CATEGORY: HEAVY CRUDE
Energy Fuels, Just Accepted Manuscript, DOI:
10.1021/ef3018578, Publication Date (Web): January 16, 2013
Heavy Petroleum Composition 3. Asphaltene
Aggregation
Amy M McKenna , Lynda J. Donald , Jade E.
Fitzsimmons , Priyanka Juyal , Victor Spicer , Kenneth G. Standing , Alan G.
Marshall , and Ryan Patrick Rodgers
Abstract
Molecular characterization of asphaltenes by
conventional analytical techniques is difficult because of their compositional
complexity, high heteroatom content, and asphaltene aggregate formation at low
concentration. Consequently, most common characterization techniques rely on
bulk properties or solution-phase behavior . The Boduszynski model proposes a
continuous progression in petroleum composition as a function of atmospheric
equivalent boiling point.
Exhaustive detailed compositional analysis of
petroleum distillates validates the continuum model. However, available
compositional data from asphaltene fractions only indirectly supports the
extension of the continuum model into the nondistillables.
Asphaltenes, defined by their insolubility in alkane solvents, accumulate in
high boiling fractions and form stable aggregate structures at low (ppb)
concentrations, far below the concentration required for most mass analyzers. Authors
describe present direct mass spectral detection of stable asphaltene aggregates
at lower concentration than previously published, and observe the onset of
asphaltene nanoaggregate formation by time-of-flight (TOF) mass spectrometry. They
conclude that a fraction of asphaltenes must be present as nanoaggregates (not
monomers) in all atmospheric pressure and laser-based ionization methods.
Full Text Source (Subscription or Fee): http://pubs.acs.org/doi/abs/10.1021/ef3018578
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