Coking due to possible cracking reactions in a Ni-Mo/Al2O3 hydrotreatment c
atalyst was studied independently of the sulfur present. A model has been t
ested to predict the carbon concentration profiles obtained during the reac
tion. Simulated and experimental results are compared and several kinetic e
quations are tested in the simulation. The model predicts well the average
carbon level in the catalytic bed and gives a slightly higher maximum carbo
n concentration. (C) 2001 Elsevier Science B.V. All rights reserved.