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Characterization of Athabasca asphaltenes separated physically and chemically using small-angle X-ray scattering

Athabasca asphaltenes were characterized using small-angle X-ray scattering (SAXS) with synchrotron radiation. Two methods were used to separate asphaltenes from Athabasca bitumen. Conventional chemical separation by precipitation with n-pentane, and physical separation realized by passing bitumen through a zirconia membrane with a 20 nm average pore size. The Athabasca permeates and chemically separated samples were dispersed in 1-methylnaphtalene and n-dodecane, with temperature and asphaltene concentration ranges of 50-310 C and 1-8 wt. %, respectively. Two approaches were also taken in the analysis of the SAXS emissions. A model-independent approach provided radii of gyration and scattering coefficients. A model-dependent fit provided size distributions for asphaltenes aggregates assuming that they are dense and spherical. Physically and chemically separated asphaltenes showed significant differences in nominal size and structure, and their structural properties exhibited different temperature dependencies. The results challenge the merits of using chemically separated asphaltene properties as a basis for asphaltene property prediction in crude oil/bitumen.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:AEU.10048/1496
Date11 1900
CreatorsAmundarain, Jesus
ContributorsShaw, John (Chemical and Materials Engineering), Dechaine, Greg (Chemical and Materials Engineering), Fenniri, Hicham (Chemistry), Shaw, John (Chemical and Materials Engineering)
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
Languageen_US
Detected LanguageEnglish
TypeThesis
Format3005391 bytes, application/pdf

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