Ternary Vapor–liquid Equilibrium Data Research Articles

Prediction of azeotropes position of refrigerant mixtures using the PHSC EoS

The work aims is predict the azeotropes' position in refrigerant mixtures using the Perturbed Hard Sphere Chain (PHSC) equation of state (EoS). The vapor-liquid equilibrium (VLE) of seventeen binary refrigerant mixtures has been correlated using two model-adjustable parameters. The results show that the proposed model can calculate the bubble and dew points of binary systems, accurately. The average ARD value of binary VLE calculations has been obtained 1.28 %. The azeotropes pressure and composition of binary mixtures have been predicted using the PHSC EoS with the average ARD values of 1.043 % and 2.23 %, respectively. The maximum relative deviation has been observed for R717+R125 systems with two azeotropes points; ARDx=12.2 %. The performance of the PHSC EoS has been evaluated by predicting the azeotropes position of ternary mixtures. The PHSC EoS results have been compared to three cubic-based EoSs containing the PR-vdW, PR-BM, and PR-MHV2-NRTL models. The results show that the PHSC EoS can predict the ternary VLE data and azeotropes position satisfactory. The relative absolute deviation does not exceed 1.7 % for the azeotropes pressure. The PHSC EoS can be used as a robust and efficient model for the prediction of the azeotropes' position in binary and ternary refrigerant mixtures. Prediction of azeotropic composition helps us to find promising refrigerant candidates in the pre-design stage of the desired apparatus.

VLE measurement of binary systems 1-butyl-3-methylimidazolium-based ionic liquids and ethanol or water

Experimental vapor–liquid equilibrium (VLE) data for binary systems of ethanol or water with four ionic liquids (ILs) comprising 1-butyl-3-methylimidazolium cation and different anions were measured at atmospheric pressure within a broad region of IL concentrations, IL mole fraction ranging between 0 and 0.7 or even 0.87. Siwoloboff procedure of vapor–liquid phase transition temperature measurement was applied to estimate VLE of the binary mixtures. Obtained t–x data were fitted assuming ideal vapor and non-ideal liquid phase behavior, using the original NRTL equation to calculate component activity coefficients. VLE description results are presented in form of equilibrium diagrams and as the variation of activity coefficients with mixture composition. Quality of the VLE data fitting was assessed based on root mean square deviations and mean deviations in temperature. Some experimental binary t–x data sets were compared to those available in literature (measured in much narrower concentration range) or predicted from ternary VLE data. The selection of ILs in this study was related to the separation of ethanol−water mixture by extractive distillation. Principal IL selection criterium was its ability to affect the ethanol–water relative volatility. Thermodynamic description of the VLE data of IL-containing systems within a wide concentration range is an essential building block of the mathematical model of separation devices, especially in case of regeneration equipment where concentrated IL is present.

Experimental isobaric vapour-liquid equilibrium data for binary systems of {sec-butyl acetate (SBAC) + acetamide} and {sec-butyl alcohol (SBA) + acetamide} and the ternary system of (SBAC + SBA + acetamide) at 101.3 kPa

Isobaric vapour - liquid equilibrium (VLE) data for the binary systems of sec-butyl acetate (SBAC) + acetamide and sec-butyl alcohol (SBA) + acetamide and the ternary system of SBAC + SBA + acetamide were measured at 101.3 kPa using a modified Othmer still. The thermodynamic consistency tests for the experimental data were checked by Van Ness point test and Wisniak’s L-W method. The experimental VLE data of the binary systems were correlated with NRTL, Wilson and UNIQUAC activity coefficient models. The results indicate that the binary and ternary VLE data predicted by the three models agree well with the experimental data. And the ‘pseudo-azeotropic’ phenomenon of sec-butyl acetate + sec-butyl alcohol mixture can be eliminated by acetamide.

Separation of azeotropic mixture isopropyl alcohol + ethyl acetate by extractive distillation: Vapor-liquid equilibrium measurements and interaction exploration

Isopropyl alcohol and ethyl acetate can be used to produce degradable and renewable fuel. Since isopropyl alcohol + ethyl acetate can form an azeotropic mixture, it is a tough task to separate the binary mixture by general distillation. In this work, extractive distillation process with N, N-dimethylformamide and dimethyl sulfoxide as entrainers was adopted to separate this azeotrope. The binary and ternary vapor-liquid equilibrium data for (isopropyl alcohol + N, N-dimethylformamide), (ethyl acetate + dimethyl sulfoxide), (isopropyl alcohol + ethyl acetate + N, N-dimethylformamide) and (isopropyl alcohol + ethyl acetate + dimethyl sulfoxide) were determined under 101.3 kPa. Meanwhile, the interaction energies between the molecules were calculated to provide the theoretical insight into the separation of the azeotrope of (EA + IPA) by the entrainers. In addition, the NRTL, UNIQUAC and Wilson models were used to fit the determined binary VLE data. The ternary VLE data for (isopropyl alcohol + ethyl acetate + N, N-dimethylformamide) and (isopropyl alcohol + ethyl acetate + dimethyl sulfoxide) were predicted using the NRTL, UNIQUAC and Wilson models with the parameters regressed from the experimental data.

Isobaric Vapor–Liquid Equilibrium for Binary and Ternary Systems of 2-Methoxyethanol, Ethylbenzene, and Dimethyl Sulfoxide at 100.00 kPa

The isobaric vapor–liquid equilibrium (VLE) data for the binary systems 2-methoxyethanol + ethylbenzene, ethylbenzene + dimethyl sulfoxide (DMSO), and 2-methoxyethanol + DMSO and the ternary system 2-methoxyethanol + ethylbenzene + DMSO were measured with a Fischer VLE 602 apparatus at 100.00 kPa. The VLE data for all the binary and ternary systems were thermodynamically consistent and passed the Wisniak’s L–W test. The binary VLE data were correlated with the Wilson, nonrandom two-liquid, and universal quasichemical models with minor deviations. The ternary VLE data predicted from the corresponding binary interaction parameters agreed well with the experimental data. The azeotropic temperature and composition of the 2-methoxyethanol and ethylbenzene azeotropic mixture at 100.00 kPa were 391.05 K and 60.15 mol % 2-methoxyethanol, respectively. Additionally, the azeotrope disappeared after adding DMSO, which confirms that DMSO can serve as a prospective entrainer for separating 2-methoxyethanol from ethylb...

Separation of acetonitrile and methanol azeotropic mixture using imidazolium-based ionic liquids as entrainers

In this work, three imidazolium-based ionic liquids (ILs) with different anions, namely 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]), 1-butyl-3-methylimidazolium bromide ([BMIM][Br]) and 1-butyl-3-methylimidazolium acetate ([BMIM][OAc]), were tested as entrainers to separate acetonitrile and methanol mixtures. Isobaric vapor-liquid equilibrium (VLE) data of the acetonitrile (1) + methanol (2) + IL ternary systems were measured at 101.3 kPa. Addition of ILs produced a salting-out effect on acetonitrile, thus leading to the increase of the relative volatility of acetonitrile to methanol. As IL content increased to a certain value, the azeotropic point of acetonitrile and methanol could be totally eliminated. In addition, the separation performance of ILs was closely related to anion structure, with [BMIM][OAc] producing the most significant salting-out effect orderly followed by [BMIM][Cl] and [BMIM][ Br]. Finally, the measured ternary VLE data were correlated with the nonrandom two-liquid (NRTL) model, and σ-Profiles were used to explain the separation performance differences of the three ILs.

Measurement and correlation of vapor–liquid equilibrium data for binary and ternary systems composed of (−)-β-caryophyllene, p-cymene and 3-carene at 101.33 kPa

Abstract New experimental vapor–liquid equilibrium (VLE) data for three binary systems composed of p-cymene + (−)-β-caryophyllene, 3-carene + (−)-β-caryophyllene, and 3-carene + p-cymene and for the ternary system of (−)-β-caryophyllene + p-cymene + 3-carene were obtained using a modified Ellis equilibrium still over the temperature range from 444.44 to 528.78 K at 101.33 kPa. The compositions of these mixtures were assessed using gas chromatography. The VLE data for the binary systems passed thermodynamic consistency tests based on the Herington method and Van Ness test. The thermodynamic consistency of the ternary system was checked by a Van Ness test. The VLE data for binary systems were correlated using the Wilson, NRTL, and UNIQUAC activity coefficient models with minor deviations. The ternary VLE data were also satisfactorily correlated using the Wilson, NRTL and UNIQUAC models. By comparing the experimental values for the ternary system with the values calculated using the three models, the average absolute deviation of the equilibrium temperature and vapor–phase composition were determined to be less than 0.57 K and 0.0060, respectively. These results indicated excellent agreement of the models with experimental values.

Ternary Vapor–Liquid Equilibrium Measurements and Modeling of Ethylene Glycol (1) + Water (2) + Methane (3) Systems at 6 and 12.5 MPa

Novel technologies in the field of subsea gas processing include the development of natural gas dehydration facilities, which may operate at high pressure due to their proximity to reservoirs. For the qualification and design of these processing units, ternary vapor–liquid equilibrium data are required to validate the thermodynamic models used in the design process. For this purpose, 16 new ternary data points were measured for ethylene glycol (1) + water (2) + methane (3) at 6.0 and 12.5 MPa with temperatures ranging from 288 to 323 K and glycol content above 90 wt %. Glycol in gas (y1), water in gas (y2), and methane solubility (x3) were measured with relative experimental uncertainties (ur(x) = u(x)/|x|) below 12%, depending on the type of data. The Cubic-Plus-Association (CPA) equation of state was used to model the data. Literature pure component and binary interaction parameters were used. It was found that the model provides a good qualitative description of the experimental data for y1 and y2, whi...

Experimental and Predicted Vapor–Liquid Equilibrium for Diisopropanolamine with m-Cresol and 2,6-Dimethylphenol at 20.0 kPa

Measurements of isobaric vapor–liquid equilibrium (VLE) results for binary systems of m-cresol (MC) + diisopropanolamine (DIPA) and 2,6-dimethylphenol (DMP) + DIPA and the ternary system of MC + DMP + DIPA were conducted at the pressure of 20.0 kPa. The binary VLE experimental data showed that DIPA had stronger interaction with MC than DMP. The ternary system experimental VLE data showed that DIPA could improve the relative volatility of DMP to MC. The binary experimental data were checked by using Herington area and point test methods, and the checked results were thermodynamically consistent. Meanwhile, the VLE data were correlated by Wilson, nonrandom two-liquid, and universal quasichemical models, and the binary energy interaction parameters for these models were obtained. These activity coefficient models were used to predict the ternary system VLE data. The predictive results suggested that the Wilson model had the best prediction.

Isobaric Vapor–Liquid Equilibrium for 2-Butanone + Ethanol System Containing Different Ionic Liquids at 101.3 kPa

In this work, ionic liquids (ILs) were selected as extractive distillation entrainers to separate the 2-butanone + ethanol binary azeotropic mixture because of their remarkable molecular designability, high selectivity, low volatility, and other excellent characteristics. The isobaric vapor–liquid equilibrium (VLE) data for the ternary systems of 2-butanone + ethanol + acetate-based ILs (1-ethyl-3-methylimidazolium acetate [EMIM][OAC], 1-butyl-3-methylimidazolium acetate [BMIM][OAC], and 1-hexyl-3-methylimidazolium acetate [HMIM][OAC]) were measured at 101.3 kPa in an all-glass dynamic recirculating still. The addition of ILs can significantly enhance relative volatility of 2-butanone to ethanol, and the azeotropy of the 2-butanone + ethanol binary mixture is eventually eliminated by increasing the IL content to a certain value. The separation efficiency of the three ILs follows the order [EMIM][OAC] > [BMIM][OAC] > [HMIM][OAC]. Additionally, the binary and ternary VLE data are well-correlated with the no...

Isobaric vapor–liquid equilibrium for ternary system of ethanol, ethyl propionate and para-xylene at 101.3 kPa

Isobaric vapor–liquid equilibrium (VLE) data for the binary system ethyl propionate (2) + para-xylene (3) and ternary system ethanol (1) + ethyl propionate (2) + para-xylene (2) at atmospheric pressure (101.3 kPa) were obtained by a VLE modified othmer still. All the experimental data passed a point to point consistency test of Van Ness method, which verified the data reliability. The Wilson and UNIQUAC activity coefficient models were employed to correlate the binary VLE data to obtain binary interaction parameters. Based on binary interaction parameters, ternary VLE data of ethanol (1) + ethyl propionate (2) + para-xylene (3) were predicted by Wilson and UNIQUAC models, which proved that predicted values are consistent with the experimental data. Furthermore, azeotropic phenomenon between ethanol and ethyl propionate disappears when the mole ratio of para-xylene and binary system of ethanol and ethyl propionate is 1:1. Therefore, this paper convinced that para-xylene is a proper extractive additive that could be used in extractive distillation to separate the binary azeotropic system of ethanol and ethyl propionate.

Vapor–liquid equilibrium in the ternary system isobutyl alcohol + isobutyl acetate + N, N-dimethyl acetamide and the binary systems isobutyl alcohol + N, N-dimethyl acetamide, isobutyl acetate + N, N-dimethyl acetamide at 101.3 kPa

The isobaric Vapor-Liquid Equilibrium (VLE) data at 101.3 kPa were measured for the binary systems isobutyl alcohol + N, N-dimethyl acetamide (DMAC), isobutyl acetate + N, N-dimethyl acetamide and the ternary system isobutyl alcohol + isobutyl acetate + N, N-dimethyl acetamide using an all glass dynamics recirculating still. The isobutyl alcohol + DMAC system exhibits negative deviation from Raoult's law and isobutyl acetate + DMAC system deviates positively from ideal solution. The thermodynamic consistency of the binary VLE data was checked by Herington method and Wisniak point-to-point method. The NRTL, UNIQUAC and Wilson activity coefficient models were used to correlate the binary VLE data in order to obtain the binary interaction parameters which were used to predict ternary VLE data. The predicted results agree well with the experimental data. The results indicate that the solvent DMAC can greatly enhance the relative volatility of isobutyl acetate to isobutyl alcohol, and azeotrope of isobutyl acetate and isobutyl alcohol will be broken if the mole fraction of DMAC is greater than 0.361. The effects of the solvents 1-hexanol, butyl propionate (BUP), N, N-dimethyl formamide (DMF) and N, N-dimethyl acetamide (DMAC) were compared, and the selectivity of DMAC was the largest. The solvent DMAC is a promising extractive agent for the separation of mixtures of isobutyl alcohol and isobutyl acetate by extractive distillation.

Isobaric Vapor–Liquid Equilibrium for the Binary and Ternary System with Isobutyl Alcohol, Isobutyl Acetate and Dimethyl Sulfoxide at 101.3 kPa

The isobaric vapor–liquid equilibrium (VLE) data for the binary systems isobutyl alcohol + dimethyl sulfoxide (DMSO), isobutyl acetate + DMSO, and ternary system isobutyl alcohol + isobutyl acetate + DMSO were measured at 101.3 kPa. All of the binary VLE data passed Wisniak’s modifed Herington area test and Wisniak point and area test. Ternary VLE data passed Wisniak point test. The VLE data of binary systems were correlated with NRTL, UNIQUAC, and Wilson models. The ternary VLE behavior were successfully predicted by the correlated binary parameters. The VLE data for the binary and ternary systems predicted by the correlated interaction parameters were in good agreement with all the experimental data. The relative volatility of isobutyl acetate to isobutyl alcohol can be greatly increased by DMSO and the azeotropic point of isobutyl acetate and isobutyl alcohol will disappear if the mole fraction of DMSO is greater than 0.36. DMSO is a promising solvent for separating the azeotrope of isobutyl alcohol an...

Isothermal vapor liquid equilibrium measurements for difluoromethane (R32) + fluoroethane (R161) + trans-1,3,3,3-tetrafluoropropene (R1234ze(E)) ternary mixtures

Difluoromethane (R32) + fluoroethane (R161) + trans-1,3,3,3-tetrafluoropropene (R1234ze(E)) ternary system could be a promising alternative refrigerant mixture. The vapor liquid equilibrium (VLE) data for this system are important for the evaluation of its performance. In this work, the VLE of R32 + R161 + R1234ze(E) were measured for the first time by a quasi-static analytical apparatus over the temperature range of 283.15 to 323.15 K. The ternary system of R32 + R161 + R1234ze(E) is a zeotropic system within the studied temperature range. The Peng–Robinson–Stryjek–Vera (PRSV) equation of state combined with the Wong–Sandler (WS) mixing rule and the non-random two-liquid (NRTL) activity coefficient model was used to predict the ternary VLE data by using the parameters of binary mixtures (R32 + R161, R32 + R1234ze(E) and R161 + R1234ze(E)). The calculated values show excellent agreement with the experimental results. The average absolute deviation (AAD) of pressure is 0.16%. The average absolute deviations of vapor phase mole fractions for R32 and R161 are 0.0021 and 0.0028, respectively.

Isobaric Vapor–Liquid Equilibrium for Binary and Ternary Systems of Isoamyl Alcohol + Isoamyl Acetate + Dimethyl Sulfoxide at 101.33 kPa

Isobaric vapor–liquid equilibrium (VLE) data for binary systems of isoamyl alcohol + dimethyl sulfoxide (DMSO) and isoamyl acetate + DMSO, and the ternary system of isoamyl alcohol+ isoamyl acetate + DMSO at 101.33 kPa were measured by a modified Rose-Williams equilibrium still. The binary experimental data were checked by Herington method and a Van Ness test to verified thermodynamic consistency. The ternary VLE data was checked by Van Ness test. The experimental measurements of the binary systems were correlated by Wilson, nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) activity coefficient models with minor deviation. The ternary VLE data predicted by the obtained correlation parameters fit well with the experimental data. The experimental results indicate that the relative volatility between isoamyl alcohol and isoamyl acetate is changed obviously with the addition of DMSO as an entrainer at 0.50 mass fraction, which shows DMSO is an effective solvent for the separation of isoamyl al...

Modeling of gaseous hydrocarbons solubility in aqueous-amine systems by VTPR model

It is crucial to know the solubility of gaseous and liquid hydrocarbons in aqueous alkanolamine solutions in order to quantify accurately the hydrocarbon losses in treating processes. Hence, consistent experimental data and accurate models are essential for the efficient design and optimization of these processes. In this work, a homogeneous approach based on the modified Volume Translation Peng-Robinson (VTPR) cubic equation of state was adopted to represent the solubility of methane, ethane and propane in aqueous mono-ethanol-amine, di-ethanol-amine and methyl-di-ethanol-amine which are the most common solvents used in the effluent treatment processes. The model parameters were estimated on the basis of binary and ternary vapor-liquid and liquid-liquid equilibrium data. The model developed shows a satisfactory representation of the experimental data with average deviations ranging from 1 to 28% for all systems, and gives a solid foundation for predicting hydrocarbon solubility in aqueous alkanolamine solutions.

Vapor–Liquid Equilibria for Ternary Mixtures of Isopropyl Alcohol, Isopropyl Acetate, and DMSO at 101.3 kPa

The vapor–liquid equilibrium (VLE) data for the binary system isopropyl alcohol + dimethyl sulfoxide (DMSO), isopropyl acetate + DMSO, and ternary system isopropyl alcohol + isopropyl acetate + DMSO were measured with a VLE modified Othmer still at 101.3 kPa. The experimental data were proved to be thermodynamically consistent when the point-to-point consistency test of Van Ness test was applied. The binary experimental data were correlated with the nonrandom two-liquid (NRTL), Wilson, and universal quasichemical (UNIQUAC) activity coefficient models. Then, the ternary VLE data were predicted with the obtained binary interaction parameters. The results indicate that the values of equilibrium temperature and vapor mole fraction calculated by the NRTL, Wilson, and UNIQUAC models are in good agreement with the experimental data. When the mole ratio of the binary azeotrope to DMSO was 1:1.5, the binary azeotrope of isopropyl alcohol and isopropyl acetate was eliminated. Therefore, DMSO is a potential extracti...

Experimental Measurement and Modeling of Vapor–Liquid Equilibrium for the Ternary System Water + 1-Propanol + Glycerol

Vapor–liquid equilibrium (VLE) data were reported for the ternary system water + 1-propanol + glycerol at 100 kPa. The NRTL equation was used for the modeling of ternary VLE. Binary parameters of water + glycerol were fixed as the same for water + ethanol + glycerol and were taken from the literature. The ternary VLE data, together with literature results of binary VLE data and infinite dilution activity coefficients for water +1-propanol, were used for the modeling. To extend the glycerol composition range and the temperature range, infinite dilution activity coefficients of 1-propanol in glycerol were measured in a temperature range of 313.15 to 393.15 K, and were used in the modeling. The correlation provided good agreement for all the source data. It is shown that the infinite dilution activity coefficients provide key information for reliable correlation in a wide composition range. With the addition of glycerol, the azeotrope of water + 1-propanol can be removed at a glycerol mole fraction of 0.398,...

Isobaric ternary vapour–liquid equilibrium of methanol(1) + diisopropyl ether(2) + isopropyl alcohol(3) along with methanol + isopropyl alcohol binary data at atmospheric and sub-atmospheric pressures

Experimental vapour–liquid equilibrium (VLE) data of the ternary system methanol(1)+diisopropyl ether(2)+isopropyl alcohol(3) at 53.33, 66.66, 79.99 and 95.33kPa, studied using a Sweitoslawski-type ebulliometer over the entire composition range is reported here. VLE data of one of the constituent binaries of this ternary system, methanol(1)+isopropyl alcohol(3) was also measured at 53.33, 66.66, 79.99 and 94.79kPa. Wilson, NRTL, UNIQUAC, Peng–Robinson (PR) and Soave–Redlich–Kwong (SRK) equations of state (EoS) combined with Wong–Sandler (WS) mixing rules were used to correlate the experimental binary data. The experimental binary data has also been compared with predictions from UNIFAC model. NRTL model was found to represent the methanol(1)+isopropyl alcohol(3) system best. Experimental ternary VLE data was found to be in good agreement with predictions from NRTL model with an average root mean square deviation of 0.1164 between experimental and predicted temperatures.

Experimental isobaric vapor liquid equilibrium for the ternary system of sec-butyl alcohol + sec-butyl acetate + dimethyl sulfoxide at 101.3 kPa

Isobaric vapor–liquid equilibrium (VLE) data were measured for the binary systems sec-butyl alcohol+dimethyl sulfoxide (DMSO), sec-butyl acetate+DMSO and the ternary system sec-butyl alcohol+sec-butyl acetate+DMSO at 101.3kPa using a vapor–liquid equilibrium still. The thermodynamic consistency test for the binary experimental data was made by Herington method, Wisniak's L–W method and a point to point method of Van Ness test described by Fredenslund et al. And the thermodynamic consistency of the ternary system was checked by Van Ness test. The VLE data for the binary systems were correlated with the NRTL, Wilson and UNIQUAC activity coefficient models. And the binary and ternary VLE data predicted by the obtained binary interaction parameters agree well with the experimental data. The experimental results show that the relative volatility between sec-butyl alcohol and sec-butyl acetate is changed obviously when the mass ratio of DMSO to the pseudo-azeotrope mixture is 6:5. And DMSO is a promising extractive agent for the separation of the mixture of sec-butyl alcohol and sec-butyl acetate in extractive distillation.