Routine method for quantitative 13C n.m.r. spectra editing and providing structural patternsApplication to every kind of petroleum fractions including residues and asphaltenes

Bouquet, Michel; Bailleul, A.

doi:10.1016/0016-2361(86)90236-x

Cited by 29 publications

(8 citation statements)

References 9 publications

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“…Based on the method proposed by Bouquet and Bailleul [61], it is possible to determine the proportion of the different types of aromatics carbons: CH and quaternary C aro q , including the quaternary condensed C aro qcond or quaternary substituted C aro qsub and the fraction of the different aliphatic carbons CH 3 , CH 2 , CH and the quaternary aliphatic C q sat . See Fig.…”

Section: Effluent Analysismentioning

confidence: 99%

Effect of acidity, hydrogenating phases and texture properties of catalysts on the evolution of asphaltenes structures during reside hydroconversion

2015

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Section: Effluent Analysismentioning

confidence: 99%

Effect of acidity, hydrogenating phases and texture properties of catalysts on the evolution of asphaltenes structures during reside hydroconversion

2015

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“…The procedures originally proposed by Hasan et al and by Siddiqui and Ali to characterize asphalts have been used practically unmodified since their original publications, despite advances in NMR as analytical technique and the improvements in the technologies and methods to characterize such materials. ,,,− In this work, both NMR spectra of the same sample (P1, P2 or P3), were processed from its FID, according to indications of Avella and Fierro , and the other two methods. Results were compared correspondently (Tables and ).…”

Section: Results and Discussionmentioning

confidence: 99%

Structural Characterization of Unfractionated Asphalts by¹H NMR and¹³C NMR

2016

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An improved methodology for the structural characterization of heavy fractions of petroleum by hydrogen-1 and carbon-13 nuclear magnetic resonance was applied to three fresh and unfractionated asphalts in solution. The results were compared with those generated by two other known characterization methods applied to the same NMR spectra. The comparison revealed inconsistencies in the traditional methods for the structural characterization of this type of materials. The improved methodology can be applied to unfractionated samples, and it provides a more detailed structural characterization of the asphalts than previously obtained. The new method provides a better correlation between physicochemical properties and the chemical structure of the complex mixtures of hydrocarbons.

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“…13 C nuclear magnetic resonance spectroscopy has also become a useful, nondestructive tool in the analysis of crude oils and petroleum products. − This technique is very attractive in that it provides an accurate value of “aromaticity” or aromatic carbon content as a fraction of the total carbon and consequently affords an excellent characterization of complex, multicomponent petroleum fractions. , In 13 C NMR spectroscopy, the carbon types are observed directly and, under appropriate conditions, can be readily quantified. There are two inherent problems in 13 C spectra which must be taken into account to ensure the quantitative reliability of the data: (1) the great difference in relaxation times for different molecules observed in the same crude oil fraction and (2) the extensive variations in the nuclear Overhauser enhancement (NOE) parameter.…”

Section: Introductionmentioning

confidence: 99%

“…13 C nuclear magnetic resonance spectroscopy has also become a useful, nondestructive tool in the analysis of crude oils and petroleum products. [45][46][47] This technique is very attractive in that it provides an accurate value of "aromaticity" or aromatic carbon content as a fraction of the total carbon and consequently affords an excellent characterization of complex, multicomponent petroleum fractions. 48,49 In 13 C NMR spectroscopy, the carbon types are observed directly and, under appropriate conditions, can be readily quantified.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Precipitation and Extrography in the Fractionation of Crude Oil Residua

McLean

Kilpatrick

1997

Energy Fuels

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Four different crude oilsArab Heavy (AH), Arab Berri (AB), Alaskan North Slope (ANS), and San Joaquin Valley (SJV)were characterized by separating the crudes into compound classes by two different fractionation methodsextrography (ext) and asphaltene precipitation followed by extrographic isolation of the resins (ppt + ext). The fractions derived from these two methods of separation were characterized and compared in order to determine the most complete and discriminating compositional analysis for subsequent use in studies concerning the stability of emulsions or sludges which are produced by these crudes in refinery processing. The resin and asphaltene fractions are of primary interest due to their polar, surface-active nature, the central role these fractions play in stabilizing emulsions and sludges, and their resulting influence on crude processability. Preparatory-scale separations were developed and utilized to provide sufficient amounts of the polar fractions of these crudes for further studies. The H/C ratio and concentrations of S, N, and O as well as V and Ni contents were determined for each of the crudes and their respective fractions. The results of this investigation also provided useful information regarding the H-bonding capacity (as gauged by the functional group types and content) and aromaticity of the polar fractions of these particular crude oils. The polar functional groups and carbon types were identified and quantitated by FTIR and 13C NMR spectroscopy. FTIR analysis also provided an indirect measure of the polarity of substituent groups attached to the aromatic core of these molecules when comparing the results of the integration of the aromatic CC stretch with the aromaticity as measured by 13C NMR analysis. Both the H-bonding capacity and the aromaticity are considered to play a central role in determining the solubility of asphaltenes in the crude medium which in turn has a significant effect on the emulsifying potential of the crude oil. In the comparison of the two fractionation methods, the resin and total asphaltene yields were very similar for most of the crude types; however, the characteristics of these polar fractions varied considerably in all the crudes depending upon the method used to isolate them. There was strong evidence to support the prevailing sentiment that the fraction which is coined “asphaltenes” is greatly influenced and defined by the very method utilized to isolate this fraction. When considering and analyzing the characteristics of the polar materials in their totality (i.e., resins + asphaltenes), these materials were very similar in nature regardless of the fractionation method used to isolate them. However, irreversible adsorption of asphaltenic components (up to ∼0.8 wt % of whole crude) on the silica gel does occur when employing the extrographic technique. Thus, the ppt + ext fractionation method appears to be the simplest and most robust method to provide further understanding of the mechanisms which govern the stability of emulsions produced from ...

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Routine method for quantitative 13C n.m.r. spectra editing and providing structural patternsApplication to every kind of petroleum fractions including residues and asphaltenes

Cited by 29 publications

References 9 publications

Effect of acidity, hydrogenating phases and texture properties of catalysts on the evolution of asphaltenes structures during reside hydroconversion

Effect of acidity, hydrogenating phases and texture properties of catalysts on the evolution of asphaltenes structures during reside hydroconversion

Structural Characterization of Unfractionated Asphalts by¹H NMR and¹³C NMR

Comparison of Precipitation and Extrography in the Fractionation of Crude Oil Residua

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Routine method for quantitative 13C n.m.r. spectra editing and providing structural patternsApplication to every kind of petroleum fractions including residues and asphaltenes

Cited by 29 publications

References 9 publications

Effect of acidity, hydrogenating phases and texture properties of catalysts on the evolution of asphaltenes structures during reside hydroconversion

Effect of acidity, hydrogenating phases and texture properties of catalysts on the evolution of asphaltenes structures during reside hydroconversion

Structural Characterization of Unfractionated Asphalts by1H NMR and13C NMR

Comparison of Precipitation and Extrography in the Fractionation of Crude Oil Residua

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Structural Characterization of Unfractionated Asphalts by¹H NMR and¹³C NMR