Effect of catalyst condition on sedimentation and conversion in the ebullated bed vacuum residue H-Oil hydrocracking

摘要

This study highlights the importance of the condition of the catalytic system in the ebullated bed vacuum residue hydrocracker on the performance of the unit, proving that not only feedstock quality but also catalytic system quality are the single variables which have the biggest impact on residue hydrocracker performance. During processing the same vacuum residual oil in the LUKOIL Neftohim Burgas H-Oil ebullated bed hydrocracker a variation of conversion between 56.6 and 73.0% was observed. A higher sedimentation and the resulted decreased reaction severity were provoked by a higher vanadium content in the catalyst in the second reactor and a higher arsenic determinant in the whole catalytic system. The reduction of the second reactor catalyst vanadium content along with a decrease of the arsenic determinant in the whole catalytic system allowed recovering the 16.4% loss of conversion during processing the same feedstock. The increase of reaction temperature at constant liquid hourly space velocity (LHSV) increases aromaticity of the unconverted vacuum residual oil product, most probably due to dealkylation of the side alkyl groups attached to the aromatic cores. The raise of temperature also had an effect on the increase of asphaltene conversion, a fact that is not always observed during EBRHC of vacuum residual oils from different origin.