Processes and catalysts for hydrocracking of heavy oil and residues

Abstract

Atmospheric or vacuum residue can be converted into valuable distillates using high reaction temperature, high hydrogen pressure and low contact time hydroprocessing units. Various residue hydrocracking processes are now commercially employed using fixed bed, moving bed or ebullated bed reactors. The choice of process type depends mainly on the amount of metals and asphaltens in the feed and on the level of conversion required. Various improvements have been introduced in the last decade to increase run length, conversion level, products qualities and stability of the residual fuel. These improvements include on stream catalyst replacement systems, swing reactors, improved feed distribution, guard bed materials limiting pressure drop, coke resistant catalysts, complex association of catalysts using particle size, activity and pore size grading. Further improvement of the resistance of catalysts to deactivation by coke and metal deposits and of the hydrodenitrogenation activity are two major challenges for the development of new residue hydrocracking catalysts and processes.