Estimating the Kinematic Viscosity of Petroleum Fractions

Abstract

Kinematic viscosity correlation has been developed for liquid petroleum fractions at 37.78$\,^{\circ }\hbox {C}$ and $98.89\,^{\circ }\hbox {C}$ (100 and $210^{\circ }\hbox {F})$ standard temperatures using a large variety of experimental data. The only required inputs are the specific gravity and the average boiling point temperature. The accuracy of the correlation was compared with several other correlations available in the literature. The proposed correlations proved to be more accurate in predicting the viscosity at 37.78$\,^{\circ }\hbox {C}$ and $98.89\,^{\circ }\hbox {C}$ with average absolute deviations of 0.39 and $0.72\hbox { mm}^{2}/\hbox {s}$, respectively. Another objective was to develop a relation for the variation of viscosity with temperature to predict the viscosity of petroleum fraction at a certain temperature from the knowledge of the viscosity for the same liquid at two other temperatures. The newly developed correlation represents a wide array of temperatures from 20 $^{\circ }\hbox {C}$ to 150 $^{\circ }\hbox {C}$ and viscosities from 0.14$\hbox { mm}^{2}/\hbox {s}$ to 343.64$\hbox { mm}^{2}/\hbox {s}$. The results have been validated with experimental data consisting of 9558 data points, yielding an overall deviation of $0.248\hbox { mm}^{2}/\hbox {s}$ and $\hbox {R}^{2}$ of 0.998. In addition, new formulas were developed to interconvert the viscosity of petroleum fractions from one unit of measure to another based on finding the best fit for a set of experimental data from the literature with $R^{2}$ as high as 1.0 for many cases. Detailed analysis showed good agreement between the predicted values and the experimental data.