Study of the aggregation and adsorption of asphaltene sub-fractions A1 and A2 by white light interferometry: Importance of A1 sub-fraction in the aggregation process

Castillo, Jimmy; Ranaudo, María Antonieta; Fernández, Alberto; Piscitelli, Vincent; Maza, M. P.; Navarro, Abel E.

doi:10.1016/j.colsurfa.2013.03.016

Cited by 24 publications

(29 citation statements)

References 21 publications

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“…The last studied sample was one asphaltene enriched in resins, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 solubility purposes. 57 A second interpretation, more alike to what was discussed in the preceding paragraphs, is provided by the works of Acevedo, Castillo and coworkers, 58,59 who showed that low solubility parameter asphaltenes fractions were found able to improve dissolution of "core asphaltenes" and modify their adsorptivity over solid surfaces. It is believed that low solubility parameter asphaltenes as described by …”

Section: Sample Viscosities As Evidence Of Cohesive Forcesmentioning

confidence: 84%

Effect of Precipitating Conditions on Asphaltene Properties and Aggregation

et al. 2015

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Asphaltenes, resins and maltenes physical isolation procedures involving different alkane precipitants and solvent/sample ratios were applied in this work to Athabasca bitumen vacuum residue. Samples were characterized by Solubility Profiling, Size Exclusion Chromatography, Fluorescence Spectroscopy, X-ray Photoelectron Spectroscopy and density-viscosity analyses. Isolated fractions were found to display systematic property changes. Thus, it was found that denser, more polar, higher molecular weight (MW), more viscous, red shifted fluorescence materials were sequentially ranked as follows: Solvent extracted asphaltenes -C7 (unwashed) asphaltenes -C5 (unwashed) asphaltenes -resins -maltenes. Intermolecular aggregation for these fractions was determined to follow the same order. Decreasing contents of resins in the same order were found to increase aggregation phenomena.This work further reported on aspects of possible practical interest, i.e., the liquid nature of asphaltenes at 300°C and, possible existence of oxidative reactions affecting fractions isolation that follow standard methods which do not contemplate inert atmospheres. Preliminary assessment of chemical functionalities within isolated fractions highlighted on the possible enrichment of pyrrolic compounds within resins and oxygen functionalities in asphaltenes.

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Section: Sample Viscosities As Evidence Of Cohesive Forcesmentioning

confidence: 84%

Effect of Precipitating Conditions on Asphaltene Properties and Aggregation

et al. 2015

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“…From an earlier study of asphaltene solubility fractions using fluorescent depolarization technique, it was found that different solubility fractions have the same molecular species but differ in the amount of each species. Asphaltenes tend to form aggregates even in a good solvent . Upon decreasing the solvent aromaticity, the asphaltene aggregates grow in average size and molecular weight along with the increasing heptane content, ,,, and the adsorbed film thickness increases with the size of aggregates in the solution .…”

Section: Results and Discussionmentioning

confidence: 99%

“…Asphaltenes tend to form aggregates even in a good solvent. 80 Upon decreasing the solvent aromaticity, the asphaltene aggregates grow in average size and molecular weight along with the increasing heptane content, 77,79,81,82 and the adsorbed film thickness increases with the size of aggregates in the solution. 83 The average aggregate size continues to grow until the solution reaches the solubility limit, above which the addition of heptane would lead to significant agglomeration and precipitation, leaving smaller asphaltene aggregates in the solution.…”

Section: Adsorption Of Crude Oil In Toluene On Amentioning

confidence: 99%

Study of Asphaltene Deposition onto Stainless-Steel Surfaces Using Quartz Crystal Microbalance with Dissipation

et al. 2020

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Asphaltene deposition is one of the major flow assurance problems in upstream and downstream crude oil recovery operations. In order to prevent potential loss and reduce downtime due to asphaltenes, it is critical to understand the physics of asphaltene adsorption. This study presents a preliminary investigation of asphaltene adsorption from crude oils onto stainless-steel surfaces using the quartz crystal microbalance with dissipation (QCM-D) technique and proposes a theoretical interpretation of the deposition mechanism for asphaltene molecules. The kinetics of deposition at different concentrations was examined, and the sizes of the deposited asphaltene molecules were estimated from the initial adsorption kinetics. Numerical analysis of the experimental data using the theoretical two-step deposition model was attempted, and the optimized adsorption parameters proved to be quite close to those values obtained for some rock types in earlier adsorption studies. Despite asphaltene precipitation increasing with increasing heptane percentage, the deposition of asphaltenes was found to be maximum at 70 vol% heptane content. The performance of a commercial inhibitor was then assessed under different conditions using the developed experimental metrics, and the inhibitor was found to be able to reduce the maximum deposition amount at the solubility with 70 vol% heptane fraction, which happens to be the same condition that generates the largest amount of deposition. The information gained on the solubility effect and inhibitor performance is essential to help the industry better manage asphaltene-related flow assurance problems in crude oil recovery.

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“…The mechanism of asphaltene transport from the bulk to the interface (liquid-liquid, liquid-solid) and subsequent association at the interface (interfacial aging) has been studied using a number of experimental techniques, including tensiometry, 19 light absorption, 20 UV spectrometry, 21 interferometry, 22 quartz crystal microbalance, 23 ellipsometry 24 and surface force apparatus. 25 Despite continued effort there remains uncertainty or areas related to the physical and mechanical properties of the adsorbed layer for discussion.…”

Section: Interfacial Activitymentioning

confidence: 99%