Phase Equilibrium Conditions for Krypton Clathrate Hydrate below the Freezing Point of Water

One of the promising applications of clathrate/gas hydrates is the transport and storage of natural gas. Semi-clathrate hydrates have received more attention due to milder pressure/temperature stability conditions compared to ordinary clathrate hydrates. The most commonly reported semi-clathrate hydrates are formed from a combination of gas + water + quaternary ammonium salts. In this work, a total of 53 equilibrium data for semi-clathrate hydrates of methane + TetraButylAmmonium Bromide (TBAB)/TetraButylAmmonium Acetate (TBAA) aqueous solutions were experimentally measured. For TBAB, three concentrations including 0.0350, 0.0490, and 0.1500 mass fractions were used. For TBAA, a solution with a 0.0990 mass fraction was used. Additionally, the modified Chen–Guo model was applied to calculate the hydrate phase equilibrium conditions of methane + TBAB/TBAA aqueous solutions. The model can accurately calculate the aforementioned semi-clathrate hydrate phase equilibrium conditions with the Average Absolute Deviations ((AAD)T and (AAD)P) of 0.1 K and 0.08 MPa, respectively. The temperature increments for 0.0350, 0.0490, and 0.1500 mass fractions of TBAB are 7.7, 9.4, and 13.5 K, respectively. This value for 0.0990 mass fraction of TBAA is 6.2 K. Therefore, it is concluded that TBAB is a stronger hydrate promoter compared to TBAA.

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Phase Equilibrium for Clathrate Hydrates Formed with Methane + Ethane + Propane Mixtures at Temperatures below the Freezing Point of Water

Journal of Chemical & Engineering Data ◽

10.1021/je900363n ◽

2010 ◽

Vol 55 (1) ◽

pp. 358-361 ◽

Cited By ~ 7

Author(s):

Keita Yasuda ◽

Hiroyuki Ogawa ◽

Ryo Ohmura

Keyword(s):

Phase Equilibrium ◽

Freezing Point ◽

Clathrate Hydrates

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HYDROGEN PEROXIDE AND ITS ANALOGUES: II. PHASE EQUILIBRIUM IN THE SYSTEM HYDROGEN PEROXIDE – WATER

Canadian Journal of Chemistry ◽

10.1139/v51-016 ◽

1951 ◽

Vol 29 (2) ◽

pp. 123-132 ◽

Cited By ~ 30

Author(s):

William T. Foley ◽

Paul A. Giguère

Keyword(s):

Hydrogen Peroxide ◽

Phase Equilibrium ◽

Solid Solutions ◽

Freezing Point ◽

Platinum Resistance Thermometer ◽

Platinum Resistance ◽

Radioactive Tracers ◽

Resistance Thermometer ◽

Pure Solution

A precision freezing point apparatus with platinum resistance thermometer was used to investigate the system hydrogen peroxide – water over the whole concentration range. The freezing point of the purest sample of hydrogen peroxide obtained by repeated fractional crystallizations of a large quantity of 99.6% pure solution was found to be −0.461°C; that of the dihydrate was −52.10°C. The two eutectics occur at concentrations of 45.2% and 61.2% H2O2 and at temperatures of −52.4° and −56.5°C. respectively. Contrary to what has been reported previously, water and hydrogen peroxide do not form solid solutions together. This was proved conclusively by applying the technique of radioactive tracers to the 'wet residue' method of Schreinemakers.

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