Accurate viscosity data are crucial in numerous engineering and science disciplines, for example in the oil industry where mixtures of hydrocarbons are produced and/or processes under conditions of high temperatures and pressures. Currently, there is a lack of experimental data for the viscosity of liquid hydrocarbons at temperatures above approximately 473 K. Therefore, in this work, the viscosities of liquid hexadecane and squalane, which are considered representative hydrocarbons, have been measured at temperatures between (323 and 723) K and at pressures up to 4 MPa. The experiments were carried out using a dual-capillary viscometer that consisted of two capillaries in series operated at almost the same pressure. One capillary was maintained at a reference temperature (e.g. 298.15 K) at which the viscosity is known, while the other capillary was at the test temperature. The ratio of the pressure drops across the two capillaries was used together with the density ratio to determine the ratio of viscosites1. The density ratios for hexadecane was calculated using the equation of state recently developed by Romeo and Lemmon2, while for squalane, at temperatures below 525 K, this property was obtained from the correlation of experimental data developed by Schmidt et al.3 At temperature above 525 K, the density ratios of squalane were estimated through the principle of corresponding states using decane as the reference fluid. Literature viscosities at the reference temperature were used together with the experimental viscosity ratios to determine absolute viscosities. These absolute viscosities were obtained with an expanded relative uncertainty at 95 % confidence that was estimated to be about 3 %. The results were found to agree well with existing literature data in the range of their validity.
1. Z. Liu, J.P.M. Trusler and Q. Bi J. Chem. Eng. Data 2015, 60, 2363−2370
2. Romeo, R. and Lemmon, E.W. to be submitted, 2017.
3. K.A.G. Schmidt, D. Pagnutti, M.D. Curran, A. Singh, J.P. Martin Trusler, G.C. Maitland, and M. McBride-Wright, J. Chem. Eng. Data 2015, 60, 137−150
