Application of the shrinking-core model to the kinetics of repeated formation of methane hydrates in a system of mixed dry-water and porous hydrogel particulates

Mixed dry-water (DW) droplets and porous hydrogel (HYD) microspheres have been investigated for applications in reversible methane storage in the form of clathrates. The process of the methane hydrates formation in the presence of these particles was found to be complex. In this work, a modified shr...

Full description

Bibliographic Details
Main Authors: Shi, B., Fan, S., Lou, Xia
Format: Journal Article
Published: Pergamon 2014
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/38895
_version_ 1848755443304759296
author Shi, B.
Fan, S.
Lou, Xia
author_facet Shi, B.
Fan, S.
Lou, Xia
author_sort Shi, B.
building Curtin Institutional Repository
collection Online Access
description Mixed dry-water (DW) droplets and porous hydrogel (HYD) microspheres have been investigated for applications in reversible methane storage in the form of clathrates. The process of the methane hydrates formation in the presence of these particles was found to be complex. In this work, a modified shrinking-core model was used to simulate the process and to extract the diffusivity and the adsorption rate constant of methane based on the experimental data. The results indicated that the formation of methane hydrates in the mixed particulate systems was affected by water molecules from three different sources: the DW droplets, the HYD particles and the free water (FW) present in the system. The extracted value of initial methane diffusivity, Df0,DW (1.35×10−7–0.99×10−7 m2/s) for DW droplets, and Df0,HYD (1.59×10−7–5.24×10−7 m2/s) for HYD particles, are three orders of magnitude greater than that of bulk water (5×10−12 to 5×10−10 m2/s). The adsorption rate constant of methane, K⁎HYD (0.55×10−5–5.81×10−5 mol/m2 s MPa) of HYD particles, and K⁎DW (5.49×10−6–6.05×10−6 mol/m2 s MPa) of DW droplets, also are greater than the reported value of stirred bulk water (5.5×10−6–6.5×10−6 mol/m2 s MPa). The K⁎HYD is 10 times that of K⁎DW when the hydrogel particles are saturated, indicating a favourable design of the scaffold for methane hydrates formation. The results also demonstrated a higher and more stable water conversion yield (90%) in HYD particles, echoing the improved hydrates formation kinetics and better reversibility. The compromised gas capacity in the mixed system was likely due to the presence of a relatively higher volume of FW, which should be prevented in the future design and development of scaffolding materials for clathrates formation.
first_indexed 2025-11-14T08:56:23Z
format Journal Article
id curtin-20.500.11937-38895
institution Curtin University Malaysia
institution_category Local University
last_indexed 2025-11-14T08:56:23Z
publishDate 2014
publisher Pergamon
recordtype eprints
repository_type Digital Repository
spelling curtin-20.500.11937-388952017-09-13T14:22:14Z Application of the shrinking-core model to the kinetics of repeated formation of methane hydrates in a system of mixed dry-water and porous hydrogel particulates Shi, B. Fan, S. Lou, Xia Methane diffusivity Methane hydrates formation Kinetics Porous hydrogel Reversible methane storage Shrinking-core model Mixed dry-water (DW) droplets and porous hydrogel (HYD) microspheres have been investigated for applications in reversible methane storage in the form of clathrates. The process of the methane hydrates formation in the presence of these particles was found to be complex. In this work, a modified shrinking-core model was used to simulate the process and to extract the diffusivity and the adsorption rate constant of methane based on the experimental data. The results indicated that the formation of methane hydrates in the mixed particulate systems was affected by water molecules from three different sources: the DW droplets, the HYD particles and the free water (FW) present in the system. The extracted value of initial methane diffusivity, Df0,DW (1.35×10−7–0.99×10−7 m2/s) for DW droplets, and Df0,HYD (1.59×10−7–5.24×10−7 m2/s) for HYD particles, are three orders of magnitude greater than that of bulk water (5×10−12 to 5×10−10 m2/s). The adsorption rate constant of methane, K⁎HYD (0.55×10−5–5.81×10−5 mol/m2 s MPa) of HYD particles, and K⁎DW (5.49×10−6–6.05×10−6 mol/m2 s MPa) of DW droplets, also are greater than the reported value of stirred bulk water (5.5×10−6–6.5×10−6 mol/m2 s MPa). The K⁎HYD is 10 times that of K⁎DW when the hydrogel particles are saturated, indicating a favourable design of the scaffold for methane hydrates formation. The results also demonstrated a higher and more stable water conversion yield (90%) in HYD particles, echoing the improved hydrates formation kinetics and better reversibility. The compromised gas capacity in the mixed system was likely due to the presence of a relatively higher volume of FW, which should be prevented in the future design and development of scaffolding materials for clathrates formation. 2014 Journal Article http://hdl.handle.net/20.500.11937/38895 10.1016/j.ces.2014.01.035 Pergamon restricted
spellingShingle Methane diffusivity
Methane hydrates formation
Kinetics
Porous hydrogel
Reversible methane storage
Shrinking-core model
Shi, B.
Fan, S.
Lou, Xia
Application of the shrinking-core model to the kinetics of repeated formation of methane hydrates in a system of mixed dry-water and porous hydrogel particulates
title Application of the shrinking-core model to the kinetics of repeated formation of methane hydrates in a system of mixed dry-water and porous hydrogel particulates
title_full Application of the shrinking-core model to the kinetics of repeated formation of methane hydrates in a system of mixed dry-water and porous hydrogel particulates
title_fullStr Application of the shrinking-core model to the kinetics of repeated formation of methane hydrates in a system of mixed dry-water and porous hydrogel particulates
title_full_unstemmed Application of the shrinking-core model to the kinetics of repeated formation of methane hydrates in a system of mixed dry-water and porous hydrogel particulates
title_short Application of the shrinking-core model to the kinetics of repeated formation of methane hydrates in a system of mixed dry-water and porous hydrogel particulates
title_sort application of the shrinking-core model to the kinetics of repeated formation of methane hydrates in a system of mixed dry-water and porous hydrogel particulates
topic Methane diffusivity
Methane hydrates formation
Kinetics
Porous hydrogel
Reversible methane storage
Shrinking-core model
url http://hdl.handle.net/20.500.11937/38895