Vapor — liquid and vapor — liquid — liquid phase equilibria of binary and ternary systems of nitrogen,ethene and methanol: Experiment and data evaluation

Zeck, S. and Knapp, H., 1986. Vapor—liquid and vapor—liquid—liquid phase equilibria of binary and ternary systems of nitrogen, ethene and methanol: experiment and data evaluation. Fluid Phase Equilibria, 26: 37–58.VLE and VLLE of three binary and one ternary system containing the components N₂, C₂H₄ and CH₃OH are investigated in a high-pressure phase equilibrium apparatus with vapor recirculation at temperatures 240 < T < 298 K and pressures 4 < p < 100 bar. Immiscibilities in the liquid phase are observed in the binary system C₂H₄CH₃OH with a lower critical end point and in the ternary system N₂C₂H₄CH₃OH.The experimental results are reported and compared with the results of other investigators and of available correlations.     

Vapor–liquid equilibria and excess properties of octane + 1,1-dimethylpropyl methyl ether (TAME) mixtures

Vapor–liquid equilibrium (VLE) data are reported for the binary mixtures formed by octane and the branched ether 1,1-dimethylpropyl methyl ether (tert-amyl methyl ether or TAME). A Gibbs–van Ness type apparatus was used to obtain total vapor pressure measurements as a function of composition at 298.15, 308.15, 318.15 and 328.15 K. The system shows positive deviations from Raoult’s law. These VLE data are analyzed together with data previously reported for octane+TAME mixtures: VLE data at 323.15 and 423.15 K, excess enthalpy (H_m^E) data at 298.15 and 313.15 K and excess volume (V_m^E) data at 298.15 K. The UNIQUAC model, the lattice–fluid (LF) model, and the Flory theory are used to simultaneously correlate VLE and H_m^E data. The two latter models are then used to predict V_m^E data. The original UNIFAC group contribution model and the modified UNIFAC (Dortmund model) are used to predict VLE data.     

Vapor—liquid and vapor—liquid—liquid phase equilibria for binary and ternary systems for nitrogen,ethane and methanol: Experiment and data reduction

Zeck, S. and Knapp, H., 1986. Vapor-liquid and vapor-liquid-liquid phase equilibria for binary and ternary systems of nitrogen, ethane and methanol; experiment and data reduction. Fluid Phase Equilibria, 25: 302–322.VLE and VLLE are investigated for three binary and one ternary system containing N₂, C₂H₆ and CH₃OH in a high-pressure phase equilibrium apparatus with vapor recirculation at temperatures 240 < T < 298 K and pressures 4 < p < 75 bar. Two liquid phases are observed in the systems C₂H₆CH₃OH and N₂CH₃OH. Experimental results are reported and compared with available correlations.     

Isothermal vapor–liquid equilibria of the ternary system formed by ethanol,tert-amyl methyl ether and toluene

Vapor–liquid equilibrium (VLE) data are presented for the ternary system ethanol–tert-amyl methyl ether (TAME)–toluene at 333.15 K. The experimental results were measured by using a Boublik vapor–liquid recirculation still. The results are compared with values predicted from the PRSV equation of state with the modified Huron–Vidal first order (MHV1) and Wong–Sandler (WS) mixing rules. Good agreement is obtained.     

Vapor–liquid equilibria of some binary mixtures formed by methylethylketone at 94.7 kPa

Bubble temperatures at 94.7?kPa, for the binary mixtures formed by methylethylketone (MEK) with cyclo-hexanone, tetrahydrofuran, ortho- and meta-xylenes, bromobenzene, chlorobenzene, epichlorohydrin, nitrobenzene, and iso- and tert-butanols have been measured by means of a Swietoslawski-type ebulliometer. The data could be represented well by the Wilson model.     

Vapor–liquid equilibrium of octane-enhancing additives in gasolines: 6. Total pressure data and GE for binary and ternary mixtures containing 1,1-dimethylethyl methyl ether (MTBE), methanol and n-hexane at 313.15 K

Experimental isothermal P–x data at T=313.15 K for the binary systems 1,1-dimethylethyl methyl ether (MTBE)+n-hexane and methanol+n-hexane, and the ternary system MTBE+methanol+n-hexane are reported. Data reduction by Barker’s method provides correlations for G^E using the Margules equation for the binary systems and the Wohl expansion for the ternary system. Wilson, NRTL and UNIQUAC models have been applied successfully to both the binary and the ternary systems. Moreover, we compare the experimental results for these binary mixtures to the prediction of the UNIFAC (Dortmund) model. Experimental results have been compared to predictions for the ternary system obtained from the Wilson, NRTL, UNIQUAC and UNIFAC models; for the ternary system, the UNIFAC predictions seem poor. The presence of azeotropes in the binary systems has been studied.     

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.     

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.     

Phase equilibria of binary mixtures containing methyl acetate,water, methanol or ethanol at 101.3 kPa

Isobaric vapor–liquid equilibria data at 101.3?kPa were reported for the binary mixtures (methyl acetate?+?(water or methanol or ethanol), methanol?+?(water or ethanol) and (ethanol?+?water)). The experimental data were tested for thermodynamic consistency by means of the Wisniak method and were demonstrated to be consistent. The experimental data were correlated using Wilson, NRTL and UNIQUAC models for the activity coefficients and predicted using the UNIFAC and PSRK equation of state for testing theirs capability. The results show that the obtained data for the studied binary systems are more reliable than other published data.     

Experimental determination and prediction of (solid + liquid) phase equilibria for binary mixtures of aromatic and fatty acids methyl esters

Solid–liquid equilibria for binary mixtures of {methyl stearate (1) + biphenyl (2)}, {methyl stearate (1) + naphthalene (2)}, {methyl palmitate (1) + biphenyl (2)} and {methyl palmitate (1) + naphthalene (2)} were measured using differential scanning calorimeter. Simple eutectic behaviours for these systems were observed. The experimental results were correlated by means of the NRTL, Wilson, UNIQUAC and ideal models. The root-mean-square deviations of the solubility temperatures for all measured data vary from 0.5477 K (for UNIQUAC model) to 7.79 K; the deviations depend on the binary system studied and particular model used. The best solubility correlation was obtained with UNIQUAC model and this observation confirms previous results.     

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     

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.     

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.     

Prediction of vapor–liquid equilibria properties of several HFC binary refrigerant mixtures

New correlations have been developed to estimate saturated vapor pressures of eight HFC binary refrigerant mixtures, namely HFC125/134a, HFC125/143a, HFC134a/236fa, HFC134a/245fa, HFC143a/134a, HFC143a/152a, HFC32/125, and HFC32/134a. In this prediction method, the saturated vapor pressures of mixtures can be calculated by the thermoproperties of pure components, without any adjustable parameters determined by experimental data. The overall average absolute deviation of pressures is <1% compared with experimental data.     

Experimental determination and prediction of (solid + liquid) phase equilibria for binary mixtures of heavy alkanes and fatty acids methyl esters

Solid–liquid equilibria for three binary mixtures of {n-eicosane (1) + methyl palmitate (2)}, {n-tetracosane (1) + methyl stearate (2)} and {n-octacosane (1) + methyl stearate (2)} were measured using differential scanning calorimeter. Simple eutectic behaviours for these systems were observed. The experimental results were correlated by means of the modified UNIFAC (Larsen and Gmehling versions), UNIQUAC and ideal models. The root-mean-square deviations of the solubility temperatures for all measured data vary from 0.21 K (for UNIQUAC model) to 1.07 K (for Ideal model) and depend on the particular model used. The best solubility correlation was obtained with UNIQUAC model.     

Critical properties of the vapor—liquid equilibria of the binary system acetone—n-pentane

Hajjar, R.F., Cherry, R.H. and Kay, W.B., 1986. Critical properties of the vapor—liquid equilibria of the binary system acetone—n-pentane. Fluid Phase Equilibria, 25: 137–146.The P—V—T—x properties for the acetone—n-pentane azeotrope-forming system have been measured by the technique developed by Kay. The experimental uncertainties have been estimated at 0.05 K, 2.4 kPa and 0.06% of the volume. The results for eight different compositions covering the range 180 to 200°C and 2.5 to 4.0 MPa are given. Smoothed critical loci have been plotted. The critical temperatures and pressures were correlated by a quadratic relationship of the form Q_cm = Σ_iΣ_jx_ix_jQ_cij where i, j = 1, 2. The maximum discrepancy in the critical temperature was 0.6 K and in the critical pressure was 0.012 MPa.     

Ebulliometric determination and prediction of (vapor + liquid) equilibria for binary and ternary mixtures containing alcohols (C1–C4) and dimethyl carbonate

(Vapor + liquid) equilibrium (VLE) data for a ternary mixture, namely {methanol + propan-1-ol + dimethyl carbonate (DMC)}, and four binary mixtures, namely an {alcohol (C₃ or C₄) + DMC}, containing the binary constituent mixtures of the ternary mixture, were measured at p = (40.00 to 93.32) kPa using a modified Swietoslawski-type ebulliometer. The experimental data for the binary systems were correlated using the Wilson model. The Wilson model was also applied to the ternary system to predict the VLE behavior using parameters from the binary mixtures. The modified UNIFAC (Dortmund) model was also tested for the predictions of the VLE behavior of the binary and ternary mixtures. In addition, the experimental VLE data for the ternary and constituent binary mixtures were correlated using the extended Redlich–Kister (ERK) model, which can completely represent the azeotropic points. For the ternary system, a comparison of the experimental and the predicted or correlated boiling points obtained using the Wilson and ERK models showed that the ERK model is more accurate. The valley line, i.e., the curve which divides the patterns of vapor–liquid tie lines, was found in the (methanol + propan-1-ol + DMC) system. This valley line could be represented by the ERK model. Finally, the composition profile for simple distillation of this ternary mixture was obtained by analysis of the residue curves from the estimated Wilson parameters of the constituent binary mixtures.     

Measurement and prediction of liquid—liquid equilibria of ethyl acetate—methanol—water in the presence of dissolved inorganic salts

The effect of sodium chloride, calcium chloride and zinc chloride at concentrations 5–20% by weight on the liquid—liquid equilibrium (LLE) data of the ternary system ethyl acetate(S)—methanol(C)—water(A) has been investigated experimentally at 30 °C. The region of heterogeneity is significantly increased with the addition of sodium and calcium chloride salts. A change in the direction of tie-line was observed for 10% sodium chloride, 20% calcium chloride and saturated zinc chloride exhibiting thereby a tendency to form solutropism for this system, which is non-solutropic under a no-salt condition. The selectivity values are also altered in comparison with that of a no-salt condition. The tie-line data have been correlated by the Eisen—Joffe equation. The solubility envelopes for the salt systems have been predicted using the NRTL model, from a knowledge of the binary vapor—liquid equilibria (VLE) determined experimentally in our laboratory employing the iso-activity criterion.     

Solid–liquid equilibria for binary and ternary systems with the Cubic-Plus-Association (CPA) equation of state

A systematic investigation of the CPA model’s performance within solid–liquid equilibria (SLE) in binary mixtures (methane + ethane, methane + heptane, methane + benzene, methane + CO₂, ethane + heptane, ethane + CO₂, 1-propanol + 1,4-dioxane, ethanol + water, 2-propanol + water) is presented. The results from the binary mixtures are used to predict SLE behaviour in ternary mixtures (methane + ethane + heptane, methane + ethane + CO₂). Our results are compared with experimental data found in the literature.