Abstract: The stability of three ASP-HD system including Asphaltene-1-methylnaphthalene, Asphaltene-tetralin and Asphaltene-decalin with the mass ratio of 1:10 was investigated by Turbiscan stability analyzer. The interaction between hydrogen donor molecules and asphaltene unit was simulated and calculated by Gaussian and Multiwfn, and then NCI analysis was performed. The result shows that the stability sequence of the three ASP-HD system was as follows: asphaltene-(1-methylnaphthalene) system, asphaltene-tetralin system and asphaltene-decalin system. The main reason for the stability difference of the three systems is that the interaction between hydrogen donor molecules and asphaltene unit is different. T-stacking interaction strength between the hydrogen donor molecules and the asphaltene unit is decreased in the following sequences: (1-methylnaphthalene)-asphaltene unit, tetralin-asphaltene unit, decalin-asphaltene unit. Qualitative analysis showes that the T-stacking interaction between hydrogen donor molecules and asphaltene unit is mainly van der Waals force, but the proportion of hydrogen bonds in the weak interaction is different.

Key words: Asphaltene-hydrogen donor system, Stability, Interaction, Gaussian, NCI analysis