Change of physical properties with the slurry-phase hydrocracking reaction of vacuum residue

Abstract The physical properties (density, kinematic viscosity, surface tension, and hydrogen solubility) and their correlations for a slurry-phase hydrocracking reaction were investigated with a vacuum residue (VR, as a feedstock) and hydrocracked products from VR conversion of 32.3%, 73.9% at different temperature and pressure conditions. As a result, the density, kinematic viscosity, and surface tension of the product decreased with converting VR, while the solubility of hydrogen increased. And the dependence of product properties on temperature showed to be similar to feedstock. Based on the measured data, the empirical correlations that can predict from VR to products were obtained with R-square of 0.9930 by modifying the existing correlations. From these properties change, it was confirmed that the hydrocracking temperature and the degree of the hydrocracking conversion of VR is the most dominant parameters to govern the change of physical properties. Finally, it was found that the mass transfer rate of hydrogen into oil is important because the hydrogen solubility (0.8 mol H2/kg feed or 0.16 wt.% on the feed weight at 160 bar, 410 ℃) on the liquid phase is much smaller than the chemical consumption of hydrogen (about 2∼3 wt.% on the feed weight) for near full conversion of VR.