Entity

Time filter

Source Type


Gao D.,Hefei University | Gao D.,Sino German Research Center for Process Engineering and Energy Technology | Zhang H.,Hefei University | Zhang H.,Sino German Research Center for Process Engineering and Energy Technology | And 10 more authors.
Journal of Thermodynamics | Year: 2012

Vapor-liquid equilibrium (VLE) data for the strongly associated ternary system methanol + water + ethanoic acid and the three constituent binary systems have been determined by the total pressure-temperature-liquid-phase composition-molar excess enthalpy of mixing of the liquid phase (p, T, x, H m E) for the binary systems using a novel pump ebulliometer at 101.325 kPa. The vapor-phase compositions of these binary systems had been calculated from Tpx and H m E based on the Q function of molar excess Gibbs energy through an indirect method. Moreover, the experimental T, x data are used to estimate nonrandom two-liquid (NRTL), Wilson, Margules, and van Laar model parameters, and these parameters in turn are used to calculate vapor-phase compositions. The activity coefficients of the solution were correlated with NRTL, Wilson, Margules, and van Laar models through fitting by least-squares method. The VLE data of the ternary system were well predicted from these binary interaction parameters of NRTL, Wilson, Margules, and van Laar model parameters without any additional adjustment to build the thermodynamic model of VLE for the ternary system and obtain the vapor-phase compositions and the calculated bubble points. © 2012 Daming Gao et al. Source


Gao D.,Hefei University | Gao D.,Sino German Research Center for Process Engineering and Energy Technology | Zhang J.,Hefei University | Zhu D.,Hefei University | And 6 more authors.
Huagong Xuebao/CIESC Journal | Year: 2012

Isobaric vapor-liquid equilibrium (VLE) data at 101.325 kPa for the three binary systems containing dimethyl sulfide-pyridine, dimethyl sulfide-N, N-dimetylacetamide and pyridine-N, N-dimetylacetamide and the ternary system containing dimethyl sulfide-pyridine-N, N-dimetylacetamide were measured by different liquid phase compositions using an ebullionmeter. The activity coefficients were correlated with the Wilson, NRTL, Margules, van Laar and UNIQUAC models. The experimental T-x data are used to these model parameters through the least square method, and these parameters in turn are used to calculate vapor-phase compositions. Moreover, the vapor-phase compositions had been predicted from Tpx according to the function of molar excess Gibbs energy by the indirect method. The activity coefficients are useful to calculate excess Gibbs function for the three binary systems. The VLE data of the ternary system were correlated based on Wilson, NRTL, Margules, van Laar and UNIQUAC model parameters of these binary systems in order to build the thermodynamic model of VLE for the ternary system and obtain the vapor-phase compositions and the calculated bubble points, respectively. The thermodynamic consistency of the experimental VLE data were checked out by means of the Herington test for the binary systems and the McDermott-Ellis test for the ternary system, respectively, and the results showed that VLE data for these systems strictly satisfied thermodynamic consistency. © All Rights Reserved. Source


Zhu D.-C.,Hefei University | Zhu D.-C.,Sino German Research Center for Process Engineering and Energy Technology | Xu F.-F.,Hefei University | Gao D.-M.,Hefei University | And 7 more authors.
Gao Xiao Hua Xue Gong Cheng Xue Bao/Journal of Chemical Engineering of Chinese Universities | Year: 2013

Isobaric vapor-liquid equilibrium (VLE) data of thiophene-pyridine-dimethyl sulfoxide ternary system and three constituent binary systems with different liquid phase composition were measured by using a pump-ebullionmeter. The three binary systems were correlated with the Wilson, NRTL, Margules and van Laar models, respectively. The VLE data correlation results of the three binary systems show that the NRTL model is much better than the other models, and its average absolute values of temperature deviation of above three binary systems are 0.13 K, 0.27 K and 0.39 K, respectively. The VLE data of the ternary system were evaluated by respectively using the different parameters obtained from above three binary systems with the four different models, and then from the evaluation of the VLE data, the vapor-phase compositions y and the calculated bubble point were obtained. The thermodynamic consistency of the VLE data were checked by means of the Herington test for the binary systems and the McDermott-Ellis test for the ternary system, respectively, and the results show that the VLE data of these systems strictly satisfy the thermodynamic consistency. Source


Zhu D.,Hefei University | Zhu D.,Sino German Research Center for Process Engineering and Energy Technology | Gao D.,Hefei University | Gao D.,Sino German Research Center for Process Engineering and Energy Technology | And 12 more authors.
Journal of Chemical and Engineering Data | Year: 2013

It has relatively been difficult to accurately correlate and predict vapor-liquid equilibrium (VLE) data for the strongly associating system containing the carboxyl acid due to its monomer undergoing partial dimerization and even higher polymerization in the vapor and liquid phases. Herein, this paper reports that the formation state for the associating component mainly has been the existence of dimer in the vapor and liquid phases through the geometric structures of ethanoic acid investigated theoretically with density functional theory (DFT), and the VLE data for the associating ternary system ethanal + ethanol + ethanoic acid and the three constituent binary systems were measured using a recirculating still at 101.325 kPa. Marek's chemical theory was considered due to the associating species as the dimer existence in the both phases. The three experimental binary data sets were independently correlated using nonrandom two-liquid (NRTL), Wilson, and universal quasichemical activity coefficient (UNIQUAC) model, respectively, and the binary parameters were applied to predict the VLE data for ternary system without any additional adjustment. By comparison with the measured values, the ternary equilibrium values predicted agreed well with the measured values in this way. The thermodynamic consistency of the experimental VLE data was checked out by means of the Wisniak's L-W test for the binary systems and the Wisniak-Tamir's modification of McDermott-Ellis test for the ternary system, respectively. © 2012 American Chemical Society. Source


Gao D.,Hefei University | Gao D.,Sino German Research Center for Process Engineering and Energy Technology | Zhang H.,Hefei University | Zhang H.,Sino German Research Center for Process Engineering and Energy Technology | And 12 more authors.
Industrial and Engineering Chemistry Research | Year: 2012

The vapor-liquid equilibrium (VLE) data for the diethyl ether + methanol + 1-butanol ternary system and three constituent binary systems were measured at different liquid phase compositions using a dynamic recirculating still at 101.325 kPa. The activity coefficients of the solution were correlated with the Wilson, nonrandom two-liquid (NRTL), Margules, van Laar, and universal quasichemical activity coefficient (UNIQUAC) models through the fit of least-squares method. In addition, the VLE data of the ternary system were also predicted from these binary interaction parameters of Wilson, NRTL, Margules, van Laar, and UNIQUAC model parameters without any additional adjustment, which obtained the calculated vapor-phase compositions and bubble points compared with the measured values. The calculated bubble points with the model parameters of activity coefficients were in good agreement with the experimental data. The ASOG group contribution method also was used for prediction of the three binary systems. The thermodynamic consistency of the experimental VLE data was checked out by means of the Wisniak's L-W test for the binary systems and the Wisniak-Tamir's modification of McDermott-Ellis test for the ternary system, respectively. © 2011 American Chemical Society. Source

Discover hidden collaborations