首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
In this paper, (vapour + liquid) equilibrium (VLE) for the {1,1-difluoroethane (R152a) + 1,1,1,3,3-pentafluoropropane (R245fa)} system was determined by a static-analytical method at T = (323.150 to 353.150) K. Values of the VLE were correlated by the Peng–Robison equation of state (PR EoS) using two different models, the van der Waals (vdWs) mixing rule and the Huron–Vidal (HV) mixing rule involving the non-random two-liquid (NRTL) activity coefficient model. The correlated results show good agreement with the experimental values. For the two models, the maximum average absolute deviations of the vapour phase mole fraction are 0.0034 and 0.0035, respectively.  相似文献   

2.
Binary (vapour + liquid) equilibrium data were obtained for the {1,1-difluoroethane (HFC-152a) + n-butane (HC-600)} system at temperatures from 313.15 K to 363.15 K. These experiments were carried out with a circulating-type apparatus with on-line gas chromatography. The experimental data were correlated well by Peng–Robinson equation of state using the Wong–Sandler mixing rules. This system shows positive azeotropic phase behaviour.  相似文献   

3.
(Vapour + liquid) equilibrium (VLE) data for the binary systems of {1,1,2,2-tetrafluoroethane (R134) + propane (R290)} and {1,1,2,2-tetrafluoroethane (R134) + isobutane (R600a)} were measured with a recirculation method at the temperatures ranging from (263.15 to 278.15) K and (268.15 to 288.15) K, respectively. All of the data were correlated by the Peng–Robinson (PR) equation of state (EoS) with the Huron–Vidal (HV) mixing rules utilizing the non-random two-liquid (NRTL) activity coefficient model. Good agreement can be found between the experimental data and the correlated results. Azeotropic behaviour can be found at the measured temperature ranges for these two mixtures.  相似文献   

4.
5.
(Vapour + liquid) equilibrium (VLE) data for the binary system of {trifluoroiodomethane (R13I1) + trans-1, 3, 3, 3-tetrafluoropropene (R1234ze (E))} were measured by a static-analytic method within the temperature range of (258.150 to 298.150) K. The experimental data were correlated using the Peng–Robinson equation of state (PR EoS) with the Huron–Vidal (HV) mixing rule involving the NRTL activity coefficient model. The results show good agreement with experimental values for the binary system at each temperature point. The maximum average absolute relative deviation of pressure is 0.28%, while the maximum average absolute deviation of vapour phase mole fraction is 0.0025. Obviously azeotropic behaviour can be found for the measured temperature range here.  相似文献   

6.
Accurate thermo-physical data are of utmost interest for the development of new efficient refrigeration systems. Carbon dioxide (R744) and 1,1-difluoroethane (R152a) are addressed here. Isothermal (vapor + liquid) equilibrium data are reported herein for (R744 + R152a) binary system in the (258–343) K temperature range and in the (0.14 to 7.65) MPa pressure range. A reliable “static-analytic” method taking advantage of two online ROLSI? micro capillary samplers is used for all thermodynamic measurements. The data are correlated using our in-house ThermoSoft thermodynamic model using the Peng–Robinson equation of state, the Mathias–Copeman alpha function, the Wong–Sandler mixing rules, and the NRTL model.  相似文献   

7.
In this paper, the (vapor + liquid) equilibrium data for (R13I1 + R290) were measured by a vapor-recirculation apparatus at temperatures from (258.150 to 283.150) K. The VLE data were correlated by the Peng–Robinson equation of state with two different models, the van der Waals mixing rule, and the Huron–Vidal mixing rule involving the NRTL activity coefficient model. Good agreements were found between the calculated data and the experimental data. The maximum average absolute relative deviation of pressure (AARD p) was 0.48%, while the maximum average absolute deviation of composition (AAD y) was 0.0040. Meanwhile, zeotropic behavior can be found for the measured system in this study. The total combined standard uncertainties for temperature, pressure and composition measurements were ±5 mK, ±0.0005 MPa and ±0.005, respectively.  相似文献   

8.
Total vapour pressures, measured at the temperature 313.15 K, are reported for the ternary mixture (N,N-dimethylacetamide + ethanol + water), and for binary constituent (N,N-dimethylacetamide + ethanol). The present results are also compared with previously obtained data for (amide + ethanol) binary mixtures, where amide = N-methylformamide, N,N-dimethylformamide, N-methylacetamide, 2-pyrrolidinone, and N-methylpyrrolidinone. We found that excess Gibbs free energy of mixing for binary (amide + ethanol) mixtures varies roughly linearly with the molar volume of amide.  相似文献   

9.
Binary (vapour + liquid) equilibrium data were measured for the {carbon dioxide + pentafluoroethane (HFC-125)} system at temperatures from 313.15 K to 333.15 K and the {carbon dioxide + dodecafluoro-2-methylpentan-3-one (NOVEC™1230)} system at temperatures from 313.15 K to 343.15 K. These experiments were carried out with a circulating-type apparatus with on-line gas chromatography. The experimental data were correlated well by the Peng–Robinson equation of state using the Wong–Sandler mixing rules.  相似文献   

10.
This paper reports the results of a new experimental study on the (liquid + liquid) equilibrium of the system {ethyl stearate(1) + ethanol(2) + glycerol(3)} at atmospheric pressure and at T = (313.15 and 323.15) K. The equilibrium compositions were measured by gas chromatography. Ternary diagrams were obtained for each temperature and the equilibrium data were compared to the system in the presence of salt (NaCl) at T = 323.15 K. The experimentally determined (liquid + liquid) equilibrium data were satisfactorily correlated with NRTL and UNIQUAC equations. A comparative analysis was performed using the UNIFAC-LLE group contribution method. From the results presented herein good predictions were obtained for this ternary system.  相似文献   

11.
Vapour pressures of (tetrahydrofuran + 1,1,2,2-tetrachloroethane, or tetrachloroethene) at nine temperatures between T = 283.15 K and T = 323.15 K were measured by a static method. The reduction of the vapour pressures data to obtain activity coefficients and excess molar Gibbs energies was carried out by fitting the vapour pressure data to the Redlich–Kister polynomial according to Barker’s method. Excess molar volumes were also measured at T = 298.15 K. A comparative analysis about the thermodynamic behaviour of both systems is performed, in terms of hydrogen bonding and electron-donor–acceptor interactions, as well as the resonance effect in tetrachloroethene.  相似文献   

12.
Isothermal (vapour + liquid) equilibrium data were measured for the {1,1,1-trifluoroethane (HFC-143a) + isobutene} as an alternative refrigerant in the temperature range from (273.15 to 348.15) K at 15 K intervals. A circulating-type apparatus with on-line gas chromatography was used in these experiments. The experimental data were correlated well by Peng–Robinson equation of state using the Wong–Sandler mixing rules.  相似文献   

13.
The saturated vapor pressures of 1,1,1,2-tetrafluoroethane (R134a) and propane (R290), and the (vapor + liquid) equilibrium (VLE) data at (255.000, 265.000, 275.000, and 285.000) K for the (R134a + R290) system were measured by a recirculation apparatus with view windows. The uncertainty of the temperatures, pressures, and compositions are less than ±5 mK, ±0.0005 MPa, and ±0.005, respectively. The saturated vapor pressures data were correlated by a Wagner type equation and compared with the reference data. The binary VLE data were correlated with the Peng–Robinson equation of state (PR EoS) incorporating the Huron–Vidal (HV) mixing rule utilizing the nonrandom two-liquid (NRTL) activity coefficient model. For mixtures, the maximum average absolute relative deviation of pressure is 0.15%, while the maximum average absolute deviation of vapor phase mole fraction is 0.0045. Azeotropic behavior can be found for the (R134a + R290) system at measured temperatures.  相似文献   

14.
Phase equilibrium data for the binary systems {carbon dioxide (CO2) + dimethyl carbonate (DMC)} and {carbon dioxide (CO2) + diethyl carbonate (DEC)} were measured at temperatures of 273 K, 283 K and 293 K in the pressure range of 0.5 MPa to 4.0 MPa. The measurements were carried out in a cylindrical autoclave with a moveable piston and an observation window. The experimental data were correlated with the Peng–Robison (PR) equation of state (EOS) and the Peng–Robinson–Stryjek–Vera (PRSV) equation of state with van der Waals-1 or Panagiotopoulos–Reid mixing rules. The correlations produced reasonable values for the interaction parameters. The comparisons between calculation results and experimental data indicate that the PRSV equation of state coupled with the Panagiotopoulos–Reid mixing rule produced the better correlated results.  相似文献   

15.
The vapour pressures of binary (cyclohexanone + 1-chlorobutane, + 1,1,1-trichloroethane) mixtures were measured at the temperatures of (298.15, 308.15, and 318.15) K. The vapour pressures vs. liquid phase composition data have been used to calculate the excess molar Gibbs free energies GE of the investigated systems, using Barker’s method. Redlich–Kister, Wilson, UNIQUAC, and NRTL equations, taking into account the vapour phase imperfection in terms of the 2-nd virial coefficient, have represented the GE values. No significant difference between GE values obtained with these equations has been observed.  相似文献   

16.
In this study for two binary systems {1,2-dichloroethane (1) + toluene (2)} and {1,2- dichloroethane (1) + acetic acid (2)}, the isobaric (vapour + liquid) equilibrium (VLE) data have been measured at atmospheric pressure. An all-glass Fischer–Labodest type capable of handling pressures from (0.25 to 400) kPa and temperatures up to 523.15 K was used. Experimental uncertainties for pressure, temperature, and composition have been calculated for each binary system. The data were correlated by means of the NRTL, UNIQUAC, UNIFAC, and Wilson models with satisfactory results.  相似文献   

17.
Phase diagram and (liquid + liquid) equilibrium (LLE) results for {NaClO4 + polyethylene glycol 4000 (PEG 4000) + H2O} have been determined experimentally at T = (288.15, 298.15, and 308.15) K. The Chen-NRTL, modified Wilson and UNIQUAC models were used to correlate the values for the experimental tie-lines. The results show that the quality of fitting is better with the modified Wilson model.  相似文献   

18.
Phase diagram and (liquid + liquid) equilibrium (LLE) data for the (NaNO3 + polyethylene glycol 4000 (PEG 4000) + H2O) system have been determined experimentally at T = (288.15 and 308.15) K. The effects of temperature on the binodal curves and tie-lines have been studied and it was found that an increasing in temperature caused the expansion of two-phase region. The Chen-NRTL, modified Wilson and UNIQUAC models were used to correlate the experimental tie-line data. The results show that the quality of fitting is better with the UNIQUAC model.  相似文献   

19.
(Liquid + liquid) equilibrium (LLE) and binodal curve data were determined for the systems (water + phenol + tert-butanol) at T = 298.15 K, (water + phenol + 2-butanol) and (water + phenol + 1-butanol) at T = 298.15 K and T = 313.15 K by the combined techniques of densimetry and refractometry. Type I curve (for tert-butanol) and Type II curves (for 1- and 2-butanol) were found. The data were correlated with the NRTL model and the parameters estimated present root mean square deviations below 2% for the system with tert-butanol and lower than 0.8% for the other systems.  相似文献   

20.
Experimental isobaric (vapor + liquid + liquid) and (vapor + liquid) equilibrium data for the ternary system {water (1) + cyclohexane (2) + heptane (3)} and the quaternary system {water (1) + ethanol (2) + cyclohexane (3) + heptane (4)} were measured at 101.3 kPa. An all-glass, dynamic recirculating still equipped with an ultrasonic homogenizer was used to determine the VLLE. The results obtained show that the system does not present quaternary azeotropes. The point-by-point method by Wisniak for testing the thermodynamic consistency of isobaric measurements was used to test the equilibrium data.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号