(163d) Reversibility of Asphaltene Precipitation Considering Kinetic Effect Using Temperature-Induced Aggregation

Previous work has shown that asphaltene precipitation is a reversible process using pressure and composition to destabilize asphaltenes, but demonstrated only partial reversibility using temperature changes. Recently, it has been shown that slow kinetic effects play a critical role in the accurate monitoring of asphaltene precipitation, which has not been previously considered in reversibility studies. Consequently, there is an overarching need to investigate temperature-induced asphaltene aggregation with specific monitoring of the kinetic effect. In this work, kinetic asphaltene precipitation was investigated using temperature changes to induce asphaltene aggregation. The amount of precipitated asphaltenes as a function of time at different temperatures was obtained. It can be explicitly stated that the solubility of asphaltenes decreases with decreasing temperature. A phase diagram for asphaltene solubility as a function of solvent quality and temperature was created. In addition, temperature cycling experiments were performed to investigate the reversibility of asphaltene precipitation and thermodynamic models were applied to the results.