Separation of Pyrrole from Isododecane Using Imidazolium and Pyridinium Based Ionic Liquid at 298.15 K: Experiment and COSMO-RS Prediction

Abstract

The removal of aromatic nitrogen compound from diesel oil is important to produce cleaner fuel and reduce the environmental impact. Therefore, denitrification of diesel oil is carried out by liquid-liquid extraction at ambient and moderate condition. The aim of this work is to study liquid-liquid extraction (LLE) for the mixture of ionic liquids (ILs); 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM][EtSO₄]) and 1-ethyl-3-methylpyridinium ethylsulfate ([EMPy][EtSO₄], nitrogen compounds; pyrrole (PYR) and model diesel compound; isododecane (ISOD). The selectivity and solute distribution ratio values were calculated, four ternary diagrams were generated and denitrification efficiency was determined to evaluate the effectiveness of the extraction. The Conductor-like Screening Model for Real Solvents (COSMO-RS) model was used to predict the composition of the ternary systems. The experimental values and COSMO-RS prediction were then compared to determine the root-mean-square deviation (RMSD) for each system. The slope of tie lines is positive for all ternary system and the average RMSD is 2.825 %. The prediction gave RMSD of 1.12 % for [EMIM][EtSO₄](1) + Pyrrole(2) + Isodecane(3) system; 2.51 % for [EMPy][EtSO₄](1) + Pyrrole(2) + Isodecane(3) system.