Empirical approach for predicting viscosities of liquid hydrocarbon systems: Defined compounds and coal liquids and fractions

A single-parameter empirical method, based on the effective carbon number concept, was developed to predict the viscosities of defined (alkanes, alkenes, aromatics, alicyclics, and hydrocarbon mixtures) and undefined (coal liquids and coal liquid fractions) hydrocarbon liquids at various temperatures and for pressures up to 700 bar. The only parameter required for estimating the viscosities of a hydrocarbon system is the effective carbon number, which can be obtained from a single liquid viscosity datum of the compound using one of two proposed correlations, that is, n-alkane correlation or aromatic correlation. Also, experimental data on the viscosities of laboratory-generated coal liquid oils were generated and used in the evaluation of the model. The new method, when tested on viscosity data of defined and undefined hydrocarbon liquid compounds at various pressures and temperatures, yielded an overall average absolute deviation (AAD) of 4.11% and 9.99%, respectively. The model was also found to compare favorably with other methods available in the literature.