Simultaneous Measurement of Dynamic Viscosity and Density of n-Alkanes at High Pressures

Abstract

New experimental data of the dynamic viscosity and density of pentane, octane, nonane, decane, and dodecane are reported. The experimental method was validated by determining and comparing the dynamic viscosity and the density of decane with the data previously published in the international literature, obtaining a maximum deviation of 12 μPa·s and 0.35 kg·m–3 for dynamic viscosity and density, respectively. The measurements were performed simultaneously using a capillary tube viscometer and a vibrating tube densimeter at temperatures between 293 and 353 K and pressures up to 30 MPa. The estimated relative combined expanded uncertainties (k = 2), considering the impurities of the compounds (including content of water), are 0.9% for the dynamic viscosity and 0.13% for the density over the entire measurement range. The viscosity data were successfully correlated as a function of pressure and temperature with an empirical model proposed in this study. Also, the experimental density data were successfully modeled with an equation previously published in the international literature. Besides, the experimental density data were used to obtain the isothermal compressibilities and isobaric thermal expansivities.

Twenty Years of Experimental Determinations of Thermophysical Properties with High Accuracy: Thermodynamics Laboratory, ESIQIE-IPN, México

“…Pressure transducers and platinum probes were calibrated, and the combined uncertainties were estimated to be u c (P) = 0.002 MPa and u c (T) = 0.009 K. For details about the method and procedure used, the reader is referred to the previous works. 29,30 Measurements of dissociation conditions of gas hydrates were performed in an experimental apparatus designed and built in house, consisting of a synthetic nonvisual apparatus. The equilibrium cell is "blind" and made of stainless steel.…”

“…Viscosity data of polar and nonpolar fluids are of great importance for several technological applications and in chemical engineering mainly where the movement of the fluids controls the process. 29,30 In the literature, several experimental methods Gas Hydrate Dissociation Conditions. In the oil industry, the formation of gas hydrates is considered as a potential to cause operational problems.…”

“…Viscosity data of polar and nonpolar fluids are of great importance for several technological applications and in chemical engineering mainly where the movement of the fluids controls the process. , In the literature, several experimental methods for measuring the viscosity of liquids at high pressures are presented, in which the capillary flow technique stands out. Recently, a new experimental system has been developed to determine simultaneously the viscosity and density of pure liquids and liquid mixtures up to 70 MPa and 423 K, according to the modified Hagen–Poiseuille equation.…”

Densities and Viscosities of Binary and Ternary Solutions of Triethylenetetramine, 2-Amino-2-methyl-1-propanol, and Water for Carbon Dioxide Capture

“…25,27,28 However, the uncertainty of viscosity data can be increased by increasing the system temperature. 30,31 Taking into account the contributions mentioned, the combined expanded uncertainties with 0.95 level of confidence (k ≈ 2) in the density and viscosity are estimated to be U c (ρ) = 0.0007 g•cm −3 and U c (η) = 0.01 mPa•s, respectively.…”

“…To calculate the uncertainties for experimental data, different factors such as density, viscosity, temperature, and pressure of the system, the accuracy of the balance and the viscometer–densimeter apparatus, and the impurity of the tested samples were implemented. For compounds with purity above 99%, studies in the literature have shown that the effect of the impurity in the uncertainty of density data is ignored. − However, the relative uncertainty in density data for samples with a purity of 99% or less increases by 0.1%. , The uncertainty in viscosity data is most affected by the amount of water added to the sample. ,, However, the uncertainty of viscosity data can be increased by increasing the system temperature. , Taking into account the contributions mentioned, the combined expanded uncertainties with 0.95 level of confidence ( k ≈ 2) in the density and viscosity are estimated to be U c (ρ) = 0.0007 g·cm –3 and U c (η) = 0.01 mPa·s, respectively.…”