Single-core PAHs in petroleum- and coal-derived asphaltenes: size and distribution from solid-state NMR spectroscopy and optical absorption measurements

Majumdar, R. Dutta; Bake, K. D.; Ratna, Y.; Pomerantz, A. E.; Mullins, O. C.; Gerken, Michael; Hazendonk, Paul

Single-core PAHs in petroleum- and coal-derived asphaltenes: size and distribution from solid-state NMR spectroscopy and optical absorption measurements

dc.contributor.author	Majumdar, R. Dutta
dc.contributor.author	Bake, K. D.
dc.contributor.author	Ratna, Y.
dc.contributor.author	Pomerantz, A. E.
dc.contributor.author	Mullins, O. C.
dc.contributor.author	Gerken, Michael
dc.contributor.author	Hazendonk, Paul
dc.date.accessioned	2021-08-04T21:07:26Z
dc.date.available	2021-08-04T21:07:26Z
dc.date.issued	2016
dc.description	Accepted author manuscript	en_US
dc.description.abstract	Using solid-state 13C NMR spectroscopy of two different asphaltenes, one derived from petroleum and the other from coal liquids, it was shown that the asphaltene molecular architecture consists of a spectrum of sizes, ranging from smaller polyaromatic hydrocarbons (PAHs; <5 condensed rings) to much larger ones (>9 condensed rings), but their distribution varies between the two. It is shown that smaller PAHs are likely more abundant in the coal-derived asphaltenes, while the largest PAH cores of the two different asphaltenes are similar in size. These observations are reinforced by optical absorption. The coal-derived asphaltenes were found to contain a small fraction of archipelago-type structures, where a small PAH is tethered to the larger PAH core via an aryl linkage, which are less evident, and likely less abundant, in the petroleum asphaltenes. An important difference between the two asphaltenes lies in their alkyl fraction, with the petroleum asphaltenes possessing significantly longer and more mobile alkyl side chains, on average ∼7 carbons long, as opposed to an average chain length of ∼3–4 in the coal asphaltenes. The petroleum asphaltenes also possess a larger fraction of alicyclics. The longer length increases the propensity of the petroleum asphaltene alkyl side chains to intercalate between the aromatic rings of adjacent asphaltene aggregates, which is not observed in coal-derived asphaltenes. This work demonstrates the utility of combining cross-polarization dynamics and directly polarized 13C solid-state NMR spectroscopy in studying asphaltenes, while adding to the body of evidence supporting the single-core model of asphaltenes, which appears to be the dominant structural motif for this fraction of petroleum.	en_US
dc.description.peer-review	Yes	en_US
dc.identifier.citation	Majumdar, R. D., Bake, K. D., Ratna, Y., Pomerantz, A. E., Mullins, O. C., Gerken, M., & Hazendon, P. (2016). Single-core PAHs in petroleum- and coal-derived asphaltenes: Size and distribution from solid-state NMR spectroscopy and optical absorption measurements, 30(9), 6892-6906. https://doi.org/10.1021/acs.energyfuels.5b02815	en_US
dc.identifier.uri	https://hdl.handle.net/10133/5985
dc.language.iso	en_US	en_US
dc.publisher	American Chemical Society	en_US
dc.publisher.department	Department of Chemistry and Biochemistry	en_US
dc.publisher.faculty	Arts and Science	en_US
dc.publisher.institution	Canadian Centre for Research in Advanced Fluorine Technologies	en_US
dc.publisher.institution	Schlumberger-Doll Research	en_US
dc.publisher.institution	University of Lethbridge	en_US
dc.publisher.url	https://doi.org/10.1021/acs.energyfuels.5b02815	en_US
dc.subject	Asphaltenes
dc.subject	PAHs
dc.subject.lcsh	Asphaltene
dc.subject.lcsh	Hydrocarbons
dc.subject.lcsh	Carbon
dc.subject.lcsh	Aromatic compounds
dc.subject.lcsh	Quantum mechanics
dc.subject.lcsh	Nuclear magnetic resonance spectroscopy
dc.title	Single-core PAHs in petroleum- and coal-derived asphaltenes: size and distribution from solid-state NMR spectroscopy and optical absorption measurements	en_US
dc.type	Article	en_US