Water hydrate-like phase

Since mixtures of methane, ethane, and propane make up nearly 97 mol% of a typical natural gas mixture, the hydrate phase behavior of a natural gas mixture in contact with water will likely be approximated by that of a simple mixture of these three components in contact with water. 

The rapid equilibration of soil 3 is consistent with sorption on a hydrated metal oxide surface while the slow equilibration in the case of the organic soil suggests initial surface sorption followed by slow diffusion of the unionized acid molecules into the interior of a lipid-like phase. Aqueous sodium hydroxide is more efficient than water in eluting the sorbed 4-amino-3,5,6-trichloropicolinic acid, which may be caused partly by its ability to break up and emulsify lipid systems. 

Spontaneous conversion of y-alumina into bayerite in contact with solution is reported in [110], A diffuse reflectance Fourier transform infrared (DR-FTIR) study demonstrated transformation of y-alumina into bayerite-like phase on the surface [150], Surface regions in a- and y-alumina convert to hydrated alumina similar to gibbsite or bayerite after exposure to water, according to [136], Incorvati [151] observed transformation of a-alumina into bayerite or gibbsite at room temperature within 1 day. 

Water dynamics in clays has been studied for Na and Li montmoril-lonites, vermiculites and hectorites . Quasi-elastic neutron scattering and nuclear magnetic resonance indicate the existence of slow and fast motions of water molecules. The fastest motion (tr 10 s) has the same value as in normal water and is almost temperature independent. The slow motion is anisotropic and associated with the hydrated cation shell. In materials with high water content (interparticular liquid-like phase) the distinction between rotational and translational motions appears possible . 

To prepare gas for evacuation it is necessary to separate the gas and liquid phases and extract or inhibit any components in the gas which are likely to cause pipeline corrosion or blockage. Components which can cause difficulties are water vapour (corrosion, hydrates), heavy hydrocarbons (2-phase flow or wax deposition in pipelines), and contaminants such as carbon dioxide (corrosion) and hydrogen sulphide (corrosion, toxicity). In the case of associated gas, if there is no gas market, gas may have to be flared or re-injected. If significant volumes of associated gas are available it may be worthwhile to extract natural gas liquids (NGLs) before flaring or reinjection. Gas may also have to be treated for gas lifting or for use as a fuel. 

Cationic quaternary ammonium compounds such as distearyldimethylammonium-chloride (DSDMAC) used as a softener and as an antistatic, form hydrated particles in a dispersed phase having a similar structure to that of the multilayered liposomes or vesicles of phospholipids 77,79). This liposome-like structure could be made visible by electron microscopy using the freeze-fracture replica technique as shown by Okumura et al. 79). The concentric circles observed should be bimolecular lamellar layers with the sandwiched parts being the entrapped water. In addition, the longest spacings of the small angle X-ray diffraction pattern can be attributed to the inter-lamellar distances. These liposome structures are formed by the hydrated detergent not only in the gel state but also at relatively low concentrations. 

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