The low temperature oxidation of Athabasca oil sand asphaltene observed from 13C, 19F and pulsed field gradient spin-echo proton n.m.r. spectra

Carbon-13 and fluorine-19 nuclear magnetic resonance spectra of chemically derivatized, by phase transfer methylation and trifluoroacetylation, Athabasca oil sand asphaltene, reveal a broad site distribution of different types of hydroxyl-containing functional groups, viz., carboxylic acids, phenols, and alcohols. The low temperature air oxidation of asphaltene, at ca. 1308C for 3 days, generates a few additional carboxyl and phenolic groups. These results are consistent with a mechanism in which diaryl methylene and ether moieties react with oxygen. Self-diffusion coefficients, from the pulsed field gradient spin-echo proton magnetic resonance technique, suggest that low temperature oxidation does not appreciably alter the average particle size and diffusion properties of asphaltene in deuterochloroform.Peer reviewed: YesNRC publication: Ye