Studying of Catalyst Deactivation in a Commercial Hydrocracking Process (ISOMAX)

Document Type : Research Paper


1 Catalysis Research Center, Research Institute of Petroleum Industry, Tehran, Iran

2 Faculty of Chemical and Natural Resources Engineering, Universiti Teknologi Malaysia, UTM Skudai, Johor Bahru, 81310 Malaysia


Catalyst deactivation is usually indispensable, although the rate at which it occurs varies greatly. At first, this article discusses the causes of deactivation in a commercial hydrocracking unit called Isomax. Then, a 5-lump kinetic model including catalyst decay function for hydrocracking of vacuum gas oil in a commercial plant is proposed. The model considers vacuum gas oil (VGO) having boiling point higher than 380oC (380+°C), diesel (260-380°C), kerosene (150-260°C), naphtha (IBP:150°C), and gas as products. By using selective catalyst decay function in the kinetic model, the effect of the catalyst deactivation on the yield of products over time is studied. The prediction of the model during 1.5 years is in good agreement with the actual                commercial data. The average absolute deviation (AAD%) of the model for the strategic products like naphtha, kerosene and diesel are about 1.784%, 1.983% and 1.971%, respectively. Also it is observed that the estimated parameters are consistent with the reported characteristics of amorphous catalysts. 


1] Valavarasu G., Bhaskar M. & Sairam B., “A Four Lump Kinetic Model for the Simulation of the Hydrocracking Process”, Petroleum Science and Technology, Vol. 23, No. 11-12, pp. 1323-1332, 2005.
[2] Ancheyta J., Lopez F. & Aguilar E., “5- Lump kinetic model for gas oil catalytic cracking”, Applied Catalysis A: General, Vol.177, No.2, pp. 227-235, 1999.     
[3] Astarita G. & Sandler, S. I., “Kinetics and thermodynamics lumping of multicomponent mixtures”, Elsevier: Amsterdam, pp. 111-129, 1991.
[4] Ancheyta J., Sanchez S. & Rodriguez M.A., “Kinetic modeling of hydrocracking of heavy oil fractions: A review”, Catalysis Today, Vol. 109, No. 1-4, pp. 76-92, 2005.
[5] Mosby F., Buttke R.D., Cox J.A. & Nikolaids C., “Process Characterization of Expanded-Bed Reactors in Series”, Chem. Eng. Sci., Vol. 41, No. 4, pp. 989-995, 1986.
[6] Yui S.M. & Sanford E.C.,“Mild hydrocracking of bitumen-drived coker and hydrocracker heavy gas oils: kinetic product yield and product properties”, Ind. Eng. Chem. Res., Vol. 28, pp. 319-320, 1989.
[7] Callejas M.A. & Martinez M.T., “Hydrocracking of a Maya Residue. Kineic and Product Yield Distributions”, Ind. Eng. Chem. Res., Vol. 38, pp. 98-105, 1999.
[8] Aoyagi K., McCaffrey W.C. & Gray M.R., “Kinetics of Hydrocracking and Hydrotreating of Coker and Oil
sands Gas Oils”
, Petroleum Science Technology, Vol. 21, No. 5, pp. 997-1015, 2003.
[9] Aboul-Gheit K., “Hydrocracking of Vacuum Gas Oil (VGO) for Fuels Production-Reaction Kinetics”, Erdol Erdgas Kohle, Vol. 105, No. 7-8, pp. 319-320, 1989.
[10] Almeida R.M. & Guirardello R., “Hydroconversion kinetics of Marlim vacuum residue”, Catalysis Today, Vol. 109, No. 1-4, pp. 104-111, 2005.
[11] Sanchez S., Rodriguez M.A. & Ancheyta J., “Kinetic model for moderate hydrocracking of heavy oils”, Ind. Eng. Chem. Res., Vol. 44, No. 25, pp. 9409-9413, 2005.
[12] Singh J., Kumar M.M., Saxena A.K. & Kumar S., “Reaction pathways and product yields in mild thermal cracking of vacuum residues: A multi-lump kinetic model”, Chem. Eng. J., Vol. 108, No. 3, pp. 239-248, 2005.
[13] Sadighi S., Arshad A. & Mohaddecy S.R., “6-Lump Kinetic Model for a Commercial Vacuum Gas Oil                  Hydrocracker”, International J. of Chemical Reactor Engineering, Vol. 8, Article A1, pp. 1-24, 2010.
[14] Moulijin J.A., Van Diepen A.E. & Kapteijn F., “Catalyst Deactivation; is it predictable? What to do?” Applied Catalysis A: general, Vol. 212, No. 1-2, pp. 3-16, 2001.
[15] Sertic-Bionda K., Gomzi Z. & Saric T., “Testing of Hydrosulfurization process in small trickle-bed reactor”, Chem. Eng. J., Vol. 106, No. 2, pp. 105-110, 2005.
[16] Klinken J. & Dongen R., “Catalyst dilution for improved performance of laboratory trickle-flow reactors”, Chem. Eng. Sci., Vol. 35, pp. 59-66, 1980.
[17] Bej S., Dabrel R., Gupta P., Mittal K., Sen S. & Kapoor V., “Studies on the performance of a microscale trickle bed reactor using different sized of diluents”, Energy & Fuel, Vol. 14, No. 3, pp. 701-705, 2000.
[18] Mederos F.S., Ancheyta J. & Chen J., “Review on criteria to ensure ideal behaviors in trickle-bed reactors”, Applied Catalysis A: General, Vol. 355, No. 1-2, pp. 1-19, 2009.
[19] Forissier M. & Bernard J.R., “Deactivation of Cracking Catalysts with Vacuum Gas Oil”, Studies in Surface Science and Catalysis, Vol. 68, pp. 359-366, 1991.
[20] Padmavathi G. & Chaudhuri K., “Modeling and Simulation of Commercial Naphtha Reformers”, The Can. J. of Chem. Eng., Vol. 75, No. 10, pp. 930-937, 1997.
[21] Hongjun Y., Chunming X., Jinsen G., Zhichang L. & Pinxiang Y., “Nine lumped kinetic models of FCC gasoline under the aromatization reaction conditions”, Catalysis Communication, Vol. 7, No. 8, pp. 554-558, 2006.
[22] Corella J., Morales F.G., Provost M. & Espinosa A., “Recent Advances in Chemical Engineering”, McGraw-Hill, pp. 192-210, 1988.
[23] Marafi A., Kam E. & Stanislaus A., “A kinetic study on non-catalytic reactions in hydroprocessing Boscan crude oil”, Fuel, Vol. 87, pp. 2131-2140, 2008.
[24] Scherzer J. & Gruia A.J., Hydrocracking Science and Technology, 1st Ed. Marcel Dekker, Inc., New York, 1996.
[25] Ali M.A., Tatsumi T. & Masuda T., “Development of heavy oil hydrocracking catalyst using amorphous silica-alumina and zeolites as catalyst supports”, Applied Catalysis A: General, Vol. 233, No. 1-2, pp. 77-90, 2002.