Kinetic model for hydrocracking of heavy oil in a CSTR involving short term catalyst deactivation Jeremías Martínez, Jorge Ancheyta ⇑ Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas 152, México D.F. 07730, Mexico highlights " An atmospheric residue (312 °C+) was hydroprocessed. " Experiments were performed in continuous stirred tank basket reactor. " A five-lump kinetic model to represent the hydrocracking reactions was used. " A time-dependant non-selective catalyst deactivation expression was considered. " Activation energies and kinetic constants for heavy oil hydrocracking are reported. graphical abstract article info Article history: Received 21 September 2011 Received in revised form 5 May 2012 Accepted 18 May 2012 Available online 15 June 2012 Keywords: Hydrocracking Heavy oil Kinetics Deactivation abstract A five-lump model previously reported in the literature was used for the kinetic modeling of an atmo- spheric residue (312 °C+) hydrocracking. The model has ten reaction rate coefficients, makes a distinction of different hydrocarbon groups based on boiling ranges, and includes the following lumps: unconverted vacuum residue (538 °C+), vacuum gas oil (VGO; 343–538 °C), middle distillates (204–343 °C), naphtha (IBP-204 °C), and gases. The kinetic study was carried out in a CSTBR at the following operating condi- tions: 380–420 °C, 100 kg f /cm 2 , 5000 std ft 3 H 2 /bbl of oil, and 0.5–1.25 ml feed /(ml cat h). Experiments were performed with a commercial size tetra lobular catalyst. The model also incorporates the effectiveness factor, and a time-dependant deactivation function for obtaining the intrinsic kinetic parameters. The hydrocracking of vacuum residue, VGO and middle distillates exhibited a higher selectivity toward the heavier lumps as temperature is increased. The predicted product composition is in good agreement with experimental values with an average absolute error less than 5%. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction The processing of heavy and extra-heavy crude oil feed with higher sulfur, nitrogen, asphaltenes, and metals content, has at- tracted more attention of refinery people than it has in the past to cover the demand of lighter products such as gasoline, kerosene, jet fuel and diesel. The conversion of this type of feed has been a challenging task that has led to development of new process con- figurations as well as new catalyst formulations. In parallel, kinetic studies have been conducted using different catalysts, feeds, reactors and reaction conditions. Most of the stud- ies have been carried out at steady-state conditions and only a few have been developed during the initial period of deactivation of the catalyst. Different kinetic approaches have been reported in the litera- ture for the hydrocracking of oil fractions (lumping approach, 0016-2361/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.fuel.2012.05.032 ⇑ Corresponding author. Tel.: +52 55 91758443; fax: +52 55 91758429. E-mail addresses: jmsalced@imp.mx, salcedo20@hotmail.com (J. Martínez), jancheyt@imp.mx (J. Ancheyta). Fuel 100 (2012) 193–199 Contents lists available at SciVerse ScienceDirect Fuel journal homepage: www.elsevier.com/locate/fuel