Analytical Information on the Asphaltenes from a Few Standard Characterization Techniques

Peksöz, Ahmet; Akay, Sertan Kemal; Kaya, Yunus; Ovalıoğlu, Hüseyin; Kaynak, Gönül; Yalçiner, Aytaç

doi:10.1080/15567030903397909

Cited by 9 publications

(11 citation statements)

References 14 publications

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“…Asphaltene elemental compositions shown in Figure 5 consist of highly pericondensed aromatic structures. 7,90 Similar structures have been reported for asphaltenes produced by deep hydroconversion, with condensed coke-like structures that approach the PAH stability limit. 54 Asphaltene Compositional Space.…”

Section: ■ Results and Discussionsupporting

confidence: 65%

Heavy Petroleum Composition. 4. Asphaltene Compositional Space

2013

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Asphaltenes and maltenes are defined operationally by solubility (in, e.g., heptane). Asphaltenes self-associate in solution and form putative nanoaggregates composed of approximately 6−10 asphaltene monomers per subunit. Bulk measurements indicate that asphaltenes are more aromatic than maltenes and contain more heteroatoms and metals (nitrogen, sulfur, oxygen, nickel, and vanadium). Numerous direct imaging, molecular diffusion, and mass spectral results agree that asphaltenes and maltenes are defined by similar, overlapped carbon number ranges, drastically restricting the acceptable carbon number and aromaticity "compositional space" for asphaltene compounds. Thus, when viewed by a plot of aromaticity versus carbon number for a given heteroatom class, asphaltenes must occupy different compositional space than maltenes because they share the same carbon number range but differ in bulk aromaticity and solution phase behavior. Boduszynski's work supported overlapping asphaltene/maltene molecular weights, and he proposed that "high boiling does not necessitate high molecular weight" [Boduszynski, M. M. Composition of heavy petroleums. 1. Molecular weight, hydrogen deficiency, and heteroatom concentration as a function of atmospheric equivalent boiling-point up to 1400 °F (760 °C). Energy Fuels 1987, 1 (1) 2−11]. However, his limited mass spectral resolution precluded direct molecular-level confirmation. Current mass spectral results combined with results published in parts 1 (

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Section: ■ Results and Discussionsupporting

confidence: 65%

Heavy Petroleum Composition. 4. Asphaltene Compositional Space

2013

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“…Advances in analytical technology can now address the wide polydispersity associated with high-boiling (up to 400 °C) petroleum fractions but still provides limited molecular-level detail for asphaltenes. 19,20 Vapor pressure osmometry (VPO), diffusion measurement, 21−24 gel permeation chromatography (GPC), and sizeexclusion chromatography (SEC) applied to asphaltenes have produced a wide range of average molecular weights, thought to be influenced by concentration-dependent self-association. 1,22,25−29 Asphaltene molecular weight measurements are inconclusive because of asphaltene self-association at sub-parts per billion (ppb) concentrations.…”

Section: ■ Introductionmentioning

confidence: 99%

Heavy Petroleum Composition. 3. Asphaltene Aggregation

et al. 2013

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Molecular characterization of asphaltenes by conventional analytical techniques is a challenge because of their compositional complexity, high heteroatom content, and asphaltene aggregate formation at low concentrations. Thus, most common characterization techniques rely on bulk properties or solution-phase behavior (solubility). Proposed over 20 years ago, the Boduszynski model proposes a continuous progression in petroleum composition (molecular weight, structure, and heteroatom content) as a function of the atmospheric equivalent boiling point. Although exhaustive detailed compositional analysis of petroleum distillates validates the continuum model, the available compositional data from asphaltene fractions supports the extension of the continuum model into the nondistillables only indirectly. Asphaltenes, defined by their insolubility in alkane solvents, accumulate in high-boiling fractions and form stable aggregate structures at low parts per billion (ppb) concentrations, far below the concentration required for most mass analyzers. Here, we present direct mass spectral detection of stable asphaltene aggregates at lower concentrations than previously published and observe the onset of asphaltene nanoaggregate formation by time-of-flight mass spectrometry (TOF−MS). We conclude that a fraction of asphaltenes must be present as nanoaggregates (not monomers) in all atmospheric pressure and laser-based ionization methods. Thus, those methods access a subset of the asphaltene continuum.

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“…More detailed analytical information determined by various methods, such as SEM, infrared spectroscopy, and X-ray techniques on the asphaltene, which was used in this work as a coating material, has also been given in an earlier work (Peksoz et al, 2011). The asphaltenes obtained by using different crude petroleum, which is originated from different regions of the world, have different physical and chemical characteristics, such as molecular structure and paramagnetic behavior.…”

Section: Discussionmentioning

confidence: 96%

The Asphaltene Coating Effect on GMI Response in Fe_4.3Co_68.2Si_12.5B₁₅Amorphous Microwires

Peksöz

Caylak

Taysioglu

et al. 2013

Energy Sources, Part A: Recovery, Utilization, and Environmenta

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The asphaltene was extracted from asphalt cement with penetration grade 60, which is extracted from crude Libya petroleum. The asphalt cement was taken from Tüpraş Refinery in Izmit-Turkey. The asphalt cement was dissolved in 10 times excess volume of benzene, precipitated in a further 10 times excess volume of petroleum ether with a boiling range of 40-60 ı C (i.e., 1 part asphalt cement, 10 parts benzene, and 100 parts petroleum ether). The resultant precipitate was collected by filtration and dried. The asphaltene so obtained was dark brown semi-solids. The percentage of asphaltene in the asphalt cement was 30% by weight. Fe 4:3 Co 68:2 Si 12:5 B 15 amorphous microwires, with a diameter of 120 m and 12 cm long, were coated with these paramagnetic asphaltene molecules. The giant magneto-impedance effect was experimentally measured on uncoated and asphaltene coated Co-rich amorphous wires. In the asphaltene coated sample, a very high value of the giant magneto-impedance effect ratio up to 42% was achieved at 4.0 MHz. As far as is known, such a giant magneto-impedance enhancement is reported for the first time by an asphaltene coating process.

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Analytical Information on the Asphaltenes from a Few Standard Characterization Techniques

Cited by 9 publications

References 14 publications

Heavy Petroleum Composition. 4. Asphaltene Compositional Space

Heavy Petroleum Composition. 4. Asphaltene Compositional Space

Heavy Petroleum Composition. 3. Asphaltene Aggregation

The Asphaltene Coating Effect on GMI Response in Fe_4.3Co_68.2Si_12.5B₁₅Amorphous Microwires

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Analytical Information on the Asphaltenes from a Few Standard Characterization Techniques

Cited by 9 publications

References 14 publications

Heavy Petroleum Composition. 4. Asphaltene Compositional Space

Heavy Petroleum Composition. 4. Asphaltene Compositional Space

Heavy Petroleum Composition. 3. Asphaltene Aggregation

The Asphaltene Coating Effect on GMI Response in Fe4.3Co68.2Si12.5B15Amorphous Microwires

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The Asphaltene Coating Effect on GMI Response in Fe_4.3Co_68.2Si_12.5B₁₅Amorphous Microwires