Acoustic and volumetric study of renewable oxygenated fuel additives at (298.15–323.15) K: Isomeric butanediols with ethylbutyrate

Abstract

Today biofuels are emerging in an exponentially manner in order to replace the fossil fuels. Biofuels are composed of several organic compounds containing wide variety of functional groups. The interactions existing among these compounds play a significant role in the efficiency of the biofuels. In this paper, the authors presented the new findings related to interactions existing in ethylbutyrate and α, ω-alkanediols in pure state as well as in their mixtures. Densities and speeds of sound at various temperatures (298.15–323.15) K and at ambient pressure 0.1 MPa have been measured for these mixtures. From experimental data, the excess properties such as excess molar volume, VmE, excess isentropic compressibility, κsE, excess molar isentropic compressibility, Ks,mE, excess speed of sound, uE, and excess isobaric thermal expansion, αpE, of the investigated mixtures were calculated. All the excess parameter values were fitted using the Redlich-Kister polynomial smoothing equation. The results were analysed in terms of molecular interactions. The partial molar volumes, V¯m,1 and V¯m,2, partial molar isentropic compressibilities, K¯s,m,1 and K¯s,m,2, excess partial molar volumes, V¯m,1E and V¯m,2E and excess partial molar isentropic compressibilities, K¯s,m,1E and K¯s,m,2E over whole composition range; the excess partial molar quantities of the components at infinite dilution have been calculated. The variations of these parameters with change in composition and temperature have been discussed in terms of intermolecular interactions prevailing in these mixtures. The VmE values for these mixtures were also calculated by using Prigogine–Flory–Patterson (PFP) theory and the results were compared with experimental findings.