Detailed kinetic modelling of vacuum gas oil hydrocracking using bifunctional catalyst: A distribution approach
Résumé
A kinetic model for hydrocracking a real vacuum gas oil at 120 bar and
400 degrees C in a semi-batch reactor has been constructed based on
analysis results from two dimensional gas chromatography (GC x GC). The
model has 217 pseudo-component lumps classified by carbon number and
hydrocarbon family. Hydrogenation and cracking reactions are included
separately and product distributions are generated using a probabilistic
approach. Mass transfer resistances and vapour-liquid equilibrium are
also accounted for. 17 parameters were estimated and the resulting model
is able to fit the experimental data quite well. It was found that it
is important to consider the average molecular structure within each
lump. To this end, the non-reactivity of components within the paraffin
lumps is taken into account in the probability matrix. A parameter has
been included for the number of branches removed from the aromatics and
naphthenes and it was also necessary to separate the aromatics and
naphthenes into mono-ringed and multi-ringed lumps. This many lumped
model allows us to approach the results found in studies with model
molecules. (C) 2015 Elsevier B.V. All rights reserved.