Predicting Mass Transfer in Liquid–Liquid Extraction Columns

Abstract

In this work, the GEneralised Multifluid Modelling Approach (GEMMA) is applied to the simulation of liquid–liquid extraction in a Rotating Disc Column (RDC) and a Pulsed Sieve-plate Extraction Column (PSEC). A mass transfer modelling methodology is developed, in which the multiphase flows, droplet size distribution and dispersed phase holdup predicted with computational fluid dynamics are coupled to mass transfer correlations to predict the overall mass transfer. The numerical results for the stage-averaged dispersed phase holdup, Sauter mean droplet diameter and axial solute concentration in the RDC and PSEC agree with experimental observations. The proposed modelling method provides an accurate predictive tool for complex multiphase flows, such as those observed in intensified liquid–liquid extraction, and provides an alternative approach to column design using empirical correlations or pilot plant study.

Mass transfer performance of pulsed disk and doughnut column (PDDC) in the extraction of active ingredients in peppermint extract obtained by hot percolation

“…Among of suitable methods for this purpose is liquid-liquid extraction (LLE), which is a key operation in many separation processes in chemical, pharmaceutical, environmental, food, nuclear, and hydrometallurgy industries to recover materials in dilution. [13][14][15][16][17][18][19][20][21][22] The primary extracts obtained from the traditional extraction processes such as percolation and HD can be used as feed for LLE columns to separate better the active ingredients from herbs. HD is one of these traditional techniques for extracting the active ingredients from herbs, which has become an interesting field of study.…”

“…In PDDCs, baffles in the form of discs and doughnuts have been used, which help the extraction by improvement of the contact between two immiscible liquids, and the pulses in this column cause better breaking of droplet and improve the mass transfer. [19,26,27] The main hydrodynamic characteristics in PDDCs, including the slip velocity, dispersed phase holdup, continuous phase holdup, and flow regimes, [13,15,[28][29][30][31][32][33][34][35] play a key role in LLE and mass transfer systems. [20,[36][37][38] All the mentioned cases are difficult to investigate and have complex hydrodynamic behaviour and mass transfer function.…”

“…Among of suitable methods for this purpose is liquid–liquid extraction (LLE), which is a key operation in many separation processes in chemical, pharmaceutical, environmental, food, nuclear, and hydrometallurgy industries to recover materials in dilution. [ 13–22 ]…”

“…In PDDCs, baffles in the form of discs and doughnuts have been used, which help the extraction by improvement of the contact between two immiscible liquids, and the pulses in this column cause better breaking of droplet and improve the mass transfer. [ 19,26,27 ]…”

Effect of Scale-Up on Residence Time and Uranium Extraction on Annular Centrifugal Contactors (ACCs)

“…The modelling developments will lead to improvements in the following ways. CFD modelling to understand hydrodynamic behaviour and process modelling improvements will allow for a more accurate simulation of the mass transfer and the simulation of chemical reactions that occur inside the ACC on timescales that are similar to the residence times in the ACC [7,[33][34][35][36][37][38].…”