Phan, A;
Schlösser, H;
Striolo, A;
(2021)
Molecular Mechanisms by which Tetrahydrofuran Affects CO₂ Hydrate Growth: Implications for Carbon Storage.
Chemical Engineering Journal
, 418
, Article 129423. 10.1016/j.cej.2021.129423.
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Abstract
Gas hydrates have attracted siginifcant fundamental and applied interests due to their important role in various technological and enviromental processes. More recently, gas hydrates have shown potential applications for greenhouse gas capture and storage. To facilitate the latter application, introducing chemical additives into clathrate hydrates could help to enhance hydrate formation/growth rates, provided the gas storage capacity is not reduced. Employing equilibrium molecular dynamics, we study the impact of tetrahydrofuran (THF) on the kinetics of carbon dioxide (CO₂) hydrate growth/dissociation and on the CO₂ storage capacity of hydrates. Our simulations reproduce experimental data for CO₂ and CO₂+THF hydrates at selected operating conditions. The simulated results confirm that THF in stoichiometric concentration does reduce CO₂ storage capacity. This is not only due to the shortage of CO₂ trapping in sII hydrate 5^{12} cages, but also because of the favored THF occupancy in hydrate cages due to preferential THF−water hydrogen bonds. An analysis of the dynamical properties for CO₂ and THF at the hydrate-liquid interface reveals that THF can expedite CO₂ diffusion yielding a shift in the conditions conducive to CO₂ hydrate growth and stability to lower pressures and higher temperatures compared to systems without THF. These simulation results augment literature experimental observations, as they provide needed insights into the molecular mechanisms that can be adjusted to achieve optimal CO₂ storage in hydrates.
| Type: | Article |
|---|---|
| Title: | Molecular Mechanisms by which Tetrahydrofuran Affects CO₂ Hydrate Growth: Implications for Carbon Storage |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.cej.2021.129423 |
| Publisher version: | https://doi.org/10.1016/j.cej.2021.129423 |
| Language: | English |
| Additional information: | © 2021 The Authors. Published by Elsevier B.V. under a Creative Commons license (https://creativecommons.org/licenses/by/4.0/). |
| Keywords: | Molecular dynamics, CO₂ diffusion, hydrate thickness, CO₂ gas uptake |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Chemical Engineering |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10125176 |
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