Liquids hydrates

Shell growth on gas (hydrate former) bubble surface Shell growth on gas (hydrate former) bubble surface Shell growth on gas (hydrate former) bubble surface Shell growth on liquid hydrate former droplet surface Shell growth on liquid hydrate former droplet surface Shell growth on liquid hydrate former droplet surface Shell growth on droplet surface of aqueous solution of hydrate former... 

The two calculation methods in Section 4.2 enable prediction of the three-phase (Lw-H-V) gas mixture region extending between the two quadruple points Qi and Q2 in Figure 4.1. Section 4.3 provides a method to use the techniques of Section 4.2 to locate both quadruple points on a pressure-temperature plot. Section 4.3 also discusses equilibrium of three condensed phases [aqueous liquid-hydrate-hydrocarbon liquid (Lw-H-Lhc)] Determination of equilibrium from condensed phases provides an answer to the question, Given a liquid... 

Magnetic resonance imaging (MRI) (Moudrakovski et at., 2004) Liquid, hydrate phase distribution Yes Hydrate conversion from ice particles or water droplets in oil (min) Typically 3000 psi microns Direct visualization of droplet conversion to hydrate crystallites and hydrate shells... 

Rocking hydrate cell, displacement of liquids hydrate decomposed for composition... 

FIGURE 6.19 Raman spectra of carbon dioxide in the liquid, hydrate, and aqueous phase. (Reproduced from Nakano, S., Moritoki, M., Ohgaki, K., J. Chem. Eng. Data, 43, 807 (1998b). With permission from the American Chemical Society.) and hydrogen. (Reproduced from Florusse, L.J., Peters, C.J., Schoonman, J., Hester, K.C., Koh, C.A., Dec, S.F., Marsh, K.N., Sloan, E.D., Science, 306, 469 (2004).)... 

The AA works by emulsifying hydrates in the hydrocarbon liquid. Hydrates are carried as a nonagglomerated slurry, without viscosity increase for up to 50% water cuts. 

All the halides are fairly or even highly soluble in water, as well as other donor solvents such as ethanol, acetone, and THF. The solubility of ZnCl2 in water is extraordinarily great and the highly concentrated solutions correspond to liquid hydrates, i.e., ZnCl2- H20, n = 1-4, with all Cl ions bridging the Zn2+ ions. 

For gases, such as methane, which are supercritical at hydrate forming temperatures, there is one quadruple point, as indicated by point Q1 in Fig. 1. At this point, ice, liquid water, gas and hydrate are in equilibrium. For gases that are subcritical at hydrate forming temperatures, such as ethane, ° there are two quadruple points (Q1 and Q2 in Fig. 2). While Q1 lies at approximately the freezing point of water, Q2 is at approximately the intersection of the hydrate-water-gas three-phase equilibrium curve with the vapor pressure curve. At this latter point, liquid water, gas, hydrate, and liquid hydrate former are all in equilibrium. As seen in Fig. 2, the hydrate... 

Hydration. If the solvent is water, solvation is called hydration. It is an intricate phenomenon, since water is such an intricate, not fully understood liquid. Hydration nearly always involves considerable change in entropy, since anything altering the fluctuating network of hydrogen bonds alters entropy. Four kinds of solute molecules or groups may be conveniently distinguished ... 

Figure 3. Comparison of the dimensions of the guest molecules with the free diameter of the available voids in gas and liquid hydrates (from ref. 3).

Liquid hydrate clathrates are formed in conditions similar to those for gas hydrates. The corresponding physicochemical data are given in Table 1. Liquid... 

Table 1. Physicochemical Data on Liquid Hydrates (From Ref. 1)...

Steric criteria are also valuable to explain the formation of liquid hydrate clathrates (Fig. 3, 16.2.2.1). They appear for molecules having dimensions between the free diameters of the largest voids of types I and II structures, d, 2 and dn,2- The situation is the same for double liquid hydrates, but here a type I structure is theoretically possible in some cases, e.g., CHjBr, COS and CH3I. For molecules with dimensions >690 pm, no hydrates are formed. This selectivity in encaging certain molecules but not others has been used for fractionation of natural gas by clathration and for desalination of sea water "... 

Because of the relatively strong host-guest interactions, these pseudo-clathrates are more stable than gas and liquid hydrates and exhibit higher melting points. 

As in gas and liquid hydrates, the formation of Si and Ge clathrates is mostly governed by steric criteria ". Assuming for the alkali-metal atoms a radius close to the covalent radii , the analytical and crystallographic data listed in Table 1 can be explained by means of a diagram such as Fig. 1. 

Figure 3.10 Schematic representation of ocean storage options. In dissolution type ocean storage, the carbon dioxide rapidly dissolves in the ocean water, whereas in lake type ocean storage, the carbon dioxide is initially a liquid on the sea floor, soon crystallizing as a hydrate. Given sufficient time, all forms of carbon dioxide - gas, liquid, hydrate - will dissolve in the water.

Henry s law This states that the solubility of a gas is proportional to the pressure of the gas above the liquid , hydration of ions The attachment of water molecules to a central ion. 

Thermal fixation techniques are preferred in the study of microstructured liquids, hydrated biological specimens, fluid-filled porous media, etc. Because thermal fixation is used for such diverse applications, there are a wide variety of fixation techniques and associated equipment that impart microscopic stability to the specimen. 

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