows-based program for hydrodynamics simulation of liquid–liquid extraction columns, Chemical Engineering and Processing, 45: 113-123.

- Hans-Jörg Bart (2006), From Single Droplet to Column Design, Tsinghua Science & Technology, 11(2): 212-216.

- H.-J. Bart, C. Drumm and M. M. Attarakih (2008), Process intensification with reactive extraction columns, Chemical Engineering and Processing: Process Intensification, 47(5): 745-754.

- M.M. Attarakih, H.-J.Bart, T. Steinmetz, M. Dietzen and N.M. Faqir (2008). LLECMOD: A Bivariate Population Balance Simulation Tool for Liquid - Liquid Extraction Columns, Open Chem. Eng. J., 2: 10-34.

- M. Jaradat, M. Attarakih and H.-J. Bart (2010), Effect of phase dispersion and mass transfer direction on steady state RDC performance using population balance modelling, Chemical Engineering Journal, 165 (2): 379-387.

- M. Jaradat, M. Attarakih and H.-J. Bart (2011), Advanced Prediction of Pulsed Extraction Column Performance using LLECMOD, (CM)2-Young Researcher Symposium Proceedings: 22-27, 15 February 2011, Kaiserslautern-Deutschland.

- H. B. Jildeh, M. Attarakih and H.-J. Bart (2011), An Inverse Problem Method for RDC Simulation, (CM)2-Young Researcher Symposium Proceedings: 45-49, 15 February 2011, Kaiserslautern-Deutschland.

- M. Jaradat, M. Attarakih, M. Hlawitschka and H.-J. Bart (2011), Mathematical Modelling of Liquid-Liquid Extraction Columns, To appear in ESCAPE 21, 29 May – 1 June, 2011- Greece.

- M. Jaradat, M. Attarakih and H.-J. Bart, Advanced Prediction of Pulsed (packed and sieve) Extraction Columns Performance Using Population Balance Modelling, submitted to Chemical Engineering Research and Design-IChemE.

Presentations:

- M. Jaradat, M. Attarakih and H.-J. Bart (2008). Investigation of Extraction Column (RDC) Performance using Population Balance Equation (PBE). The annual meeting of the ProcessNet specialized committee extraction and the working group Phytoextrakte, 16-18 April 2008, Clausthal-Zellerfeld-Deutschland.

- M. Jaradat, M. Attarakih and H.-J. Bart (2008). Liquid-Liquid Extraction Column Simulation Module (LLECMOD). ReDrop Workshop, 15 May 2008, RWTH Aachen-Deutschland.

- M. Jaradat, M. Attarakih and H.-J.Bart (2009). Effect of Mass Transfer Direction on Extraction Column Performance using Population Balance Equation (PBE), ProcessNet Fachausschüsse CFD, Extraktion & Mischvorgänge, 30-31 March 2009, Fulda- Deutschland.

- M. Jaradat, M. Attarakih and H.-J. Bart (2009). Advanced Prediction of Extraction Column Performance Using Population Balance Equation (PBE), ACHEMA 2009, 11-15 May 2009, Frankfurt-Deutschland.

- M. Jaradat, M. Attarakih and H.-J. Bart (2011), Advanced Prediction of Pulsed Extraction Column Performance using LLECMOD, (CM)2-Young Researcher Symposium, 15 February 2011, Kaiserslautern-Deutschland.

- H. B. Jildeh, M. Attarakih and H.-J. Bart (2011), An Inverse Problem Method for RDC Simulation, (CM)2-Young Researcher Symposium, 15 February 2011, Kaiserslautern-Deutschland.

- M. Jaradat, M. Attarakih and H.-J. Bart (2011), Simulation of Liquid-Liquid Extraction Columns Using LLECMOD, Jahrestreffen der ProcessNet-Fachausschüsse Extraktion, Fluidverfahrenstechnik, Mehrphasenströmungen und Phytoextrakte, 3-4 Mach 2011, Fulda-Deutschland.

- M. Jaradat, M. Attarakih, H. B. Jildeh, H.-J. Bart (2011), Pulsed columns performance prediction using LLECMOD, 8th European Congress of Chemical Engineering (ECCE 2011), 25-29 September 2011, Berlin, Germany.

- H. Jildeh, M. Attarakih and H.-J. Bart (2011), A User Friendly Program used for Simulating Liquid-Liquid Extraction Columns, Workshop Mulm und ReDrop, 22-23 September 2011, AVT - Thermische Verfahrenstechnik , RWTH Aachen University, Aachen, Germany.