Polar ice-core records suggest that an arctic or boreal source was responsible for more than 30% of the large increase in global atmospheric methane (CH4) concentration during deglacial climate warming; however, specific sources of that CH4 are still debated. Here we present an estimate of past CH4 flux during deglaciation from bubbling from thermokarst (thaw) lakes. Based on high rates of CH4 ...

ch4, c2h6 and c2h4 are the most important outlet gaseous of oxidative couple methane (ocm) reaction and this process is a new technology for conversion of natural gas to ethane and ethylene products. in this study, adsorption of ocm outlet hydrocarbons over 10x zeolite has been examined at equilibrium conditions. temperature and pressure are the most effective operational parameters in the batc...

The increase in environmental problems and the shortage of fossil fuels have led to the need for action in the development of sustainable and renewable fuels. Methane is produced through anaerobic digestion of organic materials and is a biofuel with very promising characteristics. The success in using methane as a biofuel has resulted in the operation of several commercial-scale plants and the ...

A laboratory procedure is described for measuring methane potentials of organic solid waste. Triplicate reactors with 10 grams of volatile solids were incubated at 55 degrees C with 400 ml of inoculum from a thermophilic biogas plant and the methane production was followed over a 50-day period by regular measurements of methane on a gas chromatograph. The procedure involves blanks as well as ce...

Soil moisture strongly controls the uptake of atmospheric methane by limiting the diffusion of methane into the soil, resulting in a negative correlation between soil moisture and methane uptake rates under most non-drought conditions. However, little is known about the effect of water stress on methane uptake in temperate forests during severe droughts. We simulated extreme summer droughts by ...

[1] Much progress has been made in methane modeling for the Arctic. However, there is still large uncertainty in emissions estimates due to the spatial variability in water table depth resulting from complex topographic gradients, and due to variations in methane production and oxidation due to complex freezing and thawing processes. Here we extended an extant methane emission module within a b...

Moderate elevated vertical methane (CH4) flux is associated with sediment accretion and raised fluid expulsion at the Hikurangi subduction margin, located along the northeast coast of New Zealand. This focused CH4 flux contributes to the cycling of inorganic and organic carbon in solid phase sediment and pore water. Along a 7 km offshore transect across the Porangahau Ridge, vertical CH4 flux r...

Methane (CH4) emissions via emergent aquatic macrophytes can contribute substantially to the global CH4 balance. We addressed temporal variability in CH4 flux by using the static chamber approach to quantify fluxes from plots dominated by two species considered to differ in flux transport mechanisms (Phragmites australis, Carex rostrata). Temporal variability in daily mean emissions from early ...

Recent observations have evidenced traces of methane (CH4) heterogeneously distributed in the martian atmosphere. However, because the lifetime of CH4 in the atmosphere of Mars is estimated to be around 300–600 years on the basis of photochemistry, its release from a subsurface reservoir or an active primary source of methane have been invoked in the recent literature. Among the existing scenar...

in this study, a novel solid dendrimer amine (hyperbranched polymers) was prepared using mesoporous carbon nitride functionalized by melamine based dendrimer amines. this adsorbent was denoted mda-mcn-1. the process was stepwise synthesis and hard-templating method using mesoporous silica sba-15 as a template. cyanuric chloride and n,n-diisopropylethylamine (dipea, merck) were used for function...