On the volatility of aromatic hydrocarbons in ionic liquids: Vapor-liquid equilibrium measurements and theoretical analysis

Abstract

El acceso a la versión del editor puede requerir la suscripción del recurso Access to the published version may require subscription AbstractThe use of ionic liquids (ILs) as solvent in the liquid-liquid extraction of aromatic compounds is one of their most studied applications. Nevertheless, the recovery of the extracted hydrocarbons has been much less investigated, being a required task to complete the global separation process. Taking into account the negligible vapor pressure of the ILs, this step could be easily carried out by flash distillation, which requires the study of vapor-liquid equilibrium (VLE). In order to study this topic deeper, in this work a systematic analysis of the VLE and vapor-liquid-liquid equilibrium (VLLE) data for {aromatic hydrocarbon + IL} binary mixtures was carried out, from both an experimental and computational point of view. For that, new experimental VLE and VLLE data of 24 {toluene + IL} binary mixtures were

Stripping Columns to Regenerate Ionic Liquids and Selectively Recover Hydrocarbons Avoiding Vacuum Conditions

“…As can be seen in Figure 3, n-heptane is mainly recovered by distillate stream whereas toluene is separated by residue. A wide range of hydrocarbon recoveries (closely from 0 to 100 %) was obtained depending on IL structure, which may be related to the different aromatic/aliphatic selectivities determined by the aromatic/aliphatic-IL intermolecular interactions 58 To complement the analysis, the temperature achieved at the bottom of the stripping column (SC1) is depicted in Figure 4, displaying the temperature range from each representative IL family detailed above. As can be seen, a wide range of operating temperatures (100-175 ºC) is also obtained.…”

A review on physicochemical measurements by headspace gas chromatography. Studies of vapour-liquid equilibria.

“…The main advantages of the headspace analysis for the studies of vapour-liquid equilibrium stem from the possibility of simultaneous measurements of gas phase concentrations of all components of the studied multicomponent system and from the possibility of measurements automation. Therefore the headspace analysis has been widely employed to study the vapour-liquid equilibrium of both binary [16,[19][20][21][22][23][24] and ternary [18,22,23,[25][26][27] systems.…”

“…A special attention of researchers was focused on the effects of ionic liquids [24,25,27] and simple electrolytes [28][29][30][31][32] addition on the vapour-liquid equilibria, in search for improvement of separation of azeotropic mixtures by distillation. The objectives of selected headspace gas chromatographic studies of VLE, together with the details on the investigated systems are given in Table 1.…”

COSMO‐RS based ionic liquid screening for the separation of acetonitrile and ethanol azeotropic mixture

“…Group contribution methods (GCMs) are frequently applied to predict the thermodynamic properties of liquid-IL systems, such as activity coefficient, 17,18 solubility, 19 Henry coefficient, 20 selectivity, 21 phase equilibrium and so on. 22,23 However, the performance of the GCMs relies on the quality of the interaction parameters, and these methods are limited by the numbers of databases. The Conductorlike Screening Model for Real Solvents (COSMO-RS) [24][25][26] has been a popular alternative to GCMs due to its high efficiency and good predictive accuracy using fewer parameters for screening ILs.…”

“…Group contribution methods (GCMs) are frequently applied to predict the thermodynamic properties of liquid–IL systems, such as activity coefficient, solubility, Henry coefficient, selectivity, phase equilibrium and so on . However, the performance of the GCMs relies on the quality of the interaction parameters, and these methods are limited by the numbers of databases.…”