Density, Viscosity, Speed of Sound, Bulk Modulus, Surface Tension, and Flash Point of Binary Mixtures of n-Dodecane with 2,2,4,6,6-Pentamethylheptane or 2,2,4,4,6,8,8-Heptamethylnonane

Abstract

In this work, the physical properties of binary mixtures of n-dodecane with 2,2,4,6,6-pentamethylheptane or 2,2,4,4,6,8,8-heptamethylnonane were measured and compared to properties of four hydrotreated renewable jet (HRJ) and hydrotreated renewable diesel (HRD) fuels. Density and viscosity were measured at temperatures ranging from (293.15 to 393.15) K, and the speed of sound was measured at temperatures ranging from (293.15 to 333.15) K. For the mixtures, the speed of sound at 293.15 K decreased (1297.6 to 1285.7) m·s–1 as the mole fraction of 2,2,4,4,6,8,8-heptamethylnonane increased and decreased (1297.6 to 1203.6) m·s–1 as the mole fraction of 2,2,4,6,6-pentamethylheptane increased. The bulk modulus was calculated from density and speed of sound data. Flash points for the mixtures ranged from (318 to 367) K, and surface tension values ranged from (21.8 to 25.3) mN·m–1. When comparing to alternative fuels, two-component mixtures could be found to match the density and viscosity of HRJs and HRDs. The mixtures matched the speed of sound, bulk modulus, surface tension, and flash point of some of these hydrotreated fuels. These data suggest that binary mixtures of n-dodecane with branched alkanes may be suitable surrogates for renewable fuels.