Liquid–Liquid Equilibrium of Alcohol–Ester Systems with Deep Eutectic Solvents Based on Choline Chloride and Alkanediols (Ethylene Glycol or Propylene Glycol)

Abstract

Deep eutectic solvents (DESs) formed by choline chloride and ethylene glycol or propylene glycol were tested for the separation of azeotropic mixtures containing alcohols (ethanol, n-propanol, and n-butanol) and acetates. For this purpose, the experimental data of coexisting liquid phases were obtained at temperatures 293.15 and 313.15 K and atmospheric pressure. Liquid–liquid equilibrium compositions were determined by 1H NMR spectroscopy and further analyzed. Additionally, liquid density and dynamic viscosity for DESs studied in the temperature range of 293.15–323.15 K and atmospheric pressure were measured. The separation efficiency of DESs was characterized by distribution coefficients and selectivity values for alcohol. Comparison of selectivity values in systems containing alcohols and esters with other DESs consisting of choline chloride and various hydrogen-bond donors (malonic acid, glutaric acid, glycerol, and urea) was carried out. A local composition model (NRTL) was used for liquid–liquid equilibria data correlation, which provided rather good estimates for the selectivity values.

Mechanistic Investigation of Isobutanol/Isobutyl Acetate Separation by Extraction Using Low-Transition Temperature Mixtures

“…The NRTL and UNIQUAC models have a wider range of applications and can be used to correlate phase equilibrium data of both miscible and immiscible systems. It has been reported that the NRTL model yields good fitting results for systems containing ionic liquids or LTTMs. , Therefore, in this work, the NRTL model is used to correlate the experimental data in order to obtain the interaction parameters between binary components in the system. The objective function (OF) for fitting the experimental data is defined as the minimum deviation between the experimental values and the fitted values at each composition point on the experimental tie-line.…”

Study of the Liquid–Liquid Equilibrium and Extraction Properties of Deep Eutectic Solvents Based on Choline Chloride for the Separation of the Ethanol–Ethyl Formate System for Potential Use in Biofuel Production

“…Dependence of selectivity ( S ) on the ethanol mass fraction ( w ) at 313.15 K and 101.3 kPa for the pseudoternary systems: ethanol–ethyl formate–DES (ChCl/Glblue solid circles, ChCl/Urred solid circles, ChCl/Gluolive solid circles, ChCl/EGcyan solid circles); ethanol–ethyl acetate–DES (ChCl/Glblue open down triangles, ChCl/Urred open down triangles, ChCl/Gluolive open down triangles, ChCl/EGcyan open down triangles); ethanol–ethyl propionate–DES (ChCl/Glblue open rectangle, ChCl/Urred open rectangle, ChCl/Gluolive open rectangle).…”

“…Comparison of the selectivity of the separation of the ethanol–ethyl formate–DES (ChCl/Glu), ethanol–ethyl acetate–DES (ChCl/Glu), and ethanol–ethyl propionate–DES (ChCl/Glu) are presented at Figure d. Figure e shows a comparison of selectivity in the ethanol–ethyl formate–DES (ChCl/EG) and ethanol–ethyl acetate–DES (ChCl/EG) systems. Comparisons of the data showed that there is a tendency for the alcohol–ether systems to increase the efficiency of separation with an increase of the length of the acyl chain in the ester in mixtures with the same alcohol content.…”

“…Viscosity data for DES formed by choline chloride and urea are shown in Figure S13. The Data on a comparative analysis for DES formed by choline chloride and ethylene glycol are presented in ref 27.…”

“…Data on a comparative analysis for DES formed by choline chloride and ethylene glycol are presented in ref .…”