Measuring the Density, Viscosity, Surface Tension, and Refractive Index of Binary Mixtures of Cetane with Solketal, a Novel Fuel Additive

Abstract

As a consequence of the surplus of glycerol generated from the development of the biodiesel industry, making valuable products from it has been an ongoing subject for the past few years. In previous work, several products have been synthesized from glycerol, such as solketal, with a proven value as an additive to different types of fuels. On the other hand, nhexadecane is frequently used as a reference compound to model diesel properties. This work presents a thorough experimental study on the determination of different volumetric properties of binary mixtures containing n-hexadecane and solketal, namely, density, viscosity, surface tension, refractive index, and the excess properties and deviations thereof derived. These properties were measured over the entire range of compositions in increments of the molar fraction of the components of 0.1 in the range from 293.15 or 298.15 to 323.15 K. Finally, correlation of the Redlich−Kister equation to the experimental excess properties and deviations was made, allowing for the retrieval of the corresponding fitting parameters.

Density, viscosity, surface tension, and excess properties of DSO and gas condensate mixtures

“…9 is reduction in the difference between positive and negative viscosity deviation values by increasing in temperature. The same behavior was observed by Esteban et al for a binary mixture of solketal and n-hexadecane [28]. The S-shape behavior was also observed for viscosity deviations in a binary mixture, where a downward peak appeared in early part of the chart and an upward one in late part or vice versa.…”

“…9, it can be observed that viscosity deviations of mixture represent a W-shape trend for all mole fractions and temperatures in which the negative parts appeared at This may be due to the disruption of molecular order of the dilute component which results in the random separation of molecules of the dilute component within the more concentrated one. The positive viscosity deviation, on the other hand, may be due to intermolecular Van der Waals attraction force as well as interactions between permanent and induced dipoles [28]. The other remarkable point that can be concluded from Fig.…”

“…As can be seen, the excess molar volumes are positive for all molar ranges. This phenomenon is likely arising from the interaction effects occurred by mixing condensate and DSO which results in breaking of chemical bonds and increase the total volume after mixing, leading to excess molar volume greater than zero [28]. While the negative excess molar volume may suggest strong interactions such as hydrogen bond between molecules of a mixture [27], the positive value for excess molar volume was also observed by AlTuwaim et al for different binary mixtures of N,Ndimethylformamide in combination with 1-pentanol, 1-hexanol, and 1-heptanol separately [31].…”

“…The height of curves of excess molar volume illustrated in Fig. 8 increases by increasing temperature that can be attributed to bond breaking and volume expansion by temperature [27][28][29][34][35][36].…”

“…Deviation of excess Gibbs free energy (DG E ) is considered as another important mixture property and can be determined by Eq. (12) for a binary mixture [28]:…”