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Sample records for hydrothermal co2 degassing

  1. Diffuse CO2 degassing at Vesuvio, Italy

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    Frondini, Francesco; Chiodini, Giovanni; Caliro, Stefano; Cardellini, Carlo; Granieri, Domenico; Ventura, Guido

    2004-10-01

    At Vesuvio, a significant fraction of the rising hydrothermal-volcanic fluids is subjected to a condensation and separation process producing a CO2-rich gas phase, mainly expulsed through soil diffuse degassing from well defined areas called diffuse degassing structures (DDS), and a liquid phase that flows towards the outer part of the volcanic cone. A large amount of thermal energy is associated with the steam condensation process and subsequent cooling of the liquid phase. The total amount of volcanic-hydrothermal CO2 discharged through diffuse degassing has been computed through a sequential Gaussian simulation (sGs) approach based on several hundred accumulation chamber measurements and, at the time of the survey, amounted to 151 t d-1. The steam associated with the CO2 output, computed assuming that the original H2O/CO2 ratio of hydrothermal fluids is preserved in fumarolic effluents, is 553 t d-1, and the energy produced by the steam condensation and cooling of the liquid phase is 1.47×1012 J d-1 (17 MW). The location of the CO2 and temperature anomalies show that most of the gas is discharged from the inner part of the crater and suggests that crater morphology and local stratigraphy exert strong control on CO2 degassing and subsurface steam condensation. The amounts of gas and energy released by Vesuvio are comparable to those released by other volcanic degassing areas of the world and their estimates, through periodic surveys of soil CO2 flux, can constitute a useful tool to monitor volcanic activity.

  2. Unraveling the dynamics of magmatic CO2 degassing at Mammoth Mountain, California

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    Peiffer, Loïc; Wanner, Christoph; Lewicki, Jennifer L.

    2018-02-01

    The accumulation of magmatic CO2 beneath low-permeability barriers may lead to the formation of CO2-rich gas reservoirs within volcanic systems. Such accumulation is often evidenced by high surface CO2 emissions that fluctuate over time. The temporal variability in surface degassing is believed in part to reflect a complex interplay between deep magmatic degassing and the permeability of degassing pathways. A better understanding of the dynamics of CO2 degassing is required to improve monitoring and hazards mitigation in these systems. Owing to the availability of long-term records of CO2 emissions rates and seismicity, Mammoth Mountain in California constitutes an ideal site towards such predictive understanding. Mammoth Mountain is characterized by intense soil CO2 degassing (up to ∼1000 t d-1) and tree kill areas that resulted from leakage of CO2 from a CO2-rich gas reservoir located in the upper ∼4 km. The release of CO2-rich fluids from deeper basaltic intrusions towards the reservoir induces seismicity and potentially reactivates faults connecting the reservoir to the surface. While this conceptual model is well-accepted, there is still a debate whether temporally variable surface CO2 fluxes directly reflect degassing of intrusions or variations in fault permeability. Here, we report the first large-scale numerical model of fluid and heat transport for Mammoth Mountain. We discuss processes (i) leading to the initial formation of the CO2-rich gas reservoir prior to the occurrence of high surface CO2 degassing rates and (ii) controlling current CO2 degassing at the surface. Although the modeling settings are site-specific, the key mechanisms discussed in this study are likely at play at other volcanic systems hosting CO2-rich gas reservoirs. In particular, our model results illustrate the role of convection in stripping a CO2-rich gas phase from a rising hydrothermal fluid and leading to an accumulation of a large mass of CO2 (∼107-108 t) in a shallow

  3. Surface geothermal exploration in the Canary Islands by means of soil CO_{2} degassing surveys

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    García-Merino, Marta; Rodríguez, Fátima; Padrón, Eleazar; Melián, Gladys; Asensio-Ramos, María; Barrancos, José; Hernández, Pedro A.; Pérez, Nemesio M.

    2017-04-01

    With the exception of the Teide fumaroles, there is not any evidence of hydrothermal fluid discharges in the surficial environment of the Canary Islands, the only Spanish territory with potential high enthalpy geothermal resources. Here we show the results of several diffuse CO2 degassing surveys carried out at five mining licenses in Tenerife and Gran Canaria with the aim of sorting the possible geothermal potential of these five mining licenses. The primary objective of the study was to reduce the uncertainty inherent to the selection of the areas with highest geothermal potential for future exploration works. The yardstick used to classify the different areas was the contribution of volcano-hydrothermal CO2 in the diffuse CO2 degassing at each study area. Several hundreds of measurements of diffuse CO2 emission, soil CO2 concentration and isotopic composition were performed at each mining license. Based in three different endmembers (biogenic, atmospheric and deep-seated CO2) with different CO2 concentrations (100, 0.04 and 100%, respectively) and isotopic compositions (-24, -8 and -3 per mil vs. VPDB respectively) a mass balance to distinguish the different contribution of each endmember in the soil CO2 at each sampling site was made. The percentage of the volcano-hydrothermal contribution in the current diffuse CO2 degassing was in the range 0-19%. The Abeque mining license, that comprises part of the north-west volcanic rift of Tenerife, seemed to show the highest geothermal potential, with an average of 19% of CO2 being released from deep sources, followed by Atidama (south east of Gran Canaria) and Garehagua (southern volcanic rift of Tenerife), with 17% and 12% respectively.

  4. Diffuse soil CO_2 degassing from Linosa island

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    Dario Cellura

    2014-06-01

    Full Text Available Normal 0 14 false false false MicrosoftInternetExplorer4 Normal 0 14 false false false IT X-NONE X-NONE MicrosoftInternetExplorer4 Herein, we present and discuss the result of 148 measurements of soil CO2 flux performed for the first time in Linosa island (Sicily Channel, Italy, a Plio-Pleistocene volcanic complex no longer active but still of interest owing to its location within a seismically active portion of the Sicily Channel rift system. The main purpose of this survey was to assess the occurrence of CO2 soil degassing, and compare flux estimations from this island with data of soil degassing from worldwide active volcanic as well as non-volcanic areas. To this aim soil CO2 fluxes were measured over a surface of about 4.2 km2 covering ~80% of the island. The soil CO2 degassing was observed to be mainly concentrated in the eastern part of the island likely due to volcano-tectonic lineaments, the presence of which is in good agreement with the known predominant regional faults system. Then, the collected data were interpreted using sequential Gaussian simulation that allowed estimating the total CO2 emissions of the island. Results show low levels of CO2 emissions from the soil of the island (~55 ton d-1 compared with CO2 emissions of currently active volcanic areas, such as Miyakejima (Japan and Vulcano (Italy. Results from this study suggest that soil degassing in Linosa is mainly fed by superficial organic activity with a moderate contribution of a deep CO2 likely driven by NW-SE trending active tectonic structures in the eastern part of the island.

  5. Unraveling the dynamics of magmatic CO2 degassing at Mammoth Mountain, California

    Science.gov (United States)

    Pfeiffer, Loic; Wanner, Christoph; Lewicki, Jennifer L.

    2018-01-01

    The accumulation of magmatic CO2 beneath low-permeability barriers may lead to the formation of CO2-rich gas reservoirs within volcanic systems. Such accumulation is often evidenced by high surface CO2 emissions that fluctuate over time. The temporal variability in surface degassing is believed in part to reflect a complex interplay between deep magmatic degassing and the permeability of degassing pathways. A better understanding of the dynamics of CO2 degassing is required to improve monitoring and hazards mitigation in these systems. Owing to the availability of long-term records of CO2 emissions rates and seismicity, Mammoth Mountain in California constitutes an ideal site towards such predictive understanding. Mammoth Mountain is characterized by intense soil CO2 degassing (up to ∼1000 t d−1) and tree kill areas that resulted from leakage of CO2 from a CO2-rich gas reservoir located in the upper ∼4 km. The release of CO2-rich fluids from deeper basaltic intrusions towards the reservoir induces seismicity and potentially reactivates faults connecting the reservoir to the surface. While this conceptual model is well-accepted, there is still a debate whether temporally variable surface CO2 fluxes directly reflect degassing of intrusions or variations in fault permeability. Here, we report the first large-scale numerical model of fluid and heat transport for Mammoth Mountain. We discuss processes (i) leading to the initial formation of the CO2-rich gas reservoir prior to the occurrence of high surface CO2 degassing rates and (ii) controlling current CO2 degassing at the surface. Although the modeling settings are site-specific, the key mechanisms discussed in this study are likely at play at other volcanic systems hosting CO2-rich gas reservoirs. In particular, our model results illustrate the role of convection in stripping a CO2-rich gas phase from a rising hydrothermal fluid and leading to an accumulation of a large mass of CO2 (∼107–108

  6. CO2, SO2, and H2S Degassing Related to the 2009 Redoubt Eruption, Alaska

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    Werner, C. A.; Kelly, P. J.; Evans, W.; Doukas, M. P.; McGimsey, R. G.; Neal, C. A.

    2012-12-01

    The 2009 eruption of Redoubt Volcano, Alaska was particularly well monitored for volcanic gas emissions with 35 airborne measurements of CO2, SO2, and H2S that span from October 2008 to August 2010. Increases in CO2 degassing were detected up to 5 months prior to the eruption and varied between 3630 and 9020 tonnes per day (t/d) in the 6 weeks prior to the eruption. Increased pre-eruptive CO2 degassing was accompanied by comparatively low S emission, resulting in molar C/S ratios that ranged between 30-60. However, the C/S ratio dropped to 2.4 coincident with the first phreatic explosion on March 15, 2009, and remained steady during the explosive (March 22 - April 4, 2009), effusive dome-building (April 5 - July 1, 2009), and waning phases (August 2009 onward) of the eruption. Observations of ice-melt rates, melt water discharge, and water chemistry in the months leading up to the eruption suggested that surface waters represented drainage from surficial, perched reservoirs of condensed magmatic steam and glacial meltwater. While the surface waters were capable of scrubbing many thousands of t/d of SO2, sampling of these fluids revealed that only a few hundred tonnes of SO2 was reacting to a dissolved component each day. This is also much less than the ~ 2100 t/d SO2 expected from degassing of magma in the upper crust (3-6.5 km), where petrologic analysis shows the final magma equilibration occurred. Thus, the high pre-eruptive C/S ratios observed could reflect bulk degassing of upper-crustal magma followed by nearly complete loss of SO2 in a magmatic-hydrothermal system. Alternatively, high C/S ratios could be attributed to degassing of low silica andesitic magma that intruded into the mid-crust in the 5 months prior to eruption; modeling suggests that mixing of this magma with pre-existing high silica andesite magma or mush would have caused a reduction of the C/S ratio to a value consistent with that measured during the eruption. Monitoring emissions regularly

  7. Comparison of diffuse CO2 degassing at Miravalles and Rincón de la Vieja volcanoes (Guanacaste Province, Costa Rica)

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    Liegler, A.; Bakkar Hindeleh, H.; Deering, C. D.; Fentress, S. E.

    2015-12-01

    Volcanic gas emissions are a key component for monitoring volcanic activity, magmatic input of volatiles to the atmosphere and the assessment of geothermal potential in volcanic regions. Diffuse soil degassing has been shown to represent a major part of volcanic gas emissions. However, this type of gas emission has not yet been quantified in the Guanacaste province of Costa Rica; a region of the country with several large, active or dormant volcanoes. We conducted the first study of diffuse CO2 degassing at Rincón de la Vieja and Miravalles volcanoes, both located in Guanacaste. Diffuse degassing was measured using the accumulation chamber method to quantify CO2 flux in regions where hydrothermal surface features indicate anomalous activity. The total diffuse carbon dioxide flux estimated at Miravalles in two areas, together roughly 2 km2 in size, was 135 t/day and in several areas at Rincón de la Vieja a minimum of 4 t/day. Comparatively low flux values and a very local concentration (few m2) of CO2 flux were observed at the active Rincón de la Vieja volcano, compared to the dormant Miravalles volcano, where significant soil flux was found over extended areas, not only around vents. Our assessment of the origin of these differences leads to two possibilities depending on if the surface features on the two volcanoes are fed by a common hydrothermal system or two separate ones. In the former case, the different intensity of diffuse CO2 flux could indicate a different degassing behavior and stronger concentration of gas emissions at the active vent areas at Rincon de la Vieja. In the latter case, where the hydrothermal systems are not linked, the amount of CO2 degassed through the flanks of the volcanoes could indicate that different physical and chemical conditions are governing the degassing of the two systems.

  8. Caldera unrest driven by CO2-induced drying of the deep hydrothermal system.

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    Moretti, R; Troise, C; Sarno, F; De Natale, G

    2018-05-29

    Interpreting volcanic unrest is a highly challenging and non-unique problem at calderas, since large hydrothermal systems may either hide or amplify the dynamics of buried magma(s). Here we use the exceptional ground displacement and geochemical datasets from the actively degassing Campi Flegrei caldera (Southern Italy) to show that ambiguities disappear when the thermal evolution of the deep hydrothermal system is accurately tracked. By using temperatures from the CO 2 -CH 4 exchange of 13 C and thermodynamic analysis of gas ascending in the crust, we demonstrate that after the last 1982-84 crisis the deep hydrothermal system evolved through supercritical conditions under the continuous isenthalpic inflow of hot CO 2 -rich gases released from the deep (~8 km) magma reservoir of regional size. This resulted in the drying of the base of the hot hydrothermal system, no more buffered along the liquid-vapour equilibrium, and excludes any shallow arrival of new magma, whose abundant steam degassing due to decompression would have restored liquid-vapour equilibrium. The consequent CO 2 -infiltration and progressive heating of the surrounding deforming rock volume cause the build-up of pore pressure in aquifers, and generate the striking temporal symmetry that characterizes the ongoing uplift and the post-1984 subsidence, both originated by the same but reversed deformation mechanism.

  9. Soil CO2 Degassing Path along Volcano-Tectonic Structures in the Pico-Faial-São Jorge Islands (Azores Archipelago, Portugal

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    Fátima Viveiros

    2017-06-01

    Full Text Available The Azores archipelago is composed of nine volcanic islands located at the triple junction between the North American, Eurasian, and Nubian plates. Nowadays the volcanic activity in the archipelago is characterized by the presence of secondary manifestations of volcanism, such as hydrothermal fumaroles, thermal and cold CO2-rich springs as well as soil diffuse degassing areas, and low magnitude seismicity. Soil CO2 degassing (concentration and flux surveys have been performed at Pico, Faial, and São Jorge islands to identify possible diffuse degassing structures. Since the settlement of the Azores in the fifteenth Century these three islands were affected by seven onshore volcanic eruptions and at least six destructive earthquakes. These islands are crossed by numerous active tectonic structures with dominant WNW-ESE direction, and less abundant conjugate NNW-SSE trending faults. A total of 2,855 soil CO2 concentration measurements have been carried out with values varying from 0 to 20.7 vol.%. Soil CO2 flux measurements, using the accumulation chamber method, have also been performed at Pico and Faial islands in the summer of 2011 and values varied from absence of CO2 to 339 g m−2 d−1. The highest CO2 emissions were recorded at Faial Island and were associated with the Pedro Miguel graben faults, which seem to control the CO2 diffuse degassing and were interpreted as the pathways for the CO2 ascending from deep reservoirs to the surface. At São Jorge Island, four main degassing zones have been identified at the intersection of faults or associated to WNW-ESE tectonic structures. Four diffuse degassing structures were identified at Pico Island essentially where different faults intersect. Pico geomorphology is dominated by a 2,351 m high central volcano that presents several steam emissions at its summit. These emissions are located along a NW-SE fault and the highest measured soil CO2 concentration reached 7.6 vol.% with a maximum

  10. Diffuse CO2 degassing studies to reveal hidden geothermal resources in oceanic volcanic islands: The Canarian archipelago case study

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    Rodríguez, F.; Perez, N. M.; García-Merino, M.; Padron, E.; Melián, G.; Asensio-Ramos, M.; Hernandez Perez, P. A.; Padilla, G.; Barrancos, J.; Cótchico, M. A.

    2016-12-01

    The Canary Islands, owing to their recent volcanism, are the only Spanish territory with potential high enthalpy geothermal resources. The final goal of geothermal exploration in a specific area is to locate and define the size, shape, structure of hidden geothermal resources, and determine their characteristics (fluid type, temperature, chemical composition an ability to produce energy). At those areas where there is not any evidence of endogenous fluids manifestations at surface, that traditionally evidence the presence of an active geothermal system) the geochemical methods for geothermal exploration must include soil gas surveys. This is the case of five mining licenses for geothermal exploration in the Canay Islands, four in Tenerife and one in Gran Canaria Island. We report herein the results of diffuse CO2 emission studies in the five mining licenses during 2011-2014. The primary objective of the study was to sort the possible geothermal potential of these five mining licenses, thus reducing the uncertainty inherent to the selection of the areas with highest geothermal potential for future exploration works. The criterion used to sort the different areas was the contribution of volcano-hydrothermal CO2 in the degassing at each study area. Several hundreds of measurements of diffuse CO2 emission, soil CO2 concentration and isotopic composition were performed at each study area. Based in three different endmembers (biogenic, atmospheric and deep-seated CO2) with different CO2 concentrations (100, 0.04 and 100% respectively) and isotopic compositions (-20, -8 and -3 per mil vs. VPDB respectively) a mass balance to distinguish the different contribution of each endmember in the soil CO2 at each sampling site was made. The percentage of the volcano-hydrothermal contribution in the current diffuse CO2 degassing was in the range 2-19%.The Abeque mining license, that comprises part of the north-west volcanic rift of Tenerife, seemed to show the highest geothermal

  11. Integrated geophysical and hydrothermal models of flank degassing and fluid flow at Masaya Volcano, Nicaragua

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    Sanford, Ward E.; Pearson, S.C.P.; Kiyosugi, K.; Lehto, H.L.; Saballos, J.A.; Connor, C.B.

    2012-01-01

    We investigate geologic controls on circulation in the shallow hydrothermal system of Masaya volcano, Nicaragua, and their relationship to surface diffuse degassing. On a local scale (~250 m), relatively impermeable normal faults dipping at ~60° control the flowpath of water vapor and other gases in the vadose zone. These shallow normal faults are identified by modeling of a NE-SW trending magnetic anomaly of up to 2300 nT that corresponds to a topographic offset. Elevated SP and CO2 to the NW of the faults and an absence of CO2 to the SE suggest that these faults are barriers to flow. TOUGH2 numerical models of fluid circulation show enhanced flow through the footwalls of the faults, and corresponding increased mass flow and temperature at the surface (diffuse degassing zones). On a larger scale, TOUGH2 modeling suggests that groundwater convection may be occurring in a 3-4 km radial fracture zone transecting the entire flank of the volcano. Hot water rising uniformly into the base of the model at 1 x 10-5 kg/m2s results in convection that focuses heat and fluid and can explain the three distinct diffuse degassing zones distributed along the fracture. Our data and models suggest that the unusually active surface degassing zones at Masaya volcano can result purely from uniform heat and fluid flux at depth that is complicated by groundwater convection and permeability variations in the upper few km. Therefore isolating the effects of subsurface geology is vital when trying to interpret diffuse degassing in light of volcanic activity.

  12. Diffuse CO_{2} degassing monitoring of the oceanic active volcanic island of El Hierro, Canary Islands, Spain

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    Hernández, Pedro A.; Norrie, Janice; Withoos, Yannick; García-Merino, Marta; Melián, Gladys; Padrón, Eleazar; Barrancos, José; Padilla, Germán; Rodríguez, Fátima; Pérez, Nemesio M.

    2017-04-01

    Even during repose periods, volcanoes release large amounts of gases from both visible (fumaroles, solfataras, plumes) and non-visible emanations (diffuse degassing). In the last 20 years, there has been considerable interest in the study of diffuse degassing as a powerful tool in volcano monitoring programs, particularly in those volcanic areas where there are no visible volcanic-hydrothermal gas emissions. Historically, soil gas and diffuse degassing surveys in volcanic environments have focused mainly on CO2 because it is, after water vapor, the most abundant gas dissolved in magma. As CO2 travels upward by advective-diffusive transport mechanisms and manifests itself at the surface, changes in its flux pattern over time provide important information for monitoring volcanic and seismic activity. Since 1998, diffuse CO2 emission has been monitored at El Hierro Island, the smallest and south westernmost island of the Canarian archipelago with an area of 278 km2. As no visible emanations occur at the surface environment of El Hierro, diffuse degassing studies have become the most useful geochemical tool to monitor the volcanic activity in this volcanic island. The island experienced a volcano-seismic unrest that began in July 2011, characterized by the location of a large number of relatively small earthquakes (MHierro at depths between 8 and 15 km. On October 12, 2011, a submarine eruption was confirmed during the afternoon of October 12, 2011 by visual observations off the coast of El Hierro, about 2 km south of the small village of La Restinga in the southernmost part of the island. During the pre-eruptive and eruptive periods, the time series of the diffuse CO2 emission released by the whole island experienced two significant increases. The first started almost 2 weeks before the onset of the submarine eruption, reflecting a clear geochemical anomaly in CO2 emission, most likely due to increasing release of deep seated magmatic gases to the surface. The second

  13. Relationship between Diffuse CO2 Degassing and Volcanic Activity. Case Study of the Poás, Irazú, and Turrialba Volcanoes, Costa Rica

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    Matthieu Epiard

    2017-10-01

    Full Text Available Active volcanoes exhibit diffuse gas emanations through the ground, the most abundant species of which is CO2. However, the relationship between diffuse degassing and volcanic activity is not often clear and some volcanoes may have low diffuse degassing levels despite having strong volcanic activity. The main goals of this study are to quantify diffuse CO2 degassing and determine whether patterns exist in relation to volcanic activity through the study of Turrialba, Poás, and Irazú, three active volcanoes in Costa Rica which are at different stages of activity. Structural controls of spatial distribution of diffuse degassing were also investigated. Measurement campaigns were conducted using the accumulation chamber method coupled with 10 cm depth ground temperature sampling with the aim of estimating the total diffuse CO2 degassing budget. The total amount of CO2 emitted diffusely by each volcano is ~113 ± 46 t/d over ~0.705 km2 for Turrialba, 0.9 ± 0.5 t/d for Poás over ~0.734 km2, 3.8 ± 0.9 t/d over ~0.049 km2 for Irazú's main crater, and 15 ± 12 t/d over 0.0059 km2 for Irazú's north flank. Turrialba and Poás volcano diffuse degassing budget represent about 10% of the whole gas output. Both volcanoes were in a transitional stage and the opening of new conduits may cause a loss in diffuse degassing and an increase of active degassing. Numerous diffuse degassing structures were also identified. At Turrialba, one of which was closely associated with the collapse of a crater wall in 2014 during the initiation of a new period of heightened eruptive activity. Similar structures were also observed on the outer slopes of the west crater, suggesting strong alteration and perhaps destabilization of the upper outer cone. Irazú's north flank is highly permeable and has experienced intense hydrothermal alteration.

  14. A degassing instrument for analysing CO2 dissolved in natural water

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    Durham, Brian; Pfrang, Christian

    2017-04-01

    Arising from our EGU 2017 presentation (http://meetingorganizer.copernicus.org/EGU2016/posters/20564, X2 352), interest has been expressed in its application to the analysis of the hydrocarbonate ion [HCO3-] in atmospheric water. Arising from the historic difficulty in analysing the aqueous [HCO3-] ion ('it is in all our reagents', pers. comm. UK laboratory) the classic determination has been to measure a suite of other anions and cations including [H+] via pH, and to treat the balance of negative charge as a measure of [HCO3-]. From this balance, dissolved CO2 can be inferred via the dissociation constant as published for pure water. CO2 + H2O ⇓♢[HCO3-] + [H+] K1 = 4.2 x 10-7 Our EGU 2016 presentation sought to determine how the ionic environment in 263 UK rain samples can influence the above equilibrium, which is work in progress. In the mean time we have received the following expression of interest from an atmospheric science advisory group. …….. is very interested in the role of H-carbonate in the ion balance of precipitation. They have had some discussions recently about the best approach to infer H-carbonate currently discussing the possibility of sending you samples from other locations for analysis. We have duly offered to use our degassing instrument to corroborate current analyses in a batch of 'blind' samples, and to provide a design for a basic degasser that water quality laboratories could evaluate in house. This paper therefore presents a circuit for degassing CO2 from water samples irrespective of whether in atmospheric equilibrium or supersaturated, including a prototype 4-way distribution and collection valve which it is hoped will make the analysis intuitive and therefore open to automation.

  15. Using titanite petrochronology to monitor CO2-degassing episodes from the Himalayas

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    Rapa, Giulia; Groppo, Chiara; Rolfo, Franco; Petrelli, Maurizio; Mosca, Pietro

    2017-04-01

    Metamorphic degassing from active collisional orogens supplies a significant fraction of CO2 to the atmosphere, playing a fundamental role in the long-term (> 1 Ma) global carbon cycle (Gaillardet & Galy, 2008). The petro-chronologic study of the CO2-source rocks (e.g. calc-silicate rocks) in collisional settings is therefore fundamental to understand the nature, timing, duration and magnitude of the orogenic carbon cycle. So far, the incomplete knowledge of these systems hindered a reliable quantitative modelling of metamorphic CO2 fluxes. A detailed petrological modelling of a clinopyroxene + scapolite + K-feldspar + plagioclase + biotite + zoisite ± calcite calc-silicate rock from central Nepal Himalaya allowed us to identify and fully characterize - for the first time - different metamorphic reactions that led to the simultaneous growth of titanite and production of CO2. These reactions involve biotite (rather than rutile) as the Ti-bearing reactant counterpart of titanite. The results of petrological modelling combined with Zr-in-Ttn thermometry and U-Pb geochronology suggest that in the studied sample, most titanite grains grew during two nearly continuous episodes of titanite formation: a near-peak event at 730-740°C, 10 kbar, 25.5±1.5 Ma, and a peak event at 740-765°C, 10.5 kbar, 22±3 Ma. Both episodes of titanite growth are correlated to specific CO2-producing reactions, thus allowing to constrain the timing, duration and P-T conditions of the main CO2-producing events, as well as the amounts of CO2 produced. Assuming that fluids released at a depth of ca. 30 km are able to reach the Earth's surface 10 Ma after their production, it is therefore possible to speculate on the role exerted by the Himalayan orogenesis on the climate in the past. Gaillardet J. & Galy A. (2008): Himalaya-carbon sink or source? Science, 320, 1727-1728.

  16. Shallow magmatic degassing into the hydrothermal system of Copahue, Argentina

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    Varekamp, J.; Ouimette, A.; Kreulen, R.; Delpino, D.; Bermudez, A.

    2001-05-01

    S and low water contents (0.4 - 1.5 percent). Matrix glasses have similar volatile concentrations as many plagioclase-hosted glass inclusions. The S/Cl ratio in the hydrothermal fluids is about 2, whereas the glass inclusions have S/Cl = 0.2, indicating the strong preferential degassing of sulfur.

  17. Human impact on the historical change of CO2 degassing flux in River Changjiang

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    Zhang Jing

    2007-08-01

    Full Text Available Abstract The impact of water quality changes in River Changjiang (formally known as the Yangtze River on dissolved CO2 and silicate concentrations and seasonal carbon flux in the past several decades (1960s–2000 was evaluated, based on monitoring data from hydrographic gauge. It was found that dissolved CO2 and silicate in Changjiang decreased dramatically during this decades, as opposed to a marked increase in nutrient (e.g. NO3- concentrations. Our analyses revealed that dissolved CO2 in Changjiang was over-saturated with the atmosphere CO2, and its concentration had showed a declining trend since the 1960s, despite that fluvial DIC flux had maintained stable. Analysis results also suggested that the decrease in dissolved CO2 concentration was attributed to changes on the riverine trophic level and river damming activities in the Changjiang drainage basin. Due to the economic innovation (e.g. agriculture and industry development across the Changjiang watershed, fertilizers application and river regulations have significantly altered the original state of the river. Its ecosystem and hydrological condition have been evolving toward the "lacustrine/reservoir" autotrophic type prevailing with plankton. Accordingly, average CO2 diffusing flux to the atmosphere from the river had been reduced by three-fourth from the 1960s to 1990s, with the flux value being down to 14.2 mol.m-2.yr-1 in the 1990s. For a rough estimate, approximately 15.3 Mt of carbon was degassed annually into the atmosphere from the entire Changjiang drainage basin in the 1990s.

  18. Evolution of the chemistry of Fe bearing waters during CO2 degassing

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    Geroni, J.N.; Cravotta, C.A.; Sapsford, D.J.

    2012-01-01

    The rates of Fe(II) oxidation and precipitation from groundwater are highly pH dependent. Elevated levels of dissolved CO2 can depress pH and cause difficulty in removing dissolved Fe and associated metals during treatment of ferruginous water. This paper demonstrates interdependent changes in pH, dissolved inorganic C species, and Fe(II) oxidation rates that occur as a result of the removal (degassing) of CO2 during aeration of waters discharged from abandoned coal mines. The results of field monitoring of aeration cascades at a treatment facility as well as batchwise aeration experiments conducted using net alkaline and net acidic waters in the UK are combined with geochemical modelling to demonstrate the spatial and temporal evolution of the discharge water chemistry. The aeration cascades removed approximately 67% of the dissolved CO2 initially present but varying the design did not affect the concentration of Fe(II) leaving the treatment ponds. Continued removal of the residual CO2 by mechanical aeration increased pH by as much as 2 units and resulted in large increases in the rates of Fe(II) oxidation and precipitation. Effective exsolution of CO2 led to a reduction in the required lime dose for removal of remaining Fe(II), a very important factor with regard to increasing the sustainability of treatment practices. An important ancillary finding for passive treatment is that varying the design of the cascades had little impact on the rate of CO2 removal at the flow rates measured.

  19. Monitoring of fumarole discharge and CO2 soil degassing in the Azores: contribution to volcanic surveillance and public health risk assessment

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    C. Faria

    2005-06-01

    Full Text Available Fluid geochemistry monitoring in the Azores involves the regular sampling and analysis of gas discharges from fumaroles and measurements of CO2 diffuse soil gas emissions. Main degassing areas under monitoring are associated with hydrothermal systems of active central volcanoes in S. Miguel, Terceira and Graciosa islands. Fumarole discharge analysis since 1991 show that apart from steam these gas emissions are CO2 dominated with H2S, H2, CH4 and N2 in minor amounts. Mapping of CO2 diffuse soil emissions in S. Miguel Island lead to the conclusion that some inhabited areas are located within hazard-zones. At Furnas village, inside Furnas volcano caldera, about 62% of the 896 houses are within the CO2 anomaly, 5% being in areas of moderate to high risk. At Ribeira Seca, on the north flank of Fogo volcano, few family houses were evacuated when CO2 concentrations in the air reached 8 mol%. To assess and analyse the CO2 soil flux emissions, continuous monitoring stations were installed in S. Miguel (2, Terceira and Graciosa islands. The statistical analysis of the data showed that some meteorological parameters influence the CO2 flux. The average of CO2 flux in S. Miguel stations ranges from 250 g/m2/d at Furnas volcano to 530 g/m2/d at Fogo volcano. At Terceira Island it is about 330 g/m2/d and at Graciosa 4400 g/m2/d.

  20. Degassing of CO2, SO2, and H2S associated with the 2009 eruption of Redoubt Volcano, Alaska

    Science.gov (United States)

    Werner, Cynthia; Kelly, Peter J.; Doukas, Michael; Lopez, Taryn; Pfeffer, Melissa; McGimsey, Robert; Neal, Christina

    2013-06-01

    The 2009 eruption of Redoubt Volcano, Alaska was particularly well monitored for volcanic gas emissions. We report 35 airborne measurements of CO2, SO2, and H2S emission rates that span from October 2008 to August 2010. The magmatic system degassed primarily as a closed system although minor amounts of open system degassing were observed in the 6 months prior to eruption on March 15, 2009 and over 1 year following cessation of dome extrusion. Only 14% of the total CO2 was emitted prior to eruption even though high emissions rates (between 3630 and 9020 t/d) were observed in the final 6 weeks preceding the eruption. A minor amount of the total SO2 was observed prior to eruption (4%), which was consistent with the low emission rates at that time (up to 180 t/d). The amount of the gas emitted during the explosive and dome growth period (March 15-July 1, 2009) was 59 and 66% of the total CO2 and SO2, respectively. Maximum emission rates were 33,110 t/d CO2, 16,650 t/d SO2, and 1230 t/d H2S. Post-eruptive passive degassing was responsible for 27 and 30% of the total CO2 and SO2, respectively. SO2 made up on average 92% of the total sulfur degassing throughout the eruption. Magmas were vapor saturated with a C- and S-rich volatile phase, and regardless of composition, the magmas appear to be buffered by a volatile composition with a molar CO2/SO2 ratio of ~ 2.4. Primary volatile contents calculated from degassing and erupted magma volumes range from 0.9 to 2.1 wt.% CO2 and 0.27-0.56 wt.% S; whole-rock normalized values are slightly lower (0.8-1.7 wt.% CO2 and 0.22-0.47 wt.% S) and are similar to what was calculated for the 1989-90 eruption of Redoubt. Such contents argue that primary arc magmas are rich in CO2 and S. Similar trends between volumes of estimated degassed magma and observed erupted magma during the eruptive period point to primary volatile contents of 1.25 wt.% CO2 and 0.35 wt.% S. Assuming these values, up to 30% additional unerupted magma degassed in the

  1. Preliminary assessment of the state of CO2 soil degassing on the flanks of Gede volcano (West Java, Indonesia)

    Science.gov (United States)

    Kunrat, S. L.; Schwandner, F. M.

    2013-12-01

    Gede Volcano (West Java) is part of an andesitic stratovolcano complex consisting of Pangrango in the north-west and Gede in the south-east. The last recorded eruptive activity was a phreatic subvolcanian ash eruption in 1957. Current activity is characterized by episodic swarms at 2-4 km depth, and low-temperature (~160°C) crater degassing in two distinct summit crater fumarolic areas. Hot springs occur in the saddle between the Gede and Pangrango edifice, as well as on the NE flank base. The most recent eruptive events produced pyroclastic material, their flow deposits concentrate toward the NE. A collaborative effort between the Center for Volcanology and Geological Hazard Mitigation (CVGHM), Geological Agency and the Earth Observatory of Singapore (EOS) is since 2010 aimed at upgrading the geophysical and geochemical monitoring network at Gede Volcano. To support the monitoring instrumentation upgrades under way, surveys of soil CO2 degassing have been performed on the flanks of Gede, in circular and radial traverses.The goal was to establish a spatial distribution of flank CO2 fluxes, and to allow smart siting for continuous gas monitoring stations. Crater fluxes were not surveyed, as its low-temperature hydrothermal system is likely prone to large hydraulic changes in this tropical environment, resulting in variable permeability effects that might mask signals from deeper reservoir or conduit degassing. The high precipitation intensity in the mountains of tropical Java pose challenges to this method, since soil gas permeability is largely controlled by soil moisture content. Simultaneous soil moisture measurements were undertaken. The soil CO2 surveys were carried out using a LI-8100A campaign flux chamber instrument (LICOR Biosciences, Lincoln, Nebraska). This instrument has a very precise and highly stable sensor and an atmospheric pressure equilibrator, making it highly sensitive to low fluxes. It is the far superior choice for higher precision low

  2. Experimental evidence for carbonate precipitation and CO 2 degassing during sea ice formation

    Science.gov (United States)

    Papadimitriou, S.; Kennedy, H.; Kattner, G.; Dieckmann, G. S.; Thomas, D. N.

    2004-04-01

    -chemical processes are considered, we expect CO 2 degassing and carbonate mineral precipitation from the brine inclusions of the ice sheet, which were saturated or highly supersaturated with respect to both the anhydrous (calcite, aragonite, vaterite) and hydrated (ikaite) carbonate minerals.

  3. Degassing of CO2, SO2, and H2S associated with the 2009 eruption of Redoubt Volcano, Alaska

    Science.gov (United States)

    Werner, Cynthia A.; Kelly, Peter; Doukas, Michael P.; Lopez, Taryn; Pfeffer, Melissa; McGimsey, Robert G.; Neal, Christina

    2013-01-01

    The 2009 eruption of Redoubt Volcano, Alaska was particularly well monitored for volcanic gas emissions. We report 35 airborne measurements of CO2, SO2, and H2S emission rates that span from October 2008 to August 2010. The magmatic system degassed primarily as a closed system although minor amounts of open system degassing were observed in the 6 months prior to eruption on March 15, 2009 and over 1 year following cessation of dome extrusion. Only 14% of the total CO2 was emitted prior to eruption even though high emissions rates (between 3630 and 9020 t/d) were observed in the final 6 weeks preceding the eruption. A minor amount of the total SO2 was observed prior to eruption (4%), which was consistent with the low emission rates at that time (up to 180 t/d). The amount of the gas emitted during the explosive and dome growth period (March 15–July 1, 2009) was 59 and 66% of the total CO2and SO2, respectively. Maximum emission rates were 33,110 t/d CO2, 16,650 t/d SO2, and 1230 t/d H2S. Post-eruptive passive degassing was responsible for 27 and 30% of the total CO2 and SO2, respectively. SO2 made up on average 92% of the total sulfur degassing throughout the eruption. Magmas were vapor saturated with a C- and S-rich volatile phase, and regardless of composition, the magmas appear to be buffered by a volatile composition with a molar CO2/SO2 ratio of ~ 2.4. Primary volatile contents calculated from degassing and erupted magma volumes range from 0.9 to 2.1 wt.% CO2 and 0.27–0.56 wt.% S; whole-rock normalized values are slightly lower (0.8–1.7 wt.% CO2 and 0.22–0.47 wt.% S) and are similar to what was calculated for the 1989–90 eruption of Redoubt. Such contents argue that primary arc magmas are rich in CO2 and S. Similar trends between volumes of estimated degassed magma and observed erupted magma during the eruptive period point to primary volatile contents of 1.25 wt.% CO2 and 0.35 wt.% S. Assuming these values, up to 30% additional

  4. Conditions for oceans on Earth-like planets orbiting within the habitable zone: importance of volcanic CO2 degassing

    International Nuclear Information System (INIS)

    Kadoya, S.; Tajika, E.

    2014-01-01

    Earth-like planets in the habitable zone (HZ) have been considered to have warm climates and liquid water on their surfaces if the carbonate-silicate geochemical cycle is working as on Earth. However, it is known that even the present Earth may be globally ice-covered when the rate of CO 2 degassing via volcanism becomes low. Here we discuss the climates of Earth-like planets in which the carbonate-silicate geochemical cycle is working, with focusing particularly on insolation and the CO 2 degassing rate. The climate of Earth-like planets within the HZ can be classified into three climate modes (hot, warm, and snowball climate modes). We found that the conditions for the existence of liquid water should be largely restricted even when the planet is orbiting within the HZ and the carbonate-silicate geochemical cycle is working. We show that these conditions should depend strongly on the rate of CO 2 degassing via volcanism. It is, therefore, suggested that thermal evolution of the planetary interiors will be a controlling factor for Earth-like planets to have liquid water on their surface.

  5. First volcanic CO2 budget estimate for three actively degassing volcanoes in the Central American Volcanic Arc

    Science.gov (United States)

    Robidoux, Philippe; Aiuppa, Alessandro; Conde, Vladimir; Galle, Bo; Giudice, Gaetano; Avard, Geoffroy; Muñoz, Angélica

    2014-05-01

    CO2 is a key chemical tracer for exploring volcanic degassing mechanisms of basaltic magmatic systems (1). The rate of CO2 release from sub-aerial volcanism is monitored via studies on volcanic plumes and fumaroles, but information is still sparse and incomplete for many regions of the globe, including the majority of the volcanoes in the Central American Volcanic Arc (2). Here, we use a combination of remote sensing techniques and in-situ measurements of volcanic gas plumes to provide a first estimate of the CO2 output from three degassing volcanoes in Central America: Turrialba, in Costa Rica, and Telica and San Cristobal, in Nicaragua. During a field campaign in March-April 2013, we obtained (for the three volcanoes) a simultaneous record of SO2 fluxes (from the NOVAC network (3)) and CO2 vs. SO2 concentrations in the near-vent plumes (obtained via a temporary installed fully-automated Multi-GAS instrument (4)). The Multi-GAS time-series allowed to calculate the plume CO2/SO2 ratios for different intervals of time, showing relatively stable gas compositions. Distinct CO2 - SO2 - H2O proportions were observed at the three volcanoes, but still within the range of volcanic arc gas (5). The CO2/SO2 ratios were then multiplied by the SO2 flux in order to derive the CO2 output. At Turrialba, CO2/SO2 ratios fluctuated, between March 12 and 19, between 1.1 and 5.7, and the CO2flux was evaluated at ~1000-1350 t/d (6). At Telica, between March 23 and April 8, a somewhat higher CO2/SO2 ratio was observed (3.3 ± 1.0), although the CO2 flux was evaluated at only ~100-500 t/d (6). At San Cristobal, where observations were taken between April 11 and 15, the CO2/SO2 ratio ranged between 1.8 and 7.4, with a mean CO2 flux of 753 t/d. These measurements contribute refining the current estimates of the total CO2 output from the Central American Volcanic Arc (7). Symonds, R.B. et al., (2001). J. Volcanol. Geotherm. Res., 108, 303-341 Burton, M. R. et al. (2013). Reviews in

  6. Diffuse CO2 degassing monitoring for the volcanic surveillance of Tenerife North-East Rift Zone (NERZ) volcano, Canary Islands

    Science.gov (United States)

    Rodríguez, F.; Thomas, G. E.; Wong, T.; García, E.; Melián, G.; Padron, E.; Asensio-Ramos, M.; Hernández, P. A.; Perez, N. M.

    2017-12-01

    The North East Rift zone of Tenerife Island (NERZ, 210 km2) is one of the three major volcanic rift-zones of the island. The most recent eruptive activity along the NERZ took place in the 1704-1705 period with eruptions of Siete Fuentes, Fasnia and Arafo volcanoes. Since fumarolic activity is nowadays absent at the NERZ, soil CO2 degassing monitoring represent a potential geochemical tool for its volcanic surveillance. The aim of this study is to report the results of the last CO2 efflux survey performed in June 2017, with 658 sampling sites. In-situ measurements of CO2 efflux from the surface environment of the NERZ were performed by means of a portable non-dispersive infrared spectrophotometer (NDIR) following the accumulation chamber method. To quantify the total CO2 emission, soil CO2 efflux spatial distribution maps were constructed using Sequential Gaussian Simulation (SGS) as interpolation method. The diffuse CO2 emission values ranged between 0 - 41.1 g m-2 d-1. The probability plot technique applied to the data allowed to distinguish two different geochemical populations; background (B) and peak (P) represented by 81.8% and 18.2% of the total data, respectively, with geometric means of 3.9 and 15.0 g m-2 d-1, respectively. The average map constructed with 100 equiprobable simulations showed an emission rate of 1,361±35 t d-1. This value relatively higher than the background average of CO2 emission estimated on 415 t d-1 and slightly higher than the background range of 148 t d-1 (-1σ) and 1,189 t d-1 (+1σ) observed at the NERZ. This study reinforces the importance of performing soil CO2 efflux surveys as an effective surveillance volcanic tool in the NERZ.

  7. Enhance performance of micro direct methanol fuel cell by in situ CO2 removal using novel anode flow field with superhydrophobic degassing channels

    Science.gov (United States)

    Liang, Junsheng; Luo, Ying; Zheng, Sheng; Wang, Dazhi

    2017-05-01

    Capillary blocking caused by CO2 bubbles in anode flow field (AFF) is one of the bottlenecks for performance improvement of a micro direct methanol fuel cell (μDMFC). In this work, we present a novel AFF structure with nested layout of hydrophilic fuel channels and superhydrophobic degassing channels which can remove most of CO2 from AFF before it is released to the fuel channels. The new AFFs are fabricated on Ti substrates by using micro photochemical etching combined with anodization and fluorination treatments. Performance of the μDMFCs with and without superhydrophobic degassing channels in their AFF is comparatively studied. Results show that the superhydrophobic degassing channels can significantly speed up the exhaust of CO2 from the AFF. CO2 clogging is not observed in the new AFFs even when their comparison AFFs have been seriously blocked by CO2 slugs under the same operating conditions. 55% and 60% of total CO2 produced in μDMFCs with N-serpentine and N-spiral AFF can be respectively removed by the superhydrophobic degassing channels. The power densities of the μDMFCs equipped with new serpentine and spiral AFFs are respectively improved by 30% and 90% compared with those using conventional AFFs. This means that the new AFFs developed in this work can effectively prevent CO2-induced capillary blocking in the fuel channels, and finally significantly improve the performance of the μDMFCs.

  8. Non-volcanic CO2 Earth degassing: Case of Mefite d'Ansanto (southern Apennines), Italy

    Science.gov (United States)

    Chiodini, G.; Granieri, D.; Avino, R.; Caliro, S.; Costa, A.; Minopoli, C.; Vilardo, G.

    2010-06-01

    Mefite d'Ansanto, southern Apennines, Italy is the largest natural emission of low temperature CO2 rich gases, from non-volcanic environment, ever measured in the Earth. The emission is fed by a buried reservoir, made up of permeable limestones and covered by clayey sediments. We estimated a total gas flux of ˜2000 tons per day. Under low wind conditions, the gas flows along a narrow natural channel producing a persistent gas river which has killed over a period of time people and animals. The application of a physical numerical model allowed us to define the zones which potentially can be affected by dangerous CO2 concentration at breathing height for humans. The geometry of the Mefite gas reservoir is similar to those designed for sequestering CO2 in geological storage projects where huge amounts of CO2 should be injected in order to reduce atmospheric CO2 concentration. The approach which we have used at Mefite to define hazardous zones for the human health can be applied also in case of large CO2 leakages from storage sites, a phenomena which, even if improbable, can not be ruled out.

  9. The Effects of Varying Crustal Carbonate Composition on Assimilation and CO2 Degassing at Arc Volcanoes

    Science.gov (United States)

    Carter, L. B.; Holmes, A. K.; Dasgupta, R.; Tumiati, S.

    2015-12-01

    Magma-crustal carbonate interaction and subsequent decarbonation can provide an additional source of CO2 release to the exogenic system superimposed on mantle-derived CO2. Carbonate assimilation at present day volcanoes is often modeled by limestone consumption experiments [1-4]. Eruptive products, however, do not clearly display the characteristic ultracalcic melt compositions produced during limestone-magma interaction [4]. Yet estimated CO2outflux [5] and composition of volcanics in many volcanic systems may allow ~3-17% limestone- or dolostone-assimilated melt contribution. Crystallization may retain ultracalcic melts in pyroxenite cumulates. To extend our completed study on limestone assimilation, here we explore the effect of varying composition from calcite to dolomite on chemical and thermal decarbonation efficiency of crustal carbonates. Piston cylinder experiments at 0.5 GPa and 900-1200 °C demonstrate that residual mineralogy during interaction with magma shifts from CaTs cpx and anorthite/scapolite in the presence of calcite to Di cpx and Fo-rich olivine with dolomite. Silica-undersaturated melts double in magnesium content, while maintaining high (>30 wt.%) CaO values. At high-T, partial thermal breakdown of dolomite into periclase and CO2 is minimal (<5%) suggesting that in the presence of magma, CO2 is primarily released due to assimilation. Assimilated melts at identical P-T conditions depict similarly high volatile contents (10-20 wt.% by EMPA deficit at 0.5 GPa, 1150 °C with hydrous basalt) with calcite or dolomite. Analysis of the coexisting fluid phase indicates the majority of water is dissolved in the melt, while CO2 released from the carbonate is preferentially partitioned into the vapor. This suggests that although assimilated melts have a higher CO2 solubility, most of the CO2can easily degas from the vapor phase at arc volcanoes, possibly more so at volcanic plumbing systems traversing dolomite [8]. [1]Conte et al 2009 EuJMin (21) 763

  10. Surface heat flow and CO2 emissions within the Ohaaki hydrothermal field, Taupo Volcanic Zone, New Zealand

    Science.gov (United States)

    Rissmann, C.; Christenson, B.; Werner, C.; Leybourne, M.; Cole, J.; Gravley, D.

    2012-01-01

    Carbon dioxide emissions and heat flow have been determined from the Ohaaki hydrothermal field, Taupo Volcanic Zone (TVZ), New Zealand following 20a of production (116MW e). Soil CO2 degassing was quantified with 2663 CO2 flux measurements using the accumulation chamber method, and 2563 soil temperatures were measured and converted to equivalent heat flow (Wm -2) using published soil temperature heat flow functions. Both CO2 flux and heat flow were analysed statistically and then modelled using 500 sequential Gaussian simulations. Forty subsoil CO 2 gas samples were also analysed for stable C isotopes. Following 20a of production, current CO2 emissions equated to 111??6.7T/d. Observed heat flow was 70??6.4MW, compared with a pre-production value of 122MW. This 52MW reduction in surface heat flow is due to production-induced drying up of all alkali-Cl outflows (61.5MW) and steam-heated pools (8.6MW) within the Ohaaki West thermal area (OHW). The drying up of all alkali-Cl outflows at Ohaaki means that the soil zone is now the major natural pathway of heat release from the high-temperature reservoir. On the other hand, a net gain in thermal ground heat flow of 18MW (from 25MW to 43.3??5MW) at OHW is associated with permeability increases resulting from surface unit fracturing by production-induced ground subsidence. The Ohaaki East (OHE) thermal area showed no change in distribution of shallow and deep soil temperature contours despite 20a of production, with an observed heat flow of 26.7??3MW and a CO 2 emission rate of 39??3T/d. The negligible change in the thermal status of the OHE thermal area is attributed to the low permeability of the reservoir beneath this area, which has limited production (mass extraction) and sheltered the area from the pressure decline within the main reservoir. Chemistry suggests that although alkali-Cl outflows once contributed significantly to the natural surface heat flow (~50%) they contributed little (99% of the original CO 2

  11. Diffuse degassing He/CO2 ratio before and during the 2011-12 El Hierro submarine eruption, Canary Islands

    Science.gov (United States)

    Padrón, Eleazar; Hernández, Pedro A.; Melián, Gladys V.; Barrancos, José; Padilla, Germán; Pérez, Nemesio M.; Dionis, Samara; Rodríguez, Fátima; Asensio-Ramos, María; Calvo, David

    2015-04-01

    El Hierro Island (278 km2) is the youngest and the SW-most of the Canary Islands. On July 16, 2011, a seismic-volcanic crisis started with the occurrence of more than 11,900 seismic events and significant deformation along the island, culminating with the eruption onset in October 12. Since at El Hierro Islands there are not any surface geothermal manifestation (fumaroles, etc), we have focused our studies on soil degassing surveys. Between July 2011 to March 2012, seventeen diffuse CO2 and He emissions soil gas surveys were undertaken at El Hierro volcanic system (600 observation sites) with the aim to investigate the relationship between their temporal variations and the volcanic activity (Padrón et al., 2013; Melián et al., 2014). Based on the diffuse He/CO2 emission ratio, a sharp increase before the eruption onset was observed, reaching the maximum value on September 26 (6.8×10-5), sixteen days before the occurrence of the eruption. This increase coincided with an increase in seismic energy release during the volcanic unrest and occurred together with an increase on the 3He/4He isotopic ratio in groundwaters from a well in El Hierro Island (Padrón et al., 2013; from 2-3 RA to 7.2 RA where RA = 3He/4He ratio in air), one month prior to the eruption onset. Early degassing of new gas-rich magma batch at depth could explain the observed increase on the He/CO2 ratio, causing a preferential partitioning of CO2 in the gas phase with respect to the He, due to the lower solubility of CO2 than that of He in basaltic magmas. During the eruptive period (October 2011-March 2012) the prevalence of a magmatic CO2-dominated component is evident, as indicated by the generally lower He/CO2 ratios and high 3He/4He values (Padrón et al., 2013). The onset of the submarine eruption might have produced a sudden release of volcanic gases, and consequently, a decrease in the volcanic gas pressure of the magma bodies moving beneath the island, reflected by a drastic decrease in

  12. Hydrothermal activity and subsoil complexity: implication for degassing processes at Solfatara crater, Campi Flegrei caldera

    Science.gov (United States)

    Montanaro, Cristian; Mayer, Klaus; Isaia, Roberto; Gresse, Marceau; Scheu, Bettina; Yilmaz, Tim I.; Vandemeulebrouck, Jean; Ricci, Tullio; Dingwell, Donald B.

    2017-12-01

    The Solfatara area and its fumaroles are the main surface expression of the vigorous hydrothermal activity within the active Campi Flegrei caldera system. At depth, a range of volcanic and structural processes dictate the actual state of the hydrothermal system below the crater. The presence of a large variety of volcanic products at shallow depth (including pyroclastic fallout ash beds, pyroclastic density current deposits, breccias, and lavas), and the existence of a maar-related fault system appears to exert major controls on the degassing and alteration behavior. Adding further to the complexity of this environment, variations in permeability and porosity, due to subsoil lithology and alteration effects, may further influence fluid flow towards the surface. Here, we report results from a field campaign conducted in July 2015 that was designed to characterize the in situ physical (temperature, humidity) and mechanical (permeability, strength, stiffness) properties of the Solfatara crater subsoil. The survey also included a mapping of the surficial hydrothermal features and their distributions. Finally, laboratory measurements (porosity, granulometry) of selected samples were performed. Our results enable the discrimination of four main subsoils around the crater: (1) the Fangaia domain located in a topographic low in the southwestern sector, (2) the silica flat domain on the western altered side, (3) the new crust domain in the central area, and (4) the crusted hummocks domain that dominates the north, east, and south parts. These domains are surrounded by encrusted areas, reworked material, and vegetated soil. The distribution of these heterogeneous subsoils suggests that their formation is mostly related to (i) the presence of the Fangaia domain within the crater and (ii) a system of ring faults bordering it. The subsoils show an alternation between very high and very low permeabilities, a fact which seems to affect both the temperature distribution and

  13. The Evidence from Inclusions in Pumices for the Direct Degassing of Volatiles from the Magma to the Hydrothermal Fluids in the Okinawa Trough

    Institute of Scientific and Technical Information of China (English)

    YU Zenghui; ZHAI Shikui; ZHAO Guangtao

    2002-01-01

    This article presents the evidence in support of the direct magma degassing as the principal mechanism of volatilesreleasing into the hydrothermal fluids in the Okinawa Trough, as contrasted to the argument for the hydrothermal strippingof volatiles from the volcanic rocks.Laser Raman microprobe and stepped-heating techniques are employed to determine the compositions and contents of thevolatiles in pumices in the middle Okinawa Trough. The results show that the volatiles are similar to the gases in the hy-drothermal fluids and hydrothermal minerals in composition, the mean percent content of each component and variationtrend. This indicates the direct influence of magma degassing on the hydrothermal fluids. In addition, the contents ofvolatiles in pumices are rather low and do not support the hydrothermal stripping as the main mechanism to enrich the fluidswith gases. The results are consistent with the idea that the direct magma degassing is more important than hydrothermalstripping in supplying gases to the hydrothermal fluids in the Okinawa Trough.

  14. Significant discharge of CO2 from hydrothermalism associated with the submarine volcano of El Hierro Island

    Science.gov (United States)

    Santana-Casiano, J. M.; Fraile-Nuez, E.; González-Dávila, M.; Baker, E. T.; Resing, J. A.; Walker, S. L.

    2016-05-01

    The residual hydrothermalism associated with submarine volcanoes, following an eruption event, plays an important role in the supply of CO2 to the ocean. The emitted CO2 increases the acidity of seawater. The submarine volcano of El Hierro, in its degasification stage, provided an excellent opportunity to study the effect of volcanic CO2 on the seawater carbonate system, the global carbon flux, and local ocean acidification. A detailed survey of the volcanic edifice was carried out using seven CTD-pH-ORP tow-yo studies, localizing the redox and acidic changes, which were used to obtain surface maps of anomalies. In order to investigate the temporal variability of the system, two CTD-pH-ORP yo-yo studies were conducted that included discrete sampling for carbonate system parameters. Meridional tow-yos were used to calculate the amount of volcanic CO2 added to the water column for each surveyed section. The inputs of CO2 along multiple sections combined with measurements of oceanic currents produced an estimated volcanic CO2 flux = 6.0 105 ± 1.1 105 kg d-1 which is ~0.1% of global volcanic CO2 flux. Finally, the CO2 emitted by El Hierro increases the acidity above the volcano by ~20%.

  15. Geophysical Images of the Shallow Hydrothermal Degassing at Solfatara (Phlegrean Fields, Italy)

    Science.gov (United States)

    Byrdina, S.; Vandemeulebrouck, J.; Cardellini, C.; Chiodini, G.; Legaz, A.; Camerlynck, C.; Lebourg, T.

    2014-12-01

    We present the results of an electric resistivity tomography (ERT) survey, combined with mappings of diffuse carbon dioxide flux, ground temperature and self-potential (SP) at Solfatara, the most active crater of Phlegrean Fields. Solfatara is characterized by an intense carbon dioxide degassing, fumarole activity, and ground deformation. This ensemble of methods is applied to image the hydrothermal system of Solfatara, to understand the geometry of the fluid circulation, and to define the extension of the hydrothermal plume at a high enough resolution for a quantitative modeling. ERT inversion results show Solfatara as a globally conductive structure, with resistivity in the range 1-200 Ohmm. Broad negative anomaly of self-potential in the inner part of Solfatara with a minimum in the area of Bocca Grande suggests a significant downward flow of condensing liquid water. Comparison between spatial variations of resistivity and gas flux indicates that resistivity changes at depth are related to gas saturation and fluid temperature. These variations delineate two plume structures: a liquid-dominated conductive plume below Fangaia mud-pool and a gas-dominated plume below Bocca Grande fumarole. The geometry of the Fangaia liquid-saturated plume is also imaged by a high resolution 3-D resistivity model. In order to estimate the permeability, we propose a 2-D axis-symmetric numerical model coupling Richards's equation for fluid flow in conditions of partial saturation with the resistivity calculation as function of saturation only. Alternatively, we apply the Dupuit equation to estimate the permeability of the shallow layer. Using these two approaches, we obtain the permeability of the shallow layer below Fangaia which ranges between (2 - 4) 10-14 m 2.

  16. Hydrothermal stability of adenine under controlled fugacities of N2, CO2 and H2.

    Science.gov (United States)

    Franiatte, Michael; Richard, Laurent; Elie, Marcel; Nguyen-Trung, Chinh; Perfetti, Erwan; LaRowe, Douglas E

    2008-04-01

    An experimental study has been carried out on the stability of adenine (one of the five nucleic acid bases) under hydrothermal conditions. The experiments were performed in sealed autoclaves at 300 degrees C under fugacities of CO(2), N(2) and H(2) supposedly representative of those in marine hydrothermal systems on the early Earth. The composition of the gas phase was obtained from the degradation of oxalic acid, sodium nitrite and ammonium chloride, and the oxidation of metallic iron. The results of the experiments indicate that after 200 h, adenine is still present in detectable concentration in the aqueous phase. In fact, the concentration of adenine does not seem to be decreasing after approximately 24 h, which suggests that an equilibrium state may have been established with the inorganic constituents of the hydrothermal fluid. Such a conclusion is corroborated by independent thermodynamic calculations.

  17. Electrochemical CO2 Reduction by Ni-containing Iron Sulfides: How Is CO2 Electrochemically Reduced at Bisulfide-Bearing Deep-sea Hydrothermal Precipitates?

    International Nuclear Information System (INIS)

    Yamaguchi, Akira; Yamamoto, Masahiro; Takai, Ken; Ishii, Takumi; Hashimoto, Kazuhito; Nakamura, Ryuhei

    2014-01-01

    The discovery of deep-sea hydrothermal vents on the late 1970's has led to many hypotheses concerning chemical evolution in the prebiotic ocean and the early evolution of energy metabolism in ancient Earth. Such studies stand on the quest for the bioenergetic evolution to utilize reducing chemicals such as H 2 for CO 2 reduction and carbon assimilation. In addition to the direct reaction of H 2 and CO 2 , the electrical current passing across a bisulfide-bearing chimney structure has pointed to the possible electrocatalytic CO 2 reduction at the cold ocean-vent interface (R. Nakamura, et al. Angew. Chem. Int. Ed. 2010, 49, 7692 − 7694). To confirm the validity of this hypothesis, here, we examined the energetics of electrocatalytic CO 2 reduction by iron sulfide (FeS) deposits at slightly acidic pH. Although FeS deposits inefficiently reduced CO 2 , the efficiency of the reaction was substantially improved by the substitution of Fe with Ni to form FeNi 2 S 4 (violarite), of which surface was further modified with amine compounds. The potential-dependent activity of CO 2 reduction demonstrated that CO 2 reduction by H 2 in hydrothermal fluids was involved in a strong endergonic electron transfer reaction, suggesting that a naturally occurring proton-motive force (PMF) as high as 200 mV would be established across the hydrothermal vent chimney wall. However, in the chimney structures, H 2 generation competes with CO 2 reduction for electrical current, resulting in rapid consumption of the PMF. Therefore, to maintain the PMF and the electrosynthesis of organic compounds in hydrothermal vent mineral deposits, we propose a homeostatic pH regulation mechanism of FeS deposits, in which elemental hydrogen stored in the hydrothermal mineral deposits is used to balance the consumption of the electrochemical gradient by H 2 generation

  18. Surface heat flow and CO2 emissions within the Ohaaki hydrothermal field, Taupo Volcanic Zone, New Zealand

    International Nuclear Information System (INIS)

    Rissmann, Clinton; Christenson, Bruce; Werner, Cynthia; Leybourne, Matthew; Cole, Jim; Gravley, Darren

    2012-01-01

    Carbon dioxide emissions and heat flow have been determined from the Ohaaki hydrothermal field, Taupo Volcanic Zone (TVZ), New Zealand following 20 a of production (116 MW e ). Soil CO 2 degassing was quantified with 2663 CO 2 flux measurements using the accumulation chamber method, and 2563 soil temperatures were measured and converted to equivalent heat flow (W m −2 ) using published soil temperature heat flow functions. Both CO 2 flux and heat flow were analysed statistically and then modelled using 500 sequential Gaussian simulations. Forty subsoil CO 2 gas samples were also analysed for stable C isotopes. Following 20 a of production, current CO 2 emissions equated to 111 ± 6.7 T/d. Observed heat flow was 70 ± 6.4 MW, compared with a pre-production value of 122 MW. This 52 MW reduction in surface heat flow is due to production-induced drying up of all alkali–Cl outflows (61.5 MW) and steam-heated pools (8.6 MW) within the Ohaaki West thermal area (OHW). The drying up of all alkali–Cl outflows at Ohaaki means that the soil zone is now the major natural pathway of heat release from the high-temperature reservoir. On the other hand, a net gain in thermal ground heat flow of 18 MW (from 25 MW to 43.3 ± 5 MW) at OHW is associated with permeability increases resulting from surface unit fracturing by production-induced ground subsidence. The Ohaaki East (OHE) thermal area showed no change in distribution of shallow and deep soil temperature contours despite 20 a of production, with an observed heat flow of 26.7 ± 3 MW and a CO 2 emission rate of 39 ± 3 T/d. The negligible change in the thermal status of the OHE thermal area is attributed to the low permeability of the reservoir beneath this area, which has limited production (mass extraction) and sheltered the area from the pressure decline within the main reservoir. Chemistry suggests that although alkali–Cl outflows once contributed significantly to the natural surface heat flow (∼50%) they

  19. The pH and pCO2 dependence of sulfate reduction in shallow-sea hydrothermal CO2 – venting sediments (Milos Island, Greece)

    Science.gov (United States)

    Bayraktarov, Elisa; Price, Roy E.; Ferdelman, Timothy G.; Finster, Kai

    2013-01-01

    Microbial sulfate reduction (SR) is a dominant process of organic matter mineralization in sulfate-rich anoxic environments at neutral pH. Recent studies have demonstrated SR in low pH environments, but investigations on the microbial activity at variable pH and CO2 partial pressure are still lacking. In this study, the effect of pH and pCO2 on microbial activity was investigated by incubation experiments with radioactive 35S targeting SR in sediments from the shallow-sea hydrothermal vent system of Milos, Greece, where pH is naturally decreased by CO2 release. Sediments differed in their physicochemical characteristics with distance from the main site of fluid discharge. Adjacent to the vent site (T ~40–75°C, pH ~5), maximal sulfate reduction rates (SRR) were observed between pH 5 and 6. SR in hydrothermally influenced sediments decreased at neutral pH. Sediments unaffected by hydrothermal venting (T ~26°C, pH ~8) expressed the highest SRR between pH 6 and 7. Further experiments investigating the effect of pCO2 on SR revealed a steep decrease in activity when the partial pressure increased from 2 to 3 bar. Findings suggest that sulfate reducing microbial communities associated with hydrothermal vent system are adapted to low pH and high CO2, while communities at control sites required a higher pH for optimal activity. PMID:23658555

  20. The pH and pCO2 dependence of sulfate reduction in shallow-sea hydrothermal CO2 - venting sediments (Milos Island, Greece).

    Science.gov (United States)

    Bayraktarov, Elisa; Price, Roy E; Ferdelman, Timothy G; Finster, Kai

    2013-01-01

    Microbial sulfate reduction (SR) is a dominant process of organic matter mineralization in sulfate-rich anoxic environments at neutral pH. Recent studies have demonstrated SR in low pH environments, but investigations on the microbial activity at variable pH and CO2 partial pressure are still lacking. In this study, the effect of pH and pCO2 on microbial activity was investigated by incubation experiments with radioactive (35)S targeting SR in sediments from the shallow-sea hydrothermal vent system of Milos, Greece, where pH is naturally decreased by CO2 release. Sediments differed in their physicochemical characteristics with distance from the main site of fluid discharge. Adjacent to the vent site (T ~40-75°C, pH ~5), maximal sulfate reduction rates (SRR) were observed between pH 5 and 6. SR in hydrothermally influenced sediments decreased at neutral pH. Sediments unaffected by hydrothermal venting (T ~26°C, pH ~8) expressed the highest SRR between pH 6 and 7. Further experiments investigating the effect of pCO2 on SR revealed a steep decrease in activity when the partial pressure increased from 2 to 3 bar. Findings suggest that sulfate reducing microbial communities associated with hydrothermal vent system are adapted to low pH and high CO2, while communities at control sites required a higher pH for optimal activity.

  1. Environmental impact of CO2, Rn, Hg degassing from the rupture zones produced by Wenchuan M s 8.0 earthquake in western Sichuan, China.

    Science.gov (United States)

    Zhou, Xiaocheng; Chen, Zhi; Cui, Yueju

    2016-10-01

    The concentrations and flux of CO2, (222)Radon (Rn), and gaseous elemental mercury (Hg) in soil gas were investigated based on the field measurements in June 2010 at ten sites along the seismic rupture zones produced by the May 12, 2008, Wenchuan M s 8.0 earthquake in order to assess the environmental impact of degassing of CO2, Rn and Hg. Soil gas concentrations of 344 sampling points were obtained. Seventy measurements of CO2, Rn and Hg flux by the static accumulation chamber method were performed. The results of risk assessment of CO2, Rn and Hg concentration in soil gas showed that (1) the concentration of CO2 in the epicenter of Wenchuan M s 8.0 earthquake and north end of seismic ruptures had low risk of asphyxia; (2) the concentrations of Rn in the north segment of seismic ruptures had high levels of radon, Maximum was up to level 4, according to Chinese code (GB 50325-2001); (3) the average geoaccumulation index I geo of soil Hg denoted the lack of soil contamination, and maximum values classified the soil gas as moderately to strongly polluted in the epicenter. The investigation of soil gas CO2, Rn and Hg degassing rate indicated that (1) the CO2 in soil gas was characterized by a mean [Formula: see text] of -20.4 ‰ and by a mean CO2 flux of 88.1 g m(-2) day(-1), which were in the range of the typical values for biologic CO2 degassing. The maximum of soil CO2 flux reached values of 399 g m(-2) day(-1) in the epicenter; (2) the soil Rn had higher exhalation in the north segment of seismic ruptures, the maximum reached value of 1976 m Bq m(-2) s(-1); (3) the soil Hg flux was lower, ranging from -2.5 to 18.7 n g m(-2) h(-1) and increased from south to north. The mean flux over the all profiles was 4.2 n g m(-2) h(-1). The total output of CO2 and Hg degassing estimated along seismic ruptures for a survey area of 18.17 km(2) were approximately 0.57 Mt year(-1) and 688.19 g year(-1). It is recommended that land-use planners should

  2. CO2 degassing in the Hartoušov mofette area, western Eger Rift, imaged by CO2 mapping and geoelectrical and gravity surveys

    Czech Academy of Sciences Publication Activity Database

    Nickschick, T.; Kämpf, H.; Flechsig, C.; Mrlina, Jan; Heinicke, J.

    2015-01-01

    Roč. 104, č. 8 (2015), s. 2107-2129 ISSN 1437-3254 R&D Projects: GA MŠk LM2010008 Institutional support: RVO:67985530 Keywords : Eger Rift * Cheb Basin * magmatic CO2 * CO2 gas flux studies * geoelectrics * gravity Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.133, year: 2015

  3. Insights into the Hydrothermal Stability of Triamine-Functionalized SBA-15 Silica for CO2 Adsorption.

    Science.gov (United States)

    Jahandar Lashaki, Masoud; Ziaei-Azad, Hessam; Sayari, Abdelhamid

    2017-10-23

    The hydrothermal stability of triamine-grafted, large-pore SBA-15 CO 2 adsorbents was studied by using steam stripping. Following two 3 h cycles of steam regeneration, lower CO 2 uptakes, lower CO 2 /N ratios, and slower adsorption kinetics were observed relative to fresh samples, particularly at the lowest adsorption temperature (25 °C). CO 2 adsorption measurements for a selected sample exposed to 48 h of steam stripping depicted that after the initial loss during the first exposure to steam (3-6 h), the adsorptive properties stabilized. For higher adsorption temperatures (i.e., 50 and 75 °C), however, all adsorptive properties remained almost unchanged after steaming, indicating the significance of diffusional limitations. Thermogravimetric analysis and FTIR spectroscopy on grafted samples before and after steam stripping showed no amine leaching and no change in the chemical nature of the amine groups, respectively. Also, a six-cycle CO 2 adsorption/desorption experiment under dry conditions showed no thermal degradation. However, N 2 adsorption measurement at 77 K showed significant reductions in the BET surface area of the grafted samples following steaming. Based on the pore size distribution of calcined, grafted samples before and after steaming, it is proposed that exposure to steam restructured the grafted materials, causing mass transfer resistance. It is inferred that triamine-grafted, large-pore SBA-15 adsorbents are potential candidates for CO 2 capture at relatively high temperatures (50-75 °C; for example, flue gas) combined with steam regeneration. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Diffuse soil emission of hydrothermal gases (CO2, CH4, and C6H6) at Solfatara crater (Campi Flegrei, southern Italy)

    International Nuclear Information System (INIS)

    Tassi, F.; Nisi, B.; Cardellini, C.; Capecchiacci, F.; Donnini, M.; Vaselli, O.; Avino, R.; Chiodini, G.

    2013-01-01

    Highlights: • We present the first measurements of soil C 6 H 6 fluxes in a volcanic system. • Methane oxidation rate is controlled by soil gas fluxes. • Benzene oxidation rate is controlled by presence of a SO 4 2- rich aquifer. • Fumarolic emissions cause a strong benzene air contamination at a local scale. • Endogenous monoaromatics are detected in air samples from the whole crater. - Abstract: Measurements of soil fluxes of hydrothermal gases, with special emphasis on C 6 H 6 , as well as chemical composition of mono-aromatic compounds in fumaroles and air, were carried out in April 2012 at the Solfatara crater (Campi Flegrei, Southern Italy) to investigate the distribution and behavior of these species as they migrate through the soil from their deep source to the atmosphere. Soil fluxes of CO 2 , CH 4 and C 6 H 6 exhibit good spatial correlation, suggesting that diffuse degassing is mainly controlled by local fractures. The calculated total output of diffuse C 6 H 6 from Solfatara is 0.10 kg day −1 , whereas fluxes of CO 2 and CH 4 are 79 × 10 3 and 1.04 kg day −1 , respectively. A comparison between soil gas fluxes and fumarole composition reveals that within the crater soil CH 4 is significantly affected by oxidation processes, which are more efficient for low gas fluxes, being dependent on the residence time of the uprising hydrothermal gases at shallow depth. Benzene degradation, mainly proceeding through oxidation via benzoate, seems to be strongly controlled by the presence of a shallow SO 4 2- rich aquifer located in the central and southwestern sectors of the crater, suggesting that the process is particularly efficient when SO 4 2- acts as terminal electron acceptor (SO 4 reduction). Relatively high C 6 H 6 /C 7 H 8 ratios, typical of hydrothermal fluids, were measured in air close to the main fumarolic field of Solfatara crater. Here, C 6 H 6 concentrations, whose detection limit is ∼0.1 μg m −3 , are more than one order of

  5. New evidence of CO2 soil degassing anomalies on Piton de la Fournaise volcano and the link with volcano tectonic structures

    Science.gov (United States)

    Liuzzo, M.; Di Muro, A.; Giudice, G.; Michon, L.; Ferrazzini, V.; Gurrieri, S.

    2015-12-01

    Piton de la Fournaise (PdF) is recognized as one of the world's most active volcanoes in terms of eruptive frequency and the substantial quantity of lava produced. Yet with the sole exception of rather modest intracrateric fumarole activity, this seems to be in contrast with an apparent absence of any type of natural fluid emission during periods of quiescence. Measurement campaigns were undertaken during a long-lasting quiescent period (2012-2014) and just after a short-lived summit eruption (June 2014) in order to identify potential degassing areas in relation to the main structural features of the volcano (e.g., rift zones) with the aim of developing a broader understanding of the geometry of the plumbing and degassing system. In order to assess the possible existence of anomalous soil CO2 flux, 513 measurements were taken along transects roughly orthogonal to the known tectonic lineaments crossing PdF edifice. In addition, 53 samples of gas for C isotope analysis were taken at measurement points that showed a relatively high CO2 concentration in the soil. CO2 flux values range from 10 to 1300 g m-2 d-1 while δ13C are between -26.6 and -8‰. The results of our investigation clearly indicate that there is a strong spatial correlation between the anomalous high values of diffusive soil emissions and the main rift zones cutting the PdF massif and, moreover, that generally high soil CO2 fluxes show a δ13C signature clearly related to a magmatic origin.

  6. Evidence for degassing of fresh magma during the 2004-2008 eruption of Mount St. Helens: Subtle signals from the hydrothermal system

    Science.gov (United States)

    Bergfeld, Deborah; Evans, William C.; Spicer, Kurt R.; Hunt, Andrew G.; Kelly, Peter

    2017-01-01

    Results from chemical and isotopic analyses of water and gas collected between 2002 and 2016 from sites on and around Mount St. Helens are used to assess magmatic degassing related to the 2004-2008 eruption. During 2005 the chemistry of hot springs in The Breach of Mount St. Helens showed no obvious response to the eruption, and over the next few years, changes were subtle, giving only slight indications of perturbations in the system. By 2010 however, water chemistry, temperatures, and isotope compositions (δD and δ18O) clearly indicated some inputs of volatiles and heat associated with the eruption, but the changes were such that they could be attributed to a pre-existing, gas depleted magma. An increase of ~ 1.5‰ in the δ13C values of dissolved carbon in the springs was noted in 2006 and continued through 2009, a change that was mirrored by a similar shift in δ13C-CO2 in bubble gas emissions. These changes require input of a new source of carbon to the hydrothermal system and provide clear evidence of CO2 from an undegassed body of magma. Rising trends in 3He/4He ratios in gas also accompanied the increases in δ13C. Since 2011 maximum RC/RA values are ≥ 6.4 and are distinctly higher than 5 samples collected between 1986 and 2002, and provide additional evidence for some involvement of new magma as early as 2006, and possibly earlier, given the unknown time needed for CO2 and He to traverse the system and arrive at the springs.

  7. Bacterial and Archaeal Community Dynamics at CO2-RICH Shallow-Sea Hydrothermal Vents (panarea, Italy)

    Science.gov (United States)

    Schubotz, F.; Huang, C.; Meyerdierks, A.; Amend, J.; Price, R. E.; Amann, R.; Hinrichs, K.; Summons, R. E.

    2013-12-01

    Shallow marine hydrothermal vents are highly dynamic systems with unique habitats that can support both chemosynthetic and photosynthetic communities at steep temperature and geochemical gradients. Here, we present a combined organic geochemical and microbiological approach to describe the microbial community composition and their metabolism at the CO2-rich shallow hydrothermal vents off Panarea Island, in Sicily. We investigated two contrasting hydrothermal environments: Hot Lake, a depression filled with hydrothermal fluids diffusing gradually out of the seafloor, with temperatures ranging from 40 to 70°C, and Blackpoint, a site with vigorous venting of hydrothermal gasses and fluids with temperatures as high as 135°C. At Hot Lake, Bacteria dominate the microbial community composition in the sediments. 16S rRNA clone libraries revealed Bacteriodetes-, Epsilonproteobacteria- and Deltaproteobacteria-related sequences as the most abundant members. Bacterial intact polar membrane lipids (IPLs) were dominated by the non-phosphorous containing ornithine lipids throughout all depths, indicating an important role of this aminolipid at elevated temperatures and/or low pH. At Hot Lake, archaeal IPLs were comprised mainly of glycosidic tetraethers and increased up to 20% of total IPLs with increasing temperature and depth. At the same site, archaeal 16S rRNA clone libraries were mainly comprised of Euryarchaea-affiliated sequences; crenarchaeotal sequences were only found in deeper sediment layers with temperatures of ca. 70°C. In contrast to Hot Lake, Archaea dominated sediments at the much hotter site at Blackpoint. Here, novel methylated H-shaped archaeal tetraethers, with multiple sugars as head groups, were the most abundant membrane lipids. Reports on these lipids in cultures are very limited, but their abundant occurrence at elevated temperatures suggests an important role in membrane homeostastis in thermophilic Archaea. Stable carbon isotope values of -35‰ to

  8. Architecture and temporal variations of a terrestrial CO2 degassing site using electric resistivity tomography and selfpotential

    Czech Academy of Sciences Publication Activity Database

    Nickschick, T.; Flechsig, C.; Meinel, C.; Mrlina, Jan; Kämpf, H.

    2017-01-01

    Roč. 106, č. 8 (2017), s. 2915-2926 ISSN 1437-3254 Institutional support: RVO:67985530 Keywords : Eger rift * ERT * CO2 gax flux * Cheb Basin * mofettes Subject RIV: DC - Siesmology, Volcanology, Earth Structure OBOR OECD: Volcanology Impact factor: 2.283, year: 2016

  9. Spatial and temporal variations of diffuse CO_{2} degassing at the Tenerife North-South Rift Zone (NSRZ) volcano (Canary Islands) during the period 2002-2016

    Science.gov (United States)

    Rodríguez, Fátima; McCollum, John J. K.; Orland, Elijah D. M.; Barrancos, José; Padilla, Germán D.; Calvo, David; Amonte, Cecilia; Pérez, Nemesio M.

    2017-04-01

    Subaerial volcanic activity on Tenerife (2034 km2), the largest island of the Canary archipelago, started 14 My ago and 4 volcanic eruptions have occurred in historical times during the last 300 years. The main volcano-structural and geomorphological features of Tenerife are (i) the central volcanic complex, nowadays formed by Las Cañadas caldera, a volcanic depression measuring 16×9 km that resulted from multiple vertical collapses and partially filled by post-caldera volcanic products and (ii) the triple junction-shaped rift system, formed by numerous aligned monogenetic cones. Up to 297 mafic monogenetic cones have been recognized on Tenerife, and they represent the most common eruptive activity occurring on the island during the last 1 My (Dóniz et al., 2008). The North-South Rift Zone (NSRZ) of Tenerife comprises at least 139 cones. The main structural characteristic of the NSRZ of the island is an apparent absence of a distinct ridge, and a fan shaped distribution of monogenetic cones. Since there are currently no visible gas emissions at the NSRZ, diffuse degassing surveys have become an important geochemical tool for the surveillance of this volcanic system. Five diffuse CO2 degassing surveys have been carried out at NSRZ of Tenerife since 2002, the last one in the summer period of 2016, to evaluate the spatio-temporal variations of CO2 degassing as a volcanic surveillance tool for the NSRZ of Tenerife. At each survey, around 600 sampling sites were selected to cover homogenously the study area (325 km2) using the accumulation chamber method. The diffuse CO2 output ranged from 78 to 707 t/d in the study period, with the highest emission rate measured in 2015. The backgroung emission rate was estimated in 300 t/d. The last results the soil CO2 efflux values ranged from non-detectable up to 24.7 g m-2 d-1. The spatial distribution map, constructed following the sequential Gaussian simulation (sGs) procedure, showed the highest CO2 values as multiple

  10. The influence of episodic shallow magma degassing on heat and chemical transport in volcanic hydrothermal systems

    Science.gov (United States)

    Chen, Kewei; Zhan, Hongbin; Burns, Erick; Ingebritsen, Steven E.; Agrinier, Pierre

    2018-01-01

    Springs at La Soufrière of Guadeloupe have been monitored for nearly four decades since the phreatic eruption and associated seismic activity in 1976. We conceptualize degassing vapor/gas mixtures as square‐wave sources of chloride and heat and apply a new semianalytic solution to demonstrate that chloride and heat pulses with the same timing and duration result in good matches between measured and simulated spring temperatures and concentrations. While the concentration of chloride pulses is variable, the local boiling temperature of 96°C was assigned to all thermal pulses. Because chloride is a conservative tracer, chloride breakthrough is only affected by one‐dimensional advection and dispersion. The thermal tracer is damped and lagged relative to chloride due to conductive heat exchange with the overlying and underlying strata. Joint analysis of temperature and chloride allows estimation of the onset and duration of degassing pulses, refining the chronology of recent magmatic intrusion.

  11. CO2 driven weathering vs plume driven weathering as inferred from the groundwater of a persistently degassing basaltic volcano: Mt. Etna

    Science.gov (United States)

    Liotta, Marcello; D'Alessandro, Walter

    2016-04-01

    At Mt. Etna the presence of a persistent volcanic plume provides large amounts of volcanogenic elements to the bulk deposition along its flanks. The volcanic plume consists of solid particles, acidic droplets and gaseous species. After H2O and CO2, S, Cl and F represent the most abundant volatile elements emitted as gaseous species from the craters. During rain events acidic gases interact rapidly with droplets lowering the pH of rain. This process favors the dissolution and dissociation of the most acidic gases. Under these conditions, the chemical weathering of volcanic rocks and ashes is promoted by the acid rain during its infiltration. Subsequently during groundwater circulation, chemical weathering of volcanic rocks is also driven by the huge amount of deep magmatic carbon dioxide (CO2) coming up through the volcanic edifice and dissolving in the water. These two different weathering steps occur under very different conditions. The former occurs in a highly acidic environment (pH rates depend strongly on the pH, while the latter usually occurs under slightly acidic conditions since the pH has been already neutralized by the interaction with volcanics rocks. The high content of chlorine is mainly derived from interactions between the plume and rainwater, while the total alkalinity can be completely ascribed to the dissociation of carbonic acid (H2CO3) after the hydration of CO2. The relative contributions of plume-derived elements/weathering and CO2-driven weathering has been computed for each element. In addition, the comparison between the chemical compositions of the bulk deposition and of groundwater provides a new understanding about the mobility of volatile elements. Other processes such as ion exchange, iddingsite formation, and carbonate precipitation can also play roles, but only to minor extents. The proposed approach has revealed that the persistent plume strongly affects the chemical composition of groundwater at Mt. Etna and probably also at other

  12. Hydrothermal Valorization of Steel Slags—Part I: Coupled H2 Production and CO2 Mineral Sequestration

    Directory of Open Access Journals (Sweden)

    Camille Crouzet

    2017-10-01

    Full Text Available A new process route for the valorization of BOF steel slags combining H2 production and CO2 mineral sequestration is investigated at 300°C (HT under hydrothermal conditions. A BOF steel slag stored several weeks outdoor on the production site was used as starting material. To serve as a reference, room temperature (RT carbonation of the same BOF steel slag has been monitored with in situ Raman spectroscopy and by measuring pH and PCO2 on a time-resolved basis. CO2 uptake under RT and HT are, respectively, 243 and 327 kg CO2/t of fresh steel slag, which add up with the 63 kg of atmospheric CO2 per ton already uptaken by the starting steel slag on the storage site. The CO2 gained by the sample at HT is bounded to the carbonation of brownmillerite. H2 yield decreased by about 30% in comparison to the same experiment performed without added CO2, due to sequestration of ferrous iron in a Mg-rich siderite phase. Ferric iron, initially present in brownmillerite, is partitioned between an Fe-rich clay mineral of saponite type and metastable hematite. Saponite is likely stabilized by the presence of Al, whereas hematite may represent a metastable product of brownmillerite carbonation. Mg-rich wüstite is involved in at least two competing reactions, i.e., oxidation into magnetite and carbonation into siderite. Results of both water-slag and water-CO2-slag experiments after 72 h are consistent with a kinetics enhancement of the former reaction when a CO2 partial pressure imposes a pH between 5 and 6. Three possible valorization routes, (1 RT carbonation prior to hydrothermal oxidation, (2 RT carbonation after hydrothermal treatment, and (3 combined HT carbonation and oxidation are discussed in light of the present results and literature data.

  13. Total (fumarolic?+?diffuse soil) CO2 output from Furnas volcano

    OpenAIRE

    Pedone, M.; Viveiros, F.; Aiuppa, A.; Giudice, G.; Grassa, F.; Gagliano, A. L.; Francofonte, V.; Ferreira, T.

    2015-01-01

    Furnas volcano, in S?o Miguel island (Azores), being the surface expression of rising hydrothermal steam, is the site of intense carbon dioxide (CO2) release by diffuse degassing and fumaroles. While the diffusive CO2 output has long (since the early 1990s) been characterized by soil CO2 surveys, no information is presently available on the fumarolic CO2 output. Here, we performed (in August 2014) a study in which soil CO2 degassing survey was combined for the first time with the measurement ...

  14. Spatial and temporal variations of diffuse CO_{2} degassing at the N-S volcanic rift-zone of Tenerife (Canary Islands, Spain) during 2002-2015 period

    Science.gov (United States)

    Alonso, Mar; Ingman, Dylan; Alexander, Scott; Barrancos, José; Rodríguez, Fátima; Melián, Gladys; Pérez, Nemesio M.

    2016-04-01

    Tenerife is the largest of the Canary Islands and, together with Gran Canaria Island, is the only one with a central volcanic complex that started to grow at about 3.5 Ma. Nowadays the central complex is formed by Las Cañadas caldera, a volcanic depression measuring 16×9 km that resulted from multiple vertical collapses and was partially filled by post-caldera volcanic products. Up to 297 mafic monogenetic cones have been recognized on Tenerife, and they represent the most common eruptive activity occurring on the island during the last 1 Ma (Dóniz et al., 2008). Most of the monogenetic cones are aligned following a triple junction-shaped rift system, as result of inflation produced by the concentration of emission vents and dykes in bands at 120o to one another as a result of minimum stress fracturing of the crust by a mantle upwelling. The main structural characteristic of the southern volcanic rift (N-S) of the island is an apparent absence of a distinct ridge, and a fan shaped distribution of monogenetic cones. Four main volcanic successions in the southern volcanic rift zone of Tenerife, temporally separated by longer periods (˜70 - 250 ka) without volcanic activity, have been identified (Kröchert and Buchner, 2008). Since there are currently no visible gas emissions at the N-S rift, diffuse degassing surveys have become an important geochemical tool for the surveillance of this volcanic system. We report here the last results of diffuse CO2 efflux survey at the N-S rift of Tenerife, performed using the accumulation chamber method in the summer period of 2015. The objectives of the surveys were: (i) to constrain the total CO2 output from the studied area and (ii) to evaluate occasional CO2 efflux surveys as a volcanic surveillance tool for the N-S rift of Tenerife. Soil CO2 efflux values ranged from non-detectable up to 31.7 g m-2 d-1. A spatial distribution map, constructed following the sequential Gaussian simulation (sGs) procedure, did not show an

  15. Hydrothermal synthesis of Mn-doped ZnCo2O4 electrode material for high-performance supercapacitor

    Science.gov (United States)

    Mary, A. Juliet Christina; Bose, A. Chandra

    2017-12-01

    Mn-doped ZnCo2O4 nanoparticle has been synthesized by hydrothermal method without adding any surfactants. Structural, morphological and electrochemical performances have been studied for the pure and various concentration of Mn-doped ZnCo2O4 nanoparticles. XRD and Raman studies demonstrate the crystalline structure of the material. Specific capacitance of the 10 wt% Mn doped ZnCo2O4 nanomaterial is analysed using the three-electrode system. 10 wt% Mn-doped ZnCo2O4 has a maximum capacitance of 707.4 F g-1 at a current density of 0.5 A g-1. Coulombic efficiency of the material is 96.3% for 500 cycles in the KOH electrolyte medium. A two-electrode device using 10 wt% Mn-doped ZnCo2O4 exhibits the highest specific capacitance of 6.5 F g-1 at a current density of 0.03 A g-1 which is the suitable material for supercapacitor application.

  16. Hydrothermal synthesis of NiCo2O4 nanowires/nitrogen-doped graphene for high-performance supercapacitor

    International Nuclear Information System (INIS)

    Yu, Mei; Chen, Jianpeng; Ma, Yuxiao; Zhang, Jingdan; Liu, Jianhua; Li, Songmei; An, Junwei

    2014-01-01

    Highlights: • NCO/NG composites were synthesized in a water–glycerol mixed solvent via hydrothermal treatment and subsequent calcination. • NiCo 2 O 4 nanowires are dispersed on NG nanosheets and the composite has porous structure. • The NCO/NG composite exhibits a high specific capacitance and long cycling performance. - Abstract: NiCo 2 O 4 nanowires/nitrogen-doped graphene (NCO/NG) composite materials were synthesized by hydrothermal treatment in a water–glycerol mixed solvent and subsequent thermal transformation. The obtained materials were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. The electrochemical performance of the composites was evaluated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectrum techniques. NiCo 2 O 4 nanowires are densely coated by nitrogen-doped graphene and the composite displays good electrochemical performance. The maximum specific capacitance of NCO/NG is 1273.13 F g −1 at 0.5 A g −1 in 6 M KOH aqueous solution, and it exhibits good capacity retention without noticeable degradation after 3000 cycles at 4 A g −1

  17. Hydrothermal synthesis of NiCo2O4 nanowires/nitrogen-doped graphene for high-performance supercapacitor

    Science.gov (United States)

    Yu, Mei; Chen, Jianpeng; Ma, Yuxiao; Zhang, Jingdan; Liu, Jianhua; Li, Songmei; An, Junwei

    2014-09-01

    NiCo2O4 nanowires/nitrogen-doped graphene (NCO/NG) composite materials were synthesized by hydrothermal treatment in a water-glycerol mixed solvent and subsequent thermal transformation. The obtained materials were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. The electrochemical performance of the composites was evaluated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectrum techniques. NiCo2O4 nanowires are densely coated by nitrogen-doped graphene and the composite displays good electrochemical performance. The maximum specific capacitance of NCO/NG is 1273.13 F g-1 at 0.5 A g-1 in 6 M KOH aqueous solution, and it exhibits good capacity retention without noticeable degradation after 3000 cycles at 4 A g-1.

  18. Hydrothermal pentose to furfural conversion and simultaneous extraction with SC-CO2--kinetics and application to biomass hydrolysates.

    Science.gov (United States)

    Gairola, Krishan; Smirnova, Irina

    2012-11-01

    This work explores hydrothermal d-xylose and hemicellulose to furfural conversion coupled with simultaneous furfural extraction by SC-CO(2) and the underlying reaction pathway. A maximum furfural yield of 68% was attained from d-xylose at 230°C and 12MPa. Additionally missing kinetic data for l-arabinose to furfural conversion was provided, showing close similarity to d-xylose. Furfural yields from straw and brewery waste hydrolysates were significantly lower than those obtained from model compounds, indicating side reactions with other hydrolysate components. Simultaneous furfural extraction by SC-CO(2) significantly increased extraction yield in all cases. The results indicate that furfural reacts with intermediates of pentose dehydration. The proposed processing route can be well integrated into existing lignocellulose biorefinery concepts. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. 210Pb, 230Th, and 10Be in Central Indian Basin seamount sediments: Signatures of degassing and hydrothermal alteration of recent origin

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Borole, D.V.; Aldahan, A.; Patil, S; Mascarenhas-Pereira, M.B.L.; Possnert, G.; Ericsson, T.; Ramaswamy, V.; Gupta, S

    , 230 Th, and 10 Be in Central Indian Basin seamount sediments: Signatures of degassing and hydrothermal alteration of recent origin B. N. Nath, 1 D. V. Borole, 1 A. Aldahan, 2 S. K. Patil, 3 M. B. L. Mascarenhas-Pereira, 1 G. Possnert, 4 T. Ericsson, 2... V. Ramaswamy, 1 and S. M. Gupta 1 Received 4 March 2008; revised 17 March 2008; accepted 8 April 2008; published 14 May 2008. [1] Isotopic ( 210 Pb, 238 U- 230 Th, 10 Be), major and trace elements, and micromorphological and microchemical data, were...

  20. Assessment of hydrothermal pretreatment of various lignocellulosic biomass with CO2 catalyst for enhanced methane and hydrogen production.

    Science.gov (United States)

    Eskicioglu, Cigdem; Monlau, Florian; Barakat, Abdellatif; Ferrer, Ivet; Kaparaju, Prasad; Trably, Eric; Carrère, Hélène

    2017-09-01

    Hydrothermal pretreatment of five lignocellulosic substrates (i.e. wheat straw, rice straw, biomass sorghum, corn stover and Douglas fir bark) were conducted in the presence of CO 2 as a catalyst. To maximize disintegration and conversion into bioenergy (methane and hydrogen), pretreatment temperatures and subsequent pressures varied with a range of 26-175 °C, and 25-102 bars, respectively. Among lignin, cellulose and hemicelluloses, hydrothermal pretreatment caused the highest reduction (23-42%) in hemicelluloses while delignification was limited to only 0-12%. These reductions in structural integrity resulted in 20-30% faster hydrolysis rates during anaerobic digestion for the pretreated substrates of straws, sorghum, and corn stover while Douglas fir bark yielded 172% faster hydrolysis/digestion due to its highly refractory nature in the control. Furans and phenolic compounds formed in the pretreated hydrolyzates were below the inhibitory levels for methane and hydrogen production which had a range of 98-340 ml CH 4 /g volatile solids (VS) and 5-26 ml H 2 /g VS, respectively. Results indicated that hydrothermal pretreatment is able to accelerate the rate of biodegradation without generating high levels of inhibitory compounds while showing no discernible effect on ultimate biodegradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Monitoring diffuse volcanic degassing during volcanic unrests: the case of Campi Flegrei (Italy).

    Science.gov (United States)

    Cardellini, C; Chiodini, G; Frondini, F; Avino, R; Bagnato, E; Caliro, S; Lelli, M; Rosiello, A

    2017-07-28

    In volcanoes with active hydrothermal systems, diffuse CO 2 degassing may constitute the primary mode of volcanic degassing. The monitoring of CO 2 emissions can provide important clues in understanding the evolution of volcanic activity especially at calderas where the interpretation of unrest signals is often complex. Here, we report eighteen years of CO 2 fluxes from the soil at Solfatara of Pozzuoli, located in the restless Campi Flegrei caldera. The entire dataset, one of the largest of diffuse CO 2 degassing ever produced, is made available for the scientific community. We show that, from 2003 to 2016, the area releasing deep-sourced CO 2 tripled its extent. This expansion was accompanied by an increase of the background CO 2 flux, over most of the surveyed area (1.4 km 2 ), with increased contributions from non-biogenic source. Concurrently, the amount of diffusively released CO 2 increased up to values typical of persistently degassing active volcanoes (up to 3000 t d -1 ). These variations are consistent with the increase in the flux of magmatic fluids injected into the hydrothermal system, which cause pressure increase and, in turn, condensation within the vapor plume feeding the Solfatara emission.

  2. Full synergistic effect of hydrothermal NiCo2O4 nanosheets/CuCo2O4 nanocones supported on Ni foam for high-performance asymmetric supercapacitors

    Science.gov (United States)

    Wen, Shiyang; Liu, Yu; Bai, Hongye; Shao, Rong; Xu, Wei; Shi, Weidong

    2018-06-01

    In this work, a series of NiCo2O4/CuCo2O4 composites were prepared by a two-step hydrothermal method. The optimized NiCo2O4/CuCo2O4 electrode shows more than 5 times area capacitance (4.97 F cm-2) than pure NiCo2O4 at the current density of 1 mA cm-2. The best performance of sample assembled an asymmetric supercapacitor could reach up to 42 F g-1 at the current density of 1 A g-1. In addition, the maximum energy density of 15 W h kg-1 was achieved with the power density of 814 W kg-1. The as-prepared active electrode material also reveals excellent cycling stability with 90.6% capacitance retention after 5000 cycles. These results indicate potential application in developing energy storage devices with high energy density power density.

  3. Rates of volcanic CO2 degassing from airborne determinations of SO2 Emission rates and plume CO2SO2: test study at Pu′u ′O′o Cone, Kilauea Volcano, Hawaii

    Science.gov (United States)

    Gerlach, Terrence M.; McGee, Kenneth A.; Sutton, A. Jefferson; Elias, Tamar

    1998-01-01

    We present an airborne method that eliminates or minimizes several disadvantages of the customary plume cross-section sampling method for determining volcanic CO2 emission rates. A LI-COR CO2analyzer system (LICOR), a Fourier transform infrared spectrometer system (FTIR), and a correlation spectrometer (COSPEC) were used to constrain the plume CO2/SO2 and the SO2 emission rate. The method yielded a CO2 emission rate of 300 td−1 (metric tons per day) for Pu′u ′O′o cone, Kilauea volcano, on 19 September 1995. The CO2/SO2 of 0.20 determined from airborne LICOR and FTIR plume measurements agreed with the CO2/SO2 of 204 ground-based samples collected from vents over a 14-year period since the Pu′u ′O′o eruption began in January 1983.

  4. Carbon dioxide degassing and thermal energy release at Vesuvio (Italy)

    Science.gov (United States)

    Frondini, F.; Chiodini, G.; Caliro, S.; Cardellini, C.; Granieri, D.

    2003-04-01

    At Vesuvio, basing on the data of the CO2 flux surveys carried out in April and May 2000, are discharged about 130 t d-1 of CO2 through soil diffuse degassing. In the crater area the distribution of the soil temperatures show a general correspondence between the CO2 flux anomalies and the high temperatures, suggesting that the heating of the soil is mainly due to the condensation of the rising volcanic-hydrothermal fluids. Considering that the original H2O/CO2 ratio of hydrothermal fluids is recorded by fumarolic effluents, the steam associated to the CO2 output has been computed and amount to is 475 t d-1. The energy produced by the steam condensation and cooling of the liquid phase is 1.26 1012 J d-1 (14.6 MW). The amounts of gas and energy released by Vesuvio are comparable to those released by other volcanic degassing areas of the world and their estimates, through periodical CO2 flux surveys, can constitute a powerful tool to monitor the activity of the volcano.

  5. Pinatubo Lake Chemistry and Degassing 1991-2010

    Science.gov (United States)

    Schwandner, F. M.; Newhall, C. G.; Christenson, B. W.; Apfelbeck, C. A.; Arpa, M. C. B.; Vaquilar, R.; Bariso, E.

    2016-12-01

    We review the history of degassing, bathymetry and water chemistry of the crater lake of Mt. Pinatubo (Philippines) using data obtained during 1991-2001, and 2010. In late 1992, the initial small lake had a significant acid-sulfate component from a volcanic degassing through a hydrothermal system and the lake, and anhydrite dissolution. Subsequently, this component was "drowned" by rainfall (2-4 m/y), meteoric groundwater draining from the crater walls into the lake, and a few neutral chloride crater wall springs. Conductivity-Temperature-Depth (CTD) measurements in August 2000 found a strong inverted thermal gradient below 20m depth, reaching over 70°C at 50-60 m depth. By January 2001 the lake had homogenized and was much cooler (27°C at all depths), and it was again well-mixed and still cool when re-surveyed in June 2001 and November 2010. By 2010, the lake was well mixed, at neutral pH, with no significant vertical or horizontal structure. Bubbling of a predominantly carbon dioxide (CO2) gas phase persists throughout the lake's history, some from 1991-92 magma and some from degassing of the long-standing (pre-1991) hydrothermal system fed from a deeper magmatic or mantle source. Crater wall fumaroles emit boiling-point hydrothermal gases dominated by water, air, and CO2.

  6. Spatial and temporal variations of diffuse CO2 degassing at El Hierro volcanic system: Relation to the 2011-2012 submarine eruption

    Science.gov (United States)

    Melián, Gladys; Hernández, Pedro A.; Padrón, Eleazar; Pérez, Nemesio M.; Barrancos, José; Padilla, Germán.; Dionis, Samara; Rodríguez, Fátima; Calvo, David; Nolasco, Dacil

    2014-09-01

    We report herein the results of extensive diffuse CO2 emission surveys performed on El Hierro Island in the period 1998-2012. More than 17,000 measurements of the diffuse CO2 efflux were carried out, most of them during the volcanic unrest period that started in July 2011. Two significant precursory signals based on geochemical and geodetical studies suggest that a magma intrusion processes might have started before 2011 in El Hierro Island. During the preeruptive and eruptive periods, the time series of the diffuse CO2 emission released by the whole island experienced two significant increases. The first started almost 2 weeks before the onset of the submarine eruption, reflecting a clear geochemical anomaly in CO2 emission, most likely due to increasing release of deep-seated magmatic gases to the surface. The second one, between 24 October and 27 November 2011, started before the most energetic seismic events of the volcanic-seismic unrest. The data presented here demonstrate that combined continuous monitoring studies and discrete surveys of diffuse CO2 emission provide important information to optimize the early warning system in volcano monitoring programs and to monitor the evolution of an ongoing volcanic eruption, even though it is a submarine eruption.

  7. Carbonate metasomatism and CO2 lithosphere-asthenosphere degassing beneath the western Mediterranean: An integrated model arising from petrological and geophysical data

    International Nuclear Information System (INIS)

    Frezzotti, Maria Luce; Peccerillo, Angelo; Panza, Giuliano

    2009-03-01

    We present an integrated petrological, geochemical, and geophysical model that offers an explanation for the present-day anomalously high non-volcanic deep (mantle derived) CO 2 emission in the Tyrrhenian region. We investigate how decarbonation or melting of carbonate-rich lithologies from a subducted lithosphere may affect the efficiency of carbon release in the lithosphere-asthenosphere system. We propose that melting of sediments and/or continental crust of the subducted Adriatic-Ionian (African) lithosphere at pressure greater than 4 GPa (130 km) may represent an efficient mean for carbon cycling into the upper mantle and into the exosphere in the Western Mediterranean area. Melting of carbonated lithologies, induced by the progressive rise of mantle temperatures behind the eastward retreating Adriatic-Ionian subducting plate, generates low fractions of carbonate-rich (hydrous-silicate) melts. Due to their low density and viscosity, such melts can migrate upward through the mantle, forming a carbonated partially molten CO 2 -rich mantle recorded by tomographic images in the depth range from 130 to 60 km. Upwelling in the mantle of carbonate-rich melts to depths less than 60 - 70 km, induces massive outgassing of CO 2 . Buoyancy forces, probably favored by fluid overpressures, are able to allow migration of CO 2 from the mantle to the surface, through deep lithospheric faults, and its accumulation beneath the Moho and within the lower crust. The present model may also explain CO 2 enrichment of the Etna active volcano. Deep CO 2 cycling is tentatively quantified in terms of conservative carbon mantle flux in the investigated area. (author)

  8. Soil temperature and CO2 degassing, SO2 fluxes and field observations before and after the February 29, 2016 new vent inside Nyiragongo crater

    Science.gov (United States)

    Balagizi, Charles M.; Yalire, Mathieu M.; Ciraba, Honoré M.; Kajeje, Vicky B.; Minani, Abel S.; Kinja, Annie B.; Kasereka, Marcellin M.

    2016-09-01

    Nyiragongo volcano threatens ˜1.5 million inhabitants of Goma (DR Congo) and Gisenyi (Rwanda) cities and people living in the surrounding villages. In 2002, the volcano produced lava flows which invaded Goma and destroyed the economic district of the city, forced a mass exodus of the population and caused the loss of several lives. Nyiragongo volcanic activity is therefore closely followed by the inhabitants, and any news related to increased activity agitates people in the area, especially those in Goma. Here, we report a short time series of soil temperature and carbon dioxide degassing for four locations, and plume sulphur dioxide fluxes preceding and following the opening of a new vent inside the main Nyiragongo crater on February 29, 2016. The observed sudden and unexpected changes in Nyiragongo activity raised the fear of a new volcanic eruption and led to panic in Goma and the surroundings, inducing some people to leaving the city. We use the dataset and field observations before and after the opening of the new vent, in conjunction with published information about Nyiragongo's eruptive mechanism and of the volcano's plumbing system geometry (mainly the crater), to show that the new vent was fed by magma intruded from the lava lake or the upper conduit.

  9. Flux and genesis of CO2 degassing from volcanic-geothermal fields of Gulu-Yadong rift in the Lhasa terrane, South Tibet: Constraints on characteristics of deep carbon cycle in the India-Asia continent subduction zone

    Science.gov (United States)

    Zhang, Lihong; Guo, Zhengfu; Sano, Yuji; Zhang, Maoliang; Sun, Yutao; Cheng, Zhihui; Yang, Tsanyao Frank

    2017-11-01

    Gulu-Yadong rift (GYR) is the longest extensional, NE-SW-trending rift in the Himalayas and Lhasa terrane of South Tibet. Many volcanic-geothermal fields (VGFs), which comprise intense hot springs, steaming fissures, geysers and soil micro-seepage, are distributed in the GYR, making it ideal area for studying deep carbon emissions in the India-Asia continent subduction zone. As for the northern segment of GYR in the Lhasa terrane, its total flux and genesis of CO2 emissions are poorly understood. Following accumulation chamber method, soil CO2 flux survey has been carried out in VGFs (i.e., Jidaguo, Ningzhong, Sanglai, Tuoma and Yuzhai from south to north) of the northern segment of GYR. Total soil CO2 output of the northern GYR is about 1.50 × 107 t a-1, which is attributed to biogenic and volcanic-geothermal source. Geochemical characteristics of the volcanic-geothermal gases (including CO2 and He) of the northern GYR indicate their significant mantle-derived affinities. Combined with previous petrogeochemical and geophysical data, our He-C isotope modeling calculation results show that (1) excess mantle-derived 3He reflects degassing of volatiles related with partial melts from enriched mantle wedge induced by northward subduction of the Indian lithosphere, and (2) the crust-mantle interaction can provide continuous heat and materials for the overlying volcanic-geothermal system, in which magma-derived volatiles are inferred to experience significant crustal contamination during their migration to the surface.

  10. One-step hydrothermal synthesis of sandwich-type NiCo2S4@reduced graphene oxide composite as active electrode material for supercapacitors

    Science.gov (United States)

    Wang, Fangping; Li, Guifang; Zhou, Qianqian; Zheng, Jinfeng; Yang, Caixia; Wang, Qizhao

    2017-12-01

    A facile one step hydrothermal process is developed for the synthesis of NiCo2S4@reduced graphene oxide (NiCo2S4@RGO) composite as electrode for electrochemical supercapacitors. This NiCo2S4@RGO electrode exhibits an ultrahigh specific capacitance of 2003 F g-1 at 1 A g-1 and 1726 F g-1 at 20 A g-1 (86.0% capacitance retention from 1 A g-1 to 20 A g-1), excellent cycling stabilities (86.0% retention after 3500 cycles). Moreover, an asymmetric supercapacitor is successfully assembled by using NiCo2S4@RGO nanoparticle as the positive electrode and active carbon(AC) as the negative electrode in 2 M KOH electrolyte. The fabricated NiCo2S4@RGO//AC asymmetric supercapacitor exhibits a high energy density of 21.9 Wh kg-1 at a power density of 417.1 W kg-1 and still remains an impressive energy density of 13.5 Wh kg-1 at a large power density of 2700 W kg-1. The results demonstrate that the NiCo2S4@RGO composite is a promising electrode material as supercapacitors in energy storage.

  11. Two-step hydrothermal synthesis of NiCo2S4/Co9S8 nanorods on nickel foam for high energy density asymmetric supercapacitors

    Science.gov (United States)

    Xu, Rui; Lin, Jianming; Wu, Jihuai; Huang, Miaoliang; Fan, Leqing; Chen, Hongwei; He, Xin; Wang, Yiting; Xu, Zedong

    2018-03-01

    It is still a huge challenge to obtain a high-energy-density asymmetric supercapacitors and develop an active electrode material with excellent electrochemical characteristics. Although NiCo2S4 has been considered as one of the promising positive electrode materials for asymmetric supercapacitors, the electrochemical performance of the NiCo2S4-based positive electrodes is still relatively low and cannot meet the demand in the devices. Herein, NiCo2S4/Co9S8 nanorods with a large capacitance are synthesized via a simple two-step hydrothermal treatment. A high-performance asymmetric supercapacitor operating at 1.6 V is successfully assembled using the NiCo2S4/Co9S8 nanorods as positive electrode and activated carbon as negative electrode in 3 M KOH aqueous electrolyte, which demonstrates a fairly high energy density of 49.6 Wh kg-1 at a power density of 123 W kg-1, an excellent capacitance of 0.91 F cm-2 (139.42 F g-1) at current density of 1 mA cm-2 as well as a remarkable cycling stability due to the high physical strength, the large specific surface area, and the good conductivity for NiCo2S4/Co9S8 nanorods and the brilliant synergistic effect for NiCo2S4 and Co9S8 electrode materials. The as-prepared NiCo2S4/Co9S8 nanorods open up a new platform as positive electrode material for high-energy-density asymmetric supercapacitors in energy-storage.

  12. A two-step hydrothermal synthesis approach to synthesize NiCo2S4/NiS hollow nanospheres for high-performance asymmetric supercapacitors

    Science.gov (United States)

    Xu, Rui; Lin, Jianming; Wu, Jihuai; Huang, Miaoliang; Fan, Leqing; He, Xin; Wang, Yiting; Xu, Zedong

    2017-11-01

    In this work, a high-performance asymmetric supercapacitor device based on NiCo2S4/NiS hollow nanospheres as the positive electrode and the porous activated carbon as the negative electrode was successfully fabricated via a facile two-step hydrothermal synthesis approach. This NiCo2S4/NiS//activated carbon asymmetric supercapacitor achieved a high energy density of 43.7 Wh kg-1 at a power density of 160 W kg-1, an encouraging specific capacitance of 123 F g-1 at a current density of 1 mA cm-2, as well as a long-term performance with capacitance degradation of 5.2% after 3000 consecutive cycles at 1 mA cm-2. Moreover, the NiCo2S4/NiS electrode also demonstrated an excellent specific capacitance (1947.5 F g-1 at 3 mA cm-2) and an outstanding cycling stability (retaining 90.3% after 1000 cycles). The remarkable electrochemical performances may be attributed to the effect of NiS doping on NiCo2S4 which could enlarge the surface area and increase the surface roughness.

  13. Turmoil at Turrialba Volcano (Costa Rica): Degassing and eruptive processes inferred from high-frequency gas monitoring

    Science.gov (United States)

    de Moor, J. Maarten; Aiuppa, A.; Avard, G.; Wehrmann, H.; Dunbar, N.; Muller, C.; Tamburello, G.; Giudice, G.; Liuzzo, M.; Moretti, R.; Conde, V.; Galle, B.

    2016-08-01

    Eruptive activity at Turrialba Volcano (Costa Rica) has escalated significantly since 2014, causing airport and school closures in the capital city of San José. Whether or not new magma is involved in the current unrest seems probable but remains a matter of debate as ash deposits are dominated by hydrothermal material. Here we use high-frequency gas monitoring to track the behavior of the volcano between 2014 and 2015 and to decipher magmatic versus hydrothermal contributions to the eruptions. Pulses of deeply derived CO2-rich gas (CO2/Stotal > 4.5) precede explosive activity, providing a clear precursor to eruptive periods that occurs up to 2 weeks before eruptions, which are accompanied by shallowly derived sulfur-rich magmatic gas emissions. Degassing modeling suggests that the deep magmatic reservoir is 8-10 km deep, whereas the shallow magmatic gas source is at 3-5 km. Two cycles of degassing and eruption are observed, each attributed to pulses of magma ascending through the deep reservoir to shallow crustal levels. The magmatic degassing signals were overprinted by a fluid contribution from the shallow hydrothermal system, modifying the gas compositions, contributing volatiles to the emissions, and reflecting complex processes of scrubbing, displacement, and volatilization. H2S/SO2 varies over 2 orders of magnitude through the monitoring period and demonstrates that the first eruptive episode involved hydrothermal gases, whereas the second did not. Massive degassing (>3000 T/d SO2 and H2S/SO2 > 1) followed, suggesting boiling off of the hydrothermal system. The gas emissions show a remarkable shift to purely magmatic composition (H2S/SO2 < 0.05) during the second eruptive period, reflecting the depletion of the hydrothermal system or the establishment of high-temperature conduits bypassing remnant hydrothermal reservoirs, and the transition from phreatic to phreatomagmatic eruptive activity.

  14. The geothermal system of Caviahue-Copahue Volcanic Complex (Chile-Argentina): New insights from self-potential, soil CO2 degassing, temperature measurements and helium isotopes, with structural and fluid circulation implications.

    Science.gov (United States)

    Roulleau, Emilie; Bravo, Francisco; Barde-Cabusson, Stephanie; Pizarro, Marcela; Muños, Carlos; Sanchez, Juan; Tardani, Daniele; Sano, Yuji; Takahata, Naoto; de Cal, Federico; Esteban, Carlos

    2016-04-01

    Geothermal systems represent natural heat transfer engines in a confined volume of rock which are strongly influenced by the regional volcano-tectonic setting controlling the formation of shallow magmatic reservoirs, and by the local faults/fracture network, that permits the development of hydrothermal circulation cells and promote the vertical migration of fluids and heat. In the Southern Volcanic Zone of Chile-Argentina, geothermal resources occur in close spatial relationship with active volcanism along the Cordillera which is primarily controlled by the 1000 km long, NNE Liquiñe-Ofqui Fault Zone (LOFZ), an intra-arc dextral strike-slip fault system, associated with second-order intra-arc anisotropy of overall NE-SW (extensional) and NW-SE orientation (compressional). However there is still a lack of information on how fault network (NE and WNW strinking faults) and lithology control the fluid circulation. In this study, we propose new data of dense self-potential (SP), soil CO2 emanation and temperature (T) measurements within the geothermal area from Caviahue-Copahue Volcanic Complex (CCVC), coupled with helium isotopes ratios measured in fumaroles and thermal springs. We observe that inside the geothermal system the NE-striking faults, characterized by a combination of SP-CO2 and T maxima with high 3He/4He ratios (7.86Ra), promote the formation of high vertical permeability pathways for fluid circulation. Whereas, the WNW-striking faults represent low permeability pathways for hydrothermal fluids ascent associated with moderate 3He/4He ratios (5.34Ra), promoting the infiltration of meteoric water at shallow depth. These active zones are interspersed by SP-CO2- T minima, which represent self-sealed zones (e.g. impermeable altered rocks) at depth, creating a barrier inhibiting fluids rise. The NE-striking faults seem to be associated with the upflow zones of the geothermal system, where the boiling process produces a high vapor-dominated zone close to the

  15. Dual stable isotopes of CH 4 from Yellowstone hot-springs suggest hydrothermal processes involving magmatic CO 2

    Energy Technology Data Exchange (ETDEWEB)

    Moran, James J.; Whitmore, Laura M.; Jay, Zackary J.; Jennings, Ryan deM.; Beam, Jacob P.; Kreuzer, Helen W.; Inskeep, William P.

    2017-07-01

    Volcanism and post-magmatism contribute both significant annual CH4 fluxes to the atmosphere (on par with other natural sources such as forest fire and wild animal emissions) and have been implicated in past climate-change events. The Yellowstone hot spot is one of the largest volcanic systems on Earth and is known to emit methane in addition to other greenhouse gases (e.g. carbon dioxide) but the ultimate source of this methane flux has not been elucidated. Here we use dual stable isotope analysis (δ2H and δ13C) of CH4(g) sampled from ten high-temperature geothermal pools in Yellowstone National Park to show that the predominant flux of CH4(g) is abiotic. The average δ13C and δ2H values of CH4(g) emitted from hot springs (-26.7 (±2.4) and -236.9 (±12.0) ‰, respectively) are not consistent with biotic (microbial or thermogenic) methane sources, but are within previously reported ranges for abiotic methane production. Correlation between δ13CCH4 and δ13C-dissolved inorganic C (DIC) also suggests that CO2 is a parent C source for the observed CH4(g). Moreover, CH4-CO2 isotopic geothermometry was used to estimate CH4(g) formation temperatures ranging from ~ 250 - 350°C, which is just below the temperature estimated for the hydrothermal reservoir and consistent with the hypothesis that subsurface, rock-water interactions are responsible for large methane fluxes from this volcanic system. An understanding of conditions leading to the abiotic production of methane and associated isotopic signatures are central to understanding the evolutionary history of deep carbon sources on Earth.

  16. A model of diffuse degassing at three subduction-related volcanoes

    Science.gov (United States)

    Williams-Jones, Glyn; Stix, John; Heiligmann, Martin; Charland, Anne; Sherwood Lollar, Barbara; Arner, N.; Garzón, Gustavo V.; Barquero, Jorge; Fernandez, Erik

    Radon, CO2 and δ13C in soil gas were measured at three active subduction-related stratovolcanoes (Arenal and Poás, Costa Rica; Galeras, Colombia). In general, Rn, CO2 and δ13C values are higher on the lower flanks of the volcanoes, except near fumaroles in the active craters. The upper flanks of these volcanoes have low Rn concentrations and light δ13C values. These observations suggest that diffuse degassing of magmatic gas on the upper flanks of these volcanoes is negligible and that more magmatic degassing occurs on the lower flanks where major faults and greater fracturing in the older lavas can channel magmatic gases to the surface. These results are in contrast to findings for Mount Etna where a broad halo of magmatic CO2 has been postulated to exist over much of the edifice. Differences in radon levels among the three volcanoes studied here may result from differences in age, the degree of fracturing and faulting, regional structures or the level of hydrothermal activity. Volcanoes, such as those studied here, act as plugs in the continental crust, focusing magmatic degassing towards crater fumaroles, faults and the fractured lower flanks.

  17. Sup(210)Pb, sup(230)Th, and sup(10)Be in Central Indian Basin seamount sediments: Signatures of degassing and hydrothermal alteration of recent origin

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Borole, D.V.; Aldahan, A.; Patil, S.K.; Mascarenhas-Pereira, M.B.L.; Possnert, G.; Ericsson, T.; Ramaswamy, V.; Gupta, S.M.

    ) the presence of altered minerals such as smectite and zeolites, and 4) distinctly different magnetic properties in the altered sediments. A predominant influence of neutral chloride type hydrothermal fluids is interpreted. This is the first report of recently...

  18. Fabrication of free-standing NiCo2O4 nanoarrays via a facile modified hydrothermal synthesis method and their applications for lithium ion batteries and high-rate alkaline batteries

    International Nuclear Information System (INIS)

    Zheng, Qingyun; Zhang, Xiangyang; Shen, Youming

    2015-01-01

    Graphical abstract: Hydrothermal-synthesized NiCo 2 O 4 nanoflake arrays exhibit porous structure and high capacity as well as good cycling life for lithium ion batteries and alkaline batteries. - Highlights: • Self-supported NiCo 2 O 4 nanoflake arrays are prepared by a hydrothermal method. • NiCo 2 O 4 nanoflake arrays show high capacity and good cycling life. • Porous nanoflake arrays structure is favorable for fast ion/electron transfer. - Abstract: Self-supported NiCo 2 O 4 nanoflake arrays on nickel foam are prepared by a facile hydrothermal method. The obtained NiCo 2 O 4 nanoflakes with thicknesses of ∼25 nm grow vertically to the nickel foam substrate and form an interconnected porous network with pore diameters of 50–500 nm. As anode material of LIBs, the NiCo 2 O 4 nanoflake arrays show a high initial coulombic efficiency of 76%, as well as good cycling stability with a capacity of 880 mAh g −1 at 0.5 A g −1 , and 523 mAh g −1 at 1.5 A g −1 after 50 cycles. As the cathode of alkaline batteries, a high capacity of 95 mAh g −1 is achieved at 2 A g −1 and 94% retention is maintained after 10,000 cycles. The superior electrochemical performance is mainly due to the unique nanoflake arrays structure with large surface area and shorter diffusion length for mass and charge transport

  19. The persistent and pernicious myth of the early CO2-N2 atmospheres of terrestrial planets

    Science.gov (United States)

    Shaw, G. H.

    2009-12-01

    The accepted model for early atmospheres of terrestrial planets has settled on a CO2-N2 composition. Unfortunately, while it is largely based on a brilliant geological analysis by Rubey, there is no compelling evidence whatsoever for such a composition as the first “permanent” atmosphere for Earth or any other planet. In fact, geological discoveries of the past 50+ years reveal several problems with a CO2-N2 atmosphere, some of which Rubey recognized in his own analysis. He clearly addressed the problem of timing of degassing, concluding that early massive degassing of CO2 would produce readily observed and profound effects, which are not evident. Modeling and constraints on the timing of planetary accretion and core formation indicate massive early degassing. If early degassing emitted CO2-N2, the effects are concealed. Plate tectonic recycling is not a solution, as conditions would have persisted beyond the time of the earliest rocks, which do not show the effects. Attempts to return degassed CO2 to the mantle are not only ad hoc, but inconsistent with early thermal structure of the Earth. Second, production of prebiotic organic compounds from a CO2-N2 atmosphere has been a nagging problem. At best this has been addressed by invoking hydrogen production from the mantle to provide reducing capacity. While hydrogen may be emitted in volcanic eruptions, it is exceedingly difficult to imagine this process generating enough organics to yield high concentrations in a global ocean. The recent fashion of invoking organic synthesis at deep-sea vents suffers from the same problem: how to achieve sufficient concentrations of organics in a global ocean by abiotic synthesis when hydrothermal activity stirs the solution and carries the prebiotic products off to great dilution? Suggesting life began at deep-sea vents, and continues to carry on chemosynthesis there, begs the question. Unless you get high enough concentrations of prebiotics by abiotic processes, you simply

  20. Hydrothermal circulation, serpentinization, and degassing at a rift valley-fracture zone intersection: Mid-Atlantic Ridge near 15[degree]N, 45[degree]W

    Energy Technology Data Exchange (ETDEWEB)

    Rona, P.A.; Nelson, T.A. (National Oceanic and Atmospheric Administration, Miami, FL (United States)); Bougault, H.; Charlou, J.L.; Needham, H.D. (Inst. Francais de Recherche pour I' Exploitation de la Mer, Centre de Brest (France)); Appriou, P. (Univ. of Western Brittany, Brest (France)); Trefry, J.H. (Florida Inst. of Technology, Melbourne (United States)); Eberhart, G.L.; Barone, A. (Lamont-Doherty Geological Observatory, Palisades, NY (United States))

    1992-09-01

    A hydrothermal system characterized by high ratios of methane to both manganese and suspended particulate matter was detected in seawater sampled at the eastern intersection of the rift valley of the Mid-Atlantic Ridge with the Fifteen-Twenty Fracture Zone. This finding contrasts with low ratios in black smoker-type hydrothermal systems that occur within spreading segments. Near-bottom water sampling coordinated with SeaBeam bathymetry and camera-temperature tows detected the highest concentrations of methane at fault zones in rocks with the appearance of altered ultramafic units in a large dome that forms part of the inside corner high at the intersection. The distinct chemical signatures of the two types of hydrothermal systems are inferred to be controlled by different circulation pathways related to reaction of seawater primarily with ultramafic rocks at intersections of spreading segments with fracture zones but with mafic rocks within spreading segments.

  1. Microbial community in a sediment-hosted CO(2) lake of the southern Okinawa Trough hydrothermal system RID C-8303-2011

    DEFF Research Database (Denmark)

    Inagaki, Fumio; Kuypers, Marcel M. M.; Tsunogai, Urumu

    2006-01-01

    pavements above the CO(2) lake, decreasing to strikingly low cell numbers (107 CM-3) at the liquid CO(2)/CO(2)-hydrate interface. The key groups in these sediments were as follows: (i) the anaerobic methanotrophic archaea ANME-2c and the Eel-2 group of Deltaproteobacteria and (ii) sulfur...

  2. Volcanic gas composition changes during the gradual decrease of the gigantic degassing activity of Miyakejima volcano, Japan, 2000-2015

    Science.gov (United States)

    Shinohara, Hiroshi; Geshi, Nobuo; Matsushima, Nobuo; Saito, Genji; Kazahaya, Ryunosuke

    2017-02-01

    The composition of volcanic gases discharged from Miyakejima volcano has been monitored during the intensive degassing activity that began after the eruption in 2000. During the 15 years from 2000 to 2015, Miyakejima volcano discharged 25.5 Mt of SO2, which required degassing of 3 km3 of basaltic magma. The SO2 emission rate peaked at 50 kt/day at the end of 2000 and quickly decreased to 5 kt/day by 2003. During the early degassing period, the volcanic gas composition was constant with the CO2/SO2 = 0.8 (mol ratio), H2O/SO2 = 35, HCl/SO2 = 0.08, and SO2/H2S = 15. The SO2 emission rate decreased gradually to 0.5 kt/day by 2012, and the gas composition also changed gradually to CO2/SO2 = 1.5, H2O/SO2 = 150, HCl/SO2 = 0.15, and SO2/H2S = 6. The compositional changes are not likely caused by changes in degassing pressure or volatile heterogeneity of a magma chamber but are likely attributed to an increase of hydrothermal scrubbing caused by large decrease of the volcanic gas emission rate, suggesting a supply of gases with constant composition during the 15 years. The intensive degassing was modeled based on degassing of a convecting magma conduit. The gradual SO2 emission rate that decrease without changes in volcanic gas composition is attributed to a reduction of diameter of the convecting magma conduit.

  3. Direct measurement of CO2 solubility and pH in NaCl hydrothermal solutions by combining in-situ potentiometry and Raman spectroscopy up to 280 °C and 150 bar

    Science.gov (United States)

    Truche, Laurent; Bazarkina, Elena F.; Berger, Gilles; Caumon, Marie-Camille; Bessaque, Gilles; Dubessy, Jean

    2016-03-01

    The in-situ monitoring of aqueous solution chemistry at elevated temperatures and pressures is a major challenge in geochemistry. Here, we combined for the first time in-situ Raman spectroscopy for concentration measurements and potentiometry for pH measurement in a single hydrothermal cell equipped with sampling systems and operating under controlled conditions of temperature and pressure. Dissolved CO2 concentration and pH were measured at temperatures up to 280 °C and pressures up to 150 bar in the H2O-CO2 and H2O-CO2-NaCl systems. A Pitzer specific-ion-interaction aqueous model was developed and confirmed the accuracy and consistency of the measurements, at least up to 250 °C. The revised Pitzer parameters for the H2O-CO2-NaCl system were formatted for the Phreeqc geochemical software. Significant changes with respect to the Pitzer.dat database currently associated with Phreeqc were observed. The new model parameters are now available for further applications. The Raman and pH probes tested here may also be applied to field monitoring of hydrothermal springs, geothermal wells, and oil and gas boreholes.

  4. Continuous in situ measurements of volcanic gases with a diode-laser-based spectrometer: CO2 and H2O concentration and soil degassing at Vulcano (Aeolian islands: Italy

    Directory of Open Access Journals (Sweden)

    De Natale Paolo

    2007-04-01

    Full Text Available Abstract We report on a continuous-measurement campaign carried out in Vulcano (Aeolian islands, Sicily, devoted to the simultaneous monitoring of CO2 and H2O concentrations. The measurements were performed with an absorption spectrometer based on a semiconductor laser source emitting around a 2-μm wavelength. The emitted radiation was selectively absorbed by two molecular ro-vibrational transitions specific of the investigated species. Data for CO2 and H2O concentrations, and CO2 soil diffusive flux using an accumulation chamber configuration, were collected at several interesting sampling points on the island (Porto Levante beach- PLB, Fossa Grande Crater – FOG- and Valley of Palizzi, PAL. CO2/H2O values, measured on the ground, are very similar (around 0.019 (± 0.006 and comparable to the previous discrete detected values of 0.213 (Fumarole F5-La Fossa crater rim and 0.012 (Fumarole VFS – Baia Levante beach obtaid during the 1977–1993 heating phase of the crater fumaroles. In this work much more homogeneous values are found in different points of the three sites investigated. The field work, although carried out in a limited time window (25th–28th August 2004, pointed out the new apparatus is suitable for continuous gas monitoring of the two species and their ratios, which are important geochemical indicators of volcanic activity, for which other reliable continuous monitoring systems are not yet available.

  5. Continuous in situ measurements of volcanic gases with a diode-laser-based spectrometer: CO2 and H2O concentration and soil degassing at Vulcano (Aeolian islands: Italy).

    Science.gov (United States)

    De Rosa, Maurizio; Gagliardi, Gianluca; Rocco, Alessandra; Somma, Renato; De Natale, Paolo; De Natale, Giuseppe

    2007-04-20

    We report on a continuous-measurement campaign carried out in Vulcano (Aeolian islands, Sicily), devoted to the simultaneous monitoring of CO2 and H2O concentrations. The measurements were performed with an absorption spectrometer based on a semiconductor laser source emitting around a 2-microm wavelength. The emitted radiation was selectively absorbed by two molecular ro-vibrational transitions specific of the investigated species. Data for CO2 and H2O concentrations, and CO2 soil diffusive flux using an accumulation chamber configuration, were collected at several interesting sampling points on the island (Porto Levante beach- PLB, Fossa Grande Crater - FOG- and Valley of Palizzi, PAL). CO2/H2O values, measured on the ground, are very similar (around 0.019 (+/- 0.006)) and comparable to the previous discrete detected values of 0.213 (Fumarole F5-La Fossa crater rim) and 0.012 (Fumarole VFS - Baia Levante beach) obtaid during the 1977-1993 heating phase of the crater fumaroles. In this work much more homogeneous values are found in different points of the three sites investigated. The field work, although carried out in a limited time window (25th-28th August 2004), pointed out the new apparatus is suitable for continuous gas monitoring of the two species and their ratios, which are important geochemical indicators of volcanic activity, for which other reliable continuous monitoring systems are not yet available.

  6. Geophysical image of the hydrothermal system of Merapi volcano

    Science.gov (United States)

    Byrdina, S.; Friedel, S.; Vandemeulebrouck, J.; Budi-Santoso, A.; Suhari; Suryanto, W.; Rizal, M. H.; Winata, E.; Kusdaryanto

    2017-01-01

    We present an image of the hydrothermal system of Merapi volcano based on results from electrical resistivity tomography (ERT), self-potential, and CO2 flux mappings. The ERT models identify two distinct low-resistivity bodies interpreted as two parts of a probably interconnected hydrothermal system: at the base of the south flank and in the summit area. In the summit area, a sharp resistivity contrast at ancient crater rim Pasar-Bubar separates a conductive hydrothermal system (20-50 Ω m) from the resistive andesite lava flows and pyroclastic deposits (2000-50,000 Ω m). The existence of preferential fluid circulation along this ancient crater rim is also evidenced by self-potential data. The significative diffuse CO2 degassing (with a median value of 400 g m-2 d-1) is observed in a narrow vicinity of the active crater rim and close to the ancient rim of Pasar-Bubar. The total CO2 degassing across the accessible summital area with a surface of 1.4 ṡ 105 m2 is around 20 t d-1. Before the 2010 eruption, Toutain et al. (2009) estimated a higher value of the total diffuse degassing from the summit area (about 200-230 t d-1). This drop in the diffuse degassing from the summit area can be related to the decrease in the magmatic activity, to the change of the summit morphology, to the approximations used by Toutain et al. (2009), or, more likely, to a combination of these factors. On the south flank of Merapi, the resistivity model shows spectacular stratification. While surficial recent andesite lava flows are characterized by resistivity exceeding 100,000 Ω m, resistivity as low as 10 Ω m has been encountered at a depth of 200 m at the base of the south flank and was interpreted as a presence of the hydrothermal system. No evidence of the hydrothermal system is found on the basis of the north flank at the same depth. This asymmetry might be caused by the asymmetry of the heat supply source of Merapi whose activity is moving south or/and to the asymmetry in

  7. The November 2002 degassing event at Panarea Island (Italy: five months of geochemical monitoring

    Directory of Open Access Journals (Sweden)

    P. L. Rossi

    2005-06-01

    Full Text Available On 3rd November 2002, at about 3 km off-shore of Panarea Island (Aeolian Islands, Southern Italy, a series of gas vents suddenly and violently opened from the seafloor at the depth of 10-15 m, with an unusually high gas flux and superimposing on the already existing submarine fumarolic field. Starting from the 12th November 2002 a discontinuous geochemical monitoring program was carried out. The emissions consisted in an emulsion whose liquid phase derived from condensation of an uprising vapor phase occurring close to the fluid outlets without significant contamination by seawater. The whole composition of the fluids was basically H2O- and CO2-dominated, with minor amounts of typical «hydrothermal» components (such as H2S, H2, CO and light hydrocarbons, atmospheric-related compounds, and characterized by the occurrence of a significant magmatic gas fraction (mostly represented by SO2, HCl and HF. According to the observed temporal variability of the fluid compositions, between November and December 2002 the hydrothermal feeding system was controlled by oxidizing conditions due to the input of magmatic gases. The magmatic degassing phenomena showed a transient nature, as testified by the almost complete disappearance of the magmatic markers in a couple of months and by the restoration, since January 2003, of the chemical features of the existing hydrothermal system. The most striking feature of the evolution of the «Panarea degassing event» was the relatively rapid restoration of the typical reducing conditions of a stationary hydrothermal system, in which the FeO/Fe1.5O redox pair of the rock mineral phases has turned to be the dominating redox controlling system.

  8. Hexatungstate subunit as building block in the hydrothermal synthesis of organic-inorganic hybrid materials: synthesis, structure and optical properties of Co2(bpy)6 (W6O19)2 (bpy=4,4'-bipyridine)

    International Nuclear Information System (INIS)

    Zhang Lijuan; Wei Yongge; Wang Chongchen; Guo Hongyou; Wang Ping

    2004-01-01

    A hydrothermal reaction of WO 3 , CoCl 2 and 4,4'-bipyridine, yields a novel organic-inorganic hybrid compound, Co 2 (bpy) 6 (W 6 O 19 ) 2 , at 170 deg. C. X-ray single crystal structure determination reveals a two-dimensional covalent structure belonging to monoclinic crystal system, space group C2/c, with cell parameters a=19.971(4) A, b=11.523(2) A, c=16.138(3) A, β=96.49(3) deg., V=3690.0 A 3 and Z=2. The hexatungstate, [W 6 O 19 ] 2- , acts as a building block in bidentate fashion to bridge the Co(II) centers in the crystal structure. The title compound is found to have an optical energy gap of 2.2 eV from UV-Vis-NIR reflectance spectra

  9. Decadal-scale variability of diffuse CO2 emissions and seismicity revealed from long-term monitoring (1995–2013) at Mammoth Mountain, California, USA

    Science.gov (United States)

    Werner, Cynthia A.; Bergfeld, Deborah; Farrar, Chris; Doukas, Michael P.; Kelly, Peter; Kern, Christoph

    2014-01-01

    Mammoth Mountain, California, is a dacitic volcano that has experienced several periods of unrest since 1989. The onset of diffuse soil CO2 emissions at numerous locations on the flanks of the volcano began in 1989–1990 following an 11-month period of heightened seismicity. CO2 emission rates were measured yearly from 1995 to 2013 at Horseshoe Lake (HSL), the largest tree kill area on Mammoth Mountain, and measured intermittently at four smaller degassing areas around Mammoth from 2006 to 2013. The long-term record at HSL shows decadal-scale variations in CO2 emissions with two peaks in 2000–2001 and 2011–2012, both of which follow peaks in seismicity by 2–3 years. Between 2000 and 2004 emissions gradually declined during a seismically quiet period, and from 2004 to 2009 were steady at ~ 100 metric tonnes per day (t d− 1). CO2emissions at the four smaller tree-kill areas also increased by factors of 2–3 between 2006 and 2011–2012, demonstrating a mountain-wide increase in degassing. Delays between the peaks in seismicity and degassing have been observed at other volcanic and hydrothermal areas worldwide, and are thought to result from an injection of deep CO2-rich fluid into shallow subsurface reservoirs causing a pressurization event with a delayed transport to the surface. Such processes are consistent with previous studies at Mammoth, and here we highlight (1) the mountain-wide response, (2) the characteristic delay of 2–3 years, and (3) the roughly decadal reoccurrence interval for such behavior. Our best estimate of total CO2 degassing from Mammoth Mountain was 416 t d− 1 in 2011 during the peak of emissions, over half of which was emitted from HSL. The cumulative release of CO2 between 1995 and 2013 from diffuse emissions is estimated to be ~ 2–3 Mt, and extrapolation back to 1989 gives ~ 4.8 Mt. This amount of CO2 release is similar to that produced by the mid-sized (VEI 3) 2009 eruption of Redoubt Volcano in Alaska (~ 2.3

  10. Asymmetrical hydrothermal system below Merapi volcano imaged by geophysical data.

    Science.gov (United States)

    Byrdina, Svetlana; Friedel, Sven; Budi-Santoso, Agus; Suryanto, Wiwit; Suhari, Aldjarishy; Vandemeulebrouck, Jean; Rizal, Mohhamed H.; Grandis, Hendra

    2017-04-01

    A high-resolution image of the hydrothermal system of Merapi volcano is obtained using electrical resistivity tomography (ERT), self-potential, and CO2 flux mappings. The ERT inversions identify two distinct low-resistivity bodies, at the base of the south flank and in the summit area, that represent likely two parts of an interconnected hydrothermal system. In the summit area, the extension of the hydrothermal system is clearly limited by the main geological structures which are actual and ancient craters. A sharp resistivity contrast at ancient crater rim Pasar-Bubar separates a conductive hydrothermal system (20 - 50 Ωm) from the resistive andesite lava flows and pyroclastic deposits (2000 - 50 000 Ωm). High diffuse CO2 degassing (with a median value of 400g m -2 d -1) is observed in a narrow vicinity of the active crater rim and close to the Pasar-Bubar. The existence of preferential fluid circulation along this ancient crater rim is also evidenced by self-potential data. The total CO2 degassing across the accessible summit area with a surface of 1.4 · 10 5 m 2 is around 20 td -1. Before the 2010 eruption, Toutain et al. (2009) estimated a higher value of the total diffuse degassing from the summit area (about 200 - 230 td -1). This drop in the diffuse degassing can be related to the decrease in the magmatic activity, to the change of the summit morphology or to a combination of these factors. On the south flank of Merapi, the resistivity model shows spectacular stratification. While surficial recent andesite lava flows are characterized by resistivity exceeding 100 000 Ωm, resistivity as low as 10 Ωm has been encountered at a depth of 200 m at the base of the south flank and was interpreted as a presence of the hydrothermal system. We suggest that a sandwich-like structure of stratified pyroclastic deposits on the flanks of Merapi screen and separate the flow of hydrothermal fluids with the degassing occurring mostly through the fractured crater rims

  11. Carbon dioxide in magmas and implications for hydrothermal systems

    Science.gov (United States)

    Lowenstern, J. B.

    2001-01-01

    This review focuses on the solubility, origin, abundance, and degassing of carbon dioxide (CO2) in magma-hydrothermal systems, with applications for those workers interested in intrusion-related deposits of gold and other metals. The solubility of CO2 increases with pressure and magma alkalinity. Its solubility is low relative to that of H2O, so that fluids exsolved deep in the crust tend to have high CO2/H2O compared with fluids evolved closer to the surface. Similarly, CO2/H2O will typically decrease during progressive decompression- or crystallization-induced degassing. The temperature dependence of solubility is a function of the speciation of CO2, which dissolves in molecular form in rhyolites (retrograde temperature solubility), but exists as dissolved carbonate groups in basalts (prograde). Magnesite and dolomite are stable under a relatively wide range of mantle conditions, but melt just above the solidus, thereby contributing CO2 to mantle magmas. Graphite, diamond, and a free CO2-bearing fluid may be the primary carbon-bearing phases in other mantle source regions. Growing evidence suggests that most CO2 is contributed to arc magmas via recycling of subducted oceanic crust and its overlying sediment blanket. Additional carbon can be added to magmas during magma-wallrock interactions in the crust. Studies of fluid and melt inclusions from intrusive and extrusive igneous rocks yield ample evidence that many magmas are vapor saturated as deep as the mid crust (10-15 km) and that CO2 is an appreciable part of the exsolved vapor. Such is the case in both basaltic and some silicic magmas. Under most conditions, the presence of a CO2-bearing vapor does not hinder, and in fact may promote, the ascent and eruption of the host magma. Carbonic fluids are poorly miscible with aqueous fluids, particularly at high temperature and low pressure, so that the presence of CO2 can induce immiscibility both within the magmatic volatile phase and in hydrothermal systems

  12. Fumarole/plume and diffuse CO2 emission from Sierra Negra caldera, Galapagos archipelago

    Science.gov (United States)

    Padrón, Eleazar; Hernández, Pedro A.; Pérez, Nemesio M.; Toulkeridis, Theofilos; Melián, Gladys; Barrancos, José; Virgili, Giorgio; Sumino, Hirochika; Notsu, Kenji

    2012-08-01

    Measurements of visible and diffuse gas emission were conducted in 2006 at the summit of Sierra Negra volcano, Galapagos, with the aim to better characterize degassing after the 2005 eruption. A total SO2 emission of 11 ± 2 t day-1 was derived from miniature differential optical absorption spectrometer (mini-DOAS) ground-based measurements of the plume emanating from the Mini Azufral fumarolic area, the most important site of visible degassing at Sierra Negra volcano. Using a portable multigas system, the H2S/SO2, CO2/SO2, and H2O/SO2 molar ratios in the Mina Azufral plume emissions were found to be 0.41, 52.2, and 867.9, respectively. The corresponding H2O, CO2, and H2S emission rates were 562, 394, and 3 t day-1, respectively. The total output of diffuse CO2 emissions from the summit of Sierra Negra volcano was 990 ± 85 t day-1, with 605 t day-1 being released by a deep source. The diffuse-to-plume CO2 emission ratio was about 1.5. Mina Azufral fumaroles released gasses containing 73.6 mol% of H2O; the main noncondensable components amounted to 97.4 mol% CO2, 1.5 mol% SO2, 0.6 mol% H2S, and 0.35 mol% N2. The higher H2S/SO2 ratio values found in 2006 as compared to those reported before the 2005 eruption reveal a significant hydrothermal contribution to the fumarolic emissions. 3He/4He ratios measured at Mina Azufral fumarolic discharges showed values of 17.88 ± 0.25 R A , indicating a mid-ocean ridge basalts (MORB) and a Galapagos plume contribution of 53 and 47 %, respectively.

  13. Long term monitoring at Solfatara of Pozzuoli (Campi Flegrei, Italy): 1998-2014, fifteen years of soil CO2 flux measurement.

    Science.gov (United States)

    Cardellini, Carlo; Chiodini, Giovanni; Rosiello, Angelo; Bagnato, Emanuela; Avino, Rosario; Frondini, Francesco; Donnini, Marco; Caliro, Stefano

    2015-04-01

    With a flux of deeply derived fluids of ~5000 t/d and an energetic release of ~100 MW Solfatara of Pozzuoli is one of the largest studied volcanic-hydrothermal system of the world. Since 1998, soil CO2 flux surveys where performed using the accumulation chamber method over a large area (1.45 km2), including the volcanic apparatus and its surroundings. The statistical elaboration of CO2 flux, also coupled with the investigation of the CO2 efflux isotopic composition, allowed to characterize both the CO2 flux connected to by biological activity in the soil and that feed to the degassing of the hydrothermal system. A geostatistical elaboration of CO2 fluxes based on sequential Gaussian simulations, allowed to define the spatial structure of the degassing area, pointing out the presence of a well defined diffuse degassing structure interested by the release of deeply derived CO2 (Solfatara DDS). Solfatara DDS results well correlated to volcanic and tectonic structures interesting the crater area and the eastern area of Pisciarelli. With the same approach the total amount of CO2 release was estimated to range between 754 t/d and 1530 t/d in the last fifteen year (with an error in the estimate varying between 9 and 15 %). Also the extension of the DDS experienced relevant variations varying between 4.5x105 m2 to 12.3 x105 m2. In particular two major changes occurred in the extension of the DDS, the first consisted in its doubling in 2003-2004 and the second in further enlargement of ~ 30% in 2011-2012, the last occurring after period of decreasing trend which interrupted 4-5 years of relative stability. These variations mainly occurred external to the crater area in correspondence of a NE-SW fault system where fluxes increased from background to values typical of the endogenous source. The first event was previously correlated with the occurrence in 2000 of a relatively deep seismic swarm, which was interpreted as the indicator of the opening of an easy-ascent pathway

  14. Gas geochemistry of natural analogues for the studies of geological CO2 sequestration

    International Nuclear Information System (INIS)

    Voltattorni, N.; Sciarra, A.; Caramanna, G.; Cinti, D.; Pizzino, L.; Quattrocchi, F.

    2009-01-01

    Geological sequestration of anthropogenic CO 2 appears to be a promising method for reducing the amount of greenhouse gases released to the atmosphere. Geochemical modelling of the storage capacity for CO 2 in saline aquifers, sandstones and/or carbonates should be based on natural analogues both in situ and in the laboratory. The main focus of this paper has been to study natural gas emissions representing extremely attractive surrogates for the study and prediction of the possible consequences of leakage from geological sequestration sites of anthropogenic CO 2 (i.e., the return to surface, potentially causing localised environmental problems). These include a comparison among three different Italian case histories: (i) the Solfatara crater (Phlegraean Fields caldera, southern Italy) is an ancient Roman spa. The area is characterised by intense and diffuse hydrothermal activity, testified by hot acidic mud pools, thermal springs and a large fumarolic field. Soil gas flux measurements show that the entire area discharges between 1200 and 1500 tons of CO 2 per day; (ii) the Panarea Island (Aeolian Islands, southern Italy) where a huge submarine volcanic-hydrothermal gas burst occurred in November, 2002. The submarine gas emissions chemically modified seawater causing a strong modification of the marine ecosystem. All of the collected gases are CO 2 -dominant (maximum value: 98.43 vol.%); (iii) the Tor Caldara area (Central Italy), located in a peripheral sector of the quiescent Alban Hills volcano, along the faults of the Ardea Basin transfer structure. The area is characterised by huge CO 2 degassing both from water and soil. Although the above mentioned areas do not represent a storage scenario, these sites do provide many opportunities to study near-surface processes and to test monitoring methodologies.

  15. Fluid geochemistry and soil gas fluxes (CO2-CH4-H2S) at a promissory Hot Dry Rock Geothermal System: The Acoculco caldera, Mexico

    Science.gov (United States)

    Peiffer, L.; Bernard-Romero, R.; Mazot, A.; Taran, Y. A.; Guevara, M.; Santoyo, E.

    2014-09-01

    The Acoculco caldera has been recognized by the Mexican Federal Electricity Company (CFE) as a Hot Dry Rock Geothermal System (HDR) and could be a potential candidate for developing an Enhanced Geothermal System (EGS). Apart from hydrothermally altered rocks, geothermal manifestations within the Acoculco caldera are scarce. Close to ambient temperature bubbling springs and soil degassing are reported inside the caldera while a few springs discharge warm water on the periphery of the caldera. In this study, we infer the origin of fluids and we characterize for the first time the soil degassing dynamic. Chemical and isotopic (δ18O-δD) analyses of spring waters indicate a meteoric origin and the dissolution of CO2 and H2S gases, while gas chemical and isotopic compositions (N2/He, 3He/4He, 13C, 15N) reveal a magmatic contribution with both MORB- and arc-type signatures which could be explained by an extension regime created by local and regional fault systems. Gas geothermometry results are in agreement with temperature measured during well drilling (260 °C-300 °C). Absence of well-developed water reservoir at depth impedes re-equilibration of gases upon surface. A multi-gas flux survey including CO2, CH4 and H2S measurements was performed within the caldera. Using the graphical statistical analysis (GSA) approach, CO2 flux measurements were classified in two populations. Population A, representing 95% of measured fluxes is characterized by low values (mean: 18 g m- 2 day- 1) while the remaining 5% fluxes belonging to Population B are much higher (mean: 5543 g m- 2 day- 1). This low degassing rate probably reflects the low permeability of the system, a consequence of the intense hydrothermal alteration observed in the upper 800 m of volcanic rocks. An attempt to interpret the origin and transport mechanism of these fluxes is proposed by means of flux ratios as well as by numerical modeling. Measurements with CO2/CH4 and CO2/H2S flux ratios similar to mass ratios

  16. Fumarole/plume and diffuse CO2 emission from Sierra Negra volcano, Galapagos archipelago

    Science.gov (United States)

    Padron, E.; Hernandez Perez, P. A.; Perez, N.; Theofilos, T.; Melian, G.; Barrancos, J.; Virgil, G.; Sumino, H.; Notsu, K.

    2009-12-01

    The active shield-volcano Sierra Negra is part of the Galapagos hotspot. Sierra Negra is the largest shield volcano of Isabela Island, hosting a 10 km diameter caldera. Ten historic eruptions have occurred and some involved a frequently visited east caldera rim fissure zone called Volcan Chico. The last volcanic event occurred in October 2005 and lasted for about a week, covering approximately twenty percent of the eastern caldera floor. Sierra Negra volcano has experienced some significant changes in the chemical composition of its volcanic gas discharges after the 2005 eruption. This volcanic event produced an important SO2 degassing that depleted the magmatic content of this gas. Not significant changes in the MORB and plume-type helium contribution were observed after the 2005 eruption, with a 65.5 % of MORB and 35.5 % of plume contribution. In 2006 a visible and diffuse gas emission study was performed at the summit of Sierra Negra volcano, Galapagos, to evaluate degassing rate from this volcanic system. Diffuse degassing at Sierra Negra was mainly confined in three different DDS: Volcan Chico, the southern inner margin of the caldera, and Mina Azufral. These areas showed also visible degassing, which indicates highly fractured areas where volcano-hydrothermal fluids migrate towards surface. A total fumarole/plume SO2 emission of 11 ± 2 td-1 was calculated by mini-DOAS ground-based measurements at Mina Azufral fumarolic area. Molar ratios of major volcanic gas components were also measured in-situ at Mina Azufral with a portable multisensor. The results showed H2S/SO2, CO2/SO2 and H2O/SO2 molar ratios of 0.41, 52.2 and 867.9, respectively. Multiplying the observed SO2 emission rate times the observed (gas)i/SO2 mass ratio we have estimated other volatiles emission rates. The results showed that H2O, CO2 and H2S emission rates from Sierra Negra are 562, 394, and 2.4 t d-1, respectively. The estimated total output of diffuse CO2 emission from the summit of

  17. Spatial variability in degassing at Erebus volcano, Antarctica

    Science.gov (United States)

    Ilanko, Tehnuka; Oppenheimer, Clive; Kyle, Philip; Burgisser, Alain

    2015-04-01

    Erebus volcano on Ross Island, Antarctica, hosts an active phonolitic lava lake, along with a number of persistently degassing vents in its summit crater. Flank degassing also occurs through ice caves and towers. The longevity of the lake, and its stable convection, have been the subject of numerous studies, including Fourier transform infrared (FTIR) spectroscopy of the lava lake. Two distinct gas compositions were previously identified in the main lava lake plume (Oppenheimer et al., 2009; 2011): a persistent 'conduit' gas with a more oxidised signature, ascribed to degassing through a permeable magma conduit; and a H2O- and SO2- enriched 'lake' composition that increases and decreases cyclically due to shallow degassing of incoming magma batches. During the past decade of annual field seasons on Erebus, gas compositions have been measured through FTIR spectroscopy at multiple sites around Erebus volcano, including flank degassing through an ice cave (Warren Cave). We present measurements from four such vents, and compare their compositions to those emitted from the main lava lake. Summit degassing involves variable proportions of H2O, CO2, CO, SO2, HF, HCl, OCS. Cyclicity is evident in some summit vents, but with signatures indicative of shallower magmatic degassing than that of the lava lake. By contrast, flank degassing at Warren Cave is dominated by H2O, CO2, and CH4. The spatial variability in gas compositions within the summit crater suggests an alternative origin for 'conduit' and 'lake' degassing to previous models that assume permeability in the main conduit. Rather, the two compositions observed in main lake degassing may be a result of decoupled 'conduit' gas and pulses of magma rising through discrete fractures before combining in the lake floor or the main plume. Smaller vents around the crater thus emit isolated 'lake' or 'conduit' compositions while their combined signature is observed in the lava lake. We suggest that this separation between gas

  18. Diffuse magmatic soil degassing at Soufriere of Guadeloupe, Antilles

    International Nuclear Information System (INIS)

    Allard, P.; Parello, F.

    1998-01-01

    A soil gas profiling made along the southern basis of Soufriere summit lave dome, in Guadeloupe, reveals the existence of diffuse emanations of magma-derived CO 2 in coincidence with a major volcanic (Ty) fault, where CO 2 concentrations at 70 cm depth in the ground reach 35-96 % and are associated with a thermal convective cell. Outside, a few 'cold' gaseous anomalies of volcanic origin (lack of methane) provide reliable conditions for continuous radon monitoring of soil degassing. (authors)

  19. Sea Ice as a Sink for CO2 and Biogeochemical Material: a Novel Sampling Method and Astrobiological Applications

    Science.gov (United States)

    Wilner, J.; Hofmann, A.; Hand, K. P.

    2017-12-01

    Accurately modelling the intensification of greenhouse gas effects in the polar regions ("polar amplification") necessitates a thorough understanding of the geochemical balance between atmospheric, sea ice, and oceanic layers. Sea ice is highly permeable to CO2 and therefore represents a major sink of oceanic CO2 in winter and of atmospheric CO2 in summer, sinks that are typically either poorly constrained in or fully absent from global climate models. We present a novel method for sampling both trapped and dissolved gases (CO2, CH4 and δ13CH4) in sea ice with a Picarro 2132-i Methane Analyzer, taking the following sampling considerations into account: minimization of water and air contamination, full headspace sampling, prevention of inadvertent sample bag double-puncturing, and ease of use. This method involves melting of vacuum-sealed ice cores to evacuate trapped gases to the headspace and sampling the headspace gas with a blunt needle sheathed by a beveled puncturing needle. A gravity catchment tube prevents input of dangerous levels of liquid water to the Picarro cavity. Subsequent ultrasonic degassing allows for dissolved gas measurement. We are in the process of using this method to sample gases trapped and dissolved in Arctic autumn sea ice cores and atmospheric samples collected during the 2016 Polarstern Expedition and during a May 2017 field campaign north of Barrow, Alaska. We additionally employ this method, together with inductively coupled plasma mass spectrometry (ICP-MS), to analyze the transfer of potential biogeochemical signatures of underlying hydrothermal plumes to sea ice. This has particular relevance to Europa and Enceladus, where hypothetical hydrothermal plumes may deliver seafloor chemicals to the overlying ice shell. Hence, we are presently investigating the entrainment of methane and other hydrothermal material in sea ice cores collected along the Gakkel Ridge that may serve as biosignatures of methanogenic organisms in seafloor

  20. Structural controls on diffuse degassing in the Las Cañadas caldera, Tenerife, Canary Islands

    Science.gov (United States)

    Galindo, I.; Soriano, C.; Martí, J.; Pérez, N.

    2003-04-01

    The Las Cañadas caldera is an elliptical depression located in the central part of the Tenerife Island. The active Teide stratovolcano stands in the centre of the depression, which is limited to the south by the caldera wall, up to 500 m high above the caldera floor. Mapping most of the caldera wall at 1:5000 has provided new insights on its stratigraphy, structure, and geological evolution. Three major ENE-WSW normal faults have been mapped on the caldera wall in the area comprised between El Llano de Ucanca and Los Azulejos, where an intense hydrothermal alteration affects the lower stratigraphic levels of the caldera wall. Hydrothermal alteration is rather distinctive in this area, showing bluish to greenish colours. Most of the phonolitic cone sheets and radial dykes of the caldera wall do not show distinctive hydrothermal features, as do show the phonolitic pyroclastic rocks and lavas of the lower parts of the caldera wall. This suggests the main episodes of dyke intrusion in the Las Cañadas caldera postdate hydrothermal alteration. ENE-WSW normal faults involve dyke swarms and rocks of the upper stratigraphic levels of the caldera wall, and show displacements of up to 100 m. Unfortunately the upper possible age of these faults is poorly constrained since no contact relationship has been observed between fault planes and the rocks of the uppermost stratigraphic levels of the caldera wall. The rocks of the caldera wall adjacent to the faults are intensely fractured at the macro and mesoscale. In addition to field mapping, a soil gas survey was carried out at the caldera depression. Soil CO2 efflux and H2 concentration were measured reaching values of 12 gm-2d-1 and 4 ppmV, respectively. Spatial distribution of these species showed that positive anomalies coincide with the surface expression of the three major faults and their adjacent intensely fractured zone. The high CO2 and H2 values and their coincidence with major normal faults suggests that degassing in

  1. Degassing a large LHe cryopump

    International Nuclear Information System (INIS)

    Denhoy, B.S.; Batzer, T.H.; Call, W.R.

    1977-01-01

    A method has been developed and successfully tested to degas a large LHe cryopump. Use of this method inhibits the normally excessive pressure rise during the degassing cycle when the degassing rate exceeds the external pumping capabilities of the system. A small appendage pump, installed close to the main cryopump, absorbs all the gas, as it is desorbed from the main cryopump, with no rise in the system pressure. The appendage pump can then be isolated from the main vacuum system and degassed at high pressure. We pumped 15 to 20 x 10 3 Torr . 1 of H 2 on a 1.25 m 2 panel. During the degassing cycle the system pressure never rose above 1 x 10 -4 Torr. In large vacuum systems for future fusion machines that contain cryopump panels as well as cryogenic magnets, this method is a unique and very useful tool. It will allow the degassing of cryopumps without affecting the temperature equilibrium of cryogenic magnets

  2. CO2 blood test

    Science.gov (United States)

    Bicarbonate test; HCO3-; Carbon dioxide test; TCO2; Total CO2; CO2 test - serum; Acidosis - CO2; Alkalosis - CO2 ... Many medicines can interfere with blood test results. Your health ... need to stop taking any medicines before you have this test. DO ...

  3. CO2 sequestration

    International Nuclear Information System (INIS)

    Favre, E.; Jammes, L.; Guyot, F.; Prinzhofer, A.; Le Thiez, P.

    2009-01-01

    This document presents the summary of a conference-debate held at the Academie des Sciences (Paris, France) on the topic of CO 2 sequestration. Five papers are reviewed: problems and solutions for the CO 2 sequestration; observation and surveillance of reservoirs; genesis of carbonates and geological storage of CO 2 ; CO 2 sequestration in volcanic and ultra-basic rocks; CO 2 sequestration, transport and geological storage: scientific and economical perspectives

  4. Carbon dioxide diffuse emission and thermal energy release from hydrothermal systems at Copahue-Caviahue Volcanic Complex (Argentina)

    Science.gov (United States)

    Chiodini, Giovanni; Cardellini, Carlo; Lamberti, María Clara; Agusto, Mariano; Caselli, Alberto; Liccioli, Caterina; Tamburello, Giancarlo; Tassi, Franco; Vaselli, Orlando; Caliro, Stefano

    2015-10-01

    The north-western sector of Caviahue caldera (Argentina), close to the active volcanic system of Copahue, is characterized by the presence of several hydrothermal sites that host numerous fumarolic emissions, anomalous soil diffuse degassing of CO2 and hot soils. In March 2014, measurements of soil CO2 fluxes in 5 of these sites (namely, Las Máquinas, Las Maquinitas I, Las Maquinitas II, Anfiteatro, and Termas de Copahue) allowed an estimation that 165 t of deeply derived CO2 is daily released. The gas source is likely related to a relatively shallow geothermal reservoir containing a single vapor phase as also suggested by both the geochemical data from the 3 deep wells drilled in the 1980s and gas geoindicators applied to the fumarolic discharges. Gas equilibria within the H-C-O gas system indicate the presence of a large, probably unique, single phase vapor zone at 200-210 °C feeding the hydrothermal manifestations of Las Máquinas, Las Maquinitas I and II and Termas de Copahue. A natural thermal release of 107 MW was computed by using CO2 as a tracer of the original vapor phase. The magmatic signature of the incondensable fumarolic gases, the wide expanse of the hydrothermal areas and the remarkable high amount of gas and heat released by fluid expulsion seem to be compatible with an active magmatic intrusion beneath this portion of the Caviahue caldera.

  5. Carbon flow from volcanic CO2 into soil microbial communities of a wetland mofette

    DEFF Research Database (Denmark)

    Beulig, Felix

    2015-01-01

    Effects of extremely high carbon dioxide (CO2) concentrations on soil microbial communities and associated processes are largely unknown. We studied a wetland area affected by spots of subcrustal CO2 degassing (mofettes) with focus on anaerobic autotrophic methanogenesis and acetogenesis because ...

  6. CO2 diffuse emission from maar lake: An example in Changbai volcanic field, NE China

    Science.gov (United States)

    Sun, Yutao; Guo, Zhengfu; Liu, Jiaqi; Du, Jianguo

    2018-01-01

    Numerous maars and monogenetic volcanic cones are distributed in northeast China, which are related to westward deep subduction of the Pacific Ocean lithosphere, comprising a significant part of the "Pacific Ring of Fire". It is well known that diffuse CO2 emissions from monogenetic volcanoes, including wet (e.g., maar lake) and dry degassing systems (e.g., soil diffuse emission, fault degassing, etc.), may contribute to budget of globally nature-derived greenhouse gases. However, their relationship between wet (e.g., maar lake) and concomitant dry degassing systems (e.g., soil diffuse emission, fault degassing, etc.) related to monogenetic volcanic field is poorly understood. Yuanchi maar, one of the typical monogenetic volcanic systems, is located on the eastern flank of Tianchi caldera in Changbai volcanic field of northeast China, which displays all of three forms of CO2 degassing including the maar lake, soil micro-seepage and fault degassing. Measurements of efflux of CO2 diffusion from the Yuanchi maar system (YMS) indicate that the average values of CO2 emissions from soil micro-seepage, fault degassing and water-air interface diffusion are 24.3 ± 23.3 g m- 2 d- 1, 39.2 ± 22.4 g m- 2 d- 1 and 2.4 ± 1.1 g m- 2 d- 1, respectively. The minimum output of CO2 diffuse emission from the YMS to the atmosphere is about 176.1 ± 88.3 ton/yr, of which 80.4% results from the dry degassing system. Degassing from the fault contributes to the most of CO2 emissions in all of the three forms of degassing in the YMS. Contributions of mantle, crust, air and organic CO2 to the soil gas are 0.01-0.10%, 10-20%, 32-36% and 48-54%, respectively, which are quantitatively constrained by a He-C isotope coupling calculation model. We propose that CO2 exsolves from the upper mantle melting beneath the Tianchi caldera, which migrates to the crustal magma chamber and further transports to the surface of YMS along the deep fault system. During the transportation processes, the emission

  7. Hydrothermal Processes

    Science.gov (United States)

    German, C. R.; von Damm, K. L.

    2003-12-01

    (after C. A. Stein and S. Stein, 1994). The first geochemical evidence for the existence of hydrothermal vents on the ocean floor came in the mid-1960s when investigations in the Red Sea revealed deep basins filled with hot, salty water (40-60 °C) and underlain by thick layers of metal-rich sediment (Degens and Ross, 1969). Because the Red Sea represents a young, rifting, ocean basin it was speculated that the phenomena observed there might also prevail along other young MOR spreading centers. An analysis of core-top sediments from throughout the world's oceans ( Figure 2) revealed that such metalliferous sediments did, indeed, appear to be concentrated along the newly recognized global ridge crest (Boström et al., 1969). Another early indication of hydrothermal activity came from the detection of plumes of excess 3He in the Pacific Ocean Basin (Clarke et al., 1969) - notably the >2,000 km wide section in the South Pacific ( Lupton and Craig, 1981) - because 3He present in the deep ocean could only be sourced through some form of active degassing of the Earth's interior, at the seafloor. (62K)Figure 2. Global map of the (Al+Fe+Mn):Al ratio for surficial marine sediments. Highest ratios mimic the trend of the global MOR axis (after Boström et al., 1969). One area where early heat-flow studies suggested hydrothermal activity was likely to occur was along the Galapagos Spreading Center in the eastern equatorial Pacific Ocean (Anderson and Hobart, 1976). In 1977, scientists diving at this location found hydrothermal fluids discharging chemically altered seawater from young volcanic seafloor at elevated temperatures up to 17 °C ( Edmond et al., 1979). Two years later, the first high-temperature (380±30 °C) vent fluids were found at 21° N on the East Pacific Rise (EPR) (Spiess et al., 1980) - with fluid compositions remarkably close to those predicted from the lower-temperature Galapagos findings ( Edmond et al., 1979). Since that time, hydrothermal activity has been

  8. CO2NNIE

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Andersen, Ove; Lewis-Kelham, Edwin

    2015-01-01

    We propose a system for calculating the personalized annual fuel consumption and CO2 emissions from transportation. The system, named CO2NNIE, estimates the fuel consumption on the fastest route between the frequent destinations of the user. The travel time and fuel consumption estimated are based......% of the actual fuel consumption (4.6% deviation on average). We conclude, that the system provides new detailed information on CO2 emissions and fuel consumption for any make and model....

  9. Anomalous changes of diffuse CO_{2} emission and seismic activity at Teide volcano, Tenerife, Canary Islands

    Science.gov (United States)

    García-Hernández, Rubén; Melián, Gladys; D'Auria, Luca; Asensio-Ramos, María; Alonso, Mar; Padilla, Germán D.; Rodríguez, Fátima; Padrón, Eleazar; Barrancos, José; García-Merino, Marta; Amonte, Cecilia; Pérez, Aarón; Calvo, David; Hernández, Pedro A.; Pérez, Nemesio M.

    2017-04-01

    Tenerife (2034 km2) is the largest of the Canary Islands and hosts four main active volcanic edifices: three volcanic rifts and a central volcanic complex, Las Cañadas, which is characterized by the eruption of differentiated magmas. Laying inside Las Cañadas a twin stratovolcanoes system, Pico Viejo and Teide, has been developed. Although there are no visible gas emanations along the volcanic rifts of Tenerife, the existence of a volcanic-hydrothermal system beneath Teide volcano is suggested by the occurrence of a weak fumarolic system, steamy ground and high rates of diffuse CO2 degassing all around the summit cone of Teide. Soil CO2 efflux surveys have been performed at the summit crater of Teide volcano since 1999, to determine the diffuse CO2 emission from the summit crater and to evaluate the temporal variations of CO2 efflux and their relationships with seismic-volcanic activity. Soil CO2 efflux and soil temperature have been always measured at the same 38 observation sites homogeneously distributed within an area of about 6,972 m2 inside the summit crater. Soil CO2 diffuse effluxes were estimated according to the accumulation chamber method by means of a non-dispersive infrared (NDIR) LICOR-820 CO2 analyzer. Historical seismic activity in Tenerife has been characterized by low- to moderate-magnitude events (M de Canarias (INVOLCAN) registered an earthquake of M 2.5 located in the vertical of Teide volcano with a depth of 6.6 km. It was the strongest earthquake located inside Cañadas caldera since 2004. Between October 11 and December 13, 2016, a continuous increase on the diffuse CO2 emission was registered, from 21.3 ± 2.0 to 101.7 ± 20.7 t d-1, suggesting the occurrence of future increase in the seismic-volcanic activity. In fact, this precursory signal preceded the occurrence of the 2.5 seismic event and no significant horizontal and vertical displacements were registered by the Canary GPS network belonged to INVOLCAN. This seismic event was

  10. The 2006 Eruption of Raoul Volcano (Kermadecs): A Phreato-magmatic Event From a Hydrothermally-Sealed Volcanic Conduit System.

    Science.gov (United States)

    Christenson, B. W.; Reyes, A. G.; Werner, C. A.

    2006-12-01

    The March 17, 2006 eruption from Raoul volcano (Kermadec Islands, NZ), which tragically claimed the life of NZ Department of Conservation staff member Mark Kearney, is being interpreted as a magmatic-hydrothermal event triggered by shaking associated with regional earthquake swarm activity. Although the eruption released ca. 200 T of SO2, thus confirming its magmatic nature, it occurred without significant precursory volcanic seismicity, and without any of the precursory responses of the volcanic hydrothermal system which were observed prior to the last eruption in 1964. Raoul Island has a long and varied eruption history dating back > 1.4 ma, and has been hydrothermally active throughout historic time. Present day fumarolic and hotspring discharges within Raoul caldera point to the existence of a small but well established, mixed meteoric - seawater hydrothermal system within the volcano. Magmatic signatures are apparent in fumarolic gas discharges, but are heavily masked by their interaction with hydrothermal system fluids (eg. near complete scrubbing of sulphur and halogen gases from the boiling point fumarolic discharges). A diffuse degassing study conducted in 2004 revealed that ca. 80 T/d CO2 is passively discharged from the volcano, suggesting that ongoing (albeit low level) convective degassing of magma occurs at depth. Interestingly, vent locations from the 2006 eruption correspond to areas of relatively low CO2 discharge on the crater floor in 2004. This, in conjunction with the preliminary findings of abundant hydrothermal mineralisation (calcite, anhydrite, quartz) in eruption ejecta, suggests that the main volcanic conduits had become effectively sealed during the interval since the last eruption. Calcite-hosted fluid inclusions are CO2 clathrate-bearing, and have relatively low homogenisation temperatures (165-180 °C), suggesting that the seal environment was both gas-charged and shallowly seated (< 200 m). Shaking associated with the regional

  11. Soil degassing at the Los Humeros geothermal field (Mexico)

    Science.gov (United States)

    Peiffer, Loïc; Carrasco-Núñez, Gerardo; Mazot, Agnès; Villanueva-Estrada, Ruth Esther; Inguaggiato, Claudio; Bernard Romero, Rubén; Rocha Miller, Roberto; Hernández Rojas, Javier

    2018-05-01

    The Los Humeros geothermal field is the third most important producer of geothermal electricity (70 MW) in Mexico. Geothermal fluids are hosted in fractured andesitic lavas and mostly consist of high enthalpy steam with limited water content (vapor fraction > 0.9). Despite the high reservoir temperature ( 300-400 °C), thermal manifestations at the surface are scarce and locally appear as steaming grounds, weak steam vents and advanced argillic alteration. Geothermal fluid upflow from the reservoir towards the surface is limited by welded ignimbrite deposits that act as a low-permeability barrier. In this study, we present the first measurements of CO2, CH4 and H2S degassing rates from the soil performed at Los Humeros. Flux measurements were complemented with δ13C composition of degassing CO2 and soil temperatures to discuss gas origin and thermal anomalies. We measured high soil degassing rates (up to 7530 g m-2 d-1 CO2, 33 g m-2 d-1 CH4 and 22 g m-2 d-1 H2S) in three localized areas (Humeros North - HN, Humeros South - HS and Xalapazco - XA) as well as high soil temperatures reaching the boiling temperature at the local altitude (90.6 °C). The particular location of these three areas suggests that the steam-dominated reservoir degases to the surface through permeable faults crossing the ignimbritic deposits. The remaining surveyed areas are characterized by weak CO2 fluxes (≤44 g m-2 d-1), non-detectable CH4 and H2S fluxes, and lower soil temperatures (5-21 °C). The compositions in δ13CCO2 from HN-HS-XA areas (δ13CCO2 = -7.94 to -2.73‰) reflect a magmatic source with some possible contribution from the sedimentary basement, as well as fractionation induced by boiling and CO2 dissolution in shallow water bodies. We also discuss the processes causing the spread in CO2/CH4 flux ratios. Finally, we estimate the heat output from the three high degassing areas to a value of 16.4 MWt.

  12. CO2-laser fusion

    International Nuclear Information System (INIS)

    Stark, E.E. Jr.

    1978-01-01

    The basic concept of laser fusion is described, with a set of requirements on the laser system. Systems and applications concepts are presented and discussed. The CO 2 laser's characteristics and advantages for laser fusion are described. Finally, technological issues in the development of CO 2 laser systems for fusion applications are discussed

  13. Carbon dioxide degassing at the groundwater-stream-atmosphere interface: isotopic equilibration and hydrological mass balance in a sandy watershed

    Science.gov (United States)

    Deirmendjian, Loris; Abril, Gwenaël

    2018-03-01

    Streams and rivers emit significant amounts of CO2 and constitute a preferential pathway of carbon transport from terrestrial ecosystems to the atmosphere. However, the estimation of CO2 degassing based on the water-air CO2 gradient, gas transfer velocity and stream surface area is subject to large uncertainties. Furthermore, the stable isotope signature of dissolved inorganic carbon (δ13C-DIC) in streams is strongly impacted by gas exchange, which makes it a useful tracer of CO2 degassing under specific conditions. For this study, we characterized the annual transfers of dissolved inorganic carbon (DIC) along the groundwater-stream-river continuum based on DIC concentrations, stable isotope composition and measurements of stream discharges. We selected a homogeneous, forested and sandy lowland watershed as a study site, where the hydrology occurs almost exclusively through drainage of shallow groundwater (no surface runoff). We observed the first general spatial pattern of decreases in pCO2 and DIC and an increase in δ13C-DIC from groundwater to stream orders 1 and 2, which was due to the experimentally verified faster degassing of groundwater 12C-DIC compared to 13C-DIC. This downstream enrichment in 13C-DIC could be modelled by simply considering the isotopic equilibration of groundwater-derived DIC with the atmosphere during CO2 degassing. A second spatial pattern occurred between stream orders 2 and 4, consisting of an increase in the proportion of carbonate alkalinity to the DIC accompanied by the enrichment of 13C in the stream DIC, which was due to the occurrence of carbonate rock weathering downstream. We could separate the contribution of these two processes (gas exchange and carbonate weathering) in the stable isotope budget of the river network. Thereafter, we built a hydrological mass balance based on drainages and the relative contribution of groundwater in streams of increasing order. After combining with the dissolved CO2 concentrations, we

  14. Outsourcing CO2 Emissions

    Science.gov (United States)

    Davis, S. J.; Caldeira, K. G.

    2009-12-01

    CO2 emissions from the burning of fossil fuels are the primary cause of global warming. Much attention has been focused on the CO2 directly emitted by each country, but relatively little attention has been paid to the amount of emissions associated with consumption of goods and services in each country. This consumption-based emissions inventory differs from the production-based inventory because of imports and exports of goods and services that, either directly or indirectly, involved CO2 emissions. Using the latest available data and reasonable assumptions regarding trans-shipment of embodied carbon through third-party countries, we developed a global consumption-based CO2 emissions inventory and have calculated associated consumption-based energy and carbon intensities. We find that, in 2004, 24% of CO2 emissions are effectively outsourced to other countries, with much of the developed world outsourcing CO2 emissions to emerging markets, principally China. Some wealthy countries, including Switzerland and Sweden, outsource over half of their consumption-based emissions, with many northern Europeans outsourcing more than three tons of emissions per person per year. The United States is both a big importer and exporter of emissions embodied in trade, outsourcing >2.6 tons of CO2 per person and at the same time as >2.0 tons of CO2 per person are outsourced to the United States. These large flows indicate that CO2 emissions embodied in trade must be taken into consideration when considering responsibility for increasing atmospheric greenhouse gas concentrations.

  15. Coolant degassing device for PWR type reactors

    International Nuclear Information System (INIS)

    Kita, Kaoru; Takezawa, Kazuaki; Minemoto, Masaki.

    1982-01-01

    Purpose: To efficiently decrease the rare gas concentration in primary coolants, as well as shorten the degassing time required for the periodical inspection in the waste gas processing system of a PWR type reactor. Constitution: Usual degassing method by supplying hydrogen or nitrogen to a volume control tank is replaced with a method of utilizing a degassing tower (method of flowing down processing liquid into the filled tower from above while uprising streams from the bottom of the tower thereby degassing the gases dissolved in the liquid into the steams). The degassing tower is combined with a hydrogen separator or hydrogen recombiner to constitute a waste gas processing system. (Ikeda, J.)

  16. Volcanic degassing at Somma-Vesuvio (Italy) inferred by chemical and isotopic signatures of groundwater

    International Nuclear Information System (INIS)

    Caliro, S.; Chiodini, G.; Avino, R.; Cardellini, C.; Frondini, F.

    2005-01-01

    A geochemical model is proposed for water evolution at Somma-Vesuvio, based on the chemical and isotopic composition of groundwaters, submarine gas emission and chemical composition of the dissolved gases. The active degassing processes, present in the highest part of the volcano edifice, strongly influence the groundwater evolution. The geological-volcanological setting of the volcano forces the waters infiltrating at Somma-Vesuvio caldera, enriched in volcanic gases, to flow towards the southern sector to an area of high pCO 2 groundwaters. Reaction path modelling applied to this conceptual model, involving gas-water-rock interaction, highlights an intense degassing process in the aquifer controlling the chemical and isotopic composition of dissolved gases, total dissolved inorganic C (TDIC) and submarine gas emission. Mapping of TDIC shows a unique area of high values situated SSE of Vesuvio volcano with an average TDIC value of 0.039 mol/L, i.e., one order of magnitude higher than groundwaters from other sectors of the volcano. On the basis of TDIC values, the amount of CO 2 transported by Vesuvio groundwaters was estimated at about 150 t/d. This estimate does not take into account the fraction of gas loss by degassing, however, it represents a relevant part of the CO 2 emitted in this quiescent period by the Vesuvio volcanic system, being of the same order of magnitude as the CO 2 diffusely degassed from the crater area

  17. Increasing CO2 flux at Pisciarelli, Campi Flegrei, Italy

    Directory of Open Access Journals (Sweden)

    M. Queißer

    2017-09-01

    Full Text Available The Campi Flegrei caldera is located in the metropolitan area of Naples (Italy and has been undergoing different stages of unrest since 1950, evidenced by episodes of significant ground uplift followed by minor subsidence, increasing and fluctuating emission strengths of water vapor and CO2 from fumaroles, and periodic seismic crises. We deployed a scanning laser remote-sensing spectrometer (LARSS that measured path-integrated CO2 concentrations in the Pisciarelli area in May 2017. The resulting mean CO2 flux is 578 ± 246 t d−1. Our data suggest a significant increase in CO2 flux at this site since 2015. Together with recent geophysical observations, this suggests a greater contribution of the magmatic source to the degassing and/or an increase in permeability at shallow levels. Thanks to the integrated path soundings, LARSS may help to give representative measurements from large regions containing different CO2 sources, including fumaroles, low-temperature vents, and degassing soils, helping to constrain the contribution of deep gases and their migration mechanisms towards the surface.

  18. CO2 chemical valorization

    International Nuclear Information System (INIS)

    Kerlero De Rosbo, Guillaume; Rakotojaona, Loic; Bucy, Jacques de; Clodic, Denis; Roger, Anne-Cecile; El Khamlichi, Aicha; Thybaud, Nathalie; Oeser, Christian; Forti, Laurent; Gimenez, Michel; Savary, David; Amouroux, Jacques

    2014-07-01

    Facing global warming, different technological solutions exist to tackle carbon dioxide (CO 2 ) emissions. Some inevitable short term emissions can be captured so as to avoid direct emissions into the atmosphere. This CO 2 must then be managed and geological storage seems to currently be the only way of dealing with the large volumes involved. However, this solution faces major economic profitability and societal acceptance challenges. In this context, alternative pathways consisting in using CO 2 instead of storing it do exist and are generating growing interest. This study ordered by the French Environment and Energy Management Agency (ADEME), aims at taking stock of the different technologies used for the chemical conversion of CO 2 in order to have a better understanding of their development potential by 2030, of the conditions in which they could be competitive and of the main actions to be implemented in France to foster their emergence. To do this, the study was broken down into two main areas of focus: The review and characterization of the main CO 2 chemical conversion routes for the synthesis of basic chemical products, energy products and inert materials. This review includes a presentation of the main principles underpinning the studied routes, a preliminary assessment of their performances, advantages and drawbacks, a list of the main R and D projects underway, a focus on emblematic projects as well as a brief analysis of the markets for the main products produced. Based on these elements, 3 routes were selected from among the most promising by 2030 for an in-depth modelling and assessment of their energy, environmental and economic performances. The study shows that the processes modelled do have favorable CO 2 balances (from 1 to 4 t-CO 2 /t-product) and effectively constitute solutions to reduce CO 2 emissions, despite limited volumes of CO 2 in question. Moreover, the profitability of certain solutions will remain difficult to reach, even with an

  19. Non-Volcanic release of CO2 in Italy: quantification, conceptual models and gas hazard

    Science.gov (United States)

    Chiodini, G.; Cardellini, C.; Caliro, S.; Avino, R.

    2011-12-01

    Central and South Italy are characterized by the presence of many reservoirs naturally recharged by CO2 of deep provenance. In the western sector, the reservoirs feed hundreds of gas emissions at the surface. Many studies in the last years were devoted to (i) elaborating a map of CO2 Earth degassing of the region; (ii) to asses the gas hazard; (iii) to develop methods suitable for the measurement of the gas fluxes from different types of emissions; (iv) to elaborate the conceptual model of Earth degassing and its relation with the seismic activity of the region and (v) to develop physical numerical models of CO2 air dispersion. The main results obtained are: 1) A general, regional map of CO2 Earth degassing in Central Italy has been elaborated. The total flux of CO2 in the area has been estimated in ~ 10 Mt/a which are released to the atmosphere trough numerous dangerous gas emissions or by degassing spring waters (~ 10 % of the CO2 globally estimated to be released by the Earth trough volcanic activity). 2) An on line, open access, georeferenced database of the main CO2 emissions (~ 250) was settled up (http://googas.ov.ingv.it). CO2 flux > 100 t/d characterise 14% of the degassing sites while CO2 fluxes from 100 t/d to 10 t/d have been estimated for about 35% of the gas emissions. 3) The sites of the gas emissions are not suitable for life: the gas causes many accidents to animals and people. In order to mitigate the gas hazard a specific model of CO2 air dispersion has been developed and applied to the main degassing sites. A relevant application regarded Mefite d'Ansanto, southern Apennines, which is the largest natural emission of low temperature CO2 rich gases, from non-volcanic environment, ever measured in the Earth (˜2000 t/d). Under low wind conditions, the gas flows along a narrow natural channel producing a persistent gas river which has killed over a period of time many people and animals. The application of the physical numerical model allowed us to

  20. CO2 cycle

    Science.gov (United States)

    Titus, Timothy N.; Byrne, Shane; Colaprete, Anthony; Forget, Francois; Michaels, Timothy I.; Prettyman, Thomas H.

    2017-01-01

    This chapter discusses the use of models, observations, and laboratory experiments to understand the cycling of CO2 between the atmosphere and seasonal Martian polar caps. This cycle is primarily controlled by the polar heat budget, and thus the emphasis here is on its components, including solar and infrared radiation, the effect of clouds (water- and CO2-ice), atmospheric transport, and subsurface heat conduction. There is a discussion about cap properties including growth and regression rates, albedos and emissivities, grain sizes and dust and/or water-ice contamination, and curious features like cold gas jets and araneiform (spider-shaped) terrain. The nature of the residual south polar cap is discussed as well as its long-term stability and ability to buffer atmospheric pressures. There is also a discussion of the consequences of the CO2 cycle as revealed by the non-condensable gas enrichment observed by Odyssey and modeled by various groups.

  1. CO2-strategier

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard

    2008-01-01

    I 2007 henvendte Lyngby-Taarbæk kommunens Agenda 21 koordinator sig til Videnskabsbutikken og spurgte om der var interesse for at samarbejde om CO2-strategier. Da Videnskabsbutikken DTU er en åben dør til DTU for borgerne og deres organisationer, foreslog Videnskabsbutikken DTU at Danmarks...

  2. CO2-neutral fuels

    Directory of Open Access Journals (Sweden)

    Goede A. P. H.

    2015-01-01

    Full Text Available The need for storage of renewable energy (RE generated by photovoltaic, concentrated solar and wind arises from the fact that supply and demand are ill-matched both geographically and temporarily. This already causes problems of overcapacity and grid congestion in countries where the fraction of RE exceeds the 20% level. A system approach is needed, which focusses not only on the energy source, but includes conversion, storage, transport, distribution, use and, last but not least, the recycling of waste. Furthermore, there is a need for more flexibility in the energy system, rather than relying on electrification, integration with other energy systems, for example the gas network, would yield a system less vulnerable to failure and better adapted to requirements. For example, long-term large-scale storage of electrical energy is limited by capacity, yet needed to cover weekly to seasonal demand. This limitation can be overcome by coupling the electricity net to the gas system, considering the fact that the Dutch gas network alone has a storage capacity of 552 TWh, sufficient to cover the entire EU energy demand for over a month. This lecture explores energy storage in chemicals bonds. The focus is on chemicals other than hydrogen, taking advantage of the higher volumetric energy density of hydrocarbons, in this case methane, which has an approximate 3.5 times higher volumetric energy density. More importantly, it allows the ready use of existing gas infrastructure for energy storage, transport and distribution. Intermittent wind electricity generated is converted into synthetic methane, the Power to Gas (P2G scheme, by splitting feedstock CO2 and H2O into synthesis gas, a mixture of CO and H2. Syngas plays a central role in the synthesis of a range of hydrocarbon products, including methane, diesel and dimethyl ether. The splitting is accomplished by innovative means; plasmolysis and high-temperature solid oxygen electrolysis. A CO2-neutral fuel

  3. Leakage and Seepage of CO2 from Geologic Carbon Sequestration Sites: CO2 Migration into Surface Water

    International Nuclear Information System (INIS)

    Oldenburg, Curt M.; Lewicki, Jennifer L.

    2005-01-01

    Geologic carbon sequestration is the capture of anthropogenic carbon dioxide (CO 2 ) and its storage in deep geologic formations. One of the concerns of geologic carbon sequestration is that injected CO 2 may leak out of the intended storage formation, migrate to the near-surface environment, and seep out of the ground or into surface water. In this research, we investigate the process of CO 2 leakage and seepage into saturated sediments and overlying surface water bodies such as rivers, lakes, wetlands, and continental shelf marine environments. Natural CO 2 and CH 4 fluxes are well studied and provide insight into the expected transport mechanisms and fate of seepage fluxes of similar magnitude. Also, natural CO 2 and CH 4 fluxes are pervasive in surface water environments at levels that may mask low-level carbon sequestration leakage and seepage. Extreme examples are the well known volcanic lakes in Cameroon where lake water supersaturated with respect to CO 2 overturned and degassed with lethal effects. Standard bubble formation and hydrostatics are applicable to CO 2 bubbles in surface water. Bubble-rise velocity in surface water is a function of bubble size and reaches a maximum of approximately 30 cm s -1 at a bubble radius of 0.7 mm. Bubble rise in saturated porous media below surface water is affected by surface tension and buoyancy forces, along with the solid matrix pore structure. For medium and fine grain sizes, surface tension forces dominate and gas transport tends to occur as channel flow rather than bubble flow. For coarse porous media such as gravels and coarse sand, buoyancy dominates and the maximum bubble rise velocity is predicted to be approximately 18 cm s -1 . Liquid CO 2 bubbles rise slower in water than gaseous CO 2 bubbles due to the smaller density contrast. A comparison of ebullition (i.e., bubble formation) and resulting bubble flow versus dispersive gas transport for CO 2 and CH 4 at three different seepage rates reveals that

  4. CO2 flowrate calculator

    International Nuclear Information System (INIS)

    Carossi, Jean-Claude

    1969-02-01

    A CO 2 flowrate calculator has been designed for measuring and recording the gas flow in the loops of Pegase reactor. The analog calculator applies, at every moment, Bernoulli's formula to the values that characterize the carbon dioxide flow through a nozzle. The calculator electronics is described (it includes a sampling calculator and a two-variable function generator), with its amplifiers, triggers, interpolator, multiplier, etc. Calculator operation and setting are presented

  5. Carbon flow from volcanic CO2 into soil microbial communities of a wetland mofette

    DEFF Research Database (Denmark)

    Beulig, Felix

    2015-01-01

    Effects of extremely high carbon dioxide (CO2) concentrations on soil microbial communities and associated processes are largely unknown. We studied a wetland area affected by spots of subcrustal CO2 degassing (mofettes) with focus on anaerobic autotrophic methanogenesis and acetogenesis because ......2-induced geochemical changes promoted anaerobic and acidophilic organisms and altered carbon turnover in affected soils.......Effects of extremely high carbon dioxide (CO2) concentrations on soil microbial communities and associated processes are largely unknown. We studied a wetland area affected by spots of subcrustal CO2 degassing (mofettes) with focus on anaerobic autotrophic methanogenesis and acetogenesis because...... the pore gas phase was largely hypoxic. Compared with a reference soil, the mofette was more acidic (ΔpH ~0.8), strongly enriched in organic carbon (up to 10 times), and exhibited lower prokaryotic diversity. It was dominated by methanogens and subdivision 1 Acidobacteria, which likely thrived under stable...

  6. Hydrothermal systems and volcano geochemistry

    Science.gov (United States)

    Fournier, R.O.

    2007-01-01

    The upward intrusion of magma from deeper to shallower levels beneath volcanoes obviously plays an important role in their surface deformation. This chapter will examine less obvious roles that hydrothermal processes might play in volcanic deformation. Emphasis will be placed on the effect that the transition from brittle to plastic behavior of rocks is likely to have on magma degassing and hydrothermal processes, and on the likely chemical variations in brine and gas compositions that occur as a result of movement of aqueous-rich fluids from plastic into brittle rock at different depths. To a great extent, the model of hydrothermal processes in sub-volcanic systems that is presented here is inferential, based in part on information obtained from deep drilling for geothermal resources, and in part on the study of ore deposits that are thought to have formed in volcanic and shallow plutonic environments.

  7. Update estimate emissions degassing inland tank vessels

    Energy Technology Data Exchange (ETDEWEB)

    De Buck, A.; Hoen, M. ' t; Den Boer, E.

    2013-11-15

    At the exchange of cargos of petroleum or chemical products, ships can be degassed, resulting in emissions of VOCs (volatile organic compounds). CE Delft investigated the current size of degassing in the Netherlands. Results can serve as a basis for feasible and effective policies.

  8. CO2 laser development

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    The research and development programs on high-energy, short-pulse CO 2 lasers were begun at LASL in 1969. Three large systems are now either operating or are being installed. The Single-Beam System (SBS), a four-stage prototype, was designed in 1971 and has been in operation since 1973 with an output energy of 250 J in a 1-ns pulse with an on-target intensity of 3.5 x 10 14 W/cm 2 . The Dual-Beam System (DBS), now in the final stages of electrical and optical checkout, will provide about ten times more power for two-beam target irradiation experiments. Four such dual-beam modules are being installed in the Laser-Fusion Laboratory to provide an Eight-Beam System (EBS) scheduled for operation at the 5- to 10-TW level in 1977. A fourth system, a 100- to 200-TW CO 2 laser, is being designed for the High-Energy Gas Laser Facility (HEGLF) program

  9. Mantle to surface degassing of alkalic magmas at Erebus volcano, Antarctica

    Science.gov (United States)

    Oppenheimer, C.; Moretti, R.; Kyle, P.R.; Eschenbacher, A.; Lowenstern, J. B.; Hervig, R.L.; Dunbar, N.W.

    2011-01-01

    Continental intraplate volcanoes, such as Erebus volcano, Antarctica, are associated with extensional tectonics, mantle upwelling and high heat flow. Typically, erupted magmas are alkaline and rich in volatiles (especially CO2), inherited from low degrees of partial melting of mantle sources. We examine the degassing of the magmatic system at Erebus volcano using melt inclusion data and high temporal resolution open-path Fourier transform infrared (FTIR) spectroscopic measurements of gas emissions from the active lava lake. Remarkably different gas signatures are associated with passive and explosive gas emissions, representative of volatile contents and redox conditions that reveal contrasting shallow and deep degassing sources. We show that this unexpected degassing signature provides a unique probe for magma differentiation and transfer of CO2-rich oxidised fluids from the mantle to the surface, and evaluate how these processes operate in time and space. Extensive crystallisation driven by CO2 fluxing is responsible for isobaric fractionation of parental basanite magmas close to their source depth. Magma deeper than 4kbar equilibrates under vapour-buffered conditions. At shallower depths, CO2-rich fluids accumulate and are then released either via convection-driven, open-system gas loss or as closed-system slugs that ascend and result in Strombolian eruptions in the lava lake. The open-system gases have a reduced state (below the QFM buffer) whereas the closed-system gases preserve their deep oxidised signatures (close to the NNO buffer). ?? 2011 Elsevier B.V.

  10. Simulation of CO2–water–rock interactions on geologic CO2 sequestration under geological conditions of China

    International Nuclear Information System (INIS)

    Wang, Tianye; Wang, Huaiyuan; Zhang, Fengjun; Xu, Tianfu

    2013-01-01

    Highlights: • We determined the feasibilities of geologic CO 2 sequestration in China. • We determined the formation of gibbsite suggested CO 2 can be captured by rocks. • We suggested the mechanisms of CO 2 –water–rock interactions. • We found the corrosion and dissolution of the rock increased as temperature rose. -- Abstract: The main purpose of this study focused on the feasibility of geologic CO 2 sequestration within the actual geological conditions of the first Carbon Capture and Storage (CCS) project in China. This study investigated CO 2 –water–rock interactions under simulated hydrothermal conditions via physicochemical analyses and scanning electron microscopy (SEM). Mass loss measurement and SEM showed that corrosion of feldspars, silica, and clay minerals increased with increasing temperature. Corrosion of sandstone samples in the CO 2 -containing fluid showed a positive correlation with temperature. During reaction at 70 °C, 85 °C, and 100 °C, gibbsite (an intermediate mineral product) formed on the sample surface. This demonstrated mineral capture of CO 2 and supported the feasibility of geologic CO 2 sequestration. Chemical analyses suggested a dissolution–reprecipitation mechanism underlying the CO 2 –water–rock interactions. The results of this study suggested that mineral dissolution, new mineral precipitation, and carbonic acid formation-dissociation are closely interrelated in CO 2 –water–rock interactions

  11. CO2 Laser Market

    Science.gov (United States)

    Simonsson, Samuel

    1989-03-01

    It gives me a great deal of pleasure to introduce our final speaker of this morning's session for two reasons: First of all, his company has been very much in the news not only in our own community but in the pages of Wall Street Journal and in the world economic press. And, secondly, we would like to welcome him to our shores. He is a temporary resident of the United States, for a few months, forsaking his home in Germany to come here and help with the start up of a new company which we believe, probably, ranks #1 as the world supplier of CO2 lasers now, through the combination of former Spectra Physics Industrial Laser Division and Rofin-Sinar GMBH. Samuel Simonsson is the Chairman of the Board of Rofin-Sinar, Inc., here in the U.S. and managing director of Rofin-Sinar GMBH. It is a pleasure to welcome him.

  12. Development of a prototype for dissolved CO2 rapid measurement and preliminary tests

    Science.gov (United States)

    Li, Meng; Guo, Jinjia; Zhang, Zhihao; Luo, Zhao; Qin, Chuan; Zheng, Ronger

    2017-10-01

    The measurements of dissolved CO2 in seawater is of great significance for the study of global carbon cycle. At present, the commercial sensors used for dissolved CO2 measurements are mostly equipped with permeable membranes for the purpose of gas-liquid separation, with the advantages of easy operation, low cost, etc.. However, most of these devices measure CO2 after reaching gas equilibrium, so it takes a few minutes to respond, which limited its applications in rapid measurements. In this paper, a set of prototype was developed for the rapid measurements of dissolved CO2. The system was built basing the direct absorption TDLAS. To detect the CO2 absorption line located at 4991.26 cm-1 , a fiber-coupled DFB laser operating at 2004 nm was selected as the light source. A Herriott type multi-pass cavity with an effective optical path length of 10 m and an inner volume of 90 mL was used for absorption measurements. A detection limit of 26 μatm can be obtained with this compact cavity. To realize the rapid measurements of dissolved CO2, a degasser with high degassing rate was necessary. A hollow fiber membrane with a large permeable area used in this paper can achieve degassing rate up to 2.88 kPa/min. Benefitted from the high degassing rate of the degasser and high sensitivity of the compact TDLAS system, a rapid measurement of dissolved CO2 in water can be achieved within 1s time, and the response time of the prototype when the dissolved CO2 concentration changed abruptly in actual measurement was 15 s. To evaluate the performance of the prototype, comparison measurements were carried out with a commercial mass spectrometer. The dissolved CO2 in both seawater and tap-water was measured, and the experimental results showed good consistent trends with R2 of 0.973 and 0.931. The experimental results proved the feasibility of dissolved CO2 rapid measurement. In the near future, more system evaluation experiments will be carried out and the system will be further

  13. Timing of Secondary Hydrothermal Alteration of the Luobusa Chromitites Constrained by Ar/Ar Dating of Chrome Chlorites

    Directory of Open Access Journals (Sweden)

    Wei Guo

    2018-05-01

    Full Text Available Chrome chlorites are usually found as secondary phases formed by hydrothermal alteration of chromite deposits and associated mafic/ultramafic rocks. Here, we report the 40Ar/39Ar age of chrome chlorites separated from the Luobusa massive chromitites which have undergone secondary alteration by CO2-rich hydrothermal fluids. The dating results reveal that the intermediate heating steps (from 4 to 10 of sample L7 generate an age plateau of 29.88 ± 0.42 Ma (MSWD = 0.12, plateau 39Ar = 74.6%, and the plateau data points define a concordant inverse isochron age of 30.15 ± 1.05 Ma (MSWD = 0.08, initial 40Ar/36Ar = 295.8 ± 9.7. The Ar release pattern shows no evidence of later degassing or inherited radiogenic component indicated by an atmospheric intercept, thus representing the age of the hydrothermal activity. Based on the agreement of this hydrothermal age with the ~30 Ma adakitic plutons exposed in nearby regions (the Zedong area, tens of kilometers west Luobusa and the extensive late Oligocene plutonism distributed along the southeastern Gangdese magmatic belt, it is suggested that the hydrothermal fluids are likely related to the ~30 Ma magmatism. The hydrothermal fluid circulation could be launched either by remote plutons (such as the Sangri granodiorite, the nearest ~30 Ma pluton west Luobusa or by a similar coeval pluton in the local Luobusa area (inferred, not found or reported so far. Our results provide important clues for when the listwanites in Luobusa were formed.

  14. Determination of free CO2 in emergent groundwaters using a commercial beverage carbonation meter

    Science.gov (United States)

    Vesper, Dorothy J.; Edenborn, Harry M.

    2012-05-01

    SummaryDissolved CO2 in groundwater is frequently supersaturated relative to its equilibrium with atmospheric partial pressure and will degas when it is conveyed to the surface. Estimates of dissolved CO2 concentrations can vary widely between different hydrochemical facies because they have different sources of error (e.g., rapid degassing, low alkalinity, non-carbonate alkalinity). We sampled 60 natural spring and mine waters using a beverage industry carbonation meter, which measures dissolved CO2 based on temperature and pressure changes as the sample volume is expanded. Using a modified field protocol, the meter was found to be highly accurate in the range 0.2-35 mM CO2. The meter provided rapid, accurate and precise measurements of dissolved CO2 in natural waters for a range of hydrochemical facies. Dissolved CO2 concentrations measured in the field with the carbonation meter were similar to CO2 determined using the pH-alkalinity approach, but provided immediate results and avoided errors from alkalinity and pH determination. The portability and ease of use of the carbonation meter in the field made it well-suited to sampling in difficult terrain. The carbonation meter has proven useful in the study of aquatic systems where CO2 degassing drives geochemical changes that result in surficial mineral precipitation and deposition, such as tufa, travertine and mine drainage deposits.

  15. Magma-derived CO2 emissions in the Tengchong volcanic field, SE Tibet: Implications for deep carbon cycle at intra-continent subduction zone

    Science.gov (United States)

    Zhang, Maoliang; Guo, Zhengfu; Sano, Yuji; Zhang, Lihong; Sun, Yutao; Cheng, Zhihui; Yang, Tsanyao Frank

    2016-09-01

    Active volcanoes at oceanic subduction zone have long been regard as important pathways for deep carbon degassed from Earth's interior, whereas those at continental subduction zone remain poorly constrained. Large-scale active volcanoes, together with significant modern hydrothermal activities, are widely distributed in the Tengchong volcanic field (TVF) on convergent boundary between the Indian and Eurasian plates. They provide an important opportunity for studying deep carbon cycle at the ongoing intra-continent subduction zone. Soil microseepage survey based on accumulation chamber method reveals an average soil CO2 flux of ca. 280 g m-2 d-1 in wet season for the Rehai geothermal park (RGP). Combined with average soil CO2 flux in dry season (ca. 875 g m-2 d-1), total soil CO2 output of the RGP and adjacent region (ca. 3 km2) would be about 6.30 × 105 t a-1. Additionally, we conclude that total flux of outgassing CO2 from the TVF would range in (4.48-7.05) × 106 t a-1, if CO2 fluxes from hot springs and soil in literature are taken into account. Both hot spring and soil gases from the TVF exhibit enrichment in CO2 (>85%) and remarkable contribution from mantle components, as indicated by their elevated 3He/4He ratios (1.85-5.30 RA) and δ13C-CO2 values (-9.00‰ to -2.07‰). He-C isotope coupling model suggests involvement of recycled organic metasediments and limestones from subducted Indian continental lithosphere in formation of the enriched mantle wedge (EMW), which has been recognized as source region of the TVF parental magmas. Contamination by crustal limestone is the first-order control on variations in He-CO2 systematics of volatiles released by the EMW-derived melts. Depleted mantle and recycled crustal materials from subducted Indian continental lithosphere contribute about 45-85% of the total carbon inventory, while the rest carbon (about 15-55%) is accounted by limestones in continental crust. As indicated by origin and evolution of the TVF

  16. Geophysical and geochemical methods applied to investigate fissure-related hydrothermal systems on the summit area of Mt. Etna volcano (Italy)

    Science.gov (United States)

    Maucourant, Samuel; Giammanco, Salvatore; Greco, Filippo; Dorizon, Sophie; Del Negro, Ciro

    2014-06-01

    A multidisciplinary approach integrating self-potential, soil temperature, heat flux, CO2 efflux and gravity gradiometry signals was used to investigate a relatively small fissure-related hydrothermal system near the summit of Mt. Etna volcano (Italy). Measurements were performed through two different surveys carried out at the beginning and at the end of July 2009, right after the end of the long-lived 2008-2009 flank eruption and in coincidence with an increase in diffuse flank degassing related to a reactivation of the volcano, leading to the opening of a new summit vent (NSEC). The main goal was to use a multidisciplinary approach to the detection of hidden fractures in an area of evident near-surface hydrothermal activity. Despite the different methodologies used and the different geometry of the sampling grid between the surveys, all parameters concurred in confirming that the study area is crossed by faults related with the main fracture systems of the south flank of the volcano, where a continuous hydrothermal circulation is established. Results also highlighted that hydrothermal activity in this area changed both in space and in time. These changes were a clear response to variations in the magmatic system, notably to migration of magma at various depth within the main feeder system of the volcano. The results suggest that this specific area, initially chosen as the optimal test-site for the proposed approach, can be useful in order to get information on the potential reactivation of the summit craters of Mt. Etna.

  17. Forecasting global atmospheric CO2

    International Nuclear Information System (INIS)

    Agusti-Panareda, A.; Massart, S.; Boussetta, S.; Balsamo, G.; Beljaars, A.; Engelen, R.; Jones, L.; Peuch, V.H.; Chevallier, F.; Ciais, P.; Paris, J.D.; Sherlock, V.

    2014-01-01

    A new global atmospheric carbon dioxide (CO 2 ) real-time forecast is now available as part of the preoperational Monitoring of Atmospheric Composition and Climate - Interim Implementation (MACC-II) service using the infrastructure of the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecasting System (IFS). One of the strengths of the CO 2 forecasting system is that the land surface, including vegetation CO 2 fluxes, is modelled online within the IFS. Other CO 2 fluxes are prescribed from inventories and from off-line statistical and physical models. The CO 2 forecast also benefits from the transport modelling from a state-of-the-art numerical weather prediction (NWP) system initialized daily with a wealth of meteorological observations. This paper describes the capability of the forecast in modelling the variability of CO 2 on different temporal and spatial scales compared to observations. The modulation of the amplitude of the CO 2 diurnal cycle by near-surface winds and boundary layer height is generally well represented in the forecast. The CO 2 forecast also has high skill in simulating day-to-day synoptic variability. In the atmospheric boundary layer, this skill is significantly enhanced by modelling the day-to-day variability of the CO 2 fluxes from vegetation compared to using equivalent monthly mean fluxes with a diurnal cycle. However, biases in the modelled CO 2 fluxes also lead to accumulating errors in the CO 2 forecast. These biases vary with season with an underestimation of the amplitude of the seasonal cycle both for the CO 2 fluxes compared to total optimized fluxes and the atmospheric CO 2 compared to observations. The largest biases in the atmospheric CO 2 forecast are found in spring, corresponding to the onset of the growing season in the Northern Hemisphere. In the future, the forecast will be re-initialized regularly with atmospheric CO 2 analyses based on the assimilation of CO 2 products retrieved from satellite

  18. Monitoring quiescent volcanoes by diffuse He degassing: case study Teide volcano

    Science.gov (United States)

    Pérez, Nemesio M.; Melián, Gladys; Asensio-Ramos, María; Padrón, Eleazar; Hernández, Pedro A.; Barrancos, José; Padilla, Germán; Rodríguez, Fátima; Calvo, David; Alonso, Mar

    2016-04-01

    Tenerife (2,034 km2), the largest of the Canary Islands, is the only island that has developed a central volcanic complex (Teide-Pico Viejo stratovolcanoes), characterized by the eruption of differentiated magmas. This central volcanic complex has been built in the intersection of the three major volcanic rift-zones of Tenerife, where most of the historical volcanic activity has taken place. The existence of a volcanic-hydrothermal system beneath Teide volcano is suggested by the occurrence of a weak fumarolic system, steamy ground and high rates of diffuse CO2 degassing all around the summit cone of Teide (Pérez et al., 2013). Diffuse emission studies of non-reactive and/or highly mobile gases such as helium have recently provided promising results to detect changes in the magmatic gas component at surface related to volcanic unrest episodes (Padrón et al., 2013). The geochemical properties of He minimize the interaction of this noble gas on its movement toward the earth's surface, and its isotopic composition is not affected by subsequent chemical reactions. It is highly mobile, chemically inert, physically stable, non-biogenic, sparingly soluble in water under ambient conditions, almost non-adsorbable, and highly diffusive with a diffusion coefficient ˜10 times that of CO2. As part of the geochemical monitoring program for the volcanic surveillance of Teide volcano, yearly surveys of diffuse He emission through the surface of the summit cone of Teide volcano have been performed since 2006. Soil He emission rate was measured yearly at ˜130 sampling sites selected in the surface environment of the summit cone of Teide volcano (Tenerife, Canary Islands), covering an area of ˜0.5 km2, assuming that He emission is governed by convection and diffusion. The distribution of the sampling sites was carefully chosen to homogeneously cover the target area, allowing the computation of the total He emission by sequential Gaussian simulation (sGs). Nine surveys have been

  19. Characterization of hydrotalcite materials for CO2 selective membranes

    Energy Technology Data Exchange (ETDEWEB)

    Feuillade, V.C.; Haije, W.G. [ECN Hydrogen and Clean Fossil Fuels, Petten (Netherlands)

    2006-07-15

    The present concern about climate change has urged researchers and engineers all over the world to go and look for ways of reducing greenhouse gas emissions. Largescale CO2 emissions occur at power plants burning fossil fuels or e.g. the production of hydrogen from carbonaceous feed. In these cases pre- or post-combustion CO2 capture techniques followed by CO2 storage seems a promising route for reducing emissions. Prerequisite in these processes is the effective separation of CO2 from mixed gaseous process streams. The purpose of this work is to develop CO2 membranes to allow for the combination of natural gas reforming with separation of H2 and CO2 in separation enhanced reactors, i.e. membrane reactors, for carbon-free hydrogen production or electricity generation. This paper describes the materials' properties of hydrotalcites, a promising class of compounds for CO2 membranes. They have already proven their applicability as CO2 sorbent in sorption enhanced reaction processes. It is of fundamental importance to know the structural stability of this compound in the operational window of a chosen membrane reactor prior to any membrane fabrication. To this end, in-situ XRPD and DRIFTS as well as TGA-MS and SEM-EDX measurements have been performed on commercial (Pural) and hydrothermally synthesized homemade samples.

  20. Magmas near the critical degassing pressure drive volcanic unrest towards a critical state

    Science.gov (United States)

    Chiodini, Giovanni; Paonita, Antonio; Aiuppa, Alessandro; Costa, Antonio; Caliro, Stefano; De Martino, Prospero; Acocella, Valerio; Vandemeulebrouck, Jean

    2016-01-01

    During the reawaking of a volcano, magmas migrating through the shallow crust have to pass through hydrothermal fluids and rocks. The resulting magma–hydrothermal interactions are still poorly understood, which impairs the ability to interpret volcano monitoring signals and perform hazard assessments. Here we use the results of physical and volatile saturation models to demonstrate that magmatic volatiles released by decompressing magmas at a critical degassing pressure (CDP) can drive volcanic unrest towards a critical state. We show that, at the CDP, the abrupt and voluminous release of H2O-rich magmatic gases can heat hydrothermal fluids and rocks, triggering an accelerating deformation that can ultimately culminate in rock failure and eruption. We propose that magma could be approaching the CDP at Campi Flegrei, a volcano in the metropolitan area of Naples, one of the most densely inhabited areas in the world, and where accelerating deformation and heating are currently being observed. PMID:27996976

  1. CO2 as a refrigerant

    CERN Document Server

    2014-01-01

    A first edition, the IIR guide “CO2 as a Refrigerant” highlights the application of carbon dioxide in supermarkets, industrial freezers, refrigerated transport, and cold stores as well as ice rinks, chillers, air conditioning systems, data centers and heat pumps. This guide is for design and development engineers needing instruction and inspiration as well as non-technical experts seeking background information on a specific topic. Written by Dr A.B. Pearson, a well-known expert in the field who has considerable experience in the use of CO2 as a refrigerant. Main topics: Thermophysical properties of CO2 – Exposure to CO2, safety precautions – CO2 Plant Design – CO2 applications – Future prospects – Standards and regulations – Bibliography.

  2. The radiogenic and stable Sr isotope geochemistry of basalt weathering in Iceland: Role of hydrothermal calcite and implications for long-term climate regulation

    Science.gov (United States)

    Andrews, M. Grace; Jacobson, Andrew D.

    2017-10-01

    Several studies have examined the geochemistry of Icelandic rivers to quantify the relationship between basalt weathering and long-term climate regulation. Recent research has suggested that the chemical weathering of hydrothermal and metamorphic calcite contributes significant quantities of HCO3- to the Icelandic riverine flux (Jacobson et al., 2015). Because the HCO3- derives from volcanic CO2 that was sequestered in mineral form prior to atmospheric injection, the strength of the basalt weathering feedback occurring in Iceland may be lower than previously realized. To test these hypotheses, we analyzed the radiogenic and stable Sr isotope composition (87Sr/86Sr and δ88/86Sr) of the same suite of water, rock, and mineral samples as examined in Jacobson et al. (2015), and we developed a simple model of the long-term C cycle that considers the transformation of volcanic CO2 to HCO3- during subsurface silicate weathering, which is a precursor to hydrothermal calcite formation. Interpretations based on 87Sr/86Sr and Ca/Sr ratios suggest that conservative, three-component mixing between basalt, calcite, and atmospheric deposition adequately explains river geochemistry. On average, the δ88/86Sr values of glacial and non-glacial rivers (0.414‰ and 0.388‰, respectively) are generally higher than those for basalt (0.276‰); however, calcite δ88/86Sr values (0.347‰) are also higher than those for basalt and span the range of riverine values. Thus, riverine δ88/86Sr values are also consistent three-component mixing between basalt, calcite, and atmospheric deposition. Isotopic fractionation is not required to explain riverine trends. Finally, model equations for the long-term C cycle demonstrate that subsurface silicate weathering reduces the magnitude of the volcanic CO2 degassing flux, which in turn causes the atmosphere to stabilize at lower pCO2 values compared to the case where no subsurface silicate weathering occurs. However, the proportion of the net

  3. The 2012 Copahue eruption: magnitude of gas fluxes and time scale of degassing

    Science.gov (United States)

    Varekamp, J. C.; Camfield, L.

    2015-12-01

    Copahue volcano (Argentina, 37.5 S, 71.5 W) erupted in 2000 and 2012 with initial phreato-magmatic blasts, violent Strombolian eruptions of several hours duration, followed by open conduit activity for days to months. The 2012 basal deposits 10 km S of Copahue are mm-sized ashes with hydrothermally altered debris, followed by up to 10cm pancake pumices, while denser cinders fell near the crater in the waning stages. The strombolian plume was ~ 6 km high and satellite images show its trajectory up to 200 km S. The pumices have finely porous rims (0.3mm vesicles) that were probably quenched by hydrothermal fluids and coarse interiors (several mm vesicles) that inflated during eruption. All the products have identical chemical composition and mineralogy, and only vary in degree of vesiculation. The 2012 products are the most mafic of the whole volcanic history of Copahue, with MgO ~ 4.5 %. The quench rim pumice glass contains 1160 ppm Cl while glass inclusions have up to 1800 ppm Cl. Water concentrations are 0.5-2.0 % (by difference with EMPA) and plagioclase hygrometry. Pre-eruptive conditions were 1080 oC and 1-2.5 kb pressure. The magmato-hydrothermal system is leaking fluids into the overlying crater lake and into a river. The hot springs have pH <1 and these fluids are up to 60% magmatic in origin. Annual river flux measurements and non-steady state modeling between 1997 and 2013 constrain the mean hydrothermal Cl flux at 1170 tonnes/month. The 2012 erupted magma mass is about 1012 gr, and from the measured total Cl loss between 2000 and 2012 and mean degassed Cl in the magma the volume of degassing magma is estimated at 1014-1015 grams. Much more magma was degassing than was erupted. Analyses of 226Ra-210Pb constrained the maximum degassing time at 8-10 years prior to the 2012 eruption. Almost all rock samples have 210Pb deficits, and so most gas escaped from the magma into the hydrothermal system. Nonetheless, the top of the magma reservoir accumulated bubbles

  4. The sequestration of CO2

    International Nuclear Information System (INIS)

    Le Thiez, P.

    2004-01-01

    The reduction of greenhouse gas emissions, especially CO 2 , represents a major technological and societal challenge in the fight against climate change. Among the measures likely to reduce anthropic CO 2 emissions, capture and geological storage holds out promise for the future. (author)

  5. CO2 Sequestration short course

    Energy Technology Data Exchange (ETDEWEB)

    DePaolo, Donald J. [Lawrence Berkeley National Laboratory; Cole, David R [The Ohio State University; Navrotsky, Alexandra [University of California-Davis; Bourg, Ian C [Lawrence Berkeley National Laboratory

    2014-12-08

    Given the public’s interest and concern over the impact of atmospheric greenhouse gases (GHGs) on global warming and related climate change patterns, the course is a timely discussion of the underlying geochemical and mineralogical processes associated with gas-water-mineral-interactions encountered during geological sequestration of CO2. The geochemical and mineralogical processes encountered in the subsurface during storage of CO2 will play an important role in facilitating the isolation of anthropogenic CO2 in the subsurface for thousands of years, thus moderating rapid increases in concentrations of atmospheric CO2 and mitigating global warming. Successful implementation of a variety of geological sequestration scenarios will be dependent on our ability to accurately predict, monitor and verify the behavior of CO2 in the subsurface. The course was proposed to and accepted by the Mineralogical Society of America (MSA) and The Geochemical Society (GS).

  6. Enzymes in CO2 Capture

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup; Gladis, Arne; Thomsen, Kaj

    The enzyme Carbonic Anhydrase (CA) can accelerate the absorption rate of CO2 into aqueous solutions by several-fold. It exist in almost all living organisms and catalyses different important processes like CO2 transport, respiration and the acid-base balances. A new technology in the field...... of carbon capture is the application of enzymes for acceleration of typically slow ternary amines or inorganic carbonates. There is a hidden potential to revive currently infeasible amines which have an interesting low energy consumption for regeneration but too slow kinetics for viable CO2 capture. The aim...... of this work is to discuss the measurements of kinetic properties for CA promoted CO2 capture solvent systems. The development of a rate-based model for enzymes will be discussed showing the principles of implementation and the results on using a well-known ternary amine for CO2 capture. Conclusions...

  7. Mind the gap: non-biological processes contributing to soil CO2 efflux.

    Science.gov (United States)

    Rey, Ana

    2015-05-01

    Widespread recognition of the importance of soil CO2 efflux as a major source of CO2 to the atmosphere has led to active research. A large soil respiration database and recent reviews have compiled data, methods, and current challenges. This study highlights some deficiencies for a proper understanding of soil CO2 efflux focusing on processes of soil CO2 production and transport that have not received enough attention in the current soil respiration literature. It has mostly been assumed that soil CO2 efflux is the result of biological processes (i.e. soil respiration), but recent studies demonstrate that pedochemical and geological processes, such as geothermal and volcanic CO2 degassing, are potentially important in some areas. Besides the microbial decomposition of litter, solar radiation is responsible for photodegradation or photochemical degradation of litter. Diffusion is considered to be the main mechanism of CO2 transport in the soil, but changes in atmospheric pressure and thermal convection may also be important mechanisms driving soil CO2 efflux greater than diffusion under certain conditions. Lateral fluxes of carbon as dissolved organic and inorganic carbon occur and may cause an underestimation of soil CO2 efflux. Traditionally soil CO2 efflux has been measured with accumulation chambers assuming that the main transport mechanism is diffusion. New techniques are available such as improved automated chambers, CO2 concentration profiles and isotopic techniques that may help to elucidate the sources of carbon from soils. We need to develop specific and standardized methods for different CO2 sources to quantify this flux on a global scale. Biogeochemical models should include biological and non-biological CO2 production processes before we can predict the response of soil CO2 efflux to climate change. Improving our understanding of the processes involved in soil CO2 efflux should be a research priority given the importance of this flux in the global

  8. Liquid metal degassing in electromagnetic mixing

    Energy Technology Data Exchange (ETDEWEB)

    Pakhomov, A I; EHL' -FAVAKHRI, KAMAL' -ABD-RABU MOKHAMED [LENINGRADSKIJ POLITEKHNICHESKIJ INST. (USSR)

    1977-01-01

    Experimental results for laboratory and industrial conditions are presented showing the favourable effect of electromagnetic mixing on hot metal degassing process. It has been found that the intensity and duration of the mixing process increase with the degree of iron and steel degassing. Initiation of cavitation phenomena during hot metal electromagnetic mixing is intensified because of the presence of alien inclusions in the metal reducing the tensile strength of the liquid metal. This is the most substantial factor contributing to the gas content in the process of electromagnetic mixing.

  9. CO2 pellet blasting studies

    International Nuclear Information System (INIS)

    Archibald, K.E.

    1997-01-01

    Initial tests with CO 2 pellet blasting as a decontamination technique were completed in 1993 at the Idaho Chemical Processing Plant (ICPP) at the Idaho National Engineering Laboratory (INEL). During 1996, a number of additional CO 2 pellet blasting studies with Alpheus Cleaning Technologies, Oak Ridge National Laboratory, and Pennsylvania State University were conducted. After the testing with Alpheus was complete, an SDI-5 shaved CO 2 blasting unit was purchased by the ICPP to test and determine its capabilities before using in ICPP decontamination efforts. Results of the 1996 testing will be presented in this report

  10. CO2: a worldwide myth

    International Nuclear Information System (INIS)

    Gerondeau, Ch.

    2009-01-01

    In this book, the author demonstrates the paradox that reducing CO 2 emissions leads to no CO 2 abatement at all. This assertion is based on an obvious statement. Everybody knows that oil resources are going to be exhausted in few decades. The oil that industrialized countries will not use will be consumed by emerging countries and the CO 2 emissions will remain the same. Who would believe that the oil, gas or coal still available will remain unused? The Kyoto protocol, the national policies, the European agreements of emissions abatement, the carbon taxes, the emissions abatement requests sent to the rest of the world, all these actions cost a lot and are useless. CO 2 concentration in the atmosphere will inescapably double during the 21. century but, according to the author, without any catastrophic consequence for the Earth. (J.S.)

  11. Connecting CO2. Feasibility study CO2 network Southwest Netherlands; Connecting CO2. Haalbaarheidsstudie CO2-netwerk Zuidwest-Nederland

    Energy Technology Data Exchange (ETDEWEB)

    Rutten, M.

    2009-06-10

    An overview is given of supply and demand of CO2 in the region Southwest Netherlands and the regions Antwerp and Gent in Belgium. Also attention is paid to possible connections between these regions [Dutch] Een inventarisatie wordt gegeven van vraag en aanbod van CO2 in de regio Zuidwest- Nederland en de regios Antwerpen en Gent in Belgie. Ook worden mogelijke koppelingen tussen de regios besproken.

  12. Foraminiferal calcification and CO2

    Science.gov (United States)

    Nooijer, L. D.; Toyofuku, T.; Reichart, G. J.

    2017-12-01

    Ongoing burning of fossil fuels increases atmospheric CO2, elevates marine dissolved CO2 and decreases pH and the saturation state with respect to calcium carbonate. Intuitively this should decrease the ability of CaCO3-producing organisms to build their skeletons and shells. Whereas on geological time scales weathering and carbonate deposition removes carbon from the geo-biosphere, on time scales up to thousands of years, carbonate precipitation increases pCO2 because of the associated shift in seawater carbon speciation. Hence reduced calcification provides a potentially important negative feedback on increased pCO2 levels. Here we show that foraminifera form their calcium carbonate by active proton pumping. This elevates the internal pH and acidifies the direct foraminiferal surrounding. This also creates a strong pCO2 gradient and facilitates the uptake of DIC in the form of carbon dioxide. This finding uncouples saturation state from calcification and predicts that the added carbon due to ocean acidification will promote calcification by these organisms. This unknown effect could add substantially to atmospheric pCO2 levels, and might need to be accounted for in future mitigation strategies.

  13. Seawater bicarbonate removal during hydrothermal circulation

    Science.gov (United States)

    Proskurowski, G. K.; Seewald, J.; Sylva, S. P.; Reeves, E.; Lilley, M. D.

    2013-12-01

    High temperature fluids sampled at hydrothermal vents represent a complex alteration product of water-rock reactions on a multi-component mixture of source fluids. Sources to high-temperature hydrothermal samples include the 'original' seawater present in the recharge limb of circulation, magmatically influenced fluids added at depth as well as any seawater entrained during sampling. High-temperature hydrothermal fluids are typically enriched in magmatic volatiles, with CO2 the dominant species, characterized by concentrations of 10's-100's of mmol/kg (1, 2). Typically, the high concentration of CO2 relative to background seawater bicarbonate concentrations (~2.3 mmol/kg) obscures a full analysis of the fate of seawater bicarbonate during high-temperature hydrothermal circulation. Here we present data from a suite of samples collected over the past 15 years from high-temperature hydrothermal vents at 9N, Endeavour, Lau Basin, and the MAR that have endmember CO2 concentrations less than 10 mmol/kg. Using stable and radiocarbon isotope measurements these samples provide a unique opportunity to examine the balance between 'original' seawater bicarbonate and CO2 added from magmatic sources. Multiple lines of evidence from multiple hydrothermal settings consistently points to the removal of ~80% of the 'original' 2.3 mmol/kg seawater bicarbonate. Assuming that this removal occurs in the low-temperature, 'recharge' limb of hydrothermal circulation, this removal process is widely occurring and has important contributions to the global carbon cycle over geologic time. 1. Lilley MD, Butterfield DA, Lupton JE, & Olson EJ (2003) Magmatic events can produce rapid changes in hydrothermal vent chemistry. Nature 422(6934):878-881. 2. Seewald J, Cruse A, & Saccocia P (2003) Aqueous volatiles in hydrothermal fluids from the Main Endeavour Field, northern Juan de Fuca Ridge: temporal variability following earthquake activity. Earth and Planetary Science Letters 216(4):575-590.

  14. Riverine CO2 supersaturation and outgassing in a subtropical monsoonal mountainous area (Three Gorges Reservoir Region) of China

    Science.gov (United States)

    Li, Siyue; Ni, Maofei; Mao, Rong; Bush, Richard T.

    2018-03-01

    Rivers are an important source of CO2 to the atmosphere, however, mountainous rivers and streams with high emission rates are not well studied particularly in China. We report the first detailed investigation on monsoonal mountainous rivers in the Three Gorges Reservoir (TGR) region, with a focus on the riverine CO2 partial pressure (pCO2), CO2 degassing and their potential controls. The pCO2 levels ranged from 50 to 6019 μatm with averages of 1573 (SD. ±1060) in dry Autumn and 1276 (SD. ±1166) μatm in wet Summer seasons. 94% of samples were supersaturated with CO2 with respect to the atmospheric equilibrium (410 μatm). Monsoonal precipitation controlled pCO2 seasonality, with both the maximal and minimal levels occurring in the wet season, and showing the overall effects of dilution. Riverine pCO2 could be predicted better in the dry season using pH, DO% and DTP, whereas pH and DOC were better predictors in the wet season. We conclude that in-situ respiration of allochthonous organic carbon, rather than photosynthesis, resulted in negative relationships between pCO2 and DO and pH, and thus CO2 supersaturation. Photosynthetic primary production was effectively limited by rapid flow velocity and short residence time. The estimated water-to-air CO2 emission rate in the TGR rivers was 350 ± 319 in the Autumn and lower, yet more variable at 326 ± 439 mmol/m2/d in Summer. Our calculated CO2 areal fluxes were in the upper-level magnitude of published data, demonstrating the importance of mountainous rivers and streams as a global greenhouse gas source, and urgency for more detailed studies on CO2 degassing, to address a global data gap for these environments.

  15. CO2 Capture and Reuse

    International Nuclear Information System (INIS)

    Thambimuthu, K.; Gupta, M.; Davison, J.

    2003-01-01

    CO2 capture and storage including its utilization or reuse presents an opportunity to achieve deep reductions in greenhouse gas emissions from fossil energy use. The development and deployment of this option could significantly assist in meeting a future goal of achieving stabilization of the presently rising atmospheric concentration of greenhouse gases. CO2 capture from process streams is an established concept that has achieved industrial practice. Examples of current applications include the use of primarily, solvent based capture technologies for the recovery of pure CO2 streams for chemical synthesis, for utilization as a food additive, for use as a miscible agent in enhanced oil recovery operations and removal of CO2 as an undesired contaminant from gaseous process streams for the production of fuel gases such as hydrogen and methane. In these applications, the technologies deployed for CO2 capture have focused on gas separation from high purity, high pressure streams and in reducing (or oxygen deficient) environments, where the energy penalties and cost for capture are moderately low. However, application of the same capture technologies for large scale abatement of greenhouse gas emissions from fossil fuel use poses significant challenges in achieving (at comparably low energy penalty and cost) gas separation in large volume, dilute concentration and/or low pressure flue gas streams. This paper will focus on a review of existing commercial methods of CO2 capture and the technology stretch, process integration and energy system pathways needed for their large scale deployment in fossil fueled processes. The assessment of potential capture technologies for the latter purpose will also be based on published literature data that are both 'transparent' and 'systematic' in their evaluation of the overall cost and energy penalties of CO2 capture. In view of the of the fact that many of the existing commercial processes for CO2 capture have seen applications in

  16. Reconciling Gases With Glasses: Magma Degassing, Overturn and Mixing at Kilauea Volcano, Hawai`i

    Science.gov (United States)

    Edmonds, M.; Gerlach, T. M.

    2006-12-01

    Our understanding of the volatile budget at Kilauea Volcano is based on measurements of the abundance of volatile elements in volcanic glasses and gases. Observations of volcanic gases gave rise to a fundamental model describing volatile fractionation between the summit and rift zone during the current eruption [Gerlach and Graeber, 1985]. Other workers' analysis of glasses from the Puna Ridge, Kilauea Iki and Pu`u `O`o indicate that magma degassing, drain-back, mixing and assimilation are important processes at Kilauea Volcano. Volcanic gases have not illustrated these kinds of processes clearly in the past, owing to infrequent and poorly resolved data. New, detailed studies of volcanic gas emissions have refined our understanding of volatile degassing and magma budgets at Kilauea Volcano. Open Path Fourier Transform Infra-Red spectroscopy measurements carried out during 2004-2005 allow retrieval of the relative abundances of the major volatile species H2O, CO2 and SO2, which together make up >99 vol% of the magmatic vapor phase. The proportions of these gases vary over time and space and can be used to infer magma transport, ascent, degassing, overturn and mixing and gas segregation processes within the plumbing system of Kilauea Volcano. Gases from Pu`u `O`o in 2004-2005 display a range in composition. A trend relates molar C/S to the total H2O content of the gases over time and space; total H2O ranges from 60-98 mol %, while molar C/S ranges from 50. The range in volcanic gas composition over time and space is caused by magma degassing, overturn and mixing of partially degassed magma with fresh primary magma beneath Pu`u `O`o. Measurements of the mean rate of magma degassing (from SO2 emissions) and mean lava effusion rate (from geophysical measurements of lava tube flux) suggest that a larger volume (DRE) of magma is degassing than is being erupted, on average. This analysis suggests that magma storage in the Rift Zone might be important during eruptions as

  17. Theoretical analysis and experimental study of spray degassing method

    International Nuclear Information System (INIS)

    Wu Ruizhi; Shu Da; Sun Baode; Wang Jun; Li Fei; Chen Haiyan; Lu YanLing

    2005-01-01

    A new hydrogen-removal method of aluminum melt, spray degassing, is presented. The thermodynamic and kinetic analysis of the method are discussed. A comparison between the thermodynamics and kinetics of the spray degassing method and rotary impellor degassing method is made. The thermodynamic analysis shows that the relationship between the final hydrogen content of the aluminum melt and the ratio of purge gas flow rate to melt flow rate is linear. The result of thermodynamic calculation shows that, in spray degassing, when the ratio of G/q is larger than 2.2 x 10 -6 , the final hydrogen content will be less than 0.1 ml/100 g Al. From the kinetic analysis, the degassing effect is affected by both the size of melt droplets and the time that melt droplets move from sprayer to the bottom of the treatment tank. In numerical calculation, the hydrogen in aluminum melt can be degassed to 0.05 ml/100 g Al from 0.2 ml/100 g Al in 0.02 s with the spray degassing method. Finally, the water-model experiments are presented with the spray degassing method and rotary impellor degassing method. Melt experiments are also presented. Both the water-model experiments and the melt experiments show that the degassing effect of the spray degassing method is better than that of the rotary impeller method

  18. The CO2nnect activities

    Science.gov (United States)

    Eugenia, Marcu

    2014-05-01

    Climate change is one of the biggest challenges we face today. A first step is the understanding the problem, more exactly what is the challenge and the differences people can make. Pupils need a wide competencies to meet the challenges of sustainable development - including climate change. The CO2nnect activities are designed to support learning which can provide pupils the abilities, skills, attitudes and awareness as well as knowledge and understanding of the issues. The project "Together for a clean and healthy world" is part of "The Global Educational Campaign CO2nnect- CO2 on the way to school" and it was held in our school in the period between February and October 2009. It contained a variety of curricular and extra-curricular activities, adapted to students aged from 11 to 15. These activities aimed to develop in students the necessary skills to understanding man's active role in improving the quality of the environment, putting an end to its degrading process and to reducing the effects of climate changes caused by the human intervention in nature, including transport- a source of CO2 pollution. The activity which I propose can be easily adapted to a wide range of age groups and linked to the curricula of many subjects: - Investigate CO2 emissions from travel to school -Share the findings using an international database -Compare and discuss CO2 emissions -Submit questions to a climate- and transport expert -Partner with other schools -Meet with people in your community to discuss emissions from transport Intended learning outcomes for pupils who participate in the CO2nnect campaign are: Understanding of the interconnected mobility- and climate change issue climate change, its causes and consequences greenhouse-gas emissions from transport and mobility the interlinking of social, environmental, cultural and economic aspects of the local transport system how individual choices and participation can contribute to creating a more sustainable development

  19. CO2 storage in Sweden

    International Nuclear Information System (INIS)

    Ekstroem, Clas; Andersson, Annika; Kling, Aasa; Bernstone, Christian; Carlsson, Anders; Liljemark, Stefan; Wall, Caroline; Erstedt, Thomas; Lindroth, Maria; Tengborg, Per; Edstroem, Mikael

    2004-07-01

    This study considers options, that could be feasible for Sweden, to transport and geologically store CO 2 , providing that technology for electricity production with CO 2 capture will be available in the future and also acceptable from cost- and reliability point of view. As a starting point, it is assumed that a new 600-1000 MW power plant, fired with coal or natural gas, will be constructed with CO 2 capture and localised to the Stockholm, Malmoe or Goeteborg areas. Of vital importance for storage of carbon dioxide in a reservoir is the possibility to monitor its distribution, i.e. its migration within the reservoir. It has been shown in the SACS-project that the distribution of carbon dioxide within the reservoir can be monitored successfully, mainly by seismic methods. Suitable geologic conditions and a large storage potential seems to exist mainly in South West Scania, where additional knowledge on geology/hydrogeology has been obtained since the year 2000 in connection to geothermal energy projects, and in the Eastern part of Denmark, bordering on South West Scania. Storage of carbon dioxide from the Stockholm area should not be excluded, but more studies are needed to clarify the storage options within this area. The possibilities to use CO 2 for enhanced oil recovery, EOR, in i.a. the North Sea should be investigated, in order to receive incomes from the CO 2 and shared costs for infrastructure, and by this also make the CO 2 regarded as a trading commodity, and thereby achieving a more favourable position concerning acceptance, legal issues and regulations. The dimensions of CO 2 -pipelines should be similar to those for natural natural gas, although regarding some aspects they have different design and construction prerequisites. To obtain cost efficiency, the transport distances should be kept short, and possibilities for co-ordinated networks with short distribution pipelines connected to common main pipelines, should be searched for. Also, synergies

  20. Geochemistry of hydrothermal fluids from the PACMANUS, Northeast Pual and Vienna Woods hydrothermal fields, Manus Basin, Papua New Guinea

    Science.gov (United States)

    Reeves, Eoghan P.; Seewald, Jeffrey S.; Saccocia, Peter; Bach, Wolfgang; Craddock, Paul R.; Shanks, Wayne C.; Sylva, Sean P.; Walsh, Emily; Pichler, Thomas; Rosner, Martin

    2011-01-01

    Processes controlling the composition of seafloor hydrothermal fluids in silicic back-arc or near-arc crustal settings remain poorly constrained despite growing evidence for extensive magmatic-hydrothermal activity in such environments. We conducted a survey of vent fluid compositions from two contrasting sites in the Manus back-arc basin, Papua New Guinea, to examine the influence of variations in host rock composition and magmatic inputs (both a function of arc proximity) on hydrothermal fluid chemistry. Fluid samples were collected from felsic-hosted hydrothermal vent fields located on Pual Ridge (PACMANUS and Northeast (NE) Pual) near the active New Britain Arc and a basalt-hosted vent field (Vienna Woods) located farther from the arc on the Manus Spreading Center. Vienna Woods fluids were characterized by relatively uniform endmember temperatures (273-285 degrees C) and major element compositions, low dissolved CO2 concentrations (4.4 mmol/kg) and high measured pH (4.2-4.9 at 25 degrees C). Temperatures and compositions were highly variable at PACMANUS/NE Pual and a large, newly discovered vent area (Fenway) was observed to be vigorously venting boiling (358 degrees C) fluid. All PACMANUS fluids are characterized by negative delta DH2O values, in contrast to positive values at Vienna Woods, suggesting substantial magmatic water input to circulating fluids at Pual Ridge. Low measured pH (25 degrees C) values (~2.6-2.7), high endmember CO2 (up to 274 mmol/kg) and negative delta 34SH2S values (down to -2.7 permille) in some vent fluids are also consistent with degassing of acid-volatile species from evolved magma. Dissolved CO2 at PACMANUS is more enriched in 13C (-4.1 permille to -2.3 permille) than Vienna Woods (-5.2 permille to -5.7 permille), suggesting a contribution of slab-derived carbon. The mobile elements (e.g. Li, K, Rb, Cs and B) are also greatly enriched in PACMANUS fluids reflecting increased abundances in the crust there relative to the Manus

  1. Signals in water - the deep originated CO2 in the Peschiera-Capone acqueduct in relation to monitoring of seismic activity in central Italy

    Directory of Open Access Journals (Sweden)

    Claudio Martini

    2017-01-01

    Full Text Available Valuation of the analysis performed on groundwater of Central Lazio by ACEA ATO2 SpA from 2001 to 2016, according to the model proposed by Chiodini et al. in 2004 that identifies in the Tyrrhenian coast of central and southern Italy, two notable releasing areas of the CO2 produced by the sub-crustal magma activity, or two areas of natural degassing of the planet: the TRDS area (Tuscan Roman degassing structure and the CDS area (Campanian degassing structure. Reconstruction of the CO2 produced by degassing through the analysis of the components of inorganic carbon measured in groundwater of Central Lazio (Rome and Rieti districts between 2001 and 2016. Causal relationship of the activity of mantle degassing in the TRDS area with the disastrous earthquake occurred at L’Aquila in April 6, 2009. Current use of the dissolved inorganic carbon measurement in the Peschiera and Capore spring waters to monitor the activity of mantle degassing in the TRDS area, in order to have an early warning signal of possible seismic activity in the Central Apennines. Revision and data updating after the earthquake in August 24, 2016 at Amatrice.

  2. On a CO2 ration

    International Nuclear Information System (INIS)

    De Wit, P.

    2003-01-01

    In 2 years all the large energy companies in the European Union will have a CO2 ration, including a system to trade a shortage or surplus of emission rights. A cost effective system to reduce emission, provided that the government does not auction the emission rights [nl

  3. Reducing cement's CO2 footprint

    Science.gov (United States)

    van Oss, Hendrik G.

    2011-01-01

    The manufacturing process for Portland cement causes high levels of greenhouse gas emissions. However, environmental impacts can be reduced by using more energy-efficient kilns and replacing fossil energy with alternative fuels. Although carbon capture and new cements with less CO2 emission are still in the experimental phase, all these innovations can help develop a cleaner cement industry.

  4. Volatilization: a soil degassing coefficient for iodine

    International Nuclear Information System (INIS)

    Sheppard, M.I.; Thibault, D.H.; Smith, P.A.; Hawkins, J.L.

    1994-01-01

    Iodine, an element essential to some animals, is ubiquitous in the biosphere. Unlike other metallic elements, molecular I is volatile, and other inorganic species present in aerated soils, such as I - and IO 3 - , may also volatilize as hydrides, hydrogen iodide (HI), or hydrogen iodates (HIO 3 , HIO 4 ). Methyl iodide has been measured in soils, and it is likely evolved from soils and plants. The long-lived radioisotope 129 I is abundant in nuclear wastes, and its high solubility in groundwater makes it an important element in the performance assessment of underground disposal facilities. Overestimates of soil I residence half-times by traditional foodchain models may be due to underestimation of volatilization. Field and lysimeter experiments over a 3-year period, and direct trapping experiments in the laboratory are reported. The results, combined with values from the literature, indicate the soil I degassing coefficient for a wide range of soil types, vegetated and bare, wet and dry, is lognormally distributed with a geometric mean of 2.1 x 10 -2 year -1 , a range of 1.8 x 10 -4 to 3.1 year -1 and a geometric standard deviation of 3.0. The results of a biosphere model simulation including degassing reduces soil I concentrations fivefold and increases air concentrations 25-fold at steady state, compared to simulations without degassing. (author)

  5. Degassing of reduced carbon from planetary basalts.

    Science.gov (United States)

    Wetzel, Diane T; Rutherford, Malcolm J; Jacobsen, Steven D; Hauri, Erik H; Saal, Alberto E

    2013-05-14

    Degassing of planetary interiors through surface volcanism plays an important role in the evolution of planetary bodies and atmospheres. On Earth, carbon dioxide and water are the primary volatile species in magmas. However, little is known about the speciation and degassing of carbon in magmas formed on other planets (i.e., Moon, Mars, Mercury), where the mantle oxidation state [oxygen fugacity (fO2)] is different from that of the Earth. Using experiments on a lunar basalt composition, we confirm that carbon dissolves as carbonate at an fO2 higher than -0.55 relative to the iron wustite oxygen buffer (IW-0.55), whereas at a lower fO2, we discover that carbon is present mainly as iron pentacarbonyl and in smaller amounts as methane in the melt. The transition of carbon speciation in mantle-derived melts at fO2 less than IW-0.55 is associated with a decrease in carbon solubility by a factor of 2. Thus, the fO2 controls carbon speciation and solubility in mantle-derived melts even more than previous data indicate, and the degassing of reduced carbon from Fe-rich basalts on planetary bodies would produce methane-bearing, CO-rich early atmospheres with a strong greenhouse potential.

  6. Current Travertines Precipitation from CO2-rich Groundwaters as an alert of CO2 Leakages from a Natural CO2 Storage at Ganuelas-Mazarron Tertiary Basin (Murcia, Spain)

    International Nuclear Information System (INIS)

    Rodrigo-Naharro, J.; Delgado, A.; Herrero, M. J.; Granados, A.; Perez del Villar, L.

    2013-01-01

    hydrostatic pressure and the pCO 2 , resulting in a rapid degassing process; and ii) microbes and algae activity. This process leads to an increase in pH that favours the carbonates precipitation. Although there are not master physicochemical parameters controlling the precipitation of calcite or aragonite from their respective parent-waters, it is suggested that some parent-waters have the most suitable physicochemical features for the precipitation of one or another polymorph. Finally, the d13C values of DIC and carbonates could be used as good tracers for CO 2 leakages from an artificial CO 2 DGS. (Author) 101 refs.

  7. In situ growth of NiCo(2)S(4) nanosheets on graphene for high-performance supercapacitors.

    Science.gov (United States)

    Peng, Shengjie; Li, Linlin; Li, Chengchao; Tan, Huiteng; Cai, Ren; Yu, Hong; Mhaisalkar, Subodh; Srinivasan, Madhavi; Ramakrishna, Seeram; Yan, Qingyu

    2013-10-03

    We demonstrate a facile hydrothermal method for growth of ultrathin NiCo2S4 nanosheets on reduced graphene oxide (RGO), which exhibit remarkable electrochemical performance with higher capacitance and longer cycle life than the bare NiCo2S4 hollow spheres (HSs).

  8. Infrared remote sensing of Earth degassing - Ground study

    Directory of Open Access Journals (Sweden)

    P. Strobl

    2005-06-01

    Full Text Available Geodynamical processes e.g., volcanoes, often cause degassing at the Earth surface. The geogas emanates via mineral springs, water mofettes, or dry mofettes. It is assumed that the emerging gas influences the temperature of the spring or mofette water, respectively and the surface temperature of the soil at and around the dry gas vents. This causes a thermal anomaly in comparison to the close vicinity. Under specific conditions this effect should be extractable from remotely acquired infrared images allowing detection, mapping and monitoring of gas vents/springs within large areas and short times. This article describes preparatory investigations for which emanating Earth gas was simulated by leading compressed air into the ground and releasing it in some depth via a metal lance. The thermal effect at the surface was observed from a nearby thermovision camera in summer and winter under varying meteorological conditions. A procedure was developed to reliably identify gas release areas within the recorded thermal images of the scene. The investigations are aiming at studies to be performed later in the Western Bohemia (Czech Republic earthquake swarm region where especially CO2 of magmatic origin from European SubContinental Mantle (ESCM emanates.

  9. Continental smokers couple mantle degassing and distinctive microbiology within continents

    Science.gov (United States)

    Crossey, Laura J.; Karlstrom, Karl E.; Schmandt, Brandon; Crow, Ryan R.; Colman, Daniel R.; Cron, Brandi; Takacs-Vesbach, Cristina D.; Dahm, Clifford N.; Northup, Diana E.; Hilton, David R.; Ricketts, Jason W.; Lowry, Anthony R.

    2016-02-01

    The discovery of oceanic black (and white) smokers revolutionized our understanding of mid-ocean ridges and led to the recognition of new organisms and ecosystems. Continental smokers, defined here to include a broad range of carbonic springs, hot springs, and fumaroles that vent mantle-derived fluids in continental settings, exhibit many of the same processes of heat and mass transfer and ecosystem niche differentiation. Helium isotope (3He/4He) analyses indicate that widespread mantle degassing is taking place in the western U.S.A., and that variations in mantle helium values correlate best with low seismic-velocity domains in the mantle and lateral contrasts in mantle velocity rather than crustal parameters such as GPS, proximity to volcanoes, crustal velocity, or composition. Microbial community analyses indicate that these springs can host novel microorganisms. A targeted analysis of four springs in New Mexico yield the first published occurrence of chemolithoautotrophic Zetaproteobacteria in a continental setting. These observations lead to two linked hypotheses: that mantle-derived volatiles transit through conduits in extending continental lithosphere preferentially above and at the edges of mantle low velocity domains. High CO2 and other constituents ultimately derived from mantle volatiles drive water-rock interactions and heterogeneous fluid mixing that help structure diverse and distinctive microbial communities.

  10. Global energy / CO2 projections

    International Nuclear Information System (INIS)

    Sinyak, Y.

    1990-09-01

    Section headings are: (1) Social and economic problems of the 21 st century and the role of energy supply systems (2) Energy-environment interactions as a central point of energy research activities (3) New ways of technological progress and its impacts on energy demand and supply (4) Long-term global energy projections (5) Comparative analysis of global long-term energy / CO 2 studies (6) Conclusions. The author shows that, in order to alleviate the negative impacts of energy systems on the climate, it will be necessary to undertake tremendous efforts to improve the energy use efficiency, to drastically change the primary energy mix, and, at the same time, to take action to reduce greenhouse emissions from other sources and increase the CO 2 sink through enhanced reforestation. (Quittner)

  11. CO2 Acquisition Membrane (CAM)

    Science.gov (United States)

    Mason, Larry W.; Way, J. Douglas; Vlasse, Marcus

    2003-01-01

    The objective of CAM is to develop, test, and analyze thin film membrane materials for separation and purification of carbon dioxide (CO2) from mixtures of gases, such as those found in the Martian atmosphere. The membranes are targeted toward In Situ Resource Utilization (ISRU) applications that will operate in extraterrestrial environments and support future unmanned and human space missions. A primary application is the Sabatier Electrolysis process that uses Mars atmosphere CO2 as raw material for producing water, oxygen, and methane for rocket fuel and habitat support. Other applications include use as an inlet filter to collect and concentrate Mars atmospheric argon and nitrogen gases for habitat pressurization, and to remove CO2 from breathing gases in Closed Environment Life Support Systems (CELSS). CAM membrane materials include crystalline faujasite (FAU) zeolite and rubbery polymers such as silicone rubber (PDMS) that have been shown in the literature and via molecular simulation to favor adsorption and permeation of CO2 over nitrogen and argon. Pure gas permeation tests using commercial PDMS membranes have shown that both CO2 permeance and the separation factor relative to other gases increase as the temperature decreases, and low (Delta)P(Sub CO2) favors higher separation factors. The ideal CO2/N2 separation factor increases from 7.5 to 17.5 as temperature decreases from 22 C to -30 C. For gas mixtures containing CO2, N2, and Ar, plasticization decreased the separation factors from 4.5 to 6 over the same temperature range. We currently synthesize and test our own Na(+) FAU zeolite membranes using standard formulations and secondary growth methods on porous alumina. Preliminary tests with a Na(+) FAU membrane at 22 C show a He/SF6 ideal separation factor of 62, exceeding the Knudsen diffusion selectivity by an order of magnitude. This shows that the membrane is relatively free from large defects and associated non-selective (viscous flow) transport

  12. Fang CO2 med Aminosyrer

    DEFF Research Database (Denmark)

    Lerche, Benedicte Mai

    2010-01-01

    Med såkaldte “carbon capture-teknikker” er det muligt at rense røgen fra kulfyrede kraftværker, således at den er næsten helt fri for drivhusgassen CO2. Kunsten er at gøre processen tilstrækkeligt billig. Et lovende fangstredskab i denne proces er aminosyrer.......Med såkaldte “carbon capture-teknikker” er det muligt at rense røgen fra kulfyrede kraftværker, således at den er næsten helt fri for drivhusgassen CO2. Kunsten er at gøre processen tilstrækkeligt billig. Et lovende fangstredskab i denne proces er aminosyrer....

  13. CO2 reduction by dematerialization

    Energy Technology Data Exchange (ETDEWEB)

    Hekkert, M.P. [Department of Innovation Studies, Copernicus Institute, Utrecht University, Utrecht (Netherlands)

    2002-04-01

    Current policy for the reduction of greenhouse gases is mainly concerned with a number of types of solutions: energy saving, shifting to the use of low-carbon fuels and the implementation of sustainable energy technologies. Recent research has shown that a strategy directed at a more efficient use of materials could make a considerable contribution to reducing CO2 emissions. Moreover, the costs to society as a whole of such a measure appear to be very low.

  14. Outsourcing CO2 within China.

    Science.gov (United States)

    Feng, Kuishuang; Davis, Steven J; Sun, Laixiang; Li, Xin; Guan, Dabo; Liu, Weidong; Liu, Zhu; Hubacek, Klaus

    2013-07-09

    Recent studies have shown that the high standard of living enjoyed by people in the richest countries often comes at the expense of CO2 emissions produced with technologies of low efficiency in less affluent, developing countries. Less apparent is that this relationship between developed and developing can exist within a single country's borders, with rich regions consuming and exporting high-value goods and services that depend upon production of low-cost and emission-intensive goods and services from poorer regions in the same country. As the world's largest emitter of CO2, China is a prominent and important example, struggling to balance rapid economic growth and environmental sustainability across provinces that are in very different stages of development. In this study, we track CO2 emissions embodied in products traded among Chinese provinces and internationally. We find that 57% of China's emissions are related to goods that are consumed outside of the province where they are produced. For instance, up to 80% of the emissions related to goods consumed in the highly developed coastal provinces are imported from less developed provinces in central and western China where many low-value-added but high-carbon-intensive goods are produced. Without policy attention to this sort of interprovincial carbon leakage, the less developed provinces will struggle to meet their emissions intensity targets, whereas the more developed provinces might achieve their own targets by further outsourcing. Consumption-based accounting of emissions can thus inform effective and equitable climate policy within China.

  15. Intense magmatic degassing through the lake of Copahue volcano, 2013-2014

    Science.gov (United States)

    Tamburello, G.; Agusto, M.; Caselli, A.; Tassi, F.; Vaselli, O.; Calabrese, S.; Rouwet, D.; Capaccioni, B.; Di Napoli, R.; Cardellini, C.; Chiodini, G.; Bitetto, M.; Brusca, L.; Bellomo, S.; Aiuppa, A.

    2015-09-01

    Here we report on the first assessment of volatile fluxes from the hyperacid crater lake hosted within the summit crater of Copahue, a very active volcano on the Argentina-Chile border. Our observations were performed using a variety of in situ and remote sensing techniques during field campaigns in March 2013, when the crater hosted an active fumarole field, and in March 2014, when an acidic volcanic lake covered the fumarole field. In the latter campaign, we found that 566 to 1373 t d-1 of SO2 were being emitted from the lake in a plume that appeared largely invisible. This, combined with our derived bulk plume composition, was converted into flux of other volcanic species (H2O ~ 10989 t d-1, CO2 ~ 638 t d-1, HCl ~ 66 t d-1, H2 ~ 3.3 t d-1, and HBr ~ 0.05 t d-1). These levels of degassing, comparable to those seen at many open-vent degassing arc volcanoes, were surprisingly high for a volcano hosting a crater lake. Copahue's unusual degassing regime was also confirmed by the chemical composition of the plume that, although issuing from a hot (65°C) lake, preserves a close-to-magmatic signature. EQ3/6 models of gas-water-rock interaction in the lake were able to match observed compositions and demonstrated that magmatic gases emitted to the atmosphere were virtually unaffected by scrubbing of soluble (S and Cl) species. Finally, the derived large H2O flux (10,988 t d-1) suggested a mechanism in which magmatic gas stripping drove enhanced lake water evaporation, a process likely common to many degassing volcanic lakes worldwide.

  16. Capture, transport and storage of CO2

    International Nuclear Information System (INIS)

    De Boer, B.

    2008-01-01

    The emission of greenhouse gas CO2 in industrial processes and electricity production can be reduced on a large scale. Available techniques include post-combustion, pre-combustion, the oxy-fuel process, CO2 fixation in industrial processes and CO2 mineralization. In the Netherlands, plans for CO2 capture are not developing rapidly (CCS - carbon capture and storage). [mk] [nl

  17. Ground-Based Remote Sensing of Volcanic CO2 Fluxes at Solfatara (Italy—Direct Versus Inverse Bayesian Retrieval

    Directory of Open Access Journals (Sweden)

    Manuel Queißer

    2018-01-01

    Full Text Available CO2 is the second most abundant volatile species of degassing magma. CO2 fluxes carry information of incredible value, such as periods of volcanic unrest. Ground-based laser remote sensing is a powerful technique to measure CO2 fluxes in a spatially integrated manner, quickly and from a safe distance, but it needs accurate knowledge of the plume speed. The latter is often difficult to estimate, particularly for complex topographies. So, a supplementary or even alternative way of retrieving fluxes would be beneficial. Here, we assess Bayesian inversion as a potential technique for the case of the volcanic crater of Solfatara (Italy, a complex terrain hosting two major CO2 degassing fumarolic vents close to a steep slope. Direct integration of remotely sensed CO2 concentrations of these vents using plume speed derived from optical flow analysis yielded a flux of 717 ± 121 t day−1, in agreement with independent measurements. The flux from Bayesian inversion based on a simple Gaussian plume model was in excellent agreement under certain conditions. In conclusion, Bayesian inversion is a promising retrieval tool for CO2 fluxes, especially in situations where plume speed estimation methods fail, e.g., optical flow for transparent plumes. The results have implications beyond volcanology, including ground-based remote sensing of greenhouse gases and verification of satellite soundings.

  18. RODZAJE METOD SEKWESTRACJI CO2

    Directory of Open Access Journals (Sweden)

    Zofia LUBAŃSKA

    Full Text Available Z pojęciem ochrony środowiska wiąże się bardzo szeroko w ostatnim czasie omawiane zagadnienie dotyczące ograniczenia emisji CO2. Konsekwencją globalnych zmian klimatu wywołanego przez ludzi jest wzrost stężenia atmosferycznego gazów cieplarnianych, które powodują nasilający się efekt cieplarniany. Wzrasta na świecie liczba ludności, a co za tym idzie wzrasta konsumpcja na jednego mieszkańca, szczególnie w krajach szeroko rozwiniętych gospodarczo. Protokół z Kioto ściśle określa działania jakie należy podjąć w celu zmniejszenia stężenia dwutlenku węgla w atmosferze. Pomimo maksymalnej optymalizacji procesu spalania paliw kopalnianych wykorzystywanych do produkcji energii, zastosowania odnawialnych źródeł energii zmiana klimatu jest nieunikniona i konsekwentnie będzie postępować przez kolejne dekady. Prognozuje się, że duże znaczenie odegra nowoczesna technologia, która ma za zadanie wychwycenie CO2 a następnie składowanie go w odpowiednio wybranych formacjach geologicznych (CCS- Carbon Capture and Storage. Eksperci są zgodni, że ta technologia w niedalekiej przyszłości stanie się rozwiązaniem pozwalającym ograniczyć ogromną ilość emisji CO2 pochodzącą z procesów wytwarzania energii z paliw kopalnych. Z analiz Raportu IPCC wynika, iż technologia CSS może się przyczynić do ok. 20% redukcji emisji dwutlenku węgla przewidzianej do 2050 roku [3]. Zastosowanie jej napotyka na wiele barier, nie tylko technologicznych i ekonomicznych, ale także społecznych. Inną metodą dającą ujemne źródło emisji CO2 jest możliwość wykorzystania obszarów leśnych o odpowiedniej strukturze drzewostanu. Środkiem do tego celu, oprócz ograniczenia zużycia emisjogennych paliw kopalnych (przy zachowaniu zasad zrównoważonego rozwoju może być intensyfikacja zalesień. Zwiększanie lesistości i prawidłowa gospodarka leśna należy do najbardziej efektywnych sposobów kompensowania

  19. Dolomite decomposition under CO2

    International Nuclear Information System (INIS)

    Guerfa, F.; Bensouici, F.; Barama, S.E.; Harabi, A.; Achour, S.

    2004-01-01

    Full text.Dolomite (MgCa (CO 3 ) 2 is one of the most abundant mineral species on the surface of the planet, it occurs in sedimentary rocks. MgO, CaO and Doloma (Phase mixture of MgO and CaO, obtained from the mineral dolomite) based materials are attractive steel-making refractories because of their potential cost effectiveness and world wide abundance more recently, MgO is also used as protective layers in plasma screen manufacture ceel. The crystal structure of dolomite was determined as rhombohedral carbonates, they are layers of Mg +2 and layers of Ca +2 ions. It dissociates depending on the temperature variations according to the following reactions: MgCa (CO 3 ) 2 → MgO + CaO + 2CO 2 .....MgCa (CO 3 ) 2 → MgO + Ca + CaCO 3 + CO 2 .....This latter reaction may be considered as a first step for MgO production. Differential thermal analysis (DTA) are used to control dolomite decomposition and the X-Ray Diffraction (XRD) was used to elucidate thermal decomposition of dolomite according to the reaction. That required samples were heated to specific temperature and holding times. The average particle size of used dolomite powders is 0.3 mm, as where, the heating temperature was 700 degree celsius, using various holding times (90 and 120 minutes). Under CO 2 dolomite decomposed directly to CaCO 3 accompanied by the formation of MgO, no evidence was offered for the MgO formation of either CaO or MgCO 3 , under air, simultaneous formation of CaCO 3 , CaO and accompanied dolomite decomposition

  20. Outsourcing CO2 within China

    Science.gov (United States)

    Feng, Kuishuang; Davis, Steven J.; Sun, Laixiang; Li, Xin; Guan, Dabo; Liu, Weidong; Liu, Zhu; Hubacek, Klaus

    2013-01-01

    Recent studies have shown that the high standard of living enjoyed by people in the richest countries often comes at the expense of CO2 emissions produced with technologies of low efficiency in less affluent, developing countries. Less apparent is that this relationship between developed and developing can exist within a single country’s borders, with rich regions consuming and exporting high-value goods and services that depend upon production of low-cost and emission-intensive goods and services from poorer regions in the same country. As the world’s largest emitter of CO2, China is a prominent and important example, struggling to balance rapid economic growth and environmental sustainability across provinces that are in very different stages of development. In this study, we track CO2 emissions embodied in products traded among Chinese provinces and internationally. We find that 57% of China’s emissions are related to goods that are consumed outside of the province where they are produced. For instance, up to 80% of the emissions related to goods consumed in the highly developed coastal provinces are imported from less developed provinces in central and western China where many low–value-added but high–carbon-intensive goods are produced. Without policy attention to this sort of interprovincial carbon leakage, the less developed provinces will struggle to meet their emissions intensity targets, whereas the more developed provinces might achieve their own targets by further outsourcing. Consumption-based accounting of emissions can thus inform effective and equitable climate policy within China. PMID:23754377

  1. Carbon dioxide degassing in fresh and saline water I: Degassing performance of a cascade column

    DEFF Research Database (Denmark)

    Moran, Damian

    2010-01-01

    A study was undertaken to measure carbon dioxide degassing in a cascade column operating with both fresh (0‰) and saline water (35‰ NaCl) at 15 °C. The cascade column contained bio-block type packing material, was 1.7 m long in each dimension, and was tested both with and without countercurrent a...

  2. Trading CO2 emission; Verhandelbaarheid van CO2-emissies

    Energy Technology Data Exchange (ETDEWEB)

    De Waal, J.F.; Looijenga, A.; Moor, R.; Wissema, E.W.J. [Afdeling Energie, Ministerie van VROM, The Hague (Netherlands)

    2000-06-01

    Systems for CO2-emission trading can take many shapes as developments in Europe show. European developments for emission trading tend to comprehend cap and-trade systems for large emission sources. In the Netherlands a different policy is in preparation. A trading system for sheltered sectors with an option to buy reductions from exposed sectors will be further developed by a Commission, appointed by the minister of environment. Exposed sectors are committed to belong to the top of the world on the area of energy-efficiency. The authors point out that a cap on the distribution of energy carriers natural gas, electricity and fuel seems to be an interesting option to shape the trade scheme. A cap on the distribution of electricity is desirable, but not easy to implement. The possible success of the system depends partly on an experiment with emission reductions. 10 refs.

  3. Geological storage of CO2

    International Nuclear Information System (INIS)

    Czernichowski-Lauriol, I.

    2005-01-01

    The industrial storage of CO 2 is comprised of three steps: - capture of CO 2 where it is produced (power plants, cement plants, etc.); - transport (pipe lines or boats); - storage, mainly underground, called geological sequestration... Three types of reservoirs are considered: - salted deep aquifers - they offer the biggest storage capacity; - exhausted oil and gas fields; - non-exploited deep coal mine streams. The two latter storage types may allow the recovery of sellable products, which partially or totally offsets the storage costs. This process is largely used in the petroleum industry to improve the productivity of an oil field, and is called FOR (Enhanced Oil Recovery). A similar process is applied in the coal mining industry to recover the imprisoned gas, and is called ECBM (Enhanced Coal Bed methane). Two storage operations have been initiated in Norway and in Canada, as well as research programmes in Europe, North America, Australia and Japan. International organisations to stimulate this technology have been created such as the 'Carbon Sequestration Leadership Forum' and 'the Intergovernmental Group for Climate Change'. This technology will be taken into account in the instruments provided by the Tokyo Protocol. (author)

  4. Support and Size Effects of Activated Hydrotalcites for Precombustion CO2 Capture

    NARCIS (Netherlands)

    Meis, N.N.A.H.; Bitter, J.H.; de Jong, K.P.

    2013-01-01

    A series of Mg−Al hydrotalcites (HTs) with lateral platelet sizes ranging from 40 nm to 2 μm were prepared hydrothermally. Small HT platelets (20 nm) were obtained by deposition onto a carbon nanofiber (CNF) support. The CO2 sorption capacity at 523 K for the activated unsupported HT was low (0.1

  5. Denitrogenation model for vacuum tank degasser

    Science.gov (United States)

    Gobinath, R.; Vetrivel Murugan, R.

    2018-02-01

    Nitrogen in steel is both beneficial and detrimental depending on grade of steel and its application. To get desired low nitrogen during vacuum degassing process, VD parameters namely vacuum level, argon flow rate and holding time has to optimized depending upon initial nitrogen level. In this work a mathematical model to simulate nitrogen removal in tank degasser is developed and how various VD parameters affects nitrogen removal is studied. Ladle water model studies with bottom purging have shown two distinct flow regions, namely the plume region and the outside plume region. The two regions are treated as two separate reactors exchanging mass between them and complete mixing is assumed in both the reactors. In the plume region, transfer of nitrogen to single bubble is simulated. At the gas-liquid metal interface (bubble interface) thermodynamic equilibrium is assumed and the transfer of nitrogen from bulk liquid metal in the plume region to the gas-metal interface is obtained using mass transport principles. The model predicts variation of Nitrogen content in both the reactors with time. The model is validated with industrial process and the predicted results were found to have fair agreement with the measured results.

  6. Soil CO2 emissions as a proxy for heat and mass flow assessment, Taupō Volcanic Zone, New Zealand

    Science.gov (United States)

    Bloomberg, S.; Werner, Cynthia A.; Rissmann, C.F.; Mazot, A.; Horton, Travis B.; Gravley, D; Kennedy, B.; Oze, C

    2014-01-01

    The quantification of heat and mass flow between deep reservoirs and the surface is important for understanding magmatic and hydrothermal systems. Here, we use high-resolution measurement of carbon dioxide flux (φCO2) and heat flow at the surface to characterize the mass (CO2 and steam) and heat released to the atmosphere from two magma-hydrothermal systems. Our soil gas and heat flow surveys at Rotokawa and White Island in the Taupō Volcanic Zone, New Zealand, include over 3000 direct measurements of φCO2 and soil temperature and 60 carbon isotopic values on soil gases. Carbon dioxide flux was separated into background and magmatic/hydrothermal populations based on the measured values and isotopic characterization. Total CO2 emission rates (ΣCO2) of 441 ± 84 t d−1 and 124 ± 18 t d−1were calculated for Rotokawa (2.9 km2) and for the crater floor at White Island (0.3 km2), respectively. The total CO2 emissions differ from previously published values by +386 t d−1 at Rotokawa and +25 t d−1 at White Island, demonstrating that earlier research underestimated emissions by 700% (Rotokawa) and 25% (White Island). These differences suggest that soil CO2 emissions facilitate more robust estimates of the thermal energy and mass flux in geothermal systems than traditional approaches. Combining the magmatic/hydrothermal-sourced CO2 emission (constrained using stable isotopes) with reservoir H2O:CO2mass ratios and the enthalpy of evaporation, the surface expression of thermal energy release for the Rotokawa hydrothermal system (226 MWt) is 10 times greater than the White Island crater floor (22.5 MWt).

  7. Alberta industrial synergy CO2 programs initiative

    International Nuclear Information System (INIS)

    Yildirim, E.

    1998-01-01

    The various industrial sectors within Alberta produce about 350,000 tonnes of CO 2 per day. This presentation was concerned with how this large volume and high concentration of CO 2 can be used in industrial and agricultural applications, because every tonne of CO 2 used for such purposes is a tonne that does not end up in the atmosphere. There is a good potential for an industrial synergy between the producers and users of CO 2 . The Alberta Industrial Synergy CO 2 Programs Initiative was established to ultimately achieve a balance between the producers of CO 2 and the users of CO 2 by creating ways to use the massive quantities of CO 2 produced by Alberta's hydrocarbon-based economy. The Alberta CO 2 Research Steering Committee was created to initiate and support CO 2 programs such as: (1) CO 2 use in enhanced oil recovery, (2) creation of a CO 2 production inventory, (3) survey of CO 2 users and potential users, (4) investigation of process issues such as power generation, oil sands and cement manufacturing, and (5) biofixation by plants, (6) other disposal options (e.g. in depleted oil and gas reservoirs, in aquifers, in tailings ponds, in coal beds). The single most important challenge was identified as 'rationalizing the formation of the necessary infrastructure'. Failing to do that will greatly impede efforts directed towards CO 2 utilization

  8. 75 FR 67100 - Superalloy Degassed Chromium From Japan

    Science.gov (United States)

    2010-11-01

    ... Chromium From Japan AGENCY: United States International Trade Commission. ACTION: Institution of a five-year review concerning the antidumping duty order on superalloy degassed chromium from Japan. SUMMARY... order on superalloy degassed chromium from Japan would be likely to lead to continuation or recurrence...

  9. 76 FR 8773 - Superalloy Degassed Chromium From Japan

    Science.gov (United States)

    2011-02-15

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-1090 (Review)] Superalloy Degassed Chromium From Japan AGENCY: United States International Trade Commission. ACTION: Termination of five-year... revocation of the antidumping duty order on superalloy degassed chromium from Japan would be likely to lead...

  10. Secular Variations of Soil CO2 Efflux at Santa Ana-Izalco-Coatepeque Volcanic Complex, El Salvador, Central America

    Science.gov (United States)

    Olmos, R.; Barahona, F.; Cartagena, R.; Soriano, T.; Salazar, J.; Hernandez, P.; Perez, N.; Lopez, D.

    2002-12-01

    The Santa Ana-Izalco-Coatepeque volcanic complex (2,365 m elevation), located 40 Km west of San Salvador, consists of the Coatepeque collapse caldera (a 6.5 x 10.5 Km elliptical depression), the Santa Ana and Izalco stratovolcanoes, as well as numerous cinder cones and explosion craters. The summit of the Santa Ana volcano contains an acid lake where hot springs, gas bubbling and intense fumarolic emissions occur. A volcanic plume, usually driven by the NE trades, may be seen rising up to 500 m from the summit crater of the Santa Ana volcano. The goal of this study is to provide a multidisciplinary approach for the volcanic surveillance by means of performing geochemical continuous monitoring of diffuse CO2 emission rate in addition to seismic monitoring. Temporal variations of soil CO2 efflux measured at Cerro Pacho dome, Coatepeque caldera, by means of the accumulation chamber method and using a CO2 efflux continuous monitoring station developed by WEST Systems (Italy). From May 2001 till May 2002, CO2 efflux ranged from 4.3 to 327 gm-2d-1, with a median value of 98 and a quartile range of 26 gm-2d-1. Two distinct diffuse CO2 degassing periods have been observed: (1) an increasing trend from May to July 2001, and (2) a stationary period from November 2001 to May 2002. The increasing-trend period may be due to the anomalous plume degassing at the Santa Ana volcano during 2001 and soon after the January and February 2001 earthquakes. Temporal variations of CO2 efllux during the second period seem to be coupled with those of barometric pressure and wind speed at different time scales, though most of the variance is contained at diurnal and semi-diurnal frequencies. These observations can help to explain the existence of a persistent behavior (Hurst exponent, H=0.934 +/- 0.0039) within the diffuse CO2 degassing phenomena. However, further observations are in progress to understand the long-term memory of diffuse CO2 degassing at the Santa Ana volcanic complex.

  11. Reducing CO2-Emission by using Eco-Cements

    Science.gov (United States)

    Voit, K.; Bergmeister, K.; Janotka, I.

    2012-04-01

    CO2 concentration in the air is rising constantly. Globally, cement companies are emitting nearly two billion tonnes/year of CO2 (or around 6 to 7 % of the planet's total CO2 emissions) by producing portland cement clinker. At this pace, by 2025 the cement industry will be emitting CO2 at a rate of 3.5 billion tones/year causing enormous environmental damage (Shi et al., 2011; Janotka et al., 2012). At the dawn of the industrial revolution in the mid-eighteenth century the concentration of CO2 was at a level of ca. 280 ppm. 200 years later at the time of World War II the CO2 level had risen to 310 ppm what results in a rate of increase of 0,15 ppm per year for that period (Shi et al., 2011). In November 2011 the CO2 concentration reached a value of 391 ppm (NOAA Earth System Research Laboratory, 2011), a rise of ca. 81 ppm in 66 years and an increased rate of around 1,2 ppm/year respectively. In the same period cement production in tons of cement has multiplied by a factor of ca. 62 (Kelly & Oss, US Geological Survey, 2010). Thus new CO2-saving eco-cement types are gaining in importance. In these cement types the energy-consuming portland cement clinker is partially replaced by latent hydraulic additives such as blast furnace slag, fly ash or zeolite. These hydraulic additives do not need to be fired in the rotary furnace. They ony need to be pulverized to the required grain size and added to the ground portland cement clinker. Hence energy is saved by skipping the engery-consuming firing process, in addition there is no CO2-degassing as there is in the case of lime burning. Therefore a research project between Austria and Slovakia, funded by the EU (Project ENVIZEO), was initiated in 2010. The main goal of this project is to develop new CEM V eco-types of cements and certificate them for common usage. CEM V is a portland clinker saving cement kind that allows the reduction of clinker to a proportion of 40-64% for CEM V/A and 20-39% for CEM V/B respectively by the

  12. Carbon flow from volcanic CO2 into soil microbial communities of a wetland mofette

    Science.gov (United States)

    Beulig, Felix; Heuer, Verena B.; Akob, Denise M.; Viehweger, Bernhard; Elvert, Marcus; Herrmann, Martina; Hinrichs, Kai-Uwe; Küsel, Kirsten

    2015-01-01

    Effects of extremely high carbon dioxide (CO2) concentrations on soil microbial communities and associated processes are largely unknown. We studied a wetland area affected by spots of subcrustal CO2 degassing (mofettes) with focus on anaerobic autotrophic methanogenesis and acetogenesis because the pore gas phase was largely hypoxic. Compared with a reference soil, the mofette was more acidic (ΔpH ~0.8), strongly enriched in organic carbon (up to 10 times), and exhibited lower prokaryotic diversity. It was dominated by methanogens and subdivision 1Acidobacteria, which likely thrived under stable hypoxia and acidic pH. Anoxic incubations revealed enhanced formation of acetate and methane (CH4) from hydrogen (H2) and CO2 consistent with elevated CH4 and acetate levels in the mofette soil. 13CO2 mofette soil incubations showed high label incorporations with ~512 ng13C g (dry weight (dw)) soil−1 d−1 into the bulk soil and up to 10.7 ng 13C g (dw) soil−1 d−1 into almost all analyzed bacterial lipids. Incorporation of CO2-derived carbon into archaeal lipids was much lower and restricted to the first 10 cm of the soil. DNA-SIP analysis revealed that acidophilic methanogens affiliated withMethanoregulaceae and hitherto unknown acetogens appeared to be involved in the chemolithoautotrophic utilization of 13CO2. Subdivision 1 Acidobacteriaceae assimilated 13CO2 likely via anaplerotic reactions because Acidobacteriaceae are not known to harbor enzymatic pathways for autotrophic CO2 assimilation. We conclude that CO2-induced geochemical changes promoted anaerobic and acidophilic organisms and altered carbon turnover in affected soils.

  13. Carbon flow from volcanic CO2 into soil microbial communities of a wetland mofette.

    Science.gov (United States)

    Beulig, Felix; Heuer, Verena B; Akob, Denise M; Viehweger, Bernhard; Elvert, Marcus; Herrmann, Martina; Hinrichs, Kai-Uwe; Küsel, Kirsten

    2015-03-01

    Effects of extremely high carbon dioxide (CO2) concentrations on soil microbial communities and associated processes are largely unknown. We studied a wetland area affected by spots of subcrustal CO2 degassing (mofettes) with focus on anaerobic autotrophic methanogenesis and acetogenesis because the pore gas phase was largely hypoxic. Compared with a reference soil, the mofette was more acidic (ΔpH ∼0.8), strongly enriched in organic carbon (up to 10 times), and exhibited lower prokaryotic diversity. It was dominated by methanogens and subdivision 1 Acidobacteria, which likely thrived under stable hypoxia and acidic pH. Anoxic incubations revealed enhanced formation of acetate and methane (CH4) from hydrogen (H2) and CO2 consistent with elevated CH4 and acetate levels in the mofette soil. (13)CO2 mofette soil incubations showed high label incorporations with ∼512 ng (13)C g (dry weight (dw)) soil(-1) d(-1) into the bulk soil and up to 10.7 ng (13)C g (dw) soil(-1) d(-1) into almost all analyzed bacterial lipids. Incorporation of CO2-derived carbon into archaeal lipids was much lower and restricted to the first 10 cm of the soil. DNA-SIP analysis revealed that acidophilic methanogens affiliated with Methanoregulaceae and hitherto unknown acetogens appeared to be involved in the chemolithoautotrophic utilization of (13)CO2. Subdivision 1 Acidobacteriaceae assimilated (13)CO2 likely via anaplerotic reactions because Acidobacteriaceae are not known to harbor enzymatic pathways for autotrophic CO2 assimilation. We conclude that CO2-induced geochemical changes promoted anaerobic and acidophilic organisms and altered carbon turnover in affected soils.

  14. Using a laser-based CO2 carbon isotope analyser to investigate gas transfer in geological media

    International Nuclear Information System (INIS)

    Guillon, S.; Pili, E.; Agrinier, P.

    2012-01-01

    CO 2 stable carbon isotopes are very attractive in environmental research to investigate both natural and anthropogenic carbon sources. Laser-based CO 2 carbon isotope analysis provides continuous measurement at high temporal resolution and is a promising alternative to isotope ratio mass spectrometry (IRMS). We performed a thorough assessment of a commercially available CO 2 Carbon Isotope Analyser (CCIA DLT-100, Los Gatos Research) that allows in situ measurement of C-13 in CO 2 . Using a set of reference gases of known CO 2 concentration and carbon isotopic composition, we evaluated the precision, long-term stability, temperature sensitivity and concentration dependence of the analyser. Despite good precision calculated from Allan variance (5.0 ppm for CO 2 concentration, and 0.05 per thousand for δC-13 at 60 s averaging), real performances are altered by two main sources of error: temperature sensitivity and dependence of C-13 on CO 2 concentration. Data processing is required to correct for these errors. Following application of these corrections, we achieve an accuracy of 8.7 ppm for CO 2 concentration and 1.3 per thousand for δC-13, which is worse compared to mass spectrometry performance, but still allowing field applications. With this portable analyser we measured CO 2 flux degassed from rock in an underground tunnel. The obtained carbon isotopic composition agrees with IRMS measurement, and can be used to identify the carbon source. (authors)

  15. ISLSCP II Globalview: Atmospheric CO2 Concentrations

    Data.gov (United States)

    National Aeronautics and Space Administration — The GlobalView Carbon Dioxide (CO2) data product contains synchronized and smoothed time series of atmospheric CO2 concentrations at selected sites that were created...

  16. Time-Resolved Gravimetric Method To Assess Degassing of Roasted Coffee.

    Science.gov (United States)

    Smrke, Samo; Wellinger, Marco; Suzuki, Tomonori; Balsiger, Franz; Opitz, Sebastian E W; Yeretzian, Chahan

    2018-05-30

    During the roasting of coffee, thermally driven chemical reactions lead to the formation of gases, of which a large fraction is carbon dioxide (CO 2 ). Part of these gases is released during roasting while part is retained inside the porous structure of the roasted beans and is steadily released during storage or more abruptly during grinding and extraction. The release of CO 2 during the various phases from roasting to consumption is linked to many important properties and characteristics of coffee. It is an indicator for freshness, plays an important role in shelf life and in packaging, impacts the extraction process, is involved in crema formation, and may affect the sensory profile in the cup. Indeed, and in view of the multiple roles it plays, CO 2 is a much underappreciated and little examined molecule in coffee. Here, we introduce an accurate, quantitative, and time-resolved method to measure the release kinetics of gases from whole beans and ground coffee using a gravimetric approach. Samples were placed in a container with a fitted capillary to allow gases to escape. The time-resolved release of gases was measured via the weight loss of the container filled with coffee. Long-term stability was achieved using a customized design of a semimicro balance, including periodic and automatic zero value measurements and calibration procedures. The novel gravimetric methodology was applied to a range of coffee samples: (i) whole Arabica beans and (ii) ground Arabica and Robusta, roasted to different roast degrees and at different speeds (roast air temperatures). Modeling the degassing rates allowed structural and mechanistic interpretation of the degassing process.

  17. Bioelectrochemical conversion of CO2 to chemicals

    NARCIS (Netherlands)

    Bajracharya, Suman; Vanbroekhoven, Karolien; Buisman, Cees J.N.; Strik, David P.B.T.B.; Pant, Deepak

    2017-01-01

    The recent concept of microbial electrosynthesis (MES) has evolved as an electricity-driven production technology for chemicals from low-value carbon dioxide (CO2) using micro-organisms as biocatalysts. MES from CO2 comprises bioelectrochemical reduction of CO2 to multi-carbon organic compounds

  18. CO 2-rich komatiitic melt inclusions in Cr-spinels within beach sand from Gorgona Island, Colombia

    Science.gov (United States)

    Shimizu, Kenji; Shimizu, Nobumichi; Komiya, Tsuyoshi; Suzuki, Katsuhiko; Maruyama, Shigenori; Tatsumi, Yoshiyuki

    2009-10-01

    The volatile content of komatiite is a key to constrain the thermal and chemical evolution of the deep Earth. We report the volatile contents with major and trace element compositions of ~ 80 melt inclusions in chromian spinels (Cr-spinels) from beach sands on Gorgona Island, Colombia. Gorgona Island is a ~ 90 Ma volcanic island, where picrites and the youngest komatiites known on the Earth are present. Melt inclusions are classified into three types on the basis of their host Cr-spinel compositions: low Ti (P type), high Ti with high Cr # (K1 type) and high Ti with low Cr # (K2 type). Chemical variations of melt inclusions in the Cr-spinels cover all of the island's lava types. P-type inclusions mainly occur in the picrites, K1-type in high-TiO 2 komatiites (some enriched basalts: E-basalts) and K2-type in low-TiO 2 komatiites. The H 2O and CO 2 contents of melt inclusions within Cr-spinels from the beach sand are highly variable (H 2O: 0.03-0.9 wt.%; CO 2: 40-4000 ppm). Evaluation of volatile content is not entirely successful because of compositional alterations of the original melt by degassing, seawater/brine assimilation and post-entrapment modification of certain elements and volatiles. However, the occurrence of many melt inclusions with low H 2O/K 2O ratios indicates that H 2O/K 2O of Gorgona komatiite is not much different from that of modern mid-oceanic ridge basalt (MORB) or oceanic island basalt. Trend of CO 2/Nb and Zr/Y ratios, accounted for by two-component mixing between the least degassed primary komatiite and low-CO 2/Nb evolved basalt, allow us to estimate a primary CO 2/Nb ratio of 4000 ± 2200 or a CO 2 content of 0.16 ± 0.09 wt.%. The determined CO 2/Nb ratio is unusually high, compared to that of MORB (530). Although the presence of CO 2 in the Gorgona komatiite does not affect the magma generation temperature, CO 2 degassing may have contributed to the eruption of high-density magmas. High CO 2/Nb and the relatively anhydrous nature of

  19. Forest succession at elevated CO2; TOPICAL

    International Nuclear Information System (INIS)

    Clark, James S.; Schlesinger, William H.

    2002-01-01

    We tested hypotheses concerning the response of forest succession to elevated CO2 in the FACTS-1 site at the Duke Forest. We quantified growth and survival of naturally recruited seedlings, tree saplings, vines, and shrubs under ambient and elevated CO2. We planted seeds and seedlings to augment sample sites. We augmented CO2 treatments with estimates of shade tolerance and nutrient limitation while controlling for soil and light effects to place CO2 treatments within the context of natural variability at the site. Results are now being analyzed and used to parameterize forest models of CO2 response

  20. Residual CO2 trapping in Indiana limestone.

    Science.gov (United States)

    El-Maghraby, Rehab M; Blunt, Martin J

    2013-01-02

    We performed core flooding experiments on Indiana limestone using the porous plate method to measure the amount of trapped CO(2) at a temperature of 50 °C and two pressures: 4.2 and 9 MPa. Brine was mixed with CO(2) for equilibration, then the mixture was circulated through a sacrificial core. Porosity and permeability tests conducted before and after 884 h of continuous core flooding confirmed negligible dissolution. A trapping curve for supercritical (sc)CO(2) in Indiana showing the relationship between the initial and residual CO(2) saturations was measured and compared with that of gaseous CO(2). The results were also compared with scCO(2) trapping in Berea sandstone at the same conditions. A scCO(2) residual trapping end point of 23.7% was observed, indicating slightly less trapping of scCO(2) in Indiana carbonates than in Berea sandstone. There is less trapping for gaseous CO(2) (end point of 18.8%). The system appears to be more water-wet under scCO(2) conditions, which is different from the trend observed in Berea; we hypothesize that this is due to the greater concentration of Ca(2+) in brine at higher pressure. Our work indicates that capillary trapping could contribute to the immobilization of CO(2) in carbonate aquifers.

  1. CO2 clearance by membrane lungs.

    Science.gov (United States)

    Sun, Liqun; Kaesler, Andreas; Fernando, Piyumindri; Thompson, Alex J; Toomasian, John M; Bartlett, Robert H

    2018-05-01

    Commercial membrane lungs are designed to transfer a specific amount of oxygen per unit of venous blood flow. Membrane lungs are much more efficient at removing CO 2 than adding oxygen, but the range of CO 2 transfer is rarely reported. Commercial membrane lungs were studied with the goal of evaluating CO 2 removal capacity. CO 2 removal was measured in 4 commercial membrane lungs under standardized conditions. CO 2 clearance can be greater than 4 times that of oxygen at a given blood flow when the gas to blood flow ratio is elevated to 4:1 or 8:1. The CO 2 clearance was less dependent on surface area and configuration than oxygen transfer. Any ECMO system can be used for selective CO 2 removal.

  2. Extraction of stevia glycosides with CO2 + water, CO2 + ethanol, and CO2 + water + ethanol

    Directory of Open Access Journals (Sweden)

    A. Pasquel

    2000-09-01

    Full Text Available Stevia leaves are an important source of natural sugar substitute. There are some restrictions on the use of stevia extract because of its distinctive aftertaste. Some authors attribute this to soluble material other than the stevia glycosides, even though it is well known that stevia glycosides have to some extent a bitter taste. Therefore, the purpose of this work was to develop a process to obtain stevia extract of a better quality. The proposed process includes two steps: i Pretreatment of the leaves by SCFE; ii Extraction of the stevia glycosides by SCFE using CO2 as solvent and water and/or ethanol as cosolvent. The mean total yield for SCFE pretreatment was 3.0%. The yields for SCFE with cosolvent of stevia glycosides were below 0.50%, except at 120 bar, 16°C, and 9.5% (molar of water. Under this condition, total yield was 3.4%. The quality of the glycosidic fraction with respect to its capacity as sweetener was better for the SCFE extract as compared to extract obtained by the conventional process. The overall extraction curves were well described by the Lack extended model.

  3. Variability in soil CO2 production and surface CO2 efflux across riparian-hillslope transitions

    Science.gov (United States)

    Vincent Jerald. Pacific

    2007-01-01

    The spatial and temporal controls on soil CO2 production and surface CO2 efflux have been identified as an outstanding gap in our understanding of carbon cycling. I investigated both the spatial and temporal variability of soil CO2 concentrations and surface CO2 efflux across eight topographically distinct riparian-hillslope transitions in the ~300 ha subalpine upper-...

  4. CO2 flux from Javanese mud volcanism.

    Science.gov (United States)

    Queißer, M; Burton, M R; Arzilli, F; Chiarugi, A; Marliyani, G I; Anggara, F; Harijoko, A

    2017-06-01

    Studying the quantity and origin of CO 2 emitted by back-arc mud volcanoes is critical to correctly model fluid-dynamical, thermodynamical, and geochemical processes that drive their activity and to constrain their role in the global geochemical carbon cycle. We measured CO 2 fluxes of the Bledug Kuwu mud volcano on the Kendeng Fold and thrust belt in the back arc of Central Java, Indonesia, using scanning remote sensing absorption spectroscopy. The data show that the expelled gas is rich in CO 2 with a volume fraction of at least 16 vol %. A lower limit CO 2 flux of 1.4 kg s -1 (117 t d -1 ) was determined, in line with the CO 2 flux from the Javanese mud volcano LUSI. Extrapolating these results to mud volcanism from the whole of Java suggests an order of magnitude total CO 2 flux of 3 kt d -1 , comparable with the expected back-arc efflux of magmatic CO 2 . After discussing geochemical, geological, and geophysical evidence we conclude that the source of CO 2 observed at Bledug Kuwu is likely a mixture of thermogenic, biogenic, and magmatic CO 2 , with faulting controlling potential pathways for magmatic fluids. This study further demonstrates the merit of man-portable active remote sensing instruments for probing natural gas releases, enabling bottom-up quantification of CO 2 fluxes.

  5. Modeling of CO2 storage in aquifers

    International Nuclear Information System (INIS)

    Savioli, Gabriela B; Santos, Juan E

    2011-01-01

    Storage of CO 2 in geological formations is a means of mitigating the greenhouse effect. Saline aquifers are a good alternative as storage sites due to their large volume and their common occurrence in nature. The first commercial CO 2 injection project is that of the Sleipner field in the Utsira Sand aquifer (North Sea). Nevertheless, very little was known about the effectiveness of CO 2 sequestration over very long periods of time. In this way, numerical modeling of CO 2 injection and seismic monitoring is an important tool to understand the behavior of CO 2 after injection and to make long term predictions in order to prevent CO 2 leaks from the storage into the atmosphere. The description of CO 2 injection into subsurface formations requires an accurate fluid-flow model. To simulate the simultaneous flow of brine and CO 2 we apply the Black-Oil formulation for two phase flow in porous media, which uses the PVT data as a simplified thermodynamic model. Seismic monitoring is modeled using Biot's equations of motion describing wave propagation in fluid-saturated poroviscoelastic solids. Numerical examples of CO 2 injection and time-lapse seismics using data of the Utsira formation show the capability of this methodology to monitor the migration and dispersal of CO 2 after injection.

  6. Explaining CO2 fluctuations observed in snowpacks

    Science.gov (United States)

    Graham, Laura; Risk, David

    2018-02-01

    Winter soil carbon dioxide (CO2) respiration is a significant and understudied component of the global carbon (C) cycle. Winter soil CO2 fluxes can be surprisingly variable, owing to physical factors such as snowpack properties and wind. This study aimed to quantify the effects of advective transport of CO2 in soil-snow systems on the subdiurnal to diurnal (hours to days) timescale, use an enhanced diffusion model to replicate the effects of CO2 concentration depletions from persistent winds, and use a model-measure pairing to effectively explore what is happening in the field. We took continuous measurements of CO2 concentration gradients and meteorological data at a site in the Cape Breton Highlands of Nova Scotia, Canada, to determine the relationship between wind speeds and CO2 levels in snowpacks. We adapted a soil CO2 diffusion model for the soil-snow system and simulated stepwise changes in transport rate over a broad range of plausible synthetic cases. The goal was to mimic the changes we observed in CO2 snowpack concentration to help elucidate the mechanisms (diffusion, advection) responsible for observed variations. On subdiurnal to diurnal timescales with varying winds and constant snow levels, a strong negative relationship between wind speed and CO2 concentration within the snowpack was often identified. Modelling clearly demonstrated that diffusion alone was unable to replicate the high-frequency CO2 fluctuations, but simulations using above-atmospheric snowpack diffusivities (simulating advective transport within the snowpack) reproduced snow CO2 changes of the observed magnitude and speed. This confirmed that wind-induced ventilation contributed to episodic pulsed emissions from the snow surface and to suppressed snowpack concentrations. This study improves our understanding of winter CO2 dynamics to aid in continued quantification of the annual global C cycle and demonstrates a preference for continuous wintertime CO2 flux measurement systems.

  7. Porous Organic Polymers for CO2 Capture

    KAUST Repository

    Teng, Baiyang

    2013-05-01

    Carbon dioxide (CO2) has long been regarded as the major greenhouse gas, which leads to numerous negative effects on global environment. The capture and separation of CO2 by selective adsorption using porous materials proves to be an effective way to reduce the emission of CO2 to atmosphere. Porous organic polymers (POPs) are promising candidates for this application due to their readily tunable textual properties and surface functionalities. The objective of this thesis work is to develop new POPs with high CO2 adsorption capacities and CO2/N2 selectivities for post-combustion effluent (e.g. flue gas) treatment. We will also exploit the correlation between the CO2 capture performance of POPs and their textual properties/functionalities. Chapters Two focuses on the study of a group of porous phenolic-aldehyde polymers (PPAPs) synthesized by a catalyst-free method, the CO2 capture capacities of these PPAPs exceed 2.0 mmol/g at 298 K and 1 bar, while keeping CO2/N2 selectivity of more than 30 at the same time. Chapter Three reports the gas adsorption results of different hyper-cross-linked polymers (HCPs), which indicate that heterocyclo aromatic monomers can greatly enhance polymers’ CO2/N2 selectivities, and the N-H bond is proved to the active CO2 adsorption center in the N-contained (e.g. pyrrole) HCPs, which possess the highest selectivities of more than 40 at 273 K when compared with other HCPs. Chapter Four emphasizes on the chemical modification of a new designed polymer of intrinsic microporosity (PIM) with high CO2/N2 selectivity (50 at 273 K), whose experimental repeatability and chemical stability prove excellent. In Chapter Five, we demonstrate an improvement of both CO2 capture capacity and CO2/N2 selectivity by doping alkali metal ions into azo-polymers, which leads a promising method to the design of new porous organic polymers.

  8. Degassing Processes at Persistently Active Explosive Volcanoes

    Science.gov (United States)

    Smekens, Jean-Francois

    Among volcanic gases, sulfur dioxide (SO2) is by far the most commonly measured. More than a monitoring proxy for volcanic degassing, SO 2 has the potential to alter climate patterns. Persistently active explosive volcanoes are characterized by short explosive bursts, which often occur at periodic intervals numerous times per day, spanning years to decades. SO 2 emissions at those volcanoes are poorly constrained, in large part because the current satellite monitoring techniques are unable to detect or quantify plumes of low concentration in the troposphere. Eruption plumes also often show high concentrations of ash and/or aerosols, which further inhibit the detection methods. In this work I focus on quantifying volcanic gas emissions at persistently active explosive volcanoes and their variations over short timescales (minutes to hours), in order to document their contribution to natural SO2 flux as well as investigate the physical processes that control their behavior. In order to make these measurements, I first develop and assemble a UV ground-based instrument, and validate it against an independently measured source of SO2 at a coal-burning power plant in Arizona. I establish a measurement protocol and demonstrate that the instrument measures SO 2 fluxes with Indonesia), a volcano that has been producing cycles of repeated explosions with periods of minutes to hours for the past several decades. Semeru produces an average of 21-71 tons of SO2 per day, amounting to a yearly output of 8-26 Mt. Using the Semeru data, along with a 1-D transient numerical model of magma ascent, I test the validity of a model in which a viscous plug at the top of the conduit produces cycles of eruption and gas release. I find that it can be a valid hypothesis to explain the observed patterns of degassing at Semeru. Periodic behavior in such a system occurs for a very narrow range of conditions, for which the mass balance between magma flux and open-system gas escape repeatedly

  9. Loss of shutdown cooling during degassing in Doel 1

    International Nuclear Information System (INIS)

    1996-01-01

    The presentation describes loss of shutdown cooling event during degassing in Doel 1 reactor, including description of Doel 1 features,status of plant prior to incident, event sequence and incident causes

  10. A new degassing membrane coupled upflow anaerobic sludge blanket (UASB) reactor to achieve in-situ biogas upgrading and recovery of dissolved CH4 from the anaerobic effluent

    DEFF Research Database (Denmark)

    Luo, Gang; Wang, Wen; Angelidaki, Irini

    2014-01-01

    A new technology for in-situ biogas upgrading and recovery of CH4 from the effluent of biogas reactors was proposed and demonstrated in this study. A vacuum degassing membrane module was used to desorb CO2 from the liquid phase of a biogas reactor. The degassing membrane was submerged...... into a degassing unit (DU). The results from batch experiments showed that mixing intensity, transmembrane pressure, pH and inorganic carbon concentration affected the CO2 desorption rate in the DU. Then, the DU was directly connected to an upflow anaerobic sludge blanket (UASB) reactor. The results showed the CH4...... content was only 51.7% without desorption of CO2, while it increased when the liquid of UASB was recycled through the DU. The CH4 content increased to 71.6%, 90%, and 94% with liquid recirculation rate through the DU of 0.21, 0.42 and 0.63L/h, respectively. The loss of methane due to dissolution...

  11. Metal-Organic Framework-Stabilized CO2/Water Interfacial Route for Photocatalytic CO2 Conversion.

    Science.gov (United States)

    Luo, Tian; Zhang, Jianling; Li, Wei; He, Zhenhong; Sun, Xiaofu; Shi, Jinbiao; Shao, Dan; Zhang, Bingxing; Tan, Xiuniang; Han, Buxing

    2017-11-29

    Here, we propose a CO 2 /water interfacial route for photocatalytic CO 2 conversion by utilizing a metal-organic framework (MOF) as both an emulsifier and a catalyst. The CO 2 reduction occurring at the CO 2 /water interface produces formate with remarkably enhanced efficiency as compared with that in conventional solvent. The route is efficient, facile, adjustable, and environmentally benign, which is applicable for the CO 2 transformation photocatalyzed by different kinds of MOFs.

  12. Fault-controlled CO2 leakage from natural reservoirs in the Colorado Plateau, East-Central Utah

    Science.gov (United States)

    Jung, Na-Hyun; Han, Weon Shik; Watson, Z. T.; Graham, Jack P.; Kim, Kue-Young

    2014-10-01

    The study investigated a natural analogue for soil CO2 fluxes where CO2 has naturally leaked on the Colorado Plateau, East-Central Utah in order to identify various factors that control CO2 leakage and to understand regional-scale CO2 leakage processes in fault systems. The total 332 and 140 measurements of soil CO2 flux were made at 287 and 129 sites in the Little Grand Wash (LGW) and Salt Wash (SW) fault zones, respectively. Measurement sites for CO2 flux involved not only conspicuous CO2 degassing features (e.g., CO2-driven springs/geysers) but also linear features (e.g., joints/fractures and areas of diffusive leakage around a fault damage zone). CO2 flux anomalies were mostly observed along the fault traces. Specifically, CO2 flux anomalies were focused in the northern footwall of the both LGW and SW faults, supporting the existence of north-plunging anticlinal CO2 trap against south-dipping faults as well as higher probability of the north major fault traces as conduits. Anomalous CO2 fluxes also appeared in active travertines adjacent to CO2-driven cold springs and geysers (e.g., 36,259 g m-2 d-1 at Crystal Geyser), ancient travertines (e.g., 5,917 g m-2 d-1), joint zones in sandstone (e.g., 120 g m-2 d-1), and brine discharge zones (e.g., 5,515 g m-2 d-1). These observations indicate that CO2 has escaped through those pathways and that CO2 leakage from these fault zones does not correspond to point source leakage. The magnitude of CO2 flux is progressively reduced from north (i.e. the LGW fault zone, ∼36,259 g m-2 d-1) to south (i.e. the SW fault zone, ∼1,428 g m-2 d-1) despite new inputs of CO2 and CO2-saturated brine to the northerly SW fault from depth. This discrepancy in CO2 flux is most likely resulting from the differences in fault zone architecture and associated permeability structure. CO2-rich fluids from the LGW fault zone may become depleted with respect to CO2 during lateral transport, resulting in an additional decrease in CO2 fluxes

  13. Vapor Discharges On Nevado Del Ruiz During The Recent Activity: Clues On The Composition Of The Deep Hydrothermal System And Its Effects On Thermal Springs

    Science.gov (United States)

    Inguaggiato, S.; Federico, C.; Chacon, Z.; Londono, J. M.; Alzate, D. M.; Gil, E.

    2015-12-01

    The Nevado del ruiz volcano (NdR, 5321m asl), one of the most active in Colombia, threatens about 600,000 people. The existence of an ice cap and several streams channeling in some main rivers increase the risk of lahars and mudflows in case of unrest, as occurred during the November 1985 eruption, which caused 20,000 casualties. The involvement of the local hydrothermal system has also produced in the past phreatic and phreatomagmatic activity, as in 1985 and 1989. After more than 7 years of relative stability, since 2010, the still ongoing phase of unrest has produced two small eruption in 2012, and still maintains in high levels of seismicity and SO2 degassing. In October 2013, a sampling campaign has been performed on thermal springs and streamwater, located at 2600-5000 m asl, analyzed for water chemistry and stable isotopes. By applying a model of steam-heating, based on mass and enthalpy balances, we have estimated the mass rate of steam discharging in the different steam-heated springs. The composition of the hottest thermal spring (Botero Londoño) is probably representative of a marginal part of the hydrothermal system, having a temperature of 250°C and low salinity (Cl ~1500 mg/l), which suggest a chiefly meteoric origin, as also confirmed by the isotope composition retrieved for the hydrothermal water. The vapour discharged at the steam vent "Nereidas" (3600 m asl) is hypothesised to be separated from a high-temperature hyrothermal system. Based on its composition and on literature data on fluid inclusions, we have retrieved the P-T-X conditions of the deep hydrothermal system, as well as its pH and fO2. The vapour feeding Nereidas would separate from a byphasic hydrothermal system characterised by the follow parameters: t= 315°C, P=19 MPa, NaCl= 15 %, CO2 = 9%, and similar proportion between liquid and vapour. Considering also the equilibria involving S-bearing gases and HCl, we obtain pH=2, fO2 fixed by FeO-Fe2O3 buffer, and [Cl]=12000 mg/l. Changes

  14. Advanced technology development reducing CO2 emissions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Sup

    2010-09-15

    Responding to Korean government policies on green growth and global energy/ environmental challenges, SK energy has been developing new technologies to reduce CO2 emissions by 1) CO2 capture and utilization, 2) efficiency improvement, and 3) Li-ion batteries. The paper introduces three advanced technologies developed by SK energy; GreenPol, ACO, and Li-ion battery. Contributing to company vision, a more energy and less CO2, the three technologies are characterized as follows. GreenPol utilizes CO2 as a feedstock for making polymer. Advanced Catalytic Olefin (ACO) reduces CO2 emission by 20% and increase olefin production by 17%. Li-ion Batteries for automotive industries improves CO2 emission.

  15. Argentine hydrothermal panorama

    Energy Technology Data Exchange (ETDEWEB)

    1976-12-01

    An attempt is made to give a realistic review of Argentine thermal waters. The topics discussed are the characteristics of the hydrothermal resources, classification according to their mineral content, hydrothermal flora and fauna, uses of hydrothermal resources, hydrothermal regions of Argentina, and meteorology and climate. A tabulation is presented of the principal thermal waters. (JSR)

  16. Research on Melt Degassing Processes of High Conductivity Hard Drawn Aluminum Wire

    Science.gov (United States)

    Xu, Xuexia; Feng, Yanting; Wang, Qing; Li, Wenbin; Fan, Hui; Wang, Yong; Li, Guowei; Zhang, Daoqian

    2018-03-01

    Degassing effects of ultrasonic and vacuum processes on high conductivity hard drawn aluminum melt were studied. Results showed that the degassing efficiency improved with the increase of ultrasonic power within certain range, stabilizing at 70% with 240W. For vacuum degassing process, hydrogen content of aluminum melt decreased with the loading time and was linear with logarithm of vacuum degree. Comparison of degassing effects of ultrasonic, vacuum, vacuum-ultrasonic degassing process showed that vacuum-ultrasonic process presented optimal effect.

  17. Soil CO2 efflux measurement network by means of closed static chambers to monitor volcanic activity at Tenerife, Canary Islands

    Science.gov (United States)

    Amonte, Cecilia; García-Merino, Marta; Asensio-Ramos, María; Melián, Gladys; García-Hernández, Rubén; Pérez, Aaron; Hernández, Pedro A.; Pérez, Nemesio M.

    2017-04-01

    Tenerife (2304 km2) is the largest of the Canary Islands and has developed a central volcanic complex (Cañadas edifice), that started to grow about 3.5 My ago. Coeval with the construction of the Cañadas edifice, shield basaltic volcanism continued until the present along three rift zones oriented NW-SE, NE-SW and NS (hereinafter referred as NW, NE and NS respectively). Main volcanic historical activity has occurred along de NW and NE rift-zones, although summit cone of Teide volcano, in central volcanic complex, is the only area of the island where surface geothermal manifestations are visible. Uprising of deep-seated gases occurs along the aforementioned volcanic structures causing diffuse emissions at the surface environment of the rift-zones. In the last 20 years, there has been considerable interest in the study of diffuse degassing as a powerful tool in volcano monitoring programs. Diffuse degassing studies are even more important volcanic surveillance tool at those volcanic areas where visible manifestations of volcanic gases are absent. Historically, soil gas and diffuse degassing surveys in volcanic environments have focused mainly on CO2 because it is, after water vapor, the most abundant gas dissolved in magma. One of the most popular methods used to determine CO2 fluxes in soil sciences is based on the absorption of CO2 through an alkaline medium, in its solid or liquid form, followed by gravimetric, conductivity, or titration analyses. In the summer of 2016, a network of 31 closed static chambers was installed, covering the three main structural zones of Tenerife (NE, NW and NS) as well as Cañadas Caldera with volcanic surveillance porpoises. 50 cc of 0.1N KOH solution is placed inside the chamber to absorb the CO2 released from the soil. The solution is replaced weekly and the trapped CO2 is then analyzed at the laboratory by titration. The are expressed as weekly integrated CO2 efflux values. The CO2 efflux values ranged from 3.2 to 12.9 gṡm-2

  18. CO2 Allowance and Electricity Price Interaction

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    With the introduction of CO2 emission constraints on power generators in the European Union, climate policy is starting to have notable effects on energy markets. This paper sheds light on the links between CO2 prices, electricity prices, and electricity costs to industry. It is based on a series of interviews with industrial and electricity stakeholders, as well as a rich literature seeking to estimate the exact effect of CO2 prices on electricity prices.

  19. CO2 sequestration: Storage capacity guideline needed

    Science.gov (United States)

    Frailey, S.M.; Finley, R.J.; Hickman, T.S.

    2006-01-01

    Petroleum reserves are classified for the assessment of available supplies by governmental agencies, management of business processes for achieving exploration and production efficiency, and documentation of the value of reserves and resources in financial statements. Up to the present however, the storage capacity determinations made by some organizations in the initial CO2 resource assessment are incorrect technically. New publications should thus cover differences in mineral adsorption of CO2 and dissolution of CO2 in various brine waters.

  20. Economic effects on taxing CO2 emissions

    International Nuclear Information System (INIS)

    Haaparanta, P.; Jerkkola, J.; Pohjola, J.

    1996-01-01

    The CO 2 emissions can be reduced by using economic instruments, like carbon tax. This project included two specific questions related to CO 2 taxation. First one was the economic effects of increasing CO 2 tax and decreasing other taxes. Second was the economic adjustment costs of reducing net emissions instead of gross emissions. A computable general equilibrium (CGE) model was used in this analysis. The study was taken place in Helsinki School of Economics

  1. Degassing of different magma batches as the main controlling factor for fumarolic fluid chemistry at the Planchón-Peteroa-Azufre Volcanic Complex (Argentina-Chile) in 2010-2015

    Science.gov (United States)

    Tassi, Franco; Aguilera, Felipe; Benavente, Oscar; Paonita, Antonio; Chiodini, Giovanni; Caliro, Stefano; Agusto, Mariano; Gutierrez, Francisco; Capaccioni, Bruno; Vaselli, Orlando; Caselli, Alberto

    2016-04-01

    This study presents the first geochemical data of gas discharges collected during five sampling campaigns (February 2010 to March 2015), from the NNE-oriented Planchón-Peteroa-Azufre Volcanic Complex (PPAVC), located in the Transitional Southern Volcanic Zone (TSVZ) at the border between Argentina and Chile. In 2012, the acidic gas species of the low temperature (up to 102 °C) fumaroles from the Peteroa summit showed a huge increase (SO2>CO2) with respect to the 2010-2011 period, whereas the typical hydrothermal compounds (CH4 and light hydrocarbons) decreased. Such a dramatic compositional change was apparently indicating a pulse of magmatic fluids. By contrast, the temporal evolution of the δ18O-H2O, δD-H2O, R/Ra and 13C-CO2 values suggested an enhanced fluid contribution from a shallow source. In 2014-2015, the dominant hydrothermal signature characterizing the 2010-2011 fumaroles was almost completely restored. The temporary decoupling of the chemical and isotopic parameters can only be reconciled by admitting the occurrence of a double source of magmatic fluids: a basaltic batch, controlling the fumarolic chemistry in 2010-2011 and 2014-2015, and a small, shallower dacitic batch, likely affected by a significant crustal contamination, whose contribution to the fumarolic fluid emissions achieved its maximum in 2012. It cannot be ruled out that the phreatic to phreatomagmatic eruptions (VEI ≤2) that have affected Peteroa volcano from January 2010 to July 2011 have played a significant role for the modification of the deep feeding source of the fumarolic gases. The disturbance created by the volcanic events and the related seismic activity (MW<3), possibly related to the devastating Maule earthquake occurred on February 27 2010, could have activated a silent dacitic magma batch that in 2012 imposed over that of basaltic composition. Although this scenario provides a reliable explanation for the peculiar compositional changes that affected the Peteroa

  2. Assessment of CO2 discharge in a spring using time-variant stable carbon isotope data as a natural analogue study of CO2 leakage

    Science.gov (United States)

    Yu, Soonyoung; Chae, Gitak; Jo, Minki; Kim, Jeong-Chan; Yun, Seong-Taek

    2015-04-01

    CO2-rich springs have been studied as a natural analogue of CO2 leakage through shallow subsurface environment, as they provide information on the behaviors of CO2 during the leakage from geologic CO2 storage sites. For this study, we monitored the δ13C values as well as temperature, pH, EC, DO, and alkalinity for a CO2-rich spring for 48 hours. The water samples (N=47) were collected every hour in stopper bottles without headspace to avoid the interaction with air and the CO2 degassing. The δ13C values of total dissolved inorganic carbon (TDIC) in the water samples were analyzed using a cavity ring-down spectroscopy (CRDS) system (Picarro). The values of δ13CTDIC, temperature, pH, EC, DO, and alkalinity were in the range of -9.43 ~ -8.91 o 12.3 ~ 13.2oC, 4.86 ~ 5.02, 186 ~ 189 μS/cm, 1.8 ~ 3.4 mg/L, and 0.74 ~ 0.95 meq/L, respectively. The concentrations of TDIC calculated using pH and alkalinity values were between 22.5 and 34.8 mmol/L. The δ13CTDIC data imply that dissolved carbon in the spring was derived from a deep-seated source (i.e., magmatic) that was slightly intermixed with soil CO2. Careful examination of the time-series variation of measured parameters shows the following characteristics: 1) the δ13CTDIC values are negatively correlated with pH (r = -0.59) and positively correlated with TDIC (r = 0.58), and 2) delay times of the change of pH and alkalinity following the change of δ13CTDIC values are 0 and -3 hours, respectively; the pH change occurs simultaneously with the change of δ13CTDIC, while the alkalinity change happens before 3 hours. Our results indicate that the studied CO2-rich spring is influenced by the intermittent supply of deep-seated CO2. [Acknowledgment] This work was financially supported by the fundamental research project of KIGAM and partially by the "Geo-Advanced Innovative Action (GAIA) Project (2014000530003)" from Korea Ministry of Environment (MOE).

  3. Experimental Ion Mobility measurements in Ne-CO$_2$ and CO$_2$-N$_2$ mixtures

    CERN Document Server

    Encarnação, P.M.C.C.; Veenhof, R.; Neves, P.N.B.; Santos, F.P.; Trindade, A.M.F.; Borges, F.I.G.M.; Conde, C.A.N.

    2016-01-01

    In this paper we present the experimental results for the mobility, K0, of ions in neon-carbon dioxide (Ne-CO2) and carbon dioxide-nitrogen (CO2-N2) gaseous mixtures for total pressures ranging from 8–12 Torr, reduced electric fields in the 10–25 Td range, at room temperature. Regarding the Ne-CO2 mixture only one peak was observed for CO2 concentrations above 25%, which has been identified as an ion originated in CO2, while below 25% of CO2 a second-small peak appears at the left side of the main peak, which has been attributed to impurities. The mobility values for the main peak range between 3.51 ± 0.05 and 1.07 ± 0.01 cm2V−1s−1 in the 10%-99% interval of CO2, and from 4.61 ± 0.19 to 3.00 ± 0.09 cm2V−1s−1 for the second peak observed (10%–25% of CO2). For the CO2-N2, the time-of-arrival spectra displayed only one peak for CO2 concentrations above 10%, which was attributed to ions originated in CO2, namely CO2+(CO2), with a second peak appearing for CO2 concentrations below 10%. This secon...

  4. Supercritical CO2 uptake by nonswelling phyllosilicates.

    Science.gov (United States)

    Wan, Jiamin; Tokunaga, Tetsu K; Ashby, Paul D; Kim, Yongman; Voltolini, Marco; Gilbert, Benjamin; DePaolo, Donald J

    2018-01-30

    Interactions between supercritical (sc) CO 2 and minerals are important when CO 2 is injected into geologic formations for storage and as working fluids for enhanced oil recovery, hydraulic fracturing, and geothermal energy extraction. It has previously been shown that at the elevated pressures and temperatures of the deep subsurface, scCO 2 alters smectites (typical swelling phyllosilicates). However, less is known about the effects of scCO 2 on nonswelling phyllosilicates (illite and muscovite), despite the fact that the latter are the dominant clay minerals in deep subsurface shales and mudstones. Our studies conducted by using single crystals, combining reaction (incubation with scCO 2 ), visualization [atomic force microscopy (AFM)], and quantifications (AFM, X-ray photoelectron spectroscopy, X-ray diffraction, and off-gassing measurements) revealed unexpectedly high CO 2 uptake that far exceeded its macroscopic surface area. Results from different methods collectively suggest that CO 2 partially entered the muscovite interlayers, although the pathways remain to be determined. We hypothesize that preferential dissolution at weaker surface defects and frayed edges allows CO 2 to enter the interlayers under elevated pressure and temperature, rather than by diffusing solely from edges deeply into interlayers. This unexpected uptake of CO 2 , can increase CO 2 storage capacity by up to ∼30% relative to the capacity associated with residual trapping in a 0.2-porosity sandstone reservoir containing up to 18 mass % of illite/muscovite. This excess CO 2 uptake constitutes a previously unrecognized potential trapping mechanism. Copyright © 2018 the Author(s). Published by PNAS.

  5. Hierarchical CuCo2O4 nanobelts as a supercapacitor electrode with high areal and specific capacitance

    International Nuclear Information System (INIS)

    Vijayakumar, Subbukalai; Lee, Seong-Hun; Ryu, Kwang-Sun

    2015-01-01

    Highlights: • First time we report the synthesis of CuCo 2 O 4 nanobelts using hydrothermal method. • The spinel CuCo 2 O 4 nanobelts exhibit maximum areal capacitance of 2.42 F cm −2 . • After 1800 cycles, 127% of the initial specific capacitance was retained. - Abstract: One dimensional hierarchical CuCo 2 O 4 nanobelt like architecture was synthesized via hydrothermal method. The synthesized nanomaterial was characterized using X-ray diffraction (XRD) analysis, field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The TEM image clearly shows the nanobelt like architecture of CuCo 2 O 4 . The supercapacitor properties of CuCo 2 O 4 nanobelts electrode were tested using cyclic voltammetry, charge-discharge and electrochemical impedance spectroscopy. The spinel CuCo 2 O 4 nanobelts exhibit maximum areal and specific capacitance of 2.42 F cm −2 (809 F g −1 ). After 1800 continuous charge-discharge cycles, 127% of the initial capacitance was retained. This superior electrochemical supercapacitor property is mainly due to increased surface area and ion transport of nanobelt like architecture. The charge transfer resistance (R ct ) value of CuCo 2 O 4 nanobelt electrode is 3.85 Ω. This high capacitance and cyclic stability demonstrate that the prepared CuCo 2 O 4 nanobelts are a promising candidate for supercapacitors.

  6. NiCo2S4 nanorod embedded rGO sheets as electrodes for supercapacitor

    Science.gov (United States)

    Sarkar, Aatreyee; Bera, Supriya; Chakraborty, Amit Kumar

    2018-04-01

    We report the synthesis of a hybrid nanostructure based on NiCo2S4 and reduced graphene oxide (rGO) following a facile hydrothermal method. X-ray diffraction (XRD), and electron microscopy (FESEM and HRTEM) analyses showed rod-like NiCo2S4 nanostructures embedded in rGO sheets. The electrochemical analysis of the synthesized nanohybrid using cyclic voltammetry (CV) and galvanostatic charge discharge (GCD) revealed specific capacitance of 410 F/gm indicating its suitability as a good electrode material for supercapacitor.

  7. Highly CO2-supersaturated melts in the Pannonian lithospheric mantle - A transient carbon reservoir?

    Science.gov (United States)

    Créon, Laura; Rouchon, Virgile; Youssef, Souhail; Rosenberg, Elisabeth; Delpech, Guillaume; Szabó, Csaba; Remusat, Laurent; Mostefaoui, Smail; Asimow, Paul D.; Antoshechkina, Paula M.; Ghiorso, Mark S.; Boller, Elodie; Guyot, François

    2017-08-01

    Subduction of carbonated crust is widely believed to generate a flux of carbon into the base of the continental lithospheric mantle, which in turn is the likely source of widespread volcanic and non-volcanic CO2 degassing in active tectonic intracontinental settings such as rifts, continental margin arcs and back-arc domains. However, the magnitude of the carbon flux through the lithosphere and the budget of stored carbon held within the lithospheric reservoir are both poorly known. We provide new constraints on the CO2 budget of the lithospheric mantle below the Pannonian Basin (Central Europe) through the study of a suite of xenoliths from the Bakony-Balaton Highland Volcanic Field. Trails of secondary fluid inclusions, silicate melt inclusions, networks of melt veins, and melt pockets with large and abundant vesicles provide numerous lines of evidence that mantle metasomatism affected the lithosphere beneath this region. We obtain a quantitative estimate of the CO2 budget of the mantle below the Pannonian Basin using a combination of innovative analytical and modeling approaches: (1) synchrotron X-ray microtomography, (2) NanoSIMS, Raman spectroscopy and microthermometry, and (3) thermodynamic models (Rhyolite-MELTS). The three-dimensional volumes reconstructed from synchrotron X-ray microtomography allow us to quantify the proportions of all petrographic phases in the samples and to visualize their textural relationships. The concentration of CO2 in glass veins and pockets ranges from 0.27 to 0.96 wt.%, higher than in typical arc magmas (0-0.25 wt.% CO2), whereas the H2O concentration ranges from 0.54 to 4.25 wt.%, on the low end for estimated primitive arc magmas (1.9-6.3 wt.% H2O). Trapping pressures for vesicles were determined by comparing CO2 concentrations in glass to CO2 saturation as a function of pressure in silicate melts, suggesting pressures between 0.69 to 1.78 GPa. These values are generally higher than trapping pressures for fluid inclusions

  8. Emission of SO2, CO2, and H2S from Augustine Volcano, 2002-2008: Chapter 26 in The 2006 eruption of Augustine Volcano, Alaska

    Science.gov (United States)

    McGee, Kenneth A.; Doukas, Michael P.; McGimsey, Robert G.; Neal, Christina A.; Wessels, Rick L.; Power, John A.; Coombs, Michelle L.; Freymueller, Jeffrey T.

    2010-01-01

    Airborne surveillance of gas emissions from Augustine Volcano and other Cook Inlet volcanoes began in 1990 to identify baseline emission levels during noneruptive conditions. Gas measurements at Augustine for SO2, CO2, and H2S showed essentially no evidence of anomalous degassing through spring 2005. Neither did a measurement on May 10, 2005, right after the onset of low level seismicity and inflation. The following measurement, on December 20, 2005, showed Augustine to be degassing about 600 metric tons per day (t/d) of SO2, and by January 4, 2006, only 7 days before the first explosive event, SO2 emissions had climbed to ten times that amount. Maximum emission rates measured during the subsequent eruption were: 8,930 t/d SO2 (February 24, 2006), 1,800 t/d CO2 (March 9, 2006), and 4.3 t/d H2S (January 19, 2006). In total, 45 measurements for SO2 were made from December 2005 through the end of 2008, with 19 each for CO2 and H2S during the same period. Molar CO2/SO2 ratios averaged about 1.6. In general, SO2 emissions appeared to increase during inflation of the volcanic edifice, whereas CO2 emissions were at their highest during the period of deflation associated with the vigorous effusive phase of the eruption in March. High SO2 was probably associated with degassing of shallow magma, whereas high CO2 likely reflected deep (>4 km) magma recharge of the sub-volcanic plumbing system, For the 2005–6 period, the volcano released a total of about 1.5×106 tons of CO2 to the atmosphere, a level similar to the annual output of a medium-sized natural-gas-fired powerplant. Augustine also emitted about 8×105 tons of SO2, similar to that produced by the 1976 and 1986 eruptions of the volcano.

  9. Corn residue removal and CO2 emissions

    Science.gov (United States)

    Carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) are the primary greenhouse gases (GHG) emitted from the soil due to agricultural activities. In the short-term, increases in CO2 emissions indicate increased soil microbial activity. Soil micro-organisms decompose crop residues and release...

  10. Increasing CO2 storage in oil recovery

    International Nuclear Information System (INIS)

    Jessen, K.; Kovscek, A.R.; Orr, F.M. Jr.

    2005-01-01

    Oil fields offer a significant potential for storing CO 2 and will most likely be the first large scale geological targets for sequestration as the infrastructure, experience and permitting procedures already exist. The problem of co-optimizing oil production and CO 2 storage differs significantly from current gas injection practice due to the cost-benefit imbalance resulting from buying CO 2 for enhanced oil recovery projects. Consequently, operators aim to minimize the amount of CO 2 required to sweep an oil reservoir. For sequestration purposes, where high availability of low cost CO 2 is assumed, the design parameters of enhanced oil recovery processes must be re-defined to optimize the amount of CO 2 left in the reservoir at the time of abandonment. To redefine properly the design parameters, thorough insight into the mechanisms controlling the pore scale displacement efficiency and the overall sweep efficiency is essential. We demonstrate by calculation examples the different mechanisms controlling the displacement behavior of CO 2 sequestration schemes, the interaction between flow and phase equilibrium and how proper design of the injection gas composition and well completion are required to co-optimize oil production and CO 2 storage. [Author

  11. NIST Photoionization of CO2 (ARPES) Database

    Science.gov (United States)

    SRD 119 NIST Photoionization of CO2 (ARPES) Database (Web, free access)   CO2 is studied using dispersed synchrotron radiation in the 650 Å to 850 Å spectral region. The vibrationally resolved photoelectron spectra are analyzed to generate relative vibrational transition amplitudes and the angular asymmetry parameters describing the various transitions observed.

  12. CO2 Capture with Enzyme Synthetic Analogue

    Energy Technology Data Exchange (ETDEWEB)

    Cordatos, Harry

    2010-11-08

    Overview of an ongoing, 2 year research project partially funded by APRA-E to create a novel, synthetic analogue of carbonic anhydrase and incorporate it into a membrane for removal of CO2 from flue gas in coal power plants. Mechanism background, preliminary feasibility study results, molecular modeling of analogue-CO2 interaction, and program timeline are provided.

  13. Eindhoven Airport : towards zero CO2 emissions

    NARCIS (Netherlands)

    Jorge Simoes Pedro, Joana

    2015-01-01

    Eindhoven airport is growing and it is strongly committed to take this opportunity to invest in innovative solutions for a sustainable development. Therefore, this document proposes a strategic plan for reaching Zero CO2 emissions at Eindhoven airport. This document proposes to reduce the CO2

  14. Thermodynamic modeling of CO2 mixtures

    DEFF Research Database (Denmark)

    Bjørner, Martin Gamel

    Knowledge of the thermodynamic properties and phase equilibria of mixtures containing carbon dioxide (CO2) is important in several industrial processes such as enhanced oil recovery, carbon capture and storage, and supercritical extractions, where CO2 is used as a solvent. Despite this importance...

  15. Increasing CO2 storage in oil recovery

    International Nuclear Information System (INIS)

    Jessen, Kristian; Kovscek, Anthony R.; Orr, Franklin M.

    2005-01-01

    Oil fields offer a significant potential for storing CO 2 and will most likely be the first large scale geological targets for sequestration as the infrastructure, experience and permitting procedures already exist. The problem of co-optimizing oil production and CO 2 storage differs significantly from current gas injection practice due to the cost-benefit imbalance resulting from buying CO 2 for enhanced oil recovery projects. Consequently, operators aim to minimize the amount of CO 2 required to sweep an oil reservoir. For sequestration purposes, where high availability of low cost CO 2 is assumed, the design parameters of enhanced oil recovery processes must be re-defined to optimize the amount of CO 2 left in the reservoir at the time of abandonment. To redefine properly the design parameters, thorough insight into the mechanisms controlling the pore scale displacement efficiency and the overall sweep efficiency is essential. We demonstrate by calculation examples the different mechanisms controlling the displacement behavior of CO 2 sequestration schemes, the interaction between flow and phase equilibrium and how proper design of the injection gas composition and well completion are required to co-optimize oil production and CO 2 storage

  16. CO2 emission calculations and trends

    International Nuclear Information System (INIS)

    Boden, T.A.; Marland, G.; Andres, R.J.

    1995-01-01

    Evidence that the atmospheric CO 2 concentration has risen during the past several decades is irrefutable. Most of the observed increase in atmospheric CO 2 is believed to result from CO 2 releases from fossil-fuel burning. The United Nations (UN) Framework Convention on Climate Change (FCCC), signed in Rio de Janeiro in June 1992, reflects global concern over the increasing CO 2 concentration and its potential impact on climate. One of the convention's stated objectives was the ''stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. '' Specifically, the FCCC asked all 154 signing countries to conduct an inventory of their current greenhouse gas emissions, and it set nonbinding targets for some countries to control emissions by stabilizing them at 1990 levels by the year 2000. Given the importance of CO 2 as a greenhouse gas, the relationship between CO 2 emissions and increases in atmospheric CO 2 levels, and the potential impacts of a greenhouse gas-induced climate change; it is important that comprehensive CO 2 emissions records be compiled, maintained, updated, and documented

  17. Recent development of capture of CO2

    CERN Document Server

    Chavez, Rosa Hilda

    2014-01-01

    "Recent Technologies in the capture of CO2" provides a comprehensive summary on the latest technologies available to minimize the emission of CO2 from large point sources like fossil-fuel power plants or industrial facilities. This ebook also covers various techniques that could be developed to reduce the amount of CO2 released into the atmosphere. The contents of this book include chapters on oxy-fuel combustion in fluidized beds, gas separation membrane used in post-combustion capture, minimizing energy consumption in CO2 capture processes through process integration, characterization and application of structured packing for CO2 capture, calcium looping technology for CO2 capture and many more. Recent Technologies in capture of CO2 is a valuable resource for graduate students, process engineers and administrative staff looking for real-case analysis of pilot plants. This eBook brings together the research results and professional experiences of the most renowned work groups in the CO2 capture field...

  18. Flow assurance studies for CO2 transport

    NARCIS (Netherlands)

    Veltin, J.; Belfroid, S.P.C.

    2013-01-01

    In order to compensate for the relative lack of experience of the CCTS community, Flow Assurance studies of new CO2 pipelines and networks are a very important step toward reliable operation. This report details a typical approach for Flow Assurance study of CO2 transport pipeline. Considerations to

  19. Joint interpretation of geoelectrical and soil-gas measurements for monitoring CO2 releases at a natural analogue

    DEFF Research Database (Denmark)

    Sauer, U.; Watanabe, N.; Singh, Ashok

    2014-01-01

    the complex behaviour of temporal variations for the flow patterns. In particular, coupled migration of gas and water plays an important influencing role in this process. Site-specific, near surface geological features and meteorological conditions seem to exert great influence on the degassing pattern...... and flux measurements, self-potential (SP) and geoelectrical surveys) showed that the combination of geophysical methods with soil-gas analysis for mesoscale monitoring of the shallow subsurface above geologic CO2 storages can be a valuable tool for mapping and monitoring potential CO2 spread...... in the subsurface. Three measurement campaigns were undertaken - May 2011, July 2011 and April 2012 - at an analogue site in the Cheb Basin, Czech Republic, with the aim of studying CO2 leakages and their temporal and spatial behaviour. Results of geoelectrical investigations give an insight into the structural...

  20. Disclosing Multiple Magma Degassing Sources Offers Unique Insights of What's Behind the Campi Flegrei Caldera Unrest

    Science.gov (United States)

    Moretti, R.; Civetta, L.; Orsi, G.; Arienzo, I.; D'Antonio, M.; Di Renzo, V.

    2013-12-01

    The definition of the structure and evolution of the magmatic system of Campi Flegrei caldera (CFc), Southern Italy, has been a fundamental tool for the assessment of the short-term volcanic hazard. The ensemble of geophysical and petrologic data show that the CFc magmatic system has been -and still is- characterized by two major reservoirs at different depths. From the deep one (around 8 km), less evolved magmas crystallize and degas, supplying fluids and magmas to the shallow (3-4 km) reservoirs. A thorough reconstruction of processes occurring in magma chamber/s prior and/or during the CFc eruptions has shown that magmas entering shallow reservoirs mixed with resident and crystallized batches. Also the 1982-85 unrest episode has been related to a magma intrusion of 2.1 x 10^7 m^3 at 3-4 km depth, on the basis of geophysical data (ground deformation, gravimetry, seismic imaging) and their interpretation. Thermodynamic evaluation of magma properties, at the time of emplacement, suggests for such an intrusion a bulk density of 2.000 kg/m^3 . Such a value testifies the high amount of exsolved volatiles within the system. The available record of geochemical and isotopic data on surface fumaroles, coupled with melt inclusion data, has already shown that dual (deep and shallow) magma degassing from such two reservoirs, as well as their interaction with the hydrothermal system, allows explaining the relevant fluctuations observed at crater fumaroles after the 1982-85 magma intrusion. An important role was played by the rapid crystallization (around 30 years) of the shallow magma, such that in the recent years gas discharges should be fuelled mostly by the deep magma. Such a process is well recorded in the fumarolic gas composition of the last ~10 years, but has to be reconciled with the unrest dynamics which took place after year 2000, characterized by a slow but continuous ground uplift. All geochemical indicators (major species and noble gases) point to three possible

  1. Level of carbon dioxide diffuse degassing from the ground of Vesuvio: comparison between extensive surveys and inferences on the gas source

    Directory of Open Access Journals (Sweden)

    Domenico Granieri

    2013-11-01

    Full Text Available An extensive campaign of diffuse CO2 soil flux was carried out at the cone of Vesuvio in October 2006 with two main objectives: 1 to provide an estimation of CO2 diffusely discharged through the soils in the summit area and 2 to evidence those sectors of the volcano where structural and morphological conditions could favour the gas output. The survey consisted of 502 measurements of soil CO2 flux homogenously distributed over an area of about 1.8 km2. Results of this survey were compared with those obtained during a similar campaign carried out by Frondini et al. in 2000, from which we have taken and reinterpreted a subset of data belonging to the common investigated area. Graphical statistical analysis showed three overlapping populations in both surveys, evidencing the contribution of three different sources feeding the soil CO2 degassing process. The overall CO2 emission pattern of 2006 is coherent with that observed in 2000 and suggests that a value between 120 and 140 t/day of CO2 is representative of the total CO2 discharged by diffuse degassing from the summit area of Vesuvio. The preferential exhaling area lies in the inner crater, whose contribution resulted in 45.3% of the total CO2 emission in 2006 (with 62.8 t/day and in 57.4% (with 70.3 t/day in 2000, although its extension is only 13% of the investigated area. This highly emissive area correlated closely with the structural discontinuities of Vesuvio cone, mainly suggesting that the NW-SE trending tectonic line is actually an active fault leaking deep gas to the bottom of the crater. The drainage action of the fault could be enhanced by the “aspiration” effect of the volcanic conduit.

  2. Novel ZIF-300 Mixed-Matrix Membranes for Efficient CO2 Capture.

    Science.gov (United States)

    Yuan, Jianwei; Zhu, Haipeng; Sun, Jiajia; Mao, Yangyang; Liu, Gongping; Jin, Wanqin

    2017-11-08

    Because of the high separation performance and easy preparation, mixed-matrix membranes (MMMs) consisting of metal-organic frameworks have received much attention. In this article, we report a novel ZIF-300/PEBA MMM consisting of zeolite imidazolate framework (ZIF-300) crystals and polyether block amide (PEBA) matrix. The ZIF-300 crystal size was effectively reduced by optimizing the hydrothermal reaction condition from ∼15 to ∼1 μm. The morphology and physicochemical and sorption properties of the synthesized ZIF-300 crystals and as-prepared ZIF-300/PEBA MMMs were systematically studied. The results showed that ZIF-300 crystals with a size of ∼1 μm maintained excellent preferential CO 2 sorption over N 2 without degradation of the crystal structure in the MMMs. As a result, uniformly incorporated ZIF-300 crystals highly enhanced both the CO 2 permeability and the CO 2 /N 2 selectivity of pure PEBA membrane. The optimized ZIF-300-PEBA MMMs with a ZIF-300 loading of 30 wt % exhibited a high and stable CO 2 permeability of 83 Barrer and CO 2 /N 2 selectivity of 84, which are 59.2% and 53.5% higher than pure PEBA membrane, respectively. The obtained performance surpassed the upper bound of state-of-the-art membranes for CO 2 /N 2 separation. This work demonstrated that the proposed ZIF-300/PEBA MMM could be a potential candidate for an efficient CO 2 capture process.

  3. Heat flux from magmatic hydrothermal systems related to availability of fluid recharge

    Science.gov (United States)

    Harvey, M. C.; Rowland, J.V.; Chiodini, G.; Rissmann, C.F.; Bloomberg, S.; Hernandez, P.A.; Mazot, A.; Viveiros, F.; Werner, Cynthia A.

    2015-01-01

    Magmatic hydrothermal systems are of increasing interest as a renewable energy source. Surface heat flux indicates system resource potential, and can be inferred from soil CO2 flux measurements and fumarole gas chemistry. Here we compile and reanalyze results from previous CO2 flux surveys worldwide to compare heat flux from a variety of magma-hydrothermal areas. We infer that availability of water to recharge magmatic hydrothermal systems is correlated with heat flux. Recharge availability is in turn governed by permeability, structure, lithology, rainfall, topography, and perhaps unsurprisingly, proximity to a large supply of water such as the ocean. The relationship between recharge and heat flux interpreted by this study is consistent with recent numerical modeling that relates hydrothermal system heat output to rainfall catchment area. This result highlights the importance of recharge as a consideration when evaluating hydrothermal systems for electricity generation, and the utility of CO2 flux as a resource evaluation tool.

  4. Silvering substrates after CO2 snow cleaning

    Science.gov (United States)

    Zito, Richard R.

    2005-09-01

    There have been some questions in the astronomical community concerning the quality of silver coatings deposited on substrates that have been cleaned with carbon dioxide snow. These questions center around the possible existence of carbonate ions left behind on the substrate by CO2. Such carbonate ions could react with deposited silver to produce insoluble silver carbonate, thereby reducing film adhesion and reflectivity. Carbonate ions could be produced from CO2 via the following mechanism. First, during CO2 snow cleaning, a small amount of moisture can condense on a surface. This is especially true if the jet of CO2 is allowed to dwell on one spot. CO2 gas can dissolve in this moisture, producing carbonic acid, which can undergo two acid dissociations to form carbonate ions. In reality, it is highly unlikely that charged carbonate ions will remain stable on a substrate for very long. As condensed water evaporates, Le Chatelier's principle will shift the equilibrium of the chain of reactions that produced carbonate back to CO2 gas. Furthermore, the hydration of CO2 reaction of CO2 with H20) is an extremely slow process, and the total dehydrogenation of carbonic acid is not favored. Living tissues that must carry out the equilibration of carbonic acid and CO2 use the enzyme carbonic anhydrase to speed up the reaction by a factor of one million. But no such enzymatic action is present on a clean mirror substrate. In short, the worst case analysis presented below shows that the ratio of silver atoms to carbonate radicals must be at least 500 million to one. The results of chemical tests presented here support this view. Furthermore, film lift-off tests, also presented in this report, show that silver film adhesion to fused silica substrates is actually enhanced by CO2 snow cleaning.

  5. The ins and outs of CO2

    Science.gov (United States)

    Raven, John A.; Beardall, John

    2016-01-01

    It is difficult to distinguish influx and efflux of inorganic C in photosynthesizing tissues; this article examines what is known and where there are gaps in knowledge. Irreversible decarboxylases produce CO2, and CO2 is the substrate/product of enzymes that act as carboxylases and decarboxylases. Some irreversible carboxylases use CO2; others use HCO3 –. The relative role of permeation through the lipid bilayer versus movement through CO2-selective membrane proteins in the downhill, non-energized, movement of CO2 is not clear. Passive permeation explains most CO2 entry, including terrestrial and aquatic organisms with C3 physiology and biochemistry, terrestrial C4 plants and all crassulacean acid metabolism (CAM) plants, as well as being part of some mechanisms of HCO3 – use in CO2 concentrating mechanism (CCM) function, although further work is needed to test the mechanism in some cases. However, there is some evidence of active CO2 influx at the plasmalemma of algae. HCO3 – active influx at the plasmalemma underlies all cyanobacterial and some algal CCMs. HCO3 – can also enter some algal chloroplasts, probably as part of a CCM. The high intracellular CO2 and HCO3 – pools consequent upon CCMs result in leakage involving CO2, and occasionally HCO3 –. Leakage from cyanobacterial and microalgal CCMs involves up to half, but sometimes more, of the gross inorganic C entering in the CCM; leakage from terrestrial C4 plants is lower in most environments. Little is known of leakage from other organisms with CCMs, though given the leakage better-examined organisms, leakage occurs and increases the energetic cost of net carbon assimilation. PMID:26466660

  6. Seasonal variation of air-sea CO2 fluxes in the Terra Nova Bay of the Ross Sea, Antarctica, based on year-round pCO2 observations

    Science.gov (United States)

    Zappa, C. J.; Rhee, T. S.; Kwon, Y. S.; Choi, T.; Yang, E. J.; Kim, J.

    2017-12-01

    The polar oceans are rapidly changing in response to climate variability. In particular, augmented inflow of glacial melt water and shrinking sea-ice extent impacts the polar coastal oceans, which may in turn shift the biogeochemistry into an unprecedented paradigm not experienced previously. Nonetheless, most research in the polar oceans is limited to the summer season. Here, we present the first direct observations of ocean and atmospheric pCO2 measured near the coast of Terra Nova Bay in the Ross Sea, Antarctica, ongoing since February, 2015 at Jang Bogo Station. The coastal area is covered by landfast sea-ice from spring to fall while continually exposed to the atmosphere during summer season only. The pCO2 in seawater swung from 120 matm in February to 425 matm in early October. Although sea-ice still covers the coastal area, pCO2 already started decreasing after reaching the peak in October. In November, the pCO2 suddenly dropped as much as 100 matm in a week. This decrease of pCO2 continued until late February when the sea-ice concentration was minimal. With growing sea ice, the pCO2 increased logarithmically reaching the atmospheric concentration in June/July, depending on the year, and continued to increase until October. Daily mean air-sea CO2 flux in the coastal area widely varied from -70 mmol m-2 d-1 to 20 mmol m-2 d-1. Based on these observations of pCO2 in Terra Nova Bay, the annual uptake of CO2 is 8 g C m-2, estimated using the fraction of sea-ice concentration estimated from AMSR2 microwave emission imagery. Extrapolating to all polynyas surrounding Antarctica, we expect the annual uptake of 8 Tg C in the atmosphere. This is comparable to the amount of CO2 degassed into the atmosphere south of the Antarctic Polar Front (62°S).

  7. Carbon monoxide degassing from seismic fault zones in the Basin and Range province, west of Beijing, China

    Science.gov (United States)

    Sun, Yutao; Zhou, Xiaocheng; Zheng, Guodong; Li, Jing; Shi, Hongyu; Guo, Zhengfu; Du, Jianguo

    2017-11-01

    Degassing of carbon monoxide (CO), which plays a significant role in the contribution of deep carbon to the atmosphere, commonly occurs within active fault zones. CO degassing from soil to the atmosphere in the Basin and Range province, west of Beijing (BRPB), China, was investigated by in-situ field measurements in the active fault zones. The measured concentrations of CO in soil gas in the BRPB ranged from 0.29 × 10-6 to 1.1 × 10-6 with a mean value of 0.6 × 10-6, which is approximately twice as large as that in the atmosphere. Net fluxes of CO degassing ranged from -48.6 mg m-2 d-1 to 12.03 mg m-2 d-1. The diffusion of CO from soil to the atmosphere in the BRPB was estimated to be at least 7.6 × 103 ton/a, which is comparable to the corresponding result of about 1.2 × 104 ton/a for CO2. CO concentrations were spatially heterogeneous with clearly higher concentrations along the NE-SW trending in the BRPB. These elevated values of CO concentrations were also coincident with the region with low-velocity and high conductivity in deep mantle, and high Poisson's ratio in the crust, thereby suggesting that CO degassing from the soil might be linked to upwelling of the asthenospheric mantle. Other sources of CO in the soil gas are suggested to be dominated by chemical reactions between deep fluids and carbonate minerals (e.g., dolomite, limestone, and siderite) in country rocks. Biogenic processes may also contribute to the CO in soil gas. The spatial distribution patterns of CO concentrations are coincident with the stress field, suggesting that the concentrations of CO could be a potential indicator for crustal stress field and, hence is potential useful for earthquake monitoring in the BRPB.

  8. A new degassing membrane coupled upflow anaerobic sludge blanket (UASB) reactor to achieve in-situ biogas upgrading and recovery of dissolved CH4 from the anaerobic effluent

    International Nuclear Information System (INIS)

    Luo, Gang; Wang, Wen; Angelidaki, Irini

    2014-01-01

    Highlights: • A new UASB configuration was developed by coupling with degassing membrane. • In-situ biogas upgrading was achieved with high methane content (>90%). • Decrease of dissolved methane in the anaerobic effluent was achieved. - Abstract: A new technology for in-situ biogas upgrading and recovery of CH 4 from the effluent of biogas reactors was proposed and demonstrated in this study. A vacuum degassing membrane module was used to desorb CO 2 from the liquid phase of a biogas reactor. The degassing membrane was submerged into a degassing unit (DU). The results from batch experiments showed that mixing intensity, transmembrane pressure, pH and inorganic carbon concentration affected the CO 2 desorption rate in the DU. Then, the DU was directly connected to an upflow anaerobic sludge blanket (UASB) reactor. The results showed the CH 4 content was only 51.7% without desorption of CO 2 , while it increased when the liquid of UASB was recycled through the DU. The CH 4 content increased to 71.6%, 90%, and 94% with liquid recirculation rate through the DU of 0.21, 0.42 and 0.63 L/h, respectively. The loss of methane due to dissolution in the effluent was reduced by directly pumping the reactor effluent through the DU. In this way, the dissolved CH 4 concentration in the effluent decreased from higher than 0.94 mM to around 0.13 mM, and thus efficient recovery of CH 4 from the anaerobic effluent was achieved. In the whole operational period, the COD removal efficiency and CH 4 yield were not obviously affected by the gas desorption

  9. Hydrothermal processing of radioactive combustible waste

    International Nuclear Information System (INIS)

    Worl, L.A.; Buelow, S.J.; Harradine, D.; Le, L.; Padilla, D.D.; Roberts, J.H.

    1998-01-01

    Hydrothermal processing has been demonstrated for the treatment of radioactive combustible materials for the US Department of Energy. A hydrothermal processing system was designed, built and tested for operation in a plutonium glovebox. Presented here are results from the study of the hydrothermal oxidation of plutonium and americium contaminated organic wastes. Experiments show the destruction of the organic component to CO 2 and H 2 O, with 30 wt.% H 2 O 2 as an oxidant, at 540 C and 46.2 MPa. The majority of the actinide component forms insoluble products that are easily separated by filtration. A titanium liner in the reactor and heat exchanger provide corrosion resistance for the oxidation of chlorinated organics. The treatment of solid material is accomplished by particle size reduction and the addition of a viscosity enhancing agent to generate a homogeneous pumpable mixture

  10. Recycling CO 2 ? Computational Considerations of the Activation of CO 2 with Homogeneous Transition Metal Catalysts

    KAUST Repository

    Drees, Markus; Cokoja, Mirza; Kü hn, Fritz E.

    2012-01-01

    . A similar approach, storing energy from renewable sources in chemical bonds with CO 2 as starting material, may lead to partial recycling of CO 2 created by human industrial activities. Unfortunately, currently available routes for the transformation

  11. Carbonation and CO2 uptake of concrete

    International Nuclear Information System (INIS)

    Yang, Keun-Hyeok; Seo, Eun-A; Tae, Sung-Ho

    2014-01-01

    This study developed a reliable procedure to assess the carbon dioxide (CO 2 ) uptake of concrete by carbonation during the service life of a structure and by the recycling of concrete after demolition. To generalize the amount of absorbable CO 2 per unit volume of concrete, the molar concentration of carbonatable constituents in hardened cement paste was simplified as a function of the unit content of cement, and the degree of hydration of the cement paste was formulated as a function of the water-to-cement ratio. The contribution of the relative humidity, type of finishing material for the concrete surface, and the substitution level of supplementary cementitious materials to the CO 2 diffusion coefficient in concrete was reflected using various correction factors. The following parameters varying with the recycling scenario were also considered: the carbonatable surface area of concrete crusher-runs and underground phenomena of the decreased CO 2 diffusion coefficient and increased CO 2 concentration. Based on the developed procedure, a case study was conducted for an apartment building with a principal wall system and an office building with a Rahmen system, with the aim of examining the CO 2 uptake of each structural element under different exposure environments during the service life and recycling of the building. As input data necessary for the case study, data collected from actual surveys conducted in 2012 in South Korea were used, which included data on the surrounding environments, lifecycle inventory database, life expectancy of structures, and recycling activity scenario. Ultimately, the CO 2 uptake of concrete during a 100-year lifecycle (life expectancy of 40 years and recycling span of 60 years) was estimated to be 15.5%–17% of the CO 2 emissions from concrete production, which roughly corresponds to 18%–21% of the CO 2 emissions from the production of ordinary Portland cement. - Highlights: • CO 2 uptake assessment approach owing to the

  12. Potential and economics of CO2 sequestration

    International Nuclear Information System (INIS)

    Jean-Baptiste, Ph.; Ciais, Ph.; Orr, J.

    2001-01-01

    Increasing atmospheric level of greenhouse gases are causing global warming and putting at risk the global climate system. The main anthropogenic greenhouse gas is CO 2 . Some techniques could be used to reduced CO 2 emission and stabilize atmospheric CO 2 concentration, including i) energy savings and energy efficiency, ii) switch to lower carbon content fuels (natural gas) and use energy sources with zero CO 2 emissions such as renewable or nuclear energy, iii) capture and store CO 2 from fossil fuels combustion, and enhance the natural sinks for CO 2 (forests, soils, ocean...). The purpose of this report is to provide an overview of the technology and cost for capture and storage of CO 2 and to review the various options for CO 2 sequestration by enhancing natural carbon sinks. Some of the factors which will influence application, including environmental impact, cost and efficiency, are discussed. Capturing CO 2 and storing it in underground geological reservoirs appears as the best environmentally acceptable option. It can be done with existing technology, however, substantial R and D is needed to improve available technology and to lower the cost. Applicable to large CO 2 emitting industrial facilities such as power plants, cement factories, steel industry, etc., which amount to about 30% of the global anthropic CO 2 emission, it represents a valuable tool in the baffle against global warming. About 50% of the anthropic CO 2 is being naturally absorbed by the biosphere and the ocean. The 'natural assistance' provided by these two large carbon reservoirs to the mitigation of climate change is substantial. The existing natural sinks could be enhanced by deliberate action. Given the known and likely environmental consequences, which could be very damaging indeed, enhancing ocean sinks does not appears as a satisfactory option. In contrast, the promotion of land sinks through demonstrated carbon-storing approach to agriculture, forests and land management could

  13. Gas geochemistry and preliminary CO2 output estimation from the island of Kos (Greece)

    Science.gov (United States)

    D'Alessandro, Walter; Daskalopoulou, Kyriaki; Calabrese, Sergio; Longo, Manfredi; Kyriakopoulos, Konstantinos; Gagliano, Antonina Lisa

    2017-04-01

    Several gas samples have been collected from natural gas manifestations at the island of Kos. Most of them are found underwater along the southern coast of the island. On land two anomalous degassing areas have been recognized. These are characterised by lack of vegetation and after long dry periods by the presence of sulfate salts efflorescences. Almost all the gases are CO2-dominated (CO2 ranging from 88 to 99%) with minor amounts of N2 (up to 7%) and CH4 (up to 2.6%). Only the on-land manifestations have also significant contents of H2 (up to 0.2%) and H2S (up to 0.3%). Only one underwater manifestation is N2-dominated (61-99%) with CH4 (0.6-11%) and low CO2 (0.1-26%). The isotopic composition of He shows values ranging from 0.84 to 6.72 R/RA indicating a sometimes strong mantle contribution with the highest values measured in two of the most strongly degassing areas (Paradise Beach and Volcania). C-isotopic composition of CO2 is in the range from -3.6 to 0.6 ‰ vs V-PDB with most of the values around -1‰ indicating a mixed mantle - limestones origin. Isotopic composition of CH4, ranging from -21.5 to 2.8‰ for C and from -143 to 36‰ for H, points to a geothermal origin with sometimes evident secondary oxidation processes. CO2-flux measurements showed values up to about 10,000 g/m2/day in the areas of Volcania and Kokkino Nero and up to about 50,000 g/m2/day at Paradise beach. Preliminary CO2 output estimations gave values of 8.8 and 4 tons/day for the first two areas respectively and of 2.7 tons/day for the latter. The total output of the island (15.5 tons/day) should be considered a minimum estimation because of the incomplete coverage of the area and is comparable to the other active volcanic/geothermal systems of Greece (Nisyros, Nea Kameni and Methana).

  14. Carbon dioxide and hydrogen sulfide degassing and cryptic thermal input to Brimstone Basin, Yellowstone National Park, Wyoming

    Science.gov (United States)

    Bergfeld, D.; Evans, William C.; Lowenstern, J. B.; Hurwitz, S.

    2012-01-01

    Brimstone Basin, a remote area of intense hydrothermal alteration a few km east of the Yellowstone Caldera, is rarely studied and has long been considered to be a cold remnant of an ancient hydrothermal system. A field campaign in 2008 confirmed that gas emissions from the few small vents were cold and that soil temperatures in the altered area were at background levels. Geochemical and isotopic evidence from gas samples (3He/4He ~ 3RA, δ13C-CO2 ~ − 3‰) however, indicate continuing magmatic gas input to the system. Accumulation chamber measurements revealed a surprisingly large diffuse flux of CO2 (~ 277 t d-1) and H2S (0.6 t d-1). The flux of CO2 reduces the 18O content of the overlying cold groundwater and related stream waters relative to normal meteoric waters. Simple isotopic modeling reveals that the CO2 likely originates from geothermal water at a temperature of 93 ± 19 °C. These results and the presence of thermogenic hydrocarbons (C1:C2 ~ 100 and δ13C-CH4 = − 46.4 to − 42.8‰) in gases require some heat source at depth and refute the assumption that this is a “fossil” hydrothermal system.

  15. Electrocatalytic Alloys for CO2 Reduction.

    Science.gov (United States)

    He, Jingfu; Johnson, Noah J J; Huang, Aoxue; Berlinguette, Curtis P

    2018-01-10

    Electrochemically reducing CO 2 using renewable energy is a contemporary global challenge that will only be met with electrocatalysts capable of efficiently converting CO 2 into fuels and chemicals with high selectivity. Although many different metals and morphologies have been tested for CO 2 electrocatalysis over the last several decades, relatively limited attention has been committed to the study of alloys for this application. Alloying is a promising method to tailor the geometric and electric environments of active sites. The parameter space for discovering new alloys for CO 2 electrocatalysis is particularly large because of the myriad products that can be formed during CO 2 reduction. In this Minireview, mixed-metal electrocatalyst compositions that have been evaluated for CO 2 reduction are summarized. A distillation of the structure-property relationships gleaned from this survey are intended to help in the construction of guidelines for discovering new classes of alloys for the CO 2 reduction reaction. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Synthesis of Co 2SnO 4@C core-shell nanostructures with reversible lithium storage

    Science.gov (United States)

    Qi, Yue; Du, Ning; Zhang, Hui; Wu, Ping; Yang, Deren

    This paper reports the synthesis of Co 2SnO 4@C core-shell nanostructures through a simple glucose hydrothermal and subsequent carbonization approach. The as-synthesized Co 2SnO 4@C core-shell nanostructures have been applied as anode materials for lithium-ion batteries, which exhibit improved cyclic performance compared to pure Co 2SnO 4 nanocrystals. The carbon matrix has good volume buffering effect and high electronic conductivity, which may be responsible for the improved cyclic performance.

  17. CO2 Accounting and Risk Analysis for CO2 Sequestration at Enhanced Oil Recovery Sites.

    Science.gov (United States)

    Dai, Zhenxue; Viswanathan, Hari; Middleton, Richard; Pan, Feng; Ampomah, William; Yang, Changbing; Jia, Wei; Xiao, Ting; Lee, Si-Yong; McPherson, Brian; Balch, Robert; Grigg, Reid; White, Mark

    2016-07-19

    Using CO2 in enhanced oil recovery (CO2-EOR) is a promising technology for emissions management because CO2-EOR can dramatically reduce sequestration costs in the absence of emissions policies that include incentives for carbon capture and storage. This study develops a multiscale statistical framework to perform CO2 accounting and risk analysis in an EOR environment at the Farnsworth Unit (FWU), Texas. A set of geostatistical-based Monte Carlo simulations of CO2-oil/gas-water flow and transport in the Morrow formation are conducted for global sensitivity and statistical analysis of the major risk metrics: CO2/water injection/production rates, cumulative net CO2 storage, cumulative oil/gas productions, and CO2 breakthrough time. The median and confidence intervals are estimated for quantifying uncertainty ranges of the risk metrics. A response-surface-based economic model has been derived to calculate the CO2-EOR profitability for the FWU site with a current oil price, which suggests that approximately 31% of the 1000 realizations can be profitable. If government carbon-tax credits are available, or the oil price goes up or CO2 capture and operating expenses reduce, more realizations would be profitable. The results from this study provide valuable insights for understanding CO2 storage potential and the corresponding environmental and economic risks of commercial-scale CO2-sequestration in depleted reservoirs.

  18. Effects of tillage practice and atmospheric CO2 level on soil CO2 efflux

    Science.gov (United States)

    Elevated atmospheric carbon dioxide (CO2) affects both the quantity and quality of plant tissues, which impacts the cycling and storage of carbon (C) within plant/soil systems and thus the rate of CO2 release back to the atmosphere. Research to accurately quantify the effects of elevated CO2 and as...

  19. Estimating CO2 Emission Reduction of Non-capture CO2 Utilization (NCCU) Technology

    International Nuclear Information System (INIS)

    Lee, Ji Hyun; Lee, Dong Woog; Gyu, Jang Se; Kwak, No-Sang; Lee, In Young; Jang, Kyung Ryoung; Shim, Jae-Goo; Choi, Jong Shin

    2015-01-01

    Estimating potential of CO 2 emission reduction of non-capture CO 2 utilization (NCCU) technology was evaluated. NCCU is sodium bicarbonate production technology through the carbonation reaction of CO 2 contained in the flue gas. For the estimating the CO 2 emission reduction, process simulation using process simulator (PRO/II) based on a chemical plant which could handle CO 2 of 100 tons per day was performed, Also for the estimation of the indirect CO 2 reduction, the solvay process which is a conventional technology for the production of sodium carbonate/sodium bicarbonate, was studied. The results of the analysis showed that in case of the solvay process, overall CO 2 emission was estimated as 48,862 ton per year based on the energy consumption for the production of NaHCO 3 (7.4 GJ/tNaHCO 3 ). While for the NCCU technology, the direct CO 2 reduction through the CO 2 carbonation was estimated as 36,500 ton per year and the indirect CO 2 reduction through the lower energy consumption was 46,885 ton per year which lead to 83,385 ton per year in total. From these results, it could be concluded that sodium bicarbonate production technology through the carbonation reaction of CO 2 contained in the flue was energy efficient and could be one of the promising technology for the low CO 2 emission technology.

  20. Experimental and Numerical Modelling of CO2 Atmospheric Dispersion in Hazardous Gas Emission Sites.

    Science.gov (United States)

    Gasparini, A.; sainz Gracia, A. S.; Grandia, F.; Bruno, J.

    2015-12-01

    Under stable atmospheric conditions and/or in presence of topographic depressions, CO2 concentrations can reach high values resulting in lethal effect to living organisms. The distribution of denser than air gases released from the underground is governed by gravity, turbulence and dispersion. Once emitted, the gas distribution is initially driven by buoyancy and a gas cloud accumulates on the ground (gravitational phase); with time the density gradient becomes less important due to dispersion or mixing and gas distribution is mainly governed by wind and atmospheric turbulence (passive dispersion phase). Natural analogues provide evidences of the impact of CO2 leakage. Dangerous CO2 concentration in atmosphere related to underground emission have been occasionally reported although the conditions favouring the persistence of such a concentration are barely studied.In this work, the dynamics of CO2 in the atmosphere after ground emission is assessed to quantify their potential risk. Two approaches have been followed: (1) direct measurement of air concentration in a natural emission site, where formation of a "CO2 lake" is common and (2) numerical atmospheric modelling. Two sites with different morphology were studied: (a) the Cañada Real site, a flat terrain in the Volcanic Field of Campo de Calatrava (Spain); (b) the Solforata di Pomezia site, a rough terrain in the Alban Hills Volcanic Region (Italy). The comparison between field data and model calculations reveal that numerical dispersion models are capable of predicting the formation of CO2 accumulation over the ground as a consequence of underground gas emission. Therefore, atmospheric modelling could be included as a valuable methodology in the risk assessment of leakage in natural degassing systems and in CCS projects. Conclusions from this work provide clues on whether leakage may be a real risk for humans and under which conditions this risk needs to be included in the risk assessment.

  1. Isotopic tracers of sources, wells and of CO2 reactivity in geological reservoirs

    International Nuclear Information System (INIS)

    Assayag, N.

    2006-12-01

    The aim of this research works consisted in studying the behaviour of the carbonate system (dissolved inorganic carbon: DIC) following a CO 2 injection (artificial or natural), in geological reservoirs. One part of the study consisted in improving an analytical protocol for the measurement of δ 13 C DIC and DIC, using a continuous flow mass spectrometer. As a first study, we have focused our attention on the Pavin Lake (Massif Central, France). Owing to its limnologic characteristics (meromictic lake) and a deep volcanic CO 2 contribution, it can be viewed as a natural analogue of reservoir storing important quantities of CO 2 in the bottom part. Isotopic measurements (δ 18 O, δ 13 C DIC) allowed to better constrain the dynamics of the lake (stratification, seasonal variations), the magnitudes of biological activities (photosynthesis, organic matter decay, methane oxidation, methano-genesis), carbon sources (magmatic, methano-genetic), and the hydrological budgets (sub-lacustrine inputs). The second study was conducted on the Lamont-Doherty test well site (NY, USA). It includes an instrumental borehole which cuts through most of the section of the Palisades sill and into the Newark Basin sediments. Single well push-pull tests were performed: a test solution containing conservative tracers and a reactive tracer (CO 2 ) was injected at a permeable depth interval located in basaltic and meta sedimentary rocks. After an incubation period, the test solution/groundwater mixture was extracted from the hydraulically isolated zone. Isotopic measurements (δ 18 O, δ 13 C DIC) confronted to chemical data (major elements) allowed to investigate the extent of in-situ CO 2 -water-rock interactions: essentially calcite dissolution and at a lesser extend silicate dissolution...and for one of the test, CO 2 degassing. (author)

  2. A new device for continuous monitoring the CO2 dissolved in water

    Science.gov (United States)

    de Gregorio, S.; Camarda, M.; Cappuzzo, S.; Giudice, G.; Gurrieri, S.; Longo, M.

    2009-04-01

    The measurements of dissolved CO2 in water are common elements of industrial processes and scientific research. In order to perform gas dissolved measurements is required to separate the dissolved gaseous phase from water. We developed a new device able to separate the gases phase directly in situ and well suitable for continuous measuring the CO2 dissolved in water. The device is made by a probe of a polytetrafluorethylene (PTFE) tube connected to an I.R. spectrophotometer (I.R.) and a pump. The PTFE is a polymeric semi-permeable membrane and allows the permeation of gas in the system. Hence, this part of the device is dipped in water in order to equilibrate the probe headspace with the dissolved gases. The partial pressure of the gas i in the headspace at equilibrium (Pi) follows the Henry's law: Pi=Hi•Ci, where Hi is the Henry's constant and Ci is the dissolved concentration of gas i. After the equilibrium is achieved, the partial pressure of CO2 inside the tube is equal to the partial pressure of dissolved CO2. The concentration of CO2 is measured by the I.R. connected to the tube. The gas is moved from the tube headspace to the I.R. by using the pump. In order to test the device and assess the best operating condition, several experimental were performed in laboratory. All the test were executed in a special apparatus where was feasible to create controlled atmospheres. Afterward the device has been placed in a draining tunnel sited in the Mt. Etna Volcano edifice (Italy). The monitored groundwater intercepts the Pernicana Fault, along which degassing phenomena are often observed. The values recorded by the station result in agreement with monthly directly measurements of dissolved CO2 partial pressure.

  3. CO2 content of electricity losses

    International Nuclear Information System (INIS)

    Daví-Arderius, Daniel; Sanin, María-Eugenia; Trujillo-Baute, Elisa

    2017-01-01

    Countries are implementing policies to develop greener energy markets worldwide. In Europe, the ¨2030 Energy and Climate Package¨ asks for further reductions of green house gases, renewable sources integration, and energy efficiency targets. But the polluting intensity of electricity may be different in average than when considering market inefficiencies, in particular losses, and therefore the implemented policy must take those differences into account. Precisely, herein we study the importance in terms of CO2 emissions the extra amount of energy necessary to cover losses. With this purpose we use Spanish market and system data with hourly frequency from 2011 to 2013. Our results show that indeed electricity losses significantly explain CO2 emissions, with a higher CO2 emissions rate when covering losses than the average rate of the system. Additionally, we find that the market closing technologies used to cover losses have a positive and significant impact on CO2 emissions: when polluting technologies (coal or combined cycle) close the market, the impact of losses on CO2 emissions is high compared to the rest of technologies (combined heat and power, renewables or hydropower). To the light of these results we make some policy recommendations to reduce the impact of losses on CO2 emissions. - Highlights: • Electricity losses significantly explain CO2 emissions. • Policies aimed to reducing losses have a positive impact on CO2 emissions. • The market closing technology used to cover losses have impacts on CO2 emissions. • Pollutant technologies that close the market should be replaced by renewables.

  4. CO2 fluxes near a forest edge

    DEFF Research Database (Denmark)

    Sogachev, Andrey; Leclerc, Monique Y.; Zhang, Gensheng

    2008-01-01

    In contrast with recent advances on the dynamics of the flow at a forest edge, few studies have considered its role on scalar transport and, in particular, on CO2 transfer. The present study addresses the influence of the abrupt roughness change on forest atmosphere CO2 exchange and contrasts...... as a function of both sources/sinks distribution and the vertical structure of the canopy. Results suggest that the ground source plays a major role in the formation of wave-like vertical CO2 flux behavior downwind of a forest edge, despite the fact that the contribution of foliage sources/sinks changes...

  5. CO2, the promises of geological sequestration

    International Nuclear Information System (INIS)

    Rouat, S.

    2006-01-01

    Trapping part of the world CO 2 effluents in the deep underground is a profitable and ecological way to limit the global warming. This digest paper presents the different ways of CO 2 sequestration (depleted oil and gas fields, unexploited coal seams, saline aquifers), the other possible solutions for CO 2 abatement (injection in the bottom of the ocean, conversion into carbonates by injection into basic rocks, fixation by photosynthesis thanks to micro-algae cultivation), and takes stock of the experiments in progress (Snoehvit field in Norway, European project Castor). (J.S.)

  6. Climate change and the CO2 myth

    International Nuclear Information System (INIS)

    Boettcher, C.J.F.

    1994-01-01

    Further increase of the CO 2 concentration in the atmosphere has little effect on the greenhouse effect contrary to the effect of the increase of other greenhouse gases. However, politicians are using targets for the reduction of CO 2 emissions that are unrealistic, taking into account the scientific uncertainties of the applied models, the doubts about the feasibility of quantitative targets and the economic consequences of such drastic measures. Some recommendations are given for a more realistic CO 2 policy. Also attention is paid to the important role that coal will play in the future of the energy supply. 5 figs., 3 ills

  7. Anomalous Diffuse CO2 Emission Changes at San Vicente Volcano Related to Earthquakes in El Salvador, Central America

    Science.gov (United States)

    Salazar, J.; Hernandez, P.; Perez, N.; Barahona, F.; Olmos, R.; Cartagena, R.; Soriano, T.; Notsu, K.; Lopez, D.

    2001-12-01

    San Vicente or Chichontepeque (2,180 m a.s.l.) is a composite andesitic volcano located 50 Km east of San Salvador. Its paired edifice rises from the so-called Central Graben, an extensional structure parallel to the Pacific coast, and has been inactive for the last 3000 yrs. Fumaroles (98.2°C ) and hot spring waters are present along radial faults at two localities on the northern slope of the volcano (Aguas Agrias and El Infiernillo). CO2 is the most abundant component in the dry gas (>90%) and its mean isotopic composition (δ 13C(CO2)=-2.11 ‰ and 3He/4He of 6.9 Ra) suggests a magmatic origin for the CO2. These manifestations are supposed to be linked to a 1,200 m depth 250°C reservoir with a CO2 partial pressure of 14 bar extended beneath the volcano (Aiuppa et al., 1997). In February 13, 2001, a 6.6 magnitude earthquake with epicenter about 20 Km W of San Vicente damaged and destroyed many towns and villages in the north area of the volcano causing some deceases. In addition, two seismic swarms were recorded beneath the northeastern flank of the volcano in April and May 2001. Searching for any link between the actual seismic activity and changes in the diffuse CO2 degassing at San Vicente, an NDIR instrument for continuos monitoring of the diffuse CO2 degassing was set up at Aguas Agrias in March 2001. Soil CO2 efflux and several meteorological and soil physical variables were measured in an hourly basis. Very significative pre-seismic and post-seismic relationships have been found in the observed diffuse CO2 efflux temporal variations related to the May 2001 seismic swarms. A sustained 50% increase on the average diffuse CO2 efflux was observed 8 days before the May 8, 5.1 magnitude earthquake. This pre-seismic behaviour may be considered a precursor of the May 2001 seismic swarm at San Vicente volcano. However, about a three-fold increase in the diffuse CO2 efflux was also observed after the intense seismicity recorded on May 8-9. These preliminary

  8. Equilibration of metabolic CO2 with preformed CO2 and bicarbonate

    International Nuclear Information System (INIS)

    Hems, R.; Saez, G.T.

    1983-01-01

    Entry of metabolic 14 CO 2 into urea is shown to occur more readily than it equilibrates with the general pool of cellular plus extracellular bicarbonate plus CO 2 . Since the sites of CO 2 production (pyruvate dehydrogenase and oxoglutarate dehydrogenase) and of fixation (carbamoylphosphate synthetase) are intramitochondrial, it is likely that the fixation of CO 2 is also more rapid than its equilibration with the cytoplasmic pool of bicarbonate plus CO 2 . This observation may point to a more general problem concerning the interpretation of isotope data, with compartmentation or proximity of sites of production and utilisation of metabolites may result in the isotope following a preferred pathway. (Auth.)

  9. CO2 Capture by Cement Raw Meal

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar; Lin, Weigang; Illerup, Jytte Boll

    2013-01-01

    The cement industry is one of the major sources of CO2 emissions and is likely to contribute to further increases in the near future. The carbonate looping process has the potential to capture CO2 emissions from the cement industry, in which raw meal for cement production could be used...... as the sorbent. Cyclic experiments were carried out in a TGA apparatus using industrial cement raw meal and synthetic raw meal as sorbents, with limestone as the reference. The results show that the CO2 capture capacities of the cement raw meal and the synthetic raw meal are comparable to those of pure limestone...... that raw meal could be used as a sorbent for the easy integration of the carbonate looping process into the cement pyro process for reducing CO2 emissions from the cement production process....

  10. Energy Efficiency instead of CO2 levy

    International Nuclear Information System (INIS)

    Uetz, R.

    2005-01-01

    This article takes a look at ways of avoiding a future, planned Swiss CO 2 levy by improving the efficiency of energy use. The political situation concerning the reduction of CO 2 emissions in Switzerland is reviewed and the likeliness of the introduction of a CO 2 levy is discussed. Strategies for the reduction of fossil fuel consumption and therefore of CO 2 emissions are looked at, including process optimisation. Recommendations are made on how to approach this work systematically - data collection, assessment of the potential for reduction and the planning of measures to be taken are looked at. The high economic efficiency of immediate action is stressed and typical middle and long-term measures are listed

  11. The ATLAS IBL CO2 Cooling System

    CERN Document Server

    Verlaat, Bartholomeus; The ATLAS collaboration

    2016-01-01

    The Atlas Pixel detector has been equipped with an extra B-layer in the space obtained by a reduced beam pipe. This new pixel detector called the ATLAS Insertable B-Layer (IBL) is installed in 2014 and is operational in the current ATLAS data taking. The IBL detector is cooled with evaporative CO2 and is the first of its kind in ATLAS. The ATLAS IBL CO2 cooling system is designed for lower temperature operation (<-35⁰C) than the previous developed CO2 cooling systems in High Energy Physics experiments. The cold temperatures are required to protect the pixel sensors for the high expected radiation dose up to 550 fb^-1 integrated luminosity. This paper describes the design, development, construction and commissioning of the IBL CO2 cooling system. It describes the challenges overcome and the important lessons learned for the development of future systems which are now under design for the Phase-II upgrade detectors.

  12. Capture and geological storage of CO2

    International Nuclear Information System (INIS)

    2013-03-01

    Capture and geological storage of CO 2 could be a contribution to reduce CO 2 emissions, and also a way to meet the factor 4 objective of reduction of greenhouse gas emissions. This publication briefly presents the capture and storage definitions and principles, and comments some key data related to CO 2 emissions, and their natural trapping by oceans, soils and forests. It discusses strengths (a massive and perennial reduction of CO 2 emissions, a well defined regulatory framework) and weaknesses (high costs and uncertain cost reduction perspectives, a technology which still consumes a lot of energy, geological storage capacities still to be determined, health environmental impacts and risks to be controlled, a necessary consultation of population for planned projects) of this option. Actions undertaken by the ADEME are briefly reviewed

  13. CO2 Washout Capability with Breathing Manikin

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon Dioxide (CO2) Washout performance is a critical parameter needed to ensure proper and sufficient designs in a spacesuit and in vehicle applications such as...

  14. Emerging terawatt picosecond CO2 laser technology

    International Nuclear Information System (INIS)

    Pogorelsky, I.V.

    1997-09-01

    The first terawatt picosecond (TWps) CO 2 laser is under construction at the BNL Accelerator Test Facility (ATF). TWps-CO 2 lasers, having an order of magnitude longer wavelength than the well-known table-top terawatt solid state lasers, offer new opportunities for strong-field physics research. For laser wakefield accelerators (LWFA) the advantage of the new class of lasers is due to a gain of two orders of magnitude in the ponderomotive potential. The large average power of CO 2 lasers is important for the generation of hard radiation through Compton back-scattering of the laser off energetic electron beams. The authors discuss applications of TWps-CO 2 lasers for LWFA modules of a tentative electron-positron collider, for γ-γ (or γ-lepton) colliders, for a possible table-top source of high-intensity x-rays and gamma rays, and the generation of polarized positron beams

  15. Porous Organic Polymers for CO2 Capture

    KAUST Repository

    Teng, Baiyang

    2013-01-01

    to reduce the emission of CO2 to atmosphere. Porous organic polymers (POPs) are promising candidates for this application due to their readily tunable textual properties and surface functionalities. The objective of this thesis work is to develop new POPs

  16. Upscaling of enzyme enhanced CO2 capture

    DEFF Research Database (Denmark)

    Gladis, Arne Berthold

    Fossil fuels are the backbone of the energy generation in the coming decades for USA, China, India and Europe, hence high greenhouse gas emissions are expected in future. Carbon capture and storage technology (CCS) is the only technology that can mitigate greenhouse gas emissions from fossil fuel...... the mass transfer of CO2 with slow-capturing but energetically favorable solvents can open up a variety of new process options for this technology. The ubiquitous enzyme carbonic anhydrase (CA), which enhances the mass transfer of CO2 in the lungs by catalyzing the reversible hydration of CO2, is one very...... enhanced CO2 capture technology by identifying the potentials and limitations in lab and in pilot scale and benchmarking the process against proven technologies. The main goal was to derive a realistic process model for technical size absorbers with a wide range of validity incorporating a mechanistic...

  17. Application of Hydrothermal Treatment to High Concentrated Sewage Sludge for Anaerobic Digestion Process

    OpenAIRE

    M. Orikawa; H. Kamahara; Y. Atsuta; H. Daimon

    2013-01-01

    Tomato and seaweed were produced by utilizing CO2 and heat discharged from power generation using biogas in Toyogawa biomass park, Japan. The biogas was obtained by anaerobic digestion with hydrothermal treatment. The hydrothermal treatment was applied to the high concentrated sewage sludge (22 % total solids (TS) dewatered sludge). The purpose of this study is to clarify the effect of hydrothermal treatment on the qualities of high concentrated sewage sludge, by analyzing particulate organic...

  18. Natural Analogues of CO2 Geological Storage

    International Nuclear Information System (INIS)

    Perez del Villar, L.; Pelayo, M.; Recreo, F.

    2007-01-01

    Geological storage of carbon dioxide is nowadays, internationally considered as the most effective method for greenhouse gas emission mitigation, in order to minimize the global climate change universally accepted. Nevertheless, the possible risks derived of this long-term storage have a direct influence on its public acceptance. Among the favourable geological formations to store CO2, depleted oil and gas fields, deep saline reservoirs, and unamiable coal seams are highlighted. One of the most important objectives of the R and D projects related to the CO2 geological storage is the evaluation of the CO2 leakage rate through the above mentioned geological formations. Therefore, it is absolutely necessary to increase our knowledge on the interaction among CO2, storage and sealing formations, as well as on the flow paths and the physical resistance of the sealing formation. The quantification of the CO2 leakage rate is essential to evaluate the effects on the human and animal health, as well as for the ecosystem and water quality. To achieve these objectives, the study of the natural analogues is very useful in order to know the natural leakage rate to the atmosphere, its flow paths, the physical, chemical and mineralogical modifications due to the long term interaction processes among the CO2 and the storage and sealing formations, as well as the effects on the groundwaters and ecosystems. In this report, we have tried to summarise the main characteristics of the natural reservoirs and surficial sources of CO2, which are both natural analogues of the geological storage and CO2 leakage, studied in EEUU, Europe and Australia. The main objective of this summary is to find the possible applications for long-term risk prediction and for the performance assessment by means of conceptual and numerical modelling, which will allow to validate the predictive models of the CO2 storage behaviour, to design and develop suitable monitoring techniques to control the CO2 behaviour

  19. CO2 emissions of nuclear power supply

    International Nuclear Information System (INIS)

    Wissel, S.; Mayer-Spohn, O.; Fahl, U.; Voss, A.

    2007-01-01

    Increasingly, supported by the recent reports of the IPCC (International Panel on Climate Change), political, social and scientific institutions call for the use of atomic energy for reducing CO2 emissions. In Germany, the discussion is highly controversial. A life-cycle balance of nuclear power shows that its CO2 emissions are much lower than those of other technologies, even if changes in the nuclear fuel cycle are taken into account. (orig.)

  20. Photoacoustic CO2-Sensor for Automotive Applications

    OpenAIRE

    Huber, J.; Weber, C.; Eberhardt, A.; Wöllenstein, J.

    2016-01-01

    We present a field-tested miniaturized spectroscopic CO2 sensor which is based on the photoacoustic effect. The sensor is developed for automotive applications and considers the requirements for the usage in vehicles. The sensor measures two measurement ranges simultaneously: The monitoring of the indoor air quality and the detection of possible leakages of the coolant in CO2 air-conditioning systems. The sensor consists of a miniaturized innovative photoacoustic sensor unit with integrated e...

  1. Study on CO2 global recycling system

    International Nuclear Information System (INIS)

    Takeuchi, M.; Sakamoto, Y.; Niwa, S.

    2001-01-01

    In order to assist in finding ways to mitigate CO 2 emission and to slow the depletion of fossil fuels we have established and evaluated a representative system, which consists of three technologies developed in our laboratory. These technologies were in CO 2 recovery, hydrogen production and methanol synthesis and in addition we established the necessary supporting systems. Analysis of outline designs of the large scale renewable energy power generation system and this system and energy input for building plant, energy input for running plant has been conducted based on a case using this system for a 1000-MW coal fired power plant, followed by an evaluation of the material balance and energy balance. The results are as follows. Energy efficiency is 34%, the CO 2 reduction rate is 41%, the balance ratio of the energy and CO 2 of the system is 2.2 and 1.8, respectively, on the assumption that the primary renewable energy is solar thermal power generation, the stationary CO 2 emission source is a coal-fired power plant and the generation efficiency of the methanol power plant is 60%. By adopting the system, 3.7 million tons of CO 2 can be recovered, approximately 2.7 million tons of methanol can be produced, and 15.4 billion kWh of electricity can be generated per year. Compared to generating all electrical power using only coal, approximately 2.6 million tons of coal per year can be saved and approximately 2.15 million tons of CO 2 emission can be reduced. Therefore, it is clearly revealed that this system would be effective to reduce CO 2 emissions and to utilize renewable energy

  2. Anthropogenic CO2 in the ocean

    Directory of Open Access Journals (Sweden)

    Tsung-Hung Peng

    2005-06-01

    Full Text Available The focus of this review article is on the anthropogenic CO2 taken up by the ocean. There are several methods of identifying the anthropogenic CO2 signal and quantifying its inventory in the ocean. The ?C* method is most frequently used to estimate the global distribution of anthropogenic CO2 in the ocean. Results based on analysis of the dataset obtained from the comprehensive surveys of inorganic carbon distribution in the world oceans in the 1990s are given. These surveys were jointly conducted during the World Ocean Circulation Experiment (WOCE and the Joint Global Ocean Flux Study (JGOFS. This data set consists of 9618 hydrographic stations from a total of 95 cruises, which represents the most accurate and comprehensive view of the distribution of inorganic carbon in the global ocean available today. The increase of anthropogenic CO2 in the ocean during the past few decades is also evaluated using direct comparison of results from repeat surveys and using statistical method of Multi-parameter Linear Regression (MLR. The impact of increasing oceanic anthropogenic CO2 on the calcium carbonate system in the ocean is reviewed briefly as well. Extensive studies of CaCO3 dissolution as a result of increasing anthropogenic CO2 in the ocean have revealed several distinct oceanic regions where the CaCO3 undersaturation zone has expanded.

  3. Recent developments in CO2 lasers

    Science.gov (United States)

    Du, Keming

    1993-05-01

    CO2 lasers have been used in industry mainly for such things as cutting, welding, and surface processing. To conduct a broad spectrum of high-speed and high-quality applications, most of the developments in industrial CO2 lasers at the ILT are aimed at increasing the output power, optimizing the beam quality, and reducing the production costs. Most of the commercial CO2 lasers above 5 kW are transverse-flow systems using dc excitation. The applications of these lasers are limited due to the lower beam quality, the poor point stability, and the lower modulation frequency. To overcome the problems we developed a fast axial- flow CO2 laser using rf excitation with an output of 13 kW. In section 2 some of the results are discussed concerning the gas flow, the discharge, the resonator design, optical effects of active medium, the aerodynamic window, and the modulation of the output power. The first CO2 lasers ever built are diffusion-cooled systems with conventional dc excited cylindrical discharge tubes surrounded by cooling jackets. The output power per unit length is limited to 50 W/m by those lasers with cylindrical tubes. In the past few years considerable increases in the output power were achieved, using new mechanical geometries, excitation- techniques, and resonator designs. This progress in diffusion-cooled CO2 lasers is presented in section 3.

  4. CO2 efflux from cleared mangrove peat.

    Directory of Open Access Journals (Sweden)

    Catherine E Lovelock

    Full Text Available CO(2 emissions from cleared mangrove areas may be substantial, increasing the costs of continued losses of these ecosystems, particularly in mangroves that have highly organic soils.We measured CO(2 efflux from mangrove soils that had been cleared for up to 20 years on the islands of Twin Cays, Belize. We also disturbed these cleared peat soils to assess what disturbance of soils after clearing may have on CO(2 efflux. CO(2 efflux from soils declines from time of clearing from ∼10,600 tonnes km(-2 year(-1 in the first year to 3000 tonnes km(2 year(-1 after 20 years since clearing. Disturbing peat leads to short term increases in CO(2 efflux (27 umol m(-2 s(-1, but this had returned to baseline levels within 2 days.Deforesting mangroves that grow on peat soils results in CO(2 emissions that are comparable to rates estimated for peat collapse in other tropical ecosystems. Preventing deforestation presents an opportunity for countries to benefit from carbon payments for preservation of threatened carbon stocks.

  5. How much CO2 is trapped in carbonate minerals of a natural CO2 occurrence?

    Science.gov (United States)

    Király, Csilla; Szabó, Zsuzsanna; Szamosfalvi, Ágnes; Cseresznyés, Dóra; Király, Edit; Szabó, Csaba; Falus, György

    2017-04-01

    Carbon Capture and Storage (CCS) is a transitional technology to decrease CO2 emissions from human fossil fuel usage and, therefore, to mitigate climate change. The most important criteria of a CO2 geological storage reservoir is that it must hold the injected CO2 for geological time scales without its significant seepage. The injected CO2 undergoes physical and chemical reactions in the reservoir rocks such as structural-stratigraphic, residual, dissolution or mineral trapping mechanisms. Among these, the safest is the mineral trapping, when carbonate minerals such as calcite, ankerite, siderite, dolomite and dawsonite build the CO2 into their crystal structures. The study of natural CO2 occurrences may help to understand the processes in CO2 reservoirs on geological time scales. This is the reason why the selected, the Mihályi-Répcelak natural CO2 occurrence as our research area, which is able to provide particular and highly significant information for the future of CO2 storage. The area is one of the best known CO2 fields in Central Europe. The main aim of this study is to estimate the amount of CO2 trapped in the mineral phase at Mihályi-Répcelak CO2 reservoirs. For gaining the suitable data, we apply petrographic, major and trace element (microprobe and LA-ICP-MS) and stable isotope analysis (mass spectrometry) and thermodynamic and kinetic geochemical models coded in PHREEQC. Rock and pore water compositions of the same formation, representing the pre-CO2 flooding stages of the Mihályi-Répcelak natural CO2 reservoirs are used in the models. Kinetic rate parameters are derived from the USGS report of Palandri and Kharaka (2004). The results of petrographic analysis show that a significant amount of dawsonite (NaAlCO3(OH)2, max. 16 m/m%) precipitated in the rock due to its reactions with CO2 which flooded the reservoir. This carbonate mineral alone traps about 10-30 kg/m3 of the reservoir rock from the CO2 at Mihályi-Répcelak area, which is an

  6. How secure is subsurface CO2 storage? Controls on leakage in natural CO2 reservoirs

    Science.gov (United States)

    Miocic, Johannes; Gilfillan, Stuart; McDermott, Christopher; Haszeldine, Stuart

    2014-05-01

    Carbon Capture and Storage (CCS) is the only industrial scale technology available to directly reduce carbon dioxide (CO2) emissions from fossil fuelled power plants and large industrial point sources to the atmosphere. The technology includes the capture of CO2 at the source and transport to subsurface storage sites, such as depleted hydrocarbon reservoirs or saline aquifers, where it is injected and stored for long periods of time. To have an impact on the greenhouse gas emissions it is crucial that there is no or only a very low amount of leakage of CO2 from the storage sites to shallow aquifers or the surface. CO2 occurs naturally in reservoirs in the subsurface and has often been stored for millions of years without any leakage incidents. However, in some cases CO2 migrates from the reservoir to the surface. Both leaking and non-leaking natural CO2 reservoirs offer insights into the long-term behaviour of CO2 in the subsurface and on the mechanisms that lead to either leakage or retention of CO2. Here we present the results of a study on leakage mechanisms of natural CO2 reservoirs worldwide. We compiled a global dataset of 49 well described natural CO2 reservoirs of which six are leaking CO2 to the surface, 40 retain CO2 in the subsurface and for three reservoirs the evidence is inconclusive. Likelihood of leakage of CO2 from a reservoir to the surface is governed by the state of CO2 (supercritical vs. gaseous) and the pressure in the reservoir and the direct overburden. Reservoirs with gaseous CO2 is more prone to leak CO2 than reservoirs with dense supercritical CO2. If the reservoir pressure is close to or higher than the least principal stress leakage is likely to occur while reservoirs with pressures close to hydrostatic pressure and below 1200 m depth do not leak. Additionally, a positive pressure gradient from the reservoir into the caprock averts leakage of CO2 into the caprock. Leakage of CO2 occurs in all cases along a fault zone, indicating that

  7. CO2 Emission Factors for Coals

    Directory of Open Access Journals (Sweden)

    P. Orlović-Leko

    2015-03-01

    Full Text Available Emission factors are used in greenhouse gas inventories to estimate emissions from coal combustion. In the absence of direct measures, emissions factors are frequently used as a quick, low cost way to estimate emissions values. Coal combustion has been a major contributor to the CO2 flux into the atmosphere. Nearly all of the fuel carbon (99 % in coal is converted to CO2 during the combustion process. The carbon content is the most important coal parameter which is the measure of the degree of coalification (coal rank. Coalification is the alteration of vegetation to form peat, succeeded by the transformation of peat through lignite, sub-bituminous, bituminous to anthracite coal. During the geochemical or metamorphic stage, the progressive changes that occur within the coal are an increase in the carbon content and a decrease in the hydrogen and oxygen content resulting in a loss of volatiles. Heterogeneous composition of coal causes variation in CO2 emission from different coals. The IPCC (Intergovernmental Panel on Climate Change has produced guidelines on how to produce emission inventories which includes emission factors. Although 2006 IPCC Guidelines provided the default values specified according to the rank of the coal, the application of country-specific emission factors was recommended when estimating the national greenhouse gas emissions. This paper discusses the differences between country-specific emission factors and default IPCC CO2 emission factors, EF(CO2, for coals. Also, this study estimated EF(CO2 for two different types of coals and peat from B&H, on the basis fuel analyses. Carbon emission factors for coal mainly depend on the carbon content of the fuel and vary with both rank and geographic origin, which supports the idea of provincial variation of carbon emission factors. Also, various other factors, such as content of sulphur, minerals and macerals play an important role and influence EF(CO2 from coal. Carbonate minerals

  8. Tree-ring 14C links seismic swarm to CO2 spike at Yellowstone, USA

    Science.gov (United States)

    Evans, William C.; Bergfeld, D.; McGeehin, J.P.; King, J.C.; Heasler, H.

    2010-01-01

    Mechanisms to explain swarms of shallow seismicity and inflation-deflation cycles at Yellowstone caldera (western United States) commonly invoke episodic escape of magma-derived brines or gases from the ductile zone, but no correlative changes in the surface efflux of magmatic constituents have ever been documented. Our analysis of individual growth rings in a tree core from the Mud Volcano thermal area within the caldera links a sharp ~25% drop in 14C to a local seismic swarm in 1978. The implied fivefold increase in CO2 emissions clearly associates swarm seismicity with upflow of magma-derived fluid and shows that pulses of magmatic CO2 can rapidly traverse the 5-kmthick brittle zone, even through Yellowstone's enormous hydrothermal reservoir. The 1978 event predates annual deformation surveys, but recognized connections between subsequent seismic swarms and changes in deformation suggest that CO2 might drive both processes. ?? 2010 Geological Society of America.

  9. Magnetic properties of Co2-xCux(OH)PO4 (x=0, 1 and 2)

    International Nuclear Information System (INIS)

    Pedro, I. de; Jubera, V.; Rojo, J.M.; Lezama, L.; Sanchez Marcos, J.; Rodriguez Fernandez, J.; Mesa, J.L.; Rojo, T.; Arriortua, M.I.

    2004-01-01

    The isostructural Co 2-x Cu x (OH)PO 4 (x=0, 1 and 2) phases have been prepared from hydrothermal synthesis and characterized from powder X-ray diffraction. The structure consists of a three-dimensional framework in which M(1)O 5 -trigonal bipyramid dimers and M(2)O 6 -octahedral chains are simultaneously present. Magnetization measurements of Co 2 (OH)(PO 4 ) show the existence of two maxima attributed to a three-dimensional antiferromagnetic ordering at 70 K and a spin-glass-like state at 12 K. When Co 2+ is substituted by Cu 2+ ions, the spin-glass behavior disappears and the magnetic order is decreased

  10. Revealing fate of CO2 leakage pathways in the Little Grand Wash Fault, Green River, Utah

    Science.gov (United States)

    Han, K.; Han, W. S.; Watson, Z. T.; Guyant, E.; Park, E.

    2015-12-01

    To assure long-term security of geologic carbon sequestration site, evaluation of natural CO2 leakage should be preceded before actual construction of the CO2 facility by comparing natural and artificial reservoir systems. The Little Grand Wash fault is located at the northwestern margin of the Paradox Basin and roles on a bypass of deep subsurface CO2 and brine water onto the surface, e.g., cold water geyser, CO2 spring, and surface travertine deposits. CO2 degassed out from brine at the Little Grand Wash fault zone may react with formation water and minerals while migrating through the fault conduit. Leakage observed by soil CO2 flux on the fault trace shows this ongoing transition of CO2, from supersaturated condition in deep subsurface to shallow surface equilibria. The present study aims to investigate the reactions induced by changes in hydrological and mineralogical factors inside of the fault zone. The methodology to develop site-specific geochemical model of the Little Grand Wash Fault combines calculated mechanical movements of each fluid end-member, along with chemical reactions among fluid, free CO2 gas and rock formations. Reactive transport modeling was conducted to simulate these property changes inside of the fault zone, using chemistry dataset based on 86 effluent samples of CO2 geysers, springs and in situ formation water from Entrada, Carmel, and Navajo Sandstone. Meanwhile, one- and two-dimensional models were separately developed to delineate features mentioned above. The results from the 3000-year simulation showed an appearance of self-sealing processes near the surface of the fault conduit. By tracking physicochemical changes at the depth of 15 m on the 2-dimensional model, significant changes induced by fluid mixing were indicated. Calculated rates of precipitation for calcite, illite, and pyrite showed increase in 2.6 x 10-4, 2.25 x 10-5, and 3.0 x 10-6 in mineral volume fraction at the depth of 15m, respectively. Concurrently

  11. Microbiological and Geochemical Survey of CO2-Dominated Mofette and Mineral Waters of the Cheb Basin, Czech Republic

    Directory of Open Access Journals (Sweden)

    Patryk Krauze

    2017-12-01

    Full Text Available The Cheb Basin (NW Bohemia, Czech Republic is a shallow, neogene intracontinental basin. It is a non-volcanic region which features frequent earthquake swarms and large-scale diffuse degassing of mantle-derived CO2 at the surface that occurs in the form of CO2-rich mineral springs and wet and dry mofettes. So far, the influence of CO2 degassing onto the microbial communities has been studied for soil environments, but not for aquatic systems. We hypothesized, that deep-trenching CO2 conduits interconnect the subsurface with the surface. This admixture of deep thermal fluids should be reflected in geochemical parameters and in the microbial community compositions. In the present study four mineral water springs and two wet mofettes were investigated through an interdisciplinary survey. The waters were acidic and differed in terms of organic carbon and anion/cation concentrations. Element geochemical and isotope analyses of fluid components were used to verify the origin of the fluids. Prokaryotic communities were characterized through quantitative PCR and Illumina 16S rRNA gene sequencing. Putative chemolithotrophic, anaerobic and microaerophilic organisms connected to sulfur (e.g., Sulfuricurvum, Sulfurimonas and iron (e.g., Gallionella, Sideroxydans cycling shaped the core community. Additionally, CO2-influenced waters form an ecosystem containing many taxa that are usually found in marine or terrestrial subsurface ecosystems. Multivariate statistics highlighted the influence of environmental parameters such as pH, Fe2+ concentration and conductivity on species distribution. The hydrochemical and microbiological survey introduces a new perspective on mofettes. Our results support that mofettes are either analogs or rather windows into the deep biosphere and furthermore enable access to deeply buried paleo-sediments.

  12. Diffuse CO2 flux emissions from the soil in Las Cañadas caldera (Tenerife, Canary Islands)

    Science.gov (United States)

    Luengo-Oroz, Natividad; Torres, Pedro A.; Moure, David; D'Alessandro, Walter; Liuzzo, Marco; Longo, Manfredi; Pecoraino, Giovannella

    2014-05-01

    Starting in April 2004, unusual seismic activity was observed in the interior of the island of Tenerife (Canary Islands, Spain) with much evidence pointing to a reawakening of volcanic activity. During this seismic crisis, several events were felt by the population. Since then, a dense multiparametric monitoring network has been deployed all over the island by Instituto Geográfico Nacional (IGN). In the framework of this volcanic surveillance project, several geochemical studies have been accomplished. Measurements of diffuse CO2 flux from the soil have been carried out in some zones inside Las Cañadas caldera. This study has been performed during three different field campaigns in November 2012 and June and November 2013. The studied area includes two different zones known as Roques de García and Los Azulejos. Since several authors have reported the existence of fractures and faults all along both structures, the objectives of this work were to find anomalous CO2 fluxes from the soil and preferential degassing areas, identify possible hidden faults and study the origin of gas emanations in order to detect the presence of magmatic sources. More than 600 sampling sites have been measured with the accumulation chamber method in an area of about 1 km2. Soil gas has been sampled in points where high CO2 fluxes were detected for the determination of chemical and isotopic composition. The results of the gas prospection confirm the existence of CO2 degassing in the area. Some anomalous fluxes have been measured along previously inferred volcano-tectonic structures. The highest anomalies were found in Los Azulejos with values up to 1774 g/m2.d. Chemical analysis did not reveal significant concentrations of magmatic or geothermal gases except CO2. The latter showed concentrations at 50 cm depth within the soils up to 48% and a C-isotopic composition between -4.72 and -3.67 o indicating a prevailing magmatic origin.

  13. Exploring the structural controls on helium, nitrogen and carbon isotope signatures in hydrothermal fluids along an intra-arc fault system

    Science.gov (United States)

    Tardani, Daniele; Reich, Martin; Roulleau, Emilie; Takahata, Naoto; Sano, Yuji; Pérez-Flores, Pamela; Sánchez-Alfaro, Pablo; Cembrano, José; Arancibia, Gloria

    2016-07-01

    There is a general agreement that fault-fracture meshes exert a primary control on fluid flow in both volcanic/magmatic and geothermal/hydrothermal systems. For example, in geothermal systems and epithermal gold deposits, optimally oriented faults and fractures play a key role in promoting fluid flow through high vertical permeability pathways. In the Southern Volcanic Zone (SVZ) of the Chilean Andes, both volcanism and hydrothermal activity are strongly controlled by the Liquiñe-Ofqui Fault System (LOFS), an intra-arc, strike-slip fault, and by the Arc-oblique Long-lived Basement Fault System (ALFS), a set of transpressive NW-striking faults. However, the role that principal and subsidiary fault systems exert on magma degassing, hydrothermal fluid flow and fluid compositions remains poorly constrained. In this study we report new helium, carbon and nitrogen isotope data (3He/4He, δ13C-CO2 and δ15N) of a suite of fumarole and hot spring gas samples from 23 volcanic/geothermal localities that are spatially associated with either the LOFS or the ALFS in the central part of the SVZ. The dataset is characterized by a wide range of 3He/4He ratios (3.39 Ra to 7.53 Ra, where Ra = (3He/4He)air), δ13C-CO2 values (-7.44‰ to -49.41‰) and δ15N values (0.02‰ to 4.93‰). The regional variations in 3He/4He, δ13C-CO2 and δ15N values are remarkably consistent with those reported for 87Sr/86Sr in lavas along the studied segment, which are strongly controlled by the regional spatial distribution of faults. Two fumaroles gas samples associated with the northern ;horsetail; transtensional termination of the LOFS are the only datapoints showing uncontaminated MORB-like 3He/4He signatures. In contrast, the dominant mechanism controlling helium isotope ratios of hydrothermal systems towards the south appears to be the mixing between mantle-derived helium and a radiogenic component derived from, e.g., magmatic assimilation of 4He-rich country rocks or contamination during the

  14. Studies on CO2 removal and reduction. CO2 taisaku kenkyu no genjo

    Energy Technology Data Exchange (ETDEWEB)

    Shindo, Y [National Institute of Materials and Chemical Research, Tsukuba (Japan)

    1993-02-01

    This paper summarizes study trends mainly in CO2 fixing processes. Underground CO2 storage is a most promising method because it can fix a huge amount of CO2 and has low effects on ecological systems. Storing CO2 in ocean includes such methods as storing it in deep oceans; storing it in deep ocean beds; dissolving it into sea water; neutralizing it with calcium carbonates; and precipitating it as dry ice. Japan, disposing CO2 in these ways, may create international problems. Separation of CO2 may use a chemical absorption process as a superior method. Other processes discussed include a physical adsorption method and a membrane separation method. A useful method for CO2 fixation using marine organisms is fixation using coral reefs. This process will require an overall study including circulation of phosphorus and nitrogen. Marine organisms may include planktons and algae. CO2 fixation using land plants may be able to fix one trillion and 8 hundred billion tons of CO2 as converted to carbon. This process would require forest protection, prevention of desertification, and tree planting. Discussions are being given also on improving power generation cycles, recovering CO2 from automotive exhausts, and backfilling carbons into ground by means of photosynthesis. 23 refs., 7 figs., 1 tab.

  15. Precursory diffuse CO2 emission signature of the 2011 El Hierro submarine eruption, Canary Islands

    Science.gov (United States)

    Pérez, N. M.; Padilla, G. D.; Padrón, E.; Hernández, P. A.; Melián, G. V.; Barrancos, J.; Dionis, S.; Rodríguez, F.; Nolasco, D.; Calvo, D.; Hernández, I.; Peraza, M. D.

    2012-04-01

    El Hierro is the youngest and southernmost island of the Canarian archipelago and represents the summit of a volcanic shield elevating from the surrounding seafloor at depth of 4000 m to up to 1501 m above sea level. The island is believed to be near the present hotspot location in the Canaries with the oldest subaerial rocks dated at 1.12 Ma. The subaerial parts of the El Hierro rift zones (NE, NW and S Ridges) are characterized by tightly aligned dyke complexes with clusters of cinder cones as their surface expressions. Since 16 July, an anomalous seismicity at El Hierro Island was recorded by IGN seismic network. Volcanic tremor started at 05:15 on 10 October, followed on the afternoon of 12 October by a green discolouration of seawater, strong bubbling and degassing, and abundant bombs on a decimetre scale found floating on the ocean surface offshore, southwest of La Restinga village, indicating the occurrence of a submarine volcanic eruption at approximately 2 km far the coast line of La Restinga. Further episodes have occurred during November, December 2011 and January 2012, with turbulent water, foam rings, and volcanic material again reaching the sea surface. In order to improve the volcanic surveillance program of El Hierro Island and to provide a multidisciplinary approach, a continuous geochemical station to measure CO2 efflux was installed on September 2003 in Llanos de Guillen, the interception center of the three volcanic-rift zones of the island, with the aim of detecting changes in the diffuse emission of CO2 related to the seismic or volcanic activity. The station measures on an hourly basis the CO2 and H2S efflux, the CO2 and H2S air concentrations, the soil water content and temperature and the atmospheric parameters: wind speed and direction, air temperature and humidity and barometric pressure. The meteorological parameters together with the air CO2 concentration are measured 1 m above the ground and the soil water content and soil temperature

  16. Fingerprinting captured CO2 using natural tracers: Determining CO2 fate and proving ownership

    Science.gov (United States)

    Flude, Stephanie; Gilfillan, Stuart; Johnston, Gareth; Stuart, Finlay; Haszeldine, Stuart

    2016-04-01

    In the long term, captured CO2 will most likely be stored in large saline formations and it is highly likely that CO2 from multiple operators will be injected into a single saline formation. Understanding CO2 behavior within the reservoir is vital for making operational decisions and often uses geochemical techniques. Furthermore, in the event of a CO2 leak, being able to identify the owner of the CO2 is of vital importance in terms of liability and remediation. Addition of geochemical tracers to the CO2 stream is an effective way of tagging the CO2 from different power stations, but may become prohibitively expensive at large scale storage sites. Here we present results from a project assessing whether the natural isotopic composition (C, O and noble gas isotopes) of captured CO2 is sufficient to distinguish CO2 captured using different technologies and from different fuel sources, from likely baseline conditions. Results include analytical measurements of CO2 captured from a number of different CO2 capture plants and a comprehensive literature review of the known and hypothetical isotopic compositions of captured CO2 and baseline conditions. Key findings from the literature review suggest that the carbon isotope composition will be most strongly controlled by that of the feedstock, but significant fractionation is possible during the capture process; oxygen isotopes are likely to be controlled by the isotopic composition of any water used in either the industrial process or the capture technology; and noble gases concentrations will likely be controlled by the capture technique employed. Preliminary analytical results are in agreement with these predictions. Comparison with summaries of likely storage reservoir baseline and shallow or surface leakage reservoir baseline data suggests that C-isotopes are likely to be valuable tracers of CO2 in the storage reservoir, while noble gases may be particularly valuable as tracers of potential leakage.

  17. Atmospheric inversion of the surface CO2 flux with 13CO2 constraint

    Science.gov (United States)

    Chen, J. M.; Mo, G.; Deng, F.

    2013-10-01

    Observations of 13CO2 at 73 sites compiled in the GLOBALVIEW database are used for an additional constraint in a global atmospheric inversion of the surface CO2 flux using CO2 observations at 210 sites for the 2002-2004 period for 39 land regions and 11 ocean regions. This constraint is implemented using the 13CO2/CO2 flux ratio modeled with a terrestrial ecosystem model and an ocean model. These models simulate 13CO2 discrimination rates of terrestrial photosynthesis and respiration and ocean-atmosphere diffusion processes. In both models, the 13CO2 disequilibrium between fluxes to and from the atmosphere is considered due to the historical change in atmospheric 13CO2 concentration. For the 2002-2004 period, the 13CO2 constraint on the inversion increases the total land carbon sink from 3.40 to 3.70 Pg C yr-1 and decreases the total oceanic carbon sink from 1.48 to 1.12 Pg C yr-1. The largest changes occur in tropical areas: a considerable decrease in the carbon source in the Amazon forest, and this decrease is mostly compensated by increases in the ocean region immediately west of the Amazon and the southeast Asian land region. Our further investigation through different treatments of the 13CO2/CO2 flux ratio used in the inversion suggests that variable spatial distributions of the 13CO2 isotopic discrimination rate simulated by the models over land and ocean have considerable impacts on the spatial distribution of the inverted CO2 flux over land and the inversion results are not sensitive to errors in the estimated disequilibria over land and ocean.

  18. Diffusive Soil Degassing of Radon and Carbon Dioxide at Ilopango Caldera, El Salvador, Central America

    Science.gov (United States)

    Ransom, L.; Lopez, D. L.; Hernandez, P.

    2001-12-01

    Ilopango Caldera lies 10 Km east of San Salvador, El Salvador and holds Ilopango Lake, the largest body of fresh water in El Salvador. There is currently no observed fumarolic activity within the caldera system. However, the last eruption occurred in 1880. In November - December, 1999, radon gas concentrations (pCi/l) were measured using a Pylon AB5 radon monitor, and flux of CO2 (g/m2/day) was determined using the accumulation chamber method at 106 sampling stations around the lake, along and across the caldera walls. Gas samples were also collected to determine the isotopic composition of C in CO2. CO2 fluxes did not show high values characteristic of other volcanic systems, values ranged from 0.7 to 9.2 g/m2/day with an average value of 3.9. These values are similar to the low values of the background population observed in nearby San Salvador volcano. Highest values are observed to the east and west of the lake. Isotopic values for C in soil gases do not show an important magmatic component. Radon concentrations present three distinct populations with the highest values occurring to the southwest. Thoron concentrations are higher close to the caldera walls than inside the caldera due to the possible higher rock fracturing in that region. Measurements taken in March 2001, after the January 13 and February 13, 2001 earthquakes did not show significant variations in CO2 fluxes. However, radon concentrations varied due to the high seismicity that lasted several months after these earthquakes. These results suggest that the magmatic system of Ilopango Caldera is not emitting high fluxes of CO2 to the atmosphere throughout the caldera soils. Subaquatic emissions of CO2 have not been evaluated. However, subaquatic hydrothermal discharges have not been identified at this calderic lake.

  19. CO2-Water-Rock Wettability: Variability, Influencing Factors, and Implications for CO2 Geostorage.

    Science.gov (United States)

    Iglauer, Stefan

    2017-05-16

    Carbon geosequestration (CGS) has been identified as a key technology to reduce anthropogenic greenhouse gas emissions and thus significantly mitigate climate change. In CGS, CO 2 is captured from large point-source emitters (e.g., coal fired power stations), purified, and injected deep underground into geological formations for disposal. However, the CO 2 has a lower density than the resident formation brine and thus migrates upward due to buoyancy forces. To prevent the CO 2 from leaking back to the surface, four trapping mechanisms are used: (1) structural trapping (where a tight caprock acts as a seal barrier through which the CO 2 cannot percolate), (2) residual trapping (where the CO 2 plume is split into many micrometer-sized bubbles, which are immobilized by capillary forces in the pore network of the rock), (3) dissolution trapping (where CO 2 dissolves in the formation brine and sinks deep into the reservoir due to a slight increase in brine density), and (4) mineral trapping (where the CO 2 introduced into the subsurface chemically reacts with the formation brine or reservoir rock or both to form solid precipitates). The efficiency of these trapping mechanisms and the movement of CO 2 through the rock are strongly influenced by the CO 2 -brine-rock wettability (mainly due to the small capillary-like pores in the rock which form a complex network), and it is thus of key importance to rigorously understand CO 2 -wettability. In this context, a substantial number of experiments have been conducted from which several conclusions can be drawn: of prime importance is the rock surface chemistry, and hydrophilic surfaces are water-wet while hydrophobic surfaces are CO 2 -wet. Note that CO 2 -wet surfaces dramatically reduce CO 2 storage capacities. Furthermore, increasing pressure, salinity, or dissolved ion valency increases CO 2 -wettability, while the effect of temperature is not well understood. Indeed theoretical understanding of CO 2 -wettability and the

  20. A cost effective CO2 strategy

    DEFF Research Database (Denmark)

    , a scenario-part and a cost-benefit part. Air and sea modes are not analyzed. The model adopts a bottom-up approach to allow a detailed assessment of transport policy measures. Four generic areas of intervention were identified and the likely effect on CO2 emissions, socioeconomic efficiency and other...... are evaluated according to CO2 reduction potential and according to the ‘shadow price’ on a reduction of one ton CO2. The shadow price reflects the costs (and benefits) of the different measures. Comparing the measures it is possible to identify cost effective measures, but these measures are not necessarily...... by the Ministry of Transport, with the Technical University of Denmark as one of the main contributors. The CO2-strategy was to be based on the principle of cost-effectiveness. A model was set up to assist in the assessment. The model consists of a projection of CO2-emissions from road and rail modes from 2020...

  1. Rangeland -- plant response to elevated CO2

    International Nuclear Information System (INIS)

    Owensby, C.E.; Coyne, P.I.; Ham, J.M.; Parton, W.; Rice, C.; Auen, L.M.; Adam, N.

    1993-01-01

    Plots of a tallgrass prairie ecosystem were exposed to ambient and twice-ambient CO 2 concentrations in open-top chambers and compared to unchambered ambient CO 2 plots during the entire growing season from 1989 through 1992. Relative root production among treatments was estimated using root ingrowth bags which remained in place throughout the growing season. Latent heat flux was simulated with and without water stress. Botanical composition was estimated annuallyin all treatments. Open-top chambers appeared to reduce latent heat flux and increase water use efficiency similar to elevated CO 2 when water stress was not severe, but under severe water stress, chamber effect on water use efficiency was limited. In natural ecosystems with periodic moisture stress, increased water use efficiency under elevated CO 2 apparently would have a greater impact on productivity than photosynthetic pathway. Root ingrowth biomass was greater in 1990 and 1991 on elevated CO 2 plots compared to ambient or chambered-ambient plots. In 1992, there was no difference in root ingrowth biomass among treatments

  2. Economic efficiency of CO2 reduction programs

    International Nuclear Information System (INIS)

    Tahvonen, O.; Storch, H. von; Storch, J. von

    1993-01-01

    A highly simplified time-dependent low-dimensional system has been designed to describe conceptually the interaction of climate and economy. Enhanced emission of carbon dioxide (CO 2 ) is understood as the agent that not only favors instantaneous consumption but also causes unfavorable climate changes at a later time. The problem of balancing these two counterproductive effects of CO 2 emissions on a finite time horizon is considered. The climate system is represented by just two parameters, namely a globally averaged near-surface air-temperature and a globally averaged troposheric CO 2 concentration. The costs of abating CO 2 emissions are monitored by a function which depends quadratically on the percentage reduction of emission compared to an 'uncontrolled emission' scenario. Parameters are fitted to historical climate data and to estimates from studies of CO 2 abatement costs. Two optimization approaches, which differ from earlier attempts to describe the interaction of economy and climate, are discussed. In the 'cost oriented' strategy an optimal emission path is identified which balances the abatement costs and explicitly formulated damage costs. These damage costs, whose estimates are very uncertain, are hypothesized to be a linear function of the time-derivative of temperature. In the 'target oriented' strategy an emission path is chosen so that the abatement costs are minimal while certain restrictions on the terminal temperature and concentration change are met. (orig.)

  3. Eruption Depths, Magma Storage and Magma Degassing at Sumisu Caldera, Izu-Bonin Arc: Evidence from Glasses and Melt Inclusions

    Science.gov (United States)

    Johnson, E. R.

    2015-12-01

    Island arc volcanoes can become submarine during cataclysmal caldera collapse. The passage of a volcanic vent from atmospheric to under water environment involves complex modifications of the eruption style and subsequent transport of the pyroclasts. Here, we use FTIR measurements of the volatile contents of glass and melt inclusions in the juvenile pumice clasts in the Sumisu basin and its surroundings (Izu-Bonin arc) to investigate changes in eruption depths, magma storage and degassing over time. This study is based on legacy cores from ODP 126, where numerous unconsolidated (250 m), massive to normally graded pumice lapilli-tuffs were recovered over four cores (788C, 790A, 790B and 791A). Glass and clast geochemistry indicate the submarine Sumisu caldera as the source of several of these pumice lapilli-tuffs. Glass chips and melt inclusions from these samples were analyzed using FTIR for H2O and CO2 contents. Glass chips record variable H2O contents; most chips contain 0.6-1.6 wt% H2O, corresponding to eruption depths of 320-2100 mbsl. Variations in glass H2O and pressure estimates suggest that edifice collapse occurred prior-to or during eruption of the oldest of these samples, and that the edifice may have subsequently grown over time. Sanidine-hosted melt inclusions from two units record variably degassed but H2O-rich melts (1.1-5.6 wt% H2O). The lowest H2O contents overlap with glass chips, consistent with degassing and crystallization of melts until eruption, and the highest H2O contents suggest that large amounts of degassing accompanied likely explosive eruptions. Most inclusions, from both units, contain 2-4 wt% H2O, which further indicates that the magmas crystallized at pressures of ~50-100 MPa, or depths ~400-2800 m below the seafloor. Further glass and melt inclusion analyses, including major element compositions, will elucidate changes in magma storage, degassing and evolution over time.

  4. CO2-Switchable Membranes Prepared by Immobilization of CO2-Breathing Microgels.

    Science.gov (United States)

    Zhang, Qi; Wang, Zhenwu; Lei, Lei; Tang, Jun; Wang, Jianli; Zhu, Shiping

    2017-12-20

    Herein, we report the development of a novel CO 2 -responsive membrane system through immobilization of CO 2 -responsive microgels into commercially available microfiltration membranes using a method of dynamic adsorption. The microgels, prepared from soap-free emulsion polymerization of CO 2 -responsive monomer 2-(diethylamino)ethyl methacrylate (DEA), can be reversibly expanded and shrunken upon CO 2 /N 2 alternation. When incorporated into the membranes, this switching behavior was preserved and further led to transformation between microfiltration and ultrafiltration membranes, as indicated from the dramatic changes on water flux and BSA rejection results. This CO 2 -regulated performance switching of membranes was caused by the changes of water transportation channel, as revealed from the dynamic water contact angle tests and SEM observation. This work represents a simple yet versatile strategy for making CO 2 -responsive membranes.

  5. CO2 sensing and CO2 regulation of stomatal conductance: advances and open questions

    Science.gov (United States)

    Engineer, Cawas; Hashimoto-Sugimoto, Mimi; Negi, Juntaro; Israelsson-Nordstrom, Maria; Azoulay-Shemer, Tamar; Rappel, Wouter-Jan; Iba, Koh; Schroeder, Julian

    2015-01-01

    Guard cells form epidermal stomatal gas exchange valves in plants and regulate the aperture of stomatal pores in response to changes in the carbon dioxide (CO2) concentration in leaves. Moreover, the development of stomata is repressed by elevated CO2 in diverse plant species. Evidence suggests that plants can sense CO2 concentration changes via guard cells and via mesophyll tissues in mediating stomatal movements. We review new discoveries and open questions on mechanisms mediating CO2-regulated stomatal movements and CO2 modulation of stomatal development, which together function in CO2-regulation of stomatal conductance and gas exchange in plants. Research in this area is timely in light of the necessity of selecting and developing crop cultivars which perform better in a shifting climate. PMID:26482956

  6. Flow reduction due to degassing and redissolution phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Doughty, C. [Lawrence Berkeley Laboratory, Berkeley, CA (United States)

    1995-03-01

    At the Stripa mine in Sweden, flow and transport experiments in a water-saturated fractured granite were conducted to investigate techniques for site characterization for a geologic nuclear waste repository. In the Simulated Drift Experiment, measured water inflow to an excavated drift with pressure held at 1 bar was only 1/9th the value expected based on inflow to boreholes with pressure held at 2.7 bars. Several physical and chemical mechanisms were hypothesized to be responsible for this reduction in flow. One possibility is that significant degassing of dissolved nitrogen takes place between 2.7 and 1 bars, credating a two-phase regime with an accompanying decrease in fluid mobility, resulting in a decrease in flow to the drift. To investigate this process, theoretical studies on degassing and redissolution phenomena have been carried out, beginning with an idealized model which yields a simple analytical solution, then relaxing some of the simplifying assumptions and using TOUGH2 to study the phenomena numerically. In conjunction with these theoretical studies, laboratory experiments on flow and degassing in transparent fracture replicas are being carried out, and are being used to check the modeling approach. We need to develop a fundamental understanding of degassing and redissolution in particular and two-phase flow phenomena in general for flow in fractures and fracture networks, in order to successfully model conditions around a nuclear waste repository, where long time and large space scales may preclude conclusive field experiments.

  7. Reactions between olivine and CO2-rich seawater at 300 °C: Implications for H2 generation and CO2 sequestration on the early Earth

    Directory of Open Access Journals (Sweden)

    Hisahiro Ueda

    2017-03-01

    Full Text Available To understand the influence of fluid CO2 on ultramafic rock-hosted seafloor hydrothermal systems on the early Earth, we monitored the reaction between San Carlos olivine and a CO2-rich NaCl fluid at 300 °C and 500 bars. During the experiments, the total carbonic acid concentration (ΣCO2 in the fluid decreased from approximately 65 to 9 mmol/kg. Carbonate minerals, magnesite, and subordinate amount of dolomite were formed via the water-rock interaction. The H2 concentration in the fluid reached approximately 39 mmol/kg within 2736 h, which is relatively lower than the concentration generated by the reaction between olivine and a CO2-free NaCl solution at the same temperature. As seen in previous hydrothermal experiments using komatiite, ferrous iron incorporation into Mg-bearing carbonate minerals likely limited iron oxidation in the fluids and the resulting H2 generation during the olivine alteration. Considering carbonate mineralogy over the temperature range of natural hydrothermal fields, H2 generation is likely suppressed at temperatures below approximately 300 °C due to the formation of the Mg-bearing carbonates. Nevertheless, H2 concentration in fluid at 300 °C could be still high due to the temperature dependency of magnetite stability in ultramafic systems. Moreover, the Mg-bearing carbonates may play a key role in the ocean-atmosphere system on the early Earth. Recent studies suggest that the subduction of carbonated ultramafic rocks may transport surface CO2 species into the deep mantle. This process may have reduced the huge initial amount of CO2 on the surface of the early Earth. Our approximate calculations demonstrate that the subduction of the Mg-bearing carbonates formed in komatiite likely played a crucial role as one of the CO2 carriers from the surface to the deep mantle, even in hot subduction zones.

  8. Genesis of fumarolic emissions as inferred by isotope mass balances: CO 2 and water at Vulcano Island, Italy

    Science.gov (United States)

    Paonita, A.; Favara, R.; Nuccio, P. M.; Sortino, F.

    2002-03-01

    We have developed a quantitative model of CO2 and H2O isotopic mixing between magmatic and hydrothermal gases for the fumarolic emissions of the La Fossa crater (Vulcano Island, Italy). On the basis of isotope balance equations, the model takes into account the isotope equilibrium between H2O and CO2 and extends the recent model of chemical and energy two-end-member mixing by Nuccio et al. (1999). As a result, the H2O and CO2 content and the δD, δ18O, and δ13C isotope compositions for both magmatic and hydrothermal end-members have been assessed. Low contributions of meteoric steam, added at a shallow depth, have been also recognized and quantified in the fumaroles throughout the period from 1988 to 1998. Nonequilibrium oxygen isotope exchange also seems to be occurring between ascending gases and wall rocks along some fumarolic conduits. The δ13CCO2 of the magmatic gases varies around -3 to 1‰ vs. Peedee belemnite (PDB), following a perfect synchronism with the variations of the CO2 concentration in the magmatic gases. This suggests a process of isotope fractionation because of vapor exsolution caused by magma depressurization. The hydrogen isotopes in the magmatic gases (-1 to -‰ vs. standard mean ocean water [SMOW]), as well as the above δ13CCO2 value, are coherent with a convergent tectonic setting of magma generation, where the local mantle is widely contaminated by fluids released from the subducted slab. Magma contamination in the crust probably amplifies this effect. The computed isotope composition of carbon and hydrogen in the hydrothermal vapors has been used to calculate the δD and δ13C of the entire hydrothermal system, including mixed H2O-CO2 vapor, liquid water, and dissolved carbon. We have computed values of about 10‰ vs. SMOW for water and -2 to -6.5‰ vs. PDB for CO2. On these grounds, we think that Mediterranean marine water (δDH2O ≈ 10‰) feeds the hydrothermal system. It infiltrates at depth throughout the local rocks

  9. Evasion of CO2 injected into the ocean in the context of CO2 stabilization

    International Nuclear Information System (INIS)

    Kheshgi, Haroon S.

    2004-01-01

    The eventual evasion of injected CO 2 to the atmosphere is one consideration when assessing deep-sea disposal of CO 2 as a potential response option to climate change concerns. Evasion estimated using an ocean carbon cycle model is compared to long-term trajectories for future CO 2 emissions, including illustrative cases leading to stabilization of CO 2 concentration at various levels. Modeled residence time for CO 2 injected into the deep ocean exceeds the 100-year time-scale usually considered in scenarios for future emissions, and the potential impacts of climate change. Illustrative cases leading monotonically to constant CO 2 concentration have been highlighted by the Intergovernmental Panel on Climate Change to give guidance on possible timing of emission reductions that may be required to stabilize greenhouse gas concentrations at various levels. For stabilization cases considered, significant modeled evasion does not occur until long after CO 2 emissions have reached a maximum and begun to decline. Illustrative cases can also lead to a maximum in CO 2 concentration followed by a decline to slowly decreasing concentrations. In such cases, future injection of emissions into the deep ocean leads to lower maximum CO 2 concentration, with less effect on concentration later on in time

  10. Effect of Uncertainties in CO2 Property Databases on the S-CO2 Compressor Performance

    International Nuclear Information System (INIS)

    Lee, Je Kyoung; Lee, Jeong Ik; Ahn, Yoonhan; Kim, Seong Gu; Cha, Je Eun

    2013-01-01

    Various S-CO 2 Brayton cycle experiment facilities are on the state of construction or operation for demonstration of the technology. However, during the data analysis, S-CO 2 property databases are widely used to predict the performance and characteristics of S-CO 2 Brayton cycle. Thus, a reliable property database is very important before any experiment data analyses or calculation. In this paper, deviation of two different property databases which are widely used for the data analysis will be identified by using three selected properties for comparison, C p , density and enthalpy. Furthermore, effect of above mentioned deviation on the analysis of test data will be briefly discussed. From this deviation, results of the test data analysis can have critical error. As the S-CO 2 Brayton cycle researcher knows, CO 2 near the critical point has dramatic change on thermodynamic properties. Thus, it is true that a potential error source of property prediction exists in CO 2 properties near the critical point. During an experiment data analysis with the S-CO 2 Brayton cycle experiment facility, thermodynamic properties are always involved to predict the component performance and characteristics. Thus, construction or defining of precise CO 2 property database should be carried out to develop Korean S-CO 2 Brayton cycle technology

  11. Surface CO2 leakage during the first shallow subsurface CO2 release experiment

    OpenAIRE

    Lewicki, J.L.; Oldenburg, C.; Dobeck, L.; Spangler, L.

    2008-01-01

    A new field facility was used to study CO2 migration processes and test techniques to detect and quantify potential CO2 leakage from geologic storage sites. For 10 days starting 9 July 2007, and for seven days starting 5 August 2007, 0.1 and 0.3 t CO2 d-1, respectively, were released from a ~;100-m long, sub-water table (~;2.5-m depth) horizontal well. The spatio-temporal evolution of leakage was mapped through repeated grid measurements of soil CO2 flux (FCO2). The surface leakage onset...

  12. Groundwater degassing in fractured rock: Modelling and data comparison

    Energy Technology Data Exchange (ETDEWEB)

    Jarsjoe, J.; Destouni, G. [Royal Inst. of Tech., Stockholm (Sweden). Water Resources Engineering

    1998-11-01

    Dissolved gas may be released from deep groundwater in the vicinity of open boreholes and drifts, where the water pressures are relatively low. Degassing of groundwater may influence observations of hydraulic conditions made in drifts, interpretation of experiments performed close to drifts, and buffer mass and backfill performance, particularly during emplacement and repository closure. Under certain conditions, considerable fracture inflow and transmissivity reductions have been observed during degassing experiments in the field and in the laboratory; such reductions affect the outcome and interpretation of both hydraulic and tracer tests. We develop models for the estimation of the resulting degree of fracture gas saturation and the associated transmissivity reduction due to groundwater degassing in fractured rock. Derived expressions for bubble trapping probability show that fracture aperture variability and correlation length influence the conditions for capillary bubble trapping and gas accumulation. The laboratory observations of bubble trapping in an Aespoe fracture replica are consistent with the prediction of a relatively high probability of bubble trapping in this fracture. The prediction was based on the measured aperture distribution of the Aespoe fracture and the applied hydraulic gradient. Results also show that the conceptualisation of gas and water occupancy in a fracture greatly influences model predictions of gas saturation and relative transmissivity. Images from laboratory degassing experiments indicate that tight apertures are completely filled with water, whereas both gas and water exist in wider apertures under degassing conditions; implementation of this relation in our model resulted in the best agreement between predictions and laboratory observations. Model predictions for conditions similar to those prevailing in field for single fractures at great depths indicate that degassing effects in boreholes should generally be small, unless the

  13. The idea of global CO2 trade

    International Nuclear Information System (INIS)

    Svendsen, G.T.

    1999-01-01

    The US has been criticized for wanting to earn a fortune on a global CO 2 market. However, compared to the situation without trade and provided that such a market is designed so that it does not pay to cheat, a global CO 2 market may provide the world with an epoch-making means of cost-effective control which can solve future global environmental problems. The economic gains from 'hot air' distributions of permits and CO 2 trade make the system politically attractive to potential participants. For example, vital financial subsidies from the EU to Eastern Europe are to be expected. It will probably not pay to cheat if quotas are renewed periodically by the UN. Cheating countries are then to be excluded from further profitable trade. Also, a periodical renewal of permits makes it possible to tighten target levels in the future

  14. Decoupling of CO2 emissions and GDP

    Directory of Open Access Journals (Sweden)

    Yves Rocha de Salles Lima

    2016-12-01

    Full Text Available The objetive of this work is to analyze the variation of CO2 emissions and GDP per capita throughout the years and identify the possible interaction between them. For this purpose, data from the International Energy Agency was collected on two countries, Brazil and the one with the highest GDP worldwide, the United States. Thus, the results showed that CO2 emissions have been following the country’s economic growth for many years. However, these two indicators have started to decouple in the US in 2007 while in Brazil the same happened in 2011. Furthermore, projections for CO2 emissions are made until 2040, considering 6 probable scenarios. These projections showed that even if the oil price decreases, the emissions will not be significantly affected as long as the economic growth does not decelerate.

  15. CO2 utilization: Developments in conversion processes

    Directory of Open Access Journals (Sweden)

    Erdogan Alper

    2017-03-01

    The potential utilization of CO2, captured at power plants, should also been taken into consideration for sustainability. This CO2 source, which is potentially a raw material for the chemical industry, will be available at sufficient quality and at gigantic quantity upon realization of on-going tangible capture projects. Products resulting from carboxylation reactions are obvious conversions. In addition, provided that enough supply of energy from non-fossil resources, such as solar [1], is ensured, CO2 reduction reactions can produce several valuable commodity chemicals including multi-carbon compounds, such as ethylene and acrylic acid, in addition to C1 chemicals and polymers. Presently, there are only few developing technologies which can find industrial applications. Therefore, there is a need for concerted research in order to assess the viability of these promising exploratory technologies rationally.

  16. Crop responses to CO2 enrichment

    International Nuclear Information System (INIS)

    Rogers, H.H.; Dahlman, R.C.

    1993-01-01

    Carbon dioxide is rising in the global atmosphere, and this increase can be expected to continue into the foreseeable future. This compound is an essential input to plant life. Crop function is affected across all scales from biochemical to agroecosystem. An array of methods (leaf cuvettes, field chambers, free-air release systems) are available for experimental studies of CO 2 effects. Carbon dioxide enrichment of the air in which crops grow usually stimulates their growth and yield. Plant structure and physiology are markedly altered. Interactions between CO 2 and environmental factors that influence plants are known to occur. Implications for crop growth and yield are enormous. Strategies designed to assure future global food security must include a consideration of crop responses to elevated atmospheric CO 2 . 137 refs., 4 figs., 4 tabs

  17. Waste cleaning using CO2-acid microemulsion

    International Nuclear Information System (INIS)

    Park, Kwangheon; Sung, Jinhyun; Koh, Moonsung; Ju, Minsu

    2011-01-01

    Frequently we need to decontaminate radioactive wastes for volume reduction purposes. Metallic contaminants in wastes can be removed by dissolution to acid; however, this process produces a large amount of liquid acid waste. To reduce this 2ndary liquid waste, we suggest CO 2 -acid emulsion in removing metallic contaminants. Micro- and macro-emulsion of acid in liquid/supercritical CO 2 were successfully made. The formation region of microemulsion (water or acid in CO 2 ) was measured, and stability of the microemulsion was analyzed with respect to surfactant types. We applied micro- and macro-emulsion containing acid to the decontamination of radioactive metallic parts contaminated on the surface. The cleaning methods of micro- and macro-emulsion seemed better compared to the conventional acid cleaning. Moreover, these methods produce very small amount of secondary wastes. (author)

  18. Direct electroreduction of CO2 into hydrocarbon

    International Nuclear Information System (INIS)

    Winea, Gauthier; Ledoux, Marc-Jacques; Pham-Huu, Cuong; Gangeri, Miriam; Perathoner, Siglinda; Centi, Gabriele

    2006-01-01

    A lot of methods exist to directly reduce carbon dioxide into hydrocarbons: the photoelectrochemical process is certainly the most interesting, essentially due to the similarities with photosynthesis. As the human activities produce a great quantity of CO 2 , this one can then be considered as an infinite source of carbon. The products of this reaction are identical to those obtained during a Fischer-Tropsch reaction, that is to say hydrocarbons, alcohols and carboxylic acids. These works deal with the electrochemical reduction of CO 2 in standard conditions of temperature and pressure. The photochemical part has been replaced by a current generator as electrons source and a KHCO 3 aqueous solution as protons source. The first catalytic results clearly show that it is possible to reduce CO 2 into light hydrocarbons, typically from C1 to C9. (O.M.)

  19. Cutting weeds with a CO2 laser

    DEFF Research Database (Denmark)

    Heisel, T.; Schou, Jørgen; Christensen, S.

    2001-01-01

    Stems of Chenopodium album. and Sinapis arvensis. and leaves of Lolium perenne. were cut with a CO2 laser or with a pair of scissors. Treatments were carried out on greenhouse-grown pot plants at three different growth stages and at two heights. Plant dry matter was measured 2 to 5 weeks after...... treatment. The relationship between dry weight and laser energy was analysed using a non-linear dose-response regression model. The regression parameters differed significantly between the weed species. At all growth stages and heights S. arvensis was more difficult to cut with a CO2 laser than C. album....... When stems were cut below the meristems, 0.9 and 2.3 J mm(-1) of CO2 laser energy dose was sufficient to reduce by 90% the biomass of C. album and S. arvensis respectively. Regrowth appeared when dicotyledonous plant stems were cut above meristems, indicating that it is important to cut close...

  20. Assessment of CO2 free energy options

    International Nuclear Information System (INIS)

    Cavlina, N.; Raseta, D.; Matutinovic, I.

    2014-01-01

    One of the European Union climate and energy targets is to significantly reduce CO 2 emissions, at least 20% by 2020, compared to 1990. In the power industry, most popular solution is use of solar and wind power. Since their production varies significantly during the day, for the purpose of base-load production they can be paired with gas-fired power plant. Other possible CO 2 -free solution is nuclear power plant. This article compared predicted cost of energy production for newly built nuclear power plant and newly built combination of wind or solar and gas-fired power plant. Comparison was done using Levelized Unit of Energy Cost (LUEC). Calculations were performed using the Monte Carlo method. For input parameters that have biggest uncertainty (gas cost, CO 2 emission fee) those uncertainties were addressed not only through probability distribution around predicted value, but also through different scenarios. Power plants were compared based on their economic lifetime. (authors)

  1. The ATLAS IBL CO2 Cooling System

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00237783; The ATLAS collaboration; Zwalinski, L.; Bortolin, C.; Vogt, S.; Godlewski, J.; Crespo-Lopez, O.; Van Overbeek, M.; Blaszcyk, T.

    2017-01-01

    The ATLAS Pixel detector has been equipped with an extra B-layer in the space obtained by a reduced beam pipe. This new pixel detector called the ATLAS Insertable B-Layer (IBL) is installed in 2014 and is operational in the current ATLAS data taking. The IBL detector is cooled with evaporative CO2 and is the first of its kind in ATLAS. The ATLAS IBL CO2 cooling system is designed for lower temperature operation (<-35⁰C) than the previous developed CO2 cooling systems in High Energy Physics experiments. The cold temperatures are required to protect the pixel sensors for the high expected radiation dose up to 550 fb^-1 integrated luminosity.

  2. Novel concepts for CO2 capture

    International Nuclear Information System (INIS)

    Dijkstra, J.W.; Jansen, D.

    2004-01-01

    This paper describes the possibilities for power generation with CO 2 capture using envisaged key technologies: gas turbines, membranes and solid oxide fuel cells (SOFCs). First, the underlying programs in the Netherlands and at ECN are introduced. Then the key technologies are introduced, and concepts using these technologies are discussed. A literature overview of systems for power generation with fuel cells in combination with CO 2 capture is presented. Then a novel concept is introduced. This concept uses a water gas shift membrane reactor to convert the CO and H 2 in the SOFC anode off-gas to gain a CO 2 rich stream, which can be used for sequestration without elaborate treatment. Several implementation schemes of the technique are discussed such as atmospheric systems and hybrid SOFC-GT systems

  3. Equilibrium Solubility of CO2 in Alkanolamines

    DEFF Research Database (Denmark)

    Waseem Arshad, Muhammad; Fosbøl, Philip Loldrup; von Solms, Nicolas

    2014-01-01

    Equilibrium solubility of CO2 were measured in aqueous solutions of Monoethanolamine (MEA) and N,N-diethylethanolamine(DEEA). Equilibrium cells are generally used for these measurements. In this study, the equilibrium data were measured from the calorimetry. For this purpose a reaction calorimeter...... (model CPA 122 from ChemiSens AB, Sweden) was used. The advantage of this method is being the measurement of both heats of absorption and equilibrium solubility data of CO2 at the same time. The measurements were performed for 30 mass % MEA and 5M DEEA solutions as a function of CO2 loading at three...... different temperatures 40, 80 and 120 ºC. The measured 30 mass % MEA and 5M DEEA data were compared with the literature data obtained from different equilibrium cells which validated the use of calorimeters for equilibrium solubility measurements....

  4. Vapour discharges on Nevado del Ruiz during the recent activity: Clues on the composition of the deep hydrothermal system and its effects on thermal springs

    Science.gov (United States)

    Federico, Cinzia; Inguaggiato, Salvatore; Chacón, Zoraida; Londoño, John Makario; Gil, Edwing; Alzate, Diego

    2017-10-01

    m asl) is hypothesized to be separated from a high-temperature hydrothermal system. Based on its composition and on literature data on fluid inclusions, we have retrieved the P-T-X conditions of the deep hydrothermal system, as well as its pH and fO2. The vapour feeding Nereidas would separate from a biphasic hydrothermal system characterized by the following parameters: t = 315 °C, P = 15 MPa, NaCl = 10 wt%, CO2 = 5 wt%, and similar proportion between liquid and vapour. Considering also the equilibria involving S-bearing gases and HCl, pH would approach the value of 1.5 while fO2 would correspond to the FeO-Fe2O3 buffer. Chlorine content is estimated at 10,300 mg/l. Changes in the magmatic input into the hydrothermal system could modify its degree of vapourization and/or P-T-X conditions, thus inducing corresponding variations in vapour discharges and thermal waters. These findings, paralleled by contemporary measurements of water flow rates, could give significant clues on risk evaluation.

  5. Mofettes - Investigation of Natural CO2 Springs - Insights and Methods applied

    Science.gov (United States)

    Lübben, A.; Leven, C.

    2014-12-01

    The quantification of carbon dioxide concentrations and fluxes leaking from the subsurface into the atmosphere is highly relevant in several research fields such as climate change, CCS, volcanic activity, or earthquake monitoring. Many of the areas with elevated carbon dioxide degassing pose the problem that under the given situation a systematic investigation of the relevant processes is only possible to a limited extent (e.g. in terms of spatial extent, accessibility, hazardous conditions). The upper Neckar valley in Southwest Germany is a region of enhanced natural subsurface CO2 concentrations and mass fluxes of Tertiary volcanic origin. At the beginning of the twentieth century several companies started industrial mining of CO2. The decreasing productivity of the CO2 springs led to the complete shutdown of the industry in 1995 and the existing boreholes were sealed. However, there are evidences that the reservoir, located in the deposits of the Lower Triassic, started to refill during the last 20 years. The CO2 springs replenished and a variety of different phenomena (e.g. mofettes and perished flora and fauna) indicate the active process of large scale CO2 exhalation. This easy-to-access site serves as a perfect example for a natural analog to a leaky CCS site, including abandoned boreholes and a suitable porous rock reservoir in the subsurface. During extensive field campaigns we applied several monitoring techniques like measurements of soil gas concentrations, mass fluxes, electrical resistivity, as well as soil and atmospheric parameters. The aim was to investigate and quantify mass fluxes and the effect of variations in e.g. temperature, soil moisture on the mass flux intensity. Furthermore, we investigated the effect of the vicinity to a mofette on soil parameters like electrical conductivity and soil CO2 concentrations. In times of a changing climate due to greenhouse gases, regions featuring natural CO2 springs demand to be intensively investigated

  6. Spectroscopic technique for measuring atmospheric CO2

    International Nuclear Information System (INIS)

    Stokes, G.M.; Stokes, R.A.

    1979-01-01

    As part of a continuing effort to identify areas in which astronomical techniques and data may be profitably applied to atmospheric problems, both new and archival solar spectra have been collected to prepare for an analysis of their use for studying the changes of the atmospheric CO 2 burden. This analysis has resulted in the initiation of an observing program using the Fourier Transform Spectrometer (FTS) of the McMath Solar Telescope at Kitt Peak National Observatory (KPNO). This program is generating spectra, the quality of which should not only aid the archival CO 2 study but also lead to analyses of other trace gases

  7. 10 MW Supercritical CO2 Turbine Test

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, Craig

    2014-01-29

    The Supercritical CO2 Turbine Test project was to demonstrate the inherent efficiencies of a supercritical carbon dioxide (s-CO2) power turbine and associated turbomachinery under conditions and at a scale relevant to commercial concentrating solar power (CSP) projects, thereby accelerating the commercial deployment of this new power generation technology. The project involved eight partnering organizations: NREL, Sandia National Laboratories, Echogen Power Systems, Abengoa Solar, University of Wisconsin at Madison, Electric Power Research Institute, Barber-Nichols, and the CSP Program of the U.S. Department of Energy. The multi-year project planned to design, fabricate, and validate an s-CO2 power turbine of nominally 10 MWe that is capable of operation at up to 700°C and operates in a dry-cooled test loop. The project plan consisted of three phases: (1) system design and modeling, (2) fabrication, and (3) testing. The major accomplishments of Phase 1 included: Design of a multistage, axial-flow, s-CO2 power turbine; Design modifications to an existing turbocompressor to provide s-CO2 flow for the test system; Updated equipment and installation costs for the turbomachinery and associated support infrastructure; Development of simulation tools for the test loop itself and for more efficient cycle designs that are of greater commercial interest; Simulation of s-CO2 power cycle integration into molten-nitrate-salt CSP systems indicating a cost benefit of up to 8% in levelized cost of energy; Identification of recuperator cost as a key economic parameter; Corrosion data for multiple alloys at temperatures up to 650ºC in high-pressure CO2 and recommendations for materials-of-construction; and Revised test plan and preliminary operating conditions based on the ongoing tests of related equipment. Phase 1 established that the cost of the facility needed to test the power turbine at its full power and temperature would exceed the planned funding for Phases 2 and 3. Late

  8. 14CO2 fixation pattern of cyanobacteria

    International Nuclear Information System (INIS)

    Erdmann, N.; Schiewer, U.

    1985-01-01

    The 14 CO 2 fixation pattern of three cyanobacteria in the light and dark were studied. Two different chromatographic methods widely used for separating labelled photosynthetic intermediates were compared. After ethanolic extraction, a rather uniform fixation pattern reflecting mainly the β-carboxylation pathway is obtained for all 3 species. Of the intermediates, glucosylglycerol is specific and high citrulline and low malate contents are fairly specific to cyanobacteria. The composition of the 14 CO 2 fixation pattern is hardly affected by changes in temperature or light intensity, but it is severely affected by changes in the water potential of the medium. (author)

  9. Diffuse CO2 fluxes from Santiago and Congro volcanic lakes (São Miguel, Azores archipelago)

    Science.gov (United States)

    Andrade, César; Cruz, José; Viveiros, Fátima; Branco, Rafael

    2017-04-01

    Diffuse CO2 degassing occurring in Santiago and Congro lakes, both located in depressions associated to maars from São Miguel Island (Azores, Portugal), was studied through detailed flux measurements. Four sampling campaigns were developed between 2013 and 2016 in each water body, split by the cold and wet seasons. São Miguel has an area of 744.6 km2, being the largest island of the archipelago. The geology of the island is dominated by three quiescent central volcanoes (Sete Cidades, Fogo and Furnas), linked by volcanic fissural zones (Picos and Congro Fissural Volcanic systems). The oldest volcanic systems of the island are located in its eastern part (Povoação-Nordeste). Santiago lake, with a surface area of 0.26 km2 and a depth of 30.5 m, is located inside a maar crater in the Sete Cidades volcano at an altitude of 355 m. The watershed of the lake has an area of 0.97 km2 and a surface flow estimated as 1.54x10 m3/a. A total of 1612 CO2 flux measurements using the accumulation chamber method were made at Santiago lake, 253 in the first campaign (November 2013), and 462, 475 and 422 in the three other campaigns, respectively, in April 2014, September 2016 and December 2016. The total CO2 flux estimated for this lake varies between 0.4 t d-1 and 0.59 t d-1, for the surveys performed, respectively, in November 2013 and September 2016; higher CO2 outputs of 1.57 and 5.87 t d-1 were calculated for the surveys carried out in April 2014 and December 2016. These higher CO2 emissions were associated with a period without water column stratification. Similarly to Santiago lake, Congro lake is located inside a maar, in the Congro Fissural Volcanic system, and has a surface area of 0.04 km2 with 18.5 m depth and a storage of about 2.4x105 m3/a. The lake, located at an altitude of 420 m, is fed by a watershed with an area of 0.33 km2 and a runoff estimated as about 8x104 m3/a. In Congro lake a total of 713 CO2 flux measurements were performed during four surveys from

  10. The Himalayas of Nepal, a natural laboratory for the search and measurement of CO2 discharge

    Science.gov (United States)

    Girault, Frédéric; Koirala, Bharat P.; Bhattarai, Mukunda; Rajaure, Sudhir; Richon, Patrick; Perrier, Frédéric

    2010-05-01

    Large CO2 flux has been found in the Trisuli Valley, North of Kathmandu, Central Nepal, in 2005. This leakage zone is located in the vicinity of the Syabru-Bensi hot springs, and is characterized by an average flux of CO2 of 6500±1100 g m-2 day-1 over an area of 15 m × 15 m (Perrier et al., Earth and Planetary Science Letters, 2009). The site is also located close to the Main Central Thrust Zone (MCT Zone), one of the large Himalayan thrust, connected at depth to the Main Himalayan Thrust, the main thrust currently accommodating the India-Tibet collision (Bollinger et al., Journal of Geophysical Research, 2004). Isotopic carbon ratios (δ13C) indicate that this CO2 may come from metamorphic reactions at about 15 km of depth (Becker et al., Earth and Planetary Science Letters, 2008; Evans et al., Geochemistry Geophysics Geosystems, 2008). Actually, this zone was originally found because of the large δ13C found in the water of the hot springs suggesting degassing (Evans et al., Geochemistry Geophysics Geosystems, 2008). In 2007, another zone of CO2 discharge was discovered 250 m away from the main Syabru-Bensi hot springs. This new zone, located next to the road and easy to access all over the year, was intensely studied, from the end of 2007 to the beginning of 2009. In this zone, an average value of CO2 flux of 1700±300 g m-2 d-1 was obtained over an area of about 40 m × 10 m. Using CO2 flux data from repeated measurements, similar flux values were observed during the dry winter season and the wet summer period (monsoon) (Girault et al., Journal of Environmental Radioactivity, 2009). Thus, in addition to fundamental issues related to global CO2 balance in orogenic belts and tectonically active zones, these small scale (100-meter) CO2 discharge sites emerge as a potentially useful laboratory for detailed methodological studies of diffusive and advective gas transport. Recently, the search for further gas discharge zones has been carried out using various clues

  11. Mantle to surface degassing of carbon- and sulphur-rich alkaline magma at El Hierro, Canary Islands

    Science.gov (United States)

    Longpré, Marc-Antoine; Stix, John; Klügel, Andreas; Shimizu, Nobumichi

    2017-02-01

    Basaltic volcanoes transfer volatiles from the mantle to the surface of the Earth. The quantification of deep volatile fluxes relies heavily on estimates of the volatile content of primitive magmas, the best archive of which is provided by melt inclusions. Available data from volcanoes producing mafic alkaline lavas in a range of tectonic settings suggest high volatile fluxes, but information remains sparse, particularly for intraplate ocean islands. Here we present measurements of volatile and trace element concentrations, as well as sulphur speciation, in olivine-hosted melt inclusions and matrix glasses from quenched basanite lava balloon samples from the 2011-2012 submarine eruption at El Hierro, Canary Islands. The results reveal remarkably high concentrations of dissolved volatiles and incompatible trace elements in this magma, with ∼80 ppm Nb and up to 3420 ppm CO2, 3.0 wt.% H2O and 5080 ppm S. Reconstructed primitive CO2 contents, considering CO2/Nb systematics and possible CO2 sequestration in shrinkage bubbles, reach weight percent levels, indicating that carbon is a major constituent of Canary Island magmas at depth and that exsolution of a CO2-rich fluid begins in the mantle at pressures in excess of 1 GPa. Correlations between sulphur concentration, sulphur speciation and water content suggest strong reduction of an initially oxidised mantle magma, likely controlled by coupled H2O and S degassing. This late-stage redox change may have triggered sulphide saturation, recorded by globular sulphide inclusions in clinopyroxene and ulvöspinel. The El Hierro basanite thus had a particularly high volatile-carrying capacity and released a minimum of 1.3-2.1 Tg CO2 and 1.8-2.9 Tg S to the environment, causing substantial stress on the local submarine ecosystem. These results highlight the important contribution of alkaline ocean island volcanoes, such as the Canary Islands, to volatile fluxes from the mantle.

  12. Capture and Geological Storage of CO2

    International Nuclear Information System (INIS)

    Kerr, T.; Brockett, S.; Hegan, L.; Barbucci, P.; Tullius, K.; Scott, J.; Otter, N.; Cook, P.; Hill, G.; Dino, R.; Aimard, N.; Giese, R.; Christensen, N.P.; Munier, G.; Paelinck, Ph.; Rayna, L.; Stromberg, L.; Birat, J.P.; Audigane, P.; Loizzo, M.; Arts, R.; Fabriol, H.; Radgen, P.; Hartwell, J.; Wartmann, S.; Drosin, E.; Willnow, K.; Moisan, F.

    2009-01-01

    To build on the growing success of the first two international symposia on emission reduction and CO 2 capture and geological storage, held in Paris in 2005 and again in 2007, IFP, ADEME and BRGM organised a third event on the same topic the 5-6 November 2009. This time, the focus was on the urgency of industrial deployment. Indeed, the IPCC 4. assessment report indicates that the world must achieve a 50 to 85% reduction in CO 2 emissions by 2050 compared to 2000, in order to limit the global temperature increase to around 2 deg. C. Moreover, IPCC stresses that a 'business as usual' scenario could lead to a temperature increase of between 4 deg. C to 7 deg. C across the planet. The symposium was organized in 4 sessions: Session I - Regulatory framework and strategies for enabling CCS deployment: - CCS: international status of political, regulatory and financing issues (Tom Kerr, IEA); - EC regulatory framework (Scott Brockett, European Commission, DG ENV); - Canada's investments towards implementation of CCS in Canada (Larry Hegan, Office of Energy Research and Development - Government of Canada); - A power company perspective (Pietro Barbucci, ENEL); - EC CCS demonstration network (Kai Tullius, European Commission, DG TREN); - Strategies and policies for accelerating global CCS deployment (Jesse Scott, E3G); - The global CCS Institute, a major initiative to facilitate the rapid deployment of CCS (Nick Otter, GCCSI); Session II - From pilot to demonstration projects: - Otway project, Australia (David Hilditch, CO2 CRC); - US regional partnerships (Gerald Hill, Southeast Regional Carbon Sequestration Partnership - SECARB); - CCS activities in Brazil (Rodolfo Dino, Petrobras); - Lessons learnt from Ketzin CO2Sink project in Germany (Ruediger Giese, GFZ); - CO 2 storage - from laboratory to reality (Niels-Peter Christensen, Vattenfall); - Valuation and storage of CO 2 : A global project for carbon management in South-East France (Gilles Munier, Geogreen); Session III

  13. Micropore Formation of [Zn2(Oxac) (Taz)2]·(H2O)2.5 via CO2 Adsorption.

    Science.gov (United States)

    Zubir, Moondra; Hamasaki, Atom; Iiyama, Taku; Ohta, Akira; Ohki, Hiroshi; Ozeki, Sumio

    2017-01-24

    As-synthesized [Zn 2 (Oxac) (Taz) 2 ]·(H 2 O) 2.5 , referred to as ZOTW 2.5 , was prepared from aqueous methanol solutions of Zn 5 (CO 3 ) 2 (OH) 6 and two kinds of ligands of 1,2,4-triazole (Taz) and oxalic acid (Oxac) at 453 K for 12 h. The crystal structure was determined by the Rietveld method. As-synthesized ZOTW 2.5 was pretreated at 383 K and 1 mPa for t pt h, ZOTW x (t pt h). ZOTW x (≥3h) showed a type I adsorption isotherm for N 2 at 77 K having a saturation amount (V s ) of 180 mg/g, but that pretreated shortly showed only 1/10 in V s . CO 2 was adsorbed at 303 K in sigmoid on nonporous ZOTW x (≤2h) and in Langmuir-type on ZOTW x (≥3h) to reach the adsorption amount of 120 mg/g at 700 Torr. N 2 adsorption on ZOTW x (≤2h)deCO 2 , degassed after CO 2 adsorption on ZOTW x (≤2h), was promoted 5-fold from 180 mg/g on ZOTW x (t pt h) and ZOTW x (≥3h)deCO 2 up to ca. 1000 mg/g. The interaction of CO 2 and H 2 O molecules in micropores may lead to a new route for micropore formation.

  14. VOLATILECALC: A silicate melt-H2O-CO2 solution model written in Visual Basic for excel

    Science.gov (United States)

    Newman, S.; Lowenstern, J. B.

    2002-01-01

    We present solution models for the rhyolite-H2O-CO2 and basalt-H2O-CO2 systems at magmatic temperatures and pressures below ~ 5000 bar. The models are coded as macros written in Visual Basic for Applications, for use within MicrosoftR Excel (Office'98 and 2000). The series of macros, entitled VOLATILECALC, can calculate the following: (1) Saturation pressures for silicate melt of known dissolved H2O and CO2 concentrations and the corresponding equilibrium vapor composition; (2) open- and closed-system degassing paths (melt and vapor composition) for depressurizing rhyolitic and basaltic melts; (3) isobaric solubility curves for rhyolitic and basaltic melts; (4) isoplethic solubility curves (constant vapor composition) for rhyolitic and basaltic melts; (5) polybaric solubility curves for the two end members and (6) end member fugacities of H2O and CO2 vapors at magmatic temperatures. The basalt-H2O-CO2 macros in VOLATILECALC are capable of calculating melt-vapor solubility over a range of silicate-melt compositions by using the relationships provided by Dixon (American Mineralogist 82 (1997) 368). The output agrees well with the published solution models and experimental data for silicate melt-vapor systems for pressures below 5000 bar. ?? 2002 Elsevier Science Ltd. All rights reserved.

  15. NiCo2O4 particles with diamond-shaped hexahedron structure for high-performance supercapacitors

    Science.gov (United States)

    Li, Yanfang; Hou, Xiaojuan; Zhang, Zengxing; Hai, Zhenyin; Xu, Hongyan; Cui, Danfeng; Zhuiykov, Serge; Xue, Chenyang

    2018-04-01

    Nickel cobalt oxide (NiCo2O4) particles with a diamond-shaped hexahedral porous sheet structure are successfully synthesized by a facile hydrothermal method, followed by calcination in one step. NiCo2O4-I and NiCo2O4-II particles are prepared using the same method with different contents of urea (CO(NH2)2) and ammonium fluoride (NH4F). The different morphologies of the NiCo2O4-I and NiCo2O4-II particles illustrate that CO(NH2)2 and NH4F play an important role in crystal growth. To verify the influence of NH4F and CO(NH2)2 on the morphology of the NiCo2O4 particles, the theory of crystal growth morphology is analyzed. The electrochemical measurements show that NiCo2O4 particles exhibit a high specific capacitance. At a current density of 1.0 mA cm-2, the mass specific capacitances of the NiCo2O4-I and NiCo2O4-II electrodes are 690.75 and 1710.9 F g-1, respectively, in a 6 M KOH aqueous electrolyte. The specific capacitances of the NiCo2O4-I and NiCo2O4-II electrodes remain ∼95.95% and ∼70.58% of the initial capacitance values after 5000 cycles, respectively. According to the two-electrode test, the NiCo2O4-II//AC asymmetric electrodes exhibited an ultrahigh energy density of 64.67 Wh kg-1 at the power density of 12 kW kg-1, demonstrating its excellent application potential as an electrode material for supercapacitors.

  16. Heterotrophic fixation of CO2 in soil

    Czech Academy of Sciences Publication Activity Database

    Šantrůčková, Hana; Bird, M. I.; Elhottová, Dana; Novák, Jaroslav; Picek, T.; Šimek, Miloslav; Tykva, Richard

    2005-01-01

    Roč. 49, č. 2 (2005), s. 218-225 ISSN 0095-3628 R&D Projects: GA ČR(CZ) GA206/02/1036; GA AV ČR(CZ) IAA6066901 Institutional research plan: CEZ:AV0Z60660521 Keywords : heterotrophic fixation * CO2 * soil Subject RIV: EH - Ecology, Behaviour Impact factor: 2.674, year: 2005

  17. Managing CO2 emissions in Nigeria

    International Nuclear Information System (INIS)

    Obioh, I.B.; Oluwole, A.F.; Akeredolu, F.A.

    1994-01-01

    The energy resources in Nigeria are nearly equally divided between fossil fuels and biofuels. The increasing pressure on them, following expected increased population growth, may lead to substantial emissions of carbon into the atmosphere. Additionally agricultural and forestry management practices in vogue are those related to savannah burning and rotational bush fallow systems, which have been clearly implicated as important sources of CO 2 and trace gases. An integrated model for the prediction of future CO 2 emissions based on fossil fuels and biomass fuels requirements, rates of deforestation and other land-use indices is presented. This is further based on trends in population and economic growth up to the year 2025, with a base year in 1988. A coupled carbon cycle-climate model based on the contribution of CO 2 and other trace gases is established from the proportions of integrated global warming effects for a 20-year averaging time using the product of global warming potential (GWP) and total emissions. An energy-technology inventory approach to optimal resources management is used as a tool for establishing the future scope of reducing the CO 2 emissions through improved fossil fuel energy efficiencies. Scenarios for reduction based on gradual to swift shifts from biomass to fossil and renewable fuels are presented together with expected policy options required to effect them

  18. Detection of 14CO2 in radiotoxicology

    International Nuclear Information System (INIS)

    Simonnet, Francoise; Bocquet, Colette.

    1980-12-01

    14 CO 2 is detected in exhaled air by conversion to Ba 14 CO 3 which is then filtered, dried and weighed. The radioactivity is measured by liquid scintillation counting. The radioactivity is expressed in μCi per litre of exhaled air according to the ICRP recommendations. The detection threshold is well below the values indicated by the ICRP [fr

  19. Stereotactic CO2 laser therapy for hydrocephalus

    Science.gov (United States)

    Kozodoy-Pins, Rebecca L.; Harrington, James A.; Zazanis, George A.; Nosko, Michael G.; Lehman, Richard M.

    1994-05-01

    A new fiber-optic delivery system for CO2 radiation has been used to successfully treat non-communicating hydrocephalus. This system consists of a hollow sapphire waveguide employed in the lumen of a stereotactically-guided neuroendoscope. CO2 gas flows through the bore of the hollow waveguide, creating a path for the laser beam through the cerebrospinal fluid (CSF). This delivery system has the advantages of both visualization and guided CO2 laser radiation without the same 4.3 mm diameter scope. Several patients with hydrocephalus were treated with this new system. The laser was used to create a passage in the floor of the ventricle to allow the flow of CSF from the ventricles to the sub-arachnoid space. Initial postoperative results demonstrated a relief of the clinical symptoms. Long-term results will indicate if this type of therapy will be superior to the use of implanted silicone shunts. Since CO2 laser radiation at 10.6 micrometers is strongly absorbed by the water in tissue and CSF, damage to tissue surrounding the lesion with each laser pulse is limited. The accuracy and safety of this technique may prove it to be an advantageous therapy for obstructive hydrocephalus.

  20. Chilled ammonia process for CO2 capture

    DEFF Research Database (Denmark)

    Darde, Victor Camille Alfred; Thomsen, Kaj; van Well, Willy J. M

    2009-01-01

    The chilled ammonia process absorbs the CO2 at low temperature (2-10 degrees C). The heat of absorption of carbon dioxide by ammonia is significantly lower than for amines. In addition, degradation problems can be avoided and a high carbon dioxide capacity is achieved. Hence, this process shows...

  1. Chilled Ammonia Process for CO2 Capture

    DEFF Research Database (Denmark)

    Darde, Victor Camille Alfred; Thomsen, Kaj; Well, Willy J.M. van

    2010-01-01

    The chilled ammonia process absorbs the CO2 at low temperature (2–10°C). The heat of absorption of carbon dioxide by ammonia is significantly lower than for amines. In addition, degradation problems can be avoided and a high carbon dioxide capacity is achieved. Hence, this process shows good...

  2. The Idea of Global CO2 Trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    1998-01-01

    -effective control which can solve future global environmental problems. The gains from CO2 trade may give vital financial subsidies from the EU to Eastern Europe, for example, and it will probably not pay to cheat if quotas are renewed periodically by the UN. Cheating countries are then to be excluded from further...

  3. Climate change and CO2 emission reductions

    International Nuclear Information System (INIS)

    Ha Duong, M.; Campos, A.S.

    2007-04-01

    This paper presents the results of an opinion poll performed on a representative sample of 1000 persons about their sensitivity to climate change and to environment protection, their knowledge about technologies which are useful for environment protection, their opinion about geological CO 2 sequestration, and technologies to be developed to struggle against climate warming

  4. CO2 emissions of nuclear electricity generation

    International Nuclear Information System (INIS)

    Wissel, Steffen; Mayer-Spohn, Oliver; Fahl, Ulrich; Blesl, Markus; Voss, Alfred

    2008-01-01

    A survey of LCA studies on nuclear electricity generation revealed life cycle CO 2 emissions ranging between 3 g/kWhe to 60 g/kWhe and above. Firstly, this paper points out the discrepancies in studies by estimating the CO 2 emissions of nuclear power generation. Secondly, the paper sets out to provide critical review of future developments of the fuel cycle for light water reactors and illustrates the impact of uncertainties on the specific CO 2 emissions of nuclear electricity generation. Each step in the fuel cycle will be considered and with regard to the CO 2 emissions analysed. Thereby different assumptions and uncertainty levels are determined for the nuclear fuel cycle. With the impacts of low uranium ore grades for mining and milling as well as higher burn-up rates future fuel characteristics are considered. Sensitivity analyses are performed for all fuel processing steps, for different technical specifications of light water reactors as well as for further external frame conditions. (authors)

  5. CO2 effect on porous concrete

    Directory of Open Access Journals (Sweden)

    Sauman, Zdenek

    1974-09-01

    Full Text Available Not availableDebido a la acción del CO2 y de la humedad sobre un hormigón poroso, la tobermorita 11 A se descompone en vaterita, calcita y SÍO2 gel. A causa de la pseudomorfosis, la morfología de los cristales de la fase cementante no sufre cambios notables. La menor resistencia a la compresión se obtuvo después de 30 días de conservación en atmósferas de un 10 y un 30% de CO2. Después de un año de conservación, las resistencias no bajaron más de un 10%. En lo que respecta a la retracción de un hormigón poroso, la principal influencia fue la ejercida por la acción del CO2 y solamente en segundo lugar figura la acción ejercida por la humedad ambiente. Los hormigones porosos expuestos al aire (con su 0,03% de CO2 a h. r. de 50, 70 y 100% sufrieron al cabo de un año una expansión muy ligera.

  6. CO2 capture by Condensed Rotational Separation

    NARCIS (Netherlands)

    Benthum, van R.J.; Kemenade, van H.P.; Brouwers, J.J.H.; Golombok, M.

    2010-01-01

    Condensed Rotational Separation (CRS) technology is a patented method to upgrade gas mixtures. A novel application is thecapture of CO2 from coal-combustion fired power stations: Condensed Contaminant Centrifugal Separation in Coal Combustion(C5sep). CRS involves partial condensation of a gas

  7. CO2 contain of the electric heating

    International Nuclear Information System (INIS)

    Bacher, P.

    2008-02-01

    A recent announcement of the RTE and the ADEME on the CO 2 contain of the electric kW, refuting a 2005 study of EDF and ADEME, perturbed the public opinion and was presented as the proof that the nuclear has no part in the fight against the climatic change. The author aims to set things straight. (A.L.B.)

  8. Towards Verifying National CO2 Emissions

    Science.gov (United States)

    Fung, I. Y.; Wuerth, S. M.; Anderson, J. L.

    2017-12-01

    With the Paris Agreement, nations around the world have pledged their voluntary reductions in future CO2 emissions. Satellite observations of atmospheric CO2 have the potential to verify self-reported emission statistics around the globe. We present a carbon-weather data assimilation system, wherein raw weather observations together with satellite observations of the mixing ratio of column CO2 from the Orbiting Carbon Observatory-2 are assimilated every 6 hours into the NCAR carbon-climate model CAM5 coupled to the Ensemble Kalman Filter of DART. In an OSSE, we reduced the fossil fuel emissions from a country, and estimated the emissions innovations demanded by the atmospheric CO2 observations. The uncertainties in the innovation are analyzed with respect to the uncertainties in the meteorology to determine the significance of the result. The work follows from "On the use of incomplete historical data to infer the present state of the atmosphere" (Charney et al. 1969), which maps the path for continuous data assimilation for weather forecasting and the five decades of progress since.

  9. Ocean acidification: the other CO2 problem.

    Science.gov (United States)

    Doney, Scott C; Fabry, Victoria J; Feely, Richard A; Kleypas, Joan A

    2009-01-01

    Rising atmospheric carbon dioxide (CO2), primarily from human fossil fuel combustion, reduces ocean pH and causes wholesale shifts in seawater carbonate chemistry. The process of ocean acidification is well documented in field data, and the rate will accelerate over this century unless future CO2 emissions are curbed dramatically. Acidification alters seawater chemical speciation and biogeochemical cycles of many elements and compounds. One well-known effect is the lowering of calcium carbonate saturation states, which impacts shell-forming marine organisms from plankton to benthic molluscs, echinoderms, and corals. Many calcifying species exhibit reduced calcification and growth rates in laboratory experiments under high-CO2 conditions. Ocean acidification also causes an increase in carbon fixation rates in some photosynthetic organisms (both calcifying and noncalcifying). The potential for marine organisms to adapt to increasing CO2 and broader implications for ocean ecosystems are not well known; both are high priorities for future research. Although ocean pH has varied in the geological past, paleo-events may be only imperfect analogs to current conditions.

  10. The Idea of Global CO2 Trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    1999-01-01

    -effective control which can solve future global environmental problems. The economic gains from 'hot air' distributions of permits and CO2 trade make the system politically attractive to potential participants. For example, vital financial subsidies from the EU to Eastern Europe are to be expected. It will probably...

  11. CO2 emissions vs. CO2 responsibility: An input-output approach for the Turkish economy

    International Nuclear Information System (INIS)

    Ipek Tunc, G.; Tueruet-Asik, Serap; Akbostanci, Elif

    2007-01-01

    Recently, global warming (greenhouse effect) and its effects have become one of the hottest topics in the world agenda. There have been several international attempts to reduce the negative effects of global warming. The Kyoto Protocol can be cited as the most important agreement which tries to limit the countries' emissions within a time horizon. For this reason, it becomes important to calculate the greenhouse gas emissions of countries. The aim of this study is to estimate the amount of CO 2 -the most important greenhouse gas-emissions, for the Turkish economy. An extended input-output model is estimated by using 1996 data in order to identify the sources of CO 2 emissions and to discuss the share of sectors in total emission. Besides, 'CO 2 responsibility', which takes into account the CO 2 content of imports, is estimated for the Turkish economy. The sectoral CO 2 emissions and CO 2 responsibilities are compared and these two notions are linked to foreign trade volume. One of the main conclusions is that the manufacturing industry has the first place in both of the rankings for CO 2 emissions and CO 2 responsibilities, while agriculture and husbandry has the last place

  12. Literatuuronderzoek CAM-fotosynthese en CO2-bemesting en CO2-bemesting bij bromelia's

    NARCIS (Netherlands)

    Marissen, A.; Warmenhoven, M.G.

    2004-01-01

    De ‘normale’ wijze van CO2-opname gebeurt bij de meeste planten overdag, wanneer er licht is om de opgenomen CO2 door middel van fotosynthese direct om te zetten in suikers. Hiervoor is het nodig dat de huidmondjes overdag open staan, ‘s nachts zijn huidmondjes meestal dicht. Via de huidmondjes gaat

  13. The Li–CO2 battery: a novel method for CO2 capture and utilization

    KAUST Repository

    Xu, Shaomao; Das, Shyamal K.; Archer, Lynden A.

    2013-01-01

    We report a novel primary Li-CO2 battery that consumes pure CO2 gas as its cathode. The battery exhibits a high discharge capacity of around 2500 mA h g-1 at moderate temperatures. At 100 °C the discharge capacity is close to 1000% higher than

  14. Rechargeable Al-CO2 Batteries for Reversible Utilization of CO2.

    Science.gov (United States)

    Ma, Wenqing; Liu, Xizheng; Li, Chao; Yin, Huiming; Xi, Wei; Liu, Ruirui; He, Guang; Zhao, Xian; Luo, Jun; Ding, Yi

    2018-05-21

    The excessive emission of CO 2 and the energy crisis are two major issues facing humanity. Thus, the electrochemical reduction of CO 2 and its utilization in metal-CO 2 batteries have attracted wide attention because the batteries can simultaneously accelerate CO 2 fixation/utilization and energy storage/release. Here, rechargeable Al-CO 2 batteries are proposed and realized, which use chemically stable Al as the anode. The batteries display small discharge/charge voltage gaps down to 0.091 V and high energy efficiencies up to 87.7%, indicating an efficient battery performance. Their chemical reaction mechanism to produce the performance is revealed to be 4Al + 9CO 2 ↔ 2Al 2 (CO 3 ) 3 + 3C, by which CO 2 is reversibly utilized. These batteries are envisaged to effectively and safely serve as a potential CO 2 fixation/utilization strategy with stable Al. © 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Sustained effects of atmospheric [CO2] and nitrogen availability on forest soil CO2 efflux

    Science.gov (United States)

    A. Christopher Oishi; Sari Palmroth; Kurt H. Johnsen; Heather R. McCarthy; Ram. Oren

    2014-01-01

    Soil CO2 efflux (Fsoil) is the largest source of carbon from forests and reflects primary productivity as well as how carbon is allocated within forest ecosystems. Through early stages of stand development, both elevated [CO2] and availability of soil nitrogen (N; sum of mineralization, deposition, and fixation) have been shown to increase gross primary productivity,...

  16. Well technologies for CO2 geological storage: CO2-resistant cement

    International Nuclear Information System (INIS)

    Barlet-Gouedard, V.; Rimmele, G.; Porcherie, O.; Goffe, B.

    2007-01-01

    Storing carbon dioxide (CO 2 ) underground is considered the most effective way for long-term safe and low-cost CO 2 sequestration. This recent application requires long-term well-bore integrity. A CO 2 leakage through the annulus may occur much more rapidly than geologic leakage through the formation rock, leading to economic loss, reduction of CO 2 storage efficiency, and potential compromise of the field for storage. The possibility of such leaks raises considerable concern about the long-term well-bore isolation and the durability of hydrated cement that is used to isolate the annulus across the producing/injection intervals in CO 2 -storage wells. We propose a new experimental procedure and methodology to study reactivity of CO 2 -Water-Cement systems in simulating the interaction of the set cement with injected supercritical CO 2 under downhole conditions. The conditions of experiments are 90 deg. C under 280 bars. The evolution of mechanical, physical and chemical properties of Portland cement with time is studied up to 6 months. The results are compared to equivalent studies on a new CO 2 -resistant material; the comparison shows significant promise for this new material. (authors)

  17. Uncertainties in the CO2 buget associated to boundary layer dynamics and CO2-advection

    NARCIS (Netherlands)

    Kaikkonen, J.P.; Pino, D.; Vilà-Guerau de Arellano, J.

    2012-01-01

    The relationship between boundary layer dynamics and carbon dioxide (CO2) budget in the convective boundary layer (CBL) is investigated by using mixed-layer theory. We derive a new set of analytical relations to quantify the uncertainties on the estimation of the bulk CO2 mixing ratio and the

  18. Sulfur geochemistry of hydrothermal waters in Yellowstone National Park: IV Acid-sulfate waters

    Science.gov (United States)

    Nordstrom, D. Kirk; McCleskey, R. Blaine; Ball, J.W.

    2009-01-01

    Many waters sampled in Yellowstone National Park, both high-temperature (30-94 ??C) and low-temperature (0-30 ??C), are acid-sulfate type with pH values of 1-5. Sulfuric acid is the dominant component, especially as pH values decrease below 3, and it forms from the oxidation of elemental S whose origin is H2S in hot gases derived from boiling of hydrothermal waters at depth. Four determinations of pH were obtained: (1) field pH at field temperature, (2) laboratory pH at laboratory temperature, (3) pH based on acidity titration, and (4) pH based on charge imbalance (at both laboratory and field temperatures). Laboratory pH, charge imbalance pH (at laboratory temperature), and acidity pH were in close agreement for pH ??10%, a selection process was used to compare acidity, laboratory, and charge balance pH to arrive at the best estimate. Differences between laboratory and field pH can be explained based on Fe oxidation, H2S or S2O3 oxidation, CO2 degassing, and the temperature-dependence of pK2 for H2SO4. Charge imbalances are shown to be dependent on a speciation model for pH values 350 mg/L Cl) decrease as the Cl- concentration increases from boiling which appears inconsistent with the hypothesis of H2S oxidation as a source of hydrothermal SO4. This trend is consistent with the alternate hypothesis of anhydrite solubility equilibrium. Acid-sulfate water analyses are occasionally high in As, Hg, and NH3 concentrations but in contrast to acid mine waters they are low to below detection in Cu, Zn, Cd, and Pb concentrations. Even concentrations of SO4, Fe, and Al are much lower in thermal waters than acid mine waters of the same pH. This difference in water chemistry may explain why certain species of fly larvae live comfortably in Yellowstone's acid waters but have not been observed in acid rock drainage of the same pH.

  19. Development of Novel CO2 Adsorbents for Capture of CO2 from Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Fauth, D.J.; Filburn, T.P. (University of Hartford, West Hartford, CT); Gray, M.L.; Hedges, S.W.; Hoffman, J.; Pennline, H.W.; Filburn, T.

    2007-06-01

    Capturing CO2 emissions generated from fossil fuel-based power plants has received widespread attention and is considered a vital course of action for CO2 emission abatement. Efforts are underway at the Department of Energy’s National Energy Technology Laboratory to develop viable energy technologies enabling the CO2 capture from large stationary point sources. Solid, immobilized amine sorbents (IAS) formulated by impregnation of liquid amines within porous substrates are reactive towards CO2 and offer an alternative means for cyclic capture of CO2 eliminating, to some degree, inadequacies related to chemical absorption by aqueous alkanolamine solutions. This paper describes synthesis, characterization, and CO2 adsorption properties for IAS materials previously tested to bind and release CO2 and water vapor in a closed loop life support system. Tetraethylenepentamine (TEPA), acrylonitrile-modified tetraethylenepentamine (TEPAN), and a single formulation consisting of TEPAN and N, N’-bis(2-hydroxyethyl)ethylenediamine (BED) were individually supported on a poly (methyl methacrylate) (PMMA) substrate and examined. CO2 adsorption profiles leading to reversible CO2 adsorption capacities were obtained using thermogravimetry. Under 10% CO2 in nitrogen at 25°C and 1 atm, TEPA supported on PMMA over 60 minutes adsorbed ~3.2 mmol/g{sorbent} whereas, TEPAN supported on PMMA along with TEPAN and BED supported on PMMA adsorbed ~1.7 mmol/g{sorbent} and ~2.3 mmol/g{sorbent} respectively. Cyclic experiments with a 1:1 weight ratio of TEPAN and BED supported on poly (methyl methacrylate) beads utilizing a fixed-bed flow system with 9% CO2, 3.5% O2, nitrogen balance with trace gas constituents were studied. CO2 adsorption capacity was ~ 3 mmols CO2/g{sorbent} at 40°C and 1.4 atm. No beneficial effect on IAS performance was found using a moisture-laden flue gas mixture. Tests with 750 ppmv NO in a humidified gas stream revealed negligible NO sorption onto the IAS. A high SO2

  20. CO2 capture by ionic liquids - an answer to anthropogenic CO2 emissions?

    Science.gov (United States)

    Sanglard, Pauline; Vorlet, Olivier; Marti, Roger; Naef, Olivier; Vanoli, Ennio

    2013-01-01

    Ionic liquids (ILs) are efficient solvents for the selective removal of CO2 from flue gas. Conventional, offthe-shelf ILs are limited in use to physisorption, which restricts their absorption capacity. After adding a chemical functionality like amines or alcohols, absorption of CO2 occurs mainly by chemisorption. This greatly enhances CO2 absorption and makes ILs suitable for potential industrial applications. By carefully choosing the anion and the cation of the IL, equimolar absorption of CO2 is possible. This paper reviews the current state of the art of CO2 capture by ILs and presents the current research in this field performed at the ChemTech Institute of the Ecole d'Ingénieurs et d'Architectes de Fribourg.

  1. The Li–CO2 battery: a novel method for CO2 capture and utilization

    KAUST Repository

    Xu, Shaomao

    2013-01-01

    We report a novel primary Li-CO2 battery that consumes pure CO2 gas as its cathode. The battery exhibits a high discharge capacity of around 2500 mA h g-1 at moderate temperatures. At 100 °C the discharge capacity is close to 1000% higher than that at 40 °C, and the temperature dependence is significantly weaker for higher surface area carbon cathodes. Ex-situ FTIR and XRD analyses convincingly show that lithium carbonate (Li2CO3) is the main component of the discharge product. The feasibility of similar primary metal-CO2 batteries based on earth abundant metal anodes, such as Al and Mg, is demonstrated. The metal-CO2 battery platform provides a novel approach for simultaneous capturing of CO2 emissions and producing electrical energy. © 2013 The Royal Society of Chemistry.

  2. City density and CO_2 efficiency

    International Nuclear Information System (INIS)

    Gudipudi, Ramana; Fluschnik, Till; Ros, Anselmo García Cantú; Walther, Carsten; Kropp, Jürgen P.

    2016-01-01

    Cities play a vital role in the global climate change mitigation agenda. City population density is one of the key factors that influence urban energy consumption and the subsequent GHG emissions. However, previous research on the relationship between population density and GHG emissions led to contradictory results due to urban/rural definition conundrum and the varying methodologies for estimating GHG emissions. This work addresses these ambiguities by employing the City Clustering Algorithm (CCA) and utilizing the gridded CO_2 emissions data. Our results, derived from the analysis of all inhabited areas in the US, show a sub-linear relationship between population density and the total emissions (i.e. the sum of on-road and building emissions) on a per capita basis. Accordingly, we find that doubling the population density would entail a reduction in the total CO_2 emissions in buildings and on-road sectors typically by at least 42%. Moreover, we find that population density exerts a higher influence on on-road emissions than buildings emissions. From an energy consumption point of view, our results suggest that on-going urban sprawl will lead to an increase in on-road energy consumption in cities and therefore stresses the importance of developing adequate local policy measures to limit urban sprawl. - Highlights: •We use gridded population, land use and CO_2 emissions data. •We attribute building and on-road sectoral emissions to populated settlements. •We apply CCA to identify unique city extents and population densities. •Doubling the population density increases CO_2 efficiency typically by 42%. •Population density has more influence on-road CO_2 efficiency than buildings sector.

  3. Imaging volcanic CO2 and SO2

    Science.gov (United States)

    Gabrieli, A.; Wright, R.; Lucey, P. G.; Porter, J. N.

    2017-12-01

    Detecting and quantifying volcanic carbon dioxide (CO2) and sulfur dioxide (SO2) emissions is of relevance to volcanologists. Changes in the amount and composition of gases that volcanoes emit are related to subsurface magma movements and the probability of eruptions. Volcanic gases and related acidic aerosols are also an important atmospheric pollution source that create environmental health hazards for people, animals, plants, and infrastructures. For these reasons, it is important to measure emissions from volcanic plumes during both day and night. We present image measurements of the volcanic plume at Kīlauea volcano, HI, and flux derivation, using a newly developed 8-14 um hyperspectral imaging spectrometer, the Thermal Hyperspectral Imager (THI). THI is capable of acquiring images of the scene it views from which spectra can be derived from each pixel. Each spectrum contains 50 wavelength samples between 8 and 14 um where CO2 and SO2 volcanic gases have diagnostic absorption/emission features respectively at 8.6 and 14 um. Plume radiance measurements were carried out both during the day and the night by using both the lava lake in the Halema'uma'u crater as a hot source and the sky as a cold background to detect respectively the spectral signatures of volcanic CO2 and SO2 gases. CO2 and SO2 path-concentrations were then obtained from the spectral radiance measurements using a new Partial Least Squares Regression (PLSR)-based inversion algorithm, which was developed as part of this project. Volcanic emission fluxes were determined by combining the path measurements with wind observations, derived directly from the images. Several hours long time-series of volcanic emission fluxes will be presented and the SO2 conversion rates into aerosols will be discussed. The new imaging and inversion technique, discussed here, are novel allowing for continuous CO2 and SO2 plume mapping during both day and night.

  4. CO2 Orbital Trends in Comets

    Science.gov (United States)

    Kelley, Michael; Feaga, Lori; Bodewits, Dennis; McKay, Adam; Snodgrass, Colin; Wooden, Diane

    2014-12-01

    Spacecraft missions to comets return a treasure trove of details of their targets, e.g., the Rosetta mission to comet 67P/Churyumov-Gerasimenko, the Deep Impact experiment at comet 9P/Tempel 1, or even the flyby of C/2013 A1 (Siding Spring) at Mars. Yet, missions are rare, the diversity of comets is large, few comets are easily accessible, and comet flybys essentially return snapshots of their target nuclei. Thus, telescopic observations are necessary to place the mission data within the context of each comet's long-term behavior, and to further connect mission results to the comet population as a whole. We propose a large Cycle 11 project to study the long-term activity of past and potential future mission targets, and select bright Oort cloud comets to infer comet nucleus properties, which would otherwise require flyby missions. In the classical comet model, cometary mass loss is driven by the sublimation of water ice. However, recent discoveries suggest that the more volatile CO and CO2 ices are the likely drivers of some comet active regions. Surprisingly, CO2 drove most of the activity of comet Hartley 2 at only 1 AU from the Sun where vigorous water ice sublimation would be expected to dominate. Currently, little is known about the role of CO2 in comet activity because telluric absorptions prohibit monitoring from the ground. In our Cycle 11 project, we will study the CO2 activity of our targets through IRAC photometry. In conjunction with prior observations of CO2 and CO, as well as future data sets (JWST) and ongoing Earth-based projects led by members of our team, we will investigate both long-term activity trends in our target comets, with a particular goal to ascertain the connections between each comet's coma and nucleus.

  5. Sustained effects of atmospheric [CO2] and nitrogen availability on forest soil CO2 efflux.

    Science.gov (United States)

    Oishi, A Christopher; Palmroth, Sari; Johnsen, Kurt H; McCarthy, Heather R; Oren, Ram

    2014-04-01

    Soil CO2 efflux (Fsoil ) is the largest source of carbon from forests and reflects primary productivity as well as how carbon is allocated within forest ecosystems. Through early stages of stand development, both elevated [CO2] and availability of soil nitrogen (N; sum of mineralization, deposition, and fixation) have been shown to increase gross primary productivity, but the long-term effects of these factors on Fsoil are less clear. Expanding on previous studies at the Duke Free-Air CO2 Enrichment (FACE) site, we quantified the effects of elevated [CO2] and N fertilization on Fsoil using daily measurements from automated chambers over 10 years. Consistent with previous results, compared to ambient unfertilized plots, annual Fsoil increased under elevated [CO2] (ca. 17%) and decreased with N (ca. 21%). N fertilization under elevated [CO2] reduced Fsoil to values similar to untreated plots. Over the study period, base respiration rates increased with leaf productivity, but declined after productivity saturated. Despite treatment-induced differences in aboveground biomass, soil temperature and water content were similar among treatments. Interannually, low soil water content decreased annual Fsoil from potential values - estimated based on temperature alone assuming nonlimiting soil water content - by ca. 0.7% per 1.0% reduction in relative extractable water. This effect was only slightly ameliorated by elevated [CO2]. Variability in soil N availability among plots accounted for the spatial variability in Fsoil , showing a decrease of ca. 114 g C m(-2) yr(-1) per 1 g m(-2) increase in soil N availability, with consistently higher Fsoil in elevated [CO2] plots ca. 127 g C per 100 ppm [CO2] over the +200 ppm enrichment. Altogether, reflecting increased belowground carbon partitioning in response to greater plant nutritional needs, the effects of elevated [CO2] and N fertilization on Fsoil in this stand are sustained beyond the early stages of stand development and

  6. Monitoring diffuse degassing in monogenetic volcanic field during seismic-volcanic unrest: the case of Tenerife North-West Rift Zone (NWRZ), Canary Islands, Spain

    Science.gov (United States)

    García, E.; Botelho, A. H.; Regnier, G. S. G.; Rodríguez, F.; Alonso Cótchico, M.; Melián, G.; Asensio-Ramos, M.; Padrón, E.; Hernández, P. A.; Pérez, N. M.

    2017-12-01

    Tenerife North-West Rift-Zone (NWRZ) is the most active volcano of the oceanic active volcanic island of Tenerife and the scenario of three historical eruptions (Boca Cangrejo S. XVI, Arenas Negras 1706 and Chinyero 1909). Since no visible degassing (fumaroles, etc.) at Tenerife NWRZ occurs, a geochemical monitoring program at Tenerife NWRZ was established mainly consisting on performing soil CO2 efflux surveys (50 surveys since 2000) to evaluate the temporal and spatial variations of soil CO2 efflux measurements and the diffuse CO2 emission rate. To do so, about 340 sampling sites were selected for each survey to obtain a homogeneous distribution after taking into consideration the local geology, structure, and accessibility. Measurements of soil CO2 efflux were performed in situ by means of a portable non-dispersive infrared sensor following the accumulation chamber method. The soil CO2 efflux values of the 2017 survey ranged from non-detectable to 46.6 g m-2 d-1. Statistical-graphical analysis of the 2017 data show two different geochemical populations; background (B) and peak (P) represented by 93.3% and 1.9% of the total data, respectively. The geometric means of the B and P populations are 2.4 and 19.1 g m-2 d-1, respectively. Most of the area showed B values while the P values were mainly observed at the N-W side of the volcanic rift. To estimate the diffuse CO2 emission in metric tons per day released from Tenerife NWRZ (75 km2) for the 2017 survey, we ran about 100 sGs simulations. The estimated 2017 diffuse CO2 output released to atmosphere by the Tenerife NWRZ volcano was 297 ± 13 t d-1. This 2017 diffuse CO2 emission rate value is relatively higher than the estimated background value (144 t d-1) and falls within the estimated background range (72 - 321 t d-1) observed for Tenerife NWRZ volcano during the 2000-2017 period. The observed temporal variation in the diffuse CO2 degassing output during this period does not seem to be driven by external

  7. Noble gases preserve history of retentive continental crust in the Bravo Dome natural CO2 field, New Mexico

    Science.gov (United States)

    Sathaye, Kiran J.; Smye, Andrew J.; Jordan, Jacob S.; Hesse, Marc A.

    2016-06-01

    Budgets of 4He and 40Ar provide constraints on the chemical evolution of the solid Earth and atmosphere. Although continental crust accounts for the majority of 4He and 40Ar degassed from the Earth, degassing mechanisms are subject to scholarly debate. Here we provide a constraint on crustal degassing by comparing the noble gases accumulated in the Bravo Dome natural CO2 reservoir, New Mexico USA, with the radiogenic production in the underlying crust. A detailed geological model of the reservoir is used to provide absolute abundances and geostatistical uncertainty of 4He, 40Ar, 21Ne, 20Ne, 36Ar, and 84Kr. The present-day production rate of crustal radiogenic 4He and 40Ar, henceforth referred to as 4He* and 40Ar*, is estimated using the basement composition, surface and mantle heat flow, and seismic estimates of crustal density. After subtracting mantle and atmospheric contributions, the reservoir contains less than 0.02% of the radiogenic production in the underlying crust. This shows unequivocally that radiogenic noble gases are effectively retained in cratonic continental crust over millennial timescales. This also requires that approximately 1.5 Gt of mantle derived CO2 migrated through the crust without mobilizing the crustally accumulated gases. This observation suggests transport along a localized fracture network. Therefore, the retention of noble gases in stable crystalline continental crust allows shallow accumulations of radiogenic gases to record tectonic history. At Bravo Dome, the crustal 4He*/40Ar* ratio is one fifth of the expected crustal production ratio, recording the preferential release of 4He during the Ancestral Rocky Mountain orogeny, 300 Ma.

  8. Quantification of the CO2 emitted from volcanic lakes in Pico Island (Azores)

    Science.gov (United States)

    Andrade, César; Cruz, José; Viveiros, Fátima; Branco, Rafael

    2017-04-01

    This study shows the results of the diffuse CO2 degassing surveys performed in lakes from Pico volcanic Island (Azores archipelago, Portugal). Detailed flux measurements using the accumulation chamber method were made at six lakes (Capitão, Caiado, Paul, Rosada, Peixinho and Negra) during two field campaigns, respectively, in winter (February 2016) and late summer (September 2016). Pico is the second largest island of the Azores archipelago with an area of 444.8 km2; the oldest volcanic unit is dated from about 300,000 years ago. The edification of Pico was mainly due to Hawaiian and Strombolian type volcanic activity, resulting in pahoehoe and aa lava flows of basaltic nature, as well as scoria and spatter cones. Three main volcanic complexes are identified in the island, namely (1) the so-called Montanha Volcanic Complex, corresponding to a central volcano located in the western side of the island that reaches a maximum altitude of 2351 m, (2) the São Roque-Piedade Volcanic Complex, and (3) the Topo-Lajes Volcanic Complex, this last one corresponding to the remnants of a shield volcano located in the south coast. The studied lakes are spread along the São Roque-Piedade Volcanic Complex at altitudes between 785 m and 898 m. Three are associated with depressions of undifferentiated origin (Caiado, Peixinho, Negra), two with depressions of tectonic origin (Capitão, Paul), while Rosada lake is located inside a scoria cone crater. The lakes surface areas vary between 1.25x10-2 and 5.38x10-2 km2, and the water column maximum depth is 7.9 m (3.5-7.9 m). The water storage ranges between 3.6x104 to 9.1x104 m3, and the estimated residence time does not exceed 1.8x10-1 years. A total of 1579 CO2 flux measurements were made during both surveys (868 in summer and 711 in the winter campaign), namely 518 in Caiado lake (293; 225), 358 in Paul (195; 163), 279 in Capitão (150, 129), 200 in Rosada (106, 94), 171 in Peixinho (71, 100) and 53 measurements in Negra lake. Negra

  9. Prodigious degassing of a billion years of accumulated radiogenic helium at Yellowstone

    Science.gov (United States)

    Lowenstern, Jacob B.; Evans, William C.; Bergfeld, D.; Hunt, Andrew G.

    2014-01-01

    Helium is used as a critical tracer throughout the Earth sciences, where its relatively simple isotopic systematics is used to trace degassing from the mantle, to date groundwater and to time the rise of continents1. The hydrothermal system at Yellowstone National Park is famous for its high helium-3/helium-4 isotope ratio, commonly cited as evidence for a deep mantle source for the Yellowstone hotspot2. However, much of the helium emitted from this region is actually radiogenic helium-4 produced within the crust by α-decay of uranium and thorium. Here we show, by combining gas emission rates with chemistry and isotopic analyses, that crustal helium-4 emission rates from Yellowstone exceed (by orders of magnitude) any conceivable rate of generation within the crust. It seems that helium has accumulated for (at least) many hundreds of millions of years in Archaean (more than 2.5 billion years old) cratonic rocks beneath Yellowstone, only to be liberated over the past two million years by intense crustal metamorphism induced by the Yellowstone hotspot. Our results demonstrate the extremes in variability of crustal helium efflux on geologic timescales and imply crustal-scale open-system behaviour of helium in tectonically and magmatically active regions.

  10. CO2 dispersion modelling over Paris region within the CO2-MEGAPARIS project

    Directory of Open Access Journals (Sweden)

    C. Lac

    2013-05-01

    Full Text Available Accurate simulation of the spatial and temporal variability of tracer mixing ratios over urban areas is a challenging and interesting task needed to be performed in order to utilise CO2 measurements in an atmospheric inverse framework and to better estimate regional CO2 fluxes. This study investigates the ability of a high-resolution model to simulate meteorological and CO2 fields around Paris agglomeration during the March field campaign of the CO2-MEGAPARIS project. The mesoscale atmospheric model Meso-NH, running at 2 km horizontal resolution, is coupled with the Town Energy Balance (TEB urban canopy scheme and with the Interactions between Soil, Biosphere and Atmosphere CO2-reactive (ISBA-A-gs surface scheme, allowing a full interaction of CO2 modelling between the surface and the atmosphere. Statistical scores show a good representation of the urban heat island (UHI with stronger urban–rural contrasts on temperature at night than during the day by up to 7 °C. Boundary layer heights (BLH have been evaluated on urban, suburban and rural sites during the campaign, and also on a suburban site over 1 yr. The diurnal cycles of the BLH are well captured, especially the onset time of the BLH increase and its growth rate in the morning, which are essential for tall tower CO2 observatories. The main discrepancy is a small negative bias over urban and suburban sites during nighttime (respectively 45 m and 5 m, leading to a few overestimations of nocturnal CO2 mixing ratios at suburban sites and a bias of +5 ppm. The diurnal CO2 cycle is generally well captured for all the sites. At the Eiffel tower, the observed spikes of CO2 maxima occur every morning exactly at the time at which the atmospheric boundary layer (ABL growth reaches the measurement height. At suburban ground stations, CO2 measurements exhibit maxima at the beginning and at the end of each night, when the ABL is fully contracted, with a strong spatio-temporal variability. A

  11. Global CO2 fluxes estimated from GOSAT retrievals of total column CO2

    Directory of Open Access Journals (Sweden)

    S. Basu

    2013-09-01

    Full Text Available We present one of the first estimates of the global distribution of CO2 surface fluxes using total column CO2 measurements retrieved by the SRON-KIT RemoTeC algorithm from the Greenhouse gases Observing SATellite (GOSAT. We derive optimized fluxes from June 2009 to December 2010. We estimate fluxes from surface CO2 measurements to use as baselines for comparing GOSAT data-derived fluxes. Assimilating only GOSAT data, we can reproduce the observed CO2 time series at surface and TCCON sites in the tropics and the northern extra-tropics. In contrast, in the southern extra-tropics GOSAT XCO2 leads to enhanced seasonal cycle amplitudes compared to independent measurements, and we identify it as the result of a land–sea bias in our GOSAT XCO2 retrievals. A bias correction in the form of a global offset between GOSAT land and sea pixels in a joint inversion of satellite and surface measurements of CO2 yields plausible global flux estimates which are more tightly constrained than in an inversion using surface CO2 data alone. We show that assimilating the bias-corrected GOSAT data on top of surface CO2 data (a reduces the estimated global land sink of CO2, and (b shifts the terrestrial net uptake of carbon from the tropics to the extra-tropics. It is concluded that while GOSAT total column CO2 provide useful constraints for source–sink inversions, small spatiotemporal biases – beyond what can be detected using current validation techniques – have serious consequences for optimized fluxes, even aggregated over continental scales.

  12. Geochemical Interaction of Middle Bakken Reservoir Rock and CO2 during CO2-Based Fracturing

    Science.gov (United States)

    Nicot, J. P.; Lu, J.; Mickler, P. J.; Ribeiro, L. H.; Darvari, R.

    2015-12-01

    This study was conducted to investigate the effects of geochemical interactions when CO2 is used to create the fractures necessary to produce hydrocarbons from low-permeability Middle Bakken sandstone. The primary objectives are to: (1) identify and understand the geochemical reactions related to CO2-based fracturing, and (2) assess potential changes of reservoir property. Three autoclave experiments were conducted at reservoir conditions exposing middle Bakken core fragments to supercritical CO2 (sc-CO2) only and to CO2-saturated synthetic brine. Ion-milled core samples were examined before and after the reaction experiments using scanning electron microscope, which enabled us to image the reaction surface in extreme details and unambiguously identify mineral dissolution and precipitation. The most significant changes in the reacted rock samples exposed to the CO2-saturated brine is dissolution of the carbonate minerals, particularly calcite which displays severely corrosion. Dolomite grains were corroded to a lesser degree. Quartz and feldspars remained intact and some pyrite framboids underwent slight dissolution. Additionally, small amount of calcite precipitation took place as indicated by numerous small calcite crystals formed at the reaction surface and in the pores. The aqueous solution composition changes confirm these petrographic observations with increase in Ca and Mg and associated minor elements and very slight increase in Fe and sulfate. When exposed to sc-CO2 only, changes observed include etching of calcite grain surface and precipitation of salt crystals (halite and anhydrite) due to evaporation of residual pore water into the sc-CO2 phase. Dolomite and feldspars remained intact and pyrite grains were slightly altered. Mercury intrusion capillary pressure tests on reacted and unreacted samples shows an increase in porosity when an aqueous phase is present but no overall porosity change caused by sc-CO2. It also suggests an increase in permeability

  13. National CO2 emissions trading in European perspective; Nationale CO2-emissiehandel in Europees perspectief

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-06-01

    This report is the reaction of the Social and economic council (SER) in the Netherlands to the request of the Dutch Ministry of Housing, Spatial Planning en Environment (VROM) to formulate an advice on the final report of the Committee CO2 Trade (a.k.a the Vogtlander Committee). This Committee has drafted a proposal for a CO2 emission trade system in the Netherlands. The SER has also taken into account the proposal of the European Committee on a guideline for CO2 emission trade in the European Union (EU)

  14. Solubility of krypton in liquid CO2

    International Nuclear Information System (INIS)

    Notz, K.J.; Meservey, A.B.

    1976-06-01

    The solubility of krypton in liquid CO 2 was measured experimentally over essentially the entire liquid range of CO 2 , from -53 to 29 0 C. A tracer technique using 85 Kr was employed, and equilibrated gas-liquid samples were analyzed in situ with a collimated counter. Dilute concentrations of krypton were used, and the data are expressed as a distribution ratio, Y/sub Kr//X/sub Kr/, the log of which is nearly linear with respect to temperature from the lowest temperature to about 20 0 C, above which the values fall off rapidly toward a value of unity at the critical temperature. The numerical values obtained for the distribution ratio increase from 1.44 at 29 0 C to 29.4 at -53 0 C

  15. Toxic emissions and devalued CO2-neutrality

    DEFF Research Database (Denmark)

    Czeskleba-Dupont, Rolf

    With reference to the paradigme shift regarding the formation of dioxins in municiplan solid waste incinerators experimental results are taken into account which lead to the suspicion that the same mechanism of de-novo-synthesis also applies to fireplace chimneys. This can explain the dioxin...... friendly effects of substituting wood burning for fossil fuels. With reference to Bent Sørensen's classical work on 'Renewable Energy' the assumption of CO2-neutrality regarding incineration is problematised when applied to plants with long rotation periods as trees. Registered CO2-emissions from wood...... burning are characterised together with particle and PAH emissions. The positive treatment of wood stove-technology in the Danish strategy for sustainable development (draft 2007) is critically evaluated and approaches to better regulation are identified....

  16. A centrifuge CO2 pellet cleaning system

    International Nuclear Information System (INIS)

    Foster, C.A.; Fisher, P.W.; Nelson, W.D.; Schechter, D.E.

    1993-01-01

    Centrifuge-based cryogenic pellet accelerator technology, originally developed at Oak Ridge National Laboratory (ORNL) for the purpose of refueling fusion reactors with high-speed pellets of frozen deuterium/tritium,is now being developed as a method of cleaning without the use of conventional solvents. In these applications large quantities of pellets made of frozen CO 2 or argon are accelerated in a high-speed rotor. The accelerated pellet stream is used to clean or etch surfaces. The advantage of this system is that the spent pellets and debris resulting from the cleaning process can be filtered leaving only the debris for disposal. This paper discusses the centrifuge CO 2 pellet cleaning system, the physics model of the pellet impacting the surface, the centrifuge apparatus, and some initial cleaning and etching tests

  17. Molecular simulations of CO2 at interfaces

    DEFF Research Database (Denmark)

    Silvestri, Alessandro

    trapping mechanisms that act over dierent time scales, where eectiveness is determined by phenomena that occur at the interfaces between CO2, pore uids and the pore surfaces. Solid theoretical understanding of the nanoscale interactions that result from the interplay of intermolecular and surface forces...... variety of conditions: pressure, temperature, pore solution salinity and various mineral surfaces. However, achieving representative subsurface conditions in experiments is challenging and reported data are aected by experimental uncertainties and sometimes are contradictory. Molecular modelling...... rock record and the formations are generally porous so their probable response to CO2 sequestration needs to be investigated. However, despite the large number of geologic sequestration publications on water{rock interactions over the last decade, studies on carbonate reservoirs remain scarce...

  18. Toxic emissions and devaluated CO2-neutrality

    DEFF Research Database (Denmark)

    Czeskleba-Dupont, Rolf

    Environmental, energy and climate policies need fresh reflections. In order to evaluate toxics reduction policies the Stockholm Convention on Persistent Organic Pollutants is mandatory. Denmark's function as lead country for dioxin research in the context of the OSPAR Convention is contrasted...... with a climate policy whose goals of CO2-reduction were made operational by green-wash. Arguments are given for the devaluation of CO2- neutrality in case of burning wood. Alternative practices as storing C in high quality wood products and/or leaving wood in the forest are recommended. A counter......-productive effect of dioxin formation in the cooling phase of wood burning appliances has been registered akin to de-novo-synthesis in municipal solid waste incinerators. Researchers, regulators and the public are, however, still preoccupied by notions of oven design and operation parameters, assuming that dioxin...

  19. Sustainable Process Networks for CO2 Conversion

    DEFF Research Database (Denmark)

    Frauzem, Rebecca; Kongpanna, P.; Pavarajam, V.

    According to various organizations, especially the Intergovernmental Panel on Climate Change, global warming is an ever-increasing threat to the environment and poses a problem if not addressed. As a result, efforts are being made across academic and industrial fields to find methods of reducing...... drawbacks to this geologic storage system: the CO2 is not eliminated, the implementation is limited due to natural phenomena, and the capturing methods are often expensive. Thus, it is desirable to develop an alternative strategy for reducing the CO2 emissions [2]. An additional process that reduces...... that are thermodynamically feasible, including the co-reactants, catalysts, operating conditions and reactions. Research has revealed that there are a variety of reactions that fulfill the aforementioned criteria. The products that are formed fall into categories: fuels, bulk chemicals and specialty chemicals. While fuels...

  20. Relationships between CO2, thermodynamic limits on silicate weathering, and the strength of the silicate weathering feedback

    Science.gov (United States)

    Winnick, Matthew J.; Maher, Kate

    2018-03-01

    Recent studies have suggested that thermodynamic limitations on chemical weathering rates exert a first-order control on riverine solute fluxes and by extension, global chemical weathering rates. As such, these limitations may play a prominent role in the regulation of carbon dioxide levels (pCO2) over geologic timescales by constraining the maximum global weathering flux. In this study, we develop a theoretical scaling relationship between equilibrium solute concentrations and pCO2 based on equilibrium constants and reaction stoichiometry relating primary mineral dissolution and secondary mineral precipitation. We test this theoretical scaling relationship against reactive transport simulations of chemical weathering profiles under open- and closed-system conditions, representing partially and fully water-saturated regolith, respectively. Under open-system conditions, equilibrium bicarbonate concentrations vary as a power-law function of pCO2 (y = kxn) where n is dependent on reaction stoichiometry and k is dependent on both reaction stoichiometry and the equilibrium constant. Under closed-system conditions, bicarbonate concentrations vary linearly with pCO2 at low values and approach open-system scaling at high pCO2. To describe the potential role of thermodynamic limitations in the global silicate weathering feedback, we develop a new mathematical framework to assess weathering feedback strength in terms of both (1) steady-state atmospheric pCO2 concentrations, and (2) susceptibility to secular changes in degassing rates and transient carbon cycle perturbations, which we term 1st and 2nd order feedback strength, respectively. Finally, we discuss the implications of these results for the effects of vascular land plant evolution on feedback strength, the potential role of vegetation in controlling modern solute fluxes, and the application of these frameworks to a more complete functional description of the silicate weathering feedback. Most notably, the dependence

  1. Continuous CO2 extractor and methods

    Energy Technology Data Exchange (ETDEWEB)

    None listed

    2010-06-15

    The purpose of this CRADA was to assist in technology transfer from Russia to the US and assist in development of the technology improvements and applications for use in the U.S. and worldwide. Over the period of this work, ORNL has facilitated design, development and demonstration of a low-pressure liquid extractor and development of initial design for high-pressure supercritical CO2 fluid extractor.

  2. Continuous CO2 extractor and methods

    International Nuclear Information System (INIS)

    2010-01-01

    The purpose of this CRADA was to assist in technology transfer from Russia to the US and assist in development of the technology improvements and applications for use in the U.S. and worldwide. Over the period of this work, ORNL has facilitated design, development and demonstration of a low-pressure liquid extractor and development of initial design for high-pressure supercritical CO2 fluid extractor.

  3. Throat gases against the CO2

    International Nuclear Information System (INIS)

    Michaut, C.

    2006-01-01

    The steel production needs carbon consumption and generates carbon dioxide, the main greenhouse gases. It represents about 6 % of the greenhouse gases emissions in the world. That is why the steel industry began last year a research program, Ideogaz, to reduce its CO 2 releases. The first results on the throat gases recovery seems very promising: it uses 25 % less of carbon. The author presents the program and the main technical aspects of the method. (A.L.B.)

  4. Panorama 2016 - Chemical recycling of CO2

    International Nuclear Information System (INIS)

    Forti, Laurent; Fosse, Florian

    2015-12-01

    The ongoing rise of atmospheric carbon dioxide concentration is a major environmental and societal concern. Among the potential solutions for reducing carbon emissions in the energy sector, the chemical recycling of CO 2 has received considerable attention. Conversion of carbon dioxide into other recoverable substances offers the benefit of reducing the carbon footprint of newly developed products and of shifting away from the use of fossil resources. Various methods to create a wide range of products are currently being studied. (authors)

  5. Influence of CO2 on the climate

    International Nuclear Information System (INIS)

    Junod, A.

    1989-01-01

    The earth's climate is subject to long and short term fluctuations. The recent ones are being caused by mankind. The most important result is the increase in the CO 2 -content of the atmosphere, caused by burning of fossil fuels. This leads to the so-called greenhouse effect. It is judged that the average temperature of the earth's surface will rise by 2 o C between the years 2030 and 2050

  6. CO2 capture takes its industrial turn

    International Nuclear Information System (INIS)

    Remoue, A.; Lutzky, A.

    2009-01-01

    The CO 2 capture and sequestration is entering the industrial era. The technologies are ready, the regulation is progressively put into action, the financing of demonstration facilities is unfreezing and companies are on the starting line from Canada to China, including the USA and Europe. The market takeoff is expected for 2015 but the competition is already hard between equipment manufacturers who wish to develop proprietary technologies. (J.S.)

  7. Aridity under conditions of increased CO2

    Science.gov (United States)

    Greve, Peter; Roderick, Micheal L.; Seneviratne, Sonia I.

    2016-04-01

    A string of recent of studies led to the wide-held assumption that aridity will increase under conditions of increasing atmospheric CO2 concentrations and associated global warming. Such results generally build upon analyses of changes in the 'aridity index' (the ratio of potential evaporation to precipitation) and can be described as a direct thermodynamic effect on atmospheric water demand due to increasing temperatures. However, there is widespread evidence that contradicts the 'warmer is more arid' interpretation, leading to the 'global aridity paradox' (Roderick et al. 2015, WRR). Here we provide a comprehensive assessment of modeled changes in a broad set of dryness metrics (primarily based on a range of measures of water availability) over a large range of realistic atmospheric CO2 concentrations. We use an ensemble of simulations from of state-of-the-art climate models to analyse both equilibrium climate experiments and transient historical simulations and future projections. Our results show that dryness is, under conditions of increasing atmospheric CO2 concentrations and related global warming, generally decreasing at global scales. At regional scales we do, however, identify areas that undergo changes towards drier conditions, located primarily in subtropical climate regions and the Amazon Basin. Nonetheless, the majority of regions, especially in tropical and mid- to northern high latitudes areas, display wetting conditions in a warming world. Our results contradict previous findings and highlight the need to comprehensively assess all aspects of changes in hydroclimatological conditions at the land surface. Roderick, M. L., P. Greve, and G. D. Farquhar (2015), On the assessment of aridity with changes in atmospheric CO2, Water Resour. Res., 51, 5450-5463

  8. Water column imaging on hydrothermal vent in Central Indian Ridge

    Science.gov (United States)

    Koh, J.; Park, Y.

    2017-12-01

    Water column imaging with Multibeam echosounder systems (MBES) is recently becoming of increasing interest for oceanographic studies. Especially gas bubbles and hot water exposed from hydrothermal vents make acoustic impedance anomalies in cold seawater, water column imaging is very useful for the researchers who want to detect some kinds of hydrothermal activity. We conducted a hydrothermal exploration program, called "INVENT17", using the MBES system, KONGBERG EM122 (12kHz, 1°×1°), mounted on R/V ISABU and we deployed other equipments including video guided hydraulic grab, tow-yo CTD and general CTD with MAPR (Miniature Autonomous Plume Recorder) in 2017. First, to evaluate its capabilities of detection of hydrothermal vent, the surveys using the MBES were conducted at the Solitaire Field, previously identified hydrothermal area of the Central Indian Ridge. The bathymetric data obtained from MBES provided information about detailed morphology of seafloor, but we were not able to achieve the information from the water column imaging data. But the clue of existence of active hydrothermal vent was detected through the values of ΔNTU, dEh/dt, and OPR gained from MAPR, the data means that the hydrothermal activity affects 100m from the seafloor. It could be the reason that we can't find the hydrothermal activity because the range resolution of water column imaging is pretty rough so that the size of 100m-scaled activity has low possibility to distinguish from seafloor. The other reason is there are no sufficient objects to cause strong scattering like as CO2 bubbles or droplets unlike in the mid-Okinawa Trough. And this suggests that can be a important standard to identify properties of hydrothermal vent sites depending on the presence of scattering objects in water mass. To justify this, we should perform more chemical analysis of hot water emanating from hydrothermal vent and collected several bottles of water sample to do that.

  9. Towards Overhauser DNP in supercritical CO(2).

    Science.gov (United States)

    van Meerten, S G J; Tayler, M C D; Kentgens, A P M; van Bentum, P J M

    2016-06-01

    Overhauser Dynamic Nuclear Polarization (ODNP) is a well known technique to improve NMR sensitivity in the liquid state, where the large polarization of an electron spin is transferred to a nucleus of interest by cross-relaxation. The efficiency of the Overhauser mechanism for dipolar interactions depends critically on fast local translational dynamics at the timescale of the inverse electron Larmor frequency. The maximum polarization enhancement that can be achieved for (1)H at high magnetic fields benefits from a low viscosity solvent. In this paper we investigate the option to use supercritical CO2 as a solvent for Overhauser DNP. We have investigated the diffusion constants and longitudinal nuclear relaxation rates of toluene in high pressure CO2. The change in (1)H T1 by addition of TEMPO radical was analyzed to determine the Overhauser cross-relaxation in such a mixture, and is compared with calculations based on the Force Free Hard Sphere (FFHS) model. By analyzing the relaxation data within this model we find translational correlation times in the range of 2-4ps, depending on temperature, pressure and toluene concentration. Such short correlation times may be instrumental for future Overhauser DNP applications at high magnetic fields, as are commonly used in NMR. Preliminary DNP experiments have been performed at 3.4T on high pressure superheated water and model systems such as toluene in high pressure CO2. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Development of longitudinally excited CO2 laser

    Science.gov (United States)

    Masroon, N. S.; Tanaka, M.; Tei, M.; Uno, K.; Tsuyama, M.; Nakano, H.

    2018-05-01

    Simple, compact, and affordable discharged-pumped CO2 laser controlled by a fast high voltage solid state switch has been developed. In this study, longitudinal excitation scheme has been adapted for simple configuration. In the longitudinal excitation scheme, the discharge is produced along the direction of the laser axis, and the electrodes are well separated with a small discharge cross-section. Triggered spark gap switch is usually used to switch out the high voltage because of simple and low cost. However, the triggered spark gap operates in the arc mode and suffer from recovery problem causing a short life time and low efficiency for high repetition rate operation. As a result, there is now considerable interest in replacing triggered spark gap switch with solid state switches. Solid state switches have significant advantages compared to triggered spark gap switch which include longer service lifetime, low cost and stable high trigger pulse. We have developed simple and low cost fast high voltage solid state switch that consists of series connected-MOSFETs. It has been installed to the longitudinally excited CO2 laser to realize the gap switch less operation. Characteristics of laser oscillation by varying the discharge length, charging voltage, capacitance and gas pressure have been evaluated. Longer discharge length produce high power of laser oscillation. Optimum charging voltage and gas pressure were existed for longitudinally excited CO2 laser.

  11. Martian Gullies: Formation by CO2 Fluidification

    Science.gov (United States)

    Cedillo-Flores, Y.; Durand-Manterola, H. J.

    2006-12-01

    Some of the geomorphological features in Mars are the gullies. Some theories developed tried explain its origin, either by liquid water, liquid carbon dioxide or flows of dry granular material. We made a comparative analysis of the Martian gullies with the terrestrial ones. We propose that the mechanism of formation of the gullies is as follows: In winter CO2 snow mixed with sand falls in the terrain. In spring the CO2 snow sublimate and gaseous CO2 make fluid the sand which flows like liquid eroding the terrain and forming the gullies. By experimental work with dry granular material, we simulated the development of the Martian gullies injecting air in the granular material. We present the characteristics of some terrestrial gullies forms at cold environment, sited at Nevado de Toluca Volcano near Toluca City, México. We compare them with Martian gullies choose from four different areas, to target goal recognize or to distinguish, (to identify) possible processes evolved in its formation. Also, we measured the lengths of those Martian gullies and the range was from 24 m to 1775 meters. Finally, we present results of our experimental work at laboratory with dry granular material.

  12. Effect of Degassing Treatment on the Interfacial Reaction of Molten Aluminum and Solid Steel

    Directory of Open Access Journals (Sweden)

    Triyono T.

    2017-06-01

    Full Text Available The gas porosity is one of the most serious problems in the casting of aluminum. There are several degassing methods that have been studied. During smelting of aluminum, the intermetallic compound (IMC may be formed at the interface between molten aluminum and solid steel of crucible furnace lining. In this study, the effect of degassing treatment on the formations of IMC has been investigated. The rectangular substrate specimens were immersed in a molten aluminum bath. The holding times of the substrate immersions were in the range from 300 s to 1500 s. Two degassing treatments, argon degassing and hexachloroethane tablet degassing, were conducted to investigate their effect on the IMC formation. The IMC was examined under scanning electron microscope with EDX attachment. The thickness of the IMC layer increased with increasing immersion time for all treatments. Due to the high content of hydrogen, substrate specimens immersed in molten aluminum without degasser had IMC layer which was thicker than others. Argon degassing treatment was more effective than tablet degassing to reduce the IMC growth. Furthermore, the hard and brittle phase of IMC, FeAl3, was formed dominantly in specimens immersed for 900 s without degasser while in argon and tablet degasser specimens, it was formed partially.

  13. Hierarchically porous Ni monolith@branch-structured NiCo2O4 for high energy density supercapacitors

    Directory of Open Access Journals (Sweden)

    Mengjie Xu

    2016-06-01

    Full Text Available A variety of NiCo2O4 nanostrucutures ranging from nanowire to nanoplate and branched structures were successfully prepared via a simple hydrothermal process. The experimental results show that NiCo2O4 with branched structures possesses the best overall electrochemical performance. The improvement of energy density was explored in terms of hierarchically three-dimensional (3D metal substrates and a high specific area capacitance, and area energy density is obtained with hierarchically porous Ni monolith synthesized through a controlled combustion procedure.

  14. Helium evidences for mantle degassing in the groundwater of Madeira Island – Portugal

    International Nuclear Information System (INIS)

    Amaral, Helena I.F.; Midões, Carla; Kipfer, Rolf

    2017-01-01

    The Madeira Island is fed by an active hotspot, but there are no evidences of current volcanism and geothermal activity or, of a heat source at depth, which probably justifies why only low temperature and low TDS groundwater is found in Madeira. Nonetheless, Madeira is a relatively young island (≤7 Ma old), and a connection to the upper mantle through geological conduits, is likely to occur. To investigate whether such a connection exists, noble gases and stable isotopes were, so far as we know, for the first time measured in groundwater samples of the main (basal) aquifer of Madeira Is. Groundwater is the main supply of drinking water in Madeira Is., and the hydrogeology of the island has been well characterized in previous studies. In this study, groundwater was generically divided into ‘cold’ waters (<20 °C, near the coast) and ‘warm’ waters (20–25 °C, central part of the island). This division was based on field temperature, water chemistry and stable isotopic composition. Four ‘hot’ waters (23–25 °C) showed partly distinct characteristics. A bubbling spring was also sampled. Very low tritium values indicate groundwater recharged recently and/or mix with free-tritium waters. Groundwater is fed by rain recharged during autumn as indicated by δ"1"8O and δ"2H signatures. During infiltration, the waters dissolved soil CO_2 that according to the back-calculated δ"1"3C-CO_2 compositions corresponds mainly to CO_2 of biogenic origin. Nonetheless, a mantle CO_2 component cannot be excluded from samples from the inner part of the island. The noblegas helium was the sole tracer indicating a deep gas contribution to the groundwater. A strong mantle signal was detected in the ‘hot’ and bubbling waters, as indicated by their He-Ra values of 8 (being Ra the atmospheric "3He/"4He ratio), typical of the MORB. Thus, even if the last volcanic eruption occurred ca. 0,006 Ma, degassing of the upper-mantle was detected in the shallow cold waters of

  15. Natural Analogues of CO2 Geological Storage; Analogos Naturales del Almacenamiento Geologico de CO2

    Energy Technology Data Exchange (ETDEWEB)

    Perez del Villar, L; Pelayo, M; Recreo, F

    2007-07-20

    Geological storage of carbon dioxide is nowadays, internationally considered as the most effective method for greenhouse gas emission mitigation, in order to minimize the global climate change universally accepted. Nevertheless, the possible risks derived of this long-term storage have a direct influence on its public acceptance. Among the favourable geological formations to store CO2, depleted oil and gas fields, deep saline reservoirs, and unamiable coal seams are highlighted. One of the most important objectives of the R and D projects related to the CO2 geological storage is the evaluation of the CO2 leakage rate through the above mentioned geological formations. Therefore, it is absolutely necessary to increase our knowledge on the interaction among CO2, storage and sealing formations, as well as on the flow paths and the physical resistance of the sealing formation. The quantification of the CO2 leakage rate is essential to evaluate the effects on the human and animal health, as well as for the ecosystem and water quality. To achieve these objectives, the study of the natural analogues is very useful in order to know the natural leakage rate to the atmosphere, its flow paths, the physical, chemical and mineralogical modifications due to the long term interaction processes among the CO2 and the storage and sealing formations, as well as the effects on the groundwaters and ecosystems. In this report, we have tried to summarise the main characteristics of the natural reservoirs and surficial sources of CO2, which are both natural analogues of the geological storage and CO2 leakage, studied in EEUU, Europe and Australia. The main objective of this summary is to find the possible applications for long-term risk prediction and for the performance assessment by means of conceptual and numerical modelling, which will allow to validate the predictive models of the CO2 storage behaviour, to design and develop suitable monitoring techniques to control the CO2 behaviour

  16. Recycling CO 2 ? Computational Considerations of the Activation of CO 2 with Homogeneous Transition Metal Catalysts

    KAUST Repository

    Drees, Markus

    2012-08-10

    Faced with depleting fossil carbon sources, the search for alternative energy carriers and energy storage possibilities has become an important issue. Nature utilizes carbon dioxide as starting material for storing sun energy in plant hydrocarbons. A similar approach, storing energy from renewable sources in chemical bonds with CO 2 as starting material, may lead to partial recycling of CO 2 created by human industrial activities. Unfortunately, currently available routes for the transformation of CO 2 involve high temperatures and are often not selective. With the development of more sophisticated methods and better software, theoretical studies have become both increasingly widespread and useful. This concept article summarizes theoretical investigations of the current state of the feasibility of CO 2 activation with molecular transition metal catalysts, highlighting the most promising reactions of CO 2 with olefins to industrially relevant acrylic acid/acrylates, and the insertion of CO 2 into metal-element bonds, particularly for the synthesis of cyclic carbonates and polymers. Rapidly improving computational power and methods help to increase the importance and accuracy of calculations continuously and make computational chemistry a useful tool helping to solve some of the most important questions for the future. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. CO2 capture by gas hydrate crystallization: Application on the CO2-N2 mixture

    International Nuclear Information System (INIS)

    Bouchemoua, A.

    2012-01-01

    CO 2 capture and sequestration represent a major industrial and scientific challenge of this century. There are different methods of CO 2 separation and capture, such as solid adsorption, amines adsorption and cryogenic fractionation. Although these processes are well developed at industrial level, they are energy intensive. Hydrate formation method is a less energy intensive and has an interesting potential to separate carbon dioxide. Gas hydrates are Document crystalline compounds that consist of hydrogen bonded network of water molecules trapping a gas molecule. Gas hydrate formation is favored by high pressure and low temperature. This study was conducted as a part of the SECOHYA ANR Project. The objective is to study the thermodynamic and kinetic conditions of the process to capture CO 2 by gas hydrate crystallization. Firstly, we developed an experimental apparatus to carry out experiments to determine the thermodynamic and kinetic formation conditions of CO 2 -N 2 gas hydrate mixture in water as liquid phase. We showed that the operative pressure may be very important and the temperature very low. For the feasibility of the project, we used TBAB (Tetrabutylammonium Bromide) as thermodynamic additive in the liquid phase. The use of TBAB may reduce considerably the operative pressure. In the second part of this study, we presented a thermodynamic model, based on the van der Waals and Platteeuw model. This model allows the estimation of thermodynamic equilibrium conditions. Experimental equilibrium data of CO 2 -CH 4 and CO 2 -N 2 mixtures are presented and compared to theoretical results. (author)

  18. Monitoring diffuse degassing in monogentic volcanic field during magmatic reactivation: the case of El Hierro (Canary Islands, Spain)

    Science.gov (United States)

    Morales-Ocaña, C.; Feldman, R. C.; Pointer, Z. R.; Rodríguez, F.; Asensio-Ramos, M.; Melián, G.; Padrón, E.; Hernández, P. A.; Pérez, N. M.

    2017-12-01

    El Hierro (278 km2), the younger, smallest and westernmost island of the Canarian archipelago, is a 5-km-high edifice constructed by rapid constructive and destructive processes in 1.12 Ma, with a truncated trihedron shape and three convergent ridges of volcanic cones. It experienced a submarine eruption from 12 October, 2011 and 5 March 2012, off its southern coast that was the first one to be monitored from the beginning in the Canary Islands. As no visible emanations occur at the surface environment of El Hierro, diffuse degassing studies have become a useful geochemical tool to monitor the volcanic activity in this volcanic island. Diffuse CO2 emission has been monitored at El Hierro Island since 1998 in a yearly basis, with much higher frequency in the period 2011-2012. At each survey, about 600 sampling sites were selected to obtain a homogeneous distribution. Measurements of soil CO2 efflux were performed in situ following the accumulation chamber method. During pre-eruptive and eruptive periods, the diffuse CO2 emission released by the whole island experienced significant increases before the onset of the submarine eruption and the most energetic seismic events of the volcanic-seismic unrest (Melián et al., 2014. J. Geophys. Res. Solid Earth, 119, 6976-6991). The soil CO2 efflux values of the 2017 survey ranged from non-detectable to 53.1 g m-2 d-1. Statistical-graphical analysis of the data show two different geochemical populations; background (B) and peak (P) represented by 77.6% and 22.4% of the total data, respectively, with geometric means of 1.8 and 9.2 g m-2 d-1, respectively. Most of the area showed B values while the P values were mainly observed at the interception center of the three convergent ridges and the north of the island. To estimate the diffuse CO2 emission for the 2017 survey, we ran about 100 sGs simulations. The estimated 2017 diffuse CO2 output released to atmosphere by El Hierro was at 1,150 ± 42 t d-1, value higher than the

  19. Diffuse Carbon Dioxide Degassing Monitoring at Santa Ana-Izalco-Coatepeque Volcanic System, El Salvador, Central America

    Science.gov (United States)

    Olmos, R.; Barahona, F.; Cartagena, R.; Soriano, T.; Salazar, J.; Hernandez, P.; Perez, N.; Notsu, K.; Lopez, D.

    2001-12-01

    Santa Ana volcanic complex (0.22 Ma), located 40 Km west of San Salvador, comprises Santa Ana, Izalco, and Cerro Verde stratovolcanoes, the Coatepeque collapse caldera, as well as several cinder cones and explosion craters. Most recent activity has occurred at Izalco (1966) and Santa Ana which shows a permanent acidic crater lake with an intense fumarolic activity. In addition, Santa Ana exhibits a SO2-rich rising plume though no local seismicity has been reported. Weak fumarolic activity is also present at two locations within the Santa Ana volcanic complex: the summit crater of Izalco and Cerro Pacho at Coatepeque caldera. Other important structural features of this volcanic complex are two fault/fissure systems running NNW-SSE that can be identified by the alignment of the stratovolcanoes and numerous cinder cones and explosion craters. In January 2001, a 7.6 magnitude earthquake occurred about 150 Km SE of Santa Ana volcano. A soil gas and CO2 efflux survey was performed to evaluate the impact of this seismic event upon the diffuse degassing rates in Santa Ana volcanic complex in March 2001. A total of 450 soil gas and diffuse CO2 efflux measurements were carried out covering an area of 209.5 Km2. CO2 efflux ranged from non-detectable values to 293 gm-2d-1, with a median of 8.9 gm-2d-1 and an upper quartile of 5.2 gm-2d-1. The CO2 efflux spatial distribution reveals the existence of areas with CO2 efflux higher than 60 gm-2d-1 associated to the fault/fissure systems of NNW-SSE orientation. One of these areas, Cerro Pacho, was selected for the continuous monitoring of diffuse CO2 efflux in late May 2001. Secular variations of diffuse CO2 efflux ranged from 27.4 to 329 gm-2d-1 with a median of 130 gm-2d-1 and a quartile range of 59.3 gm-2d-1. An increasing trend of 43 gm-2d-1 was observed between May and August 2001 overlapped to high-frequency minor fluctuations related to meteorological variables' changes. However, a larger observation time-span is needed to

  20. Geochemical Study of Natural CO2 Emissions in the French Massif Central: How to Predict Origin, Processes and Evolution of CO2 Leakage Étude géochimique des émissions naturelles de CO2 du Massif Central : origine et processus de migration du gaz

    Directory of Open Access Journals (Sweden)

    Battani A.

    2010-05-01

    Full Text Available This study presents an overview of some results obtained within the French ANR (National Agency of Research supported Géocarbone-Monitoring research program. The measurements were performed in Sainte-Marguerite, located in the French Massif Central. This site represents a natural laboratory for CO2/fluid/rock interactions studies, as well as CO2 migration mechanisms towards the surface. The CO2 leaking character of the studied area also allows to test and validate measurements methods and verifications for the future CO2 geological storage sites. During these surveys, we analyzed soil CO2 fluxes and concentrations. We sampled and analyzed soil gases, and gas from carbo-gaseous bubbling springs. A one-month continuous monitoring was also tested, to record the concentration of CO2 both in atmosphere and in the soil at a single point. We also developed a new methodology to collect soil gas samples for noble gas abundances and isotopic analyses, as well as carbon isotopic ratios. Our geochemical results, combined with structural geology, show that the leaking CO2 has a very deep origin, partially mantle derived. The gas rises rapidly along normal and strike-slip active faults. CO2 soil concentrations (also showing a mantle derived component and CO2 fluxes are spatially variable, and reach high values. The recorded atmospheric CO2 is not very high, despite the important CO2 degassing throughout the whole area. Cette étude présente les principaux résultats de campagnes de monitoring géochimique menées en 2006 et 2007 dans le cadre du projet Géocarbone-Monitoring, sur le site de Sainte-Marguerite, situé dans le Massif Central. Ce site constitue un « laboratoire naturel » pour l’étude des interactions CO2/fluides/roches et des mécanismes de migration du CO2 vers la surface, à l’échelle des temps géologiques. Le caractère particulièrement émissif de cet « analogue » permet également de tester et valider des méthodes de mesure et

  1. Duration of hydrothermal treatment and peeling of 'Murcott' tangor

    Directory of Open Access Journals (Sweden)

    Ana Luiza Pinheiro

    2011-12-01

    Full Text Available Hydrothermal treatment facilitates the peeling of 'Pera' sweet orange fruit and does not alter its quality. The aim of this work was to adapt the technology of peeling for the use of hydrothermal treatment in 'Murcott' tangor and to evaluate its influence in the CO2 production and the physicochemical, microbiologic and sensorial characteristics of fruits. The peeling time, the yield of marketable fruits and the internal temperature of fruits during the treatment were also evaluated. The hydrothermal treatment consisted of placing the fruits in a water-bath at 50 ºC for 5, 10, 15, 20, 25 and 30 min. Fruits were peeled by first opening a gap in the peduncle region with a knife and then manually removing the flavedo and albedo. Fruits were stored at 5 ºC for six days. Hydrothermal treatment caused changes in the fruits' CO2 production for only the first few hours after processing. Internal fruit temperature after 30 min of treatment reached 35 ºC. There were no changes in the physicochemical and microbiologic characteristics of the fruits. The treatment did not change the flavor, improved the fruits' appearance, decreased the peeling time of the treated fruits by 57 % and increased the yield of marketable fruits. In conclusion, the hydrothermal treatment accomplished from 5 to 30 min at 50 ºC can be used as part of the peeling process for 'Murcott' tangor.

  2. Metabolic effects of Carbon Dioxide (CO 2 ) insufflation during ...

    African Journals Online (AJOL)

    Metabolic effects of Carbon Dioxide (CO 2 ) insufflation during laparoscopic surgery: changes in pH, arterial partial Pressure of Carbon Dioxide (PaCo 2 ) and End Tidal Carbon Dioxide (EtCO 2 ) ... Respiratory adjustments were done for EtCO2 levels above 60mmHg or SPO2 below 92% or adverse haemodynamic changes.

  3. Characterization of CO2 leakage into the freshwater body

    DEFF Research Database (Denmark)

    Singh, Ashok; Delfs, Jens Olaf; Shao, H.

    2013-01-01

    urrent research into CO2 capture and storage is dominated by improving the CO2 storage capacity. In this context, risk related to CO2 leakage is an important issue which may cause environmental problems, particularly when freshwater resources nearby are intruded by the CO2 plume. In this work...

  4. Flexible and High Performance Supercapacitors Based on NiCo2O4for Wide Temperature Range Applications

    Science.gov (United States)

    Gupta, Ram K.; Candler, John; Palchoudhury, Soubantika; Ramasamy, Karthik; Gupta, Bipin Kumar

    2015-10-01

    Binder free nanostructured NiCo2O4 were grown using a facile hydrothermal technique. X-ray diffraction patterns confirmed the phase purity of NiCo2O4. The surface morphology and microstructure of the NiCo2O4 analyzed by scanning electron microscopy (SEM) showed flower-like morphology composed of needle-like structures. The potential application of binder free NiCo2O4 as an electrode for supercapacitor devices was investigated using electrochemical methods. The cyclic voltammograms of NiCo2O4 electrode using alkaline aqueous electrolytes showed the presence of redox peaks suggesting pseudocapacitance behavior. Quasi-solid state supercapacitor device fabricated by sandwiching two NiCo2O4 electrodes and separating them by ion transporting layer. The performance of the device was tested using cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The device showed excellent flexibility and cyclic stability. The temperature dependent charge storage capacity was measured for their variable temperature applications. Specific capacitance of the device was enhanced by ~150% on raising the temperature from 20 to 60 °C. Hence, the results suggest that NiCo2O4 grown under these conditions could be a suitable material for high performance supercapacitor devices that can be operated at variable temperatures.

  5. Technico-economical assessment of MFI-type zeolite membranes for CO2 capture from post-combustion flue gases

    International Nuclear Information System (INIS)

    Sublet, J.; Pera-Titus, M.; Guilhaume, N.; Farrusseng, D.; Schrive, L.; Chanaud, P.; Siret, B.; Durecu, S.

    2012-01-01

    A detailed survey of the effect of moisture on the CO 2 /N 2 permeation and separation performance of Mobile Five (MFI) zeolite membranes in view of downstream post-combustion CO 2 capture applications in power plants and incinerators is presented. The membranes, displaying a nano-composite architecture, have been prepared on α-alumina tubes by pore-plugging hydrothermal synthesis at 443 K for 89 h using a precursor clear solution with molar composition 1 SiO 2 :0.45 tetrapropylammonium hydroxide:27.8 H 2 O. The synthesized membranes present reasonable permeation and CO 2 /N 2 separation properties even in the presence of high water concentrations in the gas stream. A critical discussion is also provided on the technico-economical feasibility (i.e., CO 2 recovery, CO 2 purity in the permeate, module volume, and energy consumption) of a membrane cascade unit for CO 2 capture and liquefaction/supercritical storage from standard flue gases emitted from an incinerator. Our results suggest that the permeate pressure should be kept under primary vacuum to promote the CO 2 driving force within the membrane. (authors)

  6. PLAINS CO2 REDUCTION (PCOR) PARTNERSHIP

    Energy Technology Data Exchange (ETDEWEB)

    Edward N. Steadman; Daniel J. Daly; Lynette L. de Silva; John A. Harju; Melanie D. Jensen; Erin M. O' Leary; Wesley D. Peck; Steven A. Smith; James A. Sorensen

    2006-01-01

    During the period of October 1, 2003, through September 30, 2005, the Plains CO2 Reduction (PCOR) Partnership, identified geologic and terrestrial candidates for near-term practical and environmentally sound carbon dioxide (CO2) sequestration demonstrations in the heartland of North America. The PCOR Partnership region covered nine states and three Canadian provinces. The validation test candidates were further vetted to ensure that they represented projects with (1) commercial potential and (2) a mix that would support future projects both dependent and independent of CO2 monetization. This report uses the findings contained in the PCOR Partnership's two dozen topical reports and half-dozen fact sheets as well as the capabilities of its geographic information system-based Decision Support System to provide a concise picture of the sequestration potential for both terrestrial and geologic sequestration in the PCOR Partnership region based on assessments of sources, sinks, regulations, deployment issues, transportation, and capture and separation. The report also includes concise action plans for deployment and public education and outreach as well as a brief overview of the structure, development, and capabilities of the PCOR Partnership. The PCOR Partnership is one of seven regional partnerships under Phase I of the U.S. Department of Energy National Energy Technology Laboratory's Regional Carbon Sequestration Partnership program. The PCOR Partnership, comprising 49 public and private sector members, is led by the Energy & Environmental Research Center at the University of North Dakota. The international PCOR Partnership region includes the Canadian provinces of Alberta, Saskatchewan, and Manitoba and the states of Montana (part), Wyoming (part), North Dakota, South Dakota, Nebraska, Missouri, Iowa, Minnesota, and Wisconsin.

  7. 2D and 3D high resolution seismic imaging of shallow Solfatara crater in Campi Flegrei (Italy): new insights on deep hydrothermal fluid circulation processes

    Science.gov (United States)

    De Landro, Grazia; Gammaldi, Sergio; Serlenga, Vincenzo; Amoroso, Ortensia; Russo, Guido; Festa, Gaetano; D'Auria, Luca; Bruno, Pier Paolo; Gresse, Marceau; Vandemeulebrouck, Jean; Zollo, Aldo

    2017-04-01

    Seismic tomography can be used to image the spatial variation of rock properties within complex geological media such as volcanoes. Solfatara is a volcano located within the Campi Flegrei still active caldera, characterized by periodic episodes of extended, low-rate ground subsidence and uplift called bradyseism accompanied by intense seismic and geochemical activities. In particular, Solfatara is characterized by an impressive magnitude diffuse degassing, which underlines the relevance of fluid and heat transport at the crater and prompted further research to improve the understanding of the hydrothermal system feeding the surface phenomenon. In this line, an active seismic experiment, Repeated Induced Earthquake and Noise (RICEN) (EU Project MEDSUV), was carried out between September 2013 and November 2014 to provide time-varying high-resolution images of the structure of Solfatara. In this study we used the datasets provided by two different acquisition geometries: a) A 2D array cover an area of 90 x 115 m ^ 2 sampled by a regular grid of 240 vertical sensors deployed at the crater surface; b) two 1D orthogonal seismic arrays deployed along NE-SW and NW-SE directions crossing the 400 m crater surface. The arrays are sampled with a regular line of 240 receiver and 116 shots. We present 2D and 3D tomographic high-resolution P-wave velocity images obtained using two different tomographic methods adopting a multiscale strategy. The 3D image of the shallow (30-35 m) central part of Solfatara crater is performed through the iterative, linearized, tomographic inversion of the P-wave first arrival times. 2D P-wave velocity sections (60-70 m) are obtained using a non-linear travel-time tomography method based on the evaluation of a posteriori probability density with a Bayesian approach. The 3D retrieved images integrated with resistivity section and temperature and CO2 flux measurements , define the following characteristics: 1. A depth dependent P-wave velocity layer

  8. Effects of atmospheric CO2 enrichment on soil CO2 efflux in a young longleaf pine system

    Science.gov (United States)

    Elevated atmospheric carbon dioxide (CO2) can affect the quantity and quality of plant tissues which will impact carbon (C) cycling and storage in plant/soil systems and the release of CO2 back to the atmosphere. Research is needed to quantify the effects of elevated CO2 on soil CO2 efflux to predi...

  9. Reconsideration of atmospheric CO2 lifetime: potential mechanism for explaining CO2 missing sink

    Science.gov (United States)

    Kikuchi, R.; Gorbacheva, T.; Gerardo, R.

    2009-04-01

    Carbon cycle data (Intergovernmental Panel on Climate Change 1996) indicate that fossil fuel use accounts for emissions to the atmosphere of 5.5±0.5 GtC (Gigatons of carbon) annually. Other important processes in the global CO2 budget are tropical deforestation, estimated to generate about 1.6±1.0 GtC/yr; absorption by the oceans, removing about 2.0±0.8 GtC/yr; and regrowth of northern forests, taking up about 0.5±0.5 GtC/yr. However, accurate measurements of CO2 show that the atmosphere is accumulating only about 3.3±0.2 GtC/yr. The imbalance of about 1.3±1.5 GtC/yr, termed the "missing sink", represents the difference between the estimated sources and the estimated sinks of CO2; that is, we do not know where all of the anthropogenic CO2 is going. Several potential mechanisms have been proposed to explain this missing carbon, such as CO2 fertilization, climate change, nitrogen deposition, land use change, forest regrowth et al. Considering the complexity of ecosystem, most of ecosystem model cannot handle all the potential mechanisms to reproduce the real world. It has been believed that the dominant sink mechanism is the fertilizing effects of increased CO2 concentrations in the atmosphere and the addition to soils of fixed nitrogen from fossil-fuel burning and agricultural fertilizers. However, a recent analysis of long-term observations of the change in biomass and growth rates suggests that such fertilization effects are much too small to explain more than a small fraction of the observed sink. In addition, long-term experiments in which small forest patches and other land ecosystems have been exposed to elevated CO2 levels for extended periods show a rapid decrease of the fertilization effect after an initial enhancement. We will explore this question of the missing sink in atmospheric CO2 residence time. Radioactive and stable carbon isotopes (13-C/12-C) show the real CO2 lifetime is about 5 years; i.e. CO2 is quickly taken out of the atmospheric

  10. Interactions between CO2, saline water and minerals during geological storage of CO2

    International Nuclear Information System (INIS)

    Hellevang, Helge

    2006-06-01

    The topic of this thesis is to gain a better understanding of interactions between injected CO 2 , aqueous solutions and formation mineralogies. The main focus is concerned with the potential role mineral reactions play in safe long term storage of CO 2 . The work is divided into an experimental part concentrated on the potential of dawsonite (NaAl(OH) 2 CO 3 ) as a permanent storage host of CO 2 , and the development of a new geochemical code ACCRETE that is coupled with the ATHENA multiphase flow simulator. The thesis is composed of two parts: (I) the first part introducing CO 2 storage, geochemical interactions and related work; and (II) the second part that consists of the papers. Part I is composed as follows: Chapter 2 gives a short introduction to geochemical reactions considered important during CO 2 storage, including a thermodynamic framework. Chapter 3 presents objectives of numerical work related to CO 2 -water-rock interactions including a discussion of factors that influence the outcome of numerical simulations. Chapter 4 presents the main results from paper A to E. Chapter 5 give some details about further research that we propose based on the present work and related work in the project. Several new activities have emerged from research on CO 2 -water-rock interaction during the project. Several of the proposed activities are already initiated. Papers A to F are then listed in Part II of the thesis after the citation list. The thesis presents the first data on the reaction kinetics of dawsonite at different pH (Paper A), and comprehensive numerical simulations, both batch- and large scale 3D reactive transport, that illustrate the role different carbonates have for safe storage of CO 2 in geological formations (Papers C to F). The role of dawsonite in CO 2 storage settings is treated throughout the study (Papers A to E) After the main part of the thesis (Part I and II), two appendices are included: Appendix A lists reactions that are included in the

  11. Stable isotope measurements of atmospheric CO2

    International Nuclear Information System (INIS)

    White, J.W.C.; Ferretti, D.F.; Vaughn, B.H.; Francey, R.J.; Allison, C.E.

    2002-01-01

    The measurement of stable carbon isotope ratios of atmospheric carbon dioxide, δ 13 CO 2 are useful for partitioning surface-atmospheric fluxes into terrestrial and oceanic components. δC 18 OO also has potential for segregating photosynthetic and respiratory fluxes in terrestrial ecosystems. Here we describe in detail the techniques for making these measurements. The primary challenge for all of the techniques used to measure isotopes of atmospheric CO 2 is to achieve acceptable accuracy and precision and to maintain them over the decades needed to observe carbon cycle variability. The keys to success such an approach are diligent intercalibrations of laboratories from around the world, as well as the use of multiple techniques such as dual inlet and GC-IRMS and the intercomparison of such measurements. We focus here on two laboratories, the Stable Isotope Lab at the Institute for Arctic and Alpine Research (INSTAAR) at the University of Colorado is described and the Commonwealth Scientific and Industrial Research Organisation - Atmospheric Research (CSIRO). Different approaches exist at other laboratories (e.g. programs operated by Scripps Institution of Oceanography (SIO) and The Center for Atmospheric and Oceanic Studies, Toboku University (TU)) however these are not discussed here. Finally, we also discuss the recently developed Gas Chromatography - Isotope Ratio Mass Spectrometry (GC-IRMS) technique which holds significant promise for measuring ultra-small samples of gas with good precision. (author)

  12. CO2 reduction through energy conservation

    International Nuclear Information System (INIS)

    1991-05-01

    A study was carried out of the potential to economically reduce carbon dioxide emissions through energy conservation in the petroleum and natural gas industry. The study examined current and projected emissions levels, cogeneration at gas plants, flaring, economics, regulation, reporting requirements, implementation, and research and development. Economically attractive energy conservation measures can reduce oil and gas industry, exclusive of Athabasca oil sands operations, CO 2 emissions by 6-7%. The energy conservation options identified range from field energy awareness committees through to equipment retrofits and replacement. At ca 3 million tonnes/y, these reductions will not offset the increases in oil and gas related CO 2 emissions anticipated by producers and Alberta government agencies. There will be increasing emphasis on in-situ bitumen production, more energy intensive light crude oil production and increasing natural gas sales, increasing energy inputs in excess of reductions. Cogeneration of electricity for utility company distribution and for internally required steam at gas plants and in-situ production sites is not economic due to low electricity prices. 8 tabs

  13. Global CO2 emissions from cement production

    Science.gov (United States)

    Andrew, Robbie M.

    2018-01-01

    The global production of cement has grown very rapidly in recent years, and after fossil fuels and land-use change, it is the third-largest source of anthropogenic emissions of carbon dioxide. The required data for estimating emissions from global cement production are poor, and it has been recognised that some global estimates are significantly inflated. Here we assemble a large variety of available datasets and prioritise official data and emission factors, including estimates submitted to the UNFCCC plus new estimates for China and India, to present a new analysis of global process emissions from cement production. We show that global process emissions in 2016 were 1.45±0.20 Gt CO2, equivalent to about 4 % of emissions from fossil fuels. Cumulative emissions from 1928 to 2016 were 39.3±2.4 Gt CO2, 66 % of which have occurred since 1990. Emissions in 2015 were 30 % lower than those recently reported by the Global Carbon Project. The data associated with this article can be found at https://doi.org/10.5281/zenodo.831455.

  14. Public Acceptance for Geological CO2-Storage

    Science.gov (United States)

    Schilling, F.; Ossing, F.; Würdemann, H.; Co2SINK Team

    2009-04-01

    Public acceptance is one of the fundamental prerequisites for geological CO2 storage. In highly populated areas like central Europe, especially in the vicinity of metropolitan areas like Berlin, underground operations are in the focus of the people living next to the site, the media, and politics. To gain acceptance, all these groups - the people in the neighbourhood, journalists, and authorities - need to be confident of the security of the planned storage operation as well as the long term security of storage. A very important point is to show that the technical risks of CO2 storage can be managed with the help of a proper short and long term monitoring concept, as well as appropriate mitigation technologies e.g adequate abandonment procedures for leaking wells. To better explain the possible risks examples for leakage scenarios help the public to assess and to accept the technical risks of CO2 storage. At Ketzin we tried the following approach that can be summed up on the basis: Always tell the truth! This might be self-evident but it has to be stressed that credibility is of vital importance. Suspiciousness and distrust are best friends of fear. Undefined fear seems to be the major risk in public acceptance of geological CO2-storage. Misinformation and missing communication further enhance the denial of geological CO2 storage. When we started to plan and establish the Ketzin storage site, we ensured a forward directed communication. Offensive information activities, an information centre on site, active media politics and open information about the activities taking place are basics. Some of the measures were: - information of the competent authorities through meetings (mayor, governmental authorities) - information of the local public, e.g. hearings (while also inviting local, regional and nation wide media) - we always treated the local people and press first! - organizing of bigger events to inform the public on site, e.g. start of drilling activities (open

  15. Remaining gaps for "safe" CO2 storage: the INGV CO2GAPS vision of "learning by doing" monitoring geogas leakage, reservoirs contamination/mixing and induced/triggered seismicity

    Science.gov (United States)

    Quattrocchi, F.; Vinciguerra, S.; Chiarabba, C.; Boschi, E.; Anselmi, M.; Burrato, P.; Buttinelli, M.; Cantucci, B.; Cinti, D.; Galli, G.; Improta, L.; Nazzari, M.; Pischiutta, M.; Pizzino, L.; Procesi, M.; Rovelli, A.; Sciarra, A.; Voltattorni, N.

    2012-12-01

    The CO2GAPS project proposed by INGV is intended to build up an European Proposal for a new kind of research strategy in the field of the geogas storage. Aim of the project would be to fill such key GAPS concerning the main risks associated to CO2 storage and their implications on the entire Carbon Capture and Storage (CCS) process, which are: i) the geogas leakage both in soils and shallow aquifers, up to indoor seepage; ii) the reservoirs contamination/mixing by hydrocarbons and heavy metals; iii) induced or triggered seismicity and microseismicity, especially for seismogenic blind faults. In order to consider such risks and make the CCS public acceptance easier, a new kind of research approach should be performed by: i) a better multi-disciplinary and "site specific" risk assessment; ii) the development of more reliable multi-disciplinary monitoring protocols. In this view robust pre-injection base-lines (seismicity and degassing) as well as identification and discrimination criteria for potential anomalies are mandatory. CO2 injection dynamic modelling presently not consider reservoirs geomechanical properties during reactive mass-transport large scale simulations. Complex simulations of the contemporaneous physic-chemical processes involving CO2-rich plumes which move, react and help to crack the reservoir rocks are not totally performed. These activities should not be accomplished only by the oil-gas/electric companies, since the experienced know-how should be shared among the CCS industrial operators and research institutions, with the governments support and overview, also flanked by a transparent and "peer reviewed" scientific popularization process. In this context, a preliminary and reliable 3D modelling of the entire "storage complex" as defined by the European Directive 31/2009 is strictly necessary, taking into account the above mentioned geological, geochemical and geophysical risks. New scientific results could also highlighting such opportunities

  16. Improvement in a degassing chamber with continuous operation and arrangement for distillation sublimation, etc

    Energy Technology Data Exchange (ETDEWEB)

    Lurmann, F

    1881-05-25

    The degassing chambers shown in Patent 13,021 are combined with a receiver. Through arrangement of more roomy sucking openings for the distillation products, a continual partial recovery of the coke oven gases rich in different valuable constituents is attained. Arches lie over the degassing chamber and extend to the gas-burning rooms; to prevent their burning through. They remain directly in communication with the atmosphere and are on the top of the gasification room above the final arches. The charging of the various degassing rooms can be carried out by the usual charging apparatus, which runs lengthwise on rails on the degassing chambers.

  17. Graben structure in the Las Cañadas edifice (Tenerife, Canary Islands): implications for active degassing and insights on the caldera formation

    Science.gov (United States)

    Galindo, Inés; Soriano, Carles; Martí, Joan; Pérez, Nemesio

    2005-06-01

    A graben structure has been identified at the western area of the Las Cañadas caldera wall, here referred as the Los Azulejos Graben. This graben is 1 km wide and is bounded by two major normal faults trending NE-SW, the Los Azulejos Fault and the Ucanca Fault. The graben was active for at least 0.5 Ma, from the end of the Ucanca Fm to the end of the Guajara Fm, and before the collapse of the Las Cañadas edifice that formed the western caldera. A right-lateral transtension regime operated in the graben as suggested by small fault orientations and kinematics. The prolongation of the NE rift zone of Tenerife to the Cañadas edifice is the most likely volcano-tectonic scenario for the graben. In this context, inflation of phonolitic shallow magma chambers may have produced reverse faults and reactivation of normal faults. An intense and widespread hydrothermal alteration, here called Azulejos-type, occurred mainly before the graben formation, while a fault-related hydrothermal alteration occurred during and after the graben. Diffuse carbon dioxide and hydrogen degassing in and around the Las Cañadas caldera show relatively enriched values along a NE-SW trend suggesting that faults in the Los Azulejos Graben act as a pathway for deep-seated gases to the surface. Diffuse degassing and hydrothermalism indicate that the graben area has been a zone of intense fluid circulation during the evolution of the Las Cañadas edifice.

  18. Field demonstration of CO2 leakage detection in potable aquifers with a pulselike CO2-release test.

    Science.gov (United States)

    Yang, Changbing; Hovorka, Susan D; Delgado-Alonso, Jesus; Mickler, Patrick J; Treviño, Ramón H; Phillips, Straun

    2014-12-02

    This study presents two field pulselike CO2-release tests to demonstrate CO2 leakage detection in a shallow aquifer by monitoring groundwater pH, alkalinity, and dissolved inorganic carbon (DIC) using the periodic groundwater sampling method and a fiber-optic CO2 sensor for real-time in situ monitoring of dissolved CO2 in groundwater. Measurements of groundwater pH, alkalinity, DIC, and dissolved CO2 clearly deviated from their background values, showing responses to CO2 leakage. Dissolved CO2 observed in the tests was highly sensitive in comparison to groundwater pH, DIC, and alkalinity. Comparison of the pulselike CO2-release tests to other field tests suggests that pulselike CO2-release tests can provide reliable assessment of geochemical parameters indicative of CO2 leakage. Measurements by the fiber-optic CO2 sensor, showing obvious leakage signals, demonstrated the potential of real-time in situ monitoring of dissolved CO2 for leakage detection at a geologic carbon sequestration (GCS) site. Results of a two-dimensional reactive transport model reproduced the geochemical measurements and confirmed that the decrease in groundwater pH and the increases in DIC and dissolved CO2 observed in the pulselike CO2-release tests were caused by dissolution of CO2 whereas alkalinity was likely affected by carbonate dissolution.

  19. Response of atmospheric CO2 to changes in land use

    International Nuclear Information System (INIS)

    King, A.W.; Emanuel, W.R.; Post, W.M.

    1991-01-01

    This chapter examines how different histories of CO 2 release from past changes in land use influence the simulation of past and future changes in atmospheric CO 2 . The authors first simulate past change in atmospheric CO 2 using reconstructed histories of land-use CO 2 release from a historical-ecological model of land-use change and CO 2 release. They examine the impact of each history on the coincidence between simulated and observed atmospheric CO 2 . They then compare these CO 2 release histories, and their contribution to coincidence or noncoincidence of simulation and observation, with histories reconstructed by deconvolution of the atmospheric CO 2 record. They conclude by exploring the implications of these deconvolved reconstructions for the simulation of future changes in atmospheric CO 2

  20. CO2 Emissions from Fuel Combustion 2011: Highlights

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    How much CO2 are countries emitting? Where is it coming from? In the lead-up to the UN climate negotiations in Durban, the latest information on the level and growth of CO2 emissions, their source and geographic distribution will be essential to lay the foundation for a global agreement. To provide input to and support for the UN process the IEA is making available for free download the 'Highlights' version of CO2 Emissions from Fuel Combustion. This annual publication contains: - estimates of CO2 emissions by country from 1971 to 2009; - selected indicators such as CO2/GDP, CO2/capita, CO2/TPES and CO2/kWh; - CO2 emissions from international marine and aviation bunkers, and other relevant information. These estimates have been calculated using the IEA energy databases and the default methods and emission factors from the Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories.

  1. CO2 Emissions from Fuel Combustion - 2012 Highlights

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    How much CO2 are countries emitting? Where is it coming from? In the lead-up to the UN climate negotiations in Doha, the latest information on the level and growth of CO2 emissions, their source and geographic distribution will be essential to lay the foundation for a global agreement. To provide input to and support for the UN process the IEA is making available for free download the 'Highlights' version of CO2 Emissions from Fuel Combustion. This annual publication contains: estimates of CO2 emissions by country from 1971 to 2010; selected indicators such as CO2/GDP, CO2/capita, CO2/TPES and CO2/kWh; and CO2 emissions from international marine and aviation bunkers, and other relevant information.

  2. CO2 Emissions from Fuel Combustion 2011: Highlights

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    How much CO2 are countries emitting? Where is it coming from? In the lead-up to the UN climate negotiations in Durban, the latest information on the level and growth of CO2 emissions, their source and geographic distribution will be essential to lay the foundation for a global agreement. To provide input to and support for the UN process the IEA is making available for free download the 'Highlights' version of CO2 Emissions from Fuel Combustion. This annual publication contains: - estimates of CO2 emissions by country from 1971 to 2009; - selected indicators such as CO2/GDP, CO2/capita, CO2/TPES and CO2/kWh; - CO2 emissions from international marine and aviation bunkers, and other relevant information. These estimates have been calculated using the IEA energy databases and the default methods and emission factors from the Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories.

  3. CO2 Emissions from Fuel Combustion - 2012 Highlights

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    How much CO2 are countries emitting? Where is it coming from? In the lead-up to the UN climate negotiations in Doha, the latest information on the level and growth of CO2 emissions, their source and geographic distribution will be essential to lay the foundation for a global agreement. To provide input to and support for the UN process the IEA is making available for free download the 'Highlights' version of CO2 Emissions from Fuel Combustion. This annual publication contains: estimates of CO2 emissions by country from 1971 to 2010; selected indicators such as CO2/GDP, CO2/capita, CO2/TPES and CO2/kWh; and CO2 emissions from international marine and aviation bunkers, and other relevant information.

  4. Hydrothermal liquefaction of biomass

    DEFF Research Database (Denmark)

    Toor, Saqib; Rosendahl, Lasse; Rudolf, Andreas

    2011-01-01

    This article reviews the hydrothermal liquefaction of biomass with the aim of describing the current status of the technology. Hydrothermal liquefaction is a medium-temperature, high-pressure thermochemical process, which produces a liquid product, often called bio-oil or bi-crude. During...... the hydrothermal liquefaction process, the macromolecules of the biomass are first hydrolyzed and/or degraded into smaller molecules. Many of the produced molecules are unstable and reactive and can recombine into larger ones. During this process, a substantial part of the oxygen in the biomass is removed...... by dehydration or decarboxylation. The chemical properties of bio-oil are highly dependent of the biomass substrate composition. Biomass constitutes of various components such as protein; carbohydrates, lignin and fat, and each of them produce distinct spectra of compounds during hydrothermal liquefaction...

  5. CO2 point sources and subsurface storage capacities for CO2 in aquifers in Norway

    International Nuclear Information System (INIS)

    Boee, Reidulv; Magnus, Christian; Osmundsen, Per Terje; Rindstad, Bjoern Ivar

    2002-01-01

    The GESTCO project comprises a study of the distribution and coincidence of thermal CO 2 emission sources and location/quality of geological storage capacity in Europe. Four of the most promising types of geological storage are being studied. 1. Onshore/offshore saline aquifers with or without lateral seal. 2. Low entalpy geothermal reservoirs. 3. Deep methane-bearing coal beds and abandoned coal and salt mines. 4. Exhausted or near exhausted hydrocarbon structures. In this report we present an inventory of CO 2 point sources in Norway (1999) and the results of the work within Study Area C: Deep saline aquifers offshore/near shore Northern and Central Norway. Also offshore/near shore Southern Norway has been included while the Barents Sea is not described in any detail. The most detailed studies are on the Tilje and Aare Formations on the Troendelag Platform off Mid-Norway and on the Sognefjord, Fensfjord and Krossfjord Formations, southeast of the Troll Field off Western Norway. The Tilje Formation has been chosen as one of the cases to be studied in greater detail (numerical modelling) in the project. This report shows that offshore Norway, there are concentrations of large CO 2 point sources in the Haltenbanken, the Viking Graben/Tampen Spur area, the Southern Viking Graben and the central Trough, while onshore Norway there are concentrations of point sources in the Oslofjord/Porsgrund area, along the coast of western Norway and in the Troendelag. A number of aquifers with large theoretical CO 2 storage potential are pointed out in the North Sea, the Norwegian Sea and in the Southern Barents Sea. The storage capacity in the depth interval 0.8 - 4 km below sea level is estimated to be ca. 13 Gt (13000000000 tonnes) CO 2 in geological traps (outside hydrocarbon fields), while the storage capacity in aquifers not confined to traps is estimated to be at least 280 Gt CO 2 . (Author)

  6. Plasma catalytic process for CO2 methanation

    International Nuclear Information System (INIS)

    Nizio, Magdalena

    2016-01-01

    The limited resources of oil and natural gas, together with an increasing energy demand, forces us to seek more and more efficient and cleaner energy production alternatives. Hydrogen has been recently considered as a promising energy carrier. However, there are several inherent problems to the utilization of H 2 , from its transportation to its distribution. Transformation of the H 2 molecule by fixing into a carbon-containing compound, i.e. CH 4 , will offer the possibility of using the conventional transportation network. Indeed, the Sabatier reaction, which is highly exothermic, involves the reaction of carbon dioxide and hydrogen gas in order to produce methane and water. This process, called methanation, represents a feasible approach contributing to the reduction of the CO 2 emissions in our atmosphere, through a closed carbon cycle involving the valorization of CO 2 , i.e. from capture. However, below a temperature of 250 C, the conversion becomes practically close to 0 %, whereas at higher temperatures, i.e., (≥300 C), the co-existence of secondary reactions favours the formation of CO and H 2 . This is the reason why new catalysts and process conditions are continuously being investigated in order to maximize the methane selectivity at low reaction temperatures at atmospheric pressure. Therefore, by using catalysts combined to Dielectric Barrier Discharge plasmas (DBD), the activation of the methanation reaction can be enhanced and overcome the drawbacks of existing conventional processes. Several Ni-containing catalysts were prepared using various ceria-zirconia oxides as supports, with different Ce/Zr ratios. The results obtained in the adiabatic conditions at low temperatures (ranging between 100-150 C), in the presence of catalysts activated by plasma, are promising. Indeed, the conversion of CO 2 to CH 4 is about 85 % with a selectivity close to 100 %. The same conversion in the absence of the plasma activation of the catalyst is observed at 350 C

  7. Process for water-gas generation from degassed combustibles

    Energy Technology Data Exchange (ETDEWEB)

    1906-05-23

    A process for water-gas generation in a continuous operation from degassed combustibles in the lower part of a vertical exterior-heated retort, whose middle part can serve to degas the combustibles, is described. It is characterized in that the water vapor employed is obtained by vaporizing water in the upper part of the retort by means of the waste heat from the heating gases, which had effected the coking of the combustibles before the water-gas recovery or after the latter.

  8. Carbon dioxide degassing in fresh and saline water. II: Degassing performance of an air-lift

    DEFF Research Database (Denmark)

    Moran, Damian

    2010-01-01

    A study was undertaken to measure the efficiency with which carbon dioxide was stripped from freshwater (0‰) and saline water (35‰ NaCl) passing through an air-lift at 15 °C. The air-lift was constructed of 50 mm (OD) PVC pipe submerged 95 cm in a tank, had an adjustable air injection rate, and c...... for any water type (i.e. temperature, alkalinity, salinity and influent CO2 concentration).......A study was undertaken to measure the efficiency with which carbon dioxide was stripped from freshwater (0‰) and saline water (35‰ NaCl) passing through an air-lift at 15 °C. The air-lift was constructed of 50 mm (OD) PVC pipe submerged 95 cm in a tank, had an adjustable air injection rate......, and could be adjusted to three lifting heights: 11, 16 and 25 cm. The gas to liquid ratio (G:L) was high (1.9–2.0) at low water discharge rates (Qw) and represented the initial input energy required to raise the water up the vertical riser section to the discharge pipe. The air-lift increased in pumping...

  9. Plasma Arc Augmented CO2 laser welding

    DEFF Research Database (Denmark)

    Bagger, Claus; Andersen, Mikkel; Frederiksen, Niels

    2001-01-01

    In order to reduce the hardness of laser beam welded 2.13 mm medium strength steel CMn 250, a plasma arc has been used simultaneously with a 2.6 kW CO2 laser source. In a number of systematic laboratory tests, the plasma arc current, plasma gas flow and distance to the laser source were varied...... with all laser parameters fixed. The welds were quality assessed and hardness measured transversely to the welding direction in the top, middle and root of the seam. In the seams welded by laser alone, hardness values between 275 and 304 HV1 were measured, about the double of the base material, 150 HV1...

  10. Tritium removal by CO2 laser heating

    International Nuclear Information System (INIS)

    Skinner, C.H.; Kugel, H.; Mueller, D.

    1997-01-01

    Efficient techniques for rapid tritium removal will be necessary for ITER to meet its physics and engineering goals. One potential technique is transient surface heating by a scanning CO 2 or Nd:Yag laser that would release tritium without the severe engineering difficulties of bulk heating of the vessel. The authors have modeled the heat propagation into a surface layer and find that a multi-kW/cm 2 flux with an exposure time of order 10 ms is suitable to heat a 50 micron co-deposited layer to 1,000--2,000 degrees. Improved wall conditioning may be a significant side benefit. They identify remaining issues that need to be addressed experimentally

  11. Tritium removal by CO2 laser heating

    International Nuclear Information System (INIS)

    Skinner, C.H.; Kugel, H.; Mueller, D.

    1997-10-01

    Efficient techniques for rapid tritium removal will be necessary for ITER (International Thermonuclear Experimental Reactor) to meet its physics and engineering goals. One potential technique is transient surface heating by a scanning CO 2 or Nd:YAG laser that would release tritium without the severe engineering difficulties of bulk heating of the vessel. The authors have modeled the heat propagation into a surface layer and find that a multi-kW/cm 2 flux with an exposure time of order 10 msec is suitable to heat a 50 micron co-deposited layer to 1,000--2,000 degrees. Improved wall conditioning may be a significant side benefit. They identify remaining issues that need to be addressed experimentally

  12. CO2 Capture for Cement Technology

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar

    , whereas in a normal cement plant, it is 0.9 kg/ kg cl. However the thermal energy demand in the integrated plant increases from 3.9 MJ/ kg cl to 5.6 MJ/ kg cl. But on the other side this additional energy spent can be recovered as a high quality heat to generate electricity. The potential to generate...... electricity depends on the scale of the plant, the bigger the production capacity of cement plant the better, with capacity higher than 3400 tons of clinker/day is required to produce captive electricity to meet the demand both from the cement plant operations and from the CO2 capture system operations....

  13. Smart Transportation CO2 Emission Reduction Strategies

    Science.gov (United States)

    Tarulescu, S.; Tarulescu, R.; Soica, A.; Leahu, C. I.

    2017-10-01

    Transport represents the sector with the fastest growing greenhouse gas emissions around the world. The main global objective is to reduce energy usage and associated greenhouse gas emissions from the transportation sector. For this study it was analyzed the road transportation system from Brasov Metropolitan area. The study was made for the transportation route that connects Ghimbav city to the main surrounding objectives. In this study ware considered four optimization measures: vehicle fleet renewal; building the detour belt for the city; road increasing the average travel speed; making bicycle lanes; and implementing an urban public transport system for Ghimbav. For each measure it was used a mathematical model to calculate the energy consumption and carbon emissions from the road transportation sector. After all four measures was analyzed is calculated the general energy consumption and CO2 reduction if this are applied from year 2017 to 2020.

  14. Power stabilized CO2 gas transport laser

    International Nuclear Information System (INIS)

    Foster, J.D.; Kirk, R.F.; Moreno, F.E.; Ahmed, S.A.

    1975-01-01

    The output power of a high power (1 kW or more) CO 2 gas transport laser is stabilized by flowing the gas mixture over copper plated baffles in the gas channel during operation of the laser. Several other metals may be used instead of copper, for example, nickel, manganese, palladium, platinum, silver and gold. The presence of copper in the laser gas circuit stabilizes output power by what is believed to be a compensation of the chemical changes in the gas due to the cracking action of the electrical discharge which has the effect of diminishing the capactiy of the carbon dioxide gas mixture to maintain the rated power output of the laser. (U.S.)

  15. CO2 laser-aided waste incineration

    International Nuclear Information System (INIS)

    Costes, J.R.; Guiberteau, P.; Caminat, P.; Bournot, P.

    1994-01-01

    Lasers are widely employed in laboratories and in certain industrial applications, notably for welding, cutting and surface treatments. This paper describes a new application, incineration, which appears warranted when the following features are required: high-temperature incineration (> 1500 deg C) with close-tolerance temperature control in an oxidizing medium while ensuring containment of toxic waste. These criteria correspond to the application presented here. Following a brief theoretical introduction concerning the laser/surface interaction, the paper describes the incineration of graphite waste contaminated with alpha-emitting radionuclides. Process feasibility has been demonstrated on a nonradioactive prototype capable of incinerating 10 kg -h-1 using a 7 kW CO 2 laser. An industrial facility with the same capacity, designed to operate within the constraints of an alpha-tight glove box environment, is now at the project stage. Other types of applications with similar requirements may be considered. (authors). 3 refs., 7 figs

  16. US calls for CO2 cut

    International Nuclear Information System (INIS)

    Roberts, M.

    1996-01-01

    The US Government has outraged energy-intensive industries by calling for an international agreement to reduce global emissions of carbon dioxide (CO 2 ) and other greenhouse gases. In a clear policy shift, the US--the world's largest emitter of greenhouse gases and not previously an advocate of curbing them--says it now intends to lead moves to prevent global warming. At last week's Second Conference of the Parties (COP-2) to the United Nations Framework Convention on Climate Change (FCCC), US Undersecretary for Global Affairs Timothy Wirth called for open-quotes an agreement that sets a realistic, verifiable, and binding medium-term emissions target.close quotes Individual countries should be free to choose how to meet targets, and the US favors market-based mechanisms, he says. open-quotes Climate change is a serious problem and will require sustained long-term investment to be addressed successfully,close quotes Wirth says

  17. Anterior capsulotomy using the CO2 laser

    Science.gov (United States)

    Barak, Adiel; Ma-Naim, Tova; Rosner, Mordechai; Eyal, Ophir; Belkin, Michael

    1998-06-01

    Continuous circular capsulorhexis (CCC) is the preferred technique for removal of the anterior capsule during cataract surgery due to this technique assuring accurate centration of the intraocular lens. During modern cataract surgery, especially with small or foldable intra ocular lenses, centration of the lens is obligatory. Radial tears at the margin of an anterior capsulotomy may be associated with the exit of at least one loop of an intraocular lens out of the capsular bag ('pea pod' effect) and its subsequent decentration. The anterior capsule is more likely to ream intact if the continuous circular capsulorhexis (CCC) technique is used. Although manual capsulorhexis is an ideal anterior capsulectomy technique for adults, many ophthalmologists are still uncomfortable with it and find it difficult to perform, especially in complicated cases such as these done behind small pupil, cataract extraction in children and pseudoexfoliation syndrome. We have developed a technique using a CO2 laser system for safe anterior capsulotomy and tested it in animal eyes.

  18. Experimental Investigations into CO2 Interactions with Injection Well Infrastructure for CO2 Storage

    Science.gov (United States)

    Syed, Amer; Shi, Ji-Quan; Durucan, Sevket; Nash, Graham; Korre, Anna

    2013-04-01

    Wellbore integrity is an essential requirement to ensure the success of a CO2 Storage project as leakage of CO2 from the injection or any other abandoned well in the storage complex, could not only severely impede the efficiency of CO2 injection and storage but also may result in potential adverse impact on the surrounding environment. Early research has revealed that in case of improper well completions and/or significant changes in operating bottomhole pressure and temperature could lead to the creation of microannulus at cement-casing interface which may constitute a preferential pathway for potential CO2 leakage during and post injection period. As a part of a European Commission funded CO2CARE project, the current research investigates the sealing behaviour of such microannulus at the cement-casing interface under simulated subsurface reservoir pressure and temperature conditions and uses the findings to develop a methodology to assess the overall integrity of CO2 storage. A full scale wellbore experimental test set up was constructed for use under elevated pressure and temperature conditions as encountered in typical CO2 storage sites. The wellbore cell consists of an assembly of concentric elements of full scale casing (Diameter= 0.1524m), cement sheath and an outer casing. The stainless steel outer ring is intended to simulate the stiffness offered by the reservoir rock to the displacement applied at the wellbore. The Central Loading Mechanism (CLM) consists of four case hardened shoes that can impart radial load onto the well casing. The radial movement of the shoes is powered through the synchronised movement of four precision jacks controlled hydraulically which could impart radial pressures up to 15 MPa. The cell body is a gas tight enclosure that houses the wellbore and the central loading mechanism. The setup is enclosed in a laboratory oven which acts both as temperature and safety enclosure. Prior to a test, cement mix is set between the casing and

  19. CO2 laser milling of hard tissue

    Science.gov (United States)

    Werner, Martin; Ivanenko, Mikhail; Harbecke, Daniela; Klasing, Manfred; Steigerwald, Hendrik; Hering, Peter

    2007-02-01

    Drilling of bone and tooth tissue belongs to recurrent medical procedures (screw- and pin-bores, bores for implant inserting, trepanation etc.). Small round bores can be in general quickly produced with mechanical drills. Problems arise however by angled drilling, by the necessity to fulfill the drilling without damaging of sensitive soft tissue beneath the bone, or by the attempt to mill precisely noncircular small cavities. We present investigations on laser hard tissue "milling", which can be advantageous for solving these problems. The "milling" is done with a CO2 laser (10.6 μm) with pulse duration of 50 - 100 μs, combined with a PC-controlled galvanic beam scanner and with a fine water-spray, which helps to avoid thermal side-effects. The damaging of underlying soft tissue can be prevented through control of the optical or acoustical ablation signal. The ablation of hard tissue is accompanied with a strong glowing, which is absent during the laser beam action on soft tissue. The acoustic signals from the diverse tissue types exhibit distinct differences in the spectral composition. Also computer image analysis could be a useful tool to control the operation. Laser "milling" of noncircular cavities with 1 - 4 mm width and about 10 mm depth is particularly interesting for dental implantology. In ex-vivo investigations we found conditions for fast laser "milling" of the cavities without thermal damage and with minimal tapering. It included exploration of different filling patterns (concentric rings, crosshatch, parallel lines and their combinations), definition of maximal pulse duration, repetition rate and laser power, optimal position of the spray. The optimized results give evidences for the applicability of the CO2 laser for biologically tolerable "milling" of deep cavities in the hard tissue.

  20. Influences of different degassing processes on refining effect and properties of 4004 Al alloy

    Directory of Open Access Journals (Sweden)

    Wang Liping

    2013-03-01

    Full Text Available In order to improve the plasticity of 4004 Al alloy and subsequently the productivity of 4004 Al foil, the research studied in detail the influence of the rotary impeller degassing process on the refining effect of 4004 Al alloy, in which the impacts of four major parameters: gas flow, rotational speed, refining time, and stewing time, on degassing rate of 4004 Al alloy was systematically studied by using an orthogonal experiment methodology. Results show that the rotational speed has the greatest impact on the degassing of 4004 Al alloy, followed by gas flow and refining time; stewing time has the least impact. The optimum purification parameters obtained by current orthogonal analysis were: rotor speed of 500 r·min-1, inert gas flow of 0.4 mL·h-1, refining time of 15 min, and stewing time of 6 min. Degassing rate using the optimum parameters reaches 68%. In addition, the comparison experiments among C2Cl6 refining, rotary impeller degassing, and combined treatment of C2Cl6 refining and rotary impeller degassing for 4004 Al alloy were performed. The experimental data indicated that the combined treatment of C2Cl6 refining and rotary impeller degassing has the best degassing effect. Degassing rate of C2Cl6 refining, rotary impeller degassing and combined refining treatment is 39%, 69.1% and 76.9%, respectively. The mechanical properties of the specimen refined by rotary impeller degassing were higher than those by C2Cl6 refining, but lower than those by combined refining treatment.

  1. Preparation and characterization of self-assembled layer by layer NiCo2O4–reduced graphene oxide nanocomposite with improved electrocatalytic properties

    International Nuclear Information System (INIS)

    Srivastava, Manish; Elias Uddin, Md.; Singh, Jay; Kim, Nam Hoon; Lee, Joong Hee

    2014-01-01

    Graphical abstract: NiCo 2 O 4 were grown on RGO by in situ synthesis process. FE-SEM investigation revealed self assembled layer by layer growth of NiCo 2 O 4 –RGO nanocomposite. NiCo 2 O 4 –RGO nanocomposite exhibited synergetic effect of NiCo 2 O 4 nanoparticles and RGO on its electrochemical performance. -- Highlights: • NiCo 2 O 4 were grown on RGO by in-situ synthesis process. • FE-SEM image revealed self-assembled layer by layer growth of NiCo 2 O 4 -RGO nanocomposite. • NiCo 2 O 4 -RGO nanocomposite exhibited synergetic effects on its electrochemical performance. -- Abstract: NiCo 2 O 4 nanoparticles dispersed on reduced graphene oxide (RGO) are prepared by simultaneously reducing graphene oxide (GO), nickel and cobalt nitrate via a hydrothermal method assisted by post annealing at low temperature. The method involves formation of hydroxides on GO using ammonia under hydrothermal conditions. Subsequent thermal treatment at 300 °C led to the conversion of hydroxides into single-phase NiCo 2 O 4 atop the RGO. The synthesized products are characterized through several techniques including X-ray diffraction (XRD), ultraviolet–visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (RS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The FE-SEM investigations reveal the growth of a layer by layer assembly of NiCo 2 O 4 –RGO (2:1) nanocomposite, where the NiCo 2 O 4 nanoparticles are tightly packed between the layers of RGO. Further, the catalytic properties of the NiCo 2 O 4 –RGO nanocomposite are investigated for the oxygen evolution reaction (OER) through cyclic voltammetry (CV) measurements. It is observed that the special structural features of the NiCo 2 O 4 –RGO (2:1) nanocomposite, including layer by layer assembly, integrity and excellent dispersion of the NiCo 2 O 4 nanoparticles atop the RGO, produced

  2. Dynamics of soil CO2 efflux under varying atmospheric CO2 concentrations reveal dominance of slow processes.

    Science.gov (United States)

    Kim, Dohyoung; Oren, Ram; Clark, James S; Palmroth, Sari; Oishi, A Christopher; McCarthy, Heather R; Maier, Chris A; Johnsen, Kurt

    2017-09-01

    We evaluated the effect on soil CO 2 efflux (F CO 2 ) of sudden changes in photosynthetic rates by altering CO 2 concentration in plots subjected to +200 ppmv for 15 years. Five-day intervals of exposure to elevated CO 2 (eCO 2 ) ranging 1.0-1.8 times ambient did not affect F CO 2 . F CO 2 did not decrease until 4 months after termination of the long-term eCO 2 treatment, longer than the 10 days observed for decrease of F CO 2 after experimental blocking of C flow to belowground, but shorter than the ~13 months it took for increase of F CO 2 following the initiation of eCO 2 . The reduction of F CO 2 upon termination of enrichment (~35%) cannot be explained by the reduction of leaf area (~15%) and associated carbohydrate production and allocation, suggesting a disproportionate contraction of the belowground ecosystem components; this was consistent with the reductions in base respiration and F CO 2 -temperature sensitivity. These asymmetric responses pose a tractable challenge to process-based models attempting to isolate the effect of individual processes on F CO2 . © 2017 John Wiley & Sons Ltd.

  3. Influence of different synthesis approach on ZnCo2O4 nanomaterial and its supercapacitor behavior

    Science.gov (United States)

    Mary, A. Juliet Christina; Thilagavathi, S.; Bose, A. Chandra

    2018-04-01

    ZnCo2O4 nanomaterial was synthesized using three different methods such as, reflux, hydrothermal and sol-gel for supercapacitor application. Structural and morphological studies of the nanomaterial were investigated using XRD and SEM analysis. Electrochemical performance of the material was analyzed using three electrode system. The maximum specific capacitance of ZnCo2O4 nanorod synthesized from the reflux route gave 138 F g-1 at a scan rate of 5 mV s-1 and 126 F g-1 at a current density of 1.5 A g-1. This result suggested that ZnCo2O4 nanomaterial synthesized by reflux method is suitable for supercapacitor application.

  4. Degassing vs. eruptive styles at Mt. Etna volcano (Sicily, Italy): Volatile stocking, gas fluxing, and the shift from low-energy to highly-explosive basaltic eruptions

    Science.gov (United States)

    Moretti, Roberto; Métrich, Nicole; Di Renzo, Valeria; Aiuppa, Alessandro; Allard, Patrick; Arienzo, Ilenia

    2017-04-01

    Basaltic magmas can transport and release large amounts of volatiles into the atmosphere, especially in subduction zones, where slab-derived fluids enrich the mantle wedge. Depending on magma volatile content, basaltic volcanoes thus display a wide spectrum of eruptive styles, from common Strombolian-type activity to Plinian events. Mt. Etna in Sicily, is a typical basaltic volcano where the volatile control on such a variable activity can be investigated. Based on a melt inclusion study in products from Strombolian or lava-fountain activity to Plinian eruptions, here we show that for the same initial volatile content, different eruptive styles reflect variable degassing paths throughout the composite Etnean plumbing system. The combined influence of i) crystallization, ii) deep degassing and iii) CO2 gas fluxing can explain the evolution of H2O, CO2, S and Cl in products from such a spectrum of activity. Deep crystallization produces the CO2-rich gas fluxing the upward magma portions, which will become buoyant and easily mobilized in small gas-rich batches stored within the plumbing system. When reaching gas dominated conditions (i.e., a gas/melt mass ratio of 0.3 and CO2,gas/H2Ogas molar ratio 5 ), these will erupt effusively or mildly explosively, whilst in case of the 122 BC Plinian eruption, open-system degassing conditions took place within