Effects of the N, O, and S heteroatoms on the adsorption and desorption of asphaltenes on silica surface: A molecular dynamics simulation

Yun Bai, Hong Sui, Xiaoyan Liu, Lin He*, Xingang Li, Esben Thormann

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The adsorption and desorption of asphaltene on silica surface is highly dependent on the heteroatoms present in its structure. Herein, some model asphaltene molecules with different heteroatoms (i.e., N, O, S) at different positions (in the aromatic cores, in the middle and termination of alkane side chains) are selected as the adsorbates to investigate their adsorption and desorption behaviors on silica surface through molecular dynamics (MD) simulation. Results reveal that the characteristic adsorption configuration of asphaltenes is ascribed to the competition between the asphaltene-silica interaction and π–π stacking interaction among the asphaltene polyaromatic rings. The presence of heteroatoms is found to be able to strengthen the interactions between asphaltenes and silica, depending on their type and location. For example, the terminal polar groups, especially the carboxyl (COOH), exhibit the greatest contribution to the electrostatic interaction (increasing from −81 to −727 kJ/mol). The S atoms are also found to increase the van der Waals interaction energies by 25%. According to the equilibrium desorption conformation and density profile, the presence of heteroatoms is found to significantly hinder the desorption of asphaltenes from silica due to the enhanced polar interactions. The impeded desorption is also confirmed by the slower detachment of asphaltenes based on the time-dependent interaction energies and center of mass (COM) distances analysis. Additionally, the terminal polar groups lead to extraordinary desorption properties of asphaltenes. It is observed that the strong asphaltene-silica and asphaltene-water interactions coexist in these systems due to the high polarity and hydrophilicity of the terminal polar groups.
Original languageEnglish
JournalFuel
Volume240
Pages (from-to)252-261
Number of pages10
ISSN0016-2361
DOIs
Publication statusPublished - 2019

Keywords

  • Asphaltene
  • Heteroatom
  • Adsorption
  • Molecular dynamic solutions

Cite this

@article{7f100356845d44ecaafecf011fbb334a,
title = "Effects of the N, O, and S heteroatoms on the adsorption and desorption of asphaltenes on silica surface: A molecular dynamics simulation",
abstract = "The adsorption and desorption of asphaltene on silica surface is highly dependent on the heteroatoms present in its structure. Herein, some model asphaltene molecules with different heteroatoms (i.e., N, O, S) at different positions (in the aromatic cores, in the middle and termination of alkane side chains) are selected as the adsorbates to investigate their adsorption and desorption behaviors on silica surface through molecular dynamics (MD) simulation. Results reveal that the characteristic adsorption configuration of asphaltenes is ascribed to the competition between the asphaltene-silica interaction and π–π stacking interaction among the asphaltene polyaromatic rings. The presence of heteroatoms is found to be able to strengthen the interactions between asphaltenes and silica, depending on their type and location. For example, the terminal polar groups, especially the carboxyl (COOH), exhibit the greatest contribution to the electrostatic interaction (increasing from −81 to −727 kJ/mol). The S atoms are also found to increase the van der Waals interaction energies by 25{\%}. According to the equilibrium desorption conformation and density profile, the presence of heteroatoms is found to significantly hinder the desorption of asphaltenes from silica due to the enhanced polar interactions. The impeded desorption is also confirmed by the slower detachment of asphaltenes based on the time-dependent interaction energies and center of mass (COM) distances analysis. Additionally, the terminal polar groups lead to extraordinary desorption properties of asphaltenes. It is observed that the strong asphaltene-silica and asphaltene-water interactions coexist in these systems due to the high polarity and hydrophilicity of the terminal polar groups.",
keywords = "Asphaltene, Heteroatom, Adsorption, Molecular dynamic solutions",
author = "Yun Bai and Hong Sui and Xiaoyan Liu and Lin He and Xingang Li and Esben Thormann",
year = "2019",
doi = "10.1016/j.fuel.2018.11.135",
language = "English",
volume = "240",
pages = "252--261",
journal = "Fuel",
issn = "0016-2361",
publisher = "Elsevier",

}

Effects of the N, O, and S heteroatoms on the adsorption and desorption of asphaltenes on silica surface: A molecular dynamics simulation. / Bai, Yun; Sui, Hong; Liu, Xiaoyan; He, Lin; Li, Xingang; Thormann, Esben.

In: Fuel, Vol. 240, 2019, p. 252-261.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Effects of the N, O, and S heteroatoms on the adsorption and desorption of asphaltenes on silica surface: A molecular dynamics simulation

AU - Bai, Yun

AU - Sui, Hong

AU - Liu, Xiaoyan

AU - He, Lin

AU - Li, Xingang

AU - Thormann, Esben

PY - 2019

Y1 - 2019

N2 - The adsorption and desorption of asphaltene on silica surface is highly dependent on the heteroatoms present in its structure. Herein, some model asphaltene molecules with different heteroatoms (i.e., N, O, S) at different positions (in the aromatic cores, in the middle and termination of alkane side chains) are selected as the adsorbates to investigate their adsorption and desorption behaviors on silica surface through molecular dynamics (MD) simulation. Results reveal that the characteristic adsorption configuration of asphaltenes is ascribed to the competition between the asphaltene-silica interaction and π–π stacking interaction among the asphaltene polyaromatic rings. The presence of heteroatoms is found to be able to strengthen the interactions between asphaltenes and silica, depending on their type and location. For example, the terminal polar groups, especially the carboxyl (COOH), exhibit the greatest contribution to the electrostatic interaction (increasing from −81 to −727 kJ/mol). The S atoms are also found to increase the van der Waals interaction energies by 25%. According to the equilibrium desorption conformation and density profile, the presence of heteroatoms is found to significantly hinder the desorption of asphaltenes from silica due to the enhanced polar interactions. The impeded desorption is also confirmed by the slower detachment of asphaltenes based on the time-dependent interaction energies and center of mass (COM) distances analysis. Additionally, the terminal polar groups lead to extraordinary desorption properties of asphaltenes. It is observed that the strong asphaltene-silica and asphaltene-water interactions coexist in these systems due to the high polarity and hydrophilicity of the terminal polar groups.

AB - The adsorption and desorption of asphaltene on silica surface is highly dependent on the heteroatoms present in its structure. Herein, some model asphaltene molecules with different heteroatoms (i.e., N, O, S) at different positions (in the aromatic cores, in the middle and termination of alkane side chains) are selected as the adsorbates to investigate their adsorption and desorption behaviors on silica surface through molecular dynamics (MD) simulation. Results reveal that the characteristic adsorption configuration of asphaltenes is ascribed to the competition between the asphaltene-silica interaction and π–π stacking interaction among the asphaltene polyaromatic rings. The presence of heteroatoms is found to be able to strengthen the interactions between asphaltenes and silica, depending on their type and location. For example, the terminal polar groups, especially the carboxyl (COOH), exhibit the greatest contribution to the electrostatic interaction (increasing from −81 to −727 kJ/mol). The S atoms are also found to increase the van der Waals interaction energies by 25%. According to the equilibrium desorption conformation and density profile, the presence of heteroatoms is found to significantly hinder the desorption of asphaltenes from silica due to the enhanced polar interactions. The impeded desorption is also confirmed by the slower detachment of asphaltenes based on the time-dependent interaction energies and center of mass (COM) distances analysis. Additionally, the terminal polar groups lead to extraordinary desorption properties of asphaltenes. It is observed that the strong asphaltene-silica and asphaltene-water interactions coexist in these systems due to the high polarity and hydrophilicity of the terminal polar groups.

KW - Asphaltene

KW - Heteroatom

KW - Adsorption

KW - Molecular dynamic solutions

U2 - 10.1016/j.fuel.2018.11.135

DO - 10.1016/j.fuel.2018.11.135

M3 - Journal article

VL - 240

SP - 252

EP - 261

JO - Fuel

JF - Fuel

SN - 0016-2361

ER -