Liquid Equilibrium Research Articles

Experimental study on solid–liquid equilibrium behavior of methimazole (Form Ⅰ) in twelve mono-solvents: Measurement, modeling, Hansen solubility parameters and thermodynamic analysis

Methimazole is an active pharmaceutical ingredient, which is commonly used as an imidazole antithyroid drug. Solubility research is one of the key steps affecting the crystal quality of methimazole, which can give essential fundamental data and theoretical guidance for its downstream industries, such as preparation form, storage, transportation and clinical application. Researchers have found that there are two crystal forms of methimazole, different crystal forms may result in differences in the efficacy, pharmacology, physicochemical properties, etc. Further supplementation and improvement are urgently needed regarding the solid–liquid equilibrium data, dissolution thermodynamic properties and dissolution mechanism of methimazole. In the present work, by using a gravimetric method, the solubility of methimazole (Form Ⅰ) in twelve selected mono-solvents including 2-propoxyethanol, isopropyl acetate, anisole, 2-ethoxyethanol, 1-hexanol, 1-pentanol, ethylene glycol, butyl acetate, 2-butoxyethanol, propyl acetate, 2-methoxyethanol and ethyl butyrate was investigated from 283.15 K to 323.15 K under pressure of 0.1 MPa. The regression result between solubility and temperature showed that they were positively correlated. At 298.15 K, the obtained mole fraction solubility of methimazole (Form Ⅰ) decreased as: 2-methoxyethanol (0.2203) > 2-ethoxyethanol (0.1766) > ethylene glycol (0.1432) > 2-propoxyethanol (0.1425) > 2-butoxyethanol (0.1268) > 1-pentanol (0.0394) > 1-hexanol (0.0349) > propyl acetate (0.0223) > butyl acetate (0.0195) > anisole (0.0176) > isopropyl acetate (0.0135) > ethyl butyrate (0.0120). The maximum solubility was found in 2-methoxyethanol at 323.15 K with the mole fraction solubility value of 0.2984, while the minimum obtained value was occurred in ethyl butyrate at 283.15 K with the mole fraction solubility of 0.00786. Besides, four thermodynamic nonlinear regression models including Yaws model, UNIQUAC model, Two-Suffix Margules model and NRTL-SAC model were used to correlate the experimental solubility of methimazole (Form Ⅰ). Furthermore, to further explore the dissolution mechanism of methimazole (Form Ⅰ) in the selected twelve target solvents, the HSPs, Hirshfeld surface analysis and dissolution thermodynamic properties were calculated and analyzed.The related research in this study is of great significance for understanding the solubility behavior and dissolution mechanism of methimazole Form I in the selective solvent system, which can provide foundation data for the optimization of its crystallization conditions. At the same time, this study is helpful to provide theoretical guidance for the research of other similar drugs.

Liquid-liquid equilibria and intermolecular interactions for extraction of 2-methyl phenol, 3-methyl phenol and phenol from water by a ternary hydrophobic deep eutectic solvent

BackgroundHydrophobic deep eutectic solvents (HDESs) are environmentally friendly solvents that can be used to extract water pollutants, including phenolic compounds. MethodsIn this research, a ternary HDES (thymol: caprylic acid: capric acid = 1:1:1, molar ratio) has been used for the extraction of 2-methyl phenol, 3-methyl phenol and phenol from water. The effect of the HDES on liquid-liquid phase behavior of the ternary mixtures (2-methyl phenol/ 3-methyl phenol / phenol + HDES + water) at 298.15 K was discussed. The NRTL model has been used to correlate the experimental data. The selectivity and distribution coefficient were calculated as the important indexes for evaluating the extraction potential of the ternary HDES. Significant FindingsThe results showed that the ternary HDES can be used as a good extractant for the extraction of 2-methyl phenol, 3-methyl phenol and phenol. Besides, the ternary HDES could extract 2-methyl phenol and 3-methyl phenol better than phenol from their aqueous solutions. Electrostatic potentials, interaction energies and reduced density gradients were used to further investigate the interactions of 2-methyl phenol, 3-methyl phenol and phenol with the ternary HDES.

Vapor–Liquid Equilibrium Data and Thermodynamic Modeling for Binary Systems Consisting of Perfluorobutane (R610) with Oxygen or Nitrogen at (293, 313, and 333) K

Vapor–Liquid Equilibrium Data and Thermodynamic Modeling for Binary Systems Consisting of Perfluorobutane (R610) with Oxygen or Nitrogen at (293, 313, and 333) K

Thermodynamic Modeling of an Aqueous N, N-Dimethyldipropylenetriamine and Benzylamine Blend for Efficient CO2 Capture.

This study evaluates the carbon dioxide (CO2) capture capabilities of a novel aqueous blend of N,N-dimethyldipropylenetriamine (DMDPTA) and benzylamine (BA). The solvent properties such density, vapor- liquid equilibrium (VLE) of CO2 in the solvent, CO2 absorption enthalpy are evaluated experimentally for solvent composition of (5 mass % DMDPTA+25 mass % BA), (10 mass % DMDPTA+20 mass % BA), and (15 mass % DMDPTA+15 mass % BA). Solvent density were measured in the temperature range of 303 K-333 K and correlated using Redlich-Kister excess molar volume model, with a low average absolute relative deviation (AARD) of 0.014. VLE data was measured using a custom-made stirred VLE cell, within CO2 partial pressure range of 2-200 kPa and at temperatures 313 K, 323 K and 333 K. Equilibrium CO2 solubility data were correlated using a modified Kent-Eisenberg model, achieving an AARD of 1.5 %. Enthalpy of CO2 absorption was measured at 313 K using a Meter Toledo reaction calorimeter. Results indicated that under similar process conditions and solvent composition, (DMDPTA+BA) blends exhibited significantly higher CO2 loading and low absorption enthalpy compared to aqueous BA and monoethanolamine solvent alone indicating the potential of (DMDPTA+BA) blend as efficient CO2 capture solvent.

Testing the prediction capability of trained models: sildenafil citrate solubility in propylene glycol and 1-propanol mixtures at different temperatures

ABSTRACT This study investigates the thermodynamic characteristics, equilibrium solubility, and solvation dynamics of sildenafil citrate within binary solvent systems composed of propylene glycol and 1-propanol. Utilizing both determination and computational approaches, the solubility patterns of sildenafil citrate were quantitatively assessed, revealing direct proportionality with increments in temperature and the concentration of propylene glycol. A comparative analysis using three distinct mathematical models to represent the solid–liquid phase equilibrium was conducted. Among these, the Jouyban-Acree-van’t Hoff model yielded the most comprehensive correlation by covering the effects of both temperature and solvent composition variations on the solubility, with a mean relative deviation (MRD%) of 6.4%, suggesting a robust alignment between the modelled and experimental solubility data. Previously trained models were tested to predict the solubility of the drug in mono- and mixed-solvents at various temperatures where accurate predictions were obtained with the MRD% of 19.1% (for mono-solvents), 8.1 and 14.4% (for mixed solvent systems).

Toward nanosuspension preparation by modeling the solubility of levofloxacin and ofloxacin in ethanol + water solvent mixtures at different temperatures

The present study was conducted to assess the solubility of levofloxacin and ofloxacin in different mono- and mixed solvent systems at different temperatures to provide an experimental basis for the preparation of levofloxacin and ofloxacin nanosuspensions. To this end, the solubility of both compounds was evaluated using a solid–liquid equilibrium technique in DMSO, acetone, ethanol, NMP, and water monosolvents and ethanol–water mixed solvents at different volume fractions and temperatures. The modified versions of the van’t Hoff and Gibbs equations were recruited to calculate the thermodynamic properties of the solutions. The correlation between the solubility data of levofloxacin and ofloxacin and different mathematical models, including the Yalkowsky, Jouyban-Acree, and van’t Hoff models and their combinations was studied. According to the results, the highest and lowest solubility of levofloxacin and ofloxacin were attainable in 1 (pure ethanol monosolvent) and 0.1 v/v of ethanol fractions in ethanol/water mixed solvent. Moreover, the solubility of both compounds was superior at higher temperatures. Afterwards, the nanosuspensions were prepared using the solvent-antisolvent method. Different characterization techniques revealed the formation of the smallest particles with relatively irregular morphology in the 0.1 v/v volume fraction of ethanol in water. The XRD analysis exhibited the typical crystalline diffractions of levofloxacin and ofloxacin and the thermal transitions and stability of both compounds were investigated using DSC and TGA techniques. The results obtained in this study could be used to enhance the solubility and bioavailability of levofloxacin and ofloxacin during the drug formulation development and manufacturing processes.

Investigation on vapour–liquid equilibrium (VLE) solubility of CO2 in aqueous solutions of amino sugars

AbstractAmino sugars, which are candidate CO2‐capturing solvents, react reversibly with CO2, thereby setting up vapour–liquid equilibrium (VLE). Knowing equilibrium data is useful for designing gas–liquid contactors for CO2 absorption. In this work, VLE data for two amino sugars, glucosamine (GA) and N‐methyl‐D‐glucamine (NMG), was measured and reported at 303, 308, and 313 K using a high‐pressure VLE setup for the first time. The equilibrium CO2 partial pressure was high (up to 1500 kPa). The molarity of sugar in the aqueous solution was in the 0.5–1.25 M range. It was found that the CO2 loading capacity of NMG was much higher than that of GA. For instance, 1.25 M NMG loaded 1.066 mol/mol at 303 K and 1500 kPa CO2 partial pressure. Using regression, empirical equations were developed to predict VLE data for GA and NMG. To enable comparison, VLE trials were also performed using two amines, monoethanolamine (MEA) and 2‐amino‐2‐methyl‐1‐propanol (AMP), and an amino acid salt potassium glycinate (PG). It was found that CO2 solubility (α, mol/mol) in NMG was comparable to that in MEA and higher than that in PG. Besides, it was also found that CO2 was most soluble in AMP. The effect of promoter addition on the loading capacity at T = 308 K was studied too. The value of CO2 solubility in GA solution (1 M) at = 1450 kPa was α = 0.298 mol CO2/mol amino sugar. It improved to α = 0.46 mol/mol in GA/NMG (1/0.5 M) mixtures. Similarly, the CO2 solubility in NMG solution (0.75 M) at = 250 kPa was α = 0.76 mol CO2/mol amino sugar. It improved to 0.94 and 0.93 mol/mol in NMG/PZ and NMG/AMP (0.75/0.25 M) mixtures (here, PZ denotes piperazine). In this way, this work provided new and useful VLE data for individual and blended sugar solutions.

SOME COMMENTS ON THE NATURE OF GLASSES

ABSTRACT I undertake a brief presentation of the early history of the development of our modern understanding of glass-forming liquids that provides a look at how the scientific and technological communities were viewing the state of the art and how the knowledge in the field developed. I discuss aspects of our understanding from how the Vogel–Fulcher–Tammann (VFT) equation became known to questions about the development of the concept of the “ideal” glass transition. The framework for this history leads us to ask whether some of the cautions that the pioneering researchers provided should have been taken more seriously by the community. I discuss, in particular, the view presented by Tammann and Hesse [Z. Anorg. Allg. Chem. 156, 245 (1926)] cautioning that the apparent singularity of the viscosity at a finite temperature was not physical and how the, now famous, VFT equation is accurate for interpolation rather than for extrapolation. The other point is the strong sense by much of the glass community that the so-called Kauzmann paradox [Chem. Rev. 43, 219 (1948)] is fundamental to glass-formation despite the comment by Kauzmann himself that the extrapolation of the entropy to negative values is “operationally meaningless.” I build on these ideas through a presentation of my own data and that of others that addresses the Tammann and Hesse comment through experiments that show that there is not a viscosity (or relaxation time) divergence near to the Kauzmann or VFT temperatures, and I show that the equilibrium entropy of a polymer that cannot crystallize shows no evidence of an ideal glass transition that is often invoked as a means of avoiding the Kauzmann paradox. In addition to providing some sense of the history of time (or a brief history of time and temperature in glass-forming liquids, with apologies to Stephen Hawking) and viscosity, I think that the data presented lead to the conclusion that much of our understanding of the problem of glass-formation is based on misleading interpretations of the original works as well as being inconsistent with the newer data that have been published over that past 25 yr or so. On an optimistic note, there are newer models that do not rely on the VFT divergence or the Kauzmann paradox to account for glass-formation in supercooled or equilibrium liquids. In addition, the experimental situation clearly leads to the possibility of deeper investigations into the “deep glassy state” through “finessing” the geological timescale issue of creating equilibrium glasses. Such investigations are ultimately important to understanding behavior of glassy materials, especially polymers, that are used deep in the glassy state, but still close enough to the glass temperature that models able to reliably predict their behavior require better representations of glass-formation to engineer their performance.

Vapour–liquid equilibrium using quantum chemical molecular dynamics simulation and radial distribution function analysis

AbstractInstead of the classical molecular simulation widely implemented for estimating the vapour–liquid equilibrium (VLE), a quantum chemical (QC) molecular dynamics simulation was applied to the VLE estimation in three typical systems that include a deep eutectic solvent (DES) and an ionic liquid (IL). In addition, a radial distribution function (RDF) was derived from the QC simulation to examine the molecular behaviour in the liquid phase. A mean absolute error of 2.72% was obtained from the QC simulation compared to the experimental data. The RDF analysis explains the relative volatility increase of the acetic acid and water binary system with the propyl acetate solvent. This analysis indicated that the DES mixture comprising glycerol and choline chloride facilitated the separation of water and i‐propanol. The interaction between water and ethyl sulphate pair with the help of 1‐ethyl‐3‐methylimidazolium as an IL is stronger than that between ethanol and water, which explains how the IL improves ethanol and water separation in the vapour phase.

COSMO-RS prediction, experimental investigation, and mechanism analysis: A new approach to separating the n-hexane - tert-butanol azeotropic system via liquid-liquid extraction with ionic liquids

n-Hexane and tert-Butanol (TBA) are frequently utilized to refine the conditions for Grignard, Wittig, and Friedel-Crafts alkylation reactions. During the synthesis of loratadine, the formation of azeotropic mixtures n-hexane and TBA, which are challenging to separate through conventional distillation, is inevitable. This study utilizes the COSMO-RS model to identify suitable ionic liquids (ILs) for the separation of the n-hexane - TBA azeotropic system. Based on solvent capacity and selectivity, 1-ethyl-3-methylimidazolium trifluoroacetate ([EMIM][TFA]), 1-butyl-3-methylimidazolium trifluoroacetate ([BMIM][TFA]), and 1-hexyl-3-methylimidazolium trifluoroacetate ([HMIM][TFA]) were selected as extractants. The liquid–liquid equilibrium (LLE) data for the n-hexane - TBA - ILs ternary system were measured at 303.15 K and atmospheric pressure. Distribution coefficients and selectivity were calculated to evaluate the performance of the extractants, with the NRTL model used to correlate the experimental LLE data. The consistency of the NRTL model parameters was corroborated through topological analysis associated with the Gibbs tangent principle. Quantum chemical calculations, including interaction energy, ESP analysis, IGMH analysis, and QTAIM topological analysis, were performed to explore the separation mechanism at the molecular level. The results indicated that the interaction energies between the ILs and TBA were higher than those between the ILs and n-hexane, indicating a stronger attraction of ILs to TBA. Consequently, the ILs effectively separated TBA from the n-hexane - TBA azeotropic system, with extraction capacities ranked as [EMIM][TFA] > [BMIM][TFA] > [HMIM][TFA]. The quantum chemical calculations successfully explained the experimental results, aligning with COSMO-RS model predictions and confirming their reliability. IGMH and QTAIM topological analyses systematically explored the types and strengths of interactions, revealing that hydrogen bonds are predominant between the ILs and TBA, with additional contributions from van der Waals forces. Furthermore, the hydrogen bond strengths between TBA and the anions and cations of the ILs are classified as strong and moderate, respectively. This work provides valuable insights into the separation of azeotropic systems using ILs, elucidating the underlying mechanisms behind this process.

Vapor–Liquid Equilibrium Phase Behavior for Binary Mixtures Isopropyl Alcohol and Methyl Ethyl Ketone with Dimethyl Sulfoxide

Vapor–Liquid Equilibrium Phase Behavior for Binary Mixtures Isopropyl Alcohol and Methyl Ethyl Ketone with Dimethyl Sulfoxide

Separation of Benzene from Cyclohexane by Liquid-Liquid Extraction for a pseudo-ternary system with (Sulfolane + 2-propanol) solvent: An experimental and Modeling study

Since the condensation temperatures of Cyclohexane and Benzene are close, the distillation process is useless for extraction, and it must be done with the help of a solvent. Sulfolane is widely used as a solvent for extracting aromatic hydrocarbons. The experimental (Liquid-Liquid) equilibrium (LLE) data will measure the ternary system of [Sulfolane + Benzene + Cyclohexane] and the pseudo-ternary systems (PTS) of [(Sulfolane + 2-propanol) + Benzene + Cyclohexane] at a temperature of 303.15 K under atmospheric pressure. Experimental distribution coefficients and selectivity factors were presented to evaluate the efficiency of the solvent for the extraction of benzene from cyclohexane. Solvents included pure sulfolane and a mixture of sulfolane with 5, 10, and 20% mass fractions of 2-propanol. The results indicated that adding 10% and 20% propanol to sulfolane leads to an increase of 70% and 169% in selectivity and a decrease of 14.3% and 2.9% in distribution coefficient respectively. It was found that using the cheaper solvent of Sulfurane + 2-Propanol can have the same efficiency in extracting cyclohexane from benzene compared to the expensive solvent of Sulfurane. The LLE data of the studied system are used to achieve binary interaction parameters in universal quasichemical)UNIQUAC(and non-random two-liquid)NRTL(thermodynamic models. They minimize the root mean square deviations (RMSD) between the experimental data and the computed results. The UNIQUAC model fits better with the liquid-liquid equilibrium data set for the systems considered. The low values of RMSD indicate that the ternary and pseudo-ternary systems could be well-fitted by the NRTL and UNIQUAC models. RMSDs achieved measuring computed and experimental two-phase compositions are 0.0481 for the UNIQUAC and 0.0512 for the NRTL models.

Toward understanding the solid-liquid equilibrium behavior of dinotefuran by thermodynamic analysis and molecular dynamic simulation

Dinotefuran is a third-generation nicotinic insecticide with a wide insecticidal spectrum and low toxicity to humans and other mammals, which has a huge potential market. The insight into the solid–liquid equilibrium behavior of dinotefuran in various solvents could further guide the design, development, and refinement of the further crystallization process. However, the complexity and variability of the dissolution process make it very challenging to study. In this research, the solid–liquid equilibrium of dinotefuran in both mono-solvents and mixed solvents was systematically investigated through a combined approach of the experimentation and molecular dynamics simulation. Firstly, the solubility of dinotefuran in a range of solvents was ascertained using the laser dynamic monitoring method over spanning temperatures from 278.15 to 318.15 K. The results showed that the solubility of dinotefuran in mono-solvents increase with the temperature increasing, while the solubility in mixed solvents exhibited an initial increase followed by a decrease with the organic solvent molar fraction increasing. Then the experimental data were fitted using five thermodynamic models. The NRTL model has the lowest 102ARD and 104RMSD values, indicating the best correlation, validity and fit. The dissolution behavior of dinotefuran was explored by calculating the thermodynamic properties. The results indicated that dinotefuran dissolution was a spontaneous, disorder degree increase process, and dissolution an exothermic process except the isopropanol + water mixed solvents. Additionally, the influence of the physicochemical properties of the solvent on the dinotefuran dissolution process was investigated, with a particular focus on the critical role of solvent polarity. Hansen solubility and the preferred solvation parameters of dinotefuran in the solvents were also further calculated to analyze the dissolution process. For the studied mixed solvents, when the ratios of methanol, ethanol, isopropanol, and acetone reached 0.85, 0.75, 0.50, and 0.70, respectively, dinotefuran molecules turned to be preferentially solvated by the water molecules. Finally, molecular dynamics simulation was performed to reveal the mechanisms of dinotefuran dissolution, suggesting the greater solute–solvent interaction, the easier dissolution. The solid–liquid equilibrium data might provide a guidance for the development of environment-friendly and efficient formulation.

Comparison of liquid–liquid phase equilibrium behavior of acetonitrile–water system using choline chloride salt and water-based deep eutectic solvent

The liquid–liquid equilibrium (LLE) data for the ternary systems of (acetonitrile (ACN) + water (W) + choline chloride (ChCl)) and (ACN + W + water-based deep eutectic solvent (WDES) consisting of ChCl:W (1:3)) were measured at 298 K. The consistency of tie-lines was verified by the Bachman and Othmer–Tobias correlations. ChCl as an organic salt and its WDES (within the water content range of less than 50 w%) as green extractants represent feasible performances in terms of selectivity and distribution coefficients for separation of water from acetonitrile-water system in comparison to other inorganic salts and hydrophobic DESs. ChCl in the (ACN + W + ChCl) system can separate water from the solution in the form of hydrate ions while WDES in the (ACN + W + WDES) system tends to absorb water by intermolecular forces. The experimental data of the (ACN + W + ChCl) system was correlated using the symmetric electrolyte non-random two liquid (e-NRTL) model while the equilibrium data of the (ACN + W + WDES) system was correlated using NRTL and universal quasi-chemical activity coefficient (UNIQUAC) models. ChCl in the form of salt represents a better separation performance than WDES for water removal from the acetonitrile mixture. Meanwhile, WDES might be considered to be superior compared to ChCl in terms of regeneration energy consumption and operating considerations.

Recycled crystal population proving complex plumbing systems: an archetypal example from Cretaceous alkaline magmatism in SE Brazil

Porphyritic alkaline dykes from the Serra do Mar province (SE Brazil) carry clinopyroxene macrocrysts with a complex magmatic history. Clinopyroxene is the main macrocryst phase from the Bom Repouso dyke, representing different populations. Based on petrographical features, mineral chemistry and equilibrium relationships, the clinopyroxene populations are classified as antecrysts (green cores and colourless cores and mantles) and phenocrysts (Ti-augite mantle/rims). Calculated compositions for the liquid in equilibrium with the macrocryst cores indicate mafic (colourless cores) and felsic (green cores) alkaline melts. These were used as poles for mixing-model curves, revealing a hybrid origin for the host matrix. Clinopyroxene barometry reveals key insights into the plumbing systems of the Serra do Mar province, with the Bom Repouso dyke as an archetypal example of these transcrustal systems. All target bodies record a crystallization history over a continuous range of pressures (>8 kbar up to the surface). Some preferred levels for magma storage are observed: c. 0–0.5, 1–2.5, 3–4 and 5.5–7 kbar. Our work highlights the complex magmatic history of the Serra do Mar alkaline occurrences, encompassing several open-system effects. A thorough petrographical examination is necessary to enhance our comprehension of these magmas, while petrogenetic models based on whole-rock compositions may lead to biased interpretations.

Phase equilibria and volumetric properties of mixtures of highly fluorinated alcohols and water

New thermodynamic data are reported for aqueous solutions of highly fluorinated alcohols of different chain lengths. The liquid-liquid equilibrium (LLE) T-x diagram of the binary mixture (1H,1H-perfluoropropanol + water) was determined, as well as the LLE phase diagram of the ternary mixture (1H,1H-perfluoropropanol + 1-propanol + water) at 298.15 K and atmospheric pressure. The mutual solubilities of water with several linear perfluorinated alcohols (CF3(CF2)nCH2OH, n = 1–5) and the tertiary alcohol perfluoro-t-butanol ((CF3)3COH) were also measured at 298.15 K. Finally, volumetric properties such as the excess molar volumes and partial molal volumes at infinite dilution of the different fluorinated alcohols in water were also determined and discussed comparing with equivalent data from the literature for the corresponding hydrogenated alcohols.

Integrating different fidelity models for process optimization: A case of equilibrium and rate-based extractive distillation using ionic liquids

We integrate equilibrium and rate-based models to formulate a hybrid optimization scheme for designing an ionic liquid-based extractive distillation process for mixed-refrigerant separation. The equilibrium model assumes vapor–liquid equilibrium at each stage but challenges arise with low-volatility, high-viscosity solvents, which drive the system away from equilibrium. The rate-based approach considers mass and heat transfer rates, giving more accurate representation. We compare the two models for separating R-410A, an azeotropic mixture of R-32 and R-125, using [EMIM][SCN] ionic liquid as entrainer. Analyzing over 4300 simulations with various dimensionality reduction and topological analysis techniques, we find that predictions from the two models exhibit similar trends, but the overestimation in equilibrium-based purities sometimes leads to infeasible process designs. The proposed optimization algorithm thus combines the strengths of the two models to locate feasible and optimal designs.

Machine learning boosted eutectic solvent design for CO2 capture with experimental validation

AbstractAlthough eutectic solvents (ESs) have garnered significant attention as promising solvents for carbon dioxide (CO2) capture, systematic studies on discovering novel ESs linking machine learning (ML) and experimental validation are scarce. For the reliable prediction of CO2‐in‐ES solubility, ensemble ML modeling based on random forest and extreme gradient boosting with inputs of COSMO‐RS derived molecular descriptors is rigorously performed, for which an extensive experimental CO2‐in‐ES solubility database of 2438 data points in 162 ESs involving 106 ES systems are collected. With the best‐performing model obtained, the CO2 solubilities of 4735 novel combinations of ES components are first predicted for estimating their potential in CO2 capture. The top‐ranked candidate combinations are subsequently evaluated by examining the environmental health and safety properties of individual components and assessing the potential operating window based on solid–liquid equilibrium (SLE) prediction. Three most promising ES systems are finally retained, which are thoroughly studied by SLE and CO2 absorption experiments.

Can liquid-liquid equilibria be predicted by the combination of a cubic equation of state and a [formula omitted] model not suitable for liquid-liquid equilibria?

In modern versions of cubic equations of state (EoS), the mixing rules for EoS parameters are derived from an activity coefficient model using either the Huron-Vidal or the Zero Reference Pressure (ZRP) approach. As it is a fact that Wilson's activity coefficient model cannot predict liquid-liquid equilibria (LLE), this article attempts to answer the question: if Wilson's model is coupled with a cubic EoS, is the resulting model capable of predicting LLE?This question is actually becoming increasingly important as recent EoS rely on such a coupling (e.g., the tc-PR EoS). We show that although Wilson's model is mathematically unable to predict instable liquid phases, this is not true for Wilson-EoS models (i.e., EoS incorporating Wilson's model). However, it is also shown that the capacity of Wilson-EoS to predict LLE depends not only on the approach chosen (Huron-Vidal or ZRP) but also on mixture characteristics (such as the ratio of covolumes, the ratio of critical attractive parameters, the binary interaction parameters etc.).

Multiphase Behavior of the Water + 1-Butanol + Deep Eutectic Solvent Systems at 101.3 kPa

The growing demand for more sustainable routes and processes in the mixture separation and purification industry has generated a need to search for innovations, with new solvent alternatives being a possible solution. In this context, a new class of green solvents, known as deep eutectic solvents (DESs), has been gaining prominence in recent years in both academic and industrial spheres. These solvents, when compared to ionic liquids (ILs), are more environmentally friendly, less toxic, low-cost, and easier to synthesize. In addition, they have significantly lower melting points than their precursors, offering a promising option for various applications in this industrial sector. Understanding and studying the thermodynamic behavior of systems composed of these substances in purification and separation processes, such as liquid–liquid extraction and azeotropic distillation, is extremely important. This work aimed to study the phase behavior of liquid–liquid equilibrium (LLE) and vapor–liquid equilibrium (VLE) of water + 1-butanol + DES (choline chloride + glycerol) systems with a molar ratio of 1:2. Experimental LLE data, obtained at 298.15 K and 101.3 kPa, and VLE data, obtained at 101.3 kPa and in the temperature range of 364.05 K–373.85 K, were submitted to the thermodynamic quality/consistency test, proposed by Marcilla et al. and Wisniak, and subsequently modeled using the gamma–gamma approach for the LLE and gamma–phi for the VLE. The non-random two-liquid (NRTL) model was used to calculate the activity coefficient. The results are presented for the VLE in a temperature–composition phase diagram (triangular prism) and triangular phase diagrams showing the binodal curve and tie lines (LLE). The separation and distribution coefficients of LLE were determined to evaluate the extractive potential of the DES. For the VLE, the values of the relative volatility of the system were calculated, considering the entrainer free-basis, to evaluate the presence or absence of azeotropes in the range of collected points. From these data, it was possible to compare DES with ILs as extracting agents, using data from previous studies carried out by the research group. Therefore, the results indicate that the NRTL model is efficient at correlating the fluid behavior of both equilibria. Thus, this study serves as a basis for future studies related to the understanding and design of separation processes.