Model molecules mimicking asphaltenes

Johan Sjöblom; Sébastien Simon; Zhenghe Xu

doi:10.1016/j.cis.2015.01.002

Model molecules mimicking asphaltenes

Adv Colloid Interface Sci. 2015 Apr:218:1-16. doi: 10.1016/j.cis.2015.01.002. Epub 2015 Jan 19.

Authors

Johan Sjöblom¹, Sébastien Simon², Zhenghe Xu³

Affiliations

¹ Ugelstad Laboratory, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
² Ugelstad Laboratory, Norwegian University of Science and Technology, 7491 Trondheim, Norway. Electronic address: sebastien.simon@chemeng.ntnu.no.
³ Department of Chemical and Materials Engineering, University of Alberta, Edmonton AB T6G 2V4, Canada.

PMID: 25638443
DOI: 10.1016/j.cis.2015.01.002

Abstract

Asphalthenes are typically defined as the fraction of petroleum insoluble in n-alkanes (typically heptane, but also hexane or pentane) but soluble in toluene. This fraction causes problems of emulsion formation and deposition/precipitation during crude oil production, processing and transport. From the definition it follows that asphaltenes are not a homogeneous fraction but is composed of molecules polydisperse in molecular weight, structure and functionalities. Their complexity makes the understanding of their properties difficult. Proper model molecules with well-defined structures which can resemble the properties of real asphaltenes can help to improve this understanding. Over the last ten years different research groups have proposed different asphaltene model molecules and studied them to determine how well they can mimic the properties of asphaltenes and determine the mechanisms behind the properties of asphaltenes. This article reviews the properties of the different classes of model compounds proposed and present their properties by comparison with fractionated asphaltenes. After presenting the interest of developing model asphaltenes, the composition and properties of asphaltenes are presented, followed by the presentation of approaches and accomplishments of different schools working on asphaltene model compounds. The presentation of bulk and interfacial properties of perylene-based model asphaltene compounds developed by Sjöblom et al. is the subject of the next part. Finally the emulsion-stabilization properties of fractionated asphaltenes and model asphaltene compounds is presented and discussed.

Keywords: Aggregation; Asphaltenes; Crude oil; Emulsion; Model compounds; Petroleum.

Publication types

Review