The Distribution of Ni and V in Resin and Asphaltene Subfractions and Its Variation During Thermal Processes

<div><p>Ni and V deactivate catalysts and promote coking during heavy oil upgrading. Distribution of metals and metalloporphyrins, and its variation in thermal process, would benefit the more efficient upgrading. Majority of metals concentrate in resins and asphaltenes. To thoroughly study the metals distribution in these fractions, both were subdivided. It is indicated that the interactions between metalloporphyrins and asphaltenes play a significant role in metals distribution. Variation of metals distribution showed that the trend metals concentrated into heavier subfractions and was enhanced by thermal treatment and inhibited by hydrogen sources. Synergism was observed between hydrogen and hydrogen donor for the inhibition.</p></div

Compatibility of Heavy Blends Evaluated by Fouling and Its Relationship With Colloidal Stability

<div><p>To predict oil compatibility is crucial because incompatibility could cause severe deposition and fouling problems. Therefore, compatibility of heavy oils and blends in different ratios were evaluated by fouling at heat transfer conditions. Thermal resistance and fouling rates were obtained on a fouling loop. Effect of colloidal stability based on asphaltene precipitation and SARA composition on fouling was also discussed. Results showed that different variations of fouling rate versus blending ratio were observed for these blending systems. For oils whose viscosities approach at heat conditions, the lower colloidal stability of blends is the higher fouling rate is. However, for oils with greatly different viscosities, inconsistency was observed between compatibility by the two indicators, which is attributed to remarkable change of flow condition. This indicates that both colloidal stability and flow condition play key roles in fouling. Oil compatibility at heat transfer condition is favored being predicted by fouling instead of correlating with the colloidal stability.</p></div