| Popis: |
The ( p , ρ , T , x ) properties for (propane + n -butane + isobutane) ternary mixtures in the compressed liquid phase were measured by means of a metal-bellows variable volumometer over the temperature range from (280 to 440) K at pressures from (1 to 200) MPa. The mole fraction purities of the propane, n -butane, and isobutane used in the measurements were 0.9999, 0.9997, and 0.9999, respectively. The expanded uncertainties ( k = 2) in temperature, pressure, density, and composition measurements have been estimated to be less than ±3 mK; 1.4 kPa ( p ⩽ 7 MPa), 0.06% (7 MPa p ⩽ 50 MPa), 0.1% (50 MPa p ⩽ 150 MPa), and 0.2% ( p > 150 MPa); 0.09%; and 4.4 · 10 −4 , respectively. In the region above 100 MPa at T = (280 and 440) K, the uncertainty in density measurements increases from 0.09% to 0.13% and 0.22%, respectively. Comparisons of the available equation of state with the present measurements are reported. On the basis of the present results, the excess molar volume v m E of the mixtures was calculated and illustrated as a function of temperature and pressure. |
Full Text from ScienceDirect