At present,the environment impact of refrigerants has been given attention.The binary mixture R152a/R1234ze(E)is an environmentally friendly refrigerant,which solves problems of poor cooling performance of the R1234ze...At present,the environment impact of refrigerants has been given attention.The binary mixture R152a/R1234ze(E)is an environmentally friendly refrigerant,which solves problems of poor cooling performance of the R1234ze(E)cycle and flammability of R152a.In order to obtain its basic thermal and physical parameters,it is necessary to carry out vapor-liquid equilibrium(VLE)research,and the cubic equation of states(EOS)is often used in the calculation of the thermodynamic properties of mixtures.In this paper,the VLE predicted models for R152a/R1234ze(E)in the temperature range of 298.15-328.15 K were constructed using Soave-Redlich-Kwong(SRK),Peng-Robinson(PR)equations of state(EOS)combined with van der Waals(vd W),Huron-Vidal(HV)mixing rules,respectively.The equilibrium pressures and vapor-phase mole fractions of the models were obtained by calculation,and all four models presented an extreme correlation with the experimental data.And it can be concluded that the calculated results of the PR+HV model are closer to the experimental data than those of the other three models,with the average absolute deviation of 0.0027 for vapor-phase mole fraction(AAD(ycal))and the average absolute relative deviation of 0.243%for equilibrium pressure(AARD(pcal)),which provides a basis for accurately calculating the thermophysical properties of the mixture R152a/R1234ze(E).展开更多
Based on the COSMO-SAC model,1-ethyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium p-toluenesulfonate were selected from 30 ILs as entrainers to investigate the separation of the isopropyl alcohol+isopro...Based on the COSMO-SAC model,1-ethyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium p-toluenesulfonate were selected from 30 ILs as entrainers to investigate the separation of the isopropyl alcohol+isopropyl acetate azeotrope.Two screening indicators,σ-profile and infinite dilution selectivity(S^(∞)),were adopted as the basis.The iso baric vapor-liquid equilibrium experiments for isopropyl alcohol+isopropyl acetate binary system and isopropyl alcohol+isopropyl acetate+confirmed ILs ternary systems were performed at the pressure of atmospheric pressure.The experimental measurement demonstrated that the adopt ILs enhanced the relative volatility of the above alcohol-ester azeotrope,leading to the elimination of the azeotropic point with a certain amount ILs.Meanwhile,the thermodynamic correlation for two systems containing ILs was explored with the NRTL model,which also reflects the extensive applicability of that by comparing the deviation between experimental and calculated data.And its binary interaction parameters were regressed,which can provide a basis for its simulation process.展开更多
Vapor-liquid euilibrium (VLE) for a ternary system of Methyldichlorosilane+methylvinyldichlorosilane+toluene and constituent binary systems were measured at 101.3kPa using a new type of magnetical pump-ebulliometer,Th...Vapor-liquid euilibrium (VLE) for a ternary system of Methyldichlorosilane+methylvinyldichlorosilane+toluene and constituent binary systems were measured at 101.3kPa using a new type of magnetical pump-ebulliometer,The equilibrium conpositions of the vapor phase of binary systems were calculated indirectly from the total pressure-temperature-liquid composition(pTx).The experimental data were correlated with the Wilson and NRTL(non-random two liquid )equations.The parameters of the Wilson moldel were employed to predict the ternary VLE data .The calculated boiling points were in good agreement with the experimental ones.展开更多
The vapor-liquid equilibrium data of four binary systems (acetic acid +p-xylene, methyl acetate +n-propyl acetate, n-propyl acetate +p-xylene and methyl acetate +p-xylene) are measured at 101.33 kPa with Ellis equilib...The vapor-liquid equilibrium data of four binary systems (acetic acid +p-xylene, methyl acetate +n-propyl acetate, n-propyl acetate +p-xylene and methyl acetate +p-xylene) are measured at 101.33 kPa with Ellis equilibrium still, and then both the NRTL and UNIQUAC models are used in combination with the HOC model for correlating and estimating the vapor-liquid equilibrium of these four binary systems. The estimated binary VLE results using correlated parameters agree well with the measured data except the methyl acetate +p-xylene system which easily causes bumping and liquid rushing out of the sampling tap due to their dramatically different boiling points. The correlation results by NRTL and UNIQUAC models have little difference on the average absolute deviations of temperature and composition of vapor phase, and the results by NRTL model are slightly better than those by UNIQUAC model except for the methyl acetate +n-propyl acetate system, for which the latter gives more accurate correlations.展开更多
Vapor-liquid equilibrium(VLE) data were measured for ternary system water + ethanol + 1-butyl-3methylimidazolium acetate([bmim][OAc]),in a relatively wide range of ionic liquid(IL) mass fractions up to 0.8.Six sets of...Vapor-liquid equilibrium(VLE) data were measured for ternary system water + ethanol + 1-butyl-3methylimidazolium acetate([bmim][OAc]),in a relatively wide range of ionic liquid(IL) mass fractions up to 0.8.Six sets of complete T-x-y data were obtained,in which the mole fraction of ethanol on IL-free basis was fixed separately at 0.1,0.2,0.4,0.6,0.8,and approximate 0.98.The non-random-two-liquid(NRTL) and electrolyte non-random-two-liquid(eNRTL) equations were used for correlation,showing similar deviations.The ternary VLE was also modeled with the correlation from two data sets,with the mole fractions of ethanol on IL-free basis being 0.1 and approximate 0.98.The VLE data were also reproduced satisfactorily.With the eNRTL model,the root-mean-square deviation for temperature is 0.79 K and that for vapor-phase mole fraction is 0.0094.The calculations are in good agreement with experimental data.The effect of the IL on the VLE behavior of the volatile components is also illustrated.展开更多
The isobaric vapor-liquid equilibrium data of systems of ethyl acetate<sub>(1)</sub>-n-octane<sub>(2)</sub> andisopropyl acetate<sub>(1)</sub>-n-octane<sub>(2)</sub...The isobaric vapor-liquid equilibrium data of systems of ethyl acetate<sub>(1)</sub>-n-octane<sub>(2)</sub> andisopropyl acetate<sub>(1)</sub>-n-octane<sub>(2)</sub> were determined at 0.0709 MPa and 0.1013 MPa by using a modifiedRose-Williams still.The experimental data were tested for thermodynamical consistency and correlatedsatisfactorily with p-T equation of state and Wilson equation.展开更多
Prediction of vapor-liquid equilibrium (VLE) is extremely necessary to separate liquid mixture in chemical production, especially when the required experimental data are difficult to measure, or the measurement is not...Prediction of vapor-liquid equilibrium (VLE) is extremely necessary to separate liquid mixture in chemical production, especially when the required experimental data are difficult to measure, or the measurement is not economical. The infinite dilution activities can be used to predict VLE. However, it needs both the ends of the activities that are difficult to obtain for many systems. In the present study, a new model is proposed for correlating the frequency shift of C H stretching band of IR spectra over the whole concentration. Investigated mixtures in-clude water/2-propanol, water/N, N-dimethylformamide (DMF), water/methanol, water/ethanol, water/1, 4-dioxane, and water/dimethylsulfoxide (DMSO) systems. Simultaneous correlations of C H frequency shift and VLE data are made. Furthermore, the VLE data were predicted with satisfactory results by the parameters obtained from IR spectra coupled with one of the infinite dilution activity coefficients.展开更多
Green oxidation of cyclohexene using dioxygen as oxidizing agent is highly desirable because of its environmental compatibility and economic impact.Separation of its oxidation products depends on the reliable vaporliq...Green oxidation of cyclohexene using dioxygen as oxidizing agent is highly desirable because of its environmental compatibility and economic impact.Separation of its oxidation products depends on the reliable vaporliquid equilibrium(VLE) data of relevant components,which are still lacking.The VLE data of binary system 1,2-epoxycyclohexane and 2-cyclohexen-1-one under ambient pressure were obtained using an improved VLE equipment EC-2 still in this work.The results showed that this binary system has no azeotropic point.Furthermore,the experimental VLE data were correlated with the Wilson thermodynamic model and the corresponding binary interaction parameters of the model were obtained.The results showed that the VLE data agreed well with the model and passed the thermodynamic consistency test of Herrington.展开更多
The elucidation of vapor-liquid equilibrium (VLE) of the halogenated silane was necessary for the production of silicon derivatives, especially for methylvinyldichlorosilane, due to the lack of the relevant reports. I...The elucidation of vapor-liquid equilibrium (VLE) of the halogenated silane was necessary for the production of silicon derivatives, especially for methylvinyldichlorosilane, due to the lack of the relevant reports. Isobaric VLE for the system methyldichlorosilane-dimethyldichlorosilane-benzene and isobaric VLE of the three binary systems were measured with a new pump-ebulliometer at the pressure of 101.325 kPa. These binary compositions of the equilibrium vapor were calculated according to the Q function of molar excess Gibbs energy by the indirect method and the resulted VLE data agreed well with the thermo-dynamic consistency. Moreover, the experimental data were correlated with the Wilson, NRTL, Margules and van Laar equations by means of the least-squares fit, the acquired optimal interaction parameters were fitted to experimental vapor-liquid equilibrium data for binary systems. The binary parameters of Wilson equation were also used to calculate the bubble point temperature and the vapor phase composition for the ternary mixtures without any additional adjustment. The predicted vapor-liquid equilibrium for the ternary system was in a good agreement with the experimental results. The VLE of binary and multilateral systems provided essential theory for the production of the halogenated silane.展开更多
The phase behaviors of toluene/polycyclic aromatic hydrocarbon mixture systems were investigated with a continuous-flow type apparatus at 573.2, 598.2, 623.2 and 648.2 K, while the pressure changed from 1 to 5MPa. The...The phase behaviors of toluene/polycyclic aromatic hydrocarbon mixture systems were investigated with a continuous-flow type apparatus at 573.2, 598.2, 623.2 and 648.2 K, while the pressure changed from 1 to 5MPa. The pseudo-binary phase behaviors were predicted with the Peng-Robinson equation of state with interaction parameters between toluene and pseudo-components considered. The phase diagrams of the system have been classified following the category of phase boundary diagram models. The extraction selectivity and efficiency of tolu-ene as a solvent was discussed by comparing with that of hexane. The prediction model for selectivity was also suggested.展开更多
Isobaric vapor-liquid equilibrium(VLE) data for three binary systems, chlorobenzene + N,N-dimethylformamide, chlorobenzene + furfural, and chlorobenzene + benzaldehyde, were measured at 50.00 and 101.33 kPa using a mo...Isobaric vapor-liquid equilibrium(VLE) data for three binary systems, chlorobenzene + N,N-dimethylformamide, chlorobenzene + furfural, and chlorobenzene + benzaldehyde, were measured at 50.00 and 101.33 kPa using a modified Rose-Williams still. Gas chromatography was used to analyze the compositions of the samples and no azeotropic behavior was found. All of the measured VLE values were checked by the semi-empirical method proposed by Herington and the point-to-point Van Ness test method modified by Fredenslund. The experimental data were correlated by using the Wilson, the non-random two-liquid and universal quasi-chemical activity coefficient models. The corresponding parameters for the three models were obtained.展开更多
Isobaric vapor-liquid equilibrium (VLE) data were measured for binary mixtures of toluene+N- formylmorpholine, toluene+3-methylthiophene and 3-methylthiophene+N-formylmorpholine at 101.33 kPa. The VLE data of the bina...Isobaric vapor-liquid equilibrium (VLE) data were measured for binary mixtures of toluene+N- formylmorpholine, toluene+3-methylthiophene and 3-methylthiophene+N-formylmorpholine at 101.33 kPa. The VLE data of the binary systems were found to be thermodynamically consistent. The saturated vapor pressure calculated by CSGC-PR equation of the pure component had higher accuracy than that calculated by Antoine equation. The liquid- phase activity coefficients of the binary systems were calculated by the Wilson, NRTL and UNIFAC models, and the binary interaction parameters of the three models were determined by the VLE data. The Wilson model was selected as the most suitable model to predict the VLE data of the ternary system of toluene+3-methylthiophene+N- formylmorpholine. The relative volatility between toluene and 3-methylthiophene was also calculated. Moreover, the effect of N-formylmorpholine as solvent was studied. When the molar ratio of solvent to feed (S/F) was 7, the relative volatility reached 1.904, which is almost twice the relative volatility without solvent. Therefore, N-formylmorpholine can be considered as an effective extracting agent for the separation of the close-boiling mixture of toluene+3- methylthiophene by extractive distillation.展开更多
Equilibrium pressures and compositions for the binary mixture carbon dioxide-iso-pentane were measured on nine isotherms from 253K to the iso-pentane critical temperature. On each isotherm, the entire pressure range o...Equilibrium pressures and compositions for the binary mixture carbon dioxide-iso-pentane were measured on nine isotherms from 253K to the iso-pentane critical temperature. On each isotherm, the entire pressure range of phase coexistence was covered. The mixture critical line has been located and is shown to be contiuous in Pressure-Temperature-Composition (P-T-X) space between the critical points of the pure components. Comparisons are made between the experimental results obtained by Besserer-Robinson and this work with predictions of the Soave-Redlich Kwong, Peng-Robinson, Kubic-Martin, and Adachi-Lu-Sugle cubic equations of state. None was able to correlate the data within our estimated experimental error.展开更多
Vapor-liquid equilibrium composition and temperature were measured for binary andternary mixtures of benzene,toluene and p-xylene at 101.33 kPa The equilibrium cell of Boubliketal.was modified for the present study.Th...Vapor-liquid equilibrium composition and temperature were measured for binary andternary mixtures of benzene,toluene and p-xylene at 101.33 kPa The equilibrium cell of Boubliketal.was modified for the present study.The experimental vapor-liquid equilibrium data were corre-lated with the Wilson equation.展开更多
1 INTRODUCTIONVapor-liquid equilibrium(VLE)relations are required for practical use,such as in the designand operation of disitillation equipment.In the conventional experimental methods of vapor-liquid equilibria,som...1 INTRODUCTIONVapor-liquid equilibrium(VLE)relations are required for practical use,such as in the designand operation of disitillation equipment.In the conventional experimental methods of vapor-liquid equilibria,some analytical instruments are applied.They are time-consuming and dif-ficult for multicomponent system because the proper method for the composition analysis isnot easy to be set up.展开更多
The isobaric vapor-liquid equilibrium data of butanone1-N, N-dimethylformamide DMF2 at 100.92kPa, 93.32kPa, and 79.99kPa and of toluene1-DMF2 at 100.92kPa were measured using a modified Rose–Williams still. The above...The isobaric vapor-liquid equilibrium data of butanone1-N, N-dimethylformamide DMF2 at 100.92kPa, 93.32kPa, and 79.99kPa and of toluene1-DMF2 at 100.92kPa were measured using a modified Rose–Williams still. The above data met the thermodynamic consistency test and were correlated with the Wilson, NRTL, and UNIQUAC equations. These data can be used in the analysis and design of the process that involves separating DMF from butanone and toluene in the leather synthesis industry.展开更多
Isoplethic VLE data for the systems benzene-hexane at 9 different compositions in the temperature range from 298K to 331K, chloroform-benzene at 11 different compositions in the temperatuge range from 308K to 350K and...Isoplethic VLE data for the systems benzene-hexane at 9 different compositions in the temperature range from 298K to 331K, chloroform-benzene at 11 different compositions in the temperatuge range from 308K to 350K and chloroform-hexane at 9 different compomtions in the temperatuge range faxnn 311K to 337K were determined by using an inclined ebulHometer with a pump-like stirrer. Isothermal and isobaric VLE were cak-ulated from the isoplethic results with a extended UNIQUAC equation and these date agree well with the literature data.展开更多
The amount of ethylene in refinery off-gas is high with a mass fraction of 20%,but the refinery off-gas is usually used as fuel gas in most refineries.The separation and recovery of ethylene is of remarkable significa...The amount of ethylene in refinery off-gas is high with a mass fraction of 20%,but the refinery off-gas is usually used as fuel gas in most refineries.The separation and recovery of ethylene is of remarkable significance for saving energy and reducing carbon dioxide emission.The aim of this paper is to use a novel absorbent mesitylene for the ethylene absorption process and assess its application feasibility through the ethylene + mesitylene vapor-liquid equilibrium data measurement and its binary interaction parameter correlation,as well as the simulation for ethylene separation process.展开更多
In this study,three semipredictive activity coefficient models:Wilson,non-random-two liquid model(NRTL),and universal quasi-chemical model(UNIQUAC),have been used for modeling vapor-liquid equilibrium properties of te...In this study,three semipredictive activity coefficient models:Wilson,non-random-two liquid model(NRTL),and universal quasi-chemical model(UNIQUAC),have been used for modeling vapor-liquid equilibrium properties of ternary mixtures that include substances found in alcoholic distillation processes of wine and musts.In particular,vapor-liquid equilibrium in ternary mixtures containing water + ethanol + congener has been modeled using parameters obtained from binary and ternary mixture data.The congeners are substances that although present in very low concentrations,of the order of part per million,are important enological parameters.The results given by these different models have been compared with literature data and conclusions about the accuracy of the models studied are drawn,recommending the best models for correlating and predicting phase equilibrium properties of this type of mixtures.展开更多
基金supported by the National Natural Science Foundation of China(22068024).
文摘At present,the environment impact of refrigerants has been given attention.The binary mixture R152a/R1234ze(E)is an environmentally friendly refrigerant,which solves problems of poor cooling performance of the R1234ze(E)cycle and flammability of R152a.In order to obtain its basic thermal and physical parameters,it is necessary to carry out vapor-liquid equilibrium(VLE)research,and the cubic equation of states(EOS)is often used in the calculation of the thermodynamic properties of mixtures.In this paper,the VLE predicted models for R152a/R1234ze(E)in the temperature range of 298.15-328.15 K were constructed using Soave-Redlich-Kwong(SRK),Peng-Robinson(PR)equations of state(EOS)combined with van der Waals(vd W),Huron-Vidal(HV)mixing rules,respectively.The equilibrium pressures and vapor-phase mole fractions of the models were obtained by calculation,and all four models presented an extreme correlation with the experimental data.And it can be concluded that the calculated results of the PR+HV model are closer to the experimental data than those of the other three models,with the average absolute deviation of 0.0027 for vapor-phase mole fraction(AAD(ycal))and the average absolute relative deviation of 0.243%for equilibrium pressure(AARD(pcal)),which provides a basis for accurately calculating the thermophysical properties of the mixture R152a/R1234ze(E).
基金the support of the National Natural Science Foundation of China(21908131)the Natural Science Foundation of Shandong Province(ZR2019BB066)+1 种基金A Project of Shandong Province Higher Educational Science and Technology Program(J18KA072)Open Project of Qingdao University of Science and Technology Chemistry Department(QUSTHX202007)。
文摘Based on the COSMO-SAC model,1-ethyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium p-toluenesulfonate were selected from 30 ILs as entrainers to investigate the separation of the isopropyl alcohol+isopropyl acetate azeotrope.Two screening indicators,σ-profile and infinite dilution selectivity(S^(∞)),were adopted as the basis.The iso baric vapor-liquid equilibrium experiments for isopropyl alcohol+isopropyl acetate binary system and isopropyl alcohol+isopropyl acetate+confirmed ILs ternary systems were performed at the pressure of atmospheric pressure.The experimental measurement demonstrated that the adopt ILs enhanced the relative volatility of the above alcohol-ester azeotrope,leading to the elimination of the azeotropic point with a certain amount ILs.Meanwhile,the thermodynamic correlation for two systems containing ILs was explored with the NRTL model,which also reflects the extensive applicability of that by comparing the deviation between experimental and calculated data.And its binary interaction parameters were regressed,which can provide a basis for its simulation process.
基金Supported by the Natural Science Foundation of Jiangxi Province(No.0020019).
文摘Vapor-liquid euilibrium (VLE) for a ternary system of Methyldichlorosilane+methylvinyldichlorosilane+toluene and constituent binary systems were measured at 101.3kPa using a new type of magnetical pump-ebulliometer,The equilibrium conpositions of the vapor phase of binary systems were calculated indirectly from the total pressure-temperature-liquid composition(pTx).The experimental data were correlated with the Wilson and NRTL(non-random two liquid )equations.The parameters of the Wilson moldel were employed to predict the ternary VLE data .The calculated boiling points were in good agreement with the experimental ones.
基金Supported by the Major State Basic Research Development Program of China (2012CB720500), the National Natural Science Foundation of China (U1162202, 61174118) and the Shanghai Leading Academic Discipline Project (B504).
文摘The vapor-liquid equilibrium data of four binary systems (acetic acid +p-xylene, methyl acetate +n-propyl acetate, n-propyl acetate +p-xylene and methyl acetate +p-xylene) are measured at 101.33 kPa with Ellis equilibrium still, and then both the NRTL and UNIQUAC models are used in combination with the HOC model for correlating and estimating the vapor-liquid equilibrium of these four binary systems. The estimated binary VLE results using correlated parameters agree well with the measured data except the methyl acetate +p-xylene system which easily causes bumping and liquid rushing out of the sampling tap due to their dramatically different boiling points. The correlation results by NRTL and UNIQUAC models have little difference on the average absolute deviations of temperature and composition of vapor phase, and the results by NRTL model are slightly better than those by UNIQUAC model except for the methyl acetate +n-propyl acetate system, for which the latter gives more accurate correlations.
基金Supported by the National Natural Science Foundation of China (20776132)
文摘Vapor-liquid equilibrium(VLE) data were measured for ternary system water + ethanol + 1-butyl-3methylimidazolium acetate([bmim][OAc]),in a relatively wide range of ionic liquid(IL) mass fractions up to 0.8.Six sets of complete T-x-y data were obtained,in which the mole fraction of ethanol on IL-free basis was fixed separately at 0.1,0.2,0.4,0.6,0.8,and approximate 0.98.The non-random-two-liquid(NRTL) and electrolyte non-random-two-liquid(eNRTL) equations were used for correlation,showing similar deviations.The ternary VLE was also modeled with the correlation from two data sets,with the mole fractions of ethanol on IL-free basis being 0.1 and approximate 0.98.The VLE data were also reproduced satisfactorily.With the eNRTL model,the root-mean-square deviation for temperature is 0.79 K and that for vapor-phase mole fraction is 0.0094.The calculations are in good agreement with experimental data.The effect of the IL on the VLE behavior of the volatile components is also illustrated.
文摘The isobaric vapor-liquid equilibrium data of systems of ethyl acetate<sub>(1)</sub>-n-octane<sub>(2)</sub> andisopropyl acetate<sub>(1)</sub>-n-octane<sub>(2)</sub> were determined at 0.0709 MPa and 0.1013 MPa by using a modifiedRose-Williams still.The experimental data were tested for thermodynamical consistency and correlatedsatisfactorily with p-T equation of state and Wilson equation.
基金Supported by the National Natural Science Foundation of China (No.20573093 and No.20434020).
文摘Prediction of vapor-liquid equilibrium (VLE) is extremely necessary to separate liquid mixture in chemical production, especially when the required experimental data are difficult to measure, or the measurement is not economical. The infinite dilution activities can be used to predict VLE. However, it needs both the ends of the activities that are difficult to obtain for many systems. In the present study, a new model is proposed for correlating the frequency shift of C H stretching band of IR spectra over the whole concentration. Investigated mixtures in-clude water/2-propanol, water/N, N-dimethylformamide (DMF), water/methanol, water/ethanol, water/1, 4-dioxane, and water/dimethylsulfoxide (DMSO) systems. Simultaneous correlations of C H frequency shift and VLE data are made. Furthermore, the VLE data were predicted with satisfactory results by the parameters obtained from IR spectra coupled with one of the infinite dilution activity coefficients.
基金Supported by Outstanding Personality Innovation Funds of Henan Province (0121001900)
文摘Green oxidation of cyclohexene using dioxygen as oxidizing agent is highly desirable because of its environmental compatibility and economic impact.Separation of its oxidation products depends on the reliable vaporliquid equilibrium(VLE) data of relevant components,which are still lacking.The VLE data of binary system 1,2-epoxycyclohexane and 2-cyclohexen-1-one under ambient pressure were obtained using an improved VLE equipment EC-2 still in this work.The results showed that this binary system has no azeotropic point.Furthermore,the experimental VLE data were correlated with the Wilson thermodynamic model and the corresponding binary interaction parameters of the model were obtained.The results showed that the VLE data agreed well with the model and passed the thermodynamic consistency test of Herrington.
基金Project supported by the Foundation of Science and Technology of the Ministry of Education (No. 03071) and the Natural Science Foundation of Jiangxi Province (No. 0320013), China
文摘The elucidation of vapor-liquid equilibrium (VLE) of the halogenated silane was necessary for the production of silicon derivatives, especially for methylvinyldichlorosilane, due to the lack of the relevant reports. Isobaric VLE for the system methyldichlorosilane-dimethyldichlorosilane-benzene and isobaric VLE of the three binary systems were measured with a new pump-ebulliometer at the pressure of 101.325 kPa. These binary compositions of the equilibrium vapor were calculated according to the Q function of molar excess Gibbs energy by the indirect method and the resulted VLE data agreed well with the thermo-dynamic consistency. Moreover, the experimental data were correlated with the Wilson, NRTL, Margules and van Laar equations by means of the least-squares fit, the acquired optimal interaction parameters were fitted to experimental vapor-liquid equilibrium data for binary systems. The binary parameters of Wilson equation were also used to calculate the bubble point temperature and the vapor phase composition for the ternary mixtures without any additional adjustment. The predicted vapor-liquid equilibrium for the ternary system was in a good agreement with the experimental results. The VLE of binary and multilateral systems provided essential theory for the production of the halogenated silane.
文摘The phase behaviors of toluene/polycyclic aromatic hydrocarbon mixture systems were investigated with a continuous-flow type apparatus at 573.2, 598.2, 623.2 and 648.2 K, while the pressure changed from 1 to 5MPa. The pseudo-binary phase behaviors were predicted with the Peng-Robinson equation of state with interaction parameters between toluene and pseudo-components considered. The phase diagrams of the system have been classified following the category of phase boundary diagram models. The extraction selectivity and efficiency of tolu-ene as a solvent was discussed by comparing with that of hexane. The prediction model for selectivity was also suggested.
基金supported by State Key Laboratory of Chemical Engineering Foundation
文摘Isobaric vapor-liquid equilibrium(VLE) data for three binary systems, chlorobenzene + N,N-dimethylformamide, chlorobenzene + furfural, and chlorobenzene + benzaldehyde, were measured at 50.00 and 101.33 kPa using a modified Rose-Williams still. Gas chromatography was used to analyze the compositions of the samples and no azeotropic behavior was found. All of the measured VLE values were checked by the semi-empirical method proposed by Herington and the point-to-point Van Ness test method modified by Fredenslund. The experimental data were correlated by using the Wilson, the non-random two-liquid and universal quasi-chemical activity coefficient models. The corresponding parameters for the three models were obtained.
文摘Isobaric vapor-liquid equilibrium (VLE) data were measured for binary mixtures of toluene+N- formylmorpholine, toluene+3-methylthiophene and 3-methylthiophene+N-formylmorpholine at 101.33 kPa. The VLE data of the binary systems were found to be thermodynamically consistent. The saturated vapor pressure calculated by CSGC-PR equation of the pure component had higher accuracy than that calculated by Antoine equation. The liquid- phase activity coefficients of the binary systems were calculated by the Wilson, NRTL and UNIFAC models, and the binary interaction parameters of the three models were determined by the VLE data. The Wilson model was selected as the most suitable model to predict the VLE data of the ternary system of toluene+3-methylthiophene+N- formylmorpholine. The relative volatility between toluene and 3-methylthiophene was also calculated. Moreover, the effect of N-formylmorpholine as solvent was studied. When the molar ratio of solvent to feed (S/F) was 7, the relative volatility reached 1.904, which is almost twice the relative volatility without solvent. Therefore, N-formylmorpholine can be considered as an effective extracting agent for the separation of the close-boiling mixture of toluene+3- methylthiophene by extractive distillation.
文摘Equilibrium pressures and compositions for the binary mixture carbon dioxide-iso-pentane were measured on nine isotherms from 253K to the iso-pentane critical temperature. On each isotherm, the entire pressure range of phase coexistence was covered. The mixture critical line has been located and is shown to be contiuous in Pressure-Temperature-Composition (P-T-X) space between the critical points of the pure components. Comparisons are made between the experimental results obtained by Besserer-Robinson and this work with predictions of the Soave-Redlich Kwong, Peng-Robinson, Kubic-Martin, and Adachi-Lu-Sugle cubic equations of state. None was able to correlate the data within our estimated experimental error.
文摘Vapor-liquid equilibrium composition and temperature were measured for binary andternary mixtures of benzene,toluene and p-xylene at 101.33 kPa The equilibrium cell of Boubliketal.was modified for the present study.The experimental vapor-liquid equilibrium data were corre-lated with the Wilson equation.
基金Supported by the National Natural Science Foundation of China
文摘1 INTRODUCTIONVapor-liquid equilibrium(VLE)relations are required for practical use,such as in the designand operation of disitillation equipment.In the conventional experimental methods of vapor-liquid equilibria,some analytical instruments are applied.They are time-consuming and dif-ficult for multicomponent system because the proper method for the composition analysis isnot easy to be set up.
基金the National Natural Science Foundation of China (No.20376073)
文摘The isobaric vapor-liquid equilibrium data of butanone1-N, N-dimethylformamide DMF2 at 100.92kPa, 93.32kPa, and 79.99kPa and of toluene1-DMF2 at 100.92kPa were measured using a modified Rose–Williams still. The above data met the thermodynamic consistency test and were correlated with the Wilson, NRTL, and UNIQUAC equations. These data can be used in the analysis and design of the process that involves separating DMF from butanone and toluene in the leather synthesis industry.
基金Supported by Zhejiang Provincial Natural Science Foundation of China.
文摘Isoplethic VLE data for the systems benzene-hexane at 9 different compositions in the temperature range from 298K to 331K, chloroform-benzene at 11 different compositions in the temperatuge range from 308K to 350K and chloroform-hexane at 9 different compomtions in the temperatuge range faxnn 311K to 337K were determined by using an inclined ebulHometer with a pump-like stirrer. Isothermal and isobaric VLE were cak-ulated from the isoplethic results with a extended UNIQUAC equation and these date agree well with the literature data.
基金Supported by the National Natural Science Foundation of China (50890184) the National Basic Research Program of China (2011CB201306)
文摘The amount of ethylene in refinery off-gas is high with a mass fraction of 20%,but the refinery off-gas is usually used as fuel gas in most refineries.The separation and recovery of ethylene is of remarkable significance for saving energy and reducing carbon dioxide emission.The aim of this paper is to use a novel absorbent mesitylene for the ethylene absorption process and assess its application feasibility through the ethylene + mesitylene vapor-liquid equilibrium data measurement and its binary interaction parameter correlation,as well as the simulation for ethylene separation process.
基金Supported by the Direction of Research of the University of La Serena-Chile (220-2-05 and 220-2-21)the National Council for Scientific and Technological Research,CONICYT (FONDECYT 3020020)
文摘In this study,three semipredictive activity coefficient models:Wilson,non-random-two liquid model(NRTL),and universal quasi-chemical model(UNIQUAC),have been used for modeling vapor-liquid equilibrium properties of ternary mixtures that include substances found in alcoholic distillation processes of wine and musts.In particular,vapor-liquid equilibrium in ternary mixtures containing water + ethanol + congener has been modeled using parameters obtained from binary and ternary mixture data.The congeners are substances that although present in very low concentrations,of the order of part per million,are important enological parameters.The results given by these different models have been compared with literature data and conclusions about the accuracy of the models studied are drawn,recommending the best models for correlating and predicting phase equilibrium properties of this type of mixtures.