On the formation and properties of asphaltene nanoaggregates and clusters by DC-conductivity and centrifugation

Goual, Lamia; Sedghi, Mohammad; Zeng, Huang; Mostowfi, Farshid; McFarlane, Richard; Mullins, Oliver C.

doi:10.1016/j.fuel.2011.02.025

Cited by 128 publications

(136 citation statements)

References 65 publications

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“…Above the CCC, nanoaggregates stick to each other upon collision and form clusters. Experimental works have shown that the CCC is round 2 g L −1 to 5 g L −1 for asphaltene/toluene solutions subject to heptane addition [36,37]. From Fig.…”

Section: The Asphaltene-heptane Systemmentioning

confidence: 90%

The aggregation and diffusion of asphaltenes studied by GPU-accelerated dissipative particle dynamics

Wang

Wen

2014

Computer Physics Communications

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Section: The Asphaltene-heptane Systemmentioning

confidence: 90%

The aggregation and diffusion of asphaltenes studied by GPU-accelerated dissipative particle dynamics

Wang

Wen

2014

Computer Physics Communications

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“…15,16 These fundamentals must hold true for resins as well. Nonetheless, the limit concentration at which either asphaltenes or resins start forming aggregates, or clusters, was not investigated in our experimental studies.…”

Section: Molecular Weight Of Asphaltene and Resin Nanoaggregatesmentioning

confidence: 99%

A study of asphaltene-resin interactions

Marques¹,

Pereira²,

Bueno³

et al. 2012

J. Braz. Chem. Soc.

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Foi realizado um estudo para investigar a interação entre asfaltenos (em soluções de tolueno) e resinas (em soluções de n-heptano). Para entender melhor o tipo de interação entre essas frações, quantificou-se o consumo de resina quando asfaltenos (dissolvidos em tolueno) foram precipitados com uma solução de n-heptano contendo resina. Os resultados indicaram que a precipitação de asfaltenos ocorre juntamente com a redução na concentração de resina. Os perfis das isotermas de ligação indicaram que a saturação ocorreu em um caso, em quanto que o efeito cooperativo com posterior platô inicial foi observado para duas outras amostras. Estes resultados confirmaram a hipótese de que resinas podem adsorver em asfaltenos, mas não podem evitar floculação e precipitação de asfaltenos. Além disso, resultados de microcalorimetria sugeriram que a resina e asfalteno interagem por forças fracas de van der Waals. Estes resultados estão em contraste com a escola de pensamento predominante desde a década de 1940 que advoga que as resinas podem peptizar e estabilizar asfaltenos.A study was carried out to investigate the interaction between asphaltenes (in toluene solutions) and resins (in n-heptane solutions). To better understand the type of interaction between these fractions, it was quantified the resin uptake when asphaltenes (dissolved in toluene) were precipitated by a resin-containing n-heptane solution. These results indicated the asphaltene precipitation occurs together with a reduction in the resin concentration. The binding isotherm profiles indicated that saturation occurred in one case, while collective association following an initial plateau was observed for the other two samples. These results confirmed the hypothesis that resins can adsorb on asphaltenes but cannot prevent asphaltenes from flocculating and precipitating. Furthermore, microcalorimetric results suggested that the resin and asphaltene interact by weak van der Waals forces. These results are in stark contrast with the school of thought prevalent since the 1940s that resins can peptize and stabilize asphaltenes.

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“…Recent studies refuting the colloidal model are discussed by Punnapala and Vargas [65], while micellar models of asphaltene aggregation have been suggested as being inadequate from a lack of evidence for a critical micelle concentration, or concentration at which the asphaltenes start to associate, using isothermal titration calorimetry [66]. However, whilst this approach failed to detect nanoaggregate formation at low asphaltene concentrations, the finding is consistent with the dominant entropic contribution to the process [67], and a number of techniques have indeed provided evidence for nanoaggregate formation in asphaltene systems, including high-Q ultrasonics [68], NMR spectroscopy [69], electrical conductivity [67], small-angle neutron and x-ray scattering [70], mass spectrometry [70], centrifugation [67], and the analysis of gravity gradients in oilfields [71][72][73].…”

Section: Introductionmentioning

confidence: 94%