TY - JOUR
T1 - Crystal growth of clathrate hydrate at the interface between hydrocarbon gas mixture and liquid water
AU - Saito, Kota
AU - Kishimoto, Masatoshi
AU - Tanaka, Ryo
AU - Ohmura, Ryo
PY - 2011/1/5
Y1 - 2011/1/5
N2 - This paper reports the visual observations of the formation and growth of clathrate hydrate crystals on the surface of a water droplet exposed to a methane + ethane + propane gas mixture. The compositions of the methane + ethane + propane gas mixtures are (i) 99.47:0.51:0.02, (ii) 94.1:5.8:0.1, and (iii) 90:7:3 molar ratio. The nucleation of the hydrate first occurred at a random point on the water droplet and then the hydrate grew to form a polycrystalline layer covering the droplet. We visually observed the individual crystals that constitute the polycrystalline hydrate layer and classified the morphology of the hydrate crystals depending on the system subcooling δTsub and system pressure. It was found that the size of the individual mixed-gas hydrate crystals decreased with the increasing δTsub as observed for the simple hydrates each formed with methane, ethane, or propane. The size of the individual crystals decreased with the increasing molar ratio of methane in the gas mixtures. The mixed-gas hydrate crystals exhibited a morphology different from that of the simple methane hydrate. We also measured the lateral growth rates of the hydrate-film propagation. In any of the systems, the rates increased with increasing δTsub as observed in other hydrate-forming systems.
AB - This paper reports the visual observations of the formation and growth of clathrate hydrate crystals on the surface of a water droplet exposed to a methane + ethane + propane gas mixture. The compositions of the methane + ethane + propane gas mixtures are (i) 99.47:0.51:0.02, (ii) 94.1:5.8:0.1, and (iii) 90:7:3 molar ratio. The nucleation of the hydrate first occurred at a random point on the water droplet and then the hydrate grew to form a polycrystalline layer covering the droplet. We visually observed the individual crystals that constitute the polycrystalline hydrate layer and classified the morphology of the hydrate crystals depending on the system subcooling δTsub and system pressure. It was found that the size of the individual mixed-gas hydrate crystals decreased with the increasing δTsub as observed for the simple hydrates each formed with methane, ethane, or propane. The size of the individual crystals decreased with the increasing molar ratio of methane in the gas mixtures. The mixed-gas hydrate crystals exhibited a morphology different from that of the simple methane hydrate. We also measured the lateral growth rates of the hydrate-film propagation. In any of the systems, the rates increased with increasing δTsub as observed in other hydrate-forming systems.
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U2 - 10.1021/cg101310z
DO - 10.1021/cg101310z
M3 - Article
AN - SCOPUS:78651106821
VL - 11
SP - 295
EP - 301
JO - Crystal Growth and Design
JF - Crystal Growth and Design
SN - 1528-7483
IS - 1
ER -