Hanee F. Hizaddin

Separation of BTEX aromatics from n-octane using a (tetrabutylammonium bromide + sulfolane) deep eutectic solvent – experiments and COSMO-RS prediction

Separation of aromatics from aliphatics is a challenging process because of the close range of their boiling points and the formation of several combinations of azeotropes. Until now, no feasible separation process is available for aromatic concentrations below 20 wt%. In this work, we have investigated the possibility of using a selected deep eutectic solvent (DES) for the liquid–liquid extraction of benzene, toluene, ethylbenzene and m-xylene (BTEX) aromatics. The DES used in this work was synthesized by combining tetrabutylammonium salt and sulfolane. Equilibrium data for the ternary system consisting of BTEX aromatics, n-octane and DES were measured at 25 °C and atmospheric pressure. The results showed that the used DESs have comparable distribution ratios and selectivities to those of commercial solvents. In all tested systems, sulfolane was not present in the hydrocarbon layer. It was also found that the selectivity decreases with decreasing polarity of the aromatic compound. The Non-Random Two Liquid (NRTL) model was successfully used to correlate the experimental tie-lines and to calculate the phase compositions of the ternary systems. In addition, the performance of COSMO-RS to predict the ternary tie-lines for the studied systems was evaluated and the σ-profiles were used to explain the interaction between the DES and the aromatic compounds.

Determination of cost-effective operating condition for CO2 capturing using 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid

Abstract1-Butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) ionic liquid (IL) is considered for CO2 capturing in a typical absorption/stripper process. The use of ionic liquids is considered to be cost-effective because it requires less energy for solvent recovery compared to other conventional processes. A mathematical model was developed for the process based on Peng-Robinson (PR) equation of state (EoS). The model was validated with experimental data for CO2 solubility in [BMIM][BF4]. The model is utilized to study the sorbent effect and energy demand for selected operating pressure at specific CO2 capturing rates. The energy demand is expressed by the vapor-liquid equilibrium temperature necessary to remove the captured CO2 from the spent solvent in the regeneration step. It is found that low recovery temperature can be achieved at specific pressure combination for the absorber/stripper units. In fact, the temperature requirement is less than that required by the typical monoethanolamine (MEA) solvent. The effect of the CO2 loading in the sorbent stream on the process performance is also examined.

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

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.

Ethylsulphate-Based Ionic Liquids in the Liquid–Liquid Extraction of Pyrrole and Pyridine from Isododecane at 298.15 K

Abstract Ternary liquid-liquid equilibria for four systems containing ionic liquids {1-ethyl-3-methylimidazolium ethylsulphate ([EMIM][EtSO4]) and 1-ethyl-3-methylpyridinium ethylsulphate ([EMPY][EtSO4])}(1)+pyrrole/pyridine(2)+isododecane (3) have been determined at 298.15 K. The solute distribution coefficient and selectivity were calculated from experimental LLE data. All systems showed high distribution coefficient and selectivity values at the entire range of pyrrole or pyridine in feed. The consistency of experimental data was ascertained by applying the Othmer-Tobias and hand equations. Furthermore, the experimental LLE data have been compared and correlated using COSMO-RS, NRTL and UNIQUAC models. The influence of aromatic structure without inside ring of cation has a significant role on denitrification process at 298.15 K.