An approach to model the hydrodesulfurization (HDS) and hydrodemetallization (HDNi and HDV) of a heavy crude oil (21 degrees API and 3.51 wt% sulfur) was developed. By using data obtained from an experimental bench-scale reactor at different reaction conditions of LHSV (0.33-1.5 h(-1)), temperature (380-420 degrees C) and pressure (6.9 MPa) keeping constant the hydrogen-to-oil ratio at 5000 std ft(3)/bbl oil, the kinetic model parameters were derived. The isothermal operation of the reactor was verified. The reactor was modeled as one-dimensional heterogeneous. Although several assumptions have been made, the simulated results agree well with experimental information. The developed model is able to simulate the HDS and HDM reactions and to perform predictions at different pressure of that used to determine the parameters. (c) 2012 Elsevier Ltd. All rights reserved.