Hydrotreatment of Heavy Oil from Coal Liquefaction on Sulfided Ni-W Catalysts

Heavy oil (distillation temperature: 320-340 degrees C) derived from the direct coal liquefaction process using Shengli coal were hydrotreated using sulfided Ni-Mo/Al(2)O(3), Ni-W/Al(2)O(3), and Ni-W/SiO(2) catalysts respectively. The sulfided catalysts were characterized by BET, XRD, H(2)-TPR and NH(3)-TPD respectively. The evaluations of the hydrodenitrogenation (HDN) and hydrodearomatization (HDA) properties of heavy oil on the three catalysts were carried out at 400 degrees C and 5.0 MPa initial H(2) pressure. The W-based catalysts displayed better performances than Mo-based catalysts for the HDN and HDA reactions. Al(2)O(3) supported catalysts were found to have higher catalytic activities than on SiO(2) supported ones. The activities of sulfided catalysts were associated mainly with the nature of active sites, acidity, metal sulfide crystallite size and the amount of the reducible sulfur species of metal sulfide.