Effects of Temperature and Pressure on Asphaltenes Agglomeration in Toluene. A Light, X-ray, and Neutron Scattering Investigation

• Published in: Energy & fuels Vol. 18; no. 5; pp. 1243 - 1249
• Main Authors: Espinat, D, Fenistein, D, Barré, L, Frot, D, Briolant, Y
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.09.2004
• Subjects: Applied sciences; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fuels; Asphaltene; Modification; Light scattering; Toluene; Temperature effect; Agglomeration; High temperature; Small angle X ray scattering; Aggregation; Pressure effect; Small angle neutron scattering; Dynamics; X ray scattering
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/ef030190+

Small-angle X-ray scattering (SAXS), small-angle neutron scattering (SANS), and dynamic light scattering (DLS) are used to study the temperature dependence of asphaltene aggregate sizes in toluene solutions. A large range of aggregate sizes is covered by combining the three scattering methods. The effect of temperature on aggregate size is also investigated over a considerable temperature range. A huge modification of asphaltene macrostructure is observed. At high temperatures, reversible aggregation of asphaltene leads to stable small entities. When decreasing the temperature, irreversible aggregation of asphaltene occurs, corresponding to a large increase of the aggregate size. We have also investigated the effect of pressure on asphaltene solution in toluene as a function of temperature. Our results indicate that pressure has a minor effect, which is much less important than that of temperature, on the weight of the asphaltene aggregates.