Equilibrium Data For Ternary Systems Research Articles

Study on the solid-liquid equilibrium and thermodynamic model of the L-phenylalanine + L-tryptophan + water system.

Amino acids hold significant importance in the diagnosis and treatment of various chronic diseases. Accurate solid-liquid equilibrium data are the key to drug synthesis and chemical production. However, the studies on the solid-liquid equilibrium of amino acids remain limited. In this work, the solid-liquid equilibrium of the L-tryptophan + L-phenylalanine + water ternary system under atmospheric pressure at temperatures of 278.15 K-318.15 K was explored via isothermal solution saturation. The isothermal equilibrium phase diagram of the ternary system was constructed. The obtained solid-liquid equilibrium data were correlated with a semi-empirical-model, yielding thermodynamic parameters pa, pb, pc, and k. Furthermore, the model can be used to effectively predict the solid-liquid equilibrium data of ternary systems at other temperatures, and the dY and dP are 0.005 and 4.34%, respectively. The solid-liquid equilibrium data and ternary equilibrium phase diagrams of the system were utilized for the separation and purification of an L-tryptophan and L-phenylalanine mixture. By employing thermodynamic models to calculate the relevant phase diagram data for mixtures with different proportions, effective separation and purification of the mixture could be achieved using the principles of variable temperature phase diagrams. These works are valuable for optimizing chemical processes and have practical implications in the field.

Liquid–liquid equilibria of ternary mixtures of methanol + MEG + n‐C5, ethanol + MEG + n‐C5, and n‐butanol + MEG + n‐C5

AbstractNew liquid–liquid equilibrium data of ternary systems of mono ethylene glycol + n‐pentane + methanol, mono‐ethylene glycol (MEG) + n‐pentane + ethanol, and mono ethylene glycol + n‐pentane + n‐butanol from 283.15 to 293 K are presented in this work. Binodal curves were obtained by the cloud point titration method. Tie‐line compositions were obtained through density and sound velocity measurements of phases in equilibrium. Results show that the solubility increases with temperature in all systems and decreases as the alcohol chain increases. The relative solubility data indicate that the alcohols are more soluble in MEG than in n‐C5. The obtained experimental data were successfully correlated using the CPA and the PC‐SAFT equation with appropriate binary interaction parameters.

Measurement and Thermodynamic Modeling of Liquid–Liquid Equilibrium Data for Ternary Systems (Water + Formaldehyde + Methyl Isobutyl Ketone/Cyclohexanone) at Different Temperatures

Measurement and Thermodynamic Modeling of Liquid–Liquid Equilibrium Data for Ternary Systems (Water + Formaldehyde + Methyl Isobutyl Ketone/Cyclohexanone) at Different Temperatures

Revising Concepts on Liquid–Liquid Extraction: Data Treatment and Data Reliability

The intention of this article is to clarify some concepts and relevant aspects of the experimental determination and treatment of liquid–liquid equilibrium data for ternary systems. Distinction is made between solubility curve and binodal curve, setting the stability limit which is defined by the spinodal curve. In addition, it is recommended to carry out the equilibrium data correlation using semiempirical models with a thermodynamic base, over the use of empirical equations. Moreover, the misuse of these empirical equations (Hand, Bachman, Othmer-Tobias, etc.) as proof of data quality or consistency is clarified.

Measurement and PC-SAFT modeling of the water activity for aqueous solutions of D-mannose in some deep eutectic solvents

The knowledge of thermodynamic properties for D-mannose has of great specific importance in viewpoint of biological behavior and understanding of solute-solvent interactions. In this work, vapor- liquid equilibrium data of ternary systems containing some deep eutectic solvents (DESs) based on choline chloride (ChCl/Urea - ChCl/Ethylene Glycol - ChCl/Glycerol) as co-solvent, D-mannose and water were measured using by isopiestic method at 298.15 K. The PC-SAFT EOS was used for predicting water activity and vapor pressure of water in the solutions. The binary interaction parameter kij between DES and D-mannose were determined from the average fitting parameter interaction of the binary DES-water and D-mannose-water systems. The calculated vapor pressure data with compared to excremental data show AAD% less than 0.09. The ternary (ChCl/Urea + D-mannose + H2O) system has the lowest amount of ARD. Also, the calculated Gibbs free energies of transfer ΔGtri of D-mannose from water to aqueous solution of DES supply favorable interactions between D-mannose with DESs and salting-in effect. Also, the glycerol based DES has stronger interactions rather than the others due to strong hydrogen bonding. Generally, the results indicate the high performance of PC-SAFT to calculate of vapor pressure of water and water activity in the ternary studied systems.

Measurement and Correlation of Liquid–Liquid Equilibrium Data for Ternary Systems of Water + Furfuryl Alcohol + (1-Pentanol and n-Propyl Acetate) at Different Temperatures

Measurement and Correlation of Liquid–Liquid Equilibrium Data for Ternary Systems of Water + Furfuryl Alcohol + (1-Pentanol and <i>n</i>-Propyl Acetate) at Different Temperatures

A Convenient Hybrid Method for Obtaining Liquid–Liquid Equilibrium Data in Ternary Systems

Liquid–liquid equilibrium data for ternary systems are scarce in literature, although they are important both for industry and simulations. Investigating ternary systems is usually costly and labor...

Extractive separation of tetralin-dodecane mixture using tetrabutylphosphonium bromide-based deep eutectic solvent

Separation of components of light cycle oil (LCO) into aromatic-rich and nonaromatic-rich fractions is the essential step for upgrading LCO to produce benzene, toluene, xylene enriched fraction, and high-quality diesel. In this work, extractive separation of model LCO which contains 70 wt% tetralin and 30 wt% dodecane was performed using deep eutectic solvent (DES) as the extractant and water as the anti-extractant. Tetrabutylphosphonium bromide (TBPB) and levulic acid (LA) at a molar ratio of 1:4 was determined as the extractant, due to its high and stable performance during extraction and regeneration processes. The liquid-liquid equilibrium data of ternary systems involving TBPB:LA(1:4) were then experimentally determined and fitted using non-random two-liquid model. The continuous extraction process was simulated and optimized, high mass purity (0.980 for tetralin and 0.987 for dodecane) and high recovery ratio (0.994 for tetralin and 0.954 for dodecane) were achieved.

Liquid-liquid equilibrium of systems containing triolein + (fatty acid/ partial acylglycerols/ester) + ethanol: Experimental data and UNIFAC modeling

The demand for biofuels, such as biodiesel, has a very powerful appeal nowadays. In some countries, such as Brazil, the biodiesel production by ethylic route has some advantages, since ethanol is a renewable alcohol produced in a large scale and at a competitive production cost. Besides being an alternative reactant, ethanol can be used as a solvent for extracting vegetable oils from seeds and also for deacidifying crude vegetable oil by liquid-liquid extraction. Such characteristics of ethanol suggest the need to investigate the ethylic route for biodiesel production. The comprehension of liquid-liquid equilibrium (LLE) is essential for the design and optimization of liquid-liquid extraction for deacidification processes of vegetable oils and for systems which correspond to the initial stage of transesterification reaction with ethanol. In this context, this study aimed to measure the liquid-liquid equilibrium data of ternary systems with pure fatty components containing triolein + (fatty acid or partial acylglycerols or ester) + ethanol at 45 °C. As the prediction of UNIFAC with literature parameters was poor, these ternary data were used to readjust the UNIFAC parameters. The global average deviation between experimental and calculated compositions decreased from 6.48% to 1.48%. The prediction capacity of the UNIFAC model with this new parameter set was evaluated in multicomponent systems related to biodiesel production. An improvement in the prediction of the LLE with these parameters was achieved in comparison to the results using the original UNIFAC parameters available in the literature.

Liquid–Liquid Equilibrium for Ternary Systems, Water + 5-Hydroxymethylfurfural + (1-Butanol, Isobutanol, Methyl Isobutyl Ketone), at 313.15, 323.15, and 333.15 K

Liquid–liquid equilibrium (LLE) data was very important for the process design and optimization of 5-hydroxymethylfurfural (5-HMF) production. To provide this fundamental data, experimental liquid–liquid equilibrium data for ternary systems, {water + 5-HMF + 1-butanol}, {water + 5-HMF + isobutanol}, and {water + 5-HMF + methyl isobutyl ketone}, were measured at 313.15, 323.15, and 333.15 K. Partition coefficients were used to assess the extraction capacity of organic solvents in the biphasic systems. 1-Butanol and isobutanol were desirable extractants with good extraction performance and environmental benign properties. The NRTL model was used to correlate the experimental data and the binary interaction parameters were obtained. The average relative deviation was lower than 10%.

Direct Separation of Olefins from Aromatics or Sulfides: Influence of the Structure and Content of Olefins and Aromatics

In order to disclose the separation of olefins from aromatics or thiophene compounds by organic solvents, vapor–liquid equilibrium data for ternary systems of olefins + aromatics/thiophenes + sulfolane (SUL) /N-methyl-2-pyrrolidone (NMP) were investigated at atmospheric pressure in a modified Rose dual-circulating vapor–liquid distiller. This work primarily focused on studying the relationship between separation efficiency on olefins and the structure and concentration of olefins and aromatics. From the point view of structure, the results showed that more methyl existing on both olefins and aromatics could lead to stronger hydrogen bond interaction with solvents than that of olefins and aromatics, which do not include methyl in their molecular structure. So there was higher olefin-separating efficiency for the systems containing 1-hexene (HEX)/3-methylthiophene (MTHI)/1,2,4-trimethylbenzene (TMB) than those of 2,4,4-trimethylpentene (TMP)/thiophene (THI)/toluene (TOL), respectively. Besides, when it came...

Liquid-liquid equilibrium for ternary systems, methyl isobutyl ketone + (catechol, resorcinol and hydroquinone) + water at 333.15 K, 343.15 K and 353.15 K

Liquid-liquid equilibrium (LLE) data are vital to extraction process design and optimization. To provide fundamental data for the extracting process of dihydric phenol from wastewater, experimental liquid equilibrium data for ternary systems {methyl isobutyl ketone + catechol + water}, {methyl isobutyl ketone + resorcinol + water} and {methyl isobutyl ketone + hydroquinone + water} were determined at 333.15 K, 343.15 K and 353.15 K under atmospheric pressure. The NRTL and UNIQUAC models were used to correlate the experimental data and relevant binary interaction parameters were yielded. The experimental data were successfully correlated with the two models, and the root mean square deviations (RMSD) between the calculated and experimental values were less than 2%. Moreover, NRTL model performed slightly better than UNIQUAC model since the RMSD was smaller. Distribution coefficient and selectivity were employed to assess methyl isobutyl ketone's extraction capacity, which indicate that, methyl isobutyl ketone is a desirable extractant with extraction performance and physiochemical properties outperforming other extractants.

Correlation of three-liquid-phase equilibria involving ionic liquids.

The difficulty in achieving a good thermodynamic description of phase equilibria is finding a model that can be extended to a large variety of chemical families and conditions. This problem worsens in the case of systems containing more than two phases or involving complex compounds such as ionic liquids. However, there are interesting applications that involve multiphasic systems, and the promising features of ionic liquids suggest that they will play an important role in many future processes. In this work, for the first time, the simultaneous correlation of liquid-liquid and liquid-liquid-liquid equilibrium data for ternary systems involving ionic liquids has been carried out. To that end, the phase diagram of the water + [P6 6 6 14][DCA] + hexane system has been determined at 298.15 K and 323.15 K and atmospheric pressure. The importance of this system lies in the possibility of using the surface active ionic liquid to improve surfactant enhanced oil recovery methods. With those and previous measurements, thirteen sets of equilibrium data for water + ionic liquid + oil ternary systems have been correlated. The isoactivity equilibrium condition, using the NRTL model, and some pivotal strategies are proposed to correlate these complex systems. Good agreement has been found between experimental and calculated data in all the regions (one triphasic and two biphasic) of the diagrams. The geometric aspects related to the Gibbs energy of mixing function obtained using the model, together with the minor common tangent plane equilibrium condition, are valuable tools to check the consistency of the obtained correlation results.

Simultaneous VLLE data correlation for ternary systems: Modification of the NRTL equation for improved calculations

Simultaneous correlation of vapour–liquid–liquid equilibrium (VLLE) data is hardly ever attempted in literature with one common set of parameters for all the equilibrium regions present in the systems. It is common practice to obtain different sets of parameters for VLE, LLE and VLLE regions when experimental equilibrium data for ternary systems are fitted with a given model (e.g. an activity coefficient model for the liquid phase). Besides, when dealing with the correlation of VLE for ternary systems, it is quite frequent to obtain different sets of parameters for each one of the three binary subsystems from those obtained when exclusively binary VLE data are correlated. In the present work, the simultaneous correlation of all the equilibrium regions in the ternary VLL system is attempted. The objective function and the restrictions of the system are clearly presented. In addition, a simple modification of the NRTL equation for the Gibbs energy of mixing (GM) is proposed including a ternary term and a binary correction based on the Wohl equation. This modification has significantly improved the quality of the results obtained in the simultaneous correlation of different equilibrium regions.

Antisolvent Precipitation of Potassium Bicarbonate from KHCO3 + H2O + Ethanol/2-Propanol Systems in the CO2 Capture Process

For the energy-saving hot carbonate process, which contains a crystallization step, the antisolvent precipitation of potassium bicarbonate was investigated by adding ethanol and 2-propanol in a simulated effluent solution of CO2 absorption column. The feasibility of using the antisolvent was verified with the equilibrium data of ternary systems and a KHCO3 recovery. The ternary systems of KHCO3 + H2O + ethanol/2-propanol were equilibrated with varying amounts of alcohols at a preset temperature, and the equilibrium concentrations were determined using the cloud point method. In the ethanol system, a homogeneous and a solid–liquid phase were observed, whereas in the 2-propanol system, a liquid–liquid phase as well as the homogeneous and solid–liquid phases were observed. The equilibrium data were correlated with a local concentration parameter in the range of the antisolvent. From the correlation, the amount of antisolvent that has an effect equivalent to a cooling-only method and the optimum concentration...

Liquid–liquid equilibria in the ternary systems water + cresols + methyl butyl ketone at 298.2 and 313.2 K: Experimental data and correlation

Liquid–liquid equilibrium data for ternary systems (water+o-, m- or p-cresol+methyl butyl ketone) were measured at 298.2 and 313.2K under atmospheric pressure by gas chromatography. Distribution coefficients and separation factors were calculated to evaluate the extracting performance of methyl butyl ketone. For each system, the Hand and Othmer–Tobias equations were used to assess the quality of LLE data. These data were also correlated using NRTL and UNIQUAC models to yield binary interaction parameters for designing or optimizing cresols extracting process.

Liquid–liquid phase equilibrium for ternary mixtures of formamide (or ethylene glycol, or monoethanolamine) + indole + 2-methylnaphthalene at 308.15 K

Liquid–liquid phase equilibrium data for ternary systems containing formamide (or ethylene glycol (EG), monoethanolamine (MEA)+indole+2-methylnaphthalene (2-MN) at 308.15K under atmospheric pressure were measured in this work. The results show that all the three ternary systems are Treyball type 1 systems. The experimental data were correlated well using both the non-random two liquid (NRTL) model and universal quasi-chemical activity coefficient (UNIQUAC) model. In addition, both the distribution coefficient and selectivity coefficient of formamide, EG and MEA were calculated to investigate the feasibility of extracting indole from 2-MN and formamide presented a better selectivity.

Liquid–Liquid Equilibrium of Aqueous Biphasic Systems Containing Ethylene Oxide–Propylene Oxide Block Copolymers and Maltodextrins

This work presents liquid–liquid phase equilibrium data of ternary systems formed by aqueous mixtures of ethylene oxide–propylene oxide block copolymers and maltodextrin. Phase diagrams were obtained for five copolymers (with EO ratios ranging from 20 % to 80 % and molar masses ranging from 1900 g·mol–1 to 8400 g·mol–1) and three maltodextrins (with number averaged molar masses of 990 g·mol–1, 1500 g·mol–1, and 3000 g·mol–1) at 298.2 K and 308.2 K. The main factor influencing the phase diagrams is the ratio between ethylene oxide and propylene oxide chain sizes. The size distribution of maltodextrin was studied through gel permeation chromatography, and the size distribution of some equilibrium phases was also determined. Maltodextrin was found to partition unevenly between equilibrium phases, with larger molecules being excluded from the polymer-rich phases. The phase equilibrium was modeled using the UNIQUAC equation and with the consideration that maltodextrin can be represented by six pseudocomponents...

Optimization of the methylic biodiesel purification process by intermediate of liquid–liquid equilibrium data for ternary systems containing methanol + water + (soybean, corn or brown shell of coconut) biodiesel

Biodiesel is usually produced by transesterification reactions, by intermediate of a catalytic reaction in which a source of triglycerides (from vegetable, animal or residual oils) reacts with excess of alcohol producing as main product biodiesel and as side-product glycerol. After those reactions, it is usually necessary to purify the biodiesel produced by settling process. This step is followed by liquid–liquid extraction (wash up) unit operation. Systematic studies on biodiesel washing process, especially as function of composition data, are still scarce in the literature. Liquid–liquid equilibrium data provide important means to the development and design of equipment and also in the optimization of the extraction processes. This paper, as part of continuing study in our research group, reports equilibrium data for different ternary systems of methanol+water+(soybean, corn or brown shell of coconut, here named coconut) biodiesel at 293.15 and 313.15K at atmospheric pressure. Experimental data were carried out in equilibrium cells, by using a bath, in order to control the temperature of the system. From experimental data, distribution coefficients of methanol have been determined. The quality and reliability of the tie-line were tested by Othmer-Tobias and Hand correlations. Liquid–liquid equilibrium (LLE) data were correlated with the following activity coefficient models: NRTL, UNIQUAC and UNIFAC, with a global deviation error of 1.34%, 1.34% and 4.13%, respectively.

Liquid–liquid equilibrium data for ternary systems of water + lactic acid + C4–C7 alcohols at 298.2 K and atmospheric pressure

Liquid–liquid equilibrium data for water+lactic acid+{1-butanol or 2-butanol, 1-pentanol, 1-hexanol, 1-heptanol} systems at T=298.2K and atmospheric pressure (≈95kPa) were determined by density and refractive index measurements. The systems present Treybal's type I binodal curves. Obtained tie line data were correlated with NRTL model. Cloud points, tie lines, partition coefficients, selectivities and percent of extraction indicate that 1-pentanol is better than the other solvents studied for lactic acid removal from water.