Ternary Solid-liquid Phase Equilibrium Research Articles

Determination and molecular simulation of ternary solid–liquid phase equilibrium of succinic acid + maleic acid + water from 283.15 K to 333.15 K

This study used the isothermal saturation gravimetric method to examine the solid–liquid phase equilibrium relationships composed of succinic acid + maleic acid + water spanning from 283.15 K to 333.15 K. The experimental data were utilized for the purpose of plotting the equilibrium phase diagrams of ternary systems in the studied temperature range. There were three crystalline regions in each isothermal ternary phase diagram, two saturation boundary curves, and a co-saturation point. To broaden the use of data from binary and ternary phase equilibrium measurements, Wilson and NRTL models were utilized for correlation and expectation, while relative average deviation (RAD) and root mean square deviation (RMSD) were utilized to evaluate the computational exactness. The results show that the theoretically calculated values were found to be in near agreement with the experimental values, and both models were able to obtain more precise theoretical data under different experimental conditions. In addition, molecular simulation was employed to elucidate the interaction between succinic acid, maleic acid, and water. This study provides accurate and reliable data for the separation of succinic acid and maleic acid mixture in water. These findings can be utilized to make sense of the dissolvability conduct of succinic acid and maleic acid in aqueous solution.

Ternary solid–liquid phase equilibrium and phase diagram for DL-malic acid+fumaric acid+water system and molecular simulation

Solubility of DL-malic acid and fumaric acid in water for binary and ternary systems was determined through high-performance liquid chromatography (HPLC) at atmospheric pressure in this study. Six isothermal ternary phase diagrams were established at temperatures of 283.15, 293.15, 303.15, 313.15, 323.15, and 333.15 K. Every isothermal ternary phase diagram contains three crystalline regions (pure DL-malic acid, pure fumaric acid, and mixture of DL-malic acid and fumaric acid), two co-saturated boundary curves, and one invariant co-saturated point. All diagrams show that the crystalline region of fumaric acid (III) is significantly larger than that of DL-malic acid (II) at six temperatures. Wilson, NRTL, and Margules models were used to correlate and predict binary and ternary system data and the corresponding calculation precision was assessed using relative average deviation (RAD) and root-mean-square deviation (RMSD). The calculated results of Wilson and NRTL models were consistent with experimental data, and maximum values of RAD and RMSD were 2.93 × 10−2 and 3.67 × 10−3, respectively. Margules model can be used to fit solubility data of DL-malic acid unlike those of fumaric acid. Interaction energy and hydrogen bond length of DL-malic acid and fumaric acid with water were calculated via molecular simulation, and the results can be used to explain solubility behavior of DL-malic acid and fumaric acid in water.

Determination, Construction, and Evaluation of Ternary and Quaternary Solid–Liquid Phase Equilibrium of Uric Acid, Adenine, and Guanine in Water

In this work, nine ternary phase diagrams and three quaternary phase diagrams of different systems at 298.15, 308.15, and 318.15 K were constructed. The ternary solid–liquid phase equilibrium of (u...

Research and comparison of solid-liquid phase equilibrium and ternary phase diagrams of 1-(3-nitrophenyl)ethanone + 1-(4-nitrophenyl)ethanone in different solvents

The ternary phase equilibrium for 1-(3-nitrophenyl)ethanone and 1-(4-nitrophenyl)ethanone in methanol or n-propanol were determined at 298.15, 308.15 K and 318.15 K under atmospheric pressure in this work. Based on the measured mutual solubility data, the isothermal ternary phase diagrams were constructed. In each ternary phase diagram, there were one co-saturated point, two boundary curves, and three crystalline regions. The crystallization region of 1-(3-nitrophenyl)ethanone was about the same as 1-(4-nitrophenyl)ethanone at all researched temperatures. The NRTL model was used to correlate the solubility of the ternary 1-(3-nitrophenyl)ethanone + 1-(4-nitrophenyl)ethanone + solvents. The correlation results were evaluated by the values of relative average deviation (RAD) and root-mean-square deviation (RMSD), and their values were 4.18 × 10−2 and 3.60 × 10−3, respectively. The calculated results via this model were all acceptable for ternary solid-liquid phase equilibrium. The ternary phase diagram obtained will play an important part in separating the mixture of 1-(3-nitrophenyl)ethanone and 1-(4-nitrophenyl)ethanone.

Construction and evaluation of ternary solid-liquid phase diagram of pyraclostrobin (form IV) and its intermediate in ethanol and N,N-dimethylformamide

Abstract In order to improve the purity of target product and reduce the cost of industrial production, the phase diagrams of pyraclostrobin and its intermediate (pheny N-methoxy-N- (2- ((N′-pyrazinyl) pyrazolyl-3′-oxymethyl) -phenyl) carbamate) in binary and ternary systems was studied. In each ternary phase diagram, there were three crystallization regions (pure pyraclostrobin intermediate, pure pyraclostrobin, and mixture of pyraclostrobin and its intermediate), two co-saturated curves, and one co-saturated point. The crystallization region of pyraclostrobin intermediate was larger than that of pyraclostrobin in ethanol and N, N-dimethylformamide (DMF) at three temperatures. In order to extend application of the obtained binary and ternary systems, the NRTL model and Wilson model were used to describing the solubility behaviour of pyraclostrobin and its intermediate in binary and ternary systems, the value of root-mean-square deviation (RMSD) was no more 9.01 × 10−3, the value of relative average deviation (RAD) was a little large, and no more than 5.84%. The calculated results via two models were all acceptable for the binary and ternary solid-liquid phase equilibrium. Ethanol and DMF in different temperature can be applied to separate the mixture of pyraclostrobin and its intermediate.

Experimental measurement and thermodynamic modeling of binary and ternary solid–liquid phase equilibrium for the systems formed by l -arabinose, d -xylose and water

Solid–liquid phase equilibrium data for binary (l-arabinose–water) and (d-xylose–water) systems at temperatures from (269.85–298.05) K and ternary (l-arabinose–d-xylose–water) system at temperatures of 273.85 K, 278.85 K and 284.45 K were measured at atmospheric pressure. The ternary phase diagrams of the systems were constructed on the base of the measured solubility. Two pure solid phases were formed at given temperatures, including pure l-arabinose and pure d-xylose, which were confirmed and determined by the method of Schreinemakers' wet residue. At the same temperature, the crystallization region of l-arabinose was larger than d-xylose's. The acquired solubility data were then correlated using the NRTL model, Wilson model and Xu model. The calculated solubility with the three models agreed well with the experimental values.

Binary and ternary solid-liquid phase equilibrium for the systems formed by succinic acid, urea and diethylene glycol: Determination and modelling

In this work, the solid-liquid phase equilibrium for binary system of succinic acid+diethylene glycol at the temperatures ranging from (298.15 to 333.15)K and ternary system of (succinic acid+urea+diethylene glycol) at 298.15K, 313.15K and 333.15K was built by using the isothermal saturation method under atmospheric pressure (101.2kPa), and the solubilities were determined by a high-performance liquid chromatography. The solid-phases formed in the ternary system of ((succinic acid+urea+diethylene glycol)) were confirmed by Schreinemaker’s method of wet residue, which corresponded to urea, succinic acid, and adduct 2:1 urea-succinic acid (mole ratio). Three isothermal phase diagrams for the ternary system were constructed based on the measured mutual solubility. Each isothermal phase diagram included six crystallization fields, three invariant curves, two invariant points and two co-saturated points. The crystalline region of adduct 2:1 urea-succinic acid is larger than those of the other two solids. The solubility of succinic acid in diethylene glycol was correlated with the modified Apelblat equation, λh equation and NRTL model; and the mutual solubility of the ternary ((succinic acid+urea+diethylene glycol)) system was correlated and calculated by the NRTL model. The interaction parameters’ values of succinic acid-urea were acquired. The value of RMSD was 7.11×10−3 for the ternary system. The calculation results had good agreement with the experiment values. Furthermore, the densities of equilibrium liquid phase were acquired. The phase diagrams and the thermodynamic model of the ternary system could provide the basis for design of the adductive crystallization process which was used to separate succinic acid with high purity from dicarboxylic acid mixtures.

Determination and modeling of binary and ternary solid-liquid phase equilibrium for the systems formed by 3,5-dinitrobenzoic acid, m-nitrobenzoic acid and acetone

The solubility of 3,5-dinitrobenzoic acid in acetone at the temperatures ranging from (283.15 to 318.15)K and the mutual solubility of the ternary m-nitrobenzoic acid+3,5-dinitrobenzoic acid+acetone system at (283.15, 298.15 and 313.15)K were determined experimentally by using the isothermal saturation method under atmosphere pressure (101.2kPa). Three isothermal ternary phase diagrams were constructed according to the measured mutual solubility data. In each ternary phase diagram, there was one co-saturated point, two boundary curves, and three crystalline regions. The modified Apelblat equation, λh equation, NRTL model and Wilson model were used to correlate the solubility of 3,5-dinitrobenzoic acid in acetone; and the NRTL and Wilson models, the mutual solubility for the ternary m-nitrobenzoic acid+3,5-dinitrobenzoic acid+acetone system. The value of root-mean-square deviation (RMSD) was 8.53×10−4 for the binary system of 3,5-dinitrobenzoic acid+acetone; and the largest value of RMSD was 81.08×10−4 for the ternary system.

Determination and modeling of binary and ternary solid-liquid phase equilibrium for the systems formed by 1,8-dinitronaphthalene and 1,5-dinitronaphthalene and N-methyl-2-pyrrolidone

The solubility of 1,8-dinitronaphthalene and 1,5-dinitronaphthalene in N-methyl-2-pyrrolidone at (293.15–343.15)K and the mutual solubility of the ternary 1,5-dinitronaphthalene+1,8-dinitronaphthalene+N-methyl-2-pyrrolidone mixture at (313.15, 328.15 and 343.15)K were determined experimentally using the isothermal saturation method under atmospheric pressure (101.2kPa). The solubility of 1,8-dinitronaphthalene in N-methyl-2-pyrrolidone is larger than that of 1,5-dinitronaphthalene. Three isothermal ternary phase diagrams were built according to the measured mutual solubility data. In each ternary phase diagram, there were one co-saturated point, two boundary curves, and three crystalline regions. Two pure solids (pure 1,8-dinitronaphthalene and pure 1,5-dinitronaphthalene) were formed in the ternary system at a given temperature, which were identified by Schreinemaker’s method of wet residue and powder X-ray diffraction (PXRD) pattern. The crystallization region of 1,8-dinitronaphthalene was smaller than that of 1,5-dinitronaphthalene at each temperature. The modified Apelblat equation, λh equation, NRTL model and Wilson model were used to correlate the solubility of 1,8-dinitronaphthalene and 1,5-dinitronaphthalene in N-methyl-2-pyrrolidone; and the NRTL and Wilson models were employed to correlate and calculate the mutual solubility for the ternary 1,5-dinitronaphthalene+1,8-dinitronaphthalene+N-methyl-2-pyrrolidone system. The largest value of root-mean-square deviation (RMSD) was 20.34×10−4 for the binary systems; and 7.38×10−3 for ternary system. The calculated results via these models are all acceptable for the binary and ternary solid-liquid phase equilibrium.

Determination and thermodynamic modeling of solid–liquid phase equilibrium for 3,5-dichloroaniline in pure solvents and ternary 3,5-dichloroaniline + 1,3,5-trichlorobenzene + toluene system

The solid–liquid phase equilibrium data for 3,5-dichloroaniline in n-propanol, isopropanol, n-butanol, isobutanol, toluene, ethyl acetate and acetone at (283.15 to 308.15)K were determined experimentally by gas chromatography under 101.3kPa. The solubility of 3,5-dichloroaniline in these solvents decreased according to the following order: ethyl acetate>(acetone, toluene) for the solvents of ethyl acetate, acetone, and toluene; and for the other solvents, (isopropanol, n-butanol)>n-propanol>isobutanol. According to the solubility of 3,5-dichloroaniline in pure solvents, the solid–liquid phase equilibrium for the ternary mixture of 3,5-dichloroaniline+1,3,5-trichlorobenzene+toluene were measured by using an isothermal saturation method at three temperatures of 283.15, 293.15, and 303.15K under 101.3kPa, and the corresponding isothermal phase diagrams were constructed. Two pure solids were formed in the ternary system at a fixed temperature, which were pure 3,5-dichloroaniline and pure 1,3,5-trichlorobenzene and were identified by Schreinemakers’ method of wet residue. The temperature dependence of 3,5-dichloroaniline solubility in pure solvents was correlated by the modified Apelblat equation, λh equation, Wilson model and NRTL model; and the ternary solid–liquid phase equilibrium of 3,5-dichloroaniline+1,3,5-trichlorobenzene+toluene were described by the Wilson model and NRTL model. Results showed that calculated solubility values with these models agreed well with the experimental ones for the studied binary and ternary systems. The solid–liquid equilibrium and the thermodynamic models for the binary and ternary systems can offer the foundation for purification of 3,5-dichloroaniline from its mixture.

Determination and modeling of binary and ternary solid–liquid phase equilibrium for the systems formed by adipic acid, urea and diethylene glycol

Solid–liquid phase equilibrium data for binary (adipic acid + diethylene glycol) and (urea + diethylene glycol) systems at temperatures from (298.15–333.15) K and ternary (adipic acid + urea + diethylene glycol) system at temperatures of 298.15 K, 313.15 K and 333.15 K were determined herein under pressure of 101.3 kPa. The corresponding solids formed in the ternary system were confirmed by Schreinemakers' method of wet residue. Three isothermal phase diagrams were constructed in terms of the measured mutual solubility data. Two pure solids were formed at each temperature, which corresponded to pure adipic acid and pure urea. The crystallization region of urea was smaller than that of adipic acid at each temperature. NRTL model and Wilson model were used to correlate the obtained solubility data, and the interaction parameters' values of adipic acid-urea were acquired. The calculated solubility with the two models agreed well with the experimental values.

Determination of CO2 Solubility in Saturated Liquid CH4 + N2 and CH4 + C2H6 Mixtures above Atmospheric Pressure

Accurate CO2 solubility data are crucial for putting a proposal of pressurized liquefied natural gas (PLNG) project into practice. A solid–liquid equilibrium (SLE) apparatus, which is based on the static–analytic method, has been set up to measure the solubility of carbon dioxide in saturated liquid CH4/CH4 + N2/CH4 + C2H6 in the pressure region from atmospheric up to 3 MPa, corresponding to the temperature region from (112 to 170) K. In addition, Peng–Robinson (PR) and Suave–Redlich–Kwong (SRK) equations-of-state (EOS) are selected to calculate the solubility of carbon dioxide in CH4 + N2 and CH4 + C2H6 mixtures, and the results are consistent with the experimental data in the whole region. Two temperature-dependent correlations for the interaction coefficients kij on CH4 + CO2 system are derived by the experimental data for PR and SRK EOS, which can improve the calculation accuracy of the binary and ternary solid–liquid phase equilibrium.

Modeling of phase equilibria for the evaporative precipitation of methacrylic acid and acetic acid from aqueous solutions

Models to describe/predict the phase equilibrium of aqueous solutions of carboxylic acids are of considerable importance to the chemical industry. Such acids (e.g. adipic acid, citric acid, acrylic acid) are obtained as solids during the production process and/or are purified by a combination of distillation and crystallization (i.e. evaporative crystallization). Therefore, for the computer-aided design of such processes, a thermodynamic model for the solid–liquid phase equilibrium is required which should also be able to describe the vapor–liquid equilibrium reliably. The present publication deals with the industrially important system methacrylic acid–acetic acid–water. Experimental data for the solid–liquid phase equilibrium are presented and compared to model predictions. The model takes into account physical interactions (through the UNIQUAC equation for the Gibbs excess energy) as well as the complexing due to hydrogen bonding (through chemical reaction equilibria). The acids are assumed to exist only as dimers (of the same carboxylic acid monomers) and cross-dimers (of two different acid monomers) in the liquid and solid phases. The model parameters were fitted to experimental data for the liquid–solid equilibrium of the binary subsystems only. The ternary solid–liquid phase equilibrium and the binary as well as the ternary liquid–liquid and the vapor–liquid phase equilibria were predicted and compared to experimental data. That comparison reveals a good agreement. Thus, the model provides a reliable basis for the computer-aided design of a downstream process which combines distillation and crystallization.