Thermophysical Properties of Biofuel Components Furfural or Furfuryl Alcohol with Alcohols: Experimental and Thermodynamic Modeling

Abstract

Thermodynamic/transport properties of mixtures containing furfural or furfuryl alcohol with alcohols are crucial for a fundamental understanding and for various engineering and industrial applications. Therefore, the density (ρ), speed of sound (c), and refractive index (nD) of furfural with 1-propanol or 2-propanol and furfuryl alcohol with 1-propanol or 2-propanol at T = (293.15 to 323.15) K and atmospheric pressure were measured. ρ and c were measured using a digital vibrating U-tube densimeter (Anton Paar DSA 5000 M), and the refractive index was measured with a refractometer (Abbemat 300, Anton Paar). From the experimental data, the isentropic compressibility (κs), intermolecular free length (Lf), specific acoustic impedance (Ζ), relative association (RA), relaxation strength (r), and Rao’s molar sound function (R) were calculated. Excess/deviation properties of all of the studied mixtures were calculated and fitted to the Redlich–Kister polynomial equation. Furthermore, the Perturbed Chain Statistical Associating Fluid Theory (PC-SAFT) equation of state was applied to calculate the density of the binary systems and compare with the experimental data. This work presents experimental thermophysical property data and provides insight into the nature and strength of intermolecular interactions and structural changes upon mixing.