Solubility Curves Research Articles

Equilibrium solubility and computational modeling of binary system for the 2-(diethylamino)ethyl acrylate and 2-(diethylamino)ethyl methacrylate by pressurized carbon di-oxide

A synthetic methodology has been employed to explore the phase behavior characteristics of solution mixtures containing 2-(diethylamino)ethyl acrylate and 2-(diethylamino)ethyl methacrylate with supercritical CO2 under high-pressure conditions. This investigation covers a wide spectrum of temperatures and pressures, up to 393.2 K and 21.86 MPa, respectively. Specifically, the phase equilibria for the CO2 + 2-(diethylamino)ethyl acrylate and CO2 + 2-(diethylamino)ethyl methacrylate binary systems were investigated. In both of these binary systems, critical mixed curves with maximum peak in the pressure–temperature domain were distinctly observed. This peak was situated amidst the critical temperatures of CO2 and the associated constituent, which is either 2-(diethylamino)ethyl acrylate or 2-(diethylamino)ethyl methacrylate. It is noteworthy that both of these binary systems validate a type-I phase behavior.In the theoretical analysis, solubility curves were generated using the Peng-Robinson equation of state and van der Waals mixing rules. The comparison between the projected and experimental outcomes for the CO2 + 2-(diethylamino)ethyl acrylate and CO2 + 2-(diethylamino)ethyl methacrylate binary systems showed a significant level of concurrence, highlighting the efficacy of the Peng-Robinson equation of state.

Solubility of dapsone in deep eutectic solvents: Experimental analysis, molecular insights and machine learning predictions.

Dapsone (DAP) is an anti-inflammatory and antimicrobial active pharmaceutical ingredient used to treat, e.g., AIDS-related diseases. However, low solubility is a feature hampering its efficient use. First, deep eutectic solvents (DES) were used as solubilizing agents for DAP as an alternative to traditional solvents. Second, intermolecular interactions in the systems were described and quantified. Finally, the solubility prediction model, previously created using the machine learning protocol, was extended and improved using new data obtained for eutectic systems. New DES were created by blending choline chloride (ChCl) with 6 selected polyols. The solubility of DAP in these solvents was measured spectrophotometrically. The impact of water dilution on the solubility curve was investigated. Experimental research was enriched with theoretical interpretations of intermolecular interactions, identifying the most probable pairs in the systems. Dapsone self-association and its ability to interact with components of the analyzed systems were considered. Thermodynamic characteristics of pairs were utilized as molecular descriptors in the machine learning process, predicting solubility in both traditional organic solvents and the newly designed DES. The newly formulated solvents demonstrated significantly higher efficiency compared to traditional organic solvents, and a small addition of water increased solubility, indicating its role as a co-solvent. The interpretation of the mechanism of DAP solubility highlighted the competitive nature of self-association and pair formation. Thermodynamic parameters characterizing affinity were instrumental in developing an efficient model for theoretical screening across diverse solvent classes. The study emphasized the necessity of retraining models when introducing new experimental data, as exemplified by enriching the model with data from DES. The research showcased the efficacy of developing new DES for enhancing solubility and creating environmentally and pharmaceutically viable systems, using DAP as an example. Molecular interactions proved valuable in understanding solubility mechanisms and formulating predictive models through machine learning processes.

Equilibrium of the solubility isotherm in systems Cobalt(II) chloride-glutamic acid-water

The study is focused on the interaction between glutamic acid and hexavodic cobalt chloride. The solubility curve, influenced by the high solubility of the initial components, extends horizontally along a catheter corresponding to the cobalt chloride content. The secretion of glutamic acid exhibits a gradual increase over a relatively extended period. As the cobalt chloride concentration in the solution reaches 25.04%, a new phase emerges, resulting from the molecular interaction of the reactants, forming a double dihydrous compound comprising one molecule of glutamic acid and cobalt chloride: C5H9NO4∙CoCl2.

Crystallization separation of Na2CO3 and Na2MoO4 from the high-salinity ash slag produced by production process of Na2MoO4 based on the theory of phase equilibrium

High-salinity ash slag containing Na2CO3 and Na2MoO4 produced from the production process of Na2MoO4 brings about the resource waste and environmental pollution issues. To realize the resource utilization of these high-salinity ash slag, the phase equilibrium data of the ternary Na2CO3–Na2MoO4–H2O system at 298.15 K and 323.15 K were determined using the isothermal dissolution equilibrium method, and the equilibrium solid phase was determined by X-ray diffraction. By comparing the phase diagrams of the ternary Na2CO3–Na2MoO4–H2O system at 298.15 K, 323.15 K, and 353.15 K, the change rules of the crystallization region were analyzed. The Pitzer and HW models were used to calculate the ionic interaction parameters of θMoO4–CO3 and ψNa–MoO4–CO3, which could be further used to predict the solubility curves of the ternary Na2CO3–Na2MoO4–H2O system. The calculation results were in good agreement with the experimental results. Furthermore, the phase diagrams of the ternary Na2MoO4–Na2CO3–H2O system at 298.15 K and 353.15 K were selected to design a process for the highly-efficient recovery of Na2MoO4·2H2O and Na2CO3·H2O from the high-salinity ash slag. The experimental results showed that the one-way recovery rate of Na2CO3 could reach 92.55%, with a purity of 99.62%, and that of Na2MoO4·2H2O is 45.61%, with a purity of 99.14%. These results were almost consistent with the theoretical calculation results. After multiple cycles, Na2CO3 and Na2MoO4 could be completely recovered.

Phase equilibria of binary and ternary mixtures with poly(styrene-co-hexafluorobutyl methacrylate) and solvents at high pressure and temperature

This paper presents the synthesis of the fluoric copolymer poly(styrene-co-2,2,3,4,4,4-hexafluorobutyl methacrylate) [P(styrene-co-HFBMA)] through dispersed phase polymerization in a supercritical carbon dioxide (sc-CO2) medium. The physiochemical characteristics of P(styrene-co-HFBMA) were extensively studied by varying the styrene to HFBMA mole ratios (40:1, 25:1, and 20:1) and 2,2'-Azobisisobutyronitrile (AIBN) initiator at different mass percentages (mass%) from 1 to 4, along with the mean molecular mass (Mm). Phase transition data were reported for two-component and three-component P(styrene-co-HFBMA) in sc-C3H8, C3H6, C4H10, and C4H8, encompassing temperature “T” and pressure “P” limits (∼341 to ∼459) K, and (∼21 to ∼185) MPa, respectively. The phase behavior of the P(styrene-co-HFBMA) + solvent mixtures displayed an upper critical solution temperature (UCST) type behavior with a declining gradient. Equilibria curves were measured for the P(styrene-co-HFBMA) + (C3H10/C3H6) + CH3OCH3(i.e., DME) (25:1, AIBN mass%: 2.0) system in “P-T” phase diagram, spanning from the UCST region to LCST region at DME mass% ranging from 0.0 to 68.5. Additionally, solubility curves at “P”: up to ∼148 MPa and “T”: from ∼450 K to ∼350 K showed a shift from a declining slope to an inclined slope within the 0.0 to 60.3 mass% range for the P(styrene-co-HFBMA) (mole ratio:25:1; AIBN mass%: 2.0) + (C4H10/C4H8) + DME system. These findings provide valuable insights into the phase behavior and solubility characteristics of the P(styrene-co-HFBMA) copolymer in different sc-solvent mixtures.

Chemical stability of Pb[(UO2)2O2(OH)2](H2O) and Pb2[(UO2)5O6(OH)2](H2O)2 compounds in aqueous solutions

The chemical stability of Pb[(UO2)2O2(OH)2](H2O) and Pb2[(UO2)5O6(OH)2](H2O)2 compounds in aqueous solutions was studied. The acid-base boundaries of the existence of these compounds in aqueous solutions were established, the hydrolysis products were identified, and the solubility was determined. Based on the data obtained, the equilibrium constants of dissolution reactions, the Gibbs functions of the formation and dissolution of Pb[(UO2)2O2(OH)2](H2O) and Pb2[(UO2)5O6(OH)2](H2O)2, were calculated, the solubility curves of the compounds under study, and the phase diagrams of U(VI) and Pb(II) in saturated aqueous solutions and in equilibrium solid phases were calculated.

Dissociation line and driving force for nucleation of the nitrogen hydrate from computer simulation

In this work, we determine the dissociation line of the nitrogen (N2) hydrate by computer simulation using the TIP4P/Ice model for water and the TraPPE force field for N2. We use the solubility method proposed recently by some of us to evaluate the dissociation temperature of the hydrate at different pressures, from 500 to 1500 bar. Particularly, we calculate the solubility of N2 in the aqueous solution when it is in contact with a N2-rich liquid phase and when in contact with the hydrate phase via planar interfaces as functions of temperature. Since the solubility of N2 decreases with temperature in the first case and increases with temperature in the second case, both curves intersect at a certain temperature that determines the dissociation temperature at a given pressure. We find a good agreement between the predictions obtained in this work and the experimental data taken from the literature in the range of pressures considered in this work. From our knowledge of the solubility curves of N2 in the aqueous solution, we also determine the driving force for nucleation of the hydrate, as a function of temperature, at different pressures. In particular, we use two different thermodynamic routes to evaluate the change in chemical potential for hydrate formation. Although the driving force for nucleation slightly decreases (in absolute value) when the pressure is increased, our results indicate that the effect of pressure can be considered negligible in the range of pressures studied in this work. To the best of our knowledge, this is the first time the driving force for nucleation of a hydrate that exhibits crystallographic structure sII, along its dissociation line, is studied from computer simulation.

Thermodynamic phase equilibria containing sodium, potassium, magnesium, strontium and chloride in underground brine environment and evaporation and salt precipitation behavior of strontium chloride

The isothermal dissolution equilibrium method was employed to study the thermodynamic phase equilibria of the NaCl + KCl + MgCl2 + SrCl2 + H2O system at 298.2 K. The equilibrium solubilities and solid phase compositions of the quinary system at 298.2 K were determined by chemical analysis and X-ray diffraction, and the corresponding stable phase diagrams were drawn. The phase diagram of the quinary system has three invariant points, six solid phase crystallization fields and fifteen solubility curves. In the phase diagram, crystalline area of double salt KCl·MgCl2·6 H2O existed. Moreover, the Pitzer thermodynamic model was utilized to predict the phase equilibria of the quinary system at 298.2 K, and the predicted solubilities agreed well with the experimental values. The results demonstrate that the Pitzer model can accurately describe the thermodynamic properties in the quinary system at 298.2 K. Finally, based on the advantages of rich strontium in underground brine from Longnu Temple brine-bearing structure in Sichuan basin of China, the salt precipitation law of strontium chloride was studied.

EFFECTIVENESS OF 7S GLOBULIN AGAINST BOTRYTIS CINEREA CAUSING GRAY MOLD IN STRAWBERRY

Gray mold caused by Botrytis cinerea is the most harmful postharvest disease responsible for the degradation of strawberries. The presented study targeted the preparation of 7S globulin from pea seeds to serve as an antifungal agent against B. cinerea in vitro and on the post-harvest strawberry to extend the fruits’ shelf life. The 7S globulin isolation from pea seeds and characterization employed various methods, such as SDS-PAGE, FTIR, and pH solubility curve. The molecular technique also helped confirm the identity of the causative microorganism of the gray mold disease in strawberries. Utilizing rRNA gene sequencing identified a fungal pathogen that causes gray mold as B. cinerea. The 7S globulin showed three protein bands corresponding to α/ (83 KDa), α (68 KDa), and β (60 KDa) subunits. The isoelectric point was notable at pH 5.8. The essential and non-essential amino acids occurred around 24.92% and 54.04%, respectively. The 7S globulin inhibited the mycelial growth of B. cinerea in a concentration-dependent manner. The Scanning Electron Microscope (SEM) of B. cinerea subjected to 7S globulin showed swelling of both the fungal hyphae and conidia, significantly affected by the pea 7S-globulin treatment, entirely destabilizing and deforming their shape at 0.4 g/L. The 7S-globulin exposure maintained the fruit quality and stopped the strawberry’s natural deterioration. Results further authenticated that 7S globulin (isolated from pea seeds) revealed effective antifungal action against B. cinerea mycelial development via a membrane-targeted mechanism. The 7S globulin affects hyphal morphology, compromises plasma membrane integrity, and prevents post-harvest gray mold on strawberry fruits.

Extraction of proteins from aqueous and salt solutions of porcine edible byproducts using the pH-shifting technique

The use of aqueous and saline solution and the treatment with sodium nitrite in the protein extraction by the pH-shifting technique of edible pig byproducts (heart and liver) were evaluated. Protein solubility curves were obtained, and the optimal pH of solubility (PS) and precipitation (isoelectric point, pI) were defined. The addition of salt increases the solubility in alkaline pH (11.0) for both byproducts, being set at 2.0 for the liver and 3.0 for the heart. The precipitation yields of the total protein were lower in the aqueous heart extracts (71.75%) than in the other extracts (84.23%), but the precipitation yield of total heme pigments (77.63%) was not affected by the treatments or byproduct type. The yield of protein recovery was higher in liver extracts (68.04%) than in heart extracts (49,98%), regardless of the extraction solution used. The increasing additions of nitrite increased the levels of residual nitrite (NO2R) on the precipitates, but lower additions were enough to favor the formation of the pinkish-red color characteristic of cured meat products, by increasing the redness (a*) and reducing the hue angle (h) color. Higher values of NO2R and a* and lower values of h were also observed in the precipitates extracted by the saline solution when compared to those obtained by the aqueous solution. Thus, the use of saline solutions supplemented with 20 mg/mL sodium nitrite proved to be a viable alternative in protein recovery processes in pig byproducts, especially in livers, being a promising alternative to development of techno-functional ingredients to use in meat products.

Nanosize Dependence of the Mutual Solubility in the Solid State in the Mo–Ru Metal System

Abstract—The present work is devoted to constructing a method for calculating the solubility curves of molybdenum and ruthenium in the solid state in the binary Mo–Ru system with consideration of nanoscale effects. The approach is based on the thermodynamics of phase equilibria, taking into account the surface phenomena within the framework of the Gibbs thermodynamic method of separating surfaces. The surface tension is chosen as such a separating surface. The calculations of solubility were performed taking into account the dimensional dependences of the individual characteristics of metals and the parameters of interparticle interaction in the phases. A good agreement of the obtained results with the available experimental data for the macroscopic case is observed.

Investigation on solid–liquid equilibrium behavior of 4-cyanobenzoic acid in fourteen mono-solvents: Determination, correlation, molecular simulation and thermodynamic analysis

4-Cyanobenzoic acid (4-CyBZA) is an important pharmaceutical intermediate, and the research on solubility behavior of 4-CyBZA in organic solvents is very necessary for its crystallization and separation processes. Therefore, this study aimed at exploring dissolution behavior of 4-CyBZA in several pure solvents via experiment, calculation, and simulation process. In this study, mole-fraction solubility values of 4-CyBZA in fourteen common solvents including four low alcohols (methanol (MeOH), ethanol (EtOH), n-propanol (NPOH), n-butanol (NBOH)), four acetates (methyl acetate (MeAC), ethyl acetate (EtAC), n-propyl acetate (NPAC), n-butyl acetate (NBAC)), two alcohol ethers (2-ethoxyethanol (EGEE), 2-methoxyethanol (EGME)) as well as four common heteroatom/heterocyclic solvents (acetonitrile (MeCN), N,N-dimethylformamide (DMF), N-methylpyrrolidone (NMP), 1,4-dioxane (Diox)) were critically measured by using laser monitoring method from 278.15/288.15 K to 323.15 K under 100 kPa. Interestingly, experimental results indicated that an increase in temperature facilitated the dissolution of 4-CyBZA in selected 14 solvents. At the same time, the solubility curve underwent a crossover phenomenon. At 298.15 K, the common order of 4-CyBZA solubility was: DMF > EGME > EGEE > NMP > Diox > MeOH > MeAC > EtOH > EtAC > NPAC > NPOH > NBOH > NBAC > MeCN. The Hansen solubility parameter (HSP) was introduced to analyze solubility behavior via molecular similarity between 4-CyBZA and chosen solvents. Molecular modeling including Hirshfeld surface (HS) analysis and molecular electrostatic potential surface (MEPS) were employed to understand internal interactions within 4-CyBZA crystals. Moreover, solubility was fitted by Margules model, NRTL model, NRTL-SAC model, UNIQUAC model as well as a combined model (Jouyban model). Results showed that NRTL and NRTL-SAC model were more suitable for correlating 4-CyBZA solubility with absolute temperature. Furthermore, given the high accuracy of the NRTL model, dissolution thermodynamic characteristics of 4-CyBZA in chosen solvents were analyzed by NRTL model, which revealed that the dissolving process and mixing process were spontaneous and entropy-driven.

Thermodynamic prediction of complex hydration processes and verification by experiments for the Ca-Al-C (CA, calcite, water) and Ca-Al-S (ye'elimite, gypsum, water) systems

The solubility of relevant phases in the calcium aluminate cements with limestone and in calcium sulfoaluminate cements with gypsum indicate several potential phase assemblages which might be formed during hydration. Thermodynamic calculations and pore solution data indicate that initially the solution is oversaturated with respect to several phases and thermodynamically metastable phase combinations may form. Some initially formed metastable phase assemblages contain more phases than predicted by the Gibbs phase rule and gain less Gibbs free energy than the stable phase assemblage. Solubility curves are used to define potential phase assemblages, the associated potential Gibbs free energy gain, to plot possible kinetic paths and to evaluate their respective probability. If different kinetic paths are conceivable, the reaction occurs along the solubility of the initially formed stable phases, namely monocarbonate in the calcium aluminate and ettringite in calcium sulfoaluminate system.

Thermodynamic study for the (butyl, hexyl and octyl) acetoacetate under high pressure CO2

Understanding the phase behavior of binary liquid mixtures containing butyl acetoacetate, hexyl acetoacetate, and octyl acetoacetate under high-pressure supercritical CO2 (sc-CO2) is essential for several applications. The solubility curves for these binary mixtures have been investigated at different temperature and pressure ranges, specifically between 313.2 K and 393.2 K and 2.39 MPa to 23.83 MPa. The three systems, namely butyl acetoacetate, hexyl acetoacetate, and octyl acetoacetate in high-pressure sc-CO2, exhibit critical mixture curves and a maximum in pressure–temperature (P, T) diagrams between the critical point of butyl acetoacetate/hexyl acetoacetate/octyl acetoacetate and carbon dioxide. These characteristics of the critical mixture plot fall under the category of type-I behavior.The Peng-Robinson equation, which utilizes van der Waals mixing rules and two interaction parameters, is employed to correlate experimental solubility curves and critical mixture curves of the aforementioned three systems. The root mean square deviation percentage (RMSD%) is calculated at each temperature (using temperature-dependent adjusted parameters) for the butyl acetoacetate + sc-CO2, hexyl acetoacetate + sc-CO2, and octyl acetoacetate + sc-CO2 systems, and it ranges from 3.11% to 5.92%, 2.09% to 3.97%, and 1.70% to 3.02%, respectively.

Measurements and predictions of phase equilibria in quinary system NaCl + KCl + MgCl2 + SrCl2 + H2O (saturated with NaCl) at 308.2 K

AbstractSichuan Basin of China is a typical underground brine enrichment area. In order to develop and utilize the brine resource, it is necessary to study the phase equilibria and phase diagram of brine systems. In this work, the phase equilibria of the quinary system NaCl + KCl + MgCl2 + SrCl2 + H2O (saturated with NaCl) at 308.2 K of the underground brines in Sichuan Basin are measured experimentally by isothermal dissolution equilibrium method. The phase diagram, water content diagram, and sodium chloride content change diagram of the quinary system with NaCl saturated are also drawn, respectively. The results show that the phase diagram of the quinary system contains three invariant points, seven isothermal solubility curves, and five solid crystal zones at 308.2 K. In the phase diagram, the KCl crystallization area is the largest, followed by SrCl2·6H2O, KCl·MgCl2·6H2O, and SrCl2·2H2O, while MgCl2·6H2O has the smallest crystallization area. Magnesium chloride in the quinary system has the largest solubility and has strong salting‐out effect on other salts. Furthermore, the unreported mixed ion interaction parameters θMg, Sr and ΨMg, Sr, Cl of Pitzer model are fitted, respectively. Consequently, the solubilities of the quinary system NaCl + KCl + MgCl2 + SrCl2 + H2O at 308.2 K are predicted using the Pitzer model, and the calculated phase diagram at 308.2 K is also plotted in detail. The predicted solubilities of the quinary system were in good agreement with the experimental solubilities. Finally, the study on the phase equilibrium of the quinary system can provide phase equilibrium data for the development and utilization of liquid mineral resources.

Phase equilibria for the two-component systems of allyl acetoacetate, methyl acetoacetate and ethyl acetoacetate under high-pressure CO2

The phase behavior study of allyl acetoacetate, methyl acetoacetate, and ethyl acetoacetate in supercritical CO2 (S-CO2) is important for several industrial processes. This study investigated the binary mixture solubility curves of the three systems (allyl acetoacetate, methyl acetoacetate, and ethyl acetoacetate) at five temperature sets (313.2–393.2 K) and pressures (3.09 ≤ p ≤ 20.78 MPa). In S-CO2, the three systems exhibited a critical mixture curves and the maximum point in pressure–temperature (p-T) diagram was obtained between critical point of allyl acetoacetate/methyl acetoacetate/ethyl acetoacetate and that of CO2. These characteristics of the critical mixture plot fall under the category of type-I behavior. The experimental solubility curves and critical mixture curves of above three systems are correlated using Peng-Robinson equation of state with van der Waals mixing rules using two interaction parameters. The calculated root mean square relative deviation % (RMSD %) of the allyl acetoacetate + S-CO2, methyl acetoacetate + S-CO2, and ethyl acetoacetate + S-CO2 systems for five temperature sets ranges from (1.29% − 3.63%), (1.47% − 8.95%) and (2.17% − 3.87%), respectively.

Fundamental Properties of Ammonia Borane Aqueous Solution: Dissolution Enthalpy of Solution, Freezing Points and Solubility Curve, Thermal analysis, Stability and Phase Diagram

Fundamental Properties of Ammonia Borane Aqueous Solution: Dissolution Enthalpy of Solution, Freezing Points and Solubility Curve, Thermal analysis, Stability and Phase Diagram

Understanding the thermodynamic phase equilibria for the allyl acetate, allyl acrylate and allyl methacrylate under CO2 as supercritical solvent

Acrylic acid allyl ester groups show the non-ideal phase equilibria and have slightly or strong polarity. Phase equilibria for the allyl acetate, allyl acrylate and allyl methacrylate in conformity with chain-length play a crucial role as organic monomers in a number of chemical industries. The curves of the solution mixture for allyl acetate, allyl methacrylate, and allyl acrylate under high-pressure supercritical CO2 (super CO2) are examined with the help of a fabricated method at various temperatures within the boundary of (313.2 −393.2) K and pressures within (1.75–16.27) MPa. The three system for super CO2 + allyl acetate, super CO2 + allyl methacrylate and super CO2 + allyl acrylate solutions have critical mixed curves which show largest in p-T space between Tc (- critical temperatures) of super CO2 and allyl acetate or allyl acrylate or allyl methacrylate. The liquid + vapor data of super CO2 of three systems at a fixed pressure decreases with rise in temperature. The super CO2 + allyl acetate, super CO2 + allyl acrylate and super CO2 + allyl methacrylate systems display phase behavior of type-I. For the application at Peng-Robinson equation in theoretical investigation, solubility curves between the predicted and test results of the super CO2 + allyl acetate, super CO2 + allyl acrylate and super CO2 + allyl methacrylate binary systems were obtained the satisfactory agreement. The properties (pc, Tc and ω) and vapor pressure of allyl acetate, allyl acrylate and allyl methacrylate were estimated with group contribution and useful method.

Solid–Liquid Phase Equilibria of the Quaternary System NaCl–CaCl2–H3BO3–H2O at 323.15 K: Solubility Determination and Thermodynamic Model

The solid–liquid phase equilibria of brine systems containing boric acid are the theoretical basis for the development of boric acid from brine resources. The phase equilibria of the systems NaCl–CaCl2–H3BO3–H2O and CaCl2–H3BO3–H2O at 323.15 K were investigated by the isothermal solution method. The phase diagram for the ternary system is composed of one co-saturation point, two univariant solubility curves, and two singe-salt crystallization fields of CaCl2·2H2O and H3BO3. The dry-salt phase diagram for the quaternary system consists of one invariant point, three univariant solubility curves, and three single-salt crystallization fields for NaCl, CaCl2·2H2O, and H3BO3. In the phase diagrams of the quaternary system at 298.15 and 323.15 K, the areas of sodium chloride and calcium chloride salt regions are enlarged, whereas the area of the H3BO3 region is diminished significantly with the increase of temperature. Using the Pitzer model, the lacking Pitzer parameters for H3BO3 were obtained by fitting the solubilities in the CaCl2–H3BO3–H2O system. The calculated solubilities with the Pitzer model were in accord with the experimental data.

Extractive desulfurization of thiophene by tetraethylene glycol at T = 298.15 to 313.15 K and liquid–liquid phase equilibrium study

ABSTRACT This study provides the complete liquid–liquid equilibrium (LLE) data including the solubility curves and tie-lines for heptane + thiophene + tetraethylene glycol and cyclohexane + thiophene + tetraethylene glycol ternary mixtures at 298.15–313.15 K under a pressure of 83.4 ± 1 kPa. The experimental data were obtained by the cloud point method. Type 1 phase behavior is observed for the systems. The observed behavior was interpreted based on the type and nature of the interactions between the components. The capability of tetraethylene glycol in extractive desulfurization of thiophene from liquid fuel is evaluated by determining the solute distribution coefficient and selectivity. The high values of the selectivity show that tetraethylene glycol is a good candidate for this purpose. The investigation of the effect of temperature on the area of the biphasic region and distribution ratios shows that the extraction process can be performed at room temperature. The experimental data were successfully correlated with the NRTL model. The reliability of the correlation results was checked by using a Graphical User Interface (GUI) for the representation of Gibbs energy of mixing (GM). The root mean square deviation (RMSD), a measure of the precision of the correlations, ranges from 0.0022 to 0.0040.