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Sample records for carbon dioxide air

  1. Carbon Dioxide Extraction from Air: Is It An Option?

    SciTech Connect

    Klaus Lackner; Hans-Joachim Ziock; Patrick Grimes

    1999-02-01

    Controlling the level of carbon dioxide in the atmosphere without limiting access to fossil energy resources is only possible if carbon dioxide is collected and disposed of away from the atmosphere. While it may be cost-advantageous to collect the carbon dioxide at concentrated sources without ever letting it enter the atmosphere, this approach is not available for the many diffuse sources of carbon dioxide. Similarly, for many older plants a retrofit to collect the carbon dioxide is either impossible or prohibitively expensive. For these cases we investigate the possibility of collecting the carbon dioxide directly from the atmosphere. We conclude that there are no fundamental obstacles to this approach and that it deserves further investigation. Carbon dioxide extraction directly from atmosphere would allow carbon management without the need for a completely changed infrastructure. In addition it eliminates the need for a complex carbon dioxide transportation infrastructure, thus at least in part offsetting the higher cost of the extraction from air.

  2. Carbon Dioxide Detection and Indoor Air Quality Control.

    PubMed

    Bonino, Steve

    2016-04-01

    When building ventilation is reduced, energy is saved because it is not necessary to heat or cool as much outside air. Reduced ventilation can result in higher levels of carbon dioxide, which may cause building occupants to experience symptoms. Heating or cooling for ventilation air can be enhanced by a DCV system, which can save energy while providing a comfortable environment. Carbon dioxide concentrations within a building are often used to indicate whether adequate fresh air is being supplied to the building. These DCV systems use carbon dioxide sensors in each space or in the return air and adjust the ventilation based on carbon dioxide concentration; the higher the concentration, the more people occupy the space relative to the ventilation rate. With a carbon dioxide sensor DCV system, the fresh air ventilation rate varies based on the number ofpeople in the space, saving energy while maintaining a safe and comfortable environment. PMID:27183813

  3. Carbon dioxide extraction from air: Is it an option?

    SciTech Connect

    Lackner, K.S.; Grimes, P.; Ziock, H.J.

    1999-07-01

    Controlling the level of carbon dioxide in the atmosphere without limiting access to fossil energy resources is only possible if carbon dioxide is collected and disposed of away from the atmosphere. While it may be cost-advantageous to collect the carbon dioxide at concentrated sources without ever letting it enter the atmosphere, this approach is not available for the many diffuse sources of carbon dioxide. Similarly, for many older plants, a retrofit to collect the carbon dioxide is either impossible or prohibitively expensive. For these cases the authors investigate the possibility of collecting the carbon dioxide directly from the atmosphere. The authors conclude that there are no fundamental obstacles to this approach and that it deserves further investigation. Carbon dioxide extraction directly from the atmosphere would allow carbon management without the need for a completely changed infrastructure. In addition it eliminates the need for a completely changed infrastructure. In addition it eliminates the need for a complex carbon dioxide transportation infrastructure, thus at least in part offsetting the higher cost of extraction from air.

  4. Carbon dioxide emissions from international air freight

    NASA Astrophysics Data System (ADS)

    Howitt, Oliver J. A.; Carruthers, Michael A.; Smith, Inga J.; Rodger, Craig J.

    2011-12-01

    Greenhouse gas emissions from international air transport were excluded from reduction targets under the Kyoto Protocol, partly because of difficulties with quantifying and apportioning such emissions. Although there has been a great deal of recent research into calculating emissions from aeroplane operations globally, publicly available emissions factors for air freight emissions are scarce. This paper presents a methodology to calculate the amount of fuel burnt and the resulting CO 2 emissions from New Zealand's internationally air freighted imports and exports in 2007. This methodology could be applied to other nations and/or regions. Using data on fuel uplift, air freight and air craft movements, and assumptions on mean passenger loadings and the mass of passengers and air freight, CO 2 emissions factors of 0.82 kg CO 2 per t-km and 0.69 kg CO 2 per t-km for short-haul and long-haul journeys, respectively, were calculated. The total amount of fuel consumed for the international air transport of New Zealand's imports and exports was calculated to be 0.21 Mt and 0.17 Mt respectively, with corresponding CO 2 emissions of 0.67 Mt and 0.53 Mt.

  5. Carbon dioxide, ground air and carbon cycling in Gibraltar karst

    NASA Astrophysics Data System (ADS)

    Mattey, D. P.; Atkinson, T. C.; Barker, J. A.; Fisher, R.; Latin, J.-P.; Durrell, R.; Ainsworth, M.

    2016-07-01

    We put forward a general conceptual model of CO2 behaviour in the vadose zone of karst aquifers, based on physical principles of air flow through porous media and caves, combined with a geochemical interpretation of cave monitoring data. This 'Gibraltar model' links fluxes of water, air and carbon through the soil with the porosity of the vadose zone, the circulation of ground air and the ventilation of caves. Gibraltar hosts many natural caves whose locations span the full length and vertical range of the Rock. We report results of an 8-year monitoring study of carbon in soil organic matter and bedrock carbonate, dissolved inorganic carbon in vadose waters, and gaseous CO2 in soil, cave and ground air. Results show that the regime of cave air CO2 results from the interaction of cave ventilation with a reservoir of CO2-enriched ground air held within the smaller voids of the bedrock. The pCO2 of ground air, and of vadose waters that have been in close contact with it, are determined by multiple factors that include recharge patterns, vegetation productivity and root respiration, and conversion of organic matter to CO2 within the soil, the epikarst and the whole vadose zone. Mathematical modelling and field observations show that ground air is subject to a density-driven circulation that reverses seasonally, as the difference between surface and underground temperatures reverses in sign. The Gibraltar model suggests that cave air pCO2 is not directly related to CO2 generated in the soil or the epikarstic zone, as is often assumed. Ground air CO2 formed by the decay of organic matter (OM) washed down into the deeper unsaturated zone is an important additional source of pCO2. In Gibraltar the addition of OM-derived CO2 is the dominant control on the pCO2 of ground air and the Ca-hardness of waters within the deep vadose zone. The seasonal regime of CO2 in cave air depends on the position of a cave in relation to the density-driven ground air circulation pattern which

  6. Equipment for Measuring Air Flow, Air Temperature, Relative Humidity, and Carbon Dioxide in Schools. Technical Bulletin.

    ERIC Educational Resources Information Center

    Jacobs, Bruce W.

    Information on equipment and techniques that school facility personnel may use to evaluate IAQ conditions are discussed. Focus is placed on the IAQ parameters of air flow, air temperature, relative humidity, as well as carbon dioxide and the equipment used to measure these factors. Reasons for measurement and for when the measurement of these…

  7. Carbon dioxide concentrator

    NASA Technical Reports Server (NTRS)

    Williams, C. F.; Huebscher, R. G.

    1972-01-01

    Passed exhaled air through electrochemical cell containing alkali metal carbonate aqueous solution, and utilizes platinized electrodes causing reaction of oxygen at cathode with water in electrolyte, producing hydroxyl ions which react with carbon dioxide to form carbonate ions.

  8. Indoor Air Quality in Schools (IAQ): The Importance of Monitoring Carbon Dioxide Levels.

    ERIC Educational Resources Information Center

    Sundersingh, David; Bearg, David W.

    This article highlights indoor air quality and exposure to pollutants at school. Typical air pollutants within schools include environmental tobacco smoke, formaldehyde, volatile organic compounds, nitrogen oxides, carbon monoxide, carbon dioxide, allergens, pathogens, radon, pesticides, lead, and dust. Inadequate ventilation, inefficient…

  9. Objective Volumetric Comparison of Room Air versus Carbon Dioxide for Colonic Distention at Screening CT Colonography

    PubMed Central

    Patrick, James L.; Bakke, Joshua R.; Bannas, Peter; Kim, David H.; Lubner, Meghan G.; Pickhardt, Perry J.

    2014-01-01

    Purpose To objectively compare colonic distention at CT colonography (CTC) achieved with manual room air versus automated low-pressure carbon dioxide using a novel automated volumetric quality assessment tool. Methods Volumetric analysis was retrospectively performed on CTC studies in 300 asymptomatic adults using an automated quality assessment tool (V3D Colon [beta version], Viatronix). Colonic distention was achieved with room air self-administered to tolerance via hand-held pump (mean number of pumps, 39 ± 32) in 150 individuals (mean age, 59 years; 98 men, 51 women) and via continuous low-pressure automated infusion of carbon dioxide in 150 individuals (mean age, 57 years; 89 men, 61 women). CTC studies in supine and prone position were assessed to determine total colonic volume (luminal gas and fluid). The colonic length along the automated centerline was also recorded to enable calculation of length-adjusted colonic volumes. Results The mean total colonic volume (± SD) for individuals receiving room air and carbon dioxide distention was 1809± 514 mL and 2223 ± 686 mL, respectively (p<0.01). The prone position was better distended in 78.7% (118/150) of cases using room air; whereas, the supine was better in 66.0% (99/150) of carbon dioxide cases (p<0.01). Using a volume threshold of 2000 ml, 49 (32.7%) of room air cases and 92 (61.3%) of CO2 cases were above this cut-off. The mean length-adjusted colonic volume (mL/cm) for the room air and carbon dioxide techniques was 9.9 ± 2.4 mL/cm and 11.6 ± 2.6 mL/cm (p<0.01). Conclusions Using automated volumetry allowed quantitative analyses of colonic volumes and objectively confirmed that continuous low-pressure carbon dioxide provides greater overall colonic distention than the manual room air technique at CTC. The supine position demonstrated better distention with carbon dioxide, whereas the prone position was better distended with the room air technique. PMID:25081924

  10. Response of sugarcane sucrose yields to carbon dioxide enrichment and elevated air temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four sugarcane cultivars (CP 72-2086, CP 73-1547, CP 88-1508, and CP 80-1827) were grown in elongated temperature-gradient greenhouses (TGG) at ambient or elevated carbon dioxide (CO2) of 360 or 720 µmol CO2 mol-1 air (ppm, mole fraction basis), respectively. Elevated CO2 was maintained by injection...

  11. Estuary Turbulence and Air-Water Carbon Dioxide Exchange

    NASA Astrophysics Data System (ADS)

    Orton, Philip Mark

    The mixing of constituents between estuarine bottom and surface waters or between estuarine surface waters and the atmosphere are two topics of growing interest, in part due to the potentially important role of estuaries in global carbon budgets. These two types of mixing are typically driven by turbulence, and a research project was developed to improve the scientific understanding of atmospheric and tidal controls on estuary turbulence and airwater exchange processes. Highlights of method development and field research on the Hudson River estuary include several deployments of bottom mounted current profilers to quantify the turbulent kinetic energy (TKE) budget, and construction and deployment of an instrumented catamaran that makes autonomous measurements of air-water CO2 exchange (FCO2), water TKE dissipation at 50 cm depth (epsilon50), and other physical properties just above and below the air-water interface. On the Hudson, wind correlates strongly with epsilon50, but surface water speed and airwater heat flux also have moderate correlations with epsilon50. In partially mixed estuaries such as the Hudson, as well as salt wedge estuaries, baroclinic pressure forcing typically causes spring ebb tides to have much stronger upper water column shear than flood tides. The Hudson data are used to show that this shear leads to local shear instability and stronger near-surface turbulence on spring ebbs. Also, buoyancy budget terms are compared to demonstrate how water-to-air heat fluxes can influence stratification and indirectly influence epsilon50. Looking more closely at the role of wind forcing, it is demonstrated that inland propagation of the sea breeze on warm sunny days leads to arrival in phase with peak solar forcing at seaward stations, but several hours later at up-estuary stations. Passage of the sea breeze front raises the air-water CO2 flux by 1-2 orders of magnitude, and drives epsilon50 comparable to spring tide levels in the upper meter of the water

  12. Made-to-order metal-organic frameworks for trace carbon dioxide removal and air capture

    PubMed Central

    Shekhah, Osama; Belmabkhout, Youssef; Chen, Zhijie; Guillerm, Vincent; Cairns, Amy; Adil, Karim; Eddaoudi, Mohamed

    2014-01-01

    Direct air capture is regarded as a plausible alternate approach that, if economically practical, can mitigate the increasing carbon dioxide emissions associated with two of the main carbon polluting sources, namely stationary power plants and transportation. Here we show that metal-organic framework crystal chemistry permits the construction of an isostructural metal-organic framework (SIFSIX-3-Cu) based on pyrazine/copper(II) two-dimensional periodic 44 square grids pillared by silicon hexafluoride anions and thus allows further contraction of the pore system to 3.5 versus 3.84 Å for the parent zinc(II) derivative. This enhances the adsorption energetics and subsequently displays carbon dioxide uptake and selectivity at very low partial pressures relevant to air capture and trace carbon dioxide removal. The resultant SIFSIX-3-Cu exhibits uniformly distributed adsorption energetics and offers enhanced carbon dioxide physical adsorption properties, uptake and selectivity in highly diluted gas streams, a performance, to the best of our knowledge, unachievable with other classes of porous materials. PMID:24964404

  13. Made-to-order metal-organic frameworks for trace carbon dioxide removal and air capture

    NASA Astrophysics Data System (ADS)

    Shekhah, Osama; Belmabkhout, Youssef; Chen, Zhijie; Guillerm, Vincent; Cairns, Amy; Adil, Karim; Eddaoudi, Mohamed

    2014-06-01

    Direct air capture is regarded as a plausible alternate approach that, if economically practical, can mitigate the increasing carbon dioxide emissions associated with two of the main carbon polluting sources, namely stationary power plants and transportation. Here we show that metal-organic framework crystal chemistry permits the construction of an isostructural metal-organic framework (SIFSIX-3-Cu) based on pyrazine/copper(II) two-dimensional periodic 44 square grids pillared by silicon hexafluoride anions and thus allows further contraction of the pore system to 3.5 versus 3.84 Å for the parent zinc(II) derivative. This enhances the adsorption energetics and subsequently displays carbon dioxide uptake and selectivity at very low partial pressures relevant to air capture and trace carbon dioxide removal. The resultant SIFSIX-3-Cu exhibits uniformly distributed adsorption energetics and offers enhanced carbon dioxide physical adsorption properties, uptake and selectivity in highly diluted gas streams, a performance, to the best of our knowledge, unachievable with other classes of porous materials.

  14. Carbon dioxide partial pressure and carbon fluxes of air-water interface in Taihu Lake, China

    NASA Astrophysics Data System (ADS)

    Fan, Chengxin; Hu, Weiping; Ford, Phillip W.; Chen, Yuwei; Qu, Wenchuan; Zhang, Lu

    2005-03-01

    To obtain carbon dioxide (CO2) flux between water-air interface of Taihu lake, monthly water samplers at 14 sites and the local meteorological data of the lake were collected and analyzed in 1998. Carbon dioxide partial pressures (pCO2) at air-water interface in the lake were calculated using alkalinity, pH, ionic strength, active coefficient, and water temperature. The carbon fluxes at different sublakes and areas were estimated by concentration gradient between water and air in consideration of Schmidt numbers of 600 and daily mean windspeed at 10 m above water surface. The results indicated that the mean values of pCO2 in Wuli Lake, Meiliang Bay, hydrophyte area, west littoral zone, riverine mouths, and the open lake areas were 1 807.8±1 071.4 (mean±standard deviation) μatm (1atm=1.013 25×105Pa), 416.3±217.0 μatm, 576.5±758.8 μatm, 304.2±243.5 μatm, 1 933.6±1 144.7 μatm, and 448.5±202.6 μatm, respectively. Maximum and minimum pCO2 values were found in the hypertrophic (4 053.7 μatm) and the eutrophic (3.2 μatm) areas. The riverine mouth areas have the maximum fluxes (82.0±62.8 mmol/m2a). But there was no significant difference between eutrophic and mesotrophic areas in pCO2 and the flux of CO2. The hydrophyte area, however, has the minimum (-0.58±12.9 mmol/m2a). In respect to CO2 equilibrium, input of the rivers will obviously influence inorganic carbon distribution in the riverine estuary. For example, the annual mean CO2 flux in Zhihugang River estuary was 19 times of that in Meiliang Bay, although the former is only a part of the latter. The sites in the body of the lake show a clear seasonal cycle with pCO2 higher than atmospheric equilibrium in winter, and much lower than atmospheric in summer due to CO2 consumption by photosynthesis. The CO2 amount of the net annual evasion that enters the atmosphere is 28.42×104 t/a, of which those from the west littoral zone and the open lake account for 53.8% and 36.7%, respectively.

  15. Carbon dioxide dangers demonstration model

    USGS Publications Warehouse

    Venezky, Dina; Wessells, Stephen

    2010-01-01

    Carbon dioxide is a dangerous volcanic gas. When carbon dioxide seeps from the ground, it normally mixes with the air and dissipates rapidly. However, because carbon dioxide gas is heavier than air, it can collect in snowbanks, depressions, and poorly ventilated enclosures posing a potential danger to people and other living things. In this experiment we show how carbon dioxide gas displaces oxygen as it collects in low-lying areas. When carbon dioxide, created by mixing vinegar and baking soda, is added to a bowl with candles of different heights, the flames are extinguished as if by magic.

  16. Distribution and air-sea fluxes of carbon dioxide on the Chukchi Sea shelf

    NASA Astrophysics Data System (ADS)

    Pipko, I. I.; Pugach, S. P.; Repina, I. A.; Dudarev, O. V.; Charkin, A. N.; Semiletov, I. P.

    2015-12-01

    This article presents the results of long-term studies of the dynamics of carbonate parameters and air-sea carbon dioxide fluxes on the Chukchi Sea shelf during the summer. As a result of the interaction of physical and biological factors, the surface waters on the west of Chukchi Sea were undersaturated with carbon dioxide when compared with atmospheric air; the partial pressure of CO2 varied in the range from 134 to 359 μatm. The average value of CO2 flux in the Chukchi Sea per unit area varied in the range from-2.4 to-22.0 mmol /(m2 day), which is significantly higher than the average value of CO2 flux in the World Ocean. It has been estimated that the minimal mass of C absorbed by the surface of Chukchi Sea from the atmosphere during ice-free season is 13 × 1012 g; a great part of this carbon is transported to the deeper layers of sea and isolated from the atmosphere for a long period of time. The studies of the carbonate system of the Chukchi Sea, especially of its western part, will provide some new data on the fluxes of carbon dioxide in the Arctic Ocean and their changes. Our analysis can be used for an interpretation of the satellite assessment of CO2 fluxes and dissolved CO2 distribution in the upper layers of the ocean.

  17. Limitations to soybean photosynthesis at elevated carbon dioxide in free-air enrichment and open top chamber systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It has been suggested that the stimulation of soybean photosynthesis by elevated carbon dioxide concentration was less in free-air carbon dioxide enrichment (FACE) systems than in open top chambers (OTC). However, this has not been tested using the same cultivars grown in the same location. We tes...

  18. High-Performance Sorbents for Carbon Dioxide Capture from Air

    SciTech Connect

    Sholl, David; Jones, Christopher

    2013-03-13

    This project has focused on capture of CO{sub 2} from ambient air (“air capture”). If this process is technically and economically feasible, it could potentially contribute to net reduction of CO{sub 2} emissions in ways that are complementary to better developed techniques for CO{sub 2} from concentrated point sources. We focused on cyclic adsorption processes for CO{sub 2} capture from air in which the entire cycle is performed at moderate temperatures. The project involved both experimental studies of sorbent materials and process level modeling of cyclic air capture processes. In our experimental work, a series of amine-functionalized silica adsorbents were prepared and characterized to determine the impact of molecular architecture on CO{sub 2} capture. Some key findings were: • Amine functionalized silicas can be prepared with high enough CO{sub 2} capacities under ambient conditions to merit consideration for use in air capture processes. • Primary amines are better candidates for CO{sub 2} capture than secondary or tertiary amines, both in terms of amine efficiency for CO{sub 2} adsorption and enhanced water affinity. • Mechanistic understanding of degradation of these materials can enable control of molecular architecture to significantly improve material stability. Our process modeling work provided the first publically available cost and energy estimates for cyclic adsorption processes for air capture of CO{sub 2}. Some key findings were: • Cycles based on diurnal ambient heating and cooling cannot yield useful purities or amounts of captured CO{sub 2}. • Cycles based on steam desorption at 110 oC can yield CO{sub 2} purities of ~88%. • The energy requirements for cycles using steam desorption are dominated by needs for thermal input, which results in lower costs than energy input in the form of electricity. Cyclic processes with operational costs of less than $100 tCO{sub 2}-net were described, and these results point to process and

  19. Air-sea exchange of carbon dioxide in the Southern Ocean and Antarctic marginal ice zone

    NASA Astrophysics Data System (ADS)

    Butterworth, Brian J.; Miller, Scott D.

    2016-07-01

    Direct carbon dioxide flux measurements using eddy covariance from an icebreaker in the high-latitude Southern Ocean and Antarctic marginal ice zone are reported. Fluxes were combined with the measured water-air carbon dioxide partial pressure difference (ΔpCO2) to compute the air-sea gas transfer velocity (k, normalized to Schmidt number 660). The open water data showed a quadratic relationship between k (cm h-1) and the neutral 10 m wind speed (U10n, m s-1), kopen = 0.245 U10n2 + 1.3, in close agreement with decades old tracer-based results and much lower than cubic relationships inferred from previous open ocean eddy covariance studies. In the marginal ice zone, the effective gas transfer velocity decreased in proportion to sea ice cover, in contrast with predictions of enhanced gas exchange in the presence of sea ice. The combined open water and marginal ice zone results affect the calculated magnitude and spatial distribution of Southern Ocean carbon flux.

  20. NMR study comparing capillary trapping in Berea sandstone of air, carbon dioxide, and supercritical carbon dioxide after imbibition of water

    NASA Astrophysics Data System (ADS)

    Prather, Cody A.; Bray, Joshua M.; Seymour, Joseph D.; Codd, Sarah L.

    2016-02-01

    Nuclear magnetic resonance (NMR) techniques were used to study the capillary trapping mechanisms relevant to carbon sequestration. Capillary trapping is an important mechanism in the initial trapping of supercritical CO2 in the pore structures of deep underground rock formations during the sequestration process. Capillary trapping is considered the most promising trapping option for carbon sequestration. NMR techniques noninvasively monitor the drainage and imbibition of air, CO2, and supercritical CO2 with DI H2O at low capillary numbers in a Berea sandstone rock core under conditions representative of a deep underground saline aquifer. Supercritical CO2 was found to have a lower residual nonwetting (NW) phase saturation than that of air and CO2. Supercritical CO2 behaves differently than gas phase air or CO2 and leads to a reduction in capillary trapping. NMR relaxometry data suggest that the NW phase, i.e., air, CO2, or supercritical CO2, is preferentially trapped in larger pores. This is consistent with snap-off conditions being more favorable in macroscale pores, as NW fluids minimize their contact area with the solid and hence prefer larger pores.

  1. Moisture-swing sorption for carbon dioxide capture from ambient air: a thermodynamic analysis.

    PubMed

    Wang, Tao; Lackner, Klaus S; Wright, Allen B

    2013-01-14

    An ideal chemical sorbent for carbon dioxide capture from ambient air (air capture) must have a number of favourable properties, such as environmentally benign behaviour, a high affinity for CO(2) at very low concentration (400 ppm), and a low energy cost for regeneration. The last two properties seem contradictory, especially for sorbents employing thermal swing adsorption. On the other hand, thermodynamic analysis shows that the energy cost of an air capture device need only be slightly larger than that of a flue gas scrubber. The moisture swing separation process studied in this paper provides a novel approach to low cost CO(2) capture from air. The anionic exchange resin sorbent binds CO(2) when dry and releases it when wet. A thermodynamic model with coupled phase and chemical equilibria is developed to study the complex H(2)O-CO(2)-resin system. The moisture swing behaviour is compatible with hydration energies changing with the activity of water on the resin surfaces. This activity is in turn set by the humidity. The rearrangement of hydration water on the resin upon the sorption of a CO(2) molecule is predicted as a function of the humidity and temperature. Using water as fuel to drive the moisture swing enables an economical, large-scale implementation of air capture. By generating CO(2) with low partial pressures, the present technology has implications for in situ CO(2) utilizations which require low pressure CO(2) gas rather than liquid CO(2). PMID:23172123

  2. Development of an Eddy Covariance System for Air-Sea Carbon Dioxide Exchange

    NASA Astrophysics Data System (ADS)

    Miller, S. D.; Marandino, C. A.; McCormick, C.; Saltzman, E. S.

    2006-12-01

    We are developing a ship-based system to measure the air-sea pCO2 gradient and air-sea turbulent flux of CO2 over the ocean. The eddy covariance flux system uses off-the-shelf instruments to measure the turbulent wind vector (Campbell Scientific CSAT3 sonic anemometer), platform motion (Systron Donner Motion Pak II), and carbon dioxide molar density (LiCor 7000 Infrared Gas Analyzer). Two major sources of uncertainty in calculated fluxes are the effect of water vapor fluctuations on air density fluctuations (the WPL effect, Webb, Pearman and Leuning. 1980), and a spurious CO2 signal due to the sensitivity of the gas analyzer to platform motion (McGillis et al., 1998). Two flux systems were deployed side-by-side on a cruise from Manzanillo, Mexico to Puntas Arenas, Chile, in January 2006. Results from the cruise are presented, with a focus on our attempts to reduce biases in the calculated air-sea CO2 flux due to the WPL effect and the motion sensitivity of the gas analyzer.

  3. Response of electrochemical oxygen sensors to inert gas-air and carbon dioxide-air mixtures: measurements and mathematical modelling.

    PubMed

    Walsh, P T; Gant, S E; Dowker, K P; Batt, R

    2011-02-15

    Electrochemical oxygen gas sensors are widely used for monitoring the state of inertisation of flammable atmospheres and to warn of asphyxiation risks. It is well established but not widely known by users of such oxygen sensors that the response of the sensor is affected by the nature of the diluent gas responsible for the decrease in ambient oxygen concentration. The present work investigates the response of electrochemical sensors, with either acid or alkaline electrolytes, to gas mixtures comprising air with enhanced levels of nitrogen, carbon dioxide, argon or helium. The measurements indicate that both types of sensors over-read the oxygen concentrations when atmospheres contain high levels of helium. Sensors with alkaline electrolytes are also shown to underestimate the severity of the hazard in atmospheres containing high levels of carbon dioxide. This deviation is greater for alkaline electrolyte sensors compared to acid electrolyte sensors. A Computational Fluid Dynamics (CFD) model is developed to predict the response of an alkaline electrolyte, electrochemical gas sensor. Differences between predicted and measured sensor responses are less than 10% in relative terms for nearly all of the gas mixtures tested, and in many cases less than 5%. Extending the model to simulate responses of sensors with acid electrolytes would be straightforward. PMID:21112151

  4. Mechanism Study of Carbon Dioxide Capture from Ambient Air by Hydration Energy Variation

    NASA Astrophysics Data System (ADS)

    Shi, X.; Lackner, K. S.

    2014-12-01

    Hydration of neutral and ionic species on solid interfaces plays an important role in a wide range of natural and engineered processes within energy systems as well as biological and environmental systems. Various chemical reactions are significantly enhanced, both in the rate and the extent of the reaction, because of water molecules present or absent at the interface. A novel technology for carbon dioxide capture, driven by the free energy difference between more or less hydrated states of an anionic exchange resin is studied for a new approach to absorb CO2 from ambient air. For these materials the affinity to CO2 is dramatically lowered as the availability of water is increased. This makes it possible to absorb CO2 from air in a dry environment and release it at two orders of magnitude larger partial pressures in a wet environment. While the absorption process and the thermodynamic properties of air capture via ion exchange resins have been demonstrated, the underlying physical mechanisms remain to be understood. In order to rationally design better sorbent materials, the present work elucidates through molecular dynamics and quantum mechanical modeling the energy changes in the carbonate, bicarbonate and hydroxide ions that are induced by hydration, and how these changes affect sorbent properties. A methodology is developed to determine the free energy change during carbonate ion hydrolysis changes with different numbers of water molecules present. This makes it possible to calculate the equilibrium in the reaction CO3--•nH2O ↔ HCO3- • m1H2O + OH- • m2H2O + (n - 1 - m1 - m2)H2O Molecular dynamics models are used to calculate free energies of hydration for the CO32- ion, the HCO3- ion, and the OH- ion as function of the amount of water that is present. A quantum mechanical model is employed to study the equilibrium of the reaction Na2CO3 + H2O ↔ NaHCO3 + NaOHin a vacuum and at room temperature. The computational analysis of the free energy of

  5. Errors in measurements of 222Rn in methane and carbon dioxide using scintillation cells calibrated for 222Rn in air.

    PubMed

    Jenkins, Phillip H; Burkhart, James F; Camley, Robert E

    2014-03-01

    Scintillation cells are used typically for measuring the concentration of (222)Rn in air and are calibrated for that purpose. However, scintillation cells are sometimes used for measuring (222)Rn in natural gas or carbon dioxide. The counting efficiencies of scintillation cells for measurements of (222)Rn in these gases should be different from those for measuring (222)Rn in air because the ranges of alpha particles emitted by (222)Rn and its progeny are greater in methane and smaller in carbon dioxide than in air. If these effects are not taken into consideration, measurements of (222)Rn in natural gas will be biased high and in carbon dioxide will be biased low. The authors previously investigated the effects of barometric pressure on measurements of (222)Rn in air using scintillation cells. A modeling technique was used in a previous study to calculate theoretical errors that would result if atmospheric pressure were not considered. In the current study, the same modeling technique was used to calculate theoretical errors that would be made for measurements of (222)Rn in methane and carbon dioxide if the calibration for (222)Rn in air were used. Results are presented for four types of scintillation cells of varying geometries and for barometric pressures representative of four elevations ranging from sea level to 1,963 m (6,440 feet). These results indicate that the errors introduced by the ranges of the alpha particles in gases different from air can be significant. Depending on the type of cell and the local pressure, a measurement of (222)Rn in methane may be biased high by 2-7%, while a measurement of (222)Rn in CO2 may be biased low by 15-20% if the calibration for (222)Rn in air is used. PMID:25208015

  6. Understanding Moisture and Carbon Dioxide Involved Interfacial Reactions on Electrochemical Performance of Lithium-Air Batteries Catalyzed by Gold/Manganese-Dioxide.

    PubMed

    Wang, Guoqing; Huang, Liliang; Liu, Shuangyu; Xie, Jian; Zhang, Shichao; Zhu, Peiyi; Cao, Gaoshao; Zhao, Xinbing

    2015-11-01

    Lithium-air (Li-air) battery works essentially based on the interfacial reaction of 2Li + O2 ↔ Li2O2 on the catalyst/oxygen-gas/electrolyte triphase interface. Operation of Li-air batteries in ambient air still remains a great challenge despite the recent development, because some side reactions related to moisture (H2O) and carbon dioxide (CO2) will occur on the interface with the formation of some inert byproducts on the surface of the catalyst. In this work, we investigated the effect of H2O and CO2 on the electrochemical performance of Li-air batteries to evaluate the practical operation of the batteries in ambient air. The use of a highly efficient gold/δ-manganese-dioxide (Au/δ-MnO2) catalyst helps to understand the intrinsic mechanism of the effect. We found that H2O has a more detrimental influence than CO2 on the battery performance when operated in ambient air. The battery operated in simulated dry air can sustain a stable cycling up to 200 cycles at 400 mA g(-1) with a relatively low polarization, which is comparable with that operated in pure O2. This work provides a possible method to operate Li-air batteries in ambient air by using optimized catalytic electrodes with a protective layer, for example a hydrophobic membrane. PMID:26466174

  7. Indoor air quality assessment of daycare facilities with carbon dioxide, temperature, and humidity as indicators.

    PubMed

    Ferng, Shiaw-Fen; Lee, Li-Wen

    2002-11-01

    Poor indoor air quality (IAQ) in daycare facilities affects both attending children and care providers. Incident rates of upper-respiratory-tract infections have been reported to be higher in children who attend daycare. Excessive carbon dioxide (CO2) exposure can cause several health effects and even sudden infant death. For this study, 26 facilities were randomly selected in a Midwestern county of the United States. CO2, room temperature, and relative humidity were used as indicators for IAQ and comfort levels. These IAQ parameters were continuously monitored for eight hours at each facility by a direct-reading instrument that was calibrated before each measurement. More than 50 percent of the facilities had an average CO2 level over the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) standard of 1,000 parts per million (ppm). For temperature and relative humidity, respectively, 42.3 percent and 15.4 percent of facilities were outside of the ASHRAE-recommended comfort zones. The nap-time average CO2 level was about 117 ppm higher than the non-nap-time level. The increment of the nap-time CO2 level in the sleeping-only room over the level in multipurpose rooms was statistically significant (p < .05). According to stepwise multiple regression analysis, nap-time CO2 level was predicted by CO2 level before occupancy, nap-time average temperature, carbon monoxide, and child density (R2 = .83). It is recommended that an appropriate IAQ standard for daycare facilities be established and that children should not be placed in a completely isolated room during nap time. PMID:12415886

  8. The carbon dioxide cycle

    USGS Publications Warehouse

    James, P.B.; Hansen, G.B.; Titus, T.N.

    2005-01-01

    The seasonal CO2 cycle on Mars refers to the exchange of carbon dioxide between dry ice in the seasonal polar caps and gaseous carbon dioxide in the atmosphere. This review focuses on breakthroughs in understanding the process involving seasonal carbon dioxide phase changes that have occurred as a result of observations by Mars Global Surveyor. ?? 2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  9. Background component of carbon dioxide concentration in the near-surface air

    NASA Astrophysics Data System (ADS)

    Aref'ev, V. N.; Kamenogradsky, N. Ye.; Kashin, F. V.; Shilkin, A. V.

    2014-11-01

    The data on measurements of carbon dioxide concentrations in the near-surface air in the territory of the European part of Russia using Fourier transform spectroscopy are presented. Analysis of these data showed that temporal variations in CO2 concentrations included ˜18% of relatively high, short-lived concentrations that appear during temperature inversions and fires. The measurement results are separated into the regional natural background CO2 concentration and the anthropogenic admixture. The seasonal component is distinguished in the background CO2 concentration. The maxima and minima of seasonal CO2 variations fall most often within February and July, respectively, at an average amplitude of 20.2 ± 3.8 ppm. The coefficient of pair correlation between seasonal CO2 concentrations and temperature is -0.85. Spectral analysis revealed a large number of composite oscillations of the background CO2 concentration, from 2 to 126 months in period. A simple model using the parameters of these oscillations describes the temporal variations in background CO2 concentration with an error of less than 1%. The anthropogenic admixture of CO2 into the atmosphere consists of a random component and a long-term trend. For 13 years of observations, the anthropogenic admixture was ˜33 ppm at an average growth rate of ˜2.04 ppm/yr.

  10. Soil air carbon dioxide and nitrous oxide concentrations in profiles under tallgrass prairie and cultivation

    SciTech Connect

    Sotomayor, D.; Rice, C.W.

    1999-05-01

    Assessing the dynamics of gaseous production in soils is of interest because they are important sources and sinks of greenhouse gases. Changes in soil air carbon dioxide (CO{sub 2}) and nitrous oxide (N{sub 2}O) concentrations were studied in a Reading silt loam under prairie and cultivation. Concentrations were measured in situ over a 17-mo period to a depth of 3 m. Multilevel samples permitted collection of gases with subsequent measurement by gas chromatography in the laboratory. Soil air N{sub 2}O concentrations were near atmospheric levels for a majority of the study period in the prairie site but were significantly higher in the cultivated site. Annual mean N{sub 2}O concentrations were 0.403 and 1.09 {micro}L L{sup {minus}1} in the prairie and cultivated sites, respectively. Soil air CO{sub 2} annual mean concentrations were 1.56 {times} 10{sup 4} and 1.10 {times} 10{sup 4} {micro}L L{sup {minus}1} and ranged from 0.096 {times} 10{sup 4} to 6.45 {times} 10{sup 4} {micro}L L{sup {minus}1} and 0.087 {times} 10{sup 4} to 3.59 {times} 10{sup 4} {micro}L L{sup {minus}1} in the prairie and cultivated sites, respectively. Concentrations generally increased with depth, with maximum soil air N{sub 2}O and CO{sub 2} concentrations at 1.0 m in the prairie site and 0.5 m in the cultivated site. Nitrous oxide in the cultivated site and CO{sub 2} at both sites did not change markedly over winter months, but CO{sub 2} and N{sub 2}O concentrations reached maximums during the summer months and decreased as the year progressed. Although soil air concentrations peaked and decreased faster at shallower depths, deeper depths exhibited relative maximum concentrations for longer time periods.

  11. A ballistic investigation of the aerodynamic characteristics of a blunt vehicle at hypersonic speeds in carbon dioxide and air

    NASA Technical Reports Server (NTRS)

    Packard, James D.; Griffith, Wayland C.; Yates, Leslie A.; Strawa, Anthony W.

    1992-01-01

    Missions to Mars require the successful development of aerobraking technology, and therefore a blunt cone representative of aerobrake shapes is investigated. Ballistic tests of the Pioneer Venus configuration are conducted in carbon dioxide and air at Mach numbers from 7 to 20 and Reynolds numbers from 0.1 x 10 exp 5 to 4 x 10 exp 6. Experimental results show that for defined conditions aerodynamic research can be conducted in air rather than carbon dioxide, providing savings in time and money. In addition, the results offer a prediction of flight aerodynamics during entry into the Martian atmosphere. Also discussed is a comparison of results from two data-reduction techniques showing that a five-degree-of-freedom routine employing weighted least-squares with differential corrections analyzes ballistic data more accurately.

  12. Hydrogen oxidation mechanism with applications to (1) the chaperon efficiency of carbon dioxide and (2) vitiated air testing

    NASA Technical Reports Server (NTRS)

    Brabbs, Theodore A.; Lezberg, Erwin A.; Bittker, David A.; Robertson, Thomas F.

    1987-01-01

    Ignition delay times for the hydrogen/oxygen/carbon dioxide/argon system were obtained behind reflected shock waves. A detailed kinetic mechanism modeled the experimental hydrogen/oxygen data, Skinner and Ringrose's high-pressure data, and Slack and Grillo's hydrogen/air data. A carbon dioxide chaperon efficiency of 7.0 +/- 0.2 was determined. The reaction pathway H2O yields H2O2 yields OH yields H was required to model the high-pressure data. It is suggested that some of the lowest temperature data points (1.0 and 0.5 atm) for Slack and Grillo's hydrogen/air experiments are in error. It was found that the technique of simplifying a detailed kinetic mechanism for a limited range of experimental data may render the model useless for other test conditions.

  13. Separation of root respiration from total soil respiration using carbon-13 labelling during free-air carbon dioxide enrichment (FACE)

    SciTech Connect

    Andrews, J.A.; Harrison, K.G.; Matamala, R.; Schlesinger, W.H.

    1999-10-01

    Soil respiration constitutes a major component of the global carbon cycle and is likely to be altered by climate change. However, there is an incomplete understanding of the extent to which various processes contribute to total soil respiration, especially the contributions of root and rhizosphere respiration. Here, using a stable carbon isotope tracer, the authors separate the relative contributions of root and soil heterotrophic respiration to total soil respiration in situ. The Free-Air Carbon dioxide Enrichment (FACE) facility in the Duke University Forest (NC) fumigates plots of an undisturbed loblolly pine (Pinus taeda L.) forest with CO{sub 2} that is strongly depleted in {sup 13}C. This labeled CO{sub 2} is found in the soil pore space through live root and mycorrhizal respiration and soil heterotroph respiration of labile root exudates. By measuring the depletion of {sup 13}CO{sub 2} in the soil system, the authors found that the rhizosphere contribution to soil CO{sub 2} reflected the distribution of fine roots in the soil and that late in the growing season roots contributed 55% of total soil respiration at the surface. This estimate may represent an upper limit on the contribution of roots to soil respiration because high atmospheric CO{sub 2} often increases in root density and/or root activity in the soil.

  14. Free-air carbon dioxide enrichment of soybean: influence of crop variety on residue decomposition.

    PubMed

    Prior, S A; Torbert, H A; Runion, G B; Rogers, H H; Ort, D R; Nelson, R L

    2006-01-01

    Elevated atmospheric CO2 can result in larger plants returning greater amounts of residue to the soil. However, the effects of elevated CO2 on carbon (C) and nitrogen (N) cycling for different soybean varieties have not been examined. Aboveground residue of eight soybean [Glycine max (L.) Merr.] varieties was collected from a field study where crops had been grown under two different atmospheric CO2 levels [370 micromol mol(-1) (ambient) and 550 micromol mol(-1) (free-air carbon dioxide enrichment, FACE)]. Senesced residue material was used in a 60-d laboratory incubation study to evaluate potential C and N mineralization. In addition to assessing the overall effects of CO2 level and variety, a few specific variety comparisons were also made. Across varieties, overall residue N concentration was increased by FACE, but residue C concentration was only slightly increased. Overall residue C to N ratio was lower under FACE and total mineralized N was increased by FACE, suggesting that increased N2 fixation impacted residue decomposition; total mineralized C was also slightly increased by FACE. Across CO2 levels, varietal differences were also observed with the oldest variety having the lowest residue N concentration and highest residue C to N ratio; mineralized N was lowest in the oldest variety, illustrating the influence of high residue C to N ratio. It appears (based on our few specific varietal comparisons) that the breeding selection process may have resulted in some varietal differences in residue quality which can result in increased N or C mineralization under elevated CO2 conditions. This limited number of varietal comparisons indicated that more work investigating varietal influences on soil C and N cycling under elevated CO2 conditions is required. PMID:16825467

  15. Evaluation of Refrigerating and Air Conditioning Devices in Energy Cascade Systems under the Restriction of Carbon Dioxide Emissions

    NASA Astrophysics Data System (ADS)

    Shimazaki, Yoichi; Akisawa, Atsushi; Kashiwagi, Takao

    It is necessary to introduce energy cascade systems into the industrial sector in Japan to reduce carbon dioxide emissions. The aim of this study is to evaluate the refrigerating and air conditioning devices in cases of introducing both energy cascade systems and thermal recycling systems in industries located around urban areas. The authors have developed an energy cascade model based on linear programming so as to minimize the total system costs with carbon taxes. Five cases are investigated. Limitation of carbon dioxide emissions results in the enhancement of heat cascading, where high temperature heat is supplied for process heating while low temperature one is shifted to refrigeration. It was found that increasing the amount of garbage combustor waste heat can reduce electric power for the turbo refrigerator by promoting waste heat driven ammonia absorption refrigerator.

  16. Carbon Dioxide and Climate.

    ERIC Educational Resources Information Center

    Brewer, Peter G.

    1978-01-01

    The amount of carbon dioxide in the atmosphere is increasing at a rate that could cause significant warming of the Earth's climate in the not too distant future. Oceanographers are studying the role of the ocean as a source of carbon dioxide and as a sink for the gas. (Author/BB)

  17. Carbon Dioxide Fountain

    ERIC Educational Resources Information Center

    Kang, Seong-Joo; Ryu, Eun-Hee

    2007-01-01

    This article presents the development of a carbon dioxide fountain. The advantages of the carbon dioxide fountain are that it is odorless and uses consumer chemicals. This experiment also is a nice visual experiment that allows students to see evidence of a gaseous reagent being consumed when a pressure sensor is available. (Contains 3 figures.)…

  18. Out of thin air: Sensory detection of oxygen and carbon dioxide

    PubMed Central

    Scott, Kristin

    2011-01-01

    Oxygen and carbon dioxide levels vary in different environments and locally fluctuate during respiration and photosynthesis. Recent studies in diverse animals have identified sensory neurons that detect these external variations and direct a variety of behaviors. Detection allows animals to stay within a preferred environment as well as identify potential food or dangers. The complexity of sensation is reflected in the fact that neurons compartmentalize detection into increases, decreases, short-range and long-range cues. Animals also adjust their responses to these prevalent signals in context of other cues, allowing for flexible behaviors. In general, the molecular mechanisms for detection suggest that sensory neurons adopted ancient strategies for cellular detection and coupled them to brain activity and behavior. This review highlights the multiple strategies that animals use to extract information about their environment from variations in oxygen and carbon dioxide. PMID:21262460

  19. Extraction and detection of pesticide residues from air filter inserts using supercritical carbon dioxide

    SciTech Connect

    Zemanian, T.S.; Robins, W.H.; Lee, R.N.; Wright, B.W.

    1994-10-01

    Trace quantities of airborne herbicide residues were collected on adsorbent bed cartridges and were subsequently extracted from the adsorbent using supercritical carbon dioxide. An apparatus was constructed to facilitate the extraction and recovery of the desired analytes. The resulting extracts were analyzed using gas chromatography/mass spectrometry (GC/MS) or high performance liquid chromatography (HPLC) techniques. Results are presented for a series of analytes representative of common commercial pesticides or herbicides.

  20. Development and Testing of a Temperature-swing Adsorption Compressor for Carbon Dioxide in Closed-loop Air Revitalization Systems

    NASA Technical Reports Server (NTRS)

    Mulloth, Lila M.; Rosen, Micha; Affleck, David; LeVan, M. Douglas; Wang, Yuan

    2005-01-01

    The air revitalization system of the International Space Station (ISS) operates in an open loop mode and relies on the resupply of oxygen and other consumables from earth for the life support of astronauts. A compressor is required for delivering the carbon dioxide from a removal assembly to a reduction unit to recover oxygen and thereby dosing the air-loop. We have developed a temperature-swing adsorption compressor (TSAC) that is energy efficient, quiet, and has no rapidly moving parts for performing these tasks. The TSAC is a solid-state compressor that has the capability to remove CO2 from a low- pressure source, and subsequently store, compress, and deliver at a higher pressure as required by a processor. The TSAC is an ideal interface device for CO2 removal and reduction units in the air revitalization loop of a spacecraft for oxygen recovery. This paper discusses the design and testing of a TSAC for carbon dioxide that has application in the ISS and future spacecraft for closing the air revitalization loop.

  1. Distributions and air-sea fluxes of carbon dioxide in the Western Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Gao, Zhongyong; Chen, Liqi; Sun, Heng; Chen, Baoshan; Cai, Wei-Jun

    2012-12-01

    The uptake of carbon dioxide (CO2) by the Arctic Ocean is most likely increasing because of the rapid sea-ice retreat that lifted the barriers preventing gas exchange and light penetration for biological growth. Measurements of atmospheric and surface sea water partial pressure of CO2 (pCO2) were conducted during the Chinese National Arctic Research Expedition (CHINARE) cruises from July to September in 2003 and 2008. The latitudinal distribution of pCO2 along the 169°W transect showed a below-atmopsheric pCO2 level in most of the Western Arctic Ocean, with distinct regional differences from Bering Strait northward to the Central Acrctic Ocean. The average air-sea CO2 fluxes on the shelf and slope of the Chukchi Sea were -17.0 and -8.1 mmol m-2 d-1 respectively. In the ice-free zone, the partially ice-covered zone, and the heavily ice-covered zone of the Canada Basin, the fluxes were -4.2, -8.6, -2.5 mmol m-2 d-1 respectively. These rates are lower than other recent estimates. Our new results not only confirmed previous observations that most areas of the Western Arctic Ocean were a CO2 sink in general, but they also revealed that the previously unsampled central basins were a moderate CO2 sink. Analysis of controlling factors in different areas shows that pCO2 in Bering Strait was influenced not only by the Bering inflow waters but also by the high biological production. However, pCO2 fluctuated sharply because of strong water mixing both laterally and vertically. In the marginal ice zone (Chukchi Sea), pCO2 was controlled by ice melt and biological production, both of which would decrease pCO2 onshore of the ice edge. In the nearly ice-free southern Canada Basin, pCO2 increasd latitudinally as a result of atmospheric CO2 uptake due to intensive gas exchange, increased temperature, and decresed biological CO2 uptake due to limited nutrient supply. Finally, pCO2 was moderately lower than the atmospheric value and was relatively stable under the ice sheet of the

  2. Carbon dioxide removal process

    DOEpatents

    Baker, Richard W.; Da Costa, Andre R.; Lokhandwala, Kaaeid A.

    2003-11-18

    A process and apparatus for separating carbon dioxide from gas, especially natural gas, that also contains C.sub.3+ hydrocarbons. The invention uses two or three membrane separation steps, optionally in conjunction with cooling/condensation under pressure, to yield a lighter, sweeter product natural gas stream, and/or a carbon dioxide stream of reinjection quality and/or a natural gas liquids (NGL) stream.

  3. Integrated Testing of a Carbon Dioxide Removal Assembly and a Temperature-Swing Adsorption Compressor for Closed-Loop Air Revitalization

    NASA Technical Reports Server (NTRS)

    Knox, J. C.; Mulloth, Lila; Frederick, Kenneth; Affleck, Dave

    2003-01-01

    Accumulation and subsequent compression of carbon dioxide that is removed from space cabin are two important processes involved in a closed-loop air revitalization scheme of the International Space Station (ISS). The carbon dioxide removal assembly (CDRA) of ISS currently operates in an open loop mode without a compressor. This paper describes the integrated test results of a flight-like CDRA and a temperature-swing adsorption compressor (TSAC) for carbon dioxide removal and compression. The paper provides details of the TSAC operation at various CO2 loadings and corresponding performance of CDRA.

  4. Environmental carbon dioxide control

    NASA Technical Reports Server (NTRS)

    Onischak, M.; Baker, B.; Gidaspow, D.

    1974-01-01

    A study of environmental carbon dioxide control for NASA EVA missions found solid potassium carbonate to be an effective regenerable absorbent in maintaining low carbon dioxide levels. The supported sorbent was capable of repeated regeneration below 150 C without appreciable degradation. Optimum structures in the form of thin pliable sheets of carbonate, inert support and binder were developed. Interpretation of a new solid-gas pore closing model helped predict the optimum sorbent and analysis of individual sorbent sheet performance in a thin rectangular channel sorber can predict packed bed performance.

  5. Carbon dioxide sensor

    DOEpatents

    Dutta, Prabir K.; Lee, Inhee; Akbar, Sheikh A.

    2011-11-15

    The present invention generally relates to carbon dioxide (CO.sub.2) sensors. In one embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor that incorporates lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3). In another embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor has a reduced sensitivity to humidity due to a sensing electrode with a layered structure of lithium carbonate and barium carbonate. In still another embodiment, the present invention relates to a method of producing carbon dioxide (CO.sub.2) sensors having lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3).

  6. The Development of Models for Carbon Dioxide Reduction Technologies for Spacecraft Air Revitalization

    NASA Technical Reports Server (NTRS)

    Swickrath, Michael J.; Anderson, Molly

    2012-01-01

    Through the respiration process, humans consume oxygen (O2) while producing carbon dioxide (CO2) and water (H2O) as byproducts. For long term space exploration, CO2 concentration in the atmosphere must be managed to prevent hypercapnia. Moreover, CO2 can be used as a source of oxygen through chemical reduction serving to minimize the amount of oxygen required at launch. Reduction can be achieved through a number of techniques. NASA is currently exploring the Sabatier reaction, the Bosch reaction, and co- electrolysis of CO2 and H2O for this process. Proof-of-concept experiments and prototype units for all three processes have proven capable of returning useful commodities for space exploration. All three techniques have demonstrated the capacity to reduce CO2 in the laboratory, yet there is interest in understanding how all three techniques would perform at a system level within a spacecraft. Consequently, there is an impetus to develop predictive models for these processes that can be readily rescaled and integrated into larger system models. Such analysis tools provide the ability to evaluate each technique on a comparable basis with respect to processing rates. This manuscript describes the current models for the carbon dioxide reduction processes under parallel developmental efforts. Comparison to experimental data is provided were available for verification purposes.

  7. The Development of Models for Carbon Dioxide Reduction Technologies for Spacecraft Air Revitalization

    NASA Technical Reports Server (NTRS)

    Swickrath, Michael J.; Anderson, Molly

    2011-01-01

    Through the respiration process, humans consume oxygen (O2) while producing carbon dioxide (CO2) and water (H2O) as byproducts. For long term space exploration, CO2 concentration in the atmosphere must be managed to prevent hypercapnia. Moreover, CO2 can be used as a source of oxygen through chemical reduction serving to minimize the amount of oxygen required at launch. Reduction can be achieved through a number of techniques. The National Aeronautics and Space Administration (NASA) is currently exploring the Sabatier reaction, the Bosch reaction, and co-electrolysis of CO2 and H2O for this process. Proof-of-concept experiments and prototype units for all three processes have proven capable of returning useful commodities for space exploration. While all three techniques have demonstrated the capacity to reduce CO2 in the laboratory, there is interest in understanding how all three techniques would perform at a system-level within a spacecraft. Consequently, there is an impetus to develop predictive models for these processes that can be readily re-scaled and integrated into larger system models. Such analysis tools provide the ability to evaluate each technique on a comparable basis with respect to processing rates. This manuscript describes the current models for the carbon dioxide reduction processes under parallel developmental e orts. Comparison to experimental data is provided were available for veri cation purposes.

  8. Carbon dioxide recycling

    EPA Science Inventory

    The recycling of carbon dioxide to methanol and dimethyl ether is seen to offer a substantial route to renewable and environmentally carbon neutral fuels. One of the authors has championed the “Methanol Economy" in articles and a book. By recycling ambient CO2, the authors argue ...

  9. Polymeric Carbon Dioxide

    SciTech Connect

    Yoo, C-S.

    1999-11-02

    Synthesis of polymeric carbon dioxide has long been of interest to many chemists and materials scientists. Very recently we discovered the polymeric phase of carbon dioxide (called CO{sub 2}-V) at high pressures and temperatures. Our optical and x-ray results indicate that CO{sub 2}-V is optically non-linear, generating the second harmonic of Nd: YLF laser at 527 nm and is also likely superhard similar to cubic-boron nitride or diamond. CO{sub 2}-V is made of CO{sub 4} tetrahedra, analogous to SiO{sub 2} polymorphs, and is quenchable at ambient temperature at pressures above 1 GPa. In this paper, we describe the pressure-induced polymerization of carbon dioxide together with the stability, structure, and mechanical and optical properties of polymeric CO{sub 2}-V. We also present some implications of polymeric CO{sub 2} for high-pressure chemistry and new materials synthesis.

  10. Easily regenerable solid adsorbents based on polyamines for carbon dioxide capture from the air.

    PubMed

    Goeppert, Alain; Zhang, Hang; Czaun, Miklos; May, Robert B; Prakash, G K Surya; Olah, George A; Narayanan, S R

    2014-05-01

    Adsorbents prepared easily by impregnation of fumed silica with polyethylenimine (PEI) are promising candidates for the capture of CO2 directly from the air. These inexpensive adsorbents have high CO2 adsorption capacity at ambient temperature and can be regenerated in repeated cycles under mild conditions. Despite the very low CO2 concentration, they are able to scrub efficiently all CO2 out of the air in the initial hours of the experiments. The influence of parameters such as PEI loading, adsorption and desorption temperature, particle size, and PEI molecular weight on the adsorption behavior were investigated. The mild regeneration temperatures required could allow the use of waste heat available in many industrial processes as well as solar heat. CO2 adsorption from the air has a number of applications. Removal of CO2 from a closed environment, such as a submarine or space vehicles, is essential for life support. The supply of CO2-free air is also critical for alkaline fuel cells and batteries. Direct air capture of CO2 could also help mitigate the rising concerns about atmospheric CO2 concentration and associated climatic changes, while, at the same time, provide the first step for an anthropogenic carbon cycle. PMID:24644023

  11. Easily Regenerable Solid Adsorbents Based on Polyamines for Carbon Dioxide Capture from the Air

    SciTech Connect

    Goeppert, A; Zhang, H; Czaun, M; May, RB; Prakash, GKS; Olah, GA; Narayanan, SR

    2014-03-18

    Adsorbents prepared easily by impregnation of fumed silica with polyethylenimine (PEI) are promising candidates for the capture of CO2 directly from the air. These inexpensive adsorbents have high CO2 adsorption capacity at ambient temperature and can be regenerated in repeated cycles under mild conditions. Despite the very low CO2 concentration, they are able to scrub efficiently all CO2 out of the air in the initial hours of the experiments. The influence of parameters such as PEI loading, adsorption and desorption temperature, particle size, and PEI molecular weight on the adsorption behavior were investigated. The mild regeneration temperatures required could allow the use of waste heat available in many industrial processes as well as solar heat. CO2 adsorption from the air has a number of applications. Removal of CO2 from a closed environment, such as a submarine or space vehicles, is essential for life support. The supply of CO2-free air is also critical for alkaline fuel cells and batteries. Direct air capture of CO2 could also help mitigate the rising concerns about atmospheric CO2 concentration and associated climatic changes, while, at the same time, provide the first step for an anthropogenic carbon cycle.

  12. Indoor Air Quality in Urban and Rural Preschools in Upper Silesia, Poland: Particulate Matter and Carbon Dioxide

    PubMed Central

    Mainka, Anna; Zajusz-Zubek, Elwira

    2015-01-01

    Indoor air quality (IAQ) in preschools is an important public health challenge. Particular attention should be paid to younger children, because they are more vulnerable to air pollution than higher grade children and because they spend more time indoors. Among air pollutants, particulate matter (PM) is of the greatest interest mainly due to its acute and chronic effects on children’s health. In addition, carbon dioxide (CO2) levels indicate ventilation conditions. In this paper, we present the concentrations of PM (PM1, PM2.5, PM10 and total—TSP) and CO2 monitored in four naturally ventilated nursery schools located in the area of Gliwice, Poland. The nursery schools were selected to characterize areas with different degrees of urbanization and traffic densities during the winter season. The results indicate the problem of elevated concentrations of PM inside the examined classrooms, as well as that of high levels of CO2 exceeding 1000 ppm in relation to outdoor air. The characteristics of IAQ were significantly different, both in terms of classroom occupation (younger or older children) and of localization (urban or rural). To evaluate the children’s exposure to poor IAQ, indicators based on air quality guidelines were proposed to rank classrooms according to their hazard on the health of children. PMID:26184249

  13. Indoor Air Quality in Urban and Rural Preschools in Upper Silesia, Poland: Particulate Matter and Carbon Dioxide.

    PubMed

    Mainka, Anna; Zajusz-Zubek, Elwira

    2015-07-01

    Indoor air quality (IAQ) in preschools is an important public health challenge. Particular attention should be paid to younger children, because they are more vulnerable to air pollution than higher grade children and because they spend more time indoors. Among air pollutants, particulate matter (PM) is of the greatest interest mainly due to its acute and chronic effects on children's health. In addition, carbon dioxide (CO2) levels indicate ventilation conditions. In this paper, we present the concentrations of PM (PM1, PM2.5, PM10 and total-TSP) and CO2 monitored in four naturally ventilated nursery schools located in the area of Gliwice, Poland. The nursery schools were selected to characterize areas with different degrees of urbanization and traffic densities during the winter season. The results indicate the problem of elevated concentrations of PM inside the examined classrooms, as well as that of high levels of CO2 exceeding 1000 ppm in relation to outdoor air. The characteristics of IAQ were significantly different, both in terms of classroom occupation (younger or older children) and of localization (urban or rural). To evaluate the children's exposure to poor IAQ, indicators based on air quality guidelines were proposed to rank classrooms according to their hazard on the health of children. PMID:26184249

  14. Air plasma gasification of RDF as a prospective method for reduction of carbon dioxide emission

    NASA Astrophysics Data System (ADS)

    Bratsev, A. N.; Kumkova, I. I.; Kuznetsov, V. A.; Popov, V. E.; Shtengel', S. V.; Ufimtsev, A. A.

    2011-03-01

    Waste disposal dumps are one of sources of carbonic gas penetration in the atmosphere. The waste is treated into RDF (refuse-derived fuel) and used in boilers for electric power or heat generation for decrease in carbonic gas emissions in the atmosphere. In industry power stations on the basis of the combined cycle have the highest efficiency of burning. The paper deals with the application of an air-plasma gasifier using the down draft scheme of RDF transformation into synthesis gas, which afterwards can be used in the combined cycle. Results of calculations of the process characteristics for various RDF compositions are presented. The advantage of the plasma method in comparison with autothermal one is shown. Experimental data are shown.

  15. BIFoR FACE: A Free-Air Carbon Dioxide Enrichment (FACE) facility in old-growth temperate deciduous woodland

    NASA Astrophysics Data System (ADS)

    MacKenzie, Rob; Thomas, Rick; Ellsworth, David; Hemming, Debbie; Crous, Kristine; Blaen, Phillip; Poynter, Alex; Blenkhorn, Daniel; Pope, Francis

    2016-04-01

    The Birmingham Institute of Forest research (BIFoR) focuses on fundamental physical, biological, ecological, social and cultural research of direct relevance to forested landscapes worldwide. A core platform for BIFoR is a Free-Air Carbon Dioxide Enrichment (FACE) facility, with which we study the ten-year response of a mature temperate deciduous forest ecosystem to a 150-ppmv step-change in atmospheric [CO2]. BIFoR FACE is being established in Mill Haft, a mature (~150 year-old) oak (Quercus robur) and hazel (Corylus avellana) coppice-with-standards woodland in central England, UK. The facility enables elevated CO2 (eCO2) treatments to be introduced in 30 m diameter rings (3 treatment plots, 3 fully-replicated control plots, and 3 unmodified ambient controls). Primary research questions focus on carbon uptake and storage, corresponding nutrient limitations, and biodiversity and ecosystem responses to elevated CO2. Here we describe the facility and experimental design, and present baseline data collected through the growing season of 2015. These data include: biophysical tree properties; atmospheric CO2/H2O fluxes; airborne and ground laser scatterometry; leaf area index; geophysical survey data; canopy phenology; soil and water chemical and physical properties; and invertebrate surveys. Data from an intensive campaign conducted during august 2015 are also shown, including in- and above- canopy characterisation of biogenic VOCs using a Proton Transfer Reaction Mass Spectrometer, aerosol loading including bioaerosols, and air quality. Further campaign results are presented from leaf level photosynthetic carbon-dioxide response curve (A/Ci) performed at different canopy heights on oak trees, and on the dominant understory species - hazel and sycamore (Acer pseudoplatanus) across the site. BIFoR FACE is intended to be an international facility for forest science - ideas for collaborations are encouraged. Please see http

  16. Carbon Dioxide Laser Guidelines

    PubMed Central

    Krupa Shankar, DS; Chakravarthi, M; Shilpakar, Rachana

    2009-01-01

    The carbon dioxide (CO2) laser is a versatile tool that has applications in ablative lasing and caters to the needs of routine dermatological practice as well as the aesthetic, cosmetic and rejuvenation segments. This article details the basics of the laser physics as applicable to the CO2 laser and offers guidelines for use in many of the above indications. PMID:20808594

  17. Carbon dioxide laser guidelines.

    PubMed

    Krupa Shankar, Ds; Chakravarthi, M; Shilpakar, Rachana

    2009-07-01

    The carbon dioxide (CO(2)) laser is a versatile tool that has applications in ablative lasing and caters to the needs of routine dermatological practice as well as the aesthetic, cosmetic and rejuvenation segments. This article details the basics of the laser physics as applicable to the CO(2) laser and offers guidelines for use in many of the above indications. PMID:20808594

  18. Bench Remarks: Carbon Dioxide.

    ERIC Educational Resources Information Center

    Bent, Henry A.

    1987-01-01

    Discusses the properties of carbon dioxide in its solid "dry ice" stage. Suggests several demonstrations and experiments that use dry ice to illustrate Avogadro's Law, Boyle's Law, Kinetic-Molecular Theory, and the effects of dry ice in basic solution, in limewater, and in acetone. (TW)

  19. Operation of a breadboard liquid-sorbent/membrane-contactor system for removing carbon dioxide and water vapor from air

    NASA Technical Reports Server (NTRS)

    Mccray, Scott B.; Ray, Rod; Newbold, David D.; Millard, Douglas L.; Friesen, Dwayne T.; Foerg, Sandra

    1992-01-01

    Processes to remove and recover carbon dioxide (CO2) and water vapor from air are essential for successful long-duration space missions. This paper presents results of a developmental program focused on the use of a liquid-sorbent/membrane-contactor (LSMC) system for removal of CO2 and water vapor from air. In this system, air from the spacecraft cabin atmosphere is circulated through one side of a hollow-fiber membrane contactor. On the other side of the membrane contactor is flowed a liquid sorbent, which absorbs the CO2 and water vapor from the feed air. The liquid sorbent is then heated to desorb the CO2 and water vapor. The CO2 is subsequently removed from the system as a concentrated gas stream, whereas the water vapor is condensed, producing a water stream. A breadboard system based on this technology was designed and constructed. Tests showed that the LSMC breadboard system can produce a CO2 stream and a liquid-water stream. Details are presented on the operation of the system, as well as the effects on performance of variations in feed conditions.

  20. Chemical Extraction of Carbon Dioxide From Air: A Strategy to Avoid Climate Change and Sustain Fossil Energy?

    NASA Astrophysics Data System (ADS)

    Dubey, M. K.; Ziock, H.; Rueff, G.; Colman, J.; Smith, W. S.

    2002-12-01

    Fossil energy use has benefited humankind but also threatens our environment. It has increased atmospheric carbon dioxide (CO2) levels from 280 ppm to 370 ppm, over the past century. This rise has been linked to with observed ocean acidification and global warming. Projections indicate that atmospheric CO2 could reach 540 to 970 ppm in 2100, with significant effects on our earth system. Given that fossil fuels are plentiful, cost-effective, and energy rich their use will be limited by our ability to mitigate their environmental impact. Carbon management provides potential solutions to this. Current approaches to manage carbon focus on capturing CO2 from large point sources such as power plants. They are limited because they fail to address emissions from transportation and the myriad of dispersed sources that amount to about half of all emissions. To solve this problem we have proposed and are developing direct CO2 extraction from air as a means to capture emissions from all sources [1-3]. It preserves our fuel distribution and transportation systems, and in principle could allow us to restore CO2 to pre-industrial levels. Our concept utilizes atmospheric circulation to capture CO2 directly from the dilute stream in air (370 ppm) by binding it to an adsorbent. Subsequent heating releases the bound CO2 as a pure stream suitable for permanent sequestration. For example, this cycle is favorable for Ca(OH)2 which reacts rapidly with CO2 to form CaCO3. The heat to recover CO2 from CaCO3 is 190 kJ/mole of C, less than half the heat of combustion of 500 kJ/ mole of C for coal. The scale of CO2 air-extraction plants to offset global emissions is large but could be manageable, and favorable relative to renewable sources. We report experiments on CO2 uptake by alkaline solutions as a function of pH, contact time, and mixing. Both active and passive mixing conditions are explored. Gram scale quantities of CO2 has been extracted from air by Ca(OH)2 and the product CaCO3

  1. Carbon dioxide adsorbent study

    NASA Technical Reports Server (NTRS)

    Onischak, M.; Baker, B. S.

    1973-01-01

    A study was initiated on the feasibility of using the alkali metal carbonate - bi-carbonate solid-gas reaction to remove carbon dioxide from the atmosphere of an EVA life support system. The program successfully demonstrates that carbon dioxide concentrations could be maintained below 0.1 mole per cent using this chemistry. Further a practical method for distributing the carbonates in a coherent sheet form capable of repeated regeneration (50 cycles) at modest temperatures (423 K), without loss in activity was also demonstrated. Sufficiently high reaction rates were shown to be possible with the carbonate - bi-carbonate system such that EVA hardware could be readily designed. Experimental and design data were presented on the basis of which two practical units were designed. In addition to conventional thermally regenerative systems very compact units using ambient temperature cyclic vacuum regeneration may also be feasible. For a one man - 8 hour EVA unit regenerated thermally at the base ship a system volume of 14 liters is estimated.

  2. Electrochemically regenerable carbon dioxide absorber

    NASA Technical Reports Server (NTRS)

    Woods, R. R.; Marshall, R. D.; Schubert, F. H.; Heppner, D. B.

    1979-01-01

    Preliminary designs were generated for two electrochemically regenerable carbon dioxide absorber concepts. Initially, an electrochemically regenerable absorption bed concept was designed. This concept incorporated the required electrochemical regeneration components in the absorber design, permitting the absorbent to be regenerated within the absorption bed. This hardware was identified as the electrochemical absorber hardware. The second hardware concept separated the functional components of the regeneration and absorption process. This design approach minimized the extravehicular activity component volume by eliminating regeneration hardware components within the absorber. The electrochemical absorber hardware was extensively characterized for major operating parameters such as inlet carbon dioxide partial pressure, process air flow rate, operational pressure, inlet relative humidity, regeneration current density and absorption/regeneration cycle endurance testing.

  3. Summer Ice and Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Kukla, G.; Gavin, J.

    1981-10-01

    The extent of Antarctic pack ice in the summer, as charted from satellite imagery, decreased by 2.5 million square kilometers between 1973 and 1980. The U.S. Navy and Russian atlases and whaling and research ship reports from the 1930's indicate that summer ice conditions earlier in this century were heavier than the current average. Surface air temperatures along the seasonally shifting belt of melting snow between 55 degrees and 80 degrees N during spring and summer were higher in 1974 to 1978 than in 1934 to 1938. The observed departures in the two hemispheres qualitatively agree with the predicted impact of an increase in atmospheric carbon dioxide. However, since it is not known to what extent the changes in snow and ice cover and in temperature can be explained by the natural variability of the climate system or by other processes unrelated to carbon dioxide, a cause-and-effect relation cannot yet be established.

  4. Summer ice and carbon dioxide

    SciTech Connect

    Kukla, G.; Gavin, J.

    1981-10-30

    The extent of Antarctic pack ice in the summer, as charted from satellite imagery, decreased by 2.5 million square kilometers between 1973 and 1980. The U.S. Navy and Russian atlases and whaling and reseach ship reports from the 1930's indicate that summer ice conditions earlier in this century were heavier than the current average. Surface air temperatures along the seasonally shifting belt of melting snow between 55/sup o/ and 80/sup o/N during spring and summer were higher in 1974 to 1978 than in 1934 to 1938. The observed departures in the two hemispheres qualitatively agree with the predicted impact of an increase in atmospheric carbon dioxide. However, since it is not known to what extent the changes in snow and ice cover and in temperature can be explained by the natural variability of the climate system or by other processes unrelated to carbon dioxide, a cause-and-effect relation cannot yet be established.

  5. PHENOLIC CONTENT AND ANTIOXIDANT ACTIVITY OF SUPERCRITICAL CARBON DIOXIDE-TREATED AND AIR-CLASSIFIED OAT BRAN CONCENTRATE MICROWAVE-IRRADIATED IN WATER OR ETHANOL AT VARYING TEMPERATURES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oat bran concentrate (OBC) was defatted with supercritical carbon dioxide (SCD), then microwave-irradiated at 50, 100 or 150 deg C for 10 min in water, 50% or 100% ethanol, and extract pH, soluble solids, phenolic content and antioxidant activity were analyzed. OBC was air-classified into five frac...

  6. A comparison between molten carbonate fuel cells based hybrid systems using air and supercritical carbon dioxide Brayton cycles with state of the art technology

    NASA Astrophysics Data System (ADS)

    Sánchez, D.; Muñoz de Escalona, J. M.; Chacartegui, R.; Muñoz, A.; Sánchez, T.

    A proposal for high efficiency hybrid systems based on molten carbonate fuel cells is presented in this paper. This proposal is based on adopting a closed cycle bottoming gas turbine using supercritical carbon dioxide as working fluid as opposed to open cycle hot air turbines typically used in this type of power generators. First, both bottoming cycles are compared for the same operating conditions, showing that their performances do not differ as much as initially expected, even if the initial objective of reducing compression work is accomplished satisfactorily. In view of these results, a profound review of research and industrial literature is carried out in order to determine realistic specifications for the principal components of the bottoming systems. From this analysis, it is concluded that an appropriate set of specifications must be developed for each bottoming cycle as the performances of compressor, turbine and recuperator differ significantly from one working fluid to another. Thus, when the operating conditions are updated, the performances of the resulting systems show a remarkable advantage of carbon dioxide based systems over conventional air units. Actually, the proposed hybrid system shows its capability to achieve 60% net efficiency, what represents a 10% increase with respect to the reference system.

  7. Carbon Dioxide Landscape

    NASA Technical Reports Server (NTRS)

    2005-01-01

    23 July 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a view of some of the widely-varied terrain of the martian south polar residual cap. The landforms here are composed mainly of frozen carbon dioxide. Each year since MGS arrived in 1997, the scarps that bound each butte and mesa, or line the edges of each pit, in the south polar region, have changed a little bit as carbon dioxide is sublimed away. The scarps retreat at a rate of about 3 meters (3 yards) per martian year. Most of the change occurs during each southern summer.

    Location near: 86.7oS, 9.8oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  8. CARBON DIOXIDE FIXATION.

    SciTech Connect

    FUJITA,E.

    2000-01-12

    Solar carbon dioxide fixation offers the possibility of a renewable source of chemicals and fuels in the future. Its realization rests on future advances in the efficiency of solar energy collection and development of suitable catalysts for CO{sub 2} conversion. Recent achievements in the efficiency of solar energy conversion and in catalysis suggest that this approach holds a great deal of promise for contributing to future needs for fuels and chemicals.

  9. Frozen Carbon Dioxide

    NASA Technical Reports Server (NTRS)

    2005-01-01

    1 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a south polar residual cap landscape, formed in frozen carbon dioxide. There is no place on Earth that one can go to visit a landscape covering thousands of square kilometers with frozen carbon dioxide, so mesas, pits, and other landforms of the martian south polar region are as alien as they are beautiful. The scarps of the south polar region are known from thousands of other MGS MOC images to retreat at a rate of about 3 meters (3 yards) per martian year, indiating that slowly, over the course of the MGS mission, the amount of carbon dioxide in the martian atmosphere has probably been increasing.

    Location near: 86.9oS, 25.5oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  10. Carbon Dioxide Landforms

    NASA Technical Reports Server (NTRS)

    2004-01-01

    19 March 2004 The martian south polar residual ice cap is mostly made of frozen carbon dioxide. There is no place on Earth that a person can go to see the landforms that would be produced by erosion and sublimation of hundreds or thousands of cubic kilometers of carbon dioxide. Thus, the south polar cap of Mars is as alien as alien can get. This image, acquired in February 2004 by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC), shows how the cap appears in summer as carbon dioxide is subliming away, creating a wild pattern of pits, mesas, and buttes. Darker surfaces may be areas where the ice contains impurities, such as dust, or where the surface has been roughened by the removal of ice. This image is located near 86.3oS, 0.8oW. This picture covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the top/upper left.

  11. Extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters by supercritical carbon dioxide

    SciTech Connect

    Schilling, J.B.

    1997-09-01

    Supercritical fluid extraction (SFE) using unmodified carbon dioxide has been explored as an alternative method for the extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters. HEPA filters provide the final stage of containment on many exhaust systems in US Department of Energy (DOE) facilities by preventing the escape of chemical and radioactive materials entrained in the exhausted air. The efficiency of the filters is tested by the manufacturer and DOE using dioctylphthalate (DOP), a substance regulated by the US Environmental Protection Agency under the Resource Conservation and Recovery Act. Therefore, the filters must be analyzed for semivolatile organics before disposal. Ninety-eight acid, base, and neutral semivolatile organics were spiked onto blank HEPA material and extracted using SFE, Soxhlet, automated Soxhlet, and sonication techniques. The SFE conditions were optimized using a Dionex SFE-703 instrument. Average recoveries for the 98 semivolatile compounds are 82.7% for Soxhlet, 74.0% for sonication, 70.2% for SFE, and 62.9% for Soxtec. Supercritical fluid extraction reduces the extraction solvent volume to 10--15 mL, a factor of 20--30 less than Soxhlet and more than 5 times less than Soxtec and sonication. Extraction times of 30--45 min are used compared to 16--18 h for Soxhlet extraction.

  12. [Life support of the Mars exploration crew. Control of a zeolite system for carbon dioxide removal from space cabin air within a closed air regeneration cycle].

    PubMed

    Chekov, Iu F

    2009-01-01

    The author describes a zeolite system for carbon dioxide removal integrated into a closed air regeneration cycle aboard spacecraft. The continuous operation of a double-adsorbent regeneration system with pCO2-dependable productivity is maintained through programmable setting of adsorption (desorption) semicycle time. The optimal system regulation curve is presented within the space of statistical performance family obtained in quasi-steady operating modes with controlled parameters of the recurrent adsorption-desorption cycle. The automatically changing system productivity ensures continuous intake of concentrated CO2. Control of the adsorption-desorption process is based on calculation of the differential adsorption (desorption) heat from gradient of adsorbent and test inert substance temperatures. The adaptive algorithm of digital control is implemented through the standard spacecraft interface with the board computer system and programmable microprocessor-based controllers. PMID:19621802

  13. SOIL AIR CARBON DIOXIDE CONCENTRATIONS IN A NEW ENGLAND SPRUCE-FIR FORESTS

    EPA Science Inventory

    Research and modeling efforts to evaluate soil-soil solution chemical interactions must take into account solution equilibria with soil air CO2. Measurements of soil air CO2 and soil temperature were made in the major horizons of a forest soil in eastern Maine through the 1985 gr...

  14. Nondestructive natural gas hydrate recovery driven by air and carbon dioxide

    PubMed Central

    Kang, Hyery; Koh, Dong-Yeun; Lee, Huen

    2014-01-01

    Current technologies for production of natural gas hydrates (NGH), which include thermal stimulation, depressurization and inhibitor injection, have raised concerns over unintended consequences. The possibility of catastrophic slope failure and marine ecosystem damage remain serious challenges to safe NGH production. As a potential approach, this paper presents air-driven NGH recovery from permeable marine sediments induced by simultaneous mechanisms for methane liberation (NGH decomposition) and CH4-air or CH4-CO2/air replacement. Air is diffused into and penetrates NGH and, on its surface, forms a boundary between the gas and solid phases. Then spontaneous melting proceeds until the chemical potentials become equal in both phases as NGH depletion continues and self-regulated CH4-air replacement occurs over an arbitrary point. We observed the existence of critical methane concentration forming the boundary between decomposition and replacement mechanisms in the NGH reservoirs. Furthermore, when CO2 was added, we observed a very strong, stable, self-regulating process of exchange (CH4 replaced by CO2/air; hereafter CH4-CO2/air) occurring in the NGH. The proposed process will work well for most global gas hydrate reservoirs, regardless of the injection conditions or geothermal gradient. PMID:25311102

  15. Technique for measuring air flow and carbon dioxide flux in large, open-top chambers

    SciTech Connect

    Ham, J.M.; Owensby, C.E.; Coyne, P.I.

    1993-10-01

    Open-Top Chambers (OTCs) are commonly used to evaluate the effect of CO{sub 2},O{sub 3}, and other trace gases on vegetation. This study developed and tested a new technique for measuring forced air flow and net CO{sub 2} flux from OTCs. Experiments were performed with a 4.5-m diam. OTC with a sealed floor and a specialized air delivery system. Air flow through the chamber was computed with the Bernoulli equation using measurements of the pressure differential between the air delivery ducts and the chamber interior. An independent measurement of air flow was made simultaneously to calibrate and verify the accuracy of the Bernoulli relationship. The CO{sub 2} flux density was calculated as the product of chamber air flow and the difference in CO{sub 2} concentration between the air entering and exhausting from the OTC (C{sub in}-C{sub out}). Accuracy was evaluated by releasing CO{sub 2} within the OTC at known rates. Data were collected with OTCs at ambient and elevated CO{sub 2} ({approx}700 {mu}mol{sup -1}). Results showed the Bernoulli equation, with a flow coefficient of 0.7, accurately measured air flow in the OTC within {+-}5% regardless of flow rate and air duct geometry. Experiments in ambient OTCs showed CO{sub 2} flux density ({mu}mol m{sup -2} s{sup -1}), computed from 2-min averages of air flow and C{sub in} - C{sub out,} was typically within {+-} 10% of actual flux, provided that the exit air velocity at the top of the OTC was greater than 0.6 m s{sup -1}. Obtaining the same accuracy in CO{sub 2}-enriched OTCs required a critical exit velocity near 1.2 m s{sup -1} to minimize the incursion of ambient air and prevent contamination of exit gas sample. When flux data were integrated over time to estimate daily CO{sub 2} flux ({mu}mol m{sup -2} d{sup -1}), actual and measured values agreed to within {+-}2% for both ambient and CO{sub 2}-enriched chambers, suggesting that accurate measurements of daily net C exchange are possible with this technique.

  16. Carbon dioxide and climate

    SciTech Connect

    Not Available

    1990-10-01

    Scientific and public interest in greenhouse gases, climate warming, and global change virtually exploded in 1988. The Department's focused research on atmospheric CO{sub 2} contributed sound and timely scientific information to the many questions produced by the groundswell of interest and concern. Research projects summarized in this document provided the data base that made timely responses possible, and the contributions from participating scientists are genuinely appreciated. In the past year, the core CO{sub 2} research has continued to improve the scientific knowledge needed to project future atmospheric CO{sub 2} concentrations, to estimate climate sensitivity, and to assess the responses of vegetation to rising concentrations of CO{sub 2} and to climate change. The Carbon Dioxide Research Program's goal is to develop sound scientific information for policy formulation and governmental action in response to changes of atmospheric CO{sub 2}. The Program Summary describes projects funded by the Carbon Dioxide Research Program during FY 1990 and gives a brief overview of objectives, organization, and accomplishments.

  17. Incident shock-wave characteristics in air, argon, carbon dioxide, and helium in a shock tube with unheated helium driver

    NASA Technical Reports Server (NTRS)

    Miller, C. G., III; Jones, J. J.

    1975-01-01

    Incident shock-wave velocities were measured in the Langley 6-inch expansion tube, operated as a shock tube, with air, argon, carbon dioxide, and helium as test gases. Unheated helium was used as the driver gas and most data were obtained at pressures of approximately 34 and 54 MN/sq m. A range of pressure ratio across the diaphragm was obtained by varying the quiescent test-gas pressure, for a given driver pressure, from 0.0276 to 34.5 kN/sq m. Single- and double-diaphragm modes of operation were employed and diaphragms of various materials tested. Shock velocity was determined from microwave interferometer measurements, response of pressure transducers positioned along interferometer measurements, response of pressure transducers positioned along the driven section (time-of-arrival gages), and to a lesser extent, measured tube-wall pressure. Velocities obtained from these methods are compared and limitations of the methods discussed. The present results are compared with theory and the effects of diaphragm mode (single or double diaphragm), diaphragm material, heating of the driver gas upon pressurization of the driver section, diaphragm opening time, interface mixing, and two-dimensional (nonplanar) flow are discussed.

  18. Dynamics of carbon dioxide concentrations in the air and its effect on the cognitive ability of school students

    NASA Astrophysics Data System (ADS)

    Sidorin, D. I.

    2015-12-01

    The carbon dioxide (CO2) production intensity by a secondary school student is studied using a nondispersive infrared CO2 logger for different conditions: relaxation, mental stress, and physical stress. CO2 production measured for mental stress is 24% higher than that for relaxation, while CO2 production for physical stress is more than 2.5 times higher than relaxation levels. Dynamics of CO2 concentration in the classroom air is measured for a typical school building. It is shown that even when the classroom is ventilated between classes, CO2 concentration exceeds 2100 parts per million (ppm), which is significantly higher than the recommended limits defined in developed countries. The ability of seventh-grade school students to perform tasks requiring mental concentration is tested under different CO2 concentration conditions (below 1000 ppm and above 2000 ppm). Five-letter word anagrams are used as test tasks. Statistical analysis of the test results revealed a significant reduction in the number of provided correct answers and an increase in the number of errors when CO2 levels exceeded 2000 ppm.

  19. Carbon dioxide/dewpoint monitor

    NASA Technical Reports Server (NTRS)

    Luczkowski, S.

    1977-01-01

    The portable Carbon Dioxide/Dewpoint Monitor was designed to permit measurements of carbon dioxide partial pressure and dewpoint and ambient gas temperature at any place within the Saturn Workshop. It required no vehicle interface other than storage. All components necessary for operation, including battery power source, were incorporated in the instrument.

  20. Coral reefs and carbon dioxide

    SciTech Connect

    Buddemeier, R.W.

    1996-03-01

    This commentary argues the conclusion from a previous article, which investigates diurnal changes in carbon dioxide partial pressure and community metabolism on coral reefs, that coral `reefs might serve as a sink, not a source, for atmospheric carbon dioxide.` Commentaries from two groups are given along with the response by the original authors, Kayanne et al. 27 refs.

  1. Carbon Dioxide and Ionic Liquid Refrigerants: Compact, Efficient Air Conditioning with Ionic Liquid-Based Refrigerants

    SciTech Connect

    2010-10-01

    BEETIT Project: Notre Dame is developing an air-conditioning system with a new ionic liquid and CO2 as the working fluid. Synthetic refrigerants used in air conditioning and refrigeration systems are potent GHGs and can trap 1,000 times more heat in the atmosphere than CO2 alone—making CO2 an attractive alternative for synthetic refrigerants in cooling systems. However, operating cooling systems with pure CO2 requires prohibitively high pressures and expensive hardware. Notre Dame is creating a new fluid made of CO2 and ionic liquid that enables the use of CO2 at low pressures and requires minimal changes to existing hardware and production lines. This new fluid also produces no harmful emissions and can improve the efficiency of air conditioning systems— enabling new use of CO2 as a refrigerant in cooling systems.

  2. Continuous multichannel monitoring of cave air carbon dioxide using a pumped non-dispersive infrared analyser

    NASA Astrophysics Data System (ADS)

    Mattey, D.

    2012-04-01

    The concentration of CO2 in cave air is one of the main controls on the rate of degassing of dripwater and on the kinetics of calcite precipitation forming speleothem deposits. Measurements of cave air CO2reveal great complexity in the spatial distribution among interconnected cave chambers and temporal changes on synoptic to seasonal time scales. The rock of Gibraltar hosts a large number of caves distributed over a 300 meter range in altitude and monthly sampling and analysis of air and water combined with continuous logging of temperature, humidity and drip discharge rates since 2004 reveals the importance of density-driven seasonal ventilation which drives large-scale advection of CO2-rich air though the cave systems. Since 2008 we have deployed automatic CO2 monitoring systems that regularly sample cave air from up to 8 locations distributed laterally and vertically in St Michaels Cave located near the top of the rock at 275m asl and Ragged Staff Cave located in the heart of the rock near sea level. The logging system is controlled by a Campbell Scientific CR1000 programmable datalogger which controls an 8 port manifold connected to sampling lines leading to different parts of the cave over a distance of up to 250 meters. The manifold is pumped at a rate of 5l per minute drawing air through 6mm or 8mm id polythene tubing via a 1m Nafion loop to reduce humidity to local ambient conditions. The outlet of the primary pump leads to an open split which is sampled by a second low flow pump which delivers air at 100ml/minute to a Licor 820 CO2 analyser. The software selects the port to be sampled, flushes the line for 2 minutes and CO2 analysed as a set of 5 measurements averaged over 10 second intervals. The system then switches to the next port and when complete shuts down to conserve power after using 20 watts over a 30 minute period of analysis. In the absence of local mains power (eg from the show cave lighting system) two 12v car batteries will power the system

  3. Marine Technician's Handbook, Instructions for Taking Air Samples on Board Ship: Carbon Dioxide Project.

    ERIC Educational Resources Information Center

    Keeling, Charles D.

    This booklet is one of a series intended to provide explicit instructions for the collection of oceanographic data and samples at sea. The methods and procedures described have been used by the Scripps Institution of Oceanography and found reliable and up-to-date. Instructions are given for taking air samples on board ship to determine the…

  4. Comparison between air and carbon dioxide insufflation in the endoscopic submucosal excavation of gastrointestinal stromal tumors

    PubMed Central

    Shi, Wei-Bin; Wang, Zi-Hao; Qu, Chun-Ying; Zhang, Yi; Jiang, Han; Zhou, Min; Chen, Ying; Xu, Lei-Ming

    2012-01-01

    AIM: To evaluate the safety and efficacy of CO2 insufflation compared with air insufflation in the endoscopic submucosal excavation (ESE) of gastrointestinal stromal tumors. METHODS: Sixty patients were randomized to undergo endoscopic submucosal excavation, with the CO2 group (n = 30) and the air group (n = 30) undergoing CO2 insufflation and air insufflation in the ESE, respectively. The end-tidal CO2 level (pETCO2) was observed at 4 time points: at the beginning of ESE, at total removal of the tumors, at completed wound management, and 10 min after ESE. Additionally, the patients’ experience of pain at 1, 3, 6 and 24 h after the examination was registered using a visual analog scale (VAS). RESULTS: Both the CO2 group and air group were similar in mean age, sex, body mass index (all P > 0.05). There were no significant differences in PetCO2 values before and after the procedure (P > 0.05). However, the pain scores after the ESE at different time points in the CO2 group decreased significantly compared with the air group (1 h: 21.2 ± 3.4 vs 61.5 ± 1.7; 3 h: 8.5 ± 0.7 vs 42.9 ± 1.3; 6 h: 4.4 ± 1.6 vs 27.6 ± 1.2; 24 h: 2.3 ± 0.4 vs 21.4 ± 0.7, P < 0.05). Meanwhile, the percentage of VAS scores of 0 in the CO2 group after 1, 3, 6 and 24 h was significantly higher than that in the air group (60.7 ± 1.4 vs 18.9 ± 1.5, 81.5 ± 2.3 vs 20.6 ± 1.2, 89.2 ± 0.7 vs 36.8 ± 0.9, 91.3 ± 0.8 vs 63.8 ± 1.3, respectively, P < 0.05). Moreover, the condition of the CO2 group was better than that of the air group with respect to anal exsufflation. CONCLUSION: Insufflation of CO2 in the ESE of gastrointestinal stromal tumors will not cause CO2 retention and it may significantly reduce the level of pain, thus it is safe and effective. PMID:23326136

  5. Three years of greenhouse gas column-averaged dry air mole fractions retrieved from satellite Part 1: Carbon dioxide

    NASA Astrophysics Data System (ADS)

    Schneising, O.; Buchwitz, M.; Burrows, J. P.; Bovensmann, H.; Reuter, M.; Notholt, J.; Macatangay, R.; Warneke, T.

    2008-07-01

    Carbon dioxide (CO2) and methane (CH4) are the two most important anthropogenic greenhouse gases. SCIAMACHY on ENVISAT is the first satellite instrument whose measurements are sensitive to concentration changes of the two gases at all altitude levels down to the Earth's surface where the source/sink signals are largest. We have processed three years (2003 2005) of SCIAMACHY near-infrared nadir measurements to simultaneously retrieve vertical columns of CO2 (from the 1.58 μm absorption band), CH4 (1.66 μm) and oxygen (O2 A-band at 0.76 μm) using the scientific retrieval algorithm WFM-DOAS. We show that the latest version of WFM-DOAS, version 1.0, which is used for this study, has been significantly improved with respect to its accuracy compared to the previous versions while essentially maintaining its high processing speed (~1 min per orbit, corresponding to ~6000 single measurements, and per gas on a standard PC). The greenhouse gas columns are converted to dry air column-averaged mole fractions, denoted XCO2 (in ppm) and XCH4 (in ppb), by dividing the greenhouse gas columns by simultaneously retrieved dry air columns. For XCO2 dry air columns are obtained from the retrieved O2 columns. For XCH4 dry air columns are obtained from the retrieved CO2 columns because of better cancellation of light path related errors compared to using O2 columns retrieved from the spectrally distant O2 A-band. Here we focus on a discussion of the XCO2 data set. The XCH4 data set is discussed in a separate paper (Part 2). In order to assess the quality of the retrieved XCO2 we present comparisons with Fourier Transform Spectroscopy (FTS) XCO2 measurements at two northern hemispheric mid-latitude ground stations. To assess the quality globally, we present detailed comparisons with global XCO2 fields obtained from NOAA's CO2 assimilation system CarbonTracker. For the Northern Hemisphere we find good agreement with the reference data for the CO2 seasonal cycle and the CO2 annual

  6. Ballistic Range Measurements of Stagnation-Point Heat Transfer in Air and in Carbon Dioxide at Velocities up to 18,000 Feet Per Second

    NASA Technical Reports Server (NTRS)

    Yee, Layton; Bailey, Harry E.; Woodward, Henry T.

    1961-01-01

    A new technique for measuring heat-transfer rates on free-flight models in a ballistic range is described in this report. The accuracy of the heat-transfer rates measured in this way is shown to be comparable with the accuracy obtained in shock-tube measurements. The specific results of the present experiments consist of measurements of the stagnation-point heat-transfer rates experienced by a spherical-nosed model during flight through air and through carbon dioxide at velocities up to 18,000 feet per second. For flight through air these measured heat-transfer rates agree well with both the theoretically predicted rates and the rates measured in shock tubes. the heat-transfer rates agree well with the rates measured in a shock tube. Two methods of estimating the stagnation-point heat-transfer rates in carbon dioxide are compared with the experimental measurements. At each velocity the measured stagnation-point heat-transfer rate in carbon dioxide is about the same as the measured heat-transfer rate in air.

  7. Penetration Characteristics of Air, Carbon Dioxide and Helium Transverse Sonic Jets in Mach 5 Cross Flow

    PubMed Central

    Erdem, Erinc; Kontis, Konstantinos; Saravanan, Selvaraj

    2014-01-01

    An experimental investigation of sonic air, CO2 and Helium transverse jets in Mach 5 cross flow was carried out over a flat plate. The jet to freestream momentum flux ratio, J, was kept the same for all gases. The unsteady flow topology was examined using high speed schlieren visualisation and PIV. Schlieren visualisation provided information regarding oscillating jet shear layer structures and bow shock, Mach disc and barrel shocks. Two-component PIV measurements at the centreline, provided information regarding jet penetration trajectories. Barrel shocks and Mach disc forming the jet boundary were visualised/quantified also jet penetration boundaries were determined. Even though J is kept the same for all gases, the penetration patterns were found to be remarkably different both at the nearfield and the farfield. Air and CO2 jet resulted similar nearfield and farfield penetration pattern whereas Helium jet spread minimal in the nearfield. PMID:25494348

  8. Carbon Dioxide Landscape

    NASA Technical Reports Server (NTRS)

    2004-01-01

    7 July 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a mid-summer view of the south polar residual cap at full MOC resolution, 1.5 m (5 ft) per pixel. During each of the three summers since the start of the MGS mapping mission in March 1999, the scarps that form mesas and pits in the 'Swiss cheese'-like south polar terrain have retreated an average of about 3 meters (1 yard). The material is frozen carbon dioxide; another 3 meters or so of each scarp is expected to be removed during the next summer, in late 2005. This image is located near 86.0oS, 350.8oW, and covers an area about 1.5 km (0.9 mi) wide. Sunlight illuminates the scene from the top/upper left.

  9. Forecasting carbon dioxide emissions.

    PubMed

    Zhao, Xiaobing; Du, Ding

    2015-09-01

    This study extends the literature on forecasting carbon dioxide (CO2) emissions by applying the reduced-form econometrics approach of Schmalensee et al. (1998) to a more recent sample period, the post-1997 period. Using the post-1997 period is motivated by the observation that the strengthening pace of global climate policy may have been accelerated since 1997. Based on our parameter estimates, we project 25% reduction in CO2 emissions by 2050 according to an economic and population growth scenario that is more consistent with recent global trends. Our forecasts are conservative due to that we do not have sufficient data to fully take into account recent developments in the global economy. PMID:26081307

  10. Carbon dioxide: atmospheric overload

    SciTech Connect

    Not Available

    1980-04-01

    The level of carbon dioxide in the atmosphere is increasing and may double within the next century. The result of this phenomenon, climatic alterations, will adversely affect crop production, water supplies, and global temperatures. Sources of CO2 include the combustion of fossil fuels, photosynthesis, and the decay of organic matter in soils. The most serious effect of possible climatic changes could occur along the boundaries of arid and semiarid regions. Shifts is precipitation patterns could accelerate the processes of desertification. An increase of 5..cap alpha..C in the average temperature of the top 1000 m of ocean water would raise sea level by 2 m. CO2 releases to the atmosphere can be reduced by controlling emissions from fossil fuel-fired facilities and by careful harvesting of forest regions. (3 photos, 5 references)

  11. Measurements of concentrations of chlorofluoromethanes (CFMs) carbon dioxide and carbon isotope ratio in stratospheric and tropospheric air by grab-sampling systems

    NASA Technical Reports Server (NTRS)

    Itoh, T.; Kubo, H.; Honda, H.; Tominaga, T.; Makide, Y.; Yakohata, A.; Sakai, H.

    1985-01-01

    Measurements of concentrations of chlorofluoromethanes (CFMs), carbon dioxide and carbon isotope ratio in stratospheric and tropospheric air by grab-sampling systems are reported. The balloon-borne grab-sampling system has been launched from Sanriku Balloon Center three times since 1981. It consists of: (1) six sampling cylinders, (2) eight motor driven values, (3) control and monitor circuits, and (4) pressurized housing. Particular consideration is paid to the problem of contamination. Strict requirements are placed on the choice of materials and components, construction methods, cleaning techniques, vacuum integrity, and sampling procedures. An aluminum pressurized housing and a 4-m long inlet line are employed to prevent the sampling air from contamination by outgassing of sampling and control devices. The sampling is performed during the descent of the system. Vertical profiles of mixing ratios of CF2Cl2, CFCl3 and CH4 are given. Mixing ratios of CF2Cl2 and CFCl3 in the stratosphere do not show the discernible effect of the increase of those in the ground level background, and decrease with altitude. Decreasing rate of CFCl3 is larger than that of CF2Cl2. CH4 mixing ratio, on the other hand, shows diffusive equilibrium, as the photodissociation cross section of CH4 is small and concentrations of OH radical and 0(sup I D) are low.

  12. Sea-air carbon dioxide fluxes along 35°S in the South Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Lencina-Avila, J. M.; Ito, R. G.; Garcia, C. A. E.; Tavano, V. M.

    2016-09-01

    The oceans play an important role in absorbing a significant fraction of the atmospheric CO2 surplus, but there are still uncertainties concerning several open ocean regions, such as the under-sampled South Atlantic Ocean. This study assessed the net sea-air CO2 fluxes and distribution of sea-surface CO2 fugacity (f C O2sw) along the 35°S latitude in the South Atlantic, during 2011 spring and early summer periods. Underway CO2 molar fraction, temperature, salinity and dissolved oxygen measurements were taken continuously from South American to South African continental shelves. Values of both satellite and discrete in situ chlorophyll-a concentration along the ship's track were used as ancillary data. Both f C O2sw and difference in sea-air fugacity (ΔfCO2) showed high variability along the cruise track, with higher values found on the continental shelf and slope regions. All ΔfCO2 values were negative, implying that a sinking process was occurring during the cruise period, with an average net CO2 flux of -3.1±2.2 mmol CO2 m-2 day-1 (using Wanninkhof, 1992). Physical variables were the main drivers of f C O2sw variability in South American continental shelf and open ocean regions, while the biological factor dominated the South African continental shelf. Algorithms for estimating fCO2 and temperature-normalized fCO2 were developed and applied separately to the three defined sub-regions: the South American shelf, the open ocean and the South African continental shelf, with the regional temperature-normalized fCO2 models showing better results.

  13. Free-air carbon dioxide enrichment of cotton: Root morphological characteristics

    SciTech Connect

    Prior, S.A.; Royers, H.H.; Runion, G.B.

    1995-07-01

    The response of plants to rising global CO{sub 2} concentration is of critical research interest but one neglected aspect is its effect on roots. Root morphological changes in cotton [Gossypium hirsutum (L.)`Delta Pine 77`] were examined in a 2-yr field study. The test crop was grown under two water regimes (wet, 100% of evapotranspiration [ET] replaced and dry, 75% [1990] and 67% [1991] of ET replaced) and two atmospheric CO{sub 2} concentrations (ambient = 370 {mu}mol mol{sup -1} and free-air CO{sub 2} enrichment [FACE] = 550 {mu}mol mol{sup -1}). A FACE technique that allows for CO{sub 2} exposure under field conditions with minimal alteration of plant microclimate was used. Excavated root systems were partitioned into taproot and lateral roots at two growth phases (vegetative and reproductive) Vertical root-pulling resistance was determined at the second sampling; this measure was higher because of CO{sub 2} enrichment but was unaffected by water stress. Water stress affected root variables only at the second sampling; water stress reduced taproot variables more than lateral variables. The larger diameter taproots seen at all sample dates under FACE exhibited large increases in dry weight and volume. FACE often increased lateral root number and lateral dry weights were higher at all sample dates. The development of more robust taproot systems in CO{sub 2}-enriched environments may allow for greater carbohydrate storage for utilization during periods such as boll filling and to ensure root growth for continued exploration of the soil profile to meet nutrient and water demands during peak demand periods. 32 refs., 2 figs., 2 tabs.

  14. Short communication: Effects of dairy calf hutch elevation on heat reduction, carbon dioxide concentration, air circulation, and respiratory rates.

    PubMed

    Moore, D A; Duprau, J L; Wenz, J R

    2012-07-01

    Heat stress affects dairy calf welfare and can result in morbidity, mortality, and lower weight gain. The purpose of this project was to evaluate the effects of elevating the back of plastic calf hutches on measures of ventilation and heat stress. A total of 15 calves housed in individual hutches were enrolled, with each calf hutch serving as its own control. Heat, humidity, carbon dioxide, and wind speed were measured inside each hutch and the observations were compared with external measurements over two 24-h periods; 1 period without and 1 with hutch elevation. Respiratory rates were measured in the morning and afternoon as an indicator of the degree of heat stress experienced by calves with and without elevation of the hutch. When the hutch was elevated, internal hutch temperatures were cooler than external temperatures, hutch carbon dioxide levels were lower and respiratory rates were lower, particularly comparing the afternoon observation periods. PMID:22720960

  15. Sea surface carbon dioxide at the Georgia time series site (2006-2007): Air-sea flux and controlling processes

    NASA Astrophysics Data System (ADS)

    Xue, Liang; Cai, Wei-Jun; Hu, Xinping; Sabine, Christopher; Jones, Stacy; Sutton, Adrienne J.; Jiang, Li-Qing; Reimer, Janet J.

    2016-01-01

    Carbon dioxide partial pressure (pCO2) in surface seawater was continuously recorded every three hours from 18 July 2006 through 31 October 2007 using a moored autonomous pCO2 (MAPCO2) system deployed on the Gray's Reef buoy off the coast of Georgia, USA. Surface water pCO2 (average 373 ± 52 μatm) showed a clear seasonal pattern, undersaturated with respect to the atmosphere in cold months and generally oversaturated in warm months. High temporal resolution observations revealed important events not captured in previous ship-based observations, such as sporadically occurring biological CO2 uptake during April-June 2007. In addition to a qualitative analysis of the primary drivers of pCO2 variability based on property regressions, we quantified contributions of temperature, air-sea exchange, mixing, and biological processes to monthly pCO2 variations using a 1-D mass budget model. Although temperature played a dominant role in the annual cycle of pCO2, river inputs especially in the wet season, biological respiration in peak summer, and biological production during April-June 2007 also substantially influenced seawater pCO2. Furthermore, sea surface pCO2 was higher in September-October 2007 than in September-October 2006, associated with increased river inputs in fall 2007. On an annual basis this site was a moderate atmospheric CO2 sink, and was autotrophic as revealed by monthly mean net community production (NCP) in the mixed layer. If the sporadic short productive events during April-May 2007 were missed by the sampling schedule, one would conclude erroneously that the site is heterotrophic. While previous ship-based pCO2 data collected around this buoy site agreed with the buoy CO2 data on seasonal scales, high resolution buoy observations revealed that the cruise-based surveys undersampled temporal variability in coastal waters, which could greatly bias the estimates of air-sea CO2 fluxes or annual NCP, and even produce contradictory results.

  16. Reducing carbon dioxide to products

    SciTech Connect

    Cole, Emily Barton; Sivasankar, Narayanappa; Parajuli, Rishi; Keets, Kate A

    2014-09-30

    A method reducing carbon dioxide to one or more products may include steps (A) to (C). Step (A) may bubble said carbon dioxide into a solution of an electrolyte and a catalyst in a divided electrochemical cell. The divided electrochemical cell may include an anode in a first cell compartment and a cathode in a second cell compartment. The cathode may reduce said carbon dioxide into said products. Step (B) may adjust one or more of (a) a cathode material, (b) a surface morphology of said cathode, (c) said electrolyte, (d) a manner in which said carbon dioxide is bubbled, (e), a pH level of said solution, and (f) an electrical potential of said divided electrochemical cell, to vary at least one of (i) which of said products is produced and (ii) a faradaic yield of said products. Step (C) may separate said products from said solution.

  17. Recuperative supercritical carbon dioxide cycle

    SciTech Connect

    Sonwane, Chandrashekhar; Sprouse, Kenneth M; Subbaraman, Ganesan; O'Connor, George M; Johnson, Gregory A

    2014-11-18

    A power plant includes a closed loop, supercritical carbon dioxide system (CLS-CO.sub.2 system). The CLS-CO.sub.2 system includes a turbine-generator and a high temperature recuperator (HTR) that is arranged to receive expanded carbon dioxide from the turbine-generator. The HTR includes a plurality of heat exchangers that define respective heat exchange areas. At least two of the heat exchangers have different heat exchange areas.

  18. Long-Duration Testing of a Temperature-Swing Adsorption Compressor for Carbon Dioxide for Closed-Loop Air Revitalization Systems

    NASA Technical Reports Server (NTRS)

    Rosen, Micha; Mulloth, Lila; Varghese, Mini

    2005-01-01

    This paper describes the results of long-duration testing of a temperature-swing adsorption compressor that has application in the International Space Station (ISS) and future spacecraft for closing the air revitalization loop. The air revitalization system of the ISS operates in an open loop mode and relies on the resupply of oxygen and other consumables from Earth for the life support of astronauts. A compressor is required for delivering the carbon dioxide from a removal assembly to a reduction unit to recover oxygen and thereby closing the air-loop. The TSAC is a solid-state compressor that has the capability to remove CO2 from a low-pressure source, and subsequently store, compress, and deliver at a higher pressure as required by a processor. The TSAC is an ideal interface device for CO2 removal and reduction units in the air revitalization loop of a spacecraft for oxygen recovery. The TSAC was developed and its operation was successfully verified in integration tests with the flight-like Carbon Dioxide Removal Assembly (CDRA) at Marshall Space Flight Center prior to the long-duration tests. Long-duration tests reveal the impacts of repeated thermal cycling on the compressor components and the adsorbent material.

  19. Magnesite disposal of carbon dioxide

    SciTech Connect

    Lackner, K.S.; Butt, D.P.; Wendt, C.H.

    1997-08-01

    In this paper we report our progress on developing a method for carbon dioxide disposal whose purpose it is to maintain coal energy competitive even is environmental and political pressures will require a drastic reduction in carbon dioxide emissions. In contrast to most other methods, our approach is not aiming at a partial solution of the problem, or at buying time for phasing out fossil energy. Instead, its purpose is to obtain a complete and economic solution of the problem, and thus maintain access to the vast fossil energy reservoir. A successful development of this technology would guarantee energy availability for many centuries even if world economic growth the most optimistic estimates that have been put forward. Our approach differs from all others in that we are developing an industrial process which chemically binds the carbon dioxide in an exothermic reaction into a mineral carbonate that is thermodynamically stable and environmentally benign.

  20. Net carbon dioxide exchange rates and predicted growth patterns in Alstroemeria Jacqueline' at varying irradiances, carbon dioxide concentrations, and air temperatures

    SciTech Connect

    Leonardos, E.D.; Tsujita, M.J.; Grodzinski, B. . Dept. of Horticultural Science)

    1994-11-01

    The influence of irradiance, CO[sub 2] concentration, and air temperature on leaf and whole-plant net C exchange rate (NCER) of Alstroemeria Jacqueline' was studied. At ambient CO[sub 2], leaf net photosynthesis was maximum at irradiances above 600 [mu]mol[center dot]m[sup [minus]2][center dot]s[sup [minus]1] photosynthetically active radiation (PAR), while whole-plant NCER required 1,200 [mu]mol[center dot]m[sup [minus]2][center dot]s[sup [minus]1] PAR to be saturated. Leaf and whole-plant NCERs were doubled under CO[sub 2] enrichment of 1,500 to 2,000 [mu]l CO[sub 2]/liter. Leaf and whole-plant NCERs declined as temperature increased from 20 to 35 C. Whereas the optimum temperature range for leaf net photosynthesis was 17 to 23 C, whole-plant NCER, even at high light and high CO[sub 2], declined above 12 C. Dark respiration of leaves and whole plants increased with a Q[sub 10] of [approx] 2 at 15 to 35 C. In an analysis of day effects, irradiance, CO[sub 2] concentration, and temperature contributed 58%, 23%, and 14%, respectively, to the total variation in NCER explained by a second-order polynomial model (R[sup 2] = 0.85). Interactions among the factors accounted for 4% of the variation in day C assimilation. The potential whole-plant growth rates during varying greenhouse day and night temperature regimes were predicted for short- and long-day scenarios. The data are discussed with the view of designing experiments to test the importance of C gain in supporting flowering and high yield during routine harvest of Alstroemeria plants under commercial greenhouse conditions.

  1. Carbon Dioxide - Our Common "Enemy"

    NASA Technical Reports Server (NTRS)

    James, John T.; Macatangay, Ariel

    2009-01-01

    Health effects of brief and prolonged exposure to carbon dioxide continue to be a concern for those of us who manage this pollutant in closed volumes, such as in spacecraft and submarines. In both examples, considerable resources are required to scrub the atmosphere to levels that are considered totally safe for maintenance of crew health and performance. Defining safe levels is not a simple task because of many confounding factors, including: lack of a robust database on human exposures, suspected significant variations in individual susceptibility, variations in the endpoints used to assess potentially adverse effects, the added effects of stress, and the fluid shifts associated with micro-gravity (astronauts only). In 2007 the National Research Council proposed revised Continuous Exposure Guidelines (CEGLs) and Emergency Exposure Guidelines (EEGLs) to the U.S. Navy. Similarly, in 2008 the NASA Toxicology Group, in cooperation with another subcommittee of the National Research Council, revised Spacecraft Maximum Allowable Concentrations (SMACs). In addition, a 1000-day exposure limit was set for long-duration spaceflights to celestial bodies. Herein we examine the rationale for the levels proposed to the U.S. Navy and compare this rationale with the one used by NASA to set its limits. We include a critical review of previous studies on the effects of exposure to carbon dioxide and attempt to dissect out the challenges associated with setting fully-defensible limits. We also describe recent experiences with management of carbon dioxide aboard the International Space Station with 13 persons aboard. This includes the tandem operations of the Russian Vozduk and the U.S. Carbon Dioxide Removal System. A third removal system is present while the station is docked to the Shuttle spacecraft, so our experience includes the lithium hydroxide system aboard Shuttle for the removal of carbon dioxide. We discuss strategies for highly-efficient, regenerable removal of carbon

  2. Plants Can't Do without Carbon Dioxide.

    ERIC Educational Resources Information Center

    Hershey, David R.

    1992-01-01

    Describes an experiment to induce carbon dioxide deficiency to demonstrate its effects on plant growth. Suggests further studies to examine respiration by soil microbes and the effects of relative humidity, other gases, and air pollution on plant growth. (MDH)

  3. Carbon Dioxide Absorption Heat Pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    2002-01-01

    A carbon dioxide absorption heat pump cycle is disclosed using a high pressure stage and a super-critical cooling stage to provide a non-toxic system. Using carbon dioxide gas as the working fluid in the system, the present invention desorbs the CO2 from an absorbent and cools the gas in the super-critical state to deliver heat thereby. The cooled CO2 gas is then expanded thereby providing cooling and is returned to an absorber for further cycling. Strategic use of heat exchangers can increase the efficiency and performance of the system.

  4. Large Scale Variability of Mid-Tropospheric Carbon Dioxide as Observed by the Atmospheric Infrared Sounder (AIRS) on the NASA EOS Aqua Platform

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Olsen, Edward T.

    2012-01-01

    The Atmospheric Infrared Sounder (AIRS) is a hyperspectral infrared instrument on the EOS Aqua Spacecraft, launched on May 4, 2002. AIRS has 2378 infrared channels ranging from 3.7 microns to 15.4 microns and a 13.5 km footprint. AIRS, in conjunction with the Advanced Microwave Sounding Unit (AMSU), produces temperature profiles with 1K/km accuracy, water vapor profiles (20%/2km), infrared cloud height and fraction, and trace gas amounts for CO2, CO, SO2, O3 and CH4 in the mid to upper troposphere. AIRS wide swath(cedilla) +/-49.5 deg , enables daily global daily coverage for over 95% of the Earth's surface. AIRS data are used for weather forecasting, validating climate model distribution and processes, and observing long-range transport of greenhouse gases. In this study, we examine the large scale and regional horizontal variability in the AIRS Mid-tropospheric Carbon Dioxide product as a function of season and associate the observed variability with known atmospheric transport processes, and sources and sinks of CO2.

  5. Process for sequestering carbon dioxide and sulfur dioxide

    DOEpatents

    Maroto-Valer, M. Mercedes; Zhang, Yinzhi; Kuchta, Matthew E.; Andresen, John M.; Fauth, Dan J.

    2009-10-20

    A process for sequestering carbon dioxide, which includes reacting a silicate based material with an acid to form a suspension, and combining the suspension with carbon dioxide to create active carbonation of the silicate-based material, and thereafter producing a metal salt, silica and regenerating the acid in the liquid phase of the suspension.

  6. High capacity carbon dioxide sorbent

    SciTech Connect

    Dietz, Steven Dean; Alptekin, Gokhan; Jayaraman, Ambalavanan

    2015-09-01

    The present invention provides a sorbent for the removal of carbon dioxide from gas streams, comprising: a CO.sub.2 capacity of at least 9 weight percent when measured at 22.degree. C. and 1 atmosphere; an H.sub.2O capacity of at most 15 weight percent when measured at 25.degree. C. and 1 atmosphere; and an isosteric heat of adsorption of from 5 to 8.5 kilocalories per mole of CO.sub.2. The invention also provides a carbon sorbent in a powder, a granular or a pellet form for the removal of carbon dioxide from gas streams, comprising: a carbon content of at least 90 weight percent; a nitrogen content of at least 1 weight percent; an oxygen content of at most 3 weight percent; a BET surface area from 50 to 2600 m.sup.2/g; and a DFT micropore volume from 0.04 to 0.8 cc/g.

  7. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and....1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No. 124-38-9) occurs as a..., sublimes under atmospheric pressure at a temperature of −78.5 °C. Carbon dioxide is prepared as a...

  8. Carbon dioxide transport over complex terrain

    USGS Publications Warehouse

    Sun, Jielun; Burns, Sean P.; Delany, A.C.; Oncley, S.P.; Turnipseed, A.; Stephens, B.; Guenther, A.; Anderson, D.E.; Monson, R.

    2004-01-01

    The nocturnal transport of carbon dioxide over complex terrain was investigated. The high carbon dioxide under very stable conditions flows to local low-ground. The regional drainage flow dominates the carbon dioxide transport at the 6 m above the ground and carbon dioxide was transported to the regional low ground. The results show that the local drainage flow was sensitive to turbulent mixing associated with local wind shear.

  9. Modelling Sublimation of Carbon Dioxide

    ERIC Educational Resources Information Center

    Winkel, Brian

    2012-01-01

    In this article, the author reports results in their efforts to model sublimation of carbon dioxide and the associated kinetics order and parameter estimation issues in their model. They have offered the reader two sets of data and several approaches to determine the rate of sublimation of a piece of solid dry ice. They presented several models…

  10. 21 CFR 582.1240 - Carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  11. 21 CFR 582.1240 - Carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  12. 21 CFR 582.1240 - Carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  13. 21 CFR 582.1240 - Carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  14. 21 CFR 582.1240 - Carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  15. Application of a high-efficiency cabin air filter for simultaneous mitigation of ultrafine particle and carbon dioxide exposures inside passenger vehicles.

    PubMed

    Lee, Eon S; Zhu, Yifang

    2014-02-18

    Modern passenger vehicles are commonly equipped with cabin air filters but their filtration efficiency for ultrafine particle (UFP) is rather low. Although setting the vehicle ventilation system to recirculation (RC) mode can reduce in-cabin UFPs by ∼ 90%, passenger-exhaled carbon dioxide (CO2) can quickly accumulate inside the cabin. Using outdoor air (OA) mode instead can provide sufficient air exchange to prevent CO2 buildup, but in-cabin UFP concentrations would increase. To overcome this dilemma, we developed a simultaneous mitigation method for UFP and CO2 using high-efficiency cabin air (HECA) filtration in OA mode. Concentrations of UFP and other air pollutants were simultaneously monitored in and out of 12 different vehicles under 3 driving conditions: stationary, on local roadways, and on freeways. Under each experimental condition, data were collected with no filter, in-use original equipment manufacturer (OEM) filter, and two types of HECA filters. The HECA filters offered an average in-cabin UFP reduction of 93%, much higher than the OEM filters (∼ 50% on average). Throughout the measurements, the in-cabin CO2 concentration remained in the range of 620-930 ppm, significantly lower than the typical level of 2500-4000 ppm observed in the RC mode. PMID:24471775

  16. A miniature chemiresistor sensor for carbon dioxide.

    PubMed

    Srinives, Sira; Sarkar, Tapan; Hernandez, Raul; Mulchandani, Ashok

    2015-05-18

    A carpet-like nanostructure of polyaniline (PANI) nanothin film functionalized with poly(ethyleneimine), PEI, was used as a miniature chemiresistor sensor for detection of CO2 at room temperature. Good sensing performance was observed upon exposing the PEI-PANI device to 50-5000 ppm CO2 in presence of humidity with negligible interference from ammonia, carbon monoxide, methane and nitrogen dioxide. The sensing mechanism relied on acid-base reaction, CO2 dissolution and amine-catalyzed hydration that yielded carbamates and carbonic acid for a subsequent pH detection. The sensing device showed reliable results in detecting an unknown concentration of CO2 in air. PMID:25910446

  17. CARBON DIOXIDE AS A FEEDSTOCK.

    SciTech Connect

    CREUTZ,C.; FUJITA,E.

    2000-12-09

    This report is an overview on the subject of carbon dioxide as a starting material for organic syntheses of potential commercial interest and the utilization of carbon dioxide as a substrate for fuel production. It draws extensively on literature sources, particularly on the report of a 1999 Workshop on the subject of catalysis in carbon dioxide utilization, but with emphasis on systems of most interest to us. Atmospheric carbon dioxide is an abundant (750 billion tons in atmosphere), but dilute source of carbon (only 0.036 % by volume), so technologies for utilization at the production source are crucial for both sequestration and utilization. Sequestration--such as pumping CO{sub 2} into sea or the earth--is beyond the scope of this report, except where it overlaps utilization, for example in converting CO{sub 2} to polymers. But sequestration dominates current thinking on short term solutions to global warming, as should be clear from reports from this and other workshops. The 3500 million tons estimated to be added to the atmosphere annually at present can be compared to the 110 million tons used to produce chemicals, chiefly urea (75 million tons), salicylic acid, cyclic carbonates and polycarbonates. Increased utilization of CO{sub 2} as a starting material is, however, highly desirable, because it is an inexpensive, non-toxic starting material. There are ongoing efforts to replace phosgene as a starting material. Creation of new materials and markets for them will increase this utilization, producing an increasingly positive, albeit small impact on global CO{sub 2} levels. The other uses of interest are utilization as a solvent and for fuel production and these will be discussed in turn.

  18. Responses of cotton and wheat photosynthesis and growth to cyclic variation in carbon dioxide concentration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The carbon dioxide concentration in free air carbon dioxide enrichment systems (FACE) often has rapid fluctuations. In our FACE system, power spectral analysis of carbon dioxide concentrations measured every second with an open path analyzer indicated peaks in variation centered on a wavelength of ...

  19. Investigations of the spatial and temporal resolution of retrievals of atmospheric carbon dioxide from the Atmospheric InfraRed Sounder (AIRS).

    NASA Astrophysics Data System (ADS)

    Maddy, Eric Sean

    As the dominant anthropogenic greenhouse gas, carbon dioxide (CO 2), represents an important component of climate change (IPCC 2007). Owing to burning of fossil fuels and deforestation, atmospheric CO2 concentrations have increased over 110 parts-per-million by volume (ppmv) from 270 ppmv to 380 ppmv since the dawn of the Industrial Revolution. Understanding of the spatial distribution of the sources and sinks of atmospheric CO 2 is necessary not only to predict the future atmospheric abundances but also their effect on future climate. Although designed for deriving high precision temperature and moisture profiles, NASA's Atmospheric InfraRed Sounder (AIRS) IR measurements include broad vertical sensitivity (between 3 and 10 km) to atmospheric CO2 variations. Coupled with AIRS' broad swath pattern and a technique referred to as "cloud-clearing" these measurements enable daily global spatial coverage. Nevertheless, AIRS' ability to determine the spatial distribution of carbon dioxide (CO2) is strongly dependent on its ability to separate the radiative effects of CO2 from temperature not to mention measurement uncertainties due to clouds and other geophysical variables such as moisture and ozone. This research presents a thorough investigation into the temporal and spatial scales that the AIRS can separate temperature (and other geophysical variables) from CO2. Through our detailed understanding of the way satellites view the Earth's atmosphere, we have developed an algorithm capable of retrieving global middle-to-upper tropospheric CO2 concentrations in all-weather conditions with total uncertainties ranging between 1 to 2 ppmv. From a radiative perspective, roughly equivalent to 30 mK to 60 mK, 1 to 2 ppmv, is an awesome feat for a space-borne sensor. Necessary for the remarkable performance of this algorithm, we developed methodologies capable of separating the radiative effect of CO2 variability from temperature, improved the fast rapid transmittance algorithm

  20. Oxygen and carbon dioxide sensing

    NASA Technical Reports Server (NTRS)

    Ren, Fan (Inventor); Pearton, Stephen John (Inventor)

    2012-01-01

    A high electron mobility transistor (HEMT) capable of performing as a CO.sub.2 or O.sub.2 sensor is disclosed, hi one implementation, a polymer solar cell can be connected to the HEMT for use in an infrared detection system. In a second implementation, a selective recognition layer can be provided on a gate region of the HEMT. For carbon dioxide sensing, the selective recognition layer can be, in one example, PEI/starch. For oxygen sensing, the selective recognition layer can be, in one example, indium zinc oxide (IZO). In one application, the HEMTs can be used for the detection of carbon dioxide and oxygen in exhaled breath or blood.

  1. Method for carbon dioxide sequestration

    SciTech Connect

    Wang, Yifeng; Bryan, Charles R.; Dewers, Thomas; Heath, Jason E.

    2015-09-22

    A method for geo-sequestration of a carbon dioxide includes selection of a target water-laden geological formation with low-permeability interbeds, providing an injection well into the formation and injecting supercritical carbon dioxide (SC--CO.sub.2) into the injection well under conditions of temperature, pressure and density selected to cause the fluid to enter the formation and splinter and/or form immobilized ganglia within the formation. This process allows for the immobilization of the injected SC--CO.sub.2 for very long times. The dispersal of scCO2 into small ganglia is accomplished by alternating injection of SC--CO.sub.2 and water. The injection rate is required to be high enough to ensure the SC--CO.sub.2 at the advancing front to be broken into pieces and small enough for immobilization through viscous instability.

  2. Use of the electrosurgical unit in a carbon dioxide atmosphere.

    PubMed

    Culp, William C; Kimbrough, Bradly A; Luna, Sarah; Maguddayao, Aris J; Eidson, Jack L; Paolino, David V

    2016-01-01

    The electrosurgical unit (ESU) utilizes an electrical discharge to cut and coagulate tissue and is often held above the surgical site, causing a spark to form. The voltage at which the spark is created, termed the breakdown voltage, is governed by the surrounding gaseous environment. Surgeons are now utilizing the ESU laparoscopically with carbon dioxide insufflation, potentially altering ESU operating characteristics. This study examines the clinical implications of altering gas composition by measuring the spark gap distance as a marker of breakdown voltage and use of the ESU on a biologic model, both in room air and carbon dioxide. Paschen's Law predicted a 35% decrease in gap distance in carbon dioxide, while testing revealed an average drop of 37-47% as compared to air. However, surgical model testing revealed no perceivable clinical difference. Electrosurgery can be performed in carbon dioxide environments, although surgeons should be aware of potentially altered ESU performance. PMID:26745650

  3. Carbon dioxide review 1982

    SciTech Connect

    Clark, W.C.

    1982-01-01

    The buildup of CO/sub 2/ is a reality, monitored with increasing precision since 1957 and inferred for much earlier dates. A statistical section gives the monitored values to 1980, as well as a review of a long series of measurements made at Mauna Loa by the pioneers of such monitoring, Charles D. Keeling, Robert B. Bacastow, and Timothy P. Whorf. The book discusses internal transport processes in the ocean, of ocean-atmosphere interaction, of the magnitude of forest and soil carbon wastage, of the future course of fossil-fuel consumption. Yet something else emerges, too: if the CO/sub 2/ buildup continues; if the big general circulation models are right about its impact on climate, and if we have not miscalculated the potential role of the oceans, then we face a climatic change in the next century and a half like nothing the post-glacial world, and hence civilized humanity, has seen.

  4. BIFoR FACE: A ten-year Free-Air Carbon Dioxide Enrichment (FACE) Experiment in Old Growth Deciduous English Woodland

    NASA Astrophysics Data System (ADS)

    Thomas, R. M.; MacKenzie, A. R.; Ellsworth, D.; Hemming, D.; Crous, K.; Pope, F.; Blaen, P.; Poynter, A.; Hamilton, L.; Blenkhorn, D.; Jarvis-Rouse, F.

    2015-12-01

    The Birmingham Institute of Forest research (BIFoR) will perform fundamental physical, biological, ecological, social and cultural research of direct relevance to forested landscapes worldwide. A core platform for BIFoR to study the ten-year response of a mature temperate deciduous forest ecosystem to against a large step-change in atmospheric [CO2] is the BIFoR Free-Air Carbon Dioxide Enrichment (FACE) experiment. BIFoR FACE is being established in Mill Haft, a mature (~150 year-old) oak (Quercus robur) and hazel (Corylus avellana) coppice-with-standards woodland in central England. The facility will enable elevated CO2 (eCO2) treatments to be introduced in 30 m diameter rings (3 treatment and 6 control plots), commencing in spring 2016. Under eCO2 conditions primary research questions will investigate carbon uptake and storage, corresponding nutrient limitations, and biodiversity and ecosystem responses. As well as describing the facility and experimental design, we present baseline data collected throughout 2015, prior to fumigation. These data include: biophysical tree properties; atmospheric CO2/H2O fluxes; airborne and ground laser scatterometry; leaf area index; geophysical survey data; phenology camera derivatives; soil and water chemical and physical properties; and invertebrate surveys. Data from an intensive campaign conducted during august 2015 are also shown, including in- and above- canopy characterisation of biogenic VOCs using a Proton Transfer Reaction Mass Spectrometer, aerosol loading including bioaerosols, and enhanced atmospheric chemistry. Further campaign results are presented from leaf level photosynthetic carbon-dioxide response curve (A/Ci) performed at different canopy heights on oak trees, and on the dominant understory species - hazel and sycamore (Acer pseudoplatinus) across the site. BIFoR FACE is an exciting new international facility for forest science - ideas for collaborations are encouraged. Please see http

  5. Tethered catalysts for the hydration of carbon dioxide

    SciTech Connect

    Valdez, Carlos A; Satcher, Jr., Joe H; Aines, Roger D; Wong, Sergio E; Baker, Sarah E; Lightstone, Felice C; Stolaroff, Joshuah K

    2014-11-04

    A system is provided that substantially increases the efficiency of CO.sub.2 capture and removal by positioning a catalyst within an optimal distance from the air-liquid interface. The catalyst is positioned within the layer determined to be the highest concentration of carbon dioxide. A hydrophobic tether is attached to the catalyst and the hydrophobic tether modulates the position of the catalyst within the liquid layer containing the highest concentration of carbon dioxide.

  6. Carbon Dioxide Removal via Passive Thermal Approaches

    NASA Technical Reports Server (NTRS)

    Lawson, Michael; Hanford, Anthony; Conger, Bruce; Anderson, Molly

    2011-01-01

    A paper describes a regenerable approach to separate carbon dioxide from other cabin gases by means of cooling until the carbon dioxide forms carbon dioxide ice on the walls of the physical device. Currently, NASA space vehicles remove carbon dioxide by reaction with lithium hydroxide (LiOH) or by adsorption to an amine, a zeolite, or other sorbent. Use of lithium hydroxide, though reliable and well-understood, requires significant mass for all but the shortest missions in the form of lithium hydroxide pellets, because the reaction of carbon dioxide with lithium hydroxide is essentially irreversible. This approach is regenerable, uses less power than other historical approaches, and it is almost entirely passive, so it is more economical to operate and potentially maintenance- free for long-duration missions. In carbon dioxide removal mode, this approach passes a bone-dry stream of crew cabin atmospheric gas through a metal channel in thermal contact with a radiator. The radiator is pointed to reject thermal loads only to space. Within the channel, the working stream is cooled to the sublimation temperature of carbon dioxide at the prevailing cabin pressure, leading to formation of carbon dioxide ice on the channel walls. After a prescribed time or accumulation of carbon dioxide ice, for regeneration of the device, the channel is closed off from the crew cabin and the carbon dioxide ice is sublimed and either vented to the environment or accumulated for recovery of oxygen in a fully regenerative life support system.

  7. Synthesis of fluoropolymers in supercritical carbon dioxide

    SciTech Connect

    Guan, Z.; Combes, J.R.; Elsbernd, C.S.; DeSimone, J.M.

    1993-12-31

    The authors` research is focus on the synthesis of fluopolymers is supercritical carbon dioxide. The authors reported earlier the successful homogenous free radical polymerization of a series of highly fluorinated acrylic type monomers in supercritical carbon dioxide. Now it is found that a highly fluorinated styrenic polymer also exhibits very high solubility in carbon dioxide. The fluorinated styrenic polymer was synthesized in supercritical carbon dioxide using homogenous free radical polymerization and was characterized by {sup 1}HNMR, FTIR etc. Some semicrystalline fluoropolymers were also synthesized in supercritical carbon but the polymerization were heterogenous under the condition used. Various conventional nonfluorinated monomers were copolymerized with the fluorinated monomers and the copolymerizations were homogenous at very high nonfluorinated monomer feed ratio. The incorporation of nonfluorinated units onto the fluoropolymer chains increases their solubility greatly in organic solvents. The polymers synthesized in carbon dioxide will be furtherly characterized and the authors will continue the efforts on synthesizing polymers using carbon dioxide as polymerization medium.

  8. Management practices affects soil carbon dioxide emission and carbon storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural practices contribute about 25% of total anthropogenic carbon dioxide emission, a greenhouse gas responsible for global warming. Soil can act both as sink or source of atmospheric carbon dioxide. Carbon dioxide fixed in plant biomass through photosynthesis can be stored in soil as organi...

  9. Carbon dioxide detection in adult Odonata.

    PubMed

    Piersanti, Silvana; Frati, Francesca; Rebora, Manuela; Salerno, Gianandrea

    2016-04-01

    The present paper shows, by means of single-cell recordings, responses of antennal sensory neurons of the damselfly Ischnura elegans when stimulated by air streams at different CO2 concentrations. Unlike most insects, but similarly to termites, centipedes and ticks, Odonata possess sensory neurons strongly inhibited by CO2, with the magnitude of the off-response depending upon the CO2 concentration. The Odonata antennal sensory neurons responding to CO2 are also sensitive to airborne odors; in particular, the impulse frequency is increased by isoamylamine and decreased by heptanoic and pentanoic acid. Further behavioral investigations are necessary to assign a biological role to carbon dioxide detection in Odonata. PMID:26831359

  10. Development and Validation of a Novel Gas Analyzer for Simultaneous Measurements of Methane, Carbon Dioxide and Water Vapor in Ambient Air at 20 Hz

    NASA Astrophysics Data System (ADS)

    Gupta, M.; Owano, T.; Fellers, R.; Dong, F.; Baer, D.

    2008-12-01

    Methane has increased significantly with human population levels. Pre-1750 ice core data indicates that pre- industrialization levels were about 700 ppbv, while current levels are over 1750 ppbv. In current budget estimates of atmospheric methane, major contributors include both natural (wetlands) and anthropogenic sources (energy, landfills, ruminants, biomass burning, rice agriculture). The strengths of these sources vary spatially and temporally. Estimates of emissions from wetlands are also uncertain due to the extreme variability of these ecosystems. Because methane lifetime is relatively long (8.4 years), atmospheric variations in concentration are small and accuracy in measurement is important for understanding spatial and temporal variability. Atmospheric concentrations of carbon dioxide and methane rose sharply in 2007. Global CO2 climbed by 0.6 percent, or 19 billion tons, in 2007. Methane increased by 27 million tons after nearly a decade with little or no increase. Atmospheric CO2 levels currently stand at 385 ppmv, or about 38 percent higher than pre- industrial levels and the rise in CO2 concentrations has been accelerating since the 1980s when annual increases were around 1.5 ppm per year. Last year the increase was 2.4 ppm. We report on the development, application and independent performance characterization of a novel gas analyzer based on cavity-enhanced laser absorption spectroscopy. The Analyzer provides simultaneous measurements of methane, carbon dioxide and water vapor in ambient air in the field for applications that require high data rates (eddy correlation flux), wide dynamic range (e.g., chamber flux and other applications with concentrations that are ten times typical ambient levels or higher) and highest accuracy (atmospheric monitoring stations). The Analyzer provides continuous measurements at data rates up to 20 Hz and with replicate precision of 1 ppbv for methane (1 second measurement time), 0.2 ppmv for carbon dioxide (1 second

  11. Solubility of Carbon Dioxide in Water.

    ERIC Educational Resources Information Center

    Bush, Pat; And Others

    1992-01-01

    Describes an activity measuring the amount of dissolved carbon dioxide in carbonated water at different temperatures. The amount of carbon dioxide is measured by the amount of dilute ammonia solution needed to produce a pH indicator color change. (PR)

  12. 40 CFR 86.224-94 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration. 86.224-94 Section 86.224-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.224-94 Carbon...

  13. 40 CFR 86.224-94 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration. 86.224-94 Section 86.224-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.224-94 Carbon...

  14. 40 CFR 86.224-94 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 86.224-94 Section 86.224-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.224-94 Carbon...

  15. 40 CFR 86.224-94 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration. 86.224-94 Section 86.224-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.224-94 Carbon...

  16. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C....

  17. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C....

  18. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C....

  19. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C....

  20. Capture of green-house carbon dioxide in Portland cement

    SciTech Connect

    Wagh, A.S.; Singh, D.; Pullockaran, J.; Knox, L.

    1993-12-31

    A novel process has been developed to sequester green-house carbon dioxide produced by the cement industry in precast cement products. Typically, 10--24 wt % of CO{sub 2} produced by calcination of calcium carbonate during clinkering of the cement may be captured. The carbonation process also cures the cement paste within minutes into hard bodies. The process maintains high pH conditions during curing, to allow conventional steel reinforcement of concrete. The process will save time and money to the cement industry, and at the same time, help them to comply with the Clean Air Act by sequestering the green-house carbon dioxide.

  1. The use of seawater as a carbon dioxide scrubbing medium for underwater life support

    SciTech Connect

    Nuckols, M.L.

    1996-09-01

    Experimental evidence suggests that seawater could be used to scrub carbon dioxide form cabin air in underwater habitats. Seawater has the capacity to absorb carbon dioxide in quantities directly dependent on a number of variables, the most significant of which is the partial pressure of the carbon dioxide in the gas. The absorption capacities of freshwater and seawater are determined in this study in relation to the variables of carbon dioxide partial pressure, water temperature and pH for use in simple engineering design calculations. A conceptual carbon dioxide scrubber is proposed which involves the direct absorption of carbon dioxide in small concentrations in diffused air by a pressurized seawater tower. This conceptual design can potentially offer a low-energy seawater carbon dioxide scrubber to be externally or internally mounted on an underwater habitat.

  2. Ocean uptake of carbon dioxide

    SciTech Connect

    Peng, Tsung-Hung ); Takahashi, Taro . Lamont-Doherty Earth Observatory)

    1993-01-01

    Factors controlling the capacity of the ocean for taking up anthropogenic C0[sup 2] include carbon chemistry, distribution of alkalinity, pCO[sup 2] and total concentration of dissolved C0[sup 2], sea-air pCO[sup 2] difference, gas exchange rate across the sea-air interface, biological carbon pump, ocean water circulation and mixing, and dissolution of carbonate in deep sea sediments. A general review of these processes is given and models of ocean-atmosphere system based on our understanding of these regulating processes axe used to estimate the magnitude of C0[sup 2] uptake by the ocean. We conclude that the ocean can absorb up to 35% of the fossil fuel emission. Direct measurements show that 55% Of C0[sup 2] from fossil fuel burning remains in the atmosphere. The remaining 10% is not accounted for by atmospheric increases and ocean uptake. In addition, it is estimated that an amount equivalent to 30% of recent annual fossil fuel emissions is released into the atmosphere as a result of deforestation and farming. To balance global carbon budget, a sizable carbon sink besides the ocean is needed. Storage of carbon in terrestrial biosphere as a result of C0[sup 2] fertilization is a potential candidate for such missing carbon sinks.

  3. Ocean uptake of carbon dioxide

    SciTech Connect

    Peng, Tsung-Hung; Takahashi, Taro

    1993-06-01

    Factors controlling the capacity of the ocean for taking up anthropogenic C0{sup 2} include carbon chemistry, distribution of alkalinity, pCO{sup 2} and total concentration of dissolved C0{sup 2}, sea-air pCO{sup 2} difference, gas exchange rate across the sea-air interface, biological carbon pump, ocean water circulation and mixing, and dissolution of carbonate in deep sea sediments. A general review of these processes is given and models of ocean-atmosphere system based on our understanding of these regulating processes axe used to estimate the magnitude of C0{sup 2} uptake by the ocean. We conclude that the ocean can absorb up to 35% of the fossil fuel emission. Direct measurements show that 55% Of C0{sup 2} from fossil fuel burning remains in the atmosphere. The remaining 10% is not accounted for by atmospheric increases and ocean uptake. In addition, it is estimated that an amount equivalent to 30% of recent annual fossil fuel emissions is released into the atmosphere as a result of deforestation and farming. To balance global carbon budget, a sizable carbon sink besides the ocean is needed. Storage of carbon in terrestrial biosphere as a result of C0{sup 2} fertilization is a potential candidate for such missing carbon sinks.

  4. Estimated Carbon Dioxide Emissions in 2008: United States

    SciTech Connect

    Smith, C A; Simon, A J; Belles, R D

    2011-04-01

    Flow charts depicting carbon dioxide emissions in the United States have been constructed from publicly available data and estimates of state-level energy use patterns. Approximately 5,800 million metric tons of carbon dioxide were emitted throughout the United States for use in power production, residential, commercial, industrial, and transportation applications in 2008. Carbon dioxide is emitted from the use of three major energy resources: natural gas, coal, and petroleum. The flow patterns are represented in a compact 'visual atlas' of 52 state-level (all 50 states, the District of Columbia, and one national) carbon dioxide flow charts representing a comprehensive systems view of national CO{sub 2} emissions. Lawrence Livermore National Lab (LLNL) has published flow charts (also referred to as 'Sankey Diagrams') of important national commodities since the early 1970s. The most widely recognized of these charts is the U.S. energy flow chart (http://flowcharts.llnl.gov). LLNL has also published charts depicting carbon (or carbon dioxide potential) flow and water flow at the national level as well as energy, carbon, and water flows at the international, state, municipal, and organizational (i.e. United States Air Force) level. Flow charts are valuable as single-page references that contain quantitative data about resource, commodity, and byproduct flows in a graphical form that also convey structural information about the system that manages those flows. Data on carbon dioxide emissions from the energy sector are reported on a national level. Because carbon dioxide emissions are not reported for individual states, the carbon dioxide emissions are estimated using published energy use information. Data on energy use is compiled by the U.S. Department of Energy's Energy Information Administration (U.S. EIA) in the State Energy Data System (SEDS). SEDS is updated annually and reports data from 2 years prior to the year of the update. SEDS contains data on primary

  5. Will peak oil accelerate carbon dioxide emissions?

    NASA Astrophysics Data System (ADS)

    Caldeira, K.; Davis, S. J.; Cao, L.

    2008-12-01

    The relative scarcity of oil suggests that oil production is peaking and will decline thereafter. Some have suggested that this represents an opportunity to reduce carbon dioxide emissions. However, in the absence of constraints on carbon dioxide emission, "peak oil" may drive a shift towards increased reliance on coal as a primary energy source. Because coal per unit energy, in the absence of carbon capture and disposal, releases more carbon dioxide to the atmosphere than oil, "peak oil" may lead to an acceleration of carbon dioxide emissions. We will never run out of oil. As oil becomes increasingly scarce, prices will rise and therefore consumption will diminish. As prices rise, other primary energy sources will become increasingly competitive with oil. The developed world uses oil primarily as a source of transportation fuels. The developing world uses oil primarily for heat and power, but the trend is towards increasing reliance on oil for transportation. Liquid fuels, including petroleum derivatives such as gasoline and diesel fuel, are attractive as transportation fuels because of their relative abundance of energy per unit mass and volume. Such considerations are especially important for the air transport industry. Today, there is little that can compete with petroleum-derived transportation fuels. Future CO2 emissions from the transportation sector largely depend on what replaces oil as a source of fuel. Some have suggested that biomass-derived ethanol, hydrogen, or electricity could play this role. Each of these potential substitutes has its own drawbacks (e.g., low power density per unit area in the case of biomass, low power density per unit volume in the case of hydrogen, and low power density per unit mass in the case of battery storage). Thus, it is entirely likely that liquefaction of coal could become the primary means by which transportation fuels are produced. Since the burning of coal produces more CO2 per unit energy than does the burning of

  6. Carbon dioxide disposal in solid form

    SciTech Connect

    Lackner, K.S.; Butt, D.P.; Sharp, D.H.; Wendt, C.H.

    1995-12-31

    Coal reserves can provide for the world`s energy needs for centuries. However, coal`s long term use may be severely curtailed if the emission of carbon dioxide into the atmosphere is not eliminated. We present a safe and permanent method of carbon dioxide disposal that is based on combining carbon dioxide chemically with abundant raw materials to form stable carbonate minerals. We discuss the availability of raw materials and potential process designs. We consider our initial rough cost estimate of about 3{cents}/kWh encouraging. The availability of a carbon dioxide fixation technology would serve as insurance in case global warming, or the perception of global warming, causes severe restrictions on carbon dioxide emissions. If the increased energy demand of a growing world population is to be satisfied from coal, the implementation of such a technology would quite likely be unavoidable.

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

    NASA Astrophysics Data System (ADS)

    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).

  8. Silanediol-catalyzed carbon dioxide fixation.

    PubMed

    Hardman-Baldwin, Andrea M; Mattson, Anita E

    2014-12-01

    Carbon dioxide is an abundant and renewable C1 source. However, mild transformations with carbon dioxide at atmospheric pressure are difficult to accomplish. Silanediols have been discovered to operate as effective hydrogen-bond donor organocatalysts for the atom-efficient conversion of epoxides to cyclic carbonates under environmentally friendly conditions. The reaction system is tolerant of a variety of epoxides and the desired cyclic carbonates are isolated in excellent yields. PMID:25328125

  9. Carbon Dioxide for pH Control

    SciTech Connect

    Wagonner, R.C.

    2001-08-16

    Cardox, the major supplier of carbon dioxide, has developed a diffuser to introduce carbon dioxide into a water volume as small bubbles to minimize reagent loss to the atmosphere. This unit is integral to several configurations suggested for treatment to control alkalinity in water streams.

  10. Carbon dioxide sequestration by mineral carbonation

    SciTech Connect

    Gerdemann, Stephen J.; Dahlin David C.; O'Connor William K.; Penner Larry R.

    2003-11-01

    Concerns about global warming caused by the increasing concentration of carbon dioxide and other greenhouse gases in the earth’s atmosphere have resulted in the need for research to reduce or eliminate emissions of these gases. Carbonation of magnesium and calcium silicate minerals is one possible method to achieve this reduction. It is possible to carry out these reactions either in situ (storage underground and subsequent reaction with the host rock to trap CO2 as carbonate minerals) or ex situ (above ground in a more traditional chemical processing plant). Research at the Department of Energy’s Albany Research Center has explored both of these routes. This paper will explore parameters that affect the direct carbonation of magnesium silicate minerals serpentine (Mg3Si2O5(OH)4) and olivine (Mg2SiO4) to produce magnesite (MgCO3), as well as the calcium silicate mineral, wollastonite (CaSiO3), to form calcite (CaCO3). The Columbia River Basalt Group is a multi-layered basaltic lava plateau that has favorable mineralogy and structure for storage of CO2. Up to 25% combined concentration of Ca, Fe2+, and Mg cations could react to form carbonates and thus sequester large quantities of CO2. Core samples from the Columbia River Basalt Group were reacted in an autoclave for up to 2000 hours at temperatures and pressures to simulate in situ conditions. Changes in core porosity, secondary minerals, and solution chemistry were measured.

  11. Encapsulated liquid sorbents for carbon dioxide capture.

    PubMed

    Vericella, John J; Baker, Sarah E; Stolaroff, Joshuah K; Duoss, Eric B; Hardin, James O; Lewicki, James; Glogowski, Elizabeth; Floyd, William C; Valdez, Carlos A; Smith, William L; Satcher, Joe H; Bourcier, William L; Spadaccini, Christopher M; Lewis, Jennifer A; Aines, Roger D

    2015-01-01

    Drawbacks of current carbon dioxide capture methods include corrosivity, evaporative losses and fouling. Separating the capture solvent from infrastructure and effluent gases via microencapsulation provides possible solutions to these issues. Here we report carbon capture materials that may enable low-cost and energy-efficient capture of carbon dioxide from flue gas. Polymer microcapsules composed of liquid carbonate cores and highly permeable silicone shells are produced by microfluidic assembly. This motif couples the capacity and selectivity of liquid sorbents with high surface area to facilitate rapid and controlled carbon dioxide uptake and release over repeated cycles. While mass transport across the capsule shell is slightly lower relative to neat liquid sorbents, the surface area enhancement gained via encapsulation provides an order-of-magnitude increase in carbon dioxide absorption rates for a given sorbent mass. The microcapsules are stable under typical industrial operating conditions and may be used in supported packing and fluidized beds for large-scale carbon capture. PMID:25652243

  12. Encapsulated liquid sorbents for carbon dioxide capture

    NASA Astrophysics Data System (ADS)

    Vericella, John J.; Baker, Sarah E.; Stolaroff, Joshuah K.; Duoss, Eric B.; Hardin, James O.; Lewicki, James; Glogowski, Elizabeth; Floyd, William C.; Valdez, Carlos A.; Smith, William L.; Satcher, Joe H.; Bourcier, William L.; Spadaccini, Christopher M.; Lewis, Jennifer A.; Aines, Roger D.

    2015-02-01

    Drawbacks of current carbon dioxide capture methods include corrosivity, evaporative losses and fouling. Separating the capture solvent from infrastructure and effluent gases via microencapsulation provides possible solutions to these issues. Here we report carbon capture materials that may enable low-cost and energy-efficient capture of carbon dioxide from flue gas. Polymer microcapsules composed of liquid carbonate cores and highly permeable silicone shells are produced by microfluidic assembly. This motif couples the capacity and selectivity of liquid sorbents with high surface area to facilitate rapid and controlled carbon dioxide uptake and release over repeated cycles. While mass transport across the capsule shell is slightly lower relative to neat liquid sorbents, the surface area enhancement gained via encapsulation provides an order-of-magnitude increase in carbon dioxide absorption rates for a given sorbent mass. The microcapsules are stable under typical industrial operating conditions and may be used in supported packing and fluidized beds for large-scale carbon capture.

  13. Electrocatalysts for carbon dioxide conversion

    SciTech Connect

    Masel, Richard I; Salehi-Khojin, Amin

    2015-04-21

    Electrocatalysts for carbon dioxide conversion include at least one catalytically active element with a particle size above 0.6 nm. The electrocatalysts can also include a Helper Catalyst. The catalysts can be used to increase the rate, modify the selectivity or lower the overpotential of electrochemical conversion of CO.sub.2. Chemical processes and devices using the catalysts also include processes to produce CO, HCO.sup.-, H.sub.2CO, (HCO.sub.2).sup.-, H.sub.2CO.sub.2, CH.sub.3OH, CH.sub.4, C.sub.2H.sub.4, CH.sub.3CH.sub.2OH, CH.sub.3COO.sup.-, CH.sub.3COOH, C.sub.2H.sub.6, (COOH).sub.2, or (COO.sup.-).sub.2, and a specific device, namely, a CO.sub.2 sensor.

  14. Carbon dioxide cleaning pilot project

    SciTech Connect

    Knight, L.; Blackman, T.E.

    1994-01-21

    In 1989, radioactive-contaminated metal at the Rocky Flats Plant (RFP) was cleaned using a solvent paint stripper (Methylene chloride). One-third of the radioactive material was able to be recycled; two-thirds went to the scrap pile as low-level mixed waste. In addition, waste solvent solutions also required disposal. Not only was this an inefficient process, it was later prohibited by the Resource Conservation and Recovery Act (RCRA), 40 CFR 268. A better way of doing business was needed. In the search for a solution to this situation, it was decided to study the advantages of using a new technology - pelletized carbon dioxide cleaning. A proof of principle demonstration occurred in December 1990 to test whether such a system could clean radioactive-contaminated metal. The proof of principle demonstration was expanded in June 1992 with a pilot project. The purpose of the pilot project was three fold: (1) to clean metal so that it can satisfy free release criteria for residual radioactive contamination at the Rocky Flats Plant (RFP); (2) to compare two different carbon dioxide cleaning systems; and (3) to determine the cost-effectiveness of decontamination process in a production situation and compare the cost of shipping the metal off site for waste disposal. The pilot project was completed in August 1993. The results of the pilot project were: (1) 90% of those items which were decontaminated, successfully met the free release criteria , (2) the Alpheus Model 250 was selected to be used on plantsite and (3) the break even cost of decontaminating the metal vs shipping the contaminated material offsite for disposal was a cleaning rate of 90 pounds per hour, which was easily achieved.

  15. Air quality at Santiago, Chile: a box modeling approach—I. Carbon monoxide, nitrogen oxides and sulfur dioxide

    NASA Astrophysics Data System (ADS)

    Jorquera, Héctor

    Ambient monitored data at Santiago, Chile, are analyzed using box models with the goal of assessing contributions of different economic activities to air pollution levels. The period analyzed is 1990-2000, characterized by the introduction of air pollution emissions standards, shift to unleaded gasoline and compressed natural gas, and steady growth of the private and public fleet and the associated fuel consumption growth. The box models explicitly include the seasonal behavior of meteorological variables; the results show that dispersion conditions in fall and winter seasons are 20-30% of the summertime values. This result explains the poor air quality in those seasons and shows that significant emissions reductions are required in order to improve air quality in wintertime. Emissions of CO, NO x and SO 2 are estimated from data on fuel consumption in the city; the estimated parameters are thus fleet-average or industry-average emission factors. In terms of contributions to ambient concentrations, older cars and diesel vehicles are the major contributors to CO and NO x impacts, with more than 60% and 50%, respectively. Ambient concentrations of SO 2 are largely dominated by stationary sources, although long range contributions are not negligible. By contrast, CO and NO x pollution is dominated by local sources within the city boundaries. The box models can be used for forecasting purposes, and they can predict annual average concentrations within 20% of the observed values. The methodology requires data on ambient air quality measurements and fuel consumption statistics, and produces quantitative results, which can be combined with economic models to analyze environmental regulation and public policies.

  16. Carbon dioxide capture process with regenerable sorbents

    DOEpatents

    Pennline, Henry W.; Hoffman, James S.

    2002-05-14

    A process to remove carbon dioxide from a gas stream using a cross-flow, or a moving-bed reactor. In the reactor the gas contacts an active material that is an alkali-metal compound, such as an alkali-metal carbonate, alkali-metal oxide, or alkali-metal hydroxide; or in the alternative, an alkaline-earth metal compound, such as an alkaline-earth metal carbonate, alkaline-earth metal oxide, or alkaline-earth metal hydroxide. The active material can be used by itself or supported on a substrate of carbon, alumina, silica, titania or aluminosilicate. When the active material is an alkali-metal compound, the carbon-dioxide reacts with the metal compound to generate bicarbonate. When the active material is an alkaline-earth metal, the carbon dioxide reacts with the metal compound to generate carbonate. Spent sorbent containing the bicarbonate or carbonate is moved to a second reactor where it is heated or treated with a reducing agent such as, natural gas, methane, carbon monoxide hydrogen, or a synthesis gas comprising of a combination of carbon monoxide and hydrogen. The heat or reducing agent releases carbon dioxide gas and regenerates the active material for use as the sorbent material in the first reactor. New sorbent may be added to the regenerated sorbent prior to subsequent passes in the carbon dioxide removal reactor.

  17. Growth and yield response of field-grown tropical rice to increasing carbon dioxide and air temperature

    SciTech Connect

    Ziska, L.H.; Namuco, O.; Moya, T.; Quilang, J.

    1997-01-01

    Although the response of rice (Oryza sativa L.) to increasing atmospheric CO{sub 2} concentration and air temperature has been examined at the greenhouse or growth chamber level, no field studies have been conducted under the tropical, irrigated conditions where the bulk of the world`s rice is grown. At the International Rice Research Institute, rice (cv. IR 72) was grown from germination until maturity for the 1994 wet and 1995 dry seasons at three different CO{sub 2} concentrations (ambient, ambient + 200, and ambient + 300 {mu}L L{sup {minus}1}) resulted in a significant increase in total plant biomass (+31%, +40%) and crop yield (+15%, + 27%) compared with the ambient control. The increase in crop yield was associated with an increase in the number of panicles per square meter and a greater percentage of filled spikelets. Simultaneous increases in CO{sub 2} and air temperature did not alter the biomass at maturity (relative to elevated CO{sub 2} alone), but plant development was accelerated at the higher growth temperature regardless of CO{sub 2} concentration. Grain yield, however, became insensitive to CO{sub 2} concentration at the higher growth temperature. Increasing both CO{sub 2} and air temperature also reduced grain quality (e.g., protein content). The combination of CO{sub 2} and temperature effects suggests that, in warmer regions (i.e., >34{degrees}C) where rice is grown, quantitative and qualitative changes in rice supply are possible if both CO{sub 2} and air temperature continue to increase. 24 refs., 6 figs., 4 tabs.

  18. The role of carbon dioxide in ammonia emission from manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia emission from manure is a significant loss of fixed N from agricultural systems, and contributes to air pollution and ecosystem degradation. Despite the development of numerous mathematical models for predicting ammonia emission, the interactions between carbon dioxide emission, manure pH, a...

  19. Response of sugarcane to carbon dioxide enrichment and elevated temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four sugarcane cultivars (CP72-2086, CP73-1547, CP88-1508, and CP80-1827) were grown in elongated temperature-gradient greenhouses (TGG) at ambient or elevated carbon dioxide (CO2) of 360 or 720 µmol CO2 mol-1 air, respectively. Each TGG maintained temperatures in four zones at Base temperature wit...

  20. System design and analysis of the trans-critical carbon-dioxide automotive air-conditioning system.

    PubMed

    Mu, Jing-Yang; Chen, Jiang-Ping; Chen, Zhi-Jiu

    2003-01-01

    As an environmentally harmless and feasible alternate refrigerant, CO2 has attracted worldwide attention, especially in the area of automobile air-conditioning (AAC). The thermal property of CO2 and its trans-critical refrigeration cycle is very different from that of the traditional CFC or HCFC system. The detailed process of CO2 system thermal cycle design and optimization is described in this paper. System prototype and performance test bench were developed to analyze the performance of the CO2 AAC system. PMID:12765284

  1. Effects of pulses of elevated carbon dioxide concentration on stomatal conductance and photosynthesis in wheat and rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Free air carbon dioxide enrichment (FACE) systems typically expose plants to pulses of carbon dioxide concentrations considerably above the control set-point, in addition to increasing the mean concentration. The importance of such pulses of higher carbon dioxide concentrations to plant function is...

  2. Spatial and temporal variability of heat, water vapor, carbon dioxide, and momentum air-sea exchange in a coastal environment

    NASA Astrophysics Data System (ADS)

    Crawford, Timothy L.; McMillen, Robert T.; Meyers, Tilden P.; Hicks, Bruce B.

    1993-07-01

    Simultaneous eddy correlation measurements from a tower, a boat, and an aircraft platform are used to assess the spatial and temporal variability of heat, moisture, momentum, and CO2 turbulent fluxes in a coastal environment. Dissolved CO2 in the coastal waters and atmospheric CO2 concentrations were continuously measured throughout the experiment. Good agreement was found among the different sensing systems. Air-to-sea gas, momentum, and energy flux density measurements are shown to be achievable from both a boat and an aircraft. The observed 10 W/sq m sensible heat flux was time-invariant but did not vary spatially with surface temperature, which was strongly correlated with ocean depth. The 100 to 200 W/sq m evaporative moisture flux dominated energy exchange and varied both in time and space. No consistent diurnal variation was observed, but the spatial trend also followed surface temperature. CO2 exchange exhibited large spatial and temporal variance.

  3. Ruthenium oxide modified titanium dioxide nanotube arrays as carbon and binder free lithium-air battery cathode catalyst

    NASA Astrophysics Data System (ADS)

    Zhao, Guangyu; Niu, Yanning; Zhang, Li; Sun, Kening

    2014-12-01

    RuO2 modified TiO2 nanotube arrays, growing on Ti foams, are used as carbon and binder free cathodes for Li-O2 batteries. The micrometer pores in Ti foams and nanometer pores in TiO2 nanotubes supply facilitated transport channels for oxygen diffusing into/out of the catalysts in discharge and charge processes. The RuO2 catalyst exhibits outstanding catalytic active toward oxygen evolution reaction (OER), which leads the charge voltage maintaining around 3.7 V all through the battery cycling. The stability of TiO2/Ti support, abundant oxygen transport path and favorable catalytic activity of RuO2 toward OER enable the Li-O2 batteries exhibiting 130 cycle discharge/charge.

  4. Carbon dioxide conversion over carbon-based nanocatalysts.

    PubMed

    Khavarian, Mehrnoush; Chai, Siang-Piao; Mohamed, Abdul Rahman

    2013-07-01

    The utilization of carbon dioxide for the production of valuable chemicals via catalysts is one of the efficient ways to mitigate the greenhouse gases in the atmosphere. It is known that the carbon dioxide conversion and product yields are still low even if the reaction is operated at high pressure and temperature. The carbon dioxide utilization and conversion provides many challenges in exploring new concepts and opportunities for development of unique catalysts for the purpose of activating the carbon dioxide molecules. In this paper, the role of carbon-based nanocatalysts in the hydrogenation of carbon dioxide and direct synthesis of dimethyl carbonate from carbon dioxide and methanol are reviewed. The current catalytic results obtained with different carbon-based nanocatalysts systems are presented and how these materials contribute to the carbon dioxide conversion is explained. In addition, different strategies and preparation methods of nanometallic catalysts on various carbon supports are described to optimize the dispersion of metal nanoparticles and catalytic activity. PMID:23901504

  5. 46 CFR 196.37-8 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 196.37-8 Section 196.37-8... Markings for Fire and Emergency Equipment, etc. § 196.37-8 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space...

  6. 46 CFR 95.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

  7. 46 CFR 76.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  8. 46 CFR 169.732 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.”...

  9. 46 CFR 78.47-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 78.47-11 Section 78.47-11... Fire and Emergency Equipment, Etc. § 78.47-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into...

  10. 46 CFR 97.37-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 97.37-11 Section 97.37-11... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  11. 46 CFR 78.47-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 78.47-11 Section 78.47-11... Fire and Emergency Equipment, Etc. § 78.47-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into...

  12. 46 CFR 76.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  13. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20... PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-20 Carbon dioxide...-5(d), consisting of not more than 300 pounds of carbon dioxide, may have cylinders located...

  14. 46 CFR 97.37-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 97.37-11 Section 97.37-11... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  15. 46 CFR 131.817 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 131.817 Section 131.817... Markings for Fire Equipment and Emergency Equipment § 131.817 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  16. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20... PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-20 Carbon dioxide...-5(d), consisting of not more than 300 pounds of carbon dioxide, may have cylinders located...

  17. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture...

  18. 46 CFR 97.37-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping... Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  19. 46 CFR 97.37-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping... Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  20. 46 CFR 108.627 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping... EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM SOUNDS VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED” next...

  1. 46 CFR 108.627 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping... EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM SOUNDS VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED” next...

  2. 46 CFR 95.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

  3. 46 CFR 95.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

  4. 46 CFR 95.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

  5. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture...

  6. 46 CFR 108.626 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 108.626 Section 108.626... AND EQUIPMENT Equipment Markings and Instructions § 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  7. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture...

  8. 46 CFR 108.626 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 108.626 Section 108.626... AND EQUIPMENT Equipment Markings and Instructions § 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  9. 46 CFR 76.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  10. 46 CFR 131.817 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 131.817 Section 131.817... Markings for Fire Equipment and Emergency Equipment § 131.817 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  11. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture...

  12. 46 CFR 76.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  13. 46 CFR 78.47-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 78.47-11 Section 78.47-11... Fire and Emergency Equipment, Etc. § 78.47-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into...

  14. 46 CFR 196.37-8 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 196.37-8 Section 196.37-8... Markings for Fire and Emergency Equipment, etc. § 196.37-8 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space...

  15. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a...), consisting of not more than 300 pounds of carbon dioxide, may have cylinders located within the...

  16. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture...

  17. 46 CFR 97.37-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 97.37-11 Section 97.37-11... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  18. 46 CFR 196.37-8 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 196.37-8 Section 196.37-8... Markings for Fire and Emergency Equipment, etc. § 196.37-8 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space...

  19. 46 CFR 108.626 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 108.626 Section 108.626... AND EQUIPMENT Equipment Markings and Instructions § 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  20. 46 CFR 196.37-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide alarm. 196.37-9 Section 196.37-9 Shipping... Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  1. 46 CFR 95.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

  2. 46 CFR 196.37-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 196.37-9 Section 196.37-9 Shipping... Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  3. 46 CFR 131.817 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 131.817 Section 131.817... Markings for Fire Equipment and Emergency Equipment § 131.817 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  4. 46 CFR 78.47-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping... and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” (b)...

  5. 46 CFR 78.47-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping... and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” (b)...

  6. 46 CFR 76.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  7. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20... PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-20 Carbon dioxide...-5(d), consisting of not more than 300 pounds of carbon dioxide, may have cylinders located...

  8. 46 CFR 169.732 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.”...

  9. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a...), consisting of not more than 300 pounds of carbon dioxide, may have cylinders located within the...

  10. Sex differences in panic-relevant responding to a 10% carbon dioxide-enriched air biological challenge.

    PubMed

    Nillni, Yael I; Berenz, Erin C; Rohan, Kelly J; Zvolensky, Michael J

    2012-01-01

    The current study examined sex differences in psychological (i.e., self-reported anxiety, panic symptoms, and avoidance) and physiological (i.e., heart rate and skin conductance level) response to, and recovery from, a laboratory biological challenge. Participants were a community-recruited sample of 128 adults (63.3% women; M(age)=23.2 years, SD=8.9) who underwent a 4-min 10% CO(2)-enriched air biological challenge. As predicted, women reported more severe physical panic symptoms and avoidance (i.e., less willingness to participate in another challenge) and demonstrated increased heart rate as compared to men above and beyond the variance accounted for by other theoretically relevant variables (recent panic attack history, neuroticism, and anxiety sensitivity). Additionally, women demonstrated a faster rate of recovery with respect to heart rate compared to men. These results are in line with literature documenting sex-specific differences in panic psychopathology, and results are discussed in the context of possible mechanisms underlying sex differences in panic vulnerability. PMID:22115836

  11. An indica rice genotype showed a similar yield enhancement to that of hybrid rice under free air carbon dioxide enrichment.

    PubMed

    Zhu, Chunwu; Xu, Xi; Wang, Dan; Zhu, Jianguo; Liu, Gang

    2015-01-01

    Although the rice growth response to FACE (free-air CO2 enrichment) has been widely studied and is considered important within the scientific community, few studies have attempted to examine the effects of FACE on the yield of indica rice, which is typically the parent of indica hybrids in China. The effects of FACE on the yield, yield components, biomass, N uptake and leaf photosynthesis of Yangdao 6 Hao (an indica rice) in China were examined over 2 years. The grain yield increased over 30%, the panicle number increased 12.4% on average, and the spikelet number per panicle also showed an average increase of 8.2% at elevated CO2. FACE caused a significant enhancement in both the filled spikelet percentage (+5.9%) and the individual grain weight (+3.0%). Compared with three prior FACE studies on rice, a similar enhancement of yield in hybrid indica was shown under FACE, with much a higher value than for the japonica rice cultivar (approximately + 13%) because of indica's stronger sink generation and N uptake capacity, which help coordinate the C/N balance to avoid photosynthetic acclimation. The high enhancement of the indica rice yield under FACE holds promise for improved cultivar selection for future food security. PMID:26228872

  12. An indica rice genotype showed a similar yield enhancement to that of hybrid rice under free air carbon dioxide enrichment

    PubMed Central

    Zhu, Chunwu; Xu, Xi; Wang, Dan; Zhu, Jianguo; Liu, Gang

    2015-01-01

    Although the rice growth response to FACE (free-air CO2 enrichment) has been widely studied and is considered important within the scientific community, few studies have attempted to examine the effects of FACE on the yield of indica rice, which is typically the parent of indica hybrids in China. The effects of FACE on the yield, yield components, biomass, N uptake and leaf photosynthesis of Yangdao 6 Hao (an indica rice) in China were examined over 2 years. The grain yield increased over 30%, the panicle number increased 12.4% on average, and the spikelet number per panicle also showed an average increase of 8.2% at elevated CO2. FACE caused a significant enhancement in both the filled spikelet percentage (+5.9%) and the individual grain weight (+3.0%). Compared with three prior FACE studies on rice, a similar enhancement of yield in hybrid indica was shown under FACE, with much a higher value than for the japonica rice cultivar (approximately + 13%) because of indica’s stronger sink generation and N uptake capacity, which help coordinate the C/N balance to avoid photosynthetic acclimation. The high enhancement of the indica rice yield under FACE holds promise for improved cultivar selection for future food security. PMID:26228872

  13. An indica rice genotype showed a similar yield enhancement to that of hybrid rice under free air carbon dioxide enrichment

    NASA Astrophysics Data System (ADS)

    Zhu, Chunwu; Xu, Xi; Wang, Dan; Zhu, Jianguo; Liu, Gang

    2015-07-01

    Although the rice growth response to FACE (free-air CO2 enrichment) has been widely studied and is considered important within the scientific community, few studies have attempted to examine the effects of FACE on the yield of indica rice, which is typically the parent of indica hybrids in China. The effects of FACE on the yield, yield components, biomass, N uptake and leaf photosynthesis of Yangdao 6 Hao (an indica rice) in China were examined over 2 years. The grain yield increased over 30%, the panicle number increased 12.4% on average, and the spikelet number per panicle also showed an average increase of 8.2% at elevated CO2. FACE caused a significant enhancement in both the filled spikelet percentage (+5.9%) and the individual grain weight (+3.0%). Compared with three prior FACE studies on rice, a similar enhancement of yield in hybrid indica was shown under FACE, with much a higher value than for the japonica rice cultivar (approximately + 13%) because of indica’s stronger sink generation and N uptake capacity, which help coordinate the C/N balance to avoid photosynthetic acclimation. The high enhancement of the indica rice yield under FACE holds promise for improved cultivar selection for future food security.

  14. Carbon dioxide-soluble polymers and swellable polymers for carbon dioxide applications

    DOEpatents

    DeSimone, Joseph M.; Birnbaum, Eva; Carbonell, Ruben G.; Crette, Stephanie; McClain, James B.; McCleskey, T. Mark; Powell, Kimberly R.; Romack, Timothy J.; Tumas, William

    2004-06-08

    A method for carrying out a catalysis reaction in carbon dioxide comprising contacting a fluid mixture with a catalyst bound to a polymer, the fluid mixture comprising at least one reactant and carbon dioxide, wherein the reactant interacts with the catalyst to form a reaction product. A composition of matter comprises carbon dioxide and a polymer and a reactant present in the carbon dioxide. The polymer has bound thereto a catalyst at a plurality of chains along the length of the polymer, and wherein the reactant interacts with the catalyst to form a reaction product.

  15. Hydraulic time constants for transpiration of loblolly pine at a free-air carbon dioxide enrichment site.

    PubMed

    Ward, Eric J; Bell, David M; Clark, James S; Oren, Ram

    2013-02-01

    The impact of stored water on estimates of transpiration from scaled sap flux measurements was assessed in mature Pinus taeda (L.) at the Duke Free-Air CO(2) Enrichment (FACE) site. We used a simple hydraulic model with measurements of sap flux (J) at breast height and the base of the live crown for 26 trees over 6 months to examine the effects of elevated CO(2) (eCO(2)) and fertilization (N(F)) treatments, as well as temporal variation in soil moisture (M(()(t)())), on estimates of the hydraulic time constant (κ). At low M(()(t)()), there was little (<12%) difference in κ of different treatments. At high M(()(t)()), differences were much greater, with κ reductions of 27, 52 and 34% in eCO(2), N(F) and eCO(2) × N(F) respective to the control. Incorporating κ with these effects into the analysis of a larger data set of previous J measurements at this site (1998-2008) improved agreement between modeled and measured values in 92% of cases. However, a simplified calibration of κ that neglected treatment and soil moisture effects performed more dependably, improving agreement in 98% of cases. Incorporating κ had the effect of increasing estimates of reference stomatal conductance at 1 kPa vapor pressure deficit (VPD) and saturating photosynthetic active radiation (PAR) an average of 12-14%, while increasing estimated sensitivities to VPD and PAR. A computationally efficient hydraulic model, such as the one presented here, incorporated into a hierarchical model of stomatal conductance presents a novel approach to including hydraulic time constants in estimates of stomatal responses from long-term sap flux data sets. PMID:23192973

  16. Inhibition of Frying Oil Oxidation by Carbon Dioxide Blanketing.

    PubMed

    Totani, Nagao; Inoue, Ryota; Yawata, Miho

    2016-06-01

    The oxidation of oil starts, in general, from the penetration of atmospheric oxygen into oil. Inhibition of the vigorous oxidation of oil at deep-frying temperature under carbon dioxide flow, by disrupting the contact between oil and air, was first demonstrated using oil in a round bottom flask. Next, the minimum carbon dioxide flow rate necessary to blanket 4 L of frying oil in an electric fryer (surface area 690 cm(2)) installed with nonwoven fabric cover, was found to be 40 L/h. Then deep-frying of potato was done accordingly; immediately after deep-frying, an aluminum cover was placed on top of the nonwoven fabric cover to prevent the loss of carbon dioxide and the carbon dioxide flow was shut off. In conclusion, the oxidation of oil both at deep-frying temperature and during standing was remarkably inhibited by carbon dioxide blanketing at a practical flow rate and volume. Under the deep-frying conditions employed in this study, the increase in polar compound content was reduced to half of that of the control. PMID:27181248

  17. Mineralization strategies for carbon dioxide sequestration

    SciTech Connect

    Penner, Larry R.; O'Connor, William K.; Gerdemann, Stephen J.; Dahlin, David C.

    2003-01-01

    Progress is reported in three primary research areas--each concerned with sequestering carbon dioxide into mineral matrices. Direct mineral carbonation was pioneered at Albany Research Center. The method treats the reactant, olivine or serpentine in aqueous media with carbon dioxide at high temperature and pressure to form stable mineral carbonates. Recent results are introduced for pretreatment by high-intensity grinding to improve carbonation efficiency. To prove feasibility of the carbonation process, a new reactor was designed and operated to progress from batch tests to continuous operation. The new reactor is a prototype high-temperature, high-pressure flow loop reactor that will furnish information on flow, energy consumption, and wear and corrosion resulting from slurry flow and the carbonation reaction. A promising alternative mineralization approach is also described. New data are presented for long-term exposure of carbon dioxide to Colombia River Basalt to determine the extent of conversion of carbon dioxide to permanent mineral carbonates. Batch autoclave tests were conducted using drill-core samples of basalt and reacted under conditions that simulate in situ injection into basalt-containing geological formations.

  18. Comparison of Global Model Results from the Carbon-Land Model Intercomparison Project (C-LAMP) with Free-Air Carbon Dioxide Enrichment (FACE) Manipulation Experiments

    SciTech Connect

    Hoffman, Forrest M; Randerson, Jim; Fung, Inez; Thornton, Peter E; Covey, Curtis; Bonan, Gordon; Running, Steven; Norby, Richard J

    2008-01-01

    Free-Air CO{sub 2} Enrichment (FACE) manipulation experiments have been carried out at a handful of sites to gauge the response of the biosphere to significant increases in atmospheric [CO{sub 2}]. Early synthesis results from four temperate forest sites suggest that the response of net primary productivity (NPP) is conserved across a broad range of productivity with a stimulation at the median of 23 {+-} 2% when the surrounding air [CO{sub 2}] was raised to 550{approx}ppm. As a part of the Carbon-Land Model Intercomparison Project (C-LAMP), a community-based model-data comparison activity, the authors have performed a global FACE modeling experiment using two terrestrial biogeochemistry modules, CLM3-CASA and CLM3-CN, coupled to the National Center for Atmospheric Research (NCAR) Community Climate System Model (CCSM). The two models were forced with an improved NCEP/NCAR reanalysis data set and reconstructed atmospheric [CO{sub 2}] and N deposition data through 1997. At the beginning of 1997 in the transient simulations, global atmospheric [CO{sub 2}] was abruptly raised to 550{approx}ppm, the target value used at the FACE sites. In the control runs, [CO{sub 2}] continued to rise following observations until 2004, after which it was held constant out to year 2100. In both simulations, the last 25 years of reanalysis forcing and a constant N deposition were applied after year 2004. Across all forest biomes, the NPP responses from both models are weaker than those reported for the four FACE sites. Moreover, model responses vary widely geographically with a decreasing trend of NPP increases from 40{sup o}N to 70{sup o}N. For CLM3-CASA, the largest responses occur in arid regions of western North America and central Asia, suggesting that responses are most strongly influenced by increased water use efficiency for this model. CLM3-CN exhibits consistently weaker responses than CLM3-CASA' with the strongest responses in central Asia, but significantly constrained by N

  19. Turning carbon dioxide into fuel.

    PubMed

    Jiang, Z; Xiao, T; Kuznetsov, V L; Edwards, P P

    2010-07-28

    Our present dependence on fossil fuels means that, as our demand for energy inevitably increases, so do emissions of greenhouse gases, most notably carbon dioxide (CO2). To avoid the obvious consequences on climate change, the concentration of such greenhouse gases in the atmosphere must be stabilized. But, as populations grow and economies develop, future demands now ensure that energy will be one of the defining issues of this century. This unique set of (coupled) challenges also means that science and engineering have a unique opportunity-and a burgeoning challenge-to apply their understanding to provide sustainable energy solutions. Integrated carbon capture and subsequent sequestration is generally advanced as the most promising option to tackle greenhouse gases in the short to medium term. Here, we provide a brief overview of an alternative mid- to long-term option, namely, the capture and conversion of CO2, to produce sustainable, synthetic hydrocarbon or carbonaceous fuels, most notably for transportation purposes. Basically, the approach centres on the concept of the large-scale re-use of CO2 released by human activity to produce synthetic fuels, and how this challenging approach could assume an important role in tackling the issue of global CO2 emissions. We highlight three possible strategies involving CO2 conversion by physico-chemical approaches: sustainable (or renewable) synthetic methanol, syngas production derived from flue gases from coal-, gas- or oil-fired electric power stations, and photochemical production of synthetic fuels. The use of CO2 to synthesize commodity chemicals is covered elsewhere (Arakawa et al. 2001 Chem. Rev. 101, 953-996); this review is focused on the possibilities for the conversion of CO2 to fuels. Although these three prototypical areas differ in their ultimate applications, the underpinning thermodynamic considerations centre on the conversion-and hence the utilization-of CO2. Here, we hope to illustrate that advances

  20. Self-Cleaning Boudouard Reactor for Full Oxygen Recovery from Carbon Dioxide

    NASA Technical Reports Server (NTRS)

    Hintze, Paul E.; Muscatello, Anthony C.; Gibson, Tracy L.; Captain, James G.; Lunn, Griffin M.; Devor, Robert W.; Bauer, Brint; Parks, Steve

    2016-01-01

    Oxygen recovery from respiratory carbon dioxide is an important aspect of human spaceflight. Methods exist to sequester the carbon dioxide, but production of oxygen needs further development. The current International Space Station Carbon Dioxide Reduction System (CRS) uses the Sabatier reaction to produce water (and ultimately breathing air). Oxygen recovery is limited to 50% because half of the hydrogen used in the Sabatier reactor is lost as methane which is vented overboard. The Bosch reaction, which converts carbon dioxide to oxygen and solid carbon, is capable of recovering all the oxygen from carbon dioxide, and it is a promising alternative to the Sabatier reaction. However, the last reaction in the cycle, the Boudouard reaction, produces solid carbon, and the resulting carbon buildup eventually fouls the catalyst, reducing reactor life and increasing consumables. To minimize this fouling and increase efficiency, a number of self-cleaning catalyst designs have been created. This paper will describe recent results evaluating one of the designs.

  1. Electrocatalytic Reduction of Carbon Dioxide to Methane

    NASA Technical Reports Server (NTRS)

    Sammells, Anthony F.; Spiegel, Ella F.

    2008-01-01

    A room-temperature electrocatalytic process that effects the overall chemical reaction CO2 + 2H2O yields CH4 + 2O2 has been investigated as a means of removing carbon dioxide from air and restoring oxygen to the air. The process was originally intended for use in a spacecraft life-support system, in which the methane would be vented to outer space. The process may also have potential utility in terrestrial applications in which either or both of the methane and oxygen produced might be utilized or vented to the atmosphere. A typical cell used to implement the process includes a polymer solid-electrolyte membrane, onto which are deposited cathode and anode films. The cathode film is catalytic for electrolytic reduction of CO2 at low overpotential. The anode film is typically made of platinum. When CO2 is circulated past the cathode, water is circulated past the anode, and a suitable potential is applied, the anode half-cell reaction is 4H2O yields 2O2 + 8H(+) + 8e(-). The H(+) ions travel through the membrane to the cathode, where they participate in the half-cell reaction CO2 + 8H(+) + 8e(-) yields CH4 + 2H2O.

  2. Method for extracting and sequestering carbon dioxide

    DOEpatents

    Rau, Gregory H.; Caldeira, Kenneth G.

    2005-05-10

    A method and apparatus to extract and sequester carbon dioxide (CO.sub.2) from a stream or volume of gas wherein said method and apparatus hydrates CO.sub.2, and reacts the resulting carbonic acid with carbonate. Suitable carbonates include, but are not limited to, carbonates of alkali metals and alkaline earth metals, preferably carbonates of calcium and magnesium. Waste products are metal cations and bicarbonate in solution or dehydrated metal salts, which when disposed of in a large body of water provide an effective way of sequestering CO.sub.2 from a gaseous environment.

  3. Apparatus for extracting and sequestering carbon dioxide

    DOEpatents

    Rau, Gregory H.; Caldeira, Kenneth G.

    2010-02-02

    An apparatus and method associated therewith to extract and sequester carbon dioxide (CO.sub.2) from a stream or volume of gas wherein said apparatus hydrates CO.sub.2 and reacts the resulting carbonic acid with carbonate. Suitable carbonates include, but are not limited to, carbonates of alkali metals and alkaline earth metals, preferably carbonates of calcium and magnesium. Waste products are metal cations and bicarbonate in solution or dehydrated metal salts, which when disposed of in a large body of water provide an effective way of sequestering CO.sub.2 from a gaseous environment.

  4. Method for Extracting and Sequestering Carbon Dioxide

    SciTech Connect

    Rau, Gregory H.; Caldeira, Kenneth G.

    2005-05-10

    A method and apparatus to extract and sequester carbon dioxide (CO2) from a stream or volume of gas wherein said method and apparatus hydrates CO2, and reacts the resulting carbonic acid with carbonate. Suitable carbonates include, but are not limited to, carbonates of alkali metals and alkaline earth metals, preferably carbonates of calcium and magnesium. Waste products are metal cations and bicarbonate in solution or dehydrated metal salts, which when disposed of in a large body of water provide an effective way of sequestering CO2 from a gaseous environment.

  5. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

    K.A.M. Gasem; R.L. Robinson, Jr.; J.E. Fitzgerald; Z. Pan; M. Sudibandriyo

    2003-04-30

    The authors' long-term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure, and adsorbent types. The originally-stated, major objectives of the current project are to: (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen, and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coals being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane, and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. As this project developed, an important additional objective was added to the above original list. Namely, we were encouraged to interact with industry and/or governmental agencies to utilize our expertise to advance the state of the art in coalbed adsorption science and technology. As a result of this additional objective, we participated with the Department of Energy and industry in the measurement and analysis of adsorption behavior as part of two distinct investigations. These include (a) Advanced Resources International (ARI) DOE Project DE-FC26-00NT40924, ''Adsorption of Pure Methane, Nitrogen, and Carbon Dioxide and Their Mixtures on Wet Tiffany Coal'', and (b) the DOE-NETL Project, ''Round Robin: CO{sub 2} Adsorption on Selected Coals''. These activities, contributing directly to the DOE projects listed above, also

  6. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

    K.A.M. Gasem; R.L. Robinson, Jr.; L.R. Radovic

    2003-03-10

    The authors' long-term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure and adsorbent types. The originally-stated, major objectives of the current project are to (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen, and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coals being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. As this project has developed, an important additional objective has been added to the above original list. Namely, we have been encouraged to interact with industry and/or governmental agencies to utilize our expertise to advance the state of the art in coalbed adsorption science and technology. As a result of this additional objective, we have participated with the Department of Energy and industry in the measurement and analysis of adsorption behavior as part of two distinct investigations. These include (a) Advanced Resources International (ARI) DOE Project DE-FC26-00NT40924, ''Adsorption of Pure Methane, Nitrogen, and Carbon Dioxide and Their Mixtures on Wet Tiffany Coal'', and (b) the DOE-NETL Project, ''Round Robin: CO{sub 2} Adsorption on Selected Coals''. These activities, contributing directly to the DOE projects

  7. Indirect methods for characterization of carbon dioxide levels in fermentation broth.

    PubMed

    Frick, R; Junker, B

    1999-01-01

    Various factors which influence dissolved carbon dioxide levels were indirectly evaluated in pilot scale and laboratory studies. For pilot scale studies, off-gas carbon dioxide (percentage in exit air) was measured using a mass spectrometer and then its potential impact on dissolved carbon dioxide concentrations qualitatively examined. Greater volumetric air flowrates reduced off-gas carbon dioxide levels more effectively at lower airflow ranges and thus lowered expected dissolved carbon dioxide levels through gas stripping. Lower broth pH values decreased off-gas carbon dioxide levels but increased expected dissolved carbon dioxide levels due to the pH-dependence of the gas/liquid carbon dioxide equilibrium. While back-pressure increases had an insignificant effect on off-gas carbon dioxide levels, they directly affected expected dissolved carbon dioxide levels according to Henry's law. Laboratory studies, conducted using both uninoculated and inoculated fermentation media, quantified the response of the media to pH changes with bicarbonate addition, specifically its buffering capacity. This effect then was related qualitatively to expected dissolved carbon dioxide levels. Higher dissolved carbon dioxide levels, as demonstrated by reduced pH changes with bicarbonate addition, thus would be expected for salt solutions of increased ionic strength and higher protein content media. In addition, pH changes with greater bicarbonate additions declined for fermentation samples taken over the course of a one week cultivation, most likely due to the higher protein content associated with biomass growth. The presence of weak acids/bases initially in the media or formed as metabolic by products, as well as the concentration of buffering ions such as phosphate, also were believed to be important contributing elements to the buffering capacity of the solution. PMID:16232479

  8. Polymers for metal extractions in carbon dioxide

    DOEpatents

    DeSimone, Joseph M.; Tumas, William; Powell, Kimberly R.; McCleskey, T. Mark; Romack, Timothy J.; McClain, James B.; Birnbaum, Eva R.

    2001-01-01

    A composition useful for the extraction of metals and metalloids comprises (a) carbon dioxide fluid (preferably liquid or supercritical carbon dioxide); and (b) a polymer in the carbon dioxide, the polymer having bound thereto a ligand that binds the metal or metalloid; with the ligand bound to the polymer at a plurality of locations along the chain length thereof (i.e., a plurality of ligands are bound at a plurality of locations along the chain length of the polymer). The polymer is preferably a copolymer, and the polymer is preferably a fluoropolymer such as a fluoroacrylate polymer. The extraction method comprises the steps of contacting a first composition containing a metal or metalloid to be extracted with a second composition, the second composition being as described above; and then extracting the metal or metalloid from the first composition into the second composition.

  9. [Pharmaceutical applications of supercritical carbon dioxide].

    PubMed

    Delattre, L

    2007-01-01

    The supercritical state of a fluid is intermediate between that of gases and liquids. Supercritical fluids exhibit some solvent power which is tunable in function of pressure and temperature. In the pharmaceutical field, supercritical carbon dioxide is by far the most commonly used fluid; of course, the first applications of supercritical fluids were the replacement of organic solvents in extraction processes; other applications appeared during the last twenty years: supercritical fluids are also used as eluents in chromatography, as solvents in organic synthesis or for the processing of solid dosage forms by drug micronization, by the production of nanospheres, of solid dispersions, of porous polymeric matrices containing different active substances. Supercritical carbon dioxide has been proposed for encapsulating both hydrophilic and hydrophobic drug substances into liposomes as well as for including different active substances into cyclodextrins. There are also future prospects for the use of pressurized carbon dioxide as a sterilizing agent. PMID:17299352

  10. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon...

  11. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon...

  12. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon...

  13. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon...

  14. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon...

  15. Regenerable immobilized aminosilane sorbents for carbon dioxide capture applications

    SciTech Connect

    Gay, McMahan; Choi, Sunho; Jones, Christopher W

    2014-09-16

    A method for the separation of carbon dioxide from ambient air and flue gases is provided wherein a phase separating moiety with a second moiety are simultaneously coupled and bonded onto an inert substrate to create a mixture which is subsequently contacted with flue gases or ambient air. The phase-separating moiety is an amine whereas the second moiety is an aminosilane, or a Group 4 propoxide such as titanium (IV) propoxide (tetrapropyl orthotitanate, C.sub.12H.sub.28O.sub.4Ti). The second moiety makes the phase-separating moiety insoluble in the pores of the inert substrate. The new sorbents have a high carbon dioxide loading capacity and considerable stability over hundreds of cycles. The synthesis method is readily scalable for commercial and industrial production.

  16. The Orbiting Carbon Observatory: NASA's First Dedicated Carbon Dioxide Mission

    NASA Technical Reports Server (NTRS)

    Crisp, D.

    2008-01-01

    The Orbiting Carbon Observatory is scheduled for launch from Vandenberg Air Force Base in California in January 2009. This Earth System Science Pathfinder (ESSP) mission carries and points a single instrument that incorporates 3 high-resolution grating spectrometers designed to measure the absorption of reflected sunlight by near-infrared carbon dioxide (CO2) and molecular oxygen bands. These spectra will be analyzed to retrieve estimates of the column-averaged CO2 dry air mole fraction, X(sub CO2). Pre-flight qualification and calibration tests completed in early 2008 indicate that the instrument will provide high quality X(sub CO2) data. The instrument was integrated into the spacecraft, and the completed Observatory was qualified and tested during the spring and summer of 2008, in preparation for delivery to the launch site in the fall of this year. The Observatory will initially be launched into a 635 km altitude, near-polar orbit. The on-board propulsion system will then raise the orbit to 705 km and insert OCO into the Earth Observing System Afternoon Constellation (A-Train). The first routine science observations are expected about 45 days after launch. Calibrated spectral radiances will be archived starting about 6 months later. An exploratory X(sub CO2) product will be validated and then archived starting about 3 months after that.

  17. Carbon dioxide hydrate and floods on Mars

    NASA Technical Reports Server (NTRS)

    Milton, D. J.

    1974-01-01

    Ground ice on Mars probably consists largely of carbon dioxide hydrate. This hydrate dissociates upon release of pressure at temperatures between 0 and 10 C. The heat capacity of the ground would be sufficient to produce up to 4% (by volume) of water at a rate equal to that at which it can be drained away. Catastrophic dissociation of carbon dioxide hydrate during some past epoch when the near-surface temperature was in this range would have produced chaotic terrain and flood channels.

  18. Global deforestation: contribution to atmospheric carbon dioxide.

    PubMed

    Woodwell, G M; Hobbie, J E; Houghton, R A; Melillo, J M; Moore, B; Peterson, B J; Shaver, G R

    1983-12-01

    A study of effects of terrestrial biota on the amount of carbon dioxide in the atmosphere suggests that the global net release of carbon due to forest clearing between 1860 and 1980 was between 135 x 10(15) and 228 x 10(15) grams. Between 1.8 x 10(15) and 4.7 x 10(15) grams of carbon were released in 1980, of which nearly 80 percent was due to deforestation, principally in the tropics. The annual release of carbon from the biota and soils exceeded the release from fossil fuels until about 1960. Because the biotic release has been and remains much larger than is commonly assumed, the airborne fraction, usually considered to be about 50 percent of the release from fossil fuels, was probably between 22 and 43 percent of the total carbon released in 1980. The increase in carbon dioxide in the atmosphere is thought by some to be increasing the storage of carbon in the earth's remaining forests sufficiently to offset the release from deforestation. The interpretation of the evidence presented here suggests no such effect; deforestation appears to be the dominant biotic effect on atmospheric carbon dioxide. If deforestation increases in proportion to population, the biotic release of carbon will reach 9 x 10(15) grams per year before forests are exhausted early in the next century. The possibilities for limiting the accumulation of carbon dioxide in the atmosphere through reduction in use of fossil fuels and through management of forests may be greater than is commonly assumed. PMID:17747369

  19. Global deforestation: contribution to atmospheric carbon dioxide

    SciTech Connect

    Woodwell, G.M.; Hobbie, J.E.; Houghton, R.A.; Melillo, J.M.; Moore, B.; Peterson, B.J.; Shaver, G.R.

    1983-12-09

    A study of effects of terrestrial biota on the amount of carbon dioxide in the atmosphere suggests that the global net release of carbon due to forest clearing between 1960 and 1980 was between 135 X 10/sup 15/ and 228 X 10/sup 15/ grams. Between 1.8 X 10/sup 15/ and 4.7 X 10/sup 15/ grams of carbon were released in 1980, of which nearly 80 percent was due to deforestation, principally in the tropics. The annual release of carbon from the biota and soils exceeded the release from fossil fuels until about 1960. Because the biotic release has been and remains much larger than is commonly assumed, the airborne fraction, usually considered to be about 50 percent of the releases from fossil fuels, was probably between 22 and 43 percent of the total carbon released in 1980. The increase in carbon dioxide in the atmosphere is thought by some to be increasing the storage of carbon in the earth's remaining forests sufficiently to offset the release from deforestation. The interpretation of the evidence presented here suggests no such effect; deforestation appears to be the dominant biotic effect on atmospheric carbon dioxide. If deforestation increases in proportion to population, the biotic release of carbon will reach 9 X 10/sup 15/ grams per year before forests are exhausted early in the next century. The possibilities for limiting the accumulation of carbon dioxide in the atmosphere through reduction in use of fossil fuels and through management of forests may be greater than is commonly assumed.

  20. Titanium dioxide, single-walled carbon nanotube composites

    DOEpatents

    Yao, Yuan; Li, Gonghu; Gray, Kimberly; Lueptow, Richard M.

    2015-07-14

    The present invention provides titanium dioxide/single-walled carbon nanotube composites (TiO.sub.2/SWCNTs), articles of manufacture, and methods of making and using such composites. In certain embodiments, the present invention provides membrane filters and ceramic articles that are coated with TiO.sub.2/SWCNT composite material. In other embodiments, the present invention provides methods of using TiO.sub.2/SWCNT composite material to purify a sample, such as a water or air sample.

  1. Carbon Dioxide Collection and Purification System for Mars

    NASA Technical Reports Server (NTRS)

    Clark, D. Larry; Trevathan, Joseph R.

    2001-01-01

    One of the most abundant resources available on Mars is the atmosphere. The primary constituent, carbon dioxide, can be used to produce a wide variety of consumables including propellants and breathing air. The residual gases can be used for additional pressurization tasks including supplementing the oxygen partial pressure in human habitats. A system is presented that supplies pure, high-pressure carbon dioxide and a separate stream of residual gases ready for further processing. This power-efficient method freezes the carbon dioxide directly from the atmosphere using a pulse-tube cryocooler. The resulting CO2 mass is later thawed in a closed pressure vessel, resulting in a compact source of liquefied gas at the vapor pressure of the bulk fluid. Results from a demonstration system are presented along with analysis and system scaling factors for implementation at larger scales. Trace gases in the Martian atmosphere challenge the system designer for all carbon dioxide acquisitions concepts. The approximately five percent of other gases build up as local concentrations of CO2 are removed, resulting in diminished performance of the collection process. The presented system takes advantage of this fact and draws the concentrated residual gases away as a useful byproduct. The presented system represents an excelient volume and mass solution for collecting and compressing this valuable Martian resource. Recent advances in pulse-tube cryocooler technology have enabled this concept to be realized in a reliable, low power implementation.

  2. Effects of carbon dioxide on laryngeal receptors

    SciTech Connect

    Anderson, J.W.; Sant'Ambrogio, F.B.; Orani, G.P.; Sant'Ambrogio, G.; Mathew, O.P. )

    1990-02-26

    Carbon dioxide (CO{sub 2}) either stimulates or inhibits laryngeal receptors in the cat. The aim of this study was to correlate the CO{sub 2} response of laryngeal receptors with their response to other known stimuli (i.e. pressure, movement, cold, water and smoke). Single unit action potentials were recorded from fibers in the superior laryngeal nerve of 5 anesthetized, spontaneously breathing dogs together with CO{sub 2} concentration, esophageal and subglottic pressure. Constant streams of warm, humidified air or 10% CO{sub 2} in O{sub 2} were passed through the functionally isolated upper airway for 60 s. Eight of 13 randomly firing or silent receptors were stimulated by CO{sub 2} (from 0.4{plus minus}0.1 to 1.8{plus minus}0.4 imp.s). These non-respiratory-modulated receptors were more strongly stimulated by solutions lacking Cl{sup {minus}} and/or cigarette smoke. Six of 21 respiratory modulated receptors (responding to pressure and/or laryngeal motion) were either inhibited or stimulated by CO{sub 2}. Our results show that no laryngeal receptor responds only to CO{sub 2}. Silent or randomly active receptors were stimulated most often by CO{sub 2} consistent with the reflex effect of CO{sub 2} in the larynx.

  3. Carbon Dioxide Angiography: Scientific Principles and Practice

    PubMed Central

    Cho, Kyung Jae

    2015-01-01

    Carbon dioxide (CO2) is a colorless, odorless gas which occurs naturally in the atmosphere and human body. With the advent of digital subtraction angiography, the gas has been used as a safe and useful alternative contrast agent in both arteriography and venography. Because of its lack of renal toxicity and allergic potential, CO2 is a preferred contrast agent in patients with renal failure or contrast allergy, and particularly in patients who require large volumes of contrast medium for complex endovascular procedures. Understanding of the unique physical properties of CO2 (high solubility, low viscosity, buoyancy, and compressibility) is essential in obtaining a successful CO2 angiogram and in guiding endovascular intervention. Unlike iodinated contrast material, CO2 displaces the blood and produces a negative contrast for digital subtraction imaging. Indications for use of CO2 as a contrast agent include: aortography and runoff, detection of bleeding, renal transplant arteriography, portal vein visualization with wedged hepatic venous injection, venography, arterial and venous interventions, and endovascular aneurysm repair. CO2 should not be used in the thoracic aorta, the coronary artery, and cerebral circulation. Exploitation of CO2 properties, avoidance of air contamination and facile catheterization technique are important to the safe and effective performance of CO2 angiography and CO2-guided endovascular intervention. PMID:26509137

  4. Carbon Dioxide Angiography: Scientific Principles and Practice.

    PubMed

    Cho, Kyung Jae

    2015-09-01

    Carbon dioxide (CO2) is a colorless, odorless gas which occurs naturally in the atmosphere and human body. With the advent of digital subtraction angiography, the gas has been used as a safe and useful alternative contrast agent in both arteriography and venography. Because of its lack of renal toxicity and allergic potential, CO2 is a preferred contrast agent in patients with renal failure or contrast allergy, and particularly in patients who require large volumes of contrast medium for complex endovascular procedures. Understanding of the unique physical properties of CO2 (high solubility, low viscosity, buoyancy, and compressibility) is essential in obtaining a successful CO2 angiogram and in guiding endovascular intervention. Unlike iodinated contrast material, CO2 displaces the blood and produces a negative contrast for digital subtraction imaging. Indications for use of CO2 as a contrast agent include: aortography and runoff, detection of bleeding, renal transplant arteriography, portal vein visualization with wedged hepatic venous injection, venography, arterial and venous interventions, and endovascular aneurysm repair. CO2 should not be used in the thoracic aorta, the coronary artery, and cerebral circulation. Exploitation of CO2 properties, avoidance of air contamination and facile catheterization technique are important to the safe and effective performance of CO2 angiography and CO2-guided endovascular intervention. PMID:26509137

  5. Euthanasia of neonatal mice with carbon dioxide

    USGS Publications Warehouse

    Pritchett, K.; Corrow, D.; Stockwell, J.; Smith, A.

    2005-01-01

    Exposure to carbon dioxide (CO2) is the most prevalent method used to euthanize rodents in biomedical research. The purpose of this study was to determine the time of CO2 exposure required to euthanize neonatal mice (0 to 10 days old). Multiple groups of mice were exposed to 100% CO 2 for time periods between 5 and 60 min. Mice were placed in room air for 10 or 20 min after CO2 exposure, to allow for the chance of recovery. If mice recovered at one time point, a longer exposure was examined. Inbred and outbred mice were compared. Results of the study indicated that time to death varied with the age of the animals and could be as long as 50 min on the day of birth and differed between inbred and outbred mice. Institutions euthanizing neonatal mice with CO2 may wish to adjust their CO 2 exposure time periods according the age of the mice and their genetic background. Copyright 2005 by the American Association for Laboratory Animal Science.

  6. Carbon dioxide dynamics in an artificial ecosystem

    NASA Astrophysics Data System (ADS)

    Hu, Enzhu; Hu, Dawei; Tong, Ling; Li, Ming; Fu, Yuming; He, Wenting; Liu, Hong

    An experimental artificial ecosystem was established as a tool to understand the behavior of closed ecosystem and to develop the technology for a future bioregenerative life support system for lunar or planetary exploration. Total effective volume of the system is 0.7 m3 . It consists of a higher plant chamber, an animal chamber and a photo-bioreactor which cultivated lettuce (Lactuca sativa L.), silkworm (Bombyx Mori L.) and microalgae (Chlorella), respectively. For uniform and sustained observations, lettuce and silkworms was cultivated using sequential cultivation method, and microalgae using continuous culture. Four researchers took turns breathing the system air through a tube for brief periods every few hours. A mathematic model, simulating the carbon dioxide dynamics was developed. The main biological parameters concerning photosynthesis of lettuce and microalgae, respiration of silkworms and human were validated by the experimental data. The model described the respiratory relationship between autotrophic and heterotrophic compartments. A control strategy was proposed as a tool for the atmosphere management of the artificial ecosystem.

  7. Organic syntheses employing supercritical carbon dioxide as a reaction solvent

    NASA Technical Reports Server (NTRS)

    Barstow, Leon E. (Inventor); Ward, Glen D. (Inventor); Bier, Milan (Inventor)

    1993-01-01

    Chemical reactions are readily carried out using supercritical carbon dioxide as the reaction medium. Supercritical carbon dioxide is of special value as a reaction medium in reactions for synthesizing polypeptides, for sequencing polypeptides, or for amino acid analysis.

  8. Organic syntheses employing supercritical carbon dioxide as a reaction solvent

    NASA Technical Reports Server (NTRS)

    Barstow, Leon E. (Inventor); Ward, Glen D. (Inventor); Bier, Milan (Inventor)

    1991-01-01

    Chemical reactions are readily carried out using supercritical carbon dioxide as the reaction medium. Supercritical carbon dioxide is of special value as a reaction medium in reactions for synthesizing polypeptides, for sequencing polypeptides, or for amino acid analysis.

  9. International Space Station Carbon Dioxide Removal Assembly Testing

    NASA Technical Reports Server (NTRS)

    Knox, James C.

    2000-01-01

    Performance testing of the International Space Station Carbon Dioxide Removal Assembly flight hardware in the United States Laboratory during 1999 is described. The CDRA exceeded carbon dioxide performance specifications and operated flawlessly. Data from this test is presented.

  10. Gas diffusion cell removes carbon dioxide from occupied airtight enclosures

    NASA Technical Reports Server (NTRS)

    1964-01-01

    Small, lightweight permeable cell package separates and removes carbon dioxide from respiratory gas mixtures. The cell is regenerative while chemically inert in the presence of carbon dioxide so that only adsorption takes place.

  11. Use of carbon dioxide in the chemical synthesis technologies, plasma gasification and carbon production

    NASA Astrophysics Data System (ADS)

    Rutberg, Ph G.; Kuznetsov, V. A.; Bratsev, A. N.; Popov, V. E.; Shtengel', S. V.; Ufimtsev, A. A.

    2011-03-01

    The modern electric power sector is based on burning of carbonaceous substances (coal, oil, natural gas, etc.). Large power stations are powerful local sources of carbon dioxide. Inconstancy of the electric power demand leads to increase in CO2 specific emissions, as the output power is basically higher than required one by the power network. One of promising ways of increase of operating efficiency of power stations is use of surpluses of the generated electric power in plasma technologies. The paper deals with the opportunity to use the plasma technologies in processes of methanol and methane production from carbon dioxide. Comparison of ranges of key parameters of plasma gasification of wood by air, carbon dioxide, and steam is presented. Also, use of CO2 for pure carbon production is examined.

  12. Discussion of Refrigeration Cycle Using Carbon Dioxide as Refrigerant

    NASA Astrophysics Data System (ADS)

    Ji, Amin; Sun, Miming; Li, Jie; Yin, Gang; Cheng, Keyong; Zhen, Bing; Sun, Ying

    Nowadays, the problem of the environment goes worse, it urges people to research and study new energy-saving and environment-friendly refrigerants, such as carbon dioxide, at present, people do research on carbon dioxide at home and abroad. This paper introduces the property of carbon dioxide as a refrigerant, sums up and analyses carbon dioxide refrigeration cycles, and points out the development and research direction in the future.

  13. Rising atmospheric carbon dioxide and crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The increase in carbon dioxide concentration in the earth's atmosphere and its potential effect on atmospheric temperature is a major concern. Changes in global environment will have major effects for natural and agricultural ecosystems. Plants have been directly affected by rising atmospheric CO2...

  14. Urban carbon dioxide in Portland, Oregon

    NASA Astrophysics Data System (ADS)

    Bostrom, G. A.; Brooks, M.; Rice, A. L.

    2010-12-01

    Ambient concentrations of atmospheric carbon dioxide (CO2) are reported for the Portland, Oregon (USA) metropolitan region since late July, 2009. Three stationary locations were established: a downtown location on the campus of Portland State University; a residential site in southeast Portland; and a rural station on Sauvie Island, located ~30km northwest of Portland in the Columbia River Gorge. Continuous measurements of CO2 at the sites average 400-410ppm and show considerable variability due to CO2 sources, sinks and meteorological drivers of ventilation. Within this variability, a marked 20-30ppm diurnal cycle is observed due to photosynthetic activity and variations in the planetary boundary layer. In-city CO2 concentrations are on average enhanced by 5-6ppm over the Sauvie Island site during upgorge wind conditions, a difference which is greatest in the afternoon. Measurements of the 13C/12C ratio of CO2 in downtown Portland are significantly depleted in 13C relative to 12C compared with background air and suggest that regional CO2 is dominated by petroleum sources (70-80%). High degrees of relationship between CO2 variability and primary air pollutants CO and NO (r2=0.70 to 0.80), measured by the Oregon Department of Environmental Quality at the Southeast Portland location, corroborate this finding and illustrate the importance of traffic emissions on elevated ambient CO2 concentrations. In addition to CO2 at the fixed sites, measurements of street-level CO2 concentrations were obtained using a mobile instrument mounted in a bike trailer. Results from these field data show relatively homogenous CO2 concentrations throughout residential Portland neighborhoods with significant enhancements in CO2 on busy roadways or near areas of traffic congestion.

  15. Catalyst cartridge for carbon dioxide reduction unit

    NASA Technical Reports Server (NTRS)

    Holmes, R. F. (Inventor)

    1973-01-01

    A catalyst cartridge, for use in a carbon dioxide reducing apparatus in a life support system for space vehicles, is described. The catalyst cartridge includes an inner perforated metal wall, an outer perforated wall space outwardly from the inner wall, a base plate closing one end of the cartridge, and a cover plate closing the other end of the cartridge. The cover plate has a central aperture through which a supply line with a heater feeds a gaseous reaction mixture comprising hydrogen and carbon dioxide at a temperature from about 1000 to about 1400 F. The outer surfaces of the internal wall and the inner surfaces of the outer wall are lined with a ceramic fiber batting material of sufficient thickness to prevent carbon formed in the reaction from passing through it. The portion of the surfaces of the base and cover plates defined within the inner and outer walls are also lined with ceramic batting. The heated reaction mixture passes outwardly through the inner perforated wall and ceramic batting and over the catalyst. The solid carbon product formes is retained within the enclosure containing the catalyst. The solid carbon product formed is retained within the enclosure containing the catalyst. The water vapor and unreacted carbon dioxide and any intermediate products pass through the perforations of the outer wall.

  16. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure...

  17. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to its introduction into service and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:...

  18. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  19. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  20. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Chemical; carbon dioxide. 313.5... INSPECTION AND CERTIFICATION HUMANE SLAUGHTER OF LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling in...

  1. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure...

  2. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to its introduction into service and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:...

  3. 21 CFR 868.5310 - Carbon dioxide absorber.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  4. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of...

  5. 21 CFR 868.5310 - Carbon dioxide absorber.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  6. 21 CFR 868.5310 - Carbon dioxide absorber.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  7. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Chemical; carbon dioxide. 313.5... INSPECTION AND CERTIFICATION HUMANE SLAUGHTER OF LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling in...

  8. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY ALCOHOL WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted...

  9. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  10. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www... 49 Transportation 3 2013-10-01 2013-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1... Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated...

  11. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY ALCOHOL WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted...

  12. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of...

  13. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to its introduction into service and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:...

  14. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Chemical; carbon dioxide. 313.5... INSPECTION AND CERTIFICATION HUMANE SLAUGHTER OF LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling in...

  15. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure...

  16. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www... 49 Transportation 3 2014-10-01 2014-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1... Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated...

  17. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565... Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected must be equal to the gross volume...

  18. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... carbon dioxide. 26.52 Section 26.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine;...

  19. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted...

  20. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  1. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of...

  2. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted...

  3. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... carbon dioxide. 26.52 Section 26.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine;...

  4. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to its introduction into service and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:...

  5. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of...

  6. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565... Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected must be equal to the gross volume...

  7. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www... 49 Transportation 3 2011-10-01 2011-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1... Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated...

  8. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... carbon dioxide. 26.52 Section 26.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine;...

  9. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of...

  10. 21 CFR 868.5310 - Carbon dioxide absorber.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  11. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to its introduction into service and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:...

  12. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure...

  13. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  14. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www... 49 Transportation 3 2012-10-01 2012-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1... Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated...

  15. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... carbon dioxide. 26.52 Section 26.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine;...

  16. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565... Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected must be equal to the gross volume...

  17. 21 CFR 868.5310 - Carbon dioxide absorber.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  18. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Chemical; carbon dioxide. 313.5... INSPECTION AND CERTIFICATION HUMANE SLAUGHTER OF LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling in...

  19. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Chemical; carbon dioxide. 313.5... INSPECTION AND CERTIFICATION HUMANE SLAUGHTER OF LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling in...

  20. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted...

  1. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure...

  2. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565... Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected must be equal to the gross volume...

  3. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... carbon dioxide. 26.52 Section 26.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine;...

  4. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565... Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected must be equal to the gross volume...

  5. Vegetation Response to Carbon Dioxide and Climate: Data from the Carbon Dioxide Information Analysis Center (CDIAC)

    DOE Data Explorer

    CDIAC products are indexed and searchable through a customized interface powered by ORNL's Mercury search engine. Products include numeric data packages, publications, trend data, atlases, and models and can be searched for by subject area, keywords, authors, product numbers, time periods, collection sites, spatial references, etc. Some of the collections may also be included in the CDIAC publication Trends Online: A Compendium of Global Change Data. Most data sets, many with numerous data files, are free to download from CDIAC's ftp area. Information related to vegetation response to carbon dioxide and climate includes: • Area and Carbon Content of Sphagnum Since Last Glacial Maximum (2002) (Trends Online) • TDE Model Intercomparison Project Data Archive • Presentations and abstracts from the recent DOE Terrestrial Science Team Meeting (Argonne National Laboratory, October 29-31, 2001) • FACE (Free-Air CO2 Enrichment) • Walker Branch Throughfall Displacement Experiment Data Report: Site Characterization, System Performance, Weather, Species Composition, and Growth (2001) • Bibliography on CO2 Effects on Vegetation and Ecosystems: 1990-1999 Literature (2000) • Direct effects of atmospheric CO2 enrichment on plants and ecosystems: An updated bibliographic data base (1994) • A Database of Herbaceous Vegetation Responses to Elevated Atmospheric CO2 (1999) • A Database of Woody Vegetation Responses to Elevated Atmospheric CO2 (1999) • Forest Responses to Anthropogenic Stress (FORAST) Database (1995) • Effects of CO2 and Nitrogen Fertilization on Growth and Nutrient Content of Juvenile Ponderosa Pine (1998) • Carbon Dioxide Enrichment: Data on the Response of Cotton to Varying CO2Irrigation, and Nitrogen (1992) • Growth and Chemical Responses to CO2 Enrichment Virginia Pine Pinus Virginiana Mill.(1985)

  6. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Carbon monoxide and carbon dioxide... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers....

  7. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Carbon monoxide and carbon dioxide... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers....

  8. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Carbon monoxide and carbon dioxide... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers....

  9. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon monoxide and carbon dioxide... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers....

  10. Hidden carbon dioxide on Mars

    NASA Astrophysics Data System (ADS)

    Haberle, M. R.

    1985-12-01

    A recent proposal that much of the outgassed CO2 on Mars is tied up in the planet's crust in the form of carbonate mineral is discussed. According to this hypothesis, carbonate formation on Mars continued after open bodies of liquid water became unstable. A consequence of the hypothesis is that, in the absence of a recycling mechanism for CO2, the surface pressure on Mars will monotonically decrease until it reaches the minimum atmospheric overburden pressure required for liquid water to form. The theory explains Mars' low surface pressure, and also implies that the climate of Mars has evolved linearly over geologic time, rather than cyclically.

  11. Hidden carbon dioxide on Mars

    NASA Technical Reports Server (NTRS)

    Haberle, R. M.

    1985-01-01

    A recent proposal that much of the outgassed CO2 on Mars is tied up in the planet's crust in the form of carbonate mineral is discussed. According to this hypothesis, carbonate formation on Mars continued after open bodies of liquid water became unstable. A consequence of the hypothesis is that, in the absence of a recycling mechanism for CO2, the surface pressure on Mars will monotonically decrease until it reaches the minimum atmospheric overburden pressure required for liquid water to form. The theory explains Mars' low surface pressure, and also implies that the climate of Mars has evolved linearly over geologic time, rather than cyclically.

  12. The Headache of Carbon Dioxide Exposures

    NASA Technical Reports Server (NTRS)

    James, John T.

    2007-01-01

    Carbon dioxide (CO2), a natural product of human metabolism, accumulates quickly in sealed environments when humans are present, and can induce headaches, among other symptoms. Major resources are expended to control CO2 levels to concentrations that are tolerable to the crews of spacecraft and submersible craft. It is not practical to control CO2 levels to those found in the ambient environment on earth. As NASA looks ahead to long-duration missions conducted far from earth, difficult issues arise related to the management and effects of human exposure to CO2. One is the problem of pockets of CO2 in the habitat caused by excess generation of the gas in one location without a mechanism to purge the area with fresh air. This results in the crew rebreathing CO2 from their exhaled breath, exposing them to a much higher concentration of CO2 than whole-module measurements would suggest. Another issue is the potential increased sensitivity to CO2 in microgravity. For example, based on anecdotal information, it appears that space crews may be more susceptible than submarine crews to some of the subtle, yet adverse effects of CO2 exposure. Another issue, not unique to spaceflight, is the possibility of inter-individual differences in the susceptibility of crewmembers to CO2 exposure. Again, anecdotal reports from the International Space Station (ISS) crews suggest that certain individuals may experience a greater susceptibility. The implications associated with these issues are extremely important as NASA sets CO2 exposure limits that protect the crew from this compound s subtle adverse effects, without causing an unwarranted expenditure of resources to scrub CO2 from the habitat atmosphere.

  13. Carbon dioxide sequestration by direct mineral carbonation with carbonic acid

    SciTech Connect

    O'Connor, William K.; Dahlin, David C.; Nilsen, David N.; Walters, Richard P.; Turner, Paul C.

    2000-01-01

    The Albany Research Center (ARC) of the U.S. Dept. of Energy (DOE) has been conducting a series of mineral carbonation tests at its Albany, Oregon, facility over the past 2 years as part of a Mineral Carbonation Study Program within the DOE. Other participants in this Program include the Los Alamos National Laboratory, Arizona State University, Science Applications International Corporation, and the DOE National Energy Technology Laboratory. The ARC tests have focused on ex-situ mineral carbonation in an aqueous system. The process developed at ARC utilizes a slurry of water mixed with a magnesium silicate mineral, olivine [forsterite end member (Mg2SiO4)], or serpentine [Mg3Si2O5(OH)4]. This slurry is reacted with supercritical carbon dioxide (CO2) to produce magnesite (MgCO3). The CO2 is dissolved in water to form carbonic acid (H2CO3), which dissociates to H+ and HCO3 -. The H+ reacts with the mineral, liberating Mg2+ cations which react with the bicarbonate to form the solid carbonate. The process is designed to simulate the natural serpentinization reaction of ultramafic minerals, and for this reason, these results may also be applicable to in-situ geological sequestration regimes. Results of the baseline tests, conducted on ground products of the natural minerals, have been encouraging. Tests conducted at ambient temperature (22 C) and subcritical CO2 pressures (below 73 atm) resulted in very slow conversion to the carbonate. However, when elevated temperatures and pressures are utilized, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant reaction occurs within much shorter reaction times. Extent of reaction, as measured by the stoichiometric conversion of the silicate mineral (olivine) to the carbonate, is roughly 90% within 24 hours, using distilled water, and a reaction temperature of 185?C and a partial pressure of CO2 (PCO2) of 115 atm. Recent tests using a bicarbonate solution, under identical reaction

  14. Carbon dioxide sequestration by direct mineral carbonation with carbonic acid

    SciTech Connect

    O'Connor, W.K.; Dahlin, D.C.; Nilsen, D.N.; Walters, R.P.; Turner, P.C.

    2000-07-01

    The Albany Research Center (ARC) of the US Department of Energy (DOE) has been conducting a series of mineral carbonation tests at its Albany, Oregon, facility over the past 2 years as part of a Mineral Carbonation Study Program within the DOE. The ARC tests have focused on ex-situ mineral carbonation in an aqueous system. The process developed at ARC utilizes a slurry of water mixed with a magnesium silicate mineral, olivine [forsterite and member (mg{sub 2}SiO{sub 4})], or serpentine [Mg{sub 3}Si{sub 2}O{sub 5}(OH){sub 4}]. This slurry is reacted with supercritical carbon dioxide (CO{sub 2}) to produce magnesite (MgCO{sub 3}). The CO{sub 2} is dissolved in water to form carbonic acid (H{sub 2}CO{sub 3}), which dissociates to H{sup +} and HCO{sub 3}{sup {minus}}. The H{sup +} reacts with the mineral, liberating Mg{sup 2+} cations which react with the bicarbonate to form the solid carbonate. The process is designed to simulate the natural serpentinization reaction of ultramafic minerals, and for this reason, these results may also be applicable to in-situ geological sequestration regimes. Results of the baseline tests, conducted on ground products of the natural minerals, have been encouraging. Tests conducted at ambient temperature (22 C) and subcritical CO{sub 2} pressures (below 73 atm) resulted in very slow conversion to the carbonate. However, when elevated temperatures and pressures are utilized, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant reaction occurs within much shorter reaction times. Extent of reaction, as measured by the stoichiometric conversion of the silicate mineral (olivine) to the carbonate, is roughly 90% within 24 hours, using distilled water, and a reaction temperature of 185 C and a partial pressure of CO{sub 2} (P{sub CO{sub 2}}) of 115 atm. Recent tests using a bicarbonate solution, under identical reaction conditions, have achieved roughly 83% conversion of heat treated serpentine

  15. Climate impact of increasing atmospheric carbon dioxide.

    PubMed

    Hansen, J; Johnson, D; Lacis, A; Lebedeff, S; Lee, P; Rind, D; Russell, G

    1981-08-28

    The global temperature rose by 0.2 degrees C between the middle 1960's and 1980, yielding a warming of 0.4 degrees C in the past century. This temperature increase is consistent with the calculated greenhouse effect due to measured increases of atmospheric carbon dioxide. Variations of volcanic aerosols and possibly solar luminosity appear to be primary causes of observed fluctuations about the mean trend of increasing temperature. It is shown that the anthropogenic carbon dioxide warming should emerge from the noise level of natural climate variability by the end of the century, and there is a high probability of warming in the 1980's. Potential effects on climate in the 21st century include the creation of drought-prone regions in North America and central Asia as part of a shifting of climatic zones, erosion of the West Antarctic ice sheet with a consequent worldwide rise in sea level, and opening of the fabled Northwest Passage. PMID:17789014

  16. Recycling technology of emitted carbon dioxide

    SciTech Connect

    Arakawa, Hironori

    1993-12-31

    Ways to halt global warming are being discussed worldwide. Global warming is an energy problem which is mainly attributed to the large volumes of carbon dioxide (CO{sub 2}) released into the atmosphere from the rapid increase in energy consumption since the Industrial Revolution. The basic solution to the problem, therefore, is to cut consumption of fossil fuels. To this end, it is important to promote energy conservation by improving the fuel efficiency of machines, as well as shift to energy sources that do not emit carbon dioxide and develop related technologies. If current trends in economic growth continue in the devloping world as well as the developed countries, there can be no doubt that energy consumption will increase. Therefore, alongside energy conservation and the development of alternative energies, the importance of technologies to recover and fix CO{sub 2} will increase in the fight against global warming.

  17. Carbon dioxide in vascular imaging and intervention.

    PubMed

    Yang, X; Manninen, H; Soimakallio, S

    1995-07-01

    Angiography with iodinated contrast agents is bound up with the risks of contrast-induced nephrotoxicity and hypersensitivity, which led to the idea of using carbon dioxide (CO2) gas as a negative contrast medium to eliminate these drawbacks. During the last decade, refinements and experiences have proved carbon dioxide digital subtraction angiography (CO2-DSA) to be an accurate, safe, and clinically promising vascular imaging modality, with the advantages of no hypersensitivity and no nephrotoxicity as well as minimal patient discomfort. In this article, we have reviewed the history, physical and chemical aspects, techniques, and pathophysiologic changes with the use of CO2-DSA as well as some clinical trials. Applications of CO2 gas in vascular interventions and other imagings, and the advantages and limitations of using CO2 gas in DSA are also discussed. PMID:7619608

  18. Sequestering ADM ethanol plant carbon dioxide

    USGS Publications Warehouse

    Finley, R.J.; Riddle, D.

    2008-01-01

    Archer Daniels Midland Co. (ADM) and the Illinois State Geological Survey (ISGS) are collaborating on a project in confirming that a rock formation can store carbon dioxide from the plant in its pores. The project aimed to sequester the gas underground permanently to minimize release of the greenhouse gas into the atmosphere. It is also designed to store one million tons of carbon dioxide over a three-year period. The project is worth $84.3M, funded by $66.7M from the US Department Energy, supplemented by co-funding from ADM and other corporate and state resources. The project will start drilling of wells to an expected depth over 6500 feet into the Mount Simon Sandstone formation.

  19. Asymmetric catalytic transformations in supercritical carbon dioxide

    SciTech Connect

    Feng, Shaoguang; Tumas, W.; Gross, M.F.; Burk, M.J.

    1996-12-31

    Supercritical carbon dioxide can be a useful environmentally benign solvent for a wide range of catalytic reactions. We have been exploring the utility of supercritical carbon dioxide as a reaction medium for catalytic asymmetric transformations. We will present results on the asymmetric hydrogenation of prochiral olefins, ketones, and unsaturated acids by Rh and Ru catalysts containing chiral phosphine ligands using hydrogen or hydrogen transfer agents. We have found that asymmetric catalytic hydrogenation reactions of enamide esters work as well or better in CO{sub 2} than in conventional solvents. We have been able to effect high conversions and ee`s using hydrogen transfer systems such as HCOOH/NEt{sub 3}, We will discuss temperature, pressure and solvent density effects on selectivity and reactivity. Kinetic studies will also be presented in order to understand the enhanced enantioselectivity that we observed in SC CO{sub 2}.

  20. Modeling carbon dioxide, pH, and un-ionized ammonia relationships in serial reuse systems

    USGS Publications Warehouse

    Colt, J.; Watten, B.; Rust, M.

    2009-01-01

    In serial reuse systems, excretion of metabolic carbon dioxide has a significant impact on ambient pH, carbon dioxide, and un-ionized ammonia concentrations. This impact depends strongly on alkalinity, water flow rate, feeding rate, and loss of carbon dioxide to the atmosphere. A reduction in pH from metabolic carbon dioxide can significantly reduce the un-ionized ammonia concentration and increase the carbon dioxide concentrations compared to those parameters computed from influent pH. The ability to accurately predict pH in serial reuse systems is critical to their design and effective operation. A trial and error solution to the alkalinity-pH system was used to estimate important water quality parameters in serial reuse systems. Transfer of oxygen and carbon dioxide across the air-water interface, at overflow weirs, and impacts of substrate-attached algae and suspended bacteria were modeled. Gas transfer at the weirs was much greater than transfer across the air-water boundary. This simulation model can rapidly estimate influent and effluent concentrations of dissolved oxygen, carbon dioxide, and un-ionized ammonia as a function of water temperature, elevation, water flow, and weir type. The accuracy of the estimates strongly depends on assumed pollutional loading rates and gas transfer at the weirs. The current simulation model is based on mean daily loading rates; the impacts of daily variation loading rates are discussed. Copies of the source code and executable program are available free of charge.

  1. Carbon Dioxide Laser Fiber Optics In Endoscopy

    NASA Astrophysics Data System (ADS)

    Fuller, Terry A.

    1982-12-01

    Carbon dioxide laser surgery has been limited to a great extent to surgical application on the integument and accessible cavities such as the cervix, vagina, oral cavities, etc. This limitation has been due to the rigid delivery systems available to all carbon dioxide lasers. Articulating arms (series of hollow tubes connected by articulating mirrors) have provided an effective means of delivery of laser energy to the patient as long as the lesion was within the direct line of sight. Even direct line-of-sight applications were restricted to physical dimension of the articulating arm or associated hand probes, manipulators and hollow tubes. The many attempts at providing straight endoscopic systems to the laser only stressed the need for a fiber optic capable of carrying the carbon dioxide laser wavelength. Rectangular and circular hollow metal waveguides, hollow dielectric waveguides have proven ineffective to the stringent requirements of a flexible surgical delivery system. One large diameter (1 cm) fiber optic delivery system, incorporates a toxic thalliumAbased fiber optic material. The device is an effective alternative to an articulating arm for external or conventional laser surgery, but is too large and stiff to use as a flexible endoscopic tool. The author describes the first highly flexible inexpensive series of fiber optic systems suitable for either conventional or endoscopic carbon dioxide laser surgery. One system (IRFLEX 3) has been manufactured by Medlase, Inc. for surgical uses capable of delivering 2000w, 100 mJ pulsed energy and 15w continuous wave. The system diameter is 0.035 inches in diameter. Surgically suitable fibers as small as 120 um have been manufactured. Other fibers (IRFLEX 142,447) have a variety of transmission characteristics, bend radii, etc.

  2. Carbon dioxide laser stomaplasty for tracheostomal stenosis.

    PubMed

    Sani, A

    1998-05-01

    A method of treating tracheostomal stenosis post-laryngectomy is described. The carbon dioxide (CO2) laser is used to fashion and ablate two triangular areas lateral to the stenosed stoma to provide an immediate enlarged stoma for comfortable breathing. This simple procedure is done under local anaesthesia, is almost bloodless, safe and takes just 10 minutes. Over the last five years eight patients underwent this procedure and seven had a satisfactory stoma without the need to use a tracheostomy tube. PMID:9747477

  3. Electrochemical carbon dioxide concentrator: Math model

    NASA Technical Reports Server (NTRS)

    Marshall, R. D.; Schubert, F. H.; Carlson, J. N.

    1973-01-01

    A steady state computer simulation model of an Electrochemical Depolarized Carbon Dioxide Concentrator (EDC) has been developed. The mathematical model combines EDC heat and mass balance equations with empirical correlations derived from experimental data to describe EDC performance as a function of the operating parameters involved. The model is capable of accurately predicting performance over EDC operating ranges. Model simulation results agree with the experimental data obtained over the prediction range.

  4. Carbon dioxide makes heat therapy work

    SciTech Connect

    Sherman, H.

    1987-01-01

    Scientists can now propagate healthy blueberry and raspberry plants from virus-infected stock by treating it with heat and carbon dioxide. Plants are grown at 100/sup 0/F, which makes them develop faster than the virus can spread. Then cuttings are taken of the new growth - less than an inch long - and grown into full-sized, virus-free plants. But in this race to outdistance the virus, some plant species are not able to take the heat. Some even die. Chemical reactions double for every 14/sup 0/F rise in temperature. So, if you try to grow a plant at 100/sup 0/F that was originally growing at 86/sup 0/F, it will double its respiration rate. Adding carbon dioxide increases the rate of photosynthesis in plants, which increases the plant's food reserves. What carbon dioxide does to allow some plants to grow at temperatures at which they would otherwise not survive and it allows other plants to grow for longer periods at 100/sup 0/F. One problem with the process, says Converse, is that the longer plants are exposed to heat the greater the mutation rate. So, resulting clones should be closely examined for trueness to horticultural type.

  5. Carbon dioxide embolism during laparoscopic sleeve gastrectomy

    PubMed Central

    Zikry, Amir Abu; DeSousa, Kalindi; Alanezi, Khaled H

    2011-01-01

    Bariatric restrictive and malabsorptive operations are being carried out in most countries laparoscopically. Carbon dioxide or gas embolism has never been reported in obese patients undergoing bariatric surgery. We report a case of carbon dioxide embolism during laparoscopic sleeve gastrectomy (LSG) in a young super obese female patient. Early diagnosis and successful management of this complication are discussed. An 18-year-old super obese female patient with enlarged fatty liver underwent LSG under general anesthesia. During initial intra-peritoneal insufflation with CO2 at high flows through upper left quadrant of the abdomen, she had precipitous fall of end-tidal CO2 and SaO2 % accompanied with tachycardia. Early suspicion led to stoppage of further insufflation. Clinical parameters were stabilized after almost 30 min, while the blood gas analysis was restored to normal levels after 1 h. The area of gas entrainment on the damaged liver was recognized by the surgeon and sealed and the surgery was successfully carried out uneventfully. Like any other laparoscopic surgery, carbon dioxide embolism can occur during bariatric laparoscopic surgery also. Caution should be exercised when Veress needle is inserted through upper left quadrant of the abdomen in patients with enlarged liver. A high degree of suspicion and prompt collaboration between the surgeon and anesthetist can lead to complete recovery from this potentially fatal complication. PMID:21772696

  6. Extraction of furfural with carbon dioxide

    SciTech Connect

    Gamse, T.; Marr, R.; Froeschl, F.; Siebenhofer, M.

    1997-01-01

    A new approach to separate furfural from aqueous waste has been investigated. Recovery of furfural and acetic acid from aqueous effluents of a paper mill has successfully been applied on an industrial scale since 1981. The process is based on the extraction of furfural and acetic acid by the solvent trooctylphosphineoxide (TOPO). Common extraction of both substances may cause the formation of resin residues. Improvement was expected by selective extraction of furfural with chlorinated hydrocarbons, but ecological reasons stopped further development of this project. The current investigation is centered in the evaluation of extraction of furfural by supercritical carbon dioxide. The influence of temperature and pressure on the extraction properties has been worked out. The investigation has considered the multi-component system furfural-acetic acid-water-carbon dioxide. Solubility of furfural in liquid and supercritical carbon dioxide has been measured, and equilibrium data for the ternary system furfural-water-CO{sub 2} as well as for the quaternary system furfural-acetic acid-water-CO{sub 2} have been determined. A high-pressure extraction column has been used for evaluation of mass transfer rates.

  7. Carbon dioxide in Arctic and subarctic regions

    SciTech Connect

    Gosink, T. A.; Kelley, J. J.

    1981-03-01

    A three year research project was presented that would define the role of the Arctic ocean, sea ice, tundra, taiga, high latitude ponds and lakes and polar anthropogenic activity on the carbon dioxide content of the atmosphere. Due to the large physical and geographical differences between the two polar regions, a comparison of CO/sub 2/ source and sink strengths of the two areas was proposed. Research opportunities during the first year, particularly those aboard the Swedish icebreaker, YMER, provided additional confirmatory data about the natural source and sink strengths for carbon dioxide in the Arctic regions. As a result, the hypothesis that these natural sources and sinks are strong enough to significantly affect global atmospheric carbon dioxide levels is considerably strengthened. Based on the available data we calculate that the whole Arctic region is a net annual sink for about 1.1 x 10/sup 15/ g of CO/sub 2/, or the equivalent of about 5% of the annual anthropogenic input into the atmosphere. For the second year of this research effort, research on the seasonal sources and sinks of CO/sub 2/ in the Arctic will be continued. Particular attention will be paid to the seasonal sea ice zones during the freeze and thaw periods, and the tundra-taiga regions, also during the freeze and thaw periods.

  8. Elevated atmospheric carbon dioxide increases soil carbon

    SciTech Connect

    Norby, Richard J; Jastrow, Julie D; Miller, Michael R; Matamala, Roser; Boutton, Thomas W; Rice, Charles W; Owensby, Clenton E

    2005-01-01

    In a study funded by the U.S. Department of Energy's Office of Science, researchers from Argonne and Oak Ridge National Laboratories and Kansas State and Texas A&M Universities evaluated the collective results of earlier studies by using a statistical procedure called meta-analysis. They found that on average elevated CO2 increased soil carbon by 5.6 percent over a two to nine year period. They also measured comparable increases in soil carbon for Tennessee deciduous forest and Kansas grassland after five to eight years of experimental exposure to elevated CO2.

  9. Carbon dioxide reduction by the Bosch process

    NASA Technical Reports Server (NTRS)

    Manning, M. P.; Reid, R. C.

    1975-01-01

    Prototype units for carrying out the reduction of carbon dioxide to elementary carbon have been built and operated successfully. In some cases, however, startup difficulties have been reported. Moreover, the recycle reactor product has been reported to contain only small amounts of water and undesirably high yields of methane. This paper presents the results of the first phase of an experimental study that was carried out to define the mechanisms occurring in the reduction process. Conclusions are drawn and possible modifications to the present recycle process are suggested.

  10. Direct carbon dioxide emissions from civil aircraft

    NASA Astrophysics Data System (ADS)

    Grote, Matt; Williams, Ian; Preston, John

    2014-10-01

    Global airlines consume over 5 million barrels of oil per day, and the resulting carbon dioxide (CO2) emitted by aircraft engines is of concern. This article provides a contemporary review of the literature associated with the measures available to the civil aviation industry for mitigating CO2 emissions from aircraft. The measures are addressed under two categories - policy and legal-related measures, and technological and operational measures. Results of the review are used to develop several insights into the challenges faced. The analysis shows that forecasts for strong growth in air-traffic will result in civil aviation becoming an increasingly significant contributor to anthropogenic CO2 emissions. Some mitigation-measures can be left to market-forces as the key-driver for implementation because they directly reduce airlines' fuel consumption, and their impact on reducing fuel-costs will be welcomed by the industry. Other mitigation-measures cannot be left to market-forces. Speed of implementation and stringency of these measures will not be satisfactorily resolved unattended, and the current global regulatory-framework does not provide the necessary strength of stewardship. A global regulator with ‘teeth' needs to be established, but investing such a body with the appropriate level of authority requires securing an international agreement which history would suggest is going to be very difficult. If all mitigation-measures are successfully implemented, it is still likely that traffic growth-rates will continue to out-pace emissions reduction-rates. Therefore, to achieve an overall reduction in CO2 emissions, behaviour change will be necessary to reduce demand for air-travel. However, reducing demand will be strongly resisted by all stakeholders in the industry; and the ticket price-increases necessary to induce the required reduction in traffic growth-rates place a monetary-value on CO2 emissions of approximately 7-100 times greater than other common

  11. Sequestering Naturally Occurring Liquid Carbon Dioxide in the Deep Ocean

    NASA Astrophysics Data System (ADS)

    Capron, M. E.

    2008-12-01

    Liquid carbon dioxide has been found as shallow as 1,500 meters in seafloor ooze. Did the liquid carbon dioxide originate from volcanic activity? Or did bacteria convert organic matter, which started as atmospheric carbon dioxide, into methane and liquid carbon dioxide? At typical ocean temperatures carbon dioxide coming out of solution below 600 meters will be liquid. Therefore, one likely mechanism for generating liquid carbon dioxide in seafloor ooze is the bacterial decomposition of organic matter. This paper examines quantitative and qualitative bacterial decomposition of aquatic biomass, with an emphasis on assessing and demonstrating feasibility. Calculations suggest natural processes sequestering liquid carbon dioxide in the seafloor can be sustainably increased to decrease atmospheric carbon dioxide concentrations. First, algae growing on the ocean surface absorb carbon dioxide. The algae are then gathered into a submerged container. Naturally occurring bacteria will digest the algae producing methane, liquid carbon dioxide, and ammonium. The ammonium can be recycled as a nutrient for growing more algae. Bacterial decomposition continues in dilute solutions with any biomass. The process does not require any particular biomass. Also, concentrating the biomass by removing water is not essential. The buoyancy provided by water allows relatively inexpensive tension fabric structures to contain the dilute algae and decomposition products. Calculations based on algae growth in open ponds and experience with bacterial decomposition at 1 to 5 bar pressures suggest the economics of the associated macro-algae growing and harvesting can favor increasing ocean species diversity.

  12. Automated carbon dioxide cleaning system

    NASA Technical Reports Server (NTRS)

    Hoppe, David T.

    1991-01-01

    Solidified CO2 pellets are an effective blast media for the cleaning of a variety of materials. CO2 is obtained from the waste gas streams generated from other manufacturing processes and therefore does not contribute to the greenhouse effect, depletion of the ozone layer, or the environmental burden of hazardous waste disposal. The system is capable of removing as much as 90 percent of the contamination from a surface in one pass or to a high cleanliness level after multiple passes. Although the system is packaged and designed for manual hand held cleaning processes, the nozzle can easily be attached to the end effector of a robot for automated cleaning of predefined and known geometries. Specific tailoring of cleaning parameters are required to optimize the process for each individual geometry. Using optimum cleaning parameters the CO2 systems were shown to be capable of cleaning to molecular levels below 0.7 mg/sq ft. The systems were effective for removing a variety of contaminants such as lubricating oils, cutting oils, grease, alcohol residue, biological films, and silicone. The system was effective on steel, aluminum, and carbon phenolic substrates.

  13. Method of immobilizing carbon dioxide from gas streams

    DOEpatents

    Holladay, David W.; Haag, Gary L.

    1979-01-01

    This invention is a method for rapidly and continuously immobilizing carbon dioxide contained in various industrial off-gas streams, the carbon dioxide being immobilized as dry, stable, and substantially water-insoluble particulates. Briefly, the method comprises passing the gas stream through a fixed or fluidized bed of hydrated barium hydroxide to remove and immobilize the carbon dioxide by converting the bed to barium carbonate. The method has several important advantages: it can be conducted effectively at ambient temperature; it provides a very rapid reaction rate over a wide range of carbon dioxide concentrations; it provides high decontamination factors; and it has a high capacity for carbon dioxide. The invention is especially well suited for the removal of radioactive carbon dioxide from off-gases generated by nuclear-fuel reprocessing facilities and nuclear power plants.

  14. Carbon Dioxide Transport through Membranes*

    PubMed Central

    Missner, Andreas; Kügler, Philipp; Saparov, Sapar M.; Sommer, Klaus; Mathai, John C.; Zeidel, Mark L.; Pohl, Peter

    2008-01-01

    Several membrane channels, like aquaporin-1 (AQP1) and the RhAG protein of the rhesus complex, were hypothesized to be of physiological relevance for CO2 transport. However, the underlying assumption that the lipid matrix imposes a significant barrier to CO2 diffusion was never confirmed experimentally. Here we have monitored transmembrane CO2 flux (JCO2) by imposing a CO2 concentration gradient across planar lipid bilayers and detecting the resulting small pH shift in the immediate membrane vicinity. An analytical model, which accounts for the presence of both carbonic anhydrase and buffer molecules, was fitted to the experimental pH profiles using inverse problems techniques. At pH 7.4, the model revealed that JCO2 was entirely rate-limited by near-membrane unstirred layers (USL), which act as diffusional barriers in series with the membrane. Membrane tightening by sphingomyelin and cholesterol did not alter JCO2 confirming that membrane resistance was comparatively small. In contrast, a pH-induced shift of the CO2 hydration-dehydration equilibrium resulted in a relative membrane contribution of about 15% to the total resistance (pH 9.6). Under these conditions, a membrane CO2 permeability (3.2 ± 1.6 cm/s) was estimated. It indicates that cellular CO2 uptake (pH 7.4) is always USL-limited, because the USL size always exceeds 1 μm. Consequently, facilitation of CO2 transport by AQP1, RhAG, or any other protein is highly unlikely. The conclusion was confirmed by the observation that CO2 permeability of epithelial cell monolayers was always the same whether AQP1 was overexpressed in both the apical and basolateral membranes or not. PMID:18617525

  15. Enzymatic conversion of carbon dioxide.

    PubMed

    Shi, Jiafu; Jiang, Yanjun; Jiang, Zhongyi; Wang, Xueyan; Wang, Xiaoli; Zhang, Shaohua; Han, Pingping; Yang, Chen

    2015-10-01

    With the continuous increase in fossil fuels consumption and the rapid growth of atmospheric CO2 concentration, the harmonious state between human and nature faces severe challenges. Exploring green and sustainable energy resources and devising efficient methods for CO2 capture, sequestration and utilization are urgently required. Converting CO2 into fuels/chemicals/materials as an indispensable element for CO2 capture, sequestration and utilization may offer a win-win strategy to both decrease the CO2 concentration and achieve the efficient exploitation of carbon resources. Among the current major methods (including chemical, photochemical, electrochemical and enzymatic methods), the enzymatic method, which is inspired by the CO2 metabolic process in cells, offers a green and potent alternative for efficient CO2 conversion due to its superior stereo-specificity and region/chemo-selectivity. Thus, in this tutorial review, we firstly provide a brief background about enzymatic conversion for CO2 capture, sequestration and utilization. Next, we depict six major routes of the CO2 metabolic process in cells, which are taken as the inspiration source for the construction of enzymatic systems in vitro. Next, we focus on the state-of-the-art routes for the catalytic conversion of CO2 by a single enzyme system and by a multienzyme system. Some emerging approaches and materials utilized for constructing single-enzyme/multienzyme systems to enhance the catalytic activity/stability will be highlighted. Finally, a summary about the current advances and the future perspectives of the enzymatic conversion of CO2 will be presented. PMID:26055659

  16. Carbon dioxide: A substitute for phosgene

    SciTech Connect

    Aresta, M.; Quaranta, E.

    1997-03-01

    One of the many goals of the green chemistry movement is to eliminate the use of phosgene (COCl{sub 2}), an extremely hazardous compound used in many syntheses, including the production of carbamates, organic carbonates, and polymers. One of the most interesting options for eliminating this compound is to replace it with CO{sub 2}. In addition to carbon dioxide`s abundance and benign nature, it has the benefits of recycling carbon and of reducing the amount of CO{sub 2} released into the atmosphere when its use is linked with other processes that emit CO{sub 2}. Several synthetic strategies that do not use phosgene are under development. The authors briefly review the most interesting ones and then expand on the use of CO{sub 2} as a potential building block for organic carbamates, carbonates, and isocyanates. One of these routes, polycarbonate synthesis, is already in industrial-scale operation: PAC Polymers Inc. currently produces CO{sub 2}-epoxide copolymers. The synthesis of carbamates and substituted ureas has been developed, and this process awaits industrial exploitation.

  17. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Brian S. Turk; Raghubir P. Gupta; Alejandro Lopez-Ortiz; Douglas P. Harrison; Ya Liang

    2001-07-01

    Sodium based sorbents including sodium carbonate may be used to capture carbon dioxide from flue gas. A relatively concentrated carbon dioxide stream may be recoverable for sequestration when the sorbent is regenerated. Electrobalance tests indicated that sodium carbonate monohydrate was formed in a mixture of helium and water vapor at temperatures below 65 C. Additional compounds may also form, but this could not be confirmed. In the presence of carbon dioxide and water vapor, both the initial reaction rate of sodium carbonate with carbon dioxide and water and the sorbent capacity decreased with increasing temperature, consistent with the results from the previous quarter. Increasing the carbon dioxide concentration at constant temperature and water vapor concentration produced a measurable increase in rate, as did increasing the water vapor concentration at constant carbon dioxide concentration and temperature. Runs conducted with a flatter TGA pan resulted in a higher initial reaction rate, presumably due to improved gas-solid contact, but after a short time, there was no significant difference in the rates measured with the different pans. Analyses of kinetic data suggest that the surface of the sodium carbonate particles may be much hotter than the bulk gas due to the highly exothermic reaction with carbon dioxide and water, and that the rate of heat removal from the particle may control the reaction rate. A material and energy balance was developed for a cyclic carbonation/calcination process which captures about 26 percent of the carbon dioxide present in flue gas available at 250 C.

  18. PHOTOCHEMICAL REACTIONS AMONG FORMALDEHYDE, CHLORINE, AND NITROGEN DIOXIDE IN AIR

    EPA Science Inventory

    Photochemical reactions among chlorine, nitrogen dioxide, and formaldehyde were studied, using parts-per-million concentrations in 1 atm of air. The reactant mixtures were irradiated by ultraviolet fluorescent lamps and simultaneously analyzed by the Fourier transform infrared te...

  19. Asthma, sulfur dioxide, and the Clean Air Act

    SciTech Connect

    Boushey, H.

    1982-02-01

    Laboratory findings on the effects of sulfur dioxide in patients with asthma are related to theories about the mechanisms of bronchial hyperreactivity, an abnormality that may be fundamental to the pathogenesis of asthma and then to questions of national policy on air quality. Work has shown that people with asthma are abnormally sensitive to inhalation of sulfur dioxide and that bronchospasm may develop if they pursue activities that require light exercise while breathing air containing a level of sulfur dioxide permitted by current ambient air-quality standards. The provisions of the Clean Air Act of 1970 require that sensitive groups in the population be protected against adverse health effects, and our data therefore indicate the need for a short-term standard for sulfur dioxide.

  20. A Conductivity Device for Measuring Sulfur Dioxide in the Air

    ERIC Educational Resources Information Center

    Craig, James C.

    1972-01-01

    Described is a general electroconductivity device enabling students to determine sulfur dioxide concentration in a particular location, hopefully leading to a deeper understanding of the problem of air pollution. (DF)

  1. Amino acid-mediated impacts of elevated carbon dioxide and simulated root herbivory on aphids are neutralized by increased air temperatures

    PubMed Central

    Ryalls, James M. W.; Moore, Ben D.; Riegler, Markus; Gherlenda, Andrew N.; Johnson, Scott N.

    2015-01-01

    Changes in host plant quality, including foliar amino acid concentrations, resulting from global climate change and attack from multiple herbivores, have the potential to modify the pest status of insect herbivores. This study investigated how mechanically simulated root herbivory of lucerne (Medicago sativa) before and after aphid infestation affected the pea aphid (Acyrthosiphon pisum) under elevated temperature (eT) and carbon dioxide concentrations (eCO2). eT increased plant height and biomass, and eCO2 decreased root C:N. Foliar amino acid concentrations and aphid numbers increased in response to eCO2, but only at ambient temperatures, demonstrating the ability of eT to negate the effects of eCO2. Root damage reduced aboveground biomass, height, and root %N, and increased root %C and C:N, most probably via decreased biological nitrogen fixation. Total foliar amino acid concentrations and aphid colonization success were higher in plants with roots cut early (before aphid arrival) than those with roots cut late (after aphid arrival); however, this effect was counteracted by eT. These results demonstrate the importance of amino acid concentrations for aphids and identify individual amino acids as being potential factors underpinning aphid responses to eT, eCO2, and root damage in lucerne. Incorporating trophic complexity and multiple climatic factors into plant–herbivore studies enables greater insight into how plants and insects will interact in the future, with implications for sustainable pest control and future crop security. PMID:25403916

  2. Six-man, self-contained carbon dioxide concentrator system

    NASA Technical Reports Server (NTRS)

    Powell, J. D.; Schubert, F. H.; Marshall, R. D.; Shumar, J. W.

    1974-01-01

    A six man, self contained electrochemical carbon dioxide concentrating subsystem was successfully designed and fabricated. It was a preprototype engineering model designed to nominally remove 6.0 kg (13.2 lb) CO2/day with an inlet air CO2 partial pressure of 400 N/sq m (3 mm Hg) and an overcapacity removal capability of 12.0 kg (26.4 lb) CO2/day. The design specifications were later expanded to allow operation at space station prototype CO2 collection subsystem operating conditions.

  3. Designed amyloid fibers as materials for selective carbon dioxide capture

    PubMed Central

    Li, Dan; Furukawa, Hiroyasu; Deng, Hexiang; Liu, Cong; Yaghi, Omar M.; Eisenberg, David S.

    2014-01-01

    New materials capable of binding carbon dioxide are essential for addressing climate change. Here, we demonstrate that amyloids, self-assembling protein fibers, are effective for selective carbon dioxide capture. Solid-state NMR proves that amyloid fibers containing alkylamine groups reversibly bind carbon dioxide via carbamate formation. Thermodynamic and kinetic capture-and-release tests show the carbamate formation rate is fast enough to capture carbon dioxide by dynamic separation, undiminished by the presence of water, in both a natural amyloid and designed amyloids having increased carbon dioxide capacity. Heating to 100 °C regenerates the material. These results demonstrate the potential of amyloid fibers for environmental carbon dioxide capture. PMID:24367077

  4. Effects of carbon dioxide on Penicillium chrysogenum: an autoradiographic study

    SciTech Connect

    Edwards, A.G.; Ho, C.S.

    1988-06-20

    Previous research has shown that dissolved carbon dioxide causes significant changes in submerged penicillin fermentations, such as stunted, swollen hyphae, increased branching, lower growth rates, and lower penicillin productivity. Influent carbon dioxide levels of 5 and 10% were shown through the use of autoradiography to cause an increase in chitin synthesis in submerged cultures of Penicillium chrysogenum. At an influent 5% carbon dioxide level, chitin synthesis is ca. 100% greater in the subapical region of P. chrysogenum hyphae than that of the control, in which there was no influent carbon dioxide. Influent carbon dioxide of 10% caused an increase of 200% in chitin synthesis. It is believed that the cell wall must be plasticized before branching can occur and that high amounts of dissolved carbon dioxide cause the cell to lose control of the plasticizing effect, thus the severe morphological changes occur.

  5. Enriching blast furnace gas by removing carbon dioxide.

    PubMed

    Zhang, Chongmin; Sun, Zhimin; Chen, Shuwen; Wang, Baohai

    2013-12-01

    Blast furnace gas (BF gas) produced in the iron making process is an essential energy resource for a steel making work. As compared with coke oven gas, the caloric value of BF gas is too low to be used alone as fuel in hot stove because of its high concentrations of carbon dioxide and nitrogen. If the carbon dioxide in BF gas could be captured efficiently, it would meet the increasing need of high caloric BF gas, and develop methods to reusing and/or recycling the separated carbon dioxide further. Focused on this, investigations were done with simple evaluation on possible methods of removing carbon dioxide from BF gas and basic experiments on carbon dioxide capture by chemical absorption. The experimental results showed that in 100 minutes, the maximum absorbed doses of carbon dioxide reached 20 g/100 g with ionic liquid as absorbent. PMID:25078829

  6. Thermochemical generation of hydrogen and carbon dioxide

    NASA Technical Reports Server (NTRS)

    Lawson, Daniel D. (Inventor); England, Christopher (Inventor)

    1984-01-01

    Mixing of carbon in the form of high sulfur coal with sulfuric acid reduces the temperature of sulfuric acid decomposition from 830.degree. C. to between 300.degree. C. and 400.degree. C. The low temperature sulfuric acid decomposition is particularly useful in thermal chemical cycles for splitting water to produce hydrogen. Carbon dioxide is produced as a commercially desirable byproduct. Lowering of the temperature for the sulfuric acid decomposition or oxygen release step simplifies equipment requirements, lowers thermal energy input and reduces corrosion problems presented by sulfuric acid at conventional cracking temperatures. Use of high sulfur coal as the source of carbon for the sulfuric acid decomposition provides an environmentally safe and energy efficient utilization of this normally polluting fuel.

  7. Copolymerization of carbon dioxide and butadiene via a lactone intermediate.

    PubMed

    Nakano, Ryo; Ito, Shingo; Nozaki, Kyoko

    2014-04-01

    Although carbon dioxide has attracted broad interest as a renewable carbon feedstock, its use as a monomer in copolymerization with olefins has long been an elusive endeavour. A major obstacle for this process is that the propagation step involving carbon dioxide is endothermic; typically, attempted reactions between carbon dioxide and an olefin preferentially yield olefin homopolymerization. Here we report a strategy to circumvent the thermodynamic and kinetic barriers for copolymerizations of carbon dioxide and olefins by using a metastable lactone intermediate, 3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one, which is formed by the palladium-catalysed condensation of carbon dioxide and 1,3-butadiene. Subsequent free-radical polymerization of the lactone intermediate afforded polymers of high molecular weight with a carbon dioxide content of 33 mol% (29 wt%). Furthermore, the protocol was applied successfully to a one-pot copolymerization of carbon dioxide and 1,3-butadiene, and one-pot terpolymerizations of carbon dioxide, butadiene and another 1,3-diene. This copolymerization technique provides access to a new class of polymeric materials made from carbon dioxide. PMID:24651200

  8. Carbon Dioxide and the Greenhouse Effect: A Problem Evaluation Activity.

    ERIC Educational Resources Information Center

    Brewer, Carol A.; Beiswenger, Jane M.

    1993-01-01

    Describes exercises to examine the global carbon cycle. Students are asked to predict consequences of increased carbon dioxide emissions into the atmosphere and to suggest ways to mitigate problems associated with these higher levels of atmospheric carbon dioxide. A comparison modeling exercise examines some of the variables related to the success…

  9. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon...

  10. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....102-1, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed... 49 Transportation 2 2010-10-01 2010-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1...) § 179.102-1 Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon...

  11. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon...

  12. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon...

  13. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon...

  14. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon...

  15. Rapid setting of portland cement by greenhouse carbon dioxide capture

    SciTech Connect

    Wagh, A.S.; Singh, D.; Knox, L.J.

    1994-04-01

    Following the work by Berger et al. on rapid setting of calcium silicates by carbonation, a method of high-volume capture of CO{sub 2} in portland cement has been developed. Typically, 10--24 wt. % of CO{sub 2} produced by the calcination of calcium carbonate during clinkering, may be captured, and the set cement acquires most of its full strength in less than a day. The approach will have economic advantages in fabrication of precast structures, in emergency development of infrastructure during natural disasters, and in defense applications. Moreover, it will help the cement industry comply with the Clean Air Act of 1990 by sequestering the greenhouse carbon dioxide.

  16. Supercritical carbon dioxide: a solvent like no other

    PubMed Central

    Peach, Jocelyn

    2014-01-01

    Summary Supercritical carbon dioxide (scCO2) could be one aspect of a significant and necessary movement towards green chemistry, being a potential replacement for volatile organic compounds (VOCs). Unfortunately, carbon dioxide has a notoriously poor solubilising power and is famously difficult to handle. This review examines attempts and breakthroughs in enhancing the physicochemical properties of carbon dioxide, focusing primarily on factors that impact solubility of polar and ionic species and attempts to enhance scCO2 viscosity. PMID:25246947

  17. Six-fold Coordinated Carbon Dioxide VI

    SciTech Connect

    Iota, V; Yoo, C; Klepeis, J; Jenei, Z

    2006-03-01

    Under standard conditions, carbon dioxide (CO{sub 2}) is a simple molecular gas and an important atmospheric constituent while silicon dioxide (SiO{sub 2}) is a covalent solid, and represents one of the fundamental minerals of the planet. The remarkable dissimilarity between these two group IV oxides is diminished at higher pressures and temperatures as CO{sub 2} transforms to a series of solid phases, from simple molecular to a fully covalent extended-solid V, structurally analogous to SiO{sub 2} tridymite. Here, we present the discovery of a new extended-solid phase of carbon dioxide (CO{sub 2}): a six-fold coordinated stishovite-like phase VI, obtained by isothermal compression of associated CO{sub 2}-II above 50GPa at 530-650K. Together with the previously reported CO{sub 2}-V and a-carbonia, this new extended phase indicates a fundamental similarity between CO{sub 2}--a prototypical molecular solid, and SiO{sub 2}--one of Earth's fundamental building blocks. The phase diagram suggests a limited stability domain for molecular CO{sub 2}-I, and proposes that the conversion to extended-network solids above 40-50 GPa occurs via intermediate phases II, III, and IV. The crystal structure of phase VI suggests strong disorder along the caxis in stishovite-like P4{sub 2}/mnm, with carbon atoms manifesting an average six-fold coordination within the framework of sp{sup 3} hybridization.

  18. Toward Solar Fuels: Photocatalytic Conversion of Carbon Dioxide to Hydrocarbons

    SciTech Connect

    Roy, SC; Varghese, OK; Paulose, M; Grimes, CA

    2010-03-01

    The past several decades have seen a significant rise in atmospheric carbon dioxide levels resulting from the combustion of hydrocarbon fuels. A solar energy based technology to recycle carbon dioxide into readily transportable hydrocarbon fuel (i.e., a solar fuel) would help reduce atmospheric CO2 levels and partly fulfill energy demands within the present hydrocarbon based fuel infrastructure. We review the present status of carbon dioxide conversion techniques, with particular attention to a recently developed photocatalytic process to convert carbon dioxide and water vapor into hydrocarbon fuels using sunlight.

  19. A tenuous carbon dioxide atmosphere on Jupiter's moon Callisto

    NASA Technical Reports Server (NTRS)

    Carlson, R. W.

    1999-01-01

    An off-limb scan of Callisto was conducted by the Galileo near-infrared mapping spectrometer to search for a carbon dioxide atmosphere. Airglow in the carbon dioxide nu3 band was observed up to 100 kilometers above the surface and indicates the presence of a tenuous carbon dioxide atmosphere with surface pressure of 7.5 x 10(-12) bar and a temperature of about 150 kelvin, close to the surface temperature. A lifetime on the order of 4 years is suggested, based on photoionization and magnetospheric sweeping. Either the atmosphere is transient and was formed recently or some process is currently supplying carbon dioxide to the atmosphere.

  20. [Determination of carbon dioxide released from soil at different humidities].

    PubMed

    Imshenetskiĭ, A A; Murzakov, B G

    1978-01-01

    The detection of soil microorganisms by their evolution of carbon dioxide does not always correlate with the number of microorganisms and the rate of biochemical processes in soil. New microbial populations appear in the incubation chamber as the concentration of carbon dioxide increases; this results in an increase in the activity of such processes as photosynthesis, chemosynthesis and heterotrophic assimilation of carbon dioxide. Life detection on other planets by determining carbon dioxide evolved from the ground may lead to erroneous conclusions on the presence of microorganism in the ground. PMID:745559

  1. Carbon dioxide absorbent and method of using the same

    SciTech Connect

    Perry, Robert James; O'Brien, Michael Joseph

    2015-12-29

    In accordance with one aspect, the present invention provides a composition which contains the amino-siloxane structures I, or III, as described herein. The composition is useful for the capture of carbon dioxide from process streams. In addition, the present invention provides methods of preparing the amino-siloxane composition. Another aspect of the present invention provides methods for reducing the amount of carbon dioxide in a process stream employing the amino-siloxane compositions of the invention, as species which react with carbon dioxide to form an adduct with carbon dioxide.

  2. Carbon dioxide absorbent and method of using the same

    SciTech Connect

    Perry, Robert James; O'Brien, Michael Joseph

    2014-06-10

    In accordance with one aspect, the present invention provides a composition which contains the amino-siloxane structures I, or III, as described herein. The composition is useful for the capture of carbon dioxide from process streams. In addition, the present invention provides methods of preparing the amino-siloxane composition. Another aspect of the present invention provides methods for reducing the amount of carbon dioxide in a process stream employing the amino-siloxane compositions of the invention, as species which react with carbon dioxide to form an adduct with carbon dioxide.

  3. Cost analysis of carbon dioxide concentrators

    NASA Technical Reports Server (NTRS)

    Yakut, M. M.

    1972-01-01

    A methodology is developed to predict the relevant contributions of the more intangible cost elements encountered in the development of flight-qualified hardware and is used to predict the costs of three carbon dioxide concentration systems. The cost and performance data from Gemini, Skylab, and other programs are utilized as a basis for establishing the cost estimating relationships. The concentration systems analyzed are the molecular sieves C02 concentrator, the hydrogen-depolarized concentrator, and the regenerable solid desiccant concentrator. Besides the cost estimates for each system, their comparative criteria including relative characteristics, operational differences, and development status are considered.

  4. Electrochemical carbon dioxide concentrator subsystem development

    NASA Technical Reports Server (NTRS)

    Heppner, D. B.; Dahlausen, M. J.; Schubert, F. H.

    1983-01-01

    The fabrication of a one-person Electrochemical Depolarized Carbon Dioxide Concentrator subsystem incorporating advanced electrochemical, mechanical, and control and monitor instrumentation concepts is discussed. This subsystem included an advanced liquid cooled unitized core composite cell module and integrated electromechanical components. Over 1800 hours with the subsystem with removal efficiencies between 90%. and 100%; endurance tests with a Fluid Control Assembly which integrates 11 gas handling components of the subsystem; and endurance testing of a coolant control assembly which integrates a coolant pump, diverter valve and a liquid accumulator were completed.

  5. Searching for clues to ancient carbon dioxide

    SciTech Connect

    Appenzeller, T.

    1993-02-12

    Something on Earth just won't stop fiddling with the thermostat. In the past 500 million years, the planet has shivered through ice ages lasting millions of years and sweltered through episodes of global warmth. Climatologists, eager to know what keeps jiggling the planet's temperature setting, have focused their suspicions on carbon dioxide, the same heat-trapping gas expected to drive up temperatures in coming decades. Catching this suspect in the act has been difficult, however; the atmospheres of millions of years ago are gone with the wind.

  6. Capture of carbon dioxide by hybrid sorption

    SciTech Connect

    Srinivasachar, Srivats

    2014-09-23

    A composition, process and system for capturing carbon dioxide from a combustion gas stream. The composition has a particulate porous support medium that has a high volume of pores, an alkaline component distributed within the pores and on the surface of the support medium, and water adsorbed on the alkaline component, wherein the proportion of water in the composition is between about 5% and about 35% by weight of the composition. The process and system contemplates contacting the sorbent and the flowing gas stream together at a temperature and for a time such that some water remains adsorbed in the alkaline component when the contact of the sorbent with the flowing gas ceases.

  7. A Vortex Contactor for Carbon Dioxide Separations

    SciTech Connect

    Raterman, Kevin Thomas; Mc Kellar, Michael George; Turner, Terry Donald; Podgorney, Anna Kristine; Stacey, Douglas Edwin; Stokes, B.; Vranicar, J.

    2001-05-01

    Many analysts identify carbon dioxide (CO2) capture and separation as a major roadblock in efforts to cost effectively mitigate greenhouse gas emissions via sequestration. An assessment 4 conducted by the International Energy Agency (IEA) Greenhouse Gas Research and Development Programme cited separation costs from $35 to $264 per tonne of CO2 avoided for a conventional coal fired power plant utilizing existing capture technologies. Because these costs equate to a greater than 40% increase in current power generation rates, it appears obvious that a significant improvement in CO2 separation technology is required if a negative impact on the world economy is to be avoided.

  8. Simulation of carbon dioxide insufflation via a diffuser in an open surgical wound model.

    PubMed

    Cater, John E; van der Linden, Jan

    2015-01-01

    Flow within a model surgical opening during insufflation with heated carbon dioxide was studied using computational fluid dynamics. A volume of fluid method was used to simulate the mixture of ambient air and carbon dioxide gas. The negative buoyancy of the carbon dioxide caused it to fill the wound and form a protective layer on the internal surfaces for a range of flow rates, temperatures, and angles of patient inclination. It was observed that the flow remained attached to the surface of the model due to the action of the Coanda effect. A flow rate of 10 L/min was sufficient to maintain a warm carbon dioxide barrier for a moderately sized surgical incision for all likely angles of inclination. PMID:25103346

  9. Carbon dioxide research plan. A summary

    SciTech Connect

    Trivelpiece, Alvin W.; Koomanoff, F. A.; Suomi, Verner E.

    1983-11-01

    The Department of Energy is the lead federal agency for research related to atmospheric carbon dioxide. Its responsibility is to sponsor a program of relevant research, and to coordinate this research with that of others. As part of its responsibilities, the Department of Energy has prepared a research plan. The plan documented in this Summary delineated the logic, objectives, organization, background and current status of the research activities. The Summary Plan is based on research subplans in four specific areas: global carbon cycle, climate effects, vegetative response and indirect effects. These subplans have emanated from a series of national and international workshops, conferences, and from technical reports. The plans have been peer reviewed by experts in the relevant scientific fields. Their execution is being coordinated between the responsible federal and international government agencies and the involved scientific community.

  10. The kinetics of binding carbon dioxide in magnesium carbonate

    SciTech Connect

    Butt, D.P.; Lackner, K.S.; Wendt, C.H.; Vaidya, R.; Pile, D.L.; Park, Y.; Holesinger, T.; Harradine, D.M.; Nomura, Koji |

    1998-08-01

    Humans currently consume about 6 Gigatons of carbon annually as fossil fuel. In some sense, the coal industry has a unique advantage over many other anthropogenic and natural emitters of CO{sub 2} in that it owns large point sources of CO{sub 2} from which this gas could be isolated and disposed of. If the increased energy demands of a growing world population are to be satisfied from coal, the implementation of sequestration technologies will likely be unavoidable. The authors` method of sequestration involves binding carbon dioxide as magnesium carbonate, a thermodynamically stable solid, for safe and permanent disposal, with minimal environmental impact. The technology is based on extracting magnesium hydroxide from common ultramafic rock for thermal carbonation and subsequent disposition. The economics of the method appear to be promising, however, many details of the proposed process have yet to be optimized. Realization of a cost effective method requires development of optimal technologies for efficient extraction and thermal carbonation.

  11. Chemical Reactions in Supercritical Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Wai, Chien M.; Hunt, Fred; Ji, Min; Chen, Xiaoyuan

    1998-12-01

    Utilizing supercritical fluids as environmentally benign solvents for chemical synthesis is one of the new approaches in the "greening" of chemistry. Carbon dioxide is the most widely used gas for supercritical fluid studies because of its moderate critical constants, nontoxic nature, and availability in pure form. One unique property of supercritical carbon dioxide (sc-CO2) is its high solubility for fluorinated compounds. Thus sc-CO2 can be used to replace Freons that are conventionally used as solvents for synthesis of perfluoro-polymers. Another property of sc-CO2 is its miscibility with gases such as H2. Heterogeneous reactions involving these gases may become homogeneous reactions in sc-CO2. Reactions in sc-CO2 may offer several advantages including controlling phase behavior and products, increasing speed of reactions, and obtaining specific reaction channels. This paper describes the following nine types of chemical reactions reported in the literature utilizing sc-CO2 as a solvent to illustrate the unique properties of the supercritical fluid reaction systems: (i) hydrogenation and hydroformylation, (ii) synthesis of organometallic compounds, (iii) metal chelation and extraction, (iv) preparation of inorganic nanoparticles, (v) stereo-selectivity of lipase-catalyzed reactions, (vi) asymmetric catalytic hydrogenation, (vii) polymerization, (viii) Diels-Alder reaction, and (ix) free radical reactions.

  12. Six-fold coordinated carbon dioxide VI

    SciTech Connect

    Iota, Valentin; Yoo, Choong-Shik; Klepeis, Jae-Hyun; Jenei, Zsolt; Evans, William; Cynn, Hyunchae

    2008-06-16

    Under standard conditions, carbon dioxide (CO{sub 2}) is a simple molecular gas and an important atmospheric constituent, whereas silicon dioxide (SiO{sub 2}) is a covalent solid, and one of the fundamental minerals of the planet. The remarkable dissimilarity between these two group IV oxides is diminished at higher pressures and temperatures as CO{sub 2} transforms to a series of solid phases, from simple molecular to a fully covalent extended-solid V, structurally analogous to SiO{sub 2} tridymite. Here, we present the discovery of an extended-solid phase of CO{sub 2}: a six-fold coordinated stishovite-like phase VI, obtained by isothermal compression of associated CO{sub 2}-II above 50 GPa at 530-650 K. Together with the previously reported CO{sub 2}-V and a-carbonia, this extended phase indicates a fundamental similarity between CO{sub 2} (a prototypical molecular solid) and SiO{sub 2} (one of Earth's fundamental building blocks). We present a phase diagram with a limited stability domain for molecular CO{sub 2}-I, and suggest that the conversion to extended-network solids above 40-50 GPa occurs via intermediate phases II, III and IV. The crystal structure of phase VI suggests strong disorder along the c axis in stishovite-like P4{sub 2}/mnm, with carbon atoms manifesting an average six-fold coordination within the framework of sp{sup 3} hybridization.

  13. Pharmaceutical applications of supercritical carbon dioxide.

    PubMed

    Kaiser, C S; Römpp, H; Schmidt, P C

    2001-12-01

    The appearance of a supercritical state was already observed at the beginning of the 19th century. Nevertheless, the industrial extraction of plant and other natural materials started about twenty years ago with the decaffeination of coffee. Today carbon dioxide is the most common gas for supercritical fluid extraction in food and pharmaceutical industry. Since pure supercritical carbon dioxide is a lipophilic solvent, mixtures with organic solvents, especially alcohols, are used to increase the polarity of the extraction fluid; more polar compounds can be extracted in this way. The main fields of interest are the extraction of vegetable oils from plant material in analytical and preparative scale, the preparation of essential oils for food and cosmetic industry and the isolation of substances of pharmaceutical relevance. Progress in research was made by the precise measurement of phase equilibria data by means of different methods. Apart from extraction, supercritical fluid chromatography was introduced in the field of analytics, as well as micro- and nanoparticle formation using supercritical fluids as solvent or antisolvent. This review presents pharmaceutical relevant literature of the last twenty years with special emphasis on extraction of natural materials. PMID:11802652

  14. Disintegration of Carbon Dioxide Molecules in a Microwave Plasma Torch

    PubMed Central

    Kwak, Hyoung S.; Uhm, Han S.; Hong, Yong C.; Choi, Eun H.

    2015-01-01

    A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study of carbon dioxide disintegration and gas temperature effects on the molecular fraction characteristics in the carbon dioxide plasma of a microwave plasma torch under atmospheric pressure is carried out. An analytical investigation of carbon dioxide disintegration indicates that substantial fraction of carbon dioxide molecules disintegrate and form other compounds in the torch. For example, the normalized particle densities at center of plasma are given by nCO2/nN = 6.12 × 10−3, nCO/nN = 0.13, nC/nN = 0.24, nO/nN = 0.61, nC2/nN = 8.32 × 10−7, nO2/nN = 5.39 × 10−5, where nCO2, nCO, nC, nO, nC2, and nO2 are carbon dioxide, carbon monoxide, carbon and oxygen atom, carbon and oxygen molecule densities, respectively. nN is the neutral particle density. Emission profiles of the oxygen and carbon atom radicals and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch. PMID:26674957

  15. Disintegration of Carbon Dioxide Molecules in a Microwave Plasma Torch.

    PubMed

    Kwak, Hyoung S; Uhm, Han S; Hong, Yong C; Choi, Eun H

    2015-01-01

    A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study of carbon dioxide disintegration and gas temperature effects on the molecular fraction characteristics in the carbon dioxide plasma of a microwave plasma torch under atmospheric pressure is carried out. An analytical investigation of carbon dioxide disintegration indicates that substantial fraction of carbon dioxide molecules disintegrate and form other compounds in the torch. For example, the normalized particle densities at center of plasma are given by nCO2/nN = 6.12 × 10(-3), nCO/nN = 0.13, nC/nN = 0.24, nO/nN = 0.61, nC2/nN = 8.32 × 10(-7), nO2/nN = 5.39 × 10(-5), where nCO2, nCO, nC, nO, nC2, and nO2 are carbon dioxide, carbon monoxide, carbon and oxygen atom, carbon and oxygen molecule densities, respectively. nN is the neutral particle density. Emission profiles of the oxygen and carbon atom radicals and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch. PMID:26674957

  16. Disintegration of Carbon Dioxide Molecules in a Microwave Plasma Torch

    NASA Astrophysics Data System (ADS)

    Kwak, Hyoung S.; Uhm, Han S.; Hong, Yong C.; Choi, Eun H.

    2015-12-01

    A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study of carbon dioxide disintegration and gas temperature effects on the molecular fraction characteristics in the carbon dioxide plasma of a microwave plasma torch under atmospheric pressure is carried out. An analytical investigation of carbon dioxide disintegration indicates that substantial fraction of carbon dioxide molecules disintegrate and form other compounds in the torch. For example, the normalized particle densities at center of plasma are given by nCO2/nN = 6.12 × 10-3, nCO/nN = 0.13, nC/nN = 0.24, nO/nN = 0.61, nC2/nN = 8.32 × 10-7, nO2/nN = 5.39 × 10-5, where nCO2, nCO, nC, nO, nC2, and nO2 are carbon dioxide, carbon monoxide, carbon and oxygen atom, carbon and oxygen molecule densities, respectively. nN is the neutral particle density. Emission profiles of the oxygen and carbon atom radicals and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch.

  17. Sources and sinks of carbon dioxide in the Arctic regions

    SciTech Connect

    Gosink, T. A.; Kelley, J. J.

    1982-01-01

    The data base required to adequately ascertain seasonal source and sink strengths in the arctic regions is difficult to obtain. However, there are now a reasonable quantity of data for this polar region to estimate sources and sinks within the Arctic which may contribute significantly to the annual tropospheric CO/sub 2/ concentration fluctuation. The sea-ice-air and the sea-air interfaces account for most of the contribution to the sources and sinks for carbon dioxide. Although the arctic and subarctic region is small in extent, it certainly is not impervious and ice sealed. Our estimate, based on historical data and current research, indicates that the Arctic, which is about 4% of the earth's surface, is an annual net sink for approx. 10/sup 15/ g CO/sub 2/ accounting for an equivalent of approx. 3% of the annual anthropogenic contribution of CO/sub 2/ to the troposphere.

  18. Carbon dioxide emissions from estuaries of northern and northeastern Brazil

    PubMed Central

    Noriega, Carlos; Araujo, Moacyr

    2014-01-01

    The carbon dioxide flux through the air–water interface of coastal estuarine systems must be quantified to understand the regional balance of carbon and its transport through adjacent coastal regions. We estimated and calculated the emissions of carbon dioxide (FCO2) and the partial pressure of CO2 (pCO2) values in 28 estuarine environments at a variety of spatial scales in the northern and northeastern regions of Brazil. The results showed a mean FCO2 (water to air) of 55 ± 45 mmol·m−2·d−1. Additionally, a negative correlation between dissolved oxygen saturation and pCO2 was observed, indicating a control by biological processes and especially by organic matter degradation. This leads to increased dissolved CO2 concentration in estuarine waters which results in a pCO2 that reached 8,638 μatm. Our study suggests that northern and northeastern Brazilian estuaries act as sources of atmospheric CO2. The range of pCO2 observed were similar to those found in inner estuaries in other places around the world, with the exception of a few semi-arid estuaries (Köppen climate classification – BSh) in which record low levels of pCO2 have been detected. PMID:25145418

  19. Cationic Polymerization of Vegetable Oils in Supercritical Carbon Dioxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polymers derived from vegetable oils have been prepared in supercritical carbon dioxide (scCO2) medium by cationic polymerization. Boron trifluoride diethyl etherate BF3.O(C2H2)2 are used as initiator. Influences of polymerization temperature, initiator amount, and carbon dioxide pressure on the m...

  20. Carbon Dioxide and Global Warming: A Failed Experiment

    ERIC Educational Resources Information Center

    Ribeiro, Carla

    2014-01-01

    Global warming is a current environmental issue that has been linked to an increase in anthropogenic carbon dioxide in the atmosphere. To raise awareness of the problem, various simple experiments have been proposed to demonstrate the effect of carbon dioxide on the planet's temperature. This article describes a similar experiment, which…

  1. Solid amine compounds as sorbents for carbon dioxide: A concept

    NASA Technical Reports Server (NTRS)

    Sutton, J. G.; Heimlich, P. F.; Tepper, E. H.

    1972-01-01

    Solid amine compounds were examined as possible absorbents for removal of carbon dioxide in life support systems of type which may be employed in high altitude aircraft, spacecraft, or submarines. Many solid amine compounds release absorbed carbon dioxide when heated in vacuum, therefore, when properly packaged spent amine compounds can be readily regenerated and put back into service.

  2. Promising flame retardant textile in supercritical carbon dioxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since carbon dioxide is non-toxic, non-flammable and cost-effective, supercritical carbon dioxide (scCO2) is widely used in textile dyeing applications. Due to its environmentally benign character, scCO2 is considered in green chemistry as a substitute for organic solvents in chemical reactions. O...

  3. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CFR part 1065, subparts C and D, may be used in lieu of the procedures in this section. ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Provisions § 91.320 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service,...

  4. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be used in lieu... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Test Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its...

  5. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CFR part 1065, subparts C and D, may be used in lieu of the procedures in this section. ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Provisions § 91.320 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service,...

  6. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be used in lieu... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Test Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its...

  7. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., system check, and calibration test procedures specified in 40 CFR part 1065, subparts C and D, may be... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 90... Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its initial use and...

  8. Investigating Diffusion and Entropy with Carbon Dioxide-Filled Balloons

    ERIC Educational Resources Information Center

    Jadrich, James; Bruxvoort, Crystal

    2010-01-01

    Fill an ordinary latex balloon with helium gas and you know what to expect. Over the next day or two the volume will decrease noticeably as helium escapes from the balloon. So what happens when a latex balloon is filled with carbon dioxide gas? Surprisingly, carbon dioxide balloons deflate at rates as much as an order of magnitude faster than…

  9. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be used in lieu... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Test Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its...

  10. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be used in lieu... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 89... Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its introduction...

  11. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration... Emission Test Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its...

  12. 40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., and calibration test procedures specified in 40 CFR part 86, subpart D, may be used in lieu of the... 40 Protection of Environment 20 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration... Exhaust Test Procedures § 86.1324-84 Carbon dioxide analyzer calibration. Prior to its introduction...

  13. 40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., and calibration test procedures specified in 40 CFR part 86, subpart D, may be used in lieu of the... 40 Protection of Environment 20 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Exhaust Test Procedures § 86.1324-84 Carbon dioxide analyzer calibration. Prior to its introduction...

  14. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Emission Test Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its...

  15. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Emission Test Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its...

  16. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 91....320 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service, and...

  17. 40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., and calibration test procedures specified in 40 CFR part 86, subpart D, may be used in lieu of the... 40 Protection of Environment 19 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Exhaust Test Procedures § 86.1324-84 Carbon dioxide analyzer calibration. Prior to its introduction...

  18. 40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., and calibration test procedures specified in 40 CFR part 86, subpart D, may be used in lieu of the... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Exhaust Test Procedures § 86.1324-84 Carbon dioxide analyzer calibration. Prior to its introduction...

  19. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CFR part 1065, subparts C and D, may be used in lieu of the procedures in this section. ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Provisions § 91.320 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service,...

  20. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be used in lieu... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration... Test Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its...

  1. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Emission Test Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its...

  2. Carbon dioxide sequestration by ex-situ mineral carbonation

    SciTech Connect

    O'Connor, W.K.; Dahlin, D.C.; Turner, P.C.; and Walters, R.P.

    2000-01-01

    The process developed for carbon dioxide sequestration utilizes a slurry of water mixed with olivine- forsterite end member (Mg{sub 2}SiO{sub 4}), which is reacted with supercritical CO{sub 2} to produce magnesite (MgCO{sub 3}). Carbon dioxide is dissolved in water to form carbonic acid, which likely dissociates to H{sup +} and HCO{sub 3}{sup -}. The H{sup +} hydrolyzes the silicate mineral, freeing the cation (Mg{sup 2+}), which reacts with the HCO{sub 3}{sup -} to form the solid carbonate. Results of the baseline tests, conducted on ground products of the natural mineral, have demonstrated that the kinetics of the reaction are slow at ambient temperature (22 degrees C) and subcritical CO{sub 2} pressures (below 7.4 MPa). However, at elevated temperature and pressure, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant conversion to the carbonate occurs. Extent of reaction is roughly 90% within 24 h, at 185 degrees C and partial pressure of CO{sub 2} (P{sub CO{sub 2}}) of 11.6 MPa. Current studies suggest that reaction kinetics can be improved by pretreatment of the mineral, catalysis of the reaction, and/or solution modification. Subsequent tests are intended to examine these options, as well as other mineral groups.

  3. Does free-air carbon dioxide enrichment affect photochemical energy use by evergreen trees in different seasons? A chlorophyll fluorescence study of mature loblolly pine

    SciTech Connect

    Hymus, G.J.; Ellsworth, D.S.; Baker, N.R.; Long, S.P.

    1999-08-01

    Previous studies of the effects of growth at elevated CO{sup 2} on energy partitioning in the photosynthetic apparatus have produced conflicting results. The hypothesis was developed and tested that elevated CO{sub 2} increases photochemical energy use when there is a high demand for assimilates and decreases usage when demand is low. Modulated chlorophyll a fluorescence and leaf gas exchange were measured on needles at the tope of a mature, 12-m loblolly pine (Pinus taeda L.l) forest. Trees were exposed to ambient CO{sub 2} or ambient plus 20 Pa CO{sub 2} using free-air CO{sub 2} enrichment. During April and August, periods of shoot growth, light-saturated photo-synthesis and linear electron transport were increased by elevated CO{sub 2}. In November, when growth had ceased but temperatures were still moderate, CO{sub 2} treatment had no significant effect on linear electron transport. In February, when low temperatures were likely to inhibit translocation, CO{sub 2} treatment caused a significant decrease in linear electron transport. This coincided with a slower recovery of the maximum photosystem II efficiency on transfer of needles to the shade, indicating that growth in elevated CO{sub 2} induced a more persistent photoinhibition. Both the summer increase and the winter decrease in linear electron transport in elevated CO{sub 2} resulted from a change in photochemical quenching, not in the efficiency of energy transfer within the photosystem II antenna. There was no evidence of any effect of CO{sub 2} on photochemical energy sinks other than carbon metabolism. Their results suggest that elevated CO{sub 2} may increase the effects of winter stress on evergreen foliage.

  4. Determination of sulfur forms in wine including free and total sulfur dioxide based on molecular absorption of carbon monosulfide in the air-acetylene flame.

    PubMed

    Huang, Mao Dong; Becker-Ross, Helmut; Florek, Stefan; Heitmann, Uwe; Okruss, Michael; Patz, Claus-Dieter

    2008-01-01

    A new method for the determination of sulfur forms in wine, i.e., free SO(2), total SO(2), bound SO(2), total S, and sulfate, is presented. The method is based on the measurement of the carbon monosulfide (CS) molecular absorption produced in a conventional air-acetylene flame using high-resolution continuum source absorption spectrometry. Individual sulfur forms can be distinguished because of the different sensitivities of the corresponding CS molecular absorption. The sensitivity of free SO(2) is about three times higher than the value for bound SO(2) and sulfate. The method makes use of procedures similar to those used in classic reference methods. Its performance is verified by analyzing six wine samples. Relative standard deviations are between 5 and 13% for free SO(2) and between 1 and 3% for total SO(2). For the validation of the accuracy of the new method, the results are compared with those of reference methods. The agreement of the values for total SO(2) with values of the classic method is satisfactory: five out of six samples show deviations less than 16%. Due to the instability of free SO(2) in wine and the known problems of the used reference method, serious deviations of the free SO(2) results are found for three samples. The evaluation of the limits of detection focuses on the value for free SO(2), which is the sulfur form having by far the lowest concentration in wine. Here, the achievable limit of detection is 1.8 mg L(-1). [figure: see text] Detection of non-metal elements using continuum source flame absorption spectrometry. PMID:17972067

  5. Carbon dioxide insufflation during screening unsedated colonoscopy: a randomised clinical trial

    PubMed Central

    Szura, Miroslaw; Matyja, Andrzej; Kulig, Jan

    2015-01-01

    One of the methods used to reduce pain and discomfort during colonoscopy is insufflation of carbon dioxide instead of air. However, the actual benefit of carbon dioxide insufflation is not unequivocally proven. The aim of the study was to evaluate the advantages of carbon dioxide insufflation during screening colonoscopy. A total of 200 patients undergoing screening colonoscopy between 2010 and 2011 were included in the prospective, randomized study carried out in a surgical referral center. Screening unsedated colonoscopy with either air or carbon dioxide insufflation was performed; patients were randomly assigned to air or carbon dioxide group by means of computer-generated randomization lists. All examinations were performed in an ambulatory setting with standard videocolonoscopes. The main outcomes analyzed were (a) duration of the entire procedure, (b) cecal intubation time, and (c) pain severity immediately, 15, and 60 min after the procedure. Group I included 59 women and 41 men and group II included 51 women and 49 men. The duration of the procedure was circa 10 min in both groups. Pain score values immediately and 15 min after the procedure were similar in both groups (P=0.624 and 0.305, respectively). A lower pain score was observed only after 60 min in patients insufflated with carbon dioxide (1.28 vs. 1.54, P=0.008). No pain reduction was observed in women and in obese patients (BMI>30). Carbon dioxide insufflation during unsedated screening colonoscopy does not decrease the duration of the procedure and appears to reduce pain intensity at 60 min after examination to an extent without clinical significance. The study was registered at ClinicalTrials.gov, number NCT01461564. PMID:24915135

  6. Carbon dioxide stripping in aquaculture. part 1: terminology and reporting

    USGS Publications Warehouse

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

    The removal of carbon dioxide gas in aquacultural systems is much more complex than for oxygen or nitrogen gas because of liquid reactions of carbon dioxide and their kinetics. Almost all published carbon dioxide removal information for aquaculture is based on the apparent removal value after the CO2(aq) + HOH ⇔ H2CO3 reaction has reached equilibrium. The true carbon dioxide removal is larger than the apparent value, especially for high alkalinities and seawater. For low alkalinity freshwaters (<2000 μeq/kg), the difference between the true and apparent removal is small and can be ignored for many applications. Analytical and reporting standards are recommended to improve our understanding of carbon dioxide removal.

  7. Carbon dioxide absorbent and method of using the same

    DOEpatents

    Perry, Robert James; Lewis, Larry Neil; O'Brien, Michael Joseph; Soloveichik, Grigorii Lev; Kniajanski, Sergei; Lam, Tunchiao Hubert; Lee, Julia Lam; Rubinsztajn, Malgorzata Iwona

    2011-10-04

    In accordance with one aspect, the present invention provides an amino-siloxane composition comprising at least one of structures I, II, III, IV or V said compositions being useful for the capture of carbon dioxide from gas streams such as power plant flue gases. In addition, the present invention provides methods of preparing the amino-siloxane compositions are provided. Also provided are methods for reducing the amount of carbon dioxide in a process stream employing the amino-siloxane compositions of the invention as species which react with carbon dioxide to form an adduct with carbon dioxide. The reaction of the amino-siloxane compositions provided by the present invention with carbon dioxide is reversible and thus, the method provides for multicycle use of said compositions.

  8. Photobiological hydrogen production and carbon dioxide sequestration

    NASA Astrophysics Data System (ADS)

    Berberoglu, Halil

    Photobiological hydrogen production is an alternative to thermochemical and electrolytic technologies with the advantage of carbon dioxide sequestration. However, it suffers from low solar to hydrogen energy conversion efficiency due to limited light transfer, mass transfer, and nutrient medium composition. The present study aims at addressing these limitations and can be divided in three parts: (1) experimental measurements of the radiation characteristics of hydrogen producing and carbon dioxide consuming microorganisms, (2) solar radiation transfer modeling and simulation in photobioreactors, and (3) parametric experiments of photobiological hydrogen production and carbon dioxide sequestration. First, solar radiation transfer in photobioreactors containing microorganisms and bubbles was modeled using the radiative transport equation (RTE) and solved using the modified method of characteristics. The study concluded that Beer-Lambert's law gives inaccurate results and anisotropic scattering must be accounted for to predict the local irradiance inside a photobioreactor. The need for accurate measurement of the complete set of radiation characteristics of microorganisms was established. Then, experimental setup and analysis methods for measuring the complete set of radiation characteristics of microorganisms have been developed and successfully validated experimentally. A database of the radiation characteristics of representative microorganisms have been created including the cyanobacteria Anabaena variabilis, the purple non-sulfur bacteria Rhodobacter sphaeroides and the green algae Chlamydomonas reinhardtii along with its three genetically engineered strains. This enabled, for the first time, quantitative assessment of the effect of genetic engineering on the radiation characteristics of microorganisms. In addition, a parametric experimental study has been performed to model the growth, CO2 consumption, and H 2 production of Anabaena variabilis as functions of

  9. Ruthenium-catalysed alkoxycarbonylation of alkenes with carbon dioxide.

    PubMed

    Wu, Lipeng; Liu, Qiang; Fleischer, Ivana; Jackstell, Ralf; Beller, Matthias

    2014-01-01

    Alkene carbonylations represent a major technology for the production of value-added bulk and fine chemicals. Nowadays, all industrial carbonylation processes make use of highly toxic and flammable carbon monoxide. Here we show the application of abundantly available carbon dioxide as C1 building block for the alkoxycarbonylations of industrially important olefins in the presence of a convenient and inexpensive ruthenium catalyst system. In our system, carbon dioxide works much better than the traditional combination of carbon monoxide and alcohols. The unprecedented in situ formation of carbon monoxide from carbon dioxide and alcohols permits an efficient synthesis of carboxylic acid esters, which can be used as detergents and polymer-building blocks. Notably, this transformation allows the catalytic formation of C-C bonds with carbon dioxide as C1 source and avoids the use of sensitive and/or expensive reducing agents (for example, Grignard reagents, diethylzinc or triethylaluminum). PMID:24518431

  10. Adsorption and Desorption of Carbon Dioxide and Water Mixtures on Synthetic Hydrophobic Carbonaceous Adsorbents

    NASA Technical Reports Server (NTRS)

    Finn, John E.; Harper, Lynn D. (Technical Monitor)

    1994-01-01

    Several synthetic carbonaceous adsorbents produced through pyrolysis of polymeric materials are available commercially. Some appear to have advantages over activated carbon for certain adsorption applications. In particular, they can have tailored hydrophobicities that are significantly greater than that of activated carbon, while moderately high surfaces areas are retained. These sorbents are being investigated for possible use in removing trace contaminants and excess carbon dioxide from air in closed habitats, plant growth chambers, and other applications involving purification of humid gas streams. We have analyzed the characteristics of a few of these adsorbents through adsorption and desorption experiments and standard characterization techniques. This paper presents pure and multicomponent adsorption data collected for carbon dioxide and water on two synthetic carbonaceous adsorbents having different hydrophobicities and capillary condensation characteristics. The observations are interpreted through consideration of the pore structure and surface chemistry of the solids and interactions between adsorbed carbon dioxide, water, and the solvent gas.

  11. Carbon dioxide emission from bamboo culms.

    PubMed

    Zachariah, E J; Sabulal, B; Nair, D N K; Johnson, A J; Kumar, C S P

    2016-05-01

    Bamboos are one of the fastest growing plants on Earth, and are widely considered to have high ability to capture and sequester atmospheric carbon, and consequently to mitigate climate change. We tested this hypothesis by measuring carbon dioxide (CO2 ) emissions from bamboo culms and comparing them with their biomass sequestration potential. We analysed diurnal effluxes from Bambusa vulgaris culm surface and gas mixtures inside hollow sections of various bamboos using gas chromatography. Corresponding variations in gas pressure inside the bamboo section and culm surface temperature were measured. SEM micrographs of rhizome and bud portions of bamboo culms were also recorded. We found very high CO2 effluxes from culm surface, nodes and buds of bamboos. Positive gas pressure and very high concentrations of CO2 were observed inside hollow sections of bamboos. The CO2 effluxes observed from bamboos were very high compared to their carbon sequestration potential. Our measurements suggest that bamboos are net emitters of CO2 during their lifespan. PMID:26802362

  12. Global carbon dioxide emissions from inland waters

    USGS Publications Warehouse

    Raymond, Peter A.; Hartmann, Jens; Lauerwald, Ronny; Sobek, Sebastian; McDonald, Cory P.; Hoover, Mark; Butman, David; Striegl, Rob; Mayorga, Emilio; Humborg, Christoph; Kortelainen, Pirkko; Durr, Hans H.; Meybeck, Michel; Ciais, Philippe; Guth, Peter

    2013-01-01

    Carbon dioxide (CO2) transfer from inland waters to the atmosphere, known as CO2 evasion, is a component of the global carbon cycle. Global estimates of CO2 evasion have been hampered, however, by the lack of a framework for estimating the inland water surface area and gas transfer velocity and by the absence of a global CO2 database. Here we report regional variations in global inland water surface area, dissolved CO2 and gas transfer velocity. We obtain global CO2 evasion rates of 1.8   petagrams of carbon (Pg C) per year from streams and rivers and 0.32  Pg C yr−1 from lakes and reservoirs, where the upper and lower limits are respectively the 5th and 95th confidence interval percentiles. The resulting global evasion rate of 2.1 Pg C yr−1 is higher than previous estimates owing to a larger stream and river evasion rate. Our analysis predicts global hotspots in stream and river evasion, with about 70 per cent of the flux occurring over just 20 per cent of the land surface. The source of inland water CO2 is still not known with certainty and new studies are needed to research the mechanisms controlling CO2 evasion globally.

  13. Carbon dioxide removal with inorganic membranes

    SciTech Connect

    Judkins, R.R.; Fain, D.E.

    1993-12-31

    The increasing concentrations of greenhouse gases, particularly carbon dioxide, in the atmosphere has sparked a great deal of interest in the removal of CO{sub 2} from flue gases of fossil fueled plants. Presently, several techniques for the removal of CO{sub 2} are considered to have potential, but are lacking in practicality. For example, amine scrubbing of flue gas streams is potential, but are lacking in practically. For example, amine scrubbing of flue gas streams is effective in removing CO{sub 2}, but costs are high; efficiency suffers; and other acid gases must be removed prior to amine stripping. Membrane systems for CO{sub 2} removal are held in high regard, and inorganic, particularly ceramic, membranes offer the potential for high temperature, thus energy saving, removal.

  14. The Fluid Mechanics of Carbon Dioxide Sequestration

    NASA Astrophysics Data System (ADS)

    Huppert, Herbert E.; Neufeld, Jerome A.

    2014-01-01

    Humans are faced with a potentially disastrous global problem owing to the current emission of 32 gigatonnes of carbon dioxide (CO2) annually into the atmosphere. A possible way to mitigate the effects is to store CO2 in large porous reservoirs within the Earth. Fluid mechanics plays a key role in determining both the feasibility and risks involved in this geological sequestration. We review current research efforts looking at the propagation of CO2 within the subsurface, the possible rates of leakage, the mechanisms that act to stably trap CO2, and the geomechanical response of the crust to large-scale CO2 injection. We conclude with an outline for future research.

  15. Thermodynamical effects during carbon dioxide release

    NASA Astrophysics Data System (ADS)

    Singh, A. K.; Böttcher, N.; Görke, U.-J.; Kolditz, O.

    2012-04-01

    Pruess [1] investigated the risk of carbon dioxide leakage from shallow storage sites by modeling scenarios. Such a fluid release is associated with mechanical work performed by formation fluid against expansion without taking heat from ambient environment. Understanding of heat related to mechanical work is essential to predict the temperature at the leak. According to the first law of thermodynamics, internal energy of working fluid decreases with an amount which is equivalent to this work hence, working fluid lost its own heat. Such kind of heat loss depends strongly on whether the expansion process is adiabatic or isothermal. Isothermal expansion allows the working fluid to interact thermally with the solid matrix. Adiabatic expansion is an isenthalpic process that takes heat from the working fluid and the ambient environment remains unchanged. This work is part of the CLEAN research project [6]. In this study, thermodynamic effects of mechanical work during eventual carbon dioxide leakage are investigated numerically. In particular, we are interested to detect the temperature at leakage scenarios and its deviation with different thermodynamic processes. Finite element simulation is conducted with a two-dimensional rectangular geometry representing a shallow storage site which bottom was located at -300m below the land surface. A fully saturated porous medium is assumed where the pore space is filled completely with carbon dioxide. Carbon dioxide accumulated in the secondary trap at 30 Bar and 24 °C is allowed to leak from top right point of rectangle with atmospheric pressure. With (i) adiabatic and (ii) isothermal compressibility factors, temperature around leakage area has been calculated which show a significant difference. With some simplification, this study detects leak temperature which is very close with [1]. Temporal evaluation at the leaky area shows that the working fluid temperature can be reduced to -20 °C when the leakage scenario is performed

  16. Pulsed-discharge carbon dioxide lasers

    NASA Technical Reports Server (NTRS)

    Willetts, David V.

    1990-01-01

    The purpose is to attempt a general introduction to pulsed carbon dioxide lasers of the kind used or proposed for laser radar applications. Laser physics is an excellent example of a cross-disciplinary topic, and the molecular spectroscopy, energy transfer, and plasma kinetics of the devices are explored. The concept of stimulated emission and population inversions is introduced, leading on to the molecular spectroscopy of the CO2 molecule. This is followed by a consideration of electron-impact pumping, and the pertinent energy transfer and relaxation processes which go on. Since the devices are plasma pumped, it is necessary to introduce a complex subject, but this is restricted to appropriate physics of glow discharges. Examples of representative devices are shown. The implications of the foregoing to plasma chemistry and gas life are discussed.

  17. Layered solid sorbents for carbon dioxide capture

    SciTech Connect

    Li, Bingyun; Jiang, Bingbing; Gray, McMahan L; Fauth, Daniel J; Pennline, Henry W; Richards, George A

    2014-11-18

    A solid sorbent for the capture and the transport of carbon dioxide gas is provided having at least one first layer of a positively charged material that is polyethylenimine or poly(allylamine hydrochloride), that captures at least a portion of the gas, and at least one second layer of a negatively charged material that is polystyrenesulfonate or poly(acryclic acid), that transports the gas, wherein the second layer of material is in juxtaposition to, attached to, or crosslinked with the first layer for forming at least one bilayer, and a solid substrate support having a porous surface, wherein one or more of the bilayers is/are deposited on the surface of and/or within the solid substrate. A method of preparing and using the solid sorbent is provided.

  18. Biochemical Capture and Removal of Carbon Dioxide

    NASA Technical Reports Server (NTRS)

    Trachtenberg, Michael C.

    1998-01-01

    We devised an enzyme-based facilitated transport membrane bioreactor system to selectively remove carbon dioxide (CO2) from the space station environment. We developed and expressed site-directed enzyme mutants for CO2 capture. Enzyme kinetics showed the mutants to be almost identical to the wild type save at higher pH. Both native enzyme and mutant enzymes were immobilized to different supports including nylons, glasses, sepharose, methacrylate, titanium and nickel. Mutant enzyme could be attached and removed from metal ligand supports and the supports reused at least five times. Membrane systems were constructed to test CO2 selectivity. These included proteic membranes, thin liquid films and enzyme-immobilized teflon membranes. Selectivity ratios of more than 200:1 were obtained for CO2 versus oxygen with CO2 at 0.1%. The data indicate that a membrane based bioreactor can be constructed which could bring CO2 levels close to Earth.

  19. Dissociation-excitation reactions of argon metastables with carbon dioxide.

    NASA Technical Reports Server (NTRS)

    Starr, W. L.

    1971-01-01

    Results of a study showing that a metastable argon-carbon dioxide reaction results in dissociation of carbon dioxide and electronic excitation of one of the products, carbon monoxide or oxygen. A flow system using a 2450-MHz discharge was used to produce metastable argon atoms. Metastable argon in the afterglow was confirmed by adding nitrogen to the afterglow. Without addition of carbon dioxide no argon line emission, or any other emission, is observed from the reaction zone. Absence of argon line emission produced by recombination indicates the absence of charged species.

  20. Global food insecurity. Treatment of major food crops with elevated carbon dioxide or ozone under large-scale fully open-air conditions suggests recent models may have overestimated future yields

    PubMed Central

    Long, Stephen P; Ainsworth, Elizabeth A; Leakey, Andrew D.B; Morgan, Patrick B

    2005-01-01

    Predictions of yield for the globe's major grain and legume arable crops suggest that, with a moderate temperature increase, production may increase in the temperate zone, but decline in the tropics. In total, global food supply may show little change. This security comes from inclusion of the direct effect of rising carbon dioxide (CO2) concentration, [CO2], which significantly stimulates yield by decreasing photorespiration in C3 crops and transpiration in all crops. Evidence for a large response to [CO2] is largely based on studies made within chambers at small scales, which would be considered unacceptable for standard agronomic trials of new cultivars or agrochemicals. Yet, predictions of the globe's future food security are based on such inadequate information. Free-Air Concentration Enrichment (FACE) technology now allows investigation of the effects of rising [CO2] and ozone on field crops under fully open-air conditions at an agronomic scale. Experiments with rice, wheat, maize and soybean show smaller increases in yield than anticipated from studies in chambers. Experiments with increased ozone show large yield losses (20%), which are not accounted for in projections of global food security. These findings suggest that current projections of global food security are overoptimistic. The fertilization effect of CO2 is less than that used in many models, while rising ozone will cause large yield losses in the Northern Hemisphere. Unfortunately, FACE studies have been limited in geographical extent and interactive effects of CO2, ozone and temperature have yet to be studied. Without more extensive study of the effects of these changes at an agronomic scale in the open air, our ever-more sophisticated models will continue to have feet of clay. PMID:16433090

  1. Six-fold coordinated carbon dioxide VI.

    PubMed

    Iota, Valentin; Yoo, Choong-Shik; Klepeis, Jae-Hyun; Jenei, Zsolt; Evans, William; Cynn, Hyunchae

    2007-01-01

    Under standard conditions, carbon dioxide (CO2) is a simple molecular gas and an important atmospheric constituent, whereas silicon dioxide (SiO2) is a covalent solid, and one of the fundamental minerals of the planet. The remarkable dissimilarity between these two group IV oxides is diminished at higher pressures and temperatures as CO2 transforms to a series of solid phases, from simple molecular to a fully covalent extended-solid V, structurally analogous to SiO2 tridymite. Here, we present the discovery of an extended-solid phase of CO2: a six-fold coordinated stishovite-like phase VI, obtained by isothermal compression of associated CO2-II (refs 1,2) above 50 GPa at 530-650 K. Together with the previously reported CO2-V (refs 3-5) and a-carbonia, this extended phase indicates a fundamental similarity between CO2 (a prototypical molecular solid) and SiO2 (one of Earth's fundamental building blocks). We present a phase diagram with a limited stability domain for molecular CO2-I, and suggest that the conversion to extended-network solids above 40-50 GPa occurs via intermediate phases II (refs 1,2), III (refs 7,8) and IV (refs 9,10). The crystal structure of phase VI suggests strong disorder along the c axis in stishovite-like P42/mnm, with carbon atoms manifesting an average six-fold coordination within the framework of sp3 hybridization. PMID:17160005

  2. Coiled tubing drilling with supercritical carbon dioxide

    DOEpatents

    Kolle , Jack J.

    2002-01-01

    A method for increasing the efficiency of drilling operations by using a drilling fluid material that exists as supercritical fluid or a dense gas at temperature and pressure conditions existing at a drill site. The material can be used to reduce mechanical drilling forces, to remove cuttings, or to jet erode a substrate. In one embodiment, carbon dioxide (CO.sub.2) is used as the material for drilling within wells in the earth, where the normal temperature and pressure conditions cause CO.sub.2 to exist as a supercritical fluid. Supercritical carbon dioxide (SC--CO.sub.2) is preferably used with coiled tube (CT) drilling equipment. The very low viscosity SC--CO.sub.2 provides efficient cooling of the drill head, and efficient cuttings removal. Further, the diffusivity of SC--CO.sub.2 within the pores of petroleum formations is significantly higher than that of water, making jet erosion using SC--CO.sub.2 much more effective than water jet erosion. SC--CO.sub.2 jets can be used to assist mechanical drilling, for erosion drilling, or for scale removal. A choke manifold at the well head or mud cap drilling equipment can be used to control the pressure within the borehole, to ensure that the temperature and pressure conditions necessary for CO.sub.2 to exist as either a supercritical fluid or a dense gas occur at the drill site. Spent CO.sub.2 can be vented to the atmosphere, collected for reuse, or directed into the formation to aid in the recovery of petroleum.

  3. Heliox administration during high-frequency jet ventilation augments carbon dioxide clearance.

    PubMed

    Gupta, Vineet K; Grayck, Eva N; Cheifetz, Ira M

    2004-09-01

    We report the combined use of heliox and high-frequency jet ventilation to augment carbon dioxide clearance, with a focus on the important technical considerations. Our case is a 5-month old infant with acute respiratory failure associated with gas trapping, hypercarbia, respiratory acidosis, and air leak. Despite maximal conventional ventilation, bronchodilator therapy, corticosteroids, and sedation, the infant continued to demonstrate worsening gas exchange necessitating an escalation of support to high-frequency oscillatory ventilation. After the development of an air leak and continued difficulties with carbon dioxide clearance, the patient was transitioned to high-frequency jet ventilation. Persistent hypercarbia resulted in the addition of heliox to facilitate ventilation. Improvements in gas exchange occurred rapidly. The combination of heliox and high frequency jet ventilation resulted in improved carbon dioxide clearance, respiratory stabilization, and the ability to wean ventilator settings. PMID:15329176

  4. Self-Cleaning Boudouard Reactor for Full Oxygen Recovery from Carbon Dioxide

    NASA Technical Reports Server (NTRS)

    Coutts, Janelle; Hintze, Paul E.; Muscatello, Anthony C.; Gibson, Tracy L.; Captain, James G.; Lunn, Griffin M.; Devor, Robert W.; Bauer, Brint; Parks, Steve

    2016-01-01

    Oxygen recovery from respiratory carbon dioxide is an important aspect of human spaceflight. Methods exist to sequester the carbon dioxide, but production of oxygen needs further development. The current International Space Station Carbon Dioxide Reduction System (CRS) uses the Sabatier reaction to produce water (and ultimately breathing air). Oxygen recovery is limited to 50 because half of the hydrogen used in the Sabatier reactor is lost as methane, which is vented overboard. The Bosch reaction, which converts carbon dioxide to oxygen and solid carbon is capable of recovering all the oxygen from carbon dioxide, and is the only real alternative to the Sabatier reaction. However, the last reaction in the cycle, the Boudouard reaction, produces solid carbon and the resulting carbon buildup will eventually foul the nickel or iron catalyst, reducing reactor life and increasing consumables. To minimize this fouling and increase efficiency, a number of self-cleaning catalyst designs have been created. This paper will describe recent results evaluating one of the designs.

  5. Self-Cleaning Boudouard Reactor for Full Oxygen Recovery from Carbon Dioxide

    NASA Technical Reports Server (NTRS)

    Hintze, Paul E.; Muscatello, Anthony C.; Meier, Anne J.; Gibson, Tracy L.; Captain, James G.; Lunn, Griffin M.; Devor, Robert W.

    2016-01-01

    Oxygen recovery from respiratory carbon dioxide is an important aspect of human spaceflight. Methods exist to sequester the carbon dioxide, but production of oxygen needs further development. The current International Space Station Carbon Dioxide Reduction System (CRS) uses the Sabatier reaction to produce water (and ultimately breathing air). Oxygen recovery is limited to 50% because half of the hydrogen used in the Sabatier reactor is lost as methane, which is vented overboard. The Bosch reaction, which converts carbon dioxide to oxygen and solid carbon is capable of recovering all the oxygen from carbon dioxide, and is the only real alternative to the Sabatier reaction. However, the last reaction in the cycle, the Boudouard reaction, produces solid carbon and the resulting carbon buildup will eventually foul the nickel or iron catalyst, reducing reactor life and increasing consumables. To minimize this fouling and increase efficiency, a number of self-cleaning catalyst designs have been created. This paper will describe recent results evaluating one of the designs.

  6. Intraosseous Venography with Carbon Dioxide in Percutaneous Vertebroplasty: Carbon Dioxide Retention in Renal Veins

    SciTech Connect

    Komemushi, Atsushi Tanigawa, Noboru; Kariya, Shuji; Kojima, Hiroyuki; Shomura, Yuzo; Tokuda, Takanori; Nomura, Motoo; Terada, Jiro; Kamata, Minoru; Sawada, Satoshi

    2008-11-15

    The objective of the present study was to determine the frequency of gas retention in the renal vein following carbon dioxide intraosseous venography in the prone position and, while citing references, to examine its onset mechanisms. All percutaneous vertebroplasties performed at our hospital from January to December 2005 were registered and retrospectively analyzed. Of 43 registered procedures treating 79 vertebrae, 28 procedures treating 54 vertebrae were analyzed. Vertebral intraosseous venography was performed using carbon dioxide as a contrast agent in all percutaneous vertebroplasty procedures. In preoperative and postoperative vertebral CT, gas retention in the renal vein and other areas was assessed. Preoperative CT did not show gas retention (0/28 procedures; 0%). Postoperative CT confirmed gas retention in the renal vein in 10 of the 28 procedures (35.7%). Gas retention was seen in the right renal vein in 8 procedures (28.6%), in the left renal vein in 5 procedures (17.9%), in the left and right renal veins in 3 procedures (10.7%), in vertebrae in 22 procedures (78.6%), in the soft tissue around vertebrae in 14 procedures (50.0%), in the spinal canal in 12 procedures (42.9%), and in the subcutaneous tissue in 5 procedures (17.9%). In conclusion, in our study, carbon dioxide gas injected into the vertebra frequently reached and remained in the renal vein.

  7. The vitiation effects of water vapor and carbon dioxide on the autoignition characteristics of kerosene

    NASA Astrophysics Data System (ADS)

    Liang, Jin-Hu; Wang, Su; Zhang, Sheng-Tao; Yue, Lian-Jie; Fan, Bing-Cheng; Zhang, Xin-Yu; Cui, Ji-Ping

    2014-08-01

    In ground tests of hypersonic scramjet, the high-enthalpy airstream produced by burning hydrocarbon fuels often contains contaminants of water vapor and carbon dioxide. The contaminants may change the ignition characteristics of fuels between ground tests and real flights. In order to properly assess the influence of the contaminants on ignition characteristics of hydrocarbon fuels, the effect of water vapor and carbon dioxide on the ignition delay times of China RP-3 kerosene was studied behind reflected shock waves in a preheated shock tube. Experiments were conducted over a wider temperature range of 800-1 500K, at a pressure of 0.3 MPa, equivalence ratios of 0.5 and 1, and oxygen concentration of 20%. Ignition delay times were determined from the onset of the excited radical OH emission together with the pressure profile. Ignition delay times were measured for four cases: (1) clean gas, (2) gas vitiated with 10% and 20% water vapor in mole, (3) gas vitiated with 10% carbon dioxide in mole, and (4) gas vitiated with 10% water vapor and 10% carbon dioxide, 20% water vapor and 10% carbon dioxide in mole. The results show that carbon dioxide produces an inhibiting effect at temperatures below 1 300 K when ϕ = 0.5, whereas water vapor appears to accelerate the ignition process below a critical temperature of about 1 000 K when ϕ = 0.5. When both water vapor and carbon dioxide exist together, a minor inhibiting effect is observed at ϕ = 0.5, while no effect is found at ϕ = 1.0. The results are also discussed preliminary by considering both the combustion reaction mechanism and the thermophysics properties of the fuel mixtures. The current measurements demonstrate vitiation effects of water vapor and carbon dioxide on the autoignition characteristics of China RP-3 kerosene at air-like O2 concentration. It is important to account for such effects when data are extrapolated from ground testing to real flight conditions.

  8. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Brian S. Turk; Jeffrey W. Portzer; Thomas Nelson; Raghubir P. Gupta

    2005-01-01

    This report describes research conducted between October 1, 2004 and December 31, 2004 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas. Two supported sorbents were tested in a bench scale fluidized bed reactor system. The sorbents were prepared by impregnation of sodium carbonate on to an inert support at a commercial catalyst manufacturing facility. One sorbent, tested through five cycles of carbon dioxide sorption in an atmosphere of 3% water vapor and 0.8 to 3% carbon dioxide showed consistent reactivity with sodium carbonate utilization of 7 to 14%. A second, similarly prepared material, showed comparable reactivity in one cycle of testing. Batches of 5 other materials were prepared in laboratory scale quantities (primarily by spray drying). These materials generally have significantly greater surface areas than calcined sodium bicarbonate. Small scale testing showed no significant adsorption of mercury on representative carbon dioxide sorbent materials under expected flue gas conditions.

  9. Carbon dioxide exchange and growth of a pine plantation

    SciTech Connect

    Murphy, Jr, C E

    1981-01-01

    The exchange of materials between the atmosphere and terrestrial ecosystem is important to an understanding of the cycling of essential elements, the deposition of mateials from the atmosphere and the entrance of pollutants into the forest ecosystems. This paper reports the results of measurements of carbon dioxide exchange in a vigorously growing pine plantation. Measurement data were incorporated into a model used to estimate annual carbon dioxide exchange and measured annual biomass accumulation in the same plantation were used to determine a carbon dioxide to biomass conversion efficiency. Carbon dioxide exchange was 10.5 metric tons per hectare and biomass accumulation was 4.5 metric tons per hectare. The conversion efficiency of cabon dioxide to biomass is about 25% less than the theoretical chemical conversion efficiency. 27 refs., 8 figs.

  10. Testing a Regenerative Carbon Dioxide and Moisture Removal Technology

    NASA Technical Reports Server (NTRS)

    Barta, Daniel J.; Button, Amy; Sweterlitsch, Jeffrey J.; Curley, Suzanne

    2010-01-01

    The National Aeronautics and Space Administration supported the development of a new vacuum-desorbed regenerative carbon dioxide and humidity control technology for use in short duration human spacecraft. The technology was baselined for use in the Orion Crew Exploration Vehicle s Environmental Control and Life Support System (ECLSS). Termed the Carbon Dioxide And Moisture Removal Amine Swing-bed (CAMRAS), the unit was developed by Hamilton Sundstrand and has undergone extensive testing at Johnson Space Center. The tests were performed to evaluate performance characteristics under range of operating conditions and human loads expected in future spacecraft applications, as part of maturation to increase its readiness for flight. Early tests, conducted at nominal atmospheric pressure, used human metabolic simulators to generate loads, with later tests making us of human test subjects. During these tests many different test cases were performed, involving from 1 to 6 test subjects, with different activity profiles (sleep, nominal and exercise). These tests were conducted within the airlock portion of a human rated test chamber sized to simulate the Orion cabin free air volume. More recently, a test was completed that integrated the CAMRAS with a simulated suit loop using prototype umbilicals and was conducted at reduced atmospheric pressure and elevated oxygen levels. This paper will describe the facilities and procedures used to conduct these and future tests, and provide a summary of findings.

  11. Testing a Regenerative Carbon Dioxide and Moisture Removal Technology

    NASA Astrophysics Data System (ADS)

    Barta, Daniel J.; Button, Amy; Sweterlitsch, Jeffrey; Curley, Suzanne

    The National Aeronautics and Space Administration supported the development of a new vacuum-desorbed regenerative carbon dioxide and humidity control technology for use in short duration human spacecraft. The technology was baselined for use in the Orion Crew Exploration Vehicle's Environmental Control and Life Support System (ECLSS). Termed the Carbon Diox-ide And Moisture Removal Amine Swing-bed (CAMRAS), the unit was developed by Hamilton Sundstrand and has undergone extensive testing at Johnson Space Center. The tests were per-formed to evaluate performance characteristics under range of operating conditions and human loads expected in future spacecraft applications, as part of maturation to increase its readiness for flight. Early tests, conducted at nominal atmospheric pressure, used human metabolic sim-ulators to generate loads, with later tests making us of human test subjects. During these tests many different test cases were performed, involving from 1 to 6 test subjects, with different activity profiles (sleep, nominal and exercise). These tests were conducted within the airlock portion of a human rated test chamber sized to simulate the Orion cabin free air volume. More recently, a test was completed that integrated the CAMRAS with a simulated suit loop using prototype umbilicals and was conducted at reduced atmospheric pressure and elevated oxygen levels. This paper will describe the facilities and procedures used to conduct these and future tests, and provide a summary of findings.

  12. Experimental fractionation of stable carbon isotopes during degassing of carbon dioxide and precipitation of calcite from aqueous solutions

    NASA Astrophysics Data System (ADS)

    Müller, K.; Winde, V.; Escher, P.; von Geldern, R.; Böttcher, M. E.

    2012-04-01

    Processes in the carbonate system of surface waters are in particular sensitive to variations of boundary conditions as, for instance, the partial pressure of carbon dioxide in the atmosphere and the aqueous solution. Examples range from streams, rivers, to coastal marine waters. The flux of carbon dioxide from continental flowing waters was recently included into calculations of the global carbon budget (Butman & Raymond, 2011, Nature Geo.). These solutions, are often supersaturated in carbon dioxide with respect to the atmosphere. The degassing of carbon dioxide is associated with a kinetically controlled fractionation of the stable carbon isotopes, which has to be considered in balancing water-air carbon dioxide fluxes. The degassing process additionally leads to the super-saturation of the aqueous solution with respect to calcium carbonate. Stable isotope fractionation is of particular value to identify and quantify processes at the water-gas phase interface and link these non-equilibrium processes to the formation mechanisms of calcite and the hydrodynamics of surface waters. Experiments were carried out with or without inert N2 gas flow to degas carbon dioxide from initially supersaturated solutions. Natural solutions used are from different stations of the Elbe estuary, the Jade Bay, the backbarrier tidal area of Spiekeroog Island, carbonate springs of Rügen Island, and the Baltic Sea coastline. Results are compared experiments using bottled mineral waters. By following the (physico) chemical changes in the solutions (pH, TA, Ca PHREEQC modeling) it was found, that two evolutionary stages can be differentiated. Reaction progress led to the preferential liberation of carbon dioxide containing the light carbon isotope, following a Rayleigh-type process. After an induction period, where only degassing of carbon dioxide took place, a second stage was observed where calcite began to form from the highly supersaturated solutions. In this stage the carbonate

  13. 75 FR 29534 - Inorganic Nitrates-Nitrite, Carbon and Carbon Dioxide, and Sulfur Registration Review; Draft...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-26

    ... AGENCY Inorganic Nitrates-Nitrite, Carbon and Carbon Dioxide, and Sulfur Registration Review; Draft... draft ecological risk assessment for the registration review of inorganic nitrates - nitrites, carbon and carbon dioxide, and gas cartridge uses of sulfur, and opens a public comment period on...

  14. Herbivore responses to plants grown in enriched carbon dioxide atmospheres

    SciTech Connect

    Lincoln, D.E.

    1990-05-01

    Our initial study of sagebrush and grasshopper responses to elevated and historical carbon dioxide atmospheres is complete and has been accepted for publication. The study on Biomass Allocation Patterns of Defoliated Sagebrush Grown Under Two Levels of Carbon Dioxide has completed and the manuscript has been submitted for publication. We have completed the study of plant growth under two nutrient and carbon dioxide regimes and grasshopper feeding responses. The study of a specialist feeding caterpillar, the cabbage butterfly, and a mustard hostplant has recently been completed. We were able to identify the principal allelochemicals of the mustard plants, butenyl and pentenyl isothiocyanates, by combined gas chromatography and mass spectrometry. Measurement of these chemicals has been a critical component of this study since these compounds contain nitrogen and sulphur and act as a feeding stimulant to the caterpillar. This insect responds to elevated carbon dioxide by consuming more leaves and we can now say that this is not due to a change in the feeding stimulants. Reduced leaf protein content is a critical factor for even specialist feeding insect herbivores under elevated carbon dioxide conditions. The study on Grasshopper Population Responses to Enriched Carbon Dioxide Concentration is currently in progress at the Duke University Phytotron. We have changed hostplant species in order to complement the investigations of carbon dioxide effects on tallgrass prairie. Specifically, we are using big bluestem, Andropogon geradii, as the host plant to feed to the grasshoppers. This experiment will be completed in July 1990.

  15. Forest management techniques for carbon dioxide storage

    SciTech Connect

    Fujimori, Takao

    1993-12-31

    In the global ecosystem concerning carbon dioxide content in the atmosphere, the forest ecosystem plays an important role. In effect, the ratio of forest biomass to total terrestrial biomass is about 90%, and the ratio of carbon stored in the forest biomass to that in the atmosphere is two thirds. When soils and detritus of forests are added, there is more C stored in forests than in the atmosphere, about 1.3 times or more. Thus, forests can be regarded as the great holder of C on earth. If the area of forest land on the earth is constantly maintained and forests are in the climax stage, the uptake of C and the release of C by and from the forests will balance. In this case, forests are neither sinks nor sources of CO{sub 2} although they store a large amount of C. However, when forests are deforested, they become a source of C; through human activities, forests have become a source of C. According to a report by the IPCC, 1.6{+-}1.2 PgC is annually added to the atmosphere by deforestation. According to the FAO (1992), the area of land deforested annually in the tropics from 1981 to 1990 was 16.9 x 10{sup 6} ha. This value is nearly half the area of Japanese land. The most important thing for the CO{sub 2} environment concerning forests is therefore how to reduce deforestation and to successfully implement a forestation or reforestation.

  16. Carbon dioxide warming of the early Earth.

    PubMed

    Arrhenius, G

    1997-02-01

    Svante Arrhenius' research in atmospheric physics extended beyond the recent past and the near future states of the Earth, which today are at the center of sociopolitical attention. His plan encompassed all of the physical phenomena known at the time to relate to the formation and evolution of stars and planets. His two-volume textbook on cosmic physics is a comprehensive synopsis of the field. The inquiry into the possible cause of the ice ages and the theory of selective wavelength filter control led Arrhenius to consider the surface states of the other terrestrial planets, and of the ancient Earth before it had been modified by the emergence of life. The rapid escape of hydrogen and the equilibration with igneous rocks required that carbon in the early atmosphere prevailed mainly in oxidized form as carbon dioxide, together with other photoactive gases exerting a greenhouse effect orders of magnitude larger than in our present atmosphere. This effect, together with the ensuing chemical processes, would have set the conditions for life to evolve on our planet, seeded from spores spreading through an infinite Universe, and propelled, as Arrhenius thought, by stellar radiation pressure. PMID:11541253

  17. Carbon dioxide warming of the early Earth

    NASA Technical Reports Server (NTRS)

    Arrhenius, G.

    1997-01-01

    Svante Arrhenius' research in atmospheric physics extended beyond the recent past and the near future states of the Earth, which today are at the center of sociopolitical attention. His plan encompassed all of the physical phenomena known at the time to relate to the formation and evolution of stars and planets. His two-volume textbook on cosmic physics is a comprehensive synopsis of the field. The inquiry into the possible cause of the ice ages and the theory of selective wavelength filter control led Arrhenius to consider the surface states of the other terrestrial planets, and of the ancient Earth before it had been modified by the emergence of life. The rapid escape of hydrogen and the equilibration with igneous rocks required that carbon in the early atmosphere prevailed mainly in oxidized form as carbon dioxide, together with other photoactive gases exerting a greenhouse effect orders of magnitude larger than in our present atmosphere. This effect, together with the ensuing chemical processes, would have set the conditions for life to evolve on our planet, seeded from spores spreading through an infinite Universe, and propelled, as Arrhenius thought, by stellar radiation pressure.

  18. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Thomas Nelson; Brian S. Turk; Paul Box; Weijiong Li; Raghubir P. Gupta

    2005-07-01

    This report describes research conducted between April 1, 2005 and June 30, 2005 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas from coal combustion and synthesis gas from coal gasification. Supported sodium carbonate sorbents removed up to 76% of the carbon dioxide from simulated flue gas in a downflow cocurrent flow reactor system, with an approximate 15 second gas-solid contact time. This reaction proceeds at temperatures as low as 25 C. Lithium silicate sorbents remove carbon dioxide from high temperature simulated flue gas and simulated synthesis gas. Both sorbent types can be thermally regenerated and reused. The lithium silicate sorbent was tested in a thermogravimetric analyzer and in a 1-in quartz reactor at atmospheric pressure; tests were also conducted at elevated pressure in a 2-in diameter high temperature high pressure reactor system. The lithium sorbent reacts rapidly with carbon dioxide in flue gas at 350-500 C to absorb about 10% of the sorbent weight, then continues to react at a lower rate. The sorbent can be essentially completely regenerated at temperatures above 600 C and reused. In atmospheric pressure tests with synthesis gas of 10% initial carbon dioxide content, the sorbent removed over 90% of the carbon dioxide. An economic analysis of a downflow absorption process for removal of carbon dioxide from flue gas with a supported sodium carbonate sorbent suggests that a 90% efficient carbon dioxide capture system installed at a 500 MW{sub e} generating plant would have an incremental capital cost of $35 million ($91/kWe, assuming 20 percent for contingencies) and an operating cost of $0.0046/kWh. Assuming capital costs of $1,000/kW for a 500 MWe plant the capital cost of the down flow absorption process represents a less than 10% increase, thus meeting DOE goals as set forth in its Carbon Sequestration Technology Roadmap and Program Plan.

  19. Alkali metal carbon dioxide electrochemical system for energy storage and/or conversion of carbon dioxide to oxygen

    NASA Technical Reports Server (NTRS)

    Hagedorn, Norman H. (Inventor)

    1993-01-01

    An alkali metal, such as lithium, is the anodic reactant; carbon dioxide or a mixture of carbon dioxide and carbon monoxide is the cathodic reactant; and carbonate of the alkali metal is the electrolyte in an electrochemical cell for the storage and delivery of electrical energy. Additionally, alkali metal-carbon dioxide battery systems include a plurality of such electrochemical cells. Gold is a preferred catalyst for reducing the carbon dioxide at the cathode. The fuel cell of the invention produces electrochemical energy through the use of an anodic reactant which is extremely energetic and light, and a cathodic reactant which can be extracted from its environment and therefore exacts no transportation penalty. The invention is, therefore, especially useful in extraterrestrial environments.

  20. Low Energy, Low Emissions: Sulfur Dioxide; Nitrogen Oxides, and Carbon Dioxide in Western Europe.

    ERIC Educational Resources Information Center

    Alcamo, Joseph; De Vries, Bert

    1992-01-01

    Links proposed low-energy scenarios for different Western European countries with the amount of pollutants that may result from these scenarios. Sulfur dioxide, nitrogen oxide, and carbon dioxide emissions are calculated for the 10 countries for which low-energy scenarios are available, resulting in reductions of 54%, 37%, and 40%, respectively.…

  1. The rise and fall of carbon dioxide: Why controlling CO2 may be necessary in greenhouses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the winter production cycle, many of us focus on sealing up gaps in an effort to decrease air infiltration, and cut our heating bills substantially along the way. While making these changes or upgrades, we ignoring something the potential impact this has on carbon dioxide (CO2) and plant growth. ...

  2. Carbon Dioxide Flooding: A Classroom Case Study Derived from Surgical Practice

    NASA Astrophysics Data System (ADS)

    Kerber, Robert C.

    2003-12-01

    The surgical opening in open-heart surgery is often flooded with carbon dioxide gas to avoid air embolisms when the heart is closed and restarted. This practice can be used in chemistry courses to illustrate concepts of gas density, solubility, and acid base equilibria, including buffering.

  3. HAND-HELD SENSOR FOR REMOTELY MAPPING CARBON DIOXIDE POLLUTION SOURCES - PHASE I

    EPA Science Inventory

    In 2007, the U.S. Supreme Court ruled that carbon dioxide (CO2) is a pollutant under the federal Clean Air Act.  The ruling allows the U.S. Environmental Protection Agency (EPA) to regulate CO2 emissions.  Such regulation will entail monitoring a wid...

  4. Separation of Carbon Monoxide and Carbon Dioxide for Mars ISRU

    NASA Technical Reports Server (NTRS)

    Walton, Krista S.; LeVan, M. Douglas

    2004-01-01

    The atmosphere of Mars has many resources that can be processed to produce things such as oxygen, fuel, buffer gas, and water for support of human exploration missions. Successful manipulation of these resources is crucial for safe, cost-effective, and self-sufficient long-term human exploration of Mars. In our research, we are developing enabling technologies that require fundamental knowledge of adsorptive gas storage and separation processes. In particular, we are designing and constructing an innovative, low mass, low power separation device to recover carbon dioxide and carbon monoxide for Mars ISRU (in-situ resource utilization). The technology has broad implications for gas storage and separations for gas-solid systems that are ideally suited for reduced gravitational environments. This paper describes our separation process design and experimental procedures and reports results for the separation of CO2 and CO by a four-step adsorption cycle.

  5. Temperature Dependences for Air-broadened Widths and Shift Coefficients in the 30013 - 00001 and 30012 - 00001 Bands of Carbon Dioxide near 1600 nm

    NASA Astrophysics Data System (ADS)

    Devi, M.; Predoi-Cross, A.; McKellar, R.; Benner, C.; Miller, C. E.; Toth, R. A.; Brown, L. R.

    2008-12-01

    Nearly 40 high resolution spectra of air-broadened CO2 recorded at temperatures between 215 and 294 K were analyzed using a multispectrum nonlinear least squares technique to determine temperature dependences of air-broadened half width and air-induced pressure shift coefficients in the 30013-00001 and 30012-00001 bands of 12CO2. Data were recorded with two different Fourier transform spectrometers (Kitt Peak FTS at the National Solar Observatory in Arizona and the Bomem FTS at NRC, Ottawa) with optical path lengths ranging between 25 m and 121 m. The sample pressures varied between 11 torr (pure CO2) and 924 torr (CO2-air) with volume mixing ratios of CO2 in air between ~ 0.015 and 0.11. To minimize systematic errors and increase the accuracy of the retrieved parameters, we constrained the multispectrum nonlinear least squares fittings to use quantum mechanical expressions for the rovibrational energies and intensities rather than retrieving the individual positions and intensities line-by-line. The results suggest minimal vibrational dependence for the temperature dependence coefficients.1 1 A. Predoi-Cross and R. Mckellar are grateful for financial support from the National Sciences and Engineering Research Council of Canada. The research at the Jet Propulsion laboratory (JPL), California Institute of Technology, was performed under contract with National Aeronautics and Space Administration. The support received from the National Science Foundation under Grant No. ATM-0338475 to the College of William and Mary is greatly appreciated. The authors thank Mike Dulick of the National Solar Observatory for his assistance in obtaining the data recorded at Kitt Peak.

  6. Membranes for separation of carbon dioxide

    DOEpatents

    Ku, Anthony Yu-Chung; Ruud, James Anthony; Ramaswamy, Vidya; Willson, Patrick Daniel; Gao, Yan

    2011-03-01

    Methods for separating carbon dioxide from a fluid stream at a temperature higher than about 200.degree. C. with selectivity higher than Knudsen diffusion selectivity include contacting a porous membrane with the fluid stream to preferentially transport carbon dioxide. The porous membrane includes a porous support and a continuous porous separation layer disposed on a surface of the porous support and extending between the fluid stream and the porous support layer. The porous support comprises alumina, silica, zirconia, stabilized zirconia, stainless steel, titanium, nickel-based alloys, aluminum-based alloys, zirconium-based alloys or a combination thereof. Median pore size of the porous separation layer is less than about 10 nm, and the porous separation layer comprises titania, MgO, CaO, SrO, BaO, La.sub.2O.sub.3, CeO.sub.2, HfO.sub.2, Y.sub.2O.sub.3, VO.sub.z, NbO.sub.z, TaO.sub.z, ATiO.sub.3, AZrO.sub.3, AAl.sub.2O.sub.4, A.sup.1FeO.sub.3, A.sup.1MnO.sub.3, A.sup.1CoO.sub.3, A.sup.1NiO.sub.3, A.sup.2HfO.sub.3, A.sup.3 CeO.sub.3, Li.sub.2ZrO.sub.3, Li.sub.2SiO.sub.3, Li.sub.2TiO.sub.3, Li.sub.2HfO.sub.3, A.sup.4N.sup.1.sub.yO.sub.z, Y.sub.xN.sup.1.sub.yO.sub.z, La.sub.xN.sup.1.sub.yO.sub.z, HfN.sup.2.sub.yO.sub.z, or a combination thereof; wherein A is La, Mg, Ca, Sr or Ba; A.sup.1 is La, Ca, Sr or Ba; A.sup.2 is Ca, Sr or Ba; A.sup.3 is Sr or Ba; A.sup.4 is Mg, Ca, Sr, Ba, Ti or Zr; N.sup.1 is V, Nb, Ta, Cr, Mo, W, Mn, Si or Ge; N.sup.2 is V, Mo, W or Si; x is 1 or 2; y ranges from 1 to 3; and z ranges from 2 to 7.

  7. Atmospheric carbon dioxide: its role in maintaining phytoplankton standing crops.

    PubMed

    Schindler, D W; Brunskill, G J; Emerson, S; Broecker, W S; Peng, T H

    1972-09-29

    The rate of invasion of carbon dioxide into an artificially eutrophic Canadian Shield lake with insufficient internal sources of carbon was determined by two methods: measuring the carbon : nitrogen : phosphorus ratios of seston after weekly additions of nitrogen and phosphorus, and measuring the loss of radon-222 tracer from the epilimnion. Both methods gave an invasion rate of about 0.2 gram of carbon per square meter per day. The results demonstrate that invasion of atmospheric carbon dioxide may be sufficient to permit eutrophication of any body of water receiving an adequate supply of phosphorus and nitrogen. PMID:5057624

  8. PHENOLIC CONTENT AND ANTIOXIDANT ACTIVITY OF SUPERCRITICAL CARBON DIOXIDE TREATED AND AIR-CLASSIFIED OAT BRAN CONCENTRATE MICROWAVE-IRRADIATED IN SOLVENTS AT VARYING TEMPERATURES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In addition to health-beneficial beta-glucans, oats contain phenolic compounds (PC) and other antioxidant activity (AA). We investigated processing technologies to produce oat ingredients with concentrated levels of PC and AA. Oat bran concentrate (OBC) had lipids removed by supercritical carbon d...

  9. Carbon ion pump for removal of carbon dioxide from combustion gas and other gas mixtures

    DOEpatents

    Aines, Roger D.; Bourcier, William L.

    2014-08-19

    A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

  10. Carbon ion pump for removal of carbon dioxide from combustion gas and other gas mixtures

    DOEpatents

    Aines, Roger D.; Bourcier, William L.

    2010-11-09

    A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

  11. On the importance of high-frequency air-temperature fluctuations for spectroscopic corrections of open-path carbon dioxide flux measurements

    NASA Astrophysics Data System (ADS)

    Bogoev, Ivan; Helbig, Manuel; Sonnentag, Oliver

    2015-04-01

    A growing number of studies report systematic differences in CO2 flux estimates obtained with the two main types of gas analyzers: compared to eddy-covariance systems based on closed-path (CP) gas analyzers, systems with open-path (OP) gas analyzers systematically overestimate CO2 uptake during daytime periods with high positive sensible heat fluxes, while patterns for differences in nighttime CO2 exchange are less obvious. These biases have been shown to correlate with the sign and the magnitude of the sensible heat flux and to introduce large uncertainties when calculating annual CO2 budgets. In general, CP and OP gas analyzers commonly used to measure the CO2 density in the atmosphere operate on the principle of infrared light absorption approximated by Beer-Lambert's law. Non-dispersive interference-based optical filter elements are used to select spectral bands with strong attenuation of light transmission, characteristic to the gas of interest. The intensity of the light passing through the optical sensing path depends primarily on the amount of absorber gas in the measurement volume. Besides the density of the gas, barometric pressure and air temperature are additional factors affecting the strength and the half-width of the absorption lines. These so-called spectroscopic effects are accounted for by measuring barometric pressure and air temperature in the sensing path and scaling the light-intensity measurements before applying the calibration equation. This approach works well for CP gas analyzers with an intake tube that acts as a low-pass filter on fast air-temperature fluctuations. Low-frequency response temperature sensors in the measurement cell are therefore sufficient to account for spectroscopic temperature effects. In contrast, OP gas analyzers are exposed to high-frequency air-temperature fluctuations associated with the atmospheric surface-layer turbulent heat exchange. If not corrected adequately, these fast air-temperature variations can cause

  12. Pretreatment for cellulose hydrolysis by carbon dioxide explosion

    SciTech Connect

    Zheng, Y.; Lin, H.M.; Tsao, G.T.

    1998-11-01

    Cellulosic materials were treated with supercritical carbon dioxide to increase the reactivity of cellulose, thereby to enhance the rate and the extent of cellulose hydrolysis. In this pretreatment process, the cellulosic materials such as Avicel, recycled paper mix, sugarcane bagasse and the repulping waste of recycled paper are placed in a reactor under pressurized carbon dioxide at 35 C for a controlled time period. Upon an explosive release of the carbon dioxide pressure, the disruption of the cellulosic structure increases the accessible surface area of the cellulosic substrate to enzymatic hydrolysis. Results indicate that supercritical carbon dioxide is effective for pretreatment of cellulose. An increase in pressure facilitates the faster penetration of carbon dioxide molecules into the crystalline structures, thus more glucose is produced from cellulosic materials after the explosion as compared to those without the pretreatment. This explosion pretreatment enhances the rate of cellulosic material hydrolysis as well as increases glucose yield by as much as 50%. Results from the simultaneous saccharification and fermentation tests also show the increase in the available carbon source from the cellulosic materials for fermentation to produce ethanol. As an alternative method, this supercritical carbon dioxide explosion has a possibility to reduce expense compared with ammonia explosion, and since it is operated at the low temperature, it will not cause degradation of sugars such as those treated with steam explosion due to the high-temperature involved.

  13. An abrupt reduction in end-tidal carbon-dioxide during neurosurgery is not always due to venous air embolism: a capnograph artefact.

    PubMed

    Vinay, Byrappa; Sriganesh, Kamath; Gopala Krishna, Kadarapura Nanjundaiah

    2014-04-01

    Venous air embolism (VAE) is a well recognized complication during neurosurgery. Pre-cordial doppler and trans-esophageal echocardiography are sensitive monitors for the detection of VAE. A sudden, abrupt reduction in the end-tidal carbondioxide (ETCO2) pressure with associated hypotension during neurosurgery might suggest VAE, when more sensitive monitors are not available. We describe an unusual cause for sudden reduction in ETCO2 during neurosurgery and discuss the mechanism for such presentation. PMID:23996497

  14. REACTION OF ACTIVATED CARBON WITH AQUEOUS CHLORINE AND CHLORINE DIOXIDE

    EPA Science Inventory

    The objective of this research was to determine whether aqueous chlorine and chlorine dioxide react with activated carbon, or with compounds adsorbed on activated carbon, to produce compounds that would not form in the absence of activated carbon. The experimental conditions were...

  15. 46 CFR 167.45-45 - Carbon dioxide fire-extinguishing system requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide fire-extinguishing system requirements... Carbon dioxide fire-extinguishing system requirements. (a) When a carbon dioxide (CO2) smothering system is fitted in the boiler room, the quantity of carbon dioxide carried shall be sufficient to give...

  16. 46 CFR 167.45-45 - Carbon dioxide fire extinguishing system requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Carbon dioxide fire extinguishing system requirements... Carbon dioxide fire extinguishing system requirements. (a) When a carbon dioxide (CO2) smothering system is fitted in the boiler room, the quantity of carbon dioxide carried shall be sufficient to give...

  17. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than...

  18. 46 CFR 35.40-8 - Carbon dioxide warning signs-T/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Carbon dioxide warning signs-T/ALL. 35.40-8 Section 35... Marking Requirements-TB/ALL § 35.40-8 Carbon dioxide warning signs—T/ALL. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into which...

  19. 46 CFR 35.40-8 - Carbon dioxide warning signs-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Carbon dioxide warning signs-T/ALL. 35.40-8 Section 35... Marking Requirements-TB/ALL § 35.40-8 Carbon dioxide warning signs—T/ALL. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into which...

  20. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than...

  1. 46 CFR 35.40-7 - Carbon dioxide alarm-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Carbon dioxide alarm-T/ALL. 35.40-7 Section 35.40-7... Requirements-TB/ALL. § 35.40-7 Carbon dioxide alarm—T/ALL. Adjacent to all carbon dioxide fire extinguishing... AT ONCE. CARBON DIOXIDE BEING RELEASED.”...

  2. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than...

  3. 46 CFR 35.40-7 - Carbon dioxide alarm-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Carbon dioxide alarm-T/ALL. 35.40-7 Section 35.40-7... Requirements-TB/ALL. § 35.40-7 Carbon dioxide alarm—T/ALL. Adjacent to all carbon dioxide fire extinguishing... AT ONCE. CARBON DIOXIDE BEING RELEASED.”...

  4. 46 CFR 167.45-45 - Carbon dioxide fire-extinguishing system requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide fire-extinguishing system requirements... Carbon dioxide fire-extinguishing system requirements. (a) When a carbon dioxide (CO2) smothering system is fitted in the boiler room, the quantity of carbon dioxide carried shall be sufficient to give...

  5. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than...

  6. 46 CFR 35.40-8 - Carbon dioxide warning signs-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Carbon dioxide warning signs-T/ALL. 35.40-8 Section 35... Marking Requirements-TB/ALL § 35.40-8 Carbon dioxide warning signs—T/ALL. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into which...

  7. 46 CFR 167.45-45 - Carbon dioxide fire extinguishing system requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide fire extinguishing system requirements... Carbon dioxide fire extinguishing system requirements. (a) When a carbon dioxide (CO2) smothering system is fitted in the boiler room, the quantity of carbon dioxide carried shall be sufficient to give...

  8. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than...

  9. 46 CFR 167.45-45 - Carbon dioxide fire extinguishing system requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide fire extinguishing system requirements... Carbon dioxide fire extinguishing system requirements. (a) When a carbon dioxide (CO2) smothering system is fitted in the boiler room, the quantity of carbon dioxide carried shall be sufficient to give...

  10. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with...

  11. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with...

  12. 21 CFR 179.43 - Carbon dioxide laser for etching food.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Carbon dioxide laser for etching food. 179.43... § 179.43 Carbon dioxide laser for etching food. Carbon dioxide laser light may be safely used for... consists of a carbon dioxide laser designed to emit pulsed infrared radiation with a wavelength of...

  13. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with...

  14. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with...

  15. Partitioning Carbon Dioxide and Water Vapor Fluxes Using Correlation Analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Partitioning of eddy covariance flux measurements is routinely done to quantify the contributions of separate processes to the overall fluxes. Measurements of carbon dioxide fluxes represent the difference between gross ecosystem photosynthesis and total respiration, while measurements of water vapo...

  16. The oxygen and carbon dioxide balance in the earth's atmosphere

    NASA Technical Reports Server (NTRS)

    Johnson, F. S.

    1975-01-01

    The oxygen-carbon dioxide cycle is described in detail, and steps which are sensitive to perturbation or instability are identified. About half of the carbon dioxide consumption each year in photosynthesis occurs in the oceans. Phytoplankton, which are the primary producers, have been shown to assimilate insecticides and herbicides. The impact of such materials on phytoplankton photosynthesis, both direct and as the indirect result of detrimental effects higher up in the food chain, cannot be assessed. Net oxygen production is very small in comparison with the total production and occurs almost exclusively in a few ocean areas with anoxic bottom conditions and in peat-forming marshes which are sensitive to anthropogenic disturbances. The carbon dioxide content of the atmosphere is increasing at a relatively rapid rate as the result of fossil fuel combustion. Increases in photosynthesis as the result of the hothouse effect may in turn reduce the carbon dioxide content of the atmosphere, leading to global cooling.

  17. INTERIOR VIEW OF COLUMN TOPS. CARBON DIOXIDE BUBBLED THROUGH AMMONIONATED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF COLUMN TOPS. CARBON DIOXIDE BUBBLED THROUGH AMMONIONATED SALT BRINE TO MAKE BICARBONATE OF SODA. - Solvay Process Company, SA Wetside Building, Between Willis & Milton Avenue, Solvay, Onondaga County, NY

  18. Study of the interactions of molten sodium nitrate-potassium nitrate 50 mol % mixture with water vapor and carbon dioxide in air. Final report, June 2, 1980-June 30, 1981

    SciTech Connect

    White, S.H.; Twardoch, U.M.

    1981-09-01

    The interactions of aerial components such as water, carbon dioxide, and oxygen with the binary 50 mol % mixture of sodium nitrate and potassium nitrate have been studied in the temperature range 300 to 600/sup 0/C using electrochemical methods. In addition, the behavior of nitrite ions in this melt was investigated electrochemically. By judicious choice of techniques, in situ electroanalysis was possible and the necessary relevant data to accomplish this is presented, as well as insight into the corresponding electrochemical mechanisms associated with the electroactive species. The influence of each atmospheric component was examined separately. At temperatures above 300/sup 0/C, nitrite ions are found to accumulate due to thermal decomposition of the nitrate. Water is highly soluble in the salt mixture, but no hydrolytic reactions were observed. Two methods of in situ analysis for water are described. Pure carbon dioxide is found to attack the melt at all temperatures above 250/sup 0/C producing carbonate. (LEW)

  19. Carbon Dioxide Chemistry on Titan's Surface

    NASA Astrophysics Data System (ADS)

    Hodyss, R. P.; Cable, M. L.; Malaska, M. J.; Vu, T. H.

    2015-12-01

    The surfaces of the moons of the outer Solar System are usually considered too cold (30-100 K) for significant chemistry to occur without the input of energy from exogenic sources (such as charged particles or VUV irradiation). In particular, Titan's thick atmosphere prevents significant amounts of high energy radiation from reaching the surface, limiting opportunities for surface chemical reactivity. Recently, we have identified carbamation, the reaction of carbon dioxide with primary amines to form carbamic acids, as a reaction that could occur thermally on Titan's surface. Amines should be present on Titan's surface, formed by photochemical reactions of N2 and CH4 in the upper atmosphere, and amine-containing molecules have been detected as a component of laboratory tholins made in terrestrial laboratories. There is some spectral evidence that CO2 is present on the surface, and CO2 has been definitively identified in the atmosphere. We use a combination of micro-Raman spectroscopy and UHV FTIR spectroscopy to examine the reaction products and kinetics of the carbamation reaction for a variety of primary amines. The reaction occurs readily at Titan surface temperatures (94 K), and leads to both carbamic acids and ammonium carbamate salts. Our kinetic data can be used to estimate the lifetime of CO2 on Titan's surface, and thus constrain the age of possible CO2-bearing cryovolcanic deposits.

  20. Laser surgery: using the carbon dioxide laser.

    PubMed Central

    Wright, V. C.

    1982-01-01

    In 1917 Einstein theorized tha through an atomic process a unique kind of electromagnetic radiation could be produced by stimulated emission. When such radiation is in the optical or infrared spectrum it is termed laser (light amplification by stimulated emission of radiation) light. A laser, a high-intensity light source, emits a nearly parallel electromagnetic beam of energy at a given wavelength that can be captured by a lens and concentrated in the focal spot. The wavelength determines how the laser will be used. The carbon dioxide laser is now successfully employed for some surgical procedures in gynecology, otorhinolaryngology, neurosurgery, and plastic and general surgery. The CO2 laser beam is directed through the viewing system of an operating microscope or through a hand-held laser component. Its basic action in tissue is thermal vaporization; it causes minimal damage to adjacent tissues. Surgeons require special training in the basic methods and techniques of laser surgery, as well as in the safety standards that must be observed. Images FIG. 5 PMID:7074503

  1. Synthetic fuels, carbon dioxide and climate

    NASA Astrophysics Data System (ADS)

    Sapre, Alex R.; Hummel, John R.; Reck, Ruth A.

    1982-05-01

    The observed increase in atmospheric carbon dioxide (CO2) has been attributed to the use of fossil fuels. There is concern that the generation and use of synthetic fuels derived from oil shale and coal will accelerate the increase of CO2. Depending on the source, 39 or 72 percent more CO2 would be produced per unit of energy if synthetic fuels were used instead of petroleum. The use of synthetic fuels derivved from biomass would make no net addition to atmospheric CO2 provided no fossil fuels are used in biomass production and/or conversion. Assuming that synthetic liquid fuels would gradually replace petroleum and that they would supply all of the worldwide liquid fuel demand by the year 2060, we calculated that the atmospheric CO2 concentration would increase from the current 335 parts per million on a volume basis (ppmv) to 778 ppmv in 2060. However, even if the liquid fuel demand were met by petroleum alone, the CO2 level would be 715 ppmv in that year. Furthermore, we estimated that as a result of these increases in the CO2 level, the globally averaged earth's surface temperature in the year 2060 will have risen by 2.6 K with the use of synthetic liquids and 2.2 K without their use.

  2. Carbon dioxide balneotherapy and cardiovascular disease

    NASA Astrophysics Data System (ADS)

    Pagourelias, Efstathios D.; Zorou, Paraskevi G.; Tsaligopoulos, Miltiadis; Athyros, Vasilis G.; Karagiannis, Asterios; Efthimiadis, Georgios K.

    2011-09-01

    Carbon dioxide (CO2) balneotherapy is a kind of remedy with a wide spectrum of applications which have been used since the Middle Ages. However, its potential use as an adjuvant therapeutic option in patients with cardiovascular disease is not yet fully clarified. We performed a thorough review of MEDLINE Database, EMBASE, ISI WEB of Knowledge, COCHRANE database and sites funded by balneotherapy centers across Europe in order to recognize relevant studies and aggregate evidence supporting the use of CO2 baths in various cardiovascular diseases. The three main effects of CO2 hydrotherapy during whole body or partial immersion, including decline in core temperature, an increase in cutaneous blood flow, and an elevation of the score on thermal sensation, are analyzed on a pathophysiology basis. Additionally, the indications and contra-indications of the method are presented in an evidence-based way, while the need for new methodologically sufficient studies examining the use of CO2 baths in other cardiovascular substrates is discussed.

  3. Miniaturized Amperometric Solid Electrolyte Carbon Dioxide Sensors

    NASA Technical Reports Server (NTRS)

    Hunter, G. W.; Xu, J. C.; Liu, C. C.; Hammond, J. W.; Ward, B.; Lukco, D.; Lampard, P.; Artale, M.; Androjna, D.

    2006-01-01

    A miniaturized electrochemical carbon dioxide (CO2) sensor using Na3Z r2Si2PO12 (NASICON) as a solid electrolyte has been fabricated and de monstrated. Microfabrication techniques were used for sensor fabricat ion to yield a sensing area around 1.0 mm x 1.1 mm. The NASICON solid electrolyte and the Na2CO3/BaCO3 (1:1.7 molar ratio) auxiliary elect rolyte were deposited by sputtering in between and on top of the inte rdigitated finger-shaped platinum electrodes. This structure maximize s the length of the three-phase boundary (electrode, solid electrolyt e, and auxiliary electrolyte), which is critical for gas sensing. The robust CO2 sensor operated up to 600 C in an amperometric mode and a ttempts were made to optimize sensor operating parameters. Concentrat ions of CO2 between 0.02% and 4% were detected and the overall sensor performance was evaluated. Linear response of sensor current output to ln[CO2 concentration] ranging from 0.02% to 1% was achieved.

  4. System-Level Analysis Modeling of Impacts of Operation Schemes of Geologic Carbon Dioxide Storage on Deep Groundwater and Carbon Dioxide Leakage Risk

    NASA Astrophysics Data System (ADS)

    Park, S.; Lee, S.; Park, J.; Kim, J.; Kihm, J.

    2013-12-01

    The objectives of this study are to predict quantitatively groundwater and carbon dioxide flow in deep saline sandstone aquifers under various carbon dioxide injection schemes (injection rate, injection period) and to analyze integratively impacts of such carbon dioxide injection schemes on deep groundwater (brine) and carbon dioxide leakage risk through abandoned wells or faults. In order to achieve the first objective, a series of process-level prediction modeling of groundwater and carbon dioxide flow in a deep saline sandstone aquifer under several carbon dioxide injection schemes was performed using a multiphase thermo-hydrological numerical model TOUGH2 (Pruess et al., 1999). The prediction modeling results show that the extent of carbon dioxide plume is significantly affected by such carbon dioxide injection schemes. In order to achieve the second objective, a series of system-level analysis modeling of deep groundwater and carbon dioxide leakage risk through an abandoned well or a fault under several carbon dioxide injection schemes was then performed using a brine and carbon dioxide leakage risk analysis model CO2-LEAK (Kim, 2012). The analysis modeling results show that the rates and amounts of deep groundwater and carbon dioxide leakage through an abandoned well or a fault increase as the carbon dioxide injection rate increases. However, the rates and amounts of deep groundwater and carbon dioxide leakage through an abandoned well or a fault decrease as the carbon dioxide injection period increases. These system-level analysis modeling results for deep groundwater and carbon dioxide leakage risk can be utilized as baseline data for establishing guidelines to mitigate anticipated environmental adverse effects on shallower groundwater systems (aquifers) when deep groundwater and carbon dioxide leakage occur. This work was supported by the Geo-Advanced Innovative Action (GAIA) Program funded by the Korea Environmental Industry and Technology Institute

  5. Slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures

    DOEpatents

    Aines, Roger D.; Bourcier, William L.; Viani, Brian

    2013-01-29

    A slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures includes the steps of dissolving the gas mixture and carbon dioxide in water providing a gas, carbon dioxide, water mixture; adding a porous solid media to the gas, carbon dioxide, water mixture forming a slurry of gas, carbon dioxide, water, and porous solid media; heating the slurry of gas, carbon dioxide, water, and porous solid media producing steam; and cooling the steam to produce purified water and carbon dioxide.

  6. Carbon dioxide in the ocean surface: The homogeneous buffer factor

    USGS Publications Warehouse

    Sundquist, E.T.; Plummer, L.N.; Wigley, T.M.L.

    1979-01-01

    The amount of carbon dioxide that can be dissolved in surface seawater depends at least partially on the homogeneous buffer factor, which is a mathematical function of the chemical equilibrium conditions among the various dissolved inorganic species. Because these equilibria are well known, the homogeneous buffer factor is well known. Natural spatial variations depend very systematically on sea surface temperatures, and do not contribute significantly to uncertainties in the present or future carbon dioxide budget. Copyright ?? 1979 AAAS.

  7. Mycorrhizal mediation of soil organic carbon decomposition under elevated atmospheric carbon dioxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Significant effort in global change research has recently been directed towards assessing the potential of soil as a carbon sink under future atmospheric carbon dioxide scenarios. Attention has focused on the impact of elevated carbon dioxide on plant interactions with mycorrhizae, a symbiotic soil...

  8. International Space Station Carbon Dioxide Removal Assembly (ISS CDRA) Concepts and Advancements

    NASA Technical Reports Server (NTRS)

    ElSherif, Dina; Knox, James C.

    2005-01-01

    An important aspect of air revitalization for life support in spacecraft is the removal of carbon dioxide from cabin air. Several types of carbon dioxide removal systems are in use in spacecraft life support. These systems rely on various removal techniques that employ different architectures and media for scrubbing CO2, such as permeable membranes, liquid amine, adsorbents, and absorbents. Sorbent systems have been used since the first manned missions. The current state of key technology is the existing International Space Station (ISS) Carbon Dioxide Removal Assembly (CDRA), a system that selectively removes carbon dioxide from the cabin atmosphere. The CDRA system was launched aboard UF-2 in February 2001 and resides in the U.S. Destiny Laboratory module. During the past four years, the CDRA system has operated with varying degrees of success. There have been several approaches to troubleshooting the CDRA system aimed at developing work-around solutions that would minimize the impact on astronaut time required to implement interim solutions. The paper discusses some of the short-term fixes applied to promote hardware life and restore functionality, as well as long-term plans and solutions for improving operability and reliability. The CDRA is a critical piece of life support equipment in the air revitalization system of the ISS, and is demonstrated technology that may ultimately prove well-suited for use in lunar or Mars base, and Mars transit life support applications.

  9. Beneficial Use of Carbon Dioxide in Precast Concrete Production

    SciTech Connect

    Shao, Yixin

    2014-06-26

    The feasibility of using carbon dioxide as feedstock in precast concrete production is studied. Carbon dioxide reacts with calcium compounds in concrete, producing solid calcium carbonates in binding matrix. Two typical precast products are examined for their capacity to store carbon dioxide during the production. They are concrete blocks and fiber-cement panels. The two products are currently mass produced and cured by steam. Carbon dioxide can be used to replace steam in curing process to accelerate early strength, improve the long-term durability and reduce energy and emission. For a reaction within a 24-hour process window, the theoretical maximum possible carbon uptake in concrete is found to be 29% based on cement mass in the product. To reach the maximum uptake, a special process is developed to promote the reaction efficiency to 60-80% in 4-hour carbon dioxide curing and improve the resistance to freeze-thaw cycling and sulfate ion attack. The process is also optimized to meet the project target of $10/tCO2 in carbon utilization. By the use of self-concentrating absorption technology, high purity CO2 can be produced at a price below $40/t. With low cost CO2 capture and utilization technologies, it is feasible to establish a network for carbon capture and utilization at the vicinity of carbon sources. If all block produces and panel producers in United States could adopt carbon dioxide process in their production in place of steam, carbon utilization in these two markets alone could consume more than 2 Mt CO2/year. This capture and utilization process can be extended to more precast products and will continue for years to come.

  10. Simulations of Carbon Dioxide Cloud Formation at the Martian Poles

    NASA Astrophysics Data System (ADS)

    Colaprete, A.; Toon, O. B.

    1999-09-01

    The Mars Orbiter Laser Altimeter (MOLA) experiment flying onboard the Mars Global Surveyor has observed echoes from cloud tops above the north polar cap. Due to the location and time of year that these clouds are forming, it has been assumed that these clouds consist primarily of carbon dioxide ice particles. The structure of these echoes suggests that a number of these clouds may be the product of buoyancy or gravity waves (Zuber et al., 1998). While the presence of carbon dioxide clouds in the Martian atmosphere is generally accepted, how and where they form is still not understood and little is known about the physics of carbon dioxide particle formation. Recently, Glandorf et al. (personal communication) measured the critical saturation ratio required for carbon dioxide to nucleate onto ice. From this measurement, using nucleation theory, the contact parameter between ice and carbon dioxide under Martian conditions was determined. Using the nucleation rates measured by Glandorf et al. we have developed a 2D time dependent microphyical simulation of carbon dioxide clouds forming in the Mars polar regions. In this simulation we explore the mechanism of cloud initiation by orographic waves and compare our results to MOLA observations.

  11. Can fast-growing plantation trees escape biochemical down-regulation of photosynthesis when grown throughout their complete production cycle in the open air under elevated carbon dioxide?

    PubMed

    Davey, P A; Olcer, H; Zakhleniuk, O; Bernacchi, C J; Calfapietra, C; Long, S P; Raines, C A

    2006-07-01

    Poplar trees sustain close to the predicted increase in leaf photosynthesis when grown under long-term elevated CO2 concentration ([CO2]). To investigate the mechanisms underlying this response, carbohydrate accumulation and protein expression were determined over four seasons of growth. No increase in the levels of soluble carbohydrates was observed in the young expanding or mature sun leaves of the three poplar genotypes during this period. However, substantial increases in starch levels were observed in the mature leaves of all three poplar genotypes grown in elevated [CO2]. Despite the very high starch levels, no changes in the expression of photosynthetic Calvin cycle proteins, or in the starch biosynthetic enzyme ADP-glucose pyrophosphorylase (AGPase), were observed. This suggested that no long-term photosynthetic acclimation to CO2 occurred in these plants. Our data indicate that poplar trees are able to 'escape' from long-term, acclimatory down-regulation of photosynthesis through a high capacity for starch synthesis and carbon export. These findings show that these poplar genotypes are well suited to the elevated [CO2] conditions forecast for the middle of this century and may be particularly suited for planting for the long-term carbon sequestration into wood. PMID:17080946

  12. Carbon dioxide sequestration by direct aqueous mineral carbonation

    SciTech Connect

    O'Connor, William K.; Dahlin, David C.; Nilsen, David N.; Walters, Richard P.; Turner, Paul C.

    2000-01-01

    Carbon dioxide sequestration by an ex-situ, direct aqueous mineral carbonation process has been investigated over the past two years. This process was conceived to minimize the steps in the conversion of gaseous CO2 to a stable solid. This meant combining two separate reactions, mineral dissolution and carbonate precipitation, into a single unit operation. It was recognized that the conditions favorable for one of these reactions could be detrimental to the other. However, the benefits for a combined aqueous process, in process efficiency and ultimately economics, justified the investigation. The process utilizes a slurry of water, dissolved CO2, and a magnesium silicate mineral, such as olivine [forsterite end member (Mg2SiO4)], or serpentine [Mg3Si2O5(OH)4]. These minerals were selected as the reactants of choice for two reasons: (1) significant abundance in nature; and (2) high molar ratio of the alkaline earth oxides (CaO, MgO) within the minerals. Because it is the alkaline earth oxide that combines with CO2 to form the solid carbonate, those minerals with the highest ratio of these oxides are most favored. Optimum results have been achieved using heat pretreated serpentine feed material, sodium bicarbonate and sodium chloride additions to the solution, and high partial pressure of CO2 (PCO2). Specific conditions include: 155?C; PCO2=185 atm; 15% solids. Under these conditions, 78% conversion of the silicate to the carbonate was achieved in 30 minutes. Future studies are intended to investigate various mineral pretreatment options, the carbonation solution characteristics, alternative reactants, scale-up to a continuous process, geochemical modeling, and process economics.

  13. Carbon Dioxide Reduction Technology Trade Study

    NASA Technical Reports Server (NTRS)

    Jeng, Frank F.; Anderson, Molly S.; Abney, Morgan B.

    2011-01-01

    For long-term human missions, a closed-loop atmosphere revitalization system (ARS) is essential to minimize consumables. A carbon dioxide (CO2) reduction technology is used to reclaim oxygen (O2) from metabolic CO2 and is vital to reduce the delivery mass of metabolic O2. A key step in closing the loop for ARS will include a proper CO2 reduction subsystem that is reliable and with low equivalent system mass (ESM). Sabatier and Bosch CO2 reduction are two traditional CO2 reduction subsystems (CRS). Although a Sabatier CRS has been delivered to International Space Station (ISS) and is an important step toward closing the ISS ARS loop, it recovers only 50% of the available O2 in CO2. A Bosch CRS is able to reclaim all O2 in CO2. However, due to continuous carbon deposition on the catalyst surface, the penalties of replacing spent catalysts and reactors and crew time in a Bosch CRS are significant. Recently, technologies have been developed for recovering hydrogen (H2) from Sabatier-product methane (CH4). These include methane pyrolysis using a microwave plasma, catalytic thermal pyrolysis of CH4 and thermal pyrolysis of CH4. Further, development in Sabatier reactor designs based on microchannel and microlith technology could open up opportunities in reducing system mass and enhancing system control. Improvements in Bosch CRS conversion have also been reported. In addition, co-electrolysis of steam and CO2 is a new technology that integrates oxygen generation and CO2 reduction functions in a single system. A co-electrolysis unit followed by either a Sabatier or a carbon formation reactor based on Bosch chemistry could improve the overall competitiveness of an integrated O2 generation and CO2 reduction subsystem. This study evaluates all these CO2 reduction technologies, conducts water mass balances for required external supply of water for 1-, 5- and 10-yr missions, evaluates mass, volume, power, cooling and resupply requirements of various technologies. A system

  14. Terpolymerization of ethylene, sulfur dioxide and carbon monoxide

    DOEpatents

    Johnson, Richard; Steinberg, Meyer

    1981-01-01

    This invention relates to a high molecular weight terpolymer of ethylene, sulfur dioxide and carbon monoxide stable to 280.degree. C. and containing as little as 36 mol % ethylene and about 41-51 mol % sulfur dioxide; and to the method of producing said terpolymer by irradiation of a liquid and gaseous mixture of ethylene, sulfur dioxide and carbon monoxide by means of Co-60 gamma rays or an electron beam, at a temperature of about 10.degree.-50.degree. C., and at a pressure of about 140 to 680 atmospheres, to initiate polymerization.

  15. Terpolymerization of ethylene, sulfur dioxide and carbon monoxide

    DOEpatents

    Johnson, R.; Steinberg, M.

    This invention relates to high molecular weight terpolymer of ethylene, sulfur dioxide and carbon monoxide stable to 280/sup 0/C and containing as little as 36 mo1% ethylene and about 41 to 51 mo1% sulfur dioxide, and to the method of producing said terpolymer by irradiation of a liquid and gaseous mixture of ethylene, sulfur dioxide and carbon monoxide by means of Co-60 gamma rays or an electron beam, at a temperature of about 10 to 50/sup 0/C, and at a pressure of about 140 to 680 atmospheres, to initiate polymerization.

  16. Carbon Dioxide-Water Emulsions for Enhanced Oil Recovery and Permanent Sequestration of Carbon Dioxide

    SciTech Connect

    Ryan, David; Golomb, Dan; Shi, Guang; Shih, Cherry; Lewczuk, Rob; Miksch, Joshua; Manmode, Rahul; Mulagapati, Srihariraju; Malepati, Chetankurmar

    2011-09-30

    This project involves the use of an innovative new invention Particle Stabilized Emulsions (PSEs) of Carbon Dioxide-in-Water and Water-in-Carbon Dioxide for Enhanced Oil Recovery (EOR) and Permanent Sequestration of Carbon Dioxide. The EOR emulsion would be injected into a semi-depleted oil reservoir such as Dover 33 in Otsego County, Michigan. It is expected that the emulsion would dislocate the stranded heavy crude oil from the rock granule surfaces, reduce its viscosity, and increase its mobility. The advancing emulsion front should provide viscosity control which drives the reduced-viscosity oil toward the production wells. The make-up of the emulsion would be subsequently changed so it interacts with the surrounding rock minerals in order to enhance mineralization, thereby providing permanent sequestration of the injected CO{sub 2}. In Phase 1 of the project, the following tasks were accomplished: 1. Perform laboratory scale (mL/min) refinements on existing procedures for producing liquid carbon dioxide-in-water (C/W) and water-in-liquid carbon dioxide (W/C) emulsion stabilized by hydrophilic and hydrophobic fine particles, respectively, using a Kenics-type static mixer. 2. Design and cost evaluate scaled up (gal/min) C/W and W/C emulsification systems to be deployed in Phase 2 at the Otsego County semi-depleted oil field. 3. Design the modifications necessary to the present CO{sub 2} flooding system at Otsego County for emulsion injection. 4. Design monitoring and verification systems to be deployed in Phase 2 for measuring potential leakage of CO{sub 2} after emulsion injection. 5. Design production protocol to assess enhanced oil recovery with emulsion injection compared to present recovery with neat CO{sub 2} flooding. 6. Obtain Federal and State permits for emulsion injection. Initial research focused on creating particle stabilized emulsions with the smallest possible globule size so that the emulsion can penetrate even low-permeability crude

  17. The role of renewable bioenergy in carbon dioxide sequestration

    SciTech Connect

    Kinoshita, C.M.

    1993-12-31

    The use of renewable resources represents a sound approach to producing clean energy and reducing the dependence on diminishing reserves of fossil fuels. Unfortunately, the widespread interest in renewable energy in the 1970s, spurred by escalating fossil fuel prices, subsided with the collapse of energy prices in the mid 1980s. Today, it is largely to reverse alarming environmental trends, particularly the buildup of atmospheric carbon dioxide, rather than to reduce the cost of energy, that renewable energy resources are being pursued. This discussion focuses on a specific class of renewable energy resources - biomass. Unlike most other classes of renewable energy touted for controlling atmospheric carbon dioxide concentrations, e.g., hydro, direct solar, wind, geothermal, and ocean thermal, which produce usable forms of energy while generating little or no carbon dioxide emissions, bioenergy almost always involves combustion and therefore generates carbon dioxide; however, if used on a sustained basis, bio-energy would not contribute to the build-up of atmospheric carbon dioxide because the amount released in combustion would be balanced by that taken up via photosynthesis. It is in that context, i.e., sustained production of biomass as a modern energy carrier, rather than reforestation for carbon sequestration, that biomass is being discussed here, since biomass can play a much greater role in controlling global warming by displacing fossil fuels than by being used strictly for carbon sequestration (partly because energy crop production can reduce fossil carbon dioxide emissions indefinitely, whereas under the reforestation strategy, carbon dioxide abatement ceases at forest maturity).

  18. Renewable and metal-free carbon nanofibre catalysts for carbon dioxide reduction

    NASA Astrophysics Data System (ADS)

    Kumar, Bijandra; Asadi, Mohammad; Pisasale, Davide; Sinha-Ray, Suman; Rosen, Brian A.; Haasch, Richard; Abiade, Jeremiah; Yarin, Alexander L.; Salehi-Khojin, Amin

    2013-12-01

    The development of an efficient catalyst system for the electrochemical reduction of carbon dioxide into energy-rich products is a major research topic. Here we report the catalytic ability of polyacrylonitrile-based heteroatomic carbon nanofibres for carbon dioxide reduction into carbon monoxide, via a metal-free, renewable and cost-effective route. The carbon nanofibre catalyst exhibits negligible overpotential (0.17 V) for carbon dioxide reduction and more than an order of magnitude higher current density compared with the silver catalyst under similar experimental conditions. The carbon dioxide reduction ability of carbon nanofibres is attributed to the reduced carbons rather than to electronegative nitrogen atoms. The superior performance is credited to the nanofibrillar structure and high binding energy of key intermediates to the carbon nanofibre surfaces. The finding may lead to a new generation of metal-free and non-precious catalysts with much greater efficiency than the existing noble metal catalysts.

  19. Effects of large-scale Amazon forest degradation on climate and air quality through fluxes of carbon dioxide, water, energy, mineral dust and isoprene.

    PubMed

    Betts, Richard; Sanderson, Michael; Woodward, Stephanie

    2008-05-27

    Loss of large areas of Amazonian forest, through either direct human impact or climate change, could exert a number of influences on the regional and global climates. In the Met Office Hadley Centre coupled climate-carbon cycle model, a severe drying of this region initiates forest loss that exerts a number of feedbacks on global and regional climates, which magnify the drying and the forest degradation. This paper provides an overview of the multiple feedback process in the Hadley Centre model and discusses the implications of the results for the case of direct human-induced deforestation. It also examines additional potential effects of forest loss through changes in the emissions of mineral dust and biogenic volatile organic compounds. The implications of ecosystem-climate feedbacks for climate change mitigation and adaptation policies are also discussed. PMID:18267906

  20. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Brian S. Turk; Jeffrey W. Portzer; Raghubir P. Gupta; William J. McMichael; Thomas Nelson

    2004-07-01

    This report describes research conducted between April 1, 2004 and June 30, 2004 on the preparation and use of dry regenerable sorbents for removal of carbon dioxide from flue gas. Support materials and supported sorbents were prepared by spray drying. Sorbents consisting of 20 to 50% sodium carbonate on a ceramic support were prepared by spray drying in batches of approximately 300 grams. The supported sorbents exhibited greater carbon dioxide capture rates than unsupported calcined sodium bicarbonate in laboratory tests. Preliminary process design and cost estimation for a retrofit application suggested that costs of a dry regenerable sodium carbonate-based process could be lower than those of a monoethanolamine absorption system. In both cases, the greatest part of the process costs come from power plant output reductions due to parasitic consumption of steam for recovery of carbon dioxide from the capture medium.