Effects of chemical potential differences on methane hydrate formation kinetics
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Published version
Author(s)
Bian, Hao
Ai, Lu
Heng, Jerry YY
Maitland, Geoffrey C
Hellgardt, Klaus
Type
Journal Article
Abstract
To underpin the increasing interest in practical applications of gas hydrates, for gas storage and separation for instance, the formation and growth of hydrates at liquid-gas interfaces are of fundamental importance. Although the thermodynamics of hydrate formation has been widely studied and is well understood, the kinetics of these processes is not well characterised. In this work, a high-pressure, low-temperature stirred reactor was used to conduct hydrate formation kinetic studies in a temperature range from 276.5 to 283.5 K and a pressure range from 5 to 10.5 MPa, with a special focus on 1) the impact of agitation conditions on the available water-gas interfacial surface area for mass transfer and growth rate during hydrate formation, and 2) the effect of the chemical potential driving force on the formation rate. Five hydrate growth regimes were identified, with varying degrees of gas mass transfer control across the gas-water interface depending on the extent to which hydrate layers built up at this interface, gas needed to move through solid hydrate layers, and the extent to which the gas was entrained within the water phase. The formation rate in the initial linear growth regime, before the onset of solid hydrate gas mass transfer effects, was found to depend in an essentially exponential manner on the chemical potential difference from the equilibrium state. Semi-empirical models related to Arrhenius-type kinetic models were used to correlate the data, the best of which reproduced the formation rates from the chemical potential differences to within ± 5 %. The approach has general applicability to help determine the balance between kinetic and thermodynamic factors in identifying the optimum pressure-temperature conditions for processes for gas storage, gas separation and other hydrate applications.
Date Issued
2023-01
Date Acceptance
2022-09-03
Citation
Chemical Engineering Journal, 2023, 452, pp.1-11
ISSN
1385-8947
Publisher
Elsevier BV
Start Page
1
End Page
11
Journal / Book Title
Chemical Engineering Journal
Volume
452
Copyright Statement
© 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/bync/4.0/).
License URL
Sponsor
Commonwealth Scientific and Industrial Research Organisation
Identifier
https://www.sciencedirect.com/science/article/pii/S1385894722045636?via%3Dihub
Grant Number
N/A
Subjects
Chemical Engineering
0904 Chemical Engineering
0905 Civil Engineering
0907 Environmental Engineering
Publication Status
Published
Article Number
139084
Date Publish Online
2022-09-18