NRTL equation is one of the equations that widely used in chemical engineering thermodynamics. The marked advantage of the NRTL equation is that it can be used for predicting the thermodynamicsproperties of multicompo...NRTL equation is one of the equations that widely used in chemical engineering thermodynamics. The marked advantage of the NRTL equation is that it can be used for predicting the thermodynamicsproperties of multicomponent systems only with the data of binary systems. However the application of it to molten alloys and the other melts in metallungy has been mrsly reported. In this article, it was used to correlate thermodynamics data of binary molten alloys which are included in the systems-Cd-Bi-Sn, Cd-Bi-Pb, Cd-Sn-Pb. The data of those ternary systems were predicted by NRTL equation. The activities of Cd in quaternary system Cd-Bi-Pb-Sn were also calculated.展开更多
A new equation for predicting surface tension is proposed based on the thermodynamic definition of surface tension and the expression of the Gibbs free energy of the system. Using the NRTL equation to represent the ex...A new equation for predicting surface tension is proposed based on the thermodynamic definition of surface tension and the expression of the Gibbs free energy of the system. Using the NRTL equation to represent the excess Gibbs free energy, a two-parameter surface tension equation is derived. The feasibility of the new equation has been tested in terms of 124 binary and 16 multicomponent systems(13-ternary and 3-quaternary) with absolute relative deviations of 0.59% and 1.55% respectively. This model is also predictive for the temperature dependence of surface tension of liquid mixtures. It is shown that, with good accuracy, this equation is simple and reliable for practical use.展开更多
The non-random two liquids （NRTL） equation together with the Pitzer/Curl Virial equation of state are used to investigate the simultaneous representation of excess enthalpies （h^E） and vapour-liquid equilibria （...The non-random two liquids （NRTL） equation together with the Pitzer/Curl Virial equation of state are used to investigate the simultaneous representation of excess enthalpies （h^E） and vapour-liquid equilibria （VLE） and the VLE prediction from h^E data. The calculation strategy for properly determining NRTL parameters and the effect of their temperature dependence on the simultaneous correlation of h^E and VLE data and the VLE extrapolation are analysed in detail.展开更多
KF or K2CO3 was added into the 1-butanol-water system and two phases were formed： water-rich phase （water phase） and 1-butanol-rich phase （1-butanol phase）. The liquid liquid equilibrium （LLE） data for 1-butano...KF or K2CO3 was added into the 1-butanol-water system and two phases were formed： water-rich phase （water phase） and 1-butanol-rich phase （1-butanol phase）. The liquid liquid equilibrium （LLE） data for 1-butanol-water-KF and 1-butanol-water-K2CO3 systems were measured at 25℃ and showed that 1-butanol phase contained negligible salt and water phase contained negligible 1-butanol when the concentrations of KF and K2CO3 in the water phase were equal to or higher than 27.11% and 31.68% , respectively. Thus water could be separated efficiently from 1-butanol-water by adding KF or K2CO3 into the system. A theoretical calculation of LLE data was calculated by using the Pitzer theory to get water activity in the water phase, and by the models, such as the Wilson, NRTL or the UNIQUAC for the 1-butanol phase. For 1-hutanol-water-KF system, the experimental data were found in good agreement with the calculated results by using Pitzer theory and Wilson equa tion, while for 1-butanol-water-K2CO3 system, the experimental data were found in good agreement with the calculated results by using Pitzer theory and UNIQUAC eauation.展开更多
By using the laser-monitoring technique,solid-liquid equilibrium data of glutaric acid in cyclohexanol,cyclohexanone,their five mixed solvents and acetic acid were measured within the temperature range from 292.15K to...By using the laser-monitoring technique,solid-liquid equilibrium data of glutaric acid in cyclohexanol,cyclohexanone,their five mixed solvents and acetic acid were measured within the temperature range from 292.15K to 354.60K by dynamic method.Empirical formula and λh equation were used to correlate the solubilities of glutaric acid in eight solvents.The maximal average relative deviations were 1.15% and 2.20% by using the em-pirical formula and λh equation to correlate the solubility data.The results showed that the empirical formula and λh model could correlate the solubility data of glutaric acid in eight solvents.In addition,the solubility data of glutaric acid in five mixtures(cyclohexanone+cyclohexanol)could be predicted with the NRTL equation utilizing the pa-rameters of the binary systems.The total average relative deviation was 3.60%.The results indicate that the NRTL equation could well predict the solubilities of glutaric acid in the mixed solvents of cyclohexanone and cyclohexanol.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
Many by-products are generated in the process of oxidizing cyclohexene to produce 1,2-epoxycyclohexane by hydrogen peroxide, including cyclohexanol, cyclohexanone, etc. To obtain high-purity 1,2-epoxycyclohexane, the ...Many by-products are generated in the process of oxidizing cyclohexene to produce 1,2-epoxycyclohexane by hydrogen peroxide, including cyclohexanol, cyclohexanone, etc. To obtain high-purity 1,2-epoxycyclohexane, the by-products must be removed through rectification. Refining 1,2-epoxycyclohexane through rectification requires vapor-liquid equilibrium(VLE) data of the related system. Therefore, the VLE data of 1,2-epoxycyclohexane- cyc-lohexanone system were measured at 101.3 kPa using an improved EC-2 VLE still. The thermodynamic consistency of the data was then tested by Herington's method and the rigorous point-to-point method. The results obtained were exemplary. The VLE data were correlated by the Wilson and non-random two-liquid(NRTL) equations, using the error sum squares of the vapor composition as the objective function to obtain the model parameters. The difference between the calculated values and the experimental data is minor, indicating that the VLE data are suitable for engineering design.展开更多
文摘NRTL equation is one of the equations that widely used in chemical engineering thermodynamics. The marked advantage of the NRTL equation is that it can be used for predicting the thermodynamicsproperties of multicomponent systems only with the data of binary systems. However the application of it to molten alloys and the other melts in metallungy has been mrsly reported. In this article, it was used to correlate thermodynamics data of binary molten alloys which are included in the systems-Cd-Bi-Sn, Cd-Bi-Pb, Cd-Sn-Pb. The data of those ternary systems were predicted by NRTL equation. The activities of Cd in quaternary system Cd-Bi-Pb-Sn were also calculated.
基金the Scientific Research Foundation of the State Education Ministry for Returned Overseas Chinese Scholar.
文摘A new equation for predicting surface tension is proposed based on the thermodynamic definition of surface tension and the expression of the Gibbs free energy of the system. Using the NRTL equation to represent the excess Gibbs free energy, a two-parameter surface tension equation is derived. The feasibility of the new equation has been tested in terms of 124 binary and 16 multicomponent systems(13-ternary and 3-quaternary) with absolute relative deviations of 0.59% and 1.55% respectively. This model is also predictive for the temperature dependence of surface tension of liquid mixtures. It is shown that, with good accuracy, this equation is simple and reliable for practical use.
基金Supported by Deutsche Forschungsgemeinschaft(DFG) (LE 886/4-1)
文摘The non-random two liquids （NRTL） equation together with the Pitzer/Curl Virial equation of state are used to investigate the simultaneous representation of excess enthalpies （h^E） and vapour-liquid equilibria （VLE） and the VLE prediction from h^E data. The calculation strategy for properly determining NRTL parameters and the effect of their temperature dependence on the simultaneous correlation of h^E and VLE data and the VLE extrapolation are analysed in detail.
文摘KF or K2CO3 was added into the 1-butanol-water system and two phases were formed： water-rich phase （water phase） and 1-butanol-rich phase （1-butanol phase）. The liquid liquid equilibrium （LLE） data for 1-butanol-water-KF and 1-butanol-water-K2CO3 systems were measured at 25℃ and showed that 1-butanol phase contained negligible salt and water phase contained negligible 1-butanol when the concentrations of KF and K2CO3 in the water phase were equal to or higher than 27.11% and 31.68% , respectively. Thus water could be separated efficiently from 1-butanol-water by adding KF or K2CO3 into the system. A theoretical calculation of LLE data was calculated by using the Pitzer theory to get water activity in the water phase, and by the models, such as the Wilson, NRTL or the UNIQUAC for the 1-butanol phase. For 1-hutanol-water-KF system, the experimental data were found in good agreement with the calculated results by using Pitzer theory and Wilson equa tion, while for 1-butanol-water-K2CO3 system, the experimental data were found in good agreement with the calculated results by using Pitzer theory and UNIQUAC eauation.
文摘By using the laser-monitoring technique,solid-liquid equilibrium data of glutaric acid in cyclohexanol,cyclohexanone,their five mixed solvents and acetic acid were measured within the temperature range from 292.15K to 354.60K by dynamic method.Empirical formula and λh equation were used to correlate the solubilities of glutaric acid in eight solvents.The maximal average relative deviations were 1.15% and 2.20% by using the em-pirical formula and λh equation to correlate the solubility data.The results showed that the empirical formula and λh model could correlate the solubility data of glutaric acid in eight solvents.In addition,the solubility data of glutaric acid in five mixtures(cyclohexanone+cyclohexanol)could be predicted with the NRTL equation utilizing the pa-rameters of the binary systems.The total average relative deviation was 3.60%.The results indicate that the NRTL equation could well predict the solubilities of glutaric acid in the mixed solvents of cyclohexanone and cyclohexanol.
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 the Key Scientific and Technology Project of Henan Province(132102210050)
文摘Many by-products are generated in the process of oxidizing cyclohexene to produce 1,2-epoxycyclohexane by hydrogen peroxide, including cyclohexanol, cyclohexanone, etc. To obtain high-purity 1,2-epoxycyclohexane, the by-products must be removed through rectification. Refining 1,2-epoxycyclohexane through rectification requires vapor-liquid equilibrium(VLE) data of the related system. Therefore, the VLE data of 1,2-epoxycyclohexane- cyc-lohexanone system were measured at 101.3 kPa using an improved EC-2 VLE still. The thermodynamic consistency of the data was then tested by Herington's method and the rigorous point-to-point method. The results obtained were exemplary. The VLE data were correlated by the Wilson and non-random two-liquid(NRTL) equations, using the error sum squares of the vapor composition as the objective function to obtain the model parameters. The difference between the calculated values and the experimental data is minor, indicating that the VLE data are suitable for engineering design.
