Advantages of Mild Hydrocracking FCC Feed—A Pilot Plant Study

Abstract

In view of increasingly stringent environmental regulations with respect to SOx and particulate emissions, the allowable sulphur and nitrogen levels in diesel and gasoline are reducing all over the world. Fluid catalytic cracking (FCC) unit is a major source of fuels produced from a refinery. Any attempt to reduce sulphur and nitrogen content of distillates produced from FCC unit will greatly improve the quality of fuels. In the present work, pilot plant studies were conducted to evaluate the options of hydrotreating and mild hydrocracking (MHC) of FCC feedstock. Experiments were conducted on commercially available catalyst samples using high nitrogenous vacuum gas oil (VGO) as feedstock. MAT experiments were also conducted to compare the conversions and yields of untreated, hydrotreated, and MHC VGO at constant operating conditions. Pilot plant data showed that MHC of VGO would produce additional fuels to the extent of 15% under moderate operating conditions besides improving the quality of FCC feedstock. The mild hydrocracked VGO as feed was found to increase FCC conversion by 2 wt%, increase fuels by 2.5 wt%, reduce residue by 2.8 wt% compared to untreated vacuum gas oil.