National Library of Energy BETA

Sample records for atmospheric methane ch4

  1. Fundamental Understanding of Methane-Carbon Dioxide-Water (CH4...

    Office of Scientific and Technical Information (OSTI)

    Fundamental Understanding of Methane-Carbon Dioxide-Water (CH4-CO2- H20) Interactions in Shale Nanopores under ReservoirSAND2o 1T-20" if4pe Yifeng Wang, Yongliang Xiong & Louise ...

  2. Fundamental Understanding of Methane-Carbon Dioxide-Water (CH4...

    Office of Scientific and Technical Information (OSTI)

    ...Water (CH4-CO2-H2O) Interactions in Shale Nanopores under Reservoir Conditions. Citation Details In-Document Search Title: Fundamental Understanding of Methane-Carbon Dioxide-Water ...

  3. Fundamental Understanding of Methane-Carbon Dioxide-Water (CH4...

    Office of Scientific and Technical Information (OSTI)

    Fundamental Understanding of Methane-Carbon Dioxide-Water (CH4-CO2-H2O) Interactions in Shale Nanopores under Reservoir Conditions. Citation Details In-Document Search Title:...

  4. Evaluation of wetland methane emissions across North America using atmospheric data and inverse modeling

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Miller, Scot M.; Commane, Roisin; Melton, Joe R.; Andrews, Arlyn E.; Benmergui, Joshua; Dlugokencky, Edward J.; Janssens-Maenhout, Greet; Michalak, Anna M.; Sweeney, Colm; Worthy, Doug E. J.

    2016-03-02

    Existing estimates of methane (CH4) fluxes from North American wetlands vary widely in both magnitude and distribution. In light of these differences, this study uses atmospheric CH4 observations from the US and Canada to analyze seven different bottom-up, wetland CH4 estimates reported in a recent model comparison project. We first use synthetic data to explore whether wetland CH4 fluxes are detectable at atmospheric observation sites. We find that the observation network can detect aggregate wetland fluxes from both eastern and western Canada but generally not from the US. Based upon these results, we then use real data and inverse modelingmore » results to analyze the magnitude, seasonality, and spatial distribution of each model estimate. The magnitude of Canadian fluxes in many models is larger than indicated by atmospheric observations. Many models predict a seasonality that is narrower than implied by inverse modeling results, possibly indicating an oversensitivity to air or soil temperatures. The LPJ-Bern and SDGVM models have a geographic distribution that is most consistent with atmospheric observations, depending upon the region and season. Lastly, these models utilize land cover maps or dynamic modeling to estimate wetland coverage while most other models rely primarily on remote sensing inundation data.« less

  5. Microsoft PowerPoint - New Materials for CH4 Capture-slide_AM [Read-Only]

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    We have discovered a handful of zeolite structures that have sufficient methane (CH 4 ) adsorption capacity as well as appropriate CH 4 /CO 2 and CH 4 /N 2 selectivity to be technologically promising for methane capture from dilute and medium-concentration sources. J Kim, A Maiti, L-C Lin, J Stolaroff, B Smit, R Aines, Nat. Commun. (2013). Doi: 10.1038/ncomms2697 New Materials for Methane Capture from Dilute and Medium-concentration Sources Significance and Impact Methane is an important

  6. Remote Sensing and Sea-Truth Measurements of Methane Flux to the Atmosphere (HYFLUX project)

    SciTech Connect (OSTI)

    Ian MacDonald

    2011-05-31

    , respectively. Based on the contemporaneous wind speeds at this site, contemporary estimates of the diffusive fluxes from the mixed layer to the atmosphere for methane, ethane, and propane are 26.5, 2.10, and 2.78 {micro}mol/m{sup 2}d, respectively. Continuous measurements of air and sea surface concentrations of methane were made to obtain high spatial and temporal resolution of the diffusive net sea-to-air fluxes. The atmospheric methane fluctuated between 1.70 ppm and 2.40 ppm during the entire cruise except for high concentrations (up to 4.01 ppm) sampled during the end of the occupation of GC600 and the transit between GC600 and GC185. Results from interpolations within the survey areas show the daily methane fluxes to the atmosphere at the three sites range from 0.744 to 300 mol d-1. Considering that the majority of seeps in the GOM are deep (>500 m), elevated CH{sub 4} concentrations in near-surface waters resulting from bubble-mediated CH4 transport in the water column are expected to be widespread in the Gulf of Mexico.

  7. Modeling the impediment of methane ebullition bubbles by seasonal lake ice

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Greene, S.; Walter Anthony, K. M.; Archer, D.; Sepulveda-Jauregui, A.; Martinez-Cruz, K.

    2014-07-15

    Microbial methane (CH4) ebullition (bubbling) from anoxic lake sediments comprises a globally significant flux to the atmosphere, but ebullition bubbles in temperate and polar lakes can be trapped by winter ice cover and later released during spring thaw. This "ice-bubble storage" (IBS) constitutes a novel mode of CH4 emission. Before bubbles are encapsulated by downward-growing ice, some of their CH4 dissolves into the lake water, where it may be subject to oxidation. We present field characterization and a model of the annual CH4 cycle in Goldstream Lake, a thermokarst (thaw) lake in interior Alaska. We find that summertime ebullition dominatesmore » annual CH4 emissions to the atmosphere. Eighty percent of CH4 in bubbles trapped by ice dissolves into the lake water column in winter, and about half of that is oxidized. The ice growth rate and the magnitude of the CH4 ebullition flux are important controlling factors of bubble dissolution. Seven percent of annual ebullition CH4 is trapped as IBS and later emitted as ice melts. In a future warmer climate, there will likely be less seasonal ice cover, less IBS, less CH4 dissolution from trapped bubbles, and greater CH4 emissions from northern lakes.« less

  8. Modeling the impediment of methane ebullition bubbles by seasonal lake ice

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Greene, S.; Walter Anthony, K. M.; Archer, D.; Sepulveda-Jauregui, A.; Martinez-Cruz, K.

    2014-12-08

    Microbial methane (CH4) ebullition (bubbling) from anoxic lake sediments comprises a globally significant flux to the atmosphere, but ebullition bubbles in temperate and polar lakes can be trapped by winter ice cover and later released during spring thaw. This "ice-bubble storage" (IBS) constitutes a novel mode of CH4 emission. Before bubbles are encapsulated by downward-growing ice, some of their CH4 dissolves into the lake water, where it may be subject to oxidation. We present field characterization and a model of the annual CH4 cycle in Goldstream Lake, a thermokarst (thaw) lake in interior Alaska. We find that summertime ebullition dominatesmore » annual CH4 emissions to the atmosphere. Eighty percent of CH4 in bubbles trapped by ice dissolves into the lake water column in winter, and about half of that is oxidized. The ice growth rate and the magnitude of the CH4 ebullition flux are important controlling factors of bubble dissolution. Seven percent of annual ebullition CH4 is trapped as IBS and later emitted as ice melts. In a future warmer climate, there will likely be less seasonal ice cover, less IBS, less CH4 dissolution from trapped bubbles, and greater CH4 emissions from northern lakes.« less

  9. An active atmospheric methane sink in high Arctic mineral cryosols

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lau, Maggie C.Y.; Stackhouse, B.; Layton, Alice C.; Chauhan, Archana; Vishnivetskaya, T. A.; Chourey, Karuna; Mykytczuk, N. C.S.; Bennett, Phil C.; Lamarche-Gagnon, G.; Burton, N.; et al

    2015-01-01

    The transition of Arctic carbon-rich cryosols into methane (CH₄)-emitting wetlands due to global warming is a rising concern. However, the spatially predominant mineral cryosols and their CH₄ emission potential are poorly understood. Fluxes measured in situ and estimated under laboratory conditions coupled with -omics analysis indicate (1) mineral cryosols in the Canadian high Arctic contain atmospheric CH₄-oxidizing bacteria; (2) the atmospheric CH⁺ uptake flux increases with ground temperature; and, as a result, (3) the atmospheric CH₄ sink strength will increase by a factor of 5-30 as the Arctic warms by 5-15 °C over a century. We demonstrated that acidic mineralmore » cryosols have previously unrecognized potential of negative CH₄ feedback.« less

  10. An active atmospheric methane sink in high Arctic mineral cryosols

    SciTech Connect (OSTI)

    Lau, Maggie C.Y.; Stackhouse, B.; Layton, Alice C.; Chauhan, Archana; Vishnivetskaya, T. A.; Chourey, Karuna; Mykytczuk, N. C.S.; Bennett, Phil C.; Lamarche-Gagnon, G.; Burton, N.; Renholm, J.; Hettich, R. L.; Pollard, W. H.; Omelon, C. R.; Medvigy, David M.; Pffifner, Susan M.; Whyte, L. G.; Onstott, T. C.

    2015-04-14

    The transition of Arctic carbon-rich cryosols into methane (CH₄)-emitting wetlands due to global warming is a rising concern. However, the spatially predominant mineral cryosols and their CH₄ emission potential are poorly understood. Fluxes measured in situ and estimated under laboratory conditions coupled with -omics analysis indicate (1) mineral cryosols in the Canadian high Arctic contain atmospheric CH₄-oxidizing bacteria; (2) the atmospheric CH⁺ uptake flux increases with ground temperature; and, as a result, (3) the atmospheric CH₄ sink strength will increase by a factor of 5-30 as the Arctic warms by 5-15 °C over a century. We demonstrated that acidic mineral cryosols have previously unrecognized potential of negative CH₄ feedback.

  11. An active atmospheric methane sink in high Arctic mineral cryosols

    SciTech Connect (OSTI)

    Lau, Maggie C.Y.; Stackhouse, B.; Layton, Alice C.; Chauhan, Archana; Vishnivetskaya, T. A.; Chourey, Karuna; Mykytczuk, N. C.S.; Bennett, Phil C.; Lamarche-Gagnon, G.; Burton, N.; Renholm, J.; Hettich, R. L.; Pollard, W. H.; Omelon, C. R.; Medvigy, David M.; Pffifner, Susan M.; Whyte, L. G.; Onstott, T. C.

    2015-01-01

    The transition of Arctic carbon-rich cryosols into methane (CH₄)-emitting wetlands due to global warming is a rising concern. However, the spatially predominant mineral cryosols and their CH₄ emission potential are poorly understood. Fluxes measured in situ and estimated under laboratory conditions coupled with -omics analysis indicate (1) mineral cryosols in the Canadian high Arctic contain atmospheric CH₄-oxidizing bacteria; (2) the atmospheric CH⁺ uptake flux increases with ground temperature; and, as a result, (3) the atmospheric CH₄ sink strength will increase by a factor of 5-30 as the Arctic warms by 5-15 °C over a century. We demonstrated that acidic mineral cryosols have previously unrecognized potential of negative CH₄ feedback.

  12. Evaluating Impacts of CO2 and CH4 Gas Intrusion into an Unconsolidated Aquifer: Fate of As and Cd

    SciTech Connect (OSTI)

    Lawter, Amanda R.; Qafoku, Nikolla; Shao, Hongbo; Bacon, Diana H.; Brown, Christopher F.

    2015-07-10

    Abstract The sequestration of carbon dioxide (CO2) in deep underground reservoirs has been identified as an important strategy to decrease atmospheric CO2 levels and mitigate global warming, but potential risks on overlying aquifers currently lack a complete evaluation. In addition to CO2, other gases such as methane (CH4) may be present in storage reservoirs. This paper explores for the first time the combined effect of leaking CO2 and CH4 gasses on the fate of major, minor and trace elements in an aquifer overlying a potential sequestration site. Emphasis is placed on the fate of arsenic (As) and cadmium (Cd) released from the sediments or present as soluble constituents in the leaking brine. Results from macroscopic batch and column experiments show that the presence of CH4 (at a concentration of 1 % in the mixture CO2/CH4) does not have a significant effect on solution pH or the concentrations of most major elements (such as Ca, Ba, and Mg). However, the concentrations of Mn, Mo, Si and Na are inconsistently affected by the presence of CH4 (i.e., in at least one sediment tested in this study). Cd is not released from the sediments and spiked Cd is mostly removed from the aqueous phase most likely via adsorption. The fate of sediment associated As [mainly sorbed arsenite or As(III) in minerals] and spiked As [i.e., As5+] is complex. Possible mechanisms that control the As behavior in this system are discussed in this paper. Results are significant for CO2 sequestration risk evaluation and site selection and demonstrate the importance of evaluating reservoir brine and gas stream composition during site selection to ensure the safest site is being chosen.

  13. Implications of Representative Concentration Pathway 4.5 Methane Emissions to Stabilize Radiative Forcing

    SciTech Connect (OSTI)

    Emanuel, William R.; Janetos, Anthony C.

    2013-02-01

    Increases in the abundance of methane (CH4) in the Earth’s atmosphere are responsible for significant radiative forcing of climate change (Forster et al., 2007; Wuebbles and Hayhoe, 2002). Since 1750, a 2.5 fold increase in atmospheric CH4 contributed 0.5 W/m2 to direct radiative forcing and an additional 0.2 W/m2 indirectly through changes in atmospheric chemistry. Next to water and carbon dioxide (CO2), methane is the most abundant greenhouse gas in the troposphere. Additionally, CH4 is significantly more effective as a greenhouse gas on a per molecule basis than is CO2, and increasing atmospheric CH4 has been second only to CO2 in radiative forcing (Forster et al., 2007). The chemical reactivity of CH4 is important to both tropospheric and stratospheric chemistry. Along with carbon monoxide, methane helps control the amount of the hydroxyl radical (OH) in the troposphere where oxidation of CH4 by OH leads to the formation of formaldehyde, carbon monoxide, and ozone.

  14. Methanogenic Conversion of CO2 Into CH4

    SciTech Connect (OSTI)

    Stevens, S.H., Ferry, J.G., Schoell, M.

    2012-05-06

    This SBIR project evaluated the potential to remediate geologic CO2 sequestration sites into useful methane gas fields by application of methanogenic bacteria. Such methanogens are present in a wide variety of natural environments, converting CO2 into CH4 under natural conditions. We conclude that the process is generally feasible to apply within many of the proposed CO2 storage reservoir settings. However, extensive further basic R&D still is needed to define the precise species, environments, nutrient growth accelerants, and economics of the methanogenic process. Consequently, the study team does not recommend Phase III commercial application of the technology at this early phase.

  15. ARM - Datastreams - avhrr11ch4

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ch4 Documentation XDC documentation Data Quality Plots ARM Data Discovery Browse Data Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA....

  16. ARM - Datastreams - fullavhrr16ch4

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  17. ARM - Datastreams - avhrr16ch4

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  18. ARM - Datastreams - avhrr17ch4

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  19. ARM - Datastreams - avhrr10ch4

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  20. ARM - Datastreams - fullavhrr12ch4

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  1. ARM - Datastreams - fullavhrr10ch4

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  2. ARM - Datastreams - avhrr14ch4

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  3. ARM - Datastreams - fullavhrr11ch4

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  4. ARM - Datastreams - fullavhrr15ch4

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  5. ARM - Datastreams - avhrr15ch4

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  6. ARM - Datastreams - avhrr12ch4

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  7. ARM - Datastreams - fullavhrr14ch4

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  8. ARM - Datastreams - fullavhrr17ch4

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  9. Quantification of the Potential Gross Economic Impacts of Five Methane Reduction Scenarios

    SciTech Connect (OSTI)

    Keyser, David; Warner, Ethan; Curley, Christina

    2015-04-23

    Methane (CH4) is a potent greenhouse gas that is released from the natural gas supply chain into the atmosphere as a result of fugitive emissions1 and venting2 . We assess five potential CH4 reduction scenarios from transmission, storage, and distribution (TS&D) using published literature on the costs and the estimated quantity of CH4 reduced. We utilize cost and methane inventory data from ICF (2014) and Warner et al. (forthcoming) as well as data from Barrett and McCulloch (2014) and the American Gas Association (AGA) (2013) to estimate that the implementation of these measures could support approximately 85,000 jobs annually from 2015 to 2019 and reduce CH4 emissions from natural gas TS&D by over 40%. Based on standard input/output analysis methodology, measures are estimated to support over $8 billion in GDP annually over the same time period and allow producers to recover approximately $912 million annually in captured gas.

  10. Atmospheric Inverse Estimates of Methane Emissions from Central California

    SciTech Connect (OSTI)

    Zhao, Chuanfeng; Andrews, Arlyn E.; Bianco, Laura; Eluszkiewicz, Janusz; Hirsch, Adam; MacDonald, Clinton; Nehrkorn, Thomas; Fischer, Marc L.

    2008-11-21

    Methane mixing ratios measured at a tall-tower are compared to model predictions to estimate surface emissions of CH{sub 4} in Central California for October-December 2007 using an inverse technique. Predicted CH{sub 4} mixing ratios are calculated based on spatially resolved a priori CH{sub 4} emissions and simulated atmospheric trajectories. The atmospheric trajectories, along with surface footprints, are computed using the Weather Research and Forecast (WRF) coupled to the Stochastic Time-Inverted Lagrangian Transport (STILT) model. An uncertainty analysis is performed to provide quantitative uncertainties in estimated CH{sub 4} emissions. Three inverse model estimates of CH{sub 4} emissions are reported. First, linear regressions of modeled and measured CH{sub 4} mixing ratios obtain slopes of 0.73 {+-} 0.11 and 1.09 {+-} 0.14 using California specific and Edgar 3.2 emission maps respectively, suggesting that actual CH{sub 4} emissions were about 37 {+-} 21% higher than California specific inventory estimates. Second, a Bayesian 'source' analysis suggests that livestock emissions are 63 {+-} 22% higher than the a priori estimates. Third, a Bayesian 'region' analysis is carried out for CH{sub 4} emissions from 13 sub-regions, which shows that inventory CH{sub 4} emissions from the Central Valley are underestimated and uncertainties in CH{sub 4} emissions are reduced for sub-regions near the tower site, yielding best estimates of flux from those regions consistent with 'source' analysis results. The uncertainty reductions for regions near the tower indicate that a regional network of measurements will be necessary to provide accurate estimates of surface CH{sub 4} emissions for multiple regions.

  11. Reviews and syntheses: Four decades of modeling methane cycling in terrestrial ecosystems

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xu, Xiaofeng; Yuan, Fengming; Hanson, Paul J.; Wullschleger, Stan D.; Thornton, Peter E.; Riley, William J.; Song, Xia; Graham, David E.; Song, Changchun; Tian, Hanqin

    2016-06-28

    Over the past 4 decades, a number of numerical models have been developed to quantify the magnitude, investigate the spatial and temporal variations, and understand the underlying mechanisms and environmental controls of methane (CH4) fluxes within terrestrial ecosystems. These CH4 models are also used for integrating multi-scale CH4 data, such as laboratory-based incubation and molecular analysis, field observational experiments, remote sensing, and aircraft-based measurements across a variety of terrestrial ecosystems. Here we summarize 40 terrestrial CH4 models to characterize their strengths and weaknesses and to suggest a roadmap for future model improvement and application. Our key findings are that (1) themore » focus of CH4 models has shifted from theoretical to site- and regional-level applications over the past 4 decades, (2) large discrepancies exist among models in terms of representing CH4 processes and their environmental controls, and (3) significant data–model and model–model mismatches are partially attributed to different representations of landscape characterization and inundation dynamics. Three areas for future improvements and applications of terrestrial CH4 models are that (1) CH4 models should more explicitly represent the mechanisms underlying land–atmosphere CH4 exchange, with an emphasis on improving and validating individual CH4 processes over depth and horizontal space, (2) models should be developed that are capable of simulating CH4 emissions across highly heterogeneous spatial and temporal scales, particularly hot moments and hotspots, and (3) efforts should be invested to develop model benchmarking frameworks that can easily be used for model improvement, evaluation, and integration with data from molecular to global scales. These improvements in CH4 models would be beneficial for the Earth system models and further simulation of climate–carbon cycle feedbacks.« less

  12. Reviews and syntheses: Four decades of modeling methane cycling in terrestrial ecosystems

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xu, Xiaofeng; Yuan, Fengming; Hanson, Paul J.; Wullschleger, Stan D.; Thornton, Peter E.; Riley, William J.; Song, Xia; Graham, David E.; Song, Changchun; Tian, Hanqin

    2016-01-28

    A number of numerical models have been developed to quantify the magnitude, over the past 4 decades, such that we have investigated the spatial and temporal variations, and understand the underlying mechanisms and environmental controls of methane (CH4) fluxes within terrestrial ecosystems. These CH4 models are also used for integrating multi-scale CH4 data, such as laboratory-based incubation and molecular analysis, field observational experiments, remote sensing, and aircraft-based measurements across a variety of terrestrial ecosystems. Here we summarize 40 terrestrial CH4 models to characterize their strengths and weaknesses and to suggest a roadmap for future model improvement and application. Our keymore » findings are that (1) the focus of CH4 models has shifted from theoretical to site- and regional-level applications over the past 4 decades, (2) large discrepancies exist among models in terms of representing CH4 processes and their environmental controls, and (3) significant data–model and model–model mismatches are partially attributed to different representations of landscape characterization and inundation dynamics. Furthermore three areas for future improvements and applications of terrestrial CH4 models are that (1) CH4 models should more explicitly represent the mechanisms underlying land–atmosphere CH4 exchange, with an emphasis on improving and validating individual CH4 processes over depth and horizontal space, (2) models should be developed that are capable of simulating CH4 emissions across highly heterogeneous spatial and temporal scales, particularly hot moments and hotspots, and (3) efforts should be invested to develop model benchmarking frameworks that can easily be used for model improvement, evaluation, and integration with data from molecular to global scales. Finally, these improvements in CH4 models would be beneficial for the Earth system models and further simulation of climate–carbon cycle feedbacks.« less

  13. Top-down methane emissions estimates for the San Francisco Bay Area from 1990 to 2012

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fairley, David; Fischer, Marc L.

    2015-01-30

    Methane is a potent greenhouse gas (GHG) that is now included in both California State and San Francisco Bay Area (SFBA) bottom-up emission inventories as part of California's effort to reduce anthropogenic GHG emissions. Here we provide a top-down estimate of methane (CH4) emissions from the SFBA by combining atmospheric measurements with the comparatively better estimated emission inventory for carbon monoxide (CO). Local enhancements of CH4 and CO are estimated using measurements from 14 air quality sites in the SFBA combined together with global background measurements. Mean annual CH4 emissions are estimated from the product of Bay Area Air Qualitymore » Management District (BAAQMD) emission inventory CO and the slope of ambient local CH4 to CO. The resulting top-down estimates of CH4 emissions are found to decrease slightly from 1990 to 2012, with a mean value of 240 ± 60 GgCH4 yr⁻¹ (at 95% confidence) in the most recent (2009–2012) period, and correspond to reasonably a constant factor of 1.5–2.0 (at 95% confidence) times larger than the BAAQMD CH4 emission inventory. However, we note that uncertainty in these emission estimates is dominated by the variation in CH4:CO enhancement ratios across the observing sites and we expect the estimates could represent a lower-limit on CH4 emissions because BAAQMD monitoring sites focus on urban air quality and may be biased toward CO rather than CH4 sources.« less

  14. An active atmospheric methane sink in high Arctic mineral cryosols...

    Office of Scientific and Technical Information (OSTI)

    conditions coupled with -omics analysis indicate (1) mineral cryosols in the Canadian high Arctic contain atmospheric CH-oxidizing bacteria; (2) the atmospheric CH uptake ...

  15. Large methane emission upon spring thaw from natural wetlands in the northern permafrost region

    SciTech Connect (OSTI)

    Song, Changchun [Chinese Academy of Sciences; Xu, Xiaofeng [ORNL; Sun, Xiaoxin [Chinese Academy of Sciences; Tian, Hanqin [Auburn University, Auburn, Alabama; Sun, Li [Chinese Academy of Sciences; Miao, Yuqing [Chinese Academy of Sciences; Wang, Xianwei [Chinese Academy of Sciences; Guo, Yuedong [Chinese Academy of Sciences

    2012-01-01

    The permafrost carbon climate feedback is one of the major mechanisms in controlling the climate ecosystem interactions in northern high latitudes. Of this feedback, methane (CH4) emission from natural wetlands is critically important due to its high warming potential. The freeze thaw transition has been confirmed to play an important role in annual CH4 budget, yet the magnitude of this effect is uncertain. An intensive field campaign was carried out in the Sanjiang Plain, Northeast China to estimate the CH4 emission in the spring freeze thaw transition period. The observation concluded that a large CH4 source was caused by spring thaw; the maximum hourly emission rate was 48.6 g C m 2 h 1, more than three orders of the regularly observed CH4 emission rate in the growing season. In some sporadically observed 'hot spots', the spring thawing effect contributed to a large CH4 source of 31.3 10.1 g C m 2, which is approximately 80% of the previously calculated annual CH4 emission in the same study area. If our results are typical for natural wetlands in the Northern Hemisphere permafrost region, we estimate a global CH4 source strength of 0.5 1.0 Tg C (1 Tg =1012 g) caused by spring thaw in the Northern Hemisphere permafrost region in the year 2011. Combining with available satellite and flask data, a regional extrapolation reaches a temporal pattern of CH4 emission during 2003 2009 which is consistent with recently observed changes in atmospheric CH4 concentration in the high latitudes. This suggests that the CH4 emission upon spring thaw in the high latitudes might be enhanced by the projected climate warming. These findings indicate that the spring thawing effect is an important mechanism in the permafrost carbon climate feedback and needs to be incorporated in Earth system models.

  16. Fluxes of methane between landfills and the atmosphere: Natural and engineered controls

    SciTech Connect (OSTI)

    Bogner, J.; Meadows, M.; Czepiel, P.

    1997-08-01

    Field measurement of landfill methane emissions indicates natural variability spanning more than 2 seven orders of magnitude, from approximately 0.0004 to more than 4000 g m{sub -2} day{sup -1}. This wide range reflects net emissions resulting from production (methanogenesis), consumption (methanotrophic oxidation), and gaseous transport processes. The determination of an {open_quotes}average{close_quotes} emission rate for a given field site requires sampling designs and statistical techniques which consider spatial and temporal variability. Moreover, particularly at sites with pumped gas recovery systems, it is possible for methanotrophic microorganisms in aerated cover soils to oxidize all of the methane from landfill sources below and, additionally, to oxidize methane diffusing into cover soils from atmospheric sources above. In such cases, a reversed soil gas concentration gradient is observed in shallow cover soils, indicating bidirectional diffusional transport to the depth of optimum methane oxidation. Rates of landfill methane oxidation from field and laboratory incubation studies range up to 166 g m{sup -2} day{sup -1} among the highest for any natural setting, providing an effective natural control on net emissions. Estimates of worldwide landfill methane emissions to the atmosphere have ranged from 9 to 70 Tg yr{sup -1}, differing mainly in assumed methane yields from estimated quantities of landfilled refuse. At highly controlled landfill sites in developed countries, landfill methane is often collected via vertical wells or horizontal collectors. Recovery of landfill methane through engineered systems can provide both environmental and energy benefits by mitigating subsurface migration, reducing surface emissions, and providing an alternative energy resource for industrial boiler use, on-site electrical generation, or upgrading to a substitute natural gas.

  17. Insights into the structure of mixed CO2/CH4 in gas hydrates

    SciTech Connect (OSTI)

    Everett, Susan M; Rawn, Claudia J; Chakoumakos, Bryan C; Keffer, David J.; Huq, Ashfia; Phelps, Tommy Joe

    2015-01-01

    The exchange of CO2 for CH4 in natural gas hydrates is an attractive approach to methane for energy production while simultaneously sequestering CO2. In addition to the energy and environmental implications, the solid solution of clathrate hydrate (CH4)1-x(CO2)x 5.75H2O provides a model system to study how the distinct bonding and shapes of CH4 and CO2 influence the structure and properties of the compound. High-resolution neutron diffraction was used to examine mixed CO2/CH4 gas hydrates. CO2-rich hydrates had smaller lattice parameters, which were attributed to the higher affinity of the CO2 molecule interacting with H2O molecules that form the surrounding cages, and resulted in a reduction in the unit cell volume. Experimental nuclear scattering densities illustrate how the cage occupants and energy landscape change with composition. These results provide important insights on the impact and mechanisms for exchanging CH4 and CO2.

  18. Insights into the structure of mixed CO2/CH4 in gas hydrates

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Everett, S. Michelle; Rawn, Claudia J.; Chakoumakos, Bryan C.; Keffer, David J.; Huq, Ashfia; Phelps, Tommy J.

    2015-05-12

    The exchange of carbon dioxide for methane in natural gas hydrates is an attractive approach to harvesting CH4 for energy production while simultaneously sequestering CO2. In addition to the energy and environmental implications, the solid solution of clathrate hydrate (CH4)1-x(CO2)x·5.75H2O provides a model system to study how the distinct bonding and shapes of CH4 and CO2 influence the structure and properties of the compound. In this paper, high-resolution neutron diffraction was used to examine mixed CO2/CH4 gas hydrates. CO2-rich hydrates had smaller lattice parameters, which were attributed to the higher affinity of the CO2 molecule interacting with H2O molecules thatmore » form the surrounding cages, and resulted in a reduction in the unit-cell volume. Experimental nuclear scattering densities illustrate how the cage occupants and energy landscape change with composition. Finally, these results provide important insights on the impact and mechanisms for the structure of mixed CH4/CO2 gas hydrate.« less

  19. U.S. Natural Gas System Methane Emissions: State of Knowledge from LCAs, Inventories, and Atmospheric Measurements (Presentation)

    SciTech Connect (OSTI)

    Heath, G.

    2014-04-01

    Natural gas (NG) is a potential "bridge fuel" during transition to a decarbonized energy system: It emits less carbon dioxide during combustion than other fossil fuels and can be used in many industries. However, because of the high global warming potential of methane (CH4, the major component of NG), climate benefits from NG use depend on system leakage rates. Some recent estimates of leakage have challenged the benefits of switching from coal to NG, a large near-term greenhouse gas (GHG) reduction opportunity. During this presentation, Garvin will review evidence from multiple perspectives - life cycle assessments (LCAs), inventories and measurements - about NG leakage in the US. Particular attention will be paid to a recent article in Science magazine which reviewed over 20 years of published measurements to better understand what we know about total methane emissions and those from the oil and gas sectors. Scientific and policy implications of the state of knowledge will be discussed.

  20. DIRECT IMAGING DETECTION OF METHANE IN THE ATMOSPHERE OF GJ 504 b

    SciTech Connect (OSTI)

    Janson, Markus; Brandt, Timothy D.; Kuzuhara, Masayuki; Spiegel, David S.; Thalmann, Christian; Currie, Thayne; Bonnefoy, Mickal; Zimmerman, Neil; Schlieder, Joshua; Brandner, Wolfgang; Feldt, Markus; Sorahana, Satoko; Kotani, Takayuki; Hashimoto, Jun; Kusakabe, Nobuhiko; Kudo, Tomoyuki; Egner, Sebastian; Abe, Lyu; Carson, Joseph C.; Goto, Miwa; and others

    2013-11-20

    Most exoplanets detected by direct imaging thus far have been characterized by relatively hot (?1000K) and cloudy atmospheres. A surprising feature in some of their atmospheres has been a distinct lack of methane, possibly implying non-equilibrium chemistry. Recently, we reported the discovery of a planetary companion to the Sun-like star GJ 504 using Subaru/HiCIAO within the Strategic Exploration of Exoplanets and Disks with Subaru survey. The planet is substantially colder (<600K) than previously imaged planets, and has indications of fewer clouds, which implies that it represents a new class of planetary atmospheres with expected similarities to late T-type brown dwarfs in the same temperature range. If so, one might also expect the presence of significant methane absorption, which is characteristic of such objects. Here, we report the detection of deep methane absorption in the atmosphere of GJ 504 b, using the Spectral Differential Imaging mode of HiCIAO to distinguish the absorption features around 1.6 ?m. We also report updated JHK photometry based on new K {sub s}-band data and a re-analysis of the existing data. The results support the notion that GJ 504 b has atmospheric properties distinct from other imaged exoplanets, and will become a useful reference object for future planets in the same temperature range.

  1. Top-down estimate of methane emissions in California using a mesoscale inverse modeling technique: The South Coast Air Basin

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Cui, Yu Yan; Brioude, Jerome; McKeen, Stuart A.; Angevine, Wayne M.; Kim, Si -Wan; Frost, Gregory J.; Ahmadov, Ravan; Peischl, Jeff; Bousserez, Nicolas; Liu, Zhen; et al

    2015-07-28

    Methane (CH4) is the primary component of natural gas and has a larger global warming potential than CO2. Some recent top-down studies based on observations showed CH4 emissions in California's South Coast Air Basin (SoCAB) were greater than those expected from population-apportioned bottom-up state inventories. In this study, we quantify CH4 emissions with an advanced mesoscale inverse modeling system at a resolution of 8 km × 8 km, using aircraft measurements in the SoCAB during the 2010 Nexus of Air Quality and Climate Change campaign to constrain the inversion. To simulate atmospheric transport, we use the FLEXible PARTicle-Weather Research andmore » Forecasting (FLEXPART-WRF) Lagrangian particle dispersion model driven by three configurations of the Weather Research and Forecasting (WRF) mesoscale model. We determine surface fluxes of CH4 using a Bayesian least squares method in a four-dimensional inversion. Simulated CH4 concentrations with the posterior emission inventory achieve much better correlations with the measurements (R2 = 0.7) than using the prior inventory (U.S. Environmental Protection Agency's National Emission Inventory 2005, R2 = 0.5). The emission estimates for CH4 in the posterior, 46.3 ± 9.2 Mg CH4/h, are consistent with published observation-based estimates. Changes in the spatial distribution of CH4 emissions in the SoCAB between the prior and posterior inventories are discussed. Missing or underestimated emissions from dairies, the oil/gas system, and landfills in the SoCAB seem to explain the differences between the prior and posterior inventories. Furthermore, we estimate that dairies contributed 5.9 ± 1.7 Mg CH4/h and the two sectors of oil and gas industries (production and downstream) and landfills together contributed 39.6 ± 8.1 Mg CH4/h in the SoCAB.« less

  2. CO2 CH4 flux Air temperature Soil temperature and Soil moisture, Barrow, Alaska 2013 ver. 1

    SciTech Connect (OSTI)

    Margaret Torn

    2015-01-14

    This dataset consists of field measurements of CO2 and CH4 flux, as well as soil properties made during 2013 in Areas A-D of Intensive Site 1 at the Next-Generation Ecosystem Experiments (NGEE) Arctic site near Barrow, Alaska. Included are i) measurements of CO2 and CH4 flux made from June to September (ii) Calculation of corresponding Gross Primary Productivity (GPP) and CH4 exchange (transparent minus opaque) between atmosphere and the ecosystem (ii) Measurements of Los Gatos Research (LGR) chamber air temperature made from June to September (ii) measurements of surface layer depth, type of surface layer, soil temperature and soil moisture from June to September.

  3. CO2 CH4 flux Air temperature Soil temperature and Soil moisture, Barrow, Alaska 2013 ver. 1

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Margaret Torn

    This dataset consists of field measurements of CO2 and CH4 flux, as well as soil properties made during 2013 in Areas A-D of Intensive Site 1 at the Next-Generation Ecosystem Experiments (NGEE) Arctic site near Barrow, Alaska. Included are i) measurements of CO2 and CH4 flux made from June to September (ii) Calculation of corresponding Gross Primary Productivity (GPP) and CH4 exchange (transparent minus opaque) between atmosphere and the ecosystem (ii) Measurements of Los Gatos Research (LGR) chamber air temperature made from June to September (ii) measurements of surface layer depth, type of surface layer, soil temperature and soil moisture from June to September.

  4. New materials for methane capture from dilute and medium-concentration sources

    SciTech Connect (OSTI)

    Kim, J; Maiti, A; Lin, LC; Stolaroff, JK; Smit, B; Aines, RD

    2013-04-16

    Methane (CH4) is an important greenhouse gas, second only to CO2, and is emitted into the atmosphere at different concentrations from a variety of sources. However, unlike CO2, which has a quadrupole moment and can be captured both physically and chemically in a variety of solvents and porous solids, methane is completely non-polar and interacts very weakly with most materials. Thus, methane capture poses a challenge that can only be addressed through extensive material screening and ingenious molecular-level designs. Here we report systematic in silico studies on the methane capture effectiveness of two different materials systems, that is, liquid solvents (including ionic liquids) and nanoporous zeolites. Although none of the liquid solvents appears effective as methane sorbents, systematic screening of over 87,000 zeolite structures led to the discovery of a handful of candidates that have sufficient methane sorption capacity as well as appropriate CH4/CO2 and/or CH4/N-2 selectivity to be technologically promising.

  5. Methane and carbon dioxide emissions from 40 lakes along a north–south latitudinal transect in Alaska

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sepulveda-Jauregui, A.; Walter Anthony, K. M.; Martinez-Cruz, K.; Greene, S.; Thalasso, F.

    2014-09-12

    Uncertainties in the magnitude and seasonality of various gas emission modes, particularly among different lake types, limit our ability to estimate methane (CH4) and carbon dioxide (CO2) emissions from northern lakes. Here we assessed the relationship between CH4 and CO2 emission modes in 40 lakes along a latitudinal transect in Alaska to physicochemical limnology and geographic characteristics, including permafrost soil type surrounding lakes. Emission modes included Direct Ebullition, Diffusion, Storage flux, and a newly identified Ice-Bubble Storage (IBS) flux. We found that all lakes were net sources of atmospheric CH4 and CO2, but the climate warming impact of lake CH4more » emissions was two times higher than that of CO2. Ebullition and Diffusion were the dominant modes of CH4 and CO2 emissions respectively. IBS, ~ 10% of total annual CH4 emissions, is the release to the atmosphere of seasonally ice-trapped bubbles when lake ice confining bubbles begins to melt in spring. IBS, which has not been explicitly accounted for in regional studies, increased the estimate of springtime emissions from our study lakes by 320%. Geographically, CH4 emissions from stratified, dystrophic interior Alaska thermokarst (thaw) lakes formed in icy, organic-rich yedoma permafrost soils were 6-fold higher than from non-yedoma lakes throughout the rest of Alaska. Total CH4 emission was correlated with concentrations of phosphate and total nitrogen in lake water, Secchi depth and lake area, with yedoma lakes having higher nutrient concentrations, shallower Secchi depth, and smaller lake areas. Our findings suggest that permafrost type plays important roles in determining CH4 emissions from lakes by both supplying organic matter to methanogenesis directly from thawing permafrost and by enhancing nutrient availability to primary production, which can also fuel decomposition and methanogenesis.« less

  6. Analyzing source apportioned methane in northern California during Discover-AQ-CA using airborne measurements and model simulations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Johnson, Matthew S.; Yates, Emma L.; Iraci, Laura T.; Loewenstein, Max; Tadić, Jovan M.; Wecht, Kevin J.; Jeong, Seongeun; Fischer, Marc L.

    2014-12-01

    This study analyzes source apportioned methane (CH4) emissions and atmospheric mixing ratios in northern California during the Discover-AQ-CA field campaign using airborne measurement data and model simulations. Source apportioned CH4 emissions from the Emissions Database for Global Atmospheric Research (EDGAR) version 4.2 were applied in the 3-D chemical transport model GEOS-Chem and analyzed using airborne measurements taken as part of the Alpha Jet Atmospheric eXperiment over the San Francisco Bay Area (SFBA) and northern San Joaquin Valley (SJV). During the time period of the Discover-AQ-CA field campaign EDGAR inventory CH4 emissions were ~5.30 Gg day –1 (Gg = 1.0 ×more » 109 g) (equating to ~1.90 × 103 Gg yr–1) for all of California. According to EDGAR, the SFBA and northern SJV region contributes ~30% of total CH4 emissions from California. Source apportionment analysis during this study shows that CH4 mixing ratios over this area of northern California are largely influenced by global emissions from wetlands and local/global emissions from gas and oil production and distribution, waste treatment processes, and livestock management. Model simulations, using EDGAR emissions, suggest that the model under-estimates CH4 mixing ratios in northern California (average normalized mean bias (NMB) = –5.2% and linear regression slope = 0.20). The largest negative biases in the model were calculated on days when large amounts of CH4 were measured over local emission sources and atmospheric CH4 mixing ratios reached values >2.5 parts per million. Sensitivity emission studies conducted during this research suggest that local emissions of CH4 from livestock management processes are likely the primary source of the negative model bias. These results indicate that a variety, and larger quantity, of measurement data needs to be obtained and additional research is necessary to better quantify source apportioned CH4 emissions in California.« less

  7. METHANE IN THE ATMOSPHERE OF THE TRANSITING HOT NEPTUNE GJ436B?

    SciTech Connect (OSTI)

    Beaulieu, J.-P.; Batista, V.; Tinetti, G.; Kipping, D. M.; Barber, R. J.; Tennyson, J.; Waldmann, I.; Miller, S.; Fossey, S. J.; Aylward, A.; Ribas, I.; Cho, J. Y.-K.; Polichtchouk, I.; Yurchenko, S. N.; Griffith, C. A.; Carey, S.; Mousis, O.

    2011-04-10

    We present an analysis of seven primary transit observations of the hot Neptune GJ436b at 3.6, 4.5, and 8 {mu}m obtained with the Infrared Array Camera on the Spitzer Space Telescope. After correcting for systematic effects, we fitted the light curves using the Markov Chain Monte Carlo technique. Combining these new data with the EPOXI, Hubble Space Telescope, and ground-based V, I, H, and K{sub s} published observations, the range 0.5-10 {mu}m can be covered. Due to the low level of activity of GJ436, the effect of starspots on the combination of transits at different epochs is negligible at the accuracy of the data set. Representative climate models were calculated by using a three-dimensional, pseudospectral general circulation model with idealized thermal forcing. Simulated transit spectra of GJ436b were generated using line-by-line radiative transfer models including the opacities of the molecular species expected to be present in such a planetary atmosphere. A new, ab-initio-calculated, line list for hot ammonia has been used for the first time. The photometric data observed at multiple wavelengths can be interpreted with methane being the dominant absorption after molecular hydrogen, possibly with minor contributions from ammonia, water, and other molecules. No clear evidence of carbon monoxide and carbon dioxide is found from transit photometry. We discuss this result in the light of a recent paper where photochemical disequilibrium is hypothesized to interpret secondary transit photometric data. We show that the emission photometric data are not incompatible with the presence of abundant methane, but further spectroscopic data are desirable to confirm this scenario.

  8. CO2 and CH4 Fluxes across Polygon Geomorphic Types, Barrow, Alaska, 2006-2010

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Tweedie,Craig; Lara, Mark

    2014-09-17

    Carbon flux data are reported as Net Ecosystem Exchange (NEE), Gross Ecosystem Exchange (GEE), Ecosystem Respiration (ER), and Methane (CH4) flux. Measurements were made at 82 plots across various polygon geomorphic classes at research sites on the Barrow Environmental Observatory (BEO), the Biocomplexity Experiment site on the BEO, and the International Biological Program (IBP) site a little west of the BEO. This product is a compilation of data from 27 plots as presented in Lara et al. (2012), data from six plots presented in Olivas et al. (2010); and from 49 plots described in (Lara et al. 2014). Measurements were made during the peak of the growing seasons during 2006 to 2010. At each of the measurement plots (except Olivas et al., 2010) four different thicknesses of shade cloth were used to generate CO2 light response curves. Light response curves were used to normalize photosynthetically active radiation that is diurnally variable to a peak growing season average ~400 umolm-2sec-1. At the Olivas et al. (2010) plots, diurnal patterns were characterized by repeated sampling. CO2 measurements were made using a closed-chamber photosynthesis system and CH4 measurements were made using a photo-acoustic multi-gas analyzer. In addition, plot-level measurements for thaw depth (TD), water table depth (WTD), leaf area index (LAI), and normalized difference vegetation index (NDVI) are summarized by geomorphic polygon type.

  9. CO2 and CH4 Fluxes across Polygon Geomorphic Types, Barrow, Alaska, 2006-2010

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Tweedie,Craig; Lara, Mark

    Carbon flux data are reported as Net Ecosystem Exchange (NEE), Gross Ecosystem Exchange (GEE), Ecosystem Respiration (ER), and Methane (CH4) flux. Measurements were made at 82 plots across various polygon geomorphic classes at research sites on the Barrow Environmental Observatory (BEO), the Biocomplexity Experiment site on the BEO, and the International Biological Program (IBP) site a little west of the BEO. This product is a compilation of data from 27 plots as presented in Lara et al. (2012), data from six plots presented in Olivas et al. (2010); and from 49 plots described in (Lara et al. 2014). Measurements were made during the peak of the growing seasons during 2006 to 2010. At each of the measurement plots (except Olivas et al., 2010) four different thicknesses of shade cloth were used to generate CO2 light response curves. Light response curves were used to normalize photosynthetically active radiation that is diurnally variable to a peak growing season average ~400 umolm-2sec-1. At the Olivas et al. (2010) plots, diurnal patterns were characterized by repeated sampling. CO2 measurements were made using a closed-chamber photosynthesis system and CH4 measurements were made using a photo-acoustic multi-gas analyzer. In addition, plot-level measurements for thaw depth (TD), water table depth (WTD), leaf area index (LAI), and normalized difference vegetation index (NDVI) are summarized by geomorphic polygon type.

  10. Multi-scale Atmospheric Modeling of Green House Gas Dispersion in Complex Terrain. Atmospheric Methane at Four Corners

    SciTech Connect (OSTI)

    Costigan, Keeley Rochelle; Dubey, Manvendra Krishna

    2015-07-10

    Atmospheric models are compared in collaboration with LANL and the University of Michigan to understand emissions and the condition of the atmosphere from a model perspective.

  11. Methane and carbon dioxide emissions from 40 lakes along a north–south latitudinal transect in Alaska

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sepulveda-Jauregui, A.; Walter Anthony, K. M.; Martinez-Cruz, K.; Greene, S.; Thalasso, F.

    2015-06-02

    Uncertainties in the magnitude and seasonality of various gas emission modes, particularly among different lake types, limit our ability to estimate methane (CH4) and carbon dioxide (CO2) emissions from northern lakes. Here we assessed the relationship between CH4 and CO2 emission modes in 40 lakes along a latitudinal transect in Alaska to lakes' physicochemical properties and geographic characteristics, including permafrost soil type surrounding lakes. Emission modes included direct ebullition, diffusion, storage flux, and a newly identified ice-bubble storage (IBS) flux. We found that all lakes were net sources of atmospheric CH4 and CO2, but the climate warming impact of lakemore » CH4 emissions was 2 times higher than that of CO2. Ebullition and diffusion were the dominant modes of CH4 and CO2 emissions, respectively. IBS, ~10% of total annual CH4 emissions, is the release to the atmosphere of seasonally ice-trapped bubbles when lake ice confining bubbles begins to melt in spring. IBS, which has not been explicitly accounted for in regional studies, increased the estimate of springtime emissions from our study lakes by 320%. Geographically, CH4 emissions from stratified, mixotrophic interior Alaska thermokarst (thaw) lakes formed in icy, organic-rich yedoma permafrost soils were 6-fold higher than from non-yedoma lakes throughout the rest of Alaska. The relationship between CO2 emissions and geographic parameters was weak, suggesting high variability among sources and sinks that regulate CO2 emissions (e.g., catchment waters, pH equilibrium). Total CH4 emission was correlated with concentrations of soluble reactive phosphorus and total nitrogen in lake water, Secchi depth, and lake area, with yedoma lakes having higher nutrient concentrations, shallower Secchi depth, and smaller lake areas. Our findings suggest that permafrost type plays important roles in determining CH4 emissions from lakes by both supplying organic matter to methanogenesis directly from

  12. Mapping pan-Arctic methane emissions at high spatial resolution using an adjoint atmospheric transport and inversion method and process-based wetland and lake biogeochemical models

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tan, Z.; Zhuang, Q.; Henze, D. K.; Frankenberg, C.; Dlugokencky, E.; Sweeney, C.; Turner, A. J.

    2015-11-18

    Understanding methane emissions from the Arctic, a fast warming carbon reservoir, is important for projecting changes in the global methane cycle under future climate scenarios. Here we optimize Arctic methane emissions with a nested-grid high-resolution inverse model by assimilating both high-precision surface measurements and column-average SCIAMACHY satellite retrievals of methane mole fraction. For the first time, methane emissions from lakes are integrated into an atmospheric transport and inversion estimate, together with prior wetland emissions estimated by six different biogeochemical models. We find that, the global methane emissions during July 2004June 2005 ranged from 496.4 to 511.5 Tg yr?1, with wetlandmoremethane emissions ranging from 130.0 to 203.3 Tg yr?1. The Arctic methane emissions during July 2004June 2005 were in the range of 14.630.4 Tg yr?1, with wetland and lake emissions ranging from 8.8 to 20.4 Tg yr?1 and from 5.4 to 7.9 Tg yr?1 respectively. Canadian and Siberian lakes contributed most of the estimated lake emissions. Due to insufficient measurements in the region, Arctic methane emissions are less constrained in northern Russia than in Alaska, northern Canada and Scandinavia. Comparison of different inversions indicates that the distribution of global and Arctic methane emissions is sensitive to prior wetland emissions. Evaluation with independent datasets shows that the global and Arctic inversions improve estimates of methane mixing ratios in boundary layer and free troposphere. The high-resolution inversions provide more details about the spatial distribution of methane emissions in the Arctic.less

  13. SAPO-34 Membranes for N-2/CH4 separation: Preparation, characterization, separation performance and economic evaluation

    SciTech Connect (OSTI)

    Li, SG; Zong, ZW; Zhou, SJ; Huang, Y; Song, ZN; Feng, XH; Zhou, RF; Meyer, HS; Yu, M; Carreon, MA

    2015-08-01

    SAPO-34 membranes were synthesized by several routes towards N-2/CH4 separation. Membrane synthesis parameters including water content in the gel, crystallization time, support pore size, and aluminum source were investigated. High performance N-2-selective membranes were obtained on 100-nm-pore alumina tubes by using Al(i-C3H7O)(3) as aluminum source with a crystallization time of 6 h. These membranes separated N-2 from CH, with N-2 permeance as high as 500 GPU with separation selectivity of 8 at 24 degrees C. for a 50/50 N-2/CH4 mixture. Nitrogen and CH, adsorption isotherms were measured on SAPO-34 crystals. The N-2 and CH, heats of adsorption were 11 and 15 kJ/mol, respectively, which lead to a preferential adsorption of CE-H-4 over N-2 in the N-2/CH4 mixture. Despite this, the SAPO-34 membranes were selective for N-2 over CH4 in the mixture because N-2 diffuses much faster than CH4 and differences in diffusivity played a more critical role than the competitive adsorption. Preliminary economic evaluation indicates that the required N-2/CH4 selectivity would be 15 in order to maintain a CH4 loss below 10%. For small nitrogen-contaminated gas wells, our current SAPO-34 membranes have potential to compete with the benchmark technology cryogenic distillation for N-2 rejection. (C) 2015 Elsevier B.V. All rights reserved,

  14. Project identification for methane reduction options

    SciTech Connect (OSTI)

    Kerr, T.

    1996-12-31

    This paper discusses efforts directed at reduction in emission of methane to the atmosphere. Methane is a potent greenhouse gas, which on a 20 year timeframe may present a similar problem to carbon dioxide. In addition, methane causes additional problems in the form of smog and its longer atmospheric lifetime. The author discusses strategies for reducing methane emission from several major sources. This includes landfill methane recovery, coalbed methane recovery, livestock methane reduction - in the form of ruminant methane reduction and manure methane recovery. The author presents examples of projects which have implemented these ideas, the economics of the projects, and additional gains which come from the projects.

  15. Hindering effects in diffusion of CO2/CH4 mixtures in ZIF-8 crystals...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hindering effects in diffusion of CO2CH4 mixtures in ZIF-8 crystals Previous Next List C. Chmelik, J. van Baten, and R. Krishna, J. Membr. Sci. 397, 87 (2012) DOI: 10.1016...

  16. Molecular Simulation Studies of Separation of CO2/N2, CO2/CH4...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    do this, we first identified a suitable force field for describing CO2, N2, and CH4 adsorption in ZIFs. On the basis of the validated force field, adsorption selectivities of the...

  17. Carbon-13 isotopic abundance and concentration of atmospheric methane for background air in the Southern and Northern Hemispheres from 1978 to 1989

    SciTech Connect (OSTI)

    Stevens, C.M.; Sepanski; Morris, L.J.

    1995-03-01

    Atmospheric methane (CH{sub 4}) may become an increasingly important contributor to global warming in future years. Its atmospheric concentration has risen, doubling over the past several hundred years, and additional methane is thought to have a much greater effect on climate, on a per molecule basis, than additional C0{sub 2} at present day concentrations (Shine et al. 1990). The causes of the increase of atmospheric CH{sub 4} have been difficult to ascertain because of a lack of quantitative knowledge of the fluxes (i.e., net emissions) from the numerous anthropogenic and natural sources. The goal of CH{sub 4} isotopic studies is to provide a constraint (and so reduce the uncertainties) in estimating the relative fluxes from the various isotopically distinct sources, whose combined fluxes must result in the measured atmospheric isotopic composition, after the fractionating effect of the atmospheric removal process is considered. In addition, knowledge of the spatial and temporal changes in the isotopic composition of atmospheric CH{sub 4}, along with estimates of the fluxes from some of the major sources, makes it possible to calculate growth rates for sources whose temporal emissions trends would be difficult to measure directly.

  18. CW EC-QCL-based sensor for simultaneous detection of H2O, HDO, N2O and CH4 using multi-pass absorption spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yu, Yajun; Sanchez, Nancy P.; Griffin, Robert J.; Tittel, Frank K.

    2016-05-03

    A sensor system based on a continuous wave, external-cavity quantum-cascade laser (CW EC-QCL) was demonstrated for simultaneous detection of atmospheric H2O, HDO, N2O and CH4 using a compact, dense pattern multi-pass gas cell with an effective path-length of 57.6 m. The EC-QCL with a mode-hop-free spectral range of 1225-1285 cm-1 operating at similar to 7.8 mu m was scanned covering four neighboring absorption lines, for H2O at 1281.161 cm-1, HDO at 1281.455 cm-1, N2O at 1281.53 cm-1 and CH4 at 1281.61 cm-1. A first-harmonic-normalized wavelength modulation spectroscopy with second-harmonic detection (WMS-2f/1f) strategy was employed for data processing. An Allan-Werle deviationmore » analysis indicated that minimum detection limits of 1.77 ppmv for H2O, 3.92 ppbv for HDO, 1.43 ppbv for N2O, and 2.2 ppbv for CH4 were achieved with integration times of 50-s, 50-s, 100-s and 129-s, respectively. In conclusion, experimental measurements of ambient air are also reported.« less

  19. ch_4

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    0 4.0 Aff Aff ected ected E E nvir nvir onment onment 4-1 DOE/EIS-0287 4.1 Introduction This chapter describes the environment of the Idaho National Engineering and Environmental Laboratory (INEEL) and surrounding area that could be affected by the alternatives analyzed in this environ- mental impact statement (EIS). One of the alternatives under consideration, the Minimum INEEL Processing Alternative, would involve treatment of INEEL high- level waste (HLW) at the Hanford Site. Appendix C.8

  20. ch_4

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    1998, INEEL contracts paid $1.4 million to the State of Idaho in Idaho sales taxes and an additional $0.9 million in Idaho franchise tax. 4.4 Cultural Resources 4.4.1 CULTURAL RESOURCE MANAGEMENT AND CONSULTATION AT INEEL Cultural resources at INEEL include archaeolog- ical and historic resources, such as prehistoric camp sites and historic buildings and trails, as well as the plants, animals, physical locations, and other features of INEEL environment impor- tant to the culture of the

  1. ch_4

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    18 Affected Environment visual range of the Fort Hall Indian Reservation. The Bitterroot, Lemhi, and Lost River mountain ranges are visible to the north and west of INEEL. East Butte and Middle Butte can be seen near the southern boundary, while Circular and Antelope Buttes are visible to the northeast. Smaller volcanic buttes dot the natural landscape of INEEL, providing a striking contrast to the relatively flat ground surface. The viewscape in general consists of terrain dominated by sage-

  2. ch_4

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    40 Affected Environment playas 15 to 20 miles northeast of INTEC, where the water infiltrates. The water in Birch Creek and the Little Lost River is diverted in summer months for irriga- tion prior to reaching INEEL. During periods of unusually high precipitation or rapid snow melt, water from Birch Creek and the Little Lost River may enter INEEL from the northwest and infil- trate the ground, recharging the underlying aquifer. 4.8.1.2 Local Drainage INTEC is located on an alluvial plain

  3. ch_4

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    58 Affected Environment 4.9.1 PLANT COMMUNITIES AND ASSOCIATIONS INEEL lies within a cool desert ecosystem dom- inated by shrub-steppe vegetation. The area is relatively undisturbed, providing important habi- tat for species native to the region. Vegetation and habitat on INEEL can be grouped into six types: shrub-steppe, juniper woodlands, native grasslands, modified ephemeral playas, lava, and wetland-like areas. Figure 4-16 shows these areas. More than 90 percent of INEEL falls within the

  4. ch_4

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... Low-income populations are identified using statistical poverty thresholds from the Bureau of Census Current Population Reports, Series P-60 on Income and Poverty. In identifying ...

  5. ch_4

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    47 DOEEIS-0287 Idaho HLW & FD EIS 4.8.2 SUBSURFACE WATER Subsurface water at INEEL occurs in the under- lying Snake River Plain Aquifer and the vadose zone (area of unsaturated ...

  6. ch_4

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... Air quality regulations have been established to protect the public from potential harmful effects of air pollution. These regulations (a) designate acceptable levels of pollution ...

  7. Four Corners methane hotspot points to coal-related sources

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Methane hotspot points to coal-related sources Four Corners methane hotspot points to coal-related sources Methane is very efficient at trapping heat in the atmosphere and, like ...

  8. JISEA News: Study on Methane Emissions from Natural Gas Systems Indicates

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    New Priorities - News Releases | NREL JISEA News: Study on Methane Emissions from Natural Gas Systems Indicates New Priorities Study findings published in Policy Forum of Journal Science February 18, 2014 A new study published in the journal Science says that the total impact of switching to natural gas depends heavily on leakage of methane (CH4) during the natural gas life cycle, and suggests that more can be done to reduce methane emissions and to improve measurement tools which help

  9. Mode-selective chemistry on metal surfaces: The dissociative chemisorption of CH4 on Pt(111)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Guo, Han; Jackson, Bret

    2016-05-13

    A quantum approach based on an expansion in vibrationally adiabatic eigenstates is used to explore CH4 dissociation on Pt(111). Computed sticking probabilities for molecules in the ground, 1v3 and 2v3, states are in very good agreement with the available experimental data, reproducing the variation in reactivity with collision energy and vibrational state. As was found in similar studies on Ni(100) and Ni(111), exciting the 1v1 symmetric stretch of CH4 is more effective at promoting the dissociative chemisorption of CH4 than exciting the 1v3 antisymmetric stretch. This behavior is explained in terms of symmetry, mode-softening, and nonadiabatic transitions between vibrationally adiabaticmore » states. We find that the efficacies of the bending modes for promoting reaction are reasonably large, and similar to the 1v3 state. The vibrational efficacies for promoting reaction on Ni(111) are larger than for reaction on Pt(111), due to the larger nonadiabatic couplings. As a result, our computed sticking probabilities are in good agreement with results from recent ab initio molecular dynamics and reactive force field studies.« less

  10. Methane Hydrates and Climate Change | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Hydrates and Climate Change Methane Hydrates and Climate Change Methane hydrates store huge volumes of methane formed by the bacterial decay of organic matter or leaked from underlying oil and natural gas deposits. The active formation of methane hydrates in the shallow crust prevents methane, a greenhouse gas, from entering the atmosphere. On the other hand, warming of arctic sediments or ocean waters has the potential to cause methane hydrate to dissociate, releasing methane into the deepwater

  11. Science on the Hill: Methane cloud hunting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Methane cloud hunting Methane cloud hunting Los Alamos researchers go hunting for methane gas over the Four Corners area of northwest New Mexico and find a strange daily pattern. July 12, 2015 methane map Methane, the primary component of natural gas, is also a potent greenhouse gas, trapping energy in the atmosphere. Last year NASA released satellite images showing a hot spot in the area where New Mexico, Colorado, Utah and Arizona meet, prompting scientists to go in search of the sources.

  12. ARM - Measurement - Methane concentration

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    concentration ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Methane concentration The amount of methane, a greenhouse gas, per unit of volume. Categories Atmospheric Carbon Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those

  13. ARM - Measurement - Methane flux

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    flux ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Methane flux Vertical flux of methane near the surface due to turbulent transport. Categories Surface Properties, Atmospheric Carbon Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including

  14. The future of methane

    SciTech Connect (OSTI)

    Howell, D.G.

    1995-12-31

    Natural gas, mainly methane, produces lower CO{sub 2}, CO, NO{sub x}, SO{sub 2} and particulate emissions than either oil or coal; thus further substitutions of methane for these fuels could help mitigate air pollution. Methane is, however, a potent greenhouse gas and the domestication of ruminants, cultivation of rice, mining of coal, drilling for oil, and transportation of natural gas have all contributed to a doubling of the amount of atmospheric methane since 1800. Today nearly 300,000 wells yearly produce ca. 21 trillion cubic feet of methane. Known reserves suggest about a 10 year supply at the above rates of recovery; and the potential for undiscovered resources is obscured by uncertainty involving price, new technologies, and environmental restrictions steming from the need to drill an enormous number of wells, many in ecologically sensitive areas. Until all these aspects of methane are better understood, its future role in the world`s energy mix will remain uncertain. The atomic simplicity of methane, composed of one carbon and four hydrogen atoms, may mask the complexity and importance of this, the most basic of organic molecules. Within the Earth, methane is produced through thermochemical alteration of organic materials, and by biochemical reactions mediated by metabolic processes of archaebacteria; some methane may even be primordial, a residue of planetary accretion. Methane also occurs in smaller volumes in landfills, rice paddies, termite complexes, ruminants, and even many humans. As an energy source, its full energy potential is controversial. Methane is touted by some as a viable bridge to future energy systems, fueled by the sun and uranium and carried by electricity and hydrogen.

  15. Characterization of Methane Degradation and Methane-Degrading Microbes in Alaska Coastal Water

    SciTech Connect (OSTI)

    David Kirchman

    2011-12-31

    The net flux of methane from methane hydrates and other sources to the atmosphere depends on methane degradation as well as methane production and release from geological sources. The goal of this project was to examine methane-degrading archaea and organic carbon oxidizing bacteria in methane-rich and methane-poor sediments of the Beaufort Sea, Alaska. The Beaufort Sea system was sampled as part of a multi-disciplinary expedition (??Methane in the Arctic Shelf? or MIDAS) in September 2009. Microbial communities were examined by quantitative PCR analyses of 16S rRNA genes and key methane degradation genes (pmoA and mcrA involved in aerobic and anaerobic methane degradation, respectively), tag pyrosequencing of 16S rRNA genes to determine the taxonomic make up of microbes in these sediments, and sequencing of all microbial genes (??metagenomes?). The taxonomic and functional make-up of the microbial communities varied with methane concentrations, with some data suggesting higher abundances of potential methane-oxidizing archaea in methane-rich sediments. Sequence analysis of PCR amplicons revealed that most of the mcrA genes were from the ANME-2 group of methane oxidizers. According to metagenomic data, genes involved in methane degradation and other degradation pathways changed with sediment depth along with sulfate and methane concentrations. Most importantly, sulfate reduction genes decreased with depth while the anaerobic methane degradation gene (mcrA) increased along with methane concentrations. The number of potential methane degradation genes (mcrA) was low and inconsistent with other data indicating the large impact of methane on these sediments. The data can be reconciled if a small number of potential methane-oxidizing archaea mediates a large flux of carbon in these sediments. Our study is the first to report metagenomic data from sediments dominated by ANME-2 archaea and is one of the few to examine the entire microbial assemblage potentially

  16. CO2 and CH4 Surface Flux, Soil Profile Concentrations, and Stable Isotope Composition, Barrow, Alaska, 2012-2013

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Curtis, J.B.; Vaughn, L.S.; Torn, M.S.; Conrad, M.S.; Chafe, O.; Bill, M.

    2015-12-31

    In August-October 2012 and June-October 2013, co-located measurements were made of surface CH4 and CO2 flux, soil pore space concentrations and stable isotope compositions of CH4 and CO2, and subsurface temperature and soil moisture. Measurements were made in intensive study site 1 areas A, B, and C, and from the site 0 and AB transects, from high-centered, flat-centered, and low-centered polygons, from the center, edge, and trough of each polygon.

  17. A microbial functional group-based module for simulating methane production and consumption: Application to an incubated permafrost soil

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xu, Xiaofeng; Elias, Dwayne A.; Graham, David E.; Phelps, Tommy J.; Carroll, Sue L.; Wullschleger, Stan D.; Thornton, Peter E.

    2015-07-23

    In this study, accurately estimating methane (CH4) flux is critically important for investigating and predicting the biogeochemistry-climate feedback. Better simulating CH4 flux requires explicit representations of microbial processes on CH4 dynamics because all processes for CH4 production and consumption are actually carried out by microbes. A microbial functional group based module was developed and tested against an incubation experiment. The module considers four key mechanisms for CH4 production and consumption: methanogenesis from acetate or single-carbon compounds and CH4 oxidation using molecular oxygen or other inorganic electron acceptors. These four processes were carried out by four microbial functional groups: acetoclastic methanogens,more » hydrogenotrophic methanogens, aerobic methanotrophs, and anaerobic methanotrophs. This module was then linked with the decomposition subroutine of the Community Land Model, and was further used to simulate dynamics of carbon dioxide (CO2) and CH4 concentrations from an incubation experiment with permafrost soils. The results show that the model could capture the dynamics of CO2 and CH4 concentrations in microcosms with top soils, mineral layer soils and permafrost soils under natural and saturated moisture conditions and a temperature gradient of -2°C, 3°C, and 5°C. Sensitivity analysis confirmed the importance of acetic acid's direct contribution as substrate and indirect effects through pH feedback on CO2 and CH4 production and consumption. This study suggests that representing the microbial mechanisms is critical for modeling CH4 production and consumption; it is urgent to incorporate microbial mechanisms into Earth system models for better predicting the behavior of the climate system.« less

  18. Final Scientific/Technical Report. A closed path methane and water vapor gas analyzer

    SciTech Connect (OSTI)

    Xu, Liukang; McDermitt, Dayle; Anderson, Tyler; Riensche, Brad; Komissarov, Anatoly; Howe, Julie

    2012-02-01

    Robust, economical, low-power and reliable closed-path methane (CH4), carbon dioxide (CO2), and water vapor (H2O) analyzers suitable for long-term measurements are not readily available commercially. Such analyzers are essential for quantifying the amount of CH4 and CO2 released from various ecosystems (wetlands, rice paddies, forests, etc.) and other surface contexts (e.g. landfills, animal husbandry lots, etc.), and for understanding the dynamics of the atmospheric CH4 and CO2 budget and their impact on climate change and global warming. The purpose of this project is to develop a closed-path methane, carbon dioxide gas and water vapor analyzer capable of long-term measurements in remote areas for global climate change and environmental research. The analyzer will be capable of being deployed over a wide range of ecosystems to understand methane and carbon dioxide exchange between the atmosphere and the surface. Measurements of methane and carbon dioxide exchange need to be made all year-round with limited maintenance requirements. During this Phase II effort, we successfully completed the design of the electronics, optical bench, trace gas detection method and mechanical infrastructure. We are using the technologies of two vertical cavity surface emitting lasers, a multiple-pass Herriott optical cell, wavelength modulation spectroscopy and direct absorption to measure methane, carbon dioxide, and water vapor. We also have designed the instrument application software, Field Programmable Gate Array (FPGA), along with partial completion of the embedded software. The optical bench has been tested in a lab setting with very good results. Major sources of optical noise have been identified and through design, the optical noise floor is approaching -60dB. Both laser modules can be temperature controlled to help maximize the stability of the analyzer. Additionally, a piezo electric transducer has been

  19. The Young Planet-mass Ob ject 2M1207b: A cool, cloudy, and methane...

    Office of Scientific and Technical Information (OSTI)

    A cool, cloudy, and methane-poor atmosphere Citation Details In-Document Search Title: The Young Planet-mass Ob ject 2M1207b: A cool, cloudy, and methane-poor atmosphere You ...

  20. ARM - Methane Background Information

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    WarmingMethane Background Information Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Methane Background Information What is Methane? Why Do We Use Methane? How is Methane Made? Where Do We Find Methane? Can Methane Be Dangerous? Does Methane Contribute to Climate Change? What is Methane?

  1. Methane Hydrates

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Methane Hydrates 2016 Methane Hydrates Funding Opportunity Announcement The objective of this Funding Opportunity Announcement is to select projects in FY16 that will further ongoing programmatic efforts to characterize naturally occurring gas hydrate deposits as well as their role in the natural environment and that will: Support fundamental laboratory and numerical simulation studies of gas hydrate reservoir response to potential production activities Support fundamental field, laboratory and

  2. The terrestrial biosphere as a net source of greenhouse gases to the atmosphere

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tian, Hanqin; Lu, Chaoqun; Ciais, Philippe; Michalak, Anna M.; Canadell, Josep G.; Saikawa, Eri; Huntzinger, Deborah N.; Gurney, Kevin R; Sitch, Stephen; Zhang, Bowen; et al

    2016-03-09

    The terrestrial biosphere can release or absorb the greenhouse gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), and therefore has an important role in regulating atmospheric composition and climate1. Anthropogenic activities such as land-use change, agriculture and waste management have altered terrestrial biogenic greenhouse gas fluxes, and the resulting increases in methane and nitrous oxide emissions in particular can contribute to climate change2, 3. The terrestrial biogenic fluxes of individual greenhouse gases have been studied extensively4, 5, 6, but the net biogenic greenhouse gas balance resulting from anthropogenic activities and its effect on the climate system remains uncertain.more » Here we use bottom-up (inventory, statistical extrapolation of local flux measurements, and process-based modelling) and top-down (atmospheric inversions) approaches to quantify the global net biogenic greenhouse gas balance between 1981 and 2010 resulting from anthropogenic activities and its effect on the climate system. We find that the cumulative warming capacity of concurrent biogenic methane and nitrous oxide emissions is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake from 2001 to 2010. This results in a net positive cumulative impact of the three greenhouse gases on the planetary energy budget, with a best estimate (in petagrams of CO2 equivalent per year) of 3.9 ± 3.8 (top down) and 5.4 ± 4.8 (bottom up) based on the GWP100 metric (global warming potential on a 100-year time horizon). Lastly, our findings suggest that a reduction in agricultural methane and nitrous oxide emissions, particularly in Southern Asia, may help mitigate climate change.« less

  3. Capping methane leaks a win-win

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Capping methane leaks a win-win Capping methane leaks a win-win As special correspondent Kathleen McCleery explains, that's why both environmentalists and the energy industry are trying to find ways to capture leaks from oil and gas facilities. November 13, 2015 Capping methane leaks a win-win Methane, the primary component of natural gas, is also a potent greenhouse gas, trapping energy in the atmosphere. Last year NASA released satellite images showing a hot spot in the area where New Mexico,

  4. Observation of CH4 and other Non-CO2 Green House Gas Emissions from California

    SciTech Connect (OSTI)

    Fischer, Marc L.; Zhao, Chuanfeng; Riley, William J.; Andrews, Arlyn C.

    2009-01-09

    In 2006, California passed the landmark assembly bill AB-32 to reduce California's emissions of greenhouse gases (GHGs) that contribute to global climate change. AB-32 commits California to reduce total GHG emissions to 1990 levels by 2020, a reduction of 25 percent from current levels. To verify that GHG emission reductions are actually taking place, it will be necessary to measure emissions. We describe atmospheric inverse model estimates of GHG emissions obtained from the California Greenhouse Gas Emissions Measurement (CALGEM) project. In collaboration with NOAA, we are measuring the dominant long-lived GHGs at two tall-towers in central California. Here, we present estimates of CH{sub 4} emissions obtained by statistical comparison of measured and predicted atmospheric mixing ratios. The predicted mixing ratios are calculated using spatially resolved a priori CH{sub 4} emissions and surface footprints, that provide a proportional relationship between the surface emissions and the mixing ratio signal at tower locations. The footprints are computed using the Weather Research and Forecast (WRF) coupled to the Stochastic Time-Inverted Lagrangian Transport (STILT) model. Integral to the inverse estimates, we perform a quantitative analysis of errors in atmospheric transport and other factors to provide quantitative uncertainties in estimated emissions. Regressions of modeled and measured mixing ratios suggest that total CH{sub 4} emissions are within 25% of the inventory estimates. A Bayesian source sector analysis obtains posterior scaling factors for CH{sub 4} emissions, indicating that emissions from several of the sources (e.g., landfills, natural gas use, petroleum production, crops, and wetlands) are roughly consistent with inventory estimates, but livestock emissions are significantly higher than the inventory. A Bayesian 'region' analysis is used to identify spatial variations in CH{sub 4} emissions from 13 sub-regions within California. Although, only

  5. WETCHIMP-WSL: Intercomparison of wetland methane emissions models over West Siberia

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bohn, T. J.; Melton, J. R.; Ito, A.; Kleinen, T.; Spahni, R.; Stocker, B. D.; Zhang, B.; Zhu, X.; Schroeder, R.; Glagolev, M. V.; et al

    2015-06-03

    Wetlands are the world's largest natural source of methane, a powerful greenhouse gas. The strong sensitivity of methane emissions to environmental factors such as soil temperature and moisture has led to concerns about potential positive feedbacks to climate change. This risk is particularly relevant at high latitudes, which have experienced pronounced warming and where thawing permafrost could potentially liberate large amounts of labile carbon over the next 100 years. However, global models disagree as to the magnitude and spatial distribution of emissions, due to uncertainties in wetland area and emissions per unit area and a scarcity of in situ observations.more » Recent intensive field campaigns across the West Siberian Lowland (WSL) make this an ideal region over which to assess the performance of large-scale process-based wetland models in a high-latitude environment. Here we present the results of a follow-up to the Wetland and Wetland CH4 Intercomparison of Models Project (WETCHIMP), focused on the West Siberian Lowland (WETCHIMP-WSL). We assessed 21 models and 5 inversions over this domain in terms of total CH4 emissions, simulated wetland areas, and CH4 fluxes per unit wetland area and compared these results to an intensive in situ CH4 flux data set, several wetland maps, and two satellite surface water products. We found that (a) despite the large scatter of individual estimates, 12-year mean estimates of annual total emissions over the WSL from forward models (5.34 ± 0.54 Tg CH4 yr⁻¹), inversions (6.06 ± 1.22 Tg CH4 yr⁻¹), and in situ observations (3.91 ± 1.29 Tg CH4 yr⁻¹) largely agreed; (b) forward models using surface water products alone to estimate wetland areas suffered from severe biases in CH4 emissions; (c) the interannual time series of models that lacked either soil thermal physics appropriate to the high latitudes or realistic emissions from unsaturated peatlands tended to be dominated by a single environmental driver

  6. Review of the findings of the Ignik Sikumi CO2-CH4 gas hydrate exchange field trial

    SciTech Connect (OSTI)

    Anderson, Brian J.; Boswell, Ray; Collett, Tim S.; Farrell, Helen; Ohtsuka, Satoshi; White, Mark D.

    2014-08-01

    The Ignik Sikumi Gas Hydrate Exchange Field Trial was conducted by ConocoPhillips in partnership with the U.S. Department of Energy, the Japan Oil, Gas, and Metals National Corporation, and the U.S. Geological Survey within the Prudhoe Bay Unit on the Alaska North Slope (ANS) during 2011 and 2012. The 2011 field program included drilling the vertical test well and performing extensive wireline logging through a thick section of gas-hydrate-bearing sand reservoirs that provided substantial new insight into the nature of ANS gas hydrate occurrences. The 2012 field program involved an extended, scientific field trial conducted within a single vertical well (“huff-and-puff” design) through three primary operational phases: 1) injection of a gaseous phase mixture of CO2, N2, and chemical tracers; 2) flowback conducted at down-hole pressures above the stability threshold for native CH4-hydrate, and 3) extended (30-days) flowback at pressures below the stability threshold of native CH4-hydrate. Ignik Sikumi represents the first field investigation of gas hydrate response to chemical injection, and the longest-duration field reservoir response experiment yet conducted. Full descriptions of the operations and data collected have been fully reported by ConocoPhillips and are available to the science community. The 2011 field program indicated the presence of free water within the gas hydrate reservoir, a finding with significant implications to the design of the exchange trial – most notably the use of a mixed gas injectant. While this decision resulted in a complex chemical environment within the reservoir that greatly tests current experimental and modeling capabilities – without such a mixture, it is apparent that injection could not have been achieved. While interpretation of the field data are continuing, the primary scientific findings and implications of the program are: 1) gas hydrate destabilizing is self-limiting, dispelling any notion of the potential for

  7. Techno-Economic Analysis of Bioconversion of Methane into Biofuel and Biochemical (Poster)

    SciTech Connect (OSTI)

    Fei, Q.; Tao, L.; Pienkos, P .T.; Guarnieri, M.; Palou-Rivera, I.

    2014-10-01

    In light of the relatively low price of natural gas and increasing demands of liquid transportation fuels and high-value chemicals, attention has begun to turn to novel biocatalyst for conversion of methane (CH4) into biofuels and biochemicals [1]. A techno-economic analysis (TEA) was performed for an integrated biorefinery process using biological conversion of methane, such as carbon yield, process efficiency, productivity (both lipid and acid), natural gas and other raw material prices, etc. This analysis is aimed to identify research challenges as well provide guidance for technology development.

  8. Matrix Shrinkage and Swelling Effects on Economics of Enhanced Coalbed Methane Production and CO2 Sequestration in Coal

    SciTech Connect (OSTI)

    Gorucu, F.B.; Jikich, S.A.; Bromhal, G.S.; Sams, W.N.; Ertekin, T.; Smith, D.H.

    2005-09-01

    Increases in CO2 levels in the atmosphere and their contributions to global climate change have been a major concern. It has been shown that CO2 injection can enhance the methane recovery from coal. Accordingly, sequestration costs can be partially offset by the value added product. Indeed, coal seam sequestration may be profitable, particularly with the introduction of incentives for CO2 sequestration. Hence, carbon dioxide sequestration in unmineable coals is a very attractive option, not only for environmental reasons, but also for possible economic benefits. Darcy flow through cleats is an important transport mechanism in coal. Cleat compression and permeability changes due to gas sorption desorption, changes of effective stress, and matrix swelling and shrinkage introduce a high level of complexity into the feasibility of a coal sequestration project. The economic effects of carbon dioxide-induced swelling on permeabilities and injectivities has received little (if any) detailed attention. Carbon dioxide and methane have different swelling effects on coal. In this work, the Palmer-Mansoori model for coal shrinkage and permeability increases during primary methane production was re-written to also account for coal swelling caused by carbon dioxide sorption. The generalized model was added to PSU-COALCOMP, a dual porosity reservoir simulator for primary and enhanced coalbed methane production. A standard five-spot of vertical wells and representative coal properties for Appalachian coals were used.[1] Simulations and sensitivity analyses were performed with the modified simulator for nine different parameters, including coal seam and operational parameters and economic criteria. The coal properties and operating parameters that were varied included Youngs modulus, Poissons ratio, the cleat porosity, and the injection pressure. The economic variables included CH4 price, CO2 cost, CO2 credit, water disposal cost, and interest rate. Net present value analyses of

  9. Quantification of the Potential Gross Economic Impacts of Five Methane Reduction Scenarios

    Office of Energy Efficiency and Renewable Energy (EERE)

    This study assessed five potential methane reduction scenarios from natural gas transmission, storage, and distribution (TS&D) infrastructure using published literature on the costs and the estimated quantity of methane reduced. The results show that implementation of these five measures could support approximately 85,000 jobs annually from 2015 to 2019 and reduce CH4 emissions from natural gas TS&D by over 40%. Based on standard input/output analysis methodology, measures are estimated to support over $8 billion in GDP annually over the same time period and allow producers to recover approximately $912 million annually in captured gas. Mitigation of methane emission reductions through repair, replacement and new technologies are found to support economic development and jobs. The study also found that a portfolio approach to infrastructure modernization may be appropriate to meaningfully improve safety, maintain or create high levels of employment, and significant losses of methane from across TS&D segments of natural gas systems.

  10. Ammonia and methane dairy emissions in the San Joaquin Valley of California from individual feedlot to regional scale

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Miller, David J.; Sun, Kang; Tao, Lei; Nowak, John B.; Liu, Zhen; Diskin, Glenn; Sasche, Glen; Beyersdorf, Andreas; Ferrare, Richard; Scarino, Amy Jo; et al

    2015-09-27

    Agricultural ammonia (NH3) emissions are highly uncertain, with high spatiotemporal variability and a lack of widespread in situ measurements. Regional NH3 emission estimates using mass balance or emission ratio approaches are uncertain due to variable NH3 sources and sinks as well as unknown plume correlations with other dairy source tracers. We characterize the spatial distributions of NH3 and methane (CH4) dairy plumes using in situ surface and airborne measurements in the Tulare dairy feedlot region of the San Joaquin Valley, California, during the NASA Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality 2013more » field campaign. Surface NH3 and CH4 mixing ratios exhibit large variability with maxima localized downwind of individual dairy feedlots. The geometric mean NH3:CH4 enhancement ratio derived from surface measurements is 0.15 ± 0.03 ppmv ppmv–1. Individual dairy feedlots with spatially distinct NH3 and CH4 source pathways led to statistically significant correlations between NH3 and CH4 in 68% of the 69 downwind plumes sampled. At longer sampling distances, the NH3:CH4 enhancement ratio decreases 20–30%, suggesting the potential for NH3 deposition as a loss term for plumes within a few kilometers downwind of feedlots. Aircraft boundary layer transect measurements directly above surface mobile measurements in the dairy region show comparable gradients and geometric mean enhancement ratios within measurement uncertainties, even when including NH3 partitioning to submicron particles. Individual NH3 and CH4 plumes sampled at close proximity where losses are minimal are not necessarily correlated due to lack of mixing and distinct source pathways. As a result, our analyses have important implications for constraining NH3 sink and plume variability influences on regional NH3 emission estimates and for improving NH3 emission inventory spatial allocations.« less

  11. Methane Credit | Open Energy Information

    Open Energy Info (EERE)

    Methane Credit Jump to: navigation, search Name: Methane Credit Place: Charlotte, North Carolina Zip: 28273 Product: Specialises in utilising methane produced on municipal landfill...

  12. Methane Recovery from Hydrate-bearing Sediments

    SciTech Connect (OSTI)

    J. Carlos Santamarina; Costas Tsouris

    2011-04-30

    emphasis; (6) detailed study of CH4-CO2 exchange as a unique alternative to recover CH4 gas while sequestering CO2; (7) the relevance of fines in otherwise clean sand sediments on gas recovery and related phenomena such as fines migration and clogging, vuggy structure formation, and gas-driven fracture formation during gas production by depressurization.

  13. Methane enrichment digestion experiments at the anaerobic experimental test unit at Walt Disney World. Final report, March 1989-August 1990

    SciTech Connect (OSTI)

    Srivastava, V.J.; Hill, A.H.

    1993-06-01

    The goal of the project was to determine the technical feasibility of utilizing a novel concept in anaerobic digestion, in-situ methane enrichment digestion or MED for producing utility-grade gas from a pilot-scale anaerobic digester. MED tests conducted during this program consistently achieved digester product gas with a methane (CH4) content of greater than 90% (on a dry-, nitrogen-free basis). The MED concept, because it requires relatively simple equipment and modest energy input, has the potential to simplify gas cleanup requirements and substantially reduce the cost of converting wastes and biomass to pipeline quality gas.

  14. Assessing methane oxidation under landfill covers and its contribution to the above atmospheric CO{sub 2} levels: The added value of the isotope ({delta}{sup 13}C and {delta}{sup 18}O CO{sub 2}; {delta}{sup 13}C and {delta}D CH{sub 4}) approach

    SciTech Connect (OSTI)

    Widory, D.; Proust, E.; Bellenfant, G.; Bour, O.

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Comparison of the isotope and mass balance approaches to evaluate the level of methane oxidation within a landfill. Black-Right-Pointing-Pointer The level of methane oxidation is not homogenous under the landfill cover and is strongly correlated to the methane flux. Black-Right-Pointing-Pointer Isotope tracking of the contribution of the methane oxidation to the CO{sub 2} concentrations in the ambient air. - Abstract: We are presenting here a multi-isotope approach ({delta}{sup 13}C and {delta}{sup 18}O of CO{sub 2}; {delta}{sup 13}C and {delta}D of CH{sub 4}) to assess (i) the level(s) of methane oxidation during waste biodegradation and its migration through a landfill cover in Sonzay (France), and (ii) its contribution to the atmospheric CO{sub 2} levels above the surface. The isotope approach is compared to the more conventional mass balance approach. Results from the two techniques are comparable and show that the CH{sub 4} oxidation under the landfill cover is heterogenous, with low oxidation percentages in samples showing high biogas fluxes, which was expected in clay covers presenting fissures, through which CH{sub 4} is rapidly transported. At shallow depth, more immobile biogas pockets show a higher level of CH{sub 4} oxidation by the methanotrophic bacteria. {delta}{sup 13}C of CO{sub 2} samples taken at different heights (from below the cover up to 8 m above the ground level) were also used to identify and assess the relative contributions of its main sources both under the landfill cover and in the surrounding atmosphere.

  15. Gettering of Hydrogen and Methane from a Helium Gas Mixture

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Cardenas, Rosa E.; Stewart, Kenneth D.; Cowgill, Donald F.

    2014-10-21

    In our study, the authors developed an approach for accurately quantifying the helium content in a gas mixture also containing hydrogen and methane using commercially available getters. The authors performed a systematic study to examine how both H2 and CH4 can be removed simultaneously from the mixture using two SAES St 172® getters operating at different temperatures. The remaining He within the gas mixture can then be measured directly using a capacitance manometer. Moreover, the optimum combination involved operating one getter at 650°C to decompose the methane, and the second at 110°C to remove the hydrogen. Finally, this approach eliminatedmore » the need to reactivate the getters between measurements, thereby enabling multiple measurements to be made within a short time interval, with accuracy better than 1%. The authors anticipate that such an approach will be particularly useful for quantifying the He-3 in mixtures that include tritium, tritiated methane, and helium-3. The presence of tritiated methane, generated by tritium activity, often complicates such measurements.« less

  16. Gettering of Hydrogen and Methane from a Helium Gas Mixture

    SciTech Connect (OSTI)

    Cardenas, Rosa E.; Stewart, Kenneth D.; Cowgill, Donald F.

    2014-10-21

    In our study, the authors developed an approach for accurately quantifying the helium content in a gas mixture also containing hydrogen and methane using commercially available getters. The authors performed a systematic study to examine how both H2 and CH4 can be removed simultaneously from the mixture using two SAES St 172® getters operating at different temperatures. The remaining He within the gas mixture can then be measured directly using a capacitance manometer. Moreover, the optimum combination involved operating one getter at 650°C to decompose the methane, and the second at 110°C to remove the hydrogen. Finally, this approach eliminated the need to reactivate the getters between measurements, thereby enabling multiple measurements to be made within a short time interval, with accuracy better than 1%. The authors anticipate that such an approach will be particularly useful for quantifying the He-3 in mixtures that include tritium, tritiated methane, and helium-3. The presence of tritiated methane, generated by tritium activity, often complicates such measurements.

  17. ARM - Methane Gas

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Methane Gas Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Methane Gas Methane gas is another naturally occurring greenhouse gas. It is produced as a result of microbial activity in the absence of oxygen. Pre-industrial concentrations of methane were about 700 ppb and in 1994 they were up

  18. Methane Hydrate Program

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    FY 2011 Methane Hydrate Program Report to Congress July 2012 United States Department of Energy Washington, DC 20585 Department of Energy | July 2012 FY 2011 Methane Hydrate Program Report to Congress | Page ii Message from the Secretary Section 968 of the Energy Policy Act of 2005 requires the Department of Energy to submit to Congress an annual report on the results of methane hydrate research. I am pleased to submit the enclosed report entitled U.S. Department of Energy FY 2011 Methane

  19. Heat pipe methanator

    DOE Patents [OSTI]

    Ranken, William A.; Kemme, Joseph E.

    1976-07-27

    A heat pipe methanator for converting coal gas to methane. Gravity return heat pipes are employed to remove the heat of reaction from the methanation promoting catalyst, transmitting a portion of this heat to an incoming gas pre-heat section and delivering the remainder to a steam generating heat exchanger.

  20. Wetland (peat) Carbon Cycle

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    wetland peat carbon cycle Wetland (peat) Carbon Cycle Methane (CH4) is an important greenhouse gas, twenty times more potent than CO2, but atmospheric concentrations of CH4 under future climate change are uncertain. This is in part because many climate-sensitive ecosystems release both CH4 and carbon dioxide (CO2) and it is unknown how these systems will partition future releases of carbon to the atmosphere. Ecosystem observations of CH4 emissions lack mechanistic links to the processes that

  1. Methane Hydrate | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Methane Hydrate Methane Hydrate Types of Methane Hydrate Deposits Types of Methane Hydrate Deposits Methane hydrate is a cage-like lattice of ice inside of which are trapped molecules of methane, the chief constituent of natural gas. If methane hydrate is either warmed or depressurized, it will revert back to water and natural gas. When brought to the earth's surface, one cubic meter of gas hydrate releases 164 cubic meters of natural gas. Hydrate deposits may be several hundred meters thick and

  2. Using Carbon Dioxide to Enhance Recovery of Methane from Gas Hydrate Reservoirs: Final Summary Report

    SciTech Connect (OSTI)

    McGrail, B. Peter; Schaef, Herbert T.; White, Mark D.; Zhu, Tao; Kulkarni, Abhijeet S.; Hunter, Robert B.; Patil, Shirish L.; Owen, Antionette T.; Martin, P F.

    2007-09-01

    Carbon dioxide sequestration coupled with hydrocarbon resource recovery is often economically attractive. Use of CO2 for enhanced recovery of oil, conventional natural gas, and coal-bed methane are in various stages of common practice. In this report, we discuss a new technique utilizing CO2 for enhanced recovery of an unconventional but potentially very important source of natural gas, gas hydrate. We have focused our attention on the Alaska North Slope where approximately 640 Tcf of natural gas reserves in the form of gas hydrate have been identified. Alaska is also unique in that potential future CO2 sources are nearby, and petroleum infrastructure exists or is being planned that could bring the produced gas to market or for use locally. The EGHR (Enhanced Gas Hydrate Recovery) concept takes advantage of the physical and thermodynamic properties of mixtures in the H2O-CO2 system combined with controlled multiphase flow, heat, and mass transport processes in hydrate-bearing porous media. A chemical-free method is used to deliver a LCO2-Lw microemulsion into the gas hydrate bearing porous medium. The microemulsion is injected at a temperature higher than the stability point of methane hydrate, which upon contacting the methane hydrate decomposes its crystalline lattice and releases the enclathrated gas. Small scale column experiments show injection of the emulsion into a CH4 hydrate rich sand results in the release of CH4 gas and the formation of CO2 hydrate

  3. Methane Hydrate Field Program

    SciTech Connect (OSTI)

    2013-12-31

    This final report document summarizes the activities undertaken and the output from three primary deliverables generated during this project. This fifteen month effort comprised numerous key steps including the creation of an international methane hydrate science team, determining and reporting the current state of marine methane hydrate research, convening an international workshop to collect the ideas needed to write a comprehensive Marine Methane Hydrate Field Research Plan and the development and publication of that plan. The following documents represent the primary deliverables of this project and are discussed in summary level detail in this final report. • Historical Methane Hydrate Project Review Report • Methane Hydrate Workshop Report • Topical Report: Marine Methane Hydrate Field Research Plan • Final Scientific/Technical Report

  4. Methane Hydrate Field Studies

    Broader source: Energy.gov [DOE]

    Since 2001, DOE has conducted field trials of exploration and production technology in the Alaska North Slope. Although Alaska methane hydrate resources are smaller than marine deposits and...

  5. Comparison of Propane and Methane Performance and Emissions in a Turbocharged Direct Injection Dual Fuel Engine

    SciTech Connect (OSTI)

    Gibson, C. M.; Polk, A. C.; Shoemaker, N. T.; Srinivasan, K. K.; Krishnan, S. R.

    2011-01-01

    With increasingly restrictive NO x and particulate matter emissions standards, the recent discovery of new natural gas reserves, and the possibility of producing propane efficiently from biomass sources, dual fueling strategies have become more attractive. This paper presents experimental results from dual fuel operation of a four-cylinder turbocharged direct injection (DI) diesel engine with propane or methane (a natural gas surrogate) as the primary fuel and diesel as the ignition source. Experiments were performed with the stock engine control unit at a constant speed of 1800 rpm, and a wide range of brake mean effective pressures (BMEPs) (2.7-11.6 bars) and percent energy substitutions (PESs) of C 3 H 8 and CH 4. Brake thermal efficiencies (BTEs) and emissions (NO x, smoke, total hydrocarbons (THCs), CO, and CO 2) were measured. Maximum PES levels of about 80-95% with CH 4 and 40-92% with C 3 H 8 were achieved. Maximum PES was limited by poor combustion efficiencies and engine misfire at low loads for both C 3 H 8 and CH 4, and the onset of knock above 9 bar BMEP for C 3 H 8. While dual fuel BTEs were lower than straight diesel BTEs at low loads, they approached diesel BTE values at high loads. For dual fuel operation, NO x and smoke reductions (from diesel values) were as high as 66-68% and 97%, respectively, but CO and THC emissions were significantly higher with increasing PES at all engine loads

  6. Methanation assembly using multiple reactors

    DOE Patents [OSTI]

    Jahnke, Fred C.; Parab, Sanjay C.

    2007-07-24

    A methanation assembly for use with a water supply and a gas supply containing gas to be methanated in which a reactor assembly has a plurality of methanation reactors each for methanating gas input to the assembly and a gas delivery and cooling assembly adapted to deliver gas from the gas supply to each of said methanation reactors and to combine water from the water supply with the output of each methanation reactor being conveyed to a next methanation reactor and carry the mixture to such next methanation reactor.

  7. Coalbed Methane (CBM) is natural

    Broader source: Energy.gov (indexed) [DOE]

    and continued ural gas liquids and crude oil, which have a higher value in energy ... Submersible pump Coal Methane released from coal Methane to pipeline Water (discharged) ...

  8. The European land and inland water CO2, CO, CH4 and N2O balance between 2001 and 2005

    SciTech Connect (OSTI)

    Luyassaert, S; Abril, G; Andres, Robert Joseph; Bastviken, D; Bellassen, V; Bergamaschi, P; Bousquet, P; Chevallier, F; Ciais, P.; Dechow, R; Erb, K-H; Etiope, G; Fortems-Cheiney, A; Grassi, G; Hartmann, J; Jung, M.; Lathiere, J; Lohila, A; Mayorga, E; Moosdorf, N; Njakou, D; Otto, J; Papale, D.; Peters, W; Peylin, P; Raymond, Peter A; Rodenbeck, C; Saarnio, S; Schulze, E.-D.; Szopa, S; Thompson, R; Verkerk, P; Vuichard, N; Wang, R; Wattenbach, M; Zaehle, S

    2012-01-01

    Globally, terrestrial ecosystems have absorbed about 30% of anthropogenic greenhouse gas emissions over the period 2000-2007 and inter-hemispheric gradients indicate that a significant fraction of terrestrial carbon sequestration must be north of the Equator. We present a compilation of the CO{sub 2}, CO, CH{sub 4} and N{sub 2}O balances of Europe following a dual constraint approach in which (1) a land-based balance derived mainly from ecosystem carbon inventories and (2) a land-based balance derived from flux measurements are compared to (3) the atmospheric data-based balance derived from inversions constrained by measurements of atmospheric GHG (greenhouse gas) concentrations. Good agreement between the GHG balances based on fluxes (1294 {+-} 545 Tg C in CO{sub 2}-eq yr{sup -1}), inventories (1299 {+-} 200 Tg C in CO{sub 2}-eq yr{sup -1}) and inversions (1210 {+-} 405 Tg C in CO{sub 2}-eq yr{sup -1}) increases our confidence that the processes underlying the European GHG budget are well understood and reasonably sampled. However, the uncertainty remains large and largely lacks formal estimates. Given that European net land to atmosphere exchanges are determined by a few dominant fluxes, the uncertainty of these key components needs to be formally estimated before efforts could be made to reduce the overall uncertainty. The net land-to-atmosphere flux is a net source for CO{sub 2}, CO, CH{sub 4} and N{sub 2}O, because the anthropogenic emissions by far exceed the biogenic sink strength. The dual-constraint approach confirmed that the European biogenic sink removes as much as 205 {+-} 72 Tg C yr{sup -1} from fossil fuel burning from the atmosphere. However, This C is being sequestered in both terrestrial and inland aquatic ecosystems. If the C-cost for ecosystem management is taken into account, the net uptake of ecosystems is estimated to decrease by 45% but still indicates substantial C-sequestration. However, when the balance is extended from CO{sub 2} towards

  9. TITAN'S TRANSPORT-DRIVEN METHANE CYCLE

    SciTech Connect (OSTI)

    Mitchell, Jonathan L.

    2012-09-10

    The mechanisms behind the occurrence of large cloud outbursts and precipitation on Titan have been disputed. A global- and annual-mean estimate of surface fluxes indicated only 1% of the insolation, or {approx}0.04 W m{sup -2}, is exchanged as sensible and/or latent fluxes. Since these fluxes are responsible for driving atmospheric convection, it has been argued that moist convection should be quite rare and precipitation even rarer, even if evaporation globally dominates the surface-atmosphere energy exchange. In contrast, climate simulations indicate substantial cloud formation and/or precipitation. We argue that the top-of-atmosphere (TOA) radiative imbalance is diagnostic of horizontal heat transport by Titan's atmosphere, and thus constrains the strength of the methane cycle. Simple calculations show the TOA radiative imbalance is {approx}0.5-1 W m{sup -2} in Titan's equatorial region, which implies 2-3 MW of latitudinal heat transport by the atmosphere. Our simulation of Titan's climate suggests this transport may occur primarily as latent heat, with net evaporation at the equator and net accumulation at higher latitudes. Thus, the methane cycle could be 10-20 times previous estimates. Opposing seasonal transport at solstices, compensation by sensible heat transport, and focusing of precipitation by large-scale dynamics could further enhance the local, instantaneous strength of Titan's methane cycle by a factor of several. A limited supply of surface liquids in regions of large surface radiative imbalance may throttle the methane cycle, and if so, we predict more frequent large storms over the lakes district during Titan's northern summer.

  10. Seasonal Production and Emission of Methane from Rice Fields, Final Report

    SciTech Connect (OSTI)

    Khalil, M. Aslam K.; Rasmussen,Reinhold A.

    2002-12-03

    B 139 - Methane (CH4) is a greenhouse gas regarded second only to carbon dioxide in its ability to cause global warming. Methane is important because of its relatively fast increase, and also because it is, per molecule, some 60 times more effective than carbon dioxide in causing global warming. The largest present anthropogenic sources of methane are rice fields, cattle and biomass burning. The global emissions from these sources are still not well known. In the middle 1980s there were few available data on methane emissions from rice fields leading to estimates of a global source between 100-280 Tg/yr. Extensive worldwide research during the last decade has shown that the global emissions from rice fields are more likely to be in the range of 30-80Tg/yr. While this work has led to a substantial reduction in the estimated emissions, the uncertainty is still quite large, and seriously affects our ability to include methane in integrated assessments for future climate change and environmental management.China dominated estimates of methane emissions from rice fields because it was, and is, the largest producer of rice, and major increases in rice production had taken place in the country over the last several decades. This report summarizes the work in Sichuan Province, China, in each of the following areas: the design of the experiment; the main results on methane emissions from rice fields, delineating the factors controlling emissions; production of methane in the soil; a survey of water management practices in sample of counties in Sichuan province; and results of ambient measurements including data from the background continental site. B139

  11. Understanding the nature of methane emission from rice ecosystems as basis of mitigation strategies

    SciTech Connect (OSTI)

    Buendia, L.V.; Neue, H.U.; Wassmann, R.

    1996-12-31

    Methane is considered as an important Greenhouse gas and rice fields are one of the major atmospheric methane sources. The paper aims to develop sampling strategies and formulate mitigation options based on diel (day and night) and seasonal pattern of methane emission. The study was conducted in 4 countries to measure methane flux using an automatic closed chamber system. A 24-hour bihourly methane emissions were continuously obtained during the whole growing season. Daily and seasonal pattern of methane fluxes from different rice ecosystems were evaluated. Diel pattern of methane emission from irrigated rice fields, in all sites, displayed similar pattern from planting to flowering. Fluxes at 0600, 1200, and 1800 h were important components of the total diel flux. A proposed sampling frequency to accurately estimate methane emission within the growing season was designed based on the magnitude of daily flux variation. Total methane emission from different ecosystems follow the order: deepwater rice > irrigated rice > rainfed rice. Application of pig manure increased total emission by 10 times of that without manure. Green manure application increased emission by 49% of that applied only with inorganic fertilizer. Removal of floodwater at 10 DAP and 35 DAP, within a period of 4 days, inhibited production and emission of methane. The level of variation in daily methane emission and seasonal emission pattern provides useful information for accurate determination of methane fluxes. Characterization of seasonal emission pattern as to ecologies, fertilizer amendments, and water management gives an idea of where to focus mitigation strategies for sustainable rice production.

  12. Enzymatic Oxidation of Methane

    SciTech Connect (OSTI)

    Sirajuddin, S; Rosenzweig, AC

    2015-04-14

    Methane monooxygenases (MMOs) are enzymes that catalyze the oxidation of methane to methanol in methanotrophic bacteria. As potential targets for new gas-to-liquid methane bioconversion processes, MMOs have attracted intense attention in recent years. There are two distinct types of MMO, a soluble, cytoplasmic MMO (sMMO) and a membrane-bound, particulate MMO (pMMO). Both oxidize methane at metal centers within a complex, multisubunit scaffold, but the structures, active sites, and chemical mechanisms are completely different. This Current Topic review article focuses on the overall architectures, active site structures, substrate reactivities, proteinprotein interactions, and chemical mechanisms of both MMOs, with an emphasis on fundamental aspects. In addition, recent advances, including new details of interactions between the sMMO components, characterization of sMMO intermediates, and progress toward understanding the pMMO metal centers are highlighted. The work summarized here provides a guide for those interested in exploiting MMOs for biotechnological applications.

  13. Methane Hydrate Advisory Committee Meeting Minutes | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Methane Hydrate Advisory Committee Meeting Minutes Methane Hydrate Advisory Committee Meeting Minutes Methane Hydrate Advisory Committee Meeting Minutes May 15, 2014 Washington, DC...

  14. Science on the Hill: Methane cloud hunting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Methane cloud hunting Science on the Hill: Methane cloud hunting Los Alamos researchers go ... Science on the Hill: Methane cloud hunting When our team from Los Alamos National ...

  15. Methane Hydrate Program Reports | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Program Reports Methane Hydrate Program Reports PDF icon Secretary of Energy Advisory Board Task Force Report on Methane Hydrate PDF icon FY14 Methane Hydrate Report to Congress ...

  16. Electrochemical methane sensor

    DOE Patents [OSTI]

    Zaromb, S.; Otagawa, T.; Stetter, J.R.

    1984-08-27

    A method and instrument including an electrochemical cell for the detection and measurement of methane in a gas by the oxidation of methane electrochemically at a working electrode in a nonaqueous electrolyte at a voltage about 1.4 volts vs R.H.E. (the reversible hydrogen electrode potential in the same electrolyte), and the measurement of the electrical signal resulting from the electrochemical oxidation.

  17. Subtask 1.22 - Microbial Cycling of CH4, CO2, and N2O in a Wetlands Environment

    SciTech Connect (OSTI)

    Dingyi Ye; Bethany Kurz; Marc Kurz

    2008-12-31

    Soil microbial metabolic activities play an important role in determining CO{sub 2}, CH{sub 4}, and N{sub 2}O fluxes from terrestrial ecosystems. To verify and evaluate CO{sub 2} sequestration potential by wetland restoration in the Prairie Pothole Region (PPR), as well as to address concern over restoration effects on CH{sub 4} and N{sub 2}O emissions, laboratory and in situ microcosm studies on microbial cycling of CO{sub 2}, CH{sub 4}, and N{sub 2}O were initiated. In addition, to evaluate the feasibility of the use of remote sensing to detect soil gas flux from wetlands, a remote-sensing investigation was also conducted. Results of the laboratory microcosm study unequivocally proved that restoration of PPR wetlands does sequester atmospheric CO{sub 2}. Under the experimental conditions, the simulated restored wetlands did not promote neither N{sub 2}O nor CH{sub 4} fluxes. Application of ammonia enhanced both N{sub 2}O and CH{sub 4} emission, indicating that restoration of PPR wetlands may reduce both N{sub 2}O and CH{sub 4} emission by cutting N-fertilizer input. Enhancement of CO{sub 2} emission by the N-fertilizer was observed, and this observation revealed an overlooked fact that application of N-fertilizer may potentially increase CO{sub 2} emission. In addition, the CO{sub 2} results also demonstrate that wetland restoration sequesters atmospheric carbon not only by turning soil conditions from aerobic to anoxic, but also by cutting N-fertilizer input that may enhance CO{sub 2} flux. The investigation on microbial community structure and population dynamics showed that under the experimental conditions restoration of the PPR wetlands would not dramatically increase population sizes of those microorganisms that produce N{sub 2}O and CH{sub 4}. Results of the in situ study proved that restoration of the PPR wetland significantly reduced CO{sub 2} flux. Ammonia enhanced the greenhouse gas emission and linearly correlated to the CO{sub 2} flux within the

  18. Effect of carbon dioxide and nitrogen on the diffusivity of methane confined in nano-porous carbon aerogel

    SciTech Connect (OSTI)

    Mavila Chathoth, Suresh; He, Lilin; Mamontov, Eugene; Melnichenko, Yuri B

    2012-01-01

    The microscopic diffusivity of methane (CH{sub 4}) confined in nano-porous carbon aerogel was investigated as a function of added carbon dioxide (CO{sub 2}) and nitrogen (N{sub 2}) pressure using quasi-elastic neutron scattering (QENS). In the range of the external pressure of 1-2.5 MPa, the self-diffusivity of methane was found to increase with CO{sub 2} pressure and remain practically unchanged in the N{sub 2} environment. Increasing mobility of methane with CO{sub 2} pressure suggests that the adsorbed CH4 molecules become gradually replaced by CO{sub 2} on the surface of carbon aerogel pores, whereas the presence of N{sub 2} does not induce the replacement. The molecular mobility of the methane, with or without added carbon dioxide and nitrogen, is described by the unrestricted diffusion model, which is characteristic of methane compressed in small pores. On the other hand, both nitrogen and carbon dioxide molecules in carbon aerogel, when studied alone, with no methane present, follow a jump diffusion process, characteristic of the molecular mobility in the densified adsorbed layers on the surface of the aerogel pores.

  19. van der Waals forces and confinement in carbon nanopores: Interaction between CH4, COOH, NH3, OH, SH and single-walled carbon nanotubes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Weck, Philippe F.; Kim, Eunja; Wang, Yifeng

    2016-04-13

    Interactions between CH4, COOH, NH3, OH, SH and armchair (n,n)(n=4,7,14) and zigzag (n,0)(n=7,12,25) single-walled carbon nanotubes (SWCNTs) have been systematically investigated within the framework of dispersion-corrected density functional theory (DFT-D2). Endohedral and exohedral molecular adsorption on SWCNT walls is energetically unfavorable or weak, despite the use of C6/r6 pairwise London-dispersion corrections. The effects of pore size and chirality on the molecule/SWCNTs interaction were also assessed. Furthermore, chemisorption of COOH, NH3, OH and SH at SWCNT edge sites was examined using a H-capped (7,0) SWCNT fragment and its impact on electrophilic, nucleophilic and radical attacks was predicted by means of Fukuimore » functions.« less

  20. Carborane-Based Metal-Organic Framework with High Methane and Hydrogen Storage Capacities

    SciTech Connect (OSTI)

    Kennedy, RD; Krungleviciute, V; Clingerman, DJ; Mondloch, JE; Peng, Y; Wilmer, CE; Sarjeant, AA; Snurr, RQ; Hupp, JT; Yildirim, T; Farha, OK; Mirkin, CA

    2013-09-10

    A Cu-carborane-based metal organic framework (MOF), NU-135, which contains a quasi-spherical para-carborane moiety, has been synthesized and characterized. NU-135 exhibits a pore volume of 1.02 cm(3)/g and a gravimetric BET surface area of ca. 2600 m(2)/g, and thus represents the first highly porous carborane-based MOF. As a consequence of the, unique geometry of the carborane unit, NU-135 has a very high volumetric BET surface area of ca. 1900 m(2)/cm(3). CH4, CO2, and H-2 adsorption isotherms were measured over a broad range of pressures and temperatures and are in good agreement with computational predictions. The methane storage capacity of NU-135 at 35 bar and 298 K is ca. 187 v(STP)/v. At 298 K, the pressure required to achieve a methane storage density comparable to that of a compressed natural gas (CNG) tank pressurized to 212 bar, which is a typical storage pressure, is only 65 bar. The methane working capacity (5-65 bar) is 170 v(STP)/v. The volumetric hydrogen storage capacity at 55 bar and 77 K is 49 g/L. These properties are comparable to those of current record holders in the area of methane and hydrogen storage. This initial example lays the groundwork for carborane-based materials with high surface areas.

  1. Conversion of CH4 into H2 at 300 C using Pd/MnO2 catalyst made with an effect of water oxidation

    SciTech Connect (OSTI)

    Koyanaka, Hideki; Takeuchi, K; Kolesnikov, Alexander I

    2014-01-01

    A novel electricity-free deposition of palladium on the surface of manganese dioxide, which has a crystal structure of ramsdellite, was studied. Using the Pd deposition, a nano-particle of Pd/MnO2 was prepared, and it was used for a catalytic performance for reforming methane into hydrogen at 300 C.

  2. The Young Planet-mass Ob ject 2M1207b: A cool, cloudy, and methane...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: The Young Planet-mass Ob ject 2M1207b: A cool, cloudy, and methane-poor atmosphere Citation Details In-Document Search Title: The Young Planet-mass Ob ject ...

  3. Coalbed Methane | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Coalbed Methane Coalbed Methane Coalbed methane is natural gas found in coal deposits. It was once considered a nuisance and mine safety hazard, but today has become a valuable part of the U.S. energy portfolio. A major reason for this is resource characterization and the establishment of efficient recovery methods pioneered by Office of Fossil Energy R&D. Fossil Energy Research Benefits - Coalbed Methane (920.32 KB) More Documents & Publications Before the Senate Energy and Natural

  4. Direct Aromaization of Methane

    SciTech Connect (OSTI)

    George Marcelin

    1997-01-15

    The thermal decomposition of methane offers significant potential as a means of producing higher unsaturated and aromatic hydrocarbons when the extent of reaction is limited. Work in the literature previous to this project had shown that cooling the product and reacting gases as the reaction proceeds would significantly reduce or eliminate the formation of solid carbon or heavier (Clo+) materials. This project studied the effect and optimization of the quenching process as a means of increasing the amount of value added products during the pyrolysis of methane. A reactor was designed to rapidly quench the free-radical combustion reaction so as to maximize the yield of aromatics. The use of free-radical generators and catalysts were studied as a means of lowering the reaction temperature. A lower reaction temperature would have the benefits of more rapid quenching as well as a more feasible commercial process due to savings realized in energy and material of construction costs. It was the goal of the project to identify promising routes from methane to higher hydrocarbons based on the pyrolysis of methane.

  5. Louisiana--North Coalbed Methane Proved Reserves (Billion Cubic...

    U.S. Energy Information Administration (EIA) Indexed Site

    Coalbed Methane Proved Reserves (Billion Cubic Feet) Louisiana--North Coalbed Methane ... Coalbed Methane Proved Reserves as of Dec. 31 North Louisiana Coalbed Methane Proved ...

  6. Methane Hydrates R&D Program

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Methane Hydrate Methane Hydrate Types of Methane Hydrate Deposits Types of Methane Hydrate Deposits Methane hydrate is a cage-like lattice of ice inside of which are trapped molecules of methane, the chief constituent of natural gas. If methane hydrate is either warmed or depressurized, it will revert back to water and natural gas. When brought to the earth's surface, one cubic meter of gas hydrate releases 164 cubic meters of natural gas. Hydrate deposits may be several hundred meters thick and

  7. ISOTOPIC RATIOS IN TITAN's METHANE: MEASUREMENTS AND MODELING

    SciTech Connect (OSTI)

    Nixon, C. A.; Achterberg, R. K.; Temelso, B.; Vinatier, S.; Bezard, B.; Coustenis, A.; Teanby, N. A.; Mandt, K. E.; Sherrill, C. D.; Irwin, P. G. J.; Jennings, D. E.; Romani, P. N.; Flasar, F. M.

    2012-04-20

    The existence of methane in Titan's atmosphere ({approx}6% level at the surface) presents a unique enigma, as photochemical models predict that the current inventory will be entirely depleted by photochemistry in a timescale of {approx}20 Myr. In this paper, we examine the clues available from isotopic ratios ({sup 12}C/{sup 13}C and D/H) in Titan's methane as to the past atmosphere history of this species. We first analyze recent infrared spectra of CH{sub 4} collected by the Cassini Composite Infrared Spectrometer, measuring simultaneously for the first time the abundances of all three detected minor isotopologues: {sup 13}CH{sub 4}, {sup 12}CH{sub 3}D, and {sup 13}CH{sub 3}D. From these we compute estimates of {sup 12}C/{sup 13}C = 86.5 {+-} 8.2 and D/H = (1.59 {+-} 0.33) Multiplication-Sign 10{sup -4}, in agreement with recent results from the Huygens GCMS and Cassini INMS instruments. We also use the transition state theory to estimate the fractionation that occurs in carbon and hydrogen during a critical reaction that plays a key role in the chemical depletion of Titan's methane: CH{sub 4} + C{sub 2}H {yields} CH{sub 3} + C{sub 2}H{sub 2}. Using these new measurements and predictions we proceed to model the time evolution of {sup 12}C/{sup 13}C and D/H in Titan's methane under several prototypical replenishment scenarios. In our Model 1 (no resupply of CH{sub 4}), we find that the present-day {sup 12}C/{sup 13}C implies that the CH{sub 4} entered the atmosphere 60-1600 Myr ago if methane is depleted by chemistry and photolysis alone, but much more recently-most likely less than 10 Myr ago-if hydrodynamic escape is also occurring. On the other hand, if methane has been continuously supplied at the replenishment rate then the isotopic ratios provide no constraints, and likewise for the case where atmospheric methane is increasing. We conclude by discussing how these findings may be combined with other evidence to constrain the overall history of the atmospheric

  8. Methane conversion to methanol

    SciTech Connect (OSTI)

    Noble, R.D.; Falconer, J.L.

    1992-06-01

    The objective of this research study is to demonstrate the effectiveness of a catalytic membrane reactor for the partial oxidation of methane. The specific goals are to demonstrate that we can improve product yield, demonstrate the optimal conditions for membrane reactor operation, determine the transport properties of the membrane, and provide demonstration of the process at the pilot plant scale. The last goal will be performed by Unocal, Inc., our industrial partner, upon successful completion of this study.

  9. Methane conversion to methanol

    SciTech Connect (OSTI)

    Noble, R.D.; Falconer, J.L.

    1992-01-01

    The objective of this research study is to demonstrate the effectiveness of a catalytic membrane reactor for the partial oxidation of methane. The specific goals are to demonstrate that we can improve product yield, demonstrate the optimal conditions for membrane reactor operation, determine the transport properties of the membrane, and provide demonstration of the process at the pilot plant scale. The last goal will be performed by Unocal, Inc., our industrial partner, upon successful completion of this study.

  10. Coal Bed Methane Primer

    SciTech Connect (OSTI)

    Dan Arthur; Bruce Langhus; Jon Seekins

    2005-05-25

    During the second half of the 1990's Coal Bed Methane (CBM) production increased dramatically nationwide to represent a significant new source of income and natural gas for many independent and established producers. Matching these soaring production rates during this period was a heightened public awareness of environmental concerns. These concerns left unexplained and under-addressed have created a significant growth in public involvement generating literally thousands of unfocused project comments for various regional NEPA efforts resulting in the delayed development of public and fee lands. The accelerating interest in CBM development coupled to the growth in public involvement has prompted the conceptualization of this project for the development of a CBM Primer. The Primer is designed to serve as a summary document, which introduces and encapsulates information pertinent to the development of Coal Bed Methane (CBM), including focused discussions of coal deposits, methane as a natural formed gas, split mineral estates, development techniques, operational issues, producing methods, applicable regulatory frameworks, land and resource management, mitigation measures, preparation of project plans, data availability, Indian Trust issues and relevant environmental technologies. An important aspect of gaining access to federal, state, tribal, or fee lands involves education of a broad array of stakeholders, including land and mineral owners, regulators, conservationists, tribal governments, special interest groups, and numerous others that could be impacted by the development of coal bed methane. Perhaps the most crucial aspect of successfully developing CBM resources is stakeholder education. Currently, an inconsistent picture of CBM exists. There is a significant lack of understanding on the parts of nearly all stakeholders, including industry, government, special interest groups, and land owners. It is envisioned the Primer would being used by a variety of

  11. Utilization of fuel cells to beneficially use coal mine methane. Final report

    SciTech Connect (OSTI)

    Brown, J.T.; O`Brien, D.G.; Miller, A.R.; Atkins, R.; Sanders, M.

    1996-03-01

    DOE has been given the responsibility to encourage industry to recover and use methane that is currently being released to the atmosphere. At this time the only method being employed at the Left Fork Mine to remove methane is the mine ventilation system. The methane content was measured at one one-hundredth of a percent. To prevent this methane from being vented to the atmosphere, degasification wells are proposed. To use the coal mine methane, it is proposed to use phosphoric-acid fuel cells to convert methane to electric power. These fuel cells contain (1) a steam reformer to convert the methane to hydrogen (and carbon dioxide), (2) the fuel cell stack, and (3) a power conditioner that provides 200 kW of 60 Hz alternating current output. The environmental impacts and benefits of using this technology ware summarized in the report. The study indicates the methane emission reduction that could be achieved on a national and Global level. The important point being that this technology is economically viable as is demonstrated in the report.

  12. Expression of barley SUSIBA2 transcription factor yields high-starch low-methane rice

    SciTech Connect (OSTI)

    Su, J.; Hu, C.; Yan, X.; Jin, Y.; Chen, Z.; Guan, Q.; Wang, Y.; Zhong, D.; Jansson, Georg C.; Wang, F.; Schnrer, Anna; Sun, Chuanxin

    2015-07-22

    Atmospheric methane is the second most important greenhouse gas after carbon dioxide, and is responsible for about 20% of the global warming effect since pre-industrial times. Rice paddies are the largest anthropogenic methane source and produce 7–17% of atmospheric methane. Warm waterlogged soil and exuded nutrients from rice roots provide ideal conditions for methanogenesis in paddies with annual methane emissions of 25–100-million tonnes. This scenario will be exacerbated by an expansion in rice cultivation needed to meet the escalating demand for food in the coming decades4. There is an urgent need to establish sustainable technologies for increasing rice production while reducing methane fluxes from rice paddies. However, ongoing efforts for methane mitigation in rice paddies are mainly based on farming practices and measures that are difficult to implement5. Despite proposed strategies to increase rice productivity and reduce methane emissions4,6, no high-starch low-methane-emission rice has been developed. Here we show that the addition of a single transcription factor gene, barley SUSIBA2, conferred a shift of carbon flux to SUSIBA2 rice, favouring the allocation of photosynthates to aboveground biomass over allocation to roots. The altered allocation resulted in an increased biomass and starch content in the seeds and stems, and suppressed methanogenesis, possibly through a reduction in root exudates. Three-year field trials in China demonstrated that the cultivation of SUSIBA2 rice was associated with a significant reduction in methane emissions and a decrease in rhizospheric methanogen levels. SUSIBA2 rice offers a sustainable means of providing increased starch content for food production while reducing greenhouse gas emissions from rice cultivation. Approaches to increase rice productivity and reduce methane emissions as seen in SUSIBA2 rice may be particularly beneficial in a future climate with rising temperatures resulting in increased methane

  13. Methyl Chloride from Direct Methane Partial Oxidation: A High-Temperature Shilov-Like Catalytic System

    SciTech Connect (OSTI)

    Yongchun Tang; John Ma

    2012-03-23

    The intention of this study is to demonstrate and evaluate the scientific and economic feasibility of using special solvents to improve the thermal stability of Pt-catalyst in the Shilov system, such that a high reaction temperature could be achieved. The higher conversion rate (near 100%) of methyl chloride from partial oxidation of methane under the high temperature ({approx} 200 C) without significant Pt0 precipitation has been achieved. High concentration of the Cl- ion has been identified as the key for the stabilization of the Pt-catalysts. H/D exchange measurements indicated that the over oxidation will occur at the elevated temperature, developments of the effective product separation processes will be necessary in order to rationalize the industry-visible CH4 to CH3Cl conversion.

  14. Methane/nitrogen separation process

    DOE Patents [OSTI]

    Baker, Richard W.; Lokhandwala, Kaaeid A.; Pinnau, Ingo; Segelke, Scott

    1997-01-01

    A membrane separation process for treating a gas stream containing methane and nitrogen, for example, natural gas. The separation process works by preferentially permeating methane and rejecting nitrogen. We have found that the process is able to meet natural gas pipeline specifications for nitrogen, with acceptably small methane loss, so long as the membrane can exhibit a methane/nitrogen selectivity of about 4, 5 or more. This selectivity can be achieved with some rubbery and super-glassy membranes at low temperatures. The process can also be used for separating ethylene from nitrogen.

  15. Methane/nitrogen separation process

    DOE Patents [OSTI]

    Baker, R.W.; Lokhandwala, K.A.; Pinnau, I.; Segelke, S.

    1997-09-23

    A membrane separation process is described for treating a gas stream containing methane and nitrogen, for example, natural gas. The separation process works by preferentially permeating methane and rejecting nitrogen. The authors have found that the process is able to meet natural gas pipeline specifications for nitrogen, with acceptably small methane loss, so long as the membrane can exhibit a methane/nitrogen selectivity of about 4, 5 or more. This selectivity can be achieved with some rubbery and super-glassy membranes at low temperatures. The process can also be used for separating ethylene from nitrogen. 11 figs.

  16. North America's net terrestrial CO2 exchange with the atmosphere...

    Office of Scientific and Technical Information (OSTI)

    a synthesis of net land-atmosphere CO2 exchange for North America (Canada, United States, and Mexico) over the period 1990-2009. Only CO2 is considered, not methane or...

  17. Methane Hydrate Advisory Committee Meeting Minutes | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    2012 Houston, TX PDF icon July 26, 2012 Meeting Minutes More Documents & Publications Methane Hydrate Advisory Committee Meeting Minutes Methane Hydrate Advisory Committee Meeting...

  18. Methane Hydrate Advisory Committee Meeting Minutes | Department...

    Office of Environmental Management (EM)

    Washington, DC PDF icon July 16, 2013 Meeting Minutes More Documents & Publications Methane Hydrate Advisory Committee Meeting Minutes Methane Hydrate Advisory Committee Meeting...

  19. Methane Hydrate Advisory Committee Meeting Minutes | Department...

    Energy Savers [EERE]

    DC PDF icon March 27-28, 2014, Meeting Minutes More Documents & Publications Methane Hydrate Advisory Committee Meeting Minutes, March 2010 Methane Hydrate Advisory...

  20. Methane Power Inc | Open Energy Information

    Open Energy Info (EERE)

    Power Inc Jump to: navigation, search Logo: Methane Power Inc. Name: Methane Power Inc. Address: 121 Edinburgh South Drive Place: Cary, NC Zip: 27511 Sector: Renewable Energy...

  1. Methane Hydrate Advisory Committee Meeting Minutes | Department...

    Broader source: Energy.gov (indexed) [DOE]

    June 6th - 7th, 2013 Meeting Minutes More Documents & Publications Methane Hydrate Advisory Committee Meeting Minutes, June 6th-7th, 2013 Methane Hydrate Advisory Committee Meeting...

  2. LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL

    SciTech Connect (OSTI)

    Don Augenstein; Ramin Yazdani; Rick Moore; Michelle Byars; Jeff Kieffer; Professor Morton Barlaz; Rinav Mehta

    2000-02-26

    Controlled landfilling is an approach to manage solid waste landfills, so as to rapidly complete methane generation, while maximizing gas capture and minimizing the usual emissions of methane to the atmosphere. With controlled landfilling, methane generation is accelerated to more rapid and earlier completion to full potential by improving conditions (principally moisture, but also temperature) to optimize biological processes occurring within the landfill. Gas is contained through use of surface membrane cover. Gas is captured via porous layers, under the cover, operated at slight vacuum. A field demonstration project has been ongoing under NETL sponsorship for the past several years near Davis, CA. Results have been extremely encouraging. Two major benefits of the technology are reduction of landfill methane emissions to minuscule levels, and the recovery of greater amounts of landfill methane energy in much shorter times, more predictably, than with conventional landfill practice. With the large amount of US landfill methane generated, and greenhouse potency of methane, better landfill methane control can play a substantial role both in reduction of US greenhouse gas emissions and in US renewable energy. The work described in this report, to demonstrate and advance this technology, has used two demonstration-scale cells of size (8000 metric tons [tonnes]), sufficient to replicate many heat and compaction characteristics of larger ''full-scale'' landfills. An enhanced demonstration cell has received moisture supplementation to field capacity. This is the maximum moisture waste can hold while still limiting liquid drainage rate to minimal and safely manageable levels. The enhanced landfill module was compared to a parallel control landfill module receiving no moisture additions. Gas recovery has continued for a period of over 4 years. It is quite encouraging that the enhanced cell methane recovery has been close to 10-fold that experienced with conventional

  3. Atmospheric Chemistry

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    chemistry Atmospheric Chemistry Atmospheric Chemistry is the study of the composition of the atmosphere, the sources and fates of gases and particles in air, and changes induced by ...

  4. Coal mine methane global review

    SciTech Connect (OSTI)

    2008-07-01

    This is the second edition of the Coal Mine Methane Global Overview, updated in the summer of 2008. This document contains individual, comprehensive profiles that characterize the coal and coal mine methane sectors of 33 countries - 22 methane to market partners and an additional 11 coal-producing nations. The executive summary provides summary tables that include statistics on coal reserves, coal production, methane emissions, and CMM projects activity. An International Coal Mine Methane Projects Database accompanies this overview. It contains more detailed and comprehensive information on over two hundred CMM recovery and utilization projects around the world. Project information in the database is updated regularly. This document will be updated annually. Suggestions for updates and revisions can be submitted to the Administrative Support Group and will be incorporate into the document as appropriate.

  5. Production of methane by anaerobic fermentation of waste materials

    SciTech Connect (OSTI)

    Hitzman, D.O.

    1989-01-17

    This patent describes an apparatus for producing methane by anaerobic fermentation of waste material, comprising: cavity means in the earth for holding a quantity of the waste material; means for covering a quantity of the waste material in the cavity means and thereby separating the quantity of the waste material from the atmosphere; first conduit means communicating between the waste material in the cavity means and a location remote from the cavity means for conveying gas comprising carbon dioxide and methane from the cavity means to the location; gas separation means communicating with the first conduit means at the location for separating carbon dioxide from methane, the first conduit means including at least one pipe having a plurality of apertures therein and disposed in the cavity means extending into and in fluid flow communication with the waste material for receiving gas liberated by the anaerobic fermentation of the waste material and comprising carbon dioxide and methane, through the apertures therein for conveyance via the first conduit means to the gas separation means; second conduit means communicating between the gas separation means and the waste material in the cavity means for conveying carbon dioxide from the gas separation means to the waste material; and third conduit means communicating with the gas separation means for conveying methane from the gas separation means.

  6. Top-down estimate of methane emissions in California using a mesoscale inverse modeling technique: The South Coast Air Basin

    SciTech Connect (OSTI)

    Cui, Yu Yan; Brioude, Jerome; McKeen, Stuart A.; Angevine, Wayne M.; Kim, Si -Wan; Frost, Gregory J.; Ahmadov, Ravan; Peischl, Jeff; Bousserez, Nicolas; Liu, Zhen; Ryerson, Thomas B.; Wofsy, Steve C.; Santoni, Gregory W.; Kort, Eric A.; Fischer, Marc L.; Trainer, Michael

    2015-07-28

    Methane (CH4) is the primary component of natural gas and has a larger global warming potential than CO2. Some recent top-down studies based on observations showed CH4 emissions in California's South Coast Air Basin (SoCAB) were greater than those expected from population-apportioned bottom-up state inventories. In this study, we quantify CH4 emissions with an advanced mesoscale inverse modeling system at a resolution of 8 km 8 km, using aircraft measurements in the SoCAB during the 2010 Nexus of Air Quality and Climate Change campaign to constrain the inversion. To simulate atmospheric transport, we use the FLEXible PARTicle-Weather Research and Forecasting (FLEXPART-WRF) Lagrangian particle dispersion model driven by three configurations of the Weather Research and Forecasting (WRF) mesoscale model. We determine surface fluxes of CH4 using a Bayesian least squares method in a four-dimensional inversion. Simulated CH4 concentrations with the posterior emission inventory achieve much better correlations with the measurements (R2 = 0.7) than using the prior inventory (U.S. Environmental Protection Agency's National Emission Inventory 2005, R2 = 0.5). The emission estimates for CH4 in the posterior, 46.3 9.2 Mg CH4/h, are consistent with published observation-based estimates. Changes in the spatial distribution of CH4 emissions in the SoCAB between the prior and posterior inventories are discussed. Missing or underestimated emissions from dairies, the oil/gas system, and landfills in the SoCAB seem to explain the differences between the prior and posterior inventories. Furthermore, we estimate that dairies contributed 5.9 1.7 Mg CH4/h and the two sectors of oil and gas industries (production and downstream) and landfills together contributed 39.6 8.1 Mg CH4/h in the SoCAB.

  7. Top-down estimate of methane emissions in California using a mesoscale inverse modeling technique: The South Coast Air Basin

    SciTech Connect (OSTI)

    Cui, Yu Yan; Brioude, Jerome; McKeen, Stuart A.; Angevine, Wayne M.; Kim, Si -Wan; Frost, Gregory J.; Ahmadov, Ravan; Peischl, Jeff; Bousserez, Nicolas; Liu, Zhen; Ryerson, Thomas B.; Wofsy, Steve C.; Santoni, Gregory W.; Kort, Eric A.; Fischer, Marc L.; Trainer, Michael

    2015-07-28

    Methane (CH4) is the primary component of natural gas and has a larger global warming potential than CO2. Some recent top-down studies based on observations showed CH4 emissions in California's South Coast Air Basin (SoCAB) were greater than those expected from population-apportioned bottom-up state inventories. In this study, we quantify CH4 emissions with an advanced mesoscale inverse modeling system at a resolution of 8 km × 8 km, using aircraft measurements in the SoCAB during the 2010 Nexus of Air Quality and Climate Change campaign to constrain the inversion. To simulate atmospheric transport, we use the FLEXible PARTicle-Weather Research and Forecasting (FLEXPART-WRF) Lagrangian particle dispersion model driven by three configurations of the Weather Research and Forecasting (WRF) mesoscale model. We determine surface fluxes of CH4 using a Bayesian least squares method in a four-dimensional inversion. Simulated CH4 concentrations with the posterior emission inventory achieve much better correlations with the measurements (R2 = 0.7) than using the prior inventory (U.S. Environmental Protection Agency's National Emission Inventory 2005, R2 = 0.5). The emission estimates for CH4 in the posterior, 46.3 ± 9.2 Mg CH4/h, are consistent with published observation-based estimates. Changes in the spatial distribution of CH4 emissions in the SoCAB between the prior and posterior inventories are discussed. Missing or underestimated emissions from dairies, the oil/gas system, and landfills in the SoCAB seem to explain the differences between the prior and posterior inventories. Furthermore, we estimate that dairies contributed 5.9 ± 1.7 Mg CH4/h and the two sectors of oil and gas industries (production and downstream) and landfills together contributed 39.6 ± 8.1 Mg CH4/h in the SoCAB.

  8. New Metabolic Pathway Discovered in Methane-Consuming Bacteria...

    Office of Science (SC) Website

    To better understand microbial CH4 utilization, researchers used a multifaceted systems biology approach to examine Methylomicrobium alcaliphilum, a methanotroph (i.e., an aerobic ...

  9. 7.4 Landfill Methane Utilization

    Office of Energy Efficiency and Renewable Energy (EERE)

    A chapter on Landfill Methane Utilization from the Clean Energy Strategies for Local Governments publication.

  10. Coalbed Methane Production

    Gasoline and Diesel Fuel Update (EIA)

    Methane Production (Billion Cubic Feet) Period: Annual Download Series History Download Series History Definitions, Sources & Notes Definitions, Sources & Notes 2009 2010 2011 2012 2013 2014 View History U.S. 1,914 1,886 1,763 1,655 1,466 1,404 1989-2014 Alabama 105 102 98 91 62 78 1989-2014 Alaska 0 0 0 0 0 0 2005-2014 Arkansas 3 3 4 2 2 2 2005-2014 California 0 0 0 0 0 0 2005-2014 Colorado 498 533 516 486 444 412 1989-2014 Florida 0 0 0 0 0 0 2005-2014 Kansas 43 41 37 34 30 27

  11. Methane Stakeholder Roundtables | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Methane Stakeholder Roundtables Methane Stakeholder Roundtables April 24, 2014 - 3:00pm Addthis Methane Stakeholder Roundtables Advancing the Interagency Methane Strategy As directed by President Obama in his Climate Action Plan, the Department of Energy (DOE) collaborated with other Federal agencies to develop a Strategy to Reduce Methane Emissions, which was formally announced by the White House last month. To advance this strategy, DOE is now working with other Federal agencies and the White

  12. methane hydrates | netl.doe.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    methane hydrates methane-hydrates.jpg Maintaining a focused vision on what's next is one trait that makes NETL a lab of the future, and methane hydrates are one "cool" part of that vision. Found in Arctic and deep-water marine environments, methane hydrates are an untapped abundant source of natural gas. A hydrate comprises a crystal structure in which frozen water creates a cage that traps molecules of primarily methane (natural gas). NETL researchers are exploring and developing

  13. Assessment of the methane oxidation capacity of compacted soils intended for use as landfill cover materials

    SciTech Connect (OSTI)

    Rachor, Ingke; Gebert, Julia; Groengroeft, Alexander; Pfeiffer, Eva-Maria

    2011-05-15

    and diffusive ingress of atmospheric air. For one material with elevated levels of fine particles and high organic matter content, methane production impeded the quantification of methane oxidation potentials. Regarding the design of landfill cover layers it was concluded that the magnitude of the expected methane load, the texture and expected compaction of the cover material are key variables that need to be known. Based on these, a column study can serve as an appropriate testing system to determine the methane oxidation capacity of a soil intended as landfill cover material.

  14. Methane emissions from MBT landfills

    SciTech Connect (OSTI)

    Heyer, K.-U. Hupe, K.; Stegmann, R.

    2013-09-15

    Highlights: • Compilation of methane generation potential of mechanical biological treated (MBT) municipal solid waste. • Impacts and kinetics of landfill gas production of MBT landfills, approach with differentiated half-lives. • Methane oxidation in the waste itself and in soil covers. • Estimation of methane emissions from MBT landfills in Germany. - Abstract: Within the scope of an investigation for the German Federal Environment Agency (“Umweltbundesamt”), the basics for the estimation of the methane emissions from the landfilling of mechanically and biologically treated waste (MBT) were developed. For this purpose, topical research including monitoring results regarding the gas balance at MBT landfills was evaluated. For waste treated to the required German standards, a methane formation potential of approximately 18–24 m{sup 3} CH{sub 4}/t of total dry solids may be expected. Monitoring results from MBT landfills show that a three-phase model with differentiated half-lives describes the degradation kinetics in the best way. This is due to the fact that during the first years of disposal, the anaerobic degradation processes still proceed relatively intensively. In addition in the long term (decades), a residual gas production at a low level is still to be expected. Most of the soils used in recultivation layer systems at German landfills show a relatively high methane oxidation capacity up to 5 l CH{sub 4}/(m{sup 2} h). However, measurements at MBT disposal sites indicate that the majority of the landfill gas (in particular at non-covered areas), leaves the landfill body via preferred gas emission zones (hot spots) without significant methane oxidation. Therefore, rather low methane oxidation factors are recommended for open and temporarily covered MBT landfills. Higher methane oxidation rates can be achieved when the soil/recultivation layer is adequately designed and operated. Based on the elaborated default values, the First Order Decay (FOD

  15. Methane Hydrate Advisory Committee Charter | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Charter Methane Hydrate Advisory Committee Charter Methane Hydrate Advisory Committee Charter PDF icon Methane Hydrate Advisory Committee Charter More Documents & Publications ...

  16. May 15, 2014 Methane Hydrates Committee Meeting Agenda | Department...

    Office of Environmental Management (EM)

    May 15, 2014 Methane Hydrates Committee Meeting Agenda May 15, 2014 Methane Hydrates Committee Meeting Agenda May 15, 2014 Methane Hydrates Committee Meeting Agenda PDF icon...

  17. Methane Hydrate Advisory Committee Meeting Minutes, March 2010...

    Energy Savers [EERE]

    March 2010 Methane Hydrate Advisory Committee Meeting Minutes, March 2010 Methane Hydrate Advisory Committee Meeting Minutes March 2010 Washington, DC PDF icon Methane Hydrate...

  18. Methane Hydrate Advisory Committee Meeting Minutes, January 2010...

    Broader source: Energy.gov (indexed) [DOE]

    0 Atlanta, GA Methane Hydrate Advisory Committee Meeting Minutes, January 2010 More Documents & Publications Methane Hydrate Advisory Committee Meeting Minutes, March 2010 Methane...

  19. Methane Hydrate Advisory Committee Meeting Minutes, June 6th...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Methane Hydrate Advisory Committee Meeting Minutes, June 6th-7th, 2013 Methane Hydrate Advisory Committee Meeting Minutes, June 6th-7th, 2013 Methane Hydrate Advisory Committee...

  20. China United Coalbed Methane Co Ltd | Open Energy Information

    Open Energy Info (EERE)

    Coalbed Methane Co Ltd Jump to: navigation, search Name: China United Coalbed Methane Co Ltd Place: Beijing Municipality, China Zip: 100011 Product: Coal bed methane developer in...

  1. Metro Methane Recovery Facility Biomass Facility | Open Energy...

    Open Energy Info (EERE)

    Methane Recovery Facility Biomass Facility Jump to: navigation, search Name Metro Methane Recovery Facility Biomass Facility Facility Metro Methane Recovery Facility Sector Biomass...

  2. New Mexico Coalbed Methane Production (Billion Cubic Feet)

    Gasoline and Diesel Fuel Update (EIA)

    Production (Billion Cubic Feet) New Mexico Coalbed Methane Production (Billion Cubic Feet) ... Referring Pages: Coalbed Methane Estimated Production New Mexico Coalbed Methane Proved ...

  3. New Mexico Coalbed Methane Proved Reserves (Billion Cubic Feet...

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    Proved Reserves (Billion Cubic Feet) New Mexico Coalbed Methane Proved Reserves (Billion ... Coalbed Methane Proved Reserves as of Dec. 31 New Mexico Coalbed Methane Proved Reserves, ...

  4. North Dakota Coalbed Methane Proved Reserves (Billion Cubic Feet...

    U.S. Energy Information Administration (EIA) Indexed Site

    North Dakota Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade Year-0 Year-1 ... Coalbed Methane Proved Reserves as of Dec. 31 North Dakota Coalbed Methane Proved ...

  5. Methane Hydrate Research and Development Act of 2000 | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Research and Development Act of 2000 Methane Hydrate Research and Development Act of 2000 Methane Hydrate Research and Development Act of 2000 PDF icon Methane Hydrate Research and ...

  6. Methane generation from animal wastes

    SciTech Connect (OSTI)

    Fulton, E.L.

    1980-06-01

    The conversion of manure to biogas via anaerobic digestion is described. The effluent resulting from the conversion retains fertilizer value and is environmentally acceptable. Discussion is presented under the headings: methane formation in the digester; the Tarleton State Poultry Waste to Methane production system; operating experience at Tarleton State; economics of biogas production from poultry waste; construction cost and biogas value; energy uses; feed and waste processing; and advantages of anaerobic digestion. (DMC)

  7. A model of the methane cycle, permafrost, and hydrology of the Siberian continental margin

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Archer, D.

    2014-06-03

    A two-dimensional model of a passive continental margin was adapted to the simulation of the methane cycle on Siberian continental shelf and slope, attempting to account for the impacts of glacial/interglacial cycles in sea level, alternately exposing the continental shelf to freezing conditions with deep permafrost formation during glacial times, and immersion in the ocean in interglacial times. The model is used to gauge the impact of the glacial cycles, and potential anthropogenic warming in the deep future, on the atmospheric methane emission flux, and the sensitivities of that flux to processes such as permafrost formation and terrestrial organic carbonmore » (Yedoma) deposition. Hydrological forcing drives a freshening and ventilation of pore waters in areas exposed to the atmosphere, which is not quickly reversed by invasion of seawater upon submergence, since there is no analogous saltwater pump. This hydrological pump changes the salinity enough to affect the stability of permafrost and methane hydrates on the shelf. Permafrost formation inhibits bubble transport through the sediment column, by construction in the model. The impact of permafrost on the methane budget is to replace the bubble flux by offshore groundwater flow containing dissolved methane, rather than accumulating methane for catastrophic release when the permafrost seal fails during warming. By far the largest impact of the glacial/interglacial cycles on the atmospheric methane flux is attenuation by dissolution of bubbles in the ocean when sea level is high. Methane emissions are highest during the regression (soil freezing) part of the cycle, rather than during transgression (thawing). The model-predicted methane flux to the atmosphere in response to a warming climate is small, relative to the global methane production rate, because of the ongoing flooding of the continental shelf. A slight increase due to warming could be completely counteracted by sea level rise on geologic time

  8. METHANE GAS STABILIZES SUPERCOOLED ETHANE DROPLETS IN TITAN'S CLOUDS

    SciTech Connect (OSTI)

    Wang, Chia C.; Lang, E. Kathrin; Signorell, Ruth

    2010-03-20

    Strong evidence for ethane clouds in various regions of Titan's atmosphere has recently been found. Ethane is usually assumed to exist as ice particles in these clouds, although the possible role of liquid and supercooled liquid ethane droplets has been recognized. Here, we report on infrared spectroscopic measurements of ethane aerosols performed in the laboratory under conditions mimicking Titan's lower atmosphere. The results clearly show that liquid ethane droplets are significantly stabilized by methane gas which is ubiquitous in Titan's nitrogen atmosphere-a phenomenon that does not have a counterpart for water droplets in Earth's atmosphere. Our data imply that supercooled ethane droplets are much more abundant in Titan's clouds than previously anticipated. Possibly, these liquid droplets are even more important for cloud processes and the formation of lakes than ethane ice particles.

  9. Enhanced Dry Reforming of Methane on Ni and Ni-Pt Catalysts Synthesized by Atomic Layer Deposition

    SciTech Connect (OSTI)

    Gould, Troy D.; Montemore, Matthew M.; Lubers, Alia M.; Ellis, Lucas D.; Weimer, Alan; Falconer, John L.; Medlin, James W.

    2015-02-25

    Atomic layer deposition (ALD) was used to deposit Ni and Pt on alumina supports to form monometallic and bimetallic catalysts with initial particle sizes of 12.4 nm. The ALD catalysts were more active (per mass of metal) than catalysts prepared by incipient wetness (IW) for dry reforming of methane (DRM), and they did not form carbon whiskers during reaction due to their sufficiently small size. Catalysts modified by Pt ALD had higher rates of reaction per mass of metal and inhibited coking, whereas NiPt catalysts synthesized by IW still formed carbon whiskers. Temperature-programmed reduction of Ni catalysts modified by Pt ALD indicated the presence of bimetallic interaction. Density functional theory calculations suggested that under reaction conditions, the NiPt surfaces form Ni-terminated surfaces that are associated with higher DRM rates (due to their C and O adsorption energies, as well as the CO formation and CH4 dissociation energies).

  10. Methane Hydrate Annual Reports | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Annual Reports Methane Hydrate Annual Reports Section 968 of the Energy Policy Act of 2005 requires the Department of Energy to submit to Congress an annual report on the results of Methane Hydrate research. Listed are the Annual Reports per Fiscal Year. FY 14 Methane Hydrate Program Report to Congress (10.92 MB) FY 13 Methane Hydrates Annual Report to Congress (960.13 KB) FY 12 Methane Hydrates Annual Report to Congress (1.09 MB) FY 11 Methane Hydrates Annual Report to Congress (953.09 KB) FY

  11. Methane Hydrate Reservoir Simulator Code Comparison Study

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Annual Reports Methane Hydrate Annual Reports Section 968 of the Energy Policy Act of 2005 requires the Department of Energy to submit to Congress an annual report on the results of Methane Hydrate research. Listed are the Annual Reports per Fiscal Year. FY 14 Methane Hydrate Program Report to Congress (10.92 MB) FY 13 Methane Hydrates Annual Report to Congress (960.13 KB) FY 12 Methane Hydrates Annual Report to Congress (1.09 MB) FY 11 Methane Hydrates Annual Report to Congress (953.09 KB) FY

  12. Release of Methane from Bering Sea Sediments During the Last Glacial Period

    SciTech Connect (OSTI)

    Mea Cook; Lloyd Keigwin

    2007-11-30

    Several lines of evidence suggest that during times of elevated methane flux the sulfate-methane transition zone (SMTZ) was positioned near the sediment-water interface. We studied two cores (from 700 m and 1457 m water depth) from the Umnak Plateau region. Anomalously low d13C and high d18O in benthic and planktonic foraminifera in these cores are the consequence of diagenetic overgrowths of authigenic carbonates. There are multiple layers of authigenic-carbonate-rich sediment in these cores, and the stable isotope compositions of the carbonates are consistent with those formed during anaerobic oxidation of methane (AOM). The carbonate-rich layers are associated with biomarkers produced by methane-oxidizing archaea, archaeol and glyceryl dibiphytanyl glyceryl tetraether (GDGT). The d13C of the archaeol and certain GDGTs are isotopically depleted. These carbonate- and AOM-biomarker-rich layers were emplaced in the SMTZ during episodes when there was a high flux of methane or methane-rich fluids upward in the sediment column. The sediment methane in the Umnak Plateau region appears to have been very dynamic during the glacial period, and interacted with the ocean-atmosphere system at millennial time scales. The upper-most carbonate-rich layers are in radiocarbon-dated sediment deposited during interstitials 2 and 3, 28-20 ka, and may be associated with the climate warming during this time.

  13. Patterns in wetland microbial community composition and functional gene repertoire associated with methane emissions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    He, Shaomei; Malfatti, Stephanie A.; McFarland, Jack W.; Anderson, Frank E.; Pati, Amrita; Huntemann, Marcel; Tremblay, Julien; Glavina del Rio, Tijana; Waldrop, Mark P.; Windham-Myers, Lisamarie; et al

    2015-05-19

    Wetland restoration on peat islands previously drained for agriculture has potential to reverse land subsidence and sequester atmospheric carbon dioxide as peat accretes. However, the emission of methane could potentially offset the greenhouse gas benefits of captured carbon. As microbial communities play a key role in governing wetland greenhouse gas fluxes, we are interested in how microbial community composition and functions are associated with wetland hydrology, biogeochemistry, and methane emission, which is critical to modeling the microbial component in wetland methane fluxes and to managing restoration projects for maximal carbon sequestration. Here, we couple sequence-based methods with biogeochemical and greenhousemore » gas measurements to interrogate microbial communities from a pilot-scale restored wetland in the Sacramento-San Joaquin Delta of California, revealing considerable spatial heterogeneity even within this relatively small site. A number of microbial populations and functions showed strong correlations with electron acceptor availability and methane production; some also showed a preference for association with plant roots. Marker gene phylogenies revealed a diversity of major methane-producing and -consuming populations and suggested novel diversity within methanotrophs. Methanogenic archaea were observed in all samples, as were nitrate-, sulfate-, and metal-reducing bacteria, indicating that no single terminal electron acceptor was preferred despite differences in energetic favorability and suggesting spatial microheterogeneity and microniches. Notably, methanogens were negatively correlated with nitrate-, sulfate-, and metal-reducing bacteria and were most abundant at sampling sites with high peat accretion and low electron acceptor availability, where methane production was highest. Wetlands are the largest nonanthropogenic source of atmospheric methane but also a key global carbon reservoir. Characterizing belowground microbial

  14. Patterns in wetland microbial community composition and functional gene repertoire associated with methane emissions

    SciTech Connect (OSTI)

    He, Shaomei; Malfatti, Stephanie A.; McFarland, Jack W.; Anderson, Frank E.; Pati, Amrita; Huntemann, Marcel; Tremblay, Julien; Glavina del Rio, Tijana; Waldrop, Mark P.; Windham-Myers, Lisamarie; Tringe, Susannah G.

    2015-05-19

    Wetland restoration on peat islands previously drained for agriculture has potential to reverse land subsidence and sequester atmospheric carbon dioxide as peat accretes. However, the emission of methane could potentially offset the greenhouse gas benefits of captured carbon. As microbial communities play a key role in governing wetland greenhouse gas fluxes, we are interested in how microbial community composition and functions are associated with wetland hydrology, biogeochemistry, and methane emission, which is critical to modeling the microbial component in wetland methane fluxes and to managing restoration projects for maximal carbon sequestration. Here, we couple sequence-based methods with biogeochemical and greenhouse gas measurements to interrogate microbial communities from a pilot-scale restored wetland in the Sacramento-San Joaquin Delta of California, revealing considerable spatial heterogeneity even within this relatively small site. A number of microbial populations and functions showed strong correlations with electron acceptor availability and methane production; some also showed a preference for association with plant roots. Marker gene phylogenies revealed a diversity of major methane-producing and -consuming populations and suggested novel diversity within methanotrophs. Methanogenic archaea were observed in all samples, as were nitrate-, sulfate-, and metal-reducing bacteria, indicating that no single terminal electron acceptor was preferred despite differences in energetic favorability and suggesting spatial microheterogeneity and microniches. Notably, methanogens were negatively correlated with nitrate-, sulfate-, and metal-reducing bacteria and were most abundant at sampling sites with high peat accretion and low electron acceptor availability, where methane production was highest. Wetlands are the largest nonanthropogenic source of atmospheric methane but also a key global carbon reservoir. Characterizing belowground microbial communities

  15. METHANE HYDRATE ADVISORY COMMITTEE U.S. Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    METHANE HYDRATE ADVISORY COMMITTEE U.S. Department of Energy Advisory Committee Charter - - - - ---- ---- ------ 1. Committee's Official Designation. Methane Hydrate Advisory...

  16. Activation of methane by transition metal-substituted aluminophosphate molecular sieves

    DOE Patents [OSTI]

    Iton, Lennox E.; Maroni, Victor A.

    1991-01-01

    Aluminophosphate molecular sieves substituted with cobalt, manganese or iron and having the AlPO.sub.4 -34 or AlPO.sub.4 -5, or related AlPO.sub.4 structure activate methane starting at approximately 350.degree. C. Between 400.degree. and 500.degree. C. and at methane pressures .ltoreq.1 atmosphere the rate of methane conversion increases steadily with typical conversion efficiencies at 500.degree. C. approaching 50% and selectivity to the production of C.sub.2+ hydrocarbons approaching 100%. The activation mechanism is based on reduction of the transition metal(III) form of the molecular sieve to the transition metal(II) form with accompanying oxidative dehydrogenation of the methane. Reoxidation of the - transition metal(II) form to the transition metal(III) form can be done either chemically (e.g., using O.sub.2) or electrochemically.

  17. File:Methane.pdf | Open Energy Information

    Open Energy Info (EERE)

    Methane.pdf Jump to: navigation, search File File history File usage File:Methane.pdf Size of this preview: 448 600 pixels. Go to page 1 2 3 4 5 Go next page next page ...

  18. Miscellaneous States Coalbed Methane Proved Reserves (Billion...

    U.S. Energy Information Administration (EIA) Indexed Site

    Coalbed Methane Proved Reserves (Billion Cubic Feet) Miscellaneous States Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 ...

  19. Methane Gas Conversion Property Tax Exemption

    Broader source: Energy.gov [DOE]

    Under Iowa's methane gas conversion property tax exemption, real and personal property used to decompose waste and convert the waste to gas, collect the methane or other gases, convert the gas to...

  20. Method for the photocatalytic conversion of methane

    DOE Patents [OSTI]

    Noceti, R.P.; Taylor, C.E.; D`Este, J.R.

    1998-02-24

    A method for converting methane to methanol is provided comprising subjecting the methane to visible light in the presence of a catalyst and an electron transfer agent. Another embodiment of the invention provides for a method for reacting methane and water to produce methanol and hydrogen comprising preparing a fluid containing methane, an electron transfer agent and a photolysis catalyst, and subjecting said fluid to visible light for an effective period of time. 3 figs.

  1. Methane Hydrate Production Feasibility | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Production Feasibility Methane Hydrate Production Feasibility The red curves are temperature profiles for various water depths; the blue line shows methane hydrate stability relative to temperature and pressure. The area enclosed by the two curves represents the area of methane hydrate stability. The red curves are temperature profiles for various water depths; the blue line shows methane hydrate stability relative to temperature and pressure. The area enclosed by the two curves represents the

  2. Method for the photocatalytic conversion of methane

    DOE Patents [OSTI]

    Noceti, Richard P.; Taylor, Charles E.; D'Este, Joseph R.

    1998-01-01

    A method for converting methane to methanol is provided comprising subjecting the methane to visible light in the presence of a catalyst and an electron transfer agent. Another embodiment of the invention provides for a method for reacting methane and water to produce methanol and hydrogen comprising preparing a fluid containing methane, an electron transfer agent and a photolysis catalyst, and subjecting said fluid to visible light for an effective period of time.

  3. Reducing Open Cell Landfill Methane Emissions with a Bioactive Alternative Daily

    SciTech Connect (OSTI)

    Helene Hilger; James Oliver; Jean Bogner; David Jones

    2009-03-31

    Methane and carbon dioxide are formed in landfills as wastes degrade. Molecule-for-molecule, methane is about 20 times more potent than carbon dioxide at trapping heat in the earth's atmosphere, and thus, it is the methane emissions from landfills that are scrutinized. For example, if emissions composed of 60% methane and 40% carbon dioxide were changed to a mix that was 40% methane and 60% carbon dioxide, a 30% reduction in the landfill's global warming potential would result. A 10% methane, 90% carbon dioxide ratio will result in a 75% reduction in global warming potential compared to the baseline. Gas collection from a closed landfill can reduce emissions, and it is sometimes combined with a biocover, an engineered system where methane oxidizing bacteria living in a medium such as compost, convert landfill methane to carbon dioxide and water. Although methane oxidizing bacteria merely convert one greenhouse gas (methane) to another (carbon dioxide), this conversion can offer significant reductions in the overall greenhouse gas contribution, or global warming potential, associated with the landfill. What has not been addressed to date is the fact that methane can also escape from a landfill when the active cell is being filled with waste. Federal regulations require that newly deposited solid waste to be covered daily with a 6 in layer of soil or an alternative daily cover (ADC), such as a canvas tarp. The aim of this study was to assess the feasibility of immobilizing methane oxidizing bacteria into a tarp-like matrix that could be used for alternative daily cover at open landfill cells to prevent methane emissions. A unique method of isolating methanotrophs from landfill cover soil was used to create a liquid culture of mixed methanotrophs. A variety of prospective immobilization techniques were used to affix the bacteria in a tarp-like matrix. Both gel encapsulation of methanotrophs and gels with liquid cores containing methanotrophs were readily made but

  4. Methane generation from waste materials

    SciTech Connect (OSTI)

    Samani, Zohrab A.; Hanson, Adrian T.; Macias-Corral, Maritza

    2010-03-23

    An organic solid waste digester for producing methane from solid waste, the digester comprising a reactor vessel for holding solid waste, a sprinkler system for distributing water, bacteria, and nutrients over and through the solid waste, and a drainage system for capturing leachate that is then recirculated through the sprinkler system.

  5. Methane production by attached film

    DOE Patents [OSTI]

    Jewell, William J.

    1981-01-01

    A method for purifying wastewater of biodegradable organics by converting the organics to methane and carbon dioxide gases is disclosed, characterized by the use of an anaerobic attached film expanded bed reactor for the reaction process. Dilute organic waste material is initially seeded with a heterogeneous anaerobic bacteria population including a methane-producing bacteria. The seeded organic waste material is introduced into the bottom of the expanded bed reactor which includes a particulate support media coated with a polysaccharide film. A low-velocity upward flow of the organic waste material is established through the bed during which the attached bacterial film reacts with the organic material to produce methane and carbon dioxide gases, purified water, and a small amount of residual effluent material. The residual effluent material is filtered by the film as it flows upwardly through the reactor bed. In a preferred embodiment, partially treated effluent material is recycled from the top of the bed to the bottom of the bed for further treatment. The methane and carbon dioxide gases are then separated from the residual effluent material and purified water.

  6. Methane sources and emissions in Italy

    SciTech Connect (OSTI)

    Guidotti, G.R.; Castagnola, A.M.

    1994-12-31

    Methane emissions in Italy were assessed in the framework of the measures taken to follow out the commitments undertaken at the 1992 U.N. Conference for Environment and Development. Methane emissions of anthropic origin were estimated to be in the range of 1.6 to 2.3 million ton of methane per year. Some of these methane sources (natural gas production, transmission and distribution; rice paddies; managed livestock enteric fermentation and waste; solid waste landfills) are given here particular care as they mainly contribute to the total methane emission budget.

  7. Effects of a gradually increased load of fish waste silage in co-digestion with cow manure on methane production

    SciTech Connect (OSTI)

    Solli, Linn Bergersen, Ove; Sørheim, Roald; Briseid, Tormod

    2014-08-15

    Highlights: • New results from continuous anaerobic co-digestion of fish waste silage (FWS) and cow manure (CM). • Co-digestion of FWS and CM has a high biogas potential. • Optimal mixing ratio of FWS/CM is 13–16/87–84 volume%. • High input of FWS leads to accumulation of NH4+ and VFAs and process failure. - Abstract: This study examined the effects of an increased load of nitrogen-rich organic material on anaerobic digestion and methane production. Co-digestion of fish waste silage (FWS) and cow manure (CM) was studied in two parallel laboratory-scale (8 L effective volume) semi-continuous stirred tank reactors (designated R1 and R2). A reactor fed with CM only (R0) was used as control. The reactors were operated in the mesophilic range (37 °C) with a hydraulic retention time of 30 days, and the entire experiment lasted for 450 days. The rate of organic loading was raised by increasing the content of FWS in the feed stock. During the experiment, the amount (volume%) of FWS was increased stepwise in the following order: 3% – 6% – 13% – 16%, and 19%. Measurements of methane production, and analysis of volatile fatty acids, ammonium and pH in the effluents were carried out. The highest methane production from co-digestion of FWS and CM was 0.400 L CH4 gVS{sup −1}, obtained during the period with loading of 16% FWS in R2. Compared to anaerobic digestion of CM only, the methane production was increased by 100% at most, when FWS was added to the feed stock. The biogas processes failed in R1 and R2 during the periods, with loadings of 16% and 19% FWS, respectively. In both reactors, the biogas processes failed due to overloading and accumulation of ammonia and volatile fatty acids.

  8. Incentives for Methane Mitigation and Energy-Efficiency Improvements in Case of Ukraine’s Natural Gas Transmission System

    SciTech Connect (OSTI)

    Roshchanka, Volha; Evans, Meredydd

    2014-06-01

    Reducing methane losses is a concern for climate change policy and energy policy. The energy sector is the major source of methane emissions into the atmosphere. Reducing methane emissions and avoiding combustion can be very cost-effective, but various barriers prevent such energy-efficiency measures from taking place. To date, few examples of industry-wide improvements exist. One example of substantial investments into upgrading natural gas transmission system comes from Ukraine. The Ukrainian transmission company, Ukrtransgaz, reduced its own system’s natural gas consumption by 68 percent in 2011 compared to the level in 2005. Evaluating reductions in methane emissions is challenging because of lack of accurate data and gaps in accounting methodologies. At the same time, Ukraine’s transmission system has undergone improvements that, at the very least, have contained methane emissions, if not substantially reduced them. In this paper, we describe recent developments in Ukraine’s natural gas transmission system and analyze the incentives that forced the sector to pay close attention to its methane losses. Ukraine is one of most energy-intensive countries, among the largest natural gas consumers in the world, and a significant emitter of methane. The country is also dependent on imports of natural gas. A combination of steep increases in the price of imported natural gas, and comprehensive domestic environmental and energy policies, regional integration policy, and international environmental agreements has created conditions for successful methane emission and combustion reductions. Learning about such case studies can help us design better policies elsewhere.

  9. Turbulent burning rates of methane and methane-hydrogen mixtures

    SciTech Connect (OSTI)

    Fairweather, M. [School of Process, Environmental and Materials Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom); Ormsby, M.P.; Sheppard, C.G.W. [School of Mechanical Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom); Woolley, R. [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2009-04-15

    Methane and methane-hydrogen (10%, 20% and 50% hydrogen by volume) mixtures have been ignited in a fan stirred bomb in turbulence and filmed using high speed cine schlieren imaging. Measurements were performed at 0.1 MPa (absolute) and 360 K. A turbulent burning velocity was determined for a range of turbulence velocities and equivalence ratios. Experimental laminar burning velocities and Markstein numbers were also derived. For all fuels the turbulent burning velocity increased with turbulence velocity. The addition of hydrogen generally resulted in increased turbulent and laminar burning velocity and decreased Markstein number. Those flames that were less sensitive to stretch (lower Markstein number) burned faster under turbulent conditions, especially as the turbulence levels were increased, compared to stretch-sensitive (high Markstein number) flames. (author)

  10. Large-scale simulation of methane dissociation along the West Spitzbergen Margin

    SciTech Connect (OSTI)

    Reagan, M.T.; Moridis, G.J.

    2009-07-15

    Vast quantities of methane are trapped in oceanic hydrate deposits, and there is concern that a rise in the ocean temperature will induce dissociation of these hydrate accumulations, potentially releasing large amounts of methane into the atmosphere. The recent discovery of active methane gas venting along the landward limit of the gas hydrate stability zone (GHSZ) on the shallow continental slope west of Spitsbergen could be an indication of this process, if the source of the methane can be confidently attributed to dissociating hydrates. In the first large-scale simulation study of its kind, we simulate shallow hydrate dissociation in conditions representative of the West Spitsbergen margin to test the hypothesis that the observed gas release originated from hydrates. The simulation results are consistent with this hypothesis, and are in remarkable agreement with the recently published observations. They show that shallow, low-saturation hydrate deposits, when subjected to temperature increases at the seafloor, can release significant quantities of methane, and that the releases will be localized near the landward limit of the top of the GHSZ. These results indicate the possibility that hydrate dissociation and methane release may be both a consequence and a cause of climate change.

  11. Contribution of oceanic gas hydrate dissociation to the formation of Arctic Ocean methane plumes

    SciTech Connect (OSTI)

    Reagan, M.; Moridis, G.; Elliott, S.; Maltrud, M.

    2011-06-01

    Vast quantities of methane are trapped in oceanic hydrate deposits, and there is concern that a rise in the ocean temperature will induce dissociation of these hydrate accumulations, potentially releasing large amounts of carbon into the atmosphere. Because methane is a powerful greenhouse gas, such a release could have dramatic climatic consequences. The recent discovery of active methane gas venting along the landward limit of the gas hydrate stability zone (GHSZ) on the shallow continental slope (150 m - 400 m) west of Svalbard suggests that this process may already have begun, but the source of the methane has not yet been determined. This study performs 2-D simulations of hydrate dissociation in conditions representative of the Arctic Ocean margin to assess whether such hydrates could contribute to the observed gas release. The results show that shallow, low-saturation hydrate deposits, if subjected to recently observed or future predicted temperature changes at the seafloor, can release quantities of methane at the magnitudes similar to what has been observed, and that the releases will be localized near the landward limit of the GHSZ. Both gradual and rapid warming is simulated, along with a parametric sensitivity analysis, and localized gas release is observed for most of the cases. These results resemble the recently published observations and strongly suggest that hydrate dissociation and methane release as a result of climate change may be a real phenomenon, that it could occur on decadal timescales, and that it already may be occurring.

  12. ARM - Evaluation Product - AmeriFlux and Methane VAP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    IL 60439 Resource(s) Data Directory, ReadMe Data Format netcdf, csv Data Usage These files contain ecosystem fluxes of water, energy, CO2, and CH4 that have been fully corrected. ...

  13. The Methane to Markets Coal Mine Methane Subcommittee meeting

    SciTech Connect (OSTI)

    2008-07-01

    The presentations (overheads/viewgraphs) include: a report from the Administrative Support Group; strategy updates from Australia, India, Italy, Mexico, Nigeria, Poland and the USA; coal mine methane update and IEA's strategy and activities; the power of VAM - technology application update; the emissions trading market; the voluntary emissions reduction market - creating profitable CMM projects in the USA; an Italian perspective towards a zero emission strategies; and the wrap-up and summary.

  14. May 15, 2014 Methane Hydrates Committee Meeting Agenda | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy May 15, 2014 Methane Hydrates Committee Meeting Agenda May 15, 2014 Methane Hydrates Committee Meeting Agenda May 15, 2014 Methane Hydrates Committee Meeting Agenda Meeting Agenda (443.71 KB) More Documents & Publications Advisory Committee Meeting Minutes, May 7, 2015 Methane Hydrate Program Reports Report of the Task Force on Methane Hydrates

  15. Methane Hydrate Program Annual Report to Congress

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    FY 2010 Methane Hydrate Program Annual Report to Congress September 2011 U.S. Department of ENERGY United States Department of Energy Washington, DC 20585 Department of Energy | September 2011 FY 2010 Methane Hydrate Program Annual Report to Congress | Page 2 Message from the Secretary Section 968 of the Energy Policy Act of 2005 requires the Department of Energy to submit to Congress an annual report on the results of methane hydrate research. I am pleased to submit the enclosed report

  16. Atmospheric Emitted Radiance Interferometer

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Gero, Jonathan; Ermold, Brian; Gaustad, Krista; Koontz, Annette; Hackel, Denny; Garcia, Raymond

    2005-01-01

    The atmospheric emitted radiance interferometer (AERI) is a ground-based instrument that measures the downwelling infrared radiance from the Earth’s atmosphere. The observations have broad spectral content and sufficient spectral resolution to discriminate among gaseous emitters (e.g., carbon dioxide and water vapor) and suspended matter (e.g., aerosols, water droplets, and ice crystals). These upward-looking surface observations can be used to obtain vertical profiles of tropospheric temperature and water vapor, as well as measurements of trace gases (e.g., ozone, carbon monoxide, and methane) and downwelling infrared spectral signatures of clouds and aerosols. The AERI is a passive remote sounding instrument, employing a Fourier transform spectrometer operating in the spectral range 3.3–19.2 μm (520–3020 cm-1) at an unapodized resolution of 0.5 cm-1 (max optical path difference of 1 cm). The extended-range AERI (ER-AERI) deployed in dry climates, like in Alaska, have a spectral range of 3.3–25.0 μm (400–3020 cm-1) that allow measurements in the far-infrared region. Typically, the AERI averages views of the sky over a 16-second interval and operates continuously.

  17. Modeling Methane Adsorption in Interpenetrating Porous Polymer...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Modeling Methane Adsorption in Interpenetrating Porous Polymer Networks Previous Next List Richard L. Martin, Mahdi Niknam Shahrak, Joseph A. Swisher, Cory M. Simon, Julian P....

  18. EIA - Greenhouse Gas Emissions - Methane Emissions

    Gasoline and Diesel Fuel Update (EIA)

    3. Methane Emissions 3.1. Total emissions The major sources of U.S. methane emissions are energy production, distribution, and use; agriculture; and waste management (Figure 17). U.S. methane emissions in 2009 totaled 731 MMTCO2e, 0.9 percent higher than the 2008 total of 724 MMTCO2e (Table 17). Methane emissions declined steadily from 1990 to 2001, as emissions from coal mining and landfills fell, then rose from 2002 to 2009 as a result of moderate increases in emissions related to energy,

  19. CO2/CH4, CH4/H2 and CO2/CH4/H2 separations at high pressures...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Mg-MOF-74 or CPO-27-Mg, is an especially lightweight metal-organic framework with a high concentration of coordinatively-unsaturated metal sites decorating its interior surfaces. ...

  20. New Methane Hydrate Research: Investing in Our Energy Future...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    New Methane Hydrate Research: Investing in Our Energy Future New Methane Hydrate Research: Investing in Our Energy Future August 31, 2012 - 1:37pm Addthis Methane hydrates are 3D ...

  1. Methane for Power Generation in Muaro Jambi: A Green Prosperity Model Project

    SciTech Connect (OSTI)

    Moriarty, K.; Elchinger, M.; Hill, G.; Katz, J.; Barnett, J.

    2014-07-01

    NREL conducted eight model projects for Millennium Challenge Corporation's (MCC) Compact with Indonesia. Green Prosperity, the largest project of the Compact, seeks to address critical constraints to economic growth while supporting the Government of Indonesia's commitment to a more sustainable, less carbon-intensive future. This study evaluates electricity generation from the organic content of wastewater at a palm oil mill in Muaro Jambi, Sumatra. Palm mills use vast amounts of water in the production process resulting in problematic waste water called palm oil mill effluent (POME). The POME releases methane to the atmosphere in open ponds which could be covered to capture the methane to produce renewable electricity for rural villages. The study uses average Indonesia data to determine the economic viability of methane capture at a palm oil mill and also evaluates technology as well as social and environmental impacts of the project.

  2. Methane Hydrate Advisory Committee Meetings | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Meetings Methane Hydrate Advisory Committee Meetings May 7, 2015 Advisory Committee ... Federal Register Notice for May 15, 2014 Meeting Methane Hydrates Committee Meeting Agenda ...

  3. Estimating global and North American methane emissions with high...

    Office of Scientific and Technical Information (OSTI)

    methane emissions with high spatial resolution using GOSAT satellite data Citation Details In-Document Search Title: Estimating global and North American methane emissions ...

  4. Methane Hydrate Advisory Committee Meeting Minutes, October 2011...

    Office of Environmental Management (EM)

    October 2011 Methane Hydrate Advisory Committee Meeting Minutes, October 2011 Methane Hydrate Advisory Committee Meeting Minutes October 2011 Washington, DC PDF icon Advisory...

  5. Landfill Methane Project Development Handbook | Open Energy Informatio...

    Open Energy Info (EERE)

    Methane Project Development Handbook Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Landfill Methane Project Development Handbook AgencyCompany Organization: United...

  6. US EPA Landfill Methane Outreach Program | Open Energy Information

    Open Energy Info (EERE)

    EPA Landfill Methane Outreach Program Jump to: navigation, search Name US EPA Landfill Methane Outreach Program AgencyCompany Organization United States Environmental Protection...

  7. Data from Innovative Methane Hydrate Test on Alaska's North Slope...

    Office of Environmental Management (EM)

    Data from Innovative Methane Hydrate Test on Alaska's North Slope Now Available on NETL Website Data from Innovative Methane Hydrate Test on Alaska's North Slope Now Available on ...

  8. Louisiana--State Offshore Coalbed Methane Proved Reserves (Billion...

    U.S. Energy Information Administration (EIA) Indexed Site

    Louisiana--State Offshore Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade ...312016 Referring Pages: Coalbed Methane Proved Reserves as of Dec. 31 LA, State Offshore

  9. ,"Lower 48 Federal Offshore Coalbed Methane Proved Reserves ...

    U.S. Energy Information Administration (EIA) Indexed Site

    Data for" ,"Data 1","Lower 48 Federal Offshore Coalbed Methane Proved Reserves (Billion ... to Contents","Data 1: Lower 48 Federal Offshore Coalbed Methane Proved Reserves (Billion ...

  10. Lower 48 Federal Offshore Coalbed Methane Proved Reserves (Billion...

    U.S. Energy Information Administration (EIA) Indexed Site

    Lower 48 Federal Offshore Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade ...2016 Referring Pages: Coalbed Methane Proved Reserves as of Dec. 31 Federal Offshore U.S.

  11. ,"Texas (with State Offshore) Coalbed Methane Proved Reserves...

    U.S. Energy Information Administration (EIA) Indexed Site

    Data for" ,"Data 1","Texas (with State Offshore) Coalbed Methane Proved Reserves ... to Contents","Data 1: Texas (with State Offshore) Coalbed Methane Proved Reserves ...

  12. ,"Alaska (with Total Offshore) Coalbed Methane Proved Reserves...

    U.S. Energy Information Administration (EIA) Indexed Site

    Data for" ,"Data 1","Alaska (with Total Offshore) Coalbed Methane Proved Reserves ... to Contents","Data 1: Alaska (with Total Offshore) Coalbed Methane Proved Reserves ...

  13. ,"Louisiana--State Offshore Coalbed Methane Proved Reserves ...

    U.S. Energy Information Administration (EIA) Indexed Site

    Data for" ,"Data 1","Louisiana--State Offshore Coalbed Methane Proved Reserves (Billion ... to Contents","Data 1: Louisiana--State Offshore Coalbed Methane Proved Reserves (Billion ...

  14. ,"Federal Offshore--Texas Coalbed Methane Proved Reserves (Billion...

    U.S. Energy Information Administration (EIA) Indexed Site

    Data for" ,"Data 1","Federal Offshore--Texas Coalbed Methane Proved Reserves ... AM" "Back to Contents","Data 1: Federal Offshore--Texas Coalbed Methane Proved Reserves ...

  15. ,"Louisiana (with State Offshore) Coalbed Methane Proved Reserves...

    U.S. Energy Information Administration (EIA) Indexed Site

    for" ,"Data 1","Louisiana (with State Offshore) Coalbed Methane Proved Reserves ... Contents","Data 1: Louisiana (with State Offshore) Coalbed Methane Proved Reserves ...

  16. Texas--State Offshore Coalbed Methane Proved Reserves (Billion...

    U.S. Energy Information Administration (EIA) Indexed Site

    State Offshore Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade Year-0 Year-1 ...312016 Referring Pages: Coalbed Methane Proved Reserves as of Dec. 31 TX, State Offshore

  17. ,"Texas--State Offshore Coalbed Methane Proved Reserves (Billion...

    U.S. Energy Information Administration (EIA) Indexed Site

    Data for" ,"Data 1","Texas--State Offshore Coalbed Methane Proved Reserves (Billion ... "Back to Contents","Data 1: Texas--State Offshore Coalbed Methane Proved Reserves (Billion ...

  18. New York Coalbed Methane Production (Billion Cubic Feet)

    Gasoline and Diesel Fuel Update (EIA)

    Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane Estimated Production New York Coalbed Methane Proved Reserves, Reserves Changes, and ...

  19. New York Coalbed Methane Proved Reserves (Billion Cubic Feet...

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane Proved Reserves as of Dec. 31 New York Coalbed Methane Proved Reserves, Reserves Changes, ...

  20. Methane and Methanotrophic Bacteria as a Biotechnological Platform...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Methane and Methanotrophic Bacteria as a Biotechnological Platform Methane and Methanotrophic Bacteria as a Biotechnological Platform Breakout Session 2-B: NewEmerging Pathways ...

  1. ,"North Dakota Coalbed Methane Proved Reserves (Billion Cubic...

    U.S. Energy Information Administration (EIA) Indexed Site

    Data for" ,"Data 1","North Dakota Coalbed Methane Proved Reserves ... 9:22:44 AM" "Back to Contents","Data 1: North Dakota Coalbed Methane Proved Reserves ...

  2. ,"Louisiana--North Coalbed Methane Proved Reserves (Billion Cubic...

    U.S. Energy Information Administration (EIA) Indexed Site

    Data for" ,"Data 1","Louisiana--North Coalbed Methane Proved Reserves (Billion ... "Back to Contents","Data 1: Louisiana--North Coalbed Methane Proved Reserves (Billion ...

  3. Louisiana--South Onshore Coalbed Methane Proved Reserves (Billion...

    U.S. Energy Information Administration (EIA) Indexed Site

    South Onshore Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade Year-0 Year-1 ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  4. Alaska (with Total Offshore) Coalbed Methane Proved Reserves...

    U.S. Energy Information Administration (EIA) Indexed Site

    Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3 ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  5. U.S. Coalbed Methane Proved Reserves Extensions (Billion Cubic...

    U.S. Energy Information Administration (EIA) Indexed Site

    Extensions (Billion Cubic Feet) U.S. Coalbed Methane Proved Reserves Extensions (Billion ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  6. U.S. Coalbed Methane Proved Reserves New Reservoir Discoveries...

    U.S. Energy Information Administration (EIA) Indexed Site

    New Reservoir Discoveries in Old Fields (Billion Cubic Feet) U.S. Coalbed Methane Proved ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  7. ,"Alabama Coalbed Methane Proved Reserves (Billion Cubic Feet...

    U.S. Energy Information Administration (EIA) Indexed Site

    Coalbed Methane Proved Reserves (Billion Cubic Feet)" ,"Click worksheet name or tab at ... Data for" ,"Data 1","Alabama Coalbed Methane Proved Reserves (Billion Cubic ...

  8. U.S. Coalbed Methane Production (Billion Cubic Feet)

    U.S. Energy Information Administration (EIA) Indexed Site

    Production (Billion Cubic Feet) U.S. Coalbed Methane Production (Billion Cubic Feet) ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  9. Texas--RRC District 5 Coalbed Methane Proved Reserves (Billion...

    U.S. Energy Information Administration (EIA) Indexed Site

    5 Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3 ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  10. Texas--RRC District 1 Coalbed Methane Proved Reserves (Billion...

    U.S. Energy Information Administration (EIA) Indexed Site

    1 Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3 ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  11. Towards a Computational Model of a Methane Producing Archaeum...

    Office of Scientific and Technical Information (OSTI)

    Towards a Computational Model of a Methane Producing Archaeum Citation Details In-Document Search Title: Towards a Computational Model of a Methane Producing Archaeum Authors: ...

  12. Texas--RRC District 9 Coalbed Methane Proved Reserves (Billion...

    U.S. Energy Information Administration (EIA) Indexed Site

    9 Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3 ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  13. U.S. Coalbed Methane Proved Reserves Revision Increases (Billion...

    U.S. Energy Information Administration (EIA) Indexed Site

    Increases (Billion Cubic Feet) U.S. Coalbed Methane Proved Reserves Revision Increases ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  14. ,"Wyoming Coalbed Methane Proved Reserves (Billion Cubic Feet...

    U.S. Energy Information Administration (EIA) Indexed Site

    Coalbed Methane Proved Reserves (Billion Cubic Feet)" ,"Click worksheet name or tab at ... Data for" ,"Data 1","Wyoming Coalbed Methane Proved Reserves (Billion Cubic ...

  15. Michigan Coalbed Methane Proved Reserves (Billion Cubic Feet...

    U.S. Energy Information Administration (EIA) Indexed Site

    Michigan Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade Year-0 Year-1 Year-2 ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  16. U.S. Coalbed Methane Proved Reserves Revision Decreases (Billion...

    U.S. Energy Information Administration (EIA) Indexed Site

    Decreases (Billion Cubic Feet) U.S. Coalbed Methane Proved Reserves Revision Decreases ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  17. Texas--RRC District 8 Coalbed Methane Proved Reserves (Billion...

    U.S. Energy Information Administration (EIA) Indexed Site

    Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3 ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  18. U.S. Coalbed Methane Proved Reserves (Billion Cubic Feet)

    U.S. Energy Information Administration (EIA) Indexed Site

    (Billion Cubic Feet) U.S. Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  19. U.S. Coalbed Methane Proved Reserves Adjustments (Billion Cubic...

    U.S. Energy Information Administration (EIA) Indexed Site

    Adjustments (Billion Cubic Feet) U.S. Coalbed Methane Proved Reserves Adjustments (Billion ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  20. Mississippi (with State off) Coalbed Methane Proved Reserves...

    U.S. Energy Information Administration (EIA) Indexed Site

    Mississippi (with State off) Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  1. ,"Utah Coalbed Methane Proved Reserves (Billion Cubic Feet)"

    U.S. Energy Information Administration (EIA) Indexed Site

    Coalbed Methane Proved Reserves (Billion Cubic Feet)" ,"Click worksheet name or tab at ... Data for" ,"Data 1","Utah Coalbed Methane Proved Reserves (Billion Cubic ...

  2. U.S. Coalbed Methane Proved Reserves Acquisitions (Billion Cubic...

    U.S. Energy Information Administration (EIA) Indexed Site

    Acquisitions (Billion Cubic Feet) U.S. Coalbed Methane Proved Reserves Acquisitions ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  3. Florida Coalbed Methane Proved Reserves (Billion Cubic Feet)

    U.S. Energy Information Administration (EIA) Indexed Site

    Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3 ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  4. Process for separating nitrogen from methane using microchannel...

    Office of Scientific and Technical Information (OSTI)

    Process for separating nitrogen from methane using microchannel process technology Citation Details In-Document Search Title: Process for separating nitrogen from methane using ...

  5. ,"Colorado Coalbed Methane Proved Reserves (Billion Cubic Feet...

    U.S. Energy Information Administration (EIA) Indexed Site

    Coalbed Methane Proved Reserves (Billion Cubic Feet)" ,"Click worksheet name or tab at ... Data for" ,"Data 1","Colorado Coalbed Methane Proved Reserves (Billion Cubic ...

  6. Texas--RRC District 6 Coalbed Methane Proved Reserves (Billion...

    U.S. Energy Information Administration (EIA) Indexed Site

    6 Coalbed Methane Proved Reserves (Billion Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3 ... Release Date: 11192015 Next Release Date: 12312016 Referring Pages: Coalbed Methane ...

  7. A model of the methane cycle, permafrost, and hydrology of the Siberian continental margin

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Archer, D.

    2015-05-21

    A two-dimensional model of a sediment column, with Darcy fluid flow, biological and thermal methane production, and permafrost and methane hydrate formation, is subjected to glacial–interglacial cycles in sea level, alternately exposing the continental shelf to the cold atmosphere during glacial times and immersing it in the ocean in interglacial times. The glacial cycles are followed by a "long-tail" 100 kyr warming due to fossil fuel combustion. The salinity of the sediment column in the interior of the shelf can be decreased by hydrological forcing to depths well below sea level when the sediment is exposed to the atmosphere. Theremore » is no analogous advective seawater-injecting mechanism upon resubmergence, only slower diffusive mechanisms. This hydrological ratchet is consistent with the existence of freshwater beneath the sea floor on continental shelves around the world, left over from the last glacial period. The salt content of the sediment column affects the relative proportions of the solid and fluid H2O-containing phases, but in the permafrost zone the salinity in the pore fluid brine is a function of temperature only, controlled by equilibrium with ice. Ice can tolerate a higher salinity in the pore fluid than methane hydrate can at low pressure and temperature, excluding methane hydrate from thermodynamic stability in the permafrost zone. The implication is that any methane hydrate existing today will be insulated from anthropogenic climate change by hundreds of meters of sediment, resulting in a response time of thousands of years. The strongest impact of the glacial–interglacial cycles on the atmospheric methane flux is due to bubbles dissolving in the ocean when sea level is high. When sea level is low and the sediment surface is exposed to the atmosphere, the atmospheric flux is sensitive to whether permafrost inhibits bubble migration in the model. If it does, the atmospheric flux is highest during the glaciating, sea level regression

  8. Methane flux from mangrove sediments along the southwestern coast of Puerto Rico

    SciTech Connect (OSTI)

    Sotomayor, D.; Corredor, J.E.; Morell, J.M. )

    1994-03-01

    Although the sediments of coastal marine mangrove forests have been considered a minor source of atmospheric methane, these estimate have been based on sparse data from similar areas. We have gathered evidence that shows that external nutrient and freshwater loading in mangrove sediments may have a significant effect on methane flux. Experiments were performed to examine methane fluxes from anaerobic sediments in a mangrove forest subjected to secondary sewage effluents on the southwestern coast of Puerto Rico. Emission rates were measured in situ using a static chamber technique, and subsequent laboratory analysis of samples was by gas chromatography using a flame ionization detector. Results indicate that methane flux rates were lowest at the landward fringe nearest to the effluent discharge, higher in the seaward fringe occupied by red mangroves, and highest in the transition zone between black and red mangrove communities, with average values of 4 mg CH[sub 4] m[sup [minus]2] d[sup [minus]1], 42 mg CH[sub 4] m[sup [minus]2] d[sup [minus]1], and 82 mg CH[sub 4] m[sup [minus]2] d[sup [minus]1], respectively. Overall mean values show these sediments may emit as much as 40 times more methane than unimpacted pristine areas. Pneumatophores of Aviciennia germinans have been found to serve as conduits to the atmosphere for this gas. Fluctuating water level overlying the mangrove sediment is an important environmental factor controlling seasonal and interannual CH[sub 4] flux variations. Environmental controls such as freshwater inputs and increased nutrient loading influence in situ methane emissions from these environments. 34 refs., 3 figs., 3 tabs.

  9. Inorganic Carbon Isotopes and Chemical Characterization of Watershed Drainages, Barrow, Alaska, 2013

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Throckmorton, Heather M.; Heikoop, Jeffrey H.; Newman, Brent D.; Wilson, Cathy J.

    Arctic soils contain a large pool of terrestrial C and are of interest due to their potential for releasing significant carbon dioxide (CO2) and methane (CH4) to the atmosphere. Due to substantial landscape heterogeneity, predicting ecosystem-scale CH4 and CO2 production is challenging. This study assessed dissolved inorganic carbon (DIC = Sigma (total) dissolved CO2) and CH4 in watershed drainages in Barrow, Alaska as critical convergent zones of regional geochemistry, substrates, and nutrients. In July and September of 2013, surface waters and saturated subsurface pore waters were collected from 17 drainages. Based on simultaneous DIC and CH4 cycling, we synthesized isotopic and geochemical methods to develop a subsurface CH4 and DIC balance by estimating mechanisms of CH4 and DIC production and transport pathways and oxidation of subsurface CH4. We observed a shift from acetoclastic (July) towards hydrogenotropic (September) methanogenesis at sites located towards the end of major freshwater drainages, adjacent to salty estuarine waters, suggesting an interesting landscape-scale effect on CH4 production mechanism. The majority of subsurface CH4 was transported upward by plant-mediated transport and ebullition, predominantly bypassing the potential for CH4 oxidation. Thus, surprisingly CH4 oxidation only consumed approximately 2.51 +/- 0.82% (July) and 0.79 +/- 0.79% (September) of CH4 produced at the frost table, contributing to less than 0.1% of DIC production. DIC was primarily produced from respiration, with iron and organic matter serving as likely e- acceptors. This work highlights the importance of spatial and temporal variability of CH4 production at the watershed scale, and suggests broad scale investigations are required to build better regional or pan-Arctic representations of CH4 and CO2 production.

  10. Some U.S. Methane Sources May Be Larger than Previously Thought...

    Office of Science (SC) Website

    ... The spatial patterns of emission fluxes and observed CH4 -propane correlations indicate that fossil fuel extraction and refining are major contributors (45%) in the south-central ...