Extraction of aromatics from naphtha reformate using propylene carbonate

The phase equilibria of the extraction of aromatics from naphtha reformate with propylene carbonate as solvent has been studied. The phase equilibria data of paraffin/aromatic/propylene carbonate ternary systems available in literature along with data for the systems, cyclohexane/toluene/propylene carbonate and isooctane/ethyl benzene/propylene carbonate, generated in this study have been used to determine the interaction parameters of the following groups with propylene carbonate: CH2, ACH and ACCH(2). The aromatics in the naphtha reformate were extracted at different temperatures (ranging from 303 to 333 K) and different solvent to feed molar ratios (ranging from 1.0 to 3.0). The experimental results obtained were found to compare favorably with those obtained by the UNIFAC model using the interaction parameters determined. The yield, solvent power and processing index along with solvent selectivity and capacity for aromatic extraction from the reformate can also be predicted successfully using the interaction parameters generated in this study. The operating conditions leading to maximum aromatic recovery have been optimized. (C) 2003 Elsevier B.V. All rights reserved.