The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Ryo Ohmura - One of the best experts on this subject based on the ideXlab platform.
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phase equilibrium for structure ii clathrate hydrates formed with fluoromethane propan 2 ol 2 methyl 2 Propanol or 2 propanone
The Journal of Chemical Thermodynamics, 2012Co-Authors: Masatoshi Imai, Shinnosuke Nitta, Satoshi Takeya, Ryo OhmuraAbstract:Abstract This paper presents phase-equilibrium pressure–temperature data for the clathrate hydrates formed in the three component systems each consisting of a hydrate-forming gas, a water-soluble freezing-point depression material, and water. These systems are {fluoromethane (CH 3 F) + propan-2-ol + water}, (fluoromethane + 2-methyl-2-Propanol + water), and (fluoromethane + 2-propanone + water). The mole ratio of water and the water-soluble material (papan-2-ol, 2-methyl-2-Propanol, or 2-propanone) was 17:1. The temperature range over which the phase-equilibrium measurements were performed extended to 267.6 K on the lower side and 295.8 K on the higher side. The phase-equilibrium pressures in these three systems were found to be lower than that in the binary (fluoromethane + water) system at a given system temperature. The crystallographic structure of the hydrates formed in the systems with 2-methyl-2-Propanol and 2-propanone was determined to be structure II based on the powder X-ray diffraction measurements.
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hydrogen bonding alcohol water interactions in binary ethanol 1 Propanol and 2 Propanol methane structure ii clathrate hydrates
Journal of Chemical Physics, 2010Co-Authors: Saman Alavi, Ryo Ohmura, Satoshi Takeya, John A RipmeesterAbstract:The small alcohols ethanol, 1-Propanol, and 2-Propanol are miscible in water, form strong hydrogen bonds with water molecules, and are usually known as inhibitors for clathrate hydrate formation. However, in the presence of methane or other help gases, clathrate hydrates of these substances have been synthesized. In this work, molecular dynamics simulations are used to characterize guest-host hydrogen bonding, microscopic structures, and guest dynamics of binary structure II clathrate hydrates of methane (small cages) with ethanol, 1-Propanol, and 2-Propanol in the temperature range of 100–250 K to gain insight into the stability of these materials. We observe that these alcohols form structures with dynamic long-lived (∼10 ps) guest-host hydrogen bonds in the hydrate phases while maintaining the general cage structure of the sII clathrate hydrate form. The hydroxyl groups of ethanol, 1-Propanol, and 2-Propanol act as both proton acceptors and proton donors and there is a considerable probability of simul...
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hydrogen bonding alcohol water interactions in binary ethanol 1 Propanol and 2 Propanol methane structure ii clathrate hydrates
Journal of Chemical Physics, 2010Co-Authors: Saman Alavi, Ryo Ohmura, Satoshi Takeya, Tom K Woo, John A RipmeesterAbstract:The small alcohols ethanol, 1-Propanol, and 2-Propanol are miscible in water, form strong hydrogen bonds with water molecules, and are usually known as inhibitors for clathrate hydrate formation. However, in the presence of methane or other help gases, clathrate hydrates of these substances have been synthesized. In this work, molecular dynamics simulations are used to characterize guest-host hydrogen bonding, microscopic structures, and guest dynamics of binary structure II clathrate hydrates of methane (small cages) with ethanol, 1-Propanol, and 2-Propanol in the temperature range of 100-250 K to gain insight into the stability of these materials. We observe that these alcohols form structures with dynamic long-lived ( approximately 10 ps) guest-host hydrogen bonds in the hydrate phases while maintaining the general cage structure of the sII clathrate hydrate form. The hydroxyl groups of ethanol, 1-Propanol, and 2-Propanol act as both proton acceptors and proton donors and there is a considerable probability of simultaneous hydrogen bonding between O and H hydroxyl atoms with different cage water molecules. The presence of the nonpolar methane molecule and the hydrophobic moieties of the alcohols stabilize the hydrate phase, despite the strong and prevalent alcohol-water hydrogen bonding. The effect of the alcohol molecules on the structural properties of the hydrate and the effect of guest-host hydrogen bonding on the guest dynamics are studied.
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clathrate hydrate formed with methane and 2 Propanol confirmation of structure ii hydrate formation
Industrial & Engineering Chemistry Research, 2004Co-Authors: Ryo Ohmura, Satoshi Takeya, And Tsutomu Uchida, Takao EbinumaAbstract:This paper reports confirmation of structure II hydrate formation in a methane−2-Propanol−water system, which was previously suggested by Ostergaard et al. (Ind. Eng. Chem. Res. 2002, 41, 2064−2068) based on a comparison of the phase-equilibrium data with corresponding statistical-thermodynamics predictions. A hydrate crystal sample was prepared with a 16.4 mass % aqueous solution of 2-Propanol pressurized with methane and then subjected to a powder X-ray diffraction analysis. The X-ray diffraction pattern thus obtained from the sample indicated that the crystallographic structure of the hydrate was structure II. The pressure−temperature data for aqueous liquid−hydrate−methane-rich vapor three-phase equilibrium in a temperature range from T = 273 to 283 K are also reported.
Satoshi Takeya - One of the best experts on this subject based on the ideXlab platform.
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phase equilibrium for structure ii clathrate hydrates formed with fluoromethane propan 2 ol 2 methyl 2 Propanol or 2 propanone
The Journal of Chemical Thermodynamics, 2012Co-Authors: Masatoshi Imai, Shinnosuke Nitta, Satoshi Takeya, Ryo OhmuraAbstract:Abstract This paper presents phase-equilibrium pressure–temperature data for the clathrate hydrates formed in the three component systems each consisting of a hydrate-forming gas, a water-soluble freezing-point depression material, and water. These systems are {fluoromethane (CH 3 F) + propan-2-ol + water}, (fluoromethane + 2-methyl-2-Propanol + water), and (fluoromethane + 2-propanone + water). The mole ratio of water and the water-soluble material (papan-2-ol, 2-methyl-2-Propanol, or 2-propanone) was 17:1. The temperature range over which the phase-equilibrium measurements were performed extended to 267.6 K on the lower side and 295.8 K on the higher side. The phase-equilibrium pressures in these three systems were found to be lower than that in the binary (fluoromethane + water) system at a given system temperature. The crystallographic structure of the hydrates formed in the systems with 2-methyl-2-Propanol and 2-propanone was determined to be structure II based on the powder X-ray diffraction measurements.
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hydrogen bonding alcohol water interactions in binary ethanol 1 Propanol and 2 Propanol methane structure ii clathrate hydrates
Journal of Chemical Physics, 2010Co-Authors: Saman Alavi, Ryo Ohmura, Satoshi Takeya, John A RipmeesterAbstract:The small alcohols ethanol, 1-Propanol, and 2-Propanol are miscible in water, form strong hydrogen bonds with water molecules, and are usually known as inhibitors for clathrate hydrate formation. However, in the presence of methane or other help gases, clathrate hydrates of these substances have been synthesized. In this work, molecular dynamics simulations are used to characterize guest-host hydrogen bonding, microscopic structures, and guest dynamics of binary structure II clathrate hydrates of methane (small cages) with ethanol, 1-Propanol, and 2-Propanol in the temperature range of 100–250 K to gain insight into the stability of these materials. We observe that these alcohols form structures with dynamic long-lived (∼10 ps) guest-host hydrogen bonds in the hydrate phases while maintaining the general cage structure of the sII clathrate hydrate form. The hydroxyl groups of ethanol, 1-Propanol, and 2-Propanol act as both proton acceptors and proton donors and there is a considerable probability of simul...
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hydrogen bonding alcohol water interactions in binary ethanol 1 Propanol and 2 Propanol methane structure ii clathrate hydrates
Journal of Chemical Physics, 2010Co-Authors: Saman Alavi, Ryo Ohmura, Satoshi Takeya, Tom K Woo, John A RipmeesterAbstract:The small alcohols ethanol, 1-Propanol, and 2-Propanol are miscible in water, form strong hydrogen bonds with water molecules, and are usually known as inhibitors for clathrate hydrate formation. However, in the presence of methane or other help gases, clathrate hydrates of these substances have been synthesized. In this work, molecular dynamics simulations are used to characterize guest-host hydrogen bonding, microscopic structures, and guest dynamics of binary structure II clathrate hydrates of methane (small cages) with ethanol, 1-Propanol, and 2-Propanol in the temperature range of 100-250 K to gain insight into the stability of these materials. We observe that these alcohols form structures with dynamic long-lived ( approximately 10 ps) guest-host hydrogen bonds in the hydrate phases while maintaining the general cage structure of the sII clathrate hydrate form. The hydroxyl groups of ethanol, 1-Propanol, and 2-Propanol act as both proton acceptors and proton donors and there is a considerable probability of simultaneous hydrogen bonding between O and H hydroxyl atoms with different cage water molecules. The presence of the nonpolar methane molecule and the hydrophobic moieties of the alcohols stabilize the hydrate phase, despite the strong and prevalent alcohol-water hydrogen bonding. The effect of the alcohol molecules on the structural properties of the hydrate and the effect of guest-host hydrogen bonding on the guest dynamics are studied.
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clathrate hydrate formed with methane and 2 Propanol confirmation of structure ii hydrate formation
Industrial & Engineering Chemistry Research, 2004Co-Authors: Ryo Ohmura, Satoshi Takeya, And Tsutomu Uchida, Takao EbinumaAbstract:This paper reports confirmation of structure II hydrate formation in a methane−2-Propanol−water system, which was previously suggested by Ostergaard et al. (Ind. Eng. Chem. Res. 2002, 41, 2064−2068) based on a comparison of the phase-equilibrium data with corresponding statistical-thermodynamics predictions. A hydrate crystal sample was prepared with a 16.4 mass % aqueous solution of 2-Propanol pressurized with methane and then subjected to a powder X-ray diffraction analysis. The X-ray diffraction pattern thus obtained from the sample indicated that the crystallographic structure of the hydrate was structure II. The pressure−temperature data for aqueous liquid−hydrate−methane-rich vapor three-phase equilibrium in a temperature range from T = 273 to 283 K are also reported.
John A Ripmeester - One of the best experts on this subject based on the ideXlab platform.
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hydrogen bonding alcohol water interactions in binary ethanol 1 Propanol and 2 Propanol methane structure ii clathrate hydrates
Journal of Chemical Physics, 2010Co-Authors: Saman Alavi, Ryo Ohmura, Satoshi Takeya, John A RipmeesterAbstract:The small alcohols ethanol, 1-Propanol, and 2-Propanol are miscible in water, form strong hydrogen bonds with water molecules, and are usually known as inhibitors for clathrate hydrate formation. However, in the presence of methane or other help gases, clathrate hydrates of these substances have been synthesized. In this work, molecular dynamics simulations are used to characterize guest-host hydrogen bonding, microscopic structures, and guest dynamics of binary structure II clathrate hydrates of methane (small cages) with ethanol, 1-Propanol, and 2-Propanol in the temperature range of 100–250 K to gain insight into the stability of these materials. We observe that these alcohols form structures with dynamic long-lived (∼10 ps) guest-host hydrogen bonds in the hydrate phases while maintaining the general cage structure of the sII clathrate hydrate form. The hydroxyl groups of ethanol, 1-Propanol, and 2-Propanol act as both proton acceptors and proton donors and there is a considerable probability of simul...
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hydrogen bonding alcohol water interactions in binary ethanol 1 Propanol and 2 Propanol methane structure ii clathrate hydrates
Journal of Chemical Physics, 2010Co-Authors: Saman Alavi, Ryo Ohmura, Satoshi Takeya, Tom K Woo, John A RipmeesterAbstract:The small alcohols ethanol, 1-Propanol, and 2-Propanol are miscible in water, form strong hydrogen bonds with water molecules, and are usually known as inhibitors for clathrate hydrate formation. However, in the presence of methane or other help gases, clathrate hydrates of these substances have been synthesized. In this work, molecular dynamics simulations are used to characterize guest-host hydrogen bonding, microscopic structures, and guest dynamics of binary structure II clathrate hydrates of methane (small cages) with ethanol, 1-Propanol, and 2-Propanol in the temperature range of 100-250 K to gain insight into the stability of these materials. We observe that these alcohols form structures with dynamic long-lived ( approximately 10 ps) guest-host hydrogen bonds in the hydrate phases while maintaining the general cage structure of the sII clathrate hydrate form. The hydroxyl groups of ethanol, 1-Propanol, and 2-Propanol act as both proton acceptors and proton donors and there is a considerable probability of simultaneous hydrogen bonding between O and H hydroxyl atoms with different cage water molecules. The presence of the nonpolar methane molecule and the hydrophobic moieties of the alcohols stabilize the hydrate phase, despite the strong and prevalent alcohol-water hydrogen bonding. The effect of the alcohol molecules on the structural properties of the hydrate and the effect of guest-host hydrogen bonding on the guest dynamics are studied.
Lianzhong Zhang - One of the best experts on this subject based on the ideXlab platform.
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vapor liquid equilibria for 2 Propanol dehydration through extractive distillation using mixed solvent of ethylene glycol and choline chloride
Journal of Chemical & Engineering Data, 2018Co-Authors: Lianzhong Zhang, Xuejiao Wu, Yichi ZhangAbstract:The mixed solvent of ethylene glycol (EG) and choline chloride (ChCl) was tested as an entrainer for 2-Propanol dehydration by extractive distillation. Isobaric vapor–liquid equilibrium (VLE) data were measured at 101.3 kPa for the quaternary system water + 2-Propanol + EG + ChCl. The NRTL equation was used for the modeling of the quaternary VLE. Mean absolute deviations were 0.26 K and 0.0036 for equilibrium temperature and vapor mole fraction of 2-Propanol, respectively. As compared with EG alone, the existence of ChCl in the solvent significantly decreases the activity coefficient of water and increases the activity coefficient of 2-Propanol, both enhancing the relative volatility of 2-Propanol to water. The azeotrope of water +2-Propanol can be removed with the addition of the deep eutectic mixture EG + ChCl 2:1 at a solvent mass fraction of 0.157. The mixed solvent may be readily applied in extractive distillation of 2-Propanol and water, replacing the frequently used mixed solvent of ethylene glycol...
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selection of ionic liquids as entrainers for separation of water and 2 Propanol
Fluid Phase Equilibria, 2007Co-Authors: Lianzhong Zhang, Jianzhi Han, Dongshun DengAbstract:Abstract A procedure for experimental evaluation of ionic liquids (ILs) as entrainers was proposed. For selection of ILs which can be potentially used for the separation of the azeotropic mixture of water and 2-Propanol by extractive distillation, vapor–liquid equilibria were measured for ternary systems of water + 2-Propanol + IL at 100 kPa. A previously presented ebulliometer was modified to improve the reliability of measurement of equilibrium temperature and vapor phase composition. A packed column was adopted in the place of the Cottrell pump tube to enhance the equilibration of temperature and compositions of the arising mixture of vapor and liquid. By use of the modified ebulliometer, the experimental measurement was performed in a way of continuous synthesis, in which analysis of liquid phase composition was avoided. While the mole fraction of 2-Propanol calculated on IL-free basis, x ′ 2 , was kept almost unchanged at 0.95, isobaric T, x, y data were measured at different IL mass fractions. Activity coefficients of the volatile components as well as their relative volatility were obtained from the experimental data without the need of a thermodynamic model of the liquid phase. There were seven ILs in our investigation: 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]), 1-butyl-3-methylimidazolium dicyanamide ([bmim][N(CN)2]), 1-ethyl-3-methylimidazolium dicyanamide ([emim][N(CN)2]), 1-butyl-3-methylimidazolium acetate ([bmim][OAc]), 1-ethyl-3-methylimidazolium acetate ([emim][OAc]), and 1-butyl-3-methylimidazolium chloride ([bmim][Cl]). Results showed that the activity coefficients are mainly decided by the anions and the interactions of the anions with water and 2-Propanol are in the same order, namely [Cl]− ≈ [OAc]− > [N(CN)2]− > [BF4]−. The similarity in the interactions cancels in some extent the effect of the ILs. While the cation has relatively small effect on the activity coefficients, their interactions with water and 2-Propanol show reversed orders, namely [emim]+ > [bmim]+ for interactions with water and [emim]+
Saman Alavi - One of the best experts on this subject based on the ideXlab platform.
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hydrogen bonding alcohol water interactions in binary ethanol 1 Propanol and 2 Propanol methane structure ii clathrate hydrates
Journal of Chemical Physics, 2010Co-Authors: Saman Alavi, Ryo Ohmura, Satoshi Takeya, John A RipmeesterAbstract:The small alcohols ethanol, 1-Propanol, and 2-Propanol are miscible in water, form strong hydrogen bonds with water molecules, and are usually known as inhibitors for clathrate hydrate formation. However, in the presence of methane or other help gases, clathrate hydrates of these substances have been synthesized. In this work, molecular dynamics simulations are used to characterize guest-host hydrogen bonding, microscopic structures, and guest dynamics of binary structure II clathrate hydrates of methane (small cages) with ethanol, 1-Propanol, and 2-Propanol in the temperature range of 100–250 K to gain insight into the stability of these materials. We observe that these alcohols form structures with dynamic long-lived (∼10 ps) guest-host hydrogen bonds in the hydrate phases while maintaining the general cage structure of the sII clathrate hydrate form. The hydroxyl groups of ethanol, 1-Propanol, and 2-Propanol act as both proton acceptors and proton donors and there is a considerable probability of simul...
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hydrogen bonding alcohol water interactions in binary ethanol 1 Propanol and 2 Propanol methane structure ii clathrate hydrates
Journal of Chemical Physics, 2010Co-Authors: Saman Alavi, Ryo Ohmura, Satoshi Takeya, Tom K Woo, John A RipmeesterAbstract:The small alcohols ethanol, 1-Propanol, and 2-Propanol are miscible in water, form strong hydrogen bonds with water molecules, and are usually known as inhibitors for clathrate hydrate formation. However, in the presence of methane or other help gases, clathrate hydrates of these substances have been synthesized. In this work, molecular dynamics simulations are used to characterize guest-host hydrogen bonding, microscopic structures, and guest dynamics of binary structure II clathrate hydrates of methane (small cages) with ethanol, 1-Propanol, and 2-Propanol in the temperature range of 100-250 K to gain insight into the stability of these materials. We observe that these alcohols form structures with dynamic long-lived ( approximately 10 ps) guest-host hydrogen bonds in the hydrate phases while maintaining the general cage structure of the sII clathrate hydrate form. The hydroxyl groups of ethanol, 1-Propanol, and 2-Propanol act as both proton acceptors and proton donors and there is a considerable probability of simultaneous hydrogen bonding between O and H hydroxyl atoms with different cage water molecules. The presence of the nonpolar methane molecule and the hydrophobic moieties of the alcohols stabilize the hydrate phase, despite the strong and prevalent alcohol-water hydrogen bonding. The effect of the alcohol molecules on the structural properties of the hydrate and the effect of guest-host hydrogen bonding on the guest dynamics are studied.