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Diffusion of methane in supercritical carbon dioxide across the Widom line

Diffusion of methane diluted in supercritical carbon dioxide is studied by experiment and molecular simulation in the temperature range from 292.55 to 332.85 K along the isobars 9.0, 12.5 and 14.7 MPa. Measurements of the Fick diffusion coefficient are carried out with the Taylor dispersion techniqu...

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Autores principales: Guevara-Carrion, Gabriela, Ancherbak, Sergiy, Mialdun, Aliaksandr, Vrabec, Jadran, Shevtsova, Valentina
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6560060/
https://www.ncbi.nlm.nih.gov/pubmed/31186475
http://dx.doi.org/10.1038/s41598-019-44687-1
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author Guevara-Carrion, Gabriela
Ancherbak, Sergiy
Mialdun, Aliaksandr
Vrabec, Jadran
Shevtsova, Valentina
author_facet Guevara-Carrion, Gabriela
Ancherbak, Sergiy
Mialdun, Aliaksandr
Vrabec, Jadran
Shevtsova, Valentina
author_sort Guevara-Carrion, Gabriela
collection PubMed
description Diffusion of methane diluted in supercritical carbon dioxide is studied by experiment and molecular simulation in the temperature range from 292.55 to 332.85 K along the isobars 9.0, 12.5 and 14.7 MPa. Measurements of the Fick diffusion coefficient are carried out with the Taylor dispersion technique. Molecular dynamics simulation and the Green-Kubo formalism are employed to obtain Fick, Maxwell-Stefan and intradiffusion coefficients as well as shear viscosity. The obtained diffusion coefficients are on the order of 10(−8) m(2)/s. The composition, temperature and density dependence of diffusion is analyzed. The Fick diffusion coefficient of methane in carbon dioxide shows an anomaly in the near-critical region. This behavior can be attributed to the crossing of the so-called Widom line, where the supercritical fluid goes through a transition between liquid-like and gas-like states. Further, several classical equations are tested on their ability to predict this behavior and it is found that equations that explicitly include the density are better suited to predict the sharp variation of the diffusion coefficient near the critical region predicted by molecular simulation.
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spelling pubmed-65600602019-06-19 Diffusion of methane in supercritical carbon dioxide across the Widom line Guevara-Carrion, Gabriela Ancherbak, Sergiy Mialdun, Aliaksandr Vrabec, Jadran Shevtsova, Valentina Sci Rep Article Diffusion of methane diluted in supercritical carbon dioxide is studied by experiment and molecular simulation in the temperature range from 292.55 to 332.85 K along the isobars 9.0, 12.5 and 14.7 MPa. Measurements of the Fick diffusion coefficient are carried out with the Taylor dispersion technique. Molecular dynamics simulation and the Green-Kubo formalism are employed to obtain Fick, Maxwell-Stefan and intradiffusion coefficients as well as shear viscosity. The obtained diffusion coefficients are on the order of 10(−8) m(2)/s. The composition, temperature and density dependence of diffusion is analyzed. The Fick diffusion coefficient of methane in carbon dioxide shows an anomaly in the near-critical region. This behavior can be attributed to the crossing of the so-called Widom line, where the supercritical fluid goes through a transition between liquid-like and gas-like states. Further, several classical equations are tested on their ability to predict this behavior and it is found that equations that explicitly include the density are better suited to predict the sharp variation of the diffusion coefficient near the critical region predicted by molecular simulation. Nature Publishing Group UK 2019-06-11 /pmc/articles/PMC6560060/ /pubmed/31186475 http://dx.doi.org/10.1038/s41598-019-44687-1 Text en © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Guevara-Carrion, Gabriela
Ancherbak, Sergiy
Mialdun, Aliaksandr
Vrabec, Jadran
Shevtsova, Valentina
Diffusion of methane in supercritical carbon dioxide across the Widom line
title Diffusion of methane in supercritical carbon dioxide across the Widom line
title_full Diffusion of methane in supercritical carbon dioxide across the Widom line
title_fullStr Diffusion of methane in supercritical carbon dioxide across the Widom line
title_full_unstemmed Diffusion of methane in supercritical carbon dioxide across the Widom line
title_short Diffusion of methane in supercritical carbon dioxide across the Widom line
title_sort diffusion of methane in supercritical carbon dioxide across the widom line
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6560060/
https://www.ncbi.nlm.nih.gov/pubmed/31186475
http://dx.doi.org/10.1038/s41598-019-44687-1
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