Viscosity and Density Measurements on Liquid n-Heptadecane at High Pressures

This article reports novel measurements of the viscosity, eta, of liquid n-heptadecane at pressures up to 70 MPa, along six isotherms between 303 and 358 K. The experiments were carried out using a vibrating wire viscometer operated in the forced mode. The 303 and 313 K isotherms have a restricted range of pressures to avoid eventual solidification. The present measurements have an uncertainty less than U(eta) = 0.015. eta with a confidence level of 0.95. Complementary measurements of the density, rho, were performed with the same ranges of temperature and pressure, using a DMA HP Anton Paar U-tube densimeter, with a DMA 5000 instrument as a reading unit. The overall maximum uncertainty is U(rho) = 0.002. rho with a confidence level of 0.95. The article provides a correlation of the viscosity of compressed liquid n-heptadecane with the molar volume, constructed by means of a scheme based on a modified hard-sphere theory, which describes the experimental data within ca. 1%. A program is provided in the Supporting Information to promptly perform interpolation of the viscosity as a function of temperature and pressure. The isothermal compressibility and the isobaric thermal expansivity were calculated from the density. Viscosity-pressure coefficients have also been determined from the viscosity.