The infinite diffusion coefficients of benzene, toluene, naphthalene, pyridine and p-nitroaniline in ethanol were measured by Taylor dispersion technique under 313—473 K and 0—16 MPa.The measurement accuracy of the ...The infinite diffusion coefficients of benzene, toluene, naphthalene, pyridine and p-nitroaniline in ethanol were measured by Taylor dispersion technique under 313—473 K and 0—16 MPa.The measurement accuracy of the established apparatus was first checked.The measured diffusion coefficient of the five organic solutes in ethanol did not change with pressure at low temperature, but it was significantly reduced with pressure increase when the temperature is higher than 373 K.Of the correlations available for polar solvents,the modified Wilke-Chang equation,the Yang-Zhang equation as well as the He-Yu equation were used to calculate the infinite diffusion coefficient. At low temperature, the three equations all agreed well with experimental results for both polar and non-polar solutes.However, the prediction accuracy was decreased sharply when the temperature was higher than 373 K, where the association factor of the solvent was varied with temperature as well as pressure.展开更多
A new model was proposed to calculate the viscosity of fluids under the pressure ranging from 0.1 to 110MPa by improving the Tait equation, in which the viscosity μ of liquids was linked with activation volume V. The...A new model was proposed to calculate the viscosity of fluids under the pressure ranging from 0.1 to 110MPa by improving the Tait equation, in which the viscosity μ of liquids was linked with activation volume V. The model with two adjustable parameters a and fl was applied in calculating viscosities for alkane, aromatic and alcohol family at high pressure. Results show that calculated values of viscosity are in good agreement with the experimental ones, and the average relative deviations for alkanes, aromatics and alcohols are 0.56%, 0.31% and 0.66%, respectively. Besides, the errors correlated by the model proposed in this paper were equivalent to the ones from the pure empirical Tait equation, and obviously superior to those from Eyring equation.展开更多
High-pressure phase behavior of supercritical (SC) CO2+ethanol system was investigated at 333.2 K,348.2K, 353.2K, 368.2K, 413.2K and 453.2K and pressure from 2.0MPa to 14.3MPa. The measurement was carried out in a cy...High-pressure phase behavior of supercritical (SC) CO2+ethanol system was investigated at 333.2 K,348.2K, 353.2K, 368.2K, 413.2K and 453.2K and pressure from 2.0MPa to 14.3MPa. The measurement was carried out in a cylindrical autoclave with a moveable piston and a window for adjustment and observation of phase equilibria at given T and p. The samples were taken from two coexisting phases and were analyzed to obtain their compositions. It is shown that the solubility of SC CO2 in ethanol increases drastically with pressures at the given temperature, but the content of ethanol in CO2-rich phase increase faintly.展开更多
文摘The infinite diffusion coefficients of benzene, toluene, naphthalene, pyridine and p-nitroaniline in ethanol were measured by Taylor dispersion technique under 313—473 K and 0—16 MPa.The measurement accuracy of the established apparatus was first checked.The measured diffusion coefficient of the five organic solutes in ethanol did not change with pressure at low temperature, but it was significantly reduced with pressure increase when the temperature is higher than 373 K.Of the correlations available for polar solvents,the modified Wilke-Chang equation,the Yang-Zhang equation as well as the He-Yu equation were used to calculate the infinite diffusion coefficient. At low temperature, the three equations all agreed well with experimental results for both polar and non-polar solutes.However, the prediction accuracy was decreased sharply when the temperature was higher than 373 K, where the association factor of the solvent was varied with temperature as well as pressure.
基金Supported by the National Natural Science Foundation of China （No.20476083） and the Natural Science Foundation of Hubei Province （No.2002AB065）.
文摘A new model was proposed to calculate the viscosity of fluids under the pressure ranging from 0.1 to 110MPa by improving the Tait equation, in which the viscosity μ of liquids was linked with activation volume V. The model with two adjustable parameters a and fl was applied in calculating viscosities for alkane, aromatic and alcohol family at high pressure. Results show that calculated values of viscosity are in good agreement with the experimental ones, and the average relative deviations for alkanes, aromatics and alcohols are 0.56%, 0.31% and 0.66%, respectively. Besides, the errors correlated by the model proposed in this paper were equivalent to the ones from the pure empirical Tait equation, and obviously superior to those from Eyring equation.
文摘High-pressure phase behavior of supercritical (SC) CO2+ethanol system was investigated at 333.2 K,348.2K, 353.2K, 368.2K, 413.2K and 453.2K and pressure from 2.0MPa to 14.3MPa. The measurement was carried out in a cylindrical autoclave with a moveable piston and a window for adjustment and observation of phase equilibria at given T and p. The samples were taken from two coexisting phases and were analyzed to obtain their compositions. It is shown that the solubility of SC CO2 in ethanol increases drastically with pressures at the given temperature, but the content of ethanol in CO2-rich phase increase faintly.
