Simple methods for the separation of various subfractions from coal and petroleum asphaltenes.

This review contains some actual information about more interesting and perspective methods of coal and petroleum asphaltenes separation, fractionation, extraction, adsorption, and complexation. These are the most convenient and simple methods for isolating various components of asphaltenes. These methods are based on the electrostatic and donor-acceptor properties of the used reagents and on unique and incompletely understood phenomena. A promising area is the use of ionic liquids as a convenient and mild isolation of asphaltene components. Understanding and identifying the diverse molecular composition of asphaltene components will help one to understand their nature more fully in the future and, more precisely, physicochemical interactions and phenomena.