Densities and Viscosities of Binary Mixtures of Babassu Biodiesel plus Cotton Seed or Soybean Biodiesel at Different Temperatures

Density rho and viscosity eta were measured for binary mixtures of cotton seed + babassu and soybean + babassu biodiesel over the composition range at several temperatures of (293.15, 313.15, 333.15, 353.15, and 373.15) K and atmospheric pressure. The viscosity deviation (Delta eta) was determined and fitted by a Redlich-Kister type function in terms of mass fraction (w). The Joback's method combined with Lee-Kesler and Rackett equations were used to calculate the densities of the binary mixtures of cotton seed + babassu and soybean + babassu biodiesel. The experimental and estimated density values gave almost identical values with a relative differences of less than 0.21 %. The Ceriani's group contribution method was used to predict the viscosity, with a maximum relative deviation of 31 %.