Structural parameters petroleum asphaltene

Microstructure. By using a group of structural parameters obtained through a number of physical methods (such as x-ray, NMR, MS, IR, VPO, DTA, densimetric methods, EM, and SAS) and chemical methods (such as oxidation, alkylation, and halogenation), the structure of petroleum asphaltene has been gradually revealed. As an example, the structural parameters of an asphaltene derived from a Laquinillas crude oil from Venezuela (API gravity 20°, Conradson carbon number 13.39, Miocene Age) are listed in Table I. An empirical formula can be deduced. 

Table I. Examples of the Structural Parameters for the Microstructure of a Petroleum-Derived Asphaltene...

Hydrocarbon Structures. Early postulates of asphaltene structure centered around a variety of polymer structures based on aromatic systems (36, 37). More recent information has related to the structural parameters and carbon skeleton of petroleum fractions, and asphaltenes structures have been derived from spectroscopic studies of asphaltenes isolated from various petroleum and bitumen (38-46). 

These NMR methods developed for dilute solutions of the intractable fractions of petroleum asphaltenes [75,91,92] have supported the high average mass measurements of asphaltenes by LD-MS through evaluation of average structural parameters from the NMR spectra. Briefly, for the sample mass data to match the measured... 

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