Catalytic upgrading of a Uinta Basin bitumen over a commercial HDM catalyst

Uinta Basin bitumen was hydrotreated over a sulfidcd commercial Ni-Mo on alumina hydrodemetallation catalyst. The catalyst was on-stream continuously for over 1.000 hours. The extent of heteroatoni removal, residuum conversion and molecular weight reduction were investigated as a function of process variables. The fixed bed reactor was operated in the upflow mode to insure complete wetting of the catalyst and to maintain isothermal operation. The primary process variables studied were reactor temperature (620-685 K), weight hourly space velocity (0.24-1.38 h'1) and total reactor pressure (11.3- 16.7 MPa). The hydrogen/oil ratio was fixed in all experiments at 890 m'/in3 (=5000 scf H,/bbl). The catalyst deactivation rate was 0.18 °C/day. The effect of process variables on the" extent of denitrogenation. desulfurization, dcmetallation. residuum (>811 K) conversion and the product distribution and yields arc reported. The apparent activation energies for desulfurization and denitrogenation were 91 and 98 kJ/mol, respectively. A molecular weight reduction-model for hydrotreating over the HDM catalyst was proposed using four reactant lumps.