Abstract:To study the effects
of type and content of cosolvent as well as
temperature on the properties of two well-known deep eutectic solvents
(DESs), i.e., ChCl/EG (choline chloride + ethylene glycol at a molar
ratio of 1:2) and ChCl/Gly (choline chloride and glycerol at a molar
ratio of 1:2), the density and viscosity of the mixtures of ChCl/EG
or ChCl/Gly with methanol (MeOH) and water (H2O) over the
whole compositional range at temperatures from 288.15 to 323.15 K
as well as the molar enthalpy of mixing for the m… Show more
“…This is evident from the sharp steep in negative slope of viscosity profile in Fig. 12 and it is in agreement with the findings of similar work in this regard [ 29 , 32 ]. For example, a decrease of 20.7% in viscosity was achieved with 20% EtOH addition while the drop in viscosity at 50% EtOH is 30.17%.…”
Section: Resultssupporting
confidence: 93%
“…On the other hand, the refractive index shows almost constant values with increasing volume % of EtOH in the hybrid solvent. Similar findings have been reported in the literature [ 29 , 40 ]. Fig.…”
Section: Resultssupporting
confidence: 92%
“…In this regard, several studies have been conducted to mitigate the viscosity of DESs by blending with organic solvents. Some of the organic solvents explored include methanol [ 29 ], ethanol [ 30 , 31 ], dimethyl sulfoxide [ 32 ]. The considerably lower viscosities of the organic solvents in comparison with DESs or ionic liquids (ILs) suggest that the former should have a thinning effect on the latter.…”
Deep eutectic solvents (DESs) have high viscosities, but known to be mitigated by addition of suitable co-solvent. The effect of such co-solvent on the extraction efficiency of the hybrid solvent is hardly known. This study examined the effect of ethanol on three choline chloride-based DESs (glyceline, reline, and ethaline) by mixing each in turn with ethanol in various volume proportions. The hybrid solvents were evaluated for the extraction of benzene from n-hexane. Pseudo-ternary liquid–liquid equilibrium data were obtained using the refractive index method at 303 K and 1 atm for the systems, n-hexane (1) + benzene (2) + hybrid solvent (glyceline/ethanol, ethaline/ethanol, reline/ethanol) (3), and used to evaluate distribution coefficient (D) and selectivity (S). Furthermore, the physicochemical properties of the hybrid solvents were also determined. The results indicate increase in selectivity with increasing ethanol addition up to 50% and decrease with further addition. All hybrid solvents with 50% ethanol outperform sulfolane and are suitable replacement for same as green and sustainable extractant for aromatics from aliphatics. The glyceline + 50% ethanol emerged the overall best with 49.73% elevation in selectivity and 41.15% reduction in viscosity relative to the neat glyceline. The finding of this study is expected to fillip the drive for paradigm shift in petrochemical industries.
“…This is evident from the sharp steep in negative slope of viscosity profile in Fig. 12 and it is in agreement with the findings of similar work in this regard [ 29 , 32 ]. For example, a decrease of 20.7% in viscosity was achieved with 20% EtOH addition while the drop in viscosity at 50% EtOH is 30.17%.…”
Section: Resultssupporting
confidence: 93%
“…On the other hand, the refractive index shows almost constant values with increasing volume % of EtOH in the hybrid solvent. Similar findings have been reported in the literature [ 29 , 40 ]. Fig.…”
Section: Resultssupporting
confidence: 92%
“…In this regard, several studies have been conducted to mitigate the viscosity of DESs by blending with organic solvents. Some of the organic solvents explored include methanol [ 29 ], ethanol [ 30 , 31 ], dimethyl sulfoxide [ 32 ]. The considerably lower viscosities of the organic solvents in comparison with DESs or ionic liquids (ILs) suggest that the former should have a thinning effect on the latter.…”
Deep eutectic solvents (DESs) have high viscosities, but known to be mitigated by addition of suitable co-solvent. The effect of such co-solvent on the extraction efficiency of the hybrid solvent is hardly known. This study examined the effect of ethanol on three choline chloride-based DESs (glyceline, reline, and ethaline) by mixing each in turn with ethanol in various volume proportions. The hybrid solvents were evaluated for the extraction of benzene from n-hexane. Pseudo-ternary liquid–liquid equilibrium data were obtained using the refractive index method at 303 K and 1 atm for the systems, n-hexane (1) + benzene (2) + hybrid solvent (glyceline/ethanol, ethaline/ethanol, reline/ethanol) (3), and used to evaluate distribution coefficient (D) and selectivity (S). Furthermore, the physicochemical properties of the hybrid solvents were also determined. The results indicate increase in selectivity with increasing ethanol addition up to 50% and decrease with further addition. All hybrid solvents with 50% ethanol outperform sulfolane and are suitable replacement for same as green and sustainable extractant for aromatics from aliphatics. The glyceline + 50% ethanol emerged the overall best with 49.73% elevation in selectivity and 41.15% reduction in viscosity relative to the neat glyceline. The finding of this study is expected to fillip the drive for paradigm shift in petrochemical industries.
“…Furthermore, the investigation of the viscosity behavior of DESs with conventional solvents, such as alcohols, provides clues on the hydrogen bond changes. Up to now, only a few limited studies [ 16 , 17 , 18 , 19 ] have been devoted to the viscosity behavior of DESs mixtures with alcohols.…”
Section: Introductionmentioning
confidence: 99%
“…In the present year, Wang et al investigated the two well-known choline chloride based DESs of ChCl:ethylene glycol and ChCl:glycerol at the molar ratio of 1:2 in mixtures with methanol within the temperature range of 288.15–323.15 K. According to the measured data, they also calculated excess molar volumes, viscosity deviations, and excess molar Gibbs energies of activation for the investigated systems. They reported negative values for excess volumes, as well as negative viscosity deviations at all of the investigated temperatures and compositions [ 19 ]. Recently, Jangir et al investigated the viscosity behavior of the ChCl:lactic acid (1:2) DES in mixture with ethanol or ethylene glycol.…”
In this study, the viscosity behavior of two mixtures of Ethaline (1 ChCl:2 ethylene glycol) with either methanol or ethanol were investigated over the temperature range of 283.15–333.15 K at atmospheric pressure. The measured viscosities of neat Ethaline, methanol, and ethanol showed reliable agreement with the corresponding reported literature values. The mixture viscosities were modeled by an Arrhenius-like model to determine the behavior of viscosity with respect to temperature. The data were also modeled by the four well-known mixture viscosity models of Grunberg–Nissan, Jouyban–Acree, McAllister, and Preferential Solvation. All of the model results were reliable, with the Jouyban–Acree and Preferential Solvation models showing the most accurate agreement with the experimental measurements. The Jones–Dole viscosity model was also investigated for the measured viscosities, and by analyzing the results of this model, strong interactions among Ethaline and the alcohol molecules were proposed for both systems. As a final analysis, viscosity deviations of the investigated systems were calculated to study the deviations of the viscosity behaviors with respect to ideal behavior. Both systems showed negative viscosity deviations at all of the investigated temperatures, with the negative values tending towards zero, and hence more ideal behavior, with increasing temperatures. Moreover, in order to correlate the calculated viscosity deviations, the Redlich–Kister model was successfully used for both systems and at each investigated temperature.
Aiming at the problems of heavy environmental pollution, high energy consumption, and process complexity for current degumming techniques, three types of deep eutectic solvent (DES) systems as eco‐friendly sustainable solutions including choline chloride/urea (CU), ethylenediamine hydrochloride/ethylene glycol (EE) and choline chloride/imidazole (CI) were prepared and applied to the degumming of seed hemp. It was clearly showed that all three DES systems exhibit excellent degumming efficiency on seed hemp to remove noncellulosic components involving in pectin, hemicellulose, and lignin in amorphous region without damage to the structure and crystalline morphology of cellulose, leading to an increase of cellulose portion from 54% to about 80%. CI with the molar ratio of 3:8 at 175°C for 2.5 h give the best removal performance for hemicellulose and pectin while EE with molar ratio of 1:2 at 175°C for 3 h can remove lignin with highest efficiency. However, CU with the lowest cost reveals a balanced removal of three noncellulosic components, which may be the optimal choice for industrial production. Furthermore, density functional theory analysis disclosed the essential information of configuration stability for three DES systems.
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