Methane residual atmosphere

Gas emerges from each expander cooled to -61°C (-77°F). Additional heat exchangers lower the temperature to -84°C (-120°F), at which point all the LNG is removed for delivery. Residue gas, now under reduced pressure, is passed along to the nitrogen rejection unit (NRU) where inert nitrogen is separated and vented into the atmosphere. Helium is also recovered in the NRU. The remaining residue gas is 90% methane. 

G. A. White We have looked at a case consisting of a Koppers-Totzek gas, at essentially atmospheric pressure, in combination with the COED liquefaction process. We considered the residue gas that came from gasification at atmospheric pressure, methanated it at atmospheric pressure, and took out C02 at atmospheric pressure before compression. That was the minimum cost for our system. It is obvious that each system will have some difference in economics, depending on what you can achieve by methanation. 

The MDA experiments were performed in a continuous down-flow fixed bed reactor at 700°C, atmospheric pressure, and a space velocity of 1500 em3/(gcat h). Catalysts were pretreated in He flow at 700°C for 30 min before feeding a CH4 N2 mixture in a 9 1 voEvol ratio (N2 used as internal standard). Unreacted methane, the reference N2, and the reaction products were analyzed on line in a gas chromatograph (HP-GC6890) as detailed in [6]. Product selectivities are given on a carbon basis. The use of N2 as internal standard allows to obtain the amount of carbonaceous residues as the amount of carbon required to close the mass carbon balances to 100%. 

Krypton is the 81st most abundant element on Earth and ranks seventh in abundance of the gases that make up Earths atmosphere. It ranks just above methane (CH ) in abundance in the atmosphere. Krypton is expensive to produce and thus has hmited use. The gas is captured commercially by fractional distillation of liquid air. Krypton shows up as an impurity in the residue. Along with some other gases, it is removed by filtering through activated charcoal and titanium. 

Erythro- and Threo-2-( 1 -Hydroxybenzyl)cyclohexanones. A dichloro-methane (10 ml) solution of 1-trimethylsilyloxycyclohexene (0.426 g, 2.5 mmol) is added dropwise into a mixture of benzaldehyde (0.292 g, 2.75 mmol) and titanium(iv) chloride (0.55 g, 2.75 mmol) (2) in dry dichloro-methane (20 ml) under an argon atmosphere at — 78 °C, and the reaction mixture is stirred for 1 hour. After hydrolysis (with water) at that temperature, the resulting organic layer is extracted with ether, and the extract is washed with water and dried over anhydrous sodium sulphate. The extract is evaporated under reduced pressure, and the residue is purified by column chromatography (silica gel). Elution with dichoromethane affords 115 mg (23%) of eryt/jro-2-(r-hydroxybenzyl)cyclohexanone, m.p. 103 °C (recrystallised from propan-2-ol, m.p. 103.5-104.5 °C) i.r. 3530 (OH), 1700 (C=0)... 

Fig. 10. Some monthly averaged observed distributions of atmospheric methane from the SAMS satellite, Jones and Pyle, near solstice conditions, compared to the model distribution for July by Solomon and Garcia. Light dashed arrows indicate the residual Eulerian stream function, showing the advection pattern.

The CALCOR process is similar to a conventional steam methane reformer with an amine acid gas removal system, except that the CO2 from the amine system is recycled to the reformer furnace. The reformer operates at a very low pressure to reduce reforming severity. The synthesis gas from the CO2 removal system is just above atmospheric pressure. It is saturated with water and residual CO2 and must be compressed before entering downstream separation equipment. The process features a very low methane slip below 500 ppm in the synthesis gas [11]. 

Peat is a high carbon content residue resulting from the decomposition of plants by the action of water. It can contain up to 85 or 90% water, but on drying to around 40% water it serves as a fuel or source of hydrocarbons (including methane gas which it also evolves as it is dried). Peat oxidizes in the atmosphere to the point of self-heating (evolving carbon dioxide) or spontaneous combustion. It can also generate explosive concentrations of dust. 

Metzger, R. A. and G. Benford (2001) Sequestering of atmospheric carbon through permanent disposal of crop residue. Climatic Change 49, 11-19 Mihalopoulos, N., J. P. Putand and N. C. Ngyen (1993) Seasonal variation of methane sulfonic acid in precipitation at Amsterdam Island in the southern Indian ocean. Atmospheric Environment 27, 2069-2073... 

The atmospheric residues (samples 14-17) demonstrate the same mean of the quotient, x = 0.93, for the reactions both in argon and in methane. The high weight loss due to evaporation may have influenced the values of the ratio. 

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