Co-coking of Hydrotreated Decant Oil/Coal Blends: Effect of Hydrotreatment Severity on the Yield Distribution and Quality of Distillate Fuels

Abstract

The co-coking of hydrotreated decant oil (DO)/coal blends using a large laboratory-scale delayed coker was studied. DO was hydrotreated at several levels of severity for use in the co-coking work. Increasing the hydrotreatment severity increased the levels of hydrodesulfurization (from 50.6 to 99.0%) and hydrodenitrogenation (from 7.7 to 88.7%). Hydrotreatment resulted in increased amounts of paraffins, saturated cyclics, alkylbenzenes, two-ring aromatics, and hydroaromatics but decreased the amount of three-ring and larger compounds in the liquid. The coke yield from delayed co-coking of hydrotreated DOs and coal blends was observed to be in the range of 15.9–24.4%. Distillate liquid obtained from delayed co-coking increased with hydrotreating severity of DOs (from 71.0 to 76.2%). The boiling point distribution of the distillate liquid products was determined using fractional vacuum distillation. The results from vacuum distillation reveal that the percentage of the liquid products corresponding to jet f...