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

Abstract

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.

Effect of Structural Parameters on Drop Size Distribution in Pulsed Packed Columns

“…Liquid‐liquid extraction in pulsed columns is a frequently applied technique in chemical engineering, hydrometallurgy, nuclear technology, and other areas due to its high separation efficiency by reducing axial mixing and increasing drop breakup and coalescence rate 1–3, and by controlling the pulse intensity which improves the rate of mass transfer by size reduction of the drops 4. Mass transfer is a function of the interfacial area which can be calculated from drop size and holdup 5, 6.…”

Analysis of Different Pressure Thermally Coupled Extractive Distillation Column

“…Because the boiling points of propane and propylene are very close over a large range of pressure, it always needs a huge investment in equipment and much energy requirement to separate them by conventional distillation. Extractive distillation (ED), an important separation method in chemical engineering [3,4], is used to separate compounds with similar boiling points by using an additional entrainer to alter the relative volatility [5]. Liao et al [2] had used extractive distillation for the propane-propylene separation and achieved excellent purity of propylene.…”

Drop behaviour characteristics in different operating regimes in an L‐shaped pulsed sieve‐plate column

“…On the other hand, regarding to propose a correlation for prediction of the transition between regimes, a large number of investigations have been made and various correlations for regime transition in extraction columns are proposed . Moreover, the applicability of computational fluid dynamics (CFD) and population balance equation (PBE) has been investigated for the simulation of drop behaviour in the column in various studies …”