学術雑誌論文

学術雑誌論文

text

Fluid Phase Equilibria. 2019, 488, p. 48-53

Phase equilibrium relations for tetra-n-butylphosphonium acetate semiclathrate hydrate systems in the presence of methane, carbon dioxide, nitrogen, or ethane

Elsevier B.V.

英語

text

2019-06-01

https://doi.org/10.1016/j.fluid.2019.01.027

Thermodynamic stabilities of tetra-n-butylphosphonium acetate (TBP-Ace) semiclathrate hydrates in the presence of methane (CH 4 ), carbon dioxide (CO 2 ), nitrogen (N 2 ), or ethane (C 2 H 6 ) were measured in a pressure range up to approximately 5 MPa. The dissociation temperature of TBP-Ace + CH 4 , TBP-Ace + CO 2 , and TBP-Ace + N 2 semiclathrate hydrates increased drastically with an increase in pressure, which means that CH 4 , CO 2 , and N 2 molecules occupy the vacant cages of the TBP-Ace semiclathrate hydrate. On the other hand, the C 2 H 6 molecules hardly occupied the cages, resulting in small pressure dependence of the dissociation temperature. Raman spectra and powder X-ray diffraction patterns of TBP-Ace + CO 2 semiclathrate hydrate reveal that the phase transition occurs at 1.04 ± 0.04 MPa and 285.88 ± 0.05 K. One of the possible reasons why the phase transition occurs is that the carbonate and/or hydrogen carbonate anions derived from the CO 2 molecules are replaced with some of acetate anions in the TBP-Ace + CO 2 semiclathrate hydrate.

©2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license

91303

Phase equilibrium relations for tetra-n-butylphosphonium acetate semiclathrate hydrate systems in the presence of methane, carbon dioxide, nitrogen, or ethane

Elsevier B.V.

英語

2019-06-01

Fluid Phase Equilibria

488

48

53

https://doi.org/10.1016/j.fluid.2019.01.027

https://hdl.handle.net/11094/91303