Isobaric Vapor–Liquid Equilibrium for the Binary Systems of <i>sec</i>-Butyl Acetate + <i>n</i>‑Butyl Alcohol, Isobutyl Alcohol, or <i>tert</i>-Butyl Alcohol at 101.3 kPa

The isobaric vapor–liquid equilibrium (VLE) data of <i>n</i>-butyl alcohol + SBAC, isobutyl alcohol + SBAC, and <i>tert</i>-butyl alcohol + SBAC binary systems were determined at 101.3 kPa by using an Ellis vapor liquid equilibrium still. The experimental data passed the thermodynamic consistency test by the Herington method and showed positive deviations from ideal behavior. The VLE values were correlated by the Wilson, nonrandom two-liquid (NRTL), and universal quasichemical (UNIQUAC) activity-coefficient models with satisfactory results. The results show that <i>n</i>-butyl alcohol + SBAC and isobutyl alcohol + SBAC systems form minimum temperature azeotropic mixtures

Screening Monoethanolamine As Solvent to Extract Phenols from Alkane

Coal tar is a byproduct of low temperature coal carbonization. The separation of the compounds has great significance since its main component is the mixture of phenols and hydrocarbons. In this paper, the separation of specific phenolic compounds from model coal tar (phenols + hexane) was studied. The solvent was screened by empirical analysis, the universal quasichemical functional group activity coefficient (UNIFAC), and conductor-like screening model COSMO-SAC (segment activity coefficient). COSMO-SAC was used to calculate the capacity, selectivity, and performance index of solvents. Finally, the monoethanolamine (MEA) was selected as the solvent to extract the phenols. The liquid–liquid equilibrium for the ternary mixture of phenols + hexane + MEA was measured at 303.15 K and 323.15 K under atmospheric pressure, and the results showed that MEA provided a high distribution coefficient, efficiency, and selectivity for phenols. Meanwhile, the extraction process of phenols was simulated based on the nonrandom two-liquid (NRTL) model, for which binary interaction parameters were obtained through calculations of phase equilibrium. The results showed that the purity of phenols can achieve more than 99.5 wt % using MEA as a solvent

Liquid–Liquid Extraction of Benzene and Cyclohexane Using Sulfolane-Based Low Transition Temperature Mixtures as Solvents: Experiments and Simulation

The separation of benzene and cyclohexane is considered to be one of the most challenging processes in the petrochemical industry. In this paper, low transition temperature mixtures (LTTMs) were used as solvents for the separation of benzene and cyclohexane. The selected LTTMs were sulfolane–tetrabutyl­ammonium bromide 5:1 and ethylene glycol–trimethyl­amine hydrochloride 5:1, and liquid–liquid equilibrium (LLE) data of benzene–cyclohexane–LTTMs were experimentally determined at 40 °C under a normal atmosphere. Moreover, the effects of the mole ratio of hydrogen bond donor (HBD) sulfolane and hydrogen bond acceptor (HBA) tetrabutyl­ammonium bromide on extraction performance were also observed based on the LLE data. It is found that, when the mole ratio of sulfolane to tetrabutylammonium bromide is 5:1, LTTM has the best extraction performance. In addition, the LLE data of the benzene–cyclohexane–LTTMs ternary system were used to fit parameters of the NRTL activity coefficient model. Based on the NRTL model the continuous extraction process was simulated and the operating parameters were obtained, and high product purity (cyclohexane 0.997) and high recovery efficiency (cyclohexane 93.28% and benzene 98.25%) can be achieved. In conclusion, the LTTM sulfolane–tetrabutyl­ammonium bromide 5:1 is a promising solvent for the extractive separation of benzene–cyclohexane mixtures