Vapor–liquid equilibria of the binary mixtures formed by nitromethane with five alkyl alkanoates at 101.3 kPa

Vapor–liquid equilibria were measured at 101.3 kPa, in a range of temperatures from 350.28 to 374.69 K, for five binary mixtures formed by nitromethane with ethyl acetate, propyl acetate, isopropyl acetate, methyl propionate, and ethyl propionate. Calculations of nonideality of the vapor phase were made with Soave–Redlich–Kwong equation of state. Thermodynamic consistency of data was tested via Herington analysis. Two systems show minimum boiling azeotropes. The experimental VLE data were reduced and binary parameters for four liquid models, such as van Laar, Wilson, NRTL and UNIQUAC, were fitted. A comparison of model performances was made by using the criterion of average absolute deviations in boiling point and in vapor-phase composition.     

Liquid–liquid equilibria for mixtures containing water,methanol, fatty acid methyl esters,and glycerol

The liquid–liquid equilibrium (LLE) data, including tie-lines and phase boundaries, were measured for the ternary systems of water + methanol + methyl oleate, water + methanol + methyl linoleate, glycerol + methanol + methyl oleate, and glycerol + methanol + methyl linoleate at temperatures from 298.2 K to 318.2 K under atmospheric pressure. All the LLE data follow the Othmer-Tobias equation. Each ternary system behaves type-I LLE. The areas of two-liquid coexistence region decrease with increasing temperature. The experimental data were applied to test the validity of the UNIFAC model and its modified versions, including UNIFAC-LLE and UNIFAC-Dortmund. The LLE data were also correlated with the NRTL and the UNIQUAC models. The UNIQUAC model yielded better results.     

Vapor–liquid equilibria for binary mixtures containing ethyl tert butyl ether (ETBE) + (p-xylene,m-xylene and ethylbenzene) at 101.3 kPa

Isobaric vapor–liquid equilibria data at 101.3?kPa were reported for the binary mixtures ethyl tert butyl ether (ETBE)?+?(p-xylene, m-xylene and ethylbenzene). VLE experimental data were tested for thermodynamic consistency by means of a modified Dechema test and was demonstrated to be consistent. The activity coefficients were correlated with the Margules, van Laar, UNIQUAC, NRTL, and Wilson equations. The Analytical Solution Of Groups (ASOG) model also was applied for prediction.     

Phase equilibria in the binary mixtures formed by ethylbenzene with some aliphatic alcohols at 95.8 kPa

Phase equilibria are determined over the entire composition range, through measurements on the bubble points of the binary mixtures of ethylbenzene with methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol and tert-butanol. A Swietoslawski-type ebulliometer is used for the measurements. The liquid phase composition versus temperature measurements, found to be well represented by the Wilson model, are used to establish the phase equilibria.     

Vapor–liquid equilibria of selected binary mixtures formed by 2-methylpyrazine at 94.7 kPa

Vapor–liquid equilibria at 94.7?kPa, over the entire composition range are obtained for the binary mixtures formed by 2-methylpyrazine with 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, trichloroethylene, tetrachloroethylene, N,N-dimethylformamide and N,N-dimethylacetamide. A Swietoslawski type ebulliometer is used to measure the bubble point temperatures necessary to determine the vapor–liquid equilibria. The Wilson equation is used to represent measured liquid phase composition versus temperature data.     

Fluid phase topology of ethanol+benzene+cyclohexane at 101.3 kPa

In this article, isobaric vapor–liquid equilibria for the ternary mixture of ethanol?+?benzene?+?cyclohexane was experimentally investigated at atmospheric pressure. Vapor–liquid equilibria data for ethanol?+?benzene?+?cyclohexane at 101.3?kPa were obtained with a Othmer-type ebulliometer. Data were tested and considered thermodynamically consistent. The experimental results showed that this ternary mixture is completely miscible and exhibits three binary homogeneous azeotropes and a ternary minimum azeotrope at the studied conditions. Satisfactory results were obtained for correlation of equilibrium compositions with UNIQUAC activity coefficients model and also for prediction with UNIFAC method. In both cases, low root mean square deviations of vapor mole fraction and temperature were calculated. The capability of ethanol as modified distillation agent at atmospheric condition is discussed in terms of the thermodynamic topological analysis. However, owing to the complex topology of the ternary mixture it leads to a distillation scheme with three columns and difficult operation and thus, ethanol is not recommended as a separating agent for benzene?+?cyclohexane azeotrope.     

Phase diagrams of (vapour + liquid) equilibrium for binary mixtures of α,α,α-trifluorotoluene with ethanol,or benzene,or chloroform at pressure 101.4 kPa

(Vapour + liquid) equilibrium (VLE) of binary mixtures of (ethanol + α,α,α-trifluorotoluene), (benzene + α,α,α-trifluorotoluene), and (chloroform + α,α,α-trifluorotoluene) have been investigated at the pressure 101.4 kPa using the dynamic-ebulliometry method over the whole composition range. The correlated VLE phase diagrams were adequately described by means of NRTL and UNIQUAC thermodynamic models. Fair attractive energies in the first two systems are capable to yield azeotropes, while moderate repulsive energies in the later system make it zeotrope.     

Surface tension of binary and two ternary mixtures containing water–acetonitrile–methanol/ethanol at 298.15 K: experimental data,correlation and prediction by various models

Surface tension of two ternary mixtures of water/acetonitrile/methanol and water/acetonitrile/ethanol, and their constituent binaries, were measured over the whole range of composition at 298.15 K and ambient pressure. The experimental data were used to calculate in the surface tension deviations (Δσ). The negative values of Δσ for the binary and ternary systems indicate the strong hydrogen bonding between unlike molecules of mixtures (particularly in the high concentration of water). Surface tension data of the binary systems were correlated with Fu et al., Wang–Chen, Redlich–Kister and Myers–Scott models. The mean standard deviation obtained from the comparison of experimental and calculated surface tension values for binary systems with four models is less than 0.42. Finally, the concentration dependence of the surface tension deviation of the ternary mixtures at 298.15 K was correlated using Pando et al. and Ku et al. models, with satisfactory results.     

Vapor—liquid equilibria of the binary mixtures methyl chloride — methanol and dimethyl ether — methyl chloride and of the ternary mixture dimethyl ether — methyl chloride — methanol

Vapor Liquid Equilibria in mixtures of dimethyl ether, methyl chloride and methanol were investigated in a static equilibrium apparatus for temperatures 250 K < T <350 K and pressures up to 1 MPa. Temperature, pressure and the composition of the liquid and the vapor phase were determined.The consistency of the binary experimental data was checked and parameters of several g^E-models were fitted. The binary parameters were used to predict the ternary VLE and the calculated results were compared with the experimental data.     

Isobaric vapor–liquid equilibrium of systems containing triethyl orthoformate at 101.3 kPa

Isobaric vapor–liquid equilibrium data of ethanol(1)-triethyl orthoformate(2), benzene(1)-triethyl orthoformate(2) and ethanol(1)-benzene(2)-triethyl orthoformate(3) were measured at 101.3 kPa and under a wide range of temperatures (349–420 K), using the Rose–Williams still modified by the authors. The experimental data of binary systems were tested for thermodynamic consistency with the method of Fredenslund and coworkers and correlated satisfactorily with SRK equation and PR equation of state. The VLE data of ethanol(1)-benzene(2)-triethyl orthoformate(3) ternary system were tested with the method of McDermont–Ellis and were predicted with the parameters of SRK and PR equation of state obtained from binary systems.     

Viscometric and volumetric properties of benzene + methyl acetate,or + methyl propanoate,or + methyl butanoate binary systems at 283.15, 298.15 and 313.15 K

Viscosities and densities of three binary liquid mixtures, benzene?+?methyl acetate, benzene?+?methyl propanoate and benzene?+?methyl butanoate, have been measured at 283.15, 298.15 and 313.15?K, and atmospheric pressure. From experimental data, viscosity deviation, excess energy of activation for viscous flow, and excess molar volume were calculated and satisfactorily correlated with Redlich and Kister equation. Empirical and semiempirical equations and the predicted group-contribution method, universal automatic computer, were applied.     

Phase equilibria in binary subsystems of urea–biuret–water system

Joint results of the differential scanning calorimetry (DSC) and thermogravimetry (TG) experiments were the basis for the fusion enthalpy and temperature determination of the biuret (NH₂CO)₂NH (synthesis by-product of the urea fertilizer (NH₂)₂CO). Recommended values are Δ_m H = (26.1 ± 0.5) kJ mol⁻¹, T _m = (473.8 ± 0.4) K. The DSC method allowed for the phase diagrams of “water–biuret,” “water–urea,” “urea–biuret” binary systems to be studied; as a result, liquidus and solidus curves were precisely defined. Stoichiometry and decomposition temperature of the biuret hydrate identified, composition of the compound in “urea–biuret” system was suggested.     

Liquid–liquid equilibria for butyl tert-butyl ether + (methanol or ethanol) + water at several temperatures

Liquid–liquid equilibrium (LLE) data for butyl tert-butyl ether + (methanol or ethanol) + water were measured experimentally at 298.15, 308.15 and 318.15 K. The experimental data were correlated with the NRTL and UNIQUAC equations. The equations were used to perform the correlation of each temperature data set and for the three temperatures data set simultaneously. The best results were found with UNIQUAC and NRTL (α = 0.1), respectively. Data prediction was carried out using the UNIFAC method, however the results found were not quantitative.     

Transport of binary water–ethanol mixtures through a multilayer hydrophobic zeolite membrane

Transport of water–ethanol mixtures through a hydrophobic tubular ZSM-5 (Si/Al = 300) zeolite membrane during pervaporation was studied experimentally and theoretically. The zeolite membrane was deposited on a support made of pure titania coated with three intermediate ceramic titania layers. The influence of feed concentration, feed temperature and permeate pressure on permeate fluxes and permeate concentrations was investigated in a wide range. Dusty gas model parameters of the support and all ceramic intermediate layers were calculated on the basis of gas permeation data. Mass transfer resistances and pressure drops in the different membrane layers during pervaporation were calculated for several process conditions. In particular the influence of the undesired but unavoidable pressure drop in the support and the intermediate layers on the effective driving force for pervaporation was evaluated and found to be relevant for predicting the overall process performance. The membrane prepared was found to be suitable for the recovery of highly concentrated ethanol from feed mixtures of relatively low ethanol concentrations at relatively low feed temperatures.     

Activity coefficients of the binary mixtures of n-decane with some aliphatic alcohols at 95.8 kPa

Activity coefficients at 95.8?kPa (over the whole composition range) are evaluated from the measurements on the bubble point temperatures of the binary mixtures of n-decane with: iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol and active amylalcohol. A Swietoslawski-type ebulliometer is used for the measurements. The Wilson model, found to represent the liquid phase composition versus temperature data well, is used for the calculations.     

Solubility of minoxidil in binary mixture of ethanol + water at various temperatures

ABSTRACT

The solubility of minoxidil in the aqueous binary mixtures of ethanol at different temperature are investigated and the obtained solubility data are fitted by using some cosolvency models including van’t Hoff equation, Yalkowsky model, Jouyban–Acree model and Jouyban–Acree–van’t Hoff model. The mean relative deviations (MRD%) are used to illustrate the models performance. Moreover, the apparent entropy, enthalpy, and Gibbs free energy of minoxidil dissolution process in the investigated solvent mixtures are computed using van’t Hoff and Gibbs equations. Finally, by means of the inverse Kirkwood–Buff integrals preferential solvation of minoxidil by water is observed in water-rich and ethanol-rich mixtures.     

Solubility of anthracene in binary alkane + ethanol solvent mixtures at 298.15 K

Experimental solubilities are reported for anthracene in six binary alkane?+?ethanol solvent mixtures at 298.15?K. The alkane solvents studied were hexane, heptane, octane, cyclohexane, methylcyclohexane and 2,2,4-trimethylpentane. Results of these measurements were used to test a mathematical representation based on the combined nearly ideal binary solvent (NIBS)/Redlich–Kister equation. For the six systems studied, the combined NIBS/Redlich–Kister equation was found to accurately describe the experimental data, with an average absolute deviation between measured and back-calculated values being approximately ±0.5%.     

Excess molar volumes of binary mixtures of 2,2,2-trifluoroethanol with water,or acetone,or 1,4-difluorobenzene,or 4-fluorotoluene,or α,α,α, trifluorotoluene or 1-alcohols at a temperature of 298.15 K and pressure of 101 kPa

Excess molar volumes V_m^E of binary mixtures of 2,2,2-trifluoroethanol with water, or acetone, or methanol, or ethanol, or 1-alcholos, or 1,4-difluorobenzene, or 4-fluorotoluene or α,α,α-trifluorotoluene were measured in a vibrating tube densimeter at temperature 298.15 K and pressure of 101 kPa. The V_m^E extrema are: 1.540 cm³ · mol⁻¹ for (2,2,2-trifluoroethanol + 1-heptanol); 1.452 cm³ · mol⁻¹ for (2,2,2-trifluoroethanol + 1-hexanol); 1.238 cm³ · mol⁻¹ for (2,2,2-trifluoroethanol + 1-butanol); 0.821 cm³ · mol⁻¹ for (2,2,2-trifluoroethanol + 4-fluorotoluene); 0.817 cm³ · mol⁻¹ for (2,2,2-trifluoroethanol + ethanol); 0.647 cm³ · mol⁻¹ for (2,2,2-trifluoroethanol + methanol); 0.618 cm³ · mol⁻¹ for (2,2,2-trifluoroethanol + acetone); 0.605 cm³ · mol⁻¹ for (2,2,2-trifluoroethanol + α,α,α-trifluorotoluene); 0.485 cm³ · mol⁻¹ for (2,2,2-trifluoroethanol + 1,4-difluorobenzene); and −0.656 cm³ · mol⁻¹ for (2,2,2-trifluoroethanol + water). The limiting excess partial molar volumes are estimated.     

Solid and liquid phase equilibria and solid-hydrate formation in binary mixtures of water with amines

Solid and liquid phase diagrams have been constructed for {water+triethylamine,or+N,N-dimethylformamide(DMF) or+N,N-dimethlacetamide (DMA)} Solid-hydrates form with the empirical formulae N(C2H5)3 3H2O,DMF 3H2O,DMF 2H2O,DMA 3H2O and (DMA)2 3H2O.All are congruently melting except the first which melts incongruently.The solid-hydrate formation is attributed to hydrogen bond.The results are compared with the references