Abstract
Carboxyl asphaltene is commonly discussed in the petroleum industry. In most conditions, electroneutral carboxyl asphaltene molecules can be deprotonated to become carboxylate asphaltenes. Both in crude oil and at the oil/water interface, the characteristics of anionic carboxylate asphaltenes are different than those of the carboxyl asphaltenes. In this paper, molecular dynamics (MD) simulations are utilized to study the structural features of different asphaltene molecules, namely, C5 Pe and anionic C5 Pe, at the molecular level. In crude oil, the electroneutral C5 Pe molecules prefer to form a steady face-to-face stacking, while the anionic C5 Pe molecules are inclined to form face-to-face stacking and T-shaped II stacking because of the repulsion of the anionic headgroups. Anionic C5 Pe has a distinct affinity to the oil/water interface during the simulation, while the C5 Pe molecules persist in the crude oil domain. A three-stage model of anionic C5 Pe molecules adsorbed at the oil/water interface is finally developed.
Original language | English (US) |
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Pages (from-to) | 7368-7376 |
Number of pages | 9 |
Journal | Energy & Fuels |
Volume | 28 |
Issue number | 12 |
DOIs | |
State | Published - Nov 24 2014 |
Externally published | Yes |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: We gratefully appreciate the financial support from NSFC Project (No. 21173128), Key NSF Project of Shandong province (No. ZR2011BZ0003 and No. ZR2012BM004), and the HESTP Project of Shandong Province (J13LD01). The authors thank Dr. Bradley D. Rose, King Abdullah University of Science and Technology, for helpful discussions and manuscript editing. We are thankful for support by Program for Scientific Research Innovation Team in Colleges and Universities of Shandong Province.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.