Abstract
The structure and transport properties of physisorbed and chemisorbed CO2 in model polyamine liquids (hexamethylenediamine and diethylenetriamine) are studied via molecular dynamics simulations. Such systems are relevant to CO2 absorption processes where nonaqueous amines are used as absorbents (e.g., when impregnated or grafted onto mesoporous media or misted in the gas phase). It is shown that accounting for the ionic speciation resulting from CO2 chemisorption enabled us to capture the qualitative changes in extent of absorption and fluidity with time that are observed in thermogravimetric experiments. Simulations reveal that high enough concentration of reacted CO2 leads to strong intermolecular ionic interactions and the arrest of molecular translations. The transport properties obtained from the simulations of the ionic speciated mixtures are also used to construct an approximate continuum-level model for the CO2 absorption process that mimics thermogravimetric experiments.
Original language | English (US) |
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Pages (from-to) | 17603-17613 |
Number of pages | 11 |
Journal | ACS Applied Materials & Interfaces |
Volume | 7 |
Issue number | 32 |
DOIs | |
State | Published - Aug 5 2015 |
Externally published | Yes |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledged KAUST grant number(s): KUS-C1-018-02
Acknowledgements: This publication was based on work supported by Award No. KUS-C1-018-02, made by King Abdullah University of Science and Technology (KAUST). EPG gratefully acknowledges support from NPRP Grant #5-1437-1−243 from the Qatar National Research Fund. The authors are also grateful to computer cycles supplied by the Extreme Science and Engineering Discovery Environment (XSEDE) which is supported by National Science Foundation grant number OCI-1053575.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.