Comparison of Deep Eutectic Solvents and Organic Solvent Effects on the Separation of Ternary Azeotropes by the Experimental Study and Molecular Simulation

Abstract

Extractive distillation is often used to separate difficult separation systems so as to realize the recovery and utilization of resources in industry. Based on the separation of ethylene glycol (EG), isoamyl alcohol, and water, the separation of ternary azeotropic mixtures by extractive distillation was studied. The study of extraction mechanism is very important for solvent screening and molecular design. To compare the selectivity of solvents, the interaction energies between solvent–water, solvent–EG, and solvent–isoamyl alcohol were calculated by the quantum chemical method. Atoms in molecules, reduced density gradient, and electrostatic potential were used to study the microextraction mechanism of solvents in the water–EG–isoamyl alcohol system. In extractive distillation, vapor–liquid equilibrium (VLE) data is used as the basic data for designing and optimizing the process. In order to solve the problem of lack of VLE data between N,N-dimethylformamide, dimethyl sulfoxide, choline-based deep eutectic solvents, and azeotropes, the VLE experiment of the solvent and azeotrope system was carried out. In this work, the selectivity of different solvents was compared by the quantum chemical method, the microextraction mechanism of solvents was explored, and the lack of VLE experimental data was supplemented, which provided theoretical guidance for the selection and design of solvent molecules with excellent performance.

Phase Equilibrium of p-Xylene and Isobutanol in Ionic Liquid Separations: Thermodynamic and Mechanistic Analysis

“…The intensity of electrostatic potential (ESP) on the molecules was determined, which can reflect the action site of the substance during the extraction process . The interaction region indicator − ­(IRI) can reflect the interaction forces existing between molecules. The behavior of intermolecular interactions of molecules can be determined as reflected by their electron density .…”

Experimental and Modeling Study for the Salting-Out Extraction of Acetic Acid from Aqueous Solutions with Kerosene

“…The liquid–liquid equilibrium studies provide the required knowledge about the level of miscibility, solute distribution coefficient, and selectivity of a solvent. Further, the investigation of the binary interactions of the involved phases verifies the selection of a suitable solvent …”

“…Further, the investigation of the binary interactions of the involved phases verifies the selection of a suitable solvent. 8 The study of the liquid−liquid equilibrium (LLE) of chemical systems involving a petroleum product has been of interest in many research studies. In our previous study, 9 the capability of kerosene for separating acetic acid from pure aqueous solutions was confirmed by comparing it with alcohol, ether, and ionic liquid solvents.…”

Rational Screening of Deep Eutectic Solvents for the Direct Extraction of α-Tocopherol from Deodorized Distillates

“…Very recently, Qin et al carried out a comparative screening of organic solvents and ILs for the extraction of α-tocopherol from methyl linoleate, proving that the best IL candidate can extract α-tocopherol more effectively than the best organic solvent candidate . However, the practical application of ILs for such an extraction task is potentially hindered by their complex preparation, high cost, poor biocompatibility, and biodegradability. − …”