Salting-out effect of sodium carbonate on the liquid–liquid equilibrium of (Water + Dichloromethane + N,N-Dimethylacetamide) system at temperature T=(298.15 and 308.15) K

The salting-out effect of sodium carbonate (Na₂CO₃) on the liquid–liquid equilibrium (LLE) of the ternary system of {water + dichloromethane + N,N-dimethylacetamide (DMAC)} was studied at temperature T = (298.15 and 308.15) K and atmospheric pressure. The generated data for salt-free system have been used to estimate the binary interaction parameters for the nonrandom two-liquid (NRTL) activity coefficient model. The mass fraction of the added salt is 2% or 5% of the initial water. Adding a 0.02 mass fraction Na₂CO₃ leads to an average enhancement of about 147% in distribution coefficient of DMAC between two phases, and it reaches to about 227% by adding 0.05 mass fraction of the salt. Isoactivity condition, the binary subsystems consistency and the tie-lines consistency have been verified in this paper and the K-value method is used for LLE data correlation. The root-mean-square deviation of the system was calculated in order to detect the correlation and accuracy of the NRTL model.     

Liquid-liquid equilibrium for the ternary systems of solvents+water+propionic acid at 25 ‡C and atmospheric pressure

Liquid-liquid equilibrium data for the ternary systems of toluene+water+propionic acid, o-xylene+water +propionic acid, methyl isobutyl ketone+water+propionic acid, ethyl acetate+water+propionic acid, and 1-butanol +water+propionic acid were measured at 25 ‡C and atmospheric pressure. The reliability of the experimental tie-line data was ascertained by means of the Othmer-Tobias, Bachman-Brown, and Hand correlations. For the extraction effectiveness of solvents, the distribution and selectivity curves were plotted. In addition, these experimental tie-line data were also correlated with NRTL and UNIQUAC models.     

Phase Equilibria of the Ternary System Water + Propionic Acid + 2-Butanol

Abstract

Liquid–liquid equilibria for the ternary system water + propionic acid + 2-butanol was measured over a temperature range of 298 to 318 K. The results were used to estimate the interaction parameters between each of the three compounds for the nonrandom, two liquid (NRTL) equilibrium model as a function of temperature. The estimated interaction parameters were successfully used to predict the equilibrium compositions by the NRTL model. Based on this work, the distribution coefficients were also calculated and compared with the experimental values.     

Tie-line data for aqueous mixtures of butyric acid with isobutyl acetate at various temperatures

Experimental liquid-liquid equilibrium (LLE) data for the system of (water+butyric acid+iso-butyl acetate) were obtained at T=(298.2, 303.2, 308.2, and 313.2) K and atmospheric pressure. This ternary system exhibits type-1 behavior of LLE. The experimental tie-line data were correlated using the UNIQUAC and NRTL models. The reliability of the experimental tie-line data was determined by applying the Othmer-Tobias and Hand correlations. Distribution coefficients and separation factors were calculated over the immiscibility regions.     

Liquid-liquid equilibria for water+2,3-butanediol+1-pentanol ternary system at different temperatures of 298.2, 308.2, and 318.2 K

Liquid-liquid equilibrium (LLE) data was measured for the water+2,3-butanediol+1-pentanol ternary system at 298.2, 308.2, and 318.2 K under atmospheric pressure. Binodal solubility curves and complete ternary phase diagrams were experimentally obtained in mass fraction at these three different temperatures. The consistency of the tieline results was verified by using Othmer-Tobias and Hand plots. Distribution coefficients and separation factors of 2,3- butanediol were evaluated for each tie-line, and the effect of temperature was also investigated. It was found that the distribution coefficients and separation factors of 2,3-butanediol increased with temperature. The experimental LLE data were correlated by the UNIQUAC and NRTL models, and the binary interaction parameters calculated from these models have been reported. Both models successfully predict the experimental tie-line data within average root-mean-square deviations (RMSD) being less than 1.38% and 1.49% from the UNIQUAC and NRTL models, respectively.     

Investigation of liquid–liquid equilibrium of the ternary system(water +1,6-diaminohexane + 2-methyl-1-propanol or 3-methyl-1-butanol) at different temperatures

In this study, the LLE data of ternary system (water+1,6-diaminohexane+2-methyl-1-propanol) and (water+1,6-diaminohexane+3-methyl-1-butanol) were measured at 293.15, 303.15 and 313.15 K under atmospheric pressure. Reliability of the experimental tie-line data was checked by empirical Hand, Othmer-Tobias and Bachman equations. Distribution coefficient (D) and selectivity (S) were calculated in order to investigate capability of the studied organic solvents for 1,6-diaminohexane extraction. The high values of separation factors demonstrated that 2-methyl-1-propanol and 3-methyl-1-butanol were applicable for this purpose. The experimental data were correlated by nonrandom two-liquid (NRTL) and universal quasi-chemical (UNIQUAC) models. The percent-root-mean-square deviation (RMSD) values for NRTL and UNIQUAC models were less than 0.15, which indicated that the experimental data have been sufficiently correlated.     

SOLUBILITY AND TIE-LINE DATA FOR WATER + FORMIC ACID + METHYL ISOBUTYL KETONE TERNARY SYSTEM AT DIFFERENT TEMPERATURES

The solubility and tie-line data of the ternary system comprising water, formic acid, and methyl isobutyl ketone were experimentally determined at the temperatures 288.15, 298.15, and 308.15 K, and atmospheric pressure 101.3 kPa. The plait points were also determined using Treybal's method. The results indicate that formic acid distributes preferentially in MIBK compared to water. Experimental tie-line data were regressed with the NRTL model to obtain binary interaction parameters. It is found that the NRTL model correlates the present system satisfactorily with average root-mean-square deviation of 0.34%.     

Measurements and thermodynamic modeling of liquid–liquid equilibria in ternary system 2-methoxy-2-methylpropane+p-cresol+water

Liquid–liquid equilibrium(LLE)data for the ternary system 2-methoxy-2-methylpropane(methyl tert-butyl ether)+ p-cresol + water was measured at atmospheric pressure and temperatures of 298.15 K and 313.15 K.From the distribution coefficients and selectivity,it was found that 2-methoxy-2-methylpropane is an efficient solvent to extract p-cresol from wastewater.The consistency of the experimental tie-line data was verified with the Hand and Bachman equations.These data were also correlated with the non-random two liquid(NRTL)and universal quasi-chemical correlation activity coefficient(UNIQUAC)models to yield binary interaction parameters for p-cresol extraction process evaluation.Both models agreed with experiments very well,yet the NRTL model showed even smaller average deviation than the UNIQUAC model.     

Semi-Empirical Modeling of Gas–Liquid Mass Transfer in Gas–Liquid–Liquid Systems in Stirred Tanks

Two semi-empirical models of gas–liquid mass transfer in gas–liquid–liquid systems are presented, one for the case where the dispersed liquid phase has a positive spreading coefficient S > 0, the other for S < 0. The models are based on mathematical expressions inspired by assumed mass transfer mechanisms, which are different depending on the oil spreading characteristics. Model simulations compare well with experimental data (up to oil phase holdup ? ～ 0.1), managing to simulate the shape of the experimental curves of oxygen mass transfer enhancement factor E vs. ? for the air–water–heptane (S > 0) and air–water–dodecane (S < 0) systems, better than other models available in the literature.     

Determination and Correlation of Liquid–Solid Phase Behaviors of Polyhydric Alcohol + KBr + H2O Ternary Systems at 288.15, 298.15, and 308.15 K

The solubility, density, and refractive index of 1,2-propanediol + KBr + H₂O, ethylene glycol + KBr + H₂O, and glycerin + KBr + H₂O ternary systems are determined at 288.15, 298.15, and 308.15 K. In all cases, the solubility of KBr decreases with increasing concentration of polyhydric alcohol. The liquid–solid equilibrium experimental data are correlated using the nonrandom two-liquid (NRTL) activity coefficient model, considering nondissociation of the dissolved salt in the liquid phase, and new interaction parameters are estimated. The mean deviations show a good applicability of the NRTL model. Simultaneously, the corresponding unsaturated systems are investigated, and the concentration factors are discussed.     

Isobaric Vapor-Liquid-Liquid Equilibria for 1-Butanol + Water + 2,3-Butanediol at 101.3 kPa

Vapor-liquid-liquid equilibria (VLLE) data were determined for the ternary system 1-butanol + water + 2,3-butanediol at 101.3 kPa. A binary heterogeneous minimum boiling azeotrope was found at 365.95 K with mass fractions of 0.526 and 0.474 for 1-butanol and water, respectively. A modified UNIQUAC model was used to predict VLLE by using experimental data, including VLE of 1-butanol + 2,3-butanediol, VLE of water + 2,3-butanediol, LLE of 1-butanol + water, and one LLE tie-line of 1-butanol + water + 2,3-butanediol. The experimental data were compared with the calculated values. The absolute average relative deviations (AARD) are 1.65%, 1.72%, and 2.22% for organic liquid phase, aqueous liquid phase, and vapor phase, respectively. It demonstrates an appropriate fit of the modified UNIQUAC model.     

VAPOR-LIQUID EQUILIBRIA OF TOLUENE + n-BUTANOL AND TOLUENE + n-BUTANOL + CALCIUM CHLORIDE AT 94.0kPa

Vapor-liquid equilibrium data of toluene + n-butanol and toluene+ n-butanol + CaCl₂ (at saturation) were measured at a pressure of 94.0 kPa, using a modified Malanowski equilibrium still. The salt investigated in this work, i.e., CaCl₂, exhibits a slight salting-out effect on toluene. The experimental results of the salt-free binary were compared with those obtained from NRTL, ASOG, and UNIFAC models. The latter two models predicted the bubble-point temperatures within 0.5 K (as a root mean square deviation, RMSD) whereas the NRTL model, which was employed to establish thermodynamic consistency by directly fitting the experimental data, correlated the bubble-point temperatures with an RMSD of 0.2 K. On the other hand, the experimental data of toluene+n-butanol+CaCl₂ were compared with those predicted by the NRTL-Tan model for the effect of the electrolyte. This model predicted the bubble-point temperatures with an RMSD of 0.5 K. Calcium chloride has been shown not to have a sensible effect on the azeotropic composition.     

Liquid–Liquid Equilibrium for Systems Containing Epoxidized Oils,Formic Acid,and Water: Experimental and Modeling

Epoxidized oils are eco-friendly plasticizers, which are industrially produced through the epoxidation reaction in a formic acid-hydrogen peroxide autocatalyzed system. The fundamental knowledge to describe the phase equilibrium of systems after epoxidation reaction is lacking, which is crucial for the design of the purification facilities. This work reported experimental data for the liquid–liquid equilibrium of three systems, i.e., epoxidized fatty acid methyl esters + formic acid + water, epoxidized fatty acid 2-ethylhexyl esters + formic acid + water, and epoxidized soybean oil + formic acid + water, in the temperature range (303.15–348.15) K under atmospheric pressure. The results indicated that the liquid–liquid equilibrium constant of formic acid in the systems followed the order of epoxidized fatty acid 2-ethylhexyl esters > epoxidized fatty acid methyl esters > epoxidized soybean oil. Moreover, the obtained experimental data were correlated using nonrandom two liquid (NRTL) and universal quasi chemical (UNIQUAC) models. The maximum root mean square deviation (RMSD) values as low as 0.0052 and 0.0263 were estimated using the NRTL and UNIQUAC model, respectively. The NRTL model is more suitable than the UNIQUAC model to describe the liquid–liquid equilibrium behavior of these ternary systems.     

The thermodynamics and separation process design for the ternary system 1,3-propanediol + 1,3-butanediol + 2,3-butanediol

ABSTRACT

The isobaric vapor–liquid equilibrium (VLE) data at 101.3kPa for (1,3-propanediol(PG) + 1,3-butanediol(BD)), (1,3-PG+2,3-BD) and (1,3-BD+2,3-BD) and for the ternary system of (1,3-PG+1,3-BD+2,3-BD) have been measured. The thermodynamic properties of the non-ideal vapor phase have been considered with the EOS equation. The liquid activity coefficients have been calculated with Wilson, NRTL and UNIQUAC equations, and the binary interaction parameters were regressed by these models. The vapor composition of VLE data were calculated by the optimum parameter group and generated a good consistency to experimental values. Based on all the preceding results, a two-column distillation process was designed.     

Associating lattice cluster theory and application to modeling oleic acid + formic acid + formoxystearic acid

The associating lattice cluster theory (ALCT) is developed in this work. It is especially useful for describing mixtures of oligomers of varying architecture. As the influence of the structure is predicted, it can also be applied in cases in which pure component data are lacking. ALCT is used here for the calculation of liquid–liquid equilibria (LLE) in the system oleic acid (OA) + formic acid (FA) + formoxystearic acid that is interesting for biopolymer production. Experimental studies of LLE in that system were carried out at 296, 313, and 333 K. Ternary mixtures were prepared from the educts OA and FA using heterogeneous acidic catalysis. Quantitative NMR spectroscopy was applied for the analysis. For the educt system also the excess enthalpy was studied by isothermal titration calorimetry. The prediction of the ternary LLE by ALCT succeeds. © 2018 American Institute of Chemical Engineers AIChE J, 65: 783–791, 2019     

Effect of pH on Properties of Poly(Vinyl Pyrrolidone) + Tri-Sodium Citrate + Guanidine Hydrochloride Aqueous Two-Phase Systems

The experimental results for liquid–liquid equilibrium of poly(vinyl pyrrolidone) (K30) + tri-sodium citrate + guanidine hydrochloride (5 and 10 w/w%) aqueous two-phase system at 25°C and different pH values (6.2, 7.4, and 10.0) were studied. The partition behavior of guanidine hydrochloride is known to be a function of several factors. Some of them such as guanidine hydrochloride concentration, pH, polymer/salt ratio (w/w), size, and slant of the tie-lines (STLs) are investigated in this study. At higher guanidine hydrochloride concentrations, the binodal was observed to displace. The behavior of the tie-line size (TLS) seems to be somehow different from the influence of the polymeric phase. The increase of GuHCl concentration decreased the STLs, but the slant and size of the equilibrium tie-lines increased with the pH of the two-phase system. The viscosity (η), density (ρ), electrical conductivity (k), and refractive index (n_D) of the poly(vinyl pyrrolidone) (K30) + tri-sodium citrate + guanidine hydrochloride + water two-phase systems versus pH were investigated. It was observed that the viscosity and density of the aqueous two-phase system is influenced by the TLS. The density changes between the phases (Δρ) and viscosity changes of the phases (Δη) increased with the increase of the TLS. It was found that linear relations exist between the TLS and the interphase density and viscosity changes.     

Liquid+liquid equilibria of ternary water+carboxylic acid+solvent systems at 288.15 K

The experimental liquid-liquid equilibrium (LLE) data for six ternary systems containing (chloroform+propionic acid+water), (chloroform+acetic acid+water), (diethyl ether+propionic acid+water), (diethyl ether+acetic acid+water), (trichloroethylene+propionic acid+water) and (trichloroethylene+acetic acid+water) were measured at 288.15 K and at atmospheric pressure. An accurate and simple titration method was used for determining of the concentration of carboxylic acid in the both liquid phases at equilibrium. The reliability of the experimental tie-line data was confirmed by using the Othmer-Tobias correlation. The distribution coefficients and selectivity factors were presented to evaluate the efficiency of the solvents for extraction of carboxylic acid from water. The results show that chloroform and diethyl ether are satisfactory solvents for extraction of carboxylic acids from water. Trichloroethylene separates propionic acid from water; however, it cannot be used as a solvent for separation of acetic acid.     

Effective separation of aromatic hydrocarbons by pyridine‐based deep eutectic solvents

Many promising qualities of deep‐eutectic solvents made them suitable solvents in separation process. In this work, the pyridine‐based deep eutectic solvents were designed and synthesized with N‐ethylpyridinium bromide and two HBDs (N‐formyl morpholine and levulinic acid). Two ternary systems, benzene + cyclohexane + DES and toluene + n‐heptane + DES, were studied by the liquid‐liquid extraction. The effect of different HBDs, extraction time, volume ratio of DES to system solution, and the initial concentration of aromatic were studied. The DES with N‐formyl morpholine showed better separation performance than that with levulinic acid. The liquid‐liquid extraction equilibrium could be obtained in 10 minutes. The volume ratio of DES to system solution was set as 1:1. Both DESs showed their best separation performance at low temperatures (20°C) and low aromatic concentration system. For the benzene + cyclohexane system, the distribution coefficient of benzene was 1.733 and the selectivity was 23.8 at 20°C. For the toluene + n‐heptane system, the distribution coefficient of toluene was 0.853 and the selectivity was 40.7. Tie‐lines for two ternary systems were obtained, and the Othmer‐Tobias correlation was used to check the reliability of the obtained liquid‐liquid extraction experimental data. The experimental LLE data were correlated using the NRTL model and the calculated data correlated significantly with the experimental data.     

Liquid-liquid equilibria of water + methanol + (MTBE or TAME) mixtures

Experimental liquid-liquid equilibrium data obtained at various temperatures for water + methanol + methyl tert-butyl ether and water + methanol + tert-amyl methyl ether were satisfactorily fitted by both NRTL and UNIQUAC models using S?rensen's well-known correlation program, which nevertheless performed anomalously when run seeking minimum error in the solute distribution ratio.     

Response surface methodology for optimization and determination of Riluzole by microfunnel magnetic stirring-assisted liquid–liquid microextraction coupled with high-performance liquid chromatography

ABSTRACT

A rapid, simple, and highly sensitive microfunnel magnetic stirring-assisted liquid–liquid microextraction coupled with HPLC was developed for determination of Riluzole (RLZ). The main extraction parameters were screened using the Plackett–Burman design and optimized by central composite design. Under optimum conditions, the calibration curve was linear over the range of 0.2–400 ng mL^?1, and RSD of 3.21% (n = 14, 20 ng mL^?1) proved to have good reproducibility. The detection limit was 0.023 ng mL^?1 and 1.5 ng mL^?1 for aqueous and biological samples, respectively. The tap water, human plasma, and urine samples showed excellent recoveries for RLZ (97.09–101.92%) via this method.