Molecular Dynamics Study of Nanoaggregation in Asphaltene Mixtures: Effects of the N, O, and S Heteroatoms

Abstract

In this paper the aggregation of asphaltenes is studied for two asphaltene molecule families, namely PA3 and CA22 analogues, based on the work of Schuler et al. (JACS, 2015, 137, 31, 9870). The chemical characteristics of these molecules were screened by changing the heteroatoms on the backbone and the lateral chain-ends. These molecules were mixed together with different relative concentrations and for the first time the aggregation of different asphaltenes was determined using molecular dynamics simulations (MDS). The results show that the interaction energies vary for different heteroatom arrangement within a given structure and depend on the type of asphaltene. Moreover, we showed that the chain-ends have a crucial role on this phenomenon.

Asphaltene aggregation onset during high-salinity waterflooding of reservoirs (a molecular dynamic study)

“…Results indicate that van der Waals forces are the prevailing interaction between asphaltenes. This finding is in line with many previous MD studies that reported asphaltene aggregation (see for example: Khalaf and Mansoori, 2018;Sedghi et al, 2013;Silva et al, 2016). PW group exhibits the greatest attraction between asphaltene molecules.…”

Redox activity of nickel and vanadium porphyrins: a possible mechanism behind petroleum genesis and maturation?

“…In previous work based on molecular dynamics simulations, we have shown that (i) polar acidic lateral chains play a major role favoring this aggregation pattern 18,19 and (ii) porphyrins are inherently present in these molecular aggregates forming multiple H-bonds with asphaltenes and water. 20 More particularly, we have also shown that vanadium porphyrins play an important role on asphaltene aggregation and water/oil interfacial activity.…”

Asphaltene aggregation studied by molecular dynamics simulations: role of the molecular architecture and solvents on the supramolecular or colloidal behavior

“…It does not depend on the polarity of the conjugated core (the presence of heteroatoms) (Sedghi and Goual 2009;Sedghi et al 2013), even if the stability (energy of interaction) of the nanoaggregate indeed does (Santos Silva et al 2016). However, given the range of energies found for the π − π interactions, asphaltene decomposition (coke formation) would take place before any dissociation of this interaction could be achieved (Takanohashi et al 2003).…”