Density, Excess Volumes, and Partial Volumes of Binary Mixtures of Soybean Biodiesel + Diesel and Soybean Biodiesel + n-Hexadecane at Different Temperatures and Atmospheric Pressure

摘要

Densities,ρ, of binary mixtures of diesel + soybean biodiesel and n-hexadecane + soybean biodiesel have been measured as a function of the composition at different temperatures (293.15, 313.15, 333.15, 353.15, and 373.15) K and atmospheric pressure, over the entire composition range, using an Anton Paar SVM 3000 oscillating U-tube densimeter. The excess molar volume, V~E, and excess partial molar volume, V~E, of the binary mixtures were calculated from the density data. These data have been correlated using the Redlich-Kister type function in terms of mass fraction (w), with a maximum standard deviation of 0.152 cm~3·mol~(-1). The excess volumes are positive for the soybean biodiesel + diesel system. The values of the excess volume for the system soybean biodiesel + n-hexadecane are also positive and an inversion of sign in V~E is observed at higher molar fractions of soybean biodiesel (around x1 = 0.60 to 0.80). The excess partial volume at infinite dilution has been also calculated.