Molecular Mechanisms of Suppressing Asphaltene Aggregation and Flocculation by Dodecylbenzenesulfonic Acid Probed by Molecular Dynamics Simulations

Jiang, Bin; Zhang, Rongya; Yang, Na; Chen, Hou; Sun, Yongli; Jian, Cuiying; Liu, Lan; Xu, Zhenghe

doi:10.1021/acs.energyfuels.9b00821

Cited by 35 publications

(15 citation statements)

References 59 publications

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“…S.4, probably a sign of a preference of either one or the other to interact with this region of the simulation box). When demulsifiers are also present, such interactions are also lowered, probably due to the fact that demulsifiers interacting with porphyrins and/or asphaltenes reduce the interaction among these species and water, as it was recently indicated by Jiang et al (2019).…”

Section: With Demulsifiermentioning

confidence: 82%

Role of the porphyrins and demulsifiers in the aggregation process of asphaltenes at water/oil interfaces under desalting conditions: a molecular dynamics study

et al. 2020

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Breaking water-in-oil emulsions during the refining of crude oils is an important step before any upgrading process is started. Asphaltene molecules are incriminated as playing an important role in this phenomenon. Unraveling the mechanisms behind the affinity between them and water is a key step to understand how to break these emulsions more easily and require lower amounts of demulsifiers. Choosing which demulsifier molecule(s) to use is also primordial, but to do so rationally, one needs to know which are the molecular interactions in place between asphaltenes, porphyrins and water so that demulsifiers are chosen to destabilize a specific physical-chemical interaction. In this paper, we study the interactions arising between asphaltenes and porphyrins and six different molecules potentially displaying a demulsification action in the presence of water/oil interfaces. We demonstrate that the ionic demulsifier molecules present an interesting potential to either interact strongly with water, replacing asphaltenes in this interaction, or to interact with the active sites of asphaltenes, deactivating them and avoiding any asphaltenic interfacial activity. Finally, we also found that although asphaltenes do not migrate spontaneously toward the water/oil interfaces, porphyrins do so rather easily. This indicates that porphyrins do have an important activity at the water/oil interface.

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Section: With Demulsifiermentioning

confidence: 82%

Role of the porphyrins and demulsifiers in the aggregation process of asphaltenes at water/oil interfaces under desalting conditions: a molecular dynamics study

et al. 2020

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“…The average number of hydrogen bonds between the molecular model, as well as the molecular model and water, was calculated to determine the influence of DDA and NaOL molecules on the stability of aggregate with different molar ratios ( Table 2 ). In our simulation, r DA (distance between donor-acceptor) ≤ 0.35 nm and θ ADH (angle of acceptor-donor-hydrogen) ≤ 30° were chosen to use as the standard for calculating a hydrogen bond [ 36 , 43 ]. We observed that hydrogen bond did not form between identical molecules in all systems, such as DDA-DDA and NaOL-NaOL.…”

Section: Resultsmentioning

confidence: 99%

“…Subsequent MD simulations and analysis of the behavior of surfactants in aqueous solution were completed by virtue of Gromacs2018 and its built-in analytical tools. VMD 1.9.3 was used to visualize the evolution of molecular structures varying with time [ 29 , 35 , 36 ]. The structure files of NaOL and DDA were imported into ATB (Automated Topology Builder) to establish the initial topology files after optimizing [ 36 , 37 , 38 ], which was a significant foundation to implement molecular dynamics successfully.…”

Section: Computational Detailsmentioning

confidence: 99%

“…VMD 1.9.3 was used to visualize the evolution of molecular structures varying with time [ 29 , 35 , 36 ]. The structure files of NaOL and DDA were imported into ATB (Automated Topology Builder) to establish the initial topology files after optimizing [ 36 , 37 , 38 ], which was a significant foundation to implement molecular dynamics successfully. Almost all the necessary information to build the molecules was contained in the topology file, including bonded force field parameters (bonds, angles, and dihedrals) and nonbonded force field parameters (atom types and charges).…”

Section: Computational Detailsmentioning

confidence: 99%

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Self-Assembly of NaOL-DDA Mixtures in Aqueous Solution: A Molecular Dynamics Simulation Study

Wang

Liu

et al. 2021

Molecules

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The self-assembly behaviors of sodium oleate (NaOL), dodecylamine (DDA), and their mixtures in aqueous solution were systematically investigated by large-scale molecular dynamics simulations, respectively. The interaction mechanisms between the surfactants, as well as the surfactants and solvent, were revealed via the radial distribution function (RDF), cluster size, solvent-accessible surface area (SASA), hydrogen bond, and non-bond interaction energy. Results showed that the molecules more easily formed aggregates in mixed systems compared to pure systems, indicating higher surface activity. The SASA values of DDA and NaOL decreased significantly after mixing, indicating a tighter aggregation of the mixed surfactants. The RDF results indicated that DDA and NaOL strongly interacted with each other, especially in the mixed system with a 1:1 molar ratio. Compared to van der Waals interactions, electrostatic interactions between the surfactant molecules were the main contributors to the improved aggregation in the mixed systems. Besides, hydrogen bonds were found between NaOL and DDA in the mixed systems. Therefore, the aggregates in the mixed systems were much more compact in comparison with pure systems, which contributed to the reduction of the repulsive force between same molecules. These findings indicated that the mixed NaOL/DDA surfactants had a great potential in application of mineral flotation.

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“…Small-molecule asphaltene dispersants include acidic amphiphilic molecules, amides and imides and ionic liquids [6,7]. For example, dodecyl benzene sulfonic acid (DBSA) and dimethyl amide (DA) can form hydrogen bonds with asphaltene molecules, generating acid-base force to prevent the aggregation of asphaltenes and improve the fluidity of crude oil [8,9]. However, most small-molecule asphaltene dispersants have problems such as a high cost of preparation and poor compatibility with different crude oils.…”

Section: Introductionmentioning

confidence: 99%

Asphaltene Inhibition and Flow Improvement of Crude Oil with a High Content of Asphaltene and Wax by Polymers Bearing Ultra-Long Side Chain

Lu²,

Niu³

et al. 2021

Energies

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A high content of asphaltene and wax in crude oil leads to difficulties in the recovery and transportation of crude oil due to the precipitation of asphaltenes and the deposition of waxes. Comb-like polymers were found to be capable of inhibiting the aggregation of asphaltenes and crystallization of waxes. In this work, comb-like bipolymers of α-olefins/ultra-long chain (C18, C22 and C28) alkyl acrylate were synthesized and characterized by FT-IR and 1H NMR spectra. The results show that, for a model oil containing asphaltene, the initial precipitation point (IPP) of asphaltene was prolonged by UV, and the asphaltene particle size was reduced after adding the biopolymers, as revealed by dynamitic light scattering (DLS). The bipolymer containing the longer alkyl chain had a better asphaltene inhibition effect. However, DSC and rheological results show that the wax appearance temperature (WAT) of the typical high asphaltene and high wax content of crude oil was obviously reduced by adding bipolymers with shorter alkyl chains. The bipolymer (TDA2024-22) with a mediate alkyl chain (C22) reduced the viscosity and thixotropy of the crude oil by a much larger margin than others. Compared with the previously synthesized bipolymer with phenyl pendant (PDV-A-18), TDA2024-22 exhibited a better performance. Therefore, bipolymers with appropriate alkyl side chains can act as not only the asphaltene inhibitors but also wax inhibitors for high asphaltene and wax content of crude oil, which has great potential applications in the oil fields.

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Molecular Mechanisms of Suppressing Asphaltene Aggregation and Flocculation by Dodecylbenzenesulfonic Acid Probed by Molecular Dynamics Simulations

Cited by 35 publications

References 59 publications

Role of the porphyrins and demulsifiers in the aggregation process of asphaltenes at water/oil interfaces under desalting conditions: a molecular dynamics study

Role of the porphyrins and demulsifiers in the aggregation process of asphaltenes at water/oil interfaces under desalting conditions: a molecular dynamics study

Self-Assembly of NaOL-DDA Mixtures in Aqueous Solution: A Molecular Dynamics Simulation Study

Asphaltene Inhibition and Flow Improvement of Crude Oil with a High Content of Asphaltene and Wax by Polymers Bearing Ultra-Long Side Chain

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