Isothermal Vapor-liquid Equilibrium Data Research Articles

정온하에서 Ethanol/3-methyl-1-butanol계의 기-액평형치 추산

Recently, an understanding of new sources of liquid hydrocarbons such as bio-ethanol is economically very important. Successful design of distillation columns in a separation process depend on the availability of accurate vapor-liquid equilibrium data. For the binary system of Ethanol/3-methyl-l-butanol mixture, isothermal Vapor-liquid equilibrium data were measured at temperature of 50, 55, 60, 65, 70, 75 and . An empirical relation to predict Vapor-liquid equilibrium data was obtained from the above measured data. The predicted values are compared with the measured ones to be in a good agreement within accuracy of , .

Isothermal Vapor–Liquid Equilibrium Data and Modeling for the Ethane (R170) + Perfluoropropane (R218) System at Temperatures from (264 to 308) K

Isothermal vapor–liquid equilibrium data are presented for the ethane (R170) + perfluoropropane (R218) binary system. Measurements were performed at five isotherms ranging from (264.05 to 308.04) K, with pressure ranging from (0.298 to 4.600) MPa. The measurements were undertaken using a “static-analytic” type apparatus, with sampling of the equilibrium phases via a mobile capillary sampler (ROLSI). The uncertainties in the measurements were within 0.06 K, 0.9 kPa, and less than 0.006 for temperature, pressure, and mole fraction, respectively. The full set of isothermal vapor–liquid equilibrium data was successfully correlated with the Peng–Robinson equation of state, incorporating the Mathias–Copeman alpha function, and the Wong–Sandler mixing rule with the Non-Random Two-Liquid (NRTL) activity coefficient model.

Vapor–Liquid Equilibrium at 350 K, Excess Molar Enthalpies at 298 K, and Excess Molar Volumes at 298 K of Binary Mixtures Containing Ethyl Acetate, Butyl Acetate, and 2-Butanol

Vapor–liquid equilibrium (VLE), excess molar enthalpies (HE), and excess molar volumes (VE) provide means of developing accurate thermodynamic models. In this work, new data of binary mixtures of ethyl acetate, butyl acetate, and 2-butanol are reported. Isothermal VLE data at 350 K were measured by using a circulation still for ethyl acetate + 2-butanol, for 2-butanol + butyl acetate, and for ethyl acetate + butyl acetate. HE was measured at 298 K by using a SETARAM C80 calorimeter equipped with a flow mixing cell. VE was measured at 298 K by using an Anton Paar DMA 512P densimeter. Liquid phase activity coefficients of the Wilson model and vapor phase fugacities of the Hayden–O’Connell correlation were regressed for a thermodynamic model based on the measured data. Model extrapolation agreed well with literature data. Redlich–Kister equation parameters were regressed by using only the measured VE data.

Vapor–Liquid Equilibrium, Excess Molar Enthalpies, and Excess Molar Volumes of Binary Mixtures Containing 2-Ethoxy-2-methylpropane or 2-Ethoxy-2-methylbutane and Acetonitrile or Propanenitrile

Vapor–liquid equilibrium (VLE), excess molar enthalpies (HE), and excess molar volumes (VE) provide complementary data for thermodynamic models. In this work, new data of binary mixtures of acetonitrile (ACN) or propanenitrile (PPN) with 2-ethoxy-2-methylpropane (ETBE) or 2-ethoxy-2-methylbutane (TAEE) are reported. Isothermal VLE data were measured by using a circulation still at 333 K for ETBE + ACN, at 343 K for TAEE + ACN, and at 363 K for TAEE + PPN. HE were measured by using a SETARAM C80 calorimeter equipped with a flow mixing cell at 298 K for all four binary systems. VE were measured by using an Anton Paar DMA 512P densimeter at 298 K for all four binary systems. HE data and measured VLE data, or literature VLE data for the binary system of ETBE and PPN, were used for the optimization of Wilson model parameters by using VLEFIT software. Redlich–Kister equation parameters were separately regressed for the VE data.

Isothermal vapor–liquid equilibrium of R170 + n-perfluorooctane at 308–338 K: Measurement, equation of state modelling, and molecular simulation

Isothermal vapor–liquid equilibrium data are presented for the R170+n-perfluorooctane system. Measurements were performed at five isotherms ranging from 308.45 to 338.43K and were undertaken using a “static-analytic” type apparatus, with sampling of the equilibrium phases via a moveable capillary sampler (ROLSI™). The uncertainties in the measurements of temperature, pressure, and phase compositions were within 0.036K, 0.0058MPa, and less than 0.02molmol−1 respectively. The VLE data were correlated with the Peng–Robinson equation of state, incorporating the Mathias–Copeman α function. The Wong–Sandler mixing rule with the non-random two-liquid (NRTL) activity coefficient model and the classical one-fluid mixing rule were used. The Wong–Sandler mixing rule represents the experimental data more accurately than the classical mixing rule. These measurements have also been compared to results obtained from isobaric–isothermal Gibbs ensemble Monte Carlo molecular simulations. Very good agreement between experiment and simulation was obtained, although systematic under-estimation of the experimental vapor compositions was observed. The simulations further validate the transferability of an existing optimum Lennard–Jones cross-parameter set. Radial distribution functions for the liquid phase were calculated and show that R170 molecules tend to cluster around each other, while the CF2 groups on n-perfluorooctane molecules show the least preference for mutual proximity.

Vapor-liquid equilibrium data concerning refrigerant systems (R3110+R365mfc)

In ORC, the knowledge of phase diagram of working fluid is essential. In this paper isothermal vapor liquid equilibrium data are presented for the R3310 + R365mfc system. Measurement were performed for seven isotherms (three below and four above the critical temperature of C4F10) ranging from 333.26 to 441.61 K, with pressure ranging from 0.2016 to 3.0927 MPa. The measurements were undertaken using a “static-analytic” type apparatus, with sampling of the equilibrium phases via capillary samples (ROLSI TM ). The maximum uncertainties in the measurements were within ± 0.02 K, 0.0003 MPa and less than ± 0.004 for temperature, pressure, and equilibrium phase mole fractions, respectively. The full set of isothermal vapor-liquid equilibrium data were correlated with the Peng-Robinson equation of state, incorporating the Mathias-Copeman alpha function, with the Wong-Sandler mixing rule utilizing the NRTL activity coefficient model.

Thermodynamic Study of Mixtures of Compounds Present During the Carbon Dioxide Capture, Transport and Storage

Within the fight against global warming and the reduction of greenhouse-gases emission, research has been particularly intense over the last years to develop efficient processes of carbon dioxide captures. Indeed, along with carbon dioxide and water, a great number of compounds such as O2, N2, Ar, SOx, NOx, H2 and CO can be present at different levels of concentration. The objective of this communication is to provide new sets of data to characterize phase equilibrium of these systems for the development of geological storage technologies. So, Isothermal vapour-liquid equilibrium data are reported for the following systems (SO2-O2-N2 and CO2-O2- H2O). The pressure and temperature ranges for this study are 6-18MPa and 323-373K, respectively. All measurements were carried out using an apparatus based on the “static-analytic” method.

Vapour–liquid equilibrium of binary systems containing pentafluorochemicals from 363 to 413 K: Measurement and modelling with Peng–Robinson and three SAFT-like equations of states

New sets of data are provided to characterize the phase equilibrium of new mixtures containing fluorochemicals and show their potential in energy recovery applications, as industrial heat pumps. Isothermal Vapour–Liquid Equilibrium data have been measured for R245fa + isopentane, and R365mfc + isopentane systems. Measurements were performed for four isotherms with pressure from 0.4 to 2.9 MPa. The data are correlated using different models (Peng–Robinson, PC-SAFT, polar PC-SAFT and SAFT-VR equations of state) and all four approaches can accurately describe the VLE. A very good description of the VLE for the pure components and the mixtures can be obtained by representing the R245fa and R365mfc molecules either as non-polar associating compounds or as non-associating dipolar molecules. To confirm the experimental values of the dipoles used in polar PC-SAFT, we performed DFT calculations of the permanent dipoles of the molecules and a good agreement with the experimental values is found for R245fa, while two different values corresponding to two different conformations were found for R365mfc.

Measurement and correlation of the isothermal vapor-liquid equilibrium data for carbon dioxide and dimethyl ether system

Vapor-liquid equilibrium (VLE) data for the binary system of carbon dioxide (CO2)+dimethyl ether (DME) were measured at six equally spaced (10 K) temperatures between 283.15 and 333.15 K. The data in the two-phase region were measured by using a circulation-type equilibrium apparatus in which both vapor and liquid phases are continuously recirculated. The equilibrium compositions of vapor and liquid phases and pressure were reported at each temperature. The experimental VLE data were correlated with PR-EoS using the Wong-Sandler (W-S) mixing rule and the universal mixing rule (UMR). The overall average values of AAD-P (%) and AAD-y through the temperature range from 283.15 to 333.15 K were 1.0% and 0.012 for the W-S mixing rule and 0.88% and 0.014 for the UMR, respectively. All values are small and acceptable. Calculated results with these equations have given satisfactory results compared with the experimental data.

Measurement of VLE data of carbon dioxide + dimethyl carbonate system for the direct synthesis of dimethyl carbonate using supercritical CO2 and methanol

Isothermal vapor–liquid equilibrium data for the binary system of carbon dioxide+dimethyl carbonate (DMC) were measured at 278.15, 283.15, 293.15, 303.15, 313.15, 323.15 and 333.15K using a circulation-type equilibrium apparatus in which both vapor and liquid phases were recirculated. The equilibrium compositions of vapor and liquid phases and pressures were reported at each temperature. The measured data were correlated with the Peng–Robinson equation of state (PR-EoS) using the Wong–Sandler mixing rules combined with the NRTL excess Gibbs free energy model and the Peng–Robinson equation of state (PR-EoS) using the Universal mixing rule. Calculated results with these equations can be used to estimate the thermodynamic properties of this binary system of CO2 (1)+DMC (2).

Vapor-liquid Equilibrium Data Concerning Refrigerant Systems (R116 + R143a)

Development of modern refrigeration systems is critical for the success of new global environmental protection efforts. The binary system of refrigerants: Hexafluoroethane (R116) + 1,1,1- trifluoroethane (R143a), has been studied with the aim of providing PTxy data. Isothermal vapor-liquid equilibrium data have been generated using the “static-analytic” method from 258 to 328K at pressures from 0.39 to 3.89MPa. The modelcomposed of the Peng-Robinson equation of state, the Mathias-Copeman alpha function, the Wong-Sandler mixing rules and the NRTL cell theory is applied herein to correlate the data and calculate the critical line.

Vapor–liquid equilibrium data for the dimethyl ether (RE170) + decafluorobutane (R3-1-10) system at temperatures from 313.28 to 392.83 K and pressures up to 4.9 MPa

Isothermal vapour–liquid equilibrium data have been measured for the RE170+R3-1-10 binary system at nine temperatures between 313.28 and 392.83K, and pressures between 0.57 and 4.9MPa. The experimental method used in this work is of the static-analytic type, taking advantage of two pneumatic capillary samplers (ROLSI™, Armines’ patent) developed in the CEP/TEP laboratory. The data were obtained with accuracies within ±0.02K, ±0.0006MPa and ±0.009 for molar compositions. The particularity of this system is to present an azeotrope. The isothermal P, x, y data are well represented with the Peng and Robinson equation of state using the Mathias Copeman alpha function and the Wong–Sandler mixing rules involving the NRTL gE model.

Simultaneous Prediction of Densities and Vapor–Liquid Equilibria of Mixtures Containing an Isomeric Chlorobutane and Methyl tert-Butyl Ether Using the VTPR Model

Densities of four binary mixtures formed by an isomer of chlorobutane (1-chlorobutane, 2-chlorobutane, 1-chloro-2-methylpropane, or 2-chloro-2-methylpropane) and methyl tert-butyl ether have been measured in the temperature range 283.15 K–313.15 K; from these densities the corresponding excess volumes have been obtained and correlated. The isothermal vapor–liquid equilibria have been also studied at T = 288.15, 298.15, and 308.15 K, and the experimental data have been satisfactorily checked for thermodynamic consistency using the method of Van Ness. The isothermal vapor–liquid equilibria data have been correlated using the Wilson equation, and excess Gibbs energies have been calculated. We have employed this experimental information to check the reliability of the predicted densities and vapor–liquid equilibria of the volume translated Peng–Robinson group contribution equation of state (VTPR model) by comparing the experimental results with the corresponding predictions. The predictions of both properties...

Phase equilibrium for the binary azeotropic mixture of trifluoroiodomethane (R13I1) + 1,1,2,2-tetrafluoroethane (R134) at temperatures from 258.150 to 283.150 K

Isothermal vapor–liquid equilibrium data of binary trifluoroiodomethane (R13I1) + 1,1,2,2-tetrafluoroethane (R134) systems at 258.150, 263.150, 273.150 and 283.150 K were measured by a recirculation apparatus with visual windows. The measured uncertainties of the temperature, pressure, and compositions are less than ±5 mK, ±0.0005 MPa, and ±0.005, respectively. All the experimental data were correlated by the Peng–Robinson (PR) EoS with the Huron–Vidal (HV) mixing rule utilizing the non-random two-liquid (NRTL) activity coefficient model. Azeotropic behavior can be found at the measured temperature range.

Experimental and Molecular Modeling Study of the Three-Phase Behavior of (n-Decane + Carbon Dioxide + Water) at Reservoir Conditions

Knowledge of the phase behavior of mixtures of oil with carbon dioxide and water is essential for reservoir engineering, especially in the processes of enhanced oil recovery and geological storage of carbon dioxide. However, for a comprehensive understanding, the study of simpler systems needs to be completed. In this work the system (n-decane + carbon dioxide + water) was studied as a model (oil + carbon dioxide + water) mixture. To accomplish our aim, a new analytical apparatus to measure phase equilibria at high pressure was designed with maximum operating temperature and pressure of 423 K and 45 MPa, respectively. The equipment relies on recirculation of two coexisting phases using a two-channel magnetically operated micropump designed during this work, with sampling and online compositional analysis by gas chromatography. The apparatus has been validated by comparison with published isothermal vapor-liquid equilibrium data for the binary system (n-decane + carbon dioxide). New experimental data have been measured for the system (n-decane + carbon dioxide + water) under conditions of three-phase equilibria. Data for the three coexisting phases have been obtained on five isotherms at temperatures from 323 to 413 K and at pressures up to the point at which two of the phases become critical. The experimental work is complemented here with a theoretical effort in which we developed models for these molecules within the framework of the statistical associating fluid theory for potentials of variable range (SAFT-VR). The phase behavior of the three binary subsystems was calculated using this theory, and where applicable, a modification of the Hudson and McCoubrey combining rules was used to treat the systems predictively. The experimental data obtained for the ternary mixture are compared to the predictions of the theory. Furthermore, a detailed analysis of the ternary mixture is carried out based on comparison with available data for the constituent binary subsystems. In this way, we analyzed the observed effects on the solubility when the third component was added.

Isothermal vapor-liquid equilibria for the binary system of dimethyl ether (CH3OCH3)+ methanol (CH3OH)

Isothermal vapor-liquid equilibrium data for the binary mixture of dimethyl ether (CH3OCH3)+methanol (CH3OH) were measured within the temperature range of 308.15–328.15 K. The data in the two-phase region were measured by using a circulation-type equilibrium apparatus in which both vapor and liquid phases are continuously recirculated. The experimental data were correlated with the Peng-Robinson equation of state (PR-EoS) using the Wong-Sandler mixing rules combined with the NRTL excess Gibbs free energy model. The values calculated by the PR-EOS with the W-S mixing rules show good agreement with our experimental data.

Vapor–liquid equilibria at 333.15 K and excess molar volumes and deviations in molar refractivity at 298.15 K for mixtures of diisopropyl ether, ethanol and ionic liquids

In this work, we have studied influence of ionic liquids (ILs) on the azeotrope composition for the system {diisopropyl ether (DIPE) + ethanol} using trihexyltetradecylphosphonium chloride ([P 666,14][Cl]) and trihexyltetradecylphosphonium bis(2,2,4-trimethylpentyl) phosphinate ([P 666,14][TMPP]). Isothermal vapor–liquid equilibrium data at 333.15 K are reported for the ternary systems {DIPE + ethanol + [P 666,14][Cl]} and {DIPE + ethanol + [P 666,14][TMPP]} with varying the mole fraction of ILs from 0.05 to 0.10. The experimental ternary VLE data were correlated using the Wilson equation. In addition, excess molar volumes ( V E) and deviations in molar refractivity (Δ R) data at 298.15 K are reported for the binary systems {DIPE + [P 666,14][Cl]} and {ethanol + [P 666,14][Cl]} by a digital vibrating tube densimeter and a precision digital refractometer. The V E and Δ R were correlated by the Redlich–Kister equation.

Isothermal Vapor–Liquid Equilibrium Data of Propan-1-ol + 2,2,4-Trimethylpentane and Butan-1-ol + 2,2,4-Trimethylpentane at 318.15 K

In this research, vapor–liquid equilibrium (VLE) data were determined at 318.15 K for the mixtures propan-1-ol + 2,2,4-trimethylpentane and butan-1-ol + 2,2,4-trimethylpentane in an isothermic Othmer still with recirculation, where the temperature was kept constant by means of a proportional-integral (PI) cascade control for the vapor phase. The equilibrium concentration for each phase was determined by gas chromatography, and the vapor phase was considered as nonideal. The consistency of the data was verified by means of the Van Ness direct test of thermodynamic consistency, supported by several thermodynamic methods based on the Gibbs–Duhem equation. The correlation of the VLE data was carried out using the Wilson local composition model. The alkanol + 2,2,4-trimethylpentane mixtures studied exhibit positive contributions from ideality and azeotropic behavior.

Isothermal vapour–liquid equilibria and excess enthalpies for the binary mixtures containing an isomeric chlorobutane and diisopropyl ether

Isothermal vapour–liquid equilibria for the four binary mixtures formed by an isomer of chlorobutane (1-chlorobutane, 2-chlorobutane, 2-methyl-1-chloropropane, or 2-methyl-2-chloropropane) and diisopropyl ether has been studied at T = 288.15 K, 298.15 K, and 308.15 K. The experimental data have been satisfactorily checked for thermodynamic consistency using the method of van Ness. The isothermal vapour–liquid equilibrium data have been correlated using the Wilson equation and excess Gibbs energies have been calculated. Moreover, we have measured excess enthalpies at T = 298.15 K using an isothermal flow calorimeter; combining these excess enthalpies with excess Gibbs energies the corresponding entropic contributions to excess Gibbs energy have been obtained. The group contribution method UNIFAC has been used to predict the phase equilibrium behaviour of the mixtures at isothermal conditions.

Vapor-Liquid Equilibrium of Carbon Dioxide + Ethanol: Experimental Measurements with Acoustic Method and Thermodynamic Modeling

Phase behavior of systems composed by supercritical carbon dioxide and ethanol is of great interest, especially in the processes involving supercritical extraction in which ethanol is used as a cosolvent. The development of an apparatus, which is able to perform the measurements of vapor-liquid equilibrium (VLE) at high pressure using a combination of the visual and the acoustic methods, was successful and was proven to be suited for determining the isothermal VLE data of this system. The acoustic method, based on the variation of the amplitude of an ultra-sound signal passing through a mixture during a phase transition, was applied to investigate the phase equilibria of the system carbon dioxide + ethanol at temperatures ranging from 298.2 K to 323.2 K and pressures from 3.0 MPa to 9.0 MPa. The VLE data were correlated with Peng-Robinson equation of state combined with two different mixing rules and the SAFT equations of state as well. The compositions calculated with the models are in good agreement with the experimental data for the isotherms evaluated.