Mathematical modeling and parametric study of aromatics extraction from aliphatics with ionic liquids in a rotating disc extractor

Abstract

A mathematical model is introduced for the extractive separation of aromatic from aliphatic hydrocarbons in a counter current rotating disc contactor (RDC). The Mass conservation law is applied for toluene/n-heptane/solvent system to predict the concentration variation of toluene in continuous and dispersed phases along the column length. The obtained results are compared with the available experimental data of a pilot-scale contactor. This model is developed with two perspectives: with plug flow approach and with back mixing effects. The effect of parameters, like inlet solvent flow rate, rotor speed and extraction temperature on the contactor performance is studied. Disregarding back mixing effects for solvents with low viscosity leads to enormous errors in prediction of concentration profiles. An increase in the solvent flow rate and extraction temperature results in higher de-aromatization efficiency of extraction process while the rotor speed does not have noticeable consequence on the final performance of extraction column. © 2017 Elsevier Ltd. All rights reserved.