Stability of Petroleum Asphaltene Fractions in Model Hydrocarbon Systems

• Published in: Chemistry and technology of fuels and oils 2014-03, Vol.50 (1), p.28-38
• Main Authors: Tumanyan, B. P., Petrukhina, N. N., Allogulova, K. O.
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Geotechnical Engineering & Applied Earth Sciences; Industrial Chemistry/Chemical Engineering; Mineral Resources; Surface active agents; Toluene
• ISSN: 0009-3092; 1573-8310
• DOI: 10.1007/s10553-014-0487-3

The effect of synthetic and natural surfactants on the stability of solutions of asphaltenes of Ashal’cha crude oil (Tatarstan) in toluene is studied. The mechanism of interaction of the surfactant having various molecular structures with asphaltene aggregates is proposed and the effect of the surfactant structure on the behavior of the surfactant as a flocculation inhibitor or initiator is studied. It is shown that the effectiveness of the inhibitors differ when they are added to solutions of wide asphaltene fraction and solutions of A1 and A2 asphaltenes. The effect of the structure of the alkyl part of the bioadditive molecule on its effectiveness as a flocculation inhibitor is described. It is found that the stability of A1 asphaltene solutions increases markedly (threefold) upon addition of crude oil wax and that this effect is absent in solutions of A2 asphaltenes and wide fraction. It is proved that the sensitivity of A2 asphaltenes to addition of wax is determined by the excess of petroleum ether used for separation of wide asphaltene fraction: presence of immobilized resins in A1 asphaltenes produces a significant effect on the change in stability of A1 asphaltene solutionsupon addition of wax.