Natural methane

Methane (CH4), the Earth s third most important greenhouse gas (behind water vapor and CO2) is produced almost exclusively by terrestrial sources (see Chapters 7 and 11). Natural methane sources include anaerobic microbial... 

Longer ice-core records show that methane concentrations have varied on a variety of time scales over the past 220 000 years (Fig. 18-15) Qouzel et al, 1993 Brook et al, 1996). Wetlands in tropical (30° S to 30° N) and boreal (50° N to 70° N) regions are the dominant natural methane source. As a result, ice-core records for preanthropogenic times have been interpreted as records of changes in methane emissions from wetlands. Studies of modem wetlands indicate that methane emissions are positively correlated with temperature, precipitation, and net ecosystem productivity (Schlesinger, 1996). 

Gas hydrates are non-stoichiometric crystals formed by the enclosure of molecules like methane, carbon dioxide and hydrogen sulfide inside cages formed by hydrogen-bonded water molecules. There are more than 100 compounds (guests) that can combine with water (host) and form hydrates. Formation of gas hydrates is a problem in oil and gas operations because it causes plugging of the pipelines and other facilities. On the other hand natural methane hydrate exists in vast quantities in the earth s crust and is regarded as a future energy resource. 

Coalbed Methane (CBM) A natural methane gas that is found in coal seams, while traditional natural gas deposits are trapped in porous rock formations. A small amount of CBM is already produced successfully in the Rocky Mountain region of the U.S. 

High-temperature oxidation of natural methane with hydrogen peroxide... 

There also are major sources of organic compounds from nature. Methane is a major emission from the natural environment and in non-urban atmospheres concentrations generally range between 1-1.5 ppm (6). The major source of atmospheric methane is the decomposition of organic material in swamps, marshes, and other bodies of water. Natural gas seepage possibly significantly contributes methane to the atmosphere in certain petroleum areas. It is estimated that natural sources of methane are about 1600 X 10 tons annually (7). 

Methane hydrate is a clathrate compound of water molecules surrounding a methane molecule. Natural methane hydrate is found in permafrost and deep-sea sediment, and has recently attracted much attention as a potential new resource because of the large amount of deposits. Methane hydrate is also expected as new materials for gas storage and transportation due to its unique properties called anomalous preservation, quite slow dissociation from -40 to -10°C at atmospheric pressure, despite of its dissociation over -80"C. ... 

One of several applications of the above catalysts is the production of the high octane ethers, MTBE and TAME, which are increasingly in demand as blend stocks for unleaded gasoline. The concept of the process is outlined in figure 3. Synthesis gas from natural methane would be converted by an alkene selective catalyst. The butene and pentene could then be isomerized by the... 

Boles, J.R., Clark, J.F., Leifer, I. and Washburn, L. (2001) Temporal variation in natural methane seep rate due to tides, Coal Oil Point area, California. Journal of Geophysical Research, 106(C11), 27077-27086. 

Color-coding the balls distinguishes one type of matter from another the geometrical form of the model, all of the angles and dimensions of a tetrahedron, are the same for each methane unit found in nature. Methane is certainly not a collection of balls and sticks but such models are valuable because they help us understand the chemical behavior of methane and other, more complex substances. 

The two identical nozzles and their dimensions described previously [2] had contractions of area ratio 9.0 and followed a fifth-order polynomial [3] to a diameter of 25 mm. Fig. 6.1. The nozzle separation was varied between 0.2 and 2.0 exit diameters with bulk velocities from 1.49 to 7.00 m/s, and, since these velocities corresponded to Reynolds numbers of 2,000 and 10,000, a perforated plate was located at the end of the contraction with 4-millimeter diameter holes and 50% solidity. A subsequent straight pipe, two exit diameters in length, allowed the wakes to diminish and the small-scale turbulence to develop [4]. The two jets were mounted on a frame that allowed the separation to be varied while maintaining the same geometric axis. The compressed air and gas supply of natural methane was filtered, and the flow was measured with calibrated rotameters to accuracy better than 3%, while the centerline velocities were matched within 0.1 m/s. 

An annular thermal diffusion column with a large reservoir at the top is to be used to enrich by thermal diffusion of natural methane containing 1.1 percent CH4. The column is operated at total reflux until a steady state is reached. Dimensions, operating conditions, and properties of methane are as follows ... 

Gutt, C., Asmussen, B., Press, W., Merkl, C., Casalta, H., Greinert, J., Bohrmann, G, Tse, J., and Hiiller, A., 1999. Quantum rotations in natural methane-clathrates from the Pacific sea-floor. Europhysics... 

Fig. 1 Methane hydrate, which is stable belou- and to the left of the phase boundary line. Also shovra is the geothermal gradient in permafrost as well as marine environments. Where the curves intersect, natural methane hydrate is stable. Natural methane hydrates are found in the lightly shaded region. BSR labels the "bottom-simulating reflector." an unexpected interface found by sonic exploration techniques and usually associated with the interface between sediments with and without hydrate. View this art in color at...

Resin, Polyester 911 (Russian) n 631-2707 Rubber, Natural Methane m 631-1132... 

The author has followed and used the four rules in his scientific inquiry of the nature of the Earth s interior. Therefore, he has investigated the 2008 Wenchuan Earthquake (M8.0) and found that the cause of earthquakes is due to the rapid migration and expansion of highly compressed natural (methane) gas from its deep trap in lower crustal rocks with higher compressive pressure into the middle and upper crustal rocks with lower compressive pressures. 

Combustion reactions are exothermic reactions that require fuel, oxygen, and heat to occur. In this type of reaction, oxygen reacts with another material so rapidly that fire is created. A fired furnace or a boiler is an example of a device that uses combustion reaction. Natural methane gas is pumped to the burner, mixed with oxygen, and ignited. This type of reaction can be represented by the following chemical equation ... 

The majority of natural methane and carbon dioxide in peat and alluvium has already been generated and is largely trapped in the soil. It therefore represents a finite source and the likely risk is related to the volume present in the ground and factors that could affect surface emissions such as variations... 

Fuel Types Coal bituminous, brown Oil No. 6 Gas natural, methane, refinery, organic Pulp and paper wood, wood waste, bark, paper sludge, black liquor, hog fuel Miscellaneous municipal solid waste, tires, coke, contaminated solids... 

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