TY - JOUR
T1 - Phase equilibrium for ozone-containing hydrates formed from an (ozone + oxygen) gas mixture coexisting with gaseous carbon dioxide and liquid water
AU - Muromachi, Sanehiro
AU - Ohmura, Ryo
AU - Mori, Yasuhiko H.
N1 - Funding Information:
This study was subsidized in part by the Keio University Global Centre of Excellence Program “Centre for Education and Research of Symbiotic, Safe and Secure System Design”. S.M. thanks for the support provided by the Japan Society for the Promotion of Science (JSPS) through the program “Grant-in-Aid for JSPS Fellows of the Ministry of Education, Culture, Sports, Science, and Technology (MEXT)” (Grant No. 23-56572).
PY - 2012/6
Y1 - 2012/6
N2 - The paper reports the three-phase (gas + aqueous liquid + hydrate) equilibrium pressure (p) versus temperature (T) data for a (O 3 + O 2 + CO 2 + H 2O) system and, for comparison, corresponding data for a (O 2 + CO 2 + H 2O) system for the first time. These data cover the temperature range from (272 to 279) K, corresponding to pressures up to 4 MPa, for each of the three different (O 3 + O 2)-to-CO 2 or O 2-to-CO 2 mole ratios in the gas phase, which are approximately 1:9, 2:8, and 3:7, respectively. The mole fraction of ozone in the gas phase of the (O 3 + O 2 + CO 2 + H 2O) system was from ∼0.004 to ∼0.02. The modified pressure-search method, developed in our previous study [S. Muromachi, T. Nakajima, R. Ohmura, Y.H. Mori, Fluid Phase Equilib. 305 (2011) 145-151] for p-T measurements in the presence of chemically unstable ozone, was applied, having been further modified for dealing with highly water-soluble CO 2, for the (O 3 + O 2 + CO 2 + H 2O) system, while the conventional temperature-search method was used for the (O 2 + CO 2 + H 2O) system. The measurement uncertainties (with 95% coverage) were ±0.11 K for T, ±6.0 kPa for p, and ±0.0015 for the mole fraction of each species in the gas phase. It was confirmed that, at a given CO 2 fraction in the gas phase, p for the (O 3 + O 2 + CO 2 + H 2O) system was consistently lower than that for the (O 2 + CO 2 + H 2O) system over the entire T range of the present measurements, indicating a preference of O 3 to O 2 in the uptake of guest-gas molecules into the cages of a structure I hydrate.
AB - The paper reports the three-phase (gas + aqueous liquid + hydrate) equilibrium pressure (p) versus temperature (T) data for a (O 3 + O 2 + CO 2 + H 2O) system and, for comparison, corresponding data for a (O 2 + CO 2 + H 2O) system for the first time. These data cover the temperature range from (272 to 279) K, corresponding to pressures up to 4 MPa, for each of the three different (O 3 + O 2)-to-CO 2 or O 2-to-CO 2 mole ratios in the gas phase, which are approximately 1:9, 2:8, and 3:7, respectively. The mole fraction of ozone in the gas phase of the (O 3 + O 2 + CO 2 + H 2O) system was from ∼0.004 to ∼0.02. The modified pressure-search method, developed in our previous study [S. Muromachi, T. Nakajima, R. Ohmura, Y.H. Mori, Fluid Phase Equilib. 305 (2011) 145-151] for p-T measurements in the presence of chemically unstable ozone, was applied, having been further modified for dealing with highly water-soluble CO 2, for the (O 3 + O 2 + CO 2 + H 2O) system, while the conventional temperature-search method was used for the (O 2 + CO 2 + H 2O) system. The measurement uncertainties (with 95% coverage) were ±0.11 K for T, ±6.0 kPa for p, and ±0.0015 for the mole fraction of each species in the gas phase. It was confirmed that, at a given CO 2 fraction in the gas phase, p for the (O 3 + O 2 + CO 2 + H 2O) system was consistently lower than that for the (O 2 + CO 2 + H 2O) system over the entire T range of the present measurements, indicating a preference of O 3 to O 2 in the uptake of guest-gas molecules into the cages of a structure I hydrate.
KW - Carbon dioxide
KW - Clathrate hydrate
KW - Ozone
KW - Phase equilibrium
UR - http://www.scopus.com/inward/record.url?scp=84857998237&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84857998237&partnerID=8YFLogxK
U2 - 10.1016/j.jct.2012.01.009
DO - 10.1016/j.jct.2012.01.009
M3 - Article
AN - SCOPUS:84857998237
SN - 0021-9614
VL - 49
SP - 1
EP - 6
JO - Journal of Chemical Thermodynamics
JF - Journal of Chemical Thermodynamics
ER -