Structure of Petroleum Asphaltene and Its Significance

Abstract

The accumulated experimental results over the last five decades in the field of high molecular-weight fractions of petroleum has helped us to build a working model for the average structure of resins, asphaltenes, and other bitumens. The complex nature of the average structure requires analysis in terms of both a micro-structure (fine) and a macro-structure (bulk). The former, which is obtained from chemical methods, can be defined by a number of structural parameters such as aromaticity, substitution extent, etc.; the latter, obtained by physical approaches, deals with dissociation-association, charge-transfer, excitation, defect centers, etc. This macro-molecular model of multipolymer nature is consistent with models of geochemically related substances. Applications based on the structural information derived from heavy ends not only include prediction of physical properties and chemical reactions, but also include improvement of existing technology. In the geochemical domain it is anticipated that there will be better methods for prospecting and production. Better insight can be directed toward refining and product evaluation. Existing asphalt coating and paving technology can be put on a more sound scientific basis. Better source identification and flocculation techniques can be developed for environmental protection against oil spillage.