Thermophysical and excess properties of diesel + biodiesel with octanol isomers at different temperatures

Abstract

Thermophysical properties of biodiesel mixtures are essential to design the injection system components and evaluate the spray characteristic through the combustion chamber as well as understand the type of interactions present in the mixture. In this work, densities, viscosities, and refractive indices of pseudo-ternary mixtures of diesel + biodiesel + 1-octanol, 2-octanol, and 2-ethyl-1-hexanol have been measured from (288.15 to 338.15) K at 0.1 MPa. In addition, properties of the pseudo-binary mixtures of biodiesel + octanol isomers are reported at the same temperature conditions and over the entire range of compositions. The experimental results for the pure components show agreement with data reported in literature within an average absolute percentage deviation of (0.019, 0.742, and 0.155) % for density, viscosity, and refractive index, respectively. Densities and viscosities of the mixtures have been compared with the limits set by the diesel fuel standard (EN 590). This work presents mixtures that meet these limits and can be considered as alternative fuels to conventional diesel. Excess molar volumes, viscosity deviations, and refractive index deviations are calculated from experimental data and represented through the Redlich-Kister equation. The McAllister and Nava-Ríos et al. equations have been used to correlate the kinematic viscosities of the pseudo binary and ternary mixtures as a function of the molar composition.