Research Institute of Petroleum Industry (RIPI) Journal of Petroleum Science and Technology 2251-659X 1 1 2010 03 10 Studying of Catalyst Deactivation in a Commercial Hydrocracking Process (ISOMAX) 46 54 26 10.22078/jpst.2010.26 EN Mahdi Rashidzadeh Catalysis Research Center, Research Institute of Petroleum Industry, Tehran, Iran A. Ahmad Faculty of Chemical and Natural Resources Engineering, Universiti Teknologi Malaysia, UTM Skudai, Johor Bahru, 81310 Malaysia S. Sadighi Faculty of Chemical and Natural Resources Engineering, Universiti Teknologi Malaysia, UTM Skudai, Johor Bahru, 81310 Malaysia Journal Article 2011 03 10 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 380^oC (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 (<em>AAD%</em>) 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.  https://jpst.ripi.ir/article_26_4e732ced3463d06de0ca9a15b6153677.pdf