Catalytic hydrocracking of a Mexican heavy oil on a MoS2/Al2O3 catalyst: I. Study of the transformation of isolated saturates fraction obtained from SARA analysis

A heavy crude oil was separated into its SARA fractions. Saturates fraction was isolated and tested on a hydrocrking process using Mo/gamma-Al2O3 catalyst at 8.27 H-2 MPa and 380, 390 and 400 degrees C. The aim of this work is to stablish the scheme of reaction based on saturates fraction chemical properties, which help to clarify yields of naphtha, kerosene, gasoil, atmospheric residue and vacuum residue distillate cuts when a heavy oil is processed. The saturate fraction and the samples after reaction were characterized by ASTM standard methods D3279, D2007, D7169 (TBP curve), gas chromatography and mass spectroscopy. Several kinetics models were fitted, and the better kinetic model shows as main features: The saturates SARA fraction does not produce another SARA fraction or coke, vacuum residue and atmospheric residue are the main reactive cuts, besides they are not gas producers. Gas oil is a primary and intermediary product. Kerosene and naphtha are formed from gas oil. Kerosene is intermediary product and producer of gas due to its high concentration of i-alkenes.