Sar-Ad Method to Characterize Vacuum Residues from Different Origins As a Tool to Investigate the Performance of a Commercial Ebullated Bed Vacuum Residue Hydrocracker

The eight-fraction SAR-ADTM characterization method was employed for the first time to investigate the impact and evolution of these fractions during hydrocracking of different vacuum residues. SAR-AD data was used to establish a model for the quantitative relationship between the various fractions and the performance of a commercial ebullated bed vacuum residue hydrocracker. The conversion level in the commercial ebullated bed vacuum residue hydrocracker operating at constant sediment formation rate was found to negatively correlate with the SAR-AD Resins and asphaltenes, and positively on the content of sulfur in the vacuum residue feed. The content of Saturates, Aro 1, Aro 2, and Aro 3 fractions in the hydrocracked vacuum residue was found to depend on their contents in the feed and the conversion level. The Resin, CyC6 asphaltenes, and CH2Cl2 asphaltene fractions were found to depend only on their content in the ebullated bed vacuum residue feed. Based on the use of different model compounds, it was shown that the SAR-AD fractions contain the following molecular structures: Saturates: linear and highly cyclic alkanes; Aro 1: molecules with a single aromatic ring; Aro 2: mostly 2 and 3-ring fused aromatic molecules, the pericondensed 4-ring molecule pyrene, and molecules with 3-5 rings that are not fused; Aro 3: 4 membered linear and catacondensed aromatics, larger pericondensed aromatics, and large polycyclic aromatic hydrocarbons with a wide range of conjugation and connectivity (island or archipelago) including large molecules with molecular weights in the range of asphaltenes; Resins: mostly fused aromatic ring systems containing polar functional groups, and metallated polar Vanadium oxide porphyrin compounds;Â Asphaltenes: both island- and archipelago-type of structures with a broad range of molecular weight variation, aromaticity and heteroatom contents.