CORRELATION OF VISCOSITY OF COAL LIQUIDS

Applicability of viscosity correlations for predicting viscosities of coal liquids was tested against experimental viscosity data of seven c oal liquids. The data considered in this work were at ambient pressure and moderate temperatures (294-360 K). The predicted viscosities were much lower than the experimental viscosities with an average absolute deviation of about 30% at best and 70% maximum; It appears that the a ssociation effects owing to hydrogen bonding in coal liquids are respo nsible for this deviation since the petroleum correlations far-viscosi ty predictions were developed for nonpolar, nonassociating fluids. A s imple correction is suggested which helps in predicting coal liquid vi scosities more accurately to within an average absolute deviation of 1 2%.