Hydroprocessing of vacuum residues: Asphaltene characterization and solvent extraction of spent slurry catalysts and the relationships with catalyst deactivation
Slurry phase hydroprocessing showed that 2.5 & 5 wt% Mo catalysts showed signs of deactivation after four- to five-hours of reaction time. Solvent extraction of spent slurry catalysts showed that more asphaltenes deposited on the 2.5 wt% deactivated catalysts than on the 5 wt% analog. Fractions removed by solvent extractions are related to coke formation and might be responsible for catalyst deactivation. Pyridine organic extract was more aromatic and had a higher concentration of the highest solubility parameter asphaltenes.