New Molecular Insights into Aggregation of Pure and Mixed Asphaltenes in the Presence of <i>n</i>-Octylphenol Inhibitor

Ghamartale, Ali; Zendehboudi, Sohrab; Rezaei, Nima

doi:10.1021/acs.energyfuels.0c02443

Cited by 39 publications

(49 citation statements)

References 103 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this research, two asphaltene structures with the continental structure, which is a dominant type of asphaltene structure, 40 are adopted from our previous studies to investigate the formation of hydrogen bonds. 41 Asphaltene 2 (A2) is a continental asphaltene with the potency to form hydrogen bonds due to having hydroxyl and pyridine groups, while asphaltene 3 (A3) is a similar continental asphaltene with no potential for forming hydrogen bonds (Figure 2). Also, the impact of two inhibitors, including a surfactant, namely n-octylphenol (OP), and an IL, namely 1butyl-3-methylimidazolium chloride, on asphaltene deposition in the asphaltene/n-heptane solution is studied.…”

Section: Methodology and Computational Approachmentioning

confidence: 99%

“…The distance between the closest atoms with a cutoff threshold of 0.35 nm is considered the aggregation criterion for asphaltene. 41 The z-averaged aggregation number (g z ) quantifies the aggregate size along the simulation time (see eq 2). 27,41 This analysis is implemented with an in-house python script using the MDAnalysis package and the output coordinates of asphaltene molecules after the GROMACS simulation.…”

Section: Energy Evaluationmentioning

confidence: 99%

See 1 more Smart Citation

Control of Asphaltene Deposition by Chemical Inhibitors in Calcite Pore: Molecular Dynamics Approach

Ghamartale

Zendehboudi

Mohamadi‐Baghmolaei

2022

Ind. Eng. Chem. Res.

Self Cite

View full text Add to dashboard Cite

Asphaltene deposition is a major problem during oil production and transportation that imposes extra treatment costs and reduces oil production. Historically, various chemical inhibitors have been developed to resolve the asphaltene deposition issue. However, the inhibitors are usually effective for a specific type of crude oil and asphaltene since asphaltene's nature is different for various oil samples. To develop a proper chemical inhibitor, the interaction between the inhibitor and asphaltene needs to be explored. This work employs a molecular dynamics (MD) simulation strategy to study asphaltene deposition on a calcite surface considering chemical inhibitors. Two asphaltene structures with potential to form hydrogen bond (A2) and without potential to form hydrogen bond (A3) are considered in this study. The selected inhibitors, including noctylphenol (OP) and 1-butyl-3-methylimidazolium chloride (as an ionic liquid (IL)), can form van der Waals, Coulomb, and hydrogen bonds with asphaltene molecules. The results show that the OP reduces the asphaltene aggregation by attaching to the asphaltene through hydrogen bonds. In the presence of OP, the Lennard-Jones (LJ) and Coulomb energies between asphaltene (A2) and calcite are reduced by 400 and 1000 kJ/mol units, leading to the asphaltene deposition reduction by adsorbing on the calcite surface and providing a hindrance layer. The IL is able to cope with the quadrupole−quadrupole interaction between asphaltene polyaromatic cores and reduce the asphaltene face-to-face aggregation. However, IL cannot provide a hindrance layer near the calcite surface since it does not have a long hydrocarbon tail. Therefore, the combination of inhibitors can benefit the inhibition process as both prevention mechanisms will be active. The 3:1 OP−IL ratio shows the optimum efficiency. At this ratio, inhibitors reduce the aggregation from 20 to less than 10 and the deposition rate from 1 to 0.8 compared to the case without the inhibitors. Also, the deposited aggregates have low compaction with a spherical shape, which is easy to dislodge in a dynamic situation. This research aims to demystify the asphaltene−inhibitor behaviors during asphaltene deposition, which can be a useful practice for designing of future chemical inhibitors for flow assurance issues.

show abstract

Section: Methodology and Computational Approachmentioning

confidence: 99%

Section: Energy Evaluationmentioning

confidence: 99%

Control of Asphaltene Deposition by Chemical Inhibitors in Calcite Pore: Molecular Dynamics Approach

Ghamartale

Zendehboudi

Mohamadi‐Baghmolaei

2022

Ind. Eng. Chem. Res.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Common dispersants include small molecules, polymers, and ionic liquids. − As for small molecules, the intermolecular force between sodium dodecyl benzene sulfonate, sodium dodecyl sulfate (SDS), and asphaltenes was studied. − It is found that the van der Waals force between benzene ring surfactants and asphaltenes is greater than SDS without benzene rings. In addition, octylphenol can form a strong hydrogen bond with asphaltene and inhibit asphaltene aggregation …”

Section: Introductionmentioning

confidence: 99%

Inhibition of Asphaltene Precipitation by Ionic Liquid Polymers Containing Imidazole Pendants and Alkyl Branches

Wu²,

Li³

et al. 2022

Energy Fuels

View full text Add to dashboard Cite

High polar asphaltenes are easy to precipitate and deposit in transportation pipelines and subsequent processing. Adding chemical polymer inhibitors is an effective method to inhibit asphaltene aggregation. In this work, ionic liquid polymers containing the imidazole cation and/or alkyl branches were synthesized by free radical polymerization, and anions such as the bis(trifluoromethane)sulfonimide ion (TFSI–) and [phosphoric acid bis(2-ethylhexyl)] anion (DEHP–) were introduced by substitution. The chemical structure of asphaltenes was analyzed by Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance, elemental analysis, and time-of-flight spectroscopy. It is found the asphaltene has short side chain, a low H/C, and a high polarity. The precipitation inhibition of asphaltenes and the rheological behaviors of crude oil in the presence of ionic liquid polymers were studied by measuring the initial precipitation point (IPP), turbidity, particle size distribution, and morphology of asphaltenes in model oil. In the presence of same anions (Br–, TFSI–, and DEHP–), with the increase of length of imidazole pendant branches, the IPPs increase. However, when the chain length is close to the poor solvent n-heptane, the IPP first rises, then descends. The copolymer bearing both imidazole pendants and alkyl branches can increase the IPPs. Alkyl branches can inhibit the aggregation of asphaltenes by forming layers surrounding the asphaltene aggregates. With the reduction of asphaltene agglomeration, the turbidity and particle size decrease. For polymers bearing both the imidazole pendants and alkyl branches, upon the increase of anionic electronegativity, the interactions between asphaltenes are destroyed because strong hydrogen bonding is generated between the asphaltene and the ionic liquid polymer. DEHP– has strong electronegativity and high hydrophobicity. The polymer with DEHP– and alkyl branches can increase the IPP by 30%, reduce the turbidity of model oil by 50%, reduce the size of asphaltene by 80%, and decrease the viscosity of crude oil by 36.8% at 50 °C.

show abstract

“…Zheng et al 12 found that hydrophobic ionic liquids can dissolve and disperse asphaltenes well. Ghamartale et al 13 presented that surfactants, such as n-octylphenol (OP), are more effective in reducing the aggregation of continental asphaltenes with hydroxyl and pyridine groups, while metal ions introduced through nanoparticles are undesirable in the process of crude oil refining. Ionic liquids are expensive; surfactants will dissolve in water; and their efficacy is reduced.…”

Section: Introductionmentioning

confidence: 99%

Effect of Aromatic Pendants in a Maleic Anhydride-co-Octadecene Polymer on the Precipitation of Asphaltenes Extracted from Heavy Crude Oil

Cheng

Zou

et al. 2021

Energy Fuels

View full text Add to dashboard Cite

The precipitation and deposition of asphaltenes often cause great troubles to the recovery and transportation of crude oil. Adding polymer inhibitors is an effective approach to prevent asphaltenes from clogging. In this study, maleic anhydrideco-octadecene copolymers with imidazolyl, phenyl, and pyridyl pendants were synthesized. The inhibition behaviors of two extracted asphaltenes in the presence of these copolymers were investigated, which were also identified by the rheological tests of the heavy crude oil sample. The chemical structure of both asphaltenes was analyzed by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), elemental analysis, and time-of-flight (TOF) spectrometry. Both asphaltenes A and B have a high aromaticity and low H/C. However, asphaltene B has a much higher aromaticity and polarity than that of asphaltene A. Ultraviolet−visible spectroscopy, turbidity meter, and dynamic light scattering (DLS) were employed to determine the precipitation behaviors of asphaltenes in the absence and presence of copolymers. The influence of intrinsic properties of asphaltenes, polymer concentration, and aromatic group grafting ratio on asphaltene precipitation were also compared. It is found that the initial precipitation point (IPP) of both asphaltenes is increased most by the copolymer containing 2-aminopyridine (PMO-2-P), while the copolymer containing N-(3-aminopropyl)imidazole (PMO-I) shows the worst inhibition performance. It is because that pyridine group has a stronger adsorption capacity with asphaltene than the imidazole group. The effect of various functional groups in copolymers on inhibiting asphaltene precipitation conforms to the following sequence: 2-aminopyridine > aniline > 4aminopyridine > N-(3-aminopropyl)imidazole. It is also found that high polymer concentration and grafting ratio are beneficial to inhibit the asphaltene precipitation. As a result of the π−π conjugation and hydrogen-bonding attractions between the aromatic groups in the copolymers and the asphaltenes, the polymers can be stably adsorbed onto the surface of the asphaltenes and prevent their aggregation.

show abstract

New Molecular Insights into Aggregation of Pure and Mixed Asphaltenes in the Presence of n-Octylphenol Inhibitor

Cited by 39 publications

References 103 publications

Control of Asphaltene Deposition by Chemical Inhibitors in Calcite Pore: Molecular Dynamics Approach

Control of Asphaltene Deposition by Chemical Inhibitors in Calcite Pore: Molecular Dynamics Approach

Inhibition of Asphaltene Precipitation by Ionic Liquid Polymers Containing Imidazole Pendants and Alkyl Branches

Effect of Aromatic Pendants in a Maleic Anhydride-co-Octadecene Polymer on the Precipitation of Asphaltenes Extracted from Heavy Crude Oil

Contact Info

Product

Resources

About