Sediment Formation in Residue Hydroconversion Processes and Its Correlation to Asphaltene Behavior

摘要

In this work, the link between asphaltene stability and sediment formation in hydroprocessing of residua is evaluated using two recently developed techniques for asphaltene characterization (Asphaltene Solubility Profile and Solubility Fractions). Several feeds as well as products coming from commercial units and pilot plants are examined in terms of asphaltene content and asphaltene stability. The results obtained confirm the relationship between stability, structural asphaltene characteristics, and sediment formation in products. It was found that stability, asphaltene content, and nature of the feeds are key factors in sediment formation. Two sets of correlations were found: those that correlate sediment with product characteristics and those that correlate sediment with feed characteristics and operational conditions. Both sets of correlations include asphaltene solubility characteristics and content as key parameters. These findings indicate that proper asphaltene characterization of feeds can help to reduce fouling in operating units by facilitating feed selection and adjustment of operational conditions. Additionally, it has been shown that the two proposed methods can be used to monitor sediment formation during hydroconversion as well as to evaluate solvents for blending in a fast and simple way compatible with a refinery lab environment.