Review and Comprehensive Analysis of Deaggregation and Separation Methods for Asphaltene Aggregates

Asphaltenes generally exist in the form of molecular aggregates in crude oil or in petroleum residues, and asphaltene aggregates can usually cause serious problems to oil exploitation, transportation, and processing. Achieving deaggregation and separation of asphaltene aggregates is a premise and basis for molecular characterization and processing of heavy oils. Aiming at the intermolecular interactions in asphaltene molecular aggregates, it has proposed and summarized that aspahltene aggregates can be subject to deaggregation by means of five approaches, including solvent diluting, removing active sites, moderate heating, ultrasonication and on-line molecular collision. Moreover, asphaltenes can be further separated to narrow fractions for molecular-level research based on polarity difference, molecular size difference, acid-base properties, and reactivity difference.