نتایج جستجو برای: ch4 purification
تعداد نتایج: 63718 فیلتر نتایج به سال:
abstract in this work, the dry reforming of methane was studied using a corona and glow discharge plasma microreactors. a chemical kinetic model was developed to understand the reaction better. the modelization allowed prediction of the reactants conversion according to the energy transfer to the gas (p×τ). the β value is trait of the energy cost, whatever this value was leeser indicated better...
We describe an assimilation system for atmospheric methane (CH4), CarbonTracker-CH4, and demonstrate the diagnostic value of global or zonally averaged CH4 abundances for evaluating the results. We show that CarbonTracker-CH4 is able to simulate the observed zonal average mole fractions and capture inter-annual variability in emissions quite well at high northern latitudes (53–90 N). In contras...
Atmospheric methane (CH4) varied with climate during the Quaternary, rising from a concentration of 375 p.p.b.v. during the last glacial maximum (LGM) 21,000 years ago, to 680 p.p.b.v. at the beginning of the industrial revolution. However, the causes of this increase remain unclear; proposed hypotheses rely on fluctuations in either the magnitude of CH4 sources or CH4 atmospheric lifetime, or ...
Considering their contribution to global warming, the sources and sinks of methane (CH4) should be accounted when undertaking a greenhouse gas inventory for grazed rangeland ecosystems. The aim of this study was to evaluate the mitigation potential of current ecological management programs implemented in the main rangeland regions of China. The influences of rangeland improvement, utilization a...
Three diel field campaigns and one monthly sampling campaign during June 2010-May 2011 were carried out to investigate the CH4 flux across the water-gas interface in Xiangxi Bay of the Three Gorges Reservoir, China. The average CH4 flux was much less than that reported from reservoirs in tropic and temperate regions. The photosynthesis of phytoplankton dominated the diel gas fluxes during alga ...
Although bubble ebullition through water in rice paddy fields dominates direct methane (CH4) emissions from paddy soil to the atmosphere in tropical regions, the temporal changes and regulating factors of this ebullition are poorly understood. Bubbles in a submerged paddy soil also contain high concentrations of carbon dioxide (CO2), implying that CO2 ebullition may occur in addition to CH4 ebu...
Methylobacterium organophilum CZ-2 synthesized polyhydroxyalkanoates (PHAs) under nitrogen limitation with CH4 as carbon source and when either citrate or propionate was added as cosubstrates. The highest PHAs content (yPHA) in closed flasks was obtained in the CH4-citrate and CH4-propionate experiments attaining values of 0.82 and 0.68, respectively. M. organophilum CZ-2 cultivated in bioreact...
Microbial production in anoxic wetland rice soils is a major source of atmospheric CH4 the most important non-CO2 greenhouse gas. Much higher CH4 emissions from well managed irrigated rice fields in the wet than in the dry season could not be explained by seasonal differences in temperature. We hypothesized that high CH4 emissions in the wet season are caused by low grain to biomass ratios. In ...
In recent years, methane (CH4) has received increasing scientific attention because it is the most abundant non-CO2 atmospheric greenhouse gas (GHG) and controls numerous chemical reactions in the troposphere and stratosphere. However, there is much that is unknown about CH4 sources and sinks and their evolution over time. Here we show that near-surface cavities in the uppermost vadose zone are...
The objectives of this study were to investigate the individual variation, repeatability and correlation of methane (CH4) production from dairy cows measured during 2 different years. A total of 21 dairy cows with an average BW of 619 ± 14.2 kg and average milk production of 29.1 ± 6.5 kg/day (mean ± s.d.) were used in the 1st year. During the 2nd year, the same cows were used with an average B...
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