Methane solubility in water

Calculations of Methane Solubility in Water and Seawater, at Conditions Above and Below the Hydrate Point... 

Fig. 6. Predictions of methane solubility in water. Shown is the bubble point pressure as a function of mixture composition (in mole fraction methane) at three different temperatures for two equations of state compared with experimental data.

Docusate Calcium. Dioctyl calcium sulfosuccinate [128-49-4] (calcium salt of l,4-bis(2-ethylhexyl)ester butanedioic acid) (11) is a white amorphous soHd having the characteristic odor of octyl alcohol. It is very slightly soluble in water, and very soluble in alcohol, polyethylene glycol 400, and com oil. It may be prepared directly from dioctyl sodium sulfo succinate dissolved in 2-propanol, by reaction with a methan olic solution of calcium chloride. 

Because carbon dioxide is about 1.5 times as dense as air and 2.8 times as dense as methane, it tends to move toward the bottom of the landfill. As a result, the concentration of carbon dioxide in the lower portions of landfill may be high for years. Ultimately, because of its density, carbon dioxide will also move downward through the underlying formation until it reaches the groundwater. Because carbon dioxide is readily soluble in water, it usually lowers the pH, which in turn can increase the hardness and mineral content of the groundwater through the solubilization of calcium and magnesium carbonates. 

Formaldehyde is highly toxic and reactive and not suitable as a growth substrate. Methanol is more soluble in water than methane and would seem a suitable substrate. 

Figure 3.27 Methane hydrate film development at the water-methane interface from dissolved methane in the aqueous phase, as indicated from Raman spectroscopy (a) and methane solubility predictions (b). (a) A series of Raman spectra of dissolved methane collected at different temperatures during the continuous cooling process. Spectra marked A through E correspond to temperatures of 24°C, 20°C, 15.6°C, 10.2°C, and 2.8°C, respectively. (b) A schematic illustration of temperature dependencies of the equilibrium methane concentration in liquid water (C = without hydrate, Qjh = with hydrate). The scale of the vertical axis is arbitrary, but the Raman peak area is proportional to methane dissolved in water. Points A through F correspond to different temperatures during the continuous cooling process. (From Subramanian, S., Measurements ofClathrate Hydrates Containing Methane and Ethane Using Raman Spectroscopy, Ph.D. Thesis, Colorado School of Mines, Golden, CO (2000). With permission.)...

Rehder et al. (2004) measured the dissociation rates of methane and carbon dioxide hydrates in seawater during a seafloor experiment. The seafloor conditions provided constant temperature and pressure conditions, and enabled heat transfer limitations to be largely eliminated. Hydrate dissociation was caused by differences in concentration of the guest molecule in the hydrate surface and in the bulk solution. In this case, a solubility-controlled boundary layer model (mass transfer limited) was able to predict the dissociation data. The results showed that carbon dioxide hydrate dissociated much more rapidly than methane hydrate due to the higher solubility in water of carbon dioxide compared to methane. 

There are only few data sets of aqueous solubility for systems with hydrates (1) methane and ethane solubility in water as a function of temperature ramping rate (Song et al. 1997), (2) carbon dioxide solubility in water by Yamane and Aya (1995), (3) methane in water and in seawater (Besnard et al., 1997), (4) methane in water in Lw-H region [see Servio and Englezos (2002) and Chou and Burruss, Personal Communication, December 18,2006, Chapter 6], As a standard for comparison, Handa s (1990) calculations for aqueous methane solubility are reported in Table 4.3. 

Synonyms methanal, methylene oxide, oxymethane Formula HCHO MW 30.03 CAS[50-00-0] constitutes about 50% of all aldehydes present in air released in trace quantities from pressed wood products, burning wood, and synthetic polymers and automobiles colorless gas at ambient conditions pungent suffocating odor liquefies at -19.5°C solidifies at -92°C density 1.07 (air = 1) very soluble in water, soluble in organic solvents readily polymerizes flammable, toxic, and carcinogenic (Patnaik, 1992). 

Methane (CH4, marsh gas, fire damp, melting point -182.6°C, boiling point -161.4°C, density 0.415 at -164°C) is a colorless, odorless that is only very slightly soluble in water and moderately soluble in alcohol or ether. When ignited, the gas burns when ignited in air with a pale, faintly luminous flame. It forms an explosive mixture with air between gas concentrations of 5 and 13%. 

The fascination with the abundances of the atomic nuclei is that they inform of ancient events. The events that are recorded in their populations depend upon the material sample in question. In the crust of the Earth, they record its geologic evolution. Silicon in that crust is much more abundant than iron, for example, because the Earth s crust is sandy, whereas its iron sank to the Earth s core during its early molten state. In the Earth s oceans the elemental abundances reflect their solubilities in water. In the Earth s atmosphere, their numbers reflect their volatilities. And so it goes. Such abundance-sets reflect and record the geophysical history of the Earth and the chemical properties of the chemical elements. Atmospheric carbon dioxide (C02) and methane (CH4) record an extra wrinkle, the impact of human beings on the Earth s atmosphere. 

Nitromethane is sparingly soluble in water. The compound is of industrial interest as a solvent rather than as an explosive. Its technical synthesis involves nitration of methane with nitric acid above 400 °C (750 °F) in the vapor phase. 

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