Methane abundance

In the early Archean, methanogenesis (reaction of H2 + CO2 to yield CH4) was likely a significant component of total primary production. O2 concentrations in the atmosphere were suppressed due to limited O2 production and rapid consumption with iron, sulfur, and reduced gases, while CH4 concentrations were likely very high (Kasting et al., 2001). The high methane abundance is calculated to have... 

Alkanes have the general molecular formula C H2 +2 The srmplest one methane (CH4) rs also the most abundant Large amounts are present rn our atmosphere rn the ground and rn the oceans Methane has been found on Juprter Saturn Uranus Neptune and Pluto and even on Halley s Comet... 

Natural gas is an abundant source of methane ethane and propane Petro leum IS a liquid mixture of many hydrocarbons including alkanes A1 kanes also occur naturally m the waxy coating of leaves and fruits... 

Cellulose is more abundant than glucose but each cellu lose molecule is a polysac charide composed of thousands of glucose units (see Section 25 15) Methane may also be more abundant but most of the methane comes from glucose... 

Methane. As our most abundant hydrocarbon, methane offers an attractive source of raw material for organic chemicals (see Hydrocarbons). Successful commercial processes of the 1990s are all based on the intermediate conversion to synthesis gas. An alternative one-step oxidation is potentially very attractive on the basis of simplicity and greater energy efficiency. However, such processes are not yet commercially viable (100). 

Within the saturates in petroleum gases and naphtha, except for a few highly branched components in the Cg—C q range, every possible paraffin from methane to normal decane is present. Depending on the source, one of the low hoiling paraffins may be the most abundant compound in a... 

Natural gas, which is mostly methane, CH4, is a resource that die United States has in abundance. In principle, ethane can be obtained from methane by the reaction... 

In the late 1960s, Imperial Chemical Industries (IQ) in the UK were interested in developing an SCP process using abundant and cheap methane from newly developed sources in the North Sea. However, it soon became apparent that methane was unsuitable as a substrate for fermentation. 

The result of the fast reactions in the ion source is the production of two abundant reagent ions (CH5+ and C2H5+) that are stable in the methane plasma (do not react further with neutral methane). These so-called reagent ions are strong Brpnsted acids and will ionize most compounds by transferring a proton (eq. 7). For exothermic reactions, the proton is transferred from the reagent ion to the neutral sample molecule at the diffusion controlled rate (at every collision, or ca. 10 9 s 1). 

What has happened in less than a decade to promote methanation to its existing station We in the United States are beginning to realize or do now realize that we are running out of natural gas (sic methane)— a commodity which we had in abundance but which in less than the age of the Division of Fuel Chemistry, we managed to deplete faster than is possible by nature to replace or by humans to find. 

Methane and the Nonmethane Hydrocarbons. It is traditional to distinguish CH4 from all other atmospheric hydrocarbons. Methane is by far the most abundant atmospheric hydrocarbon and has very large natural emissions. Its abundance in auto exhaust but low atmospheric reactivity has led air pollution scientists to enact controls on nonmethane hydrocarbons NMHC (also called VOC for volatile organic compounds, which include oxygenated hydrocarbons). 

The surface properties of three types of methanation catalysts obtained by oxidation of selected Intermetallics were examined In relation to their CO conversion activity. The first type (Ni Si, N1 A1 ) which corresponds to active phase-supporl iX the coXventionally prepared catalyst Is little affected by the oxidation treatment. The surface Nl is oxidized and relatively more abundant In the active solids. The second type (active phase-promoter ex Ni Th ) is extensively decomposed on oxidation. The transformation of these alloys Is accompanied by a surface enrichment in Nl. 

A long-term goal of our research group is to explore and evaluate novel pathways for the direct conversion of methane to liquid fiiels, chemicals, and intermediates. One of our current areas of research is the conversion of methane to methanol, under mild conditions, using li t, water, and a semiconductor photocatalyst. The use of three relatively abundant... 

The large amounts of natural gas (mainly methane) found worldwide have led to extentive research programs in the area of the direct conversion of methane [1-3]. Ihe oxidative transformation of methane (OTM) is an important route for the effective utilization of the abundant natural gas resources. How to increase catalyst activity is a common problem on the activation of methane. The oxidation of methane over transition m al oxides is always high active, but its main product is CO2, namely the product of deep oxidation. It is because transition metal oxides have high oxidative activity. So, they were usually used as the main corrqtonent of catalysts for the conqilete oxidation of alkane[4]. The strong oxidative activity of CH4 over tran on metal oxides such as NiO indicates that the activation of C-H bond over transition metal oxides is much easier than that over alkaline earth metal oxides and rare earth metal oxides. Furthermore, the activation of C-H bond is the key step of OTM reaction. It is the reason that we use transition metal oxides as the mam conq>onent of the OTM catalysts. However, we have to reahze that the selectivity of OTM over transition metal oxides is poor. 

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