Chemical structure of tar-sand bitumens by 13C and 1H n.m.r. spectroscopic methods

Suzuki, Toshimitsu; Itoh, Mai; Takegami, Yoshinobu; Watanabe, Yoshihisa

doi:10.1016/0016-2361(82)90062-x

“…Based on the foregoing simple model, the observed PFGSE diffusion data reveal multimers, containing from several monomers at low asphaltene concentrations up to perhaps hundreds in the concentrated solutions. These results support the view that AOSA forms molecular association complexes, even at 1 wt% concentration in benzene [1]. In fact, Xu et al have characterized, by small angle X-ray scattering, 5-15% colloidal dispersions of Athabasca asphaltene in toluene at room temperature to contain polydispersed spherical particles of average radius 33 Å , though the distribution is skewed and a small proportion form larger aggregates [52].…”

Section: Self-diffusion Coefficient Measurementssupporting

confidence: 79%

“…The D(fast) values of asphaltene solutions are slightly lower than those of pure chloroform, perhaps because of solute-solvent deuterium/hydrogen bonding. Although the small molecules which comprise gas and naphtha fractions can contribute to the proton spin-echo signal, they are less than 3% by weight of Athabasca oil sand bitumen [1], and would probably escape during the thermal oxidation process at 130ЊCand not account for the similar D(fast) values of AOSA and oxidized AOSA solutions ( Table 3). The remaining slow component is thus due to the diffusion of asphaltene molecules and any multimolecular aggregates.…”

Section: Self-diffusion Coefficient Measurementsmentioning

confidence: 99%

The low temperature oxidation of Athabasca oil sand asphaltene observed from 13C, 19F, and pulsed field gradient spin-echo proton n.m.r. spectra

Desando

¹

,

Lahajnar

²

,

Ripmeester

³

et al. 1999

Fuel

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The low temperature oxidation of Athabasca oil sand asphaltene observed from 13C, 19F and pulsed field gradient spin-echo proton n.m.r. spectra Desando, Michael A.; Lahajnar, Gojmir; Ripmeester, John A.; Zupancic, Ivan AbstractCarbon-13 and fluorine-19 nuclear magnetic resonance spectra of chemically derivatized, by phase transfer methylation and trifluoroacetylation, Athabasca oil sand asphaltene, reveal a broad site distribution of different types of hydroxyl-containing functional groups, viz., carboxylic acids, phenols, and alcohols. The low temperature air oxidation of asphaltene, at ca. 130ЊC for 3 days, generates a few additional carboxyl and phenolic groups. These results are consistent with a mechanism in which diaryl methylene and ether moieties react with oxygen. Self-diffusion coefficients, from the pulsed field gradient spin-echo proton magnetic resonance technique, suggest that low temperature oxidation does not appreciably alter the average particle size and diffusion properties of asphaltene in deuterochloroform. ᭧

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“…Asphaltene is a multicomponent, high molecular weight fraction of oil or tar sand bitumen [1][2][3]. Although asphaltene is known to contain aromatic and aliphatic moieties there is less certainty on the types and numbers of acidic groups, e.g., carboxylic acids, phenols, and alcohols.…”

Section: Introductionmentioning

confidence: 99%

“…10 2 -10 5 amu [1,2], and 6^2 oxygen atoms in an average molecule of 3000 amu [1,2,18,22]. In some polar molecules oxygen may be predominantly in OH and COOH, while in others it is absent, and in some cases is nonacidic, e.g.…”

mentioning

confidence: 99%

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99/02454 The low temperature oxidation of Athabasca oil sand asphaltene observed from 13C, 19F, and pulsed field gradient spin-echo proton n.m.r. spectra

1999

Fuel and Energy Abstracts

0

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The low temperature oxidation of Athabasca oil sand asphaltene observed from 13C, 19F and pulsed field gradient spin-echo proton n.m.r. spectra Desando, Michael A.; Lahajnar, Gojmir; Ripmeester, John A.; Zupancic, Ivan AbstractCarbon-13 and fluorine-19 nuclear magnetic resonance spectra of chemically derivatized, by phase transfer methylation and trifluoroacetylation, Athabasca oil sand asphaltene, reveal a broad site distribution of different types of hydroxyl-containing functional groups, viz., carboxylic acids, phenols, and alcohols. The low temperature air oxidation of asphaltene, at ca. 130ЊC for 3 days, generates a few additional carboxyl and phenolic groups. These results are consistent with a mechanism in which diaryl methylene and ether moieties react with oxygen. Self-diffusion coefficients, from the pulsed field gradient spin-echo proton magnetic resonance technique, suggest that low temperature oxidation does not appreciably alter the average particle size and diffusion properties of asphaltene in deuterochloroform. ᭧

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Solid contents of palm‐based biofuel mixtures with respect to storage and handling

Chong¹,

Choo²,

Wahid³

2007

Euro J Lipid Sci & Tech

0

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The solid content (SC) of biofuel mixtures obtained from mixing crude palm oil (CPO) with medium fuel oil (MFO), and refined palm oil (RPO) with petroleum diesel (PD), was investigated. The SC of these mixtures will impact on their applications, storage and handling. The concentrations of CPO and RPO in the investigated mixtures ranged from 5 to 90% for the CPO-MFO system and from 0 to 10% for the RPO-PD system. For CPO/MFO mixtures, their SC exhibited eutectic behavior over the temperature range measured (5-20 7C). Eutectic minima were observed in the 80-90% CPO concentration range for all temperatures. These eutectic minima are due to dilution effects and the formation of van der Waals hydrogen bonds between the asphaltenes in MFO and the triacylglycerols. RPO/PD mixtures did not show any eutectic behavior. The SC for the RPO/PD mixtures were observed to be below 4% at 5 7C after 24 h of tempering and 0% at 15 7C over the same tempering period. When semi-solid, ambient PO is used as a biofuel, heating is required to liquify it for ease of handling. When mixed with petroleum-based fuels in the correct proportion, present handling and storage equipment and facilities are adequate for handling these mixtures.

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Chemical structure of tar-sand bitumens by 13C and 1H n.m.r. spectroscopic methods

Cited by 122 publications

References 17 publications

The low temperature oxidation of Athabasca oil sand asphaltene observed from 13C, 19F, and pulsed field gradient spin-echo proton n.m.r. spectra

The low temperature oxidation of Athabasca oil sand asphaltene observed from 13C, 19F, and pulsed field gradient spin-echo proton n.m.r. spectra

99/02454 The low temperature oxidation of Athabasca oil sand asphaltene observed from 13C, 19F, and pulsed field gradient spin-echo proton n.m.r. spectra

Solid contents of palm‐based biofuel mixtures with respect to storage and handling

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