NORMAN, OKLA. - A University of Oklahoma-led study shows that paddy rice (both area and plant growth) is significantly related to the spatial-temporal dynamics of atmospheric methane concentration in monsoon Asia, where 87% of paddy rice fields are situated in the world.. Methane is one of the major greenhouse gases. It has a lifetime of 12.4 years and its global warming potential is approximately 86 times higher than carbon dioxide over a 20-year period.. Rice paddy is a large source of methane emission; however, it has been a challenging task to attribute relative role of rice paddy in the spatial distribution, seasonal dynamics and interannual variation of atmospheric methane concentration as measured by spaceborne sensors, said Xiangming Xiao, a member of the Earth Observation and Modeling Facility at OU and a professor in the Department of Microbiology and Plant Biology who coordinated this interdisciplinary study.. Over the past few years, researchers at OU developed annual paddy rice ...
Anaerobic bacterial metabolism in the colon produces hydrogen, methane, volatile fatty acids and carbon dioxide. Hydrogen and methane are excreted in flatus and the expired breath. Investigations in this Thesis attempted to identify factors which may influence methane excretion in man and explain why all subjects do not excrete methane. The proportions of methane producing subjects in two healthy populations studied in Edinburgh were 33% and 70% respectively. Age and sex did not significantly alter methane excretion. Dietary intakes, faecal components and bowel function were found to be similar in methane producing and non-methane producing subjects. An association was found between the ingestion of the pentose fraction of non-cellulosic polysaccharides and the concentration of breath methane in methane producing subjects. This association may be the result of a steady metabolic state in the caecum. Ingestion of pentose monomers D(+) xylose and L(+) arabinose increased methane excretion, in ...
An interesting correlation between methane production rates and archaea cell density during anaerobic digestion with increasing organic loadingAn interesting correlation between methane production rates and archaea cell density during anaerobic digestion with increasing organic loading ...
The global methane cycle includes both terrestrial and atmospheric processes and may contribute to feedback regulation of the climate. Most oxic soils are a net sink for methane, and these soils consume approximately 20 to 60 Tg of methane per year. The soil sink for atmospheric methane is microbially mediated and sensitive to disturbance. A decrease in the capacity of this sink may have contributed to the similar to 1%.year(-1) increase in the atmospheric methane level in this century. The organisms responsible for methane uptake by soils (the atmospheric methane sink) are not known, and factors that influence the activity of these organisms are poorly understood. In this study the soil methane-oxidizing population was characterized by both labelling soil microbiota with (CH4)-C-14 and analyzing a total soil monooxygenase gene library. Comparative analyses of [C-14]phospholipid ester-linked fatty acid profiles performed with representative methane-oxidizing bacteria revealed that the soil sink ...
TY - JOUR. T1 - Effects of triclosan, diclofenac, and nonylphenol on mesophilic and thermophilic methanogenic activity and on the methanogenic communities. AU - Symsaris, Evangelos C.. AU - Fotidis, Ioannis. AU - Stasinakis, Athanasios S.. AU - Angelidaki, Irini. PY - 2015. Y1 - 2015. N2 - In this study, a toxicity assay using a mesophilic wastewater treatment plant sludge-based (SI) and a thermophilic manure-based inoculum (MI), under different biomass concentrations was performed to define the effects of diclofenac (DCF), triclosan (TCS), and nonylphenol (NP) on anaerobic digestion (AD) process. Additionally, the influence of DCF, TCS, and NP on the relative abundance of the methanogenic populations was investigated. Results obtained demonstrated that, in terms of methane production, SI inoculum was more resistant to the toxicity effect of DCF, TCS, and NP, compared to the MI inoculum. The IC50 values were 546, 35, and 363mgL-1 for SI inoculum and 481, 32, and 74mgL-1 for MI inoculum for DCF, ...
Henkel, Susann; Schwenk, Tilmann; Hanebuth, Till J J; Strasser, Michael; Riedinger, Natascha; Formolo, Michael J; Arnold, Gail Lee; Tomasini, Juan; Krastel, Sebastian; Kasten, Sabine (2012): Sulfate and methane concentrations measured in pore water of sediment core GeoB13809-1 and GeoB13849-1. PANGAEA, https://doi.org/10.1594/PANGAEA.773289, Supplement to: Henkel, S et al. (2012): Pore water geochemistry as a tool for identifying and dating young mass-transport deposits. In: Yamada, Y et al. (eds.) Advances in Natural and Technological Hazards Research - Submarine Mass Movements and Their Consequences, 5th International Symposium, Springer, 31(1), 87-97, https://doi.org/10.1007/978-94-007-2162-3_8
Öfele and Wanzlick first pioneered the metalation of imidazol-2-ylidenes, better known as N-heterocyclic carbenes (NHCs), from imidazolium salts in 1968.1,2 Lappert and co-workers followed this work with the investigation of N-heterocyclic carbene complexes synthesized from electron-rich olefins.3,4 However, it was not until the isolation of the first free carbene by Arduengo, in 1991, that significant interest was given to the area.5 Since then the complexation chemistry of these new ligands has become a major area of research.6-10 This new class of ligand has shown to equal, if not exceed, phosphines in their ability to bind to a variety of metals. Complexes of N-heterocyclic carbenes with virtually every transition metal and many main group elements have been reported.1-10 N-Heterocyclic carbenes bind to both hard and soft metals making it a very versatile ligand system. NHCs bond to metals primarily through σ donation of the carbene lone pair to the metal. The bonding of the carbene was believed
Methane is a flammable gas that is the main component of natural gas. It is a highly potent greenhouse gas, and accounts for about 20% of greenhouse gas emissions. Methane is routinely flared in many industrial processes without harnessing any of its energy. The environmental impact and wasted energy potential make it highly desirable to find an economically feasible process to use this methane.One possibility is to convert methane into liquid fuels for transportation and energy generation. Current technologies to convert methane gas to liquid fuels (GTL) are complex, and the facilities are only economical at huge scales. Methane gas is very difficult to transport and store, so GTL plants must be located at the source of the methane, typically at large petroleum fields or refineries.Biological conversion of methane to liquid fuels is an attractive alternative to traditional GTL processes, as microbial oxidation of methane can produce liquid fuels (e.g. methanol) at ambient temperatures and ...
TY - JOUR. T1 - High rates of anaerobic methanotrophy at low sulfate concentrations with implications for past and present methane levels. AU - Beal, EJ. AU - Claire, MW. AU - House, CH. PY - 2011/3. Y1 - 2011/3. N2 - Despite the importance of the anaerobic oxidation of methane (AOM) to global biogeochemical cycles, the relationship between sulfate concentration and the rate of AOM has not been previously experimentally constrained. Here, we present measurements showing substantial methane oxidation at low sulfate concentrations, with no significant decrease in the rate of AOM until sulfate levels are well below 1 mm. At sulfate levels below 1 mm, there appears to be a strong decoupling of AOM and sulfate reduction, with a 13C-label transferred from methane to carbon dioxide occurring at a rate almost an order of magnitude faster than the observed rate of sulfate reduction. These results allow for the possibility that high rates of AOM occurred in the Archean oceans and that high rates of AOM ...
This paper examines the effect of particle sizes in substrates on methane production yields of wheat and rice straw biomass without any other applied pretreatment. Anaerobic digestion of three different mean particle size (MPS) substrate of 1.5 mm, 0.75 mm, and 0.30 mm of wheat and rice straw biomass was carried out at 37 oC mesophilic temperature. The observed result revealed that mean particle size of 0.30 mm, and 0.75 mm had increased methane production yield by 4.7%, and 38.7%, respectively, compared to 1.50 mm particle size of wheat straw. However, in case of rice straw substrates the methane production yield was found 7.9%, and 13.0% higher, respectively, for mean particle size of 0.30 mm, and 0.75 mm, compared to 1.50 mm particle size. Mean particle size of 0.75 mm had yielded highest biogas as well as methane yields in both cases of biomass, however, wheat straw resulted into considerably higher methane yield than rice straw.. ...
The Potential to Feed Nitrates to Reduce Enteric Methane Production in Ruminants. By R A Leng AO, D.Rur.Sc. Emeritus Professor UNE-Armidale. The issues in a nut shell 1. Globally ruminants produce around 80x10 6 tonnes of methane Slideshow 1284979 by gigi
Methane is metabolized principally by methanotrophs and methanogens in the global carbon cycle. Methanotrophs consume methane as the only source of carbon, while methanogens produce methane as a metabolic byproduct. Methylotrophs, which are microorganisms that can obtain energy for growth by oxidizing one-carbon compounds, such as methanol and methane, are situated between methanotrophs and methanogens. Methanogens can obtain energy for growth by converting a limited number of substrates to methane under anaerobic conditions. Three types of methanogenic pathways are known: CO2 to methane [MD:M00567], methanol to methane [MD:M00356], and acetate to methane [MD:M00357]. Methanogens use 2-mercaptoethanesulfonate (CoM; coenzyme M) as the terminal methyl carrier in methanogenesis and have four enzymes for CoM biosynthesis [MD:M00358]. Coenzyme B-Coenzyme M heterodisulfide reductase (Hdr), requiring for the final reaction steps of methanogenic pathway, is divided into two types: cytoplasmic HdrABC in ...
Please take a moment to fill out a short, 5 minute evaluation of the Global Methane Forum. Your feedback will help determine how GMI plans its future meetings.. The Global Methane Initiative (GMI) and the Climate and Clean Air Coalition (CCAC) were pleased to welcome more than 500 attendees from 62 countries to Washington, DC for the Global Methane Forum and CCAC Working Group meetings. Methane experts and policy-makers from around the world gathered to discuss options for methane reduction and abatement activities.. This unique opportunity granted access to:. ...
Methane is metabolized principally by methanotrophs and methanogens in the global carbon cycle. Methanotrophs consume methane as the only source of carbon, while methanogens produce methane as a metabolic byproduct. Methylotrophs, which are microorganisms that can obtain energy for growth by oxidizing one-carbon compounds, such as methanol and methane, are situated between methanotrophs and methanogens. Methanogens can obtain energy for growth by converting a limited number of substrates to methane under anaerobic conditions. Three types of methanogenic pathways are known: CO2 to methane [MD:M00567], methanol to methane [MD:M00356], and acetate to methane [MD:M00357]. Methanogens use 2-mercaptoethanesulfonate (CoM; coenzyme M) as the terminal methyl carrier in methanogenesis and have four enzymes for CoM biosynthesis [MD:M00358]. Coenzyme B-Coenzyme M heterodisulfide reductase (Hdr), requiring for the final reaction steps of methanogenic pathway, is divided into two types: cytoplasmic HdrABC in ...
TY - JOUR. T1 - Communal metabolism by Methylococcaceae and Methylophilaceae is driving rapid aerobic methane oxidation in sediments of a shallow seep near Elba, Italy. AU - Taubert, Martin. AU - Grob, Carolina. AU - Crombie, Andrew. AU - Howat, Alexandra. AU - Burns, Oliver. AU - Weber, Miriam. AU - Lott, Christian. AU - Kaster, Anne-Kristin. AU - Vollmers, John. AU - Jehmlich, Nico. AU - von Bergen, Martin. AU - Chen, Yin. AU - Murrell, Colin. PY - 2019/10. Y1 - 2019/10. N2 - Release of abiotic methane from marine seeps into the atmosphere is a major source of this potent greenhouse gas. Methanotrophic microorganisms in methane seeps use methane as carbon and energy source, thus significantly mitigating global methane emissions. Here we investigated microbial methane oxidation at the sediment-water interface of a shallow marine methane seep. Metagenomics and metaproteomics, combined with 13C-methane stable isotope probing, demonstrated that various members of the gammaproteobacterial family ...
Communications Sterically Flexible Carbene Ligands An N-Heterocyclic Carbene Ligand with Flexible Steric Bulk Allows Suzuki Cross-Coupling of Sterically Hindered Aryl Chlorides at Room Temperature ** Gereon Altenhoff, Richard Goddard, Christian W. Lehmann, and Frank Glorius* However, despite considerable efforts, the coupling of aryl chlorides to give biaryl compounds with more than one ortho substituent at room temperature has not been realized to date.[7] To overcome this problem, an electron-rich ligand is required that is small enough to accept sterically hindered substrates yet sufficiently bulky to support monoligation and promote reductive elimination. We rationalized that these stringent requirements could be met by new NHC 1, which exhibits flexible steric bulk. Imidazolium salt 4 (Scheme 1) and the corresponding NHC 1 derived thereof are expected to exist in the form of three different conformers a, b and c. Conformation a should allow the coordinated Pd0 to undergo oxidative addition, ...
A map of Porter Ranch methane levels (Image: Rob Jackson, Nathan Phillips, and Bob Ackley). Its been three months since Southern California Gas Co. first reported a massive leak in its Aliso Canyon gas field, on the edge of Los Angeles, and the faulty well is still pouring methane into the air. If you look at the map above, of Porter Ranch, the neighborhood where thousands of people have been displaced, and of methane levels measured in the area, you can roughly guess where the leak is.. This map was created by Rob Jackson, a scientist at the Stanford Woods Institute for the Environment, and his colleagues Nathan Phillips, a professor at Boston University, and Bob Ackley. Recently, they took a tool they use regularly in their research-a very accurate laser-based methane detector-and spent a weekend sampling methane in Porter Ranch. The red line shows the path they drove around the neighborhood, and its height indicates the amount of methane measured.. As Jackson writes, in a post on Medium, ...
The Pd-catalysed asymmetric intramolecular α-arylation of amideenolates containing heteroatom substituents gives chiral 3-alkoxy or 3-aminooxindoles in high yield and with enantioselectivities up to 97% ee when a new chiral N-heterocyclic carbene ligand is used.
On Earth, marine anaerobic methane oxidation (AOM) can be driven by the microbial reduction of sulfate, iron, and manganese. Here, we have further characterized marine sediment incubations to determine if the mineral dependent methane oxidation involves similar microorganisms to those found for sulfate-dependent methane oxidation. Through FISH and FISH-SIMS analyses using 13C and 15N labeled substrates, we find that the most active cells during manganese dependent AOM are primarily mixed and mixed-cluster aggregates of archaea and bacteria. Overall, our control experiment using sulfate showed two active bacterial clusters, two active shell aggregates, one active mixed aggregate, and an active archaeal sarcina, the last of which appeared to take up methane in the absence of a closely-associated bacterial partner. A single example of a shell aggregate appeared to be active in the manganese incubation, along with three mixed aggregates and an archaeal sarcina. These results suggest that the microorganisms
July 20, 2018) On Tuesday, July 17th, ARPA-E held its final MONITOR Annual Meeting in Fort Collins, CO. The MONITOR programs mission was to help fund innovative technologies to cost-effectively and accurately locate and measure methane emissions associated with natural gas production. As one of the MONITOR projects, the Methane Team was invited to share the progress made on their upcoming guidance document. Around 80 people in the natural gas community attended, creating a perfect opportunity for the Methane Team to engage with prospective users! The Methane Team Co-lead Tim Taylor (CDPHE) gave a presentation overviewing ITRC and the Methanes soon-to-be-released guidance document. Later, Tim and ITRC Director Patty Reyes participated in a poster session to interact one-on-one with other MONITOR projects. Both sessions generated an immense amount of interest in the Methane Teams guidance document that will be released this September! The Methane Teams work could not have been accomplished ...
J.U.M. - 109L - Heated Non Methane/ Methane/ Total Hydrocarbon FID Analyzer by J.U.M. Engineering GmbH. The J.U.M 109L is a heated FID analyzer to continuously and simultaneously measure the Methane concentration, the Total Hydrocarbon concentration ...
TY - JOUR. T1 - Different Abilities of Eight Mixed Cultures of Methane-oxidizing Bacteria to Degrade TCE. AU - Broholm, Kim. AU - Christensen, Thomas Højlund. AU - Jensen, Bjørn K.. PY - 1993. Y1 - 1993. N2 - The ability of eight mixed cultures of methane-oxidizing bacteria to degrade trichloroethylene (TCE) was examined in laboratory batch experiments. This is one of the first reported works studying TCE degradation by mixed cultures of methane-oxidizing bacteria at 10°C, a common temperature for soils and groundwaters. Only three of the eight mixed cultures were able to degrade TCE, or to degrade TCE fast enough to result in a significant removal of TCE within the experimental time, when the cultures used methane as growth substrate. The same three mixed cultures were able to degrade TCE when they oxidized methanol, but only for a limited time period of about 5 days. Several explanations for the discontinued degradation of TCE are given. An experiment carried out to re-activate the ...
Effects of feeding different forages on emission of methane in cattle and goats. The objective of this study was to investigate the volumes of methane emission from cattle and goats by feeding Bermuda hay and Alfalfa hay under the condition of closed confinements. Open Path CH4 Analyzer was used to detect methane emissions from these animals. Eight Taiwan yellow cattle and twenty four Taiwan black goats with the same age and body weights were subjected to the trial. Animals were divided into two groups fed with 100% Bermuda hay or the combination of 50% Bermuda and 50% Alfalfa hay. Cattle that received Bermuda hay produced more methane per kg of body weight than those received Bermuda and Alfalfa hay (0.9484 ppb v.s 0.5768 ppb). The similar tendency was found in the goats (7.7405 ppb v.s 7.0782 ppb). Evidences showed that ruminants fed with legume produced resulted in less methane emissions. Meanwhile, goats produced more methane than that of cattle both fed with Bermuda and Alfalfa hay. ...
TY - JOUR. T1 - Catalytic reaction of methane with carbon dioxide over supported palladium. AU - Erdöhelyi, A.. AU - Cserényi, J.. AU - Papp, E.. AU - Solymosi, F.. PY - 1994/2/3. Y1 - 1994/2/3. N2 - The reforming of methane with carbon dioxide has been investigated at 673-773 K on supported palladium catalysts in a fixed-bed continuous-flow reactor. In addition, the dissociation of carbon dioxide and methane, and the reactivity of the surface carbon formed have also been examined. The dissociation of carbon dioxide, detected by infrared spectroscopy, occurred at the lowest temperature, 373 K, on Pd/TiO2. It was greatly promoted by the presence of methane. The decomposition of methane at the temperature of the CH4 + CO2 reaction (ca. 773 K) proceeded initially at a high rate yielding hydrogen and small amounts of ethane and ethene. The deposition of surface carbon was also observed, which was hydrogenated only above 720 K. The reaction between carbon dioxide and methane occurred rapidly above ...
With its capacity for anaerobic methane oxidation and denitrification, the bacterium Methylomirabilis oxyfera plays an important role in natural ecosystems. Its unique physiology can be exploited for more sustainable wastewater treatment technologies. However, operational stability of full-scale bioreactors can experience setbacks due to, for example, bacteriophage blooms. By shaping microbial communities through mortality, horizontal gene transfer, and metabolic reprogramming, bacteriophages are important players in most ecosystems. Here, we analyzed an infected Methylomirabilis sp. bioreactor enrichment culture using (advanced) electron microscopy, viral metagenomics and bioinformatics. Electron micrographs revealed four different viral morphotypes, one of which was observed to infect Methylomirabilis cells. The infected cells contained densely packed ~55 nm icosahedral bacteriophage particles with a putative internal membrane. Various stages of virion assembly were observed. Moreover, during ...
In this paper, we investigate similarities of effects of soil environmental drivers on year-round daily soil fluxes of nitrous oxide and methane for three distinct semi-natural or natural ecosystems: temperate spruce forest, Germany; tropical rain forest, Queensland, Australia; and ungrazed semi-arid steppe, Inner Mongolia, China. Annual cumulative fluxes of nitrous oxide and methane varied markedly among ecosystems, with nitrous oxide fluxes being highest for the tropical forest site (tropical forest: 0.96 kgNha−1 yr−1; temperate forest: 0.67 kgNha−1 yr−1; steppe: 0.22 kgNha−1 yr−1), while rates of soil methane uptake were approximately equal for the temperate forest (−3.45 kgC ha−1 yr−1) and the steppe (−3.39 kgC ha−1 yr−1), but lower for the tropical forest site (−2.38 kgC ha−1 yr−1). In order to allow for cross-site comparison of effects of changes in soil moisture and soil temperature on fluxes of methane and nitrous oxide, we used a normalization approach. ...
Martian methane releases are rare, episodic, and often debated, but scientists have discovered evidence of a methane emission in June 2013, which constitutes the first confirmation of a methane release on Mars.. Planetary Science Institute Senior Scientist Dorothy Z. Oehler is an author on two new papers on methane detections in the Martian atmosphere. The first is Methane spikes, background seasonality and non-detections on Mars: A geological perspective that appears in Planetary Space and Science. Giuseppe Etiope, of the National Institute for Geophysics and Volcanology in Italy, is lead author. The second is Independent confirmation of a methane spike on Mars and a source region east of Gale Crater appearing in Nature Geoscience, on which Marco Giuranna, of the National Institute for Astrophysics in Italy, is lead author ...
Although the effects of elevated ozone on aboveground carbon (C) assimilation are well understood, its effects on soil C fluxes are less certain. Mesocosms taken from a lowland raised bog in northern England were exposed in open-top chambers for 2 years to ambient air or ambient air plus ozone elevated for 8 h day−1 by an average of 49 ppb in summer and 10 ppb in winter. The effects of elevated ozone on methane emission and ecosystem dark respiration were measured throughout this period, along with soil and plant variables. Methane emissions were significantly reduced, by about 25%, by elevated ozone during midsummer periods of both years, but no significant effect of ozone was found during the winter periods. Dark ecosystem respiration was not significantly affected by elevated ozone. There was no evidence that effects of elevated ozone on methane emissions were mediated through changes in aboveground plant biomass or soil water dissolved organic C concentrations. Our results imply that the ...
You are spot on Methane and ethane are excluded, but the only organic compounds come from the natural gas which has methane and ethane (note no mention of propane in the regs). Nat gas has methane and ethane and Bloom is crying that the nat gas has even more ethane than anticipated die to shale gas. This means the remaining organics are methane and some ethane but mostly methane and their VOCs are actually methane and ethane. The fuel cell does not complete the reaction of CH4 to CO2 and H2O and some CH4 will always remain. This is their VOC emissions plus the little ethane that is not converted. Actualy since the pipeline gas is richer in ethane than Bloom anticipated the VOCs may have quite a bit of ethane as well. Bloom data is pretty fake so why would they not fake this as well ...
Forests have long been seen as important sinks, or storage sites, for greenhouse gases. But scientists recently discovered that tree trunks emit methane, a powerful greenhouse gas at least 25 times more potent than carbon dioxide in the short-term.. The discovery comes from researchers at the University of Delaware, who measured methane output from soils, individual trees, and decomposing woody biomass lying on a forest floor in northeast Maryland over a 10-month period. Using a mobile greenhouse gas analyzer, the University of Delaware researchers found that while forest soils suck up and store methane, tree trunks actually release the gas. They also found that different tree species release it at different rates. One theory they posed was that internal rotting or infection inside the tree trunk could cause the methane leaks. The findings were published recently in the journal Ecosystems. When people develop ecosystem to global-scale methane budgets, theres always a chunk in which it is ...
Abstract - Reductions of methane, black carbon and tropospheric ozone could halve warming during the 2030s, while a fairly aggressive strategy to reduce carbon dioxide would do little over the next 20-30 years. Concerning methane, governments must act quickly to take advantage of this opportunity. Production of unconventional natural gas, such as shale gas, has increased significantly and with conventional sources could meet current consumption levels for over 240 years. However, the benefit of methane as a transitional fuel from coal to renewables is questionable due to methane leakage during production. Also, rising temperatures are releasing methane from melting permafrost, but governments are not required to report these emissions. Thus, countries are farther from meeting their targets and the global community is farther from reaching the goal of limiting warming to 2°C above pre-industrial levels than emissions data suggest. This article establishes an agenda for fuller accounting of ...
The surface distribution of CH4, photoproduction capacity of seawater for CO, and CH4 and CO microbial oxidation rates and turnover times were determined for the surface waters of the southeastern Caribbean Sea and Gulf of Paria as affected by the Orinoco River. Measurements were made during the spring (low river flow) and the fall (high river flow) in order to determine the influence of Orinoco River discharge on these parameters. Methane concentrations were generally lower in the fall than in the spring. Low CH4 oxidation rates and similar surface distributions were observed during both seasons. Methane oxidation in the river plume was significantly higher in the fall. Potential CO photoproduction and CO oxidation rates were generally higher during the fall. Possible effects of the Orinoco River on potential CO photoproduction capacity were observed as far as Puerto Rico. Turnover times for CH4 were in the order of years, whereas CO turnover times were in the order of hours. The Orinoco River ...
Researchers say 7,000 methane gas bubbles making the ground wobble in Siberia could explode soon. The gas bubbles like come from melting permafrost.
DENVER (AP) - Over-regulating methane emissions could discourage the use of environment-friendly natural gas, an energy industry representative told the Environmental Protection Agency on Wednesday.. However, a former Colorado air quality official countered that such controls would be a cost-effective way to fight climate change.. [Native Advertisement] The EPA heard radically different views as it opened public hearings in Denver on its proposal to slash allowable methane emissions from oil and gas production. Sessions were also scheduled in Dallas on Wednesday and in Pittsburgh on Sept. 29.. The proposed rules are aimed at cutting the emissions by 40 to 45 percent by 2025 compared with 2012 levels.. Methane is a key component of natural gas and a powerful greenhouse gas that traps heat in the upper atmosphere.. The EPA estimates the new rule would cost industry from $320 million to $420 million annually by 2025 but would reduce health care costs and have other benefits totaling about $460 ...
The Curiosity rover recently detected a background of 0.7 ppb and spikes of 7 ppb of methane on Mars. This in situ measurement reorients our understanding of the Martian environment and its potential for life, as the current theories do not entail any geological source or sink of methane that varies sub-annually. In particular, the 10-fold elevation during the southern winter indicates episodic sources of methane that are yet to be discovered. Here we suggest a near-surface reservoir could explain this variability. Using the temperature and humidity measurements from the rover, we find that perchlorate salts in the regolith deliquesce to form liquid solutions, and deliquescence progresses to deeper subsurface in the season of the methane spikes. We therefore formulate the following three testable hypotheses. The first scenario is that the regolith in Gale Crater adsorbs methane when dry and releases this methane to the atmosphere upon deliquescence. The adsorption energy needs to be 36 kJ/mol to ...
Looking for online definition of Triphenyl methane in the Medical Dictionary? Triphenyl methane explanation free. What is Triphenyl methane? Meaning of Triphenyl methane medical term. What does Triphenyl methane mean?
Methanotrophs are organisms that require methane as a source of carbon and energy for their metabolism. They are gram-negative bacteria that are capable in utilizing methane as a carbon energy source and able to grow both aerobically or anaerobically which only need single-carbon compound to live on. These prokaryotes occur mostly in soils, rice paddles, mud, landfills, and other places where methane is available. They can grow aerobically or anaerobically. In aerobic conditions, they use oxygen and methane to produce formaldehyde. They then incorporate it into organic compounds through ribulose monophosphate pathway or by serine pathway. An example of methanotroph is a gammaproteobacterium that utilize RuMP pathway in assimilating carbon. Such bacteria are referred to as type I methanotrophs. Type II methanotrophs are those from alphaproteobacteria that utilize the serine pathway of carbon assimilation. They have a system of internal membranes where methane oxidation occurs.1 Methanotrophs are ...
Methanotrophs (sometimes called methanophiles) are prokaryotes that metabolize methane as their only source of carbon and energy. They can grow aerobically or anaerobically and require single-carbon compounds to survive. These Methanotrophs are currently being modified to absorb methane from the atmosphere, because methane released into the atmosphere contributes to greenhouse gasses, which heat up the earth and cause global warming. Under aerobic conditions, they combine oxygen and methane to form formaldehyde, which is then incorporated into organic compounds via the serine pathway or the ribulose monophosphate (RuMP) pathway. Type I methanotrophs are part of the Gammaproteobacteria and they use the RuMP pathway to assimilate carbon. Type II methanotrophs are part of the Alphaproteobacteria and utilize the Serine pathway of carbon assimilation. They also characteristically have a system of internal membranes within which methane oxidation occurs. Methanotrophs occur mostly in soils, and are ...
This post was updated on February 10th.. A new study from the U.S. Department of Energy adds to the large and growing body of research on the problem of methane emissions from the oil and gas industry. Methane is both the main component of natural gas and a powerful climate pollutant - which is why regulators, scientists, and industry all have a vested interest in developing a more complete understanding of how much methane is emitted and from which sources.. Researchers with the Department of Energys National Energy Technology Laboratory (NETL) used a life cycle model to integrate data from several of EDFs methane studies, and estimated that 7.3 million metric tons of methane were emitted along the natural gas supply chain in 2012. This value is about 10% higher than the corresponding estimate in the 2016 EPA Greenhouse Gas Inventory (GHGI), although the difference was not statistically significant (the NETL confidence interval ranged from -20% to +30% of the central estimate).. The NETL ...
When fugitive methane gas was detected close to a multi-unit apartment complex, the owner needed environmental consulting services to investigate an orphan natural gas well adjacent to the building. The well was previously discovered and plugged during construction of the apartment complex 12 years prior. However, during a routine service line inspection, natural gas was detected in the area adjacent to the vault containing the natural gas well. The fugitive methane was due to multiple malfunctions, including a leaking water well. The owner evacuated the building as a precautionary measure.. They then contracted with RETTEW to evaluate site conditions and perform emergency repairs within 24 hours. These repairs included installing a sump pump and a blower unit to actively draw and vent methane from the vault. Subsequent investigations included aquifer characterizations, isotopic methane sampling, pilot testing, feasibility analysis, and design and construction of remedial options. RETTEW ...
article{8170967, abstract = {The reaction of [Cp*RuCl](4) (1, Cp* = eta(5)-C5Me5) with the carbene ligand 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes) affords a coordinatively unsaturated Cp*Ru(IMes)Cl (3) complex in 86% isolated yield. Solution calorimetric results in this system provide information concerning the electron donor properties of the carbene ligand, which are very similar to those of PCy3. Structural information from single-crystal X-ray studies for complex 3 allows the determination of steric parameters associated with this ligand. The thermochemical information is used to predict the magnitude of the enthalpic driving force behind substitution reactions involving RuCl2(=C(H)Ph)(PCy3)(2) (1) and the carbene ligand, IMes, affording the RuCl2(=C(H)Ph)(PCy3)(IMes) (6) complex in high yield. A similar mixed carbene/phosphine ruthenium complex, RuCl2(=C(H)Ph)(PPh3)(IMes), can also be isolated from RuCl2(=C(H)Ph)(PPh3)(2) and the IMes ligand. A single-crystal X-ray ...
The identification and quantification of methane emissions from natural gas production has become increasingly important owing to the increase in the natural gas component of the energy sector. An instrumented aircraft platform was used to identify large sources of methane and quantify emission rates in southwestern PA in June 2012. A large regional flux, 2.0-14 g CH4 s-1 km-2, was quantified for a ?2,800-km2 area, which did not differ statistically from a bottom-up inventory, 2.3-4.6 g CH4 s-1 km-2. Large emissions averaging 34 g CH 4/s per well were observed from seven well pads determined to be in the drilling phase, 2 to 3 orders of magnitude greater than US Environmental Protection Agency estimates for this operational phase. The emissions from these well pads, representing ?1% of the total number of wells, account for 4-30% of the observed regional flux. More work is needed to determine all of the sources of methane emissions from natural gas production, to ascertain why these emissions ...
A diverse library of cationic silver complexes bearing bis(N-heterocyclic carbene) ligands have been prepared which exhibit cytotoxicity comparable to cisplatin against the adenocarcinomas MCF7 and DLD1. Bidentate ligands show enhanced cytotoxicity over monodentate and macrocyclic ligands.. ...
This is HUGE ….. In the wake of these startling announcements, wide-ranging discussions have erupted across the Internet concerning the source of this new methane. Probably the most authoritative and fact-based of these is currently taking place on a weblog known by the whimsical title, Mainly Martian. Another cogent analysis is voiced by the Mars Societys Bob Zubrin. As one would expect, viewpoints on this surprising development differ vociferously - mainly, as to whether the new methane measurements are geological or biological.. Fortunately, the scientific test for biological methane in this case is elemental: careful measurement of the ratio of carbon isotopes bound with hydrogen, in the methane molecules detected in the Martian atmosphere.. For a variety of reasons, biologically fixed carbon has a preference for the lighter isotope - Carbon 12 - over the heavier version also found in nature, Carbon 13. Methane produced by non-biologically processes - such as volcanically ...
If AOM Archaea oxidize methane by reverse methanogenesis, coenzyme F430 likely catalyzes the first step. Culture studies of methanogenic Archaea that can carry out trace oxidation of methane provide supporting evidence for a reversed methanogenesis biochemical pathway. The methanogen Methanosarcina acetovorines was shown to oxidize trace amounts of methane to CO2 (Moran et al., 2006) as documented by observations that 13C-labeled methane became incorporated into CO2. Studies of Methanothermobacter marburgensis in pure culture demonstrated the last step in methanogenesis is also the first step in methane oxidation (Scheller et al., 2010) by the incorporation of 13C-labeled methane into methyl-coenzyme M (2-mercaptoethanesulfonate) catalyzed by coenzyme F430. Genetic evidence from environmental samples provides additional support for reverse methanogenesis during AOM. Hallam et al., (2004) found genes that code for the enzymes used in methanogenesis, including for the last step, in ANME-1 and ...
Due to their climate and health impacts, methane emissions have drawn increasing scrutiny from the public, environmental and health groups, and global policymakers. Unfortunately, a dearth of accurate emissions disclosure, conflicting policy stances and variable operational quality of methane management by the industry interfere with investors efforts to gain clarity on climate risks within their portfolios. Without better reporting, investors are unable to discern which operators are prepared for a shifting energy future and which are not, creating an uncertain investment landscape. Understanding the performance of companies on these complex issues can be difficult given the interrelated nature of asks. Additionally, the lack of a goal framework hinders the investors ability to assess a companys progress on methane management and conduct a comparison with other companies. This document aims to tackle these problems by providing guidance to investors in structuring engagements with companies ...
Arctic lakes are a significant source of the greenhouse gas methane (CH4), but the role that methane oxidizing bacteria (methanotrophs) play in limiting the overall CH4 flux is poorly understood. Here, we used stable isotope probing (SIP) techniques to identify the metabolically active aerobic methanotrophs in upper sediments (0-1 cm) from an arctic lake in northern Alaska sampled during ice-free summer conditions. The highest CH4 oxidation potential was observed in the upper sediment (0-1 cm depth) with 1.59 μmol g wet weight-1 day-1 compared with the deeper sediment samples (1-3 cm, 3-5 cm and 5-10 cm), which exhibited CH4 oxidation potentials below 0.4 μmol g wet weight-1 day-1. Both type I and type II methanotrophs were directly detected in the upper sediment total communities using targeted primer sets based on 16S rRNA genes. Sequencing of 16S rRNA genes and functional genes (pmoA and mxaF) in the 13C-DNA from the upper...
The paper itself is a marvel of weak extrapolation:. Link to excerpt of curent Current Biology issue, showing the full article:. http://download.cell.com/current-biology/pdf/PIIS0960982212003296.pdf. Could methane produced by sauropod dinosaurs. have helped drive Mesozoic climate warmth?. David M. Wilkinson1,*, Euan G. Nisbet2, and Graeme D. Ruxton3. Mesozoic sauropods, like many modern herbivores, are likely to have. hosted microbial methanogenic symbionts for the fermentative. digestion of their plant food [1]. Today methane from livestock is a. significant component of the global methane budget [2]. Sauropod. methane emission would probably also have been considerable. Here,. we use a simple quantitative approach to estimate the magnitude of such. methane production and show that the production of the greenhouse. gas methane by sauropods could have been an important factor in warm. Mesozoic climates. Sauropod dinosaurs include the largest terrestrial animals known. and exhibit a ...
UK researchers seeking to cut back on greenhouse gases have found a deliciously potent weapon for fighting agricultural methane emissions: curry. It turns out two spices customarily used to season curry dishes -- coriander and turmeric -- have an antibiotic effect in the stomachs of sheep and cows, killing methane-producing bacteria there. By spicing up animal feeds, farmers could reduce methane emissions from farms by up to 40 percent.
The fifth most abundant gas in the atmosphere is carbon dioxide. The volume of this gas has increased by over 35% in the last three hundred years (see Figure 7a-1). This increase is primarily due to human induced burning from fossil fuels, deforestation, and other forms of land-use change. Carbon dioxide is an important greenhouse gas. The human-caused increase in its concentration in the atmosphere has strengthened the greenhouse effect and has definitely contributed to global warming over the last 100 years. Carbon dioxide is also naturally exchanged between the atmosphere and life through the processes of photosynthesis and respiration.. Methane is a very strong greenhouse gas. Since 1750, methane concentrations in the atmosphere have increased by more than 150%. The primary sources for the additional methane added to the atmosphere (in order of importance) are: rice cultivation; domestic grazing animals; termites; landfills; coal mining; and, oil and gas extraction. Anaerobic conditions ...
By combining fractional amounts of an assumed standard Arctic methane fountain/torch/plume with a global warming potential of 1000 (which equals a 16 oC temperature rise (4 - 20 oC) over one year - 2010 - 2011) with the mean global temperature curve (from IPCC 2007 - gradient data) it was possible to closely match the 5 visually and mathematically determined best estimates of the global extinction gradients shown in Figure 6 (a to e). Because the thermal radiant flux from the earth into space is a function of its area (Lide and Fredrickse, 1995) we can roughly determine how many years it will take for the methane to spread globally by getting the ratio of the determined fraction of the mean global temperature curve to the fraction of the Arctic methane fountain/torch/plume curve, as the latter is assumed to represent only one year of methane emissions. In addition as the earths surface area is some 5.1*10^8 square kilometres (Lide and Fredrickse, 1995) a rough estimate of the average area of ...
EPA has upwardly revised methane emissions from oil and gas production 27 percent, doing so just in time to justify costly new regulations on industry. The new data comes after EPAs previous Greenhouse Gas Inventories consistently showed methane emissions plummeting as natural gas production soars. A close look at the new methods used to revise data for the 2016 GHGI are as flawed as the timing of their release is suspicious.
We herein report that a copper-ion-exchanged erionite zeolite (Cu-ERI) exhibited a methanol yield as high as 147 μmol/g-zeolite, equaling 0.224 μmol/μmol-Cu, in the direct oxidation of methane to methanol. Moreover, this high methanol yield was achieved using an isothermal chemical looping with both oxygen activation and reaction with methane carried out at 300 °C, in contrast to the conventional stepwise protocol where activation is performed at high temperature (450 °C and above) and the methane reaction at lower temperature (typically 200 °C). Under isobaric condition (1 bar), the Cu-ERI still gave a high yield of 80 μmol/g-zeolite after a single aqueous extraction of the methanol. Such improvements indicate that high yields can be obtained over Cu-ERI in the direct conversion of methane to methanol by a chemical looping without any temperature or pressure swing.. ...
Some of these methane emissions come from cow flatulence, exhaling and belching - other livestock animals release methane as well.Cows emit a massive amount of methane through belching, with a lesser amount through flatulence, according to How Stuff Works. Statistics vary regarding how much methane the average dairy cow expels. Some experts say 100 liters to 200 liters a day… while others say its up to 500 liters… a day. In any case, thats a lot of methane, an amount comparable to the pollution produced by a car in a day.Of all domestic animal types, beef and dairy cattle were by far the largest emitters of [methane], according to an EPA analysis charting greenhouse gas emissions in 2012. Cows and other animals produce methane through digestion, which ferments the food of animals.During digestion, microbes resident in an animals digestive system ferment food consumed by the animal, the EPA notes. This microbial fermentation process, referred to as enteric fermentation, produces ...
Keiths update: Press conference statement: \How much methane did we see? So far we have no definitive detection of methane. We have no detection of methane but we will keep looking in the month ahead.\\n\nNASAS Curiosity Rover Provides Clues to Changes in Martian Atmosphere\n\n\Methane is clearly not an abundant gas at the Gale Crater site, if it is there at all. At this point in the mission were just excited to be searching for it,\ said SAM TLS lead Chris Webster of NASAs Jet Propulsion Laboratory (JPL) in Pasadena, Calif. \While we determine upper limits on low values, atmospheric variability in the Martian atmosphere could yet hold surprises for us.\\n\ ...
Methane formed in the ruminant fore-stomach (reticulo-rumen) is a significant source of greenhouse gas emissions for countries that are reliant on ruminant-based agriculture. Methane is an end product of plant digestion in the reticulo-rumen, and is formed by methanogens belonging to the Euryarchaeota subgroup of the Archaea. Molecular surveys of ruminants have shown that small subunit ribosomal RNA gene sequences affiliated with species of the genus Methanobrevibacter predominate in most rumen microbiomes, on average making up almost two thirds of the rumen archaea [1]. Sequences are mainly associated with M. gottschalkii (33.6%) and M. ruminantium (27.3%), but also with M. wolinii (0.1%), M. smithii (0.1%) and other Methanobrevibacter spp. (0.5%). Development of mitigation strategies to reduce methane emissions from farmed animals is currently the subject of both scientific and environmental interest. Methanogens are producers of ruminant methane, therefore methane abatement strategies can ...
Back then we figured that since that eastern Siberian area was one of the shallowest areas of the arctic, it had warmed enough during a period of unusual atmospheric circulation that fall to thaw the extensive amounts of frozen methane hydrates known to be locked up by high pressure and cold temperatures on the ocean floor, and they were melting and rising to the surface. In this case it appears that a branch of the warm gulf stream current is causing enough warming to destabilize the frozen methane on the ocean floor in the areas between Norway and Svalbard and points east. This is similar to a scenario that was warned about in a study in the journal Nature in October ...