Asphalt flocculation and deposition IV. Dynamic evolution of the heavy organic compounds

The dynamics of formation of asphalt and asphaltene aggregates are studied. Three different characteristics of the aggregates and their time evolution are compared, namely their precipitation, small-angle scattering, and molecular weight distributions. Thin-layer chromatography is used for the precipitation measurements, and its performance is compared with that of the standard IP-143 method. The effects of the precipitating agent on the structure and the precipitation properties are also investigated, as is the time-dependence of the amount of the resin in the solution. It is shown that the short-and long-time properties of the asphalt and asphaltene aggregates are very different, and the experimental data that are collected shortly after the aggregates are formed can be misleading. Moreover, the time dependence of the amounts of precipitated asphalt and asphaltene aggregates are also very different. A novel scaling approach is proposed for predicting the time-dependence of the amount of precipitation, whose predictions are in excellent agreement with the data. (C) 1997 Elsevier Science Ltd.