Effect of temperature on the analysis of asphaltenes by the on-column filtration/redissolution method

• A new method to study the effect of temperature on asphaltene determination.
• Asphaltene contents are reduced as temperature is raised.
• Maltene contents increased as temperature is raised.
• Mass balances for virgin and processed n-heptane asphaltenes were carried out.
• Similar behavior was found for whole virgin or hydroprocessed samples.

The study of the effect of temperature on the analysis of asphaltenes by the on-column filtration/redissolution method is presented. The goal of this work is the prediction and early detection of asphaltene/solid precipitation at reservoir and refining conditions using simple, fast and reliable analytical techniques. A description of the new experimental methodology is introduced followed by the results of the analysis of n-heptane asphaltenes and virgin, vacuum residue (VR), visbroken and hydroprocessed petroleum samples in the temperature range 35–195 °C. Mass balances were effectively carried out and the presence of adsorbed species on the column surface was found. Consistent with gravimetrically separated asphaltenes, the new method showed that asphaltene contents are reduced as the temperature is raised whereas the maltene contents increased. Similar behavior was found for separated asphaltenes and whole virgin, VR or whole hydroprocessed samples. In general, it was observed that the amount of adsorbed species seems to increase with the temperature.