Can DIPPR Database be Used for an Estimation of the Speed of Sound? A Case Study of Liquid Hydrocarbons

Abstract

The paper analyses a possibility of utilising the information which is contained in DIPPR database for a calculation of the speed of sound, which is absent there. As an example, liquid hydrocarbons are considered: n-hexane, 1-hexene, cyclohexane, cyclohexene, benzene, and 1-hexanols, as well as representatives of n-alkanes with various hydrocarbon chain lengths. It is shown that the Brelvi-O'Connell correlation for the reduced bulk modulus, supplied with the correlations for the internal pressure at the normal boiling temperature, results in the values having accuracy comparable with other DIPPR data for the region below the boiling point bounded by the values of the reduced density around ρr ≈ 3.5. The source of errors originated from the Brelvi-O'Connell correlation for larger reduced densities is discussed.

Archives of Acoustics

“…( 3) that the gyration radius representing the molecular non-sphericity is in fact a control parameter for the isothermal compressibility of chained hydrocarbons due to its influence on their packing properties in the liquids bulk. Moreover, the proposed approach also removes the flaws in the Brelvi-O'Connell correlation characteristic for large reduced densities (Postnikov, 2016). Figure 2 demonstrates that the accuracy of the proposed approach is independent from the reduced densities.…”

“…However, this textual misprint did not appear in the programming code used for calculations. It is freely accessible now (Postnikov et al, 2018) and all numerical and graphical results of (Postnikov, 2016) are valid. Thus, the correct form of the modified Srivastava's correlation is Eq.…”

“…2, where one can see that the dash-dotted line representing the speed of sound in squalane calculated using the DIPPRprovided boiling temperature is practically parallelly shifted into the region of higher values with respect to experimental data (upward triangles) and the calculations reproducing them using the correction (5) (solid line). (Postnikov, 2016) for n-hexadecane and squalene; dash-dotted line -prediction of the described approach without the boiling point correction for squalene.…”

“…In particular, this equation exhibits a drastic decay for large reduced densities ρ r > 4.18. Such reduced densities are typical for the long-chained hydrocarbons, whose saturated liquid sound velocities have not been predicted in an accurate manner (Postnikov, 2016). Moreover, ξ = 1 leads to the unphysical negative isothermal compressibility in the critical point because Eq.…”

“…However, due to the lacking of pertinent experimental data, it does not include several important properties, such as the isothermal compressibility, isobaric thermal expansion coefficient, and speeds of sound of saturated liquids. In the previous study (Postnikov, 2016) it was demonstrated that tFhese properties can be estimated in a raw manner while implementing the available in the DIPPR data on vapour pressures, saturated liquid densities, and isobaric heat capacities. That approach was based on the Brelvi-O'Connel correlation for the isothermal compressibility (κ T ): µ 0 RT ρκ T = exp −0.42704 (ξρ r − 1) + 2.089 (ξρ r − 1)…”