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Sample records for lysimeter co2 gradient

  1. On the Vertical Gradient in CO2

    Science.gov (United States)

    Stine, A. R.; Fung, I. Y.

    2008-12-01

    Attempts to constrain surface fluxes of carbon from atmospheric measurements of carbon dioxide have primarily focused on surface boundary layer measurements, because information about surface fluxes is least diluted close to the locations where the fluxes occur. However, errors in model ventilation of air in the vertical can be misinterpreted as local surface fluxes. Satellites which measure column integrated CO2 are expected to represent a major advance in part because they observe the entire atmospheric column. Recent work has highlighted the fact that vertical gradients in carbon concentrations can give us information about where vertical mixing errors are likely to be misinterpreted as local surface fluxes, but passive tracer evidence suggests that models that capture vertical profiles on the ocean do poorly on the land (and vice versa), suggesting that the problem of correctly treating vertical mixing in inverse studies is more fundamental than picking the "best" model. We consider observations of the vertical gradient in CO2 from aircrafts and from a comparison of satellites that observe in the near infrared (which observe the column integrated CO2 field) and the thermal infrared (which observe the upper troposphere). We evaluate the feasibility of using these satellites for determining the vertical gradient in CO2. We examine how observations of the vertical gradient of CO2 allow us to differentiate the imprint of vertical mixing and the imprint in surface fluxes on the observed field of atmospheric CO2.

  2. Autotrophic and heterotrophic soil respiration determined with trenching, soil CO2 fluxes and 13CO2/12CO2 concentration gradients in a boreal forest ecosystem

    Science.gov (United States)

    Pumpanen, Jukka; Shurpali, Narasinha; Kulmala, Liisa; Kolari, Pasi; Heinonsalo, Jussi

    2017-04-01

    Soil CO2 efflux forms a substantial part of the ecosystem carbon balance, and it can contribute more than half of the annual ecosystem respiration. Recently assimilated carbon which has been fixed in photosynthesis during the previous days plays an important role in soil CO2 efflux, and its contribution is seasonally variable. Moreover, the recently assimilated C has been shown to stimulate the decomposition of recalcitrant C in soil and increase the mineralization of nitrogen, the most important macronutrient limiting gross primary productivity (GPP) in boreal ecosystems. Podzolic soils, typical in boreal zone, have distinctive layers with different biological and chemical properties. The biological activity in different soil layers has large seasonal variation due to vertical gradient in temperature, soil organic matter and root biomass. Thus, the source of CO2 and its components have a vertical gradient which is seasonally variable. The contribution of recently assimilated C and its seasonal as well as spatial variation in soil are difficult to assess without disturbing the system. The most common method of partitioning soil respiration into its components is trenching which entails the roots being cut or girdling where the flow of carbohydrates from the canopy to roots has been isolated by cutting of the phloem. Other methods for determining the contribution of autotrophic (Ra) and heterotrophic (Rh) respiration components in soil CO2 efflux are pulse labelling with 13CO2 or 14CO2 or the natural abundance of 13C and/or 14C isotopes. Also differences in seasonal and short-term temperature response of soil respiration have been used to separate Ra and Rh. We compared the seasonal variation in Ra and Rh using the trenching method and differences between seasonal and short-term temperature responses of soil respiration. I addition, we estimated the vertical variation in soil biological activity using soil CO2 concentration and the natural abundance of 13C and 12C

  3. Vertical gradients and seasonal variation in stem CO2 efflux within a Norway spruce stand.

    Science.gov (United States)

    Tarvainen, Lasse; Räntfors, Mats; Wallin, Göran

    2014-05-01

    Stem CO2 efflux is known to vary seasonally and vertically along tree stems. However, annual tree- and stand-scale efflux estimates are commonly based on measurements made only a few times a year, during daytime and at breast height. In this study, the effect of these simplifying assumptions on annual efflux estimates and their influence on the estimates of the importance of stems in stand-scale carbon cycling are evaluated. In order to assess the strength of seasonal, diurnal and along-stem variability in CO2 efflux, half-hourly measurements were carried out at three heights on three mature Norway spruce (Picea abies (L.) Karst.) trees over a period of 3 years. Making the common assumption of breast height efflux rates being representative of the entire stem was found to result in underestimations of 10-17% in the annual tree-scale CO2 efflux. Upscaling using only daytime measurements from breast height increased the underestimation to 15-20%. Furthermore, the results show that the strength of the vertical gradient varies seasonally, being strongest in the early summer and non-existent during the cool months. The observed seasonality in the vertical CO2 efflux gradient could not be explained by variation in stem temperature, temperature response of the CO2 efflux (Q10), outer-bark permeability, CO2 transport in the xylem or CO2 release from the phloem. However, the estimated CO2 concentration immediately beneath the bark was considerably higher in the upper stem during the main period of diameter growth, coinciding with the strongest vertical efflux gradient. These results suggest that higher growth rates in the upper stem are the main cause for the observed vertical variation in the stem CO2 effluxes. Furthermore, the results indicate that accounting for the vertical efflux variation is essential for assessments of the importance of stems in stand-scale carbon cycling.

  4. Mixed venous-arterial CO2 tension gradient after cardiopulmonary bypass.

    Science.gov (United States)

    Takami, Yoshiyuki; Masumoto, Hiroshi

    2005-09-01

    Significant venous hypercarbia has been reported in septic shock and circulatory failure. Cardiopulmonary bypass also impairs systemic and pulmonary blood perfusion. The objective of this study was to determine the clinical significance of the increased venous-arterial CO2 tension gradient resulting from venous hypercarbia after cardiopulmonary bypass. On arrival in the intensive care unit, venous and arterial CO2 tensions were measured in the radial and pulmonary arteries in 140 consecutive patients who had undergone coronary (n = 79), valve (n = 34), aortic (n = 20), and other (n = 7) surgery under cardiopulmonary bypass. The mean venous-arterial CO2 tension gradient was 5.0 +/- 3.3 mm Hg (range, 7.7 to 15.7 mm Hg). By linear regression analysis, the factors that significantly correlated with venous-arterial CO2 tension gradient were bypass duration, aortic crossclamp time, initial arterial lactate level, transpulmonary arteriovenous lactate difference, arterial bicarbonate level, base excess, cardiac index, mixed venous O2 saturation, O2 delivery, O2 consumption, and the peak value of creatine kinase. The venous-arterial CO2 tension gradient may reflect impaired perfusion and anaerobic metabolism induced by cardiopulmonary bypass and could be a simple and useful indicator for patient management after surgery under cardiopulmonary bypass.

  5. Aboveground net primary productivity and rainfall use efficiency of grassland on three soils after two years of exposure to a subambient to superambient CO2 gradient.

    Science.gov (United States)

    Fay, P. A.; Polley, H. W.; Jin, V. L.

    2008-12-01

    Atmospheric CO2 concentrations (CA) have increased by about 100 μL L-1 over the last 250 years to ~ 380 μL L-1, the highest values in the last half-million years, and CA is expected to continue to increase to greater than 500 μL L-1 by 2100. CO2 enrichment has been shown to affect many ecosystem processes, but experiments typically examine only two or a few levels of CA, and are typically constrained to one soil type. However, soil hydrologic properties differ across the landscape. Therefore, variation in the impacts of increasing CA on ecosystem function on different soil types must be understood to model and forecast ecosystem function under future CA and climate scenarios. Here we evaluate the aboveground net primary productivity (ANPP) of grassland plots receiving equal rainfall inputs (from irrigation) and exposed to a continuous gradient (250 to 500 μL L-1) of CA in the Lysimeter CO2 Gradient Experiment in central Texas, USA. Sixty intact soil monoliths (1 m2 x 1.5 m deep) taken from three soil types (Austin silty clay, Bastrop sandy loam, Houston clay) and planted to seven native tallgrass prairie grasses and forbs were exposed to the CA gradient beginning in 2006. Aboveground net primary productivity was assessed by end of season (November) harvest of each species in each monolith. Total ANPP of all species was 35 to 50% greater on Bastrop and Houston soils compared to Austin soils in both years (p Desmanthus illinoensis, and the forb Salvia azurea, and these showed no detectable response to CA. No species switched the sign of its response to CA among the soils. Thus, four of the seven species determined the ANPP and rainfall use efficiency responses to CA among the three soils. Interactions between soils and CA have important consequences for the productivity, rainfall use efficiency, and species composition of grassland under future atmospheric CO2 concentrations.

  6. Decline in coccolithophore diversity and impact on coccolith morphogenesis along a natural CO2 gradient.

    Science.gov (United States)

    Ziveri, Patrizia; Passaro, Marcello; Incarbona, Alessandro; Milazzo, Marco; Rodolfo-Metalpa, Riccardo; Hall-Spencer, Jason M

    2014-06-01

    A natural pH gradient caused by marine CO2 seeps off Vulcano Island (Italy) was used to assess the effects of ocean acidification on coccolithophores, which are abundant planktonic unicellular calcifiers. Such seeps are used as natural laboratories to study the effects of ocean acidification on marine ecosystems, since they cause long-term changes in seawater carbonate chemistry and pH, exposing the organisms to elevated CO2 concentrations and therefore mimicking future scenarios. Previous work at CO2 seeps has focused exclusively on benthic organisms. Here we show progressive depletion of 27 coccolithophore species, in terms of cell concentrations and diversity, along a calcite saturation gradient from Ωcalcite 6.4 to CO2 seeps had the highest concentrations of malformed Emiliania huxleyi. These observations add to a growing body of evidence that ocean acidification may benefit some algae but will likely cause marine biodiversity loss, especially by impacting calcifying species, which are affected as carbonate saturation falls.

  7. Atmospheric CO2 and soil extracellular enzyme activity: A meta-analysis and CO2 gradient experiment

    Science.gov (United States)

    Rising atmospheric CO2 concentrations may alter carbon and nutrient cycling and microbial processes in terrestrial ecosystems. One of the primary ways that microbes interact with soil organic matter is through the production of extracellular enzymes, which break down large, complex organic molecules...

  8. Study on Purifying Technology of Andrographolide by Supercritical CO2 Secondary Gradient Crystallization

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen-cheng; PAN Jian

    2004-01-01

    The effects of the secondary gradient crystallizing pressure, temperature and time on the purity and crystallization ratio of andrographolide were investigated via single factor experiments. The shape of crystal was observed with scanning electron microscopy (SEM). The purity of andrographolide was determined by high pressure liquid chromatography (HPLC). It was found that the optimized parameters were pressure 14 MPa, temperature 55℃,time 60 min, and CO2 flow rate 15 L min-1, under these conditions the particle of andrographolide was much smaller, the crystal of andrographolide was distributed in floccule on crystal board, with the purity of andrographolide 92.5%, the crystallization ratio 48.9%.

  9. Quantifying CO2 Fluxes Across a Gradient of Permafrost in Boreal Alaska

    Science.gov (United States)

    Euskirchen, E. S.; Edgar, C.; Turetsky, M. R.; Harden, J. W.; McGuire, A. D.

    2011-12-01

    Changes in vegetation and soil properties following permafrost degradation and thermokarst development may cause changes in net carbon uptake, either by stimulating primary productivity due to changes in vegetation composition or by stimulating soil microbial decomposition. In order to better understand these dynamics, we established three sites in interior Alaska across a gradient of permafrost in which permafrost varies in presence and stability. These sites include a black spruce ecosystem with cold soils and stable permafrost, a permafrost collapse scar with thermokarst formation, and a moderately rich fen lacking near surface permafrost. Measurements at the sites include year-round eddy covariance estimates of CO2, water, and energy fluxes as well as the associated micrometeorological variables. During winter, the ecosystems each released approximately 15 - 25 g C m-2 mo-1. However, the black spruce ecosystem began to take up CO2 as soon as air temperatures increased in the spring, with an estimated accumulation of ~23 g C m-2 from late March to early May. During this same period, we observed unusually high rates of ecosystem respiration some days at the thermokarst site, potentially due to the release of trapped CO2 from frozen soil gas pockets. While the black spruce ecosystem continued to act as a net sink of CO2 in the summer, taking up ~2.5± 1 g C m-2 d-1, the thermokarst and fen ecosystems remained CO2 sources, respectively releasing ~2.4 ± 0.8 g C m-2 d-1 and ~1.9 ± 1.1 g C m-2 d-1. While ecosystem respiration was similar across all three ecosystems during the summer (~4.8 ± 1.0 g C m-2 d-1), gross primary productivity was much higher in the spruce ecosystem (~7.3 ± 1.4 g C m-2 d-1) compared to the thermokarst (~ 2.5 ± 0.9 g C m-2 d-1) and fen ecosystems (~ 3.0 ± 1.1 g C m-2 d-1). These results suggest that in these boreal peatland ecosystems, permafrost thaw and thermokarst development will increase CO2 emissions to the atmosphere due to

  10. The doubled CO2 climate - Impact of the sea surface temperature gradient

    Science.gov (United States)

    Rind, David

    1987-01-01

    The Goddard Institute for Space Studies (GISS) GCM of Hansen et al. (1983) was run, with 4 deg x 5 deg resolution, with doubled CO2 and two sets of sea surface temperature gradient distributions. One set was derived from the equilibrium doubled CO2 run of the 8 deg x 10 deg GISS GCM, with minimal high latitude amplification. The other set resembled closely the GFDL model results, with greater amplification. Both experiments had the same global mean surface air temperature change. The two experiments were often found to produce substantially different climate characteristics. With reduced high latitude amplification (set one), and thus, more equatorial warming, there was a greater increase in specific humidity and the greenhouse capacity of the atmosphere, resulting in a warmer atmosphere in general. Features such as the low-latitude precipitation, Hadley cell intensity, jet stream magnitude, and atmospheric energy transports all increased in comparison with the control run. In contrast, these features all decreased in the experiment with greater high latitude amplification (set two).

  11. Altered brain ion gradients following compensation for elevated CO2 are linked to behavioural alterations in a coral reef fish

    Science.gov (United States)

    Heuer, R. M.; Welch, M. J.; Rummer, J. L.; Munday, P. L.; Grosell, M.

    2016-01-01

    Neurosensory and behavioural disruptions are some of the most consistently reported responses upon exposure to ocean acidification-relevant CO2 levels, especially in coral reef fishes. The underlying cause of these disruptions is thought to be altered current across the GABAA receptor in neuronal cells due to changes in ion gradients (HCO3− and/or Cl−) that occur in the body following compensation for elevated ambient CO2. Despite these widely-documented behavioural disruptions, the present study is the first to pair a behavioural assay with measurements of relevant intracellular and extracellular acid-base parameters in a coral reef fish exposed to elevated CO2. Spiny damselfish (Acanthochromis polyacanthus) exposed to 1900 μatm CO2 for 4 days exhibited significantly increased intracellular and extracellular HCO3− concentrations and elevated brain pHi compared to control fish, providing evidence of CO2 compensation. As expected, high CO2 exposed damselfish spent significantly more time in a chemical alarm cue (CAC) than control fish, supporting a potential link between behavioural disruption and CO2 compensation. Using HCO3− measurements from the damselfish, the reversal potential for GABAA (EGABA) was calculated, illustrating that biophysical properties of the brain during CO2 compensation could change GABAA receptor function and account for the behavioural disturbances noted during exposure to elevated CO2. PMID:27620837

  12. Altered brain ion gradients following compensation for elevated CO2 are linked to behavioural alterations in a coral reef fish.

    Science.gov (United States)

    Heuer, R M; Welch, M J; Rummer, J L; Munday, P L; Grosell, M

    2016-09-13

    Neurosensory and behavioural disruptions are some of the most consistently reported responses upon exposure to ocean acidification-relevant CO2 levels, especially in coral reef fishes. The underlying cause of these disruptions is thought to be altered current across the GABAA receptor in neuronal cells due to changes in ion gradients (HCO3(-) and/or Cl(-)) that occur in the body following compensation for elevated ambient CO2. Despite these widely-documented behavioural disruptions, the present study is the first to pair a behavioural assay with measurements of relevant intracellular and extracellular acid-base parameters in a coral reef fish exposed to elevated CO2. Spiny damselfish (Acanthochromis polyacanthus) exposed to 1900 μatm CO2 for 4 days exhibited significantly increased intracellular and extracellular HCO3(-) concentrations and elevated brain pHi compared to control fish, providing evidence of CO2 compensation. As expected, high CO2 exposed damselfish spent significantly more time in a chemical alarm cue (CAC) than control fish, supporting a potential link between behavioural disruption and CO2 compensation. Using HCO3(-) measurements from the damselfish, the reversal potential for GABAA (EGABA) was calculated, illustrating that biophysical properties of the brain during CO2 compensation could change GABAA receptor function and account for the behavioural disturbances noted during exposure to elevated CO2.

  13. End-tidal arterial CO2 partial pressure gradient in patients with severe hypercapnia undergoing noninvasive ventilation

    Directory of Open Access Journals (Sweden)

    Defilippis V

    2013-06-01

    Full Text Available Vito Defilippis,1 Davide D’Antini,2 Gilda Cinnella,2 Michele Dambrosio,2 Fernando Schiraldi,3 Vito Procacci1 1Emergency Department, Riuniti Hospital, 2Department of Anaesthesiology and Intensive Care, University of Foggia, Foggia, 3Emergency Department, San Paolo Hospital, Naples, Italy Background: Patients with severe hypercapnia represent a particularly serious condition in an emergency department (ED, requiring immediate attention. Noninvasive ventilation (NIV is an integral part of the treatment for acute respiratory failure. The present study aimed to validate the measurement of end-tidal CO2 (EtCO2 as a noninvasive technique to evaluate the effectiveness of NIV in acute hypercapnic respiratory failure. Methods: Twenty consecutive patients admitted to the ED with severe dyspnea were enrolled in the study. NIV by means of bilevel positive airway pressure, was applied to the patients simultaneously with standard medical therapy and continued for 12 hours; the arterial blood gases and side-stream nasal/oral EtCO2 were measured at subsequent times: T0 (admission to the ED, T1h (after 1 hour, T6h (after 6 hours, and T12h (after 12 hours during NIV treatment. Results: The arterial CO2 partial pressure (PaCO2–EtCO2 gradient decreased progressively, reaching at T6h and T12h values lower than baseline (P < 0.001, while arterial pH increased during the observation period (P < 0.001. A positive correlation was found between EtCO2 and PaCO2 values (r = 0.89, P < 0.001 at the end of the observation period. Conclusion: In our hypercapnic patients, the effectiveness of the NIV was evidenced by the progressive reduction of the PaCO2–EtCO2 gradient. The measurement of the CO2 gradient could be a reliable method in monitoring the effectiveness of NIV in acute hypercapnic respiratory failure in the ED. Keywords: arterial end-tidal CO2 gradient, noninvasive ventilation, bilevel positive airway pressure, acute respiratory failure

  14. Host Plant Physiology and Mycorrhizal Functioning Shift across a Glacial through Future [CO2] Gradient1[OPEN

    Science.gov (United States)

    Mullinix, George W.R.; Ward, Joy K.

    2016-01-01

    Rising atmospheric carbon dioxide concentration ([CO2]) may modulate the functioning of mycorrhizal associations by altering the relative degree of nutrient and carbohydrate limitations in plants. To test this, we grew Taraxacum ceratophorum and Taraxacum officinale (native and exotic dandelions) with and without mycorrhizal fungi across a broad [CO2] gradient (180–1,000 µL L−1). Differential plant growth rates and vegetative plasticity were hypothesized to drive species-specific responses to [CO2] and arbuscular mycorrhizal fungi. To evaluate [CO2] effects on mycorrhizal functioning, we calculated response ratios based on the relative biomass of mycorrhizal (MBio) and nonmycorrhizal (NMBio) plants (RBio = [MBio − NMBio]/NMBio). We then assessed linkages between RBio and host physiology, fungal growth, and biomass allocation using structural equation modeling. For T. officinale, RBio increased with rising [CO2], shifting from negative to positive values at 700 µL L−1. [CO2] and mycorrhizal effects on photosynthesis and leaf growth rates drove shifts in RBio in this species. For T. ceratophorum, RBio increased from 180 to 390 µL L−1 and further increases in [CO2] caused RBio to shift from positive to negative values. [CO2] and fungal effects on plant growth and carbon sink strength were correlated with shifts in RBio in this species. Overall, we show that rising [CO2] significantly altered the functioning of mycorrhizal associations. These symbioses became more beneficial with rising [CO2], but nonlinear effects may limit plant responses to mycorrhizal fungi under future [CO2]. The magnitude and mechanisms driving mycorrhizal-CO2 responses reflected species-specific differences in growth rate and vegetative plasticity, indicating that these traits may provide a framework for predicting mycorrhizal responses to global change. PMID:27573369

  15. Long-term lysimeter experiment to analyze the influence of the climate change on matter fluxes

    Science.gov (United States)

    Pütz, Thomas; Groh, Jannis; Wollschläger, Ute; Gerke, Horst; Priesack, Eckart; Kiese, Ralf; Borg, Erik; Vereecken, Harry

    2015-04-01

    Based on the TERENO SoilCan infrastructure, a long-term large-scale experiment was designed to study the effects of climate change on terrestrial systems. The water and matter fluxes in soil are the main focuses of SoilCan. In the frame of SoilCan, fully automated lysimeter systems were installed on several highly equipped experimental field sites of the TERENO-observatories and the relevant status variables of each ecosystem were monitored (e.g. climate, hydrology, biosphere-atmosphere exchange, biodiversity, etc.). In total, 90 lysimeters (1.5 m depth, 1m2 surface) were filled with soil monoliths at the four TERENO-observatories and were instrumented with TDRs, tensiometers, temperature sensors, soil heat flux plates, and CO2 sensors. For the controlling of the lower boundary condition, suction candle rakes were installed into the lysimeter bottoms. In combination with bi-directional pumps and tanks, the water content of the lysimeters was adjusted to the surrounded original field sites. To simulate the expected climate change, 48 lysimeters were transferred along temperature and rainfall gradients within the respective observatories and between the observatories, based on the principle 'Space for Time'. In case of the "Rur" observatory, three intensively instrumented field sites ("Wüstebach", "Rollesbroich" und "Selhausen") were equipped with lysimeter stations. These three field sites include different land uses, "Wüstebach" as a forest site, "Rollesbroich" as a grassland and "Selhausen" as an arable site. In order to standardize the agronomic management, the crop rotation at the arable lysimeters comprised winter wheat - winter rye - winter barley - oats. For investigation of the matter flux, soil solutions and leachates were regularly sampled. The water balances and the dynamics of the carbon and nitrogen fluxes in the first two years of the experiment will be presented.

  16. Dominant plant taxa predict plant productivity responses to CO2 enrichment across precipitation and soil gradients

    Science.gov (United States)

    Fay, Philip A.; Newingham, Beth A.; Polley, H. Wayne; Morgan, Jack A.; LeCain, Daniel R.; Nowak, Robert S.; Smith, Stanley D.

    2015-01-01

    The Earth's atmosphere will continue to be enriched with carbon dioxide (CO2) over the coming century. Carbon dioxide enrichment often reduces leaf transpiration, which in water-limited ecosystems may increase soil water content, change species abundances and increase the productivity of plant communities. The effect of increased soil water on community productivity and community change may be greater in ecosystems with lower precipitation, or on coarser-textured soils, but responses are likely absent in deserts. We tested correlations among yearly increases in soil water content, community change and community plant productivity responses to CO2 enrichment in experiments in a mesic grassland with fine- to coarse-textured soils, a semi-arid grassland and a xeric shrubland. We found no correlation between CO2-caused changes in soil water content and changes in biomass of dominant plant taxa or total community aboveground biomass in either grassland type or on any soil in the mesic grassland (P > 0.60). Instead, increases in dominant taxa biomass explained up to 85 % of the increases in total community biomass under CO2 enrichment. The effect of community change on community productivity was stronger in the semi-arid grassland than in the mesic grassland, where community biomass change on one soil was not correlated with the change in either the soil water content or the dominant taxa. No sustained increases in soil water content or community productivity and no change in dominant plant taxa occurred in the xeric shrubland. Thus, community change was a crucial driver of community productivity responses to CO2 enrichment in the grasslands, but effects of soil water change on productivity were not evident in yearly responses to CO2 enrichment. Future research is necessary to isolate and clarify the mechanisms controlling the temporal and spatial variations in the linkages among soil water, community change and plant productivity responses to CO2 enrichment. PMID

  17. Characterization of an urban-rural CO 2 /temperature gradient and associated changes in initial plant productivity during secondary succession

    Energy Technology Data Exchange (ETDEWEB)

    Ziska, L. H.; Bunce, J. A.; Goins, E. W.

    2004-05-01

    To examine the impact of climate change on vegetative productivity, we exposed fallow agricultural soil to an in situ temperature and CO2 gradient between urban, suburban and rural areas in 2002. Along the gradient, average daytime CO2 concentration increased by 21% and maximum (daytime) and minimum (nighttime) daily temperatures increased by 1.6 and 3.3°C, respectively in an urban relative to a rural location. Consistent location differences in soil temperature were also ascertained. No other consistent differences in meteorological variables (e.g. wind speed, humidity, PAR, tropospheric ozone) as a function of urbanization were documented. The urban-induced environmental changes that were observed were consistent with most short-term (~50 year) global change scenarios regarding CO2 concentration and air temperature. Productivity, determined as final above-ground biomass, and maximum plant height were positively affected by daytime and soil temperatures as well as enhanced [CO2], increasing 60 and 115% for the suburban and urban sites, respectively, relative to the rural site. While long-term data are needed, these initial results suggest that urban environments may act as a reasonable surrogate for investigating future climatic change in vegetative communities.

  18. Mechanisms influencing surface soil CO2 efflux in respect to elevation and vegetation gradients in a complex watershed

    Science.gov (United States)

    Atkins, J. W.; Epstein, H. E.; Welsch, D. L.

    2011-12-01

    Topographically complex watersheds exert spatial and temporal variations in the distribution of soil water due to horizontal flows. The redistribution of soil water has profound effects on biogeochemical cycles. Of keen interest is the impact this lateral redistribution has on carbon cycling and surface soil carbon efflux. We are currently employing a plot based study across an elevation gradient (950-1150 m) in the Weimer Run watershed located near Davis, West Virginia to evaluate carbon and water cycling dynamics. At each of three different elevation levels (high, middle, low) are three sites. At each site are three 4 m2 plots, each underneath a different vegetation cover type (open, closed tree canopy, shrub canopy), for a total of 27 plots across all elevations. At each plot, surface CO2 efflux, soil temperature, PAR, air temperature and volumetric soil water content at 0-12 cm are measured weekly during the growing season. Measurements of Leaf Area Index (LAI) and soil nutrient concentrations (NH4+, NO3-) have also been conducted for each plot. Each plot also has gas wells at both 5 and 20 cm to measure CO2 concentrations below the soil surface. Data collected from June through October, 2010, indicate a stronger control on soil CO2 efflux exerted by vegetation cover type than by elevation gradient. The impact of vegetation cover type on soil CO2 efflux increases with elevation. Based on data collected weekly from June through October, 2010, there is no significant relationship between surface soil CO2 efflux and the three elevation levels within our gradient (p = 0.47). However, a significant statistical relationship between surface soil CO2 efflux and vegetation type (p = impact that vegetation cover, elevation and micrometeorological controls exert on soil CO2 efflux is vital for accurate model inputs and carbon budgets.class="jpg" border=0 width=600px src="/meetings/fm11/program/tables/B33F-0525_T1.jpg"> * All values in columns represent means for

  19. Proton acceleration using doped Argon plasma density gradient interacting with relativistic CO2 -laser pulse

    Science.gov (United States)

    Sahai, Aakash; Ettlinger, Oliver; Hicks, George; Ditter, Emma-Jane; Najmudin, Zulfikar

    2016-10-01

    We investigate proton and light-ion acceleration driven by the interaction of relativistic CO2 laser pulses with overdense Argon or other heavy-ion gas targets doped with lighter-ion species. Optically shaping the gas targets allows tuning of the pre-plasma scale-length from a few to several laser wavelengths, allowing the laser to efficiently drive a propagating snowplow through the bunching in the electron density. Preliminary PIC-based modeling shows that the lighter-ion species is accelerated even without any significant motion of the heavier ions which is a signature of the Relativistically Induced Transparency Acceleration mechanism. Some outlines of possible experiments at the TW CO2 laser at the Accelerator Test Facility at Brookhaven National Laboratory are presented.

  20. On the calculation of air-sea fluxes of CO2 in the presence of temperature and salinity gradients

    Science.gov (United States)

    Woolf, D. K.; Land, P. E.; Shutler, J. D.; Goddijn-Murphy, L. M.; Donlon, C. J.

    2016-02-01

    The presence of vertical temperature and salinity gradients in the upper ocean and the occurrence of variations in temperature and salinity on time scales from hours to many years complicate the calculation of the flux of carbon dioxide (CO2) across the sea surface. Temperature and salinity affect the interfacial concentration of aqueous CO2 primarily through their effect on solubility with lesser effects related to saturated vapor pressure and the relationship between fugacity and partial pressure. The effects of temperature and salinity profiles in the water column and changes in the aqueous concentration act primarily through the partitioning of the carbonate system. Climatological calculations of flux require attention to variability in the upper ocean and to the limited validity of assuming "constant chemistry" in transforming measurements to climatological values. Contrary to some recent analysis, it is shown that the effect on CO2 fluxes of a cool skin on the sea surface is large and ubiquitous. An opposing effect on calculated fluxes is related to the occurrence of warm layers near the surface; this effect can be locally large but will usually coincide with periods of low exchange. A salty skin and salinity anomalies in the upper ocean also affect CO2 flux calculations, though these haline effects are generally weaker than the thermal effects.

  1. Evidence of a universal scaling relationship for leaf CO2 drawdown along an aridity gradient.

    Science.gov (United States)

    Prentice, I Colin; Meng, Tingting; Wang, Han; Harrison, Sandy P; Ni, Jian; Wang, Guohong

    2011-04-01

    The leaf carbon isotope ratio (δ(13) C) of C3 plants is inversely related to the drawdown of CO2 concentration during photosynthesis, which increases towards drier environments. We aimed to discriminate between the hypothesis of universal scaling, which predicts between-species responses of δ(13) C to aridity similar to within-species responses, and biotic homoeostasis, which predicts offsets in the δ(13) C of species occupying adjacent ranges. The Northeast China Transect spans 130-900 mm annual precipitation within a narrow latitude and temperature range. Leaves of 171 species were sampled at 33 sites along the transect (18 at ≥ 5 sites) for dry matter, carbon (C) and nitrogen (N) content, specific leaf area (SLA) and δ(13) C. The δ(13) C of species generally followed a common relationship with the climatic moisture index (MI). Offsets between adjacent species were not observed. Trees and forbs diverged slightly at high MI. In C3 plants, δ(13) C predicted N per unit leaf area (Narea) better than MI. The δ(13) C of C4 plants was invariant with MI. SLA declined and Narea increased towards low MI in both C3 and C4 plants. The data are consistent with optimal stomatal regulation with respect to atmospheric dryness. They provide evidence for universal scaling of CO2 drawdown with aridity in C3 plants.

  2. High CO2 fluxes from grassland on histic Gleysol along soil carbon and drainage gradients

    Science.gov (United States)

    Leiber-Sauheitl, K.; Fuß, R.; Voigt, C.; Freibauer, A.

    2014-02-01

    Drained organic soils are anthropogenic emission hotspots of greenhouse gases (GHGs). Most studies have focused on deep peat soils and on peats with high organic carbon content. In contrast, histic Gleysols are characterized by shallow peat layers, which are left over from peat cutting activities or by peat mixed with mineral soil. It is unknown whether they emit less GHGs than deep Histosols when drained. We present the annual carbon and GHG balance of grasslands for six sites on nutrient-poor histic Gleysols with a shallow (30 cm) histic horizon or mixed with mineral soil in Northern Germany (soil organic carbon concentration (Corg) from 9 to 52%). The net GHG balance, corrected for carbon export by harvest, was around 4 t CO2-C-eq ha-1 yr-1 on soils with peat layer and little drainage (mean annual water table GHG inventories which are likely not to include histic Gleysols. The land area with GHG emission hotspots due to drainage is likely to be much higher than anticipated. Deeply drained histic Gleysols are GHG hotspots that have so far been neglected or underestimated. Peat mixing with sand does not mitigate GHG emissions. Our study implies that rewetting organic soils, including histic Gleysols, has a much higher relevance for GHG mitigation strategies than currently recognized.

  3. Spatial and temporal variation of CO2 efflux along a disturbance gradient in a miombo woodland in Western Zambia

    Directory of Open Access Journals (Sweden)

    M. M. Mukelabai

    2011-01-01

    Full Text Available Carbon dioxide efflux from the soil surface was measured over a period of several weeks within a heterogeneous Brachystegia spp. dominated miombo woodland in Western Zambia. The objectives were to examine spatial and temporal variation of soil respiration along a disturbance gradient from a protected forest reserve to a cut, burned, and grazed area outside, and to relate the flux to various abiotic and biotic drivers. The highest daily mean fluxes (around 12 μmol CO2 m−2 s−1 were measured in the protected forest in the wet season and lowest daily mean fluxes (around 1 μmol CO2 m−2 s−1 in the most disturbed area during the dry season. Diurnal variation of soil respiration was closely correlated with soil temperature. The combination of soil water content and soil temperature was found to be the main driving factor at seasonal time scale. There was a 75% decrease in soil CO2 efflux during the dry season and a 20% difference in peak soil respiratory flux measured in 2008 and 2009. Spatial variation of CO2 efflux was positively related to total soil carbon content in the undisturbed area but not at the disturbed site. Coefficients of variation of efflux rates between plots decreased towards the core zone of the protected forest reserve. Normalized soil respiration values did not vary significantly along the disturbance gradient. Spatial variation of respiration did not show a clear distinction between the disturbed and undisturbed sites and could not be explained by variables such as leaf area index. In contrast, within plot variability of soil respiration was explained by soil organic carbon content. Three different approaches to calculate total ecosystem respiration (Reco from eddy covariance measurements were compared to two bottom-up estimates of Reco obtained from chambers measurements of soil- and leaf respiration which differed in the consideration of spatial heterogeneity. The consideration of spatial variability resulted only in

  4. Seaweed fails to prevent ocean acidification impact on foraminifera along a shallow-water CO2 gradient.

    Science.gov (United States)

    Pettit, Laura R; Smart, Christopher W; Hart, Malcolm B; Milazzo, Marco; Hall-Spencer, Jason M

    2015-05-01

    Ocean acidification causes biodiversity loss, alters ecosystems, and may impact food security, as shells of small organisms dissolve easily in corrosive waters. There is a suggestion that photosynthetic organisms could mitigate ocean acidification on a local scale, through seagrass protection or seaweed cultivation, as net ecosystem organic production raises the saturation state of calcium carbonate making seawater less corrosive. Here, we used a natural gradient in calcium carbonate saturation, caused by shallow-water CO2 seeps in the Mediterranean Sea, to assess whether seaweed that is resistant to acidification (Padina pavonica) could prevent adverse effects of acidification on epiphytic foraminifera. We found a reduction in the number of species of foraminifera as calcium carbonate saturation state fell and that the assemblage shifted from one dominated by calcareous species at reference sites (pH ∼8.19) to one dominated by agglutinated foraminifera at elevated levels of CO2 (pH ∼7.71). It is expected that ocean acidification will result in changes in foraminiferal assemblage composition and agglutinated forms may become more prevalent. Although Padina did not prevent adverse effects of ocean acidification, high biomass stands of seagrass or seaweed farms might be more successful in protecting epiphytic foraminifera.

  5. Surface CO2 Exchange Dynamics across a Climatic Gradient in McKenzie Valley: Effect of Landforms, Climate and Permafrost

    Directory of Open Access Journals (Sweden)

    Natalia Startsev

    2016-11-01

    Full Text Available Northern regions are experiencing considerable climate change affecting the state of permafrost, peat accumulation rates, and the large pool of carbon (C stored in soil, thereby emphasizing the importance of monitoring surface C fluxes in different landform sites along a climate gradient. We studied surface net C exchange (NCE and ecosystem respiration (ER across different landforms (upland, peat plateau, collapse scar in mid-boreal to high subarctic ecoregions in the Mackenzie Valley of northwestern Canada for three years. NCE and ER were measured using automatic CO2 chambers (ADC, Bioscientific LTD., Herts, England, and soil respiration (SR was measured with solid state infrared CO2 sensors (Carbocaps, Vaisala, Vantaa, Finland using the concentration gradient technique. Both NCE and ER were primarily controlled by soil temperature in the upper horizons. In upland forest locations, ER varied from 583 to 214 g C·m−2·year−1 from mid-boreal to high subarctic zones, respectively. For the bog and peat plateau areas, ER was less than half that at the upland locations. Of SR, nearly 75% was generated in the upper 5 cm layer composed of live bryophytes and actively decomposing fibric material. Our results suggest that for the upland and bog locations, ER significantly exceeded NCE. Bryophyte NCE was greatest in continuously waterlogged collapsed areas and was negligible in other locations. Overall, upland forest sites were sources of CO2 (from 64 g·C·m−2·year−1 in the high subarctic to 588 g C·m−2·year−1 in mid-boreal zone; collapsed areas were sinks of C, especially in high subarctic (from 27 g·C·m−2 year−1 in mid-boreal to 86 g·C·m−2·year−1 in high subarctic and peat plateaus were minor sources (from 153 g·C·m−2·year−1 in mid-boreal to 6 g·C·m−2·year−1 in high subarctic. The results are important in understanding how different landforms are responding to climate change and would be useful in modeling the

  6. Elevated CO2 and O3 effects on ectomycorrhizal fungal root tip communities in consideration of a post-agricultural soil nutrient gradient legacy.

    Science.gov (United States)

    Andrew, Carrie; Lilleskov, Erik A

    2014-11-01

    Despite the critical role of EMF in nutrient and carbon (C) dynamics, combined effects of global atmospheric pollutants on ectomycorrhizal fungi (EMF) are unclear. Here, we present research on EMF root-level community responses to elevated CO2 and O3. We discovered that belowground EMF community richness and similarity were both negatively affected by CO2 and O3, but the effects of CO2 and O3 on EMF communities were contingent on a site soil pH and cation availability gradient. These results contrast with our previous work showing a strong direct effect of CO2 and O3 on sporocarp community dynamics and production. We discuss the possible role of carbon demand and allocation by EMF taxa in the discrepancy of these results. EMF communities were structured by a legacy of spatially defined soil properties, changing atmospheric chemistry and temporal dynamics. It is therefore necessary to understand global change impacts across multiple environmental gradients and spatiotemporal scales.

  7. Spatial and temporal variation of CO2 efflux along a disturbance gradient in a miombo woodland in Western Zambia

    Directory of Open Access Journals (Sweden)

    W. L. Kutsch

    2010-07-01

    Full Text Available Carbon dioxide efflux from the soil surface was measured over a period of several weeks within a heterogeneous Brachystegia spp. dominated miombo woodland in Western Zambia. The objectives were to examine spatial and temporal variation of soil respiration along a disturbance gradient from a protected forest reserve to a cut, burned, and grazed area outside, and to relate the flux to various abiotic and biotic drivers. The highest daily mean fluxes (around 12 μmol m−2 s−1 were measured in the protected forest in the wet season and lowest daily mean fluxes (around 1 μmol m−2 s−1 in the most disturbed area during the dry season. Diurnal variation of soil respiration was closely correlated with soil temperature. The combination of soil water content and soil temperature was found to be the main driving factor at seasonal time scale. There was a 75% decrease in soil CO2 efflux during the dry season and a 20% difference in peak soil respiratory flux measured in 2008 and 2009. Spatial variation of CO2 efflux was positively related to total soil carbon content in the undisturbed area but not at the disturbed site. Coefficients of variation of efflux rates between plots decreased towards the core zone of the protected forest reserve. Normalized soil respiration values did not vary significantly along the disturbance gradient. Spatial variation of respiration did not show a clear distinction between the disturbed and undisturbed sites and was neither explained by soil carbon nor leaf area index. In contrast, within plot variability of soil respiration was explained by soil organic carbon content. Three different approaches to calculate total ecosystem respiration (Reco from eddy covariance measurements were compared to two bottom-up estimates of Reco obtained from chambers measurements of soil- and leaf respiration which differed in the consideration of spatial heterogeneity. The consideration of spatial variability resulted only in small

  8. Sensitivity to ocean acidification parallels natural pCO2 gradients experienced by Arctic copepods under winter sea ice.

    Science.gov (United States)

    Lewis, Ceri N; Brown, Kristina A; Edwards, Laura A; Cooper, Glenn; Findlay, Helen S

    2013-12-17

    The Arctic Ocean already experiences areas of low pH and high CO2, and it is expected to be most rapidly affected by future ocean acidification (OA). Copepods comprise the dominant Arctic zooplankton; hence, their responses to OA have important implications for Arctic ecosystems, yet there is little data on their current under-ice winter ecology on which to base future monitoring or make predictions about climate-induced change. Here, we report results from Arctic under-ice investigations of copepod natural distributions associated with late-winter carbonate chemistry environmental data and their response to manipulated pCO2 conditions (OA exposures). Our data reveal that species and life stage sensitivities to manipulated OA conditions were correlated with their vertical migration behavior and with their natural exposures to different pCO2 ranges. Vertically migrating adult Calanus spp. crossed a pCO2 range of >140 μatm daily and showed only minor responses to manipulated high CO2. Oithona similis, which remained in the surface waters and experienced a pCO2 range of <75 μatm, showed significantly reduced adult and nauplii survival in high CO2 experiments. These results support the relatively untested hypothesis that the natural range of pCO2 experienced by an organism determines its sensitivity to future OA and highlight that the globally important copepod species, Oithona spp., may be more sensitive to future high pCO2 conditions compared with the more widely studied larger copepods.

  9. Measuring the human ventilatory and cerebral blood flow response to CO2: a technical consideration for the end-tidal-to-arterial gas gradient.

    Science.gov (United States)

    Tymko, Michael M; Hoiland, Ryan L; Kuca, Tomas; Boulet, Lindsey M; Tremblay, Joshua C; Pinske, Bryenna K; Williams, Alexandra M; Foster, Glen E

    2016-01-15

    Our aim was to quantify the end-tidal-to-arterial gas gradients for O2 (PET-PaO2) and CO2 (Pa-PETCO2) during a CO2 reactivity test to determine their influence on the cerebrovascular (CVR) and ventilatory (HCVR) response in subjects with (PFO+, n = 8) and without (PFO-, n = 7) a patent foramen ovale (PFO). We hypothesized that 1) the Pa-PETCO2 would be greater in hypoxia compared with normoxia, 2) the Pa-PETCO2 would be similar, whereas the PET-PaO2 gradient would be greater in those with a PFO, 3) the HCVR and CVR would be underestimated when plotted against PETCO2 compared with PaCO2, and 4) previously derived prediction algorithms will accurately target PaCO2. PETCO2 was controlled by dynamic end-tidal forcing in steady-state steps of -8, -4, 0, +4, and +8 mmHg from baseline in normoxia and hypoxia. Minute ventilation (V̇E), internal carotid artery blood flow (Q̇ICA), middle cerebral artery blood velocity (MCAv), and temperature corrected end-tidal and arterial blood gases were measured throughout experimentation. HCVR and CVR were calculated using linear regression analysis by indexing V̇E and relative changes in Q̇ICA, and MCAv against PETCO2, predicted PaCO2, and measured PaCO2. The Pa-PETCO2 was similar between hypoxia and normoxia and PFO+ and PFO-. The PET-PaO2 was greater in PFO+ by 2.1 mmHg during normoxia (P = 0.003). HCVR and CVR plotted against PETCO2 underestimated HCVR and CVR indexed against PaCO2 in normoxia and hypoxia. Our PaCO2 prediction equation modestly improved estimates of HCVR and CVR. In summary, care must be taken when indexing reactivity measures to PETCO2 compared with PaCO2. Copyright © 2016 the American Physiological Society.

  10. Construction and evaluation of simulated pilot scale landfill lysimeter in Bangladesh.

    Science.gov (United States)

    Rafizul, Islam M; Howlader, Milon Kanti; Alamgir, Muhammed

    2012-11-01

    This research concentrates the design, construction and evaluation of simulated pilot scale landfill lysimeter at KUET campus, Khulna, Bangladesh. Both the aerobic and anaerobic conditions having a base liner and two different types of cap liner were simulated. After the design of a reference cell, the construction of landfill lysimeter was started in January 2008 and completed in July 2008. In all construction process locally available civil construction materials were used. The municipal solid waste (MSW) of 2800-2985 kg having the total volume of 2.80 m(3) (height 1.6 m) and moisture content of 65% was deposited in each lysimeter by applying required compaction energy. In contrast, both the composition in terms of methane (CH(4)), carbon dioxide (CO(2)) and oxygen (O(2)) as well as the flow rate of landfill gas (LFG) generated from MSW in landfill lysimeter were measured and varied significantly in relation to the variation of lysimeter operational condition. Moreover, anaerobic lysimeter-C shows the highest composition of LFG in compare to the anaerobic lysimeter-B due to the providing of lower compaction of cap liner in anaerobic lysimeter-C. Here, it is interesting to note that in absence of compacted clay liner (CCL) and hence percolation of rainwater that facilitates rapid degradation of MSW in aerobic lysimeter-A has resulted in the highest settlement than that of anaerobic landfill lysimeter-B and C. Moreover, in case of anaerobic lysimeter-B and C, the leachate generation was lower than that of aerobic lysimeter-A due to the providing of cap liner in anaerobic lysimeter-B and C, played an important role to reduce the percolation of rainwater. The study also reveals that the leachate pollution index (LPI) has decreased in relation to the increasing of elapsed period as well as the LPI for collection system of aerobic lysimeter-A was higher than that of the collection system of anaerobic lysimeter-B and C. Finally, it can be depicted that LPI for lysimeter

  11. Avaliação inicial dos gradientes sistêmicos e regionais da pCO2 como marcadores de hipoperfusão mesentérica Initial evaluation of systemic and regional pCO2 gradients as markers of mesenteric hypoperfusion

    Directory of Open Access Journals (Sweden)

    Ruy J. Cruz Jr.

    2006-03-01

    Full Text Available RACIONAL: Apesar dos recentes avanços nos métodos de imagem e no cuidado dos doentes críticos, a taxa de mortalidade do abdome agudo vascular nas últimas duas décadas continua praticamente inalterada. OBJETIVOS: Avaliar as alterações imediatas dos gradientes regionais da pCO2 induzidas pela isquemia e reperfusão mesentérica. Determinar se outros marcadores sistêmicos de hipoperfusão esplâncnica são capazes de detectar precocemente as alterações circulatórias ocorridas na mucosa intestinal após oclusão da artéria mesentérica superior. MÉTODOS: Foram utilizados sete cães machos sem raça definida (20,6 ± 1,1 kg, submetidos a oclusão da artéria mesentérica superior por 45 minutos, sendo os animais observados por período adicional de 2 horas após a reperfusão. Variáveis hemodinâmicas sistêmicas foram avaliadas por meio de cateter arterial e Swan-Ganz. A perfusão do sistema digestório foi avaliada pela medida do fluxo sangüíneo da veia mesentérica superior e da serosa jejunal (fluxômetro ultra-sônico. Oferta, taxa de extração e consumo intestinal de oxigênio (DO2intest, TEO2intest e VO2intest, respectivamente, pH intramucoso (tonometria a gás e os gradientes veia mesentérica-arterial e mucosa-arterial da pCO2 (Dvm-a pCO2 e Dt-a pCO2, respectivamente, foram calculados. RESULTADOS: A oclusão da artéria mesentérica superior não esteve associada a alterações hemodinâmicas sistêmicas, mas pôde-se observar aumento significativo do Dvm-a pCO2 (1,7 ± 0,5 para 5,7 ± 1,8 mm Hg e do Dt-a pCO2 (8,2 ± 4,8 para 48,7 ± 4,6 mm Hg. Na fase de reperfusão observou-se redução da DO2intest (67,7 ± 9,9 para 38,8 ± 5,3 mL/min e conseqüente aumento da TEO2intest de 5,0 ± 1,1% para 12,4 ± 2,7%. Não houve correlação entre os gradientes da pCO2 analisados. CONCLUSÃO: A tonometria permite detectar de maneira precoce a redução de fluxo intestinal. Além disso, pudemos demonstrar que as variações dos

  12. Hydraulic considerations in sampling the unsaturated zone with inclined gravity lysimeters

    Science.gov (United States)

    Oaksford, E.T.

    1983-01-01

    Inclined gravity lysimeters as deep as 5.39 meters below land surface designed for sampling soil water in coarse sand under continuous ponding conditions, were shown to be capable of collecting 10 liters per hour at an infiltration rate of 0.5 meter per hour. This represents a capture efficiency of approximately 50%, a value observed in two similar but shallower lysimeters. When lysimeters are installed from a trench or observation manhole, soil-water samples can be taken under virtually undisturbed conditions, avoiding the soil disturbance and filtration associated with porous-cup vacuum lysimeters. Successful operation requires that the sampler be designed for the hydraulic characteristics of the soil from which the water sample is to be extracted. Criteria for lysimeter dimensions can be established on the basis of pressure heads experienced during sampling, can be induced to flow into the lysimeter by gradient manipulation. Observed head gradients outside the lysimeter ranged between 1.7 and 2.2 times those across the lysimeter, which would seem to explain the observed capture efficiency. (USGS)

  13. Measurement of precipitation using lysimeters

    Science.gov (United States)

    Fank, Johann; Klammler, Gernot

    2013-04-01

    Austria's alpine foothill aquifers contain important drinking water resources, but are also used intensively for agricultural production. These groundwater bodies are generally recharged by infiltrating precipitation. A sustainable water resources management of these aquifers requires quantifying real evapotranspiration (ET), groundwater recharge (GR), precipitation (P) and soil water storage change (ΔS). While GR and ΔS can be directly measured by weighable lysimeters and P by separate precipitation gauges, ET is determined by solving the climatic water balance ET = P GR ± ΔS. According to WMO (2008) measurement of rainfall is strongly influenced by precipitation gauge errors. Most significant errors result from wind loss, wetting loss, evaporation loss, and due to in- and out-splashing of water. Measuring errors can be reduced by a larger area of the measuring gaugés surface and positioning the collecting vessel at ground level. Modern weighable lysimeters commonly have a surface of 1 m², are integrated into their typical surroundings of vegetation cover (to avoid oasis effects) and allow scaling the mass change of monolithic soil columns in high measuring accuracy (0.01 mm water equivalent) and high temporal resolution. Thus, also precipitation can be quantified by measuring the positive mass changes of the lysimeter. According to Meissner et al. (2007) also dew, fog and rime can be determined by means of highly precise weighable lysimeters. Furthermore, measuring precipitation using lysimeters avoid common measuring errors (WMO 2008) at point scale. Though, this method implicates external effects (background noise, influence of vegetation and wind) which affect the mass time series. While the background noise of the weighing is rather well known and can be filtered out of the mass time series, the influence of wind, which blows through the vegetation and affects measured lysimeter mass, cannot be corrected easily since there is no clear relation between

  14. Quantifying soil evaporation and transpiration at the scale of a remote sensing pixel by extrapolating mini-lysimeter results with the aid of remote sensed surface temperatures

    Science.gov (United States)

    Voortman, B.; Bartholomeus, R.; Witte, J. M.

    2012-12-01

    Lysimeters are often used to measure evapotranspiration (Et) by changes in mass of a volume of soil. Precision lysimeters generate data of Et at a high resolution in the order of 0.02 to 0.05 mm. This resolution is often reported as the accuracy of the lysimeter, which is in fact the accuracy of the weighing device. Improper installation or design of lysimeters is often not accounted for when assessing their accuracy. In general, measurement errors due to improper environmental conditions will decrease with increasing surface area and depth of the lysimeter. This is primarily because a larger part of the lysimeter is unaffected by its boundaries and because heterogeneities in soil hydraulic properties and micro-climate are more averaged out. However, the cost of large systems make them unattractive and scientists often choose for more economical solutions, optimizing between lysimeter dimensions and costs. One of the difficulties when designing a lysimeter is controlling the boundary condition at the base of the lysimeter. In case of a freely draining lysimeter (atmospheric pressure at the bottom), the lower portion of the lysimeter must saturate to generate a hydraulic gradient in downward direction, after which the lysimeter starts to drain. In groundwater independent sites this will lead to a higher soil moisture content in the lysimeter in comparison with the surrounding soil. One could overcome this problem by using suction plates and vacuum pumps to set a suction level at the base of the lysimeter equal to the surrounding soil., In dry soils, however, suction plates may dry out beyond the air entry value of the ceramic material, which neutralizes the suction pressure. Furthermore, a sophisticated drainage system will increase the maintenance and construction cost of the lysimeter. Moisture conditions in lysimeters are difficult to control and whenever this affects the available water for rooting plants this will lead to erroneous measurements of Et. We

  15. Improving the inter-hemispheric gradient of total column atmospheric CO2 and CH4 in simulations with the ECMWF semi-Lagrangian atmospheric global model

    Science.gov (United States)

    Agusti-Panareda, Anna; Diamantakis, Michail; Bayona, Victor; Klappenbach, Friedrich; Butz, Andre

    2017-01-01

    It is a widely established fact that standard semi-Lagrangian advection schemes are highly efficient numerical techniques for simulating the transport of atmospheric tracers. However, as they are not formally mass conserving, it is essential to use some method for restoring mass conservation in long time range forecasts. A common approach is to use global mass fixers. This is the case of the semi-Lagrangian advection scheme in the Integrated Forecasting System (IFS) model used by the Copernicus Atmosphere Monitoring Service (CAMS) at the European Centre for Medium-Range Weather Forecasts (ECMWF).Mass fixers are algorithms with substantial differences in complexity and sophistication but in general of low computational cost. This paper shows the positive impact mass fixers have on the inter-hemispheric gradient of total atmospheric column-averaged CO2 and CH4, a crucial feature of their spatial distribution. Two algorithms are compared: the simple "proportional" and the more complex Bermejo-Conde schemes. The former is widely used by several Earth system climate models as well the CAMS global forecasts and analysis of atmospheric composition, while the latter has been recently implemented in IFS. Comparisons against total column observations demonstrate that the proportional mass fixer is shown to be suitable for the low-resolution simulations, but for the high-resolution simulations the Bermejo-Conde scheme clearly gives better results. These results have potential repercussions for climate Earth system models using proportional mass fixers as their resolution increases. It also emphasises the importance of benchmarking the tracer mass fixers with the inter-hemispheric gradient of long-lived greenhouse gases using observations.

  16. δ 13C of ecosystem-respired CO2 along a gradient of C3 woody-plant encroachment into C4 grassland

    Science.gov (United States)

    Sun, W.; Scott, R. L.; Resco, V.; Cable, J. M.; Huxman, T. E.; Williams, D. G.

    2006-12-01

    Woody plant encroachment into grassland has the potential to affect net primary production, in part by changing the sensitivities of photosynthesis and respiration to precipitation. Encroachment of mesquite (Prosopis) into floodplain sacaton (Sporobolus) grassland along the San Pedro River in southeastern Arizona has altered the magnitude and seasonal pattern of net ecosystem carbon exchange and ecosystem respiration. We hypothesized that because mesquite accesses ground water in these floodplain environments, its advancement and dominance in former grassland reduces the sensitivities of photosynthesis and autotrophic respiration to inputs of growing season precipitation. The observed elevated rates of ecosystem respiration following rainfall inputs are likely to result from microbial decomposition of labile organic matter derived from the highly productive mesquite trees. We used the Keeling plot method to monitor carbon-13 composition of nocturnal ecosystem-respired CO2 (δ 13CR) during the growing seasons of 2005 and 2006 at three sites spanning a gradient of mesquite invasion: C4 sacaton grassland, mixed mesquite/grass shrubland and C3 mesquite woodland. δ 13CR in the C4 grassland increased from -18.8‰ during the dry premonsoon period to -16.7‰ after the onset of summer rains, whereas δ 13CR in the mixed shrub/grass and woodland ecosystems declined from -20.9‰ to - 24‰ and from -20.8‰ to -24.7‰, respectively, following the onset of summer rains. The δ 13CR of respired CO2 was collected separately from soil, roots, leaves and surface litter to evaluate the contribution of each of these components to ecosystem respiration. Partitioning of ecosystem respiration using these isotope end-members and responses to short-term (days) changes in shallow (0-5cm) soil moisture content suggest that in former grassland now occupied by mesquite woodland, rainfall inputs primarily stimulate microbial decomposition and have little effect on autotrophic respiration

  17. Synthesis of porous MnCo2O4microspheres with yolk–shell structure induced by concentration gradient and the effect on their performance in electrochemical energy storage

    DEFF Research Database (Denmark)

    Huang, Guoyong; Yang, Yue; Sun, Hongyu

    2016-01-01

    In this study, novel spherical yolk–shell MnCo2O4 powders with concentration gradient have been synthesized. The porous microspheres with yolk–shell structure (2.00–3.00 μm in average diameter, ∼200 nm in thickness of shell) are built up by irregular nanoparticles attached to each other. It is sh......In this study, novel spherical yolk–shell MnCo2O4 powders with concentration gradient have been synthesized. The porous microspheres with yolk–shell structure (2.00–3.00 μm in average diameter, ∼200 nm in thickness of shell) are built up by irregular nanoparticles attached to each other...

  18. Noise Reduction Methods for Weighing Lysimeters

    Science.gov (United States)

    Mechanical vibration of the grass and crop weighing lysimeters, located at the University of California West Side Field Research and Extension Station at Five Points, CA generated noise in lysimeter mass measurements and reduced the quality of evapotranspiration (ET) data. Two filtering methods for ...

  19. Gradient Supercritical Carbon Dioxide Extraction and Analysis of Hemp Oil%火麻仁油超临界CO2梯度萃取与分析

    Institute of Scientific and Technical Information of China (English)

    董海胜; 朱景涛; 臧鹏; 张淑静; 陈斌

    2013-01-01

    以脱壳火麻仁为原料,采用超临界CO2梯度萃取火麻仁油,采用标准方法分别分析火麻仁油的脂肪酸组成及生育酚组成.结果表明:采用三段式超临界CO2梯度萃取,不同萃取阶段得到的火麻仁油脂肪酸组成存在一定差异,随着萃取压力及温度的升高,超临界CO2萃取出部分微量脂肪酸,包括:C20∶3n6、C22∶0及C24∶0.火麻仁油中生育酚以(β+γ)-生育酚为主,采用三段式超临界CO2梯度萃取火麻仁油,生育酚主要在前两个阶段被萃取出来.

  20. Lysimeter Kleče Sanitation

    Science.gov (United States)

    Bracic Zeleznik, Branka; Cencur Curk, Barbara

    2010-05-01

    Ljubljana field aquifer is the main source of drinking water for Ljubljana. About 35% of the recharge area is used for agriculture, predominantly for intensive vegetable production therefore two lysimeters were built in 1991 at the area of the water pumping station Klece in order to study natural nitrate percolation through the unsaturated zone. The lysimeters consist of two concrete pipes (radius: 0,9 m, depth: 2,0 m), filled with autochthon soil, sandy (pebbles of 2-4 cm diameter) gravel and drainage material, each 50 cm thick. Both lysimeters are connected with control shaft. The mean porosity of the lysimeter is 22 %. At the bottom of the lysimeter outflow a drain pipe leads into adjacent control shaft where outflow is measured with tipping bucket. The measurements of percolating water indicated that the southern lysimeter is damaged, because the part of the percolating water is lost through the bottom of the container. This was the reason for the removal of the southern lysimeter and replacing it with hydro-lysimeter. The monolith of 2 m height and 1,1m diameter will be cut from sandy gravel sediments on the area of the water pumping station. Inside the monolith tensiometers, TDR probes and suction cups will be installed in three levels in depths of 50 cm, 100 cm and 150 cm. Additionally 2 tensiometers for temperature and tension in the depths 190 cm to transfer field matrix potential into the lysimeter will be installed. Long term observations of water balance and nitrate percolation are very important in order to assess trends in groundwater recharge and nitrate content. Measurements and monitoring of NO3-N in percolated water from non-fertilised area give information about nitrate natural background, which helps to determine the correct use of plant fertilizers and enables prompt reactions to negative trends on the groundwater quality.

  1. CO2-Neutral Fuels

    NARCIS (Netherlands)

    Goede, A.; van de Sanden, M. C. M.

    2016-01-01

    Mimicking the biogeochemical cycle of System Earth, synthetic hydrocarbon fuels are produced from recycled CO2 and H2O powered by renewable energy. Recapturing CO2 after use closes the carbon cycle, rendering the fuel cycle CO2 neutral. Non-equilibrium molecular CO2 vibrations are key to high energy

  2. CO2-Neutral Fuels

    Science.gov (United States)

    Goede, Adelbert; van de Sanden, Richard

    2016-06-01

    Mimicking the biogeochemical cycle of System Earth, synthetic hydrocarbon fuels are produced from recycled CO2 and H2O powered by renewable energy. Recapturing CO2 after use closes the carbon cycle, rendering the fuel cycle CO2 neutral. Non-equilibrium molecular CO2 vibrations are key to high energy efficiency.

  3. CO2-Neutral Fuels

    NARCIS (Netherlands)

    Goede, A.; van de Sanden, M. C. M.

    2016-01-01

    Mimicking the biogeochemical cycle of System Earth, synthetic hydrocarbon fuels are produced from recycled CO2 and H2O powered by renewable energy. Recapturing CO2 after use closes the carbon cycle, rendering the fuel cycle CO2 neutral. Non-equilibrium molecular CO2 vibrations are key to high energy

  4. A lysimeter-based approach to quantify the impact of climate change on soil hydrological processes

    Science.gov (United States)

    Slawitsch, Veronika; Steffen, Birk; Herndl, Markus

    2016-04-01

    The predicted climate change involving increasing CO2 concentrations and increasing temperatures will have effects on both vegetation and soil properties and thus on the soil water balance. The aim of this work is to quantify the effects of changes in these climatic factors on soil hydrological processes and parameters. For this purpose data of six high precision weighable lysimeters will be used. The lysimeters are part of a Lysi-T-FACE concept, where free-air will be enriched with CO2 (FACE-Technique) and infrared heaters heat the plots for investigation on effects of increasing temperatures (T-FACE-Technique). The Lysi-T-FACE concept was developed on the „Clim Grass Site" at the HBLFA Raumberg-Gumpenstein (Styria, Austria) in 2011 and 2012 with a total of 54 experimental plots. These include six plots with lysimeters where the two climatic factors are varied in different combinations. On the basis of these grass land lysimeters the soil hydraulic parameters under different experimental conditions will be investigated. The lysimeters are equipped with TDR-Trime sensors and temperature sensors combined with tensiometers in different depths. In addition, a mechanical separation snow cover system is implemented to obtain a correct water balance in winter. To be able to infer differences between the lysimeters reliably a verification of functionalities and a plausibility check of the data from the lysimeters as well as adequate data corrections are needed. Both an automatic and a user-defined control including the recently developed filter method AWAT (Adaptive Window and Adaptive Threshold Filter) are combined with a visualisation tool using the software NI DIAdem. For each lysimeter the raw data is classified in groups of matric potentials, soil water contents and lysimeter weights. Values exceeding technical thresholds are eliminated and marked automatically. The manual data control is employed every day to obtain high precision seepage water weights. The

  5. Lysimeter Soil Retriever (LSR) - A tool for investigation on heterogeneity of the migration and structural changes

    Science.gov (United States)

    Reth, S.; Gierig, M.; Winkler, J. B.; Mueller, C. W.; Nitsche, C.; Seyfarth, M.

    2009-04-01

    Generally research fields of lysimeter studies scheduled as long term experiments. In the course of the studies, the lysimeters act more or less as a "black box". Usually the soil material is identified and analysed at the beginning of the experiments. But there is also a strong need to analyze the soil without disturbance of the soil structure after the experiments in order to obtain information about spatial and structural changes within the soil profile. The new technique of the Lysimeter Soil Retriever for the first time enables studies on the heterogeneous migration of percolating water, and changes of soil structure as well as soil organic matter (SOM) and biomass distribution, as well as the distribution of mycorrhiza and microbes in different depths on intact soil profiles. The main target by using the LSR is the preparation of an intact soil monolith from the field lysimeter and the immediate dissection into slices to enable a direct sampling of its soil environment at several depths. Distribution and composition of SOM, pF-values, soil porosity, as well as degradation of PAH were only a few parameters, which are determined at the different soil depths. In this presentation we give some examples for the different application of the LSR and the advantage for the experiments: - The soil of 8 lysimeters, planted with young beeches was retrieved after several years of fumigation with doubled atmospheric ozone concentrations and application of fungi. Due to the accurate sectioning of the soil monoliths a very dense and intensive soil sampling was possible. As the whole soil space of 8 lysimeters could be sampled, precise spatial information were obtained about the rapid formation of SOM depth gradients within the experiment duration. - After the investigation on the mobilization of polycyclic aromatic hydrocarbons (PAH) by the seepage water, the lysimeter soil was retrieved. Investigations on the microbiological degradation of the PAH were possible in the whole

  6. CO2 -Responsive polymers.

    Science.gov (United States)

    Lin, Shaojian; Theato, Patrick

    2013-07-25

    This Review focuses on the recent progress in the area of CO2 -responsive polymers and provides detailed descriptions of these existing examples. CO2 -responsive polymers can be categorized into three types based on their CO2 -responsive groups: amidine, amine, and carboxyl groups. Compared with traditional temperature, pH, or light stimuli-responsive polymers, CO2 -responsive polymers provide the advantage to use CO2 as a "green" trigger as well as to capture CO2 directly from air. In addition, the current challenges of CO2 -responsive polymers are discussed and the different solution methods are compared. Noteworthy, CO2 -responsive polymers are considered to have a prosperous future in various scientific areas.

  7. CO2 laser modeling

    Science.gov (United States)

    Johnson, Barry

    1992-01-01

    The topics covered include the following: (1) CO2 laser kinetics modeling; (2) gas lifetimes in pulsed CO2 lasers; (3) frequency chirp and laser pulse spectral analysis; (4) LAWS A' Design Study; and (5) discharge circuit components for LAWS. The appendices include LAWS Memos, computer modeling of pulsed CO2 lasers for lidar applications, discharge circuit considerations for pulsed CO2 lidars, and presentation made at the Code RC Review.

  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. Wearable CO2 sensor

    OpenAIRE

    Radu, Tanja; Fay, Cormac; Lau, King-Tong; Waite, Rhys; Diamond, Dermot

    2009-01-01

    High concentrations of CO2 may develop particularly in the closed spaces during fires and can endanger the health of emergency personnel by causing serious physiological effects. The proposed prototype provides real-time continuous monitoring of CO2 in a wearable configuration sensing platform. A commercially available electrochemical CO2 sensor was selected due to its selectivity, sensitivity and low power demand. This was integrated onto an electronics platform that performed signal capture...

  10. CO2 blood test

    Science.gov (United States)

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

  11. CO2 laser resurfacing.

    Science.gov (United States)

    Fitzpatrick, R E

    2001-07-01

    The CO2 Laser offers a variety of unique features in resurfacing facial photodamage and acne scarring. These include hemostasis, efficient removal of the epidermis in a single pass, thermally induced tissue tightening, and safe, predictable tissue interaction. Knowledge of these mechanisms will result in the capability of using the CO2 laser effectively and safely whether the goal is superficial or deep treatment.

  12. 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.

  13. Isooctane transport and remediation in soil using lysimeters

    Science.gov (United States)

    Colarieti, M. L.; Toscano, G.; Greco, G.

    2009-04-01

    The AMRA lysimeter station (near Piana di Monte Verna, Caserta, Italy) consists of eight weighable monolithic groundwater lysimeters fully equipped with sensors to provide continuous monitoring of temperature, humidity, water tension and weight, as well as ports for soil, liquid and gas sampling. An air-injection system allows to perform venting or sparging actions into contaminated soils and groundwater. A meteo station provides the indispensable data to evaluate the interactions between lysimeters and the meteorological phenomena on site. A preliminary experiment was performed last year to investigate the reactive transport of a NAPL-type contaminant under passive transport conditions and during an air-venting remediation action. 2,2,4-trimethylpentane (isooctane) was chosen as a representative contaminant from gasoline fuels. Four lysimeters containing undisturbed soil extracted from a former industrial site were used. Surface vegetation was cut to avoid leaves interference during contamination phase. Two lysimeters were contaminated by distributing a fixed amount of isooctane onto the soil surface, while two more lysimeters were left uncontaminated for reference. Only for one of the two contaminated lysimeters air was vented through a port at 150 cm depth. Air injection started 30 min after the contamination, lasted all the experiment time, and was applied also to one of the reference lysimeters. Gas samples were drawn periodically at different depths of the two contaminated lysimeters and analysed for isooctane content. Evolution of isooctane concentration profiles was different in the two contaminated lysimeters. In case of air-venting the contaminant maximum concentration was lower and the maximum depth reached by the contaminant was reduced. The time needed for a complete remediation action was compared with theoretical estimates computed according to normative procedures.

  14. ENVIRONMENTAL EVALUATION HANFORD GROUT LYSIMETER FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, G. A.

    1984-06-01

    The Hanford Grout Lysimeter Facility (HGLF) will be constructed to test the leaching and migration of radioactive and nonradioactive tracers embedded in a solidification agent (grout) under actual burial conditions in Hanford soil. Three different water treatment rates will be used: natural precipitation, 4 times and 8 times natural precipitation. Six lysimeters will be assembled. Each unit will measure 6 feet in diameter, 25 feet deep. Their construction and instrumentation will be performed during June-July, 1984 by J. A. Jones Construction Company and/or their subcontractor. The routine monitoring will be performed by Battelle staff over a 5.5 year period beginning in November 1984. The total estimated project cost will be approximately $200,000. The only anticipated environmental impact from this project will be a temporary nuisance-type local dust problem during the construction phase. This will not be a detriment to the environment. The results of dose calculations indicate that dose rates from the grouted waste cans will be quite low when the cans are covered by a meter or more of earth. Dose rates at or near the surface of the individual cans are not high enough to preclude their handling. The facility area will be fenced, posted as a radiation zone and operated under a radiation work procedure.

  15. 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...... Naturfredningsforening’s lokalkomité for Lyngby blev en del af samarbejdet for at få borgerne i kommunen involveret i arbejdet med at udvikle strategier for reduktion af CO2. Siden sommeren 2007 har Videnskabsbutikken DTU, Lyngby-Taarbæk kommune og Danmarks Naturfredningsforening i Lyngby-Taarbæk samarbejdet om analyse...... og innovation i forhold til CO2-strategier....

  16. Carbon balance, partitioning and photosynthetic acclimation in fruit-bearing grapevine (Vitis vinifera L. cv. Tempranillo) grown under simulated climate change (elevated CO2, elevated temperature and moderate drought) scenarios in temperature gradient greenhouses.

    Science.gov (United States)

    Salazar-Parra, Carolina; Aranjuelo, Iker; Pascual, Inmaculada; Erice, Gorka; Sanz-Sáez, Álvaro; Aguirreolea, Jone; Sánchez-Díaz, Manuel; Irigoyen, Juan José; Araus, José Luis; Morales, Fermín

    2015-02-01

    Although plant performance under elevated CO2 has been extensively studied in the past little is known about photosynthetic performance changing simultaneously CO2, water availability and temperature conditions. Moreover, despite of its relevancy in crop responsiveness to elevated CO2 conditions, plant level C balance is a topic that, comparatively, has received little attention. In order to test responsiveness of grapevine photosynthetic apparatus to predicted climate change conditions, grapevine (Vitis vinifera L. cv. Tempranillo) fruit-bearing cuttings were exposed to different CO2 (elevated, 700ppm vs. ambient, ca. 400ppm), temperature (ambient vs. elevated, ambient +4°C) and irrigation levels (partial vs. full irrigation). Carbon balance was followed monitoring net photosynthesis (AN, C gain), respiration (RD) and photorespiration (RL) (C losses). Modification of environment (13)C isotopic composition (δ(13)C) under elevated CO2 (from -10.30 to -24.93‰) enabled the further characterization of C partitioning into roots, cuttings, shoots, petioles, leaves, rachides and berries. Irrespective of irrigation level and temperature, exposure to elevated CO2 induced photosynthetic acclimation of plants. C/N imbalance reflected the inability of plants grown at 700ppm CO2 to develop strong C sinks. Partitioning of labeled C to storage organs (main stem and roots) did not avoid accumulation of labeled photoassimilates in leaves, affecting negatively Rubisco carboxylation activity. The study also revealed that, after 20 days of treatment, no oxidative damage to chlorophylls or carotenoids was observed, suggesting a protective role of CO2 either at current or elevated temperatures against the adverse effect of water stress.

  17. 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

  18. Using lysimeters to test the Penman Monteith actual evapotranspiration.

    Science.gov (United States)

    Ben Asher, Jiftah; Volinski, Roman; Zilberman, Arkadi; Bar Yosef, Beni; Silber, Avner

    2015-04-01

    Differences in actual transpiration (ETa) of banana plants were quantified in a lysimeter experiment. ETA was computed using instantaneous data from two weighing lysimeters and compared to PM (Penman-Monteith) model for ETa. Two critical problems were faced in this test. A) Estimating canopy and aerodynamic resistances ("rc" and "ra" respectively ) and B) converting the lysimeter changes in water volume ( LYv cm3 ) to ETa length units ( cm ). The two unknowns " rc" and "ra" were obtained from continuous measurements of the differences between canopy and air temperature (Tc - Ta). This difference was established by means of the infrared thermometry which was followed by numerical and analytical calculation of ETa using the modification suggested by R. Jackson to the PM model. The conversion of lysimeter volumetric units (LYv) to ETa length units was derived from the slope of cumulative LYv/ETa. This relationship was significantly linear (r2=0.97and 0.98.). Its slope was interpreted as "evaporating leaf area" which accounted for 1.8E4 cm2 in lysimeter 1 and 2.3E4 cm2.in lysimeter 2 . The comparison between LYv and PM model was acceptable even under very low ETa. The average of two lysimeters was 1.1mm/day (1.4 mm/day , LYv 1 and 0.8 LYv 2) while ETa calculated on the basis of PM model was 1.2 mm/day. It was concluded that although lysimeters are most accurate systems to measure ETa one of its disadvantages ( beside the high cost) is the volumetric output that in many cases should be supported by a one dimensional energy balance system. The PM model was found to be a reliable complementary tool to convert lysimeters volumetric output into conventional length units of ETa.

  19. CO2-neutral fuels

    Science.gov (United States)

    Goede, A. P. H.

    2015-08-01

    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 cycle is

  20. 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

  1. Geochemical Modeling of ILAW Lysimeter Water Extracts

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-22

    Geochemical modeling results of water extracts from simulated immobilized low-activity waste (ILAW) glasses, placed in lysimeters for eight years suggest that the secondary phase reaction network developed using product consistency test (PCT) results at 90°C may need to be modified for field conditions. For sediment samples that had been collected from near the glass samples, the impact of glass corrosion could be readily observed based upon the pH of their water extracts. For unimpacted sediments the pH ranged from 7.88 to 8.11 with an average of 8.04. Sediments that had observable impacts from glass corrosion exhibited elevated pH values (as high as 9.97). For lysimeter sediment samples that appear to have been impacted by glass corrosion to the greatest extent, saturation indices determined for analcime, calcite, and chalcedony in the 1:1 water extracts were near equilibrium and were consistent with the secondary phase reaction network developed using PCT results at 90°C. Fe(OH)3(s) also appears to be essentially at equilibrium in extracts impacted by glass corrosion, but with a solubility product (log Ksp) that is approximately 2.13 units lower than that used in the secondary phase reaction network developed using PCT results at 90°C. The solubilities of TiO2(am) and ZrO2(am) also appear to be much lower than that assumed in the secondary phase reaction network developed using PCT results at 90°C. The extent that the solubility of TiO2(am) and ZrO2(am) were reduced relative to that assumed in the secondary phase reaction network developed using PCT results at 90°C could not be quantified because the concentrations of Ti and Zr in the extracts were below the estimated quantification limit. Gibbsite was consistently highly oversaturated in the extract while dawsonite was at or near equilibrium. This suggests that dawsonite might be a more suitable phase for the secondary phase reaction network

  2. Long-term elevated atmospheric CO2 enhances forest productivity

    Science.gov (United States)

    Loecke, T. D.; Groffman, P. M.; Treseder, K. K.; LaDeau, S.

    2011-12-01

    Global atmospheric CO2 concentrations are increasing at historically unprecedented but ecologically gradual rates. The implications of this perturbation for carbon sequestration and feedback on global climate change are difficult to predict due in part to its gradual and largely uniform nature. We used long-term (>40 years) spatial gradients in atmospheric CO2 concentration, produced by spatially heterogeneous fossil fuel combustion along a rural to urban transect, to test the hypotheses that 1) rural to urban CO2 spatial gradients are useful analogs for gradual climate change and 2) higher atmospheric CO2 concentration promotes tree growth and C sequestration. Fossil fuel derived CO2 imparts a distinctive 14C isotopic signature on atmospheric CO2; as this CO2 is fixed into annual tree rings, a proxy for fossil fuel derived CO2 is preserved. Ten four-year tree ring segments were analyzed for α-cellulose 14C content by AMS from trees within 10 closed canopy forested sites in the Baltimore Maryland metropolitan area. Tree growth parameters were assessed by measuring the annual ring width change of 224 trees across the 10 sites. A hierarchical Bayesian model was constructed to determine the influence of CO2 concentration and other site and environmental factors on tree growth. Our proxy for historical CO2 concentrations indicates a detectable but diminishing spatial CO2 gradient across the rural to urban transect that ranged from a 5.6% gradient during the 1970s to a 1.4% gradient in recent years (2000-2008). This observation is consistent with urban deindustrialization and concurrent expansion of suburban development. As an analog for future atmospheric conditions, this spatial gradient is equivalent to a temporal gradient of ca. 15, 7.2, 9.8, 2.6 years of atmospheric CO2 rise during the past four decades. The CO2 spatial gradient had an overall positive effect on tree size adjusted ring width growth. Modeled air surface temperature differences among sites indicate

  3. Functional MRI of CO2 induced increase in cerebral perfusion

    DEFF Research Database (Denmark)

    Rostrup, Egill; Larsson, H B; Toft, P B

    1994-01-01

    The sensitivity of MR gradient echo imaging towards CO2 induced changes in cerebral blood flow was investigated in 10 normal subjects. The subjects were inhaling 5% and 7% CO2 and the experiments were carried out at 1.5 T (n = 6) and 2.0 T (n = 5), allowing a comparison of field strengths. Additi...

  4. Functional MRI of CO2 induced increase in cerebral perfusion

    DEFF Research Database (Denmark)

    Rostrup, Egill; Larsson, H B; Toft, P B;

    1994-01-01

    The sensitivity of MR gradient echo imaging towards CO2 induced changes in cerebral blood flow was investigated in 10 normal subjects. The subjects were inhaling 5% and 7% CO2 and the experiments were carried out at 1.5 T (n = 6) and 2.0 T (n = 5), allowing a comparison of field strengths...

  5. CO2 laser preionisation

    Science.gov (United States)

    Spiers, Gary D.

    1991-01-01

    The final report for work done during the reporting period of January 25, 1990 to January 24, 1991 is presented. A literature survey was conducted to identify the required parameters for effective preionization in TEA CO2 lasers and the methods and techniques for characterizing preionizers are reviewed. A numerical model of the LP-140 cavity was used to determine the cause of the transverse mode stability improvement obtained when the cavity was lengthened. The measurement of the voltage and current discharge pulses on the LP-140 were obtained and their subsequent analysis resulted in an explanation for the low efficiency of the laser. An assortment of items relating to the development of high-voltage power supplies is also provided. A program for analyzing the frequency chirp data files obtained with the HP time and frequency analyzer is included. A program to calculate the theoretical LIMP chirp is also included and a comparison between experiment and theory is made. A program for calculating the CO2 linewidth and its dependence on gas composition and pressure is presented. The program also calculates the number of axial modes under the FWHM of the line for a given resonator length. A graphical plot of the results is plotted.

  6. Membraneless water filtration using CO2

    Science.gov (United States)

    Shin, Sangwoo; Shardt, Orest; Warren, Patrick; Stone, Howard

    2016-11-01

    Water purification technologies such as ultrafiltration and reverse osmosis utilize porous membranes to remove suspended particles and solutes. These membranes, however, cause many drawbacks such as a high pumping cost and a need for periodic replacement due to fouling. Here we show an alternative membraneless method for separating suspended particles by exposing the colloidal suspension to CO2. Dissolution of CO2 into the suspension creates solute gradients that drive phoretic motion of particles, or so-called diffusiophoresis. Due to the large diffusion potential built up by the dissociation of carbonic acid, colloidal particles move either away from or towards the gas-liquid interface depending on their surface charge. Our findings suggest a means to separate particles without membranes or filters, thus reducing operating and maintenance costs. Using the directed motion of particles induced by exposure to CO2, we demonstrate a scalable, continuous flow, membraneless particle filtration process that exhibits very low pressure drop and is essentially free from fouling.

  7. Spatial extrapolation of lysimeter results using thermal infrared imaging

    Science.gov (United States)

    Voortman, B. R.; Bosveld, F. C.; Bartholomeus, R. P.; Witte, J. P. M.

    2016-12-01

    Measuring evaporation (E) with lysimeters is costly and prone to numerous errors. By comparing the energy balance and the remotely sensed surface temperature of lysimeters with those of the undisturbed surroundings, we were able to assess the representativeness of lysimeter measurements and to quantify differences in evaporation caused by spatial variations in soil moisture content. We used an algorithm (the so called 3T model) to spatially extrapolate the measured E of a reference lysimeter based on differences in surface temperature, net radiation and soil heat flux. We tested the performance of the 3T model on measurements with multiple lysimeters (47.5 cm inner diameter) and micro lysimeters (19.2 cm inner diameter) installed in bare sand, moss and natural dry grass. We developed different scaling procedures using in situ measurements and remotely sensed surface temperatures to derive spatially distributed estimates of Rn and G and explored the physical soundness of the 3T model. Scaling of Rn and G considerably improved the performance of the 3T model for the bare sand and moss experiments (Nash-Sutcliffe efficiency (NSE) increasing from 0.45 to 0.89 and from 0.81 to 0.94, respectively). For the grass surface, the scaling procedures resulted in a poorer performance of the 3T model (NSE decreasing from 0.74 to 0.70), which was attributed to effects of shading and the difficulty to correct for differences in emissivity between dead and living biomass. The 3T model is physically unsound if the field scale average air temperature, measured at an arbitrarily chosen reference height, is used as input to the model. The proposed measurement system is relatively cheap, since it uses a zero tension (freely draining) lysimeter which results are extrapolated by the 3T model to the unaffected surroundings. The system is promising for bridging the gap between ground observations and satellite based estimates of E.

  8. Ambient CO2, fish behaviour and altered GABAergic neurotransmission: exploring the mechanism of CO2-altered behaviour by taking a hypercapnia dweller down to low CO2 levels.

    Science.gov (United States)

    Regan, Matthew D; Turko, Andy J; Heras, Joseph; Andersen, Mads Kuhlmann; Lefevre, Sjannie; Wang, Tobias; Bayley, Mark; Brauner, Colin J; Huong, Do Thi Thanh; Phuong, Nguyen Thanh; Nilsson, Göran E

    2016-01-01

    Recent studies suggest that projected rises of aquatic CO2 levels cause acid-base regulatory responses in fishes that lead to altered GABAergic neurotransmission and disrupted behaviour, threatening fitness and population survival. It is thought that changes in Cl(-) and HCO3 (-) gradients across neural membranes interfere with the function of GABA-gated anion channels (GABAA receptors). So far, such alterations have been revealed experimentally by exposing species living in low-CO2 environments, like many oceanic habitats, to high levels of CO2 (hypercapnia). To examine the generality of this phenomenon, we set out to study the opposite situation, hypothesizing that fishes living in typically hypercapnic environments also display behavioural alterations if exposed to low CO2 levels. This would indicate that ion regulation in the fish brain is fine-tuned to the prevailing CO2 conditions. We quantified pH regulatory variables and behavioural responses of Pangasianodon hypophthalmus, a fish native to the hypercapnic Mekong River, acclimated to high-CO2 (3.1 kPa) or low-CO2 (0.04 kPa) water. We found that brain and blood pH was actively regulated and that the low-CO2 fish displayed significantly higher activity levels, which were reduced after treatment with gabazine, a GABAA receptor blocker. This indicates an involvement of the GABAA receptor and altered Cl(-) and HCO3 (-) ion gradients. Indeed, Goldman calculations suggest that low levels of environmental CO2 may cause significant changes in neural ion gradients in P. hypophthalmus. Taken together, the results suggest that brain ion regulation in fishes is fine-tuned to the prevailing ambient CO2 conditions and is prone to disruption if these conditions change.

  9. Investigation of the interfacial properties for CO2-methanol and CO2-ethanol mixtures%CO2-甲醇和CO2-乙醇体系的界面性质

    Institute of Scientific and Technical Information of China (English)

    付东

    2011-01-01

    An equation of state (EOS) applicable for the interfacial properties of CO2-methanol and CO2-ethanol mixtures was established by combining the cross-association EOS and the density gradient theory (DGT). The correlated surface tensions of CO2-ethanol mixtures agreed well with the experimental data. The results illustrated the temperature and pressure dependence of the cross-association between CO2 and alcohol hydroxyls in the whole vapor-liquid surface, and the influence of the cross-association on the calculation of the surface tensions of binary mixtures.%在交叉缔合的均相状态方程的基础上,结合密度梯度理论(density gradient theory,DGT),建立了适用于CO2-甲醇和CO2-乙醇二元体系界面性质研究的状态方程,对CO2-乙醇体系表面张力的关联结果与实验值吻合良好.阐明了CO2分子与甲醇分子和乙醇分子之间的交叉缔合作用对二元体系表面张力计算结果的影响,以及界面相中CO2与醇羟基之间的交叉缔合与温度和压力之间的关系.

  10. Status of SRNL radiological field lysimeter experiment-Year 1

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Roberts, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Bagwell, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2013-10-01

    The Savannah River National Laboratory (SRNL) Radiological Field Lysimeter Experiment is a one-of-a-kind field facility designed to study radionuclide geochemical processes at a larger spatial scale (from grams to tens of kilograms sediment) and temporal scale (from months to 10 years) than is readily afforded through laboratory studies. The lysimeter facility is intended to capture the natural heterogeneity of moisture and temperature regimes in the vadose zone, the unsaturated subsurface region between the surface soil and the underlying aquifer. The 48 lysimeter columns, which contain various radionuclides (and stable iodine), were opened to rainfall infiltration on July 5, 2012. The objective of this report is to provide a status of the lysimeter facility operations and to compile data collected during FY13, including leachate volume, rainfall, and soil moisture and temperature in situ probe data. Radiological leachate data are not presented in this document but will be the subject of a separate document.1 Leachate samples were collected quarterly and shipped to Clemson University for radiological analyses. Rainfall, leachate volume, moisture and temperature probe data were collected continuously. During operations of the facility this year, there were four safety or technical concerns that required additional maintenance: 1) radioactivity was detected in one of the overflow bottles (captured water collected from the secondary containment that does not come in contact with the radiological source material); 2) rainwater accumulated within the sample-bottle storage sheds; 3) overflow containers collected more liquid than anticipated; and 4) significant spider infestation occurred in the sample-bottle storage sheds. To address the first three concerns, each of the lysimeter columns was re-plumbed to improve and to minimize the number of joint unions. To address the fourth concern regarding spiders, new sample-bottle water sheds were purchased and a pest control

  11. Field Lysimeter Test Facility: Protective barrier test results (FY 1990, the third year)

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, M.D.; Gee, G.W.

    1990-11-01

    The Field Lysimeter Test Facility (FLTF) was constructed to test protective barriers for isolating low-level radioactive and hazardous wastes from the biosphere. Protective barriers are specially configured earth materials placed over near-surface wastes to prevent intrusion of water, plants, and animals. Low-level radioactive waste is stored in near-surface repositories at the Hanford Site and can be transported into the biosphere by water, plants, and animals. The purpose of the FLTF is to measure water balance within barriers as precipitation is partitioned to evaporation (including transpiration), storage, and drainage. Runoff was prevented by raised edges on the lysimeters. Water balance in protective barriers depends on the water-holding capacity of the soil, the gradient of a potential, and the conductivity of the underlying capillary barrier. Current barrier design uses soil with a high water storage capacity and a capillary barrier underlying the soil to increase its water storage capacity. This increased storage capacity is to hold water, which would normally drain, near the the surface where evaporation can cycle it back to the atmosphere. 7 refs., 23 figs., 5 tabs.

  12. Modeling global atmospheric CO2 with improved emission inventories and CO2 production from the oxidation of other carbon species

    Energy Technology Data Exchange (ETDEWEB)

    Nassar, Ray [University of Toronto; Jones, DBA [University of Toronto; Suntharalingam, P [University of East Anglia, Norwich, United Kingdom; Chen, j. [University of Toronto; Andres, Robert Joseph [ORNL; Wecht, K. J. [Harvard University; Yantosca, R. M. [Harvard University; Kulawik, SS [Jet Propulsion Laboratory, Pasadena, CA; Bowman, K [Jet Propulsion Laboratory, Pasadena, CA; Worden, JR [Jet Propulsion Laboratory, Pasadena, CA; Machida, T [National Institute for Environmental Studies, Japan; Matsueda, H [Meteorological Research Institute, Japan

    2010-01-01

    The use of global three-dimensional (3-D) models with satellite observations of CO2 in inverse modeling studies is an area of growing importance for understanding Earth s carbon cycle. Here we use the GEOS-Chem model (version 8-02-01) CO2 mode with multiple modifications in order to assess their impact on CO2 forward simulations. Modifications include CO2 surface emissions from shipping (0.19 PgC yr 1), 3-D spatially-distributed emissions from aviation (0.16 PgC yr 1), and 3-D chemical production of CO2 (1.05 PgC yr 1). Although CO2 chemical production from the oxidation of CO, CH4 and other carbon gases is recognized as an important contribution to global CO2, it is typically accounted for by conversion from its precursors at the surface rather than in the free troposphere. We base our model 3-D spatial distribution of CO2 chemical production on monthly-averaged loss rates of CO (a key precursor and intermediate in the oxidation of organic carbon) and apply an associated surface correction for inventories that have counted emissions of CO2 precursors as CO2. We also explore the benefit of assimilating satellite observations of CO into GEOS-Chem to obtain an observation-based estimate of the CO2 chemical source. The CO assimilation corrects for an underestimate of atmospheric CO abundances in the model, resulting in increases of as much as 24% in the chemical source during May June 2006, and increasing the global annual estimate of CO2 chemical production from 1.05 to 1.18 Pg C. Comparisons of model CO2 with measurements are carried out in order to investigate the spatial and temporal distributions that result when these new sources are added. Inclusion of CO2 emissions from shipping and aviation are shown to increase the global CO2 latitudinal gradient by just over 0.10 ppm (3%), while the inclusion of CO2 chemical production (and the surface correction) is shown to decrease the latitudinal gradient by about 0.40 ppm (10%) with a complex spatial structure

  13. Modeling global atmospheric CO2 with improved emission inventories and CO2 production from the oxidation of other carbon species

    Directory of Open Access Journals (Sweden)

    K. W. Bowman

    2010-12-01

    Full Text Available The use of global three-dimensional (3-D models with satellite observations of CO2 in inverse modeling studies is an area of growing importance for understanding Earth's carbon cycle. Here we use the GEOS-Chem model (version 8-02-01 CO2 mode with multiple modifications in order to assess their impact on CO2 forward simulations. Modifications include CO2 surface emissions from shipping (~0.19 Pg C yr−1, 3-D spatially-distributed emissions from aviation (~0.16 Pg C yr−1, and 3-D chemical production of CO2 (~1.05 Pg C yr−1. Although CO2 chemical production from the oxidation of CO, CH4 and other carbon gases is recognized as an important contribution to global CO2, it is typically accounted for by conversion from its precursors at the surface rather than in the free troposphere. We base our model 3-D spatial distribution of CO2 chemical production on monthly-averaged loss rates of CO (a key precursor and intermediate in the oxidation of organic carbon and apply an associated surface correction for inventories that have counted emissions of CO2 precursors as CO2. We also explore the benefit of assimilating satellite observations of CO into GEOS-Chem to obtain an observation-based estimate of the CO2 chemical source. The CO assimilation corrects for an underestimate of atmospheric CO abundances in the model, resulting in increases of as much as 24% in the chemical source during May–June 2006, and increasing the global annual estimate of CO2 chemical production from 1.05 to 1.18 Pg C. Comparisons of model CO2 with measurements are carried out in order to investigate the spatial and temporal distributions that result when these new sources are added. Inclusion of CO2 emissions from shipping and aviation are shown to increase the global CO2 latitudinal gradient by just over 0.10 ppm (~3%, while the inclusion of CO2 chemical production (and the surface correction is shown to decrease the latitudinal gradient by about 0.40 ppm (~10% with a complex

  14. Forecasting global atmospheric CO2

    Directory of Open Access Journals (Sweden)

    A. Agustí-Panareda

    2014-05-01

    Full Text Available A new global atmospheric carbon dioxide (CO2 real-time forecast is now available as part of the pre-operational 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 CO2 forecasting system is that the land surface, including vegetation CO2 fluxes, is modelled online within the IFS. Other CO2 fluxes are prescribed from inventories and from off-line statistical and physical models. The CO2 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 CO2 on different temporal and spatial scales compared to observations. The modulation of the amplitude of the CO2 diurnal cycle by near-surface winds and boundary layer height is generally well represented in the forecast. The CO2 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 CO2 fluxes from vegetation compared to using equivalent monthly mean fluxes with a diurnal cycle. However, biases in the modelled CO2 fluxes also lead to accumulating errors in the CO2 forecast. These biases vary with season with an underestimation of the amplitude of the seasonal cycle both for the CO2 fluxes compared to total optimized fluxes and the atmospheric CO2 compared to observations. The largest biases in the atmospheric CO2 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 CO2 analyses based on the assimilation of CO2 satellite retrievals, as they

  15. India Co2 Emissions

    Science.gov (United States)

    Sharan, S.; Diffenbaugh, N. S.

    2010-12-01

    created a balance in between the “developed” and developing countries. If India was producing the same amounts of emissions per capita as the it would have a total of 20 billion metric tons of CO2 emissions annually.

  16. 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.

  17. Instrumentation of Lysimeter Experiments and Monitoring of Soil Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, T.; Tallos, A.; Millan, R.; Vera, R.; Recreo, F.

    2004-07-01

    This study forms part of the project Mercurio and Recuperation de Terrenos Afectados por Mercurio Ambiental (RETAMA), which determines the behaviour of mercury in the soil-plant system within the area of Almaden. The objective of this work is to instrument lysimeters with a set of electronic sensors to monitor physical and chemical soil parameters (moisture content, soil temperature, soil water matrix potential. Eh and pH) over a period of a complete vegetation cycle for selected crops. Physical and chemical soil analyses have been carried out on samples two soil profiles marking the extreme perimeter where the lysimeters were extracted. The monitoring data obtained every half hour show that the physicochemical conditions of the soils in the lysimeter can be correlated with the type of cultivation in the lysimeters. The results for parameters such as soil water matrix potential and the soil temperature reflect the diurnal changes; and fluctuations of the Eh can be related to the biological activities in the soils and are within oxid and suboxic conditions. Slight fluctuations have been observed for the pH and constant volumetric moisture content is maintained during the period of no hydric stress. (Author) 16 refs.

  18. New sciences enabled by the new SABER CO2 data

    Science.gov (United States)

    Yue, J.; Russell, J. M., III; Jian, Y.; Rezac, L.; Mlynczak, M. G.; Garcia, R. R.; Gan, Q.; Lopez-Puertas, M.; Salinas, C. C. J.; Chang, L. C.

    2016-12-01

    The new SABER CO2 mixing ratio dataset includes the longest CO2 record in the mesosphere and lower thermosphere (MLT) in existence [Rezac et al., 2015]. It spans from 2003 to 2015 with extensive spatial and temporal coverage (daytime only). This unique dataset provides the opportunity to study several important scientific topics in the Earth's MLT. The first is the long-term anthropogenic increase of CO2. Along with ACE-FTS CO2 data [Emmert et al., 2012], we discovered that the increase rate of CO2 above 80 km is greater than 5% per decade, which cannot be predicted by climate models. One possible explanation is that the eddy diffusivity in the MLT may also be increasing. The second project is to derive eddy diffusion from global mean SABER CO2. This parameter is extremely difficult to measure on a global scale, but by averaging the global mean SABER CO2 and removing vertical advection, we can estimate the eddy diffusion coefficient using a 1D photochemical model. The derived eddy diffusion due to gravity wave breaking is critical for understanding seasonal composition changes in the thermosphere. The third scientific study is to examine global-scale waves modulating the CO2 mixing ratio. We found that there is no wave feature in CO2 below 80 km as CO2 is well mixed. The CO2 wave feature is related to both the mean CO2 vertical and meridional gradient and wave induced vertical/meridional displacements. In general, the new SABER CO2 data allows us to better understand the short-term and long-term dynamics in the MLT region. This paper will show examples of SABER results and discuss the potential of the data set for study of dynamics phenomenon in the MLT.

  19. Lower responsiveness of canopy evapotranspiration rate than of leaf stomatal conductance to open-air CO2 elevation in rice.

    Science.gov (United States)

    Shimono, Hiroyuki; Nakamura, Hirofumi; Hasegawa, Toshihiro; Okada, Masumi

    2013-08-01

    An elevated atmospheric CO2 concentration ([CO2 ]) can reduce stomatal conductance of leaves for most plant species, including rice (Oryza sativa L.). However, few studies have quantified seasonal changes in the effects of elevated [CO2 ] on canopy evapotranspiration, which integrates the response of stomatal conductance of individual leaves with other responses, such as leaf area expansion, changes in leaf surface temperature, and changes in developmental stages, in field conditions. We conducted a field experiment to measure seasonal changes in stomatal conductance of the uppermost leaves and in the evapotranspiration, transpiration, and evaporation rates using a lysimeter method. The study was conducted for flooded rice under open-air CO2 elevation. Stomatal conductance decreased by 27% under elevated [CO2 ], averaged throughout the growing season, and evapotranspiration decreased by an average of 5% during the same period. The decrease in daily evapotranspiration caused by elevated [CO2 ] was more significantly correlated with air temperature and leaf area index (LAI) rather than with other parameters of solar radiation, days after transplanting, vapor-pressure deficit and FAO reference evapotranspiration. This indicates that higher air temperatures, within the range from 16 to 27 °C, and a larger LAI, within the range from 0 to 4 m(2)  m(-2) , can increase the magnitude of the decrease in evapotranspiration rate caused by elevated [CO2 ]. The crop coefficient (i.e. the evapotranspiration rate divided by the FAO reference evapotranspiration rate) was 1.24 at ambient [CO2 ] and 1.17 at elevated [CO2 ]. This study provides the first direct measurement of the effects of elevated [CO2 ] on rice canopy evapotranspiration under open-air conditions using the lysimeter method, and the results will improve future predictions of water use in rice fields.

  20. Enzymes in CO2 Capture

    DEFF Research Database (Denmark)

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

    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......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 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...

  1. 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).

  2. CO2 flux estimation errors associated with moist atmospheric processes

    Directory of Open Access Journals (Sweden)

    S. Pawson

    2012-04-01

    Full Text Available Vertical transport by moist sub-grid scale processes such as deep convection is a well-known source of uncertainty in CO2 source/sink inversion. However, a dynamical link between moist transport, satellite CO2 retrievals, and source/sink inversion has not yet been established. Here we examine the effect of moist processes on (1 synoptic CO2 transport by Version-4 and Version-5 NASA Goddard Earth Observing System Data Assimilation System (NASA-DAS meteorological analyses, and (2 source/sink inversion. We find that synoptic transport processes, such as fronts and dry/moist conveyors, feed off background vertical CO2 gradients, which are modulated by sub-grid vertical transport. The implication for source/sink estimation is two-fold. First, CO2 variations contained in moist poleward moving air masses are systematically different from variations in dry equatorward moving air. Moist poleward transport is hidden from orbital sensors on satellites, causing a sampling bias, which leads directly to continental scale source/sink estimation errors of up to 0.25 PgC yr−1 in northern mid-latitudes. Second, moist processes are represented differently in GEOS-4 and GEOS-5, leading to differences in vertical CO2 gradients, moist poleward and dry equatorward CO2 transport, and therefore the fraction of CO2 variations hidden in moist air from satellites. As a result, sampling biases are amplified, causing source/sink estimation errors of up to 0.55 PgC yr−1 in northern mid-latitudes. These results, cast from the perspective of moist frontal transport processes, support previous arguments that the vertical gradient of CO2 is a major source of uncertainty in source/sink inversion.

  3. CO2 Flux Estimation Errors Associated with Moist Atmospheric Processes

    Science.gov (United States)

    Parazoo, N. C.; Denning, A. S.; Kawa, S. R.; Pawson, S.; Lokupitiya, R.

    2012-01-01

    Vertical transport by moist sub-grid scale processes such as deep convection is a well-known source of uncertainty in CO2 source/sink inversion. However, a dynamical link between vertical transport, satellite based retrievals of column mole fractions of CO2, and source/sink inversion has not yet been established. By using the same offline transport model with meteorological fields from slightly different data assimilation systems, we examine sensitivity of frontal CO2 transport and retrieved fluxes to different parameterizations of sub-grid vertical transport. We find that frontal transport feeds off background vertical CO2 gradients, which are modulated by sub-grid vertical transport. The implication for source/sink estimation is two-fold. First, CO2 variations contained in moist poleward moving air masses are systematically different from variations in dry equatorward moving air. Moist poleward transport is hidden from orbital sensors on satellites, causing a sampling bias, which leads directly to small but systematic flux retrieval errors in northern mid-latitudes. Second, differences in the representation of moist sub-grid vertical transport in GEOS-4 and GEOS-5 meteorological fields cause differences in vertical gradients of CO2, which leads to systematic differences in moist poleward and dry equatorward CO2 transport and therefore the fraction of CO2 variations hidden in moist air from satellites. As a result, sampling biases are amplified and regional scale flux errors enhanced, most notably in Europe (0.43+/-0.35 PgC /yr). These results, cast from the perspective of moist frontal transport processes, support previous arguments that the vertical gradient of CO2 is a major source of uncertainty in source/sink inversion.

  4. Monitoring the performance of an alternative cover using caisson lysimeters

    Energy Technology Data Exchange (ETDEWEB)

    Waugh, W.J.; Smith, G.M.; Mushovic, P.S.

    2004-02-29

    The U.S. Department of Energy (DOE) office in Grand Junction, Colorado, and the U.S. Environmental Protection Agency (EPA), Region 8, collaborated on a series of field lysimeter studies to design and monitor the performance of an alternative cover for a uranium mill tailings disposal cell at the Monticello, Utah, Superfund Site. Because groundwater recharge is naturally limited at Monticello in areas with thick loess soils, DOE and EPA chose to design a cover for Monticello using local soils and a native plant community to mimic this natural soilwater balance. Two large drainage lysimeters fabricated of corrugated steel culvert lined with high-density polyethylene were installed to evaluate the hydrological and ecological performance of an alternative cover design constructed in 2000 on the disposal cell. Unlike conventional, lowpermeability designs, this cover relies on (1) the water storage capacity of a 163-cm soil “sponge” layer overlying a sand-and-gravel capillary barrier to retain precipitation while plants are dormant and (2) native vegetation to remove precipitation during the growing season. The sponge layer consists of a clay loam subsoil compacted to 1.65 g/cm2 in one lysimeter and a loam topsoil compacted to 1.45 g/cm2 in the other lysimeter, representing the range of as-built conditions constructed in the nearby disposal cell cover. About 0.1 mm of drainage occurred in both lysimeters during an average precipitation year and before they were planted, an amount well below the EPA target of <3.0 mm/yr. However, the cover with less compacted loam topsoil sponge had a 40% greater water storage capacity than the cover with overly compacted clay loam subsoil sponge. The difference is attributable in part to higher green leaf area and water extraction by plants in the loam topsoil. The lesson learned is that seemingly subtle differences in soil types, sources, and compaction can result in salient differences in performance. Diverse, seeded communities of

  5. THE INFLUENCE OF CO2 ON WELL CEMENT

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Međimurec

    2010-12-01

    Full Text Available Carbon capture and storage is one way to reduce emissions of greenhouse gases in the atmosphere. Underground gas storage operations and CO2 sequestration in aquifers relay on both the proper wellbore construction and sealing properties of the cap rock. CO2 injection candidates may be new wells or old wells. In both cases, the long-term wellbore integrity (up to 1 000 years is one of the key performance criteria in the geological storage of CO2. The potential leakage paths are the migration CO2 along the wellbore due to poor cementation and flow through the cap rock. The permeability and integrity of the set cement will determine how effective it is in preventing the leakage. The integrity of the cap rock is assured by an adequate fracture gradient and by sufficient set cement around the casing across the cap rock and without a micro-annulus. CO2 storage in underground formations has revived the researc of long term influence of the injected CO2 on Portland cements and methods for improving the long term efficiency of the wellbore sealant. Some researchers predicted that set cement will fail when exposed to CO2 leading to potential leakage to the atmosphere or into underground formations that may contain potable water. Other researchers show set cement samples from 30 to 50 year-old wells (CO2 EOR projects that have maintained sealing integrity and prevented CO2 leakage, in spite of some degree of carbonation. One of reasons for the discrepancy between certain research lab tests and actual field performance measurements is the absence of standard protocol for CO2 resistance-testing devices, conditions, or procedures. This paper presents potential flow paths along the wellbore, CO2 behaviour under reservoir conditions, and geochemical alteration of hydrated Portland cement due to supercritical CO2 injection.

  6. Influence of Landfill Operation and Tropical Seasonal Variation on Leachate Characteristics: Results from Lysimeter Experiment

    Directory of Open Access Journals (Sweden)

    Islam M. Rafizul

    2012-01-01

    Full Text Available This study demonstrates the influence of lysimeter operational condition and tropical seasonal variation of leachate characteristics generated from municipal solid waste (MSW deposited in landfill lysimeter at KUET campus, Bangladesh. Three different situations of landfill were considered here as well as both the open dump lysimeter-A having a base liner and sanitary landfill lysimeter-B and C at two different types of cap liner were simulated. The leachate characteristics, leachate generation and climatic influence parameter had been continually monitored, from June 2008 to May 2010. This period covers both dry and rainy season. The leachate generation followed the rainfall pattern and the open dump lysimeter-A without top cover was recorded to have the highest leachate generation. Moreover, the open dump lysimeter-A had lower concentration and load of total kjeldahl nitrogen (TKN, ammonia nitrogen (NH4-N and dissolved organic carbon (DOC, while chemical oxygen demand (COD and biological oxygen demand (BOD5 concentration were higher compared with sanitary lysimeter-B and C. On the other hand, sanitary lysimeter-B, not only had lowest leachate generation, but also produced reasonably low COD and BOD5 concentration compared with open dump lysimeter-A. Based on evaluated results, it was also concluded that metal concentrations which were comparatively higher in leachate of open dump lysimeter were Ca and K, however, the heavy metal concentrations of Cd, Cu, Zn and Mn, and those apparently lower were metals of Na, Mg and Fe as well as heavy metals of Cr, Pb and Ni. However, significant release of heavy metals under open dump lysimeter was observed compared to sanitary lysimeter. Moreover, meaningful correlation between DOC and leaching of Cu and Pb was observed. Result reveals that lysimeter operational mode had direct effect on leachate quality. Finally, it can be concluded that the knowledge of leachate quality will be useful in planning and

  7. 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.

  8. Groundwater recharge measurements in gravel sandy sediments with monolith lysimeter

    Science.gov (United States)

    Bracic Zeleznik, Branka; Souvent, Petra; Cencur Curk, Barbara; Zupanc, Vesna

    2013-04-01

    Ljubljana field aquifer is recharging through precipitation and the river Sava, which has the snow-rain flow regime. The sediments of the aquifer have high permeability and create fast flow as well as high regeneration of the dynamic reserves of the Ljubljana field groundwater resource. Groundwater recharge is vulnerable to climate change and it is very important for drinking water supply management. Water stored in the soil and less permeable layers is important for water availability under extreme weather conditions. Measurements of water percolation through the vadose zone provide important input for groundwater recharge assessment and estimation of contaminant migration from land surface to the groundwater. Knowledge of the processes governing groundwater recharge in the vadose zone is critical to understanding the overall hydrological cycle and quantifying the links between land uses and groundwater quantity and quality. To improve the knowledge on water balance for Ljubljana field aquifer we establish a lysimeter for measurements of processes in unsaturated zone in well field Kleče. The type of lysimeter is a scientific lysimeter designed to solve the water balance equation by measuring the mass of the lysimeter monolith as well as that of outflow tank with high accuracy and high temporal resolution. We evaluated short period data, however the chosen month demonstrates weather extremes of the local climate - relatively dry periods, followed by high precipitation amount. In time of high water usage of vegetation only subsequent substantial precipitation events directly results in water flow towards lower layers. At the same time, gravely layers of the deeper parts of the unsaturated zone have little or no capacity for water retention, and in the event that water line leaves top soil, water flow moves downwards fairly quickly. On one hand this confirms high recharge capacity of Ljubljana field aquifer from precipitation on green areas; on the other hand it

  9. Eddy covariance and lysimeter measurements of moisture fluxes over supraglacial debris

    Science.gov (United States)

    Brock, Benjamin

    2015-04-01

    Supraglacial debris covers have the potential to evaporate large quantities of water derived from either sub-debris ice melt or precipitation. Currently, knowledge of evaporation and condensation rates in supraglacial debris is limited due to the difficulty of making direct measurements. This paper presents eddy covariance and lysimeter measurements of moisture fluxes made over a 0.2 m debris layer at Miage debris covered glacier, Italian Alps, during the 2013 ablation season. The meteorological data are complimented by reflectometer measurements of volumetric water fraction in the saturated and vadose zones of the debris layer. The lysimeters were designed specifically to mimic the debris cover and were embedded within the debris matrix, level with the surface. Over the ablation season, the latent heat flux is dominated by evaporation, and the flux magnitude closely follows the daily cycle of daytime solar heating and night time radiative cooling of debris. Mean flux values are of the order of 1 kg m-2 day-1, but often higher for short periods following rainfall. Condensation rates are relatively small and restricted to night time and humid conditions when the debris-atmosphere vapour pressure gradient reverses due to relatively warm air overlying cold debris. The reflectometer measurements provide evidence of vertical water movement through capillary rise in the upper part of the fine-grained debris layer, just above the saturated horizon, and demonstrate how debris bulk water content increases after rainfall. The latent heat flux responds directly to changes in wind speed, indicating that atmospheric turbulence can penetrate porous upper debris layers to the saturated horizon. Hence, vertical sorting of debris sediments and antecedent rainfall are important in determining evaporation rates, in addition to current meteorological conditions. Comparison of lysimeter measurements with rainfall data provides an estimate that between 45% and 89% of rainfall is

  10. Method for tracing simulated CO2 leak in terrestrial environment with a 13CO2 tracer

    Science.gov (United States)

    Moni, Christophe; Rasse, Daniel

    2013-04-01

    Facilities for the geological storage of carbon dioxide (CO2) as part of carbon capture and storage (CCS) schemes will be designed to prevent any leakage from the defined 'storage complex'. However, developing regulations and guidance throughout the world (e.g. the EC Directive and the USEPA Vulnerability Evaluation Framework) recognize the importance of assessing the potential for environmental impacts from CO2 storage. RISCS, a European (FP7) project, aims to improve understanding of those impacts that could plausibly occur in the hypothetical case that unexpected leakage occurs. As part of the RISCS project the potential impacts that an unexpected CO2 leaks might have on a cropland ecosystems was investigated. A CO2 exposure field experiment based on CO2 injection at 85 cm depth under an oats culture was designed. To facilitate the characterization of the simulated leaking zone the gas used for injection was produced from natural gas and had a δ13C of -46‰. The aim of the present communication is to depict how the injected gas was traced within the soil-vegetation-atmosphere continuum using 13CO2 continuous cavity ring-down spectrometry (CRDS). Four subsurface experimental injection plots (6m x 3m) were set up. In order to test the effects of different intensity of leakage, the field experiment was designed as to create a longitudinal CO2 gradient for each plot. For this purpose gas supply pipes were inserted at one extremity of each plot at the base of a 45 cm thick layer of sand buried 40 cm below the surface under the clayey plough layer of Norwegian moraine soils. Soil CO2 concentration and isotopic signature were punctually recorded: 1) in the soil at 20 cm depth at 6 positions distributed on the central transect, 2) at the surface following a (50x50 cm) grid sampling pattern, and 3) in the canopy atmosphere at 10, 20, 30 cm along three longitudinal transects (seven sampling point per transect). Soil CO2 fluxes and isotopic signature were finally

  11. Simulation of CO2 concentrations at Tsukuba tall tower using WRF-CO2 tracer transport model

    Indian Academy of Sciences (India)

    Srabanti Ballav; Prabir K Patra; Yousuke Sawa; Hidekazu Matsueda; Ahoro Adachi; Shigeru Onogi; Masayuki Takigawa; Utpal K De

    2016-02-01

    Simulation of carbon dioxide (CO2) at hourly/weekly intervals and fine vertical resolution at the continental or coastal sites is challenging because of coarse horizontal resolution of global transport models. Here the regional Weather Research and Forecasting (WRF) model coupled with atmospheric chemistry is adopted for simulating atmospheric CO2 (hereinafter WRF-CO2) in nonreactive chemical tracer mode. Model results at horizontal resolution of 27 × 27 km and 31 vertical levels are compared with hourly CO2 measurements from Tsukuba, Japan (36.05°N, 140.13°E) at tower heights of 25 and 200 m for the entire year 2002. Using the wind rose analysis, we find that the fossil fuel emission signal from the megacity Tokyo dominates the diurnal, synoptic and seasonal variations observed at Tsukuba. Contribution of terrestrial biosphere fluxes is of secondary importance for CO2 concentration variability. The phase of synoptic scale variability in CO2 at both heights are remarkably well simulated the observed data (correlation coefficient >0.70) for the entire year. The simulations of monthly mean diurnal cycles are in better agreement with the measurements at lower height compared to that at the upper height. The modelled vertical CO2 gradients are generally greater than the observed vertical gradient. Sensitivity studies show that the simulation of observed vertical gradient can be improved by increasing the number of vertical levels from 31 in the model WRF to 37 (4 below 200 m) and using the Mellor–Yamada–Janjic planetary boundary scheme. These results have large implications for improving transport model simulation of CO2 over the continental sites.

  12. Using long-term lysimeter data to analyze hydrological trends

    Science.gov (United States)

    Puetz, Thomas; Hendricks-Franssen, Harrie-Jan; Roesseler, Anne-Kathrin; Vereecken, Harry

    2014-05-01

    Evapotranspiration (ET) is a major component of the terrestrial water cycle. Recent studies based on analysis of experimental and observations-based data have shown that over the last decades the magnitude of evapotranspiration (both potential and actual) has been affected by global climate change although the sign and size of the change in ET differ strongly between regions around the globe, as well as between datasets (e.g. Teuling et al. 2009, Jung et al. 2010, Sheffield et al. 2012). Basically, there are two approaches that are available to measure actual evapotranspiration in situ (e.g. Seneviratne et al. 2010): the measurement from micrometeorological approaches (in particular the Eddy Covariance method) and the determination of evapotranspiration by measuring the components of the soil water balance. Evett et al. (2012) showed that Eddy Covariance measurements of actual evapotranspiration obtained in irrigated cotton fields was 31 to 45% lower than estimates obtained from soil water balance measurements using lysimeters. Forcing the closure of the energy balance with more data than typically available at EC stations, the difference was still about 17%. Despite the fact that lysimeter systems, especially the weighing based systems, are ideal tools to determine actual evapotranspiration no global assessment has been made of available data at present that might be valuable to assess the impact of climate change on actual evapotranspiration. A screening of literature showed that many data are either not reported or made available through research reports rather than peer reviewed literature. Typically lysimeter studies have been used for well-designed experimental studies for the assessment of flow and transport processes in cropped systems that were limited in time. Still at present, we have lysimeter systems operational that have long term time series available on soil hydrological fluxes. Recently, a few studies were reported that analyzed long term series of

  13. ACCURACY OF CO2 SENSORS

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.; Faulkner, David; Sullivan, Douglas P.

    2008-10-01

    Are the carbon dioxide (CO2) sensors in your demand controlled ventilation systems sufficiently accurate? The data from these sensors are used to automatically modulate minimum rates of outdoor air ventilation. The goal is to keep ventilation rates at or above design requirements while adjusting the ventilation rate with changes in occupancy in order to save energy. Studies of energy savings from demand controlled ventilation and of the relationship of indoor CO2 concentrations with health and work performance provide a strong rationale for use of indoor CO2 data to control minimum ventilation rates1-7. However, this strategy will only be effective if, in practice, the CO2 sensors have a reasonable accuracy. The objective of this study was; therefore, to determine if CO2 sensor performance, in practice, is generally acceptable or problematic. This article provides a summary of study methods and findings ? additional details are available in a paper in the proceedings of the ASHRAE IAQ?2007 Conference8.

  14. 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

  15. Critical Considerations for Accurate Soil CO2 Flux Measurement

    Science.gov (United States)

    Xu, L.; Furtaw, M.; Madsen, R.; Welles, J.; Demetriades-Shah, T.; Anderson, D.; Garcia, R.; McDermitt, D.

    2005-12-01

    Soil respiration is a significant component of the carbon balance for an ecosystem, but the environmental (soil moisture, rain event, temperature etc.) and biological (photosynthesis, LAI etc.) factors that contribute to soil respiration remain poorly understood. This limits our ability to understand the carbon budget at the ecosystem level making it difficult to predict the impacts of climate change. Two important reasons for this poor understanding have been the difficulty in making accurate soil respiration measurements and the lack of continuous and long-term soil respiration data at sufficiently fine temporal and spatial scales. To meet these needs, we have developed a new automated multiplexing system, the LI-8100M, for obtaining reliable soil CO2 flux data at high spatial and temporal resolution. The system has the capability to continuously measure the soil CO2 flux at up to 16 locations. Soil CO2 flux is driven primarily by the CO2 diffusion gradient across the soil surface. Ideally, the flux measurement should be made without affecting the diffusion gradient and without having any chamber-induced pressure perturbation. In a closed-chamber system the slope of dCO2/dt is required to compute the flux. To obtain the slope of dCO2/dt, the chamber CO2 concentration must be allowed to rise. Consequently, soil CO2 flux will be affected because of the decreased CO2 diffusion gradient. To minimize the impact of decreased CO2 diffusion gradient on CO2 flux measurement in LI-8100M, the chamber CO2 concentration versus time is fitted with an exponential function. Soil CO2 flux is then estimated by calculating the initial slope from the exponential function at time zero when the chamber touches the soil, and that is when the chamber CO2 concentration is equal to the ambient. Our results show that the flux estimated from a linear function, the widely used method, could underestimate CO2 flux by more than 10% as compared with that from the exponential function. An

  16. 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.

  17. Monitoring subsurface CO2 storage

    NARCIS (Netherlands)

    Winthaegen, P.; Arts, R.; Schroot, B.M.

    2005-01-01

    An overview is given of various currently applied monitoring techniques for CO2 storage. Techniques are subdivided in correspondence to their applicability for monitoring three distinct realms. These are: - the atmosphere and the near-surface; - the overburden (including faults and wells); - the

  18. Upscaling of lysimeter measurements to regional groundwater nitrate distribution

    Science.gov (United States)

    Klammler, Gernot; Fank, Johann; Kupfersberger, Hans; Rock, Gerhard

    2015-04-01

    For many European countries nitrate leaching from the soil zone into the aquifer due to surplus application of mineral fertilizer and animal manure by farmers constitutes the most important threat to groundwater quality. This is a diffuse pollution situation and measures to change agricultural production have to be investigated at the aquifer scale to safeguard drinking water supply from shallow groundwater resources Lysimeters are state-of-the-art measurements for water and solute fluxes through the unsaturated zone towards groundwater at the point scale, but due to regional heterogeneities (especially concerning soil conditions) lysimeters cannot provide aquifer-wide groundwater recharge and solute leaching. Thus, in this work the numerical simulation model SIMWASER/STOTRASIM (Stenitzer, 1988; Feichtinger, 1998) for quantifying groundwater recharge and nitrate leaching at aquifer scale is applied. Nevertheless, according to Groenendijk et al. (2014) a model calibration by means of lysimeter measurements is essential, since uncalibrated models are generally far from acceptable. Thus, a lysimeter provides the basis for the parameterization of numerical simulation models. To quantify also the impact on regional nitrate distribution in the groundwater, we couple the unsaturated zone model SIMWASER/STOTRASIM with the saturated groundwater flow and solute transport model FELOW (Diersch, 2009) sequentially. In principal, the problem could be solved by the 3 dimensional equation describing variable saturated groundwater flow and solute transport. However, this is computationally prohibitive due to the temporal and spatial scope of the task, particularly in the framework of running numerous simulations to compromise between conflicting interests (i.e. good groundwater status and high agricultural yield). To account for the unknown regional distribution of crops grown and amount, timing and kind of fertilizers used a stochastic tool (Klammler et al, 2011) is developed that

  19. Excitation of CO2/+/ by electron impact on CO2

    Science.gov (United States)

    Mentall, J. E.; Coplan, M. A.; Kushlis, R. J.

    1973-01-01

    Consideration of a discrepancy concerning the correct value of the cross section for excitation of the CO2(+) B state by electron impact on CO2. It is suggested that the reason for the disparate results obtained by various authors for the B state can be traced to a calibration error due to scattered light. In particular, the tungsten filament lamps used in the experiments cited have very low intensity at wavelengths below 3000 A where the B state emissions occur, so that even a small amount of scattered light in the spectrometer will produce a large error in the measured cross section. In a remeasurement of the cross section for excitation of the B state at an energy of 150 eV it was found that at 2900 A the scattered light signal, if uncorrected for, would introduce an error of about 50%.

  20. Análise direcional do fluxo sangüíneo miocárdico após revascularização transmiocárdica com laser de CO2: estudo através da ressonância magnética com imagens de gradiente ultra-rápido

    Directory of Open Access Journals (Sweden)

    DALLAN Luís A.

    2002-01-01

    Full Text Available OBJETIVO: Avaliar a direção do fluxo sangüíneo miocárdico de pacientes submetidos à revascularização transmiocárdica com laser de CO2 (RTML, através de estudos de imagem por ressonância magnética. CASUÍSTICA E MÉTODOS: Dez pacientes submetidos a RTML com laser de CO2 (potência de 800 W foram estudados através da ressonância magnética de gradiente ultra-rápido (Gradiente eco-EPI de seqüência híbrida, visando avaliar o direcionamento da perfusão miocárdica após o procedimento. Gadolínio - DTPA (0,1 mmol/kg foi injetado "em bolus" através de veia periférica em velocidade de 5 ml/seg em repouso durante o pico de "stress" induzido por dipiridamol. Foi avaliada sua distribuição miocárdica através da obtenção de curvas de intensidade de sinal no tempo para as diversas sub-regiões do miocárdio, em modelo de 24 segmentos. RESULTADOS: Após período médio de 14,7 meses, pudemos detectar isquemia em ao menos uma das paredes ventriculares em 6 (60% pacientes. Em 1 (10% paciente pode-se notar que o fluxo sangüíneo miocárdico dirigia-se do subendocárdio para o subepicárdio, ao contrário dos demais. CONCLUSÃO: A ressonância magnética, usando a técnica de perfusão miocárdica de primeira passagem, permitiu observar o direcionamento do fluxo sangüíneo miocárdico. Em um dos pacientes, a presença de fluxo miocárdico invertido (do endocárdio para o epicárdio sugeriu a patência dos canais realizados através da RTML.

  1. Water balance measurements and simulations of maize plants on lysimeters

    Science.gov (United States)

    Heinlein, Florian; Biernath, Christian; Klein, Christian; Thieme, Christoph; Priesack, Eckart

    2016-04-01

    In Central Europe expected major aspects of climate change are a shift of precipitation events and amounts towards winter months, and the general increase of extreme weather events like heat waves or summer droughts. This will lead to strongly changing regional water availability and will have an impact on future crop growth, water use efficiency and yields. Therefore, to estimate future crop yields by growth models accurate descriptions of transpiration as part of the water balance is important. In this study, maize was grown on weighing lysimeters (sowdate: 24 April 2013). Transpiration was determined by sap flow measurement devices (ICT International Pty Ltd, Australia) using the Heat-Ratio-Method: two temperature probes, 0.5 cm above and below a heater, detect a heat pulse and its speed which allows the calculation of sap flow. Water balance simulations were executed with different applications of the model framework Expert-N. The same pedotransfer and hydraulic functions and the same modules to simulate soil water flow, soil heat and nitrogen transport, nitrification, denitrification and mineralization were used. Differences occur in the chosen potential evapotranspiration ETpot (Penman-Monteith ASCE, Penman-Monteith FAO, Haude) and plant modules (SPASS, CERES). In all simulations ETpot is separated into a soil and a plant part using the leaf are index (LAI). In a next step, these parts are reduced by soil water availability. The sum of these parts is the actual evapotranspiration ETact which is compared to the lysimeter measurements. The results were analyzed from Mid-August to Mid-September 2013. The measured sap flow rates show clear diurnal cycles except on rainy days. The SPASS model is able to simulate these diurnal cycles, overestimates the measurements on rainy days and at the beginning of the analyzed period, and underestimates transpiration on the other days. The main reason is an overestimation of potential transpiration Tpot due to too high

  2. 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....

  3. Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations.

    Science.gov (United States)

    Sengupta, Aditi; Wang, Yadi; Meira Neto, Antonio A; Matos, Katarena A; Dontsova, Katerina; Root, Rob; Neilson, Julie W; Maier, Raina M; Chorover, Jon; Troch, Peter A

    2016-09-11

    Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled Earth-system processes. Such knowledge is imperative in improving predictions of hydro-biogeochemical cycles, especially under climate change scenarios. We present an experimental method, designed to capture sub-surface heterogeneity of an initially homogeneous soil system. This method is based on destructive sampling of a soil lysimeter designed to simulate a small-scale hillslope. A weighing lysimeter of one cubic meter capacity was divided into sections (voxels) and was excavated layer-by-layer, with sub samples being collected from each voxel. The excavation procedure was aimed at detecting the incipient heterogeneity of the system by focusing on the spatial assessment of hydrological, geochemical, and microbiological properties of the soil. Representative results of a few physicochemical variables tested show the development of heterogeneity. Additional work to test interactions between hydrological, geochemical, and microbiological signatures is planned to interpret the observed patterns. Our study also demonstrates the possibility of carrying out similar excavations in order to observe and quantify different aspects of soil-development under varying environmental conditions and scale.

  4. End-inspiratory rebreathing reduces the end-tidal to arterial PCO2 gradient in mechanically ventilated pigs

    NARCIS (Netherlands)

    Fierstra, Jorn; Machina, Matthew; Battisti-Charbonney, Anne; Duffin, James; Fisher, Joseph Arnold; Minkovich, Leonid

    Noninvasive monitoring of the arterial partial pressures of CO2 (PaCO2) of critically ill patients by measuring their end-tidal partial pressures of CO2 (PetCO(2)) would be of great clinical value. However, the gradient between PetCO(2) and PaCO2 (Pet-aCO(2)) in such patients typically varies over a

  5. End-inspiratory rebreathing reduces the end-tidal to arterial PCO2 gradient in mechanically ventilated pigs

    NARCIS (Netherlands)

    Fierstra, Jorn; Machina, Matthew; Battisti-Charbonney, Anne; Duffin, James; Fisher, Joseph Arnold; Minkovich, Leonid

    2011-01-01

    Noninvasive monitoring of the arterial partial pressures of CO2 (PaCO2) of critically ill patients by measuring their end-tidal partial pressures of CO2 (PetCO(2)) would be of great clinical value. However, the gradient between PetCO(2) and PaCO2 (Pet-aCO(2)) in such patients typically varies over a

  6. An Improved CO2-Crude Oil Minimum Miscibility Pressure Correlation

    Directory of Open Access Journals (Sweden)

    Hao Zhang

    2015-01-01

    Full Text Available Minimum miscibility pressure (MMP, which plays an important role in miscible flooding, is a key parameter in determining whether crude oil and gas are completely miscible. On the basis of 210 groups of CO2-crude oil system minimum miscibility pressure data, an improved CO2-crude oil system minimum miscibility pressure correlation was built by modified conjugate gradient method and global optimizing method. The new correlation is a uniform empirical correlation to calculate the MMP for both thin oil and heavy oil and is expressed as a function of reservoir temperature, C7+ molecular weight of crude oil, and mole fractions of volatile components (CH4 and N2 and intermediate components (CO2, H2S, and C2~C6 of crude oil. Compared to the eleven most popular and relatively high-accuracy CO2-oil system MMP correlations in the previous literature by other nine groups of CO2-oil MMP experimental data, which have not been used to develop the new correlation, it is found that the new empirical correlation provides the best reproduction of the nine groups of CO2-oil MMP experimental data with a percentage average absolute relative error (%AARE of 8% and a percentage maximum absolute relative error (%MARE of 21%, respectively.

  7. 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

  8. The importance of crop growth modeling to interpret the Δ14CO2 signature of annual plants

    NARCIS (Netherlands)

    Bozhinova, D.; Combe, M.; Palstra, S. W. L.; Meijer, H. A. J.; Krol, M. C.; Peters, W.

    2013-01-01

    The C-14/C abundance in CO2((CO2)-C-14) promises to provide useful constraints on regional fossil fuel emissions and atmospheric transport through the large gradients introduced by anthropogenic activity. The currently sparse atmospheric (CO2)-C-14 monitoring network can potentially be augmented by

  9. Surface Condensation of CO2 onto Kaolinite

    Energy Technology Data Exchange (ETDEWEB)

    Schaef, Herbert T.; Glezakou, Vassiliki Alexandra; Owen, Antionette T.; Ramprasad, Sudhir; Martin, Paul F.; McGrail, B. Peter

    2014-02-11

    The fundamental adsorption behavior of gaseous and supercritical carbon dioxide (CO2) onto poorly crystalline kaolinite (KGa-2) at conditions relevant to geologic sequestration has been investigated using a quartz crystal microbalance (QCM) and density functional theory (DFT) methods. The QCM data indicated linear adsorption of CO2 (0-0.3 mmol CO2/g KGa-2) onto the kaolinite surface up through the gaseous state (0.186 g/cm3). However in the supercritical region, CO2 adsorption increases dramatically, reaching a peak (0.9-1.0 mmol CO2/g KGa-2) near 0.43 g/cm3, before declining rapidly to surface adsorption values equivalent or below gaseous CO2. This adsorption profile was not observed with He or N2. Comparative density functional studies of CO2 interactions with kaolinite surface models rule out CO2 intercalation and confirm that surface adsorption is favored up to approximately 0.35 g/cm3 of CO2, showing distorted T-shaped CO2-CO2 clustering, typical of supercritical CO2 aggregation over the surface as the density increases. Beyond this point, the adsorption energy gain for any additional CO2 becomes less than the CO2 interaction energy (~0.2 eV) in the supercritical medium resulting in overall desorption of CO2 from the kaolinite surface.

  10. Monitoring Atmospheric CO2 From Space: Challenge & Approach

    Science.gov (United States)

    Lin, Bing; Harrison, F. Wallace; Nehrir, Amin; Browell, Edward; Dobler, Jeremy; Campbell, Joel; Meadows, Byron; Obland, Michael; Kooi, Susan; Fan, Tai-Fang; Ismail, Syed

    2015-01-01

    Atmospheric CO2 is the key radiative forcing for the Earth's climate and may contribute a major part of the Earth's warming during the past 150 years. Advanced knowledge on the CO2 distributions and changes can lead considerable model improvements in predictions of the Earth's future climate. Large uncertainties in the predictions have been found for decades owing to limited CO2 observations. To obtain precise measurements of atmospheric CO2, certain challenges have to be overcome. For an example, global annual means of the CO2 are rather stable, but, have a very small increasing trend that is significant for multi-decadal long-term climate. At short time scales (a second to a few hours), regional and subcontinental gradients in the CO2 concentration are very small and only in an order of a few parts per million (ppm) compared to the mean atmospheric CO2 concentration of about 400 ppm, which requires atmospheric CO2 space monitoring systems with extremely high accuracy and precision (about 0.5 ppm or 0.125%) in spatiotemporal scales around 75 km and 10-s. It also requires a decadal-scale system stability. Furthermore, rapid changes in high latitude environments such as melting ice, snow and frozen soil, persistent thin cirrus clouds in Amazon and other tropical areas, and harsh weather conditions over Southern Ocean all increase difficulties in satellite atmospheric CO2 observations. Space lidar approaches using Integrated Path Differential Absorption (IPDA) technique are considered to be capable of obtaining precise CO2 measurements and, thus, have been proposed by various studies including the 2007 Decadal Survey (DS) of the U.S. National Research Council. This study considers to use the Intensity-Modulated Continuous-Wave (IM-CW) lidar to monitor global atmospheric CO2 distribution and variability from space. Development and demonstration of space lidar for atmospheric CO2 measurements have been made through joint adventure of NASA Langley Research Center and

  11. Modeling Atmospheric CO2 Processes to Constrain the Missing Sink

    Science.gov (United States)

    Kawa, S. R.; Denning, A. S.; Erickson, D. J.; Collatz, J. C.; Pawson, S.

    2005-01-01

    We report on a NASA supported modeling effort to reduce uncertainty in carbon cycle processes that create the so-called missing sink of atmospheric CO2. Our overall objective is to improve characterization of CO2 source/sink processes globally with improved formulations for atmospheric transport, terrestrial uptake and release, biomass and fossil fuel burning, and observational data analysis. The motivation for this study follows from the perspective that progress in determining CO2 sources and sinks beyond the current state of the art will rely on utilization of more extensive and intensive CO2 and related observations including those from satellite remote sensing. The major components of this effort are: 1) Continued development of the chemistry and transport model using analyzed meteorological fields from the Goddard Global Modeling and Assimilation Office, with comparison to real time data in both forward and inverse modes; 2) An advanced biosphere model, constrained by remote sensing data, coupled to the global transport model to produce distributions of CO2 fluxes and concentrations that are consistent with actual meteorological variability; 3) Improved remote sensing estimates for biomass burning emission fluxes to better characterize interannual variability in the atmospheric CO2 budget and to better constrain the land use change source; 4) Evaluating the impact of temporally resolved fossil fuel emission distributions on atmospheric CO2 gradients and variability. 5) Testing the impact of existing and planned remote sensing data sources (e.g., AIRS, MODIS, OCO) on inference of CO2 sources and sinks, and use the model to help establish measurement requirements for future remote sensing instruments. The results will help to prepare for the use of OCO and other satellite data in a multi-disciplinary carbon data assimilation system for analysis and prediction of carbon cycle changes and carbodclimate interactions.

  12. SRNL RADIONUCLIDE FIELD LYSIMETER EXPERIMENT: BASELINE CONSTRUCTION AND IMPLEMENTATION

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, K.; Kaplan, D.; Bagwell, L.; Powell, B.; Almond, P.; Emerson, H.; Hixon, A.; Jablonski, J.; Buchanan, C.; Waterhouse, T.

    2012-10-17

    The purpose of this document is to compile information regarding experimental design, facility design, construction, radionuclide source preparation, and path forward for the ten year Savannah River National Laboratory (SRNL) Radionuclide Field Lysimeter Experiment at the Savannah River Site (SRS). This is a collaborative effort by researchers at SRNL and Clemson University. The scientific objectives of this study are to: Study long-term radionuclide transport under conditions more representative of vadose zone conditions than laboratory experiments; Provide more realistic quantification of radionuclide transport and geochemistry in the vadose zone, providing better information pertinent to radioactive waste storage solutions than presently exists; Reduce uncertainty and improve justification for geochemical models such as those used in performance assessments and composite analyses.

  13. Integrating lysimeter drainage and eddy covariance flux measurements in a groundwater recharge model

    DEFF Research Database (Denmark)

    Vasquez, Vicente; Thomsen, Anton Gårde; Iversen, Bo Vangsø;

    2015-01-01

    Field scale water balance is difficult to characterize because controls exerted by soils and vegetation are mostly inferred from local scale measurements with relatively small support volumes. Eddy covariance flux and lysimeters have been used to infer and evaluate field scale water balances...... because they have larger footprint areas than local soil moisture measurements.. This study quantifies heterogeneity of soil deep drainage (D) in four 12.5 m2 repacked lysimeters, compares evapotranspiration from eddy covariance (ETEC) and mass balance residuals of lysimeters (ETwbLys), and models D...

  14. Studying water budget of paved urban sites using weighable lysimeters

    Science.gov (United States)

    Rim, Yong-Nam; Nehls, Thomas; Litz, Norbert; Trinks, Steffen; Wessolek, Gerd

    2010-05-01

    Our lysimeter study addresses high-resolution analysis of the water balance of permeable pavements used for sidewalks and streets. Berlin's typical pavers, "Bernburg cobble stone" and "concrete paver" are analysed for actual evaporation, runoff and groundwater recharge. To achieve the reasonable boundary condition realistic seam material were bed in surface construction. The lysimeter bodies, filled with construction sand, stand in 1.5 m deep stainless cave on a scale with a 100g/sec resolution. The seepage water is captured by four suction plates with a suction of 63 hPa. To measure the run-off separately, special gutters are set up directly along the surface edge. This gutter leads the run-off water immediately to a separate discharge pipe and the run-off will be measured with a resolution of 0.0005 mm/sec; no water gets lost within this procedure. A dynamic runoff coefficient could be gained for a span of typical rainfall intensities. We will present runoff coefficients (RC) from both pavements as functions of the rainfall intensity, based on about 40 individual precipitation events. We could show that the rainfall intensity is the best predictor for the runoff behaviour. Concrete pavers can cause runoff with higher RC at lower intensity. However, for intensities > 0.1 mm/min their RCs tend to increase slower than those of mosaic cobble stone pavements. RCs might not be dependent on pavements during strong precipitation events. The measured RC are typical for the rainfall characteristic of Berlin, Germany and should not be used for other climate regions. First, the controlling variable must be identified and incorporated into process based models. Such models are essential for the prediction of urban evaporation so as to develop new urban water and climate management strategies.

  15. CyclicCO2R: production of cyclic carbonates from CO2 using renewable feedstocks

    NARCIS (Netherlands)

    Kimball, E.; Schuurbiers, C.A.H.; Zevenbergen, J.F.; Håkonsen, S.F.; Heyn, R.; Offermans, W.; Leitner, W.; Ostapowicz, T.; Müller, T. E.; Mul, G.; North, M.; Ngomsik-Fanselow, A.F.; Sarron, E.; Sigurbjörnsson, O.; Schäffner, B.

    2013-01-01

    The consortium behind CyclicCO2R wants to kick-start the implementation of CO2 utilization technologies by converting CO2 into a high value-added product, thus providing a showcase that inspires industry to further develop technologies utilizing CO2 as a sustainable raw material and valorizing CO2

  16. CyclicCO2R: production of cyclic carbonates from CO2 using renewable feedstocks

    NARCIS (Netherlands)

    Kimball, E.; Schuurbiers, C.A.H.; Zevenbergen, J.F.; Håkonsen, S.F.; Heyn, R.; Offermans, W.; Leitner, W.; Ostapowicz, T.; Müller, T. E.; Mul, G.; North, M.; Ngomsik-Fanselow, A.F.; Sarron, E.; Sigurbjörnsson, O.; Schäffner, B.

    2013-01-01

    The consortium behind CyclicCO2R wants to kick-start the implementation of CO2 utilization technologies by converting CO2 into a high value-added product, thus providing a showcase that inspires industry to further develop technologies utilizing CO2 as a sustainable raw material and valorizing CO2 i

  17. CO2 exsolution - challenges and opportunities in subsurface flow management

    Science.gov (United States)

    Zuo, Lin; Benson, Sally

    2014-05-01

    In geological carbon sequestration, a large amount of injected CO2 will dissolve in brine over time. Exsolution occurs when pore pressures decline and CO2 solubility in brine decreases, resulting in the formation of a separate CO2 phase. This scenario occurs in storage reservoirs by upward migration of carbonated brine, through faults, leaking boreholes or even seals, driven by a reverse pressure gradient from CO2 injection or ground water extraction. In this way, dissolved CO2 could migrate out of storage reservoirs and form a gas phase at shallower depths. This paper summarizes the results of a 4-year study regarding the implications of exsolution on storage security, including core-flood experiments, micromodel studies, and numerical simulation. Micromodel studies have shown that, different from an injected CO2 phase, where the gas remains interconnected, exsolved CO2 nucleates in various locations of a porous medium, forms disconnected bubbles and propagates by a repeated process of bubble expansion and snap-off [Zuo et al., 2013]. A good correlation between bubble size distribution and pore size distribution is observed, indicating that geometry of the pore space plays an important role in controlling the mobility of brine and exsolved CO2. Core-scale experiments demonstrate that as the exsolved gas saturation increases, the water relative permeability drops significantly and is disproportionately reduced compared to drainage relative permeability [Zuo et al., 2012]. The CO2 relative permeability remains very low, 10-5~10-3, even when the exsolved CO2 saturation increases to over 40%. Furthermore, during imbibition with CO2 saturated brines, CO2 remains trapped even under relatively high capillary numbers (uv/σ~10-6) [Zuo et al., submitted]. The water relative permeability at the imbibition endpoint is 1/3~1/2 of that with carbonated water displacing injected CO2. Based on the experimental evidence, CO2 exsolution does not appear to create significant risks

  18. Molecular basis for the high CO2 adsorption capacity of chabazite zeolites.

    Science.gov (United States)

    Pham, Trong D; Hudson, Matthew R; Brown, Craig M; Lobo, Raul F

    2014-11-01

    CO2 adsorption in Li-, Na-, K-CHA (Si/Al=6,=12), and silica chabazite zeolites was investigated by powder diffraction. Two CO2 adsorption sites were found in all chabazites with CO2 locating in the 8-membered ring (8MR) pore opening being the dominant site. Electric quadrupole-electric field gradient and dispersion interactions drive CO2 adsorption at the middle of the 8 MRs, while CO2 polarization due to interaction with cation sites controls the secondary CO2 site. In Si-CHA, adsorption is dominated by dispersion interactions with CO2 observed on the pore walls and in 8 MRs. CO2 adsorption complexes on dual cation sites were observed on K-CHA, important for K-CHA-6 samples due to a higher probability of two K(+) cations bridging CO2. Trends in isosteric heats of CO2 adsorption based on cation type and concentration can be correlated with adsorption sites and CO2 quantity. A decrease in the hardness of metal cations results in a decrease in the direct interaction of these cations with CO2.

  19. Laser photoacoustic detection of CO2 in old disc tree-rings.

    Science.gov (United States)

    Ageev, Boris; Ponomarev, Yurii; Sapozhnikova, Valeria

    2010-01-01

    A homemade CO2-laser photoacoustic spectrometer has been used for monitoring CO2 in gas samples extracted under vacuum from the wood of old spruce disc tree-rings for a ∼60 year series. The experimental results show that (1) the CO2 concentration exhibits annual trends correlated with an increase in atmospheric CO2 in a number of cases; (2) at the time when the annual CO2 trend changes from positive to negative, the annual tree-ring stable carbon isotope ratios (δ13C) of CO2 change as well; (3) the disc tree-ring widths are observed to decrease in most cases where the annual CO2 increased; (4) simultaneously with the annual CO2 variation, annual H2O distribution was detected in gas samples of the wood tree-rings of one spruce disc. The observed patterns of the annual CO2 distribution in the disc tree-rings are assumed to be the evidence of the impact of the atmospheric CO2 increase. In other words, a change in the concentration gradient between the stem and the atmospheric CO2 may lead to a gradual CO2 accumulation in the stem because of a decrease in the diffusion rate and to a change in the tree parameters.

  20. Spatial distribution of Δ14CO2 across Eurasia: measurements from the TROICA-8 expedition

    Directory of Open Access Journals (Sweden)

    D. J. Mondeel

    2008-08-01

    Full Text Available Because fossil fuel derived CO2 is the only source of atmospheric CO2 that is devoid of 14C, atmospheric measurements of Δ14CO2 can be used to constrain fossil fuel emissions at local and regional scales. However, at the continental scale, atmospheric transport and other sources of variability in Δ14CO2 may influence the fossil fuel detection capability. We present a set of Δ14CO2 observations from the train-based TROICA-8 expedition across Eurasia in March–April 2004. Local perturbations in Δ14CO2 are caused by easily identifiable sources from nuclear reactors and localized pollution events. The remaining data show an increase in Δ14CO2 from Western Russia (40° E to Eastern Siberia (120° E, consistent with depletion in 14CO2 caused by fossil fuel CO2 emissions in heavily populated Europe, and gradual dispersion of the fossil fuel plume across Northern Asia. Other tracer gas species which may be correlated with fossil fuel CO2 emissions, including carbon monoxide, sulphur hexafluoride, and perchloroethylene, were also measured and the results compared with the Δ14CO2 measurements. The sulphur hexafluoride longitudinal gradient is not significant relative to the measurement uncertainty. Carbon monoxide and perchloroethylene show large-scale trends of enriched values in Western Russia and decreasing values in Eastern Siberia, consistent with fossil fuel emissions, but exhibit significant spatial variability, especially near their primary sources in Western Russia. The clean air Δ14CO2 observations are compared with simulated spatial gradients from the TM5 atmospheric transport model. We show that the change in Δ14CO2 across the TROICA transect is due almost entirely to emissions of fossil fuel CO2, but that the magnitude of this Δ14CO2 gradient is relatively insensitive to modest uncertainties in the fossil fuel flux. In contrast, the Δ14CO2 gradient is strongly sensitive to the modeled representation of vertical mixing, suggesting

  1. CO2 Virtual Science Data Environment API

    Data.gov (United States)

    National Aeronautics and Space Administration — The CO2 Virtual Data Environment is a comprehensive effort at bringing together the models, data, and tools necessary to perform research on atmospheric CO2.This...

  2. Why capture CO2 from the atmosphere?

    National Research Council Canada - National Science Library

    Keith, David W

    2009-01-01

    Air capture is an industrial process for capturing CO2 from ambient air; it is one of an emerging set of technologies for CO2 removal that includes geological storage of biotic carbon and the acceleration of geochemical weathering...

  3. Swiss prealpine Rietholzbach research catchment and lysimeter: 32 year time series and 2003 drought event

    NARCIS (Netherlands)

    Seneviratne, S.I.; Lehner, I.; Gurtz, J.; Teuling, A.J.; Lang, H.; Moser, U.; Grebner, D.; Menzel, L.; Schroff, K.; Vitvar, T.; Zappa, M.

    2012-01-01

    The prealpine Rietholzbach research catchment provides long-term continuous hydroclimatological measurements in northeastern Switzerland, including lysimeter evapotranspiration measurements since 1976, and soil moisture measurements since 1994. We analyze here the monthly data record over 32 years (

  4. Effecten van olieverontreinging op de vegetatie van een twaalftal lysimeters te Katwijk

    NARCIS (Netherlands)

    Kemmers, R.H.

    1979-01-01

    Door het Contactcentrum Olie-industrie en Openbare Watervoorziening wordt op een twaalftal lysimeters in de duinen nabij Katwijk onderzoek verricht naar de afbraaksnelheid van olie in de bodem onder invloed van micro-organismen.

  5. Calculating subsurface CO2 storage capacities

    NARCIS (Netherlands)

    Meer, B. van der; Egberts, P.

    2008-01-01

    Often we need to know how much CO2 we can store in a certain underground space, or how much such space we need to store a given amount of CO2. In a recent attempt (Bradshaw et al., 2006) to list various regional and global estimates of CO2 storage capacity (Figure 1), the estimates reported are ofte

  6. Calculating subsurface CO2 storage capacities

    NARCIS (Netherlands)

    Meer, B. van der; Egberts, P.

    2008-01-01

    Often we need to know how much CO2 we can store in a certain underground space, or how much such space we need to store a given amount of CO2. In a recent attempt (Bradshaw et al., 2006) to list various regional and global estimates of CO2 storage capacity (Figure 1), the estimates reported are

  7. Water table effects on measured and simulated fluxes in weighing lysimeters for differently-textured soils

    Directory of Open Access Journals (Sweden)

    Wegehenkel Martin

    2015-03-01

    Full Text Available Weighing lysimeters can be used for studying the soil water balance and to analyse evapotranspiration (ET. However, not clear was the impact of the bottom boundary condition on lysimeter results and soil water movement. The objective was to analyse bottom boundary effects on the soil water balance. This analysis was carried out for lysimeters filled with fine- and coarse-textured soil monoliths by comparing simulated and measured data for lysimeters with a higher and a lower water table. The eight weighable lysimeters had a 1 m2 grass-covered surface and a depth of 1.5 m. The lysimeters contained four intact monoliths extracted from a sandy soil and four from a soil with a silty-clay texture. For two lysimeters of each soil, constant water tables were imposed at 135 cm and 210 cm depths. Evapotranspiration, change in soil water storage, and groundwater recharge were simulated for a 3-year period (1996 to 1998 using the Hydrus-1D software. Input data consisted of measured weather data and crop model-based simulated evaporation and transpiration. Snow cover and heat transport were simulated based on measured soil temperatures. Soil hydraulic parameter sets were estimated (i from soil core data and (ii based on texture data using ROSETTA pedotransfer approach. Simulated and measured outflow rates from the sandy soil matched for both parameter sets. For the sand lysimeters with the higher water table, only fast peak flow events observed on May 4, 1996 were not simulated adequately mainly because of differences between simulated and measured soil water storage caused by ET-induced soil water storage depletion. For the silty-clay soil, the simulations using the soil hydraulic parameters from retention data (i were matching the lysimeter data except for the observed peak flows on May, 4, 1996, which here probably resulted from preferential flow. The higher water table at the lysimeter bottom resulted in higher drainage in comparison with the lysimeters

  8. Superhydrophobic Cones for Continuous Collection and Directional Transportation of CO2 Microbubbles in CO2 Supersaturated Solutions.

    Science.gov (United States)

    Xue, Xiuzhan; Yu, Cunming; Wang, Jingming; Jiang, Lei

    2016-12-27

    Microbubbles are tiny bubbles with diameters below 50 μm. Because of their minute buoyant force, the microbubbles stagnate in aqueous media for a long time, and they sometimes cause serious damage. Most traditional methods chosen for elimination of gas bubbles utilize buoyancy forces including chemical methods and physical methods, and they only have a minor effect on microbubbles. Several approaches have been developed to collect and transport microbubbles in aqueous media. However, the realization of innovative strategies to directly collect and transport microbubbles in aqueous media remains a big challenge. In nature, both spider silk and cactus spines take advantage of their conical-shaped surface to yield the gradient of Laplace pressure and surface free energy for collecting fog droplets from the environment. Inspired by this, we introduce here the gradient of Laplace pressure and surface free energy to the interface of superhydrophobic copper cones (SCCs), which can continuously collect and directionally transport CO2 microbubbles (from tip side to base side) in CO2-supersaturated solution. A gas layer was formed when the microbubbles encounter the SCCs. This offers a channel for microbubble directional transportation. The efficiency of microbubble transport is significantly affected by the apex angle of SCCs and the carbon dioxide concentration. The former provides different gradients of Laplace pressure as the driving force. The latter represents the capacity, which offers the quantity of CO2 microbubbles for collection and transportation. We believe that this approach provides a simple and valid way to remove microbubbles.

  9. CO2 Capture for Cement Technology

    OpenAIRE

    2013-01-01

    Production of cement is an energy intensive process and is the source of considerable CO2emissions. Itis estimated that the cement industry contributes around 8% of total global CO2emissions. CO2is oneof the major greenhouse gases. In the atmosphere, the CO2concentration has increased from 310 ppmvin 1960 to 390 ppmv in 2012, probably due to human activity. A lot of research is being carried out forreducing CO2emissions from large stationary sources. Ofwhich, the carbonate looping process is ...

  10. Forest succession at elevated CO2

    Energy Technology Data Exchange (ETDEWEB)

    Clark, James S.; Schlesinger, William H.

    2002-02-01

    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.

  11. Residual CO2 trapping in Indiana limestone.

    Science.gov (United States)

    El-Maghraby, Rehab M; Blunt, Martin J

    2013-01-01

    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.

  12. Selecting CO2 Sources for CO2 Utilization by Environmental-Merit-Order Curves.

    Science.gov (United States)

    von der Assen, Niklas; Müller, Leonard J; Steingrube, Annette; Voll, Philip; Bardow, André

    2016-02-01

    Capture and utilization of CO2 as alternative carbon feedstock for fuels, chemicals, and materials aims at reducing greenhouse gas emissions and fossil resource use. For capture of CO2, a large variety of CO2 sources exists. Since they emit much more CO2 than the expected demand for CO2 utilization, the environmentally most favorable CO2 sources should be selected. For this purpose, we introduce the environmental-merit-order (EMO) curve to rank CO2 sources according to their environmental impacts over the available CO2 supply. To determine the environmental impacts of CO2 capture, compression and transport, we conducted a comprehensive literature study for the energy demands of CO2 supply, and constructed a database for CO2 sources in Europe. Mapping these CO2 sources reveals that CO2 transport distances are usually small. Thus, neglecting transport in a first step, we find that environmental impacts are minimized by capturing CO2 first from chemical plants and natural gas processing, then from paper mills, power plants, and iron and steel plants. In a second step, we computed regional EMO curves considering transport and country-specific impacts for energy supply. Building upon regional EMO curves, we identify favorable locations for CO2 utilization with lowest environmental impacts of CO2 supply, so-called CO2 oases.

  13. Air-sea CO2 fluxes on the Bering Sea shelf

    Directory of Open Access Journals (Sweden)

    M. A. Jeffries

    2011-05-01

    Full Text Available There have been few previous studies of surface seawater CO2 partial pressure (pCO2 variability and air-sea CO2 gas exchange rates for the Bering Sea shelf. In 2008, spring and summertime observations were collected in the Bering Sea shelf as part of the Bering Sea Ecological Study (BEST. Our results indicate that the Bering Sea shelf was close to neutral in terms of CO2 sink-source status in springtime due to relatively small air-sea CO2 gradients (i.e., ΔpCO2 and sea-ice cover. However, by summertime, very low seawater pCO2 values were observed and much of the Bering Sea shelf became strongly undersaturated with respect to atmospheric CO2 concentrations. Thus the Bering Sea shelf transitions seasonally from mostly neutral conditions to a strong oceanic sink for atmospheric CO2 particularly in the "green belt" region of the Bering Sea where there are high rates of phytoplankton primary production (PPand net community production (NCP. Ocean biological processes dominate the seasonal drawdown of seawater pCO2 for large areas of the Bering Sea shelf, with the effect partly countered by seasonal warming. In small areas of the Bering Sea shelf south of the Pribilof Islands and in the SE Bering Sea, seasonal warming is the dominant influence on seawater pCO2, shifting localized areas of the shelf from minor/neutral CO2 sink status to neutral/minor CO2 source status, in contrast to much of the Bering Sea shelf. Overall, we compute that the Bering Sea shelf CO2 sink in 2008 was 157 ± 35 Tg C yr−1 (Tg = 1012 g C and thus a strong sink for CO2.

  14. Amine scrubbing for CO2 capture.

    Science.gov (United States)

    Rochelle, Gary T

    2009-09-25

    Amine scrubbing has been used to separate carbon dioxide (CO2) from natural gas and hydrogen since 1930. It is a robust technology and is ready to be tested and used on a larger scale for CO2 capture from coal-fired power plants. The minimum work requirement to separate CO2 from coal-fired flue gas and compress CO2 to 150 bar is 0.11 megawatt-hours per metric ton of CO2. Process and solvent improvements should reduce the energy consumption to 0.2 megawatt-hour per ton of CO2. Other advanced technologies will not provide energy-efficient or timely solutions to CO2 emission from conventional coal-fired power plants.

  15. Intra-aggregate CO2 enrichment: a modelling approach for aerobic soils

    Directory of Open Access Journals (Sweden)

    H. Schack-Kirchner

    2012-10-01

    Full Text Available CO2 concentration gradients inside soil aggregates, caused by the respiration of soil microorganisms and fungal hyphae, might lead to variations in the soil solution chemistry on a mm-scale, and to an underestimation of the CO2 storage. But, up to now, there seems to be no feasible method for measuring CO2 inside natural aggregates with sufficient spatial resolution. We combined a one-dimensional model for gas diffusion in the inter-aggregate pore-space with a cylinder diffusion model, simulating the consumption/production and diffusion of O2 and CO2 inside soil aggregates with air- and water-filled pores. Our model predicts that for aerobic respiration (respiratory quotient = 1 the intra-aggregate increase in the CO2 partial pressure can never be higher than 0.9 kPa for siliceous, and 0.08 kPa for calcaric aggregates, independent of the level of water-saturation. This suggests that only for siliceous aggregates CO2 produced by aerobic respiration might cause a high small-scale spatial variability in the soil solution chemistry. In calcaric aggregates, however, the contribution of carbonate species to the CO2 transport should lead to secondary carbonates on the aggregate surfaces. As regards the total CO2 storage in aerobic soils, both siliceous and calcaric, the effect of intra-aggregate CO2 gradients seems to be negligible. To assess the effect of anaerobic respiration on the intra-aggregate CO2 gradients, the development of a device for measuring CO2 on a mm-scale in soils is indispensable.

  16. 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.

  17. Quantifying the "chamber effect" in CO2 flux measurements

    Science.gov (United States)

    Vihermaa, Leena; Childs, Amy; Long, Hazel; Waldron, Susan

    2014-05-01

    The significance of aquatic CO2 emissions has received attention in recent years. For example annual aquatic emissions in the Amazon basin have been estimated as 500 Mt of carbon1. Methods for determining the flux rates include eddy covariance flux tower measurements, flux estimates calculated from partial pressure of CO2 (pCO2) in water and the use floating flux chambers connected to an infra-red gas analyser. The flux chamber method is often used because it is portable, cheaper and allows smaller scale measurements. It is also a direct method and hence avoids problems related to the estimation of the gas transfer coefficient that is required when fluxes are calculated from pCO2. However, the use of a floating chamber may influence the flux measurements obtained. The chamber shields the water underneath from effects of wind which could lead to lower flux estimates. Wind increases the flux rate by i) causing waves which increase the surface area for efflux, and ii) removing CO2 build up above the water surface, hence maintaining a higher concentration gradient. Many floating chambers have an underwater extension of the chamber below the float to ensure better seal to water surface and to prevent any ingress of atmospheric air when waves rock the chamber. This extension may cause additional turbulence in flowing water and hence lead to overestimation of flux rates. Some groups have also used a small fan in the chamber headspace to ensure thorough mixing of air in the chamber. This may create turbulence inside the chamber which could increase the flux rate. Here we present results on the effects of different chamber designs on the detected flux rates. 1Richey et al. 2002. Outgassing from Amazonian rivers and wetlands as a large tropical source of atmospheric CO2. Nature 416: 617-620.

  18. Wellbore integrity analysis of a natural CO2 producer

    KAUST Repository

    Crow, Walter

    2010-03-01

    Long-term integrity of existing wells in a CO2-rich environment is essential for ensuring that geological sequestration of CO2 will be an effective technology for mitigating greenhouse gas-induced climate change. The potential for wellbore leakage depends in part on the quality of the original construction as well as geochemical and geomechanical stresses that occur over its life-cycle. Field data are essential for assessing the integrated effect of these factors and their impact on wellbore integrity, defined as the maintenance of isolation between subsurface intervals. In this report, we investigate a 30-year-old well from a natural CO2 production reservoir using a suite of downhole and laboratory tests to characterize isolation performance. These tests included mineralogical and hydrological characterization of 10 core samples of casing/cement/formation, wireline surveys to evaluate well conditions, fluid samples and an in situ permeability test. We find evidence for CO2 migration in the occurrence of carbonated cement and calculate that the effective permeability of an 11′-region of the wellbore barrier system was between 0.5 and 1 milliDarcy. Despite these observations, we find that the amount of fluid migration along the wellbore was probably small because of several factors: the amount of carbonation decreased with distance from the reservoir, cement permeability was low (0.3-30 microDarcy), the cement-casing and cement-formation interfaces were tight, the casing was not corroded, fluid samples lacked CO2, and the pressure gradient between reservoir and caprock was maintained. We conclude that the barrier system has ultimately performed well over the last 3 decades. These results will be used as part of a broader effort to develop a long-term predictive simulation tool to assess wellbore integrity performance in CO2 storage sites. © 2009 Elsevier Ltd. All rights reserved.

  19. Covalent Organic Frameworks for CO2 Capture.

    Science.gov (United States)

    Zeng, Yongfei; Zou, Ruqiang; Zhao, Yanli

    2016-04-20

    As an emerging class of porous crystalline materials, covalent organic frameworks (COFs) are excellent candidates for various applications. In particular, they can serve as ideal platforms for capturing CO2 to mitigate the dilemma caused by the greenhouse effect. Recent research achievements using COFs for CO2 capture are highlighted. A background overview is provided, consisting of a brief statement on the current CO2 issue, a summary of representative materials utilized for CO2 capture, and an introduction to COFs. Research progresses on: i) experimental CO2 capture using different COFs synthesized based on different covalent bond formations, and ii) computational simulation results of such porous materials on CO2 capture are summarized. Based on these experimental and theoretical studies, careful analyses and discussions in terms of the COF stability, low- and high-pressure CO2 uptake, CO2 selectivity, breakthrough performance, and CO2 capture conditions are provided. Finally, a perspective and conclusion section of COFs for CO2 capture is presented. Recent advancements in the field are highlighted and the strategies and principals involved are discussed.

  20. 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.

  1. Energyless CO2 Absorption, Generation, and Fixation Using Atmospheric CO2.

    Science.gov (United States)

    Inagaki, Fuyuhiko; Okada, Yasuhiko; Matsumoto, Chiaki; Yamada, Masayuki; Nakazawa, Kenta; Mukai, Chisato

    2016-01-01

    From an economic and ecological perspective, the efficient utilization of atmospheric CO2 as a carbon resource should be a much more important goal than reducing CO2 emissions. However, no strategy to harvest CO2 using atmospheric CO2 at room temperature currently exists, which is presumably due to the extremely low concentration of CO2 in ambient air (approximately 400 ppm=0.04 vol%). We discovered that monoethanolamine (MEA) and its derivatives efficiently absorbed atmospheric CO2 without requiring an energy source. We also found that the absorbed CO2 could be easily liberated with acid. Furthermore, a novel CO2 generator enabled us to synthesize a high value-added material (i.e., 2-oxazolidinone derivatives based on the metal catalyzed CO2-fixation at room temperature) from atmospheric CO2.

  2. Different CO2 absorbents-modified SBA-15 sorbent for highly selective CO2 capture

    Science.gov (United States)

    Liu, Xiuwu; Zhai, Xinru; Liu, Dongyang; Sun, Yan

    2017-05-01

    Different CO2 absorbents-modified SBA-15 materials are used as CO2 sorbent to improve the selectivity of CH4/CO2 separation. The SBA-15 sorbents modified by physical CO2 absorbents are very limited to increasing CO2 adsorption and present poor selectivity. However, the SBA-15 sorbents modified by chemical CO2 absorbents increase CO2 adsorption capacity obviously. The separation coefficients of CO2/CH4 increase in this case. The adsorption and regeneration properties of the SBA-15 sorbents modified by TEA, MDEA and DIPA have been compared. The SBA-15 modified by triethanolamine (TEA) presents better CO2/CH4 separation performance than the materials modified by other CO2 absorbents.

  3. Reconsider an element: F budgets for field lysimeters

    Science.gov (United States)

    O'Brien, R.; Keller, K.; April, R. A.; Keller, D.

    2001-12-01

    Chemical budgets of Fluorine (F) can be relatively simple in ecosystems due to the presence of only one anionic form at circumneutral pH values (F-) and relatively few potential sources and/or sinks. In many cases, F may serve as a tracer of primary mineral weathering. We constructed annual water and fluoride budgets for experimental lysimeters ("sandboxes") with 3 different types of plant cover. The sandboxes were constructed in 1982 at the Hubbard Brook Experimental Forest; these systems have identical substrate material and are fully lined to collect all water and solute exports. Aqueous fluoride export from a sandbox covered with moss and lichen was 330 Eq/ha/yr; plant uptake decreased both water and fluoride exports from sandboxes with bunchgrass and pine cover. Microprobe analysis of the sand has identified fluorapatite (Ca5(PO4)3F) as the dominant F-bearing mineral phase. Modal analysis of the sand, coupled with actual mineral formulae, provide an inventory of the existing mass of F in primary minerals. Thus, fluorine budgets for these systems may be useful for estimating weathering rates of fluorapatite as well as release rates and long-term availability of phosphorus to ecosystems.

  4. Numerical modeling of cold magmatic CO2 flux measurements for the exploration of hidden geothermal systems

    Science.gov (United States)

    Peiffer, Loïc.; Wanner, Christoph; Pan, Lehua

    2015-10-01

    The most accepted conceptual model to explain surface degassing of cold magmatic CO2 in volcanic-geothermal systems involves the presence of a gas reservoir. In this study, numerical simulations using the TOUGH2-ECO2N V2.0 package are performed to get quantitative insights into how cold CO2 soil flux measurements are related to reservoir and fluid properties. Although the modeling is based on flux data measured at a specific geothermal site, the Acoculco caldera (Mexico), some general insights have been gained. Both the CO2 fluxes at the surface and the depth at which CO2 exsolves are highly sensitive to the dissolved CO2 content of the deep fluid. If CO2 mainly exsolves above the reservoir within a fracture zone, the surface CO2 fluxes are not sensitive to the reservoir size but depend on the CO2 dissolved content and the rock permeability. For gas exsolution below the top of the reservoir, surface CO2 fluxes also depend on the gas saturation of the deep fluid as well as the reservoir size. The absence of thermal anomalies at the surface is mainly a consequence of the low enthalpy of CO2. The heat carried by CO2 is efficiently cooled down by heat conduction and to a certain extent by isoenthalpic volume expansion depending on the temperature gradient. Thermal anomalies occur at higher CO2 fluxes (>37,000 g m-2 d-1) when the heat flux of the rising CO2 is not balanced anymore. Finally, specific results are obtained for the Acoculco area (reservoir depth, CO2 dissolved content, and gas saturation state).

  5. Field lysimeter studies for performance evaluation of grouted Hanford defense wastes

    Energy Technology Data Exchange (ETDEWEB)

    Last, G.V.; Serne, R.J.; LeGore, V.L.

    1995-02-01

    The Grout Waste Test Facility (GWTF) consisted of four large field lysimeters designed to test the leaching and migration rates of grout-solidified low-level radioactive wastes generated by Hanford Site operations. Each lysimeter was an 8-m-deep by 2-media closed-bottom caisson that was placed in the ground such that the uppermost rim remained just above grade. Two of these lysimeters were used; the other two remained empty. The two lysimeters that were used (A-1 and B-1) were backfilled with a two-layer soil profile representative of the proposed grout disposal site. The proposed grout disposal site (termed the Grout Treatment Facility Landfill) is located immediately east of the Hanford Site`s 200 East Area. This soil profile consisted of a coarse sand into which the grout waste forms were placed and covered by 4 m of a very fine sand. The A-1 lysimeter was backfilled in March 1985, with a grout-solidified phosphate/sulfate liquid waste from N Reactor decontamination and ion exchange resin regeneration. The B-1 lysimeter was backfilled in September 1985 and received a grout-solidified simulated cladding removal waste representative of waste generated from fuel reprocessing operations at the head end of the Plutonium Uranium Extraction (PUREX) plant. Routine monitoring and leachate collection activities were conducted for over three years, terminating in January 1989. Drainage was collected sporadically between January 1989 and December 1992. Decontamination and decommissioning of these lysimeters during the summer of 1994, confirmed the presence of a 15 to 20-cm-long hairline crack in one of the bottom plate welds. This report discusses the design and construction of the GWTF, presents the routine data collected from this facility through January 1989 and subsequent data collected sporadically between 1989 and 1993, and provides a brief discussion concerning preliminary interpretation of the results.

  6. Vertical and horizontal soil CO2 transport and its exchanges with the atmosphere

    Science.gov (United States)

    Sánchez-Cañete, Enrique P.; Serrano-Ortíz, Penélope; Kowalski, Andrew S.; Curiel Yuste, Jorge; Domingo, Francisco; Oyonarte, Cecilio

    2015-04-01

    The CO2 efflux from soils to the atmosphere constitutes one of the major fluxes of the terrestrial carbon cycle and is a key determinant for sources and sinks of CO2 in land-atmosphere exchanges. Because of their large global magnitude, even small changes in soil CO2 effluxes directly affect the atmospheric CO2 content. Despite much research, models of soil CO2 efflux rates are highly uncertain, with the positive or negative feedbacks between underground carbon pools and fluxes and their temperature sensitivities in future climate scenarios largely unknown. Now it is necessary to change the point of view regarding CO2 exchange studies from an inappropriately conceived static system in which all respired CO2 is directly emitted by molecular processes to the atmosphere, to a dynamic system with gas transport by three different processes: convection, advection and molecular diffusion. Here we study the effects of wind-induced advection on the soil CO2 molar fraction during two years in a shrubland plateau situated in the Southeast of Spain. A borehole and two subterranean profiles (vertical and horizontal) were installed to study CO2 transport in the soil. Exchanges with the atmosphere were measured by an eddy covariance tower. In the vertical profile, two CO2 sensors (GMP-343, Vaisala) were installed at 0.15m and 1.5m along with soil temperature and humidity probes. The horizontal profile was designed to measure horizontal movements in the soil CO2 molar fraction due to down-gradient CO2 from the plant, where the majority CO2 is produced, towards bare soil. Three CO2 sensors (GMM-222, Vaisala) were installed, the first below plant (under-plant), the second in bare soil separated 25 cm from the first sensor (near-plant) and the third in bare soil at 25 cm from the second sensor (bare soil). The results show how the wind induces the movement of subterranean air masses both horizontally and vertically, affecting atmospheric CO2 exchanges. The eddy covariance tower

  7. 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.

  8. 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....... The CO2 capture capacity of limestone in the raw meal is lower than for pure limestone. The difference in the CO2 capture capacity decreases with an increase in cycle number. The calcination conditions and composition are major factors that influence the CO2 capture capacity of limestone. At 850 °C in N2...

  9. Responses of soil microbial activity to cadmium pollution and elevated CO2.

    Science.gov (United States)

    Chen, Yi Ping; Liu, Qiang; Liu, Yong Jun; Jia, Feng An; He, Xin Hua

    2014-03-06

    To address the combined effects of cadmium (Cd) and elevated CO2 on soil microbial communities, DGGE (denaturing gradient gel electrophoresis) profiles, respiration, carbon (C) and nitrogen (N) concentrations, loessial soils were exposed to four levels of Cd, i.e., 0 (Cd0), 1.5 (Cd1.5), 3.0 (Cd3.0) and 6.0 (Cd6.0) mg Cd kg(-1) soil, and two levels of CO2, i.e., 360 (aCO2) and 480 (eCO2) ppm. Compared to Cd0, Cd1.5 increased fungal abundance but decreased bacterial abundance under both CO2 levels, whilst Cd3.0 and Cd6.0 decreased both fungal and bacterial abundance. Profiles of DGGE revealed alteration of soil microbial communities under eCO2. Soil respiration decreased with Cd concentrations and was greater under eCO2 than under aCO2. Soil total C and N were greater under higher Cd. These results suggest eCO2 could stimulate, while Cd pollution could restrain microbial reproduction and C decomposition with the restraint effect alleviated by eCO2.

  10. 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.

  11. [A new colorimetric CO2 indicator Colibri].

    Science.gov (United States)

    Nishiyama, T; Hanaoka, K

    1996-06-01

    A new colorimetric carbon dioxide (CO2) indicator Colibri is a disposable, compact and light weighted device. Colibri does not need to be calibrated and is easily usable in an emergency. It indicates blue with CO2 below 4 mmHg and becomes yellow with CO2 above 40 mmHg. In comparison with EASY CAP, Colibri functions for a longer period and it has a humidifier and a bacterial filter. Colibri is useful for emergency situations and anesthetic care.

  12. CO2 capture in different carbon materials.

    Science.gov (United States)

    Jiménez, Vicente; Ramírez-Lucas, Ana; Díaz, José Antonio; Sánchez, Paula; Romero, Amaya

    2012-07-03

    In this work, the CO(2) capture capacity of different types of carbon nanofibers (platelet, fishbone, and ribbon) and amorphous carbon have been measured at 26 °C as at different pressures. The results showed that the more graphitic carbon materials adsorbed less CO(2) than more amorphous materials. Then, the aim was to improve the CO(2) adsorption capacity of the carbon materials by increasing the porosity during the chemical activation process. After chemical activation process, the amorphous carbon and platelet CNFs increased the CO(2) adsorption capacity 1.6 times, whereas fishbone and ribbon CNFs increased their CO(2) adsorption capacity 1.1 and 8.2 times, respectively. This increase of CO(2) adsorption capacity after chemical activation was due to an increase of BET surface area and pore volume in all carbon materials. Finally, the CO(2) adsorption isotherms showed that activated amorphous carbon exhibited the best CO(2) capture capacity with 72.0 wt % of CO(2) at 26 °C and 8 bar.

  13. Synthetic biology for CO2 fixation.

    Science.gov (United States)

    Gong, Fuyu; Cai, Zhen; Li, Yin

    2016-11-01

    Recycling of carbon dioxide (CO2) into fuels and chemicals is a potential approach to reduce CO2 emission and fossil-fuel consumption. Autotrophic microbes can utilize energy from light, hydrogen, or sulfur to assimilate atmospheric CO2 into organic compounds at ambient temperature and pressure. This provides a feasible way for biological production of fuels and chemicals from CO2 under normal conditions. Recently great progress has been made in this research area, and dozens of CO2-derived fuels and chemicals have been reported to be synthesized by autotrophic microbes. This is accompanied by investigations into natural CO2-fixation pathways and the rapid development of new technologies in synthetic biology. This review first summarizes the six natural CO2-fixation pathways reported to date, followed by an overview of recent progress in the design and engineering of CO2-fixation pathways as well as energy supply patterns using the concept and tools of synthetic biology. Finally, we will discuss future prospects in biological fixation of CO2.

  14. CO2 Capture for Cement Technology

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar

    performed recently has focused on CO2capture from fossil fuel-based power plants. Inherently,this process is especially suitablefor cement plants, as CaO used for CO2capture is also a majoringredient for clinker production. Thus, a detailed investigation was carried outto study the applicationof......% of the inlet CO2 was captured by highly deactivated limestone, which had a maximum CO2 capture capacity of 11.5%, with an inlet Ca/C ratio of 13. So, the performance of the carbonator can be defined by the inlet Ca/C ratio, which can be estimated if the maximum capture capacity of limestone is known...

  15. The CO2 tracer clock for the Tropical Tropopause Layer

    Directory of Open Access Journals (Sweden)

    R.-S. Gao

    2007-07-01

    Full Text Available Observations of CO2 were made in the upper troposphere and lower stratosphere in the deep tropics in order to determine the patterns of large-scale vertical transport and age of air in the Tropical Tropopause Layer (TTL. Flights aboard the NASA WB-57F aircraft over Central America and adjacent ocean areas took place in January and February, 2004 (Pre-AURA Validation Experiment, Pre-AVE and 2006 (Costa Rice AVE, CR-AVE, and for the same flight dates of 2006, aboard the Proteus aircraft from the surface to 15 km over Darwin, Australia (Tropical Warm Pool International Cloud Experiment, TWP-ICE. The data demonstrate that the TTL is composed of two layers with distinctive features: (1 the lower TTL, 350–360 K (potential temperature(θ; approximately 12–14 km, is subject to inputs of convective outflows, as indicated by layers of variable CO2 concentrations, with air parcels of zero age distributed throughout the layer; (2 the upper TTL, from θ=~360 K to ~390 K (14–18 km, ascends slowly and ages uniformly, as shown by a linear decline in CO2 mixing ratio tightly correlated with altitude, associated with increasing age. This division is confirmed by ensemble trajectory analysis. The CO2 concentration at the level of 360 K was 380.0(±0.2 ppmv, indistinguishable from surface site values in the Intertropical Convergence Zone (ITCZ for the flight dates. Values declined with altitude to 379.2(±0.2 ppmv at 390 K, implying that air in the upper TTL monotonically ages while ascending. In combination with the winter slope of the CO2 seasonal cycle (+10.8±0.4 ppmv/yr, the vertical gradient of –0.78 (±0.09 ppmv gives a mean age of 26(±3 days for the air at 390 K and a mean ascent rate of 1.5(±0.3 mm s−1. The TTL near 360 K in the Southern Hemisphere over Australia is very close in CO2 composition to the TTL in the Northern Hemisphere over Costa Rica, with strong contrasts emerging at lower altitudes (<360 K. Both Pre-AVE and CR-AVE CO2 observed

  16. The CO2 tracer clock for the Tropical Tropopause Layer

    Directory of Open Access Journals (Sweden)

    R.-S. Gao

    2007-05-01

    Full Text Available Observations of CO2 were made in the upper troposphere and lower stratosphere in the deep tropics in order to determine the patterns of large-scale vertical transport and age of air in the Tropical Tropopause Layer (TTL. Flights aboard the NASA WB-57F aircraft over Central America and adjacent ocean areas took place in January and February, 2004 (Pre-AURA Validation Experiment, Pre-AVE and 2006 (Costa Rice AVE, CR-AVE, and for the same flight dates of 2006, aboard the Proteus aircraft from the surface to 15 km over Darwin, Australia (Tropical Warm Pool International Cloud Experiment , TWP-ICE. The data demonstrate that the TTL is composed of two layers with distinctive features: (1 the lower TTL, 350–360 K (potential temperature (θ; approximately 12–14 km, is subject to inputs of convective outflows, as indicated by layers of variable CO2 concentrations, with air parcels of zero age distributed throughout the layer; (2 the upper TTL, from θ= ~360 K to ~390 K (14–18 km, ascends slowly and ages uniformly, as shown by a linear decline in CO2 mixing ratio tightly correlated with altitude, associated with increasing age. This division is confirmed by ensemble trajectory analysis. The CO2 concentration at the level of 360 K was 380.0(±0.2 ppmv, indistinguishable from surface site values in the Intertropical Convergence Zone (ITCZ for the flight dates. Values declined with altitude to 379.2(±0.2 ppmv at 390 K, implying that air in the upper TTL monotonically ages while ascending. In combination with the winter slope of the CO2 seasonal cycle (+10.8±0.4 ppmv/yr, the vertical gradient of 0.78 (±0.09 ppmv gives a mean age of 26(±3 days for the air at 390 K and a mean ascent rate of 1.5(±0.3 mm s−1. The TTL near 360 K in the Southern Hemisphere over Australia is very close in CO2 composition to the TTL in the Northern Hemisphere over Costa Rica, with strong contrasts emerging at lower altitudes (<360 K. Both Pre-AVE and CR-AVE CO2 observed

  17. 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...

  18. CO2 Interaction with Geomaterials (Invited)

    Science.gov (United States)

    Romanov, V.; Howard, B. H.; Lynn, R. J.; Warzinski, R. P.; Hur, T.; Myshakin, E. M.; Lopano, C. L.; Voora, V. K.; Al-Saidi, W. A.; Jordan, K. D.; Cygan, R. T.; Guthrie, G. D.

    2010-12-01

    This work compares the sorption and swelling processes associated with CO2-coal and CO2-clay interactions. We investigated the mechanisms of interaction related to CO2 adsortion in micropores, intercalation into sub-micropores, dissolution in solid matrix, the role of water, and the associated changes in reservoir permeability, for applications in CO2 sequestration and enhanced coal bed methane recovery. The structural changes caused by CO2 have been investigated. A high-pressure micro-dilatometer was equipped to investigate the effect of CO2 pressure on the thermoplastic properties of coal. Using an identical dilatometer, Rashid Khan (1985) performed experiments with CO2 that revealed a dramatic reduction in the softening temperature of coal when exposed to high-pressure CO2. A set of experiments was designed for -20+45-mesh samples of Argonne Premium Pocahontas #3 coal, which is similar in proximate and ultimate analysis to the Lower Kittanning seam coal that Khan used in his experiments. No dramatic decrease in coal softening temperature has been observed in high-pressure CO2 that would corroborate the prior work of Khan. Thus, conventional polymer (or “geopolymer”) theories may not be directly applicable to CO2 interaction with coals. Clays are similar to coals in that they represent abundant geomaterials with well-developed microporous structure. We evaluated the CO2 sequestration potential of clays relative to coals and investigated the factors that affect the sorption capacity, rates, and permanence of CO2 trapping. For the geomaterials comparison studies, we used source clay samples from The Clay Minerals Society. Preliminary results showed that expandable clays have CO2 sorption capacities comparable to those of coal. We analyzed sorption isotherms, XRD, DRIFTS (infrared reflectance spectra at non-ambient conditions), and TGA-MS (thermal gravimetric analysis) data to compare the effects of various factors on CO2 trapping. In montmorillonite, CO2

  19. Soil-atmosphere and vadose zone water fluxes at the Wagna - lysimeter: Workflow, models, and results

    Science.gov (United States)

    Fank, Johann

    2014-05-01

    A precise knowledge of the water fluxes between the soil-plant system and the atmosphere is of great importance for understanding and modeling water, solute and energy transfer in the soil-plant-atmosphere system. Weighing lysimeters are precise tools to allow the determination of the hydrological cycle components in very short time intervals. Lysimeters with controlled suction at the lower boundary allow estimation of capillary rise and deep water percolation on short time scales. Evapotranspiration, rainfall, and irrigation can be computed from weight changes. In the last decades resolution and precision of the weighing systems have been substantially improved, so that modern lysimeters, resting on weighing cells can reach resolutions of up to 0.01 mm. Nevertheless, a lot of external effects (e.g. from maintenance, surface treatment) and small mechanical disturbances (e.g. caused by wind) became visible in the data. Seepage mass data are affected by water sampling and the emptying process of the seepage water container. Increasing parts of corrected seepage mass data show deep water percolation, decreasing parts in dry weather periods can be interpreted as capillary rise. In the evaluation process of corrected lysimeter mass data every increase in system weight (lysimeter mass + cumulative seepage mass) might be interpreted as rainfall or irrigation, whereas every decrease in system weight is interpreted as evapotranspiration. To apply this concept correctly, the noise in both data sets has to be separated from signals using a filtering routine (e.g. Peters et al., 2013) which is appropriate for any event, including events with low disturbances as well as strong wind and heavy precipitation in small time intervals. Based on the data set from the "Wagna" lysimeter in Austria with a high resolution of the scale (~ 0,015 mm) and very low noise due to low wind velocities for the year 2010 a lysimeter data preparation workflow will be executed: (a) correction of the

  20. High-resolution estimation of the water balance components from high-precision lysimeters

    Directory of Open Access Journals (Sweden)

    M. Hannes

    2015-01-01

    Full Text Available Lysimeters offer the opportunity to determine precipitation, evapotranspiration and groundwater-recharge with high accuracy. In contrast to other techniques, like Eddy-flux systems or evaporation pans, lysimeters provide a direct measurement of evapotranspiration from a clearly defined surface area at the scale of a soil profile via the built-in weighing system. In particular the estimation of precipitation can benefit from the much higher surface area compared to typical raingauge systems. Nevertheless, lysimeters are exposed to several external influences that could falsify the calculated fluxes. Therefore, the estimation of the relevant fluxes requires an appropriate data processing with respect to various error sources. Most lysimeter studies account for noise in the data by averaging. However, the effects of smoothing by averaging on the accuracy of the estimated water balance is rarely investigated. In this study, we present a filtering scheme, which is designed to deal with the various kinds of possible errors. We analyze the influence of averaging times and thresholds on the calculated water balance. We further investigate the ability of two adaptive filtering methods (the Adaptive Window and Adaptive Threshold filter (AWAT-filter (Peters et al., 2014 and the consecutively described synchro-filter in further reducing the filtering error. On the basis of the data sets of 18 simultanously running lysimeters of the TERENO SoilCan research site in Bad Lauchstädt, we show that the estimation of the water balance with high temporal resolution and good accuracy is possible.

  1. 4D GPR Experiments--Towards the Virtual Lysimeter

    Science.gov (United States)

    Grasmueck, M.; Viggiano, D. A.; Day-Lewis, F. D.; Drasdis, J. B.; Kruse, S. E.; Or, D.

    2006-05-01

    In-situ monitoring of infiltration, water flow and retention in the vadose zone currently rely primarily on invasive methods, which irreversibly disturb original soil structure and alter its hydrologic behavior in the vicinity of the measurement. For example, use of lysimeters requires extraction and repacking of soil samples, and time- domain reflectometry (TDR) requires insertion of probes into the soil profile. This study investigates the use of repeated high-density 3D ground penetrating radar surveys (also known as 4D GPR) as a non-invasive alternative for detailed visualization and quantification of water flow in the vadose zone. Evaluation of the 4D GPR method was based on a series of controlled point-source water injection experiments into undisturbed beach sand deposits at Crandon Park in Miami, Florida. The goal of the GPR surveys was to image the shape and evolution of a wet-bulb as it propagates from the injection points (~0.5 m) towards the water table at 2.2 m depth. The experimental design was guided by predictive modeling using Hydrus 2D and finite-difference GPR waveform codes. Input parameters for the modeling were derived from hydrologic and electromagnetic characterization of representative sand samples. Guided by modeling results, we injected 30 to 40 liters of tap water through plastic-cased boreholes with slotted bottom sections (0.1 m) located 0.4 to 0.6 m below the surface. During and after injection, an area of 25 m2 was surveyed every 20 minutes using 250 and 500 MHz antennas with a grid spacing of 0.05 x 0.025 m. A total of 20 3D GPR surveys were completed over 3 infiltration sites. To confirm wet-bulb shapes measured by GPR, we injected 2 liters of "brilliant blue" dye (~100 mg/l) along with a saline water tracer towards the end of one experiment. After completion of GPR scanning, a trench was excavated to examine the distribution of the saltwater and dye using TDR and visual inspection, respectively. Preliminary analysis of the 4D GPR

  2. The Idea of Global CO2 Trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    1998-01-01

    The US has been criticized for wanting to earn a fortune on a global CO2 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 CO2 market may provide the world with an epoch-making means of cost-effective co...

  3. Monitoring Options for CO2 Storage

    NARCIS (Netherlands)

    Arts, R.; Winthaegen, P.

    2005-01-01

    This chapter provides an overview of various monitoring techniques for CO2 storage that is structured into three categories-instrumentation in a well (monitoring well); instrumentation at the (near) surface (surface geophysical methods); and sampling at the (near) surface measuring CO2 concentration

  4. CO2 capture research in the Netherlands

    NARCIS (Netherlands)

    Meerman, J.C.; Kuramochi, T.; Egmond, S. van

    2008-01-01

    The global climate is changing due to human activities. This human‑induced climate change is mainly caused by global emissions of carbon dioxide (CO2) into the atmosphere. Most scientists agree that in order to mitigate climate change, by 2050, global CO2 emissions must be reduced by at least 50% co

  5. Photocatalytic CO2 Activation by Water

    NARCIS (Netherlands)

    Yang, Chieh-Chao

    2011-01-01

    Photocatalytic activation of CO2 and water has potential for producing fuels by conversion of photon energy. However, the low productivity still limits practical application. In this study, the goal was to gain more fundamental insight in CO2 activation, and to provide guidelines for rational design

  6. 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.

  7. Capturing CO2 via reactions in nanopores.

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Kevin; Nenoff, Tina Maria; Criscenti, Louise Jacqueline; Tang, Z; Dong, J. H.

    2008-10-01

    This one-year exploratory LDRD aims to provide fundamental understanding of the mechanism of CO2 scrubbing platforms that will reduce green house gas emission and mitigate the effect of climate change. The project builds on the team members expertise developed in previous LDRD projects to study the capture or preferential retention of CO2 in nanoporous membranes and on metal oxide surfaces. We apply Density Functional Theory and ab initio molecular dynamics techniques to model the binding of CO2 on MgO and CaO (100) surfaces and inside water-filled, amine group functionalized silica nanopores. The results elucidate the mechanisms of CO2 trapping and clarify some confusion in the literature. Our work identifies key future calculations that will have the greatest impact on CO2 capture technologies, and provides guidance to science-based design of platforms that can separate the green house gas CO2 from power plant exhaust or even from the atmosphere. Experimentally, we modify commercial MFI zeolite membranes and find that they preferentially transmit H2 over CO2 by a factor of 34. Since zeolite has potential catalytic capability to crack hydrocarbons into CO2 and H2, this finding paves the way for zeolite membranes that can convert biofuel into H2 and separate the products all in one step.

  8. CO2 Rekentool voor Tuinbouw: Handleiding

    NARCIS (Netherlands)

    Hiller, S.R.C.H.; Danse, M.G.

    2009-01-01

    Dit document is een handleiding bij de online CO2 Rekentool voor Tuinbouw Ketens. De CO2 tool is mogelijk gemaakt door de financiële bijdrage van Productschap Tuinbouw en het Ministerie van Landbouw, Natuur en Voedselkwaliteit (LNV). De tool is ontwikkeld door het onderzoeksconsortium WUR, BMA en AI

  9. CO2 capture, transport, storage and utilisation

    NARCIS (Netherlands)

    Brouwer, J.H.

    2013-01-01

    Reducing CO2 emissions requires an integrated CO2 management approach. The dependency between the different industry sectors is higher than commonly acknowledged and covers all areas; capture, transport, storage and utilisation. TNO is one of Europe’s largest independent research organisations and p

  10. Improved Criteria for Increasing CO2 Storage Potential with CO2 Enhanced Oil Recovery

    Science.gov (United States)

    Bauman, J.; Pawar, R.

    2013-12-01

    In recent years it has been found that deployment of CO2 capture and storage technology at large scales will be difficult without significant incentives. One of the technologies that has been a focus in recent years is CO2 enhanced oil/gas recovery, where additional hydrocarbon recovery provides an economic incentive for deployment. The way CO2 EOR is currently deployed, maximization of additional oil production does not necessarily lead to maximization of stored CO2, though significant amounts of CO2 are stored regardless of the objective. To determine the potential of large-scale CO2 storage through CO2 EOR, it is necessary to determine the feasibility of deploying this technology over a wide range of oil/gas field characteristics. In addition it is also necessary to accurately estimate the ultimate CO2 storage potential and develop approaches that optimize oil recovery along with long-term CO2 storage. This study uses compositional reservoir simulations to further develop technical screening criteria that not only improve oil recovery, but maximize CO2 storage during enhanced oil recovery operations. Minimum miscibility pressure, maximum oil/ CO2 contact without the need of significant waterflooding, and CO2 breakthrough prevention are a few key parameters specific to the technical aspects of CO2 enhanced oil recovery that maximize CO2 storage. We have developed reduced order models based on simulation results to determine the ultimate oil recovery and CO2 storage potential in these formations. Our goal is to develop and demonstrate a methodology that can be used to determine feasibility and long-term CO2 storage potential of CO2 EOR technology.

  11. Geophysical monitoring technology for CO2 sequestration

    Science.gov (United States)

    Ma, Jin-Feng; Li, Lin; Wang, Hao-Fan; Tan, Ming-You; Cui, Shi-Ling; Zhang, Yun-Yin; Qu, Zhi-Peng; Jia, Ling-Yun; Zhang, Shu-Hai

    2016-06-01

    Geophysical techniques play key roles in the measuring, monitoring, and verifying the safety of CO2 sequestration and in identifying the efficiency of CO2-enhanced oil recovery. Although geophysical monitoring techniques for CO2 sequestration have grown out of conventional oil and gas geophysical exploration techniques, it takes a long time to conduct geophysical monitoring, and there are many barriers and challenges. In this paper, with the initial objective of performing CO2 sequestration, we studied the geophysical tasks associated with evaluating geological storage sites and monitoring CO2 sequestration. Based on our review of the scope of geophysical monitoring techniques and our experience in domestic and international carbon capture and sequestration projects, we analyzed the inherent difficulties and our experiences in geophysical monitoring techniques, especially, with respect to 4D seismic acquisition, processing, and interpretation.

  12. Tracing the CO2 source and migration in natural analogues from different geological contexts

    Science.gov (United States)

    Battani, A.; Jean Luc, F.; Philippe, S.; Nadine, E.; Olivier, V.; Elodie, J.

    2009-12-01

    Naturally occurring CO2 fields allow studying long-term fluid-rock interactions, and the processes of CO2 migration, useful for the prediction of CO2 behavior in industrial storage sites. Two different provinces showing both leaking systems (hydrothermal areas) and well confined systems (stable sedimentary basins) have been studied. The first province concerns the French CO2 province of Massif Central (volcanic events, seismic activity, high geothermal gradient) and the stable Valence basin. The other study was devoted to the Basin and Range province, USA, with hydrothermal, high seismic and volcanic activity, a high geothermal gradient (Soda Springs; Idaho, Sevier basin), and the non-hydrothermal stable area of the Colorado plateau (Green River, San Rafael anticline and Springerville). The aim is to link the CO2 sources and its subsurface migration to the geological context. In hydrothermal areas, the mesured helium isotopic ratio (R/Ra) is high (close to the mantle ratio), while the CO2/3He ratios move dramatically towards crustal values. In this context, isotopic and elemental noble gas data show that the gas migrates very fast from depth. In more confined areas (natural CO2 fields), the CO2 shows a more important proportion of radiogenic gases (4He) (crustal helium isotopic ratios) and the associated CO2/3He ratios are in the MORB range, or “mantle derived”. We try to explain the apparent discrepancy between the CO2/3He and the R/Ra values in both areas. As a primary assumption, the source of CO2 could be localized in the extensional zones of high geothermal gradient with important seismicity. We suggest that the pseudotachylites formed by frictional melting associated with each seismic event supply an instantaneous crustal CO2.amount to the initial magmatic CO2. This justifies the coeval increase of the CO2/3He ratios without any significant modification in the helium isotopic ratios (instantaneous, no time for 4He production). Moreover, the contact

  13. 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.

  14. An inverse analysis reveals limitations of the soil-CO2 profile method to calculate CO2 production and efflux for well-structured soils

    Directory of Open Access Journals (Sweden)

    M. D. Corre

    2010-08-01

    exchange fluxes across water-filled pores causes the soil-CO2 profile method to fail. These fluxes are driven by the different diffusivities in inter- vs. intra-aggregate pores which create permanent CO2 gradients if separated by a "diffusive water barrier". These results corroborate other studies which have shown that the theory to treat gas diffusion as homogeneous process, a precondition for use of the soil-CO2 profile method, is inaccurate for pore networks which exhibit spatial separation between CO2 production and diffusion out of the soil.

  15. Effect of rice husk gasification residue application on herbicide behavior in micro paddy lysimeter.

    Science.gov (United States)

    Ok, Junghun; Pisith, Sok; Watanabe, Hirozumi; Thuyet, Dang Quoc; Boulange, Julien; Takagi, Kazuhiro

    2015-06-01

    Effects of rice husk gasification residues (RHGR) application on the fate of herbicides, butachlor and pyrazosulfuron-ethyl, in paddy water were investigated using micro paddy lysimeters (MPLs). The dissipation of both herbicides in paddy water was faster in the RHGR treated MPL than in the control MPL. The average concentrations of butachlor and pyrazosulfuron-ethyl in paddy water in the lysimeter treated with RHGR during 21 days were significantly reduced by 51% and 48%, respectively, as compared to those in the lysimeter without RHGR application. The half-lives (DT50) of butachlor in paddy water for control and treatment were 3.1 and 2.3 days respectively, and these values of pyrazosulfuron-ethyl were 3.0 and 2.2 days, respectively. Based on this study, RHGR application in rice paddy environment is an alternative method to reduce the concentration of herbicide in paddy field water and consequently to reduce potential pollution to aquatic environment.

  16. Fungal Community Responses to Past and Future Atmospheric CO2 Differ by Soil Type

    Science.gov (United States)

    Ellis, J. Christopher; Fay, Philip A.; Polley, H. Wayne; Jackson, Robert B.

    2014-01-01

    Soils sequester and release substantial atmospheric carbon, but the contribution of fungal communities to soil carbon balance under rising CO2 is not well understood. Soil properties likely mediate these fungal responses but are rarely explored in CO2 experiments. We studied soil fungal communities in a grassland ecosystem exposed to a preindustrial-to-future CO2 gradient (250 to 500 ppm) in a black clay soil and a sandy loam soil. Sanger sequencing and pyrosequencing of the rRNA gene cluster revealed that fungal community composition and its response to CO2 differed significantly between soils. Fungal species richness and relative abundance of Chytridiomycota (chytrids) increased linearly with CO2 in the black clay (P 0.7), whereas the relative abundance of Glomeromycota (arbuscular mycorrhizal fungi) increased linearly with elevated CO2 in the sandy loam (P = 0.02, R2 = 0.63). Across both soils, decomposition rate was positively correlated with chytrid relative abundance (r = 0.57) and, in the black clay soil, fungal species richness. Decomposition rate was more strongly correlated with microbial biomass (r = 0.88) than with fungal variables. Increased labile carbon availability with elevated CO2 may explain the greater fungal species richness and Chytridiomycota abundance in the black clay soil, whereas increased phosphorus limitation may explain the increase in Glomeromycota at elevated CO2 in the sandy loam. Our results demonstrate that soil type plays a key role in soil fungal responses to rising atmospheric CO2. PMID:25239904

  17. Mechanisms for synoptic transport of atmospheric CO2 in the midlatitudes and tropics

    Directory of Open Access Journals (Sweden)

    R. Lokupitiya

    2008-06-01

    Full Text Available Synoptic variations of CO2 mixing ratio produced by interactions between weather and surface fluxes are investigated mechanistically and quantitatively in midlatitude and tropical regions using continuous in-situ CO2 observations in North America, South America and Europe and forward chemical transport model simulations with the Parameterized Chemistry Transport Model. Frontal CO2 climatologies show consistently strong, characteristic frontal CO2 signals throughout the midlatitudes of North America and Europe. Transitions between synoptically identifiable CO2 air masses or transient spikes along the frontal boundary typically characterize these signals. One case study of a summer cold front shows that CO2 gradients organize with deformational flow along weather fronts producing strong and spatially coherent variations. A boundary layer budget equation is constructed in order to determine contributions to boundary layer CO2 tendencies by horizontal and vertical advection, moist convection, and biological and anthropogenic surface fluxes. Analysis of this equation suggests that, in midlatitudes, advection is responsible for 50–90% of the amplitude of frontal variations in the summer, depending on upstream influences, and 50% of all day-to-day variations throughout the year. Simulations testing sensitivity to local cloud and surface fluxes further suggest that horizontal advection is a major source of CO2 variability in midlatitudes. In the tropics, coupling between convective transport and surface CO2 flux is most important. Due to the scarcity of tropical observations available at the time of this study, future work should extend such mechanistic analysis to additional tropical locations.

  18. A Method for Measuring Subcanopy CO2 Advection

    Science.gov (United States)

    Staebler, R. M.; Fitzjarrald, D. R.

    2004-12-01

    Underestimation of nocturnal CO2 respiration under calm conditions remains an unsolved problem at many forest flux stations, and several groups are currently investigating the direct measurement of horizontal advection of CO2. This presentation will describe a systematic, relatively low-cost methodology developed to determine whether horizontal mean transport of CO2 accounts for the missing CO2 at the Harvard Forest (Petersham, MA). This methodology includes the characterization of subcanopy motions, determining the appropriate size of the subcanopy network required to make the measurements, developing a method of integrating the measurements in the vertical, and determining the required averaging time. Measurements were conducted over 4 years and produced data for 310 nights covering all seasons. Subcanopy flows were decoupled from the flows aloft 75% of the time. Conditions conducive to the generation of negative buoyancy near the forest floor, necessary for drainage flows to develop, were given in 92% of all nights. The occurrence of nocturnal drainage flows correlated well with "missing flux" problems ("deficit nights"), prompting us to propose an improvement on the commonly used friction velocity criterion (which requires u* to be larger than some empirical cut-off for the eddy fluxes to be considered credible). The "negative buoyancy forcing fraction", i.e. negative buoyancy as a fraction of the sum of the dynamic driving forces, can be shown to predict deficit nights significantly better than the u* cut-off. The appropriate horizontal size of the network of wind and CO2 sensors at the Harvard Forest was shown to be on the order of 100 m, ensuring that sensors were generally observing coherent processes on this scale or larger and thus displaying some correlation. Horizontal transport of CO2 was found to be restricted to the bottom ~10 m of the forest, facilitating the development of a method of integrating the horizontal CO2 gradients in the vertical

  19. CO2 deserts: implications of existing CO2 supply limitations for carbon management.

    Science.gov (United States)

    Middleton, Richard S; Clarens, Andres F; Liu, Xiaowei; Bielicki, Jeffrey M; Levine, Jonathan S

    2014-10-01

    Efforts to mitigate the impacts of climate change will require deep reductions in anthropogenic CO2 emissions on the scale of gigatonnes per year. CO2 capture and utilization and/or storage technologies are a class of approaches that can substantially reduce CO2 emissions. Even though examples of this approach, such as CO2-enhanced oil recovery, are already being practiced on a scale >0.05 Gt/year, little attention has been focused on the supply of CO2 for these projects. Here, facility-scale data newly collected by the U.S. Environmental Protection Agency was processed to produce the first comprehensive map of CO2 sources from industrial sectors currently supplying CO2 in the United States. Collectively these sources produce 0.16 Gt/year, but the data reveal the presence of large areas without access to CO2 at an industrially relevant scale (>25 kt/year). Even though some facilities with the capability to capture CO2 are not doing so and in some regions pipeline networks are being built to link CO2 sources and sinks, much of the country exists in "CO2 deserts". A life cycle analysis of the sources reveals that the predominant source of CO2, dedicated wells, has the largest carbon footprint further confounding prospects for rational carbon management strategies.

  20. 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.

  1. Effects of CO2 leakage on soil bacterial communities from simulated CO2-EOR areas.

    Science.gov (United States)

    Chen, Fu; Yang, Yongjun; Ma, Yanjun; Hou, Huping; Zhang, Shaoliang; Ma, Jing

    2016-05-18

    CO2-EOR (enhanced oil recovery) has been proposed as a viable option for flooding oil and reducing anthropogenic CO2 contribution to the atmospheric pool. However, the potential risk of CO2 leakage from the process poses a threat to the ecological system. High-throughput sequencing was used to investigate the effects of CO2 emission on the composition and structure of soil bacterial communities. The diversity of bacterial communities notably decreased with increasing CO2 flux. The composition of bacterial communities varied along the CO2 flux, with increasing CO2 flux accompanied by increases in the relative abundance of Bacteroidetes and Firmicutes phyla, but decreases in the relative abundance of Acidobacteria and Chloroflexi phyla. Within the Firmicutes phylum, the genus Lactobacillus increased sharply when the CO2 flux was at its highest point. Alpha and beta diversity analysis revealed that differences in bacterial communities were best explained by CO2 flux. The redundancy analysis (RDA) revealed that differences in bacterial communities were best explained by soil pH values which related to CO2 flux. These results could be useful for evaluating the risk of potential CO2 leakages on the ecosystems associated with CO2-EOR processes.

  2. Reduced Southern Hemispheric circulation response to quadrupled CO2 due to stratospheric ozone feedback

    Science.gov (United States)

    Chiodo, Gabriel; Polvani, Lorenzo M.

    2017-01-01

    Due to computational constraints, interactive stratospheric ozone chemistry is commonly neglected in most climate models participating in intercomparison projects. The impact of this simplification on the modeled response to external forcings remains unexplored. In this work, we examine the importance of including interactive stratospheric ozone chemistry on the Southern Hemispheric circulation response to an abrupt quadrupling of CO2. We find that including interactive ozone significantly reduces (by 20%) the response of the midlatitude jet to CO2, even though it does not alter the surface temperature response. The reduction of the tropospheric circulation response is due to CO2 induced ozone changes and their effects on the meridional temperature gradient near the tropopause. Our findings suggest that neglecting this stratospheric ozone feedback results in an overestimate of the circulation response to increased CO2. This has important implications for climate projections of the Southern Hemispheric circulation response to CO2.

  3. Glacial CO2 Cycles: A Composite Scenario

    Science.gov (United States)

    Broecker, W. S.

    2015-12-01

    There are three main contributors to the glacial drawdown of atmospheric CO2 content: starvation of the supply of carbon to the ocean-atmosphere reservoir, excess CO2 storage in the deep sea, and surface-ocean cooling. In this talk, I explore a scenario in which all three play significant roles. Key to this scenario is the assumption that deep ocean storage is related to the extent of nutrient stratification of the deep Atlantic. The stronger this stratification, the larger the storage of respiration CO2. Further, it is my contention that the link between Milankovitch insolation cycles and climate is reorganizations of the ocean's thermohaline circulation leading to changes in the deep ocean's CO2 storage. If this is the case, the deep Atlantic d13C record kept in benthic foraminifera shells tells us that deep ocean CO2 storage follows Northern Hemisphere summer insolation cycles and thus lacks the downward ramp so prominent in the records of sea level, benthic 18O and CO2. Rather, the ramp is created by the damping of planetary CO2 emissions during glacial time intervals. As it is premature to present a specific scenario, I provide an example as to how these three contributors might be combined. As their magnitudes and shapes remain largely unconstrained, the intent of this exercise is to provoke creative thinking.

  4. Elevated CO2 and Soil Nitrogen Cycling

    Science.gov (United States)

    Hofmockel, K.; Schlesinger, W.

    2002-12-01

    Although forests can be large terrestrial carbon sinks, soil fertility can limit carbon sequestration in response to increased atmospheric CO2. During five years of CO2 fertilization (ambient + 200ppm) at the Duke Free-Air CO2 Enrichment (FACE) site, net primary production increased significantly by an average of 25% in treatment plots. Total nitrogen in the foliar canopy increased by 16%, requiring an additional 1.3 g N m-2yr-1 to be taken up from soils under elevated CO2. Mechanisms supporting increased nitrogen acquisition have not been identified. Here we report on biological N-fixation rates, using the acetylene reduction assay, in litter and mineral soil during three years of the CO2 enrichment experiment. Lack of a significant CO2 treatment effect on acetylene reduction indicates that carbon is not directly limiting biological N fixation. Nutrient addition experiments using a complete block design with glucose, Fe, Mo and P indicate biological N fixation is co-limited by molybdenum and carbon. These results suggest even if elevated atmospheric CO2 enhances below-ground carbon availability via root exudation, biological nitrogen fixation may not be stimulated due to micronutrient limitations. Assessment of future carbon sequestration by forest stands must consider limitations imposed by site fertility, including micronutrients.

  5. The influence of the lysimeter filling on the soil monolith inside

    Science.gov (United States)

    Puetz, T.; Schilling, J.; Vereecken, H.

    2009-04-01

    In general, lysimeters are vessels containing disturbed or undisturbed soil blocks, for the most realistic scenario with regard to real outdoor conditions an undisturbed soil block so called soil monolith is preferable. The lower boundary condition was realized in two different ways: as a zero-tension lysimeter with a perforated bottom plate or as controlled lower boundary condition with a suction plate. The optimal surface area and the lysimeter length depend mainly on the scientific question. For cropped lysimeter experiments the lysimeter length has to reflect to a maximum root length. The base area is strongly connected to the scale of observation, whereby small-scale heterogeneity will be averaged using large base areas. For our experiments lysimeters with 2.5 m length, 2 m2 base area and with a wall thickness of the round vessel of 10 mm were used. A base frame weighted down by 120 t of concrete weights is necessary to press a lysimeter cylinder into the ground by the aid of a hydraulic press. The hydraulic press is connected with the base frame via chains. Because of the control of the four hydraulic cylinders a very precise vertical pressing process is guaranteed. To visualize the impact of the lysimeter filling on the intactness of the soil monolith a finite element computation was conducted. The finite element package ANSYS Release 11 was used to execute a nonlinear static analysis on a 2D-axisymmetric finite element model, to simulate the pressing process starting from a soil initial stress state and ending with the full length of the vessel driven into the soil, after which the hydraulic press and the concrete weights are deactivated and the vessel-surrounding soil is excavated. The numerical model of the pressing process considers among other things, a cap non-associative plasticity model with shear and volumetric hardening, soil to soil contact with cohesive zone modelling, soil to vessel contact with high friction, soil excavation using element birth

  6. Modelling the water balance of a precise weighable lysimeter for short time scales

    Science.gov (United States)

    Fank, Johann; Klammler, Gernot; Rock, Gerhard

    2015-04-01

    Precise knowledge of the water fluxes between the atmosphere and the soil-plant system and the percolation to the groundwater system is of great importance for understanding and modeling water, solute and energy transfer in the atmosphere-plant-soil-groundwater system. Weighable lysimeters yield the most precise and realistic measures for the change of stored water volume (ΔS), Precipitation (P) which can be rain, irrigation, snow and dewfall and evapotranspiration (ET) as the sum of soil evaporation, evaporation of intercepted water and transpiration. They avoid systematic errors of standard gauges and class-A pans. Lysimeters with controlled suction at the lower boundary allow estimation of capillary rise (C) and leachate (L) on short time scales. Precise weighable large scale (surface >= 1 m2) monolithic lysimeters avoiding oasis effects allow to solve the water balance equation (P - ET - L + C ± ΔS = 0) for a 3D-section of a natural atmosphere-plant-soil-system for a certain time period. Precision and accuracy of the lysimeter measurements depend not only on the precision of the weighing device but also on external conditions, which cannot be controlled or turned off. To separate the noise in measured data sets from signals the adaptive window and adaptive threshold (AWAT) filter (Peters et al., 2014) is used. The data set for the years 2010 and 2011 from the HYDRO-lysimeter (surface = 1 m2, depth = 1 m) in Wagna, Austria (Klammler and Fank, 2014) with a resolution of 0,01 mm for the lysimeter scale and of 0,001 mm for the leachate tank scale is used to evaluate the water balance. The mass of the lysimeter and the mass of the leachate tank is measured every two seconds. The measurements are stored as one minute arithmetic means. Based on calculations in a calibration period from January to May 2010 with different widths of moving window the wmax - Parameter for the AWAT filter was set to 41 minutes. A time series for the system mass ('upper boundary') of the

  7. CO2 laser in vitreoretinal surgery

    Energy Technology Data Exchange (ETDEWEB)

    Karlin, D.B.; Patel, C.K.; Wood, O.R.; Llovera, I.

    1980-01-01

    Radiation from a CO2 laser has the dual effect of phototransection and photocoagulation. Incisions have been made in scleral-chorioretinal tissue, lens tissue, and the vitreous body (with and without membrane formation). Results indicate that the CO2 laser may be useful in intravitreal surgery. Its simultaneous cutting and coagulating properties may make the experimental transvitreal chorioretinal biopsy and the full-thickness ocular wall resection for small melanosarcomas of the choroid clinical possibilities in the not too distant future. Finally, the effects of CO2 laser radiation on the normal human lens suggests the possibility of the dissolution of cataracts by laser irradiation.

  8. Spin polarization effect for Co2 molecule

    Institute of Scientific and Technical Information of China (English)

    Yan Shi-Ying; Bao Wen-Sheng

    2007-01-01

    The density functional theory (DFT)(b3p86) of Gaussian 03 has been used to optimize the structure of the Co2molecule, a transition metal element molecule. The result shows that the ground state for the Co2 molecule is a 7-multiple state, indicating a spin polarization effect in the Co2 molecule. Meanwhile, we have not found any spin pollution because the wavefunction of the ground state is not mingled with wavefunctions of higher-energy states. So for the ground state of Co2 molecule to be a 7-multiple state is the indicative of spin polarization effect of the Co2molecule, that is, there exist 6 parallel spin electrons in a Co2 molecule. The number of non-conjugated electrons is the greatest. These electrons occupy different spacial orbitals so that the energy of the Co2 molecule is minimized. It can be concluded that the effect of parallel spin in the Co2 molecule is larger than the effect of the conjugated molecule,which is obviously related to the effect of electron d delocalization. In addition, the Murrell-Sorbie potential functions with the parameters for the ground state and the other states of the Co2 molecule are derived. The dissociation energy De for the ground state of Co2 molecule is 4.0489eV, equilibrium bond length Re is 0.2061 nm, and vibration frequency 11.2222 aJ.nm-4respectively(1 a.J=10-18 J). The other spectroscopic data for the ground state of Co2 molecule ωexe,Be, and αe are 0.7202 cm-1, 0.1347 cm-1, and 2.9120× 10-1 cm-1 respectively. And ωexe is the non-syntonic part of frequency, Be is the rotational constant, αe is revised constant of rotational constant for non-rigid part of Co2 molecule.

  9. Structurally simple complexes of CO2

    OpenAIRE

    Murphy, Luke J.; Robertson, Katherine N.; Richard A. Kemp; TUONONEN, Heikki; Clyburne, Jason A. C.

    2015-01-01

    The ability to bind CO2 through the formation of low-energy, easily-broken, bonds could prove invaluable in a variety of chemical contexts. For example, weak bonds to CO2 would greatly decrease the cost of the energy-intensive sorbent-regeneration step common to most carbon capture technologies. Furthermore, exploration of this field could lead to the discovery of novel CO2 chemistry. Reduction of complexed carbon dioxide might generate chemical feedstocks for the preparation of value-added p...

  10. The Idea of Global CO2 Trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    1999-01-01

    The US has been criticized for wanting to earn a fortune on a global CO2 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 CO2 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 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. Component-specific dynamics of riverine mangrove CO2 efflux in the Florida coastal Everglades

    Science.gov (United States)

    Troxler, Tiffany G.; Barr, Jordan G.; Fuentes, Jose D.; Engel, Victor C.; Anderson, Gordon H.; Sanchez, Christopher; Lagomosino, David; Price, Rene; Davis, Stephen E.

    2015-01-01

    Carbon cycling in mangrove forests represents a significant portion of the coastal wetland carbon (C) budget across the latitudes of the tropics and subtropics. Previous research suggests fluctuations in tidal inundation, temperature and salinity can influence forest metabolism and C cycling. Carbon dioxide (CO2) from respiration that occurs from below the canopy is contributed from different components. In this study, we investigated variation in CO2 flux among different below-canopy components (soil, leaf litter, course woody debris, soil including pneumatophores, prop roots, and surface water) in a riverine mangrove forest of Shark River Slough estuary, Everglades National Park (Florida, USA). The range in CO2 flux from different components exceeded that measured among sites along the oligohaline-saline gradient. Black mangrove (Avicennia germinans) pneumatophores contributed the largest average CO2 flux. Over a narrow range of estuarine salinity (25–35 practical salinity units (PSU)), increased salinity resulted in lower CO2 flux to the atmosphere. Tidal inundation reduced soil CO2 flux overall but increased the partial pressure of CO2 (pCO2) observed in the overlying surface water upon flooding. Higher pCO2 in surface water is then subject to tidally driven export, largely as HCO3. Integration and scaling of CO2 flux rates to forest scale allowed for improved understanding of the relative contribution of different below-canopy components to mangrove forest ecosystem respiration (ER). Summing component CO2fluxes suggests a more significant contribution of below-canopy respiration to ER than previously considered. An understanding of below-canopy CO2 component fluxes and their contributions to ER can help to elucidate how C cycling will change with discrete disturbance events (e.g., hurricanes) and long-term change, including sea-level rise, and potential impact mangrove forests. As such, key controls on below-canopy ER must be taken into consideration when

  12. Importance of nondiffusive transport for soil CO2 efflux in a temperate mountain grassland.

    Science.gov (United States)

    Roland, Marilyn; Vicca, Sara; Bahn, Michael; Ladreiter-Knauss, Thomas; Schmitt, Michael; Janssens, Ivan A

    2015-03-01

    Soil respiration and its biotic and abiotic drivers have been an important research topic in recent years. While the bulk of these efforts has focused on the emission of CO2 from soils, the production and subsequent transport of CO2 from soil to atmosphere received far less attention. However, to understand processes underlying emissions of CO2 from terrestrial ecosystems, both processes need to be fully evaluated. In this study, we tested to what extent the transport of CO2 in a grassland site in the Austrian Alps could be modeled based on the common assumption that diffusion is the main transport mechanism for trace gases in soils. Therefore, we compared the CO2 efflux calculated from the soil CO2 concentration gradient with the CO2 efflux from chamber measurements. We used four commonly used diffusion-driven models for the flux-gradient approach. Models generally underestimated the soil chamber effluxes and their amplitudes, indicating that processes other than diffusion were responsible for the transport of CO2. We further observed that transport rates correlated well with irradiation and, below a soil moisture content of 33%, with wind speed. This suggests that mechanisms such as bulk soil air transport, due to pressure pumping or thermal expansion of soil air due to local surface heating, considerably influence soil CO2 transport at this site. Our results suggest that nondiffusive transport may be an important mechanism influencing diel and day-to-day dynamics of soil CO2 emissions, leading to a significant mismatch (10-87% depending on the model used) between the two approaches at short time scales.

  13. Hydrogeological characterization of shallow-depth zone for CO2 injection and leak test at a CO2 environmental monitoring site in Korea

    Science.gov (United States)

    Lee, S. S.; Kim, T. W.; Kim, H. H.; Ha, S. W.; Jeon, W. T.; Lee, K. K.

    2015-12-01

    The main goal of the this study is to evaluate the importance of heterogeneities in controlling the field-scale transport of CO2 are originated from the CO2 injected at saturated zone below the water table for monitoring and prediction of CO2 leakage from a reservoir. Hydrogeological and geophysical data are collected to characterize the site, prior to conducting CO2 injection experiment at the CO2 environmental monitoring site at Eumseong, Korea. The geophysical data were acquired from borehole electromagnetic flowmeter tests, while the hydraulic data were obtained from pumping tests, slug tests, and falling head permeability tests. Total of 13 wells to perform hydraulic and geophysical test are established along groundwater flow direction in regular sequence, revealed by the results of borehole electromagnetic flowmeter test. The results of geophysical tests indicated that hydraulic gradient is not identical with the topographic gradient. Groundwater flows toward the uphill direction in the study area. Then, the hydraulic tests were conducted to identify the hydraulic properties of the study site. According to the results of pumping and slug tests at the study site, the hydraulic conductivity values show ranges between 4.75 x 10-5 cm/day and 9.74 x 10-5 cm/day. In addition, a portable multi-level sampling and monitoring packer device which remains inflated condition for a long period developed and used to isolate designated depths to identify vertical distribution of hydrogeological characteristics. Hydrogeological information obtained from this study will be used to decide the injection test interval of CO2-infused water and gaseous CO2. Acknowledgement: Financial support was provided by "R&D Project on Environmental Mangement of Geologic CO2 Storage" from the KEITI (Project Number: 2014001810003).

  14. Porous-medium convection: new problems from CO2 sequestration

    Science.gov (United States)

    Lister, John

    2013-11-01

    Large scale injection and storage of supercritical carbon dioxide (CO2) into deep saline aquifers is proposed to offset anthropogenic emissions and mitigate climate change. Many aspects of the resultant porous flows provoke fundamental fluid-mechanical problems. The rise and spread of the buoyant CO2 plume beneath an overlying impermeable stratum is a classic gravity current, but with the undesirable extra possibility of upward leakage through fractures. Fortunately, long-term trapping mechanisms exist. One such, dissolution of CO2 into the underlying brine, produces a denser solution which thus convects reassuringly downwards. Consideration of the convective flux prompts re-examination of high-Ra convection in a porous medium, which is found to have a strikingly different asymptotic form from that in a pure fluid. The high-Ra regime of Rayleigh-Darcy convection has an ordered interior with a linear mean temperature gradient and a superposed vertical columnar heat-exchanger flow whose wavelength is consistent with the Ra - 5 / 14 scaling predicted by an asymptotic stability analysis. Quantification of the convective dissolution flux allows evolution towards saturation in confined aquifers, or the erosion of a gravity current in open aquifers, to be calculated.

  15. Climate change and agroecosystems: the effect of elevated atmospheric CO2 and temperature on crop growth, development, and yield

    Directory of Open Access Journals (Sweden)

    Streck Nereu Augusto

    2005-01-01

    Full Text Available The amount of carbon dioxide (CO2 of the Earths atmosphere is increasing, which has the potential of increasing greenhouse effect and air temperature in the future. Plants respond to environment CO2 and temperature. Therefore, climate change may affect agriculture. The purpose of this paper was to review the literature about the impact of a possible increase in atmospheric CO2 concentration and temperature on crop growth, development, and yield. Increasing CO2 concentration increases crop yield once the substrate for photosynthesis and the gradient of CO2 concentration between atmosphere and leaf increase. C3 plants will benefit more than C4 plants at elevated CO2. However, if global warming will take place, an increase in temperature may offset the benefits of increasing CO2 on crop yield.

  16. CO2 emissions in the steel industry

    Directory of Open Access Journals (Sweden)

    M. Kundak

    2009-07-01

    Full Text Available Global CO2 emissions caused by the burning of fossil fuels over the past century are presented. Taking into consideration the total world production of more than 1,3 billion tons of steel, the steel industry produces over two billion tons of CO2. Reductions in CO2 emissions as a result of technological improvements and structural changes in steel production in industrialized countries during the past 40 years are described. Substantial further reductions in those emissions will not be possible using conventional technologies. Instead, a radical cutback may be achieved if, instead of carbon, hydrogen is used for direct iron ore reduction. The cost and the ensuing CO2 generation in the production of hydrogen as a reducing agent from various sources are analysed.

  17. Hoeveel CO2 kostte deze paprika?

    NARCIS (Netherlands)

    Smit, P.X.

    2011-01-01

    Ondernemers in de tuinbouwsector kunnen dankzij een nieuw protocol de CO2-voetafdruk van hun product van zaaigoed tot supermarktschap berekenen. Daarbij zit een tool die de telers, handelaren en transporteurs kan laten zien waar de uitstoot plaatsvindt.

  18. Compact, High Accuracy CO2 Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovative Research Phase II proposal seeks to develop a low cost, robust, highly precise and accurate CO2 monitoring system. This system will...

  19. Translucent CO2 ice on Mars ?

    Science.gov (United States)

    Schmidt, Frederic; Andrieu, Francois; Douté, Sylvain; Schmitt, Bernard

    2016-10-01

    The Martian climate is driven by the condensation/sublimation of CO2 representing 95% of the atmosphere. Many active surface features (such dark spot, dark flows), have been potentially linked to CO2 exchange. Understanding the surface/atmosphere interactions is a major issue, for both atmospheric but also surface science. This study aims at estimating the physical properties of the seasonal CO2 ice deposits. Are these deposits granular or compact? What is the thickness of the ice? How much impurities are included within the ice? These questions have been highly debated in the literature, in particular the presence of a translucent slab ice, the link with the H2O cycle. In particular the cold jet geyser model requires translucent CO2 ice. We use radiative transfer models to simulate spectroscopic data from the CRISM instrument and perform an inversion to estimate model's parameters though time. We then discuss the consistency of the results with other datasets.

  20. Compact, High Accuracy CO2 Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovative Research Phase I proposal seeks to develop a low cost, robust, highly precise and accurate CO2 monitoring system. This system will...

  1. 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.

  2. 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....

  3. CO2 Removal from Mars EMU Project

    Data.gov (United States)

    National Aeronautics and Space Administration — CO2 control for during ExtraVehicular Activity (EVA) on mars is challenging. Lithium hydroxide (LiOH) canisters have impractical logistics penalties, and regenerable...

  4. CO2 phytotron established in Ailaoshan Mountains

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Understanding the Uinteractions between ecological systems and the environment is a priority for the studies of global change, evolutionary biology, and functional genomics.Controlled environment facilities,like CO2 phytotrons, are necessary for acquiring such an understanding.

  5. CO2 Removal from Mars EMU Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A practical CO2 control system for ExtraVehicular Activity (EVA) on Mars have not yet been developed. TDA Research, Inc. proposes to develop a durable,...

  6. Seaweed community response to a massive CO2 input

    Science.gov (United States)

    Sangil, Carlos; Clemente, Sabrina; Brito, Alberto; Rodríguez, Adriana; Balsalobre, Marc; Mendoza, José Carlos; Martínez, David; Hernández, José Carlos

    2016-09-01

    Changes in the structure of seaweed communities were examined following a massive CO2 input caused by a submarine eruption near the coast of El Hierro island (Canary Islands, Spain). The event lasted almost five months (October 2011-March 2012) and created a significant pH gradient. Specifically, we compared three different zones: highly affected with extreme low pH (6.7-7.3), affected with low pH (7.6-7.8), and unaffected ambient pH zone (∼8.1) according to the pH gradient generated by the predominate currents and waves in the south of the island. Studies were carried out before, during and after the CO2 input event in each zone. We found community-wide effects on seaweed communities during the eruption; these included changes in species abundance and changes in the diversity. However, changes in all these community traits were only evident in the highly affected zone, where there were major shifts in the seaweed community, with a replacement of Lobophora variegata by ephemeral seaweeds. Lobophora variegata dropped in cover from 87-94 to 27% while ephemeral seaweeds increased 6-10 to 29%. When the impact ended Lobophora variegata began to recover reaching a cover higher than 60%. In the moderate affected area the Lobophora variegata canopies maintained their integrity avoiding phase shifts to turfs. Here the only significant changes were the reduction of the cover of the crustose and geniculate coralline algae.

  7. Combustion of hythane diluted with CO2

    Directory of Open Access Journals (Sweden)

    Hraiech Ibtissem

    2015-01-01

    Full Text Available With increasing concern about energy shortage and environmental protection, improving engine fuel economy and reducing exhaust emissions have become major research topics in combustion and engine development. Hythane (a blend of hydrogen H2 and natural gas NG has generated a significant interest as an alternative fuel for the future. This paper describes an experimental study of the effects of CO2 addition on the stability of a turbulent jet diffusion NG-H2 flame. The mole fraction of hydrogen (% H2 in NG-H2 mixture was varied from 0% to 50%. The equivalence ratio of the hythane/CO2/air mixture was kept at stoichiometry. The results show that the lift-off height increases with the addition of CO2 at various % H2 content in hythane. However, we observe that with 20% H2, we can obtain a stable flame diluted with 40% CO2, while for 0% H2, the flame is blown out above 20% CO2. This means that the limits of flame blowing out are pushed with the additions of H2. Moreover, the results show that for %H2 content in NG-H2 fuel up to 10%, the addition of CO2 could produce lifted flame if the % CO2 is low. At higher % CO2 dilution, flame would remain attached until blow-out. This is mainly due to the fact that the dilution leads to ejection velocities very high but reactivity of the mixture does not change so the flame tends to stretch.

  8. Udvikling af CO2 neutralt byrumsarmatur

    DEFF Research Database (Denmark)

    Poulsen, Peter Behrensdorff; Dam-Hansen, Carsten; Corell, Dennis Dan

    Denne rapport indeholder en beskrivelse af arbejdet udført i og resultaterne af forsknings- og udviklingsprojektet ” Udvikling af CO2 neutralt byrumsarmatur” og udgør slutrapportering for dette projekt.......Denne rapport indeholder en beskrivelse af arbejdet udført i og resultaterne af forsknings- og udviklingsprojektet ” Udvikling af CO2 neutralt byrumsarmatur” og udgør slutrapportering for dette projekt....

  9. The Twelve Principles of CO2 CHEMISTRY.

    Science.gov (United States)

    Poliakoff, Martyn; Leitner, Walter; Streng, Emilia S

    2015-01-01

    This paper introduces a set of 12 Principles, based on the acronym CO2 CHEMISTRY, which are intended to form a set of criteria for assessing the viability of different processes or reactions for using CO2 as a feedstock for making organic chemicals. The principles aim to highlight the synergy of Carbon Dioxide Utilisation (CDU) with the components of green and sustainable chemistry as well as briefly pointing out the connection to the energy sector.

  10. The twelve principles of CO2 Chemistry

    OpenAIRE

    Poliakoff, Martyn; Leitner, Walter; Streng, Emelia S.

    2015-01-01

    This paper introduces a set of 12 Principles, based on the acronym CO2 CHEMISTRY, which are intended to form a set of criteria for assessing the viability of different processes or reactions for using CO2 as a feedstock for making organic chemicals. The principles aim to highlight the synergy of Carbon Dioxide Utilisation (CDU) with the components of green and sustainable chemistry as well as briefly pointing out the connection to the energy sector.

  11. Trapping atmospheric CO2 with gold.

    Science.gov (United States)

    Collado, Alba; Gómez-Suárez, Adrián; Webb, Paul B; Kruger, Hedi; Bühl, Michael; Cordes, David B; Slawin, Alexandra M Z; Nolan, Steven P

    2014-10-07

    The ability of gold-hydroxides to fix CO2 is reported. [Au(IPr)(OH)] and [{Au(IPr)}2(μ-OH)][BF4] react with atmospheric CO2 to form the trigold carbonate complex [{Au(IPr)}3(μ(3)-CO3)][BF4]. Reactivity studies revealed that this complex behaves as two basic and one cationic Au centres, and that it is catalytically active. DFT calculations and kinetic experiments have been carried out.

  12. Supercritical CO2 Extraction of Ethanol

    OpenAIRE

    GÜVENÇ, A.; MEHMETOĞLU, Ü.; ÇALIMLI, A.

    1999-01-01

    Extraction of ethanol was studied from both synthetic ethanol solution and fermentation broth using supercritical CO2 in an extraction apparatus in ranges of 313 to 333 K and 80 to 160 atmospheres, for varying extraction times. The experimental system consists mainly of four parts: a CO2 storage system, a high-pressure liquid pump, an extractor and a product collection unit. Samples were analyzed by gas chromatography. Effects of temperature, pressure, extraction time, initial ethan...

  13. Reducing CO2 emission from bitumen upgrading

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, John

    2011-07-15

    The treatment of sand oil can result in significant CO2 emission. Ceramatec Inc. has developed a technology to reduce the emission of CO2 during the upgrading of feedstocks bearing heteroatoms. This technology can be applied to kerogen derived oil (shale oil) and heavy oil as well as to bitumen from oil sands. Metallic sodium is used as the reducing and heteroatom scavenging agent. Hydrogen, methane or other hydrocarbons may be used to cap radicals formed in the process. But using methane can lead to lower material and capital costs, greater product yield, and lower CO2 emission. During the upgrading process, the aromatic constituents remain in the product, after treatment with sodium and removal of sulphur, nitrogen and metals. Aromatic saturation is not required with sodium, so less hydrogen is needed which leads to reduced CO2 emission. The reason is that CO2 is emitted in the steam methane reforming (SMR) process where hydrogen is produced. An example is introduced to demonstrate the reduction of CO2 emission from hydrogen production. Another advantage of the sodium/methane upgrading process is the incorporation of methane into the fuel. In addition, the total acid number, TAN, becomes negligible in the sodium upgrading processes. Ceramatec has also developed a process for the recovery of sodium from the sodium salts generated in the sodium/methane upgrading process.

  14. Density of aqueous solutions of CO2

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Julio E.

    2001-10-10

    In this report, we present a numerical representation for the partial molar volume of CO2 in water and the calculation of the corresponding aqueous solution density. The motivation behind this work is related to the importance of having accurate representations for aqueous phase properties in the numerical simulation of carbon dioxide disposal into aquifers as well as in geothermal applications. According to reported experimental data the density of aqueous solutions of CO2 can be as much as 2-3% higher than pure water density. This density variation might produce an influence on the groundwater flow regime. For instance, in geologic sequestration of CO2, convective transport mixing might occur when, several years after injection of carbon dioxide has stopped, the CO2-rich gas phase is concentrated at the top of the formation, just below an overlaying caprock. In this particular case the heavier CO2 saturated water will flow downward and will be replaced by water with a lesser CO2 content.

  15. CO2 efflux from cleared mangrove peat.

    Directory of Open Access Journals (Sweden)

    Catherine E Lovelock

    Full Text Available BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSIONS/SIGNIFICANCE: 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.

  16. 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

  17. Application of CO2 in BOF%转炉应用CO2技术

    Institute of Scientific and Technical Information of China (English)

    万雪峰; 曹东; 刘祥; 朱晓雷; 廖相巍

    2015-01-01

    By the thermodynamic analysis of top blowing CO2 in the converter,combined with laboratory simulation re-sult of top blowing O2+CO2 mixture gas in converter,some key parameters of CO2 used in converter were established. It is concluded that although pure CO2 injected in the converter could achieve decarburize,the drop of temperature was rath-er large. When the CO2 supplying intensity was 3.0 m3/(t·min),the reduction of temperature was 15.1℃/min;By blow-ing O2+CO2 mixture gas,temperature balance could be realized,but the largest theoretical proportion of CO2 in mixture gas was 79.1%;with the increase of CO2 proportion,the carbon and oxygen product of molten steel at the blowing end was reduced,under the condition of φ(CO2)∶φ(O2)=1∶1,the carbon and oxygen product could be controlled in the range of (25~32)×10-8.%通过对转炉顶吹CO2的热力学分析,结合实验室模拟转炉顶吹O2+CO2混合气体试验结果,确立了CO2在转炉中应用的关键参数。得出在转炉中顶吹纯CO2虽可脱碳,但温降较大,顶吹CO2供气强度为3.0 m3/(t·min)时,钢液温降速率为15.1℃/min;通过喷吹O2+CO2混合气体可实现温度平衡,但CO2配比的最大理论比例为79.1%;随着混合气体中CO2比例增大,吹炼终点钢液碳氧积降低,当φ(CO2)∶φ(O2)=1∶1时可控碳氧积为(25~32)×10-8。

  18. Precursory volcanic CO2 signals from space

    Science.gov (United States)

    Schwandner, Florian M.; Carn, Simon A.; Kataoka, Fumie; Kuze, Akihiko; Shiomi, Kei; Goto, Naoki

    2016-04-01

    Identification of earliest signals heralding volcanic unrest benefits from the unambiguous detection of precursors that reflect deviation of magmatic systems from metastable background activity. Ascent and emplacement of new basaltic magma at depth may precede eruptions by weeks to months. Transient localized carbon dioxide (CO2) emissions stemming from exsolution from depressurized magma are expected, and have been observed weeks to months ahead of magmatic surface activity. Detecting such CO2 precursors by continuous ground-based monitoring operations is unfortunately not a widely implemented method yet, save a handful of volcanoes. Detecting CO2 emissions from space offers obvious advantages - however it is technologically challenging, not the least due to the increasing atmospheric burden of CO2, against which a surface emission signal is hard to discern. In a multi-year project, we have investigated the feasibility of space-borne detection of pre-eruptive volcanic CO2 passive degassing signals using observations from the Greenhouse Gas Observing SATellite (GOSAT). Since 2010, we have observed over 40 active volcanoes from space using GOSAT's special target mode. Over 72% of targets experienced at least one eruption over that time period, demonstrating the potential utility of space-borne CO2 observations in non-imaging target-mode (point source monitoring mode). While many eruption precursors don't produce large enough CO2 signals to exceed space-borne detection thresholds of current satellite sensors, some of our observations have nevertheless already shown significant positive anomalies preceding eruptions at basaltic volcanoes. In 2014, NASA launched its first satellite dedicated to atmospheric CO2 observation, the Orbiting Carbon Observatory (OCO-2). Its observation strategy differs from the single-shot GOSAT instrument. At the expense of GOSAT's fast time series capability (3-day repeat cycle, vs. 16 for OCO-2), its 8-footprint continuous swath can slice

  19. Transport of bromide measured by soil coring, suction plates, and lysimeters under transient flow conditions.

    Science.gov (United States)

    Kasteel, R.; Pütz, Th.; Vereecken, H.

    2003-04-01

    Lysimeter studies are one step within the registration procedure of pesticides. Flow and transport in these free-draining lysimeters do not reflect the field situation mainly because of the occurence of a zone of local saturation at the lower boundary (seepage face). The objective of this study is to evaluate the impact of flow and transport behaviour of bromide detected with different measuring devices (lysimeters, suction plates, and soil coring) by comparing experimental results with numerical simulations in heterogeneous flow domains. We applied bromide as a small pulse to the bare soil surface (Orthic Luvisol) of the three devices and the displacement of bromide was regurlarly sampled for three years under natural wheather conditions. Based on the mean breakthrough curves we observe experimentally that lysimeters have a lower effective pore-water velocity and exhibit more solute spreading resulting in a larger dispersivity than the suction plates. This can be ascribed to the artefact of the lower boundary. We performed numerical transport simulations in 2-D heterogeneous flow fields (scaling approach) choosing appropriate boundary conditions for the various devices. The simulations allow to follow the temporal evolution of flow and transport processes in the various devices and to gain additional process understanding. We conclude that the model is essentially capable to reproduce the main experimental findings only if we account for the spatial correlation structure of the hydraulic properties, i.e. soil heterogeneity.

  20. Ecotoxicity and fate of a silver nanomaterial in an outdoor lysimeter study.

    Science.gov (United States)

    Schlich, Karsten; Hoppe, Martin; Kraas, Marco; Fries, Elke; Hund-Rinke, Kerstin

    2017-08-01

    Sewage sludge is repeatedly applied as fertilizer on farmland due to its high nutrient content. This may lead to a significant increase of silver nanomaterials (AgNM) in soil over years. Therefore, our aim was to investigate the ecotoxicity and fate of AgNM under environmentally relevant conditions in outdoor lysimeters over 25 months. Two AgNM concentrations (1.7 and 8.0 mg/kg dry matter soil) were applied via sewage sludge into soil. In subsamples of the soil, incubated under laboratory conditions for 180 days, the comparability of outdoor and laboratory results regarding ecotoxicity was determined. The results from our long term lysimeter experiments show no detectable horizontal displacement in combination with very low remobilization to the percolate water. Thus, indicate that the sludge applied AgNM remains nearly immobile in the pathway between soils and leachate. However, Ag uptake to the roots of wheat and canola suggests that the chemical conditions in the rhizosphere induce AgNM remobilization from the incorporated sewage sludge even after two harvesting cycles. At the higher AgNM concentration a steady inhibition of the soil microflora was observed over 25 month in the lysimeter study, while there was no effect at the lower AgNM concentration. The results of the laboratory experiment reflect the findings of the lysimeter study and indicate that a risk assessment for AgNM based on data from laboratory tests is acceptable.

  1. Annual Report for Gravity Collection Lysimeter Monitoring Plan – ERDF Cells 5 and 6

    Energy Technology Data Exchange (ETDEWEB)

    M. L. Proctor

    2006-04-04

    The data and analyses contained in this report reflect the initial characterization of construction and consolidation water in Cells 5 and 6 lysimeters. Therefore, the scope of this report will be to establish constituent levels and document dewatering activities completed to date.

  2. In situ sensors, weighing lysimeters and COSMOS under vegetated and bare conditions with subsurface drip irrigation

    Science.gov (United States)

    Long term weighing lysimeter records may have utility for assessment of climate changes occurring during the period of record. They typically enclose a depth of soil that exceeds the root zone of vegetation normally grown on them and have drainagy systems so that more or less natural hydrologic flux...

  3. Ontwikkeling in de tijd van de vegetatie op lysimeters met olieverontreinging te Katwijk

    NARCIS (Netherlands)

    Kemmers, R.H.

    1981-01-01

    Deze nota vormt een verslag van floristisch onderzoek van een twaalftal lysimeters in de duinen nabij Katwijk en vormt een onderdeel van het onderzoek naar de afbraaksnelheid van olie in de bodem onder invloed van miçro-organismen, dat door het Contactcentrum Olie-industrie en Openbare Watervoorzien

  4. Enhancement of non-CO2 radiative forcing via intensified carbon cycle feedbacks

    Science.gov (United States)

    MacDougall, Andrew H.; Knutti, Reto

    2016-06-01

    The global carbon cycle is sensitive to changes in global temperature and atmospheric CO2 concentration, with increased temperature tending to reduce the efficiency of carbon sinks and increased CO2 enhancing the efficiency of carbon sinks. The emission of non-CO2 greenhouse gases warms the Earth but does not induce the CO2 fertilization effect or increase the partial-pressure gradient between the atmosphere and the surface ocean. Here we present idealized climate model experiments that explore the indirect interaction between non-CO2 forcing and the carbon cycle. The experiments suggest that this interaction enhances the warming effect of the non-CO2 forcing by up to 25% after 150 years and that much of the warming caused by these agents lingers for over 100 years after the dissipation of the non-CO2 forcing. Overall, our results suggest that the longer emissions of non-CO2 forcing agents persists the greater effect these agents will have on global climate.

  5. Primary, secondary, and tertiary amines for CO2 capture: designing for mesoporous CO2 adsorbents.

    Science.gov (United States)

    Ko, Young Gun; Shin, Seung Su; Choi, Ung Su

    2011-09-15

    CO(2) emissions, from fossil-fuel-burning power plants, the breathing, etc., influence the global worming on large scale and the man's work efficiency on small scale. The reversible capture of CO(2) is a prominent feature of CO(2) organic-inorganic hybrid adsorbent to sequester CO(2). Herein, (3-aminopropyl) trimethoxysilane (APTMS), [3-(methylamino)propyl] trimethoxysilane (MAPTMS), and [3-(diethylamino) propyl] trimethoxysilane (DEAPTMS) are immobilized on highly ordered mesoporous silicas (SBA-15) to catch CO(2) as primary, secondary, and tertiary aminosilica adsorbents. X-ray photoelectron spectroscopy was used to analyze the immobilized APTMS, MAPTMS, and DEAPTMS on the SBA-15. We report an interesting discovery that the CO(2) adsorption and desorption on the adsorbent depend on the amine type of the aminosilica adsorbent. The adsorbed CO(2) was easily desorbed from the adsorbent with the low energy consumption in the order of tertiary, secondary, and primary amino-adsorbents while the adsorption amount and the bonding-affinity increased in the reverse order. The effectiveness of amino-functionalized (1(o), 2(o), and 3(o) amines) SBA-15s as a CO(2) capturing agent was investigated in terms of adsorption capacity, adsorption-desorption kinetics, and thermodynamics. This work demonstrates apt amine types to catch CO(2) and regenerate the adsorbent, which may open new avenues to designing "CO(2) basket".

  6. 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.

  7. Accelerated carbonation of steel slags using CO2 diluted sources: CO2 uptakes and energy requirements

    Directory of Open Access Journals (Sweden)

    Renato eBaciocchi

    2016-01-01

    Full Text Available This work presents the results of carbonation experiments performed on Basic Oxygen Furnace (BOF steel slag samples employing gas mixtures containing 40 and 10% CO2 vol. simulating the gaseous effluents of gasification and combustion processes respectively, as well as 100% CO2 for comparison purposes. Two routes were tested, the slurry phase (L/S=5 l/kg, T=100 °C and Ptot=10 bar and the thin film (L/S =0.3-0.4 l/kg, T=50 °C and Ptot=7-10 bar routes. For each one, the CO2 uptake achieved as a function of the reaction time was analyzed and on this basis the energy requirements associated to each carbonation route and gas mixture composition were estimated considering to store the CO2 emissions of a medium size natural gas fired power plant (20 MW. For the slurry phase route, maximum CO2 uptakes ranged from around 8% at 10% CO2, to 21.1% (BOF-a and 29.2% (BOF-b at 40% CO2 and 32.5% (BOF-a and 40.3% (BOF-b at 100% CO2. For the thin film route, maximum uptakes of 13% (BOF-c and 19.5% (BOF-d at 40% CO2, and 17.8% (BOF-c and 20.2% (BOF-d at 100% were attained. The energy requirements of the two analyzed process routes appeared to depend chiefly on the CO2 uptake of the slag. For both process route, the minimum overall energy requirements were found for the tests with 40% CO2 flows (i.e. 1400-1600 MJ/t CO2 for the slurry phase and 2220-2550 MJ/t CO2 for the thin film route.

  8. Effect of Elevated CO2 and Drought on Soil Microbial Communities Associated with Andropogon gerardii

    Institute of Scientific and Technical Information of China (English)

    Issmat I. Kassem; Puneet Joshi; Von Sigler; Scott Heckathorn; Qi Wang

    2008-01-01

    Our understanding of the effects of elevated atmospheric CO2, singly and In combination with other environmental changes,on plant-soil interactions is incomplete. Elevated CO2 effects on C4 plants, though smaller than on C3 species, are mediated mostly via decreased stomatal conductance and thus water loss. Therefore, we characterized the interactive effect of elevated CO2 and drought on soil microbial communities associated with a dominant C4 prairie grass, Andropogon gerardii Vitman. Elevated CO2 and drought both affected resources available to the soil microbial community. For example, elevated CO2 increased the soil C:N ratio and water content during drought, whereas drought alone decreased both. Drought significantly decreased soil microbial biomass. In contrast, elevated COz increased biomass while ameliorating biomass decreases that were induced under drought. Total and active direct bacterial counts and carbon substrate use (overall use and number of used sources) increased significantly under elevated CO2. Denaturing gradient gel electrophoresis analysis revealed that drought and elevated CO2, singly and combined, did not affect the soil bacteria community structure.We conclude that elevated CO2 alone increased bacterial abundance and microbial activity and carbon use, probably in response to increased root exudation. Elevated CO2 also limited drought-related impacts on microbial activity and biomass,which likely resulted from decreased plant water use under elevated CO2. These are among the first results showing that elevated CO2 and drought work in opposition to modulate plant-associated soil-bacteria responses,which should then Influence soil resources and plant and ecosystem function.

  9. Control of Rubisco function via homeostatic equilibration of CO2 supply

    Directory of Open Access Journals (Sweden)

    Abir U Igamberdiev

    2015-02-01

    Full Text Available Rubisco is the most abundant protein on Earth that serves as the primary engine of carbon assimilation. It is characterized by a slow rate and low specificity for CO2 leading to photorespiration. We analyze here the challenges of operation of this enzyme as the main carbon fixation engine. The high concentration of Rubisco exceeds that of its substrate CO2 by 2–3 orders of magnitude; however, the total pool of available carbon in chloroplast, i.e. mainly bicarbonate, is comparable to the concentration of Rubisco active sites. This makes the reactant stationary assumption (RSA, which is essential as a condition of satisfying the Michaelis-Menten (MM kinetics, valid if we assume that the delivery of CO2 from this pool is not limiting. The RSA is supported by active carbonic anhydrases (CA that quickly equilibrate bicarbonate and CO2 pools and supply CO2 to Rubisco. While the operation of stromal CA is independent of light reactions, the thylakoidal CA associated with PSII and pumping CO2 from the thylakoid lumen is coordinated with the rate of electron transport, water splitting and proton gradient across the thylakoid membrane. At high CO2 concentrations, CA becomes less efficient (the equilibrium becomes unfavourable, so a deviation from the MM kinetics is observed, consistent with Rubisco reaching its Vmax at approximately 50% lower level than expected from the classical MM curve. Previously, this deviation was controversially explained by the limitation of RuBP regeneration. At low ambient CO2 and correspondingly limited capacity of the bicarbonate pool, its depletion at Rubisco sites is relieved in that the enzyme utilizes O2 instead of CO2, i.e. by photorespiration. In this process, CO2 is supplied back to Rubisco, and the chloroplastic redox state and energy level are maintained. It is concluded that the optimal performance of photosynthesis is achieved via the provision of continuous CO2 supply to Rubisco by carbonic anhydrases and

  10. 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, CO2 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 CO2 has a lower density than the resident formation brine and thus migrates upward due to buoyancy forces. To prevent the CO2 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 CO2 cannot percolate), (2) residual trapping (where the CO2 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 CO2 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 CO2 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 CO2 through the rock are strongly influenced by the CO2-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 CO2-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 CO2-wet. Note that CO2-wet surfaces dramatically reduce CO2 storage capacities. Furthermore, increasing pressure, salinity, or dissolved ion valency increases CO2-wettability, while the effect of temperature is not well understood. Indeed theoretical understanding of CO2-wettability and the ability to

  11. Carbon Dioxide Clusters: (CO_2)_6 to (CO_2)13

    Science.gov (United States)

    McKellar, A. R. W.; Oliaee, J. Norooz; Dehghany, M.; Moazzen-Ahmadi, N.

    2011-06-01

    We recenty reported assignments of specific infrared bands in the CO_2 νb{3} region (˜2350 wn) to (CO_2)_6, (CO_2)_7, (CO_2)_9, (CO_2)10, (CO_2)11, (CO_2)12, and (CO_2)13. Spectra are obtained by direct absorption using a rapid-scan tuneable diode laser spectrometer to probe a pulsed supersonic slit-jet expansion and assignments are facilitated by recent calculations of Takeuchi based on the Murthy potential. (CO_2)_6 is a symmetric top with S_6 point group symmetry which can be thought of as a stack of two planar cyclic trimers. (CO_2)13 is also an S_6 symmetric top, and consists of a single CO_2 monomer surrounded by an slightly distorted icosahedral cage. The remaining clusters are asymmetric tops without symmetry. Here we report additional CO_2 cluster results. Calculations based on the SAPT-s potential indicate that the structure of (CO_2)10 may be slightly different from that given by Takeuchi/Murthy. An additional band is observed for each of (CO_2)13 and (CO_2)10. A feature observed at 2378.2 wn is assigned as a (CO_2)_6 parallel combination band involving the sum of a fundamental and a low-lying intermolecular vibration. Most significantly, two bands are assigned to a second isomer of (CO_2)_6. This is also a symmetric top, but now with S_4 symmetry. The two symmetric hexamer isomers observed spectroscopically correspond well with the lowest energy structures given by both the SAPT-s and Murthy intermolecular potentials. [1] J. Norooz Oliaee, M. Dehgany, N. Moazzen-Ahmadi, and A.R.W. McKellar, Phys. Chem. Chem. Phys. 13, 1297 (2011). [2] H. Takeuchi, J. Phys. Chem. A 107, 5703 (2008); C.S. Murthy, S.F. O'Shea, and I.R. McDonald, Mol. Phys. 50, 531 (1983). [3] R. Bukowski, J. Sadlej, B. Jeziorski, P. Jankowski, K. Szalewicz, S.A. Kucharski, H.L. Williams, and B.M. Rice, J. Chem. Phys. 110, 3785 (1999)

  12. Variably-saturated flow in large weighing lysimeters under dry conditions: inverse and predictive modeling

    Science.gov (United States)

    Iden, Sascha; Reineke, Daniela; Koonce, Jeremy; Berli, Markus; Durner, Wolfgang

    2015-04-01

    A reliable quantification of the soil water balance in semi-arid regions requires an accurate determination of bare soil evaporation. Modeling of soil water movement in relatively dry soils and the quantitative prediction of evaporation rates and groundwater recharge pose considerable challenges in these regions. Actual evaporation from dry soil cannot be predicted without detailed knowledge of the complex interplay between liquid, vapor and heat flow and soil hydraulic properties exert a strong influence on evaporation rates during stage-two evaporation. We have analyzed data from the SEPHAS lysimeter facility in Boulder City (NV) which was installed to investigate the near-surface processes of water and energy exchange in desert environments. The scientific instrumentation consists of 152 sensors per Lysimeter which measured soil temperature, soil water content, and soil water potential. Data from three weighing lysimeters (3 m long, surface area 4 m2) were used to identifiy effective soil hydraulic properties of the disturbed soil monoliths by inverse modeling with the Richards equation assuming isothermal flow conditions. Results indicate that the observed soil water content in 8 different soil depths can be well matched for all three lysimeters and that the effective soil hydraulic properties of the three lysimeters agree well. These results could only be obtained with a flexible model of the soil hydraulic properties which guaranteed physical plausibility of water retention towards complete dryness and accounted for capillary, film and isothermal vapor flow. Conversely, flow models using traditional parameterizations of the soil hydraulic properties were not able to match the observed evaporation fluxes and water contents. After identifying the system properties by inverse modeling, we checked the possibility to forecast evaporation rates by running a fully coupled water, heat and vapor flow model which solved the energy balance of the soil surface. In these

  13. Determining water balance components at a lysimeter site in north-eastern Austria

    Science.gov (United States)

    Nolz, Reinhard; Kammerer, Gerhard; Cepuder, Peter

    2014-05-01

    The water balance of a certain soil profile in a certain time interval is subjected to changes of soil water content within the respective profile, and fluxes at its upper and lower boundary such as evapotranspiration and percolation, respectively. Weighing lysimeters are valuable instruments for water balance studies. Typically, mass changes - thus, changes of soil profile water content - are detected by a weighing system, while percolating water is measured by a tipping bucket or a weighed storage tank, and precipitation is measured by a rain gauge. Consequently, evapotranspiration can be determined by solving a simple water balance equation. However, a typical problem is that using separately measured precipitation data may cause implausible (negative) evapotranspiration. As a solution, the quantities can be determined directly from lysimeter mass changes, which are assumed to be positive due to precipitation and negative due to evapotranspiration. This method requires short measuring intervals and precise data. In this regard, data management of primarily older lysimeter facilities may be improved to fulfil these criteria. At an experimental site in north-eastern Austria hourly water balance components were determined using a reference lysimeter that was installed 1983 and equipped with lever-arm-counterbalance weighing system. A disadvantage of such systems is their sensitivity to external disturbances, mainly forces exerted by wind, which can significantly decrease measuring accuracy. Hence, we firstly studied the mechanical performance of the system regarding wind effects and oscillation behavior, and tested averaging procedures on noisy raw data to enhance measurement accuracy. The measurement accuracy for a wind velocity dew formation was measured, though its total amount was small. Evapotranspiration calculated on daily and hourly base according to ASCE standards indicated good correlation with measured data, but measured values were considerably smaller

  14. CO2 and CO Simulations and Their Source Signature Indicated by CO/CO2

    Science.gov (United States)

    Kawa, Randy; Huisheng, Bian

    2004-01-01

    Three years (2000-2002) atmospheric CO2 and CO fields are simulated by a Chemistry Transport Model driven by the assimilated meteorological fields from GEOS-4. The simulated CO2 and CO are evaluated by measurements from surface (CMDL), satellite (MOPITT/CO), and aircraft. The model-observation comparisons indicate reasonable agreement in both source and remote regions, and in the lower and upper troposphere. The simulation also captures the seasonality of CO2 and CO variations. The ratios of CO/CO2 are analyzed over different representative regions to identify the source signature, since the anthropogenic CO comes fiom the same combustion processes as CO2. This work enables us to improve satellite inversion estimates of CO2 sources and sinks by simultaneously using satellite CO measurement.

  15. The Idea of Global CO2 Trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    1998-01-01

    The US has been criticized for wanting to earn a fortune on a global CO2 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 CO2 market may provide the world with an epoch-making means of cost-effective co...... profitable trade. Also, a periodical renewal of permits makes it possible to tighten target levels in the future.......The US has been criticized for wanting to earn a fortune on a global CO2 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 CO2 market may provide the world with an epoch-making means of cost......-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...

  16. The Idea of Global CO2 Trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    1999-01-01

    The US has been criticized for wanting to earn a fortune on a global CO2 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 CO2 market may provide the world with an epoch-making means of cost-effective co...... 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.......The US has been criticized for wanting to earn a fortune on a global CO2 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 CO2 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 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...

  17. A cost effective CO2 strategy

    DEFF Research Database (Denmark)

    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...... 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......, 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...

  18. Infrared absorption spectroscopy of CO2-HX complexes using the CO2 asymmetric stretch chromophore: CO2HF(DF) and CO2HCl(DCl) linear and CO2HBr bent equilibrium geometries

    Science.gov (United States)

    Sharpe, S. W.; Zeng, Y. P.; Wittig, C.; Beaudet, R. A.

    1990-01-01

    Infrared absorption spectra associated with the CO2 asymmetric stretch vibration have been recorded for weakly bonded gas-phase complexes of CO2 with HF, DF, HCl, DCl, and HBr, using tunable diode laser spectroscopy and a pulsed slit expansion (0.15×38 mm2) that provides >20 MHz overall resolution. Results obtained with CO2-HF are in agreement with earlier studies, in which the HF-stretch region near 3900 cm-1 was examined. In both cases, broad linewidths suggest subnanosecond predissociation. With CO2-DF, the natural linewidths are markedly narrower than with CO2-HF (e.g., 28 vs 182 MHz), and this difference is attributed to slower predissociation, possibly implicating resonances in the case of CO2-HF. Both CO2-HF and CO2-DF exhibited overlapping features: simple P and R branches associated with a linear rotor, and P and R branches containing doublets. As in earlier studies, the second feature can be assigned to either a slightly asymmetric rotor with Ka=1, or a hot band involving a low-frequency intermolecular bend mode. Results obtained with CO2-HCl are in excellent agreement with earlier microwave measurements on the ground vibrational state, and the vibrationally excited state is almost identical to the lower state. Like CO2-DF, linewidths of CO2-HCl and CO2-DCl are much sharper than those of CO2-HF, and in addition, CO2-HCl and CO2-DCl exhibited weak hot bands, as were also evident with CO2-HF and CO2-DF. Upon forming complexes with either HF or HCl, the asymmetric stretch mode of CO2 underwent a blue shift relative to uncomplexed CO2. This can be understood in terms of the nature of the hydrogen bonds, and ab initio calculations are surprisingly good at predicting these shifts. Deuteration of both HF and HCl resulted in further blue shifts of the band origins. These additional shifts are attributed to stronger intermolecular interactions, i.e., deuteration lowers the zero-point energy, and in a highly anharmonic field this results in a more compact average

  19. Numerical study on the potential impact of different bottom boundary conditions on the water balance of lysimeters

    Science.gov (United States)

    Groh, Jannis; Vanderborght, Jan; Pütz, Thomas; Vereecken, Harry

    2014-05-01

    The SOILCan lysimeter network is a large scale climate feedback experiment and is embedded in the four long term observatories of TERENO (TERestrial ENvironmental Observatories). The focus of the SOILCan-project is to observe the impact of climate change on water and matter budgets in different grass- and arable-land lysimeters. The monitoring infrastructure was established across a rainfall and temperature transect along which lysimeters were transported from wetter to drier conditions. The lysimeters in SOILCan have a controlled bottom boundary condition using a rack of suction candles that enables upward and downward flow of water. This pressure head at the bottom is controlled by measured soil water potentials in undisturbed soil in the close vicinity of the bottom of the lysimeter. For transported lysimeters this controlling approach no longer works as the surrounding soil profile and both its upper climatic boundary conditions and lower boundary conditions related to its hydrogeological setting differ from the place where the lysimeter was taken from. In order to evaluate these artefacts and to derive a suited approach to control the lower boundary of transported lysimeters, water balance simulations were run. We analyzed three different approaches to impose bottom boundary conditions for transported lysimeters. A 'zeroth-order' approach is to define the bottom boundary at the bottom of the lysimeter and use the pressure heads measured at the location from which the soil lysimeter was taken. However, this approach is prone to artefacts since these bottom boundary conditions are determined by the climate at the site where the lysimeter was taken from. A 'first-order' approach is to define a bottom boundary condition at a certain hydrogeological boundary that can be defined deeper in the soil profile such as a seepage face or a groundwater table. However, for shallow groundwater tables, this approach may also lead to artefacts since the depth of the groundwater

  20. Investigation into optimal CO2 concentration for CO2 capture from aluminium production

    OpenAIRE

    Mathisen, Anette; Sørensen, Henriette; Melaaen, Morten Christian; Müller, Gunn-Iren

    2013-01-01

    Capture of CO2 from aluminum production has been simulated using Aspen Plus and Aspen Hysys. The technology used for aluminum production is the Hall-Héroult and the current cell design necessitates that large amounts of false air is supplied to the cells. This results in a CO2 concentration in the process gas at around 1 vol%, which is considered uneconomical for CO2 capture. Therefore, the aim of this investigation is to evaluate the CO2 capture from aluminum production when the process g...

  1. Measuring Nitrous Oxide Mass Transfer into Non-Aqueous CO2BOL CO2 Capture Solvents

    Energy Technology Data Exchange (ETDEWEB)

    Whyatt, Greg A.; Freeman, Charles J.; Zwoster, Andy; Heldebrant, David J.

    2016-03-28

    This paper investigates CO2 absorption behavior in CO2BOL solvents by decoupling the physical and chemical effects using N2O as a non-reactive mimic. Absorption measurements were performed using a wetted-wall contactor. Testing was performed using a “first generation” CO2 binding organic liquid (CO2BOL), comprised of an independent base and alcohol. Measurements were made with N2O at a lean (0.06 mol CO2/mol BOL) and rich (0.26 mol CO2/mol BOL) loading, each at three temperatures (35, 45 and 55 °C). Liquid-film mass transfer coefficients (kg') were calculated by subtracting the gas film resistance – determined from a correlation from literature – from the overall mass transfer measurement. The resulting kg' values for N2O in CO2BOLs were found to be higher than that of 5 M aqueous MEA under comparable conditions, which is supported by published measurements of Henry’s coefficients for N2O in various solvents. These results suggest that the physical solubility contribution for CO2 absorption in CO2BOLs is greater than that of aqueous amines, an effect that may pertain to other non-aqueous solvents.

  2. Behavior of CO2/water flow in porous media for CO2 geological storage.

    Science.gov (United States)

    Jiang, Lanlan; Yu, Minghao; Liu, Yu; Yang, Mingjun; Zhang, Yi; Xue, Ziqiu; Suekane, Tetsuya; Song, Yongchen

    2017-04-01

    A clear understanding of two-phase fluid flow properties in porous media is of importance to CO2 geological storage. The study visually measured the immiscible and miscible displacement of water by CO2 using MRI (magnetic resonance imaging), and investigated the factor influencing the displacement process in porous media which were filled with quartz glass beads. For immiscible displacement at slow flow rates, the MR signal intensity of images increased because of CO2 dissolution; before the dissolution phenomenon became inconspicuous at flow rate of 0.8mLmin(-1). For miscible displacement, the MR signal intensity decreased gradually independent of flow rates, because supercritical CO2 and water became miscible in the beginning of CO2 injection. CO2 channeling or fingering phenomena were more obviously observed with lower permeable porous media. Capillary force decreases with increasing particle size, which would increase permeability and allow CO2 and water to invade into small pore spaces more easily. The study also showed CO2 flow patterns were dominated by dimensionless capillary number, changing from capillary finger to stable flow. The relative permeability curve was calculated using Brooks-Corey model, while the results showed the relative permeability of CO2 slightly decreases with the increase of capillary number.

  3. The Abundance of Atmospheric CO2 in Ocean Exoplanets: a Novel CO2 Deposition Mechanism

    Science.gov (United States)

    Levi, A.; Sasselov, D.; Podolak, M.

    2017-03-01

    We consider super-Earth sized planets which have a water mass fraction large enough to form an external mantle composed of high-pressure water-ice polymorphs and also lack a substantial H/He atmosphere. We consider such planets in their habitable zone, so that their outermost condensed mantle is a global, deep, liquid ocean. For these ocean planets, we investigate potential internal reservoirs of CO2, the amount of CO2 dissolved in the ocean for the various saturation conditions encountered, and the ocean-atmosphere exchange flux of CO2. We find that, in a steady state, the abundance of CO2 in the atmosphere has two possible states. When wind-driven circulation is the dominant CO2 exchange mechanism, an atmosphere of tens of bars of CO2 results, where the exact value depends on the subtropical ocean surface temperature and the deep ocean temperature. When sea-ice formation, acting on these planets as a CO2 deposition mechanism, is the dominant exchange mechanism, an atmosphere of a few bars of CO2 is established. The exact value depends on the subpolar surface temperature. Our results suggest the possibility of a negative feedback mechanism, unique to water planets, where a reduction in the subpolar temperature drives more CO2 into the atmosphere to increase the greenhouse effect.

  4. Metal-CO2 Batteries on the Road: CO2 from Contamination Gas to Energy Source.

    Science.gov (United States)

    Xie, Zhaojun; Zhang, Xin; Zhang, Zhang; Zhou, Zhen

    2017-01-20

    Rechargeable nonaqueous metal-air batteries attract much attention for their high theoretical energy density, especially in the last decade. However, most reported metal-air batteries are actually operated in a pure O2 atmosphere, while CO2 and moisture in ambient air can significantly impact the electrochemical performance of metal-O2 batteries. In the study of CO2 contamination on metal-O2 batteries, it has been gradually found that CO2 can be utilized as the reactant gas alone; namely, metal-CO2 batteries can work. On the other hand, investigations on CO2 fixation are in focus due to the potential threat of CO2 on global climate change, especially for its steadily increasing concentration in the atmosphere. The exploitation of CO2 in energy storage systems represents an alternative approach towards clean recycling and utilization of CO2 . Here, the aim is to provide a timely summary of recent achievements in metal-CO2 batteries, and inspire new ideas for new energy storage systems. Moreover, critical issues associated with reaction mechanisms and potential directions for future studies are discussed.

  5. 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.

  6. 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.

  7. The ATLAS IBL CO2 cooling system

    Science.gov (United States)

    Verlaat, B.; Ostrega, M.; Zwalinski, L.; Bortolin, C.; Vogt, S.; Godlewski, J.; Crespo-Lopez, O.; Van Overbeek, M.; Blaszcyk, T.

    2017-02-01

    The ATLAS Pixel detector has been equipped with an extra pixel layer in the space obtained by a smaller radius beam pipe. This new pixel layer called the Insertable B-Layer (IBL) was 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 (systems in High Energy Physics experiments. The cold temperatures are required to protect the pixel sensors for the expected high radiation dose received at an integrated luminosity of 550 fb1. 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.

  8. Upscaling of enzyme enhanced CO2 capture

    DEFF Research Database (Denmark)

    Gladis, Arne Berthold

    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...... promising mass transfer rate promoter for CCS. This process has been previously been tested successfully in lab scale and in some rare cases in pilot scale, but no validated process model for this technology has been published yet. This PhD thesis presents an investigation of the feasibility of enzyme...... enzyme kinetic model and validating it against in-house pilot plant experiments. The work consisted of identifying a suitable enzyme-solvent system and the ideal process conditions by comparing mass transfer rates of different solvents and enzyme enhanced solvents in a lab scale wetted wall column...

  9. 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...... monotonously. Such a variation is caused by scalar advection in the trunk space and reveals itself as a decrease or increase in vertical fluxes over the forest relative to carbon dioxide exchange of the underlying forest. The effect was more pronounced in model forests where the leaf area is concentrated...

  10. 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....

  11. CO2 sequestration in basalts: laboratory measurements

    Science.gov (United States)

    Otheim, L. T.; Adam, L.; van Wijk, K.; McLing, T. L.; Podgorney, R. K.

    2010-12-01

    Geologic sequestration of CO2 is proposed as the only promising large-scale method to help reduce CO2 gas emission by its capture at large point sources and subsequent long-term storage in deep geologic formations. Reliable and cost-effective monitoring will be important aspect of ensuring geological sequestration is a safe, effective, and acceptable method for CO2 emissions mitigation. Once CO2 injection starts, seismic methods can be used to monitor the migration of the carbon dioxide plume. To calibrate changes in rock properties from field observations, we propose to first analyze changes in elastic properties on basalt cores. Carbon dioxide sequestration in basalt rocks results in fluid substitution and mixing of CO2 with water and rock mineralizations. Carbon dioxide sequestration in mafic rocks creates reactions such as Mg2SiO 4 + CaMgSi2O 6 + 4CO2 = Mg 3Ca(CO 3) 4 + 3SiO2 whereby primary silicate minerals within the basalt react with carbonic acid laden water to creating secondary carbonate minerals and silicates. Using time-lapse laboratory scale experiments, such as laser generated ultrasonic wave propagation; it is possible to observe small changes in the physical properties of a rock. We will show velocity and modulus measurements on three basalt core samples for different saturation. The ultimate goal of the project is to track seismic changes due to fluid substitution and mineralization. The porosity of our basalts ranges from 8% to 12%, and the P-wave velocity increases by 20% to 40% from dry to water saturated conditions. Petrographic analysis (CT-scans, thin sections, XRF, XRf) will aid in the characterization of the mineral structure in these basalts and its correlation to seismic properties changes resulting from fluid substitution and mineralization.

  12. Local CO2-induced swelling of shales

    Science.gov (United States)

    Pluymakers, Anne; Dysthe, Dag Kristian

    2017-04-01

    In heterogeneous shale rocks, CO2 adsorbs more strongly to organic matter than to the other components. CO2-induced swelling of organic matter has been shown in coal, which is pure carbon. The heterogeneity of the shale matrix makes an interesting case study. Can local swelling through adsorption of CO2 to organic matter induce strain in the surrounding shale matrix? Can fractures close due to CO2-induced swelling of clays and organic matter? We have developed a new generation of microfluidic high pressure cells (up to 100 bar), which can be used to study flow and adsorption phenomena at the microscale in natural geo-materials. The devices contain one transparent side and a shale sample on the other side. The shale used is the Pomeranian shale, extracted from 4 km depth in Poland. This formation is a potential target of a combined CO2-storage and gas extraction project. To answer the first question, we place the pressure cell under a Veeco NT1100 Interferometer, operated in Vertical Scanning Interferometry mode and equipped with a Through Transmissive Media objective. This allows for observation of local swelling or organic matter with nanometer vertical resolution and micrometer lateral resolution. We expose the sample to CO2 atmospheres at different pressures. Comparison of the interferometry data and using SEM-EDS maps plus optical microscopy delivers local swelling maps where we can distinguish swelling of different mineralogies. Preliminary results indicate minor local swelling of organic matter, where the total amount is both time- and pressure-dependent.

  13. Local vascular CO2 reactivity in the infant brain assessed by functional MRI

    DEFF Research Database (Denmark)

    Toft, P.B.; Leth, H; Lou, H.C.

    1995-01-01

    hyperventilated voluntarily, the vascular reactivity was homogeneously distributed predominantly over the grey matter. The experiments demonstrate that local impairment of vascular CO2 reactivity in the distressed infant brain can be detected by T2 sensitive gradient-echo MRI, which is also known as functional...

  14. Do Tree Stems Recapture Respired CO2?

    Science.gov (United States)

    Hilman, B.; Angert, A.

    2016-12-01

    Tree stem respiration is an important, yet not well understood, component of the terrestrial carbon cycle. Predicting how trees as whole organisms respond to changes in climate and atmospheric CO2 requires understanding of the variability in the fraction of assimilated carbon allocated to respiration, versus the allocation to growth, damage repair, and to rhizosphere symbionts. Here we used the ratio of CO2 efflux/O2 influx (Apparent Respiratory Quotient, ARQ) to study stem respiration. The ARQ in trees stems is predicted to be 1.0, as a result of carbohydrates metabolism. Lower than 1.0 ARQ values may indicate a local assimilation of respired CO2, or dissolution and transport of CO2 in the xylem stream. We measured stems ARQ in 16 tree species at tropical, Mediterranean and temperate ecosystems using stem chambers and in-vitro incubations. The CO2 and O2 were measured by a system we developed, which is based on an IRGA and a Fuel-cell O2 analyzer (Hilman and Angert 2016). We found typical values of ARQ in the range of 0.4-0.8. Since incubations of detach stem tissues yielded similar ARQ values, and since the influence of natural variations in the transpiration stream on ARQ was found to be small, we conclude that the removal of the respired CO2 is not via dissolution in the xylem stream. Using 13C labeling, dark fixation of stem tissues was detected, which is most probably phosphoenolpyruvate carboxylase (PEPC) mediated. Hence, we suggest that in-stem dark fixation of respired CO2 to organic acids (e.g. malate) affects the outgoing efflux. Further research should determine if these organic acids are transported to the canopy, stored in the stem, or transported to the roots to serve as exudates. Hilman B, Angert A (2016) Measuring the ratio of CO2 efflux to O2 influx in tree stem respiration. Tree Physiol 2016, doi: 10.1093/treephys/tpw057

  15. 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...... concerns of the potential measures within those intervention areas: • Reductions in the need to travel • Improved efficiency of the transport system • Improved fuel efficiency of transport activities • Reduced CO2 intensity of the fuels Within each area a number of measures were analysed. The measures...

  16. 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

  17. 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...... perspectives for decreasing the heat requirement. However, a scientific understanding of the processes is required. The thermodynamic properties of the NH3–CO2–H2O system were described using the extended UNIQUAC electrolyte model developed by Thomsen and Rasmussen in a temperature range from 0 to 110°C...

  18. Leak Path Development in CO2 Wells

    Science.gov (United States)

    Torsater, M.; Todorovic, J.; Opedal, N.; Lavrov, A.

    2014-12-01

    Wells have in numerous scientific works been denoted the "weak link" of safe and cost-efficient CO2 Capture and Storage (CCS). Whether they are active or abandoned, all wells are man-made intrusions into the storage reservoir with sealing abilities depending on degradable materials like steel and cement. If dense CO2 is allowed to expand (e.g. due to leakage) it will cool down its surroundings and cause strong thermal and mechanical loading on the wellbore. In addition, CO2 reacts chemically with rock, cement and steel. To ensure long-term underground containment, it is therefore necessary to study how, why, where and when leakage occurs along CO2wells. If cement bonding to rock or casing is poor, leak paths can form already during drilling and completion of the well. In the present work, we have mapped the bonding quality of cement-rock and cement-steel interfaces - and measured their resistance towards CO2 flow. This involved a large experimental matrix including different rocks, steels, cement types and well fluids. The bonding qualities were measured on composite cores using micro computed tomography (µ-CT), and CO2 was flooded through the samples to determine leakage rates. These were further compared to numerical simulations of leakage through the digitalized µ-CT core data, and CO2chemical interactions with the materials were mapped using electron microscopy. We also present a new laboratory set-up for measuring how well integrity is affected by downhole temperature variations - and we showcase some initial results. Our work concludes that leak path development in CO2 wells depends critically on the drilling fluids and presflushes/spacers chosen already during drilling and completion of a well. Fluid films residing on rock and casing surfaces strongly degrade the quality of cement bonding. The operation of the well is also important, as even slight thermal cycling (between 10°C and 95°C on casing) leads to significant de-bonding of the annular cement.

  19. Toxic emissions and devaluated CO2-neutrality

    DEFF Research Database (Denmark)

    Czeskleba-Dupont, Rolf

    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...

  20. Carbon monoxide : A quantitative tracer for fossil fuel CO2?

    NARCIS (Netherlands)

    Gamnitzer, Ulrike; Karstens, Ute; Kromer, Bernd; Neubert, Rolf E. M.; Meijer, Harro A. J.; Schroeder, Hartwig; Levin, Ingeborg

    2006-01-01

    Carbon monoxide (CO), carbon dioxide (CO2), and radiocarbon ((CO2)-C-14) measurements have been made in Heidelberg from 2001 to 2004 in order to determine the regional fossil fuel CO2 component and to investigate the application of CO as a quantitative tracer for fossil fuel CO2 (CO2(foss)). The obs

  1. Multi-technique monitoring of CO2 leakage from an engineered CO2 leakage experiment

    Science.gov (United States)

    Zhou, X.; Apple, M. E.; Dobeck, L.; Cunningham, A. B.; Spangler, L.

    2012-12-01

    Monitoring of canopy and soil geophysical and geochemical properties in vadose zone by multiple techniques were carried out from 1999 to 2012 using an engineered CO2 release to simulate the CO2 leakage from CO2 storage at an agricultural plot at Bozeman, MT. The CO2 release was based on a horizontally-drilled well of 100 m at a depth of about 2.0-2.3m (Fig.1). Techniques utilized include hyperspectral and infrared radiation of various vegetations, electric conductivity in soil, magnetic field at the ground surface, and soil gas composition and dynamics using various gas sensors and soil moisture sensors. Measurements were made at several sites along a transect perpendicular to the releasing well, along which the soil CO2 concentration attenuated from high to normal condition at control site. The response of the canopy hyperspectral reflectance, infrared radiation, soil geophysical properties such as soil electric conductivity, top soil magnetic susceptibility and magnetic field, soil gas composition such as CO2 and O2 concentration to CO2 release at different rates were quantified and will be shown at this presentation. Fig.2 shows some examples of the results. The different responses at the impact and control sites are used to assess the effectiveness for CO2 surface and near-surface detection when a possible CO2 leakage occurs.ig.1. A schematic showing the injection and release of CO2 at an agricultral plot in Bozeman, MT. ig.2. Some examples of results showing the response of vegetation, hyperspectral reflectance, soil electric conductivity, soil O2 concentration to the release of CO2.

  2. 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 inferr

  3. 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 inferr

  4. The Abundance of Atmospheric CO2 in Ocean Exoplanets: A Novel CO2 Deposition Mechanism

    CERN Document Server

    Levi, Amit; Podolak, Morris

    2016-01-01

    We consider super-Earth sized planets which have a water mass fraction that is large enough to form an external mantle composed of high pressure water ice polymorphs and that lack a substantial H/He atmosphere. We consider such planets in their habitable zone so that their outermost condensed mantle is a global deep liquid ocean. For these ocean planets we investigate potential internal reservoirs of CO2; the amount of CO2 dissolved in the ocean for the various saturation conditions encountered, and the ocean-atmosphere exchange flux of CO2. We find that in steady state the abundance of CO2 in the atmosphere has two possible states. When the wind-driven circulation is the dominant CO2 exchange mechanism, an atmosphere of tens of bars of CO2 results, where the exact value depends on the subtropical ocean surface temperature and the deep ocean temperature. When sea-ice formation, acting on these planets as a CO2 deposition mechanism, is the dominant exchange mechanism, an atmosphere of a few bars of CO2 is esta...

  5. Experimental observation of permeability changes in dolomite at CO2 sequestration conditions.

    Science.gov (United States)

    Tutolo, Benjamin M; Luhmann, Andrew J; Kong, Xiang-Zhao; Saar, Martin O; Seyfried, William E

    2014-02-18

    Injection of cool CO2 into geothermally warm carbonate reservoirs for storage or geothermal energy production may lower near-well temperature and lead to mass transfer along flow paths leading away from the well. To investigate this process, a dolomite core was subjected to a 650 h, high pressure, CO2 saturated, flow-through experiment. Permeability increased from 10(-15.9) to 10(-15.2) m(2) over the initial 216 h at 21 °C, decreased to 10(-16.2) m(2) over 289 h at 50 °C, largely due to thermally driven CO2 exsolution, and reached a final value of 10(-16.4) m(2) after 145 h at 100 °C due to continued exsolution and the onset of dolomite precipitation. Theoretical calculations show that CO2 exsolution results in a maximum pore space CO2 saturation of 0.5, and steady state relative permeabilities of CO2 and water on the order of 0.0065 and 0.1, respectively. Post-experiment imagery reveals matrix dissolution at low temperatures, and subsequent filling-in of flow passages at elevated temperature. Geochemical calculations indicate that reservoir fluids subjected to a thermal gradient may exsolve and precipitate up to 200 cm(3) CO2 and 1.5 cm(3) dolomite per kg of water, respectively, resulting in substantial porosity and permeability redistribution.

  6. Direct measurements of air-sea CO2 exchange over a coral reef

    Science.gov (United States)

    McGowan, Hamish A.; MacKellar, Mellissa C.; Gray, Michael A.

    2016-05-01

    Quantification of CO2 exchange with the atmosphere over coral reefs has relied on microscale measurements of pCO2 gradients across the air-sea interfacial boundary; shipboard measurements of air-sea CO2 exchange over adjacent ocean inferred to represent over reef processes or ecosystem productivity modeling. Here we present by way of case study the first direct measurements of air-sea CO2 exchange over a coral reef made using the eddy covariance method. Research was conducted during the summer monsoon over a lagoonal platform reef in the southern Great Barrier Reef, Australia. Results show the reef flat to be a net source of CO2 to the atmosphere of similar magnitude as coastal lakes, while adjacent shallow and deep lagoons were net sinks as was the surrounding ocean. This heterogeneity in CO2 exchange with the atmosphere confirms need for spatially representative direct measurements of CO2 over coral reefs to accurately quantify their role in atmospheric carbon budgets.

  7. Projecting human development and CO2 emissions

    CERN Document Server

    Costa, Luís; Kropp, Jürgen P

    2012-01-01

    We estimate cumulative CO2 emissions during the period 2000 to 2050 from developed and developing countries based on the empirical relationship between CO2 per capita emissions (due to fossil fuel combustion and cement production) and corresponding HDI. In order to project per capita emissions of individual countries we make three assumptions which are detailed below. First, we use logistic regressions to fit and extrapolate the HDI on a country level as a function of time. This is mainly motivated by the fact that the HDI is bounded between 0 and 1 and that it decelerates as it approaches 1. Second, we employ for individual countries the correlations between CO2 per capita emissions and HDI in order to extrapolate their emissions. This is an ergodic assumption. Third, we let countries with incomplete data records evolve similarly as their close neighbors (in the emissions-HDI plane, see Fig. 1 in the main text) with complete time series of CO2 per capita emissions and HDI. Country-based emissions estimates a...

  8. The mechanical impact of CO2 injection

    NARCIS (Netherlands)

    Orlic, B.; Schroot, B.

    2005-01-01

    The mechanical impact of CO2 injection into a depleted hydrocarbon field or aquifer is caused by changes in the stress field, resulting from changes in the pore pressure and volume of the rock. Mechanical processes can lead to the loss of reservoir and caprock integrity, and the reactivation of exis

  9. 50 years of CO2 experience

    Energy Technology Data Exchange (ETDEWEB)

    Tyree, L. Jr [Liquid Carbonic Corp., PRAXAIR Inc., Kyongnam (Korea, Republic of)

    1998-12-31

    An overview is given of the experiences with the use of CO2 as a refrigerant at the Liquid Carbonic Corporation, now owned by PRAXAIR Inc. The overview is presented in the form of copies of overhead sheets, presented in Session 2 on Applications

  10. 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...

  11. Kosten en baten CO2-emissiereductie maatregelen

    NARCIS (Netherlands)

    Daniels, B.; Tieben, B.; Weda, J.; Hekkenberg, M.; Smekens, K.; Vethman, P.

    2012-01-01

    The Dutch Ministry of Infrastructure and the Environment has requested the Energy Research Centre of the Netherlands (ECN) and SEO Economic Research (SEO) to investigate the costs and benefits of a broad range of technical measures to realise CO2 emission reductions. The research aims to identify th

  12. Harvesting Energy from CO2 Emissions

    NARCIS (Netherlands)

    Hamelers, H.V.M.; Schaetzle, O.; Paz-García, J.M.; Biesheuvel, P.M.; Buisman, C.J.N.

    2014-01-01

    When two fluids with different compositions are mixed, mixing energy is released. This holds true for both liquids and gases, though in the case of gases, no technology is yet available to harvest this energy source. Mixing the CO2 in combustion gases with air represents a source of energy with a to

  13. CO2 laser used in cosmetology

    Science.gov (United States)

    Su, Chenglie

    1993-03-01

    Cases of various kinds of warts, nevi, papillomas, skin angiomas, ephilises, skin vegetation, scars and brandy noses were vaporized and solidified with a 2.5 - 8 W low power CO2 laser with an overall satisfaction rate up to 99.8% and the satisfaction rate for one time 92%.

  14. Warming the early Earth - CO2 reconsidered

    CERN Document Server

    Von Paris, P; Grenfell, L; Patzer, B; Hedelt, P; Stracke, B; Trautmann, T; Schreier, F

    2008-01-01

    Despite a fainter Sun, the surface of the early Earth was mostly ice-free. Proposed solutions to this so-called "faint young Sun problem" have usually involved higher amounts of greenhouse gases than present in the modern-day atmosphere. However, geological evidence seemed to indicate that the atmospheric CO2 concentrations during the Archaean and Proterozoic were far too low to keep the surface from freezing. With a radiative-convective model including new, updated thermal absorption coefficients, we found that the amount of CO2 necessary to obtain 273 K at the surface is reduced up to an order of magnitude compared to previous studies. For the late Archaean and early Proterozoic period of the Earth, we calculate that CO2 partial pressures of only about 2.9 mb are required to keep its surface from freezing which is compatible with the amount inferred from sediment studies. This conclusion was not significantly changed when we varied model parameters such as relative humidity or surface albedo, obtaining CO2 ...

  15. Agriculture waste and rising CO2

    Science.gov (United States)

    Currently, there are many uncertainties concerning agriculture’s role in global environmental change including the effects of rising atmospheric CO2 concentration. A viable and stable world food supply depends on productive agricultural systems, but environmental concerns within agriculture have to...

  16. 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.

  17. Sustainable Process Networks for CO2 Conversion

    DEFF Research Database (Denmark)

    Frauzem, Rebecca; Kongpanna, P.; Pavarajam, V.

    carbonate and ethylene carbonate are just some of the possible products that can be formed. Each of these involves CO2 and a co-reactant, such as hydrogen, which may also be captured from process purge streams. The process network evolves as some of the reactions involve products from other reactions...

  18. Economic optimization of CO2 pipeline configurations

    NARCIS (Netherlands)

    Knoope, M.M.J.; Ramirez, C.A.; Faaij, A.P.C.

    2013-01-01

    In this article, an economic optimization tool is developed taking into account different steel grades, inlet pressure, diameter and booster stations for point-to-point pipelines as well as for simple networks. Preliminary results show that gaseous CO2 transport is cost effective for relatively smal

  19. Cutting weeds with a CO2 laser

    DEFF Research Database (Denmark)

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

    2001-01-01

    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...

  20. Rhizosphere Responses to Elevated CO2

    NARCIS (Netherlands)

    Drigo, B.; Kowalchuk, G.A.; de Bruijn, F.J.

    2013-01-01

    Rising atmospheric CO2 levels are predicted to have major consequences on C cycling and the functioning of terrestrial ecosystems. Experimentation during the last two to three decades using a large variety of approaches have provided sufficient information to conclude that the enrichment of atmosphe

  1. 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

  2. CO2 dispersion modelling over Paris region within the CO2-MEGAPARIS project

    Directory of Open Access Journals (Sweden)

    L. Ammoura

    2012-10-01

    Full Text Available Accurate simulation of the spatial and temporal variability of tracer mixing ratios over urban areas is challenging, but essential in order to utilize CO2 measurements in an atmospheric inverse framework 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 between the surface and the atmosphere. Statistical scores show a good representation of the Urban Heat Island (UHI and urban-rural contrasts. Boundary layer heights (BLH at urban, sub-urban and rural sites are well captured, especially the onset time of the BLH increase and its growth rate in the morning, that are essential for tall tower CO2 observatories. Only nocturnal BLH at sub-urban sites are slightly underestimated a few nights, with a bias less than 50 m. At 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. The timing of the CO2 cycle is well captured by the model, with only small biases on CO2 concentrations, mainly linked to the misrepresentation of anthropogenic emissions, as the Eiffel site is at the heart of trafic emission sources. At sub-urban ground stations, CO2 measurements exhibit maxima at the beginning and at the end of each night, when the ABL is fully contracted, with a very strong spatio-temporal variability. The CO2 cycle at these sites is generally well reproduced by the model, even if some biases on the nocturnal maxima appear in the Paris plume parly due to small errors on the vertical

  3. CO2 adsorption isotherm on clay minerals and the CO2 accessibility into the clay interlayer

    Science.gov (United States)

    Gensterblum, Yves; Bertier, Pieter; Busch, Andreas; Rother, Gernot; Krooß, Bernhard

    2013-04-01

    Large-scale CO2 storage in porous rock formations at 1-3 km depth is seen as a global warming mitigation strategy. In this process, CO2 is separated from the flue gas of coal or gas power plants, compressed, and pumped into porous subsurface reservoirs with overlying caprocks (seals). Good seals are mechanically and chemically stable caprocks with low porosity and permeability. They prevent leakage of buoyant CO2 from the reservoir. Caprocks are generally comprised of thick layers of shale, and thus mainly consist of clay minerals. These clays can be affected by CO2-induced processes, such as swelling or dissolution. The interactions of CO2 with clay minerals in shales are at present poorly understood. Sorption measurements in combination scattering techniques could provide fundamental insight into the mechanisms governing CO2-clay interaction. Volumetric sorption techniques have assessed the sorption of supercritical CO2 onto coal (Gensterblum et al., 2010; Gensterblum et al., 2009), porous silica (Rother et al., 2012a) and clays as a means of exploring the potential of large-scale storage of anthropogenic CO2 in geological reservoirs (Busch et al., 2008). On different clay minerals and shales, positive values of excess sorption were measured at gas pressures up to 6 MPa, where the interfacial fluid is assumed to be denser than the bulk fluid. However, zero and negative values were obtained at higher densities, which suggests the adsorbed fluid becomes equal to and eventually less dense than the corresponding bulk fluid, or that the clay minerals expand on CO2 charging. Using a combination of neutron diffraction and excess sorption measurements, we recently deduced the interlayer density of scCO2 in Na-montmorillonite clay in its single-layer hydration state (Rother et al., 2012b), and confirmed its low density, as well as the expansion of the basal spacings. We performed neutron diffraction experiments at the FRMII diffractometer on smectite, kaolinite and illite

  4. CO2 dispersion modelling over Paris region within the CO2-MEGAPARIS project

    Science.gov (United States)

    Lac, C.; Donnelly, R. P.; Masson, V.; Pal, S.; Donier, S.; Queguiner, S.; Tanguy, G.; Ammoura, L.; Xueref-Remy, I.

    2012-10-01

    Accurate simulation of the spatial and temporal variability of tracer mixing ratios over urban areas is challenging, but essential in order to utilize CO2 measurements in an atmospheric inverse framework 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 between the surface and the atmosphere. Statistical scores show a good representation of the Urban Heat Island (UHI) and urban-rural contrasts. Boundary layer heights (BLH) at urban, sub-urban and rural sites are well captured, especially the onset time of the BLH increase and its growth rate in the morning, that are essential for tall tower CO2 observatories. Only nocturnal BLH at sub-urban sites are slightly underestimated a few nights, with a bias less than 50 m. At 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. The timing of the CO2 cycle is well captured by the model, with only small biases on CO2 concentrations, mainly linked to the misrepresentation of anthropogenic emissions, as the Eiffel site is at the heart of trafic emission sources. At sub-urban ground stations, CO2 measurements exhibit maxima at the beginning and at the end of each night, when the ABL is fully contracted, with a very strong spatio-temporal variability. The CO2 cycle at these sites is generally well reproduced by the model, even if some biases on the nocturnal maxima appear in the Paris plume parly due to small errors on the vertical transport, or in

  5. Effects of dissolved CO2 on Shallow Freshwater Microbial Communities simulating a CO2 Leakage Scenario

    Science.gov (United States)

    Gulliver, D. M.; Lowry, G. V.; Gregory, K.

    2013-12-01

    Geological carbon sequestration is likely to be part of a comprehensive strategy to minimize the atmospheric release of greenhouse gasses, establishing a concern of sequestered CO2 leakage into overlying potable aquifers. Leaking CO2 may affect existing biogeochemical processes and therefore water quality. There is a critical need to understand the evolution of CO2 exposed microbial communities that influence the biogeochemistry in these freshwater aquifers. The evolution of microbial ecology for different CO2 exposure concentrations was investigated using fluid-slurry samples obtained from a shallow freshwater aquifer (55 m depth, 0.5 MPa, 22 °C, Escatawpa, MS). The microbial community of well samples upstream and downstream of CO2 injection was characterized. In addition, batch vessel experiments were conducted with the upstream aquifer samples exposed to varying pCO2 from 0% to 100% under reservoir temperature and pressure for up to 56 days. The microbial community of the in situ experiment and the batch reactor experiment were analyzed with 16S rRNA clone libraries and qPCR. In both the in situ experiment and the batch reactor experiment, DNA concentration did not correlate with CO2 exposure. Both the in situ experiment and the batch reactors displayed a changing microbial community with increased CO2 exposure. The well water isolate, Curvibacter, appeared to be the most tolerant genus to high CO2 concentrations in the in situ experiments and to mid-CO2 concentrations in the batch reactors. In batch reactors with pCO2 concentrations higher than experienced in situ (pCO2 = 0.5 MPa), Pseudomonas appeared to be the most tolerant genus. Findings provide insight into a dynamic biogeochemical system that will alter with CO2 exposure. Adapted microbial populations will eventually give rise to the community that will impact the metal mobility and water quality. Knowledge of the surviving microbial populations will enable improved models for predicting the fate of CO2

  6. 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.

  7. Carbon Dioxide Laser Absorption Spectrometer (CO2LAS) Aircraft Measurements of CO2

    Science.gov (United States)

    Christensen, Lance E.; Spiers, Gary D.; Menzies, Robert T.; Jacob, Joseph C.; Hyon, Jason

    2011-01-01

    The Jet Propulsion Laboratory Carbon Dioxide Laser Absorption Spectrometer (CO2LAS) utilizes Integrated Path Differential Absorption (IPDA) at 2.05 microns to obtain CO2 column mixing ratios weighted heavily in the boundary layer. CO2LAS employs a coherent detection receiver and continuous-wave Th:Ho:YLF laser transmitters with output powers around 100 milliwatts. An offset frequency-locking scheme coupled to an absolute frequency reference enables the frequencies of the online and offline lasers to be held to within 200 kHz of desired values. We describe results from 2009 field campaigns when CO2LAS flew on the Twin Otter. We also describe spectroscopic studies aimed at uncovering potential biases in lidar CO2 retrievals at 2.05 microns.

  8. Extraction of lipids from microalgae using CO2-expanded methanol and liquid CO2.

    Science.gov (United States)

    Paudel, Ashok; Jessop, Michael J; Stubbins, Spencer H; Champagne, Pascale; Jessop, Philip G

    2015-05-01

    The use of CO2-expanded methanol (cxMeOH) and liquid carbon dioxide (lCO2) is proposed to extract lipids from Botryococcus braunii. When compressed CO2 dissolves in methanol, the solvent expands in volume, decreases in polarity and so increases in its selectivity for biodiesel desirable lipids. Solid phase extraction of the algal extract showed that the cxMeOH extracted 21 mg of biodiesel desirable lipids per mL of organic solvent compared to 3mg/mL using either neat methanol or chloroform/methanol mixture. The non-polar lCO2 showed a high affinity for non-polar lipids. Using lCO2, it is possible to extract up to 10% neutral lipids relative to the mass of dry algae. Unlike extractions using conventional solvents, these new methods require little to no volatile, flammable, or chlorinated organic solvents. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. A cross-association model for CO2-methanol and CO2-ethanol mixtures

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A cross-association model was proposed for CO2-alcohol mixtures based on the statistical associating fluid theory (SAFT).CO2 was treated as a pseudo-associating molecule and both the self-association between alcohol hydroxyls and the cross-association between CO2 and alcohol hydroxyls were considered.The equilibrium properties from low temperature-pressure to high temperature-pressure were investigated using this model.The calculated p-x and p-p diagrams of CO2-methanol and CO2-ethanol mixtures agreed with the experimental data.The results showed that when the cross-association was taken into account for Helmholtz free energy,the calculated equilibrium properties could be significantly improved,and the error prediction of the three phase equilibria and triple points in low temperature regions could be avoided.

  10. Carbonyl Sulfide: is it AN Isotope of CO2 on Steroids?

    Science.gov (United States)

    Berry, J. A.; Campbell, J. E.; Baker, I. T.; Whelan, M.; Hilton, T. W.

    2015-12-01

    The behavior of OCS in the atmosphere is very similar to that of CO2 and reminiscent of an isotopologue. It is stable, has a turnover time of a couple of years (similar to that of 18O in CO2). It can be measured with adequate accuracy - despite the fact that its abundance is one millionth that of CO2, but there is one dramatic difference. The seasonal variation in the concentration of OCS relative to its background concentration can be 6-10 fold larger than the corresponding variation in CO2 concentration. Furthermore there are large spatial gradients in atmospheric OCS, with the concentrations being generally lower over the continents than the ocean, and lower in the atmospheric boundary layer over vegetated surfaces than in the free troposphere. These gradients have been clearly resolved by flask sampling from aircraft and recently by satellite measurements. The dynamics of OCS are larger than any other conserved atmospheric gas and certainly dwarf isotopic gradients. There are strong differences in the kinetics of CO2 and OCS exchange with leaves (similar to an isotopic fractionation), but these are not responsible for the large atmospheric signals. The major driver of these gradients is a large spatial separation between the major sources of OCS (the tropical ocean) and the major sink (the terrestrial biosphere). This talk will review the biogeochemical cycle of OCS; the kinetics of its exchange with leaves and soils; the distribution of sources and sinks, and the local and large scale gradients of OCS concentration in the atmosphere.

  11. 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

  12. CO2 acquisition in Chlamydomonas acidophila is influenced mainly by CO2, not phosphorus, availability.

    Science.gov (United States)

    Spijkerman, Elly; Stojkovic, Slobodanka; Beardall, John

    2014-09-01

    The extremophilic green microalga Chlamydomonas acidophila grows in very acidic waters (pH 2.3-3.4), where CO2 is the sole inorganic carbon source. Previous work has revealed that the species can accumulate inorganic carbon (Ci) and exhibits high affinity CO2 utilization under low-CO2 (air-equilibrium) conditions, similar to organisms with an active CO2 concentrating mechanism (CCM), whereas both processes are down-regulated under high CO2 (4.5 % CO2) conditions. Responses of this species to phosphorus (Pi)-limited conditions suggested a contrasting regulation of the CCM characteristics. Therefore, we measured external carbonic anhydrase (CAext) activities and protein expression (CAH1), the internal pH, Ci accumulation, and CO2-utilization in cells adapted to high or low CO2 under Pi-replete and Pi-limited conditions. Results reveal that C. acidophila expressed CAext activity and expressed a protein cross-reacting with CAH1 (the CAext from Chlamydomonas reinhardtii). Although the function of this CA remains unclear, CAext activity and high affinity CO2 utilization were the highest under low CO2 conditions. C. acidophila accumulated Ci and expressed the CAH1 protein under all conditions tested, and C. reinhardtii also contained substantial amounts of CAH1 protein under Pi-limitation. In conclusion, Ci utilization is optimized in C. acidophila under ecologically relevant conditions, which may enable optimal survival in its extreme Ci- and Pi-limited habitat. The exact physiological and biochemical acclimation remains to be further studied.

  13. Sensitivity of simulated CO2 concentration to regridding of global fossil fuel CO2 emissions

    Directory of Open Access Journals (Sweden)

    X. Zhang

    2014-06-01

    Full Text Available Errors in the specification or utilization of fossil fuel CO2 emissions within carbon budget or atmospheric CO2 inverse studies can alias the estimation of biospheric and oceanic carbon exchange. A key component in the simulation of CO2 concentrations arising from fossil fuel emissions is the spatial distribution of the emission near coastlines. Finite grid resolution can give rise to mismatches between the emissions and simulated atmospheric dynamics which differ over land or water. We test these mismatches by examining simulated global atmospheric CO2 concentration driven by two different approaches to regridding fossil fuel CO2 emissions. The two approaches are: (1 a commonly-used method that allocates emissions to gridcells with no attempt to ensure dynamical consistency with atmospheric transport; (2 an improved method that reallocates emissions to gridcells to ensure dynamically consistent results. Results show large spatial and temporal differences in the simulated CO2 concentration when comparing these two approaches. The emissions difference ranges from −30.3 Tg C gridcell−1 yr−1 (−3.39 kg C m−2 yr−1 to +30.0 Tg C gridcell−1 yr−1 (+2.6 kg C m−2 yr−1 along coastal margins. Maximum simulated annual mean CO2 concentration differences at the surface exceed ±6 ppm at various locations and times. Examination of the current CO2 monitoring locations during the local afternoon, consistent with inversion modeling system sampling and measurement protocols, finds maximum hourly differences at 38 stations exceed ±0.10 ppm with individual station differences exceeding −32 ppm. The differences implied by not accounting for this dynamical consistency problem are largest at monitoring sites proximal to large coastal urban areas and point sources. These results suggest that studies comparing simulated to observed atmospheric CO2 concentration, such as atmospheric CO2 inversions, must take measures to correct for this potential

  14. Explaining Dutch emissions of CO2; a decomposition analysis

    OpenAIRE

    Alex Hoen; Machiel Mulder

    2003-01-01

    Decomposition of CO2 data of the Netherlands shows that much progress has been made with reduction of CO2 emissions by changing to less CO2 intensive technologies. Moreover, demand shifted to products that are produced with less CO2 emission. Further, shifts in the inputs needed in the production process also managed to decrease the CO2 emissions. These effects, however, were more than compensated by increased CO2 emission due to economic growth. Especially growth in exports led to substantia...

  15. Detection of CO2 leakage by the surface-soil CO2-concentration monitoring (SCM) system in a small scale CO2 release test

    Science.gov (United States)

    Chae, Gitak; Yu, Soonyoung; Sung, Ki-Sung; Choi, Byoung-Young; Park, Jinyoung; Han, Raehee; Kim, Jeong-Chan; Park, Kwon Gyu

    2015-04-01

    Monitoring of CO2 release through the ground surface is essential to testify the safety of CO2 storage projects. We conducted a feasibility study of the multi-channel surface-soil CO2-concentration monitoring (SCM) system as a soil CO2 monitoring tool with a small scale injection. In the system, chambers are attached onto the ground surface, and NDIR sensors installed in each chamber detect CO2 in soil gas released through the soil surface. Before injection, the background CO2 concentrations were measured. They showed the distinct diurnal variation, and were positively related with relative humidity, but negatively with temperature. The negative relation of CO2 measurements with temperature and the low CO2 concentrations during the day imply that CO2 depends on respiration. The daily variation of CO2 concentrations was damped with precipitation, which can be explained by dissolution of CO2 and gas release out of pores through the ground surface with recharge. For the injection test, 4.2 kg of CO2 was injected 1 m below the ground for about 30 minutes. In result, CO2 concentrations increased in all five chambers, which were located less than 2.5 m of distance from an injection point. The Chamber 1, which is closest to the injection point, showed the largest increase of CO2 concentrations; while Chamber 2, 3, and 4 showed the peak which is 2 times higher than the average of background CO2. The CO2 concentrations increased back after decreasing from the peak around 4 hours after the injection ended in Chamber 2, 4, and 5, which indicated that CO2 concentrations seem to be recovered to the background around 4 hours after the injection ended. To determine the leakage, the data in Chamber 2 and 5, which had low increase rates in the CO2 injection test, were used for statistical analysis. The result shows that the coefficient of variation (CV) of CO2 measurements for 30 minutes is efficient to determine a leakage signal, with reflecting the abnormal change in CO2

  16. 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

  17. CO2 dispersion modelling over Paris region within the CO2-MEGAPARIS project

    Science.gov (United States)

    Lac, C.; Donnelly, R. P.; Masson, V.; Pal, S.; Riette, S.; Donier, S.; Queguiner, S.; Tanguy, G.; Ammoura, L.; Xueref-Remy, I.

    2013-05-01

    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 sensitivity test without

  18. Conversion of organic carbon in the decomposable organic wastes in anaerobic lysimeters under different temperatures

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The quantitative fractions of conversion of organic carbon in the decomposable organic wastes with initial moisture of 70% sorted from municipal solid wastes(MSW) in lysimeters into biogas, leachate and solid residue were characterized, under temperatures of 25, 30 and 41℃, respectively, and circulation of leachate generated within the lysimeters. It is found that 27% of organic carbon in the wastes are conversed into gases, 0.8% into leachate, and the other 72% remained in the decomposable solid residues, after 180 days' degradation at 41℃. Higher temperature will lead to more rapid degradation and result to higher conversion of the organic carbon to biogas and lower to both solid residues and leachate, while the pollutant concentrations in leachate will be lower at a higher temperature and the values of COD are quite consistent with TOC.

  19. Design and construction of a large weighing lysimeter in an almond orchard

    Energy Technology Data Exchange (ETDEWEB)

    Lorite, I. J.; Santos, C.; Testi, L.; Fereres, E.

    2012-11-01

    Effective water management is essential to ensure the sustainability of irrigated agriculture. The accurate determination of crop water requirements is the first step in this task. This paper describes the building of a one-tree weighing lysimeter (3 × 3 m and 2.15 m depth) located in an almond (Prunus dulcis cv. Guara) orchard, inside the experimental farm “Alameda del Obispo” in Córdoba, Spain, to measure orchard evapotranspiration (ETc). Following a review on lysimetry, the description of the construction of the weighing lysimeter is provided in detail, including considerations relative to system resolution and wind effects on the measurements. Finally, some preliminary results of the evaporation and transpiration of young almond trees are presented demonstrating that lysimetry in orchards provides accurate ETc values needed to determine irrigation water requirements. (Author) 72 refs.

  20. CO2-helium and CO2-neon mixtures at high pressures.

    Science.gov (United States)

    Mallick, B; Ninet, S; Le Marchand, G; Munsch, P; Datchi, F

    2013-01-28

    The properties of mixtures of carbon dioxide with helium or neon have been investigated as a function of CO(2) concentration and pressure up to 30 GPa at room temperature. The binary phase diagrams of these mixtures are determined over the full range of CO(2) concentrations using visual observations and Raman scattering measurements. Both diagrams are of eutectic type, with a fluid-fluid miscibility gap for CO(2) concentrations in the range [5, 75] mol. % for He and [8, 55] mol. % for Ne, and a complete separation between the two components in the solid phase. The absence of alloys or stoichiometric compounds for these two binary systems is consistent with the Hume-Rothery rules of hard sphere mixtures. The Raman spectra and x-ray diffraction patterns of solid CO(2) embedded in He or Ne for various initial concentrations have been measured up to 30 GPa and 12 GPa, respectively. The frequencies of the Raman modes and the volume of solid phase I are identical, within error bars, to those reported for 100% CO(2) samples, thus confirming the total immiscibility of CO(2) with He and Ne in the solid phase. These results demonstrate the possibility to perform high-pressure experiments on solid CO(2) under (quasi-)hydrostatic conditions using He or Ne as pressure transmitting medium.

  1. On using radon-222 and CO2 to calculate regional-scale CO2 fluxes

    Directory of Open Access Journals (Sweden)

    A. I. Hirsch

    2006-11-01

    Full Text Available Because of its ubiquitous release on land and well-characterized atmospheric loss, radon-222 has been very useful for deducing fluxes of greenhouse gases such as CO2, CH4, and N2O. It is shown here that the radon-tracer method, used in previous studies to calculate regional-scale greenhouse gas fluxes, returns a weighted-average flux (the flux field F weighted by the sensitivity of the measurements to that flux field, f rather than an evenly-weighted spatial average flux. A synthetic data study using a Lagrangian particle dispersion model and modeled CO2 fluxes suggests that the discrepancy between the sensitivity-weighted average flux and evenly-weighted spatial average flux can be significant in the case of CO2, due to covariance between F and f for biospheric CO2 fluxes during the growing season and also for anthropogenic CO2 fluxes in general. A technique is presented to correct the radon-tracer derived fluxes to yield an estimate of evenly-weighted spatial average CO2 fluxes. A new method is also introduced for correcting the CO2 flux estimates for the effects of radon-222 radioactive decay in the radon-tracer method.

  2. On using radon-222 and CO2 to calculate regional-scale CO2 fluxes

    Directory of Open Access Journals (Sweden)

    A. I. Hirsch

    2007-07-01

    Full Text Available Because of its ubiquitous release on land and well-characterized atmospheric loss, radon-222 has been very useful for deducing fluxes of greenhouse gases such as CO2, CH4, and N2O. It is shown here that the radon-tracer method, used in previous studies to calculate regional-scale greenhouse gas fluxes, returns a weighted-average flux (the flux field F weighted by the sensitivity of the measurements to that flux field, f rather than an evenly-weighted spatial average flux. A synthetic data study using a Lagrangian particle dispersion model and modeled CO2 fluxes suggests that the discrepancy between the sensitivity-weighted average flux and evenly-weighted spatial average flux can be significant in the case of CO2, due to covariance between F and f for biospheric CO2 fluxes during the growing season and also for anthropogenic CO2 fluxes in general. A technique is presented to correct the radon-tracer derived fluxes to yield an estimate of evenly-weighted spatial average CO2 fluxes. A new method is also introduced for correcting the CO2 flux estimates for the effects of radon-222 radioactive decay in the radon-tracer method.

  3. CO2驱油与埋存研究进展%Advances in CO2 Displacing Oil and CO2 Sequestrated Researches

    Institute of Scientific and Technical Information of China (English)

    陈欢庆; 胡永乐; 田昌炳

    2012-01-01

    The current situation of CO2 displacing oil and CO2 sequestrated researches was reviewed. Nowadays, CO2 displacing oil had got good economic benefits outside and was carried out oil field experiment inside. And CO2 sequestrated researches were in exploring stage all over the world. The key problems in CO2 displacing oil and CO2 sequestrated researches contained five parts, such as enlarging sweep volume of EOR, carrier and medium choice of CO2 sequestrated, the formation damage in the process of CO2 displacing oil, air source, industrial coordination and overall planning. Finally, several development directions of CO2 displacing oil and CO2 sequestrated researches were proposed.%详细介绍了CO2驱油与埋存研究的现状。目前CO2驱油在国外已取得较好的经济效益,在国内正在进行矿场先导试验。而CO2埋存在国内外均处于探索阶段。CO2驱油与埋存研究中存在的问题主要包括提高采收率方面的扩大波及体积等关键问题、CO2埋存介质和方法的选择、CO2驱油对地层的伤害、CO2驱油与埋存的气源问题、CO2驱油与埋存产业协调和整体规划5大方面。指出了该项研究的发展趋势。图2表2参38

  4. 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.

  5. Global CO2 fluxes estimated from GOSAT retrievals of total column CO2

    Directory of Open Access Journals (Sweden)

    M. Torn

    2013-02-01

    Full Text Available We present one of the first estimates of the global distribution of CO2 surface fluxes using total column CO2 measurements retrieved 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.

  6. The Relationship Between CO2 Levels and CO2 Related Symptoms Reported on the ISS

    Science.gov (United States)

    VanBaalen, M.; Law, J.; Foy, M.; Wear, M. L.; Mason, S.; Mendez, C.; Meyers, V.

    2014-01-01

    Medical Operations, Toxicology, and the Lifetime Surveillance of Astronaut Health collaborated to assess the association of CO2 levels on board the International Space Station and USOS crew reported symptoms inflight, i.e. headache and vision changes. Private Medical Conference (PMC) documents and the weekly Space Medicine Operations Team (SMOT) Notes were used to provide a robust data set of inflight medical events. All events and non-events were documented independent of CO2 levels and other potential contributors. Average (arithmetic mean) and single point maximum ppCO2 was calculated for the 24 hours and 7 days prior to the PMC or SMOT date and time provided by LSAH. Observations falling within the first 7 days of flight (147) were removed from the datasets analyzed to avoid confounding with Space Adaptation Syndrome. The final analysis was based on 1716 observations. For headache, 46 headaches were observed. CO2 level, age at launch, time inflight, and data source were all significantly associated with headache. In particular, for each 1 mmHg increase in CO2, the odds of a crewmember reporting a headache doubled. For vision changes, 29 reports of vision changes were observed. These observations were not found to be statistically associated with CO2 levels as analyzed. While the incidence of headache has was not high (3%), headaches may be an indicator of underlying increases in intracranial pressure, which may result likely from the synergy between CO2-induced cerebral vasodilatation and decreased venous drainage in microgravity. Vision changes were inconsistently reported and as a result did not align appropriately with the CO2 levels. Further analysis is needed. Our results support ongoing efforts to lower the CO2 exposure limits in spacecraft.

  7. Evaluation of water movement and nitrate dynamics in a lysimeter planted with an orange tree

    OpenAIRE

    Phogat, V; Skewes, MA; Cox, JW; Alam, J; Grigson, G; J. Šimůnek

    2013-01-01

    Adoption of high input irrigation management systems for South Australian horticultural crops seeks to provide greater control over timing of irrigation and fertilizer applications. The HYDRUS 2D/3D model was used to simulate water movement in the soil under an orange tree planted in a field lysimeter supplied with 68.6mm of irrigation water over 29 days. Simulated volumetric water contents statistically matched those measured using a capacitance soil water probe. Statistical measures (MAE, R...

  8. Design and construction of a large weighing lysimeter in an almond orchard

    OpenAIRE

    2012-01-01

    Effective water management is essential to ensure the sustainability of irrigated agriculture. The accurate determination of crop water requirements is the first step in this task. This paper describes the building of a one-tree weighing lysimeter (3 × 3 m and 2.15 m depth) located in an almond (Prunus dulcis cv. Guara) orchard, inside the experimental farm "Alameda del Obispo" in Córdoba, Spain, to measure orchard evapotranspiration (ET c). Following a review on lysimetry, the description of...

  9. Closing the Water Balance for Arid Soils - First Results from a Large Lysimeter Study

    Science.gov (United States)

    Twarakavi, N.; Chief, K.; Berli, M.; Caldwell, T. G.; Daniels, J.; Young, M.

    2011-12-01

    Many ecological and hydrological processes cannot be fully assessed without full closure of the water balance. The weighing lysimeter facility in Boulder City, NV provides an excellent opportunity to study water infiltration, redistribution, storage and evaporation of bare soils at the intermediate (meter) scale under well-defined boundary conditions. Each of three lysimeters is weighed on separate balances, with a resolution of roughly 100 g or 0.025 mm of water. Each lysimeter contains 12 m3 of repacked homogenized and layered desert soil (dimensions: 2.26 m diameter and 3 m deep) and is instrumented with 13 different sensor technologies to measure state variables including water content, matric potential, and thermal properties at 15 depth planes. An angled rhizotron tube visually monitors movement the infiltration front. Between July 2008 and 2011, 15 storm events were recorded, with the largest storm total from 19-22 December 2010 yielding 62 mm of precipitation (originally in the form of snow). By July 2011, nearly 350 mm of cumulative precipitation was recorded, and the wetting front had reached 150 cm depth. This presentation analyzes storm events over the past three years with respect to changes in total soil mass to determine the amount of infiltration, storage, and evaporation; alterations in soil moisture and matric potential profiles determined by in situ sensors; and wetting front movement observed by the rhizotron. This lysimeter facility fills a critical gap in the vadose zone hydrology of arid environments by closing the total water balance and providing discrete data on soil moisture redistribution in a 3 meter deep soil profile to evaluate and improve infiltration models.

  10. CO2 capture processes in power plants - Le captage du CO2 dans les centrales thermiques

    OpenAIRE

    Bouallou, Chakib

    2010-01-01

    PDF file available for free at http://pubs.ub.ro/?pg=revues&rev=cscc6&num=201011&vol=1&aid=2975; International audience; This review is devoted to assess and compare various processes aiming at recover CO2 from power plants fed with natural gas (NGCC) and pulverized coal (PC). These processes are post combustion CO2 capture using chemical solvents, natural gas reforming for pre-combustion capture and oxy-fuel combustion with cryogenic recovery of CO2. These processes were evaluated to give so...

  11. CO2 mineralization-bridge between storage and utilization of CO2.

    Science.gov (United States)

    Geerlings, Hans; Zevenhoven, Ron

    2013-01-01

    CO2 mineralization comprises a chemical reaction between suitable minerals and the greenhouse gas carbon dioxide. The CO2 is effectively sequestered as a carbonate, which is stable on geological timescales. In addition, the variety of materials that can be produced through mineralization could find applications in the marketplace, which makes implementation of the technology more attractive. In this article, we review recent developments and assess the current status of the CO2 mineralization field. In an outlook, we briefly describe a few mineralization routes, which upon further development have the potential to be implemented on a large scale.

  12. Importance of Non-Diffusive Transport for Soil CO2 Efflux in a Temperate Mountain Grassland

    Science.gov (United States)

    Roland, Marilyn; Vicca, Sara; Bahn, Michael; Ladreiter-Knauss, Thomas; Schmitt, Michael; Janssens, Ivan A.

    2015-04-01

    A key focus in climate change is on the dynamics and predictions of the soil CO2 efflux (SCE) from terrestrial ecosystems. Limited knowledge of CO2 transport through the soil restricts our understanding of the various biotic and abiotic processes underlying these emissions. Diffusion is often thought to be the main transport mechanism for trace gases in soils, an assumption that is reflected in the increasing popularity of the flux-gradient approach (FGA). Based on Fick's law, the FGA calculates soil CO2 efflux from CO2 concentration profiles, given good estimates of the diffusion coefficient. The latter can be calculated via different commonly used models, and solid-state sensors allow continuous high-frequency measurements of soil CO2 concentrations with minimal disturbance to the soil conditions in a cost-effective way. Fast growing evidence of pressure pumping and advection, makes it impossible to disregard non-diffusive gas transport when evaluating diel and day-to-day dynamics of soil CO2 emissions. We have analyzed combined measurements from solid-state sensors and soil chambers to gain insight in the CO2 transport mechanisms in a grassland site in the Austrian Alps. The FGA-derived efflux underestimated the chamber efflux by 10 to 87% at our site, depending on which model was used for calculation of the diffusion coefficient. We found that the actual transport rates correlated well with irradiation and wind speed, even more when the soil moisture content was below 33%. These findings suggest that bulk soil air transport was enhanced by pressure changes induced by wind shear at the surface and by local heating of the soil surface. Considering the importance of non-diffusive transport processes is a prerequisite when using solid-state CO2 concentration measurements to estimate soil CO2 efflux at any given site.

  13. Advances in Pulsed Lidar Measurements of CO2 Column Concentrations from Aircraft and for Space

    Science.gov (United States)

    Abshire, J. B.; Ramanathan, A. K.; Allan, G. R.; Hasselbrack, W. E.; Riris, H.; Numata, K.; Mao, J.; Sun, X.

    2016-12-01

    We have demonstrated an improved pulsed, multiple-wavelength integrated path differential absorption lidar for measuring the tropospheric CO2 concentrations. The lidar measures the range resolved shape of the 1572.33 nm CO2 absorption line to scattering surfaces, including the ground and the tops of clouds. Airborne measurements have used both 30 and 15 fixed wavelength samples distributed across the line. Analysis estimates the lidar range and pulse energies at each wavelength 10 times per second. The retrievals solve for the CO2 absorption line shape and the column average CO2 concentrations by using radiative transfer calculations, the aircraft altitude and range to the scattering surface, and the atmospheric conditions. We compare these to CO2 concentrations from in-situ sensors. In recent campaigns the lidar used a step-locked laser diode source, and a new HgCdTe APD detector in the receiver. During August and September 2014 the ASCENDS campaign flew over the California Central Valley, a coastal redwood forest, desert areas, and above growing crops in Iowa. Analyses show the retrievals of lidar range and CO2 column absorption, and mixing ratio worked well when measuring over variable topography and through thin clouds and aerosols. The retrievals clearly show the decrease in CO2 concentration over growing cropland. Airborne lidar measurements of horizontal gradients of CO2 concentrations across Nevada, Colorado and Nebraska showed good agreement with those from a model of CO2 flux and transport (PCTM). In several flights the agreement of the lidar with the column average concentration was ppm, with standard deviation of 0.9 ppm. Two additional flights were made in February 2016 using a larger laser spot size and an optimized receiver. These improved the sensitivity x3, and the retrievals show 0.7 ppm precision over the desert in 1 second averaging time. A summary of these results will be presented, along with on-going developments for a space version.

  14. Mechanisms for synoptic variations of atmospheric CO2 in North America, South America and Europe

    Directory of Open Access Journals (Sweden)

    I. T. Baker

    2008-12-01

    Full Text Available Synoptic variations of atmospheric CO2 produced by interactions between weather and surface fluxes are investigated mechanistically and quantitatively in midlatitude and tropical regions using continuous in-situ CO2 observations in North America, South America and Europe and forward chemical transport model simulations with the Parameterized Chemistry Transport Model. Frontal CO2 climatologies show consistently strong, characteristic frontal CO2 signals throughout the midlatitudes of North America and Europe. Transitions between synoptically identifiable CO2 air masses or transient spikes along the frontal boundary typically characterize these signals. One case study of a summer cold front shows CO2 gradients organizing with deformational flow along weather fronts, producing strong and spatially coherent variations. In order to differentiate physical and biological controls on synoptic variations in midlatitudes and a site in Amazonia, a boundary layer budget equation is constructed to break down boundary layer CO2 tendencies into components driven by advection, moist convection, and surface fluxes. This analysis suggests that, in midlatitudes, advection is dominant throughout the year and responsible for 60–70% of day-to-day variations on average, with moist convection contributing less than 5%. At a site in Amazonia, vertical mixing, in particular coupling between convective transport and surface CO2 flux, is most important, with advection responsible for 26% of variations, moist convection 32% and surface flux 42%. Transport model sensitivity experiments agree with budget analysis. These results imply the existence of a recharge-discharge mechanism in Amazonia important for controlling synoptic variations of boundary layer CO2, and that forward and inverse simulations should take care to represent moist convective transport. Due to the scarcity of tropical observations at the time of this study, results in Amazonia are not generalized for

  15. Towards an unbiased filter routine to determine precipitation and evapotranspiration from high precision lysimeter measurements

    Science.gov (United States)

    Peters, Andre; Groh, Jannis; Schrader, Frederik; Durner, Wolfgang; Vereecken, Harry; Pütz, Thomas

    2017-06-01

    Weighing lysimeters are considered to be the best means for a precise measurement of water fluxes at the interface between the soil-plant system and the atmosphere. Any decrease of the net mass of the lysimeter can be interpreted as evapotranspiration (ET), any increase as precipitation (P). However, the measured raw data need to be filtered to separate real mass changes from noise. Such filter routines typically apply two steps: (i) a low pass filter, like moving average, which smooths noisy data, and (ii) a threshold filter that separates significant from insignificant mass changes. Recent developments of these filters have identified and solved some problems regarding bias in the data processing. A remaining problem is that each change in flow direction is accompanied with a systematic flow underestimation due to the threshold scheme. In this contribution, we analyze this systematic effect and show that the absolute underestimation is independent of the magnitude of a flux event. Thus, for small events, like dew or rime formation, the relative error is high and can reach the same magnitude as the flux itself. We develop a heuristic solution to the problem by introducing a so-called ;snap routine;. The routine is calibrated and tested with synthetic flux data and applied to real measurements obtained with a precision lysimeter for a 10-month period. The heuristic snap routine effectively overcomes these problems and yields an almost unbiased representation of the real signal.

  16. Automated Passive Capillary Lysimeters for Estimating Water Drainage in the Vadose Zone

    Science.gov (United States)

    Jabro, J.; Evans, R.

    2009-04-01

    In this study, we demonstrated and evaluated the performance and accuracy of an automated PCAP lysimeters that we designed for in-situ continuous measuring and estimating of drainage water below the rootzone of a sugarbeet-potato-barley rotation under two irrigation frequencies. Twelve automated PCAPs with sampling surface dimensions of 31 cm width * 91 cm long and 87 cm in height were placed 90 cm below the soil surface in a Lihen sandy loam. Our state-of-the-art design incorporated Bluetooth wireless technology to enable an automated datalogger to transmit drainage water data simultaneously every 15 minutes to a remote host and had a greater efficiency than other types of lysimeters. It also offered a significantly larger coverage area (2700 cm2) than similarly designed vadose zone lysimeters. The cumulative manually extracted drainage water was compared with the cumulative volume of drainage water recorded by the datalogger from the tipping bucket using several statistical methods. Our results indicated that our automated PCAPs are accurate and provided convenient means for estimating water drainage in the vadose zone without the need for costly and manually time-consuming supportive systems.

  17. Dynamic breathing of CO2 by hydrotalcite.

    Science.gov (United States)

    Ishihara, Shinsuke; Sahoo, Pathik; Deguchi, Kenzo; Ohki, Shinobu; Tansho, Masataka; Shimizu, Tadashi; Labuta, Jan; Hill, Jonathan P; Ariga, Katsuhiko; Watanabe, Ken; Yamauchi, Yusuke; Suehara, Shigeru; Iyi, Nobuo

    2013-12-04

    The carbon cycle of carbonate solids (e.g., limestone) involves weathering and metamorphic events, which usually occur over millions of years. Here we show that carbonate anion intercalated layered double hydroxide (LDH), a class of hydrotalcite, undergoes an ultrarapid carbon cycle with uptake of atmospheric CO2 under ambient conditions. The use of (13)C-labeling enabled monitoring by IR spectroscopy of the dynamic exchange between initially intercalated (13)C-labeled carbonate anions and carbonate anions derived from atmospheric CO2. Exchange is promoted by conditions of low humidity with a half-life of exchange of ~24 h. Since hydrotalcite-like clay minerals exist in Nature, our finding implies that the global carbon cycle involving exchange between lithosphere and atmosphere is much more dynamic than previously thought.

  18. Thermodynamic modeling of CO2 mixtures

    DEFF Research Database (Denmark)

    Bjørner, Martin Gamel

    performed satisfactorily and predicted the general behavior of the systems, but qCPA used fewer adjustable parameters to achieve similar predictions. It has been demonstrated that qCPA is a promising model which, compared to CPA, systematically improves the predictions of the experimentally determined phase......, accurate predictions of the thermodynamic properties and phase equilibria of mixtures containing CO2 are challenging with classical models such as the Soave-Redlich-Kwong (SRK) equation of state (EoS). This is believed to be due to the fact, that CO2 has a large quadrupole moment which the classical models...... do not explicitly account for. In this thesis, in an attempt to obtain a physically more consistent model, the cubicplus association (CPA) EoS is extended to include quadrupolar interactions. The new quadrupolar CPA (qCPA) can be used with the experimental value of the quadrupolemoment...

  19. Streamer parameters and breakdown in CO2

    Science.gov (United States)

    Seeger, M.; Avaheden, J.; Pancheshnyi, S.; Votteler, T.

    2017-01-01

    CO2 is a promising gas for the replacement of SF6 in high-voltage transmission and distribution networks due to its lower environmental impact. The insulation properties of CO2 are, therefore, of great interest. For this, the properties of streamers are important, since they determine the initial discharge propagation and possibly the transition to a leader. The present experimental investigation addresses the streamer inception and propagation at ambient temperature in the pressure range 0.05-0.5 MPa at both polarities. Streamer parameters, namely the stability field, radius and velocity, were deduced in uniform and in strongly non-uniform background fields. The measured breakdown fields can then be understood by streamer propagation and streamer-to-leader transition.

  20. CO2 Impacts on the Martian Atmosphere

    Science.gov (United States)

    Kelley, Michael; Bauer, James; Bodewits, Dennis; Farnham, Tony; Stevenson, Rachel; Yelle, Roger

    2014-09-01

    The dynamically new comet C/2013 A1 (Siding Spring) will pass Mars at the extremely close distance of 140,000 km on 2014 Oct 19. This encounter is unique---a record close approach to a planet with spacecraft that can observe its passage---and currently, all 5 Mars orbiters have plans to observe the comet and/or its effects on the planet. Gas from the comet's coma is expected to collide with the Martian atmosphere, altering the abundances of some species and producing significant heating, inflating the upper atmosphere. We propose DDT observations with Spitzer/IRAC to measure the comet's CO2+CO coma (observing window Oct 30 - Nov 20), to use these measurements to derive the coma's CO2 density at Mars during the closest approach, and to aid the interpretation of any observed effects or changes in the Martian atmosphere.

  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. 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

  3. CO2 enhanced oil recovery economics

    Energy Technology Data Exchange (ETDEWEB)

    Bloomquist, C.W.

    1983-01-01

    Realistic estimates of potential enhanced oil recovery (EOR) reserve additions range from 15 to 50 billion bbl. Oil price, technical advancements, and taxation will strongly influence how much of this potential can be realized. EOR can be implemented on a large scale in the near term, and can contribute significantly to domestic oil production by the late 1980s. The contribution of CO2 injection recovery processes to this enhancement of oil reserves is examined with regard to economics and technology.

  4. Inbound Logistics Cost and CO2 Calculations

    OpenAIRE

    Kökler, Cihan

    2010-01-01

    Business has globalized rapidly during the last decades. Distances between point of origin and point of consumption have increased as a result of globalization. Today’s increased distances mean that companies require faster logistic responses. Air transportation is preferred because it’s worldwide lead-time, of just 1-2 day, fulfill business expectations. However, transportation operation costs have risen dramatically and there are growing concerns about the high CO2 emission levels associate...

  5. Pulpotomies with CO2 laser in dogs

    Science.gov (United States)

    Figueiredo, Jose A. P.; Chavantes, Maria C.; Gioso, Marco A.; Pesce, Hildeberto F.; Jatene, Adib D.

    1995-05-01

    The aim of this study was to evaluate the clinical aspects of dental pulps submitted to shallow pulpotomy followed by CO2 laser radiation at five different procedures. For this purpose, initially 66 dogs' teeth were opened and about 2 or 3 mm of coronal dental pulp was removed. Continuous irrigation with saline solution was implemented. The teeth were randomly divided into 6 groups of 11 each. After cessation of bleeding, in group I, CO2 laser (Xanar-20, USA) was irradiated for 1 second at a power of 5 watts; in group II, 2 seconds at 3 watts; in Group III, 2 seconds at 5 watts; in Group IV, 1 second at 3 watts; in Group V, a continuous mode at 3 watts; Group VI served as a control, with no laser irradiation. The results showed no clinical differences between the 3 W and 5 W powers. Time period of irradiation exposition influenced definitively the clinical appearance of the dental pulps. Groups I and IV (1 second) were unable to stop the bleeding, which persisted over 15 minutes for all teeth. This may be due to the intense heat generated by CO2 laser, causing vasodilatation. Groups II and III displayed a similar appearance, but bleeding stopped in about 10 minutes. Group V (continuous mode) had no bleeding after irradiation, but a plasma-like liquid would come out for almost 2 minutes. When comparing to the control (Group VI), all the pulps would assume a jelly-like aspect, with black granulated tissue on the surface, covering totally the pulps of Group V and partially the other groups. The histological results will be discussed in a further study. From the data obtained, it seems that CO2 laser irradiation for pulpotomies should be done in a continuous mode, for clinical convenience in terms of time taken and effective irradiation.

  6. Effects of copper vapour on thermophysical properties of CO2-N2 plasma

    Science.gov (United States)

    Zhong, Linlin; Wang, Xiaohua; Rong, Mingzhe; Cressault, Yann

    2016-10-01

    CO2-N2 mixtures are often used as arc quenching medium (to replace SF6) in circuit breakers and shielding gas in arc welding. In such applications, copper vapour resulting from electrode surfaces can modify characteristics of plasmas. This paper therefore presents an investigation of the effects of copper on thermophysical properties of CO2-N2 plasma. The equilibrium compositions, thermodynamic properties (including mass density, specific enthalpy, and specific heat), transport coefficients (including electrical conductivity, viscosity, and thermal conductivity), and four kinds of combined diffusion coefficients due to composition gradients, applied electric fields, temperature gradients, and pressure gradients respectively, were calculated and discussed for CO2-N2 (mixing ratio 7:3) plasma contaminated by different proportions of copper vapour. The significant influences of copper were observed on all the properties of CO2-N2-Cu mixtures. The better ionization ability and larger molar mass of copper and larger collision integrals related to copper, should be responsible for such influences.

  7. Change in cap rock porosity triggered by pressure and temperature dependent CO2–water–rock interactions in CO2 storage systems

    Directory of Open Access Journals (Sweden)

    Christina Hemme

    2017-03-01

    Full Text Available Carbon capture and storage in deep geological formations is a method to reduce greenhouse gas emissions. Supercritical CO2 is injected into a reservoir and dissolves in the brine. Under the impact of pressure and temperature (P–T the aqueous species of the CO2-acidified brine diffuse through the cap rock where they trigger CO2–water–rock interactions. These geochemical reactions result in mineral dissolution and precipitation along the CO2 migration path and are responsible for a change in porosity and therefore for the sealing capacity of the cap rock. This study focuses on the diffusive mass transport of CO2 along a gradient of decreasing P–T conditions. The process is retraced with a one-dimensional hydrogeochemical reactive mass transport model. The semi-generic hydrogeochemical model is based on chemical equilibrium thermodynamics. Based on a broad variety of scenarios, including different initial mineralogical, chemical and physical parameters, the hydrogeochemical parameters that are most sensitive for safe long-term CO2 storage are identified. The results demonstrate that P–T conditions have the strongest effect on the change in porosity and the effect of both is stronger at high P–T conditions because the solubility of the mineral phases involved depends on P–T conditions. Furthermore, modeling results indicate that the change in porosity depends strongly on the initial mineralogical composition of the reservoir and cap rock as well as on the brine compositions. Nevertheless, a wide range of conditions for safe CO2 storage is identified.

  8. CO2 cooling for HEP experiments

    CERN Document Server

    Verlaat; Van Lysebetten, A

    2008-01-01

    The new generation silicon detectors require more efficient cooling of the front-end electronics and the silicon sensors themselves. To minimize reverse annealing of the silicon sensors the cooling temperatures need to be reduced. Other important requirements of the new generation cooling systems are a reduced mass and a maintenance free operation of the hardware inside the detector. Evaporative CO2 cooling systems are ideal for this purpose as they need smaller tubes than conventional systems. The heat transfer capability of evaporative CO2 is high. CO2 is used as cooling fluid for the LHCb-VELO and the AMS-Tracker cooling systems. A special method for the fluid circulation is developed at Nikhef to get a very stable temperature of both detectors without any active components like valves or heaters inside. This method is called 2-phase Accumulator Controlled Loop (2PACL) and is a good candidate technology for the design of the future cooling systems for the Atlas and CMS upgrades.

  9. Towards Overhauser DNP in supercritical CO2

    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 1H 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 1H 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 2-4 ps, 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 3.4 T on high pressure superheated water and model systems such as toluene in high pressure CO2.

  10. CO2 flux geothermometer for geothermal exploration

    Science.gov (United States)

    Harvey, M. C.; Rowland, J. V.; Chiodini, G.; Rissmann, C. F.; Bloomberg, S.; Fridriksson, T.; Oladottir, A. A.

    2017-09-01

    A new geothermometer (TCO2 Flux) is proposed based on soil diffuse CO2 flux and shallow temperature measurements made on areas of steam heated, thermally altered ground above active geothermal systems. This CO2 flux geothermometer is based on a previously reported CO2 geothermometer that was designed for use with fumarole analysis. The new geothermometer provides a valuable additional exploration tool for estimating subsurface temperatures in high-temperature geothermal systems. Mean TCO2 Flux estimates fall within the range of deep drill hole temperatures at Wairakei (New Zealand), Tauhara (New Zealand), Rotokawa (New Zealand), Ohaaki (New Zealand), Reykjanes (Iceland) and Copahue (Argentina). The spatial distribution of geothermometry estimates is consistent with the location of major upflow zones previously reported at the Wairakei and Rotokawa geothermal systems. TCO2 Flux was also evaluated at White Island (New Zealand) and Reporoa (New Zealand), where limited sub-surface data exists. Mode TCO2 Flux at White Island is high (320 °C), the highest of the systems considered in this study. However, the geothermometer relies on mineral-water equilibrium in neutral pH reservoir fluids, and would not be reliable in such an active and acidic environment. Mean TCO2 Flux at Reporoa (310 °C) is high, which indicates Reporoa has a separate upflow from the nearby Waiotapu geothermal system; an outflow from Waiotapu would not be expected to have such high temperature.

  11. Towards Overhauser DNP in supercritical CO2.

    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.

  12. CO2-neutral cities. Apeldoorn, Heerhugowaard, Tilburg [Netherlands]; CO2-neutrale steden. Apeldoorn, Heerhugowaard, Tilburg

    Energy Technology Data Exchange (ETDEWEB)

    Roos, J.; Braber, K.; Voskuilen, Th.; Manders, H.; Rovers, V.

    2007-11-16

    The three Dutch cities of Apeldoorn, Heerhugowaard and Tilburg asked BuildDesk to undertake a survey of the options for realizing a CO2 neutral energy supply in their cities. In principle, this entails direct energy consumption for living, working (incl. industry) and mobility. With the developed 'Road maps towards CO2 neutral' each city holds their own guideline with which they can suit the action to the word. [mk]. [Dutch] De drie steden Apeldoorn, Heerhugowaard en Tilburg hebben BuildDesk de opdracht gegeven een verkenning uit te voeren naar de mogelijkheid om een CO2-neutrale energievoorziening in hun stad te realiseren. Daarbij gaat het in principe om het directe energiegebruik voor wonen, werken (incl. industrie) en mobiliteit. Met de ontwikkelde 'Roadmaps naar CO2-neutraal' heeft elke stad een eigen richtsnoer in handen waarmee ze actief de daad bij het woord kan voegen.

  13. Biosequestration of atmospheric CO2 and flue gas-containing CO2 by microalgae.

    Science.gov (United States)

    Cheah, Wai Yan; Show, Pau Loke; Chang, Jo-Shu; Ling, Tau Chuan; Juan, Joon Ching

    2015-05-01

    The unceasing rise of greenhouse gas emission has led to global warming and climate change. Global concern on this phenomenon has put forward the microalgal-based CO2 sequestration aiming to sequester carbon back to the biosphere, ultimately reducing greenhouse effects. Microalgae have recently gained enormous attention worldwide, to be the valuable feedstock for renewable energy production, due to their high growth rates, high lipid productivities and the ability to sequester carbon. The photosynthetic process of microalgae uses atmospheric CO2 and CO2 from flue gases, to synthesize nutrients for their growth. In this review article, we will primarily discuss the efficiency of CO2 biosequestration by microalgae species, factors influencing microalgal biomass productions, microalgal cultivation systems, the potential and limitations of using flue gas for microalgal cultivation as well as the bio-refinery approach of microalgal biomass.

  14. Anthropogenic point and area source CO2 plume measurements: Implications for spaceborne CO2 sensor design

    Science.gov (United States)

    Andrews, A. E.; Ryerson, T. B.; Peischl, J.; Parrish, D. D.; Trainer, M.; Tans, P. P.

    2011-12-01

    Anthropogenic point and area source CO2 plume measurements: Implications for spaceborne CO2 sensor design A. Andrews, T. Ryerson, J. Peischl, D. Parrish, M. Trainer, P. Tans An extensive dataset of CO2 concentrations including enhancements in point and area source plumes is available from in situ measurements collected using the NOAA P-3 and NCAR Electra research aircraft during seven major field projects from 1999 through 2010. Research flights sampled emission plumes from coal-, oil-, and natural gas-fired electric utility power plants, industrial facilities, and urban areas. Plume sampling often included horizontal transects at several altitudes and multiple distances downwind. CO2 data from crosswind transects upwind and downwind, coupled with ancillary measurements of co-emitted nitric oxide, nitrogen dioxide and sulfur dioxide, along with plume location, and wind speed and direction permit unambiguous attribution and quantification of atmospheric plumes from individual sources. Certain point sources were revisited on multiple flights over the course of 1-2 month long field projects and on successive field projects spanning several years. Sampling occurred primarily in the summertime, daytime continental boundary layer, with some plume studies performed after dark and in the spring, fall, and winter seasons. The data provide rigorously calibrated, measurement-based constraints on the expected range of atmospheric CO2 plume enhancements that can be used to assess satellite sensor concepts. Crosswind near-field (~5 km) transects in the summer daytime mixed-layer downwind of the strongest point sources were characterized by peak plume CO2 mixing ratio enhancements >100 ppm above background for the 100-m spatial averages reported from the moving aircraft. On many flights, the aircraft tracked such emissions plumes beyond 150 km downwind, or up to 10 hours of transport time, until plume enhancements were indistinguishable from background variability in CO2

  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. Entornos Agroambientales: Almacenes Naturales De Co2.

    Directory of Open Access Journals (Sweden)

    Juan Isidro Sánchez Leyva

    2005-01-01

    Full Text Available Cultivos únicos eternos y la extinción de especies; contaminaciones atmosféricas, edáficas e hídricas; la ampliación del agujero de la capa de Ozono, etc. unido al mal uso de la tierra contribuyen al empobrecimiento de comunidades y naciones. Se evaluaron sistemas de cultivos múltiples como sumideros naturales o bancos de CO2. Y se intercalaron leguminosas por sus conocidos y probados beneficios y otras especies anuales en árboles y arbustos conducidos desde 1988-90 en el macizo montañoso Sagüa-Baracoa, Gran Tierra de Sabaneta, El Salvador y valle Guaso provincia Guantánamo; Calabaza de Sagüa de Tánamo y Mayarí, Holguín. Diseñándose 3 ó 4 réplicas según las variantes y laderas y utilizados rangos múltiples de Newman-Kell (P<1%. Para el cálculo de biomasa vegetal se aplicaron fórmulas midiéndose la necromasa bajo el arbolado y el C orgánico edáfico. Se determinó el valor o índice relativo de biomasa, el índice relativo de banco de CO2 y el potencial mínimo de retención del CO2 en el sistema según la edad del cultivo; observándose el suelo erosionado en el predio mediante simple fórmula propuesta. Se observaron formas ecológicas de labor y cultivo. La canavalia fue el cultivo más efectivo considerando la respuesta del C edáfico. Se tuvo en cuenta la productividad y el banco de CO2 por el efecto positivo de ambos factores sobre el medio y dada la relevancia creciente de la reducción de las emisiones de CO2, a la vez que se evita la sobre-explotación y la deforestación. Se significó la necesidad de fajas interarboladas en monocultivos anuales.

  17. Seasonality affects macroalgal community response to increases in pCO2.

    Directory of Open Access Journals (Sweden)

    Cecilia Baggini

    Full Text Available Ocean acidification is expected to alter marine systems, but there is uncertainty about its effects due to the logistical difficulties of testing its large-scale and long-term effects. Responses of biological communities to increases in carbon dioxide can be assessed at CO2 seeps that cause chronic exposure to lower seawater pH over localised areas of seabed. Shifts in macroalgal communities have been described at temperate and tropical pCO2 seeps, but temporal and spatial replication of these observations is needed to strengthen confidence our predictions, especially because very few studies have been replicated between seasons. Here we describe the seawater chemistry and seasonal variability of macroalgal communities at CO2 seeps off Methana (Aegean Sea. Monitoring from 2011 to 2013 showed that seawater pH decreased to levels predicted for the end of this century at the seep site with no confounding gradients in Total Alkalinity, salinity, temperature or wave exposure. Most nutrient levels were similar along the pH gradient; silicate increased significantly with decreasing pH, but it was not limiting for algal growth at all sites. Metal concentrations in seaweed tissues varied between sites but did not consistently increase with pCO2. Our data on the flora are consistent with results from laboratory experiments and observations at Mediterranean CO2 seep sites in that benthic communities decreased in calcifying algal cover and increased in brown algal cover with increasing pCO2. This differs from the typical macroalgal community response to stress, which is a decrease in perennial brown algae and proliferation of opportunistic green algae. Cystoseira corniculata was more abundant in autumn and Sargassum vulgare in spring, whereas the articulated coralline alga Jania rubens was more abundant at reference sites in autumn. Diversity decreased with increasing CO2 regardless of season. Our results show that benthic community responses to ocean

  18. Strategies for CO2 capture from different CO2 emission sources by vacuum swing adsorption technology☆

    Institute of Scientific and Technical Information of China (English)

    Jianghua Ling; Penny Xiao; Augustine Ntiamoah; Dong Xu; Paul Webley; Yuchun Zhai

    2016-01-01

    Different VSA (Vacuum Swing Adsorption) cycles and process schemes have been evaluated to find suitable process configurations for effectively separating CO2 from flue gases from different industrial sectors. The cycles were studied using an adsorption simulator developed in our research group, which has been suc-cessfully used to predict experimental results over several years. Commercial zeolite APGIII and granular ac-tivated carbon were used as the adsorbents. Three-bed VSA cycles with-and without-product purge and 2-stage VSA systems have been investigated. It was found that for a feed gas containing 15%CO2 (representing flue gas from power plants), high CO2 purities and recoveries could be obtained using a three-bed zeolite APGIII VSA unit for one stage capture, but with more stringent conditions such as deeper vacuum pressures of 1–3 kPa. 2-stage VSA process operated in series allowed us to use simple process steps and operate at more realistic vacuum pressures. With a vacuum pressure of 10 kPa, final CO2 purity of 95.3%with a recov-ery of 98.2%were obtained at specific power consumption of 0.55 MJ·(kg CO2)−1 from feed gas containing 15%CO2. These numbers compare very well with those obtained from a single stage process operating at 1 kPa vacuum pressure. The feed CO2 concentration was very influential in determining the desorption pressure necessary to achieve high separation efficiency. For feed gases containing N30%CO2, a single-stage VSA capture process operating at moderate vacuum pressure and without a product purge, can achieve very high product purities and recoveries.

  19. CO2 for enhanced oil recovery and secure storage of CO2 in reservoirs

    OpenAIRE

    Li, Yunhang

    2015-01-01

    CO2-EOR(Enhanced Oil Recovery) is an effective and useful technology that can not only increase the oil production to meet the increasing need for energy around the world, but also mitigate the negtive influence of global green house effect. Different categories of oil recovery methods including primary recovery, secondary recovery, and EOR technologies are introduced at first. Then the history, global distribution, screening criteria, mechanisms, advantages and disadvantages of CO2-EOR are d...

  20. CO2 Sequestration within Spent Oil Shale

    Science.gov (United States)

    Foster, H.; Worrall, F.; Gluyas, J.; Morgan, C.; Fraser, J.

    2013-12-01

    Worldwide deposits of oil shales are thought to represent ~3 trillion barrels of oil. Jordanian oil shale deposits are extensive and of high quality, and could represent 100 billion barrels of oil, leading to much interest and activity in the development of these deposits. The exploitation of oil shales has raised a number of environmental concerns including: land use, waste disposal, water consumption, and greenhouse gas emissions. The dry retorting of oil shales can overcome a number of the environmental impacts, but this leaves concerns over management of spent oil shale and CO2 production. In this study we propose that the spent oil shale can be used to sequester CO2 from the retorting process. Here we show that by conducting experiments using high pressure reaction facilities, we can achieve successful carbonation of spent oil shale. High pressure reactor facilities in the Department of Earth Sciences, Durham University, are capable of reacting solids with a range of fluids up to 15 MPa and 350°C, being specially designed for research with supercritical fluids. Jordanian spent oil shale was reacted with high pressure CO2 in order to assess whether there is potential for sequestration. Fresh and reacted materials were then examined by: Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Thermogravimetric Analysis (TGA), X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) methods. Jordanian spent oil shale was found to sequester up to 5.8 wt % CO2, on reacting under supercritical conditions, which is 90% of the theoretical carbonation. Jordanian spent oil shale is composed of a large proportion of CaCO3, which on retorting decomposes, forming CaSO4 and Ca-oxides which are the focus of carbonation reactions. A factorially designed experiment was used to test different factors on the extent of carbonation, including: pressure; temperature; duration; and the water content. Analysis of Variance (ANOVA) techniques were then used to determine the significance of

  1. 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, th...

  2. 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...

  3. 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.

  4. Potential Improvements of Supercritical CO2 Brayton Cycle by Modifying Critical Point of CO2

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Woo Seok; Lee, Jeong Ik; Jeong, Yong Hoon; No, Hee Cheon [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2009-10-15

    A Sodium-cooled Fast Reactor (SFR) is one of strong candidates for a next generation nuclear reactor. However, the conventional design of a SFR concept with an indirect Rankine cycle is subjected to a sodium water reaction, which can deteriorate the safety of a SFR. To prevent any hazards from sodium-water reaction, a SFR with the Brayton cycle using Helium or Supercritical Carbon dioxide (S-CO2) as working fluids can be an alternative approach to improve the current SFR design. As in a helium cycle, there has been an investigation to modify thermo-physical properties to increase the efficiency of the cycle and reduce the size of turbomachineries. Particularly, He-Xe or He-N2 binary mixture were successful to decrease the stages of turbomachines due to the increment of molecular weight of gas mixture than that of pure helium. Similar to the case of helium, CO2 has a potential to modify its thermo-physical properties by mixing with other gases. For instance, it was reported that critical point of CO2 can be shifted by mixing with different gases. Since, the efficiency of a S-CO2 cycle is limited to the critical point of CO2, the shift in critical point implies that there is a possibility of improving the cycle efficiency than the current design. This paper presents the results of a preliminary analysis to identify the effects of CO2 critical point modification on the Brayton cycle performance.

  5. CO2 transport in normovolemic anemia: complete compensation and stability of blood CO2 tensions.

    Science.gov (United States)

    Deem, S; Alberts, M K; Bishop, M J; Bidani, A; Swenson, E R

    1997-07-01

    Isovolemic hemodilution does not appear to impair CO2 elimination nor cause CO2 retention despite the important role of red blood cells in blood CO2 transport. We studied this phenomenon and its physiological basis in eight New Zealand White rabbits that were anesthetized, paralyzed, and mechanically ventilated at a fixed minute ventilation. Isovolemic anemia was induced by simultaneous blood withdrawal and infusion of 6% hetastarch in sequential stages; exchange transfusions ranged from 15-30 ml in volume. Variables measured after each hemodilution included hematocrit (Hct), arterial and venous blood gases, mixed expired PCO2 and PO2, and blood pressure; also, O2 consumption, CO2 production, cardiac output (Q), and physiological dead space were calculated. Data were analyzed by comparison of changes in variables with changes in Hct and by using the model of capillary gas exchange described by Bidani (J. Appl. Physiol. 70: 1686-1699, 1991). There was complete compensation for anemia with stability of venous and arterial PCO2 between Hct values of 36 +/- 3 and 12 +/- 1%, which was predicted by the mathematical model. Over this range of hemodilution, Q rose 50%, and the O2 extraction ratio increased 61% without a decline in CO2 production or a rise in alveolar ventilation. The dominant compensations maintaining CO2 transport in normovolemic anemia include an increased Q and an augmented Haldane effect arising from the accompanying greater O2 extraction.

  6. CO2-Responsive Polymer-Functionalized Au Nanoparticles for CO2 Sensor.

    Science.gov (United States)

    Ma, Ying; Promthaveepong, Kittithat; Li, Nan

    2016-08-16

    Metallic nanoparticles (NPs) coated with stimuli-responsive polymers (SRPs) exhibit tunable optical properties responding to external stimuli and show promising sensing applications. We present a new CO2-responsive polymer, poly(N-(3-amidino)-aniline) (PNAAN), coated gold NPs (AuNPs) synthesized by directly reducing HAuCl4 with a CO2-responsive monomer N-(3-amidino)-aniline (NAAN). The amidine group of PNAAN can be protonated into a hydrophilic amidinium group by dissolved CO2 (dCO2). This induces the PNAAN to swell and detach from the AuNP surface, resulting in AuNP aggregation and color change. By monitoring the UV absorbance change of AuNPs, a sensitive dCO2 sensor with a linear range of 0.0132 to 0.1584 hPa and a limit of detection (LOD) of 0.0024 hPa is developed. This method shows dramatic improvement in sensitivity and convenience of sample preparation compared with the previously reported dCO2 sensor.

  7. Estimation of CO2 storage flux between forest and atmosphere in a tropical forest.%热带森林植被冠层CO2储存项的估算方法研究

    Institute of Scientific and Technical Information of China (English)

    姚玉刚; 张一平; 于贵瑞; 宋清海; 谭正洪; 赵俊斌

    2011-01-01

    评价植被冠层CO2储存项有助于提高森林-大气层面净生态系统CO2交换量(FNEE)的估算精度.基于西双版纳热带季节雨林2年完整的涡度相关系统和CO2廓线的同步观测资料,详细分析涡度相关法(Fs-EC)和廓线法(Fs-PM)CO2储存项估算结果和变化趋势.结果表明:1)廓线法CO2储存项年平均日变化曲线相比涡度相关法能更真实地反映冠层内外CO2浓度时空变化特征.2)廓线法估算的CO2储存项年总量值为-0.04 t/(hm2·a),涡度相关法为-0.17 t/(hm2·a).3)由于复杂地形条件下的西双版纳热带季节雨林存在较大CO2浓度梯度,采用廓线法进行CO2储存项估算比涡度相关法更为合适.%Evaluating CO2 storage flux may help us to improve the calculation accuracy of net ecosystem CO2 exchange (FNEE). Based on data of two consecutive years from an eddy covariance system and a vertical CO2 profile system in a tropical seasonal rainforest in Xishuangbanna, southwest China, CO2 storage flux was calculated by two methods, eddy covariance ( F.-EC ) and profile ( F.-PM ) methods. Results show that:1 ) Comparing with eddy covariance method, diurnal variation of CO2 storage flux calculated by profile method could directly reflect the spatial-temporal variation of CO2; 2) Total amount value of CO2 storage flux calculated by profile method was -0. 04 t/( hm2· year), and the value calculated by eddy covariance method was -0. 17 t/(hm2 ·year); 3) Under complex terrain and tall forest conditions, with a large concentration gradient of CO2, profile method for calculation of CO2 storage flux had an advantage over eddy covariance method.

  8. Carbon Sequestration: Hydrogenation of CO2 to Formic Acid

    OpenAIRE

    2016-01-01

    The concentration CO2 gas has become a great worldwide challenge because CO2 is considered as an important counterpart of greenhouse gases. The tremendous increase in the concentration of CO2 gas, elevated the worldwide temperature as well as it altered the climatic changes. Various physiochemical approached have been reported to trap the CO2 gas and the chemical conversion of CO2 to useful chemicals is one of them. This review covers the conversion of CO2 gas to formic acid. In this CO2 hydr...

  9. Carbon Sequestration: Hydrogenation of CO2 to Formic Acid

    Directory of Open Access Journals (Sweden)

    Upadhyay Praveenkumar

    2016-10-01

    Full Text Available The concentration CO2 gas has become a great worldwide challenge because CO2 is considered as an important counterpart of greenhouse gases. The tremendous increase in the concentration of CO2 gas, elevated the worldwide temperature as well as it altered the climatic changes. Various physiochemical approached have been reported to trap the CO2 gas and the chemical conversion of CO2 to useful chemicals is one of them. This review covers the conversion of CO2 gas to formic acid. In this CO2 hydrogenation reaction, both the homogeneous as well as heterogeneous catalytic systems were discussed along with the effect of solvent systems on reaction kinetics.

  10. Air–sea CO2 fluxes and the controls on ocean surface pCO2 variability in coastal and open-ocean southwestern Atlantic Ocean: a modeling study

    Directory of Open Access Journals (Sweden)

    R. Arruda

    2015-05-01

    Full Text Available We use an eddy-resolving, regional ocean biogeochemical model to investigate the main variables and processes responsible for the climatological spatio-temporal variability of pCO2 and the air–sea CO2 fluxes in the southwestern Atlantic Ocean. Overall, the region acts as sink of atmospheric CO2 south of 30° S, and is close to equilibrium with the atmospheric CO2 to the north. On the shelves, the ocean acts as a weak source of CO2, except for the mid/outer shelves of Patagonia, which act as sinks. In contrast, the inner shelves and the low latitude open ocean of the southwestern Atlantic represent source regions. Observed nearshore-to-offshore and meridional pCO2 gradients are well represented by our simulation. A sensitivity analysis shows the importance of the counteracting effects of temperature and dissolved inorganic carbon (DIC in controlling the seasonal variability of pCO2. Biological production and solubility are the main processes regulating pCO2, with biological production being particularly important on the shelf regions. The role of mixing/stratification in modulating DIC, and therefore surface pCO2 is shown in a vertical profile at the location of the Ocean Observatories Initiative (OOI site in the Argentine Basin (42° S, 42° W.

  11. Simulation Studies for a Space-Based CO2 Lidar Mission

    Science.gov (United States)

    Kawa, S. R.; Mao, J.; Abshire, J. B.; Collatz, G. J.; Sun, X.; Weaver, C. J.

    2010-01-01

    We report results of initial space mission simulation studies for a laser-based, atmospheric CO2 sounder, which are based on real-time carbon cycle process modelling and data analysis. The mission concept corresponds to the Active Sensing of CO2 Emissions over Nights, Days and Seasons (ASCENDS) recommended by the US National Academy of Sciences' Decadal Survey. As a pre-requisite for meaningful quantitative evaluation, we employ a CO2 model that has representative spatial and temporal gradients across a wide range of scales. In addition, a relatively complete description of the atmospheric and surface state is obtained from meteorological data assimilation and satellite measurements. We use radiative transfer calculations, an instrument model with representative errors and a simple retrieval approach to quantify errors in 'measured' CO2 distributions, which are a function of mission and instrument design specifications along with the atmospheric/surface state. Uncertainty estimates based on the current instrument design point indicate that a CO2 laser sounder can provide data consistent with ASCENDS requirements and will significantly enhance our ability to address carbon cycle science questions. Test of a dawn/dusk orbit deployment, however, shows that diurnal differences in CO2 column abundance, indicative of plant photosynthesis and respiration fluxes, will be difficult to detect

  12. Process-dependent residual trapping of CO2 in sandstone

    Science.gov (United States)

    Zuo, Lin; Benson, Sally M.

    2014-04-01

    This paper demonstrates that the nature and extent of residual CO2 trapping depend on the process by which the CO2 phase is introduced into the rock. We compare residual trapping of CO2 in Berea Sandstone by imbibing water into a core containing either exsolved CO2 or CO2 introduced by drainage. X-ray computed tomography measurements are used to map the spatial distribution of CO2 preimbibition and postimbibition. Unlike during drainage where the CO2 distribution is strongly influenced by the heterogeneity of the rock, the distribution of exsolved CO2 is comparatively uniform. Postimbibition, the CO2 distribution retained the essential features for both the exsolved and drainage cases, but twice as much residual trapping is observed for exsolved CO2 even with similar preimbibition gas saturations. Residually trapped exsolved gas also disproportionately reduced water relative permeability. Development of process-dependent parameterization will help better manage subsurface flow processes and unlock benefits from gas exsolution.

  13. The Werkendam natural CO2 accumulation: An analogue for CO2 storage in depleted oil reservoirs

    Science.gov (United States)

    Bertier, Pieter; Busch, Andreas; Hangx, Suzanne; Kampman, Niko; Nover, Georg; Stanjek, Helge; Weniger, Philipp

    2015-04-01

    The Werkendam natural CO2 accumulation is hosted in the Röt (Early Triassic) sandstone of the West Netherlands Basin, at a depth of 2.8 km, about 20 km south-east of Rotterdam (NL). This reservoir, in a fault-bound structure, was oil-filled prior to charging with magmatic CO2 in the early Cretaceous. It therefore offers a unique opportunity to study long-term CO2-water-rock interactions in the presence of oil. This contribution will present the results of a detailed mineralogical and geochemical characterisation of core sections from the Werkendam CO2 reservoir and an adjacent, stratigraphically equivalent aquifer. X-ray diffraction combined with X-ray fluorescence spectrometry revealed that the reservoir samples contain substantially more feldspar and more barite and siderite than those from the aquifer, while the latter have higher hematite contents. These differences are attributed to the effects hydrocarbons and related fluids on diagenesis in the closed system of the CO2 reservoir versus the open-system of the aquifer. Petrophysical analyses yielded overall higher and more anisotropic permeability for the reservoir samples, while the porosity is overall not significantly different from that of their aquifer equivalents. The differences are most pronounced in coarse-grained sandstones. These have low anhydrite contents and contain traces of calcite, while all other analyzed samples contain abundant anhydrite, dolomite/ankerite and siderite, but no calcite. Detailed petrography revealed mm-sized zones of excessive primary porosity. These are attributed to CO2-induced dissolution of precompactional, grain-replacive anhydrite cement. Diagenetic dolomite/ankerite crystals are covered by anhedral, epitaxial ankerite, separated from the crystals by bitumen coats. Since these carbonates were oil-wet before CO2-charging, the overgrowths are interpreted to have grown after CO2-charging. Their anhedral habit suggests growth in a 2-phase water-CO2 system. Isotopic

  14. THERMODYNAMIC ANALYSIS OF CO2 DIRECT HYDROGENATION REACTIONS

    Institute of Scientific and Technical Information of China (English)

    Cao Fahai; Liu Dianhua; Hou Qiushi; Fang Dingye

    2001-01-01

    CO2 hydrogenation is one of important routes for the activation and effective utilization of CO2. In this paper, eighteen CO2 direct hydrogenation reactions are listed and their reaction heats and equilibrium constants are calculated. On the assumption that the reactions of CO2 and H2 are in stoichiometric ratio and the amount of whole reactants is one mole, the equilibrium conversions of CO2 are obtained.

  15. 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...

  16. Mechanisms of CO2 Capture into Monoethanolamine Solution with Different CO2 Loading during the Absorption/Desorption Processes.

    Science.gov (United States)

    Lv, Bihong; Guo, Bingsong; Zhou, Zuoming; Jing, Guohua

    2015-09-01

    Though the mechanism of MEA-CO2 system has been widely studied, there is few literature on the detailed mechanism of CO2 capture into MEA solution with different CO2 loading during absorption/desorption processes. To get a clear picture of the process mechanism, (13)C nuclear magnetic resonance (NMR) was used to analyze the reaction intermediates under different CO2 loadings and detailed mechanism on CO2 absorption and desorption in MEA was evaluated in this work. The results demonstrated that the CO2 absorption in MEA started with the formation of carbamate according to the zwitterion mechanism, followed by the hydration of CO2 to form HCO3(-)/CO3(2-), and accompanied by the hydrolysis of carbamate. It is interesting to find that the existence of carbamate will be influenced by CO2 loading and that it is rather unstable at high CO2 loading. At low CO2 loading, carbamate is formed fast by the reaction between CO2 and MEA. At high CO2 loading, it is formed by the reaction of CO3(-)/CO3(2-) with MEA, and the formed carbamate can be easily hydrolyzed by H(+). Moreover, CO2 desorption from the CO2-saturated MEA solution was proved to be a reverse process of absorption. Initially, some HCO3(-) were heated to release CO2 and other HCO3(-) were reacted with carbamic acid (MEAH(+)) to form carbamate, and the carbamate was then decomposed to MEA and CO2.

  17. Anthropogenic CO2 emissions in Africa

    Directory of Open Access Journals (Sweden)

    R. A. Houghton

    2008-11-01

    Full Text Available An understanding of the regional contributions and trends of anthropogenic carbon dioxide (CO2 emissions is critical to design mitigation strategies aimed at stabilizing atmospheric greenhouse gases. Here we report CO2 emissions from the combustion of fossil fuels and land use change in Africa for various time periods. Africa was responsible for an average of 500 TgC y−1 for the period 2000–2005. These emissions resulted from the combustion of fossil fuels (260 TgC y−1 and land use change (240 TgC y−1. Over this period, the African share of global emissions from land use change was 17%. For 2005, the last year reported in this study, African fossil fuel emissions were 285 TgC accounting for 3.7% of the global emissions. The 2000–2005 growth rate in African fossil fuel emissions was 3.2% y−1, very close to the global average. Fossil fuel emissions per capita in Africa are among the lowest in the world, at 0.32 tC y−1 compared to the global average of 1.2 tC y−1. The average amount of carbon (C emitted as CO2 to produce 1 US $ of Gross Domestic Product (GDP in Africa in 2005 was 187 gC/$, close to the world average of 199 gC/$. With the fastest population growth in the world and rising per capita GDP, Africa is likely to increase its share of global emissions over the coming decades although emissions from Africa will remain low compared to other continents.

  18. 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.

  19. CO2刺激响应聚合物%CO2-Stimuli Responsive Polymers

    Institute of Scientific and Technical Information of China (English)

    冯岸超; 闫强; 袁金颖

    2012-01-01

    CO2刺激响应性聚合物是新近发展起来的一类智能型刺激响应聚合物,是指在通入和排出CO2后,聚合物性质能够发生可逆性变化的新型聚合物。由于调控过程中仅仅涉及CO2以及一些惰性气体而不引入其他杂质,因此具有多方面的潜在应用价值。本文调研了这方面的工作,综述了几类CO2刺激响应聚合物的合成及其自组装,并指出了CO2刺激响应聚合物的应用前景和发展方向。%CO2-stimuli responsive polymers are a class of newly developed smart stimuli responsive polymers, which usually refers to the polymers possessing reversible changes upon admission and emission of C02. Since the regulation process only involves CO2 and inert gases, without the introduction of other impurities, there are many potential applications in this field. This article summarized recent research progress on the preparation of C02- stimuli responsive polymers, followed by the discussion of their self-assembly, classifying in accordance with the C02-switchable groups, such as primary amine, amide and some specific polymer chains. The development prospect of this research field and its potential applications are also discussed.

  20. On which timescales do gas transfer velocities control North Atlantic CO2 flux variability?

    Science.gov (United States)

    Couldrey, Matthew P.; Oliver, Kevin I. C.; Yool, Andrew; Halloran, Paul R.; Achterberg, Eric P.

    2016-05-01

    The North Atlantic is an important basin for the global ocean's uptake of anthropogenic and natural carbon dioxide (CO2), but the mechanisms controlling this carbon flux are not fully understood. The air-sea flux of CO2, F, is the product of a gas transfer velocity, k, the air-sea CO2 concentration gradient, ΔpCO2, and the temperature- and salinity-dependent solubility coefficient, α. k is difficult to constrain, representing the dominant uncertainty in F on short (instantaneous to interannual) timescales. Previous work shows that in the North Atlantic, ΔpCO2 and k both contribute significantly to interannual F variability but that k is unimportant for multidecadal variability. On some timescale between interannual and multidecadal, gas transfer velocity variability and its associated uncertainty become negligible. Here we quantify this critical timescale for the first time. Using an ocean model, we determine the importance of k, ΔpCO2, and α on a range of timescales. On interannual and shorter timescales, both ΔpCO2 and k are important controls on F. In contrast, pentadal to multidecadal North Atlantic flux variability is driven almost entirely by ΔpCO2; k contributes less than 25%. Finally, we explore how accurately one can estimate North Atlantic F without a knowledge of nonseasonal k variability, finding it possible for interannual and longer timescales. These findings suggest that continued efforts to better constrain gas transfer velocities are necessary to quantify interannual variability in the North Atlantic carbon sink. However, uncertainty in k variability is unlikely to limit the accuracy of estimates of longer-term flux variability.

  1. The carbon dioxide system on the Mississippi River-dominated continental shelf in the northern Gulf of Mexico: 1. Distribution and air-sea CO2 flux.

    Science.gov (United States)

    Huang, Wei-Jen; Cai, Wei-Jun; Wang, Yongchen; Lohrenz, Steven E; Murrell, Michael C

    2015-03-01

    River-dominated continental shelf environments are active sites of air-sea CO2 exchange. We conducted 13 cruises in the northern Gulf of Mexico, a region strongly influenced by fresh water and nutrients delivered from the Mississippi and Atchafalaya River system. The sea surface partial pressure of carbon dioxide (pCO2) was measured, and the air-sea CO2 flux was calculated. Results show that CO2 exchange exhibited a distinct seasonality: the study area was a net sink of atmospheric CO2 during spring and early summer, and it was neutral or a weak source of CO2 to the atmosphere during midsummer, fall, and winter. Along the salinity gradient, across the shelf, the sea surface shifted from a source of CO2 in low-salinity zones (0≤S<17) to a strong CO2 sink in the middle-to-high-salinity zones (17≤S<33), and finally was a near-neutral state in the high-salinity areas (33≤S<35) and in the open gulf (S≥35). High pCO2 values were only observed in narrow regions near freshwater sources, and the distribution of undersaturated pCO2 generally reflected the influence of freshwater inputs along the shelf. Systematic analyses of pCO2 variation demonstrated the importance of riverine nitrogen export; that is, riverine nitrogen-enhanced biological removal, along with mixing processes, dominated pCO2 variation along the salinity gradient. In addition, extreme or unusual weather events were observed to alter the alongshore pCO2 distribution and to affect regional air-sea CO2 flux estimates. Overall, the study region acted as a net CO2 sink of 0.96 ± 3.7 mol m(-2) yr(-1) (1.15 ± 4.4 Tg C yr(-1)).

  2. CO2 acclimation impacts leaf isoprene emissions: evidence from past to future CO2 levels

    Science.gov (United States)

    de Boer, Hugo; van der Laan, Annick; Dekker, Stefan; Holzinger, Rupert

    2017-04-01

    Isoprene is emitted by many plant species as a side-product of photosynthesis. Once in the atmosphere, isoprene exhibits climate forcing through various feedback mechanisms. In order to quantify the climate feedbacks of biogenic isoprene emission it is crucial to establish how isoprene emissions are effected by plant acclimation to rising atmospheric CO2 levels. A promising development for modelling CO2-induced changes in isoprene emissions is the Leaf-Energetic-Status model (referred to as LES-model hereafter, see Harrison et al., 2013 and Morfopoulos et al., 2014). This model simulates isoprene emissions based on the hypothesis that isoprene biosynthesis depends on the imbalance between the photosynthetic electron supply of reducing power and the electron demands of carbon fixation. The energetic imbalance is critically related to the photosynthetic electron transport capacity (Jmax) and the maximum carboxylation capacity of Rubisco (Vcmax). Here we compare predictions of the LES-model with observed isoprene emission responses of Quercus robur (pedunculate oak) specimen that acclimated to CO2 growth conditions representative of the last glacial, the present and the end of this century (200, 400 and 800 ppm, respectively) for two growing seasons. These plants were grown in walk-in growth chambers with tight control of light, temperature, humidity and CO2 concentrations. Photosynthetic biochemical parameters Vcmax and Jmax were determined with a Licor LI-6400XT photosynthesis system. The relationship between photosynthesis and isoprene emissions was measured by coupling the photosynthesis system with a Proton-Transfer Reaction Time-of-Flight Mass Spectrometer. Our empirical results support the LES-model and show that the fractional allocation of carbon to isoprene biosynthesis is reduced in response to both short-term and long-term CO2 increases. In the short term, an increase in CO2 stimulates photosynthesis through an increase in the leaf interior CO2

  3. The Influence of CO2 Solubility in Brine on Simulation of CO2 Injection into Water Flooded Reservoir and CO2 WAG

    DEFF Research Database (Denmark)

    Yan, Wei; Stenby, Erling Halfdan

    2010-01-01

    Injection of CO2 into depleted oil reservoirs is not only a traditional way to enhance oil recovery but also a relatively cheaper way to sequester CO2 underground since the increased oil production can offset some sequestration cost. CO2 injection process is often applied to water flooded...... reservoirs and in many situations alternating injection of water and CO2 is required to stabilize the injection front. Both scenarios involve a large amount of water, making CO2 solubility in brine, which is around ten times higher than methane solubility, a non-negligible factor in the relevant reservoir...... simulations. In our previous study, a 1-D slimtube simulator, which rigorously accounts for both CO2 solubility in brine and water content in hydrocarbon phases using the Peng-Robinson EoS modified by Soreide and Whitson, has been used to investigate the influence of CO2 solubility on the simulation...

  4. 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

  5. Translating crustacean biological responses from CO2 ...

    Science.gov (United States)

    Many studies of animal responses to ocean acidification focus on uniformly conditioned age cohorts that lack complexities typically found in wild populations. These studies have become the primary data source for predicting higher level ecological effects, but the roles of intraspecific interactions in re-shaping biological, demographic and evolutionary responses are not commonly considered. To explore this problem, I assessed responses in the mysid Americamysis bahia to bubbling of CO2-enriched and un-enriched air into the seawater supply in flow-through aquariums. I conducted one experiment using isolated age cohorts and a separate experiment using intact populations. The seawater supply was continuously input from Narragansett Bay (Rhode Island, USA). The 28-day cohort study was maintained without resource or spatial limitations, whereas the 5-month population study consisted of stage-structured populations that were allowed to self-regulate. These differences are common features of experiments and were intentionally retained to demonstrate the effect of methodological approaches on perceptions of effect mechanisms. The CO2 treatment reduced neonate abundance in the cohort experiment (24% reduction due to a mean pH difference of −0.27) but not in the population experiment, where effects were small and were strongest for adult and stage 1 survival (3% change due to a mean pH difference of −0.25). I also found evidence of competition in the population exper

  6. 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.

  7. On Leakage from Geologic Storage Reservoirs of CO2

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, Karsten

    2006-02-14

    Large amounts of CO2 would need to be injected underground to achieve a significant reduction of atmospheric emissions. The large areal extent expected for CO2 plumes makes it likely that caprock imperfections will be encountered, such as fault zones or fractures, which may allow some CO2 to escape from the primary storage reservoir. Leakage of CO2 could also occur along wellbores. Concerns with escape of CO2 from a primary geologic storage reservoir include (1) acidification of groundwater resources, (2) asphyxiation hazard when leaking CO2 is discharged at the land surface, (3) increase in atmospheric concentrations of CO2, and (4) damage from a high-energy, eruptive discharge (if such discharge is physically possible). In order to gain public acceptance for geologic storage as a viable technology for reducing atmospheric emissions of CO2, it is necessary to address these issues and demonstrate that CO2 can be injected and stored safely in geologic formations.

  8. 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.

  9. CO(2) Inhibits Respiration in Leaves of Rumex crispus L.

    Science.gov (United States)

    Amthor, J S; Koch, G W; Bloom, A J

    1992-02-01

    Curly dock (Rumex crispus L.) was grown from seed in a glasshouse at an ambient CO(2) partial pressure of about 35 pascals. Apparent respiration rate (CO(2) efflux in the dark) of expanded leaves was then measured at ambient CO(2) partial pressure of 5 to 95 pascals. Calculated intercellular CO(2) partial pressure was proportional to ambient CO(2) partial pressure in these short-term experiments. The CO(2) level strongly affected apparent respiration rate: a doubling of the partial pressure of CO(2) typically inhibited respiration by 25 to 30%, whereas a decrease in CO(2) elicited a corresponding increase in respiration. These responses were readily reversible. A flexible, sensitive regulatory interaction between CO(2) (a byproduct of respiration) and some component(s) of heterotrophic metabolism is indicated.

  10. Investigation of CO2 precursors in roasted coffee.

    Science.gov (United States)

    Wang, Xiuju; Lim, Loong-Tak

    2017-03-15

    Two CO2 formation pathways (chlorogenic acid (CGA) degradation and Maillard reaction) during coffee roasting were investigated. CGA is shown not a major contributor to CO2 formation, as heating of this compound under typical roasting conditions did not release a large quantity of CO2. However, heating of a CGA moiety, caffeic acid, resulted in high yield of CO2 (>98%), suggesting that CGA hydrolysis could be the rate limiting step for CO2 formation from CGA. A large amount of CO2 was detected from glycine-sucrose model system under coffee roasting conditions, implying the importance of Maillard reactions in CO2 formation. Further studies on the heating of various components isolated from green coffee beans showed that CO2 was generated from various green coffee components, including water insoluble proteins and polysaccharides. Around 50% of CO2 was formed from thermal reactions of lower molecular weight compounds that represent ∼25% by weight in green coffee.

  11. Winter greenhouse gas fluxes (CO2, CH4 and N2O from a subalpine grassland

    Directory of Open Access Journals (Sweden)

    L. Merbold

    2013-05-01

    Full Text Available Although greenhouse gas emissions during winter contribute significantly to annual balances, their quantification is still highly uncertain in snow-covered ecosystems. Here, carbon dioxide (CO2, methane (CH4 and nitrous oxide (N2O fluxes were measured at a subalpine managed grassland in Switzerland using concentration gradients within the snowpack (CO2, CH4, N2O and the eddy covariance method (CO2 during the winter 2010/2011. Our objectives were (1 to identify the temporal and spatial variation of greenhouse gases (GHGs and their drivers, and (2 to estimate the GHG budget of the site during this specific season (1 December–31 March, 121 days. Mean winter fluxes (December–March based on the gradient method were 0.77 ± 0.54 μmol m−2 s−1 for CO2 (1.19 ± 1.05 μmol m−2 s−1 measured by eddy covariance, −0.14 ± 0.09 nmol m−2 s−1 for CH4 and 0.23 ± 0.23 nmol m−2 s−1 for N2O, respectively. In comparison with the CO2 fluxes measured by eddy covariance, the gradient technique underestimated the effluxes by 50%. While CO2 and CH4 fluxes decreased with the progressing winter season, N2O fluxes did not follow a seasonal pattern. The major variables correlating with the fluxes of CO2 and CH4 were soil temperature and snow water equivalent, which is based on snow height and snow density. N2O fluxes were only explained poorly by any of the measured environmental variables. Spatial variability across the valley floor was smallest for CO2 and largest for N2O. During the winter season 2010/2011, greenhouse gas fluxes ranged between 550 ± 540 g CO2 m−2 estimated by the eddy covariance approach and 543 ± 247 g CO2 m−2, −0.4 ± 0.01 g CH4 m−2 and 0.11 ± 0.1 g N2O m−2 derived by the gradient technique. Total seasonal greenhouse gas emissions from the grassland were between 574 ± 276 and 581 ± 569 g CO2 eq. m−2, with N2O contributing 5% to the overall budget and CH4 reducing the budget by 0.1%. Cumulative budgets of CO2 were

  12. Soret Effect Study on High-Pressure CO2-Water Solutions Using UV-Raman Spectroscopy and a Concentric-Tube Optical Cell

    Energy Technology Data Exchange (ETDEWEB)

    Windisch, Charles F.; McGrail, B. Peter; Maupin, Gary D.

    2012-01-01

    Spatially resolved deep-UV Raman spectroscopy was applied to solutions of CO2 and H2O (or D2O), which were subject to a temperature gradient in a thermally regulated high-pressure concentric-tube Raman cell in an attempt to measure a Soret effect in the vicinity of the critical point of CO2. Although Raman spectra of solutions of CO2 dissolved in D2O at 10 MPa and temperatures near the critical point of CO2 had adequate signal-to-noise and spatial resolution to observe a Soret effect with a Soret coefficient with magnitude of |ST| > 0.03, no evidence for an effect of this size was obtained for applied temperature gradients up to 19oC. The presence of 1 M NaCl did not make a difference. In contrast, the concentration of CO2 dissolved in H2O was shown to vary significantly across the temperature gradient when excess CO2 was present, but the results could be explained simply by the variation in CO2 solubility over the temperature range and not to kinetic factors. For mixtures of D2O dissolved in scCO2 at 10 MPa and temperatures close to the critical point of CO2, the Raman peaks for H2O were too weak to measure with confidence even at the limit of D2O solubility.

  13. Field lysimeter investigations: Low-level waste data base development program for fiscal year 1996. Annual report; Volume 9

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, J.W. Jr.; Rogers, R.D.; Larsen, I.L. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.; Jastrow, J.D. [Argonne National Lab., IL (United States); Sanford, W.E. [Oak Ridge National Lab., TN (United States); Sullivan, T.M.; Fuhrmann, M. [Brookhaven National Lab., Upton, NY (United States)

    1997-08-01

    A data base development program, funded by the US Nuclear Regulatory Commission, is (a) studying the degradation effects in organic ion-exchange resins caused by radiation, (b) examining the adequacy of test procedures recommended in the Branch Technical Position on Waste Form to meet the requirements of 10 CFR 61 using solidified ion-exchange resins, (c) obtaining performance information on solidified ion-exchange resins in a disposal environment, and (d) determining the condition of liners used to dispose the ion-exchange resins. During the field testing experiments, both portland type 1--2 cement and Dow vinyl ester-styrene waste form samples were tested in lysimeter arrays located at Argonne National Laboratory-East (ANL-E) in Illinois and at Oak Ridge National Laboratory (ORNL). The study was designed to provide continuous data on nuclide release and movement, as well as environmental conditions, over an extended period. Those experiments have been shut down and are to be exhumed. This report discusses the plans for removal, sampling, and analysis of waste form and soil cores from the lysimeters. Results of partition coefficient determinations are presented, as well as application of a source term computer code using those coefficients to predict the lysimeter results. A study of radionuclide-containing colloids associated with the leachate waters removed from these lysimeters is described. An update of upward migration of radionuclides in the sand-filled lysimeter at ORNL is included.

  14. Recent widespread tree growth decline despite increasing atmospheric CO2.

    Directory of Open Access Journals (Sweden)

    Lucas C R Silva

    Full Text Available BACKGROUND: The synergetic effects of recent rising atmospheric CO(2 and temperature are expected to favor tree growth in boreal and temperate forests. However, recent dendrochronological studies have shown site-specific unprecedented growth enhancements or declines. The question of whether either of these trends is caused by changes in the atmosphere remains unanswered because dendrochronology alone has not been able to clarify the physiological basis of such trends. METHODOLOGY/PRINCIPAL FINDINGS: Here we combined standard dendrochronological methods with carbon isotopic analysis to investigate whether atmospheric changes enhanced water use efficiency (WUE and growth of two deciduous and two coniferous tree species along a 9 degrees latitudinal gradient across temperate and boreal forests in Ontario, Canada. Our results show that although trees have had around 53% increases in WUE over the past century, growth decline (measured as a decrease in basal area increment--BAI has been the prevalent response in recent decades irrespective of species identity and latitude. Since the 1950s, tree BAI was predominantly negatively correlated with warmer climates and/or positively correlated with precipitation, suggesting warming induced water stress. However, where growth declines were not explained by climate, WUE and BAI were linearly and positively correlated, showing that declines are not always attributable to warming induced stress and additional stressors may exist. CONCLUSIONS: Our results show an unexpected widespread tree growth decline in temperate and boreal forests due to warming induced stress but are also suggestive of additional stressors. Rising atmospheric CO2 levels during the past century resulted in consistent increases in water use efficiency, but this did not prevent growth decline. These findings challenge current predictions of increasing terrestrial carbon stocks under climate change scenarios.

  15. Approach to novel design of CO2 based centrifugal compressor

    Directory of Open Access Journals (Sweden)

    Kura Tomasz

    2016-01-01

    Full Text Available Even though turbomachinery design issues have been investigated almost since the beginning of engineering, its optimization process is still important. With the development of refrigeration devices and ORC based distributed generation facilities, a need for efficient and low-energy compressors and turbines became even more demanding. Such machines working with typical fluid, like air, are well described, but there is a room regarding the fluids like CO2, vapour of organic fluids, etc. The main objective of present studies is to propose a numerical model of the centrifugal compressor, with CO2 as the working fluid. Such unit may be a part of refrigeration cycle. Commonly, the scroll or piston compressors are used in such cases, however some discussed disadvantages show that the novel designs should be looked for. Properly designed centrifugal compressors can have higher efficiency than the presently used. Three dimensional analyses of proposed geometries were conducted – using a model including heat, mass and momentum conservation laws as well as ideal gas law. Verification of the proposed mesh and results was performed in the basis of values obtained using theoretical and empirical equations. With about 700 000 control volumes in the validated model, error of the results was no higher than 5%, with only about 1% in regards to the thermal parameters. Two design proposals were analysed, with performance maps as the main comparison factor. Apart from performance characteristics, the pressure and velocity fields were presented, showing the process of flow structure optimization. The main goal was to reduce negative effects of pressure and velocity gradients on the performance. Proposed precursory design might be a good starting point for further development of compressors. The results of numerical analysis were promising and shows the possibility of proposed design usage in practical applications, however to obtain deep understanding of the

  16. Recent widespread tree growth decline despite increasing atmospheric CO2.

    Science.gov (United States)

    Silva, Lucas C R; Anand, Madhur; Leithead, Mark D

    2010-07-21

    The synergetic effects of recent rising atmospheric CO(2) and temperature are expected to favor tree growth in boreal and temperate forests. However, recent dendrochronological studies have shown site-specific unprecedented growth enhancements or declines. The question of whether either of these trends is caused by changes in the atmosphere remains unanswered because dendrochronology alone has not been able to clarify the physiological basis of such trends. Here we combined standard dendrochronological methods with carbon isotopic analysis to investigate whether atmospheric changes enhanced water use efficiency (WUE) and growth of two deciduous and two coniferous tree species along a 9 degrees latitudinal gradient across temperate and boreal forests in Ontario, Canada. Our results show that although trees have had around 53% increases in WUE over the past century, growth decline (measured as a decrease in basal area increment--BAI) has been the prevalent response in recent decades irrespective of species identity and latitude. Since the 1950s, tree BAI was predominantly negatively correlated with warmer climates and/or positively correlated with precipitation, suggesting warming induced water stress. However, where growth declines were not explained by climate, WUE and BAI were linearly and positively correlated, showing that declines are not always attributable to warming induced stress and additional stressors may exist. Our results show an unexpected widespread tree growth decline in temperate and boreal forests due to warming induced stress but are also suggestive of additional stressors. Rising atmospheric CO2 levels during the past century resulted in consistent increases in water use efficiency, but this did not prevent growth decline. These findings challenge current predictions of increasing terrestrial carbon stocks under climate change scenarios.

  17. Reducing CO2 from shipping – do non-CO2 effects matter?

    Directory of Open Access Journals (Sweden)

    M. S. Eide

    2013-04-01

    Full Text Available Shipping is a growing sector in the global economy, and it contributions to global CO2 emissions are expected to increase. CO2 emissions from the world shipping fleet will likely be regulated in the near future, and studies have shown that significant emission reductions can be achieved at low cost. Regulations are being discussed for both existing ships as well as for future additions to the fleet. In this study a plausible CO2 emission reduction inventory is constructed for the cargo fleet existing in 2010, as well as for container ships, bulk ships and tankers separately. In the reduction inventories, CO2 emissions are reduced by 25–32% relative to baseline by applying 15 technical and operational emission reduction measures in accordance with a ship-type-specific cost-effectiveness criterion, and 9 other emission compounds are changed as a technical implication of reducing CO2. The overall climate and environmental effects of the changes to all 10 emission components in the reduction inventory are assessed using a chemical transport model, radiative forcing (RF models and a simple climate model. We find substantial environmental and health benefits with up to 5% reduction in surface ozone levels, 15% reductions in surface sulfate and 10% reductions in wet deposition of sulfate in certain regions exposed to heavy ship traffic. The major ship types show distinctly different contributions in specific locations. For instance, the container fleet contributes 50% of the sulfate decline on the west coast of North America. The global radiative forcing from a 1 yr emission equal to the difference between baseline and reduction inventory shows an initial strong positive forcing from non-CO2 compounds. This warming effect is due to reduced cooling by aerosols and methane. After approximately 25 yr, the non-CO2 forcing is balanced by the CO2 forcing. For the global mean temperature change, we find a shift from warming to cooling after approximately 60

  18. CO2 capture processes in power plants - Le captage du CO2 dans les centrales thermiques

    CERN Document Server

    Bouallou, Chakib

    2010-01-01

    This review is devoted to assess and compare various processes aiming at recover CO2 from power plants fed with natural gas (NGCC) and pulverized coal (PC). These processes are post combustion CO2 capture using chemical solvents, natural gas reforming for pre-combustion capture and oxy-fuel combustion with cryogenic recovery of CO2. These processes were evaluated to give some clues for choosing the best option for each type of power plant. The comparison of these various concepts suggests that, in the short and medium term, chemical absorption is the most interesting process for NGCC power plants. For CP power plants, oxy-combustion can be a very interesting option, as well as post-combustion capture by chemical solvents.

  19. Reducing CO2 from shipping - do non-CO2 effects matter?

    Science.gov (United States)

    Eide, M. S.; Dalsøren, S. B.; Endresen, Ø.; Samset, B.; Myhre, G.; Fuglestvedt, J.; Berntsen, T.

    2013-04-01

    Shipping is a growing sector in the global economy, and it contributions to global CO2 emissions are expected to increase. CO2 emissions from the world shipping fleet will likely be regulated in the near future, and studies have shown that significant emission reductions can be achieved at low cost. Regulations are being discussed for both existing ships as well as for future additions to the fleet. In this study a plausible CO2 emission reduction inventory is constructed for the cargo fleet existing in 2010, as well as for container ships, bulk ships and tankers separately. In the reduction inventories, CO2 emissions are reduced by 25-32% relative to baseline by applying 15 technical and operational emission reduction measures in accordance with a ship-type-specific cost-effectiveness criterion, and 9 other emission compounds are changed as a technical implication of reducing CO2. The overall climate and environmental effects of the changes to all 10 emission components in the reduction inventory are assessed using a chemical transport model, radiative forcing (RF) models and a simple climate model. We find substantial environmental and health benefits with up to 5% reduction in surface ozone levels, 15% reductions in surface sulfate and 10% reductions in wet deposition of sulfate in certain regions exposed to heavy ship traffic. The major ship types show distinctly different contributions in specific locations. For instance, the container fleet contributes 50% of the sulfate decline on the west coast of North America. The global radiative forcing from a 1 yr emission equal to the difference between baseline and reduction inventory shows an initial strong positive forcing from non-CO2 compounds. This warming effect is due to reduced cooling by aerosols and methane. After approximately 25 yr, the non-CO2 forcing is balanced by the CO2 forcing. For the global mean temperature change, we find a shift from warming to cooling after approximately 60 yr. The major ship

  20. Beyond CO2: Changes in Limiting Resources in California Oak Woodland

    Science.gov (United States)

    Hasselquist, N.; Allen, M.

    2007-12-01

    As atmospheric CO2 continues to increase, other resources become even more limiting to plants and the wildland ecosystems they support. Traditionally, California Mediterranean-type ecosystems are limited by water, then N. In these ecosystems, CO2 enrichment causes a minor increase in production associated with enhanced water-use efficiency, but N rapidly becomes the limiting factor to both production and to soil organism dynamics. In urbanizing areas, such as southern California, strong gradients in NOx deposition are also created by vehicular pollution. We have studied the regulation of N uptake by mycorrhizae in Coast Live Oak (Quercus agrifolia) using information with natural abundance from the early 1900s, current plants and fungi, and modeling change. Contrasts were made from a high NOx deposition site, a low deposition site, and a site where NOx deposition is rapidly increasing. We examined natural abundance δ15 N of current and past plant material (leaves, wood), mycorrhizal and saprobic fungal fruiting bodies, and soil. We modeled relative N uptake, fractionation, and transport between soil, fungus and plant. Our data show complex interactions between increasing NOx deposition and increasing atmospheric CO2 on mycorrhizal-plant interactions. There is a significant shift in N sources and reduction upon mycorrhizae with NOx deposition. However, the elevated CO2 appears to also have created a greater N demand on the trees, increasing dependence on mycorrhizae and the ability of the fungi to acquire organic N and NH4. The individual fungal species differ among sites, but complex trends between fungal genera and trees can be seen. Projections of increasing atmospheric CO2 and regional NOx deposition suggest strong but complex gradients in fungal-oak interactions with decreasing dependence on mycorrhizae near urbanizing areas, mediated by the rate of increasing CO2 and inorganic NOx deposition, and paradoxically, increasing dependency on mycorrhizae and organic

  1. Factors affecting the direct mineralization of CO2 with olivine

    Institute of Scientific and Technical Information of China (English)

    Soonchul Kwon; Maohong Fan; Herbert F. M. DaCosta; Armistead G. Russell

    2011-01-01

    Olivine,one of the most abundant minerals existing in nature,is explored as a CO2 carbonation agent for direct carbonation of CO2 in flue gas.Olivine based CO2 capture is thermodynamically favorable and can form a stable carbonate for long-term storage.Experimental results have shown that water vapor plays an important role in improving CO2 carbonation rate and capacities.Other operation conditions including reaction temperature,initial CO2 concentration,residence time corresponding to the flow rate of CO2 gas stream,and water vapor concentration also considerably affect the performance of the technology.

  2. Factors affecting the direct mineralization of CO2 with olivine.

    Science.gov (United States)

    Kwon, Soonchul; Fan, Maohong; DaCosta, Herbert F M; Russell, Armistead G

    2011-01-01

    Olivine, one of the most abundant minerals existing in nature, is explored as a CO2 carbonation agent for direct carbonation of CO2 in flue gas. Olivine based CO2 capture is thermodynamically favorable and can form a stable carbonate for long-term storage. Experimental results have shown that water vapor plays an important role in improving CO2 carbonation rate and capacities. Other operation conditions including reaction temperature, initial CO2 concentration, residence time corresponding to the flow rate of CO2 gas stream, and water vapor concentration also considerably affect the performance of the technology.

  3. CO2 measurements during transcranial Doppler examinations in headache patients

    DEFF Research Database (Denmark)

    Thomsen, L L; Iversen, Helle Klingenberg

    1994-01-01

    -tidal pCO2 with a capnograph. When patients are nauseated and vomit, as in migraine, the mask or mouthpiece connected to the capnograph represents a problem. We therefore evaluated whether a transcutaneous pCO2 electrode was as useful as the capnograph for pCO2 measurements in TCD examinations. We...... conclude that this is not the case, and recommend capnographic end-tidal pCO2 measurements during TCD examinations. However, transcutaneous pCO2 measurements may represent a supplement to spot measurements of end-tidal pCO2 in stable conditions when long-term monitoring is needed, and the mask...

  4. Supercritical CO2 as a substitute of volatile hydrocarbons; Superkritisch CO2 vervangt vluchtige koolwaterstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Folkerts, G. (ed.)

    2006-05-15

    In many cases supercritical carbon dioxide can replace volatile hydrocarbons in extraction processes. Currently gaseous or liquid CO2 is already used for industrial purification processes, extraction of caffeine from coffee and as a solvent for paint. Although supercritical extraction s a batch process the technique can be applied as a continuous process. [Dutch] In processen waar vluchtige koolwaterstoffen worden ingezet om stoffen te extraheren, biedt superkritisch CO2 een milieuvriendelijk alternatief. Het koolzuur dat zowel in de vloeistof- als gasfase zit, wordt dan ook steeds meer ingezet in extractieprocessen.

  5. Responses of soil CO2 efflux to changes in plant CO2 uptake and transpiration

    Science.gov (United States)

    Balogh, János; de Luca, Giulia; Mészáros, Ádám; Trieber, Júlia; Gecse, Bernadett; Fóti, Szilvia; Pintér, Krisztina; Nagy, Zoltán

    2017-04-01

    Biotic drivers of soil respiration represent a significant supply-side (plant) control of the process. Those biotic drivers that integrate over longer time periods are useful in describing the phenological changes and physiological state of the vegetation, but they are not suitable to explain the diel variability of soil respiration. Two plant physiological processes, acting in opposite directions, could be relevant at diel timescale: (1) photosynthesis, and (2) transpiration. Firstly, it was recently found that photosynthesis has a time-lagged (a few hours) positive effect on the respiration of roots and root-associated microbes. This can be explainedby an increase in easily accessible non-structural hydrocarbon sources for the roots and root-associated organisms within this period. Secondly, it was found that the effect of transpiration could reduce root respiration due to CO2 transport through the transpiration stream, and this effect is expected to be immediate. Removing the effect of the abiotic drivers from the soil efflux signal could help to clarify the role of other driving variables. In the present study, we conducted manipulation measurements in lab environment to be able to detect the effects of the plant physiological variables (CO2 uptake, transpiration) on soil CO2 efflux. Plant individuals were planted into field soil samples in small pots. Transpiration manipulation was done by regulating vapour pressure of the air around the plant canopy and by inhibitors. Photosynthesis manipulation consisted of programmed absence of light. Isotopic signatures of soil respiration were used for estimating the contribution of the autotrophic and heterotrophic soil respiration components. 13CO2 concentration of the CO2 efflux of the different soil components was measured continuously in open system by cavity ring-down spectroscopy (Picarro G1101-i gas analyser). Keeling-plot approach was also used to calculate the isotopic signals of the sources. According to the

  6. Design, manufacture and evaluation of a hydraulically installed, multi-sampling lysimeter. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Scroppo, J.A.; Scroppo, G.L. [Bladon International, Inc., Oak Brook, IL (United States); Carty, R.H.; Chaimberg, M. [Institute of Gas Technology, Chicago, IL (United States); Timmons, R.D.; O`Donnell, M. [Timco Mfg., Inc., Prairie du Sac, WI (United States)

    1992-06-01

    There is a need for a quick, simple, reliable, and inexpensive on-site method for sampling soil pollutants before they reach the groundwater. Vadose zone monitoring is an important aspect of sound groundwater management. In the vadose zone, where water moves via percolation, this water medium possesses the ability to transfer hazardous wastes to the nation`s groundwater system. Obtaining samples of moisture and contaminants from the vadose zone is necessary if potential problems are to be identified before they reach the water table. Accurate determination of spatial distribution, movement, and concentrations of contaminants is essential to the selection of remediation technologies. There is a need for three-dimentional subsurface characterization technologies to identify the location of hazardous plumes and their migration. Current subsurface characterization methods for dispersed contaminants primarily involve a time consuming, expensive process for drilling wells and taking samples. With no major water flow in the vadose zone, conventional monitoring wells will not function as designed. The multi-sampling lysimeter can be readily linked with physical and chemical sensors for on-site screening. The hydraulically-installed suction lysimeter was capable of extracting soil pore liquid samples from unsaturated test soils without the need to predrill a well. Test results verified that the lysimeters installed with a hydraulic or mechanical ram were able to collect soil pore liquid samples in excess of the amount typically required for monitoring and analysis on a daily basis. Modifications to the prototype design eliminated moving parts and the need for inflatable packers. The elimination of the packer system and the use of porous nickel contributed to increased system ruggedness.

  7. Formation of secondary minerals in a lysimeter approach - A mineral-microbe interaction

    Science.gov (United States)

    Schäffner, F.; Merten, D.; De Giudici, G.; Beyer, A.; Akob, D. M.; Ricci, P. C.; Küsel, K.; Büchel, G.

    2012-04-01

    Heavy metal contamination of large areas due to uranium mining operations poses a serious long-term environmental problem. In the Ronneburg district (eastern Thuringia, Germany), leaching of low grade uranium bearing ores (uranium content soil from the field site and pure quartz sand were used as substrates. In general, in situ measurements of redox potentials in the substrates showed highly oxidizing conditions (200-750 mV). Water was supplied to the lysimeter from below via a mariottés bottle containing contaminated groundwater from the field. Evaporation processes were allowed, providing a continuous flow of water. This led to precipitation of epsomite and probably aplowite on the top layer of substrate, similar to what is observed in field investigations. After 4 weeks, the first iron and manganese bearing secondary minerals became visible. Soil water samples were used to monitor the behaviour of metals within the lysimeter. Saturation indices (SI) for different secondary minerals were calculated with PHREEQC. The SI of goethite showed oversaturation with respect to the soil solution. SEM-EDX analyses and IR spectroscopy confirmed the formation of goethite. Geochemical data revealed that goethite formation was mainly dominated by Eh/pH processes and that heavy metals, e.g. Zn and U, could be enriched in this phase. Although Eh/pH data does not support formation of manganese minerals, Mn(II)-oxidizing bacteria (MOB) could be isolated from field soil samples, supporting the fact that microorganisms may influence this natural attenuation process. Laser ablation ICP-MS data reveal accumulation of manganese in MOB biomass on Mn(II)-containing agar plates. Furthermore, it was possible to show the importance of iron on this process, as some MOB isolates were able to oxidize manganese independently from the iron content, whereas some are not. The latter isolates are only able to oxidize manganese if iron is present in the media. In the lysimeter, SEM-EDX data showed

  8. Flow through in situ reactors with suction lysimeter sampling capability and methods of using

    Science.gov (United States)

    Radtke, Corey W [Idaho Falls, ID; Blackwelder, D Brad [Blackfoot, ID; Hubbell, Joel M [Idaho Falls, ID

    2009-11-17

    An in situ reactor for use in a geological strata includes a liner defining a centrally disposed passageway and a sampling conduit received within the passageway. The sampling conduit may be used to receive a geological speciment derived from geological strata therein and a lysimeter is disposed within the sampling conduit in communication with the geological specimen. Fluid may be added to the geological specimen through the passageway defined by the liner, between an inside surface of the liner and an outside surface of the sampling conduit. A distal portion of the sampling conduit may be in fluid communication with the passageway.

  9. Modeling of field lysimeter release data using the computer code dust

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, T.M.; Fitzgerald, I.T. (Brookhaven National Lab., Upton, NY (United States)); McConnell, J.W.; Rogers, R.D. (Idaho National Engineering Lab., Idaho Falls, ID (United States))

    1993-01-01

    In this study, it was attempted to match the experimentally measured mass release data collected over a period of seven years by investigators from Idaho National Engineering Laboratory from the lysimeters at Oak Ridge National Laboratory and Argonne National Laboratory using the computer code DUST. The influence of the dispersion coefficient and distribution coefficient on mass release was investigated. Both were found to significantly influence mass release over the seven year period. It is recommended that these parameters be measured on a site specific basis to enhance the understanding of the system.

  10. Modeling of field lysimeter release data using the computer code dust

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, T.M.; Fitzgerald, I.T. [Brookhaven National Lab., Upton, NY (United States); McConnell, J.W.; Rogers, R.D. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1993-03-01

    In this study, it was attempted to match the experimentally measured mass release data collected over a period of seven years by investigators from Idaho National Engineering Laboratory from the lysimeters at Oak Ridge National Laboratory and Argonne National Laboratory using the computer code DUST. The influence of the dispersion coefficient and distribution coefficient on mass release was investigated. Both were found to significantly influence mass release over the seven year period. It is recommended that these parameters be measured on a site specific basis to enhance the understanding of the system.

  11. Verification SEBAL and Hargreaves –Samani Models to Estimate Evapotranspiration by Lysimeter Data

    Directory of Open Access Journals (Sweden)

    Ali Morshedi

    2017-02-01

    Full Text Available Introduction: Evapotranspiration (ET is an important component of the hydrological cycle, energy equations at the surface and water balance. ET estimation is needed in various fields of science, such as hydrology, agriculture, forestry and pasture, and water resources management. Conventional methods used to estimate evapotranspiration from point measurements. Remote sensing models have the capability to estimate ET using surface albedo, surface temperature and vegetation indices in larger scales. Surface Energy Balance Algorithm for Land (SEBAL estimate ET at the moment of satellite path as a residual of energy balance equation for each pixel. In this study Hargreaves-Samani (HS and SEBAL models ET compared to an alfalfa lysimeter data’s, located in Shahrekord plain within the Karun basin. Satellite imageries were based on Landsat 7 ETM+ sensor data’s in seven satellite passes for path 164 and row 38 in the World Reference System, similar to lysimeter sampling data period, from April to October 2011. SEBAL uses the energy balance equation to estimate evapotranspiration. Equation No. 1 shows the energy balance equation for an evaporative surface: λET=Rn–G–H [1] In this equation Rn, H, G and λET represent the net radiation flux input to the surface (W/m2, Sensible heat flux (W/m2, soil heat flux (W/m2, and latent heat of vaporization (W/m2, respectively. In this equation the vertical flux considered and the horizontal fluxes of energy are neglected. The above equation must be used for large surfaces and uniformly full cover plant area. SEBAL is provided for estimating ET, using the minimum data measured by ground equipment. This model is applied and tested in more than 30 countries with an accuracy of about 85% at field scale, and 95 percent in the daily and seasonal scales. In Borkhar watershed (East of Isfahan, IRAN ASTER and MODIS satellite imageries were used for SEBAL to compare Penman-Monteith model. Results showed that estimated

  12. 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...

  13. CO2 Sequestration and Recycle by Photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Steven S.C. Chuang

    2004-02-01

    Visible light-photocatalysis could provide a cost-effective route to recycle CO2 to useful chemicals or fuels. Research is planned to study the reactivity of adsorbates, their role in the photosynthesis reaction, and their relation to the nature of surface sites during photosynthesis of methanol and hydrocarbons from CO{sub 2}/H{sub 2}O. The year two research focus catalyst screening and IR studies. Key research results show Pd/TiO2 exhibits the highest activity for hydrocarbon synthesis from photocatalytic reactions. The in situ IR could successfully monitor the adsorbate hydrocarbon species on Cu/TiO2. Year III research will focus on developing a better understanding of the key factors which control the catalyst activity.

  14. Beam profile analyzer for CO2 lasers

    Directory of Open Access Journals (Sweden)

    Rubén López

    2015-12-01

    Full Text Available The development of an optoelectronic system to analyze the beam intensity profile of CO2 lasers is presented herein. The device collects the beam profile with a LiTaO3 pyroelectric detector and uses a sampling technique based on the acquisition of horizontal sections at different levels. The digital signal processing includes subroutines that drop down two dimensional and three dimensional beam profile displays to determine the laser beam parameters of optical power, peak pixel location, centroid location and width of the laser beam, with algorithms based on the ISO 11146 standard. With the systematic calibration of the analyzer was obtained in the measurement of power an error under 5%, for a 20–200 W range and an error under 1.6% for spatial measurements of a TEM00 laser. By design, the analyzer can be used during the laser process.

  15. 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.

  16. CO2 chemoreception in cardiorespiratory control.

    Science.gov (United States)

    Putnam, Robert W

    2010-06-01

    Considerable progress has been made elucidating the cellular signals and ion channel targets involved in the response to increased CO2/H+ of brain stem neurons from chemosensitive regions. Intracellular pH (pHi) does not exhibit recovery from an acid load when extracellular pH (pHo) is also acid. This lack of pHi recovery is an essential but not unique feature of all chemosensitive neurons. These neurons have pH-regulating transporters, especially Na+/H+ exchangers, but some may also contain HCO3--dependent transporters as well. Studies in locus ceruleus (LC) neurons have shown that firing rate will increase in response to decreased pHi or pHo but not in response to increased CO2 alone. A number of K+ channels, as well as other channels, have been suggested to be targets of these pH changes with a fall of pH inhibiting these channels. In neurons from some regions it appears that multiple signals and multiple channels are involved in their chemosensitive response while in neurons from other regions a single signal and/or channel may be involved. Despite the progress, a number of key issues remain to be studied. A detailed study of chemosensitive signaling needs to be done in neurons from more brain stem regions. Fully describing the chemosensitive signaling pathways in brain stem neurons will offer new targets for therapies to alter the strength of central chemosensitivity and will yield new insights into the reason why there are multiple central chemoreceptive sites.

  17. Enhanced transport phenomena in CO2 sequestration and CO2 EOR

    NARCIS (Netherlands)

    Farajzadeh, R.

    2009-01-01

    The results of this thesis give insight into the (mass)-transfer during flow of gases, especially CO2, in various gas-liquid systems. A number of experiments was performed to investigate the transport phenomena through interfaces with and without surfactant monolayers. The observed phenomena have be

  18. Industrial CO2 Removal: CO2 Capture from Ambient Air and Geological Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Dooley, James J.

    2011-06-08

    This abstract and its accompanying presentation will provide an overview of two distinct industrial processes for removing carbon dioxide (CO2) from the atmosphere as a means of addressing anthropogenic climate change. The first of these is carbon dioxide capture and storage (CCS) coupled with large scale biomass production (hereafter referred to as bioCCS). The second is CO2 capture from ambient air via industrial systems (hereafter referred to as direct air capture (DAC)). In both systems, the captured CO2 would be injected into deep geologic formations so as to isolate it from the atmosphere. The technical literature is clear that both of these technologies are technically feasible as of today (IPCC, 2005; Keith, 2009; Lackner, 2009; Luckow et al., 2010; Ranjan and Herzog, 2011). What is uncertain is the relative cost of these industrial ambient-air CO2 removal systems when compared to other emissions mitigation measures, the ultimate timing and scale of their deployment, and the resolution of potential site specific constraints that would impact their ultimate commercial deployment.

  19. CO2-ECBM and CO2 Sequestration in Polish Coal Seam – Experimental Study

    Directory of Open Access Journals (Sweden)

    Paweł Baran

    2014-01-01

    Originality/value: The results indicate successful sorption of carbon dioxide in each experiment. This provides the rationale to study the application of the coal tested to obtain methane genetic origin genetic methane with the use of the CO2 injection.

  20. Enhanced transport phenomena in CO2 sequestration and CO2 EOR

    NARCIS (Netherlands)

    Farajzadeh, R.

    2009-01-01

    The results of this thesis give insight into the (mass)-transfer during flow of gases, especially CO2, in various gas-liquid systems. A number of experiments was performed to investigate the transport phenomena through interfaces with and without surfactant monolayers. The observed phenomena have be

  1. Enhanced transport phenomena in CO2 sequestration and CO2 EOR

    NARCIS (Netherlands)

    Farajzadeh, R.

    2009-01-01

    The results of this thesis give insight into the (mass)-transfer during flow of gases, especially CO2, in various gas-liquid systems. A number of experiments was performed to investigate the transport phenomena through interfaces with and without surfactant monolayers. The observed phenomena have

  2. Novel Long-Term CO2 Removal System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Current Technology for CO2 removal from enclosed air of spacecraft utilizes LiOH canisters for CO2 absorption. This absorption is irreversible so longer flights...

  3. Monitoring solid oxide CO2 capture sorbents in action.

    Science.gov (United States)

    Keturakis, Christopher J; Ni, Fan; Spicer, Michelle; Beaver, Michael G; Caram, Hugo S; Wachs, Israel E

    2014-12-01

    The separation, capture, and storage of CO2 , the major greenhouse gas, from industrial gas streams has received considerable attention in recent years because of concerns about environmental effects of increasing CO2 concentration in the atmosphere. An emerging area of research utilizes reversible CO2 sorbents to increase conversion and rate of forward reactions for equilibrium-controlled reactions (sorption-enhanced reactions). Little fundamental information, however, is known about the nature of the sorbent surface sites, sorbent surface-CO2 complexes, and the CO2 adsorption/desorption mechanisms. The present study directly spectroscopically monitors Na2 O/Al2 O3 sorbent-CO2 surface complexes during adsorption/desorption with simultaneous analysis of desorbed CO2 gas, allowing establishment of molecular level structure-sorption relationships between individual surface carbonate complexes and the CO2 working capacity of sorbents at different temperatures.

  4. Understanding and predicting trends in north Atlantic CO2 uptake

    Science.gov (United States)

    Halloran, Paul; Lebehot, Alice; Watson, Andy; McNeall, Doug; Ford, David; Schuster, Ute

    2017-04-01

    To determine the maximum carbon dioxide (CO2) emissions society must commit to, to remain below a given atmospheric CO2 threshold, the scientific community must robustly quantify what proportion of human emitted CO2 will be taken up by the land and marine carbon reservoirs. The North Atlantic Ocean is the most intense marine sink of anthropogenic CO2 on the planet, accounting for about a fifth of the global oceanic anthropogenic CO2 uptake, despite covering just 15% of the global ocean area. Carefully assessing uncertainties, we quantify the real-world trend in North Atlantic CO2 uptake over the past two decades. Comparing this to results from state-of-the-art climate models, we find that models are systematically underestimating the observed CO2 uptake trend. By performing a set of targeted climate model simulations, we diagnose and account for this bias, and produce the first set of observation-informed future ocean CO2 uptake predictions.

  5. Photosynthetic and Molecular Markers of CO2-mediated Photosynthetic Downregulation in Nodulated Alfalfa

    Institute of Scientific and Technical Information of China (English)

    (A)lvaro Sanz-Sáez; Gorka Erice; Iker Aranjuelo; Ricardo Aroca; Juan Manuel Ruíz-Lozano; Jone Aguirreolea; Juan José Irigoyen

    2013-01-01

    Elevated CO2 leads to a decrease in potential net photosynthesis in long-term experiments and thus to a reduction in potential growth.This process is known as photosynthetic downregulation.There is no agreement on the definition of which parameters are the most sensitive for detecting CO2 acclimation.In order to investigate the most sensitive photosynthetic and molecular markers of CO2 acclimation,the effects of elevated CO2,and associated elevated temperature were analyzed in alfalfa plants inoculated with different Sinorhizobium meliloti strains.Plants (Medicago sativa L.cv.Aragón) were grown in summer or autumn in temperature gradient greenhouses (TGG).At the end of the experiment,all plants showed acclimation in both seasons,especially under elevated summer temperatures.This was probably due to the lower nitrogen (N) availability caused by decreased N2-fixation under higher temperatures.Photosynthesis measured at growth CO2 concentration,rubisco in vitro activity and maximum rate of carboxylation were the most sensitive parameters for detecting downregulation.Severe acclimation was also related with decreases in leaf nitrogen content associated with declines in rubisco content (large and small subunits) and activity that resulted in a drop in photosynthesis.Despite the sensitivity of rubisco content as a marker of acclimation,it was not coordinated with gene expression,possibly due to a lag between gene transcription and protein translation.

  6. Determining CO2-brine relative permeability and capillary pressure simultaneously: an insight to capillary entrance and end effects

    Science.gov (United States)

    Chen, X.; Kianinejad, A.; DiCarlo, D. A.

    2014-12-01

    CO2-brine relative permeability relations are important parameters in modeling scenarios such as CO2 sequestration in saline aquifers and CO2 enhanced recovery in oil reservoir. Many steady-state experimental studies on CO2-brine relative permeability showed that the CO2-brine relative permeability differs greatly from typical oil-brine relative permeability. Particularly, they reported a very small endpoint CO2 relative permeability of 0.1~0.2 at a relative high residual water saturation of 0.4~0.6. In this study, we hypothesize the measured low endpoint CO2 relative permeability in previous studies was an experimental artifact that is primary due to low CO2 viscosity. We conducted steady-state CO2 drainage experiments by co-injecting equlibrated CO2 and brine into a long (60.8 cm) and low permeability (116-mD) Berea sandstone core at 20 °C and 1500 psi. During every experiment, both the overall pressure drop across the core and the pressure drops of the five independent and continuous sections of the core were monitored. The in-situ saturation was measured with a medical X-ray Computed Tomography (CT) scanner. In the center three sections where saturation was uniform, we determined the relative permeability to both brine and CO2 phases. In the entrance and exit sections, both measured pressure gradients and saturation were non-uniform. To cope with this, we make several self-consistent assumptions that reveal the nature of capillary entrance and effect in steady-state two-phase core flooding experiments. Based on these assumptions we determined the relative permeability to CO2 and CO2-brine capillary pressure simultaneously using measured pressure drops. We found: (1) a much higher endpoint CO2 relative permeability of 0.58 at a water saturation of 48%, (2) the entrance region with non-uniform saturation expanded CO2 relative permeability data to much lower water saturation, (3) the determined CO2-brine capillary pressure curve is self-consistent and matches

  7. Microbial community response to the CO2 injection and storage in the saline aquifer, Ketzin, Germany

    Science.gov (United States)

    Morozova, Daria; Zettlitzer, Michael; Vieth, Andrea; Würdemann, Hilke

    2010-05-01

    Gradient Gel Electrophoresis (PCR-DGGE), we have shown that the microbial community was strongly influenced by CO2 injection. Before CO2 arrival, up to 6x106 cells ml-1 were detected by DAPI-staining at a depth of 647 m below the surface. The microbial community was dominated by the domain Bacteria, with Proteobacteria and Firmicutes as the most abundant phyla. Representatives of the sulphate-reducing bacteria, extremophilic and fermenting bacteria were identified. After CO2 injection, our study revealed temporal outcompetition of sulphate-reducing bacteria by methanogenic archaea. In addition, an enhanced activity of the microbial population after five months CO2 storage indicated that the bacterial community was able to adapt to the extreme conditions of the deep biosphere and to the extreme changes of these conditions. In order to draw broader conclusions about the microbial community in the deep biosphere, more intensive sampling and methodologies are necessary. The limiting factors such as high expenses of the downhole sampling and time-consuming analyses should be taken into consideration. This study can thus provide only an early insight into the community structure and its changes due to the CO2 injection. Further studies on the activity, quantity and physiology of these microbial communities using molecular cloning and real-time PCR are in progress.

  8. Lipid accumulation and CO2 utilization of Nannochloropsis oculata in response to CO2 aeration.

    Science.gov (United States)

    Chiu, Sheng-Yi; Kao, Chien-Ya; Tsai, Ming-Ta; Ong, Seow-Chin; Chen, Chiun-Hsun; Lin, Chih-Sheng

    2009-01-01

    In order to produce microalgal lipids that can be transformed to biodiesel fuel, effects of concentration of CO(2) aeration on the biomass production and lipid accumulation of Nannochloropsis oculata in a semicontinuous culture were investigated in this study. Lipid content of N. oculata cells at different growth phases was also explored. The results showed that the lipid accumulation from logarithmic phase to stationary phase of N. oculata NCTU-3 was significantly increased from 30.8% to 50.4%. In the microalgal cultures aerated with 2%, 5%, 10% and 15% CO(2), the maximal biomass and lipid productivity in the semicontinuous system were 0.480 and 0.142 g L(-1)d(-1) with 2% CO(2) aeration, respectively. Even the N. oculata NCTU-3 cultured in the semicontinuous system aerated with 15% CO(2), the biomass and lipid productivity could reach to 0.372 and 0.084 g L(-1)d(-1), respectively. In the comparison of productive efficiencies, the semicontinuous system was operated with two culture approaches over 12d. The biomass and lipid productivity of N. oculata NCTU-3 were 0.497 and 0.151 g L(-1)d(-1) in one-day replacement (half broth was replaced each day), and were 0.296 and 0.121 g L(-1)d(-1) in three-day replacement (three fifth broth was replaced every 3d), respectively. To optimize the condition for long-term biomass and lipid yield from N. oculata NCTU-3, this microalga was suggested to grow in the semicontinuous system aerated with 2% CO(2) and operated by one-day replacement.

  9. CO2 emissions from Super-light Structures

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Bagger, Anne

    2011-01-01

    rise to a substantial reduction of the CO2 emission in the construction phase. The present paper describes how the CO2 emission is reduced when using Super-light technology instead of traditional structural components. Estimations of the CO2 emissions from a number of projects using various...... construction methods suggest that building with Super-light structures may cut the CO2 emission in half, compared to traditional concrete structures, and reduce it to 25% compared to traditional steel structures....

  10. Simulation of CO2-Distribution in Fractured Oil Reservoir

    OpenAIRE

    Furuvik, Nora; Halvorsen, Britt

    2015-01-01

    Deep geologic injections and storage of Carbon dioxide (CO2) for enhanced oil recovery (EOR) are an upcoming combination due to the potential for increased oil production from depleted oilfields at the same time reducing the carbon footprint from industrial sources. CO2-EOR refers to a technique for injection of supercritical-dense CO2 into an oil reservoir. Remaining oil, not producible by primary and secondary techniques, has been successfully produced using EOR with CO2 since early 1970??....

  11. Time-course of ventilation, arterial and pulmonary CO(2) tension during CO (2) increase in humans.

    Science.gov (United States)

    Satoh, Toru; Okada, Yasumasa; Hara, Yasushi; Sakamaki, Fumio; Kyotani, Shingo; Tomita, Takeshi; Nagaya, Noritoshi; Nakanishi, Norifumi

    2012-01-01

    A change of ventilation (VE), PaCO( 2 ) (arterial CO( 2 ) tension) and PvCO( 2 ) (pulmonary arterial CO( 2 ) tension) with time was not evaluated precisely during exercise or CO( 2 ) rebreathing in humans. In this study, changes of these variables with time were fitted to exponential curves {y = Exp ( x/ T + A ) + k} and compared. When exercise pulmonary hemodynamics was examined in 15 cardiac patients to decide therapies, we asked the patients to undergo CO( 2 ) rebreathing using air with supplementation of consumed O( 2 ). Arterial and pulmonary blood was drawn every minute. During exercise, T was 28.2 ± 8.4 and 26.8 ± 12.4, and A was 0.80 ± 0.50 and 0.50 ± 0.90 in VE and PvCO( 2 ), respectively, with no statistical differences. During CO( 2 ) rebreathing, T was 18.6 ± 5.8, 41.8 ± 38.0 and 21.6 ± 9.7 and A was 0.39 ± 0.67, 1.64 ± 1.35 and 0.17 ± 0.83 in VE, PaCO( 2 ) and PvCO( 2 ), respectively, with statistical difference of PaCO( 2 ) from other variables, suggesting that VE and PvCO( 2 ) showed same mode of change according to time but PaCO( 2 ) did not.

  12. CO2-adapted legumes ameliorate but do not prevent the negative effect of elevated CO2 on nitrogen fixation

    Science.gov (United States)

    Newton, P.; Bowatte, S.; Lieffering, M.; Li, F.

    2015-12-01

    The response of biological nitrogen fixation (BNF) to climate and elevated CO2 (eCO2) is a key uncertainty in modelling C cycle projections. In addition, as BNF provides 50% of the nitrogen (N) input to agricultural production and as ecosystem responses to eCO2 are strongly influenced by N availability then the eCO2 impact on BNF is central to modelling legume-based system responses to climate change. Greater photoassimilate production under eCO2 should lead to enhanced BNF and this response is a feature of ecosystem models thus providing the N inputs necessary to provide continuing stimulation of NPP. FACE experiments provide a 'realistic' environment for eCO2 studies; however, even if run for multiple years, they still may not capture adaptation to eCO2 particularly in ecosystems dominated by perennial species. We tested the effect of eCO2 on BNF and the potential importance of adaption by growing legumes that had been exposed to high or ambient CO2 concentrations at a natural CO2 spring in a long-running (16 year) FACE experiment on grassland. BNF was significantly lower under eCO2 but the reduction was less marked where plants had originated in a high CO2 environment. An ecosystem model run with reduced BNF proved a better fit to the experimental data for the FACE experiment than where BNF was enhanced or unchanged under eCO2.

  13. Activation of CO2 by phosphinoamide hafnium complexes.

    Science.gov (United States)

    Sgro, Michael J; Stephan, Douglas W

    2013-04-04

    Hf-phosphinoamide cation complexes behave as metal-based frustrated Lewis pairs and bind one or two equivalent of CO2 and in as well can activate CO2 in a bimetallic fashion to give a pseudo-tetrahedral P2CO2 fragment linking two Hf centres.

  14. A general method for calculating subsurface CO2 storage capacity

    NARCIS (Netherlands)

    Meer, L.G.H. van der; Egberts, P.J.P.

    2008-01-01

    In the past, lists of potential CO2 storage locations have been compiled purely on the basis of the capacity of the locations in terms of their CO2 solubility. However, in some of these locations, the injection of CO2 is commercially unfeasible because of their small average permeability. During the

  15. A liquid CO2-compatible hydrocarbon surfactant: experiment and modelling

    NARCIS (Netherlands)

    Banerjee, S.; Kleijn, J.M.; Cohen Stuart, M.A.; Leermakers, F.A.M.

    2013-01-01

    Surfactants soluble in liquid CO2 are rare and knowledge on interfacial and self-assembly behaviour is fragmented. We found that polyoxyethylene (5) isooctylphenyl ether is interfacially active at the water–liquid CO2 interface. Water–liquid CO2 interfacial tension was measured at various surfactant

  16. Impacts: economic trade-offs for CO2 impurity specification

    NARCIS (Netherlands)

    Eickhoff, C.; Neele, F.P.; Hammer, M.; DiBiagio, M.; Hofstee, C.; Koenen, M.; Fischer, S.; Isaenko, A.; Brown, A.; Kovacs, T.

    2014-01-01

    The IMPACTS project has a stated broad objective to develop the knowledge base of CO2 quality required for establishing norms and regulations to ensure safe and reliable design, construction and operation of CO2 pipelines and injection equipment, and safe long-term geological storage of CO2. More sp

  17. Suppression of CO2-plasticization by semiinterpenetrating polymer network formation

    NARCIS (Netherlands)

    Bos, A.; Pünt, I.G.M.; Wessling, M.; Strathmann, H.

    1998-01-01

    CO2-induced plasticization may significantly spoil the membrane performance in high-pressure CO2/CH4 separations. The polymer matrix swells upon sorption of CO2, which accelerates the permeation of CH4. The polymer membrane looses its selectivity. To make membranes attractive for, for example, natur

  18. Suppression of CO2-plasticization by semiinterpenetrating polymer network formation

    NARCIS (Netherlands)

    Bos, A.; Punt, Ineke G.M.; Wessling, Matthias; Strathmann, H.

    1998-01-01

    CO2-induced plasticization may significantly spoil the membrane performance in high-pressure CO2/CH4 separations. The polymer matrix swells upon sorption of CO2, which accelerates the permeation of CH4. The polymer membrane looses its selectivity. To make membranes attractive for, for example, natur

  19. Modeling of CO2 absorber using an AMP solution

    DEFF Research Database (Denmark)

    Gabrielsen, Jostein; Michelsen, Michael Locht; Stenby, Erling Halfdan

    2006-01-01

    Abstract: An explicit model for carbon dioxide (CO2) solubility in an aqueous solution of 2-amino-2-methyl-1-propanol (AMP) has been proposed and an expression for the heat of absorption of CO2 has been developed as a function of loading and temperature. A rate-based steady-state model for CO2 ab...

  20. A general method for calculating subsurface CO2 storage capacity

    NARCIS (Netherlands)

    Meer, L.G.H. van der; Egberts, P.J.P.

    2008-01-01

    In the past, lists of potential CO2 storage locations have been compiled purely on the basis of the capacity of the locations in terms of their CO2 solubility. However, in some of these locations, the injection of CO2 is commercially unfeasible because of their small average permeability. During the

  1. Suppression of CO2-plasticization by semiinterpenetrating polymer network formation

    NARCIS (Netherlands)

    Bos, A.; Punt, Ineke G.M.; Wessling, Matthias; Strathmann, H.

    1998-01-01

    CO2-induced plasticization may significantly spoil the membrane performance in high-pressure CO2/CH4 separations. The polymer matrix swells upon sorption of CO2, which accelerates the permeation of CH4. The polymer membrane looses its selectivity. To make membranes attractive for, for example,

  2. Ventilation in Sewers Quantified by Measurements of CO2

    DEFF Research Database (Denmark)

    Fuglsang, Emil Dietz; Vollertsen, Jes; Nielsen, Asbjørn Haaning

    2012-01-01

    H, alkalinity and sewer-air CO2 concentrations. An intercepting sewer was studied and an average sewer-air retention time of approximately 1.5-2.5 hours was found at CO2 levels around 4-6 times the natural background. Also an upstream sub-catchment was studied. In this part of the sewer system the level of CO2...

  3. Applied stress reduces the CO2 sorption capacity of coal

    NARCIS (Netherlands)

    Hol, S.; Peach, C.J.; Spiers, C.J.

    2011-01-01

    Though the adsorption of CO2 by coal has been extensively studied in experiments, few systematic studies have been done on the effects of the stress state within the coal on CO2 sorption. To investigate whether or not the CO2 sorption capacity of coal is influenced by the application of an effective

  4. SUBSURFACE PROPERTY RIGHTS: IMPLICATIONS FOR GEOLOGIC CO2 STORAGE

    Science.gov (United States)

    The paper discusses subsurface property rights as they apply to geologic sequestration (GS) of carbon dioxide (CO2). GS projects inject captured CO2 into deep (greater than ~1 km) geologic formations for the explicit purpose of avoiding atmospheric emission of CO2. Because of the...

  5. SUBSURFACE PROPERTY RIGHTS: IMPLICATIONS FOR GEOLOGIC CO2 SEQUESTRATION

    Science.gov (United States)

    The chapter discusses subsurface property rights as they apply to geologic sequestration (GS) of carbon dioxide (CO2). GS projects inject captured CO2 into deep (greater than ~1 km) geologic formations for the explicit purpose of avoiding atmospheric emission of CO2. Because of t...

  6. SUBSURFACE PROPERTY RIGHTS: IMPLICATIONS FOR GEOLOGIC CO2 SEQUESTRATION (PRESENTATION)

    Science.gov (United States)

    The paper discusses subsurface property rights as they apply to geologic sequestration (GS) of carbon dioxide (CO2). GS projects inject captured CO2 into deep (greater than ~1 km) geologic formations for the explicit purpose of avoiding atmospheric emission of CO2. Because of the...

  7. An attempt at estimating Paris area CO2 emissions from atmospheric concentration measurements

    Science.gov (United States)

    Bréon, F. M.; Broquet, G.; Puygrenier, V.; Chevallier, F.; Xueref-Remy, I.; Ramonet, M.; Dieudonné, E.; Lopez, M.; Schmidt, M.; Perrussel, O.; Ciais, P.

    2015-02-01

    Atmospheric concentration measurements are used to adjust the daily to monthly budget of fossil fuel CO2 emissions of the Paris urban area from the prior estimates established by the Airparif local air quality agency. Five atmospheric monitoring sites are available, including one at the top of the Eiffel Tower. The atmospheric inversion is based on a Bayesian approach, and relies on an atmospheric transport model with a spatial resolution of 2 km with boundary conditions from a global coarse grid transport model. The inversion adjusts prior knowledge about the anthropogenic and biogenic CO2 fluxes from the Airparif inventory and an ecosystem model, respectively, with corrections at a temporal resolution of 6 h, while keeping the spatial distribution from the emission inventory. These corrections are based on assumptions regarding the temporal autocorrelation of prior emissions uncertainties within the daily cycle, and from day to day. The comparison of the measurements against the atmospheric transport simulation driven by the a priori CO2 surface fluxes shows significant differences upwind of the Paris urban area, which suggests a large and uncertain contribution from distant sources and sinks to the CO2 concentration variability. This contribution advocates that the inversion should aim at minimising model-data misfits in upwind-downwind gradients rather than misfits in mole fractions at individual sites. Another conclusion of the direct model-measurement comparison is that the CO2 variability at the top of the Eiffel Tower is large and poorly represented by the model for most wind speeds and directions. The model's inability to reproduce the CO2 variability at the heart of the city makes such measurements ill-suited for the inversion. This and the need to constrain the budgets for the whole city suggests the assimilation of upwind-downwind mole fraction gradients between sites at the edge of the urban area only. The inversion significantly improves the agreement

  8. Extreme CO2 disturbance and the resilience of soil microbial communities

    Science.gov (United States)

    McFarland, Jack W.; Waldrop, Mark P.; Haw, Monica

    2013-01-01

    Carbon capture and storage (CSS) technology has the potential to inadvertently release large quantities of CO2 through geologic substrates and into surrounding soils and ecosystems. Such a disturbance has the potential to not only alter the structure and function of plant and animal communities, but also soils, soil microbial communities, and the biogeochemical processes they mediate. At Mammoth Mountain, we assessed the soil microbial community response to CO2 disturbance (derived from volcanic ‘cold’ CO2) that resulted in localized tree kill; soil CO2 concentrations in our study area ranged from 0.6% to 60%. Our objectives were to examine how microbial communities and their activities are restructured by extreme CO2 disturbance, and assess the response of major microbial taxa to the reintroduction of limited plant communities following an extensive period (15–20 years) with no plants. We found that CO2-induced tree kill reduced soil carbon (C) availability along our sampling transect. In response, soil microbial biomass decreased by an order of magnitude from healthy forest to impacted areas. Soil microorganisms were most sensitive to changes in soil organic C, which explained almost 60% of the variation for microbial biomass C (MBC) along the CO2gradient. We employed phospholipid fatty acid analysis and quantitative PCR (qPCR) to determine compositional changes among microbial communities in affected areas and found substantial reductions in microbial biomass linked to the loss of soil fungi. In contrast, archaeal populations responded positively to the CO2 disturbance, presumably due to reduced competition of bacteria and fungi, and perhaps unique adaptations to energy stress. Enzyme activities important in the cycling of soil C, nitrogen (N), and phosphorus (P) declined with increasing CO2, though specific activities (per unit MBC) remained stable or increased suggesting functional redundancy among restructured communities. We conclude that both the

  9. Greenhouse gas simulations with a coupled meteorological and transport model: the predictability of CO2

    Science.gov (United States)

    Polavarapu, Saroja M.; Neish, Michael; Tanguay, Monique; Girard, Claude; de Grandpré, Jean; Semeniuk, Kirill; Gravel, Sylvie; Ren, Shuzhan; Roche, Sébastien; Chan, Douglas; Strong, Kimberly

    2016-09-01

    A new model for greenhouse gas transport has been developed based on Environment and Climate Change Canada's operational weather and environmental prediction models. When provided with realistic posterior fluxes for CO2, the CO2 simulations compare well to NOAA's CarbonTracker fields and to near-surface continuous measurements, columns from the Total Carbon Column Observing Network (TCCON) and NOAA aircraft profiles. This coupled meteorological and tracer transport model is used to study the predictability of CO2. Predictability concerns the quantification of model forecast errors and thus of transport model errors. CO2 predictions are used to compute model-data mismatches when solving flux inversion problems and the quality of such predictions is a major concern. Here, the loss of meteorological predictability due to uncertain meteorological initial conditions is shown to impact CO2 predictability. The predictability of CO2 is shorter than that of the temperature field and increases near the surface and in the lower stratosphere. When broken down into spatial scales, CO2 predictability at the very largest scales is mainly due to surface fluxes but there is also some sensitivity to the land and ocean surface forcing of meteorological fields. The predictability due to the land and ocean surface is most evident in boreal summer when biospheric uptake produces large spatial gradients in the CO2 field. This is a newly identified source of uncertainty in CO2 predictions but it is expected to be much less significant than uncertainties in fluxes. However, it serves as an upper limit for the more important source of transport error and loss of predictability, which is due to uncertain meteorological analyses. By isolating this component of transport error, it is demonstrated that CO2 can only be defined on large spatial scales due to the presence of meteorological uncertainty. Thus, for a given model, there is a spatial scale below which fluxes cannot be inferred simply

  10. Sensory Transduction of the CO2 Response of Guard Cells

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Eduardo Zeiger

    2003-06-30

    Stomata have a key role in the regulation of gas exchange and intercellular CO2 concentrations of leaves. Guard cells sense internal and external signals in the leaf environment and transduce these signals into osmoregulatory processes that control stomatal apertures. This research proposal addresses the characterization of the sensory transduction of the CO2 signal in guard cells. Recent studies have shown that in Vicia leaves kept at constant light and temperature in a growth chamber, changes in ambient CO2 concentrations cause large changes in guard cell zeaxanthin that are linear with CO2-dependent changes in stomatal apertures. Research proposed here will test the hypothesis that zeaxanthin function as a transducer of CO2 signals in guard cells. Three central aspects of this hypothesis will be investigated: CO2 sensing by the carboxylation reaction of Rubisco in the guard cell chloroplast, which would modulate zeaxanthin concentrations via changes in lumen pH; transduction of the CO2 signal by zeaxanthin via a transducing cascade that controls guard cell osmoregulation; and blue light dependence of the CO2 signal transduction by zeaxanthin, required for the formation of an isomeric form of zeaxanthin that is physiologically active as a transducer. The role of Rubisco in CO2 sensing will be investigated in experiments characterizing the stomatal response to CO2 in the Arabidopsis mutants R100 and rca-, which have reduced rates of Rubisco-dependent carboxylation. The role of zeaxanthin as a CO2 transducer will be studied in npq1, a zeaxanthin-less mutant. The blue light-dependence of CO2 sensing will be studied in experiments characterizing the stomatal response to CO2 under red light. Arabidopsis mutants will also be used in further studies of an acclimation of the stomatal response to CO2, and a possible role of the xanthophyll cycle of the guard cell chloroplast in acclimations of the stomatal response to CO2. Studies on the osmoregulatory role of sucrose in

  11. Gradient networks

    Science.gov (United States)

    Toroczkai, Zoltán; Kozma, Balázs; Bassler, Kevin E.; Hengartner, N. W.; Korniss, G.

    2008-04-01

    Gradient networks are defined (Toroczkai and Bassler 2004 Nature 428 716) as directed graphs formed by local gradients of a scalar field distributed on the nodes of a substrate network G. We present the derivation for some of the general properties of gradient graphs and give an exact expression for the in-degree distribution R(l) of the gradient network when the substrate is a binomial (Erd{\\;\\kern -0.10em \\raise -0.35ex \\{{^{^{\\prime\\prime}}}}\\kern -0.57em \\o} s-Rényi) random graph, G_{N,p} , and the scalars are independent identically distributed (i.i.d.) random variables. We show that in the limit N \\to \\infty, p \\to 0, z = pN = \\mbox{const} \\gg 1, R(l)\\propto l^{-1} for l Bassler (2004 Nature 428 716).

  12. Transport of europium colloids in vadose zone lysimeters at the semiarid Hanford site.

    Science.gov (United States)

    Liu, Ziru; Flury, Markus; Zhang, Z Fred; Harsh, James B; Gee, Glendon W; Strickland, Chris E; Clayton, Ray E

    2013-03-05

    The objective of this study was to quantify transport of Eu colloids in the vadose zone at the semiarid Hanford site. Eu-hydroxy-carbonate colloids, Eu(OH)(CO3), were applied to the surface of field lysimeters, and migration of the colloids through the sediments was monitored using wick samplers. The lysimeters were exposed to natural precipitation (145-231 mm/year) or artificial irrigation (124-348 mm/year). Wick outflow was analyzed for Eu concentrations, supplemented by electron microscopy and energy-dispersive X-ray analysis. Small amounts of Eu colloids (colloids under both natural precipitation and artificial irrigation; that is, the leading edge of the Eu colloids moved at a velocity of 3 cm/day within the first 2 months after application. Episodic infiltration (e.g., Chinook snowmelt events) caused peaks of Eu in the wick outflow. While a fraction of Eu moved consistent with long-term recharge estimates at the site, the main mass of Eu remained in the top 30 cm of the sediments. This study illustrates that, under field conditions, near-surface colloid mobilization and transport occurred in Hanford sediments.

  13. Device for applying organic chemicals to lysimeter surfaces; Applikationsvorrichtung fuer organische Chemikalien auf Lysimeteroberflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Schroll, R. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Bodenoekologie

    1999-02-01

    One of the aims of environmental research at the GSF Research Centre for the Environment and Health is to determine the behaviour of environmentally consequential chemicals in terrestrial ecosystems under as natural conditions as possible. The GSF lysimeter plant in Neuherberg permits studying the environmental behaviour of organic chemicals in different soils. Collaborators at GSF have developed a means of applying -14-marked substances in field lysimeters so as to be able to refind released chemicals, identify their conversion products and set up mass balances for the chemicals. [Deutsch] Ein Ziel der Umweltforschung im GSF-Forschungszentrum fuer Umwelt und Gesundheit ist es, das Verhalten von Umweltchemikalien in terrestrischen Oekosystemen unter moeglichst natuerlichen Bedingungen zu bestimmen. In der GSF-Lysimeteranlage Neuherberg kann das Umweltverhalten von Organika in verschiedenen Boeden untersucht werden. Zur Wiedererkennung der ausgebrachten Chemikalie bzw. zur Identifizierung aus ihr entstandener Umwandlungsprodukte und letztendlich auch zur Erstellung einer Massenbilanz fuer das ausgebrachte Praeparat wurde in der GSF die Moeglichkeit geschaffen, {sup 14}C-markierte Substanzen in Freilandlysimetern applizieren zu koennen. (orig.)

  14. Mathematical modelling of deuterium transport in field lysimeters; Mathematische Modellierung des Deuteriumtransports in Freilandlysimetern

    Energy Technology Data Exchange (ETDEWEB)

    Maloszewski, P.; Klotz, D.; Trimborn, P. [GSF - Forschungszentrum fuer Umwelt und Gesundheit GmbH, Neuherberg (Germany). Inst. fuer Hydrologie; Maciejewski, S. [Polish Academy of Sciences, Gdansk (Poland). Inst. of Hydroengineering

    1999-02-01

    The results yielded by the Variable Flow Model (VFDM) permitted determining water flow velocities and degrees of dispersiveness. It transpired that it is not possible to isolate immobile water, which is to say that the available measuring and modelling data permit no conclusion as to whether or not the system contains immobile water. Comparison with the results obtained with the Dispersion Model (DM) showed that the simpler DM model yields tracer concentration curves in the system output that are almost as good as those of the more complicated VFDM model while entailing less work. The two models yield very similar calculations of lysimeter water content. [Deutsch] Die Ergebnisse der Modellierung mit dem Variable-Flow-Modell (VFDM) ermoeglichten die Bestimmung von Wassergeschwindigkeiten des Wassers und Dispersivitaeten. Es wurde dabei festgestellt, dass eine Abtrennung des immobilen Wassers nicht moeglich ist. D.h. es kann nicht auf Grund vorhandener Messdaten und der Modellierung entschieden werden, ob das System immobiles Wasser beinhaltet oder nicht. Ein Vergleich der Ergebnisse nach dem Variable-Flow- und dem Dispersions-Modell (DM) zeigte, dass das einfache Modell DM mit weniger Aufwand fast so gute Tracerkonzentrationskurven im Output aus dem System liefert wie das komplizierte Modell mit VFDM. Die berechneten Wassergehalte der Lysimeter nach beiden Modellierungen sind sehr aehnlich. (orig.)

  15. Numerical simulation of water flow in lysimeters; Numerische Simulation des Wasserflusses in Lysimetern

    Energy Technology Data Exchange (ETDEWEB)

    Honisch, M.; Klotz, D. [GSF - Forschungszentrum fuer Umwelt und Gesundheit GmbH, Neuherberg (Germany). Inst. fuer Hydrologie

    1999-02-01

    A small-scale lysimeter plant on the premises of GSF has been dedicated to the study of water movement in sediments of Quaternary and Tertiary origin. The purpose of the present study was to describe water transport and non-reactive transport in the lysimeters under transient conditions and test the suitability of the numerical simulation programme Hydrus-2D for the unsaturated zone. The hydraulic characteristics and dispersiveness parameters were derived from earlier studies. The validity of these values was determined on the basis of a tracer experiment using the ideal tracer tritium water. [Deutsch] Zur Charakterisierung der Wasserbewegung in Sedimenten quartaeren und tertiaeren Ursprungs wird auf dem Gelaende der GSF eine Kleinlysimeteranlage betrieben. Ziel der vorliegenden Untersuchung war es, den Wasserfluss und nicht-reaktiven Transport in den Saeulen unter transienten Bedingungen zu beschreiben und hierbei die Eignung des numerischen Simulationsprogramms Hydrus-2D fuer die ungesaettigte Zone zu ueberpruefen. Die hydraulischen Kenngroessen und Dispersivitaetsparameter waren aus frueheren Untersuchungen abzuleiten. Die offene Frage hinsichtlich der Validitaet dieser Werte sollte auf der Grundlage eines Tracerexperiments mit tritiiertem Wasser als idealem Tracer ueberprueft werden. (orig.)

  16. Impact of paper mill wastewater on soil properties and crop yield through lysimeter studies.

    Science.gov (United States)

    Singh, P K; Ladwani, K; Ladwani, K; Deshbhratar, P B; Ramteke, D S

    2013-01-01

    Paper and pulp industries produce large quantities of wastewater which can have adverse effects on the receiving water systems. In the present study lysimeters were used and filled with different soils replicating natural soil horizons and provided with a leachate collection system. The physico-chemical characteristics of the soil in each lysimeter and the quality of wastewater before leaching were assessed. Treated wastewater was evaluated for crop irrigation, and was categorized according to the irrigation water class 'Increasing Problem to Severe Problem' with respect to salinity and specific ion toxicity. Sandy loam soils showed 96% chemical oxygen demand (COD) removal while clay loam soils removed 99% of COD, and the colour removal in both the cases was found to be 100%. Application of wastewater resulted in an increase of pH value, ranging from 6.2-7.6; the electrical conductivity (ECe) of saturated extracts was found to be 0.6-1.7 dS m(-1), and exchangeable sodium percentage (ESP) ranged from 7.8-11.1% in soils. Similarly, an increase in the organic carbon, available nitrogen, phosphorus and potash content of soils was observed when irrigated with wastewater. Wastewater irrigation showed increased grain and straw yield of jowar, wheat and moong. These results permit successful utilization of pulp and paper mill wastewater for crop production without damaging the soils.

  17. LYSIMETER - A UNIQUE TOOL FOR MONITORING THE INTERACTIONS AMONG THE COMPONENTS OF ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Ivan Matušek

    2016-06-01

    Full Text Available Modern lysimeter facilities in connection with meteorological stations allow monitoring and evaluation of mutual basic components of the environment, such as water, air, soil and vegetation. Water is the most important component of the ecosystem and the component which connects all the other components. Therefore, we need to know the basic distribution and water balance in the different components of the environment to be able to interpret some processes in nature. Rainfall, which is the primary source of vital processes in the soil, is formed in the air. The amount of precipitation that gets into the soil and into the groundwater is affected by weather conditions. Primary distribution of rainwater is divided between infiltration, surface runoff, transpiration and evapotranspiration. The amount of water infiltrated into the soil and then evaporated by solar activity or activities of plants can be identified primarily by monitoring changes in weight. For this monitoring we use weighable lysimeter. This equipment with the monolith size of surface area 1 m2 and the depth of 1.5 m is able to follow online updates of weight of the 2 ton body with an accuracy of 100 g. When we add to quantification of leakages through the bottom layer, we obtain a comprehensive record of rainfall at the time in the natural environment of the individual components. The obtained data can be further interpreted in terms of the needs of hydrology, agriculture, and environmental studies, and according to the purpose and objectives for which we want to use them.

  18. CO2 (dry ice) cleaning system

    Science.gov (United States)

    Barnett, Donald M.

    1995-03-01

    Tomco Equipment Company has participated in the dry ice (solid carbon dioxide, CO2) cleaning industry for over ten years as a pioneer in the manufacturer of high density, dry ice cleaning pellet production equipment. For over four years Tomco high density pelletizers have been available to the dry ice cleaning industry. Approximately one year ago Tomco introduced the DI-250, a new dry ice blast unit making Tomco a single source supplier for sublimable media, particle blast, cleaning systems. This new blast unit is an all pneumatic, single discharge hose device. It meters the insertion of 1/8 inch diameter (or smaller), high density, dry ice pellets into a high pressure, propellant gas stream. The dry ice and propellant streams are controlled and mixed from the blast cabinet. From there the mixture is transported to the nozzle where the pellets are accelerated to an appropriate blasting velocity. When directed to impact upon a target area, these dry ice pellets have sufficient energy to effectively remove most surface coatings through dry, abrasive contact. The meta-stable, dry ice pellets used for CO2 cleaning, while labeled 'high density,' are less dense than alternate, abrasive, particle blast media. In addition, after contacting the target surface, they return to their equilibrium condition: a superheated gas state. Most currently used grit blasting media are silicon dioxide based, which possess a sharp tetrahedral molecular structure. Silicon dioxide crystal structures will always produce smaller sharp-edged replicas of the original crystal upon fracture. Larger, softer dry ice pellets do not share the same sharp-edged crystalline structures as their non-sublimable counterparts when broken. In fact, upon contact with the target surface, dry ice pellets will plastically deform and break apart. As such, dry ice cleaning is less harmful to sensitive substrates, workers and the environment than chemical or abrasive cleaning systems. Dry ice cleaning system

  19. Determining CO2 storage potential during miscible CO2 enhanced oil recovery: Noble gas and stable isotope tracers

    Science.gov (United States)

    Shelton, Jenna L.; McIntosh, Jennifer C.; Hunt, Andrew; Beebe, Thomas L; Parker, Andrew D; Warwick, Peter; Drake, Ronald; McCray, John E.

    2016-01-01

    Rising atmospheric carbon dioxide (CO2) concentrations are fueling anthropogenic climate change. Geologic sequestration of anthropogenic CO2 in depleted oil reservoirs is one option for reducing CO2 emissions to the atmosphere while enhancing oil recovery. In order to evaluate the feasibility of using enhanced oil recovery (EOR) sites in the United States for permanent CO2 storage, an active multi-stage miscible CO2flooding project in the Permian Basin (North Ward Estes Field, near Wickett, Texas) was investigated. In addition, two major natural CO2 reservoirs in the southeastern Paradox Basin (McElmo Dome and Doe Canyon) were also investigated as they provide CO2 for EOR operations in the Permian Basin. Produced gas and water were collected from three different CO2 flooding phases (with different start dates) within the North Ward Estes Field to evaluate possible CO2 storage mechanisms and amounts of total CO2retention. McElmo Dome and Doe Canyon were sampled for produced gas to determine the noble gas and stable isotope signature of the original injected EOR gas and to confirm the source of this naturally-occurring CO2. As expected, the natural CO2produced from McElmo Dome and Doe Canyon is a mix of mantle and crustal sources. When comparing CO2 injection and production rates for the CO2 floods in the North Ward Estes Field, it appears that CO2 retention in the reservoir decreased over the course of the three injections, retaining 39%, 49% and 61% of the injected CO2 for the 2008, 2010, and 2013 projects, respectively, characteristic of maturing CO2 miscible flood projects. Noble gas isotopic composition of the injected and produced gas for the flood projects suggest no active fractionation, while δ13CCO2 values suggest no active CO2dissolution into formation water, or mineralization. CO2 volumes capable of dissolving in residual formation fluids were also estimated along with the potential to store pure-phase supercritical CO2. Using a combination

  20. Soil CO2 efflux of a larch forest in northern Japan

    Directory of Open Access Journals (Sweden)

    Y. Fujinuma

    2010-11-01

    Full Text Available We had continuously measured soil CO2 efflux (Rs in a larch forest in northern Japan at hourly intervals for the snow-free period in 2003 with an automated chamber system and partitioned Rs into heterotrophic respiration (Rh and autotrophic respiration (Rr by using the trench method. In addition, we applied the soil CO2 concentration gradients method to continuously measure soil CO2 profiles under snowpack in the snowy period and to partition Rs into topsoil (Oa and A horizons CO2 efflux (Ft with a depth of 0.13 m and sub-soil (C horizon CO2 efflux (Fc. We found that soil CO2 effluxes were strongly affected by the seasonal variation of soil temperature but weakly correlated with soil moisture, probably because the volumetric soil moisture (30–40% at 95% confidence interval was within a plateau region for root and microbial activities. The soil CO2 effluxes changed seasonally in parallel with soil temperature in topsoil with the peak in late summer. On the other hand, the contribution of Rr to Rs was the largest at about 50% in early summer, when canopy photosynthesis and plant growth were more active. The temperature sensitivity (Q10 of Rr peaked in June. Under snowpack, Rs was stable until mid-March and then gradually increased with snow melting. Rs summed up to 79 gC m−2 during the snowy season for 4 months. The annual Rs was determined at 934 gC m−2 y−1 in 2003, which accounted for 63% of ecosystem respiration. The annual contributions of Rh and Rs to Rs were 57% and 43%, respectively. Based on the gradient approach, Rs was partitioned vertically into litter (Oi and Oe horizons with a depth of 0.01–0.02 m, topsoil and sub-soil respirations with proportions of 6, 72 and 22%, respectively, on an annual basis. The vertical distribution of CO2 efflux was consistent with those of soil carbon and root biomass.

  1. CO2 storage capacity estimation: Methodology and gaps

    Science.gov (United States)

    Bachu, S.; Bonijoly, D.; Bradshaw, J.; Burruss, R.; Holloway, S.; Christensen, N.P.; Mathiassen, O.M.

    2007-01-01

    Implementation of CO2 capture and geological storage (CCGS) technology at the scale needed to achieve a significant and meaningful reduction in CO2 emissions requires knowledge of the available CO2 storage capacity. CO2 storage capacity assessments may be conducted at various scales-in decreasing order of size and increasing order of resolution: country, basin, regional, local and site-specific. Estimation of the CO2 storage capacity in depleted oil and gas reservoirs is straightforward and is based on recoverable reserves, reservoir properties and in situ CO2 characteristics. In the case of CO2-EOR, the CO2 storage capacity can be roughly evaluated on the basis of worldwide field experience or more accurately through numerical simulations. Determination of the theoretical CO2 storage capacity in coal beds is based on coal thickness and CO2 adsorption isotherms, and recovery and completion factors. Evaluation of the CO2 storage capacity in deep saline aquifers is very complex because four trapping mechanisms that act at different rates are involved and, at times, all mechanisms may be operating simultaneously. The level of detail and resolution required in the data make reliable and accurate estimation of CO2 storage capacity in deep saline aquifers practical only at the local and site-specific scales. This paper follows a previous one on issues and development of standards for CO2 storage capacity estimation, and provides a clear set of definitions and methodologies for the assessment of CO2 storage capacity in geological media. Notwithstanding the defined methodologies suggested for estimating CO2 storage capacity, major challenges lie ahead because of lack of data, particularly for coal beds and deep saline aquifers, lack of knowledge about the coefficients that reduce storage capacity from theoretical to effective and to practical, and lack of knowledge about the interplay between various trapping mechanisms at work in deep saline aquifers. ?? 2007 Elsevier Ltd

  2. PEAT-CO2. Assessment of CO2 emissions from drained peatlands in SE Asia

    Energy Technology Data Exchange (ETDEWEB)

    Hooijer, A.; Silvius, M.; Woesten, H.; Page, S.

    2006-12-15

    Forested tropical peatlands in SE Asia store at least 42,000 Megatonnes of soil carbon. This carbon is increasingly released to the atmosphere due to drainage and fires associated with plantation development and logging. Peatlands make up 12% of the SE Asian land area but account for 25% of current deforestation. Out of 27 million hectares of peatland, 12 million hectares (45%) are currently deforested and mostly drained. One important crop in drained peatlands is palm oil, which is increasingly used as a biofuel in Europe. In the PEAT-CO2 project, present and future emissions from drained peatlands were quantified using the latest data on peat extent and depth, present and projected land use and water management practice, decomposition rates and fire emissions. It was found that current likely CO2 emissions caused by decomposition of drained peatlands amounts to 632 Mt/y (between 355 and 874 Mt/y). This emission will increase in coming decades unless land management practices and peatland development plans are changed, and will continue well beyond the 21st century. In addition, over 1997-2006 an estimated average of 1400 Mt/y in CO2 emissions was caused by peatland fires that are also associated with drainage and degradation. The current total peatland CO2 emission of 2000 Mt/y equals almost 8% of global emissions from fossil fuel burning. These emissions have been rapidly increasing since 1985 and will further increase unless action is taken. Over 90% of this emission originates from Indonesia, which puts the country in 3rd place (after the USA and China) in the global CO2 emission ranking. It is concluded that deforested and drained peatlands in SE Asia are a globally significant source of CO2 emissions and a major obstacle to meeting the aim of stabilizing greenhouse gas emissions, as expressed by the international community. It is therefore recommended that international action is taken to help SE Asian countries, especially Indonesia, to better conserve

  3. CO 2 Capture Rate Sensitivity Versus Purchase of CO 2 Quotas. Optimizing Investment Choice for Electricity Sector

    OpenAIRE

    Coussy Paula; Raynal Ludovic

    2014-01-01

    International audience; Carbon capture technology (and associated storage), applied to power plants, reduces atmospheric CO2 emissions. This article demonstrates that, in the particular case of the deployment phase of CO2 capture technology during which CO2 quota price may be low, capturing less than 90% of total CO2 emissions from power plants can be economically attractive. Indeed, for an electric power company capture technology is interesting, only if the discounted marginal cost of captu...

  4. On the proportionality between global temperature change and cumulative CO2 emissions during periods of net negative CO2 emissions

    Science.gov (United States)

    Zickfeld, Kirsten; MacDougall, Andrew H.; Damon Matthews, H.

    2016-05-01

    Recent research has demonstrated that global mean surface air warming is approximately proportional to cumulative CO2 emissions. This proportional relationship has received considerable attention, as it allows one to calculate the cumulative CO2 emissions (‘carbon budget’) compatible with temperature targets and is a useful measure for model inter-comparison. Here we use an Earth system model to explore whether this relationship persists during periods of net negative CO2 emissions. Negative CO2 emissions are required in the majority of emissions scenarios limiting global warming to 2 °C above pre-industrial, with emissions becoming net negative in the second half of this century in several scenarios. We find that for model simulations with a symmetric 1% per year increase and decrease in atmospheric CO2, the temperature change (ΔT) versus cumulative CO2 emissions (CE) relationship is nonlinear during periods of net negative emissions, owing to the lagged response of the deep ocean to previously increasing atmospheric CO2. When corrected for this lagged response, or if the CO2 decline is applied after the system has equilibrated with the previous CO2 increase, the ΔT versus CE relationship is close to linear during periods of net negative CO2 emissions. A proportionality constant—the transient climate response to cumulative carbon emissions (TCRE)- can therefore be calculated for both positive and net negative CO2 emission periods. We find that in simulations with a symmetric 1% per year increase and decrease in atmospheric CO2 the TCRE is larger on the upward than on the downward CO2 trajectory, suggesting that positive CO2 emissions are more effective at warming than negative emissions are at subsequently cooling. We also find that the cooling effectiveness of negative CO2 emissions decreases if applied at higher atmospheric CO2 concentrations.

  5. Sulfur Isotope Analysis of Minerals and Fluids in a Natural CO2 Reservoir, Green River, Utah

    Science.gov (United States)

    Chen, F.; Kampman, N.; Bickle, M. J.; Busch, A.; Turchyn, A. V.

    2013-12-01

    different timing of gypsum vein formation. Macroscopic and microscopic gradients in the sulfur isotope composition of pyrite throughout the core and at discernible redox-reaction fronts were examined in detail to assess the role of bacteria in mediating sulfate reduction, sulfide mineralization and buffering of groundwater redox chemistry. The CO2 charged fluids and gypsum veins within the Entrada Sandstone have a narrow and very similar range in both δ34SSO4 and δ18OSO4, suggesting that the fluids (9.1-10.7‰) are the most likely source of the sulfate in the veins (11.4-12.8‰) and that the veins formed during recent fluid flow through the Entrada, with sulfate coming from remobilized gypsum beds in the Carmel. The Carmel also contains two isotopically distinct types of gypsum veins: one with δ34SSO4 values similar to the Entrada veins and one with much higher δ34SSO4 values (15.1-16.1‰). The latter are likely primary gypsum, while the former are likely secondary gypsum. Sulfur isotope fractionation between pyrite (-16.5‰ to -35.7‰) at the Carmel-Navajo interface and reservoir fluids (9.1-10.7‰) suggest that sulfur reducing bacteria play a role in producing the deposited sulfide. This data demonstrates active sulfur cycling in CO2 reservoirs with many different sulfur species cycled among various pools creating the wide isotope dispersion we observe.

  6. A Quantitative Investigation of CO2 Sequestration by Mineral Carbonation

    OpenAIRE

    Mohammad, Muneer; Ehsani, Mehrdad

    2015-01-01

    Anthropogenic activities have led to a substantial increase in carbon dioxide (CO2), a greenhouse gas (GHG), contributing to heightened concerns of global warming. In the last decade alone CO2 emissions increased by 2.0 ppm/yr. globally. In the year 2009, United States and China contributed up to 43.4% of global CO2 emissions. CO2 capture and sequestration have been recognized as promising solutions to mitigate CO2 emissions from fossil fuel based power plants. Typical techniques for carbon c...

  7. El CO2 como disolvente y como reactivo

    OpenAIRE

    La Franca Pitarresi, Vincenzo Rosario

    2016-01-01

    Existen numerosas ventajas asociada con el uso de CO2 , tanto como disolvente que como reactivo, y todas se pueden resumir en cuatro categorías generales: beneficios ambiental, beneficios de salud y seguridad, beneficios en el procedimiento y beneficios químicos. Los procesos que implican el CO2 como disolvente no aumentaría las emisiones de CO2, más bien proporcionaría una oportunidad para el reciclaje de CO2 residual. Además, los esfuerzos para secuestrar el CO2 producido de los gases de co...

  8. Storage of CO2 at low temperature as liquid or solid gas hydrate - Application to the Biscay deep zone in the French EEZ

    Science.gov (United States)

    Burnol, André; Thinon, Isabelle; Audigane, Pascal; Leynet, Aurélien

    2013-04-01

    Amongst the various CO2 geological storage options currently under consideration, the deep saline aquifers (beyond 800-m depth) were considered to present the most interesting storage capacity due to the density of CO2 in its supercritical state. However, at lower temperature, another form of storage is possible, either in the state of CO2 hydrates or liquid CO2 (1, 2). In Alaska, a first demonstrator showed recently the possibility of exchange of CO2 and CH4 in natural gas hydrates. At higher pressures common in deep-sea sediments, liquid CO2 can be denser than the overlying seawater and therefore be trapped in the marine sediments (2). We explored in this work the storage capacity at the Biscay deep zone in the French Exclusive Economic Zone (EEZ). A local bathymetry of the zone (abyssal plain and continental margin) was used to define a potential interesting zone for the CO2 storage, considering different safety criteria. A sensitivity analysis on the geothermal gradient was carried out using two extreme scenarios (Low and High gradient) based on the available Ocean Drilling Program's data. In both cases, the Negative Buoyancy Zone (NBZ) and the CO2 Hydrate Formation Zone (HFZ) were calculated using the GERG-2008 Equation of State for liquid CO2 and the CSMGem code for CO2 hydrate, respectively. Following this sensitivity analysis, a CO2 injection depth is proposed and the French "deep offshore" storage capacity is quantitatively evaluated and compared to the "onshore" storage capacity in deep saline aquifers. References 1. Le Nindre Y., Allier D., Duchkov A., Altunina L. K., Shvartsev S., Zhelezniak M. and Klerkx J. (2011) Storing CO2 underneath the Siberian Permafrost: A win-win solution for long-term trapping of CO2 and heavy oil upgrading. Energy Procedia4, 5414-5421 2. House K. Z., Schrag D. P., Harvey C. F. and Lackner K. S. (2006) Permanent carbon dioxide storage in deep-sea sediments. PNAS

  9. CO2 Budget and Rectification Airborne Study

    Science.gov (United States)

    Grainger, C. A.

    2004-01-01

    The main purpose of this award was to supply a platform for the airborne measurements of gases associated with the CO2 Budget and Regional Airborne Study (COBRA). The original program was to consist of three field programs: the first was to be in 1999, the second in 2000, and the third in 2001. At the end of the second field program, it was agreed that the science could better be served by making the measurements in northern Brazil, rather than in North America. The final North American program would be postponed until after two field programs in Brazil. A substantial amount of effort was diverted into making plans and preparations for the Brazil field programs. The Brazil field programs were originally scheduled to take place in the Fall of 2002 and Spring of 2003. Carrying out the field program in Brazil was going to logistically much more involved than a program in the US. Shipping of equipment, customs, and site preparations required work to begin many months prior to the actual measurement program. Permission to fly in that country was also not trivial and indeed proved to be a major obstacle. When we were not able to get permission to fly in Brazil for the 2002 portion of the experiment, the program was pushed back to 2003. When permission by the Brazilian government was not given in time for a Spring of 2003 field program, the experiment was postponed again to begin in the Fall of 2003.

  10. A centrifuge CO2 pellet cleaning system

    Science.gov (United States)

    Foster, C. A.; Fisher, P. W.; Nelson, W. D.; Schechter, D. E.

    1995-03-01

    An advanced turbine/CO2 pellet accelerator is being evaluated as a depaint technology at Oak Ridge National Laboratory (ORNL). The program, sponsored by Warner Robins Air Logistics Center (ALC), Robins Air Force Base, Georgia, has developed a robot-compatible apparatus that efficiently accelerates pellets of dry ice with a high-speed rotating wheel. In comparison to the more conventional compressed air 'sandblast' pellet accelerators, the turbine system can achieve higher pellet speeds, has precise speed control, and is more than ten times as efficient. A preliminary study of the apparatus as a depaint technology has been undertaken. Depaint rates of military epoxy/urethane paint systems on 2024 and 7075 aluminum panels as a function of pellet speed and throughput have been measured. In addition, methods of enhancing the strip rate by combining infra-red heat lamps with pellet blasting and by combining the use of environmentally benign solvents with the pellet blasting have also been studied. The design and operation of the apparatus will be discussed along with data obtained from the depaint studies.

  11. The effects of CO2-differentiated vehicle tax systems on car choice, CO2 emissions and tax revenues

    NARCIS (Netherlands)

    Kok, R.

    2011-01-01

    This paper assesses the impacts of a CO2-differentiated tax policy designed to influence car purchasing trends towards lower CO2 emitting vehicles in the Netherlands. Since 2009, gasoline and diesel cars up to 110 and 95 gram CO2 per km are exempted from the vehicle registration tax (VRT). In

  12. The effects of CO2-differentiated vehicle tax systems on car choice, CO2 emissions and tax revenues

    NARCIS (Netherlands)

    Kok, R.

    2011-01-01

    This paper assesses the impacts of a CO2-differentiated tax policy designed to influence car purchasing trends towards lower CO2 emitting vehicles in the Netherlands. Since 2009, gasoline and diesel cars up to 110 and 95 gram CO2 per km are exempted from the vehicle registration tax (VRT). In additi

  13. Effects of Atmospheric CO2 Enrichment on Soil CO2 Efflux in a Young Longleaf Pine System

    Directory of Open Access Journals (Sweden)

    G. Brett Runion

    2012-01-01

    Full Text Available The southeastern landscape is composed of agricultural and forest systems that can store carbon (C in standing biomass and soil. Research is needed to quantify the effects of elevated atmospheric carbon dioxide (CO2 on terrestrial C dynamics including CO2 release back to the atmosphere and soil sequestration. Longleaf pine savannahs are an ecologically and economically important, yet understudied, component of the southeastern landscape. We investigated the effects of ambient and elevated CO2 on soil CO2 efflux in a young longleaf pine system using a continuous monitoring system. A significant increase (26.5% in soil CO2 efflux across 90 days was observed under elevated CO2; this occurred for all weekly and daily averages except for two days when soil temperature was the lowest. Soil CO2 efflux was positively correlated with soil temperature with a trend towards increased efflux response to temperature under elevated CO2. Efflux was negatively correlated with soil moisture and was best represented using a quadratic relationship. Soil CO2 efflux was not correlated with root biomass. Our data indicate that, while elevated CO2 will increase feedback of CO2 to the atmosphere via soil efflux, terrestrial ecosystems will remain potential sinks for atmospheric CO2 due to greater biomass production and increased soil C sequestration.

  14. CO2GeoNet, the unique role of the European scientific body on CO2 geological storage

    NARCIS (Netherlands)

    Czernichowski-Lauriol, I.; Arts, R.; Durand, D.; Durucan, S.; Johannessen, P.; May, F.; Olivier, M.-L.; Persoglia, S.; Riley, N.; Sohrabi, M.; Stokka, S.; Vercelli, S.; Vizika-Kavvadias, O.

    2009-01-01

    CO2GeoNet is a Network of Excellence on the geological storage of CO2, initiated by the EC's 6th research framework programme in 2004 and integrating Europe's key research institutes to create a scientific reference body dedicated to the development of CO2 geological storage as a viable option for m

  15. Oxidative degradation of dyes in water using Co2+/H2O2 and Co2+/peroxymonosulfate.

    Science.gov (United States)

    Ling, Sie King; Wang, Shaobin; Peng, Yuelian

    2010-06-15

    Dye degradation using advanced oxidation processes with Co(2+)/H(2)O(2) and Co(2+)/peroxymonosulfate (PMS) systems has been investigated. Two types of dyes, basic blue 9 and acid red 183, were employed. Several parameters affecting dye degradation such as Co(2+), PMS, H(2)O(2), and dye concentrations were investigated. The optimal ratio of oxidant (PMS, H(2)O(2))/Co(2+) for the degradation of two dyes was determined. It is found that dye decomposition is much faster in Co(2+)/PMS system than in Co(2+)/H(2)O(2). For Co(2+)/H(2)O(2), an optimal ratio of H(2)O(2) to Co(2