Investigation of the fluid behavior of asphaltenes and toluene insolubles by high-temperature proton nuclear magnetic resonance and rheometry and their application to visbreaking

The fluid behavior of asphaltenes at elevated temperatures impacts coke formation in a number of hydrocarbon conversion processes, including visbreaking and delayed coking. In this study, the asphaltenes from a number of sources, namely, a vacuum residue, a petroleum source rock (Kimmeridge clay) bi...

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Main Authors: Castro-Díaz, M., Uguna, Clement N., Cheeseman, Barry, Barker, James, Snape, C.E.
Format: Article
Published: American Chemical Society 2016
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Online Access:https://eprints.nottingham.ac.uk/40096/
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author Castro-Díaz, M.
Uguna, Clement N.
Cheeseman, Barry
Barker, James
Snape, C.E.
author_facet Castro-Díaz, M.
Uguna, Clement N.
Cheeseman, Barry
Barker, James
Snape, C.E.
author_sort Castro-Díaz, M.
building Nottingham Research Data Repository
collection Online Access
description The fluid behavior of asphaltenes at elevated temperatures impacts coke formation in a number of hydrocarbon conversion processes, including visbreaking and delayed coking. In this study, the asphaltenes from a number of sources, namely, a vacuum residue, a petroleum source rock (Kimmeridge clay) bitumen obtained by hydrous pyrolysis, and bitumen products from a sub-bituminous coal and pine wood obtained by thermolytic solvent extraction using tetralin, have been characterized using high-temperature proton nuclear magnetic resonance (1H NMR), and the results correlated with those from small-amplitude oscillatory shear rheometry. Further for comparison, the coke (toluene insolubles) obtained from visbreaking the vacuum residue was also characterized. All of the asphaltenes became completely fluid by 300 °C, with hydrogen being completely mobile with coke formation, identified as a solid phase, not occurring to a significant extent until 450 °C. Extremely good agreement was obtained between high-temperature 1H NMR and rheometry results, which confirmed that the asphaltenes were highly fluid from 300 °C, with initial signs of resolidification being observed at temperatures of around 450 °C. During softening, extremely good correlations between fluid hydrogen and phase angle were obtained as the asphaltenes softened. The toluene insolubles however did contain some fluid material; thus, it cannot be regarded as strictly solid coke, but clearly, with increasing temperature, the fluid material did convert to coke. Under actual process conditions, this fluid material could be responsible for coke adhering to reactor surfaces.
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spelling nottingham-400962020-05-04T17:41:21Z https://eprints.nottingham.ac.uk/40096/ Investigation of the fluid behavior of asphaltenes and toluene insolubles by high-temperature proton nuclear magnetic resonance and rheometry and their application to visbreaking Castro-Díaz, M. Uguna, Clement N. Cheeseman, Barry Barker, James Snape, C.E. The fluid behavior of asphaltenes at elevated temperatures impacts coke formation in a number of hydrocarbon conversion processes, including visbreaking and delayed coking. In this study, the asphaltenes from a number of sources, namely, a vacuum residue, a petroleum source rock (Kimmeridge clay) bitumen obtained by hydrous pyrolysis, and bitumen products from a sub-bituminous coal and pine wood obtained by thermolytic solvent extraction using tetralin, have been characterized using high-temperature proton nuclear magnetic resonance (1H NMR), and the results correlated with those from small-amplitude oscillatory shear rheometry. Further for comparison, the coke (toluene insolubles) obtained from visbreaking the vacuum residue was also characterized. All of the asphaltenes became completely fluid by 300 °C, with hydrogen being completely mobile with coke formation, identified as a solid phase, not occurring to a significant extent until 450 °C. Extremely good agreement was obtained between high-temperature 1H NMR and rheometry results, which confirmed that the asphaltenes were highly fluid from 300 °C, with initial signs of resolidification being observed at temperatures of around 450 °C. During softening, extremely good correlations between fluid hydrogen and phase angle were obtained as the asphaltenes softened. The toluene insolubles however did contain some fluid material; thus, it cannot be regarded as strictly solid coke, but clearly, with increasing temperature, the fluid material did convert to coke. Under actual process conditions, this fluid material could be responsible for coke adhering to reactor surfaces. American Chemical Society 2016-03-17 Article PeerReviewed Castro-Díaz, M., Uguna, Clement N., Cheeseman, Barry, Barker, James and Snape, C.E. (2016) Investigation of the fluid behavior of asphaltenes and toluene insolubles by high-temperature proton nuclear magnetic resonance and rheometry and their application to visbreaking. Energy and Fuels, 30 (3). pp. 2012-2020. ISSN 1520-5029 Asphaltenes Visbreaking Bitumen Coal Biomass High temperature 1H NMR Small-amplitude oscillatory shear rheometry http://dx.doi.org/10.1021/acs.energyfuels.5b02675 doi:10.1021/acs.energyfuels.5b02675 doi:10.1021/acs.energyfuels.5b02675
spellingShingle Asphaltenes
Visbreaking
Bitumen
Coal
Biomass
High temperature 1H NMR
Small-amplitude oscillatory shear rheometry
Castro-Díaz, M.
Uguna, Clement N.
Cheeseman, Barry
Barker, James
Snape, C.E.
Investigation of the fluid behavior of asphaltenes and toluene insolubles by high-temperature proton nuclear magnetic resonance and rheometry and their application to visbreaking
title Investigation of the fluid behavior of asphaltenes and toluene insolubles by high-temperature proton nuclear magnetic resonance and rheometry and their application to visbreaking
title_full Investigation of the fluid behavior of asphaltenes and toluene insolubles by high-temperature proton nuclear magnetic resonance and rheometry and their application to visbreaking
title_fullStr Investigation of the fluid behavior of asphaltenes and toluene insolubles by high-temperature proton nuclear magnetic resonance and rheometry and their application to visbreaking
title_full_unstemmed Investigation of the fluid behavior of asphaltenes and toluene insolubles by high-temperature proton nuclear magnetic resonance and rheometry and their application to visbreaking
title_short Investigation of the fluid behavior of asphaltenes and toluene insolubles by high-temperature proton nuclear magnetic resonance and rheometry and their application to visbreaking
title_sort investigation of the fluid behavior of asphaltenes and toluene insolubles by high-temperature proton nuclear magnetic resonance and rheometry and their application to visbreaking
topic Asphaltenes
Visbreaking
Bitumen
Coal
Biomass
High temperature 1H NMR
Small-amplitude oscillatory shear rheometry
url https://eprints.nottingham.ac.uk/40096/
https://eprints.nottingham.ac.uk/40096/
https://eprints.nottingham.ac.uk/40096/