Measurements of density, speed of sound, and viscosity have been carried out on liquid standard reference materials for biofuels as a function of temperature at ambient pressure. The samples included anhydrous and hydrated bioethanol and two biodiesels from different feedstocks, soy and animal fat. The ethanol samples were measured from a maximum temperature of 60 °C to 5 °C (speed of sound) and to -10 °C (density and viscosity), respectively. The biodiesel samples were characterized from 100 °C (density and viscosity) and from 70 °C (speed of sound) to 10 °C (animal fat-based) and 5 °C (soy-based). Densities were measured with two vibrating-tube instruments of different accuracy. The speeds of sound were measured with a propagation-time method in an acoustic cell that was combined with one of the densimeters. Viscosities were measured with an open gravitational capillary viscometer and with a rotating concentric cylinder viscometer according to Stabinger. The measurement results are reported with detailed uncertainty analyses.
Citation: Energy and Fuels
Pub Type: Journals
Adjustment, Biodiesel, Bioethanol, Biofuels, Calibration, Capillary viscometer, Density, Reference materials, Rotating concentric cylinder viscometer, Speed of Sound, Stabinger viscometer, Vibrating-tube densimeter, Viscosity