2012 Volume 55 Issue 6 Pages 363-370
Properties, chemical compositions and hydrotreatment reactivities of Mongolian crude oils and their distillation fractions were investigated and compared with those of Chinese and Middle East crudes. Mongolian crude oils were highly paraffinic with high pour point (> + 17 &drg;C) and low contents of sulfur (0.09-0.24 %), vanadium (<1 ppm) and carbon residue (<4.6 %), but contained large amounts of atmospheric residue (68-83 %). These features are very similar to Chinese Daqing crude. The middle and heavy distillates included large amounts of saturates (>85 %) and n-paraffins (35-50 %). The nitrogen contents were comparable with the other crude oils or distillation fractions examined. The distillates and atmospheric residues were hydrotreated, and the reactivities of hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) were compared. The HDS rates of low-sulfur feedstocks were much larger than those of high-sulfur feedstocks derived from the Middle East, whereas the HDN rates of the same boiling range fractions were similar. The relative HDS rates of the Mongolian feeds to the corresponding mixed Middle East feed were 6-14 for the middle distillates, 7-12 for the heavy distillates, and 5-6 for the atmospheric residues, and the relative HDN rates were 1-2<, 1-2.3 and 0.6-1, respectively. Polyaromatics were readily hydrogenated to monoaromatics but not to saturates due to the difficulty in further saturation.